Adding upstream version 5.10.209.upstream/5.10.209upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

147 files changed, 121067 insertions, 0 deletions

diff --git a/fs/nfs/Kconfig b/fs/nfs/Kconfig
new file mode 100644
index 000000000..14a72224b
--- /dev/null
+++ b/fs/nfs/Kconfig
@@ -0,0 +1,216 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config NFS_FS
+	tristate "NFS client support"
+	depends on INET && FILE_LOCKING && MULTIUSER
+	select LOCKD
+	select SUNRPC
+	select NFS_ACL_SUPPORT if NFS_V3_ACL
+	help
+	  Choose Y here if you want to access files residing on other
+	  computers using Sun's Network File System protocol.  To compile
+	  this file system support as a module, choose M here: the module
+	  will be called nfs.
+
+	  To mount file systems exported by NFS servers, you also need to
+	  install the user space mount.nfs command which can be found in
+	  the Linux nfs-utils package, available from http://linux-nfs.org/.
+	  Information about using the mount command is available in the
+	  mount(8) man page.  More detail about the Linux NFS client
+	  implementation is available via the nfs(5) man page.
+
+	  Below you can choose which versions of the NFS protocol are
+	  available in the kernel to mount NFS servers.  Support for NFS
+	  version 2 (RFC 1094) is always available when NFS_FS is selected.
+
+	  To configure a system which mounts its root file system via NFS
+	  at boot time, say Y here, select "Kernel level IP
+	  autoconfiguration" in the NETWORK menu, and select "Root file
+	  system on NFS" below.  You cannot compile this file system as a
+	  module in this case.
+
+	  If unsure, say N.
+
+config NFS_V2
+	tristate "NFS client support for NFS version 2"
+	depends on NFS_FS
+	default y
+	help
+	  This option enables support for version 2 of the NFS protocol
+	  (RFC 1094) in the kernel's NFS client.
+
+	  If unsure, say Y.
+
+config NFS_V3
+	tristate "NFS client support for NFS version 3"
+	depends on NFS_FS
+	default y
+	help
+	  This option enables support for version 3 of the NFS protocol
+	  (RFC 1813) in the kernel's NFS client.
+
+	  If unsure, say Y.
+
+config NFS_V3_ACL
+	bool "NFS client support for the NFSv3 ACL protocol extension"
+	depends on NFS_V3
+	help
+	  Some NFS servers support an auxiliary NFSv3 ACL protocol that
+	  Sun added to Solaris but never became an official part of the
+	  NFS version 3 protocol.  This protocol extension allows
+	  applications on NFS clients to manipulate POSIX Access Control
+	  Lists on files residing on NFS servers.  NFS servers enforce
+	  ACLs on local files whether this protocol is available or not.
+
+	  Choose Y here if your NFS server supports the Solaris NFSv3 ACL
+	  protocol extension and you want your NFS client to allow
+	  applications to access and modify ACLs on files on the server.
+
+	  Most NFS servers don't support the Solaris NFSv3 ACL protocol
+	  extension.  You can choose N here or specify the "noacl" mount
+	  option to prevent your NFS client from trying to use the NFSv3
+	  ACL protocol.
+
+	  If unsure, say N.
+
+config NFS_V4
+	tristate "NFS client support for NFS version 4"
+	depends on NFS_FS
+	select SUNRPC_GSS
+	select KEYS
+	help
+	  This option enables support for version 4 of the NFS protocol
+	  (RFC 3530) in the kernel's NFS client.
+
+	  To mount NFS servers using NFSv4, you also need to install user
+	  space programs which can be found in the Linux nfs-utils package,
+	  available from http://linux-nfs.org/.
+
+	  If unsure, say Y.
+
+config NFS_SWAP
+	bool "Provide swap over NFS support"
+	default n
+	depends on NFS_FS && SWAP
+	select SUNRPC_SWAP
+	help
+	  This option enables swapon to work on files located on NFS mounts.
+
+config NFS_V4_1
+	bool "NFS client support for NFSv4.1"
+	depends on NFS_V4
+	select SUNRPC_BACKCHANNEL
+	help
+	  This option enables support for minor version 1 of the NFSv4 protocol
+	  (RFC 5661) in the kernel's NFS client.
+
+	  If unsure, say N.
+
+config NFS_V4_2
+	bool "NFS client support for NFSv4.2"
+	depends on NFS_V4_1
+	help
+	  This option enables support for minor version 2 of the NFSv4 protocol
+	  in the kernel's NFS client.
+
+	  If unsure, say N.
+
+config PNFS_FILE_LAYOUT
+	tristate
+	depends on NFS_V4_1
+	default NFS_V4
+
+config PNFS_BLOCK
+	tristate
+	depends on NFS_V4_1 && BLK_DEV_DM
+	default NFS_V4
+
+config PNFS_FLEXFILE_LAYOUT
+	tristate
+	depends on NFS_V4_1 && NFS_V3
+	default NFS_V4
+
+config NFS_V4_1_IMPLEMENTATION_ID_DOMAIN
+	string "NFSv4.1 Implementation ID Domain"
+	depends on NFS_V4_1
+	default "kernel.org"
+	help
+	  This option defines the domain portion of the implementation ID that
+	  may be sent in the NFS exchange_id operation.  The value must be in
+	  the format of a DNS domain name and should be set to the DNS domain
+	  name of the distribution.
+	  If the NFS client is unchanged from the upstream kernel, this
+	  option should be set to the default "kernel.org".
+
+config NFS_V4_1_MIGRATION
+	bool "NFSv4.1 client support for migration"
+	depends on NFS_V4_1
+	default n
+	help
+	  This option makes the NFS client advertise to NFSv4.1 servers that
+          it can support NFSv4 migration.
+
+          The NFSv4.1 pieces of the Linux NFSv4 migration implementation are
+          still experimental.  If you are not an NFSv4 developer, say N here.
+
+config NFS_V4_SECURITY_LABEL
+	bool
+	depends on NFS_V4_2 && SECURITY
+	default y
+
+config ROOT_NFS
+	bool "Root file system on NFS"
+	depends on NFS_FS=y && IP_PNP
+	help
+	  If you want your system to mount its root file system via NFS,
+	  choose Y here.  This is common practice for managing systems
+	  without local permanent storage.  For details, read
+	  <file:Documentation/admin-guide/nfs/nfsroot.rst>.
+
+	  Most people say N here.
+
+config NFS_FSCACHE
+	bool "Provide NFS client caching support"
+	depends on NFS_FS=m && FSCACHE || NFS_FS=y && FSCACHE=y
+	help
+	  Say Y here if you want NFS data to be cached locally on disc through
+	  the general filesystem cache manager
+
+config NFS_USE_LEGACY_DNS
+	bool "Use the legacy NFS DNS resolver"
+	depends on NFS_V4
+	help
+	  The kernel now provides a method for translating a host name into an
+	  IP address.  Select Y here if you would rather use your own DNS
+	  resolver script.
+
+	  If unsure, say N
+
+config NFS_USE_KERNEL_DNS
+	bool
+	depends on NFS_V4 && !NFS_USE_LEGACY_DNS
+	select DNS_RESOLVER
+	default y
+
+config NFS_DEBUG
+	bool
+	depends on NFS_FS && SUNRPC_DEBUG
+	select CRC32
+	default y
+
+config NFS_DISABLE_UDP_SUPPORT
+       bool "NFS: Disable NFS UDP protocol support"
+       depends on NFS_FS
+       default y
+       help
+	 Choose Y here to disable the use of NFS over UDP. NFS over UDP
+	 on modern networks (1Gb+) can lead to data corruption caused by
+	 fragmentation during high loads.
+
+config NFS_V4_2_READ_PLUS
+	bool "NFS: Enable support for the NFSv4.2 READ_PLUS operation"
+	depends on NFS_V4_2
+	default n
+	help
+	 This is intended for developers only. The READ_PLUS operation has
+	 been shown to have issues under specific conditions and should not
+	 be used in production.
diff --git a/fs/nfs/Makefile b/fs/nfs/Makefile
new file mode 100644
index 000000000..22d11fdc6
--- /dev/null
+++ b/fs/nfs/Makefile
@@ -0,0 +1,37 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for the Linux nfs filesystem routines.
+#
+
+obj-$(CONFIG_NFS_FS) += nfs.o
+
+CFLAGS_nfstrace.o += -I$(src)
+nfs-y 			:= client.o dir.o file.o getroot.o inode.o super.o \
+			   io.o direct.o pagelist.o read.o symlink.o unlink.o \
+			   write.o namespace.o mount_clnt.o nfstrace.o \
+			   export.o sysfs.o fs_context.o
+nfs-$(CONFIG_ROOT_NFS)	+= nfsroot.o
+nfs-$(CONFIG_SYSCTL)	+= sysctl.o
+nfs-$(CONFIG_NFS_FSCACHE) += fscache.o fscache-index.o
+
+obj-$(CONFIG_NFS_V2) += nfsv2.o
+nfsv2-y := nfs2super.o proc.o nfs2xdr.o
+
+obj-$(CONFIG_NFS_V3) += nfsv3.o
+nfsv3-y := nfs3super.o nfs3client.o nfs3proc.o nfs3xdr.o
+nfsv3-$(CONFIG_NFS_V3_ACL) += nfs3acl.o
+
+obj-$(CONFIG_NFS_V4) += nfsv4.o
+CFLAGS_nfs4trace.o += -I$(src)
+nfsv4-y := nfs4proc.o nfs4xdr.o nfs4state.o nfs4renewd.o nfs4super.o nfs4file.o \
+	  delegation.o nfs4idmap.o callback.o callback_xdr.o callback_proc.o \
+	  nfs4namespace.o nfs4getroot.o nfs4client.o nfs4session.o \
+	  dns_resolve.o nfs4trace.o
+nfsv4-$(CONFIG_NFS_USE_LEGACY_DNS) += cache_lib.o
+nfsv4-$(CONFIG_SYSCTL)	+= nfs4sysctl.o
+nfsv4-$(CONFIG_NFS_V4_1)	+= pnfs.o pnfs_dev.o pnfs_nfs.o
+nfsv4-$(CONFIG_NFS_V4_2)	+= nfs42proc.o nfs42xattr.o
+
+obj-$(CONFIG_PNFS_FILE_LAYOUT) += filelayout/
+obj-$(CONFIG_PNFS_BLOCK) += blocklayout/
+obj-$(CONFIG_PNFS_FLEXFILE_LAYOUT) += flexfilelayout/
diff --git a/fs/nfs/blocklayout/Makefile b/fs/nfs/blocklayout/Makefile
new file mode 100644
index 000000000..7668a1bfb
--- /dev/null
+++ b/fs/nfs/blocklayout/Makefile
@@ -0,0 +1,7 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Makefile for the pNFS block layout driver kernel module
+#
+obj-$(CONFIG_PNFS_BLOCK) += blocklayoutdriver.o
+
+blocklayoutdriver-y += blocklayout.o dev.o extent_tree.o rpc_pipefs.o
diff --git a/fs/nfs/blocklayout/blocklayout.c b/fs/nfs/blocklayout/blocklayout.c
new file mode 100644
index 000000000..73000aa2d
--- /dev/null
+++ b/fs/nfs/blocklayout/blocklayout.c
@@ -0,0 +1,1055 @@
+/*
+ *  linux/fs/nfs/blocklayout/blocklayout.c
+ *
+ *  Module for the NFSv4.1 pNFS block layout driver.
+ *
+ *  Copyright (c) 2006 The Regents of the University of Michigan.
+ *  All rights reserved.
+ *
+ *  Andy Adamson <andros@citi.umich.edu>
+ *  Fred Isaman <iisaman@umich.edu>
+ *
+ * permission is granted to use, copy, create derivative works and
+ * redistribute this software and such derivative works for any purpose,
+ * so long as the name of the university of michigan is not used in
+ * any advertising or publicity pertaining to the use or distribution
+ * of this software without specific, written prior authorization.  if
+ * the above copyright notice or any other identification of the
+ * university of michigan is included in any copy of any portion of
+ * this software, then the disclaimer below must also be included.
+ *
+ * this software is provided as is, without representation from the
+ * university of michigan as to its fitness for any purpose, and without
+ * warranty by the university of michigan of any kind, either express
+ * or implied, including without limitation the implied warranties of
+ * merchantability and fitness for a particular purpose.  the regents
+ * of the university of michigan shall not be liable for any damages,
+ * including special, indirect, incidental, or consequential damages,
+ * with respect to any claim arising out or in connection with the use
+ * of the software, even if it has been or is hereafter advised of the
+ * possibility of such damages.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/mount.h>
+#include <linux/namei.h>
+#include <linux/bio.h>		/* struct bio */
+#include <linux/prefetch.h>
+#include <linux/pagevec.h>
+
+#include "../pnfs.h"
+#include "../nfs4session.h"
+#include "../internal.h"
+#include "blocklayout.h"
+
+#define NFSDBG_FACILITY	NFSDBG_PNFS_LD
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Andy Adamson <andros@citi.umich.edu>");
+MODULE_DESCRIPTION("The NFSv4.1 pNFS Block layout driver");
+
+static bool is_hole(struct pnfs_block_extent *be)
+{
+	switch (be->be_state) {
+	case PNFS_BLOCK_NONE_DATA:
+		return true;
+	case PNFS_BLOCK_INVALID_DATA:
+		return be->be_tag ? false : true;
+	default:
+		return false;
+	}
+}
+
+/* The data we are handed might be spread across several bios.  We need
+ * to track when the last one is finished.
+ */
+struct parallel_io {
+	struct kref refcnt;
+	void (*pnfs_callback) (void *data);
+	void *data;
+};
+
+static inline struct parallel_io *alloc_parallel(void *data)
+{
+	struct parallel_io *rv;
+
+	rv  = kmalloc(sizeof(*rv), GFP_NOFS);
+	if (rv) {
+		rv->data = data;
+		kref_init(&rv->refcnt);
+	}
+	return rv;
+}
+
+static inline void get_parallel(struct parallel_io *p)
+{
+	kref_get(&p->refcnt);
+}
+
+static void destroy_parallel(struct kref *kref)
+{
+	struct parallel_io *p = container_of(kref, struct parallel_io, refcnt);
+
+	dprintk("%s enter\n", __func__);
+	p->pnfs_callback(p->data);
+	kfree(p);
+}
+
+static inline void put_parallel(struct parallel_io *p)
+{
+	kref_put(&p->refcnt, destroy_parallel);
+}
+
+static struct bio *
+bl_submit_bio(struct bio *bio)
+{
+	if (bio) {
+		get_parallel(bio->bi_private);
+		dprintk("%s submitting %s bio %u@%llu\n", __func__,
+			bio_op(bio) == READ ? "read" : "write",
+			bio->bi_iter.bi_size,
+			(unsigned long long)bio->bi_iter.bi_sector);
+		submit_bio(bio);
+	}
+	return NULL;
+}
+
+static struct bio *
+bl_alloc_init_bio(int npg, struct block_device *bdev, sector_t disk_sector,
+		bio_end_io_t end_io, struct parallel_io *par)
+{
+	struct bio *bio;
+
+	npg = min(npg, BIO_MAX_PAGES);
+	bio = bio_alloc(GFP_NOIO, npg);
+	if (!bio && (current->flags & PF_MEMALLOC)) {
+		while (!bio && (npg /= 2))
+			bio = bio_alloc(GFP_NOIO, npg);
+	}
+
+	if (bio) {
+		bio->bi_iter.bi_sector = disk_sector;
+		bio_set_dev(bio, bdev);
+		bio->bi_end_io = end_io;
+		bio->bi_private = par;
+	}
+	return bio;
+}
+
+static bool offset_in_map(u64 offset, struct pnfs_block_dev_map *map)
+{
+	return offset >= map->start && offset < map->start + map->len;
+}
+
+static struct bio *
+do_add_page_to_bio(struct bio *bio, int npg, int rw, sector_t isect,
+		struct page *page, struct pnfs_block_dev_map *map,
+		struct pnfs_block_extent *be, bio_end_io_t end_io,
+		struct parallel_io *par, unsigned int offset, int *len)
+{
+	struct pnfs_block_dev *dev =
+		container_of(be->be_device, struct pnfs_block_dev, node);
+	u64 disk_addr, end;
+
+	dprintk("%s: npg %d rw %d isect %llu offset %u len %d\n", __func__,
+		npg, rw, (unsigned long long)isect, offset, *len);
+
+	/* translate to device offset */
+	isect += be->be_v_offset;
+	isect -= be->be_f_offset;
+
+	/* translate to physical disk offset */
+	disk_addr = (u64)isect << SECTOR_SHIFT;
+	if (!offset_in_map(disk_addr, map)) {
+		if (!dev->map(dev, disk_addr, map) || !offset_in_map(disk_addr, map))
+			return ERR_PTR(-EIO);
+		bio = bl_submit_bio(bio);
+	}
+	disk_addr += map->disk_offset;
+	disk_addr -= map->start;
+
+	/* limit length to what the device mapping allows */
+	end = disk_addr + *len;
+	if (end >= map->start + map->len)
+		*len = map->start + map->len - disk_addr;
+
+retry:
+	if (!bio) {
+		bio = bl_alloc_init_bio(npg, map->bdev,
+				disk_addr >> SECTOR_SHIFT, end_io, par);
+		if (!bio)
+			return ERR_PTR(-ENOMEM);
+		bio_set_op_attrs(bio, rw, 0);
+	}
+	if (bio_add_page(bio, page, *len, offset) < *len) {
+		bio = bl_submit_bio(bio);
+		goto retry;
+	}
+	return bio;
+}
+
+static void bl_mark_devices_unavailable(struct nfs_pgio_header *header, bool rw)
+{
+	struct pnfs_block_layout *bl = BLK_LSEG2EXT(header->lseg);
+	size_t bytes_left = header->args.count;
+	sector_t isect, extent_length = 0;
+	struct pnfs_block_extent be;
+
+	isect = header->args.offset >> SECTOR_SHIFT;
+	bytes_left += header->args.offset - (isect << SECTOR_SHIFT);
+
+	while (bytes_left > 0) {
+		if (!ext_tree_lookup(bl, isect, &be, rw))
+				return;
+		extent_length = be.be_length - (isect - be.be_f_offset);
+		nfs4_mark_deviceid_unavailable(be.be_device);
+		isect += extent_length;
+		if (bytes_left > extent_length << SECTOR_SHIFT)
+			bytes_left -= extent_length << SECTOR_SHIFT;
+		else
+			bytes_left = 0;
+	}
+}
+
+static void bl_end_io_read(struct bio *bio)
+{
+	struct parallel_io *par = bio->bi_private;
+
+	if (bio->bi_status) {
+		struct nfs_pgio_header *header = par->data;
+
+		if (!header->pnfs_error)
+			header->pnfs_error = -EIO;
+		pnfs_set_lo_fail(header->lseg);
+		bl_mark_devices_unavailable(header, false);
+	}
+
+	bio_put(bio);
+	put_parallel(par);
+}
+
+static void bl_read_cleanup(struct work_struct *work)
+{
+	struct rpc_task *task;
+	struct nfs_pgio_header *hdr;
+	dprintk("%s enter\n", __func__);
+	task = container_of(work, struct rpc_task, u.tk_work);
+	hdr = container_of(task, struct nfs_pgio_header, task);
+	pnfs_ld_read_done(hdr);
+}
+
+static void
+bl_end_par_io_read(void *data)
+{
+	struct nfs_pgio_header *hdr = data;
+
+	hdr->task.tk_status = hdr->pnfs_error;
+	INIT_WORK(&hdr->task.u.tk_work, bl_read_cleanup);
+	schedule_work(&hdr->task.u.tk_work);
+}
+
+static enum pnfs_try_status
+bl_read_pagelist(struct nfs_pgio_header *header)
+{
+	struct pnfs_block_layout *bl = BLK_LSEG2EXT(header->lseg);
+	struct pnfs_block_dev_map map = { .start = NFS4_MAX_UINT64 };
+	struct bio *bio = NULL;
+	struct pnfs_block_extent be;
+	sector_t isect, extent_length = 0;
+	struct parallel_io *par;
+	loff_t f_offset = header->args.offset;
+	size_t bytes_left = header->args.count;
+	unsigned int pg_offset = header->args.pgbase, pg_len;
+	struct page **pages = header->args.pages;
+	int pg_index = header->args.pgbase >> PAGE_SHIFT;
+	const bool is_dio = (header->dreq != NULL);
+	struct blk_plug plug;
+	int i;
+
+	dprintk("%s enter nr_pages %u offset %lld count %u\n", __func__,
+		header->page_array.npages, f_offset,
+		(unsigned int)header->args.count);
+
+	par = alloc_parallel(header);
+	if (!par)
+		return PNFS_NOT_ATTEMPTED;
+	par->pnfs_callback = bl_end_par_io_read;
+
+	blk_start_plug(&plug);
+
+	isect = (sector_t) (f_offset >> SECTOR_SHIFT);
+	/* Code assumes extents are page-aligned */
+	for (i = pg_index; i < header->page_array.npages; i++) {
+		if (extent_length <= 0) {
+			/* We've used up the previous extent */
+			bio = bl_submit_bio(bio);
+
+			/* Get the next one */
+			if (!ext_tree_lookup(bl, isect, &be, false)) {
+				header->pnfs_error = -EIO;
+				goto out;
+			}
+			extent_length = be.be_length - (isect - be.be_f_offset);
+		}
+
+		if (is_dio) {
+			if (pg_offset + bytes_left > PAGE_SIZE)
+				pg_len = PAGE_SIZE - pg_offset;
+			else
+				pg_len = bytes_left;
+		} else {
+			BUG_ON(pg_offset != 0);
+			pg_len = PAGE_SIZE;
+		}
+
+		if (is_hole(&be)) {
+			bio = bl_submit_bio(bio);
+			/* Fill hole w/ zeroes w/o accessing device */
+			dprintk("%s Zeroing page for hole\n", __func__);
+			zero_user_segment(pages[i], pg_offset, pg_len);
+
+			/* invalidate map */
+			map.start = NFS4_MAX_UINT64;
+		} else {
+			bio = do_add_page_to_bio(bio,
+						 header->page_array.npages - i,
+						 READ,
+						 isect, pages[i], &map, &be,
+						 bl_end_io_read, par,
+						 pg_offset, &pg_len);
+			if (IS_ERR(bio)) {
+				header->pnfs_error = PTR_ERR(bio);
+				bio = NULL;
+				goto out;
+			}
+		}
+		isect += (pg_len >> SECTOR_SHIFT);
+		extent_length -= (pg_len >> SECTOR_SHIFT);
+		f_offset += pg_len;
+		bytes_left -= pg_len;
+		pg_offset = 0;
+	}
+	if ((isect << SECTOR_SHIFT) >= header->inode->i_size) {
+		header->res.eof = 1;
+		header->res.count = header->inode->i_size - header->args.offset;
+	} else {
+		header->res.count = (isect << SECTOR_SHIFT) - header->args.offset;
+	}
+out:
+	bl_submit_bio(bio);
+	blk_finish_plug(&plug);
+	put_parallel(par);
+	return PNFS_ATTEMPTED;
+}
+
+static void bl_end_io_write(struct bio *bio)
+{
+	struct parallel_io *par = bio->bi_private;
+	struct nfs_pgio_header *header = par->data;
+
+	if (bio->bi_status) {
+		if (!header->pnfs_error)
+			header->pnfs_error = -EIO;
+		pnfs_set_lo_fail(header->lseg);
+		bl_mark_devices_unavailable(header, true);
+	}
+	bio_put(bio);
+	put_parallel(par);
+}
+
+/* Function scheduled for call during bl_end_par_io_write,
+ * it marks sectors as written and extends the commitlist.
+ */
+static void bl_write_cleanup(struct work_struct *work)
+{
+	struct rpc_task *task = container_of(work, struct rpc_task, u.tk_work);
+	struct nfs_pgio_header *hdr =
+			container_of(task, struct nfs_pgio_header, task);
+
+	dprintk("%s enter\n", __func__);
+
+	if (likely(!hdr->pnfs_error)) {
+		struct pnfs_block_layout *bl = BLK_LSEG2EXT(hdr->lseg);
+		u64 start = hdr->args.offset & (loff_t)PAGE_MASK;
+		u64 end = (hdr->args.offset + hdr->args.count +
+			PAGE_SIZE - 1) & (loff_t)PAGE_MASK;
+		u64 lwb = hdr->args.offset + hdr->args.count;
+
+		ext_tree_mark_written(bl, start >> SECTOR_SHIFT,
+					(end - start) >> SECTOR_SHIFT, lwb);
+	}
+
+	pnfs_ld_write_done(hdr);
+}
+
+/* Called when last of bios associated with a bl_write_pagelist call finishes */
+static void bl_end_par_io_write(void *data)
+{
+	struct nfs_pgio_header *hdr = data;
+
+	hdr->task.tk_status = hdr->pnfs_error;
+	hdr->verf.committed = NFS_FILE_SYNC;
+	INIT_WORK(&hdr->task.u.tk_work, bl_write_cleanup);
+	schedule_work(&hdr->task.u.tk_work);
+}
+
+static enum pnfs_try_status
+bl_write_pagelist(struct nfs_pgio_header *header, int sync)
+{
+	struct pnfs_block_layout *bl = BLK_LSEG2EXT(header->lseg);
+	struct pnfs_block_dev_map map = { .start = NFS4_MAX_UINT64 };
+	struct bio *bio = NULL;
+	struct pnfs_block_extent be;
+	sector_t isect, extent_length = 0;
+	struct parallel_io *par = NULL;
+	loff_t offset = header->args.offset;
+	size_t count = header->args.count;
+	struct page **pages = header->args.pages;
+	int pg_index = header->args.pgbase >> PAGE_SHIFT;
+	unsigned int pg_len;
+	struct blk_plug plug;
+	int i;
+
+	dprintk("%s enter, %zu@%lld\n", __func__, count, offset);
+
+	/* At this point, header->page_aray is a (sequential) list of nfs_pages.
+	 * We want to write each, and if there is an error set pnfs_error
+	 * to have it redone using nfs.
+	 */
+	par = alloc_parallel(header);
+	if (!par)
+		return PNFS_NOT_ATTEMPTED;
+	par->pnfs_callback = bl_end_par_io_write;
+
+	blk_start_plug(&plug);
+
+	/* we always write out the whole page */
+	offset = offset & (loff_t)PAGE_MASK;
+	isect = offset >> SECTOR_SHIFT;
+
+	for (i = pg_index; i < header->page_array.npages; i++) {
+		if (extent_length <= 0) {
+			/* We've used up the previous extent */
+			bio = bl_submit_bio(bio);
+			/* Get the next one */
+			if (!ext_tree_lookup(bl, isect, &be, true)) {
+				header->pnfs_error = -EINVAL;
+				goto out;
+			}
+
+			extent_length = be.be_length - (isect - be.be_f_offset);
+		}
+
+		pg_len = PAGE_SIZE;
+		bio = do_add_page_to_bio(bio, header->page_array.npages - i,
+					 WRITE, isect, pages[i], &map, &be,
+					 bl_end_io_write, par,
+					 0, &pg_len);
+		if (IS_ERR(bio)) {
+			header->pnfs_error = PTR_ERR(bio);
+			bio = NULL;
+			goto out;
+		}
+
+		offset += pg_len;
+		count -= pg_len;
+		isect += (pg_len >> SECTOR_SHIFT);
+		extent_length -= (pg_len >> SECTOR_SHIFT);
+	}
+
+	header->res.count = header->args.count;
+out:
+	bl_submit_bio(bio);
+	blk_finish_plug(&plug);
+	put_parallel(par);
+	return PNFS_ATTEMPTED;
+}
+
+static void bl_free_layout_hdr(struct pnfs_layout_hdr *lo)
+{
+	struct pnfs_block_layout *bl = BLK_LO2EXT(lo);
+	int err;
+
+	dprintk("%s enter\n", __func__);
+
+	err = ext_tree_remove(bl, true, 0, LLONG_MAX);
+	WARN_ON(err);
+
+	kfree_rcu(bl, bl_layout.plh_rcu);
+}
+
+static struct pnfs_layout_hdr *__bl_alloc_layout_hdr(struct inode *inode,
+		gfp_t gfp_flags, bool is_scsi_layout)
+{
+	struct pnfs_block_layout *bl;
+
+	dprintk("%s enter\n", __func__);
+	bl = kzalloc(sizeof(*bl), gfp_flags);
+	if (!bl)
+		return NULL;
+
+	bl->bl_ext_rw = RB_ROOT;
+	bl->bl_ext_ro = RB_ROOT;
+	spin_lock_init(&bl->bl_ext_lock);
+
+	bl->bl_scsi_layout = is_scsi_layout;
+	return &bl->bl_layout;
+}
+
+static struct pnfs_layout_hdr *bl_alloc_layout_hdr(struct inode *inode,
+						   gfp_t gfp_flags)
+{
+	return __bl_alloc_layout_hdr(inode, gfp_flags, false);
+}
+
+static struct pnfs_layout_hdr *sl_alloc_layout_hdr(struct inode *inode,
+						   gfp_t gfp_flags)
+{
+	return __bl_alloc_layout_hdr(inode, gfp_flags, true);
+}
+
+static void bl_free_lseg(struct pnfs_layout_segment *lseg)
+{
+	dprintk("%s enter\n", __func__);
+	kfree(lseg);
+}
+
+/* Tracks info needed to ensure extents in layout obey constraints of spec */
+struct layout_verification {
+	u32 mode;	/* R or RW */
+	u64 start;	/* Expected start of next non-COW extent */
+	u64 inval;	/* Start of INVAL coverage */
+	u64 cowread;	/* End of COW read coverage */
+};
+
+/* Verify the extent meets the layout requirements of the pnfs-block draft,
+ * section 2.3.1.
+ */
+static int verify_extent(struct pnfs_block_extent *be,
+			 struct layout_verification *lv)
+{
+	if (lv->mode == IOMODE_READ) {
+		if (be->be_state == PNFS_BLOCK_READWRITE_DATA ||
+		    be->be_state == PNFS_BLOCK_INVALID_DATA)
+			return -EIO;
+		if (be->be_f_offset != lv->start)
+			return -EIO;
+		lv->start += be->be_length;
+		return 0;
+	}
+	/* lv->mode == IOMODE_RW */
+	if (be->be_state == PNFS_BLOCK_READWRITE_DATA) {
+		if (be->be_f_offset != lv->start)
+			return -EIO;
+		if (lv->cowread > lv->start)
+			return -EIO;
+		lv->start += be->be_length;
+		lv->inval = lv->start;
+		return 0;
+	} else if (be->be_state == PNFS_BLOCK_INVALID_DATA) {
+		if (be->be_f_offset != lv->start)
+			return -EIO;
+		lv->start += be->be_length;
+		return 0;
+	} else if (be->be_state == PNFS_BLOCK_READ_DATA) {
+		if (be->be_f_offset > lv->start)
+			return -EIO;
+		if (be->be_f_offset < lv->inval)
+			return -EIO;
+		if (be->be_f_offset < lv->cowread)
+			return -EIO;
+		/* It looks like you might want to min this with lv->start,
+		 * but you really don't.
+		 */
+		lv->inval = lv->inval + be->be_length;
+		lv->cowread = be->be_f_offset + be->be_length;
+		return 0;
+	} else
+		return -EIO;
+}
+
+static int decode_sector_number(__be32 **rp, sector_t *sp)
+{
+	uint64_t s;
+
+	*rp = xdr_decode_hyper(*rp, &s);
+	if (s & 0x1ff) {
+		printk(KERN_WARNING "NFS: %s: sector not aligned\n", __func__);
+		return -1;
+	}
+	*sp = s >> SECTOR_SHIFT;
+	return 0;
+}
+
+static struct nfs4_deviceid_node *
+bl_find_get_deviceid(struct nfs_server *server,
+		const struct nfs4_deviceid *id, const struct cred *cred,
+		gfp_t gfp_mask)
+{
+	struct nfs4_deviceid_node *node;
+	unsigned long start, end;
+
+retry:
+	node = nfs4_find_get_deviceid(server, id, cred, gfp_mask);
+	if (!node)
+		return ERR_PTR(-ENODEV);
+
+	if (test_bit(NFS_DEVICEID_UNAVAILABLE, &node->flags) == 0)
+		return node;
+
+	end = jiffies;
+	start = end - PNFS_DEVICE_RETRY_TIMEOUT;
+	if (!time_in_range(node->timestamp_unavailable, start, end)) {
+		nfs4_delete_deviceid(node->ld, node->nfs_client, id);
+		goto retry;
+	}
+
+	nfs4_put_deviceid_node(node);
+	return ERR_PTR(-ENODEV);
+}
+
+static int
+bl_alloc_extent(struct xdr_stream *xdr, struct pnfs_layout_hdr *lo,
+		struct layout_verification *lv, struct list_head *extents,
+		gfp_t gfp_mask)
+{
+	struct pnfs_block_extent *be;
+	struct nfs4_deviceid id;
+	int error;
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, 28 + NFS4_DEVICEID4_SIZE);
+	if (!p)
+		return -EIO;
+
+	be = kzalloc(sizeof(*be), GFP_NOFS);
+	if (!be)
+		return -ENOMEM;
+
+	memcpy(&id, p, NFS4_DEVICEID4_SIZE);
+	p += XDR_QUADLEN(NFS4_DEVICEID4_SIZE);
+
+	be->be_device = bl_find_get_deviceid(NFS_SERVER(lo->plh_inode), &id,
+						lo->plh_lc_cred, gfp_mask);
+	if (IS_ERR(be->be_device)) {
+		error = PTR_ERR(be->be_device);
+		goto out_free_be;
+	}
+
+	/*
+	 * The next three values are read in as bytes, but stored in the
+	 * extent structure in 512-byte granularity.
+	 */
+	error = -EIO;
+	if (decode_sector_number(&p, &be->be_f_offset) < 0)
+		goto out_put_deviceid;
+	if (decode_sector_number(&p, &be->be_length) < 0)
+		goto out_put_deviceid;
+	if (decode_sector_number(&p, &be->be_v_offset) < 0)
+		goto out_put_deviceid;
+	be->be_state = be32_to_cpup(p++);
+
+	error = verify_extent(be, lv);
+	if (error) {
+		dprintk("%s: extent verification failed\n", __func__);
+		goto out_put_deviceid;
+	}
+
+	list_add_tail(&be->be_list, extents);
+	return 0;
+
+out_put_deviceid:
+	nfs4_put_deviceid_node(be->be_device);
+out_free_be:
+	kfree(be);
+	return error;
+}
+
+static struct pnfs_layout_segment *
+bl_alloc_lseg(struct pnfs_layout_hdr *lo, struct nfs4_layoutget_res *lgr,
+		gfp_t gfp_mask)
+{
+	struct layout_verification lv = {
+		.mode = lgr->range.iomode,
+		.start = lgr->range.offset >> SECTOR_SHIFT,
+		.inval = lgr->range.offset >> SECTOR_SHIFT,
+		.cowread = lgr->range.offset >> SECTOR_SHIFT,
+	};
+	struct pnfs_block_layout *bl = BLK_LO2EXT(lo);
+	struct pnfs_layout_segment *lseg;
+	struct xdr_buf buf;
+	struct xdr_stream xdr;
+	struct page *scratch;
+	int status, i;
+	uint32_t count;
+	__be32 *p;
+	LIST_HEAD(extents);
+
+	dprintk("---> %s\n", __func__);
+
+	lseg = kzalloc(sizeof(*lseg), gfp_mask);
+	if (!lseg)
+		return ERR_PTR(-ENOMEM);
+
+	status = -ENOMEM;
+	scratch = alloc_page(gfp_mask);
+	if (!scratch)
+		goto out;
+
+	xdr_init_decode_pages(&xdr, &buf,
+			lgr->layoutp->pages, lgr->layoutp->len);
+	xdr_set_scratch_buffer(&xdr, page_address(scratch), PAGE_SIZE);
+
+	status = -EIO;
+	p = xdr_inline_decode(&xdr, 4);
+	if (unlikely(!p))
+		goto out_free_scratch;
+
+	count = be32_to_cpup(p++);
+	dprintk("%s: number of extents %d\n", __func__, count);
+
+	/*
+	 * Decode individual extents, putting them in temporary staging area
+	 * until whole layout is decoded to make error recovery easier.
+	 */
+	for (i = 0; i < count; i++) {
+		status = bl_alloc_extent(&xdr, lo, &lv, &extents, gfp_mask);
+		if (status)
+			goto process_extents;
+	}
+
+	if (lgr->range.offset + lgr->range.length !=
+			lv.start << SECTOR_SHIFT) {
+		dprintk("%s Final length mismatch\n", __func__);
+		status = -EIO;
+		goto process_extents;
+	}
+
+	if (lv.start < lv.cowread) {
+		dprintk("%s Final uncovered COW extent\n", __func__);
+		status = -EIO;
+	}
+
+process_extents:
+	while (!list_empty(&extents)) {
+		struct pnfs_block_extent *be =
+			list_first_entry(&extents, struct pnfs_block_extent,
+					 be_list);
+		list_del(&be->be_list);
+
+		if (!status)
+			status = ext_tree_insert(bl, be);
+
+		if (status) {
+			nfs4_put_deviceid_node(be->be_device);
+			kfree(be);
+		}
+	}
+
+out_free_scratch:
+	__free_page(scratch);
+out:
+	dprintk("%s returns %d\n", __func__, status);
+	switch (status) {
+	case -ENODEV:
+		/* Our extent block devices are unavailable */
+		set_bit(NFS_LSEG_UNAVAILABLE, &lseg->pls_flags);
+		fallthrough;
+	case 0:
+		return lseg;
+	default:
+		kfree(lseg);
+		return ERR_PTR(status);
+	}
+}
+
+static void
+bl_return_range(struct pnfs_layout_hdr *lo,
+		struct pnfs_layout_range *range)
+{
+	struct pnfs_block_layout *bl = BLK_LO2EXT(lo);
+	sector_t offset = range->offset >> SECTOR_SHIFT, end;
+
+	if (range->offset % 8) {
+		dprintk("%s: offset %lld not block size aligned\n",
+			__func__, range->offset);
+		return;
+	}
+
+	if (range->length != NFS4_MAX_UINT64) {
+		if (range->length % 8) {
+			dprintk("%s: length %lld not block size aligned\n",
+				__func__, range->length);
+			return;
+		}
+
+		end = offset + (range->length >> SECTOR_SHIFT);
+	} else {
+		end = round_down(NFS4_MAX_UINT64, PAGE_SIZE);
+	}
+
+	ext_tree_remove(bl, range->iomode & IOMODE_RW, offset, end);
+}
+
+static int
+bl_prepare_layoutcommit(struct nfs4_layoutcommit_args *arg)
+{
+	return ext_tree_prepare_commit(arg);
+}
+
+static void
+bl_cleanup_layoutcommit(struct nfs4_layoutcommit_data *lcdata)
+{
+	ext_tree_mark_committed(&lcdata->args, lcdata->res.status);
+}
+
+static int
+bl_set_layoutdriver(struct nfs_server *server, const struct nfs_fh *fh)
+{
+	dprintk("%s enter\n", __func__);
+
+	if (server->pnfs_blksize == 0) {
+		dprintk("%s Server did not return blksize\n", __func__);
+		return -EINVAL;
+	}
+	if (server->pnfs_blksize > PAGE_SIZE) {
+		printk(KERN_ERR "%s: pNFS blksize %d not supported.\n",
+			__func__, server->pnfs_blksize);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static bool
+is_aligned_req(struct nfs_pageio_descriptor *pgio,
+		struct nfs_page *req, unsigned int alignment, bool is_write)
+{
+	/*
+	 * Always accept buffered writes, higher layers take care of the
+	 * right alignment.
+	 */
+	if (pgio->pg_dreq == NULL)
+		return true;
+
+	if (!IS_ALIGNED(req->wb_offset, alignment))
+		return false;
+
+	if (IS_ALIGNED(req->wb_bytes, alignment))
+		return true;
+
+	if (is_write &&
+	    (req_offset(req) + req->wb_bytes == i_size_read(pgio->pg_inode))) {
+		/*
+		 * If the write goes up to the inode size, just write
+		 * the full page.  Data past the inode size is
+		 * guaranteed to be zeroed by the higher level client
+		 * code, and this behaviour is mandated by RFC 5663
+		 * section 2.3.2.
+		 */
+		return true;
+	}
+
+	return false;
+}
+
+static void
+bl_pg_init_read(struct nfs_pageio_descriptor *pgio, struct nfs_page *req)
+{
+	if (!is_aligned_req(pgio, req, SECTOR_SIZE, false)) {
+		nfs_pageio_reset_read_mds(pgio);
+		return;
+	}
+
+	pnfs_generic_pg_init_read(pgio, req);
+
+	if (pgio->pg_lseg &&
+		test_bit(NFS_LSEG_UNAVAILABLE, &pgio->pg_lseg->pls_flags)) {
+		pnfs_error_mark_layout_for_return(pgio->pg_inode, pgio->pg_lseg);
+		pnfs_set_lo_fail(pgio->pg_lseg);
+		nfs_pageio_reset_read_mds(pgio);
+	}
+}
+
+/*
+ * Return 0 if @req cannot be coalesced into @pgio, otherwise return the number
+ * of bytes (maximum @req->wb_bytes) that can be coalesced.
+ */
+static size_t
+bl_pg_test_read(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev,
+		struct nfs_page *req)
+{
+	if (!is_aligned_req(pgio, req, SECTOR_SIZE, false))
+		return 0;
+	return pnfs_generic_pg_test(pgio, prev, req);
+}
+
+/*
+ * Return the number of contiguous bytes for a given inode
+ * starting at page frame idx.
+ */
+static u64 pnfs_num_cont_bytes(struct inode *inode, pgoff_t idx)
+{
+	struct address_space *mapping = inode->i_mapping;
+	pgoff_t end;
+
+	/* Optimize common case that writes from 0 to end of file */
+	end = DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE);
+	if (end != inode->i_mapping->nrpages) {
+		rcu_read_lock();
+		end = page_cache_next_miss(mapping, idx + 1, ULONG_MAX);
+		rcu_read_unlock();
+	}
+
+	if (!end)
+		return i_size_read(inode) - (idx << PAGE_SHIFT);
+	else
+		return (end - idx) << PAGE_SHIFT;
+}
+
+static void
+bl_pg_init_write(struct nfs_pageio_descriptor *pgio, struct nfs_page *req)
+{
+	u64 wb_size;
+
+	if (!is_aligned_req(pgio, req, PAGE_SIZE, true)) {
+		nfs_pageio_reset_write_mds(pgio);
+		return;
+	}
+
+	if (pgio->pg_dreq == NULL)
+		wb_size = pnfs_num_cont_bytes(pgio->pg_inode,
+					      req->wb_index);
+	else
+		wb_size = nfs_dreq_bytes_left(pgio->pg_dreq);
+
+	pnfs_generic_pg_init_write(pgio, req, wb_size);
+
+	if (pgio->pg_lseg &&
+		test_bit(NFS_LSEG_UNAVAILABLE, &pgio->pg_lseg->pls_flags)) {
+
+		pnfs_error_mark_layout_for_return(pgio->pg_inode, pgio->pg_lseg);
+		pnfs_set_lo_fail(pgio->pg_lseg);
+		nfs_pageio_reset_write_mds(pgio);
+	}
+}
+
+/*
+ * Return 0 if @req cannot be coalesced into @pgio, otherwise return the number
+ * of bytes (maximum @req->wb_bytes) that can be coalesced.
+ */
+static size_t
+bl_pg_test_write(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev,
+		 struct nfs_page *req)
+{
+	if (!is_aligned_req(pgio, req, PAGE_SIZE, true))
+		return 0;
+	return pnfs_generic_pg_test(pgio, prev, req);
+}
+
+static const struct nfs_pageio_ops bl_pg_read_ops = {
+	.pg_init = bl_pg_init_read,
+	.pg_test = bl_pg_test_read,
+	.pg_doio = pnfs_generic_pg_readpages,
+	.pg_cleanup = pnfs_generic_pg_cleanup,
+};
+
+static const struct nfs_pageio_ops bl_pg_write_ops = {
+	.pg_init = bl_pg_init_write,
+	.pg_test = bl_pg_test_write,
+	.pg_doio = pnfs_generic_pg_writepages,
+	.pg_cleanup = pnfs_generic_pg_cleanup,
+};
+
+static struct pnfs_layoutdriver_type blocklayout_type = {
+	.id				= LAYOUT_BLOCK_VOLUME,
+	.name				= "LAYOUT_BLOCK_VOLUME",
+	.owner				= THIS_MODULE,
+	.flags				= PNFS_LAYOUTRET_ON_SETATTR |
+					  PNFS_LAYOUTRET_ON_ERROR |
+					  PNFS_READ_WHOLE_PAGE,
+	.read_pagelist			= bl_read_pagelist,
+	.write_pagelist			= bl_write_pagelist,
+	.alloc_layout_hdr		= bl_alloc_layout_hdr,
+	.free_layout_hdr		= bl_free_layout_hdr,
+	.alloc_lseg			= bl_alloc_lseg,
+	.free_lseg			= bl_free_lseg,
+	.return_range			= bl_return_range,
+	.prepare_layoutcommit		= bl_prepare_layoutcommit,
+	.cleanup_layoutcommit		= bl_cleanup_layoutcommit,
+	.set_layoutdriver		= bl_set_layoutdriver,
+	.alloc_deviceid_node		= bl_alloc_deviceid_node,
+	.free_deviceid_node		= bl_free_deviceid_node,
+	.pg_read_ops			= &bl_pg_read_ops,
+	.pg_write_ops			= &bl_pg_write_ops,
+	.sync				= pnfs_generic_sync,
+};
+
+static struct pnfs_layoutdriver_type scsilayout_type = {
+	.id				= LAYOUT_SCSI,
+	.name				= "LAYOUT_SCSI",
+	.owner				= THIS_MODULE,
+	.flags				= PNFS_LAYOUTRET_ON_SETATTR |
+					  PNFS_LAYOUTRET_ON_ERROR |
+					  PNFS_READ_WHOLE_PAGE,
+	.read_pagelist			= bl_read_pagelist,
+	.write_pagelist			= bl_write_pagelist,
+	.alloc_layout_hdr		= sl_alloc_layout_hdr,
+	.free_layout_hdr		= bl_free_layout_hdr,
+	.alloc_lseg			= bl_alloc_lseg,
+	.free_lseg			= bl_free_lseg,
+	.return_range			= bl_return_range,
+	.prepare_layoutcommit		= bl_prepare_layoutcommit,
+	.cleanup_layoutcommit		= bl_cleanup_layoutcommit,
+	.set_layoutdriver		= bl_set_layoutdriver,
+	.alloc_deviceid_node		= bl_alloc_deviceid_node,
+	.free_deviceid_node		= bl_free_deviceid_node,
+	.pg_read_ops			= &bl_pg_read_ops,
+	.pg_write_ops			= &bl_pg_write_ops,
+	.sync				= pnfs_generic_sync,
+};
+
+
+static int __init nfs4blocklayout_init(void)
+{
+	int ret;
+
+	dprintk("%s: NFSv4 Block Layout Driver Registering...\n", __func__);
+
+	ret = bl_init_pipefs();
+	if (ret)
+		goto out;
+
+	ret = pnfs_register_layoutdriver(&blocklayout_type);
+	if (ret)
+		goto out_cleanup_pipe;
+
+	ret = pnfs_register_layoutdriver(&scsilayout_type);
+	if (ret)
+		goto out_unregister_block;
+	return 0;
+
+out_unregister_block:
+	pnfs_unregister_layoutdriver(&blocklayout_type);
+out_cleanup_pipe:
+	bl_cleanup_pipefs();
+out:
+	return ret;
+}
+
+static void __exit nfs4blocklayout_exit(void)
+{
+	dprintk("%s: NFSv4 Block Layout Driver Unregistering...\n",
+	       __func__);
+
+	pnfs_unregister_layoutdriver(&scsilayout_type);
+	pnfs_unregister_layoutdriver(&blocklayout_type);
+	bl_cleanup_pipefs();
+}
+
+MODULE_ALIAS("nfs-layouttype4-3");
+MODULE_ALIAS("nfs-layouttype4-5");
+
+module_init(nfs4blocklayout_init);
+module_exit(nfs4blocklayout_exit);
diff --git a/fs/nfs/blocklayout/blocklayout.h b/fs/nfs/blocklayout/blocklayout.h
new file mode 100644
index 000000000..716bc75e9
--- /dev/null
+++ b/fs/nfs/blocklayout/blocklayout.h
@@ -0,0 +1,197 @@
+/*
+ *  linux/fs/nfs/blocklayout/blocklayout.h
+ *
+ *  Module for the NFSv4.1 pNFS block layout driver.
+ *
+ *  Copyright (c) 2006 The Regents of the University of Michigan.
+ *  All rights reserved.
+ *
+ *  Andy Adamson <andros@citi.umich.edu>
+ *  Fred Isaman <iisaman@umich.edu>
+ *
+ * permission is granted to use, copy, create derivative works and
+ * redistribute this software and such derivative works for any purpose,
+ * so long as the name of the university of michigan is not used in
+ * any advertising or publicity pertaining to the use or distribution
+ * of this software without specific, written prior authorization.  if
+ * the above copyright notice or any other identification of the
+ * university of michigan is included in any copy of any portion of
+ * this software, then the disclaimer below must also be included.
+ *
+ * this software is provided as is, without representation from the
+ * university of michigan as to its fitness for any purpose, and without
+ * warranty by the university of michigan of any kind, either express
+ * or implied, including without limitation the implied warranties of
+ * merchantability and fitness for a particular purpose.  the regents
+ * of the university of michigan shall not be liable for any damages,
+ * including special, indirect, incidental, or consequential damages,
+ * with respect to any claim arising out or in connection with the use
+ * of the software, even if it has been or is hereafter advised of the
+ * possibility of such damages.
+ */
+#ifndef FS_NFS_NFS4BLOCKLAYOUT_H
+#define FS_NFS_NFS4BLOCKLAYOUT_H
+
+#include <linux/device-mapper.h>
+#include <linux/nfs_fs.h>
+#include <linux/sunrpc/rpc_pipe_fs.h>
+
+#include "../nfs4_fs.h"
+#include "../pnfs.h"
+#include "../netns.h"
+
+#define PAGE_CACHE_SECTORS (PAGE_SIZE >> SECTOR_SHIFT)
+#define PAGE_CACHE_SECTOR_SHIFT (PAGE_SHIFT - SECTOR_SHIFT)
+#define SECTOR_SIZE (1 << SECTOR_SHIFT)
+
+struct pnfs_block_dev;
+
+#define PNFS_BLOCK_MAX_UUIDS	4
+#define PNFS_BLOCK_MAX_DEVICES	64
+
+/*
+ * Random upper cap for the uuid length to avoid unbounded allocation.
+ * Not actually limited by the protocol.
+ */
+#define PNFS_BLOCK_UUID_LEN	128
+
+struct pnfs_block_volume {
+	enum pnfs_block_volume_type	type;
+	union {
+		struct {
+			int		len;
+			int		nr_sigs;
+			struct {
+				u64		offset;
+				u32		sig_len;
+				u8		sig[PNFS_BLOCK_UUID_LEN];
+			} sigs[PNFS_BLOCK_MAX_UUIDS];
+		} simple;
+		struct {
+			u64		start;
+			u64		len;
+			u32		volume;
+		} slice;
+		struct {
+			u32		volumes_count;
+			u32		volumes[PNFS_BLOCK_MAX_DEVICES];
+		} concat;
+		struct {
+			u64		chunk_size;
+			u32		volumes_count;
+			u32		volumes[PNFS_BLOCK_MAX_DEVICES];
+		} stripe;
+		struct {
+			enum scsi_code_set		code_set;
+			enum scsi_designator_type	designator_type;
+			int				designator_len;
+			u8				designator[256];
+			u64				pr_key;
+		} scsi;
+	};
+};
+
+struct pnfs_block_dev_map {
+	u64			start;
+	u64			len;
+	u64			disk_offset;
+	struct block_device		*bdev;
+};
+
+struct pnfs_block_dev {
+	struct nfs4_deviceid_node	node;
+
+	u64				start;
+	u64				len;
+
+	u32				nr_children;
+	struct pnfs_block_dev		*children;
+	u64				chunk_size;
+
+	struct block_device		*bdev;
+	u64				disk_offset;
+
+	u64				pr_key;
+	bool				pr_registered;
+
+	bool (*map)(struct pnfs_block_dev *dev, u64 offset,
+			struct pnfs_block_dev_map *map);
+};
+
+/* sector_t fields are all in 512-byte sectors */
+struct pnfs_block_extent {
+	union {
+		struct rb_node	be_node;
+		struct list_head be_list;
+	};
+	struct nfs4_deviceid_node *be_device;
+	sector_t	be_f_offset;	/* the starting offset in the file */
+	sector_t	be_length;	/* the size of the extent */
+	sector_t	be_v_offset;	/* the starting offset in the volume */
+	enum pnfs_block_extent_state be_state;	/* the state of this extent */
+#define EXTENT_WRITTEN		1
+#define EXTENT_COMMITTING	2
+	unsigned int	be_tag;
+};
+
+struct pnfs_block_layout {
+	struct pnfs_layout_hdr	bl_layout;
+	struct rb_root		bl_ext_rw;
+	struct rb_root		bl_ext_ro;
+	spinlock_t		bl_ext_lock;   /* Protects list manipulation */
+	bool			bl_scsi_layout;
+	u64			bl_lwb;
+};
+
+static inline struct pnfs_block_layout *
+BLK_LO2EXT(struct pnfs_layout_hdr *lo)
+{
+	return container_of(lo, struct pnfs_block_layout, bl_layout);
+}
+
+static inline struct pnfs_block_layout *
+BLK_LSEG2EXT(struct pnfs_layout_segment *lseg)
+{
+	return BLK_LO2EXT(lseg->pls_layout);
+}
+
+struct bl_pipe_msg {
+	struct rpc_pipe_msg msg;
+	wait_queue_head_t *bl_wq;
+};
+
+struct bl_msg_hdr {
+	u8  type;
+	u16 totallen; /* length of entire message, including hdr itself */
+};
+
+#define BL_DEVICE_UMOUNT               0x0 /* Umount--delete devices */
+#define BL_DEVICE_MOUNT                0x1 /* Mount--create devices*/
+#define BL_DEVICE_REQUEST_INIT         0x0 /* Start request */
+#define BL_DEVICE_REQUEST_PROC         0x1 /* User level process succeeds */
+#define BL_DEVICE_REQUEST_ERR          0x2 /* User level process fails */
+
+/* dev.c */
+struct nfs4_deviceid_node *bl_alloc_deviceid_node(struct nfs_server *server,
+		struct pnfs_device *pdev, gfp_t gfp_mask);
+void bl_free_deviceid_node(struct nfs4_deviceid_node *d);
+
+/* extent_tree.c */
+int ext_tree_insert(struct pnfs_block_layout *bl,
+		struct pnfs_block_extent *new);
+int ext_tree_remove(struct pnfs_block_layout *bl, bool rw, sector_t start,
+		sector_t end);
+int ext_tree_mark_written(struct pnfs_block_layout *bl, sector_t start,
+		sector_t len, u64 lwb);
+bool ext_tree_lookup(struct pnfs_block_layout *bl, sector_t isect,
+		struct pnfs_block_extent *ret, bool rw);
+int ext_tree_prepare_commit(struct nfs4_layoutcommit_args *arg);
+void ext_tree_mark_committed(struct nfs4_layoutcommit_args *arg, int status);
+
+/* rpc_pipefs.c */
+dev_t bl_resolve_deviceid(struct nfs_server *server,
+		struct pnfs_block_volume *b, gfp_t gfp_mask);
+int __init bl_init_pipefs(void);
+void bl_cleanup_pipefs(void);
+
+#endif /* FS_NFS_NFS4BLOCKLAYOUT_H */
diff --git a/fs/nfs/blocklayout/dev.c b/fs/nfs/blocklayout/dev.c
new file mode 100644
index 000000000..6e3a14fdf
--- /dev/null
+++ b/fs/nfs/blocklayout/dev.c
@@ -0,0 +1,548 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2014-2016 Christoph Hellwig.
+ */
+#include <linux/sunrpc/svc.h>
+#include <linux/blkdev.h>
+#include <linux/nfs4.h>
+#include <linux/nfs_fs.h>
+#include <linux/nfs_xdr.h>
+#include <linux/pr.h>
+
+#include "blocklayout.h"
+
+#define NFSDBG_FACILITY		NFSDBG_PNFS_LD
+
+static void
+bl_free_device(struct pnfs_block_dev *dev)
+{
+	if (dev->nr_children) {
+		int i;
+
+		for (i = 0; i < dev->nr_children; i++)
+			bl_free_device(&dev->children[i]);
+		kfree(dev->children);
+	} else {
+		if (dev->pr_registered) {
+			const struct pr_ops *ops =
+				dev->bdev->bd_disk->fops->pr_ops;
+			int error;
+
+			error = ops->pr_register(dev->bdev, dev->pr_key, 0,
+				false);
+			if (error)
+				pr_err("failed to unregister PR key.\n");
+		}
+
+		if (dev->bdev)
+			blkdev_put(dev->bdev, FMODE_READ | FMODE_WRITE);
+	}
+}
+
+void
+bl_free_deviceid_node(struct nfs4_deviceid_node *d)
+{
+	struct pnfs_block_dev *dev =
+		container_of(d, struct pnfs_block_dev, node);
+
+	bl_free_device(dev);
+	kfree_rcu(dev, node.rcu);
+}
+
+static int
+nfs4_block_decode_volume(struct xdr_stream *xdr, struct pnfs_block_volume *b)
+{
+	__be32 *p;
+	int i;
+
+	p = xdr_inline_decode(xdr, 4);
+	if (!p)
+		return -EIO;
+	b->type = be32_to_cpup(p++);
+
+	switch (b->type) {
+	case PNFS_BLOCK_VOLUME_SIMPLE:
+		p = xdr_inline_decode(xdr, 4);
+		if (!p)
+			return -EIO;
+		b->simple.nr_sigs = be32_to_cpup(p++);
+		if (!b->simple.nr_sigs || b->simple.nr_sigs > PNFS_BLOCK_MAX_UUIDS) {
+			dprintk("Bad signature count: %d\n", b->simple.nr_sigs);
+			return -EIO;
+		}
+
+		b->simple.len = 4 + 4;
+		for (i = 0; i < b->simple.nr_sigs; i++) {
+			p = xdr_inline_decode(xdr, 8 + 4);
+			if (!p)
+				return -EIO;
+			p = xdr_decode_hyper(p, &b->simple.sigs[i].offset);
+			b->simple.sigs[i].sig_len = be32_to_cpup(p++);
+			if (b->simple.sigs[i].sig_len > PNFS_BLOCK_UUID_LEN) {
+				pr_info("signature too long: %d\n",
+					b->simple.sigs[i].sig_len);
+				return -EIO;
+			}
+
+			p = xdr_inline_decode(xdr, b->simple.sigs[i].sig_len);
+			if (!p)
+				return -EIO;
+			memcpy(&b->simple.sigs[i].sig, p,
+				b->simple.sigs[i].sig_len);
+
+			b->simple.len += 8 + 4 + \
+				(XDR_QUADLEN(b->simple.sigs[i].sig_len) << 2);
+		}
+		break;
+	case PNFS_BLOCK_VOLUME_SLICE:
+		p = xdr_inline_decode(xdr, 8 + 8 + 4);
+		if (!p)
+			return -EIO;
+		p = xdr_decode_hyper(p, &b->slice.start);
+		p = xdr_decode_hyper(p, &b->slice.len);
+		b->slice.volume = be32_to_cpup(p++);
+		break;
+	case PNFS_BLOCK_VOLUME_CONCAT:
+		p = xdr_inline_decode(xdr, 4);
+		if (!p)
+			return -EIO;
+
+		b->concat.volumes_count = be32_to_cpup(p++);
+		if (b->concat.volumes_count > PNFS_BLOCK_MAX_DEVICES) {
+			dprintk("Too many volumes: %d\n", b->concat.volumes_count);
+			return -EIO;
+		}
+
+		p = xdr_inline_decode(xdr, b->concat.volumes_count * 4);
+		if (!p)
+			return -EIO;
+		for (i = 0; i < b->concat.volumes_count; i++)
+			b->concat.volumes[i] = be32_to_cpup(p++);
+		break;
+	case PNFS_BLOCK_VOLUME_STRIPE:
+		p = xdr_inline_decode(xdr, 8 + 4);
+		if (!p)
+			return -EIO;
+
+		p = xdr_decode_hyper(p, &b->stripe.chunk_size);
+		b->stripe.volumes_count = be32_to_cpup(p++);
+		if (b->stripe.volumes_count > PNFS_BLOCK_MAX_DEVICES) {
+			dprintk("Too many volumes: %d\n", b->stripe.volumes_count);
+			return -EIO;
+		}
+
+		p = xdr_inline_decode(xdr, b->stripe.volumes_count * 4);
+		if (!p)
+			return -EIO;
+		for (i = 0; i < b->stripe.volumes_count; i++)
+			b->stripe.volumes[i] = be32_to_cpup(p++);
+		break;
+	case PNFS_BLOCK_VOLUME_SCSI:
+		p = xdr_inline_decode(xdr, 4 + 4 + 4);
+		if (!p)
+			return -EIO;
+		b->scsi.code_set = be32_to_cpup(p++);
+		b->scsi.designator_type = be32_to_cpup(p++);
+		b->scsi.designator_len = be32_to_cpup(p++);
+		p = xdr_inline_decode(xdr, b->scsi.designator_len);
+		if (!p)
+			return -EIO;
+		if (b->scsi.designator_len > 256)
+			return -EIO;
+		memcpy(&b->scsi.designator, p, b->scsi.designator_len);
+		p = xdr_inline_decode(xdr, 8);
+		if (!p)
+			return -EIO;
+		p = xdr_decode_hyper(p, &b->scsi.pr_key);
+		break;
+	default:
+		dprintk("unknown volume type!\n");
+		return -EIO;
+	}
+
+	return 0;
+}
+
+static bool bl_map_simple(struct pnfs_block_dev *dev, u64 offset,
+		struct pnfs_block_dev_map *map)
+{
+	map->start = dev->start;
+	map->len = dev->len;
+	map->disk_offset = dev->disk_offset;
+	map->bdev = dev->bdev;
+	return true;
+}
+
+static bool bl_map_concat(struct pnfs_block_dev *dev, u64 offset,
+		struct pnfs_block_dev_map *map)
+{
+	int i;
+
+	for (i = 0; i < dev->nr_children; i++) {
+		struct pnfs_block_dev *child = &dev->children[i];
+
+		if (child->start > offset ||
+		    child->start + child->len <= offset)
+			continue;
+
+		child->map(child, offset - child->start, map);
+		return true;
+	}
+
+	dprintk("%s: ran off loop!\n", __func__);
+	return false;
+}
+
+static bool bl_map_stripe(struct pnfs_block_dev *dev, u64 offset,
+		struct pnfs_block_dev_map *map)
+{
+	struct pnfs_block_dev *child;
+	u64 chunk;
+	u32 chunk_idx;
+	u64 disk_offset;
+
+	chunk = div_u64(offset, dev->chunk_size);
+	div_u64_rem(chunk, dev->nr_children, &chunk_idx);
+
+	if (chunk_idx >= dev->nr_children) {
+		dprintk("%s: invalid chunk idx %d (%lld/%lld)\n",
+			__func__, chunk_idx, offset, dev->chunk_size);
+		/* error, should not happen */
+		return false;
+	}
+
+	/* truncate offset to the beginning of the stripe */
+	offset = chunk * dev->chunk_size;
+
+	/* disk offset of the stripe */
+	disk_offset = div_u64(offset, dev->nr_children);
+
+	child = &dev->children[chunk_idx];
+	child->map(child, disk_offset, map);
+
+	map->start += offset;
+	map->disk_offset += disk_offset;
+	map->len = dev->chunk_size;
+	return true;
+}
+
+static int
+bl_parse_deviceid(struct nfs_server *server, struct pnfs_block_dev *d,
+		struct pnfs_block_volume *volumes, int idx, gfp_t gfp_mask);
+
+
+static int
+bl_parse_simple(struct nfs_server *server, struct pnfs_block_dev *d,
+		struct pnfs_block_volume *volumes, int idx, gfp_t gfp_mask)
+{
+	struct pnfs_block_volume *v = &volumes[idx];
+	struct block_device *bdev;
+	dev_t dev;
+
+	dev = bl_resolve_deviceid(server, v, gfp_mask);
+	if (!dev)
+		return -EIO;
+
+	bdev = blkdev_get_by_dev(dev, FMODE_READ | FMODE_WRITE, NULL);
+	if (IS_ERR(bdev)) {
+		printk(KERN_WARNING "pNFS: failed to open device %d:%d (%ld)\n",
+			MAJOR(dev), MINOR(dev), PTR_ERR(bdev));
+		return PTR_ERR(bdev);
+	}
+	d->bdev = bdev;
+
+
+	d->len = i_size_read(d->bdev->bd_inode);
+	d->map = bl_map_simple;
+
+	printk(KERN_INFO "pNFS: using block device %s\n",
+		d->bdev->bd_disk->disk_name);
+	return 0;
+}
+
+static bool
+bl_validate_designator(struct pnfs_block_volume *v)
+{
+	switch (v->scsi.designator_type) {
+	case PS_DESIGNATOR_EUI64:
+		if (v->scsi.code_set != PS_CODE_SET_BINARY)
+			return false;
+
+		if (v->scsi.designator_len != 8 &&
+		    v->scsi.designator_len != 10 &&
+		    v->scsi.designator_len != 16)
+			return false;
+
+		return true;
+	case PS_DESIGNATOR_NAA:
+		if (v->scsi.code_set != PS_CODE_SET_BINARY)
+			return false;
+
+		if (v->scsi.designator_len != 8 &&
+		    v->scsi.designator_len != 16)
+			return false;
+
+		return true;
+	case PS_DESIGNATOR_T10:
+	case PS_DESIGNATOR_NAME:
+		pr_err("pNFS: unsupported designator "
+			"(code set %d, type %d, len %d.\n",
+			v->scsi.code_set,
+			v->scsi.designator_type,
+			v->scsi.designator_len);
+		return false;
+	default:
+		pr_err("pNFS: invalid designator "
+			"(code set %d, type %d, len %d.\n",
+			v->scsi.code_set,
+			v->scsi.designator_type,
+			v->scsi.designator_len);
+		return false;
+	}
+}
+
+/*
+ * Try to open the udev path for the WWN.  At least on Debian the udev
+ * by-id path will always point to the dm-multipath device if one exists.
+ */
+static struct block_device *
+bl_open_udev_path(struct pnfs_block_volume *v)
+{
+	struct block_device *bdev;
+	const char *devname;
+
+	devname = kasprintf(GFP_KERNEL, "/dev/disk/by-id/wwn-0x%*phN",
+				v->scsi.designator_len, v->scsi.designator);
+	if (!devname)
+		return ERR_PTR(-ENOMEM);
+
+	bdev = blkdev_get_by_path(devname, FMODE_READ | FMODE_WRITE, NULL);
+	if (IS_ERR(bdev)) {
+		pr_warn("pNFS: failed to open device %s (%ld)\n",
+			devname, PTR_ERR(bdev));
+	}
+
+	kfree(devname);
+	return bdev;
+}
+
+/*
+ * Try to open the RH/Fedora specific dm-mpath udev path for this WWN, as the
+ * wwn- links will only point to the first discovered SCSI device there.
+ */
+static struct block_device *
+bl_open_dm_mpath_udev_path(struct pnfs_block_volume *v)
+{
+	struct block_device *bdev;
+	const char *devname;
+
+	devname = kasprintf(GFP_KERNEL,
+			"/dev/disk/by-id/dm-uuid-mpath-%d%*phN",
+			v->scsi.designator_type,
+			v->scsi.designator_len, v->scsi.designator);
+	if (!devname)
+		return ERR_PTR(-ENOMEM);
+
+	bdev = blkdev_get_by_path(devname, FMODE_READ | FMODE_WRITE, NULL);
+	kfree(devname);
+	return bdev;
+}
+
+static int
+bl_parse_scsi(struct nfs_server *server, struct pnfs_block_dev *d,
+		struct pnfs_block_volume *volumes, int idx, gfp_t gfp_mask)
+{
+	struct pnfs_block_volume *v = &volumes[idx];
+	struct block_device *bdev;
+	const struct pr_ops *ops;
+	int error;
+
+	if (!bl_validate_designator(v))
+		return -EINVAL;
+
+	bdev = bl_open_dm_mpath_udev_path(v);
+	if (IS_ERR(bdev))
+		bdev = bl_open_udev_path(v);
+	if (IS_ERR(bdev))
+		return PTR_ERR(bdev);
+	d->bdev = bdev;
+
+	d->len = i_size_read(d->bdev->bd_inode);
+	d->map = bl_map_simple;
+	d->pr_key = v->scsi.pr_key;
+
+	pr_info("pNFS: using block device %s (reservation key 0x%llx)\n",
+		d->bdev->bd_disk->disk_name, d->pr_key);
+
+	ops = d->bdev->bd_disk->fops->pr_ops;
+	if (!ops) {
+		pr_err("pNFS: block device %s does not support reservations.",
+				d->bdev->bd_disk->disk_name);
+		error = -EINVAL;
+		goto out_blkdev_put;
+	}
+
+	error = ops->pr_register(d->bdev, 0, d->pr_key, true);
+	if (error) {
+		pr_err("pNFS: failed to register key for block device %s.",
+				d->bdev->bd_disk->disk_name);
+		goto out_blkdev_put;
+	}
+
+	d->pr_registered = true;
+	return 0;
+
+out_blkdev_put:
+	blkdev_put(d->bdev, FMODE_READ | FMODE_WRITE);
+	return error;
+}
+
+static int
+bl_parse_slice(struct nfs_server *server, struct pnfs_block_dev *d,
+		struct pnfs_block_volume *volumes, int idx, gfp_t gfp_mask)
+{
+	struct pnfs_block_volume *v = &volumes[idx];
+	int ret;
+
+	ret = bl_parse_deviceid(server, d, volumes, v->slice.volume, gfp_mask);
+	if (ret)
+		return ret;
+
+	d->disk_offset = v->slice.start;
+	d->len = v->slice.len;
+	return 0;
+}
+
+static int
+bl_parse_concat(struct nfs_server *server, struct pnfs_block_dev *d,
+		struct pnfs_block_volume *volumes, int idx, gfp_t gfp_mask)
+{
+	struct pnfs_block_volume *v = &volumes[idx];
+	u64 len = 0;
+	int ret, i;
+
+	d->children = kcalloc(v->concat.volumes_count,
+			sizeof(struct pnfs_block_dev), gfp_mask);
+	if (!d->children)
+		return -ENOMEM;
+
+	for (i = 0; i < v->concat.volumes_count; i++) {
+		ret = bl_parse_deviceid(server, &d->children[i],
+				volumes, v->concat.volumes[i], gfp_mask);
+		if (ret)
+			return ret;
+
+		d->nr_children++;
+		d->children[i].start += len;
+		len += d->children[i].len;
+	}
+
+	d->len = len;
+	d->map = bl_map_concat;
+	return 0;
+}
+
+static int
+bl_parse_stripe(struct nfs_server *server, struct pnfs_block_dev *d,
+		struct pnfs_block_volume *volumes, int idx, gfp_t gfp_mask)
+{
+	struct pnfs_block_volume *v = &volumes[idx];
+	u64 len = 0;
+	int ret, i;
+
+	d->children = kcalloc(v->stripe.volumes_count,
+			sizeof(struct pnfs_block_dev), gfp_mask);
+	if (!d->children)
+		return -ENOMEM;
+
+	for (i = 0; i < v->stripe.volumes_count; i++) {
+		ret = bl_parse_deviceid(server, &d->children[i],
+				volumes, v->stripe.volumes[i], gfp_mask);
+		if (ret)
+			return ret;
+
+		d->nr_children++;
+		len += d->children[i].len;
+	}
+
+	d->len = len;
+	d->chunk_size = v->stripe.chunk_size;
+	d->map = bl_map_stripe;
+	return 0;
+}
+
+static int
+bl_parse_deviceid(struct nfs_server *server, struct pnfs_block_dev *d,
+		struct pnfs_block_volume *volumes, int idx, gfp_t gfp_mask)
+{
+	switch (volumes[idx].type) {
+	case PNFS_BLOCK_VOLUME_SIMPLE:
+		return bl_parse_simple(server, d, volumes, idx, gfp_mask);
+	case PNFS_BLOCK_VOLUME_SLICE:
+		return bl_parse_slice(server, d, volumes, idx, gfp_mask);
+	case PNFS_BLOCK_VOLUME_CONCAT:
+		return bl_parse_concat(server, d, volumes, idx, gfp_mask);
+	case PNFS_BLOCK_VOLUME_STRIPE:
+		return bl_parse_stripe(server, d, volumes, idx, gfp_mask);
+	case PNFS_BLOCK_VOLUME_SCSI:
+		return bl_parse_scsi(server, d, volumes, idx, gfp_mask);
+	default:
+		dprintk("unsupported volume type: %d\n", volumes[idx].type);
+		return -EIO;
+	}
+}
+
+struct nfs4_deviceid_node *
+bl_alloc_deviceid_node(struct nfs_server *server, struct pnfs_device *pdev,
+		gfp_t gfp_mask)
+{
+	struct nfs4_deviceid_node *node = NULL;
+	struct pnfs_block_volume *volumes;
+	struct pnfs_block_dev *top;
+	struct xdr_stream xdr;
+	struct xdr_buf buf;
+	struct page *scratch;
+	int nr_volumes, ret, i;
+	__be32 *p;
+
+	scratch = alloc_page(gfp_mask);
+	if (!scratch)
+		goto out;
+
+	xdr_init_decode_pages(&xdr, &buf, pdev->pages, pdev->pglen);
+	xdr_set_scratch_buffer(&xdr, page_address(scratch), PAGE_SIZE);
+
+	p = xdr_inline_decode(&xdr, sizeof(__be32));
+	if (!p)
+		goto out_free_scratch;
+	nr_volumes = be32_to_cpup(p++);
+
+	volumes = kcalloc(nr_volumes, sizeof(struct pnfs_block_volume),
+			  gfp_mask);
+	if (!volumes)
+		goto out_free_scratch;
+
+	for (i = 0; i < nr_volumes; i++) {
+		ret = nfs4_block_decode_volume(&xdr, &volumes[i]);
+		if (ret < 0)
+			goto out_free_volumes;
+	}
+
+	top = kzalloc(sizeof(*top), gfp_mask);
+	if (!top)
+		goto out_free_volumes;
+
+	ret = bl_parse_deviceid(server, top, volumes, nr_volumes - 1, gfp_mask);
+
+	node = &top->node;
+	nfs4_init_deviceid_node(node, server, &pdev->dev_id);
+	if (ret)
+		nfs4_mark_deviceid_unavailable(node);
+
+out_free_volumes:
+	kfree(volumes);
+out_free_scratch:
+	__free_page(scratch);
+out:
+	return node;
+}
diff --git a/fs/nfs/blocklayout/extent_tree.c b/fs/nfs/blocklayout/extent_tree.c
new file mode 100644
index 000000000..8f7cff7a4
--- /dev/null
+++ b/fs/nfs/blocklayout/extent_tree.c
@@ -0,0 +1,647 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2014-2016 Christoph Hellwig.
+ */
+
+#include <linux/vmalloc.h>
+
+#include "blocklayout.h"
+
+#define NFSDBG_FACILITY		NFSDBG_PNFS_LD
+
+static inline struct pnfs_block_extent *
+ext_node(struct rb_node *node)
+{
+	return rb_entry(node, struct pnfs_block_extent, be_node);
+}
+
+static struct pnfs_block_extent *
+ext_tree_first(struct rb_root *root)
+{
+	struct rb_node *node = rb_first(root);
+	return node ? ext_node(node) : NULL;
+}
+
+static struct pnfs_block_extent *
+ext_tree_prev(struct pnfs_block_extent *be)
+{
+	struct rb_node *node = rb_prev(&be->be_node);
+	return node ? ext_node(node) : NULL;
+}
+
+static struct pnfs_block_extent *
+ext_tree_next(struct pnfs_block_extent *be)
+{
+	struct rb_node *node = rb_next(&be->be_node);
+	return node ? ext_node(node) : NULL;
+}
+
+static inline sector_t
+ext_f_end(struct pnfs_block_extent *be)
+{
+	return be->be_f_offset + be->be_length;
+}
+
+static struct pnfs_block_extent *
+__ext_tree_search(struct rb_root *root, sector_t start)
+{
+	struct rb_node *node = root->rb_node;
+	struct pnfs_block_extent *be = NULL;
+
+	while (node) {
+		be = ext_node(node);
+		if (start < be->be_f_offset)
+			node = node->rb_left;
+		else if (start >= ext_f_end(be))
+			node = node->rb_right;
+		else
+			return be;
+	}
+
+	if (be) {
+		if (start < be->be_f_offset)
+			return be;
+
+		if (start >= ext_f_end(be))
+			return ext_tree_next(be);
+	}
+
+	return NULL;
+}
+
+static bool
+ext_can_merge(struct pnfs_block_extent *be1, struct pnfs_block_extent *be2)
+{
+	if (be1->be_state != be2->be_state)
+		return false;
+	if (be1->be_device != be2->be_device)
+		return false;
+
+	if (be1->be_f_offset + be1->be_length != be2->be_f_offset)
+		return false;
+
+	if (be1->be_state != PNFS_BLOCK_NONE_DATA &&
+	    (be1->be_v_offset + be1->be_length != be2->be_v_offset))
+		return false;
+
+	if (be1->be_state == PNFS_BLOCK_INVALID_DATA &&
+	    be1->be_tag != be2->be_tag)
+		return false;
+
+	return true;
+}
+
+static struct pnfs_block_extent *
+ext_try_to_merge_left(struct rb_root *root, struct pnfs_block_extent *be)
+{
+	struct pnfs_block_extent *left = ext_tree_prev(be);
+
+	if (left && ext_can_merge(left, be)) {
+		left->be_length += be->be_length;
+		rb_erase(&be->be_node, root);
+		nfs4_put_deviceid_node(be->be_device);
+		kfree(be);
+		return left;
+	}
+
+	return be;
+}
+
+static struct pnfs_block_extent *
+ext_try_to_merge_right(struct rb_root *root, struct pnfs_block_extent *be)
+{
+	struct pnfs_block_extent *right = ext_tree_next(be);
+
+	if (right && ext_can_merge(be, right)) {
+		be->be_length += right->be_length;
+		rb_erase(&right->be_node, root);
+		nfs4_put_deviceid_node(right->be_device);
+		kfree(right);
+	}
+
+	return be;
+}
+
+static void __ext_put_deviceids(struct list_head *head)
+{
+	struct pnfs_block_extent *be, *tmp;
+
+	list_for_each_entry_safe(be, tmp, head, be_list) {
+		nfs4_put_deviceid_node(be->be_device);
+		kfree(be);
+	}
+}
+
+static void
+__ext_tree_insert(struct rb_root *root,
+		struct pnfs_block_extent *new, bool merge_ok)
+{
+	struct rb_node **p = &root->rb_node, *parent = NULL;
+	struct pnfs_block_extent *be;
+
+	while (*p) {
+		parent = *p;
+		be = ext_node(parent);
+
+		if (new->be_f_offset < be->be_f_offset) {
+			if (merge_ok && ext_can_merge(new, be)) {
+				be->be_f_offset = new->be_f_offset;
+				if (be->be_state != PNFS_BLOCK_NONE_DATA)
+					be->be_v_offset = new->be_v_offset;
+				be->be_length += new->be_length;
+				be = ext_try_to_merge_left(root, be);
+				goto free_new;
+			}
+			p = &(*p)->rb_left;
+		} else if (new->be_f_offset >= ext_f_end(be)) {
+			if (merge_ok && ext_can_merge(be, new)) {
+				be->be_length += new->be_length;
+				be = ext_try_to_merge_right(root, be);
+				goto free_new;
+			}
+			p = &(*p)->rb_right;
+		} else {
+			BUG();
+		}
+	}
+
+	rb_link_node(&new->be_node, parent, p);
+	rb_insert_color(&new->be_node, root);
+	return;
+free_new:
+	nfs4_put_deviceid_node(new->be_device);
+	kfree(new);
+}
+
+static int
+__ext_tree_remove(struct rb_root *root,
+		sector_t start, sector_t end, struct list_head *tmp)
+{
+	struct pnfs_block_extent *be;
+	sector_t len1 = 0, len2 = 0;
+	sector_t orig_v_offset;
+	sector_t orig_len;
+
+	be = __ext_tree_search(root, start);
+	if (!be)
+		return 0;
+	if (be->be_f_offset >= end)
+		return 0;
+
+	orig_v_offset = be->be_v_offset;
+	orig_len = be->be_length;
+
+	if (start > be->be_f_offset)
+		len1 = start - be->be_f_offset;
+	if (ext_f_end(be) > end)
+		len2 = ext_f_end(be) - end;
+
+	if (len2 > 0) {
+		if (len1 > 0) {
+			struct pnfs_block_extent *new;
+
+			new = kzalloc(sizeof(*new), GFP_ATOMIC);
+			if (!new)
+				return -ENOMEM;
+
+			be->be_length = len1;
+
+			new->be_f_offset = end;
+			if (be->be_state != PNFS_BLOCK_NONE_DATA) {
+				new->be_v_offset =
+					orig_v_offset + orig_len - len2;
+			}
+			new->be_length = len2;
+			new->be_state = be->be_state;
+			new->be_tag = be->be_tag;
+			new->be_device = nfs4_get_deviceid(be->be_device);
+
+			__ext_tree_insert(root, new, true);
+		} else {
+			be->be_f_offset = end;
+			if (be->be_state != PNFS_BLOCK_NONE_DATA) {
+				be->be_v_offset =
+					orig_v_offset + orig_len - len2;
+			}
+			be->be_length = len2;
+		}
+	} else {
+		if (len1 > 0) {
+			be->be_length = len1;
+			be = ext_tree_next(be);
+		}
+
+		while (be && ext_f_end(be) <= end) {
+			struct pnfs_block_extent *next = ext_tree_next(be);
+
+			rb_erase(&be->be_node, root);
+			list_add_tail(&be->be_list, tmp);
+			be = next;
+		}
+
+		if (be && be->be_f_offset < end) {
+			len1 = ext_f_end(be) - end;
+			be->be_f_offset = end;
+			if (be->be_state != PNFS_BLOCK_NONE_DATA)
+				be->be_v_offset += be->be_length - len1;
+			be->be_length = len1;
+		}
+	}
+
+	return 0;
+}
+
+int
+ext_tree_insert(struct pnfs_block_layout *bl, struct pnfs_block_extent *new)
+{
+	struct pnfs_block_extent *be;
+	struct rb_root *root;
+	int err = 0;
+
+	switch (new->be_state) {
+	case PNFS_BLOCK_READWRITE_DATA:
+	case PNFS_BLOCK_INVALID_DATA:
+		root = &bl->bl_ext_rw;
+		break;
+	case PNFS_BLOCK_READ_DATA:
+	case PNFS_BLOCK_NONE_DATA:
+		root = &bl->bl_ext_ro;
+		break;
+	default:
+		dprintk("invalid extent type\n");
+		return -EINVAL;
+	}
+
+	spin_lock(&bl->bl_ext_lock);
+retry:
+	be = __ext_tree_search(root, new->be_f_offset);
+	if (!be || be->be_f_offset >= ext_f_end(new)) {
+		__ext_tree_insert(root, new, true);
+	} else if (new->be_f_offset >= be->be_f_offset) {
+		if (ext_f_end(new) <= ext_f_end(be)) {
+			nfs4_put_deviceid_node(new->be_device);
+			kfree(new);
+		} else {
+			sector_t new_len = ext_f_end(new) - ext_f_end(be);
+			sector_t diff = new->be_length - new_len;
+
+			new->be_f_offset += diff;
+			new->be_v_offset += diff;
+			new->be_length = new_len;
+			goto retry;
+		}
+	} else if (ext_f_end(new) <= ext_f_end(be)) {
+		new->be_length = be->be_f_offset - new->be_f_offset;
+		__ext_tree_insert(root, new, true);
+	} else {
+		struct pnfs_block_extent *split;
+		sector_t new_len = ext_f_end(new) - ext_f_end(be);
+		sector_t diff = new->be_length - new_len;
+
+		split = kmemdup(new, sizeof(*new), GFP_ATOMIC);
+		if (!split) {
+			err = -EINVAL;
+			goto out;
+		}
+
+		split->be_length = be->be_f_offset - split->be_f_offset;
+		split->be_device = nfs4_get_deviceid(new->be_device);
+		__ext_tree_insert(root, split, true);
+
+		new->be_f_offset += diff;
+		new->be_v_offset += diff;
+		new->be_length = new_len;
+		goto retry;
+	}
+out:
+	spin_unlock(&bl->bl_ext_lock);
+	return err;
+}
+
+static bool
+__ext_tree_lookup(struct rb_root *root, sector_t isect,
+		struct pnfs_block_extent *ret)
+{
+	struct rb_node *node;
+	struct pnfs_block_extent *be;
+
+	node = root->rb_node;
+	while (node) {
+		be = ext_node(node);
+		if (isect < be->be_f_offset)
+			node = node->rb_left;
+		else if (isect >= ext_f_end(be))
+			node = node->rb_right;
+		else {
+			*ret = *be;
+			return true;
+		}
+	}
+
+	return false;
+}
+
+bool
+ext_tree_lookup(struct pnfs_block_layout *bl, sector_t isect,
+	    struct pnfs_block_extent *ret, bool rw)
+{
+	bool found = false;
+
+	spin_lock(&bl->bl_ext_lock);
+	if (!rw)
+		found = __ext_tree_lookup(&bl->bl_ext_ro, isect, ret);
+	if (!found)
+		found = __ext_tree_lookup(&bl->bl_ext_rw, isect, ret);
+	spin_unlock(&bl->bl_ext_lock);
+
+	return found;
+}
+
+int ext_tree_remove(struct pnfs_block_layout *bl, bool rw,
+		sector_t start, sector_t end)
+{
+	int err, err2;
+	LIST_HEAD(tmp);
+
+	spin_lock(&bl->bl_ext_lock);
+	err = __ext_tree_remove(&bl->bl_ext_ro, start, end, &tmp);
+	if (rw) {
+		err2 = __ext_tree_remove(&bl->bl_ext_rw, start, end, &tmp);
+		if (!err)
+			err = err2;
+	}
+	spin_unlock(&bl->bl_ext_lock);
+
+	__ext_put_deviceids(&tmp);
+	return err;
+}
+
+static int
+ext_tree_split(struct rb_root *root, struct pnfs_block_extent *be,
+		sector_t split)
+{
+	struct pnfs_block_extent *new;
+	sector_t orig_len = be->be_length;
+
+	new = kzalloc(sizeof(*new), GFP_ATOMIC);
+	if (!new)
+		return -ENOMEM;
+
+	be->be_length = split - be->be_f_offset;
+
+	new->be_f_offset = split;
+	if (be->be_state != PNFS_BLOCK_NONE_DATA)
+		new->be_v_offset = be->be_v_offset + be->be_length;
+	new->be_length = orig_len - be->be_length;
+	new->be_state = be->be_state;
+	new->be_tag = be->be_tag;
+	new->be_device = nfs4_get_deviceid(be->be_device);
+
+	__ext_tree_insert(root, new, false);
+	return 0;
+}
+
+int
+ext_tree_mark_written(struct pnfs_block_layout *bl, sector_t start,
+		sector_t len, u64 lwb)
+{
+	struct rb_root *root = &bl->bl_ext_rw;
+	sector_t end = start + len;
+	struct pnfs_block_extent *be;
+	int err = 0;
+	LIST_HEAD(tmp);
+
+	spin_lock(&bl->bl_ext_lock);
+	/*
+	 * First remove all COW extents or holes from written to range.
+	 */
+	err = __ext_tree_remove(&bl->bl_ext_ro, start, end, &tmp);
+	if (err)
+		goto out;
+
+	/*
+	 * Then mark all invalid extents in the range as written to.
+	 */
+	for (be = __ext_tree_search(root, start); be; be = ext_tree_next(be)) {
+		if (be->be_f_offset >= end)
+			break;
+
+		if (be->be_state != PNFS_BLOCK_INVALID_DATA || be->be_tag)
+			continue;
+
+		if (be->be_f_offset < start) {
+			struct pnfs_block_extent *left = ext_tree_prev(be);
+
+			if (left && ext_can_merge(left, be)) {
+				sector_t diff = start - be->be_f_offset;
+
+				left->be_length += diff;
+
+				be->be_f_offset += diff;
+				be->be_v_offset += diff;
+				be->be_length -= diff;
+			} else {
+				err = ext_tree_split(root, be, start);
+				if (err)
+					goto out;
+			}
+		}
+
+		if (ext_f_end(be) > end) {
+			struct pnfs_block_extent *right = ext_tree_next(be);
+
+			if (right && ext_can_merge(be, right)) {
+				sector_t diff = end - be->be_f_offset;
+
+				be->be_length -= diff;
+
+				right->be_f_offset -= diff;
+				right->be_v_offset -= diff;
+				right->be_length += diff;
+			} else {
+				err = ext_tree_split(root, be, end);
+				if (err)
+					goto out;
+			}
+		}
+
+		if (be->be_f_offset >= start && ext_f_end(be) <= end) {
+			be->be_tag = EXTENT_WRITTEN;
+			be = ext_try_to_merge_left(root, be);
+			be = ext_try_to_merge_right(root, be);
+		}
+	}
+out:
+	if (bl->bl_lwb < lwb)
+		bl->bl_lwb = lwb;
+	spin_unlock(&bl->bl_ext_lock);
+
+	__ext_put_deviceids(&tmp);
+	return err;
+}
+
+static size_t ext_tree_layoutupdate_size(struct pnfs_block_layout *bl, size_t count)
+{
+	if (bl->bl_scsi_layout)
+		return sizeof(__be32) + PNFS_SCSI_RANGE_SIZE * count;
+	else
+		return sizeof(__be32) + PNFS_BLOCK_EXTENT_SIZE * count;
+}
+
+static void ext_tree_free_commitdata(struct nfs4_layoutcommit_args *arg,
+		size_t buffer_size)
+{
+	if (arg->layoutupdate_pages != &arg->layoutupdate_page) {
+		int nr_pages = DIV_ROUND_UP(buffer_size, PAGE_SIZE), i;
+
+		for (i = 0; i < nr_pages; i++)
+			put_page(arg->layoutupdate_pages[i]);
+		vfree(arg->start_p);
+		kfree(arg->layoutupdate_pages);
+	} else {
+		put_page(arg->layoutupdate_page);
+	}
+}
+
+static __be32 *encode_block_extent(struct pnfs_block_extent *be, __be32 *p)
+{
+	p = xdr_encode_opaque_fixed(p, be->be_device->deviceid.data,
+			NFS4_DEVICEID4_SIZE);
+	p = xdr_encode_hyper(p, be->be_f_offset << SECTOR_SHIFT);
+	p = xdr_encode_hyper(p, be->be_length << SECTOR_SHIFT);
+	p = xdr_encode_hyper(p, 0LL);
+	*p++ = cpu_to_be32(PNFS_BLOCK_READWRITE_DATA);
+	return p;
+}
+
+static __be32 *encode_scsi_range(struct pnfs_block_extent *be, __be32 *p)
+{
+	p = xdr_encode_hyper(p, be->be_f_offset << SECTOR_SHIFT);
+	return xdr_encode_hyper(p, be->be_length << SECTOR_SHIFT);
+}
+
+static int ext_tree_encode_commit(struct pnfs_block_layout *bl, __be32 *p,
+		size_t buffer_size, size_t *count, __u64 *lastbyte)
+{
+	struct pnfs_block_extent *be;
+	int ret = 0;
+
+	spin_lock(&bl->bl_ext_lock);
+	for (be = ext_tree_first(&bl->bl_ext_rw); be; be = ext_tree_next(be)) {
+		if (be->be_state != PNFS_BLOCK_INVALID_DATA ||
+		    be->be_tag != EXTENT_WRITTEN)
+			continue;
+
+		(*count)++;
+		if (ext_tree_layoutupdate_size(bl, *count) > buffer_size) {
+			/* keep counting.. */
+			ret = -ENOSPC;
+			continue;
+		}
+
+		if (bl->bl_scsi_layout)
+			p = encode_scsi_range(be, p);
+		else
+			p = encode_block_extent(be, p);
+		be->be_tag = EXTENT_COMMITTING;
+	}
+	*lastbyte = bl->bl_lwb - 1;
+	bl->bl_lwb = 0;
+	spin_unlock(&bl->bl_ext_lock);
+
+	return ret;
+}
+
+int
+ext_tree_prepare_commit(struct nfs4_layoutcommit_args *arg)
+{
+	struct pnfs_block_layout *bl = BLK_LO2EXT(NFS_I(arg->inode)->layout);
+	size_t count = 0, buffer_size = PAGE_SIZE;
+	__be32 *start_p;
+	int ret;
+
+	dprintk("%s enter\n", __func__);
+
+	arg->layoutupdate_page = alloc_page(GFP_NOFS);
+	if (!arg->layoutupdate_page)
+		return -ENOMEM;
+	start_p = page_address(arg->layoutupdate_page);
+	arg->layoutupdate_pages = &arg->layoutupdate_page;
+
+retry:
+	ret = ext_tree_encode_commit(bl, start_p + 1, buffer_size, &count, &arg->lastbytewritten);
+	if (unlikely(ret)) {
+		ext_tree_free_commitdata(arg, buffer_size);
+
+		buffer_size = ext_tree_layoutupdate_size(bl, count);
+		count = 0;
+
+		arg->layoutupdate_pages =
+			kcalloc(DIV_ROUND_UP(buffer_size, PAGE_SIZE),
+				sizeof(struct page *), GFP_NOFS);
+		if (!arg->layoutupdate_pages)
+			return -ENOMEM;
+
+		start_p = __vmalloc(buffer_size, GFP_NOFS);
+		if (!start_p) {
+			kfree(arg->layoutupdate_pages);
+			return -ENOMEM;
+		}
+
+		goto retry;
+	}
+
+	*start_p = cpu_to_be32(count);
+	arg->layoutupdate_len = ext_tree_layoutupdate_size(bl, count);
+
+	if (unlikely(arg->layoutupdate_pages != &arg->layoutupdate_page)) {
+		void *p = start_p, *end = p + arg->layoutupdate_len;
+		struct page *page = NULL;
+		int i = 0;
+
+		arg->start_p = start_p;
+		for ( ; p < end; p += PAGE_SIZE) {
+			page = vmalloc_to_page(p);
+			arg->layoutupdate_pages[i++] = page;
+			get_page(page);
+		}
+	}
+
+	dprintk("%s found %zu ranges\n", __func__, count);
+	return 0;
+}
+
+void
+ext_tree_mark_committed(struct nfs4_layoutcommit_args *arg, int status)
+{
+	struct pnfs_block_layout *bl = BLK_LO2EXT(NFS_I(arg->inode)->layout);
+	struct rb_root *root = &bl->bl_ext_rw;
+	struct pnfs_block_extent *be;
+
+	dprintk("%s status %d\n", __func__, status);
+
+	ext_tree_free_commitdata(arg, arg->layoutupdate_len);
+
+	spin_lock(&bl->bl_ext_lock);
+	for (be = ext_tree_first(root); be; be = ext_tree_next(be)) {
+		if (be->be_state != PNFS_BLOCK_INVALID_DATA ||
+		    be->be_tag != EXTENT_COMMITTING)
+			continue;
+
+		if (status) {
+			/*
+			 * Mark as written and try again.
+			 *
+			 * XXX: some real error handling here wouldn't hurt..
+			 */
+			be->be_tag = EXTENT_WRITTEN;
+		} else {
+			be->be_state = PNFS_BLOCK_READWRITE_DATA;
+			be->be_tag = 0;
+		}
+
+		be = ext_try_to_merge_left(root, be);
+		be = ext_try_to_merge_right(root, be);
+	}
+	spin_unlock(&bl->bl_ext_lock);
+}
diff --git a/fs/nfs/blocklayout/rpc_pipefs.c b/fs/nfs/blocklayout/rpc_pipefs.c
new file mode 100644
index 000000000..ef9db135c
--- /dev/null
+++ b/fs/nfs/blocklayout/rpc_pipefs.c
@@ -0,0 +1,288 @@
+/*
+ *  Copyright (c) 2006,2007 The Regents of the University of Michigan.
+ *  All rights reserved.
+ *
+ *  Andy Adamson <andros@citi.umich.edu>
+ *  Fred Isaman <iisaman@umich.edu>
+ *
+ * permission is granted to use, copy, create derivative works and
+ * redistribute this software and such derivative works for any purpose,
+ * so long as the name of the university of michigan is not used in
+ * any advertising or publicity pertaining to the use or distribution
+ * of this software without specific, written prior authorization.  if
+ * the above copyright notice or any other identification of the
+ * university of michigan is included in any copy of any portion of
+ * this software, then the disclaimer below must also be included.
+ *
+ * this software is provided as is, without representation from the
+ * university of michigan as to its fitness for any purpose, and without
+ * warranty by the university of michigan of any kind, either express
+ * or implied, including without limitation the implied warranties of
+ * merchantability and fitness for a particular purpose.  the regents
+ * of the university of michigan shall not be liable for any damages,
+ * including special, indirect, incidental, or consequential damages,
+ * with respect to any claim arising out or in connection with the use
+ * of the software, even if it has been or is hereafter advised of the
+ * possibility of such damages.
+ */
+
+#include <linux/module.h>
+#include <linux/genhd.h>
+#include <linux/blkdev.h>
+
+#include "blocklayout.h"
+
+#define NFSDBG_FACILITY         NFSDBG_PNFS_LD
+
+static void
+nfs4_encode_simple(__be32 *p, struct pnfs_block_volume *b)
+{
+	int i;
+
+	*p++ = cpu_to_be32(1);
+	*p++ = cpu_to_be32(b->type);
+	*p++ = cpu_to_be32(b->simple.nr_sigs);
+	for (i = 0; i < b->simple.nr_sigs; i++) {
+		p = xdr_encode_hyper(p, b->simple.sigs[i].offset);
+		p = xdr_encode_opaque(p, b->simple.sigs[i].sig,
+					 b->simple.sigs[i].sig_len);
+	}
+}
+
+dev_t
+bl_resolve_deviceid(struct nfs_server *server, struct pnfs_block_volume *b,
+		gfp_t gfp_mask)
+{
+	struct net *net = server->nfs_client->cl_net;
+	struct nfs_net *nn = net_generic(net, nfs_net_id);
+	struct bl_dev_msg *reply = &nn->bl_mount_reply;
+	struct bl_pipe_msg bl_pipe_msg;
+	struct rpc_pipe_msg *msg = &bl_pipe_msg.msg;
+	struct bl_msg_hdr *bl_msg;
+	DECLARE_WAITQUEUE(wq, current);
+	dev_t dev = 0;
+	int rc;
+
+	dprintk("%s CREATING PIPEFS MESSAGE\n", __func__);
+
+	mutex_lock(&nn->bl_mutex);
+	bl_pipe_msg.bl_wq = &nn->bl_wq;
+
+	b->simple.len += 4;	/* single volume */
+	if (b->simple.len > PAGE_SIZE)
+		goto out_unlock;
+
+	memset(msg, 0, sizeof(*msg));
+	msg->len = sizeof(*bl_msg) + b->simple.len;
+	msg->data = kzalloc(msg->len, gfp_mask);
+	if (!msg->data)
+		goto out_free_data;
+
+	bl_msg = msg->data;
+	bl_msg->type = BL_DEVICE_MOUNT;
+	bl_msg->totallen = b->simple.len;
+	nfs4_encode_simple(msg->data + sizeof(*bl_msg), b);
+
+	dprintk("%s CALLING USERSPACE DAEMON\n", __func__);
+	add_wait_queue(&nn->bl_wq, &wq);
+	rc = rpc_queue_upcall(nn->bl_device_pipe, msg);
+	if (rc < 0) {
+		remove_wait_queue(&nn->bl_wq, &wq);
+		goto out_free_data;
+	}
+
+	set_current_state(TASK_UNINTERRUPTIBLE);
+	schedule();
+	remove_wait_queue(&nn->bl_wq, &wq);
+
+	if (reply->status != BL_DEVICE_REQUEST_PROC) {
+		printk(KERN_WARNING "%s failed to decode device: %d\n",
+			__func__, reply->status);
+		goto out_free_data;
+	}
+
+	dev = MKDEV(reply->major, reply->minor);
+out_free_data:
+	kfree(msg->data);
+out_unlock:
+	mutex_unlock(&nn->bl_mutex);
+	return dev;
+}
+
+static ssize_t bl_pipe_downcall(struct file *filp, const char __user *src,
+			 size_t mlen)
+{
+	struct nfs_net *nn = net_generic(file_inode(filp)->i_sb->s_fs_info,
+					 nfs_net_id);
+
+	if (mlen != sizeof (struct bl_dev_msg))
+		return -EINVAL;
+
+	if (copy_from_user(&nn->bl_mount_reply, src, mlen) != 0)
+		return -EFAULT;
+
+	wake_up(&nn->bl_wq);
+
+	return mlen;
+}
+
+static void bl_pipe_destroy_msg(struct rpc_pipe_msg *msg)
+{
+	struct bl_pipe_msg *bl_pipe_msg =
+		container_of(msg, struct bl_pipe_msg, msg);
+
+	if (msg->errno >= 0)
+		return;
+	wake_up(bl_pipe_msg->bl_wq);
+}
+
+static const struct rpc_pipe_ops bl_upcall_ops = {
+	.upcall		= rpc_pipe_generic_upcall,
+	.downcall	= bl_pipe_downcall,
+	.destroy_msg	= bl_pipe_destroy_msg,
+};
+
+static struct dentry *nfs4blocklayout_register_sb(struct super_block *sb,
+					    struct rpc_pipe *pipe)
+{
+	struct dentry *dir, *dentry;
+
+	dir = rpc_d_lookup_sb(sb, NFS_PIPE_DIRNAME);
+	if (dir == NULL)
+		return ERR_PTR(-ENOENT);
+	dentry = rpc_mkpipe_dentry(dir, "blocklayout", NULL, pipe);
+	dput(dir);
+	return dentry;
+}
+
+static void nfs4blocklayout_unregister_sb(struct super_block *sb,
+					  struct rpc_pipe *pipe)
+{
+	if (pipe->dentry)
+		rpc_unlink(pipe->dentry);
+}
+
+static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event,
+			   void *ptr)
+{
+	struct super_block *sb = ptr;
+	struct net *net = sb->s_fs_info;
+	struct nfs_net *nn = net_generic(net, nfs_net_id);
+	struct dentry *dentry;
+	int ret = 0;
+
+	if (!try_module_get(THIS_MODULE))
+		return 0;
+
+	if (nn->bl_device_pipe == NULL) {
+		module_put(THIS_MODULE);
+		return 0;
+	}
+
+	switch (event) {
+	case RPC_PIPEFS_MOUNT:
+		dentry = nfs4blocklayout_register_sb(sb, nn->bl_device_pipe);
+		if (IS_ERR(dentry)) {
+			ret = PTR_ERR(dentry);
+			break;
+		}
+		nn->bl_device_pipe->dentry = dentry;
+		break;
+	case RPC_PIPEFS_UMOUNT:
+		if (nn->bl_device_pipe->dentry)
+			nfs4blocklayout_unregister_sb(sb, nn->bl_device_pipe);
+		break;
+	default:
+		ret = -ENOTSUPP;
+		break;
+	}
+	module_put(THIS_MODULE);
+	return ret;
+}
+
+static struct notifier_block nfs4blocklayout_block = {
+	.notifier_call = rpc_pipefs_event,
+};
+
+static struct dentry *nfs4blocklayout_register_net(struct net *net,
+						   struct rpc_pipe *pipe)
+{
+	struct super_block *pipefs_sb;
+	struct dentry *dentry;
+
+	pipefs_sb = rpc_get_sb_net(net);
+	if (!pipefs_sb)
+		return NULL;
+	dentry = nfs4blocklayout_register_sb(pipefs_sb, pipe);
+	rpc_put_sb_net(net);
+	return dentry;
+}
+
+static void nfs4blocklayout_unregister_net(struct net *net,
+					   struct rpc_pipe *pipe)
+{
+	struct super_block *pipefs_sb;
+
+	pipefs_sb = rpc_get_sb_net(net);
+	if (pipefs_sb) {
+		nfs4blocklayout_unregister_sb(pipefs_sb, pipe);
+		rpc_put_sb_net(net);
+	}
+}
+
+static int nfs4blocklayout_net_init(struct net *net)
+{
+	struct nfs_net *nn = net_generic(net, nfs_net_id);
+	struct dentry *dentry;
+
+	mutex_init(&nn->bl_mutex);
+	init_waitqueue_head(&nn->bl_wq);
+	nn->bl_device_pipe = rpc_mkpipe_data(&bl_upcall_ops, 0);
+	if (IS_ERR(nn->bl_device_pipe))
+		return PTR_ERR(nn->bl_device_pipe);
+	dentry = nfs4blocklayout_register_net(net, nn->bl_device_pipe);
+	if (IS_ERR(dentry)) {
+		rpc_destroy_pipe_data(nn->bl_device_pipe);
+		return PTR_ERR(dentry);
+	}
+	nn->bl_device_pipe->dentry = dentry;
+	return 0;
+}
+
+static void nfs4blocklayout_net_exit(struct net *net)
+{
+	struct nfs_net *nn = net_generic(net, nfs_net_id);
+
+	nfs4blocklayout_unregister_net(net, nn->bl_device_pipe);
+	rpc_destroy_pipe_data(nn->bl_device_pipe);
+	nn->bl_device_pipe = NULL;
+}
+
+static struct pernet_operations nfs4blocklayout_net_ops = {
+	.init = nfs4blocklayout_net_init,
+	.exit = nfs4blocklayout_net_exit,
+};
+
+int __init bl_init_pipefs(void)
+{
+	int ret;
+
+	ret = rpc_pipefs_notifier_register(&nfs4blocklayout_block);
+	if (ret)
+		goto out;
+	ret = register_pernet_subsys(&nfs4blocklayout_net_ops);
+	if (ret)
+		goto out_unregister_notifier;
+	return 0;
+
+out_unregister_notifier:
+	rpc_pipefs_notifier_unregister(&nfs4blocklayout_block);
+out:
+	return ret;
+}
+
+void bl_cleanup_pipefs(void)
+{
+	rpc_pipefs_notifier_unregister(&nfs4blocklayout_block);
+	unregister_pernet_subsys(&nfs4blocklayout_net_ops);
+}
diff --git a/fs/nfs/cache_lib.c b/fs/nfs/cache_lib.c
new file mode 100644
index 000000000..ef6729568
--- /dev/null
+++ b/fs/nfs/cache_lib.c
@@ -0,0 +1,158 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/nfs/cache_lib.c
+ *
+ * Helper routines for the NFS client caches
+ *
+ * Copyright (c) 2009 Trond Myklebust <Trond.Myklebust@netapp.com>
+ */
+#include <linux/kmod.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/mount.h>
+#include <linux/namei.h>
+#include <linux/slab.h>
+#include <linux/sunrpc/cache.h>
+#include <linux/sunrpc/rpc_pipe_fs.h>
+#include <net/net_namespace.h>
+
+#include "cache_lib.h"
+
+#define NFS_CACHE_UPCALL_PATHLEN 256
+#define NFS_CACHE_UPCALL_TIMEOUT 15
+
+static char nfs_cache_getent_prog[NFS_CACHE_UPCALL_PATHLEN] =
+				"/sbin/nfs_cache_getent";
+static unsigned long nfs_cache_getent_timeout = NFS_CACHE_UPCALL_TIMEOUT;
+
+module_param_string(cache_getent, nfs_cache_getent_prog,
+		sizeof(nfs_cache_getent_prog), 0600);
+MODULE_PARM_DESC(cache_getent, "Path to the client cache upcall program");
+module_param_named(cache_getent_timeout, nfs_cache_getent_timeout, ulong, 0600);
+MODULE_PARM_DESC(cache_getent_timeout, "Timeout (in seconds) after which "
+		"the cache upcall is assumed to have failed");
+
+int nfs_cache_upcall(struct cache_detail *cd, char *entry_name)
+{
+	static char *envp[] = { "HOME=/",
+		"TERM=linux",
+		"PATH=/sbin:/usr/sbin:/bin:/usr/bin",
+		NULL
+	};
+	char *argv[] = {
+		nfs_cache_getent_prog,
+		cd->name,
+		entry_name,
+		NULL
+	};
+	int ret = -EACCES;
+
+	if (nfs_cache_getent_prog[0] == '\0')
+		goto out;
+	ret = call_usermodehelper(argv[0], argv, envp, UMH_WAIT_EXEC);
+	/*
+	 * Disable the upcall mechanism if we're getting an ENOENT or
+	 * EACCES error. The admin can re-enable it on the fly by using
+	 * sysfs to set the 'cache_getent' parameter once the problem
+	 * has been fixed.
+	 */
+	if (ret == -ENOENT || ret == -EACCES)
+		nfs_cache_getent_prog[0] = '\0';
+out:
+	return ret > 0 ? 0 : ret;
+}
+
+/*
+ * Deferred request handling
+ */
+void nfs_cache_defer_req_put(struct nfs_cache_defer_req *dreq)
+{
+	if (refcount_dec_and_test(&dreq->count))
+		kfree(dreq);
+}
+
+static void nfs_dns_cache_revisit(struct cache_deferred_req *d, int toomany)
+{
+	struct nfs_cache_defer_req *dreq;
+
+	dreq = container_of(d, struct nfs_cache_defer_req, deferred_req);
+
+	complete(&dreq->completion);
+	nfs_cache_defer_req_put(dreq);
+}
+
+static struct cache_deferred_req *nfs_dns_cache_defer(struct cache_req *req)
+{
+	struct nfs_cache_defer_req *dreq;
+
+	dreq = container_of(req, struct nfs_cache_defer_req, req);
+	dreq->deferred_req.revisit = nfs_dns_cache_revisit;
+	refcount_inc(&dreq->count);
+
+	return &dreq->deferred_req;
+}
+
+struct nfs_cache_defer_req *nfs_cache_defer_req_alloc(void)
+{
+	struct nfs_cache_defer_req *dreq;
+
+	dreq = kzalloc(sizeof(*dreq), GFP_KERNEL);
+	if (dreq) {
+		init_completion(&dreq->completion);
+		refcount_set(&dreq->count, 1);
+		dreq->req.defer = nfs_dns_cache_defer;
+	}
+	return dreq;
+}
+
+int nfs_cache_wait_for_upcall(struct nfs_cache_defer_req *dreq)
+{
+	if (wait_for_completion_timeout(&dreq->completion,
+			nfs_cache_getent_timeout * HZ) == 0)
+		return -ETIMEDOUT;
+	return 0;
+}
+
+int nfs_cache_register_sb(struct super_block *sb, struct cache_detail *cd)
+{
+	int ret;
+	struct dentry *dir;
+
+	dir = rpc_d_lookup_sb(sb, "cache");
+	ret = sunrpc_cache_register_pipefs(dir, cd->name, 0600, cd);
+	dput(dir);
+	return ret;
+}
+
+int nfs_cache_register_net(struct net *net, struct cache_detail *cd)
+{
+	struct super_block *pipefs_sb;
+	int ret = 0;
+
+	sunrpc_init_cache_detail(cd);
+	pipefs_sb = rpc_get_sb_net(net);
+	if (pipefs_sb) {
+		ret = nfs_cache_register_sb(pipefs_sb, cd);
+		rpc_put_sb_net(net);
+		if (ret)
+			sunrpc_destroy_cache_detail(cd);
+	}
+	return ret;
+}
+
+void nfs_cache_unregister_sb(struct super_block *sb, struct cache_detail *cd)
+{
+	sunrpc_cache_unregister_pipefs(cd);
+}
+
+void nfs_cache_unregister_net(struct net *net, struct cache_detail *cd)
+{
+	struct super_block *pipefs_sb;
+
+	pipefs_sb = rpc_get_sb_net(net);
+	if (pipefs_sb) {
+		nfs_cache_unregister_sb(pipefs_sb, cd);
+		rpc_put_sb_net(net);
+	}
+	sunrpc_destroy_cache_detail(cd);
+}
diff --git a/fs/nfs/cache_lib.h b/fs/nfs/cache_lib.h
new file mode 100644
index 000000000..220ee409a
--- /dev/null
+++ b/fs/nfs/cache_lib.h
@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Helper routines for the NFS client caches
+ *
+ * Copyright (c) 2009 Trond Myklebust <Trond.Myklebust@netapp.com>
+ */
+
+#include <linux/completion.h>
+#include <linux/sunrpc/cache.h>
+#include <linux/atomic.h>
+
+/*
+ * Deferred request handling
+ */
+struct nfs_cache_defer_req {
+	struct cache_req req;
+	struct cache_deferred_req deferred_req;
+	struct completion completion;
+	refcount_t count;
+};
+
+extern int nfs_cache_upcall(struct cache_detail *cd, char *entry_name);
+extern struct nfs_cache_defer_req *nfs_cache_defer_req_alloc(void);
+extern void nfs_cache_defer_req_put(struct nfs_cache_defer_req *dreq);
+extern int nfs_cache_wait_for_upcall(struct nfs_cache_defer_req *dreq);
+
+extern int nfs_cache_register_net(struct net *net, struct cache_detail *cd);
+extern void nfs_cache_unregister_net(struct net *net, struct cache_detail *cd);
+extern int nfs_cache_register_sb(struct super_block *sb,
+				 struct cache_detail *cd);
+extern void nfs_cache_unregister_sb(struct super_block *sb,
+				    struct cache_detail *cd);
diff --git a/fs/nfs/callback.c b/fs/nfs/callback.c
new file mode 100644
index 000000000..7817ad94a
--- /dev/null
+++ b/fs/nfs/callback.c
@@ -0,0 +1,465 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/nfs/callback.c
+ *
+ * Copyright (C) 2004 Trond Myklebust
+ *
+ * NFSv4 callback handling
+ */
+
+#include <linux/completion.h>
+#include <linux/ip.h>
+#include <linux/module.h>
+#include <linux/sched/signal.h>
+#include <linux/sunrpc/svc.h>
+#include <linux/sunrpc/svcsock.h>
+#include <linux/nfs_fs.h>
+#include <linux/errno.h>
+#include <linux/mutex.h>
+#include <linux/freezer.h>
+#include <linux/kthread.h>
+#include <linux/sunrpc/svcauth_gss.h>
+#include <linux/sunrpc/bc_xprt.h>
+
+#include <net/inet_sock.h>
+
+#include "nfs4_fs.h"
+#include "callback.h"
+#include "internal.h"
+#include "netns.h"
+
+#define NFSDBG_FACILITY NFSDBG_CALLBACK
+
+struct nfs_callback_data {
+	unsigned int users;
+	struct svc_serv *serv;
+};
+
+static struct nfs_callback_data nfs_callback_info[NFS4_MAX_MINOR_VERSION + 1];
+static DEFINE_MUTEX(nfs_callback_mutex);
+static struct svc_program nfs4_callback_program;
+
+static int nfs4_callback_up_net(struct svc_serv *serv, struct net *net)
+{
+	const struct cred *cred = current_cred();
+	int ret;
+	struct nfs_net *nn = net_generic(net, nfs_net_id);
+
+	ret = svc_create_xprt(serv, "tcp", net, PF_INET,
+				nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS,
+				cred);
+	if (ret <= 0)
+		goto out_err;
+	nn->nfs_callback_tcpport = ret;
+	dprintk("NFS: Callback listener port = %u (af %u, net %x)\n",
+		nn->nfs_callback_tcpport, PF_INET, net->ns.inum);
+
+	ret = svc_create_xprt(serv, "tcp", net, PF_INET6,
+				nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS,
+				cred);
+	if (ret > 0) {
+		nn->nfs_callback_tcpport6 = ret;
+		dprintk("NFS: Callback listener port = %u (af %u, net %x)\n",
+			nn->nfs_callback_tcpport6, PF_INET6, net->ns.inum);
+	} else if (ret != -EAFNOSUPPORT)
+		goto out_err;
+	return 0;
+
+out_err:
+	return (ret) ? ret : -ENOMEM;
+}
+
+/*
+ * This is the NFSv4 callback kernel thread.
+ */
+static int
+nfs4_callback_svc(void *vrqstp)
+{
+	int err;
+	struct svc_rqst *rqstp = vrqstp;
+
+	set_freezable();
+
+	while (!kthread_freezable_should_stop(NULL)) {
+
+		if (signal_pending(current))
+			flush_signals(current);
+		/*
+		 * Listen for a request on the socket
+		 */
+		err = svc_recv(rqstp, MAX_SCHEDULE_TIMEOUT);
+		if (err == -EAGAIN || err == -EINTR)
+			continue;
+		svc_process(rqstp);
+	}
+	svc_exit_thread(rqstp);
+	module_put_and_exit(0);
+	return 0;
+}
+
+#if defined(CONFIG_NFS_V4_1)
+/*
+ * The callback service for NFSv4.1 callbacks
+ */
+static int
+nfs41_callback_svc(void *vrqstp)
+{
+	struct svc_rqst *rqstp = vrqstp;
+	struct svc_serv *serv = rqstp->rq_server;
+	struct rpc_rqst *req;
+	int error;
+	DEFINE_WAIT(wq);
+
+	set_freezable();
+
+	while (!kthread_freezable_should_stop(NULL)) {
+
+		if (signal_pending(current))
+			flush_signals(current);
+
+		prepare_to_wait(&serv->sv_cb_waitq, &wq, TASK_INTERRUPTIBLE);
+		spin_lock_bh(&serv->sv_cb_lock);
+		if (!list_empty(&serv->sv_cb_list)) {
+			req = list_first_entry(&serv->sv_cb_list,
+					struct rpc_rqst, rq_bc_list);
+			list_del(&req->rq_bc_list);
+			spin_unlock_bh(&serv->sv_cb_lock);
+			finish_wait(&serv->sv_cb_waitq, &wq);
+			dprintk("Invoking bc_svc_process()\n");
+			error = bc_svc_process(serv, req, rqstp);
+			dprintk("bc_svc_process() returned w/ error code= %d\n",
+				error);
+		} else {
+			spin_unlock_bh(&serv->sv_cb_lock);
+			if (!kthread_should_stop())
+				schedule();
+			finish_wait(&serv->sv_cb_waitq, &wq);
+		}
+	}
+	svc_exit_thread(rqstp);
+	module_put_and_exit(0);
+	return 0;
+}
+
+static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
+		struct svc_serv *serv)
+{
+	if (minorversion)
+		/*
+		 * Save the svc_serv in the transport so that it can
+		 * be referenced when the session backchannel is initialized
+		 */
+		xprt->bc_serv = serv;
+}
+#else
+static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
+		struct svc_serv *serv)
+{
+}
+#endif /* CONFIG_NFS_V4_1 */
+
+static int nfs_callback_start_svc(int minorversion, struct rpc_xprt *xprt,
+				  struct svc_serv *serv)
+{
+	int nrservs = nfs_callback_nr_threads;
+	int ret;
+
+	nfs_callback_bc_serv(minorversion, xprt, serv);
+
+	if (nrservs < NFS4_MIN_NR_CALLBACK_THREADS)
+		nrservs = NFS4_MIN_NR_CALLBACK_THREADS;
+
+	if (serv->sv_nrthreads-1 == nrservs)
+		return 0;
+
+	ret = serv->sv_ops->svo_setup(serv, NULL, nrservs);
+	if (ret) {
+		serv->sv_ops->svo_setup(serv, NULL, 0);
+		return ret;
+	}
+	dprintk("nfs_callback_up: service started\n");
+	return 0;
+}
+
+static void nfs_callback_down_net(u32 minorversion, struct svc_serv *serv, struct net *net)
+{
+	struct nfs_net *nn = net_generic(net, nfs_net_id);
+
+	if (--nn->cb_users[minorversion])
+		return;
+
+	dprintk("NFS: destroy per-net callback data; net=%x\n", net->ns.inum);
+	svc_shutdown_net(serv, net);
+}
+
+static int nfs_callback_up_net(int minorversion, struct svc_serv *serv,
+			       struct net *net, struct rpc_xprt *xprt)
+{
+	struct nfs_net *nn = net_generic(net, nfs_net_id);
+	int ret;
+
+	if (nn->cb_users[minorversion]++)
+		return 0;
+
+	dprintk("NFS: create per-net callback data; net=%x\n", net->ns.inum);
+
+	ret = svc_bind(serv, net);
+	if (ret < 0) {
+		printk(KERN_WARNING "NFS: bind callback service failed\n");
+		goto err_bind;
+	}
+
+	ret = 0;
+	if (!IS_ENABLED(CONFIG_NFS_V4_1) || minorversion == 0)
+		ret = nfs4_callback_up_net(serv, net);
+	else if (xprt->ops->bc_setup)
+		set_bc_enabled(serv);
+	else
+		ret = -EPROTONOSUPPORT;
+
+	if (ret < 0) {
+		printk(KERN_ERR "NFS: callback service start failed\n");
+		goto err_socks;
+	}
+	return 0;
+
+err_socks:
+	svc_rpcb_cleanup(serv, net);
+err_bind:
+	nn->cb_users[minorversion]--;
+	dprintk("NFS: Couldn't create callback socket: err = %d; "
+			"net = %x\n", ret, net->ns.inum);
+	return ret;
+}
+
+static const struct svc_serv_ops nfs40_cb_sv_ops = {
+	.svo_function		= nfs4_callback_svc,
+	.svo_enqueue_xprt	= svc_xprt_do_enqueue,
+	.svo_setup		= svc_set_num_threads_sync,
+	.svo_module		= THIS_MODULE,
+};
+#if defined(CONFIG_NFS_V4_1)
+static const struct svc_serv_ops nfs41_cb_sv_ops = {
+	.svo_function		= nfs41_callback_svc,
+	.svo_enqueue_xprt	= svc_xprt_do_enqueue,
+	.svo_setup		= svc_set_num_threads_sync,
+	.svo_module		= THIS_MODULE,
+};
+
+static const struct svc_serv_ops *nfs4_cb_sv_ops[] = {
+	[0] = &nfs40_cb_sv_ops,
+	[1] = &nfs41_cb_sv_ops,
+};
+#else
+static const struct svc_serv_ops *nfs4_cb_sv_ops[] = {
+	[0] = &nfs40_cb_sv_ops,
+	[1] = NULL,
+};
+#endif
+
+static struct svc_serv *nfs_callback_create_svc(int minorversion)
+{
+	struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
+	const struct svc_serv_ops *sv_ops;
+	struct svc_serv *serv;
+
+	/*
+	 * Check whether we're already up and running.
+	 */
+	if (cb_info->serv) {
+		/*
+		 * Note: increase service usage, because later in case of error
+		 * svc_destroy() will be called.
+		 */
+		svc_get(cb_info->serv);
+		return cb_info->serv;
+	}
+
+	switch (minorversion) {
+	case 0:
+		sv_ops = nfs4_cb_sv_ops[0];
+		break;
+	default:
+		sv_ops = nfs4_cb_sv_ops[1];
+	}
+
+	if (sv_ops == NULL)
+		return ERR_PTR(-ENOTSUPP);
+
+	/*
+	 * Sanity check: if there's no task,
+	 * we should be the first user ...
+	 */
+	if (cb_info->users)
+		printk(KERN_WARNING "nfs_callback_create_svc: no kthread, %d users??\n",
+			cb_info->users);
+
+	serv = svc_create_pooled(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE, sv_ops);
+	if (!serv) {
+		printk(KERN_ERR "nfs_callback_create_svc: create service failed\n");
+		return ERR_PTR(-ENOMEM);
+	}
+	cb_info->serv = serv;
+	/* As there is only one thread we need to over-ride the
+	 * default maximum of 80 connections
+	 */
+	serv->sv_maxconn = 1024;
+	dprintk("nfs_callback_create_svc: service created\n");
+	return serv;
+}
+
+/*
+ * Bring up the callback thread if it is not already up.
+ */
+int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt)
+{
+	struct svc_serv *serv;
+	struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
+	int ret;
+	struct net *net = xprt->xprt_net;
+
+	mutex_lock(&nfs_callback_mutex);
+
+	serv = nfs_callback_create_svc(minorversion);
+	if (IS_ERR(serv)) {
+		ret = PTR_ERR(serv);
+		goto err_create;
+	}
+
+	ret = nfs_callback_up_net(minorversion, serv, net, xprt);
+	if (ret < 0)
+		goto err_net;
+
+	ret = nfs_callback_start_svc(minorversion, xprt, serv);
+	if (ret < 0)
+		goto err_start;
+
+	cb_info->users++;
+	/*
+	 * svc_create creates the svc_serv with sv_nrthreads == 1, and then
+	 * svc_prepare_thread increments that. So we need to call svc_destroy
+	 * on both success and failure so that the refcount is 1 when the
+	 * thread exits.
+	 */
+err_net:
+	if (!cb_info->users)
+		cb_info->serv = NULL;
+	svc_destroy(serv);
+err_create:
+	mutex_unlock(&nfs_callback_mutex);
+	return ret;
+
+err_start:
+	nfs_callback_down_net(minorversion, serv, net);
+	dprintk("NFS: Couldn't create server thread; err = %d\n", ret);
+	goto err_net;
+}
+
+/*
+ * Kill the callback thread if it's no longer being used.
+ */
+void nfs_callback_down(int minorversion, struct net *net)
+{
+	struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
+	struct svc_serv *serv;
+
+	mutex_lock(&nfs_callback_mutex);
+	serv = cb_info->serv;
+	nfs_callback_down_net(minorversion, serv, net);
+	cb_info->users--;
+	if (cb_info->users == 0) {
+		svc_get(serv);
+		serv->sv_ops->svo_setup(serv, NULL, 0);
+		svc_destroy(serv);
+		dprintk("nfs_callback_down: service destroyed\n");
+		cb_info->serv = NULL;
+	}
+	mutex_unlock(&nfs_callback_mutex);
+}
+
+/* Boolean check of RPC_AUTH_GSS principal */
+int
+check_gss_callback_principal(struct nfs_client *clp, struct svc_rqst *rqstp)
+{
+	char *p = rqstp->rq_cred.cr_principal;
+
+	if (rqstp->rq_authop->flavour != RPC_AUTH_GSS)
+		return 1;
+
+	/* No RPC_AUTH_GSS on NFSv4.1 back channel yet */
+	if (clp->cl_minorversion != 0)
+		return 0;
+	/*
+	 * It might just be a normal user principal, in which case
+	 * userspace won't bother to tell us the name at all.
+	 */
+	if (p == NULL)
+		return 0;
+
+	/*
+	 * Did we get the acceptor from userland during the SETCLIENID
+	 * negotiation?
+	 */
+	if (clp->cl_acceptor)
+		return !strcmp(p, clp->cl_acceptor);
+
+	/*
+	 * Otherwise try to verify it using the cl_hostname. Note that this
+	 * doesn't work if a non-canonical hostname was used in the devname.
+	 */
+
+	/* Expect a GSS_C_NT_HOSTBASED_NAME like "nfs@serverhostname" */
+
+	if (memcmp(p, "nfs@", 4) != 0)
+		return 0;
+	p += 4;
+	if (strcmp(p, clp->cl_hostname) != 0)
+		return 0;
+	return 1;
+}
+
+/*
+ * pg_authenticate method for nfsv4 callback threads.
+ *
+ * The authflavor has been negotiated, so an incorrect flavor is a server
+ * bug. Deny packets with incorrect authflavor.
+ *
+ * All other checking done after NFS decoding where the nfs_client can be
+ * found in nfs4_callback_compound
+ */
+static int nfs_callback_authenticate(struct svc_rqst *rqstp)
+{
+	switch (rqstp->rq_authop->flavour) {
+	case RPC_AUTH_NULL:
+		if (rqstp->rq_proc != CB_NULL)
+			return SVC_DENIED;
+		break;
+	case RPC_AUTH_GSS:
+		/* No RPC_AUTH_GSS support yet in NFSv4.1 */
+		 if (svc_is_backchannel(rqstp))
+			return SVC_DENIED;
+	}
+	return SVC_OK;
+}
+
+/*
+ * Define NFS4 callback program
+ */
+static const struct svc_version *nfs4_callback_version[] = {
+	[1] = &nfs4_callback_version1,
+	[4] = &nfs4_callback_version4,
+};
+
+static struct svc_stat nfs4_callback_stats;
+
+static struct svc_program nfs4_callback_program = {
+	.pg_prog = NFS4_CALLBACK,			/* RPC service number */
+	.pg_nvers = ARRAY_SIZE(nfs4_callback_version),	/* Number of entries */
+	.pg_vers = nfs4_callback_version,		/* version table */
+	.pg_name = "NFSv4 callback",			/* service name */
+	.pg_class = "nfs",				/* authentication class */
+	.pg_stats = &nfs4_callback_stats,
+	.pg_authenticate = nfs_callback_authenticate,
+	.pg_init_request = svc_generic_init_request,
+	.pg_rpcbind_set	= svc_generic_rpcbind_set,
+};
diff --git a/fs/nfs/callback.h b/fs/nfs/callback.h
new file mode 100644
index 000000000..ccd4f245c
--- /dev/null
+++ b/fs/nfs/callback.h
@@ -0,0 +1,223 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * linux/fs/nfs/callback.h
+ *
+ * Copyright (C) 2004 Trond Myklebust
+ *
+ * NFSv4 callback definitions
+ */
+#ifndef __LINUX_FS_NFS_CALLBACK_H
+#define __LINUX_FS_NFS_CALLBACK_H
+#include <linux/sunrpc/svc.h>
+
+#define NFS4_CALLBACK 0x40000000
+#define NFS4_CALLBACK_XDRSIZE 2048
+#define NFS4_CALLBACK_BUFSIZE (1024 + NFS4_CALLBACK_XDRSIZE)
+
+enum nfs4_callback_procnum {
+	CB_NULL = 0,
+	CB_COMPOUND = 1,
+};
+
+enum nfs4_callback_opnum {
+	OP_CB_GETATTR = 3,
+	OP_CB_RECALL  = 4,
+/* Callback operations new to NFSv4.1 */
+	OP_CB_LAYOUTRECALL  = 5,
+	OP_CB_NOTIFY        = 6,
+	OP_CB_PUSH_DELEG    = 7,
+	OP_CB_RECALL_ANY    = 8,
+	OP_CB_RECALLABLE_OBJ_AVAIL = 9,
+	OP_CB_RECALL_SLOT   = 10,
+	OP_CB_SEQUENCE      = 11,
+	OP_CB_WANTS_CANCELLED = 12,
+	OP_CB_NOTIFY_LOCK   = 13,
+	OP_CB_NOTIFY_DEVICEID = 14,
+/* Callback operations new to NFSv4.2 */
+	OP_CB_OFFLOAD = 15,
+	OP_CB_ILLEGAL = 10044,
+};
+
+struct nfs4_slot;
+struct cb_process_state {
+	__be32			drc_status;
+	struct nfs_client	*clp;
+	struct nfs4_slot	*slot;
+	u32			minorversion;
+	struct net		*net;
+};
+
+struct cb_compound_hdr_arg {
+	unsigned int taglen;
+	const char *tag;
+	unsigned int minorversion;
+	unsigned int cb_ident; /* v4.0 callback identifier */
+	unsigned nops;
+};
+
+struct cb_compound_hdr_res {
+	__be32 *status;
+	unsigned int taglen;
+	const char *tag;
+	__be32 *nops;
+};
+
+struct cb_getattrargs {
+	struct nfs_fh fh;
+	uint32_t bitmap[2];
+};
+
+struct cb_getattrres {
+	__be32 status;
+	uint32_t bitmap[2];
+	uint64_t size;
+	uint64_t change_attr;
+	struct timespec64 ctime;
+	struct timespec64 mtime;
+};
+
+struct cb_recallargs {
+	struct nfs_fh fh;
+	nfs4_stateid stateid;
+	uint32_t truncate;
+};
+
+#if defined(CONFIG_NFS_V4_1)
+
+struct referring_call {
+	uint32_t			rc_sequenceid;
+	uint32_t			rc_slotid;
+};
+
+struct referring_call_list {
+	struct nfs4_sessionid		rcl_sessionid;
+	uint32_t			rcl_nrefcalls;
+	struct referring_call 		*rcl_refcalls;
+};
+
+struct cb_sequenceargs {
+	struct sockaddr			*csa_addr;
+	struct nfs4_sessionid		csa_sessionid;
+	uint32_t			csa_sequenceid;
+	uint32_t			csa_slotid;
+	uint32_t			csa_highestslotid;
+	uint32_t			csa_cachethis;
+	uint32_t			csa_nrclists;
+	struct referring_call_list	*csa_rclists;
+};
+
+struct cb_sequenceres {
+	__be32				csr_status;
+	struct nfs4_sessionid		csr_sessionid;
+	uint32_t			csr_sequenceid;
+	uint32_t			csr_slotid;
+	uint32_t			csr_highestslotid;
+	uint32_t			csr_target_highestslotid;
+};
+
+extern __be32 nfs4_callback_sequence(void *argp, void *resp,
+				       struct cb_process_state *cps);
+
+#define RCA4_TYPE_MASK_RDATA_DLG	0
+#define RCA4_TYPE_MASK_WDATA_DLG	1
+#define RCA4_TYPE_MASK_DIR_DLG         2
+#define RCA4_TYPE_MASK_FILE_LAYOUT     3
+#define RCA4_TYPE_MASK_BLK_LAYOUT      4
+#define RCA4_TYPE_MASK_OBJ_LAYOUT_MIN  8
+#define RCA4_TYPE_MASK_OBJ_LAYOUT_MAX  9
+#define RCA4_TYPE_MASK_OTHER_LAYOUT_MIN 12
+#define RCA4_TYPE_MASK_OTHER_LAYOUT_MAX 15
+#define PNFS_FF_RCA4_TYPE_MASK_READ 16
+#define PNFS_FF_RCA4_TYPE_MASK_RW 17
+#define RCA4_TYPE_MASK_ALL 0x3f31f
+
+struct cb_recallanyargs {
+	uint32_t	craa_objs_to_keep;
+	uint32_t	craa_type_mask;
+};
+
+extern __be32 nfs4_callback_recallany(void *argp, void *resp,
+					struct cb_process_state *cps);
+
+struct cb_recallslotargs {
+	uint32_t	crsa_target_highest_slotid;
+};
+extern __be32 nfs4_callback_recallslot(void *argp, void *resp,
+					 struct cb_process_state *cps);
+
+struct cb_layoutrecallargs {
+	uint32_t		cbl_recall_type;
+	uint32_t		cbl_layout_type;
+	uint32_t		cbl_layoutchanged;
+	union {
+		struct {
+			struct nfs_fh		cbl_fh;
+			struct pnfs_layout_range cbl_range;
+			nfs4_stateid		cbl_stateid;
+		};
+		struct nfs_fsid		cbl_fsid;
+	};
+};
+
+extern __be32 nfs4_callback_layoutrecall(void *argp, void *resp,
+		struct cb_process_state *cps);
+
+struct cb_devicenotifyitem {
+	uint32_t		cbd_notify_type;
+	uint32_t		cbd_layout_type;
+	struct nfs4_deviceid	cbd_dev_id;
+	uint32_t		cbd_immediate;
+};
+
+struct cb_devicenotifyargs {
+	uint32_t			 ndevs;
+	struct cb_devicenotifyitem	 *devs;
+};
+
+extern __be32 nfs4_callback_devicenotify(void *argp, void *resp,
+		struct cb_process_state *cps);
+
+struct cb_notify_lock_args {
+	struct nfs_fh			cbnl_fh;
+	struct nfs_lowner		cbnl_owner;
+	bool				cbnl_valid;
+};
+
+extern __be32 nfs4_callback_notify_lock(void *argp, void *resp,
+					 struct cb_process_state *cps);
+#endif /* CONFIG_NFS_V4_1 */
+#ifdef CONFIG_NFS_V4_2
+struct cb_offloadargs {
+	struct nfs_fh		coa_fh;
+	nfs4_stateid		coa_stateid;
+	uint32_t		error;
+	uint64_t		wr_count;
+	struct nfs_writeverf	wr_writeverf;
+};
+
+extern __be32 nfs4_callback_offload(void *args, void *dummy,
+				    struct cb_process_state *cps);
+#endif /* CONFIG_NFS_V4_2 */
+extern int check_gss_callback_principal(struct nfs_client *, struct svc_rqst *);
+extern __be32 nfs4_callback_getattr(void *argp, void *resp,
+				    struct cb_process_state *cps);
+extern __be32 nfs4_callback_recall(void *argp, void *resp,
+				   struct cb_process_state *cps);
+#if IS_ENABLED(CONFIG_NFS_V4)
+extern int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt);
+extern void nfs_callback_down(int minorversion, struct net *net);
+#endif /* CONFIG_NFS_V4 */
+/*
+ * nfs41: Callbacks are expected to not cause substantial latency,
+ * so we limit their concurrency to 1 by setting up the maximum number
+ * of slots for the backchannel.
+ */
+#define NFS41_BC_MIN_CALLBACKS 1
+#define NFS41_BC_MAX_CALLBACKS 1
+
+#define NFS4_MIN_NR_CALLBACK_THREADS 1
+
+extern unsigned int nfs_callback_set_tcpport;
+extern unsigned short nfs_callback_nr_threads;
+
+#endif /* __LINUX_FS_NFS_CALLBACK_H */
diff --git a/fs/nfs/callback_proc.c b/fs/nfs/callback_proc.c
new file mode 100644
index 000000000..bfdd21224
--- /dev/null
+++ b/fs/nfs/callback_proc.c
@@ -0,0 +1,731 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/nfs/callback_proc.c
+ *
+ * Copyright (C) 2004 Trond Myklebust
+ *
+ * NFSv4 callback procedures
+ */
+#include <linux/nfs4.h>
+#include <linux/nfs_fs.h>
+#include <linux/slab.h>
+#include <linux/rcupdate.h>
+#include "nfs4_fs.h"
+#include "callback.h"
+#include "delegation.h"
+#include "internal.h"
+#include "pnfs.h"
+#include "nfs4session.h"
+#include "nfs4trace.h"
+
+#define NFSDBG_FACILITY NFSDBG_CALLBACK
+
+__be32 nfs4_callback_getattr(void *argp, void *resp,
+			     struct cb_process_state *cps)
+{
+	struct cb_getattrargs *args = argp;
+	struct cb_getattrres *res = resp;
+	struct nfs_delegation *delegation;
+	struct inode *inode;
+
+	res->status = htonl(NFS4ERR_OP_NOT_IN_SESSION);
+	if (!cps->clp) /* Always set for v4.0. Set in cb_sequence for v4.1 */
+		goto out;
+
+	res->bitmap[0] = res->bitmap[1] = 0;
+	res->status = htonl(NFS4ERR_BADHANDLE);
+
+	dprintk_rcu("NFS: GETATTR callback request from %s\n",
+		rpc_peeraddr2str(cps->clp->cl_rpcclient, RPC_DISPLAY_ADDR));
+
+	inode = nfs_delegation_find_inode(cps->clp, &args->fh);
+	if (IS_ERR(inode)) {
+		if (inode == ERR_PTR(-EAGAIN))
+			res->status = htonl(NFS4ERR_DELAY);
+		trace_nfs4_cb_getattr(cps->clp, &args->fh, NULL,
+				-ntohl(res->status));
+		goto out;
+	}
+	rcu_read_lock();
+	delegation = nfs4_get_valid_delegation(inode);
+	if (delegation == NULL || (delegation->type & FMODE_WRITE) == 0)
+		goto out_iput;
+	res->size = i_size_read(inode);
+	res->change_attr = delegation->change_attr;
+	if (nfs_have_writebacks(inode))
+		res->change_attr++;
+	res->ctime = inode->i_ctime;
+	res->mtime = inode->i_mtime;
+	res->bitmap[0] = (FATTR4_WORD0_CHANGE|FATTR4_WORD0_SIZE) &
+		args->bitmap[0];
+	res->bitmap[1] = (FATTR4_WORD1_TIME_METADATA|FATTR4_WORD1_TIME_MODIFY) &
+		args->bitmap[1];
+	res->status = 0;
+out_iput:
+	rcu_read_unlock();
+	trace_nfs4_cb_getattr(cps->clp, &args->fh, inode, -ntohl(res->status));
+	nfs_iput_and_deactive(inode);
+out:
+	dprintk("%s: exit with status = %d\n", __func__, ntohl(res->status));
+	return res->status;
+}
+
+__be32 nfs4_callback_recall(void *argp, void *resp,
+			    struct cb_process_state *cps)
+{
+	struct cb_recallargs *args = argp;
+	struct inode *inode;
+	__be32 res;
+	
+	res = htonl(NFS4ERR_OP_NOT_IN_SESSION);
+	if (!cps->clp) /* Always set for v4.0. Set in cb_sequence for v4.1 */
+		goto out;
+
+	dprintk_rcu("NFS: RECALL callback request from %s\n",
+		rpc_peeraddr2str(cps->clp->cl_rpcclient, RPC_DISPLAY_ADDR));
+
+	res = htonl(NFS4ERR_BADHANDLE);
+	inode = nfs_delegation_find_inode(cps->clp, &args->fh);
+	if (IS_ERR(inode)) {
+		if (inode == ERR_PTR(-EAGAIN))
+			res = htonl(NFS4ERR_DELAY);
+		trace_nfs4_cb_recall(cps->clp, &args->fh, NULL,
+				&args->stateid, -ntohl(res));
+		goto out;
+	}
+	/* Set up a helper thread to actually return the delegation */
+	switch (nfs_async_inode_return_delegation(inode, &args->stateid)) {
+	case 0:
+		res = 0;
+		break;
+	case -ENOENT:
+		res = htonl(NFS4ERR_BAD_STATEID);
+		break;
+	default:
+		res = htonl(NFS4ERR_RESOURCE);
+	}
+	trace_nfs4_cb_recall(cps->clp, &args->fh, inode,
+			&args->stateid, -ntohl(res));
+	nfs_iput_and_deactive(inode);
+out:
+	dprintk("%s: exit with status = %d\n", __func__, ntohl(res));
+	return res;
+}
+
+#if defined(CONFIG_NFS_V4_1)
+
+/*
+ * Lookup a layout inode by stateid
+ *
+ * Note: returns a refcount on the inode and superblock
+ */
+static struct inode *nfs_layout_find_inode_by_stateid(struct nfs_client *clp,
+		const nfs4_stateid *stateid)
+	__must_hold(RCU)
+{
+	struct nfs_server *server;
+	struct inode *inode;
+	struct pnfs_layout_hdr *lo;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
+		list_for_each_entry_rcu(lo, &server->layouts, plh_layouts) {
+			if (!pnfs_layout_is_valid(lo))
+				continue;
+			if (!nfs4_stateid_match_other(stateid, &lo->plh_stateid))
+				continue;
+			if (nfs_sb_active(server->super))
+				inode = igrab(lo->plh_inode);
+			else
+				inode = ERR_PTR(-EAGAIN);
+			rcu_read_unlock();
+			if (inode)
+				return inode;
+			nfs_sb_deactive(server->super);
+			return ERR_PTR(-EAGAIN);
+		}
+	}
+	rcu_read_unlock();
+	return ERR_PTR(-ENOENT);
+}
+
+/*
+ * Lookup a layout inode by filehandle.
+ *
+ * Note: returns a refcount on the inode and superblock
+ *
+ */
+static struct inode *nfs_layout_find_inode_by_fh(struct nfs_client *clp,
+		const struct nfs_fh *fh)
+{
+	struct nfs_server *server;
+	struct nfs_inode *nfsi;
+	struct inode *inode;
+	struct pnfs_layout_hdr *lo;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
+		list_for_each_entry_rcu(lo, &server->layouts, plh_layouts) {
+			nfsi = NFS_I(lo->plh_inode);
+			if (nfs_compare_fh(fh, &nfsi->fh))
+				continue;
+			if (nfsi->layout != lo)
+				continue;
+			if (nfs_sb_active(server->super))
+				inode = igrab(lo->plh_inode);
+			else
+				inode = ERR_PTR(-EAGAIN);
+			rcu_read_unlock();
+			if (inode)
+				return inode;
+			nfs_sb_deactive(server->super);
+			return ERR_PTR(-EAGAIN);
+		}
+	}
+	rcu_read_unlock();
+	return ERR_PTR(-ENOENT);
+}
+
+static struct inode *nfs_layout_find_inode(struct nfs_client *clp,
+		const struct nfs_fh *fh,
+		const nfs4_stateid *stateid)
+{
+	struct inode *inode;
+
+	inode = nfs_layout_find_inode_by_stateid(clp, stateid);
+	if (inode == ERR_PTR(-ENOENT))
+		inode = nfs_layout_find_inode_by_fh(clp, fh);
+	return inode;
+}
+
+/*
+ * Enforce RFC5661 section 12.5.5.2.1. (Layout Recall and Return Sequencing)
+ */
+static u32 pnfs_check_callback_stateid(struct pnfs_layout_hdr *lo,
+					const nfs4_stateid *new)
+{
+	u32 oldseq, newseq;
+
+	/* Is the stateid not initialised? */
+	if (!pnfs_layout_is_valid(lo))
+		return NFS4ERR_NOMATCHING_LAYOUT;
+
+	/* Mismatched stateid? */
+	if (!nfs4_stateid_match_other(&lo->plh_stateid, new))
+		return NFS4ERR_BAD_STATEID;
+
+	newseq = be32_to_cpu(new->seqid);
+	/* Are we already in a layout recall situation? */
+	if (test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags) &&
+	    lo->plh_return_seq != 0) {
+		if (newseq < lo->plh_return_seq)
+			return NFS4ERR_OLD_STATEID;
+		if (newseq > lo->plh_return_seq)
+			return NFS4ERR_DELAY;
+		goto out;
+	}
+
+	/* Check that the stateid matches what we think it should be. */
+	oldseq = be32_to_cpu(lo->plh_stateid.seqid);
+	if (newseq > oldseq + 1)
+		return NFS4ERR_DELAY;
+	/* Crazy server! */
+	if (newseq <= oldseq)
+		return NFS4ERR_OLD_STATEID;
+out:
+	return NFS_OK;
+}
+
+static u32 initiate_file_draining(struct nfs_client *clp,
+				  struct cb_layoutrecallargs *args)
+{
+	struct inode *ino;
+	struct pnfs_layout_hdr *lo;
+	u32 rv = NFS4ERR_NOMATCHING_LAYOUT;
+	LIST_HEAD(free_me_list);
+
+	ino = nfs_layout_find_inode(clp, &args->cbl_fh, &args->cbl_stateid);
+	if (IS_ERR(ino)) {
+		if (ino == ERR_PTR(-EAGAIN))
+			rv = NFS4ERR_DELAY;
+		goto out_noput;
+	}
+
+	pnfs_layoutcommit_inode(ino, false);
+
+
+	spin_lock(&ino->i_lock);
+	lo = NFS_I(ino)->layout;
+	if (!lo) {
+		spin_unlock(&ino->i_lock);
+		goto out;
+	}
+	pnfs_get_layout_hdr(lo);
+	rv = pnfs_check_callback_stateid(lo, &args->cbl_stateid);
+	if (rv != NFS_OK)
+		goto unlock;
+
+	/*
+	 * Enforce RFC5661 Section 12.5.5.2.1.5 (Bulk Recall and Return)
+	 */
+	if (test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags)) {
+		rv = NFS4ERR_DELAY;
+		goto unlock;
+	}
+
+	pnfs_set_layout_stateid(lo, &args->cbl_stateid, NULL, true);
+	switch (pnfs_mark_matching_lsegs_return(lo, &free_me_list,
+				&args->cbl_range,
+				be32_to_cpu(args->cbl_stateid.seqid))) {
+	case 0:
+	case -EBUSY:
+		/* There are layout segments that need to be returned */
+		rv = NFS4_OK;
+		break;
+	case -ENOENT:
+		set_bit(NFS_LAYOUT_DRAIN, &lo->plh_flags);
+		/* Embrace your forgetfulness! */
+		rv = NFS4ERR_NOMATCHING_LAYOUT;
+
+		if (NFS_SERVER(ino)->pnfs_curr_ld->return_range) {
+			NFS_SERVER(ino)->pnfs_curr_ld->return_range(lo,
+				&args->cbl_range);
+		}
+	}
+unlock:
+	spin_unlock(&ino->i_lock);
+	pnfs_free_lseg_list(&free_me_list);
+	/* Free all lsegs that are attached to commit buckets */
+	nfs_commit_inode(ino, 0);
+	pnfs_put_layout_hdr(lo);
+out:
+	nfs_iput_and_deactive(ino);
+out_noput:
+	trace_nfs4_cb_layoutrecall_file(clp, &args->cbl_fh, ino,
+			&args->cbl_stateid, -rv);
+	return rv;
+}
+
+static u32 initiate_bulk_draining(struct nfs_client *clp,
+				  struct cb_layoutrecallargs *args)
+{
+	int stat;
+
+	if (args->cbl_recall_type == RETURN_FSID)
+		stat = pnfs_destroy_layouts_byfsid(clp, &args->cbl_fsid, true);
+	else
+		stat = pnfs_destroy_layouts_byclid(clp, true);
+	if (stat != 0)
+		return NFS4ERR_DELAY;
+	return NFS4ERR_NOMATCHING_LAYOUT;
+}
+
+static u32 do_callback_layoutrecall(struct nfs_client *clp,
+				    struct cb_layoutrecallargs *args)
+{
+	if (args->cbl_recall_type == RETURN_FILE)
+		return initiate_file_draining(clp, args);
+	return initiate_bulk_draining(clp, args);
+}
+
+__be32 nfs4_callback_layoutrecall(void *argp, void *resp,
+				  struct cb_process_state *cps)
+{
+	struct cb_layoutrecallargs *args = argp;
+	u32 res = NFS4ERR_OP_NOT_IN_SESSION;
+
+	if (cps->clp)
+		res = do_callback_layoutrecall(cps->clp, args);
+	return cpu_to_be32(res);
+}
+
+static void pnfs_recall_all_layouts(struct nfs_client *clp)
+{
+	struct cb_layoutrecallargs args;
+
+	/* Pretend we got a CB_LAYOUTRECALL(ALL) */
+	memset(&args, 0, sizeof(args));
+	args.cbl_recall_type = RETURN_ALL;
+	/* FIXME we ignore errors, what should we do? */
+	do_callback_layoutrecall(clp, &args);
+}
+
+__be32 nfs4_callback_devicenotify(void *argp, void *resp,
+				  struct cb_process_state *cps)
+{
+	struct cb_devicenotifyargs *args = argp;
+	const struct pnfs_layoutdriver_type *ld = NULL;
+	uint32_t i;
+	__be32 res = 0;
+
+	if (!cps->clp) {
+		res = cpu_to_be32(NFS4ERR_OP_NOT_IN_SESSION);
+		goto out;
+	}
+
+	for (i = 0; i < args->ndevs; i++) {
+		struct cb_devicenotifyitem *dev = &args->devs[i];
+
+		if (!ld || ld->id != dev->cbd_layout_type) {
+			pnfs_put_layoutdriver(ld);
+			ld = pnfs_find_layoutdriver(dev->cbd_layout_type);
+			if (!ld)
+				continue;
+		}
+		nfs4_delete_deviceid(ld, cps->clp, &dev->cbd_dev_id);
+	}
+	pnfs_put_layoutdriver(ld);
+out:
+	kfree(args->devs);
+	return res;
+}
+
+/*
+ * Validate the sequenceID sent by the server.
+ * Return success if the sequenceID is one more than what we last saw on
+ * this slot, accounting for wraparound.  Increments the slot's sequence.
+ *
+ * We don't yet implement a duplicate request cache, instead we set the
+ * back channel ca_maxresponsesize_cached to zero. This is OK for now
+ * since we only currently implement idempotent callbacks anyway.
+ *
+ * We have a single slot backchannel at this time, so we don't bother
+ * checking the used_slots bit array on the table.  The lower layer guarantees
+ * a single outstanding callback request at a time.
+ */
+static __be32
+validate_seqid(const struct nfs4_slot_table *tbl, const struct nfs4_slot *slot,
+		const struct cb_sequenceargs * args)
+{
+	__be32 ret;
+
+	ret = cpu_to_be32(NFS4ERR_BADSLOT);
+	if (args->csa_slotid > tbl->server_highest_slotid)
+		goto out_err;
+
+	/* Replay */
+	if (args->csa_sequenceid == slot->seq_nr) {
+		ret = cpu_to_be32(NFS4ERR_DELAY);
+		if (nfs4_test_locked_slot(tbl, slot->slot_nr))
+			goto out_err;
+
+		/* Signal process_op to set this error on next op */
+		ret = cpu_to_be32(NFS4ERR_RETRY_UNCACHED_REP);
+		if (args->csa_cachethis == 0)
+			goto out_err;
+
+		/* Liar! We never allowed you to set csa_cachethis != 0 */
+		ret = cpu_to_be32(NFS4ERR_SEQ_FALSE_RETRY);
+		goto out_err;
+	}
+
+	/* Note: wraparound relies on seq_nr being of type u32 */
+	/* Misordered request */
+	ret = cpu_to_be32(NFS4ERR_SEQ_MISORDERED);
+	if (args->csa_sequenceid != slot->seq_nr + 1)
+		goto out_err;
+
+	return cpu_to_be32(NFS4_OK);
+
+out_err:
+	trace_nfs4_cb_seqid_err(args, ret);
+	return ret;
+}
+
+/*
+ * For each referring call triple, check the session's slot table for
+ * a match.  If the slot is in use and the sequence numbers match, the
+ * client is still waiting for a response to the original request.
+ */
+static int referring_call_exists(struct nfs_client *clp,
+				  uint32_t nrclists,
+				  struct referring_call_list *rclists,
+				  spinlock_t *lock)
+	__releases(lock)
+	__acquires(lock)
+{
+	int status = 0;
+	int i, j;
+	struct nfs4_session *session;
+	struct nfs4_slot_table *tbl;
+	struct referring_call_list *rclist;
+	struct referring_call *ref;
+
+	/*
+	 * XXX When client trunking is implemented, this becomes
+	 * a session lookup from within the loop
+	 */
+	session = clp->cl_session;
+	tbl = &session->fc_slot_table;
+
+	for (i = 0; i < nrclists; i++) {
+		rclist = &rclists[i];
+		if (memcmp(session->sess_id.data,
+			   rclist->rcl_sessionid.data,
+			   NFS4_MAX_SESSIONID_LEN) != 0)
+			continue;
+
+		for (j = 0; j < rclist->rcl_nrefcalls; j++) {
+			ref = &rclist->rcl_refcalls[j];
+			spin_unlock(lock);
+			status = nfs4_slot_wait_on_seqid(tbl, ref->rc_slotid,
+					ref->rc_sequenceid, HZ >> 1) < 0;
+			spin_lock(lock);
+			if (status)
+				goto out;
+		}
+	}
+
+out:
+	return status;
+}
+
+__be32 nfs4_callback_sequence(void *argp, void *resp,
+			      struct cb_process_state *cps)
+{
+	struct cb_sequenceargs *args = argp;
+	struct cb_sequenceres *res = resp;
+	struct nfs4_slot_table *tbl;
+	struct nfs4_slot *slot;
+	struct nfs_client *clp;
+	int i;
+	__be32 status = htonl(NFS4ERR_BADSESSION);
+
+	clp = nfs4_find_client_sessionid(cps->net, args->csa_addr,
+					 &args->csa_sessionid, cps->minorversion);
+	if (clp == NULL)
+		goto out;
+
+	if (!(clp->cl_session->flags & SESSION4_BACK_CHAN))
+		goto out;
+
+	tbl = &clp->cl_session->bc_slot_table;
+
+	/* Set up res before grabbing the spinlock */
+	memcpy(&res->csr_sessionid, &args->csa_sessionid,
+	       sizeof(res->csr_sessionid));
+	res->csr_sequenceid = args->csa_sequenceid;
+	res->csr_slotid = args->csa_slotid;
+
+	spin_lock(&tbl->slot_tbl_lock);
+	/* state manager is resetting the session */
+	if (test_bit(NFS4_SLOT_TBL_DRAINING, &tbl->slot_tbl_state)) {
+		status = htonl(NFS4ERR_DELAY);
+		/* Return NFS4ERR_BADSESSION if we're draining the session
+		 * in order to reset it.
+		 */
+		if (test_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state))
+			status = htonl(NFS4ERR_BADSESSION);
+		goto out_unlock;
+	}
+
+	status = htonl(NFS4ERR_BADSLOT);
+	slot = nfs4_lookup_slot(tbl, args->csa_slotid);
+	if (IS_ERR(slot))
+		goto out_unlock;
+
+	res->csr_highestslotid = tbl->server_highest_slotid;
+	res->csr_target_highestslotid = tbl->target_highest_slotid;
+
+	status = validate_seqid(tbl, slot, args);
+	if (status)
+		goto out_unlock;
+	if (!nfs4_try_to_lock_slot(tbl, slot)) {
+		status = htonl(NFS4ERR_DELAY);
+		goto out_unlock;
+	}
+	cps->slot = slot;
+
+	/* The ca_maxresponsesize_cached is 0 with no DRC */
+	if (args->csa_cachethis != 0) {
+		status = htonl(NFS4ERR_REP_TOO_BIG_TO_CACHE);
+		goto out_unlock;
+	}
+
+	/*
+	 * Check for pending referring calls.  If a match is found, a
+	 * related callback was received before the response to the original
+	 * call.
+	 */
+	if (referring_call_exists(clp, args->csa_nrclists, args->csa_rclists,
+				&tbl->slot_tbl_lock) < 0) {
+		status = htonl(NFS4ERR_DELAY);
+		goto out_unlock;
+	}
+
+	/*
+	 * RFC5661 20.9.3
+	 * If CB_SEQUENCE returns an error, then the state of the slot
+	 * (sequence ID, cached reply) MUST NOT change.
+	 */
+	slot->seq_nr = args->csa_sequenceid;
+out_unlock:
+	spin_unlock(&tbl->slot_tbl_lock);
+
+out:
+	cps->clp = clp; /* put in nfs4_callback_compound */
+	for (i = 0; i < args->csa_nrclists; i++)
+		kfree(args->csa_rclists[i].rcl_refcalls);
+	kfree(args->csa_rclists);
+
+	if (status == htonl(NFS4ERR_RETRY_UNCACHED_REP)) {
+		cps->drc_status = status;
+		status = 0;
+	} else
+		res->csr_status = status;
+
+	trace_nfs4_cb_sequence(args, res, status);
+	return status;
+}
+
+static bool
+validate_bitmap_values(unsigned int mask)
+{
+	return (mask & ~RCA4_TYPE_MASK_ALL) == 0;
+}
+
+__be32 nfs4_callback_recallany(void *argp, void *resp,
+			       struct cb_process_state *cps)
+{
+	struct cb_recallanyargs *args = argp;
+	__be32 status;
+	fmode_t flags = 0;
+	bool schedule_manager = false;
+
+	status = cpu_to_be32(NFS4ERR_OP_NOT_IN_SESSION);
+	if (!cps->clp) /* set in cb_sequence */
+		goto out;
+
+	dprintk_rcu("NFS: RECALL_ANY callback request from %s\n",
+		rpc_peeraddr2str(cps->clp->cl_rpcclient, RPC_DISPLAY_ADDR));
+
+	status = cpu_to_be32(NFS4ERR_INVAL);
+	if (!validate_bitmap_values(args->craa_type_mask))
+		goto out;
+
+	status = cpu_to_be32(NFS4_OK);
+	if (args->craa_type_mask & BIT(RCA4_TYPE_MASK_RDATA_DLG))
+		flags = FMODE_READ;
+	if (args->craa_type_mask & BIT(RCA4_TYPE_MASK_WDATA_DLG))
+		flags |= FMODE_WRITE;
+	if (flags)
+		nfs_expire_unused_delegation_types(cps->clp, flags);
+
+	if (args->craa_type_mask & BIT(RCA4_TYPE_MASK_FILE_LAYOUT))
+		pnfs_recall_all_layouts(cps->clp);
+
+	if (args->craa_type_mask & BIT(PNFS_FF_RCA4_TYPE_MASK_READ)) {
+		set_bit(NFS4CLNT_RECALL_ANY_LAYOUT_READ, &cps->clp->cl_state);
+		schedule_manager = true;
+	}
+	if (args->craa_type_mask & BIT(PNFS_FF_RCA4_TYPE_MASK_RW)) {
+		set_bit(NFS4CLNT_RECALL_ANY_LAYOUT_RW, &cps->clp->cl_state);
+		schedule_manager = true;
+	}
+	if (schedule_manager)
+		nfs4_schedule_state_manager(cps->clp);
+
+out:
+	dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
+	return status;
+}
+
+/* Reduce the fore channel's max_slots to the target value */
+__be32 nfs4_callback_recallslot(void *argp, void *resp,
+				struct cb_process_state *cps)
+{
+	struct cb_recallslotargs *args = argp;
+	struct nfs4_slot_table *fc_tbl;
+	__be32 status;
+
+	status = htonl(NFS4ERR_OP_NOT_IN_SESSION);
+	if (!cps->clp) /* set in cb_sequence */
+		goto out;
+
+	dprintk_rcu("NFS: CB_RECALL_SLOT request from %s target highest slotid %u\n",
+		rpc_peeraddr2str(cps->clp->cl_rpcclient, RPC_DISPLAY_ADDR),
+		args->crsa_target_highest_slotid);
+
+	fc_tbl = &cps->clp->cl_session->fc_slot_table;
+
+	status = htonl(NFS4_OK);
+
+	nfs41_set_target_slotid(fc_tbl, args->crsa_target_highest_slotid);
+	nfs41_notify_server(cps->clp);
+out:
+	dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
+	return status;
+}
+
+__be32 nfs4_callback_notify_lock(void *argp, void *resp,
+				 struct cb_process_state *cps)
+{
+	struct cb_notify_lock_args *args = argp;
+
+	if (!cps->clp) /* set in cb_sequence */
+		return htonl(NFS4ERR_OP_NOT_IN_SESSION);
+
+	dprintk_rcu("NFS: CB_NOTIFY_LOCK request from %s\n",
+		rpc_peeraddr2str(cps->clp->cl_rpcclient, RPC_DISPLAY_ADDR));
+
+	/* Don't wake anybody if the string looked bogus */
+	if (args->cbnl_valid)
+		__wake_up(&cps->clp->cl_lock_waitq, TASK_NORMAL, 0, args);
+
+	return htonl(NFS4_OK);
+}
+#endif /* CONFIG_NFS_V4_1 */
+#ifdef CONFIG_NFS_V4_2
+static void nfs4_copy_cb_args(struct nfs4_copy_state *cp_state,
+				struct cb_offloadargs *args)
+{
+	cp_state->count = args->wr_count;
+	cp_state->error = args->error;
+	if (!args->error) {
+		cp_state->verf.committed = args->wr_writeverf.committed;
+		memcpy(&cp_state->verf.verifier.data[0],
+			&args->wr_writeverf.verifier.data[0],
+			NFS4_VERIFIER_SIZE);
+	}
+}
+
+__be32 nfs4_callback_offload(void *data, void *dummy,
+			     struct cb_process_state *cps)
+{
+	struct cb_offloadargs *args = data;
+	struct nfs_server *server;
+	struct nfs4_copy_state *copy, *tmp_copy;
+	bool found = false;
+
+	copy = kzalloc(sizeof(struct nfs4_copy_state), GFP_NOFS);
+	if (!copy)
+		return htonl(NFS4ERR_SERVERFAULT);
+
+	spin_lock(&cps->clp->cl_lock);
+	rcu_read_lock();
+	list_for_each_entry_rcu(server, &cps->clp->cl_superblocks,
+				client_link) {
+		list_for_each_entry(tmp_copy, &server->ss_copies, copies) {
+			if (memcmp(args->coa_stateid.other,
+					tmp_copy->stateid.other,
+					sizeof(args->coa_stateid.other)))
+				continue;
+			nfs4_copy_cb_args(tmp_copy, args);
+			complete(&tmp_copy->completion);
+			found = true;
+			goto out;
+		}
+	}
+out:
+	rcu_read_unlock();
+	if (!found) {
+		memcpy(&copy->stateid, &args->coa_stateid, NFS4_STATEID_SIZE);
+		nfs4_copy_cb_args(copy, args);
+		list_add_tail(&copy->copies, &cps->clp->pending_cb_stateids);
+	} else
+		kfree(copy);
+	spin_unlock(&cps->clp->cl_lock);
+
+	return 0;
+}
+#endif /* CONFIG_NFS_V4_2 */
diff --git a/fs/nfs/callback_xdr.c b/fs/nfs/callback_xdr.c
new file mode 100644
index 000000000..ca8a4aa35
--- /dev/null
+++ b/fs/nfs/callback_xdr.c
@@ -0,0 +1,1091 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/nfs/callback_xdr.c
+ *
+ * Copyright (C) 2004 Trond Myklebust
+ *
+ * NFSv4 callback encode/decode procedures
+ */
+#include <linux/kernel.h>
+#include <linux/sunrpc/svc.h>
+#include <linux/nfs4.h>
+#include <linux/nfs_fs.h>
+#include <linux/ratelimit.h>
+#include <linux/printk.h>
+#include <linux/slab.h>
+#include <linux/sunrpc/bc_xprt.h>
+#include "nfs4_fs.h"
+#include "callback.h"
+#include "internal.h"
+#include "nfs4session.h"
+#include "nfs4trace.h"
+
+#define CB_OP_TAGLEN_MAXSZ		(512)
+#define CB_OP_HDR_RES_MAXSZ		(2 * 4) // opcode, status
+#define CB_OP_GETATTR_BITMAP_MAXSZ	(4 * 4) // bitmap length, 3 bitmaps
+#define CB_OP_GETATTR_RES_MAXSZ		(CB_OP_HDR_RES_MAXSZ + \
+					 CB_OP_GETATTR_BITMAP_MAXSZ + \
+					 /* change, size, ctime, mtime */\
+					 (2 + 2 + 3 + 3) * 4)
+#define CB_OP_RECALL_RES_MAXSZ		(CB_OP_HDR_RES_MAXSZ)
+
+#if defined(CONFIG_NFS_V4_1)
+#define CB_OP_LAYOUTRECALL_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
+#define CB_OP_DEVICENOTIFY_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
+#define CB_OP_SEQUENCE_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ + \
+					 NFS4_MAX_SESSIONID_LEN + \
+					 (1 + 3) * 4) // seqid, 3 slotids
+#define CB_OP_RECALLANY_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
+#define CB_OP_RECALLSLOT_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
+#define CB_OP_NOTIFY_LOCK_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)
+#endif /* CONFIG_NFS_V4_1 */
+#ifdef CONFIG_NFS_V4_2
+#define CB_OP_OFFLOAD_RES_MAXSZ		(CB_OP_HDR_RES_MAXSZ)
+#endif /* CONFIG_NFS_V4_2 */
+
+#define NFSDBG_FACILITY NFSDBG_CALLBACK
+
+/* Internal error code */
+#define NFS4ERR_RESOURCE_HDR	11050
+
+struct callback_op {
+	__be32 (*process_op)(void *, void *, struct cb_process_state *);
+	__be32 (*decode_args)(struct svc_rqst *, struct xdr_stream *, void *);
+	__be32 (*encode_res)(struct svc_rqst *, struct xdr_stream *,
+			const void *);
+	long res_maxsize;
+};
+
+static struct callback_op callback_ops[];
+
+static __be32 nfs4_callback_null(struct svc_rqst *rqstp)
+{
+	return htonl(NFS4_OK);
+}
+
+static int nfs4_decode_void(struct svc_rqst *rqstp, __be32 *p)
+{
+	return xdr_argsize_check(rqstp, p);
+}
+
+static int nfs4_encode_void(struct svc_rqst *rqstp, __be32 *p)
+{
+	return xdr_ressize_check(rqstp, p);
+}
+
+static __be32 decode_string(struct xdr_stream *xdr, unsigned int *len,
+		const char **str, size_t maxlen)
+{
+	ssize_t err;
+
+	err = xdr_stream_decode_opaque_inline(xdr, (void **)str, maxlen);
+	if (err < 0)
+		return cpu_to_be32(NFS4ERR_RESOURCE);
+	*len = err;
+	return 0;
+}
+
+static __be32 decode_fh(struct xdr_stream *xdr, struct nfs_fh *fh)
+{
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(p == NULL))
+		return htonl(NFS4ERR_RESOURCE);
+	fh->size = ntohl(*p);
+	if (fh->size > NFS4_FHSIZE)
+		return htonl(NFS4ERR_BADHANDLE);
+	p = xdr_inline_decode(xdr, fh->size);
+	if (unlikely(p == NULL))
+		return htonl(NFS4ERR_RESOURCE);
+	memcpy(&fh->data[0], p, fh->size);
+	memset(&fh->data[fh->size], 0, sizeof(fh->data) - fh->size);
+	return 0;
+}
+
+static __be32 decode_bitmap(struct xdr_stream *xdr, uint32_t *bitmap)
+{
+	__be32 *p;
+	unsigned int attrlen;
+
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(p == NULL))
+		return htonl(NFS4ERR_RESOURCE);
+	attrlen = ntohl(*p);
+	p = xdr_inline_decode(xdr, attrlen << 2);
+	if (unlikely(p == NULL))
+		return htonl(NFS4ERR_RESOURCE);
+	if (likely(attrlen > 0))
+		bitmap[0] = ntohl(*p++);
+	if (attrlen > 1)
+		bitmap[1] = ntohl(*p);
+	return 0;
+}
+
+static __be32 decode_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
+{
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, NFS4_STATEID_SIZE);
+	if (unlikely(p == NULL))
+		return htonl(NFS4ERR_RESOURCE);
+	memcpy(stateid->data, p, NFS4_STATEID_SIZE);
+	return 0;
+}
+
+static __be32 decode_delegation_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
+{
+	stateid->type = NFS4_DELEGATION_STATEID_TYPE;
+	return decode_stateid(xdr, stateid);
+}
+
+static __be32 decode_compound_hdr_arg(struct xdr_stream *xdr, struct cb_compound_hdr_arg *hdr)
+{
+	__be32 *p;
+	__be32 status;
+
+	status = decode_string(xdr, &hdr->taglen, &hdr->tag, CB_OP_TAGLEN_MAXSZ);
+	if (unlikely(status != 0))
+		return status;
+	p = xdr_inline_decode(xdr, 12);
+	if (unlikely(p == NULL))
+		return htonl(NFS4ERR_RESOURCE);
+	hdr->minorversion = ntohl(*p++);
+	/* Check for minor version support */
+	if (hdr->minorversion <= NFS4_MAX_MINOR_VERSION) {
+		hdr->cb_ident = ntohl(*p++); /* ignored by v4.1 and v4.2 */
+	} else {
+		pr_warn_ratelimited("NFS: %s: NFSv4 server callback with "
+			"illegal minor version %u!\n",
+			__func__, hdr->minorversion);
+		return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
+	}
+	hdr->nops = ntohl(*p);
+	return 0;
+}
+
+static __be32 decode_op_hdr(struct xdr_stream *xdr, unsigned int *op)
+{
+	__be32 *p;
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(p == NULL))
+		return htonl(NFS4ERR_RESOURCE_HDR);
+	*op = ntohl(*p);
+	return 0;
+}
+
+static __be32 decode_getattr_args(struct svc_rqst *rqstp,
+		struct xdr_stream *xdr, void *argp)
+{
+	struct cb_getattrargs *args = argp;
+	__be32 status;
+
+	status = decode_fh(xdr, &args->fh);
+	if (unlikely(status != 0))
+		return status;
+	return decode_bitmap(xdr, args->bitmap);
+}
+
+static __be32 decode_recall_args(struct svc_rqst *rqstp,
+		struct xdr_stream *xdr, void *argp)
+{
+	struct cb_recallargs *args = argp;
+	__be32 *p;
+	__be32 status;
+
+	status = decode_delegation_stateid(xdr, &args->stateid);
+	if (unlikely(status != 0))
+		return status;
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(p == NULL))
+		return htonl(NFS4ERR_RESOURCE);
+	args->truncate = ntohl(*p);
+	return decode_fh(xdr, &args->fh);
+}
+
+#if defined(CONFIG_NFS_V4_1)
+static __be32 decode_layout_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
+{
+	stateid->type = NFS4_LAYOUT_STATEID_TYPE;
+	return decode_stateid(xdr, stateid);
+}
+
+static __be32 decode_layoutrecall_args(struct svc_rqst *rqstp,
+				       struct xdr_stream *xdr, void *argp)
+{
+	struct cb_layoutrecallargs *args = argp;
+	__be32 *p;
+	__be32 status = 0;
+	uint32_t iomode;
+
+	p = xdr_inline_decode(xdr, 4 * sizeof(uint32_t));
+	if (unlikely(p == NULL))
+		return htonl(NFS4ERR_BADXDR);
+
+	args->cbl_layout_type = ntohl(*p++);
+	/* Depite the spec's xdr, iomode really belongs in the FILE switch,
+	 * as it is unusable and ignored with the other types.
+	 */
+	iomode = ntohl(*p++);
+	args->cbl_layoutchanged = ntohl(*p++);
+	args->cbl_recall_type = ntohl(*p++);
+
+	if (args->cbl_recall_type == RETURN_FILE) {
+		args->cbl_range.iomode = iomode;
+		status = decode_fh(xdr, &args->cbl_fh);
+		if (unlikely(status != 0))
+			return status;
+
+		p = xdr_inline_decode(xdr, 2 * sizeof(uint64_t));
+		if (unlikely(p == NULL))
+			return htonl(NFS4ERR_BADXDR);
+		p = xdr_decode_hyper(p, &args->cbl_range.offset);
+		p = xdr_decode_hyper(p, &args->cbl_range.length);
+		return decode_layout_stateid(xdr, &args->cbl_stateid);
+	} else if (args->cbl_recall_type == RETURN_FSID) {
+		p = xdr_inline_decode(xdr, 2 * sizeof(uint64_t));
+		if (unlikely(p == NULL))
+			return htonl(NFS4ERR_BADXDR);
+		p = xdr_decode_hyper(p, &args->cbl_fsid.major);
+		p = xdr_decode_hyper(p, &args->cbl_fsid.minor);
+	} else if (args->cbl_recall_type != RETURN_ALL)
+		return htonl(NFS4ERR_BADXDR);
+	return 0;
+}
+
+static
+__be32 decode_devicenotify_args(struct svc_rqst *rqstp,
+				struct xdr_stream *xdr,
+				void *argp)
+{
+	struct cb_devicenotifyargs *args = argp;
+	uint32_t tmp, n, i;
+	__be32 *p;
+	__be32 status = 0;
+
+	/* Num of device notifications */
+	p = xdr_inline_decode(xdr, sizeof(uint32_t));
+	if (unlikely(p == NULL)) {
+		status = htonl(NFS4ERR_BADXDR);
+		goto out;
+	}
+	n = ntohl(*p++);
+	if (n == 0)
+		goto out;
+
+	args->devs = kmalloc_array(n, sizeof(*args->devs), GFP_KERNEL);
+	if (!args->devs) {
+		status = htonl(NFS4ERR_DELAY);
+		goto out;
+	}
+
+	/* Decode each dev notification */
+	for (i = 0; i < n; i++) {
+		struct cb_devicenotifyitem *dev = &args->devs[i];
+
+		p = xdr_inline_decode(xdr, (4 * sizeof(uint32_t)) +
+				      NFS4_DEVICEID4_SIZE);
+		if (unlikely(p == NULL)) {
+			status = htonl(NFS4ERR_BADXDR);
+			goto err;
+		}
+
+		tmp = ntohl(*p++);	/* bitmap size */
+		if (tmp != 1) {
+			status = htonl(NFS4ERR_INVAL);
+			goto err;
+		}
+		dev->cbd_notify_type = ntohl(*p++);
+		if (dev->cbd_notify_type != NOTIFY_DEVICEID4_CHANGE &&
+		    dev->cbd_notify_type != NOTIFY_DEVICEID4_DELETE) {
+			status = htonl(NFS4ERR_INVAL);
+			goto err;
+		}
+
+		tmp = ntohl(*p++);	/* opaque size */
+		if (((dev->cbd_notify_type == NOTIFY_DEVICEID4_CHANGE) &&
+		     (tmp != NFS4_DEVICEID4_SIZE + 8)) ||
+		    ((dev->cbd_notify_type == NOTIFY_DEVICEID4_DELETE) &&
+		     (tmp != NFS4_DEVICEID4_SIZE + 4))) {
+			status = htonl(NFS4ERR_INVAL);
+			goto err;
+		}
+		dev->cbd_layout_type = ntohl(*p++);
+		memcpy(dev->cbd_dev_id.data, p, NFS4_DEVICEID4_SIZE);
+		p += XDR_QUADLEN(NFS4_DEVICEID4_SIZE);
+
+		if (dev->cbd_layout_type == NOTIFY_DEVICEID4_CHANGE) {
+			p = xdr_inline_decode(xdr, sizeof(uint32_t));
+			if (unlikely(p == NULL)) {
+				status = htonl(NFS4ERR_BADXDR);
+				goto err;
+			}
+			dev->cbd_immediate = ntohl(*p++);
+		} else {
+			dev->cbd_immediate = 0;
+		}
+
+		dprintk("%s: type %d layout 0x%x immediate %d\n",
+			__func__, dev->cbd_notify_type, dev->cbd_layout_type,
+			dev->cbd_immediate);
+	}
+	args->ndevs = n;
+	dprintk("%s: ndevs %d\n", __func__, args->ndevs);
+	return 0;
+err:
+	kfree(args->devs);
+out:
+	args->devs = NULL;
+	args->ndevs = 0;
+	dprintk("%s: status %d ndevs %d\n",
+		__func__, ntohl(status), args->ndevs);
+	return status;
+}
+
+static __be32 decode_sessionid(struct xdr_stream *xdr,
+				 struct nfs4_sessionid *sid)
+{
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, NFS4_MAX_SESSIONID_LEN);
+	if (unlikely(p == NULL))
+		return htonl(NFS4ERR_RESOURCE);
+
+	memcpy(sid->data, p, NFS4_MAX_SESSIONID_LEN);
+	return 0;
+}
+
+static __be32 decode_rc_list(struct xdr_stream *xdr,
+			       struct referring_call_list *rc_list)
+{
+	__be32 *p;
+	int i;
+	__be32 status;
+
+	status = decode_sessionid(xdr, &rc_list->rcl_sessionid);
+	if (status)
+		goto out;
+
+	status = htonl(NFS4ERR_RESOURCE);
+	p = xdr_inline_decode(xdr, sizeof(uint32_t));
+	if (unlikely(p == NULL))
+		goto out;
+
+	rc_list->rcl_nrefcalls = ntohl(*p++);
+	if (rc_list->rcl_nrefcalls) {
+		p = xdr_inline_decode(xdr,
+			     rc_list->rcl_nrefcalls * 2 * sizeof(uint32_t));
+		if (unlikely(p == NULL))
+			goto out;
+		rc_list->rcl_refcalls = kmalloc_array(rc_list->rcl_nrefcalls,
+						sizeof(*rc_list->rcl_refcalls),
+						GFP_KERNEL);
+		if (unlikely(rc_list->rcl_refcalls == NULL))
+			goto out;
+		for (i = 0; i < rc_list->rcl_nrefcalls; i++) {
+			rc_list->rcl_refcalls[i].rc_sequenceid = ntohl(*p++);
+			rc_list->rcl_refcalls[i].rc_slotid = ntohl(*p++);
+		}
+	}
+	status = 0;
+
+out:
+	return status;
+}
+
+static __be32 decode_cb_sequence_args(struct svc_rqst *rqstp,
+					struct xdr_stream *xdr,
+					void *argp)
+{
+	struct cb_sequenceargs *args = argp;
+	__be32 *p;
+	int i;
+	__be32 status;
+
+	status = decode_sessionid(xdr, &args->csa_sessionid);
+	if (status)
+		return status;
+
+	p = xdr_inline_decode(xdr, 5 * sizeof(uint32_t));
+	if (unlikely(p == NULL))
+		return htonl(NFS4ERR_RESOURCE);
+
+	args->csa_addr = svc_addr(rqstp);
+	args->csa_sequenceid = ntohl(*p++);
+	args->csa_slotid = ntohl(*p++);
+	args->csa_highestslotid = ntohl(*p++);
+	args->csa_cachethis = ntohl(*p++);
+	args->csa_nrclists = ntohl(*p++);
+	args->csa_rclists = NULL;
+	if (args->csa_nrclists) {
+		args->csa_rclists = kmalloc_array(args->csa_nrclists,
+						  sizeof(*args->csa_rclists),
+						  GFP_KERNEL);
+		if (unlikely(args->csa_rclists == NULL))
+			return htonl(NFS4ERR_RESOURCE);
+
+		for (i = 0; i < args->csa_nrclists; i++) {
+			status = decode_rc_list(xdr, &args->csa_rclists[i]);
+			if (status) {
+				args->csa_nrclists = i;
+				goto out_free;
+			}
+		}
+	}
+	return 0;
+
+out_free:
+	for (i = 0; i < args->csa_nrclists; i++)
+		kfree(args->csa_rclists[i].rcl_refcalls);
+	kfree(args->csa_rclists);
+	return status;
+}
+
+static __be32 decode_recallany_args(struct svc_rqst *rqstp,
+				      struct xdr_stream *xdr,
+				      void *argp)
+{
+	struct cb_recallanyargs *args = argp;
+	uint32_t bitmap[2];
+	__be32 *p, status;
+
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(p == NULL))
+		return htonl(NFS4ERR_BADXDR);
+	args->craa_objs_to_keep = ntohl(*p++);
+	status = decode_bitmap(xdr, bitmap);
+	if (unlikely(status))
+		return status;
+	args->craa_type_mask = bitmap[0];
+
+	return 0;
+}
+
+static __be32 decode_recallslot_args(struct svc_rqst *rqstp,
+					struct xdr_stream *xdr,
+					void *argp)
+{
+	struct cb_recallslotargs *args = argp;
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(p == NULL))
+		return htonl(NFS4ERR_BADXDR);
+	args->crsa_target_highest_slotid = ntohl(*p++);
+	return 0;
+}
+
+static __be32 decode_lockowner(struct xdr_stream *xdr, struct cb_notify_lock_args *args)
+{
+	__be32		*p;
+	unsigned int	len;
+
+	p = xdr_inline_decode(xdr, 12);
+	if (unlikely(p == NULL))
+		return htonl(NFS4ERR_BADXDR);
+
+	p = xdr_decode_hyper(p, &args->cbnl_owner.clientid);
+	len = be32_to_cpu(*p);
+
+	p = xdr_inline_decode(xdr, len);
+	if (unlikely(p == NULL))
+		return htonl(NFS4ERR_BADXDR);
+
+	/* Only try to decode if the length is right */
+	if (len == 20) {
+		p += 2;	/* skip "lock id:" */
+		args->cbnl_owner.s_dev = be32_to_cpu(*p++);
+		xdr_decode_hyper(p, &args->cbnl_owner.id);
+		args->cbnl_valid = true;
+	} else {
+		args->cbnl_owner.s_dev = 0;
+		args->cbnl_owner.id = 0;
+		args->cbnl_valid = false;
+	}
+	return 0;
+}
+
+static __be32 decode_notify_lock_args(struct svc_rqst *rqstp,
+		struct xdr_stream *xdr, void *argp)
+{
+	struct cb_notify_lock_args *args = argp;
+	__be32 status;
+
+	status = decode_fh(xdr, &args->cbnl_fh);
+	if (unlikely(status != 0))
+		return status;
+	return decode_lockowner(xdr, args);
+}
+
+#endif /* CONFIG_NFS_V4_1 */
+#ifdef CONFIG_NFS_V4_2
+static __be32 decode_write_response(struct xdr_stream *xdr,
+					struct cb_offloadargs *args)
+{
+	__be32 *p;
+
+	/* skip the always zero field */
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(!p))
+		goto out;
+	p++;
+
+	/* decode count, stable_how, verifier */
+	p = xdr_inline_decode(xdr, 8 + 4);
+	if (unlikely(!p))
+		goto out;
+	p = xdr_decode_hyper(p, &args->wr_count);
+	args->wr_writeverf.committed = be32_to_cpup(p);
+	p = xdr_inline_decode(xdr, NFS4_VERIFIER_SIZE);
+	if (likely(p)) {
+		memcpy(&args->wr_writeverf.verifier.data[0], p,
+			NFS4_VERIFIER_SIZE);
+		return 0;
+	}
+out:
+	return htonl(NFS4ERR_RESOURCE);
+}
+
+static __be32 decode_offload_args(struct svc_rqst *rqstp,
+					struct xdr_stream *xdr,
+					void *data)
+{
+	struct cb_offloadargs *args = data;
+	__be32 *p;
+	__be32 status;
+
+	/* decode fh */
+	status = decode_fh(xdr, &args->coa_fh);
+	if (unlikely(status != 0))
+		return status;
+
+	/* decode stateid */
+	status = decode_stateid(xdr, &args->coa_stateid);
+	if (unlikely(status != 0))
+		return status;
+
+	/* decode status */
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(!p))
+		goto out;
+	args->error = ntohl(*p++);
+	if (!args->error) {
+		status = decode_write_response(xdr, args);
+		if (unlikely(status != 0))
+			return status;
+	} else {
+		p = xdr_inline_decode(xdr, 8);
+		if (unlikely(!p))
+			goto out;
+		p = xdr_decode_hyper(p, &args->wr_count);
+	}
+	return 0;
+out:
+	return htonl(NFS4ERR_RESOURCE);
+}
+#endif /* CONFIG_NFS_V4_2 */
+static __be32 encode_string(struct xdr_stream *xdr, unsigned int len, const char *str)
+{
+	if (unlikely(xdr_stream_encode_opaque(xdr, str, len) < 0))
+		return cpu_to_be32(NFS4ERR_RESOURCE);
+	return 0;
+}
+
+static __be32 encode_attr_bitmap(struct xdr_stream *xdr, const uint32_t *bitmap, size_t sz)
+{
+	if (xdr_stream_encode_uint32_array(xdr, bitmap, sz) < 0)
+		return cpu_to_be32(NFS4ERR_RESOURCE);
+	return 0;
+}
+
+static __be32 encode_attr_change(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t change)
+{
+	__be32 *p;
+
+	if (!(bitmap[0] & FATTR4_WORD0_CHANGE))
+		return 0;
+	p = xdr_reserve_space(xdr, 8);
+	if (unlikely(!p))
+		return htonl(NFS4ERR_RESOURCE);
+	p = xdr_encode_hyper(p, change);
+	return 0;
+}
+
+static __be32 encode_attr_size(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t size)
+{
+	__be32 *p;
+
+	if (!(bitmap[0] & FATTR4_WORD0_SIZE))
+		return 0;
+	p = xdr_reserve_space(xdr, 8);
+	if (unlikely(!p))
+		return htonl(NFS4ERR_RESOURCE);
+	p = xdr_encode_hyper(p, size);
+	return 0;
+}
+
+static __be32 encode_attr_time(struct xdr_stream *xdr, const struct timespec64 *time)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 12);
+	if (unlikely(!p))
+		return htonl(NFS4ERR_RESOURCE);
+	p = xdr_encode_hyper(p, time->tv_sec);
+	*p = htonl(time->tv_nsec);
+	return 0;
+}
+
+static __be32 encode_attr_ctime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec64 *time)
+{
+	if (!(bitmap[1] & FATTR4_WORD1_TIME_METADATA))
+		return 0;
+	return encode_attr_time(xdr,time);
+}
+
+static __be32 encode_attr_mtime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec64 *time)
+{
+	if (!(bitmap[1] & FATTR4_WORD1_TIME_MODIFY))
+		return 0;
+	return encode_attr_time(xdr,time);
+}
+
+static __be32 encode_compound_hdr_res(struct xdr_stream *xdr, struct cb_compound_hdr_res *hdr)
+{
+	__be32 status;
+
+	hdr->status = xdr_reserve_space(xdr, 4);
+	if (unlikely(hdr->status == NULL))
+		return htonl(NFS4ERR_RESOURCE);
+	status = encode_string(xdr, hdr->taglen, hdr->tag);
+	if (unlikely(status != 0))
+		return status;
+	hdr->nops = xdr_reserve_space(xdr, 4);
+	if (unlikely(hdr->nops == NULL))
+		return htonl(NFS4ERR_RESOURCE);
+	return 0;
+}
+
+static __be32 encode_op_hdr(struct xdr_stream *xdr, uint32_t op, __be32 res)
+{
+	__be32 *p;
+	
+	p = xdr_reserve_space(xdr, 8);
+	if (unlikely(p == NULL))
+		return htonl(NFS4ERR_RESOURCE_HDR);
+	*p++ = htonl(op);
+	*p = res;
+	return 0;
+}
+
+static __be32 encode_getattr_res(struct svc_rqst *rqstp, struct xdr_stream *xdr,
+		const void *resp)
+{
+	const struct cb_getattrres *res = resp;
+	__be32 *savep = NULL;
+	__be32 status = res->status;
+	
+	if (unlikely(status != 0))
+		goto out;
+	status = encode_attr_bitmap(xdr, res->bitmap, ARRAY_SIZE(res->bitmap));
+	if (unlikely(status != 0))
+		goto out;
+	status = cpu_to_be32(NFS4ERR_RESOURCE);
+	savep = xdr_reserve_space(xdr, sizeof(*savep));
+	if (unlikely(!savep))
+		goto out;
+	status = encode_attr_change(xdr, res->bitmap, res->change_attr);
+	if (unlikely(status != 0))
+		goto out;
+	status = encode_attr_size(xdr, res->bitmap, res->size);
+	if (unlikely(status != 0))
+		goto out;
+	status = encode_attr_ctime(xdr, res->bitmap, &res->ctime);
+	if (unlikely(status != 0))
+		goto out;
+	status = encode_attr_mtime(xdr, res->bitmap, &res->mtime);
+	*savep = htonl((unsigned int)((char *)xdr->p - (char *)(savep+1)));
+out:
+	return status;
+}
+
+#if defined(CONFIG_NFS_V4_1)
+
+static __be32 encode_sessionid(struct xdr_stream *xdr,
+				 const struct nfs4_sessionid *sid)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN);
+	if (unlikely(p == NULL))
+		return htonl(NFS4ERR_RESOURCE);
+
+	memcpy(p, sid, NFS4_MAX_SESSIONID_LEN);
+	return 0;
+}
+
+static __be32 encode_cb_sequence_res(struct svc_rqst *rqstp,
+				       struct xdr_stream *xdr,
+				       const void *resp)
+{
+	const struct cb_sequenceres *res = resp;
+	__be32 *p;
+	__be32 status = res->csr_status;
+
+	if (unlikely(status != 0))
+		return status;
+
+	status = encode_sessionid(xdr, &res->csr_sessionid);
+	if (status)
+		return status;
+
+	p = xdr_reserve_space(xdr, 4 * sizeof(uint32_t));
+	if (unlikely(p == NULL))
+		return htonl(NFS4ERR_RESOURCE);
+
+	*p++ = htonl(res->csr_sequenceid);
+	*p++ = htonl(res->csr_slotid);
+	*p++ = htonl(res->csr_highestslotid);
+	*p++ = htonl(res->csr_target_highestslotid);
+	return 0;
+}
+
+static __be32
+preprocess_nfs41_op(int nop, unsigned int op_nr, struct callback_op **op)
+{
+	if (op_nr == OP_CB_SEQUENCE) {
+		if (nop != 0)
+			return htonl(NFS4ERR_SEQUENCE_POS);
+	} else {
+		if (nop == 0)
+			return htonl(NFS4ERR_OP_NOT_IN_SESSION);
+	}
+
+	switch (op_nr) {
+	case OP_CB_GETATTR:
+	case OP_CB_RECALL:
+	case OP_CB_SEQUENCE:
+	case OP_CB_RECALL_ANY:
+	case OP_CB_RECALL_SLOT:
+	case OP_CB_LAYOUTRECALL:
+	case OP_CB_NOTIFY_DEVICEID:
+	case OP_CB_NOTIFY_LOCK:
+		*op = &callback_ops[op_nr];
+		break;
+
+	case OP_CB_NOTIFY:
+	case OP_CB_PUSH_DELEG:
+	case OP_CB_RECALLABLE_OBJ_AVAIL:
+	case OP_CB_WANTS_CANCELLED:
+		return htonl(NFS4ERR_NOTSUPP);
+
+	default:
+		return htonl(NFS4ERR_OP_ILLEGAL);
+	}
+
+	return htonl(NFS_OK);
+}
+
+static void nfs4_callback_free_slot(struct nfs4_session *session,
+		struct nfs4_slot *slot)
+{
+	struct nfs4_slot_table *tbl = &session->bc_slot_table;
+
+	spin_lock(&tbl->slot_tbl_lock);
+	/*
+	 * Let the state manager know callback processing done.
+	 * A single slot, so highest used slotid is either 0 or -1
+	 */
+	nfs4_free_slot(tbl, slot);
+	spin_unlock(&tbl->slot_tbl_lock);
+}
+
+static void nfs4_cb_free_slot(struct cb_process_state *cps)
+{
+	if (cps->slot) {
+		nfs4_callback_free_slot(cps->clp->cl_session, cps->slot);
+		cps->slot = NULL;
+	}
+}
+
+#else /* CONFIG_NFS_V4_1 */
+
+static __be32
+preprocess_nfs41_op(int nop, unsigned int op_nr, struct callback_op **op)
+{
+	return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
+}
+
+static void nfs4_cb_free_slot(struct cb_process_state *cps)
+{
+}
+#endif /* CONFIG_NFS_V4_1 */
+
+#ifdef CONFIG_NFS_V4_2
+static __be32
+preprocess_nfs42_op(int nop, unsigned int op_nr, struct callback_op **op)
+{
+	__be32 status = preprocess_nfs41_op(nop, op_nr, op);
+	if (status != htonl(NFS4ERR_OP_ILLEGAL))
+		return status;
+
+	if (op_nr == OP_CB_OFFLOAD) {
+		*op = &callback_ops[op_nr];
+		return htonl(NFS_OK);
+	} else
+		return htonl(NFS4ERR_NOTSUPP);
+	return htonl(NFS4ERR_OP_ILLEGAL);
+}
+#else /* CONFIG_NFS_V4_2 */
+static __be32
+preprocess_nfs42_op(int nop, unsigned int op_nr, struct callback_op **op)
+{
+	return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
+}
+#endif /* CONFIG_NFS_V4_2 */
+
+static __be32
+preprocess_nfs4_op(unsigned int op_nr, struct callback_op **op)
+{
+	switch (op_nr) {
+	case OP_CB_GETATTR:
+	case OP_CB_RECALL:
+		*op = &callback_ops[op_nr];
+		break;
+	default:
+		return htonl(NFS4ERR_OP_ILLEGAL);
+	}
+
+	return htonl(NFS_OK);
+}
+
+static __be32 process_op(int nop, struct svc_rqst *rqstp,
+		struct xdr_stream *xdr_in, void *argp,
+		struct xdr_stream *xdr_out, void *resp,
+		struct cb_process_state *cps)
+{
+	struct callback_op *op = &callback_ops[0];
+	unsigned int op_nr;
+	__be32 status;
+	long maxlen;
+	__be32 res;
+
+	status = decode_op_hdr(xdr_in, &op_nr);
+	if (unlikely(status))
+		return status;
+
+	switch (cps->minorversion) {
+	case 0:
+		status = preprocess_nfs4_op(op_nr, &op);
+		break;
+	case 1:
+		status = preprocess_nfs41_op(nop, op_nr, &op);
+		break;
+	case 2:
+		status = preprocess_nfs42_op(nop, op_nr, &op);
+		break;
+	default:
+		status = htonl(NFS4ERR_MINOR_VERS_MISMATCH);
+	}
+
+	if (status == htonl(NFS4ERR_OP_ILLEGAL))
+		op_nr = OP_CB_ILLEGAL;
+	if (status)
+		goto encode_hdr;
+
+	if (cps->drc_status) {
+		status = cps->drc_status;
+		goto encode_hdr;
+	}
+
+	maxlen = xdr_out->end - xdr_out->p;
+	if (maxlen > 0 && maxlen < PAGE_SIZE) {
+		status = op->decode_args(rqstp, xdr_in, argp);
+		if (likely(status == 0))
+			status = op->process_op(argp, resp, cps);
+	} else
+		status = htonl(NFS4ERR_RESOURCE);
+
+encode_hdr:
+	res = encode_op_hdr(xdr_out, op_nr, status);
+	if (unlikely(res))
+		return res;
+	if (op->encode_res != NULL && status == 0)
+		status = op->encode_res(rqstp, xdr_out, resp);
+	return status;
+}
+
+/*
+ * Decode, process and encode a COMPOUND
+ */
+static __be32 nfs4_callback_compound(struct svc_rqst *rqstp)
+{
+	struct cb_compound_hdr_arg hdr_arg = { 0 };
+	struct cb_compound_hdr_res hdr_res = { NULL };
+	struct xdr_stream xdr_in, xdr_out;
+	__be32 *p, status;
+	struct cb_process_state cps = {
+		.drc_status = 0,
+		.clp = NULL,
+		.net = SVC_NET(rqstp),
+	};
+	unsigned int nops = 0;
+
+	xdr_init_decode(&xdr_in, &rqstp->rq_arg,
+			rqstp->rq_arg.head[0].iov_base, NULL);
+
+	p = (__be32*)((char *)rqstp->rq_res.head[0].iov_base + rqstp->rq_res.head[0].iov_len);
+	xdr_init_encode(&xdr_out, &rqstp->rq_res, p, NULL);
+
+	status = decode_compound_hdr_arg(&xdr_in, &hdr_arg);
+	if (status == htonl(NFS4ERR_RESOURCE))
+		return rpc_garbage_args;
+
+	if (hdr_arg.minorversion == 0) {
+		cps.clp = nfs4_find_client_ident(SVC_NET(rqstp), hdr_arg.cb_ident);
+		if (!cps.clp) {
+			trace_nfs_cb_no_clp(rqstp->rq_xid, hdr_arg.cb_ident);
+			goto out_invalidcred;
+		}
+		if (!check_gss_callback_principal(cps.clp, rqstp)) {
+			trace_nfs_cb_badprinc(rqstp->rq_xid, hdr_arg.cb_ident);
+			nfs_put_client(cps.clp);
+			goto out_invalidcred;
+		}
+	}
+
+	cps.minorversion = hdr_arg.minorversion;
+	hdr_res.taglen = hdr_arg.taglen;
+	hdr_res.tag = hdr_arg.tag;
+	if (encode_compound_hdr_res(&xdr_out, &hdr_res) != 0) {
+		if (cps.clp)
+			nfs_put_client(cps.clp);
+		return rpc_system_err;
+	}
+	while (status == 0 && nops != hdr_arg.nops) {
+		status = process_op(nops, rqstp, &xdr_in,
+				    rqstp->rq_argp, &xdr_out, rqstp->rq_resp,
+				    &cps);
+		nops++;
+	}
+
+	/* Buffer overflow in decode_ops_hdr or encode_ops_hdr. Return
+	* resource error in cb_compound status without returning op */
+	if (unlikely(status == htonl(NFS4ERR_RESOURCE_HDR))) {
+		status = htonl(NFS4ERR_RESOURCE);
+		nops--;
+	}
+
+	*hdr_res.status = status;
+	*hdr_res.nops = htonl(nops);
+	nfs4_cb_free_slot(&cps);
+	nfs_put_client(cps.clp);
+	return rpc_success;
+
+out_invalidcred:
+	pr_warn_ratelimited("NFS: NFSv4 callback contains invalid cred\n");
+	return svc_return_autherr(rqstp, rpc_autherr_badcred);
+}
+
+/*
+ * Define NFS4 callback COMPOUND ops.
+ */
+static struct callback_op callback_ops[] = {
+	[0] = {
+		.res_maxsize = CB_OP_HDR_RES_MAXSZ,
+	},
+	[OP_CB_GETATTR] = {
+		.process_op = nfs4_callback_getattr,
+		.decode_args = decode_getattr_args,
+		.encode_res = encode_getattr_res,
+		.res_maxsize = CB_OP_GETATTR_RES_MAXSZ,
+	},
+	[OP_CB_RECALL] = {
+		.process_op = nfs4_callback_recall,
+		.decode_args = decode_recall_args,
+		.res_maxsize = CB_OP_RECALL_RES_MAXSZ,
+	},
+#if defined(CONFIG_NFS_V4_1)
+	[OP_CB_LAYOUTRECALL] = {
+		.process_op = nfs4_callback_layoutrecall,
+		.decode_args = decode_layoutrecall_args,
+		.res_maxsize = CB_OP_LAYOUTRECALL_RES_MAXSZ,
+	},
+	[OP_CB_NOTIFY_DEVICEID] = {
+		.process_op = nfs4_callback_devicenotify,
+		.decode_args = decode_devicenotify_args,
+		.res_maxsize = CB_OP_DEVICENOTIFY_RES_MAXSZ,
+	},
+	[OP_CB_SEQUENCE] = {
+		.process_op = nfs4_callback_sequence,
+		.decode_args = decode_cb_sequence_args,
+		.encode_res = encode_cb_sequence_res,
+		.res_maxsize = CB_OP_SEQUENCE_RES_MAXSZ,
+	},
+	[OP_CB_RECALL_ANY] = {
+		.process_op = nfs4_callback_recallany,
+		.decode_args = decode_recallany_args,
+		.res_maxsize = CB_OP_RECALLANY_RES_MAXSZ,
+	},
+	[OP_CB_RECALL_SLOT] = {
+		.process_op = nfs4_callback_recallslot,
+		.decode_args = decode_recallslot_args,
+		.res_maxsize = CB_OP_RECALLSLOT_RES_MAXSZ,
+	},
+	[OP_CB_NOTIFY_LOCK] = {
+		.process_op = nfs4_callback_notify_lock,
+		.decode_args = decode_notify_lock_args,
+		.res_maxsize = CB_OP_NOTIFY_LOCK_RES_MAXSZ,
+	},
+#endif /* CONFIG_NFS_V4_1 */
+#ifdef CONFIG_NFS_V4_2
+	[OP_CB_OFFLOAD] = {
+		.process_op = nfs4_callback_offload,
+		.decode_args = decode_offload_args,
+		.res_maxsize = CB_OP_OFFLOAD_RES_MAXSZ,
+	},
+#endif /* CONFIG_NFS_V4_2 */
+};
+
+/*
+ * Define NFS4 callback procedures
+ */
+static const struct svc_procedure nfs4_callback_procedures1[] = {
+	[CB_NULL] = {
+		.pc_func = nfs4_callback_null,
+		.pc_decode = nfs4_decode_void,
+		.pc_encode = nfs4_encode_void,
+		.pc_xdrressize = 1,
+	},
+	[CB_COMPOUND] = {
+		.pc_func = nfs4_callback_compound,
+		.pc_encode = nfs4_encode_void,
+		.pc_argsize = 256,
+		.pc_ressize = 256,
+		.pc_xdrressize = NFS4_CALLBACK_BUFSIZE,
+	}
+};
+
+static unsigned int nfs4_callback_count1[ARRAY_SIZE(nfs4_callback_procedures1)];
+const struct svc_version nfs4_callback_version1 = {
+	.vs_vers = 1,
+	.vs_nproc = ARRAY_SIZE(nfs4_callback_procedures1),
+	.vs_proc = nfs4_callback_procedures1,
+	.vs_count = nfs4_callback_count1,
+	.vs_xdrsize = NFS4_CALLBACK_XDRSIZE,
+	.vs_dispatch = NULL,
+	.vs_hidden = true,
+	.vs_need_cong_ctrl = true,
+};
+
+static unsigned int nfs4_callback_count4[ARRAY_SIZE(nfs4_callback_procedures1)];
+const struct svc_version nfs4_callback_version4 = {
+	.vs_vers = 4,
+	.vs_nproc = ARRAY_SIZE(nfs4_callback_procedures1),
+	.vs_proc = nfs4_callback_procedures1,
+	.vs_count = nfs4_callback_count4,
+	.vs_xdrsize = NFS4_CALLBACK_XDRSIZE,
+	.vs_dispatch = NULL,
+	.vs_hidden = true,
+	.vs_need_cong_ctrl = true,
+};
diff --git a/fs/nfs/client.c b/fs/nfs/client.c
new file mode 100644
index 000000000..818ff8b1b
--- /dev/null
+++ b/fs/nfs/client.c
@@ -0,0 +1,1358 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* client.c: NFS client sharing and management code
+ *
+ * Copyright (C) 2006 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/sched.h>
+#include <linux/time.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/string.h>
+#include <linux/stat.h>
+#include <linux/errno.h>
+#include <linux/unistd.h>
+#include <linux/sunrpc/addr.h>
+#include <linux/sunrpc/clnt.h>
+#include <linux/sunrpc/stats.h>
+#include <linux/sunrpc/metrics.h>
+#include <linux/sunrpc/xprtsock.h>
+#include <linux/sunrpc/xprtrdma.h>
+#include <linux/nfs_fs.h>
+#include <linux/nfs_mount.h>
+#include <linux/nfs4_mount.h>
+#include <linux/lockd/bind.h>
+#include <linux/seq_file.h>
+#include <linux/mount.h>
+#include <linux/vfs.h>
+#include <linux/inet.h>
+#include <linux/in6.h>
+#include <linux/slab.h>
+#include <linux/idr.h>
+#include <net/ipv6.h>
+#include <linux/nfs_xdr.h>
+#include <linux/sunrpc/bc_xprt.h>
+#include <linux/nsproxy.h>
+#include <linux/pid_namespace.h>
+
+
+#include "nfs4_fs.h"
+#include "callback.h"
+#include "delegation.h"
+#include "iostat.h"
+#include "internal.h"
+#include "fscache.h"
+#include "pnfs.h"
+#include "nfs.h"
+#include "netns.h"
+#include "sysfs.h"
+#include "nfs42.h"
+
+#define NFSDBG_FACILITY		NFSDBG_CLIENT
+
+static DECLARE_WAIT_QUEUE_HEAD(nfs_client_active_wq);
+static DEFINE_SPINLOCK(nfs_version_lock);
+static DEFINE_MUTEX(nfs_version_mutex);
+static LIST_HEAD(nfs_versions);
+
+/*
+ * RPC cruft for NFS
+ */
+static const struct rpc_version *nfs_version[5] = {
+	[2] = NULL,
+	[3] = NULL,
+	[4] = NULL,
+};
+
+const struct rpc_program nfs_program = {
+	.name			= "nfs",
+	.number			= NFS_PROGRAM,
+	.nrvers			= ARRAY_SIZE(nfs_version),
+	.version		= nfs_version,
+	.stats			= &nfs_rpcstat,
+	.pipe_dir_name		= NFS_PIPE_DIRNAME,
+};
+
+struct rpc_stat nfs_rpcstat = {
+	.program		= &nfs_program
+};
+
+static struct nfs_subversion *find_nfs_version(unsigned int version)
+{
+	struct nfs_subversion *nfs;
+	spin_lock(&nfs_version_lock);
+
+	list_for_each_entry(nfs, &nfs_versions, list) {
+		if (nfs->rpc_ops->version == version) {
+			spin_unlock(&nfs_version_lock);
+			return nfs;
+		}
+	}
+
+	spin_unlock(&nfs_version_lock);
+	return ERR_PTR(-EPROTONOSUPPORT);
+}
+
+struct nfs_subversion *get_nfs_version(unsigned int version)
+{
+	struct nfs_subversion *nfs = find_nfs_version(version);
+
+	if (IS_ERR(nfs)) {
+		mutex_lock(&nfs_version_mutex);
+		request_module("nfsv%d", version);
+		nfs = find_nfs_version(version);
+		mutex_unlock(&nfs_version_mutex);
+	}
+
+	if (!IS_ERR(nfs) && !try_module_get(nfs->owner))
+		return ERR_PTR(-EAGAIN);
+	return nfs;
+}
+
+void put_nfs_version(struct nfs_subversion *nfs)
+{
+	module_put(nfs->owner);
+}
+
+void register_nfs_version(struct nfs_subversion *nfs)
+{
+	spin_lock(&nfs_version_lock);
+
+	list_add(&nfs->list, &nfs_versions);
+	nfs_version[nfs->rpc_ops->version] = nfs->rpc_vers;
+
+	spin_unlock(&nfs_version_lock);
+}
+EXPORT_SYMBOL_GPL(register_nfs_version);
+
+void unregister_nfs_version(struct nfs_subversion *nfs)
+{
+	spin_lock(&nfs_version_lock);
+
+	nfs_version[nfs->rpc_ops->version] = NULL;
+	list_del(&nfs->list);
+
+	spin_unlock(&nfs_version_lock);
+}
+EXPORT_SYMBOL_GPL(unregister_nfs_version);
+
+/*
+ * Allocate a shared client record
+ *
+ * Since these are allocated/deallocated very rarely, we don't
+ * bother putting them in a slab cache...
+ */
+struct nfs_client *nfs_alloc_client(const struct nfs_client_initdata *cl_init)
+{
+	struct nfs_client *clp;
+	int err = -ENOMEM;
+
+	if ((clp = kzalloc(sizeof(*clp), GFP_KERNEL)) == NULL)
+		goto error_0;
+
+	clp->cl_minorversion = cl_init->minorversion;
+	clp->cl_nfs_mod = cl_init->nfs_mod;
+	if (!try_module_get(clp->cl_nfs_mod->owner))
+		goto error_dealloc;
+
+	clp->rpc_ops = clp->cl_nfs_mod->rpc_ops;
+
+	refcount_set(&clp->cl_count, 1);
+	clp->cl_cons_state = NFS_CS_INITING;
+
+	memcpy(&clp->cl_addr, cl_init->addr, cl_init->addrlen);
+	clp->cl_addrlen = cl_init->addrlen;
+
+	if (cl_init->hostname) {
+		err = -ENOMEM;
+		clp->cl_hostname = kstrdup(cl_init->hostname, GFP_KERNEL);
+		if (!clp->cl_hostname)
+			goto error_cleanup;
+	}
+
+	INIT_LIST_HEAD(&clp->cl_superblocks);
+	clp->cl_rpcclient = ERR_PTR(-EINVAL);
+
+	clp->cl_flags = cl_init->init_flags;
+	clp->cl_proto = cl_init->proto;
+	clp->cl_nconnect = cl_init->nconnect;
+	clp->cl_net = get_net(cl_init->net);
+
+	clp->cl_principal = "*";
+	nfs_fscache_get_client_cookie(clp);
+
+	return clp;
+
+error_cleanup:
+	put_nfs_version(clp->cl_nfs_mod);
+error_dealloc:
+	kfree(clp);
+error_0:
+	return ERR_PTR(err);
+}
+EXPORT_SYMBOL_GPL(nfs_alloc_client);
+
+#if IS_ENABLED(CONFIG_NFS_V4)
+static void nfs_cleanup_cb_ident_idr(struct net *net)
+{
+	struct nfs_net *nn = net_generic(net, nfs_net_id);
+
+	idr_destroy(&nn->cb_ident_idr);
+}
+
+/* nfs_client_lock held */
+static void nfs_cb_idr_remove_locked(struct nfs_client *clp)
+{
+	struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
+
+	if (clp->cl_cb_ident)
+		idr_remove(&nn->cb_ident_idr, clp->cl_cb_ident);
+}
+
+static void pnfs_init_server(struct nfs_server *server)
+{
+	rpc_init_wait_queue(&server->roc_rpcwaitq, "pNFS ROC");
+}
+
+#else
+static void nfs_cleanup_cb_ident_idr(struct net *net)
+{
+}
+
+static void nfs_cb_idr_remove_locked(struct nfs_client *clp)
+{
+}
+
+static void pnfs_init_server(struct nfs_server *server)
+{
+}
+
+#endif /* CONFIG_NFS_V4 */
+
+/*
+ * Destroy a shared client record
+ */
+void nfs_free_client(struct nfs_client *clp)
+{
+	nfs_fscache_release_client_cookie(clp);
+
+	/* -EIO all pending I/O */
+	if (!IS_ERR(clp->cl_rpcclient))
+		rpc_shutdown_client(clp->cl_rpcclient);
+
+	put_net(clp->cl_net);
+	put_nfs_version(clp->cl_nfs_mod);
+	kfree(clp->cl_hostname);
+	kfree(clp->cl_acceptor);
+	kfree(clp);
+}
+EXPORT_SYMBOL_GPL(nfs_free_client);
+
+/*
+ * Release a reference to a shared client record
+ */
+void nfs_put_client(struct nfs_client *clp)
+{
+	struct nfs_net *nn;
+
+	if (!clp)
+		return;
+
+	nn = net_generic(clp->cl_net, nfs_net_id);
+
+	if (refcount_dec_and_lock(&clp->cl_count, &nn->nfs_client_lock)) {
+		list_del(&clp->cl_share_link);
+		nfs_cb_idr_remove_locked(clp);
+		spin_unlock(&nn->nfs_client_lock);
+
+		WARN_ON_ONCE(!list_empty(&clp->cl_superblocks));
+
+		clp->rpc_ops->free_client(clp);
+	}
+}
+EXPORT_SYMBOL_GPL(nfs_put_client);
+
+/*
+ * Find an nfs_client on the list that matches the initialisation data
+ * that is supplied.
+ */
+static struct nfs_client *nfs_match_client(const struct nfs_client_initdata *data)
+{
+	struct nfs_client *clp;
+	const struct sockaddr *sap = data->addr;
+	struct nfs_net *nn = net_generic(data->net, nfs_net_id);
+	int error;
+
+again:
+	list_for_each_entry(clp, &nn->nfs_client_list, cl_share_link) {
+	        const struct sockaddr *clap = (struct sockaddr *)&clp->cl_addr;
+		/* Don't match clients that failed to initialise properly */
+		if (clp->cl_cons_state < 0)
+			continue;
+
+		/* If a client is still initializing then we need to wait */
+		if (clp->cl_cons_state > NFS_CS_READY) {
+			refcount_inc(&clp->cl_count);
+			spin_unlock(&nn->nfs_client_lock);
+			error = nfs_wait_client_init_complete(clp);
+			nfs_put_client(clp);
+			spin_lock(&nn->nfs_client_lock);
+			if (error < 0)
+				return ERR_PTR(error);
+			goto again;
+		}
+
+		/* Different NFS versions cannot share the same nfs_client */
+		if (clp->rpc_ops != data->nfs_mod->rpc_ops)
+			continue;
+
+		if (clp->cl_proto != data->proto)
+			continue;
+		/* Match nfsv4 minorversion */
+		if (clp->cl_minorversion != data->minorversion)
+			continue;
+
+		/* Match request for a dedicated DS */
+		if (test_bit(NFS_CS_DS, &data->init_flags) !=
+		    test_bit(NFS_CS_DS, &clp->cl_flags))
+			continue;
+
+		/* Match the full socket address */
+		if (!rpc_cmp_addr_port(sap, clap))
+			/* Match all xprt_switch full socket addresses */
+			if (IS_ERR(clp->cl_rpcclient) ||
+                            !rpc_clnt_xprt_switch_has_addr(clp->cl_rpcclient,
+							   sap))
+				continue;
+
+		refcount_inc(&clp->cl_count);
+		return clp;
+	}
+	return NULL;
+}
+
+/*
+ * Return true if @clp is done initializing, false if still working on it.
+ *
+ * Use nfs_client_init_status to check if it was successful.
+ */
+bool nfs_client_init_is_complete(const struct nfs_client *clp)
+{
+	return clp->cl_cons_state <= NFS_CS_READY;
+}
+EXPORT_SYMBOL_GPL(nfs_client_init_is_complete);
+
+/*
+ * Return 0 if @clp was successfully initialized, -errno otherwise.
+ *
+ * This must be called *after* nfs_client_init_is_complete() returns true,
+ * otherwise it will pop WARN_ON_ONCE and return -EINVAL
+ */
+int nfs_client_init_status(const struct nfs_client *clp)
+{
+	/* called without checking nfs_client_init_is_complete */
+	if (clp->cl_cons_state > NFS_CS_READY) {
+		WARN_ON_ONCE(1);
+		return -EINVAL;
+	}
+	return clp->cl_cons_state;
+}
+EXPORT_SYMBOL_GPL(nfs_client_init_status);
+
+int nfs_wait_client_init_complete(const struct nfs_client *clp)
+{
+	return wait_event_killable(nfs_client_active_wq,
+			nfs_client_init_is_complete(clp));
+}
+EXPORT_SYMBOL_GPL(nfs_wait_client_init_complete);
+
+/*
+ * Found an existing client.  Make sure it's ready before returning.
+ */
+static struct nfs_client *
+nfs_found_client(const struct nfs_client_initdata *cl_init,
+		 struct nfs_client *clp)
+{
+	int error;
+
+	error = nfs_wait_client_init_complete(clp);
+	if (error < 0) {
+		nfs_put_client(clp);
+		return ERR_PTR(-ERESTARTSYS);
+	}
+
+	if (clp->cl_cons_state < NFS_CS_READY) {
+		error = clp->cl_cons_state;
+		nfs_put_client(clp);
+		return ERR_PTR(error);
+	}
+
+	smp_rmb();
+	return clp;
+}
+
+/*
+ * Look up a client by IP address and protocol version
+ * - creates a new record if one doesn't yet exist
+ */
+struct nfs_client *nfs_get_client(const struct nfs_client_initdata *cl_init)
+{
+	struct nfs_client *clp, *new = NULL;
+	struct nfs_net *nn = net_generic(cl_init->net, nfs_net_id);
+	const struct nfs_rpc_ops *rpc_ops = cl_init->nfs_mod->rpc_ops;
+
+	if (cl_init->hostname == NULL) {
+		WARN_ON(1);
+		return ERR_PTR(-EINVAL);
+	}
+
+	/* see if the client already exists */
+	do {
+		spin_lock(&nn->nfs_client_lock);
+
+		clp = nfs_match_client(cl_init);
+		if (clp) {
+			spin_unlock(&nn->nfs_client_lock);
+			if (new)
+				new->rpc_ops->free_client(new);
+			if (IS_ERR(clp))
+				return clp;
+			return nfs_found_client(cl_init, clp);
+		}
+		if (new) {
+			list_add_tail(&new->cl_share_link,
+					&nn->nfs_client_list);
+			spin_unlock(&nn->nfs_client_lock);
+			return rpc_ops->init_client(new, cl_init);
+		}
+
+		spin_unlock(&nn->nfs_client_lock);
+
+		new = rpc_ops->alloc_client(cl_init);
+	} while (!IS_ERR(new));
+
+	return new;
+}
+EXPORT_SYMBOL_GPL(nfs_get_client);
+
+/*
+ * Mark a server as ready or failed
+ */
+void nfs_mark_client_ready(struct nfs_client *clp, int state)
+{
+	smp_wmb();
+	clp->cl_cons_state = state;
+	wake_up_all(&nfs_client_active_wq);
+}
+EXPORT_SYMBOL_GPL(nfs_mark_client_ready);
+
+/*
+ * Initialise the timeout values for a connection
+ */
+void nfs_init_timeout_values(struct rpc_timeout *to, int proto,
+				    int timeo, int retrans)
+{
+	to->to_initval = timeo * HZ / 10;
+	to->to_retries = retrans;
+
+	switch (proto) {
+	case XPRT_TRANSPORT_TCP:
+	case XPRT_TRANSPORT_RDMA:
+		if (retrans == NFS_UNSPEC_RETRANS)
+			to->to_retries = NFS_DEF_TCP_RETRANS;
+		if (timeo == NFS_UNSPEC_TIMEO || to->to_initval == 0)
+			to->to_initval = NFS_DEF_TCP_TIMEO * HZ / 10;
+		if (to->to_initval > NFS_MAX_TCP_TIMEOUT)
+			to->to_initval = NFS_MAX_TCP_TIMEOUT;
+		to->to_increment = to->to_initval;
+		to->to_maxval = to->to_initval + (to->to_increment * to->to_retries);
+		if (to->to_maxval > NFS_MAX_TCP_TIMEOUT)
+			to->to_maxval = NFS_MAX_TCP_TIMEOUT;
+		if (to->to_maxval < to->to_initval)
+			to->to_maxval = to->to_initval;
+		to->to_exponential = 0;
+		break;
+#ifndef CONFIG_NFS_DISABLE_UDP_SUPPORT
+	case XPRT_TRANSPORT_UDP:
+		if (retrans == NFS_UNSPEC_RETRANS)
+			to->to_retries = NFS_DEF_UDP_RETRANS;
+		if (timeo == NFS_UNSPEC_TIMEO || to->to_initval == 0)
+			to->to_initval = NFS_DEF_UDP_TIMEO * HZ / 10;
+		if (to->to_initval > NFS_MAX_UDP_TIMEOUT)
+			to->to_initval = NFS_MAX_UDP_TIMEOUT;
+		to->to_maxval = NFS_MAX_UDP_TIMEOUT;
+		to->to_exponential = 1;
+		break;
+#endif
+	default:
+		BUG();
+	}
+}
+EXPORT_SYMBOL_GPL(nfs_init_timeout_values);
+
+/*
+ * Create an RPC client handle
+ */
+int nfs_create_rpc_client(struct nfs_client *clp,
+			  const struct nfs_client_initdata *cl_init,
+			  rpc_authflavor_t flavor)
+{
+	struct rpc_clnt		*clnt = NULL;
+	struct rpc_create_args args = {
+		.net		= clp->cl_net,
+		.protocol	= clp->cl_proto,
+		.nconnect	= clp->cl_nconnect,
+		.address	= (struct sockaddr *)&clp->cl_addr,
+		.addrsize	= clp->cl_addrlen,
+		.timeout	= cl_init->timeparms,
+		.servername	= clp->cl_hostname,
+		.nodename	= cl_init->nodename,
+		.program	= &nfs_program,
+		.version	= clp->rpc_ops->version,
+		.authflavor	= flavor,
+		.cred		= cl_init->cred,
+	};
+
+	if (test_bit(NFS_CS_DISCRTRY, &clp->cl_flags))
+		args.flags |= RPC_CLNT_CREATE_DISCRTRY;
+	if (test_bit(NFS_CS_NO_RETRANS_TIMEOUT, &clp->cl_flags))
+		args.flags |= RPC_CLNT_CREATE_NO_RETRANS_TIMEOUT;
+	if (test_bit(NFS_CS_NORESVPORT, &clp->cl_flags))
+		args.flags |= RPC_CLNT_CREATE_NONPRIVPORT;
+	if (test_bit(NFS_CS_INFINITE_SLOTS, &clp->cl_flags))
+		args.flags |= RPC_CLNT_CREATE_INFINITE_SLOTS;
+	if (test_bit(NFS_CS_NOPING, &clp->cl_flags))
+		args.flags |= RPC_CLNT_CREATE_NOPING;
+	if (test_bit(NFS_CS_REUSEPORT, &clp->cl_flags))
+		args.flags |= RPC_CLNT_CREATE_REUSEPORT;
+
+	if (!IS_ERR(clp->cl_rpcclient))
+		return 0;
+
+	clnt = rpc_create(&args);
+	if (IS_ERR(clnt)) {
+		dprintk("%s: cannot create RPC client. Error = %ld\n",
+				__func__, PTR_ERR(clnt));
+		return PTR_ERR(clnt);
+	}
+
+	clnt->cl_principal = clp->cl_principal;
+	clp->cl_rpcclient = clnt;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nfs_create_rpc_client);
+
+/*
+ * Version 2 or 3 client destruction
+ */
+static void nfs_destroy_server(struct nfs_server *server)
+{
+	if (server->nlm_host)
+		nlmclnt_done(server->nlm_host);
+}
+
+/*
+ * Version 2 or 3 lockd setup
+ */
+static int nfs_start_lockd(struct nfs_server *server)
+{
+	struct nlm_host *host;
+	struct nfs_client *clp = server->nfs_client;
+	struct nlmclnt_initdata nlm_init = {
+		.hostname	= clp->cl_hostname,
+		.address	= (struct sockaddr *)&clp->cl_addr,
+		.addrlen	= clp->cl_addrlen,
+		.nfs_version	= clp->rpc_ops->version,
+		.noresvport	= server->flags & NFS_MOUNT_NORESVPORT ?
+					1 : 0,
+		.net		= clp->cl_net,
+		.nlmclnt_ops 	= clp->cl_nfs_mod->rpc_ops->nlmclnt_ops,
+		.cred		= current_cred(),
+	};
+
+	if (nlm_init.nfs_version > 3)
+		return 0;
+	if ((server->flags & NFS_MOUNT_LOCAL_FLOCK) &&
+			(server->flags & NFS_MOUNT_LOCAL_FCNTL))
+		return 0;
+
+	switch (clp->cl_proto) {
+		default:
+			nlm_init.protocol = IPPROTO_TCP;
+			break;
+#ifndef CONFIG_NFS_DISABLE_UDP_SUPPORT
+		case XPRT_TRANSPORT_UDP:
+			nlm_init.protocol = IPPROTO_UDP;
+#endif
+	}
+
+	host = nlmclnt_init(&nlm_init);
+	if (IS_ERR(host))
+		return PTR_ERR(host);
+
+	server->nlm_host = host;
+	server->destroy = nfs_destroy_server;
+	return 0;
+}
+
+/*
+ * Create a general RPC client
+ */
+int nfs_init_server_rpcclient(struct nfs_server *server,
+		const struct rpc_timeout *timeo,
+		rpc_authflavor_t pseudoflavour)
+{
+	struct nfs_client *clp = server->nfs_client;
+
+	server->client = rpc_clone_client_set_auth(clp->cl_rpcclient,
+							pseudoflavour);
+	if (IS_ERR(server->client)) {
+		dprintk("%s: couldn't create rpc_client!\n", __func__);
+		return PTR_ERR(server->client);
+	}
+
+	memcpy(&server->client->cl_timeout_default,
+			timeo,
+			sizeof(server->client->cl_timeout_default));
+	server->client->cl_timeout = &server->client->cl_timeout_default;
+	server->client->cl_softrtry = 0;
+	if (server->flags & NFS_MOUNT_SOFTERR)
+		server->client->cl_softerr = 1;
+	if (server->flags & NFS_MOUNT_SOFT)
+		server->client->cl_softrtry = 1;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nfs_init_server_rpcclient);
+
+/**
+ * nfs_init_client - Initialise an NFS2 or NFS3 client
+ *
+ * @clp: nfs_client to initialise
+ * @cl_init: Initialisation parameters
+ *
+ * Returns pointer to an NFS client, or an ERR_PTR value.
+ */
+struct nfs_client *nfs_init_client(struct nfs_client *clp,
+				   const struct nfs_client_initdata *cl_init)
+{
+	int error;
+
+	/* the client is already initialised */
+	if (clp->cl_cons_state == NFS_CS_READY)
+		return clp;
+
+	/*
+	 * Create a client RPC handle for doing FSSTAT with UNIX auth only
+	 * - RFC 2623, sec 2.3.2
+	 */
+	error = nfs_create_rpc_client(clp, cl_init, RPC_AUTH_UNIX);
+	nfs_mark_client_ready(clp, error == 0 ? NFS_CS_READY : error);
+	if (error < 0) {
+		nfs_put_client(clp);
+		clp = ERR_PTR(error);
+	}
+	return clp;
+}
+EXPORT_SYMBOL_GPL(nfs_init_client);
+
+/*
+ * Create a version 2 or 3 client
+ */
+static int nfs_init_server(struct nfs_server *server,
+			   const struct fs_context *fc)
+{
+	const struct nfs_fs_context *ctx = nfs_fc2context(fc);
+	struct rpc_timeout timeparms;
+	struct nfs_client_initdata cl_init = {
+		.hostname = ctx->nfs_server.hostname,
+		.addr = (const struct sockaddr *)&ctx->nfs_server.address,
+		.addrlen = ctx->nfs_server.addrlen,
+		.nfs_mod = ctx->nfs_mod,
+		.proto = ctx->nfs_server.protocol,
+		.net = fc->net_ns,
+		.timeparms = &timeparms,
+		.cred = server->cred,
+		.nconnect = ctx->nfs_server.nconnect,
+		.init_flags = (1UL << NFS_CS_REUSEPORT),
+	};
+	struct nfs_client *clp;
+	int error;
+
+	nfs_init_timeout_values(&timeparms, ctx->nfs_server.protocol,
+				ctx->timeo, ctx->retrans);
+	if (ctx->flags & NFS_MOUNT_NORESVPORT)
+		set_bit(NFS_CS_NORESVPORT, &cl_init.init_flags);
+
+	/* Allocate or find a client reference we can use */
+	clp = nfs_get_client(&cl_init);
+	if (IS_ERR(clp))
+		return PTR_ERR(clp);
+
+	server->nfs_client = clp;
+
+	/* Initialise the client representation from the mount data */
+	server->flags = ctx->flags;
+	server->options = ctx->options;
+	server->caps |= NFS_CAP_HARDLINKS|NFS_CAP_SYMLINKS|NFS_CAP_FILEID|
+		NFS_CAP_MODE|NFS_CAP_NLINK|NFS_CAP_OWNER|NFS_CAP_OWNER_GROUP|
+		NFS_CAP_ATIME|NFS_CAP_CTIME|NFS_CAP_MTIME;
+
+	if (ctx->rsize)
+		server->rsize = nfs_block_size(ctx->rsize, NULL);
+	if (ctx->wsize)
+		server->wsize = nfs_block_size(ctx->wsize, NULL);
+
+	server->acregmin = ctx->acregmin * HZ;
+	server->acregmax = ctx->acregmax * HZ;
+	server->acdirmin = ctx->acdirmin * HZ;
+	server->acdirmax = ctx->acdirmax * HZ;
+
+	/* Start lockd here, before we might error out */
+	error = nfs_start_lockd(server);
+	if (error < 0)
+		goto error;
+
+	server->port = ctx->nfs_server.port;
+	server->auth_info = ctx->auth_info;
+
+	error = nfs_init_server_rpcclient(server, &timeparms,
+					  ctx->selected_flavor);
+	if (error < 0)
+		goto error;
+
+	/* Preserve the values of mount_server-related mount options */
+	if (ctx->mount_server.addrlen) {
+		memcpy(&server->mountd_address, &ctx->mount_server.address,
+			ctx->mount_server.addrlen);
+		server->mountd_addrlen = ctx->mount_server.addrlen;
+	}
+	server->mountd_version = ctx->mount_server.version;
+	server->mountd_port = ctx->mount_server.port;
+	server->mountd_protocol = ctx->mount_server.protocol;
+
+	server->namelen  = ctx->namlen;
+	return 0;
+
+error:
+	server->nfs_client = NULL;
+	nfs_put_client(clp);
+	return error;
+}
+
+/*
+ * Load up the server record from information gained in an fsinfo record
+ */
+static void nfs_server_set_fsinfo(struct nfs_server *server,
+				  struct nfs_fsinfo *fsinfo)
+{
+	unsigned long max_rpc_payload, raw_max_rpc_payload;
+
+	/* Work out a lot of parameters */
+	if (server->rsize == 0)
+		server->rsize = nfs_block_size(fsinfo->rtpref, NULL);
+	if (server->wsize == 0)
+		server->wsize = nfs_block_size(fsinfo->wtpref, NULL);
+
+	if (fsinfo->rtmax >= 512 && server->rsize > fsinfo->rtmax)
+		server->rsize = nfs_block_size(fsinfo->rtmax, NULL);
+	if (fsinfo->wtmax >= 512 && server->wsize > fsinfo->wtmax)
+		server->wsize = nfs_block_size(fsinfo->wtmax, NULL);
+
+	raw_max_rpc_payload = rpc_max_payload(server->client);
+	max_rpc_payload = nfs_block_size(raw_max_rpc_payload, NULL);
+
+	if (server->rsize > max_rpc_payload)
+		server->rsize = max_rpc_payload;
+	if (server->rsize > NFS_MAX_FILE_IO_SIZE)
+		server->rsize = NFS_MAX_FILE_IO_SIZE;
+	server->rpages = (server->rsize + PAGE_SIZE - 1) >> PAGE_SHIFT;
+
+	if (server->wsize > max_rpc_payload)
+		server->wsize = max_rpc_payload;
+	if (server->wsize > NFS_MAX_FILE_IO_SIZE)
+		server->wsize = NFS_MAX_FILE_IO_SIZE;
+	server->wpages = (server->wsize + PAGE_SIZE - 1) >> PAGE_SHIFT;
+
+	server->wtmult = nfs_block_bits(fsinfo->wtmult, NULL);
+
+	server->dtsize = nfs_block_size(fsinfo->dtpref, NULL);
+	if (server->dtsize > PAGE_SIZE * NFS_MAX_READDIR_PAGES)
+		server->dtsize = PAGE_SIZE * NFS_MAX_READDIR_PAGES;
+	if (server->dtsize > server->rsize)
+		server->dtsize = server->rsize;
+
+	if (server->flags & NFS_MOUNT_NOAC) {
+		server->acregmin = server->acregmax = 0;
+		server->acdirmin = server->acdirmax = 0;
+	}
+
+	server->maxfilesize = fsinfo->maxfilesize;
+
+	server->time_delta = fsinfo->time_delta;
+
+	server->clone_blksize = fsinfo->clone_blksize;
+	/* We're airborne Set socket buffersize */
+	rpc_setbufsize(server->client, server->wsize + 100, server->rsize + 100);
+
+#ifdef CONFIG_NFS_V4_2
+	/*
+	 * Defaults until limited by the session parameters.
+	 */
+	server->gxasize = min_t(unsigned int, raw_max_rpc_payload,
+				XATTR_SIZE_MAX);
+	server->sxasize = min_t(unsigned int, raw_max_rpc_payload,
+				XATTR_SIZE_MAX);
+	server->lxasize = min_t(unsigned int, raw_max_rpc_payload,
+				nfs42_listxattr_xdrsize(XATTR_LIST_MAX));
+
+	if (fsinfo->xattr_support)
+		server->caps |= NFS_CAP_XATTR;
+#endif
+}
+
+/*
+ * Probe filesystem information, including the FSID on v2/v3
+ */
+int nfs_probe_fsinfo(struct nfs_server *server, struct nfs_fh *mntfh, struct nfs_fattr *fattr)
+{
+	struct nfs_fsinfo fsinfo;
+	struct nfs_client *clp = server->nfs_client;
+	int error;
+
+	if (clp->rpc_ops->set_capabilities != NULL) {
+		error = clp->rpc_ops->set_capabilities(server, mntfh);
+		if (error < 0)
+			return error;
+	}
+
+	fsinfo.fattr = fattr;
+	fsinfo.nlayouttypes = 0;
+	memset(fsinfo.layouttype, 0, sizeof(fsinfo.layouttype));
+	error = clp->rpc_ops->fsinfo(server, mntfh, &fsinfo);
+	if (error < 0)
+		return error;
+
+	nfs_server_set_fsinfo(server, &fsinfo);
+
+	/* Get some general file system info */
+	if (server->namelen == 0) {
+		struct nfs_pathconf pathinfo;
+
+		pathinfo.fattr = fattr;
+		nfs_fattr_init(fattr);
+
+		if (clp->rpc_ops->pathconf(server, mntfh, &pathinfo) >= 0)
+			server->namelen = pathinfo.max_namelen;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nfs_probe_fsinfo);
+
+/*
+ * Copy useful information when duplicating a server record
+ */
+void nfs_server_copy_userdata(struct nfs_server *target, struct nfs_server *source)
+{
+	target->flags = source->flags;
+	target->rsize = source->rsize;
+	target->wsize = source->wsize;
+	target->acregmin = source->acregmin;
+	target->acregmax = source->acregmax;
+	target->acdirmin = source->acdirmin;
+	target->acdirmax = source->acdirmax;
+	target->caps = source->caps;
+	target->options = source->options;
+	target->auth_info = source->auth_info;
+	target->port = source->port;
+}
+EXPORT_SYMBOL_GPL(nfs_server_copy_userdata);
+
+void nfs_server_insert_lists(struct nfs_server *server)
+{
+	struct nfs_client *clp = server->nfs_client;
+	struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
+
+	spin_lock(&nn->nfs_client_lock);
+	list_add_tail_rcu(&server->client_link, &clp->cl_superblocks);
+	list_add_tail(&server->master_link, &nn->nfs_volume_list);
+	clear_bit(NFS_CS_STOP_RENEW, &clp->cl_res_state);
+	spin_unlock(&nn->nfs_client_lock);
+
+}
+EXPORT_SYMBOL_GPL(nfs_server_insert_lists);
+
+void nfs_server_remove_lists(struct nfs_server *server)
+{
+	struct nfs_client *clp = server->nfs_client;
+	struct nfs_net *nn;
+
+	if (clp == NULL)
+		return;
+	nn = net_generic(clp->cl_net, nfs_net_id);
+	spin_lock(&nn->nfs_client_lock);
+	list_del_rcu(&server->client_link);
+	if (list_empty(&clp->cl_superblocks))
+		set_bit(NFS_CS_STOP_RENEW, &clp->cl_res_state);
+	list_del(&server->master_link);
+	spin_unlock(&nn->nfs_client_lock);
+
+	synchronize_rcu();
+}
+EXPORT_SYMBOL_GPL(nfs_server_remove_lists);
+
+/*
+ * Allocate and initialise a server record
+ */
+struct nfs_server *nfs_alloc_server(void)
+{
+	struct nfs_server *server;
+
+	server = kzalloc(sizeof(struct nfs_server), GFP_KERNEL);
+	if (!server)
+		return NULL;
+
+	server->client = server->client_acl = ERR_PTR(-EINVAL);
+
+	/* Zero out the NFS state stuff */
+	INIT_LIST_HEAD(&server->client_link);
+	INIT_LIST_HEAD(&server->master_link);
+	INIT_LIST_HEAD(&server->delegations);
+	INIT_LIST_HEAD(&server->layouts);
+	INIT_LIST_HEAD(&server->state_owners_lru);
+	INIT_LIST_HEAD(&server->ss_copies);
+
+	atomic_set(&server->active, 0);
+
+	server->io_stats = nfs_alloc_iostats();
+	if (!server->io_stats) {
+		kfree(server);
+		return NULL;
+	}
+
+	ida_init(&server->openowner_id);
+	ida_init(&server->lockowner_id);
+	pnfs_init_server(server);
+	rpc_init_wait_queue(&server->uoc_rpcwaitq, "NFS UOC");
+
+	return server;
+}
+EXPORT_SYMBOL_GPL(nfs_alloc_server);
+
+/*
+ * Free up a server record
+ */
+void nfs_free_server(struct nfs_server *server)
+{
+	nfs_server_remove_lists(server);
+
+	if (server->destroy != NULL)
+		server->destroy(server);
+
+	if (!IS_ERR(server->client_acl))
+		rpc_shutdown_client(server->client_acl);
+	if (!IS_ERR(server->client))
+		rpc_shutdown_client(server->client);
+
+	nfs_put_client(server->nfs_client);
+
+	ida_destroy(&server->lockowner_id);
+	ida_destroy(&server->openowner_id);
+	nfs_free_iostats(server->io_stats);
+	put_cred(server->cred);
+	kfree(server);
+	nfs_release_automount_timer();
+}
+EXPORT_SYMBOL_GPL(nfs_free_server);
+
+/*
+ * Create a version 2 or 3 volume record
+ * - keyed on server and FSID
+ */
+struct nfs_server *nfs_create_server(struct fs_context *fc)
+{
+	struct nfs_fs_context *ctx = nfs_fc2context(fc);
+	struct nfs_server *server;
+	struct nfs_fattr *fattr;
+	int error;
+
+	server = nfs_alloc_server();
+	if (!server)
+		return ERR_PTR(-ENOMEM);
+
+	server->cred = get_cred(current_cred());
+
+	error = -ENOMEM;
+	fattr = nfs_alloc_fattr();
+	if (fattr == NULL)
+		goto error;
+
+	/* Get a client representation */
+	error = nfs_init_server(server, fc);
+	if (error < 0)
+		goto error;
+
+	/* Probe the root fh to retrieve its FSID */
+	error = nfs_probe_fsinfo(server, ctx->mntfh, fattr);
+	if (error < 0)
+		goto error;
+	if (server->nfs_client->rpc_ops->version == 3) {
+		if (server->namelen == 0 || server->namelen > NFS3_MAXNAMLEN)
+			server->namelen = NFS3_MAXNAMLEN;
+		if (!(ctx->flags & NFS_MOUNT_NORDIRPLUS))
+			server->caps |= NFS_CAP_READDIRPLUS;
+	} else {
+		if (server->namelen == 0 || server->namelen > NFS2_MAXNAMLEN)
+			server->namelen = NFS2_MAXNAMLEN;
+	}
+
+	if (!(fattr->valid & NFS_ATTR_FATTR)) {
+		error = ctx->nfs_mod->rpc_ops->getattr(server, ctx->mntfh,
+						       fattr, NULL, NULL);
+		if (error < 0) {
+			dprintk("nfs_create_server: getattr error = %d\n", -error);
+			goto error;
+		}
+	}
+	memcpy(&server->fsid, &fattr->fsid, sizeof(server->fsid));
+
+	dprintk("Server FSID: %llx:%llx\n",
+		(unsigned long long) server->fsid.major,
+		(unsigned long long) server->fsid.minor);
+
+	nfs_server_insert_lists(server);
+	server->mount_time = jiffies;
+	nfs_free_fattr(fattr);
+	return server;
+
+error:
+	nfs_free_fattr(fattr);
+	nfs_free_server(server);
+	return ERR_PTR(error);
+}
+EXPORT_SYMBOL_GPL(nfs_create_server);
+
+/*
+ * Clone an NFS2, NFS3 or NFS4 server record
+ */
+struct nfs_server *nfs_clone_server(struct nfs_server *source,
+				    struct nfs_fh *fh,
+				    struct nfs_fattr *fattr,
+				    rpc_authflavor_t flavor)
+{
+	struct nfs_server *server;
+	struct nfs_fattr *fattr_fsinfo;
+	int error;
+
+	server = nfs_alloc_server();
+	if (!server)
+		return ERR_PTR(-ENOMEM);
+
+	server->cred = get_cred(source->cred);
+
+	error = -ENOMEM;
+	fattr_fsinfo = nfs_alloc_fattr();
+	if (fattr_fsinfo == NULL)
+		goto out_free_server;
+
+	/* Copy data from the source */
+	server->nfs_client = source->nfs_client;
+	server->destroy = source->destroy;
+	refcount_inc(&server->nfs_client->cl_count);
+	nfs_server_copy_userdata(server, source);
+
+	server->fsid = fattr->fsid;
+
+	error = nfs_init_server_rpcclient(server,
+			source->client->cl_timeout,
+			flavor);
+	if (error < 0)
+		goto out_free_server;
+
+	/* probe the filesystem info for this server filesystem */
+	error = nfs_probe_fsinfo(server, fh, fattr_fsinfo);
+	if (error < 0)
+		goto out_free_server;
+
+	if (server->namelen == 0 || server->namelen > NFS4_MAXNAMLEN)
+		server->namelen = NFS4_MAXNAMLEN;
+
+	error = nfs_start_lockd(server);
+	if (error < 0)
+		goto out_free_server;
+
+	nfs_server_insert_lists(server);
+	server->mount_time = jiffies;
+
+	nfs_free_fattr(fattr_fsinfo);
+	return server;
+
+out_free_server:
+	nfs_free_fattr(fattr_fsinfo);
+	nfs_free_server(server);
+	return ERR_PTR(error);
+}
+EXPORT_SYMBOL_GPL(nfs_clone_server);
+
+void nfs_clients_init(struct net *net)
+{
+	struct nfs_net *nn = net_generic(net, nfs_net_id);
+
+	INIT_LIST_HEAD(&nn->nfs_client_list);
+	INIT_LIST_HEAD(&nn->nfs_volume_list);
+#if IS_ENABLED(CONFIG_NFS_V4)
+	idr_init(&nn->cb_ident_idr);
+#endif
+	spin_lock_init(&nn->nfs_client_lock);
+	nn->boot_time = ktime_get_real();
+
+	nfs_netns_sysfs_setup(nn, net);
+}
+
+void nfs_clients_exit(struct net *net)
+{
+	struct nfs_net *nn = net_generic(net, nfs_net_id);
+
+	nfs_netns_sysfs_destroy(nn);
+	nfs_cleanup_cb_ident_idr(net);
+	WARN_ON_ONCE(!list_empty(&nn->nfs_client_list));
+	WARN_ON_ONCE(!list_empty(&nn->nfs_volume_list));
+}
+
+#ifdef CONFIG_PROC_FS
+static void *nfs_server_list_start(struct seq_file *p, loff_t *pos);
+static void *nfs_server_list_next(struct seq_file *p, void *v, loff_t *pos);
+static void nfs_server_list_stop(struct seq_file *p, void *v);
+static int nfs_server_list_show(struct seq_file *m, void *v);
+
+static const struct seq_operations nfs_server_list_ops = {
+	.start	= nfs_server_list_start,
+	.next	= nfs_server_list_next,
+	.stop	= nfs_server_list_stop,
+	.show	= nfs_server_list_show,
+};
+
+static void *nfs_volume_list_start(struct seq_file *p, loff_t *pos);
+static void *nfs_volume_list_next(struct seq_file *p, void *v, loff_t *pos);
+static void nfs_volume_list_stop(struct seq_file *p, void *v);
+static int nfs_volume_list_show(struct seq_file *m, void *v);
+
+static const struct seq_operations nfs_volume_list_ops = {
+	.start	= nfs_volume_list_start,
+	.next	= nfs_volume_list_next,
+	.stop	= nfs_volume_list_stop,
+	.show	= nfs_volume_list_show,
+};
+
+/*
+ * set up the iterator to start reading from the server list and return the first item
+ */
+static void *nfs_server_list_start(struct seq_file *m, loff_t *_pos)
+				__acquires(&nn->nfs_client_lock)
+{
+	struct nfs_net *nn = net_generic(seq_file_net(m), nfs_net_id);
+
+	/* lock the list against modification */
+	spin_lock(&nn->nfs_client_lock);
+	return seq_list_start_head(&nn->nfs_client_list, *_pos);
+}
+
+/*
+ * move to next server
+ */
+static void *nfs_server_list_next(struct seq_file *p, void *v, loff_t *pos)
+{
+	struct nfs_net *nn = net_generic(seq_file_net(p), nfs_net_id);
+
+	return seq_list_next(v, &nn->nfs_client_list, pos);
+}
+
+/*
+ * clean up after reading from the transports list
+ */
+static void nfs_server_list_stop(struct seq_file *p, void *v)
+				__releases(&nn->nfs_client_lock)
+{
+	struct nfs_net *nn = net_generic(seq_file_net(p), nfs_net_id);
+
+	spin_unlock(&nn->nfs_client_lock);
+}
+
+/*
+ * display a header line followed by a load of call lines
+ */
+static int nfs_server_list_show(struct seq_file *m, void *v)
+{
+	struct nfs_client *clp;
+	struct nfs_net *nn = net_generic(seq_file_net(m), nfs_net_id);
+
+	/* display header on line 1 */
+	if (v == &nn->nfs_client_list) {
+		seq_puts(m, "NV SERVER   PORT USE HOSTNAME\n");
+		return 0;
+	}
+
+	/* display one transport per line on subsequent lines */
+	clp = list_entry(v, struct nfs_client, cl_share_link);
+
+	/* Check if the client is initialized */
+	if (clp->cl_cons_state != NFS_CS_READY)
+		return 0;
+
+	rcu_read_lock();
+	seq_printf(m, "v%u %s %s %3d %s\n",
+		   clp->rpc_ops->version,
+		   rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_ADDR),
+		   rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_PORT),
+		   refcount_read(&clp->cl_count),
+		   clp->cl_hostname);
+	rcu_read_unlock();
+
+	return 0;
+}
+
+/*
+ * set up the iterator to start reading from the volume list and return the first item
+ */
+static void *nfs_volume_list_start(struct seq_file *m, loff_t *_pos)
+				__acquires(&nn->nfs_client_lock)
+{
+	struct nfs_net *nn = net_generic(seq_file_net(m), nfs_net_id);
+
+	/* lock the list against modification */
+	spin_lock(&nn->nfs_client_lock);
+	return seq_list_start_head(&nn->nfs_volume_list, *_pos);
+}
+
+/*
+ * move to next volume
+ */
+static void *nfs_volume_list_next(struct seq_file *p, void *v, loff_t *pos)
+{
+	struct nfs_net *nn = net_generic(seq_file_net(p), nfs_net_id);
+
+	return seq_list_next(v, &nn->nfs_volume_list, pos);
+}
+
+/*
+ * clean up after reading from the transports list
+ */
+static void nfs_volume_list_stop(struct seq_file *p, void *v)
+				__releases(&nn->nfs_client_lock)
+{
+	struct nfs_net *nn = net_generic(seq_file_net(p), nfs_net_id);
+
+	spin_unlock(&nn->nfs_client_lock);
+}
+
+/*
+ * display a header line followed by a load of call lines
+ */
+static int nfs_volume_list_show(struct seq_file *m, void *v)
+{
+	struct nfs_server *server;
+	struct nfs_client *clp;
+	char dev[13];	// 8 for 2^24, 1 for ':', 3 for 2^8, 1 for '\0'
+	char fsid[34];	// 2 * 16 for %llx, 1 for ':', 1 for '\0'
+	struct nfs_net *nn = net_generic(seq_file_net(m), nfs_net_id);
+
+	/* display header on line 1 */
+	if (v == &nn->nfs_volume_list) {
+		seq_puts(m, "NV SERVER   PORT DEV          FSID"
+			    "                              FSC\n");
+		return 0;
+	}
+	/* display one transport per line on subsequent lines */
+	server = list_entry(v, struct nfs_server, master_link);
+	clp = server->nfs_client;
+
+	snprintf(dev, sizeof(dev), "%u:%u",
+		 MAJOR(server->s_dev), MINOR(server->s_dev));
+
+	snprintf(fsid, sizeof(fsid), "%llx:%llx",
+		 (unsigned long long) server->fsid.major,
+		 (unsigned long long) server->fsid.minor);
+
+	rcu_read_lock();
+	seq_printf(m, "v%u %s %s %-12s %-33s %s\n",
+		   clp->rpc_ops->version,
+		   rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_ADDR),
+		   rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_PORT),
+		   dev,
+		   fsid,
+		   nfs_server_fscache_state(server));
+	rcu_read_unlock();
+
+	return 0;
+}
+
+int nfs_fs_proc_net_init(struct net *net)
+{
+	struct nfs_net *nn = net_generic(net, nfs_net_id);
+	struct proc_dir_entry *p;
+
+	nn->proc_nfsfs = proc_net_mkdir(net, "nfsfs", net->proc_net);
+	if (!nn->proc_nfsfs)
+		goto error_0;
+
+	/* a file of servers with which we're dealing */
+	p = proc_create_net("servers", S_IFREG|S_IRUGO, nn->proc_nfsfs,
+			&nfs_server_list_ops, sizeof(struct seq_net_private));
+	if (!p)
+		goto error_1;
+
+	/* a file of volumes that we have mounted */
+	p = proc_create_net("volumes", S_IFREG|S_IRUGO, nn->proc_nfsfs,
+			&nfs_volume_list_ops, sizeof(struct seq_net_private));
+	if (!p)
+		goto error_1;
+	return 0;
+
+error_1:
+	remove_proc_subtree("nfsfs", net->proc_net);
+error_0:
+	return -ENOMEM;
+}
+
+void nfs_fs_proc_net_exit(struct net *net)
+{
+	remove_proc_subtree("nfsfs", net->proc_net);
+}
+
+/*
+ * initialise the /proc/fs/nfsfs/ directory
+ */
+int __init nfs_fs_proc_init(void)
+{
+	if (!proc_mkdir("fs/nfsfs", NULL))
+		goto error_0;
+
+	/* a file of servers with which we're dealing */
+	if (!proc_symlink("fs/nfsfs/servers", NULL, "../../net/nfsfs/servers"))
+		goto error_1;
+
+	/* a file of volumes that we have mounted */
+	if (!proc_symlink("fs/nfsfs/volumes", NULL, "../../net/nfsfs/volumes"))
+		goto error_1;
+
+	return 0;
+error_1:
+	remove_proc_subtree("fs/nfsfs", NULL);
+error_0:
+	return -ENOMEM;
+}
+
+/*
+ * clean up the /proc/fs/nfsfs/ directory
+ */
+void nfs_fs_proc_exit(void)
+{
+	remove_proc_subtree("fs/nfsfs", NULL);
+}
+
+#endif /* CONFIG_PROC_FS */
diff --git a/fs/nfs/delegation.c b/fs/nfs/delegation.c
new file mode 100644
index 000000000..1eb6c7a14
--- /dev/null
+++ b/fs/nfs/delegation.c
@@ -0,0 +1,1455 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * linux/fs/nfs/delegation.c
+ *
+ * Copyright (C) 2004 Trond Myklebust
+ *
+ * NFS file delegation management
+ *
+ */
+#include <linux/completion.h>
+#include <linux/kthread.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/iversion.h>
+
+#include <linux/nfs4.h>
+#include <linux/nfs_fs.h>
+#include <linux/nfs_xdr.h>
+
+#include "nfs4_fs.h"
+#include "nfs4session.h"
+#include "delegation.h"
+#include "internal.h"
+#include "nfs4trace.h"
+
+#define NFS_DEFAULT_DELEGATION_WATERMARK (5000U)
+
+static atomic_long_t nfs_active_delegations;
+static unsigned nfs_delegation_watermark = NFS_DEFAULT_DELEGATION_WATERMARK;
+
+static void __nfs_free_delegation(struct nfs_delegation *delegation)
+{
+	put_cred(delegation->cred);
+	delegation->cred = NULL;
+	kfree_rcu(delegation, rcu);
+}
+
+static void nfs_mark_delegation_revoked(struct nfs_delegation *delegation)
+{
+	if (!test_and_set_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) {
+		delegation->stateid.type = NFS4_INVALID_STATEID_TYPE;
+		atomic_long_dec(&nfs_active_delegations);
+		if (!test_bit(NFS_DELEGATION_RETURNING, &delegation->flags))
+			nfs_clear_verifier_delegated(delegation->inode);
+	}
+}
+
+static struct nfs_delegation *nfs_get_delegation(struct nfs_delegation *delegation)
+{
+	refcount_inc(&delegation->refcount);
+	return delegation;
+}
+
+static void nfs_put_delegation(struct nfs_delegation *delegation)
+{
+	if (refcount_dec_and_test(&delegation->refcount))
+		__nfs_free_delegation(delegation);
+}
+
+static void nfs_free_delegation(struct nfs_delegation *delegation)
+{
+	nfs_mark_delegation_revoked(delegation);
+	nfs_put_delegation(delegation);
+}
+
+/**
+ * nfs_mark_delegation_referenced - set delegation's REFERENCED flag
+ * @delegation: delegation to process
+ *
+ */
+void nfs_mark_delegation_referenced(struct nfs_delegation *delegation)
+{
+	set_bit(NFS_DELEGATION_REFERENCED, &delegation->flags);
+}
+
+static void nfs_mark_return_delegation(struct nfs_server *server,
+				       struct nfs_delegation *delegation)
+{
+	set_bit(NFS_DELEGATION_RETURN, &delegation->flags);
+	set_bit(NFS4CLNT_DELEGRETURN, &server->nfs_client->cl_state);
+}
+
+static bool
+nfs4_is_valid_delegation(const struct nfs_delegation *delegation,
+		fmode_t flags)
+{
+	if (delegation != NULL && (delegation->type & flags) == flags &&
+	    !test_bit(NFS_DELEGATION_REVOKED, &delegation->flags) &&
+	    !test_bit(NFS_DELEGATION_RETURNING, &delegation->flags))
+		return true;
+	return false;
+}
+
+struct nfs_delegation *nfs4_get_valid_delegation(const struct inode *inode)
+{
+	struct nfs_delegation *delegation;
+
+	delegation = rcu_dereference(NFS_I(inode)->delegation);
+	if (nfs4_is_valid_delegation(delegation, 0))
+		return delegation;
+	return NULL;
+}
+
+static int
+nfs4_do_check_delegation(struct inode *inode, fmode_t flags, bool mark)
+{
+	struct nfs_delegation *delegation;
+	int ret = 0;
+
+	flags &= FMODE_READ|FMODE_WRITE;
+	rcu_read_lock();
+	delegation = rcu_dereference(NFS_I(inode)->delegation);
+	if (nfs4_is_valid_delegation(delegation, flags)) {
+		if (mark)
+			nfs_mark_delegation_referenced(delegation);
+		ret = 1;
+	}
+	rcu_read_unlock();
+	return ret;
+}
+/**
+ * nfs_have_delegation - check if inode has a delegation, mark it
+ * NFS_DELEGATION_REFERENCED if there is one.
+ * @inode: inode to check
+ * @flags: delegation types to check for
+ *
+ * Returns one if inode has the indicated delegation, otherwise zero.
+ */
+int nfs4_have_delegation(struct inode *inode, fmode_t flags)
+{
+	return nfs4_do_check_delegation(inode, flags, true);
+}
+
+/*
+ * nfs4_check_delegation - check if inode has a delegation, do not mark
+ * NFS_DELEGATION_REFERENCED if it has one.
+ */
+int nfs4_check_delegation(struct inode *inode, fmode_t flags)
+{
+	return nfs4_do_check_delegation(inode, flags, false);
+}
+
+static int nfs_delegation_claim_locks(struct nfs4_state *state, const nfs4_stateid *stateid)
+{
+	struct inode *inode = state->inode;
+	struct file_lock *fl;
+	struct file_lock_context *flctx = inode->i_flctx;
+	struct list_head *list;
+	int status = 0;
+
+	if (flctx == NULL)
+		goto out;
+
+	list = &flctx->flc_posix;
+	spin_lock(&flctx->flc_lock);
+restart:
+	list_for_each_entry(fl, list, fl_list) {
+		if (nfs_file_open_context(fl->fl_file)->state != state)
+			continue;
+		spin_unlock(&flctx->flc_lock);
+		status = nfs4_lock_delegation_recall(fl, state, stateid);
+		if (status < 0)
+			goto out;
+		spin_lock(&flctx->flc_lock);
+	}
+	if (list == &flctx->flc_posix) {
+		list = &flctx->flc_flock;
+		goto restart;
+	}
+	spin_unlock(&flctx->flc_lock);
+out:
+	return status;
+}
+
+static int nfs_delegation_claim_opens(struct inode *inode,
+		const nfs4_stateid *stateid, fmode_t type)
+{
+	struct nfs_inode *nfsi = NFS_I(inode);
+	struct nfs_open_context *ctx;
+	struct nfs4_state_owner *sp;
+	struct nfs4_state *state;
+	unsigned int seq;
+	int err;
+
+again:
+	rcu_read_lock();
+	list_for_each_entry_rcu(ctx, &nfsi->open_files, list) {
+		state = ctx->state;
+		if (state == NULL)
+			continue;
+		if (!test_bit(NFS_DELEGATED_STATE, &state->flags))
+			continue;
+		if (!nfs4_valid_open_stateid(state))
+			continue;
+		if (!nfs4_stateid_match(&state->stateid, stateid))
+			continue;
+		if (!get_nfs_open_context(ctx))
+			continue;
+		rcu_read_unlock();
+		sp = state->owner;
+		/* Block nfs4_proc_unlck */
+		mutex_lock(&sp->so_delegreturn_mutex);
+		seq = raw_seqcount_begin(&sp->so_reclaim_seqcount);
+		err = nfs4_open_delegation_recall(ctx, state, stateid);
+		if (!err)
+			err = nfs_delegation_claim_locks(state, stateid);
+		if (!err && read_seqcount_retry(&sp->so_reclaim_seqcount, seq))
+			err = -EAGAIN;
+		mutex_unlock(&sp->so_delegreturn_mutex);
+		put_nfs_open_context(ctx);
+		if (err != 0)
+			return err;
+		goto again;
+	}
+	rcu_read_unlock();
+	return 0;
+}
+
+/**
+ * nfs_inode_reclaim_delegation - process a delegation reclaim request
+ * @inode: inode to process
+ * @cred: credential to use for request
+ * @type: delegation type
+ * @stateid: delegation stateid
+ * @pagemod_limit: write delegation "space_limit"
+ *
+ */
+void nfs_inode_reclaim_delegation(struct inode *inode, const struct cred *cred,
+				  fmode_t type, const nfs4_stateid *stateid,
+				  unsigned long pagemod_limit)
+{
+	struct nfs_delegation *delegation;
+	const struct cred *oldcred = NULL;
+
+	rcu_read_lock();
+	delegation = rcu_dereference(NFS_I(inode)->delegation);
+	if (delegation != NULL) {
+		spin_lock(&delegation->lock);
+		nfs4_stateid_copy(&delegation->stateid, stateid);
+		delegation->type = type;
+		delegation->pagemod_limit = pagemod_limit;
+		oldcred = delegation->cred;
+		delegation->cred = get_cred(cred);
+		clear_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags);
+		if (test_and_clear_bit(NFS_DELEGATION_REVOKED,
+				       &delegation->flags))
+			atomic_long_inc(&nfs_active_delegations);
+		spin_unlock(&delegation->lock);
+		rcu_read_unlock();
+		put_cred(oldcred);
+		trace_nfs4_reclaim_delegation(inode, type);
+	} else {
+		rcu_read_unlock();
+		nfs_inode_set_delegation(inode, cred, type, stateid,
+					 pagemod_limit);
+	}
+}
+
+static int nfs_do_return_delegation(struct inode *inode, struct nfs_delegation *delegation, int issync)
+{
+	const struct cred *cred;
+	int res = 0;
+
+	if (!test_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) {
+		spin_lock(&delegation->lock);
+		cred = get_cred(delegation->cred);
+		spin_unlock(&delegation->lock);
+		res = nfs4_proc_delegreturn(inode, cred,
+				&delegation->stateid,
+				issync);
+		put_cred(cred);
+	}
+	return res;
+}
+
+static struct inode *nfs_delegation_grab_inode(struct nfs_delegation *delegation)
+{
+	struct inode *inode = NULL;
+
+	spin_lock(&delegation->lock);
+	if (delegation->inode != NULL)
+		inode = igrab(delegation->inode);
+	if (!inode)
+		set_bit(NFS_DELEGATION_INODE_FREEING, &delegation->flags);
+	spin_unlock(&delegation->lock);
+	return inode;
+}
+
+static struct nfs_delegation *
+nfs_start_delegation_return_locked(struct nfs_inode *nfsi)
+{
+	struct nfs_delegation *ret = NULL;
+	struct nfs_delegation *delegation = rcu_dereference(nfsi->delegation);
+
+	if (delegation == NULL)
+		goto out;
+	spin_lock(&delegation->lock);
+	if (!test_and_set_bit(NFS_DELEGATION_RETURNING, &delegation->flags)) {
+		clear_bit(NFS_DELEGATION_RETURN_DELAYED, &delegation->flags);
+		/* Refcount matched in nfs_end_delegation_return() */
+		ret = nfs_get_delegation(delegation);
+	}
+	spin_unlock(&delegation->lock);
+	if (ret)
+		nfs_clear_verifier_delegated(&nfsi->vfs_inode);
+out:
+	return ret;
+}
+
+static struct nfs_delegation *
+nfs_start_delegation_return(struct nfs_inode *nfsi)
+{
+	struct nfs_delegation *delegation;
+
+	rcu_read_lock();
+	delegation = nfs_start_delegation_return_locked(nfsi);
+	rcu_read_unlock();
+	return delegation;
+}
+
+static void nfs_abort_delegation_return(struct nfs_delegation *delegation,
+					struct nfs_client *clp, int err)
+{
+
+	spin_lock(&delegation->lock);
+	clear_bit(NFS_DELEGATION_RETURNING, &delegation->flags);
+	if (err == -EAGAIN) {
+		set_bit(NFS_DELEGATION_RETURN_DELAYED, &delegation->flags);
+		set_bit(NFS4CLNT_DELEGRETURN_DELAYED, &clp->cl_state);
+	}
+	spin_unlock(&delegation->lock);
+}
+
+static struct nfs_delegation *
+nfs_detach_delegation_locked(struct nfs_inode *nfsi,
+		struct nfs_delegation *delegation,
+		struct nfs_client *clp)
+{
+	struct nfs_delegation *deleg_cur =
+		rcu_dereference_protected(nfsi->delegation,
+				lockdep_is_held(&clp->cl_lock));
+
+	if (deleg_cur == NULL || delegation != deleg_cur)
+		return NULL;
+
+	spin_lock(&delegation->lock);
+	if (!delegation->inode) {
+		spin_unlock(&delegation->lock);
+		return NULL;
+	}
+	list_del_rcu(&delegation->super_list);
+	delegation->inode = NULL;
+	rcu_assign_pointer(nfsi->delegation, NULL);
+	spin_unlock(&delegation->lock);
+	return delegation;
+}
+
+static struct nfs_delegation *nfs_detach_delegation(struct nfs_inode *nfsi,
+		struct nfs_delegation *delegation,
+		struct nfs_server *server)
+{
+	struct nfs_client *clp = server->nfs_client;
+
+	spin_lock(&clp->cl_lock);
+	delegation = nfs_detach_delegation_locked(nfsi, delegation, clp);
+	spin_unlock(&clp->cl_lock);
+	return delegation;
+}
+
+static struct nfs_delegation *
+nfs_inode_detach_delegation(struct inode *inode)
+{
+	struct nfs_inode *nfsi = NFS_I(inode);
+	struct nfs_server *server = NFS_SERVER(inode);
+	struct nfs_delegation *delegation;
+
+	rcu_read_lock();
+	delegation = rcu_dereference(nfsi->delegation);
+	if (delegation != NULL)
+		delegation = nfs_detach_delegation(nfsi, delegation, server);
+	rcu_read_unlock();
+	return delegation;
+}
+
+static void
+nfs_update_delegation_cred(struct nfs_delegation *delegation,
+		const struct cred *cred)
+{
+	const struct cred *old;
+
+	if (cred_fscmp(delegation->cred, cred) != 0) {
+		old = xchg(&delegation->cred, get_cred(cred));
+		put_cred(old);
+	}
+}
+
+static void
+nfs_update_inplace_delegation(struct nfs_delegation *delegation,
+		const struct nfs_delegation *update)
+{
+	if (nfs4_stateid_is_newer(&update->stateid, &delegation->stateid)) {
+		delegation->stateid.seqid = update->stateid.seqid;
+		smp_wmb();
+		delegation->type = update->type;
+		delegation->pagemod_limit = update->pagemod_limit;
+		if (test_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) {
+			delegation->change_attr = update->change_attr;
+			nfs_update_delegation_cred(delegation, update->cred);
+			/* smp_mb__before_atomic() is implicit due to xchg() */
+			clear_bit(NFS_DELEGATION_REVOKED, &delegation->flags);
+			atomic_long_inc(&nfs_active_delegations);
+		}
+	}
+}
+
+/**
+ * nfs_inode_set_delegation - set up a delegation on an inode
+ * @inode: inode to which delegation applies
+ * @cred: cred to use for subsequent delegation processing
+ * @type: delegation type
+ * @stateid: delegation stateid
+ * @pagemod_limit: write delegation "space_limit"
+ *
+ * Returns zero on success, or a negative errno value.
+ */
+int nfs_inode_set_delegation(struct inode *inode, const struct cred *cred,
+				  fmode_t type,
+				  const nfs4_stateid *stateid,
+				  unsigned long pagemod_limit)
+{
+	struct nfs_server *server = NFS_SERVER(inode);
+	struct nfs_client *clp = server->nfs_client;
+	struct nfs_inode *nfsi = NFS_I(inode);
+	struct nfs_delegation *delegation, *old_delegation;
+	struct nfs_delegation *freeme = NULL;
+	int status = 0;
+
+	delegation = kmalloc(sizeof(*delegation), GFP_NOFS);
+	if (delegation == NULL)
+		return -ENOMEM;
+	nfs4_stateid_copy(&delegation->stateid, stateid);
+	refcount_set(&delegation->refcount, 1);
+	delegation->type = type;
+	delegation->pagemod_limit = pagemod_limit;
+	delegation->change_attr = inode_peek_iversion_raw(inode);
+	delegation->cred = get_cred(cred);
+	delegation->inode = inode;
+	delegation->flags = 1<<NFS_DELEGATION_REFERENCED;
+	spin_lock_init(&delegation->lock);
+
+	spin_lock(&clp->cl_lock);
+	old_delegation = rcu_dereference_protected(nfsi->delegation,
+					lockdep_is_held(&clp->cl_lock));
+	if (old_delegation == NULL)
+		goto add_new;
+	/* Is this an update of the existing delegation? */
+	if (nfs4_stateid_match_other(&old_delegation->stateid,
+				&delegation->stateid)) {
+		spin_lock(&old_delegation->lock);
+		nfs_update_inplace_delegation(old_delegation,
+				delegation);
+		spin_unlock(&old_delegation->lock);
+		goto out;
+	}
+	if (!test_bit(NFS_DELEGATION_REVOKED, &old_delegation->flags)) {
+		/*
+		 * Deal with broken servers that hand out two
+		 * delegations for the same file.
+		 * Allow for upgrades to a WRITE delegation, but
+		 * nothing else.
+		 */
+		dfprintk(FILE, "%s: server %s handed out "
+				"a duplicate delegation!\n",
+				__func__, clp->cl_hostname);
+		if (delegation->type == old_delegation->type ||
+		    !(delegation->type & FMODE_WRITE)) {
+			freeme = delegation;
+			delegation = NULL;
+			goto out;
+		}
+		if (test_and_set_bit(NFS_DELEGATION_RETURNING,
+					&old_delegation->flags))
+			goto out;
+	}
+	freeme = nfs_detach_delegation_locked(nfsi, old_delegation, clp);
+	if (freeme == NULL)
+		goto out;
+add_new:
+	list_add_tail_rcu(&delegation->super_list, &server->delegations);
+	rcu_assign_pointer(nfsi->delegation, delegation);
+	delegation = NULL;
+
+	atomic_long_inc(&nfs_active_delegations);
+
+	trace_nfs4_set_delegation(inode, type);
+
+	spin_lock(&inode->i_lock);
+	if (NFS_I(inode)->cache_validity & (NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ATIME))
+		NFS_I(inode)->cache_validity |= NFS_INO_REVAL_FORCED;
+	spin_unlock(&inode->i_lock);
+out:
+	spin_unlock(&clp->cl_lock);
+	if (delegation != NULL)
+		__nfs_free_delegation(delegation);
+	if (freeme != NULL) {
+		nfs_do_return_delegation(inode, freeme, 0);
+		nfs_free_delegation(freeme);
+	}
+	return status;
+}
+
+/*
+ * Basic procedure for returning a delegation to the server
+ */
+static int nfs_end_delegation_return(struct inode *inode, struct nfs_delegation *delegation, int issync)
+{
+	struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
+	int err = 0;
+
+	if (delegation == NULL)
+		return 0;
+	do {
+		if (test_bit(NFS_DELEGATION_REVOKED, &delegation->flags))
+			break;
+		err = nfs_delegation_claim_opens(inode, &delegation->stateid,
+				delegation->type);
+		if (!issync || err != -EAGAIN)
+			break;
+		/*
+		 * Guard against state recovery
+		 */
+		err = nfs4_wait_clnt_recover(clp);
+	} while (err == 0);
+
+	if (err) {
+		nfs_abort_delegation_return(delegation, clp, err);
+		goto out;
+	}
+
+	err = nfs_do_return_delegation(inode, delegation, issync);
+out:
+	/* Refcount matched in nfs_start_delegation_return_locked() */
+	nfs_put_delegation(delegation);
+	return err;
+}
+
+static bool nfs_delegation_need_return(struct nfs_delegation *delegation)
+{
+	bool ret = false;
+
+	if (test_and_clear_bit(NFS_DELEGATION_RETURN, &delegation->flags))
+		ret = true;
+	else if (test_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags)) {
+		struct inode *inode;
+
+		spin_lock(&delegation->lock);
+		inode = delegation->inode;
+		if (inode && list_empty(&NFS_I(inode)->open_files))
+			ret = true;
+		spin_unlock(&delegation->lock);
+	}
+	if (ret)
+		clear_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags);
+	if (test_bit(NFS_DELEGATION_RETURNING, &delegation->flags) ||
+	    test_bit(NFS_DELEGATION_RETURN_DELAYED, &delegation->flags) ||
+	    test_bit(NFS_DELEGATION_REVOKED, &delegation->flags))
+		ret = false;
+
+	return ret;
+}
+
+static int nfs_server_return_marked_delegations(struct nfs_server *server,
+		void __always_unused *data)
+{
+	struct nfs_delegation *delegation;
+	struct nfs_delegation *prev;
+	struct inode *inode;
+	struct inode *place_holder = NULL;
+	struct nfs_delegation *place_holder_deleg = NULL;
+	int err = 0;
+
+restart:
+	/*
+	 * To avoid quadratic looping we hold a reference
+	 * to an inode place_holder.  Each time we restart, we
+	 * list delegation in the server from the delegations
+	 * of that inode.
+	 * prev is an RCU-protected pointer to a delegation which
+	 * wasn't marked for return and might be a good choice for
+	 * the next place_holder.
+	 */
+	prev = NULL;
+	delegation = NULL;
+	rcu_read_lock();
+	if (place_holder)
+		delegation = rcu_dereference(NFS_I(place_holder)->delegation);
+	if (!delegation || delegation != place_holder_deleg)
+		delegation = list_entry_rcu(server->delegations.next,
+					    struct nfs_delegation, super_list);
+	list_for_each_entry_from_rcu(delegation, &server->delegations, super_list) {
+		struct inode *to_put = NULL;
+
+		if (test_bit(NFS_DELEGATION_INODE_FREEING, &delegation->flags))
+			continue;
+		if (!nfs_delegation_need_return(delegation)) {
+			if (nfs4_is_valid_delegation(delegation, 0))
+				prev = delegation;
+			continue;
+		}
+
+		if (prev) {
+			struct inode *tmp = nfs_delegation_grab_inode(prev);
+			if (tmp) {
+				to_put = place_holder;
+				place_holder = tmp;
+				place_holder_deleg = prev;
+			}
+		}
+
+		inode = nfs_delegation_grab_inode(delegation);
+		if (inode == NULL) {
+			rcu_read_unlock();
+			iput(to_put);
+			goto restart;
+		}
+		delegation = nfs_start_delegation_return_locked(NFS_I(inode));
+		rcu_read_unlock();
+
+		iput(to_put);
+
+		err = nfs_end_delegation_return(inode, delegation, 0);
+		iput(inode);
+		cond_resched();
+		if (!err)
+			goto restart;
+		set_bit(NFS4CLNT_DELEGRETURN, &server->nfs_client->cl_state);
+		goto out;
+	}
+	rcu_read_unlock();
+out:
+	iput(place_holder);
+	return err;
+}
+
+static bool nfs_server_clear_delayed_delegations(struct nfs_server *server)
+{
+	struct nfs_delegation *d;
+	bool ret = false;
+
+	list_for_each_entry_rcu (d, &server->delegations, super_list) {
+		if (!test_bit(NFS_DELEGATION_RETURN_DELAYED, &d->flags))
+			continue;
+		nfs_mark_return_delegation(server, d);
+		clear_bit(NFS_DELEGATION_RETURN_DELAYED, &d->flags);
+		ret = true;
+	}
+	return ret;
+}
+
+static bool nfs_client_clear_delayed_delegations(struct nfs_client *clp)
+{
+	struct nfs_server *server;
+	bool ret = false;
+
+	if (!test_and_clear_bit(NFS4CLNT_DELEGRETURN_DELAYED, &clp->cl_state))
+		goto out;
+	rcu_read_lock();
+	list_for_each_entry_rcu (server, &clp->cl_superblocks, client_link) {
+		if (nfs_server_clear_delayed_delegations(server))
+			ret = true;
+	}
+	rcu_read_unlock();
+out:
+	return ret;
+}
+
+/**
+ * nfs_client_return_marked_delegations - return previously marked delegations
+ * @clp: nfs_client to process
+ *
+ * Note that this function is designed to be called by the state
+ * manager thread. For this reason, it cannot flush the dirty data,
+ * since that could deadlock in case of a state recovery error.
+ *
+ * Returns zero on success, or a negative errno value.
+ */
+int nfs_client_return_marked_delegations(struct nfs_client *clp)
+{
+	int err = nfs_client_for_each_server(
+		clp, nfs_server_return_marked_delegations, NULL);
+	if (err)
+		return err;
+	/* If a return was delayed, sleep to prevent hard looping */
+	if (nfs_client_clear_delayed_delegations(clp))
+		ssleep(1);
+	return 0;
+}
+
+/**
+ * nfs_inode_evict_delegation - return delegation, don't reclaim opens
+ * @inode: inode to process
+ *
+ * Does not protect against delegation reclaims, therefore really only safe
+ * to be called from nfs4_clear_inode(). Guaranteed to always free
+ * the delegation structure.
+ */
+void nfs_inode_evict_delegation(struct inode *inode)
+{
+	struct nfs_delegation *delegation;
+
+	delegation = nfs_inode_detach_delegation(inode);
+	if (delegation != NULL) {
+		set_bit(NFS_DELEGATION_RETURNING, &delegation->flags);
+		set_bit(NFS_DELEGATION_INODE_FREEING, &delegation->flags);
+		nfs_do_return_delegation(inode, delegation, 1);
+		nfs_free_delegation(delegation);
+	}
+}
+
+/**
+ * nfs_inode_return_delegation - synchronously return a delegation
+ * @inode: inode to process
+ *
+ * This routine will always flush any dirty data to disk on the
+ * assumption that if we need to return the delegation, then
+ * we should stop caching.
+ *
+ * Returns zero on success, or a negative errno value.
+ */
+int nfs4_inode_return_delegation(struct inode *inode)
+{
+	struct nfs_inode *nfsi = NFS_I(inode);
+	struct nfs_delegation *delegation;
+	int err = 0;
+
+	nfs_wb_all(inode);
+	delegation = nfs_start_delegation_return(nfsi);
+	if (delegation != NULL)
+		err = nfs_end_delegation_return(inode, delegation, 1);
+	return err;
+}
+
+/**
+ * nfs_inode_return_delegation_on_close - asynchronously return a delegation
+ * @inode: inode to process
+ *
+ * This routine is called on file close in order to determine if the
+ * inode delegation needs to be returned immediately.
+ */
+void nfs4_inode_return_delegation_on_close(struct inode *inode)
+{
+	struct nfs_delegation *delegation;
+	struct nfs_delegation *ret = NULL;
+
+	if (!inode)
+		return;
+	rcu_read_lock();
+	delegation = nfs4_get_valid_delegation(inode);
+	if (!delegation)
+		goto out;
+	if (test_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags) ||
+	    atomic_long_read(&nfs_active_delegations) >= nfs_delegation_watermark) {
+		spin_lock(&delegation->lock);
+		if (delegation->inode &&
+		    list_empty(&NFS_I(inode)->open_files) &&
+		    !test_and_set_bit(NFS_DELEGATION_RETURNING, &delegation->flags)) {
+			clear_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags);
+			/* Refcount matched in nfs_end_delegation_return() */
+			ret = nfs_get_delegation(delegation);
+		}
+		spin_unlock(&delegation->lock);
+		if (ret)
+			nfs_clear_verifier_delegated(inode);
+	}
+out:
+	rcu_read_unlock();
+	nfs_end_delegation_return(inode, ret, 0);
+}
+
+/**
+ * nfs4_inode_make_writeable
+ * @inode: pointer to inode
+ *
+ * Make the inode writeable by returning the delegation if necessary
+ *
+ * Returns zero on success, or a negative errno value.
+ */
+int nfs4_inode_make_writeable(struct inode *inode)
+{
+	struct nfs_delegation *delegation;
+
+	rcu_read_lock();
+	delegation = nfs4_get_valid_delegation(inode);
+	if (delegation == NULL ||
+	    (nfs4_has_session(NFS_SERVER(inode)->nfs_client) &&
+	     (delegation->type & FMODE_WRITE))) {
+		rcu_read_unlock();
+		return 0;
+	}
+	rcu_read_unlock();
+	return nfs4_inode_return_delegation(inode);
+}
+
+static void nfs_mark_return_if_closed_delegation(struct nfs_server *server,
+		struct nfs_delegation *delegation)
+{
+	set_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags);
+	set_bit(NFS4CLNT_DELEGRETURN, &server->nfs_client->cl_state);
+}
+
+static bool nfs_server_mark_return_all_delegations(struct nfs_server *server)
+{
+	struct nfs_delegation *delegation;
+	bool ret = false;
+
+	list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
+		nfs_mark_return_delegation(server, delegation);
+		ret = true;
+	}
+	return ret;
+}
+
+static void nfs_client_mark_return_all_delegations(struct nfs_client *clp)
+{
+	struct nfs_server *server;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
+		nfs_server_mark_return_all_delegations(server);
+	rcu_read_unlock();
+}
+
+static void nfs_delegation_run_state_manager(struct nfs_client *clp)
+{
+	if (test_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state))
+		nfs4_schedule_state_manager(clp);
+}
+
+/**
+ * nfs_expire_all_delegations
+ * @clp: client to process
+ *
+ */
+void nfs_expire_all_delegations(struct nfs_client *clp)
+{
+	nfs_client_mark_return_all_delegations(clp);
+	nfs_delegation_run_state_manager(clp);
+}
+
+/**
+ * nfs_super_return_all_delegations - return delegations for one superblock
+ * @server: pointer to nfs_server to process
+ *
+ */
+void nfs_server_return_all_delegations(struct nfs_server *server)
+{
+	struct nfs_client *clp = server->nfs_client;
+	bool need_wait;
+
+	if (clp == NULL)
+		return;
+
+	rcu_read_lock();
+	need_wait = nfs_server_mark_return_all_delegations(server);
+	rcu_read_unlock();
+
+	if (need_wait) {
+		nfs4_schedule_state_manager(clp);
+		nfs4_wait_clnt_recover(clp);
+	}
+}
+
+static void nfs_mark_return_unused_delegation_types(struct nfs_server *server,
+						 fmode_t flags)
+{
+	struct nfs_delegation *delegation;
+
+	list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
+		if ((delegation->type == (FMODE_READ|FMODE_WRITE)) && !(flags & FMODE_WRITE))
+			continue;
+		if (delegation->type & flags)
+			nfs_mark_return_if_closed_delegation(server, delegation);
+	}
+}
+
+static void nfs_client_mark_return_unused_delegation_types(struct nfs_client *clp,
+							fmode_t flags)
+{
+	struct nfs_server *server;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
+		nfs_mark_return_unused_delegation_types(server, flags);
+	rcu_read_unlock();
+}
+
+static void nfs_revoke_delegation(struct inode *inode,
+		const nfs4_stateid *stateid)
+{
+	struct nfs_delegation *delegation;
+	nfs4_stateid tmp;
+	bool ret = false;
+
+	rcu_read_lock();
+	delegation = rcu_dereference(NFS_I(inode)->delegation);
+	if (delegation == NULL)
+		goto out;
+	if (stateid == NULL) {
+		nfs4_stateid_copy(&tmp, &delegation->stateid);
+		stateid = &tmp;
+	} else {
+		if (!nfs4_stateid_match_other(stateid, &delegation->stateid))
+			goto out;
+		spin_lock(&delegation->lock);
+		if (stateid->seqid) {
+			if (nfs4_stateid_is_newer(&delegation->stateid, stateid)) {
+				spin_unlock(&delegation->lock);
+				goto out;
+			}
+			delegation->stateid.seqid = stateid->seqid;
+		}
+		spin_unlock(&delegation->lock);
+	}
+	nfs_mark_delegation_revoked(delegation);
+	ret = true;
+out:
+	rcu_read_unlock();
+	if (ret)
+		nfs_inode_find_state_and_recover(inode, stateid);
+}
+
+void nfs_remove_bad_delegation(struct inode *inode,
+		const nfs4_stateid *stateid)
+{
+	nfs_revoke_delegation(inode, stateid);
+}
+EXPORT_SYMBOL_GPL(nfs_remove_bad_delegation);
+
+void nfs_delegation_mark_returned(struct inode *inode,
+		const nfs4_stateid *stateid)
+{
+	struct nfs_delegation *delegation;
+
+	if (!inode)
+		return;
+
+	rcu_read_lock();
+	delegation = rcu_dereference(NFS_I(inode)->delegation);
+	if (!delegation)
+		goto out_rcu_unlock;
+
+	spin_lock(&delegation->lock);
+	if (!nfs4_stateid_match_other(stateid, &delegation->stateid))
+		goto out_spin_unlock;
+	if (stateid->seqid) {
+		/* If delegation->stateid is newer, dont mark as returned */
+		if (nfs4_stateid_is_newer(&delegation->stateid, stateid))
+			goto out_clear_returning;
+		if (delegation->stateid.seqid != stateid->seqid)
+			delegation->stateid.seqid = stateid->seqid;
+	}
+
+	nfs_mark_delegation_revoked(delegation);
+
+out_clear_returning:
+	clear_bit(NFS_DELEGATION_RETURNING, &delegation->flags);
+out_spin_unlock:
+	spin_unlock(&delegation->lock);
+out_rcu_unlock:
+	rcu_read_unlock();
+
+	nfs_inode_find_state_and_recover(inode, stateid);
+}
+
+/**
+ * nfs_expire_unused_delegation_types
+ * @clp: client to process
+ * @flags: delegation types to expire
+ *
+ */
+void nfs_expire_unused_delegation_types(struct nfs_client *clp, fmode_t flags)
+{
+	nfs_client_mark_return_unused_delegation_types(clp, flags);
+	nfs_delegation_run_state_manager(clp);
+}
+
+static void nfs_mark_return_unreferenced_delegations(struct nfs_server *server)
+{
+	struct nfs_delegation *delegation;
+
+	list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
+		if (test_and_clear_bit(NFS_DELEGATION_REFERENCED, &delegation->flags))
+			continue;
+		nfs_mark_return_if_closed_delegation(server, delegation);
+	}
+}
+
+/**
+ * nfs_expire_unreferenced_delegations - Eliminate unused delegations
+ * @clp: nfs_client to process
+ *
+ */
+void nfs_expire_unreferenced_delegations(struct nfs_client *clp)
+{
+	struct nfs_server *server;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
+		nfs_mark_return_unreferenced_delegations(server);
+	rcu_read_unlock();
+
+	nfs_delegation_run_state_manager(clp);
+}
+
+/**
+ * nfs_async_inode_return_delegation - asynchronously return a delegation
+ * @inode: inode to process
+ * @stateid: state ID information
+ *
+ * Returns zero on success, or a negative errno value.
+ */
+int nfs_async_inode_return_delegation(struct inode *inode,
+				      const nfs4_stateid *stateid)
+{
+	struct nfs_server *server = NFS_SERVER(inode);
+	struct nfs_client *clp = server->nfs_client;
+	struct nfs_delegation *delegation;
+
+	rcu_read_lock();
+	delegation = nfs4_get_valid_delegation(inode);
+	if (delegation == NULL)
+		goto out_enoent;
+	if (stateid != NULL &&
+	    !clp->cl_mvops->match_stateid(&delegation->stateid, stateid))
+		goto out_enoent;
+	nfs_mark_return_delegation(server, delegation);
+	rcu_read_unlock();
+
+	nfs_delegation_run_state_manager(clp);
+	return 0;
+out_enoent:
+	rcu_read_unlock();
+	return -ENOENT;
+}
+
+static struct inode *
+nfs_delegation_find_inode_server(struct nfs_server *server,
+				 const struct nfs_fh *fhandle)
+{
+	struct nfs_delegation *delegation;
+	struct super_block *freeme = NULL;
+	struct inode *res = NULL;
+
+	list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
+		spin_lock(&delegation->lock);
+		if (delegation->inode != NULL &&
+		    !test_bit(NFS_DELEGATION_REVOKED, &delegation->flags) &&
+		    nfs_compare_fh(fhandle, &NFS_I(delegation->inode)->fh) == 0) {
+			if (nfs_sb_active(server->super)) {
+				freeme = server->super;
+				res = igrab(delegation->inode);
+			}
+			spin_unlock(&delegation->lock);
+			if (res != NULL)
+				return res;
+			if (freeme) {
+				rcu_read_unlock();
+				nfs_sb_deactive(freeme);
+				rcu_read_lock();
+			}
+			return ERR_PTR(-EAGAIN);
+		}
+		spin_unlock(&delegation->lock);
+	}
+	return ERR_PTR(-ENOENT);
+}
+
+/**
+ * nfs_delegation_find_inode - retrieve the inode associated with a delegation
+ * @clp: client state handle
+ * @fhandle: filehandle from a delegation recall
+ *
+ * Returns pointer to inode matching "fhandle," or NULL if a matching inode
+ * cannot be found.
+ */
+struct inode *nfs_delegation_find_inode(struct nfs_client *clp,
+					const struct nfs_fh *fhandle)
+{
+	struct nfs_server *server;
+	struct inode *res;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
+		res = nfs_delegation_find_inode_server(server, fhandle);
+		if (res != ERR_PTR(-ENOENT)) {
+			rcu_read_unlock();
+			return res;
+		}
+	}
+	rcu_read_unlock();
+	return ERR_PTR(-ENOENT);
+}
+
+static void nfs_delegation_mark_reclaim_server(struct nfs_server *server)
+{
+	struct nfs_delegation *delegation;
+
+	list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
+		/*
+		 * If the delegation may have been admin revoked, then we
+		 * cannot reclaim it.
+		 */
+		if (test_bit(NFS_DELEGATION_TEST_EXPIRED, &delegation->flags))
+			continue;
+		set_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags);
+	}
+}
+
+/**
+ * nfs_delegation_mark_reclaim - mark all delegations as needing to be reclaimed
+ * @clp: nfs_client to process
+ *
+ */
+void nfs_delegation_mark_reclaim(struct nfs_client *clp)
+{
+	struct nfs_server *server;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
+		nfs_delegation_mark_reclaim_server(server);
+	rcu_read_unlock();
+}
+
+static int nfs_server_reap_unclaimed_delegations(struct nfs_server *server,
+		void __always_unused *data)
+{
+	struct nfs_delegation *delegation;
+	struct inode *inode;
+restart:
+	rcu_read_lock();
+restart_locked:
+	list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
+		if (test_bit(NFS_DELEGATION_INODE_FREEING,
+					&delegation->flags) ||
+		    test_bit(NFS_DELEGATION_RETURNING,
+					&delegation->flags) ||
+		    test_bit(NFS_DELEGATION_NEED_RECLAIM,
+					&delegation->flags) == 0)
+			continue;
+		inode = nfs_delegation_grab_inode(delegation);
+		if (inode == NULL)
+			goto restart_locked;
+		delegation = nfs_start_delegation_return_locked(NFS_I(inode));
+		rcu_read_unlock();
+		if (delegation != NULL) {
+			if (nfs_detach_delegation(NFS_I(inode), delegation,
+						server) != NULL)
+				nfs_free_delegation(delegation);
+			/* Match nfs_start_delegation_return_locked */
+			nfs_put_delegation(delegation);
+		}
+		iput(inode);
+		cond_resched();
+		goto restart;
+	}
+	rcu_read_unlock();
+	return 0;
+}
+
+/**
+ * nfs_delegation_reap_unclaimed - reap unclaimed delegations after reboot recovery is done
+ * @clp: nfs_client to process
+ *
+ */
+void nfs_delegation_reap_unclaimed(struct nfs_client *clp)
+{
+	nfs_client_for_each_server(clp, nfs_server_reap_unclaimed_delegations,
+			NULL);
+}
+
+static inline bool nfs4_server_rebooted(const struct nfs_client *clp)
+{
+	return (clp->cl_state & (BIT(NFS4CLNT_CHECK_LEASE) |
+				BIT(NFS4CLNT_LEASE_EXPIRED) |
+				BIT(NFS4CLNT_SESSION_RESET))) != 0;
+}
+
+static void nfs_mark_test_expired_delegation(struct nfs_server *server,
+	    struct nfs_delegation *delegation)
+{
+	if (delegation->stateid.type == NFS4_INVALID_STATEID_TYPE)
+		return;
+	clear_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags);
+	set_bit(NFS_DELEGATION_TEST_EXPIRED, &delegation->flags);
+	set_bit(NFS4CLNT_DELEGATION_EXPIRED, &server->nfs_client->cl_state);
+}
+
+static void nfs_inode_mark_test_expired_delegation(struct nfs_server *server,
+		struct inode *inode)
+{
+	struct nfs_delegation *delegation;
+
+	rcu_read_lock();
+	delegation = rcu_dereference(NFS_I(inode)->delegation);
+	if (delegation)
+		nfs_mark_test_expired_delegation(server, delegation);
+	rcu_read_unlock();
+
+}
+
+static void nfs_delegation_mark_test_expired_server(struct nfs_server *server)
+{
+	struct nfs_delegation *delegation;
+
+	list_for_each_entry_rcu(delegation, &server->delegations, super_list)
+		nfs_mark_test_expired_delegation(server, delegation);
+}
+
+/**
+ * nfs_mark_test_expired_all_delegations - mark all delegations for testing
+ * @clp: nfs_client to process
+ *
+ * Iterates through all the delegations associated with this server and
+ * marks them as needing to be checked for validity.
+ */
+void nfs_mark_test_expired_all_delegations(struct nfs_client *clp)
+{
+	struct nfs_server *server;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
+		nfs_delegation_mark_test_expired_server(server);
+	rcu_read_unlock();
+}
+
+/**
+ * nfs_test_expired_all_delegations - test all delegations for a client
+ * @clp: nfs_client to process
+ *
+ * Helper for handling "recallable state revoked" status from server.
+ */
+void nfs_test_expired_all_delegations(struct nfs_client *clp)
+{
+	nfs_mark_test_expired_all_delegations(clp);
+	nfs4_schedule_state_manager(clp);
+}
+
+static void
+nfs_delegation_test_free_expired(struct inode *inode,
+		nfs4_stateid *stateid,
+		const struct cred *cred)
+{
+	struct nfs_server *server = NFS_SERVER(inode);
+	const struct nfs4_minor_version_ops *ops = server->nfs_client->cl_mvops;
+	int status;
+
+	if (!cred)
+		return;
+	status = ops->test_and_free_expired(server, stateid, cred);
+	if (status == -NFS4ERR_EXPIRED || status == -NFS4ERR_BAD_STATEID)
+		nfs_remove_bad_delegation(inode, stateid);
+}
+
+static int nfs_server_reap_expired_delegations(struct nfs_server *server,
+		void __always_unused *data)
+{
+	struct nfs_delegation *delegation;
+	struct inode *inode;
+	const struct cred *cred;
+	nfs4_stateid stateid;
+restart:
+	rcu_read_lock();
+restart_locked:
+	list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
+		if (test_bit(NFS_DELEGATION_INODE_FREEING,
+					&delegation->flags) ||
+		    test_bit(NFS_DELEGATION_RETURNING,
+					&delegation->flags) ||
+		    test_bit(NFS_DELEGATION_TEST_EXPIRED,
+					&delegation->flags) == 0)
+			continue;
+		inode = nfs_delegation_grab_inode(delegation);
+		if (inode == NULL)
+			goto restart_locked;
+		spin_lock(&delegation->lock);
+		cred = get_cred_rcu(delegation->cred);
+		nfs4_stateid_copy(&stateid, &delegation->stateid);
+		spin_unlock(&delegation->lock);
+		clear_bit(NFS_DELEGATION_TEST_EXPIRED, &delegation->flags);
+		rcu_read_unlock();
+		nfs_delegation_test_free_expired(inode, &stateid, cred);
+		put_cred(cred);
+		if (!nfs4_server_rebooted(server->nfs_client)) {
+			iput(inode);
+			cond_resched();
+			goto restart;
+		}
+		nfs_inode_mark_test_expired_delegation(server,inode);
+		iput(inode);
+		return -EAGAIN;
+	}
+	rcu_read_unlock();
+	return 0;
+}
+
+/**
+ * nfs_reap_expired_delegations - reap expired delegations
+ * @clp: nfs_client to process
+ *
+ * Iterates through all the delegations associated with this server and
+ * checks if they have may have been revoked. This function is usually
+ * expected to be called in cases where the server may have lost its
+ * lease.
+ */
+void nfs_reap_expired_delegations(struct nfs_client *clp)
+{
+	nfs_client_for_each_server(clp, nfs_server_reap_expired_delegations,
+			NULL);
+}
+
+void nfs_inode_find_delegation_state_and_recover(struct inode *inode,
+		const nfs4_stateid *stateid)
+{
+	struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
+	struct nfs_delegation *delegation;
+	bool found = false;
+
+	rcu_read_lock();
+	delegation = rcu_dereference(NFS_I(inode)->delegation);
+	if (delegation &&
+	    nfs4_stateid_match_or_older(&delegation->stateid, stateid) &&
+	    !test_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) {
+		nfs_mark_test_expired_delegation(NFS_SERVER(inode), delegation);
+		found = true;
+	}
+	rcu_read_unlock();
+	if (found)
+		nfs4_schedule_state_manager(clp);
+}
+
+/**
+ * nfs_delegations_present - check for existence of delegations
+ * @clp: client state handle
+ *
+ * Returns one if there are any nfs_delegation structures attached
+ * to this nfs_client.
+ */
+int nfs_delegations_present(struct nfs_client *clp)
+{
+	struct nfs_server *server;
+	int ret = 0;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
+		if (!list_empty(&server->delegations)) {
+			ret = 1;
+			break;
+		}
+	rcu_read_unlock();
+	return ret;
+}
+
+/**
+ * nfs4_refresh_delegation_stateid - Update delegation stateid seqid
+ * @dst: stateid to refresh
+ * @inode: inode to check
+ *
+ * Returns "true" and updates "dst->seqid" * if inode had a delegation
+ * that matches our delegation stateid. Otherwise "false" is returned.
+ */
+bool nfs4_refresh_delegation_stateid(nfs4_stateid *dst, struct inode *inode)
+{
+	struct nfs_delegation *delegation;
+	bool ret = false;
+	if (!inode)
+		goto out;
+
+	rcu_read_lock();
+	delegation = rcu_dereference(NFS_I(inode)->delegation);
+	if (delegation != NULL &&
+	    nfs4_stateid_match_other(dst, &delegation->stateid) &&
+	    nfs4_stateid_is_newer(&delegation->stateid, dst) &&
+	    !test_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) {
+		dst->seqid = delegation->stateid.seqid;
+		ret = true;
+	}
+	rcu_read_unlock();
+out:
+	return ret;
+}
+
+/**
+ * nfs4_copy_delegation_stateid - Copy inode's state ID information
+ * @inode: inode to check
+ * @flags: delegation type requirement
+ * @dst: stateid data structure to fill in
+ * @cred: optional argument to retrieve credential
+ *
+ * Returns "true" and fills in "dst->data" * if inode had a delegation,
+ * otherwise "false" is returned.
+ */
+bool nfs4_copy_delegation_stateid(struct inode *inode, fmode_t flags,
+		nfs4_stateid *dst, const struct cred **cred)
+{
+	struct nfs_inode *nfsi = NFS_I(inode);
+	struct nfs_delegation *delegation;
+	bool ret = false;
+
+	flags &= FMODE_READ|FMODE_WRITE;
+	rcu_read_lock();
+	delegation = rcu_dereference(nfsi->delegation);
+	if (!delegation)
+		goto out;
+	spin_lock(&delegation->lock);
+	ret = nfs4_is_valid_delegation(delegation, flags);
+	if (ret) {
+		nfs4_stateid_copy(dst, &delegation->stateid);
+		nfs_mark_delegation_referenced(delegation);
+		if (cred)
+			*cred = get_cred(delegation->cred);
+	}
+	spin_unlock(&delegation->lock);
+out:
+	rcu_read_unlock();
+	return ret;
+}
+
+/**
+ * nfs4_delegation_flush_on_close - Check if we must flush file on close
+ * @inode: inode to check
+ *
+ * This function checks the number of outstanding writes to the file
+ * against the delegation 'space_limit' field to see if
+ * the spec requires us to flush the file on close.
+ */
+bool nfs4_delegation_flush_on_close(const struct inode *inode)
+{
+	struct nfs_inode *nfsi = NFS_I(inode);
+	struct nfs_delegation *delegation;
+	bool ret = true;
+
+	rcu_read_lock();
+	delegation = rcu_dereference(nfsi->delegation);
+	if (delegation == NULL || !(delegation->type & FMODE_WRITE))
+		goto out;
+	if (atomic_long_read(&nfsi->nrequests) < delegation->pagemod_limit)
+		ret = false;
+out:
+	rcu_read_unlock();
+	return ret;
+}
+
+module_param_named(delegation_watermark, nfs_delegation_watermark, uint, 0644);
diff --git a/fs/nfs/delegation.h b/fs/nfs/delegation.h
new file mode 100644
index 000000000..26f57a99d
--- /dev/null
+++ b/fs/nfs/delegation.h
@@ -0,0 +1,92 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * linux/fs/nfs/delegation.h
+ *
+ * Copyright (c) Trond Myklebust
+ *
+ * Definitions pertaining to NFS delegated files
+ */
+#ifndef FS_NFS_DELEGATION_H
+#define FS_NFS_DELEGATION_H
+
+#if IS_ENABLED(CONFIG_NFS_V4)
+/*
+ * NFSv4 delegation
+ */
+struct nfs_delegation {
+	struct list_head super_list;
+	const struct cred *cred;
+	struct inode *inode;
+	nfs4_stateid stateid;
+	fmode_t type;
+	unsigned long pagemod_limit;
+	__u64 change_attr;
+	unsigned long flags;
+	refcount_t refcount;
+	spinlock_t lock;
+	struct rcu_head rcu;
+};
+
+enum {
+	NFS_DELEGATION_NEED_RECLAIM = 0,
+	NFS_DELEGATION_RETURN,
+	NFS_DELEGATION_RETURN_IF_CLOSED,
+	NFS_DELEGATION_REFERENCED,
+	NFS_DELEGATION_RETURNING,
+	NFS_DELEGATION_REVOKED,
+	NFS_DELEGATION_TEST_EXPIRED,
+	NFS_DELEGATION_INODE_FREEING,
+	NFS_DELEGATION_RETURN_DELAYED,
+};
+
+int nfs_inode_set_delegation(struct inode *inode, const struct cred *cred,
+		fmode_t type, const nfs4_stateid *stateid, unsigned long pagemod_limit);
+void nfs_inode_reclaim_delegation(struct inode *inode, const struct cred *cred,
+		fmode_t type, const nfs4_stateid *stateid, unsigned long pagemod_limit);
+int nfs4_inode_return_delegation(struct inode *inode);
+void nfs4_inode_return_delegation_on_close(struct inode *inode);
+int nfs_async_inode_return_delegation(struct inode *inode, const nfs4_stateid *stateid);
+void nfs_inode_evict_delegation(struct inode *inode);
+
+struct inode *nfs_delegation_find_inode(struct nfs_client *clp, const struct nfs_fh *fhandle);
+void nfs_server_return_all_delegations(struct nfs_server *);
+void nfs_expire_all_delegations(struct nfs_client *clp);
+void nfs_expire_unused_delegation_types(struct nfs_client *clp, fmode_t flags);
+void nfs_expire_unreferenced_delegations(struct nfs_client *clp);
+int nfs_client_return_marked_delegations(struct nfs_client *clp);
+int nfs_delegations_present(struct nfs_client *clp);
+void nfs_remove_bad_delegation(struct inode *inode, const nfs4_stateid *stateid);
+void nfs_delegation_mark_returned(struct inode *inode, const nfs4_stateid *stateid);
+
+void nfs_delegation_mark_reclaim(struct nfs_client *clp);
+void nfs_delegation_reap_unclaimed(struct nfs_client *clp);
+
+void nfs_mark_test_expired_all_delegations(struct nfs_client *clp);
+void nfs_test_expired_all_delegations(struct nfs_client *clp);
+void nfs_reap_expired_delegations(struct nfs_client *clp);
+
+/* NFSv4 delegation-related procedures */
+int nfs4_proc_delegreturn(struct inode *inode, const struct cred *cred, const nfs4_stateid *stateid, int issync);
+int nfs4_open_delegation_recall(struct nfs_open_context *ctx, struct nfs4_state *state, const nfs4_stateid *stateid);
+int nfs4_lock_delegation_recall(struct file_lock *fl, struct nfs4_state *state, const nfs4_stateid *stateid);
+bool nfs4_copy_delegation_stateid(struct inode *inode, fmode_t flags, nfs4_stateid *dst, const struct cred **cred);
+bool nfs4_refresh_delegation_stateid(nfs4_stateid *dst, struct inode *inode);
+
+struct nfs_delegation *nfs4_get_valid_delegation(const struct inode *inode);
+void nfs_mark_delegation_referenced(struct nfs_delegation *delegation);
+int nfs4_have_delegation(struct inode *inode, fmode_t flags);
+int nfs4_check_delegation(struct inode *inode, fmode_t flags);
+bool nfs4_delegation_flush_on_close(const struct inode *inode);
+void nfs_inode_find_delegation_state_and_recover(struct inode *inode,
+		const nfs4_stateid *stateid);
+int nfs4_inode_make_writeable(struct inode *inode);
+
+#endif
+
+static inline int nfs_have_delegated_attributes(struct inode *inode)
+{
+	return NFS_PROTO(inode)->have_delegation(inode, FMODE_READ) &&
+		!(NFS_I(inode)->cache_validity & NFS_INO_REVAL_FORCED);
+}
+
+#endif
diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
new file mode 100644
index 000000000..9f88ca7b2
--- /dev/null
+++ b/fs/nfs/dir.c
@@ -0,0 +1,2820 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  linux/fs/nfs/dir.c
+ *
+ *  Copyright (C) 1992  Rick Sladkey
+ *
+ *  nfs directory handling functions
+ *
+ * 10 Apr 1996	Added silly rename for unlink	--okir
+ * 28 Sep 1996	Improved directory cache --okir
+ * 23 Aug 1997  Claus Heine claus@momo.math.rwth-aachen.de 
+ *              Re-implemented silly rename for unlink, newly implemented
+ *              silly rename for nfs_rename() following the suggestions
+ *              of Olaf Kirch (okir) found in this file.
+ *              Following Linus comments on my original hack, this version
+ *              depends only on the dcache stuff and doesn't touch the inode
+ *              layer (iput() and friends).
+ *  6 Jun 1999	Cache readdir lookups in the page cache. -DaveM
+ */
+
+#include <linux/module.h>
+#include <linux/time.h>
+#include <linux/errno.h>
+#include <linux/stat.h>
+#include <linux/fcntl.h>
+#include <linux/string.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/mm.h>
+#include <linux/sunrpc/clnt.h>
+#include <linux/nfs_fs.h>
+#include <linux/nfs_mount.h>
+#include <linux/pagemap.h>
+#include <linux/pagevec.h>
+#include <linux/namei.h>
+#include <linux/mount.h>
+#include <linux/swap.h>
+#include <linux/sched.h>
+#include <linux/kmemleak.h>
+#include <linux/xattr.h>
+
+#include "delegation.h"
+#include "iostat.h"
+#include "internal.h"
+#include "fscache.h"
+
+#include "nfstrace.h"
+
+/* #define NFS_DEBUG_VERBOSE 1 */
+
+static int nfs_opendir(struct inode *, struct file *);
+static int nfs_closedir(struct inode *, struct file *);
+static int nfs_readdir(struct file *, struct dir_context *);
+static int nfs_fsync_dir(struct file *, loff_t, loff_t, int);
+static loff_t nfs_llseek_dir(struct file *, loff_t, int);
+static void nfs_readdir_clear_array(struct page*);
+
+const struct file_operations nfs_dir_operations = {
+	.llseek		= nfs_llseek_dir,
+	.read		= generic_read_dir,
+	.iterate_shared	= nfs_readdir,
+	.open		= nfs_opendir,
+	.release	= nfs_closedir,
+	.fsync		= nfs_fsync_dir,
+};
+
+const struct address_space_operations nfs_dir_aops = {
+	.freepage = nfs_readdir_clear_array,
+};
+
+static struct nfs_open_dir_context *alloc_nfs_open_dir_context(struct inode *dir, const struct cred *cred)
+{
+	struct nfs_inode *nfsi = NFS_I(dir);
+	struct nfs_open_dir_context *ctx;
+	ctx = kmalloc(sizeof(*ctx), GFP_KERNEL);
+	if (ctx != NULL) {
+		ctx->duped = 0;
+		ctx->attr_gencount = nfsi->attr_gencount;
+		ctx->dir_cookie = 0;
+		ctx->dup_cookie = 0;
+		ctx->cred = get_cred(cred);
+		spin_lock(&dir->i_lock);
+		if (list_empty(&nfsi->open_files) &&
+		    (nfsi->cache_validity & NFS_INO_DATA_INVAL_DEFER))
+			nfsi->cache_validity |= NFS_INO_INVALID_DATA |
+				NFS_INO_REVAL_FORCED;
+		list_add(&ctx->list, &nfsi->open_files);
+		spin_unlock(&dir->i_lock);
+		return ctx;
+	}
+	return  ERR_PTR(-ENOMEM);
+}
+
+static void put_nfs_open_dir_context(struct inode *dir, struct nfs_open_dir_context *ctx)
+{
+	spin_lock(&dir->i_lock);
+	list_del(&ctx->list);
+	spin_unlock(&dir->i_lock);
+	put_cred(ctx->cred);
+	kfree(ctx);
+}
+
+/*
+ * Open file
+ */
+static int
+nfs_opendir(struct inode *inode, struct file *filp)
+{
+	int res = 0;
+	struct nfs_open_dir_context *ctx;
+
+	dfprintk(FILE, "NFS: open dir(%pD2)\n", filp);
+
+	nfs_inc_stats(inode, NFSIOS_VFSOPEN);
+
+	ctx = alloc_nfs_open_dir_context(inode, current_cred());
+	if (IS_ERR(ctx)) {
+		res = PTR_ERR(ctx);
+		goto out;
+	}
+	filp->private_data = ctx;
+out:
+	return res;
+}
+
+static int
+nfs_closedir(struct inode *inode, struct file *filp)
+{
+	put_nfs_open_dir_context(file_inode(filp), filp->private_data);
+	return 0;
+}
+
+struct nfs_cache_array_entry {
+	u64 cookie;
+	u64 ino;
+	struct qstr string;
+	unsigned char d_type;
+};
+
+struct nfs_cache_array {
+	int size;
+	int eof_index;
+	u64 last_cookie;
+	struct nfs_cache_array_entry array[];
+};
+
+typedef struct {
+	struct file	*file;
+	struct page	*page;
+	struct dir_context *ctx;
+	unsigned long	page_index;
+	u64		*dir_cookie;
+	u64		last_cookie;
+	loff_t		current_index;
+	loff_t		prev_index;
+
+	unsigned long	dir_verifier;
+	unsigned long	timestamp;
+	unsigned long	gencount;
+	unsigned int	cache_entry_index;
+	bool plus;
+	bool eof;
+} nfs_readdir_descriptor_t;
+
+static
+void nfs_readdir_init_array(struct page *page)
+{
+	struct nfs_cache_array *array;
+
+	array = kmap_atomic(page);
+	memset(array, 0, sizeof(struct nfs_cache_array));
+	array->eof_index = -1;
+	kunmap_atomic(array);
+}
+
+/*
+ * we are freeing strings created by nfs_add_to_readdir_array()
+ */
+static
+void nfs_readdir_clear_array(struct page *page)
+{
+	struct nfs_cache_array *array;
+	int i;
+
+	array = kmap_atomic(page);
+	for (i = 0; i < array->size; i++)
+		kfree(array->array[i].string.name);
+	array->size = 0;
+	kunmap_atomic(array);
+}
+
+/*
+ * the caller is responsible for freeing qstr.name
+ * when called by nfs_readdir_add_to_array, the strings will be freed in
+ * nfs_clear_readdir_array()
+ */
+static
+int nfs_readdir_make_qstr(struct qstr *string, const char *name, unsigned int len)
+{
+	string->len = len;
+	string->name = kmemdup_nul(name, len, GFP_KERNEL);
+	if (string->name == NULL)
+		return -ENOMEM;
+	/*
+	 * Avoid a kmemleak false positive. The pointer to the name is stored
+	 * in a page cache page which kmemleak does not scan.
+	 */
+	kmemleak_not_leak(string->name);
+	string->hash = full_name_hash(NULL, name, len);
+	return 0;
+}
+
+static
+int nfs_readdir_add_to_array(struct nfs_entry *entry, struct page *page)
+{
+	struct nfs_cache_array *array = kmap(page);
+	struct nfs_cache_array_entry *cache_entry;
+	int ret;
+
+	cache_entry = &array->array[array->size];
+
+	/* Check that this entry lies within the page bounds */
+	ret = -ENOSPC;
+	if ((char *)&cache_entry[1] - (char *)page_address(page) > PAGE_SIZE)
+		goto out;
+
+	cache_entry->cookie = entry->prev_cookie;
+	cache_entry->ino = entry->ino;
+	cache_entry->d_type = entry->d_type;
+	ret = nfs_readdir_make_qstr(&cache_entry->string, entry->name, entry->len);
+	if (ret)
+		goto out;
+	array->last_cookie = entry->cookie;
+	array->size++;
+	if (entry->eof != 0)
+		array->eof_index = array->size;
+out:
+	kunmap(page);
+	return ret;
+}
+
+static inline
+int is_32bit_api(void)
+{
+#ifdef CONFIG_COMPAT
+	return in_compat_syscall();
+#else
+	return (BITS_PER_LONG == 32);
+#endif
+}
+
+static
+bool nfs_readdir_use_cookie(const struct file *filp)
+{
+	if ((filp->f_mode & FMODE_32BITHASH) ||
+	    (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api()))
+		return false;
+	return true;
+}
+
+static
+int nfs_readdir_search_for_pos(struct nfs_cache_array *array, nfs_readdir_descriptor_t *desc)
+{
+	loff_t diff = desc->ctx->pos - desc->current_index;
+	unsigned int index;
+
+	if (diff < 0)
+		goto out_eof;
+	if (diff >= array->size) {
+		if (array->eof_index >= 0)
+			goto out_eof;
+		return -EAGAIN;
+	}
+
+	index = (unsigned int)diff;
+	*desc->dir_cookie = array->array[index].cookie;
+	desc->cache_entry_index = index;
+	return 0;
+out_eof:
+	desc->eof = true;
+	return -EBADCOOKIE;
+}
+
+static bool
+nfs_readdir_inode_mapping_valid(struct nfs_inode *nfsi)
+{
+	if (nfsi->cache_validity & (NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA))
+		return false;
+	smp_rmb();
+	return !test_bit(NFS_INO_INVALIDATING, &nfsi->flags);
+}
+
+static
+int nfs_readdir_search_for_cookie(struct nfs_cache_array *array, nfs_readdir_descriptor_t *desc)
+{
+	int i;
+	loff_t new_pos;
+	int status = -EAGAIN;
+
+	for (i = 0; i < array->size; i++) {
+		if (array->array[i].cookie == *desc->dir_cookie) {
+			struct nfs_inode *nfsi = NFS_I(file_inode(desc->file));
+			struct nfs_open_dir_context *ctx = desc->file->private_data;
+
+			new_pos = desc->current_index + i;
+			if (ctx->attr_gencount != nfsi->attr_gencount ||
+			    !nfs_readdir_inode_mapping_valid(nfsi)) {
+				ctx->duped = 0;
+				ctx->attr_gencount = nfsi->attr_gencount;
+			} else if (new_pos < desc->prev_index) {
+				if (ctx->duped > 0
+				    && ctx->dup_cookie == *desc->dir_cookie) {
+					if (printk_ratelimit()) {
+						pr_notice("NFS: directory %pD2 contains a readdir loop."
+								"Please contact your server vendor.  "
+								"The file: %.*s has duplicate cookie %llu\n",
+								desc->file, array->array[i].string.len,
+								array->array[i].string.name, *desc->dir_cookie);
+					}
+					status = -ELOOP;
+					goto out;
+				}
+				ctx->dup_cookie = *desc->dir_cookie;
+				ctx->duped = -1;
+			}
+			if (nfs_readdir_use_cookie(desc->file))
+				desc->ctx->pos = *desc->dir_cookie;
+			else
+				desc->ctx->pos = new_pos;
+			desc->prev_index = new_pos;
+			desc->cache_entry_index = i;
+			return 0;
+		}
+	}
+	if (array->eof_index >= 0) {
+		status = -EBADCOOKIE;
+		if (*desc->dir_cookie == array->last_cookie)
+			desc->eof = true;
+	}
+out:
+	return status;
+}
+
+static
+int nfs_readdir_search_array(nfs_readdir_descriptor_t *desc)
+{
+	struct nfs_cache_array *array;
+	int status;
+
+	array = kmap(desc->page);
+
+	if (*desc->dir_cookie == 0)
+		status = nfs_readdir_search_for_pos(array, desc);
+	else
+		status = nfs_readdir_search_for_cookie(array, desc);
+
+	if (status == -EAGAIN) {
+		desc->last_cookie = array->last_cookie;
+		desc->current_index += array->size;
+		desc->page_index++;
+	}
+	kunmap(desc->page);
+	return status;
+}
+
+/* Fill a page with xdr information before transferring to the cache page */
+static
+int nfs_readdir_xdr_filler(struct page **pages, nfs_readdir_descriptor_t *desc,
+			struct nfs_entry *entry, struct file *file, struct inode *inode)
+{
+	struct nfs_open_dir_context *ctx = file->private_data;
+	const struct cred *cred = ctx->cred;
+	unsigned long	timestamp, gencount;
+	int		error;
+
+ again:
+	timestamp = jiffies;
+	gencount = nfs_inc_attr_generation_counter();
+	desc->dir_verifier = nfs_save_change_attribute(inode);
+	error = NFS_PROTO(inode)->readdir(file_dentry(file), cred, entry->cookie, pages,
+					  NFS_SERVER(inode)->dtsize, desc->plus);
+	if (error < 0) {
+		/* We requested READDIRPLUS, but the server doesn't grok it */
+		if (error == -ENOTSUPP && desc->plus) {
+			NFS_SERVER(inode)->caps &= ~NFS_CAP_READDIRPLUS;
+			clear_bit(NFS_INO_ADVISE_RDPLUS, &NFS_I(inode)->flags);
+			desc->plus = false;
+			goto again;
+		}
+		goto error;
+	}
+	desc->timestamp = timestamp;
+	desc->gencount = gencount;
+error:
+	return error;
+}
+
+static int xdr_decode(nfs_readdir_descriptor_t *desc,
+		      struct nfs_entry *entry, struct xdr_stream *xdr)
+{
+	struct inode *inode = file_inode(desc->file);
+	int error;
+
+	error = NFS_PROTO(inode)->decode_dirent(xdr, entry, desc->plus);
+	if (error)
+		return error;
+	entry->fattr->time_start = desc->timestamp;
+	entry->fattr->gencount = desc->gencount;
+	return 0;
+}
+
+/* Match file and dirent using either filehandle or fileid
+ * Note: caller is responsible for checking the fsid
+ */
+static
+int nfs_same_file(struct dentry *dentry, struct nfs_entry *entry)
+{
+	struct inode *inode;
+	struct nfs_inode *nfsi;
+
+	if (d_really_is_negative(dentry))
+		return 0;
+
+	inode = d_inode(dentry);
+	if (is_bad_inode(inode) || NFS_STALE(inode))
+		return 0;
+
+	nfsi = NFS_I(inode);
+	if (entry->fattr->fileid != nfsi->fileid)
+		return 0;
+	if (entry->fh->size && nfs_compare_fh(entry->fh, &nfsi->fh) != 0)
+		return 0;
+	return 1;
+}
+
+static
+bool nfs_use_readdirplus(struct inode *dir, struct dir_context *ctx)
+{
+	if (!nfs_server_capable(dir, NFS_CAP_READDIRPLUS))
+		return false;
+	if (test_and_clear_bit(NFS_INO_ADVISE_RDPLUS, &NFS_I(dir)->flags))
+		return true;
+	if (ctx->pos == 0)
+		return true;
+	return false;
+}
+
+/*
+ * This function is called by the lookup and getattr code to request the
+ * use of readdirplus to accelerate any future lookups in the same
+ * directory.
+ */
+void nfs_advise_use_readdirplus(struct inode *dir)
+{
+	struct nfs_inode *nfsi = NFS_I(dir);
+
+	if (nfs_server_capable(dir, NFS_CAP_READDIRPLUS) &&
+	    !list_empty(&nfsi->open_files))
+		set_bit(NFS_INO_ADVISE_RDPLUS, &nfsi->flags);
+}
+
+/*
+ * This function is mainly for use by nfs_getattr().
+ *
+ * If this is an 'ls -l', we want to force use of readdirplus.
+ * Do this by checking if there is an active file descriptor
+ * and calling nfs_advise_use_readdirplus, then forcing a
+ * cache flush.
+ */
+void nfs_force_use_readdirplus(struct inode *dir)
+{
+	struct nfs_inode *nfsi = NFS_I(dir);
+
+	if (nfs_server_capable(dir, NFS_CAP_READDIRPLUS) &&
+	    !list_empty(&nfsi->open_files)) {
+		set_bit(NFS_INO_ADVISE_RDPLUS, &nfsi->flags);
+		invalidate_mapping_pages(dir->i_mapping,
+			nfsi->page_index + 1, -1);
+	}
+}
+
+static
+void nfs_prime_dcache(struct dentry *parent, struct nfs_entry *entry,
+		unsigned long dir_verifier)
+{
+	struct qstr filename = QSTR_INIT(entry->name, entry->len);
+	DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
+	struct dentry *dentry;
+	struct dentry *alias;
+	struct inode *inode;
+	int status;
+
+	if (!(entry->fattr->valid & NFS_ATTR_FATTR_FILEID))
+		return;
+	if (!(entry->fattr->valid & NFS_ATTR_FATTR_FSID))
+		return;
+	if (filename.len == 0)
+		return;
+	/* Validate that the name doesn't contain any illegal '\0' */
+	if (strnlen(filename.name, filename.len) != filename.len)
+		return;
+	/* ...or '/' */
+	if (strnchr(filename.name, filename.len, '/'))
+		return;
+	if (filename.name[0] == '.') {
+		if (filename.len == 1)
+			return;
+		if (filename.len == 2 && filename.name[1] == '.')
+			return;
+	}
+	filename.hash = full_name_hash(parent, filename.name, filename.len);
+
+	dentry = d_lookup(parent, &filename);
+again:
+	if (!dentry) {
+		dentry = d_alloc_parallel(parent, &filename, &wq);
+		if (IS_ERR(dentry))
+			return;
+	}
+	if (!d_in_lookup(dentry)) {
+		/* Is there a mountpoint here? If so, just exit */
+		if (!nfs_fsid_equal(&NFS_SB(dentry->d_sb)->fsid,
+					&entry->fattr->fsid))
+			goto out;
+		if (nfs_same_file(dentry, entry)) {
+			if (!entry->fh->size)
+				goto out;
+			nfs_set_verifier(dentry, dir_verifier);
+			status = nfs_refresh_inode(d_inode(dentry), entry->fattr);
+			if (!status)
+				nfs_setsecurity(d_inode(dentry), entry->fattr, entry->label);
+			goto out;
+		} else {
+			d_invalidate(dentry);
+			dput(dentry);
+			dentry = NULL;
+			goto again;
+		}
+	}
+	if (!entry->fh->size) {
+		d_lookup_done(dentry);
+		goto out;
+	}
+
+	inode = nfs_fhget(dentry->d_sb, entry->fh, entry->fattr, entry->label);
+	alias = d_splice_alias(inode, dentry);
+	d_lookup_done(dentry);
+	if (alias) {
+		if (IS_ERR(alias))
+			goto out;
+		dput(dentry);
+		dentry = alias;
+	}
+	nfs_set_verifier(dentry, dir_verifier);
+out:
+	dput(dentry);
+}
+
+/* Perform conversion from xdr to cache array */
+static
+int nfs_readdir_page_filler(nfs_readdir_descriptor_t *desc, struct nfs_entry *entry,
+				struct page **xdr_pages, struct page *page, unsigned int buflen)
+{
+	struct xdr_stream stream;
+	struct xdr_buf buf;
+	struct page *scratch;
+	struct nfs_cache_array *array;
+	unsigned int count = 0;
+	int status;
+
+	scratch = alloc_page(GFP_KERNEL);
+	if (scratch == NULL)
+		return -ENOMEM;
+
+	if (buflen == 0)
+		goto out_nopages;
+
+	xdr_init_decode_pages(&stream, &buf, xdr_pages, buflen);
+	xdr_set_scratch_buffer(&stream, page_address(scratch), PAGE_SIZE);
+
+	do {
+		if (entry->label)
+			entry->label->len = NFS4_MAXLABELLEN;
+
+		status = xdr_decode(desc, entry, &stream);
+		if (status != 0) {
+			if (status == -EAGAIN)
+				status = 0;
+			break;
+		}
+
+		count++;
+
+		if (desc->plus)
+			nfs_prime_dcache(file_dentry(desc->file), entry,
+					desc->dir_verifier);
+
+		status = nfs_readdir_add_to_array(entry, page);
+		if (status != 0)
+			break;
+	} while (!entry->eof);
+
+out_nopages:
+	if (count == 0 || (status == -EBADCOOKIE && entry->eof != 0)) {
+		array = kmap(page);
+		array->eof_index = array->size;
+		status = 0;
+		kunmap(page);
+	}
+
+	put_page(scratch);
+	return status;
+}
+
+static
+void nfs_readdir_free_pages(struct page **pages, unsigned int npages)
+{
+	unsigned int i;
+	for (i = 0; i < npages; i++)
+		put_page(pages[i]);
+}
+
+/*
+ * nfs_readdir_alloc_pages() will allocate pages that must be freed with a call
+ * to nfs_readdir_free_pages()
+ */
+static
+int nfs_readdir_alloc_pages(struct page **pages, unsigned int npages)
+{
+	unsigned int i;
+
+	for (i = 0; i < npages; i++) {
+		struct page *page = alloc_page(GFP_KERNEL);
+		if (page == NULL)
+			goto out_freepages;
+		pages[i] = page;
+	}
+	return 0;
+
+out_freepages:
+	nfs_readdir_free_pages(pages, i);
+	return -ENOMEM;
+}
+
+static
+int nfs_readdir_xdr_to_array(nfs_readdir_descriptor_t *desc, struct page *page, struct inode *inode)
+{
+	struct page *pages[NFS_MAX_READDIR_PAGES];
+	struct nfs_entry entry;
+	struct file	*file = desc->file;
+	struct nfs_cache_array *array;
+	int status = -ENOMEM;
+	unsigned int array_size = ARRAY_SIZE(pages);
+
+	nfs_readdir_init_array(page);
+
+	entry.prev_cookie = 0;
+	entry.cookie = desc->last_cookie;
+	entry.eof = 0;
+	entry.fh = nfs_alloc_fhandle();
+	entry.fattr = nfs_alloc_fattr();
+	entry.server = NFS_SERVER(inode);
+	if (entry.fh == NULL || entry.fattr == NULL)
+		goto out;
+
+	entry.label = nfs4_label_alloc(NFS_SERVER(inode), GFP_NOWAIT);
+	if (IS_ERR(entry.label)) {
+		status = PTR_ERR(entry.label);
+		goto out;
+	}
+
+	array = kmap(page);
+
+	status = nfs_readdir_alloc_pages(pages, array_size);
+	if (status < 0)
+		goto out_release_array;
+	do {
+		unsigned int pglen;
+		status = nfs_readdir_xdr_filler(pages, desc, &entry, file, inode);
+
+		if (status < 0)
+			break;
+		pglen = status;
+		status = nfs_readdir_page_filler(desc, &entry, pages, page, pglen);
+		if (status < 0) {
+			if (status == -ENOSPC)
+				status = 0;
+			break;
+		}
+	} while (array->eof_index < 0);
+
+	nfs_readdir_free_pages(pages, array_size);
+out_release_array:
+	kunmap(page);
+	nfs4_label_free(entry.label);
+out:
+	nfs_free_fattr(entry.fattr);
+	nfs_free_fhandle(entry.fh);
+	return status;
+}
+
+/*
+ * Now we cache directories properly, by converting xdr information
+ * to an array that can be used for lookups later.  This results in
+ * fewer cache pages, since we can store more information on each page.
+ * We only need to convert from xdr once so future lookups are much simpler
+ */
+static
+int nfs_readdir_filler(void *data, struct page* page)
+{
+	nfs_readdir_descriptor_t *desc = data;
+	struct inode	*inode = file_inode(desc->file);
+	int ret;
+
+	ret = nfs_readdir_xdr_to_array(desc, page, inode);
+	if (ret < 0)
+		goto error;
+	SetPageUptodate(page);
+
+	if (invalidate_inode_pages2_range(inode->i_mapping, page->index + 1, -1) < 0) {
+		/* Should never happen */
+		nfs_zap_mapping(inode, inode->i_mapping);
+	}
+	unlock_page(page);
+	return 0;
+ error:
+	nfs_readdir_clear_array(page);
+	unlock_page(page);
+	return ret;
+}
+
+static
+void cache_page_release(nfs_readdir_descriptor_t *desc)
+{
+	put_page(desc->page);
+	desc->page = NULL;
+}
+
+static
+struct page *get_cache_page(nfs_readdir_descriptor_t *desc)
+{
+	return read_cache_page(desc->file->f_mapping, desc->page_index,
+			nfs_readdir_filler, desc);
+}
+
+/*
+ * Returns 0 if desc->dir_cookie was found on page desc->page_index
+ * and locks the page to prevent removal from the page cache.
+ */
+static
+int find_and_lock_cache_page(nfs_readdir_descriptor_t *desc)
+{
+	struct inode *inode = file_inode(desc->file);
+	struct nfs_inode *nfsi = NFS_I(inode);
+	int res;
+
+	desc->page = get_cache_page(desc);
+	if (IS_ERR(desc->page))
+		return PTR_ERR(desc->page);
+	res = lock_page_killable(desc->page);
+	if (res != 0)
+		goto error;
+	res = -EAGAIN;
+	if (desc->page->mapping != NULL) {
+		res = nfs_readdir_search_array(desc);
+		if (res == 0) {
+			nfsi->page_index = desc->page_index;
+			return 0;
+		}
+	}
+	unlock_page(desc->page);
+error:
+	cache_page_release(desc);
+	return res;
+}
+
+/* Search for desc->dir_cookie from the beginning of the page cache */
+static inline
+int readdir_search_pagecache(nfs_readdir_descriptor_t *desc)
+{
+	int res;
+
+	if (desc->page_index == 0) {
+		desc->current_index = 0;
+		desc->prev_index = 0;
+		desc->last_cookie = 0;
+	}
+	do {
+		res = find_and_lock_cache_page(desc);
+	} while (res == -EAGAIN);
+	return res;
+}
+
+/*
+ * Once we've found the start of the dirent within a page: fill 'er up...
+ */
+static 
+int nfs_do_filldir(nfs_readdir_descriptor_t *desc)
+{
+	struct file	*file = desc->file;
+	int i = 0;
+	int res = 0;
+	struct nfs_cache_array *array = NULL;
+	struct nfs_open_dir_context *ctx = file->private_data;
+
+	array = kmap(desc->page);
+	for (i = desc->cache_entry_index; i < array->size; i++) {
+		struct nfs_cache_array_entry *ent;
+
+		ent = &array->array[i];
+		if (!dir_emit(desc->ctx, ent->string.name, ent->string.len,
+		    nfs_compat_user_ino64(ent->ino), ent->d_type)) {
+			desc->eof = true;
+			break;
+		}
+		if (i < (array->size-1))
+			*desc->dir_cookie = array->array[i+1].cookie;
+		else
+			*desc->dir_cookie = array->last_cookie;
+		if (nfs_readdir_use_cookie(file))
+			desc->ctx->pos = *desc->dir_cookie;
+		else
+			desc->ctx->pos++;
+		if (ctx->duped != 0)
+			ctx->duped = 1;
+	}
+	if (array->eof_index >= 0)
+		desc->eof = true;
+
+	kunmap(desc->page);
+	dfprintk(DIRCACHE, "NFS: nfs_do_filldir() filling ended @ cookie %Lu; returning = %d\n",
+			(unsigned long long)*desc->dir_cookie, res);
+	return res;
+}
+
+/*
+ * If we cannot find a cookie in our cache, we suspect that this is
+ * because it points to a deleted file, so we ask the server to return
+ * whatever it thinks is the next entry. We then feed this to filldir.
+ * If all goes well, we should then be able to find our way round the
+ * cache on the next call to readdir_search_pagecache();
+ *
+ * NOTE: we cannot add the anonymous page to the pagecache because
+ *	 the data it contains might not be page aligned. Besides,
+ *	 we should already have a complete representation of the
+ *	 directory in the page cache by the time we get here.
+ */
+static inline
+int uncached_readdir(nfs_readdir_descriptor_t *desc)
+{
+	struct page	*page = NULL;
+	int		status;
+	struct inode *inode = file_inode(desc->file);
+	struct nfs_open_dir_context *ctx = desc->file->private_data;
+
+	dfprintk(DIRCACHE, "NFS: uncached_readdir() searching for cookie %Lu\n",
+			(unsigned long long)*desc->dir_cookie);
+
+	page = alloc_page(GFP_HIGHUSER);
+	if (!page) {
+		status = -ENOMEM;
+		goto out;
+	}
+
+	desc->page_index = 0;
+	desc->last_cookie = *desc->dir_cookie;
+	desc->page = page;
+	ctx->duped = 0;
+
+	status = nfs_readdir_xdr_to_array(desc, page, inode);
+	if (status < 0)
+		goto out_release;
+
+	status = nfs_do_filldir(desc);
+
+ out_release:
+	nfs_readdir_clear_array(desc->page);
+	cache_page_release(desc);
+ out:
+	dfprintk(DIRCACHE, "NFS: %s: returns %d\n",
+			__func__, status);
+	return status;
+}
+
+/* The file offset position represents the dirent entry number.  A
+   last cookie cache takes care of the common case of reading the
+   whole directory.
+ */
+static int nfs_readdir(struct file *file, struct dir_context *ctx)
+{
+	struct dentry	*dentry = file_dentry(file);
+	struct inode	*inode = d_inode(dentry);
+	struct nfs_open_dir_context *dir_ctx = file->private_data;
+	nfs_readdir_descriptor_t my_desc = {
+		.file = file,
+		.ctx = ctx,
+		.dir_cookie = &dir_ctx->dir_cookie,
+		.plus = nfs_use_readdirplus(inode, ctx),
+	},
+			*desc = &my_desc;
+	int res = 0;
+
+	dfprintk(FILE, "NFS: readdir(%pD2) starting at cookie %llu\n",
+			file, (long long)ctx->pos);
+	nfs_inc_stats(inode, NFSIOS_VFSGETDENTS);
+
+	/*
+	 * ctx->pos points to the dirent entry number.
+	 * *desc->dir_cookie has the cookie for the next entry. We have
+	 * to either find the entry with the appropriate number or
+	 * revalidate the cookie.
+	 */
+	if (ctx->pos == 0 || nfs_attribute_cache_expired(inode))
+		res = nfs_revalidate_mapping(inode, file->f_mapping);
+	if (res < 0)
+		goto out;
+
+	do {
+		res = readdir_search_pagecache(desc);
+
+		if (res == -EBADCOOKIE) {
+			res = 0;
+			/* This means either end of directory */
+			if (*desc->dir_cookie && !desc->eof) {
+				/* Or that the server has 'lost' a cookie */
+				res = uncached_readdir(desc);
+				if (res == 0)
+					continue;
+			}
+			break;
+		}
+		if (res == -ETOOSMALL && desc->plus) {
+			clear_bit(NFS_INO_ADVISE_RDPLUS, &NFS_I(inode)->flags);
+			nfs_zap_caches(inode);
+			desc->page_index = 0;
+			desc->plus = false;
+			desc->eof = false;
+			continue;
+		}
+		if (res < 0)
+			break;
+
+		res = nfs_do_filldir(desc);
+		unlock_page(desc->page);
+		cache_page_release(desc);
+		if (res < 0)
+			break;
+	} while (!desc->eof);
+out:
+	if (res > 0)
+		res = 0;
+	dfprintk(FILE, "NFS: readdir(%pD2) returns %d\n", file, res);
+	return res;
+}
+
+static loff_t nfs_llseek_dir(struct file *filp, loff_t offset, int whence)
+{
+	struct nfs_open_dir_context *dir_ctx = filp->private_data;
+
+	dfprintk(FILE, "NFS: llseek dir(%pD2, %lld, %d)\n",
+			filp, offset, whence);
+
+	switch (whence) {
+	default:
+		return -EINVAL;
+	case SEEK_SET:
+		if (offset < 0)
+			return -EINVAL;
+		spin_lock(&filp->f_lock);
+		break;
+	case SEEK_CUR:
+		if (offset == 0)
+			return filp->f_pos;
+		spin_lock(&filp->f_lock);
+		offset += filp->f_pos;
+		if (offset < 0) {
+			spin_unlock(&filp->f_lock);
+			return -EINVAL;
+		}
+	}
+	if (offset != filp->f_pos) {
+		filp->f_pos = offset;
+		if (nfs_readdir_use_cookie(filp))
+			dir_ctx->dir_cookie = offset;
+		else
+			dir_ctx->dir_cookie = 0;
+		dir_ctx->duped = 0;
+	}
+	spin_unlock(&filp->f_lock);
+	return offset;
+}
+
+/*
+ * All directory operations under NFS are synchronous, so fsync()
+ * is a dummy operation.
+ */
+static int nfs_fsync_dir(struct file *filp, loff_t start, loff_t end,
+			 int datasync)
+{
+	dfprintk(FILE, "NFS: fsync dir(%pD2) datasync %d\n", filp, datasync);
+
+	nfs_inc_stats(file_inode(filp), NFSIOS_VFSFSYNC);
+	return 0;
+}
+
+/**
+ * nfs_force_lookup_revalidate - Mark the directory as having changed
+ * @dir: pointer to directory inode
+ *
+ * This forces the revalidation code in nfs_lookup_revalidate() to do a
+ * full lookup on all child dentries of 'dir' whenever a change occurs
+ * on the server that might have invalidated our dcache.
+ *
+ * Note that we reserve bit '0' as a tag to let us know when a dentry
+ * was revalidated while holding a delegation on its inode.
+ *
+ * The caller should be holding dir->i_lock
+ */
+void nfs_force_lookup_revalidate(struct inode *dir)
+{
+	NFS_I(dir)->cache_change_attribute += 2;
+}
+EXPORT_SYMBOL_GPL(nfs_force_lookup_revalidate);
+
+/**
+ * nfs_verify_change_attribute - Detects NFS remote directory changes
+ * @dir: pointer to parent directory inode
+ * @verf: previously saved change attribute
+ *
+ * Return "false" if the verifiers doesn't match the change attribute.
+ * This would usually indicate that the directory contents have changed on
+ * the server, and that any dentries need revalidating.
+ */
+static bool nfs_verify_change_attribute(struct inode *dir, unsigned long verf)
+{
+	return (verf & ~1UL) == nfs_save_change_attribute(dir);
+}
+
+static void nfs_set_verifier_delegated(unsigned long *verf)
+{
+	*verf |= 1UL;
+}
+
+#if IS_ENABLED(CONFIG_NFS_V4)
+static void nfs_unset_verifier_delegated(unsigned long *verf)
+{
+	*verf &= ~1UL;
+}
+#endif /* IS_ENABLED(CONFIG_NFS_V4) */
+
+static bool nfs_test_verifier_delegated(unsigned long verf)
+{
+	return verf & 1;
+}
+
+static bool nfs_verifier_is_delegated(struct dentry *dentry)
+{
+	return nfs_test_verifier_delegated(dentry->d_time);
+}
+
+static void nfs_set_verifier_locked(struct dentry *dentry, unsigned long verf)
+{
+	struct inode *inode = d_inode(dentry);
+	struct inode *dir = d_inode(dentry->d_parent);
+
+	if (!nfs_verify_change_attribute(dir, verf))
+		return;
+	if (inode && NFS_PROTO(inode)->have_delegation(inode, FMODE_READ))
+		nfs_set_verifier_delegated(&verf);
+	dentry->d_time = verf;
+}
+
+/**
+ * nfs_set_verifier - save a parent directory verifier in the dentry
+ * @dentry: pointer to dentry
+ * @verf: verifier to save
+ *
+ * Saves the parent directory verifier in @dentry. If the inode has
+ * a delegation, we also tag the dentry as having been revalidated
+ * while holding a delegation so that we know we don't have to
+ * look it up again after a directory change.
+ */
+void nfs_set_verifier(struct dentry *dentry, unsigned long verf)
+{
+
+	spin_lock(&dentry->d_lock);
+	nfs_set_verifier_locked(dentry, verf);
+	spin_unlock(&dentry->d_lock);
+}
+EXPORT_SYMBOL_GPL(nfs_set_verifier);
+
+#if IS_ENABLED(CONFIG_NFS_V4)
+/**
+ * nfs_clear_verifier_delegated - clear the dir verifier delegation tag
+ * @inode: pointer to inode
+ *
+ * Iterates through the dentries in the inode alias list and clears
+ * the tag used to indicate that the dentry has been revalidated
+ * while holding a delegation.
+ * This function is intended for use when the delegation is being
+ * returned or revoked.
+ */
+void nfs_clear_verifier_delegated(struct inode *inode)
+{
+	struct dentry *alias;
+
+	if (!inode)
+		return;
+	spin_lock(&inode->i_lock);
+	hlist_for_each_entry(alias, &inode->i_dentry, d_u.d_alias) {
+		spin_lock(&alias->d_lock);
+		nfs_unset_verifier_delegated(&alias->d_time);
+		spin_unlock(&alias->d_lock);
+	}
+	spin_unlock(&inode->i_lock);
+}
+EXPORT_SYMBOL_GPL(nfs_clear_verifier_delegated);
+#endif /* IS_ENABLED(CONFIG_NFS_V4) */
+
+/*
+ * A check for whether or not the parent directory has changed.
+ * In the case it has, we assume that the dentries are untrustworthy
+ * and may need to be looked up again.
+ * If rcu_walk prevents us from performing a full check, return 0.
+ */
+static int nfs_check_verifier(struct inode *dir, struct dentry *dentry,
+			      int rcu_walk)
+{
+	if (IS_ROOT(dentry))
+		return 1;
+	if (NFS_SERVER(dir)->flags & NFS_MOUNT_LOOKUP_CACHE_NONE)
+		return 0;
+	if (!nfs_verify_change_attribute(dir, dentry->d_time))
+		return 0;
+	/* Revalidate nfsi->cache_change_attribute before we declare a match */
+	if (nfs_mapping_need_revalidate_inode(dir)) {
+		if (rcu_walk)
+			return 0;
+		if (__nfs_revalidate_inode(NFS_SERVER(dir), dir) < 0)
+			return 0;
+	}
+	if (!nfs_verify_change_attribute(dir, dentry->d_time))
+		return 0;
+	return 1;
+}
+
+/*
+ * Use intent information to check whether or not we're going to do
+ * an O_EXCL create using this path component.
+ */
+static int nfs_is_exclusive_create(struct inode *dir, unsigned int flags)
+{
+	if (NFS_PROTO(dir)->version == 2)
+		return 0;
+	return flags & LOOKUP_EXCL;
+}
+
+/*
+ * Inode and filehandle revalidation for lookups.
+ *
+ * We force revalidation in the cases where the VFS sets LOOKUP_REVAL,
+ * or if the intent information indicates that we're about to open this
+ * particular file and the "nocto" mount flag is not set.
+ *
+ */
+static
+int nfs_lookup_verify_inode(struct inode *inode, unsigned int flags)
+{
+	struct nfs_server *server = NFS_SERVER(inode);
+	int ret;
+
+	if (IS_AUTOMOUNT(inode))
+		return 0;
+
+	if (flags & LOOKUP_OPEN) {
+		switch (inode->i_mode & S_IFMT) {
+		case S_IFREG:
+			/* A NFSv4 OPEN will revalidate later */
+			if (server->caps & NFS_CAP_ATOMIC_OPEN)
+				goto out;
+			fallthrough;
+		case S_IFDIR:
+			if (server->flags & NFS_MOUNT_NOCTO)
+				break;
+			/* NFS close-to-open cache consistency validation */
+			goto out_force;
+		}
+	}
+
+	/* VFS wants an on-the-wire revalidation */
+	if (flags & LOOKUP_REVAL)
+		goto out_force;
+out:
+	return (inode->i_nlink == 0) ? -ESTALE : 0;
+out_force:
+	if (flags & LOOKUP_RCU)
+		return -ECHILD;
+	ret = __nfs_revalidate_inode(server, inode);
+	if (ret != 0)
+		return ret;
+	goto out;
+}
+
+static void nfs_mark_dir_for_revalidate(struct inode *inode)
+{
+	struct nfs_inode *nfsi = NFS_I(inode);
+
+	spin_lock(&inode->i_lock);
+	nfsi->cache_validity |= NFS_INO_REVAL_PAGECACHE;
+	spin_unlock(&inode->i_lock);
+}
+
+/*
+ * We judge how long we want to trust negative
+ * dentries by looking at the parent inode mtime.
+ *
+ * If parent mtime has changed, we revalidate, else we wait for a
+ * period corresponding to the parent's attribute cache timeout value.
+ *
+ * If LOOKUP_RCU prevents us from performing a full check, return 1
+ * suggesting a reval is needed.
+ *
+ * Note that when creating a new file, or looking up a rename target,
+ * then it shouldn't be necessary to revalidate a negative dentry.
+ */
+static inline
+int nfs_neg_need_reval(struct inode *dir, struct dentry *dentry,
+		       unsigned int flags)
+{
+	if (flags & (LOOKUP_CREATE | LOOKUP_RENAME_TARGET))
+		return 0;
+	if (NFS_SERVER(dir)->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG)
+		return 1;
+	return !nfs_check_verifier(dir, dentry, flags & LOOKUP_RCU);
+}
+
+static int
+nfs_lookup_revalidate_done(struct inode *dir, struct dentry *dentry,
+			   struct inode *inode, int error)
+{
+	switch (error) {
+	case 1:
+		dfprintk(LOOKUPCACHE, "NFS: %s(%pd2) is valid\n",
+			__func__, dentry);
+		return 1;
+	case 0:
+		/*
+		 * We can't d_drop the root of a disconnected tree:
+		 * its d_hash is on the s_anon list and d_drop() would hide
+		 * it from shrink_dcache_for_unmount(), leading to busy
+		 * inodes on unmount and further oopses.
+		 */
+		if (inode && IS_ROOT(dentry))
+			return 1;
+		dfprintk(LOOKUPCACHE, "NFS: %s(%pd2) is invalid\n",
+				__func__, dentry);
+		return 0;
+	}
+	dfprintk(LOOKUPCACHE, "NFS: %s(%pd2) lookup returned error %d\n",
+				__func__, dentry, error);
+	return error;
+}
+
+static int
+nfs_lookup_revalidate_negative(struct inode *dir, struct dentry *dentry,
+			       unsigned int flags)
+{
+	int ret = 1;
+	if (nfs_neg_need_reval(dir, dentry, flags)) {
+		if (flags & LOOKUP_RCU)
+			return -ECHILD;
+		ret = 0;
+	}
+	return nfs_lookup_revalidate_done(dir, dentry, NULL, ret);
+}
+
+static int
+nfs_lookup_revalidate_delegated(struct inode *dir, struct dentry *dentry,
+				struct inode *inode)
+{
+	nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
+	return nfs_lookup_revalidate_done(dir, dentry, inode, 1);
+}
+
+static int
+nfs_lookup_revalidate_dentry(struct inode *dir, struct dentry *dentry,
+			     struct inode *inode)
+{
+	struct nfs_fh *fhandle;
+	struct nfs_fattr *fattr;
+	struct nfs4_label *label;
+	unsigned long dir_verifier;
+	int ret;
+
+	ret = -ENOMEM;
+	fhandle = nfs_alloc_fhandle();
+	fattr = nfs_alloc_fattr();
+	label = nfs4_label_alloc(NFS_SERVER(inode), GFP_KERNEL);
+	if (fhandle == NULL || fattr == NULL || IS_ERR(label))
+		goto out;
+
+	dir_verifier = nfs_save_change_attribute(dir);
+	ret = NFS_PROTO(dir)->lookup(dir, dentry, fhandle, fattr, label);
+	if (ret < 0) {
+		switch (ret) {
+		case -ESTALE:
+		case -ENOENT:
+			ret = 0;
+			break;
+		case -ETIMEDOUT:
+			if (NFS_SERVER(inode)->flags & NFS_MOUNT_SOFTREVAL)
+				ret = 1;
+		}
+		goto out;
+	}
+	ret = 0;
+	if (nfs_compare_fh(NFS_FH(inode), fhandle))
+		goto out;
+	if (nfs_refresh_inode(inode, fattr) < 0)
+		goto out;
+
+	nfs_setsecurity(inode, fattr, label);
+	nfs_set_verifier(dentry, dir_verifier);
+
+	/* set a readdirplus hint that we had a cache miss */
+	nfs_force_use_readdirplus(dir);
+	ret = 1;
+out:
+	nfs_free_fattr(fattr);
+	nfs_free_fhandle(fhandle);
+	nfs4_label_free(label);
+
+	/*
+	 * If the lookup failed despite the dentry change attribute being
+	 * a match, then we should revalidate the directory cache.
+	 */
+	if (!ret && nfs_verify_change_attribute(dir, dentry->d_time))
+		nfs_mark_dir_for_revalidate(dir);
+	return nfs_lookup_revalidate_done(dir, dentry, inode, ret);
+}
+
+/*
+ * This is called every time the dcache has a lookup hit,
+ * and we should check whether we can really trust that
+ * lookup.
+ *
+ * NOTE! The hit can be a negative hit too, don't assume
+ * we have an inode!
+ *
+ * If the parent directory is seen to have changed, we throw out the
+ * cached dentry and do a new lookup.
+ */
+static int
+nfs_do_lookup_revalidate(struct inode *dir, struct dentry *dentry,
+			 unsigned int flags)
+{
+	struct inode *inode;
+	int error;
+
+	nfs_inc_stats(dir, NFSIOS_DENTRYREVALIDATE);
+	inode = d_inode(dentry);
+
+	if (!inode)
+		return nfs_lookup_revalidate_negative(dir, dentry, flags);
+
+	if (is_bad_inode(inode)) {
+		dfprintk(LOOKUPCACHE, "%s: %pd2 has dud inode\n",
+				__func__, dentry);
+		goto out_bad;
+	}
+
+	if (nfs_verifier_is_delegated(dentry))
+		return nfs_lookup_revalidate_delegated(dir, dentry, inode);
+
+	/* Force a full look up iff the parent directory has changed */
+	if (!(flags & (LOOKUP_EXCL | LOOKUP_REVAL)) &&
+	    nfs_check_verifier(dir, dentry, flags & LOOKUP_RCU)) {
+		error = nfs_lookup_verify_inode(inode, flags);
+		if (error) {
+			if (error == -ESTALE)
+				nfs_mark_dir_for_revalidate(dir);
+			goto out_bad;
+		}
+		nfs_advise_use_readdirplus(dir);
+		goto out_valid;
+	}
+
+	if (flags & LOOKUP_RCU)
+		return -ECHILD;
+
+	if (NFS_STALE(inode))
+		goto out_bad;
+
+	trace_nfs_lookup_revalidate_enter(dir, dentry, flags);
+	error = nfs_lookup_revalidate_dentry(dir, dentry, inode);
+	trace_nfs_lookup_revalidate_exit(dir, dentry, flags, error);
+	return error;
+out_valid:
+	return nfs_lookup_revalidate_done(dir, dentry, inode, 1);
+out_bad:
+	if (flags & LOOKUP_RCU)
+		return -ECHILD;
+	return nfs_lookup_revalidate_done(dir, dentry, inode, 0);
+}
+
+static int
+__nfs_lookup_revalidate(struct dentry *dentry, unsigned int flags,
+			int (*reval)(struct inode *, struct dentry *, unsigned int))
+{
+	struct dentry *parent;
+	struct inode *dir;
+	int ret;
+
+	if (flags & LOOKUP_RCU) {
+		parent = READ_ONCE(dentry->d_parent);
+		dir = d_inode_rcu(parent);
+		if (!dir)
+			return -ECHILD;
+		ret = reval(dir, dentry, flags);
+		if (parent != READ_ONCE(dentry->d_parent))
+			return -ECHILD;
+	} else {
+		parent = dget_parent(dentry);
+		ret = reval(d_inode(parent), dentry, flags);
+		dput(parent);
+	}
+	return ret;
+}
+
+static int nfs_lookup_revalidate(struct dentry *dentry, unsigned int flags)
+{
+	return __nfs_lookup_revalidate(dentry, flags, nfs_do_lookup_revalidate);
+}
+
+/*
+ * A weaker form of d_revalidate for revalidating just the d_inode(dentry)
+ * when we don't really care about the dentry name. This is called when a
+ * pathwalk ends on a dentry that was not found via a normal lookup in the
+ * parent dir (e.g.: ".", "..", procfs symlinks or mountpoint traversals).
+ *
+ * In this situation, we just want to verify that the inode itself is OK
+ * since the dentry might have changed on the server.
+ */
+static int nfs_weak_revalidate(struct dentry *dentry, unsigned int flags)
+{
+	struct inode *inode = d_inode(dentry);
+	int error = 0;
+
+	/*
+	 * I believe we can only get a negative dentry here in the case of a
+	 * procfs-style symlink. Just assume it's correct for now, but we may
+	 * eventually need to do something more here.
+	 */
+	if (!inode) {
+		dfprintk(LOOKUPCACHE, "%s: %pd2 has negative inode\n",
+				__func__, dentry);
+		return 1;
+	}
+
+	if (is_bad_inode(inode)) {
+		dfprintk(LOOKUPCACHE, "%s: %pd2 has dud inode\n",
+				__func__, dentry);
+		return 0;
+	}
+
+	error = nfs_lookup_verify_inode(inode, flags);
+	dfprintk(LOOKUPCACHE, "NFS: %s: inode %lu is %s\n",
+			__func__, inode->i_ino, error ? "invalid" : "valid");
+	return !error;
+}
+
+/*
+ * This is called from dput() when d_count is going to 0.
+ */
+static int nfs_dentry_delete(const struct dentry *dentry)
+{
+	dfprintk(VFS, "NFS: dentry_delete(%pd2, %x)\n",
+		dentry, dentry->d_flags);
+
+	/* Unhash any dentry with a stale inode */
+	if (d_really_is_positive(dentry) && NFS_STALE(d_inode(dentry)))
+		return 1;
+
+	if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
+		/* Unhash it, so that ->d_iput() would be called */
+		return 1;
+	}
+	if (!(dentry->d_sb->s_flags & SB_ACTIVE)) {
+		/* Unhash it, so that ancestors of killed async unlink
+		 * files will be cleaned up during umount */
+		return 1;
+	}
+	return 0;
+
+}
+
+/* Ensure that we revalidate inode->i_nlink */
+static void nfs_drop_nlink(struct inode *inode)
+{
+	spin_lock(&inode->i_lock);
+	/* drop the inode if we're reasonably sure this is the last link */
+	if (inode->i_nlink > 0)
+		drop_nlink(inode);
+	NFS_I(inode)->attr_gencount = nfs_inc_attr_generation_counter();
+	NFS_I(inode)->cache_validity |= NFS_INO_INVALID_CHANGE
+		| NFS_INO_INVALID_CTIME
+		| NFS_INO_INVALID_OTHER
+		| NFS_INO_REVAL_FORCED;
+	spin_unlock(&inode->i_lock);
+}
+
+/*
+ * Called when the dentry loses inode.
+ * We use it to clean up silly-renamed files.
+ */
+static void nfs_dentry_iput(struct dentry *dentry, struct inode *inode)
+{
+	if (S_ISDIR(inode->i_mode))
+		/* drop any readdir cache as it could easily be old */
+		NFS_I(inode)->cache_validity |= NFS_INO_INVALID_DATA;
+
+	if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
+		nfs_complete_unlink(dentry, inode);
+		nfs_drop_nlink(inode);
+	}
+	iput(inode);
+}
+
+static void nfs_d_release(struct dentry *dentry)
+{
+	/* free cached devname value, if it survived that far */
+	if (unlikely(dentry->d_fsdata)) {
+		if (dentry->d_flags & DCACHE_NFSFS_RENAMED)
+			WARN_ON(1);
+		else
+			kfree(dentry->d_fsdata);
+	}
+}
+
+const struct dentry_operations nfs_dentry_operations = {
+	.d_revalidate	= nfs_lookup_revalidate,
+	.d_weak_revalidate	= nfs_weak_revalidate,
+	.d_delete	= nfs_dentry_delete,
+	.d_iput		= nfs_dentry_iput,
+	.d_automount	= nfs_d_automount,
+	.d_release	= nfs_d_release,
+};
+EXPORT_SYMBOL_GPL(nfs_dentry_operations);
+
+struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
+{
+	struct dentry *res;
+	struct inode *inode = NULL;
+	struct nfs_fh *fhandle = NULL;
+	struct nfs_fattr *fattr = NULL;
+	struct nfs4_label *label = NULL;
+	unsigned long dir_verifier;
+	int error;
+
+	dfprintk(VFS, "NFS: lookup(%pd2)\n", dentry);
+	nfs_inc_stats(dir, NFSIOS_VFSLOOKUP);
+
+	if (unlikely(dentry->d_name.len > NFS_SERVER(dir)->namelen))
+		return ERR_PTR(-ENAMETOOLONG);
+
+	/*
+	 * If we're doing an exclusive create, optimize away the lookup
+	 * but don't hash the dentry.
+	 */
+	if (nfs_is_exclusive_create(dir, flags) || flags & LOOKUP_RENAME_TARGET)
+		return NULL;
+
+	res = ERR_PTR(-ENOMEM);
+	fhandle = nfs_alloc_fhandle();
+	fattr = nfs_alloc_fattr();
+	if (fhandle == NULL || fattr == NULL)
+		goto out;
+
+	label = nfs4_label_alloc(NFS_SERVER(dir), GFP_NOWAIT);
+	if (IS_ERR(label))
+		goto out;
+
+	dir_verifier = nfs_save_change_attribute(dir);
+	trace_nfs_lookup_enter(dir, dentry, flags);
+	error = NFS_PROTO(dir)->lookup(dir, dentry, fhandle, fattr, label);
+	if (error == -ENOENT)
+		goto no_entry;
+	if (error < 0) {
+		res = ERR_PTR(error);
+		goto out_label;
+	}
+	inode = nfs_fhget(dentry->d_sb, fhandle, fattr, label);
+	res = ERR_CAST(inode);
+	if (IS_ERR(res))
+		goto out_label;
+
+	/* Notify readdir to use READDIRPLUS */
+	nfs_force_use_readdirplus(dir);
+
+no_entry:
+	res = d_splice_alias(inode, dentry);
+	if (res != NULL) {
+		if (IS_ERR(res))
+			goto out_label;
+		dentry = res;
+	}
+	nfs_set_verifier(dentry, dir_verifier);
+out_label:
+	trace_nfs_lookup_exit(dir, dentry, flags, error);
+	nfs4_label_free(label);
+out:
+	nfs_free_fattr(fattr);
+	nfs_free_fhandle(fhandle);
+	return res;
+}
+EXPORT_SYMBOL_GPL(nfs_lookup);
+
+#if IS_ENABLED(CONFIG_NFS_V4)
+static int nfs4_lookup_revalidate(struct dentry *, unsigned int);
+
+const struct dentry_operations nfs4_dentry_operations = {
+	.d_revalidate	= nfs4_lookup_revalidate,
+	.d_weak_revalidate	= nfs_weak_revalidate,
+	.d_delete	= nfs_dentry_delete,
+	.d_iput		= nfs_dentry_iput,
+	.d_automount	= nfs_d_automount,
+	.d_release	= nfs_d_release,
+};
+EXPORT_SYMBOL_GPL(nfs4_dentry_operations);
+
+static struct nfs_open_context *create_nfs_open_context(struct dentry *dentry, int open_flags, struct file *filp)
+{
+	return alloc_nfs_open_context(dentry, flags_to_mode(open_flags), filp);
+}
+
+static int do_open(struct inode *inode, struct file *filp)
+{
+	nfs_fscache_open_file(inode, filp);
+	return 0;
+}
+
+static int nfs_finish_open(struct nfs_open_context *ctx,
+			   struct dentry *dentry,
+			   struct file *file, unsigned open_flags)
+{
+	int err;
+
+	err = finish_open(file, dentry, do_open);
+	if (err)
+		goto out;
+	if (S_ISREG(file->f_path.dentry->d_inode->i_mode))
+		nfs_file_set_open_context(file, ctx);
+	else
+		err = -EOPENSTALE;
+out:
+	return err;
+}
+
+int nfs_atomic_open(struct inode *dir, struct dentry *dentry,
+		    struct file *file, unsigned open_flags,
+		    umode_t mode)
+{
+	DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
+	struct nfs_open_context *ctx;
+	struct dentry *res;
+	struct iattr attr = { .ia_valid = ATTR_OPEN };
+	struct inode *inode;
+	unsigned int lookup_flags = 0;
+	bool switched = false;
+	int created = 0;
+	int err;
+
+	/* Expect a negative dentry */
+	BUG_ON(d_inode(dentry));
+
+	dfprintk(VFS, "NFS: atomic_open(%s/%lu), %pd\n",
+			dir->i_sb->s_id, dir->i_ino, dentry);
+
+	err = nfs_check_flags(open_flags);
+	if (err)
+		return err;
+
+	/* NFS only supports OPEN on regular files */
+	if ((open_flags & O_DIRECTORY)) {
+		if (!d_in_lookup(dentry)) {
+			/*
+			 * Hashed negative dentry with O_DIRECTORY: dentry was
+			 * revalidated and is fine, no need to perform lookup
+			 * again
+			 */
+			return -ENOENT;
+		}
+		lookup_flags = LOOKUP_OPEN|LOOKUP_DIRECTORY;
+		goto no_open;
+	}
+
+	if (dentry->d_name.len > NFS_SERVER(dir)->namelen)
+		return -ENAMETOOLONG;
+
+	if (open_flags & O_CREAT) {
+		struct nfs_server *server = NFS_SERVER(dir);
+
+		if (!(server->attr_bitmask[2] & FATTR4_WORD2_MODE_UMASK))
+			mode &= ~current_umask();
+
+		attr.ia_valid |= ATTR_MODE;
+		attr.ia_mode = mode;
+	}
+	if (open_flags & O_TRUNC) {
+		attr.ia_valid |= ATTR_SIZE;
+		attr.ia_size = 0;
+	}
+
+	if (!(open_flags & O_CREAT) && !d_in_lookup(dentry)) {
+		d_drop(dentry);
+		switched = true;
+		dentry = d_alloc_parallel(dentry->d_parent,
+					  &dentry->d_name, &wq);
+		if (IS_ERR(dentry))
+			return PTR_ERR(dentry);
+		if (unlikely(!d_in_lookup(dentry)))
+			return finish_no_open(file, dentry);
+	}
+
+	ctx = create_nfs_open_context(dentry, open_flags, file);
+	err = PTR_ERR(ctx);
+	if (IS_ERR(ctx))
+		goto out;
+
+	trace_nfs_atomic_open_enter(dir, ctx, open_flags);
+	inode = NFS_PROTO(dir)->open_context(dir, ctx, open_flags, &attr, &created);
+	if (created)
+		file->f_mode |= FMODE_CREATED;
+	if (IS_ERR(inode)) {
+		err = PTR_ERR(inode);
+		trace_nfs_atomic_open_exit(dir, ctx, open_flags, err);
+		put_nfs_open_context(ctx);
+		d_drop(dentry);
+		switch (err) {
+		case -ENOENT:
+			d_splice_alias(NULL, dentry);
+			nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
+			break;
+		case -EISDIR:
+		case -ENOTDIR:
+			goto no_open;
+		case -ELOOP:
+			if (!(open_flags & O_NOFOLLOW))
+				goto no_open;
+			break;
+			/* case -EINVAL: */
+		default:
+			break;
+		}
+		goto out;
+	}
+
+	err = nfs_finish_open(ctx, ctx->dentry, file, open_flags);
+	trace_nfs_atomic_open_exit(dir, ctx, open_flags, err);
+	put_nfs_open_context(ctx);
+out:
+	if (unlikely(switched)) {
+		d_lookup_done(dentry);
+		dput(dentry);
+	}
+	return err;
+
+no_open:
+	res = nfs_lookup(dir, dentry, lookup_flags);
+	if (!res) {
+		inode = d_inode(dentry);
+		if ((lookup_flags & LOOKUP_DIRECTORY) && inode &&
+		    !(S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)))
+			res = ERR_PTR(-ENOTDIR);
+		else if (inode && S_ISREG(inode->i_mode))
+			res = ERR_PTR(-EOPENSTALE);
+	} else if (!IS_ERR(res)) {
+		inode = d_inode(res);
+		if ((lookup_flags & LOOKUP_DIRECTORY) && inode &&
+		    !(S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))) {
+			dput(res);
+			res = ERR_PTR(-ENOTDIR);
+		} else if (inode && S_ISREG(inode->i_mode)) {
+			dput(res);
+			res = ERR_PTR(-EOPENSTALE);
+		}
+	}
+	if (switched) {
+		d_lookup_done(dentry);
+		if (!res)
+			res = dentry;
+		else
+			dput(dentry);
+	}
+	if (IS_ERR(res))
+		return PTR_ERR(res);
+	return finish_no_open(file, res);
+}
+EXPORT_SYMBOL_GPL(nfs_atomic_open);
+
+static int
+nfs4_do_lookup_revalidate(struct inode *dir, struct dentry *dentry,
+			  unsigned int flags)
+{
+	struct inode *inode;
+
+	if (!(flags & LOOKUP_OPEN) || (flags & LOOKUP_DIRECTORY))
+		goto full_reval;
+	if (d_mountpoint(dentry))
+		goto full_reval;
+
+	inode = d_inode(dentry);
+
+	/* We can't create new files in nfs_open_revalidate(), so we
+	 * optimize away revalidation of negative dentries.
+	 */
+	if (inode == NULL)
+		goto full_reval;
+
+	if (nfs_verifier_is_delegated(dentry))
+		return nfs_lookup_revalidate_delegated(dir, dentry, inode);
+
+	/* NFS only supports OPEN on regular files */
+	if (!S_ISREG(inode->i_mode))
+		goto full_reval;
+
+	/* We cannot do exclusive creation on a positive dentry */
+	if (flags & (LOOKUP_EXCL | LOOKUP_REVAL))
+		goto reval_dentry;
+
+	/* Check if the directory changed */
+	if (!nfs_check_verifier(dir, dentry, flags & LOOKUP_RCU))
+		goto reval_dentry;
+
+	/* Let f_op->open() actually open (and revalidate) the file */
+	return 1;
+reval_dentry:
+	if (flags & LOOKUP_RCU)
+		return -ECHILD;
+	return nfs_lookup_revalidate_dentry(dir, dentry, inode);
+
+full_reval:
+	return nfs_do_lookup_revalidate(dir, dentry, flags);
+}
+
+static int nfs4_lookup_revalidate(struct dentry *dentry, unsigned int flags)
+{
+	return __nfs_lookup_revalidate(dentry, flags,
+			nfs4_do_lookup_revalidate);
+}
+
+#endif /* CONFIG_NFSV4 */
+
+struct dentry *
+nfs_add_or_obtain(struct dentry *dentry, struct nfs_fh *fhandle,
+				struct nfs_fattr *fattr,
+				struct nfs4_label *label)
+{
+	struct dentry *parent = dget_parent(dentry);
+	struct inode *dir = d_inode(parent);
+	struct inode *inode;
+	struct dentry *d;
+	int error;
+
+	d_drop(dentry);
+
+	if (fhandle->size == 0) {
+		error = NFS_PROTO(dir)->lookup(dir, dentry, fhandle, fattr, NULL);
+		if (error)
+			goto out_error;
+	}
+	nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
+	if (!(fattr->valid & NFS_ATTR_FATTR)) {
+		struct nfs_server *server = NFS_SB(dentry->d_sb);
+		error = server->nfs_client->rpc_ops->getattr(server, fhandle,
+				fattr, NULL, NULL);
+		if (error < 0)
+			goto out_error;
+	}
+	inode = nfs_fhget(dentry->d_sb, fhandle, fattr, label);
+	d = d_splice_alias(inode, dentry);
+out:
+	dput(parent);
+	return d;
+out_error:
+	d = ERR_PTR(error);
+	goto out;
+}
+EXPORT_SYMBOL_GPL(nfs_add_or_obtain);
+
+/*
+ * Code common to create, mkdir, and mknod.
+ */
+int nfs_instantiate(struct dentry *dentry, struct nfs_fh *fhandle,
+				struct nfs_fattr *fattr,
+				struct nfs4_label *label)
+{
+	struct dentry *d;
+
+	d = nfs_add_or_obtain(dentry, fhandle, fattr, label);
+	if (IS_ERR(d))
+		return PTR_ERR(d);
+
+	/* Callers don't care */
+	dput(d);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nfs_instantiate);
+
+/*
+ * Following a failed create operation, we drop the dentry rather
+ * than retain a negative dentry. This avoids a problem in the event
+ * that the operation succeeded on the server, but an error in the
+ * reply path made it appear to have failed.
+ */
+int nfs_create(struct inode *dir, struct dentry *dentry,
+		umode_t mode, bool excl)
+{
+	struct iattr attr;
+	int open_flags = excl ? O_CREAT | O_EXCL : O_CREAT;
+	int error;
+
+	dfprintk(VFS, "NFS: create(%s/%lu), %pd\n",
+			dir->i_sb->s_id, dir->i_ino, dentry);
+
+	attr.ia_mode = mode;
+	attr.ia_valid = ATTR_MODE;
+
+	trace_nfs_create_enter(dir, dentry, open_flags);
+	error = NFS_PROTO(dir)->create(dir, dentry, &attr, open_flags);
+	trace_nfs_create_exit(dir, dentry, open_flags, error);
+	if (error != 0)
+		goto out_err;
+	return 0;
+out_err:
+	d_drop(dentry);
+	return error;
+}
+EXPORT_SYMBOL_GPL(nfs_create);
+
+/*
+ * See comments for nfs_proc_create regarding failed operations.
+ */
+int
+nfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t rdev)
+{
+	struct iattr attr;
+	int status;
+
+	dfprintk(VFS, "NFS: mknod(%s/%lu), %pd\n",
+			dir->i_sb->s_id, dir->i_ino, dentry);
+
+	attr.ia_mode = mode;
+	attr.ia_valid = ATTR_MODE;
+
+	trace_nfs_mknod_enter(dir, dentry);
+	status = NFS_PROTO(dir)->mknod(dir, dentry, &attr, rdev);
+	trace_nfs_mknod_exit(dir, dentry, status);
+	if (status != 0)
+		goto out_err;
+	return 0;
+out_err:
+	d_drop(dentry);
+	return status;
+}
+EXPORT_SYMBOL_GPL(nfs_mknod);
+
+/*
+ * See comments for nfs_proc_create regarding failed operations.
+ */
+int nfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
+{
+	struct iattr attr;
+	int error;
+
+	dfprintk(VFS, "NFS: mkdir(%s/%lu), %pd\n",
+			dir->i_sb->s_id, dir->i_ino, dentry);
+
+	attr.ia_valid = ATTR_MODE;
+	attr.ia_mode = mode | S_IFDIR;
+
+	trace_nfs_mkdir_enter(dir, dentry);
+	error = NFS_PROTO(dir)->mkdir(dir, dentry, &attr);
+	trace_nfs_mkdir_exit(dir, dentry, error);
+	if (error != 0)
+		goto out_err;
+	return 0;
+out_err:
+	d_drop(dentry);
+	return error;
+}
+EXPORT_SYMBOL_GPL(nfs_mkdir);
+
+static void nfs_dentry_handle_enoent(struct dentry *dentry)
+{
+	if (simple_positive(dentry))
+		d_delete(dentry);
+}
+
+int nfs_rmdir(struct inode *dir, struct dentry *dentry)
+{
+	int error;
+
+	dfprintk(VFS, "NFS: rmdir(%s/%lu), %pd\n",
+			dir->i_sb->s_id, dir->i_ino, dentry);
+
+	trace_nfs_rmdir_enter(dir, dentry);
+	if (d_really_is_positive(dentry)) {
+		down_write(&NFS_I(d_inode(dentry))->rmdir_sem);
+		error = NFS_PROTO(dir)->rmdir(dir, &dentry->d_name);
+		/* Ensure the VFS deletes this inode */
+		switch (error) {
+		case 0:
+			clear_nlink(d_inode(dentry));
+			break;
+		case -ENOENT:
+			nfs_dentry_handle_enoent(dentry);
+		}
+		up_write(&NFS_I(d_inode(dentry))->rmdir_sem);
+	} else
+		error = NFS_PROTO(dir)->rmdir(dir, &dentry->d_name);
+	trace_nfs_rmdir_exit(dir, dentry, error);
+
+	return error;
+}
+EXPORT_SYMBOL_GPL(nfs_rmdir);
+
+/*
+ * Remove a file after making sure there are no pending writes,
+ * and after checking that the file has only one user. 
+ *
+ * We invalidate the attribute cache and free the inode prior to the operation
+ * to avoid possible races if the server reuses the inode.
+ */
+static int nfs_safe_remove(struct dentry *dentry)
+{
+	struct inode *dir = d_inode(dentry->d_parent);
+	struct inode *inode = d_inode(dentry);
+	int error = -EBUSY;
+		
+	dfprintk(VFS, "NFS: safe_remove(%pd2)\n", dentry);
+
+	/* If the dentry was sillyrenamed, we simply call d_delete() */
+	if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
+		error = 0;
+		goto out;
+	}
+
+	trace_nfs_remove_enter(dir, dentry);
+	if (inode != NULL) {
+		error = NFS_PROTO(dir)->remove(dir, dentry);
+		if (error == 0)
+			nfs_drop_nlink(inode);
+	} else
+		error = NFS_PROTO(dir)->remove(dir, dentry);
+	if (error == -ENOENT)
+		nfs_dentry_handle_enoent(dentry);
+	trace_nfs_remove_exit(dir, dentry, error);
+out:
+	return error;
+}
+
+/*  We do silly rename. In case sillyrename() returns -EBUSY, the inode
+ *  belongs to an active ".nfs..." file and we return -EBUSY.
+ *
+ *  If sillyrename() returns 0, we do nothing, otherwise we unlink.
+ */
+int nfs_unlink(struct inode *dir, struct dentry *dentry)
+{
+	int error;
+	int need_rehash = 0;
+
+	dfprintk(VFS, "NFS: unlink(%s/%lu, %pd)\n", dir->i_sb->s_id,
+		dir->i_ino, dentry);
+
+	trace_nfs_unlink_enter(dir, dentry);
+	spin_lock(&dentry->d_lock);
+	if (d_count(dentry) > 1) {
+		spin_unlock(&dentry->d_lock);
+		/* Start asynchronous writeout of the inode */
+		write_inode_now(d_inode(dentry), 0);
+		error = nfs_sillyrename(dir, dentry);
+		goto out;
+	}
+	if (!d_unhashed(dentry)) {
+		__d_drop(dentry);
+		need_rehash = 1;
+	}
+	spin_unlock(&dentry->d_lock);
+	error = nfs_safe_remove(dentry);
+	if (!error || error == -ENOENT) {
+		nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
+	} else if (need_rehash)
+		d_rehash(dentry);
+out:
+	trace_nfs_unlink_exit(dir, dentry, error);
+	return error;
+}
+EXPORT_SYMBOL_GPL(nfs_unlink);
+
+/*
+ * To create a symbolic link, most file systems instantiate a new inode,
+ * add a page to it containing the path, then write it out to the disk
+ * using prepare_write/commit_write.
+ *
+ * Unfortunately the NFS client can't create the in-core inode first
+ * because it needs a file handle to create an in-core inode (see
+ * fs/nfs/inode.c:nfs_fhget).  We only have a file handle *after* the
+ * symlink request has completed on the server.
+ *
+ * So instead we allocate a raw page, copy the symname into it, then do
+ * the SYMLINK request with the page as the buffer.  If it succeeds, we
+ * now have a new file handle and can instantiate an in-core NFS inode
+ * and move the raw page into its mapping.
+ */
+int nfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
+{
+	struct page *page;
+	char *kaddr;
+	struct iattr attr;
+	unsigned int pathlen = strlen(symname);
+	int error;
+
+	dfprintk(VFS, "NFS: symlink(%s/%lu, %pd, %s)\n", dir->i_sb->s_id,
+		dir->i_ino, dentry, symname);
+
+	if (pathlen > PAGE_SIZE)
+		return -ENAMETOOLONG;
+
+	attr.ia_mode = S_IFLNK | S_IRWXUGO;
+	attr.ia_valid = ATTR_MODE;
+
+	page = alloc_page(GFP_USER);
+	if (!page)
+		return -ENOMEM;
+
+	kaddr = page_address(page);
+	memcpy(kaddr, symname, pathlen);
+	if (pathlen < PAGE_SIZE)
+		memset(kaddr + pathlen, 0, PAGE_SIZE - pathlen);
+
+	trace_nfs_symlink_enter(dir, dentry);
+	error = NFS_PROTO(dir)->symlink(dir, dentry, page, pathlen, &attr);
+	trace_nfs_symlink_exit(dir, dentry, error);
+	if (error != 0) {
+		dfprintk(VFS, "NFS: symlink(%s/%lu, %pd, %s) error %d\n",
+			dir->i_sb->s_id, dir->i_ino,
+			dentry, symname, error);
+		d_drop(dentry);
+		__free_page(page);
+		return error;
+	}
+
+	/*
+	 * No big deal if we can't add this page to the page cache here.
+	 * READLINK will get the missing page from the server if needed.
+	 */
+	if (!add_to_page_cache_lru(page, d_inode(dentry)->i_mapping, 0,
+							GFP_KERNEL)) {
+		SetPageUptodate(page);
+		unlock_page(page);
+		/*
+		 * add_to_page_cache_lru() grabs an extra page refcount.
+		 * Drop it here to avoid leaking this page later.
+		 */
+		put_page(page);
+	} else
+		__free_page(page);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nfs_symlink);
+
+int
+nfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry)
+{
+	struct inode *inode = d_inode(old_dentry);
+	int error;
+
+	dfprintk(VFS, "NFS: link(%pd2 -> %pd2)\n",
+		old_dentry, dentry);
+
+	trace_nfs_link_enter(inode, dir, dentry);
+	d_drop(dentry);
+	if (S_ISREG(inode->i_mode))
+		nfs_sync_inode(inode);
+	error = NFS_PROTO(dir)->link(inode, dir, &dentry->d_name);
+	if (error == 0) {
+		ihold(inode);
+		d_add(dentry, inode);
+	}
+	trace_nfs_link_exit(inode, dir, dentry, error);
+	return error;
+}
+EXPORT_SYMBOL_GPL(nfs_link);
+
+/*
+ * RENAME
+ * FIXME: Some nfsds, like the Linux user space nfsd, may generate a
+ * different file handle for the same inode after a rename (e.g. when
+ * moving to a different directory). A fail-safe method to do so would
+ * be to look up old_dir/old_name, create a link to new_dir/new_name and
+ * rename the old file using the sillyrename stuff. This way, the original
+ * file in old_dir will go away when the last process iput()s the inode.
+ *
+ * FIXED.
+ * 
+ * It actually works quite well. One needs to have the possibility for
+ * at least one ".nfs..." file in each directory the file ever gets
+ * moved or linked to which happens automagically with the new
+ * implementation that only depends on the dcache stuff instead of
+ * using the inode layer
+ *
+ * Unfortunately, things are a little more complicated than indicated
+ * above. For a cross-directory move, we want to make sure we can get
+ * rid of the old inode after the operation.  This means there must be
+ * no pending writes (if it's a file), and the use count must be 1.
+ * If these conditions are met, we can drop the dentries before doing
+ * the rename.
+ */
+int nfs_rename(struct inode *old_dir, struct dentry *old_dentry,
+	       struct inode *new_dir, struct dentry *new_dentry,
+	       unsigned int flags)
+{
+	struct inode *old_inode = d_inode(old_dentry);
+	struct inode *new_inode = d_inode(new_dentry);
+	struct dentry *dentry = NULL, *rehash = NULL;
+	struct rpc_task *task;
+	int error = -EBUSY;
+
+	if (flags)
+		return -EINVAL;
+
+	dfprintk(VFS, "NFS: rename(%pd2 -> %pd2, ct=%d)\n",
+		 old_dentry, new_dentry,
+		 d_count(new_dentry));
+
+	trace_nfs_rename_enter(old_dir, old_dentry, new_dir, new_dentry);
+	/*
+	 * For non-directories, check whether the target is busy and if so,
+	 * make a copy of the dentry and then do a silly-rename. If the
+	 * silly-rename succeeds, the copied dentry is hashed and becomes
+	 * the new target.
+	 */
+	if (new_inode && !S_ISDIR(new_inode->i_mode)) {
+		/*
+		 * To prevent any new references to the target during the
+		 * rename, we unhash the dentry in advance.
+		 */
+		if (!d_unhashed(new_dentry)) {
+			d_drop(new_dentry);
+			rehash = new_dentry;
+		}
+
+		if (d_count(new_dentry) > 2) {
+			int err;
+
+			/* copy the target dentry's name */
+			dentry = d_alloc(new_dentry->d_parent,
+					 &new_dentry->d_name);
+			if (!dentry)
+				goto out;
+
+			/* silly-rename the existing target ... */
+			err = nfs_sillyrename(new_dir, new_dentry);
+			if (err)
+				goto out;
+
+			new_dentry = dentry;
+			rehash = NULL;
+			new_inode = NULL;
+		}
+	}
+
+	if (S_ISREG(old_inode->i_mode))
+		nfs_sync_inode(old_inode);
+	task = nfs_async_rename(old_dir, new_dir, old_dentry, new_dentry, NULL);
+	if (IS_ERR(task)) {
+		error = PTR_ERR(task);
+		goto out;
+	}
+
+	error = rpc_wait_for_completion_task(task);
+	if (error != 0) {
+		((struct nfs_renamedata *)task->tk_calldata)->cancelled = 1;
+		/* Paired with the atomic_dec_and_test() barrier in rpc_do_put_task() */
+		smp_wmb();
+	} else
+		error = task->tk_status;
+	rpc_put_task(task);
+	/* Ensure the inode attributes are revalidated */
+	if (error == 0) {
+		spin_lock(&old_inode->i_lock);
+		NFS_I(old_inode)->attr_gencount = nfs_inc_attr_generation_counter();
+		NFS_I(old_inode)->cache_validity |= NFS_INO_INVALID_CHANGE
+			| NFS_INO_INVALID_CTIME
+			| NFS_INO_REVAL_FORCED;
+		spin_unlock(&old_inode->i_lock);
+	}
+out:
+	if (rehash)
+		d_rehash(rehash);
+	trace_nfs_rename_exit(old_dir, old_dentry,
+			new_dir, new_dentry, error);
+	if (!error) {
+		if (new_inode != NULL)
+			nfs_drop_nlink(new_inode);
+		/*
+		 * The d_move() should be here instead of in an async RPC completion
+		 * handler because we need the proper locks to move the dentry.  If
+		 * we're interrupted by a signal, the async RPC completion handler
+		 * should mark the directories for revalidation.
+		 */
+		d_move(old_dentry, new_dentry);
+		nfs_set_verifier(old_dentry,
+					nfs_save_change_attribute(new_dir));
+	} else if (error == -ENOENT)
+		nfs_dentry_handle_enoent(old_dentry);
+
+	/* new dentry created? */
+	if (dentry)
+		dput(dentry);
+	return error;
+}
+EXPORT_SYMBOL_GPL(nfs_rename);
+
+static DEFINE_SPINLOCK(nfs_access_lru_lock);
+static LIST_HEAD(nfs_access_lru_list);
+static atomic_long_t nfs_access_nr_entries;
+
+static unsigned long nfs_access_max_cachesize = 4*1024*1024;
+module_param(nfs_access_max_cachesize, ulong, 0644);
+MODULE_PARM_DESC(nfs_access_max_cachesize, "NFS access maximum total cache length");
+
+static void nfs_access_free_entry(struct nfs_access_entry *entry)
+{
+	put_cred(entry->cred);
+	kfree_rcu(entry, rcu_head);
+	smp_mb__before_atomic();
+	atomic_long_dec(&nfs_access_nr_entries);
+	smp_mb__after_atomic();
+}
+
+static void nfs_access_free_list(struct list_head *head)
+{
+	struct nfs_access_entry *cache;
+
+	while (!list_empty(head)) {
+		cache = list_entry(head->next, struct nfs_access_entry, lru);
+		list_del(&cache->lru);
+		nfs_access_free_entry(cache);
+	}
+}
+
+static unsigned long
+nfs_do_access_cache_scan(unsigned int nr_to_scan)
+{
+	LIST_HEAD(head);
+	struct nfs_inode *nfsi, *next;
+	struct nfs_access_entry *cache;
+	long freed = 0;
+
+	spin_lock(&nfs_access_lru_lock);
+	list_for_each_entry_safe(nfsi, next, &nfs_access_lru_list, access_cache_inode_lru) {
+		struct inode *inode;
+
+		if (nr_to_scan-- == 0)
+			break;
+		inode = &nfsi->vfs_inode;
+		spin_lock(&inode->i_lock);
+		if (list_empty(&nfsi->access_cache_entry_lru))
+			goto remove_lru_entry;
+		cache = list_entry(nfsi->access_cache_entry_lru.next,
+				struct nfs_access_entry, lru);
+		list_move(&cache->lru, &head);
+		rb_erase(&cache->rb_node, &nfsi->access_cache);
+		freed++;
+		if (!list_empty(&nfsi->access_cache_entry_lru))
+			list_move_tail(&nfsi->access_cache_inode_lru,
+					&nfs_access_lru_list);
+		else {
+remove_lru_entry:
+			list_del_init(&nfsi->access_cache_inode_lru);
+			smp_mb__before_atomic();
+			clear_bit(NFS_INO_ACL_LRU_SET, &nfsi->flags);
+			smp_mb__after_atomic();
+		}
+		spin_unlock(&inode->i_lock);
+	}
+	spin_unlock(&nfs_access_lru_lock);
+	nfs_access_free_list(&head);
+	return freed;
+}
+
+unsigned long
+nfs_access_cache_scan(struct shrinker *shrink, struct shrink_control *sc)
+{
+	int nr_to_scan = sc->nr_to_scan;
+	gfp_t gfp_mask = sc->gfp_mask;
+
+	if ((gfp_mask & GFP_KERNEL) != GFP_KERNEL)
+		return SHRINK_STOP;
+	return nfs_do_access_cache_scan(nr_to_scan);
+}
+
+
+unsigned long
+nfs_access_cache_count(struct shrinker *shrink, struct shrink_control *sc)
+{
+	return vfs_pressure_ratio(atomic_long_read(&nfs_access_nr_entries));
+}
+
+static void
+nfs_access_cache_enforce_limit(void)
+{
+	long nr_entries = atomic_long_read(&nfs_access_nr_entries);
+	unsigned long diff;
+	unsigned int nr_to_scan;
+
+	if (nr_entries < 0 || nr_entries <= nfs_access_max_cachesize)
+		return;
+	nr_to_scan = 100;
+	diff = nr_entries - nfs_access_max_cachesize;
+	if (diff < nr_to_scan)
+		nr_to_scan = diff;
+	nfs_do_access_cache_scan(nr_to_scan);
+}
+
+static void __nfs_access_zap_cache(struct nfs_inode *nfsi, struct list_head *head)
+{
+	struct rb_root *root_node = &nfsi->access_cache;
+	struct rb_node *n;
+	struct nfs_access_entry *entry;
+
+	/* Unhook entries from the cache */
+	while ((n = rb_first(root_node)) != NULL) {
+		entry = rb_entry(n, struct nfs_access_entry, rb_node);
+		rb_erase(n, root_node);
+		list_move(&entry->lru, head);
+	}
+	nfsi->cache_validity &= ~NFS_INO_INVALID_ACCESS;
+}
+
+void nfs_access_zap_cache(struct inode *inode)
+{
+	LIST_HEAD(head);
+
+	if (test_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags) == 0)
+		return;
+	/* Remove from global LRU init */
+	spin_lock(&nfs_access_lru_lock);
+	if (test_and_clear_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags))
+		list_del_init(&NFS_I(inode)->access_cache_inode_lru);
+
+	spin_lock(&inode->i_lock);
+	__nfs_access_zap_cache(NFS_I(inode), &head);
+	spin_unlock(&inode->i_lock);
+	spin_unlock(&nfs_access_lru_lock);
+	nfs_access_free_list(&head);
+}
+EXPORT_SYMBOL_GPL(nfs_access_zap_cache);
+
+static struct nfs_access_entry *nfs_access_search_rbtree(struct inode *inode, const struct cred *cred)
+{
+	struct rb_node *n = NFS_I(inode)->access_cache.rb_node;
+
+	while (n != NULL) {
+		struct nfs_access_entry *entry =
+			rb_entry(n, struct nfs_access_entry, rb_node);
+		int cmp = cred_fscmp(cred, entry->cred);
+
+		if (cmp < 0)
+			n = n->rb_left;
+		else if (cmp > 0)
+			n = n->rb_right;
+		else
+			return entry;
+	}
+	return NULL;
+}
+
+static int nfs_access_get_cached_locked(struct inode *inode, const struct cred *cred, u32 *mask, bool may_block)
+{
+	struct nfs_inode *nfsi = NFS_I(inode);
+	struct nfs_access_entry *cache;
+	bool retry = true;
+	int err;
+
+	spin_lock(&inode->i_lock);
+	for(;;) {
+		if (nfsi->cache_validity & NFS_INO_INVALID_ACCESS)
+			goto out_zap;
+		cache = nfs_access_search_rbtree(inode, cred);
+		err = -ENOENT;
+		if (cache == NULL)
+			goto out;
+		/* Found an entry, is our attribute cache valid? */
+		if (!nfs_check_cache_invalid(inode, NFS_INO_INVALID_ACCESS))
+			break;
+		if (!retry)
+			break;
+		err = -ECHILD;
+		if (!may_block)
+			goto out;
+		spin_unlock(&inode->i_lock);
+		err = __nfs_revalidate_inode(NFS_SERVER(inode), inode);
+		if (err)
+			return err;
+		spin_lock(&inode->i_lock);
+		retry = false;
+	}
+	*mask = cache->mask;
+	list_move_tail(&cache->lru, &nfsi->access_cache_entry_lru);
+	err = 0;
+out:
+	spin_unlock(&inode->i_lock);
+	return err;
+out_zap:
+	spin_unlock(&inode->i_lock);
+	nfs_access_zap_cache(inode);
+	return -ENOENT;
+}
+
+static int nfs_access_get_cached_rcu(struct inode *inode, const struct cred *cred, u32 *mask)
+{
+	/* Only check the most recently returned cache entry,
+	 * but do it without locking.
+	 */
+	struct nfs_inode *nfsi = NFS_I(inode);
+	struct nfs_access_entry *cache;
+	int err = -ECHILD;
+	struct list_head *lh;
+
+	rcu_read_lock();
+	if (nfsi->cache_validity & NFS_INO_INVALID_ACCESS)
+		goto out;
+	lh = rcu_dereference(list_tail_rcu(&nfsi->access_cache_entry_lru));
+	cache = list_entry(lh, struct nfs_access_entry, lru);
+	if (lh == &nfsi->access_cache_entry_lru ||
+	    cred_fscmp(cred, cache->cred) != 0)
+		cache = NULL;
+	if (cache == NULL)
+		goto out;
+	if (nfs_check_cache_invalid(inode, NFS_INO_INVALID_ACCESS))
+		goto out;
+	*mask = cache->mask;
+	err = 0;
+out:
+	rcu_read_unlock();
+	return err;
+}
+
+int nfs_access_get_cached(struct inode *inode, const struct cred *cred,
+			  u32 *mask, bool may_block)
+{
+	int status;
+
+	status = nfs_access_get_cached_rcu(inode, cred, mask);
+	if (status != 0)
+		status = nfs_access_get_cached_locked(inode, cred, mask,
+		    may_block);
+
+	return status;
+}
+EXPORT_SYMBOL_GPL(nfs_access_get_cached);
+
+static void nfs_access_add_rbtree(struct inode *inode, struct nfs_access_entry *set)
+{
+	struct nfs_inode *nfsi = NFS_I(inode);
+	struct rb_root *root_node = &nfsi->access_cache;
+	struct rb_node **p = &root_node->rb_node;
+	struct rb_node *parent = NULL;
+	struct nfs_access_entry *entry;
+	int cmp;
+
+	spin_lock(&inode->i_lock);
+	while (*p != NULL) {
+		parent = *p;
+		entry = rb_entry(parent, struct nfs_access_entry, rb_node);
+		cmp = cred_fscmp(set->cred, entry->cred);
+
+		if (cmp < 0)
+			p = &parent->rb_left;
+		else if (cmp > 0)
+			p = &parent->rb_right;
+		else
+			goto found;
+	}
+	rb_link_node(&set->rb_node, parent, p);
+	rb_insert_color(&set->rb_node, root_node);
+	list_add_tail(&set->lru, &nfsi->access_cache_entry_lru);
+	spin_unlock(&inode->i_lock);
+	return;
+found:
+	rb_replace_node(parent, &set->rb_node, root_node);
+	list_add_tail(&set->lru, &nfsi->access_cache_entry_lru);
+	list_del(&entry->lru);
+	spin_unlock(&inode->i_lock);
+	nfs_access_free_entry(entry);
+}
+
+void nfs_access_add_cache(struct inode *inode, struct nfs_access_entry *set)
+{
+	struct nfs_access_entry *cache = kmalloc(sizeof(*cache), GFP_KERNEL);
+	if (cache == NULL)
+		return;
+	RB_CLEAR_NODE(&cache->rb_node);
+	cache->cred = get_cred(set->cred);
+	cache->mask = set->mask;
+
+	/* The above field assignments must be visible
+	 * before this item appears on the lru.  We cannot easily
+	 * use rcu_assign_pointer, so just force the memory barrier.
+	 */
+	smp_wmb();
+	nfs_access_add_rbtree(inode, cache);
+
+	/* Update accounting */
+	smp_mb__before_atomic();
+	atomic_long_inc(&nfs_access_nr_entries);
+	smp_mb__after_atomic();
+
+	/* Add inode to global LRU list */
+	if (!test_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags)) {
+		spin_lock(&nfs_access_lru_lock);
+		if (!test_and_set_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags))
+			list_add_tail(&NFS_I(inode)->access_cache_inode_lru,
+					&nfs_access_lru_list);
+		spin_unlock(&nfs_access_lru_lock);
+	}
+	nfs_access_cache_enforce_limit();
+}
+EXPORT_SYMBOL_GPL(nfs_access_add_cache);
+
+#define NFS_MAY_READ (NFS_ACCESS_READ)
+#define NFS_MAY_WRITE (NFS_ACCESS_MODIFY | \
+		NFS_ACCESS_EXTEND | \
+		NFS_ACCESS_DELETE)
+#define NFS_FILE_MAY_WRITE (NFS_ACCESS_MODIFY | \
+		NFS_ACCESS_EXTEND)
+#define NFS_DIR_MAY_WRITE NFS_MAY_WRITE
+#define NFS_MAY_LOOKUP (NFS_ACCESS_LOOKUP)
+#define NFS_MAY_EXECUTE (NFS_ACCESS_EXECUTE)
+static int
+nfs_access_calc_mask(u32 access_result, umode_t umode)
+{
+	int mask = 0;
+
+	if (access_result & NFS_MAY_READ)
+		mask |= MAY_READ;
+	if (S_ISDIR(umode)) {
+		if ((access_result & NFS_DIR_MAY_WRITE) == NFS_DIR_MAY_WRITE)
+			mask |= MAY_WRITE;
+		if ((access_result & NFS_MAY_LOOKUP) == NFS_MAY_LOOKUP)
+			mask |= MAY_EXEC;
+	} else if (S_ISREG(umode)) {
+		if ((access_result & NFS_FILE_MAY_WRITE) == NFS_FILE_MAY_WRITE)
+			mask |= MAY_WRITE;
+		if ((access_result & NFS_MAY_EXECUTE) == NFS_MAY_EXECUTE)
+			mask |= MAY_EXEC;
+	} else if (access_result & NFS_MAY_WRITE)
+			mask |= MAY_WRITE;
+	return mask;
+}
+
+void nfs_access_set_mask(struct nfs_access_entry *entry, u32 access_result)
+{
+	entry->mask = access_result;
+}
+EXPORT_SYMBOL_GPL(nfs_access_set_mask);
+
+static int nfs_do_access(struct inode *inode, const struct cred *cred, int mask)
+{
+	struct nfs_access_entry cache;
+	bool may_block = (mask & MAY_NOT_BLOCK) == 0;
+	int cache_mask = -1;
+	int status;
+
+	trace_nfs_access_enter(inode);
+
+	status = nfs_access_get_cached(inode, cred, &cache.mask, may_block);
+	if (status == 0)
+		goto out_cached;
+
+	status = -ECHILD;
+	if (!may_block)
+		goto out;
+
+	/*
+	 * Determine which access bits we want to ask for...
+	 */
+	cache.mask = NFS_ACCESS_READ | NFS_ACCESS_MODIFY | NFS_ACCESS_EXTEND;
+	if (nfs_server_capable(inode, NFS_CAP_XATTR)) {
+		cache.mask |= NFS_ACCESS_XAREAD | NFS_ACCESS_XAWRITE |
+		    NFS_ACCESS_XALIST;
+	}
+	if (S_ISDIR(inode->i_mode))
+		cache.mask |= NFS_ACCESS_DELETE | NFS_ACCESS_LOOKUP;
+	else
+		cache.mask |= NFS_ACCESS_EXECUTE;
+	cache.cred = cred;
+	status = NFS_PROTO(inode)->access(inode, &cache);
+	if (status != 0) {
+		if (status == -ESTALE) {
+			if (!S_ISDIR(inode->i_mode))
+				nfs_set_inode_stale(inode);
+			else
+				nfs_zap_caches(inode);
+		}
+		goto out;
+	}
+	nfs_access_add_cache(inode, &cache);
+out_cached:
+	cache_mask = nfs_access_calc_mask(cache.mask, inode->i_mode);
+	if ((mask & ~cache_mask & (MAY_READ | MAY_WRITE | MAY_EXEC)) != 0)
+		status = -EACCES;
+out:
+	trace_nfs_access_exit(inode, mask, cache_mask, status);
+	return status;
+}
+
+static int nfs_open_permission_mask(int openflags)
+{
+	int mask = 0;
+
+	if (openflags & __FMODE_EXEC) {
+		/* ONLY check exec rights */
+		mask = MAY_EXEC;
+	} else {
+		if ((openflags & O_ACCMODE) != O_WRONLY)
+			mask |= MAY_READ;
+		if ((openflags & O_ACCMODE) != O_RDONLY)
+			mask |= MAY_WRITE;
+	}
+
+	return mask;
+}
+
+int nfs_may_open(struct inode *inode, const struct cred *cred, int openflags)
+{
+	return nfs_do_access(inode, cred, nfs_open_permission_mask(openflags));
+}
+EXPORT_SYMBOL_GPL(nfs_may_open);
+
+static int nfs_execute_ok(struct inode *inode, int mask)
+{
+	struct nfs_server *server = NFS_SERVER(inode);
+	int ret = 0;
+
+	if (S_ISDIR(inode->i_mode))
+		return 0;
+	if (nfs_check_cache_invalid(inode, NFS_INO_INVALID_OTHER)) {
+		if (mask & MAY_NOT_BLOCK)
+			return -ECHILD;
+		ret = __nfs_revalidate_inode(server, inode);
+	}
+	if (ret == 0 && !execute_ok(inode))
+		ret = -EACCES;
+	return ret;
+}
+
+int nfs_permission(struct inode *inode, int mask)
+{
+	const struct cred *cred = current_cred();
+	int res = 0;
+
+	nfs_inc_stats(inode, NFSIOS_VFSACCESS);
+
+	if ((mask & (MAY_READ | MAY_WRITE | MAY_EXEC)) == 0)
+		goto out;
+	/* Is this sys_access() ? */
+	if (mask & (MAY_ACCESS | MAY_CHDIR))
+		goto force_lookup;
+
+	switch (inode->i_mode & S_IFMT) {
+		case S_IFLNK:
+			goto out;
+		case S_IFREG:
+			if ((mask & MAY_OPEN) &&
+			   nfs_server_capable(inode, NFS_CAP_ATOMIC_OPEN))
+				return 0;
+			break;
+		case S_IFDIR:
+			/*
+			 * Optimize away all write operations, since the server
+			 * will check permissions when we perform the op.
+			 */
+			if ((mask & MAY_WRITE) && !(mask & MAY_READ))
+				goto out;
+	}
+
+force_lookup:
+	if (!NFS_PROTO(inode)->access)
+		goto out_notsup;
+
+	res = nfs_do_access(inode, cred, mask);
+out:
+	if (!res && (mask & MAY_EXEC))
+		res = nfs_execute_ok(inode, mask);
+
+	dfprintk(VFS, "NFS: permission(%s/%lu), mask=0x%x, res=%d\n",
+		inode->i_sb->s_id, inode->i_ino, mask, res);
+	return res;
+out_notsup:
+	if (mask & MAY_NOT_BLOCK)
+		return -ECHILD;
+
+	res = nfs_revalidate_inode(NFS_SERVER(inode), inode);
+	if (res == 0)
+		res = generic_permission(inode, mask);
+	goto out;
+}
+EXPORT_SYMBOL_GPL(nfs_permission);
+
+/*
+ * Local variables:
+ *  version-control: t
+ *  kept-new-versions: 5
+ * End:
+ */
diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
new file mode 100644
index 000000000..5d86ffa72
--- /dev/null
+++ b/fs/nfs/direct.c
@@ -0,0 +1,1034 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * linux/fs/nfs/direct.c
+ *
+ * Copyright (C) 2003 by Chuck Lever <cel@netapp.com>
+ *
+ * High-performance uncached I/O for the Linux NFS client
+ *
+ * There are important applications whose performance or correctness
+ * depends on uncached access to file data.  Database clusters
+ * (multiple copies of the same instance running on separate hosts)
+ * implement their own cache coherency protocol that subsumes file
+ * system cache protocols.  Applications that process datasets
+ * considerably larger than the client's memory do not always benefit
+ * from a local cache.  A streaming video server, for instance, has no
+ * need to cache the contents of a file.
+ *
+ * When an application requests uncached I/O, all read and write requests
+ * are made directly to the server; data stored or fetched via these
+ * requests is not cached in the Linux page cache.  The client does not
+ * correct unaligned requests from applications.  All requested bytes are
+ * held on permanent storage before a direct write system call returns to
+ * an application.
+ *
+ * Solaris implements an uncached I/O facility called directio() that
+ * is used for backups and sequential I/O to very large files.  Solaris
+ * also supports uncaching whole NFS partitions with "-o forcedirectio,"
+ * an undocumented mount option.
+ *
+ * Designed by Jeff Kimmel, Chuck Lever, and Trond Myklebust, with
+ * help from Andrew Morton.
+ *
+ * 18 Dec 2001	Initial implementation for 2.4  --cel
+ * 08 Jul 2002	Version for 2.4.19, with bug fixes --trondmy
+ * 08 Jun 2003	Port to 2.5 APIs  --cel
+ * 31 Mar 2004	Handle direct I/O without VFS support  --cel
+ * 15 Sep 2004	Parallel async reads  --cel
+ * 04 May 2005	support O_DIRECT with aio  --cel
+ *
+ */
+
+#include <linux/errno.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/file.h>
+#include <linux/pagemap.h>
+#include <linux/kref.h>
+#include <linux/slab.h>
+#include <linux/task_io_accounting_ops.h>
+#include <linux/module.h>
+
+#include <linux/nfs_fs.h>
+#include <linux/nfs_page.h>
+#include <linux/sunrpc/clnt.h>
+
+#include <linux/uaccess.h>
+#include <linux/atomic.h>
+
+#include "internal.h"
+#include "iostat.h"
+#include "pnfs.h"
+
+#define NFSDBG_FACILITY		NFSDBG_VFS
+
+static struct kmem_cache *nfs_direct_cachep;
+
+struct nfs_direct_req {
+	struct kref		kref;		/* release manager */
+
+	/* I/O parameters */
+	struct nfs_open_context	*ctx;		/* file open context info */
+	struct nfs_lock_context *l_ctx;		/* Lock context info */
+	struct kiocb *		iocb;		/* controlling i/o request */
+	struct inode *		inode;		/* target file of i/o */
+
+	/* completion state */
+	atomic_t		io_count;	/* i/os we're waiting for */
+	spinlock_t		lock;		/* protect completion state */
+
+	loff_t			io_start;	/* Start offset for I/O */
+	ssize_t			count,		/* bytes actually processed */
+				max_count,	/* max expected count */
+				bytes_left,	/* bytes left to be sent */
+				error;		/* any reported error */
+	struct completion	completion;	/* wait for i/o completion */
+
+	/* commit state */
+	struct nfs_mds_commit_info mds_cinfo;	/* Storage for cinfo */
+	struct pnfs_ds_commit_info ds_cinfo;	/* Storage for cinfo */
+	struct work_struct	work;
+	int			flags;
+	/* for write */
+#define NFS_ODIRECT_DO_COMMIT		(1)	/* an unstable reply was received */
+#define NFS_ODIRECT_RESCHED_WRITES	(2)	/* write verification failed */
+	/* for read */
+#define NFS_ODIRECT_SHOULD_DIRTY	(3)	/* dirty user-space page after read */
+#define NFS_ODIRECT_DONE		INT_MAX	/* write verification failed */
+};
+
+static const struct nfs_pgio_completion_ops nfs_direct_write_completion_ops;
+static const struct nfs_commit_completion_ops nfs_direct_commit_completion_ops;
+static void nfs_direct_write_complete(struct nfs_direct_req *dreq);
+static void nfs_direct_write_schedule_work(struct work_struct *work);
+
+static inline void get_dreq(struct nfs_direct_req *dreq)
+{
+	atomic_inc(&dreq->io_count);
+}
+
+static inline int put_dreq(struct nfs_direct_req *dreq)
+{
+	return atomic_dec_and_test(&dreq->io_count);
+}
+
+static void
+nfs_direct_handle_truncated(struct nfs_direct_req *dreq,
+			    const struct nfs_pgio_header *hdr,
+			    ssize_t dreq_len)
+{
+	if (!(test_bit(NFS_IOHDR_ERROR, &hdr->flags) ||
+	      test_bit(NFS_IOHDR_EOF, &hdr->flags)))
+		return;
+	if (dreq->max_count >= dreq_len) {
+		dreq->max_count = dreq_len;
+		if (dreq->count > dreq_len)
+			dreq->count = dreq_len;
+
+		if (test_bit(NFS_IOHDR_ERROR, &hdr->flags))
+			dreq->error = hdr->error;
+		else /* Clear outstanding error if this is EOF */
+			dreq->error = 0;
+	}
+}
+
+static void
+nfs_direct_count_bytes(struct nfs_direct_req *dreq,
+		       const struct nfs_pgio_header *hdr)
+{
+	loff_t hdr_end = hdr->io_start + hdr->good_bytes;
+	ssize_t dreq_len = 0;
+
+	if (hdr_end > dreq->io_start)
+		dreq_len = hdr_end - dreq->io_start;
+
+	nfs_direct_handle_truncated(dreq, hdr, dreq_len);
+
+	if (dreq_len > dreq->max_count)
+		dreq_len = dreq->max_count;
+
+	if (dreq->count < dreq_len)
+		dreq->count = dreq_len;
+}
+
+/**
+ * nfs_direct_IO - NFS address space operation for direct I/O
+ * @iocb: target I/O control block
+ * @iter: I/O buffer
+ *
+ * The presence of this routine in the address space ops vector means
+ * the NFS client supports direct I/O. However, for most direct IO, we
+ * shunt off direct read and write requests before the VFS gets them,
+ * so this method is only ever called for swap.
+ */
+ssize_t nfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
+{
+	struct inode *inode = iocb->ki_filp->f_mapping->host;
+
+	/* we only support swap file calling nfs_direct_IO */
+	if (!IS_SWAPFILE(inode))
+		return 0;
+
+	VM_BUG_ON(iov_iter_count(iter) != PAGE_SIZE);
+
+	if (iov_iter_rw(iter) == READ)
+		return nfs_file_direct_read(iocb, iter, true);
+	return nfs_file_direct_write(iocb, iter, true);
+}
+
+static void nfs_direct_release_pages(struct page **pages, unsigned int npages)
+{
+	unsigned int i;
+	for (i = 0; i < npages; i++)
+		put_page(pages[i]);
+}
+
+void nfs_init_cinfo_from_dreq(struct nfs_commit_info *cinfo,
+			      struct nfs_direct_req *dreq)
+{
+	cinfo->inode = dreq->inode;
+	cinfo->mds = &dreq->mds_cinfo;
+	cinfo->ds = &dreq->ds_cinfo;
+	cinfo->dreq = dreq;
+	cinfo->completion_ops = &nfs_direct_commit_completion_ops;
+}
+
+static inline struct nfs_direct_req *nfs_direct_req_alloc(void)
+{
+	struct nfs_direct_req *dreq;
+
+	dreq = kmem_cache_zalloc(nfs_direct_cachep, GFP_KERNEL);
+	if (!dreq)
+		return NULL;
+
+	kref_init(&dreq->kref);
+	kref_get(&dreq->kref);
+	init_completion(&dreq->completion);
+	INIT_LIST_HEAD(&dreq->mds_cinfo.list);
+	pnfs_init_ds_commit_info(&dreq->ds_cinfo);
+	INIT_WORK(&dreq->work, nfs_direct_write_schedule_work);
+	spin_lock_init(&dreq->lock);
+
+	return dreq;
+}
+
+static void nfs_direct_req_free(struct kref *kref)
+{
+	struct nfs_direct_req *dreq = container_of(kref, struct nfs_direct_req, kref);
+
+	pnfs_release_ds_info(&dreq->ds_cinfo, dreq->inode);
+	if (dreq->l_ctx != NULL)
+		nfs_put_lock_context(dreq->l_ctx);
+	if (dreq->ctx != NULL)
+		put_nfs_open_context(dreq->ctx);
+	kmem_cache_free(nfs_direct_cachep, dreq);
+}
+
+static void nfs_direct_req_release(struct nfs_direct_req *dreq)
+{
+	kref_put(&dreq->kref, nfs_direct_req_free);
+}
+
+ssize_t nfs_dreq_bytes_left(struct nfs_direct_req *dreq)
+{
+	return dreq->bytes_left;
+}
+EXPORT_SYMBOL_GPL(nfs_dreq_bytes_left);
+
+/*
+ * Collects and returns the final error value/byte-count.
+ */
+static ssize_t nfs_direct_wait(struct nfs_direct_req *dreq)
+{
+	ssize_t result = -EIOCBQUEUED;
+
+	/* Async requests don't wait here */
+	if (dreq->iocb)
+		goto out;
+
+	result = wait_for_completion_killable(&dreq->completion);
+
+	if (!result) {
+		result = dreq->count;
+		WARN_ON_ONCE(dreq->count < 0);
+	}
+	if (!result)
+		result = dreq->error;
+
+out:
+	return (ssize_t) result;
+}
+
+/*
+ * Synchronous I/O uses a stack-allocated iocb.  Thus we can't trust
+ * the iocb is still valid here if this is a synchronous request.
+ */
+static void nfs_direct_complete(struct nfs_direct_req *dreq)
+{
+	struct inode *inode = dreq->inode;
+
+	inode_dio_end(inode);
+
+	if (dreq->iocb) {
+		long res = (long) dreq->error;
+		if (dreq->count != 0) {
+			res = (long) dreq->count;
+			WARN_ON_ONCE(dreq->count < 0);
+		}
+		dreq->iocb->ki_complete(dreq->iocb, res, 0);
+	}
+
+	complete(&dreq->completion);
+
+	nfs_direct_req_release(dreq);
+}
+
+static void nfs_direct_read_completion(struct nfs_pgio_header *hdr)
+{
+	unsigned long bytes = 0;
+	struct nfs_direct_req *dreq = hdr->dreq;
+
+	spin_lock(&dreq->lock);
+	if (test_bit(NFS_IOHDR_REDO, &hdr->flags)) {
+		spin_unlock(&dreq->lock);
+		goto out_put;
+	}
+
+	nfs_direct_count_bytes(dreq, hdr);
+	spin_unlock(&dreq->lock);
+
+	while (!list_empty(&hdr->pages)) {
+		struct nfs_page *req = nfs_list_entry(hdr->pages.next);
+		struct page *page = req->wb_page;
+
+		if (!PageCompound(page) && bytes < hdr->good_bytes &&
+		    (dreq->flags == NFS_ODIRECT_SHOULD_DIRTY))
+			set_page_dirty(page);
+		bytes += req->wb_bytes;
+		nfs_list_remove_request(req);
+		nfs_release_request(req);
+	}
+out_put:
+	if (put_dreq(dreq))
+		nfs_direct_complete(dreq);
+	hdr->release(hdr);
+}
+
+static void nfs_read_sync_pgio_error(struct list_head *head, int error)
+{
+	struct nfs_page *req;
+
+	while (!list_empty(head)) {
+		req = nfs_list_entry(head->next);
+		nfs_list_remove_request(req);
+		nfs_release_request(req);
+	}
+}
+
+static void nfs_direct_pgio_init(struct nfs_pgio_header *hdr)
+{
+	get_dreq(hdr->dreq);
+}
+
+static const struct nfs_pgio_completion_ops nfs_direct_read_completion_ops = {
+	.error_cleanup = nfs_read_sync_pgio_error,
+	.init_hdr = nfs_direct_pgio_init,
+	.completion = nfs_direct_read_completion,
+};
+
+/*
+ * For each rsize'd chunk of the user's buffer, dispatch an NFS READ
+ * operation.  If nfs_readdata_alloc() or get_user_pages() fails,
+ * bail and stop sending more reads.  Read length accounting is
+ * handled automatically by nfs_direct_read_result().  Otherwise, if
+ * no requests have been sent, just return an error.
+ */
+
+static ssize_t nfs_direct_read_schedule_iovec(struct nfs_direct_req *dreq,
+					      struct iov_iter *iter,
+					      loff_t pos)
+{
+	struct nfs_pageio_descriptor desc;
+	struct inode *inode = dreq->inode;
+	ssize_t result = -EINVAL;
+	size_t requested_bytes = 0;
+	size_t rsize = max_t(size_t, NFS_SERVER(inode)->rsize, PAGE_SIZE);
+
+	nfs_pageio_init_read(&desc, dreq->inode, false,
+			     &nfs_direct_read_completion_ops);
+	get_dreq(dreq);
+	desc.pg_dreq = dreq;
+	inode_dio_begin(inode);
+
+	while (iov_iter_count(iter)) {
+		struct page **pagevec;
+		size_t bytes;
+		size_t pgbase;
+		unsigned npages, i;
+
+		result = iov_iter_get_pages_alloc(iter, &pagevec, 
+						  rsize, &pgbase);
+		if (result < 0)
+			break;
+	
+		bytes = result;
+		iov_iter_advance(iter, bytes);
+		npages = (result + pgbase + PAGE_SIZE - 1) / PAGE_SIZE;
+		for (i = 0; i < npages; i++) {
+			struct nfs_page *req;
+			unsigned int req_len = min_t(size_t, bytes, PAGE_SIZE - pgbase);
+			/* XXX do we need to do the eof zeroing found in async_filler? */
+			req = nfs_create_request(dreq->ctx, pagevec[i],
+						 pgbase, req_len);
+			if (IS_ERR(req)) {
+				result = PTR_ERR(req);
+				break;
+			}
+			req->wb_index = pos >> PAGE_SHIFT;
+			req->wb_offset = pos & ~PAGE_MASK;
+			if (!nfs_pageio_add_request(&desc, req)) {
+				result = desc.pg_error;
+				nfs_release_request(req);
+				break;
+			}
+			pgbase = 0;
+			bytes -= req_len;
+			requested_bytes += req_len;
+			pos += req_len;
+			dreq->bytes_left -= req_len;
+		}
+		nfs_direct_release_pages(pagevec, npages);
+		kvfree(pagevec);
+		if (result < 0)
+			break;
+	}
+
+	nfs_pageio_complete(&desc);
+
+	/*
+	 * If no bytes were started, return the error, and let the
+	 * generic layer handle the completion.
+	 */
+	if (requested_bytes == 0) {
+		inode_dio_end(inode);
+		nfs_direct_req_release(dreq);
+		return result < 0 ? result : -EIO;
+	}
+
+	if (put_dreq(dreq))
+		nfs_direct_complete(dreq);
+	return requested_bytes;
+}
+
+/**
+ * nfs_file_direct_read - file direct read operation for NFS files
+ * @iocb: target I/O control block
+ * @iter: vector of user buffers into which to read data
+ * @swap: flag indicating this is swap IO, not O_DIRECT IO
+ *
+ * We use this function for direct reads instead of calling
+ * generic_file_aio_read() in order to avoid gfar's check to see if
+ * the request starts before the end of the file.  For that check
+ * to work, we must generate a GETATTR before each direct read, and
+ * even then there is a window between the GETATTR and the subsequent
+ * READ where the file size could change.  Our preference is simply
+ * to do all reads the application wants, and the server will take
+ * care of managing the end of file boundary.
+ *
+ * This function also eliminates unnecessarily updating the file's
+ * atime locally, as the NFS server sets the file's atime, and this
+ * client must read the updated atime from the server back into its
+ * cache.
+ */
+ssize_t nfs_file_direct_read(struct kiocb *iocb, struct iov_iter *iter,
+			     bool swap)
+{
+	struct file *file = iocb->ki_filp;
+	struct address_space *mapping = file->f_mapping;
+	struct inode *inode = mapping->host;
+	struct nfs_direct_req *dreq;
+	struct nfs_lock_context *l_ctx;
+	ssize_t result, requested;
+	size_t count = iov_iter_count(iter);
+	nfs_add_stats(mapping->host, NFSIOS_DIRECTREADBYTES, count);
+
+	dfprintk(FILE, "NFS: direct read(%pD2, %zd@%Ld)\n",
+		file, count, (long long) iocb->ki_pos);
+
+	result = 0;
+	if (!count)
+		goto out;
+
+	task_io_account_read(count);
+
+	result = -ENOMEM;
+	dreq = nfs_direct_req_alloc();
+	if (dreq == NULL)
+		goto out;
+
+	dreq->inode = inode;
+	dreq->bytes_left = dreq->max_count = count;
+	dreq->io_start = iocb->ki_pos;
+	dreq->ctx = get_nfs_open_context(nfs_file_open_context(iocb->ki_filp));
+	l_ctx = nfs_get_lock_context(dreq->ctx);
+	if (IS_ERR(l_ctx)) {
+		result = PTR_ERR(l_ctx);
+		nfs_direct_req_release(dreq);
+		goto out_release;
+	}
+	dreq->l_ctx = l_ctx;
+	if (!is_sync_kiocb(iocb))
+		dreq->iocb = iocb;
+
+	if (iter_is_iovec(iter))
+		dreq->flags = NFS_ODIRECT_SHOULD_DIRTY;
+
+	if (!swap)
+		nfs_start_io_direct(inode);
+
+	NFS_I(inode)->read_io += count;
+	requested = nfs_direct_read_schedule_iovec(dreq, iter, iocb->ki_pos);
+
+	if (!swap)
+		nfs_end_io_direct(inode);
+
+	if (requested > 0) {
+		result = nfs_direct_wait(dreq);
+		if (result > 0) {
+			requested -= result;
+			iocb->ki_pos += result;
+		}
+		iov_iter_revert(iter, requested);
+	} else {
+		result = requested;
+	}
+
+out_release:
+	nfs_direct_req_release(dreq);
+out:
+	return result;
+}
+
+static void nfs_direct_add_page_head(struct list_head *list,
+				     struct nfs_page *req)
+{
+	struct nfs_page *head = req->wb_head;
+
+	if (!list_empty(&head->wb_list) || !nfs_lock_request(head))
+		return;
+	if (!list_empty(&head->wb_list)) {
+		nfs_unlock_request(head);
+		return;
+	}
+	list_add(&head->wb_list, list);
+	kref_get(&head->wb_kref);
+	kref_get(&head->wb_kref);
+}
+
+static void nfs_direct_join_group(struct list_head *list,
+				  struct nfs_commit_info *cinfo,
+				  struct inode *inode)
+{
+	struct nfs_page *req, *subreq;
+
+	list_for_each_entry(req, list, wb_list) {
+		if (req->wb_head != req) {
+			nfs_direct_add_page_head(&req->wb_list, req);
+			continue;
+		}
+		subreq = req->wb_this_page;
+		if (subreq == req)
+			continue;
+		do {
+			/*
+			 * Remove subrequests from this list before freeing
+			 * them in the call to nfs_join_page_group().
+			 */
+			if (!list_empty(&subreq->wb_list)) {
+				nfs_list_remove_request(subreq);
+				nfs_release_request(subreq);
+			}
+		} while ((subreq = subreq->wb_this_page) != req);
+		nfs_join_page_group(req, cinfo, inode);
+	}
+}
+
+static void
+nfs_direct_write_scan_commit_list(struct inode *inode,
+				  struct list_head *list,
+				  struct nfs_commit_info *cinfo)
+{
+	mutex_lock(&NFS_I(cinfo->inode)->commit_mutex);
+	pnfs_recover_commit_reqs(list, cinfo);
+	nfs_scan_commit_list(&cinfo->mds->list, list, cinfo, 0);
+	mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);
+}
+
+static void nfs_direct_write_reschedule(struct nfs_direct_req *dreq)
+{
+	struct nfs_pageio_descriptor desc;
+	struct nfs_page *req, *tmp;
+	LIST_HEAD(reqs);
+	struct nfs_commit_info cinfo;
+	LIST_HEAD(failed);
+
+	nfs_init_cinfo_from_dreq(&cinfo, dreq);
+	nfs_direct_write_scan_commit_list(dreq->inode, &reqs, &cinfo);
+
+	nfs_direct_join_group(&reqs, &cinfo, dreq->inode);
+
+	dreq->count = 0;
+	dreq->max_count = 0;
+	list_for_each_entry(req, &reqs, wb_list)
+		dreq->max_count += req->wb_bytes;
+	nfs_clear_pnfs_ds_commit_verifiers(&dreq->ds_cinfo);
+	get_dreq(dreq);
+
+	nfs_pageio_init_write(&desc, dreq->inode, FLUSH_STABLE, false,
+			      &nfs_direct_write_completion_ops);
+	desc.pg_dreq = dreq;
+
+	list_for_each_entry_safe(req, tmp, &reqs, wb_list) {
+		/* Bump the transmission count */
+		req->wb_nio++;
+		if (!nfs_pageio_add_request(&desc, req)) {
+			nfs_list_move_request(req, &failed);
+			spin_lock(&cinfo.inode->i_lock);
+			dreq->flags = 0;
+			if (desc.pg_error < 0)
+				dreq->error = desc.pg_error;
+			else
+				dreq->error = -EIO;
+			spin_unlock(&cinfo.inode->i_lock);
+		}
+		nfs_release_request(req);
+	}
+	nfs_pageio_complete(&desc);
+
+	while (!list_empty(&failed)) {
+		req = nfs_list_entry(failed.next);
+		nfs_list_remove_request(req);
+		nfs_unlock_and_release_request(req);
+	}
+
+	if (put_dreq(dreq))
+		nfs_direct_write_complete(dreq);
+}
+
+static void nfs_direct_commit_complete(struct nfs_commit_data *data)
+{
+	const struct nfs_writeverf *verf = data->res.verf;
+	struct nfs_direct_req *dreq = data->dreq;
+	struct nfs_commit_info cinfo;
+	struct nfs_page *req;
+	int status = data->task.tk_status;
+
+	if (status < 0) {
+		/* Errors in commit are fatal */
+		dreq->error = status;
+		dreq->max_count = 0;
+		dreq->count = 0;
+		dreq->flags = NFS_ODIRECT_DONE;
+	} else if (dreq->flags == NFS_ODIRECT_DONE)
+		status = dreq->error;
+
+	nfs_init_cinfo_from_dreq(&cinfo, dreq);
+
+	while (!list_empty(&data->pages)) {
+		req = nfs_list_entry(data->pages.next);
+		nfs_list_remove_request(req);
+		if (status >= 0 && !nfs_write_match_verf(verf, req)) {
+			dreq->flags = NFS_ODIRECT_RESCHED_WRITES;
+			/*
+			 * Despite the reboot, the write was successful,
+			 * so reset wb_nio.
+			 */
+			req->wb_nio = 0;
+			nfs_mark_request_commit(req, NULL, &cinfo, 0);
+		} else /* Error or match */
+			nfs_release_request(req);
+		nfs_unlock_and_release_request(req);
+	}
+
+	if (nfs_commit_end(cinfo.mds))
+		nfs_direct_write_complete(dreq);
+}
+
+static void nfs_direct_resched_write(struct nfs_commit_info *cinfo,
+		struct nfs_page *req)
+{
+	struct nfs_direct_req *dreq = cinfo->dreq;
+
+	spin_lock(&dreq->lock);
+	if (dreq->flags != NFS_ODIRECT_DONE)
+		dreq->flags = NFS_ODIRECT_RESCHED_WRITES;
+	spin_unlock(&dreq->lock);
+	nfs_mark_request_commit(req, NULL, cinfo, 0);
+}
+
+static const struct nfs_commit_completion_ops nfs_direct_commit_completion_ops = {
+	.completion = nfs_direct_commit_complete,
+	.resched_write = nfs_direct_resched_write,
+};
+
+static void nfs_direct_commit_schedule(struct nfs_direct_req *dreq)
+{
+	int res;
+	struct nfs_commit_info cinfo;
+	LIST_HEAD(mds_list);
+
+	nfs_init_cinfo_from_dreq(&cinfo, dreq);
+	nfs_scan_commit(dreq->inode, &mds_list, &cinfo);
+	res = nfs_generic_commit_list(dreq->inode, &mds_list, 0, &cinfo);
+	if (res < 0) /* res == -ENOMEM */
+		nfs_direct_write_reschedule(dreq);
+}
+
+static void nfs_direct_write_clear_reqs(struct nfs_direct_req *dreq)
+{
+	struct nfs_commit_info cinfo;
+	struct nfs_page *req;
+	LIST_HEAD(reqs);
+
+	nfs_init_cinfo_from_dreq(&cinfo, dreq);
+	nfs_direct_write_scan_commit_list(dreq->inode, &reqs, &cinfo);
+
+	while (!list_empty(&reqs)) {
+		req = nfs_list_entry(reqs.next);
+		nfs_list_remove_request(req);
+		nfs_release_request(req);
+		nfs_unlock_and_release_request(req);
+	}
+}
+
+static void nfs_direct_write_schedule_work(struct work_struct *work)
+{
+	struct nfs_direct_req *dreq = container_of(work, struct nfs_direct_req, work);
+	int flags = dreq->flags;
+
+	dreq->flags = 0;
+	switch (flags) {
+		case NFS_ODIRECT_DO_COMMIT:
+			nfs_direct_commit_schedule(dreq);
+			break;
+		case NFS_ODIRECT_RESCHED_WRITES:
+			nfs_direct_write_reschedule(dreq);
+			break;
+		default:
+			nfs_direct_write_clear_reqs(dreq);
+			nfs_zap_mapping(dreq->inode, dreq->inode->i_mapping);
+			nfs_direct_complete(dreq);
+	}
+}
+
+static void nfs_direct_write_complete(struct nfs_direct_req *dreq)
+{
+	queue_work(nfsiod_workqueue, &dreq->work); /* Calls nfs_direct_write_schedule_work */
+}
+
+static void nfs_direct_write_completion(struct nfs_pgio_header *hdr)
+{
+	struct nfs_direct_req *dreq = hdr->dreq;
+	struct nfs_commit_info cinfo;
+	struct nfs_page *req = nfs_list_entry(hdr->pages.next);
+	int flags = NFS_ODIRECT_DONE;
+
+	nfs_init_cinfo_from_dreq(&cinfo, dreq);
+
+	spin_lock(&dreq->lock);
+	if (test_bit(NFS_IOHDR_REDO, &hdr->flags)) {
+		spin_unlock(&dreq->lock);
+		goto out_put;
+	}
+
+	nfs_direct_count_bytes(dreq, hdr);
+	if (hdr->good_bytes != 0 && nfs_write_need_commit(hdr)) {
+		if (!dreq->flags)
+			dreq->flags = NFS_ODIRECT_DO_COMMIT;
+		flags = dreq->flags;
+	}
+	spin_unlock(&dreq->lock);
+
+	while (!list_empty(&hdr->pages)) {
+
+		req = nfs_list_entry(hdr->pages.next);
+		nfs_list_remove_request(req);
+		if (flags == NFS_ODIRECT_DO_COMMIT) {
+			kref_get(&req->wb_kref);
+			memcpy(&req->wb_verf, &hdr->verf.verifier,
+			       sizeof(req->wb_verf));
+			nfs_mark_request_commit(req, hdr->lseg, &cinfo,
+				hdr->ds_commit_idx);
+		} else if (flags == NFS_ODIRECT_RESCHED_WRITES) {
+			kref_get(&req->wb_kref);
+			nfs_mark_request_commit(req, NULL, &cinfo, 0);
+		}
+		nfs_unlock_and_release_request(req);
+	}
+
+out_put:
+	if (put_dreq(dreq))
+		nfs_direct_write_complete(dreq);
+	hdr->release(hdr);
+}
+
+static void nfs_write_sync_pgio_error(struct list_head *head, int error)
+{
+	struct nfs_page *req;
+
+	while (!list_empty(head)) {
+		req = nfs_list_entry(head->next);
+		nfs_list_remove_request(req);
+		nfs_unlock_and_release_request(req);
+	}
+}
+
+static void nfs_direct_write_reschedule_io(struct nfs_pgio_header *hdr)
+{
+	struct nfs_direct_req *dreq = hdr->dreq;
+
+	spin_lock(&dreq->lock);
+	if (dreq->error == 0) {
+		dreq->flags = NFS_ODIRECT_RESCHED_WRITES;
+		/* fake unstable write to let common nfs resend pages */
+		hdr->verf.committed = NFS_UNSTABLE;
+		hdr->good_bytes = hdr->args.offset + hdr->args.count -
+			hdr->io_start;
+	}
+	spin_unlock(&dreq->lock);
+}
+
+static const struct nfs_pgio_completion_ops nfs_direct_write_completion_ops = {
+	.error_cleanup = nfs_write_sync_pgio_error,
+	.init_hdr = nfs_direct_pgio_init,
+	.completion = nfs_direct_write_completion,
+	.reschedule_io = nfs_direct_write_reschedule_io,
+};
+
+
+/*
+ * NB: Return the value of the first error return code.  Subsequent
+ *     errors after the first one are ignored.
+ */
+/*
+ * For each wsize'd chunk of the user's buffer, dispatch an NFS WRITE
+ * operation.  If nfs_writedata_alloc() or get_user_pages() fails,
+ * bail and stop sending more writes.  Write length accounting is
+ * handled automatically by nfs_direct_write_result().  Otherwise, if
+ * no requests have been sent, just return an error.
+ */
+static ssize_t nfs_direct_write_schedule_iovec(struct nfs_direct_req *dreq,
+					       struct iov_iter *iter,
+					       loff_t pos, int ioflags)
+{
+	struct nfs_pageio_descriptor desc;
+	struct inode *inode = dreq->inode;
+	ssize_t result = 0;
+	size_t requested_bytes = 0;
+	size_t wsize = max_t(size_t, NFS_SERVER(inode)->wsize, PAGE_SIZE);
+
+	nfs_pageio_init_write(&desc, inode, ioflags, false,
+			      &nfs_direct_write_completion_ops);
+	desc.pg_dreq = dreq;
+	get_dreq(dreq);
+	inode_dio_begin(inode);
+
+	NFS_I(inode)->write_io += iov_iter_count(iter);
+	while (iov_iter_count(iter)) {
+		struct page **pagevec;
+		size_t bytes;
+		size_t pgbase;
+		unsigned npages, i;
+
+		result = iov_iter_get_pages_alloc(iter, &pagevec, 
+						  wsize, &pgbase);
+		if (result < 0)
+			break;
+
+		bytes = result;
+		iov_iter_advance(iter, bytes);
+		npages = (result + pgbase + PAGE_SIZE - 1) / PAGE_SIZE;
+		for (i = 0; i < npages; i++) {
+			struct nfs_page *req;
+			unsigned int req_len = min_t(size_t, bytes, PAGE_SIZE - pgbase);
+
+			req = nfs_create_request(dreq->ctx, pagevec[i],
+						 pgbase, req_len);
+			if (IS_ERR(req)) {
+				result = PTR_ERR(req);
+				break;
+			}
+
+			if (desc.pg_error < 0) {
+				nfs_free_request(req);
+				result = desc.pg_error;
+				break;
+			}
+
+			nfs_lock_request(req);
+			req->wb_index = pos >> PAGE_SHIFT;
+			req->wb_offset = pos & ~PAGE_MASK;
+			if (!nfs_pageio_add_request(&desc, req)) {
+				result = desc.pg_error;
+				nfs_unlock_and_release_request(req);
+				break;
+			}
+			pgbase = 0;
+			bytes -= req_len;
+			requested_bytes += req_len;
+			pos += req_len;
+			dreq->bytes_left -= req_len;
+		}
+		nfs_direct_release_pages(pagevec, npages);
+		kvfree(pagevec);
+		if (result < 0)
+			break;
+	}
+	nfs_pageio_complete(&desc);
+
+	/*
+	 * If no bytes were started, return the error, and let the
+	 * generic layer handle the completion.
+	 */
+	if (requested_bytes == 0) {
+		inode_dio_end(inode);
+		nfs_direct_req_release(dreq);
+		return result < 0 ? result : -EIO;
+	}
+
+	if (put_dreq(dreq))
+		nfs_direct_write_complete(dreq);
+	return requested_bytes;
+}
+
+/**
+ * nfs_file_direct_write - file direct write operation for NFS files
+ * @iocb: target I/O control block
+ * @iter: vector of user buffers from which to write data
+ * @swap: flag indicating this is swap IO, not O_DIRECT IO
+ *
+ * We use this function for direct writes instead of calling
+ * generic_file_aio_write() in order to avoid taking the inode
+ * semaphore and updating the i_size.  The NFS server will set
+ * the new i_size and this client must read the updated size
+ * back into its cache.  We let the server do generic write
+ * parameter checking and report problems.
+ *
+ * We eliminate local atime updates, see direct read above.
+ *
+ * We avoid unnecessary page cache invalidations for normal cached
+ * readers of this file.
+ *
+ * Note that O_APPEND is not supported for NFS direct writes, as there
+ * is no atomic O_APPEND write facility in the NFS protocol.
+ */
+ssize_t nfs_file_direct_write(struct kiocb *iocb, struct iov_iter *iter,
+			      bool swap)
+{
+	ssize_t result, requested;
+	size_t count;
+	struct file *file = iocb->ki_filp;
+	struct address_space *mapping = file->f_mapping;
+	struct inode *inode = mapping->host;
+	struct nfs_direct_req *dreq;
+	struct nfs_lock_context *l_ctx;
+	loff_t pos, end;
+
+	dfprintk(FILE, "NFS: direct write(%pD2, %zd@%Ld)\n",
+		file, iov_iter_count(iter), (long long) iocb->ki_pos);
+
+	if (swap)
+		/* bypass generic checks */
+		result =  iov_iter_count(iter);
+	else
+		result = generic_write_checks(iocb, iter);
+	if (result <= 0)
+		return result;
+	count = result;
+	nfs_add_stats(mapping->host, NFSIOS_DIRECTWRITTENBYTES, count);
+
+	pos = iocb->ki_pos;
+	end = (pos + iov_iter_count(iter) - 1) >> PAGE_SHIFT;
+
+	task_io_account_write(count);
+
+	result = -ENOMEM;
+	dreq = nfs_direct_req_alloc();
+	if (!dreq)
+		goto out;
+
+	dreq->inode = inode;
+	dreq->bytes_left = dreq->max_count = count;
+	dreq->io_start = pos;
+	dreq->ctx = get_nfs_open_context(nfs_file_open_context(iocb->ki_filp));
+	l_ctx = nfs_get_lock_context(dreq->ctx);
+	if (IS_ERR(l_ctx)) {
+		result = PTR_ERR(l_ctx);
+		nfs_direct_req_release(dreq);
+		goto out_release;
+	}
+	dreq->l_ctx = l_ctx;
+	if (!is_sync_kiocb(iocb))
+		dreq->iocb = iocb;
+	pnfs_init_ds_commit_info_ops(&dreq->ds_cinfo, inode);
+
+	if (swap) {
+		requested = nfs_direct_write_schedule_iovec(dreq, iter, pos,
+							    FLUSH_STABLE);
+	} else {
+		nfs_start_io_direct(inode);
+
+		requested = nfs_direct_write_schedule_iovec(dreq, iter, pos,
+							    FLUSH_COND_STABLE);
+
+		if (mapping->nrpages) {
+			invalidate_inode_pages2_range(mapping,
+						      pos >> PAGE_SHIFT, end);
+		}
+
+		nfs_end_io_direct(inode);
+	}
+
+	if (requested > 0) {
+		result = nfs_direct_wait(dreq);
+		if (result > 0) {
+			requested -= result;
+			iocb->ki_pos = pos + result;
+			/* XXX: should check the generic_write_sync retval */
+			generic_write_sync(iocb, result);
+		}
+		iov_iter_revert(iter, requested);
+	} else {
+		result = requested;
+	}
+out_release:
+	nfs_direct_req_release(dreq);
+out:
+	return result;
+}
+
+/**
+ * nfs_init_directcache - create a slab cache for nfs_direct_req structures
+ *
+ */
+int __init nfs_init_directcache(void)
+{
+	nfs_direct_cachep = kmem_cache_create("nfs_direct_cache",
+						sizeof(struct nfs_direct_req),
+						0, (SLAB_RECLAIM_ACCOUNT|
+							SLAB_MEM_SPREAD),
+						NULL);
+	if (nfs_direct_cachep == NULL)
+		return -ENOMEM;
+
+	return 0;
+}
+
+/**
+ * nfs_destroy_directcache - destroy the slab cache for nfs_direct_req structures
+ *
+ */
+void nfs_destroy_directcache(void)
+{
+	kmem_cache_destroy(nfs_direct_cachep);
+}
diff --git a/fs/nfs/dns_resolve.c b/fs/nfs/dns_resolve.c
new file mode 100644
index 000000000..e87d500ad
--- /dev/null
+++ b/fs/nfs/dns_resolve.c
@@ -0,0 +1,481 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/nfs/dns_resolve.c
+ *
+ * Copyright (c) 2009 Trond Myklebust <Trond.Myklebust@netapp.com>
+ *
+ * Resolves DNS hostnames into valid ip addresses
+ */
+
+#ifdef CONFIG_NFS_USE_KERNEL_DNS
+
+#include <linux/module.h>
+#include <linux/sunrpc/clnt.h>
+#include <linux/sunrpc/addr.h>
+#include <linux/dns_resolver.h>
+#include "dns_resolve.h"
+
+ssize_t nfs_dns_resolve_name(struct net *net, char *name, size_t namelen,
+		struct sockaddr *sa, size_t salen)
+{
+	ssize_t ret;
+	char *ip_addr = NULL;
+	int ip_len;
+
+	ip_len = dns_query(net, NULL, name, namelen, NULL, &ip_addr, NULL,
+			   false);
+	if (ip_len > 0)
+		ret = rpc_pton(net, ip_addr, ip_len, sa, salen);
+	else
+		ret = -ESRCH;
+	kfree(ip_addr);
+	return ret;
+}
+
+#else
+
+#include <linux/module.h>
+#include <linux/hash.h>
+#include <linux/string.h>
+#include <linux/kmod.h>
+#include <linux/slab.h>
+#include <linux/socket.h>
+#include <linux/seq_file.h>
+#include <linux/inet.h>
+#include <linux/sunrpc/clnt.h>
+#include <linux/sunrpc/addr.h>
+#include <linux/sunrpc/cache.h>
+#include <linux/sunrpc/svcauth.h>
+#include <linux/sunrpc/rpc_pipe_fs.h>
+#include <linux/nfs_fs.h>
+
+#include "nfs4_fs.h"
+#include "dns_resolve.h"
+#include "cache_lib.h"
+#include "netns.h"
+
+#define NFS_DNS_HASHBITS 4
+#define NFS_DNS_HASHTBL_SIZE (1 << NFS_DNS_HASHBITS)
+
+struct nfs_dns_ent {
+	struct cache_head h;
+
+	char *hostname;
+	size_t namelen;
+
+	struct sockaddr_storage addr;
+	size_t addrlen;
+	struct rcu_head rcu_head;
+};
+
+
+static void nfs_dns_ent_update(struct cache_head *cnew,
+		struct cache_head *ckey)
+{
+	struct nfs_dns_ent *new;
+	struct nfs_dns_ent *key;
+
+	new = container_of(cnew, struct nfs_dns_ent, h);
+	key = container_of(ckey, struct nfs_dns_ent, h);
+
+	memcpy(&new->addr, &key->addr, key->addrlen);
+	new->addrlen = key->addrlen;
+}
+
+static void nfs_dns_ent_init(struct cache_head *cnew,
+		struct cache_head *ckey)
+{
+	struct nfs_dns_ent *new;
+	struct nfs_dns_ent *key;
+
+	new = container_of(cnew, struct nfs_dns_ent, h);
+	key = container_of(ckey, struct nfs_dns_ent, h);
+
+	kfree(new->hostname);
+	new->hostname = kmemdup_nul(key->hostname, key->namelen, GFP_KERNEL);
+	if (new->hostname) {
+		new->namelen = key->namelen;
+		nfs_dns_ent_update(cnew, ckey);
+	} else {
+		new->namelen = 0;
+		new->addrlen = 0;
+	}
+}
+
+static void nfs_dns_ent_free_rcu(struct rcu_head *head)
+{
+	struct nfs_dns_ent *item;
+
+	item = container_of(head, struct nfs_dns_ent, rcu_head);
+	kfree(item->hostname);
+	kfree(item);
+}
+
+static void nfs_dns_ent_put(struct kref *ref)
+{
+	struct nfs_dns_ent *item;
+
+	item = container_of(ref, struct nfs_dns_ent, h.ref);
+	call_rcu(&item->rcu_head, nfs_dns_ent_free_rcu);
+}
+
+static struct cache_head *nfs_dns_ent_alloc(void)
+{
+	struct nfs_dns_ent *item = kmalloc(sizeof(*item), GFP_KERNEL);
+
+	if (item != NULL) {
+		item->hostname = NULL;
+		item->namelen = 0;
+		item->addrlen = 0;
+		return &item->h;
+	}
+	return NULL;
+};
+
+static unsigned int nfs_dns_hash(const struct nfs_dns_ent *key)
+{
+	return hash_str(key->hostname, NFS_DNS_HASHBITS);
+}
+
+static void nfs_dns_request(struct cache_detail *cd,
+		struct cache_head *ch,
+		char **bpp, int *blen)
+{
+	struct nfs_dns_ent *key = container_of(ch, struct nfs_dns_ent, h);
+
+	qword_add(bpp, blen, key->hostname);
+	(*bpp)[-1] = '\n';
+}
+
+static int nfs_dns_upcall(struct cache_detail *cd,
+		struct cache_head *ch)
+{
+	struct nfs_dns_ent *key = container_of(ch, struct nfs_dns_ent, h);
+
+	if (test_and_set_bit(CACHE_PENDING, &ch->flags))
+		return 0;
+	if (!nfs_cache_upcall(cd, key->hostname))
+		return 0;
+	clear_bit(CACHE_PENDING, &ch->flags);
+	return sunrpc_cache_pipe_upcall_timeout(cd, ch);
+}
+
+static int nfs_dns_match(struct cache_head *ca,
+		struct cache_head *cb)
+{
+	struct nfs_dns_ent *a;
+	struct nfs_dns_ent *b;
+
+	a = container_of(ca, struct nfs_dns_ent, h);
+	b = container_of(cb, struct nfs_dns_ent, h);
+
+	if (a->namelen == 0 || a->namelen != b->namelen)
+		return 0;
+	return memcmp(a->hostname, b->hostname, a->namelen) == 0;
+}
+
+static int nfs_dns_show(struct seq_file *m, struct cache_detail *cd,
+		struct cache_head *h)
+{
+	struct nfs_dns_ent *item;
+	long ttl;
+
+	if (h == NULL) {
+		seq_puts(m, "# ip address      hostname        ttl\n");
+		return 0;
+	}
+	item = container_of(h, struct nfs_dns_ent, h);
+	ttl = item->h.expiry_time - seconds_since_boot();
+	if (ttl < 0)
+		ttl = 0;
+
+	if (!test_bit(CACHE_NEGATIVE, &h->flags)) {
+		char buf[INET6_ADDRSTRLEN+IPV6_SCOPE_ID_LEN+1];
+
+		rpc_ntop((struct sockaddr *)&item->addr, buf, sizeof(buf));
+		seq_printf(m, "%15s ", buf);
+	} else
+		seq_puts(m, "<none>          ");
+	seq_printf(m, "%15s %ld\n", item->hostname, ttl);
+	return 0;
+}
+
+static struct nfs_dns_ent *nfs_dns_lookup(struct cache_detail *cd,
+		struct nfs_dns_ent *key)
+{
+	struct cache_head *ch;
+
+	ch = sunrpc_cache_lookup_rcu(cd,
+			&key->h,
+			nfs_dns_hash(key));
+	if (!ch)
+		return NULL;
+	return container_of(ch, struct nfs_dns_ent, h);
+}
+
+static struct nfs_dns_ent *nfs_dns_update(struct cache_detail *cd,
+		struct nfs_dns_ent *new,
+		struct nfs_dns_ent *key)
+{
+	struct cache_head *ch;
+
+	ch = sunrpc_cache_update(cd,
+			&new->h, &key->h,
+			nfs_dns_hash(key));
+	if (!ch)
+		return NULL;
+	return container_of(ch, struct nfs_dns_ent, h);
+}
+
+static int nfs_dns_parse(struct cache_detail *cd, char *buf, int buflen)
+{
+	char buf1[NFS_DNS_HOSTNAME_MAXLEN+1];
+	struct nfs_dns_ent key, *item;
+	unsigned int ttl;
+	ssize_t len;
+	int ret = -EINVAL;
+
+	if (buf[buflen-1] != '\n')
+		goto out;
+	buf[buflen-1] = '\0';
+
+	len = qword_get(&buf, buf1, sizeof(buf1));
+	if (len <= 0)
+		goto out;
+	key.addrlen = rpc_pton(cd->net, buf1, len,
+			(struct sockaddr *)&key.addr,
+			sizeof(key.addr));
+
+	len = qword_get(&buf, buf1, sizeof(buf1));
+	if (len <= 0)
+		goto out;
+
+	key.hostname = buf1;
+	key.namelen = len;
+	memset(&key.h, 0, sizeof(key.h));
+
+	if (get_uint(&buf, &ttl) < 0)
+		goto out;
+	if (ttl == 0)
+		goto out;
+	key.h.expiry_time = ttl + seconds_since_boot();
+
+	ret = -ENOMEM;
+	item = nfs_dns_lookup(cd, &key);
+	if (item == NULL)
+		goto out;
+
+	if (key.addrlen == 0)
+		set_bit(CACHE_NEGATIVE, &key.h.flags);
+
+	item = nfs_dns_update(cd, &key, item);
+	if (item == NULL)
+		goto out;
+
+	ret = 0;
+	cache_put(&item->h, cd);
+out:
+	return ret;
+}
+
+static int do_cache_lookup(struct cache_detail *cd,
+		struct nfs_dns_ent *key,
+		struct nfs_dns_ent **item,
+		struct nfs_cache_defer_req *dreq)
+{
+	int ret = -ENOMEM;
+
+	*item = nfs_dns_lookup(cd, key);
+	if (*item) {
+		ret = cache_check(cd, &(*item)->h, &dreq->req);
+		if (ret)
+			*item = NULL;
+	}
+	return ret;
+}
+
+static int do_cache_lookup_nowait(struct cache_detail *cd,
+		struct nfs_dns_ent *key,
+		struct nfs_dns_ent **item)
+{
+	int ret = -ENOMEM;
+
+	*item = nfs_dns_lookup(cd, key);
+	if (!*item)
+		goto out_err;
+	ret = -ETIMEDOUT;
+	if (!test_bit(CACHE_VALID, &(*item)->h.flags)
+			|| (*item)->h.expiry_time < seconds_since_boot()
+			|| cd->flush_time > (*item)->h.last_refresh)
+		goto out_put;
+	ret = -ENOENT;
+	if (test_bit(CACHE_NEGATIVE, &(*item)->h.flags))
+		goto out_put;
+	return 0;
+out_put:
+	cache_put(&(*item)->h, cd);
+out_err:
+	*item = NULL;
+	return ret;
+}
+
+static int do_cache_lookup_wait(struct cache_detail *cd,
+		struct nfs_dns_ent *key,
+		struct nfs_dns_ent **item)
+{
+	struct nfs_cache_defer_req *dreq;
+	int ret = -ENOMEM;
+
+	dreq = nfs_cache_defer_req_alloc();
+	if (!dreq)
+		goto out;
+	ret = do_cache_lookup(cd, key, item, dreq);
+	if (ret == -EAGAIN) {
+		ret = nfs_cache_wait_for_upcall(dreq);
+		if (!ret)
+			ret = do_cache_lookup_nowait(cd, key, item);
+	}
+	nfs_cache_defer_req_put(dreq);
+out:
+	return ret;
+}
+
+ssize_t nfs_dns_resolve_name(struct net *net, char *name,
+		size_t namelen, struct sockaddr *sa, size_t salen)
+{
+	struct nfs_dns_ent key = {
+		.hostname = name,
+		.namelen = namelen,
+	};
+	struct nfs_dns_ent *item = NULL;
+	ssize_t ret;
+	struct nfs_net *nn = net_generic(net, nfs_net_id);
+
+	ret = do_cache_lookup_wait(nn->nfs_dns_resolve, &key, &item);
+	if (ret == 0) {
+		if (salen >= item->addrlen) {
+			memcpy(sa, &item->addr, item->addrlen);
+			ret = item->addrlen;
+		} else
+			ret = -EOVERFLOW;
+		cache_put(&item->h, nn->nfs_dns_resolve);
+	} else if (ret == -ENOENT)
+		ret = -ESRCH;
+	return ret;
+}
+
+static struct cache_detail nfs_dns_resolve_template = {
+	.owner		= THIS_MODULE,
+	.hash_size	= NFS_DNS_HASHTBL_SIZE,
+	.name		= "dns_resolve",
+	.cache_put	= nfs_dns_ent_put,
+	.cache_upcall	= nfs_dns_upcall,
+	.cache_request	= nfs_dns_request,
+	.cache_parse	= nfs_dns_parse,
+	.cache_show	= nfs_dns_show,
+	.match		= nfs_dns_match,
+	.init		= nfs_dns_ent_init,
+	.update		= nfs_dns_ent_update,
+	.alloc		= nfs_dns_ent_alloc,
+};
+
+
+int nfs_dns_resolver_cache_init(struct net *net)
+{
+	int err;
+	struct nfs_net *nn = net_generic(net, nfs_net_id);
+
+	nn->nfs_dns_resolve = cache_create_net(&nfs_dns_resolve_template, net);
+	if (IS_ERR(nn->nfs_dns_resolve))
+		return PTR_ERR(nn->nfs_dns_resolve);
+
+	err = nfs_cache_register_net(net, nn->nfs_dns_resolve);
+	if (err)
+		goto err_reg;
+	return 0;
+
+err_reg:
+	cache_destroy_net(nn->nfs_dns_resolve, net);
+	return err;
+}
+
+void nfs_dns_resolver_cache_destroy(struct net *net)
+{
+	struct nfs_net *nn = net_generic(net, nfs_net_id);
+
+	nfs_cache_unregister_net(net, nn->nfs_dns_resolve);
+	cache_destroy_net(nn->nfs_dns_resolve, net);
+}
+
+static int nfs4_dns_net_init(struct net *net)
+{
+	return nfs_dns_resolver_cache_init(net);
+}
+
+static void nfs4_dns_net_exit(struct net *net)
+{
+	nfs_dns_resolver_cache_destroy(net);
+}
+
+static struct pernet_operations nfs4_dns_resolver_ops = {
+	.init = nfs4_dns_net_init,
+	.exit = nfs4_dns_net_exit,
+};
+
+static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event,
+			   void *ptr)
+{
+	struct super_block *sb = ptr;
+	struct net *net = sb->s_fs_info;
+	struct nfs_net *nn = net_generic(net, nfs_net_id);
+	struct cache_detail *cd = nn->nfs_dns_resolve;
+	int ret = 0;
+
+	if (cd == NULL)
+		return 0;
+
+	if (!try_module_get(THIS_MODULE))
+		return 0;
+
+	switch (event) {
+	case RPC_PIPEFS_MOUNT:
+		ret = nfs_cache_register_sb(sb, cd);
+		break;
+	case RPC_PIPEFS_UMOUNT:
+		nfs_cache_unregister_sb(sb, cd);
+		break;
+	default:
+		ret = -ENOTSUPP;
+		break;
+	}
+	module_put(THIS_MODULE);
+	return ret;
+}
+
+static struct notifier_block nfs_dns_resolver_block = {
+	.notifier_call	= rpc_pipefs_event,
+};
+
+int nfs_dns_resolver_init(void)
+{
+	int err;
+
+	err = register_pernet_subsys(&nfs4_dns_resolver_ops);
+	if (err < 0)
+		goto out;
+	err = rpc_pipefs_notifier_register(&nfs_dns_resolver_block);
+	if (err < 0)
+		goto out1;
+	return 0;
+out1:
+	unregister_pernet_subsys(&nfs4_dns_resolver_ops);
+out:
+	return err;
+}
+
+void nfs_dns_resolver_destroy(void)
+{
+	rpc_pipefs_notifier_unregister(&nfs_dns_resolver_block);
+	unregister_pernet_subsys(&nfs4_dns_resolver_ops);
+}
+#endif
diff --git a/fs/nfs/dns_resolve.h b/fs/nfs/dns_resolve.h
new file mode 100644
index 000000000..576ff4b54
--- /dev/null
+++ b/fs/nfs/dns_resolve.h
@@ -0,0 +1,37 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Resolve DNS hostnames into valid ip addresses
+ */
+#ifndef __LINUX_FS_NFS_DNS_RESOLVE_H
+#define __LINUX_FS_NFS_DNS_RESOLVE_H
+
+#define NFS_DNS_HOSTNAME_MAXLEN	(128)
+
+
+#ifdef CONFIG_NFS_USE_KERNEL_DNS
+static inline int nfs_dns_resolver_init(void)
+{
+	return 0;
+}
+
+static inline void nfs_dns_resolver_destroy(void)
+{}
+
+static inline int nfs_dns_resolver_cache_init(struct net *net)
+{
+	return 0;
+}
+
+static inline void nfs_dns_resolver_cache_destroy(struct net *net)
+{}
+#else
+extern int nfs_dns_resolver_init(void);
+extern void nfs_dns_resolver_destroy(void);
+extern int nfs_dns_resolver_cache_init(struct net *net);
+extern void nfs_dns_resolver_cache_destroy(struct net *net);
+#endif
+
+extern ssize_t nfs_dns_resolve_name(struct net *net, char *name,
+		size_t namelen,	struct sockaddr *sa, size_t salen);
+
+#endif
diff --git a/fs/nfs/export.c b/fs/nfs/export.c
new file mode 100644
index 000000000..3430d6891
--- /dev/null
+++ b/fs/nfs/export.c
@@ -0,0 +1,174 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2015, Primary Data, Inc. All rights reserved.
+ *
+ * Tao Peng <bergwolf@primarydata.com>
+ */
+#include <linux/dcache.h>
+#include <linux/exportfs.h>
+#include <linux/nfs.h>
+#include <linux/nfs_fs.h>
+
+#include "internal.h"
+#include "nfstrace.h"
+
+#define NFSDBG_FACILITY		NFSDBG_VFS
+
+enum {
+	FILEID_HIGH_OFF = 0,	/* inode fileid high */
+	FILEID_LOW_OFF,		/* inode fileid low */
+	FILE_I_TYPE_OFF,	/* inode type */
+	EMBED_FH_OFF		/* embeded server fh */
+};
+
+
+static struct nfs_fh *nfs_exp_embedfh(__u32 *p)
+{
+	return (struct nfs_fh *)(p + EMBED_FH_OFF);
+}
+
+/*
+ * Let's break subtree checking for now... otherwise we'll have to embed parent fh
+ * but there might not be enough space.
+ */
+static int
+nfs_encode_fh(struct inode *inode, __u32 *p, int *max_len, struct inode *parent)
+{
+	struct nfs_fh *server_fh = NFS_FH(inode);
+	struct nfs_fh *clnt_fh = nfs_exp_embedfh(p);
+	size_t fh_size = offsetof(struct nfs_fh, data) + server_fh->size;
+	int len = EMBED_FH_OFF + XDR_QUADLEN(fh_size);
+
+	dprintk("%s: max fh len %d inode %p parent %p",
+		__func__, *max_len, inode, parent);
+
+	if (*max_len < len || IS_AUTOMOUNT(inode)) {
+		dprintk("%s: fh len %d too small, required %d\n",
+			__func__, *max_len, len);
+		*max_len = len;
+		return FILEID_INVALID;
+	}
+
+	p[FILEID_HIGH_OFF] = NFS_FILEID(inode) >> 32;
+	p[FILEID_LOW_OFF] = NFS_FILEID(inode);
+	p[FILE_I_TYPE_OFF] = inode->i_mode & S_IFMT;
+	p[len - 1] = 0; /* Padding */
+	nfs_copy_fh(clnt_fh, server_fh);
+	*max_len = len;
+	dprintk("%s: result fh fileid %llu mode %u size %d\n",
+		__func__, NFS_FILEID(inode), inode->i_mode, *max_len);
+	return *max_len;
+}
+
+static struct dentry *
+nfs_fh_to_dentry(struct super_block *sb, struct fid *fid,
+		 int fh_len, int fh_type)
+{
+	struct nfs4_label *label = NULL;
+	struct nfs_fattr *fattr = NULL;
+	struct nfs_fh *server_fh = nfs_exp_embedfh(fid->raw);
+	size_t fh_size = offsetof(struct nfs_fh, data) + server_fh->size;
+	const struct nfs_rpc_ops *rpc_ops;
+	struct dentry *dentry;
+	struct inode *inode;
+	int len = EMBED_FH_OFF + XDR_QUADLEN(fh_size);
+	u32 *p = fid->raw;
+	int ret;
+
+	/* NULL translates to ESTALE */
+	if (fh_len < len || fh_type != len)
+		return NULL;
+
+	fattr = nfs_alloc_fattr();
+	if (fattr == NULL) {
+		dentry = ERR_PTR(-ENOMEM);
+		goto out;
+	}
+
+	fattr->fileid = ((u64)p[FILEID_HIGH_OFF] << 32) + p[FILEID_LOW_OFF];
+	fattr->mode = p[FILE_I_TYPE_OFF];
+	fattr->valid |= NFS_ATTR_FATTR_FILEID | NFS_ATTR_FATTR_TYPE;
+
+	dprintk("%s: fileid %llu mode %d\n", __func__, fattr->fileid, fattr->mode);
+
+	inode = nfs_ilookup(sb, fattr, server_fh);
+	if (inode)
+		goto out_found;
+
+	label = nfs4_label_alloc(NFS_SB(sb), GFP_KERNEL);
+	if (IS_ERR(label)) {
+		dentry = ERR_CAST(label);
+		goto out_free_fattr;
+	}
+
+	rpc_ops = NFS_SB(sb)->nfs_client->rpc_ops;
+	ret = rpc_ops->getattr(NFS_SB(sb), server_fh, fattr, label, NULL);
+	if (ret) {
+		dprintk("%s: getattr failed %d\n", __func__, ret);
+		trace_nfs_fh_to_dentry(sb, server_fh, fattr->fileid, ret);
+		dentry = ERR_PTR(ret);
+		goto out_free_label;
+	}
+
+	inode = nfs_fhget(sb, server_fh, fattr, label);
+
+out_found:
+	dentry = d_obtain_alias(inode);
+
+out_free_label:
+	nfs4_label_free(label);
+out_free_fattr:
+	nfs_free_fattr(fattr);
+out:
+	return dentry;
+}
+
+static struct dentry *
+nfs_get_parent(struct dentry *dentry)
+{
+	int ret;
+	struct inode *inode = d_inode(dentry), *pinode;
+	struct super_block *sb = inode->i_sb;
+	struct nfs_server *server = NFS_SB(sb);
+	struct nfs_fattr *fattr = NULL;
+	struct nfs4_label *label = NULL;
+	struct dentry *parent;
+	struct nfs_rpc_ops const *ops = server->nfs_client->rpc_ops;
+	struct nfs_fh fh;
+
+	if (!ops->lookupp)
+		return ERR_PTR(-EACCES);
+
+	fattr = nfs_alloc_fattr();
+	if (fattr == NULL) {
+		parent = ERR_PTR(-ENOMEM);
+		goto out;
+	}
+
+	label = nfs4_label_alloc(server, GFP_KERNEL);
+	if (IS_ERR(label)) {
+		parent = ERR_CAST(label);
+		goto out_free_fattr;
+	}
+
+	ret = ops->lookupp(inode, &fh, fattr, label);
+	if (ret) {
+		parent = ERR_PTR(ret);
+		goto out_free_label;
+	}
+
+	pinode = nfs_fhget(sb, &fh, fattr, label);
+	parent = d_obtain_alias(pinode);
+out_free_label:
+	nfs4_label_free(label);
+out_free_fattr:
+	nfs_free_fattr(fattr);
+out:
+	return parent;
+}
+
+const struct export_operations nfs_export_ops = {
+	.encode_fh = nfs_encode_fh,
+	.fh_to_dentry = nfs_fh_to_dentry,
+	.get_parent = nfs_get_parent,
+};
diff --git a/fs/nfs/file.c b/fs/nfs/file.c
new file mode 100644
index 000000000..7be1a7f7f
--- /dev/null
+++ b/fs/nfs/file.c
@@ -0,0 +1,874 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  linux/fs/nfs/file.c
+ *
+ *  Copyright (C) 1992  Rick Sladkey
+ *
+ *  Changes Copyright (C) 1994 by Florian La Roche
+ *   - Do not copy data too often around in the kernel.
+ *   - In nfs_file_read the return value of kmalloc wasn't checked.
+ *   - Put in a better version of read look-ahead buffering. Original idea
+ *     and implementation by Wai S Kok elekokws@ee.nus.sg.
+ *
+ *  Expire cache on write to a file by Wai S Kok (Oct 1994).
+ *
+ *  Total rewrite of read side for new NFS buffer cache.. Linus.
+ *
+ *  nfs regular file handling functions
+ */
+
+#include <linux/module.h>
+#include <linux/time.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/fcntl.h>
+#include <linux/stat.h>
+#include <linux/nfs_fs.h>
+#include <linux/nfs_mount.h>
+#include <linux/mm.h>
+#include <linux/pagemap.h>
+#include <linux/gfp.h>
+#include <linux/swap.h>
+
+#include <linux/uaccess.h>
+
+#include "delegation.h"
+#include "internal.h"
+#include "iostat.h"
+#include "fscache.h"
+#include "pnfs.h"
+
+#include "nfstrace.h"
+
+#define NFSDBG_FACILITY		NFSDBG_FILE
+
+static const struct vm_operations_struct nfs_file_vm_ops;
+
+/* Hack for future NFS swap support */
+#ifndef IS_SWAPFILE
+# define IS_SWAPFILE(inode)	(0)
+#endif
+
+int nfs_check_flags(int flags)
+{
+	if ((flags & (O_APPEND | O_DIRECT)) == (O_APPEND | O_DIRECT))
+		return -EINVAL;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nfs_check_flags);
+
+/*
+ * Open file
+ */
+static int
+nfs_file_open(struct inode *inode, struct file *filp)
+{
+	int res;
+
+	dprintk("NFS: open file(%pD2)\n", filp);
+
+	nfs_inc_stats(inode, NFSIOS_VFSOPEN);
+	res = nfs_check_flags(filp->f_flags);
+	if (res)
+		return res;
+
+	res = nfs_open(inode, filp);
+	return res;
+}
+
+int
+nfs_file_release(struct inode *inode, struct file *filp)
+{
+	dprintk("NFS: release(%pD2)\n", filp);
+
+	nfs_inc_stats(inode, NFSIOS_VFSRELEASE);
+	nfs_file_clear_open_context(filp);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nfs_file_release);
+
+/**
+ * nfs_revalidate_size - Revalidate the file size
+ * @inode: pointer to inode struct
+ * @filp: pointer to struct file
+ *
+ * Revalidates the file length. This is basically a wrapper around
+ * nfs_revalidate_inode() that takes into account the fact that we may
+ * have cached writes (in which case we don't care about the server's
+ * idea of what the file length is), or O_DIRECT (in which case we
+ * shouldn't trust the cache).
+ */
+static int nfs_revalidate_file_size(struct inode *inode, struct file *filp)
+{
+	struct nfs_server *server = NFS_SERVER(inode);
+
+	if (filp->f_flags & O_DIRECT)
+		goto force_reval;
+	if (nfs_check_cache_invalid(inode, NFS_INO_REVAL_PAGECACHE))
+		goto force_reval;
+	return 0;
+force_reval:
+	return __nfs_revalidate_inode(server, inode);
+}
+
+loff_t nfs_file_llseek(struct file *filp, loff_t offset, int whence)
+{
+	dprintk("NFS: llseek file(%pD2, %lld, %d)\n",
+			filp, offset, whence);
+
+	/*
+	 * whence == SEEK_END || SEEK_DATA || SEEK_HOLE => we must revalidate
+	 * the cached file length
+	 */
+	if (whence != SEEK_SET && whence != SEEK_CUR) {
+		struct inode *inode = filp->f_mapping->host;
+
+		int retval = nfs_revalidate_file_size(inode, filp);
+		if (retval < 0)
+			return (loff_t)retval;
+	}
+
+	return generic_file_llseek(filp, offset, whence);
+}
+EXPORT_SYMBOL_GPL(nfs_file_llseek);
+
+/*
+ * Flush all dirty pages, and check for write errors.
+ */
+static int
+nfs_file_flush(struct file *file, fl_owner_t id)
+{
+	struct inode	*inode = file_inode(file);
+	errseq_t since;
+
+	dprintk("NFS: flush(%pD2)\n", file);
+
+	nfs_inc_stats(inode, NFSIOS_VFSFLUSH);
+	if ((file->f_mode & FMODE_WRITE) == 0)
+		return 0;
+
+	/* Flush writes to the server and return any errors */
+	since = filemap_sample_wb_err(file->f_mapping);
+	nfs_wb_all(inode);
+	return filemap_check_wb_err(file->f_mapping, since);
+}
+
+ssize_t
+nfs_file_read(struct kiocb *iocb, struct iov_iter *to)
+{
+	struct inode *inode = file_inode(iocb->ki_filp);
+	ssize_t result;
+
+	if (iocb->ki_flags & IOCB_DIRECT)
+		return nfs_file_direct_read(iocb, to, false);
+
+	dprintk("NFS: read(%pD2, %zu@%lu)\n",
+		iocb->ki_filp,
+		iov_iter_count(to), (unsigned long) iocb->ki_pos);
+
+	nfs_start_io_read(inode);
+	result = nfs_revalidate_mapping(inode, iocb->ki_filp->f_mapping);
+	if (!result) {
+		result = generic_file_read_iter(iocb, to);
+		if (result > 0)
+			nfs_add_stats(inode, NFSIOS_NORMALREADBYTES, result);
+	}
+	nfs_end_io_read(inode);
+	return result;
+}
+EXPORT_SYMBOL_GPL(nfs_file_read);
+
+int
+nfs_file_mmap(struct file * file, struct vm_area_struct * vma)
+{
+	struct inode *inode = file_inode(file);
+	int	status;
+
+	dprintk("NFS: mmap(%pD2)\n", file);
+
+	/* Note: generic_file_mmap() returns ENOSYS on nommu systems
+	 *       so we call that before revalidating the mapping
+	 */
+	status = generic_file_mmap(file, vma);
+	if (!status) {
+		vma->vm_ops = &nfs_file_vm_ops;
+		status = nfs_revalidate_mapping(inode, file->f_mapping);
+	}
+	return status;
+}
+EXPORT_SYMBOL_GPL(nfs_file_mmap);
+
+/*
+ * Flush any dirty pages for this process, and check for write errors.
+ * The return status from this call provides a reliable indication of
+ * whether any write errors occurred for this process.
+ */
+static int
+nfs_file_fsync_commit(struct file *file, int datasync)
+{
+	struct inode *inode = file_inode(file);
+	int ret, ret2;
+
+	dprintk("NFS: fsync file(%pD2) datasync %d\n", file, datasync);
+
+	nfs_inc_stats(inode, NFSIOS_VFSFSYNC);
+	ret = nfs_commit_inode(inode, FLUSH_SYNC);
+	ret2 = file_check_and_advance_wb_err(file);
+	if (ret2 < 0)
+		return ret2;
+	return ret;
+}
+
+int
+nfs_file_fsync(struct file *file, loff_t start, loff_t end, int datasync)
+{
+	struct nfs_open_context *ctx = nfs_file_open_context(file);
+	struct inode *inode = file_inode(file);
+	int ret;
+
+	trace_nfs_fsync_enter(inode);
+
+	for (;;) {
+		ret = file_write_and_wait_range(file, start, end);
+		if (ret != 0)
+			break;
+		ret = nfs_file_fsync_commit(file, datasync);
+		if (ret != 0)
+			break;
+		ret = pnfs_sync_inode(inode, !!datasync);
+		if (ret != 0)
+			break;
+		if (!test_and_clear_bit(NFS_CONTEXT_RESEND_WRITES, &ctx->flags))
+			break;
+		/*
+		 * If nfs_file_fsync_commit detected a server reboot, then
+		 * resend all dirty pages that might have been covered by
+		 * the NFS_CONTEXT_RESEND_WRITES flag
+		 */
+		start = 0;
+		end = LLONG_MAX;
+	}
+
+	trace_nfs_fsync_exit(inode, ret);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(nfs_file_fsync);
+
+/*
+ * Decide whether a read/modify/write cycle may be more efficient
+ * then a modify/write/read cycle when writing to a page in the
+ * page cache.
+ *
+ * Some pNFS layout drivers can only read/write at a certain block
+ * granularity like all block devices and therefore we must perform
+ * read/modify/write whenever a page hasn't read yet and the data
+ * to be written there is not aligned to a block boundary and/or
+ * smaller than the block size.
+ *
+ * The modify/write/read cycle may occur if a page is read before
+ * being completely filled by the writer.  In this situation, the
+ * page must be completely written to stable storage on the server
+ * before it can be refilled by reading in the page from the server.
+ * This can lead to expensive, small, FILE_SYNC mode writes being
+ * done.
+ *
+ * It may be more efficient to read the page first if the file is
+ * open for reading in addition to writing, the page is not marked
+ * as Uptodate, it is not dirty or waiting to be committed,
+ * indicating that it was previously allocated and then modified,
+ * that there were valid bytes of data in that range of the file,
+ * and that the new data won't completely replace the old data in
+ * that range of the file.
+ */
+static bool nfs_full_page_write(struct page *page, loff_t pos, unsigned int len)
+{
+	unsigned int pglen = nfs_page_length(page);
+	unsigned int offset = pos & (PAGE_SIZE - 1);
+	unsigned int end = offset + len;
+
+	return !pglen || (end >= pglen && !offset);
+}
+
+static bool nfs_want_read_modify_write(struct file *file, struct page *page,
+			loff_t pos, unsigned int len)
+{
+	/*
+	 * Up-to-date pages, those with ongoing or full-page write
+	 * don't need read/modify/write
+	 */
+	if (PageUptodate(page) || PagePrivate(page) ||
+	    nfs_full_page_write(page, pos, len))
+		return false;
+
+	if (pnfs_ld_read_whole_page(file->f_mapping->host))
+		return true;
+	/* Open for reading too? */
+	if (file->f_mode & FMODE_READ)
+		return true;
+	return false;
+}
+
+/*
+ * This does the "real" work of the write. We must allocate and lock the
+ * page to be sent back to the generic routine, which then copies the
+ * data from user space.
+ *
+ * If the writer ends up delaying the write, the writer needs to
+ * increment the page use counts until he is done with the page.
+ */
+static int nfs_write_begin(struct file *file, struct address_space *mapping,
+			loff_t pos, unsigned len, unsigned flags,
+			struct page **pagep, void **fsdata)
+{
+	int ret;
+	pgoff_t index = pos >> PAGE_SHIFT;
+	struct page *page;
+	int once_thru = 0;
+
+	dfprintk(PAGECACHE, "NFS: write_begin(%pD2(%lu), %u@%lld)\n",
+		file, mapping->host->i_ino, len, (long long) pos);
+
+start:
+	page = grab_cache_page_write_begin(mapping, index, flags);
+	if (!page)
+		return -ENOMEM;
+	*pagep = page;
+
+	ret = nfs_flush_incompatible(file, page);
+	if (ret) {
+		unlock_page(page);
+		put_page(page);
+	} else if (!once_thru &&
+		   nfs_want_read_modify_write(file, page, pos, len)) {
+		once_thru = 1;
+		ret = nfs_readpage(file, page);
+		put_page(page);
+		if (!ret)
+			goto start;
+	}
+	return ret;
+}
+
+static int nfs_write_end(struct file *file, struct address_space *mapping,
+			loff_t pos, unsigned len, unsigned copied,
+			struct page *page, void *fsdata)
+{
+	unsigned offset = pos & (PAGE_SIZE - 1);
+	struct nfs_open_context *ctx = nfs_file_open_context(file);
+	int status;
+
+	dfprintk(PAGECACHE, "NFS: write_end(%pD2(%lu), %u@%lld)\n",
+		file, mapping->host->i_ino, len, (long long) pos);
+
+	/*
+	 * Zero any uninitialised parts of the page, and then mark the page
+	 * as up to date if it turns out that we're extending the file.
+	 */
+	if (!PageUptodate(page)) {
+		unsigned pglen = nfs_page_length(page);
+		unsigned end = offset + copied;
+
+		if (pglen == 0) {
+			zero_user_segments(page, 0, offset,
+					end, PAGE_SIZE);
+			SetPageUptodate(page);
+		} else if (end >= pglen) {
+			zero_user_segment(page, end, PAGE_SIZE);
+			if (offset == 0)
+				SetPageUptodate(page);
+		} else
+			zero_user_segment(page, pglen, PAGE_SIZE);
+	}
+
+	status = nfs_updatepage(file, page, offset, copied);
+
+	unlock_page(page);
+	put_page(page);
+
+	if (status < 0)
+		return status;
+	NFS_I(mapping->host)->write_io += copied;
+
+	if (nfs_ctx_key_to_expire(ctx, mapping->host))
+		nfs_wb_all(mapping->host);
+
+	return copied;
+}
+
+/*
+ * Partially or wholly invalidate a page
+ * - Release the private state associated with a page if undergoing complete
+ *   page invalidation
+ * - Called if either PG_private or PG_fscache is set on the page
+ * - Caller holds page lock
+ */
+static void nfs_invalidate_page(struct page *page, unsigned int offset,
+				unsigned int length)
+{
+	dfprintk(PAGECACHE, "NFS: invalidate_page(%p, %u, %u)\n",
+		 page, offset, length);
+
+	if (offset != 0 || length < PAGE_SIZE)
+		return;
+	/* Cancel any unstarted writes on this page */
+	nfs_wb_page_cancel(page_file_mapping(page)->host, page);
+
+	nfs_fscache_invalidate_page(page, page->mapping->host);
+}
+
+/*
+ * Attempt to release the private state associated with a page
+ * - Called if either PG_private or PG_fscache is set on the page
+ * - Caller holds page lock
+ * - Return true (may release page) or false (may not)
+ */
+static int nfs_release_page(struct page *page, gfp_t gfp)
+{
+	dfprintk(PAGECACHE, "NFS: release_page(%p)\n", page);
+
+	/* If PagePrivate() is set, then the page is not freeable */
+	if (PagePrivate(page))
+		return 0;
+	return nfs_fscache_release_page(page, gfp);
+}
+
+static void nfs_check_dirty_writeback(struct page *page,
+				bool *dirty, bool *writeback)
+{
+	struct nfs_inode *nfsi;
+	struct address_space *mapping = page_file_mapping(page);
+
+	if (!mapping || PageSwapCache(page))
+		return;
+
+	/*
+	 * Check if an unstable page is currently being committed and
+	 * if so, have the VM treat it as if the page is under writeback
+	 * so it will not block due to pages that will shortly be freeable.
+	 */
+	nfsi = NFS_I(mapping->host);
+	if (atomic_read(&nfsi->commit_info.rpcs_out)) {
+		*writeback = true;
+		return;
+	}
+
+	/*
+	 * If PagePrivate() is set, then the page is not freeable and as the
+	 * inode is not being committed, it's not going to be cleaned in the
+	 * near future so treat it as dirty
+	 */
+	if (PagePrivate(page))
+		*dirty = true;
+}
+
+/*
+ * Attempt to clear the private state associated with a page when an error
+ * occurs that requires the cached contents of an inode to be written back or
+ * destroyed
+ * - Called if either PG_private or fscache is set on the page
+ * - Caller holds page lock
+ * - Return 0 if successful, -error otherwise
+ */
+static int nfs_launder_page(struct page *page)
+{
+	struct inode *inode = page_file_mapping(page)->host;
+	struct nfs_inode *nfsi = NFS_I(inode);
+
+	dfprintk(PAGECACHE, "NFS: launder_page(%ld, %llu)\n",
+		inode->i_ino, (long long)page_offset(page));
+
+	nfs_fscache_wait_on_page_write(nfsi, page);
+	return nfs_wb_page(inode, page);
+}
+
+static int nfs_swap_activate(struct swap_info_struct *sis, struct file *file,
+						sector_t *span)
+{
+	unsigned long blocks;
+	long long isize;
+	struct inode *inode = file_inode(file);
+	struct rpc_clnt *clnt = NFS_CLIENT(inode);
+	struct nfs_client *cl = NFS_SERVER(inode)->nfs_client;
+
+	spin_lock(&inode->i_lock);
+	blocks = inode->i_blocks;
+	isize = inode->i_size;
+	spin_unlock(&inode->i_lock);
+	if (blocks*512 < isize) {
+		pr_warn("swap activate: swapfile has holes\n");
+		return -EINVAL;
+	}
+
+	*span = sis->pages;
+
+
+	if (cl->rpc_ops->enable_swap)
+		cl->rpc_ops->enable_swap(inode);
+
+	return rpc_clnt_swap_activate(clnt);
+}
+
+static void nfs_swap_deactivate(struct file *file)
+{
+	struct inode *inode = file_inode(file);
+	struct rpc_clnt *clnt = NFS_CLIENT(inode);
+	struct nfs_client *cl = NFS_SERVER(inode)->nfs_client;
+
+	rpc_clnt_swap_deactivate(clnt);
+	if (cl->rpc_ops->disable_swap)
+		cl->rpc_ops->disable_swap(file_inode(file));
+}
+
+const struct address_space_operations nfs_file_aops = {
+	.readpage = nfs_readpage,
+	.readpages = nfs_readpages,
+	.set_page_dirty = __set_page_dirty_nobuffers,
+	.writepage = nfs_writepage,
+	.writepages = nfs_writepages,
+	.write_begin = nfs_write_begin,
+	.write_end = nfs_write_end,
+	.invalidatepage = nfs_invalidate_page,
+	.releasepage = nfs_release_page,
+	.direct_IO = nfs_direct_IO,
+#ifdef CONFIG_MIGRATION
+	.migratepage = nfs_migrate_page,
+#endif
+	.launder_page = nfs_launder_page,
+	.is_dirty_writeback = nfs_check_dirty_writeback,
+	.error_remove_page = generic_error_remove_page,
+	.swap_activate = nfs_swap_activate,
+	.swap_deactivate = nfs_swap_deactivate,
+};
+
+/*
+ * Notification that a PTE pointing to an NFS page is about to be made
+ * writable, implying that someone is about to modify the page through a
+ * shared-writable mapping
+ */
+static vm_fault_t nfs_vm_page_mkwrite(struct vm_fault *vmf)
+{
+	struct page *page = vmf->page;
+	struct file *filp = vmf->vma->vm_file;
+	struct inode *inode = file_inode(filp);
+	unsigned pagelen;
+	vm_fault_t ret = VM_FAULT_NOPAGE;
+	struct address_space *mapping;
+
+	dfprintk(PAGECACHE, "NFS: vm_page_mkwrite(%pD2(%lu), offset %lld)\n",
+		filp, filp->f_mapping->host->i_ino,
+		(long long)page_offset(page));
+
+	sb_start_pagefault(inode->i_sb);
+
+	/* make sure the cache has finished storing the page */
+	nfs_fscache_wait_on_page_write(NFS_I(inode), page);
+
+	wait_on_bit_action(&NFS_I(inode)->flags, NFS_INO_INVALIDATING,
+			nfs_wait_bit_killable, TASK_KILLABLE);
+
+	lock_page(page);
+	mapping = page_file_mapping(page);
+	if (mapping != inode->i_mapping)
+		goto out_unlock;
+
+	wait_on_page_writeback(page);
+
+	pagelen = nfs_page_length(page);
+	if (pagelen == 0)
+		goto out_unlock;
+
+	ret = VM_FAULT_LOCKED;
+	if (nfs_flush_incompatible(filp, page) == 0 &&
+	    nfs_updatepage(filp, page, 0, pagelen) == 0)
+		goto out;
+
+	ret = VM_FAULT_SIGBUS;
+out_unlock:
+	unlock_page(page);
+out:
+	sb_end_pagefault(inode->i_sb);
+	return ret;
+}
+
+static const struct vm_operations_struct nfs_file_vm_ops = {
+	.fault = filemap_fault,
+	.map_pages = filemap_map_pages,
+	.page_mkwrite = nfs_vm_page_mkwrite,
+};
+
+static int nfs_need_check_write(struct file *filp, struct inode *inode,
+				int error)
+{
+	struct nfs_open_context *ctx;
+
+	ctx = nfs_file_open_context(filp);
+	if (nfs_error_is_fatal_on_server(error) ||
+	    nfs_ctx_key_to_expire(ctx, inode))
+		return 1;
+	return 0;
+}
+
+ssize_t nfs_file_write(struct kiocb *iocb, struct iov_iter *from)
+{
+	struct file *file = iocb->ki_filp;
+	struct inode *inode = file_inode(file);
+	unsigned long written = 0;
+	ssize_t result;
+	errseq_t since;
+	int error;
+
+	result = nfs_key_timeout_notify(file, inode);
+	if (result)
+		return result;
+
+	if (iocb->ki_flags & IOCB_DIRECT)
+		return nfs_file_direct_write(iocb, from, false);
+
+	dprintk("NFS: write(%pD2, %zu@%Ld)\n",
+		file, iov_iter_count(from), (long long) iocb->ki_pos);
+
+	if (IS_SWAPFILE(inode))
+		goto out_swapfile;
+	/*
+	 * O_APPEND implies that we must revalidate the file length.
+	 */
+	if (iocb->ki_flags & IOCB_APPEND) {
+		result = nfs_revalidate_file_size(inode, file);
+		if (result)
+			goto out;
+	}
+	if (iocb->ki_pos > i_size_read(inode))
+		nfs_revalidate_mapping(inode, file->f_mapping);
+
+	since = filemap_sample_wb_err(file->f_mapping);
+	nfs_start_io_write(inode);
+	result = generic_write_checks(iocb, from);
+	if (result > 0) {
+		current->backing_dev_info = inode_to_bdi(inode);
+		result = generic_perform_write(file, from, iocb->ki_pos);
+		current->backing_dev_info = NULL;
+	}
+	nfs_end_io_write(inode);
+	if (result <= 0)
+		goto out;
+
+	written = result;
+	iocb->ki_pos += written;
+	result = generic_write_sync(iocb, written);
+	if (result < 0)
+		goto out;
+
+	/* Return error values */
+	error = filemap_check_wb_err(file->f_mapping, since);
+	if (nfs_need_check_write(file, inode, error)) {
+		int err = nfs_wb_all(inode);
+		if (err < 0)
+			result = err;
+	}
+	nfs_add_stats(inode, NFSIOS_NORMALWRITTENBYTES, written);
+out:
+	return result;
+
+out_swapfile:
+	printk(KERN_INFO "NFS: attempt to write to active swap file!\n");
+	return -ETXTBSY;
+}
+EXPORT_SYMBOL_GPL(nfs_file_write);
+
+static int
+do_getlk(struct file *filp, int cmd, struct file_lock *fl, int is_local)
+{
+	struct inode *inode = filp->f_mapping->host;
+	int status = 0;
+	unsigned int saved_type = fl->fl_type;
+
+	/* Try local locking first */
+	posix_test_lock(filp, fl);
+	if (fl->fl_type != F_UNLCK) {
+		/* found a conflict */
+		goto out;
+	}
+	fl->fl_type = saved_type;
+
+	if (NFS_PROTO(inode)->have_delegation(inode, FMODE_READ))
+		goto out_noconflict;
+
+	if (is_local)
+		goto out_noconflict;
+
+	status = NFS_PROTO(inode)->lock(filp, cmd, fl);
+out:
+	return status;
+out_noconflict:
+	fl->fl_type = F_UNLCK;
+	goto out;
+}
+
+static int
+do_unlk(struct file *filp, int cmd, struct file_lock *fl, int is_local)
+{
+	struct inode *inode = filp->f_mapping->host;
+	struct nfs_lock_context *l_ctx;
+	int status;
+
+	/*
+	 * Flush all pending writes before doing anything
+	 * with locks..
+	 */
+	nfs_wb_all(inode);
+
+	l_ctx = nfs_get_lock_context(nfs_file_open_context(filp));
+	if (!IS_ERR(l_ctx)) {
+		status = nfs_iocounter_wait(l_ctx);
+		nfs_put_lock_context(l_ctx);
+		/*  NOTE: special case
+		 * 	If we're signalled while cleaning up locks on process exit, we
+		 * 	still need to complete the unlock.
+		 */
+		if (status < 0 && !(fl->fl_flags & FL_CLOSE))
+			return status;
+	}
+
+	/*
+	 * Use local locking if mounted with "-onolock" or with appropriate
+	 * "-olocal_lock="
+	 */
+	if (!is_local)
+		status = NFS_PROTO(inode)->lock(filp, cmd, fl);
+	else
+		status = locks_lock_file_wait(filp, fl);
+	return status;
+}
+
+static int
+do_setlk(struct file *filp, int cmd, struct file_lock *fl, int is_local)
+{
+	struct inode *inode = filp->f_mapping->host;
+	int status;
+
+	/*
+	 * Flush all pending writes before doing anything
+	 * with locks..
+	 */
+	status = nfs_sync_mapping(filp->f_mapping);
+	if (status != 0)
+		goto out;
+
+	/*
+	 * Use local locking if mounted with "-onolock" or with appropriate
+	 * "-olocal_lock="
+	 */
+	if (!is_local)
+		status = NFS_PROTO(inode)->lock(filp, cmd, fl);
+	else
+		status = locks_lock_file_wait(filp, fl);
+	if (status < 0)
+		goto out;
+
+	/*
+	 * Invalidate cache to prevent missing any changes.  If
+	 * the file is mapped, clear the page cache as well so
+	 * those mappings will be loaded.
+	 *
+	 * This makes locking act as a cache coherency point.
+	 */
+	nfs_sync_mapping(filp->f_mapping);
+	if (!NFS_PROTO(inode)->have_delegation(inode, FMODE_READ)) {
+		nfs_zap_caches(inode);
+		if (mapping_mapped(filp->f_mapping))
+			nfs_revalidate_mapping(inode, filp->f_mapping);
+	}
+out:
+	return status;
+}
+
+/*
+ * Lock a (portion of) a file
+ */
+int nfs_lock(struct file *filp, int cmd, struct file_lock *fl)
+{
+	struct inode *inode = filp->f_mapping->host;
+	int ret = -ENOLCK;
+	int is_local = 0;
+
+	dprintk("NFS: lock(%pD2, t=%x, fl=%x, r=%lld:%lld)\n",
+			filp, fl->fl_type, fl->fl_flags,
+			(long long)fl->fl_start, (long long)fl->fl_end);
+
+	nfs_inc_stats(inode, NFSIOS_VFSLOCK);
+
+	/* No mandatory locks over NFS */
+	if (__mandatory_lock(inode) && fl->fl_type != F_UNLCK)
+		goto out_err;
+
+	if (NFS_SERVER(inode)->flags & NFS_MOUNT_LOCAL_FCNTL)
+		is_local = 1;
+
+	if (NFS_PROTO(inode)->lock_check_bounds != NULL) {
+		ret = NFS_PROTO(inode)->lock_check_bounds(fl);
+		if (ret < 0)
+			goto out_err;
+	}
+
+	if (IS_GETLK(cmd))
+		ret = do_getlk(filp, cmd, fl, is_local);
+	else if (fl->fl_type == F_UNLCK)
+		ret = do_unlk(filp, cmd, fl, is_local);
+	else
+		ret = do_setlk(filp, cmd, fl, is_local);
+out_err:
+	return ret;
+}
+EXPORT_SYMBOL_GPL(nfs_lock);
+
+/*
+ * Lock a (portion of) a file
+ */
+int nfs_flock(struct file *filp, int cmd, struct file_lock *fl)
+{
+	struct inode *inode = filp->f_mapping->host;
+	int is_local = 0;
+
+	dprintk("NFS: flock(%pD2, t=%x, fl=%x)\n",
+			filp, fl->fl_type, fl->fl_flags);
+
+	if (!(fl->fl_flags & FL_FLOCK))
+		return -ENOLCK;
+
+	/*
+	 * The NFSv4 protocol doesn't support LOCK_MAND, which is not part of
+	 * any standard. In principle we might be able to support LOCK_MAND
+	 * on NFSv2/3 since NLMv3/4 support DOS share modes, but for now the
+	 * NFS code is not set up for it.
+	 */
+	if (fl->fl_type & LOCK_MAND)
+		return -EINVAL;
+
+	if (NFS_SERVER(inode)->flags & NFS_MOUNT_LOCAL_FLOCK)
+		is_local = 1;
+
+	/* We're simulating flock() locks using posix locks on the server */
+	if (fl->fl_type == F_UNLCK)
+		return do_unlk(filp, cmd, fl, is_local);
+	return do_setlk(filp, cmd, fl, is_local);
+}
+EXPORT_SYMBOL_GPL(nfs_flock);
+
+const struct file_operations nfs_file_operations = {
+	.llseek		= nfs_file_llseek,
+	.read_iter	= nfs_file_read,
+	.write_iter	= nfs_file_write,
+	.mmap		= nfs_file_mmap,
+	.open		= nfs_file_open,
+	.flush		= nfs_file_flush,
+	.release	= nfs_file_release,
+	.fsync		= nfs_file_fsync,
+	.lock		= nfs_lock,
+	.flock		= nfs_flock,
+	.splice_read	= generic_file_splice_read,
+	.splice_write	= iter_file_splice_write,
+	.check_flags	= nfs_check_flags,
+	.setlease	= simple_nosetlease,
+};
+EXPORT_SYMBOL_GPL(nfs_file_operations);
diff --git a/fs/nfs/filelayout/Makefile b/fs/nfs/filelayout/Makefile
new file mode 100644
index 000000000..de056312d
--- /dev/null
+++ b/fs/nfs/filelayout/Makefile
@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Makefile for the pNFS Files Layout Driver kernel module
+#
+obj-$(CONFIG_PNFS_FILE_LAYOUT) += nfs_layout_nfsv41_files.o
+nfs_layout_nfsv41_files-y := filelayout.o filelayoutdev.o
diff --git a/fs/nfs/filelayout/filelayout.c b/fs/nfs/filelayout/filelayout.c
new file mode 100644
index 000000000..deecfb50d
--- /dev/null
+++ b/fs/nfs/filelayout/filelayout.c
@@ -0,0 +1,1155 @@
+/*
+ *  Module for the pnfs nfs4 file layout driver.
+ *  Defines all I/O and Policy interface operations, plus code
+ *  to register itself with the pNFS client.
+ *
+ *  Copyright (c) 2002
+ *  The Regents of the University of Michigan
+ *  All Rights Reserved
+ *
+ *  Dean Hildebrand <dhildebz@umich.edu>
+ *
+ *  Permission is granted to use, copy, create derivative works, and
+ *  redistribute this software and such derivative works for any purpose,
+ *  so long as the name of the University of Michigan is not used in
+ *  any advertising or publicity pertaining to the use or distribution
+ *  of this software without specific, written prior authorization. If
+ *  the above copyright notice or any other identification of the
+ *  University of Michigan is included in any copy of any portion of
+ *  this software, then the disclaimer below must also be included.
+ *
+ *  This software is provided as is, without representation or warranty
+ *  of any kind either express or implied, including without limitation
+ *  the implied warranties of merchantability, fitness for a particular
+ *  purpose, or noninfringement.  The Regents of the University of
+ *  Michigan shall not be liable for any damages, including special,
+ *  indirect, incidental, or consequential damages, with respect to any
+ *  claim arising out of or in connection with the use of the software,
+ *  even if it has been or is hereafter advised of the possibility of
+ *  such damages.
+ */
+
+#include <linux/nfs_fs.h>
+#include <linux/nfs_page.h>
+#include <linux/module.h>
+#include <linux/backing-dev.h>
+
+#include <linux/sunrpc/metrics.h>
+
+#include "../nfs4session.h"
+#include "../internal.h"
+#include "../delegation.h"
+#include "filelayout.h"
+#include "../nfs4trace.h"
+
+#define NFSDBG_FACILITY         NFSDBG_PNFS_LD
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Dean Hildebrand <dhildebz@umich.edu>");
+MODULE_DESCRIPTION("The NFSv4 file layout driver");
+
+#define FILELAYOUT_POLL_RETRY_MAX     (15*HZ)
+static const struct pnfs_commit_ops filelayout_commit_ops;
+
+static loff_t
+filelayout_get_dense_offset(struct nfs4_filelayout_segment *flseg,
+			    loff_t offset)
+{
+	u32 stripe_width = flseg->stripe_unit * flseg->dsaddr->stripe_count;
+	u64 stripe_no;
+	u32 rem;
+
+	offset -= flseg->pattern_offset;
+	stripe_no = div_u64(offset, stripe_width);
+	div_u64_rem(offset, flseg->stripe_unit, &rem);
+
+	return stripe_no * flseg->stripe_unit + rem;
+}
+
+/* This function is used by the layout driver to calculate the
+ * offset of the file on the dserver based on whether the
+ * layout type is STRIPE_DENSE or STRIPE_SPARSE
+ */
+static loff_t
+filelayout_get_dserver_offset(struct pnfs_layout_segment *lseg, loff_t offset)
+{
+	struct nfs4_filelayout_segment *flseg = FILELAYOUT_LSEG(lseg);
+
+	switch (flseg->stripe_type) {
+	case STRIPE_SPARSE:
+		return offset;
+
+	case STRIPE_DENSE:
+		return filelayout_get_dense_offset(flseg, offset);
+	}
+
+	BUG();
+}
+
+static void filelayout_reset_write(struct nfs_pgio_header *hdr)
+{
+	struct rpc_task *task = &hdr->task;
+
+	if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
+		dprintk("%s Reset task %5u for i/o through MDS "
+			"(req %s/%llu, %u bytes @ offset %llu)\n", __func__,
+			hdr->task.tk_pid,
+			hdr->inode->i_sb->s_id,
+			(unsigned long long)NFS_FILEID(hdr->inode),
+			hdr->args.count,
+			(unsigned long long)hdr->args.offset);
+
+		task->tk_status = pnfs_write_done_resend_to_mds(hdr);
+	}
+}
+
+static void filelayout_reset_read(struct nfs_pgio_header *hdr)
+{
+	struct rpc_task *task = &hdr->task;
+
+	if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
+		dprintk("%s Reset task %5u for i/o through MDS "
+			"(req %s/%llu, %u bytes @ offset %llu)\n", __func__,
+			hdr->task.tk_pid,
+			hdr->inode->i_sb->s_id,
+			(unsigned long long)NFS_FILEID(hdr->inode),
+			hdr->args.count,
+			(unsigned long long)hdr->args.offset);
+
+		task->tk_status = pnfs_read_done_resend_to_mds(hdr);
+	}
+}
+
+static int filelayout_async_handle_error(struct rpc_task *task,
+					 struct nfs4_state *state,
+					 struct nfs_client *clp,
+					 struct pnfs_layout_segment *lseg)
+{
+	struct pnfs_layout_hdr *lo = lseg->pls_layout;
+	struct inode *inode = lo->plh_inode;
+	struct nfs4_deviceid_node *devid = FILELAYOUT_DEVID_NODE(lseg);
+	struct nfs4_slot_table *tbl = &clp->cl_session->fc_slot_table;
+
+	if (task->tk_status >= 0)
+		return 0;
+
+	switch (task->tk_status) {
+	/* DS session errors */
+	case -NFS4ERR_BADSESSION:
+	case -NFS4ERR_BADSLOT:
+	case -NFS4ERR_BAD_HIGH_SLOT:
+	case -NFS4ERR_DEADSESSION:
+	case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
+	case -NFS4ERR_SEQ_FALSE_RETRY:
+	case -NFS4ERR_SEQ_MISORDERED:
+		dprintk("%s ERROR %d, Reset session. Exchangeid "
+			"flags 0x%x\n", __func__, task->tk_status,
+			clp->cl_exchange_flags);
+		nfs4_schedule_session_recovery(clp->cl_session, task->tk_status);
+		break;
+	case -NFS4ERR_DELAY:
+	case -NFS4ERR_GRACE:
+		rpc_delay(task, FILELAYOUT_POLL_RETRY_MAX);
+		break;
+	case -NFS4ERR_RETRY_UNCACHED_REP:
+		break;
+	/* Invalidate Layout errors */
+	case -NFS4ERR_ACCESS:
+	case -NFS4ERR_PNFS_NO_LAYOUT:
+	case -ESTALE:           /* mapped NFS4ERR_STALE */
+	case -EBADHANDLE:       /* mapped NFS4ERR_BADHANDLE */
+	case -EISDIR:           /* mapped NFS4ERR_ISDIR */
+	case -NFS4ERR_FHEXPIRED:
+	case -NFS4ERR_WRONG_TYPE:
+		dprintk("%s Invalid layout error %d\n", __func__,
+			task->tk_status);
+		/*
+		 * Destroy layout so new i/o will get a new layout.
+		 * Layout will not be destroyed until all current lseg
+		 * references are put. Mark layout as invalid to resend failed
+		 * i/o and all i/o waiting on the slot table to the MDS until
+		 * layout is destroyed and a new valid layout is obtained.
+		 */
+		pnfs_destroy_layout(NFS_I(inode));
+		rpc_wake_up(&tbl->slot_tbl_waitq);
+		goto reset;
+	/* RPC connection errors */
+	case -ECONNREFUSED:
+	case -EHOSTDOWN:
+	case -EHOSTUNREACH:
+	case -ENETUNREACH:
+	case -EIO:
+	case -ETIMEDOUT:
+	case -EPIPE:
+		dprintk("%s DS connection error %d\n", __func__,
+			task->tk_status);
+		nfs4_mark_deviceid_unavailable(devid);
+		pnfs_error_mark_layout_for_return(inode, lseg);
+		pnfs_set_lo_fail(lseg);
+		rpc_wake_up(&tbl->slot_tbl_waitq);
+		fallthrough;
+	default:
+reset:
+		dprintk("%s Retry through MDS. Error %d\n", __func__,
+			task->tk_status);
+		return -NFS4ERR_RESET_TO_MDS;
+	}
+	task->tk_status = 0;
+	return -EAGAIN;
+}
+
+/* NFS_PROTO call done callback routines */
+
+static int filelayout_read_done_cb(struct rpc_task *task,
+				struct nfs_pgio_header *hdr)
+{
+	int err;
+
+	trace_nfs4_pnfs_read(hdr, task->tk_status);
+	err = filelayout_async_handle_error(task, hdr->args.context->state,
+					    hdr->ds_clp, hdr->lseg);
+
+	switch (err) {
+	case -NFS4ERR_RESET_TO_MDS:
+		filelayout_reset_read(hdr);
+		return task->tk_status;
+	case -EAGAIN:
+		rpc_restart_call_prepare(task);
+		return -EAGAIN;
+	}
+
+	return 0;
+}
+
+/*
+ * We reference the rpc_cred of the first WRITE that triggers the need for
+ * a LAYOUTCOMMIT, and use it to send the layoutcommit compound.
+ * rfc5661 is not clear about which credential should be used.
+ */
+static void
+filelayout_set_layoutcommit(struct nfs_pgio_header *hdr)
+{
+	loff_t end_offs = 0;
+
+	if (FILELAYOUT_LSEG(hdr->lseg)->commit_through_mds ||
+	    hdr->res.verf->committed == NFS_FILE_SYNC)
+		return;
+	if (hdr->res.verf->committed == NFS_DATA_SYNC)
+		end_offs = hdr->mds_offset + (loff_t)hdr->res.count;
+
+	/* Note: if the write is unstable, don't set end_offs until commit */
+	pnfs_set_layoutcommit(hdr->inode, hdr->lseg, end_offs);
+	dprintk("%s inode %lu pls_end_pos %lu\n", __func__, hdr->inode->i_ino,
+		(unsigned long) NFS_I(hdr->inode)->layout->plh_lwb);
+}
+
+bool
+filelayout_test_devid_unavailable(struct nfs4_deviceid_node *node)
+{
+	return filelayout_test_devid_invalid(node) ||
+		nfs4_test_deviceid_unavailable(node);
+}
+
+static bool
+filelayout_reset_to_mds(struct pnfs_layout_segment *lseg)
+{
+	struct nfs4_deviceid_node *node = FILELAYOUT_DEVID_NODE(lseg);
+
+	return filelayout_test_devid_unavailable(node);
+}
+
+/*
+ * Call ops for the async read/write cases
+ * In the case of dense layouts, the offset needs to be reset to its
+ * original value.
+ */
+static void filelayout_read_prepare(struct rpc_task *task, void *data)
+{
+	struct nfs_pgio_header *hdr = data;
+
+	if (unlikely(test_bit(NFS_CONTEXT_BAD, &hdr->args.context->flags))) {
+		rpc_exit(task, -EIO);
+		return;
+	}
+	if (filelayout_reset_to_mds(hdr->lseg)) {
+		dprintk("%s task %u reset io to MDS\n", __func__, task->tk_pid);
+		filelayout_reset_read(hdr);
+		rpc_exit(task, 0);
+		return;
+	}
+	hdr->pgio_done_cb = filelayout_read_done_cb;
+
+	if (nfs4_setup_sequence(hdr->ds_clp,
+			&hdr->args.seq_args,
+			&hdr->res.seq_res,
+			task))
+		return;
+	if (nfs4_set_rw_stateid(&hdr->args.stateid, hdr->args.context,
+			hdr->args.lock_context, FMODE_READ) == -EIO)
+		rpc_exit(task, -EIO); /* lost lock, terminate I/O */
+}
+
+static void filelayout_read_call_done(struct rpc_task *task, void *data)
+{
+	struct nfs_pgio_header *hdr = data;
+
+	dprintk("--> %s task->tk_status %d\n", __func__, task->tk_status);
+
+	if (test_bit(NFS_IOHDR_REDO, &hdr->flags) &&
+	    task->tk_status == 0) {
+		nfs41_sequence_done(task, &hdr->res.seq_res);
+		return;
+	}
+
+	/* Note this may cause RPC to be resent */
+	hdr->mds_ops->rpc_call_done(task, data);
+}
+
+static void filelayout_read_count_stats(struct rpc_task *task, void *data)
+{
+	struct nfs_pgio_header *hdr = data;
+
+	rpc_count_iostats(task, NFS_SERVER(hdr->inode)->client->cl_metrics);
+}
+
+static int filelayout_write_done_cb(struct rpc_task *task,
+				struct nfs_pgio_header *hdr)
+{
+	int err;
+
+	trace_nfs4_pnfs_write(hdr, task->tk_status);
+	err = filelayout_async_handle_error(task, hdr->args.context->state,
+					    hdr->ds_clp, hdr->lseg);
+
+	switch (err) {
+	case -NFS4ERR_RESET_TO_MDS:
+		filelayout_reset_write(hdr);
+		return task->tk_status;
+	case -EAGAIN:
+		rpc_restart_call_prepare(task);
+		return -EAGAIN;
+	}
+
+	filelayout_set_layoutcommit(hdr);
+
+	/* zero out the fattr */
+	hdr->fattr.valid = 0;
+	if (task->tk_status >= 0)
+		nfs_writeback_update_inode(hdr);
+
+	return 0;
+}
+
+static int filelayout_commit_done_cb(struct rpc_task *task,
+				     struct nfs_commit_data *data)
+{
+	int err;
+
+	trace_nfs4_pnfs_commit_ds(data, task->tk_status);
+	err = filelayout_async_handle_error(task, NULL, data->ds_clp,
+					    data->lseg);
+
+	switch (err) {
+	case -NFS4ERR_RESET_TO_MDS:
+		pnfs_generic_prepare_to_resend_writes(data);
+		return -EAGAIN;
+	case -EAGAIN:
+		rpc_restart_call_prepare(task);
+		return -EAGAIN;
+	}
+
+	pnfs_set_layoutcommit(data->inode, data->lseg, data->lwb);
+
+	return 0;
+}
+
+static void filelayout_write_prepare(struct rpc_task *task, void *data)
+{
+	struct nfs_pgio_header *hdr = data;
+
+	if (unlikely(test_bit(NFS_CONTEXT_BAD, &hdr->args.context->flags))) {
+		rpc_exit(task, -EIO);
+		return;
+	}
+	if (filelayout_reset_to_mds(hdr->lseg)) {
+		dprintk("%s task %u reset io to MDS\n", __func__, task->tk_pid);
+		filelayout_reset_write(hdr);
+		rpc_exit(task, 0);
+		return;
+	}
+	if (nfs4_setup_sequence(hdr->ds_clp,
+			&hdr->args.seq_args,
+			&hdr->res.seq_res,
+			task))
+		return;
+	if (nfs4_set_rw_stateid(&hdr->args.stateid, hdr->args.context,
+			hdr->args.lock_context, FMODE_WRITE) == -EIO)
+		rpc_exit(task, -EIO); /* lost lock, terminate I/O */
+}
+
+static void filelayout_write_call_done(struct rpc_task *task, void *data)
+{
+	struct nfs_pgio_header *hdr = data;
+
+	if (test_bit(NFS_IOHDR_REDO, &hdr->flags) &&
+	    task->tk_status == 0) {
+		nfs41_sequence_done(task, &hdr->res.seq_res);
+		return;
+	}
+
+	/* Note this may cause RPC to be resent */
+	hdr->mds_ops->rpc_call_done(task, data);
+}
+
+static void filelayout_write_count_stats(struct rpc_task *task, void *data)
+{
+	struct nfs_pgio_header *hdr = data;
+
+	rpc_count_iostats(task, NFS_SERVER(hdr->inode)->client->cl_metrics);
+}
+
+static void filelayout_commit_prepare(struct rpc_task *task, void *data)
+{
+	struct nfs_commit_data *wdata = data;
+
+	nfs4_setup_sequence(wdata->ds_clp,
+			&wdata->args.seq_args,
+			&wdata->res.seq_res,
+			task);
+}
+
+static void filelayout_commit_count_stats(struct rpc_task *task, void *data)
+{
+	struct nfs_commit_data *cdata = data;
+
+	rpc_count_iostats(task, NFS_SERVER(cdata->inode)->client->cl_metrics);
+}
+
+static const struct rpc_call_ops filelayout_read_call_ops = {
+	.rpc_call_prepare = filelayout_read_prepare,
+	.rpc_call_done = filelayout_read_call_done,
+	.rpc_count_stats = filelayout_read_count_stats,
+	.rpc_release = pnfs_generic_rw_release,
+};
+
+static const struct rpc_call_ops filelayout_write_call_ops = {
+	.rpc_call_prepare = filelayout_write_prepare,
+	.rpc_call_done = filelayout_write_call_done,
+	.rpc_count_stats = filelayout_write_count_stats,
+	.rpc_release = pnfs_generic_rw_release,
+};
+
+static const struct rpc_call_ops filelayout_commit_call_ops = {
+	.rpc_call_prepare = filelayout_commit_prepare,
+	.rpc_call_done = pnfs_generic_write_commit_done,
+	.rpc_count_stats = filelayout_commit_count_stats,
+	.rpc_release = pnfs_generic_commit_release,
+};
+
+static enum pnfs_try_status
+filelayout_read_pagelist(struct nfs_pgio_header *hdr)
+{
+	struct pnfs_layout_segment *lseg = hdr->lseg;
+	struct nfs4_pnfs_ds *ds;
+	struct rpc_clnt *ds_clnt;
+	loff_t offset = hdr->args.offset;
+	u32 j, idx;
+	struct nfs_fh *fh;
+
+	dprintk("--> %s ino %lu pgbase %u req %zu@%llu\n",
+		__func__, hdr->inode->i_ino,
+		hdr->args.pgbase, (size_t)hdr->args.count, offset);
+
+	/* Retrieve the correct rpc_client for the byte range */
+	j = nfs4_fl_calc_j_index(lseg, offset);
+	idx = nfs4_fl_calc_ds_index(lseg, j);
+	ds = nfs4_fl_prepare_ds(lseg, idx);
+	if (!ds)
+		return PNFS_NOT_ATTEMPTED;
+
+	ds_clnt = nfs4_find_or_create_ds_client(ds->ds_clp, hdr->inode);
+	if (IS_ERR(ds_clnt))
+		return PNFS_NOT_ATTEMPTED;
+
+	dprintk("%s USE DS: %s cl_count %d\n", __func__,
+		ds->ds_remotestr, refcount_read(&ds->ds_clp->cl_count));
+
+	/* No multipath support. Use first DS */
+	refcount_inc(&ds->ds_clp->cl_count);
+	hdr->ds_clp = ds->ds_clp;
+	hdr->ds_commit_idx = idx;
+	fh = nfs4_fl_select_ds_fh(lseg, j);
+	if (fh)
+		hdr->args.fh = fh;
+
+	hdr->args.offset = filelayout_get_dserver_offset(lseg, offset);
+	hdr->mds_offset = offset;
+
+	/* Perform an asynchronous read to ds */
+	nfs_initiate_pgio(ds_clnt, hdr, hdr->cred,
+			  NFS_PROTO(hdr->inode), &filelayout_read_call_ops,
+			  0, RPC_TASK_SOFTCONN);
+	return PNFS_ATTEMPTED;
+}
+
+/* Perform async writes. */
+static enum pnfs_try_status
+filelayout_write_pagelist(struct nfs_pgio_header *hdr, int sync)
+{
+	struct pnfs_layout_segment *lseg = hdr->lseg;
+	struct nfs4_pnfs_ds *ds;
+	struct rpc_clnt *ds_clnt;
+	loff_t offset = hdr->args.offset;
+	u32 j, idx;
+	struct nfs_fh *fh;
+
+	/* Retrieve the correct rpc_client for the byte range */
+	j = nfs4_fl_calc_j_index(lseg, offset);
+	idx = nfs4_fl_calc_ds_index(lseg, j);
+	ds = nfs4_fl_prepare_ds(lseg, idx);
+	if (!ds)
+		return PNFS_NOT_ATTEMPTED;
+
+	ds_clnt = nfs4_find_or_create_ds_client(ds->ds_clp, hdr->inode);
+	if (IS_ERR(ds_clnt))
+		return PNFS_NOT_ATTEMPTED;
+
+	dprintk("%s ino %lu sync %d req %zu@%llu DS: %s cl_count %d\n",
+		__func__, hdr->inode->i_ino, sync, (size_t) hdr->args.count,
+		offset, ds->ds_remotestr, refcount_read(&ds->ds_clp->cl_count));
+
+	hdr->pgio_done_cb = filelayout_write_done_cb;
+	refcount_inc(&ds->ds_clp->cl_count);
+	hdr->ds_clp = ds->ds_clp;
+	hdr->ds_commit_idx = idx;
+	fh = nfs4_fl_select_ds_fh(lseg, j);
+	if (fh)
+		hdr->args.fh = fh;
+	hdr->args.offset = filelayout_get_dserver_offset(lseg, offset);
+
+	/* Perform an asynchronous write */
+	nfs_initiate_pgio(ds_clnt, hdr, hdr->cred,
+			  NFS_PROTO(hdr->inode), &filelayout_write_call_ops,
+			  sync, RPC_TASK_SOFTCONN);
+	return PNFS_ATTEMPTED;
+}
+
+static int
+filelayout_check_deviceid(struct pnfs_layout_hdr *lo,
+			  struct nfs4_filelayout_segment *fl,
+			  gfp_t gfp_flags)
+{
+	struct nfs4_deviceid_node *d;
+	struct nfs4_file_layout_dsaddr *dsaddr;
+	int status = -EINVAL;
+
+	/* Is the deviceid already set? If so, we're good. */
+	if (fl->dsaddr != NULL)
+		return 0;
+
+	/* find and reference the deviceid */
+	d = nfs4_find_get_deviceid(NFS_SERVER(lo->plh_inode), &fl->deviceid,
+			lo->plh_lc_cred, gfp_flags);
+	if (d == NULL)
+		goto out;
+
+	dsaddr = container_of(d, struct nfs4_file_layout_dsaddr, id_node);
+	/* Found deviceid is unavailable */
+	if (filelayout_test_devid_unavailable(&dsaddr->id_node))
+		goto out_put;
+
+	if (fl->first_stripe_index >= dsaddr->stripe_count) {
+		dprintk("%s Bad first_stripe_index %u\n",
+				__func__, fl->first_stripe_index);
+		goto out_put;
+	}
+
+	if ((fl->stripe_type == STRIPE_SPARSE &&
+	    fl->num_fh > 1 && fl->num_fh != dsaddr->ds_num) ||
+	    (fl->stripe_type == STRIPE_DENSE &&
+	    fl->num_fh != dsaddr->stripe_count)) {
+		dprintk("%s num_fh %u not valid for given packing\n",
+			__func__, fl->num_fh);
+		goto out_put;
+	}
+	status = 0;
+
+	/*
+	 * Atomic compare and xchange to ensure we don't scribble
+	 * over a non-NULL pointer.
+	 */
+	if (cmpxchg(&fl->dsaddr, NULL, dsaddr) != NULL)
+		goto out_put;
+out:
+	return status;
+out_put:
+	nfs4_fl_put_deviceid(dsaddr);
+	goto out;
+}
+
+/*
+ * filelayout_check_layout()
+ *
+ * Make sure layout segment parameters are sane WRT the device.
+ * At this point no generic layer initialization of the lseg has occurred,
+ * and nothing has been added to the layout_hdr cache.
+ *
+ */
+static int
+filelayout_check_layout(struct pnfs_layout_hdr *lo,
+			struct nfs4_filelayout_segment *fl,
+			struct nfs4_layoutget_res *lgr,
+			gfp_t gfp_flags)
+{
+	int status = -EINVAL;
+
+	dprintk("--> %s\n", __func__);
+
+	/* FIXME: remove this check when layout segment support is added */
+	if (lgr->range.offset != 0 ||
+	    lgr->range.length != NFS4_MAX_UINT64) {
+		dprintk("%s Only whole file layouts supported. Use MDS i/o\n",
+			__func__);
+		goto out;
+	}
+
+	if (fl->pattern_offset > lgr->range.offset) {
+		dprintk("%s pattern_offset %lld too large\n",
+				__func__, fl->pattern_offset);
+		goto out;
+	}
+
+	if (!fl->stripe_unit) {
+		dprintk("%s Invalid stripe unit (%u)\n",
+			__func__, fl->stripe_unit);
+		goto out;
+	}
+
+	status = 0;
+out:
+	dprintk("--> %s returns %d\n", __func__, status);
+	return status;
+}
+
+static void _filelayout_free_lseg(struct nfs4_filelayout_segment *fl)
+{
+	int i;
+
+	if (fl->fh_array) {
+		for (i = 0; i < fl->num_fh; i++) {
+			if (!fl->fh_array[i])
+				break;
+			kfree(fl->fh_array[i]);
+		}
+		kfree(fl->fh_array);
+	}
+	kfree(fl);
+}
+
+static int
+filelayout_decode_layout(struct pnfs_layout_hdr *flo,
+			 struct nfs4_filelayout_segment *fl,
+			 struct nfs4_layoutget_res *lgr,
+			 gfp_t gfp_flags)
+{
+	struct xdr_stream stream;
+	struct xdr_buf buf;
+	struct page *scratch;
+	__be32 *p;
+	uint32_t nfl_util;
+	int i;
+
+	dprintk("%s: set_layout_map Begin\n", __func__);
+
+	scratch = alloc_page(gfp_flags);
+	if (!scratch)
+		return -ENOMEM;
+
+	xdr_init_decode_pages(&stream, &buf, lgr->layoutp->pages, lgr->layoutp->len);
+	xdr_set_scratch_buffer(&stream, page_address(scratch), PAGE_SIZE);
+
+	/* 20 = ufl_util (4), first_stripe_index (4), pattern_offset (8),
+	 * num_fh (4) */
+	p = xdr_inline_decode(&stream, NFS4_DEVICEID4_SIZE + 20);
+	if (unlikely(!p))
+		goto out_err;
+
+	memcpy(&fl->deviceid, p, sizeof(fl->deviceid));
+	p += XDR_QUADLEN(NFS4_DEVICEID4_SIZE);
+	nfs4_print_deviceid(&fl->deviceid);
+
+	nfl_util = be32_to_cpup(p++);
+	if (nfl_util & NFL4_UFLG_COMMIT_THRU_MDS)
+		fl->commit_through_mds = 1;
+	if (nfl_util & NFL4_UFLG_DENSE)
+		fl->stripe_type = STRIPE_DENSE;
+	else
+		fl->stripe_type = STRIPE_SPARSE;
+	fl->stripe_unit = nfl_util & ~NFL4_UFLG_MASK;
+
+	fl->first_stripe_index = be32_to_cpup(p++);
+	p = xdr_decode_hyper(p, &fl->pattern_offset);
+	fl->num_fh = be32_to_cpup(p++);
+
+	dprintk("%s: nfl_util 0x%X num_fh %u fsi %u po %llu\n",
+		__func__, nfl_util, fl->num_fh, fl->first_stripe_index,
+		fl->pattern_offset);
+
+	/* Note that a zero value for num_fh is legal for STRIPE_SPARSE.
+	 * Futher checking is done in filelayout_check_layout */
+	if (fl->num_fh >
+	    max(NFS4_PNFS_MAX_STRIPE_CNT, NFS4_PNFS_MAX_MULTI_CNT))
+		goto out_err;
+
+	if (fl->num_fh > 0) {
+		fl->fh_array = kcalloc(fl->num_fh, sizeof(fl->fh_array[0]),
+				       gfp_flags);
+		if (!fl->fh_array)
+			goto out_err;
+	}
+
+	for (i = 0; i < fl->num_fh; i++) {
+		/* Do we want to use a mempool here? */
+		fl->fh_array[i] = kmalloc(sizeof(struct nfs_fh), gfp_flags);
+		if (!fl->fh_array[i])
+			goto out_err;
+
+		p = xdr_inline_decode(&stream, 4);
+		if (unlikely(!p))
+			goto out_err;
+		fl->fh_array[i]->size = be32_to_cpup(p++);
+		if (fl->fh_array[i]->size > NFS_MAXFHSIZE) {
+			printk(KERN_ERR "NFS: Too big fh %d received %d\n",
+			       i, fl->fh_array[i]->size);
+			goto out_err;
+		}
+
+		p = xdr_inline_decode(&stream, fl->fh_array[i]->size);
+		if (unlikely(!p))
+			goto out_err;
+		memcpy(fl->fh_array[i]->data, p, fl->fh_array[i]->size);
+		dprintk("DEBUG: %s: fh len %d\n", __func__,
+			fl->fh_array[i]->size);
+	}
+
+	__free_page(scratch);
+	return 0;
+
+out_err:
+	__free_page(scratch);
+	return -EIO;
+}
+
+static void
+filelayout_free_lseg(struct pnfs_layout_segment *lseg)
+{
+	struct nfs4_filelayout_segment *fl = FILELAYOUT_LSEG(lseg);
+
+	dprintk("--> %s\n", __func__);
+	if (fl->dsaddr != NULL)
+		nfs4_fl_put_deviceid(fl->dsaddr);
+	/* This assumes a single RW lseg */
+	if (lseg->pls_range.iomode == IOMODE_RW) {
+		struct nfs4_filelayout *flo;
+		struct inode *inode;
+
+		flo = FILELAYOUT_FROM_HDR(lseg->pls_layout);
+		inode = flo->generic_hdr.plh_inode;
+		spin_lock(&inode->i_lock);
+		pnfs_generic_ds_cinfo_release_lseg(&flo->commit_info, lseg);
+		spin_unlock(&inode->i_lock);
+	}
+	_filelayout_free_lseg(fl);
+}
+
+static struct pnfs_layout_segment *
+filelayout_alloc_lseg(struct pnfs_layout_hdr *layoutid,
+		      struct nfs4_layoutget_res *lgr,
+		      gfp_t gfp_flags)
+{
+	struct nfs4_filelayout_segment *fl;
+	int rc;
+
+	dprintk("--> %s\n", __func__);
+	fl = kzalloc(sizeof(*fl), gfp_flags);
+	if (!fl)
+		return NULL;
+
+	rc = filelayout_decode_layout(layoutid, fl, lgr, gfp_flags);
+	if (rc != 0 || filelayout_check_layout(layoutid, fl, lgr, gfp_flags)) {
+		_filelayout_free_lseg(fl);
+		return NULL;
+	}
+	return &fl->generic_hdr;
+}
+
+static bool
+filelayout_lseg_is_striped(const struct nfs4_filelayout_segment *flseg)
+{
+	return flseg->num_fh > 1;
+}
+
+/*
+ * filelayout_pg_test(). Called by nfs_can_coalesce_requests()
+ *
+ * Return 0 if @req cannot be coalesced into @pgio, otherwise return the number
+ * of bytes (maximum @req->wb_bytes) that can be coalesced.
+ */
+static size_t
+filelayout_pg_test(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev,
+		   struct nfs_page *req)
+{
+	unsigned int size;
+	u64 p_stripe, r_stripe;
+	u32 stripe_offset;
+	u64 segment_offset = pgio->pg_lseg->pls_range.offset;
+	u32 stripe_unit = FILELAYOUT_LSEG(pgio->pg_lseg)->stripe_unit;
+
+	/* calls nfs_generic_pg_test */
+	size = pnfs_generic_pg_test(pgio, prev, req);
+	if (!size)
+		return 0;
+	else if (!filelayout_lseg_is_striped(FILELAYOUT_LSEG(pgio->pg_lseg)))
+		return size;
+
+	/* see if req and prev are in the same stripe */
+	if (prev) {
+		p_stripe = (u64)req_offset(prev) - segment_offset;
+		r_stripe = (u64)req_offset(req) - segment_offset;
+		do_div(p_stripe, stripe_unit);
+		do_div(r_stripe, stripe_unit);
+
+		if (p_stripe != r_stripe)
+			return 0;
+	}
+
+	/* calculate remaining bytes in the current stripe */
+	div_u64_rem((u64)req_offset(req) - segment_offset,
+			stripe_unit,
+			&stripe_offset);
+	WARN_ON_ONCE(stripe_offset > stripe_unit);
+	if (stripe_offset >= stripe_unit)
+		return 0;
+	return min(stripe_unit - (unsigned int)stripe_offset, size);
+}
+
+static struct pnfs_layout_segment *
+fl_pnfs_update_layout(struct inode *ino,
+		      struct nfs_open_context *ctx,
+		      loff_t pos,
+		      u64 count,
+		      enum pnfs_iomode iomode,
+		      bool strict_iomode,
+		      gfp_t gfp_flags)
+{
+	struct pnfs_layout_segment *lseg = NULL;
+	struct pnfs_layout_hdr *lo;
+	struct nfs4_filelayout_segment *fl;
+	int status;
+
+	lseg = pnfs_update_layout(ino, ctx, pos, count, iomode, strict_iomode,
+				  gfp_flags);
+	if (IS_ERR_OR_NULL(lseg))
+		goto out;
+
+	lo = NFS_I(ino)->layout;
+	fl = FILELAYOUT_LSEG(lseg);
+
+	status = filelayout_check_deviceid(lo, fl, gfp_flags);
+	if (status) {
+		pnfs_put_lseg(lseg);
+		lseg = NULL;
+	}
+out:
+	return lseg;
+}
+
+static void
+filelayout_pg_init_read(struct nfs_pageio_descriptor *pgio,
+			struct nfs_page *req)
+{
+	pnfs_generic_pg_check_layout(pgio);
+	if (!pgio->pg_lseg) {
+		pgio->pg_lseg = fl_pnfs_update_layout(pgio->pg_inode,
+						      nfs_req_openctx(req),
+						      0,
+						      NFS4_MAX_UINT64,
+						      IOMODE_READ,
+						      false,
+						      GFP_KERNEL);
+		if (IS_ERR(pgio->pg_lseg)) {
+			pgio->pg_error = PTR_ERR(pgio->pg_lseg);
+			pgio->pg_lseg = NULL;
+			return;
+		}
+	}
+	/* If no lseg, fall back to read through mds */
+	if (pgio->pg_lseg == NULL)
+		nfs_pageio_reset_read_mds(pgio);
+}
+
+static void
+filelayout_pg_init_write(struct nfs_pageio_descriptor *pgio,
+			 struct nfs_page *req)
+{
+	pnfs_generic_pg_check_layout(pgio);
+	if (!pgio->pg_lseg) {
+		pgio->pg_lseg = fl_pnfs_update_layout(pgio->pg_inode,
+						      nfs_req_openctx(req),
+						      0,
+						      NFS4_MAX_UINT64,
+						      IOMODE_RW,
+						      false,
+						      GFP_NOFS);
+		if (IS_ERR(pgio->pg_lseg)) {
+			pgio->pg_error = PTR_ERR(pgio->pg_lseg);
+			pgio->pg_lseg = NULL;
+			return;
+		}
+	}
+
+	/* If no lseg, fall back to write through mds */
+	if (pgio->pg_lseg == NULL)
+		nfs_pageio_reset_write_mds(pgio);
+}
+
+static const struct nfs_pageio_ops filelayout_pg_read_ops = {
+	.pg_init = filelayout_pg_init_read,
+	.pg_test = filelayout_pg_test,
+	.pg_doio = pnfs_generic_pg_readpages,
+	.pg_cleanup = pnfs_generic_pg_cleanup,
+};
+
+static const struct nfs_pageio_ops filelayout_pg_write_ops = {
+	.pg_init = filelayout_pg_init_write,
+	.pg_test = filelayout_pg_test,
+	.pg_doio = pnfs_generic_pg_writepages,
+	.pg_cleanup = pnfs_generic_pg_cleanup,
+};
+
+static u32 select_bucket_index(struct nfs4_filelayout_segment *fl, u32 j)
+{
+	if (fl->stripe_type == STRIPE_SPARSE)
+		return nfs4_fl_calc_ds_index(&fl->generic_hdr, j);
+	else
+		return j;
+}
+
+static void
+filelayout_mark_request_commit(struct nfs_page *req,
+			       struct pnfs_layout_segment *lseg,
+			       struct nfs_commit_info *cinfo,
+			       u32 ds_commit_idx)
+
+{
+	struct nfs4_filelayout_segment *fl = FILELAYOUT_LSEG(lseg);
+	u32 i, j;
+
+	if (fl->commit_through_mds) {
+		nfs_request_add_commit_list(req, cinfo);
+	} else {
+		/* Note that we are calling nfs4_fl_calc_j_index on each page
+		 * that ends up being committed to a data server.  An attractive
+		 * alternative is to add a field to nfs_write_data and nfs_page
+		 * to store the value calculated in filelayout_write_pagelist
+		 * and just use that here.
+		 */
+		j = nfs4_fl_calc_j_index(lseg, req_offset(req));
+		i = select_bucket_index(fl, j);
+		pnfs_layout_mark_request_commit(req, lseg, cinfo, i);
+	}
+}
+
+static u32 calc_ds_index_from_commit(struct pnfs_layout_segment *lseg, u32 i)
+{
+	struct nfs4_filelayout_segment *flseg = FILELAYOUT_LSEG(lseg);
+
+	if (flseg->stripe_type == STRIPE_SPARSE)
+		return i;
+	else
+		return nfs4_fl_calc_ds_index(lseg, i);
+}
+
+static struct nfs_fh *
+select_ds_fh_from_commit(struct pnfs_layout_segment *lseg, u32 i)
+{
+	struct nfs4_filelayout_segment *flseg = FILELAYOUT_LSEG(lseg);
+
+	if (flseg->stripe_type == STRIPE_SPARSE) {
+		if (flseg->num_fh == 1)
+			i = 0;
+		else if (flseg->num_fh == 0)
+			/* Use the MDS OPEN fh set in nfs_read_rpcsetup */
+			return NULL;
+	}
+	return flseg->fh_array[i];
+}
+
+static int filelayout_initiate_commit(struct nfs_commit_data *data, int how)
+{
+	struct pnfs_layout_segment *lseg = data->lseg;
+	struct nfs4_pnfs_ds *ds;
+	struct rpc_clnt *ds_clnt;
+	u32 idx;
+	struct nfs_fh *fh;
+
+	idx = calc_ds_index_from_commit(lseg, data->ds_commit_index);
+	ds = nfs4_fl_prepare_ds(lseg, idx);
+	if (!ds)
+		goto out_err;
+
+	ds_clnt = nfs4_find_or_create_ds_client(ds->ds_clp, data->inode);
+	if (IS_ERR(ds_clnt))
+		goto out_err;
+
+	dprintk("%s ino %lu, how %d cl_count %d\n", __func__,
+		data->inode->i_ino, how, refcount_read(&ds->ds_clp->cl_count));
+	data->commit_done_cb = filelayout_commit_done_cb;
+	refcount_inc(&ds->ds_clp->cl_count);
+	data->ds_clp = ds->ds_clp;
+	fh = select_ds_fh_from_commit(lseg, data->ds_commit_index);
+	if (fh)
+		data->args.fh = fh;
+	return nfs_initiate_commit(ds_clnt, data, NFS_PROTO(data->inode),
+				   &filelayout_commit_call_ops, how,
+				   RPC_TASK_SOFTCONN);
+out_err:
+	pnfs_generic_prepare_to_resend_writes(data);
+	pnfs_generic_commit_release(data);
+	return -EAGAIN;
+}
+
+static int
+filelayout_commit_pagelist(struct inode *inode, struct list_head *mds_pages,
+			   int how, struct nfs_commit_info *cinfo)
+{
+	return pnfs_generic_commit_pagelist(inode, mds_pages, how, cinfo,
+					    filelayout_initiate_commit);
+}
+
+static struct nfs4_deviceid_node *
+filelayout_alloc_deviceid_node(struct nfs_server *server,
+		struct pnfs_device *pdev, gfp_t gfp_flags)
+{
+	struct nfs4_file_layout_dsaddr *dsaddr;
+
+	dsaddr = nfs4_fl_alloc_deviceid_node(server, pdev, gfp_flags);
+	if (!dsaddr)
+		return NULL;
+	return &dsaddr->id_node;
+}
+
+static void
+filelayout_free_deviceid_node(struct nfs4_deviceid_node *d)
+{
+	nfs4_fl_free_deviceid(container_of(d, struct nfs4_file_layout_dsaddr, id_node));
+}
+
+static struct pnfs_layout_hdr *
+filelayout_alloc_layout_hdr(struct inode *inode, gfp_t gfp_flags)
+{
+	struct nfs4_filelayout *flo;
+
+	flo = kzalloc(sizeof(*flo), gfp_flags);
+	if (flo == NULL)
+		return NULL;
+	pnfs_init_ds_commit_info(&flo->commit_info);
+	flo->commit_info.ops = &filelayout_commit_ops;
+	return &flo->generic_hdr;
+}
+
+static void
+filelayout_free_layout_hdr(struct pnfs_layout_hdr *lo)
+{
+	kfree_rcu(FILELAYOUT_FROM_HDR(lo), generic_hdr.plh_rcu);
+}
+
+static struct pnfs_ds_commit_info *
+filelayout_get_ds_info(struct inode *inode)
+{
+	struct pnfs_layout_hdr *layout = NFS_I(inode)->layout;
+
+	if (layout == NULL)
+		return NULL;
+	else
+		return &FILELAYOUT_FROM_HDR(layout)->commit_info;
+}
+
+static void
+filelayout_setup_ds_info(struct pnfs_ds_commit_info *fl_cinfo,
+		struct pnfs_layout_segment *lseg)
+{
+	struct nfs4_filelayout_segment *fl = FILELAYOUT_LSEG(lseg);
+	struct inode *inode = lseg->pls_layout->plh_inode;
+	struct pnfs_commit_array *array, *new;
+	unsigned int size = (fl->stripe_type == STRIPE_SPARSE) ?
+		fl->dsaddr->ds_num : fl->dsaddr->stripe_count;
+
+	new = pnfs_alloc_commit_array(size, GFP_NOIO);
+	if (new) {
+		spin_lock(&inode->i_lock);
+		array = pnfs_add_commit_array(fl_cinfo, new, lseg);
+		spin_unlock(&inode->i_lock);
+		if (array != new)
+			pnfs_free_commit_array(new);
+	}
+}
+
+static void
+filelayout_release_ds_info(struct pnfs_ds_commit_info *fl_cinfo,
+		struct inode *inode)
+{
+	spin_lock(&inode->i_lock);
+	pnfs_generic_ds_cinfo_destroy(fl_cinfo);
+	spin_unlock(&inode->i_lock);
+}
+
+static const struct pnfs_commit_ops filelayout_commit_ops = {
+	.setup_ds_info		= filelayout_setup_ds_info,
+	.release_ds_info	= filelayout_release_ds_info,
+	.mark_request_commit	= filelayout_mark_request_commit,
+	.clear_request_commit	= pnfs_generic_clear_request_commit,
+	.scan_commit_lists	= pnfs_generic_scan_commit_lists,
+	.recover_commit_reqs	= pnfs_generic_recover_commit_reqs,
+	.search_commit_reqs	= pnfs_generic_search_commit_reqs,
+	.commit_pagelist	= filelayout_commit_pagelist,
+};
+
+static struct pnfs_layoutdriver_type filelayout_type = {
+	.id			= LAYOUT_NFSV4_1_FILES,
+	.name			= "LAYOUT_NFSV4_1_FILES",
+	.owner			= THIS_MODULE,
+	.flags			= PNFS_LAYOUTGET_ON_OPEN,
+	.max_layoutget_response	= 4096, /* 1 page or so... */
+	.alloc_layout_hdr	= filelayout_alloc_layout_hdr,
+	.free_layout_hdr	= filelayout_free_layout_hdr,
+	.alloc_lseg		= filelayout_alloc_lseg,
+	.free_lseg		= filelayout_free_lseg,
+	.pg_read_ops		= &filelayout_pg_read_ops,
+	.pg_write_ops		= &filelayout_pg_write_ops,
+	.get_ds_info		= &filelayout_get_ds_info,
+	.read_pagelist		= filelayout_read_pagelist,
+	.write_pagelist		= filelayout_write_pagelist,
+	.alloc_deviceid_node	= filelayout_alloc_deviceid_node,
+	.free_deviceid_node	= filelayout_free_deviceid_node,
+	.sync			= pnfs_nfs_generic_sync,
+};
+
+static int __init nfs4filelayout_init(void)
+{
+	printk(KERN_INFO "%s: NFSv4 File Layout Driver Registering...\n",
+	       __func__);
+	return pnfs_register_layoutdriver(&filelayout_type);
+}
+
+static void __exit nfs4filelayout_exit(void)
+{
+	printk(KERN_INFO "%s: NFSv4 File Layout Driver Unregistering...\n",
+	       __func__);
+	pnfs_unregister_layoutdriver(&filelayout_type);
+}
+
+MODULE_ALIAS("nfs-layouttype4-1");
+
+module_init(nfs4filelayout_init);
+module_exit(nfs4filelayout_exit);
diff --git a/fs/nfs/filelayout/filelayout.h b/fs/nfs/filelayout/filelayout.h
new file mode 100644
index 000000000..79323b5da
--- /dev/null
+++ b/fs/nfs/filelayout/filelayout.h
@@ -0,0 +1,118 @@
+/*
+ *  NFSv4 file layout driver data structures.
+ *
+ *  Copyright (c) 2002
+ *  The Regents of the University of Michigan
+ *  All Rights Reserved
+ *
+ *  Dean Hildebrand <dhildebz@umich.edu>
+ *
+ *  Permission is granted to use, copy, create derivative works, and
+ *  redistribute this software and such derivative works for any purpose,
+ *  so long as the name of the University of Michigan is not used in
+ *  any advertising or publicity pertaining to the use or distribution
+ *  of this software without specific, written prior authorization. If
+ *  the above copyright notice or any other identification of the
+ *  University of Michigan is included in any copy of any portion of
+ *  this software, then the disclaimer below must also be included.
+ *
+ *  This software is provided as is, without representation or warranty
+ *  of any kind either express or implied, including without limitation
+ *  the implied warranties of merchantability, fitness for a particular
+ *  purpose, or noninfringement.  The Regents of the University of
+ *  Michigan shall not be liable for any damages, including special,
+ *  indirect, incidental, or consequential damages, with respect to any
+ *  claim arising out of or in connection with the use of the software,
+ *  even if it has been or is hereafter advised of the possibility of
+ *  such damages.
+ */
+
+#ifndef FS_NFS_NFS4FILELAYOUT_H
+#define FS_NFS_NFS4FILELAYOUT_H
+
+#include "../pnfs.h"
+
+/*
+ * Field testing shows we need to support up to 4096 stripe indices.
+ * We store each index as a u8 (u32 on the wire) to keep the memory footprint
+ * reasonable. This in turn means we support a maximum of 256
+ * RFC 5661 multipath_list4 structures.
+ */
+#define NFS4_PNFS_MAX_STRIPE_CNT 4096
+#define NFS4_PNFS_MAX_MULTI_CNT  256 /* 256 fit into a u8 stripe_index */
+
+enum stripetype4 {
+	STRIPE_SPARSE = 1,
+	STRIPE_DENSE = 2
+};
+
+struct nfs4_file_layout_dsaddr {
+	struct nfs4_deviceid_node	id_node;
+	u32				stripe_count;
+	u8				*stripe_indices;
+	u32				ds_num;
+	struct nfs4_pnfs_ds		*ds_list[1];
+};
+
+struct nfs4_filelayout_segment {
+	struct pnfs_layout_segment	generic_hdr;
+	u32				stripe_type;
+	u32				commit_through_mds;
+	u32				stripe_unit;
+	u32				first_stripe_index;
+	u64				pattern_offset;
+	struct nfs4_deviceid		deviceid;
+	struct nfs4_file_layout_dsaddr	*dsaddr; /* Point to GETDEVINFO data */
+	unsigned int			num_fh;
+	struct nfs_fh			**fh_array;
+};
+
+struct nfs4_filelayout {
+	struct pnfs_layout_hdr generic_hdr;
+	struct pnfs_ds_commit_info commit_info;
+};
+
+static inline struct nfs4_filelayout *
+FILELAYOUT_FROM_HDR(struct pnfs_layout_hdr *lo)
+{
+	return container_of(lo, struct nfs4_filelayout, generic_hdr);
+}
+
+static inline struct nfs4_filelayout_segment *
+FILELAYOUT_LSEG(struct pnfs_layout_segment *lseg)
+{
+	return container_of(lseg,
+			    struct nfs4_filelayout_segment,
+			    generic_hdr);
+}
+
+static inline struct nfs4_deviceid_node *
+FILELAYOUT_DEVID_NODE(struct pnfs_layout_segment *lseg)
+{
+	return &FILELAYOUT_LSEG(lseg)->dsaddr->id_node;
+}
+
+static inline bool
+filelayout_test_devid_invalid(struct nfs4_deviceid_node *node)
+{
+	return test_bit(NFS_DEVICEID_INVALID, &node->flags);
+}
+
+extern bool
+filelayout_test_devid_unavailable(struct nfs4_deviceid_node *node);
+
+extern struct nfs_fh *
+nfs4_fl_select_ds_fh(struct pnfs_layout_segment *lseg, u32 j);
+
+u32 nfs4_fl_calc_j_index(struct pnfs_layout_segment *lseg, loff_t offset);
+u32 nfs4_fl_calc_ds_index(struct pnfs_layout_segment *lseg, u32 j);
+struct nfs4_pnfs_ds *nfs4_fl_prepare_ds(struct pnfs_layout_segment *lseg,
+					u32 ds_idx);
+
+extern struct nfs4_file_layout_dsaddr *
+nfs4_fl_alloc_deviceid_node(struct nfs_server *server,
+	struct pnfs_device *pdev, gfp_t gfp_flags);
+extern void nfs4_fl_put_deviceid(struct nfs4_file_layout_dsaddr *dsaddr);
+extern void nfs4_fl_free_deviceid(struct nfs4_file_layout_dsaddr *dsaddr);
+
+#endif /* FS_NFS_NFS4FILELAYOUT_H */
diff --git a/fs/nfs/filelayout/filelayoutdev.c b/fs/nfs/filelayout/filelayoutdev.c
new file mode 100644
index 000000000..d913e8188
--- /dev/null
+++ b/fs/nfs/filelayout/filelayoutdev.c
@@ -0,0 +1,305 @@
+/*
+ *  Device operations for the pnfs nfs4 file layout driver.
+ *
+ *  Copyright (c) 2002
+ *  The Regents of the University of Michigan
+ *  All Rights Reserved
+ *
+ *  Dean Hildebrand <dhildebz@umich.edu>
+ *  Garth Goodson   <Garth.Goodson@netapp.com>
+ *
+ *  Permission is granted to use, copy, create derivative works, and
+ *  redistribute this software and such derivative works for any purpose,
+ *  so long as the name of the University of Michigan is not used in
+ *  any advertising or publicity pertaining to the use or distribution
+ *  of this software without specific, written prior authorization. If
+ *  the above copyright notice or any other identification of the
+ *  University of Michigan is included in any copy of any portion of
+ *  this software, then the disclaimer below must also be included.
+ *
+ *  This software is provided as is, without representation or warranty
+ *  of any kind either express or implied, including without limitation
+ *  the implied warranties of merchantability, fitness for a particular
+ *  purpose, or noninfringement.  The Regents of the University of
+ *  Michigan shall not be liable for any damages, including special,
+ *  indirect, incidental, or consequential damages, with respect to any
+ *  claim arising out of or in connection with the use of the software,
+ *  even if it has been or is hereafter advised of the possibility of
+ *  such damages.
+ */
+
+#include <linux/nfs_fs.h>
+#include <linux/vmalloc.h>
+#include <linux/module.h>
+
+#include "../internal.h"
+#include "../nfs4session.h"
+#include "filelayout.h"
+
+#define NFSDBG_FACILITY		NFSDBG_PNFS_LD
+
+static unsigned int dataserver_timeo = NFS4_DEF_DS_TIMEO;
+static unsigned int dataserver_retrans = NFS4_DEF_DS_RETRANS;
+
+void
+nfs4_fl_free_deviceid(struct nfs4_file_layout_dsaddr *dsaddr)
+{
+	struct nfs4_pnfs_ds *ds;
+	int i;
+
+	nfs4_print_deviceid(&dsaddr->id_node.deviceid);
+
+	for (i = 0; i < dsaddr->ds_num; i++) {
+		ds = dsaddr->ds_list[i];
+		if (ds != NULL)
+			nfs4_pnfs_ds_put(ds);
+	}
+	kfree(dsaddr->stripe_indices);
+	kfree_rcu(dsaddr, id_node.rcu);
+}
+
+/* Decode opaque device data and return the result */
+struct nfs4_file_layout_dsaddr *
+nfs4_fl_alloc_deviceid_node(struct nfs_server *server, struct pnfs_device *pdev,
+		gfp_t gfp_flags)
+{
+	int i;
+	u32 cnt, num;
+	u8 *indexp;
+	__be32 *p;
+	u8 *stripe_indices;
+	u8 max_stripe_index;
+	struct nfs4_file_layout_dsaddr *dsaddr = NULL;
+	struct xdr_stream stream;
+	struct xdr_buf buf;
+	struct page *scratch;
+	struct list_head dsaddrs;
+	struct nfs4_pnfs_ds_addr *da;
+
+	/* set up xdr stream */
+	scratch = alloc_page(gfp_flags);
+	if (!scratch)
+		goto out_err;
+
+	xdr_init_decode_pages(&stream, &buf, pdev->pages, pdev->pglen);
+	xdr_set_scratch_buffer(&stream, page_address(scratch), PAGE_SIZE);
+
+	/* Get the stripe count (number of stripe index) */
+	p = xdr_inline_decode(&stream, 4);
+	if (unlikely(!p))
+		goto out_err_free_scratch;
+
+	cnt = be32_to_cpup(p);
+	dprintk("%s stripe count  %d\n", __func__, cnt);
+	if (cnt > NFS4_PNFS_MAX_STRIPE_CNT) {
+		printk(KERN_WARNING "NFS: %s: stripe count %d greater than "
+		       "supported maximum %d\n", __func__,
+			cnt, NFS4_PNFS_MAX_STRIPE_CNT);
+		goto out_err_free_scratch;
+	}
+
+	/* read stripe indices */
+	stripe_indices = kcalloc(cnt, sizeof(u8), gfp_flags);
+	if (!stripe_indices)
+		goto out_err_free_scratch;
+
+	p = xdr_inline_decode(&stream, cnt << 2);
+	if (unlikely(!p))
+		goto out_err_free_stripe_indices;
+
+	indexp = &stripe_indices[0];
+	max_stripe_index = 0;
+	for (i = 0; i < cnt; i++) {
+		*indexp = be32_to_cpup(p++);
+		max_stripe_index = max(max_stripe_index, *indexp);
+		indexp++;
+	}
+
+	/* Check the multipath list count */
+	p = xdr_inline_decode(&stream, 4);
+	if (unlikely(!p))
+		goto out_err_free_stripe_indices;
+
+	num = be32_to_cpup(p);
+	dprintk("%s ds_num %u\n", __func__, num);
+	if (num > NFS4_PNFS_MAX_MULTI_CNT) {
+		printk(KERN_WARNING "NFS: %s: multipath count %d greater than "
+			"supported maximum %d\n", __func__,
+			num, NFS4_PNFS_MAX_MULTI_CNT);
+		goto out_err_free_stripe_indices;
+	}
+
+	/* validate stripe indices are all < num */
+	if (max_stripe_index >= num) {
+		printk(KERN_WARNING "NFS: %s: stripe index %u >= num ds %u\n",
+			__func__, max_stripe_index, num);
+		goto out_err_free_stripe_indices;
+	}
+
+	dsaddr = kzalloc(sizeof(*dsaddr) +
+			(sizeof(struct nfs4_pnfs_ds *) * (num - 1)),
+			gfp_flags);
+	if (!dsaddr)
+		goto out_err_free_stripe_indices;
+
+	dsaddr->stripe_count = cnt;
+	dsaddr->stripe_indices = stripe_indices;
+	stripe_indices = NULL;
+	dsaddr->ds_num = num;
+	nfs4_init_deviceid_node(&dsaddr->id_node, server, &pdev->dev_id);
+
+	INIT_LIST_HEAD(&dsaddrs);
+
+	for (i = 0; i < dsaddr->ds_num; i++) {
+		int j;
+		u32 mp_count;
+
+		p = xdr_inline_decode(&stream, 4);
+		if (unlikely(!p))
+			goto out_err_free_deviceid;
+
+		mp_count = be32_to_cpup(p); /* multipath count */
+		for (j = 0; j < mp_count; j++) {
+			da = nfs4_decode_mp_ds_addr(server->nfs_client->cl_net,
+						    &stream, gfp_flags);
+			if (da)
+				list_add_tail(&da->da_node, &dsaddrs);
+		}
+		if (list_empty(&dsaddrs)) {
+			dprintk("%s: no suitable DS addresses found\n",
+				__func__);
+			goto out_err_free_deviceid;
+		}
+
+		dsaddr->ds_list[i] = nfs4_pnfs_ds_add(&dsaddrs, gfp_flags);
+		if (!dsaddr->ds_list[i])
+			goto out_err_drain_dsaddrs;
+
+		/* If DS was already in cache, free ds addrs */
+		while (!list_empty(&dsaddrs)) {
+			da = list_first_entry(&dsaddrs,
+					      struct nfs4_pnfs_ds_addr,
+					      da_node);
+			list_del_init(&da->da_node);
+			kfree(da->da_remotestr);
+			kfree(da);
+		}
+	}
+
+	__free_page(scratch);
+	return dsaddr;
+
+out_err_drain_dsaddrs:
+	while (!list_empty(&dsaddrs)) {
+		da = list_first_entry(&dsaddrs, struct nfs4_pnfs_ds_addr,
+				      da_node);
+		list_del_init(&da->da_node);
+		kfree(da->da_remotestr);
+		kfree(da);
+	}
+out_err_free_deviceid:
+	nfs4_fl_free_deviceid(dsaddr);
+	/* stripe_indicies was part of dsaddr */
+	goto out_err_free_scratch;
+out_err_free_stripe_indices:
+	kfree(stripe_indices);
+out_err_free_scratch:
+	__free_page(scratch);
+out_err:
+	dprintk("%s ERROR: returning NULL\n", __func__);
+	return NULL;
+}
+
+void
+nfs4_fl_put_deviceid(struct nfs4_file_layout_dsaddr *dsaddr)
+{
+	nfs4_put_deviceid_node(&dsaddr->id_node);
+}
+
+/*
+ * Want res = (offset - layout->pattern_offset)/ layout->stripe_unit
+ * Then: ((res + fsi) % dsaddr->stripe_count)
+ */
+u32
+nfs4_fl_calc_j_index(struct pnfs_layout_segment *lseg, loff_t offset)
+{
+	struct nfs4_filelayout_segment *flseg = FILELAYOUT_LSEG(lseg);
+	u64 tmp;
+
+	tmp = offset - flseg->pattern_offset;
+	do_div(tmp, flseg->stripe_unit);
+	tmp += flseg->first_stripe_index;
+	return do_div(tmp, flseg->dsaddr->stripe_count);
+}
+
+u32
+nfs4_fl_calc_ds_index(struct pnfs_layout_segment *lseg, u32 j)
+{
+	return FILELAYOUT_LSEG(lseg)->dsaddr->stripe_indices[j];
+}
+
+struct nfs_fh *
+nfs4_fl_select_ds_fh(struct pnfs_layout_segment *lseg, u32 j)
+{
+	struct nfs4_filelayout_segment *flseg = FILELAYOUT_LSEG(lseg);
+	u32 i;
+
+	if (flseg->stripe_type == STRIPE_SPARSE) {
+		if (flseg->num_fh == 1)
+			i = 0;
+		else if (flseg->num_fh == 0)
+			/* Use the MDS OPEN fh set in nfs_read_rpcsetup */
+			return NULL;
+		else
+			i = nfs4_fl_calc_ds_index(lseg, j);
+	} else
+		i = j;
+	return flseg->fh_array[i];
+}
+
+/* Upon return, either ds is connected, or ds is NULL */
+struct nfs4_pnfs_ds *
+nfs4_fl_prepare_ds(struct pnfs_layout_segment *lseg, u32 ds_idx)
+{
+	struct nfs4_file_layout_dsaddr *dsaddr = FILELAYOUT_LSEG(lseg)->dsaddr;
+	struct nfs4_pnfs_ds *ds = dsaddr->ds_list[ds_idx];
+	struct nfs4_deviceid_node *devid = FILELAYOUT_DEVID_NODE(lseg);
+	struct nfs4_pnfs_ds *ret = ds;
+	struct nfs_server *s = NFS_SERVER(lseg->pls_layout->plh_inode);
+	int status;
+
+	if (ds == NULL) {
+		printk(KERN_ERR "NFS: %s: No data server for offset index %d\n",
+			__func__, ds_idx);
+		pnfs_generic_mark_devid_invalid(devid);
+		goto out;
+	}
+	smp_rmb();
+	if (ds->ds_clp)
+		goto out_test_devid;
+
+	status = nfs4_pnfs_ds_connect(s, ds, devid, dataserver_timeo,
+			     dataserver_retrans, 4,
+			     s->nfs_client->cl_minorversion);
+	if (status) {
+		nfs4_mark_deviceid_unavailable(devid);
+		ret = NULL;
+		goto out;
+	}
+
+out_test_devid:
+	if (ret->ds_clp == NULL ||
+	    filelayout_test_devid_unavailable(devid))
+		ret = NULL;
+out:
+	return ret;
+}
+
+module_param(dataserver_retrans, uint, 0644);
+MODULE_PARM_DESC(dataserver_retrans, "The  number of times the NFSv4.1 client "
+			"retries a request before it attempts further "
+			" recovery  action.");
+module_param(dataserver_timeo, uint, 0644);
+MODULE_PARM_DESC(dataserver_timeo, "The time (in tenths of a second) the "
+			"NFSv4.1  client  waits for a response from a "
+			" data server before it retries an NFS request.");
diff --git a/fs/nfs/flexfilelayout/Makefile b/fs/nfs/flexfilelayout/Makefile
new file mode 100644
index 000000000..49f03422b
--- /dev/null
+++ b/fs/nfs/flexfilelayout/Makefile
@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Makefile for the pNFS Flexfile Layout Driver kernel module
+#
+obj-$(CONFIG_PNFS_FLEXFILE_LAYOUT) += nfs_layout_flexfiles.o
+nfs_layout_flexfiles-y := flexfilelayout.o flexfilelayoutdev.o
diff --git a/fs/nfs/flexfilelayout/flexfilelayout.c b/fs/nfs/flexfilelayout/flexfilelayout.c
new file mode 100644
index 000000000..e4f2820ba
--- /dev/null
+++ b/fs/nfs/flexfilelayout/flexfilelayout.c
@@ -0,0 +1,2545 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Module for pnfs flexfile layout driver.
+ *
+ * Copyright (c) 2014, Primary Data, Inc. All rights reserved.
+ *
+ * Tao Peng <bergwolf@primarydata.com>
+ */
+
+#include <linux/nfs_fs.h>
+#include <linux/nfs_mount.h>
+#include <linux/nfs_page.h>
+#include <linux/module.h>
+#include <linux/sched/mm.h>
+
+#include <linux/sunrpc/metrics.h>
+
+#include "flexfilelayout.h"
+#include "../nfs4session.h"
+#include "../nfs4idmap.h"
+#include "../internal.h"
+#include "../delegation.h"
+#include "../nfs4trace.h"
+#include "../iostat.h"
+#include "../nfs.h"
+#include "../nfs42.h"
+
+#define NFSDBG_FACILITY         NFSDBG_PNFS_LD
+
+#define FF_LAYOUT_POLL_RETRY_MAX     (15*HZ)
+#define FF_LAYOUTRETURN_MAXERR 20
+
+static unsigned short io_maxretrans;
+
+static const struct pnfs_commit_ops ff_layout_commit_ops;
+static void ff_layout_read_record_layoutstats_done(struct rpc_task *task,
+		struct nfs_pgio_header *hdr);
+static int ff_layout_mirror_prepare_stats(struct pnfs_layout_hdr *lo,
+			       struct nfs42_layoutstat_devinfo *devinfo,
+			       int dev_limit);
+static void ff_layout_encode_ff_layoutupdate(struct xdr_stream *xdr,
+			      const struct nfs42_layoutstat_devinfo *devinfo,
+			      struct nfs4_ff_layout_mirror *mirror);
+
+static struct pnfs_layout_hdr *
+ff_layout_alloc_layout_hdr(struct inode *inode, gfp_t gfp_flags)
+{
+	struct nfs4_flexfile_layout *ffl;
+
+	ffl = kzalloc(sizeof(*ffl), gfp_flags);
+	if (ffl) {
+		pnfs_init_ds_commit_info(&ffl->commit_info);
+		INIT_LIST_HEAD(&ffl->error_list);
+		INIT_LIST_HEAD(&ffl->mirrors);
+		ffl->last_report_time = ktime_get();
+		ffl->commit_info.ops = &ff_layout_commit_ops;
+		return &ffl->generic_hdr;
+	} else
+		return NULL;
+}
+
+static void
+ff_layout_free_layout_hdr(struct pnfs_layout_hdr *lo)
+{
+	struct nfs4_flexfile_layout *ffl = FF_LAYOUT_FROM_HDR(lo);
+	struct nfs4_ff_layout_ds_err *err, *n;
+
+	list_for_each_entry_safe(err, n, &ffl->error_list, list) {
+		list_del(&err->list);
+		kfree(err);
+	}
+	kfree_rcu(ffl, generic_hdr.plh_rcu);
+}
+
+static int decode_pnfs_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
+{
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, NFS4_STATEID_SIZE);
+	if (unlikely(p == NULL))
+		return -ENOBUFS;
+	stateid->type = NFS4_PNFS_DS_STATEID_TYPE;
+	memcpy(stateid->data, p, NFS4_STATEID_SIZE);
+	dprintk("%s: stateid id= [%x%x%x%x]\n", __func__,
+		p[0], p[1], p[2], p[3]);
+	return 0;
+}
+
+static int decode_deviceid(struct xdr_stream *xdr, struct nfs4_deviceid *devid)
+{
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, NFS4_DEVICEID4_SIZE);
+	if (unlikely(!p))
+		return -ENOBUFS;
+	memcpy(devid, p, NFS4_DEVICEID4_SIZE);
+	nfs4_print_deviceid(devid);
+	return 0;
+}
+
+static int decode_nfs_fh(struct xdr_stream *xdr, struct nfs_fh *fh)
+{
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(!p))
+		return -ENOBUFS;
+	fh->size = be32_to_cpup(p++);
+	if (fh->size > NFS_MAXFHSIZE) {
+		printk(KERN_ERR "NFS flexfiles: Too big fh received %d\n",
+		       fh->size);
+		return -EOVERFLOW;
+	}
+	/* fh.data */
+	p = xdr_inline_decode(xdr, fh->size);
+	if (unlikely(!p))
+		return -ENOBUFS;
+	memcpy(&fh->data, p, fh->size);
+	dprintk("%s: fh len %d\n", __func__, fh->size);
+
+	return 0;
+}
+
+/*
+ * Currently only stringified uids and gids are accepted.
+ * I.e., kerberos is not supported to the DSes, so no pricipals.
+ *
+ * That means that one common function will suffice, but when
+ * principals are added, this should be split to accomodate
+ * calls to both nfs_map_name_to_uid() and nfs_map_group_to_gid().
+ */
+static int
+decode_name(struct xdr_stream *xdr, u32 *id)
+{
+	__be32 *p;
+	int len;
+
+	/* opaque_length(4)*/
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(!p))
+		return -ENOBUFS;
+	len = be32_to_cpup(p++);
+	if (len < 0)
+		return -EINVAL;
+
+	dprintk("%s: len %u\n", __func__, len);
+
+	/* opaque body */
+	p = xdr_inline_decode(xdr, len);
+	if (unlikely(!p))
+		return -ENOBUFS;
+
+	if (!nfs_map_string_to_numeric((char *)p, len, id))
+		return -EINVAL;
+
+	return 0;
+}
+
+static bool ff_mirror_match_fh(const struct nfs4_ff_layout_mirror *m1,
+		const struct nfs4_ff_layout_mirror *m2)
+{
+	int i, j;
+
+	if (m1->fh_versions_cnt != m2->fh_versions_cnt)
+		return false;
+	for (i = 0; i < m1->fh_versions_cnt; i++) {
+		bool found_fh = false;
+		for (j = 0; j < m2->fh_versions_cnt; j++) {
+			if (nfs_compare_fh(&m1->fh_versions[i],
+					&m2->fh_versions[j]) == 0) {
+				found_fh = true;
+				break;
+			}
+		}
+		if (!found_fh)
+			return false;
+	}
+	return true;
+}
+
+static struct nfs4_ff_layout_mirror *
+ff_layout_add_mirror(struct pnfs_layout_hdr *lo,
+		struct nfs4_ff_layout_mirror *mirror)
+{
+	struct nfs4_flexfile_layout *ff_layout = FF_LAYOUT_FROM_HDR(lo);
+	struct nfs4_ff_layout_mirror *pos;
+	struct inode *inode = lo->plh_inode;
+
+	spin_lock(&inode->i_lock);
+	list_for_each_entry(pos, &ff_layout->mirrors, mirrors) {
+		if (memcmp(&mirror->devid, &pos->devid, sizeof(pos->devid)) != 0)
+			continue;
+		if (!ff_mirror_match_fh(mirror, pos))
+			continue;
+		if (refcount_inc_not_zero(&pos->ref)) {
+			spin_unlock(&inode->i_lock);
+			return pos;
+		}
+	}
+	list_add(&mirror->mirrors, &ff_layout->mirrors);
+	mirror->layout = lo;
+	spin_unlock(&inode->i_lock);
+	return mirror;
+}
+
+static void
+ff_layout_remove_mirror(struct nfs4_ff_layout_mirror *mirror)
+{
+	struct inode *inode;
+	if (mirror->layout == NULL)
+		return;
+	inode = mirror->layout->plh_inode;
+	spin_lock(&inode->i_lock);
+	list_del(&mirror->mirrors);
+	spin_unlock(&inode->i_lock);
+	mirror->layout = NULL;
+}
+
+static struct nfs4_ff_layout_mirror *ff_layout_alloc_mirror(gfp_t gfp_flags)
+{
+	struct nfs4_ff_layout_mirror *mirror;
+
+	mirror = kzalloc(sizeof(*mirror), gfp_flags);
+	if (mirror != NULL) {
+		spin_lock_init(&mirror->lock);
+		refcount_set(&mirror->ref, 1);
+		INIT_LIST_HEAD(&mirror->mirrors);
+	}
+	return mirror;
+}
+
+static void ff_layout_free_mirror(struct nfs4_ff_layout_mirror *mirror)
+{
+	const struct cred	*cred;
+
+	ff_layout_remove_mirror(mirror);
+	kfree(mirror->fh_versions);
+	cred = rcu_access_pointer(mirror->ro_cred);
+	put_cred(cred);
+	cred = rcu_access_pointer(mirror->rw_cred);
+	put_cred(cred);
+	nfs4_ff_layout_put_deviceid(mirror->mirror_ds);
+	kfree(mirror);
+}
+
+static void ff_layout_put_mirror(struct nfs4_ff_layout_mirror *mirror)
+{
+	if (mirror != NULL && refcount_dec_and_test(&mirror->ref))
+		ff_layout_free_mirror(mirror);
+}
+
+static void ff_layout_free_mirror_array(struct nfs4_ff_layout_segment *fls)
+{
+	u32 i;
+
+	for (i = 0; i < fls->mirror_array_cnt; i++)
+		ff_layout_put_mirror(fls->mirror_array[i]);
+}
+
+static void _ff_layout_free_lseg(struct nfs4_ff_layout_segment *fls)
+{
+	if (fls) {
+		ff_layout_free_mirror_array(fls);
+		kfree(fls);
+	}
+}
+
+static bool
+ff_lseg_match_mirrors(struct pnfs_layout_segment *l1,
+		struct pnfs_layout_segment *l2)
+{
+	const struct nfs4_ff_layout_segment *fl1 = FF_LAYOUT_LSEG(l1);
+	const struct nfs4_ff_layout_segment *fl2 = FF_LAYOUT_LSEG(l1);
+	u32 i;
+
+	if (fl1->mirror_array_cnt != fl2->mirror_array_cnt)
+		return false;
+	for (i = 0; i < fl1->mirror_array_cnt; i++) {
+		if (fl1->mirror_array[i] != fl2->mirror_array[i])
+			return false;
+	}
+	return true;
+}
+
+static bool
+ff_lseg_range_is_after(const struct pnfs_layout_range *l1,
+		const struct pnfs_layout_range *l2)
+{
+	u64 end1, end2;
+
+	if (l1->iomode != l2->iomode)
+		return l1->iomode != IOMODE_READ;
+	end1 = pnfs_calc_offset_end(l1->offset, l1->length);
+	end2 = pnfs_calc_offset_end(l2->offset, l2->length);
+	if (end1 < l2->offset)
+		return false;
+	if (end2 < l1->offset)
+		return true;
+	return l2->offset <= l1->offset;
+}
+
+static bool
+ff_lseg_merge(struct pnfs_layout_segment *new,
+		struct pnfs_layout_segment *old)
+{
+	u64 new_end, old_end;
+
+	if (test_bit(NFS_LSEG_LAYOUTRETURN, &old->pls_flags))
+		return false;
+	if (new->pls_range.iomode != old->pls_range.iomode)
+		return false;
+	old_end = pnfs_calc_offset_end(old->pls_range.offset,
+			old->pls_range.length);
+	if (old_end < new->pls_range.offset)
+		return false;
+	new_end = pnfs_calc_offset_end(new->pls_range.offset,
+			new->pls_range.length);
+	if (new_end < old->pls_range.offset)
+		return false;
+	if (!ff_lseg_match_mirrors(new, old))
+		return false;
+
+	/* Mergeable: copy info from 'old' to 'new' */
+	if (new_end < old_end)
+		new_end = old_end;
+	if (new->pls_range.offset < old->pls_range.offset)
+		new->pls_range.offset = old->pls_range.offset;
+	new->pls_range.length = pnfs_calc_offset_length(new->pls_range.offset,
+			new_end);
+	if (test_bit(NFS_LSEG_ROC, &old->pls_flags))
+		set_bit(NFS_LSEG_ROC, &new->pls_flags);
+	return true;
+}
+
+static void
+ff_layout_add_lseg(struct pnfs_layout_hdr *lo,
+		struct pnfs_layout_segment *lseg,
+		struct list_head *free_me)
+{
+	pnfs_generic_layout_insert_lseg(lo, lseg,
+			ff_lseg_range_is_after,
+			ff_lseg_merge,
+			free_me);
+}
+
+static void ff_layout_sort_mirrors(struct nfs4_ff_layout_segment *fls)
+{
+	int i, j;
+
+	for (i = 0; i < fls->mirror_array_cnt - 1; i++) {
+		for (j = i + 1; j < fls->mirror_array_cnt; j++)
+			if (fls->mirror_array[i]->efficiency <
+			    fls->mirror_array[j]->efficiency)
+				swap(fls->mirror_array[i],
+				     fls->mirror_array[j]);
+	}
+}
+
+static struct pnfs_layout_segment *
+ff_layout_alloc_lseg(struct pnfs_layout_hdr *lh,
+		     struct nfs4_layoutget_res *lgr,
+		     gfp_t gfp_flags)
+{
+	struct pnfs_layout_segment *ret;
+	struct nfs4_ff_layout_segment *fls = NULL;
+	struct xdr_stream stream;
+	struct xdr_buf buf;
+	struct page *scratch;
+	u64 stripe_unit;
+	u32 mirror_array_cnt;
+	__be32 *p;
+	int i, rc;
+
+	dprintk("--> %s\n", __func__);
+	scratch = alloc_page(gfp_flags);
+	if (!scratch)
+		return ERR_PTR(-ENOMEM);
+
+	xdr_init_decode_pages(&stream, &buf, lgr->layoutp->pages,
+			      lgr->layoutp->len);
+	xdr_set_scratch_buffer(&stream, page_address(scratch), PAGE_SIZE);
+
+	/* stripe unit and mirror_array_cnt */
+	rc = -EIO;
+	p = xdr_inline_decode(&stream, 8 + 4);
+	if (!p)
+		goto out_err_free;
+
+	p = xdr_decode_hyper(p, &stripe_unit);
+	mirror_array_cnt = be32_to_cpup(p++);
+	dprintk("%s: stripe_unit=%llu mirror_array_cnt=%u\n", __func__,
+		stripe_unit, mirror_array_cnt);
+
+	if (mirror_array_cnt > NFS4_FLEXFILE_LAYOUT_MAX_MIRROR_CNT ||
+	    mirror_array_cnt == 0)
+		goto out_err_free;
+
+	rc = -ENOMEM;
+	fls = kzalloc(struct_size(fls, mirror_array, mirror_array_cnt),
+			gfp_flags);
+	if (!fls)
+		goto out_err_free;
+
+	fls->mirror_array_cnt = mirror_array_cnt;
+	fls->stripe_unit = stripe_unit;
+
+	for (i = 0; i < fls->mirror_array_cnt; i++) {
+		struct nfs4_ff_layout_mirror *mirror;
+		struct cred *kcred;
+		const struct cred __rcu *cred;
+		kuid_t uid;
+		kgid_t gid;
+		u32 ds_count, fh_count, id;
+		int j;
+
+		rc = -EIO;
+		p = xdr_inline_decode(&stream, 4);
+		if (!p)
+			goto out_err_free;
+		ds_count = be32_to_cpup(p);
+
+		/* FIXME: allow for striping? */
+		if (ds_count != 1)
+			goto out_err_free;
+
+		fls->mirror_array[i] = ff_layout_alloc_mirror(gfp_flags);
+		if (fls->mirror_array[i] == NULL) {
+			rc = -ENOMEM;
+			goto out_err_free;
+		}
+
+		fls->mirror_array[i]->ds_count = ds_count;
+
+		/* deviceid */
+		rc = decode_deviceid(&stream, &fls->mirror_array[i]->devid);
+		if (rc)
+			goto out_err_free;
+
+		/* efficiency */
+		rc = -EIO;
+		p = xdr_inline_decode(&stream, 4);
+		if (!p)
+			goto out_err_free;
+		fls->mirror_array[i]->efficiency = be32_to_cpup(p);
+
+		/* stateid */
+		rc = decode_pnfs_stateid(&stream, &fls->mirror_array[i]->stateid);
+		if (rc)
+			goto out_err_free;
+
+		/* fh */
+		rc = -EIO;
+		p = xdr_inline_decode(&stream, 4);
+		if (!p)
+			goto out_err_free;
+		fh_count = be32_to_cpup(p);
+
+		fls->mirror_array[i]->fh_versions =
+			kcalloc(fh_count, sizeof(struct nfs_fh),
+				gfp_flags);
+		if (fls->mirror_array[i]->fh_versions == NULL) {
+			rc = -ENOMEM;
+			goto out_err_free;
+		}
+
+		for (j = 0; j < fh_count; j++) {
+			rc = decode_nfs_fh(&stream,
+					   &fls->mirror_array[i]->fh_versions[j]);
+			if (rc)
+				goto out_err_free;
+		}
+
+		fls->mirror_array[i]->fh_versions_cnt = fh_count;
+
+		/* user */
+		rc = decode_name(&stream, &id);
+		if (rc)
+			goto out_err_free;
+
+		uid = make_kuid(&init_user_ns, id);
+
+		/* group */
+		rc = decode_name(&stream, &id);
+		if (rc)
+			goto out_err_free;
+
+		gid = make_kgid(&init_user_ns, id);
+
+		if (gfp_flags & __GFP_FS)
+			kcred = prepare_kernel_cred(NULL);
+		else {
+			unsigned int nofs_flags = memalloc_nofs_save();
+			kcred = prepare_kernel_cred(NULL);
+			memalloc_nofs_restore(nofs_flags);
+		}
+		rc = -ENOMEM;
+		if (!kcred)
+			goto out_err_free;
+		kcred->fsuid = uid;
+		kcred->fsgid = gid;
+		cred = RCU_INITIALIZER(kcred);
+
+		if (lgr->range.iomode == IOMODE_READ)
+			rcu_assign_pointer(fls->mirror_array[i]->ro_cred, cred);
+		else
+			rcu_assign_pointer(fls->mirror_array[i]->rw_cred, cred);
+
+		mirror = ff_layout_add_mirror(lh, fls->mirror_array[i]);
+		if (mirror != fls->mirror_array[i]) {
+			/* swap cred ptrs so free_mirror will clean up old */
+			if (lgr->range.iomode == IOMODE_READ) {
+				cred = xchg(&mirror->ro_cred, cred);
+				rcu_assign_pointer(fls->mirror_array[i]->ro_cred, cred);
+			} else {
+				cred = xchg(&mirror->rw_cred, cred);
+				rcu_assign_pointer(fls->mirror_array[i]->rw_cred, cred);
+			}
+			ff_layout_free_mirror(fls->mirror_array[i]);
+			fls->mirror_array[i] = mirror;
+		}
+
+		dprintk("%s: iomode %s uid %u gid %u\n", __func__,
+			lgr->range.iomode == IOMODE_READ ? "READ" : "RW",
+			from_kuid(&init_user_ns, uid),
+			from_kgid(&init_user_ns, gid));
+	}
+
+	p = xdr_inline_decode(&stream, 4);
+	if (!p)
+		goto out_sort_mirrors;
+	fls->flags = be32_to_cpup(p);
+
+	p = xdr_inline_decode(&stream, 4);
+	if (!p)
+		goto out_sort_mirrors;
+	for (i=0; i < fls->mirror_array_cnt; i++)
+		fls->mirror_array[i]->report_interval = be32_to_cpup(p);
+
+out_sort_mirrors:
+	ff_layout_sort_mirrors(fls);
+	ret = &fls->generic_hdr;
+	dprintk("<-- %s (success)\n", __func__);
+out_free_page:
+	__free_page(scratch);
+	return ret;
+out_err_free:
+	_ff_layout_free_lseg(fls);
+	ret = ERR_PTR(rc);
+	dprintk("<-- %s (%d)\n", __func__, rc);
+	goto out_free_page;
+}
+
+static void
+ff_layout_free_lseg(struct pnfs_layout_segment *lseg)
+{
+	struct nfs4_ff_layout_segment *fls = FF_LAYOUT_LSEG(lseg);
+
+	dprintk("--> %s\n", __func__);
+
+	if (lseg->pls_range.iomode == IOMODE_RW) {
+		struct nfs4_flexfile_layout *ffl;
+		struct inode *inode;
+
+		ffl = FF_LAYOUT_FROM_HDR(lseg->pls_layout);
+		inode = ffl->generic_hdr.plh_inode;
+		spin_lock(&inode->i_lock);
+		pnfs_generic_ds_cinfo_release_lseg(&ffl->commit_info, lseg);
+		spin_unlock(&inode->i_lock);
+	}
+	_ff_layout_free_lseg(fls);
+}
+
+static void
+nfs4_ff_start_busy_timer(struct nfs4_ff_busy_timer *timer, ktime_t now)
+{
+	/* first IO request? */
+	if (atomic_inc_return(&timer->n_ops) == 1) {
+		timer->start_time = now;
+	}
+}
+
+static ktime_t
+nfs4_ff_end_busy_timer(struct nfs4_ff_busy_timer *timer, ktime_t now)
+{
+	ktime_t start;
+
+	if (atomic_dec_return(&timer->n_ops) < 0)
+		WARN_ON_ONCE(1);
+
+	start = timer->start_time;
+	timer->start_time = now;
+	return ktime_sub(now, start);
+}
+
+static bool
+nfs4_ff_layoutstat_start_io(struct nfs4_ff_layout_mirror *mirror,
+			    struct nfs4_ff_layoutstat *layoutstat,
+			    ktime_t now)
+{
+	s64 report_interval = FF_LAYOUTSTATS_REPORT_INTERVAL;
+	struct nfs4_flexfile_layout *ffl = FF_LAYOUT_FROM_HDR(mirror->layout);
+
+	nfs4_ff_start_busy_timer(&layoutstat->busy_timer, now);
+	if (!mirror->start_time)
+		mirror->start_time = now;
+	if (mirror->report_interval != 0)
+		report_interval = (s64)mirror->report_interval * 1000LL;
+	else if (layoutstats_timer != 0)
+		report_interval = (s64)layoutstats_timer * 1000LL;
+	if (ktime_to_ms(ktime_sub(now, ffl->last_report_time)) >=
+			report_interval) {
+		ffl->last_report_time = now;
+		return true;
+	}
+
+	return false;
+}
+
+static void
+nfs4_ff_layout_stat_io_update_requested(struct nfs4_ff_layoutstat *layoutstat,
+		__u64 requested)
+{
+	struct nfs4_ff_io_stat *iostat = &layoutstat->io_stat;
+
+	iostat->ops_requested++;
+	iostat->bytes_requested += requested;
+}
+
+static void
+nfs4_ff_layout_stat_io_update_completed(struct nfs4_ff_layoutstat *layoutstat,
+		__u64 requested,
+		__u64 completed,
+		ktime_t time_completed,
+		ktime_t time_started)
+{
+	struct nfs4_ff_io_stat *iostat = &layoutstat->io_stat;
+	ktime_t completion_time = ktime_sub(time_completed, time_started);
+	ktime_t timer;
+
+	iostat->ops_completed++;
+	iostat->bytes_completed += completed;
+	iostat->bytes_not_delivered += requested - completed;
+
+	timer = nfs4_ff_end_busy_timer(&layoutstat->busy_timer, time_completed);
+	iostat->total_busy_time =
+			ktime_add(iostat->total_busy_time, timer);
+	iostat->aggregate_completion_time =
+			ktime_add(iostat->aggregate_completion_time,
+					completion_time);
+}
+
+static void
+nfs4_ff_layout_stat_io_start_read(struct inode *inode,
+		struct nfs4_ff_layout_mirror *mirror,
+		__u64 requested, ktime_t now)
+{
+	bool report;
+
+	spin_lock(&mirror->lock);
+	report = nfs4_ff_layoutstat_start_io(mirror, &mirror->read_stat, now);
+	nfs4_ff_layout_stat_io_update_requested(&mirror->read_stat, requested);
+	set_bit(NFS4_FF_MIRROR_STAT_AVAIL, &mirror->flags);
+	spin_unlock(&mirror->lock);
+
+	if (report)
+		pnfs_report_layoutstat(inode, GFP_KERNEL);
+}
+
+static void
+nfs4_ff_layout_stat_io_end_read(struct rpc_task *task,
+		struct nfs4_ff_layout_mirror *mirror,
+		__u64 requested,
+		__u64 completed)
+{
+	spin_lock(&mirror->lock);
+	nfs4_ff_layout_stat_io_update_completed(&mirror->read_stat,
+			requested, completed,
+			ktime_get(), task->tk_start);
+	set_bit(NFS4_FF_MIRROR_STAT_AVAIL, &mirror->flags);
+	spin_unlock(&mirror->lock);
+}
+
+static void
+nfs4_ff_layout_stat_io_start_write(struct inode *inode,
+		struct nfs4_ff_layout_mirror *mirror,
+		__u64 requested, ktime_t now)
+{
+	bool report;
+
+	spin_lock(&mirror->lock);
+	report = nfs4_ff_layoutstat_start_io(mirror , &mirror->write_stat, now);
+	nfs4_ff_layout_stat_io_update_requested(&mirror->write_stat, requested);
+	set_bit(NFS4_FF_MIRROR_STAT_AVAIL, &mirror->flags);
+	spin_unlock(&mirror->lock);
+
+	if (report)
+		pnfs_report_layoutstat(inode, GFP_NOIO);
+}
+
+static void
+nfs4_ff_layout_stat_io_end_write(struct rpc_task *task,
+		struct nfs4_ff_layout_mirror *mirror,
+		__u64 requested,
+		__u64 completed,
+		enum nfs3_stable_how committed)
+{
+	if (committed == NFS_UNSTABLE)
+		requested = completed = 0;
+
+	spin_lock(&mirror->lock);
+	nfs4_ff_layout_stat_io_update_completed(&mirror->write_stat,
+			requested, completed, ktime_get(), task->tk_start);
+	set_bit(NFS4_FF_MIRROR_STAT_AVAIL, &mirror->flags);
+	spin_unlock(&mirror->lock);
+}
+
+static void
+ff_layout_mark_ds_unreachable(struct pnfs_layout_segment *lseg, u32 idx)
+{
+	struct nfs4_deviceid_node *devid = FF_LAYOUT_DEVID_NODE(lseg, idx);
+
+	if (devid)
+		nfs4_mark_deviceid_unavailable(devid);
+}
+
+static void
+ff_layout_mark_ds_reachable(struct pnfs_layout_segment *lseg, u32 idx)
+{
+	struct nfs4_deviceid_node *devid = FF_LAYOUT_DEVID_NODE(lseg, idx);
+
+	if (devid)
+		nfs4_mark_deviceid_available(devid);
+}
+
+static struct nfs4_pnfs_ds *
+ff_layout_choose_ds_for_read(struct pnfs_layout_segment *lseg,
+			     u32 start_idx, u32 *best_idx,
+			     bool check_device)
+{
+	struct nfs4_ff_layout_segment *fls = FF_LAYOUT_LSEG(lseg);
+	struct nfs4_ff_layout_mirror *mirror;
+	struct nfs4_pnfs_ds *ds;
+	bool fail_return = false;
+	u32 idx;
+
+	/* mirrors are initially sorted by efficiency */
+	for (idx = start_idx; idx < fls->mirror_array_cnt; idx++) {
+		if (idx+1 == fls->mirror_array_cnt)
+			fail_return = !check_device;
+
+		mirror = FF_LAYOUT_COMP(lseg, idx);
+		ds = nfs4_ff_layout_prepare_ds(lseg, mirror, fail_return);
+		if (!ds)
+			continue;
+
+		if (check_device &&
+		    nfs4_test_deviceid_unavailable(&mirror->mirror_ds->id_node))
+			continue;
+
+		*best_idx = idx;
+		return ds;
+	}
+
+	return NULL;
+}
+
+static struct nfs4_pnfs_ds *
+ff_layout_choose_any_ds_for_read(struct pnfs_layout_segment *lseg,
+				 u32 start_idx, u32 *best_idx)
+{
+	return ff_layout_choose_ds_for_read(lseg, start_idx, best_idx, false);
+}
+
+static struct nfs4_pnfs_ds *
+ff_layout_choose_valid_ds_for_read(struct pnfs_layout_segment *lseg,
+				   u32 start_idx, u32 *best_idx)
+{
+	return ff_layout_choose_ds_for_read(lseg, start_idx, best_idx, true);
+}
+
+static struct nfs4_pnfs_ds *
+ff_layout_choose_best_ds_for_read(struct pnfs_layout_segment *lseg,
+				  u32 start_idx, u32 *best_idx)
+{
+	struct nfs4_pnfs_ds *ds;
+
+	ds = ff_layout_choose_valid_ds_for_read(lseg, start_idx, best_idx);
+	if (ds)
+		return ds;
+	return ff_layout_choose_any_ds_for_read(lseg, start_idx, best_idx);
+}
+
+static struct nfs4_pnfs_ds *
+ff_layout_get_ds_for_read(struct nfs_pageio_descriptor *pgio,
+			  u32 *best_idx)
+{
+	struct pnfs_layout_segment *lseg = pgio->pg_lseg;
+	struct nfs4_pnfs_ds *ds;
+
+	ds = ff_layout_choose_best_ds_for_read(lseg, pgio->pg_mirror_idx,
+					       best_idx);
+	if (ds || !pgio->pg_mirror_idx)
+		return ds;
+	return ff_layout_choose_best_ds_for_read(lseg, 0, best_idx);
+}
+
+static void
+ff_layout_pg_get_read(struct nfs_pageio_descriptor *pgio,
+		      struct nfs_page *req,
+		      bool strict_iomode)
+{
+	pnfs_put_lseg(pgio->pg_lseg);
+	pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
+					   nfs_req_openctx(req),
+					   req_offset(req),
+					   req->wb_bytes,
+					   IOMODE_READ,
+					   strict_iomode,
+					   GFP_KERNEL);
+	if (IS_ERR(pgio->pg_lseg)) {
+		pgio->pg_error = PTR_ERR(pgio->pg_lseg);
+		pgio->pg_lseg = NULL;
+	}
+}
+
+static void
+ff_layout_pg_check_layout(struct nfs_pageio_descriptor *pgio,
+			  struct nfs_page *req)
+{
+	pnfs_generic_pg_check_layout(pgio);
+	pnfs_generic_pg_check_range(pgio, req);
+}
+
+static void
+ff_layout_pg_init_read(struct nfs_pageio_descriptor *pgio,
+			struct nfs_page *req)
+{
+	struct nfs_pgio_mirror *pgm;
+	struct nfs4_ff_layout_mirror *mirror;
+	struct nfs4_pnfs_ds *ds;
+	u32 ds_idx;
+
+retry:
+	ff_layout_pg_check_layout(pgio, req);
+	/* Use full layout for now */
+	if (!pgio->pg_lseg) {
+		ff_layout_pg_get_read(pgio, req, false);
+		if (!pgio->pg_lseg)
+			goto out_nolseg;
+	}
+	if (ff_layout_avoid_read_on_rw(pgio->pg_lseg)) {
+		ff_layout_pg_get_read(pgio, req, true);
+		if (!pgio->pg_lseg)
+			goto out_nolseg;
+	}
+
+	ds = ff_layout_get_ds_for_read(pgio, &ds_idx);
+	if (!ds) {
+		if (!ff_layout_no_fallback_to_mds(pgio->pg_lseg))
+			goto out_mds;
+		pnfs_generic_pg_cleanup(pgio);
+		/* Sleep for 1 second before retrying */
+		ssleep(1);
+		goto retry;
+	}
+
+	mirror = FF_LAYOUT_COMP(pgio->pg_lseg, ds_idx);
+	pgm = &pgio->pg_mirrors[0];
+	pgm->pg_bsize = mirror->mirror_ds->ds_versions[0].rsize;
+
+	pgio->pg_mirror_idx = ds_idx;
+
+	if (NFS_SERVER(pgio->pg_inode)->flags &
+			(NFS_MOUNT_SOFT|NFS_MOUNT_SOFTERR))
+		pgio->pg_maxretrans = io_maxretrans;
+	return;
+out_nolseg:
+	if (pgio->pg_error < 0)
+		return;
+out_mds:
+	trace_pnfs_mds_fallback_pg_init_read(pgio->pg_inode,
+			0, NFS4_MAX_UINT64, IOMODE_READ,
+			NFS_I(pgio->pg_inode)->layout,
+			pgio->pg_lseg);
+	pgio->pg_maxretrans = 0;
+	nfs_pageio_reset_read_mds(pgio);
+}
+
+static void
+ff_layout_pg_init_write(struct nfs_pageio_descriptor *pgio,
+			struct nfs_page *req)
+{
+	struct nfs4_ff_layout_mirror *mirror;
+	struct nfs_pgio_mirror *pgm;
+	struct nfs4_pnfs_ds *ds;
+	u32 i;
+
+retry:
+	ff_layout_pg_check_layout(pgio, req);
+	if (!pgio->pg_lseg) {
+		pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
+						   nfs_req_openctx(req),
+						   req_offset(req),
+						   req->wb_bytes,
+						   IOMODE_RW,
+						   false,
+						   GFP_NOFS);
+		if (IS_ERR(pgio->pg_lseg)) {
+			pgio->pg_error = PTR_ERR(pgio->pg_lseg);
+			pgio->pg_lseg = NULL;
+			return;
+		}
+	}
+	/* If no lseg, fall back to write through mds */
+	if (pgio->pg_lseg == NULL)
+		goto out_mds;
+
+	/* Use a direct mapping of ds_idx to pgio mirror_idx */
+	if (pgio->pg_mirror_count != FF_LAYOUT_MIRROR_COUNT(pgio->pg_lseg))
+		goto out_eagain;
+
+	for (i = 0; i < pgio->pg_mirror_count; i++) {
+		mirror = FF_LAYOUT_COMP(pgio->pg_lseg, i);
+		ds = nfs4_ff_layout_prepare_ds(pgio->pg_lseg, mirror, true);
+		if (!ds) {
+			if (!ff_layout_no_fallback_to_mds(pgio->pg_lseg))
+				goto out_mds;
+			pnfs_generic_pg_cleanup(pgio);
+			/* Sleep for 1 second before retrying */
+			ssleep(1);
+			goto retry;
+		}
+		pgm = &pgio->pg_mirrors[i];
+		pgm->pg_bsize = mirror->mirror_ds->ds_versions[0].wsize;
+	}
+
+	if (NFS_SERVER(pgio->pg_inode)->flags &
+			(NFS_MOUNT_SOFT|NFS_MOUNT_SOFTERR))
+		pgio->pg_maxretrans = io_maxretrans;
+	return;
+out_eagain:
+	pnfs_generic_pg_cleanup(pgio);
+	pgio->pg_error = -EAGAIN;
+	return;
+out_mds:
+	trace_pnfs_mds_fallback_pg_init_write(pgio->pg_inode,
+			0, NFS4_MAX_UINT64, IOMODE_RW,
+			NFS_I(pgio->pg_inode)->layout,
+			pgio->pg_lseg);
+	pgio->pg_maxretrans = 0;
+	nfs_pageio_reset_write_mds(pgio);
+	pgio->pg_error = -EAGAIN;
+}
+
+static unsigned int
+ff_layout_pg_get_mirror_count_write(struct nfs_pageio_descriptor *pgio,
+				    struct nfs_page *req)
+{
+	if (!pgio->pg_lseg) {
+		pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
+						   nfs_req_openctx(req),
+						   req_offset(req),
+						   req->wb_bytes,
+						   IOMODE_RW,
+						   false,
+						   GFP_NOFS);
+		if (IS_ERR(pgio->pg_lseg)) {
+			pgio->pg_error = PTR_ERR(pgio->pg_lseg);
+			pgio->pg_lseg = NULL;
+			goto out;
+		}
+	}
+	if (pgio->pg_lseg)
+		return FF_LAYOUT_MIRROR_COUNT(pgio->pg_lseg);
+
+	trace_pnfs_mds_fallback_pg_get_mirror_count(pgio->pg_inode,
+			0, NFS4_MAX_UINT64, IOMODE_RW,
+			NFS_I(pgio->pg_inode)->layout,
+			pgio->pg_lseg);
+	/* no lseg means that pnfs is not in use, so no mirroring here */
+	nfs_pageio_reset_write_mds(pgio);
+out:
+	return 1;
+}
+
+static u32
+ff_layout_pg_set_mirror_write(struct nfs_pageio_descriptor *desc, u32 idx)
+{
+	u32 old = desc->pg_mirror_idx;
+
+	desc->pg_mirror_idx = idx;
+	return old;
+}
+
+static struct nfs_pgio_mirror *
+ff_layout_pg_get_mirror_write(struct nfs_pageio_descriptor *desc, u32 idx)
+{
+	return &desc->pg_mirrors[idx];
+}
+
+static const struct nfs_pageio_ops ff_layout_pg_read_ops = {
+	.pg_init = ff_layout_pg_init_read,
+	.pg_test = pnfs_generic_pg_test,
+	.pg_doio = pnfs_generic_pg_readpages,
+	.pg_cleanup = pnfs_generic_pg_cleanup,
+};
+
+static const struct nfs_pageio_ops ff_layout_pg_write_ops = {
+	.pg_init = ff_layout_pg_init_write,
+	.pg_test = pnfs_generic_pg_test,
+	.pg_doio = pnfs_generic_pg_writepages,
+	.pg_get_mirror_count = ff_layout_pg_get_mirror_count_write,
+	.pg_cleanup = pnfs_generic_pg_cleanup,
+	.pg_get_mirror = ff_layout_pg_get_mirror_write,
+	.pg_set_mirror = ff_layout_pg_set_mirror_write,
+};
+
+static void ff_layout_reset_write(struct nfs_pgio_header *hdr, bool retry_pnfs)
+{
+	struct rpc_task *task = &hdr->task;
+
+	pnfs_layoutcommit_inode(hdr->inode, false);
+
+	if (retry_pnfs) {
+		dprintk("%s Reset task %5u for i/o through pNFS "
+			"(req %s/%llu, %u bytes @ offset %llu)\n", __func__,
+			hdr->task.tk_pid,
+			hdr->inode->i_sb->s_id,
+			(unsigned long long)NFS_FILEID(hdr->inode),
+			hdr->args.count,
+			(unsigned long long)hdr->args.offset);
+
+		hdr->completion_ops->reschedule_io(hdr);
+		return;
+	}
+
+	if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
+		dprintk("%s Reset task %5u for i/o through MDS "
+			"(req %s/%llu, %u bytes @ offset %llu)\n", __func__,
+			hdr->task.tk_pid,
+			hdr->inode->i_sb->s_id,
+			(unsigned long long)NFS_FILEID(hdr->inode),
+			hdr->args.count,
+			(unsigned long long)hdr->args.offset);
+
+		trace_pnfs_mds_fallback_write_done(hdr->inode,
+				hdr->args.offset, hdr->args.count,
+				IOMODE_RW, NFS_I(hdr->inode)->layout,
+				hdr->lseg);
+		task->tk_status = pnfs_write_done_resend_to_mds(hdr);
+	}
+}
+
+static void ff_layout_resend_pnfs_read(struct nfs_pgio_header *hdr)
+{
+	u32 idx = hdr->pgio_mirror_idx + 1;
+	u32 new_idx = 0;
+
+	if (ff_layout_choose_any_ds_for_read(hdr->lseg, idx, &new_idx))
+		ff_layout_send_layouterror(hdr->lseg);
+	else
+		pnfs_error_mark_layout_for_return(hdr->inode, hdr->lseg);
+	pnfs_read_resend_pnfs(hdr, new_idx);
+}
+
+static void ff_layout_reset_read(struct nfs_pgio_header *hdr)
+{
+	struct rpc_task *task = &hdr->task;
+
+	pnfs_layoutcommit_inode(hdr->inode, false);
+	pnfs_error_mark_layout_for_return(hdr->inode, hdr->lseg);
+
+	if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
+		dprintk("%s Reset task %5u for i/o through MDS "
+			"(req %s/%llu, %u bytes @ offset %llu)\n", __func__,
+			hdr->task.tk_pid,
+			hdr->inode->i_sb->s_id,
+			(unsigned long long)NFS_FILEID(hdr->inode),
+			hdr->args.count,
+			(unsigned long long)hdr->args.offset);
+
+		trace_pnfs_mds_fallback_read_done(hdr->inode,
+				hdr->args.offset, hdr->args.count,
+				IOMODE_READ, NFS_I(hdr->inode)->layout,
+				hdr->lseg);
+		task->tk_status = pnfs_read_done_resend_to_mds(hdr);
+	}
+}
+
+static int ff_layout_async_handle_error_v4(struct rpc_task *task,
+					   struct nfs4_state *state,
+					   struct nfs_client *clp,
+					   struct pnfs_layout_segment *lseg,
+					   u32 idx)
+{
+	struct pnfs_layout_hdr *lo = lseg->pls_layout;
+	struct inode *inode = lo->plh_inode;
+	struct nfs4_deviceid_node *devid = FF_LAYOUT_DEVID_NODE(lseg, idx);
+	struct nfs4_slot_table *tbl = &clp->cl_session->fc_slot_table;
+
+	switch (task->tk_status) {
+	case -NFS4ERR_BADSESSION:
+	case -NFS4ERR_BADSLOT:
+	case -NFS4ERR_BAD_HIGH_SLOT:
+	case -NFS4ERR_DEADSESSION:
+	case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
+	case -NFS4ERR_SEQ_FALSE_RETRY:
+	case -NFS4ERR_SEQ_MISORDERED:
+		dprintk("%s ERROR %d, Reset session. Exchangeid "
+			"flags 0x%x\n", __func__, task->tk_status,
+			clp->cl_exchange_flags);
+		nfs4_schedule_session_recovery(clp->cl_session, task->tk_status);
+		break;
+	case -NFS4ERR_DELAY:
+	case -NFS4ERR_GRACE:
+		rpc_delay(task, FF_LAYOUT_POLL_RETRY_MAX);
+		break;
+	case -NFS4ERR_RETRY_UNCACHED_REP:
+		break;
+	/* Invalidate Layout errors */
+	case -NFS4ERR_PNFS_NO_LAYOUT:
+	case -ESTALE:           /* mapped NFS4ERR_STALE */
+	case -EBADHANDLE:       /* mapped NFS4ERR_BADHANDLE */
+	case -EISDIR:           /* mapped NFS4ERR_ISDIR */
+	case -NFS4ERR_FHEXPIRED:
+	case -NFS4ERR_WRONG_TYPE:
+		dprintk("%s Invalid layout error %d\n", __func__,
+			task->tk_status);
+		/*
+		 * Destroy layout so new i/o will get a new layout.
+		 * Layout will not be destroyed until all current lseg
+		 * references are put. Mark layout as invalid to resend failed
+		 * i/o and all i/o waiting on the slot table to the MDS until
+		 * layout is destroyed and a new valid layout is obtained.
+		 */
+		pnfs_destroy_layout(NFS_I(inode));
+		rpc_wake_up(&tbl->slot_tbl_waitq);
+		goto reset;
+	/* RPC connection errors */
+	case -ECONNREFUSED:
+	case -EHOSTDOWN:
+	case -EHOSTUNREACH:
+	case -ENETUNREACH:
+	case -EIO:
+	case -ETIMEDOUT:
+	case -EPIPE:
+		dprintk("%s DS connection error %d\n", __func__,
+			task->tk_status);
+		nfs4_delete_deviceid(devid->ld, devid->nfs_client,
+				&devid->deviceid);
+		rpc_wake_up(&tbl->slot_tbl_waitq);
+		fallthrough;
+	default:
+		if (ff_layout_avoid_mds_available_ds(lseg))
+			return -NFS4ERR_RESET_TO_PNFS;
+reset:
+		dprintk("%s Retry through MDS. Error %d\n", __func__,
+			task->tk_status);
+		return -NFS4ERR_RESET_TO_MDS;
+	}
+	task->tk_status = 0;
+	return -EAGAIN;
+}
+
+/* Retry all errors through either pNFS or MDS except for -EJUKEBOX */
+static int ff_layout_async_handle_error_v3(struct rpc_task *task,
+					   struct pnfs_layout_segment *lseg,
+					   u32 idx)
+{
+	struct nfs4_deviceid_node *devid = FF_LAYOUT_DEVID_NODE(lseg, idx);
+
+	switch (task->tk_status) {
+	/* File access problems. Don't mark the device as unavailable */
+	case -EACCES:
+	case -ESTALE:
+	case -EISDIR:
+	case -EBADHANDLE:
+	case -ELOOP:
+	case -ENOSPC:
+		break;
+	case -EJUKEBOX:
+		nfs_inc_stats(lseg->pls_layout->plh_inode, NFSIOS_DELAY);
+		goto out_retry;
+	default:
+		dprintk("%s DS connection error %d\n", __func__,
+			task->tk_status);
+		nfs4_delete_deviceid(devid->ld, devid->nfs_client,
+				&devid->deviceid);
+	}
+	/* FIXME: Need to prevent infinite looping here. */
+	return -NFS4ERR_RESET_TO_PNFS;
+out_retry:
+	task->tk_status = 0;
+	rpc_restart_call_prepare(task);
+	rpc_delay(task, NFS_JUKEBOX_RETRY_TIME);
+	return -EAGAIN;
+}
+
+static int ff_layout_async_handle_error(struct rpc_task *task,
+					struct nfs4_state *state,
+					struct nfs_client *clp,
+					struct pnfs_layout_segment *lseg,
+					u32 idx)
+{
+	int vers = clp->cl_nfs_mod->rpc_vers->number;
+
+	if (task->tk_status >= 0) {
+		ff_layout_mark_ds_reachable(lseg, idx);
+		return 0;
+	}
+
+	/* Handle the case of an invalid layout segment */
+	if (!pnfs_is_valid_lseg(lseg))
+		return -NFS4ERR_RESET_TO_PNFS;
+
+	switch (vers) {
+	case 3:
+		return ff_layout_async_handle_error_v3(task, lseg, idx);
+	case 4:
+		return ff_layout_async_handle_error_v4(task, state, clp,
+						       lseg, idx);
+	default:
+		/* should never happen */
+		WARN_ON_ONCE(1);
+		return 0;
+	}
+}
+
+static void ff_layout_io_track_ds_error(struct pnfs_layout_segment *lseg,
+					u32 idx, u64 offset, u64 length,
+					u32 *op_status, int opnum, int error)
+{
+	struct nfs4_ff_layout_mirror *mirror;
+	u32 status = *op_status;
+	int err;
+
+	if (status == 0) {
+		switch (error) {
+		case -ETIMEDOUT:
+		case -EPFNOSUPPORT:
+		case -EPROTONOSUPPORT:
+		case -EOPNOTSUPP:
+		case -EINVAL:
+		case -ECONNREFUSED:
+		case -ECONNRESET:
+		case -EHOSTDOWN:
+		case -EHOSTUNREACH:
+		case -ENETUNREACH:
+		case -EADDRINUSE:
+		case -ENOBUFS:
+		case -EPIPE:
+		case -EPERM:
+			*op_status = status = NFS4ERR_NXIO;
+			break;
+		case -EACCES:
+			*op_status = status = NFS4ERR_ACCESS;
+			break;
+		default:
+			return;
+		}
+	}
+
+	mirror = FF_LAYOUT_COMP(lseg, idx);
+	err = ff_layout_track_ds_error(FF_LAYOUT_FROM_HDR(lseg->pls_layout),
+				       mirror, offset, length, status, opnum,
+				       GFP_NOIO);
+
+	switch (status) {
+	case NFS4ERR_DELAY:
+	case NFS4ERR_GRACE:
+		break;
+	case NFS4ERR_NXIO:
+		ff_layout_mark_ds_unreachable(lseg, idx);
+		/*
+		 * Don't return the layout if this is a read and we still
+		 * have layouts to try
+		 */
+		if (opnum == OP_READ)
+			break;
+		fallthrough;
+	default:
+		pnfs_error_mark_layout_for_return(lseg->pls_layout->plh_inode,
+						  lseg);
+	}
+
+	dprintk("%s: err %d op %d status %u\n", __func__, err, opnum, status);
+}
+
+/* NFS_PROTO call done callback routines */
+static int ff_layout_read_done_cb(struct rpc_task *task,
+				struct nfs_pgio_header *hdr)
+{
+	int err;
+
+	if (task->tk_status < 0) {
+		ff_layout_io_track_ds_error(hdr->lseg, hdr->pgio_mirror_idx,
+					    hdr->args.offset, hdr->args.count,
+					    &hdr->res.op_status, OP_READ,
+					    task->tk_status);
+		trace_ff_layout_read_error(hdr);
+	}
+
+	err = ff_layout_async_handle_error(task, hdr->args.context->state,
+					   hdr->ds_clp, hdr->lseg,
+					   hdr->pgio_mirror_idx);
+
+	trace_nfs4_pnfs_read(hdr, err);
+	clear_bit(NFS_IOHDR_RESEND_PNFS, &hdr->flags);
+	clear_bit(NFS_IOHDR_RESEND_MDS, &hdr->flags);
+	switch (err) {
+	case -NFS4ERR_RESET_TO_PNFS:
+		set_bit(NFS_IOHDR_RESEND_PNFS, &hdr->flags);
+		return task->tk_status;
+	case -NFS4ERR_RESET_TO_MDS:
+		set_bit(NFS_IOHDR_RESEND_MDS, &hdr->flags);
+		return task->tk_status;
+	case -EAGAIN:
+		goto out_eagain;
+	}
+
+	return 0;
+out_eagain:
+	rpc_restart_call_prepare(task);
+	return -EAGAIN;
+}
+
+static bool
+ff_layout_need_layoutcommit(struct pnfs_layout_segment *lseg)
+{
+	return !(FF_LAYOUT_LSEG(lseg)->flags & FF_FLAGS_NO_LAYOUTCOMMIT);
+}
+
+/*
+ * We reference the rpc_cred of the first WRITE that triggers the need for
+ * a LAYOUTCOMMIT, and use it to send the layoutcommit compound.
+ * rfc5661 is not clear about which credential should be used.
+ *
+ * Flexlayout client should treat DS replied FILE_SYNC as DATA_SYNC, so
+ * to follow http://www.rfc-editor.org/errata_search.php?rfc=5661&eid=2751
+ * we always send layoutcommit after DS writes.
+ */
+static void
+ff_layout_set_layoutcommit(struct inode *inode,
+		struct pnfs_layout_segment *lseg,
+		loff_t end_offset)
+{
+	if (!ff_layout_need_layoutcommit(lseg))
+		return;
+
+	pnfs_set_layoutcommit(inode, lseg, end_offset);
+	dprintk("%s inode %lu pls_end_pos %llu\n", __func__, inode->i_ino,
+		(unsigned long long) NFS_I(inode)->layout->plh_lwb);
+}
+
+static void ff_layout_read_record_layoutstats_start(struct rpc_task *task,
+		struct nfs_pgio_header *hdr)
+{
+	if (test_and_set_bit(NFS_IOHDR_STAT, &hdr->flags))
+		return;
+	nfs4_ff_layout_stat_io_start_read(hdr->inode,
+			FF_LAYOUT_COMP(hdr->lseg, hdr->pgio_mirror_idx),
+			hdr->args.count,
+			task->tk_start);
+}
+
+static void ff_layout_read_record_layoutstats_done(struct rpc_task *task,
+		struct nfs_pgio_header *hdr)
+{
+	if (!test_and_clear_bit(NFS_IOHDR_STAT, &hdr->flags))
+		return;
+	nfs4_ff_layout_stat_io_end_read(task,
+			FF_LAYOUT_COMP(hdr->lseg, hdr->pgio_mirror_idx),
+			hdr->args.count,
+			hdr->res.count);
+	set_bit(NFS_LSEG_LAYOUTRETURN, &hdr->lseg->pls_flags);
+}
+
+static int ff_layout_read_prepare_common(struct rpc_task *task,
+					 struct nfs_pgio_header *hdr)
+{
+	if (unlikely(test_bit(NFS_CONTEXT_BAD, &hdr->args.context->flags))) {
+		rpc_exit(task, -EIO);
+		return -EIO;
+	}
+
+	ff_layout_read_record_layoutstats_start(task, hdr);
+	return 0;
+}
+
+/*
+ * Call ops for the async read/write cases
+ * In the case of dense layouts, the offset needs to be reset to its
+ * original value.
+ */
+static void ff_layout_read_prepare_v3(struct rpc_task *task, void *data)
+{
+	struct nfs_pgio_header *hdr = data;
+
+	if (ff_layout_read_prepare_common(task, hdr))
+		return;
+
+	rpc_call_start(task);
+}
+
+static void ff_layout_read_prepare_v4(struct rpc_task *task, void *data)
+{
+	struct nfs_pgio_header *hdr = data;
+
+	if (nfs4_setup_sequence(hdr->ds_clp,
+				&hdr->args.seq_args,
+				&hdr->res.seq_res,
+				task))
+		return;
+
+	ff_layout_read_prepare_common(task, hdr);
+}
+
+static void ff_layout_read_call_done(struct rpc_task *task, void *data)
+{
+	struct nfs_pgio_header *hdr = data;
+
+	dprintk("--> %s task->tk_status %d\n", __func__, task->tk_status);
+
+	if (test_bit(NFS_IOHDR_REDO, &hdr->flags) &&
+	    task->tk_status == 0) {
+		nfs4_sequence_done(task, &hdr->res.seq_res);
+		return;
+	}
+
+	/* Note this may cause RPC to be resent */
+	hdr->mds_ops->rpc_call_done(task, hdr);
+}
+
+static void ff_layout_read_count_stats(struct rpc_task *task, void *data)
+{
+	struct nfs_pgio_header *hdr = data;
+
+	ff_layout_read_record_layoutstats_done(task, hdr);
+	rpc_count_iostats_metrics(task,
+	    &NFS_CLIENT(hdr->inode)->cl_metrics[NFSPROC4_CLNT_READ]);
+}
+
+static void ff_layout_read_release(void *data)
+{
+	struct nfs_pgio_header *hdr = data;
+
+	ff_layout_read_record_layoutstats_done(&hdr->task, hdr);
+	if (test_bit(NFS_IOHDR_RESEND_PNFS, &hdr->flags))
+		ff_layout_resend_pnfs_read(hdr);
+	else if (test_bit(NFS_IOHDR_RESEND_MDS, &hdr->flags))
+		ff_layout_reset_read(hdr);
+	pnfs_generic_rw_release(data);
+}
+
+
+static int ff_layout_write_done_cb(struct rpc_task *task,
+				struct nfs_pgio_header *hdr)
+{
+	loff_t end_offs = 0;
+	int err;
+
+	if (task->tk_status < 0) {
+		ff_layout_io_track_ds_error(hdr->lseg, hdr->pgio_mirror_idx,
+					    hdr->args.offset, hdr->args.count,
+					    &hdr->res.op_status, OP_WRITE,
+					    task->tk_status);
+		trace_ff_layout_write_error(hdr);
+	}
+
+	err = ff_layout_async_handle_error(task, hdr->args.context->state,
+					   hdr->ds_clp, hdr->lseg,
+					   hdr->pgio_mirror_idx);
+
+	trace_nfs4_pnfs_write(hdr, err);
+	clear_bit(NFS_IOHDR_RESEND_PNFS, &hdr->flags);
+	clear_bit(NFS_IOHDR_RESEND_MDS, &hdr->flags);
+	switch (err) {
+	case -NFS4ERR_RESET_TO_PNFS:
+		set_bit(NFS_IOHDR_RESEND_PNFS, &hdr->flags);
+		return task->tk_status;
+	case -NFS4ERR_RESET_TO_MDS:
+		set_bit(NFS_IOHDR_RESEND_MDS, &hdr->flags);
+		return task->tk_status;
+	case -EAGAIN:
+		return -EAGAIN;
+	}
+
+	if (hdr->res.verf->committed == NFS_FILE_SYNC ||
+	    hdr->res.verf->committed == NFS_DATA_SYNC)
+		end_offs = hdr->mds_offset + (loff_t)hdr->res.count;
+
+	/* Note: if the write is unstable, don't set end_offs until commit */
+	ff_layout_set_layoutcommit(hdr->inode, hdr->lseg, end_offs);
+
+	/* zero out fattr since we don't care DS attr at all */
+	hdr->fattr.valid = 0;
+	if (task->tk_status >= 0)
+		nfs_writeback_update_inode(hdr);
+
+	return 0;
+}
+
+static int ff_layout_commit_done_cb(struct rpc_task *task,
+				     struct nfs_commit_data *data)
+{
+	int err;
+
+	if (task->tk_status < 0) {
+		ff_layout_io_track_ds_error(data->lseg, data->ds_commit_index,
+					    data->args.offset, data->args.count,
+					    &data->res.op_status, OP_COMMIT,
+					    task->tk_status);
+		trace_ff_layout_commit_error(data);
+	}
+
+	err = ff_layout_async_handle_error(task, NULL, data->ds_clp,
+					   data->lseg, data->ds_commit_index);
+
+	trace_nfs4_pnfs_commit_ds(data, err);
+	switch (err) {
+	case -NFS4ERR_RESET_TO_PNFS:
+		pnfs_generic_prepare_to_resend_writes(data);
+		return -EAGAIN;
+	case -NFS4ERR_RESET_TO_MDS:
+		pnfs_generic_prepare_to_resend_writes(data);
+		return -EAGAIN;
+	case -EAGAIN:
+		rpc_restart_call_prepare(task);
+		return -EAGAIN;
+	}
+
+	ff_layout_set_layoutcommit(data->inode, data->lseg, data->lwb);
+
+	return 0;
+}
+
+static void ff_layout_write_record_layoutstats_start(struct rpc_task *task,
+		struct nfs_pgio_header *hdr)
+{
+	if (test_and_set_bit(NFS_IOHDR_STAT, &hdr->flags))
+		return;
+	nfs4_ff_layout_stat_io_start_write(hdr->inode,
+			FF_LAYOUT_COMP(hdr->lseg, hdr->pgio_mirror_idx),
+			hdr->args.count,
+			task->tk_start);
+}
+
+static void ff_layout_write_record_layoutstats_done(struct rpc_task *task,
+		struct nfs_pgio_header *hdr)
+{
+	if (!test_and_clear_bit(NFS_IOHDR_STAT, &hdr->flags))
+		return;
+	nfs4_ff_layout_stat_io_end_write(task,
+			FF_LAYOUT_COMP(hdr->lseg, hdr->pgio_mirror_idx),
+			hdr->args.count, hdr->res.count,
+			hdr->res.verf->committed);
+	set_bit(NFS_LSEG_LAYOUTRETURN, &hdr->lseg->pls_flags);
+}
+
+static int ff_layout_write_prepare_common(struct rpc_task *task,
+					  struct nfs_pgio_header *hdr)
+{
+	if (unlikely(test_bit(NFS_CONTEXT_BAD, &hdr->args.context->flags))) {
+		rpc_exit(task, -EIO);
+		return -EIO;
+	}
+
+	ff_layout_write_record_layoutstats_start(task, hdr);
+	return 0;
+}
+
+static void ff_layout_write_prepare_v3(struct rpc_task *task, void *data)
+{
+	struct nfs_pgio_header *hdr = data;
+
+	if (ff_layout_write_prepare_common(task, hdr))
+		return;
+
+	rpc_call_start(task);
+}
+
+static void ff_layout_write_prepare_v4(struct rpc_task *task, void *data)
+{
+	struct nfs_pgio_header *hdr = data;
+
+	if (nfs4_setup_sequence(hdr->ds_clp,
+				&hdr->args.seq_args,
+				&hdr->res.seq_res,
+				task))
+		return;
+
+	ff_layout_write_prepare_common(task, hdr);
+}
+
+static void ff_layout_write_call_done(struct rpc_task *task, void *data)
+{
+	struct nfs_pgio_header *hdr = data;
+
+	if (test_bit(NFS_IOHDR_REDO, &hdr->flags) &&
+	    task->tk_status == 0) {
+		nfs4_sequence_done(task, &hdr->res.seq_res);
+		return;
+	}
+
+	/* Note this may cause RPC to be resent */
+	hdr->mds_ops->rpc_call_done(task, hdr);
+}
+
+static void ff_layout_write_count_stats(struct rpc_task *task, void *data)
+{
+	struct nfs_pgio_header *hdr = data;
+
+	ff_layout_write_record_layoutstats_done(task, hdr);
+	rpc_count_iostats_metrics(task,
+	    &NFS_CLIENT(hdr->inode)->cl_metrics[NFSPROC4_CLNT_WRITE]);
+}
+
+static void ff_layout_write_release(void *data)
+{
+	struct nfs_pgio_header *hdr = data;
+
+	ff_layout_write_record_layoutstats_done(&hdr->task, hdr);
+	if (test_bit(NFS_IOHDR_RESEND_PNFS, &hdr->flags)) {
+		ff_layout_send_layouterror(hdr->lseg);
+		ff_layout_reset_write(hdr, true);
+	} else if (test_bit(NFS_IOHDR_RESEND_MDS, &hdr->flags))
+		ff_layout_reset_write(hdr, false);
+	pnfs_generic_rw_release(data);
+}
+
+static void ff_layout_commit_record_layoutstats_start(struct rpc_task *task,
+		struct nfs_commit_data *cdata)
+{
+	if (test_and_set_bit(NFS_IOHDR_STAT, &cdata->flags))
+		return;
+	nfs4_ff_layout_stat_io_start_write(cdata->inode,
+			FF_LAYOUT_COMP(cdata->lseg, cdata->ds_commit_index),
+			0, task->tk_start);
+}
+
+static void ff_layout_commit_record_layoutstats_done(struct rpc_task *task,
+		struct nfs_commit_data *cdata)
+{
+	struct nfs_page *req;
+	__u64 count = 0;
+
+	if (!test_and_clear_bit(NFS_IOHDR_STAT, &cdata->flags))
+		return;
+
+	if (task->tk_status == 0) {
+		list_for_each_entry(req, &cdata->pages, wb_list)
+			count += req->wb_bytes;
+	}
+	nfs4_ff_layout_stat_io_end_write(task,
+			FF_LAYOUT_COMP(cdata->lseg, cdata->ds_commit_index),
+			count, count, NFS_FILE_SYNC);
+	set_bit(NFS_LSEG_LAYOUTRETURN, &cdata->lseg->pls_flags);
+}
+
+static void ff_layout_commit_prepare_common(struct rpc_task *task,
+		struct nfs_commit_data *cdata)
+{
+	ff_layout_commit_record_layoutstats_start(task, cdata);
+}
+
+static void ff_layout_commit_prepare_v3(struct rpc_task *task, void *data)
+{
+	ff_layout_commit_prepare_common(task, data);
+	rpc_call_start(task);
+}
+
+static void ff_layout_commit_prepare_v4(struct rpc_task *task, void *data)
+{
+	struct nfs_commit_data *wdata = data;
+
+	if (nfs4_setup_sequence(wdata->ds_clp,
+				&wdata->args.seq_args,
+				&wdata->res.seq_res,
+				task))
+		return;
+	ff_layout_commit_prepare_common(task, data);
+}
+
+static void ff_layout_commit_done(struct rpc_task *task, void *data)
+{
+	pnfs_generic_write_commit_done(task, data);
+}
+
+static void ff_layout_commit_count_stats(struct rpc_task *task, void *data)
+{
+	struct nfs_commit_data *cdata = data;
+
+	ff_layout_commit_record_layoutstats_done(task, cdata);
+	rpc_count_iostats_metrics(task,
+	    &NFS_CLIENT(cdata->inode)->cl_metrics[NFSPROC4_CLNT_COMMIT]);
+}
+
+static void ff_layout_commit_release(void *data)
+{
+	struct nfs_commit_data *cdata = data;
+
+	ff_layout_commit_record_layoutstats_done(&cdata->task, cdata);
+	pnfs_generic_commit_release(data);
+}
+
+static const struct rpc_call_ops ff_layout_read_call_ops_v3 = {
+	.rpc_call_prepare = ff_layout_read_prepare_v3,
+	.rpc_call_done = ff_layout_read_call_done,
+	.rpc_count_stats = ff_layout_read_count_stats,
+	.rpc_release = ff_layout_read_release,
+};
+
+static const struct rpc_call_ops ff_layout_read_call_ops_v4 = {
+	.rpc_call_prepare = ff_layout_read_prepare_v4,
+	.rpc_call_done = ff_layout_read_call_done,
+	.rpc_count_stats = ff_layout_read_count_stats,
+	.rpc_release = ff_layout_read_release,
+};
+
+static const struct rpc_call_ops ff_layout_write_call_ops_v3 = {
+	.rpc_call_prepare = ff_layout_write_prepare_v3,
+	.rpc_call_done = ff_layout_write_call_done,
+	.rpc_count_stats = ff_layout_write_count_stats,
+	.rpc_release = ff_layout_write_release,
+};
+
+static const struct rpc_call_ops ff_layout_write_call_ops_v4 = {
+	.rpc_call_prepare = ff_layout_write_prepare_v4,
+	.rpc_call_done = ff_layout_write_call_done,
+	.rpc_count_stats = ff_layout_write_count_stats,
+	.rpc_release = ff_layout_write_release,
+};
+
+static const struct rpc_call_ops ff_layout_commit_call_ops_v3 = {
+	.rpc_call_prepare = ff_layout_commit_prepare_v3,
+	.rpc_call_done = ff_layout_commit_done,
+	.rpc_count_stats = ff_layout_commit_count_stats,
+	.rpc_release = ff_layout_commit_release,
+};
+
+static const struct rpc_call_ops ff_layout_commit_call_ops_v4 = {
+	.rpc_call_prepare = ff_layout_commit_prepare_v4,
+	.rpc_call_done = ff_layout_commit_done,
+	.rpc_count_stats = ff_layout_commit_count_stats,
+	.rpc_release = ff_layout_commit_release,
+};
+
+static enum pnfs_try_status
+ff_layout_read_pagelist(struct nfs_pgio_header *hdr)
+{
+	struct pnfs_layout_segment *lseg = hdr->lseg;
+	struct nfs4_pnfs_ds *ds;
+	struct rpc_clnt *ds_clnt;
+	struct nfs4_ff_layout_mirror *mirror;
+	const struct cred *ds_cred;
+	loff_t offset = hdr->args.offset;
+	u32 idx = hdr->pgio_mirror_idx;
+	int vers;
+	struct nfs_fh *fh;
+
+	dprintk("--> %s ino %lu pgbase %u req %zu@%llu\n",
+		__func__, hdr->inode->i_ino,
+		hdr->args.pgbase, (size_t)hdr->args.count, offset);
+
+	mirror = FF_LAYOUT_COMP(lseg, idx);
+	ds = nfs4_ff_layout_prepare_ds(lseg, mirror, false);
+	if (!ds)
+		goto out_failed;
+
+	ds_clnt = nfs4_ff_find_or_create_ds_client(mirror, ds->ds_clp,
+						   hdr->inode);
+	if (IS_ERR(ds_clnt))
+		goto out_failed;
+
+	ds_cred = ff_layout_get_ds_cred(mirror, &lseg->pls_range, hdr->cred);
+	if (!ds_cred)
+		goto out_failed;
+
+	vers = nfs4_ff_layout_ds_version(mirror);
+
+	dprintk("%s USE DS: %s cl_count %d vers %d\n", __func__,
+		ds->ds_remotestr, refcount_read(&ds->ds_clp->cl_count), vers);
+
+	hdr->pgio_done_cb = ff_layout_read_done_cb;
+	refcount_inc(&ds->ds_clp->cl_count);
+	hdr->ds_clp = ds->ds_clp;
+	fh = nfs4_ff_layout_select_ds_fh(mirror);
+	if (fh)
+		hdr->args.fh = fh;
+
+	nfs4_ff_layout_select_ds_stateid(mirror, &hdr->args.stateid);
+
+	/*
+	 * Note that if we ever decide to split across DSes,
+	 * then we may need to handle dense-like offsets.
+	 */
+	hdr->args.offset = offset;
+	hdr->mds_offset = offset;
+
+	/* Perform an asynchronous read to ds */
+	nfs_initiate_pgio(ds_clnt, hdr, ds_cred, ds->ds_clp->rpc_ops,
+			  vers == 3 ? &ff_layout_read_call_ops_v3 :
+				      &ff_layout_read_call_ops_v4,
+			  0, RPC_TASK_SOFTCONN);
+	put_cred(ds_cred);
+	return PNFS_ATTEMPTED;
+
+out_failed:
+	if (ff_layout_avoid_mds_available_ds(lseg))
+		return PNFS_TRY_AGAIN;
+	trace_pnfs_mds_fallback_read_pagelist(hdr->inode,
+			hdr->args.offset, hdr->args.count,
+			IOMODE_READ, NFS_I(hdr->inode)->layout, lseg);
+	return PNFS_NOT_ATTEMPTED;
+}
+
+/* Perform async writes. */
+static enum pnfs_try_status
+ff_layout_write_pagelist(struct nfs_pgio_header *hdr, int sync)
+{
+	struct pnfs_layout_segment *lseg = hdr->lseg;
+	struct nfs4_pnfs_ds *ds;
+	struct rpc_clnt *ds_clnt;
+	struct nfs4_ff_layout_mirror *mirror;
+	const struct cred *ds_cred;
+	loff_t offset = hdr->args.offset;
+	int vers;
+	struct nfs_fh *fh;
+	u32 idx = hdr->pgio_mirror_idx;
+
+	mirror = FF_LAYOUT_COMP(lseg, idx);
+	ds = nfs4_ff_layout_prepare_ds(lseg, mirror, true);
+	if (!ds)
+		goto out_failed;
+
+	ds_clnt = nfs4_ff_find_or_create_ds_client(mirror, ds->ds_clp,
+						   hdr->inode);
+	if (IS_ERR(ds_clnt))
+		goto out_failed;
+
+	ds_cred = ff_layout_get_ds_cred(mirror, &lseg->pls_range, hdr->cred);
+	if (!ds_cred)
+		goto out_failed;
+
+	vers = nfs4_ff_layout_ds_version(mirror);
+
+	dprintk("%s ino %lu sync %d req %zu@%llu DS: %s cl_count %d vers %d\n",
+		__func__, hdr->inode->i_ino, sync, (size_t) hdr->args.count,
+		offset, ds->ds_remotestr, refcount_read(&ds->ds_clp->cl_count),
+		vers);
+
+	hdr->pgio_done_cb = ff_layout_write_done_cb;
+	refcount_inc(&ds->ds_clp->cl_count);
+	hdr->ds_clp = ds->ds_clp;
+	hdr->ds_commit_idx = idx;
+	fh = nfs4_ff_layout_select_ds_fh(mirror);
+	if (fh)
+		hdr->args.fh = fh;
+
+	nfs4_ff_layout_select_ds_stateid(mirror, &hdr->args.stateid);
+
+	/*
+	 * Note that if we ever decide to split across DSes,
+	 * then we may need to handle dense-like offsets.
+	 */
+	hdr->args.offset = offset;
+
+	/* Perform an asynchronous write */
+	nfs_initiate_pgio(ds_clnt, hdr, ds_cred, ds->ds_clp->rpc_ops,
+			  vers == 3 ? &ff_layout_write_call_ops_v3 :
+				      &ff_layout_write_call_ops_v4,
+			  sync, RPC_TASK_SOFTCONN);
+	put_cred(ds_cred);
+	return PNFS_ATTEMPTED;
+
+out_failed:
+	if (ff_layout_avoid_mds_available_ds(lseg))
+		return PNFS_TRY_AGAIN;
+	trace_pnfs_mds_fallback_write_pagelist(hdr->inode,
+			hdr->args.offset, hdr->args.count,
+			IOMODE_RW, NFS_I(hdr->inode)->layout, lseg);
+	return PNFS_NOT_ATTEMPTED;
+}
+
+static u32 calc_ds_index_from_commit(struct pnfs_layout_segment *lseg, u32 i)
+{
+	return i;
+}
+
+static struct nfs_fh *
+select_ds_fh_from_commit(struct pnfs_layout_segment *lseg, u32 i)
+{
+	struct nfs4_ff_layout_segment *flseg = FF_LAYOUT_LSEG(lseg);
+
+	/* FIXME: Assume that there is only one NFS version available
+	 * for the DS.
+	 */
+	return &flseg->mirror_array[i]->fh_versions[0];
+}
+
+static int ff_layout_initiate_commit(struct nfs_commit_data *data, int how)
+{
+	struct pnfs_layout_segment *lseg = data->lseg;
+	struct nfs4_pnfs_ds *ds;
+	struct rpc_clnt *ds_clnt;
+	struct nfs4_ff_layout_mirror *mirror;
+	const struct cred *ds_cred;
+	u32 idx;
+	int vers, ret;
+	struct nfs_fh *fh;
+
+	if (!lseg || !(pnfs_is_valid_lseg(lseg) ||
+	    test_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags)))
+		goto out_err;
+
+	idx = calc_ds_index_from_commit(lseg, data->ds_commit_index);
+	mirror = FF_LAYOUT_COMP(lseg, idx);
+	ds = nfs4_ff_layout_prepare_ds(lseg, mirror, true);
+	if (!ds)
+		goto out_err;
+
+	ds_clnt = nfs4_ff_find_or_create_ds_client(mirror, ds->ds_clp,
+						   data->inode);
+	if (IS_ERR(ds_clnt))
+		goto out_err;
+
+	ds_cred = ff_layout_get_ds_cred(mirror, &lseg->pls_range, data->cred);
+	if (!ds_cred)
+		goto out_err;
+
+	vers = nfs4_ff_layout_ds_version(mirror);
+
+	dprintk("%s ino %lu, how %d cl_count %d vers %d\n", __func__,
+		data->inode->i_ino, how, refcount_read(&ds->ds_clp->cl_count),
+		vers);
+	data->commit_done_cb = ff_layout_commit_done_cb;
+	data->cred = ds_cred;
+	refcount_inc(&ds->ds_clp->cl_count);
+	data->ds_clp = ds->ds_clp;
+	fh = select_ds_fh_from_commit(lseg, data->ds_commit_index);
+	if (fh)
+		data->args.fh = fh;
+
+	ret = nfs_initiate_commit(ds_clnt, data, ds->ds_clp->rpc_ops,
+				   vers == 3 ? &ff_layout_commit_call_ops_v3 :
+					       &ff_layout_commit_call_ops_v4,
+				   how, RPC_TASK_SOFTCONN);
+	put_cred(ds_cred);
+	return ret;
+out_err:
+	pnfs_generic_prepare_to_resend_writes(data);
+	pnfs_generic_commit_release(data);
+	return -EAGAIN;
+}
+
+static int
+ff_layout_commit_pagelist(struct inode *inode, struct list_head *mds_pages,
+			   int how, struct nfs_commit_info *cinfo)
+{
+	return pnfs_generic_commit_pagelist(inode, mds_pages, how, cinfo,
+					    ff_layout_initiate_commit);
+}
+
+static struct pnfs_ds_commit_info *
+ff_layout_get_ds_info(struct inode *inode)
+{
+	struct pnfs_layout_hdr *layout = NFS_I(inode)->layout;
+
+	if (layout == NULL)
+		return NULL;
+
+	return &FF_LAYOUT_FROM_HDR(layout)->commit_info;
+}
+
+static void
+ff_layout_setup_ds_info(struct pnfs_ds_commit_info *fl_cinfo,
+		struct pnfs_layout_segment *lseg)
+{
+	struct nfs4_ff_layout_segment *flseg = FF_LAYOUT_LSEG(lseg);
+	struct inode *inode = lseg->pls_layout->plh_inode;
+	struct pnfs_commit_array *array, *new;
+
+	new = pnfs_alloc_commit_array(flseg->mirror_array_cnt, GFP_NOIO);
+	if (new) {
+		spin_lock(&inode->i_lock);
+		array = pnfs_add_commit_array(fl_cinfo, new, lseg);
+		spin_unlock(&inode->i_lock);
+		if (array != new)
+			pnfs_free_commit_array(new);
+	}
+}
+
+static void
+ff_layout_release_ds_info(struct pnfs_ds_commit_info *fl_cinfo,
+		struct inode *inode)
+{
+	spin_lock(&inode->i_lock);
+	pnfs_generic_ds_cinfo_destroy(fl_cinfo);
+	spin_unlock(&inode->i_lock);
+}
+
+static void
+ff_layout_free_deviceid_node(struct nfs4_deviceid_node *d)
+{
+	nfs4_ff_layout_free_deviceid(container_of(d, struct nfs4_ff_layout_ds,
+						  id_node));
+}
+
+static int ff_layout_encode_ioerr(struct xdr_stream *xdr,
+				  const struct nfs4_layoutreturn_args *args,
+				  const struct nfs4_flexfile_layoutreturn_args *ff_args)
+{
+	__be32 *start;
+
+	start = xdr_reserve_space(xdr, 4);
+	if (unlikely(!start))
+		return -E2BIG;
+
+	*start = cpu_to_be32(ff_args->num_errors);
+	/* This assume we always return _ALL_ layouts */
+	return ff_layout_encode_ds_ioerr(xdr, &ff_args->errors);
+}
+
+static void
+encode_opaque_fixed(struct xdr_stream *xdr, const void *buf, size_t len)
+{
+	WARN_ON_ONCE(xdr_stream_encode_opaque_fixed(xdr, buf, len) < 0);
+}
+
+static void
+ff_layout_encode_ff_iostat_head(struct xdr_stream *xdr,
+			    const nfs4_stateid *stateid,
+			    const struct nfs42_layoutstat_devinfo *devinfo)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 8 + 8);
+	p = xdr_encode_hyper(p, devinfo->offset);
+	p = xdr_encode_hyper(p, devinfo->length);
+	encode_opaque_fixed(xdr, stateid->data, NFS4_STATEID_SIZE);
+	p = xdr_reserve_space(xdr, 4*8);
+	p = xdr_encode_hyper(p, devinfo->read_count);
+	p = xdr_encode_hyper(p, devinfo->read_bytes);
+	p = xdr_encode_hyper(p, devinfo->write_count);
+	p = xdr_encode_hyper(p, devinfo->write_bytes);
+	encode_opaque_fixed(xdr, devinfo->dev_id.data, NFS4_DEVICEID4_SIZE);
+}
+
+static void
+ff_layout_encode_ff_iostat(struct xdr_stream *xdr,
+			    const nfs4_stateid *stateid,
+			    const struct nfs42_layoutstat_devinfo *devinfo)
+{
+	ff_layout_encode_ff_iostat_head(xdr, stateid, devinfo);
+	ff_layout_encode_ff_layoutupdate(xdr, devinfo,
+			devinfo->ld_private.data);
+}
+
+/* report nothing for now */
+static void ff_layout_encode_iostats_array(struct xdr_stream *xdr,
+		const struct nfs4_layoutreturn_args *args,
+		struct nfs4_flexfile_layoutreturn_args *ff_args)
+{
+	__be32 *p;
+	int i;
+
+	p = xdr_reserve_space(xdr, 4);
+	*p = cpu_to_be32(ff_args->num_dev);
+	for (i = 0; i < ff_args->num_dev; i++)
+		ff_layout_encode_ff_iostat(xdr,
+				&args->layout->plh_stateid,
+				&ff_args->devinfo[i]);
+}
+
+static void
+ff_layout_free_iostats_array(struct nfs42_layoutstat_devinfo *devinfo,
+		unsigned int num_entries)
+{
+	unsigned int i;
+
+	for (i = 0; i < num_entries; i++) {
+		if (!devinfo[i].ld_private.ops)
+			continue;
+		if (!devinfo[i].ld_private.ops->free)
+			continue;
+		devinfo[i].ld_private.ops->free(&devinfo[i].ld_private);
+	}
+}
+
+static struct nfs4_deviceid_node *
+ff_layout_alloc_deviceid_node(struct nfs_server *server,
+			      struct pnfs_device *pdev, gfp_t gfp_flags)
+{
+	struct nfs4_ff_layout_ds *dsaddr;
+
+	dsaddr = nfs4_ff_alloc_deviceid_node(server, pdev, gfp_flags);
+	if (!dsaddr)
+		return NULL;
+	return &dsaddr->id_node;
+}
+
+static void
+ff_layout_encode_layoutreturn(struct xdr_stream *xdr,
+		const void *voidargs,
+		const struct nfs4_xdr_opaque_data *ff_opaque)
+{
+	const struct nfs4_layoutreturn_args *args = voidargs;
+	struct nfs4_flexfile_layoutreturn_args *ff_args = ff_opaque->data;
+	struct xdr_buf tmp_buf = {
+		.head = {
+			[0] = {
+				.iov_base = page_address(ff_args->pages[0]),
+			},
+		},
+		.buflen = PAGE_SIZE,
+	};
+	struct xdr_stream tmp_xdr;
+	__be32 *start;
+
+	dprintk("%s: Begin\n", __func__);
+
+	xdr_init_encode(&tmp_xdr, &tmp_buf, NULL, NULL);
+
+	ff_layout_encode_ioerr(&tmp_xdr, args, ff_args);
+	ff_layout_encode_iostats_array(&tmp_xdr, args, ff_args);
+
+	start = xdr_reserve_space(xdr, 4);
+	*start = cpu_to_be32(tmp_buf.len);
+	xdr_write_pages(xdr, ff_args->pages, 0, tmp_buf.len);
+
+	dprintk("%s: Return\n", __func__);
+}
+
+static void
+ff_layout_free_layoutreturn(struct nfs4_xdr_opaque_data *args)
+{
+	struct nfs4_flexfile_layoutreturn_args *ff_args;
+
+	if (!args->data)
+		return;
+	ff_args = args->data;
+	args->data = NULL;
+
+	ff_layout_free_ds_ioerr(&ff_args->errors);
+	ff_layout_free_iostats_array(ff_args->devinfo, ff_args->num_dev);
+
+	put_page(ff_args->pages[0]);
+	kfree(ff_args);
+}
+
+static const struct nfs4_xdr_opaque_ops layoutreturn_ops = {
+	.encode = ff_layout_encode_layoutreturn,
+	.free = ff_layout_free_layoutreturn,
+};
+
+static int
+ff_layout_prepare_layoutreturn(struct nfs4_layoutreturn_args *args)
+{
+	struct nfs4_flexfile_layoutreturn_args *ff_args;
+	struct nfs4_flexfile_layout *ff_layout = FF_LAYOUT_FROM_HDR(args->layout);
+
+	ff_args = kmalloc(sizeof(*ff_args), GFP_KERNEL);
+	if (!ff_args)
+		goto out_nomem;
+	ff_args->pages[0] = alloc_page(GFP_KERNEL);
+	if (!ff_args->pages[0])
+		goto out_nomem_free;
+
+	INIT_LIST_HEAD(&ff_args->errors);
+	ff_args->num_errors = ff_layout_fetch_ds_ioerr(args->layout,
+			&args->range, &ff_args->errors,
+			FF_LAYOUTRETURN_MAXERR);
+
+	spin_lock(&args->inode->i_lock);
+	ff_args->num_dev = ff_layout_mirror_prepare_stats(&ff_layout->generic_hdr,
+			&ff_args->devinfo[0], ARRAY_SIZE(ff_args->devinfo));
+	spin_unlock(&args->inode->i_lock);
+
+	args->ld_private->ops = &layoutreturn_ops;
+	args->ld_private->data = ff_args;
+	return 0;
+out_nomem_free:
+	kfree(ff_args);
+out_nomem:
+	return -ENOMEM;
+}
+
+#ifdef CONFIG_NFS_V4_2
+void
+ff_layout_send_layouterror(struct pnfs_layout_segment *lseg)
+{
+	struct pnfs_layout_hdr *lo = lseg->pls_layout;
+	struct nfs42_layout_error *errors;
+	LIST_HEAD(head);
+
+	if (!nfs_server_capable(lo->plh_inode, NFS_CAP_LAYOUTERROR))
+		return;
+	ff_layout_fetch_ds_ioerr(lo, &lseg->pls_range, &head, -1);
+	if (list_empty(&head))
+		return;
+
+	errors = kmalloc_array(NFS42_LAYOUTERROR_MAX,
+			sizeof(*errors), GFP_NOFS);
+	if (errors != NULL) {
+		const struct nfs4_ff_layout_ds_err *pos;
+		size_t n = 0;
+
+		list_for_each_entry(pos, &head, list) {
+			errors[n].offset = pos->offset;
+			errors[n].length = pos->length;
+			nfs4_stateid_copy(&errors[n].stateid, &pos->stateid);
+			errors[n].errors[0].dev_id = pos->deviceid;
+			errors[n].errors[0].status = pos->status;
+			errors[n].errors[0].opnum = pos->opnum;
+			n++;
+			if (!list_is_last(&pos->list, &head) &&
+			    n < NFS42_LAYOUTERROR_MAX)
+				continue;
+			if (nfs42_proc_layouterror(lseg, errors, n) < 0)
+				break;
+			n = 0;
+		}
+		kfree(errors);
+	}
+	ff_layout_free_ds_ioerr(&head);
+}
+#else
+void
+ff_layout_send_layouterror(struct pnfs_layout_segment *lseg)
+{
+}
+#endif
+
+static int
+ff_layout_ntop4(const struct sockaddr *sap, char *buf, const size_t buflen)
+{
+	const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
+
+	return snprintf(buf, buflen, "%pI4", &sin->sin_addr);
+}
+
+static size_t
+ff_layout_ntop6_noscopeid(const struct sockaddr *sap, char *buf,
+			  const int buflen)
+{
+	const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
+	const struct in6_addr *addr = &sin6->sin6_addr;
+
+	/*
+	 * RFC 4291, Section 2.2.2
+	 *
+	 * Shorthanded ANY address
+	 */
+	if (ipv6_addr_any(addr))
+		return snprintf(buf, buflen, "::");
+
+	/*
+	 * RFC 4291, Section 2.2.2
+	 *
+	 * Shorthanded loopback address
+	 */
+	if (ipv6_addr_loopback(addr))
+		return snprintf(buf, buflen, "::1");
+
+	/*
+	 * RFC 4291, Section 2.2.3
+	 *
+	 * Special presentation address format for mapped v4
+	 * addresses.
+	 */
+	if (ipv6_addr_v4mapped(addr))
+		return snprintf(buf, buflen, "::ffff:%pI4",
+					&addr->s6_addr32[3]);
+
+	/*
+	 * RFC 4291, Section 2.2.1
+	 */
+	return snprintf(buf, buflen, "%pI6c", addr);
+}
+
+/* Derived from rpc_sockaddr2uaddr */
+static void
+ff_layout_encode_netaddr(struct xdr_stream *xdr, struct nfs4_pnfs_ds_addr *da)
+{
+	struct sockaddr *sap = (struct sockaddr *)&da->da_addr;
+	char portbuf[RPCBIND_MAXUADDRPLEN];
+	char addrbuf[RPCBIND_MAXUADDRLEN];
+	char *netid;
+	unsigned short port;
+	int len, netid_len;
+	__be32 *p;
+
+	switch (sap->sa_family) {
+	case AF_INET:
+		if (ff_layout_ntop4(sap, addrbuf, sizeof(addrbuf)) == 0)
+			return;
+		port = ntohs(((struct sockaddr_in *)sap)->sin_port);
+		netid = "tcp";
+		netid_len = 3;
+		break;
+	case AF_INET6:
+		if (ff_layout_ntop6_noscopeid(sap, addrbuf, sizeof(addrbuf)) == 0)
+			return;
+		port = ntohs(((struct sockaddr_in6 *)sap)->sin6_port);
+		netid = "tcp6";
+		netid_len = 4;
+		break;
+	default:
+		/* we only support tcp and tcp6 */
+		WARN_ON_ONCE(1);
+		return;
+	}
+
+	snprintf(portbuf, sizeof(portbuf), ".%u.%u", port >> 8, port & 0xff);
+	len = strlcat(addrbuf, portbuf, sizeof(addrbuf));
+
+	p = xdr_reserve_space(xdr, 4 + netid_len);
+	xdr_encode_opaque(p, netid, netid_len);
+
+	p = xdr_reserve_space(xdr, 4 + len);
+	xdr_encode_opaque(p, addrbuf, len);
+}
+
+static void
+ff_layout_encode_nfstime(struct xdr_stream *xdr,
+			 ktime_t t)
+{
+	struct timespec64 ts;
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 12);
+	ts = ktime_to_timespec64(t);
+	p = xdr_encode_hyper(p, ts.tv_sec);
+	*p++ = cpu_to_be32(ts.tv_nsec);
+}
+
+static void
+ff_layout_encode_io_latency(struct xdr_stream *xdr,
+			    struct nfs4_ff_io_stat *stat)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 5 * 8);
+	p = xdr_encode_hyper(p, stat->ops_requested);
+	p = xdr_encode_hyper(p, stat->bytes_requested);
+	p = xdr_encode_hyper(p, stat->ops_completed);
+	p = xdr_encode_hyper(p, stat->bytes_completed);
+	p = xdr_encode_hyper(p, stat->bytes_not_delivered);
+	ff_layout_encode_nfstime(xdr, stat->total_busy_time);
+	ff_layout_encode_nfstime(xdr, stat->aggregate_completion_time);
+}
+
+static void
+ff_layout_encode_ff_layoutupdate(struct xdr_stream *xdr,
+			      const struct nfs42_layoutstat_devinfo *devinfo,
+			      struct nfs4_ff_layout_mirror *mirror)
+{
+	struct nfs4_pnfs_ds_addr *da;
+	struct nfs4_pnfs_ds *ds = mirror->mirror_ds->ds;
+	struct nfs_fh *fh = &mirror->fh_versions[0];
+	__be32 *p;
+
+	da = list_first_entry(&ds->ds_addrs, struct nfs4_pnfs_ds_addr, da_node);
+	dprintk("%s: DS %s: encoding address %s\n",
+		__func__, ds->ds_remotestr, da->da_remotestr);
+	/* netaddr4 */
+	ff_layout_encode_netaddr(xdr, da);
+	/* nfs_fh4 */
+	p = xdr_reserve_space(xdr, 4 + fh->size);
+	xdr_encode_opaque(p, fh->data, fh->size);
+	/* ff_io_latency4 read */
+	spin_lock(&mirror->lock);
+	ff_layout_encode_io_latency(xdr, &mirror->read_stat.io_stat);
+	/* ff_io_latency4 write */
+	ff_layout_encode_io_latency(xdr, &mirror->write_stat.io_stat);
+	spin_unlock(&mirror->lock);
+	/* nfstime4 */
+	ff_layout_encode_nfstime(xdr, ktime_sub(ktime_get(), mirror->start_time));
+	/* bool */
+	p = xdr_reserve_space(xdr, 4);
+	*p = cpu_to_be32(false);
+}
+
+static void
+ff_layout_encode_layoutstats(struct xdr_stream *xdr, const void *args,
+			     const struct nfs4_xdr_opaque_data *opaque)
+{
+	struct nfs42_layoutstat_devinfo *devinfo = container_of(opaque,
+			struct nfs42_layoutstat_devinfo, ld_private);
+	__be32 *start;
+
+	/* layoutupdate length */
+	start = xdr_reserve_space(xdr, 4);
+	ff_layout_encode_ff_layoutupdate(xdr, devinfo, opaque->data);
+
+	*start = cpu_to_be32((xdr->p - start - 1) * 4);
+}
+
+static void
+ff_layout_free_layoutstats(struct nfs4_xdr_opaque_data *opaque)
+{
+	struct nfs4_ff_layout_mirror *mirror = opaque->data;
+
+	ff_layout_put_mirror(mirror);
+}
+
+static const struct nfs4_xdr_opaque_ops layoutstat_ops = {
+	.encode = ff_layout_encode_layoutstats,
+	.free	= ff_layout_free_layoutstats,
+};
+
+static int
+ff_layout_mirror_prepare_stats(struct pnfs_layout_hdr *lo,
+			       struct nfs42_layoutstat_devinfo *devinfo,
+			       int dev_limit)
+{
+	struct nfs4_flexfile_layout *ff_layout = FF_LAYOUT_FROM_HDR(lo);
+	struct nfs4_ff_layout_mirror *mirror;
+	struct nfs4_deviceid_node *dev;
+	int i = 0;
+
+	list_for_each_entry(mirror, &ff_layout->mirrors, mirrors) {
+		if (i >= dev_limit)
+			break;
+		if (IS_ERR_OR_NULL(mirror->mirror_ds))
+			continue;
+		if (!test_and_clear_bit(NFS4_FF_MIRROR_STAT_AVAIL, &mirror->flags))
+			continue;
+		/* mirror refcount put in cleanup_layoutstats */
+		if (!refcount_inc_not_zero(&mirror->ref))
+			continue;
+		dev = &mirror->mirror_ds->id_node; 
+		memcpy(&devinfo->dev_id, &dev->deviceid, NFS4_DEVICEID4_SIZE);
+		devinfo->offset = 0;
+		devinfo->length = NFS4_MAX_UINT64;
+		spin_lock(&mirror->lock);
+		devinfo->read_count = mirror->read_stat.io_stat.ops_completed;
+		devinfo->read_bytes = mirror->read_stat.io_stat.bytes_completed;
+		devinfo->write_count = mirror->write_stat.io_stat.ops_completed;
+		devinfo->write_bytes = mirror->write_stat.io_stat.bytes_completed;
+		spin_unlock(&mirror->lock);
+		devinfo->layout_type = LAYOUT_FLEX_FILES;
+		devinfo->ld_private.ops = &layoutstat_ops;
+		devinfo->ld_private.data = mirror;
+
+		devinfo++;
+		i++;
+	}
+	return i;
+}
+
+static int
+ff_layout_prepare_layoutstats(struct nfs42_layoutstat_args *args)
+{
+	struct nfs4_flexfile_layout *ff_layout;
+	const int dev_count = PNFS_LAYOUTSTATS_MAXDEV;
+
+	/* For now, send at most PNFS_LAYOUTSTATS_MAXDEV statistics */
+	args->devinfo = kmalloc_array(dev_count, sizeof(*args->devinfo), GFP_NOIO);
+	if (!args->devinfo)
+		return -ENOMEM;
+
+	spin_lock(&args->inode->i_lock);
+	ff_layout = FF_LAYOUT_FROM_HDR(NFS_I(args->inode)->layout);
+	args->num_dev = ff_layout_mirror_prepare_stats(&ff_layout->generic_hdr,
+			&args->devinfo[0], dev_count);
+	spin_unlock(&args->inode->i_lock);
+	if (!args->num_dev) {
+		kfree(args->devinfo);
+		args->devinfo = NULL;
+		return -ENOENT;
+	}
+
+	return 0;
+}
+
+static int
+ff_layout_set_layoutdriver(struct nfs_server *server,
+		const struct nfs_fh *dummy)
+{
+#if IS_ENABLED(CONFIG_NFS_V4_2)
+	server->caps |= NFS_CAP_LAYOUTSTATS;
+#endif
+	return 0;
+}
+
+static const struct pnfs_commit_ops ff_layout_commit_ops = {
+	.setup_ds_info		= ff_layout_setup_ds_info,
+	.release_ds_info	= ff_layout_release_ds_info,
+	.mark_request_commit	= pnfs_layout_mark_request_commit,
+	.clear_request_commit	= pnfs_generic_clear_request_commit,
+	.scan_commit_lists	= pnfs_generic_scan_commit_lists,
+	.recover_commit_reqs	= pnfs_generic_recover_commit_reqs,
+	.commit_pagelist	= ff_layout_commit_pagelist,
+};
+
+static struct pnfs_layoutdriver_type flexfilelayout_type = {
+	.id			= LAYOUT_FLEX_FILES,
+	.name			= "LAYOUT_FLEX_FILES",
+	.owner			= THIS_MODULE,
+	.flags			= PNFS_LAYOUTGET_ON_OPEN,
+	.max_layoutget_response	= 4096, /* 1 page or so... */
+	.set_layoutdriver	= ff_layout_set_layoutdriver,
+	.alloc_layout_hdr	= ff_layout_alloc_layout_hdr,
+	.free_layout_hdr	= ff_layout_free_layout_hdr,
+	.alloc_lseg		= ff_layout_alloc_lseg,
+	.free_lseg		= ff_layout_free_lseg,
+	.add_lseg		= ff_layout_add_lseg,
+	.pg_read_ops		= &ff_layout_pg_read_ops,
+	.pg_write_ops		= &ff_layout_pg_write_ops,
+	.get_ds_info		= ff_layout_get_ds_info,
+	.free_deviceid_node	= ff_layout_free_deviceid_node,
+	.read_pagelist		= ff_layout_read_pagelist,
+	.write_pagelist		= ff_layout_write_pagelist,
+	.alloc_deviceid_node    = ff_layout_alloc_deviceid_node,
+	.prepare_layoutreturn   = ff_layout_prepare_layoutreturn,
+	.sync			= pnfs_nfs_generic_sync,
+	.prepare_layoutstats	= ff_layout_prepare_layoutstats,
+};
+
+static int __init nfs4flexfilelayout_init(void)
+{
+	printk(KERN_INFO "%s: NFSv4 Flexfile Layout Driver Registering...\n",
+	       __func__);
+	return pnfs_register_layoutdriver(&flexfilelayout_type);
+}
+
+static void __exit nfs4flexfilelayout_exit(void)
+{
+	printk(KERN_INFO "%s: NFSv4 Flexfile Layout Driver Unregistering...\n",
+	       __func__);
+	pnfs_unregister_layoutdriver(&flexfilelayout_type);
+}
+
+MODULE_ALIAS("nfs-layouttype4-4");
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("The NFSv4 flexfile layout driver");
+
+module_init(nfs4flexfilelayout_init);
+module_exit(nfs4flexfilelayout_exit);
+
+module_param(io_maxretrans, ushort, 0644);
+MODULE_PARM_DESC(io_maxretrans, "The  number of times the NFSv4.1 client "
+			"retries an I/O request before returning an error. ");
diff --git a/fs/nfs/flexfilelayout/flexfilelayout.h b/fs/nfs/flexfilelayout/flexfilelayout.h
new file mode 100644
index 000000000..354a031c6
--- /dev/null
+++ b/fs/nfs/flexfilelayout/flexfilelayout.h
@@ -0,0 +1,226 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * NFSv4 flexfile layout driver data structures.
+ *
+ * Copyright (c) 2014, Primary Data, Inc. All rights reserved.
+ *
+ * Tao Peng <bergwolf@primarydata.com>
+ */
+
+#ifndef FS_NFS_NFS4FLEXFILELAYOUT_H
+#define FS_NFS_NFS4FLEXFILELAYOUT_H
+
+#define FF_FLAGS_NO_LAYOUTCOMMIT 1
+#define FF_FLAGS_NO_IO_THRU_MDS  2
+#define FF_FLAGS_NO_READ_IO      4
+
+#include <linux/refcount.h>
+#include "../pnfs.h"
+
+/* XXX: Let's filter out insanely large mirror count for now to avoid oom
+ * due to network error etc. */
+#define NFS4_FLEXFILE_LAYOUT_MAX_MIRROR_CNT 4096
+
+/* LAYOUTSTATS report interval in ms */
+#define FF_LAYOUTSTATS_REPORT_INTERVAL (60000L)
+#define FF_LAYOUTSTATS_MAXDEV 4
+
+struct nfs4_ff_ds_version {
+	u32				version;
+	u32				minor_version;
+	u32				rsize;
+	u32				wsize;
+	bool				tightly_coupled;
+};
+
+/* chained in global deviceid hlist */
+struct nfs4_ff_layout_ds {
+	struct nfs4_deviceid_node	id_node;
+	u32				ds_versions_cnt;
+	struct nfs4_ff_ds_version	*ds_versions;
+	struct nfs4_pnfs_ds		*ds;
+};
+
+struct nfs4_ff_layout_ds_err {
+	struct list_head		list; /* linked in mirror error_list */
+	u64				offset;
+	u64				length;
+	int				status;
+	enum nfs_opnum4			opnum;
+	nfs4_stateid			stateid;
+	struct nfs4_deviceid		deviceid;
+};
+
+struct nfs4_ff_io_stat {
+	__u64				ops_requested;
+	__u64				bytes_requested;
+	__u64				ops_completed;
+	__u64				bytes_completed;
+	__u64				bytes_not_delivered;
+	ktime_t				total_busy_time;
+	ktime_t				aggregate_completion_time;
+};
+
+struct nfs4_ff_busy_timer {
+	ktime_t start_time;
+	atomic_t n_ops;
+};
+
+struct nfs4_ff_layoutstat {
+	struct nfs4_ff_io_stat io_stat;
+	struct nfs4_ff_busy_timer busy_timer;
+};
+
+struct nfs4_ff_layout_mirror {
+	struct pnfs_layout_hdr		*layout;
+	struct list_head		mirrors;
+	u32				ds_count;
+	u32				efficiency;
+	struct nfs4_deviceid		devid;
+	struct nfs4_ff_layout_ds	*mirror_ds;
+	u32				fh_versions_cnt;
+	struct nfs_fh			*fh_versions;
+	nfs4_stateid			stateid;
+	const struct cred __rcu		*ro_cred;
+	const struct cred __rcu		*rw_cred;
+	refcount_t			ref;
+	spinlock_t			lock;
+	unsigned long			flags;
+	struct nfs4_ff_layoutstat	read_stat;
+	struct nfs4_ff_layoutstat	write_stat;
+	ktime_t				start_time;
+	u32				report_interval;
+};
+
+#define NFS4_FF_MIRROR_STAT_AVAIL	(0)
+
+struct nfs4_ff_layout_segment {
+	struct pnfs_layout_segment	generic_hdr;
+	u64				stripe_unit;
+	u32				flags;
+	u32				mirror_array_cnt;
+	struct nfs4_ff_layout_mirror	*mirror_array[];
+};
+
+struct nfs4_flexfile_layout {
+	struct pnfs_layout_hdr generic_hdr;
+	struct pnfs_ds_commit_info commit_info;
+	struct list_head	mirrors;
+	struct list_head	error_list; /* nfs4_ff_layout_ds_err */
+	ktime_t			last_report_time; /* Layoutstat report times */
+};
+
+struct nfs4_flexfile_layoutreturn_args {
+	struct list_head errors;
+	struct nfs42_layoutstat_devinfo devinfo[FF_LAYOUTSTATS_MAXDEV];
+	unsigned int num_errors;
+	unsigned int num_dev;
+	struct page *pages[1];
+};
+
+static inline struct nfs4_flexfile_layout *
+FF_LAYOUT_FROM_HDR(struct pnfs_layout_hdr *lo)
+{
+	return container_of(lo, struct nfs4_flexfile_layout, generic_hdr);
+}
+
+static inline struct nfs4_ff_layout_segment *
+FF_LAYOUT_LSEG(struct pnfs_layout_segment *lseg)
+{
+	return container_of(lseg,
+			    struct nfs4_ff_layout_segment,
+			    generic_hdr);
+}
+
+static inline struct nfs4_ff_layout_ds *
+FF_LAYOUT_MIRROR_DS(struct nfs4_deviceid_node *node)
+{
+	return container_of(node, struct nfs4_ff_layout_ds, id_node);
+}
+
+static inline struct nfs4_ff_layout_mirror *
+FF_LAYOUT_COMP(struct pnfs_layout_segment *lseg, u32 idx)
+{
+	struct nfs4_ff_layout_segment *fls = FF_LAYOUT_LSEG(lseg);
+
+	if (idx < fls->mirror_array_cnt)
+		return fls->mirror_array[idx];
+	return NULL;
+}
+
+static inline struct nfs4_deviceid_node *
+FF_LAYOUT_DEVID_NODE(struct pnfs_layout_segment *lseg, u32 idx)
+{
+	struct nfs4_ff_layout_mirror *mirror = FF_LAYOUT_COMP(lseg, idx);
+
+	if (mirror != NULL) {
+		struct nfs4_ff_layout_ds *mirror_ds = mirror->mirror_ds;
+
+		if (!IS_ERR_OR_NULL(mirror_ds))
+			return &mirror_ds->id_node;
+	}
+	return NULL;
+}
+
+static inline u32
+FF_LAYOUT_MIRROR_COUNT(struct pnfs_layout_segment *lseg)
+{
+	return FF_LAYOUT_LSEG(lseg)->mirror_array_cnt;
+}
+
+static inline bool
+ff_layout_no_fallback_to_mds(struct pnfs_layout_segment *lseg)
+{
+	return FF_LAYOUT_LSEG(lseg)->flags & FF_FLAGS_NO_IO_THRU_MDS;
+}
+
+static inline bool
+ff_layout_no_read_on_rw(struct pnfs_layout_segment *lseg)
+{
+	return FF_LAYOUT_LSEG(lseg)->flags & FF_FLAGS_NO_READ_IO;
+}
+
+static inline int
+nfs4_ff_layout_ds_version(const struct nfs4_ff_layout_mirror *mirror)
+{
+	return mirror->mirror_ds->ds_versions[0].version;
+}
+
+struct nfs4_ff_layout_ds *
+nfs4_ff_alloc_deviceid_node(struct nfs_server *server, struct pnfs_device *pdev,
+			    gfp_t gfp_flags);
+void nfs4_ff_layout_put_deviceid(struct nfs4_ff_layout_ds *mirror_ds);
+void nfs4_ff_layout_free_deviceid(struct nfs4_ff_layout_ds *mirror_ds);
+int ff_layout_track_ds_error(struct nfs4_flexfile_layout *flo,
+			     struct nfs4_ff_layout_mirror *mirror, u64 offset,
+			     u64 length, int status, enum nfs_opnum4 opnum,
+			     gfp_t gfp_flags);
+void ff_layout_send_layouterror(struct pnfs_layout_segment *lseg);
+int ff_layout_encode_ds_ioerr(struct xdr_stream *xdr, const struct list_head *head);
+void ff_layout_free_ds_ioerr(struct list_head *head);
+unsigned int ff_layout_fetch_ds_ioerr(struct pnfs_layout_hdr *lo,
+		const struct pnfs_layout_range *range,
+		struct list_head *head,
+		unsigned int maxnum);
+struct nfs_fh *
+nfs4_ff_layout_select_ds_fh(struct nfs4_ff_layout_mirror *mirror);
+void
+nfs4_ff_layout_select_ds_stateid(const struct nfs4_ff_layout_mirror *mirror,
+		nfs4_stateid *stateid);
+
+struct nfs4_pnfs_ds *
+nfs4_ff_layout_prepare_ds(struct pnfs_layout_segment *lseg,
+			  struct nfs4_ff_layout_mirror *mirror,
+			  bool fail_return);
+
+struct rpc_clnt *
+nfs4_ff_find_or_create_ds_client(struct nfs4_ff_layout_mirror *mirror,
+				 struct nfs_client *ds_clp,
+				 struct inode *inode);
+const struct cred *ff_layout_get_ds_cred(struct nfs4_ff_layout_mirror *mirror,
+					 const struct pnfs_layout_range *range,
+					 const struct cred *mdscred);
+bool ff_layout_avoid_mds_available_ds(struct pnfs_layout_segment *lseg);
+bool ff_layout_avoid_read_on_rw(struct pnfs_layout_segment *lseg);
+
+#endif /* FS_NFS_NFS4FLEXFILELAYOUT_H */
diff --git a/fs/nfs/flexfilelayout/flexfilelayoutdev.c b/fs/nfs/flexfilelayout/flexfilelayoutdev.c
new file mode 100644
index 000000000..1f1229710
--- /dev/null
+++ b/fs/nfs/flexfilelayout/flexfilelayoutdev.c
@@ -0,0 +1,619 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Device operations for the pnfs nfs4 file layout driver.
+ *
+ * Copyright (c) 2014, Primary Data, Inc. All rights reserved.
+ *
+ * Tao Peng <bergwolf@primarydata.com>
+ */
+
+#include <linux/nfs_fs.h>
+#include <linux/vmalloc.h>
+#include <linux/module.h>
+#include <linux/sunrpc/addr.h>
+
+#include "../internal.h"
+#include "../nfs4session.h"
+#include "flexfilelayout.h"
+
+#define NFSDBG_FACILITY		NFSDBG_PNFS_LD
+
+static unsigned int dataserver_timeo = NFS_DEF_TCP_TIMEO;
+static unsigned int dataserver_retrans;
+
+static bool ff_layout_has_available_ds(struct pnfs_layout_segment *lseg);
+
+void nfs4_ff_layout_put_deviceid(struct nfs4_ff_layout_ds *mirror_ds)
+{
+	if (!IS_ERR_OR_NULL(mirror_ds))
+		nfs4_put_deviceid_node(&mirror_ds->id_node);
+}
+
+void nfs4_ff_layout_free_deviceid(struct nfs4_ff_layout_ds *mirror_ds)
+{
+	nfs4_print_deviceid(&mirror_ds->id_node.deviceid);
+	nfs4_pnfs_ds_put(mirror_ds->ds);
+	kfree(mirror_ds->ds_versions);
+	kfree_rcu(mirror_ds, id_node.rcu);
+}
+
+/* Decode opaque device data and construct new_ds using it */
+struct nfs4_ff_layout_ds *
+nfs4_ff_alloc_deviceid_node(struct nfs_server *server, struct pnfs_device *pdev,
+			    gfp_t gfp_flags)
+{
+	struct xdr_stream stream;
+	struct xdr_buf buf;
+	struct page *scratch;
+	struct list_head dsaddrs;
+	struct nfs4_pnfs_ds_addr *da;
+	struct nfs4_ff_layout_ds *new_ds = NULL;
+	struct nfs4_ff_ds_version *ds_versions = NULL;
+	u32 mp_count;
+	u32 version_count;
+	__be32 *p;
+	int i, ret = -ENOMEM;
+
+	/* set up xdr stream */
+	scratch = alloc_page(gfp_flags);
+	if (!scratch)
+		goto out_err;
+
+	new_ds = kzalloc(sizeof(struct nfs4_ff_layout_ds), gfp_flags);
+	if (!new_ds)
+		goto out_scratch;
+
+	nfs4_init_deviceid_node(&new_ds->id_node,
+				server,
+				&pdev->dev_id);
+	INIT_LIST_HEAD(&dsaddrs);
+
+	xdr_init_decode_pages(&stream, &buf, pdev->pages, pdev->pglen);
+	xdr_set_scratch_buffer(&stream, page_address(scratch), PAGE_SIZE);
+
+	/* multipath count */
+	p = xdr_inline_decode(&stream, 4);
+	if (unlikely(!p))
+		goto out_err_drain_dsaddrs;
+	mp_count = be32_to_cpup(p);
+	dprintk("%s: multipath ds count %d\n", __func__, mp_count);
+
+	for (i = 0; i < mp_count; i++) {
+		/* multipath ds */
+		da = nfs4_decode_mp_ds_addr(server->nfs_client->cl_net,
+					    &stream, gfp_flags);
+		if (da)
+			list_add_tail(&da->da_node, &dsaddrs);
+	}
+	if (list_empty(&dsaddrs)) {
+		dprintk("%s: no suitable DS addresses found\n",
+			__func__);
+		ret = -ENOMEDIUM;
+		goto out_err_drain_dsaddrs;
+	}
+
+	/* version count */
+	p = xdr_inline_decode(&stream, 4);
+	if (unlikely(!p))
+		goto out_err_drain_dsaddrs;
+	version_count = be32_to_cpup(p);
+	dprintk("%s: version count %d\n", __func__, version_count);
+
+	ds_versions = kcalloc(version_count,
+			      sizeof(struct nfs4_ff_ds_version),
+			      gfp_flags);
+	if (!ds_versions)
+		goto out_scratch;
+
+	for (i = 0; i < version_count; i++) {
+		/* 20 = version(4) + minor_version(4) + rsize(4) + wsize(4) +
+		 * tightly_coupled(4) */
+		p = xdr_inline_decode(&stream, 20);
+		if (unlikely(!p))
+			goto out_err_drain_dsaddrs;
+		ds_versions[i].version = be32_to_cpup(p++);
+		ds_versions[i].minor_version = be32_to_cpup(p++);
+		ds_versions[i].rsize = nfs_block_size(be32_to_cpup(p++), NULL);
+		ds_versions[i].wsize = nfs_block_size(be32_to_cpup(p++), NULL);
+		ds_versions[i].tightly_coupled = be32_to_cpup(p);
+
+		if (ds_versions[i].rsize > NFS_MAX_FILE_IO_SIZE)
+			ds_versions[i].rsize = NFS_MAX_FILE_IO_SIZE;
+		if (ds_versions[i].wsize > NFS_MAX_FILE_IO_SIZE)
+			ds_versions[i].wsize = NFS_MAX_FILE_IO_SIZE;
+
+		/*
+		 * check for valid major/minor combination.
+		 * currently we support dataserver which talk:
+		 *   v3, v4.0, v4.1, v4.2
+		 */
+		if (!((ds_versions[i].version == 3 && ds_versions[i].minor_version == 0) ||
+			(ds_versions[i].version == 4 && ds_versions[i].minor_version < 3))) {
+			dprintk("%s: [%d] unsupported ds version %d-%d\n", __func__,
+				i, ds_versions[i].version,
+				ds_versions[i].minor_version);
+			ret = -EPROTONOSUPPORT;
+			goto out_err_drain_dsaddrs;
+		}
+
+		dprintk("%s: [%d] vers %u minor_ver %u rsize %u wsize %u coupled %d\n",
+			__func__, i, ds_versions[i].version,
+			ds_versions[i].minor_version,
+			ds_versions[i].rsize,
+			ds_versions[i].wsize,
+			ds_versions[i].tightly_coupled);
+	}
+
+	new_ds->ds_versions = ds_versions;
+	new_ds->ds_versions_cnt = version_count;
+
+	new_ds->ds = nfs4_pnfs_ds_add(&dsaddrs, gfp_flags);
+	if (!new_ds->ds)
+		goto out_err_drain_dsaddrs;
+
+	/* If DS was already in cache, free ds addrs */
+	while (!list_empty(&dsaddrs)) {
+		da = list_first_entry(&dsaddrs,
+				      struct nfs4_pnfs_ds_addr,
+				      da_node);
+		list_del_init(&da->da_node);
+		kfree(da->da_remotestr);
+		kfree(da);
+	}
+
+	__free_page(scratch);
+	return new_ds;
+
+out_err_drain_dsaddrs:
+	while (!list_empty(&dsaddrs)) {
+		da = list_first_entry(&dsaddrs, struct nfs4_pnfs_ds_addr,
+				      da_node);
+		list_del_init(&da->da_node);
+		kfree(da->da_remotestr);
+		kfree(da);
+	}
+
+	kfree(ds_versions);
+out_scratch:
+	__free_page(scratch);
+out_err:
+	kfree(new_ds);
+
+	dprintk("%s ERROR: returning %d\n", __func__, ret);
+	return NULL;
+}
+
+static void extend_ds_error(struct nfs4_ff_layout_ds_err *err,
+			    u64 offset, u64 length)
+{
+	u64 end;
+
+	end = max_t(u64, pnfs_end_offset(err->offset, err->length),
+		    pnfs_end_offset(offset, length));
+	err->offset = min_t(u64, err->offset, offset);
+	err->length = end - err->offset;
+}
+
+static int
+ff_ds_error_match(const struct nfs4_ff_layout_ds_err *e1,
+		const struct nfs4_ff_layout_ds_err *e2)
+{
+	int ret;
+
+	if (e1->opnum != e2->opnum)
+		return e1->opnum < e2->opnum ? -1 : 1;
+	if (e1->status != e2->status)
+		return e1->status < e2->status ? -1 : 1;
+	ret = memcmp(e1->stateid.data, e2->stateid.data,
+			sizeof(e1->stateid.data));
+	if (ret != 0)
+		return ret;
+	ret = memcmp(&e1->deviceid, &e2->deviceid, sizeof(e1->deviceid));
+	if (ret != 0)
+		return ret;
+	if (pnfs_end_offset(e1->offset, e1->length) < e2->offset)
+		return -1;
+	if (e1->offset > pnfs_end_offset(e2->offset, e2->length))
+		return 1;
+	/* If ranges overlap or are contiguous, they are the same */
+	return 0;
+}
+
+static void
+ff_layout_add_ds_error_locked(struct nfs4_flexfile_layout *flo,
+			      struct nfs4_ff_layout_ds_err *dserr)
+{
+	struct nfs4_ff_layout_ds_err *err, *tmp;
+	struct list_head *head = &flo->error_list;
+	int match;
+
+	/* Do insertion sort w/ merges */
+	list_for_each_entry_safe(err, tmp, &flo->error_list, list) {
+		match = ff_ds_error_match(err, dserr);
+		if (match < 0)
+			continue;
+		if (match > 0) {
+			/* Add entry "dserr" _before_ entry "err" */
+			head = &err->list;
+			break;
+		}
+		/* Entries match, so merge "err" into "dserr" */
+		extend_ds_error(dserr, err->offset, err->length);
+		list_replace(&err->list, &dserr->list);
+		kfree(err);
+		return;
+	}
+
+	list_add_tail(&dserr->list, head);
+}
+
+int ff_layout_track_ds_error(struct nfs4_flexfile_layout *flo,
+			     struct nfs4_ff_layout_mirror *mirror, u64 offset,
+			     u64 length, int status, enum nfs_opnum4 opnum,
+			     gfp_t gfp_flags)
+{
+	struct nfs4_ff_layout_ds_err *dserr;
+
+	if (status == 0)
+		return 0;
+
+	if (IS_ERR_OR_NULL(mirror->mirror_ds))
+		return -EINVAL;
+
+	dserr = kmalloc(sizeof(*dserr), gfp_flags);
+	if (!dserr)
+		return -ENOMEM;
+
+	INIT_LIST_HEAD(&dserr->list);
+	dserr->offset = offset;
+	dserr->length = length;
+	dserr->status = status;
+	dserr->opnum = opnum;
+	nfs4_stateid_copy(&dserr->stateid, &mirror->stateid);
+	memcpy(&dserr->deviceid, &mirror->mirror_ds->id_node.deviceid,
+	       NFS4_DEVICEID4_SIZE);
+
+	spin_lock(&flo->generic_hdr.plh_inode->i_lock);
+	ff_layout_add_ds_error_locked(flo, dserr);
+	spin_unlock(&flo->generic_hdr.plh_inode->i_lock);
+	return 0;
+}
+
+static const struct cred *
+ff_layout_get_mirror_cred(struct nfs4_ff_layout_mirror *mirror, u32 iomode)
+{
+	const struct cred *cred, __rcu **pcred;
+
+	if (iomode == IOMODE_READ)
+		pcred = &mirror->ro_cred;
+	else
+		pcred = &mirror->rw_cred;
+
+	rcu_read_lock();
+	do {
+		cred = rcu_dereference(*pcred);
+		if (!cred)
+			break;
+
+		cred = get_cred_rcu(cred);
+	} while(!cred);
+	rcu_read_unlock();
+	return cred;
+}
+
+struct nfs_fh *
+nfs4_ff_layout_select_ds_fh(struct nfs4_ff_layout_mirror *mirror)
+{
+	/* FIXME: For now assume there is only 1 version available for the DS */
+	return &mirror->fh_versions[0];
+}
+
+void
+nfs4_ff_layout_select_ds_stateid(const struct nfs4_ff_layout_mirror *mirror,
+		nfs4_stateid *stateid)
+{
+	if (nfs4_ff_layout_ds_version(mirror) == 4)
+		nfs4_stateid_copy(stateid, &mirror->stateid);
+}
+
+static bool
+ff_layout_init_mirror_ds(struct pnfs_layout_hdr *lo,
+			 struct nfs4_ff_layout_mirror *mirror)
+{
+	if (mirror == NULL)
+		goto outerr;
+	if (mirror->mirror_ds == NULL) {
+		struct nfs4_deviceid_node *node;
+		struct nfs4_ff_layout_ds *mirror_ds = ERR_PTR(-ENODEV);
+
+		node = nfs4_find_get_deviceid(NFS_SERVER(lo->plh_inode),
+				&mirror->devid, lo->plh_lc_cred,
+				GFP_KERNEL);
+		if (node)
+			mirror_ds = FF_LAYOUT_MIRROR_DS(node);
+
+		/* check for race with another call to this function */
+		if (cmpxchg(&mirror->mirror_ds, NULL, mirror_ds) &&
+		    mirror_ds != ERR_PTR(-ENODEV))
+			nfs4_put_deviceid_node(node);
+	}
+
+	if (IS_ERR(mirror->mirror_ds))
+		goto outerr;
+
+	return true;
+outerr:
+	return false;
+}
+
+/**
+ * nfs4_ff_layout_prepare_ds - prepare a DS connection for an RPC call
+ * @lseg: the layout segment we're operating on
+ * @mirror: layout mirror describing the DS to use
+ * @fail_return: return layout on connect failure?
+ *
+ * Try to prepare a DS connection to accept an RPC call. This involves
+ * selecting a mirror to use and connecting the client to it if it's not
+ * already connected.
+ *
+ * Since we only need a single functioning mirror to satisfy a read, we don't
+ * want to return the layout if there is one. For writes though, any down
+ * mirror should result in a LAYOUTRETURN. @fail_return is how we distinguish
+ * between the two cases.
+ *
+ * Returns a pointer to a connected DS object on success or NULL on failure.
+ */
+struct nfs4_pnfs_ds *
+nfs4_ff_layout_prepare_ds(struct pnfs_layout_segment *lseg,
+			  struct nfs4_ff_layout_mirror *mirror,
+			  bool fail_return)
+{
+	struct nfs4_pnfs_ds *ds = NULL;
+	struct inode *ino = lseg->pls_layout->plh_inode;
+	struct nfs_server *s = NFS_SERVER(ino);
+	unsigned int max_payload;
+	int status;
+
+	if (!ff_layout_init_mirror_ds(lseg->pls_layout, mirror))
+		goto noconnect;
+
+	ds = mirror->mirror_ds->ds;
+	if (READ_ONCE(ds->ds_clp))
+		goto out;
+	/* matching smp_wmb() in _nfs4_pnfs_v3/4_ds_connect */
+	smp_rmb();
+
+	/* FIXME: For now we assume the server sent only one version of NFS
+	 * to use for the DS.
+	 */
+	status = nfs4_pnfs_ds_connect(s, ds, &mirror->mirror_ds->id_node,
+			     dataserver_timeo, dataserver_retrans,
+			     mirror->mirror_ds->ds_versions[0].version,
+			     mirror->mirror_ds->ds_versions[0].minor_version);
+
+	/* connect success, check rsize/wsize limit */
+	if (!status) {
+		max_payload =
+			nfs_block_size(rpc_max_payload(ds->ds_clp->cl_rpcclient),
+				       NULL);
+		if (mirror->mirror_ds->ds_versions[0].rsize > max_payload)
+			mirror->mirror_ds->ds_versions[0].rsize = max_payload;
+		if (mirror->mirror_ds->ds_versions[0].wsize > max_payload)
+			mirror->mirror_ds->ds_versions[0].wsize = max_payload;
+		goto out;
+	}
+noconnect:
+	ff_layout_track_ds_error(FF_LAYOUT_FROM_HDR(lseg->pls_layout),
+				 mirror, lseg->pls_range.offset,
+				 lseg->pls_range.length, NFS4ERR_NXIO,
+				 OP_ILLEGAL, GFP_NOIO);
+	ff_layout_send_layouterror(lseg);
+	if (fail_return || !ff_layout_has_available_ds(lseg))
+		pnfs_error_mark_layout_for_return(ino, lseg);
+	ds = NULL;
+out:
+	return ds;
+}
+
+const struct cred *
+ff_layout_get_ds_cred(struct nfs4_ff_layout_mirror *mirror,
+		      const struct pnfs_layout_range *range,
+		      const struct cred *mdscred)
+{
+	const struct cred *cred;
+
+	if (mirror && !mirror->mirror_ds->ds_versions[0].tightly_coupled) {
+		cred = ff_layout_get_mirror_cred(mirror, range->iomode);
+		if (!cred)
+			cred = get_cred(mdscred);
+	} else {
+		cred = get_cred(mdscred);
+	}
+	return cred;
+}
+
+/**
+ * nfs4_ff_find_or_create_ds_client - Find or create a DS rpc client
+ * @mirror: pointer to the mirror
+ * @ds_clp: nfs_client for the DS
+ * @inode: pointer to inode
+ *
+ * Find or create a DS rpc client with th MDS server rpc client auth flavor
+ * in the nfs_client cl_ds_clients list.
+ */
+struct rpc_clnt *
+nfs4_ff_find_or_create_ds_client(struct nfs4_ff_layout_mirror *mirror,
+				 struct nfs_client *ds_clp, struct inode *inode)
+{
+	switch (mirror->mirror_ds->ds_versions[0].version) {
+	case 3:
+		/* For NFSv3 DS, flavor is set when creating DS connections */
+		return ds_clp->cl_rpcclient;
+	case 4:
+		return nfs4_find_or_create_ds_client(ds_clp, inode);
+	default:
+		BUG();
+	}
+}
+
+void ff_layout_free_ds_ioerr(struct list_head *head)
+{
+	struct nfs4_ff_layout_ds_err *err;
+
+	while (!list_empty(head)) {
+		err = list_first_entry(head,
+				struct nfs4_ff_layout_ds_err,
+				list);
+		list_del(&err->list);
+		kfree(err);
+	}
+}
+
+/* called with inode i_lock held */
+int ff_layout_encode_ds_ioerr(struct xdr_stream *xdr, const struct list_head *head)
+{
+	struct nfs4_ff_layout_ds_err *err;
+	__be32 *p;
+
+	list_for_each_entry(err, head, list) {
+		/* offset(8) + length(8) + stateid(NFS4_STATEID_SIZE)
+		 * + array length + deviceid(NFS4_DEVICEID4_SIZE)
+		 * + status(4) + opnum(4)
+		 */
+		p = xdr_reserve_space(xdr,
+				28 + NFS4_STATEID_SIZE + NFS4_DEVICEID4_SIZE);
+		if (unlikely(!p))
+			return -ENOBUFS;
+		p = xdr_encode_hyper(p, err->offset);
+		p = xdr_encode_hyper(p, err->length);
+		p = xdr_encode_opaque_fixed(p, &err->stateid,
+					    NFS4_STATEID_SIZE);
+		/* Encode 1 error */
+		*p++ = cpu_to_be32(1);
+		p = xdr_encode_opaque_fixed(p, &err->deviceid,
+					    NFS4_DEVICEID4_SIZE);
+		*p++ = cpu_to_be32(err->status);
+		*p++ = cpu_to_be32(err->opnum);
+		dprintk("%s: offset %llu length %llu status %d op %d\n",
+			__func__, err->offset, err->length, err->status,
+			err->opnum);
+	}
+
+	return 0;
+}
+
+static
+unsigned int do_layout_fetch_ds_ioerr(struct pnfs_layout_hdr *lo,
+				      const struct pnfs_layout_range *range,
+				      struct list_head *head,
+				      unsigned int maxnum)
+{
+	struct nfs4_flexfile_layout *flo = FF_LAYOUT_FROM_HDR(lo);
+	struct inode *inode = lo->plh_inode;
+	struct nfs4_ff_layout_ds_err *err, *n;
+	unsigned int ret = 0;
+
+	spin_lock(&inode->i_lock);
+	list_for_each_entry_safe(err, n, &flo->error_list, list) {
+		if (!pnfs_is_range_intersecting(err->offset,
+				pnfs_end_offset(err->offset, err->length),
+				range->offset,
+				pnfs_end_offset(range->offset, range->length)))
+			continue;
+		if (!maxnum)
+			break;
+		list_move(&err->list, head);
+		maxnum--;
+		ret++;
+	}
+	spin_unlock(&inode->i_lock);
+	return ret;
+}
+
+unsigned int ff_layout_fetch_ds_ioerr(struct pnfs_layout_hdr *lo,
+				      const struct pnfs_layout_range *range,
+				      struct list_head *head,
+				      unsigned int maxnum)
+{
+	unsigned int ret;
+
+	ret = do_layout_fetch_ds_ioerr(lo, range, head, maxnum);
+	/* If we're over the max, discard all remaining entries */
+	if (ret == maxnum) {
+		LIST_HEAD(discard);
+		do_layout_fetch_ds_ioerr(lo, range, &discard, -1);
+		ff_layout_free_ds_ioerr(&discard);
+	}
+	return ret;
+}
+
+static bool ff_read_layout_has_available_ds(struct pnfs_layout_segment *lseg)
+{
+	struct nfs4_ff_layout_mirror *mirror;
+	struct nfs4_deviceid_node *devid;
+	u32 idx;
+
+	for (idx = 0; idx < FF_LAYOUT_MIRROR_COUNT(lseg); idx++) {
+		mirror = FF_LAYOUT_COMP(lseg, idx);
+		if (mirror) {
+			if (!mirror->mirror_ds)
+				return true;
+			if (IS_ERR(mirror->mirror_ds))
+				continue;
+			devid = &mirror->mirror_ds->id_node;
+			if (!nfs4_test_deviceid_unavailable(devid))
+				return true;
+		}
+	}
+
+	return false;
+}
+
+static bool ff_rw_layout_has_available_ds(struct pnfs_layout_segment *lseg)
+{
+	struct nfs4_ff_layout_mirror *mirror;
+	struct nfs4_deviceid_node *devid;
+	u32 idx;
+
+	for (idx = 0; idx < FF_LAYOUT_MIRROR_COUNT(lseg); idx++) {
+		mirror = FF_LAYOUT_COMP(lseg, idx);
+		if (!mirror || IS_ERR(mirror->mirror_ds))
+			return false;
+		if (!mirror->mirror_ds)
+			continue;
+		devid = &mirror->mirror_ds->id_node;
+		if (nfs4_test_deviceid_unavailable(devid))
+			return false;
+	}
+
+	return FF_LAYOUT_MIRROR_COUNT(lseg) != 0;
+}
+
+static bool ff_layout_has_available_ds(struct pnfs_layout_segment *lseg)
+{
+	if (lseg->pls_range.iomode == IOMODE_READ)
+		return  ff_read_layout_has_available_ds(lseg);
+	/* Note: RW layout needs all mirrors available */
+	return ff_rw_layout_has_available_ds(lseg);
+}
+
+bool ff_layout_avoid_mds_available_ds(struct pnfs_layout_segment *lseg)
+{
+	return ff_layout_no_fallback_to_mds(lseg) ||
+	       ff_layout_has_available_ds(lseg);
+}
+
+bool ff_layout_avoid_read_on_rw(struct pnfs_layout_segment *lseg)
+{
+	return lseg->pls_range.iomode == IOMODE_RW &&
+	       ff_layout_no_read_on_rw(lseg);
+}
+
+module_param(dataserver_retrans, uint, 0644);
+MODULE_PARM_DESC(dataserver_retrans, "The  number of times the NFSv4.1 client "
+			"retries a request before it attempts further "
+			" recovery  action.");
+module_param(dataserver_timeo, uint, 0644);
+MODULE_PARM_DESC(dataserver_timeo, "The time (in tenths of a second) the "
+			"NFSv4.1  client  waits for a response from a "
+			" data server before it retries an NFS request.");
diff --git a/fs/nfs/fs_context.c b/fs/nfs/fs_context.c
new file mode 100644
index 000000000..d60c086c6
--- /dev/null
+++ b/fs/nfs/fs_context.c
@@ -0,0 +1,1520 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * linux/fs/nfs/fs_context.c
+ *
+ * Copyright (C) 1992 Rick Sladkey
+ * Conversion to new mount api Copyright (C) David Howells
+ *
+ * NFS mount handling.
+ *
+ * Split from fs/nfs/super.c by David Howells <dhowells@redhat.com>
+ */
+
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/fs_context.h>
+#include <linux/fs_parser.h>
+#include <linux/nfs_fs.h>
+#include <linux/nfs_mount.h>
+#include <linux/nfs4_mount.h>
+#include "nfs.h"
+#include "internal.h"
+
+#define NFSDBG_FACILITY		NFSDBG_MOUNT
+
+#if IS_ENABLED(CONFIG_NFS_V3)
+#define NFS_DEFAULT_VERSION 3
+#else
+#define NFS_DEFAULT_VERSION 2
+#endif
+
+#define NFS_MAX_CONNECTIONS 16
+
+enum nfs_param {
+	Opt_ac,
+	Opt_acdirmax,
+	Opt_acdirmin,
+	Opt_acl,
+	Opt_acregmax,
+	Opt_acregmin,
+	Opt_actimeo,
+	Opt_addr,
+	Opt_bg,
+	Opt_bsize,
+	Opt_clientaddr,
+	Opt_cto,
+	Opt_fg,
+	Opt_fscache,
+	Opt_fscache_flag,
+	Opt_hard,
+	Opt_intr,
+	Opt_local_lock,
+	Opt_lock,
+	Opt_lookupcache,
+	Opt_migration,
+	Opt_minorversion,
+	Opt_mountaddr,
+	Opt_mounthost,
+	Opt_mountport,
+	Opt_mountproto,
+	Opt_mountvers,
+	Opt_namelen,
+	Opt_nconnect,
+	Opt_port,
+	Opt_posix,
+	Opt_proto,
+	Opt_rdirplus,
+	Opt_rdma,
+	Opt_resvport,
+	Opt_retrans,
+	Opt_retry,
+	Opt_rsize,
+	Opt_sec,
+	Opt_sharecache,
+	Opt_sloppy,
+	Opt_soft,
+	Opt_softerr,
+	Opt_softreval,
+	Opt_source,
+	Opt_tcp,
+	Opt_timeo,
+	Opt_udp,
+	Opt_v,
+	Opt_vers,
+	Opt_wsize,
+};
+
+enum {
+	Opt_local_lock_all,
+	Opt_local_lock_flock,
+	Opt_local_lock_none,
+	Opt_local_lock_posix,
+};
+
+static const struct constant_table nfs_param_enums_local_lock[] = {
+	{ "all",		Opt_local_lock_all },
+	{ "flock",	Opt_local_lock_flock },
+	{ "posix",	Opt_local_lock_posix },
+	{ "none",		Opt_local_lock_none },
+	{}
+};
+
+enum {
+	Opt_lookupcache_all,
+	Opt_lookupcache_none,
+	Opt_lookupcache_positive,
+};
+
+static const struct constant_table nfs_param_enums_lookupcache[] = {
+	{ "all",		Opt_lookupcache_all },
+	{ "none",		Opt_lookupcache_none },
+	{ "pos",		Opt_lookupcache_positive },
+	{ "positive",		Opt_lookupcache_positive },
+	{}
+};
+
+static const struct fs_parameter_spec nfs_fs_parameters[] = {
+	fsparam_flag_no("ac",		Opt_ac),
+	fsparam_u32   ("acdirmax",	Opt_acdirmax),
+	fsparam_u32   ("acdirmin",	Opt_acdirmin),
+	fsparam_flag_no("acl",		Opt_acl),
+	fsparam_u32   ("acregmax",	Opt_acregmax),
+	fsparam_u32   ("acregmin",	Opt_acregmin),
+	fsparam_u32   ("actimeo",	Opt_actimeo),
+	fsparam_string("addr",		Opt_addr),
+	fsparam_flag  ("bg",		Opt_bg),
+	fsparam_u32   ("bsize",		Opt_bsize),
+	fsparam_string("clientaddr",	Opt_clientaddr),
+	fsparam_flag_no("cto",		Opt_cto),
+	fsparam_flag  ("fg",		Opt_fg),
+	fsparam_flag_no("fsc",		Opt_fscache_flag),
+	fsparam_string("fsc",		Opt_fscache),
+	fsparam_flag  ("hard",		Opt_hard),
+	__fsparam(NULL, "intr",		Opt_intr,
+		  fs_param_neg_with_no|fs_param_deprecated, NULL),
+	fsparam_enum  ("local_lock",	Opt_local_lock, nfs_param_enums_local_lock),
+	fsparam_flag_no("lock",		Opt_lock),
+	fsparam_enum  ("lookupcache",	Opt_lookupcache, nfs_param_enums_lookupcache),
+	fsparam_flag_no("migration",	Opt_migration),
+	fsparam_u32   ("minorversion",	Opt_minorversion),
+	fsparam_string("mountaddr",	Opt_mountaddr),
+	fsparam_string("mounthost",	Opt_mounthost),
+	fsparam_u32   ("mountport",	Opt_mountport),
+	fsparam_string("mountproto",	Opt_mountproto),
+	fsparam_u32   ("mountvers",	Opt_mountvers),
+	fsparam_u32   ("namlen",	Opt_namelen),
+	fsparam_u32   ("nconnect",	Opt_nconnect),
+	fsparam_string("nfsvers",	Opt_vers),
+	fsparam_u32   ("port",		Opt_port),
+	fsparam_flag_no("posix",	Opt_posix),
+	fsparam_string("proto",		Opt_proto),
+	fsparam_flag_no("rdirplus",	Opt_rdirplus),
+	fsparam_flag  ("rdma",		Opt_rdma),
+	fsparam_flag_no("resvport",	Opt_resvport),
+	fsparam_u32   ("retrans",	Opt_retrans),
+	fsparam_string("retry",		Opt_retry),
+	fsparam_u32   ("rsize",		Opt_rsize),
+	fsparam_string("sec",		Opt_sec),
+	fsparam_flag_no("sharecache",	Opt_sharecache),
+	fsparam_flag  ("sloppy",	Opt_sloppy),
+	fsparam_flag  ("soft",		Opt_soft),
+	fsparam_flag  ("softerr",	Opt_softerr),
+	fsparam_flag  ("softreval",	Opt_softreval),
+	fsparam_string("source",	Opt_source),
+	fsparam_flag  ("tcp",		Opt_tcp),
+	fsparam_u32   ("timeo",		Opt_timeo),
+	fsparam_flag  ("udp",		Opt_udp),
+	fsparam_flag  ("v2",		Opt_v),
+	fsparam_flag  ("v3",		Opt_v),
+	fsparam_flag  ("v4",		Opt_v),
+	fsparam_flag  ("v4.0",		Opt_v),
+	fsparam_flag  ("v4.1",		Opt_v),
+	fsparam_flag  ("v4.2",		Opt_v),
+	fsparam_string("vers",		Opt_vers),
+	fsparam_u32   ("wsize",		Opt_wsize),
+	{}
+};
+
+enum {
+	Opt_vers_2,
+	Opt_vers_3,
+	Opt_vers_4,
+	Opt_vers_4_0,
+	Opt_vers_4_1,
+	Opt_vers_4_2,
+};
+
+static const struct constant_table nfs_vers_tokens[] = {
+	{ "2",		Opt_vers_2 },
+	{ "3",		Opt_vers_3 },
+	{ "4",		Opt_vers_4 },
+	{ "4.0",	Opt_vers_4_0 },
+	{ "4.1",	Opt_vers_4_1 },
+	{ "4.2",	Opt_vers_4_2 },
+	{}
+};
+
+enum {
+	Opt_xprt_rdma,
+	Opt_xprt_rdma6,
+	Opt_xprt_tcp,
+	Opt_xprt_tcp6,
+	Opt_xprt_udp,
+	Opt_xprt_udp6,
+	nr__Opt_xprt
+};
+
+static const struct constant_table nfs_xprt_protocol_tokens[] = {
+	{ "rdma",	Opt_xprt_rdma },
+	{ "rdma6",	Opt_xprt_rdma6 },
+	{ "tcp",	Opt_xprt_tcp },
+	{ "tcp6",	Opt_xprt_tcp6 },
+	{ "udp",	Opt_xprt_udp },
+	{ "udp6",	Opt_xprt_udp6 },
+	{}
+};
+
+enum {
+	Opt_sec_krb5,
+	Opt_sec_krb5i,
+	Opt_sec_krb5p,
+	Opt_sec_lkey,
+	Opt_sec_lkeyi,
+	Opt_sec_lkeyp,
+	Opt_sec_none,
+	Opt_sec_spkm,
+	Opt_sec_spkmi,
+	Opt_sec_spkmp,
+	Opt_sec_sys,
+	nr__Opt_sec
+};
+
+static const struct constant_table nfs_secflavor_tokens[] = {
+	{ "krb5",	Opt_sec_krb5 },
+	{ "krb5i",	Opt_sec_krb5i },
+	{ "krb5p",	Opt_sec_krb5p },
+	{ "lkey",	Opt_sec_lkey },
+	{ "lkeyi",	Opt_sec_lkeyi },
+	{ "lkeyp",	Opt_sec_lkeyp },
+	{ "none",	Opt_sec_none },
+	{ "null",	Opt_sec_none },
+	{ "spkm3",	Opt_sec_spkm },
+	{ "spkm3i",	Opt_sec_spkmi },
+	{ "spkm3p",	Opt_sec_spkmp },
+	{ "sys",	Opt_sec_sys },
+	{}
+};
+
+/*
+ * Sanity-check a server address provided by the mount command.
+ *
+ * Address family must be initialized, and address must not be
+ * the ANY address for that family.
+ */
+static int nfs_verify_server_address(struct sockaddr *addr)
+{
+	switch (addr->sa_family) {
+	case AF_INET: {
+		struct sockaddr_in *sa = (struct sockaddr_in *)addr;
+		return sa->sin_addr.s_addr != htonl(INADDR_ANY);
+	}
+	case AF_INET6: {
+		struct in6_addr *sa = &((struct sockaddr_in6 *)addr)->sin6_addr;
+		return !ipv6_addr_any(sa);
+	}
+	}
+
+	dfprintk(MOUNT, "NFS: Invalid IP address specified\n");
+	return 0;
+}
+
+/*
+ * Sanity check the NFS transport protocol.
+ *
+ */
+static void nfs_validate_transport_protocol(struct nfs_fs_context *ctx)
+{
+	switch (ctx->nfs_server.protocol) {
+	case XPRT_TRANSPORT_UDP:
+	case XPRT_TRANSPORT_TCP:
+	case XPRT_TRANSPORT_RDMA:
+		break;
+	default:
+		ctx->nfs_server.protocol = XPRT_TRANSPORT_TCP;
+	}
+}
+
+/*
+ * For text based NFSv2/v3 mounts, the mount protocol transport default
+ * settings should depend upon the specified NFS transport.
+ */
+static void nfs_set_mount_transport_protocol(struct nfs_fs_context *ctx)
+{
+	nfs_validate_transport_protocol(ctx);
+
+	if (ctx->mount_server.protocol == XPRT_TRANSPORT_UDP ||
+	    ctx->mount_server.protocol == XPRT_TRANSPORT_TCP)
+			return;
+	switch (ctx->nfs_server.protocol) {
+	case XPRT_TRANSPORT_UDP:
+		ctx->mount_server.protocol = XPRT_TRANSPORT_UDP;
+		break;
+	case XPRT_TRANSPORT_TCP:
+	case XPRT_TRANSPORT_RDMA:
+		ctx->mount_server.protocol = XPRT_TRANSPORT_TCP;
+	}
+}
+
+/*
+ * Add 'flavor' to 'auth_info' if not already present.
+ * Returns true if 'flavor' ends up in the list, false otherwise
+ */
+static int nfs_auth_info_add(struct fs_context *fc,
+			     struct nfs_auth_info *auth_info,
+			     rpc_authflavor_t flavor)
+{
+	unsigned int i;
+	unsigned int max_flavor_len = ARRAY_SIZE(auth_info->flavors);
+
+	/* make sure this flavor isn't already in the list */
+	for (i = 0; i < auth_info->flavor_len; i++) {
+		if (flavor == auth_info->flavors[i])
+			return 0;
+	}
+
+	if (auth_info->flavor_len + 1 >= max_flavor_len)
+		return nfs_invalf(fc, "NFS: too many sec= flavors");
+
+	auth_info->flavors[auth_info->flavor_len++] = flavor;
+	return 0;
+}
+
+/*
+ * Parse the value of the 'sec=' option.
+ */
+static int nfs_parse_security_flavors(struct fs_context *fc,
+				      struct fs_parameter *param)
+{
+	struct nfs_fs_context *ctx = nfs_fc2context(fc);
+	rpc_authflavor_t pseudoflavor;
+	char *string = param->string, *p;
+	int ret;
+
+	dfprintk(MOUNT, "NFS: parsing %s=%s option\n", param->key, param->string);
+
+	while ((p = strsep(&string, ":")) != NULL) {
+		if (!*p)
+			continue;
+		switch (lookup_constant(nfs_secflavor_tokens, p, -1)) {
+		case Opt_sec_none:
+			pseudoflavor = RPC_AUTH_NULL;
+			break;
+		case Opt_sec_sys:
+			pseudoflavor = RPC_AUTH_UNIX;
+			break;
+		case Opt_sec_krb5:
+			pseudoflavor = RPC_AUTH_GSS_KRB5;
+			break;
+		case Opt_sec_krb5i:
+			pseudoflavor = RPC_AUTH_GSS_KRB5I;
+			break;
+		case Opt_sec_krb5p:
+			pseudoflavor = RPC_AUTH_GSS_KRB5P;
+			break;
+		case Opt_sec_lkey:
+			pseudoflavor = RPC_AUTH_GSS_LKEY;
+			break;
+		case Opt_sec_lkeyi:
+			pseudoflavor = RPC_AUTH_GSS_LKEYI;
+			break;
+		case Opt_sec_lkeyp:
+			pseudoflavor = RPC_AUTH_GSS_LKEYP;
+			break;
+		case Opt_sec_spkm:
+			pseudoflavor = RPC_AUTH_GSS_SPKM;
+			break;
+		case Opt_sec_spkmi:
+			pseudoflavor = RPC_AUTH_GSS_SPKMI;
+			break;
+		case Opt_sec_spkmp:
+			pseudoflavor = RPC_AUTH_GSS_SPKMP;
+			break;
+		default:
+			return nfs_invalf(fc, "NFS: sec=%s option not recognized", p);
+		}
+
+		ret = nfs_auth_info_add(fc, &ctx->auth_info, pseudoflavor);
+		if (ret < 0)
+			return ret;
+	}
+
+	return 0;
+}
+
+static int nfs_parse_version_string(struct fs_context *fc,
+				    const char *string)
+{
+	struct nfs_fs_context *ctx = nfs_fc2context(fc);
+
+	ctx->flags &= ~NFS_MOUNT_VER3;
+	switch (lookup_constant(nfs_vers_tokens, string, -1)) {
+	case Opt_vers_2:
+		ctx->version = 2;
+		break;
+	case Opt_vers_3:
+		ctx->flags |= NFS_MOUNT_VER3;
+		ctx->version = 3;
+		break;
+	case Opt_vers_4:
+		/* Backward compatibility option. In future,
+		 * the mount program should always supply
+		 * a NFSv4 minor version number.
+		 */
+		ctx->version = 4;
+		break;
+	case Opt_vers_4_0:
+		ctx->version = 4;
+		ctx->minorversion = 0;
+		break;
+	case Opt_vers_4_1:
+		ctx->version = 4;
+		ctx->minorversion = 1;
+		break;
+	case Opt_vers_4_2:
+		ctx->version = 4;
+		ctx->minorversion = 2;
+		break;
+	default:
+		return nfs_invalf(fc, "NFS: Unsupported NFS version");
+	}
+	return 0;
+}
+
+/*
+ * Parse a single mount parameter.
+ */
+static int nfs_fs_context_parse_param(struct fs_context *fc,
+				      struct fs_parameter *param)
+{
+	struct fs_parse_result result;
+	struct nfs_fs_context *ctx = nfs_fc2context(fc);
+	unsigned short protofamily, mountfamily;
+	unsigned int len;
+	int ret, opt;
+
+	dfprintk(MOUNT, "NFS:   parsing nfs mount option '%s'\n", param->key);
+
+	opt = fs_parse(fc, nfs_fs_parameters, param, &result);
+	if (opt < 0)
+		return ctx->sloppy ? 1 : opt;
+
+	switch (opt) {
+	case Opt_source:
+		if (fc->source)
+			return nfs_invalf(fc, "NFS: Multiple sources not supported");
+		fc->source = param->string;
+		param->string = NULL;
+		break;
+
+		/*
+		 * boolean options:  foo/nofoo
+		 */
+	case Opt_soft:
+		ctx->flags |= NFS_MOUNT_SOFT;
+		ctx->flags &= ~NFS_MOUNT_SOFTERR;
+		break;
+	case Opt_softerr:
+		ctx->flags |= NFS_MOUNT_SOFTERR | NFS_MOUNT_SOFTREVAL;
+		ctx->flags &= ~NFS_MOUNT_SOFT;
+		break;
+	case Opt_hard:
+		ctx->flags &= ~(NFS_MOUNT_SOFT |
+				NFS_MOUNT_SOFTERR |
+				NFS_MOUNT_SOFTREVAL);
+		break;
+	case Opt_softreval:
+		if (result.negated)
+			ctx->flags &= ~NFS_MOUNT_SOFTREVAL;
+		else
+			ctx->flags |= NFS_MOUNT_SOFTREVAL;
+		break;
+	case Opt_posix:
+		if (result.negated)
+			ctx->flags &= ~NFS_MOUNT_POSIX;
+		else
+			ctx->flags |= NFS_MOUNT_POSIX;
+		break;
+	case Opt_cto:
+		if (result.negated)
+			ctx->flags |= NFS_MOUNT_NOCTO;
+		else
+			ctx->flags &= ~NFS_MOUNT_NOCTO;
+		break;
+	case Opt_ac:
+		if (result.negated)
+			ctx->flags |= NFS_MOUNT_NOAC;
+		else
+			ctx->flags &= ~NFS_MOUNT_NOAC;
+		break;
+	case Opt_lock:
+		if (result.negated) {
+			ctx->flags |= NFS_MOUNT_NONLM;
+			ctx->flags |= (NFS_MOUNT_LOCAL_FLOCK | NFS_MOUNT_LOCAL_FCNTL);
+		} else {
+			ctx->flags &= ~NFS_MOUNT_NONLM;
+			ctx->flags &= ~(NFS_MOUNT_LOCAL_FLOCK | NFS_MOUNT_LOCAL_FCNTL);
+		}
+		break;
+	case Opt_udp:
+		ctx->flags &= ~NFS_MOUNT_TCP;
+		ctx->nfs_server.protocol = XPRT_TRANSPORT_UDP;
+		break;
+	case Opt_tcp:
+		ctx->flags |= NFS_MOUNT_TCP;
+		ctx->nfs_server.protocol = XPRT_TRANSPORT_TCP;
+		break;
+	case Opt_rdma:
+		ctx->flags |= NFS_MOUNT_TCP; /* for side protocols */
+		ctx->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
+		xprt_load_transport(param->key);
+		break;
+	case Opt_acl:
+		if (result.negated)
+			ctx->flags |= NFS_MOUNT_NOACL;
+		else
+			ctx->flags &= ~NFS_MOUNT_NOACL;
+		break;
+	case Opt_rdirplus:
+		if (result.negated)
+			ctx->flags |= NFS_MOUNT_NORDIRPLUS;
+		else
+			ctx->flags &= ~NFS_MOUNT_NORDIRPLUS;
+		break;
+	case Opt_sharecache:
+		if (result.negated)
+			ctx->flags |= NFS_MOUNT_UNSHARED;
+		else
+			ctx->flags &= ~NFS_MOUNT_UNSHARED;
+		break;
+	case Opt_resvport:
+		if (result.negated)
+			ctx->flags |= NFS_MOUNT_NORESVPORT;
+		else
+			ctx->flags &= ~NFS_MOUNT_NORESVPORT;
+		break;
+	case Opt_fscache_flag:
+		if (result.negated)
+			ctx->options &= ~NFS_OPTION_FSCACHE;
+		else
+			ctx->options |= NFS_OPTION_FSCACHE;
+		kfree(ctx->fscache_uniq);
+		ctx->fscache_uniq = NULL;
+		break;
+	case Opt_fscache:
+		ctx->options |= NFS_OPTION_FSCACHE;
+		kfree(ctx->fscache_uniq);
+		ctx->fscache_uniq = param->string;
+		param->string = NULL;
+		break;
+	case Opt_migration:
+		if (result.negated)
+			ctx->options &= ~NFS_OPTION_MIGRATION;
+		else
+			ctx->options |= NFS_OPTION_MIGRATION;
+		break;
+
+		/*
+		 * options that take numeric values
+		 */
+	case Opt_port:
+		if (result.uint_32 > USHRT_MAX)
+			goto out_of_bounds;
+		ctx->nfs_server.port = result.uint_32;
+		break;
+	case Opt_rsize:
+		ctx->rsize = result.uint_32;
+		break;
+	case Opt_wsize:
+		ctx->wsize = result.uint_32;
+		break;
+	case Opt_bsize:
+		ctx->bsize = result.uint_32;
+		break;
+	case Opt_timeo:
+		if (result.uint_32 < 1 || result.uint_32 > INT_MAX)
+			goto out_of_bounds;
+		ctx->timeo = result.uint_32;
+		break;
+	case Opt_retrans:
+		if (result.uint_32 > INT_MAX)
+			goto out_of_bounds;
+		ctx->retrans = result.uint_32;
+		break;
+	case Opt_acregmin:
+		ctx->acregmin = result.uint_32;
+		break;
+	case Opt_acregmax:
+		ctx->acregmax = result.uint_32;
+		break;
+	case Opt_acdirmin:
+		ctx->acdirmin = result.uint_32;
+		break;
+	case Opt_acdirmax:
+		ctx->acdirmax = result.uint_32;
+		break;
+	case Opt_actimeo:
+		ctx->acregmin = result.uint_32;
+		ctx->acregmax = result.uint_32;
+		ctx->acdirmin = result.uint_32;
+		ctx->acdirmax = result.uint_32;
+		break;
+	case Opt_namelen:
+		ctx->namlen = result.uint_32;
+		break;
+	case Opt_mountport:
+		if (result.uint_32 > USHRT_MAX)
+			goto out_of_bounds;
+		ctx->mount_server.port = result.uint_32;
+		break;
+	case Opt_mountvers:
+		if (result.uint_32 < NFS_MNT_VERSION ||
+		    result.uint_32 > NFS_MNT3_VERSION)
+			goto out_of_bounds;
+		ctx->mount_server.version = result.uint_32;
+		break;
+	case Opt_minorversion:
+		if (result.uint_32 > NFS4_MAX_MINOR_VERSION)
+			goto out_of_bounds;
+		ctx->minorversion = result.uint_32;
+		break;
+
+		/*
+		 * options that take text values
+		 */
+	case Opt_v:
+		ret = nfs_parse_version_string(fc, param->key + 1);
+		if (ret < 0)
+			return ret;
+		break;
+	case Opt_vers:
+		ret = nfs_parse_version_string(fc, param->string);
+		if (ret < 0)
+			return ret;
+		break;
+	case Opt_sec:
+		ret = nfs_parse_security_flavors(fc, param);
+		if (ret < 0)
+			return ret;
+		break;
+
+	case Opt_proto:
+		protofamily = AF_INET;
+		switch (lookup_constant(nfs_xprt_protocol_tokens, param->string, -1)) {
+		case Opt_xprt_udp6:
+			protofamily = AF_INET6;
+			fallthrough;
+		case Opt_xprt_udp:
+			ctx->flags &= ~NFS_MOUNT_TCP;
+			ctx->nfs_server.protocol = XPRT_TRANSPORT_UDP;
+			break;
+		case Opt_xprt_tcp6:
+			protofamily = AF_INET6;
+			fallthrough;
+		case Opt_xprt_tcp:
+			ctx->flags |= NFS_MOUNT_TCP;
+			ctx->nfs_server.protocol = XPRT_TRANSPORT_TCP;
+			break;
+		case Opt_xprt_rdma6:
+			protofamily = AF_INET6;
+			fallthrough;
+		case Opt_xprt_rdma:
+			/* vector side protocols to TCP */
+			ctx->flags |= NFS_MOUNT_TCP;
+			ctx->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
+			xprt_load_transport(param->string);
+			break;
+		default:
+			return nfs_invalf(fc, "NFS: Unrecognized transport protocol");
+		}
+
+		ctx->protofamily = protofamily;
+		break;
+
+	case Opt_mountproto:
+		mountfamily = AF_INET;
+		switch (lookup_constant(nfs_xprt_protocol_tokens, param->string, -1)) {
+		case Opt_xprt_udp6:
+			mountfamily = AF_INET6;
+			fallthrough;
+		case Opt_xprt_udp:
+			ctx->mount_server.protocol = XPRT_TRANSPORT_UDP;
+			break;
+		case Opt_xprt_tcp6:
+			mountfamily = AF_INET6;
+			fallthrough;
+		case Opt_xprt_tcp:
+			ctx->mount_server.protocol = XPRT_TRANSPORT_TCP;
+			break;
+		case Opt_xprt_rdma: /* not used for side protocols */
+		default:
+			return nfs_invalf(fc, "NFS: Unrecognized transport protocol");
+		}
+		ctx->mountfamily = mountfamily;
+		break;
+
+	case Opt_addr:
+		len = rpc_pton(fc->net_ns, param->string, param->size,
+			       &ctx->nfs_server.address,
+			       sizeof(ctx->nfs_server._address));
+		if (len == 0)
+			goto out_invalid_address;
+		ctx->nfs_server.addrlen = len;
+		break;
+	case Opt_clientaddr:
+		kfree(ctx->client_address);
+		ctx->client_address = param->string;
+		param->string = NULL;
+		break;
+	case Opt_mounthost:
+		kfree(ctx->mount_server.hostname);
+		ctx->mount_server.hostname = param->string;
+		param->string = NULL;
+		break;
+	case Opt_mountaddr:
+		len = rpc_pton(fc->net_ns, param->string, param->size,
+			       &ctx->mount_server.address,
+			       sizeof(ctx->mount_server._address));
+		if (len == 0)
+			goto out_invalid_address;
+		ctx->mount_server.addrlen = len;
+		break;
+	case Opt_nconnect:
+		if (result.uint_32 < 1 || result.uint_32 > NFS_MAX_CONNECTIONS)
+			goto out_of_bounds;
+		ctx->nfs_server.nconnect = result.uint_32;
+		break;
+	case Opt_lookupcache:
+		switch (result.uint_32) {
+		case Opt_lookupcache_all:
+			ctx->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE);
+			break;
+		case Opt_lookupcache_positive:
+			ctx->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE;
+			ctx->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG;
+			break;
+		case Opt_lookupcache_none:
+			ctx->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
+			break;
+		default:
+			goto out_invalid_value;
+		}
+		break;
+	case Opt_local_lock:
+		switch (result.uint_32) {
+		case Opt_local_lock_all:
+			ctx->flags |= (NFS_MOUNT_LOCAL_FLOCK |
+				       NFS_MOUNT_LOCAL_FCNTL);
+			break;
+		case Opt_local_lock_flock:
+			ctx->flags |= NFS_MOUNT_LOCAL_FLOCK;
+			break;
+		case Opt_local_lock_posix:
+			ctx->flags |= NFS_MOUNT_LOCAL_FCNTL;
+			break;
+		case Opt_local_lock_none:
+			ctx->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
+					NFS_MOUNT_LOCAL_FCNTL);
+			break;
+		default:
+			goto out_invalid_value;
+		}
+		break;
+
+		/*
+		 * Special options
+		 */
+	case Opt_sloppy:
+		ctx->sloppy = true;
+		dfprintk(MOUNT, "NFS:   relaxing parsing rules\n");
+		break;
+	}
+
+	return 0;
+
+out_invalid_value:
+	return nfs_invalf(fc, "NFS: Bad mount option value specified");
+out_invalid_address:
+	return nfs_invalf(fc, "NFS: Bad IP address specified");
+out_of_bounds:
+	return nfs_invalf(fc, "NFS: Value for '%s' out of range", param->key);
+}
+
+/*
+ * Split fc->source into "hostname:export_path".
+ *
+ * The leftmost colon demarks the split between the server's hostname
+ * and the export path.  If the hostname starts with a left square
+ * bracket, then it may contain colons.
+ *
+ * Note: caller frees hostname and export path, even on error.
+ */
+static int nfs_parse_source(struct fs_context *fc,
+			    size_t maxnamlen, size_t maxpathlen)
+{
+	struct nfs_fs_context *ctx = nfs_fc2context(fc);
+	const char *dev_name = fc->source;
+	size_t len;
+	const char *end;
+
+	if (unlikely(!dev_name || !*dev_name)) {
+		dfprintk(MOUNT, "NFS: device name not specified\n");
+		return -EINVAL;
+	}
+
+	/* Is the host name protected with square brakcets? */
+	if (*dev_name == '[') {
+		end = strchr(++dev_name, ']');
+		if (end == NULL || end[1] != ':')
+			goto out_bad_devname;
+
+		len = end - dev_name;
+		end++;
+	} else {
+		const char *comma;
+
+		end = strchr(dev_name, ':');
+		if (end == NULL)
+			goto out_bad_devname;
+		len = end - dev_name;
+
+		/* kill possible hostname list: not supported */
+		comma = memchr(dev_name, ',', len);
+		if (comma)
+			len = comma - dev_name;
+	}
+
+	if (len > maxnamlen)
+		goto out_hostname;
+
+	kfree(ctx->nfs_server.hostname);
+
+	/* N.B. caller will free nfs_server.hostname in all cases */
+	ctx->nfs_server.hostname = kmemdup_nul(dev_name, len, GFP_KERNEL);
+	if (!ctx->nfs_server.hostname)
+		goto out_nomem;
+	len = strlen(++end);
+	if (len > maxpathlen)
+		goto out_path;
+	ctx->nfs_server.export_path = kmemdup_nul(end, len, GFP_KERNEL);
+	if (!ctx->nfs_server.export_path)
+		goto out_nomem;
+
+	dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", ctx->nfs_server.export_path);
+	return 0;
+
+out_bad_devname:
+	return nfs_invalf(fc, "NFS: device name not in host:path format");
+out_nomem:
+	nfs_errorf(fc, "NFS: not enough memory to parse device name");
+	return -ENOMEM;
+out_hostname:
+	nfs_errorf(fc, "NFS: server hostname too long");
+	return -ENAMETOOLONG;
+out_path:
+	nfs_errorf(fc, "NFS: export pathname too long");
+	return -ENAMETOOLONG;
+}
+
+static inline bool is_remount_fc(struct fs_context *fc)
+{
+	return fc->root != NULL;
+}
+
+/*
+ * Parse monolithic NFS2/NFS3 mount data
+ * - fills in the mount root filehandle
+ *
+ * For option strings, user space handles the following behaviors:
+ *
+ * + DNS: mapping server host name to IP address ("addr=" option)
+ *
+ * + failure mode: how to behave if a mount request can't be handled
+ *   immediately ("fg/bg" option)
+ *
+ * + retry: how often to retry a mount request ("retry=" option)
+ *
+ * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
+ *   mountproto=tcp after mountproto=udp, and so on
+ */
+static int nfs23_parse_monolithic(struct fs_context *fc,
+				  struct nfs_mount_data *data)
+{
+	struct nfs_fs_context *ctx = nfs_fc2context(fc);
+	struct nfs_fh *mntfh = ctx->mntfh;
+	struct sockaddr *sap = (struct sockaddr *)&ctx->nfs_server.address;
+	int extra_flags = NFS_MOUNT_LEGACY_INTERFACE;
+
+	if (data == NULL)
+		goto out_no_data;
+
+	ctx->version = NFS_DEFAULT_VERSION;
+	switch (data->version) {
+	case 1:
+		data->namlen = 0;
+		fallthrough;
+	case 2:
+		data->bsize = 0;
+		fallthrough;
+	case 3:
+		if (data->flags & NFS_MOUNT_VER3)
+			goto out_no_v3;
+		data->root.size = NFS2_FHSIZE;
+		memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
+		/* Turn off security negotiation */
+		extra_flags |= NFS_MOUNT_SECFLAVOUR;
+		fallthrough;
+	case 4:
+		if (data->flags & NFS_MOUNT_SECFLAVOUR)
+			goto out_no_sec;
+		fallthrough;
+	case 5:
+		memset(data->context, 0, sizeof(data->context));
+		fallthrough;
+	case 6:
+		if (data->flags & NFS_MOUNT_VER3) {
+			if (data->root.size > NFS3_FHSIZE || data->root.size == 0)
+				goto out_invalid_fh;
+			mntfh->size = data->root.size;
+			ctx->version = 3;
+		} else {
+			mntfh->size = NFS2_FHSIZE;
+			ctx->version = 2;
+		}
+
+
+		memcpy(mntfh->data, data->root.data, mntfh->size);
+		if (mntfh->size < sizeof(mntfh->data))
+			memset(mntfh->data + mntfh->size, 0,
+			       sizeof(mntfh->data) - mntfh->size);
+
+		/*
+		 * for proto == XPRT_TRANSPORT_UDP, which is what uses
+		 * to_exponential, implying shift: limit the shift value
+		 * to BITS_PER_LONG (majortimeo is unsigned long)
+		 */
+		if (!(data->flags & NFS_MOUNT_TCP)) /* this will be UDP */
+			if (data->retrans >= 64) /* shift value is too large */
+				goto out_invalid_data;
+
+		/*
+		 * Translate to nfs_fs_context, which nfs_fill_super
+		 * can deal with.
+		 */
+		ctx->flags	= data->flags & NFS_MOUNT_FLAGMASK;
+		ctx->flags	|= extra_flags;
+		ctx->rsize	= data->rsize;
+		ctx->wsize	= data->wsize;
+		ctx->timeo	= data->timeo;
+		ctx->retrans	= data->retrans;
+		ctx->acregmin	= data->acregmin;
+		ctx->acregmax	= data->acregmax;
+		ctx->acdirmin	= data->acdirmin;
+		ctx->acdirmax	= data->acdirmax;
+		ctx->need_mount	= false;
+
+		memcpy(sap, &data->addr, sizeof(data->addr));
+		ctx->nfs_server.addrlen = sizeof(data->addr);
+		ctx->nfs_server.port = ntohs(data->addr.sin_port);
+		if (sap->sa_family != AF_INET ||
+		    !nfs_verify_server_address(sap))
+			goto out_no_address;
+
+		if (!(data->flags & NFS_MOUNT_TCP))
+			ctx->nfs_server.protocol = XPRT_TRANSPORT_UDP;
+		/* N.B. caller will free nfs_server.hostname in all cases */
+		ctx->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
+		if (!ctx->nfs_server.hostname)
+			goto out_nomem;
+
+		ctx->namlen		= data->namlen;
+		ctx->bsize		= data->bsize;
+
+		if (data->flags & NFS_MOUNT_SECFLAVOUR)
+			ctx->selected_flavor = data->pseudoflavor;
+		else
+			ctx->selected_flavor = RPC_AUTH_UNIX;
+
+		if (!(data->flags & NFS_MOUNT_NONLM))
+			ctx->flags &= ~(NFS_MOUNT_LOCAL_FLOCK|
+					 NFS_MOUNT_LOCAL_FCNTL);
+		else
+			ctx->flags |= (NFS_MOUNT_LOCAL_FLOCK|
+					NFS_MOUNT_LOCAL_FCNTL);
+
+		/*
+		 * The legacy version 6 binary mount data from userspace has a
+		 * field used only to transport selinux information into the
+		 * kernel.  To continue to support that functionality we
+		 * have a touch of selinux knowledge here in the NFS code. The
+		 * userspace code converted context=blah to just blah so we are
+		 * converting back to the full string selinux understands.
+		 */
+		if (data->context[0]){
+#ifdef CONFIG_SECURITY_SELINUX
+			int ret;
+
+			data->context[NFS_MAX_CONTEXT_LEN] = '\0';
+			ret = vfs_parse_fs_string(fc, "context",
+						  data->context, strlen(data->context));
+			if (ret < 0)
+				return ret;
+#else
+			return -EINVAL;
+#endif
+		}
+
+		break;
+	default:
+		goto generic;
+	}
+
+	ctx->skip_reconfig_option_check = true;
+	return 0;
+
+generic:
+	return generic_parse_monolithic(fc, data);
+
+out_no_data:
+	if (is_remount_fc(fc)) {
+		ctx->skip_reconfig_option_check = true;
+		return 0;
+	}
+	return nfs_invalf(fc, "NFS: mount program didn't pass any mount data");
+
+out_no_v3:
+	return nfs_invalf(fc, "NFS: nfs_mount_data version does not support v3");
+
+out_no_sec:
+	return nfs_invalf(fc, "NFS: nfs_mount_data version supports only AUTH_SYS");
+
+out_nomem:
+	dfprintk(MOUNT, "NFS: not enough memory to handle mount options");
+	return -ENOMEM;
+
+out_no_address:
+	return nfs_invalf(fc, "NFS: mount program didn't pass remote address");
+
+out_invalid_fh:
+	return nfs_invalf(fc, "NFS: invalid root filehandle");
+
+out_invalid_data:
+	return nfs_invalf(fc, "NFS: invalid binary mount data");
+}
+
+#if IS_ENABLED(CONFIG_NFS_V4)
+struct compat_nfs_string {
+	compat_uint_t len;
+	compat_uptr_t data;
+};
+
+static inline void compat_nfs_string(struct nfs_string *dst,
+				     struct compat_nfs_string *src)
+{
+	dst->data = compat_ptr(src->data);
+	dst->len = src->len;
+}
+
+struct compat_nfs4_mount_data_v1 {
+	compat_int_t version;
+	compat_int_t flags;
+	compat_int_t rsize;
+	compat_int_t wsize;
+	compat_int_t timeo;
+	compat_int_t retrans;
+	compat_int_t acregmin;
+	compat_int_t acregmax;
+	compat_int_t acdirmin;
+	compat_int_t acdirmax;
+	struct compat_nfs_string client_addr;
+	struct compat_nfs_string mnt_path;
+	struct compat_nfs_string hostname;
+	compat_uint_t host_addrlen;
+	compat_uptr_t host_addr;
+	compat_int_t proto;
+	compat_int_t auth_flavourlen;
+	compat_uptr_t auth_flavours;
+};
+
+static void nfs4_compat_mount_data_conv(struct nfs4_mount_data *data)
+{
+	struct compat_nfs4_mount_data_v1 *compat =
+			(struct compat_nfs4_mount_data_v1 *)data;
+
+	/* copy the fields backwards */
+	data->auth_flavours = compat_ptr(compat->auth_flavours);
+	data->auth_flavourlen = compat->auth_flavourlen;
+	data->proto = compat->proto;
+	data->host_addr = compat_ptr(compat->host_addr);
+	data->host_addrlen = compat->host_addrlen;
+	compat_nfs_string(&data->hostname, &compat->hostname);
+	compat_nfs_string(&data->mnt_path, &compat->mnt_path);
+	compat_nfs_string(&data->client_addr, &compat->client_addr);
+	data->acdirmax = compat->acdirmax;
+	data->acdirmin = compat->acdirmin;
+	data->acregmax = compat->acregmax;
+	data->acregmin = compat->acregmin;
+	data->retrans = compat->retrans;
+	data->timeo = compat->timeo;
+	data->wsize = compat->wsize;
+	data->rsize = compat->rsize;
+	data->flags = compat->flags;
+	data->version = compat->version;
+}
+
+/*
+ * Validate NFSv4 mount options
+ */
+static int nfs4_parse_monolithic(struct fs_context *fc,
+				 struct nfs4_mount_data *data)
+{
+	struct nfs_fs_context *ctx = nfs_fc2context(fc);
+	struct sockaddr *sap = (struct sockaddr *)&ctx->nfs_server.address;
+	char *c;
+
+	if (!data) {
+		if (is_remount_fc(fc))
+			goto done;
+		return nfs_invalf(fc,
+			"NFS4: mount program didn't pass any mount data");
+	}
+
+	ctx->version = 4;
+
+	if (data->version != 1)
+		return generic_parse_monolithic(fc, data);
+
+	if (in_compat_syscall())
+		nfs4_compat_mount_data_conv(data);
+
+	if (data->host_addrlen > sizeof(ctx->nfs_server.address))
+		goto out_no_address;
+	if (data->host_addrlen == 0)
+		goto out_no_address;
+	ctx->nfs_server.addrlen = data->host_addrlen;
+	if (copy_from_user(sap, data->host_addr, data->host_addrlen))
+		return -EFAULT;
+	if (!nfs_verify_server_address(sap))
+		goto out_no_address;
+	ctx->nfs_server.port = ntohs(((struct sockaddr_in *)sap)->sin_port);
+
+	if (data->auth_flavourlen) {
+		rpc_authflavor_t pseudoflavor;
+
+		if (data->auth_flavourlen > 1)
+			goto out_inval_auth;
+		if (copy_from_user(&pseudoflavor, data->auth_flavours,
+				   sizeof(pseudoflavor)))
+			return -EFAULT;
+		ctx->selected_flavor = pseudoflavor;
+	} else {
+		ctx->selected_flavor = RPC_AUTH_UNIX;
+	}
+
+	c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
+	if (IS_ERR(c))
+		return PTR_ERR(c);
+	ctx->nfs_server.hostname = c;
+
+	c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
+	if (IS_ERR(c))
+		return PTR_ERR(c);
+	ctx->nfs_server.export_path = c;
+	dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c);
+
+	c = strndup_user(data->client_addr.data, 16);
+	if (IS_ERR(c))
+		return PTR_ERR(c);
+	ctx->client_address = c;
+
+	/*
+	 * Translate to nfs_fs_context, which nfs_fill_super
+	 * can deal with.
+	 */
+
+	ctx->flags	= data->flags & NFS4_MOUNT_FLAGMASK;
+	ctx->rsize	= data->rsize;
+	ctx->wsize	= data->wsize;
+	ctx->timeo	= data->timeo;
+	ctx->retrans	= data->retrans;
+	ctx->acregmin	= data->acregmin;
+	ctx->acregmax	= data->acregmax;
+	ctx->acdirmin	= data->acdirmin;
+	ctx->acdirmax	= data->acdirmax;
+	ctx->nfs_server.protocol = data->proto;
+	nfs_validate_transport_protocol(ctx);
+	if (ctx->nfs_server.protocol == XPRT_TRANSPORT_UDP)
+		goto out_invalid_transport_udp;
+done:
+	ctx->skip_reconfig_option_check = true;
+	return 0;
+
+out_inval_auth:
+	return nfs_invalf(fc, "NFS4: Invalid number of RPC auth flavours %d",
+		      data->auth_flavourlen);
+
+out_no_address:
+	return nfs_invalf(fc, "NFS4: mount program didn't pass remote address");
+
+out_invalid_transport_udp:
+	return nfs_invalf(fc, "NFS: Unsupported transport protocol udp");
+}
+#endif
+
+/*
+ * Parse a monolithic block of data from sys_mount().
+ */
+static int nfs_fs_context_parse_monolithic(struct fs_context *fc,
+					   void *data)
+{
+	if (fc->fs_type == &nfs_fs_type)
+		return nfs23_parse_monolithic(fc, data);
+
+#if IS_ENABLED(CONFIG_NFS_V4)
+	if (fc->fs_type == &nfs4_fs_type)
+		return nfs4_parse_monolithic(fc, data);
+#endif
+
+	return nfs_invalf(fc, "NFS: Unsupported monolithic data version");
+}
+
+/*
+ * Validate the preparsed information in the config.
+ */
+static int nfs_fs_context_validate(struct fs_context *fc)
+{
+	struct nfs_fs_context *ctx = nfs_fc2context(fc);
+	struct nfs_subversion *nfs_mod;
+	struct sockaddr *sap = (struct sockaddr *)&ctx->nfs_server.address;
+	int max_namelen = PAGE_SIZE;
+	int max_pathlen = NFS_MAXPATHLEN;
+	int port = 0;
+	int ret;
+
+	if (!fc->source)
+		goto out_no_device_name;
+
+	/* Check for sanity first. */
+	if (ctx->minorversion && ctx->version != 4)
+		goto out_minorversion_mismatch;
+
+	if (ctx->options & NFS_OPTION_MIGRATION &&
+	    (ctx->version != 4 || ctx->minorversion != 0))
+		goto out_migration_misuse;
+
+	/* Verify that any proto=/mountproto= options match the address
+	 * families in the addr=/mountaddr= options.
+	 */
+	if (ctx->protofamily != AF_UNSPEC &&
+	    ctx->protofamily != ctx->nfs_server.address.sa_family)
+		goto out_proto_mismatch;
+
+	if (ctx->mountfamily != AF_UNSPEC) {
+		if (ctx->mount_server.addrlen) {
+			if (ctx->mountfamily != ctx->mount_server.address.sa_family)
+				goto out_mountproto_mismatch;
+		} else {
+			if (ctx->mountfamily != ctx->nfs_server.address.sa_family)
+				goto out_mountproto_mismatch;
+		}
+	}
+
+	if (!nfs_verify_server_address(sap))
+		goto out_no_address;
+
+	if (ctx->version == 4) {
+		if (IS_ENABLED(CONFIG_NFS_V4)) {
+			if (ctx->nfs_server.protocol == XPRT_TRANSPORT_RDMA)
+				port = NFS_RDMA_PORT;
+			else
+				port = NFS_PORT;
+			max_namelen = NFS4_MAXNAMLEN;
+			max_pathlen = NFS4_MAXPATHLEN;
+			nfs_validate_transport_protocol(ctx);
+			if (ctx->nfs_server.protocol == XPRT_TRANSPORT_UDP)
+				goto out_invalid_transport_udp;
+			ctx->flags &= ~(NFS_MOUNT_NONLM | NFS_MOUNT_NOACL |
+					NFS_MOUNT_VER3 | NFS_MOUNT_LOCAL_FLOCK |
+					NFS_MOUNT_LOCAL_FCNTL);
+		} else {
+			goto out_v4_not_compiled;
+		}
+	} else {
+		nfs_set_mount_transport_protocol(ctx);
+#ifdef CONFIG_NFS_DISABLE_UDP_SUPPORT
+	       if (ctx->nfs_server.protocol == XPRT_TRANSPORT_UDP)
+		       goto out_invalid_transport_udp;
+#endif
+		if (ctx->nfs_server.protocol == XPRT_TRANSPORT_RDMA)
+			port = NFS_RDMA_PORT;
+	}
+
+	nfs_set_port(sap, &ctx->nfs_server.port, port);
+
+	ret = nfs_parse_source(fc, max_namelen, max_pathlen);
+	if (ret < 0)
+		return ret;
+
+	/* Load the NFS protocol module if we haven't done so yet */
+	if (!ctx->nfs_mod) {
+		nfs_mod = get_nfs_version(ctx->version);
+		if (IS_ERR(nfs_mod)) {
+			ret = PTR_ERR(nfs_mod);
+			goto out_version_unavailable;
+		}
+		ctx->nfs_mod = nfs_mod;
+	}
+
+	/* Ensure the filesystem context has the correct fs_type */
+	if (fc->fs_type != ctx->nfs_mod->nfs_fs) {
+		module_put(fc->fs_type->owner);
+		__module_get(ctx->nfs_mod->nfs_fs->owner);
+		fc->fs_type = ctx->nfs_mod->nfs_fs;
+	}
+	return 0;
+
+out_no_device_name:
+	return nfs_invalf(fc, "NFS: Device name not specified");
+out_v4_not_compiled:
+	nfs_errorf(fc, "NFS: NFSv4 is not compiled into kernel");
+	return -EPROTONOSUPPORT;
+out_invalid_transport_udp:
+	return nfs_invalf(fc, "NFS: Unsupported transport protocol udp");
+out_no_address:
+	return nfs_invalf(fc, "NFS: mount program didn't pass remote address");
+out_mountproto_mismatch:
+	return nfs_invalf(fc, "NFS: Mount server address does not match mountproto= option");
+out_proto_mismatch:
+	return nfs_invalf(fc, "NFS: Server address does not match proto= option");
+out_minorversion_mismatch:
+	return nfs_invalf(fc, "NFS: Mount option vers=%u does not support minorversion=%u",
+			  ctx->version, ctx->minorversion);
+out_migration_misuse:
+	return nfs_invalf(fc, "NFS: 'Migration' not supported for this NFS version");
+out_version_unavailable:
+	nfs_errorf(fc, "NFS: Version unavailable");
+	return ret;
+}
+
+/*
+ * Create an NFS superblock by the appropriate method.
+ */
+static int nfs_get_tree(struct fs_context *fc)
+{
+	struct nfs_fs_context *ctx = nfs_fc2context(fc);
+	int err = nfs_fs_context_validate(fc);
+
+	if (err)
+		return err;
+	if (!ctx->internal)
+		return ctx->nfs_mod->rpc_ops->try_get_tree(fc);
+	else
+		return nfs_get_tree_common(fc);
+}
+
+/*
+ * Handle duplication of a configuration.  The caller copied *src into *sc, but
+ * it can't deal with resource pointers in the filesystem context, so we have
+ * to do that.  We need to clear pointers, copy data or get extra refs as
+ * appropriate.
+ */
+static int nfs_fs_context_dup(struct fs_context *fc, struct fs_context *src_fc)
+{
+	struct nfs_fs_context *src = nfs_fc2context(src_fc), *ctx;
+
+	ctx = kmemdup(src, sizeof(struct nfs_fs_context), GFP_KERNEL);
+	if (!ctx)
+		return -ENOMEM;
+
+	ctx->mntfh = nfs_alloc_fhandle();
+	if (!ctx->mntfh) {
+		kfree(ctx);
+		return -ENOMEM;
+	}
+	nfs_copy_fh(ctx->mntfh, src->mntfh);
+
+	__module_get(ctx->nfs_mod->owner);
+	ctx->client_address		= NULL;
+	ctx->mount_server.hostname	= NULL;
+	ctx->nfs_server.export_path	= NULL;
+	ctx->nfs_server.hostname	= NULL;
+	ctx->fscache_uniq		= NULL;
+	ctx->clone_data.fattr		= NULL;
+	fc->fs_private = ctx;
+	return 0;
+}
+
+static void nfs_fs_context_free(struct fs_context *fc)
+{
+	struct nfs_fs_context *ctx = nfs_fc2context(fc);
+
+	if (ctx) {
+		if (ctx->server)
+			nfs_free_server(ctx->server);
+		if (ctx->nfs_mod)
+			put_nfs_version(ctx->nfs_mod);
+		kfree(ctx->client_address);
+		kfree(ctx->mount_server.hostname);
+		kfree(ctx->nfs_server.export_path);
+		kfree(ctx->nfs_server.hostname);
+		kfree(ctx->fscache_uniq);
+		nfs_free_fhandle(ctx->mntfh);
+		nfs_free_fattr(ctx->clone_data.fattr);
+		kfree(ctx);
+	}
+}
+
+static const struct fs_context_operations nfs_fs_context_ops = {
+	.free			= nfs_fs_context_free,
+	.dup			= nfs_fs_context_dup,
+	.parse_param		= nfs_fs_context_parse_param,
+	.parse_monolithic	= nfs_fs_context_parse_monolithic,
+	.get_tree		= nfs_get_tree,
+	.reconfigure		= nfs_reconfigure,
+};
+
+/*
+ * Prepare superblock configuration.  We use the namespaces attached to the
+ * context.  This may be the current process's namespaces, or it may be a
+ * container's namespaces.
+ */
+static int nfs_init_fs_context(struct fs_context *fc)
+{
+	struct nfs_fs_context *ctx;
+
+	ctx = kzalloc(sizeof(struct nfs_fs_context), GFP_KERNEL);
+	if (unlikely(!ctx))
+		return -ENOMEM;
+
+	ctx->mntfh = nfs_alloc_fhandle();
+	if (unlikely(!ctx->mntfh)) {
+		kfree(ctx);
+		return -ENOMEM;
+	}
+
+	ctx->protofamily	= AF_UNSPEC;
+	ctx->mountfamily	= AF_UNSPEC;
+	ctx->mount_server.port	= NFS_UNSPEC_PORT;
+
+	if (fc->root) {
+		/* reconfigure, start with the current config */
+		struct nfs_server *nfss = fc->root->d_sb->s_fs_info;
+		struct net *net = nfss->nfs_client->cl_net;
+
+		ctx->flags		= nfss->flags;
+		ctx->rsize		= nfss->rsize;
+		ctx->wsize		= nfss->wsize;
+		ctx->retrans		= nfss->client->cl_timeout->to_retries;
+		ctx->selected_flavor	= nfss->client->cl_auth->au_flavor;
+		ctx->acregmin		= nfss->acregmin / HZ;
+		ctx->acregmax		= nfss->acregmax / HZ;
+		ctx->acdirmin		= nfss->acdirmin / HZ;
+		ctx->acdirmax		= nfss->acdirmax / HZ;
+		ctx->timeo		= 10U * nfss->client->cl_timeout->to_initval / HZ;
+		ctx->nfs_server.port	= nfss->port;
+		ctx->nfs_server.addrlen	= nfss->nfs_client->cl_addrlen;
+		ctx->version		= nfss->nfs_client->rpc_ops->version;
+		ctx->minorversion	= nfss->nfs_client->cl_minorversion;
+
+		memcpy(&ctx->nfs_server.address, &nfss->nfs_client->cl_addr,
+			ctx->nfs_server.addrlen);
+
+		if (fc->net_ns != net) {
+			put_net(fc->net_ns);
+			fc->net_ns = get_net(net);
+		}
+
+		ctx->nfs_mod = nfss->nfs_client->cl_nfs_mod;
+		__module_get(ctx->nfs_mod->owner);
+	} else {
+		/* defaults */
+		ctx->timeo		= NFS_UNSPEC_TIMEO;
+		ctx->retrans		= NFS_UNSPEC_RETRANS;
+		ctx->acregmin		= NFS_DEF_ACREGMIN;
+		ctx->acregmax		= NFS_DEF_ACREGMAX;
+		ctx->acdirmin		= NFS_DEF_ACDIRMIN;
+		ctx->acdirmax		= NFS_DEF_ACDIRMAX;
+		ctx->nfs_server.port	= NFS_UNSPEC_PORT;
+		ctx->nfs_server.protocol = XPRT_TRANSPORT_TCP;
+		ctx->selected_flavor	= RPC_AUTH_MAXFLAVOR;
+		ctx->minorversion	= 0;
+		ctx->need_mount		= true;
+	}
+	fc->fs_private = ctx;
+	fc->ops = &nfs_fs_context_ops;
+	return 0;
+}
+
+struct file_system_type nfs_fs_type = {
+	.owner			= THIS_MODULE,
+	.name			= "nfs",
+	.init_fs_context	= nfs_init_fs_context,
+	.parameters		= nfs_fs_parameters,
+	.kill_sb		= nfs_kill_super,
+	.fs_flags		= FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
+};
+MODULE_ALIAS_FS("nfs");
+EXPORT_SYMBOL_GPL(nfs_fs_type);
+
+#if IS_ENABLED(CONFIG_NFS_V4)
+struct file_system_type nfs4_fs_type = {
+	.owner			= THIS_MODULE,
+	.name			= "nfs4",
+	.init_fs_context	= nfs_init_fs_context,
+	.parameters		= nfs_fs_parameters,
+	.kill_sb		= nfs_kill_super,
+	.fs_flags		= FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
+};
+MODULE_ALIAS_FS("nfs4");
+MODULE_ALIAS("nfs4");
+EXPORT_SYMBOL_GPL(nfs4_fs_type);
+#endif /* CONFIG_NFS_V4 */
diff --git a/fs/nfs/fscache-index.c b/fs/nfs/fscache-index.c
new file mode 100644
index 000000000..573b1da93
--- /dev/null
+++ b/fs/nfs/fscache-index.c
@@ -0,0 +1,140 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* NFS FS-Cache index structure definition
+ *
+ * Copyright (C) 2008 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <linux/nfs_fs.h>
+#include <linux/nfs_fs_sb.h>
+#include <linux/in6.h>
+#include <linux/iversion.h>
+
+#include "internal.h"
+#include "fscache.h"
+
+#define NFSDBG_FACILITY		NFSDBG_FSCACHE
+
+/*
+ * Define the NFS filesystem for FS-Cache.  Upon registration FS-Cache sticks
+ * the cookie for the top-level index object for NFS into here.  The top-level
+ * index can than have other cache objects inserted into it.
+ */
+struct fscache_netfs nfs_fscache_netfs = {
+	.name		= "nfs",
+	.version	= 0,
+};
+
+/*
+ * Register NFS for caching
+ */
+int nfs_fscache_register(void)
+{
+	return fscache_register_netfs(&nfs_fscache_netfs);
+}
+
+/*
+ * Unregister NFS for caching
+ */
+void nfs_fscache_unregister(void)
+{
+	fscache_unregister_netfs(&nfs_fscache_netfs);
+}
+
+/*
+ * Define the server object for FS-Cache.  This is used to describe a server
+ * object to fscache_acquire_cookie().  It is keyed by the NFS protocol and
+ * server address parameters.
+ */
+const struct fscache_cookie_def nfs_fscache_server_index_def = {
+	.name		= "NFS.server",
+	.type 		= FSCACHE_COOKIE_TYPE_INDEX,
+};
+
+/*
+ * Define the superblock object for FS-Cache.  This is used to describe a
+ * superblock object to fscache_acquire_cookie().  It is keyed by all the NFS
+ * parameters that might cause a separate superblock.
+ */
+const struct fscache_cookie_def nfs_fscache_super_index_def = {
+	.name		= "NFS.super",
+	.type 		= FSCACHE_COOKIE_TYPE_INDEX,
+};
+
+/*
+ * Consult the netfs about the state of an object
+ * - This function can be absent if the index carries no state data
+ * - The netfs data from the cookie being used as the target is
+ *   presented, as is the auxiliary data
+ */
+static
+enum fscache_checkaux nfs_fscache_inode_check_aux(void *cookie_netfs_data,
+						  const void *data,
+						  uint16_t datalen,
+						  loff_t object_size)
+{
+	struct nfs_fscache_inode_auxdata auxdata;
+	struct nfs_inode *nfsi = cookie_netfs_data;
+
+	if (datalen != sizeof(auxdata))
+		return FSCACHE_CHECKAUX_OBSOLETE;
+
+	memset(&auxdata, 0, sizeof(auxdata));
+	auxdata.mtime_sec  = nfsi->vfs_inode.i_mtime.tv_sec;
+	auxdata.mtime_nsec = nfsi->vfs_inode.i_mtime.tv_nsec;
+	auxdata.ctime_sec  = nfsi->vfs_inode.i_ctime.tv_sec;
+	auxdata.ctime_nsec = nfsi->vfs_inode.i_ctime.tv_nsec;
+
+	if (NFS_SERVER(&nfsi->vfs_inode)->nfs_client->rpc_ops->version == 4)
+		auxdata.change_attr = inode_peek_iversion_raw(&nfsi->vfs_inode);
+
+	if (memcmp(data, &auxdata, datalen) != 0)
+		return FSCACHE_CHECKAUX_OBSOLETE;
+
+	return FSCACHE_CHECKAUX_OKAY;
+}
+
+/*
+ * Get an extra reference on a read context.
+ * - This function can be absent if the completion function doesn't require a
+ *   context.
+ * - The read context is passed back to NFS in the event that a data read on the
+ *   cache fails with EIO - in which case the server must be contacted to
+ *   retrieve the data, which requires the read context for security.
+ */
+static void nfs_fh_get_context(void *cookie_netfs_data, void *context)
+{
+	get_nfs_open_context(context);
+}
+
+/*
+ * Release an extra reference on a read context.
+ * - This function can be absent if the completion function doesn't require a
+ *   context.
+ */
+static void nfs_fh_put_context(void *cookie_netfs_data, void *context)
+{
+	if (context)
+		put_nfs_open_context(context);
+}
+
+/*
+ * Define the inode object for FS-Cache.  This is used to describe an inode
+ * object to fscache_acquire_cookie().  It is keyed by the NFS file handle for
+ * an inode.
+ *
+ * Coherency is managed by comparing the copies of i_size, i_mtime and i_ctime
+ * held in the cache auxiliary data for the data storage object with those in
+ * the inode struct in memory.
+ */
+const struct fscache_cookie_def nfs_fscache_inode_object_def = {
+	.name		= "NFS.fh",
+	.type		= FSCACHE_COOKIE_TYPE_DATAFILE,
+	.check_aux	= nfs_fscache_inode_check_aux,
+	.get_context	= nfs_fh_get_context,
+	.put_context	= nfs_fh_put_context,
+};
diff --git a/fs/nfs/fscache.c b/fs/nfs/fscache.c
new file mode 100644
index 000000000..a60df88ef
--- /dev/null
+++ b/fs/nfs/fscache.c
@@ -0,0 +1,516 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* NFS filesystem cache interface
+ *
+ * Copyright (C) 2008 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <linux/nfs_fs.h>
+#include <linux/nfs_fs_sb.h>
+#include <linux/in6.h>
+#include <linux/seq_file.h>
+#include <linux/slab.h>
+#include <linux/iversion.h>
+
+#include "internal.h"
+#include "iostat.h"
+#include "fscache.h"
+
+#define NFSDBG_FACILITY		NFSDBG_FSCACHE
+
+static struct rb_root nfs_fscache_keys = RB_ROOT;
+static DEFINE_SPINLOCK(nfs_fscache_keys_lock);
+
+/*
+ * Layout of the key for an NFS server cache object.
+ */
+struct nfs_server_key {
+	struct {
+		uint16_t	nfsversion;		/* NFS protocol version */
+		uint32_t	minorversion;		/* NFSv4 minor version */
+		uint16_t	family;			/* address family */
+		__be16		port;			/* IP port */
+	} hdr;
+	union {
+		struct in_addr	ipv4_addr;	/* IPv4 address */
+		struct in6_addr ipv6_addr;	/* IPv6 address */
+	};
+} __packed;
+
+/*
+ * Get the per-client index cookie for an NFS client if the appropriate mount
+ * flag was set
+ * - We always try and get an index cookie for the client, but get filehandle
+ *   cookies on a per-superblock basis, depending on the mount flags
+ */
+void nfs_fscache_get_client_cookie(struct nfs_client *clp)
+{
+	const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) &clp->cl_addr;
+	const struct sockaddr_in *sin = (struct sockaddr_in *) &clp->cl_addr;
+	struct nfs_server_key key;
+	uint16_t len = sizeof(key.hdr);
+
+	memset(&key, 0, sizeof(key));
+	key.hdr.nfsversion = clp->rpc_ops->version;
+	key.hdr.minorversion = clp->cl_minorversion;
+	key.hdr.family = clp->cl_addr.ss_family;
+
+	switch (clp->cl_addr.ss_family) {
+	case AF_INET:
+		key.hdr.port = sin->sin_port;
+		key.ipv4_addr = sin->sin_addr;
+		len += sizeof(key.ipv4_addr);
+		break;
+
+	case AF_INET6:
+		key.hdr.port = sin6->sin6_port;
+		key.ipv6_addr = sin6->sin6_addr;
+		len += sizeof(key.ipv6_addr);
+		break;
+
+	default:
+		printk(KERN_WARNING "NFS: Unknown network family '%d'\n",
+		       clp->cl_addr.ss_family);
+		clp->fscache = NULL;
+		return;
+	}
+
+	/* create a cache index for looking up filehandles */
+	clp->fscache = fscache_acquire_cookie(nfs_fscache_netfs.primary_index,
+					      &nfs_fscache_server_index_def,
+					      &key, len,
+					      NULL, 0,
+					      clp, 0, true);
+	dfprintk(FSCACHE, "NFS: get client cookie (0x%p/0x%p)\n",
+		 clp, clp->fscache);
+}
+
+/*
+ * Dispose of a per-client cookie
+ */
+void nfs_fscache_release_client_cookie(struct nfs_client *clp)
+{
+	dfprintk(FSCACHE, "NFS: releasing client cookie (0x%p/0x%p)\n",
+		 clp, clp->fscache);
+
+	fscache_relinquish_cookie(clp->fscache, NULL, false);
+	clp->fscache = NULL;
+}
+
+/*
+ * Get the cache cookie for an NFS superblock.  We have to handle
+ * uniquification here because the cache doesn't do it for us.
+ *
+ * The default uniquifier is just an empty string, but it may be overridden
+ * either by the 'fsc=xxx' option to mount, or by inheriting it from the parent
+ * superblock across an automount point of some nature.
+ */
+void nfs_fscache_get_super_cookie(struct super_block *sb, const char *uniq, int ulen)
+{
+	struct nfs_fscache_key *key, *xkey;
+	struct nfs_server *nfss = NFS_SB(sb);
+	struct rb_node **p, *parent;
+	int diff;
+
+	nfss->fscache_key = NULL;
+	nfss->fscache = NULL;
+	if (!uniq) {
+		uniq = "";
+		ulen = 1;
+	}
+
+	key = kzalloc(sizeof(*key) + ulen, GFP_KERNEL);
+	if (!key)
+		return;
+
+	key->nfs_client = nfss->nfs_client;
+	key->key.super.s_flags = sb->s_flags & NFS_SB_MASK;
+	key->key.nfs_server.flags = nfss->flags;
+	key->key.nfs_server.rsize = nfss->rsize;
+	key->key.nfs_server.wsize = nfss->wsize;
+	key->key.nfs_server.acregmin = nfss->acregmin;
+	key->key.nfs_server.acregmax = nfss->acregmax;
+	key->key.nfs_server.acdirmin = nfss->acdirmin;
+	key->key.nfs_server.acdirmax = nfss->acdirmax;
+	key->key.nfs_server.fsid = nfss->fsid;
+	key->key.rpc_auth.au_flavor = nfss->client->cl_auth->au_flavor;
+
+	key->key.uniq_len = ulen;
+	memcpy(key->key.uniquifier, uniq, ulen);
+
+	spin_lock(&nfs_fscache_keys_lock);
+	p = &nfs_fscache_keys.rb_node;
+	parent = NULL;
+	while (*p) {
+		parent = *p;
+		xkey = rb_entry(parent, struct nfs_fscache_key, node);
+
+		if (key->nfs_client < xkey->nfs_client)
+			goto go_left;
+		if (key->nfs_client > xkey->nfs_client)
+			goto go_right;
+
+		diff = memcmp(&key->key, &xkey->key, sizeof(key->key));
+		if (diff < 0)
+			goto go_left;
+		if (diff > 0)
+			goto go_right;
+
+		if (key->key.uniq_len == 0)
+			goto non_unique;
+		diff = memcmp(key->key.uniquifier,
+			      xkey->key.uniquifier,
+			      key->key.uniq_len);
+		if (diff < 0)
+			goto go_left;
+		if (diff > 0)
+			goto go_right;
+		goto non_unique;
+
+	go_left:
+		p = &(*p)->rb_left;
+		continue;
+	go_right:
+		p = &(*p)->rb_right;
+	}
+
+	rb_link_node(&key->node, parent, p);
+	rb_insert_color(&key->node, &nfs_fscache_keys);
+	spin_unlock(&nfs_fscache_keys_lock);
+	nfss->fscache_key = key;
+
+	/* create a cache index for looking up filehandles */
+	nfss->fscache = fscache_acquire_cookie(nfss->nfs_client->fscache,
+					       &nfs_fscache_super_index_def,
+					       &key->key,
+					       sizeof(key->key) + ulen,
+					       NULL, 0,
+					       nfss, 0, true);
+	dfprintk(FSCACHE, "NFS: get superblock cookie (0x%p/0x%p)\n",
+		 nfss, nfss->fscache);
+	return;
+
+non_unique:
+	spin_unlock(&nfs_fscache_keys_lock);
+	kfree(key);
+	nfss->fscache_key = NULL;
+	nfss->fscache = NULL;
+	printk(KERN_WARNING "NFS:"
+	       " Cache request denied due to non-unique superblock keys\n");
+}
+
+/*
+ * release a per-superblock cookie
+ */
+void nfs_fscache_release_super_cookie(struct super_block *sb)
+{
+	struct nfs_server *nfss = NFS_SB(sb);
+
+	dfprintk(FSCACHE, "NFS: releasing superblock cookie (0x%p/0x%p)\n",
+		 nfss, nfss->fscache);
+
+	fscache_relinquish_cookie(nfss->fscache, NULL, false);
+	nfss->fscache = NULL;
+
+	if (nfss->fscache_key) {
+		spin_lock(&nfs_fscache_keys_lock);
+		rb_erase(&nfss->fscache_key->node, &nfs_fscache_keys);
+		spin_unlock(&nfs_fscache_keys_lock);
+		kfree(nfss->fscache_key);
+		nfss->fscache_key = NULL;
+	}
+}
+
+static void nfs_fscache_update_auxdata(struct nfs_fscache_inode_auxdata *auxdata,
+				  struct nfs_inode *nfsi)
+{
+	memset(auxdata, 0, sizeof(*auxdata));
+	auxdata->mtime_sec  = nfsi->vfs_inode.i_mtime.tv_sec;
+	auxdata->mtime_nsec = nfsi->vfs_inode.i_mtime.tv_nsec;
+	auxdata->ctime_sec  = nfsi->vfs_inode.i_ctime.tv_sec;
+	auxdata->ctime_nsec = nfsi->vfs_inode.i_ctime.tv_nsec;
+
+	if (NFS_SERVER(&nfsi->vfs_inode)->nfs_client->rpc_ops->version == 4)
+		auxdata->change_attr = inode_peek_iversion_raw(&nfsi->vfs_inode);
+}
+
+/*
+ * Initialise the per-inode cache cookie pointer for an NFS inode.
+ */
+void nfs_fscache_init_inode(struct inode *inode)
+{
+	struct nfs_fscache_inode_auxdata auxdata;
+	struct nfs_server *nfss = NFS_SERVER(inode);
+	struct nfs_inode *nfsi = NFS_I(inode);
+
+	nfsi->fscache = NULL;
+	if (!(nfss->fscache && S_ISREG(inode->i_mode)))
+		return;
+
+	nfs_fscache_update_auxdata(&auxdata, nfsi);
+
+	nfsi->fscache = fscache_acquire_cookie(NFS_SB(inode->i_sb)->fscache,
+					       &nfs_fscache_inode_object_def,
+					       nfsi->fh.data, nfsi->fh.size,
+					       &auxdata, sizeof(auxdata),
+					       nfsi, nfsi->vfs_inode.i_size, false);
+}
+
+/*
+ * Release a per-inode cookie.
+ */
+void nfs_fscache_clear_inode(struct inode *inode)
+{
+	struct nfs_fscache_inode_auxdata auxdata;
+	struct nfs_inode *nfsi = NFS_I(inode);
+	struct fscache_cookie *cookie = nfs_i_fscache(inode);
+
+	dfprintk(FSCACHE, "NFS: clear cookie (0x%p/0x%p)\n", nfsi, cookie);
+
+	nfs_fscache_update_auxdata(&auxdata, nfsi);
+	fscache_relinquish_cookie(cookie, &auxdata, false);
+	nfsi->fscache = NULL;
+}
+
+static bool nfs_fscache_can_enable(void *data)
+{
+	struct inode *inode = data;
+
+	return !inode_is_open_for_write(inode);
+}
+
+/*
+ * Enable or disable caching for a file that is being opened as appropriate.
+ * The cookie is allocated when the inode is initialised, but is not enabled at
+ * that time.  Enablement is deferred to file-open time to avoid stat() and
+ * access() thrashing the cache.
+ *
+ * For now, with NFS, only regular files that are open read-only will be able
+ * to use the cache.
+ *
+ * We enable the cache for an inode if we open it read-only and it isn't
+ * currently open for writing.  We disable the cache if the inode is open
+ * write-only.
+ *
+ * The caller uses the file struct to pin i_writecount on the inode before
+ * calling us when a file is opened for writing, so we can make use of that.
+ *
+ * Note that this may be invoked multiple times in parallel by parallel
+ * nfs_open() functions.
+ */
+void nfs_fscache_open_file(struct inode *inode, struct file *filp)
+{
+	struct nfs_fscache_inode_auxdata auxdata;
+	struct nfs_inode *nfsi = NFS_I(inode);
+	struct fscache_cookie *cookie = nfs_i_fscache(inode);
+
+	if (!fscache_cookie_valid(cookie))
+		return;
+
+	nfs_fscache_update_auxdata(&auxdata, nfsi);
+
+	if (inode_is_open_for_write(inode)) {
+		dfprintk(FSCACHE, "NFS: nfsi 0x%p disabling cache\n", nfsi);
+		clear_bit(NFS_INO_FSCACHE, &nfsi->flags);
+		fscache_disable_cookie(cookie, &auxdata, true);
+		fscache_uncache_all_inode_pages(cookie, inode);
+	} else {
+		dfprintk(FSCACHE, "NFS: nfsi 0x%p enabling cache\n", nfsi);
+		fscache_enable_cookie(cookie, &auxdata, nfsi->vfs_inode.i_size,
+				      nfs_fscache_can_enable, inode);
+		if (fscache_cookie_enabled(cookie))
+			set_bit(NFS_INO_FSCACHE, &NFS_I(inode)->flags);
+	}
+}
+EXPORT_SYMBOL_GPL(nfs_fscache_open_file);
+
+/*
+ * Release the caching state associated with a page, if the page isn't busy
+ * interacting with the cache.
+ * - Returns true (can release page) or false (page busy).
+ */
+int nfs_fscache_release_page(struct page *page, gfp_t gfp)
+{
+	if (PageFsCache(page)) {
+		struct fscache_cookie *cookie = nfs_i_fscache(page->mapping->host);
+
+		BUG_ON(!cookie);
+		dfprintk(FSCACHE, "NFS: fscache releasepage (0x%p/0x%p/0x%p)\n",
+			 cookie, page, NFS_I(page->mapping->host));
+
+		if (!fscache_maybe_release_page(cookie, page, gfp))
+			return 0;
+
+		nfs_inc_fscache_stats(page->mapping->host,
+				      NFSIOS_FSCACHE_PAGES_UNCACHED);
+	}
+
+	return 1;
+}
+
+/*
+ * Release the caching state associated with a page if undergoing complete page
+ * invalidation.
+ */
+void __nfs_fscache_invalidate_page(struct page *page, struct inode *inode)
+{
+	struct fscache_cookie *cookie = nfs_i_fscache(inode);
+
+	BUG_ON(!cookie);
+
+	dfprintk(FSCACHE, "NFS: fscache invalidatepage (0x%p/0x%p/0x%p)\n",
+		 cookie, page, NFS_I(inode));
+
+	fscache_wait_on_page_write(cookie, page);
+
+	BUG_ON(!PageLocked(page));
+	fscache_uncache_page(cookie, page);
+	nfs_inc_fscache_stats(page->mapping->host,
+			      NFSIOS_FSCACHE_PAGES_UNCACHED);
+}
+
+/*
+ * Handle completion of a page being read from the cache.
+ * - Called in process (keventd) context.
+ */
+static void nfs_readpage_from_fscache_complete(struct page *page,
+					       void *context,
+					       int error)
+{
+	dfprintk(FSCACHE,
+		 "NFS: readpage_from_fscache_complete (0x%p/0x%p/%d)\n",
+		 page, context, error);
+
+	/* if the read completes with an error, we just unlock the page and let
+	 * the VM reissue the readpage */
+	if (!error) {
+		SetPageUptodate(page);
+		unlock_page(page);
+	} else {
+		error = nfs_readpage_async(context, page->mapping->host, page);
+		if (error)
+			unlock_page(page);
+	}
+}
+
+/*
+ * Retrieve a page from fscache
+ */
+int __nfs_readpage_from_fscache(struct nfs_open_context *ctx,
+				struct inode *inode, struct page *page)
+{
+	int ret;
+
+	dfprintk(FSCACHE,
+		 "NFS: readpage_from_fscache(fsc:%p/p:%p(i:%lx f:%lx)/0x%p)\n",
+		 nfs_i_fscache(inode), page, page->index, page->flags, inode);
+
+	ret = fscache_read_or_alloc_page(nfs_i_fscache(inode),
+					 page,
+					 nfs_readpage_from_fscache_complete,
+					 ctx,
+					 GFP_KERNEL);
+
+	switch (ret) {
+	case 0: /* read BIO submitted (page in fscache) */
+		dfprintk(FSCACHE,
+			 "NFS:    readpage_from_fscache: BIO submitted\n");
+		nfs_inc_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_READ_OK);
+		return ret;
+
+	case -ENOBUFS: /* inode not in cache */
+	case -ENODATA: /* page not in cache */
+		nfs_inc_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_READ_FAIL);
+		dfprintk(FSCACHE,
+			 "NFS:    readpage_from_fscache %d\n", ret);
+		return 1;
+
+	default:
+		dfprintk(FSCACHE, "NFS:    readpage_from_fscache %d\n", ret);
+		nfs_inc_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_READ_FAIL);
+	}
+	return ret;
+}
+
+/*
+ * Retrieve a set of pages from fscache
+ */
+int __nfs_readpages_from_fscache(struct nfs_open_context *ctx,
+				 struct inode *inode,
+				 struct address_space *mapping,
+				 struct list_head *pages,
+				 unsigned *nr_pages)
+{
+	unsigned npages = *nr_pages;
+	int ret;
+
+	dfprintk(FSCACHE, "NFS: nfs_getpages_from_fscache (0x%p/%u/0x%p)\n",
+		 nfs_i_fscache(inode), npages, inode);
+
+	ret = fscache_read_or_alloc_pages(nfs_i_fscache(inode),
+					  mapping, pages, nr_pages,
+					  nfs_readpage_from_fscache_complete,
+					  ctx,
+					  mapping_gfp_mask(mapping));
+	if (*nr_pages < npages)
+		nfs_add_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_READ_OK,
+				      npages);
+	if (*nr_pages > 0)
+		nfs_add_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_READ_FAIL,
+				      *nr_pages);
+
+	switch (ret) {
+	case 0: /* read submitted to the cache for all pages */
+		BUG_ON(!list_empty(pages));
+		BUG_ON(*nr_pages != 0);
+		dfprintk(FSCACHE,
+			 "NFS: nfs_getpages_from_fscache: submitted\n");
+
+		return ret;
+
+	case -ENOBUFS: /* some pages aren't cached and can't be */
+	case -ENODATA: /* some pages aren't cached */
+		dfprintk(FSCACHE,
+			 "NFS: nfs_getpages_from_fscache: no page: %d\n", ret);
+		return 1;
+
+	default:
+		dfprintk(FSCACHE,
+			 "NFS: nfs_getpages_from_fscache: ret  %d\n", ret);
+	}
+
+	return ret;
+}
+
+/*
+ * Store a newly fetched page in fscache
+ * - PG_fscache must be set on the page
+ */
+void __nfs_readpage_to_fscache(struct inode *inode, struct page *page, int sync)
+{
+	int ret;
+
+	dfprintk(FSCACHE,
+		 "NFS: readpage_to_fscache(fsc:%p/p:%p(i:%lx f:%lx)/%d)\n",
+		 nfs_i_fscache(inode), page, page->index, page->flags, sync);
+
+	ret = fscache_write_page(nfs_i_fscache(inode), page,
+				 inode->i_size, GFP_KERNEL);
+	dfprintk(FSCACHE,
+		 "NFS:     readpage_to_fscache: p:%p(i:%lu f:%lx) ret %d\n",
+		 page, page->index, page->flags, ret);
+
+	if (ret != 0) {
+		fscache_uncache_page(nfs_i_fscache(inode), page);
+		nfs_inc_fscache_stats(inode,
+				      NFSIOS_FSCACHE_PAGES_WRITTEN_FAIL);
+		nfs_inc_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_UNCACHED);
+	} else {
+		nfs_inc_fscache_stats(inode,
+				      NFSIOS_FSCACHE_PAGES_WRITTEN_OK);
+	}
+}
diff --git a/fs/nfs/fscache.h b/fs/nfs/fscache.h
new file mode 100644
index 000000000..6754c8607
--- /dev/null
+++ b/fs/nfs/fscache.h
@@ -0,0 +1,242 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/* NFS filesystem cache interface definitions
+ *
+ * Copyright (C) 2008 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#ifndef _NFS_FSCACHE_H
+#define _NFS_FSCACHE_H
+
+#include <linux/nfs_fs.h>
+#include <linux/nfs_mount.h>
+#include <linux/nfs4_mount.h>
+#include <linux/fscache.h>
+
+#ifdef CONFIG_NFS_FSCACHE
+
+/*
+ * set of NFS FS-Cache objects that form a superblock key
+ */
+struct nfs_fscache_key {
+	struct rb_node		node;
+	struct nfs_client	*nfs_client;	/* the server */
+
+	/* the elements of the unique key - as used by nfs_compare_super() and
+	 * nfs_compare_mount_options() to distinguish superblocks */
+	struct {
+		struct {
+			unsigned long	s_flags;	/* various flags
+							 * (& NFS_MS_MASK) */
+		} super;
+
+		struct {
+			struct nfs_fsid fsid;
+			int		flags;
+			unsigned int	rsize;		/* read size */
+			unsigned int	wsize;		/* write size */
+			unsigned int	acregmin;	/* attr cache timeouts */
+			unsigned int	acregmax;
+			unsigned int	acdirmin;
+			unsigned int	acdirmax;
+		} nfs_server;
+
+		struct {
+			rpc_authflavor_t au_flavor;
+		} rpc_auth;
+
+		/* uniquifier - can be used if nfs_server.flags includes
+		 * NFS_MOUNT_UNSHARED  */
+		u8 uniq_len;
+		char uniquifier[0];
+	} key;
+};
+
+/*
+ * Definition of the auxiliary data attached to NFS inode storage objects
+ * within the cache.
+ *
+ * The contents of this struct are recorded in the on-disk local cache in the
+ * auxiliary data attached to the data storage object backing an inode.  This
+ * permits coherency to be managed when a new inode binds to an already extant
+ * cache object.
+ */
+struct nfs_fscache_inode_auxdata {
+	s64	mtime_sec;
+	s64	mtime_nsec;
+	s64	ctime_sec;
+	s64	ctime_nsec;
+	u64	change_attr;
+};
+
+/*
+ * fscache-index.c
+ */
+extern struct fscache_netfs nfs_fscache_netfs;
+extern const struct fscache_cookie_def nfs_fscache_server_index_def;
+extern const struct fscache_cookie_def nfs_fscache_super_index_def;
+extern const struct fscache_cookie_def nfs_fscache_inode_object_def;
+
+extern int nfs_fscache_register(void);
+extern void nfs_fscache_unregister(void);
+
+/*
+ * fscache.c
+ */
+extern void nfs_fscache_get_client_cookie(struct nfs_client *);
+extern void nfs_fscache_release_client_cookie(struct nfs_client *);
+
+extern void nfs_fscache_get_super_cookie(struct super_block *, const char *, int);
+extern void nfs_fscache_release_super_cookie(struct super_block *);
+
+extern void nfs_fscache_init_inode(struct inode *);
+extern void nfs_fscache_clear_inode(struct inode *);
+extern void nfs_fscache_open_file(struct inode *, struct file *);
+
+extern void __nfs_fscache_invalidate_page(struct page *, struct inode *);
+extern int nfs_fscache_release_page(struct page *, gfp_t);
+
+extern int __nfs_readpage_from_fscache(struct nfs_open_context *,
+				       struct inode *, struct page *);
+extern int __nfs_readpages_from_fscache(struct nfs_open_context *,
+					struct inode *, struct address_space *,
+					struct list_head *, unsigned *);
+extern void __nfs_readpage_to_fscache(struct inode *, struct page *, int);
+
+/*
+ * wait for a page to complete writing to the cache
+ */
+static inline void nfs_fscache_wait_on_page_write(struct nfs_inode *nfsi,
+						  struct page *page)
+{
+	if (PageFsCache(page))
+		fscache_wait_on_page_write(nfsi->fscache, page);
+}
+
+/*
+ * release the caching state associated with a page if undergoing complete page
+ * invalidation
+ */
+static inline void nfs_fscache_invalidate_page(struct page *page,
+					       struct inode *inode)
+{
+	if (PageFsCache(page))
+		__nfs_fscache_invalidate_page(page, inode);
+}
+
+/*
+ * Retrieve a page from an inode data storage object.
+ */
+static inline int nfs_readpage_from_fscache(struct nfs_open_context *ctx,
+					    struct inode *inode,
+					    struct page *page)
+{
+	if (NFS_I(inode)->fscache)
+		return __nfs_readpage_from_fscache(ctx, inode, page);
+	return -ENOBUFS;
+}
+
+/*
+ * Retrieve a set of pages from an inode data storage object.
+ */
+static inline int nfs_readpages_from_fscache(struct nfs_open_context *ctx,
+					     struct inode *inode,
+					     struct address_space *mapping,
+					     struct list_head *pages,
+					     unsigned *nr_pages)
+{
+	if (NFS_I(inode)->fscache)
+		return __nfs_readpages_from_fscache(ctx, inode, mapping, pages,
+						    nr_pages);
+	return -ENOBUFS;
+}
+
+/*
+ * Store a page newly fetched from the server in an inode data storage object
+ * in the cache.
+ */
+static inline void nfs_readpage_to_fscache(struct inode *inode,
+					   struct page *page,
+					   int sync)
+{
+	if (PageFsCache(page))
+		__nfs_readpage_to_fscache(inode, page, sync);
+}
+
+/*
+ * Invalidate the contents of fscache for this inode.  This will not sleep.
+ */
+static inline void nfs_fscache_invalidate(struct inode *inode)
+{
+	fscache_invalidate(NFS_I(inode)->fscache);
+}
+
+/*
+ * Wait for an object to finish being invalidated.
+ */
+static inline void nfs_fscache_wait_on_invalidate(struct inode *inode)
+{
+	fscache_wait_on_invalidate(NFS_I(inode)->fscache);
+}
+
+/*
+ * indicate the client caching state as readable text
+ */
+static inline const char *nfs_server_fscache_state(struct nfs_server *server)
+{
+	if (server->fscache)
+		return "yes";
+	return "no ";
+}
+
+#else /* CONFIG_NFS_FSCACHE */
+static inline int nfs_fscache_register(void) { return 0; }
+static inline void nfs_fscache_unregister(void) {}
+
+static inline void nfs_fscache_get_client_cookie(struct nfs_client *clp) {}
+static inline void nfs_fscache_release_client_cookie(struct nfs_client *clp) {}
+
+static inline void nfs_fscache_release_super_cookie(struct super_block *sb) {}
+
+static inline void nfs_fscache_init_inode(struct inode *inode) {}
+static inline void nfs_fscache_clear_inode(struct inode *inode) {}
+static inline void nfs_fscache_open_file(struct inode *inode,
+					 struct file *filp) {}
+
+static inline int nfs_fscache_release_page(struct page *page, gfp_t gfp)
+{
+	return 1; /* True: may release page */
+}
+static inline void nfs_fscache_invalidate_page(struct page *page,
+					       struct inode *inode) {}
+static inline void nfs_fscache_wait_on_page_write(struct nfs_inode *nfsi,
+						  struct page *page) {}
+
+static inline int nfs_readpage_from_fscache(struct nfs_open_context *ctx,
+					    struct inode *inode,
+					    struct page *page)
+{
+	return -ENOBUFS;
+}
+static inline int nfs_readpages_from_fscache(struct nfs_open_context *ctx,
+					     struct inode *inode,
+					     struct address_space *mapping,
+					     struct list_head *pages,
+					     unsigned *nr_pages)
+{
+	return -ENOBUFS;
+}
+static inline void nfs_readpage_to_fscache(struct inode *inode,
+					   struct page *page, int sync) {}
+
+
+static inline void nfs_fscache_invalidate(struct inode *inode) {}
+static inline void nfs_fscache_wait_on_invalidate(struct inode *inode) {}
+
+static inline const char *nfs_server_fscache_state(struct nfs_server *server)
+{
+	return "no ";
+}
+
+#endif /* CONFIG_NFS_FSCACHE */
+#endif /* _NFS_FSCACHE_H */
diff --git a/fs/nfs/getroot.c b/fs/nfs/getroot.c
new file mode 100644
index 000000000..aaeeb4659
--- /dev/null
+++ b/fs/nfs/getroot.c
@@ -0,0 +1,165 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* getroot.c: get the root dentry for an NFS mount
+ *
+ * Copyright (C) 2006 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+
+#include <linux/time.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/string.h>
+#include <linux/stat.h>
+#include <linux/errno.h>
+#include <linux/unistd.h>
+#include <linux/sunrpc/clnt.h>
+#include <linux/sunrpc/stats.h>
+#include <linux/nfs_fs.h>
+#include <linux/nfs_mount.h>
+#include <linux/lockd/bind.h>
+#include <linux/seq_file.h>
+#include <linux/mount.h>
+#include <linux/vfs.h>
+#include <linux/namei.h>
+#include <linux/security.h>
+
+#include <linux/uaccess.h>
+
+#include "internal.h"
+
+#define NFSDBG_FACILITY		NFSDBG_CLIENT
+
+/*
+ * Set the superblock root dentry.
+ * Note that this function frees the inode in case of error.
+ */
+static int nfs_superblock_set_dummy_root(struct super_block *sb, struct inode *inode)
+{
+	/* The mntroot acts as the dummy root dentry for this superblock */
+	if (sb->s_root == NULL) {
+		sb->s_root = d_make_root(inode);
+		if (sb->s_root == NULL)
+			return -ENOMEM;
+		ihold(inode);
+		/*
+		 * Ensure that this dentry is invisible to d_find_alias().
+		 * Otherwise, it may be spliced into the tree by
+		 * d_splice_alias if a parent directory from the same
+		 * filesystem gets mounted at a later time.
+		 * This again causes shrink_dcache_for_umount_subtree() to
+		 * Oops, since the test for IS_ROOT() will fail.
+		 */
+		spin_lock(&d_inode(sb->s_root)->i_lock);
+		spin_lock(&sb->s_root->d_lock);
+		hlist_del_init(&sb->s_root->d_u.d_alias);
+		spin_unlock(&sb->s_root->d_lock);
+		spin_unlock(&d_inode(sb->s_root)->i_lock);
+	}
+	return 0;
+}
+
+/*
+ * get an NFS2/NFS3 root dentry from the root filehandle
+ */
+int nfs_get_root(struct super_block *s, struct fs_context *fc)
+{
+	struct nfs_fs_context *ctx = nfs_fc2context(fc);
+	struct nfs_server *server = NFS_SB(s);
+	struct nfs_fsinfo fsinfo;
+	struct dentry *root;
+	struct inode *inode;
+	char *name;
+	int error = -ENOMEM;
+	unsigned long kflags = 0, kflags_out = 0;
+
+	name = kstrdup(fc->source, GFP_KERNEL);
+	if (!name)
+		goto out;
+
+	/* get the actual root for this mount */
+	fsinfo.fattr = nfs_alloc_fattr();
+	if (fsinfo.fattr == NULL)
+		goto out_name;
+
+	fsinfo.fattr->label = nfs4_label_alloc(server, GFP_KERNEL);
+	if (IS_ERR(fsinfo.fattr->label))
+		goto out_fattr;
+	error = server->nfs_client->rpc_ops->getroot(server, ctx->mntfh, &fsinfo);
+	if (error < 0) {
+		dprintk("nfs_get_root: getattr error = %d\n", -error);
+		nfs_errorf(fc, "NFS: Couldn't getattr on root");
+		goto out_label;
+	}
+
+	inode = nfs_fhget(s, ctx->mntfh, fsinfo.fattr, NULL);
+	if (IS_ERR(inode)) {
+		dprintk("nfs_get_root: get root inode failed\n");
+		error = PTR_ERR(inode);
+		nfs_errorf(fc, "NFS: Couldn't get root inode");
+		goto out_label;
+	}
+
+	error = nfs_superblock_set_dummy_root(s, inode);
+	if (error != 0)
+		goto out_label;
+
+	/* root dentries normally start off anonymous and get spliced in later
+	 * if the dentry tree reaches them; however if the dentry already
+	 * exists, we'll pick it up at this point and use it as the root
+	 */
+	root = d_obtain_root(inode);
+	if (IS_ERR(root)) {
+		dprintk("nfs_get_root: get root dentry failed\n");
+		error = PTR_ERR(root);
+		nfs_errorf(fc, "NFS: Couldn't get root dentry");
+		goto out_label;
+	}
+
+	security_d_instantiate(root, inode);
+	spin_lock(&root->d_lock);
+	if (IS_ROOT(root) && !root->d_fsdata &&
+	    !(root->d_flags & DCACHE_NFSFS_RENAMED)) {
+		root->d_fsdata = name;
+		name = NULL;
+	}
+	spin_unlock(&root->d_lock);
+	fc->root = root;
+	if (NFS_SB(s)->caps & NFS_CAP_SECURITY_LABEL)
+		kflags |= SECURITY_LSM_NATIVE_LABELS;
+	if (ctx->clone_data.sb) {
+		if (d_inode(fc->root)->i_fop != &nfs_dir_operations) {
+			error = -ESTALE;
+			goto error_splat_root;
+		}
+		/* clone lsm security options from the parent to the new sb */
+		error = security_sb_clone_mnt_opts(ctx->clone_data.sb,
+						   s, kflags, &kflags_out);
+	} else {
+		error = security_sb_set_mnt_opts(s, fc->security,
+							kflags, &kflags_out);
+	}
+	if (error)
+		goto error_splat_root;
+	if (NFS_SB(s)->caps & NFS_CAP_SECURITY_LABEL &&
+		!(kflags_out & SECURITY_LSM_NATIVE_LABELS))
+		NFS_SB(s)->caps &= ~NFS_CAP_SECURITY_LABEL;
+
+	nfs_setsecurity(inode, fsinfo.fattr, fsinfo.fattr->label);
+	error = 0;
+
+out_label:
+	nfs4_label_free(fsinfo.fattr->label);
+out_fattr:
+	nfs_free_fattr(fsinfo.fattr);
+out_name:
+	kfree(name);
+out:
+	return error;
+error_splat_root:
+	dput(fc->root);
+	fc->root = NULL;
+	goto out_label;
+}
diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
new file mode 100644
index 000000000..36f415278
--- /dev/null
+++ b/fs/nfs/inode.c
@@ -0,0 +1,2346 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  linux/fs/nfs/inode.c
+ *
+ *  Copyright (C) 1992  Rick Sladkey
+ *
+ *  nfs inode and superblock handling functions
+ *
+ *  Modularised by Alan Cox <alan@lxorguk.ukuu.org.uk>, while hacking some
+ *  experimental NFS changes. Modularisation taken straight from SYS5 fs.
+ *
+ *  Change to nfs_read_super() to permit NFS mounts to multi-homed hosts.
+ *  J.S.Peatfield@damtp.cam.ac.uk
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/sched/signal.h>
+#include <linux/time.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/string.h>
+#include <linux/stat.h>
+#include <linux/errno.h>
+#include <linux/unistd.h>
+#include <linux/sunrpc/clnt.h>
+#include <linux/sunrpc/stats.h>
+#include <linux/sunrpc/metrics.h>
+#include <linux/nfs_fs.h>
+#include <linux/nfs_mount.h>
+#include <linux/nfs4_mount.h>
+#include <linux/lockd/bind.h>
+#include <linux/seq_file.h>
+#include <linux/mount.h>
+#include <linux/vfs.h>
+#include <linux/inet.h>
+#include <linux/nfs_xdr.h>
+#include <linux/slab.h>
+#include <linux/compat.h>
+#include <linux/freezer.h>
+#include <linux/uaccess.h>
+#include <linux/iversion.h>
+
+#include "nfs4_fs.h"
+#include "callback.h"
+#include "delegation.h"
+#include "iostat.h"
+#include "internal.h"
+#include "fscache.h"
+#include "pnfs.h"
+#include "nfs.h"
+#include "netns.h"
+#include "sysfs.h"
+
+#include "nfstrace.h"
+
+#define NFSDBG_FACILITY		NFSDBG_VFS
+
+#define NFS_64_BIT_INODE_NUMBERS_ENABLED	1
+
+/* Default is to see 64-bit inode numbers */
+static bool enable_ino64 = NFS_64_BIT_INODE_NUMBERS_ENABLED;
+
+static int nfs_update_inode(struct inode *, struct nfs_fattr *);
+
+static struct kmem_cache * nfs_inode_cachep;
+
+static inline unsigned long
+nfs_fattr_to_ino_t(struct nfs_fattr *fattr)
+{
+	return nfs_fileid_to_ino_t(fattr->fileid);
+}
+
+static int nfs_wait_killable(int mode)
+{
+	freezable_schedule_unsafe();
+	if (signal_pending_state(mode, current))
+		return -ERESTARTSYS;
+	return 0;
+}
+
+int nfs_wait_bit_killable(struct wait_bit_key *key, int mode)
+{
+	return nfs_wait_killable(mode);
+}
+EXPORT_SYMBOL_GPL(nfs_wait_bit_killable);
+
+/**
+ * nfs_compat_user_ino64 - returns the user-visible inode number
+ * @fileid: 64-bit fileid
+ *
+ * This function returns a 32-bit inode number if the boot parameter
+ * nfs.enable_ino64 is zero.
+ */
+u64 nfs_compat_user_ino64(u64 fileid)
+{
+#ifdef CONFIG_COMPAT
+	compat_ulong_t ino;
+#else	
+	unsigned long ino;
+#endif
+
+	if (enable_ino64)
+		return fileid;
+	ino = fileid;
+	if (sizeof(ino) < sizeof(fileid))
+		ino ^= fileid >> (sizeof(fileid)-sizeof(ino)) * 8;
+	return ino;
+}
+
+int nfs_drop_inode(struct inode *inode)
+{
+	return NFS_STALE(inode) || generic_drop_inode(inode);
+}
+EXPORT_SYMBOL_GPL(nfs_drop_inode);
+
+void nfs_clear_inode(struct inode *inode)
+{
+	/*
+	 * The following should never happen...
+	 */
+	WARN_ON_ONCE(nfs_have_writebacks(inode));
+	WARN_ON_ONCE(!list_empty(&NFS_I(inode)->open_files));
+	nfs_zap_acl_cache(inode);
+	nfs_access_zap_cache(inode);
+	nfs_fscache_clear_inode(inode);
+}
+EXPORT_SYMBOL_GPL(nfs_clear_inode);
+
+void nfs_evict_inode(struct inode *inode)
+{
+	truncate_inode_pages_final(&inode->i_data);
+	clear_inode(inode);
+	nfs_clear_inode(inode);
+}
+
+int nfs_sync_inode(struct inode *inode)
+{
+	inode_dio_wait(inode);
+	return nfs_wb_all(inode);
+}
+EXPORT_SYMBOL_GPL(nfs_sync_inode);
+
+/**
+ * nfs_sync_mapping - helper to flush all mmapped dirty data to disk
+ * @mapping: pointer to struct address_space
+ */
+int nfs_sync_mapping(struct address_space *mapping)
+{
+	int ret = 0;
+
+	if (mapping->nrpages != 0) {
+		unmap_mapping_range(mapping, 0, 0, 0);
+		ret = nfs_wb_all(mapping->host);
+	}
+	return ret;
+}
+
+static int nfs_attribute_timeout(struct inode *inode)
+{
+	struct nfs_inode *nfsi = NFS_I(inode);
+
+	return !time_in_range_open(jiffies, nfsi->read_cache_jiffies, nfsi->read_cache_jiffies + nfsi->attrtimeo);
+}
+
+static bool nfs_check_cache_invalid_delegated(struct inode *inode, unsigned long flags)
+{
+	unsigned long cache_validity = READ_ONCE(NFS_I(inode)->cache_validity);
+
+	/* Special case for the pagecache or access cache */
+	if (flags == NFS_INO_REVAL_PAGECACHE &&
+	    !(cache_validity & NFS_INO_REVAL_FORCED))
+		return false;
+	return (cache_validity & flags) != 0;
+}
+
+static bool nfs_check_cache_invalid_not_delegated(struct inode *inode, unsigned long flags)
+{
+	unsigned long cache_validity = READ_ONCE(NFS_I(inode)->cache_validity);
+
+	if ((cache_validity & flags) != 0)
+		return true;
+	if (nfs_attribute_timeout(inode))
+		return true;
+	return false;
+}
+
+bool nfs_check_cache_invalid(struct inode *inode, unsigned long flags)
+{
+	if (NFS_PROTO(inode)->have_delegation(inode, FMODE_READ))
+		return nfs_check_cache_invalid_delegated(inode, flags);
+
+	return nfs_check_cache_invalid_not_delegated(inode, flags);
+}
+EXPORT_SYMBOL_GPL(nfs_check_cache_invalid);
+
+#ifdef CONFIG_NFS_V4_2
+static bool nfs_has_xattr_cache(const struct nfs_inode *nfsi)
+{
+	return nfsi->xattr_cache != NULL;
+}
+#else
+static bool nfs_has_xattr_cache(const struct nfs_inode *nfsi)
+{
+	return false;
+}
+#endif
+
+static void nfs_set_cache_invalid(struct inode *inode, unsigned long flags)
+{
+	struct nfs_inode *nfsi = NFS_I(inode);
+	bool have_delegation = NFS_PROTO(inode)->have_delegation(inode, FMODE_READ);
+
+	if (have_delegation) {
+		if (!(flags & NFS_INO_REVAL_FORCED))
+			flags &= ~NFS_INO_INVALID_OTHER;
+		flags &= ~(NFS_INO_INVALID_CHANGE
+				| NFS_INO_INVALID_SIZE
+				| NFS_INO_REVAL_PAGECACHE
+				| NFS_INO_INVALID_XATTR);
+	} else if (flags & NFS_INO_REVAL_PAGECACHE)
+		flags |= NFS_INO_INVALID_CHANGE | NFS_INO_INVALID_SIZE;
+
+	if (!nfs_has_xattr_cache(nfsi))
+		flags &= ~NFS_INO_INVALID_XATTR;
+	if (inode->i_mapping->nrpages == 0)
+		flags &= ~(NFS_INO_INVALID_DATA|NFS_INO_DATA_INVAL_DEFER);
+	nfsi->cache_validity |= flags;
+	if (flags & NFS_INO_INVALID_DATA)
+		nfs_fscache_invalidate(inode);
+}
+
+/*
+ * Invalidate the local caches
+ */
+static void nfs_zap_caches_locked(struct inode *inode)
+{
+	struct nfs_inode *nfsi = NFS_I(inode);
+	int mode = inode->i_mode;
+
+	nfs_inc_stats(inode, NFSIOS_ATTRINVALIDATE);
+
+	nfsi->attrtimeo = NFS_MINATTRTIMEO(inode);
+	nfsi->attrtimeo_timestamp = jiffies;
+
+	memset(NFS_I(inode)->cookieverf, 0, sizeof(NFS_I(inode)->cookieverf));
+	if (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode)) {
+		nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATTR
+					| NFS_INO_INVALID_DATA
+					| NFS_INO_INVALID_ACCESS
+					| NFS_INO_INVALID_ACL
+					| NFS_INO_INVALID_XATTR
+					| NFS_INO_REVAL_PAGECACHE);
+	} else
+		nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATTR
+					| NFS_INO_INVALID_ACCESS
+					| NFS_INO_INVALID_ACL
+					| NFS_INO_INVALID_XATTR
+					| NFS_INO_REVAL_PAGECACHE);
+	nfs_zap_label_cache_locked(nfsi);
+}
+
+void nfs_zap_caches(struct inode *inode)
+{
+	spin_lock(&inode->i_lock);
+	nfs_zap_caches_locked(inode);
+	spin_unlock(&inode->i_lock);
+}
+
+void nfs_zap_mapping(struct inode *inode, struct address_space *mapping)
+{
+	if (mapping->nrpages != 0) {
+		spin_lock(&inode->i_lock);
+		nfs_set_cache_invalid(inode, NFS_INO_INVALID_DATA);
+		spin_unlock(&inode->i_lock);
+	}
+}
+
+void nfs_zap_acl_cache(struct inode *inode)
+{
+	void (*clear_acl_cache)(struct inode *);
+
+	clear_acl_cache = NFS_PROTO(inode)->clear_acl_cache;
+	if (clear_acl_cache != NULL)
+		clear_acl_cache(inode);
+	spin_lock(&inode->i_lock);
+	NFS_I(inode)->cache_validity &= ~NFS_INO_INVALID_ACL;
+	spin_unlock(&inode->i_lock);
+}
+EXPORT_SYMBOL_GPL(nfs_zap_acl_cache);
+
+void nfs_invalidate_atime(struct inode *inode)
+{
+	spin_lock(&inode->i_lock);
+	nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATIME);
+	spin_unlock(&inode->i_lock);
+}
+EXPORT_SYMBOL_GPL(nfs_invalidate_atime);
+
+/*
+ * Invalidate, but do not unhash, the inode.
+ * NB: must be called with inode->i_lock held!
+ */
+static void nfs_set_inode_stale_locked(struct inode *inode)
+{
+	set_bit(NFS_INO_STALE, &NFS_I(inode)->flags);
+	nfs_zap_caches_locked(inode);
+	trace_nfs_set_inode_stale(inode);
+}
+
+void nfs_set_inode_stale(struct inode *inode)
+{
+	spin_lock(&inode->i_lock);
+	nfs_set_inode_stale_locked(inode);
+	spin_unlock(&inode->i_lock);
+}
+
+struct nfs_find_desc {
+	struct nfs_fh		*fh;
+	struct nfs_fattr	*fattr;
+};
+
+/*
+ * In NFSv3 we can have 64bit inode numbers. In order to support
+ * this, and re-exported directories (also seen in NFSv2)
+ * we are forced to allow 2 different inodes to have the same
+ * i_ino.
+ */
+static int
+nfs_find_actor(struct inode *inode, void *opaque)
+{
+	struct nfs_find_desc	*desc = (struct nfs_find_desc *)opaque;
+	struct nfs_fh		*fh = desc->fh;
+	struct nfs_fattr	*fattr = desc->fattr;
+
+	if (NFS_FILEID(inode) != fattr->fileid)
+		return 0;
+	if (inode_wrong_type(inode, fattr->mode))
+		return 0;
+	if (nfs_compare_fh(NFS_FH(inode), fh))
+		return 0;
+	if (is_bad_inode(inode) || NFS_STALE(inode))
+		return 0;
+	return 1;
+}
+
+static int
+nfs_init_locked(struct inode *inode, void *opaque)
+{
+	struct nfs_find_desc	*desc = (struct nfs_find_desc *)opaque;
+	struct nfs_fattr	*fattr = desc->fattr;
+
+	set_nfs_fileid(inode, fattr->fileid);
+	inode->i_mode = fattr->mode;
+	nfs_copy_fh(NFS_FH(inode), desc->fh);
+	return 0;
+}
+
+#ifdef CONFIG_NFS_V4_SECURITY_LABEL
+static void nfs_clear_label_invalid(struct inode *inode)
+{
+	spin_lock(&inode->i_lock);
+	NFS_I(inode)->cache_validity &= ~NFS_INO_INVALID_LABEL;
+	spin_unlock(&inode->i_lock);
+}
+
+void nfs_setsecurity(struct inode *inode, struct nfs_fattr *fattr,
+					struct nfs4_label *label)
+{
+	int error;
+
+	if (label == NULL)
+		return;
+
+	if ((fattr->valid & NFS_ATTR_FATTR_V4_SECURITY_LABEL) && inode->i_security) {
+		error = security_inode_notifysecctx(inode, label->label,
+				label->len);
+		if (error)
+			printk(KERN_ERR "%s() %s %d "
+					"security_inode_notifysecctx() %d\n",
+					__func__,
+					(char *)label->label,
+					label->len, error);
+		nfs_clear_label_invalid(inode);
+	}
+}
+
+struct nfs4_label *nfs4_label_alloc(struct nfs_server *server, gfp_t flags)
+{
+	struct nfs4_label *label = NULL;
+	int minor_version = server->nfs_client->cl_minorversion;
+
+	if (minor_version < 2)
+		return label;
+
+	if (!(server->caps & NFS_CAP_SECURITY_LABEL))
+		return label;
+
+	label = kzalloc(sizeof(struct nfs4_label), flags);
+	if (label == NULL)
+		return ERR_PTR(-ENOMEM);
+
+	label->label = kzalloc(NFS4_MAXLABELLEN, flags);
+	if (label->label == NULL) {
+		kfree(label);
+		return ERR_PTR(-ENOMEM);
+	}
+	label->len = NFS4_MAXLABELLEN;
+
+	return label;
+}
+EXPORT_SYMBOL_GPL(nfs4_label_alloc);
+#else
+void nfs_setsecurity(struct inode *inode, struct nfs_fattr *fattr,
+					struct nfs4_label *label)
+{
+}
+#endif
+EXPORT_SYMBOL_GPL(nfs_setsecurity);
+
+/* Search for inode identified by fh, fileid and i_mode in inode cache. */
+struct inode *
+nfs_ilookup(struct super_block *sb, struct nfs_fattr *fattr, struct nfs_fh *fh)
+{
+	struct nfs_find_desc desc = {
+		.fh	= fh,
+		.fattr	= fattr,
+	};
+	struct inode *inode;
+	unsigned long hash;
+
+	if (!(fattr->valid & NFS_ATTR_FATTR_FILEID) ||
+	    !(fattr->valid & NFS_ATTR_FATTR_TYPE))
+		return NULL;
+
+	hash = nfs_fattr_to_ino_t(fattr);
+	inode = ilookup5(sb, hash, nfs_find_actor, &desc);
+
+	dprintk("%s: returning %p\n", __func__, inode);
+	return inode;
+}
+
+/*
+ * This is our front-end to iget that looks up inodes by file handle
+ * instead of inode number.
+ */
+struct inode *
+nfs_fhget(struct super_block *sb, struct nfs_fh *fh, struct nfs_fattr *fattr, struct nfs4_label *label)
+{
+	struct nfs_find_desc desc = {
+		.fh	= fh,
+		.fattr	= fattr
+	};
+	struct inode *inode = ERR_PTR(-ENOENT);
+	unsigned long hash;
+
+	nfs_attr_check_mountpoint(sb, fattr);
+
+	if (nfs_attr_use_mounted_on_fileid(fattr))
+		fattr->fileid = fattr->mounted_on_fileid;
+	else if ((fattr->valid & NFS_ATTR_FATTR_FILEID) == 0)
+		goto out_no_inode;
+	if ((fattr->valid & NFS_ATTR_FATTR_TYPE) == 0)
+		goto out_no_inode;
+
+	hash = nfs_fattr_to_ino_t(fattr);
+
+	inode = iget5_locked(sb, hash, nfs_find_actor, nfs_init_locked, &desc);
+	if (inode == NULL) {
+		inode = ERR_PTR(-ENOMEM);
+		goto out_no_inode;
+	}
+
+	if (inode->i_state & I_NEW) {
+		struct nfs_inode *nfsi = NFS_I(inode);
+		unsigned long now = jiffies;
+
+		/* We set i_ino for the few things that still rely on it,
+		 * such as stat(2) */
+		inode->i_ino = hash;
+
+		/* We can't support update_atime(), since the server will reset it */
+		inode->i_flags |= S_NOATIME|S_NOCMTIME;
+		inode->i_mode = fattr->mode;
+		nfsi->cache_validity = 0;
+		if ((fattr->valid & NFS_ATTR_FATTR_MODE) == 0
+				&& nfs_server_capable(inode, NFS_CAP_MODE))
+			nfs_set_cache_invalid(inode, NFS_INO_INVALID_OTHER);
+		/* Why so? Because we want revalidate for devices/FIFOs, and
+		 * that's precisely what we have in nfs_file_inode_operations.
+		 */
+		inode->i_op = NFS_SB(sb)->nfs_client->rpc_ops->file_inode_ops;
+		if (S_ISREG(inode->i_mode)) {
+			inode->i_fop = NFS_SB(sb)->nfs_client->rpc_ops->file_ops;
+			inode->i_data.a_ops = &nfs_file_aops;
+		} else if (S_ISDIR(inode->i_mode)) {
+			inode->i_op = NFS_SB(sb)->nfs_client->rpc_ops->dir_inode_ops;
+			inode->i_fop = &nfs_dir_operations;
+			inode->i_data.a_ops = &nfs_dir_aops;
+			/* Deal with crossing mountpoints */
+			if (fattr->valid & NFS_ATTR_FATTR_MOUNTPOINT ||
+					fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL) {
+				if (fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL)
+					inode->i_op = &nfs_referral_inode_operations;
+				else
+					inode->i_op = &nfs_mountpoint_inode_operations;
+				inode->i_fop = NULL;
+				inode->i_flags |= S_AUTOMOUNT;
+			}
+		} else if (S_ISLNK(inode->i_mode)) {
+			inode->i_op = &nfs_symlink_inode_operations;
+			inode_nohighmem(inode);
+		} else
+			init_special_inode(inode, inode->i_mode, fattr->rdev);
+
+		memset(&inode->i_atime, 0, sizeof(inode->i_atime));
+		memset(&inode->i_mtime, 0, sizeof(inode->i_mtime));
+		memset(&inode->i_ctime, 0, sizeof(inode->i_ctime));
+		inode_set_iversion_raw(inode, 0);
+		inode->i_size = 0;
+		clear_nlink(inode);
+		inode->i_uid = make_kuid(&init_user_ns, -2);
+		inode->i_gid = make_kgid(&init_user_ns, -2);
+		inode->i_blocks = 0;
+		memset(nfsi->cookieverf, 0, sizeof(nfsi->cookieverf));
+		nfsi->write_io = 0;
+		nfsi->read_io = 0;
+
+		nfsi->read_cache_jiffies = fattr->time_start;
+		nfsi->attr_gencount = fattr->gencount;
+		if (fattr->valid & NFS_ATTR_FATTR_ATIME)
+			inode->i_atime = fattr->atime;
+		else if (nfs_server_capable(inode, NFS_CAP_ATIME))
+			nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATIME);
+		if (fattr->valid & NFS_ATTR_FATTR_MTIME)
+			inode->i_mtime = fattr->mtime;
+		else if (nfs_server_capable(inode, NFS_CAP_MTIME))
+			nfs_set_cache_invalid(inode, NFS_INO_INVALID_MTIME);
+		if (fattr->valid & NFS_ATTR_FATTR_CTIME)
+			inode->i_ctime = fattr->ctime;
+		else if (nfs_server_capable(inode, NFS_CAP_CTIME))
+			nfs_set_cache_invalid(inode, NFS_INO_INVALID_CTIME);
+		if (fattr->valid & NFS_ATTR_FATTR_CHANGE)
+			inode_set_iversion_raw(inode, fattr->change_attr);
+		else
+			nfs_set_cache_invalid(inode, NFS_INO_INVALID_CHANGE);
+		if (fattr->valid & NFS_ATTR_FATTR_SIZE)
+			inode->i_size = nfs_size_to_loff_t(fattr->size);
+		else
+			nfs_set_cache_invalid(inode, NFS_INO_INVALID_SIZE);
+		if (fattr->valid & NFS_ATTR_FATTR_NLINK)
+			set_nlink(inode, fattr->nlink);
+		else if (nfs_server_capable(inode, NFS_CAP_NLINK))
+			nfs_set_cache_invalid(inode, NFS_INO_INVALID_OTHER);
+		if (fattr->valid & NFS_ATTR_FATTR_OWNER)
+			inode->i_uid = fattr->uid;
+		else if (nfs_server_capable(inode, NFS_CAP_OWNER))
+			nfs_set_cache_invalid(inode, NFS_INO_INVALID_OTHER);
+		if (fattr->valid & NFS_ATTR_FATTR_GROUP)
+			inode->i_gid = fattr->gid;
+		else if (nfs_server_capable(inode, NFS_CAP_OWNER_GROUP))
+			nfs_set_cache_invalid(inode, NFS_INO_INVALID_OTHER);
+		if (nfs_server_capable(inode, NFS_CAP_XATTR))
+			nfs_set_cache_invalid(inode, NFS_INO_INVALID_XATTR);
+		if (fattr->valid & NFS_ATTR_FATTR_BLOCKS_USED)
+			inode->i_blocks = fattr->du.nfs2.blocks;
+		if (fattr->valid & NFS_ATTR_FATTR_SPACE_USED) {
+			/*
+			 * report the blocks in 512byte units
+			 */
+			inode->i_blocks = nfs_calc_block_size(fattr->du.nfs3.used);
+		}
+
+		if (nfsi->cache_validity != 0)
+			nfsi->cache_validity |= NFS_INO_REVAL_FORCED;
+
+		nfs_setsecurity(inode, fattr, label);
+
+		nfsi->attrtimeo = NFS_MINATTRTIMEO(inode);
+		nfsi->attrtimeo_timestamp = now;
+		nfsi->access_cache = RB_ROOT;
+
+		nfs_fscache_init_inode(inode);
+
+		unlock_new_inode(inode);
+	} else {
+		int err = nfs_refresh_inode(inode, fattr);
+		if (err < 0) {
+			iput(inode);
+			inode = ERR_PTR(err);
+			goto out_no_inode;
+		}
+	}
+	dprintk("NFS: nfs_fhget(%s/%Lu fh_crc=0x%08x ct=%d)\n",
+		inode->i_sb->s_id,
+		(unsigned long long)NFS_FILEID(inode),
+		nfs_display_fhandle_hash(fh),
+		atomic_read(&inode->i_count));
+
+out:
+	return inode;
+
+out_no_inode:
+	dprintk("nfs_fhget: iget failed with error %ld\n", PTR_ERR(inode));
+	goto out;
+}
+EXPORT_SYMBOL_GPL(nfs_fhget);
+
+#define NFS_VALID_ATTRS (ATTR_MODE|ATTR_UID|ATTR_GID|ATTR_SIZE|ATTR_ATIME|ATTR_ATIME_SET|ATTR_MTIME|ATTR_MTIME_SET|ATTR_FILE|ATTR_OPEN)
+
+int
+nfs_setattr(struct dentry *dentry, struct iattr *attr)
+{
+	struct inode *inode = d_inode(dentry);
+	struct nfs_fattr *fattr;
+	int error = 0;
+
+	nfs_inc_stats(inode, NFSIOS_VFSSETATTR);
+
+	/* skip mode change if it's just for clearing setuid/setgid */
+	if (attr->ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
+		attr->ia_valid &= ~ATTR_MODE;
+
+	if (attr->ia_valid & ATTR_SIZE) {
+		BUG_ON(!S_ISREG(inode->i_mode));
+
+		error = inode_newsize_ok(inode, attr->ia_size);
+		if (error)
+			return error;
+
+		if (attr->ia_size == i_size_read(inode))
+			attr->ia_valid &= ~ATTR_SIZE;
+	}
+
+	/* Optimization: if the end result is no change, don't RPC */
+	attr->ia_valid &= NFS_VALID_ATTRS;
+	if ((attr->ia_valid & ~(ATTR_FILE|ATTR_OPEN)) == 0)
+		return 0;
+
+	trace_nfs_setattr_enter(inode);
+
+	/* Write all dirty data */
+	if (S_ISREG(inode->i_mode))
+		nfs_sync_inode(inode);
+
+	fattr = nfs_alloc_fattr();
+	if (fattr == NULL) {
+		error = -ENOMEM;
+		goto out;
+	}
+
+	error = NFS_PROTO(inode)->setattr(dentry, fattr, attr);
+	if (error == 0)
+		error = nfs_refresh_inode(inode, fattr);
+	nfs_free_fattr(fattr);
+out:
+	trace_nfs_setattr_exit(inode, error);
+	return error;
+}
+EXPORT_SYMBOL_GPL(nfs_setattr);
+
+/**
+ * nfs_vmtruncate - unmap mappings "freed" by truncate() syscall
+ * @inode: inode of the file used
+ * @offset: file offset to start truncating
+ *
+ * This is a copy of the common vmtruncate, but with the locking
+ * corrected to take into account the fact that NFS requires
+ * inode->i_size to be updated under the inode->i_lock.
+ * Note: must be called with inode->i_lock held!
+ */
+static int nfs_vmtruncate(struct inode * inode, loff_t offset)
+{
+	int err;
+
+	err = inode_newsize_ok(inode, offset);
+	if (err)
+		goto out;
+
+	i_size_write(inode, offset);
+	/* Optimisation */
+	if (offset == 0)
+		NFS_I(inode)->cache_validity &= ~(NFS_INO_INVALID_DATA |
+				NFS_INO_DATA_INVAL_DEFER);
+	NFS_I(inode)->cache_validity &= ~NFS_INO_INVALID_SIZE;
+
+	spin_unlock(&inode->i_lock);
+	truncate_pagecache(inode, offset);
+	spin_lock(&inode->i_lock);
+out:
+	return err;
+}
+
+/**
+ * nfs_setattr_update_inode - Update inode metadata after a setattr call.
+ * @inode: pointer to struct inode
+ * @attr: pointer to struct iattr
+ * @fattr: pointer to struct nfs_fattr
+ *
+ * Note: we do this in the *proc.c in order to ensure that
+ *       it works for things like exclusive creates too.
+ */
+void nfs_setattr_update_inode(struct inode *inode, struct iattr *attr,
+		struct nfs_fattr *fattr)
+{
+	/* Barrier: bump the attribute generation count. */
+	nfs_fattr_set_barrier(fattr);
+
+	spin_lock(&inode->i_lock);
+	NFS_I(inode)->attr_gencount = fattr->gencount;
+	if ((attr->ia_valid & ATTR_SIZE) != 0) {
+		nfs_set_cache_invalid(inode, NFS_INO_INVALID_MTIME);
+		nfs_inc_stats(inode, NFSIOS_SETATTRTRUNC);
+		nfs_vmtruncate(inode, attr->ia_size);
+	}
+	if ((attr->ia_valid & (ATTR_MODE|ATTR_UID|ATTR_GID)) != 0) {
+		NFS_I(inode)->cache_validity &= ~NFS_INO_INVALID_CTIME;
+		if ((attr->ia_valid & ATTR_MODE) != 0) {
+			int mode = attr->ia_mode & S_IALLUGO;
+			mode |= inode->i_mode & ~S_IALLUGO;
+			inode->i_mode = mode;
+		}
+		if ((attr->ia_valid & ATTR_UID) != 0)
+			inode->i_uid = attr->ia_uid;
+		if ((attr->ia_valid & ATTR_GID) != 0)
+			inode->i_gid = attr->ia_gid;
+		if (fattr->valid & NFS_ATTR_FATTR_CTIME)
+			inode->i_ctime = fattr->ctime;
+		else
+			nfs_set_cache_invalid(inode, NFS_INO_INVALID_CHANGE
+					| NFS_INO_INVALID_CTIME);
+		nfs_set_cache_invalid(inode, NFS_INO_INVALID_ACCESS
+				| NFS_INO_INVALID_ACL);
+	}
+	if (attr->ia_valid & (ATTR_ATIME_SET|ATTR_ATIME)) {
+		NFS_I(inode)->cache_validity &= ~(NFS_INO_INVALID_ATIME
+				| NFS_INO_INVALID_CTIME);
+		if (fattr->valid & NFS_ATTR_FATTR_ATIME)
+			inode->i_atime = fattr->atime;
+		else if (attr->ia_valid & ATTR_ATIME_SET)
+			inode->i_atime = attr->ia_atime;
+		else
+			nfs_set_cache_invalid(inode, NFS_INO_INVALID_ATIME);
+
+		if (fattr->valid & NFS_ATTR_FATTR_CTIME)
+			inode->i_ctime = fattr->ctime;
+		else
+			nfs_set_cache_invalid(inode, NFS_INO_INVALID_CHANGE
+					| NFS_INO_INVALID_CTIME);
+	}
+	if (attr->ia_valid & (ATTR_MTIME_SET|ATTR_MTIME)) {
+		NFS_I(inode)->cache_validity &= ~(NFS_INO_INVALID_MTIME
+				| NFS_INO_INVALID_CTIME);
+		if (fattr->valid & NFS_ATTR_FATTR_MTIME)
+			inode->i_mtime = fattr->mtime;
+		else if (attr->ia_valid & ATTR_MTIME_SET)
+			inode->i_mtime = attr->ia_mtime;
+		else
+			nfs_set_cache_invalid(inode, NFS_INO_INVALID_MTIME);
+
+		if (fattr->valid & NFS_ATTR_FATTR_CTIME)
+			inode->i_ctime = fattr->ctime;
+		else
+			nfs_set_cache_invalid(inode, NFS_INO_INVALID_CHANGE
+					| NFS_INO_INVALID_CTIME);
+	}
+	if (fattr->valid)
+		nfs_update_inode(inode, fattr);
+	spin_unlock(&inode->i_lock);
+}
+EXPORT_SYMBOL_GPL(nfs_setattr_update_inode);
+
+static void nfs_readdirplus_parent_cache_miss(struct dentry *dentry)
+{
+	struct dentry *parent;
+
+	if (!nfs_server_capable(d_inode(dentry), NFS_CAP_READDIRPLUS))
+		return;
+	parent = dget_parent(dentry);
+	nfs_force_use_readdirplus(d_inode(parent));
+	dput(parent);
+}
+
+static void nfs_readdirplus_parent_cache_hit(struct dentry *dentry)
+{
+	struct dentry *parent;
+
+	if (!nfs_server_capable(d_inode(dentry), NFS_CAP_READDIRPLUS))
+		return;
+	parent = dget_parent(dentry);
+	nfs_advise_use_readdirplus(d_inode(parent));
+	dput(parent);
+}
+
+static bool nfs_need_revalidate_inode(struct inode *inode)
+{
+	if (NFS_I(inode)->cache_validity &
+			(NFS_INO_INVALID_ATTR|NFS_INO_INVALID_LABEL))
+		return true;
+	if (nfs_attribute_cache_expired(inode))
+		return true;
+	return false;
+}
+
+int nfs_getattr(const struct path *path, struct kstat *stat,
+		u32 request_mask, unsigned int query_flags)
+{
+	struct inode *inode = d_inode(path->dentry);
+	struct nfs_server *server = NFS_SERVER(inode);
+	unsigned long cache_validity;
+	int err = 0;
+	bool force_sync = query_flags & AT_STATX_FORCE_SYNC;
+	bool do_update = false;
+
+	trace_nfs_getattr_enter(inode);
+
+	if ((query_flags & AT_STATX_DONT_SYNC) && !force_sync) {
+		nfs_readdirplus_parent_cache_hit(path->dentry);
+		goto out_no_update;
+	}
+
+	/* Flush out writes to the server in order to update c/mtime.  */
+	if ((request_mask & (STATX_CTIME | STATX_MTIME)) &&
+	    S_ISREG(inode->i_mode))
+		filemap_write_and_wait(inode->i_mapping);
+
+	/*
+	 * We may force a getattr if the user cares about atime.
+	 *
+	 * Note that we only have to check the vfsmount flags here:
+	 *  - NFS always sets S_NOATIME by so checking it would give a
+	 *    bogus result
+	 *  - NFS never sets SB_NOATIME or SB_NODIRATIME so there is
+	 *    no point in checking those.
+	 */
+	if ((path->mnt->mnt_flags & MNT_NOATIME) ||
+	    ((path->mnt->mnt_flags & MNT_NODIRATIME) && S_ISDIR(inode->i_mode)))
+		request_mask &= ~STATX_ATIME;
+
+	/* Is the user requesting attributes that might need revalidation? */
+	if (!(request_mask & (STATX_MODE|STATX_NLINK|STATX_ATIME|STATX_CTIME|
+					STATX_MTIME|STATX_UID|STATX_GID|
+					STATX_SIZE|STATX_BLOCKS)))
+		goto out_no_revalidate;
+
+	/* Check whether the cached attributes are stale */
+	do_update |= force_sync || nfs_attribute_cache_expired(inode);
+	cache_validity = READ_ONCE(NFS_I(inode)->cache_validity);
+	do_update |= cache_validity &
+		(NFS_INO_INVALID_ATTR|NFS_INO_INVALID_LABEL);
+	if (request_mask & STATX_ATIME)
+		do_update |= cache_validity & NFS_INO_INVALID_ATIME;
+	if (request_mask & (STATX_CTIME|STATX_MTIME))
+		do_update |= cache_validity & NFS_INO_REVAL_PAGECACHE;
+	if (request_mask & STATX_BLOCKS)
+		do_update |= cache_validity & NFS_INO_INVALID_BLOCKS;
+	if (do_update) {
+		/* Update the attribute cache */
+		if (!(server->flags & NFS_MOUNT_NOAC))
+			nfs_readdirplus_parent_cache_miss(path->dentry);
+		else
+			nfs_readdirplus_parent_cache_hit(path->dentry);
+		err = __nfs_revalidate_inode(server, inode);
+		if (err)
+			goto out;
+	} else
+		nfs_readdirplus_parent_cache_hit(path->dentry);
+out_no_revalidate:
+	/* Only return attributes that were revalidated. */
+	stat->result_mask &= request_mask;
+out_no_update:
+	generic_fillattr(inode, stat);
+	stat->ino = nfs_compat_user_ino64(NFS_FILEID(inode));
+	if (S_ISDIR(inode->i_mode))
+		stat->blksize = NFS_SERVER(inode)->dtsize;
+out:
+	trace_nfs_getattr_exit(inode, err);
+	return err;
+}
+EXPORT_SYMBOL_GPL(nfs_getattr);
+
+static void nfs_init_lock_context(struct nfs_lock_context *l_ctx)
+{
+	refcount_set(&l_ctx->count, 1);
+	l_ctx->lockowner = current->files;
+	INIT_LIST_HEAD(&l_ctx->list);
+	atomic_set(&l_ctx->io_count, 0);
+}
+
+static struct nfs_lock_context *__nfs_find_lock_context(struct nfs_open_context *ctx)
+{
+	struct nfs_lock_context *pos;
+
+	list_for_each_entry_rcu(pos, &ctx->lock_context.list, list) {
+		if (pos->lockowner != current->files)
+			continue;
+		if (refcount_inc_not_zero(&pos->count))
+			return pos;
+	}
+	return NULL;
+}
+
+struct nfs_lock_context *nfs_get_lock_context(struct nfs_open_context *ctx)
+{
+	struct nfs_lock_context *res, *new = NULL;
+	struct inode *inode = d_inode(ctx->dentry);
+
+	rcu_read_lock();
+	res = __nfs_find_lock_context(ctx);
+	rcu_read_unlock();
+	if (res == NULL) {
+		new = kmalloc(sizeof(*new), GFP_KERNEL);
+		if (new == NULL)
+			return ERR_PTR(-ENOMEM);
+		nfs_init_lock_context(new);
+		spin_lock(&inode->i_lock);
+		res = __nfs_find_lock_context(ctx);
+		if (res == NULL) {
+			new->open_context = get_nfs_open_context(ctx);
+			if (new->open_context) {
+				list_add_tail_rcu(&new->list,
+						&ctx->lock_context.list);
+				res = new;
+				new = NULL;
+			} else
+				res = ERR_PTR(-EBADF);
+		}
+		spin_unlock(&inode->i_lock);
+		kfree(new);
+	}
+	return res;
+}
+EXPORT_SYMBOL_GPL(nfs_get_lock_context);
+
+void nfs_put_lock_context(struct nfs_lock_context *l_ctx)
+{
+	struct nfs_open_context *ctx = l_ctx->open_context;
+	struct inode *inode = d_inode(ctx->dentry);
+
+	if (!refcount_dec_and_lock(&l_ctx->count, &inode->i_lock))
+		return;
+	list_del_rcu(&l_ctx->list);
+	spin_unlock(&inode->i_lock);
+	put_nfs_open_context(ctx);
+	kfree_rcu(l_ctx, rcu_head);
+}
+EXPORT_SYMBOL_GPL(nfs_put_lock_context);
+
+/**
+ * nfs_close_context - Common close_context() routine NFSv2/v3
+ * @ctx: pointer to context
+ * @is_sync: is this a synchronous close
+ *
+ * Ensure that the attributes are up to date if we're mounted
+ * with close-to-open semantics and we have cached data that will
+ * need to be revalidated on open.
+ */
+void nfs_close_context(struct nfs_open_context *ctx, int is_sync)
+{
+	struct nfs_inode *nfsi;
+	struct inode *inode;
+	struct nfs_server *server;
+
+	if (!(ctx->mode & FMODE_WRITE))
+		return;
+	if (!is_sync)
+		return;
+	inode = d_inode(ctx->dentry);
+	if (NFS_PROTO(inode)->have_delegation(inode, FMODE_READ))
+		return;
+	nfsi = NFS_I(inode);
+	if (inode->i_mapping->nrpages == 0)
+		return;
+	if (nfsi->cache_validity & NFS_INO_INVALID_DATA)
+		return;
+	if (!list_empty(&nfsi->open_files))
+		return;
+	server = NFS_SERVER(inode);
+	if (server->flags & NFS_MOUNT_NOCTO)
+		return;
+	nfs_revalidate_inode(server, inode);
+}
+EXPORT_SYMBOL_GPL(nfs_close_context);
+
+struct nfs_open_context *alloc_nfs_open_context(struct dentry *dentry,
+						fmode_t f_mode,
+						struct file *filp)
+{
+	struct nfs_open_context *ctx;
+
+	ctx = kmalloc(sizeof(*ctx), GFP_KERNEL);
+	if (!ctx)
+		return ERR_PTR(-ENOMEM);
+	nfs_sb_active(dentry->d_sb);
+	ctx->dentry = dget(dentry);
+	if (filp)
+		ctx->cred = get_cred(filp->f_cred);
+	else
+		ctx->cred = get_current_cred();
+	ctx->ll_cred = NULL;
+	ctx->state = NULL;
+	ctx->mode = f_mode;
+	ctx->flags = 0;
+	ctx->error = 0;
+	ctx->flock_owner = (fl_owner_t)filp;
+	nfs_init_lock_context(&ctx->lock_context);
+	ctx->lock_context.open_context = ctx;
+	INIT_LIST_HEAD(&ctx->list);
+	ctx->mdsthreshold = NULL;
+	return ctx;
+}
+EXPORT_SYMBOL_GPL(alloc_nfs_open_context);
+
+struct nfs_open_context *get_nfs_open_context(struct nfs_open_context *ctx)
+{
+	if (ctx != NULL && refcount_inc_not_zero(&ctx->lock_context.count))
+		return ctx;
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(get_nfs_open_context);
+
+static void __put_nfs_open_context(struct nfs_open_context *ctx, int is_sync)
+{
+	struct inode *inode = d_inode(ctx->dentry);
+	struct super_block *sb = ctx->dentry->d_sb;
+
+	if (!refcount_dec_and_test(&ctx->lock_context.count))
+		return;
+	if (!list_empty(&ctx->list)) {
+		spin_lock(&inode->i_lock);
+		list_del_rcu(&ctx->list);
+		spin_unlock(&inode->i_lock);
+	}
+	if (inode != NULL)
+		NFS_PROTO(inode)->close_context(ctx, is_sync);
+	put_cred(ctx->cred);
+	dput(ctx->dentry);
+	nfs_sb_deactive(sb);
+	put_rpccred(ctx->ll_cred);
+	kfree(ctx->mdsthreshold);
+	kfree_rcu(ctx, rcu_head);
+}
+
+void put_nfs_open_context(struct nfs_open_context *ctx)
+{
+	__put_nfs_open_context(ctx, 0);
+}
+EXPORT_SYMBOL_GPL(put_nfs_open_context);
+
+static void put_nfs_open_context_sync(struct nfs_open_context *ctx)
+{
+	__put_nfs_open_context(ctx, 1);
+}
+
+/*
+ * Ensure that mmap has a recent RPC credential for use when writing out
+ * shared pages
+ */
+void nfs_inode_attach_open_context(struct nfs_open_context *ctx)
+{
+	struct inode *inode = d_inode(ctx->dentry);
+	struct nfs_inode *nfsi = NFS_I(inode);
+
+	spin_lock(&inode->i_lock);
+	if (list_empty(&nfsi->open_files) &&
+	    (nfsi->cache_validity & NFS_INO_DATA_INVAL_DEFER))
+		nfsi->cache_validity |= NFS_INO_INVALID_DATA |
+			NFS_INO_REVAL_FORCED;
+	list_add_tail_rcu(&ctx->list, &nfsi->open_files);
+	spin_unlock(&inode->i_lock);
+}
+EXPORT_SYMBOL_GPL(nfs_inode_attach_open_context);
+
+void nfs_file_set_open_context(struct file *filp, struct nfs_open_context *ctx)
+{
+	filp->private_data = get_nfs_open_context(ctx);
+	set_bit(NFS_CONTEXT_FILE_OPEN, &ctx->flags);
+	if (list_empty(&ctx->list))
+		nfs_inode_attach_open_context(ctx);
+}
+EXPORT_SYMBOL_GPL(nfs_file_set_open_context);
+
+/*
+ * Given an inode, search for an open context with the desired characteristics
+ */
+struct nfs_open_context *nfs_find_open_context(struct inode *inode, const struct cred *cred, fmode_t mode)
+{
+	struct nfs_inode *nfsi = NFS_I(inode);
+	struct nfs_open_context *pos, *ctx = NULL;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(pos, &nfsi->open_files, list) {
+		if (cred != NULL && cred_fscmp(pos->cred, cred) != 0)
+			continue;
+		if ((pos->mode & (FMODE_READ|FMODE_WRITE)) != mode)
+			continue;
+		if (!test_bit(NFS_CONTEXT_FILE_OPEN, &pos->flags))
+			continue;
+		ctx = get_nfs_open_context(pos);
+		if (ctx)
+			break;
+	}
+	rcu_read_unlock();
+	return ctx;
+}
+
+void nfs_file_clear_open_context(struct file *filp)
+{
+	struct nfs_open_context *ctx = nfs_file_open_context(filp);
+
+	if (ctx) {
+		struct inode *inode = d_inode(ctx->dentry);
+
+		clear_bit(NFS_CONTEXT_FILE_OPEN, &ctx->flags);
+		/*
+		 * We fatal error on write before. Try to writeback
+		 * every page again.
+		 */
+		if (ctx->error < 0)
+			invalidate_inode_pages2(inode->i_mapping);
+		filp->private_data = NULL;
+		put_nfs_open_context_sync(ctx);
+	}
+}
+
+/*
+ * These allocate and release file read/write context information.
+ */
+int nfs_open(struct inode *inode, struct file *filp)
+{
+	struct nfs_open_context *ctx;
+
+	ctx = alloc_nfs_open_context(file_dentry(filp), filp->f_mode, filp);
+	if (IS_ERR(ctx))
+		return PTR_ERR(ctx);
+	nfs_file_set_open_context(filp, ctx);
+	put_nfs_open_context(ctx);
+	nfs_fscache_open_file(inode, filp);
+	return 0;
+}
+
+/*
+ * This function is called whenever some part of NFS notices that
+ * the cached attributes have to be refreshed.
+ */
+int
+__nfs_revalidate_inode(struct nfs_server *server, struct inode *inode)
+{
+	int		 status = -ESTALE;
+	struct nfs4_label *label = NULL;
+	struct nfs_fattr *fattr = NULL;
+	struct nfs_inode *nfsi = NFS_I(inode);
+
+	dfprintk(PAGECACHE, "NFS: revalidating (%s/%Lu)\n",
+		inode->i_sb->s_id, (unsigned long long)NFS_FILEID(inode));
+
+	trace_nfs_revalidate_inode_enter(inode);
+
+	if (is_bad_inode(inode))
+		goto out;
+	if (NFS_STALE(inode))
+		goto out;
+
+	/* pNFS: Attributes aren't updated until we layoutcommit */
+	if (S_ISREG(inode->i_mode)) {
+		status = pnfs_sync_inode(inode, false);
+		if (status)
+			goto out;
+	}
+
+	status = -ENOMEM;
+	fattr = nfs_alloc_fattr();
+	if (fattr == NULL)
+		goto out;
+
+	nfs_inc_stats(inode, NFSIOS_INODEREVALIDATE);
+
+	label = nfs4_label_alloc(NFS_SERVER(inode), GFP_KERNEL);
+	if (IS_ERR(label)) {
+		status = PTR_ERR(label);
+		goto out;
+	}
+
+	status = NFS_PROTO(inode)->getattr(server, NFS_FH(inode), fattr,
+			label, inode);
+	if (status != 0) {
+		dfprintk(PAGECACHE, "nfs_revalidate_inode: (%s/%Lu) getattr failed, error=%d\n",
+			 inode->i_sb->s_id,
+			 (unsigned long long)NFS_FILEID(inode), status);
+		switch (status) {
+		case -ETIMEDOUT:
+			/* A soft timeout occurred. Use cached information? */
+			if (server->flags & NFS_MOUNT_SOFTREVAL)
+				status = 0;
+			break;
+		case -ESTALE:
+			if (!S_ISDIR(inode->i_mode))
+				nfs_set_inode_stale(inode);
+			else
+				nfs_zap_caches(inode);
+		}
+		goto err_out;
+	}
+
+	status = nfs_refresh_inode(inode, fattr);
+	if (status) {
+		dfprintk(PAGECACHE, "nfs_revalidate_inode: (%s/%Lu) refresh failed, error=%d\n",
+			 inode->i_sb->s_id,
+			 (unsigned long long)NFS_FILEID(inode), status);
+		goto err_out;
+	}
+
+	if (nfsi->cache_validity & NFS_INO_INVALID_ACL)
+		nfs_zap_acl_cache(inode);
+
+	nfs_setsecurity(inode, fattr, label);
+
+	dfprintk(PAGECACHE, "NFS: (%s/%Lu) revalidation complete\n",
+		inode->i_sb->s_id,
+		(unsigned long long)NFS_FILEID(inode));
+
+err_out:
+	nfs4_label_free(label);
+out:
+	nfs_free_fattr(fattr);
+	trace_nfs_revalidate_inode_exit(inode, status);
+	return status;
+}
+
+int nfs_attribute_cache_expired(struct inode *inode)
+{
+	if (nfs_have_delegated_attributes(inode))
+		return 0;
+	return nfs_attribute_timeout(inode);
+}
+
+/**
+ * nfs_revalidate_inode - Revalidate the inode attributes
+ * @server: pointer to nfs_server struct
+ * @inode: pointer to inode struct
+ *
+ * Updates inode attribute information by retrieving the data from the server.
+ */
+int nfs_revalidate_inode(struct nfs_server *server, struct inode *inode)
+{
+	if (!nfs_need_revalidate_inode(inode))
+		return NFS_STALE(inode) ? -ESTALE : 0;
+	return __nfs_revalidate_inode(server, inode);
+}
+EXPORT_SYMBOL_GPL(nfs_revalidate_inode);
+
+static int nfs_invalidate_mapping(struct inode *inode, struct address_space *mapping)
+{
+	struct nfs_inode *nfsi = NFS_I(inode);
+	int ret;
+
+	if (mapping->nrpages != 0) {
+		if (S_ISREG(inode->i_mode)) {
+			ret = nfs_sync_mapping(mapping);
+			if (ret < 0)
+				return ret;
+		}
+		ret = invalidate_inode_pages2(mapping);
+		if (ret < 0)
+			return ret;
+	}
+	if (S_ISDIR(inode->i_mode)) {
+		spin_lock(&inode->i_lock);
+		memset(nfsi->cookieverf, 0, sizeof(nfsi->cookieverf));
+		spin_unlock(&inode->i_lock);
+	}
+	nfs_inc_stats(inode, NFSIOS_DATAINVALIDATE);
+	nfs_fscache_wait_on_invalidate(inode);
+
+	dfprintk(PAGECACHE, "NFS: (%s/%Lu) data cache invalidated\n",
+			inode->i_sb->s_id,
+			(unsigned long long)NFS_FILEID(inode));
+	return 0;
+}
+
+bool nfs_mapping_need_revalidate_inode(struct inode *inode)
+{
+	return nfs_check_cache_invalid(inode, NFS_INO_REVAL_PAGECACHE) ||
+		NFS_STALE(inode);
+}
+
+int nfs_revalidate_mapping_rcu(struct inode *inode)
+{
+	struct nfs_inode *nfsi = NFS_I(inode);
+	unsigned long *bitlock = &nfsi->flags;
+	int ret = 0;
+
+	if (IS_SWAPFILE(inode))
+		goto out;
+	if (nfs_mapping_need_revalidate_inode(inode)) {
+		ret = -ECHILD;
+		goto out;
+	}
+	spin_lock(&inode->i_lock);
+	if (test_bit(NFS_INO_INVALIDATING, bitlock) ||
+	    (nfsi->cache_validity & NFS_INO_INVALID_DATA))
+		ret = -ECHILD;
+	spin_unlock(&inode->i_lock);
+out:
+	return ret;
+}
+
+/**
+ * nfs_revalidate_mapping - Revalidate the pagecache
+ * @inode: pointer to host inode
+ * @mapping: pointer to mapping
+ */
+int nfs_revalidate_mapping(struct inode *inode,
+		struct address_space *mapping)
+{
+	struct nfs_inode *nfsi = NFS_I(inode);
+	unsigned long *bitlock = &nfsi->flags;
+	int ret = 0;
+
+	/* swapfiles are not supposed to be shared. */
+	if (IS_SWAPFILE(inode))
+		goto out;
+
+	if (nfs_mapping_need_revalidate_inode(inode)) {
+		ret = __nfs_revalidate_inode(NFS_SERVER(inode), inode);
+		if (ret < 0)
+			goto out;
+	}
+
+	/*
+	 * We must clear NFS_INO_INVALID_DATA first to ensure that
+	 * invalidations that come in while we're shooting down the mappings
+	 * are respected. But, that leaves a race window where one revalidator
+	 * can clear the flag, and then another checks it before the mapping
+	 * gets invalidated. Fix that by serializing access to this part of
+	 * the function.
+	 *
+	 * At the same time, we need to allow other tasks to see whether we
+	 * might be in the middle of invalidating the pages, so we only set
+	 * the bit lock here if it looks like we're going to be doing that.
+	 */
+	for (;;) {
+		ret = wait_on_bit_action(bitlock, NFS_INO_INVALIDATING,
+					 nfs_wait_bit_killable, TASK_KILLABLE);
+		if (ret)
+			goto out;
+		spin_lock(&inode->i_lock);
+		if (test_bit(NFS_INO_INVALIDATING, bitlock)) {
+			spin_unlock(&inode->i_lock);
+			continue;
+		}
+		if (nfsi->cache_validity & NFS_INO_INVALID_DATA)
+			break;
+		spin_unlock(&inode->i_lock);
+		goto out;
+	}
+
+	set_bit(NFS_INO_INVALIDATING, bitlock);
+	smp_wmb();
+	nfsi->cache_validity &= ~(NFS_INO_INVALID_DATA|
+			NFS_INO_DATA_INVAL_DEFER);
+	spin_unlock(&inode->i_lock);
+	trace_nfs_invalidate_mapping_enter(inode);
+	ret = nfs_invalidate_mapping(inode, mapping);
+	trace_nfs_invalidate_mapping_exit(inode, ret);
+
+	clear_bit_unlock(NFS_INO_INVALIDATING, bitlock);
+	smp_mb__after_atomic();
+	wake_up_bit(bitlock, NFS_INO_INVALIDATING);
+out:
+	return ret;
+}
+
+static bool nfs_file_has_writers(struct nfs_inode *nfsi)
+{
+	struct inode *inode = &nfsi->vfs_inode;
+
+	if (!S_ISREG(inode->i_mode))
+		return false;
+	if (list_empty(&nfsi->open_files))
+		return false;
+	return inode_is_open_for_write(inode);
+}
+
+static bool nfs_file_has_buffered_writers(struct nfs_inode *nfsi)
+{
+	return nfs_file_has_writers(nfsi) && nfs_file_io_is_buffered(nfsi);
+}
+
+static void nfs_wcc_update_inode(struct inode *inode, struct nfs_fattr *fattr)
+{
+	struct timespec64 ts;
+
+	if ((fattr->valid & NFS_ATTR_FATTR_PRECHANGE)
+			&& (fattr->valid & NFS_ATTR_FATTR_CHANGE)
+			&& inode_eq_iversion_raw(inode, fattr->pre_change_attr)) {
+		inode_set_iversion_raw(inode, fattr->change_attr);
+		if (S_ISDIR(inode->i_mode))
+			nfs_set_cache_invalid(inode, NFS_INO_INVALID_DATA);
+		else if (nfs_server_capable(inode, NFS_CAP_XATTR))
+			nfs_set_cache_invalid(inode, NFS_INO_INVALID_XATTR);
+	}
+	/* If we have atomic WCC data, we may update some attributes */
+	ts = inode->i_ctime;
+	if ((fattr->valid & NFS_ATTR_FATTR_PRECTIME)
+			&& (fattr->valid & NFS_ATTR_FATTR_CTIME)
+			&& timespec64_equal(&ts, &fattr->pre_ctime)) {
+		inode->i_ctime = fattr->ctime;
+	}
+
+	ts = inode->i_mtime;
+	if ((fattr->valid & NFS_ATTR_FATTR_PREMTIME)
+			&& (fattr->valid & NFS_ATTR_FATTR_MTIME)
+			&& timespec64_equal(&ts, &fattr->pre_mtime)) {
+		inode->i_mtime = fattr->mtime;
+		if (S_ISDIR(inode->i_mode))
+			nfs_set_cache_invalid(inode, NFS_INO_INVALID_DATA);
+	}
+	if ((fattr->valid & NFS_ATTR_FATTR_PRESIZE)
+			&& (fattr->valid & NFS_ATTR_FATTR_SIZE)
+			&& i_size_read(inode) == nfs_size_to_loff_t(fattr->pre_size)
+			&& !nfs_have_writebacks(inode)) {
+		i_size_write(inode, nfs_size_to_loff_t(fattr->size));
+	}
+}
+
+/**
+ * nfs_check_inode_attributes - verify consistency of the inode attribute cache
+ * @inode: pointer to inode
+ * @fattr: updated attributes
+ *
+ * Verifies the attribute cache. If we have just changed the attributes,
+ * so that fattr carries weak cache consistency data, then it may
+ * also update the ctime/mtime/change_attribute.
+ */
+static int nfs_check_inode_attributes(struct inode *inode, struct nfs_fattr *fattr)
+{
+	struct nfs_inode *nfsi = NFS_I(inode);
+	loff_t cur_size, new_isize;
+	unsigned long invalid = 0;
+	struct timespec64 ts;
+
+	if (NFS_PROTO(inode)->have_delegation(inode, FMODE_READ))
+		return 0;
+
+	if (!(fattr->valid & NFS_ATTR_FATTR_FILEID)) {
+		/* Only a mounted-on-fileid? Just exit */
+		if (fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID)
+			return 0;
+	/* Has the inode gone and changed behind our back? */
+	} else if (nfsi->fileid != fattr->fileid) {
+		/* Is this perhaps the mounted-on fileid? */
+		if ((fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID) &&
+		    nfsi->fileid == fattr->mounted_on_fileid)
+			return 0;
+		return -ESTALE;
+	}
+	if ((fattr->valid & NFS_ATTR_FATTR_TYPE) && inode_wrong_type(inode, fattr->mode))
+		return -ESTALE;
+
+
+	if (!nfs_file_has_buffered_writers(nfsi)) {
+		/* Verify a few of the more important attributes */
+		if ((fattr->valid & NFS_ATTR_FATTR_CHANGE) != 0 && !inode_eq_iversion_raw(inode, fattr->change_attr))
+			invalid |= NFS_INO_INVALID_CHANGE
+				| NFS_INO_REVAL_PAGECACHE;
+
+		ts = inode->i_mtime;
+		if ((fattr->valid & NFS_ATTR_FATTR_MTIME) && !timespec64_equal(&ts, &fattr->mtime))
+			invalid |= NFS_INO_INVALID_MTIME;
+
+		ts = inode->i_ctime;
+		if ((fattr->valid & NFS_ATTR_FATTR_CTIME) && !timespec64_equal(&ts, &fattr->ctime))
+			invalid |= NFS_INO_INVALID_CTIME;
+
+		if (fattr->valid & NFS_ATTR_FATTR_SIZE) {
+			cur_size = i_size_read(inode);
+			new_isize = nfs_size_to_loff_t(fattr->size);
+			if (cur_size != new_isize)
+				invalid |= NFS_INO_INVALID_SIZE
+					| NFS_INO_REVAL_PAGECACHE;
+		}
+	}
+
+	/* Have any file permissions changed? */
+	if ((fattr->valid & NFS_ATTR_FATTR_MODE) && (inode->i_mode & S_IALLUGO) != (fattr->mode & S_IALLUGO))
+		invalid |= NFS_INO_INVALID_ACCESS
+			| NFS_INO_INVALID_ACL
+			| NFS_INO_INVALID_OTHER;
+	if ((fattr->valid & NFS_ATTR_FATTR_OWNER) && !uid_eq(inode->i_uid, fattr->uid))
+		invalid |= NFS_INO_INVALID_ACCESS
+			| NFS_INO_INVALID_ACL
+			| NFS_INO_INVALID_OTHER;
+	if ((fattr->valid & NFS_ATTR_FATTR_GROUP) && !gid_eq(inode->i_gid, fattr->gid))
+		invalid |= NFS_INO_INVALID_ACCESS
+			| NFS_INO_INVALID_ACL
+			| NFS_INO_INVALID_OTHER;
+
+	/* Has the link count changed? */
+	if ((fattr->valid & NFS_ATTR_FATTR_NLINK) && inode->i_nlink != fattr->nlink)
+		invalid |= NFS_INO_INVALID_OTHER;
+
+	ts = inode->i_atime;
+	if ((fattr->valid & NFS_ATTR_FATTR_ATIME) && !timespec64_equal(&ts, &fattr->atime))
+		invalid |= NFS_INO_INVALID_ATIME;
+
+	if (invalid != 0)
+		nfs_set_cache_invalid(inode, invalid);
+
+	nfsi->read_cache_jiffies = fattr->time_start;
+	return 0;
+}
+
+static atomic_long_t nfs_attr_generation_counter;
+
+static unsigned long nfs_read_attr_generation_counter(void)
+{
+	return atomic_long_read(&nfs_attr_generation_counter);
+}
+
+unsigned long nfs_inc_attr_generation_counter(void)
+{
+	return atomic_long_inc_return(&nfs_attr_generation_counter);
+}
+EXPORT_SYMBOL_GPL(nfs_inc_attr_generation_counter);
+
+void nfs_fattr_init(struct nfs_fattr *fattr)
+{
+	fattr->valid = 0;
+	fattr->time_start = jiffies;
+	fattr->gencount = nfs_inc_attr_generation_counter();
+	fattr->owner_name = NULL;
+	fattr->group_name = NULL;
+}
+EXPORT_SYMBOL_GPL(nfs_fattr_init);
+
+/**
+ * nfs_fattr_set_barrier
+ * @fattr: attributes
+ *
+ * Used to set a barrier after an attribute was updated. This
+ * barrier ensures that older attributes from RPC calls that may
+ * have raced with our update cannot clobber these new values.
+ * Note that you are still responsible for ensuring that other
+ * operations which change the attribute on the server do not
+ * collide.
+ */
+void nfs_fattr_set_barrier(struct nfs_fattr *fattr)
+{
+	fattr->gencount = nfs_inc_attr_generation_counter();
+}
+
+struct nfs_fattr *nfs_alloc_fattr(void)
+{
+	struct nfs_fattr *fattr;
+
+	fattr = kmalloc(sizeof(*fattr), GFP_NOFS);
+	if (fattr != NULL)
+		nfs_fattr_init(fattr);
+	return fattr;
+}
+EXPORT_SYMBOL_GPL(nfs_alloc_fattr);
+
+struct nfs_fh *nfs_alloc_fhandle(void)
+{
+	struct nfs_fh *fh;
+
+	fh = kmalloc(sizeof(struct nfs_fh), GFP_NOFS);
+	if (fh != NULL)
+		fh->size = 0;
+	return fh;
+}
+EXPORT_SYMBOL_GPL(nfs_alloc_fhandle);
+
+#ifdef NFS_DEBUG
+/*
+ * _nfs_display_fhandle_hash - calculate the crc32 hash for the filehandle
+ *                             in the same way that wireshark does
+ *
+ * @fh: file handle
+ *
+ * For debugging only.
+ */
+u32 _nfs_display_fhandle_hash(const struct nfs_fh *fh)
+{
+	/* wireshark uses 32-bit AUTODIN crc and does a bitwise
+	 * not on the result */
+	return nfs_fhandle_hash(fh);
+}
+EXPORT_SYMBOL_GPL(_nfs_display_fhandle_hash);
+
+/*
+ * _nfs_display_fhandle - display an NFS file handle on the console
+ *
+ * @fh: file handle to display
+ * @caption: display caption
+ *
+ * For debugging only.
+ */
+void _nfs_display_fhandle(const struct nfs_fh *fh, const char *caption)
+{
+	unsigned short i;
+
+	if (fh == NULL || fh->size == 0) {
+		printk(KERN_DEFAULT "%s at %p is empty\n", caption, fh);
+		return;
+	}
+
+	printk(KERN_DEFAULT "%s at %p is %u bytes, crc: 0x%08x:\n",
+	       caption, fh, fh->size, _nfs_display_fhandle_hash(fh));
+	for (i = 0; i < fh->size; i += 16) {
+		__be32 *pos = (__be32 *)&fh->data[i];
+
+		switch ((fh->size - i - 1) >> 2) {
+		case 0:
+			printk(KERN_DEFAULT " %08x\n",
+				be32_to_cpup(pos));
+			break;
+		case 1:
+			printk(KERN_DEFAULT " %08x %08x\n",
+				be32_to_cpup(pos), be32_to_cpup(pos + 1));
+			break;
+		case 2:
+			printk(KERN_DEFAULT " %08x %08x %08x\n",
+				be32_to_cpup(pos), be32_to_cpup(pos + 1),
+				be32_to_cpup(pos + 2));
+			break;
+		default:
+			printk(KERN_DEFAULT " %08x %08x %08x %08x\n",
+				be32_to_cpup(pos), be32_to_cpup(pos + 1),
+				be32_to_cpup(pos + 2), be32_to_cpup(pos + 3));
+		}
+	}
+}
+EXPORT_SYMBOL_GPL(_nfs_display_fhandle);
+#endif
+
+/**
+ * nfs_inode_attrs_need_update - check if the inode attributes need updating
+ * @inode: pointer to inode
+ * @fattr: attributes
+ *
+ * Attempt to divine whether or not an RPC call reply carrying stale
+ * attributes got scheduled after another call carrying updated ones.
+ *
+ * To do so, the function first assumes that a more recent ctime means
+ * that the attributes in fattr are newer, however it also attempt to
+ * catch the case where ctime either didn't change, or went backwards
+ * (if someone reset the clock on the server) by looking at whether
+ * or not this RPC call was started after the inode was last updated.
+ * Note also the check for wraparound of 'attr_gencount'
+ *
+ * The function returns 'true' if it thinks the attributes in 'fattr' are
+ * more recent than the ones cached in the inode.
+ *
+ */
+static int nfs_inode_attrs_need_update(const struct inode *inode, const struct nfs_fattr *fattr)
+{
+	unsigned long attr_gencount = NFS_I(inode)->attr_gencount;
+
+	return (long)(fattr->gencount - attr_gencount) > 0 ||
+	       (long)(attr_gencount - nfs_read_attr_generation_counter()) > 0;
+}
+
+static int nfs_refresh_inode_locked(struct inode *inode, struct nfs_fattr *fattr)
+{
+	int ret;
+
+	trace_nfs_refresh_inode_enter(inode);
+
+	if (nfs_inode_attrs_need_update(inode, fattr))
+		ret = nfs_update_inode(inode, fattr);
+	else
+		ret = nfs_check_inode_attributes(inode, fattr);
+
+	trace_nfs_refresh_inode_exit(inode, ret);
+	return ret;
+}
+
+/**
+ * nfs_refresh_inode - try to update the inode attribute cache
+ * @inode: pointer to inode
+ * @fattr: updated attributes
+ *
+ * Check that an RPC call that returned attributes has not overlapped with
+ * other recent updates of the inode metadata, then decide whether it is
+ * safe to do a full update of the inode attributes, or whether just to
+ * call nfs_check_inode_attributes.
+ */
+int nfs_refresh_inode(struct inode *inode, struct nfs_fattr *fattr)
+{
+	int status;
+
+	if ((fattr->valid & NFS_ATTR_FATTR) == 0)
+		return 0;
+	spin_lock(&inode->i_lock);
+	status = nfs_refresh_inode_locked(inode, fattr);
+	spin_unlock(&inode->i_lock);
+
+	return status;
+}
+EXPORT_SYMBOL_GPL(nfs_refresh_inode);
+
+static int nfs_post_op_update_inode_locked(struct inode *inode,
+		struct nfs_fattr *fattr, unsigned int invalid)
+{
+	if (S_ISDIR(inode->i_mode))
+		invalid |= NFS_INO_INVALID_DATA;
+	nfs_set_cache_invalid(inode, invalid);
+	if ((fattr->valid & NFS_ATTR_FATTR) == 0)
+		return 0;
+	return nfs_refresh_inode_locked(inode, fattr);
+}
+
+/**
+ * nfs_post_op_update_inode - try to update the inode attribute cache
+ * @inode: pointer to inode
+ * @fattr: updated attributes
+ *
+ * After an operation that has changed the inode metadata, mark the
+ * attribute cache as being invalid, then try to update it.
+ *
+ * NB: if the server didn't return any post op attributes, this
+ * function will force the retrieval of attributes before the next
+ * NFS request.  Thus it should be used only for operations that
+ * are expected to change one or more attributes, to avoid
+ * unnecessary NFS requests and trips through nfs_update_inode().
+ */
+int nfs_post_op_update_inode(struct inode *inode, struct nfs_fattr *fattr)
+{
+	int status;
+
+	spin_lock(&inode->i_lock);
+	nfs_fattr_set_barrier(fattr);
+	status = nfs_post_op_update_inode_locked(inode, fattr,
+			NFS_INO_INVALID_CHANGE
+			| NFS_INO_INVALID_CTIME
+			| NFS_INO_REVAL_FORCED);
+	spin_unlock(&inode->i_lock);
+
+	return status;
+}
+EXPORT_SYMBOL_GPL(nfs_post_op_update_inode);
+
+/**
+ * nfs_post_op_update_inode_force_wcc_locked - update the inode attribute cache
+ * @inode: pointer to inode
+ * @fattr: updated attributes
+ *
+ * After an operation that has changed the inode metadata, mark the
+ * attribute cache as being invalid, then try to update it. Fake up
+ * weak cache consistency data, if none exist.
+ *
+ * This function is mainly designed to be used by the ->write_done() functions.
+ */
+int nfs_post_op_update_inode_force_wcc_locked(struct inode *inode, struct nfs_fattr *fattr)
+{
+	int status;
+
+	/* Don't do a WCC update if these attributes are already stale */
+	if ((fattr->valid & NFS_ATTR_FATTR) == 0 ||
+			!nfs_inode_attrs_need_update(inode, fattr)) {
+		fattr->valid &= ~(NFS_ATTR_FATTR_PRECHANGE
+				| NFS_ATTR_FATTR_PRESIZE
+				| NFS_ATTR_FATTR_PREMTIME
+				| NFS_ATTR_FATTR_PRECTIME);
+		goto out_noforce;
+	}
+	if ((fattr->valid & NFS_ATTR_FATTR_CHANGE) != 0 &&
+			(fattr->valid & NFS_ATTR_FATTR_PRECHANGE) == 0) {
+		fattr->pre_change_attr = inode_peek_iversion_raw(inode);
+		fattr->valid |= NFS_ATTR_FATTR_PRECHANGE;
+	}
+	if ((fattr->valid & NFS_ATTR_FATTR_CTIME) != 0 &&
+			(fattr->valid & NFS_ATTR_FATTR_PRECTIME) == 0) {
+		fattr->pre_ctime = inode->i_ctime;
+		fattr->valid |= NFS_ATTR_FATTR_PRECTIME;
+	}
+	if ((fattr->valid & NFS_ATTR_FATTR_MTIME) != 0 &&
+			(fattr->valid & NFS_ATTR_FATTR_PREMTIME) == 0) {
+		fattr->pre_mtime = inode->i_mtime;
+		fattr->valid |= NFS_ATTR_FATTR_PREMTIME;
+	}
+	if ((fattr->valid & NFS_ATTR_FATTR_SIZE) != 0 &&
+			(fattr->valid & NFS_ATTR_FATTR_PRESIZE) == 0) {
+		fattr->pre_size = i_size_read(inode);
+		fattr->valid |= NFS_ATTR_FATTR_PRESIZE;
+	}
+out_noforce:
+	status = nfs_post_op_update_inode_locked(inode, fattr,
+			NFS_INO_INVALID_CHANGE
+			| NFS_INO_INVALID_CTIME
+			| NFS_INO_INVALID_MTIME
+			| NFS_INO_INVALID_BLOCKS);
+	return status;
+}
+
+/**
+ * nfs_post_op_update_inode_force_wcc - try to update the inode attribute cache
+ * @inode: pointer to inode
+ * @fattr: updated attributes
+ *
+ * After an operation that has changed the inode metadata, mark the
+ * attribute cache as being invalid, then try to update it. Fake up
+ * weak cache consistency data, if none exist.
+ *
+ * This function is mainly designed to be used by the ->write_done() functions.
+ */
+int nfs_post_op_update_inode_force_wcc(struct inode *inode, struct nfs_fattr *fattr)
+{
+	int status;
+
+	spin_lock(&inode->i_lock);
+	nfs_fattr_set_barrier(fattr);
+	status = nfs_post_op_update_inode_force_wcc_locked(inode, fattr);
+	spin_unlock(&inode->i_lock);
+	return status;
+}
+EXPORT_SYMBOL_GPL(nfs_post_op_update_inode_force_wcc);
+
+
+/*
+ * Many nfs protocol calls return the new file attributes after
+ * an operation.  Here we update the inode to reflect the state
+ * of the server's inode.
+ *
+ * This is a bit tricky because we have to make sure all dirty pages
+ * have been sent off to the server before calling invalidate_inode_pages.
+ * To make sure no other process adds more write requests while we try
+ * our best to flush them, we make them sleep during the attribute refresh.
+ *
+ * A very similar scenario holds for the dir cache.
+ */
+static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr)
+{
+	struct nfs_server *server;
+	struct nfs_inode *nfsi = NFS_I(inode);
+	loff_t cur_isize, new_isize;
+	unsigned long invalid = 0;
+	unsigned long now = jiffies;
+	unsigned long save_cache_validity;
+	bool have_writers = nfs_file_has_buffered_writers(nfsi);
+	bool cache_revalidated = true;
+	bool attr_changed = false;
+	bool have_delegation;
+
+	dfprintk(VFS, "NFS: %s(%s/%lu fh_crc=0x%08x ct=%d info=0x%x)\n",
+			__func__, inode->i_sb->s_id, inode->i_ino,
+			nfs_display_fhandle_hash(NFS_FH(inode)),
+			atomic_read(&inode->i_count), fattr->valid);
+
+	if (!(fattr->valid & NFS_ATTR_FATTR_FILEID)) {
+		/* Only a mounted-on-fileid? Just exit */
+		if (fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID)
+			return 0;
+	/* Has the inode gone and changed behind our back? */
+	} else if (nfsi->fileid != fattr->fileid) {
+		/* Is this perhaps the mounted-on fileid? */
+		if ((fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID) &&
+		    nfsi->fileid == fattr->mounted_on_fileid)
+			return 0;
+		printk(KERN_ERR "NFS: server %s error: fileid changed\n"
+			"fsid %s: expected fileid 0x%Lx, got 0x%Lx\n",
+			NFS_SERVER(inode)->nfs_client->cl_hostname,
+			inode->i_sb->s_id, (long long)nfsi->fileid,
+			(long long)fattr->fileid);
+		goto out_err;
+	}
+
+	/*
+	 * Make sure the inode's type hasn't changed.
+	 */
+	if ((fattr->valid & NFS_ATTR_FATTR_TYPE) && inode_wrong_type(inode, fattr->mode)) {
+		/*
+		* Big trouble! The inode has become a different object.
+		*/
+		printk(KERN_DEBUG "NFS: %s: inode %lu mode changed, %07o to %07o\n",
+				__func__, inode->i_ino, inode->i_mode, fattr->mode);
+		goto out_err;
+	}
+
+	server = NFS_SERVER(inode);
+	/* Update the fsid? */
+	if (S_ISDIR(inode->i_mode) && (fattr->valid & NFS_ATTR_FATTR_FSID) &&
+			!nfs_fsid_equal(&server->fsid, &fattr->fsid) &&
+			!IS_AUTOMOUNT(inode))
+		server->fsid = fattr->fsid;
+
+	/* Save the delegation state before clearing cache_validity */
+	have_delegation = nfs_have_delegated_attributes(inode);
+
+	/*
+	 * Update the read time so we don't revalidate too often.
+	 */
+	nfsi->read_cache_jiffies = fattr->time_start;
+
+	save_cache_validity = nfsi->cache_validity;
+	nfsi->cache_validity &= ~(NFS_INO_INVALID_ATTR
+			| NFS_INO_INVALID_ATIME
+			| NFS_INO_REVAL_FORCED
+			| NFS_INO_REVAL_PAGECACHE
+			| NFS_INO_INVALID_BLOCKS);
+
+	/* Do atomic weak cache consistency updates */
+	nfs_wcc_update_inode(inode, fattr);
+
+	if (pnfs_layoutcommit_outstanding(inode)) {
+		nfsi->cache_validity |=
+			save_cache_validity &
+			(NFS_INO_INVALID_CHANGE | NFS_INO_INVALID_CTIME |
+			 NFS_INO_INVALID_MTIME | NFS_INO_INVALID_SIZE |
+			 NFS_INO_REVAL_FORCED);
+		cache_revalidated = false;
+	}
+
+	/* More cache consistency checks */
+	if (fattr->valid & NFS_ATTR_FATTR_CHANGE) {
+		if (!inode_eq_iversion_raw(inode, fattr->change_attr)) {
+			/* Could it be a race with writeback? */
+			if (!(have_writers || have_delegation)) {
+				invalid |= NFS_INO_INVALID_DATA
+					| NFS_INO_INVALID_ACCESS
+					| NFS_INO_INVALID_ACL
+					| NFS_INO_INVALID_XATTR;
+				/* Force revalidate of all attributes */
+				save_cache_validity |= NFS_INO_INVALID_CTIME
+					| NFS_INO_INVALID_MTIME
+					| NFS_INO_INVALID_SIZE
+					| NFS_INO_INVALID_OTHER;
+				if (S_ISDIR(inode->i_mode))
+					nfs_force_lookup_revalidate(inode);
+				dprintk("NFS: change_attr change on server for file %s/%ld\n",
+						inode->i_sb->s_id,
+						inode->i_ino);
+			} else if (!have_delegation)
+				nfsi->cache_validity |= NFS_INO_DATA_INVAL_DEFER;
+			inode_set_iversion_raw(inode, fattr->change_attr);
+			attr_changed = true;
+		}
+	} else {
+		nfsi->cache_validity |= save_cache_validity &
+				(NFS_INO_INVALID_CHANGE
+				| NFS_INO_REVAL_PAGECACHE
+				| NFS_INO_REVAL_FORCED);
+		cache_revalidated = false;
+	}
+
+	if (fattr->valid & NFS_ATTR_FATTR_MTIME) {
+		inode->i_mtime = fattr->mtime;
+	} else if (server->caps & NFS_CAP_MTIME) {
+		nfsi->cache_validity |= save_cache_validity &
+				(NFS_INO_INVALID_MTIME
+				| NFS_INO_REVAL_FORCED);
+		cache_revalidated = false;
+	}
+
+	if (fattr->valid & NFS_ATTR_FATTR_CTIME) {
+		inode->i_ctime = fattr->ctime;
+	} else if (server->caps & NFS_CAP_CTIME) {
+		nfsi->cache_validity |= save_cache_validity &
+				(NFS_INO_INVALID_CTIME
+				| NFS_INO_REVAL_FORCED);
+		cache_revalidated = false;
+	}
+
+	/* Check if our cached file size is stale */
+	if (fattr->valid & NFS_ATTR_FATTR_SIZE) {
+		new_isize = nfs_size_to_loff_t(fattr->size);
+		cur_isize = i_size_read(inode);
+		if (new_isize != cur_isize && !have_delegation) {
+			/* Do we perhaps have any outstanding writes, or has
+			 * the file grown beyond our last write? */
+			if (!nfs_have_writebacks(inode) || new_isize > cur_isize) {
+				i_size_write(inode, new_isize);
+				if (!have_writers)
+					invalid |= NFS_INO_INVALID_DATA;
+				attr_changed = true;
+			}
+			dprintk("NFS: isize change on server for file %s/%ld "
+					"(%Ld to %Ld)\n",
+					inode->i_sb->s_id,
+					inode->i_ino,
+					(long long)cur_isize,
+					(long long)new_isize);
+		}
+	} else {
+		nfsi->cache_validity |= save_cache_validity &
+				(NFS_INO_INVALID_SIZE
+				| NFS_INO_REVAL_PAGECACHE
+				| NFS_INO_REVAL_FORCED);
+		cache_revalidated = false;
+	}
+
+
+	if (fattr->valid & NFS_ATTR_FATTR_ATIME)
+		inode->i_atime = fattr->atime;
+	else if (server->caps & NFS_CAP_ATIME) {
+		nfsi->cache_validity |= save_cache_validity &
+				(NFS_INO_INVALID_ATIME
+				| NFS_INO_REVAL_FORCED);
+		cache_revalidated = false;
+	}
+
+	if (fattr->valid & NFS_ATTR_FATTR_MODE) {
+		if ((inode->i_mode & S_IALLUGO) != (fattr->mode & S_IALLUGO)) {
+			umode_t newmode = inode->i_mode & S_IFMT;
+			newmode |= fattr->mode & S_IALLUGO;
+			inode->i_mode = newmode;
+			invalid |= NFS_INO_INVALID_ACCESS
+				| NFS_INO_INVALID_ACL;
+			attr_changed = true;
+		}
+	} else if (server->caps & NFS_CAP_MODE) {
+		nfsi->cache_validity |= save_cache_validity &
+				(NFS_INO_INVALID_OTHER
+				| NFS_INO_REVAL_FORCED);
+		cache_revalidated = false;
+	}
+
+	if (fattr->valid & NFS_ATTR_FATTR_OWNER) {
+		if (!uid_eq(inode->i_uid, fattr->uid)) {
+			invalid |= NFS_INO_INVALID_ACCESS
+				| NFS_INO_INVALID_ACL;
+			inode->i_uid = fattr->uid;
+			attr_changed = true;
+		}
+	} else if (server->caps & NFS_CAP_OWNER) {
+		nfsi->cache_validity |= save_cache_validity &
+				(NFS_INO_INVALID_OTHER
+				| NFS_INO_REVAL_FORCED);
+		cache_revalidated = false;
+	}
+
+	if (fattr->valid & NFS_ATTR_FATTR_GROUP) {
+		if (!gid_eq(inode->i_gid, fattr->gid)) {
+			invalid |= NFS_INO_INVALID_ACCESS
+				| NFS_INO_INVALID_ACL;
+			inode->i_gid = fattr->gid;
+			attr_changed = true;
+		}
+	} else if (server->caps & NFS_CAP_OWNER_GROUP) {
+		nfsi->cache_validity |= save_cache_validity &
+				(NFS_INO_INVALID_OTHER
+				| NFS_INO_REVAL_FORCED);
+		cache_revalidated = false;
+	}
+
+	if (fattr->valid & NFS_ATTR_FATTR_NLINK) {
+		if (inode->i_nlink != fattr->nlink) {
+			if (S_ISDIR(inode->i_mode))
+				invalid |= NFS_INO_INVALID_DATA;
+			set_nlink(inode, fattr->nlink);
+			attr_changed = true;
+		}
+	} else if (server->caps & NFS_CAP_NLINK) {
+		nfsi->cache_validity |= save_cache_validity &
+				(NFS_INO_INVALID_OTHER
+				| NFS_INO_REVAL_FORCED);
+		cache_revalidated = false;
+	}
+
+	if (fattr->valid & NFS_ATTR_FATTR_SPACE_USED) {
+		/*
+		 * report the blocks in 512byte units
+		 */
+		inode->i_blocks = nfs_calc_block_size(fattr->du.nfs3.used);
+	} else if (fattr->valid & NFS_ATTR_FATTR_BLOCKS_USED)
+		inode->i_blocks = fattr->du.nfs2.blocks;
+	else {
+		nfsi->cache_validity |= save_cache_validity &
+				(NFS_INO_INVALID_BLOCKS
+				| NFS_INO_REVAL_FORCED);
+		cache_revalidated = false;
+	}
+
+	/* Update attrtimeo value if we're out of the unstable period */
+	if (attr_changed) {
+		invalid &= ~NFS_INO_INVALID_ATTR;
+		nfs_inc_stats(inode, NFSIOS_ATTRINVALIDATE);
+		nfsi->attrtimeo = NFS_MINATTRTIMEO(inode);
+		nfsi->attrtimeo_timestamp = now;
+		/* Set barrier to be more recent than all outstanding updates */
+		nfsi->attr_gencount = nfs_inc_attr_generation_counter();
+	} else {
+		if (cache_revalidated) {
+			if (!time_in_range_open(now, nfsi->attrtimeo_timestamp,
+				nfsi->attrtimeo_timestamp + nfsi->attrtimeo)) {
+				nfsi->attrtimeo <<= 1;
+				if (nfsi->attrtimeo > NFS_MAXATTRTIMEO(inode))
+					nfsi->attrtimeo = NFS_MAXATTRTIMEO(inode);
+			}
+			nfsi->attrtimeo_timestamp = now;
+		}
+		/* Set the barrier to be more recent than this fattr */
+		if ((long)(fattr->gencount - nfsi->attr_gencount) > 0)
+			nfsi->attr_gencount = fattr->gencount;
+	}
+
+	/* Don't invalidate the data if we were to blame */
+	if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode)
+				|| S_ISLNK(inode->i_mode)))
+		invalid &= ~NFS_INO_INVALID_DATA;
+	nfs_set_cache_invalid(inode, invalid);
+
+	return 0;
+ out_err:
+	/*
+	 * No need to worry about unhashing the dentry, as the
+	 * lookup validation will know that the inode is bad.
+	 * (But we fall through to invalidate the caches.)
+	 */
+	nfs_set_inode_stale_locked(inode);
+	return -ESTALE;
+}
+
+struct inode *nfs_alloc_inode(struct super_block *sb)
+{
+	struct nfs_inode *nfsi;
+	nfsi = kmem_cache_alloc(nfs_inode_cachep, GFP_KERNEL);
+	if (!nfsi)
+		return NULL;
+	nfsi->flags = 0UL;
+	nfsi->cache_validity = 0UL;
+#if IS_ENABLED(CONFIG_NFS_V4)
+	nfsi->nfs4_acl = NULL;
+#endif /* CONFIG_NFS_V4 */
+#ifdef CONFIG_NFS_V4_2
+	nfsi->xattr_cache = NULL;
+#endif
+	return &nfsi->vfs_inode;
+}
+EXPORT_SYMBOL_GPL(nfs_alloc_inode);
+
+void nfs_free_inode(struct inode *inode)
+{
+	kmem_cache_free(nfs_inode_cachep, NFS_I(inode));
+}
+EXPORT_SYMBOL_GPL(nfs_free_inode);
+
+static inline void nfs4_init_once(struct nfs_inode *nfsi)
+{
+#if IS_ENABLED(CONFIG_NFS_V4)
+	INIT_LIST_HEAD(&nfsi->open_states);
+	nfsi->delegation = NULL;
+	init_rwsem(&nfsi->rwsem);
+	nfsi->layout = NULL;
+#endif
+}
+
+static void init_once(void *foo)
+{
+	struct nfs_inode *nfsi = (struct nfs_inode *) foo;
+
+	inode_init_once(&nfsi->vfs_inode);
+	INIT_LIST_HEAD(&nfsi->open_files);
+	INIT_LIST_HEAD(&nfsi->access_cache_entry_lru);
+	INIT_LIST_HEAD(&nfsi->access_cache_inode_lru);
+	INIT_LIST_HEAD(&nfsi->commit_info.list);
+	atomic_long_set(&nfsi->nrequests, 0);
+	atomic_long_set(&nfsi->commit_info.ncommit, 0);
+	atomic_set(&nfsi->commit_info.rpcs_out, 0);
+	init_rwsem(&nfsi->rmdir_sem);
+	mutex_init(&nfsi->commit_mutex);
+	nfs4_init_once(nfsi);
+	nfsi->cache_change_attribute = 0;
+}
+
+static int __init nfs_init_inodecache(void)
+{
+	nfs_inode_cachep = kmem_cache_create("nfs_inode_cache",
+					     sizeof(struct nfs_inode),
+					     0, (SLAB_RECLAIM_ACCOUNT|
+						SLAB_MEM_SPREAD|SLAB_ACCOUNT),
+					     init_once);
+	if (nfs_inode_cachep == NULL)
+		return -ENOMEM;
+
+	return 0;
+}
+
+static void nfs_destroy_inodecache(void)
+{
+	/*
+	 * Make sure all delayed rcu free inodes are flushed before we
+	 * destroy cache.
+	 */
+	rcu_barrier();
+	kmem_cache_destroy(nfs_inode_cachep);
+}
+
+struct workqueue_struct *nfsiod_workqueue;
+EXPORT_SYMBOL_GPL(nfsiod_workqueue);
+
+/*
+ * start up the nfsiod workqueue
+ */
+static int nfsiod_start(void)
+{
+	struct workqueue_struct *wq;
+	dprintk("RPC:       creating workqueue nfsiod\n");
+	wq = alloc_workqueue("nfsiod", WQ_MEM_RECLAIM | WQ_UNBOUND, 0);
+	if (wq == NULL)
+		return -ENOMEM;
+	nfsiod_workqueue = wq;
+	return 0;
+}
+
+/*
+ * Destroy the nfsiod workqueue
+ */
+static void nfsiod_stop(void)
+{
+	struct workqueue_struct *wq;
+
+	wq = nfsiod_workqueue;
+	if (wq == NULL)
+		return;
+	nfsiod_workqueue = NULL;
+	destroy_workqueue(wq);
+}
+
+unsigned int nfs_net_id;
+EXPORT_SYMBOL_GPL(nfs_net_id);
+
+static int nfs_net_init(struct net *net)
+{
+	nfs_clients_init(net);
+	return nfs_fs_proc_net_init(net);
+}
+
+static void nfs_net_exit(struct net *net)
+{
+	nfs_fs_proc_net_exit(net);
+	nfs_clients_exit(net);
+}
+
+static struct pernet_operations nfs_net_ops = {
+	.init = nfs_net_init,
+	.exit = nfs_net_exit,
+	.id   = &nfs_net_id,
+	.size = sizeof(struct nfs_net),
+};
+
+/*
+ * Initialize NFS
+ */
+static int __init init_nfs_fs(void)
+{
+	int err;
+
+	err = nfs_sysfs_init();
+	if (err < 0)
+		goto out10;
+
+	err = register_pernet_subsys(&nfs_net_ops);
+	if (err < 0)
+		goto out9;
+
+	err = nfs_fscache_register();
+	if (err < 0)
+		goto out8;
+
+	err = nfsiod_start();
+	if (err)
+		goto out7;
+
+	err = nfs_fs_proc_init();
+	if (err)
+		goto out6;
+
+	err = nfs_init_nfspagecache();
+	if (err)
+		goto out5;
+
+	err = nfs_init_inodecache();
+	if (err)
+		goto out4;
+
+	err = nfs_init_readpagecache();
+	if (err)
+		goto out3;
+
+	err = nfs_init_writepagecache();
+	if (err)
+		goto out2;
+
+	err = nfs_init_directcache();
+	if (err)
+		goto out1;
+
+	rpc_proc_register(&init_net, &nfs_rpcstat);
+
+	err = register_nfs_fs();
+	if (err)
+		goto out0;
+
+	return 0;
+out0:
+	rpc_proc_unregister(&init_net, "nfs");
+	nfs_destroy_directcache();
+out1:
+	nfs_destroy_writepagecache();
+out2:
+	nfs_destroy_readpagecache();
+out3:
+	nfs_destroy_inodecache();
+out4:
+	nfs_destroy_nfspagecache();
+out5:
+	nfs_fs_proc_exit();
+out6:
+	nfsiod_stop();
+out7:
+	nfs_fscache_unregister();
+out8:
+	unregister_pernet_subsys(&nfs_net_ops);
+out9:
+	nfs_sysfs_exit();
+out10:
+	return err;
+}
+
+static void __exit exit_nfs_fs(void)
+{
+	nfs_destroy_directcache();
+	nfs_destroy_writepagecache();
+	nfs_destroy_readpagecache();
+	nfs_destroy_inodecache();
+	nfs_destroy_nfspagecache();
+	nfs_fscache_unregister();
+	unregister_pernet_subsys(&nfs_net_ops);
+	rpc_proc_unregister(&init_net, "nfs");
+	unregister_nfs_fs();
+	nfs_fs_proc_exit();
+	nfsiod_stop();
+	nfs_sysfs_exit();
+}
+
+/* Not quite true; I just maintain it */
+MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>");
+MODULE_LICENSE("GPL");
+module_param(enable_ino64, bool, 0644);
+
+module_init(init_nfs_fs)
+module_exit(exit_nfs_fs)
diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
new file mode 100644
index 000000000..a7e0970b5
--- /dev/null
+++ b/fs/nfs/internal.h
@@ -0,0 +1,852 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * NFS internal definitions
+ */
+
+#include "nfs4_fs.h"
+#include <linux/fs_context.h>
+#include <linux/security.h>
+#include <linux/crc32.h>
+#include <linux/sunrpc/addr.h>
+#include <linux/nfs_page.h>
+#include <linux/wait_bit.h>
+
+#define NFS_SB_MASK (SB_RDONLY|SB_NOSUID|SB_NODEV|SB_NOEXEC|SB_SYNCHRONOUS)
+
+extern const struct export_operations nfs_export_ops;
+
+struct nfs_string;
+struct nfs_pageio_descriptor;
+
+static inline void nfs_attr_check_mountpoint(struct super_block *parent, struct nfs_fattr *fattr)
+{
+	if (!nfs_fsid_equal(&NFS_SB(parent)->fsid, &fattr->fsid))
+		fattr->valid |= NFS_ATTR_FATTR_MOUNTPOINT;
+}
+
+static inline int nfs_attr_use_mounted_on_fileid(struct nfs_fattr *fattr)
+{
+	if (((fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID) == 0) ||
+	    (((fattr->valid & NFS_ATTR_FATTR_MOUNTPOINT) == 0) &&
+	     ((fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL) == 0)))
+		return 0;
+	return 1;
+}
+
+static inline bool nfs_lookup_is_soft_revalidate(const struct dentry *dentry)
+{
+	if (!(NFS_SB(dentry->d_sb)->flags & NFS_MOUNT_SOFTREVAL))
+		return false;
+	if (!d_is_positive(dentry) || !NFS_FH(d_inode(dentry))->size)
+		return false;
+	return true;
+}
+
+static inline fmode_t flags_to_mode(int flags)
+{
+	fmode_t res = (__force fmode_t)flags & FMODE_EXEC;
+	if ((flags & O_ACCMODE) != O_WRONLY)
+		res |= FMODE_READ;
+	if ((flags & O_ACCMODE) != O_RDONLY)
+		res |= FMODE_WRITE;
+	return res;
+}
+
+/*
+ * Note: RFC 1813 doesn't limit the number of auth flavors that
+ * a server can return, so make something up.
+ */
+#define NFS_MAX_SECFLAVORS	(12)
+
+/*
+ * Value used if the user did not specify a port value.
+ */
+#define NFS_UNSPEC_PORT		(-1)
+
+#define NFS_UNSPEC_RETRANS	(UINT_MAX)
+#define NFS_UNSPEC_TIMEO	(UINT_MAX)
+
+/*
+ * Maximum number of pages that readdir can use for creating
+ * a vmapped array of pages.
+ */
+#define NFS_MAX_READDIR_PAGES 8
+
+struct nfs_client_initdata {
+	unsigned long init_flags;
+	const char *hostname;			/* Hostname of the server */
+	const struct sockaddr *addr;		/* Address of the server */
+	const char *nodename;			/* Hostname of the client */
+	const char *ip_addr;			/* IP address of the client */
+	size_t addrlen;
+	struct nfs_subversion *nfs_mod;
+	int proto;
+	u32 minorversion;
+	unsigned int nconnect;
+	struct net *net;
+	const struct rpc_timeout *timeparms;
+	const struct cred *cred;
+};
+
+/*
+ * In-kernel mount arguments
+ */
+struct nfs_fs_context {
+	bool			internal;
+	bool			skip_reconfig_option_check;
+	bool			need_mount;
+	bool			sloppy;
+	unsigned int		flags;		/* NFS{,4}_MOUNT_* flags */
+	unsigned int		rsize, wsize;
+	unsigned int		timeo, retrans;
+	unsigned int		acregmin, acregmax;
+	unsigned int		acdirmin, acdirmax;
+	unsigned int		namlen;
+	unsigned int		options;
+	unsigned int		bsize;
+	struct nfs_auth_info	auth_info;
+	rpc_authflavor_t	selected_flavor;
+	char			*client_address;
+	unsigned int		version;
+	unsigned int		minorversion;
+	char			*fscache_uniq;
+	unsigned short		protofamily;
+	unsigned short		mountfamily;
+
+	struct {
+		union {
+			struct sockaddr	address;
+			struct sockaddr_storage	_address;
+		};
+		size_t			addrlen;
+		char			*hostname;
+		u32			version;
+		int			port;
+		unsigned short		protocol;
+	} mount_server;
+
+	struct {
+		union {
+			struct sockaddr	address;
+			struct sockaddr_storage	_address;
+		};
+		size_t			addrlen;
+		char			*hostname;
+		char			*export_path;
+		int			port;
+		unsigned short		protocol;
+		unsigned short		nconnect;
+		unsigned short		export_path_len;
+	} nfs_server;
+
+	struct nfs_fh		*mntfh;
+	struct nfs_server	*server;
+	struct nfs_subversion	*nfs_mod;
+
+	/* Information for a cloned mount. */
+	struct nfs_clone_mount {
+		struct super_block	*sb;
+		struct dentry		*dentry;
+		struct nfs_fattr	*fattr;
+		unsigned int		inherited_bsize;
+	} clone_data;
+};
+
+#define nfs_errorf(fc, fmt, ...) ((fc)->log.log ?		\
+	errorf(fc, fmt, ## __VA_ARGS__) :			\
+	({ dprintk(fmt "\n", ## __VA_ARGS__); }))
+
+#define nfs_ferrorf(fc, fac, fmt, ...) ((fc)->log.log ?		\
+	errorf(fc, fmt, ## __VA_ARGS__) :			\
+	({ dfprintk(fac, fmt "\n", ## __VA_ARGS__); }))
+
+#define nfs_invalf(fc, fmt, ...) ((fc)->log.log ?		\
+	invalf(fc, fmt, ## __VA_ARGS__) :			\
+	({ dprintk(fmt "\n", ## __VA_ARGS__);  -EINVAL; }))
+
+#define nfs_finvalf(fc, fac, fmt, ...) ((fc)->log.log ?		\
+	invalf(fc, fmt, ## __VA_ARGS__) :			\
+	({ dfprintk(fac, fmt "\n", ## __VA_ARGS__);  -EINVAL; }))
+
+#define nfs_warnf(fc, fmt, ...) ((fc)->log.log ?		\
+	warnf(fc, fmt, ## __VA_ARGS__) :			\
+	({ dprintk(fmt "\n", ## __VA_ARGS__); }))
+
+#define nfs_fwarnf(fc, fac, fmt, ...) ((fc)->log.log ?		\
+	warnf(fc, fmt, ## __VA_ARGS__) :			\
+	({ dfprintk(fac, fmt "\n", ## __VA_ARGS__); }))
+
+static inline struct nfs_fs_context *nfs_fc2context(const struct fs_context *fc)
+{
+	return fc->fs_private;
+}
+
+/* mount_clnt.c */
+struct nfs_mount_request {
+	struct sockaddr		*sap;
+	size_t			salen;
+	char			*hostname;
+	char			*dirpath;
+	u32			version;
+	unsigned short		protocol;
+	struct nfs_fh		*fh;
+	int			noresvport;
+	unsigned int		*auth_flav_len;
+	rpc_authflavor_t	*auth_flavs;
+	struct net		*net;
+};
+
+extern int nfs_mount(struct nfs_mount_request *info);
+extern void nfs_umount(const struct nfs_mount_request *info);
+
+/* client.c */
+extern const struct rpc_program nfs_program;
+extern void nfs_clients_init(struct net *net);
+extern void nfs_clients_exit(struct net *net);
+extern struct nfs_client *nfs_alloc_client(const struct nfs_client_initdata *);
+int nfs_create_rpc_client(struct nfs_client *, const struct nfs_client_initdata *, rpc_authflavor_t);
+struct nfs_client *nfs_get_client(const struct nfs_client_initdata *);
+int nfs_probe_fsinfo(struct nfs_server *server, struct nfs_fh *, struct nfs_fattr *);
+void nfs_server_insert_lists(struct nfs_server *);
+void nfs_server_remove_lists(struct nfs_server *);
+void nfs_init_timeout_values(struct rpc_timeout *to, int proto, int timeo, int retrans);
+int nfs_init_server_rpcclient(struct nfs_server *, const struct rpc_timeout *t,
+		rpc_authflavor_t);
+struct nfs_server *nfs_alloc_server(void);
+void nfs_server_copy_userdata(struct nfs_server *, struct nfs_server *);
+
+extern void nfs_put_client(struct nfs_client *);
+extern void nfs_free_client(struct nfs_client *);
+extern struct nfs_client *nfs4_find_client_ident(struct net *, int);
+extern struct nfs_client *
+nfs4_find_client_sessionid(struct net *, const struct sockaddr *,
+				struct nfs4_sessionid *, u32);
+extern struct nfs_server *nfs_create_server(struct fs_context *);
+extern struct nfs_server *nfs4_create_server(struct fs_context *);
+extern struct nfs_server *nfs4_create_referral_server(struct fs_context *);
+extern int nfs4_update_server(struct nfs_server *server, const char *hostname,
+					struct sockaddr *sap, size_t salen,
+					struct net *net);
+extern void nfs_free_server(struct nfs_server *server);
+extern struct nfs_server *nfs_clone_server(struct nfs_server *,
+					   struct nfs_fh *,
+					   struct nfs_fattr *,
+					   rpc_authflavor_t);
+extern bool nfs_client_init_is_complete(const struct nfs_client *clp);
+extern int nfs_client_init_status(const struct nfs_client *clp);
+extern int nfs_wait_client_init_complete(const struct nfs_client *clp);
+extern void nfs_mark_client_ready(struct nfs_client *clp, int state);
+extern struct nfs_client *nfs4_set_ds_client(struct nfs_server *mds_srv,
+					     const struct sockaddr *ds_addr,
+					     int ds_addrlen, int ds_proto,
+					     unsigned int ds_timeo,
+					     unsigned int ds_retrans,
+					     u32 minor_version);
+extern struct rpc_clnt *nfs4_find_or_create_ds_client(struct nfs_client *,
+						struct inode *);
+extern struct nfs_client *nfs3_set_ds_client(struct nfs_server *mds_srv,
+			const struct sockaddr *ds_addr, int ds_addrlen,
+			int ds_proto, unsigned int ds_timeo,
+			unsigned int ds_retrans);
+#ifdef CONFIG_PROC_FS
+extern int __init nfs_fs_proc_init(void);
+extern void nfs_fs_proc_exit(void);
+extern int nfs_fs_proc_net_init(struct net *net);
+extern void nfs_fs_proc_net_exit(struct net *net);
+#else
+static inline int nfs_fs_proc_net_init(struct net *net)
+{
+	return 0;
+}
+static inline void nfs_fs_proc_net_exit(struct net *net)
+{
+}
+static inline int nfs_fs_proc_init(void)
+{
+	return 0;
+}
+static inline void nfs_fs_proc_exit(void)
+{
+}
+#endif
+
+/* callback_xdr.c */
+extern const struct svc_version nfs4_callback_version1;
+extern const struct svc_version nfs4_callback_version4;
+
+/* fs_context.c */
+extern struct file_system_type nfs_fs_type;
+
+/* pagelist.c */
+extern int __init nfs_init_nfspagecache(void);
+extern void nfs_destroy_nfspagecache(void);
+extern int __init nfs_init_readpagecache(void);
+extern void nfs_destroy_readpagecache(void);
+extern int __init nfs_init_writepagecache(void);
+extern void nfs_destroy_writepagecache(void);
+
+extern int __init nfs_init_directcache(void);
+extern void nfs_destroy_directcache(void);
+extern void nfs_pgheader_init(struct nfs_pageio_descriptor *desc,
+			      struct nfs_pgio_header *hdr,
+			      void (*release)(struct nfs_pgio_header *hdr));
+void nfs_set_pgio_error(struct nfs_pgio_header *hdr, int error, loff_t pos);
+int nfs_iocounter_wait(struct nfs_lock_context *l_ctx);
+
+extern const struct nfs_pageio_ops nfs_pgio_rw_ops;
+struct nfs_pgio_header *nfs_pgio_header_alloc(const struct nfs_rw_ops *);
+void nfs_pgio_header_free(struct nfs_pgio_header *);
+int nfs_generic_pgio(struct nfs_pageio_descriptor *, struct nfs_pgio_header *);
+int nfs_initiate_pgio(struct rpc_clnt *clnt, struct nfs_pgio_header *hdr,
+		      const struct cred *cred, const struct nfs_rpc_ops *rpc_ops,
+		      const struct rpc_call_ops *call_ops, int how, int flags);
+void nfs_free_request(struct nfs_page *req);
+struct nfs_pgio_mirror *
+nfs_pgio_current_mirror(struct nfs_pageio_descriptor *desc);
+
+static inline bool nfs_match_open_context(const struct nfs_open_context *ctx1,
+		const struct nfs_open_context *ctx2)
+{
+	return cred_fscmp(ctx1->cred, ctx2->cred) == 0 && ctx1->state == ctx2->state;
+}
+
+/* nfs2xdr.c */
+extern const struct rpc_procinfo nfs_procedures[];
+extern int nfs2_decode_dirent(struct xdr_stream *,
+				struct nfs_entry *, bool);
+
+/* nfs3xdr.c */
+extern const struct rpc_procinfo nfs3_procedures[];
+extern int nfs3_decode_dirent(struct xdr_stream *,
+				struct nfs_entry *, bool);
+
+/* nfs4xdr.c */
+#if IS_ENABLED(CONFIG_NFS_V4)
+extern int nfs4_decode_dirent(struct xdr_stream *,
+				struct nfs_entry *, bool);
+#endif
+#ifdef CONFIG_NFS_V4_1
+extern const u32 nfs41_maxread_overhead;
+extern const u32 nfs41_maxwrite_overhead;
+extern const u32 nfs41_maxgetdevinfo_overhead;
+#endif
+
+/* nfs4proc.c */
+#if IS_ENABLED(CONFIG_NFS_V4)
+extern const struct rpc_procinfo nfs4_procedures[];
+#endif
+
+#ifdef CONFIG_NFS_V4_SECURITY_LABEL
+extern struct nfs4_label *nfs4_label_alloc(struct nfs_server *server, gfp_t flags);
+static inline struct nfs4_label *
+nfs4_label_copy(struct nfs4_label *dst, struct nfs4_label *src)
+{
+	if (!dst || !src)
+		return NULL;
+
+	if (src->len > NFS4_MAXLABELLEN)
+		return NULL;
+
+	dst->lfs = src->lfs;
+	dst->pi = src->pi;
+	dst->len = src->len;
+	memcpy(dst->label, src->label, src->len);
+
+	return dst;
+}
+static inline void nfs4_label_free(struct nfs4_label *label)
+{
+	if (label) {
+		kfree(label->label);
+		kfree(label);
+	}
+	return;
+}
+
+static inline void nfs_zap_label_cache_locked(struct nfs_inode *nfsi)
+{
+	if (nfs_server_capable(&nfsi->vfs_inode, NFS_CAP_SECURITY_LABEL))
+		nfsi->cache_validity |= NFS_INO_INVALID_LABEL;
+}
+#else
+static inline struct nfs4_label *nfs4_label_alloc(struct nfs_server *server, gfp_t flags) { return NULL; }
+static inline void nfs4_label_free(void *label) {}
+static inline void nfs_zap_label_cache_locked(struct nfs_inode *nfsi)
+{
+}
+static inline struct nfs4_label *
+nfs4_label_copy(struct nfs4_label *dst, struct nfs4_label *src)
+{
+	return NULL;
+}
+#endif /* CONFIG_NFS_V4_SECURITY_LABEL */
+
+/* proc.c */
+void nfs_close_context(struct nfs_open_context *ctx, int is_sync);
+extern struct nfs_client *nfs_init_client(struct nfs_client *clp,
+			   const struct nfs_client_initdata *);
+
+/* dir.c */
+extern void nfs_advise_use_readdirplus(struct inode *dir);
+extern void nfs_force_use_readdirplus(struct inode *dir);
+extern unsigned long nfs_access_cache_count(struct shrinker *shrink,
+					    struct shrink_control *sc);
+extern unsigned long nfs_access_cache_scan(struct shrinker *shrink,
+					   struct shrink_control *sc);
+struct dentry *nfs_lookup(struct inode *, struct dentry *, unsigned int);
+int nfs_create(struct inode *, struct dentry *, umode_t, bool);
+int nfs_mkdir(struct inode *, struct dentry *, umode_t);
+int nfs_rmdir(struct inode *, struct dentry *);
+int nfs_unlink(struct inode *, struct dentry *);
+int nfs_symlink(struct inode *, struct dentry *, const char *);
+int nfs_link(struct dentry *, struct inode *, struct dentry *);
+int nfs_mknod(struct inode *, struct dentry *, umode_t, dev_t);
+int nfs_rename(struct inode *, struct dentry *,
+	       struct inode *, struct dentry *, unsigned int);
+
+/* file.c */
+int nfs_file_fsync(struct file *file, loff_t start, loff_t end, int datasync);
+loff_t nfs_file_llseek(struct file *, loff_t, int);
+ssize_t nfs_file_read(struct kiocb *, struct iov_iter *);
+int nfs_file_mmap(struct file *, struct vm_area_struct *);
+ssize_t nfs_file_write(struct kiocb *, struct iov_iter *);
+int nfs_file_release(struct inode *, struct file *);
+int nfs_lock(struct file *, int, struct file_lock *);
+int nfs_flock(struct file *, int, struct file_lock *);
+int nfs_check_flags(int);
+
+/* inode.c */
+extern struct workqueue_struct *nfsiod_workqueue;
+extern struct inode *nfs_alloc_inode(struct super_block *sb);
+extern void nfs_free_inode(struct inode *);
+extern int nfs_write_inode(struct inode *, struct writeback_control *);
+extern int nfs_drop_inode(struct inode *);
+extern void nfs_clear_inode(struct inode *);
+extern void nfs_evict_inode(struct inode *);
+void nfs_zap_acl_cache(struct inode *inode);
+extern bool nfs_check_cache_invalid(struct inode *, unsigned long);
+extern int nfs_wait_bit_killable(struct wait_bit_key *key, int mode);
+extern int nfs_wait_atomic_killable(atomic_t *p, unsigned int mode);
+
+/* super.c */
+extern const struct super_operations nfs_sops;
+bool nfs_auth_info_match(const struct nfs_auth_info *, rpc_authflavor_t);
+int nfs_try_get_tree(struct fs_context *);
+int nfs_get_tree_common(struct fs_context *);
+void nfs_kill_super(struct super_block *);
+
+extern struct rpc_stat nfs_rpcstat;
+
+extern int __init register_nfs_fs(void);
+extern void __exit unregister_nfs_fs(void);
+extern bool nfs_sb_active(struct super_block *sb);
+extern void nfs_sb_deactive(struct super_block *sb);
+extern int nfs_client_for_each_server(struct nfs_client *clp,
+				      int (*fn)(struct nfs_server *, void *),
+				      void *data);
+/* io.c */
+extern void nfs_start_io_read(struct inode *inode);
+extern void nfs_end_io_read(struct inode *inode);
+extern void nfs_start_io_write(struct inode *inode);
+extern void nfs_end_io_write(struct inode *inode);
+extern void nfs_start_io_direct(struct inode *inode);
+extern void nfs_end_io_direct(struct inode *inode);
+
+static inline bool nfs_file_io_is_buffered(struct nfs_inode *nfsi)
+{
+	return test_bit(NFS_INO_ODIRECT, &nfsi->flags) == 0;
+}
+
+/* namespace.c */
+#define NFS_PATH_CANONICAL 1
+extern char *nfs_path(char **p, struct dentry *dentry,
+		      char *buffer, ssize_t buflen, unsigned flags);
+extern struct vfsmount *nfs_d_automount(struct path *path);
+int nfs_submount(struct fs_context *, struct nfs_server *);
+int nfs_do_submount(struct fs_context *);
+
+/* getroot.c */
+extern int nfs_get_root(struct super_block *s, struct fs_context *fc);
+#if IS_ENABLED(CONFIG_NFS_V4)
+extern int nfs4_get_rootfh(struct nfs_server *server, struct nfs_fh *mntfh, bool);
+#endif
+
+struct nfs_pgio_completion_ops;
+/* read.c */
+extern void nfs_pageio_init_read(struct nfs_pageio_descriptor *pgio,
+			struct inode *inode, bool force_mds,
+			const struct nfs_pgio_completion_ops *compl_ops);
+extern void nfs_read_prepare(struct rpc_task *task, void *calldata);
+extern void nfs_pageio_reset_read_mds(struct nfs_pageio_descriptor *pgio);
+
+/* super.c */
+void nfs_umount_begin(struct super_block *);
+int  nfs_statfs(struct dentry *, struct kstatfs *);
+int  nfs_show_options(struct seq_file *, struct dentry *);
+int  nfs_show_devname(struct seq_file *, struct dentry *);
+int  nfs_show_path(struct seq_file *, struct dentry *);
+int  nfs_show_stats(struct seq_file *, struct dentry *);
+int  nfs_reconfigure(struct fs_context *);
+
+/* write.c */
+extern void nfs_pageio_init_write(struct nfs_pageio_descriptor *pgio,
+			struct inode *inode, int ioflags, bool force_mds,
+			const struct nfs_pgio_completion_ops *compl_ops);
+extern void nfs_pageio_reset_write_mds(struct nfs_pageio_descriptor *pgio);
+extern void nfs_commit_free(struct nfs_commit_data *p);
+extern void nfs_write_prepare(struct rpc_task *task, void *calldata);
+extern void nfs_commit_prepare(struct rpc_task *task, void *calldata);
+extern int nfs_initiate_commit(struct rpc_clnt *clnt,
+			       struct nfs_commit_data *data,
+			       const struct nfs_rpc_ops *nfs_ops,
+			       const struct rpc_call_ops *call_ops,
+			       int how, int flags);
+extern void nfs_init_commit(struct nfs_commit_data *data,
+			    struct list_head *head,
+			    struct pnfs_layout_segment *lseg,
+			    struct nfs_commit_info *cinfo);
+int nfs_scan_commit_list(struct list_head *src, struct list_head *dst,
+			 struct nfs_commit_info *cinfo, int max);
+unsigned long nfs_reqs_to_commit(struct nfs_commit_info *);
+int nfs_scan_commit(struct inode *inode, struct list_head *dst,
+		    struct nfs_commit_info *cinfo);
+void nfs_mark_request_commit(struct nfs_page *req,
+			     struct pnfs_layout_segment *lseg,
+			     struct nfs_commit_info *cinfo,
+			     u32 ds_commit_idx);
+int nfs_write_need_commit(struct nfs_pgio_header *);
+void nfs_writeback_update_inode(struct nfs_pgio_header *hdr);
+int nfs_generic_commit_list(struct inode *inode, struct list_head *head,
+			    int how, struct nfs_commit_info *cinfo);
+void nfs_retry_commit(struct list_head *page_list,
+		      struct pnfs_layout_segment *lseg,
+		      struct nfs_commit_info *cinfo,
+		      u32 ds_commit_idx);
+void nfs_commitdata_release(struct nfs_commit_data *data);
+void nfs_request_add_commit_list(struct nfs_page *req,
+				 struct nfs_commit_info *cinfo);
+void nfs_request_add_commit_list_locked(struct nfs_page *req,
+		struct list_head *dst,
+		struct nfs_commit_info *cinfo);
+void nfs_request_remove_commit_list(struct nfs_page *req,
+				    struct nfs_commit_info *cinfo);
+void nfs_init_cinfo(struct nfs_commit_info *cinfo,
+		    struct inode *inode,
+		    struct nfs_direct_req *dreq);
+int nfs_key_timeout_notify(struct file *filp, struct inode *inode);
+bool nfs_ctx_key_to_expire(struct nfs_open_context *ctx, struct inode *inode);
+void nfs_pageio_stop_mirroring(struct nfs_pageio_descriptor *pgio);
+
+int nfs_filemap_write_and_wait_range(struct address_space *mapping,
+		loff_t lstart, loff_t lend);
+
+#ifdef CONFIG_NFS_V4_1
+static inline void
+pnfs_bucket_clear_pnfs_ds_commit_verifiers(struct pnfs_commit_bucket *buckets,
+		unsigned int nbuckets)
+{
+	unsigned int i;
+
+	for (i = 0; i < nbuckets; i++)
+		buckets[i].direct_verf.committed = NFS_INVALID_STABLE_HOW;
+}
+static inline
+void nfs_clear_pnfs_ds_commit_verifiers(struct pnfs_ds_commit_info *cinfo)
+{
+	struct pnfs_commit_array *array;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(array, &cinfo->commits, cinfo_list)
+		pnfs_bucket_clear_pnfs_ds_commit_verifiers(array->buckets,
+				array->nbuckets);
+	rcu_read_unlock();
+}
+#else
+static inline
+void nfs_clear_pnfs_ds_commit_verifiers(struct pnfs_ds_commit_info *cinfo)
+{
+}
+#endif
+
+#ifdef CONFIG_MIGRATION
+extern int nfs_migrate_page(struct address_space *,
+		struct page *, struct page *, enum migrate_mode);
+#endif
+
+static inline int
+nfs_write_verifier_cmp(const struct nfs_write_verifier *v1,
+		const struct nfs_write_verifier *v2)
+{
+	return memcmp(v1->data, v2->data, sizeof(v1->data));
+}
+
+static inline bool
+nfs_write_match_verf(const struct nfs_writeverf *verf,
+		struct nfs_page *req)
+{
+	return verf->committed > NFS_UNSTABLE &&
+		!nfs_write_verifier_cmp(&req->wb_verf, &verf->verifier);
+}
+
+static inline gfp_t nfs_io_gfp_mask(void)
+{
+	if (current->flags & PF_WQ_WORKER)
+		return GFP_KERNEL | __GFP_NORETRY | __GFP_NOWARN;
+	return GFP_KERNEL;
+}
+
+/* unlink.c */
+extern struct rpc_task *
+nfs_async_rename(struct inode *old_dir, struct inode *new_dir,
+		 struct dentry *old_dentry, struct dentry *new_dentry,
+		 void (*complete)(struct rpc_task *, struct nfs_renamedata *));
+extern int nfs_sillyrename(struct inode *dir, struct dentry *dentry);
+
+/* direct.c */
+void nfs_init_cinfo_from_dreq(struct nfs_commit_info *cinfo,
+			      struct nfs_direct_req *dreq);
+extern ssize_t nfs_dreq_bytes_left(struct nfs_direct_req *dreq);
+
+/* nfs4proc.c */
+extern struct nfs_client *nfs4_init_client(struct nfs_client *clp,
+			    const struct nfs_client_initdata *);
+extern int nfs40_walk_client_list(struct nfs_client *clp,
+				struct nfs_client **result,
+				const struct cred *cred);
+extern int nfs41_walk_client_list(struct nfs_client *clp,
+				struct nfs_client **result,
+				const struct cred *cred);
+extern void nfs4_test_session_trunk(struct rpc_clnt *clnt,
+				struct rpc_xprt *xprt,
+				void *data);
+
+static inline struct inode *nfs_igrab_and_active(struct inode *inode)
+{
+	struct super_block *sb = inode->i_sb;
+
+	if (sb && nfs_sb_active(sb)) {
+		if (igrab(inode))
+			return inode;
+		nfs_sb_deactive(sb);
+	}
+	return NULL;
+}
+
+static inline void nfs_iput_and_deactive(struct inode *inode)
+{
+	if (inode != NULL) {
+		struct super_block *sb = inode->i_sb;
+
+		iput(inode);
+		nfs_sb_deactive(sb);
+	}
+}
+
+/*
+ * Determine the device name as a string
+ */
+static inline char *nfs_devname(struct dentry *dentry,
+				char *buffer, ssize_t buflen)
+{
+	char *dummy;
+	return nfs_path(&dummy, dentry, buffer, buflen, NFS_PATH_CANONICAL);
+}
+
+/*
+ * Determine the actual block size (and log2 thereof)
+ */
+static inline
+unsigned long nfs_block_bits(unsigned long bsize, unsigned char *nrbitsp)
+{
+	/* make sure blocksize is a power of two */
+	if ((bsize & (bsize - 1)) || nrbitsp) {
+		unsigned char	nrbits;
+
+		for (nrbits = 31; nrbits && !(bsize & (1 << nrbits)); nrbits--)
+			;
+		bsize = 1 << nrbits;
+		if (nrbitsp)
+			*nrbitsp = nrbits;
+	}
+
+	return bsize;
+}
+
+/*
+ * Calculate the number of 512byte blocks used.
+ */
+static inline blkcnt_t nfs_calc_block_size(u64 tsize)
+{
+	blkcnt_t used = (tsize + 511) >> 9;
+	return (used > ULONG_MAX) ? ULONG_MAX : used;
+}
+
+/*
+ * Compute and set NFS server blocksize
+ */
+static inline
+unsigned long nfs_block_size(unsigned long bsize, unsigned char *nrbitsp)
+{
+	if (bsize < NFS_MIN_FILE_IO_SIZE)
+		bsize = NFS_DEF_FILE_IO_SIZE;
+	else if (bsize >= NFS_MAX_FILE_IO_SIZE)
+		bsize = NFS_MAX_FILE_IO_SIZE;
+
+	return nfs_block_bits(bsize, nrbitsp);
+}
+
+/*
+ * Determine the maximum file size for a superblock
+ */
+static inline
+void nfs_super_set_maxbytes(struct super_block *sb, __u64 maxfilesize)
+{
+	sb->s_maxbytes = (loff_t)maxfilesize;
+	if (sb->s_maxbytes > MAX_LFS_FILESIZE || sb->s_maxbytes <= 0)
+		sb->s_maxbytes = MAX_LFS_FILESIZE;
+}
+
+/*
+ * Record the page as unstable (an extra writeback period) and mark its
+ * inode as dirty.
+ */
+static inline
+void nfs_mark_page_unstable(struct page *page, struct nfs_commit_info *cinfo)
+{
+	if (!cinfo->dreq) {
+		struct inode *inode = page_file_mapping(page)->host;
+
+		/* This page is really still in write-back - just that the
+		 * writeback is happening on the server now.
+		 */
+		inc_node_page_state(page, NR_WRITEBACK);
+		inc_wb_stat(&inode_to_bdi(inode)->wb, WB_WRITEBACK);
+		__mark_inode_dirty(inode, I_DIRTY_DATASYNC);
+	}
+}
+
+/*
+ * Determine the number of bytes of data the page contains
+ */
+static inline
+unsigned int nfs_page_length(struct page *page)
+{
+	loff_t i_size = i_size_read(page_file_mapping(page)->host);
+
+	if (i_size > 0) {
+		pgoff_t index = page_index(page);
+		pgoff_t end_index = (i_size - 1) >> PAGE_SHIFT;
+		if (index < end_index)
+			return PAGE_SIZE;
+		if (index == end_index)
+			return ((i_size - 1) & ~PAGE_MASK) + 1;
+	}
+	return 0;
+}
+
+/*
+ * Convert a umode to a dirent->d_type
+ */
+static inline
+unsigned char nfs_umode_to_dtype(umode_t mode)
+{
+	return (mode >> 12) & 15;
+}
+
+/*
+ * Determine the number of pages in an array of length 'len' and
+ * with a base offset of 'base'
+ */
+static inline
+unsigned int nfs_page_array_len(unsigned int base, size_t len)
+{
+	return ((unsigned long)len + (unsigned long)base +
+		PAGE_SIZE - 1) >> PAGE_SHIFT;
+}
+
+/*
+ * Convert a struct timespec64 into a 64-bit change attribute
+ *
+ * This does approximately the same thing as timespec64_to_ns(),
+ * but for calculation efficiency, we multiply the seconds by
+ * 1024*1024*1024.
+ */
+static inline
+u64 nfs_timespec_to_change_attr(const struct timespec64 *ts)
+{
+	return ((u64)ts->tv_sec << 30) + ts->tv_nsec;
+}
+
+#ifdef CONFIG_CRC32
+/**
+ * nfs_fhandle_hash - calculate the crc32 hash for the filehandle
+ * @fh - pointer to filehandle
+ *
+ * returns a crc32 hash for the filehandle that is compatible with
+ * the one displayed by "wireshark".
+ */
+static inline u32 nfs_fhandle_hash(const struct nfs_fh *fh)
+{
+	return ~crc32_le(0xFFFFFFFF, &fh->data[0], fh->size);
+}
+static inline u32 nfs_stateid_hash(const nfs4_stateid *stateid)
+{
+	return ~crc32_le(0xFFFFFFFF, &stateid->other[0],
+				NFS4_STATEID_OTHER_SIZE);
+}
+#else
+static inline u32 nfs_fhandle_hash(const struct nfs_fh *fh)
+{
+	return 0;
+}
+static inline u32 nfs_stateid_hash(nfs4_stateid *stateid)
+{
+	return 0;
+}
+#endif
+
+static inline bool nfs_error_is_fatal(int err)
+{
+	switch (err) {
+	case -ERESTARTSYS:
+	case -EINTR:
+	case -EACCES:
+	case -EDQUOT:
+	case -EFBIG:
+	case -EIO:
+	case -ENOSPC:
+	case -EROFS:
+	case -ESTALE:
+	case -E2BIG:
+	case -ENOMEM:
+	case -ETIMEDOUT:
+		return true;
+	default:
+		return false;
+	}
+}
+
+static inline bool nfs_error_is_fatal_on_server(int err)
+{
+	switch (err) {
+	case 0:
+	case -ERESTARTSYS:
+	case -EINTR:
+	case -ENOMEM:
+		return false;
+	}
+	return nfs_error_is_fatal(err);
+}
+
+/*
+ * Select between a default port value and a user-specified port value.
+ * If a zero value is set, then autobind will be used.
+ */
+static inline void nfs_set_port(struct sockaddr *sap, int *port,
+				const unsigned short default_port)
+{
+	if (*port == NFS_UNSPEC_PORT)
+		*port = default_port;
+
+	rpc_set_port(sap, *port);
+}
diff --git a/fs/nfs/io.c b/fs/nfs/io.c
new file mode 100644
index 000000000..5088fda9b
--- /dev/null
+++ b/fs/nfs/io.c
@@ -0,0 +1,148 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2016 Trond Myklebust
+ *
+ * I/O and data path helper functionality.
+ */
+
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/bitops.h>
+#include <linux/rwsem.h>
+#include <linux/fs.h>
+#include <linux/nfs_fs.h>
+
+#include "internal.h"
+
+/* Call with exclusively locked inode->i_rwsem */
+static void nfs_block_o_direct(struct nfs_inode *nfsi, struct inode *inode)
+{
+	if (test_bit(NFS_INO_ODIRECT, &nfsi->flags)) {
+		clear_bit(NFS_INO_ODIRECT, &nfsi->flags);
+		inode_dio_wait(inode);
+	}
+}
+
+/**
+ * nfs_start_io_read - declare the file is being used for buffered reads
+ * @inode: file inode
+ *
+ * Declare that a buffered read operation is about to start, and ensure
+ * that we block all direct I/O.
+ * On exit, the function ensures that the NFS_INO_ODIRECT flag is unset,
+ * and holds a shared lock on inode->i_rwsem to ensure that the flag
+ * cannot be changed.
+ * In practice, this means that buffered read operations are allowed to
+ * execute in parallel, thanks to the shared lock, whereas direct I/O
+ * operations need to wait to grab an exclusive lock in order to set
+ * NFS_INO_ODIRECT.
+ * Note that buffered writes and truncates both take a write lock on
+ * inode->i_rwsem, meaning that those are serialised w.r.t. the reads.
+ */
+void
+nfs_start_io_read(struct inode *inode)
+{
+	struct nfs_inode *nfsi = NFS_I(inode);
+	/* Be an optimist! */
+	down_read(&inode->i_rwsem);
+	if (test_bit(NFS_INO_ODIRECT, &nfsi->flags) == 0)
+		return;
+	up_read(&inode->i_rwsem);
+	/* Slow path.... */
+	down_write(&inode->i_rwsem);
+	nfs_block_o_direct(nfsi, inode);
+	downgrade_write(&inode->i_rwsem);
+}
+
+/**
+ * nfs_end_io_read - declare that the buffered read operation is done
+ * @inode: file inode
+ *
+ * Declare that a buffered read operation is done, and release the shared
+ * lock on inode->i_rwsem.
+ */
+void
+nfs_end_io_read(struct inode *inode)
+{
+	up_read(&inode->i_rwsem);
+}
+
+/**
+ * nfs_start_io_write - declare the file is being used for buffered writes
+ * @inode: file inode
+ *
+ * Declare that a buffered read operation is about to start, and ensure
+ * that we block all direct I/O.
+ */
+void
+nfs_start_io_write(struct inode *inode)
+{
+	down_write(&inode->i_rwsem);
+	nfs_block_o_direct(NFS_I(inode), inode);
+}
+
+/**
+ * nfs_end_io_write - declare that the buffered write operation is done
+ * @inode: file inode
+ *
+ * Declare that a buffered write operation is done, and release the
+ * lock on inode->i_rwsem.
+ */
+void
+nfs_end_io_write(struct inode *inode)
+{
+	up_write(&inode->i_rwsem);
+}
+
+/* Call with exclusively locked inode->i_rwsem */
+static void nfs_block_buffered(struct nfs_inode *nfsi, struct inode *inode)
+{
+	if (!test_bit(NFS_INO_ODIRECT, &nfsi->flags)) {
+		set_bit(NFS_INO_ODIRECT, &nfsi->flags);
+		nfs_sync_mapping(inode->i_mapping);
+	}
+}
+
+/**
+ * nfs_end_io_direct - declare the file is being used for direct i/o
+ * @inode: file inode
+ *
+ * Declare that a direct I/O operation is about to start, and ensure
+ * that we block all buffered I/O.
+ * On exit, the function ensures that the NFS_INO_ODIRECT flag is set,
+ * and holds a shared lock on inode->i_rwsem to ensure that the flag
+ * cannot be changed.
+ * In practice, this means that direct I/O operations are allowed to
+ * execute in parallel, thanks to the shared lock, whereas buffered I/O
+ * operations need to wait to grab an exclusive lock in order to clear
+ * NFS_INO_ODIRECT.
+ * Note that buffered writes and truncates both take a write lock on
+ * inode->i_rwsem, meaning that those are serialised w.r.t. O_DIRECT.
+ */
+void
+nfs_start_io_direct(struct inode *inode)
+{
+	struct nfs_inode *nfsi = NFS_I(inode);
+	/* Be an optimist! */
+	down_read(&inode->i_rwsem);
+	if (test_bit(NFS_INO_ODIRECT, &nfsi->flags) != 0)
+		return;
+	up_read(&inode->i_rwsem);
+	/* Slow path.... */
+	down_write(&inode->i_rwsem);
+	nfs_block_buffered(nfsi, inode);
+	downgrade_write(&inode->i_rwsem);
+}
+
+/**
+ * nfs_end_io_direct - declare that the direct i/o operation is done
+ * @inode: file inode
+ *
+ * Declare that a direct I/O operation is done, and release the shared
+ * lock on inode->i_rwsem.
+ */
+void
+nfs_end_io_direct(struct inode *inode)
+{
+	up_read(&inode->i_rwsem);
+}
diff --git a/fs/nfs/iostat.h b/fs/nfs/iostat.h
new file mode 100644
index 000000000..2ddaab1ac
--- /dev/null
+++ b/fs/nfs/iostat.h
@@ -0,0 +1,77 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ *  linux/fs/nfs/iostat.h
+ *
+ *  Declarations for NFS client per-mount statistics
+ *
+ *  Copyright (C) 2005, 2006 Chuck Lever <cel@netapp.com>
+ *
+ */
+
+#ifndef _NFS_IOSTAT
+#define _NFS_IOSTAT
+
+#include <linux/percpu.h>
+#include <linux/cache.h>
+#include <linux/nfs_iostat.h>
+
+struct nfs_iostats {
+	unsigned long long	bytes[__NFSIOS_BYTESMAX];
+#ifdef CONFIG_NFS_FSCACHE
+	unsigned long long	fscache[__NFSIOS_FSCACHEMAX];
+#endif
+	unsigned long		events[__NFSIOS_COUNTSMAX];
+} ____cacheline_aligned;
+
+static inline void nfs_inc_server_stats(const struct nfs_server *server,
+					enum nfs_stat_eventcounters stat)
+{
+	this_cpu_inc(server->io_stats->events[stat]);
+}
+
+static inline void nfs_inc_stats(const struct inode *inode,
+				 enum nfs_stat_eventcounters stat)
+{
+	nfs_inc_server_stats(NFS_SERVER(inode), stat);
+}
+
+static inline void nfs_add_server_stats(const struct nfs_server *server,
+					enum nfs_stat_bytecounters stat,
+					long addend)
+{
+	this_cpu_add(server->io_stats->bytes[stat], addend);
+}
+
+static inline void nfs_add_stats(const struct inode *inode,
+				 enum nfs_stat_bytecounters stat,
+				 long addend)
+{
+	nfs_add_server_stats(NFS_SERVER(inode), stat, addend);
+}
+
+#ifdef CONFIG_NFS_FSCACHE
+static inline void nfs_add_fscache_stats(struct inode *inode,
+					 enum nfs_stat_fscachecounters stat,
+					 long addend)
+{
+	this_cpu_add(NFS_SERVER(inode)->io_stats->fscache[stat], addend);
+}
+static inline void nfs_inc_fscache_stats(struct inode *inode,
+					 enum nfs_stat_fscachecounters stat)
+{
+	this_cpu_inc(NFS_SERVER(inode)->io_stats->fscache[stat]);
+}
+#endif
+
+static inline struct nfs_iostats __percpu *nfs_alloc_iostats(void)
+{
+	return alloc_percpu(struct nfs_iostats);
+}
+
+static inline void nfs_free_iostats(struct nfs_iostats __percpu *stats)
+{
+	if (stats != NULL)
+		free_percpu(stats);
+}
+
+#endif /* _NFS_IOSTAT */
diff --git a/fs/nfs/mount_clnt.c b/fs/nfs/mount_clnt.c
new file mode 100644
index 000000000..dda5c3e65
--- /dev/null
+++ b/fs/nfs/mount_clnt.c
@@ -0,0 +1,540 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * In-kernel MOUNT protocol client
+ *
+ * Copyright (C) 1997, Olaf Kirch <okir@monad.swb.de>
+ */
+
+#include <linux/types.h>
+#include <linux/socket.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/uio.h>
+#include <linux/net.h>
+#include <linux/in.h>
+#include <linux/sunrpc/clnt.h>
+#include <linux/sunrpc/sched.h>
+#include <linux/nfs_fs.h>
+#include "internal.h"
+
+#define NFSDBG_FACILITY	NFSDBG_MOUNT
+
+/*
+ * Defined by RFC 1094, section A.3; and RFC 1813, section 5.1.4
+ */
+#define MNTPATHLEN		(1024)
+
+/*
+ * XDR data type sizes
+ */
+#define encode_dirpath_sz	(1 + XDR_QUADLEN(MNTPATHLEN))
+#define MNT_status_sz		(1)
+#define MNT_fhandle_sz		XDR_QUADLEN(NFS2_FHSIZE)
+#define MNT_fhandlev3_sz	XDR_QUADLEN(NFS3_FHSIZE)
+#define MNT_authflav3_sz	(1 + NFS_MAX_SECFLAVORS)
+
+/*
+ * XDR argument and result sizes
+ */
+#define MNT_enc_dirpath_sz	encode_dirpath_sz
+#define MNT_dec_mountres_sz	(MNT_status_sz + MNT_fhandle_sz)
+#define MNT_dec_mountres3_sz	(MNT_status_sz + MNT_fhandlev3_sz + \
+				 MNT_authflav3_sz)
+
+/*
+ * Defined by RFC 1094, section A.5
+ */
+enum {
+	MOUNTPROC_NULL		= 0,
+	MOUNTPROC_MNT		= 1,
+	MOUNTPROC_DUMP		= 2,
+	MOUNTPROC_UMNT		= 3,
+	MOUNTPROC_UMNTALL	= 4,
+	MOUNTPROC_EXPORT	= 5,
+};
+
+/*
+ * Defined by RFC 1813, section 5.2
+ */
+enum {
+	MOUNTPROC3_NULL		= 0,
+	MOUNTPROC3_MNT		= 1,
+	MOUNTPROC3_DUMP		= 2,
+	MOUNTPROC3_UMNT		= 3,
+	MOUNTPROC3_UMNTALL	= 4,
+	MOUNTPROC3_EXPORT	= 5,
+};
+
+static const struct rpc_program mnt_program;
+
+/*
+ * Defined by OpenGroup XNFS Version 3W, chapter 8
+ */
+enum mountstat {
+	MNT_OK			= 0,
+	MNT_EPERM		= 1,
+	MNT_ENOENT		= 2,
+	MNT_EACCES		= 13,
+	MNT_EINVAL		= 22,
+};
+
+static struct {
+	u32 status;
+	int errno;
+} mnt_errtbl[] = {
+	{ .status = MNT_OK,			.errno = 0,		},
+	{ .status = MNT_EPERM,			.errno = -EPERM,	},
+	{ .status = MNT_ENOENT,			.errno = -ENOENT,	},
+	{ .status = MNT_EACCES,			.errno = -EACCES,	},
+	{ .status = MNT_EINVAL,			.errno = -EINVAL,	},
+};
+
+/*
+ * Defined by RFC 1813, section 5.1.5
+ */
+enum mountstat3 {
+	MNT3_OK			= 0,		/* no error */
+	MNT3ERR_PERM		= 1,		/* Not owner */
+	MNT3ERR_NOENT		= 2,		/* No such file or directory */
+	MNT3ERR_IO		= 5,		/* I/O error */
+	MNT3ERR_ACCES		= 13,		/* Permission denied */
+	MNT3ERR_NOTDIR		= 20,		/* Not a directory */
+	MNT3ERR_INVAL		= 22,		/* Invalid argument */
+	MNT3ERR_NAMETOOLONG	= 63,		/* Filename too long */
+	MNT3ERR_NOTSUPP		= 10004,	/* Operation not supported */
+	MNT3ERR_SERVERFAULT	= 10006,	/* A failure on the server */
+};
+
+static struct {
+	u32 status;
+	int errno;
+} mnt3_errtbl[] = {
+	{ .status = MNT3_OK,			.errno = 0,		},
+	{ .status = MNT3ERR_PERM,		.errno = -EPERM,	},
+	{ .status = MNT3ERR_NOENT,		.errno = -ENOENT,	},
+	{ .status = MNT3ERR_IO,			.errno = -EIO,		},
+	{ .status = MNT3ERR_ACCES,		.errno = -EACCES,	},
+	{ .status = MNT3ERR_NOTDIR,		.errno = -ENOTDIR,	},
+	{ .status = MNT3ERR_INVAL,		.errno = -EINVAL,	},
+	{ .status = MNT3ERR_NAMETOOLONG,	.errno = -ENAMETOOLONG,	},
+	{ .status = MNT3ERR_NOTSUPP,		.errno = -ENOTSUPP,	},
+	{ .status = MNT3ERR_SERVERFAULT,	.errno = -EREMOTEIO,	},
+};
+
+struct mountres {
+	int errno;
+	struct nfs_fh *fh;
+	unsigned int *auth_count;
+	rpc_authflavor_t *auth_flavors;
+};
+
+struct mnt_fhstatus {
+	u32 status;
+	struct nfs_fh *fh;
+};
+
+/**
+ * nfs_mount - Obtain an NFS file handle for the given host and path
+ * @info: pointer to mount request arguments
+ *
+ * Uses default timeout parameters specified by underlying transport. On
+ * successful return, the auth_flavs list and auth_flav_len will be populated
+ * with the list from the server or a faked-up list if the server didn't
+ * provide one.
+ */
+int nfs_mount(struct nfs_mount_request *info)
+{
+	struct mountres	result = {
+		.fh		= info->fh,
+		.auth_count	= info->auth_flav_len,
+		.auth_flavors	= info->auth_flavs,
+	};
+	struct rpc_message msg	= {
+		.rpc_argp	= info->dirpath,
+		.rpc_resp	= &result,
+	};
+	struct rpc_create_args args = {
+		.net		= info->net,
+		.protocol	= info->protocol,
+		.address	= info->sap,
+		.addrsize	= info->salen,
+		.servername	= info->hostname,
+		.program	= &mnt_program,
+		.version	= info->version,
+		.authflavor	= RPC_AUTH_UNIX,
+		.cred		= current_cred(),
+	};
+	struct rpc_clnt		*mnt_clnt;
+	int			status;
+
+	dprintk("NFS: sending MNT request for %s:%s\n",
+		(info->hostname ? info->hostname : "server"),
+			info->dirpath);
+
+	if (strlen(info->dirpath) > MNTPATHLEN)
+		return -ENAMETOOLONG;
+
+	if (info->noresvport)
+		args.flags |= RPC_CLNT_CREATE_NONPRIVPORT;
+
+	mnt_clnt = rpc_create(&args);
+	if (IS_ERR(mnt_clnt))
+		goto out_clnt_err;
+
+	if (info->version == NFS_MNT3_VERSION)
+		msg.rpc_proc = &mnt_clnt->cl_procinfo[MOUNTPROC3_MNT];
+	else
+		msg.rpc_proc = &mnt_clnt->cl_procinfo[MOUNTPROC_MNT];
+
+	status = rpc_call_sync(mnt_clnt, &msg, RPC_TASK_SOFT|RPC_TASK_TIMEOUT);
+	rpc_shutdown_client(mnt_clnt);
+
+	if (status < 0)
+		goto out_call_err;
+	if (result.errno != 0)
+		goto out_mnt_err;
+
+	dprintk("NFS: MNT request succeeded\n");
+	status = 0;
+
+	/*
+	 * If the server didn't provide a flavor list, allow the
+	 * client to try any flavor.
+	 */
+	if (info->version != NFS_MNT3_VERSION || *info->auth_flav_len == 0) {
+		dprintk("NFS: Faking up auth_flavs list\n");
+		info->auth_flavs[0] = RPC_AUTH_NULL;
+		*info->auth_flav_len = 1;
+	}
+out:
+	return status;
+
+out_clnt_err:
+	status = PTR_ERR(mnt_clnt);
+	dprintk("NFS: failed to create MNT RPC client, status=%d\n", status);
+	goto out;
+
+out_call_err:
+	dprintk("NFS: MNT request failed, status=%d\n", status);
+	goto out;
+
+out_mnt_err:
+	dprintk("NFS: MNT server returned result %d\n", result.errno);
+	status = result.errno;
+	goto out;
+}
+
+/**
+ * nfs_umount - Notify a server that we have unmounted this export
+ * @info: pointer to umount request arguments
+ *
+ * MOUNTPROC_UMNT is advisory, so we set a short timeout, and always
+ * use UDP.
+ */
+void nfs_umount(const struct nfs_mount_request *info)
+{
+	static const struct rpc_timeout nfs_umnt_timeout = {
+		.to_initval = 1 * HZ,
+		.to_maxval = 3 * HZ,
+		.to_retries = 2,
+	};
+	struct rpc_create_args args = {
+		.net		= info->net,
+		.protocol	= IPPROTO_UDP,
+		.address	= info->sap,
+		.addrsize	= info->salen,
+		.timeout	= &nfs_umnt_timeout,
+		.servername	= info->hostname,
+		.program	= &mnt_program,
+		.version	= info->version,
+		.authflavor	= RPC_AUTH_UNIX,
+		.flags		= RPC_CLNT_CREATE_NOPING,
+		.cred		= current_cred(),
+	};
+	struct rpc_message msg	= {
+		.rpc_argp	= info->dirpath,
+	};
+	struct rpc_clnt *clnt;
+	int status;
+
+	if (strlen(info->dirpath) > MNTPATHLEN)
+		return;
+
+	if (info->noresvport)
+		args.flags |= RPC_CLNT_CREATE_NONPRIVPORT;
+
+	clnt = rpc_create(&args);
+	if (IS_ERR(clnt))
+		goto out_clnt_err;
+
+	dprintk("NFS: sending UMNT request for %s:%s\n",
+		(info->hostname ? info->hostname : "server"), info->dirpath);
+
+	if (info->version == NFS_MNT3_VERSION)
+		msg.rpc_proc = &clnt->cl_procinfo[MOUNTPROC3_UMNT];
+	else
+		msg.rpc_proc = &clnt->cl_procinfo[MOUNTPROC_UMNT];
+
+	status = rpc_call_sync(clnt, &msg, 0);
+	rpc_shutdown_client(clnt);
+
+	if (unlikely(status < 0))
+		goto out_call_err;
+
+	return;
+
+out_clnt_err:
+	dprintk("NFS: failed to create UMNT RPC client, status=%ld\n",
+			PTR_ERR(clnt));
+	return;
+
+out_call_err:
+	dprintk("NFS: UMNT request failed, status=%d\n", status);
+}
+
+/*
+ * XDR encode/decode functions for MOUNT
+ */
+
+static void encode_mntdirpath(struct xdr_stream *xdr, const char *pathname)
+{
+	const u32 pathname_len = strlen(pathname);
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 4 + pathname_len);
+	xdr_encode_opaque(p, pathname, pathname_len);
+}
+
+static void mnt_xdr_enc_dirpath(struct rpc_rqst *req, struct xdr_stream *xdr,
+				const void *dirpath)
+{
+	encode_mntdirpath(xdr, dirpath);
+}
+
+/*
+ * RFC 1094: "A non-zero status indicates some sort of error.  In this
+ * case, the status is a UNIX error number."  This can be problematic
+ * if the server and client use different errno values for the same
+ * error.
+ *
+ * However, the OpenGroup XNFS spec provides a simple mapping that is
+ * independent of local errno values on the server and the client.
+ */
+static int decode_status(struct xdr_stream *xdr, struct mountres *res)
+{
+	unsigned int i;
+	u32 status;
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(p == NULL))
+		return -EIO;
+	status = be32_to_cpup(p);
+
+	for (i = 0; i < ARRAY_SIZE(mnt_errtbl); i++) {
+		if (mnt_errtbl[i].status == status) {
+			res->errno = mnt_errtbl[i].errno;
+			return 0;
+		}
+	}
+
+	dprintk("NFS: unrecognized MNT status code: %u\n", status);
+	res->errno = -EACCES;
+	return 0;
+}
+
+static int decode_fhandle(struct xdr_stream *xdr, struct mountres *res)
+{
+	struct nfs_fh *fh = res->fh;
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, NFS2_FHSIZE);
+	if (unlikely(p == NULL))
+		return -EIO;
+
+	fh->size = NFS2_FHSIZE;
+	memcpy(fh->data, p, NFS2_FHSIZE);
+	return 0;
+}
+
+static int mnt_xdr_dec_mountres(struct rpc_rqst *req,
+				struct xdr_stream *xdr,
+				void *data)
+{
+	struct mountres *res = data;
+	int status;
+
+	status = decode_status(xdr, res);
+	if (unlikely(status != 0 || res->errno != 0))
+		return status;
+	return decode_fhandle(xdr, res);
+}
+
+static int decode_fhs_status(struct xdr_stream *xdr, struct mountres *res)
+{
+	unsigned int i;
+	u32 status;
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(p == NULL))
+		return -EIO;
+	status = be32_to_cpup(p);
+
+	for (i = 0; i < ARRAY_SIZE(mnt3_errtbl); i++) {
+		if (mnt3_errtbl[i].status == status) {
+			res->errno = mnt3_errtbl[i].errno;
+			return 0;
+		}
+	}
+
+	dprintk("NFS: unrecognized MNT3 status code: %u\n", status);
+	res->errno = -EACCES;
+	return 0;
+}
+
+static int decode_fhandle3(struct xdr_stream *xdr, struct mountres *res)
+{
+	struct nfs_fh *fh = res->fh;
+	u32 size;
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(p == NULL))
+		return -EIO;
+
+	size = be32_to_cpup(p);
+	if (size > NFS3_FHSIZE || size == 0)
+		return -EIO;
+
+	p = xdr_inline_decode(xdr, size);
+	if (unlikely(p == NULL))
+		return -EIO;
+
+	fh->size = size;
+	memcpy(fh->data, p, size);
+	return 0;
+}
+
+static int decode_auth_flavors(struct xdr_stream *xdr, struct mountres *res)
+{
+	rpc_authflavor_t *flavors = res->auth_flavors;
+	unsigned int *count = res->auth_count;
+	u32 entries, i;
+	__be32 *p;
+
+	if (*count == 0)
+		return 0;
+
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(p == NULL))
+		return -EIO;
+	entries = be32_to_cpup(p);
+	dprintk("NFS: received %u auth flavors\n", entries);
+	if (entries > NFS_MAX_SECFLAVORS)
+		entries = NFS_MAX_SECFLAVORS;
+
+	p = xdr_inline_decode(xdr, 4 * entries);
+	if (unlikely(p == NULL))
+		return -EIO;
+
+	if (entries > *count)
+		entries = *count;
+
+	for (i = 0; i < entries; i++) {
+		flavors[i] = be32_to_cpup(p++);
+		dprintk("NFS:   auth flavor[%u]: %d\n", i, flavors[i]);
+	}
+	*count = i;
+
+	return 0;
+}
+
+static int mnt_xdr_dec_mountres3(struct rpc_rqst *req,
+				 struct xdr_stream *xdr,
+				 void *data)
+{
+	struct mountres *res = data;
+	int status;
+
+	status = decode_fhs_status(xdr, res);
+	if (unlikely(status != 0 || res->errno != 0))
+		return status;
+	status = decode_fhandle3(xdr, res);
+	if (unlikely(status != 0)) {
+		res->errno = -EBADHANDLE;
+		return 0;
+	}
+	return decode_auth_flavors(xdr, res);
+}
+
+static const struct rpc_procinfo mnt_procedures[] = {
+	[MOUNTPROC_MNT] = {
+		.p_proc		= MOUNTPROC_MNT,
+		.p_encode	= mnt_xdr_enc_dirpath,
+		.p_decode	= mnt_xdr_dec_mountres,
+		.p_arglen	= MNT_enc_dirpath_sz,
+		.p_replen	= MNT_dec_mountres_sz,
+		.p_statidx	= MOUNTPROC_MNT,
+		.p_name		= "MOUNT",
+	},
+	[MOUNTPROC_UMNT] = {
+		.p_proc		= MOUNTPROC_UMNT,
+		.p_encode	= mnt_xdr_enc_dirpath,
+		.p_arglen	= MNT_enc_dirpath_sz,
+		.p_statidx	= MOUNTPROC_UMNT,
+		.p_name		= "UMOUNT",
+	},
+};
+
+static const struct rpc_procinfo mnt3_procedures[] = {
+	[MOUNTPROC3_MNT] = {
+		.p_proc		= MOUNTPROC3_MNT,
+		.p_encode	= mnt_xdr_enc_dirpath,
+		.p_decode	= mnt_xdr_dec_mountres3,
+		.p_arglen	= MNT_enc_dirpath_sz,
+		.p_replen	= MNT_dec_mountres3_sz,
+		.p_statidx	= MOUNTPROC3_MNT,
+		.p_name		= "MOUNT",
+	},
+	[MOUNTPROC3_UMNT] = {
+		.p_proc		= MOUNTPROC3_UMNT,
+		.p_encode	= mnt_xdr_enc_dirpath,
+		.p_arglen	= MNT_enc_dirpath_sz,
+		.p_statidx	= MOUNTPROC3_UMNT,
+		.p_name		= "UMOUNT",
+	},
+};
+
+static unsigned int mnt_counts[ARRAY_SIZE(mnt_procedures)];
+static const struct rpc_version mnt_version1 = {
+	.number		= 1,
+	.nrprocs	= ARRAY_SIZE(mnt_procedures),
+	.procs		= mnt_procedures,
+	.counts		= mnt_counts,
+};
+
+static unsigned int mnt3_counts[ARRAY_SIZE(mnt3_procedures)];
+static const struct rpc_version mnt_version3 = {
+	.number		= 3,
+	.nrprocs	= ARRAY_SIZE(mnt3_procedures),
+	.procs		= mnt3_procedures,
+	.counts		= mnt3_counts,
+};
+
+static const struct rpc_version *mnt_version[] = {
+	NULL,
+	&mnt_version1,
+	NULL,
+	&mnt_version3,
+};
+
+static struct rpc_stat mnt_stats;
+
+static const struct rpc_program mnt_program = {
+	.name		= "mount",
+	.number		= NFS_MNT_PROGRAM,
+	.nrvers		= ARRAY_SIZE(mnt_version),
+	.version	= mnt_version,
+	.stats		= &mnt_stats,
+};
diff --git a/fs/nfs/namespace.c b/fs/nfs/namespace.c
new file mode 100644
index 000000000..1f03445b5
--- /dev/null
+++ b/fs/nfs/namespace.c
@@ -0,0 +1,367 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * linux/fs/nfs/namespace.c
+ *
+ * Copyright (C) 2005 Trond Myklebust <Trond.Myklebust@netapp.com>
+ * - Modified by David Howells <dhowells@redhat.com>
+ *
+ * NFS namespace
+ */
+
+#include <linux/module.h>
+#include <linux/dcache.h>
+#include <linux/gfp.h>
+#include <linux/mount.h>
+#include <linux/namei.h>
+#include <linux/nfs_fs.h>
+#include <linux/string.h>
+#include <linux/sunrpc/clnt.h>
+#include <linux/vfs.h>
+#include <linux/sunrpc/gss_api.h>
+#include "internal.h"
+#include "nfs.h"
+
+#define NFSDBG_FACILITY		NFSDBG_VFS
+
+static void nfs_expire_automounts(struct work_struct *work);
+
+static LIST_HEAD(nfs_automount_list);
+static DECLARE_DELAYED_WORK(nfs_automount_task, nfs_expire_automounts);
+int nfs_mountpoint_expiry_timeout = 500 * HZ;
+
+/*
+ * nfs_path - reconstruct the path given an arbitrary dentry
+ * @base - used to return pointer to the end of devname part of path
+ * @dentry_in - pointer to dentry
+ * @buffer - result buffer
+ * @buflen_in - length of buffer
+ * @flags - options (see below)
+ *
+ * Helper function for constructing the server pathname
+ * by arbitrary hashed dentry.
+ *
+ * This is mainly for use in figuring out the path on the
+ * server side when automounting on top of an existing partition
+ * and in generating /proc/mounts and friends.
+ *
+ * Supported flags:
+ * NFS_PATH_CANONICAL: ensure there is exactly one slash after
+ *		       the original device (export) name
+ *		       (if unset, the original name is returned verbatim)
+ */
+char *nfs_path(char **p, struct dentry *dentry_in, char *buffer,
+	       ssize_t buflen_in, unsigned flags)
+{
+	char *end;
+	int namelen;
+	unsigned seq;
+	const char *base;
+	struct dentry *dentry;
+	ssize_t buflen;
+
+rename_retry:
+	buflen = buflen_in;
+	dentry = dentry_in;
+	end = buffer+buflen;
+	*--end = '\0';
+	buflen--;
+
+	seq = read_seqbegin(&rename_lock);
+	rcu_read_lock();
+	while (1) {
+		spin_lock(&dentry->d_lock);
+		if (IS_ROOT(dentry))
+			break;
+		namelen = dentry->d_name.len;
+		buflen -= namelen + 1;
+		if (buflen < 0)
+			goto Elong_unlock;
+		end -= namelen;
+		memcpy(end, dentry->d_name.name, namelen);
+		*--end = '/';
+		spin_unlock(&dentry->d_lock);
+		dentry = dentry->d_parent;
+	}
+	if (read_seqretry(&rename_lock, seq)) {
+		spin_unlock(&dentry->d_lock);
+		rcu_read_unlock();
+		goto rename_retry;
+	}
+	if ((flags & NFS_PATH_CANONICAL) && *end != '/') {
+		if (--buflen < 0) {
+			spin_unlock(&dentry->d_lock);
+			rcu_read_unlock();
+			goto Elong;
+		}
+		*--end = '/';
+	}
+	*p = end;
+	base = dentry->d_fsdata;
+	if (!base) {
+		spin_unlock(&dentry->d_lock);
+		rcu_read_unlock();
+		WARN_ON(1);
+		return end;
+	}
+	namelen = strlen(base);
+	if (*end == '/') {
+		/* Strip off excess slashes in base string */
+		while (namelen > 0 && base[namelen - 1] == '/')
+			namelen--;
+	}
+	buflen -= namelen;
+	if (buflen < 0) {
+		spin_unlock(&dentry->d_lock);
+		rcu_read_unlock();
+		goto Elong;
+	}
+	end -= namelen;
+	memcpy(end, base, namelen);
+	spin_unlock(&dentry->d_lock);
+	rcu_read_unlock();
+	return end;
+Elong_unlock:
+	spin_unlock(&dentry->d_lock);
+	rcu_read_unlock();
+	if (read_seqretry(&rename_lock, seq))
+		goto rename_retry;
+Elong:
+	return ERR_PTR(-ENAMETOOLONG);
+}
+EXPORT_SYMBOL_GPL(nfs_path);
+
+/*
+ * nfs_d_automount - Handle crossing a mountpoint on the server
+ * @path - The mountpoint
+ *
+ * When we encounter a mountpoint on the server, we want to set up
+ * a mountpoint on the client too, to prevent inode numbers from
+ * colliding, and to allow "df" to work properly.
+ * On NFSv4, we also want to allow for the fact that different
+ * filesystems may be migrated to different servers in a failover
+ * situation, and that different filesystems may want to use
+ * different security flavours.
+ */
+struct vfsmount *nfs_d_automount(struct path *path)
+{
+	struct nfs_fs_context *ctx;
+	struct fs_context *fc;
+	struct vfsmount *mnt = ERR_PTR(-ENOMEM);
+	struct nfs_server *server = NFS_SB(path->dentry->d_sb);
+	struct nfs_client *client = server->nfs_client;
+	int timeout = READ_ONCE(nfs_mountpoint_expiry_timeout);
+	int ret;
+
+	if (IS_ROOT(path->dentry))
+		return ERR_PTR(-ESTALE);
+
+	/* Open a new filesystem context, transferring parameters from the
+	 * parent superblock, including the network namespace.
+	 */
+	fc = fs_context_for_submount(path->mnt->mnt_sb->s_type, path->dentry);
+	if (IS_ERR(fc))
+		return ERR_CAST(fc);
+
+	ctx = nfs_fc2context(fc);
+	ctx->clone_data.dentry	= path->dentry;
+	ctx->clone_data.sb	= path->dentry->d_sb;
+	ctx->clone_data.fattr	= nfs_alloc_fattr();
+	if (!ctx->clone_data.fattr)
+		goto out_fc;
+
+	if (fc->net_ns != client->cl_net) {
+		put_net(fc->net_ns);
+		fc->net_ns = get_net(client->cl_net);
+	}
+
+	/* for submounts we want the same server; referrals will reassign */
+	memcpy(&ctx->nfs_server.address, &client->cl_addr, client->cl_addrlen);
+	ctx->nfs_server.addrlen	= client->cl_addrlen;
+	ctx->nfs_server.port	= server->port;
+
+	ctx->version		= client->rpc_ops->version;
+	ctx->minorversion	= client->cl_minorversion;
+	ctx->nfs_mod		= client->cl_nfs_mod;
+	__module_get(ctx->nfs_mod->owner);
+
+	ret = client->rpc_ops->submount(fc, server);
+	if (ret < 0) {
+		mnt = ERR_PTR(ret);
+		goto out_fc;
+	}
+
+	up_write(&fc->root->d_sb->s_umount);
+	mnt = vfs_create_mount(fc);
+	if (IS_ERR(mnt))
+		goto out_fc;
+
+	mntget(mnt); /* prevent immediate expiration */
+	if (timeout <= 0)
+		goto out_fc;
+
+	mnt_set_expiry(mnt, &nfs_automount_list);
+	schedule_delayed_work(&nfs_automount_task, timeout);
+
+out_fc:
+	put_fs_context(fc);
+	return mnt;
+}
+
+static int
+nfs_namespace_getattr(const struct path *path, struct kstat *stat,
+			u32 request_mask, unsigned int query_flags)
+{
+	if (NFS_FH(d_inode(path->dentry))->size != 0)
+		return nfs_getattr(path, stat, request_mask, query_flags);
+	generic_fillattr(d_inode(path->dentry), stat);
+	return 0;
+}
+
+static int
+nfs_namespace_setattr(struct dentry *dentry, struct iattr *attr)
+{
+	if (NFS_FH(d_inode(dentry))->size != 0)
+		return nfs_setattr(dentry, attr);
+	return -EACCES;
+}
+
+const struct inode_operations nfs_mountpoint_inode_operations = {
+	.getattr	= nfs_getattr,
+	.setattr	= nfs_setattr,
+};
+
+const struct inode_operations nfs_referral_inode_operations = {
+	.getattr	= nfs_namespace_getattr,
+	.setattr	= nfs_namespace_setattr,
+};
+
+static void nfs_expire_automounts(struct work_struct *work)
+{
+	struct list_head *list = &nfs_automount_list;
+	int timeout = READ_ONCE(nfs_mountpoint_expiry_timeout);
+
+	mark_mounts_for_expiry(list);
+	if (!list_empty(list) && timeout > 0)
+		schedule_delayed_work(&nfs_automount_task, timeout);
+}
+
+void nfs_release_automount_timer(void)
+{
+	if (list_empty(&nfs_automount_list))
+		cancel_delayed_work(&nfs_automount_task);
+}
+
+/**
+ * nfs_do_submount - set up mountpoint when crossing a filesystem boundary
+ * @fc: pointer to struct nfs_fs_context
+ *
+ */
+int nfs_do_submount(struct fs_context *fc)
+{
+	struct nfs_fs_context *ctx = nfs_fc2context(fc);
+	struct dentry *dentry = ctx->clone_data.dentry;
+	struct nfs_server *server;
+	char *buffer, *p;
+	int ret;
+
+	/* create a new volume representation */
+	server = ctx->nfs_mod->rpc_ops->clone_server(NFS_SB(ctx->clone_data.sb),
+						     ctx->mntfh,
+						     ctx->clone_data.fattr,
+						     ctx->selected_flavor);
+
+	if (IS_ERR(server))
+		return PTR_ERR(server);
+
+	ctx->server = server;
+
+	buffer = kmalloc(4096, GFP_USER);
+	if (!buffer)
+		return -ENOMEM;
+
+	ctx->internal		= true;
+	ctx->clone_data.inherited_bsize = ctx->clone_data.sb->s_blocksize_bits;
+
+	p = nfs_devname(dentry, buffer, 4096);
+	if (IS_ERR(p)) {
+		nfs_errorf(fc, "NFS: Couldn't determine submount pathname");
+		ret = PTR_ERR(p);
+	} else {
+		ret = vfs_parse_fs_string(fc, "source", p, buffer + 4096 - p);
+		if (!ret)
+			ret = vfs_get_tree(fc);
+	}
+	kfree(buffer);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(nfs_do_submount);
+
+int nfs_submount(struct fs_context *fc, struct nfs_server *server)
+{
+	struct nfs_fs_context *ctx = nfs_fc2context(fc);
+	struct dentry *dentry = ctx->clone_data.dentry;
+	struct dentry *parent = dget_parent(dentry);
+	int err;
+
+	/* Look it up again to get its attributes */
+	err = server->nfs_client->rpc_ops->lookup(d_inode(parent), dentry,
+						  ctx->mntfh, ctx->clone_data.fattr,
+						  NULL);
+	dput(parent);
+	if (err != 0)
+		return err;
+
+	ctx->selected_flavor = server->client->cl_auth->au_flavor;
+	return nfs_do_submount(fc);
+}
+EXPORT_SYMBOL_GPL(nfs_submount);
+
+static int param_set_nfs_timeout(const char *val, const struct kernel_param *kp)
+{
+	long num;
+	int ret;
+
+	if (!val)
+		return -EINVAL;
+	ret = kstrtol(val, 0, &num);
+	if (ret)
+		return -EINVAL;
+	if (num > 0) {
+		if (num >= INT_MAX / HZ)
+			num = INT_MAX;
+		else
+			num *= HZ;
+		*((int *)kp->arg) = num;
+		if (!list_empty(&nfs_automount_list))
+			mod_delayed_work(system_wq, &nfs_automount_task, num);
+	} else {
+		*((int *)kp->arg) = -1*HZ;
+		cancel_delayed_work(&nfs_automount_task);
+	}
+	return 0;
+}
+
+static int param_get_nfs_timeout(char *buffer, const struct kernel_param *kp)
+{
+	long num = *((int *)kp->arg);
+
+	if (num > 0) {
+		if (num >= INT_MAX - (HZ - 1))
+			num = INT_MAX / HZ;
+		else
+			num = (num + (HZ - 1)) / HZ;
+	} else
+		num = -1;
+	return scnprintf(buffer, PAGE_SIZE, "%li\n", num);
+}
+
+static const struct kernel_param_ops param_ops_nfs_timeout = {
+	.set = param_set_nfs_timeout,
+	.get = param_get_nfs_timeout,
+};
+#define param_check_nfs_timeout(name, p) __param_check(name, p, int);
+
+module_param(nfs_mountpoint_expiry_timeout, nfs_timeout, 0644);
+MODULE_PARM_DESC(nfs_mountpoint_expiry_timeout,
+		"Set the NFS automounted mountpoint timeout value (seconds)."
+		"Values <= 0 turn expiration off.");
diff --git a/fs/nfs/netns.h b/fs/nfs/netns.h
new file mode 100644
index 000000000..c8374f74d
--- /dev/null
+++ b/fs/nfs/netns.h
@@ -0,0 +1,44 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * NFS-private data for each "struct net".  Accessed with net_generic().
+ */
+
+#ifndef __NFS_NETNS_H__
+#define __NFS_NETNS_H__
+
+#include <linux/nfs4.h>
+#include <net/net_namespace.h>
+#include <net/netns/generic.h>
+
+struct bl_dev_msg {
+	int32_t status;
+	uint32_t major, minor;
+};
+
+struct nfs_netns_client;
+
+struct nfs_net {
+	struct cache_detail *nfs_dns_resolve;
+	struct rpc_pipe *bl_device_pipe;
+	struct bl_dev_msg bl_mount_reply;
+	wait_queue_head_t bl_wq;
+	struct mutex bl_mutex;
+	struct list_head nfs_client_list;
+	struct list_head nfs_volume_list;
+#if IS_ENABLED(CONFIG_NFS_V4)
+	struct idr cb_ident_idr; /* Protected by nfs_client_lock */
+	unsigned short nfs_callback_tcpport;
+	unsigned short nfs_callback_tcpport6;
+	int cb_users[NFS4_MAX_MINOR_VERSION + 1];
+#endif
+	struct nfs_netns_client *nfs_client;
+	spinlock_t nfs_client_lock;
+	ktime_t boot_time;
+#ifdef CONFIG_PROC_FS
+	struct proc_dir_entry *proc_nfsfs;
+#endif
+};
+
+extern unsigned int nfs_net_id;
+
+#endif
diff --git a/fs/nfs/nfs.h b/fs/nfs/nfs.h
new file mode 100644
index 000000000..5ba00610a
--- /dev/null
+++ b/fs/nfs/nfs.h
@@ -0,0 +1,30 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2012 Netapp, Inc. All rights reserved.
+ *
+ * Function and structures exported by the NFS module
+ * for use by NFS version-specific modules.
+ */
+#ifndef __LINUX_INTERNAL_NFS_H
+#define __LINUX_INTERNAL_NFS_H
+
+#include <linux/fs.h>
+#include <linux/sunrpc/sched.h>
+#include <linux/nfs_xdr.h>
+
+struct nfs_subversion {
+	struct module *owner;	/* THIS_MODULE pointer */
+	struct file_system_type *nfs_fs;	/* NFS filesystem type */
+	const struct rpc_version *rpc_vers;	/* NFS version information */
+	const struct nfs_rpc_ops *rpc_ops;	/* NFS operations */
+	const struct super_operations *sops;	/* NFS Super operations */
+	const struct xattr_handler **xattr;	/* NFS xattr handlers */
+	struct list_head list;		/* List of NFS versions */
+};
+
+struct nfs_subversion *get_nfs_version(unsigned int);
+void put_nfs_version(struct nfs_subversion *);
+void register_nfs_version(struct nfs_subversion *);
+void unregister_nfs_version(struct nfs_subversion *);
+
+#endif /* __LINUX_INTERNAL_NFS_H */
diff --git a/fs/nfs/nfs2super.c b/fs/nfs/nfs2super.c
new file mode 100644
index 000000000..467f21ee6
--- /dev/null
+++ b/fs/nfs/nfs2super.c
@@ -0,0 +1,32 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2012 Netapp, Inc. All rights reserved.
+ */
+#include <linux/module.h>
+#include <linux/nfs_fs.h>
+#include "internal.h"
+#include "nfs.h"
+
+static struct nfs_subversion nfs_v2 = {
+	.owner = THIS_MODULE,
+	.nfs_fs   = &nfs_fs_type,
+	.rpc_vers = &nfs_version2,
+	.rpc_ops  = &nfs_v2_clientops,
+	.sops     = &nfs_sops,
+};
+
+static int __init init_nfs_v2(void)
+{
+	register_nfs_version(&nfs_v2);
+	return 0;
+}
+
+static void __exit exit_nfs_v2(void)
+{
+	unregister_nfs_version(&nfs_v2);
+}
+
+MODULE_LICENSE("GPL");
+
+module_init(init_nfs_v2);
+module_exit(exit_nfs_v2);
diff --git a/fs/nfs/nfs2xdr.c b/fs/nfs/nfs2xdr.c
new file mode 100644
index 000000000..b34196da1
--- /dev/null
+++ b/fs/nfs/nfs2xdr.c
@@ -0,0 +1,1156 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/nfs/nfs2xdr.c
+ *
+ * XDR functions to encode/decode NFS RPC arguments and results.
+ *
+ * Copyright (C) 1992, 1993, 1994  Rick Sladkey
+ * Copyright (C) 1996 Olaf Kirch
+ * 04 Aug 1998  Ion Badulescu <ionut@cs.columbia.edu>
+ * 		FIFO's need special handling in NFSv2
+ */
+
+#include <linux/param.h>
+#include <linux/time.h>
+#include <linux/mm.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/in.h>
+#include <linux/pagemap.h>
+#include <linux/proc_fs.h>
+#include <linux/sunrpc/clnt.h>
+#include <linux/nfs.h>
+#include <linux/nfs2.h>
+#include <linux/nfs_fs.h>
+#include "nfstrace.h"
+#include "internal.h"
+
+#define NFSDBG_FACILITY		NFSDBG_XDR
+
+/* Mapping from NFS error code to "errno" error code. */
+#define errno_NFSERR_IO		EIO
+
+/*
+ * Declare the space requirements for NFS arguments and replies as
+ * number of 32bit-words
+ */
+#define NFS_fhandle_sz		(8)
+#define NFS_sattr_sz		(8)
+#define NFS_filename_sz		(1+(NFS2_MAXNAMLEN>>2))
+#define NFS_path_sz		(1+(NFS2_MAXPATHLEN>>2))
+#define NFS_fattr_sz		(17)
+#define NFS_info_sz		(5)
+#define NFS_entry_sz		(NFS_filename_sz+3)
+
+#define NFS_diropargs_sz	(NFS_fhandle_sz+NFS_filename_sz)
+#define NFS_removeargs_sz	(NFS_fhandle_sz+NFS_filename_sz)
+#define NFS_sattrargs_sz	(NFS_fhandle_sz+NFS_sattr_sz)
+#define NFS_readlinkargs_sz	(NFS_fhandle_sz)
+#define NFS_readargs_sz		(NFS_fhandle_sz+3)
+#define NFS_writeargs_sz	(NFS_fhandle_sz+4)
+#define NFS_createargs_sz	(NFS_diropargs_sz+NFS_sattr_sz)
+#define NFS_renameargs_sz	(NFS_diropargs_sz+NFS_diropargs_sz)
+#define NFS_linkargs_sz		(NFS_fhandle_sz+NFS_diropargs_sz)
+#define NFS_symlinkargs_sz	(NFS_diropargs_sz+1+NFS_sattr_sz)
+#define NFS_readdirargs_sz	(NFS_fhandle_sz+2)
+
+#define NFS_attrstat_sz		(1+NFS_fattr_sz)
+#define NFS_diropres_sz		(1+NFS_fhandle_sz+NFS_fattr_sz)
+#define NFS_readlinkres_sz	(2+1)
+#define NFS_readres_sz		(1+NFS_fattr_sz+1+1)
+#define NFS_writeres_sz         (NFS_attrstat_sz)
+#define NFS_stat_sz		(1)
+#define NFS_readdirres_sz	(1+1)
+#define NFS_statfsres_sz	(1+NFS_info_sz)
+
+static int nfs_stat_to_errno(enum nfs_stat);
+
+/*
+ * Encode/decode NFSv2 basic data types
+ *
+ * Basic NFSv2 data types are defined in section 2.3 of RFC 1094:
+ * "NFS: Network File System Protocol Specification".
+ *
+ * Not all basic data types have their own encoding and decoding
+ * functions.  For run-time efficiency, some data types are encoded
+ * or decoded inline.
+ */
+
+static struct user_namespace *rpc_userns(const struct rpc_clnt *clnt)
+{
+	if (clnt && clnt->cl_cred)
+		return clnt->cl_cred->user_ns;
+	return &init_user_ns;
+}
+
+static struct user_namespace *rpc_rqst_userns(const struct rpc_rqst *rqstp)
+{
+	if (rqstp->rq_task)
+		return rpc_userns(rqstp->rq_task->tk_client);
+	return &init_user_ns;
+}
+
+/*
+ *	typedef opaque	nfsdata<>;
+ */
+static int decode_nfsdata(struct xdr_stream *xdr, struct nfs_pgio_res *result)
+{
+	u32 recvd, count;
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(!p))
+		return -EIO;
+	count = be32_to_cpup(p);
+	recvd = xdr_read_pages(xdr, count);
+	if (unlikely(count > recvd))
+		goto out_cheating;
+out:
+	result->eof = 0;	/* NFSv2 does not pass EOF flag on the wire. */
+	result->count = count;
+	return count;
+out_cheating:
+	dprintk("NFS: server cheating in read result: "
+		"count %u > recvd %u\n", count, recvd);
+	count = recvd;
+	goto out;
+}
+
+/*
+ *	enum stat {
+ *		NFS_OK = 0,
+ *		NFSERR_PERM = 1,
+ *		NFSERR_NOENT = 2,
+ *		NFSERR_IO = 5,
+ *		NFSERR_NXIO = 6,
+ *		NFSERR_ACCES = 13,
+ *		NFSERR_EXIST = 17,
+ *		NFSERR_NODEV = 19,
+ *		NFSERR_NOTDIR = 20,
+ *		NFSERR_ISDIR = 21,
+ *		NFSERR_FBIG = 27,
+ *		NFSERR_NOSPC = 28,
+ *		NFSERR_ROFS = 30,
+ *		NFSERR_NAMETOOLONG = 63,
+ *		NFSERR_NOTEMPTY = 66,
+ *		NFSERR_DQUOT = 69,
+ *		NFSERR_STALE = 70,
+ *		NFSERR_WFLUSH = 99
+ *	};
+ */
+static int decode_stat(struct xdr_stream *xdr, enum nfs_stat *status)
+{
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(!p))
+		return -EIO;
+	if (unlikely(*p != cpu_to_be32(NFS_OK)))
+		goto out_status;
+	*status = 0;
+	return 0;
+out_status:
+	*status = be32_to_cpup(p);
+	trace_nfs_xdr_status(xdr, (int)*status);
+	return 0;
+}
+
+/*
+ * 2.3.2.  ftype
+ *
+ *	enum ftype {
+ *		NFNON = 0,
+ *		NFREG = 1,
+ *		NFDIR = 2,
+ *		NFBLK = 3,
+ *		NFCHR = 4,
+ *		NFLNK = 5
+ *	};
+ *
+ */
+static __be32 *xdr_decode_ftype(__be32 *p, u32 *type)
+{
+	*type = be32_to_cpup(p++);
+	if (unlikely(*type > NF2FIFO))
+		*type = NFBAD;
+	return p;
+}
+
+/*
+ * 2.3.3.  fhandle
+ *
+ *	typedef opaque fhandle[FHSIZE];
+ */
+static void encode_fhandle(struct xdr_stream *xdr, const struct nfs_fh *fh)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, NFS2_FHSIZE);
+	memcpy(p, fh->data, NFS2_FHSIZE);
+}
+
+static int decode_fhandle(struct xdr_stream *xdr, struct nfs_fh *fh)
+{
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, NFS2_FHSIZE);
+	if (unlikely(!p))
+		return -EIO;
+	fh->size = NFS2_FHSIZE;
+	memcpy(fh->data, p, NFS2_FHSIZE);
+	return 0;
+}
+
+/*
+ * 2.3.4.  timeval
+ *
+ *	struct timeval {
+ *		unsigned int seconds;
+ *		unsigned int useconds;
+ *	};
+ */
+static __be32 *xdr_encode_time(__be32 *p, const struct timespec64 *timep)
+{
+	*p++ = cpu_to_be32((u32)timep->tv_sec);
+	if (timep->tv_nsec != 0)
+		*p++ = cpu_to_be32(timep->tv_nsec / NSEC_PER_USEC);
+	else
+		*p++ = cpu_to_be32(0);
+	return p;
+}
+
+/*
+ * Passing the invalid value useconds=1000000 is a Sun convention for
+ * "set to current server time".  It's needed to make permissions checks
+ * for the "touch" program across v2 mounts to Solaris and Irix servers
+ * work correctly.  See description of sattr in section 6.1 of "NFS
+ * Illustrated" by Brent Callaghan, Addison-Wesley, ISBN 0-201-32750-5.
+ */
+static __be32 *xdr_encode_current_server_time(__be32 *p,
+					      const struct timespec64 *timep)
+{
+	*p++ = cpu_to_be32(timep->tv_sec);
+	*p++ = cpu_to_be32(1000000);
+	return p;
+}
+
+static __be32 *xdr_decode_time(__be32 *p, struct timespec64 *timep)
+{
+	timep->tv_sec = be32_to_cpup(p++);
+	timep->tv_nsec = be32_to_cpup(p++) * NSEC_PER_USEC;
+	return p;
+}
+
+/*
+ * 2.3.5.  fattr
+ *
+ *	struct fattr {
+ *		ftype		type;
+ *		unsigned int	mode;
+ *		unsigned int	nlink;
+ *		unsigned int	uid;
+ *		unsigned int	gid;
+ *		unsigned int	size;
+ *		unsigned int	blocksize;
+ *		unsigned int	rdev;
+ *		unsigned int	blocks;
+ *		unsigned int	fsid;
+ *		unsigned int	fileid;
+ *		timeval		atime;
+ *		timeval		mtime;
+ *		timeval		ctime;
+ *	};
+ *
+ */
+static int decode_fattr(struct xdr_stream *xdr, struct nfs_fattr *fattr,
+		struct user_namespace *userns)
+{
+	u32 rdev, type;
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, NFS_fattr_sz << 2);
+	if (unlikely(!p))
+		return -EIO;
+
+	fattr->valid |= NFS_ATTR_FATTR_V2;
+
+	p = xdr_decode_ftype(p, &type);
+
+	fattr->mode = be32_to_cpup(p++);
+	fattr->nlink = be32_to_cpup(p++);
+	fattr->uid = make_kuid(userns, be32_to_cpup(p++));
+	if (!uid_valid(fattr->uid))
+		goto out_uid;
+	fattr->gid = make_kgid(userns, be32_to_cpup(p++));
+	if (!gid_valid(fattr->gid))
+		goto out_gid;
+		
+	fattr->size = be32_to_cpup(p++);
+	fattr->du.nfs2.blocksize = be32_to_cpup(p++);
+
+	rdev = be32_to_cpup(p++);
+	fattr->rdev = new_decode_dev(rdev);
+	if (type == (u32)NFCHR && rdev == (u32)NFS2_FIFO_DEV) {
+		fattr->mode = (fattr->mode & ~S_IFMT) | S_IFIFO;
+		fattr->rdev = 0;
+	}
+
+	fattr->du.nfs2.blocks = be32_to_cpup(p++);
+	fattr->fsid.major = be32_to_cpup(p++);
+	fattr->fsid.minor = 0;
+	fattr->fileid = be32_to_cpup(p++);
+
+	p = xdr_decode_time(p, &fattr->atime);
+	p = xdr_decode_time(p, &fattr->mtime);
+	xdr_decode_time(p, &fattr->ctime);
+	fattr->change_attr = nfs_timespec_to_change_attr(&fattr->ctime);
+
+	return 0;
+out_uid:
+	dprintk("NFS: returned invalid uid\n");
+	return -EINVAL;
+out_gid:
+	dprintk("NFS: returned invalid gid\n");
+	return -EINVAL;
+}
+
+/*
+ * 2.3.6.  sattr
+ *
+ *	struct sattr {
+ *		unsigned int	mode;
+ *		unsigned int	uid;
+ *		unsigned int	gid;
+ *		unsigned int	size;
+ *		timeval		atime;
+ *		timeval		mtime;
+ *	};
+ */
+
+#define NFS2_SATTR_NOT_SET	(0xffffffff)
+
+static __be32 *xdr_time_not_set(__be32 *p)
+{
+	*p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
+	*p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
+	return p;
+}
+
+static void encode_sattr(struct xdr_stream *xdr, const struct iattr *attr,
+		struct user_namespace *userns)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, NFS_sattr_sz << 2);
+
+	if (attr->ia_valid & ATTR_MODE)
+		*p++ = cpu_to_be32(attr->ia_mode);
+	else
+		*p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
+	if (attr->ia_valid & ATTR_UID)
+		*p++ = cpu_to_be32(from_kuid_munged(userns, attr->ia_uid));
+	else
+		*p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
+	if (attr->ia_valid & ATTR_GID)
+		*p++ = cpu_to_be32(from_kgid_munged(userns, attr->ia_gid));
+	else
+		*p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
+	if (attr->ia_valid & ATTR_SIZE)
+		*p++ = cpu_to_be32((u32)attr->ia_size);
+	else
+		*p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
+
+	if (attr->ia_valid & ATTR_ATIME_SET)
+		p = xdr_encode_time(p, &attr->ia_atime);
+	else if (attr->ia_valid & ATTR_ATIME)
+		p = xdr_encode_current_server_time(p, &attr->ia_atime);
+	else
+		p = xdr_time_not_set(p);
+	if (attr->ia_valid & ATTR_MTIME_SET)
+		xdr_encode_time(p, &attr->ia_mtime);
+	else if (attr->ia_valid & ATTR_MTIME)
+		xdr_encode_current_server_time(p, &attr->ia_mtime);
+	else
+		xdr_time_not_set(p);
+}
+
+/*
+ * 2.3.7.  filename
+ *
+ *	typedef string filename<MAXNAMLEN>;
+ */
+static void encode_filename(struct xdr_stream *xdr,
+			    const char *name, u32 length)
+{
+	__be32 *p;
+
+	WARN_ON_ONCE(length > NFS2_MAXNAMLEN);
+	p = xdr_reserve_space(xdr, 4 + length);
+	xdr_encode_opaque(p, name, length);
+}
+
+static int decode_filename_inline(struct xdr_stream *xdr,
+				  const char **name, u32 *length)
+{
+	__be32 *p;
+	u32 count;
+
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(!p))
+		return -EIO;
+	count = be32_to_cpup(p);
+	if (count > NFS3_MAXNAMLEN)
+		goto out_nametoolong;
+	p = xdr_inline_decode(xdr, count);
+	if (unlikely(!p))
+		return -EIO;
+	*name = (const char *)p;
+	*length = count;
+	return 0;
+out_nametoolong:
+	dprintk("NFS: returned filename too long: %u\n", count);
+	return -ENAMETOOLONG;
+}
+
+/*
+ * 2.3.8.  path
+ *
+ *	typedef string path<MAXPATHLEN>;
+ */
+static void encode_path(struct xdr_stream *xdr, struct page **pages, u32 length)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 4);
+	*p = cpu_to_be32(length);
+	xdr_write_pages(xdr, pages, 0, length);
+}
+
+static int decode_path(struct xdr_stream *xdr)
+{
+	u32 length, recvd;
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(!p))
+		return -EIO;
+	length = be32_to_cpup(p);
+	if (unlikely(length >= xdr->buf->page_len || length > NFS_MAXPATHLEN))
+		goto out_size;
+	recvd = xdr_read_pages(xdr, length);
+	if (unlikely(length > recvd))
+		goto out_cheating;
+	xdr_terminate_string(xdr->buf, length);
+	return 0;
+out_size:
+	dprintk("NFS: returned pathname too long: %u\n", length);
+	return -ENAMETOOLONG;
+out_cheating:
+	dprintk("NFS: server cheating in pathname result: "
+		"length %u > received %u\n", length, recvd);
+	return -EIO;
+}
+
+/*
+ * 2.3.9.  attrstat
+ *
+ *	union attrstat switch (stat status) {
+ *	case NFS_OK:
+ *		fattr attributes;
+ *	default:
+ *		void;
+ *	};
+ */
+static int decode_attrstat(struct xdr_stream *xdr, struct nfs_fattr *result,
+			   __u32 *op_status,
+			   struct user_namespace *userns)
+{
+	enum nfs_stat status;
+	int error;
+
+	error = decode_stat(xdr, &status);
+	if (unlikely(error))
+		goto out;
+	if (op_status)
+		*op_status = status;
+	if (status != NFS_OK)
+		goto out_default;
+	error = decode_fattr(xdr, result, userns);
+out:
+	return error;
+out_default:
+	return nfs_stat_to_errno(status);
+}
+
+/*
+ * 2.3.10.  diropargs
+ *
+ *	struct diropargs {
+ *		fhandle  dir;
+ *		filename name;
+ *	};
+ */
+static void encode_diropargs(struct xdr_stream *xdr, const struct nfs_fh *fh,
+			     const char *name, u32 length)
+{
+	encode_fhandle(xdr, fh);
+	encode_filename(xdr, name, length);
+}
+
+/*
+ * 2.3.11.  diropres
+ *
+ *	union diropres switch (stat status) {
+ *	case NFS_OK:
+ *		struct {
+ *			fhandle file;
+ *			fattr   attributes;
+ *		} diropok;
+ *	default:
+ *		void;
+ *	};
+ */
+static int decode_diropok(struct xdr_stream *xdr, struct nfs_diropok *result,
+		struct user_namespace *userns)
+{
+	int error;
+
+	error = decode_fhandle(xdr, result->fh);
+	if (unlikely(error))
+		goto out;
+	error = decode_fattr(xdr, result->fattr, userns);
+out:
+	return error;
+}
+
+static int decode_diropres(struct xdr_stream *xdr, struct nfs_diropok *result,
+		struct user_namespace *userns)
+{
+	enum nfs_stat status;
+	int error;
+
+	error = decode_stat(xdr, &status);
+	if (unlikely(error))
+		goto out;
+	if (status != NFS_OK)
+		goto out_default;
+	error = decode_diropok(xdr, result, userns);
+out:
+	return error;
+out_default:
+	return nfs_stat_to_errno(status);
+}
+
+
+/*
+ * NFSv2 XDR encode functions
+ *
+ * NFSv2 argument types are defined in section 2.2 of RFC 1094:
+ * "NFS: Network File System Protocol Specification".
+ */
+
+static void nfs2_xdr_enc_fhandle(struct rpc_rqst *req,
+				 struct xdr_stream *xdr,
+				 const void *data)
+{
+	const struct nfs_fh *fh = data;
+
+	encode_fhandle(xdr, fh);
+}
+
+/*
+ * 2.2.3.  sattrargs
+ *
+ *	struct sattrargs {
+ *		fhandle file;
+ *		sattr attributes;
+ *	};
+ */
+static void nfs2_xdr_enc_sattrargs(struct rpc_rqst *req,
+				   struct xdr_stream *xdr,
+				   const void *data)
+{
+	const struct nfs_sattrargs *args = data;
+
+	encode_fhandle(xdr, args->fh);
+	encode_sattr(xdr, args->sattr, rpc_rqst_userns(req));
+}
+
+static void nfs2_xdr_enc_diropargs(struct rpc_rqst *req,
+				   struct xdr_stream *xdr,
+				   const void *data)
+{
+	const struct nfs_diropargs *args = data;
+
+	encode_diropargs(xdr, args->fh, args->name, args->len);
+}
+
+static void nfs2_xdr_enc_readlinkargs(struct rpc_rqst *req,
+				      struct xdr_stream *xdr,
+				      const void *data)
+{
+	const struct nfs_readlinkargs *args = data;
+
+	encode_fhandle(xdr, args->fh);
+	rpc_prepare_reply_pages(req, args->pages, args->pgbase,
+				args->pglen, NFS_readlinkres_sz);
+}
+
+/*
+ * 2.2.7.  readargs
+ *
+ *	struct readargs {
+ *		fhandle file;
+ *		unsigned offset;
+ *		unsigned count;
+ *		unsigned totalcount;
+ *	};
+ */
+static void encode_readargs(struct xdr_stream *xdr,
+			    const struct nfs_pgio_args *args)
+{
+	u32 offset = args->offset;
+	u32 count = args->count;
+	__be32 *p;
+
+	encode_fhandle(xdr, args->fh);
+
+	p = xdr_reserve_space(xdr, 4 + 4 + 4);
+	*p++ = cpu_to_be32(offset);
+	*p++ = cpu_to_be32(count);
+	*p = cpu_to_be32(count);
+}
+
+static void nfs2_xdr_enc_readargs(struct rpc_rqst *req,
+				  struct xdr_stream *xdr,
+				  const void *data)
+{
+	const struct nfs_pgio_args *args = data;
+
+	encode_readargs(xdr, args);
+	rpc_prepare_reply_pages(req, args->pages, args->pgbase,
+				args->count, NFS_readres_sz);
+	req->rq_rcv_buf.flags |= XDRBUF_READ;
+}
+
+/*
+ * 2.2.9.  writeargs
+ *
+ *	struct writeargs {
+ *		fhandle file;
+ *		unsigned beginoffset;
+ *		unsigned offset;
+ *		unsigned totalcount;
+ *		nfsdata data;
+ *	};
+ */
+static void encode_writeargs(struct xdr_stream *xdr,
+			     const struct nfs_pgio_args *args)
+{
+	u32 offset = args->offset;
+	u32 count = args->count;
+	__be32 *p;
+
+	encode_fhandle(xdr, args->fh);
+
+	p = xdr_reserve_space(xdr, 4 + 4 + 4 + 4);
+	*p++ = cpu_to_be32(offset);
+	*p++ = cpu_to_be32(offset);
+	*p++ = cpu_to_be32(count);
+
+	/* nfsdata */
+	*p = cpu_to_be32(count);
+	xdr_write_pages(xdr, args->pages, args->pgbase, count);
+}
+
+static void nfs2_xdr_enc_writeargs(struct rpc_rqst *req,
+				   struct xdr_stream *xdr,
+				   const void *data)
+{
+	const struct nfs_pgio_args *args = data;
+
+	encode_writeargs(xdr, args);
+	xdr->buf->flags |= XDRBUF_WRITE;
+}
+
+/*
+ * 2.2.10.  createargs
+ *
+ *	struct createargs {
+ *		diropargs where;
+ *		sattr attributes;
+ *	};
+ */
+static void nfs2_xdr_enc_createargs(struct rpc_rqst *req,
+				    struct xdr_stream *xdr,
+				    const void *data)
+{
+	const struct nfs_createargs *args = data;
+
+	encode_diropargs(xdr, args->fh, args->name, args->len);
+	encode_sattr(xdr, args->sattr, rpc_rqst_userns(req));
+}
+
+static void nfs2_xdr_enc_removeargs(struct rpc_rqst *req,
+				    struct xdr_stream *xdr,
+				    const void *data)
+{
+	const struct nfs_removeargs *args = data;
+
+	encode_diropargs(xdr, args->fh, args->name.name, args->name.len);
+}
+
+/*
+ * 2.2.12.  renameargs
+ *
+ *	struct renameargs {
+ *		diropargs from;
+ *		diropargs to;
+ *	};
+ */
+static void nfs2_xdr_enc_renameargs(struct rpc_rqst *req,
+				    struct xdr_stream *xdr,
+				    const void *data)
+{
+	const struct nfs_renameargs *args = data;
+	const struct qstr *old = args->old_name;
+	const struct qstr *new = args->new_name;
+
+	encode_diropargs(xdr, args->old_dir, old->name, old->len);
+	encode_diropargs(xdr, args->new_dir, new->name, new->len);
+}
+
+/*
+ * 2.2.13.  linkargs
+ *
+ *	struct linkargs {
+ *		fhandle from;
+ *		diropargs to;
+ *	};
+ */
+static void nfs2_xdr_enc_linkargs(struct rpc_rqst *req,
+				  struct xdr_stream *xdr,
+				  const void *data)
+{
+	const struct nfs_linkargs *args = data;
+
+	encode_fhandle(xdr, args->fromfh);
+	encode_diropargs(xdr, args->tofh, args->toname, args->tolen);
+}
+
+/*
+ * 2.2.14.  symlinkargs
+ *
+ *	struct symlinkargs {
+ *		diropargs from;
+ *		path to;
+ *		sattr attributes;
+ *	};
+ */
+static void nfs2_xdr_enc_symlinkargs(struct rpc_rqst *req,
+				     struct xdr_stream *xdr,
+				     const void *data)
+{
+	const struct nfs_symlinkargs *args = data;
+
+	encode_diropargs(xdr, args->fromfh, args->fromname, args->fromlen);
+	encode_path(xdr, args->pages, args->pathlen);
+	encode_sattr(xdr, args->sattr, rpc_rqst_userns(req));
+}
+
+/*
+ * 2.2.17.  readdirargs
+ *
+ *	struct readdirargs {
+ *		fhandle dir;
+ *		nfscookie cookie;
+ *		unsigned count;
+ *	};
+ */
+static void encode_readdirargs(struct xdr_stream *xdr,
+			       const struct nfs_readdirargs *args)
+{
+	__be32 *p;
+
+	encode_fhandle(xdr, args->fh);
+
+	p = xdr_reserve_space(xdr, 4 + 4);
+	*p++ = cpu_to_be32(args->cookie);
+	*p = cpu_to_be32(args->count);
+}
+
+static void nfs2_xdr_enc_readdirargs(struct rpc_rqst *req,
+				     struct xdr_stream *xdr,
+				     const void *data)
+{
+	const struct nfs_readdirargs *args = data;
+
+	encode_readdirargs(xdr, args);
+	rpc_prepare_reply_pages(req, args->pages, 0,
+				args->count, NFS_readdirres_sz);
+}
+
+/*
+ * NFSv2 XDR decode functions
+ *
+ * NFSv2 result types are defined in section 2.2 of RFC 1094:
+ * "NFS: Network File System Protocol Specification".
+ */
+
+static int nfs2_xdr_dec_stat(struct rpc_rqst *req, struct xdr_stream *xdr,
+			     void *__unused)
+{
+	enum nfs_stat status;
+	int error;
+
+	error = decode_stat(xdr, &status);
+	if (unlikely(error))
+		goto out;
+	if (status != NFS_OK)
+		goto out_default;
+out:
+	return error;
+out_default:
+	return nfs_stat_to_errno(status);
+}
+
+static int nfs2_xdr_dec_attrstat(struct rpc_rqst *req, struct xdr_stream *xdr,
+				 void *result)
+{
+	return decode_attrstat(xdr, result, NULL, rpc_rqst_userns(req));
+}
+
+static int nfs2_xdr_dec_diropres(struct rpc_rqst *req, struct xdr_stream *xdr,
+				 void *result)
+{
+	return decode_diropres(xdr, result, rpc_rqst_userns(req));
+}
+
+/*
+ * 2.2.6.  readlinkres
+ *
+ *	union readlinkres switch (stat status) {
+ *	case NFS_OK:
+ *		path data;
+ *	default:
+ *		void;
+ *	};
+ */
+static int nfs2_xdr_dec_readlinkres(struct rpc_rqst *req,
+				    struct xdr_stream *xdr, void *__unused)
+{
+	enum nfs_stat status;
+	int error;
+
+	error = decode_stat(xdr, &status);
+	if (unlikely(error))
+		goto out;
+	if (status != NFS_OK)
+		goto out_default;
+	error = decode_path(xdr);
+out:
+	return error;
+out_default:
+	return nfs_stat_to_errno(status);
+}
+
+/*
+ * 2.2.7.  readres
+ *
+ *	union readres switch (stat status) {
+ *	case NFS_OK:
+ *		fattr attributes;
+ *		nfsdata data;
+ *	default:
+ *		void;
+ *	};
+ */
+static int nfs2_xdr_dec_readres(struct rpc_rqst *req, struct xdr_stream *xdr,
+				void *data)
+{
+	struct nfs_pgio_res *result = data;
+	enum nfs_stat status;
+	int error;
+
+	error = decode_stat(xdr, &status);
+	if (unlikely(error))
+		goto out;
+	result->op_status = status;
+	if (status != NFS_OK)
+		goto out_default;
+	error = decode_fattr(xdr, result->fattr, rpc_rqst_userns(req));
+	if (unlikely(error))
+		goto out;
+	error = decode_nfsdata(xdr, result);
+out:
+	return error;
+out_default:
+	return nfs_stat_to_errno(status);
+}
+
+static int nfs2_xdr_dec_writeres(struct rpc_rqst *req, struct xdr_stream *xdr,
+				 void *data)
+{
+	struct nfs_pgio_res *result = data;
+
+	/* All NFSv2 writes are "file sync" writes */
+	result->verf->committed = NFS_FILE_SYNC;
+	return decode_attrstat(xdr, result->fattr, &result->op_status,
+			rpc_rqst_userns(req));
+}
+
+/**
+ * nfs2_decode_dirent - Decode a single NFSv2 directory entry stored in
+ *                      the local page cache.
+ * @xdr: XDR stream where entry resides
+ * @entry: buffer to fill in with entry data
+ * @plus: boolean indicating whether this should be a readdirplus entry
+ *
+ * Returns zero if successful, otherwise a negative errno value is
+ * returned.
+ *
+ * This function is not invoked during READDIR reply decoding, but
+ * rather whenever an application invokes the getdents(2) system call
+ * on a directory already in our cache.
+ *
+ * 2.2.17.  entry
+ *
+ *	struct entry {
+ *		unsigned	fileid;
+ *		filename	name;
+ *		nfscookie	cookie;
+ *		entry		*nextentry;
+ *	};
+ */
+int nfs2_decode_dirent(struct xdr_stream *xdr, struct nfs_entry *entry,
+		       bool plus)
+{
+	__be32 *p;
+	int error;
+
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(!p))
+		return -EAGAIN;
+	if (*p++ == xdr_zero) {
+		p = xdr_inline_decode(xdr, 4);
+		if (unlikely(!p))
+			return -EAGAIN;
+		if (*p++ == xdr_zero)
+			return -EAGAIN;
+		entry->eof = 1;
+		return -EBADCOOKIE;
+	}
+
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(!p))
+		return -EAGAIN;
+	entry->ino = be32_to_cpup(p);
+
+	error = decode_filename_inline(xdr, &entry->name, &entry->len);
+	if (unlikely(error))
+		return error == -ENAMETOOLONG ? -ENAMETOOLONG : -EAGAIN;
+
+	/*
+	 * The type (size and byte order) of nfscookie isn't defined in
+	 * RFC 1094.  This implementation assumes that it's an XDR uint32.
+	 */
+	entry->prev_cookie = entry->cookie;
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(!p))
+		return -EAGAIN;
+	entry->cookie = be32_to_cpup(p);
+
+	entry->d_type = DT_UNKNOWN;
+
+	return 0;
+}
+
+/*
+ * 2.2.17.  readdirres
+ *
+ *	union readdirres switch (stat status) {
+ *	case NFS_OK:
+ *		struct {
+ *			entry *entries;
+ *			bool eof;
+ *		} readdirok;
+ *	default:
+ *		void;
+ *	};
+ *
+ * Read the directory contents into the page cache, but don't
+ * touch them.  The actual decoding is done by nfs2_decode_dirent()
+ * during subsequent nfs_readdir() calls.
+ */
+static int decode_readdirok(struct xdr_stream *xdr)
+{
+	return xdr_read_pages(xdr, xdr->buf->page_len);
+}
+
+static int nfs2_xdr_dec_readdirres(struct rpc_rqst *req,
+				   struct xdr_stream *xdr, void *__unused)
+{
+	enum nfs_stat status;
+	int error;
+
+	error = decode_stat(xdr, &status);
+	if (unlikely(error))
+		goto out;
+	if (status != NFS_OK)
+		goto out_default;
+	error = decode_readdirok(xdr);
+out:
+	return error;
+out_default:
+	return nfs_stat_to_errno(status);
+}
+
+/*
+ * 2.2.18.  statfsres
+ *
+ *	union statfsres (stat status) {
+ *	case NFS_OK:
+ *		struct {
+ *			unsigned tsize;
+ *			unsigned bsize;
+ *			unsigned blocks;
+ *			unsigned bfree;
+ *			unsigned bavail;
+ *		} info;
+ *	default:
+ *		void;
+ *	};
+ */
+static int decode_info(struct xdr_stream *xdr, struct nfs2_fsstat *result)
+{
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, NFS_info_sz << 2);
+	if (unlikely(!p))
+		return -EIO;
+	result->tsize  = be32_to_cpup(p++);
+	result->bsize  = be32_to_cpup(p++);
+	result->blocks = be32_to_cpup(p++);
+	result->bfree  = be32_to_cpup(p++);
+	result->bavail = be32_to_cpup(p);
+	return 0;
+}
+
+static int nfs2_xdr_dec_statfsres(struct rpc_rqst *req, struct xdr_stream *xdr,
+				  void *result)
+{
+	enum nfs_stat status;
+	int error;
+
+	error = decode_stat(xdr, &status);
+	if (unlikely(error))
+		goto out;
+	if (status != NFS_OK)
+		goto out_default;
+	error = decode_info(xdr, result);
+out:
+	return error;
+out_default:
+	return nfs_stat_to_errno(status);
+}
+
+
+/*
+ * We need to translate between nfs status return values and
+ * the local errno values which may not be the same.
+ */
+static const struct {
+	int stat;
+	int errno;
+} nfs_errtbl[] = {
+	{ NFS_OK,		0		},
+	{ NFSERR_PERM,		-EPERM		},
+	{ NFSERR_NOENT,		-ENOENT		},
+	{ NFSERR_IO,		-errno_NFSERR_IO},
+	{ NFSERR_NXIO,		-ENXIO		},
+/*	{ NFSERR_EAGAIN,	-EAGAIN		}, */
+	{ NFSERR_ACCES,		-EACCES		},
+	{ NFSERR_EXIST,		-EEXIST		},
+	{ NFSERR_XDEV,		-EXDEV		},
+	{ NFSERR_NODEV,		-ENODEV		},
+	{ NFSERR_NOTDIR,	-ENOTDIR	},
+	{ NFSERR_ISDIR,		-EISDIR		},
+	{ NFSERR_INVAL,		-EINVAL		},
+	{ NFSERR_FBIG,		-EFBIG		},
+	{ NFSERR_NOSPC,		-ENOSPC		},
+	{ NFSERR_ROFS,		-EROFS		},
+	{ NFSERR_MLINK,		-EMLINK		},
+	{ NFSERR_NAMETOOLONG,	-ENAMETOOLONG	},
+	{ NFSERR_NOTEMPTY,	-ENOTEMPTY	},
+	{ NFSERR_DQUOT,		-EDQUOT		},
+	{ NFSERR_STALE,		-ESTALE		},
+	{ NFSERR_REMOTE,	-EREMOTE	},
+#ifdef EWFLUSH
+	{ NFSERR_WFLUSH,	-EWFLUSH	},
+#endif
+	{ NFSERR_BADHANDLE,	-EBADHANDLE	},
+	{ NFSERR_NOT_SYNC,	-ENOTSYNC	},
+	{ NFSERR_BAD_COOKIE,	-EBADCOOKIE	},
+	{ NFSERR_NOTSUPP,	-ENOTSUPP	},
+	{ NFSERR_TOOSMALL,	-ETOOSMALL	},
+	{ NFSERR_SERVERFAULT,	-EREMOTEIO	},
+	{ NFSERR_BADTYPE,	-EBADTYPE	},
+	{ NFSERR_JUKEBOX,	-EJUKEBOX	},
+	{ -1,			-EIO		}
+};
+
+/**
+ * nfs_stat_to_errno - convert an NFS status code to a local errno
+ * @status: NFS status code to convert
+ *
+ * Returns a local errno value, or -EIO if the NFS status code is
+ * not recognized.  This function is used jointly by NFSv2 and NFSv3.
+ */
+static int nfs_stat_to_errno(enum nfs_stat status)
+{
+	int i;
+
+	for (i = 0; nfs_errtbl[i].stat != -1; i++) {
+		if (nfs_errtbl[i].stat == (int)status)
+			return nfs_errtbl[i].errno;
+	}
+	dprintk("NFS: Unrecognized nfs status value: %u\n", status);
+	return nfs_errtbl[i].errno;
+}
+
+#define PROC(proc, argtype, restype, timer)				\
+[NFSPROC_##proc] = {							\
+	.p_proc	    =  NFSPROC_##proc,					\
+	.p_encode   =  nfs2_xdr_enc_##argtype,				\
+	.p_decode   =  nfs2_xdr_dec_##restype,				\
+	.p_arglen   =  NFS_##argtype##_sz,				\
+	.p_replen   =  NFS_##restype##_sz,				\
+	.p_timer    =  timer,						\
+	.p_statidx  =  NFSPROC_##proc,					\
+	.p_name     =  #proc,						\
+	}
+const struct rpc_procinfo nfs_procedures[] = {
+	PROC(GETATTR,	fhandle,	attrstat,	1),
+	PROC(SETATTR,	sattrargs,	attrstat,	0),
+	PROC(LOOKUP,	diropargs,	diropres,	2),
+	PROC(READLINK,	readlinkargs,	readlinkres,	3),
+	PROC(READ,	readargs,	readres,	3),
+	PROC(WRITE,	writeargs,	writeres,	4),
+	PROC(CREATE,	createargs,	diropres,	0),
+	PROC(REMOVE,	removeargs,	stat,		0),
+	PROC(RENAME,	renameargs,	stat,		0),
+	PROC(LINK,	linkargs,	stat,		0),
+	PROC(SYMLINK,	symlinkargs,	stat,		0),
+	PROC(MKDIR,	createargs,	diropres,	0),
+	PROC(RMDIR,	diropargs,	stat,		0),
+	PROC(READDIR,	readdirargs,	readdirres,	3),
+	PROC(STATFS,	fhandle,	statfsres,	0),
+};
+
+static unsigned int nfs_version2_counts[ARRAY_SIZE(nfs_procedures)];
+const struct rpc_version nfs_version2 = {
+	.number			= 2,
+	.nrprocs		= ARRAY_SIZE(nfs_procedures),
+	.procs			= nfs_procedures,
+	.counts			= nfs_version2_counts,
+};
diff --git a/fs/nfs/nfs3_fs.h b/fs/nfs/nfs3_fs.h
new file mode 100644
index 000000000..1b950b66b
--- /dev/null
+++ b/fs/nfs/nfs3_fs.h
@@ -0,0 +1,37 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2014 Anna Schumaker.
+ *
+ * NFSv3-specific filesystem definitions and declarations
+ */
+#ifndef __LINUX_FS_NFS_NFS3_FS_H
+#define __LINUX_FS_NFS_NFS3_FS_H
+
+/*
+ * nfs3acl.c
+ */
+#ifdef CONFIG_NFS_V3_ACL
+extern struct posix_acl *nfs3_get_acl(struct inode *inode, int type);
+extern int nfs3_set_acl(struct inode *inode, struct posix_acl *acl, int type);
+extern int nfs3_proc_setacls(struct inode *inode, struct posix_acl *acl,
+		struct posix_acl *dfacl);
+extern ssize_t nfs3_listxattr(struct dentry *, char *, size_t);
+extern const struct xattr_handler *nfs3_xattr_handlers[];
+#else
+static inline int nfs3_proc_setacls(struct inode *inode, struct posix_acl *acl,
+		struct posix_acl *dfacl)
+{
+	return 0;
+}
+#define nfs3_listxattr NULL
+#endif /* CONFIG_NFS_V3_ACL */
+
+/* nfs3client.c */
+struct nfs_server *nfs3_create_server(struct fs_context *);
+struct nfs_server *nfs3_clone_server(struct nfs_server *, struct nfs_fh *,
+				     struct nfs_fattr *, rpc_authflavor_t);
+
+/* nfs3super.c */
+extern struct nfs_subversion nfs_v3;
+
+#endif /* __LINUX_FS_NFS_NFS3_FS_H */
diff --git a/fs/nfs/nfs3acl.c b/fs/nfs/nfs3acl.c
new file mode 100644
index 000000000..c6c863382
--- /dev/null
+++ b/fs/nfs/nfs3acl.c
@@ -0,0 +1,344 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/fs.h>
+#include <linux/gfp.h>
+#include <linux/nfs.h>
+#include <linux/nfs3.h>
+#include <linux/nfs_fs.h>
+#include <linux/posix_acl_xattr.h>
+#include <linux/nfsacl.h>
+
+#include "internal.h"
+#include "nfs3_fs.h"
+
+#define NFSDBG_FACILITY	NFSDBG_PROC
+
+/*
+ * nfs3_prepare_get_acl, nfs3_complete_get_acl, nfs3_abort_get_acl: Helpers for
+ * caching get_acl results in a race-free way.  See fs/posix_acl.c:get_acl()
+ * for explanations.
+ */
+static void nfs3_prepare_get_acl(struct posix_acl **p)
+{
+	struct posix_acl *sentinel = uncached_acl_sentinel(current);
+
+	if (cmpxchg(p, ACL_NOT_CACHED, sentinel) != ACL_NOT_CACHED) {
+		/* Not the first reader or sentinel already in place. */
+	}
+}
+
+static void nfs3_complete_get_acl(struct posix_acl **p, struct posix_acl *acl)
+{
+	struct posix_acl *sentinel = uncached_acl_sentinel(current);
+
+	/* Only cache the ACL if our sentinel is still in place. */
+	posix_acl_dup(acl);
+	if (cmpxchg(p, sentinel, acl) != sentinel)
+		posix_acl_release(acl);
+}
+
+static void nfs3_abort_get_acl(struct posix_acl **p)
+{
+	struct posix_acl *sentinel = uncached_acl_sentinel(current);
+
+	/* Remove our sentinel upon failure. */
+	cmpxchg(p, sentinel, ACL_NOT_CACHED);
+}
+
+struct posix_acl *nfs3_get_acl(struct inode *inode, int type)
+{
+	struct nfs_server *server = NFS_SERVER(inode);
+	struct page *pages[NFSACL_MAXPAGES] = { };
+	struct nfs3_getaclargs args = {
+		.fh = NFS_FH(inode),
+		/* The xdr layer may allocate pages here. */
+		.pages = pages,
+	};
+	struct nfs3_getaclres res = {
+		NULL,
+	};
+	struct rpc_message msg = {
+		.rpc_argp	= &args,
+		.rpc_resp	= &res,
+	};
+	int status, count;
+
+	if (!nfs_server_capable(inode, NFS_CAP_ACLS))
+		return ERR_PTR(-EOPNOTSUPP);
+
+	status = nfs_revalidate_inode(server, inode);
+	if (status < 0)
+		return ERR_PTR(status);
+
+	/*
+	 * Only get the access acl when explicitly requested: We don't
+	 * need it for access decisions, and only some applications use
+	 * it. Applications which request the access acl first are not
+	 * penalized from this optimization.
+	 */
+	if (type == ACL_TYPE_ACCESS)
+		args.mask |= NFS_ACLCNT|NFS_ACL;
+	if (S_ISDIR(inode->i_mode))
+		args.mask |= NFS_DFACLCNT|NFS_DFACL;
+	if (args.mask == 0)
+		return NULL;
+
+	dprintk("NFS call getacl\n");
+	msg.rpc_proc = &server->client_acl->cl_procinfo[ACLPROC3_GETACL];
+	res.fattr = nfs_alloc_fattr();
+	if (res.fattr == NULL)
+		return ERR_PTR(-ENOMEM);
+
+	if (args.mask & NFS_ACL)
+		nfs3_prepare_get_acl(&inode->i_acl);
+	if (args.mask & NFS_DFACL)
+		nfs3_prepare_get_acl(&inode->i_default_acl);
+
+	status = rpc_call_sync(server->client_acl, &msg, 0);
+	dprintk("NFS reply getacl: %d\n", status);
+
+	/* pages may have been allocated at the xdr layer. */
+	for (count = 0; count < NFSACL_MAXPAGES && args.pages[count]; count++)
+		__free_page(args.pages[count]);
+
+	switch (status) {
+		case 0:
+			status = nfs_refresh_inode(inode, res.fattr);
+			break;
+		case -EPFNOSUPPORT:
+		case -EPROTONOSUPPORT:
+			dprintk("NFS_V3_ACL extension not supported; disabling\n");
+			server->caps &= ~NFS_CAP_ACLS;
+			fallthrough;
+		case -ENOTSUPP:
+			status = -EOPNOTSUPP;
+		default:
+			goto getout;
+	}
+	if ((args.mask & res.mask) != args.mask) {
+		status = -EIO;
+		goto getout;
+	}
+
+	if (res.acl_access != NULL) {
+		if ((posix_acl_equiv_mode(res.acl_access, NULL) == 0) ||
+		    res.acl_access->a_count == 0) {
+			posix_acl_release(res.acl_access);
+			res.acl_access = NULL;
+		}
+	}
+
+	if (res.mask & NFS_ACL)
+		nfs3_complete_get_acl(&inode->i_acl, res.acl_access);
+	else
+		forget_cached_acl(inode, ACL_TYPE_ACCESS);
+
+	if (res.mask & NFS_DFACL)
+		nfs3_complete_get_acl(&inode->i_default_acl, res.acl_default);
+	else
+		forget_cached_acl(inode, ACL_TYPE_DEFAULT);
+
+	nfs_free_fattr(res.fattr);
+	if (type == ACL_TYPE_ACCESS) {
+		posix_acl_release(res.acl_default);
+		return res.acl_access;
+	} else {
+		posix_acl_release(res.acl_access);
+		return res.acl_default;
+	}
+
+getout:
+	nfs3_abort_get_acl(&inode->i_acl);
+	nfs3_abort_get_acl(&inode->i_default_acl);
+	posix_acl_release(res.acl_access);
+	posix_acl_release(res.acl_default);
+	nfs_free_fattr(res.fattr);
+	return ERR_PTR(status);
+}
+
+static int __nfs3_proc_setacls(struct inode *inode, struct posix_acl *acl,
+		struct posix_acl *dfacl)
+{
+	struct nfs_server *server = NFS_SERVER(inode);
+	struct nfs_fattr *fattr;
+	struct page *pages[NFSACL_MAXPAGES];
+	struct nfs3_setaclargs args = {
+		.inode = inode,
+		.mask = NFS_ACL,
+		.acl_access = acl,
+		.pages = pages,
+	};
+	struct rpc_message msg = {
+		.rpc_argp	= &args,
+		.rpc_resp	= &fattr,
+	};
+	int status = 0;
+
+	if (acl == NULL && (!S_ISDIR(inode->i_mode) || dfacl == NULL))
+		goto out;
+
+	status = -EOPNOTSUPP;
+	if (!nfs_server_capable(inode, NFS_CAP_ACLS))
+		goto out;
+
+	/* We are doing this here because XDR marshalling does not
+	 * return any results, it BUGs. */
+	status = -ENOSPC;
+	if (acl != NULL && acl->a_count > NFS_ACL_MAX_ENTRIES)
+		goto out;
+	if (dfacl != NULL && dfacl->a_count > NFS_ACL_MAX_ENTRIES)
+		goto out;
+	if (S_ISDIR(inode->i_mode)) {
+		args.mask |= NFS_DFACL;
+		args.acl_default = dfacl;
+		args.len = nfsacl_size(acl, dfacl);
+	} else
+		args.len = nfsacl_size(acl, NULL);
+
+	if (args.len > NFS_ACL_INLINE_BUFSIZE) {
+		unsigned int npages = 1 + ((args.len - 1) >> PAGE_SHIFT);
+
+		status = -ENOMEM;
+		do {
+			args.pages[args.npages] = alloc_page(GFP_KERNEL);
+			if (args.pages[args.npages] == NULL)
+				goto out_freepages;
+			args.npages++;
+		} while (args.npages < npages);
+	}
+
+	dprintk("NFS call setacl\n");
+	status = -ENOMEM;
+	fattr = nfs_alloc_fattr();
+	if (fattr == NULL)
+		goto out_freepages;
+
+	msg.rpc_proc = &server->client_acl->cl_procinfo[ACLPROC3_SETACL];
+	msg.rpc_resp = fattr;
+	status = rpc_call_sync(server->client_acl, &msg, 0);
+	nfs_access_zap_cache(inode);
+	nfs_zap_acl_cache(inode);
+	dprintk("NFS reply setacl: %d\n", status);
+
+	switch (status) {
+		case 0:
+			status = nfs_refresh_inode(inode, fattr);
+			break;
+		case -EPFNOSUPPORT:
+		case -EPROTONOSUPPORT:
+			dprintk("NFS_V3_ACL SETACL RPC not supported"
+					"(will not retry)\n");
+			server->caps &= ~NFS_CAP_ACLS;
+			fallthrough;
+		case -ENOTSUPP:
+			status = -EOPNOTSUPP;
+	}
+	nfs_free_fattr(fattr);
+out_freepages:
+	while (args.npages != 0) {
+		args.npages--;
+		__free_page(args.pages[args.npages]);
+	}
+out:
+	return status;
+}
+
+int nfs3_proc_setacls(struct inode *inode, struct posix_acl *acl,
+		struct posix_acl *dfacl)
+{
+	int ret;
+	ret = __nfs3_proc_setacls(inode, acl, dfacl);
+	return (ret == -EOPNOTSUPP) ? 0 : ret;
+
+}
+
+int nfs3_set_acl(struct inode *inode, struct posix_acl *acl, int type)
+{
+	struct posix_acl *orig = acl, *dfacl = NULL, *alloc;
+	int status;
+
+	if (S_ISDIR(inode->i_mode)) {
+		switch(type) {
+		case ACL_TYPE_ACCESS:
+			alloc = get_acl(inode, ACL_TYPE_DEFAULT);
+			if (IS_ERR(alloc))
+				goto fail;
+			dfacl = alloc;
+			break;
+
+		case ACL_TYPE_DEFAULT:
+			alloc = get_acl(inode, ACL_TYPE_ACCESS);
+			if (IS_ERR(alloc))
+				goto fail;
+			dfacl = acl;
+			acl = alloc;
+			break;
+		}
+	}
+
+	if (acl == NULL) {
+		alloc = posix_acl_from_mode(inode->i_mode, GFP_KERNEL);
+		if (IS_ERR(alloc))
+			goto fail;
+		acl = alloc;
+	}
+	status = __nfs3_proc_setacls(inode, acl, dfacl);
+out:
+	if (acl != orig)
+		posix_acl_release(acl);
+	if (dfacl != orig)
+		posix_acl_release(dfacl);
+	return status;
+
+fail:
+	status = PTR_ERR(alloc);
+	goto out;
+}
+
+const struct xattr_handler *nfs3_xattr_handlers[] = {
+	&posix_acl_access_xattr_handler,
+	&posix_acl_default_xattr_handler,
+	NULL,
+};
+
+static int
+nfs3_list_one_acl(struct inode *inode, int type, const char *name, void *data,
+		size_t size, ssize_t *result)
+{
+	struct posix_acl *acl;
+	char *p = data + *result;
+
+	acl = get_acl(inode, type);
+	if (IS_ERR_OR_NULL(acl))
+		return 0;
+
+	posix_acl_release(acl);
+
+	*result += strlen(name);
+	*result += 1;
+	if (!size)
+		return 0;
+	if (*result > size)
+		return -ERANGE;
+
+	strcpy(p, name);
+	return 0;
+}
+
+ssize_t
+nfs3_listxattr(struct dentry *dentry, char *data, size_t size)
+{
+	struct inode *inode = d_inode(dentry);
+	ssize_t result = 0;
+	int error;
+
+	error = nfs3_list_one_acl(inode, ACL_TYPE_ACCESS,
+			XATTR_NAME_POSIX_ACL_ACCESS, data, size, &result);
+	if (error)
+		return error;
+
+	error = nfs3_list_one_acl(inode, ACL_TYPE_DEFAULT,
+			XATTR_NAME_POSIX_ACL_DEFAULT, data, size, &result);
+	if (error)
+		return error;
+	return result;
+}
diff --git a/fs/nfs/nfs3client.c b/fs/nfs/nfs3client.c
new file mode 100644
index 000000000..b49359afa
--- /dev/null
+++ b/fs/nfs/nfs3client.c
@@ -0,0 +1,119 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <linux/nfs_fs.h>
+#include <linux/nfs_mount.h>
+#include <linux/sunrpc/addr.h>
+#include "internal.h"
+#include "nfs3_fs.h"
+
+#ifdef CONFIG_NFS_V3_ACL
+static struct rpc_stat		nfsacl_rpcstat = { &nfsacl_program };
+static const struct rpc_version *nfsacl_version[] = {
+	[3]			= &nfsacl_version3,
+};
+
+const struct rpc_program nfsacl_program = {
+	.name			= "nfsacl",
+	.number			= NFS_ACL_PROGRAM,
+	.nrvers			= ARRAY_SIZE(nfsacl_version),
+	.version		= nfsacl_version,
+	.stats			= &nfsacl_rpcstat,
+};
+
+/*
+ * Initialise an NFSv3 ACL client connection
+ */
+static void nfs_init_server_aclclient(struct nfs_server *server)
+{
+	if (server->flags & NFS_MOUNT_NOACL)
+		goto out_noacl;
+
+	server->client_acl = rpc_bind_new_program(server->client, &nfsacl_program, 3);
+	if (IS_ERR(server->client_acl))
+		goto out_noacl;
+
+	/* No errors! Assume that Sun nfsacls are supported */
+	server->caps |= NFS_CAP_ACLS;
+	return;
+
+out_noacl:
+	server->caps &= ~NFS_CAP_ACLS;
+}
+#else
+static inline void nfs_init_server_aclclient(struct nfs_server *server)
+{
+	server->flags &= ~NFS_MOUNT_NOACL;
+	server->caps &= ~NFS_CAP_ACLS;
+}
+#endif
+
+struct nfs_server *nfs3_create_server(struct fs_context *fc)
+{
+	struct nfs_server *server = nfs_create_server(fc);
+
+	/* Create a client RPC handle for the NFS v3 ACL management interface */
+	if (!IS_ERR(server))
+		nfs_init_server_aclclient(server);
+	return server;
+}
+
+struct nfs_server *nfs3_clone_server(struct nfs_server *source,
+				     struct nfs_fh *fh,
+				     struct nfs_fattr *fattr,
+				     rpc_authflavor_t flavor)
+{
+	struct nfs_server *server = nfs_clone_server(source, fh, fattr, flavor);
+	if (!IS_ERR(server) && !IS_ERR(source->client_acl))
+		nfs_init_server_aclclient(server);
+	return server;
+}
+
+/*
+ * Set up a pNFS Data Server client over NFSv3.
+ *
+ * Return any existing nfs_client that matches server address,port,version
+ * and minorversion.
+ *
+ * For a new nfs_client, use a soft mount (default), a low retrans and a
+ * low timeout interval so that if a connection is lost, we retry through
+ * the MDS.
+ */
+struct nfs_client *nfs3_set_ds_client(struct nfs_server *mds_srv,
+		const struct sockaddr *ds_addr, int ds_addrlen,
+		int ds_proto, unsigned int ds_timeo, unsigned int ds_retrans)
+{
+	struct rpc_timeout ds_timeout;
+	struct nfs_client *mds_clp = mds_srv->nfs_client;
+	struct nfs_client_initdata cl_init = {
+		.addr = ds_addr,
+		.addrlen = ds_addrlen,
+		.nodename = mds_clp->cl_rpcclient->cl_nodename,
+		.ip_addr = mds_clp->cl_ipaddr,
+		.nfs_mod = &nfs_v3,
+		.proto = ds_proto,
+		.net = mds_clp->cl_net,
+		.timeparms = &ds_timeout,
+		.cred = mds_srv->cred,
+	};
+	struct nfs_client *clp;
+	char buf[INET6_ADDRSTRLEN + 1];
+
+	/* fake a hostname because lockd wants it */
+	if (rpc_ntop(ds_addr, buf, sizeof(buf)) <= 0)
+		return ERR_PTR(-EINVAL);
+	cl_init.hostname = buf;
+
+	if (mds_clp->cl_nconnect > 1 && ds_proto == XPRT_TRANSPORT_TCP)
+		cl_init.nconnect = mds_clp->cl_nconnect;
+
+	if (mds_srv->flags & NFS_MOUNT_NORESVPORT)
+		__set_bit(NFS_CS_NORESVPORT, &cl_init.init_flags);
+
+	__set_bit(NFS_CS_DS, &cl_init.init_flags);
+
+	/* Use the MDS nfs_client cl_ipaddr. */
+	nfs_init_timeout_values(&ds_timeout, ds_proto, ds_timeo, ds_retrans);
+	clp = nfs_get_client(&cl_init);
+
+	return clp;
+}
+EXPORT_SYMBOL_GPL(nfs3_set_ds_client);
diff --git a/fs/nfs/nfs3proc.c b/fs/nfs/nfs3proc.c
new file mode 100644
index 000000000..e1491def7
--- /dev/null
+++ b/fs/nfs/nfs3proc.c
@@ -0,0 +1,1044 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  linux/fs/nfs/nfs3proc.c
+ *
+ *  Client-side NFSv3 procedures stubs.
+ *
+ *  Copyright (C) 1997, Olaf Kirch
+ */
+
+#include <linux/mm.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/sunrpc/clnt.h>
+#include <linux/slab.h>
+#include <linux/nfs.h>
+#include <linux/nfs3.h>
+#include <linux/nfs_fs.h>
+#include <linux/nfs_page.h>
+#include <linux/lockd/bind.h>
+#include <linux/nfs_mount.h>
+#include <linux/freezer.h>
+#include <linux/xattr.h>
+
+#include "iostat.h"
+#include "internal.h"
+#include "nfs3_fs.h"
+
+#define NFSDBG_FACILITY		NFSDBG_PROC
+
+/* A wrapper to handle the EJUKEBOX error messages */
+static int
+nfs3_rpc_wrapper(struct rpc_clnt *clnt, struct rpc_message *msg, int flags)
+{
+	int res;
+	do {
+		res = rpc_call_sync(clnt, msg, flags);
+		if (res != -EJUKEBOX)
+			break;
+		freezable_schedule_timeout_killable_unsafe(NFS_JUKEBOX_RETRY_TIME);
+		res = -ERESTARTSYS;
+	} while (!fatal_signal_pending(current));
+	return res;
+}
+
+#define rpc_call_sync(clnt, msg, flags)	nfs3_rpc_wrapper(clnt, msg, flags)
+
+static int
+nfs3_async_handle_jukebox(struct rpc_task *task, struct inode *inode)
+{
+	if (task->tk_status != -EJUKEBOX)
+		return 0;
+	if (task->tk_status == -EJUKEBOX)
+		nfs_inc_stats(inode, NFSIOS_DELAY);
+	task->tk_status = 0;
+	rpc_restart_call(task);
+	rpc_delay(task, NFS_JUKEBOX_RETRY_TIME);
+	return 1;
+}
+
+static int
+do_proc_get_root(struct rpc_clnt *client, struct nfs_fh *fhandle,
+		 struct nfs_fsinfo *info)
+{
+	struct rpc_message msg = {
+		.rpc_proc	= &nfs3_procedures[NFS3PROC_FSINFO],
+		.rpc_argp	= fhandle,
+		.rpc_resp	= info,
+	};
+	int	status;
+
+	dprintk("%s: call  fsinfo\n", __func__);
+	nfs_fattr_init(info->fattr);
+	status = rpc_call_sync(client, &msg, 0);
+	dprintk("%s: reply fsinfo: %d\n", __func__, status);
+	if (status == 0 && !(info->fattr->valid & NFS_ATTR_FATTR)) {
+		msg.rpc_proc = &nfs3_procedures[NFS3PROC_GETATTR];
+		msg.rpc_resp = info->fattr;
+		status = rpc_call_sync(client, &msg, 0);
+		dprintk("%s: reply getattr: %d\n", __func__, status);
+	}
+	return status;
+}
+
+/*
+ * Bare-bones access to getattr: this is for nfs_get_root/nfs_get_sb
+ */
+static int
+nfs3_proc_get_root(struct nfs_server *server, struct nfs_fh *fhandle,
+		   struct nfs_fsinfo *info)
+{
+	int	status;
+
+	status = do_proc_get_root(server->client, fhandle, info);
+	if (status && server->nfs_client->cl_rpcclient != server->client)
+		status = do_proc_get_root(server->nfs_client->cl_rpcclient, fhandle, info);
+	return status;
+}
+
+/*
+ * One function for each procedure in the NFS protocol.
+ */
+static int
+nfs3_proc_getattr(struct nfs_server *server, struct nfs_fh *fhandle,
+		struct nfs_fattr *fattr, struct nfs4_label *label,
+		struct inode *inode)
+{
+	struct rpc_message msg = {
+		.rpc_proc	= &nfs3_procedures[NFS3PROC_GETATTR],
+		.rpc_argp	= fhandle,
+		.rpc_resp	= fattr,
+	};
+	int	status;
+	unsigned short task_flags = 0;
+
+	/* Is this is an attribute revalidation, subject to softreval? */
+	if (inode && (server->flags & NFS_MOUNT_SOFTREVAL))
+		task_flags |= RPC_TASK_TIMEOUT;
+
+	dprintk("NFS call  getattr\n");
+	nfs_fattr_init(fattr);
+	status = rpc_call_sync(server->client, &msg, task_flags);
+	dprintk("NFS reply getattr: %d\n", status);
+	return status;
+}
+
+static int
+nfs3_proc_setattr(struct dentry *dentry, struct nfs_fattr *fattr,
+			struct iattr *sattr)
+{
+	struct inode *inode = d_inode(dentry);
+	struct nfs3_sattrargs	arg = {
+		.fh		= NFS_FH(inode),
+		.sattr		= sattr,
+	};
+	struct rpc_message msg = {
+		.rpc_proc	= &nfs3_procedures[NFS3PROC_SETATTR],
+		.rpc_argp	= &arg,
+		.rpc_resp	= fattr,
+	};
+	int	status;
+
+	dprintk("NFS call  setattr\n");
+	if (sattr->ia_valid & ATTR_FILE)
+		msg.rpc_cred = nfs_file_cred(sattr->ia_file);
+	nfs_fattr_init(fattr);
+	status = rpc_call_sync(NFS_CLIENT(inode), &msg, 0);
+	if (status == 0) {
+		nfs_setattr_update_inode(inode, sattr, fattr);
+		if (NFS_I(inode)->cache_validity & NFS_INO_INVALID_ACL)
+			nfs_zap_acl_cache(inode);
+	}
+	dprintk("NFS reply setattr: %d\n", status);
+	return status;
+}
+
+static int
+nfs3_proc_lookup(struct inode *dir, struct dentry *dentry,
+		 struct nfs_fh *fhandle, struct nfs_fattr *fattr,
+		 struct nfs4_label *label)
+{
+	struct nfs3_diropargs	arg = {
+		.fh		= NFS_FH(dir),
+		.name		= dentry->d_name.name,
+		.len		= dentry->d_name.len
+	};
+	struct nfs3_diropres	res = {
+		.fh		= fhandle,
+		.fattr		= fattr
+	};
+	struct rpc_message msg = {
+		.rpc_proc	= &nfs3_procedures[NFS3PROC_LOOKUP],
+		.rpc_argp	= &arg,
+		.rpc_resp	= &res,
+	};
+	int			status;
+	unsigned short task_flags = 0;
+
+	/* Is this is an attribute revalidation, subject to softreval? */
+	if (nfs_lookup_is_soft_revalidate(dentry))
+		task_flags |= RPC_TASK_TIMEOUT;
+
+	res.dir_attr = nfs_alloc_fattr();
+	if (res.dir_attr == NULL)
+		return -ENOMEM;
+
+	dprintk("NFS call  lookup %pd2\n", dentry);
+	nfs_fattr_init(fattr);
+	status = rpc_call_sync(NFS_CLIENT(dir), &msg, task_flags);
+	nfs_refresh_inode(dir, res.dir_attr);
+	if (status >= 0 && !(fattr->valid & NFS_ATTR_FATTR)) {
+		msg.rpc_proc = &nfs3_procedures[NFS3PROC_GETATTR];
+		msg.rpc_argp = fhandle;
+		msg.rpc_resp = fattr;
+		status = rpc_call_sync(NFS_CLIENT(dir), &msg, task_flags);
+	}
+	nfs_free_fattr(res.dir_attr);
+	dprintk("NFS reply lookup: %d\n", status);
+	return status;
+}
+
+static int nfs3_proc_access(struct inode *inode, struct nfs_access_entry *entry)
+{
+	struct nfs3_accessargs	arg = {
+		.fh		= NFS_FH(inode),
+		.access		= entry->mask,
+	};
+	struct nfs3_accessres	res;
+	struct rpc_message msg = {
+		.rpc_proc	= &nfs3_procedures[NFS3PROC_ACCESS],
+		.rpc_argp	= &arg,
+		.rpc_resp	= &res,
+		.rpc_cred	= entry->cred,
+	};
+	int status = -ENOMEM;
+
+	dprintk("NFS call  access\n");
+	res.fattr = nfs_alloc_fattr();
+	if (res.fattr == NULL)
+		goto out;
+
+	status = rpc_call_sync(NFS_CLIENT(inode), &msg, 0);
+	nfs_refresh_inode(inode, res.fattr);
+	if (status == 0)
+		nfs_access_set_mask(entry, res.access);
+	nfs_free_fattr(res.fattr);
+out:
+	dprintk("NFS reply access: %d\n", status);
+	return status;
+}
+
+static int nfs3_proc_readlink(struct inode *inode, struct page *page,
+		unsigned int pgbase, unsigned int pglen)
+{
+	struct nfs_fattr	*fattr;
+	struct nfs3_readlinkargs args = {
+		.fh		= NFS_FH(inode),
+		.pgbase		= pgbase,
+		.pglen		= pglen,
+		.pages		= &page
+	};
+	struct rpc_message msg = {
+		.rpc_proc	= &nfs3_procedures[NFS3PROC_READLINK],
+		.rpc_argp	= &args,
+	};
+	int status = -ENOMEM;
+
+	dprintk("NFS call  readlink\n");
+	fattr = nfs_alloc_fattr();
+	if (fattr == NULL)
+		goto out;
+	msg.rpc_resp = fattr;
+
+	status = rpc_call_sync(NFS_CLIENT(inode), &msg, 0);
+	nfs_refresh_inode(inode, fattr);
+	nfs_free_fattr(fattr);
+out:
+	dprintk("NFS reply readlink: %d\n", status);
+	return status;
+}
+
+struct nfs3_createdata {
+	struct rpc_message msg;
+	union {
+		struct nfs3_createargs create;
+		struct nfs3_mkdirargs mkdir;
+		struct nfs3_symlinkargs symlink;
+		struct nfs3_mknodargs mknod;
+	} arg;
+	struct nfs3_diropres res;
+	struct nfs_fh fh;
+	struct nfs_fattr fattr;
+	struct nfs_fattr dir_attr;
+};
+
+static struct nfs3_createdata *nfs3_alloc_createdata(void)
+{
+	struct nfs3_createdata *data;
+
+	data = kzalloc(sizeof(*data), GFP_KERNEL);
+	if (data != NULL) {
+		data->msg.rpc_argp = &data->arg;
+		data->msg.rpc_resp = &data->res;
+		data->res.fh = &data->fh;
+		data->res.fattr = &data->fattr;
+		data->res.dir_attr = &data->dir_attr;
+		nfs_fattr_init(data->res.fattr);
+		nfs_fattr_init(data->res.dir_attr);
+	}
+	return data;
+}
+
+static struct dentry *
+nfs3_do_create(struct inode *dir, struct dentry *dentry, struct nfs3_createdata *data)
+{
+	int status;
+
+	status = rpc_call_sync(NFS_CLIENT(dir), &data->msg, 0);
+	nfs_post_op_update_inode(dir, data->res.dir_attr);
+	if (status != 0)
+		return ERR_PTR(status);
+
+	return nfs_add_or_obtain(dentry, data->res.fh, data->res.fattr, NULL);
+}
+
+static void nfs3_free_createdata(struct nfs3_createdata *data)
+{
+	kfree(data);
+}
+
+/*
+ * Create a regular file.
+ */
+static int
+nfs3_proc_create(struct inode *dir, struct dentry *dentry, struct iattr *sattr,
+		 int flags)
+{
+	struct posix_acl *default_acl, *acl;
+	struct nfs3_createdata *data;
+	struct dentry *d_alias;
+	int status = -ENOMEM;
+
+	dprintk("NFS call  create %pd\n", dentry);
+
+	data = nfs3_alloc_createdata();
+	if (data == NULL)
+		goto out;
+
+	data->msg.rpc_proc = &nfs3_procedures[NFS3PROC_CREATE];
+	data->arg.create.fh = NFS_FH(dir);
+	data->arg.create.name = dentry->d_name.name;
+	data->arg.create.len = dentry->d_name.len;
+	data->arg.create.sattr = sattr;
+
+	data->arg.create.createmode = NFS3_CREATE_UNCHECKED;
+	if (flags & O_EXCL) {
+		data->arg.create.createmode  = NFS3_CREATE_EXCLUSIVE;
+		data->arg.create.verifier[0] = cpu_to_be32(jiffies);
+		data->arg.create.verifier[1] = cpu_to_be32(current->pid);
+	}
+
+	status = posix_acl_create(dir, &sattr->ia_mode, &default_acl, &acl);
+	if (status)
+		goto out;
+
+	for (;;) {
+		d_alias = nfs3_do_create(dir, dentry, data);
+		status = PTR_ERR_OR_ZERO(d_alias);
+
+		if (status != -ENOTSUPP)
+			break;
+		/* If the server doesn't support the exclusive creation
+		 * semantics, try again with simple 'guarded' mode. */
+		switch (data->arg.create.createmode) {
+			case NFS3_CREATE_EXCLUSIVE:
+				data->arg.create.createmode = NFS3_CREATE_GUARDED;
+				break;
+
+			case NFS3_CREATE_GUARDED:
+				data->arg.create.createmode = NFS3_CREATE_UNCHECKED;
+				break;
+
+			case NFS3_CREATE_UNCHECKED:
+				goto out_release_acls;
+		}
+		nfs_fattr_init(data->res.dir_attr);
+		nfs_fattr_init(data->res.fattr);
+	}
+
+	if (status != 0)
+		goto out_release_acls;
+
+	if (d_alias)
+		dentry = d_alias;
+
+	/* When we created the file with exclusive semantics, make
+	 * sure we set the attributes afterwards. */
+	if (data->arg.create.createmode == NFS3_CREATE_EXCLUSIVE) {
+		dprintk("NFS call  setattr (post-create)\n");
+
+		if (!(sattr->ia_valid & ATTR_ATIME_SET))
+			sattr->ia_valid |= ATTR_ATIME;
+		if (!(sattr->ia_valid & ATTR_MTIME_SET))
+			sattr->ia_valid |= ATTR_MTIME;
+
+		/* Note: we could use a guarded setattr here, but I'm
+		 * not sure this buys us anything (and I'd have
+		 * to revamp the NFSv3 XDR code) */
+		status = nfs3_proc_setattr(dentry, data->res.fattr, sattr);
+		nfs_post_op_update_inode(d_inode(dentry), data->res.fattr);
+		dprintk("NFS reply setattr (post-create): %d\n", status);
+		if (status != 0)
+			goto out_dput;
+	}
+
+	status = nfs3_proc_setacls(d_inode(dentry), acl, default_acl);
+
+out_dput:
+	dput(d_alias);
+out_release_acls:
+	posix_acl_release(acl);
+	posix_acl_release(default_acl);
+out:
+	nfs3_free_createdata(data);
+	dprintk("NFS reply create: %d\n", status);
+	return status;
+}
+
+static int
+nfs3_proc_remove(struct inode *dir, struct dentry *dentry)
+{
+	struct nfs_removeargs arg = {
+		.fh = NFS_FH(dir),
+		.name = dentry->d_name,
+	};
+	struct nfs_removeres res;
+	struct rpc_message msg = {
+		.rpc_proc = &nfs3_procedures[NFS3PROC_REMOVE],
+		.rpc_argp = &arg,
+		.rpc_resp = &res,
+	};
+	int status = -ENOMEM;
+
+	dprintk("NFS call  remove %pd2\n", dentry);
+	res.dir_attr = nfs_alloc_fattr();
+	if (res.dir_attr == NULL)
+		goto out;
+
+	status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
+	nfs_post_op_update_inode(dir, res.dir_attr);
+	nfs_free_fattr(res.dir_attr);
+out:
+	dprintk("NFS reply remove: %d\n", status);
+	return status;
+}
+
+static void
+nfs3_proc_unlink_setup(struct rpc_message *msg,
+		struct dentry *dentry,
+		struct inode *inode)
+{
+	msg->rpc_proc = &nfs3_procedures[NFS3PROC_REMOVE];
+}
+
+static void nfs3_proc_unlink_rpc_prepare(struct rpc_task *task, struct nfs_unlinkdata *data)
+{
+	rpc_call_start(task);
+}
+
+static int
+nfs3_proc_unlink_done(struct rpc_task *task, struct inode *dir)
+{
+	struct nfs_removeres *res;
+	if (nfs3_async_handle_jukebox(task, dir))
+		return 0;
+	res = task->tk_msg.rpc_resp;
+	nfs_post_op_update_inode(dir, res->dir_attr);
+	return 1;
+}
+
+static void
+nfs3_proc_rename_setup(struct rpc_message *msg,
+		struct dentry *old_dentry,
+		struct dentry *new_dentry)
+{
+	msg->rpc_proc = &nfs3_procedures[NFS3PROC_RENAME];
+}
+
+static void nfs3_proc_rename_rpc_prepare(struct rpc_task *task, struct nfs_renamedata *data)
+{
+	rpc_call_start(task);
+}
+
+static int
+nfs3_proc_rename_done(struct rpc_task *task, struct inode *old_dir,
+		      struct inode *new_dir)
+{
+	struct nfs_renameres *res;
+
+	if (nfs3_async_handle_jukebox(task, old_dir))
+		return 0;
+	res = task->tk_msg.rpc_resp;
+
+	nfs_post_op_update_inode(old_dir, res->old_fattr);
+	nfs_post_op_update_inode(new_dir, res->new_fattr);
+	return 1;
+}
+
+static int
+nfs3_proc_link(struct inode *inode, struct inode *dir, const struct qstr *name)
+{
+	struct nfs3_linkargs	arg = {
+		.fromfh		= NFS_FH(inode),
+		.tofh		= NFS_FH(dir),
+		.toname		= name->name,
+		.tolen		= name->len
+	};
+	struct nfs3_linkres	res;
+	struct rpc_message msg = {
+		.rpc_proc	= &nfs3_procedures[NFS3PROC_LINK],
+		.rpc_argp	= &arg,
+		.rpc_resp	= &res,
+	};
+	int status = -ENOMEM;
+
+	dprintk("NFS call  link %s\n", name->name);
+	res.fattr = nfs_alloc_fattr();
+	res.dir_attr = nfs_alloc_fattr();
+	if (res.fattr == NULL || res.dir_attr == NULL)
+		goto out;
+
+	status = rpc_call_sync(NFS_CLIENT(inode), &msg, 0);
+	nfs_post_op_update_inode(dir, res.dir_attr);
+	nfs_post_op_update_inode(inode, res.fattr);
+out:
+	nfs_free_fattr(res.dir_attr);
+	nfs_free_fattr(res.fattr);
+	dprintk("NFS reply link: %d\n", status);
+	return status;
+}
+
+static int
+nfs3_proc_symlink(struct inode *dir, struct dentry *dentry, struct page *page,
+		  unsigned int len, struct iattr *sattr)
+{
+	struct nfs3_createdata *data;
+	struct dentry *d_alias;
+	int status = -ENOMEM;
+
+	if (len > NFS3_MAXPATHLEN)
+		return -ENAMETOOLONG;
+
+	dprintk("NFS call  symlink %pd\n", dentry);
+
+	data = nfs3_alloc_createdata();
+	if (data == NULL)
+		goto out;
+	data->msg.rpc_proc = &nfs3_procedures[NFS3PROC_SYMLINK];
+	data->arg.symlink.fromfh = NFS_FH(dir);
+	data->arg.symlink.fromname = dentry->d_name.name;
+	data->arg.symlink.fromlen = dentry->d_name.len;
+	data->arg.symlink.pages = &page;
+	data->arg.symlink.pathlen = len;
+	data->arg.symlink.sattr = sattr;
+
+	d_alias = nfs3_do_create(dir, dentry, data);
+	status = PTR_ERR_OR_ZERO(d_alias);
+
+	if (status == 0)
+		dput(d_alias);
+
+	nfs3_free_createdata(data);
+out:
+	dprintk("NFS reply symlink: %d\n", status);
+	return status;
+}
+
+static int
+nfs3_proc_mkdir(struct inode *dir, struct dentry *dentry, struct iattr *sattr)
+{
+	struct posix_acl *default_acl, *acl;
+	struct nfs3_createdata *data;
+	struct dentry *d_alias;
+	int status = -ENOMEM;
+
+	dprintk("NFS call  mkdir %pd\n", dentry);
+
+	data = nfs3_alloc_createdata();
+	if (data == NULL)
+		goto out;
+
+	status = posix_acl_create(dir, &sattr->ia_mode, &default_acl, &acl);
+	if (status)
+		goto out;
+
+	data->msg.rpc_proc = &nfs3_procedures[NFS3PROC_MKDIR];
+	data->arg.mkdir.fh = NFS_FH(dir);
+	data->arg.mkdir.name = dentry->d_name.name;
+	data->arg.mkdir.len = dentry->d_name.len;
+	data->arg.mkdir.sattr = sattr;
+
+	d_alias = nfs3_do_create(dir, dentry, data);
+	status = PTR_ERR_OR_ZERO(d_alias);
+
+	if (status != 0)
+		goto out_release_acls;
+
+	if (d_alias)
+		dentry = d_alias;
+
+	status = nfs3_proc_setacls(d_inode(dentry), acl, default_acl);
+
+	dput(d_alias);
+out_release_acls:
+	posix_acl_release(acl);
+	posix_acl_release(default_acl);
+out:
+	nfs3_free_createdata(data);
+	dprintk("NFS reply mkdir: %d\n", status);
+	return status;
+}
+
+static int
+nfs3_proc_rmdir(struct inode *dir, const struct qstr *name)
+{
+	struct nfs_fattr	*dir_attr;
+	struct nfs3_diropargs	arg = {
+		.fh		= NFS_FH(dir),
+		.name		= name->name,
+		.len		= name->len
+	};
+	struct rpc_message msg = {
+		.rpc_proc	= &nfs3_procedures[NFS3PROC_RMDIR],
+		.rpc_argp	= &arg,
+	};
+	int status = -ENOMEM;
+
+	dprintk("NFS call  rmdir %s\n", name->name);
+	dir_attr = nfs_alloc_fattr();
+	if (dir_attr == NULL)
+		goto out;
+
+	msg.rpc_resp = dir_attr;
+	status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
+	nfs_post_op_update_inode(dir, dir_attr);
+	nfs_free_fattr(dir_attr);
+out:
+	dprintk("NFS reply rmdir: %d\n", status);
+	return status;
+}
+
+/*
+ * The READDIR implementation is somewhat hackish - we pass the user buffer
+ * to the encode function, which installs it in the receive iovec.
+ * The decode function itself doesn't perform any decoding, it just makes
+ * sure the reply is syntactically correct.
+ *
+ * Also note that this implementation handles both plain readdir and
+ * readdirplus.
+ */
+static int
+nfs3_proc_readdir(struct dentry *dentry, const struct cred *cred,
+		  u64 cookie, struct page **pages, unsigned int count, bool plus)
+{
+	struct inode		*dir = d_inode(dentry);
+	__be32			*verf = NFS_I(dir)->cookieverf;
+	struct nfs3_readdirargs	arg = {
+		.fh		= NFS_FH(dir),
+		.cookie		= cookie,
+		.verf		= {verf[0], verf[1]},
+		.plus		= plus,
+		.count		= count,
+		.pages		= pages
+	};
+	struct nfs3_readdirres	res = {
+		.verf		= verf,
+		.plus		= plus
+	};
+	struct rpc_message	msg = {
+		.rpc_proc	= &nfs3_procedures[NFS3PROC_READDIR],
+		.rpc_argp	= &arg,
+		.rpc_resp	= &res,
+		.rpc_cred	= cred,
+	};
+	int status = -ENOMEM;
+
+	if (plus)
+		msg.rpc_proc = &nfs3_procedures[NFS3PROC_READDIRPLUS];
+
+	dprintk("NFS call  readdir%s %d\n",
+			plus? "plus" : "", (unsigned int) cookie);
+
+	res.dir_attr = nfs_alloc_fattr();
+	if (res.dir_attr == NULL)
+		goto out;
+
+	status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
+
+	nfs_invalidate_atime(dir);
+	nfs_refresh_inode(dir, res.dir_attr);
+
+	nfs_free_fattr(res.dir_attr);
+out:
+	dprintk("NFS reply readdir%s: %d\n",
+			plus? "plus" : "", status);
+	return status;
+}
+
+static int
+nfs3_proc_mknod(struct inode *dir, struct dentry *dentry, struct iattr *sattr,
+		dev_t rdev)
+{
+	struct posix_acl *default_acl, *acl;
+	struct nfs3_createdata *data;
+	struct dentry *d_alias;
+	int status = -ENOMEM;
+
+	dprintk("NFS call  mknod %pd %u:%u\n", dentry,
+			MAJOR(rdev), MINOR(rdev));
+
+	data = nfs3_alloc_createdata();
+	if (data == NULL)
+		goto out;
+
+	status = posix_acl_create(dir, &sattr->ia_mode, &default_acl, &acl);
+	if (status)
+		goto out;
+
+	data->msg.rpc_proc = &nfs3_procedures[NFS3PROC_MKNOD];
+	data->arg.mknod.fh = NFS_FH(dir);
+	data->arg.mknod.name = dentry->d_name.name;
+	data->arg.mknod.len = dentry->d_name.len;
+	data->arg.mknod.sattr = sattr;
+	data->arg.mknod.rdev = rdev;
+
+	switch (sattr->ia_mode & S_IFMT) {
+	case S_IFBLK:
+		data->arg.mknod.type = NF3BLK;
+		break;
+	case S_IFCHR:
+		data->arg.mknod.type = NF3CHR;
+		break;
+	case S_IFIFO:
+		data->arg.mknod.type = NF3FIFO;
+		break;
+	case S_IFSOCK:
+		data->arg.mknod.type = NF3SOCK;
+		break;
+	default:
+		status = -EINVAL;
+		goto out_release_acls;
+	}
+
+	d_alias = nfs3_do_create(dir, dentry, data);
+	status = PTR_ERR_OR_ZERO(d_alias);
+	if (status != 0)
+		goto out_release_acls;
+
+	if (d_alias)
+		dentry = d_alias;
+
+	status = nfs3_proc_setacls(d_inode(dentry), acl, default_acl);
+
+	dput(d_alias);
+out_release_acls:
+	posix_acl_release(acl);
+	posix_acl_release(default_acl);
+out:
+	nfs3_free_createdata(data);
+	dprintk("NFS reply mknod: %d\n", status);
+	return status;
+}
+
+static int
+nfs3_proc_statfs(struct nfs_server *server, struct nfs_fh *fhandle,
+		 struct nfs_fsstat *stat)
+{
+	struct rpc_message msg = {
+		.rpc_proc	= &nfs3_procedures[NFS3PROC_FSSTAT],
+		.rpc_argp	= fhandle,
+		.rpc_resp	= stat,
+	};
+	int	status;
+
+	dprintk("NFS call  fsstat\n");
+	nfs_fattr_init(stat->fattr);
+	status = rpc_call_sync(server->client, &msg, 0);
+	dprintk("NFS reply fsstat: %d\n", status);
+	return status;
+}
+
+static int
+do_proc_fsinfo(struct rpc_clnt *client, struct nfs_fh *fhandle,
+		 struct nfs_fsinfo *info)
+{
+	struct rpc_message msg = {
+		.rpc_proc	= &nfs3_procedures[NFS3PROC_FSINFO],
+		.rpc_argp	= fhandle,
+		.rpc_resp	= info,
+	};
+	int	status;
+
+	dprintk("NFS call  fsinfo\n");
+	nfs_fattr_init(info->fattr);
+	status = rpc_call_sync(client, &msg, 0);
+	dprintk("NFS reply fsinfo: %d\n", status);
+	return status;
+}
+
+/*
+ * Bare-bones access to fsinfo: this is for nfs_get_root/nfs_get_sb via
+ * nfs_create_server
+ */
+static int
+nfs3_proc_fsinfo(struct nfs_server *server, struct nfs_fh *fhandle,
+		   struct nfs_fsinfo *info)
+{
+	int	status;
+
+	status = do_proc_fsinfo(server->client, fhandle, info);
+	if (status && server->nfs_client->cl_rpcclient != server->client)
+		status = do_proc_fsinfo(server->nfs_client->cl_rpcclient, fhandle, info);
+	return status;
+}
+
+static int
+nfs3_proc_pathconf(struct nfs_server *server, struct nfs_fh *fhandle,
+		   struct nfs_pathconf *info)
+{
+	struct rpc_message msg = {
+		.rpc_proc	= &nfs3_procedures[NFS3PROC_PATHCONF],
+		.rpc_argp	= fhandle,
+		.rpc_resp	= info,
+	};
+	int	status;
+
+	dprintk("NFS call  pathconf\n");
+	nfs_fattr_init(info->fattr);
+	status = rpc_call_sync(server->client, &msg, 0);
+	dprintk("NFS reply pathconf: %d\n", status);
+	return status;
+}
+
+static int nfs3_read_done(struct rpc_task *task, struct nfs_pgio_header *hdr)
+{
+	struct inode *inode = hdr->inode;
+	struct nfs_server *server = NFS_SERVER(inode);
+
+	if (hdr->pgio_done_cb != NULL)
+		return hdr->pgio_done_cb(task, hdr);
+
+	if (nfs3_async_handle_jukebox(task, inode))
+		return -EAGAIN;
+
+	if (task->tk_status >= 0 && !server->read_hdrsize)
+		cmpxchg(&server->read_hdrsize, 0, hdr->res.replen);
+
+	nfs_invalidate_atime(inode);
+	nfs_refresh_inode(inode, &hdr->fattr);
+	return 0;
+}
+
+static void nfs3_proc_read_setup(struct nfs_pgio_header *hdr,
+				 struct rpc_message *msg)
+{
+	msg->rpc_proc = &nfs3_procedures[NFS3PROC_READ];
+	hdr->args.replen = NFS_SERVER(hdr->inode)->read_hdrsize;
+}
+
+static int nfs3_proc_pgio_rpc_prepare(struct rpc_task *task,
+				      struct nfs_pgio_header *hdr)
+{
+	rpc_call_start(task);
+	return 0;
+}
+
+static int nfs3_write_done(struct rpc_task *task, struct nfs_pgio_header *hdr)
+{
+	struct inode *inode = hdr->inode;
+
+	if (hdr->pgio_done_cb != NULL)
+		return hdr->pgio_done_cb(task, hdr);
+
+	if (nfs3_async_handle_jukebox(task, inode))
+		return -EAGAIN;
+	if (task->tk_status >= 0)
+		nfs_writeback_update_inode(hdr);
+	return 0;
+}
+
+static void nfs3_proc_write_setup(struct nfs_pgio_header *hdr,
+				  struct rpc_message *msg,
+				  struct rpc_clnt **clnt)
+{
+	msg->rpc_proc = &nfs3_procedures[NFS3PROC_WRITE];
+}
+
+static void nfs3_proc_commit_rpc_prepare(struct rpc_task *task, struct nfs_commit_data *data)
+{
+	rpc_call_start(task);
+}
+
+static int nfs3_commit_done(struct rpc_task *task, struct nfs_commit_data *data)
+{
+	if (data->commit_done_cb != NULL)
+		return data->commit_done_cb(task, data);
+
+	if (nfs3_async_handle_jukebox(task, data->inode))
+		return -EAGAIN;
+	nfs_refresh_inode(data->inode, data->res.fattr);
+	return 0;
+}
+
+static void nfs3_proc_commit_setup(struct nfs_commit_data *data, struct rpc_message *msg,
+				   struct rpc_clnt **clnt)
+{
+	msg->rpc_proc = &nfs3_procedures[NFS3PROC_COMMIT];
+}
+
+static void nfs3_nlm_alloc_call(void *data)
+{
+	struct nfs_lock_context *l_ctx = data;
+	if (l_ctx && test_bit(NFS_CONTEXT_UNLOCK, &l_ctx->open_context->flags)) {
+		get_nfs_open_context(l_ctx->open_context);
+		nfs_get_lock_context(l_ctx->open_context);
+	}
+}
+
+static bool nfs3_nlm_unlock_prepare(struct rpc_task *task, void *data)
+{
+	struct nfs_lock_context *l_ctx = data;
+	if (l_ctx && test_bit(NFS_CONTEXT_UNLOCK, &l_ctx->open_context->flags))
+		return nfs_async_iocounter_wait(task, l_ctx);
+	return false;
+
+}
+
+static void nfs3_nlm_release_call(void *data)
+{
+	struct nfs_lock_context *l_ctx = data;
+	struct nfs_open_context *ctx;
+	if (l_ctx && test_bit(NFS_CONTEXT_UNLOCK, &l_ctx->open_context->flags)) {
+		ctx = l_ctx->open_context;
+		nfs_put_lock_context(l_ctx);
+		put_nfs_open_context(ctx);
+	}
+}
+
+static const struct nlmclnt_operations nlmclnt_fl_close_lock_ops = {
+	.nlmclnt_alloc_call = nfs3_nlm_alloc_call,
+	.nlmclnt_unlock_prepare = nfs3_nlm_unlock_prepare,
+	.nlmclnt_release_call = nfs3_nlm_release_call,
+};
+
+static int
+nfs3_proc_lock(struct file *filp, int cmd, struct file_lock *fl)
+{
+	struct inode *inode = file_inode(filp);
+	struct nfs_lock_context *l_ctx = NULL;
+	struct nfs_open_context *ctx = nfs_file_open_context(filp);
+	int status;
+
+	if (fl->fl_flags & FL_CLOSE) {
+		l_ctx = nfs_get_lock_context(ctx);
+		if (IS_ERR(l_ctx))
+			l_ctx = NULL;
+		else
+			set_bit(NFS_CONTEXT_UNLOCK, &ctx->flags);
+	}
+
+	status = nlmclnt_proc(NFS_SERVER(inode)->nlm_host, cmd, fl, l_ctx);
+
+	if (l_ctx)
+		nfs_put_lock_context(l_ctx);
+
+	return status;
+}
+
+static int nfs3_have_delegation(struct inode *inode, fmode_t flags)
+{
+	return 0;
+}
+
+static const struct inode_operations nfs3_dir_inode_operations = {
+	.create		= nfs_create,
+	.lookup		= nfs_lookup,
+	.link		= nfs_link,
+	.unlink		= nfs_unlink,
+	.symlink	= nfs_symlink,
+	.mkdir		= nfs_mkdir,
+	.rmdir		= nfs_rmdir,
+	.mknod		= nfs_mknod,
+	.rename		= nfs_rename,
+	.permission	= nfs_permission,
+	.getattr	= nfs_getattr,
+	.setattr	= nfs_setattr,
+#ifdef CONFIG_NFS_V3_ACL
+	.listxattr	= nfs3_listxattr,
+	.get_acl	= nfs3_get_acl,
+	.set_acl	= nfs3_set_acl,
+#endif
+};
+
+static const struct inode_operations nfs3_file_inode_operations = {
+	.permission	= nfs_permission,
+	.getattr	= nfs_getattr,
+	.setattr	= nfs_setattr,
+#ifdef CONFIG_NFS_V3_ACL
+	.listxattr	= nfs3_listxattr,
+	.get_acl	= nfs3_get_acl,
+	.set_acl	= nfs3_set_acl,
+#endif
+};
+
+const struct nfs_rpc_ops nfs_v3_clientops = {
+	.version	= 3,			/* protocol version */
+	.dentry_ops	= &nfs_dentry_operations,
+	.dir_inode_ops	= &nfs3_dir_inode_operations,
+	.file_inode_ops	= &nfs3_file_inode_operations,
+	.file_ops	= &nfs_file_operations,
+	.nlmclnt_ops	= &nlmclnt_fl_close_lock_ops,
+	.getroot	= nfs3_proc_get_root,
+	.submount	= nfs_submount,
+	.try_get_tree	= nfs_try_get_tree,
+	.getattr	= nfs3_proc_getattr,
+	.setattr	= nfs3_proc_setattr,
+	.lookup		= nfs3_proc_lookup,
+	.access		= nfs3_proc_access,
+	.readlink	= nfs3_proc_readlink,
+	.create		= nfs3_proc_create,
+	.remove		= nfs3_proc_remove,
+	.unlink_setup	= nfs3_proc_unlink_setup,
+	.unlink_rpc_prepare = nfs3_proc_unlink_rpc_prepare,
+	.unlink_done	= nfs3_proc_unlink_done,
+	.rename_setup	= nfs3_proc_rename_setup,
+	.rename_rpc_prepare = nfs3_proc_rename_rpc_prepare,
+	.rename_done	= nfs3_proc_rename_done,
+	.link		= nfs3_proc_link,
+	.symlink	= nfs3_proc_symlink,
+	.mkdir		= nfs3_proc_mkdir,
+	.rmdir		= nfs3_proc_rmdir,
+	.readdir	= nfs3_proc_readdir,
+	.mknod		= nfs3_proc_mknod,
+	.statfs		= nfs3_proc_statfs,
+	.fsinfo		= nfs3_proc_fsinfo,
+	.pathconf	= nfs3_proc_pathconf,
+	.decode_dirent	= nfs3_decode_dirent,
+	.pgio_rpc_prepare = nfs3_proc_pgio_rpc_prepare,
+	.read_setup	= nfs3_proc_read_setup,
+	.read_done	= nfs3_read_done,
+	.write_setup	= nfs3_proc_write_setup,
+	.write_done	= nfs3_write_done,
+	.commit_setup	= nfs3_proc_commit_setup,
+	.commit_rpc_prepare = nfs3_proc_commit_rpc_prepare,
+	.commit_done	= nfs3_commit_done,
+	.lock		= nfs3_proc_lock,
+	.clear_acl_cache = forget_all_cached_acls,
+	.close_context	= nfs_close_context,
+	.have_delegation = nfs3_have_delegation,
+	.alloc_client	= nfs_alloc_client,
+	.init_client	= nfs_init_client,
+	.free_client	= nfs_free_client,
+	.create_server	= nfs3_create_server,
+	.clone_server	= nfs3_clone_server,
+};
diff --git a/fs/nfs/nfs3super.c b/fs/nfs/nfs3super.c
new file mode 100644
index 000000000..7c5809431
--- /dev/null
+++ b/fs/nfs/nfs3super.c
@@ -0,0 +1,36 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2012 Netapp, Inc. All rights reserved.
+ */
+#include <linux/module.h>
+#include <linux/nfs_fs.h>
+#include "internal.h"
+#include "nfs3_fs.h"
+#include "nfs.h"
+
+struct nfs_subversion nfs_v3 = {
+	.owner = THIS_MODULE,
+	.nfs_fs   = &nfs_fs_type,
+	.rpc_vers = &nfs_version3,
+	.rpc_ops  = &nfs_v3_clientops,
+	.sops     = &nfs_sops,
+#ifdef CONFIG_NFS_V3_ACL
+	.xattr    = nfs3_xattr_handlers,
+#endif
+};
+
+static int __init init_nfs_v3(void)
+{
+	register_nfs_version(&nfs_v3);
+	return 0;
+}
+
+static void __exit exit_nfs_v3(void)
+{
+	unregister_nfs_version(&nfs_v3);
+}
+
+MODULE_LICENSE("GPL");
+
+module_init(init_nfs_v3);
+module_exit(exit_nfs_v3);
diff --git a/fs/nfs/nfs3xdr.c b/fs/nfs/nfs3xdr.c
new file mode 100644
index 000000000..509f32845
--- /dev/null
+++ b/fs/nfs/nfs3xdr.c
@@ -0,0 +1,2576 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/nfs/nfs3xdr.c
+ *
+ * XDR functions to encode/decode NFSv3 RPC arguments and results.
+ *
+ * Copyright (C) 1996, 1997 Olaf Kirch
+ */
+
+#include <linux/param.h>
+#include <linux/time.h>
+#include <linux/mm.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/in.h>
+#include <linux/pagemap.h>
+#include <linux/proc_fs.h>
+#include <linux/kdev_t.h>
+#include <linux/sunrpc/clnt.h>
+#include <linux/nfs.h>
+#include <linux/nfs3.h>
+#include <linux/nfs_fs.h>
+#include <linux/nfsacl.h>
+#include "nfstrace.h"
+#include "internal.h"
+
+#define NFSDBG_FACILITY		NFSDBG_XDR
+
+/* Mapping from NFS error code to "errno" error code. */
+#define errno_NFSERR_IO		EIO
+
+/*
+ * Declare the space requirements for NFS arguments and replies as
+ * number of 32bit-words
+ */
+#define NFS3_fhandle_sz		(1+16)
+#define NFS3_fh_sz		(NFS3_fhandle_sz)	/* shorthand */
+#define NFS3_post_op_fh_sz	(1+NFS3_fh_sz)
+#define NFS3_sattr_sz		(15)
+#define NFS3_filename_sz	(1+(NFS3_MAXNAMLEN>>2))
+#define NFS3_path_sz		(1+(NFS3_MAXPATHLEN>>2))
+#define NFS3_fattr_sz		(21)
+#define NFS3_cookieverf_sz	(NFS3_COOKIEVERFSIZE>>2)
+#define NFS3_wcc_attr_sz	(6)
+#define NFS3_pre_op_attr_sz	(1+NFS3_wcc_attr_sz)
+#define NFS3_post_op_attr_sz	(1+NFS3_fattr_sz)
+#define NFS3_wcc_data_sz	(NFS3_pre_op_attr_sz+NFS3_post_op_attr_sz)
+#define NFS3_diropargs_sz	(NFS3_fh_sz+NFS3_filename_sz)
+
+#define NFS3_getattrargs_sz	(NFS3_fh_sz)
+#define NFS3_setattrargs_sz	(NFS3_fh_sz+NFS3_sattr_sz+3)
+#define NFS3_lookupargs_sz	(NFS3_fh_sz+NFS3_filename_sz)
+#define NFS3_accessargs_sz	(NFS3_fh_sz+1)
+#define NFS3_readlinkargs_sz	(NFS3_fh_sz)
+#define NFS3_readargs_sz	(NFS3_fh_sz+3)
+#define NFS3_writeargs_sz	(NFS3_fh_sz+5)
+#define NFS3_createargs_sz	(NFS3_diropargs_sz+NFS3_sattr_sz)
+#define NFS3_mkdirargs_sz	(NFS3_diropargs_sz+NFS3_sattr_sz)
+#define NFS3_symlinkargs_sz	(NFS3_diropargs_sz+1+NFS3_sattr_sz)
+#define NFS3_mknodargs_sz	(NFS3_diropargs_sz+2+NFS3_sattr_sz)
+#define NFS3_removeargs_sz	(NFS3_fh_sz+NFS3_filename_sz)
+#define NFS3_renameargs_sz	(NFS3_diropargs_sz+NFS3_diropargs_sz)
+#define NFS3_linkargs_sz		(NFS3_fh_sz+NFS3_diropargs_sz)
+#define NFS3_readdirargs_sz	(NFS3_fh_sz+NFS3_cookieverf_sz+3)
+#define NFS3_readdirplusargs_sz	(NFS3_fh_sz+NFS3_cookieverf_sz+4)
+#define NFS3_commitargs_sz	(NFS3_fh_sz+3)
+
+#define NFS3_getattrres_sz	(1+NFS3_fattr_sz)
+#define NFS3_setattrres_sz	(1+NFS3_wcc_data_sz)
+#define NFS3_removeres_sz	(NFS3_setattrres_sz)
+#define NFS3_lookupres_sz	(1+NFS3_fh_sz+(2 * NFS3_post_op_attr_sz))
+#define NFS3_accessres_sz	(1+NFS3_post_op_attr_sz+1)
+#define NFS3_readlinkres_sz	(1+NFS3_post_op_attr_sz+1+1)
+#define NFS3_readres_sz		(1+NFS3_post_op_attr_sz+3+1)
+#define NFS3_writeres_sz	(1+NFS3_wcc_data_sz+4)
+#define NFS3_createres_sz	(1+NFS3_post_op_fh_sz+NFS3_post_op_attr_sz+NFS3_wcc_data_sz)
+#define NFS3_renameres_sz	(1+(2 * NFS3_wcc_data_sz))
+#define NFS3_linkres_sz		(1+NFS3_post_op_attr_sz+NFS3_wcc_data_sz)
+#define NFS3_readdirres_sz	(1+NFS3_post_op_attr_sz+2+1)
+#define NFS3_fsstatres_sz	(1+NFS3_post_op_attr_sz+13)
+#define NFS3_fsinfores_sz	(1+NFS3_post_op_attr_sz+12)
+#define NFS3_pathconfres_sz	(1+NFS3_post_op_attr_sz+6)
+#define NFS3_commitres_sz	(1+NFS3_wcc_data_sz+2)
+
+#define ACL3_getaclargs_sz	(NFS3_fh_sz+1)
+#define ACL3_setaclargs_sz	(NFS3_fh_sz+1+ \
+				XDR_QUADLEN(NFS_ACL_INLINE_BUFSIZE))
+#define ACL3_getaclres_sz	(1+NFS3_post_op_attr_sz+1+ \
+				XDR_QUADLEN(NFS_ACL_INLINE_BUFSIZE)+1)
+#define ACL3_setaclres_sz	(1+NFS3_post_op_attr_sz)
+
+static int nfs3_stat_to_errno(enum nfs_stat);
+
+/*
+ * Map file type to S_IFMT bits
+ */
+static const umode_t nfs_type2fmt[] = {
+	[NF3BAD] = 0,
+	[NF3REG] = S_IFREG,
+	[NF3DIR] = S_IFDIR,
+	[NF3BLK] = S_IFBLK,
+	[NF3CHR] = S_IFCHR,
+	[NF3LNK] = S_IFLNK,
+	[NF3SOCK] = S_IFSOCK,
+	[NF3FIFO] = S_IFIFO,
+};
+
+static struct user_namespace *rpc_userns(const struct rpc_clnt *clnt)
+{
+	if (clnt && clnt->cl_cred)
+		return clnt->cl_cred->user_ns;
+	return &init_user_ns;
+}
+
+static struct user_namespace *rpc_rqst_userns(const struct rpc_rqst *rqstp)
+{
+	if (rqstp->rq_task)
+		return rpc_userns(rqstp->rq_task->tk_client);
+	return &init_user_ns;
+}
+
+/*
+ * Encode/decode NFSv3 basic data types
+ *
+ * Basic NFSv3 data types are defined in section 2.5 of RFC 1813:
+ * "NFS Version 3 Protocol Specification".
+ *
+ * Not all basic data types have their own encoding and decoding
+ * functions.  For run-time efficiency, some data types are encoded
+ * or decoded inline.
+ */
+
+static void encode_uint32(struct xdr_stream *xdr, u32 value)
+{
+	__be32 *p = xdr_reserve_space(xdr, 4);
+	*p = cpu_to_be32(value);
+}
+
+static int decode_uint32(struct xdr_stream *xdr, u32 *value)
+{
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(!p))
+		return -EIO;
+	*value = be32_to_cpup(p);
+	return 0;
+}
+
+static int decode_uint64(struct xdr_stream *xdr, u64 *value)
+{
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, 8);
+	if (unlikely(!p))
+		return -EIO;
+	xdr_decode_hyper(p, value);
+	return 0;
+}
+
+/*
+ * fileid3
+ *
+ *	typedef uint64 fileid3;
+ */
+static __be32 *xdr_decode_fileid3(__be32 *p, u64 *fileid)
+{
+	return xdr_decode_hyper(p, fileid);
+}
+
+static int decode_fileid3(struct xdr_stream *xdr, u64 *fileid)
+{
+	return decode_uint64(xdr, fileid);
+}
+
+/*
+ * filename3
+ *
+ *	typedef string filename3<>;
+ */
+static void encode_filename3(struct xdr_stream *xdr,
+			     const char *name, u32 length)
+{
+	__be32 *p;
+
+	WARN_ON_ONCE(length > NFS3_MAXNAMLEN);
+	p = xdr_reserve_space(xdr, 4 + length);
+	xdr_encode_opaque(p, name, length);
+}
+
+static int decode_inline_filename3(struct xdr_stream *xdr,
+				   const char **name, u32 *length)
+{
+	__be32 *p;
+	u32 count;
+
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(!p))
+		return -EIO;
+	count = be32_to_cpup(p);
+	if (count > NFS3_MAXNAMLEN)
+		goto out_nametoolong;
+	p = xdr_inline_decode(xdr, count);
+	if (unlikely(!p))
+		return -EIO;
+	*name = (const char *)p;
+	*length = count;
+	return 0;
+
+out_nametoolong:
+	dprintk("NFS: returned filename too long: %u\n", count);
+	return -ENAMETOOLONG;
+}
+
+/*
+ * nfspath3
+ *
+ *	typedef string nfspath3<>;
+ */
+static void encode_nfspath3(struct xdr_stream *xdr, struct page **pages,
+			    const u32 length)
+{
+	encode_uint32(xdr, length);
+	xdr_write_pages(xdr, pages, 0, length);
+}
+
+static int decode_nfspath3(struct xdr_stream *xdr)
+{
+	u32 recvd, count;
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(!p))
+		return -EIO;
+	count = be32_to_cpup(p);
+	if (unlikely(count >= xdr->buf->page_len || count > NFS3_MAXPATHLEN))
+		goto out_nametoolong;
+	recvd = xdr_read_pages(xdr, count);
+	if (unlikely(count > recvd))
+		goto out_cheating;
+	xdr_terminate_string(xdr->buf, count);
+	return 0;
+
+out_nametoolong:
+	dprintk("NFS: returned pathname too long: %u\n", count);
+	return -ENAMETOOLONG;
+out_cheating:
+	dprintk("NFS: server cheating in pathname result: "
+		"count %u > recvd %u\n", count, recvd);
+	return -EIO;
+}
+
+/*
+ * cookie3
+ *
+ *	typedef uint64 cookie3
+ */
+static __be32 *xdr_encode_cookie3(__be32 *p, u64 cookie)
+{
+	return xdr_encode_hyper(p, cookie);
+}
+
+static int decode_cookie3(struct xdr_stream *xdr, u64 *cookie)
+{
+	return decode_uint64(xdr, cookie);
+}
+
+/*
+ * cookieverf3
+ *
+ *	typedef opaque cookieverf3[NFS3_COOKIEVERFSIZE];
+ */
+static __be32 *xdr_encode_cookieverf3(__be32 *p, const __be32 *verifier)
+{
+	memcpy(p, verifier, NFS3_COOKIEVERFSIZE);
+	return p + XDR_QUADLEN(NFS3_COOKIEVERFSIZE);
+}
+
+static int decode_cookieverf3(struct xdr_stream *xdr, __be32 *verifier)
+{
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, NFS3_COOKIEVERFSIZE);
+	if (unlikely(!p))
+		return -EIO;
+	memcpy(verifier, p, NFS3_COOKIEVERFSIZE);
+	return 0;
+}
+
+/*
+ * createverf3
+ *
+ *	typedef opaque createverf3[NFS3_CREATEVERFSIZE];
+ */
+static void encode_createverf3(struct xdr_stream *xdr, const __be32 *verifier)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, NFS3_CREATEVERFSIZE);
+	memcpy(p, verifier, NFS3_CREATEVERFSIZE);
+}
+
+static int decode_writeverf3(struct xdr_stream *xdr, struct nfs_write_verifier *verifier)
+{
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, NFS3_WRITEVERFSIZE);
+	if (unlikely(!p))
+		return -EIO;
+	memcpy(verifier->data, p, NFS3_WRITEVERFSIZE);
+	return 0;
+}
+
+/*
+ * size3
+ *
+ *	typedef uint64 size3;
+ */
+static __be32 *xdr_decode_size3(__be32 *p, u64 *size)
+{
+	return xdr_decode_hyper(p, size);
+}
+
+/*
+ * nfsstat3
+ *
+ *	enum nfsstat3 {
+ *		NFS3_OK = 0,
+ *		...
+ *	}
+ */
+#define NFS3_OK		NFS_OK
+
+static int decode_nfsstat3(struct xdr_stream *xdr, enum nfs_stat *status)
+{
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(!p))
+		return -EIO;
+	if (unlikely(*p != cpu_to_be32(NFS3_OK)))
+		goto out_status;
+	*status = 0;
+	return 0;
+out_status:
+	*status = be32_to_cpup(p);
+	trace_nfs_xdr_status(xdr, (int)*status);
+	return 0;
+}
+
+/*
+ * ftype3
+ *
+ *	enum ftype3 {
+ *		NF3REG	= 1,
+ *		NF3DIR	= 2,
+ *		NF3BLK	= 3,
+ *		NF3CHR	= 4,
+ *		NF3LNK	= 5,
+ *		NF3SOCK	= 6,
+ *		NF3FIFO	= 7
+ *	};
+ */
+static void encode_ftype3(struct xdr_stream *xdr, const u32 type)
+{
+	encode_uint32(xdr, type);
+}
+
+static __be32 *xdr_decode_ftype3(__be32 *p, umode_t *mode)
+{
+	u32 type;
+
+	type = be32_to_cpup(p++);
+	if (type > NF3FIFO)
+		type = NF3NON;
+	*mode = nfs_type2fmt[type];
+	return p;
+}
+
+/*
+ * specdata3
+ *
+ *     struct specdata3 {
+ *             uint32  specdata1;
+ *             uint32  specdata2;
+ *     };
+ */
+static void encode_specdata3(struct xdr_stream *xdr, const dev_t rdev)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 8);
+	*p++ = cpu_to_be32(MAJOR(rdev));
+	*p = cpu_to_be32(MINOR(rdev));
+}
+
+static __be32 *xdr_decode_specdata3(__be32 *p, dev_t *rdev)
+{
+	unsigned int major, minor;
+
+	major = be32_to_cpup(p++);
+	minor = be32_to_cpup(p++);
+	*rdev = MKDEV(major, minor);
+	if (MAJOR(*rdev) != major || MINOR(*rdev) != minor)
+		*rdev = 0;
+	return p;
+}
+
+/*
+ * nfs_fh3
+ *
+ *	struct nfs_fh3 {
+ *		opaque       data<NFS3_FHSIZE>;
+ *	};
+ */
+static void encode_nfs_fh3(struct xdr_stream *xdr, const struct nfs_fh *fh)
+{
+	__be32 *p;
+
+	WARN_ON_ONCE(fh->size > NFS3_FHSIZE);
+	p = xdr_reserve_space(xdr, 4 + fh->size);
+	xdr_encode_opaque(p, fh->data, fh->size);
+}
+
+static int decode_nfs_fh3(struct xdr_stream *xdr, struct nfs_fh *fh)
+{
+	u32 length;
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(!p))
+		return -EIO;
+	length = be32_to_cpup(p++);
+	if (unlikely(length > NFS3_FHSIZE))
+		goto out_toobig;
+	p = xdr_inline_decode(xdr, length);
+	if (unlikely(!p))
+		return -EIO;
+	fh->size = length;
+	memcpy(fh->data, p, length);
+	return 0;
+out_toobig:
+	dprintk("NFS: file handle size (%u) too big\n", length);
+	return -E2BIG;
+}
+
+static void zero_nfs_fh3(struct nfs_fh *fh)
+{
+	memset(fh, 0, sizeof(*fh));
+}
+
+/*
+ * nfstime3
+ *
+ *	struct nfstime3 {
+ *		uint32	seconds;
+ *		uint32	nseconds;
+ *	};
+ */
+static __be32 *xdr_encode_nfstime3(__be32 *p, const struct timespec64 *timep)
+{
+	*p++ = cpu_to_be32((u32)timep->tv_sec);
+	*p++ = cpu_to_be32(timep->tv_nsec);
+	return p;
+}
+
+static __be32 *xdr_decode_nfstime3(__be32 *p, struct timespec64 *timep)
+{
+	timep->tv_sec = be32_to_cpup(p++);
+	timep->tv_nsec = be32_to_cpup(p++);
+	return p;
+}
+
+/*
+ * sattr3
+ *
+ *	enum time_how {
+ *		DONT_CHANGE		= 0,
+ *		SET_TO_SERVER_TIME	= 1,
+ *		SET_TO_CLIENT_TIME	= 2
+ *	};
+ *
+ *	union set_mode3 switch (bool set_it) {
+ *	case TRUE:
+ *		mode3	mode;
+ *	default:
+ *		void;
+ *	};
+ *
+ *	union set_uid3 switch (bool set_it) {
+ *	case TRUE:
+ *		uid3	uid;
+ *	default:
+ *		void;
+ *	};
+ *
+ *	union set_gid3 switch (bool set_it) {
+ *	case TRUE:
+ *		gid3	gid;
+ *	default:
+ *		void;
+ *	};
+ *
+ *	union set_size3 switch (bool set_it) {
+ *	case TRUE:
+ *		size3	size;
+ *	default:
+ *		void;
+ *	};
+ *
+ *	union set_atime switch (time_how set_it) {
+ *	case SET_TO_CLIENT_TIME:
+ *		nfstime3	atime;
+ *	default:
+ *		void;
+ *	};
+ *
+ *	union set_mtime switch (time_how set_it) {
+ *	case SET_TO_CLIENT_TIME:
+ *		nfstime3  mtime;
+ *	default:
+ *		void;
+ *	};
+ *
+ *	struct sattr3 {
+ *		set_mode3	mode;
+ *		set_uid3	uid;
+ *		set_gid3	gid;
+ *		set_size3	size;
+ *		set_atime	atime;
+ *		set_mtime	mtime;
+ *	};
+ */
+static void encode_sattr3(struct xdr_stream *xdr, const struct iattr *attr,
+		struct user_namespace *userns)
+{
+	u32 nbytes;
+	__be32 *p;
+
+	/*
+	 * In order to make only a single xdr_reserve_space() call,
+	 * pre-compute the total number of bytes to be reserved.
+	 * Six boolean values, one for each set_foo field, are always
+	 * present in the encoded result, so start there.
+	 */
+	nbytes = 6 * 4;
+	if (attr->ia_valid & ATTR_MODE)
+		nbytes += 4;
+	if (attr->ia_valid & ATTR_UID)
+		nbytes += 4;
+	if (attr->ia_valid & ATTR_GID)
+		nbytes += 4;
+	if (attr->ia_valid & ATTR_SIZE)
+		nbytes += 8;
+	if (attr->ia_valid & ATTR_ATIME_SET)
+		nbytes += 8;
+	if (attr->ia_valid & ATTR_MTIME_SET)
+		nbytes += 8;
+	p = xdr_reserve_space(xdr, nbytes);
+
+	if (attr->ia_valid & ATTR_MODE) {
+		*p++ = xdr_one;
+		*p++ = cpu_to_be32(attr->ia_mode & S_IALLUGO);
+	} else
+		*p++ = xdr_zero;
+
+	if (attr->ia_valid & ATTR_UID) {
+		*p++ = xdr_one;
+		*p++ = cpu_to_be32(from_kuid_munged(userns, attr->ia_uid));
+	} else
+		*p++ = xdr_zero;
+
+	if (attr->ia_valid & ATTR_GID) {
+		*p++ = xdr_one;
+		*p++ = cpu_to_be32(from_kgid_munged(userns, attr->ia_gid));
+	} else
+		*p++ = xdr_zero;
+
+	if (attr->ia_valid & ATTR_SIZE) {
+		*p++ = xdr_one;
+		p = xdr_encode_hyper(p, (u64)attr->ia_size);
+	} else
+		*p++ = xdr_zero;
+
+	if (attr->ia_valid & ATTR_ATIME_SET) {
+		*p++ = xdr_two;
+		p = xdr_encode_nfstime3(p, &attr->ia_atime);
+	} else if (attr->ia_valid & ATTR_ATIME) {
+		*p++ = xdr_one;
+	} else
+		*p++ = xdr_zero;
+
+	if (attr->ia_valid & ATTR_MTIME_SET) {
+		*p++ = xdr_two;
+		xdr_encode_nfstime3(p, &attr->ia_mtime);
+	} else if (attr->ia_valid & ATTR_MTIME) {
+		*p = xdr_one;
+	} else
+		*p = xdr_zero;
+}
+
+/*
+ * fattr3
+ *
+ *	struct fattr3 {
+ *		ftype3		type;
+ *		mode3		mode;
+ *		uint32		nlink;
+ *		uid3		uid;
+ *		gid3		gid;
+ *		size3		size;
+ *		size3		used;
+ *		specdata3	rdev;
+ *		uint64		fsid;
+ *		fileid3		fileid;
+ *		nfstime3	atime;
+ *		nfstime3	mtime;
+ *		nfstime3	ctime;
+ *	};
+ */
+static int decode_fattr3(struct xdr_stream *xdr, struct nfs_fattr *fattr,
+		struct user_namespace *userns)
+{
+	umode_t fmode;
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, NFS3_fattr_sz << 2);
+	if (unlikely(!p))
+		return -EIO;
+
+	p = xdr_decode_ftype3(p, &fmode);
+
+	fattr->mode = (be32_to_cpup(p++) & ~S_IFMT) | fmode;
+	fattr->nlink = be32_to_cpup(p++);
+	fattr->uid = make_kuid(userns, be32_to_cpup(p++));
+	if (!uid_valid(fattr->uid))
+		goto out_uid;
+	fattr->gid = make_kgid(userns, be32_to_cpup(p++));
+	if (!gid_valid(fattr->gid))
+		goto out_gid;
+
+	p = xdr_decode_size3(p, &fattr->size);
+	p = xdr_decode_size3(p, &fattr->du.nfs3.used);
+	p = xdr_decode_specdata3(p, &fattr->rdev);
+
+	p = xdr_decode_hyper(p, &fattr->fsid.major);
+	fattr->fsid.minor = 0;
+
+	p = xdr_decode_fileid3(p, &fattr->fileid);
+	p = xdr_decode_nfstime3(p, &fattr->atime);
+	p = xdr_decode_nfstime3(p, &fattr->mtime);
+	xdr_decode_nfstime3(p, &fattr->ctime);
+	fattr->change_attr = nfs_timespec_to_change_attr(&fattr->ctime);
+
+	fattr->valid |= NFS_ATTR_FATTR_V3;
+	return 0;
+out_uid:
+	dprintk("NFS: returned invalid uid\n");
+	return -EINVAL;
+out_gid:
+	dprintk("NFS: returned invalid gid\n");
+	return -EINVAL;
+}
+
+/*
+ * post_op_attr
+ *
+ *	union post_op_attr switch (bool attributes_follow) {
+ *	case TRUE:
+ *		fattr3	attributes;
+ *	case FALSE:
+ *		void;
+ *	};
+ */
+static int decode_post_op_attr(struct xdr_stream *xdr, struct nfs_fattr *fattr,
+		struct user_namespace *userns)
+{
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(!p))
+		return -EIO;
+	if (*p != xdr_zero)
+		return decode_fattr3(xdr, fattr, userns);
+	return 0;
+}
+
+/*
+ * wcc_attr
+ *	struct wcc_attr {
+ *		size3		size;
+ *		nfstime3	mtime;
+ *		nfstime3	ctime;
+ *	};
+ */
+static int decode_wcc_attr(struct xdr_stream *xdr, struct nfs_fattr *fattr)
+{
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, NFS3_wcc_attr_sz << 2);
+	if (unlikely(!p))
+		return -EIO;
+
+	fattr->valid |= NFS_ATTR_FATTR_PRESIZE
+		| NFS_ATTR_FATTR_PRECHANGE
+		| NFS_ATTR_FATTR_PREMTIME
+		| NFS_ATTR_FATTR_PRECTIME;
+
+	p = xdr_decode_size3(p, &fattr->pre_size);
+	p = xdr_decode_nfstime3(p, &fattr->pre_mtime);
+	xdr_decode_nfstime3(p, &fattr->pre_ctime);
+	fattr->pre_change_attr = nfs_timespec_to_change_attr(&fattr->pre_ctime);
+
+	return 0;
+}
+
+/*
+ * pre_op_attr
+ *	union pre_op_attr switch (bool attributes_follow) {
+ *	case TRUE:
+ *		wcc_attr	attributes;
+ *	case FALSE:
+ *		void;
+ *	};
+ *
+ * wcc_data
+ *
+ *	struct wcc_data {
+ *		pre_op_attr	before;
+ *		post_op_attr	after;
+ *	};
+ */
+static int decode_pre_op_attr(struct xdr_stream *xdr, struct nfs_fattr *fattr)
+{
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(!p))
+		return -EIO;
+	if (*p != xdr_zero)
+		return decode_wcc_attr(xdr, fattr);
+	return 0;
+}
+
+static int decode_wcc_data(struct xdr_stream *xdr, struct nfs_fattr *fattr,
+		struct user_namespace *userns)
+{
+	int error;
+
+	error = decode_pre_op_attr(xdr, fattr);
+	if (unlikely(error))
+		goto out;
+	error = decode_post_op_attr(xdr, fattr, userns);
+out:
+	return error;
+}
+
+/*
+ * post_op_fh3
+ *
+ *	union post_op_fh3 switch (bool handle_follows) {
+ *	case TRUE:
+ *		nfs_fh3  handle;
+ *	case FALSE:
+ *		void;
+ *	};
+ */
+static int decode_post_op_fh3(struct xdr_stream *xdr, struct nfs_fh *fh)
+{
+	__be32 *p = xdr_inline_decode(xdr, 4);
+	if (unlikely(!p))
+		return -EIO;
+	if (*p != xdr_zero)
+		return decode_nfs_fh3(xdr, fh);
+	zero_nfs_fh3(fh);
+	return 0;
+}
+
+/*
+ * diropargs3
+ *
+ *	struct diropargs3 {
+ *		nfs_fh3		dir;
+ *		filename3	name;
+ *	};
+ */
+static void encode_diropargs3(struct xdr_stream *xdr, const struct nfs_fh *fh,
+			      const char *name, u32 length)
+{
+	encode_nfs_fh3(xdr, fh);
+	encode_filename3(xdr, name, length);
+}
+
+
+/*
+ * NFSv3 XDR encode functions
+ *
+ * NFSv3 argument types are defined in section 3.3 of RFC 1813:
+ * "NFS Version 3 Protocol Specification".
+ */
+
+/*
+ * 3.3.1  GETATTR3args
+ *
+ *	struct GETATTR3args {
+ *		nfs_fh3  object;
+ *	};
+ */
+static void nfs3_xdr_enc_getattr3args(struct rpc_rqst *req,
+				      struct xdr_stream *xdr,
+				      const void *data)
+{
+	const struct nfs_fh *fh = data;
+
+	encode_nfs_fh3(xdr, fh);
+}
+
+/*
+ * 3.3.2  SETATTR3args
+ *
+ *	union sattrguard3 switch (bool check) {
+ *	case TRUE:
+ *		nfstime3  obj_ctime;
+ *	case FALSE:
+ *		void;
+ *	};
+ *
+ *	struct SETATTR3args {
+ *		nfs_fh3		object;
+ *		sattr3		new_attributes;
+ *		sattrguard3	guard;
+ *	};
+ */
+static void encode_sattrguard3(struct xdr_stream *xdr,
+			       const struct nfs3_sattrargs *args)
+{
+	__be32 *p;
+
+	if (args->guard) {
+		p = xdr_reserve_space(xdr, 4 + 8);
+		*p++ = xdr_one;
+		xdr_encode_nfstime3(p, &args->guardtime);
+	} else {
+		p = xdr_reserve_space(xdr, 4);
+		*p = xdr_zero;
+	}
+}
+
+static void nfs3_xdr_enc_setattr3args(struct rpc_rqst *req,
+				      struct xdr_stream *xdr,
+				      const void *data)
+{
+	const struct nfs3_sattrargs *args = data;
+	encode_nfs_fh3(xdr, args->fh);
+	encode_sattr3(xdr, args->sattr, rpc_rqst_userns(req));
+	encode_sattrguard3(xdr, args);
+}
+
+/*
+ * 3.3.3  LOOKUP3args
+ *
+ *	struct LOOKUP3args {
+ *		diropargs3  what;
+ *	};
+ */
+static void nfs3_xdr_enc_lookup3args(struct rpc_rqst *req,
+				     struct xdr_stream *xdr,
+				     const void *data)
+{
+	const struct nfs3_diropargs *args = data;
+
+	encode_diropargs3(xdr, args->fh, args->name, args->len);
+}
+
+/*
+ * 3.3.4  ACCESS3args
+ *
+ *	struct ACCESS3args {
+ *		nfs_fh3		object;
+ *		uint32		access;
+ *	};
+ */
+static void encode_access3args(struct xdr_stream *xdr,
+			       const struct nfs3_accessargs *args)
+{
+	encode_nfs_fh3(xdr, args->fh);
+	encode_uint32(xdr, args->access);
+}
+
+static void nfs3_xdr_enc_access3args(struct rpc_rqst *req,
+				     struct xdr_stream *xdr,
+				     const void *data)
+{
+	const struct nfs3_accessargs *args = data;
+
+	encode_access3args(xdr, args);
+}
+
+/*
+ * 3.3.5  READLINK3args
+ *
+ *	struct READLINK3args {
+ *		nfs_fh3	symlink;
+ *	};
+ */
+static void nfs3_xdr_enc_readlink3args(struct rpc_rqst *req,
+				       struct xdr_stream *xdr,
+				       const void *data)
+{
+	const struct nfs3_readlinkargs *args = data;
+
+	encode_nfs_fh3(xdr, args->fh);
+	rpc_prepare_reply_pages(req, args->pages, args->pgbase,
+				args->pglen, NFS3_readlinkres_sz);
+}
+
+/*
+ * 3.3.6  READ3args
+ *
+ *	struct READ3args {
+ *		nfs_fh3		file;
+ *		offset3		offset;
+ *		count3		count;
+ *	};
+ */
+static void encode_read3args(struct xdr_stream *xdr,
+			     const struct nfs_pgio_args *args)
+{
+	__be32 *p;
+
+	encode_nfs_fh3(xdr, args->fh);
+
+	p = xdr_reserve_space(xdr, 8 + 4);
+	p = xdr_encode_hyper(p, args->offset);
+	*p = cpu_to_be32(args->count);
+}
+
+static void nfs3_xdr_enc_read3args(struct rpc_rqst *req,
+				   struct xdr_stream *xdr,
+				   const void *data)
+{
+	const struct nfs_pgio_args *args = data;
+	unsigned int replen = args->replen ? args->replen : NFS3_readres_sz;
+
+	encode_read3args(xdr, args);
+	rpc_prepare_reply_pages(req, args->pages, args->pgbase,
+				args->count, replen);
+	req->rq_rcv_buf.flags |= XDRBUF_READ;
+}
+
+/*
+ * 3.3.7  WRITE3args
+ *
+ *	enum stable_how {
+ *		UNSTABLE  = 0,
+ *		DATA_SYNC = 1,
+ *		FILE_SYNC = 2
+ *	};
+ *
+ *	struct WRITE3args {
+ *		nfs_fh3		file;
+ *		offset3		offset;
+ *		count3		count;
+ *		stable_how	stable;
+ *		opaque		data<>;
+ *	};
+ */
+static void encode_write3args(struct xdr_stream *xdr,
+			      const struct nfs_pgio_args *args)
+{
+	__be32 *p;
+
+	encode_nfs_fh3(xdr, args->fh);
+
+	p = xdr_reserve_space(xdr, 8 + 4 + 4 + 4);
+	p = xdr_encode_hyper(p, args->offset);
+	*p++ = cpu_to_be32(args->count);
+	*p++ = cpu_to_be32(args->stable);
+	*p = cpu_to_be32(args->count);
+	xdr_write_pages(xdr, args->pages, args->pgbase, args->count);
+}
+
+static void nfs3_xdr_enc_write3args(struct rpc_rqst *req,
+				    struct xdr_stream *xdr,
+				    const void *data)
+{
+	const struct nfs_pgio_args *args = data;
+
+	encode_write3args(xdr, args);
+	xdr->buf->flags |= XDRBUF_WRITE;
+}
+
+/*
+ * 3.3.8  CREATE3args
+ *
+ *	enum createmode3 {
+ *		UNCHECKED = 0,
+ *		GUARDED   = 1,
+ *		EXCLUSIVE = 2
+ *	};
+ *
+ *	union createhow3 switch (createmode3 mode) {
+ *	case UNCHECKED:
+ *	case GUARDED:
+ *		sattr3       obj_attributes;
+ *	case EXCLUSIVE:
+ *		createverf3  verf;
+ *	};
+ *
+ *	struct CREATE3args {
+ *		diropargs3	where;
+ *		createhow3	how;
+ *	};
+ */
+static void encode_createhow3(struct xdr_stream *xdr,
+			      const struct nfs3_createargs *args,
+			      struct user_namespace *userns)
+{
+	encode_uint32(xdr, args->createmode);
+	switch (args->createmode) {
+	case NFS3_CREATE_UNCHECKED:
+	case NFS3_CREATE_GUARDED:
+		encode_sattr3(xdr, args->sattr, userns);
+		break;
+	case NFS3_CREATE_EXCLUSIVE:
+		encode_createverf3(xdr, args->verifier);
+		break;
+	default:
+		BUG();
+	}
+}
+
+static void nfs3_xdr_enc_create3args(struct rpc_rqst *req,
+				     struct xdr_stream *xdr,
+				     const void *data)
+{
+	const struct nfs3_createargs *args = data;
+
+	encode_diropargs3(xdr, args->fh, args->name, args->len);
+	encode_createhow3(xdr, args, rpc_rqst_userns(req));
+}
+
+/*
+ * 3.3.9  MKDIR3args
+ *
+ *	struct MKDIR3args {
+ *		diropargs3	where;
+ *		sattr3		attributes;
+ *	};
+ */
+static void nfs3_xdr_enc_mkdir3args(struct rpc_rqst *req,
+				    struct xdr_stream *xdr,
+				    const void *data)
+{
+	const struct nfs3_mkdirargs *args = data;
+
+	encode_diropargs3(xdr, args->fh, args->name, args->len);
+	encode_sattr3(xdr, args->sattr, rpc_rqst_userns(req));
+}
+
+/*
+ * 3.3.10  SYMLINK3args
+ *
+ *	struct symlinkdata3 {
+ *		sattr3		symlink_attributes;
+ *		nfspath3	symlink_data;
+ *	};
+ *
+ *	struct SYMLINK3args {
+ *		diropargs3	where;
+ *		symlinkdata3	symlink;
+ *	};
+ */
+static void encode_symlinkdata3(struct xdr_stream *xdr,
+				const void *data,
+				struct user_namespace *userns)
+{
+	const struct nfs3_symlinkargs *args = data;
+
+	encode_sattr3(xdr, args->sattr, userns);
+	encode_nfspath3(xdr, args->pages, args->pathlen);
+}
+
+static void nfs3_xdr_enc_symlink3args(struct rpc_rqst *req,
+				      struct xdr_stream *xdr,
+				      const void *data)
+{
+	const struct nfs3_symlinkargs *args = data;
+
+	encode_diropargs3(xdr, args->fromfh, args->fromname, args->fromlen);
+	encode_symlinkdata3(xdr, args, rpc_rqst_userns(req));
+	xdr->buf->flags |= XDRBUF_WRITE;
+}
+
+/*
+ * 3.3.11  MKNOD3args
+ *
+ *	struct devicedata3 {
+ *		sattr3		dev_attributes;
+ *		specdata3	spec;
+ *	};
+ *
+ *	union mknoddata3 switch (ftype3 type) {
+ *	case NF3CHR:
+ *	case NF3BLK:
+ *		devicedata3	device;
+ *	case NF3SOCK:
+ *	case NF3FIFO:
+ *		sattr3		pipe_attributes;
+ *	default:
+ *		void;
+ *	};
+ *
+ *	struct MKNOD3args {
+ *		diropargs3	where;
+ *		mknoddata3	what;
+ *	};
+ */
+static void encode_devicedata3(struct xdr_stream *xdr,
+			       const struct nfs3_mknodargs *args,
+			       struct user_namespace *userns)
+{
+	encode_sattr3(xdr, args->sattr, userns);
+	encode_specdata3(xdr, args->rdev);
+}
+
+static void encode_mknoddata3(struct xdr_stream *xdr,
+			      const struct nfs3_mknodargs *args,
+			      struct user_namespace *userns)
+{
+	encode_ftype3(xdr, args->type);
+	switch (args->type) {
+	case NF3CHR:
+	case NF3BLK:
+		encode_devicedata3(xdr, args, userns);
+		break;
+	case NF3SOCK:
+	case NF3FIFO:
+		encode_sattr3(xdr, args->sattr, userns);
+		break;
+	case NF3REG:
+	case NF3DIR:
+		break;
+	default:
+		BUG();
+	}
+}
+
+static void nfs3_xdr_enc_mknod3args(struct rpc_rqst *req,
+				    struct xdr_stream *xdr,
+				    const void *data)
+{
+	const struct nfs3_mknodargs *args = data;
+
+	encode_diropargs3(xdr, args->fh, args->name, args->len);
+	encode_mknoddata3(xdr, args, rpc_rqst_userns(req));
+}
+
+/*
+ * 3.3.12  REMOVE3args
+ *
+ *	struct REMOVE3args {
+ *		diropargs3  object;
+ *	};
+ */
+static void nfs3_xdr_enc_remove3args(struct rpc_rqst *req,
+				     struct xdr_stream *xdr,
+				     const void *data)
+{
+	const struct nfs_removeargs *args = data;
+
+	encode_diropargs3(xdr, args->fh, args->name.name, args->name.len);
+}
+
+/*
+ * 3.3.14  RENAME3args
+ *
+ *	struct RENAME3args {
+ *		diropargs3	from;
+ *		diropargs3	to;
+ *	};
+ */
+static void nfs3_xdr_enc_rename3args(struct rpc_rqst *req,
+				     struct xdr_stream *xdr,
+				     const void *data)
+{
+	const struct nfs_renameargs *args = data;
+	const struct qstr *old = args->old_name;
+	const struct qstr *new = args->new_name;
+
+	encode_diropargs3(xdr, args->old_dir, old->name, old->len);
+	encode_diropargs3(xdr, args->new_dir, new->name, new->len);
+}
+
+/*
+ * 3.3.15  LINK3args
+ *
+ *	struct LINK3args {
+ *		nfs_fh3		file;
+ *		diropargs3	link;
+ *	};
+ */
+static void nfs3_xdr_enc_link3args(struct rpc_rqst *req,
+				   struct xdr_stream *xdr,
+				   const void *data)
+{
+	const struct nfs3_linkargs *args = data;
+
+	encode_nfs_fh3(xdr, args->fromfh);
+	encode_diropargs3(xdr, args->tofh, args->toname, args->tolen);
+}
+
+/*
+ * 3.3.16  READDIR3args
+ *
+ *	struct READDIR3args {
+ *		nfs_fh3		dir;
+ *		cookie3		cookie;
+ *		cookieverf3	cookieverf;
+ *		count3		count;
+ *	};
+ */
+static void encode_readdir3args(struct xdr_stream *xdr,
+				const struct nfs3_readdirargs *args)
+{
+	__be32 *p;
+
+	encode_nfs_fh3(xdr, args->fh);
+
+	p = xdr_reserve_space(xdr, 8 + NFS3_COOKIEVERFSIZE + 4);
+	p = xdr_encode_cookie3(p, args->cookie);
+	p = xdr_encode_cookieverf3(p, args->verf);
+	*p = cpu_to_be32(args->count);
+}
+
+static void nfs3_xdr_enc_readdir3args(struct rpc_rqst *req,
+				      struct xdr_stream *xdr,
+				      const void *data)
+{
+	const struct nfs3_readdirargs *args = data;
+
+	encode_readdir3args(xdr, args);
+	rpc_prepare_reply_pages(req, args->pages, 0,
+				args->count, NFS3_readdirres_sz);
+}
+
+/*
+ * 3.3.17  READDIRPLUS3args
+ *
+ *	struct READDIRPLUS3args {
+ *		nfs_fh3		dir;
+ *		cookie3		cookie;
+ *		cookieverf3	cookieverf;
+ *		count3		dircount;
+ *		count3		maxcount;
+ *	};
+ */
+static void encode_readdirplus3args(struct xdr_stream *xdr,
+				    const struct nfs3_readdirargs *args)
+{
+	__be32 *p;
+
+	encode_nfs_fh3(xdr, args->fh);
+
+	p = xdr_reserve_space(xdr, 8 + NFS3_COOKIEVERFSIZE + 4 + 4);
+	p = xdr_encode_cookie3(p, args->cookie);
+	p = xdr_encode_cookieverf3(p, args->verf);
+
+	/*
+	 * readdirplus: need dircount + buffer size.
+	 * We just make sure we make dircount big enough
+	 */
+	*p++ = cpu_to_be32(args->count >> 3);
+
+	*p = cpu_to_be32(args->count);
+}
+
+static void nfs3_xdr_enc_readdirplus3args(struct rpc_rqst *req,
+					  struct xdr_stream *xdr,
+					  const void *data)
+{
+	const struct nfs3_readdirargs *args = data;
+
+	encode_readdirplus3args(xdr, args);
+	rpc_prepare_reply_pages(req, args->pages, 0,
+				args->count, NFS3_readdirres_sz);
+}
+
+/*
+ * 3.3.21  COMMIT3args
+ *
+ *	struct COMMIT3args {
+ *		nfs_fh3		file;
+ *		offset3		offset;
+ *		count3		count;
+ *	};
+ */
+static void encode_commit3args(struct xdr_stream *xdr,
+			       const struct nfs_commitargs *args)
+{
+	__be32 *p;
+
+	encode_nfs_fh3(xdr, args->fh);
+
+	p = xdr_reserve_space(xdr, 8 + 4);
+	p = xdr_encode_hyper(p, args->offset);
+	*p = cpu_to_be32(args->count);
+}
+
+static void nfs3_xdr_enc_commit3args(struct rpc_rqst *req,
+				     struct xdr_stream *xdr,
+				     const void *data)
+{
+	const struct nfs_commitargs *args = data;
+
+	encode_commit3args(xdr, args);
+}
+
+#ifdef CONFIG_NFS_V3_ACL
+
+static void nfs3_xdr_enc_getacl3args(struct rpc_rqst *req,
+				     struct xdr_stream *xdr,
+				     const void *data)
+{
+	const struct nfs3_getaclargs *args = data;
+
+	encode_nfs_fh3(xdr, args->fh);
+	encode_uint32(xdr, args->mask);
+	if (args->mask & (NFS_ACL | NFS_DFACL)) {
+		rpc_prepare_reply_pages(req, args->pages, 0,
+					NFSACL_MAXPAGES << PAGE_SHIFT,
+					ACL3_getaclres_sz);
+		req->rq_rcv_buf.flags |= XDRBUF_SPARSE_PAGES;
+	}
+}
+
+static void nfs3_xdr_enc_setacl3args(struct rpc_rqst *req,
+				     struct xdr_stream *xdr,
+				     const void *data)
+{
+	const struct nfs3_setaclargs *args = data;
+	unsigned int base;
+	int error;
+
+	encode_nfs_fh3(xdr, NFS_FH(args->inode));
+	encode_uint32(xdr, args->mask);
+
+	base = req->rq_slen;
+	if (args->npages != 0)
+		xdr_write_pages(xdr, args->pages, 0, args->len);
+	else
+		xdr_reserve_space(xdr, args->len);
+
+	error = nfsacl_encode(xdr->buf, base, args->inode,
+			    (args->mask & NFS_ACL) ?
+			    args->acl_access : NULL, 1, 0);
+	/* FIXME: this is just broken */
+	BUG_ON(error < 0);
+	error = nfsacl_encode(xdr->buf, base + error, args->inode,
+			    (args->mask & NFS_DFACL) ?
+			    args->acl_default : NULL, 1,
+			    NFS_ACL_DEFAULT);
+	BUG_ON(error < 0);
+}
+
+#endif  /* CONFIG_NFS_V3_ACL */
+
+/*
+ * NFSv3 XDR decode functions
+ *
+ * NFSv3 result types are defined in section 3.3 of RFC 1813:
+ * "NFS Version 3 Protocol Specification".
+ */
+
+/*
+ * 3.3.1  GETATTR3res
+ *
+ *	struct GETATTR3resok {
+ *		fattr3		obj_attributes;
+ *	};
+ *
+ *	union GETATTR3res switch (nfsstat3 status) {
+ *	case NFS3_OK:
+ *		GETATTR3resok  resok;
+ *	default:
+ *		void;
+ *	};
+ */
+static int nfs3_xdr_dec_getattr3res(struct rpc_rqst *req,
+				    struct xdr_stream *xdr,
+				    void *result)
+{
+	enum nfs_stat status;
+	int error;
+
+	error = decode_nfsstat3(xdr, &status);
+	if (unlikely(error))
+		goto out;
+	if (status != NFS3_OK)
+		goto out_default;
+	error = decode_fattr3(xdr, result, rpc_rqst_userns(req));
+out:
+	return error;
+out_default:
+	return nfs3_stat_to_errno(status);
+}
+
+/*
+ * 3.3.2  SETATTR3res
+ *
+ *	struct SETATTR3resok {
+ *		wcc_data  obj_wcc;
+ *	};
+ *
+ *	struct SETATTR3resfail {
+ *		wcc_data  obj_wcc;
+ *	};
+ *
+ *	union SETATTR3res switch (nfsstat3 status) {
+ *	case NFS3_OK:
+ *		SETATTR3resok   resok;
+ *	default:
+ *		SETATTR3resfail resfail;
+ *	};
+ */
+static int nfs3_xdr_dec_setattr3res(struct rpc_rqst *req,
+				    struct xdr_stream *xdr,
+				    void *result)
+{
+	enum nfs_stat status;
+	int error;
+
+	error = decode_nfsstat3(xdr, &status);
+	if (unlikely(error))
+		goto out;
+	error = decode_wcc_data(xdr, result, rpc_rqst_userns(req));
+	if (unlikely(error))
+		goto out;
+	if (status != NFS3_OK)
+		goto out_status;
+out:
+	return error;
+out_status:
+	return nfs3_stat_to_errno(status);
+}
+
+/*
+ * 3.3.3  LOOKUP3res
+ *
+ *	struct LOOKUP3resok {
+ *		nfs_fh3		object;
+ *		post_op_attr	obj_attributes;
+ *		post_op_attr	dir_attributes;
+ *	};
+ *
+ *	struct LOOKUP3resfail {
+ *		post_op_attr	dir_attributes;
+ *	};
+ *
+ *	union LOOKUP3res switch (nfsstat3 status) {
+ *	case NFS3_OK:
+ *		LOOKUP3resok	resok;
+ *	default:
+ *		LOOKUP3resfail	resfail;
+ *	};
+ */
+static int nfs3_xdr_dec_lookup3res(struct rpc_rqst *req,
+				   struct xdr_stream *xdr,
+				   void *data)
+{
+	struct user_namespace *userns = rpc_rqst_userns(req);
+	struct nfs3_diropres *result = data;
+	enum nfs_stat status;
+	int error;
+
+	error = decode_nfsstat3(xdr, &status);
+	if (unlikely(error))
+		goto out;
+	if (status != NFS3_OK)
+		goto out_default;
+	error = decode_nfs_fh3(xdr, result->fh);
+	if (unlikely(error))
+		goto out;
+	error = decode_post_op_attr(xdr, result->fattr, userns);
+	if (unlikely(error))
+		goto out;
+	error = decode_post_op_attr(xdr, result->dir_attr, userns);
+out:
+	return error;
+out_default:
+	error = decode_post_op_attr(xdr, result->dir_attr, userns);
+	if (unlikely(error))
+		goto out;
+	return nfs3_stat_to_errno(status);
+}
+
+/*
+ * 3.3.4  ACCESS3res
+ *
+ *	struct ACCESS3resok {
+ *		post_op_attr	obj_attributes;
+ *		uint32		access;
+ *	};
+ *
+ *	struct ACCESS3resfail {
+ *		post_op_attr	obj_attributes;
+ *	};
+ *
+ *	union ACCESS3res switch (nfsstat3 status) {
+ *	case NFS3_OK:
+ *		ACCESS3resok	resok;
+ *	default:
+ *		ACCESS3resfail	resfail;
+ *	};
+ */
+static int nfs3_xdr_dec_access3res(struct rpc_rqst *req,
+				   struct xdr_stream *xdr,
+				   void *data)
+{
+	struct nfs3_accessres *result = data;
+	enum nfs_stat status;
+	int error;
+
+	error = decode_nfsstat3(xdr, &status);
+	if (unlikely(error))
+		goto out;
+	error = decode_post_op_attr(xdr, result->fattr, rpc_rqst_userns(req));
+	if (unlikely(error))
+		goto out;
+	if (status != NFS3_OK)
+		goto out_default;
+	error = decode_uint32(xdr, &result->access);
+out:
+	return error;
+out_default:
+	return nfs3_stat_to_errno(status);
+}
+
+/*
+ * 3.3.5  READLINK3res
+ *
+ *	struct READLINK3resok {
+ *		post_op_attr	symlink_attributes;
+ *		nfspath3	data;
+ *	};
+ *
+ *	struct READLINK3resfail {
+ *		post_op_attr	symlink_attributes;
+ *	};
+ *
+ *	union READLINK3res switch (nfsstat3 status) {
+ *	case NFS3_OK:
+ *		READLINK3resok	resok;
+ *	default:
+ *		READLINK3resfail resfail;
+ *	};
+ */
+static int nfs3_xdr_dec_readlink3res(struct rpc_rqst *req,
+				     struct xdr_stream *xdr,
+				     void *result)
+{
+	enum nfs_stat status;
+	int error;
+
+	error = decode_nfsstat3(xdr, &status);
+	if (unlikely(error))
+		goto out;
+	error = decode_post_op_attr(xdr, result, rpc_rqst_userns(req));
+	if (unlikely(error))
+		goto out;
+	if (status != NFS3_OK)
+		goto out_default;
+	error = decode_nfspath3(xdr);
+out:
+	return error;
+out_default:
+	return nfs3_stat_to_errno(status);
+}
+
+/*
+ * 3.3.6  READ3res
+ *
+ *	struct READ3resok {
+ *		post_op_attr	file_attributes;
+ *		count3		count;
+ *		bool		eof;
+ *		opaque		data<>;
+ *	};
+ *
+ *	struct READ3resfail {
+ *		post_op_attr	file_attributes;
+ *	};
+ *
+ *	union READ3res switch (nfsstat3 status) {
+ *	case NFS3_OK:
+ *		READ3resok	resok;
+ *	default:
+ *		READ3resfail	resfail;
+ *	};
+ */
+static int decode_read3resok(struct xdr_stream *xdr,
+			     struct nfs_pgio_res *result)
+{
+	u32 eof, count, ocount, recvd;
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, 4 + 4 + 4);
+	if (unlikely(!p))
+		return -EIO;
+	count = be32_to_cpup(p++);
+	eof = be32_to_cpup(p++);
+	ocount = be32_to_cpup(p++);
+	if (unlikely(ocount != count))
+		goto out_mismatch;
+	recvd = xdr_read_pages(xdr, count);
+	if (unlikely(count > recvd))
+		goto out_cheating;
+out:
+	result->eof = eof;
+	result->count = count;
+	return count;
+out_mismatch:
+	dprintk("NFS: READ count doesn't match length of opaque: "
+		"count %u != ocount %u\n", count, ocount);
+	return -EIO;
+out_cheating:
+	dprintk("NFS: server cheating in read result: "
+		"count %u > recvd %u\n", count, recvd);
+	count = recvd;
+	eof = 0;
+	goto out;
+}
+
+static int nfs3_xdr_dec_read3res(struct rpc_rqst *req, struct xdr_stream *xdr,
+				 void *data)
+{
+	struct nfs_pgio_res *result = data;
+	unsigned int pos;
+	enum nfs_stat status;
+	int error;
+
+	pos = xdr_stream_pos(xdr);
+	error = decode_nfsstat3(xdr, &status);
+	if (unlikely(error))
+		goto out;
+	error = decode_post_op_attr(xdr, result->fattr, rpc_rqst_userns(req));
+	if (unlikely(error))
+		goto out;
+	result->op_status = status;
+	if (status != NFS3_OK)
+		goto out_status;
+	result->replen = 4 + ((xdr_stream_pos(xdr) - pos) >> 2);
+	error = decode_read3resok(xdr, result);
+out:
+	return error;
+out_status:
+	return nfs3_stat_to_errno(status);
+}
+
+/*
+ * 3.3.7  WRITE3res
+ *
+ *	enum stable_how {
+ *		UNSTABLE  = 0,
+ *		DATA_SYNC = 1,
+ *		FILE_SYNC = 2
+ *	};
+ *
+ *	struct WRITE3resok {
+ *		wcc_data	file_wcc;
+ *		count3		count;
+ *		stable_how	committed;
+ *		writeverf3	verf;
+ *	};
+ *
+ *	struct WRITE3resfail {
+ *		wcc_data	file_wcc;
+ *	};
+ *
+ *	union WRITE3res switch (nfsstat3 status) {
+ *	case NFS3_OK:
+ *		WRITE3resok	resok;
+ *	default:
+ *		WRITE3resfail	resfail;
+ *	};
+ */
+static int decode_write3resok(struct xdr_stream *xdr,
+			      struct nfs_pgio_res *result)
+{
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, 4 + 4);
+	if (unlikely(!p))
+		return -EIO;
+	result->count = be32_to_cpup(p++);
+	result->verf->committed = be32_to_cpup(p++);
+	if (unlikely(result->verf->committed > NFS_FILE_SYNC))
+		goto out_badvalue;
+	if (decode_writeverf3(xdr, &result->verf->verifier))
+		return -EIO;
+	return result->count;
+out_badvalue:
+	dprintk("NFS: bad stable_how value: %u\n", result->verf->committed);
+	return -EIO;
+}
+
+static int nfs3_xdr_dec_write3res(struct rpc_rqst *req, struct xdr_stream *xdr,
+				  void *data)
+{
+	struct nfs_pgio_res *result = data;
+	enum nfs_stat status;
+	int error;
+
+	error = decode_nfsstat3(xdr, &status);
+	if (unlikely(error))
+		goto out;
+	error = decode_wcc_data(xdr, result->fattr, rpc_rqst_userns(req));
+	if (unlikely(error))
+		goto out;
+	result->op_status = status;
+	if (status != NFS3_OK)
+		goto out_status;
+	error = decode_write3resok(xdr, result);
+out:
+	return error;
+out_status:
+	return nfs3_stat_to_errno(status);
+}
+
+/*
+ * 3.3.8  CREATE3res
+ *
+ *	struct CREATE3resok {
+ *		post_op_fh3	obj;
+ *		post_op_attr	obj_attributes;
+ *		wcc_data	dir_wcc;
+ *	};
+ *
+ *	struct CREATE3resfail {
+ *		wcc_data	dir_wcc;
+ *	};
+ *
+ *	union CREATE3res switch (nfsstat3 status) {
+ *	case NFS3_OK:
+ *		CREATE3resok	resok;
+ *	default:
+ *		CREATE3resfail	resfail;
+ *	};
+ */
+static int decode_create3resok(struct xdr_stream *xdr,
+			       struct nfs3_diropres *result,
+			       struct user_namespace *userns)
+{
+	int error;
+
+	error = decode_post_op_fh3(xdr, result->fh);
+	if (unlikely(error))
+		goto out;
+	error = decode_post_op_attr(xdr, result->fattr, userns);
+	if (unlikely(error))
+		goto out;
+	/* The server isn't required to return a file handle.
+	 * If it didn't, force the client to perform a LOOKUP
+	 * to determine the correct file handle and attribute
+	 * values for the new object. */
+	if (result->fh->size == 0)
+		result->fattr->valid = 0;
+	error = decode_wcc_data(xdr, result->dir_attr, userns);
+out:
+	return error;
+}
+
+static int nfs3_xdr_dec_create3res(struct rpc_rqst *req,
+				   struct xdr_stream *xdr,
+				   void *data)
+{
+	struct user_namespace *userns = rpc_rqst_userns(req);
+	struct nfs3_diropres *result = data;
+	enum nfs_stat status;
+	int error;
+
+	error = decode_nfsstat3(xdr, &status);
+	if (unlikely(error))
+		goto out;
+	if (status != NFS3_OK)
+		goto out_default;
+	error = decode_create3resok(xdr, result, userns);
+out:
+	return error;
+out_default:
+	error = decode_wcc_data(xdr, result->dir_attr, userns);
+	if (unlikely(error))
+		goto out;
+	return nfs3_stat_to_errno(status);
+}
+
+/*
+ * 3.3.12  REMOVE3res
+ *
+ *	struct REMOVE3resok {
+ *		wcc_data    dir_wcc;
+ *	};
+ *
+ *	struct REMOVE3resfail {
+ *		wcc_data    dir_wcc;
+ *	};
+ *
+ *	union REMOVE3res switch (nfsstat3 status) {
+ *	case NFS3_OK:
+ *		REMOVE3resok   resok;
+ *	default:
+ *		REMOVE3resfail resfail;
+ *	};
+ */
+static int nfs3_xdr_dec_remove3res(struct rpc_rqst *req,
+				   struct xdr_stream *xdr,
+				   void *data)
+{
+	struct nfs_removeres *result = data;
+	enum nfs_stat status;
+	int error;
+
+	error = decode_nfsstat3(xdr, &status);
+	if (unlikely(error))
+		goto out;
+	error = decode_wcc_data(xdr, result->dir_attr, rpc_rqst_userns(req));
+	if (unlikely(error))
+		goto out;
+	if (status != NFS3_OK)
+		goto out_status;
+out:
+	return error;
+out_status:
+	return nfs3_stat_to_errno(status);
+}
+
+/*
+ * 3.3.14  RENAME3res
+ *
+ *	struct RENAME3resok {
+ *		wcc_data	fromdir_wcc;
+ *		wcc_data	todir_wcc;
+ *	};
+ *
+ *	struct RENAME3resfail {
+ *		wcc_data	fromdir_wcc;
+ *		wcc_data	todir_wcc;
+ *	};
+ *
+ *	union RENAME3res switch (nfsstat3 status) {
+ *	case NFS3_OK:
+ *		RENAME3resok   resok;
+ *	default:
+ *		RENAME3resfail resfail;
+ *	};
+ */
+static int nfs3_xdr_dec_rename3res(struct rpc_rqst *req,
+				   struct xdr_stream *xdr,
+				   void *data)
+{
+	struct user_namespace *userns = rpc_rqst_userns(req);
+	struct nfs_renameres *result = data;
+	enum nfs_stat status;
+	int error;
+
+	error = decode_nfsstat3(xdr, &status);
+	if (unlikely(error))
+		goto out;
+	error = decode_wcc_data(xdr, result->old_fattr, userns);
+	if (unlikely(error))
+		goto out;
+	error = decode_wcc_data(xdr, result->new_fattr, userns);
+	if (unlikely(error))
+		goto out;
+	if (status != NFS3_OK)
+		goto out_status;
+out:
+	return error;
+out_status:
+	return nfs3_stat_to_errno(status);
+}
+
+/*
+ * 3.3.15  LINK3res
+ *
+ *	struct LINK3resok {
+ *		post_op_attr	file_attributes;
+ *		wcc_data	linkdir_wcc;
+ *	};
+ *
+ *	struct LINK3resfail {
+ *		post_op_attr	file_attributes;
+ *		wcc_data	linkdir_wcc;
+ *	};
+ *
+ *	union LINK3res switch (nfsstat3 status) {
+ *	case NFS3_OK:
+ *		LINK3resok	resok;
+ *	default:
+ *		LINK3resfail	resfail;
+ *	};
+ */
+static int nfs3_xdr_dec_link3res(struct rpc_rqst *req, struct xdr_stream *xdr,
+				 void *data)
+{
+	struct user_namespace *userns = rpc_rqst_userns(req);
+	struct nfs3_linkres *result = data;
+	enum nfs_stat status;
+	int error;
+
+	error = decode_nfsstat3(xdr, &status);
+	if (unlikely(error))
+		goto out;
+	error = decode_post_op_attr(xdr, result->fattr, userns);
+	if (unlikely(error))
+		goto out;
+	error = decode_wcc_data(xdr, result->dir_attr, userns);
+	if (unlikely(error))
+		goto out;
+	if (status != NFS3_OK)
+		goto out_status;
+out:
+	return error;
+out_status:
+	return nfs3_stat_to_errno(status);
+}
+
+/**
+ * nfs3_decode_dirent - Decode a single NFSv3 directory entry stored in
+ *			the local page cache
+ * @xdr: XDR stream where entry resides
+ * @entry: buffer to fill in with entry data
+ * @plus: boolean indicating whether this should be a readdirplus entry
+ *
+ * Returns zero if successful, otherwise a negative errno value is
+ * returned.
+ *
+ * This function is not invoked during READDIR reply decoding, but
+ * rather whenever an application invokes the getdents(2) system call
+ * on a directory already in our cache.
+ *
+ * 3.3.16  entry3
+ *
+ *	struct entry3 {
+ *		fileid3		fileid;
+ *		filename3	name;
+ *		cookie3		cookie;
+ *		fhandle3	filehandle;
+ *		post_op_attr3	attributes;
+ *		entry3		*nextentry;
+ *	};
+ *
+ * 3.3.17  entryplus3
+ *	struct entryplus3 {
+ *		fileid3		fileid;
+ *		filename3	name;
+ *		cookie3		cookie;
+ *		post_op_attr	name_attributes;
+ *		post_op_fh3	name_handle;
+ *		entryplus3	*nextentry;
+ *	};
+ */
+int nfs3_decode_dirent(struct xdr_stream *xdr, struct nfs_entry *entry,
+		       bool plus)
+{
+	struct user_namespace *userns = rpc_userns(entry->server->client);
+	__be32 *p;
+	int error;
+	u64 new_cookie;
+
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(!p))
+		return -EAGAIN;
+	if (*p == xdr_zero) {
+		p = xdr_inline_decode(xdr, 4);
+		if (unlikely(!p))
+			return -EAGAIN;
+		if (*p == xdr_zero)
+			return -EAGAIN;
+		entry->eof = 1;
+		return -EBADCOOKIE;
+	}
+
+	error = decode_fileid3(xdr, &entry->ino);
+	if (unlikely(error))
+		return -EAGAIN;
+
+	error = decode_inline_filename3(xdr, &entry->name, &entry->len);
+	if (unlikely(error))
+		return error == -ENAMETOOLONG ? -ENAMETOOLONG : -EAGAIN;
+
+	error = decode_cookie3(xdr, &new_cookie);
+	if (unlikely(error))
+		return -EAGAIN;
+
+	entry->d_type = DT_UNKNOWN;
+
+	if (plus) {
+		entry->fattr->valid = 0;
+		error = decode_post_op_attr(xdr, entry->fattr, userns);
+		if (unlikely(error))
+			return -EAGAIN;
+		if (entry->fattr->valid & NFS_ATTR_FATTR_V3)
+			entry->d_type = nfs_umode_to_dtype(entry->fattr->mode);
+
+		if (entry->fattr->fileid != entry->ino) {
+			entry->fattr->mounted_on_fileid = entry->ino;
+			entry->fattr->valid |= NFS_ATTR_FATTR_MOUNTED_ON_FILEID;
+		}
+
+		/* In fact, a post_op_fh3: */
+		p = xdr_inline_decode(xdr, 4);
+		if (unlikely(!p))
+			return -EAGAIN;
+		if (*p != xdr_zero) {
+			error = decode_nfs_fh3(xdr, entry->fh);
+			if (unlikely(error))
+				return -EAGAIN;
+		} else
+			zero_nfs_fh3(entry->fh);
+	}
+
+	entry->prev_cookie = entry->cookie;
+	entry->cookie = new_cookie;
+
+	return 0;
+}
+
+/*
+ * 3.3.16  READDIR3res
+ *
+ *	struct dirlist3 {
+ *		entry3		*entries;
+ *		bool		eof;
+ *	};
+ *
+ *	struct READDIR3resok {
+ *		post_op_attr	dir_attributes;
+ *		cookieverf3	cookieverf;
+ *		dirlist3	reply;
+ *	};
+ *
+ *	struct READDIR3resfail {
+ *		post_op_attr	dir_attributes;
+ *	};
+ *
+ *	union READDIR3res switch (nfsstat3 status) {
+ *	case NFS3_OK:
+ *		READDIR3resok	resok;
+ *	default:
+ *		READDIR3resfail	resfail;
+ *	};
+ *
+ * Read the directory contents into the page cache, but otherwise
+ * don't touch them.  The actual decoding is done by nfs3_decode_entry()
+ * during subsequent nfs_readdir() calls.
+ */
+static int decode_dirlist3(struct xdr_stream *xdr)
+{
+	return xdr_read_pages(xdr, xdr->buf->page_len);
+}
+
+static int decode_readdir3resok(struct xdr_stream *xdr,
+				struct nfs3_readdirres *result,
+				struct user_namespace *userns)
+{
+	int error;
+
+	error = decode_post_op_attr(xdr, result->dir_attr, userns);
+	if (unlikely(error))
+		goto out;
+	/* XXX: do we need to check if result->verf != NULL ? */
+	error = decode_cookieverf3(xdr, result->verf);
+	if (unlikely(error))
+		goto out;
+	error = decode_dirlist3(xdr);
+out:
+	return error;
+}
+
+static int nfs3_xdr_dec_readdir3res(struct rpc_rqst *req,
+				    struct xdr_stream *xdr,
+				    void *data)
+{
+	struct nfs3_readdirres *result = data;
+	enum nfs_stat status;
+	int error;
+
+	error = decode_nfsstat3(xdr, &status);
+	if (unlikely(error))
+		goto out;
+	if (status != NFS3_OK)
+		goto out_default;
+	error = decode_readdir3resok(xdr, result, rpc_rqst_userns(req));
+out:
+	return error;
+out_default:
+	error = decode_post_op_attr(xdr, result->dir_attr, rpc_rqst_userns(req));
+	if (unlikely(error))
+		goto out;
+	return nfs3_stat_to_errno(status);
+}
+
+/*
+ * 3.3.18  FSSTAT3res
+ *
+ *	struct FSSTAT3resok {
+ *		post_op_attr	obj_attributes;
+ *		size3		tbytes;
+ *		size3		fbytes;
+ *		size3		abytes;
+ *		size3		tfiles;
+ *		size3		ffiles;
+ *		size3		afiles;
+ *		uint32		invarsec;
+ *	};
+ *
+ *	struct FSSTAT3resfail {
+ *		post_op_attr	obj_attributes;
+ *	};
+ *
+ *	union FSSTAT3res switch (nfsstat3 status) {
+ *	case NFS3_OK:
+ *		FSSTAT3resok	resok;
+ *	default:
+ *		FSSTAT3resfail	resfail;
+ *	};
+ */
+static int decode_fsstat3resok(struct xdr_stream *xdr,
+			       struct nfs_fsstat *result)
+{
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, 8 * 6 + 4);
+	if (unlikely(!p))
+		return -EIO;
+	p = xdr_decode_size3(p, &result->tbytes);
+	p = xdr_decode_size3(p, &result->fbytes);
+	p = xdr_decode_size3(p, &result->abytes);
+	p = xdr_decode_size3(p, &result->tfiles);
+	p = xdr_decode_size3(p, &result->ffiles);
+	xdr_decode_size3(p, &result->afiles);
+	/* ignore invarsec */
+	return 0;
+}
+
+static int nfs3_xdr_dec_fsstat3res(struct rpc_rqst *req,
+				   struct xdr_stream *xdr,
+				   void *data)
+{
+	struct nfs_fsstat *result = data;
+	enum nfs_stat status;
+	int error;
+
+	error = decode_nfsstat3(xdr, &status);
+	if (unlikely(error))
+		goto out;
+	error = decode_post_op_attr(xdr, result->fattr, rpc_rqst_userns(req));
+	if (unlikely(error))
+		goto out;
+	if (status != NFS3_OK)
+		goto out_status;
+	error = decode_fsstat3resok(xdr, result);
+out:
+	return error;
+out_status:
+	return nfs3_stat_to_errno(status);
+}
+
+/*
+ * 3.3.19  FSINFO3res
+ *
+ *	struct FSINFO3resok {
+ *		post_op_attr	obj_attributes;
+ *		uint32		rtmax;
+ *		uint32		rtpref;
+ *		uint32		rtmult;
+ *		uint32		wtmax;
+ *		uint32		wtpref;
+ *		uint32		wtmult;
+ *		uint32		dtpref;
+ *		size3		maxfilesize;
+ *		nfstime3	time_delta;
+ *		uint32		properties;
+ *	};
+ *
+ *	struct FSINFO3resfail {
+ *		post_op_attr	obj_attributes;
+ *	};
+ *
+ *	union FSINFO3res switch (nfsstat3 status) {
+ *	case NFS3_OK:
+ *		FSINFO3resok	resok;
+ *	default:
+ *		FSINFO3resfail	resfail;
+ *	};
+ */
+static int decode_fsinfo3resok(struct xdr_stream *xdr,
+			       struct nfs_fsinfo *result)
+{
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, 4 * 7 + 8 + 8 + 4);
+	if (unlikely(!p))
+		return -EIO;
+	result->rtmax  = be32_to_cpup(p++);
+	result->rtpref = be32_to_cpup(p++);
+	result->rtmult = be32_to_cpup(p++);
+	result->wtmax  = be32_to_cpup(p++);
+	result->wtpref = be32_to_cpup(p++);
+	result->wtmult = be32_to_cpup(p++);
+	result->dtpref = be32_to_cpup(p++);
+	p = xdr_decode_size3(p, &result->maxfilesize);
+	xdr_decode_nfstime3(p, &result->time_delta);
+
+	/* ignore properties */
+	result->lease_time = 0;
+	return 0;
+}
+
+static int nfs3_xdr_dec_fsinfo3res(struct rpc_rqst *req,
+				   struct xdr_stream *xdr,
+				   void *data)
+{
+	struct nfs_fsinfo *result = data;
+	enum nfs_stat status;
+	int error;
+
+	error = decode_nfsstat3(xdr, &status);
+	if (unlikely(error))
+		goto out;
+	error = decode_post_op_attr(xdr, result->fattr, rpc_rqst_userns(req));
+	if (unlikely(error))
+		goto out;
+	if (status != NFS3_OK)
+		goto out_status;
+	error = decode_fsinfo3resok(xdr, result);
+out:
+	return error;
+out_status:
+	return nfs3_stat_to_errno(status);
+}
+
+/*
+ * 3.3.20  PATHCONF3res
+ *
+ *	struct PATHCONF3resok {
+ *		post_op_attr	obj_attributes;
+ *		uint32		linkmax;
+ *		uint32		name_max;
+ *		bool		no_trunc;
+ *		bool		chown_restricted;
+ *		bool		case_insensitive;
+ *		bool		case_preserving;
+ *	};
+ *
+ *	struct PATHCONF3resfail {
+ *		post_op_attr	obj_attributes;
+ *	};
+ *
+ *	union PATHCONF3res switch (nfsstat3 status) {
+ *	case NFS3_OK:
+ *		PATHCONF3resok	resok;
+ *	default:
+ *		PATHCONF3resfail resfail;
+ *	};
+ */
+static int decode_pathconf3resok(struct xdr_stream *xdr,
+				 struct nfs_pathconf *result)
+{
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, 4 * 6);
+	if (unlikely(!p))
+		return -EIO;
+	result->max_link = be32_to_cpup(p++);
+	result->max_namelen = be32_to_cpup(p);
+	/* ignore remaining fields */
+	return 0;
+}
+
+static int nfs3_xdr_dec_pathconf3res(struct rpc_rqst *req,
+				     struct xdr_stream *xdr,
+				     void *data)
+{
+	struct nfs_pathconf *result = data;
+	enum nfs_stat status;
+	int error;
+
+	error = decode_nfsstat3(xdr, &status);
+	if (unlikely(error))
+		goto out;
+	error = decode_post_op_attr(xdr, result->fattr, rpc_rqst_userns(req));
+	if (unlikely(error))
+		goto out;
+	if (status != NFS3_OK)
+		goto out_status;
+	error = decode_pathconf3resok(xdr, result);
+out:
+	return error;
+out_status:
+	return nfs3_stat_to_errno(status);
+}
+
+/*
+ * 3.3.21  COMMIT3res
+ *
+ *	struct COMMIT3resok {
+ *		wcc_data	file_wcc;
+ *		writeverf3	verf;
+ *	};
+ *
+ *	struct COMMIT3resfail {
+ *		wcc_data	file_wcc;
+ *	};
+ *
+ *	union COMMIT3res switch (nfsstat3 status) {
+ *	case NFS3_OK:
+ *		COMMIT3resok	resok;
+ *	default:
+ *		COMMIT3resfail	resfail;
+ *	};
+ */
+static int nfs3_xdr_dec_commit3res(struct rpc_rqst *req,
+				   struct xdr_stream *xdr,
+				   void *data)
+{
+	struct nfs_commitres *result = data;
+	struct nfs_writeverf *verf = result->verf;
+	enum nfs_stat status;
+	int error;
+
+	error = decode_nfsstat3(xdr, &status);
+	if (unlikely(error))
+		goto out;
+	error = decode_wcc_data(xdr, result->fattr, rpc_rqst_userns(req));
+	if (unlikely(error))
+		goto out;
+	result->op_status = status;
+	if (status != NFS3_OK)
+		goto out_status;
+	error = decode_writeverf3(xdr, &verf->verifier);
+	if (!error)
+		verf->committed = NFS_FILE_SYNC;
+out:
+	return error;
+out_status:
+	return nfs3_stat_to_errno(status);
+}
+
+#ifdef CONFIG_NFS_V3_ACL
+
+static inline int decode_getacl3resok(struct xdr_stream *xdr,
+				      struct nfs3_getaclres *result,
+				      struct user_namespace *userns)
+{
+	struct posix_acl **acl;
+	unsigned int *aclcnt;
+	size_t hdrlen;
+	int error;
+
+	error = decode_post_op_attr(xdr, result->fattr, userns);
+	if (unlikely(error))
+		goto out;
+	error = decode_uint32(xdr, &result->mask);
+	if (unlikely(error))
+		goto out;
+	error = -EINVAL;
+	if (result->mask & ~(NFS_ACL|NFS_ACLCNT|NFS_DFACL|NFS_DFACLCNT))
+		goto out;
+
+	hdrlen = xdr_stream_pos(xdr);
+
+	acl = NULL;
+	if (result->mask & NFS_ACL)
+		acl = &result->acl_access;
+	aclcnt = NULL;
+	if (result->mask & NFS_ACLCNT)
+		aclcnt = &result->acl_access_count;
+	error = nfsacl_decode(xdr->buf, hdrlen, aclcnt, acl);
+	if (unlikely(error <= 0))
+		goto out;
+
+	acl = NULL;
+	if (result->mask & NFS_DFACL)
+		acl = &result->acl_default;
+	aclcnt = NULL;
+	if (result->mask & NFS_DFACLCNT)
+		aclcnt = &result->acl_default_count;
+	error = nfsacl_decode(xdr->buf, hdrlen + error, aclcnt, acl);
+	if (unlikely(error <= 0))
+		return error;
+	error = 0;
+out:
+	return error;
+}
+
+static int nfs3_xdr_dec_getacl3res(struct rpc_rqst *req,
+				   struct xdr_stream *xdr,
+				   void *result)
+{
+	enum nfs_stat status;
+	int error;
+
+	error = decode_nfsstat3(xdr, &status);
+	if (unlikely(error))
+		goto out;
+	if (status != NFS3_OK)
+		goto out_default;
+	error = decode_getacl3resok(xdr, result, rpc_rqst_userns(req));
+out:
+	return error;
+out_default:
+	return nfs3_stat_to_errno(status);
+}
+
+static int nfs3_xdr_dec_setacl3res(struct rpc_rqst *req,
+				   struct xdr_stream *xdr,
+				   void *result)
+{
+	enum nfs_stat status;
+	int error;
+
+	error = decode_nfsstat3(xdr, &status);
+	if (unlikely(error))
+		goto out;
+	if (status != NFS3_OK)
+		goto out_default;
+	error = decode_post_op_attr(xdr, result, rpc_rqst_userns(req));
+out:
+	return error;
+out_default:
+	return nfs3_stat_to_errno(status);
+}
+
+#endif  /* CONFIG_NFS_V3_ACL */
+
+
+/*
+ * We need to translate between nfs status return values and
+ * the local errno values which may not be the same.
+ */
+static const struct {
+	int stat;
+	int errno;
+} nfs_errtbl[] = {
+	{ NFS_OK,		0		},
+	{ NFSERR_PERM,		-EPERM		},
+	{ NFSERR_NOENT,		-ENOENT		},
+	{ NFSERR_IO,		-errno_NFSERR_IO},
+	{ NFSERR_NXIO,		-ENXIO		},
+/*	{ NFSERR_EAGAIN,	-EAGAIN		}, */
+	{ NFSERR_ACCES,		-EACCES		},
+	{ NFSERR_EXIST,		-EEXIST		},
+	{ NFSERR_XDEV,		-EXDEV		},
+	{ NFSERR_NODEV,		-ENODEV		},
+	{ NFSERR_NOTDIR,	-ENOTDIR	},
+	{ NFSERR_ISDIR,		-EISDIR		},
+	{ NFSERR_INVAL,		-EINVAL		},
+	{ NFSERR_FBIG,		-EFBIG		},
+	{ NFSERR_NOSPC,		-ENOSPC		},
+	{ NFSERR_ROFS,		-EROFS		},
+	{ NFSERR_MLINK,		-EMLINK		},
+	{ NFSERR_NAMETOOLONG,	-ENAMETOOLONG	},
+	{ NFSERR_NOTEMPTY,	-ENOTEMPTY	},
+	{ NFSERR_DQUOT,		-EDQUOT		},
+	{ NFSERR_STALE,		-ESTALE		},
+	{ NFSERR_REMOTE,	-EREMOTE	},
+#ifdef EWFLUSH
+	{ NFSERR_WFLUSH,	-EWFLUSH	},
+#endif
+	{ NFSERR_BADHANDLE,	-EBADHANDLE	},
+	{ NFSERR_NOT_SYNC,	-ENOTSYNC	},
+	{ NFSERR_BAD_COOKIE,	-EBADCOOKIE	},
+	{ NFSERR_NOTSUPP,	-ENOTSUPP	},
+	{ NFSERR_TOOSMALL,	-ETOOSMALL	},
+	{ NFSERR_SERVERFAULT,	-EREMOTEIO	},
+	{ NFSERR_BADTYPE,	-EBADTYPE	},
+	{ NFSERR_JUKEBOX,	-EJUKEBOX	},
+	{ -1,			-EIO		}
+};
+
+/**
+ * nfs3_stat_to_errno - convert an NFS status code to a local errno
+ * @status: NFS status code to convert
+ *
+ * Returns a local errno value, or -EIO if the NFS status code is
+ * not recognized.  This function is used jointly by NFSv2 and NFSv3.
+ */
+static int nfs3_stat_to_errno(enum nfs_stat status)
+{
+	int i;
+
+	for (i = 0; nfs_errtbl[i].stat != -1; i++) {
+		if (nfs_errtbl[i].stat == (int)status)
+			return nfs_errtbl[i].errno;
+	}
+	dprintk("NFS: Unrecognized nfs status value: %u\n", status);
+	return nfs_errtbl[i].errno;
+}
+
+
+#define PROC(proc, argtype, restype, timer)				\
+[NFS3PROC_##proc] = {							\
+	.p_proc      = NFS3PROC_##proc,					\
+	.p_encode    = nfs3_xdr_enc_##argtype##3args,			\
+	.p_decode    = nfs3_xdr_dec_##restype##3res,			\
+	.p_arglen    = NFS3_##argtype##args_sz,				\
+	.p_replen    = NFS3_##restype##res_sz,				\
+	.p_timer     = timer,						\
+	.p_statidx   = NFS3PROC_##proc,					\
+	.p_name      = #proc,						\
+	}
+
+const struct rpc_procinfo nfs3_procedures[] = {
+	PROC(GETATTR,		getattr,	getattr,	1),
+	PROC(SETATTR,		setattr,	setattr,	0),
+	PROC(LOOKUP,		lookup,		lookup,		2),
+	PROC(ACCESS,		access,		access,		1),
+	PROC(READLINK,		readlink,	readlink,	3),
+	PROC(READ,		read,		read,		3),
+	PROC(WRITE,		write,		write,		4),
+	PROC(CREATE,		create,		create,		0),
+	PROC(MKDIR,		mkdir,		create,		0),
+	PROC(SYMLINK,		symlink,	create,		0),
+	PROC(MKNOD,		mknod,		create,		0),
+	PROC(REMOVE,		remove,		remove,		0),
+	PROC(RMDIR,		lookup,		setattr,	0),
+	PROC(RENAME,		rename,		rename,		0),
+	PROC(LINK,		link,		link,		0),
+	PROC(READDIR,		readdir,	readdir,	3),
+	PROC(READDIRPLUS,	readdirplus,	readdir,	3),
+	PROC(FSSTAT,		getattr,	fsstat,		0),
+	PROC(FSINFO,		getattr,	fsinfo,		0),
+	PROC(PATHCONF,		getattr,	pathconf,	0),
+	PROC(COMMIT,		commit,		commit,		5),
+};
+
+static unsigned int nfs_version3_counts[ARRAY_SIZE(nfs3_procedures)];
+const struct rpc_version nfs_version3 = {
+	.number			= 3,
+	.nrprocs		= ARRAY_SIZE(nfs3_procedures),
+	.procs			= nfs3_procedures,
+	.counts			= nfs_version3_counts,
+};
+
+#ifdef CONFIG_NFS_V3_ACL
+static const struct rpc_procinfo nfs3_acl_procedures[] = {
+	[ACLPROC3_GETACL] = {
+		.p_proc = ACLPROC3_GETACL,
+		.p_encode = nfs3_xdr_enc_getacl3args,
+		.p_decode = nfs3_xdr_dec_getacl3res,
+		.p_arglen = ACL3_getaclargs_sz,
+		.p_replen = ACL3_getaclres_sz,
+		.p_timer = 1,
+		.p_name = "GETACL",
+	},
+	[ACLPROC3_SETACL] = {
+		.p_proc = ACLPROC3_SETACL,
+		.p_encode = nfs3_xdr_enc_setacl3args,
+		.p_decode = nfs3_xdr_dec_setacl3res,
+		.p_arglen = ACL3_setaclargs_sz,
+		.p_replen = ACL3_setaclres_sz,
+		.p_timer = 0,
+		.p_name = "SETACL",
+	},
+};
+
+static unsigned int nfs3_acl_counts[ARRAY_SIZE(nfs3_acl_procedures)];
+const struct rpc_version nfsacl_version3 = {
+	.number			= 3,
+	.nrprocs		= ARRAY_SIZE(nfs3_acl_procedures),
+	.procs			= nfs3_acl_procedures,
+	.counts			= nfs3_acl_counts,
+};
+#endif  /* CONFIG_NFS_V3_ACL */
diff --git a/fs/nfs/nfs42.h b/fs/nfs/nfs42.h
new file mode 100644
index 000000000..0fe5aacbc
--- /dev/null
+++ b/fs/nfs/nfs42.h
@@ -0,0 +1,64 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2014 Anna Schumaker <Anna.Schumaker@Netapp.com>
+ */
+
+#ifndef __LINUX_FS_NFS_NFS4_2_H
+#define __LINUX_FS_NFS_NFS4_2_H
+
+#include <linux/xattr.h>
+
+/*
+ * FIXME:  four LAYOUTSTATS calls per compound at most! Do we need to support
+ * more? Need to consider not to pre-alloc too much for a compound.
+ */
+#define PNFS_LAYOUTSTATS_MAXDEV (4)
+
+/* nfs4.2proc.c */
+#ifdef CONFIG_NFS_V4_2
+int nfs42_proc_allocate(struct file *, loff_t, loff_t);
+ssize_t nfs42_proc_copy(struct file *, loff_t, struct file *, loff_t, size_t,
+			struct nl4_server *, nfs4_stateid *, bool);
+int nfs42_proc_deallocate(struct file *, loff_t, loff_t);
+loff_t nfs42_proc_llseek(struct file *, loff_t, int);
+int nfs42_proc_layoutstats_generic(struct nfs_server *,
+				   struct nfs42_layoutstat_data *);
+int nfs42_proc_clone(struct file *, struct file *, loff_t, loff_t, loff_t);
+int nfs42_proc_layouterror(struct pnfs_layout_segment *lseg,
+			   const struct nfs42_layout_error *errors,
+			   size_t n);
+int nfs42_proc_copy_notify(struct file *, struct file *,
+			   struct nfs42_copy_notify_res *);
+static inline bool nfs42_files_from_same_server(struct file *in,
+						struct file *out)
+{
+	struct nfs_client *c_in = (NFS_SERVER(file_inode(in)))->nfs_client;
+	struct nfs_client *c_out = (NFS_SERVER(file_inode(out)))->nfs_client;
+
+	return nfs4_check_serverowner_major_id(c_in->cl_serverowner,
+					       c_out->cl_serverowner);
+}
+
+ssize_t nfs42_proc_getxattr(struct inode *inode, const char *name,
+			    void *buf, size_t buflen);
+int nfs42_proc_setxattr(struct inode *inode, const char *name,
+			const void *buf, size_t buflen, int flags);
+ssize_t nfs42_proc_listxattrs(struct inode *inode, void *buf,
+			       size_t buflen, u64 *cookiep, bool *eofp);
+int nfs42_proc_removexattr(struct inode *inode, const char *name);
+
+/*
+ * Maximum XDR buffer size needed for a listxattr buffer of buflen size.
+ *
+ * The upper boundary is a buffer with all 1-byte sized attribute names.
+ * They would be 7 bytes long in the eventual buffer ("user.x\0"), and
+ * 8 bytes long XDR-encoded.
+ *
+ * Include the trailing eof word as well.
+ */
+static inline u32 nfs42_listxattr_xdrsize(u32 buflen)
+{
+	return ((buflen / (XATTR_USER_PREFIX_LEN + 2)) * 8) + 4;
+}
+#endif /* CONFIG_NFS_V4_2 */
+#endif /* __LINUX_FS_NFS_NFS4_2_H */
diff --git a/fs/nfs/nfs42proc.c b/fs/nfs/nfs42proc.c
new file mode 100644
index 000000000..dfeea7120
--- /dev/null
+++ b/fs/nfs/nfs42proc.c
@@ -0,0 +1,1373 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2014 Anna Schumaker <Anna.Schumaker@Netapp.com>
+ */
+#include <linux/fs.h>
+#include <linux/sunrpc/addr.h>
+#include <linux/sunrpc/sched.h>
+#include <linux/nfs.h>
+#include <linux/nfs3.h>
+#include <linux/nfs4.h>
+#include <linux/nfs_xdr.h>
+#include <linux/nfs_fs.h>
+#include "nfs4_fs.h"
+#include "nfs42.h"
+#include "iostat.h"
+#include "pnfs.h"
+#include "nfs4session.h"
+#include "internal.h"
+#include "delegation.h"
+#include "nfs4trace.h"
+
+#define NFSDBG_FACILITY NFSDBG_PROC
+static int nfs42_do_offload_cancel_async(struct file *dst, nfs4_stateid *std);
+
+static void nfs42_set_netaddr(struct file *filep, struct nfs42_netaddr *naddr)
+{
+	struct nfs_client *clp = (NFS_SERVER(file_inode(filep)))->nfs_client;
+	unsigned short port = 2049;
+
+	rcu_read_lock();
+	naddr->netid_len = scnprintf(naddr->netid,
+					sizeof(naddr->netid), "%s",
+					rpc_peeraddr2str(clp->cl_rpcclient,
+					RPC_DISPLAY_NETID));
+	naddr->addr_len = scnprintf(naddr->addr,
+					sizeof(naddr->addr),
+					"%s.%u.%u",
+					rpc_peeraddr2str(clp->cl_rpcclient,
+					RPC_DISPLAY_ADDR),
+					port >> 8, port & 255);
+	rcu_read_unlock();
+}
+
+static int _nfs42_proc_fallocate(struct rpc_message *msg, struct file *filep,
+		struct nfs_lock_context *lock, loff_t offset, loff_t len)
+{
+	struct inode *inode = file_inode(filep);
+	struct nfs_server *server = NFS_SERVER(inode);
+	u32 bitmask[3];
+	struct nfs42_falloc_args args = {
+		.falloc_fh	= NFS_FH(inode),
+		.falloc_offset	= offset,
+		.falloc_length	= len,
+		.falloc_bitmask	= bitmask,
+	};
+	struct nfs42_falloc_res res = {
+		.falloc_server	= server,
+	};
+	int status;
+
+	msg->rpc_argp = &args;
+	msg->rpc_resp = &res;
+
+	status = nfs4_set_rw_stateid(&args.falloc_stateid, lock->open_context,
+			lock, FMODE_WRITE);
+	if (status) {
+		if (status == -EAGAIN)
+			status = -NFS4ERR_BAD_STATEID;
+		return status;
+	}
+
+	memcpy(bitmask, server->cache_consistency_bitmask, sizeof(bitmask));
+	if (server->attr_bitmask[1] & FATTR4_WORD1_SPACE_USED)
+		bitmask[1] |= FATTR4_WORD1_SPACE_USED;
+
+	res.falloc_fattr = nfs_alloc_fattr();
+	if (!res.falloc_fattr)
+		return -ENOMEM;
+
+	status = nfs4_call_sync(server->client, server, msg,
+				&args.seq_args, &res.seq_res, 0);
+	if (status == 0)
+		status = nfs_post_op_update_inode_force_wcc(inode,
+							    res.falloc_fattr);
+
+	kfree(res.falloc_fattr);
+	return status;
+}
+
+static int nfs42_proc_fallocate(struct rpc_message *msg, struct file *filep,
+				loff_t offset, loff_t len)
+{
+	struct inode *inode = file_inode(filep);
+	struct nfs_server *server = NFS_SERVER(inode);
+	struct nfs4_exception exception = { };
+	struct nfs_lock_context *lock;
+	int err;
+
+	lock = nfs_get_lock_context(nfs_file_open_context(filep));
+	if (IS_ERR(lock))
+		return PTR_ERR(lock);
+
+	exception.inode = inode;
+	exception.state = lock->open_context->state;
+
+	err = nfs_sync_inode(inode);
+	if (err)
+		goto out;
+
+	do {
+		err = _nfs42_proc_fallocate(msg, filep, lock, offset, len);
+		if (err == -ENOTSUPP) {
+			err = -EOPNOTSUPP;
+			break;
+		}
+		err = nfs4_handle_exception(server, err, &exception);
+	} while (exception.retry);
+out:
+	nfs_put_lock_context(lock);
+	return err;
+}
+
+int nfs42_proc_allocate(struct file *filep, loff_t offset, loff_t len)
+{
+	struct rpc_message msg = {
+		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_ALLOCATE],
+	};
+	struct inode *inode = file_inode(filep);
+	int err;
+
+	if (!nfs_server_capable(inode, NFS_CAP_ALLOCATE))
+		return -EOPNOTSUPP;
+
+	inode_lock(inode);
+
+	err = nfs42_proc_fallocate(&msg, filep, offset, len);
+	if (err == -EOPNOTSUPP)
+		NFS_SERVER(inode)->caps &= ~NFS_CAP_ALLOCATE;
+
+	inode_unlock(inode);
+	return err;
+}
+
+int nfs42_proc_deallocate(struct file *filep, loff_t offset, loff_t len)
+{
+	struct rpc_message msg = {
+		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_DEALLOCATE],
+	};
+	struct inode *inode = file_inode(filep);
+	int err;
+
+	if (!nfs_server_capable(inode, NFS_CAP_DEALLOCATE))
+		return -EOPNOTSUPP;
+
+	inode_lock(inode);
+
+	err = nfs42_proc_fallocate(&msg, filep, offset, len);
+	if (err == 0)
+		truncate_pagecache_range(inode, offset, (offset + len) -1);
+	if (err == -EOPNOTSUPP)
+		NFS_SERVER(inode)->caps &= ~NFS_CAP_DEALLOCATE;
+
+	inode_unlock(inode);
+	return err;
+}
+
+static int handle_async_copy(struct nfs42_copy_res *res,
+			     struct nfs_server *dst_server,
+			     struct nfs_server *src_server,
+			     struct file *src,
+			     struct file *dst,
+			     nfs4_stateid *src_stateid,
+			     bool *restart)
+{
+	struct nfs4_copy_state *copy, *tmp_copy;
+	int status = NFS4_OK;
+	bool found_pending = false;
+	struct nfs_open_context *dst_ctx = nfs_file_open_context(dst);
+	struct nfs_open_context *src_ctx = nfs_file_open_context(src);
+
+	copy = kzalloc(sizeof(struct nfs4_copy_state), GFP_NOFS);
+	if (!copy)
+		return -ENOMEM;
+
+	spin_lock(&dst_server->nfs_client->cl_lock);
+	list_for_each_entry(tmp_copy,
+				&dst_server->nfs_client->pending_cb_stateids,
+				copies) {
+		if (memcmp(&res->write_res.stateid, &tmp_copy->stateid,
+				NFS4_STATEID_SIZE))
+			continue;
+		found_pending = true;
+		list_del(&tmp_copy->copies);
+		break;
+	}
+	if (found_pending) {
+		spin_unlock(&dst_server->nfs_client->cl_lock);
+		kfree(copy);
+		copy = tmp_copy;
+		goto out;
+	}
+
+	memcpy(&copy->stateid, &res->write_res.stateid, NFS4_STATEID_SIZE);
+	init_completion(&copy->completion);
+	copy->parent_dst_state = dst_ctx->state;
+	copy->parent_src_state = src_ctx->state;
+
+	list_add_tail(&copy->copies, &dst_server->ss_copies);
+	spin_unlock(&dst_server->nfs_client->cl_lock);
+
+	if (dst_server != src_server) {
+		spin_lock(&src_server->nfs_client->cl_lock);
+		list_add_tail(&copy->src_copies, &src_server->ss_copies);
+		spin_unlock(&src_server->nfs_client->cl_lock);
+	}
+
+	status = wait_for_completion_interruptible(&copy->completion);
+	spin_lock(&dst_server->nfs_client->cl_lock);
+	list_del_init(&copy->copies);
+	spin_unlock(&dst_server->nfs_client->cl_lock);
+	if (dst_server != src_server) {
+		spin_lock(&src_server->nfs_client->cl_lock);
+		list_del_init(&copy->src_copies);
+		spin_unlock(&src_server->nfs_client->cl_lock);
+	}
+	if (status == -ERESTARTSYS) {
+		goto out_cancel;
+	} else if (copy->flags || copy->error == NFS4ERR_PARTNER_NO_AUTH) {
+		status = -EAGAIN;
+		*restart = true;
+		goto out_cancel;
+	}
+out:
+	res->write_res.count = copy->count;
+	memcpy(&res->write_res.verifier, &copy->verf, sizeof(copy->verf));
+	status = -copy->error;
+
+out_free:
+	kfree(copy);
+	return status;
+out_cancel:
+	nfs42_do_offload_cancel_async(dst, &copy->stateid);
+	if (!nfs42_files_from_same_server(src, dst))
+		nfs42_do_offload_cancel_async(src, src_stateid);
+	goto out_free;
+}
+
+static int process_copy_commit(struct file *dst, loff_t pos_dst,
+			       struct nfs42_copy_res *res)
+{
+	struct nfs_commitres cres;
+	int status = -ENOMEM;
+
+	cres.verf = kzalloc(sizeof(struct nfs_writeverf), GFP_NOFS);
+	if (!cres.verf)
+		goto out;
+
+	status = nfs4_proc_commit(dst, pos_dst, res->write_res.count, &cres);
+	if (status)
+		goto out_free;
+	if (nfs_write_verifier_cmp(&res->write_res.verifier.verifier,
+				    &cres.verf->verifier)) {
+		dprintk("commit verf differs from copy verf\n");
+		status = -EAGAIN;
+	}
+out_free:
+	kfree(cres.verf);
+out:
+	return status;
+}
+
+static ssize_t _nfs42_proc_copy(struct file *src,
+				struct nfs_lock_context *src_lock,
+				struct file *dst,
+				struct nfs_lock_context *dst_lock,
+				struct nfs42_copy_args *args,
+				struct nfs42_copy_res *res,
+				struct nl4_server *nss,
+				nfs4_stateid *cnr_stateid,
+				bool *restart)
+{
+	struct rpc_message msg = {
+		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_COPY],
+		.rpc_argp = args,
+		.rpc_resp = res,
+	};
+	struct inode *dst_inode = file_inode(dst);
+	struct inode *src_inode = file_inode(src);
+	struct nfs_server *dst_server = NFS_SERVER(dst_inode);
+	struct nfs_server *src_server = NFS_SERVER(src_inode);
+	loff_t pos_src = args->src_pos;
+	loff_t pos_dst = args->dst_pos;
+	size_t count = args->count;
+	ssize_t status;
+
+	if (nss) {
+		args->cp_src = nss;
+		nfs4_stateid_copy(&args->src_stateid, cnr_stateid);
+	} else {
+		status = nfs4_set_rw_stateid(&args->src_stateid,
+				src_lock->open_context, src_lock, FMODE_READ);
+		if (status) {
+			if (status == -EAGAIN)
+				status = -NFS4ERR_BAD_STATEID;
+			return status;
+		}
+	}
+	status = nfs_filemap_write_and_wait_range(file_inode(src)->i_mapping,
+			pos_src, pos_src + (loff_t)count - 1);
+	if (status)
+		return status;
+
+	status = nfs4_set_rw_stateid(&args->dst_stateid, dst_lock->open_context,
+				     dst_lock, FMODE_WRITE);
+	if (status) {
+		if (status == -EAGAIN)
+			status = -NFS4ERR_BAD_STATEID;
+		return status;
+	}
+
+	status = nfs_sync_inode(dst_inode);
+	if (status)
+		return status;
+
+	res->commit_res.verf = NULL;
+	if (args->sync) {
+		res->commit_res.verf =
+			kzalloc(sizeof(struct nfs_writeverf), GFP_NOFS);
+		if (!res->commit_res.verf)
+			return -ENOMEM;
+	}
+	set_bit(NFS_CLNT_SRC_SSC_COPY_STATE,
+		&src_lock->open_context->state->flags);
+	set_bit(NFS_CLNT_DST_SSC_COPY_STATE,
+		&dst_lock->open_context->state->flags);
+
+	status = nfs4_call_sync(dst_server->client, dst_server, &msg,
+				&args->seq_args, &res->seq_res, 0);
+	if (status == -ENOTSUPP)
+		dst_server->caps &= ~NFS_CAP_COPY;
+	if (status)
+		goto out;
+
+	if (args->sync &&
+		nfs_write_verifier_cmp(&res->write_res.verifier.verifier,
+				    &res->commit_res.verf->verifier)) {
+		status = -EAGAIN;
+		goto out;
+	}
+
+	if (!res->synchronous) {
+		status = handle_async_copy(res, dst_server, src_server, src,
+				dst, &args->src_stateid, restart);
+		if (status)
+			goto out;
+	}
+
+	if ((!res->synchronous || !args->sync) &&
+			res->write_res.verifier.committed != NFS_FILE_SYNC) {
+		status = process_copy_commit(dst, pos_dst, res);
+		if (status)
+			goto out;
+	}
+
+	WARN_ON_ONCE(invalidate_inode_pages2_range(dst_inode->i_mapping,
+					pos_dst >> PAGE_SHIFT,
+					(pos_dst + res->write_res.count - 1) >> PAGE_SHIFT));
+	spin_lock(&dst_inode->i_lock);
+	NFS_I(dst_inode)->cache_validity |= (NFS_INO_REVAL_PAGECACHE |
+			NFS_INO_REVAL_FORCED | NFS_INO_INVALID_SIZE |
+			NFS_INO_INVALID_ATTR | NFS_INO_INVALID_DATA);
+	spin_unlock(&dst_inode->i_lock);
+	spin_lock(&src_inode->i_lock);
+	NFS_I(src_inode)->cache_validity |= (NFS_INO_REVAL_PAGECACHE |
+			NFS_INO_REVAL_FORCED | NFS_INO_INVALID_ATIME);
+	spin_unlock(&src_inode->i_lock);
+	status = res->write_res.count;
+out:
+	if (args->sync)
+		kfree(res->commit_res.verf);
+	return status;
+}
+
+ssize_t nfs42_proc_copy(struct file *src, loff_t pos_src,
+			struct file *dst, loff_t pos_dst, size_t count,
+			struct nl4_server *nss,
+			nfs4_stateid *cnr_stateid, bool sync)
+{
+	struct nfs_server *server = NFS_SERVER(file_inode(dst));
+	struct nfs_lock_context *src_lock;
+	struct nfs_lock_context *dst_lock;
+	struct nfs42_copy_args args = {
+		.src_fh		= NFS_FH(file_inode(src)),
+		.src_pos	= pos_src,
+		.dst_fh		= NFS_FH(file_inode(dst)),
+		.dst_pos	= pos_dst,
+		.count		= count,
+		.sync		= sync,
+	};
+	struct nfs42_copy_res res;
+	struct nfs4_exception src_exception = {
+		.inode		= file_inode(src),
+		.stateid	= &args.src_stateid,
+	};
+	struct nfs4_exception dst_exception = {
+		.inode		= file_inode(dst),
+		.stateid	= &args.dst_stateid,
+	};
+	ssize_t err, err2;
+	bool restart = false;
+
+	src_lock = nfs_get_lock_context(nfs_file_open_context(src));
+	if (IS_ERR(src_lock))
+		return PTR_ERR(src_lock);
+
+	src_exception.state = src_lock->open_context->state;
+
+	dst_lock = nfs_get_lock_context(nfs_file_open_context(dst));
+	if (IS_ERR(dst_lock)) {
+		err = PTR_ERR(dst_lock);
+		goto out_put_src_lock;
+	}
+
+	dst_exception.state = dst_lock->open_context->state;
+
+	do {
+		inode_lock(file_inode(dst));
+		err = _nfs42_proc_copy(src, src_lock,
+				dst, dst_lock,
+				&args, &res,
+				nss, cnr_stateid, &restart);
+		inode_unlock(file_inode(dst));
+
+		if (err >= 0)
+			break;
+		if (err == -ENOTSUPP &&
+				nfs42_files_from_same_server(src, dst)) {
+			err = -EOPNOTSUPP;
+			break;
+		} else if (err == -EAGAIN) {
+			if (!restart) {
+				dst_exception.retry = 1;
+				continue;
+			}
+			break;
+		} else if (err == -NFS4ERR_OFFLOAD_NO_REQS &&
+				args.sync != res.synchronous) {
+			args.sync = res.synchronous;
+			dst_exception.retry = 1;
+			continue;
+		} else if ((err == -ESTALE ||
+				err == -NFS4ERR_OFFLOAD_DENIED ||
+				err == -ENOTSUPP) &&
+				!nfs42_files_from_same_server(src, dst)) {
+			nfs42_do_offload_cancel_async(src, &args.src_stateid);
+			err = -EOPNOTSUPP;
+			break;
+		}
+
+		err2 = nfs4_handle_exception(server, err, &src_exception);
+		err  = nfs4_handle_exception(server, err, &dst_exception);
+		if (!err)
+			err = err2;
+	} while (src_exception.retry || dst_exception.retry);
+
+	nfs_put_lock_context(dst_lock);
+out_put_src_lock:
+	nfs_put_lock_context(src_lock);
+	return err;
+}
+
+struct nfs42_offloadcancel_data {
+	struct nfs_server *seq_server;
+	struct nfs42_offload_status_args args;
+	struct nfs42_offload_status_res res;
+};
+
+static void nfs42_offload_cancel_prepare(struct rpc_task *task, void *calldata)
+{
+	struct nfs42_offloadcancel_data *data = calldata;
+
+	nfs4_setup_sequence(data->seq_server->nfs_client,
+				&data->args.osa_seq_args,
+				&data->res.osr_seq_res, task);
+}
+
+static void nfs42_offload_cancel_done(struct rpc_task *task, void *calldata)
+{
+	struct nfs42_offloadcancel_data *data = calldata;
+
+	nfs41_sequence_done(task, &data->res.osr_seq_res);
+	if (task->tk_status &&
+		nfs4_async_handle_error(task, data->seq_server, NULL,
+			NULL) == -EAGAIN)
+		rpc_restart_call_prepare(task);
+}
+
+static void nfs42_free_offloadcancel_data(void *data)
+{
+	kfree(data);
+}
+
+static const struct rpc_call_ops nfs42_offload_cancel_ops = {
+	.rpc_call_prepare = nfs42_offload_cancel_prepare,
+	.rpc_call_done = nfs42_offload_cancel_done,
+	.rpc_release = nfs42_free_offloadcancel_data,
+};
+
+static int nfs42_do_offload_cancel_async(struct file *dst,
+					 nfs4_stateid *stateid)
+{
+	struct nfs_server *dst_server = NFS_SERVER(file_inode(dst));
+	struct nfs42_offloadcancel_data *data = NULL;
+	struct nfs_open_context *ctx = nfs_file_open_context(dst);
+	struct rpc_task *task;
+	struct rpc_message msg = {
+		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_OFFLOAD_CANCEL],
+		.rpc_cred = ctx->cred,
+	};
+	struct rpc_task_setup task_setup_data = {
+		.rpc_client = dst_server->client,
+		.rpc_message = &msg,
+		.callback_ops = &nfs42_offload_cancel_ops,
+		.workqueue = nfsiod_workqueue,
+		.flags = RPC_TASK_ASYNC,
+	};
+	int status;
+
+	if (!(dst_server->caps & NFS_CAP_OFFLOAD_CANCEL))
+		return -EOPNOTSUPP;
+
+	data = kzalloc(sizeof(struct nfs42_offloadcancel_data), GFP_NOFS);
+	if (data == NULL)
+		return -ENOMEM;
+
+	data->seq_server = dst_server;
+	data->args.osa_src_fh = NFS_FH(file_inode(dst));
+	memcpy(&data->args.osa_stateid, stateid,
+		sizeof(data->args.osa_stateid));
+	msg.rpc_argp = &data->args;
+	msg.rpc_resp = &data->res;
+	task_setup_data.callback_data = data;
+	nfs4_init_sequence(&data->args.osa_seq_args, &data->res.osr_seq_res,
+			   1, 0);
+	task = rpc_run_task(&task_setup_data);
+	if (IS_ERR(task))
+		return PTR_ERR(task);
+	status = rpc_wait_for_completion_task(task);
+	if (status == -ENOTSUPP)
+		dst_server->caps &= ~NFS_CAP_OFFLOAD_CANCEL;
+	rpc_put_task(task);
+	return status;
+}
+
+static int _nfs42_proc_copy_notify(struct file *src, struct file *dst,
+				   struct nfs42_copy_notify_args *args,
+				   struct nfs42_copy_notify_res *res)
+{
+	struct nfs_server *src_server = NFS_SERVER(file_inode(src));
+	struct rpc_message msg = {
+		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_COPY_NOTIFY],
+		.rpc_argp = args,
+		.rpc_resp = res,
+	};
+	int status;
+	struct nfs_open_context *ctx;
+	struct nfs_lock_context *l_ctx;
+
+	ctx = get_nfs_open_context(nfs_file_open_context(src));
+	l_ctx = nfs_get_lock_context(ctx);
+	if (IS_ERR(l_ctx)) {
+		status = PTR_ERR(l_ctx);
+		goto out;
+	}
+
+	status = nfs4_set_rw_stateid(&args->cna_src_stateid, ctx, l_ctx,
+				     FMODE_READ);
+	nfs_put_lock_context(l_ctx);
+	if (status) {
+		if (status == -EAGAIN)
+			status = -NFS4ERR_BAD_STATEID;
+		goto out;
+	}
+
+	status = nfs4_call_sync(src_server->client, src_server, &msg,
+				&args->cna_seq_args, &res->cnr_seq_res, 0);
+	if (status == -ENOTSUPP)
+		src_server->caps &= ~NFS_CAP_COPY_NOTIFY;
+
+out:
+	put_nfs_open_context(nfs_file_open_context(src));
+	return status;
+}
+
+int nfs42_proc_copy_notify(struct file *src, struct file *dst,
+				struct nfs42_copy_notify_res *res)
+{
+	struct nfs_server *src_server = NFS_SERVER(file_inode(src));
+	struct nfs42_copy_notify_args *args;
+	struct nfs4_exception exception = {
+		.inode = file_inode(src),
+	};
+	int status;
+
+	if (!(src_server->caps & NFS_CAP_COPY_NOTIFY))
+		return -EOPNOTSUPP;
+
+	args = kzalloc(sizeof(struct nfs42_copy_notify_args), GFP_NOFS);
+	if (args == NULL)
+		return -ENOMEM;
+
+	args->cna_src_fh  = NFS_FH(file_inode(src)),
+	args->cna_dst.nl4_type = NL4_NETADDR;
+	nfs42_set_netaddr(dst, &args->cna_dst.u.nl4_addr);
+	exception.stateid = &args->cna_src_stateid;
+
+	do {
+		status = _nfs42_proc_copy_notify(src, dst, args, res);
+		if (status == -ENOTSUPP) {
+			status = -EOPNOTSUPP;
+			goto out;
+		}
+		status = nfs4_handle_exception(src_server, status, &exception);
+	} while (exception.retry);
+
+out:
+	kfree(args);
+	return status;
+}
+
+static loff_t _nfs42_proc_llseek(struct file *filep,
+		struct nfs_lock_context *lock, loff_t offset, int whence)
+{
+	struct inode *inode = file_inode(filep);
+	struct nfs42_seek_args args = {
+		.sa_fh		= NFS_FH(inode),
+		.sa_offset	= offset,
+		.sa_what	= (whence == SEEK_HOLE) ?
+					NFS4_CONTENT_HOLE : NFS4_CONTENT_DATA,
+	};
+	struct nfs42_seek_res res;
+	struct rpc_message msg = {
+		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_SEEK],
+		.rpc_argp = &args,
+		.rpc_resp = &res,
+	};
+	struct nfs_server *server = NFS_SERVER(inode);
+	int status;
+
+	if (!nfs_server_capable(inode, NFS_CAP_SEEK))
+		return -ENOTSUPP;
+
+	status = nfs4_set_rw_stateid(&args.sa_stateid, lock->open_context,
+			lock, FMODE_READ);
+	if (status) {
+		if (status == -EAGAIN)
+			status = -NFS4ERR_BAD_STATEID;
+		return status;
+	}
+
+	status = nfs_filemap_write_and_wait_range(inode->i_mapping,
+			offset, LLONG_MAX);
+	if (status)
+		return status;
+
+	status = nfs4_call_sync(server->client, server, &msg,
+				&args.seq_args, &res.seq_res, 0);
+	if (status == -ENOTSUPP)
+		server->caps &= ~NFS_CAP_SEEK;
+	if (status)
+		return status;
+
+	if (whence == SEEK_DATA && res.sr_eof)
+		return -NFS4ERR_NXIO;
+	else
+		return vfs_setpos(filep, res.sr_offset, inode->i_sb->s_maxbytes);
+}
+
+loff_t nfs42_proc_llseek(struct file *filep, loff_t offset, int whence)
+{
+	struct nfs_server *server = NFS_SERVER(file_inode(filep));
+	struct nfs4_exception exception = { };
+	struct nfs_lock_context *lock;
+	loff_t err;
+
+	lock = nfs_get_lock_context(nfs_file_open_context(filep));
+	if (IS_ERR(lock))
+		return PTR_ERR(lock);
+
+	exception.inode = file_inode(filep);
+	exception.state = lock->open_context->state;
+
+	do {
+		err = _nfs42_proc_llseek(filep, lock, offset, whence);
+		if (err >= 0)
+			break;
+		if (err == -ENOTSUPP) {
+			err = -EOPNOTSUPP;
+			break;
+		}
+		err = nfs4_handle_exception(server, err, &exception);
+	} while (exception.retry);
+
+	nfs_put_lock_context(lock);
+	return err;
+}
+
+
+static void
+nfs42_layoutstat_prepare(struct rpc_task *task, void *calldata)
+{
+	struct nfs42_layoutstat_data *data = calldata;
+	struct inode *inode = data->inode;
+	struct nfs_server *server = NFS_SERVER(inode);
+	struct pnfs_layout_hdr *lo;
+
+	spin_lock(&inode->i_lock);
+	lo = NFS_I(inode)->layout;
+	if (!pnfs_layout_is_valid(lo)) {
+		spin_unlock(&inode->i_lock);
+		rpc_exit(task, 0);
+		return;
+	}
+	nfs4_stateid_copy(&data->args.stateid, &lo->plh_stateid);
+	spin_unlock(&inode->i_lock);
+	nfs4_setup_sequence(server->nfs_client, &data->args.seq_args,
+			    &data->res.seq_res, task);
+}
+
+static void
+nfs42_layoutstat_done(struct rpc_task *task, void *calldata)
+{
+	struct nfs42_layoutstat_data *data = calldata;
+	struct inode *inode = data->inode;
+	struct pnfs_layout_hdr *lo;
+
+	if (!nfs4_sequence_done(task, &data->res.seq_res))
+		return;
+
+	switch (task->tk_status) {
+	case 0:
+		return;
+	case -NFS4ERR_BADHANDLE:
+	case -ESTALE:
+		pnfs_destroy_layout(NFS_I(inode));
+		break;
+	case -NFS4ERR_EXPIRED:
+	case -NFS4ERR_ADMIN_REVOKED:
+	case -NFS4ERR_DELEG_REVOKED:
+	case -NFS4ERR_STALE_STATEID:
+	case -NFS4ERR_BAD_STATEID:
+		spin_lock(&inode->i_lock);
+		lo = NFS_I(inode)->layout;
+		if (pnfs_layout_is_valid(lo) &&
+		    nfs4_stateid_match(&data->args.stateid,
+					     &lo->plh_stateid)) {
+			LIST_HEAD(head);
+
+			/*
+			 * Mark the bad layout state as invalid, then retry
+			 * with the current stateid.
+			 */
+			pnfs_mark_layout_stateid_invalid(lo, &head);
+			spin_unlock(&inode->i_lock);
+			pnfs_free_lseg_list(&head);
+			nfs_commit_inode(inode, 0);
+		} else
+			spin_unlock(&inode->i_lock);
+		break;
+	case -NFS4ERR_OLD_STATEID:
+		spin_lock(&inode->i_lock);
+		lo = NFS_I(inode)->layout;
+		if (pnfs_layout_is_valid(lo) &&
+		    nfs4_stateid_match_other(&data->args.stateid,
+					&lo->plh_stateid)) {
+			/* Do we need to delay before resending? */
+			if (!nfs4_stateid_is_newer(&lo->plh_stateid,
+						&data->args.stateid))
+				rpc_delay(task, HZ);
+			rpc_restart_call_prepare(task);
+		}
+		spin_unlock(&inode->i_lock);
+		break;
+	case -ENOTSUPP:
+	case -EOPNOTSUPP:
+		NFS_SERVER(inode)->caps &= ~NFS_CAP_LAYOUTSTATS;
+	}
+
+	trace_nfs4_layoutstats(inode, &data->args.stateid, task->tk_status);
+}
+
+static void
+nfs42_layoutstat_release(void *calldata)
+{
+	struct nfs42_layoutstat_data *data = calldata;
+	struct nfs42_layoutstat_devinfo *devinfo = data->args.devinfo;
+	int i;
+
+	for (i = 0; i < data->args.num_dev; i++) {
+		if (devinfo[i].ld_private.ops && devinfo[i].ld_private.ops->free)
+			devinfo[i].ld_private.ops->free(&devinfo[i].ld_private);
+	}
+
+	pnfs_put_layout_hdr(NFS_I(data->args.inode)->layout);
+	smp_mb__before_atomic();
+	clear_bit(NFS_INO_LAYOUTSTATS, &NFS_I(data->args.inode)->flags);
+	smp_mb__after_atomic();
+	nfs_iput_and_deactive(data->inode);
+	kfree(data->args.devinfo);
+	kfree(data);
+}
+
+static const struct rpc_call_ops nfs42_layoutstat_ops = {
+	.rpc_call_prepare = nfs42_layoutstat_prepare,
+	.rpc_call_done = nfs42_layoutstat_done,
+	.rpc_release = nfs42_layoutstat_release,
+};
+
+int nfs42_proc_layoutstats_generic(struct nfs_server *server,
+				   struct nfs42_layoutstat_data *data)
+{
+	struct rpc_message msg = {
+		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_LAYOUTSTATS],
+		.rpc_argp = &data->args,
+		.rpc_resp = &data->res,
+	};
+	struct rpc_task_setup task_setup = {
+		.rpc_client = server->client,
+		.rpc_message = &msg,
+		.callback_ops = &nfs42_layoutstat_ops,
+		.callback_data = data,
+		.flags = RPC_TASK_ASYNC,
+	};
+	struct rpc_task *task;
+
+	data->inode = nfs_igrab_and_active(data->args.inode);
+	if (!data->inode) {
+		nfs42_layoutstat_release(data);
+		return -EAGAIN;
+	}
+	nfs4_init_sequence(&data->args.seq_args, &data->res.seq_res, 0, 0);
+	task = rpc_run_task(&task_setup);
+	if (IS_ERR(task))
+		return PTR_ERR(task);
+	rpc_put_task(task);
+	return 0;
+}
+
+static struct nfs42_layouterror_data *
+nfs42_alloc_layouterror_data(struct pnfs_layout_segment *lseg, gfp_t gfp_flags)
+{
+	struct nfs42_layouterror_data *data;
+	struct inode *inode = lseg->pls_layout->plh_inode;
+
+	data = kzalloc(sizeof(*data), gfp_flags);
+	if (data) {
+		data->args.inode = data->inode = nfs_igrab_and_active(inode);
+		if (data->inode) {
+			data->lseg = pnfs_get_lseg(lseg);
+			if (data->lseg)
+				return data;
+			nfs_iput_and_deactive(data->inode);
+		}
+		kfree(data);
+	}
+	return NULL;
+}
+
+static void
+nfs42_free_layouterror_data(struct nfs42_layouterror_data *data)
+{
+	pnfs_put_lseg(data->lseg);
+	nfs_iput_and_deactive(data->inode);
+	kfree(data);
+}
+
+static void
+nfs42_layouterror_prepare(struct rpc_task *task, void *calldata)
+{
+	struct nfs42_layouterror_data *data = calldata;
+	struct inode *inode = data->inode;
+	struct nfs_server *server = NFS_SERVER(inode);
+	struct pnfs_layout_hdr *lo = data->lseg->pls_layout;
+	unsigned i;
+
+	spin_lock(&inode->i_lock);
+	if (!pnfs_layout_is_valid(lo)) {
+		spin_unlock(&inode->i_lock);
+		rpc_exit(task, 0);
+		return;
+	}
+	for (i = 0; i < data->args.num_errors; i++)
+		nfs4_stateid_copy(&data->args.errors[i].stateid,
+				&lo->plh_stateid);
+	spin_unlock(&inode->i_lock);
+	nfs4_setup_sequence(server->nfs_client, &data->args.seq_args,
+			    &data->res.seq_res, task);
+}
+
+static void
+nfs42_layouterror_done(struct rpc_task *task, void *calldata)
+{
+	struct nfs42_layouterror_data *data = calldata;
+	struct inode *inode = data->inode;
+	struct pnfs_layout_hdr *lo = data->lseg->pls_layout;
+
+	if (!nfs4_sequence_done(task, &data->res.seq_res))
+		return;
+
+	switch (task->tk_status) {
+	case 0:
+		return;
+	case -NFS4ERR_BADHANDLE:
+	case -ESTALE:
+		pnfs_destroy_layout(NFS_I(inode));
+		break;
+	case -NFS4ERR_EXPIRED:
+	case -NFS4ERR_ADMIN_REVOKED:
+	case -NFS4ERR_DELEG_REVOKED:
+	case -NFS4ERR_STALE_STATEID:
+	case -NFS4ERR_BAD_STATEID:
+		spin_lock(&inode->i_lock);
+		if (pnfs_layout_is_valid(lo) &&
+		    nfs4_stateid_match(&data->args.errors[0].stateid,
+					     &lo->plh_stateid)) {
+			LIST_HEAD(head);
+
+			/*
+			 * Mark the bad layout state as invalid, then retry
+			 * with the current stateid.
+			 */
+			pnfs_mark_layout_stateid_invalid(lo, &head);
+			spin_unlock(&inode->i_lock);
+			pnfs_free_lseg_list(&head);
+			nfs_commit_inode(inode, 0);
+		} else
+			spin_unlock(&inode->i_lock);
+		break;
+	case -NFS4ERR_OLD_STATEID:
+		spin_lock(&inode->i_lock);
+		if (pnfs_layout_is_valid(lo) &&
+		    nfs4_stateid_match_other(&data->args.errors[0].stateid,
+					&lo->plh_stateid)) {
+			/* Do we need to delay before resending? */
+			if (!nfs4_stateid_is_newer(&lo->plh_stateid,
+						&data->args.errors[0].stateid))
+				rpc_delay(task, HZ);
+			rpc_restart_call_prepare(task);
+		}
+		spin_unlock(&inode->i_lock);
+		break;
+	case -ENOTSUPP:
+	case -EOPNOTSUPP:
+		NFS_SERVER(inode)->caps &= ~NFS_CAP_LAYOUTERROR;
+	}
+
+	trace_nfs4_layouterror(inode, &data->args.errors[0].stateid,
+			       task->tk_status);
+}
+
+static void
+nfs42_layouterror_release(void *calldata)
+{
+	struct nfs42_layouterror_data *data = calldata;
+
+	nfs42_free_layouterror_data(data);
+}
+
+static const struct rpc_call_ops nfs42_layouterror_ops = {
+	.rpc_call_prepare = nfs42_layouterror_prepare,
+	.rpc_call_done = nfs42_layouterror_done,
+	.rpc_release = nfs42_layouterror_release,
+};
+
+int nfs42_proc_layouterror(struct pnfs_layout_segment *lseg,
+		const struct nfs42_layout_error *errors, size_t n)
+{
+	struct inode *inode = lseg->pls_layout->plh_inode;
+	struct nfs42_layouterror_data *data;
+	struct rpc_task *task;
+	struct rpc_message msg = {
+		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_LAYOUTERROR],
+	};
+	struct rpc_task_setup task_setup = {
+		.rpc_message = &msg,
+		.callback_ops = &nfs42_layouterror_ops,
+		.flags = RPC_TASK_ASYNC,
+	};
+	unsigned int i;
+
+	if (!nfs_server_capable(inode, NFS_CAP_LAYOUTERROR))
+		return -EOPNOTSUPP;
+	if (n > NFS42_LAYOUTERROR_MAX)
+		return -EINVAL;
+	data = nfs42_alloc_layouterror_data(lseg, GFP_NOFS);
+	if (!data)
+		return -ENOMEM;
+	for (i = 0; i < n; i++) {
+		data->args.errors[i] = errors[i];
+		data->args.num_errors++;
+		data->res.num_errors++;
+	}
+	msg.rpc_argp = &data->args;
+	msg.rpc_resp = &data->res;
+	task_setup.callback_data = data;
+	task_setup.rpc_client = NFS_SERVER(inode)->client;
+	nfs4_init_sequence(&data->args.seq_args, &data->res.seq_res, 0, 0);
+	task = rpc_run_task(&task_setup);
+	if (IS_ERR(task))
+		return PTR_ERR(task);
+	rpc_put_task(task);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nfs42_proc_layouterror);
+
+static int _nfs42_proc_clone(struct rpc_message *msg, struct file *src_f,
+		struct file *dst_f, struct nfs_lock_context *src_lock,
+		struct nfs_lock_context *dst_lock, loff_t src_offset,
+		loff_t dst_offset, loff_t count)
+{
+	struct inode *src_inode = file_inode(src_f);
+	struct inode *dst_inode = file_inode(dst_f);
+	struct nfs_server *server = NFS_SERVER(dst_inode);
+	struct nfs42_clone_args args = {
+		.src_fh = NFS_FH(src_inode),
+		.dst_fh = NFS_FH(dst_inode),
+		.src_offset = src_offset,
+		.dst_offset = dst_offset,
+		.count = count,
+		.dst_bitmask = server->cache_consistency_bitmask,
+	};
+	struct nfs42_clone_res res = {
+		.server	= server,
+	};
+	int status;
+
+	msg->rpc_argp = &args;
+	msg->rpc_resp = &res;
+
+	status = nfs4_set_rw_stateid(&args.src_stateid, src_lock->open_context,
+			src_lock, FMODE_READ);
+	if (status) {
+		if (status == -EAGAIN)
+			status = -NFS4ERR_BAD_STATEID;
+		return status;
+	}
+	status = nfs4_set_rw_stateid(&args.dst_stateid, dst_lock->open_context,
+			dst_lock, FMODE_WRITE);
+	if (status) {
+		if (status == -EAGAIN)
+			status = -NFS4ERR_BAD_STATEID;
+		return status;
+	}
+
+	res.dst_fattr = nfs_alloc_fattr();
+	if (!res.dst_fattr)
+		return -ENOMEM;
+
+	status = nfs4_call_sync(server->client, server, msg,
+				&args.seq_args, &res.seq_res, 0);
+	if (status == 0)
+		status = nfs_post_op_update_inode(dst_inode, res.dst_fattr);
+
+	kfree(res.dst_fattr);
+	return status;
+}
+
+int nfs42_proc_clone(struct file *src_f, struct file *dst_f,
+		     loff_t src_offset, loff_t dst_offset, loff_t count)
+{
+	struct rpc_message msg = {
+		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_CLONE],
+	};
+	struct inode *inode = file_inode(src_f);
+	struct nfs_server *server = NFS_SERVER(file_inode(src_f));
+	struct nfs_lock_context *src_lock;
+	struct nfs_lock_context *dst_lock;
+	struct nfs4_exception src_exception = { };
+	struct nfs4_exception dst_exception = { };
+	int err, err2;
+
+	if (!nfs_server_capable(inode, NFS_CAP_CLONE))
+		return -EOPNOTSUPP;
+
+	src_lock = nfs_get_lock_context(nfs_file_open_context(src_f));
+	if (IS_ERR(src_lock))
+		return PTR_ERR(src_lock);
+
+	src_exception.inode = file_inode(src_f);
+	src_exception.state = src_lock->open_context->state;
+
+	dst_lock = nfs_get_lock_context(nfs_file_open_context(dst_f));
+	if (IS_ERR(dst_lock)) {
+		err = PTR_ERR(dst_lock);
+		goto out_put_src_lock;
+	}
+
+	dst_exception.inode = file_inode(dst_f);
+	dst_exception.state = dst_lock->open_context->state;
+
+	do {
+		err = _nfs42_proc_clone(&msg, src_f, dst_f, src_lock, dst_lock,
+					src_offset, dst_offset, count);
+		if (err == -ENOTSUPP || err == -EOPNOTSUPP) {
+			NFS_SERVER(inode)->caps &= ~NFS_CAP_CLONE;
+			err = -EOPNOTSUPP;
+			break;
+		}
+
+		err2 = nfs4_handle_exception(server, err, &src_exception);
+		err = nfs4_handle_exception(server, err, &dst_exception);
+		if (!err)
+			err = err2;
+	} while (src_exception.retry || dst_exception.retry);
+
+	nfs_put_lock_context(dst_lock);
+out_put_src_lock:
+	nfs_put_lock_context(src_lock);
+	return err;
+}
+
+#define NFS4XATTR_MAXPAGES DIV_ROUND_UP(XATTR_SIZE_MAX, PAGE_SIZE)
+
+static int _nfs42_proc_removexattr(struct inode *inode, const char *name)
+{
+	struct nfs_server *server = NFS_SERVER(inode);
+	struct nfs42_removexattrargs args = {
+		.fh = NFS_FH(inode),
+		.xattr_name = name,
+	};
+	struct nfs42_removexattrres res;
+	struct rpc_message msg = {
+		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_REMOVEXATTR],
+		.rpc_argp = &args,
+		.rpc_resp = &res,
+	};
+	int ret;
+	unsigned long timestamp = jiffies;
+
+	ret = nfs4_call_sync(server->client, server, &msg, &args.seq_args,
+	    &res.seq_res, 1);
+	if (!ret)
+		nfs4_update_changeattr(inode, &res.cinfo, timestamp, 0);
+
+	return ret;
+}
+
+static int _nfs42_proc_setxattr(struct inode *inode, const char *name,
+				const void *buf, size_t buflen, int flags)
+{
+	struct nfs_server *server = NFS_SERVER(inode);
+	struct page *pages[NFS4XATTR_MAXPAGES];
+	struct nfs42_setxattrargs arg = {
+		.fh		= NFS_FH(inode),
+		.xattr_pages	= pages,
+		.xattr_len	= buflen,
+		.xattr_name	= name,
+		.xattr_flags	= flags,
+	};
+	struct nfs42_setxattrres res;
+	struct rpc_message msg = {
+		.rpc_proc	= &nfs4_procedures[NFSPROC4_CLNT_SETXATTR],
+		.rpc_argp	= &arg,
+		.rpc_resp	= &res,
+	};
+	int ret, np;
+	unsigned long timestamp = jiffies;
+
+	if (buflen > server->sxasize)
+		return -ERANGE;
+
+	if (buflen > 0) {
+		np = nfs4_buf_to_pages_noslab(buf, buflen, arg.xattr_pages);
+		if (np < 0)
+			return np;
+	} else
+		np = 0;
+
+	ret = nfs4_call_sync(server->client, server, &msg, &arg.seq_args,
+	    &res.seq_res, 1);
+
+	for (; np > 0; np--)
+		put_page(pages[np - 1]);
+
+	if (!ret)
+		nfs4_update_changeattr(inode, &res.cinfo, timestamp, 0);
+
+	return ret;
+}
+
+static ssize_t _nfs42_proc_getxattr(struct inode *inode, const char *name,
+				void *buf, size_t buflen)
+{
+	struct nfs_server *server = NFS_SERVER(inode);
+	struct page *pages[NFS4XATTR_MAXPAGES] = {};
+	struct nfs42_getxattrargs arg = {
+		.fh		= NFS_FH(inode),
+		.xattr_pages	= pages,
+		.xattr_len	= buflen,
+		.xattr_name	= name,
+	};
+	struct nfs42_getxattrres res;
+	struct rpc_message msg = {
+		.rpc_proc	= &nfs4_procedures[NFSPROC4_CLNT_GETXATTR],
+		.rpc_argp	= &arg,
+		.rpc_resp	= &res,
+	};
+	int ret, np;
+
+	ret = nfs4_call_sync(server->client, server, &msg, &arg.seq_args,
+	    &res.seq_res, 0);
+	if (ret < 0)
+		return ret;
+
+	/*
+	 * Normally, the caching is done one layer up, but for successful
+	 * RPCS, always cache the result here, even if the caller was
+	 * just querying the length, or if the reply was too big for
+	 * the caller. This avoids a second RPC in the case of the
+	 * common query-alloc-retrieve cycle for xattrs.
+	 *
+	 * Note that xattr_len is always capped to XATTR_SIZE_MAX.
+	 */
+
+	nfs4_xattr_cache_add(inode, name, NULL, pages, res.xattr_len);
+
+	if (buflen) {
+		if (res.xattr_len > buflen)
+			return -ERANGE;
+		_copy_from_pages(buf, pages, 0, res.xattr_len);
+	}
+
+	np = DIV_ROUND_UP(res.xattr_len, PAGE_SIZE);
+	while (--np >= 0)
+		__free_page(pages[np]);
+
+	return res.xattr_len;
+}
+
+static ssize_t _nfs42_proc_listxattrs(struct inode *inode, void *buf,
+				 size_t buflen, u64 *cookiep, bool *eofp)
+{
+	struct nfs_server *server = NFS_SERVER(inode);
+	struct page **pages;
+	struct nfs42_listxattrsargs arg = {
+		.fh		= NFS_FH(inode),
+		.cookie		= *cookiep,
+	};
+	struct nfs42_listxattrsres res = {
+		.eof = false,
+		.xattr_buf = buf,
+		.xattr_len = buflen,
+	};
+	struct rpc_message msg = {
+		.rpc_proc	= &nfs4_procedures[NFSPROC4_CLNT_LISTXATTRS],
+		.rpc_argp	= &arg,
+		.rpc_resp	= &res,
+	};
+	u32 xdrlen;
+	int ret, np, i;
+
+
+	ret = -ENOMEM;
+	res.scratch = alloc_page(GFP_KERNEL);
+	if (!res.scratch)
+		goto out;
+
+	xdrlen = nfs42_listxattr_xdrsize(buflen);
+	if (xdrlen > server->lxasize)
+		xdrlen = server->lxasize;
+	np = xdrlen / PAGE_SIZE + 1;
+
+	pages = kcalloc(np, sizeof(struct page *), GFP_KERNEL);
+	if (!pages)
+		goto out_free_scratch;
+	for (i = 0; i < np; i++) {
+		pages[i] = alloc_page(GFP_KERNEL);
+		if (!pages[i])
+			goto out_free_pages;
+	}
+
+	arg.xattr_pages = pages;
+	arg.count = xdrlen;
+
+	ret = nfs4_call_sync(server->client, server, &msg, &arg.seq_args,
+	    &res.seq_res, 0);
+
+	if (ret >= 0) {
+		ret = res.copied;
+		*cookiep = res.cookie;
+		*eofp = res.eof;
+	}
+
+out_free_pages:
+	while (--np >= 0) {
+		if (pages[np])
+			__free_page(pages[np]);
+	}
+	kfree(pages);
+out_free_scratch:
+	__free_page(res.scratch);
+out:
+	return ret;
+
+}
+
+ssize_t nfs42_proc_getxattr(struct inode *inode, const char *name,
+			      void *buf, size_t buflen)
+{
+	struct nfs4_exception exception = { };
+	ssize_t err;
+
+	do {
+		err = _nfs42_proc_getxattr(inode, name, buf, buflen);
+		if (err >= 0)
+			break;
+		err = nfs4_handle_exception(NFS_SERVER(inode), err,
+				&exception);
+	} while (exception.retry);
+
+	return err;
+}
+
+int nfs42_proc_setxattr(struct inode *inode, const char *name,
+			      const void *buf, size_t buflen, int flags)
+{
+	struct nfs4_exception exception = { };
+	int err;
+
+	do {
+		err = _nfs42_proc_setxattr(inode, name, buf, buflen, flags);
+		if (!err)
+			break;
+		err = nfs4_handle_exception(NFS_SERVER(inode), err,
+				&exception);
+	} while (exception.retry);
+
+	return err;
+}
+
+ssize_t nfs42_proc_listxattrs(struct inode *inode, void *buf,
+			      size_t buflen, u64 *cookiep, bool *eofp)
+{
+	struct nfs4_exception exception = { };
+	ssize_t err;
+
+	do {
+		err = _nfs42_proc_listxattrs(inode, buf, buflen,
+		    cookiep, eofp);
+		if (err >= 0)
+			break;
+		err = nfs4_handle_exception(NFS_SERVER(inode), err,
+				&exception);
+	} while (exception.retry);
+
+	return err;
+}
+
+int nfs42_proc_removexattr(struct inode *inode, const char *name)
+{
+	struct nfs4_exception exception = { };
+	int err;
+
+	do {
+		err = _nfs42_proc_removexattr(inode, name);
+		if (!err)
+			break;
+		err = nfs4_handle_exception(NFS_SERVER(inode), err,
+				&exception);
+	} while (exception.retry);
+
+	return err;
+}
diff --git a/fs/nfs/nfs42xattr.c b/fs/nfs/nfs42xattr.c
new file mode 100644
index 000000000..6c2ce7991
--- /dev/null
+++ b/fs/nfs/nfs42xattr.c
@@ -0,0 +1,1057 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/*
+ * Copyright 2019, 2020 Amazon.com, Inc. or its affiliates. All rights reserved.
+ *
+ * User extended attribute client side cache functions.
+ *
+ * Author: Frank van der Linden <fllinden@amazon.com>
+ */
+#include <linux/errno.h>
+#include <linux/nfs_fs.h>
+#include <linux/hashtable.h>
+#include <linux/refcount.h>
+#include <uapi/linux/xattr.h>
+
+#include "nfs4_fs.h"
+#include "internal.h"
+
+/*
+ * User extended attributes client side caching is implemented by having
+ * a cache structure attached to NFS inodes. This structure is allocated
+ * when needed, and freed when the cache is zapped.
+ *
+ * The cache structure contains as hash table of entries, and a pointer
+ * to a special-cased entry for the listxattr cache.
+ *
+ * Accessing and allocating / freeing the caches is done via reference
+ * counting. The cache entries use a similar refcounting scheme.
+ *
+ * This makes freeing a cache, both from the shrinker and from the
+ * zap cache path, easy. It also means that, in current use cases,
+ * the large majority of inodes will not waste any memory, as they
+ * will never have any user extended attributes assigned to them.
+ *
+ * Attribute entries are hashed in to a simple hash table. They are
+ * also part of an LRU.
+ *
+ * There are three shrinkers.
+ *
+ * Two shrinkers deal with the cache entries themselves: one for
+ * large entries (> PAGE_SIZE), and one for smaller entries. The
+ * shrinker for the larger entries works more aggressively than
+ * those for the smaller entries.
+ *
+ * The other shrinker frees the cache structures themselves.
+ */
+
+/*
+ * 64 buckets is a good default. There is likely no reasonable
+ * workload that uses more than even 64 user extended attributes.
+ * You can certainly add a lot more - but you get what you ask for
+ * in those circumstances.
+ */
+#define NFS4_XATTR_HASH_SIZE	64
+
+#define NFSDBG_FACILITY	NFSDBG_XATTRCACHE
+
+struct nfs4_xattr_cache;
+struct nfs4_xattr_entry;
+
+struct nfs4_xattr_bucket {
+	spinlock_t lock;
+	struct hlist_head hlist;
+	struct nfs4_xattr_cache *cache;
+	bool draining;
+};
+
+struct nfs4_xattr_cache {
+	struct kref ref;
+	struct nfs4_xattr_bucket buckets[NFS4_XATTR_HASH_SIZE];
+	struct list_head lru;
+	struct list_head dispose;
+	atomic_long_t nent;
+	spinlock_t listxattr_lock;
+	struct inode *inode;
+	struct nfs4_xattr_entry *listxattr;
+};
+
+struct nfs4_xattr_entry {
+	struct kref ref;
+	struct hlist_node hnode;
+	struct list_head lru;
+	struct list_head dispose;
+	char *xattr_name;
+	void *xattr_value;
+	size_t xattr_size;
+	struct nfs4_xattr_bucket *bucket;
+	uint32_t flags;
+};
+
+#define	NFS4_XATTR_ENTRY_EXTVAL	0x0001
+
+/*
+ * LRU list of NFS inodes that have xattr caches.
+ */
+static struct list_lru nfs4_xattr_cache_lru;
+static struct list_lru nfs4_xattr_entry_lru;
+static struct list_lru nfs4_xattr_large_entry_lru;
+
+static struct kmem_cache *nfs4_xattr_cache_cachep;
+
+/*
+ * Hashing helper functions.
+ */
+static void
+nfs4_xattr_hash_init(struct nfs4_xattr_cache *cache)
+{
+	unsigned int i;
+
+	for (i = 0; i < NFS4_XATTR_HASH_SIZE; i++) {
+		INIT_HLIST_HEAD(&cache->buckets[i].hlist);
+		spin_lock_init(&cache->buckets[i].lock);
+		cache->buckets[i].cache = cache;
+		cache->buckets[i].draining = false;
+	}
+}
+
+/*
+ * Locking order:
+ * 1. inode i_lock or bucket lock
+ * 2. list_lru lock (taken by list_lru_* functions)
+ */
+
+/*
+ * Wrapper functions to add a cache entry to the right LRU.
+ */
+static bool
+nfs4_xattr_entry_lru_add(struct nfs4_xattr_entry *entry)
+{
+	struct list_lru *lru;
+
+	lru = (entry->flags & NFS4_XATTR_ENTRY_EXTVAL) ?
+	    &nfs4_xattr_large_entry_lru : &nfs4_xattr_entry_lru;
+
+	return list_lru_add(lru, &entry->lru);
+}
+
+static bool
+nfs4_xattr_entry_lru_del(struct nfs4_xattr_entry *entry)
+{
+	struct list_lru *lru;
+
+	lru = (entry->flags & NFS4_XATTR_ENTRY_EXTVAL) ?
+	    &nfs4_xattr_large_entry_lru : &nfs4_xattr_entry_lru;
+
+	return list_lru_del(lru, &entry->lru);
+}
+
+/*
+ * This function allocates cache entries. They are the normal
+ * extended attribute name/value pairs, but may also be a listxattr
+ * cache. Those allocations use the same entry so that they can be
+ * treated as one by the memory shrinker.
+ *
+ * xattr cache entries are allocated together with names. If the
+ * value fits in to one page with the entry structure and the name,
+ * it will also be part of the same allocation (kmalloc). This is
+ * expected to be the vast majority of cases. Larger allocations
+ * have a value pointer that is allocated separately by kvmalloc.
+ *
+ * Parameters:
+ *
+ * @name:  Name of the extended attribute. NULL for listxattr cache
+ *         entry.
+ * @value: Value of attribute, or listxattr cache. NULL if the
+ *         value is to be copied from pages instead.
+ * @pages: Pages to copy the value from, if not NULL. Passed in to
+ *	   make it easier to copy the value after an RPC, even if
+ *	   the value will not be passed up to application (e.g.
+ *	   for a 'query' getxattr with NULL buffer).
+ * @len:   Length of the value. Can be 0 for zero-length attribues.
+ *         @value and @pages will be NULL if @len is 0.
+ */
+static struct nfs4_xattr_entry *
+nfs4_xattr_alloc_entry(const char *name, const void *value,
+		       struct page **pages, size_t len)
+{
+	struct nfs4_xattr_entry *entry;
+	void *valp;
+	char *namep;
+	size_t alloclen, slen;
+	char *buf;
+	uint32_t flags;
+
+	BUILD_BUG_ON(sizeof(struct nfs4_xattr_entry) +
+	    XATTR_NAME_MAX + 1 > PAGE_SIZE);
+
+	alloclen = sizeof(struct nfs4_xattr_entry);
+	if (name != NULL) {
+		slen = strlen(name) + 1;
+		alloclen += slen;
+	} else
+		slen = 0;
+
+	if (alloclen + len <= PAGE_SIZE) {
+		alloclen += len;
+		flags = 0;
+	} else {
+		flags = NFS4_XATTR_ENTRY_EXTVAL;
+	}
+
+	buf = kmalloc(alloclen, GFP_KERNEL_ACCOUNT | GFP_NOFS);
+	if (buf == NULL)
+		return NULL;
+	entry = (struct nfs4_xattr_entry *)buf;
+
+	if (name != NULL) {
+		namep = buf + sizeof(struct nfs4_xattr_entry);
+		memcpy(namep, name, slen);
+	} else {
+		namep = NULL;
+	}
+
+
+	if (flags & NFS4_XATTR_ENTRY_EXTVAL) {
+		valp = kvmalloc(len, GFP_KERNEL_ACCOUNT | GFP_NOFS);
+		if (valp == NULL) {
+			kfree(buf);
+			return NULL;
+		}
+	} else if (len != 0) {
+		valp = buf + sizeof(struct nfs4_xattr_entry) + slen;
+	} else
+		valp = NULL;
+
+	if (valp != NULL) {
+		if (value != NULL)
+			memcpy(valp, value, len);
+		else
+			_copy_from_pages(valp, pages, 0, len);
+	}
+
+	entry->flags = flags;
+	entry->xattr_value = valp;
+	kref_init(&entry->ref);
+	entry->xattr_name = namep;
+	entry->xattr_size = len;
+	entry->bucket = NULL;
+	INIT_LIST_HEAD(&entry->lru);
+	INIT_LIST_HEAD(&entry->dispose);
+	INIT_HLIST_NODE(&entry->hnode);
+
+	return entry;
+}
+
+static void
+nfs4_xattr_free_entry(struct nfs4_xattr_entry *entry)
+{
+	if (entry->flags & NFS4_XATTR_ENTRY_EXTVAL)
+		kvfree(entry->xattr_value);
+	kfree(entry);
+}
+
+static void
+nfs4_xattr_free_entry_cb(struct kref *kref)
+{
+	struct nfs4_xattr_entry *entry;
+
+	entry = container_of(kref, struct nfs4_xattr_entry, ref);
+
+	if (WARN_ON(!list_empty(&entry->lru)))
+		return;
+
+	nfs4_xattr_free_entry(entry);
+}
+
+static void
+nfs4_xattr_free_cache_cb(struct kref *kref)
+{
+	struct nfs4_xattr_cache *cache;
+	int i;
+
+	cache = container_of(kref, struct nfs4_xattr_cache, ref);
+
+	for (i = 0; i < NFS4_XATTR_HASH_SIZE; i++) {
+		if (WARN_ON(!hlist_empty(&cache->buckets[i].hlist)))
+			return;
+		cache->buckets[i].draining = false;
+	}
+
+	cache->listxattr = NULL;
+
+	kmem_cache_free(nfs4_xattr_cache_cachep, cache);
+
+}
+
+static struct nfs4_xattr_cache *
+nfs4_xattr_alloc_cache(void)
+{
+	struct nfs4_xattr_cache *cache;
+
+	cache = kmem_cache_alloc(nfs4_xattr_cache_cachep,
+	    GFP_KERNEL_ACCOUNT | GFP_NOFS);
+	if (cache == NULL)
+		return NULL;
+
+	kref_init(&cache->ref);
+	atomic_long_set(&cache->nent, 0);
+
+	return cache;
+}
+
+/*
+ * Set the listxattr cache, which is a special-cased cache entry.
+ * The special value ERR_PTR(-ESTALE) is used to indicate that
+ * the cache is being drained - this prevents a new listxattr
+ * cache from being added to what is now a stale cache.
+ */
+static int
+nfs4_xattr_set_listcache(struct nfs4_xattr_cache *cache,
+			 struct nfs4_xattr_entry *new)
+{
+	struct nfs4_xattr_entry *old;
+	int ret = 1;
+
+	spin_lock(&cache->listxattr_lock);
+
+	old = cache->listxattr;
+
+	if (old == ERR_PTR(-ESTALE)) {
+		ret = 0;
+		goto out;
+	}
+
+	cache->listxattr = new;
+	if (new != NULL && new != ERR_PTR(-ESTALE))
+		nfs4_xattr_entry_lru_add(new);
+
+	if (old != NULL) {
+		nfs4_xattr_entry_lru_del(old);
+		kref_put(&old->ref, nfs4_xattr_free_entry_cb);
+	}
+out:
+	spin_unlock(&cache->listxattr_lock);
+
+	return ret;
+}
+
+/*
+ * Unlink a cache from its parent inode, clearing out an invalid
+ * cache. Must be called with i_lock held.
+ */
+static struct nfs4_xattr_cache *
+nfs4_xattr_cache_unlink(struct inode *inode)
+{
+	struct nfs_inode *nfsi;
+	struct nfs4_xattr_cache *oldcache;
+
+	nfsi = NFS_I(inode);
+
+	oldcache = nfsi->xattr_cache;
+	if (oldcache != NULL) {
+		list_lru_del(&nfs4_xattr_cache_lru, &oldcache->lru);
+		oldcache->inode = NULL;
+	}
+	nfsi->xattr_cache = NULL;
+	nfsi->cache_validity &= ~NFS_INO_INVALID_XATTR;
+
+	return oldcache;
+
+}
+
+/*
+ * Discard a cache. Called by get_cache() if there was an old,
+ * invalid cache. Can also be called from a shrinker callback.
+ *
+ * The cache is dead, it has already been unlinked from its inode,
+ * and no longer appears on the cache LRU list.
+ *
+ * Mark all buckets as draining, so that no new entries are added. This
+ * could still happen in the unlikely, but possible case that another
+ * thread had grabbed a reference before it was unlinked from the inode,
+ * and is still holding it for an add operation.
+ *
+ * Remove all entries from the LRU lists, so that there is no longer
+ * any way to 'find' this cache. Then, remove the entries from the hash
+ * table.
+ *
+ * At that point, the cache will remain empty and can be freed when the final
+ * reference drops, which is very likely the kref_put at the end of
+ * this function, or the one called immediately afterwards in the
+ * shrinker callback.
+ */
+static void
+nfs4_xattr_discard_cache(struct nfs4_xattr_cache *cache)
+{
+	unsigned int i;
+	struct nfs4_xattr_entry *entry;
+	struct nfs4_xattr_bucket *bucket;
+	struct hlist_node *n;
+
+	nfs4_xattr_set_listcache(cache, ERR_PTR(-ESTALE));
+
+	for (i = 0; i < NFS4_XATTR_HASH_SIZE; i++) {
+		bucket = &cache->buckets[i];
+
+		spin_lock(&bucket->lock);
+		bucket->draining = true;
+		hlist_for_each_entry_safe(entry, n, &bucket->hlist, hnode) {
+			nfs4_xattr_entry_lru_del(entry);
+			hlist_del_init(&entry->hnode);
+			kref_put(&entry->ref, nfs4_xattr_free_entry_cb);
+		}
+		spin_unlock(&bucket->lock);
+	}
+
+	atomic_long_set(&cache->nent, 0);
+
+	kref_put(&cache->ref, nfs4_xattr_free_cache_cb);
+}
+
+/*
+ * Get a referenced copy of the cache structure. Avoid doing allocs
+ * while holding i_lock. Which means that we do some optimistic allocation,
+ * and might have to free the result in rare cases.
+ *
+ * This function only checks the NFS_INO_INVALID_XATTR cache validity bit
+ * and acts accordingly, replacing the cache when needed. For the read case
+ * (!add), this means that the caller must make sure that the cache
+ * is valid before caling this function. getxattr and listxattr call
+ * revalidate_inode to do this. The attribute cache timeout (for the
+ * non-delegated case) is expected to be dealt with in the revalidate
+ * call.
+ */
+
+static struct nfs4_xattr_cache *
+nfs4_xattr_get_cache(struct inode *inode, int add)
+{
+	struct nfs_inode *nfsi;
+	struct nfs4_xattr_cache *cache, *oldcache, *newcache;
+
+	nfsi = NFS_I(inode);
+
+	cache = oldcache = NULL;
+
+	spin_lock(&inode->i_lock);
+
+	if (nfsi->cache_validity & NFS_INO_INVALID_XATTR)
+		oldcache = nfs4_xattr_cache_unlink(inode);
+	else
+		cache = nfsi->xattr_cache;
+
+	if (cache != NULL)
+		kref_get(&cache->ref);
+
+	spin_unlock(&inode->i_lock);
+
+	if (add && cache == NULL) {
+		newcache = NULL;
+
+		cache = nfs4_xattr_alloc_cache();
+		if (cache == NULL)
+			goto out;
+
+		spin_lock(&inode->i_lock);
+		if (nfsi->cache_validity & NFS_INO_INVALID_XATTR) {
+			/*
+			 * The cache was invalidated again. Give up,
+			 * since what we want to enter is now likely
+			 * outdated anyway.
+			 */
+			spin_unlock(&inode->i_lock);
+			kref_put(&cache->ref, nfs4_xattr_free_cache_cb);
+			cache = NULL;
+			goto out;
+		}
+
+		/*
+		 * Check if someone beat us to it.
+		 */
+		if (nfsi->xattr_cache != NULL) {
+			newcache = nfsi->xattr_cache;
+			kref_get(&newcache->ref);
+		} else {
+			kref_get(&cache->ref);
+			nfsi->xattr_cache = cache;
+			cache->inode = inode;
+			list_lru_add(&nfs4_xattr_cache_lru, &cache->lru);
+		}
+
+		spin_unlock(&inode->i_lock);
+
+		/*
+		 * If there was a race, throw away the cache we just
+		 * allocated, and use the new one allocated by someone
+		 * else.
+		 */
+		if (newcache != NULL) {
+			kref_put(&cache->ref, nfs4_xattr_free_cache_cb);
+			cache = newcache;
+		}
+	}
+
+out:
+	/*
+	 * Discard the now orphaned old cache.
+	 */
+	if (oldcache != NULL)
+		nfs4_xattr_discard_cache(oldcache);
+
+	return cache;
+}
+
+static inline struct nfs4_xattr_bucket *
+nfs4_xattr_hash_bucket(struct nfs4_xattr_cache *cache, const char *name)
+{
+	return &cache->buckets[jhash(name, strlen(name), 0) &
+	    (ARRAY_SIZE(cache->buckets) - 1)];
+}
+
+static struct nfs4_xattr_entry *
+nfs4_xattr_get_entry(struct nfs4_xattr_bucket *bucket, const char *name)
+{
+	struct nfs4_xattr_entry *entry;
+
+	entry = NULL;
+
+	hlist_for_each_entry(entry, &bucket->hlist, hnode) {
+		if (!strcmp(entry->xattr_name, name))
+			break;
+	}
+
+	return entry;
+}
+
+static int
+nfs4_xattr_hash_add(struct nfs4_xattr_cache *cache,
+		    struct nfs4_xattr_entry *entry)
+{
+	struct nfs4_xattr_bucket *bucket;
+	struct nfs4_xattr_entry *oldentry = NULL;
+	int ret = 1;
+
+	bucket = nfs4_xattr_hash_bucket(cache, entry->xattr_name);
+	entry->bucket = bucket;
+
+	spin_lock(&bucket->lock);
+
+	if (bucket->draining) {
+		ret = 0;
+		goto out;
+	}
+
+	oldentry = nfs4_xattr_get_entry(bucket, entry->xattr_name);
+	if (oldentry != NULL) {
+		hlist_del_init(&oldentry->hnode);
+		nfs4_xattr_entry_lru_del(oldentry);
+	} else {
+		atomic_long_inc(&cache->nent);
+	}
+
+	hlist_add_head(&entry->hnode, &bucket->hlist);
+	nfs4_xattr_entry_lru_add(entry);
+
+out:
+	spin_unlock(&bucket->lock);
+
+	if (oldentry != NULL)
+		kref_put(&oldentry->ref, nfs4_xattr_free_entry_cb);
+
+	return ret;
+}
+
+static void
+nfs4_xattr_hash_remove(struct nfs4_xattr_cache *cache, const char *name)
+{
+	struct nfs4_xattr_bucket *bucket;
+	struct nfs4_xattr_entry *entry;
+
+	bucket = nfs4_xattr_hash_bucket(cache, name);
+
+	spin_lock(&bucket->lock);
+
+	entry = nfs4_xattr_get_entry(bucket, name);
+	if (entry != NULL) {
+		hlist_del_init(&entry->hnode);
+		nfs4_xattr_entry_lru_del(entry);
+		atomic_long_dec(&cache->nent);
+	}
+
+	spin_unlock(&bucket->lock);
+
+	if (entry != NULL)
+		kref_put(&entry->ref, nfs4_xattr_free_entry_cb);
+}
+
+static struct nfs4_xattr_entry *
+nfs4_xattr_hash_find(struct nfs4_xattr_cache *cache, const char *name)
+{
+	struct nfs4_xattr_bucket *bucket;
+	struct nfs4_xattr_entry *entry;
+
+	bucket = nfs4_xattr_hash_bucket(cache, name);
+
+	spin_lock(&bucket->lock);
+
+	entry = nfs4_xattr_get_entry(bucket, name);
+	if (entry != NULL)
+		kref_get(&entry->ref);
+
+	spin_unlock(&bucket->lock);
+
+	return entry;
+}
+
+/*
+ * Entry point to retrieve an entry from the cache.
+ */
+ssize_t nfs4_xattr_cache_get(struct inode *inode, const char *name, char *buf,
+			 ssize_t buflen)
+{
+	struct nfs4_xattr_cache *cache;
+	struct nfs4_xattr_entry *entry;
+	ssize_t ret;
+
+	cache = nfs4_xattr_get_cache(inode, 0);
+	if (cache == NULL)
+		return -ENOENT;
+
+	ret = 0;
+	entry = nfs4_xattr_hash_find(cache, name);
+
+	if (entry != NULL) {
+		dprintk("%s: cache hit '%s', len %lu\n", __func__,
+		    entry->xattr_name, (unsigned long)entry->xattr_size);
+		if (buflen == 0) {
+			/* Length probe only */
+			ret = entry->xattr_size;
+		} else if (buflen < entry->xattr_size)
+			ret = -ERANGE;
+		else {
+			memcpy(buf, entry->xattr_value, entry->xattr_size);
+			ret = entry->xattr_size;
+		}
+		kref_put(&entry->ref, nfs4_xattr_free_entry_cb);
+	} else {
+		dprintk("%s: cache miss '%s'\n", __func__, name);
+		ret = -ENOENT;
+	}
+
+	kref_put(&cache->ref, nfs4_xattr_free_cache_cb);
+
+	return ret;
+}
+
+/*
+ * Retrieve a cached list of xattrs from the cache.
+ */
+ssize_t nfs4_xattr_cache_list(struct inode *inode, char *buf, ssize_t buflen)
+{
+	struct nfs4_xattr_cache *cache;
+	struct nfs4_xattr_entry *entry;
+	ssize_t ret;
+
+	cache = nfs4_xattr_get_cache(inode, 0);
+	if (cache == NULL)
+		return -ENOENT;
+
+	spin_lock(&cache->listxattr_lock);
+
+	entry = cache->listxattr;
+
+	if (entry != NULL && entry != ERR_PTR(-ESTALE)) {
+		if (buflen == 0) {
+			/* Length probe only */
+			ret = entry->xattr_size;
+		} else if (entry->xattr_size > buflen)
+			ret = -ERANGE;
+		else {
+			memcpy(buf, entry->xattr_value, entry->xattr_size);
+			ret = entry->xattr_size;
+		}
+	} else {
+		ret = -ENOENT;
+	}
+
+	spin_unlock(&cache->listxattr_lock);
+
+	kref_put(&cache->ref, nfs4_xattr_free_cache_cb);
+
+	return ret;
+}
+
+/*
+ * Add an xattr to the cache.
+ *
+ * This also invalidates the xattr list cache.
+ */
+void nfs4_xattr_cache_add(struct inode *inode, const char *name,
+			  const char *buf, struct page **pages, ssize_t buflen)
+{
+	struct nfs4_xattr_cache *cache;
+	struct nfs4_xattr_entry *entry;
+
+	dprintk("%s: add '%s' len %lu\n", __func__,
+	    name, (unsigned long)buflen);
+
+	cache = nfs4_xattr_get_cache(inode, 1);
+	if (cache == NULL)
+		return;
+
+	entry = nfs4_xattr_alloc_entry(name, buf, pages, buflen);
+	if (entry == NULL)
+		goto out;
+
+	(void)nfs4_xattr_set_listcache(cache, NULL);
+
+	if (!nfs4_xattr_hash_add(cache, entry))
+		kref_put(&entry->ref, nfs4_xattr_free_entry_cb);
+
+out:
+	kref_put(&cache->ref, nfs4_xattr_free_cache_cb);
+}
+
+
+/*
+ * Remove an xattr from the cache.
+ *
+ * This also invalidates the xattr list cache.
+ */
+void nfs4_xattr_cache_remove(struct inode *inode, const char *name)
+{
+	struct nfs4_xattr_cache *cache;
+
+	dprintk("%s: remove '%s'\n", __func__, name);
+
+	cache = nfs4_xattr_get_cache(inode, 0);
+	if (cache == NULL)
+		return;
+
+	(void)nfs4_xattr_set_listcache(cache, NULL);
+	nfs4_xattr_hash_remove(cache, name);
+
+	kref_put(&cache->ref, nfs4_xattr_free_cache_cb);
+}
+
+/*
+ * Cache listxattr output, replacing any possible old one.
+ */
+void nfs4_xattr_cache_set_list(struct inode *inode, const char *buf,
+			       ssize_t buflen)
+{
+	struct nfs4_xattr_cache *cache;
+	struct nfs4_xattr_entry *entry;
+
+	cache = nfs4_xattr_get_cache(inode, 1);
+	if (cache == NULL)
+		return;
+
+	entry = nfs4_xattr_alloc_entry(NULL, buf, NULL, buflen);
+	if (entry == NULL)
+		goto out;
+
+	/*
+	 * This is just there to be able to get to bucket->cache,
+	 * which is obviously the same for all buckets, so just
+	 * use bucket 0.
+	 */
+	entry->bucket = &cache->buckets[0];
+
+	if (!nfs4_xattr_set_listcache(cache, entry))
+		kref_put(&entry->ref, nfs4_xattr_free_entry_cb);
+
+out:
+	kref_put(&cache->ref, nfs4_xattr_free_cache_cb);
+}
+
+/*
+ * Zap the entire cache. Called when an inode is evicted.
+ */
+void nfs4_xattr_cache_zap(struct inode *inode)
+{
+	struct nfs4_xattr_cache *oldcache;
+
+	spin_lock(&inode->i_lock);
+	oldcache = nfs4_xattr_cache_unlink(inode);
+	spin_unlock(&inode->i_lock);
+
+	if (oldcache)
+		nfs4_xattr_discard_cache(oldcache);
+}
+
+/*
+ * The entry LRU is shrunk more aggressively than the cache LRU,
+ * by settings @seeks to 1.
+ *
+ * Cache structures are freed only when they've become empty, after
+ * pruning all but one entry.
+ */
+
+static unsigned long nfs4_xattr_cache_count(struct shrinker *shrink,
+					    struct shrink_control *sc);
+static unsigned long nfs4_xattr_entry_count(struct shrinker *shrink,
+					    struct shrink_control *sc);
+static unsigned long nfs4_xattr_cache_scan(struct shrinker *shrink,
+					   struct shrink_control *sc);
+static unsigned long nfs4_xattr_entry_scan(struct shrinker *shrink,
+					   struct shrink_control *sc);
+
+static struct shrinker nfs4_xattr_cache_shrinker = {
+	.count_objects	= nfs4_xattr_cache_count,
+	.scan_objects	= nfs4_xattr_cache_scan,
+	.seeks		= DEFAULT_SEEKS,
+	.flags		= SHRINKER_MEMCG_AWARE,
+};
+
+static struct shrinker nfs4_xattr_entry_shrinker = {
+	.count_objects	= nfs4_xattr_entry_count,
+	.scan_objects	= nfs4_xattr_entry_scan,
+	.seeks		= DEFAULT_SEEKS,
+	.batch		= 512,
+	.flags		= SHRINKER_MEMCG_AWARE,
+};
+
+static struct shrinker nfs4_xattr_large_entry_shrinker = {
+	.count_objects	= nfs4_xattr_entry_count,
+	.scan_objects	= nfs4_xattr_entry_scan,
+	.seeks		= 1,
+	.batch		= 512,
+	.flags		= SHRINKER_MEMCG_AWARE,
+};
+
+static enum lru_status
+cache_lru_isolate(struct list_head *item,
+	struct list_lru_one *lru, spinlock_t *lru_lock, void *arg)
+{
+	struct list_head *dispose = arg;
+	struct inode *inode;
+	struct nfs4_xattr_cache *cache = container_of(item,
+	    struct nfs4_xattr_cache, lru);
+
+	if (atomic_long_read(&cache->nent) > 1)
+		return LRU_SKIP;
+
+	/*
+	 * If a cache structure is on the LRU list, we know that
+	 * its inode is valid. Try to lock it to break the link.
+	 * Since we're inverting the lock order here, only try.
+	 */
+	inode = cache->inode;
+
+	if (!spin_trylock(&inode->i_lock))
+		return LRU_SKIP;
+
+	kref_get(&cache->ref);
+
+	cache->inode = NULL;
+	NFS_I(inode)->xattr_cache = NULL;
+	NFS_I(inode)->cache_validity &= ~NFS_INO_INVALID_XATTR;
+	list_lru_isolate(lru, &cache->lru);
+
+	spin_unlock(&inode->i_lock);
+
+	list_add_tail(&cache->dispose, dispose);
+	return LRU_REMOVED;
+}
+
+static unsigned long
+nfs4_xattr_cache_scan(struct shrinker *shrink, struct shrink_control *sc)
+{
+	LIST_HEAD(dispose);
+	unsigned long freed;
+	struct nfs4_xattr_cache *cache;
+
+	freed = list_lru_shrink_walk(&nfs4_xattr_cache_lru, sc,
+	    cache_lru_isolate, &dispose);
+	while (!list_empty(&dispose)) {
+		cache = list_first_entry(&dispose, struct nfs4_xattr_cache,
+		    dispose);
+		list_del_init(&cache->dispose);
+		nfs4_xattr_discard_cache(cache);
+		kref_put(&cache->ref, nfs4_xattr_free_cache_cb);
+	}
+
+	return freed;
+}
+
+
+static unsigned long
+nfs4_xattr_cache_count(struct shrinker *shrink, struct shrink_control *sc)
+{
+	unsigned long count;
+
+	count = list_lru_shrink_count(&nfs4_xattr_cache_lru, sc);
+	return vfs_pressure_ratio(count);
+}
+
+static enum lru_status
+entry_lru_isolate(struct list_head *item,
+	struct list_lru_one *lru, spinlock_t *lru_lock, void *arg)
+{
+	struct list_head *dispose = arg;
+	struct nfs4_xattr_bucket *bucket;
+	struct nfs4_xattr_cache *cache;
+	struct nfs4_xattr_entry *entry = container_of(item,
+	    struct nfs4_xattr_entry, lru);
+
+	bucket = entry->bucket;
+	cache = bucket->cache;
+
+	/*
+	 * Unhook the entry from its parent (either a cache bucket
+	 * or a cache structure if it's a listxattr buf), so that
+	 * it's no longer found. Then add it to the isolate list,
+	 * to be freed later.
+	 *
+	 * In both cases, we're reverting lock order, so use
+	 * trylock and skip the entry if we can't get the lock.
+	 */
+	if (entry->xattr_name != NULL) {
+		/* Regular cache entry */
+		if (!spin_trylock(&bucket->lock))
+			return LRU_SKIP;
+
+		kref_get(&entry->ref);
+
+		hlist_del_init(&entry->hnode);
+		atomic_long_dec(&cache->nent);
+		list_lru_isolate(lru, &entry->lru);
+
+		spin_unlock(&bucket->lock);
+	} else {
+		/* Listxattr cache entry */
+		if (!spin_trylock(&cache->listxattr_lock))
+			return LRU_SKIP;
+
+		kref_get(&entry->ref);
+
+		cache->listxattr = NULL;
+		list_lru_isolate(lru, &entry->lru);
+
+		spin_unlock(&cache->listxattr_lock);
+	}
+
+	list_add_tail(&entry->dispose, dispose);
+	return LRU_REMOVED;
+}
+
+static unsigned long
+nfs4_xattr_entry_scan(struct shrinker *shrink, struct shrink_control *sc)
+{
+	LIST_HEAD(dispose);
+	unsigned long freed;
+	struct nfs4_xattr_entry *entry;
+	struct list_lru *lru;
+
+	lru = (shrink == &nfs4_xattr_large_entry_shrinker) ?
+	    &nfs4_xattr_large_entry_lru : &nfs4_xattr_entry_lru;
+
+	freed = list_lru_shrink_walk(lru, sc, entry_lru_isolate, &dispose);
+
+	while (!list_empty(&dispose)) {
+		entry = list_first_entry(&dispose, struct nfs4_xattr_entry,
+		    dispose);
+		list_del_init(&entry->dispose);
+
+		/*
+		 * Drop two references: the one that we just grabbed
+		 * in entry_lru_isolate, and the one that was set
+		 * when the entry was first allocated.
+		 */
+		kref_put(&entry->ref, nfs4_xattr_free_entry_cb);
+		kref_put(&entry->ref, nfs4_xattr_free_entry_cb);
+	}
+
+	return freed;
+}
+
+static unsigned long
+nfs4_xattr_entry_count(struct shrinker *shrink, struct shrink_control *sc)
+{
+	unsigned long count;
+	struct list_lru *lru;
+
+	lru = (shrink == &nfs4_xattr_large_entry_shrinker) ?
+	    &nfs4_xattr_large_entry_lru : &nfs4_xattr_entry_lru;
+
+	count = list_lru_shrink_count(lru, sc);
+	return vfs_pressure_ratio(count);
+}
+
+
+static void nfs4_xattr_cache_init_once(void *p)
+{
+	struct nfs4_xattr_cache *cache = (struct nfs4_xattr_cache *)p;
+
+	spin_lock_init(&cache->listxattr_lock);
+	atomic_long_set(&cache->nent, 0);
+	nfs4_xattr_hash_init(cache);
+	cache->listxattr = NULL;
+	INIT_LIST_HEAD(&cache->lru);
+	INIT_LIST_HEAD(&cache->dispose);
+}
+
+int __init nfs4_xattr_cache_init(void)
+{
+	int ret = 0;
+
+	nfs4_xattr_cache_cachep = kmem_cache_create("nfs4_xattr_cache_cache",
+	    sizeof(struct nfs4_xattr_cache), 0,
+	    (SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|SLAB_ACCOUNT),
+	    nfs4_xattr_cache_init_once);
+	if (nfs4_xattr_cache_cachep == NULL)
+		return -ENOMEM;
+
+	ret = list_lru_init_memcg(&nfs4_xattr_large_entry_lru,
+	    &nfs4_xattr_large_entry_shrinker);
+	if (ret)
+		goto out4;
+
+	ret = list_lru_init_memcg(&nfs4_xattr_entry_lru,
+	    &nfs4_xattr_entry_shrinker);
+	if (ret)
+		goto out3;
+
+	ret = list_lru_init_memcg(&nfs4_xattr_cache_lru,
+	    &nfs4_xattr_cache_shrinker);
+	if (ret)
+		goto out2;
+
+	ret = register_shrinker(&nfs4_xattr_cache_shrinker);
+	if (ret)
+		goto out1;
+
+	ret = register_shrinker(&nfs4_xattr_entry_shrinker);
+	if (ret)
+		goto out;
+
+	ret = register_shrinker(&nfs4_xattr_large_entry_shrinker);
+	if (!ret)
+		return 0;
+
+	unregister_shrinker(&nfs4_xattr_entry_shrinker);
+out:
+	unregister_shrinker(&nfs4_xattr_cache_shrinker);
+out1:
+	list_lru_destroy(&nfs4_xattr_cache_lru);
+out2:
+	list_lru_destroy(&nfs4_xattr_entry_lru);
+out3:
+	list_lru_destroy(&nfs4_xattr_large_entry_lru);
+out4:
+	kmem_cache_destroy(nfs4_xattr_cache_cachep);
+
+	return ret;
+}
+
+void nfs4_xattr_cache_exit(void)
+{
+	unregister_shrinker(&nfs4_xattr_large_entry_shrinker);
+	unregister_shrinker(&nfs4_xattr_entry_shrinker);
+	unregister_shrinker(&nfs4_xattr_cache_shrinker);
+	list_lru_destroy(&nfs4_xattr_large_entry_lru);
+	list_lru_destroy(&nfs4_xattr_entry_lru);
+	list_lru_destroy(&nfs4_xattr_cache_lru);
+	kmem_cache_destroy(nfs4_xattr_cache_cachep);
+}
diff --git a/fs/nfs/nfs42xdr.c b/fs/nfs/nfs42xdr.c
new file mode 100644
index 000000000..f2248d9d4
--- /dev/null
+++ b/fs/nfs/nfs42xdr.c
@@ -0,0 +1,1592 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2014 Anna Schumaker <Anna.Schumaker@Netapp.com>
+ */
+#ifndef __LINUX_FS_NFS_NFS4_2XDR_H
+#define __LINUX_FS_NFS_NFS4_2XDR_H
+
+#include "nfs42.h"
+
+#define encode_fallocate_maxsz		(encode_stateid_maxsz + \
+					 2 /* offset */ + \
+					 2 /* length */)
+#define NFS42_WRITE_RES_SIZE		(1 /* wr_callback_id size */ +\
+					 XDR_QUADLEN(NFS4_STATEID_SIZE) + \
+					 2 /* wr_count */ + \
+					 1 /* wr_committed */ + \
+					 XDR_QUADLEN(NFS4_VERIFIER_SIZE))
+#define encode_allocate_maxsz		(op_encode_hdr_maxsz + \
+					 encode_fallocate_maxsz)
+#define decode_allocate_maxsz		(op_decode_hdr_maxsz)
+#define encode_copy_maxsz		(op_encode_hdr_maxsz +          \
+					 XDR_QUADLEN(NFS4_STATEID_SIZE) + \
+					 XDR_QUADLEN(NFS4_STATEID_SIZE) + \
+					 2 + 2 + 2 + 1 + 1 + 1 +\
+					 1 + /* One cnr_source_server */\
+					 1 + /* nl4_type */ \
+					 1 + XDR_QUADLEN(NFS4_OPAQUE_LIMIT))
+#define decode_copy_maxsz		(op_decode_hdr_maxsz + \
+					 NFS42_WRITE_RES_SIZE + \
+					 1 /* cr_consecutive */ + \
+					 1 /* cr_synchronous */)
+#define encode_offload_cancel_maxsz	(op_encode_hdr_maxsz + \
+					 XDR_QUADLEN(NFS4_STATEID_SIZE))
+#define decode_offload_cancel_maxsz	(op_decode_hdr_maxsz)
+#define encode_copy_notify_maxsz	(op_encode_hdr_maxsz + \
+					 XDR_QUADLEN(NFS4_STATEID_SIZE) + \
+					 1 + /* nl4_type */ \
+					 1 + XDR_QUADLEN(NFS4_OPAQUE_LIMIT))
+#define decode_copy_notify_maxsz	(op_decode_hdr_maxsz + \
+					 3 + /* cnr_lease_time */\
+					 XDR_QUADLEN(NFS4_STATEID_SIZE) + \
+					 1 + /* Support 1 cnr_source_server */\
+					 1 + /* nl4_type */ \
+					 1 + XDR_QUADLEN(NFS4_OPAQUE_LIMIT))
+#define encode_deallocate_maxsz		(op_encode_hdr_maxsz + \
+					 encode_fallocate_maxsz)
+#define decode_deallocate_maxsz		(op_decode_hdr_maxsz)
+#define encode_read_plus_maxsz		(op_encode_hdr_maxsz + \
+					 encode_stateid_maxsz + 3)
+#define NFS42_READ_PLUS_SEGMENT_SIZE	(1 /* data_content4 */ + \
+					 2 /* data_info4.di_offset */ + \
+					 2 /* data_info4.di_length */)
+#define decode_read_plus_maxsz		(op_decode_hdr_maxsz + \
+					 1 /* rpr_eof */ + \
+					 1 /* rpr_contents count */ + \
+					 2 * NFS42_READ_PLUS_SEGMENT_SIZE)
+#define encode_seek_maxsz		(op_encode_hdr_maxsz + \
+					 encode_stateid_maxsz + \
+					 2 /* offset */ + \
+					 1 /* whence */)
+#define decode_seek_maxsz		(op_decode_hdr_maxsz + \
+					 1 /* eof */ + \
+					 1 /* whence */ + \
+					 2 /* offset */ + \
+					 2 /* length */)
+#define encode_io_info_maxsz		4
+#define encode_layoutstats_maxsz	(op_decode_hdr_maxsz + \
+					2 /* offset */ + \
+					2 /* length */ + \
+					encode_stateid_maxsz + \
+					encode_io_info_maxsz + \
+					encode_io_info_maxsz + \
+					1 /* opaque devaddr4 length */ + \
+					XDR_QUADLEN(PNFS_LAYOUTSTATS_MAXSIZE))
+#define decode_layoutstats_maxsz	(op_decode_hdr_maxsz)
+#define encode_device_error_maxsz	(XDR_QUADLEN(NFS4_DEVICEID4_SIZE) + \
+					1 /* status */ + 1 /* opnum */)
+#define encode_layouterror_maxsz	(op_decode_hdr_maxsz + \
+					2 /* offset */ + \
+					2 /* length */ + \
+					encode_stateid_maxsz + \
+					1 /* Array size */ + \
+					encode_device_error_maxsz)
+#define decode_layouterror_maxsz	(op_decode_hdr_maxsz)
+#define encode_clone_maxsz		(encode_stateid_maxsz + \
+					encode_stateid_maxsz + \
+					2 /* src offset */ + \
+					2 /* dst offset */ + \
+					2 /* count */)
+#define decode_clone_maxsz		(op_decode_hdr_maxsz)
+
+#define NFS4_enc_allocate_sz		(compound_encode_hdr_maxsz + \
+					 encode_sequence_maxsz + \
+					 encode_putfh_maxsz + \
+					 encode_allocate_maxsz + \
+					 encode_getattr_maxsz)
+#define NFS4_dec_allocate_sz		(compound_decode_hdr_maxsz + \
+					 decode_sequence_maxsz + \
+					 decode_putfh_maxsz + \
+					 decode_allocate_maxsz + \
+					 decode_getattr_maxsz)
+#define NFS4_enc_copy_sz		(compound_encode_hdr_maxsz + \
+					 encode_sequence_maxsz + \
+					 encode_putfh_maxsz + \
+					 encode_savefh_maxsz + \
+					 encode_putfh_maxsz + \
+					 encode_copy_maxsz + \
+					 encode_commit_maxsz)
+#define NFS4_dec_copy_sz		(compound_decode_hdr_maxsz + \
+					 decode_sequence_maxsz + \
+					 decode_putfh_maxsz + \
+					 decode_savefh_maxsz + \
+					 decode_putfh_maxsz + \
+					 decode_copy_maxsz + \
+					 decode_commit_maxsz)
+#define NFS4_enc_offload_cancel_sz	(compound_encode_hdr_maxsz + \
+					 encode_sequence_maxsz + \
+					 encode_putfh_maxsz + \
+					 encode_offload_cancel_maxsz)
+#define NFS4_dec_offload_cancel_sz	(compound_decode_hdr_maxsz + \
+					 decode_sequence_maxsz + \
+					 decode_putfh_maxsz + \
+					 decode_offload_cancel_maxsz)
+#define NFS4_enc_copy_notify_sz		(compound_encode_hdr_maxsz + \
+					 encode_putfh_maxsz + \
+					 encode_copy_notify_maxsz)
+#define NFS4_dec_copy_notify_sz		(compound_decode_hdr_maxsz + \
+					 decode_putfh_maxsz + \
+					 decode_copy_notify_maxsz)
+#define NFS4_enc_deallocate_sz		(compound_encode_hdr_maxsz + \
+					 encode_sequence_maxsz + \
+					 encode_putfh_maxsz + \
+					 encode_deallocate_maxsz + \
+					 encode_getattr_maxsz)
+#define NFS4_dec_deallocate_sz		(compound_decode_hdr_maxsz + \
+					 decode_sequence_maxsz + \
+					 decode_putfh_maxsz + \
+					 decode_deallocate_maxsz + \
+					 decode_getattr_maxsz)
+#define NFS4_enc_read_plus_sz		(compound_encode_hdr_maxsz + \
+					 encode_sequence_maxsz + \
+					 encode_putfh_maxsz + \
+					 encode_read_plus_maxsz)
+#define NFS4_dec_read_plus_sz		(compound_decode_hdr_maxsz + \
+					 decode_sequence_maxsz + \
+					 decode_putfh_maxsz + \
+					 decode_read_plus_maxsz)
+#define NFS4_enc_seek_sz		(compound_encode_hdr_maxsz + \
+					 encode_sequence_maxsz + \
+					 encode_putfh_maxsz + \
+					 encode_seek_maxsz)
+#define NFS4_dec_seek_sz		(compound_decode_hdr_maxsz + \
+					 decode_sequence_maxsz + \
+					 decode_putfh_maxsz + \
+					 decode_seek_maxsz)
+#define NFS4_enc_layoutstats_sz		(compound_encode_hdr_maxsz + \
+					 encode_sequence_maxsz + \
+					 encode_putfh_maxsz + \
+					 PNFS_LAYOUTSTATS_MAXDEV * encode_layoutstats_maxsz)
+#define NFS4_dec_layoutstats_sz		(compound_decode_hdr_maxsz + \
+					 decode_sequence_maxsz + \
+					 decode_putfh_maxsz + \
+					 PNFS_LAYOUTSTATS_MAXDEV * decode_layoutstats_maxsz)
+#define NFS4_enc_layouterror_sz		(compound_encode_hdr_maxsz + \
+					 encode_sequence_maxsz + \
+					 encode_putfh_maxsz + \
+					 NFS42_LAYOUTERROR_MAX * \
+					 encode_layouterror_maxsz)
+#define NFS4_dec_layouterror_sz		(compound_decode_hdr_maxsz + \
+					 decode_sequence_maxsz + \
+					 decode_putfh_maxsz + \
+					 NFS42_LAYOUTERROR_MAX * \
+					 decode_layouterror_maxsz)
+#define NFS4_enc_clone_sz		(compound_encode_hdr_maxsz + \
+					 encode_sequence_maxsz + \
+					 encode_putfh_maxsz + \
+					 encode_savefh_maxsz + \
+					 encode_putfh_maxsz + \
+					 encode_clone_maxsz + \
+					 encode_getattr_maxsz)
+#define NFS4_dec_clone_sz		(compound_decode_hdr_maxsz + \
+					 decode_sequence_maxsz + \
+					 decode_putfh_maxsz + \
+					 decode_savefh_maxsz + \
+					 decode_putfh_maxsz + \
+					 decode_clone_maxsz + \
+					 decode_getattr_maxsz)
+
+/* Not limited by NFS itself, limited by the generic xattr code */
+#define nfs4_xattr_name_maxsz   XDR_QUADLEN(XATTR_NAME_MAX)
+
+#define encode_getxattr_maxsz   (op_encode_hdr_maxsz + 1 + \
+				 nfs4_xattr_name_maxsz)
+#define decode_getxattr_maxsz   (op_decode_hdr_maxsz + 1 + 1)
+#define encode_setxattr_maxsz   (op_encode_hdr_maxsz + \
+				 1 + nfs4_xattr_name_maxsz + 1)
+#define decode_setxattr_maxsz   (op_decode_hdr_maxsz + decode_change_info_maxsz)
+#define encode_listxattrs_maxsz  (op_encode_hdr_maxsz + 2 + 1)
+#define decode_listxattrs_maxsz  (op_decode_hdr_maxsz + 2 + 1 + 1 + 1)
+#define encode_removexattr_maxsz (op_encode_hdr_maxsz + 1 + \
+				  nfs4_xattr_name_maxsz)
+#define decode_removexattr_maxsz (op_decode_hdr_maxsz + \
+				  decode_change_info_maxsz)
+
+#define NFS4_enc_getxattr_sz	(compound_encode_hdr_maxsz + \
+				encode_sequence_maxsz + \
+				encode_putfh_maxsz + \
+				encode_getxattr_maxsz)
+#define NFS4_dec_getxattr_sz	(compound_decode_hdr_maxsz + \
+				decode_sequence_maxsz + \
+				decode_putfh_maxsz + \
+				decode_getxattr_maxsz)
+#define NFS4_enc_setxattr_sz	(compound_encode_hdr_maxsz + \
+				encode_sequence_maxsz + \
+				encode_putfh_maxsz + \
+				encode_setxattr_maxsz)
+#define NFS4_dec_setxattr_sz	(compound_decode_hdr_maxsz + \
+				decode_sequence_maxsz + \
+				decode_putfh_maxsz + \
+				decode_setxattr_maxsz)
+#define NFS4_enc_listxattrs_sz	(compound_encode_hdr_maxsz + \
+				encode_sequence_maxsz + \
+				encode_putfh_maxsz + \
+				encode_listxattrs_maxsz)
+#define NFS4_dec_listxattrs_sz	(compound_decode_hdr_maxsz + \
+				decode_sequence_maxsz + \
+				decode_putfh_maxsz + \
+				decode_listxattrs_maxsz)
+#define NFS4_enc_removexattr_sz	(compound_encode_hdr_maxsz + \
+				encode_sequence_maxsz + \
+				encode_putfh_maxsz + \
+				encode_removexattr_maxsz)
+#define NFS4_dec_removexattr_sz	(compound_decode_hdr_maxsz + \
+				decode_sequence_maxsz + \
+				decode_putfh_maxsz + \
+				decode_removexattr_maxsz)
+
+/*
+ * These values specify the maximum amount of data that is not
+ * associated with the extended attribute name or extended
+ * attribute list in the SETXATTR, GETXATTR and LISTXATTR
+ * respectively.
+ */
+const u32 nfs42_maxsetxattr_overhead = ((RPC_MAX_HEADER_WITH_AUTH +
+					compound_encode_hdr_maxsz +
+					encode_sequence_maxsz +
+					encode_putfh_maxsz + 1 +
+					nfs4_xattr_name_maxsz)
+					* XDR_UNIT);
+
+const u32 nfs42_maxgetxattr_overhead = ((RPC_MAX_HEADER_WITH_AUTH +
+					compound_decode_hdr_maxsz +
+					decode_sequence_maxsz +
+					decode_putfh_maxsz + 1) * XDR_UNIT);
+
+const u32 nfs42_maxlistxattrs_overhead = ((RPC_MAX_HEADER_WITH_AUTH +
+					compound_decode_hdr_maxsz +
+					decode_sequence_maxsz +
+					decode_putfh_maxsz + 3) * XDR_UNIT);
+
+static void encode_fallocate(struct xdr_stream *xdr,
+			     const struct nfs42_falloc_args *args)
+{
+	encode_nfs4_stateid(xdr, &args->falloc_stateid);
+	encode_uint64(xdr, args->falloc_offset);
+	encode_uint64(xdr, args->falloc_length);
+}
+
+static void encode_allocate(struct xdr_stream *xdr,
+			    const struct nfs42_falloc_args *args,
+			    struct compound_hdr *hdr)
+{
+	encode_op_hdr(xdr, OP_ALLOCATE, decode_allocate_maxsz, hdr);
+	encode_fallocate(xdr, args);
+}
+
+static void encode_nl4_server(struct xdr_stream *xdr,
+			      const struct nl4_server *ns)
+{
+	encode_uint32(xdr, ns->nl4_type);
+	switch (ns->nl4_type) {
+	case NL4_NAME:
+	case NL4_URL:
+		encode_string(xdr, ns->u.nl4_str_sz, ns->u.nl4_str);
+		break;
+	case NL4_NETADDR:
+		encode_string(xdr, ns->u.nl4_addr.netid_len,
+			      ns->u.nl4_addr.netid);
+		encode_string(xdr, ns->u.nl4_addr.addr_len,
+			      ns->u.nl4_addr.addr);
+		break;
+	default:
+		WARN_ON_ONCE(1);
+	}
+}
+
+static void encode_copy(struct xdr_stream *xdr,
+			const struct nfs42_copy_args *args,
+			struct compound_hdr *hdr)
+{
+	encode_op_hdr(xdr, OP_COPY, decode_copy_maxsz, hdr);
+	encode_nfs4_stateid(xdr, &args->src_stateid);
+	encode_nfs4_stateid(xdr, &args->dst_stateid);
+
+	encode_uint64(xdr, args->src_pos);
+	encode_uint64(xdr, args->dst_pos);
+	encode_uint64(xdr, args->count);
+
+	encode_uint32(xdr, 1); /* consecutive = true */
+	encode_uint32(xdr, args->sync);
+	if (args->cp_src == NULL) { /* intra-ssc */
+		encode_uint32(xdr, 0); /* no src server list */
+		return;
+	}
+	encode_uint32(xdr, 1); /* supporting 1 server */
+	encode_nl4_server(xdr, args->cp_src);
+}
+
+static void encode_offload_cancel(struct xdr_stream *xdr,
+				  const struct nfs42_offload_status_args *args,
+				  struct compound_hdr *hdr)
+{
+	encode_op_hdr(xdr, OP_OFFLOAD_CANCEL, decode_offload_cancel_maxsz, hdr);
+	encode_nfs4_stateid(xdr, &args->osa_stateid);
+}
+
+static void encode_copy_notify(struct xdr_stream *xdr,
+			       const struct nfs42_copy_notify_args *args,
+			       struct compound_hdr *hdr)
+{
+	encode_op_hdr(xdr, OP_COPY_NOTIFY, decode_copy_notify_maxsz, hdr);
+	encode_nfs4_stateid(xdr, &args->cna_src_stateid);
+	encode_nl4_server(xdr, &args->cna_dst);
+}
+
+static void encode_deallocate(struct xdr_stream *xdr,
+			      const struct nfs42_falloc_args *args,
+			      struct compound_hdr *hdr)
+{
+	encode_op_hdr(xdr, OP_DEALLOCATE, decode_deallocate_maxsz, hdr);
+	encode_fallocate(xdr, args);
+}
+
+static void encode_read_plus(struct xdr_stream *xdr,
+			     const struct nfs_pgio_args *args,
+			     struct compound_hdr *hdr)
+{
+	encode_op_hdr(xdr, OP_READ_PLUS, decode_read_plus_maxsz, hdr);
+	encode_nfs4_stateid(xdr, &args->stateid);
+	encode_uint64(xdr, args->offset);
+	encode_uint32(xdr, args->count);
+}
+
+static void encode_seek(struct xdr_stream *xdr,
+			const struct nfs42_seek_args *args,
+			struct compound_hdr *hdr)
+{
+	encode_op_hdr(xdr, OP_SEEK, decode_seek_maxsz, hdr);
+	encode_nfs4_stateid(xdr, &args->sa_stateid);
+	encode_uint64(xdr, args->sa_offset);
+	encode_uint32(xdr, args->sa_what);
+}
+
+static void encode_layoutstats(struct xdr_stream *xdr,
+			       const struct nfs42_layoutstat_args *args,
+			       struct nfs42_layoutstat_devinfo *devinfo,
+			       struct compound_hdr *hdr)
+{
+	__be32 *p;
+
+	encode_op_hdr(xdr, OP_LAYOUTSTATS, decode_layoutstats_maxsz, hdr);
+	p = reserve_space(xdr, 8 + 8);
+	p = xdr_encode_hyper(p, devinfo->offset);
+	p = xdr_encode_hyper(p, devinfo->length);
+	encode_nfs4_stateid(xdr, &args->stateid);
+	p = reserve_space(xdr, 4*8 + NFS4_DEVICEID4_SIZE + 4);
+	p = xdr_encode_hyper(p, devinfo->read_count);
+	p = xdr_encode_hyper(p, devinfo->read_bytes);
+	p = xdr_encode_hyper(p, devinfo->write_count);
+	p = xdr_encode_hyper(p, devinfo->write_bytes);
+	p = xdr_encode_opaque_fixed(p, devinfo->dev_id.data,
+			NFS4_DEVICEID4_SIZE);
+	/* Encode layoutupdate4 */
+	*p++ = cpu_to_be32(devinfo->layout_type);
+	if (devinfo->ld_private.ops)
+		devinfo->ld_private.ops->encode(xdr, args,
+				&devinfo->ld_private);
+	else
+		encode_uint32(xdr, 0);
+}
+
+static void encode_clone(struct xdr_stream *xdr,
+			 const struct nfs42_clone_args *args,
+			 struct compound_hdr *hdr)
+{
+	__be32 *p;
+
+	encode_op_hdr(xdr, OP_CLONE, decode_clone_maxsz, hdr);
+	encode_nfs4_stateid(xdr, &args->src_stateid);
+	encode_nfs4_stateid(xdr, &args->dst_stateid);
+	p = reserve_space(xdr, 3*8);
+	p = xdr_encode_hyper(p, args->src_offset);
+	p = xdr_encode_hyper(p, args->dst_offset);
+	xdr_encode_hyper(p, args->count);
+}
+
+static void encode_device_error(struct xdr_stream *xdr,
+				const struct nfs42_device_error *error)
+{
+	__be32 *p;
+
+	p = reserve_space(xdr, NFS4_DEVICEID4_SIZE + 2*4);
+	p = xdr_encode_opaque_fixed(p, error->dev_id.data,
+			NFS4_DEVICEID4_SIZE);
+	*p++ = cpu_to_be32(error->status);
+	*p = cpu_to_be32(error->opnum);
+}
+
+static void encode_layouterror(struct xdr_stream *xdr,
+			       const struct nfs42_layout_error *args,
+			       struct compound_hdr *hdr)
+{
+	__be32 *p;
+
+	encode_op_hdr(xdr, OP_LAYOUTERROR, decode_layouterror_maxsz, hdr);
+	p = reserve_space(xdr, 8 + 8);
+	p = xdr_encode_hyper(p, args->offset);
+	p = xdr_encode_hyper(p, args->length);
+	encode_nfs4_stateid(xdr, &args->stateid);
+	p = reserve_space(xdr, 4);
+	*p = cpu_to_be32(1);
+	encode_device_error(xdr, &args->errors[0]);
+}
+
+static void encode_setxattr(struct xdr_stream *xdr,
+			    const struct nfs42_setxattrargs *arg,
+			    struct compound_hdr *hdr)
+{
+	__be32 *p;
+
+	BUILD_BUG_ON(XATTR_CREATE != SETXATTR4_CREATE);
+	BUILD_BUG_ON(XATTR_REPLACE != SETXATTR4_REPLACE);
+
+	encode_op_hdr(xdr, OP_SETXATTR, decode_setxattr_maxsz, hdr);
+	p = reserve_space(xdr, 4);
+	*p = cpu_to_be32(arg->xattr_flags);
+	encode_string(xdr, strlen(arg->xattr_name), arg->xattr_name);
+	p = reserve_space(xdr, 4);
+	*p = cpu_to_be32(arg->xattr_len);
+	if (arg->xattr_len)
+		xdr_write_pages(xdr, arg->xattr_pages, 0, arg->xattr_len);
+}
+
+static int decode_setxattr(struct xdr_stream *xdr,
+			   struct nfs4_change_info *cinfo)
+{
+	int status;
+
+	status = decode_op_hdr(xdr, OP_SETXATTR);
+	if (status)
+		goto out;
+	status = decode_change_info(xdr, cinfo);
+out:
+	return status;
+}
+
+
+static void encode_getxattr(struct xdr_stream *xdr, const char *name,
+			    struct compound_hdr *hdr)
+{
+	encode_op_hdr(xdr, OP_GETXATTR, decode_getxattr_maxsz, hdr);
+	encode_string(xdr, strlen(name), name);
+}
+
+static int decode_getxattr(struct xdr_stream *xdr,
+			   struct nfs42_getxattrres *res,
+			   struct rpc_rqst *req)
+{
+	int status;
+	__be32 *p;
+	u32 len, rdlen;
+
+	status = decode_op_hdr(xdr, OP_GETXATTR);
+	if (status)
+		return status;
+
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(!p))
+		return -EIO;
+
+	len = be32_to_cpup(p);
+	if (len > req->rq_rcv_buf.page_len)
+		return -ERANGE;
+
+	res->xattr_len = len;
+
+	if (len > 0) {
+		rdlen = xdr_read_pages(xdr, len);
+		if (rdlen < len)
+			return -EIO;
+	}
+
+	return 0;
+}
+
+static void encode_removexattr(struct xdr_stream *xdr, const char *name,
+			       struct compound_hdr *hdr)
+{
+	encode_op_hdr(xdr, OP_REMOVEXATTR, decode_removexattr_maxsz, hdr);
+	encode_string(xdr, strlen(name), name);
+}
+
+
+static int decode_removexattr(struct xdr_stream *xdr,
+			   struct nfs4_change_info *cinfo)
+{
+	int status;
+
+	status = decode_op_hdr(xdr, OP_REMOVEXATTR);
+	if (status)
+		goto out;
+
+	status = decode_change_info(xdr, cinfo);
+out:
+	return status;
+}
+
+static void encode_listxattrs(struct xdr_stream *xdr,
+			     const struct nfs42_listxattrsargs *arg,
+			     struct compound_hdr *hdr)
+{
+	__be32 *p;
+
+	encode_op_hdr(xdr, OP_LISTXATTRS, decode_listxattrs_maxsz, hdr);
+
+	p = reserve_space(xdr, 12);
+	if (unlikely(!p))
+		return;
+
+	p = xdr_encode_hyper(p, arg->cookie);
+	/*
+	 * RFC 8276 says to specify the full max length of the LISTXATTRS
+	 * XDR reply. Count is set to the XDR length of the names array
+	 * plus the EOF marker. So, add the cookie and the names count.
+	 */
+	*p = cpu_to_be32(arg->count + 8 + 4);
+}
+
+static int decode_listxattrs(struct xdr_stream *xdr,
+			    struct nfs42_listxattrsres *res)
+{
+	int status;
+	__be32 *p;
+	u32 count, len, ulen;
+	size_t left, copied;
+	char *buf;
+
+	status = decode_op_hdr(xdr, OP_LISTXATTRS);
+	if (status) {
+		/*
+		 * Special case: for LISTXATTRS, NFS4ERR_TOOSMALL
+		 * should be translated to ERANGE.
+		 */
+		if (status == -ETOOSMALL)
+			status = -ERANGE;
+		goto out;
+	}
+
+	p = xdr_inline_decode(xdr, 8);
+	if (unlikely(!p))
+		return -EIO;
+
+	xdr_decode_hyper(p, &res->cookie);
+
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(!p))
+		return -EIO;
+
+	left = res->xattr_len;
+	buf = res->xattr_buf;
+
+	count = be32_to_cpup(p);
+	copied = 0;
+
+	/*
+	 * We have asked for enough room to encode the maximum number
+	 * of possible attribute names, so everything should fit.
+	 *
+	 * But, don't rely on that assumption. Just decode entries
+	 * until they don't fit anymore, just in case the server did
+	 * something odd.
+	 */
+	while (count--) {
+		p = xdr_inline_decode(xdr, 4);
+		if (unlikely(!p))
+			return -EIO;
+
+		len = be32_to_cpup(p);
+		if (len > (XATTR_NAME_MAX - XATTR_USER_PREFIX_LEN)) {
+			status = -ERANGE;
+			goto out;
+		}
+
+		p = xdr_inline_decode(xdr, len);
+		if (unlikely(!p))
+			return -EIO;
+
+		ulen = len + XATTR_USER_PREFIX_LEN + 1;
+		if (buf) {
+			if (ulen > left) {
+				status = -ERANGE;
+				goto out;
+			}
+
+			memcpy(buf, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN);
+			memcpy(buf + XATTR_USER_PREFIX_LEN, p, len);
+
+			buf[ulen - 1] = 0;
+			buf += ulen;
+			left -= ulen;
+		}
+		copied += ulen;
+	}
+
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(!p))
+		return -EIO;
+
+	res->eof = be32_to_cpup(p);
+	res->copied = copied;
+
+out:
+	if (status == -ERANGE && res->xattr_len == XATTR_LIST_MAX)
+		status = -E2BIG;
+
+	return status;
+}
+
+/*
+ * Encode ALLOCATE request
+ */
+static void nfs4_xdr_enc_allocate(struct rpc_rqst *req,
+				  struct xdr_stream *xdr,
+				  const void *data)
+{
+	const struct nfs42_falloc_args *args = data;
+	struct compound_hdr hdr = {
+		.minorversion = nfs4_xdr_minorversion(&args->seq_args),
+	};
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_sequence(xdr, &args->seq_args, &hdr);
+	encode_putfh(xdr, args->falloc_fh, &hdr);
+	encode_allocate(xdr, args, &hdr);
+	encode_getfattr(xdr, args->falloc_bitmask, &hdr);
+	encode_nops(&hdr);
+}
+
+static void encode_copy_commit(struct xdr_stream *xdr,
+			  const struct nfs42_copy_args *args,
+			  struct compound_hdr *hdr)
+{
+	__be32 *p;
+
+	encode_op_hdr(xdr, OP_COMMIT, decode_commit_maxsz, hdr);
+	p = reserve_space(xdr, 12);
+	p = xdr_encode_hyper(p, args->dst_pos);
+	*p = cpu_to_be32(args->count);
+}
+
+/*
+ * Encode COPY request
+ */
+static void nfs4_xdr_enc_copy(struct rpc_rqst *req,
+			      struct xdr_stream *xdr,
+			      const void *data)
+{
+	const struct nfs42_copy_args *args = data;
+	struct compound_hdr hdr = {
+		.minorversion = nfs4_xdr_minorversion(&args->seq_args),
+	};
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_sequence(xdr, &args->seq_args, &hdr);
+	encode_putfh(xdr, args->src_fh, &hdr);
+	encode_savefh(xdr, &hdr);
+	encode_putfh(xdr, args->dst_fh, &hdr);
+	encode_copy(xdr, args, &hdr);
+	if (args->sync)
+		encode_copy_commit(xdr, args, &hdr);
+	encode_nops(&hdr);
+}
+
+/*
+ * Encode OFFLOAD_CANEL request
+ */
+static void nfs4_xdr_enc_offload_cancel(struct rpc_rqst *req,
+					struct xdr_stream *xdr,
+					const void *data)
+{
+	const struct nfs42_offload_status_args *args = data;
+	struct compound_hdr hdr = {
+		.minorversion = nfs4_xdr_minorversion(&args->osa_seq_args),
+	};
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_sequence(xdr, &args->osa_seq_args, &hdr);
+	encode_putfh(xdr, args->osa_src_fh, &hdr);
+	encode_offload_cancel(xdr, args, &hdr);
+	encode_nops(&hdr);
+}
+
+/*
+ * Encode COPY_NOTIFY request
+ */
+static void nfs4_xdr_enc_copy_notify(struct rpc_rqst *req,
+				     struct xdr_stream *xdr,
+				     const void *data)
+{
+	const struct nfs42_copy_notify_args *args = data;
+	struct compound_hdr hdr = {
+		.minorversion = nfs4_xdr_minorversion(&args->cna_seq_args),
+	};
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_sequence(xdr, &args->cna_seq_args, &hdr);
+	encode_putfh(xdr, args->cna_src_fh, &hdr);
+	encode_copy_notify(xdr, args, &hdr);
+	encode_nops(&hdr);
+}
+
+/*
+ * Encode DEALLOCATE request
+ */
+static void nfs4_xdr_enc_deallocate(struct rpc_rqst *req,
+				    struct xdr_stream *xdr,
+				    const void *data)
+{
+	const struct nfs42_falloc_args *args = data;
+	struct compound_hdr hdr = {
+		.minorversion = nfs4_xdr_minorversion(&args->seq_args),
+	};
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_sequence(xdr, &args->seq_args, &hdr);
+	encode_putfh(xdr, args->falloc_fh, &hdr);
+	encode_deallocate(xdr, args, &hdr);
+	encode_getfattr(xdr, args->falloc_bitmask, &hdr);
+	encode_nops(&hdr);
+}
+
+/*
+ * Encode READ_PLUS request
+ */
+static void nfs4_xdr_enc_read_plus(struct rpc_rqst *req,
+				   struct xdr_stream *xdr,
+				   const void *data)
+{
+	const struct nfs_pgio_args *args = data;
+	struct compound_hdr hdr = {
+		.minorversion = nfs4_xdr_minorversion(&args->seq_args),
+	};
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_sequence(xdr, &args->seq_args, &hdr);
+	encode_putfh(xdr, args->fh, &hdr);
+	encode_read_plus(xdr, args, &hdr);
+
+	rpc_prepare_reply_pages(req, args->pages, args->pgbase,
+				args->count, hdr.replen);
+	encode_nops(&hdr);
+}
+
+/*
+ * Encode SEEK request
+ */
+static void nfs4_xdr_enc_seek(struct rpc_rqst *req,
+			      struct xdr_stream *xdr,
+			      const void *data)
+{
+	const struct nfs42_seek_args *args = data;
+	struct compound_hdr hdr = {
+		.minorversion = nfs4_xdr_minorversion(&args->seq_args),
+	};
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_sequence(xdr, &args->seq_args, &hdr);
+	encode_putfh(xdr, args->sa_fh, &hdr);
+	encode_seek(xdr, args, &hdr);
+	encode_nops(&hdr);
+}
+
+/*
+ * Encode LAYOUTSTATS request
+ */
+static void nfs4_xdr_enc_layoutstats(struct rpc_rqst *req,
+				     struct xdr_stream *xdr,
+				     const void *data)
+{
+	const struct nfs42_layoutstat_args *args = data;
+	int i;
+
+	struct compound_hdr hdr = {
+		.minorversion = nfs4_xdr_minorversion(&args->seq_args),
+	};
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_sequence(xdr, &args->seq_args, &hdr);
+	encode_putfh(xdr, args->fh, &hdr);
+	WARN_ON(args->num_dev > PNFS_LAYOUTSTATS_MAXDEV);
+	for (i = 0; i < args->num_dev; i++)
+		encode_layoutstats(xdr, args, &args->devinfo[i], &hdr);
+	encode_nops(&hdr);
+}
+
+/*
+ * Encode CLONE request
+ */
+static void nfs4_xdr_enc_clone(struct rpc_rqst *req,
+			       struct xdr_stream *xdr,
+			       const void *data)
+{
+	const struct nfs42_clone_args *args = data;
+	struct compound_hdr hdr = {
+		.minorversion = nfs4_xdr_minorversion(&args->seq_args),
+	};
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_sequence(xdr, &args->seq_args, &hdr);
+	encode_putfh(xdr, args->src_fh, &hdr);
+	encode_savefh(xdr, &hdr);
+	encode_putfh(xdr, args->dst_fh, &hdr);
+	encode_clone(xdr, args, &hdr);
+	encode_getfattr(xdr, args->dst_bitmask, &hdr);
+	encode_nops(&hdr);
+}
+
+/*
+ * Encode LAYOUTERROR request
+ */
+static void nfs4_xdr_enc_layouterror(struct rpc_rqst *req,
+				     struct xdr_stream *xdr,
+				     const void *data)
+{
+	const struct nfs42_layouterror_args *args = data;
+	struct compound_hdr hdr = {
+		.minorversion = nfs4_xdr_minorversion(&args->seq_args),
+	};
+	int i;
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_sequence(xdr, &args->seq_args, &hdr);
+	encode_putfh(xdr, NFS_FH(args->inode), &hdr);
+	for (i = 0; i < args->num_errors; i++)
+		encode_layouterror(xdr, &args->errors[i], &hdr);
+	encode_nops(&hdr);
+}
+
+static int decode_allocate(struct xdr_stream *xdr, struct nfs42_falloc_res *res)
+{
+	return decode_op_hdr(xdr, OP_ALLOCATE);
+}
+
+static int decode_write_response(struct xdr_stream *xdr,
+				 struct nfs42_write_res *res)
+{
+	__be32 *p;
+	int status, count;
+
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(!p))
+		return -EIO;
+	count = be32_to_cpup(p);
+	if (count > 1)
+		return -EREMOTEIO;
+	else if (count == 1) {
+		status = decode_opaque_fixed(xdr, &res->stateid,
+				NFS4_STATEID_SIZE);
+		if (unlikely(status))
+			return -EIO;
+	}
+	p = xdr_inline_decode(xdr, 8 + 4);
+	if (unlikely(!p))
+		return -EIO;
+	p = xdr_decode_hyper(p, &res->count);
+	res->verifier.committed = be32_to_cpup(p);
+	return decode_verifier(xdr, &res->verifier.verifier);
+}
+
+static int decode_nl4_server(struct xdr_stream *xdr, struct nl4_server *ns)
+{
+	struct nfs42_netaddr *naddr;
+	uint32_t dummy;
+	char *dummy_str;
+	__be32 *p;
+	int status;
+
+	/* nl_type */
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(!p))
+		return -EIO;
+	ns->nl4_type = be32_to_cpup(p);
+	switch (ns->nl4_type) {
+	case NL4_NAME:
+	case NL4_URL:
+		status = decode_opaque_inline(xdr, &dummy, &dummy_str);
+		if (unlikely(status))
+			return status;
+		if (unlikely(dummy > NFS4_OPAQUE_LIMIT))
+			return -EIO;
+		memcpy(&ns->u.nl4_str, dummy_str, dummy);
+		ns->u.nl4_str_sz = dummy;
+		break;
+	case NL4_NETADDR:
+		naddr = &ns->u.nl4_addr;
+
+		/* netid string */
+		status = decode_opaque_inline(xdr, &dummy, &dummy_str);
+		if (unlikely(status))
+			return status;
+		if (unlikely(dummy > RPCBIND_MAXNETIDLEN))
+			return -EIO;
+		naddr->netid_len = dummy;
+		memcpy(naddr->netid, dummy_str, naddr->netid_len);
+
+		/* uaddr string */
+		status = decode_opaque_inline(xdr, &dummy, &dummy_str);
+		if (unlikely(status))
+			return status;
+		if (unlikely(dummy > RPCBIND_MAXUADDRLEN))
+			return -EIO;
+		naddr->addr_len = dummy;
+		memcpy(naddr->addr, dummy_str, naddr->addr_len);
+		break;
+	default:
+		WARN_ON_ONCE(1);
+		return -EIO;
+	}
+	return 0;
+}
+
+static int decode_copy_requirements(struct xdr_stream *xdr,
+				    struct nfs42_copy_res *res) {
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, 4 + 4);
+	if (unlikely(!p))
+		return -EIO;
+
+	res->consecutive = be32_to_cpup(p++);
+	res->synchronous = be32_to_cpup(p++);
+	return 0;
+}
+
+static int decode_copy(struct xdr_stream *xdr, struct nfs42_copy_res *res)
+{
+	int status;
+
+	status = decode_op_hdr(xdr, OP_COPY);
+	if (status == NFS4ERR_OFFLOAD_NO_REQS) {
+		status = decode_copy_requirements(xdr, res);
+		if (status)
+			return status;
+		return NFS4ERR_OFFLOAD_NO_REQS;
+	} else if (status)
+		return status;
+
+	status = decode_write_response(xdr, &res->write_res);
+	if (status)
+		return status;
+
+	return decode_copy_requirements(xdr, res);
+}
+
+static int decode_offload_cancel(struct xdr_stream *xdr,
+				 struct nfs42_offload_status_res *res)
+{
+	return decode_op_hdr(xdr, OP_OFFLOAD_CANCEL);
+}
+
+static int decode_copy_notify(struct xdr_stream *xdr,
+			      struct nfs42_copy_notify_res *res)
+{
+	__be32 *p;
+	int status, count;
+
+	status = decode_op_hdr(xdr, OP_COPY_NOTIFY);
+	if (status)
+		return status;
+	/* cnr_lease_time */
+	p = xdr_inline_decode(xdr, 12);
+	if (unlikely(!p))
+		return -EIO;
+	p = xdr_decode_hyper(p, &res->cnr_lease_time.seconds);
+	res->cnr_lease_time.nseconds = be32_to_cpup(p);
+
+	status = decode_opaque_fixed(xdr, &res->cnr_stateid, NFS4_STATEID_SIZE);
+	if (unlikely(status))
+		return -EIO;
+
+	/* number of source addresses */
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(!p))
+		return -EIO;
+
+	count = be32_to_cpup(p);
+	if (count > 1)
+		pr_warn("NFS: %s: nsvr %d > Supported. Use first servers\n",
+			 __func__, count);
+
+	status = decode_nl4_server(xdr, &res->cnr_src);
+	if (unlikely(status))
+		return -EIO;
+	return 0;
+}
+
+static int decode_deallocate(struct xdr_stream *xdr, struct nfs42_falloc_res *res)
+{
+	return decode_op_hdr(xdr, OP_DEALLOCATE);
+}
+
+static int decode_read_plus_data(struct xdr_stream *xdr,
+				 struct nfs_pgio_res *res)
+{
+	uint32_t count, recvd;
+	uint64_t offset;
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, 8 + 4);
+	if (!p)
+		return 1;
+
+	p = xdr_decode_hyper(p, &offset);
+	count = be32_to_cpup(p);
+	recvd = xdr_align_data(xdr, res->count, count);
+	res->count += recvd;
+
+	if (count > recvd)
+		return 1;
+	return 0;
+}
+
+static int decode_read_plus_hole(struct xdr_stream *xdr, struct nfs_pgio_res *res,
+				 uint32_t *eof)
+{
+	uint64_t offset, length, recvd;
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, 8 + 8);
+	if (!p)
+		return 1;
+
+	p = xdr_decode_hyper(p, &offset);
+	p = xdr_decode_hyper(p, &length);
+	recvd = xdr_expand_hole(xdr, res->count, length);
+	res->count += recvd;
+
+	if (recvd < length)
+		return 1;
+	return 0;
+}
+
+static int decode_read_plus(struct xdr_stream *xdr, struct nfs_pgio_res *res)
+{
+	uint32_t eof, segments, type;
+	int status, i;
+	__be32 *p;
+
+	status = decode_op_hdr(xdr, OP_READ_PLUS);
+	if (status)
+		return status;
+
+	p = xdr_inline_decode(xdr, 4 + 4);
+	if (unlikely(!p))
+		return -EIO;
+
+	eof = be32_to_cpup(p++);
+	segments = be32_to_cpup(p++);
+	if (segments == 0)
+		goto out;
+
+	for (i = 0; i < segments; i++) {
+		p = xdr_inline_decode(xdr, 4);
+		if (!p)
+			goto early_out;
+
+		type = be32_to_cpup(p++);
+		if (type == NFS4_CONTENT_DATA)
+			status = decode_read_plus_data(xdr, res);
+		else if (type == NFS4_CONTENT_HOLE)
+			status = decode_read_plus_hole(xdr, res, &eof);
+		else
+			return -EINVAL;
+
+		if (status < 0)
+			return status;
+		if (status > 0)
+			goto early_out;
+	}
+
+out:
+	res->eof = eof;
+	return 0;
+early_out:
+	if (unlikely(!i))
+		return -EIO;
+	res->eof = 0;
+	return 0;
+}
+
+static int decode_seek(struct xdr_stream *xdr, struct nfs42_seek_res *res)
+{
+	int status;
+	__be32 *p;
+
+	status = decode_op_hdr(xdr, OP_SEEK);
+	if (status)
+		return status;
+
+	p = xdr_inline_decode(xdr, 4 + 8);
+	if (unlikely(!p))
+		return -EIO;
+
+	res->sr_eof = be32_to_cpup(p++);
+	p = xdr_decode_hyper(p, &res->sr_offset);
+	return 0;
+}
+
+static int decode_layoutstats(struct xdr_stream *xdr)
+{
+	return decode_op_hdr(xdr, OP_LAYOUTSTATS);
+}
+
+static int decode_clone(struct xdr_stream *xdr)
+{
+	return decode_op_hdr(xdr, OP_CLONE);
+}
+
+static int decode_layouterror(struct xdr_stream *xdr)
+{
+	return decode_op_hdr(xdr, OP_LAYOUTERROR);
+}
+
+/*
+ * Decode ALLOCATE request
+ */
+static int nfs4_xdr_dec_allocate(struct rpc_rqst *rqstp,
+				 struct xdr_stream *xdr,
+				 void *data)
+{
+	struct nfs42_falloc_res *res = data;
+	struct compound_hdr hdr;
+	int status;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	if (status)
+		goto out;
+	status = decode_sequence(xdr, &res->seq_res, rqstp);
+	if (status)
+		goto out;
+	status = decode_putfh(xdr);
+	if (status)
+		goto out;
+	status = decode_allocate(xdr, res);
+	if (status)
+		goto out;
+	decode_getfattr(xdr, res->falloc_fattr, res->falloc_server);
+out:
+	return status;
+}
+
+/*
+ * Decode COPY response
+ */
+static int nfs4_xdr_dec_copy(struct rpc_rqst *rqstp,
+			     struct xdr_stream *xdr,
+			     void *data)
+{
+	struct nfs42_copy_res *res = data;
+	struct compound_hdr hdr;
+	int status;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	if (status)
+		goto out;
+	status = decode_sequence(xdr, &res->seq_res, rqstp);
+	if (status)
+		goto out;
+	status = decode_putfh(xdr);
+	if (status)
+		goto out;
+	status = decode_savefh(xdr);
+	if (status)
+		goto out;
+	status = decode_putfh(xdr);
+	if (status)
+		goto out;
+	status = decode_copy(xdr, res);
+	if (status)
+		goto out;
+	if (res->commit_res.verf)
+		status = decode_commit(xdr, &res->commit_res);
+out:
+	return status;
+}
+
+/*
+ * Decode OFFLOAD_CANCEL response
+ */
+static int nfs4_xdr_dec_offload_cancel(struct rpc_rqst *rqstp,
+				       struct xdr_stream *xdr,
+				       void *data)
+{
+	struct nfs42_offload_status_res *res = data;
+	struct compound_hdr hdr;
+	int status;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	if (status)
+		goto out;
+	status = decode_sequence(xdr, &res->osr_seq_res, rqstp);
+	if (status)
+		goto out;
+	status = decode_putfh(xdr);
+	if (status)
+		goto out;
+	status = decode_offload_cancel(xdr, res);
+
+out:
+	return status;
+}
+
+/*
+ * Decode COPY_NOTIFY response
+ */
+static int nfs4_xdr_dec_copy_notify(struct rpc_rqst *rqstp,
+				    struct xdr_stream *xdr,
+				    void *data)
+{
+	struct nfs42_copy_notify_res *res = data;
+	struct compound_hdr hdr;
+	int status;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	if (status)
+		goto out;
+	status = decode_sequence(xdr, &res->cnr_seq_res, rqstp);
+	if (status)
+		goto out;
+	status = decode_putfh(xdr);
+	if (status)
+		goto out;
+	status = decode_copy_notify(xdr, res);
+
+out:
+	return status;
+}
+
+/*
+ * Decode DEALLOCATE request
+ */
+static int nfs4_xdr_dec_deallocate(struct rpc_rqst *rqstp,
+				   struct xdr_stream *xdr,
+				   void *data)
+{
+	struct nfs42_falloc_res *res = data;
+	struct compound_hdr hdr;
+	int status;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	if (status)
+		goto out;
+	status = decode_sequence(xdr, &res->seq_res, rqstp);
+	if (status)
+		goto out;
+	status = decode_putfh(xdr);
+	if (status)
+		goto out;
+	status = decode_deallocate(xdr, res);
+	if (status)
+		goto out;
+	decode_getfattr(xdr, res->falloc_fattr, res->falloc_server);
+out:
+	return status;
+}
+
+/*
+ * Decode READ_PLUS request
+ */
+static int nfs4_xdr_dec_read_plus(struct rpc_rqst *rqstp,
+				  struct xdr_stream *xdr,
+				  void *data)
+{
+	struct nfs_pgio_res *res = data;
+	struct compound_hdr hdr;
+	int status;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	if (status)
+		goto out;
+	status = decode_sequence(xdr, &res->seq_res, rqstp);
+	if (status)
+		goto out;
+	status = decode_putfh(xdr);
+	if (status)
+		goto out;
+	status = decode_read_plus(xdr, res);
+	if (!status)
+		status = res->count;
+out:
+	return status;
+}
+
+/*
+ * Decode SEEK request
+ */
+static int nfs4_xdr_dec_seek(struct rpc_rqst *rqstp,
+			     struct xdr_stream *xdr,
+			     void *data)
+{
+	struct nfs42_seek_res *res = data;
+	struct compound_hdr hdr;
+	int status;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	if (status)
+		goto out;
+	status = decode_sequence(xdr, &res->seq_res, rqstp);
+	if (status)
+		goto out;
+	status = decode_putfh(xdr);
+	if (status)
+		goto out;
+	status = decode_seek(xdr, res);
+out:
+	return status;
+}
+
+/*
+ * Decode LAYOUTSTATS request
+ */
+static int nfs4_xdr_dec_layoutstats(struct rpc_rqst *rqstp,
+				    struct xdr_stream *xdr,
+				    void *data)
+{
+	struct nfs42_layoutstat_res *res = data;
+	struct compound_hdr hdr;
+	int status, i;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	if (status)
+		goto out;
+	status = decode_sequence(xdr, &res->seq_res, rqstp);
+	if (status)
+		goto out;
+	status = decode_putfh(xdr);
+	if (status)
+		goto out;
+	WARN_ON(res->num_dev > PNFS_LAYOUTSTATS_MAXDEV);
+	for (i = 0; i < res->num_dev; i++) {
+		status = decode_layoutstats(xdr);
+		if (status)
+			goto out;
+	}
+out:
+	res->rpc_status = status;
+	return status;
+}
+
+/*
+ * Decode CLONE request
+ */
+static int nfs4_xdr_dec_clone(struct rpc_rqst *rqstp,
+			      struct xdr_stream *xdr,
+			      void *data)
+{
+	struct nfs42_clone_res *res = data;
+	struct compound_hdr hdr;
+	int status;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	if (status)
+		goto out;
+	status = decode_sequence(xdr, &res->seq_res, rqstp);
+	if (status)
+		goto out;
+	status = decode_putfh(xdr);
+	if (status)
+		goto out;
+	status = decode_savefh(xdr);
+	if (status)
+		goto out;
+	status = decode_putfh(xdr);
+	if (status)
+		goto out;
+	status = decode_clone(xdr);
+	if (status)
+		goto out;
+	decode_getfattr(xdr, res->dst_fattr, res->server);
+out:
+	res->rpc_status = status;
+	return status;
+}
+
+/*
+ * Decode LAYOUTERROR request
+ */
+static int nfs4_xdr_dec_layouterror(struct rpc_rqst *rqstp,
+				    struct xdr_stream *xdr,
+				    void *data)
+{
+	struct nfs42_layouterror_res *res = data;
+	struct compound_hdr hdr;
+	int status, i;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	if (status)
+		goto out;
+	status = decode_sequence(xdr, &res->seq_res, rqstp);
+	if (status)
+		goto out;
+	status = decode_putfh(xdr);
+
+	for (i = 0; i < res->num_errors && status == 0; i++)
+		status = decode_layouterror(xdr);
+out:
+	res->rpc_status = status;
+	return status;
+}
+
+#ifdef CONFIG_NFS_V4_2
+static void nfs4_xdr_enc_setxattr(struct rpc_rqst *req, struct xdr_stream *xdr,
+				  const void *data)
+{
+	const struct nfs42_setxattrargs *args = data;
+	struct compound_hdr hdr = {
+		.minorversion = nfs4_xdr_minorversion(&args->seq_args),
+	};
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_sequence(xdr, &args->seq_args, &hdr);
+	encode_putfh(xdr, args->fh, &hdr);
+	encode_setxattr(xdr, args, &hdr);
+	encode_nops(&hdr);
+}
+
+static int nfs4_xdr_dec_setxattr(struct rpc_rqst *req, struct xdr_stream *xdr,
+				 void *data)
+{
+	struct nfs42_setxattrres *res = data;
+	struct compound_hdr hdr;
+	int status;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	if (status)
+		goto out;
+	status = decode_sequence(xdr, &res->seq_res, req);
+	if (status)
+		goto out;
+	status = decode_putfh(xdr);
+	if (status)
+		goto out;
+
+	status = decode_setxattr(xdr, &res->cinfo);
+out:
+	return status;
+}
+
+static void nfs4_xdr_enc_getxattr(struct rpc_rqst *req, struct xdr_stream *xdr,
+				  const void *data)
+{
+	const struct nfs42_getxattrargs *args = data;
+	struct compound_hdr hdr = {
+		.minorversion = nfs4_xdr_minorversion(&args->seq_args),
+	};
+	size_t plen;
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_sequence(xdr, &args->seq_args, &hdr);
+	encode_putfh(xdr, args->fh, &hdr);
+	encode_getxattr(xdr, args->xattr_name, &hdr);
+
+	plen = args->xattr_len ? args->xattr_len : XATTR_SIZE_MAX;
+
+	rpc_prepare_reply_pages(req, args->xattr_pages, 0, plen,
+	    hdr.replen);
+	req->rq_rcv_buf.flags |= XDRBUF_SPARSE_PAGES;
+
+	encode_nops(&hdr);
+}
+
+static int nfs4_xdr_dec_getxattr(struct rpc_rqst *rqstp,
+				 struct xdr_stream *xdr, void *data)
+{
+	struct nfs42_getxattrres *res = data;
+	struct compound_hdr hdr;
+	int status;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	if (status)
+		goto out;
+	status = decode_sequence(xdr, &res->seq_res, rqstp);
+	if (status)
+		goto out;
+	status = decode_putfh(xdr);
+	if (status)
+		goto out;
+	status = decode_getxattr(xdr, res, rqstp);
+out:
+	return status;
+}
+
+static void nfs4_xdr_enc_listxattrs(struct rpc_rqst *req,
+				    struct xdr_stream *xdr, const void *data)
+{
+	const struct nfs42_listxattrsargs *args = data;
+	struct compound_hdr hdr = {
+		.minorversion = nfs4_xdr_minorversion(&args->seq_args),
+	};
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_sequence(xdr, &args->seq_args, &hdr);
+	encode_putfh(xdr, args->fh, &hdr);
+	encode_listxattrs(xdr, args, &hdr);
+
+	rpc_prepare_reply_pages(req, args->xattr_pages, 0, args->count,
+	    hdr.replen);
+
+	encode_nops(&hdr);
+}
+
+static int nfs4_xdr_dec_listxattrs(struct rpc_rqst *rqstp,
+				   struct xdr_stream *xdr, void *data)
+{
+	struct nfs42_listxattrsres *res = data;
+	struct compound_hdr hdr;
+	int status;
+
+	xdr_set_scratch_buffer(xdr, page_address(res->scratch), PAGE_SIZE);
+
+	status = decode_compound_hdr(xdr, &hdr);
+	if (status)
+		goto out;
+	status = decode_sequence(xdr, &res->seq_res, rqstp);
+	if (status)
+		goto out;
+	status = decode_putfh(xdr);
+	if (status)
+		goto out;
+	status = decode_listxattrs(xdr, res);
+out:
+	return status;
+}
+
+static void nfs4_xdr_enc_removexattr(struct rpc_rqst *req,
+				     struct xdr_stream *xdr, const void *data)
+{
+	const struct nfs42_removexattrargs *args = data;
+	struct compound_hdr hdr = {
+		.minorversion = nfs4_xdr_minorversion(&args->seq_args),
+	};
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_sequence(xdr, &args->seq_args, &hdr);
+	encode_putfh(xdr, args->fh, &hdr);
+	encode_removexattr(xdr, args->xattr_name, &hdr);
+	encode_nops(&hdr);
+}
+
+static int nfs4_xdr_dec_removexattr(struct rpc_rqst *req,
+				    struct xdr_stream *xdr, void *data)
+{
+	struct nfs42_removexattrres *res = data;
+	struct compound_hdr hdr;
+	int status;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	if (status)
+		goto out;
+	status = decode_sequence(xdr, &res->seq_res, req);
+	if (status)
+		goto out;
+	status = decode_putfh(xdr);
+	if (status)
+		goto out;
+
+	status = decode_removexattr(xdr, &res->cinfo);
+out:
+	return status;
+}
+#endif
+#endif /* __LINUX_FS_NFS_NFS4_2XDR_H */
diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h
new file mode 100644
index 000000000..8b41c0b86
--- /dev/null
+++ b/fs/nfs/nfs4_fs.h
@@ -0,0 +1,671 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * linux/fs/nfs/nfs4_fs.h
+ *
+ * Copyright (C) 2005 Trond Myklebust
+ *
+ * NFSv4-specific filesystem definitions and declarations
+ */
+
+#ifndef __LINUX_FS_NFS_NFS4_FS_H
+#define __LINUX_FS_NFS_NFS4_FS_H
+
+#if defined(CONFIG_NFS_V4_2)
+#define NFS4_MAX_MINOR_VERSION 2
+#elif defined(CONFIG_NFS_V4_1)
+#define NFS4_MAX_MINOR_VERSION 1
+#else
+#define NFS4_MAX_MINOR_VERSION 0
+#endif
+
+#if IS_ENABLED(CONFIG_NFS_V4)
+
+#define NFS4_MAX_LOOP_ON_RECOVER (10)
+
+#include <linux/seqlock.h>
+
+struct idmap;
+
+enum nfs4_client_state {
+	NFS4CLNT_MANAGER_RUNNING  = 0,
+	NFS4CLNT_CHECK_LEASE,
+	NFS4CLNT_LEASE_EXPIRED,
+	NFS4CLNT_RECLAIM_REBOOT,
+	NFS4CLNT_RECLAIM_NOGRACE,
+	NFS4CLNT_DELEGRETURN,
+	NFS4CLNT_SESSION_RESET,
+	NFS4CLNT_LEASE_CONFIRM,
+	NFS4CLNT_SERVER_SCOPE_MISMATCH,
+	NFS4CLNT_PURGE_STATE,
+	NFS4CLNT_BIND_CONN_TO_SESSION,
+	NFS4CLNT_MOVED,
+	NFS4CLNT_LEASE_MOVED,
+	NFS4CLNT_DELEGATION_EXPIRED,
+	NFS4CLNT_RUN_MANAGER,
+	NFS4CLNT_MANAGER_AVAILABLE,
+	NFS4CLNT_RECALL_RUNNING,
+	NFS4CLNT_RECALL_ANY_LAYOUT_READ,
+	NFS4CLNT_RECALL_ANY_LAYOUT_RW,
+	NFS4CLNT_DELEGRETURN_DELAYED,
+};
+
+#define NFS4_RENEW_TIMEOUT		0x01
+#define NFS4_RENEW_DELEGATION_CB	0x02
+
+struct nfs_seqid_counter;
+struct nfs4_minor_version_ops {
+	u32	minor_version;
+	unsigned init_caps;
+
+	int	(*init_client)(struct nfs_client *);
+	void	(*shutdown_client)(struct nfs_client *);
+	bool	(*match_stateid)(const nfs4_stateid *,
+			const nfs4_stateid *);
+	int	(*find_root_sec)(struct nfs_server *, struct nfs_fh *,
+			struct nfs_fsinfo *);
+	void	(*free_lock_state)(struct nfs_server *,
+			struct nfs4_lock_state *);
+	int	(*test_and_free_expired)(struct nfs_server *,
+			nfs4_stateid *, const struct cred *);
+	struct nfs_seqid *
+		(*alloc_seqid)(struct nfs_seqid_counter *, gfp_t);
+	void	(*session_trunk)(struct rpc_clnt *clnt,
+			struct rpc_xprt *xprt, void *data);
+	const struct rpc_call_ops *call_sync_ops;
+	const struct nfs4_state_recovery_ops *reboot_recovery_ops;
+	const struct nfs4_state_recovery_ops *nograce_recovery_ops;
+	const struct nfs4_state_maintenance_ops *state_renewal_ops;
+	const struct nfs4_mig_recovery_ops *mig_recovery_ops;
+};
+
+#define NFS_SEQID_CONFIRMED 1
+struct nfs_seqid_counter {
+	ktime_t create_time;
+	int owner_id;
+	int flags;
+	u32 counter;
+	spinlock_t lock;		/* Protects the list */
+	struct list_head list;		/* Defines sequence of RPC calls */
+	struct rpc_wait_queue	wait;	/* RPC call delay queue */
+};
+
+struct nfs_seqid {
+	struct nfs_seqid_counter *sequence;
+	struct list_head list;
+	struct rpc_task *task;
+};
+
+static inline void nfs_confirm_seqid(struct nfs_seqid_counter *seqid, int status)
+{
+	if (seqid_mutating_err(-status))
+		seqid->flags |= NFS_SEQID_CONFIRMED;
+}
+
+/*
+ * NFS4 state_owners and lock_owners are simply labels for ordered
+ * sequences of RPC calls. Their sole purpose is to provide once-only
+ * semantics by allowing the server to identify replayed requests.
+ */
+struct nfs4_state_owner {
+	struct nfs_server    *so_server;
+	struct list_head     so_lru;
+	unsigned long        so_expires;
+	struct rb_node	     so_server_node;
+
+	const struct cred    *so_cred;	 /* Associated cred */
+
+	spinlock_t	     so_lock;
+	atomic_t	     so_count;
+	unsigned long	     so_flags;
+	struct list_head     so_states;
+	struct nfs_seqid_counter so_seqid;
+	seqcount_spinlock_t  so_reclaim_seqcount;
+	struct mutex	     so_delegreturn_mutex;
+};
+
+enum {
+	NFS_OWNER_RECLAIM_REBOOT,
+	NFS_OWNER_RECLAIM_NOGRACE
+};
+
+#define NFS_LOCK_NEW		0
+#define NFS_LOCK_RECLAIM	1
+#define NFS_LOCK_EXPIRED	2
+
+/*
+ * struct nfs4_state maintains the client-side state for a given
+ * (state_owner,inode) tuple (OPEN) or state_owner (LOCK).
+ *
+ * OPEN:
+ * In order to know when to OPEN_DOWNGRADE or CLOSE the state on the server,
+ * we need to know how many files are open for reading or writing on a
+ * given inode. This information too is stored here.
+ *
+ * LOCK: one nfs4_state (LOCK) to hold the lock stateid nfs4_state(OPEN)
+ */
+
+struct nfs4_lock_state {
+	struct list_head	ls_locks;	/* Other lock stateids */
+	struct nfs4_state *	ls_state;	/* Pointer to open state */
+#define NFS_LOCK_INITIALIZED 0
+#define NFS_LOCK_LOST        1
+	unsigned long		ls_flags;
+	struct nfs_seqid_counter	ls_seqid;
+	nfs4_stateid		ls_stateid;
+	refcount_t		ls_count;
+	fl_owner_t		ls_owner;
+};
+
+/* bits for nfs4_state->flags */
+enum {
+	LK_STATE_IN_USE,
+	NFS_DELEGATED_STATE,		/* Current stateid is delegation */
+	NFS_OPEN_STATE,			/* OPEN stateid is set */
+	NFS_O_RDONLY_STATE,		/* OPEN stateid has read-only state */
+	NFS_O_WRONLY_STATE,		/* OPEN stateid has write-only state */
+	NFS_O_RDWR_STATE,		/* OPEN stateid has read/write state */
+	NFS_STATE_RECLAIM_REBOOT,	/* OPEN stateid server rebooted */
+	NFS_STATE_RECLAIM_NOGRACE,	/* OPEN stateid needs to recover state */
+	NFS_STATE_POSIX_LOCKS,		/* Posix locks are supported */
+	NFS_STATE_RECOVERY_FAILED,	/* OPEN stateid state recovery failed */
+	NFS_STATE_MAY_NOTIFY_LOCK,	/* server may CB_NOTIFY_LOCK */
+	NFS_STATE_CHANGE_WAIT,		/* A state changing operation is outstanding */
+	NFS_CLNT_DST_SSC_COPY_STATE,    /* dst server open state on client*/
+	NFS_CLNT_SRC_SSC_COPY_STATE,    /* src server open state on client*/
+	NFS_SRV_SSC_COPY_STATE,		/* ssc state on the dst server */
+};
+
+struct nfs4_state {
+	struct list_head open_states;	/* List of states for the same state_owner */
+	struct list_head inode_states;	/* List of states for the same inode */
+	struct list_head lock_states;	/* List of subservient lock stateids */
+
+	struct nfs4_state_owner *owner;	/* Pointer to the open owner */
+	struct inode *inode;		/* Pointer to the inode */
+
+	unsigned long flags;		/* Do we hold any locks? */
+	spinlock_t state_lock;		/* Protects the lock_states list */
+
+	seqlock_t seqlock;		/* Protects the stateid/open_stateid */
+	nfs4_stateid stateid;		/* Current stateid: may be delegation */
+	nfs4_stateid open_stateid;	/* OPEN stateid */
+
+	/* The following 3 fields are protected by owner->so_lock */
+	unsigned int n_rdonly;		/* Number of read-only references */
+	unsigned int n_wronly;		/* Number of write-only references */
+	unsigned int n_rdwr;		/* Number of read/write references */
+	fmode_t state;			/* State on the server (R,W, or RW) */
+	refcount_t count;
+
+	wait_queue_head_t waitq;
+	struct rcu_head rcu_head;
+};
+
+
+struct nfs4_exception {
+	struct nfs4_state *state;
+	struct inode *inode;
+	nfs4_stateid *stateid;
+	long timeout;
+	unsigned char task_is_privileged : 1;
+	unsigned char delay : 1,
+		      recovering : 1,
+		      retry : 1;
+	bool interruptible;
+};
+
+struct nfs4_state_recovery_ops {
+	int owner_flag_bit;
+	int state_flag_bit;
+	int (*recover_open)(struct nfs4_state_owner *, struct nfs4_state *);
+	int (*recover_lock)(struct nfs4_state *, struct file_lock *);
+	int (*establish_clid)(struct nfs_client *, const struct cred *);
+	int (*reclaim_complete)(struct nfs_client *, const struct cred *);
+	int (*detect_trunking)(struct nfs_client *, struct nfs_client **,
+		const struct cred *);
+};
+
+struct nfs4_opendata {
+	struct kref kref;
+	struct nfs_openargs o_arg;
+	struct nfs_openres o_res;
+	struct nfs_open_confirmargs c_arg;
+	struct nfs_open_confirmres c_res;
+	struct nfs4_string owner_name;
+	struct nfs4_string group_name;
+	struct nfs4_label *a_label;
+	struct nfs_fattr f_attr;
+	struct nfs4_label *f_label;
+	struct dentry *dir;
+	struct dentry *dentry;
+	struct nfs4_state_owner *owner;
+	struct nfs4_state *state;
+	struct iattr attrs;
+	struct nfs4_layoutget *lgp;
+	unsigned long timestamp;
+	bool rpc_done;
+	bool file_created;
+	bool is_recover;
+	bool cancelled;
+	int rpc_status;
+};
+
+struct nfs4_add_xprt_data {
+	struct nfs_client	*clp;
+	const struct cred	*cred;
+};
+
+struct nfs4_state_maintenance_ops {
+	int (*sched_state_renewal)(struct nfs_client *, const struct cred *, unsigned);
+	const struct cred * (*get_state_renewal_cred)(struct nfs_client *);
+	int (*renew_lease)(struct nfs_client *, const struct cred *);
+};
+
+struct nfs4_mig_recovery_ops {
+	int (*get_locations)(struct inode *, struct nfs4_fs_locations *,
+		struct page *, const struct cred *);
+	int (*fsid_present)(struct inode *, const struct cred *);
+};
+
+extern const struct dentry_operations nfs4_dentry_operations;
+
+/* dir.c */
+int nfs_atomic_open(struct inode *, struct dentry *, struct file *,
+		    unsigned, umode_t);
+
+/* fs_context.c */
+extern struct file_system_type nfs4_fs_type;
+
+/* nfs4namespace.c */
+struct rpc_clnt *nfs4_negotiate_security(struct rpc_clnt *, struct inode *,
+					 const struct qstr *);
+int nfs4_submount(struct fs_context *, struct nfs_server *);
+int nfs4_replace_transport(struct nfs_server *server,
+				const struct nfs4_fs_locations *locations);
+size_t nfs_parse_server_name(char *string, size_t len, struct sockaddr *sa,
+			     size_t salen, struct net *net, int port);
+/* nfs4proc.c */
+extern int nfs4_handle_exception(struct nfs_server *, int, struct nfs4_exception *);
+extern int nfs4_async_handle_error(struct rpc_task *task,
+				   struct nfs_server *server,
+				   struct nfs4_state *state, long *timeout);
+extern int nfs4_call_sync(struct rpc_clnt *, struct nfs_server *,
+			  struct rpc_message *, struct nfs4_sequence_args *,
+			  struct nfs4_sequence_res *, int);
+extern void nfs4_init_sequence(struct nfs4_sequence_args *, struct nfs4_sequence_res *, int, int);
+extern int nfs4_proc_setclientid(struct nfs_client *, u32, unsigned short, const struct cred *, struct nfs4_setclientid_res *);
+extern int nfs4_proc_setclientid_confirm(struct nfs_client *, struct nfs4_setclientid_res *arg, const struct cred *);
+extern int nfs4_proc_get_rootfh(struct nfs_server *, struct nfs_fh *, struct nfs_fsinfo *, bool);
+extern int nfs4_proc_bind_conn_to_session(struct nfs_client *, const struct cred *cred);
+extern int nfs4_proc_exchange_id(struct nfs_client *clp, const struct cred *cred);
+extern int nfs4_destroy_clientid(struct nfs_client *clp);
+extern int nfs4_init_clientid(struct nfs_client *, const struct cred *);
+extern int nfs41_init_clientid(struct nfs_client *, const struct cred *);
+extern int nfs4_do_close(struct nfs4_state *state, gfp_t gfp_mask, int wait);
+extern int nfs4_server_capabilities(struct nfs_server *server, struct nfs_fh *fhandle);
+extern int nfs4_proc_fs_locations(struct rpc_clnt *, struct inode *, const struct qstr *,
+				  struct nfs4_fs_locations *, struct page *);
+extern int nfs4_proc_get_locations(struct inode *, struct nfs4_fs_locations *,
+		struct page *page, const struct cred *);
+extern int nfs4_proc_fsid_present(struct inode *, const struct cred *);
+extern struct rpc_clnt *nfs4_proc_lookup_mountpoint(struct inode *,
+						    struct dentry *,
+						    struct nfs_fh *,
+						    struct nfs_fattr *);
+extern int nfs4_proc_secinfo(struct inode *, const struct qstr *, struct nfs4_secinfo_flavors *);
+extern const struct xattr_handler *nfs4_xattr_handlers[];
+extern int nfs4_set_rw_stateid(nfs4_stateid *stateid,
+		const struct nfs_open_context *ctx,
+		const struct nfs_lock_context *l_ctx,
+		fmode_t fmode);
+extern int nfs4_proc_getattr(struct nfs_server *server, struct nfs_fh *fhandle,
+			     struct nfs_fattr *fattr, struct nfs4_label *label,
+			     struct inode *inode);
+extern int update_open_stateid(struct nfs4_state *state,
+				const nfs4_stateid *open_stateid,
+				const nfs4_stateid *deleg_stateid,
+				fmode_t fmode);
+
+extern int nfs4_proc_get_lease_time(struct nfs_client *clp,
+		struct nfs_fsinfo *fsinfo);
+extern void nfs4_update_changeattr(struct inode *dir,
+				   struct nfs4_change_info *cinfo,
+				   unsigned long timestamp,
+				   unsigned long cache_validity);
+extern int nfs4_buf_to_pages_noslab(const void *buf, size_t buflen,
+				    struct page **pages);
+
+#if defined(CONFIG_NFS_V4_1)
+extern int nfs41_sequence_done(struct rpc_task *, struct nfs4_sequence_res *);
+extern int nfs4_proc_create_session(struct nfs_client *, const struct cred *);
+extern int nfs4_proc_destroy_session(struct nfs4_session *, const struct cred *);
+extern int nfs4_proc_layoutcommit(struct nfs4_layoutcommit_data *data,
+				  bool sync);
+extern int nfs4_detect_session_trunking(struct nfs_client *clp,
+		struct nfs41_exchange_id_res *res, struct rpc_xprt *xprt);
+
+static inline bool
+is_ds_only_client(struct nfs_client *clp)
+{
+	return (clp->cl_exchange_flags & EXCHGID4_FLAG_MASK_PNFS) ==
+		EXCHGID4_FLAG_USE_PNFS_DS;
+}
+
+static inline bool
+is_ds_client(struct nfs_client *clp)
+{
+	return clp->cl_exchange_flags & EXCHGID4_FLAG_USE_PNFS_DS;
+}
+
+static inline bool
+_nfs4_state_protect(struct nfs_client *clp, unsigned long sp4_mode,
+		    struct rpc_clnt **clntp, struct rpc_message *msg)
+{
+	rpc_authflavor_t flavor;
+
+	if (sp4_mode == NFS_SP4_MACH_CRED_CLEANUP ||
+	    sp4_mode == NFS_SP4_MACH_CRED_PNFS_CLEANUP) {
+		/* Using machine creds for cleanup operations
+		 * is only relevent if the client credentials
+		 * might expire. So don't bother for
+		 * RPC_AUTH_UNIX.  If file was only exported to
+		 * sec=sys, the PUTFH would fail anyway.
+		 */
+		if ((*clntp)->cl_auth->au_flavor == RPC_AUTH_UNIX)
+			return false;
+	}
+	if (test_bit(sp4_mode, &clp->cl_sp4_flags)) {
+		msg->rpc_cred = rpc_machine_cred();
+
+		flavor = clp->cl_rpcclient->cl_auth->au_flavor;
+		WARN_ON_ONCE(flavor != RPC_AUTH_GSS_KRB5I &&
+			     flavor != RPC_AUTH_GSS_KRB5P);
+		*clntp = clp->cl_rpcclient;
+
+		return true;
+	}
+	return false;
+}
+
+/*
+ * Function responsible for determining if an rpc_message should use the
+ * machine cred under SP4_MACH_CRED and if so switching the credential and
+ * authflavor (using the nfs_client's rpc_clnt which will be krb5i/p).
+ * Should be called before rpc_call_sync/rpc_call_async.
+ */
+static inline void
+nfs4_state_protect(struct nfs_client *clp, unsigned long sp4_mode,
+		   struct rpc_clnt **clntp, struct rpc_message *msg)
+{
+	_nfs4_state_protect(clp, sp4_mode, clntp, msg);
+}
+
+/*
+ * Special wrapper to nfs4_state_protect for write.
+ * If WRITE can use machine cred but COMMIT cannot, make sure all writes
+ * that use machine cred use NFS_FILE_SYNC.
+ */
+static inline void
+nfs4_state_protect_write(struct nfs_client *clp, struct rpc_clnt **clntp,
+			 struct rpc_message *msg, struct nfs_pgio_header *hdr)
+{
+	if (_nfs4_state_protect(clp, NFS_SP4_MACH_CRED_WRITE, clntp, msg) &&
+	    !test_bit(NFS_SP4_MACH_CRED_COMMIT, &clp->cl_sp4_flags))
+		hdr->args.stable = NFS_FILE_SYNC;
+}
+#else /* CONFIG_NFS_v4_1 */
+static inline bool
+is_ds_only_client(struct nfs_client *clp)
+{
+	return false;
+}
+
+static inline bool
+is_ds_client(struct nfs_client *clp)
+{
+	return false;
+}
+
+static inline void
+nfs4_state_protect(struct nfs_client *clp, unsigned long sp4_flags,
+		   struct rpc_clnt **clntp, struct rpc_message *msg)
+{
+}
+
+static inline void
+nfs4_state_protect_write(struct nfs_client *clp, struct rpc_clnt **clntp,
+			 struct rpc_message *msg, struct nfs_pgio_header *hdr)
+{
+}
+#endif /* CONFIG_NFS_V4_1 */
+
+extern const struct nfs4_minor_version_ops *nfs_v4_minor_ops[];
+
+extern const u32 nfs4_fattr_bitmap[3];
+extern const u32 nfs4_statfs_bitmap[3];
+extern const u32 nfs4_pathconf_bitmap[3];
+extern const u32 nfs4_fsinfo_bitmap[3];
+extern const u32 nfs4_fs_locations_bitmap[3];
+
+void nfs40_shutdown_client(struct nfs_client *);
+void nfs41_shutdown_client(struct nfs_client *);
+int nfs40_init_client(struct nfs_client *);
+int nfs41_init_client(struct nfs_client *);
+void nfs4_free_client(struct nfs_client *);
+
+struct nfs_client *nfs4_alloc_client(const struct nfs_client_initdata *);
+
+/* nfs4renewd.c */
+extern void nfs4_schedule_state_renewal(struct nfs_client *);
+extern void nfs4_renewd_prepare_shutdown(struct nfs_server *);
+extern void nfs4_kill_renewd(struct nfs_client *);
+extern void nfs4_renew_state(struct work_struct *);
+extern void nfs4_set_lease_period(struct nfs_client *clp, unsigned long lease);
+
+
+/* nfs4state.c */
+extern const nfs4_stateid current_stateid;
+
+const struct cred *nfs4_get_clid_cred(struct nfs_client *clp);
+const struct cred *nfs4_get_machine_cred(struct nfs_client *clp);
+const struct cred *nfs4_get_renew_cred(struct nfs_client *clp);
+int nfs4_discover_server_trunking(struct nfs_client *clp,
+			struct nfs_client **);
+int nfs40_discover_server_trunking(struct nfs_client *clp,
+			struct nfs_client **, const struct cred *);
+#if defined(CONFIG_NFS_V4_1)
+int nfs41_discover_server_trunking(struct nfs_client *clp,
+			struct nfs_client **, const struct cred *);
+extern void nfs4_schedule_session_recovery(struct nfs4_session *, int);
+extern void nfs41_notify_server(struct nfs_client *);
+bool nfs4_check_serverowner_major_id(struct nfs41_server_owner *o1,
+			struct nfs41_server_owner *o2);
+#else
+static inline void nfs4_schedule_session_recovery(struct nfs4_session *session, int err)
+{
+}
+#endif /* CONFIG_NFS_V4_1 */
+
+extern struct nfs4_state_owner *nfs4_get_state_owner(struct nfs_server *, const struct cred *, gfp_t);
+extern void nfs4_put_state_owner(struct nfs4_state_owner *);
+extern void nfs4_purge_state_owners(struct nfs_server *, struct list_head *);
+extern void nfs4_free_state_owners(struct list_head *head);
+extern struct nfs4_state * nfs4_get_open_state(struct inode *, struct nfs4_state_owner *);
+extern void nfs4_put_open_state(struct nfs4_state *);
+extern void nfs4_close_state(struct nfs4_state *, fmode_t);
+extern void nfs4_close_sync(struct nfs4_state *, fmode_t);
+extern void nfs4_state_set_mode_locked(struct nfs4_state *, fmode_t);
+extern void nfs_inode_find_state_and_recover(struct inode *inode,
+		const nfs4_stateid *stateid);
+extern int nfs4_state_mark_reclaim_nograce(struct nfs_client *, struct nfs4_state *);
+extern void nfs4_schedule_lease_recovery(struct nfs_client *);
+extern int nfs4_wait_clnt_recover(struct nfs_client *clp);
+extern int nfs4_client_recover_expired_lease(struct nfs_client *clp);
+extern void nfs4_schedule_state_manager(struct nfs_client *);
+extern void nfs4_schedule_path_down_recovery(struct nfs_client *clp);
+extern int nfs4_schedule_stateid_recovery(const struct nfs_server *, struct nfs4_state *);
+extern int nfs4_schedule_migration_recovery(const struct nfs_server *);
+extern void nfs4_schedule_lease_moved_recovery(struct nfs_client *);
+extern void nfs41_handle_sequence_flag_errors(struct nfs_client *clp, u32 flags, bool);
+extern void nfs41_handle_server_scope(struct nfs_client *,
+				      struct nfs41_server_scope **);
+extern void nfs4_put_lock_state(struct nfs4_lock_state *lsp);
+extern int nfs4_set_lock_state(struct nfs4_state *state, struct file_lock *fl);
+extern int nfs4_select_rw_stateid(struct nfs4_state *, fmode_t,
+		const struct nfs_lock_context *, nfs4_stateid *,
+		const struct cred **);
+extern bool nfs4_copy_open_stateid(nfs4_stateid *dst,
+		struct nfs4_state *state);
+
+extern struct nfs_seqid *nfs_alloc_seqid(struct nfs_seqid_counter *counter, gfp_t gfp_mask);
+extern int nfs_wait_on_sequence(struct nfs_seqid *seqid, struct rpc_task *task);
+extern void nfs_increment_open_seqid(int status, struct nfs_seqid *seqid);
+extern void nfs_increment_lock_seqid(int status, struct nfs_seqid *seqid);
+extern void nfs_release_seqid(struct nfs_seqid *seqid);
+extern void nfs_free_seqid(struct nfs_seqid *seqid);
+extern int nfs4_setup_sequence(struct nfs_client *client,
+				struct nfs4_sequence_args *args,
+				struct nfs4_sequence_res *res,
+				struct rpc_task *task);
+extern int nfs4_sequence_done(struct rpc_task *task,
+			      struct nfs4_sequence_res *res);
+
+extern void nfs4_free_lock_state(struct nfs_server *server, struct nfs4_lock_state *lsp);
+extern int nfs4_proc_commit(struct file *dst, __u64 offset, __u32 count, struct nfs_commitres *res);
+extern const nfs4_stateid zero_stateid;
+extern const nfs4_stateid invalid_stateid;
+
+/* nfs4super.c */
+struct nfs_mount_info;
+extern struct nfs_subversion nfs_v4;
+extern bool nfs4_disable_idmapping;
+extern unsigned short max_session_slots;
+extern unsigned short max_session_cb_slots;
+extern unsigned short send_implementation_id;
+extern bool recover_lost_locks;
+
+#define NFS4_CLIENT_ID_UNIQ_LEN		(64)
+extern char nfs4_client_id_uniquifier[NFS4_CLIENT_ID_UNIQ_LEN];
+
+extern int nfs4_try_get_tree(struct fs_context *);
+extern int nfs4_get_referral_tree(struct fs_context *);
+
+/* nfs4sysctl.c */
+#ifdef CONFIG_SYSCTL
+int nfs4_register_sysctl(void);
+void nfs4_unregister_sysctl(void);
+#else
+static inline int nfs4_register_sysctl(void)
+{
+	return 0;
+}
+
+static inline void nfs4_unregister_sysctl(void)
+{
+}
+#endif
+
+/* nfs4xdr.c */
+extern const struct rpc_procinfo nfs4_procedures[];
+
+#ifdef CONFIG_NFS_V4_2
+extern const u32 nfs42_maxsetxattr_overhead;
+extern const u32 nfs42_maxgetxattr_overhead;
+extern const u32 nfs42_maxlistxattrs_overhead;
+#endif
+
+struct nfs4_mount_data;
+
+/* callback_xdr.c */
+extern const struct svc_version nfs4_callback_version1;
+extern const struct svc_version nfs4_callback_version4;
+
+static inline void nfs4_stateid_copy(nfs4_stateid *dst, const nfs4_stateid *src)
+{
+	memcpy(dst->data, src->data, sizeof(dst->data));
+	dst->type = src->type;
+}
+
+static inline bool nfs4_stateid_match(const nfs4_stateid *dst, const nfs4_stateid *src)
+{
+	if (dst->type != src->type)
+		return false;
+	return memcmp(dst->data, src->data, sizeof(dst->data)) == 0;
+}
+
+static inline bool nfs4_stateid_match_other(const nfs4_stateid *dst, const nfs4_stateid *src)
+{
+	return memcmp(dst->other, src->other, NFS4_STATEID_OTHER_SIZE) == 0;
+}
+
+static inline bool nfs4_stateid_is_newer(const nfs4_stateid *s1, const nfs4_stateid *s2)
+{
+	return (s32)(be32_to_cpu(s1->seqid) - be32_to_cpu(s2->seqid)) > 0;
+}
+
+static inline bool nfs4_stateid_is_next(const nfs4_stateid *s1, const nfs4_stateid *s2)
+{
+	u32 seq1 = be32_to_cpu(s1->seqid);
+	u32 seq2 = be32_to_cpu(s2->seqid);
+
+	return seq2 == seq1 + 1U || (seq2 == 1U && seq1 == 0xffffffffU);
+}
+
+static inline bool nfs4_stateid_match_or_older(const nfs4_stateid *dst, const nfs4_stateid *src)
+{
+	return nfs4_stateid_match_other(dst, src) &&
+		!(src->seqid && nfs4_stateid_is_newer(dst, src));
+}
+
+static inline void nfs4_stateid_seqid_inc(nfs4_stateid *s1)
+{
+	u32 seqid = be32_to_cpu(s1->seqid);
+
+	if (++seqid == 0)
+		++seqid;
+	s1->seqid = cpu_to_be32(seqid);
+}
+
+static inline bool nfs4_valid_open_stateid(const struct nfs4_state *state)
+{
+	return test_bit(NFS_STATE_RECOVERY_FAILED, &state->flags) == 0;
+}
+
+static inline bool nfs4_state_match_open_stateid_other(const struct nfs4_state *state,
+		const nfs4_stateid *stateid)
+{
+	return test_bit(NFS_OPEN_STATE, &state->flags) &&
+		nfs4_stateid_match_other(&state->open_stateid, stateid);
+}
+
+/* nfs42xattr.c */
+#ifdef CONFIG_NFS_V4_2
+extern int __init nfs4_xattr_cache_init(void);
+extern void nfs4_xattr_cache_exit(void);
+extern void nfs4_xattr_cache_add(struct inode *inode, const char *name,
+				 const char *buf, struct page **pages,
+				 ssize_t buflen);
+extern void nfs4_xattr_cache_remove(struct inode *inode, const char *name);
+extern ssize_t nfs4_xattr_cache_get(struct inode *inode, const char *name,
+				char *buf, ssize_t buflen);
+extern void nfs4_xattr_cache_set_list(struct inode *inode, const char *buf,
+				      ssize_t buflen);
+extern ssize_t nfs4_xattr_cache_list(struct inode *inode, char *buf,
+				     ssize_t buflen);
+extern void nfs4_xattr_cache_zap(struct inode *inode);
+#else
+static inline void nfs4_xattr_cache_zap(struct inode *inode)
+{
+}
+#endif /* CONFIG_NFS_V4_2 */
+
+#else /* CONFIG_NFS_V4 */
+
+#define nfs4_close_state(a, b) do { } while (0)
+#define nfs4_close_sync(a, b) do { } while (0)
+#define nfs4_state_protect(a, b, c, d) do { } while (0)
+#define nfs4_state_protect_write(a, b, c, d) do { } while (0)
+
+
+#endif /* CONFIG_NFS_V4 */
+#endif /* __LINUX_FS_NFS_NFS4_FS.H */
diff --git a/fs/nfs/nfs4client.c b/fs/nfs/nfs4client.c
new file mode 100644
index 000000000..252c99c76
--- /dev/null
+++ b/fs/nfs/nfs4client.c
@@ -0,0 +1,1342 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2006 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+#include <linux/module.h>
+#include <linux/nfs_fs.h>
+#include <linux/nfs_mount.h>
+#include <linux/sunrpc/addr.h>
+#include <linux/sunrpc/auth.h>
+#include <linux/sunrpc/xprt.h>
+#include <linux/sunrpc/bc_xprt.h>
+#include <linux/sunrpc/rpc_pipe_fs.h>
+#include "internal.h"
+#include "callback.h"
+#include "delegation.h"
+#include "nfs4session.h"
+#include "nfs4idmap.h"
+#include "pnfs.h"
+#include "netns.h"
+
+#define NFSDBG_FACILITY		NFSDBG_CLIENT
+
+/*
+ * Get a unique NFSv4.0 callback identifier which will be used
+ * by the V4.0 callback service to lookup the nfs_client struct
+ */
+static int nfs_get_cb_ident_idr(struct nfs_client *clp, int minorversion)
+{
+	int ret = 0;
+	struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
+
+	if (clp->rpc_ops->version != 4 || minorversion != 0)
+		return ret;
+	idr_preload(GFP_KERNEL);
+	spin_lock(&nn->nfs_client_lock);
+	ret = idr_alloc(&nn->cb_ident_idr, clp, 1, 0, GFP_NOWAIT);
+	if (ret >= 0)
+		clp->cl_cb_ident = ret;
+	spin_unlock(&nn->nfs_client_lock);
+	idr_preload_end();
+	return ret < 0 ? ret : 0;
+}
+
+#ifdef CONFIG_NFS_V4_1
+/*
+ * Per auth flavor data server rpc clients
+ */
+struct nfs4_ds_server {
+	struct list_head	list;   /* ds_clp->cl_ds_clients */
+	struct rpc_clnt		*rpc_clnt;
+};
+
+/**
+ * nfs4_find_ds_client - Common lookup case for DS I/O
+ * @ds_clp: pointer to the DS's nfs_client
+ * @flavor: rpc auth flavour to match
+ */
+static struct nfs4_ds_server *
+nfs4_find_ds_client(struct nfs_client *ds_clp, rpc_authflavor_t flavor)
+{
+	struct nfs4_ds_server *dss;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(dss, &ds_clp->cl_ds_clients, list) {
+		if (dss->rpc_clnt->cl_auth->au_flavor != flavor)
+			continue;
+		goto out;
+	}
+	dss = NULL;
+out:
+	rcu_read_unlock();
+	return dss;
+}
+
+static struct nfs4_ds_server *
+nfs4_add_ds_client(struct nfs_client *ds_clp, rpc_authflavor_t flavor,
+			   struct nfs4_ds_server *new)
+{
+	struct nfs4_ds_server *dss;
+
+	spin_lock(&ds_clp->cl_lock);
+	list_for_each_entry(dss, &ds_clp->cl_ds_clients, list) {
+		if (dss->rpc_clnt->cl_auth->au_flavor != flavor)
+			continue;
+		goto out;
+	}
+	if (new)
+		list_add_rcu(&new->list, &ds_clp->cl_ds_clients);
+	dss = new;
+out:
+	spin_unlock(&ds_clp->cl_lock); /* need some lock to protect list */
+	return dss;
+}
+
+static struct nfs4_ds_server *
+nfs4_alloc_ds_server(struct nfs_client *ds_clp, rpc_authflavor_t flavor)
+{
+	struct nfs4_ds_server *dss;
+
+	dss = kmalloc(sizeof(*dss), GFP_NOFS);
+	if (dss == NULL)
+		return ERR_PTR(-ENOMEM);
+
+	dss->rpc_clnt = rpc_clone_client_set_auth(ds_clp->cl_rpcclient, flavor);
+	if (IS_ERR(dss->rpc_clnt)) {
+		int err = PTR_ERR(dss->rpc_clnt);
+		kfree (dss);
+		return ERR_PTR(err);
+	}
+	INIT_LIST_HEAD(&dss->list);
+
+	return dss;
+}
+
+static void
+nfs4_free_ds_server(struct nfs4_ds_server *dss)
+{
+	rpc_release_client(dss->rpc_clnt);
+	kfree(dss);
+}
+
+/**
+ * nfs4_find_or_create_ds_client - Find or create a DS rpc client
+ * @ds_clp: pointer to the DS's nfs_client
+ * @inode: pointer to the inode
+ *
+ * Find or create a DS rpc client with th MDS server rpc client auth flavor
+ * in the nfs_client cl_ds_clients list.
+ */
+struct rpc_clnt *
+nfs4_find_or_create_ds_client(struct nfs_client *ds_clp, struct inode *inode)
+{
+	struct nfs4_ds_server *dss, *new;
+	rpc_authflavor_t flavor = NFS_SERVER(inode)->client->cl_auth->au_flavor;
+
+	dss = nfs4_find_ds_client(ds_clp, flavor);
+	if (dss != NULL)
+		goto out;
+	new = nfs4_alloc_ds_server(ds_clp, flavor);
+	if (IS_ERR(new))
+		return ERR_CAST(new);
+	dss = nfs4_add_ds_client(ds_clp, flavor, new);
+	if (dss != new)
+		nfs4_free_ds_server(new);
+out:
+	return dss->rpc_clnt;
+}
+EXPORT_SYMBOL_GPL(nfs4_find_or_create_ds_client);
+
+static void
+nfs4_shutdown_ds_clients(struct nfs_client *clp)
+{
+	struct nfs4_ds_server *dss;
+
+	while (!list_empty(&clp->cl_ds_clients)) {
+		dss = list_entry(clp->cl_ds_clients.next,
+					struct nfs4_ds_server, list);
+		list_del(&dss->list);
+		rpc_shutdown_client(dss->rpc_clnt);
+		kfree (dss);
+	}
+}
+
+static void
+nfs4_cleanup_callback(struct nfs_client *clp)
+{
+	struct nfs4_copy_state *cp_state;
+
+	while (!list_empty(&clp->pending_cb_stateids)) {
+		cp_state = list_entry(clp->pending_cb_stateids.next,
+					struct nfs4_copy_state, copies);
+		list_del(&cp_state->copies);
+		kfree(cp_state);
+	}
+}
+
+void nfs41_shutdown_client(struct nfs_client *clp)
+{
+	if (nfs4_has_session(clp)) {
+		nfs4_cleanup_callback(clp);
+		nfs4_shutdown_ds_clients(clp);
+		nfs4_destroy_session(clp->cl_session);
+		nfs4_destroy_clientid(clp);
+	}
+
+}
+#endif	/* CONFIG_NFS_V4_1 */
+
+void nfs40_shutdown_client(struct nfs_client *clp)
+{
+	if (clp->cl_slot_tbl) {
+		nfs4_shutdown_slot_table(clp->cl_slot_tbl);
+		kfree(clp->cl_slot_tbl);
+	}
+}
+
+struct nfs_client *nfs4_alloc_client(const struct nfs_client_initdata *cl_init)
+{
+	char buf[INET6_ADDRSTRLEN + 1];
+	const char *ip_addr = cl_init->ip_addr;
+	struct nfs_client *clp = nfs_alloc_client(cl_init);
+	int err;
+
+	if (IS_ERR(clp))
+		return clp;
+
+	err = nfs_get_cb_ident_idr(clp, cl_init->minorversion);
+	if (err)
+		goto error;
+
+	if (cl_init->minorversion > NFS4_MAX_MINOR_VERSION) {
+		err = -EINVAL;
+		goto error;
+	}
+
+	spin_lock_init(&clp->cl_lock);
+	INIT_DELAYED_WORK(&clp->cl_renewd, nfs4_renew_state);
+	INIT_LIST_HEAD(&clp->cl_ds_clients);
+	rpc_init_wait_queue(&clp->cl_rpcwaitq, "NFS client");
+	clp->cl_state = 1 << NFS4CLNT_LEASE_EXPIRED;
+	clp->cl_mvops = nfs_v4_minor_ops[cl_init->minorversion];
+	clp->cl_mig_gen = 1;
+#if IS_ENABLED(CONFIG_NFS_V4_1)
+	init_waitqueue_head(&clp->cl_lock_waitq);
+#endif
+	INIT_LIST_HEAD(&clp->pending_cb_stateids);
+
+	if (cl_init->minorversion != 0)
+		__set_bit(NFS_CS_INFINITE_SLOTS, &clp->cl_flags);
+	__set_bit(NFS_CS_DISCRTRY, &clp->cl_flags);
+	__set_bit(NFS_CS_NO_RETRANS_TIMEOUT, &clp->cl_flags);
+
+	/*
+	 * Set up the connection to the server before we add add to the
+	 * global list.
+	 */
+	err = nfs_create_rpc_client(clp, cl_init, RPC_AUTH_GSS_KRB5I);
+	if (err == -EINVAL)
+		err = nfs_create_rpc_client(clp, cl_init, RPC_AUTH_UNIX);
+	if (err < 0)
+		goto error;
+
+	/* If no clientaddr= option was specified, find a usable cb address */
+	if (ip_addr == NULL) {
+		struct sockaddr_storage cb_addr;
+		struct sockaddr *sap = (struct sockaddr *)&cb_addr;
+
+		err = rpc_localaddr(clp->cl_rpcclient, sap, sizeof(cb_addr));
+		if (err < 0)
+			goto error;
+		err = rpc_ntop(sap, buf, sizeof(buf));
+		if (err < 0)
+			goto error;
+		ip_addr = (const char *)buf;
+	}
+	strlcpy(clp->cl_ipaddr, ip_addr, sizeof(clp->cl_ipaddr));
+
+	err = nfs_idmap_new(clp);
+	if (err < 0) {
+		dprintk("%s: failed to create idmapper. Error = %d\n",
+			__func__, err);
+		goto error;
+	}
+	__set_bit(NFS_CS_IDMAP, &clp->cl_res_state);
+	return clp;
+
+error:
+	nfs_free_client(clp);
+	return ERR_PTR(err);
+}
+
+/*
+ * Destroy the NFS4 callback service
+ */
+static void nfs4_destroy_callback(struct nfs_client *clp)
+{
+	if (__test_and_clear_bit(NFS_CS_CALLBACK, &clp->cl_res_state))
+		nfs_callback_down(clp->cl_mvops->minor_version, clp->cl_net);
+}
+
+static void nfs4_shutdown_client(struct nfs_client *clp)
+{
+	if (__test_and_clear_bit(NFS_CS_RENEWD, &clp->cl_res_state))
+		nfs4_kill_renewd(clp);
+	clp->cl_mvops->shutdown_client(clp);
+	nfs4_destroy_callback(clp);
+	if (__test_and_clear_bit(NFS_CS_IDMAP, &clp->cl_res_state))
+		nfs_idmap_delete(clp);
+
+	rpc_destroy_wait_queue(&clp->cl_rpcwaitq);
+	kfree(clp->cl_serverowner);
+	kfree(clp->cl_serverscope);
+	kfree(clp->cl_implid);
+	kfree(clp->cl_owner_id);
+}
+
+void nfs4_free_client(struct nfs_client *clp)
+{
+	nfs4_shutdown_client(clp);
+	nfs_free_client(clp);
+}
+
+/*
+ * Initialize the NFS4 callback service
+ */
+static int nfs4_init_callback(struct nfs_client *clp)
+{
+	struct rpc_xprt *xprt;
+	int error;
+
+	xprt = rcu_dereference_raw(clp->cl_rpcclient->cl_xprt);
+
+	if (nfs4_has_session(clp)) {
+		error = xprt_setup_backchannel(xprt, NFS41_BC_MIN_CALLBACKS);
+		if (error < 0)
+			return error;
+	}
+
+	error = nfs_callback_up(clp->cl_mvops->minor_version, xprt);
+	if (error < 0) {
+		dprintk("%s: failed to start callback. Error = %d\n",
+			__func__, error);
+		return error;
+	}
+	__set_bit(NFS_CS_CALLBACK, &clp->cl_res_state);
+
+	return 0;
+}
+
+/**
+ * nfs40_init_client - nfs_client initialization tasks for NFSv4.0
+ * @clp: nfs_client to initialize
+ *
+ * Returns zero on success, or a negative errno if some error occurred.
+ */
+int nfs40_init_client(struct nfs_client *clp)
+{
+	struct nfs4_slot_table *tbl;
+	int ret;
+
+	tbl = kzalloc(sizeof(*tbl), GFP_NOFS);
+	if (tbl == NULL)
+		return -ENOMEM;
+
+	ret = nfs4_setup_slot_table(tbl, NFS4_MAX_SLOT_TABLE,
+					"NFSv4.0 transport Slot table");
+	if (ret) {
+		nfs4_shutdown_slot_table(tbl);
+		kfree(tbl);
+		return ret;
+	}
+
+	clp->cl_slot_tbl = tbl;
+	return 0;
+}
+
+#if defined(CONFIG_NFS_V4_1)
+
+/**
+ * nfs41_init_client - nfs_client initialization tasks for NFSv4.1+
+ * @clp: nfs_client to initialize
+ *
+ * Returns zero on success, or a negative errno if some error occurred.
+ */
+int nfs41_init_client(struct nfs_client *clp)
+{
+	struct nfs4_session *session = NULL;
+
+	/*
+	 * Create the session and mark it expired.
+	 * When a SEQUENCE operation encounters the expired session
+	 * it will do session recovery to initialize it.
+	 */
+	session = nfs4_alloc_session(clp);
+	if (!session)
+		return -ENOMEM;
+
+	clp->cl_session = session;
+
+	/*
+	 * The create session reply races with the server back
+	 * channel probe. Mark the client NFS_CS_SESSION_INITING
+	 * so that the client back channel can find the
+	 * nfs_client struct
+	 */
+	nfs_mark_client_ready(clp, NFS_CS_SESSION_INITING);
+	return 0;
+}
+
+#endif	/* CONFIG_NFS_V4_1 */
+
+/*
+ * Initialize the minor version specific parts of an NFS4 client record
+ */
+static int nfs4_init_client_minor_version(struct nfs_client *clp)
+{
+	int ret;
+
+	ret = clp->cl_mvops->init_client(clp);
+	if (ret)
+		return ret;
+	return nfs4_init_callback(clp);
+}
+
+/**
+ * nfs4_init_client - Initialise an NFS4 client record
+ *
+ * @clp: nfs_client to initialise
+ * @cl_init: pointer to nfs_client_initdata
+ *
+ * Returns pointer to an NFS client, or an ERR_PTR value.
+ */
+struct nfs_client *nfs4_init_client(struct nfs_client *clp,
+				    const struct nfs_client_initdata *cl_init)
+{
+	struct nfs_client *old;
+	int error;
+
+	if (clp->cl_cons_state == NFS_CS_READY)
+		/* the client is initialised already */
+		return clp;
+
+	error = nfs4_init_client_minor_version(clp);
+	if (error < 0)
+		goto error;
+
+	error = nfs4_discover_server_trunking(clp, &old);
+	if (error < 0)
+		goto error;
+
+	if (clp != old) {
+		clp->cl_preserve_clid = true;
+		/*
+		 * Mark the client as having failed initialization so other
+		 * processes walking the nfs_client_list in nfs_match_client()
+		 * won't try to use it.
+		 */
+		nfs_mark_client_ready(clp, -EPERM);
+	}
+	clear_bit(NFS_CS_TSM_POSSIBLE, &clp->cl_flags);
+	nfs_put_client(clp);
+	return old;
+
+error:
+	nfs_mark_client_ready(clp, error);
+	nfs_put_client(clp);
+	return ERR_PTR(error);
+}
+
+/*
+ * SETCLIENTID just did a callback update with the callback ident in
+ * "drop," but server trunking discovery claims "drop" and "keep" are
+ * actually the same server.  Swap the callback IDs so that "keep"
+ * will continue to use the callback ident the server now knows about,
+ * and so that "keep"'s original callback ident is destroyed when
+ * "drop" is freed.
+ */
+static void nfs4_swap_callback_idents(struct nfs_client *keep,
+				      struct nfs_client *drop)
+{
+	struct nfs_net *nn = net_generic(keep->cl_net, nfs_net_id);
+	unsigned int save = keep->cl_cb_ident;
+
+	if (keep->cl_cb_ident == drop->cl_cb_ident)
+		return;
+
+	dprintk("%s: keeping callback ident %u and dropping ident %u\n",
+		__func__, keep->cl_cb_ident, drop->cl_cb_ident);
+
+	spin_lock(&nn->nfs_client_lock);
+
+	idr_replace(&nn->cb_ident_idr, keep, drop->cl_cb_ident);
+	keep->cl_cb_ident = drop->cl_cb_ident;
+
+	idr_replace(&nn->cb_ident_idr, drop, save);
+	drop->cl_cb_ident = save;
+
+	spin_unlock(&nn->nfs_client_lock);
+}
+
+static bool nfs4_match_client_owner_id(const struct nfs_client *clp1,
+		const struct nfs_client *clp2)
+{
+	if (clp1->cl_owner_id == NULL || clp2->cl_owner_id == NULL)
+		return true;
+	return strcmp(clp1->cl_owner_id, clp2->cl_owner_id) == 0;
+}
+
+static bool nfs4_same_verifier(nfs4_verifier *v1, nfs4_verifier *v2)
+{
+	return memcmp(v1->data, v2->data, sizeof(v1->data)) == 0;
+}
+
+static int nfs4_match_client(struct nfs_client  *pos,  struct nfs_client *new,
+			     struct nfs_client **prev, struct nfs_net *nn)
+{
+	int status;
+
+	if (pos->rpc_ops != new->rpc_ops)
+		return 1;
+
+	if (pos->cl_minorversion != new->cl_minorversion)
+		return 1;
+
+	/* If "pos" isn't marked ready, we can't trust the
+	 * remaining fields in "pos", especially the client
+	 * ID and serverowner fields.  Wait for CREATE_SESSION
+	 * to finish. */
+	if (pos->cl_cons_state > NFS_CS_READY) {
+		refcount_inc(&pos->cl_count);
+		spin_unlock(&nn->nfs_client_lock);
+
+		nfs_put_client(*prev);
+		*prev = pos;
+
+		status = nfs_wait_client_init_complete(pos);
+		spin_lock(&nn->nfs_client_lock);
+
+		if (status < 0)
+			return status;
+	}
+
+	if (pos->cl_cons_state != NFS_CS_READY)
+		return 1;
+
+	if (pos->cl_clientid != new->cl_clientid)
+		return 1;
+
+	/* NFSv4.1 always uses the uniform string, however someone
+	 * might switch the uniquifier string on us.
+	 */
+	if (!nfs4_match_client_owner_id(pos, new))
+		return 1;
+
+	return 0;
+}
+
+/**
+ * nfs40_walk_client_list - Find server that recognizes a client ID
+ *
+ * @new: nfs_client with client ID to test
+ * @result: OUT: found nfs_client, or new
+ * @cred: credential to use for trunking test
+ *
+ * Returns zero, a negative errno, or a negative NFS4ERR status.
+ * If zero is returned, an nfs_client pointer is planted in "result."
+ *
+ * NB: nfs40_walk_client_list() relies on the new nfs_client being
+ *     the last nfs_client on the list.
+ */
+int nfs40_walk_client_list(struct nfs_client *new,
+			   struct nfs_client **result,
+			   const struct cred *cred)
+{
+	struct nfs_net *nn = net_generic(new->cl_net, nfs_net_id);
+	struct nfs_client *pos, *prev = NULL;
+	struct nfs4_setclientid_res clid = {
+		.clientid	= new->cl_clientid,
+		.confirm	= new->cl_confirm,
+	};
+	int status = -NFS4ERR_STALE_CLIENTID;
+
+	spin_lock(&nn->nfs_client_lock);
+	list_for_each_entry(pos, &nn->nfs_client_list, cl_share_link) {
+
+		if (pos == new)
+			goto found;
+
+		status = nfs4_match_client(pos, new, &prev, nn);
+		if (status < 0)
+			goto out_unlock;
+		if (status != 0)
+			continue;
+		/*
+		 * We just sent a new SETCLIENTID, which should have
+		 * caused the server to return a new cl_confirm.  So if
+		 * cl_confirm is the same, then this is a different
+		 * server that just returned the same cl_confirm by
+		 * coincidence:
+		 */
+		if ((new != pos) && nfs4_same_verifier(&pos->cl_confirm,
+						       &new->cl_confirm))
+			continue;
+		/*
+		 * But if the cl_confirm's are different, then the only
+		 * way that a SETCLIENTID_CONFIRM to pos can succeed is
+		 * if new and pos point to the same server:
+		 */
+found:
+		refcount_inc(&pos->cl_count);
+		spin_unlock(&nn->nfs_client_lock);
+
+		nfs_put_client(prev);
+		prev = pos;
+
+		status = nfs4_proc_setclientid_confirm(pos, &clid, cred);
+		switch (status) {
+		case -NFS4ERR_STALE_CLIENTID:
+			break;
+		case 0:
+			nfs4_swap_callback_idents(pos, new);
+			pos->cl_confirm = new->cl_confirm;
+			nfs_mark_client_ready(pos, NFS_CS_READY);
+
+			prev = NULL;
+			*result = pos;
+			goto out;
+		case -ERESTARTSYS:
+		case -ETIMEDOUT:
+			/* The callback path may have been inadvertently
+			 * changed. Schedule recovery!
+			 */
+			nfs4_schedule_path_down_recovery(pos);
+		default:
+			goto out;
+		}
+
+		spin_lock(&nn->nfs_client_lock);
+	}
+out_unlock:
+	spin_unlock(&nn->nfs_client_lock);
+
+	/* No match found. The server lost our clientid */
+out:
+	nfs_put_client(prev);
+	return status;
+}
+
+#ifdef CONFIG_NFS_V4_1
+/*
+ * Returns true if the server major ids match
+ */
+bool
+nfs4_check_serverowner_major_id(struct nfs41_server_owner *o1,
+				struct nfs41_server_owner *o2)
+{
+	if (o1->major_id_sz != o2->major_id_sz)
+		return false;
+	return memcmp(o1->major_id, o2->major_id, o1->major_id_sz) == 0;
+}
+
+/*
+ * Returns true if the server scopes match
+ */
+static bool
+nfs4_check_server_scope(struct nfs41_server_scope *s1,
+			struct nfs41_server_scope *s2)
+{
+	if (s1->server_scope_sz != s2->server_scope_sz)
+		return false;
+	return memcmp(s1->server_scope, s2->server_scope,
+					s1->server_scope_sz) == 0;
+}
+
+/**
+ * nfs4_detect_session_trunking - Checks for session trunking.
+ * @clp:    original mount nfs_client
+ * @res:    result structure from an exchange_id using the original mount
+ *          nfs_client with a new multi_addr transport
+ * @xprt:   pointer to the transport to add.
+ *
+ * Called after a successful EXCHANGE_ID on a multi-addr connection.
+ * Upon success, add the transport.
+ *
+ * Returns zero on success, otherwise -EINVAL
+ *
+ * Note: since the exchange_id for the new multi_addr transport uses the
+ * same nfs_client from the original mount, the cl_owner_id is reused,
+ * so eir_clientowner is the same.
+ */
+int nfs4_detect_session_trunking(struct nfs_client *clp,
+				 struct nfs41_exchange_id_res *res,
+				 struct rpc_xprt *xprt)
+{
+	/* Check eir_clientid */
+	if (clp->cl_clientid != res->clientid)
+		goto out_err;
+
+	/* Check eir_server_owner so_major_id */
+	if (!nfs4_check_serverowner_major_id(clp->cl_serverowner,
+					     res->server_owner))
+		goto out_err;
+
+	/* Check eir_server_owner so_minor_id */
+	if (clp->cl_serverowner->minor_id != res->server_owner->minor_id)
+		goto out_err;
+
+	/* Check eir_server_scope */
+	if (!nfs4_check_server_scope(clp->cl_serverscope, res->server_scope))
+		goto out_err;
+
+	pr_info("NFS:  %s: Session trunking succeeded for %s\n",
+		clp->cl_hostname,
+		xprt->address_strings[RPC_DISPLAY_ADDR]);
+
+	return 0;
+out_err:
+	pr_info("NFS:  %s: Session trunking failed for %s\n", clp->cl_hostname,
+		xprt->address_strings[RPC_DISPLAY_ADDR]);
+
+	return -EINVAL;
+}
+
+/**
+ * nfs41_walk_client_list - Find nfs_client that matches a client/server owner
+ *
+ * @new: nfs_client with client ID to test
+ * @result: OUT: found nfs_client, or new
+ * @cred: credential to use for trunking test
+ *
+ * Returns zero, a negative errno, or a negative NFS4ERR status.
+ * If zero is returned, an nfs_client pointer is planted in "result."
+ *
+ * NB: nfs41_walk_client_list() relies on the new nfs_client being
+ *     the last nfs_client on the list.
+ */
+int nfs41_walk_client_list(struct nfs_client *new,
+			   struct nfs_client **result,
+			   const struct cred *cred)
+{
+	struct nfs_net *nn = net_generic(new->cl_net, nfs_net_id);
+	struct nfs_client *pos, *prev = NULL;
+	int status = -NFS4ERR_STALE_CLIENTID;
+
+	spin_lock(&nn->nfs_client_lock);
+	list_for_each_entry(pos, &nn->nfs_client_list, cl_share_link) {
+
+		if (pos == new)
+			goto found;
+
+		status = nfs4_match_client(pos, new, &prev, nn);
+		if (status < 0)
+			goto out;
+		if (status != 0)
+			continue;
+
+		/*
+		 * Note that session trunking is just a special subcase of
+		 * client id trunking. In either case, we want to fall back
+		 * to using the existing nfs_client.
+		 */
+		if (!nfs4_check_serverowner_major_id(pos->cl_serverowner,
+						     new->cl_serverowner))
+			continue;
+
+found:
+		refcount_inc(&pos->cl_count);
+		*result = pos;
+		status = 0;
+		break;
+	}
+
+out:
+	spin_unlock(&nn->nfs_client_lock);
+	nfs_put_client(prev);
+	return status;
+}
+#endif	/* CONFIG_NFS_V4_1 */
+
+static void nfs4_destroy_server(struct nfs_server *server)
+{
+	LIST_HEAD(freeme);
+
+	nfs_server_return_all_delegations(server);
+	unset_pnfs_layoutdriver(server);
+	nfs4_purge_state_owners(server, &freeme);
+	nfs4_free_state_owners(&freeme);
+}
+
+/*
+ * NFSv4.0 callback thread helper
+ *
+ * Find a client by callback identifier
+ */
+struct nfs_client *
+nfs4_find_client_ident(struct net *net, int cb_ident)
+{
+	struct nfs_client *clp;
+	struct nfs_net *nn = net_generic(net, nfs_net_id);
+
+	spin_lock(&nn->nfs_client_lock);
+	clp = idr_find(&nn->cb_ident_idr, cb_ident);
+	if (clp)
+		refcount_inc(&clp->cl_count);
+	spin_unlock(&nn->nfs_client_lock);
+	return clp;
+}
+
+#if defined(CONFIG_NFS_V4_1)
+/* Common match routine for v4.0 and v4.1 callback services */
+static bool nfs4_cb_match_client(const struct sockaddr *addr,
+		struct nfs_client *clp, u32 minorversion)
+{
+	struct sockaddr *clap = (struct sockaddr *)&clp->cl_addr;
+
+	/* Don't match clients that failed to initialise */
+	if (!(clp->cl_cons_state == NFS_CS_READY ||
+	    clp->cl_cons_state == NFS_CS_SESSION_INITING))
+		return false;
+
+	smp_rmb();
+
+	/* Match the version and minorversion */
+	if (clp->rpc_ops->version != 4 ||
+	    clp->cl_minorversion != minorversion)
+		return false;
+
+	/* Match only the IP address, not the port number */
+	return rpc_cmp_addr(addr, clap);
+}
+
+/*
+ * NFSv4.1 callback thread helper
+ * For CB_COMPOUND calls, find a client by IP address, protocol version,
+ * minorversion, and sessionID
+ *
+ * Returns NULL if no such client
+ */
+struct nfs_client *
+nfs4_find_client_sessionid(struct net *net, const struct sockaddr *addr,
+			   struct nfs4_sessionid *sid, u32 minorversion)
+{
+	struct nfs_client *clp;
+	struct nfs_net *nn = net_generic(net, nfs_net_id);
+
+	spin_lock(&nn->nfs_client_lock);
+	list_for_each_entry(clp, &nn->nfs_client_list, cl_share_link) {
+		if (!nfs4_cb_match_client(addr, clp, minorversion))
+			continue;
+
+		if (!nfs4_has_session(clp))
+			continue;
+
+		/* Match sessionid*/
+		if (memcmp(clp->cl_session->sess_id.data,
+		    sid->data, NFS4_MAX_SESSIONID_LEN) != 0)
+			continue;
+
+		refcount_inc(&clp->cl_count);
+		spin_unlock(&nn->nfs_client_lock);
+		return clp;
+	}
+	spin_unlock(&nn->nfs_client_lock);
+	return NULL;
+}
+
+#else /* CONFIG_NFS_V4_1 */
+
+struct nfs_client *
+nfs4_find_client_sessionid(struct net *net, const struct sockaddr *addr,
+			   struct nfs4_sessionid *sid, u32 minorversion)
+{
+	return NULL;
+}
+#endif /* CONFIG_NFS_V4_1 */
+
+/*
+ * Set up an NFS4 client
+ */
+static int nfs4_set_client(struct nfs_server *server,
+		const char *hostname,
+		const struct sockaddr *addr,
+		const size_t addrlen,
+		const char *ip_addr,
+		int proto, const struct rpc_timeout *timeparms,
+		u32 minorversion, unsigned int nconnect,
+		struct net *net)
+{
+	struct nfs_client_initdata cl_init = {
+		.hostname = hostname,
+		.addr = addr,
+		.addrlen = addrlen,
+		.ip_addr = ip_addr,
+		.nfs_mod = &nfs_v4,
+		.proto = proto,
+		.minorversion = minorversion,
+		.net = net,
+		.timeparms = timeparms,
+		.cred = server->cred,
+	};
+	struct nfs_client *clp;
+
+	if (minorversion == 0)
+		__set_bit(NFS_CS_REUSEPORT, &cl_init.init_flags);
+	if (proto == XPRT_TRANSPORT_TCP)
+		cl_init.nconnect = nconnect;
+
+	if (server->flags & NFS_MOUNT_NORESVPORT)
+		__set_bit(NFS_CS_NORESVPORT, &cl_init.init_flags);
+	if (server->options & NFS_OPTION_MIGRATION)
+		__set_bit(NFS_CS_MIGRATION, &cl_init.init_flags);
+	if (test_bit(NFS_MIG_TSM_POSSIBLE, &server->mig_status))
+		__set_bit(NFS_CS_TSM_POSSIBLE, &cl_init.init_flags);
+	server->port = rpc_get_port(addr);
+
+	/* Allocate or find a client reference we can use */
+	clp = nfs_get_client(&cl_init);
+	if (IS_ERR(clp))
+		return PTR_ERR(clp);
+
+	if (server->nfs_client == clp) {
+		nfs_put_client(clp);
+		return -ELOOP;
+	}
+
+	/*
+	 * Query for the lease time on clientid setup or renewal
+	 *
+	 * Note that this will be set on nfs_clients that were created
+	 * only for the DS role and did not set this bit, but now will
+	 * serve a dual role.
+	 */
+	set_bit(NFS_CS_CHECK_LEASE_TIME, &clp->cl_res_state);
+
+	server->nfs_client = clp;
+	return 0;
+}
+
+/*
+ * Set up a pNFS Data Server client.
+ *
+ * Return any existing nfs_client that matches server address,port,version
+ * and minorversion.
+ *
+ * For a new nfs_client, use a soft mount (default), a low retrans and a
+ * low timeout interval so that if a connection is lost, we retry through
+ * the MDS.
+ */
+struct nfs_client *nfs4_set_ds_client(struct nfs_server *mds_srv,
+		const struct sockaddr *ds_addr, int ds_addrlen,
+		int ds_proto, unsigned int ds_timeo, unsigned int ds_retrans,
+		u32 minor_version)
+{
+	struct rpc_timeout ds_timeout;
+	struct nfs_client *mds_clp = mds_srv->nfs_client;
+	struct nfs_client_initdata cl_init = {
+		.addr = ds_addr,
+		.addrlen = ds_addrlen,
+		.nodename = mds_clp->cl_rpcclient->cl_nodename,
+		.ip_addr = mds_clp->cl_ipaddr,
+		.nfs_mod = &nfs_v4,
+		.proto = ds_proto,
+		.minorversion = minor_version,
+		.net = mds_clp->cl_net,
+		.timeparms = &ds_timeout,
+		.cred = mds_srv->cred,
+	};
+	char buf[INET6_ADDRSTRLEN + 1];
+
+	if (rpc_ntop(ds_addr, buf, sizeof(buf)) <= 0)
+		return ERR_PTR(-EINVAL);
+	cl_init.hostname = buf;
+
+	if (mds_clp->cl_nconnect > 1 && ds_proto == XPRT_TRANSPORT_TCP)
+		cl_init.nconnect = mds_clp->cl_nconnect;
+
+	if (mds_srv->flags & NFS_MOUNT_NORESVPORT)
+		__set_bit(NFS_CS_NORESVPORT, &cl_init.init_flags);
+
+	/*
+	 * Set an authflavor equual to the MDS value. Use the MDS nfs_client
+	 * cl_ipaddr so as to use the same EXCHANGE_ID co_ownerid as the MDS
+	 * (section 13.1 RFC 5661).
+	 */
+	nfs_init_timeout_values(&ds_timeout, ds_proto, ds_timeo, ds_retrans);
+	return nfs_get_client(&cl_init);
+}
+EXPORT_SYMBOL_GPL(nfs4_set_ds_client);
+
+/*
+ * Session has been established, and the client marked ready.
+ * Limit the mount rsize, wsize and dtsize using negotiated fore
+ * channel attributes.
+ */
+static void nfs4_session_limit_rwsize(struct nfs_server *server)
+{
+#ifdef CONFIG_NFS_V4_1
+	struct nfs4_session *sess;
+	u32 server_resp_sz;
+	u32 server_rqst_sz;
+
+	if (!nfs4_has_session(server->nfs_client))
+		return;
+	sess = server->nfs_client->cl_session;
+	server_resp_sz = sess->fc_attrs.max_resp_sz - nfs41_maxread_overhead;
+	server_rqst_sz = sess->fc_attrs.max_rqst_sz - nfs41_maxwrite_overhead;
+
+	if (server->dtsize > server_resp_sz)
+		server->dtsize = server_resp_sz;
+	if (server->rsize > server_resp_sz)
+		server->rsize = server_resp_sz;
+	if (server->wsize > server_rqst_sz)
+		server->wsize = server_rqst_sz;
+#endif /* CONFIG_NFS_V4_1 */
+}
+
+/*
+ * Limit xattr sizes using the channel attributes.
+ */
+static void nfs4_session_limit_xasize(struct nfs_server *server)
+{
+#ifdef CONFIG_NFS_V4_2
+	struct nfs4_session *sess;
+	u32 server_gxa_sz;
+	u32 server_sxa_sz;
+	u32 server_lxa_sz;
+
+	if (!nfs4_has_session(server->nfs_client))
+		return;
+
+	sess = server->nfs_client->cl_session;
+
+	server_gxa_sz = sess->fc_attrs.max_resp_sz - nfs42_maxgetxattr_overhead;
+	server_sxa_sz = sess->fc_attrs.max_rqst_sz - nfs42_maxsetxattr_overhead;
+	server_lxa_sz = sess->fc_attrs.max_resp_sz -
+	    nfs42_maxlistxattrs_overhead;
+
+	if (server->gxasize > server_gxa_sz)
+		server->gxasize = server_gxa_sz;
+	if (server->sxasize > server_sxa_sz)
+		server->sxasize = server_sxa_sz;
+	if (server->lxasize > server_lxa_sz)
+		server->lxasize = server_lxa_sz;
+#endif
+}
+
+static int nfs4_server_common_setup(struct nfs_server *server,
+		struct nfs_fh *mntfh, bool auth_probe)
+{
+	struct nfs_fattr *fattr;
+	int error;
+
+	/* data servers support only a subset of NFSv4.1 */
+	if (is_ds_only_client(server->nfs_client))
+		return -EPROTONOSUPPORT;
+
+	fattr = nfs_alloc_fattr();
+	if (fattr == NULL)
+		return -ENOMEM;
+
+	/* We must ensure the session is initialised first */
+	error = nfs4_init_session(server->nfs_client);
+	if (error < 0)
+		goto out;
+
+	/* Set the basic capabilities */
+	server->caps |= server->nfs_client->cl_mvops->init_caps;
+	if (server->flags & NFS_MOUNT_NORDIRPLUS)
+			server->caps &= ~NFS_CAP_READDIRPLUS;
+	if (server->nfs_client->cl_proto == XPRT_TRANSPORT_RDMA)
+		server->caps &= ~NFS_CAP_READ_PLUS;
+	/*
+	 * Don't use NFS uid/gid mapping if we're using AUTH_SYS or lower
+	 * authentication.
+	 */
+	if (nfs4_disable_idmapping &&
+			server->client->cl_auth->au_flavor == RPC_AUTH_UNIX)
+		server->caps |= NFS_CAP_UIDGID_NOMAP;
+
+
+	/* Probe the root fh to retrieve its FSID and filehandle */
+	error = nfs4_get_rootfh(server, mntfh, auth_probe);
+	if (error < 0)
+		goto out;
+
+	dprintk("Server FSID: %llx:%llx\n",
+			(unsigned long long) server->fsid.major,
+			(unsigned long long) server->fsid.minor);
+	nfs_display_fhandle(mntfh, "Pseudo-fs root FH");
+
+	error = nfs_probe_fsinfo(server, mntfh, fattr);
+	if (error < 0)
+		goto out;
+
+	nfs4_session_limit_rwsize(server);
+	nfs4_session_limit_xasize(server);
+
+	if (server->namelen == 0 || server->namelen > NFS4_MAXNAMLEN)
+		server->namelen = NFS4_MAXNAMLEN;
+
+	nfs_server_insert_lists(server);
+	server->mount_time = jiffies;
+	server->destroy = nfs4_destroy_server;
+out:
+	nfs_free_fattr(fattr);
+	return error;
+}
+
+/*
+ * Create a version 4 volume record
+ */
+static int nfs4_init_server(struct nfs_server *server, struct fs_context *fc)
+{
+	struct nfs_fs_context *ctx = nfs_fc2context(fc);
+	struct rpc_timeout timeparms;
+	int error;
+
+	nfs_init_timeout_values(&timeparms, ctx->nfs_server.protocol,
+				ctx->timeo, ctx->retrans);
+
+	/* Initialise the client representation from the mount data */
+	server->flags = ctx->flags;
+	server->options = ctx->options;
+	server->auth_info = ctx->auth_info;
+
+	/* Use the first specified auth flavor. If this flavor isn't
+	 * allowed by the server, use the SECINFO path to try the
+	 * other specified flavors */
+	if (ctx->auth_info.flavor_len >= 1)
+		ctx->selected_flavor = ctx->auth_info.flavors[0];
+	else
+		ctx->selected_flavor = RPC_AUTH_UNIX;
+
+	/* Get a client record */
+	error = nfs4_set_client(server,
+				ctx->nfs_server.hostname,
+				&ctx->nfs_server.address,
+				ctx->nfs_server.addrlen,
+				ctx->client_address,
+				ctx->nfs_server.protocol,
+				&timeparms,
+				ctx->minorversion,
+				ctx->nfs_server.nconnect,
+				fc->net_ns);
+	if (error < 0)
+		return error;
+
+	if (ctx->rsize)
+		server->rsize = nfs_block_size(ctx->rsize, NULL);
+	if (ctx->wsize)
+		server->wsize = nfs_block_size(ctx->wsize, NULL);
+
+	server->acregmin = ctx->acregmin * HZ;
+	server->acregmax = ctx->acregmax * HZ;
+	server->acdirmin = ctx->acdirmin * HZ;
+	server->acdirmax = ctx->acdirmax * HZ;
+	server->port     = ctx->nfs_server.port;
+
+	return nfs_init_server_rpcclient(server, &timeparms,
+					 ctx->selected_flavor);
+}
+
+/*
+ * Create a version 4 volume record
+ * - keyed on server and FSID
+ */
+struct nfs_server *nfs4_create_server(struct fs_context *fc)
+{
+	struct nfs_fs_context *ctx = nfs_fc2context(fc);
+	struct nfs_server *server;
+	bool auth_probe;
+	int error;
+
+	server = nfs_alloc_server();
+	if (!server)
+		return ERR_PTR(-ENOMEM);
+
+	server->cred = get_cred(current_cred());
+
+	auth_probe = ctx->auth_info.flavor_len < 1;
+
+	/* set up the general RPC client */
+	error = nfs4_init_server(server, fc);
+	if (error < 0)
+		goto error;
+
+	error = nfs4_server_common_setup(server, ctx->mntfh, auth_probe);
+	if (error < 0)
+		goto error;
+
+	return server;
+
+error:
+	nfs_free_server(server);
+	return ERR_PTR(error);
+}
+
+/*
+ * Create an NFS4 referral server record
+ */
+struct nfs_server *nfs4_create_referral_server(struct fs_context *fc)
+{
+	struct nfs_fs_context *ctx = nfs_fc2context(fc);
+	struct nfs_client *parent_client;
+	struct nfs_server *server, *parent_server;
+	bool auth_probe;
+	int error;
+
+	server = nfs_alloc_server();
+	if (!server)
+		return ERR_PTR(-ENOMEM);
+
+	parent_server = NFS_SB(ctx->clone_data.sb);
+	parent_client = parent_server->nfs_client;
+
+	server->cred = get_cred(parent_server->cred);
+
+	/* Initialise the client representation from the parent server */
+	nfs_server_copy_userdata(server, parent_server);
+
+	/* Get a client representation */
+#if IS_ENABLED(CONFIG_SUNRPC_XPRT_RDMA)
+	rpc_set_port(&ctx->nfs_server.address, NFS_RDMA_PORT);
+	error = nfs4_set_client(server,
+				ctx->nfs_server.hostname,
+				&ctx->nfs_server.address,
+				ctx->nfs_server.addrlen,
+				parent_client->cl_ipaddr,
+				XPRT_TRANSPORT_RDMA,
+				parent_server->client->cl_timeout,
+				parent_client->cl_mvops->minor_version,
+				parent_client->cl_nconnect,
+				parent_client->cl_net);
+	if (!error)
+		goto init_server;
+#endif	/* IS_ENABLED(CONFIG_SUNRPC_XPRT_RDMA) */
+
+	rpc_set_port(&ctx->nfs_server.address, NFS_PORT);
+	error = nfs4_set_client(server,
+				ctx->nfs_server.hostname,
+				&ctx->nfs_server.address,
+				ctx->nfs_server.addrlen,
+				parent_client->cl_ipaddr,
+				XPRT_TRANSPORT_TCP,
+				parent_server->client->cl_timeout,
+				parent_client->cl_mvops->minor_version,
+				parent_client->cl_nconnect,
+				parent_client->cl_net);
+	if (error < 0)
+		goto error;
+
+#if IS_ENABLED(CONFIG_SUNRPC_XPRT_RDMA)
+init_server:
+#endif
+	error = nfs_init_server_rpcclient(server, parent_server->client->cl_timeout,
+					  ctx->selected_flavor);
+	if (error < 0)
+		goto error;
+
+	auth_probe = parent_server->auth_info.flavor_len < 1;
+
+	error = nfs4_server_common_setup(server, ctx->mntfh, auth_probe);
+	if (error < 0)
+		goto error;
+
+	return server;
+
+error:
+	nfs_free_server(server);
+	return ERR_PTR(error);
+}
+
+/*
+ * Grab the destination's particulars, including lease expiry time.
+ *
+ * Returns zero if probe succeeded and retrieved FSID matches the FSID
+ * we have cached.
+ */
+static int nfs_probe_destination(struct nfs_server *server)
+{
+	struct inode *inode = d_inode(server->super->s_root);
+	struct nfs_fattr *fattr;
+	int error;
+
+	fattr = nfs_alloc_fattr();
+	if (fattr == NULL)
+		return -ENOMEM;
+
+	/* Sanity: the probe won't work if the destination server
+	 * does not recognize the migrated FH. */
+	error = nfs_probe_fsinfo(server, NFS_FH(inode), fattr);
+
+	nfs_free_fattr(fattr);
+	return error;
+}
+
+/**
+ * nfs4_update_server - Move an nfs_server to a different nfs_client
+ *
+ * @server: represents FSID to be moved
+ * @hostname: new end-point's hostname
+ * @sap: new end-point's socket address
+ * @salen: size of "sap"
+ * @net: net namespace
+ *
+ * The nfs_server must be quiescent before this function is invoked.
+ * Either its session is drained (NFSv4.1+), or its transport is
+ * plugged and drained (NFSv4.0).
+ *
+ * Returns zero on success, or a negative errno value.
+ */
+int nfs4_update_server(struct nfs_server *server, const char *hostname,
+		       struct sockaddr *sap, size_t salen, struct net *net)
+{
+	struct nfs_client *clp = server->nfs_client;
+	struct rpc_clnt *clnt = server->client;
+	struct xprt_create xargs = {
+		.ident		= clp->cl_proto,
+		.net		= net,
+		.dstaddr	= sap,
+		.addrlen	= salen,
+		.servername	= hostname,
+	};
+	char buf[INET6_ADDRSTRLEN + 1];
+	struct sockaddr_storage address;
+	struct sockaddr *localaddr = (struct sockaddr *)&address;
+	int error;
+
+	error = rpc_switch_client_transport(clnt, &xargs, clnt->cl_timeout);
+	if (error != 0)
+		return error;
+
+	error = rpc_localaddr(clnt, localaddr, sizeof(address));
+	if (error != 0)
+		return error;
+
+	if (rpc_ntop(localaddr, buf, sizeof(buf)) == 0)
+		return -EAFNOSUPPORT;
+
+	nfs_server_remove_lists(server);
+	set_bit(NFS_MIG_TSM_POSSIBLE, &server->mig_status);
+	error = nfs4_set_client(server, hostname, sap, salen, buf,
+				clp->cl_proto, clnt->cl_timeout,
+				clp->cl_minorversion,
+				clp->cl_nconnect, net);
+	clear_bit(NFS_MIG_TSM_POSSIBLE, &server->mig_status);
+	if (error != 0) {
+		nfs_server_insert_lists(server);
+		return error;
+	}
+	nfs_put_client(clp);
+
+	if (server->nfs_client->cl_hostname == NULL) {
+		server->nfs_client->cl_hostname = kstrdup(hostname, GFP_KERNEL);
+		if (server->nfs_client->cl_hostname == NULL)
+			return -ENOMEM;
+	}
+	nfs_server_insert_lists(server);
+
+	return nfs_probe_destination(server);
+}
diff --git a/fs/nfs/nfs4file.c b/fs/nfs/nfs4file.c
new file mode 100644
index 000000000..70cd0d764
--- /dev/null
+++ b/fs/nfs/nfs4file.c
@@ -0,0 +1,470 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  linux/fs/nfs/file.c
+ *
+ *  Copyright (C) 1992  Rick Sladkey
+ */
+#include <linux/fs.h>
+#include <linux/file.h>
+#include <linux/falloc.h>
+#include <linux/mount.h>
+#include <linux/nfs_fs.h>
+#include <linux/nfs_ssc.h>
+#include "delegation.h"
+#include "internal.h"
+#include "iostat.h"
+#include "fscache.h"
+#include "pnfs.h"
+
+#include "nfstrace.h"
+
+#ifdef CONFIG_NFS_V4_2
+#include "nfs42.h"
+#endif
+
+#define NFSDBG_FACILITY		NFSDBG_FILE
+
+static int
+nfs4_file_open(struct inode *inode, struct file *filp)
+{
+	struct nfs_open_context *ctx;
+	struct dentry *dentry = file_dentry(filp);
+	struct dentry *parent = NULL;
+	struct inode *dir;
+	unsigned openflags = filp->f_flags;
+	fmode_t f_mode;
+	struct iattr attr;
+	int err;
+
+	/*
+	 * If no cached dentry exists or if it's negative, NFSv4 handled the
+	 * opens in ->lookup() or ->create().
+	 *
+	 * We only get this far for a cached positive dentry.  We skipped
+	 * revalidation, so handle it here by dropping the dentry and returning
+	 * -EOPENSTALE.  The VFS will retry the lookup/create/open.
+	 */
+
+	dprintk("NFS: open file(%pd2)\n", dentry);
+
+	err = nfs_check_flags(openflags);
+	if (err)
+		return err;
+
+	f_mode = filp->f_mode;
+	if ((openflags & O_ACCMODE) == 3)
+		f_mode |= flags_to_mode(openflags);
+
+	/* We can't create new files here */
+	openflags &= ~(O_CREAT|O_EXCL);
+
+	parent = dget_parent(dentry);
+	dir = d_inode(parent);
+
+	ctx = alloc_nfs_open_context(file_dentry(filp), f_mode, filp);
+	err = PTR_ERR(ctx);
+	if (IS_ERR(ctx))
+		goto out;
+
+	attr.ia_valid = ATTR_OPEN;
+	if (openflags & O_TRUNC) {
+		attr.ia_valid |= ATTR_SIZE;
+		attr.ia_size = 0;
+		filemap_write_and_wait(inode->i_mapping);
+	}
+
+	inode = NFS_PROTO(dir)->open_context(dir, ctx, openflags, &attr, NULL);
+	if (IS_ERR(inode)) {
+		err = PTR_ERR(inode);
+		switch (err) {
+		default:
+			goto out_put_ctx;
+		case -ENOENT:
+		case -ESTALE:
+		case -EISDIR:
+		case -ENOTDIR:
+		case -ELOOP:
+			goto out_drop;
+		}
+	}
+	if (inode != d_inode(dentry))
+		goto out_drop;
+
+	nfs_file_set_open_context(filp, ctx);
+	nfs_fscache_open_file(inode, filp);
+	err = 0;
+
+out_put_ctx:
+	put_nfs_open_context(ctx);
+out:
+	dput(parent);
+	return err;
+
+out_drop:
+	d_drop(dentry);
+	err = -EOPENSTALE;
+	goto out_put_ctx;
+}
+
+/*
+ * Flush all dirty pages, and check for write errors.
+ */
+static int
+nfs4_file_flush(struct file *file, fl_owner_t id)
+{
+	struct inode	*inode = file_inode(file);
+	errseq_t since;
+
+	dprintk("NFS: flush(%pD2)\n", file);
+
+	nfs_inc_stats(inode, NFSIOS_VFSFLUSH);
+	if ((file->f_mode & FMODE_WRITE) == 0)
+		return 0;
+
+	/*
+	 * If we're holding a write delegation, then check if we're required
+	 * to flush the i/o on close. If not, then just start the i/o now.
+	 */
+	if (!nfs4_delegation_flush_on_close(inode))
+		return filemap_fdatawrite(file->f_mapping);
+
+	/* Flush writes to the server and return any errors */
+	since = filemap_sample_wb_err(file->f_mapping);
+	nfs_wb_all(inode);
+	return filemap_check_wb_err(file->f_mapping, since);
+}
+
+#ifdef CONFIG_NFS_V4_2
+static ssize_t __nfs4_copy_file_range(struct file *file_in, loff_t pos_in,
+				      struct file *file_out, loff_t pos_out,
+				      size_t count, unsigned int flags)
+{
+	struct nfs42_copy_notify_res *cn_resp = NULL;
+	struct nl4_server *nss = NULL;
+	nfs4_stateid *cnrs = NULL;
+	ssize_t ret;
+	bool sync = false;
+
+	/* Only offload copy if superblock is the same */
+	if (file_in->f_op != &nfs4_file_operations)
+		return -EXDEV;
+	if (!nfs_server_capable(file_inode(file_out), NFS_CAP_COPY) ||
+	    !nfs_server_capable(file_inode(file_in), NFS_CAP_COPY))
+		return -EOPNOTSUPP;
+	if (file_inode(file_in) == file_inode(file_out))
+		return -EOPNOTSUPP;
+	/* if the copy size if smaller than 2 RPC payloads, make it
+	 * synchronous
+	 */
+	if (count <= 2 * NFS_SERVER(file_inode(file_in))->rsize)
+		sync = true;
+retry:
+	if (!nfs42_files_from_same_server(file_in, file_out)) {
+		/* for inter copy, if copy size if smaller than 12 RPC
+		 * payloads, fallback to traditional copy. There are
+		 * 14 RPCs during an NFSv4.x mount between source/dest
+		 * servers.
+		 */
+		if (sync ||
+			count <= 14 * NFS_SERVER(file_inode(file_in))->rsize)
+			return -EOPNOTSUPP;
+		cn_resp = kzalloc(sizeof(struct nfs42_copy_notify_res),
+				GFP_NOFS);
+		if (unlikely(cn_resp == NULL))
+			return -ENOMEM;
+
+		ret = nfs42_proc_copy_notify(file_in, file_out, cn_resp);
+		if (ret) {
+			ret = -EOPNOTSUPP;
+			goto out;
+		}
+		nss = &cn_resp->cnr_src;
+		cnrs = &cn_resp->cnr_stateid;
+	}
+	ret = nfs42_proc_copy(file_in, pos_in, file_out, pos_out, count,
+				nss, cnrs, sync);
+out:
+	if (!nfs42_files_from_same_server(file_in, file_out))
+		kfree(cn_resp);
+	if (ret == -EAGAIN)
+		goto retry;
+	return ret;
+}
+
+static ssize_t nfs4_copy_file_range(struct file *file_in, loff_t pos_in,
+				    struct file *file_out, loff_t pos_out,
+				    size_t count, unsigned int flags)
+{
+	ssize_t ret;
+
+	ret = __nfs4_copy_file_range(file_in, pos_in, file_out, pos_out, count,
+				     flags);
+	if (ret == -EOPNOTSUPP || ret == -EXDEV)
+		ret = generic_copy_file_range(file_in, pos_in, file_out,
+					      pos_out, count, flags);
+	return ret;
+}
+
+static loff_t nfs4_file_llseek(struct file *filep, loff_t offset, int whence)
+{
+	loff_t ret;
+
+	switch (whence) {
+	case SEEK_HOLE:
+	case SEEK_DATA:
+		ret = nfs42_proc_llseek(filep, offset, whence);
+		if (ret != -EOPNOTSUPP)
+			return ret;
+		fallthrough;
+	default:
+		return nfs_file_llseek(filep, offset, whence);
+	}
+}
+
+static long nfs42_fallocate(struct file *filep, int mode, loff_t offset, loff_t len)
+{
+	struct inode *inode = file_inode(filep);
+	long ret;
+
+	if (!S_ISREG(inode->i_mode))
+		return -EOPNOTSUPP;
+
+	if ((mode != 0) && (mode != (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE)))
+		return -EOPNOTSUPP;
+
+	ret = inode_newsize_ok(inode, offset + len);
+	if (ret < 0)
+		return ret;
+
+	if (mode & FALLOC_FL_PUNCH_HOLE)
+		return nfs42_proc_deallocate(filep, offset, len);
+	return nfs42_proc_allocate(filep, offset, len);
+}
+
+static loff_t nfs42_remap_file_range(struct file *src_file, loff_t src_off,
+		struct file *dst_file, loff_t dst_off, loff_t count,
+		unsigned int remap_flags)
+{
+	struct inode *dst_inode = file_inode(dst_file);
+	struct nfs_server *server = NFS_SERVER(dst_inode);
+	struct inode *src_inode = file_inode(src_file);
+	unsigned int bs = server->clone_blksize;
+	bool same_inode = false;
+	int ret;
+
+	/* NFS does not support deduplication. */
+	if (remap_flags & REMAP_FILE_DEDUP)
+		return -EOPNOTSUPP;
+
+	if (remap_flags & ~REMAP_FILE_ADVISORY)
+		return -EINVAL;
+
+	if (IS_SWAPFILE(dst_inode) || IS_SWAPFILE(src_inode))
+		return -ETXTBSY;
+
+	/* check alignment w.r.t. clone_blksize */
+	ret = -EINVAL;
+	if (bs) {
+		if (!IS_ALIGNED(src_off, bs) || !IS_ALIGNED(dst_off, bs))
+			goto out;
+		if (!IS_ALIGNED(count, bs) && i_size_read(src_inode) != (src_off + count))
+			goto out;
+	}
+
+	if (src_inode == dst_inode)
+		same_inode = true;
+
+	/* XXX: do we lock at all? what if server needs CB_RECALL_LAYOUT? */
+	if (same_inode) {
+		inode_lock(src_inode);
+	} else if (dst_inode < src_inode) {
+		inode_lock_nested(dst_inode, I_MUTEX_PARENT);
+		inode_lock_nested(src_inode, I_MUTEX_CHILD);
+	} else {
+		inode_lock_nested(src_inode, I_MUTEX_PARENT);
+		inode_lock_nested(dst_inode, I_MUTEX_CHILD);
+	}
+
+	/* flush all pending writes on both src and dst so that server
+	 * has the latest data */
+	ret = nfs_sync_inode(src_inode);
+	if (ret)
+		goto out_unlock;
+	ret = nfs_sync_inode(dst_inode);
+	if (ret)
+		goto out_unlock;
+
+	ret = nfs42_proc_clone(src_file, dst_file, src_off, dst_off, count);
+
+	/* truncate inode page cache of the dst range so that future reads can fetch
+	 * new data from server */
+	if (!ret)
+		truncate_inode_pages_range(&dst_inode->i_data, dst_off, dst_off + count - 1);
+
+out_unlock:
+	if (same_inode) {
+		inode_unlock(src_inode);
+	} else if (dst_inode < src_inode) {
+		inode_unlock(src_inode);
+		inode_unlock(dst_inode);
+	} else {
+		inode_unlock(dst_inode);
+		inode_unlock(src_inode);
+	}
+out:
+	return ret < 0 ? ret : count;
+}
+
+static int read_name_gen = 1;
+#define SSC_READ_NAME_BODY "ssc_read_%d"
+
+static struct file *__nfs42_ssc_open(struct vfsmount *ss_mnt,
+		struct nfs_fh *src_fh, nfs4_stateid *stateid)
+{
+	struct nfs_fattr *fattr = nfs_alloc_fattr();
+	struct file *filep, *res;
+	struct nfs_server *server;
+	struct inode *r_ino = NULL;
+	struct nfs_open_context *ctx;
+	struct nfs4_state_owner *sp;
+	char *read_name = NULL;
+	int len, status = 0;
+
+	server = NFS_SERVER(ss_mnt->mnt_root->d_inode);
+
+	if (!fattr)
+		return ERR_PTR(-ENOMEM);
+
+	status = nfs4_proc_getattr(server, src_fh, fattr, NULL, NULL);
+	if (status < 0) {
+		res = ERR_PTR(status);
+		goto out;
+	}
+
+	if (!S_ISREG(fattr->mode)) {
+		res = ERR_PTR(-EBADF);
+		goto out;
+	}
+
+	res = ERR_PTR(-ENOMEM);
+	len = strlen(SSC_READ_NAME_BODY) + 16;
+	read_name = kzalloc(len, GFP_NOFS);
+	if (read_name == NULL)
+		goto out;
+	snprintf(read_name, len, SSC_READ_NAME_BODY, read_name_gen++);
+
+	r_ino = nfs_fhget(ss_mnt->mnt_root->d_inode->i_sb, src_fh, fattr,
+			NULL);
+	if (IS_ERR(r_ino)) {
+		res = ERR_CAST(r_ino);
+		goto out_free_name;
+	}
+
+	filep = alloc_file_pseudo(r_ino, ss_mnt, read_name, FMODE_READ,
+				     r_ino->i_fop);
+	if (IS_ERR(filep)) {
+		res = ERR_CAST(filep);
+		iput(r_ino);
+		goto out_free_name;
+	}
+	filep->f_mode |= FMODE_READ;
+
+	ctx = alloc_nfs_open_context(filep->f_path.dentry, filep->f_mode,
+					filep);
+	if (IS_ERR(ctx)) {
+		res = ERR_CAST(ctx);
+		goto out_filep;
+	}
+
+	res = ERR_PTR(-EINVAL);
+	sp = nfs4_get_state_owner(server, ctx->cred, GFP_KERNEL);
+	if (sp == NULL)
+		goto out_ctx;
+
+	ctx->state = nfs4_get_open_state(r_ino, sp);
+	if (ctx->state == NULL)
+		goto out_stateowner;
+
+	set_bit(NFS_SRV_SSC_COPY_STATE, &ctx->state->flags);
+	memcpy(&ctx->state->open_stateid.other, &stateid->other,
+	       NFS4_STATEID_OTHER_SIZE);
+	update_open_stateid(ctx->state, stateid, NULL, filep->f_mode);
+	set_bit(NFS_OPEN_STATE, &ctx->state->flags);
+
+	nfs_file_set_open_context(filep, ctx);
+	put_nfs_open_context(ctx);
+
+	file_ra_state_init(&filep->f_ra, filep->f_mapping->host->i_mapping);
+	res = filep;
+out_free_name:
+	kfree(read_name);
+out:
+	nfs_free_fattr(fattr);
+	return res;
+out_stateowner:
+	nfs4_put_state_owner(sp);
+out_ctx:
+	put_nfs_open_context(ctx);
+out_filep:
+	fput(filep);
+	goto out_free_name;
+}
+
+static void __nfs42_ssc_close(struct file *filep)
+{
+	struct nfs_open_context *ctx = nfs_file_open_context(filep);
+
+	ctx->state->flags = 0;
+}
+
+static const struct nfs4_ssc_client_ops nfs4_ssc_clnt_ops_tbl = {
+	.sco_open = __nfs42_ssc_open,
+	.sco_close = __nfs42_ssc_close,
+};
+
+/**
+ * nfs42_ssc_register_ops - Wrapper to register NFS_V4 ops in nfs_common
+ *
+ * Return values:
+ *   None
+ */
+void nfs42_ssc_register_ops(void)
+{
+	nfs42_ssc_register(&nfs4_ssc_clnt_ops_tbl);
+}
+
+/**
+ * nfs42_ssc_unregister_ops - wrapper to un-register NFS_V4 ops in nfs_common
+ *
+ * Return values:
+ *   None.
+ */
+void nfs42_ssc_unregister_ops(void)
+{
+	nfs42_ssc_unregister(&nfs4_ssc_clnt_ops_tbl);
+}
+#endif /* CONFIG_NFS_V4_2 */
+
+const struct file_operations nfs4_file_operations = {
+	.read_iter	= nfs_file_read,
+	.write_iter	= nfs_file_write,
+	.mmap		= nfs_file_mmap,
+	.open		= nfs4_file_open,
+	.flush		= nfs4_file_flush,
+	.release	= nfs_file_release,
+	.fsync		= nfs_file_fsync,
+	.lock		= nfs_lock,
+	.flock		= nfs_flock,
+	.splice_read	= generic_file_splice_read,
+	.splice_write	= iter_file_splice_write,
+	.check_flags	= nfs_check_flags,
+	.setlease	= simple_nosetlease,
+#ifdef CONFIG_NFS_V4_2
+	.copy_file_range = nfs4_copy_file_range,
+	.llseek		= nfs4_file_llseek,
+	.fallocate	= nfs42_fallocate,
+	.remap_file_range = nfs42_remap_file_range,
+#else
+	.llseek		= nfs_file_llseek,
+#endif
+};
diff --git a/fs/nfs/nfs4getroot.c b/fs/nfs/nfs4getroot.c
new file mode 100644
index 000000000..1a69479a3
--- /dev/null
+++ b/fs/nfs/nfs4getroot.c
@@ -0,0 +1,41 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+* Copyright (C) 2006 Red Hat, Inc. All Rights Reserved.
+* Written by David Howells (dhowells@redhat.com)
+*/
+
+#include <linux/nfs_fs.h>
+#include "nfs4_fs.h"
+#include "internal.h"
+
+#define NFSDBG_FACILITY		NFSDBG_CLIENT
+
+int nfs4_get_rootfh(struct nfs_server *server, struct nfs_fh *mntfh, bool auth_probe)
+{
+	struct nfs_fsinfo fsinfo;
+	int ret = -ENOMEM;
+
+	fsinfo.fattr = nfs_alloc_fattr();
+	if (fsinfo.fattr == NULL)
+		goto out;
+
+	/* Start by getting the root filehandle from the server */
+	ret = nfs4_proc_get_rootfh(server, mntfh, &fsinfo, auth_probe);
+	if (ret < 0) {
+		dprintk("nfs4_get_rootfh: getroot error = %d\n", -ret);
+		goto out;
+	}
+
+	if (!(fsinfo.fattr->valid & NFS_ATTR_FATTR_TYPE)
+			|| !S_ISDIR(fsinfo.fattr->mode)) {
+		printk(KERN_ERR "nfs4_get_rootfh:"
+		       " getroot encountered non-directory\n");
+		ret = -ENOTDIR;
+		goto out;
+	}
+
+	memcpy(&server->fsid, &fsinfo.fattr->fsid, sizeof(server->fsid));
+out:
+	nfs_free_fattr(fsinfo.fattr);
+	return ret;
+}
diff --git a/fs/nfs/nfs4idmap.c b/fs/nfs/nfs4idmap.c
new file mode 100644
index 000000000..ec6afd3c4
--- /dev/null
+++ b/fs/nfs/nfs4idmap.c
@@ -0,0 +1,806 @@
+/*
+ * fs/nfs/idmap.c
+ *
+ *  UID and GID to name mapping for clients.
+ *
+ *  Copyright (c) 2002 The Regents of the University of Michigan.
+ *  All rights reserved.
+ *
+ *  Marius Aamodt Eriksen <marius@umich.edu>
+ *
+ *  Redistribution and use in source and binary forms, with or without
+ *  modification, are permitted provided that the following conditions
+ *  are met:
+ *
+ *  1. Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *  2. Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *  3. Neither the name of the University nor the names of its
+ *     contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+ *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+#include <linux/types.h>
+#include <linux/parser.h>
+#include <linux/fs.h>
+#include <net/net_namespace.h>
+#include <linux/sunrpc/rpc_pipe_fs.h>
+#include <linux/nfs_fs.h>
+#include <linux/nfs_fs_sb.h>
+#include <linux/key.h>
+#include <linux/keyctl.h>
+#include <linux/key-type.h>
+#include <keys/user-type.h>
+#include <keys/request_key_auth-type.h>
+#include <linux/module.h>
+#include <linux/user_namespace.h>
+
+#include "internal.h"
+#include "netns.h"
+#include "nfs4idmap.h"
+#include "nfs4trace.h"
+
+#define NFS_UINT_MAXLEN 11
+
+static const struct cred *id_resolver_cache;
+static struct key_type key_type_id_resolver_legacy;
+
+struct idmap_legacy_upcalldata {
+	struct rpc_pipe_msg pipe_msg;
+	struct idmap_msg idmap_msg;
+	struct key	*authkey;
+	struct idmap *idmap;
+};
+
+struct idmap {
+	struct rpc_pipe_dir_object idmap_pdo;
+	struct rpc_pipe		*idmap_pipe;
+	struct idmap_legacy_upcalldata *idmap_upcall_data;
+	struct mutex		idmap_mutex;
+	struct user_namespace	*user_ns;
+};
+
+static struct user_namespace *idmap_userns(const struct idmap *idmap)
+{
+	if (idmap && idmap->user_ns)
+		return idmap->user_ns;
+	return &init_user_ns;
+}
+
+/**
+ * nfs_fattr_init_names - initialise the nfs_fattr owner_name/group_name fields
+ * @fattr: fully initialised struct nfs_fattr
+ * @owner_name: owner name string cache
+ * @group_name: group name string cache
+ */
+void nfs_fattr_init_names(struct nfs_fattr *fattr,
+		struct nfs4_string *owner_name,
+		struct nfs4_string *group_name)
+{
+	fattr->owner_name = owner_name;
+	fattr->group_name = group_name;
+}
+
+static void nfs_fattr_free_owner_name(struct nfs_fattr *fattr)
+{
+	fattr->valid &= ~NFS_ATTR_FATTR_OWNER_NAME;
+	kfree(fattr->owner_name->data);
+}
+
+static void nfs_fattr_free_group_name(struct nfs_fattr *fattr)
+{
+	fattr->valid &= ~NFS_ATTR_FATTR_GROUP_NAME;
+	kfree(fattr->group_name->data);
+}
+
+static bool nfs_fattr_map_owner_name(struct nfs_server *server, struct nfs_fattr *fattr)
+{
+	struct nfs4_string *owner = fattr->owner_name;
+	kuid_t uid;
+
+	if (!(fattr->valid & NFS_ATTR_FATTR_OWNER_NAME))
+		return false;
+	if (nfs_map_name_to_uid(server, owner->data, owner->len, &uid) == 0) {
+		fattr->uid = uid;
+		fattr->valid |= NFS_ATTR_FATTR_OWNER;
+	}
+	return true;
+}
+
+static bool nfs_fattr_map_group_name(struct nfs_server *server, struct nfs_fattr *fattr)
+{
+	struct nfs4_string *group = fattr->group_name;
+	kgid_t gid;
+
+	if (!(fattr->valid & NFS_ATTR_FATTR_GROUP_NAME))
+		return false;
+	if (nfs_map_group_to_gid(server, group->data, group->len, &gid) == 0) {
+		fattr->gid = gid;
+		fattr->valid |= NFS_ATTR_FATTR_GROUP;
+	}
+	return true;
+}
+
+/**
+ * nfs_fattr_free_names - free up the NFSv4 owner and group strings
+ * @fattr: a fully initialised nfs_fattr structure
+ */
+void nfs_fattr_free_names(struct nfs_fattr *fattr)
+{
+	if (fattr->valid & NFS_ATTR_FATTR_OWNER_NAME)
+		nfs_fattr_free_owner_name(fattr);
+	if (fattr->valid & NFS_ATTR_FATTR_GROUP_NAME)
+		nfs_fattr_free_group_name(fattr);
+}
+
+/**
+ * nfs_fattr_map_and_free_names - map owner/group strings into uid/gid and free
+ * @server: pointer to the filesystem nfs_server structure
+ * @fattr: a fully initialised nfs_fattr structure
+ *
+ * This helper maps the cached NFSv4 owner/group strings in fattr into
+ * their numeric uid/gid equivalents, and then frees the cached strings.
+ */
+void nfs_fattr_map_and_free_names(struct nfs_server *server, struct nfs_fattr *fattr)
+{
+	if (nfs_fattr_map_owner_name(server, fattr))
+		nfs_fattr_free_owner_name(fattr);
+	if (nfs_fattr_map_group_name(server, fattr))
+		nfs_fattr_free_group_name(fattr);
+}
+
+int nfs_map_string_to_numeric(const char *name, size_t namelen, __u32 *res)
+{
+	unsigned long val;
+	char buf[16];
+
+	if (memchr(name, '@', namelen) != NULL || namelen >= sizeof(buf))
+		return 0;
+	memcpy(buf, name, namelen);
+	buf[namelen] = '\0';
+	if (kstrtoul(buf, 0, &val) != 0)
+		return 0;
+	*res = val;
+	return 1;
+}
+EXPORT_SYMBOL_GPL(nfs_map_string_to_numeric);
+
+static int nfs_map_numeric_to_string(__u32 id, char *buf, size_t buflen)
+{
+	return snprintf(buf, buflen, "%u", id);
+}
+
+static struct key_type key_type_id_resolver = {
+	.name		= "id_resolver",
+	.preparse	= user_preparse,
+	.free_preparse	= user_free_preparse,
+	.instantiate	= generic_key_instantiate,
+	.revoke		= user_revoke,
+	.destroy	= user_destroy,
+	.describe	= user_describe,
+	.read		= user_read,
+};
+
+int nfs_idmap_init(void)
+{
+	struct cred *cred;
+	struct key *keyring;
+	int ret = 0;
+
+	printk(KERN_NOTICE "NFS: Registering the %s key type\n",
+		key_type_id_resolver.name);
+
+	cred = prepare_kernel_cred(NULL);
+	if (!cred)
+		return -ENOMEM;
+
+	keyring = keyring_alloc(".id_resolver",
+				GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, cred,
+				(KEY_POS_ALL & ~KEY_POS_SETATTR) |
+				KEY_USR_VIEW | KEY_USR_READ,
+				KEY_ALLOC_NOT_IN_QUOTA, NULL, NULL);
+	if (IS_ERR(keyring)) {
+		ret = PTR_ERR(keyring);
+		goto failed_put_cred;
+	}
+
+	ret = register_key_type(&key_type_id_resolver);
+	if (ret < 0)
+		goto failed_put_key;
+
+	ret = register_key_type(&key_type_id_resolver_legacy);
+	if (ret < 0)
+		goto failed_reg_legacy;
+
+	set_bit(KEY_FLAG_ROOT_CAN_CLEAR, &keyring->flags);
+	cred->thread_keyring = keyring;
+	cred->jit_keyring = KEY_REQKEY_DEFL_THREAD_KEYRING;
+	id_resolver_cache = cred;
+	return 0;
+
+failed_reg_legacy:
+	unregister_key_type(&key_type_id_resolver);
+failed_put_key:
+	key_put(keyring);
+failed_put_cred:
+	put_cred(cred);
+	return ret;
+}
+
+void nfs_idmap_quit(void)
+{
+	key_revoke(id_resolver_cache->thread_keyring);
+	unregister_key_type(&key_type_id_resolver);
+	unregister_key_type(&key_type_id_resolver_legacy);
+	put_cred(id_resolver_cache);
+}
+
+/*
+ * Assemble the description to pass to request_key()
+ * This function will allocate a new string and update dest to point
+ * at it.  The caller is responsible for freeing dest.
+ *
+ * On error 0 is returned.  Otherwise, the length of dest is returned.
+ */
+static ssize_t nfs_idmap_get_desc(const char *name, size_t namelen,
+				const char *type, size_t typelen, char **desc)
+{
+	char *cp;
+	size_t desclen = typelen + namelen + 2;
+
+	*desc = kmalloc(desclen, GFP_KERNEL);
+	if (!*desc)
+		return -ENOMEM;
+
+	cp = *desc;
+	memcpy(cp, type, typelen);
+	cp += typelen;
+	*cp++ = ':';
+
+	memcpy(cp, name, namelen);
+	cp += namelen;
+	*cp = '\0';
+	return desclen;
+}
+
+static struct key *nfs_idmap_request_key(const char *name, size_t namelen,
+					 const char *type, struct idmap *idmap)
+{
+	char *desc;
+	struct key *rkey = ERR_PTR(-EAGAIN);
+	ssize_t ret;
+
+	ret = nfs_idmap_get_desc(name, namelen, type, strlen(type), &desc);
+	if (ret < 0)
+		return ERR_PTR(ret);
+
+	if (!idmap->user_ns || idmap->user_ns == &init_user_ns)
+		rkey = request_key(&key_type_id_resolver, desc, "");
+	if (IS_ERR(rkey)) {
+		mutex_lock(&idmap->idmap_mutex);
+		rkey = request_key_with_auxdata(&key_type_id_resolver_legacy,
+						desc, NULL, "", 0, idmap);
+		mutex_unlock(&idmap->idmap_mutex);
+	}
+	if (!IS_ERR(rkey))
+		set_bit(KEY_FLAG_ROOT_CAN_INVAL, &rkey->flags);
+
+	kfree(desc);
+	return rkey;
+}
+
+static ssize_t nfs_idmap_get_key(const char *name, size_t namelen,
+				 const char *type, void *data,
+				 size_t data_size, struct idmap *idmap)
+{
+	const struct cred *saved_cred;
+	struct key *rkey;
+	const struct user_key_payload *payload;
+	ssize_t ret;
+
+	saved_cred = override_creds(id_resolver_cache);
+	rkey = nfs_idmap_request_key(name, namelen, type, idmap);
+	revert_creds(saved_cred);
+
+	if (IS_ERR(rkey)) {
+		ret = PTR_ERR(rkey);
+		goto out;
+	}
+
+	rcu_read_lock();
+	rkey->perm |= KEY_USR_VIEW;
+
+	ret = key_validate(rkey);
+	if (ret < 0)
+		goto out_up;
+
+	payload = user_key_payload_rcu(rkey);
+	if (IS_ERR_OR_NULL(payload)) {
+		ret = PTR_ERR(payload);
+		goto out_up;
+	}
+
+	ret = payload->datalen;
+	if (ret > 0 && ret <= data_size)
+		memcpy(data, payload->data, ret);
+	else
+		ret = -EINVAL;
+
+out_up:
+	rcu_read_unlock();
+	key_put(rkey);
+out:
+	return ret;
+}
+
+/* ID -> Name */
+static ssize_t nfs_idmap_lookup_name(__u32 id, const char *type, char *buf,
+				     size_t buflen, struct idmap *idmap)
+{
+	char id_str[NFS_UINT_MAXLEN];
+	int id_len;
+	ssize_t ret;
+
+	id_len = nfs_map_numeric_to_string(id, id_str, sizeof(id_str));
+	ret = nfs_idmap_get_key(id_str, id_len, type, buf, buflen, idmap);
+	if (ret < 0)
+		return -EINVAL;
+	return ret;
+}
+
+/* Name -> ID */
+static int nfs_idmap_lookup_id(const char *name, size_t namelen, const char *type,
+			       __u32 *id, struct idmap *idmap)
+{
+	char id_str[NFS_UINT_MAXLEN];
+	long id_long;
+	ssize_t data_size;
+	int ret = 0;
+
+	data_size = nfs_idmap_get_key(name, namelen, type, id_str, NFS_UINT_MAXLEN, idmap);
+	if (data_size <= 0) {
+		ret = -EINVAL;
+	} else {
+		ret = kstrtol(id_str, 10, &id_long);
+		if (!ret)
+			*id = (__u32)id_long;
+	}
+	return ret;
+}
+
+/* idmap classic begins here */
+
+enum {
+	Opt_find_uid, Opt_find_gid, Opt_find_user, Opt_find_group, Opt_find_err
+};
+
+static const match_table_t nfs_idmap_tokens = {
+	{ Opt_find_uid, "uid:%s" },
+	{ Opt_find_gid, "gid:%s" },
+	{ Opt_find_user, "user:%s" },
+	{ Opt_find_group, "group:%s" },
+	{ Opt_find_err, NULL }
+};
+
+static int nfs_idmap_legacy_upcall(struct key *, void *);
+static ssize_t idmap_pipe_downcall(struct file *, const char __user *,
+				   size_t);
+static void idmap_release_pipe(struct inode *);
+static void idmap_pipe_destroy_msg(struct rpc_pipe_msg *);
+
+static const struct rpc_pipe_ops idmap_upcall_ops = {
+	.upcall		= rpc_pipe_generic_upcall,
+	.downcall	= idmap_pipe_downcall,
+	.release_pipe	= idmap_release_pipe,
+	.destroy_msg	= idmap_pipe_destroy_msg,
+};
+
+static struct key_type key_type_id_resolver_legacy = {
+	.name		= "id_legacy",
+	.preparse	= user_preparse,
+	.free_preparse	= user_free_preparse,
+	.instantiate	= generic_key_instantiate,
+	.revoke		= user_revoke,
+	.destroy	= user_destroy,
+	.describe	= user_describe,
+	.read		= user_read,
+	.request_key	= nfs_idmap_legacy_upcall,
+};
+
+static void nfs_idmap_pipe_destroy(struct dentry *dir,
+		struct rpc_pipe_dir_object *pdo)
+{
+	struct idmap *idmap = pdo->pdo_data;
+	struct rpc_pipe *pipe = idmap->idmap_pipe;
+
+	if (pipe->dentry) {
+		rpc_unlink(pipe->dentry);
+		pipe->dentry = NULL;
+	}
+}
+
+static int nfs_idmap_pipe_create(struct dentry *dir,
+		struct rpc_pipe_dir_object *pdo)
+{
+	struct idmap *idmap = pdo->pdo_data;
+	struct rpc_pipe *pipe = idmap->idmap_pipe;
+	struct dentry *dentry;
+
+	dentry = rpc_mkpipe_dentry(dir, "idmap", idmap, pipe);
+	if (IS_ERR(dentry))
+		return PTR_ERR(dentry);
+	pipe->dentry = dentry;
+	return 0;
+}
+
+static const struct rpc_pipe_dir_object_ops nfs_idmap_pipe_dir_object_ops = {
+	.create = nfs_idmap_pipe_create,
+	.destroy = nfs_idmap_pipe_destroy,
+};
+
+int
+nfs_idmap_new(struct nfs_client *clp)
+{
+	struct idmap *idmap;
+	struct rpc_pipe *pipe;
+	int error;
+
+	idmap = kzalloc(sizeof(*idmap), GFP_KERNEL);
+	if (idmap == NULL)
+		return -ENOMEM;
+
+	mutex_init(&idmap->idmap_mutex);
+	idmap->user_ns = get_user_ns(clp->cl_rpcclient->cl_cred->user_ns);
+
+	rpc_init_pipe_dir_object(&idmap->idmap_pdo,
+			&nfs_idmap_pipe_dir_object_ops,
+			idmap);
+
+	pipe = rpc_mkpipe_data(&idmap_upcall_ops, 0);
+	if (IS_ERR(pipe)) {
+		error = PTR_ERR(pipe);
+		goto err;
+	}
+	idmap->idmap_pipe = pipe;
+
+	error = rpc_add_pipe_dir_object(clp->cl_net,
+			&clp->cl_rpcclient->cl_pipedir_objects,
+			&idmap->idmap_pdo);
+	if (error)
+		goto err_destroy_pipe;
+
+	clp->cl_idmap = idmap;
+	return 0;
+err_destroy_pipe:
+	rpc_destroy_pipe_data(idmap->idmap_pipe);
+err:
+	put_user_ns(idmap->user_ns);
+	kfree(idmap);
+	return error;
+}
+
+void
+nfs_idmap_delete(struct nfs_client *clp)
+{
+	struct idmap *idmap = clp->cl_idmap;
+
+	if (!idmap)
+		return;
+	clp->cl_idmap = NULL;
+	rpc_remove_pipe_dir_object(clp->cl_net,
+			&clp->cl_rpcclient->cl_pipedir_objects,
+			&idmap->idmap_pdo);
+	rpc_destroy_pipe_data(idmap->idmap_pipe);
+	put_user_ns(idmap->user_ns);
+	kfree(idmap);
+}
+
+static int nfs_idmap_prepare_message(char *desc, struct idmap *idmap,
+				     struct idmap_msg *im,
+				     struct rpc_pipe_msg *msg)
+{
+	substring_t substr;
+	int token, ret;
+
+	im->im_type = IDMAP_TYPE_GROUP;
+	token = match_token(desc, nfs_idmap_tokens, &substr);
+
+	switch (token) {
+	case Opt_find_uid:
+		im->im_type = IDMAP_TYPE_USER;
+		fallthrough;
+	case Opt_find_gid:
+		im->im_conv = IDMAP_CONV_NAMETOID;
+		ret = match_strlcpy(im->im_name, &substr, IDMAP_NAMESZ);
+		break;
+
+	case Opt_find_user:
+		im->im_type = IDMAP_TYPE_USER;
+		fallthrough;
+	case Opt_find_group:
+		im->im_conv = IDMAP_CONV_IDTONAME;
+		ret = match_int(&substr, &im->im_id);
+		if (ret)
+			goto out;
+		break;
+
+	default:
+		ret = -EINVAL;
+		goto out;
+	}
+
+	msg->data = im;
+	msg->len  = sizeof(struct idmap_msg);
+
+out:
+	return ret;
+}
+
+static bool
+nfs_idmap_prepare_pipe_upcall(struct idmap *idmap,
+		struct idmap_legacy_upcalldata *data)
+{
+	if (idmap->idmap_upcall_data != NULL) {
+		WARN_ON_ONCE(1);
+		return false;
+	}
+	idmap->idmap_upcall_data = data;
+	return true;
+}
+
+static void nfs_idmap_complete_pipe_upcall(struct idmap_legacy_upcalldata *data,
+					   int ret)
+{
+	complete_request_key(data->authkey, ret);
+	key_put(data->authkey);
+	kfree(data);
+}
+
+static void nfs_idmap_abort_pipe_upcall(struct idmap *idmap,
+					struct idmap_legacy_upcalldata *data,
+					int ret)
+{
+	if (cmpxchg(&idmap->idmap_upcall_data, data, NULL) == data)
+		nfs_idmap_complete_pipe_upcall(data, ret);
+}
+
+static int nfs_idmap_legacy_upcall(struct key *authkey, void *aux)
+{
+	struct idmap_legacy_upcalldata *data;
+	struct request_key_auth *rka = get_request_key_auth(authkey);
+	struct rpc_pipe_msg *msg;
+	struct idmap_msg *im;
+	struct idmap *idmap = (struct idmap *)aux;
+	struct key *key = rka->target_key;
+	int ret = -ENOKEY;
+
+	if (!aux)
+		goto out1;
+
+	/* msg and im are freed in idmap_pipe_destroy_msg */
+	ret = -ENOMEM;
+	data = kzalloc(sizeof(*data), GFP_KERNEL);
+	if (!data)
+		goto out1;
+
+	msg = &data->pipe_msg;
+	im = &data->idmap_msg;
+	data->idmap = idmap;
+	data->authkey = key_get(authkey);
+
+	ret = nfs_idmap_prepare_message(key->description, idmap, im, msg);
+	if (ret < 0)
+		goto out2;
+
+	ret = -EAGAIN;
+	if (!nfs_idmap_prepare_pipe_upcall(idmap, data))
+		goto out2;
+
+	ret = rpc_queue_upcall(idmap->idmap_pipe, msg);
+	if (ret < 0)
+		nfs_idmap_abort_pipe_upcall(idmap, data, ret);
+
+	return ret;
+out2:
+	kfree(data);
+out1:
+	complete_request_key(authkey, ret);
+	return ret;
+}
+
+static int nfs_idmap_instantiate(struct key *key, struct key *authkey, char *data, size_t datalen)
+{
+	return key_instantiate_and_link(key, data, datalen,
+					id_resolver_cache->thread_keyring,
+					authkey);
+}
+
+static int nfs_idmap_read_and_verify_message(struct idmap_msg *im,
+		struct idmap_msg *upcall,
+		struct key *key, struct key *authkey)
+{
+	char id_str[NFS_UINT_MAXLEN];
+	size_t len;
+	int ret = -ENOKEY;
+
+	/* ret = -ENOKEY */
+	if (upcall->im_type != im->im_type || upcall->im_conv != im->im_conv)
+		goto out;
+	switch (im->im_conv) {
+	case IDMAP_CONV_NAMETOID:
+		if (strcmp(upcall->im_name, im->im_name) != 0)
+			break;
+		/* Note: here we store the NUL terminator too */
+		len = 1 + nfs_map_numeric_to_string(im->im_id, id_str,
+						    sizeof(id_str));
+		ret = nfs_idmap_instantiate(key, authkey, id_str, len);
+		break;
+	case IDMAP_CONV_IDTONAME:
+		if (upcall->im_id != im->im_id)
+			break;
+		len = strlen(im->im_name);
+		ret = nfs_idmap_instantiate(key, authkey, im->im_name, len);
+		break;
+	default:
+		ret = -EINVAL;
+	}
+out:
+	return ret;
+}
+
+static ssize_t
+idmap_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
+{
+	struct request_key_auth *rka;
+	struct rpc_inode *rpci = RPC_I(file_inode(filp));
+	struct idmap *idmap = (struct idmap *)rpci->private;
+	struct idmap_legacy_upcalldata *data;
+	struct key *authkey;
+	struct idmap_msg im;
+	size_t namelen_in;
+	int ret = -ENOKEY;
+
+	/* If instantiation is successful, anyone waiting for key construction
+	 * will have been woken up and someone else may now have used
+	 * idmap_key_cons - so after this point we may no longer touch it.
+	 */
+	data = xchg(&idmap->idmap_upcall_data, NULL);
+	if (data == NULL)
+		goto out_noupcall;
+
+	authkey = data->authkey;
+	rka = get_request_key_auth(authkey);
+
+	if (mlen != sizeof(im)) {
+		ret = -ENOSPC;
+		goto out;
+	}
+
+	if (copy_from_user(&im, src, mlen) != 0) {
+		ret = -EFAULT;
+		goto out;
+	}
+
+	if (!(im.im_status & IDMAP_STATUS_SUCCESS)) {
+		ret = -ENOKEY;
+		goto out;
+	}
+
+	namelen_in = strnlen(im.im_name, IDMAP_NAMESZ);
+	if (namelen_in == 0 || namelen_in == IDMAP_NAMESZ) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	ret = nfs_idmap_read_and_verify_message(&im, &data->idmap_msg,
+						rka->target_key, authkey);
+	if (ret >= 0) {
+		key_set_timeout(rka->target_key, nfs_idmap_cache_timeout);
+		ret = mlen;
+	}
+
+out:
+	nfs_idmap_complete_pipe_upcall(data, ret);
+out_noupcall:
+	return ret;
+}
+
+static void
+idmap_pipe_destroy_msg(struct rpc_pipe_msg *msg)
+{
+	struct idmap_legacy_upcalldata *data = container_of(msg,
+			struct idmap_legacy_upcalldata,
+			pipe_msg);
+	struct idmap *idmap = data->idmap;
+
+	if (msg->errno)
+		nfs_idmap_abort_pipe_upcall(idmap, data, msg->errno);
+}
+
+static void
+idmap_release_pipe(struct inode *inode)
+{
+	struct rpc_inode *rpci = RPC_I(inode);
+	struct idmap *idmap = (struct idmap *)rpci->private;
+	struct idmap_legacy_upcalldata *data;
+
+	data = xchg(&idmap->idmap_upcall_data, NULL);
+	if (data)
+		nfs_idmap_complete_pipe_upcall(data, -EPIPE);
+}
+
+int nfs_map_name_to_uid(const struct nfs_server *server, const char *name, size_t namelen, kuid_t *uid)
+{
+	struct idmap *idmap = server->nfs_client->cl_idmap;
+	__u32 id = -1;
+	int ret = 0;
+
+	if (!nfs_map_string_to_numeric(name, namelen, &id))
+		ret = nfs_idmap_lookup_id(name, namelen, "uid", &id, idmap);
+	if (ret == 0) {
+		*uid = make_kuid(idmap_userns(idmap), id);
+		if (!uid_valid(*uid))
+			ret = -ERANGE;
+	}
+	trace_nfs4_map_name_to_uid(name, namelen, id, ret);
+	return ret;
+}
+
+int nfs_map_group_to_gid(const struct nfs_server *server, const char *name, size_t namelen, kgid_t *gid)
+{
+	struct idmap *idmap = server->nfs_client->cl_idmap;
+	__u32 id = -1;
+	int ret = 0;
+
+	if (!nfs_map_string_to_numeric(name, namelen, &id))
+		ret = nfs_idmap_lookup_id(name, namelen, "gid", &id, idmap);
+	if (ret == 0) {
+		*gid = make_kgid(idmap_userns(idmap), id);
+		if (!gid_valid(*gid))
+			ret = -ERANGE;
+	}
+	trace_nfs4_map_group_to_gid(name, namelen, id, ret);
+	return ret;
+}
+
+int nfs_map_uid_to_name(const struct nfs_server *server, kuid_t uid, char *buf, size_t buflen)
+{
+	struct idmap *idmap = server->nfs_client->cl_idmap;
+	int ret = -EINVAL;
+	__u32 id;
+
+	id = from_kuid_munged(idmap_userns(idmap), uid);
+	if (!(server->caps & NFS_CAP_UIDGID_NOMAP))
+		ret = nfs_idmap_lookup_name(id, "user", buf, buflen, idmap);
+	if (ret < 0)
+		ret = nfs_map_numeric_to_string(id, buf, buflen);
+	trace_nfs4_map_uid_to_name(buf, ret, id, ret);
+	return ret;
+}
+int nfs_map_gid_to_group(const struct nfs_server *server, kgid_t gid, char *buf, size_t buflen)
+{
+	struct idmap *idmap = server->nfs_client->cl_idmap;
+	int ret = -EINVAL;
+	__u32 id;
+
+	id = from_kgid_munged(idmap_userns(idmap), gid);
+	if (!(server->caps & NFS_CAP_UIDGID_NOMAP))
+		ret = nfs_idmap_lookup_name(id, "group", buf, buflen, idmap);
+	if (ret < 0)
+		ret = nfs_map_numeric_to_string(id, buf, buflen);
+	trace_nfs4_map_gid_to_group(buf, ret, id, ret);
+	return ret;
+}
diff --git a/fs/nfs/nfs4idmap.h b/fs/nfs/nfs4idmap.h
new file mode 100644
index 000000000..de44d7330
--- /dev/null
+++ b/fs/nfs/nfs4idmap.h
@@ -0,0 +1,68 @@
+/*
+ * fs/nfs/nfs4idmap.h
+ *
+ *  UID and GID to name mapping for clients.
+ *
+ *  Copyright (c) 2002 The Regents of the University of Michigan.
+ *  All rights reserved.
+ *
+ *  Marius Aamodt Eriksen <marius@umich.edu>
+ *
+ *  Redistribution and use in source and binary forms, with or without
+ *  modification, are permitted provided that the following conditions
+ *  are met:
+ *
+ *  1. Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *  2. Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *  3. Neither the name of the University nor the names of its
+ *     contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+ *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+#ifndef NFS_IDMAP_H
+#define NFS_IDMAP_H
+
+#include <linux/uidgid.h>
+#include <uapi/linux/nfs_idmap.h>
+
+
+/* Forward declaration to make this header independent of others */
+struct nfs_client;
+struct nfs_server;
+struct nfs_fattr;
+struct nfs4_string;
+
+int nfs_idmap_init(void);
+void nfs_idmap_quit(void);
+int nfs_idmap_new(struct nfs_client *);
+void nfs_idmap_delete(struct nfs_client *);
+
+void nfs_fattr_init_names(struct nfs_fattr *fattr,
+		struct nfs4_string *owner_name,
+		struct nfs4_string *group_name);
+void nfs_fattr_free_names(struct nfs_fattr *);
+void nfs_fattr_map_and_free_names(struct nfs_server *, struct nfs_fattr *);
+
+int nfs_map_name_to_uid(const struct nfs_server *, const char *, size_t, kuid_t *);
+int nfs_map_group_to_gid(const struct nfs_server *, const char *, size_t, kgid_t *);
+int nfs_map_uid_to_name(const struct nfs_server *, kuid_t, char *, size_t);
+int nfs_map_gid_to_group(const struct nfs_server *, kgid_t, char *, size_t);
+
+int nfs_map_string_to_numeric(const char *name, size_t namelen, __u32 *res);
+
+extern unsigned int nfs_idmap_cache_timeout;
+#endif /* NFS_IDMAP_H */
diff --git a/fs/nfs/nfs4namespace.c b/fs/nfs/nfs4namespace.c
new file mode 100644
index 000000000..3680c8da5
--- /dev/null
+++ b/fs/nfs/nfs4namespace.c
@@ -0,0 +1,572 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/nfs/nfs4namespace.c
+ *
+ * Copyright (C) 2005 Trond Myklebust <Trond.Myklebust@netapp.com>
+ * - Modified by David Howells <dhowells@redhat.com>
+ *
+ * NFSv4 namespace
+ */
+
+#include <linux/module.h>
+#include <linux/dcache.h>
+#include <linux/mount.h>
+#include <linux/namei.h>
+#include <linux/nfs_fs.h>
+#include <linux/nfs_mount.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/sunrpc/clnt.h>
+#include <linux/sunrpc/addr.h>
+#include <linux/vfs.h>
+#include <linux/inet.h>
+#include "internal.h"
+#include "nfs4_fs.h"
+#include "nfs.h"
+#include "dns_resolve.h"
+
+#define NFSDBG_FACILITY		NFSDBG_VFS
+
+/*
+ * Work out the length that an NFSv4 path would render to as a standard posix
+ * path, with a leading slash but no terminating slash.
+ */
+static ssize_t nfs4_pathname_len(const struct nfs4_pathname *pathname)
+{
+	ssize_t len = 0;
+	int i;
+
+	for (i = 0; i < pathname->ncomponents; i++) {
+		const struct nfs4_string *component = &pathname->components[i];
+
+		if (component->len > NAME_MAX)
+			goto too_long;
+		len += 1 + component->len; /* Adding "/foo" */
+		if (len > PATH_MAX)
+			goto too_long;
+	}
+	return len;
+
+too_long:
+	return -ENAMETOOLONG;
+}
+
+/*
+ * Convert the NFSv4 pathname components into a standard posix path.
+ */
+static char *nfs4_pathname_string(const struct nfs4_pathname *pathname,
+				  unsigned short *_len)
+{
+	ssize_t len;
+	char *buf, *p;
+	int i;
+
+	len = nfs4_pathname_len(pathname);
+	if (len < 0)
+		return ERR_PTR(len);
+	*_len = len;
+
+	p = buf = kmalloc(len + 1, GFP_KERNEL);
+	if (!buf)
+		return ERR_PTR(-ENOMEM);
+
+	for (i = 0; i < pathname->ncomponents; i++) {
+		const struct nfs4_string *component = &pathname->components[i];
+
+		*p++ = '/';
+		memcpy(p, component->data, component->len);
+		p += component->len;
+	}
+
+	*p = 0;
+	return buf;
+}
+
+/*
+ * return the path component of "<server>:<path>"
+ *  nfspath - the "<server>:<path>" string
+ *  end - one past the last char that could contain "<server>:"
+ * returns NULL on failure
+ */
+static char *nfs_path_component(const char *nfspath, const char *end)
+{
+	char *p;
+
+	if (*nfspath == '[') {
+		/* parse [] escaped IPv6 addrs */
+		p = strchr(nfspath, ']');
+		if (p != NULL && ++p < end && *p == ':')
+			return p + 1;
+	} else {
+		/* otherwise split on first colon */
+		p = strchr(nfspath, ':');
+		if (p != NULL && p < end)
+			return p + 1;
+	}
+	return NULL;
+}
+
+/*
+ * Determine the mount path as a string
+ */
+static char *nfs4_path(struct dentry *dentry, char *buffer, ssize_t buflen)
+{
+	char *limit;
+	char *path = nfs_path(&limit, dentry, buffer, buflen,
+			      NFS_PATH_CANONICAL);
+	if (!IS_ERR(path)) {
+		char *path_component = nfs_path_component(path, limit);
+		if (path_component)
+			return path_component;
+	}
+	return path;
+}
+
+/*
+ * Check that fs_locations::fs_root [RFC3530 6.3] is a prefix for what we
+ * believe to be the server path to this dentry
+ */
+static int nfs4_validate_fspath(struct dentry *dentry,
+				const struct nfs4_fs_locations *locations,
+				struct nfs_fs_context *ctx)
+{
+	const char *path;
+	char *fs_path;
+	unsigned short len;
+	char *buf;
+	int n;
+
+	buf = kmalloc(4096, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	path = nfs4_path(dentry, buf, 4096);
+	if (IS_ERR(path)) {
+		kfree(buf);
+		return PTR_ERR(path);
+	}
+
+	fs_path = nfs4_pathname_string(&locations->fs_path, &len);
+	if (IS_ERR(fs_path)) {
+		kfree(buf);
+		return PTR_ERR(fs_path);
+	}
+
+	n = strncmp(path, fs_path, len);
+	kfree(buf);
+	kfree(fs_path);
+	if (n != 0) {
+		dprintk("%s: path %s does not begin with fsroot %s\n",
+			__func__, path, ctx->nfs_server.export_path);
+		return -ENOENT;
+	}
+
+	return 0;
+}
+
+size_t nfs_parse_server_name(char *string, size_t len, struct sockaddr *sa,
+			     size_t salen, struct net *net, int port)
+{
+	ssize_t ret;
+
+	ret = rpc_pton(net, string, len, sa, salen);
+	if (ret == 0) {
+		ret = rpc_uaddr2sockaddr(net, string, len, sa, salen);
+		if (ret == 0) {
+			ret = nfs_dns_resolve_name(net, string, len, sa, salen);
+			if (ret < 0)
+				ret = 0;
+		}
+	} else if (port) {
+		rpc_set_port(sa, port);
+	}
+	return ret;
+}
+
+/**
+ * nfs_find_best_sec - Find a security mechanism supported locally
+ * @clnt: pointer to rpc_clnt
+ * @server: NFS server struct
+ * @flavors: List of security tuples returned by SECINFO procedure
+ *
+ * Return an rpc client that uses the first security mechanism in
+ * "flavors" that is locally supported.  The "flavors" array
+ * is searched in the order returned from the server, per RFC 3530
+ * recommendation and each flavor is checked for membership in the
+ * sec= mount option list if it exists.
+ *
+ * Return -EPERM if no matching flavor is found in the array.
+ *
+ * Please call rpc_shutdown_client() when you are done with this rpc client.
+ *
+ */
+static struct rpc_clnt *nfs_find_best_sec(struct rpc_clnt *clnt,
+					  struct nfs_server *server,
+					  struct nfs4_secinfo_flavors *flavors)
+{
+	rpc_authflavor_t pflavor;
+	struct nfs4_secinfo4 *secinfo;
+	unsigned int i;
+
+	for (i = 0; i < flavors->num_flavors; i++) {
+		secinfo = &flavors->flavors[i];
+
+		switch (secinfo->flavor) {
+		case RPC_AUTH_NULL:
+		case RPC_AUTH_UNIX:
+		case RPC_AUTH_GSS:
+			pflavor = rpcauth_get_pseudoflavor(secinfo->flavor,
+							&secinfo->flavor_info);
+			/* does the pseudoflavor match a sec= mount opt? */
+			if (pflavor != RPC_AUTH_MAXFLAVOR &&
+			    nfs_auth_info_match(&server->auth_info, pflavor)) {
+				struct rpc_clnt *new;
+				struct rpc_cred *cred;
+
+				/* Cloning creates an rpc_auth for the flavor */
+				new = rpc_clone_client_set_auth(clnt, pflavor);
+				if (IS_ERR(new))
+					continue;
+				/**
+				* Check that the user actually can use the
+				* flavor. This is mostly for RPC_AUTH_GSS
+				* where cr_init obtains a gss context
+				*/
+				cred = rpcauth_lookupcred(new->cl_auth, 0);
+				if (IS_ERR(cred)) {
+					rpc_shutdown_client(new);
+					continue;
+				}
+				put_rpccred(cred);
+				return new;
+			}
+		}
+	}
+	return ERR_PTR(-EPERM);
+}
+
+/**
+ * nfs4_negotiate_security - in response to an NFS4ERR_WRONGSEC on lookup,
+ * return an rpc_clnt that uses the best available security flavor with
+ * respect to the secinfo flavor list and the sec= mount options.
+ *
+ * @clnt: RPC client to clone
+ * @inode: directory inode
+ * @name: lookup name
+ *
+ * Please call rpc_shutdown_client() when you are done with this rpc client.
+ */
+struct rpc_clnt *
+nfs4_negotiate_security(struct rpc_clnt *clnt, struct inode *inode,
+					const struct qstr *name)
+{
+	struct page *page;
+	struct nfs4_secinfo_flavors *flavors;
+	struct rpc_clnt *new;
+	int err;
+
+	page = alloc_page(GFP_KERNEL);
+	if (!page)
+		return ERR_PTR(-ENOMEM);
+
+	flavors = page_address(page);
+
+	err = nfs4_proc_secinfo(inode, name, flavors);
+	if (err < 0) {
+		new = ERR_PTR(err);
+		goto out;
+	}
+
+	new = nfs_find_best_sec(clnt, NFS_SERVER(inode), flavors);
+
+out:
+	put_page(page);
+	return new;
+}
+
+static int try_location(struct fs_context *fc,
+			const struct nfs4_fs_location *location)
+{
+	struct nfs_fs_context *ctx = nfs_fc2context(fc);
+	unsigned int len, s;
+	char *export_path, *source, *p;
+	int ret = -ENOENT;
+
+	/* Allocate a buffer big enough to hold any of the hostnames plus a
+	 * terminating char and also a buffer big enough to hold the hostname
+	 * plus a colon plus the path.
+	 */
+	len = 0;
+	for (s = 0; s < location->nservers; s++) {
+		const struct nfs4_string *buf = &location->servers[s];
+		if (buf->len > len)
+			len = buf->len;
+	}
+
+	kfree(ctx->nfs_server.hostname);
+	ctx->nfs_server.hostname = kmalloc(len + 1, GFP_KERNEL);
+	if (!ctx->nfs_server.hostname)
+		return -ENOMEM;
+
+	export_path = nfs4_pathname_string(&location->rootpath,
+					   &ctx->nfs_server.export_path_len);
+	if (IS_ERR(export_path))
+		return PTR_ERR(export_path);
+
+	kfree(ctx->nfs_server.export_path);
+	ctx->nfs_server.export_path = export_path;
+
+	source = kmalloc(len + 1 + ctx->nfs_server.export_path_len + 1,
+			 GFP_KERNEL);
+	if (!source)
+		return -ENOMEM;
+
+	kfree(fc->source);
+	fc->source = source;
+	for (s = 0; s < location->nservers; s++) {
+		const struct nfs4_string *buf = &location->servers[s];
+
+		if (memchr(buf->data, IPV6_SCOPE_DELIMITER, buf->len))
+			continue;
+
+		ctx->nfs_server.addrlen =
+			nfs_parse_server_name(buf->data, buf->len,
+					      &ctx->nfs_server.address,
+					      sizeof(ctx->nfs_server._address),
+					      fc->net_ns, 0);
+		if (ctx->nfs_server.addrlen == 0)
+			continue;
+
+		rpc_set_port(&ctx->nfs_server.address, NFS_PORT);
+
+		memcpy(ctx->nfs_server.hostname, buf->data, buf->len);
+		ctx->nfs_server.hostname[buf->len] = '\0';
+
+		p = source;
+		memcpy(p, buf->data, buf->len);
+		p += buf->len;
+		*p++ = ':';
+		memcpy(p, ctx->nfs_server.export_path, ctx->nfs_server.export_path_len);
+		p += ctx->nfs_server.export_path_len;
+		*p = 0;
+
+		ret = nfs4_get_referral_tree(fc);
+		if (ret == 0)
+			return 0;
+	}
+
+	return ret;
+}
+
+/**
+ * nfs_follow_referral - set up mountpoint when hitting a referral on moved error
+ * @fc: pointer to struct nfs_fs_context
+ * @locations: array of NFSv4 server location information
+ *
+ */
+static int nfs_follow_referral(struct fs_context *fc,
+			       const struct nfs4_fs_locations *locations)
+{
+	struct nfs_fs_context *ctx = nfs_fc2context(fc);
+	int loc, error;
+
+	if (locations == NULL || locations->nlocations <= 0)
+		return -ENOENT;
+
+	dprintk("%s: referral at %pd2\n", __func__, ctx->clone_data.dentry);
+
+	/* Ensure fs path is a prefix of current dentry path */
+	error = nfs4_validate_fspath(ctx->clone_data.dentry, locations, ctx);
+	if (error < 0)
+		return error;
+
+	error = -ENOENT;
+	for (loc = 0; loc < locations->nlocations; loc++) {
+		const struct nfs4_fs_location *location = &locations->locations[loc];
+
+		if (location == NULL || location->nservers <= 0 ||
+		    location->rootpath.ncomponents == 0)
+			continue;
+
+		error = try_location(fc, location);
+		if (error == 0)
+			return 0;
+	}
+
+	return error;
+}
+
+/*
+ * nfs_do_refmount - handle crossing a referral on server
+ * @dentry - dentry of referral
+ *
+ */
+static int nfs_do_refmount(struct fs_context *fc, struct rpc_clnt *client)
+{
+	struct nfs_fs_context *ctx = nfs_fc2context(fc);
+	struct dentry *dentry, *parent;
+	struct nfs4_fs_locations *fs_locations = NULL;
+	struct page *page;
+	int err = -ENOMEM;
+
+	/* BUG_ON(IS_ROOT(dentry)); */
+	page = alloc_page(GFP_KERNEL);
+	if (!page)
+		return -ENOMEM;
+
+	fs_locations = kmalloc(sizeof(struct nfs4_fs_locations), GFP_KERNEL);
+	if (!fs_locations)
+		goto out_free;
+
+	/* Get locations */
+	dentry = ctx->clone_data.dentry;
+	parent = dget_parent(dentry);
+	dprintk("%s: getting locations for %pd2\n",
+		__func__, dentry);
+
+	err = nfs4_proc_fs_locations(client, d_inode(parent), &dentry->d_name, fs_locations, page);
+	dput(parent);
+	if (err != 0)
+		goto out_free_2;
+
+	err = -ENOENT;
+	if (fs_locations->nlocations <= 0 ||
+	    fs_locations->fs_path.ncomponents <= 0)
+		goto out_free_2;
+
+	err = nfs_follow_referral(fc, fs_locations);
+out_free_2:
+	kfree(fs_locations);
+out_free:
+	__free_page(page);
+	return err;
+}
+
+int nfs4_submount(struct fs_context *fc, struct nfs_server *server)
+{
+	struct nfs_fs_context *ctx = nfs_fc2context(fc);
+	struct dentry *dentry = ctx->clone_data.dentry;
+	struct dentry *parent = dget_parent(dentry);
+	struct inode *dir = d_inode(parent);
+	struct rpc_clnt *client;
+	int ret;
+
+	/* Look it up again to get its attributes and sec flavor */
+	client = nfs4_proc_lookup_mountpoint(dir, dentry, ctx->mntfh,
+					     ctx->clone_data.fattr);
+	dput(parent);
+	if (IS_ERR(client))
+		return PTR_ERR(client);
+
+	ctx->selected_flavor = client->cl_auth->au_flavor;
+	if (ctx->clone_data.fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL) {
+		ret = nfs_do_refmount(fc, client);
+	} else {
+		ret = nfs_do_submount(fc);
+	}
+
+	rpc_shutdown_client(client);
+	return ret;
+}
+
+/*
+ * Try one location from the fs_locations array.
+ *
+ * Returns zero on success, or a negative errno value.
+ */
+static int nfs4_try_replacing_one_location(struct nfs_server *server,
+		char *page, char *page2,
+		const struct nfs4_fs_location *location)
+{
+	const size_t addr_bufsize = sizeof(struct sockaddr_storage);
+	struct net *net = rpc_net_ns(server->client);
+	struct sockaddr *sap;
+	unsigned int s;
+	size_t salen;
+	int error;
+
+	sap = kmalloc(addr_bufsize, GFP_KERNEL);
+	if (sap == NULL)
+		return -ENOMEM;
+
+	error = -ENOENT;
+	for (s = 0; s < location->nservers; s++) {
+		const struct nfs4_string *buf = &location->servers[s];
+		char *hostname;
+
+		if (buf->len <= 0 || buf->len > PAGE_SIZE)
+			continue;
+
+		if (memchr(buf->data, IPV6_SCOPE_DELIMITER, buf->len) != NULL)
+			continue;
+
+		salen = nfs_parse_server_name(buf->data, buf->len,
+						sap, addr_bufsize, net, 0);
+		if (salen == 0)
+			continue;
+		rpc_set_port(sap, NFS_PORT);
+
+		error = -ENOMEM;
+		hostname = kmemdup_nul(buf->data, buf->len, GFP_KERNEL);
+		if (hostname == NULL)
+			break;
+
+		error = nfs4_update_server(server, hostname, sap, salen, net);
+		kfree(hostname);
+		if (error == 0)
+			break;
+	}
+
+	kfree(sap);
+	return error;
+}
+
+/**
+ * nfs4_replace_transport - set up transport to destination server
+ *
+ * @server: export being migrated
+ * @locations: fs_locations array
+ *
+ * Returns zero on success, or a negative errno value.
+ *
+ * The client tries all the entries in the "locations" array, in the
+ * order returned by the server, until one works or the end of the
+ * array is reached.
+ */
+int nfs4_replace_transport(struct nfs_server *server,
+			   const struct nfs4_fs_locations *locations)
+{
+	char *page = NULL, *page2 = NULL;
+	int loc, error;
+
+	error = -ENOENT;
+	if (locations == NULL || locations->nlocations <= 0)
+		goto out;
+
+	error = -ENOMEM;
+	page = (char *) __get_free_page(GFP_USER);
+	if (!page)
+		goto out;
+	page2 = (char *) __get_free_page(GFP_USER);
+	if (!page2)
+		goto out;
+
+	for (loc = 0; loc < locations->nlocations; loc++) {
+		const struct nfs4_fs_location *location =
+						&locations->locations[loc];
+
+		if (location == NULL || location->nservers <= 0 ||
+		    location->rootpath.ncomponents == 0)
+			continue;
+
+		error = nfs4_try_replacing_one_location(server, page,
+							page2, location);
+		if (error == 0)
+			break;
+	}
+
+out:
+	free_page((unsigned long)page);
+	free_page((unsigned long)page2);
+	return error;
+}
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
new file mode 100644
index 000000000..7c3c96ed6
--- /dev/null
+++ b/fs/nfs/nfs4proc.c
@@ -0,0 +1,10530 @@
+/*
+ *  fs/nfs/nfs4proc.c
+ *
+ *  Client-side procedure declarations for NFSv4.
+ *
+ *  Copyright (c) 2002 The Regents of the University of Michigan.
+ *  All rights reserved.
+ *
+ *  Kendrick Smith <kmsmith@umich.edu>
+ *  Andy Adamson   <andros@umich.edu>
+ *
+ *  Redistribution and use in source and binary forms, with or without
+ *  modification, are permitted provided that the following conditions
+ *  are met:
+ *
+ *  1. Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *  2. Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *  3. Neither the name of the University nor the names of its
+ *     contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+ *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <linux/mm.h>
+#include <linux/delay.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/ratelimit.h>
+#include <linux/printk.h>
+#include <linux/slab.h>
+#include <linux/sunrpc/clnt.h>
+#include <linux/nfs.h>
+#include <linux/nfs4.h>
+#include <linux/nfs_fs.h>
+#include <linux/nfs_page.h>
+#include <linux/nfs_mount.h>
+#include <linux/namei.h>
+#include <linux/mount.h>
+#include <linux/module.h>
+#include <linux/xattr.h>
+#include <linux/utsname.h>
+#include <linux/freezer.h>
+#include <linux/iversion.h>
+
+#include "nfs4_fs.h"
+#include "delegation.h"
+#include "internal.h"
+#include "iostat.h"
+#include "callback.h"
+#include "pnfs.h"
+#include "netns.h"
+#include "sysfs.h"
+#include "nfs4idmap.h"
+#include "nfs4session.h"
+#include "fscache.h"
+#include "nfs42.h"
+
+#include "nfs4trace.h"
+
+#ifdef CONFIG_NFS_V4_2
+#include "nfs42.h"
+#endif /* CONFIG_NFS_V4_2 */
+
+#define NFSDBG_FACILITY		NFSDBG_PROC
+
+#define NFS4_BITMASK_SZ		3
+
+#define NFS4_POLL_RETRY_MIN	(HZ/10)
+#define NFS4_POLL_RETRY_MAX	(15*HZ)
+
+/* file attributes which can be mapped to nfs attributes */
+#define NFS4_VALID_ATTRS (ATTR_MODE \
+	| ATTR_UID \
+	| ATTR_GID \
+	| ATTR_SIZE \
+	| ATTR_ATIME \
+	| ATTR_MTIME \
+	| ATTR_CTIME \
+	| ATTR_ATIME_SET \
+	| ATTR_MTIME_SET)
+
+struct nfs4_opendata;
+static int _nfs4_recover_proc_open(struct nfs4_opendata *data);
+static int nfs4_do_fsinfo(struct nfs_server *, struct nfs_fh *, struct nfs_fsinfo *);
+static void nfs_fixup_referral_attributes(struct nfs_fattr *fattr);
+static int _nfs4_proc_getattr(struct nfs_server *server, struct nfs_fh *fhandle, struct nfs_fattr *fattr, struct nfs4_label *label, struct inode *inode);
+static int nfs4_do_setattr(struct inode *inode, const struct cred *cred,
+			    struct nfs_fattr *fattr, struct iattr *sattr,
+			    struct nfs_open_context *ctx, struct nfs4_label *ilabel,
+			    struct nfs4_label *olabel);
+#ifdef CONFIG_NFS_V4_1
+static struct rpc_task *_nfs41_proc_sequence(struct nfs_client *clp,
+		const struct cred *cred,
+		struct nfs4_slot *slot,
+		bool is_privileged);
+static int nfs41_test_stateid(struct nfs_server *, nfs4_stateid *,
+		const struct cred *);
+static int nfs41_free_stateid(struct nfs_server *, const nfs4_stateid *,
+		const struct cred *, bool);
+#endif
+static void nfs4_bitmask_set(__u32 bitmask[NFS4_BITMASK_SZ],
+			     const __u32 *src, struct inode *inode,
+			     struct nfs_server *server,
+			     struct nfs4_label *label);
+
+#ifdef CONFIG_NFS_V4_SECURITY_LABEL
+static inline struct nfs4_label *
+nfs4_label_init_security(struct inode *dir, struct dentry *dentry,
+	struct iattr *sattr, struct nfs4_label *label)
+{
+	int err;
+
+	if (label == NULL)
+		return NULL;
+
+	if (nfs_server_capable(dir, NFS_CAP_SECURITY_LABEL) == 0)
+		return NULL;
+
+	label->lfs = 0;
+	label->pi = 0;
+	label->len = 0;
+	label->label = NULL;
+
+	err = security_dentry_init_security(dentry, sattr->ia_mode,
+				&dentry->d_name, (void **)&label->label, &label->len);
+	if (err == 0)
+		return label;
+
+	return NULL;
+}
+static inline void
+nfs4_label_release_security(struct nfs4_label *label)
+{
+	if (label)
+		security_release_secctx(label->label, label->len);
+}
+static inline u32 *nfs4_bitmask(struct nfs_server *server, struct nfs4_label *label)
+{
+	if (label)
+		return server->attr_bitmask;
+
+	return server->attr_bitmask_nl;
+}
+#else
+static inline struct nfs4_label *
+nfs4_label_init_security(struct inode *dir, struct dentry *dentry,
+	struct iattr *sattr, struct nfs4_label *l)
+{ return NULL; }
+static inline void
+nfs4_label_release_security(struct nfs4_label *label)
+{ return; }
+static inline u32 *
+nfs4_bitmask(struct nfs_server *server, struct nfs4_label *label)
+{ return server->attr_bitmask; }
+#endif
+
+/* Prevent leaks of NFSv4 errors into userland */
+static int nfs4_map_errors(int err)
+{
+	if (err >= -1000)
+		return err;
+	switch (err) {
+	case -NFS4ERR_RESOURCE:
+	case -NFS4ERR_LAYOUTTRYLATER:
+	case -NFS4ERR_RECALLCONFLICT:
+	case -NFS4ERR_RETURNCONFLICT:
+		return -EREMOTEIO;
+	case -NFS4ERR_WRONGSEC:
+	case -NFS4ERR_WRONG_CRED:
+		return -EPERM;
+	case -NFS4ERR_BADOWNER:
+	case -NFS4ERR_BADNAME:
+		return -EINVAL;
+	case -NFS4ERR_SHARE_DENIED:
+		return -EACCES;
+	case -NFS4ERR_MINOR_VERS_MISMATCH:
+		return -EPROTONOSUPPORT;
+	case -NFS4ERR_FILE_OPEN:
+		return -EBUSY;
+	default:
+		dprintk("%s could not handle NFSv4 error %d\n",
+				__func__, -err);
+		break;
+	}
+	return -EIO;
+}
+
+/*
+ * This is our standard bitmap for GETATTR requests.
+ */
+const u32 nfs4_fattr_bitmap[3] = {
+	FATTR4_WORD0_TYPE
+	| FATTR4_WORD0_CHANGE
+	| FATTR4_WORD0_SIZE
+	| FATTR4_WORD0_FSID
+	| FATTR4_WORD0_FILEID,
+	FATTR4_WORD1_MODE
+	| FATTR4_WORD1_NUMLINKS
+	| FATTR4_WORD1_OWNER
+	| FATTR4_WORD1_OWNER_GROUP
+	| FATTR4_WORD1_RAWDEV
+	| FATTR4_WORD1_SPACE_USED
+	| FATTR4_WORD1_TIME_ACCESS
+	| FATTR4_WORD1_TIME_METADATA
+	| FATTR4_WORD1_TIME_MODIFY
+	| FATTR4_WORD1_MOUNTED_ON_FILEID,
+#ifdef CONFIG_NFS_V4_SECURITY_LABEL
+	FATTR4_WORD2_SECURITY_LABEL
+#endif
+};
+
+static const u32 nfs4_pnfs_open_bitmap[3] = {
+	FATTR4_WORD0_TYPE
+	| FATTR4_WORD0_CHANGE
+	| FATTR4_WORD0_SIZE
+	| FATTR4_WORD0_FSID
+	| FATTR4_WORD0_FILEID,
+	FATTR4_WORD1_MODE
+	| FATTR4_WORD1_NUMLINKS
+	| FATTR4_WORD1_OWNER
+	| FATTR4_WORD1_OWNER_GROUP
+	| FATTR4_WORD1_RAWDEV
+	| FATTR4_WORD1_SPACE_USED
+	| FATTR4_WORD1_TIME_ACCESS
+	| FATTR4_WORD1_TIME_METADATA
+	| FATTR4_WORD1_TIME_MODIFY,
+	FATTR4_WORD2_MDSTHRESHOLD
+#ifdef CONFIG_NFS_V4_SECURITY_LABEL
+	| FATTR4_WORD2_SECURITY_LABEL
+#endif
+};
+
+static const u32 nfs4_open_noattr_bitmap[3] = {
+	FATTR4_WORD0_TYPE
+	| FATTR4_WORD0_FILEID,
+};
+
+const u32 nfs4_statfs_bitmap[3] = {
+	FATTR4_WORD0_FILES_AVAIL
+	| FATTR4_WORD0_FILES_FREE
+	| FATTR4_WORD0_FILES_TOTAL,
+	FATTR4_WORD1_SPACE_AVAIL
+	| FATTR4_WORD1_SPACE_FREE
+	| FATTR4_WORD1_SPACE_TOTAL
+};
+
+const u32 nfs4_pathconf_bitmap[3] = {
+	FATTR4_WORD0_MAXLINK
+	| FATTR4_WORD0_MAXNAME,
+	0
+};
+
+const u32 nfs4_fsinfo_bitmap[3] = { FATTR4_WORD0_MAXFILESIZE
+			| FATTR4_WORD0_MAXREAD
+			| FATTR4_WORD0_MAXWRITE
+			| FATTR4_WORD0_LEASE_TIME,
+			FATTR4_WORD1_TIME_DELTA
+			| FATTR4_WORD1_FS_LAYOUT_TYPES,
+			FATTR4_WORD2_LAYOUT_BLKSIZE
+			| FATTR4_WORD2_CLONE_BLKSIZE
+			| FATTR4_WORD2_XATTR_SUPPORT
+};
+
+const u32 nfs4_fs_locations_bitmap[3] = {
+	FATTR4_WORD0_CHANGE
+	| FATTR4_WORD0_SIZE
+	| FATTR4_WORD0_FSID
+	| FATTR4_WORD0_FILEID
+	| FATTR4_WORD0_FS_LOCATIONS,
+	FATTR4_WORD1_OWNER
+	| FATTR4_WORD1_OWNER_GROUP
+	| FATTR4_WORD1_RAWDEV
+	| FATTR4_WORD1_SPACE_USED
+	| FATTR4_WORD1_TIME_ACCESS
+	| FATTR4_WORD1_TIME_METADATA
+	| FATTR4_WORD1_TIME_MODIFY
+	| FATTR4_WORD1_MOUNTED_ON_FILEID,
+};
+
+static void nfs4_bitmap_copy_adjust(__u32 *dst, const __u32 *src,
+		struct inode *inode)
+{
+	unsigned long cache_validity;
+
+	memcpy(dst, src, NFS4_BITMASK_SZ*sizeof(*dst));
+	if (!inode || !nfs4_have_delegation(inode, FMODE_READ))
+		return;
+
+	cache_validity = READ_ONCE(NFS_I(inode)->cache_validity);
+	if (!(cache_validity & NFS_INO_REVAL_FORCED))
+		cache_validity &= ~(NFS_INO_INVALID_CHANGE
+				| NFS_INO_INVALID_SIZE);
+
+	if (!(cache_validity & NFS_INO_INVALID_SIZE))
+		dst[0] &= ~FATTR4_WORD0_SIZE;
+
+	if (!(cache_validity & NFS_INO_INVALID_CHANGE))
+		dst[0] &= ~FATTR4_WORD0_CHANGE;
+}
+
+static void nfs4_bitmap_copy_adjust_setattr(__u32 *dst,
+		const __u32 *src, struct inode *inode)
+{
+	nfs4_bitmap_copy_adjust(dst, src, inode);
+}
+
+static void nfs4_setup_readdir(u64 cookie, __be32 *verifier, struct dentry *dentry,
+		struct nfs4_readdir_arg *readdir)
+{
+	unsigned int attrs = FATTR4_WORD0_FILEID | FATTR4_WORD0_TYPE;
+	__be32 *start, *p;
+
+	if (cookie > 2) {
+		readdir->cookie = cookie;
+		memcpy(&readdir->verifier, verifier, sizeof(readdir->verifier));
+		return;
+	}
+
+	readdir->cookie = 0;
+	memset(&readdir->verifier, 0, sizeof(readdir->verifier));
+	if (cookie == 2)
+		return;
+	
+	/*
+	 * NFSv4 servers do not return entries for '.' and '..'
+	 * Therefore, we fake these entries here.  We let '.'
+	 * have cookie 0 and '..' have cookie 1.  Note that
+	 * when talking to the server, we always send cookie 0
+	 * instead of 1 or 2.
+	 */
+	start = p = kmap_atomic(*readdir->pages);
+	
+	if (cookie == 0) {
+		*p++ = xdr_one;                                  /* next */
+		*p++ = xdr_zero;                   /* cookie, first word */
+		*p++ = xdr_one;                   /* cookie, second word */
+		*p++ = xdr_one;                             /* entry len */
+		memcpy(p, ".\0\0\0", 4);                        /* entry */
+		p++;
+		*p++ = xdr_one;                         /* bitmap length */
+		*p++ = htonl(attrs);                           /* bitmap */
+		*p++ = htonl(12);             /* attribute buffer length */
+		*p++ = htonl(NF4DIR);
+		p = xdr_encode_hyper(p, NFS_FILEID(d_inode(dentry)));
+	}
+	
+	*p++ = xdr_one;                                  /* next */
+	*p++ = xdr_zero;                   /* cookie, first word */
+	*p++ = xdr_two;                   /* cookie, second word */
+	*p++ = xdr_two;                             /* entry len */
+	memcpy(p, "..\0\0", 4);                         /* entry */
+	p++;
+	*p++ = xdr_one;                         /* bitmap length */
+	*p++ = htonl(attrs);                           /* bitmap */
+	*p++ = htonl(12);             /* attribute buffer length */
+	*p++ = htonl(NF4DIR);
+	p = xdr_encode_hyper(p, NFS_FILEID(d_inode(dentry->d_parent)));
+
+	readdir->pgbase = (char *)p - (char *)start;
+	readdir->count -= readdir->pgbase;
+	kunmap_atomic(start);
+}
+
+static void nfs4_fattr_set_prechange(struct nfs_fattr *fattr, u64 version)
+{
+	if (!(fattr->valid & NFS_ATTR_FATTR_PRECHANGE)) {
+		fattr->pre_change_attr = version;
+		fattr->valid |= NFS_ATTR_FATTR_PRECHANGE;
+	}
+}
+
+static void nfs4_test_and_free_stateid(struct nfs_server *server,
+		nfs4_stateid *stateid,
+		const struct cred *cred)
+{
+	const struct nfs4_minor_version_ops *ops = server->nfs_client->cl_mvops;
+
+	ops->test_and_free_expired(server, stateid, cred);
+}
+
+static void __nfs4_free_revoked_stateid(struct nfs_server *server,
+		nfs4_stateid *stateid,
+		const struct cred *cred)
+{
+	stateid->type = NFS4_REVOKED_STATEID_TYPE;
+	nfs4_test_and_free_stateid(server, stateid, cred);
+}
+
+static void nfs4_free_revoked_stateid(struct nfs_server *server,
+		const nfs4_stateid *stateid,
+		const struct cred *cred)
+{
+	nfs4_stateid tmp;
+
+	nfs4_stateid_copy(&tmp, stateid);
+	__nfs4_free_revoked_stateid(server, &tmp, cred);
+}
+
+static long nfs4_update_delay(long *timeout)
+{
+	long ret;
+	if (!timeout)
+		return NFS4_POLL_RETRY_MAX;
+	if (*timeout <= 0)
+		*timeout = NFS4_POLL_RETRY_MIN;
+	if (*timeout > NFS4_POLL_RETRY_MAX)
+		*timeout = NFS4_POLL_RETRY_MAX;
+	ret = *timeout;
+	*timeout <<= 1;
+	return ret;
+}
+
+static int nfs4_delay_killable(long *timeout)
+{
+	might_sleep();
+
+	freezable_schedule_timeout_killable_unsafe(
+		nfs4_update_delay(timeout));
+	if (!__fatal_signal_pending(current))
+		return 0;
+	return -EINTR;
+}
+
+static int nfs4_delay_interruptible(long *timeout)
+{
+	might_sleep();
+
+	freezable_schedule_timeout_interruptible_unsafe(nfs4_update_delay(timeout));
+	if (!signal_pending(current))
+		return 0;
+	return __fatal_signal_pending(current) ? -EINTR :-ERESTARTSYS;
+}
+
+static int nfs4_delay(long *timeout, bool interruptible)
+{
+	if (interruptible)
+		return nfs4_delay_interruptible(timeout);
+	return nfs4_delay_killable(timeout);
+}
+
+static const nfs4_stateid *
+nfs4_recoverable_stateid(const nfs4_stateid *stateid)
+{
+	if (!stateid)
+		return NULL;
+	switch (stateid->type) {
+	case NFS4_OPEN_STATEID_TYPE:
+	case NFS4_LOCK_STATEID_TYPE:
+	case NFS4_DELEGATION_STATEID_TYPE:
+		return stateid;
+	default:
+		break;
+	}
+	return NULL;
+}
+
+/* This is the error handling routine for processes that are allowed
+ * to sleep.
+ */
+static int nfs4_do_handle_exception(struct nfs_server *server,
+		int errorcode, struct nfs4_exception *exception)
+{
+	struct nfs_client *clp = server->nfs_client;
+	struct nfs4_state *state = exception->state;
+	const nfs4_stateid *stateid;
+	struct inode *inode = exception->inode;
+	int ret = errorcode;
+
+	exception->delay = 0;
+	exception->recovering = 0;
+	exception->retry = 0;
+
+	stateid = nfs4_recoverable_stateid(exception->stateid);
+	if (stateid == NULL && state != NULL)
+		stateid = nfs4_recoverable_stateid(&state->stateid);
+
+	switch(errorcode) {
+		case 0:
+			return 0;
+		case -NFS4ERR_BADHANDLE:
+		case -ESTALE:
+			if (inode != NULL && S_ISREG(inode->i_mode))
+				pnfs_destroy_layout(NFS_I(inode));
+			break;
+		case -NFS4ERR_DELEG_REVOKED:
+		case -NFS4ERR_ADMIN_REVOKED:
+		case -NFS4ERR_EXPIRED:
+		case -NFS4ERR_BAD_STATEID:
+		case -NFS4ERR_PARTNER_NO_AUTH:
+			if (inode != NULL && stateid != NULL) {
+				nfs_inode_find_state_and_recover(inode,
+						stateid);
+				goto wait_on_recovery;
+			}
+			fallthrough;
+		case -NFS4ERR_OPENMODE:
+			if (inode) {
+				int err;
+
+				err = nfs_async_inode_return_delegation(inode,
+						stateid);
+				if (err == 0)
+					goto wait_on_recovery;
+				if (stateid != NULL && stateid->type == NFS4_DELEGATION_STATEID_TYPE) {
+					exception->retry = 1;
+					break;
+				}
+			}
+			if (state == NULL)
+				break;
+			ret = nfs4_schedule_stateid_recovery(server, state);
+			if (ret < 0)
+				break;
+			goto wait_on_recovery;
+		case -NFS4ERR_STALE_STATEID:
+		case -NFS4ERR_STALE_CLIENTID:
+			nfs4_schedule_lease_recovery(clp);
+			goto wait_on_recovery;
+		case -NFS4ERR_MOVED:
+			ret = nfs4_schedule_migration_recovery(server);
+			if (ret < 0)
+				break;
+			goto wait_on_recovery;
+		case -NFS4ERR_LEASE_MOVED:
+			nfs4_schedule_lease_moved_recovery(clp);
+			goto wait_on_recovery;
+#if defined(CONFIG_NFS_V4_1)
+		case -NFS4ERR_BADSESSION:
+		case -NFS4ERR_BADSLOT:
+		case -NFS4ERR_BAD_HIGH_SLOT:
+		case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
+		case -NFS4ERR_DEADSESSION:
+		case -NFS4ERR_SEQ_FALSE_RETRY:
+		case -NFS4ERR_SEQ_MISORDERED:
+			/* Handled in nfs41_sequence_process() */
+			goto wait_on_recovery;
+#endif /* defined(CONFIG_NFS_V4_1) */
+		case -NFS4ERR_FILE_OPEN:
+			if (exception->timeout > HZ) {
+				/* We have retried a decent amount, time to
+				 * fail
+				 */
+				ret = -EBUSY;
+				break;
+			}
+			fallthrough;
+		case -NFS4ERR_DELAY:
+			nfs_inc_server_stats(server, NFSIOS_DELAY);
+			fallthrough;
+		case -NFS4ERR_GRACE:
+		case -NFS4ERR_LAYOUTTRYLATER:
+		case -NFS4ERR_RECALLCONFLICT:
+		case -NFS4ERR_RETURNCONFLICT:
+			exception->delay = 1;
+			return 0;
+
+		case -NFS4ERR_RETRY_UNCACHED_REP:
+		case -NFS4ERR_OLD_STATEID:
+			exception->retry = 1;
+			break;
+		case -NFS4ERR_BADOWNER:
+			/* The following works around a Linux server bug! */
+		case -NFS4ERR_BADNAME:
+			if (server->caps & NFS_CAP_UIDGID_NOMAP) {
+				server->caps &= ~NFS_CAP_UIDGID_NOMAP;
+				exception->retry = 1;
+				printk(KERN_WARNING "NFS: v4 server %s "
+						"does not accept raw "
+						"uid/gids. "
+						"Reenabling the idmapper.\n",
+						server->nfs_client->cl_hostname);
+			}
+	}
+	/* We failed to handle the error */
+	return nfs4_map_errors(ret);
+wait_on_recovery:
+	exception->recovering = 1;
+	return 0;
+}
+
+/* This is the error handling routine for processes that are allowed
+ * to sleep.
+ */
+int nfs4_handle_exception(struct nfs_server *server, int errorcode, struct nfs4_exception *exception)
+{
+	struct nfs_client *clp = server->nfs_client;
+	int ret;
+
+	ret = nfs4_do_handle_exception(server, errorcode, exception);
+	if (exception->delay) {
+		ret = nfs4_delay(&exception->timeout,
+				exception->interruptible);
+		goto out_retry;
+	}
+	if (exception->recovering) {
+		if (exception->task_is_privileged)
+			return -EDEADLOCK;
+		ret = nfs4_wait_clnt_recover(clp);
+		if (test_bit(NFS_MIG_FAILED, &server->mig_status))
+			return -EIO;
+		goto out_retry;
+	}
+	return ret;
+out_retry:
+	if (ret == 0)
+		exception->retry = 1;
+	return ret;
+}
+
+static int
+nfs4_async_handle_exception(struct rpc_task *task, struct nfs_server *server,
+		int errorcode, struct nfs4_exception *exception)
+{
+	struct nfs_client *clp = server->nfs_client;
+	int ret;
+
+	ret = nfs4_do_handle_exception(server, errorcode, exception);
+	if (exception->delay) {
+		rpc_delay(task, nfs4_update_delay(&exception->timeout));
+		goto out_retry;
+	}
+	if (exception->recovering) {
+		if (exception->task_is_privileged)
+			return -EDEADLOCK;
+		rpc_sleep_on(&clp->cl_rpcwaitq, task, NULL);
+		if (test_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state) == 0)
+			rpc_wake_up_queued_task(&clp->cl_rpcwaitq, task);
+		goto out_retry;
+	}
+	if (test_bit(NFS_MIG_FAILED, &server->mig_status))
+		ret = -EIO;
+	return ret;
+out_retry:
+	if (ret == 0) {
+		exception->retry = 1;
+		/*
+		 * For NFS4ERR_MOVED, the client transport will need to
+		 * be recomputed after migration recovery has completed.
+		 */
+		if (errorcode == -NFS4ERR_MOVED)
+			rpc_task_release_transport(task);
+	}
+	return ret;
+}
+
+int
+nfs4_async_handle_error(struct rpc_task *task, struct nfs_server *server,
+			struct nfs4_state *state, long *timeout)
+{
+	struct nfs4_exception exception = {
+		.state = state,
+	};
+
+	if (task->tk_status >= 0)
+		return 0;
+	if (timeout)
+		exception.timeout = *timeout;
+	task->tk_status = nfs4_async_handle_exception(task, server,
+			task->tk_status,
+			&exception);
+	if (exception.delay && timeout)
+		*timeout = exception.timeout;
+	if (exception.retry)
+		return -EAGAIN;
+	return 0;
+}
+
+/*
+ * Return 'true' if 'clp' is using an rpc_client that is integrity protected
+ * or 'false' otherwise.
+ */
+static bool _nfs4_is_integrity_protected(struct nfs_client *clp)
+{
+	rpc_authflavor_t flavor = clp->cl_rpcclient->cl_auth->au_flavor;
+	return (flavor == RPC_AUTH_GSS_KRB5I) || (flavor == RPC_AUTH_GSS_KRB5P);
+}
+
+static void do_renew_lease(struct nfs_client *clp, unsigned long timestamp)
+{
+	spin_lock(&clp->cl_lock);
+	if (time_before(clp->cl_last_renewal,timestamp))
+		clp->cl_last_renewal = timestamp;
+	spin_unlock(&clp->cl_lock);
+}
+
+static void renew_lease(const struct nfs_server *server, unsigned long timestamp)
+{
+	struct nfs_client *clp = server->nfs_client;
+
+	if (!nfs4_has_session(clp))
+		do_renew_lease(clp, timestamp);
+}
+
+struct nfs4_call_sync_data {
+	const struct nfs_server *seq_server;
+	struct nfs4_sequence_args *seq_args;
+	struct nfs4_sequence_res *seq_res;
+};
+
+void nfs4_init_sequence(struct nfs4_sequence_args *args,
+			struct nfs4_sequence_res *res, int cache_reply,
+			int privileged)
+{
+	args->sa_slot = NULL;
+	args->sa_cache_this = cache_reply;
+	args->sa_privileged = privileged;
+
+	res->sr_slot = NULL;
+}
+
+static void nfs40_sequence_free_slot(struct nfs4_sequence_res *res)
+{
+	struct nfs4_slot *slot = res->sr_slot;
+	struct nfs4_slot_table *tbl;
+
+	tbl = slot->table;
+	spin_lock(&tbl->slot_tbl_lock);
+	if (!nfs41_wake_and_assign_slot(tbl, slot))
+		nfs4_free_slot(tbl, slot);
+	spin_unlock(&tbl->slot_tbl_lock);
+
+	res->sr_slot = NULL;
+}
+
+static int nfs40_sequence_done(struct rpc_task *task,
+			       struct nfs4_sequence_res *res)
+{
+	if (res->sr_slot != NULL)
+		nfs40_sequence_free_slot(res);
+	return 1;
+}
+
+#if defined(CONFIG_NFS_V4_1)
+
+static void nfs41_release_slot(struct nfs4_slot *slot)
+{
+	struct nfs4_session *session;
+	struct nfs4_slot_table *tbl;
+	bool send_new_highest_used_slotid = false;
+
+	if (!slot)
+		return;
+	tbl = slot->table;
+	session = tbl->session;
+
+	/* Bump the slot sequence number */
+	if (slot->seq_done)
+		slot->seq_nr++;
+	slot->seq_done = 0;
+
+	spin_lock(&tbl->slot_tbl_lock);
+	/* Be nice to the server: try to ensure that the last transmitted
+	 * value for highest_user_slotid <= target_highest_slotid
+	 */
+	if (tbl->highest_used_slotid > tbl->target_highest_slotid)
+		send_new_highest_used_slotid = true;
+
+	if (nfs41_wake_and_assign_slot(tbl, slot)) {
+		send_new_highest_used_slotid = false;
+		goto out_unlock;
+	}
+	nfs4_free_slot(tbl, slot);
+
+	if (tbl->highest_used_slotid != NFS4_NO_SLOT)
+		send_new_highest_used_slotid = false;
+out_unlock:
+	spin_unlock(&tbl->slot_tbl_lock);
+	if (send_new_highest_used_slotid)
+		nfs41_notify_server(session->clp);
+	if (waitqueue_active(&tbl->slot_waitq))
+		wake_up_all(&tbl->slot_waitq);
+}
+
+static void nfs41_sequence_free_slot(struct nfs4_sequence_res *res)
+{
+	nfs41_release_slot(res->sr_slot);
+	res->sr_slot = NULL;
+}
+
+static void nfs4_slot_sequence_record_sent(struct nfs4_slot *slot,
+		u32 seqnr)
+{
+	if ((s32)(seqnr - slot->seq_nr_highest_sent) > 0)
+		slot->seq_nr_highest_sent = seqnr;
+}
+static void nfs4_slot_sequence_acked(struct nfs4_slot *slot, u32 seqnr)
+{
+	nfs4_slot_sequence_record_sent(slot, seqnr);
+	slot->seq_nr_last_acked = seqnr;
+}
+
+static void nfs4_probe_sequence(struct nfs_client *client, const struct cred *cred,
+				struct nfs4_slot *slot)
+{
+	struct rpc_task *task = _nfs41_proc_sequence(client, cred, slot, true);
+	if (!IS_ERR(task))
+		rpc_put_task_async(task);
+}
+
+static int nfs41_sequence_process(struct rpc_task *task,
+		struct nfs4_sequence_res *res)
+{
+	struct nfs4_session *session;
+	struct nfs4_slot *slot = res->sr_slot;
+	struct nfs_client *clp;
+	int status;
+	int ret = 1;
+
+	if (slot == NULL)
+		goto out_noaction;
+	/* don't increment the sequence number if the task wasn't sent */
+	if (!RPC_WAS_SENT(task) || slot->seq_done)
+		goto out;
+
+	session = slot->table->session;
+	clp = session->clp;
+
+	trace_nfs4_sequence_done(session, res);
+
+	status = res->sr_status;
+	if (task->tk_status == -NFS4ERR_DEADSESSION)
+		status = -NFS4ERR_DEADSESSION;
+
+	/* Check the SEQUENCE operation status */
+	switch (status) {
+	case 0:
+		/* Mark this sequence number as having been acked */
+		nfs4_slot_sequence_acked(slot, slot->seq_nr);
+		/* Update the slot's sequence and clientid lease timer */
+		slot->seq_done = 1;
+		do_renew_lease(clp, res->sr_timestamp);
+		/* Check sequence flags */
+		nfs41_handle_sequence_flag_errors(clp, res->sr_status_flags,
+				!!slot->privileged);
+		nfs41_update_target_slotid(slot->table, slot, res);
+		break;
+	case 1:
+		/*
+		 * sr_status remains 1 if an RPC level error occurred.
+		 * The server may or may not have processed the sequence
+		 * operation..
+		 */
+		nfs4_slot_sequence_record_sent(slot, slot->seq_nr);
+		slot->seq_done = 1;
+		goto out;
+	case -NFS4ERR_DELAY:
+		/* The server detected a resend of the RPC call and
+		 * returned NFS4ERR_DELAY as per Section 2.10.6.2
+		 * of RFC5661.
+		 */
+		dprintk("%s: slot=%u seq=%u: Operation in progress\n",
+			__func__,
+			slot->slot_nr,
+			slot->seq_nr);
+		goto out_retry;
+	case -NFS4ERR_RETRY_UNCACHED_REP:
+	case -NFS4ERR_SEQ_FALSE_RETRY:
+		/*
+		 * The server thinks we tried to replay a request.
+		 * Retry the call after bumping the sequence ID.
+		 */
+		nfs4_slot_sequence_acked(slot, slot->seq_nr);
+		goto retry_new_seq;
+	case -NFS4ERR_BADSLOT:
+		/*
+		 * The slot id we used was probably retired. Try again
+		 * using a different slot id.
+		 */
+		if (slot->slot_nr < slot->table->target_highest_slotid)
+			goto session_recover;
+		goto retry_nowait;
+	case -NFS4ERR_SEQ_MISORDERED:
+		nfs4_slot_sequence_record_sent(slot, slot->seq_nr);
+		/*
+		 * Were one or more calls using this slot interrupted?
+		 * If the server never received the request, then our
+		 * transmitted slot sequence number may be too high. However,
+		 * if the server did receive the request then it might
+		 * accidentally give us a reply with a mismatched operation.
+		 * We can sort this out by sending a lone sequence operation
+		 * to the server on the same slot.
+		 */
+		if ((s32)(slot->seq_nr - slot->seq_nr_last_acked) > 1) {
+			slot->seq_nr--;
+			if (task->tk_msg.rpc_proc != &nfs4_procedures[NFSPROC4_CLNT_SEQUENCE]) {
+				nfs4_probe_sequence(clp, task->tk_msg.rpc_cred, slot);
+				res->sr_slot = NULL;
+			}
+			goto retry_nowait;
+		}
+		/*
+		 * RFC5661:
+		 * A retry might be sent while the original request is
+		 * still in progress on the replier. The replier SHOULD
+		 * deal with the issue by returning NFS4ERR_DELAY as the
+		 * reply to SEQUENCE or CB_SEQUENCE operation, but
+		 * implementations MAY return NFS4ERR_SEQ_MISORDERED.
+		 *
+		 * Restart the search after a delay.
+		 */
+		slot->seq_nr = slot->seq_nr_highest_sent;
+		goto out_retry;
+	case -NFS4ERR_BADSESSION:
+	case -NFS4ERR_DEADSESSION:
+	case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
+		goto session_recover;
+	default:
+		/* Just update the slot sequence no. */
+		slot->seq_done = 1;
+	}
+out:
+	/* The session may be reset by one of the error handlers. */
+	dprintk("%s: Error %d free the slot \n", __func__, res->sr_status);
+out_noaction:
+	return ret;
+session_recover:
+	set_bit(NFS4_SLOT_TBL_DRAINING, &session->fc_slot_table.slot_tbl_state);
+	nfs4_schedule_session_recovery(session, status);
+	dprintk("%s ERROR: %d Reset session\n", __func__, status);
+	nfs41_sequence_free_slot(res);
+	goto out;
+retry_new_seq:
+	++slot->seq_nr;
+retry_nowait:
+	if (rpc_restart_call_prepare(task)) {
+		nfs41_sequence_free_slot(res);
+		task->tk_status = 0;
+		ret = 0;
+	}
+	goto out;
+out_retry:
+	if (!rpc_restart_call(task))
+		goto out;
+	rpc_delay(task, NFS4_POLL_RETRY_MAX);
+	return 0;
+}
+
+int nfs41_sequence_done(struct rpc_task *task, struct nfs4_sequence_res *res)
+{
+	if (!nfs41_sequence_process(task, res))
+		return 0;
+	if (res->sr_slot != NULL)
+		nfs41_sequence_free_slot(res);
+	return 1;
+
+}
+EXPORT_SYMBOL_GPL(nfs41_sequence_done);
+
+static int nfs4_sequence_process(struct rpc_task *task, struct nfs4_sequence_res *res)
+{
+	if (res->sr_slot == NULL)
+		return 1;
+	if (res->sr_slot->table->session != NULL)
+		return nfs41_sequence_process(task, res);
+	return nfs40_sequence_done(task, res);
+}
+
+static void nfs4_sequence_free_slot(struct nfs4_sequence_res *res)
+{
+	if (res->sr_slot != NULL) {
+		if (res->sr_slot->table->session != NULL)
+			nfs41_sequence_free_slot(res);
+		else
+			nfs40_sequence_free_slot(res);
+	}
+}
+
+int nfs4_sequence_done(struct rpc_task *task, struct nfs4_sequence_res *res)
+{
+	if (res->sr_slot == NULL)
+		return 1;
+	if (!res->sr_slot->table->session)
+		return nfs40_sequence_done(task, res);
+	return nfs41_sequence_done(task, res);
+}
+EXPORT_SYMBOL_GPL(nfs4_sequence_done);
+
+static void nfs41_call_sync_prepare(struct rpc_task *task, void *calldata)
+{
+	struct nfs4_call_sync_data *data = calldata;
+
+	dprintk("--> %s data->seq_server %p\n", __func__, data->seq_server);
+
+	nfs4_setup_sequence(data->seq_server->nfs_client,
+			    data->seq_args, data->seq_res, task);
+}
+
+static void nfs41_call_sync_done(struct rpc_task *task, void *calldata)
+{
+	struct nfs4_call_sync_data *data = calldata;
+
+	nfs41_sequence_done(task, data->seq_res);
+}
+
+static const struct rpc_call_ops nfs41_call_sync_ops = {
+	.rpc_call_prepare = nfs41_call_sync_prepare,
+	.rpc_call_done = nfs41_call_sync_done,
+};
+
+#else	/* !CONFIG_NFS_V4_1 */
+
+static int nfs4_sequence_process(struct rpc_task *task, struct nfs4_sequence_res *res)
+{
+	return nfs40_sequence_done(task, res);
+}
+
+static void nfs4_sequence_free_slot(struct nfs4_sequence_res *res)
+{
+	if (res->sr_slot != NULL)
+		nfs40_sequence_free_slot(res);
+}
+
+int nfs4_sequence_done(struct rpc_task *task,
+		       struct nfs4_sequence_res *res)
+{
+	return nfs40_sequence_done(task, res);
+}
+EXPORT_SYMBOL_GPL(nfs4_sequence_done);
+
+#endif	/* !CONFIG_NFS_V4_1 */
+
+static void nfs41_sequence_res_init(struct nfs4_sequence_res *res)
+{
+	res->sr_timestamp = jiffies;
+	res->sr_status_flags = 0;
+	res->sr_status = 1;
+}
+
+static
+void nfs4_sequence_attach_slot(struct nfs4_sequence_args *args,
+		struct nfs4_sequence_res *res,
+		struct nfs4_slot *slot)
+{
+	if (!slot)
+		return;
+	slot->privileged = args->sa_privileged ? 1 : 0;
+	args->sa_slot = slot;
+
+	res->sr_slot = slot;
+}
+
+int nfs4_setup_sequence(struct nfs_client *client,
+			struct nfs4_sequence_args *args,
+			struct nfs4_sequence_res *res,
+			struct rpc_task *task)
+{
+	struct nfs4_session *session = nfs4_get_session(client);
+	struct nfs4_slot_table *tbl  = client->cl_slot_tbl;
+	struct nfs4_slot *slot;
+
+	/* slot already allocated? */
+	if (res->sr_slot != NULL)
+		goto out_start;
+
+	if (session)
+		tbl = &session->fc_slot_table;
+
+	spin_lock(&tbl->slot_tbl_lock);
+	/* The state manager will wait until the slot table is empty */
+	if (nfs4_slot_tbl_draining(tbl) && !args->sa_privileged)
+		goto out_sleep;
+
+	slot = nfs4_alloc_slot(tbl);
+	if (IS_ERR(slot)) {
+		if (slot == ERR_PTR(-ENOMEM))
+			goto out_sleep_timeout;
+		goto out_sleep;
+	}
+	spin_unlock(&tbl->slot_tbl_lock);
+
+	nfs4_sequence_attach_slot(args, res, slot);
+
+	trace_nfs4_setup_sequence(session, args);
+out_start:
+	nfs41_sequence_res_init(res);
+	rpc_call_start(task);
+	return 0;
+out_sleep_timeout:
+	/* Try again in 1/4 second */
+	if (args->sa_privileged)
+		rpc_sleep_on_priority_timeout(&tbl->slot_tbl_waitq, task,
+				jiffies + (HZ >> 2), RPC_PRIORITY_PRIVILEGED);
+	else
+		rpc_sleep_on_timeout(&tbl->slot_tbl_waitq, task,
+				NULL, jiffies + (HZ >> 2));
+	spin_unlock(&tbl->slot_tbl_lock);
+	return -EAGAIN;
+out_sleep:
+	if (args->sa_privileged)
+		rpc_sleep_on_priority(&tbl->slot_tbl_waitq, task,
+				RPC_PRIORITY_PRIVILEGED);
+	else
+		rpc_sleep_on(&tbl->slot_tbl_waitq, task, NULL);
+	spin_unlock(&tbl->slot_tbl_lock);
+	return -EAGAIN;
+}
+EXPORT_SYMBOL_GPL(nfs4_setup_sequence);
+
+static void nfs40_call_sync_prepare(struct rpc_task *task, void *calldata)
+{
+	struct nfs4_call_sync_data *data = calldata;
+	nfs4_setup_sequence(data->seq_server->nfs_client,
+				data->seq_args, data->seq_res, task);
+}
+
+static void nfs40_call_sync_done(struct rpc_task *task, void *calldata)
+{
+	struct nfs4_call_sync_data *data = calldata;
+	nfs4_sequence_done(task, data->seq_res);
+}
+
+static const struct rpc_call_ops nfs40_call_sync_ops = {
+	.rpc_call_prepare = nfs40_call_sync_prepare,
+	.rpc_call_done = nfs40_call_sync_done,
+};
+
+static int nfs4_call_sync_custom(struct rpc_task_setup *task_setup)
+{
+	int ret;
+	struct rpc_task *task;
+
+	task = rpc_run_task(task_setup);
+	if (IS_ERR(task))
+		return PTR_ERR(task);
+
+	ret = task->tk_status;
+	rpc_put_task(task);
+	return ret;
+}
+
+static int nfs4_do_call_sync(struct rpc_clnt *clnt,
+			     struct nfs_server *server,
+			     struct rpc_message *msg,
+			     struct nfs4_sequence_args *args,
+			     struct nfs4_sequence_res *res,
+			     unsigned short task_flags)
+{
+	struct nfs_client *clp = server->nfs_client;
+	struct nfs4_call_sync_data data = {
+		.seq_server = server,
+		.seq_args = args,
+		.seq_res = res,
+	};
+	struct rpc_task_setup task_setup = {
+		.rpc_client = clnt,
+		.rpc_message = msg,
+		.callback_ops = clp->cl_mvops->call_sync_ops,
+		.callback_data = &data,
+		.flags = task_flags,
+	};
+
+	return nfs4_call_sync_custom(&task_setup);
+}
+
+static int nfs4_call_sync_sequence(struct rpc_clnt *clnt,
+				   struct nfs_server *server,
+				   struct rpc_message *msg,
+				   struct nfs4_sequence_args *args,
+				   struct nfs4_sequence_res *res)
+{
+	return nfs4_do_call_sync(clnt, server, msg, args, res, 0);
+}
+
+
+int nfs4_call_sync(struct rpc_clnt *clnt,
+		   struct nfs_server *server,
+		   struct rpc_message *msg,
+		   struct nfs4_sequence_args *args,
+		   struct nfs4_sequence_res *res,
+		   int cache_reply)
+{
+	nfs4_init_sequence(args, res, cache_reply, 0);
+	return nfs4_call_sync_sequence(clnt, server, msg, args, res);
+}
+
+static void
+nfs4_inc_nlink_locked(struct inode *inode)
+{
+	NFS_I(inode)->cache_validity |= NFS_INO_INVALID_OTHER;
+	inc_nlink(inode);
+}
+
+static void
+nfs4_dec_nlink_locked(struct inode *inode)
+{
+	NFS_I(inode)->cache_validity |= NFS_INO_INVALID_OTHER;
+	drop_nlink(inode);
+}
+
+static void
+nfs4_update_changeattr_locked(struct inode *inode,
+		struct nfs4_change_info *cinfo,
+		unsigned long timestamp, unsigned long cache_validity)
+{
+	struct nfs_inode *nfsi = NFS_I(inode);
+
+	nfsi->cache_validity |= NFS_INO_INVALID_CTIME
+		| NFS_INO_INVALID_MTIME
+		| cache_validity;
+
+	if (cinfo->atomic && cinfo->before == inode_peek_iversion_raw(inode)) {
+		nfsi->cache_validity &= ~NFS_INO_REVAL_PAGECACHE;
+		nfsi->attrtimeo_timestamp = jiffies;
+	} else {
+		if (S_ISDIR(inode->i_mode)) {
+			nfsi->cache_validity |= NFS_INO_INVALID_DATA;
+			nfs_force_lookup_revalidate(inode);
+		} else {
+			if (!NFS_PROTO(inode)->have_delegation(inode,
+							       FMODE_READ))
+				nfsi->cache_validity |= NFS_INO_REVAL_PAGECACHE;
+		}
+
+		if (cinfo->before != inode_peek_iversion_raw(inode))
+			nfsi->cache_validity |= NFS_INO_INVALID_ACCESS |
+						NFS_INO_INVALID_ACL |
+						NFS_INO_INVALID_XATTR;
+	}
+	inode_set_iversion_raw(inode, cinfo->after);
+	nfsi->read_cache_jiffies = timestamp;
+	nfsi->attr_gencount = nfs_inc_attr_generation_counter();
+	nfsi->cache_validity &= ~NFS_INO_INVALID_CHANGE;
+
+	if (nfsi->cache_validity & NFS_INO_INVALID_DATA)
+		nfs_fscache_invalidate(inode);
+}
+
+void
+nfs4_update_changeattr(struct inode *dir, struct nfs4_change_info *cinfo,
+		unsigned long timestamp, unsigned long cache_validity)
+{
+	spin_lock(&dir->i_lock);
+	nfs4_update_changeattr_locked(dir, cinfo, timestamp, cache_validity);
+	spin_unlock(&dir->i_lock);
+}
+
+struct nfs4_open_createattrs {
+	struct nfs4_label *label;
+	struct iattr *sattr;
+	const __u32 verf[2];
+};
+
+static bool nfs4_clear_cap_atomic_open_v1(struct nfs_server *server,
+		int err, struct nfs4_exception *exception)
+{
+	if (err != -EINVAL)
+		return false;
+	if (!(server->caps & NFS_CAP_ATOMIC_OPEN_V1))
+		return false;
+	server->caps &= ~NFS_CAP_ATOMIC_OPEN_V1;
+	exception->retry = 1;
+	return true;
+}
+
+static fmode_t _nfs4_ctx_to_accessmode(const struct nfs_open_context *ctx)
+{
+	 return ctx->mode & (FMODE_READ|FMODE_WRITE|FMODE_EXEC);
+}
+
+static fmode_t _nfs4_ctx_to_openmode(const struct nfs_open_context *ctx)
+{
+	fmode_t ret = ctx->mode & (FMODE_READ|FMODE_WRITE);
+
+	return (ctx->mode & FMODE_EXEC) ? FMODE_READ | ret : ret;
+}
+
+static u32
+nfs4_map_atomic_open_share(struct nfs_server *server,
+		fmode_t fmode, int openflags)
+{
+	u32 res = 0;
+
+	switch (fmode & (FMODE_READ | FMODE_WRITE)) {
+	case FMODE_READ:
+		res = NFS4_SHARE_ACCESS_READ;
+		break;
+	case FMODE_WRITE:
+		res = NFS4_SHARE_ACCESS_WRITE;
+		break;
+	case FMODE_READ|FMODE_WRITE:
+		res = NFS4_SHARE_ACCESS_BOTH;
+	}
+	if (!(server->caps & NFS_CAP_ATOMIC_OPEN_V1))
+		goto out;
+	/* Want no delegation if we're using O_DIRECT */
+	if (openflags & O_DIRECT)
+		res |= NFS4_SHARE_WANT_NO_DELEG;
+out:
+	return res;
+}
+
+static enum open_claim_type4
+nfs4_map_atomic_open_claim(struct nfs_server *server,
+		enum open_claim_type4 claim)
+{
+	if (server->caps & NFS_CAP_ATOMIC_OPEN_V1)
+		return claim;
+	switch (claim) {
+	default:
+		return claim;
+	case NFS4_OPEN_CLAIM_FH:
+		return NFS4_OPEN_CLAIM_NULL;
+	case NFS4_OPEN_CLAIM_DELEG_CUR_FH:
+		return NFS4_OPEN_CLAIM_DELEGATE_CUR;
+	case NFS4_OPEN_CLAIM_DELEG_PREV_FH:
+		return NFS4_OPEN_CLAIM_DELEGATE_PREV;
+	}
+}
+
+static void nfs4_init_opendata_res(struct nfs4_opendata *p)
+{
+	p->o_res.f_attr = &p->f_attr;
+	p->o_res.f_label = p->f_label;
+	p->o_res.seqid = p->o_arg.seqid;
+	p->c_res.seqid = p->c_arg.seqid;
+	p->o_res.server = p->o_arg.server;
+	p->o_res.access_request = p->o_arg.access;
+	nfs_fattr_init(&p->f_attr);
+	nfs_fattr_init_names(&p->f_attr, &p->owner_name, &p->group_name);
+}
+
+static struct nfs4_opendata *nfs4_opendata_alloc(struct dentry *dentry,
+		struct nfs4_state_owner *sp, fmode_t fmode, int flags,
+		const struct nfs4_open_createattrs *c,
+		enum open_claim_type4 claim,
+		gfp_t gfp_mask)
+{
+	struct dentry *parent = dget_parent(dentry);
+	struct inode *dir = d_inode(parent);
+	struct nfs_server *server = NFS_SERVER(dir);
+	struct nfs_seqid *(*alloc_seqid)(struct nfs_seqid_counter *, gfp_t);
+	struct nfs4_label *label = (c != NULL) ? c->label : NULL;
+	struct nfs4_opendata *p;
+
+	p = kzalloc(sizeof(*p), gfp_mask);
+	if (p == NULL)
+		goto err;
+
+	p->f_label = nfs4_label_alloc(server, gfp_mask);
+	if (IS_ERR(p->f_label))
+		goto err_free_p;
+
+	p->a_label = nfs4_label_alloc(server, gfp_mask);
+	if (IS_ERR(p->a_label))
+		goto err_free_f;
+
+	alloc_seqid = server->nfs_client->cl_mvops->alloc_seqid;
+	p->o_arg.seqid = alloc_seqid(&sp->so_seqid, gfp_mask);
+	if (IS_ERR(p->o_arg.seqid))
+		goto err_free_label;
+	nfs_sb_active(dentry->d_sb);
+	p->dentry = dget(dentry);
+	p->dir = parent;
+	p->owner = sp;
+	atomic_inc(&sp->so_count);
+	p->o_arg.open_flags = flags;
+	p->o_arg.fmode = fmode & (FMODE_READ|FMODE_WRITE);
+	p->o_arg.claim = nfs4_map_atomic_open_claim(server, claim);
+	p->o_arg.share_access = nfs4_map_atomic_open_share(server,
+			fmode, flags);
+	if (flags & O_CREAT) {
+		p->o_arg.umask = current_umask();
+		p->o_arg.label = nfs4_label_copy(p->a_label, label);
+		if (c->sattr != NULL && c->sattr->ia_valid != 0) {
+			p->o_arg.u.attrs = &p->attrs;
+			memcpy(&p->attrs, c->sattr, sizeof(p->attrs));
+
+			memcpy(p->o_arg.u.verifier.data, c->verf,
+					sizeof(p->o_arg.u.verifier.data));
+		}
+	}
+	/* don't put an ACCESS op in OPEN compound if O_EXCL, because ACCESS
+	 * will return permission denied for all bits until close */
+	if (!(flags & O_EXCL)) {
+		/* ask server to check for all possible rights as results
+		 * are cached */
+		switch (p->o_arg.claim) {
+		default:
+			break;
+		case NFS4_OPEN_CLAIM_NULL:
+		case NFS4_OPEN_CLAIM_FH:
+			p->o_arg.access = NFS4_ACCESS_READ |
+				NFS4_ACCESS_MODIFY |
+				NFS4_ACCESS_EXTEND |
+				NFS4_ACCESS_EXECUTE;
+#ifdef CONFIG_NFS_V4_2
+			if (server->caps & NFS_CAP_XATTR)
+				p->o_arg.access |= NFS4_ACCESS_XAREAD |
+				    NFS4_ACCESS_XAWRITE |
+				    NFS4_ACCESS_XALIST;
+#endif
+		}
+	}
+	p->o_arg.clientid = server->nfs_client->cl_clientid;
+	p->o_arg.id.create_time = ktime_to_ns(sp->so_seqid.create_time);
+	p->o_arg.id.uniquifier = sp->so_seqid.owner_id;
+	p->o_arg.name = &dentry->d_name;
+	p->o_arg.server = server;
+	p->o_arg.bitmask = nfs4_bitmask(server, label);
+	p->o_arg.open_bitmap = &nfs4_fattr_bitmap[0];
+	switch (p->o_arg.claim) {
+	case NFS4_OPEN_CLAIM_NULL:
+	case NFS4_OPEN_CLAIM_DELEGATE_CUR:
+	case NFS4_OPEN_CLAIM_DELEGATE_PREV:
+		p->o_arg.fh = NFS_FH(dir);
+		break;
+	case NFS4_OPEN_CLAIM_PREVIOUS:
+	case NFS4_OPEN_CLAIM_FH:
+	case NFS4_OPEN_CLAIM_DELEG_CUR_FH:
+	case NFS4_OPEN_CLAIM_DELEG_PREV_FH:
+		p->o_arg.fh = NFS_FH(d_inode(dentry));
+	}
+	p->c_arg.fh = &p->o_res.fh;
+	p->c_arg.stateid = &p->o_res.stateid;
+	p->c_arg.seqid = p->o_arg.seqid;
+	nfs4_init_opendata_res(p);
+	kref_init(&p->kref);
+	return p;
+
+err_free_label:
+	nfs4_label_free(p->a_label);
+err_free_f:
+	nfs4_label_free(p->f_label);
+err_free_p:
+	kfree(p);
+err:
+	dput(parent);
+	return NULL;
+}
+
+static void nfs4_opendata_free(struct kref *kref)
+{
+	struct nfs4_opendata *p = container_of(kref,
+			struct nfs4_opendata, kref);
+	struct super_block *sb = p->dentry->d_sb;
+
+	nfs4_lgopen_release(p->lgp);
+	nfs_free_seqid(p->o_arg.seqid);
+	nfs4_sequence_free_slot(&p->o_res.seq_res);
+	if (p->state != NULL)
+		nfs4_put_open_state(p->state);
+	nfs4_put_state_owner(p->owner);
+
+	nfs4_label_free(p->a_label);
+	nfs4_label_free(p->f_label);
+
+	dput(p->dir);
+	dput(p->dentry);
+	nfs_sb_deactive(sb);
+	nfs_fattr_free_names(&p->f_attr);
+	kfree(p->f_attr.mdsthreshold);
+	kfree(p);
+}
+
+static void nfs4_opendata_put(struct nfs4_opendata *p)
+{
+	if (p != NULL)
+		kref_put(&p->kref, nfs4_opendata_free);
+}
+
+static bool nfs4_mode_match_open_stateid(struct nfs4_state *state,
+		fmode_t fmode)
+{
+	switch(fmode & (FMODE_READ|FMODE_WRITE)) {
+	case FMODE_READ|FMODE_WRITE:
+		return state->n_rdwr != 0;
+	case FMODE_WRITE:
+		return state->n_wronly != 0;
+	case FMODE_READ:
+		return state->n_rdonly != 0;
+	}
+	WARN_ON_ONCE(1);
+	return false;
+}
+
+static int can_open_cached(struct nfs4_state *state, fmode_t mode,
+		int open_mode, enum open_claim_type4 claim)
+{
+	int ret = 0;
+
+	if (open_mode & (O_EXCL|O_TRUNC))
+		goto out;
+	switch (claim) {
+	case NFS4_OPEN_CLAIM_NULL:
+	case NFS4_OPEN_CLAIM_FH:
+		goto out;
+	default:
+		break;
+	}
+	switch (mode & (FMODE_READ|FMODE_WRITE)) {
+		case FMODE_READ:
+			ret |= test_bit(NFS_O_RDONLY_STATE, &state->flags) != 0
+				&& state->n_rdonly != 0;
+			break;
+		case FMODE_WRITE:
+			ret |= test_bit(NFS_O_WRONLY_STATE, &state->flags) != 0
+				&& state->n_wronly != 0;
+			break;
+		case FMODE_READ|FMODE_WRITE:
+			ret |= test_bit(NFS_O_RDWR_STATE, &state->flags) != 0
+				&& state->n_rdwr != 0;
+	}
+out:
+	return ret;
+}
+
+static int can_open_delegated(struct nfs_delegation *delegation, fmode_t fmode,
+		enum open_claim_type4 claim)
+{
+	if (delegation == NULL)
+		return 0;
+	if ((delegation->type & fmode) != fmode)
+		return 0;
+	switch (claim) {
+	case NFS4_OPEN_CLAIM_NULL:
+	case NFS4_OPEN_CLAIM_FH:
+		break;
+	case NFS4_OPEN_CLAIM_PREVIOUS:
+		if (!test_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags))
+			break;
+		fallthrough;
+	default:
+		return 0;
+	}
+	nfs_mark_delegation_referenced(delegation);
+	return 1;
+}
+
+static void update_open_stateflags(struct nfs4_state *state, fmode_t fmode)
+{
+	switch (fmode) {
+		case FMODE_WRITE:
+			state->n_wronly++;
+			break;
+		case FMODE_READ:
+			state->n_rdonly++;
+			break;
+		case FMODE_READ|FMODE_WRITE:
+			state->n_rdwr++;
+	}
+	nfs4_state_set_mode_locked(state, state->state | fmode);
+}
+
+#ifdef CONFIG_NFS_V4_1
+static bool nfs_open_stateid_recover_openmode(struct nfs4_state *state)
+{
+	if (state->n_rdonly && !test_bit(NFS_O_RDONLY_STATE, &state->flags))
+		return true;
+	if (state->n_wronly && !test_bit(NFS_O_WRONLY_STATE, &state->flags))
+		return true;
+	if (state->n_rdwr && !test_bit(NFS_O_RDWR_STATE, &state->flags))
+		return true;
+	return false;
+}
+#endif /* CONFIG_NFS_V4_1 */
+
+static void nfs_state_log_update_open_stateid(struct nfs4_state *state)
+{
+	if (test_and_clear_bit(NFS_STATE_CHANGE_WAIT, &state->flags))
+		wake_up_all(&state->waitq);
+}
+
+static void nfs_test_and_clear_all_open_stateid(struct nfs4_state *state)
+{
+	struct nfs_client *clp = state->owner->so_server->nfs_client;
+	bool need_recover = false;
+
+	if (test_and_clear_bit(NFS_O_RDONLY_STATE, &state->flags) && state->n_rdonly)
+		need_recover = true;
+	if (test_and_clear_bit(NFS_O_WRONLY_STATE, &state->flags) && state->n_wronly)
+		need_recover = true;
+	if (test_and_clear_bit(NFS_O_RDWR_STATE, &state->flags) && state->n_rdwr)
+		need_recover = true;
+	if (need_recover)
+		nfs4_state_mark_reclaim_nograce(clp, state);
+}
+
+/*
+ * Check for whether or not the caller may update the open stateid
+ * to the value passed in by stateid.
+ *
+ * Note: This function relies heavily on the server implementing
+ * RFC7530 Section 9.1.4.2, and RFC5661 Section 8.2.2
+ * correctly.
+ * i.e. The stateid seqids have to be initialised to 1, and
+ * are then incremented on every state transition.
+ */
+static bool nfs_stateid_is_sequential(struct nfs4_state *state,
+		const nfs4_stateid *stateid)
+{
+	if (test_bit(NFS_OPEN_STATE, &state->flags)) {
+		/* The common case - we're updating to a new sequence number */
+		if (nfs4_stateid_match_other(stateid, &state->open_stateid)) {
+			if (nfs4_stateid_is_next(&state->open_stateid, stateid))
+				return true;
+			return false;
+		}
+		/* The server returned a new stateid */
+	}
+	/* This is the first OPEN in this generation */
+	if (stateid->seqid == cpu_to_be32(1))
+		return true;
+	return false;
+}
+
+static void nfs_resync_open_stateid_locked(struct nfs4_state *state)
+{
+	if (!(state->n_wronly || state->n_rdonly || state->n_rdwr))
+		return;
+	if (state->n_wronly)
+		set_bit(NFS_O_WRONLY_STATE, &state->flags);
+	if (state->n_rdonly)
+		set_bit(NFS_O_RDONLY_STATE, &state->flags);
+	if (state->n_rdwr)
+		set_bit(NFS_O_RDWR_STATE, &state->flags);
+	set_bit(NFS_OPEN_STATE, &state->flags);
+}
+
+static void nfs_clear_open_stateid_locked(struct nfs4_state *state,
+		nfs4_stateid *stateid, fmode_t fmode)
+{
+	clear_bit(NFS_O_RDWR_STATE, &state->flags);
+	switch (fmode & (FMODE_READ|FMODE_WRITE)) {
+	case FMODE_WRITE:
+		clear_bit(NFS_O_RDONLY_STATE, &state->flags);
+		break;
+	case FMODE_READ:
+		clear_bit(NFS_O_WRONLY_STATE, &state->flags);
+		break;
+	case 0:
+		clear_bit(NFS_O_RDONLY_STATE, &state->flags);
+		clear_bit(NFS_O_WRONLY_STATE, &state->flags);
+		clear_bit(NFS_OPEN_STATE, &state->flags);
+	}
+	if (stateid == NULL)
+		return;
+	/* Handle OPEN+OPEN_DOWNGRADE races */
+	if (nfs4_stateid_match_other(stateid, &state->open_stateid) &&
+	    !nfs4_stateid_is_newer(stateid, &state->open_stateid)) {
+		nfs_resync_open_stateid_locked(state);
+		goto out;
+	}
+	if (test_bit(NFS_DELEGATED_STATE, &state->flags) == 0)
+		nfs4_stateid_copy(&state->stateid, stateid);
+	nfs4_stateid_copy(&state->open_stateid, stateid);
+	trace_nfs4_open_stateid_update(state->inode, stateid, 0);
+out:
+	nfs_state_log_update_open_stateid(state);
+}
+
+static void nfs_clear_open_stateid(struct nfs4_state *state,
+	nfs4_stateid *arg_stateid,
+	nfs4_stateid *stateid, fmode_t fmode)
+{
+	write_seqlock(&state->seqlock);
+	/* Ignore, if the CLOSE argment doesn't match the current stateid */
+	if (nfs4_state_match_open_stateid_other(state, arg_stateid))
+		nfs_clear_open_stateid_locked(state, stateid, fmode);
+	write_sequnlock(&state->seqlock);
+	if (test_bit(NFS_STATE_RECLAIM_NOGRACE, &state->flags))
+		nfs4_schedule_state_manager(state->owner->so_server->nfs_client);
+}
+
+static void nfs_set_open_stateid_locked(struct nfs4_state *state,
+		const nfs4_stateid *stateid, nfs4_stateid *freeme)
+	__must_hold(&state->owner->so_lock)
+	__must_hold(&state->seqlock)
+	__must_hold(RCU)
+
+{
+	DEFINE_WAIT(wait);
+	int status = 0;
+	for (;;) {
+
+		if (nfs_stateid_is_sequential(state, stateid))
+			break;
+
+		if (status)
+			break;
+		/* Rely on seqids for serialisation with NFSv4.0 */
+		if (!nfs4_has_session(NFS_SERVER(state->inode)->nfs_client))
+			break;
+
+		set_bit(NFS_STATE_CHANGE_WAIT, &state->flags);
+		prepare_to_wait(&state->waitq, &wait, TASK_KILLABLE);
+		/*
+		 * Ensure we process the state changes in the same order
+		 * in which the server processed them by delaying the
+		 * update of the stateid until we are in sequence.
+		 */
+		write_sequnlock(&state->seqlock);
+		spin_unlock(&state->owner->so_lock);
+		rcu_read_unlock();
+		trace_nfs4_open_stateid_update_wait(state->inode, stateid, 0);
+
+		if (!fatal_signal_pending(current)) {
+			if (schedule_timeout(5*HZ) == 0)
+				status = -EAGAIN;
+			else
+				status = 0;
+		} else
+			status = -EINTR;
+		finish_wait(&state->waitq, &wait);
+		rcu_read_lock();
+		spin_lock(&state->owner->so_lock);
+		write_seqlock(&state->seqlock);
+	}
+
+	if (test_bit(NFS_OPEN_STATE, &state->flags) &&
+	    !nfs4_stateid_match_other(stateid, &state->open_stateid)) {
+		nfs4_stateid_copy(freeme, &state->open_stateid);
+		nfs_test_and_clear_all_open_stateid(state);
+	}
+
+	if (test_bit(NFS_DELEGATED_STATE, &state->flags) == 0)
+		nfs4_stateid_copy(&state->stateid, stateid);
+	nfs4_stateid_copy(&state->open_stateid, stateid);
+	trace_nfs4_open_stateid_update(state->inode, stateid, status);
+	nfs_state_log_update_open_stateid(state);
+}
+
+static void nfs_state_set_open_stateid(struct nfs4_state *state,
+		const nfs4_stateid *open_stateid,
+		fmode_t fmode,
+		nfs4_stateid *freeme)
+{
+	/*
+	 * Protect the call to nfs4_state_set_mode_locked and
+	 * serialise the stateid update
+	 */
+	write_seqlock(&state->seqlock);
+	nfs_set_open_stateid_locked(state, open_stateid, freeme);
+	switch (fmode) {
+	case FMODE_READ:
+		set_bit(NFS_O_RDONLY_STATE, &state->flags);
+		break;
+	case FMODE_WRITE:
+		set_bit(NFS_O_WRONLY_STATE, &state->flags);
+		break;
+	case FMODE_READ|FMODE_WRITE:
+		set_bit(NFS_O_RDWR_STATE, &state->flags);
+	}
+	set_bit(NFS_OPEN_STATE, &state->flags);
+	write_sequnlock(&state->seqlock);
+}
+
+static void nfs_state_clear_open_state_flags(struct nfs4_state *state)
+{
+	clear_bit(NFS_O_RDWR_STATE, &state->flags);
+	clear_bit(NFS_O_WRONLY_STATE, &state->flags);
+	clear_bit(NFS_O_RDONLY_STATE, &state->flags);
+	clear_bit(NFS_OPEN_STATE, &state->flags);
+}
+
+static void nfs_state_set_delegation(struct nfs4_state *state,
+		const nfs4_stateid *deleg_stateid,
+		fmode_t fmode)
+{
+	/*
+	 * Protect the call to nfs4_state_set_mode_locked and
+	 * serialise the stateid update
+	 */
+	write_seqlock(&state->seqlock);
+	nfs4_stateid_copy(&state->stateid, deleg_stateid);
+	set_bit(NFS_DELEGATED_STATE, &state->flags);
+	write_sequnlock(&state->seqlock);
+}
+
+static void nfs_state_clear_delegation(struct nfs4_state *state)
+{
+	write_seqlock(&state->seqlock);
+	nfs4_stateid_copy(&state->stateid, &state->open_stateid);
+	clear_bit(NFS_DELEGATED_STATE, &state->flags);
+	write_sequnlock(&state->seqlock);
+}
+
+int update_open_stateid(struct nfs4_state *state,
+		const nfs4_stateid *open_stateid,
+		const nfs4_stateid *delegation,
+		fmode_t fmode)
+{
+	struct nfs_server *server = NFS_SERVER(state->inode);
+	struct nfs_client *clp = server->nfs_client;
+	struct nfs_inode *nfsi = NFS_I(state->inode);
+	struct nfs_delegation *deleg_cur;
+	nfs4_stateid freeme = { };
+	int ret = 0;
+
+	fmode &= (FMODE_READ|FMODE_WRITE);
+
+	rcu_read_lock();
+	spin_lock(&state->owner->so_lock);
+	if (open_stateid != NULL) {
+		nfs_state_set_open_stateid(state, open_stateid, fmode, &freeme);
+		ret = 1;
+	}
+
+	deleg_cur = nfs4_get_valid_delegation(state->inode);
+	if (deleg_cur == NULL)
+		goto no_delegation;
+
+	spin_lock(&deleg_cur->lock);
+	if (rcu_dereference(nfsi->delegation) != deleg_cur ||
+	   test_bit(NFS_DELEGATION_RETURNING, &deleg_cur->flags) ||
+	    (deleg_cur->type & fmode) != fmode)
+		goto no_delegation_unlock;
+
+	if (delegation == NULL)
+		delegation = &deleg_cur->stateid;
+	else if (!nfs4_stateid_match_other(&deleg_cur->stateid, delegation))
+		goto no_delegation_unlock;
+
+	nfs_mark_delegation_referenced(deleg_cur);
+	nfs_state_set_delegation(state, &deleg_cur->stateid, fmode);
+	ret = 1;
+no_delegation_unlock:
+	spin_unlock(&deleg_cur->lock);
+no_delegation:
+	if (ret)
+		update_open_stateflags(state, fmode);
+	spin_unlock(&state->owner->so_lock);
+	rcu_read_unlock();
+
+	if (test_bit(NFS_STATE_RECLAIM_NOGRACE, &state->flags))
+		nfs4_schedule_state_manager(clp);
+	if (freeme.type != 0)
+		nfs4_test_and_free_stateid(server, &freeme,
+				state->owner->so_cred);
+
+	return ret;
+}
+
+static bool nfs4_update_lock_stateid(struct nfs4_lock_state *lsp,
+		const nfs4_stateid *stateid)
+{
+	struct nfs4_state *state = lsp->ls_state;
+	bool ret = false;
+
+	spin_lock(&state->state_lock);
+	if (!nfs4_stateid_match_other(stateid, &lsp->ls_stateid))
+		goto out_noupdate;
+	if (!nfs4_stateid_is_newer(stateid, &lsp->ls_stateid))
+		goto out_noupdate;
+	nfs4_stateid_copy(&lsp->ls_stateid, stateid);
+	ret = true;
+out_noupdate:
+	spin_unlock(&state->state_lock);
+	return ret;
+}
+
+static void nfs4_return_incompatible_delegation(struct inode *inode, fmode_t fmode)
+{
+	struct nfs_delegation *delegation;
+
+	fmode &= FMODE_READ|FMODE_WRITE;
+	rcu_read_lock();
+	delegation = nfs4_get_valid_delegation(inode);
+	if (delegation == NULL || (delegation->type & fmode) == fmode) {
+		rcu_read_unlock();
+		return;
+	}
+	rcu_read_unlock();
+	nfs4_inode_return_delegation(inode);
+}
+
+static struct nfs4_state *nfs4_try_open_cached(struct nfs4_opendata *opendata)
+{
+	struct nfs4_state *state = opendata->state;
+	struct nfs_delegation *delegation;
+	int open_mode = opendata->o_arg.open_flags;
+	fmode_t fmode = opendata->o_arg.fmode;
+	enum open_claim_type4 claim = opendata->o_arg.claim;
+	nfs4_stateid stateid;
+	int ret = -EAGAIN;
+
+	for (;;) {
+		spin_lock(&state->owner->so_lock);
+		if (can_open_cached(state, fmode, open_mode, claim)) {
+			update_open_stateflags(state, fmode);
+			spin_unlock(&state->owner->so_lock);
+			goto out_return_state;
+		}
+		spin_unlock(&state->owner->so_lock);
+		rcu_read_lock();
+		delegation = nfs4_get_valid_delegation(state->inode);
+		if (!can_open_delegated(delegation, fmode, claim)) {
+			rcu_read_unlock();
+			break;
+		}
+		/* Save the delegation */
+		nfs4_stateid_copy(&stateid, &delegation->stateid);
+		rcu_read_unlock();
+		nfs_release_seqid(opendata->o_arg.seqid);
+		if (!opendata->is_recover) {
+			ret = nfs_may_open(state->inode, state->owner->so_cred, open_mode);
+			if (ret != 0)
+				goto out;
+		}
+		ret = -EAGAIN;
+
+		/* Try to update the stateid using the delegation */
+		if (update_open_stateid(state, NULL, &stateid, fmode))
+			goto out_return_state;
+	}
+out:
+	return ERR_PTR(ret);
+out_return_state:
+	refcount_inc(&state->count);
+	return state;
+}
+
+static void
+nfs4_opendata_check_deleg(struct nfs4_opendata *data, struct nfs4_state *state)
+{
+	struct nfs_client *clp = NFS_SERVER(state->inode)->nfs_client;
+	struct nfs_delegation *delegation;
+	int delegation_flags = 0;
+
+	rcu_read_lock();
+	delegation = rcu_dereference(NFS_I(state->inode)->delegation);
+	if (delegation)
+		delegation_flags = delegation->flags;
+	rcu_read_unlock();
+	switch (data->o_arg.claim) {
+	default:
+		break;
+	case NFS4_OPEN_CLAIM_DELEGATE_CUR:
+	case NFS4_OPEN_CLAIM_DELEG_CUR_FH:
+		pr_err_ratelimited("NFS: Broken NFSv4 server %s is "
+				   "returning a delegation for "
+				   "OPEN(CLAIM_DELEGATE_CUR)\n",
+				   clp->cl_hostname);
+		return;
+	}
+	if ((delegation_flags & 1UL<<NFS_DELEGATION_NEED_RECLAIM) == 0)
+		nfs_inode_set_delegation(state->inode,
+				data->owner->so_cred,
+				data->o_res.delegation_type,
+				&data->o_res.delegation,
+				data->o_res.pagemod_limit);
+	else
+		nfs_inode_reclaim_delegation(state->inode,
+				data->owner->so_cred,
+				data->o_res.delegation_type,
+				&data->o_res.delegation,
+				data->o_res.pagemod_limit);
+
+	if (data->o_res.do_recall)
+		nfs_async_inode_return_delegation(state->inode,
+						  &data->o_res.delegation);
+}
+
+/*
+ * Check the inode attributes against the CLAIM_PREVIOUS returned attributes
+ * and update the nfs4_state.
+ */
+static struct nfs4_state *
+_nfs4_opendata_reclaim_to_nfs4_state(struct nfs4_opendata *data)
+{
+	struct inode *inode = data->state->inode;
+	struct nfs4_state *state = data->state;
+	int ret;
+
+	if (!data->rpc_done) {
+		if (data->rpc_status)
+			return ERR_PTR(data->rpc_status);
+		return nfs4_try_open_cached(data);
+	}
+
+	ret = nfs_refresh_inode(inode, &data->f_attr);
+	if (ret)
+		return ERR_PTR(ret);
+
+	if (data->o_res.delegation_type != 0)
+		nfs4_opendata_check_deleg(data, state);
+
+	if (!update_open_stateid(state, &data->o_res.stateid,
+				NULL, data->o_arg.fmode))
+		return ERR_PTR(-EAGAIN);
+	refcount_inc(&state->count);
+
+	return state;
+}
+
+static struct inode *
+nfs4_opendata_get_inode(struct nfs4_opendata *data)
+{
+	struct inode *inode;
+
+	switch (data->o_arg.claim) {
+	case NFS4_OPEN_CLAIM_NULL:
+	case NFS4_OPEN_CLAIM_DELEGATE_CUR:
+	case NFS4_OPEN_CLAIM_DELEGATE_PREV:
+		if (!(data->f_attr.valid & NFS_ATTR_FATTR))
+			return ERR_PTR(-EAGAIN);
+		inode = nfs_fhget(data->dir->d_sb, &data->o_res.fh,
+				&data->f_attr, data->f_label);
+		break;
+	default:
+		inode = d_inode(data->dentry);
+		ihold(inode);
+		nfs_refresh_inode(inode, &data->f_attr);
+	}
+	return inode;
+}
+
+static struct nfs4_state *
+nfs4_opendata_find_nfs4_state(struct nfs4_opendata *data)
+{
+	struct nfs4_state *state;
+	struct inode *inode;
+
+	inode = nfs4_opendata_get_inode(data);
+	if (IS_ERR(inode))
+		return ERR_CAST(inode);
+	if (data->state != NULL && data->state->inode == inode) {
+		state = data->state;
+		refcount_inc(&state->count);
+	} else
+		state = nfs4_get_open_state(inode, data->owner);
+	iput(inode);
+	if (state == NULL)
+		state = ERR_PTR(-ENOMEM);
+	return state;
+}
+
+static struct nfs4_state *
+_nfs4_opendata_to_nfs4_state(struct nfs4_opendata *data)
+{
+	struct nfs4_state *state;
+
+	if (!data->rpc_done) {
+		state = nfs4_try_open_cached(data);
+		trace_nfs4_cached_open(data->state);
+		goto out;
+	}
+
+	state = nfs4_opendata_find_nfs4_state(data);
+	if (IS_ERR(state))
+		goto out;
+
+	if (data->o_res.delegation_type != 0)
+		nfs4_opendata_check_deleg(data, state);
+	if (!update_open_stateid(state, &data->o_res.stateid,
+				NULL, data->o_arg.fmode)) {
+		nfs4_put_open_state(state);
+		state = ERR_PTR(-EAGAIN);
+	}
+out:
+	nfs_release_seqid(data->o_arg.seqid);
+	return state;
+}
+
+static struct nfs4_state *
+nfs4_opendata_to_nfs4_state(struct nfs4_opendata *data)
+{
+	struct nfs4_state *ret;
+
+	if (data->o_arg.claim == NFS4_OPEN_CLAIM_PREVIOUS)
+		ret =_nfs4_opendata_reclaim_to_nfs4_state(data);
+	else
+		ret = _nfs4_opendata_to_nfs4_state(data);
+	nfs4_sequence_free_slot(&data->o_res.seq_res);
+	return ret;
+}
+
+static struct nfs_open_context *
+nfs4_state_find_open_context_mode(struct nfs4_state *state, fmode_t mode)
+{
+	struct nfs_inode *nfsi = NFS_I(state->inode);
+	struct nfs_open_context *ctx;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(ctx, &nfsi->open_files, list) {
+		if (ctx->state != state)
+			continue;
+		if ((ctx->mode & mode) != mode)
+			continue;
+		if (!get_nfs_open_context(ctx))
+			continue;
+		rcu_read_unlock();
+		return ctx;
+	}
+	rcu_read_unlock();
+	return ERR_PTR(-ENOENT);
+}
+
+static struct nfs_open_context *
+nfs4_state_find_open_context(struct nfs4_state *state)
+{
+	struct nfs_open_context *ctx;
+
+	ctx = nfs4_state_find_open_context_mode(state, FMODE_READ|FMODE_WRITE);
+	if (!IS_ERR(ctx))
+		return ctx;
+	ctx = nfs4_state_find_open_context_mode(state, FMODE_WRITE);
+	if (!IS_ERR(ctx))
+		return ctx;
+	return nfs4_state_find_open_context_mode(state, FMODE_READ);
+}
+
+static struct nfs4_opendata *nfs4_open_recoverdata_alloc(struct nfs_open_context *ctx,
+		struct nfs4_state *state, enum open_claim_type4 claim)
+{
+	struct nfs4_opendata *opendata;
+
+	opendata = nfs4_opendata_alloc(ctx->dentry, state->owner, 0, 0,
+			NULL, claim, GFP_NOFS);
+	if (opendata == NULL)
+		return ERR_PTR(-ENOMEM);
+	opendata->state = state;
+	refcount_inc(&state->count);
+	return opendata;
+}
+
+static int nfs4_open_recover_helper(struct nfs4_opendata *opendata,
+				    fmode_t fmode)
+{
+	struct nfs4_state *newstate;
+	struct nfs_server *server = NFS_SB(opendata->dentry->d_sb);
+	int openflags = opendata->o_arg.open_flags;
+	int ret;
+
+	if (!nfs4_mode_match_open_stateid(opendata->state, fmode))
+		return 0;
+	opendata->o_arg.fmode = fmode;
+	opendata->o_arg.share_access =
+		nfs4_map_atomic_open_share(server, fmode, openflags);
+	memset(&opendata->o_res, 0, sizeof(opendata->o_res));
+	memset(&opendata->c_res, 0, sizeof(opendata->c_res));
+	nfs4_init_opendata_res(opendata);
+	ret = _nfs4_recover_proc_open(opendata);
+	if (ret != 0)
+		return ret; 
+	newstate = nfs4_opendata_to_nfs4_state(opendata);
+	if (IS_ERR(newstate))
+		return PTR_ERR(newstate);
+	if (newstate != opendata->state)
+		ret = -ESTALE;
+	nfs4_close_state(newstate, fmode);
+	return ret;
+}
+
+static int nfs4_open_recover(struct nfs4_opendata *opendata, struct nfs4_state *state)
+{
+	int ret;
+
+	/* memory barrier prior to reading state->n_* */
+	smp_rmb();
+	ret = nfs4_open_recover_helper(opendata, FMODE_READ|FMODE_WRITE);
+	if (ret != 0)
+		return ret;
+	ret = nfs4_open_recover_helper(opendata, FMODE_WRITE);
+	if (ret != 0)
+		return ret;
+	ret = nfs4_open_recover_helper(opendata, FMODE_READ);
+	if (ret != 0)
+		return ret;
+	/*
+	 * We may have performed cached opens for all three recoveries.
+	 * Check if we need to update the current stateid.
+	 */
+	if (test_bit(NFS_DELEGATED_STATE, &state->flags) == 0 &&
+	    !nfs4_stateid_match(&state->stateid, &state->open_stateid)) {
+		write_seqlock(&state->seqlock);
+		if (test_bit(NFS_DELEGATED_STATE, &state->flags) == 0)
+			nfs4_stateid_copy(&state->stateid, &state->open_stateid);
+		write_sequnlock(&state->seqlock);
+	}
+	return 0;
+}
+
+/*
+ * OPEN_RECLAIM:
+ * 	reclaim state on the server after a reboot.
+ */
+static int _nfs4_do_open_reclaim(struct nfs_open_context *ctx, struct nfs4_state *state)
+{
+	struct nfs_delegation *delegation;
+	struct nfs4_opendata *opendata;
+	fmode_t delegation_type = 0;
+	int status;
+
+	opendata = nfs4_open_recoverdata_alloc(ctx, state,
+			NFS4_OPEN_CLAIM_PREVIOUS);
+	if (IS_ERR(opendata))
+		return PTR_ERR(opendata);
+	rcu_read_lock();
+	delegation = rcu_dereference(NFS_I(state->inode)->delegation);
+	if (delegation != NULL && test_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags) != 0)
+		delegation_type = delegation->type;
+	rcu_read_unlock();
+	opendata->o_arg.u.delegation_type = delegation_type;
+	status = nfs4_open_recover(opendata, state);
+	nfs4_opendata_put(opendata);
+	return status;
+}
+
+static int nfs4_do_open_reclaim(struct nfs_open_context *ctx, struct nfs4_state *state)
+{
+	struct nfs_server *server = NFS_SERVER(state->inode);
+	struct nfs4_exception exception = { };
+	int err;
+	do {
+		err = _nfs4_do_open_reclaim(ctx, state);
+		trace_nfs4_open_reclaim(ctx, 0, err);
+		if (nfs4_clear_cap_atomic_open_v1(server, err, &exception))
+			continue;
+		if (err != -NFS4ERR_DELAY)
+			break;
+		nfs4_handle_exception(server, err, &exception);
+	} while (exception.retry);
+	return err;
+}
+
+static int nfs4_open_reclaim(struct nfs4_state_owner *sp, struct nfs4_state *state)
+{
+	struct nfs_open_context *ctx;
+	int ret;
+
+	ctx = nfs4_state_find_open_context(state);
+	if (IS_ERR(ctx))
+		return -EAGAIN;
+	clear_bit(NFS_DELEGATED_STATE, &state->flags);
+	nfs_state_clear_open_state_flags(state);
+	ret = nfs4_do_open_reclaim(ctx, state);
+	put_nfs_open_context(ctx);
+	return ret;
+}
+
+static int nfs4_handle_delegation_recall_error(struct nfs_server *server, struct nfs4_state *state, const nfs4_stateid *stateid, struct file_lock *fl, int err)
+{
+	switch (err) {
+		default:
+			printk(KERN_ERR "NFS: %s: unhandled error "
+					"%d.\n", __func__, err);
+		case 0:
+		case -ENOENT:
+		case -EAGAIN:
+		case -ESTALE:
+		case -ETIMEDOUT:
+			break;
+		case -NFS4ERR_BADSESSION:
+		case -NFS4ERR_BADSLOT:
+		case -NFS4ERR_BAD_HIGH_SLOT:
+		case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
+		case -NFS4ERR_DEADSESSION:
+			return -EAGAIN;
+		case -NFS4ERR_STALE_CLIENTID:
+		case -NFS4ERR_STALE_STATEID:
+			/* Don't recall a delegation if it was lost */
+			nfs4_schedule_lease_recovery(server->nfs_client);
+			return -EAGAIN;
+		case -NFS4ERR_MOVED:
+			nfs4_schedule_migration_recovery(server);
+			return -EAGAIN;
+		case -NFS4ERR_LEASE_MOVED:
+			nfs4_schedule_lease_moved_recovery(server->nfs_client);
+			return -EAGAIN;
+		case -NFS4ERR_DELEG_REVOKED:
+		case -NFS4ERR_ADMIN_REVOKED:
+		case -NFS4ERR_EXPIRED:
+		case -NFS4ERR_BAD_STATEID:
+		case -NFS4ERR_OPENMODE:
+			nfs_inode_find_state_and_recover(state->inode,
+					stateid);
+			nfs4_schedule_stateid_recovery(server, state);
+			return -EAGAIN;
+		case -NFS4ERR_DELAY:
+		case -NFS4ERR_GRACE:
+			ssleep(1);
+			return -EAGAIN;
+		case -ENOMEM:
+		case -NFS4ERR_DENIED:
+			if (fl) {
+				struct nfs4_lock_state *lsp = fl->fl_u.nfs4_fl.owner;
+				if (lsp)
+					set_bit(NFS_LOCK_LOST, &lsp->ls_flags);
+			}
+			return 0;
+	}
+	return err;
+}
+
+int nfs4_open_delegation_recall(struct nfs_open_context *ctx,
+		struct nfs4_state *state, const nfs4_stateid *stateid)
+{
+	struct nfs_server *server = NFS_SERVER(state->inode);
+	struct nfs4_opendata *opendata;
+	int err = 0;
+
+	opendata = nfs4_open_recoverdata_alloc(ctx, state,
+			NFS4_OPEN_CLAIM_DELEG_CUR_FH);
+	if (IS_ERR(opendata))
+		return PTR_ERR(opendata);
+	nfs4_stateid_copy(&opendata->o_arg.u.delegation, stateid);
+	if (!test_bit(NFS_O_RDWR_STATE, &state->flags)) {
+		err = nfs4_open_recover_helper(opendata, FMODE_READ|FMODE_WRITE);
+		if (err)
+			goto out;
+	}
+	if (!test_bit(NFS_O_WRONLY_STATE, &state->flags)) {
+		err = nfs4_open_recover_helper(opendata, FMODE_WRITE);
+		if (err)
+			goto out;
+	}
+	if (!test_bit(NFS_O_RDONLY_STATE, &state->flags)) {
+		err = nfs4_open_recover_helper(opendata, FMODE_READ);
+		if (err)
+			goto out;
+	}
+	nfs_state_clear_delegation(state);
+out:
+	nfs4_opendata_put(opendata);
+	return nfs4_handle_delegation_recall_error(server, state, stateid, NULL, err);
+}
+
+static void nfs4_open_confirm_prepare(struct rpc_task *task, void *calldata)
+{
+	struct nfs4_opendata *data = calldata;
+
+	nfs4_setup_sequence(data->o_arg.server->nfs_client,
+			   &data->c_arg.seq_args, &data->c_res.seq_res, task);
+}
+
+static void nfs4_open_confirm_done(struct rpc_task *task, void *calldata)
+{
+	struct nfs4_opendata *data = calldata;
+
+	nfs40_sequence_done(task, &data->c_res.seq_res);
+
+	data->rpc_status = task->tk_status;
+	if (data->rpc_status == 0) {
+		nfs4_stateid_copy(&data->o_res.stateid, &data->c_res.stateid);
+		nfs_confirm_seqid(&data->owner->so_seqid, 0);
+		renew_lease(data->o_res.server, data->timestamp);
+		data->rpc_done = true;
+	}
+}
+
+static void nfs4_open_confirm_release(void *calldata)
+{
+	struct nfs4_opendata *data = calldata;
+	struct nfs4_state *state = NULL;
+
+	/* If this request hasn't been cancelled, do nothing */
+	if (!data->cancelled)
+		goto out_free;
+	/* In case of error, no cleanup! */
+	if (!data->rpc_done)
+		goto out_free;
+	state = nfs4_opendata_to_nfs4_state(data);
+	if (!IS_ERR(state))
+		nfs4_close_state(state, data->o_arg.fmode);
+out_free:
+	nfs4_opendata_put(data);
+}
+
+static const struct rpc_call_ops nfs4_open_confirm_ops = {
+	.rpc_call_prepare = nfs4_open_confirm_prepare,
+	.rpc_call_done = nfs4_open_confirm_done,
+	.rpc_release = nfs4_open_confirm_release,
+};
+
+/*
+ * Note: On error, nfs4_proc_open_confirm will free the struct nfs4_opendata
+ */
+static int _nfs4_proc_open_confirm(struct nfs4_opendata *data)
+{
+	struct nfs_server *server = NFS_SERVER(d_inode(data->dir));
+	struct rpc_task *task;
+	struct  rpc_message msg = {
+		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_OPEN_CONFIRM],
+		.rpc_argp = &data->c_arg,
+		.rpc_resp = &data->c_res,
+		.rpc_cred = data->owner->so_cred,
+	};
+	struct rpc_task_setup task_setup_data = {
+		.rpc_client = server->client,
+		.rpc_message = &msg,
+		.callback_ops = &nfs4_open_confirm_ops,
+		.callback_data = data,
+		.workqueue = nfsiod_workqueue,
+		.flags = RPC_TASK_ASYNC | RPC_TASK_CRED_NOREF,
+	};
+	int status;
+
+	nfs4_init_sequence(&data->c_arg.seq_args, &data->c_res.seq_res, 1,
+				data->is_recover);
+	kref_get(&data->kref);
+	data->rpc_done = false;
+	data->rpc_status = 0;
+	data->timestamp = jiffies;
+	task = rpc_run_task(&task_setup_data);
+	if (IS_ERR(task))
+		return PTR_ERR(task);
+	status = rpc_wait_for_completion_task(task);
+	if (status != 0) {
+		data->cancelled = true;
+		smp_wmb();
+	} else
+		status = data->rpc_status;
+	rpc_put_task(task);
+	return status;
+}
+
+static void nfs4_open_prepare(struct rpc_task *task, void *calldata)
+{
+	struct nfs4_opendata *data = calldata;
+	struct nfs4_state_owner *sp = data->owner;
+	struct nfs_client *clp = sp->so_server->nfs_client;
+	enum open_claim_type4 claim = data->o_arg.claim;
+
+	if (nfs_wait_on_sequence(data->o_arg.seqid, task) != 0)
+		goto out_wait;
+	/*
+	 * Check if we still need to send an OPEN call, or if we can use
+	 * a delegation instead.
+	 */
+	if (data->state != NULL) {
+		struct nfs_delegation *delegation;
+
+		if (can_open_cached(data->state, data->o_arg.fmode,
+					data->o_arg.open_flags, claim))
+			goto out_no_action;
+		rcu_read_lock();
+		delegation = nfs4_get_valid_delegation(data->state->inode);
+		if (can_open_delegated(delegation, data->o_arg.fmode, claim))
+			goto unlock_no_action;
+		rcu_read_unlock();
+	}
+	/* Update client id. */
+	data->o_arg.clientid = clp->cl_clientid;
+	switch (claim) {
+	default:
+		break;
+	case NFS4_OPEN_CLAIM_PREVIOUS:
+	case NFS4_OPEN_CLAIM_DELEG_CUR_FH:
+	case NFS4_OPEN_CLAIM_DELEG_PREV_FH:
+		data->o_arg.open_bitmap = &nfs4_open_noattr_bitmap[0];
+		fallthrough;
+	case NFS4_OPEN_CLAIM_FH:
+		task->tk_msg.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_OPEN_NOATTR];
+	}
+	data->timestamp = jiffies;
+	if (nfs4_setup_sequence(data->o_arg.server->nfs_client,
+				&data->o_arg.seq_args,
+				&data->o_res.seq_res,
+				task) != 0)
+		nfs_release_seqid(data->o_arg.seqid);
+
+	/* Set the create mode (note dependency on the session type) */
+	data->o_arg.createmode = NFS4_CREATE_UNCHECKED;
+	if (data->o_arg.open_flags & O_EXCL) {
+		data->o_arg.createmode = NFS4_CREATE_EXCLUSIVE;
+		if (nfs4_has_persistent_session(clp))
+			data->o_arg.createmode = NFS4_CREATE_GUARDED;
+		else if (clp->cl_mvops->minor_version > 0)
+			data->o_arg.createmode = NFS4_CREATE_EXCLUSIVE4_1;
+	}
+	return;
+unlock_no_action:
+	trace_nfs4_cached_open(data->state);
+	rcu_read_unlock();
+out_no_action:
+	task->tk_action = NULL;
+out_wait:
+	nfs4_sequence_done(task, &data->o_res.seq_res);
+}
+
+static void nfs4_open_done(struct rpc_task *task, void *calldata)
+{
+	struct nfs4_opendata *data = calldata;
+
+	data->rpc_status = task->tk_status;
+
+	if (!nfs4_sequence_process(task, &data->o_res.seq_res))
+		return;
+
+	if (task->tk_status == 0) {
+		if (data->o_res.f_attr->valid & NFS_ATTR_FATTR_TYPE) {
+			switch (data->o_res.f_attr->mode & S_IFMT) {
+			case S_IFREG:
+				break;
+			case S_IFLNK:
+				data->rpc_status = -ELOOP;
+				break;
+			case S_IFDIR:
+				data->rpc_status = -EISDIR;
+				break;
+			default:
+				data->rpc_status = -ENOTDIR;
+			}
+		}
+		renew_lease(data->o_res.server, data->timestamp);
+		if (!(data->o_res.rflags & NFS4_OPEN_RESULT_CONFIRM))
+			nfs_confirm_seqid(&data->owner->so_seqid, 0);
+	}
+	data->rpc_done = true;
+}
+
+static void nfs4_open_release(void *calldata)
+{
+	struct nfs4_opendata *data = calldata;
+	struct nfs4_state *state = NULL;
+
+	/* If this request hasn't been cancelled, do nothing */
+	if (!data->cancelled)
+		goto out_free;
+	/* In case of error, no cleanup! */
+	if (data->rpc_status != 0 || !data->rpc_done)
+		goto out_free;
+	/* In case we need an open_confirm, no cleanup! */
+	if (data->o_res.rflags & NFS4_OPEN_RESULT_CONFIRM)
+		goto out_free;
+	state = nfs4_opendata_to_nfs4_state(data);
+	if (!IS_ERR(state))
+		nfs4_close_state(state, data->o_arg.fmode);
+out_free:
+	nfs4_opendata_put(data);
+}
+
+static const struct rpc_call_ops nfs4_open_ops = {
+	.rpc_call_prepare = nfs4_open_prepare,
+	.rpc_call_done = nfs4_open_done,
+	.rpc_release = nfs4_open_release,
+};
+
+static int nfs4_run_open_task(struct nfs4_opendata *data,
+			      struct nfs_open_context *ctx)
+{
+	struct inode *dir = d_inode(data->dir);
+	struct nfs_server *server = NFS_SERVER(dir);
+	struct nfs_openargs *o_arg = &data->o_arg;
+	struct nfs_openres *o_res = &data->o_res;
+	struct rpc_task *task;
+	struct rpc_message msg = {
+		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_OPEN],
+		.rpc_argp = o_arg,
+		.rpc_resp = o_res,
+		.rpc_cred = data->owner->so_cred,
+	};
+	struct rpc_task_setup task_setup_data = {
+		.rpc_client = server->client,
+		.rpc_message = &msg,
+		.callback_ops = &nfs4_open_ops,
+		.callback_data = data,
+		.workqueue = nfsiod_workqueue,
+		.flags = RPC_TASK_ASYNC | RPC_TASK_CRED_NOREF,
+	};
+	int status;
+
+	kref_get(&data->kref);
+	data->rpc_done = false;
+	data->rpc_status = 0;
+	data->cancelled = false;
+	data->is_recover = false;
+	if (!ctx) {
+		nfs4_init_sequence(&o_arg->seq_args, &o_res->seq_res, 1, 1);
+		data->is_recover = true;
+		task_setup_data.flags |= RPC_TASK_TIMEOUT;
+	} else {
+		nfs4_init_sequence(&o_arg->seq_args, &o_res->seq_res, 1, 0);
+		pnfs_lgopen_prepare(data, ctx);
+	}
+	task = rpc_run_task(&task_setup_data);
+	if (IS_ERR(task))
+		return PTR_ERR(task);
+	status = rpc_wait_for_completion_task(task);
+	if (status != 0) {
+		data->cancelled = true;
+		smp_wmb();
+	} else
+		status = data->rpc_status;
+	rpc_put_task(task);
+
+	return status;
+}
+
+static int _nfs4_recover_proc_open(struct nfs4_opendata *data)
+{
+	struct inode *dir = d_inode(data->dir);
+	struct nfs_openres *o_res = &data->o_res;
+	int status;
+
+	status = nfs4_run_open_task(data, NULL);
+	if (status != 0 || !data->rpc_done)
+		return status;
+
+	nfs_fattr_map_and_free_names(NFS_SERVER(dir), &data->f_attr);
+
+	if (o_res->rflags & NFS4_OPEN_RESULT_CONFIRM)
+		status = _nfs4_proc_open_confirm(data);
+
+	return status;
+}
+
+/*
+ * Additional permission checks in order to distinguish between an
+ * open for read, and an open for execute. This works around the
+ * fact that NFSv4 OPEN treats read and execute permissions as being
+ * the same.
+ * Note that in the non-execute case, we want to turn off permission
+ * checking if we just created a new file (POSIX open() semantics).
+ */
+static int nfs4_opendata_access(const struct cred *cred,
+				struct nfs4_opendata *opendata,
+				struct nfs4_state *state, fmode_t fmode,
+				int openflags)
+{
+	struct nfs_access_entry cache;
+	u32 mask, flags;
+
+	/* access call failed or for some reason the server doesn't
+	 * support any access modes -- defer access call until later */
+	if (opendata->o_res.access_supported == 0)
+		return 0;
+
+	mask = 0;
+	/*
+	 * Use openflags to check for exec, because fmode won't
+	 * always have FMODE_EXEC set when file open for exec.
+	 */
+	if (openflags & __FMODE_EXEC) {
+		/* ONLY check for exec rights */
+		if (S_ISDIR(state->inode->i_mode))
+			mask = NFS4_ACCESS_LOOKUP;
+		else
+			mask = NFS4_ACCESS_EXECUTE;
+	} else if ((fmode & FMODE_READ) && !opendata->file_created)
+		mask = NFS4_ACCESS_READ;
+
+	cache.cred = cred;
+	nfs_access_set_mask(&cache, opendata->o_res.access_result);
+	nfs_access_add_cache(state->inode, &cache);
+
+	flags = NFS4_ACCESS_READ | NFS4_ACCESS_EXECUTE | NFS4_ACCESS_LOOKUP;
+	if ((mask & ~cache.mask & flags) == 0)
+		return 0;
+
+	return -EACCES;
+}
+
+/*
+ * Note: On error, nfs4_proc_open will free the struct nfs4_opendata
+ */
+static int _nfs4_proc_open(struct nfs4_opendata *data,
+			   struct nfs_open_context *ctx)
+{
+	struct inode *dir = d_inode(data->dir);
+	struct nfs_server *server = NFS_SERVER(dir);
+	struct nfs_openargs *o_arg = &data->o_arg;
+	struct nfs_openres *o_res = &data->o_res;
+	int status;
+
+	status = nfs4_run_open_task(data, ctx);
+	if (!data->rpc_done)
+		return status;
+	if (status != 0) {
+		if (status == -NFS4ERR_BADNAME &&
+				!(o_arg->open_flags & O_CREAT))
+			return -ENOENT;
+		return status;
+	}
+
+	nfs_fattr_map_and_free_names(server, &data->f_attr);
+
+	if (o_arg->open_flags & O_CREAT) {
+		if (o_arg->open_flags & O_EXCL)
+			data->file_created = true;
+		else if (o_res->cinfo.before != o_res->cinfo.after)
+			data->file_created = true;
+		if (data->file_created ||
+		    inode_peek_iversion_raw(dir) != o_res->cinfo.after)
+			nfs4_update_changeattr(dir, &o_res->cinfo,
+					o_res->f_attr->time_start,
+					NFS_INO_INVALID_DATA);
+	}
+	if ((o_res->rflags & NFS4_OPEN_RESULT_LOCKTYPE_POSIX) == 0)
+		server->caps &= ~NFS_CAP_POSIX_LOCK;
+	if(o_res->rflags & NFS4_OPEN_RESULT_CONFIRM) {
+		status = _nfs4_proc_open_confirm(data);
+		if (status != 0)
+			return status;
+	}
+	if (!(o_res->f_attr->valid & NFS_ATTR_FATTR)) {
+		nfs4_sequence_free_slot(&o_res->seq_res);
+		nfs4_proc_getattr(server, &o_res->fh, o_res->f_attr,
+				o_res->f_label, NULL);
+	}
+	return 0;
+}
+
+/*
+ * OPEN_EXPIRED:
+ * 	reclaim state on the server after a network partition.
+ * 	Assumes caller holds the appropriate lock
+ */
+static int _nfs4_open_expired(struct nfs_open_context *ctx, struct nfs4_state *state)
+{
+	struct nfs4_opendata *opendata;
+	int ret;
+
+	opendata = nfs4_open_recoverdata_alloc(ctx, state, NFS4_OPEN_CLAIM_FH);
+	if (IS_ERR(opendata))
+		return PTR_ERR(opendata);
+	/*
+	 * We're not recovering a delegation, so ask for no delegation.
+	 * Otherwise the recovery thread could deadlock with an outstanding
+	 * delegation return.
+	 */
+	opendata->o_arg.open_flags = O_DIRECT;
+	ret = nfs4_open_recover(opendata, state);
+	if (ret == -ESTALE)
+		d_drop(ctx->dentry);
+	nfs4_opendata_put(opendata);
+	return ret;
+}
+
+static int nfs4_do_open_expired(struct nfs_open_context *ctx, struct nfs4_state *state)
+{
+	struct nfs_server *server = NFS_SERVER(state->inode);
+	struct nfs4_exception exception = { };
+	int err;
+
+	do {
+		err = _nfs4_open_expired(ctx, state);
+		trace_nfs4_open_expired(ctx, 0, err);
+		if (nfs4_clear_cap_atomic_open_v1(server, err, &exception))
+			continue;
+		switch (err) {
+		default:
+			goto out;
+		case -NFS4ERR_GRACE:
+		case -NFS4ERR_DELAY:
+			nfs4_handle_exception(server, err, &exception);
+			err = 0;
+		}
+	} while (exception.retry);
+out:
+	return err;
+}
+
+static int nfs4_open_expired(struct nfs4_state_owner *sp, struct nfs4_state *state)
+{
+	struct nfs_open_context *ctx;
+	int ret;
+
+	ctx = nfs4_state_find_open_context(state);
+	if (IS_ERR(ctx))
+		return -EAGAIN;
+	ret = nfs4_do_open_expired(ctx, state);
+	put_nfs_open_context(ctx);
+	return ret;
+}
+
+static void nfs_finish_clear_delegation_stateid(struct nfs4_state *state,
+		const nfs4_stateid *stateid)
+{
+	nfs_remove_bad_delegation(state->inode, stateid);
+	nfs_state_clear_delegation(state);
+}
+
+static void nfs40_clear_delegation_stateid(struct nfs4_state *state)
+{
+	if (rcu_access_pointer(NFS_I(state->inode)->delegation) != NULL)
+		nfs_finish_clear_delegation_stateid(state, NULL);
+}
+
+static int nfs40_open_expired(struct nfs4_state_owner *sp, struct nfs4_state *state)
+{
+	/* NFSv4.0 doesn't allow for delegation recovery on open expire */
+	nfs40_clear_delegation_stateid(state);
+	nfs_state_clear_open_state_flags(state);
+	return nfs4_open_expired(sp, state);
+}
+
+static int nfs40_test_and_free_expired_stateid(struct nfs_server *server,
+		nfs4_stateid *stateid,
+		const struct cred *cred)
+{
+	return -NFS4ERR_BAD_STATEID;
+}
+
+#if defined(CONFIG_NFS_V4_1)
+static int nfs41_test_and_free_expired_stateid(struct nfs_server *server,
+		nfs4_stateid *stateid,
+		const struct cred *cred)
+{
+	int status;
+
+	switch (stateid->type) {
+	default:
+		break;
+	case NFS4_INVALID_STATEID_TYPE:
+	case NFS4_SPECIAL_STATEID_TYPE:
+		return -NFS4ERR_BAD_STATEID;
+	case NFS4_REVOKED_STATEID_TYPE:
+		goto out_free;
+	}
+
+	status = nfs41_test_stateid(server, stateid, cred);
+	switch (status) {
+	case -NFS4ERR_EXPIRED:
+	case -NFS4ERR_ADMIN_REVOKED:
+	case -NFS4ERR_DELEG_REVOKED:
+		break;
+	default:
+		return status;
+	}
+out_free:
+	/* Ack the revoked state to the server */
+	nfs41_free_stateid(server, stateid, cred, true);
+	return -NFS4ERR_EXPIRED;
+}
+
+static int nfs41_check_delegation_stateid(struct nfs4_state *state)
+{
+	struct nfs_server *server = NFS_SERVER(state->inode);
+	nfs4_stateid stateid;
+	struct nfs_delegation *delegation;
+	const struct cred *cred = NULL;
+	int status, ret = NFS_OK;
+
+	/* Get the delegation credential for use by test/free_stateid */
+	rcu_read_lock();
+	delegation = rcu_dereference(NFS_I(state->inode)->delegation);
+	if (delegation == NULL) {
+		rcu_read_unlock();
+		nfs_state_clear_delegation(state);
+		return NFS_OK;
+	}
+
+	spin_lock(&delegation->lock);
+	nfs4_stateid_copy(&stateid, &delegation->stateid);
+
+	if (!test_and_clear_bit(NFS_DELEGATION_TEST_EXPIRED,
+				&delegation->flags)) {
+		spin_unlock(&delegation->lock);
+		rcu_read_unlock();
+		return NFS_OK;
+	}
+
+	if (delegation->cred)
+		cred = get_cred(delegation->cred);
+	spin_unlock(&delegation->lock);
+	rcu_read_unlock();
+	status = nfs41_test_and_free_expired_stateid(server, &stateid, cred);
+	trace_nfs4_test_delegation_stateid(state, NULL, status);
+	if (status == -NFS4ERR_EXPIRED || status == -NFS4ERR_BAD_STATEID)
+		nfs_finish_clear_delegation_stateid(state, &stateid);
+	else
+		ret = status;
+
+	put_cred(cred);
+	return ret;
+}
+
+static void nfs41_delegation_recover_stateid(struct nfs4_state *state)
+{
+	nfs4_stateid tmp;
+
+	if (test_bit(NFS_DELEGATED_STATE, &state->flags) &&
+	    nfs4_copy_delegation_stateid(state->inode, state->state,
+				&tmp, NULL) &&
+	    nfs4_stateid_match_other(&state->stateid, &tmp))
+		nfs_state_set_delegation(state, &tmp, state->state);
+	else
+		nfs_state_clear_delegation(state);
+}
+
+/**
+ * nfs41_check_expired_locks - possibly free a lock stateid
+ *
+ * @state: NFSv4 state for an inode
+ *
+ * Returns NFS_OK if recovery for this stateid is now finished.
+ * Otherwise a negative NFS4ERR value is returned.
+ */
+static int nfs41_check_expired_locks(struct nfs4_state *state)
+{
+	int status, ret = NFS_OK;
+	struct nfs4_lock_state *lsp, *prev = NULL;
+	struct nfs_server *server = NFS_SERVER(state->inode);
+
+	if (!test_bit(LK_STATE_IN_USE, &state->flags))
+		goto out;
+
+	spin_lock(&state->state_lock);
+	list_for_each_entry(lsp, &state->lock_states, ls_locks) {
+		if (test_bit(NFS_LOCK_INITIALIZED, &lsp->ls_flags)) {
+			const struct cred *cred = lsp->ls_state->owner->so_cred;
+
+			refcount_inc(&lsp->ls_count);
+			spin_unlock(&state->state_lock);
+
+			nfs4_put_lock_state(prev);
+			prev = lsp;
+
+			status = nfs41_test_and_free_expired_stateid(server,
+					&lsp->ls_stateid,
+					cred);
+			trace_nfs4_test_lock_stateid(state, lsp, status);
+			if (status == -NFS4ERR_EXPIRED ||
+			    status == -NFS4ERR_BAD_STATEID) {
+				clear_bit(NFS_LOCK_INITIALIZED, &lsp->ls_flags);
+				lsp->ls_stateid.type = NFS4_INVALID_STATEID_TYPE;
+				if (!recover_lost_locks)
+					set_bit(NFS_LOCK_LOST, &lsp->ls_flags);
+			} else if (status != NFS_OK) {
+				ret = status;
+				nfs4_put_lock_state(prev);
+				goto out;
+			}
+			spin_lock(&state->state_lock);
+		}
+	}
+	spin_unlock(&state->state_lock);
+	nfs4_put_lock_state(prev);
+out:
+	return ret;
+}
+
+/**
+ * nfs41_check_open_stateid - possibly free an open stateid
+ *
+ * @state: NFSv4 state for an inode
+ *
+ * Returns NFS_OK if recovery for this stateid is now finished.
+ * Otherwise a negative NFS4ERR value is returned.
+ */
+static int nfs41_check_open_stateid(struct nfs4_state *state)
+{
+	struct nfs_server *server = NFS_SERVER(state->inode);
+	nfs4_stateid *stateid = &state->open_stateid;
+	const struct cred *cred = state->owner->so_cred;
+	int status;
+
+	if (test_bit(NFS_OPEN_STATE, &state->flags) == 0)
+		return -NFS4ERR_BAD_STATEID;
+	status = nfs41_test_and_free_expired_stateid(server, stateid, cred);
+	trace_nfs4_test_open_stateid(state, NULL, status);
+	if (status == -NFS4ERR_EXPIRED || status == -NFS4ERR_BAD_STATEID) {
+		nfs_state_clear_open_state_flags(state);
+		stateid->type = NFS4_INVALID_STATEID_TYPE;
+		return status;
+	}
+	if (nfs_open_stateid_recover_openmode(state))
+		return -NFS4ERR_OPENMODE;
+	return NFS_OK;
+}
+
+static int nfs41_open_expired(struct nfs4_state_owner *sp, struct nfs4_state *state)
+{
+	int status;
+
+	status = nfs41_check_delegation_stateid(state);
+	if (status != NFS_OK)
+		return status;
+	nfs41_delegation_recover_stateid(state);
+
+	status = nfs41_check_expired_locks(state);
+	if (status != NFS_OK)
+		return status;
+	status = nfs41_check_open_stateid(state);
+	if (status != NFS_OK)
+		status = nfs4_open_expired(sp, state);
+	return status;
+}
+#endif
+
+/*
+ * on an EXCLUSIVE create, the server should send back a bitmask with FATTR4-*
+ * fields corresponding to attributes that were used to store the verifier.
+ * Make sure we clobber those fields in the later setattr call
+ */
+static unsigned nfs4_exclusive_attrset(struct nfs4_opendata *opendata,
+				struct iattr *sattr, struct nfs4_label **label)
+{
+	const __u32 *bitmask = opendata->o_arg.server->exclcreat_bitmask;
+	__u32 attrset[3];
+	unsigned ret;
+	unsigned i;
+
+	for (i = 0; i < ARRAY_SIZE(attrset); i++) {
+		attrset[i] = opendata->o_res.attrset[i];
+		if (opendata->o_arg.createmode == NFS4_CREATE_EXCLUSIVE4_1)
+			attrset[i] &= ~bitmask[i];
+	}
+
+	ret = (opendata->o_arg.createmode == NFS4_CREATE_EXCLUSIVE) ?
+		sattr->ia_valid : 0;
+
+	if ((attrset[1] & (FATTR4_WORD1_TIME_ACCESS|FATTR4_WORD1_TIME_ACCESS_SET))) {
+		if (sattr->ia_valid & ATTR_ATIME_SET)
+			ret |= ATTR_ATIME_SET;
+		else
+			ret |= ATTR_ATIME;
+	}
+
+	if ((attrset[1] & (FATTR4_WORD1_TIME_MODIFY|FATTR4_WORD1_TIME_MODIFY_SET))) {
+		if (sattr->ia_valid & ATTR_MTIME_SET)
+			ret |= ATTR_MTIME_SET;
+		else
+			ret |= ATTR_MTIME;
+	}
+
+	if (!(attrset[2] & FATTR4_WORD2_SECURITY_LABEL))
+		*label = NULL;
+	return ret;
+}
+
+static int _nfs4_open_and_get_state(struct nfs4_opendata *opendata,
+		int flags, struct nfs_open_context *ctx)
+{
+	struct nfs4_state_owner *sp = opendata->owner;
+	struct nfs_server *server = sp->so_server;
+	struct dentry *dentry;
+	struct nfs4_state *state;
+	fmode_t acc_mode = _nfs4_ctx_to_accessmode(ctx);
+	struct inode *dir = d_inode(opendata->dir);
+	unsigned long dir_verifier;
+	unsigned int seq;
+	int ret;
+
+	seq = raw_seqcount_begin(&sp->so_reclaim_seqcount);
+	dir_verifier = nfs_save_change_attribute(dir);
+
+	ret = _nfs4_proc_open(opendata, ctx);
+	if (ret != 0)
+		goto out;
+
+	state = _nfs4_opendata_to_nfs4_state(opendata);
+	ret = PTR_ERR(state);
+	if (IS_ERR(state))
+		goto out;
+	ctx->state = state;
+	if (server->caps & NFS_CAP_POSIX_LOCK)
+		set_bit(NFS_STATE_POSIX_LOCKS, &state->flags);
+	if (opendata->o_res.rflags & NFS4_OPEN_RESULT_MAY_NOTIFY_LOCK)
+		set_bit(NFS_STATE_MAY_NOTIFY_LOCK, &state->flags);
+
+	dentry = opendata->dentry;
+	if (d_really_is_negative(dentry)) {
+		struct dentry *alias;
+		d_drop(dentry);
+		alias = d_exact_alias(dentry, state->inode);
+		if (!alias)
+			alias = d_splice_alias(igrab(state->inode), dentry);
+		/* d_splice_alias() can't fail here - it's a non-directory */
+		if (alias) {
+			dput(ctx->dentry);
+			ctx->dentry = dentry = alias;
+		}
+	}
+
+	switch(opendata->o_arg.claim) {
+	default:
+		break;
+	case NFS4_OPEN_CLAIM_NULL:
+	case NFS4_OPEN_CLAIM_DELEGATE_CUR:
+	case NFS4_OPEN_CLAIM_DELEGATE_PREV:
+		if (!opendata->rpc_done)
+			break;
+		if (opendata->o_res.delegation_type != 0)
+			dir_verifier = nfs_save_change_attribute(dir);
+		nfs_set_verifier(dentry, dir_verifier);
+	}
+
+	/* Parse layoutget results before we check for access */
+	pnfs_parse_lgopen(state->inode, opendata->lgp, ctx);
+
+	ret = nfs4_opendata_access(sp->so_cred, opendata, state,
+			acc_mode, flags);
+	if (ret != 0)
+		goto out;
+
+	if (d_inode(dentry) == state->inode) {
+		nfs_inode_attach_open_context(ctx);
+		if (read_seqcount_retry(&sp->so_reclaim_seqcount, seq))
+			nfs4_schedule_stateid_recovery(server, state);
+	}
+
+out:
+	if (!opendata->cancelled) {
+		if (opendata->lgp) {
+			nfs4_lgopen_release(opendata->lgp);
+			opendata->lgp = NULL;
+		}
+		nfs4_sequence_free_slot(&opendata->o_res.seq_res);
+	}
+	return ret;
+}
+
+/*
+ * Returns a referenced nfs4_state
+ */
+static int _nfs4_do_open(struct inode *dir,
+			struct nfs_open_context *ctx,
+			int flags,
+			const struct nfs4_open_createattrs *c,
+			int *opened)
+{
+	struct nfs4_state_owner  *sp;
+	struct nfs4_state     *state = NULL;
+	struct nfs_server       *server = NFS_SERVER(dir);
+	struct nfs4_opendata *opendata;
+	struct dentry *dentry = ctx->dentry;
+	const struct cred *cred = ctx->cred;
+	struct nfs4_threshold **ctx_th = &ctx->mdsthreshold;
+	fmode_t fmode = _nfs4_ctx_to_openmode(ctx);
+	enum open_claim_type4 claim = NFS4_OPEN_CLAIM_NULL;
+	struct iattr *sattr = c->sattr;
+	struct nfs4_label *label = c->label;
+	struct nfs4_label *olabel = NULL;
+	int status;
+
+	/* Protect against reboot recovery conflicts */
+	status = -ENOMEM;
+	sp = nfs4_get_state_owner(server, cred, GFP_KERNEL);
+	if (sp == NULL) {
+		dprintk("nfs4_do_open: nfs4_get_state_owner failed!\n");
+		goto out_err;
+	}
+	status = nfs4_client_recover_expired_lease(server->nfs_client);
+	if (status != 0)
+		goto err_put_state_owner;
+	if (d_really_is_positive(dentry))
+		nfs4_return_incompatible_delegation(d_inode(dentry), fmode);
+	status = -ENOMEM;
+	if (d_really_is_positive(dentry))
+		claim = NFS4_OPEN_CLAIM_FH;
+	opendata = nfs4_opendata_alloc(dentry, sp, fmode, flags,
+			c, claim, GFP_KERNEL);
+	if (opendata == NULL)
+		goto err_put_state_owner;
+
+	if (label) {
+		olabel = nfs4_label_alloc(server, GFP_KERNEL);
+		if (IS_ERR(olabel)) {
+			status = PTR_ERR(olabel);
+			goto err_opendata_put;
+		}
+	}
+
+	if (server->attr_bitmask[2] & FATTR4_WORD2_MDSTHRESHOLD) {
+		if (!opendata->f_attr.mdsthreshold) {
+			opendata->f_attr.mdsthreshold = pnfs_mdsthreshold_alloc();
+			if (!opendata->f_attr.mdsthreshold)
+				goto err_free_label;
+		}
+		opendata->o_arg.open_bitmap = &nfs4_pnfs_open_bitmap[0];
+	}
+	if (d_really_is_positive(dentry))
+		opendata->state = nfs4_get_open_state(d_inode(dentry), sp);
+
+	status = _nfs4_open_and_get_state(opendata, flags, ctx);
+	if (status != 0)
+		goto err_free_label;
+	state = ctx->state;
+
+	if ((opendata->o_arg.open_flags & (O_CREAT|O_EXCL)) == (O_CREAT|O_EXCL) &&
+	    (opendata->o_arg.createmode != NFS4_CREATE_GUARDED)) {
+		unsigned attrs = nfs4_exclusive_attrset(opendata, sattr, &label);
+		/*
+		 * send create attributes which was not set by open
+		 * with an extra setattr.
+		 */
+		if (attrs || label) {
+			unsigned ia_old = sattr->ia_valid;
+
+			sattr->ia_valid = attrs;
+			nfs_fattr_init(opendata->o_res.f_attr);
+			status = nfs4_do_setattr(state->inode, cred,
+					opendata->o_res.f_attr, sattr,
+					ctx, label, olabel);
+			if (status == 0) {
+				nfs_setattr_update_inode(state->inode, sattr,
+						opendata->o_res.f_attr);
+				nfs_setsecurity(state->inode, opendata->o_res.f_attr, olabel);
+			}
+			sattr->ia_valid = ia_old;
+		}
+	}
+	if (opened && opendata->file_created)
+		*opened = 1;
+
+	if (pnfs_use_threshold(ctx_th, opendata->f_attr.mdsthreshold, server)) {
+		*ctx_th = opendata->f_attr.mdsthreshold;
+		opendata->f_attr.mdsthreshold = NULL;
+	}
+
+	nfs4_label_free(olabel);
+
+	nfs4_opendata_put(opendata);
+	nfs4_put_state_owner(sp);
+	return 0;
+err_free_label:
+	nfs4_label_free(olabel);
+err_opendata_put:
+	nfs4_opendata_put(opendata);
+err_put_state_owner:
+	nfs4_put_state_owner(sp);
+out_err:
+	return status;
+}
+
+
+static struct nfs4_state *nfs4_do_open(struct inode *dir,
+					struct nfs_open_context *ctx,
+					int flags,
+					struct iattr *sattr,
+					struct nfs4_label *label,
+					int *opened)
+{
+	struct nfs_server *server = NFS_SERVER(dir);
+	struct nfs4_exception exception = {
+		.interruptible = true,
+	};
+	struct nfs4_state *res;
+	struct nfs4_open_createattrs c = {
+		.label = label,
+		.sattr = sattr,
+		.verf = {
+			[0] = (__u32)jiffies,
+			[1] = (__u32)current->pid,
+		},
+	};
+	int status;
+
+	do {
+		status = _nfs4_do_open(dir, ctx, flags, &c, opened);
+		res = ctx->state;
+		trace_nfs4_open_file(ctx, flags, status);
+		if (status == 0)
+			break;
+		/* NOTE: BAD_SEQID means the server and client disagree about the
+		 * book-keeping w.r.t. state-changing operations
+		 * (OPEN/CLOSE/LOCK/LOCKU...)
+		 * It is actually a sign of a bug on the client or on the server.
+		 *
+		 * If we receive a BAD_SEQID error in the particular case of
+		 * doing an OPEN, we assume that nfs_increment_open_seqid() will
+		 * have unhashed the old state_owner for us, and that we can
+		 * therefore safely retry using a new one. We should still warn
+		 * the user though...
+		 */
+		if (status == -NFS4ERR_BAD_SEQID) {
+			pr_warn_ratelimited("NFS: v4 server %s "
+					" returned a bad sequence-id error!\n",
+					NFS_SERVER(dir)->nfs_client->cl_hostname);
+			exception.retry = 1;
+			continue;
+		}
+		/*
+		 * BAD_STATEID on OPEN means that the server cancelled our
+		 * state before it received the OPEN_CONFIRM.
+		 * Recover by retrying the request as per the discussion
+		 * on Page 181 of RFC3530.
+		 */
+		if (status == -NFS4ERR_BAD_STATEID) {
+			exception.retry = 1;
+			continue;
+		}
+		if (status == -NFS4ERR_EXPIRED) {
+			nfs4_schedule_lease_recovery(server->nfs_client);
+			exception.retry = 1;
+			continue;
+		}
+		if (status == -EAGAIN) {
+			/* We must have found a delegation */
+			exception.retry = 1;
+			continue;
+		}
+		if (nfs4_clear_cap_atomic_open_v1(server, status, &exception))
+			continue;
+		res = ERR_PTR(nfs4_handle_exception(server,
+					status, &exception));
+	} while (exception.retry);
+	return res;
+}
+
+static int _nfs4_do_setattr(struct inode *inode,
+			    struct nfs_setattrargs *arg,
+			    struct nfs_setattrres *res,
+			    const struct cred *cred,
+			    struct nfs_open_context *ctx)
+{
+	struct nfs_server *server = NFS_SERVER(inode);
+	struct rpc_message msg = {
+		.rpc_proc	= &nfs4_procedures[NFSPROC4_CLNT_SETATTR],
+		.rpc_argp	= arg,
+		.rpc_resp	= res,
+		.rpc_cred	= cred,
+	};
+	const struct cred *delegation_cred = NULL;
+	unsigned long timestamp = jiffies;
+	bool truncate;
+	int status;
+
+	nfs_fattr_init(res->fattr);
+
+	/* Servers should only apply open mode checks for file size changes */
+	truncate = (arg->iap->ia_valid & ATTR_SIZE) ? true : false;
+	if (!truncate) {
+		nfs4_inode_make_writeable(inode);
+		goto zero_stateid;
+	}
+
+	if (nfs4_copy_delegation_stateid(inode, FMODE_WRITE, &arg->stateid, &delegation_cred)) {
+		/* Use that stateid */
+	} else if (ctx != NULL && ctx->state) {
+		struct nfs_lock_context *l_ctx;
+		if (!nfs4_valid_open_stateid(ctx->state))
+			return -EBADF;
+		l_ctx = nfs_get_lock_context(ctx);
+		if (IS_ERR(l_ctx))
+			return PTR_ERR(l_ctx);
+		status = nfs4_select_rw_stateid(ctx->state, FMODE_WRITE, l_ctx,
+						&arg->stateid, &delegation_cred);
+		nfs_put_lock_context(l_ctx);
+		if (status == -EIO)
+			return -EBADF;
+		else if (status == -EAGAIN)
+			goto zero_stateid;
+	} else {
+zero_stateid:
+		nfs4_stateid_copy(&arg->stateid, &zero_stateid);
+	}
+	if (delegation_cred)
+		msg.rpc_cred = delegation_cred;
+
+	status = nfs4_call_sync(server->client, server, &msg, &arg->seq_args, &res->seq_res, 1);
+
+	put_cred(delegation_cred);
+	if (status == 0 && ctx != NULL)
+		renew_lease(server, timestamp);
+	trace_nfs4_setattr(inode, &arg->stateid, status);
+	return status;
+}
+
+static int nfs4_do_setattr(struct inode *inode, const struct cred *cred,
+			   struct nfs_fattr *fattr, struct iattr *sattr,
+			   struct nfs_open_context *ctx, struct nfs4_label *ilabel,
+			   struct nfs4_label *olabel)
+{
+	struct nfs_server *server = NFS_SERVER(inode);
+	__u32 bitmask[NFS4_BITMASK_SZ];
+	struct nfs4_state *state = ctx ? ctx->state : NULL;
+	struct nfs_setattrargs	arg = {
+		.fh		= NFS_FH(inode),
+		.iap		= sattr,
+		.server		= server,
+		.bitmask = bitmask,
+		.label		= ilabel,
+	};
+	struct nfs_setattrres  res = {
+		.fattr		= fattr,
+		.label		= olabel,
+		.server		= server,
+	};
+	struct nfs4_exception exception = {
+		.state = state,
+		.inode = inode,
+		.stateid = &arg.stateid,
+	};
+	int err;
+
+	do {
+		nfs4_bitmap_copy_adjust_setattr(bitmask,
+				nfs4_bitmask(server, olabel),
+				inode);
+
+		err = _nfs4_do_setattr(inode, &arg, &res, cred, ctx);
+		switch (err) {
+		case -NFS4ERR_OPENMODE:
+			if (!(sattr->ia_valid & ATTR_SIZE)) {
+				pr_warn_once("NFSv4: server %s is incorrectly "
+						"applying open mode checks to "
+						"a SETATTR that is not "
+						"changing file size.\n",
+						server->nfs_client->cl_hostname);
+			}
+			if (state && !(state->state & FMODE_WRITE)) {
+				err = -EBADF;
+				if (sattr->ia_valid & ATTR_OPEN)
+					err = -EACCES;
+				goto out;
+			}
+		}
+		err = nfs4_handle_exception(server, err, &exception);
+	} while (exception.retry);
+out:
+	return err;
+}
+
+static bool
+nfs4_wait_on_layoutreturn(struct inode *inode, struct rpc_task *task)
+{
+	if (inode == NULL || !nfs_have_layout(inode))
+		return false;
+
+	return pnfs_wait_on_layoutreturn(inode, task);
+}
+
+/*
+ * Update the seqid of an open stateid
+ */
+static void nfs4_sync_open_stateid(nfs4_stateid *dst,
+		struct nfs4_state *state)
+{
+	__be32 seqid_open;
+	u32 dst_seqid;
+	int seq;
+
+	for (;;) {
+		if (!nfs4_valid_open_stateid(state))
+			break;
+		seq = read_seqbegin(&state->seqlock);
+		if (!nfs4_state_match_open_stateid_other(state, dst)) {
+			nfs4_stateid_copy(dst, &state->open_stateid);
+			if (read_seqretry(&state->seqlock, seq))
+				continue;
+			break;
+		}
+		seqid_open = state->open_stateid.seqid;
+		if (read_seqretry(&state->seqlock, seq))
+			continue;
+
+		dst_seqid = be32_to_cpu(dst->seqid);
+		if ((s32)(dst_seqid - be32_to_cpu(seqid_open)) < 0)
+			dst->seqid = seqid_open;
+		break;
+	}
+}
+
+/*
+ * Update the seqid of an open stateid after receiving
+ * NFS4ERR_OLD_STATEID
+ */
+static bool nfs4_refresh_open_old_stateid(nfs4_stateid *dst,
+		struct nfs4_state *state)
+{
+	__be32 seqid_open;
+	u32 dst_seqid;
+	bool ret;
+	int seq, status = -EAGAIN;
+	DEFINE_WAIT(wait);
+
+	for (;;) {
+		ret = false;
+		if (!nfs4_valid_open_stateid(state))
+			break;
+		seq = read_seqbegin(&state->seqlock);
+		if (!nfs4_state_match_open_stateid_other(state, dst)) {
+			if (read_seqretry(&state->seqlock, seq))
+				continue;
+			break;
+		}
+
+		write_seqlock(&state->seqlock);
+		seqid_open = state->open_stateid.seqid;
+
+		dst_seqid = be32_to_cpu(dst->seqid);
+
+		/* Did another OPEN bump the state's seqid?  try again: */
+		if ((s32)(be32_to_cpu(seqid_open) - dst_seqid) > 0) {
+			dst->seqid = seqid_open;
+			write_sequnlock(&state->seqlock);
+			ret = true;
+			break;
+		}
+
+		/* server says we're behind but we haven't seen the update yet */
+		set_bit(NFS_STATE_CHANGE_WAIT, &state->flags);
+		prepare_to_wait(&state->waitq, &wait, TASK_KILLABLE);
+		write_sequnlock(&state->seqlock);
+		trace_nfs4_close_stateid_update_wait(state->inode, dst, 0);
+
+		if (fatal_signal_pending(current))
+			status = -EINTR;
+		else
+			if (schedule_timeout(5*HZ) != 0)
+				status = 0;
+
+		finish_wait(&state->waitq, &wait);
+
+		if (!status)
+			continue;
+		if (status == -EINTR)
+			break;
+
+		/* we slept the whole 5 seconds, we must have lost a seqid */
+		dst->seqid = cpu_to_be32(dst_seqid + 1);
+		ret = true;
+		break;
+	}
+
+	return ret;
+}
+
+struct nfs4_closedata {
+	struct inode *inode;
+	struct nfs4_state *state;
+	struct nfs_closeargs arg;
+	struct nfs_closeres res;
+	struct {
+		struct nfs4_layoutreturn_args arg;
+		struct nfs4_layoutreturn_res res;
+		struct nfs4_xdr_opaque_data ld_private;
+		u32 roc_barrier;
+		bool roc;
+	} lr;
+	struct nfs_fattr fattr;
+	unsigned long timestamp;
+};
+
+static void nfs4_free_closedata(void *data)
+{
+	struct nfs4_closedata *calldata = data;
+	struct nfs4_state_owner *sp = calldata->state->owner;
+	struct super_block *sb = calldata->state->inode->i_sb;
+
+	if (calldata->lr.roc)
+		pnfs_roc_release(&calldata->lr.arg, &calldata->lr.res,
+				calldata->res.lr_ret);
+	nfs4_put_open_state(calldata->state);
+	nfs_free_seqid(calldata->arg.seqid);
+	nfs4_put_state_owner(sp);
+	nfs_sb_deactive(sb);
+	kfree(calldata);
+}
+
+static void nfs4_close_done(struct rpc_task *task, void *data)
+{
+	struct nfs4_closedata *calldata = data;
+	struct nfs4_state *state = calldata->state;
+	struct nfs_server *server = NFS_SERVER(calldata->inode);
+	nfs4_stateid *res_stateid = NULL;
+	struct nfs4_exception exception = {
+		.state = state,
+		.inode = calldata->inode,
+		.stateid = &calldata->arg.stateid,
+	};
+
+	dprintk("%s: begin!\n", __func__);
+	if (!nfs4_sequence_done(task, &calldata->res.seq_res))
+		return;
+	trace_nfs4_close(state, &calldata->arg, &calldata->res, task->tk_status);
+
+	/* Handle Layoutreturn errors */
+	if (pnfs_roc_done(task, &calldata->arg.lr_args, &calldata->res.lr_res,
+			  &calldata->res.lr_ret) == -EAGAIN)
+		goto out_restart;
+
+	/* hmm. we are done with the inode, and in the process of freeing
+	 * the state_owner. we keep this around to process errors
+	 */
+	switch (task->tk_status) {
+		case 0:
+			res_stateid = &calldata->res.stateid;
+			renew_lease(server, calldata->timestamp);
+			break;
+		case -NFS4ERR_ACCESS:
+			if (calldata->arg.bitmask != NULL) {
+				calldata->arg.bitmask = NULL;
+				calldata->res.fattr = NULL;
+				goto out_restart;
+
+			}
+			break;
+		case -NFS4ERR_OLD_STATEID:
+			/* Did we race with OPEN? */
+			if (nfs4_refresh_open_old_stateid(&calldata->arg.stateid,
+						state))
+				goto out_restart;
+			goto out_release;
+		case -NFS4ERR_ADMIN_REVOKED:
+		case -NFS4ERR_STALE_STATEID:
+		case -NFS4ERR_EXPIRED:
+			nfs4_free_revoked_stateid(server,
+					&calldata->arg.stateid,
+					task->tk_msg.rpc_cred);
+			fallthrough;
+		case -NFS4ERR_BAD_STATEID:
+			if (calldata->arg.fmode == 0)
+				break;
+			fallthrough;
+		default:
+			task->tk_status = nfs4_async_handle_exception(task,
+					server, task->tk_status, &exception);
+			if (exception.retry)
+				goto out_restart;
+	}
+	nfs_clear_open_stateid(state, &calldata->arg.stateid,
+			res_stateid, calldata->arg.fmode);
+out_release:
+	task->tk_status = 0;
+	nfs_release_seqid(calldata->arg.seqid);
+	nfs_refresh_inode(calldata->inode, &calldata->fattr);
+	dprintk("%s: done, ret = %d!\n", __func__, task->tk_status);
+	return;
+out_restart:
+	task->tk_status = 0;
+	rpc_restart_call_prepare(task);
+	goto out_release;
+}
+
+static void nfs4_close_prepare(struct rpc_task *task, void *data)
+{
+	struct nfs4_closedata *calldata = data;
+	struct nfs4_state *state = calldata->state;
+	struct inode *inode = calldata->inode;
+	struct nfs_server *server = NFS_SERVER(inode);
+	struct pnfs_layout_hdr *lo;
+	bool is_rdonly, is_wronly, is_rdwr;
+	int call_close = 0;
+
+	dprintk("%s: begin!\n", __func__);
+	if (nfs_wait_on_sequence(calldata->arg.seqid, task) != 0)
+		goto out_wait;
+
+	task->tk_msg.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_OPEN_DOWNGRADE];
+	spin_lock(&state->owner->so_lock);
+	is_rdwr = test_bit(NFS_O_RDWR_STATE, &state->flags);
+	is_rdonly = test_bit(NFS_O_RDONLY_STATE, &state->flags);
+	is_wronly = test_bit(NFS_O_WRONLY_STATE, &state->flags);
+	/* Calculate the change in open mode */
+	calldata->arg.fmode = 0;
+	if (state->n_rdwr == 0) {
+		if (state->n_rdonly == 0)
+			call_close |= is_rdonly;
+		else if (is_rdonly)
+			calldata->arg.fmode |= FMODE_READ;
+		if (state->n_wronly == 0)
+			call_close |= is_wronly;
+		else if (is_wronly)
+			calldata->arg.fmode |= FMODE_WRITE;
+		if (calldata->arg.fmode != (FMODE_READ|FMODE_WRITE))
+			call_close |= is_rdwr;
+	} else if (is_rdwr)
+		calldata->arg.fmode |= FMODE_READ|FMODE_WRITE;
+
+	nfs4_sync_open_stateid(&calldata->arg.stateid, state);
+	if (!nfs4_valid_open_stateid(state))
+		call_close = 0;
+	spin_unlock(&state->owner->so_lock);
+
+	if (!call_close) {
+		/* Note: exit _without_ calling nfs4_close_done */
+		goto out_no_action;
+	}
+
+	if (!calldata->lr.roc && nfs4_wait_on_layoutreturn(inode, task)) {
+		nfs_release_seqid(calldata->arg.seqid);
+		goto out_wait;
+	}
+
+	lo = calldata->arg.lr_args ? calldata->arg.lr_args->layout : NULL;
+	if (lo && !pnfs_layout_is_valid(lo)) {
+		calldata->arg.lr_args = NULL;
+		calldata->res.lr_res = NULL;
+	}
+
+	if (calldata->arg.fmode == 0)
+		task->tk_msg.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_CLOSE];
+
+	if (calldata->arg.fmode == 0 || calldata->arg.fmode == FMODE_READ) {
+		/* Close-to-open cache consistency revalidation */
+		if (!nfs4_have_delegation(inode, FMODE_READ)) {
+			nfs4_bitmask_set(calldata->arg.bitmask_store,
+					 server->cache_consistency_bitmask,
+					 inode, server, NULL);
+			calldata->arg.bitmask = calldata->arg.bitmask_store;
+		} else
+			calldata->arg.bitmask = NULL;
+	}
+
+	calldata->arg.share_access =
+		nfs4_map_atomic_open_share(NFS_SERVER(inode),
+				calldata->arg.fmode, 0);
+
+	if (calldata->res.fattr == NULL)
+		calldata->arg.bitmask = NULL;
+	else if (calldata->arg.bitmask == NULL)
+		calldata->res.fattr = NULL;
+	calldata->timestamp = jiffies;
+	if (nfs4_setup_sequence(NFS_SERVER(inode)->nfs_client,
+				&calldata->arg.seq_args,
+				&calldata->res.seq_res,
+				task) != 0)
+		nfs_release_seqid(calldata->arg.seqid);
+	dprintk("%s: done!\n", __func__);
+	return;
+out_no_action:
+	task->tk_action = NULL;
+out_wait:
+	nfs4_sequence_done(task, &calldata->res.seq_res);
+}
+
+static const struct rpc_call_ops nfs4_close_ops = {
+	.rpc_call_prepare = nfs4_close_prepare,
+	.rpc_call_done = nfs4_close_done,
+	.rpc_release = nfs4_free_closedata,
+};
+
+/* 
+ * It is possible for data to be read/written from a mem-mapped file 
+ * after the sys_close call (which hits the vfs layer as a flush).
+ * This means that we can't safely call nfsv4 close on a file until 
+ * the inode is cleared. This in turn means that we are not good
+ * NFSv4 citizens - we do not indicate to the server to update the file's 
+ * share state even when we are done with one of the three share 
+ * stateid's in the inode.
+ *
+ * NOTE: Caller must be holding the sp->so_owner semaphore!
+ */
+int nfs4_do_close(struct nfs4_state *state, gfp_t gfp_mask, int wait)
+{
+	struct nfs_server *server = NFS_SERVER(state->inode);
+	struct nfs_seqid *(*alloc_seqid)(struct nfs_seqid_counter *, gfp_t);
+	struct nfs4_closedata *calldata;
+	struct nfs4_state_owner *sp = state->owner;
+	struct rpc_task *task;
+	struct rpc_message msg = {
+		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_CLOSE],
+		.rpc_cred = state->owner->so_cred,
+	};
+	struct rpc_task_setup task_setup_data = {
+		.rpc_client = server->client,
+		.rpc_message = &msg,
+		.callback_ops = &nfs4_close_ops,
+		.workqueue = nfsiod_workqueue,
+		.flags = RPC_TASK_ASYNC | RPC_TASK_CRED_NOREF,
+	};
+	int status = -ENOMEM;
+
+	nfs4_state_protect(server->nfs_client, NFS_SP4_MACH_CRED_CLEANUP,
+		&task_setup_data.rpc_client, &msg);
+
+	calldata = kzalloc(sizeof(*calldata), gfp_mask);
+	if (calldata == NULL)
+		goto out;
+	nfs4_init_sequence(&calldata->arg.seq_args, &calldata->res.seq_res, 1, 0);
+	calldata->inode = state->inode;
+	calldata->state = state;
+	calldata->arg.fh = NFS_FH(state->inode);
+	if (!nfs4_copy_open_stateid(&calldata->arg.stateid, state))
+		goto out_free_calldata;
+	/* Serialization for the sequence id */
+	alloc_seqid = server->nfs_client->cl_mvops->alloc_seqid;
+	calldata->arg.seqid = alloc_seqid(&state->owner->so_seqid, gfp_mask);
+	if (IS_ERR(calldata->arg.seqid))
+		goto out_free_calldata;
+	nfs_fattr_init(&calldata->fattr);
+	calldata->arg.fmode = 0;
+	calldata->lr.arg.ld_private = &calldata->lr.ld_private;
+	calldata->res.fattr = &calldata->fattr;
+	calldata->res.seqid = calldata->arg.seqid;
+	calldata->res.server = server;
+	calldata->res.lr_ret = -NFS4ERR_NOMATCHING_LAYOUT;
+	calldata->lr.roc = pnfs_roc(state->inode,
+			&calldata->lr.arg, &calldata->lr.res, msg.rpc_cred);
+	if (calldata->lr.roc) {
+		calldata->arg.lr_args = &calldata->lr.arg;
+		calldata->res.lr_res = &calldata->lr.res;
+	}
+	nfs_sb_active(calldata->inode->i_sb);
+
+	msg.rpc_argp = &calldata->arg;
+	msg.rpc_resp = &calldata->res;
+	task_setup_data.callback_data = calldata;
+	task = rpc_run_task(&task_setup_data);
+	if (IS_ERR(task))
+		return PTR_ERR(task);
+	status = 0;
+	if (wait)
+		status = rpc_wait_for_completion_task(task);
+	rpc_put_task(task);
+	return status;
+out_free_calldata:
+	kfree(calldata);
+out:
+	nfs4_put_open_state(state);
+	nfs4_put_state_owner(sp);
+	return status;
+}
+
+static struct inode *
+nfs4_atomic_open(struct inode *dir, struct nfs_open_context *ctx,
+		int open_flags, struct iattr *attr, int *opened)
+{
+	struct nfs4_state *state;
+	struct nfs4_label l, *label;
+
+	label = nfs4_label_init_security(dir, ctx->dentry, attr, &l);
+
+	/* Protect against concurrent sillydeletes */
+	state = nfs4_do_open(dir, ctx, open_flags, attr, label, opened);
+
+	nfs4_label_release_security(label);
+
+	if (IS_ERR(state))
+		return ERR_CAST(state);
+	return state->inode;
+}
+
+static void nfs4_close_context(struct nfs_open_context *ctx, int is_sync)
+{
+	if (ctx->state == NULL)
+		return;
+	if (is_sync)
+		nfs4_close_sync(ctx->state, _nfs4_ctx_to_openmode(ctx));
+	else
+		nfs4_close_state(ctx->state, _nfs4_ctx_to_openmode(ctx));
+}
+
+#define FATTR4_WORD1_NFS40_MASK (2*FATTR4_WORD1_MOUNTED_ON_FILEID - 1UL)
+#define FATTR4_WORD2_NFS41_MASK (2*FATTR4_WORD2_SUPPATTR_EXCLCREAT - 1UL)
+#define FATTR4_WORD2_NFS42_MASK (2*FATTR4_WORD2_XATTR_SUPPORT - 1UL)
+
+static int _nfs4_server_capabilities(struct nfs_server *server, struct nfs_fh *fhandle)
+{
+	u32 bitmask[3] = {}, minorversion = server->nfs_client->cl_minorversion;
+	struct nfs4_server_caps_arg args = {
+		.fhandle = fhandle,
+		.bitmask = bitmask,
+	};
+	struct nfs4_server_caps_res res = {};
+	struct rpc_message msg = {
+		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_SERVER_CAPS],
+		.rpc_argp = &args,
+		.rpc_resp = &res,
+	};
+	int status;
+	int i;
+
+	bitmask[0] = FATTR4_WORD0_SUPPORTED_ATTRS |
+		     FATTR4_WORD0_FH_EXPIRE_TYPE |
+		     FATTR4_WORD0_LINK_SUPPORT |
+		     FATTR4_WORD0_SYMLINK_SUPPORT |
+		     FATTR4_WORD0_ACLSUPPORT;
+	if (minorversion)
+		bitmask[2] = FATTR4_WORD2_SUPPATTR_EXCLCREAT;
+
+	status = nfs4_call_sync(server->client, server, &msg, &args.seq_args, &res.seq_res, 0);
+	if (status == 0) {
+		/* Sanity check the server answers */
+		switch (minorversion) {
+		case 0:
+			res.attr_bitmask[1] &= FATTR4_WORD1_NFS40_MASK;
+			res.attr_bitmask[2] = 0;
+			break;
+		case 1:
+			res.attr_bitmask[2] &= FATTR4_WORD2_NFS41_MASK;
+			break;
+		case 2:
+			res.attr_bitmask[2] &= FATTR4_WORD2_NFS42_MASK;
+		}
+		memcpy(server->attr_bitmask, res.attr_bitmask, sizeof(server->attr_bitmask));
+		server->caps &= ~(NFS_CAP_ACLS|NFS_CAP_HARDLINKS|
+				NFS_CAP_SYMLINKS|NFS_CAP_FILEID|
+				NFS_CAP_MODE|NFS_CAP_NLINK|NFS_CAP_OWNER|
+				NFS_CAP_OWNER_GROUP|NFS_CAP_ATIME|
+				NFS_CAP_CTIME|NFS_CAP_MTIME|
+				NFS_CAP_SECURITY_LABEL);
+		if (res.attr_bitmask[0] & FATTR4_WORD0_ACL &&
+				res.acl_bitmask & ACL4_SUPPORT_ALLOW_ACL)
+			server->caps |= NFS_CAP_ACLS;
+		if (res.has_links != 0)
+			server->caps |= NFS_CAP_HARDLINKS;
+		if (res.has_symlinks != 0)
+			server->caps |= NFS_CAP_SYMLINKS;
+		if (res.attr_bitmask[0] & FATTR4_WORD0_FILEID)
+			server->caps |= NFS_CAP_FILEID;
+		if (res.attr_bitmask[1] & FATTR4_WORD1_MODE)
+			server->caps |= NFS_CAP_MODE;
+		if (res.attr_bitmask[1] & FATTR4_WORD1_NUMLINKS)
+			server->caps |= NFS_CAP_NLINK;
+		if (res.attr_bitmask[1] & FATTR4_WORD1_OWNER)
+			server->caps |= NFS_CAP_OWNER;
+		if (res.attr_bitmask[1] & FATTR4_WORD1_OWNER_GROUP)
+			server->caps |= NFS_CAP_OWNER_GROUP;
+		if (res.attr_bitmask[1] & FATTR4_WORD1_TIME_ACCESS)
+			server->caps |= NFS_CAP_ATIME;
+		if (res.attr_bitmask[1] & FATTR4_WORD1_TIME_METADATA)
+			server->caps |= NFS_CAP_CTIME;
+		if (res.attr_bitmask[1] & FATTR4_WORD1_TIME_MODIFY)
+			server->caps |= NFS_CAP_MTIME;
+#ifdef CONFIG_NFS_V4_SECURITY_LABEL
+		if (res.attr_bitmask[2] & FATTR4_WORD2_SECURITY_LABEL)
+			server->caps |= NFS_CAP_SECURITY_LABEL;
+#endif
+		memcpy(server->attr_bitmask_nl, res.attr_bitmask,
+				sizeof(server->attr_bitmask));
+		server->attr_bitmask_nl[2] &= ~FATTR4_WORD2_SECURITY_LABEL;
+
+		memcpy(server->cache_consistency_bitmask, res.attr_bitmask, sizeof(server->cache_consistency_bitmask));
+		server->cache_consistency_bitmask[0] &= FATTR4_WORD0_CHANGE|FATTR4_WORD0_SIZE;
+		server->cache_consistency_bitmask[1] &= FATTR4_WORD1_TIME_METADATA|FATTR4_WORD1_TIME_MODIFY;
+		server->cache_consistency_bitmask[2] = 0;
+
+		/* Avoid a regression due to buggy server */
+		for (i = 0; i < ARRAY_SIZE(res.exclcreat_bitmask); i++)
+			res.exclcreat_bitmask[i] &= res.attr_bitmask[i];
+		memcpy(server->exclcreat_bitmask, res.exclcreat_bitmask,
+			sizeof(server->exclcreat_bitmask));
+
+		server->acl_bitmask = res.acl_bitmask;
+		server->fh_expire_type = res.fh_expire_type;
+	}
+
+	return status;
+}
+
+int nfs4_server_capabilities(struct nfs_server *server, struct nfs_fh *fhandle)
+{
+	struct nfs4_exception exception = {
+		.interruptible = true,
+	};
+	int err;
+	do {
+		err = nfs4_handle_exception(server,
+				_nfs4_server_capabilities(server, fhandle),
+				&exception);
+	} while (exception.retry);
+	return err;
+}
+
+static int _nfs4_lookup_root(struct nfs_server *server, struct nfs_fh *fhandle,
+		struct nfs_fsinfo *info)
+{
+	u32 bitmask[3];
+	struct nfs4_lookup_root_arg args = {
+		.bitmask = bitmask,
+	};
+	struct nfs4_lookup_res res = {
+		.server = server,
+		.fattr = info->fattr,
+		.fh = fhandle,
+	};
+	struct rpc_message msg = {
+		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_LOOKUP_ROOT],
+		.rpc_argp = &args,
+		.rpc_resp = &res,
+	};
+
+	bitmask[0] = nfs4_fattr_bitmap[0];
+	bitmask[1] = nfs4_fattr_bitmap[1];
+	/*
+	 * Process the label in the upcoming getfattr
+	 */
+	bitmask[2] = nfs4_fattr_bitmap[2] & ~FATTR4_WORD2_SECURITY_LABEL;
+
+	nfs_fattr_init(info->fattr);
+	return nfs4_call_sync(server->client, server, &msg, &args.seq_args, &res.seq_res, 0);
+}
+
+static int nfs4_lookup_root(struct nfs_server *server, struct nfs_fh *fhandle,
+		struct nfs_fsinfo *info)
+{
+	struct nfs4_exception exception = {
+		.interruptible = true,
+	};
+	int err;
+	do {
+		err = _nfs4_lookup_root(server, fhandle, info);
+		trace_nfs4_lookup_root(server, fhandle, info->fattr, err);
+		switch (err) {
+		case 0:
+		case -NFS4ERR_WRONGSEC:
+			goto out;
+		default:
+			err = nfs4_handle_exception(server, err, &exception);
+		}
+	} while (exception.retry);
+out:
+	return err;
+}
+
+static int nfs4_lookup_root_sec(struct nfs_server *server, struct nfs_fh *fhandle,
+				struct nfs_fsinfo *info, rpc_authflavor_t flavor)
+{
+	struct rpc_auth_create_args auth_args = {
+		.pseudoflavor = flavor,
+	};
+	struct rpc_auth *auth;
+
+	auth = rpcauth_create(&auth_args, server->client);
+	if (IS_ERR(auth))
+		return -EACCES;
+	return nfs4_lookup_root(server, fhandle, info);
+}
+
+/*
+ * Retry pseudoroot lookup with various security flavors.  We do this when:
+ *
+ *   NFSv4.0: the PUTROOTFH operation returns NFS4ERR_WRONGSEC
+ *   NFSv4.1: the server does not support the SECINFO_NO_NAME operation
+ *
+ * Returns zero on success, or a negative NFS4ERR value, or a
+ * negative errno value.
+ */
+static int nfs4_find_root_sec(struct nfs_server *server, struct nfs_fh *fhandle,
+			      struct nfs_fsinfo *info)
+{
+	/* Per 3530bis 15.33.5 */
+	static const rpc_authflavor_t flav_array[] = {
+		RPC_AUTH_GSS_KRB5P,
+		RPC_AUTH_GSS_KRB5I,
+		RPC_AUTH_GSS_KRB5,
+		RPC_AUTH_UNIX,			/* courtesy */
+		RPC_AUTH_NULL,
+	};
+	int status = -EPERM;
+	size_t i;
+
+	if (server->auth_info.flavor_len > 0) {
+		/* try each flavor specified by user */
+		for (i = 0; i < server->auth_info.flavor_len; i++) {
+			status = nfs4_lookup_root_sec(server, fhandle, info,
+						server->auth_info.flavors[i]);
+			if (status == -NFS4ERR_WRONGSEC || status == -EACCES)
+				continue;
+			break;
+		}
+	} else {
+		/* no flavors specified by user, try default list */
+		for (i = 0; i < ARRAY_SIZE(flav_array); i++) {
+			status = nfs4_lookup_root_sec(server, fhandle, info,
+						      flav_array[i]);
+			if (status == -NFS4ERR_WRONGSEC || status == -EACCES)
+				continue;
+			break;
+		}
+	}
+
+	/*
+	 * -EACCES could mean that the user doesn't have correct permissions
+	 * to access the mount.  It could also mean that we tried to mount
+	 * with a gss auth flavor, but rpc.gssd isn't running.  Either way,
+	 * existing mount programs don't handle -EACCES very well so it should
+	 * be mapped to -EPERM instead.
+	 */
+	if (status == -EACCES)
+		status = -EPERM;
+	return status;
+}
+
+/**
+ * nfs4_proc_get_rootfh - get file handle for server's pseudoroot
+ * @server: initialized nfs_server handle
+ * @fhandle: we fill in the pseudo-fs root file handle
+ * @info: we fill in an FSINFO struct
+ * @auth_probe: probe the auth flavours
+ *
+ * Returns zero on success, or a negative errno.
+ */
+int nfs4_proc_get_rootfh(struct nfs_server *server, struct nfs_fh *fhandle,
+			 struct nfs_fsinfo *info,
+			 bool auth_probe)
+{
+	int status = 0;
+
+	if (!auth_probe)
+		status = nfs4_lookup_root(server, fhandle, info);
+
+	if (auth_probe || status == NFS4ERR_WRONGSEC)
+		status = server->nfs_client->cl_mvops->find_root_sec(server,
+				fhandle, info);
+
+	if (status == 0)
+		status = nfs4_server_capabilities(server, fhandle);
+	if (status == 0)
+		status = nfs4_do_fsinfo(server, fhandle, info);
+
+	return nfs4_map_errors(status);
+}
+
+static int nfs4_proc_get_root(struct nfs_server *server, struct nfs_fh *mntfh,
+			      struct nfs_fsinfo *info)
+{
+	int error;
+	struct nfs_fattr *fattr = info->fattr;
+	struct nfs4_label *label = fattr->label;
+
+	error = nfs4_server_capabilities(server, mntfh);
+	if (error < 0) {
+		dprintk("nfs4_get_root: getcaps error = %d\n", -error);
+		return error;
+	}
+
+	error = nfs4_proc_getattr(server, mntfh, fattr, label, NULL);
+	if (error < 0) {
+		dprintk("nfs4_get_root: getattr error = %d\n", -error);
+		goto out;
+	}
+
+	if (fattr->valid & NFS_ATTR_FATTR_FSID &&
+	    !nfs_fsid_equal(&server->fsid, &fattr->fsid))
+		memcpy(&server->fsid, &fattr->fsid, sizeof(server->fsid));
+
+out:
+	return error;
+}
+
+/*
+ * Get locations and (maybe) other attributes of a referral.
+ * Note that we'll actually follow the referral later when
+ * we detect fsid mismatch in inode revalidation
+ */
+static int nfs4_get_referral(struct rpc_clnt *client, struct inode *dir,
+			     const struct qstr *name, struct nfs_fattr *fattr,
+			     struct nfs_fh *fhandle)
+{
+	int status = -ENOMEM;
+	struct page *page = NULL;
+	struct nfs4_fs_locations *locations = NULL;
+
+	page = alloc_page(GFP_KERNEL);
+	if (page == NULL)
+		goto out;
+	locations = kmalloc(sizeof(struct nfs4_fs_locations), GFP_KERNEL);
+	if (locations == NULL)
+		goto out;
+
+	status = nfs4_proc_fs_locations(client, dir, name, locations, page);
+	if (status != 0)
+		goto out;
+
+	/*
+	 * If the fsid didn't change, this is a migration event, not a
+	 * referral.  Cause us to drop into the exception handler, which
+	 * will kick off migration recovery.
+	 */
+	if (nfs_fsid_equal(&NFS_SERVER(dir)->fsid, &locations->fattr.fsid)) {
+		dprintk("%s: server did not return a different fsid for"
+			" a referral at %s\n", __func__, name->name);
+		status = -NFS4ERR_MOVED;
+		goto out;
+	}
+	/* Fixup attributes for the nfs_lookup() call to nfs_fhget() */
+	nfs_fixup_referral_attributes(&locations->fattr);
+
+	/* replace the lookup nfs_fattr with the locations nfs_fattr */
+	memcpy(fattr, &locations->fattr, sizeof(struct nfs_fattr));
+	memset(fhandle, 0, sizeof(struct nfs_fh));
+out:
+	if (page)
+		__free_page(page);
+	kfree(locations);
+	return status;
+}
+
+static int _nfs4_proc_getattr(struct nfs_server *server, struct nfs_fh *fhandle,
+				struct nfs_fattr *fattr, struct nfs4_label *label,
+				struct inode *inode)
+{
+	__u32 bitmask[NFS4_BITMASK_SZ];
+	struct nfs4_getattr_arg args = {
+		.fh = fhandle,
+		.bitmask = bitmask,
+	};
+	struct nfs4_getattr_res res = {
+		.fattr = fattr,
+		.label = label,
+		.server = server,
+	};
+	struct rpc_message msg = {
+		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_GETATTR],
+		.rpc_argp = &args,
+		.rpc_resp = &res,
+	};
+	unsigned short task_flags = 0;
+
+	/* Is this is an attribute revalidation, subject to softreval? */
+	if (inode && (server->flags & NFS_MOUNT_SOFTREVAL))
+		task_flags |= RPC_TASK_TIMEOUT;
+
+	nfs4_bitmap_copy_adjust(bitmask, nfs4_bitmask(server, label), inode);
+
+	nfs_fattr_init(fattr);
+	nfs4_init_sequence(&args.seq_args, &res.seq_res, 0, 0);
+	return nfs4_do_call_sync(server->client, server, &msg,
+			&args.seq_args, &res.seq_res, task_flags);
+}
+
+int nfs4_proc_getattr(struct nfs_server *server, struct nfs_fh *fhandle,
+				struct nfs_fattr *fattr, struct nfs4_label *label,
+				struct inode *inode)
+{
+	struct nfs4_exception exception = {
+		.interruptible = true,
+	};
+	int err;
+	do {
+		err = _nfs4_proc_getattr(server, fhandle, fattr, label, inode);
+		trace_nfs4_getattr(server, fhandle, fattr, err);
+		err = nfs4_handle_exception(server, err,
+				&exception);
+	} while (exception.retry);
+	return err;
+}
+
+/* 
+ * The file is not closed if it is opened due to the a request to change
+ * the size of the file. The open call will not be needed once the
+ * VFS layer lookup-intents are implemented.
+ *
+ * Close is called when the inode is destroyed.
+ * If we haven't opened the file for O_WRONLY, we
+ * need to in the size_change case to obtain a stateid.
+ *
+ * Got race?
+ * Because OPEN is always done by name in nfsv4, it is
+ * possible that we opened a different file by the same
+ * name.  We can recognize this race condition, but we
+ * can't do anything about it besides returning an error.
+ *
+ * This will be fixed with VFS changes (lookup-intent).
+ */
+static int
+nfs4_proc_setattr(struct dentry *dentry, struct nfs_fattr *fattr,
+		  struct iattr *sattr)
+{
+	struct inode *inode = d_inode(dentry);
+	const struct cred *cred = NULL;
+	struct nfs_open_context *ctx = NULL;
+	struct nfs4_label *label = NULL;
+	int status;
+
+	if (pnfs_ld_layoutret_on_setattr(inode) &&
+	    sattr->ia_valid & ATTR_SIZE &&
+	    sattr->ia_size < i_size_read(inode))
+		pnfs_commit_and_return_layout(inode);
+
+	nfs_fattr_init(fattr);
+	
+	/* Deal with open(O_TRUNC) */
+	if (sattr->ia_valid & ATTR_OPEN)
+		sattr->ia_valid &= ~(ATTR_MTIME|ATTR_CTIME);
+
+	/* Optimization: if the end result is no change, don't RPC */
+	if ((sattr->ia_valid & ~(ATTR_FILE|ATTR_OPEN)) == 0)
+		return 0;
+
+	/* Search for an existing open(O_WRITE) file */
+	if (sattr->ia_valid & ATTR_FILE) {
+
+		ctx = nfs_file_open_context(sattr->ia_file);
+		if (ctx)
+			cred = ctx->cred;
+	}
+
+	label = nfs4_label_alloc(NFS_SERVER(inode), GFP_KERNEL);
+	if (IS_ERR(label))
+		return PTR_ERR(label);
+
+	/* Return any delegations if we're going to change ACLs */
+	if ((sattr->ia_valid & (ATTR_MODE|ATTR_UID|ATTR_GID)) != 0)
+		nfs4_inode_make_writeable(inode);
+
+	status = nfs4_do_setattr(inode, cred, fattr, sattr, ctx, NULL, label);
+	if (status == 0) {
+		nfs_setattr_update_inode(inode, sattr, fattr);
+		nfs_setsecurity(inode, fattr, label);
+	}
+	nfs4_label_free(label);
+	return status;
+}
+
+static int _nfs4_proc_lookup(struct rpc_clnt *clnt, struct inode *dir,
+		struct dentry *dentry, struct nfs_fh *fhandle,
+		struct nfs_fattr *fattr, struct nfs4_label *label)
+{
+	struct nfs_server *server = NFS_SERVER(dir);
+	int		       status;
+	struct nfs4_lookup_arg args = {
+		.bitmask = server->attr_bitmask,
+		.dir_fh = NFS_FH(dir),
+		.name = &dentry->d_name,
+	};
+	struct nfs4_lookup_res res = {
+		.server = server,
+		.fattr = fattr,
+		.label = label,
+		.fh = fhandle,
+	};
+	struct rpc_message msg = {
+		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_LOOKUP],
+		.rpc_argp = &args,
+		.rpc_resp = &res,
+	};
+	unsigned short task_flags = 0;
+
+	/* Is this is an attribute revalidation, subject to softreval? */
+	if (nfs_lookup_is_soft_revalidate(dentry))
+		task_flags |= RPC_TASK_TIMEOUT;
+
+	args.bitmask = nfs4_bitmask(server, label);
+
+	nfs_fattr_init(fattr);
+
+	dprintk("NFS call  lookup %pd2\n", dentry);
+	nfs4_init_sequence(&args.seq_args, &res.seq_res, 0, 0);
+	status = nfs4_do_call_sync(clnt, server, &msg,
+			&args.seq_args, &res.seq_res, task_flags);
+	dprintk("NFS reply lookup: %d\n", status);
+	return status;
+}
+
+static void nfs_fixup_secinfo_attributes(struct nfs_fattr *fattr)
+{
+	fattr->valid |= NFS_ATTR_FATTR_TYPE | NFS_ATTR_FATTR_MODE |
+		NFS_ATTR_FATTR_NLINK | NFS_ATTR_FATTR_MOUNTPOINT;
+	fattr->mode = S_IFDIR | S_IRUGO | S_IXUGO;
+	fattr->nlink = 2;
+}
+
+static int nfs4_proc_lookup_common(struct rpc_clnt **clnt, struct inode *dir,
+				   struct dentry *dentry, struct nfs_fh *fhandle,
+				   struct nfs_fattr *fattr, struct nfs4_label *label)
+{
+	struct nfs4_exception exception = {
+		.interruptible = true,
+	};
+	struct rpc_clnt *client = *clnt;
+	const struct qstr *name = &dentry->d_name;
+	int err;
+	do {
+		err = _nfs4_proc_lookup(client, dir, dentry, fhandle, fattr, label);
+		trace_nfs4_lookup(dir, name, err);
+		switch (err) {
+		case -NFS4ERR_BADNAME:
+			err = -ENOENT;
+			goto out;
+		case -NFS4ERR_MOVED:
+			err = nfs4_get_referral(client, dir, name, fattr, fhandle);
+			if (err == -NFS4ERR_MOVED)
+				err = nfs4_handle_exception(NFS_SERVER(dir), err, &exception);
+			goto out;
+		case -NFS4ERR_WRONGSEC:
+			err = -EPERM;
+			if (client != *clnt)
+				goto out;
+			client = nfs4_negotiate_security(client, dir, name);
+			if (IS_ERR(client))
+				return PTR_ERR(client);
+
+			exception.retry = 1;
+			break;
+		default:
+			err = nfs4_handle_exception(NFS_SERVER(dir), err, &exception);
+		}
+	} while (exception.retry);
+
+out:
+	if (err == 0)
+		*clnt = client;
+	else if (client != *clnt)
+		rpc_shutdown_client(client);
+
+	return err;
+}
+
+static int nfs4_proc_lookup(struct inode *dir, struct dentry *dentry,
+			    struct nfs_fh *fhandle, struct nfs_fattr *fattr,
+			    struct nfs4_label *label)
+{
+	int status;
+	struct rpc_clnt *client = NFS_CLIENT(dir);
+
+	status = nfs4_proc_lookup_common(&client, dir, dentry, fhandle, fattr, label);
+	if (client != NFS_CLIENT(dir)) {
+		rpc_shutdown_client(client);
+		nfs_fixup_secinfo_attributes(fattr);
+	}
+	return status;
+}
+
+struct rpc_clnt *
+nfs4_proc_lookup_mountpoint(struct inode *dir, struct dentry *dentry,
+			    struct nfs_fh *fhandle, struct nfs_fattr *fattr)
+{
+	struct rpc_clnt *client = NFS_CLIENT(dir);
+	int status;
+
+	status = nfs4_proc_lookup_common(&client, dir, dentry, fhandle, fattr, NULL);
+	if (status < 0)
+		return ERR_PTR(status);
+	return (client == NFS_CLIENT(dir)) ? rpc_clone_client(client) : client;
+}
+
+static int _nfs4_proc_lookupp(struct inode *inode,
+		struct nfs_fh *fhandle, struct nfs_fattr *fattr,
+		struct nfs4_label *label)
+{
+	struct rpc_clnt *clnt = NFS_CLIENT(inode);
+	struct nfs_server *server = NFS_SERVER(inode);
+	int		       status;
+	struct nfs4_lookupp_arg args = {
+		.bitmask = server->attr_bitmask,
+		.fh = NFS_FH(inode),
+	};
+	struct nfs4_lookupp_res res = {
+		.server = server,
+		.fattr = fattr,
+		.label = label,
+		.fh = fhandle,
+	};
+	struct rpc_message msg = {
+		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_LOOKUPP],
+		.rpc_argp = &args,
+		.rpc_resp = &res,
+	};
+
+	args.bitmask = nfs4_bitmask(server, label);
+
+	nfs_fattr_init(fattr);
+
+	dprintk("NFS call  lookupp ino=0x%lx\n", inode->i_ino);
+	status = nfs4_call_sync(clnt, server, &msg, &args.seq_args,
+				&res.seq_res, 0);
+	dprintk("NFS reply lookupp: %d\n", status);
+	return status;
+}
+
+static int nfs4_proc_lookupp(struct inode *inode, struct nfs_fh *fhandle,
+			     struct nfs_fattr *fattr, struct nfs4_label *label)
+{
+	struct nfs4_exception exception = {
+		.interruptible = true,
+	};
+	int err;
+	do {
+		err = _nfs4_proc_lookupp(inode, fhandle, fattr, label);
+		trace_nfs4_lookupp(inode, err);
+		err = nfs4_handle_exception(NFS_SERVER(inode), err,
+				&exception);
+	} while (exception.retry);
+	return err;
+}
+
+static int _nfs4_proc_access(struct inode *inode, struct nfs_access_entry *entry)
+{
+	struct nfs_server *server = NFS_SERVER(inode);
+	struct nfs4_accessargs args = {
+		.fh = NFS_FH(inode),
+		.access = entry->mask,
+	};
+	struct nfs4_accessres res = {
+		.server = server,
+	};
+	struct rpc_message msg = {
+		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_ACCESS],
+		.rpc_argp = &args,
+		.rpc_resp = &res,
+		.rpc_cred = entry->cred,
+	};
+	int status = 0;
+
+	if (!nfs4_have_delegation(inode, FMODE_READ)) {
+		res.fattr = nfs_alloc_fattr();
+		if (res.fattr == NULL)
+			return -ENOMEM;
+		args.bitmask = server->cache_consistency_bitmask;
+	}
+	status = nfs4_call_sync(server->client, server, &msg, &args.seq_args, &res.seq_res, 0);
+	if (!status) {
+		nfs_access_set_mask(entry, res.access);
+		if (res.fattr)
+			nfs_refresh_inode(inode, res.fattr);
+	}
+	nfs_free_fattr(res.fattr);
+	return status;
+}
+
+static int nfs4_proc_access(struct inode *inode, struct nfs_access_entry *entry)
+{
+	struct nfs4_exception exception = {
+		.interruptible = true,
+	};
+	int err;
+	do {
+		err = _nfs4_proc_access(inode, entry);
+		trace_nfs4_access(inode, err);
+		err = nfs4_handle_exception(NFS_SERVER(inode), err,
+				&exception);
+	} while (exception.retry);
+	return err;
+}
+
+/*
+ * TODO: For the time being, we don't try to get any attributes
+ * along with any of the zero-copy operations READ, READDIR,
+ * READLINK, WRITE.
+ *
+ * In the case of the first three, we want to put the GETATTR
+ * after the read-type operation -- this is because it is hard
+ * to predict the length of a GETATTR response in v4, and thus
+ * align the READ data correctly.  This means that the GETATTR
+ * may end up partially falling into the page cache, and we should
+ * shift it into the 'tail' of the xdr_buf before processing.
+ * To do this efficiently, we need to know the total length
+ * of data received, which doesn't seem to be available outside
+ * of the RPC layer.
+ *
+ * In the case of WRITE, we also want to put the GETATTR after
+ * the operation -- in this case because we want to make sure
+ * we get the post-operation mtime and size.
+ *
+ * Both of these changes to the XDR layer would in fact be quite
+ * minor, but I decided to leave them for a subsequent patch.
+ */
+static int _nfs4_proc_readlink(struct inode *inode, struct page *page,
+		unsigned int pgbase, unsigned int pglen)
+{
+	struct nfs4_readlink args = {
+		.fh       = NFS_FH(inode),
+		.pgbase	  = pgbase,
+		.pglen    = pglen,
+		.pages    = &page,
+	};
+	struct nfs4_readlink_res res;
+	struct rpc_message msg = {
+		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_READLINK],
+		.rpc_argp = &args,
+		.rpc_resp = &res,
+	};
+
+	return nfs4_call_sync(NFS_SERVER(inode)->client, NFS_SERVER(inode), &msg, &args.seq_args, &res.seq_res, 0);
+}
+
+static int nfs4_proc_readlink(struct inode *inode, struct page *page,
+		unsigned int pgbase, unsigned int pglen)
+{
+	struct nfs4_exception exception = {
+		.interruptible = true,
+	};
+	int err;
+	do {
+		err = _nfs4_proc_readlink(inode, page, pgbase, pglen);
+		trace_nfs4_readlink(inode, err);
+		err = nfs4_handle_exception(NFS_SERVER(inode), err,
+				&exception);
+	} while (exception.retry);
+	return err;
+}
+
+/*
+ * This is just for mknod.  open(O_CREAT) will always do ->open_context().
+ */
+static int
+nfs4_proc_create(struct inode *dir, struct dentry *dentry, struct iattr *sattr,
+		 int flags)
+{
+	struct nfs_server *server = NFS_SERVER(dir);
+	struct nfs4_label l, *ilabel;
+	struct nfs_open_context *ctx;
+	struct nfs4_state *state;
+	int status = 0;
+
+	ctx = alloc_nfs_open_context(dentry, FMODE_READ, NULL);
+	if (IS_ERR(ctx))
+		return PTR_ERR(ctx);
+
+	ilabel = nfs4_label_init_security(dir, dentry, sattr, &l);
+
+	if (!(server->attr_bitmask[2] & FATTR4_WORD2_MODE_UMASK))
+		sattr->ia_mode &= ~current_umask();
+	state = nfs4_do_open(dir, ctx, flags, sattr, ilabel, NULL);
+	if (IS_ERR(state)) {
+		status = PTR_ERR(state);
+		goto out;
+	}
+out:
+	nfs4_label_release_security(ilabel);
+	put_nfs_open_context(ctx);
+	return status;
+}
+
+static int
+_nfs4_proc_remove(struct inode *dir, const struct qstr *name, u32 ftype)
+{
+	struct nfs_server *server = NFS_SERVER(dir);
+	struct nfs_removeargs args = {
+		.fh = NFS_FH(dir),
+		.name = *name,
+	};
+	struct nfs_removeres res = {
+		.server = server,
+	};
+	struct rpc_message msg = {
+		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_REMOVE],
+		.rpc_argp = &args,
+		.rpc_resp = &res,
+	};
+	unsigned long timestamp = jiffies;
+	int status;
+
+	status = nfs4_call_sync(server->client, server, &msg, &args.seq_args, &res.seq_res, 1);
+	if (status == 0) {
+		spin_lock(&dir->i_lock);
+		nfs4_update_changeattr_locked(dir, &res.cinfo, timestamp,
+					      NFS_INO_INVALID_DATA);
+		/* Removing a directory decrements nlink in the parent */
+		if (ftype == NF4DIR && dir->i_nlink > 2)
+			nfs4_dec_nlink_locked(dir);
+		spin_unlock(&dir->i_lock);
+	}
+	return status;
+}
+
+static int nfs4_proc_remove(struct inode *dir, struct dentry *dentry)
+{
+	struct nfs4_exception exception = {
+		.interruptible = true,
+	};
+	struct inode *inode = d_inode(dentry);
+	int err;
+
+	if (inode) {
+		if (inode->i_nlink == 1)
+			nfs4_inode_return_delegation(inode);
+		else
+			nfs4_inode_make_writeable(inode);
+	}
+	do {
+		err = _nfs4_proc_remove(dir, &dentry->d_name, NF4REG);
+		trace_nfs4_remove(dir, &dentry->d_name, err);
+		err = nfs4_handle_exception(NFS_SERVER(dir), err,
+				&exception);
+	} while (exception.retry);
+	return err;
+}
+
+static int nfs4_proc_rmdir(struct inode *dir, const struct qstr *name)
+{
+	struct nfs4_exception exception = {
+		.interruptible = true,
+	};
+	int err;
+
+	do {
+		err = _nfs4_proc_remove(dir, name, NF4DIR);
+		trace_nfs4_remove(dir, name, err);
+		err = nfs4_handle_exception(NFS_SERVER(dir), err,
+				&exception);
+	} while (exception.retry);
+	return err;
+}
+
+static void nfs4_proc_unlink_setup(struct rpc_message *msg,
+		struct dentry *dentry,
+		struct inode *inode)
+{
+	struct nfs_removeargs *args = msg->rpc_argp;
+	struct nfs_removeres *res = msg->rpc_resp;
+
+	res->server = NFS_SB(dentry->d_sb);
+	msg->rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_REMOVE];
+	nfs4_init_sequence(&args->seq_args, &res->seq_res, 1, 0);
+
+	nfs_fattr_init(res->dir_attr);
+
+	if (inode)
+		nfs4_inode_return_delegation(inode);
+}
+
+static void nfs4_proc_unlink_rpc_prepare(struct rpc_task *task, struct nfs_unlinkdata *data)
+{
+	nfs4_setup_sequence(NFS_SB(data->dentry->d_sb)->nfs_client,
+			&data->args.seq_args,
+			&data->res.seq_res,
+			task);
+}
+
+static int nfs4_proc_unlink_done(struct rpc_task *task, struct inode *dir)
+{
+	struct nfs_unlinkdata *data = task->tk_calldata;
+	struct nfs_removeres *res = &data->res;
+
+	if (!nfs4_sequence_done(task, &res->seq_res))
+		return 0;
+	if (nfs4_async_handle_error(task, res->server, NULL,
+				    &data->timeout) == -EAGAIN)
+		return 0;
+	if (task->tk_status == 0)
+		nfs4_update_changeattr(dir, &res->cinfo,
+				res->dir_attr->time_start,
+				NFS_INO_INVALID_DATA);
+	return 1;
+}
+
+static void nfs4_proc_rename_setup(struct rpc_message *msg,
+		struct dentry *old_dentry,
+		struct dentry *new_dentry)
+{
+	struct nfs_renameargs *arg = msg->rpc_argp;
+	struct nfs_renameres *res = msg->rpc_resp;
+	struct inode *old_inode = d_inode(old_dentry);
+	struct inode *new_inode = d_inode(new_dentry);
+
+	if (old_inode)
+		nfs4_inode_make_writeable(old_inode);
+	if (new_inode)
+		nfs4_inode_return_delegation(new_inode);
+	msg->rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_RENAME];
+	res->server = NFS_SB(old_dentry->d_sb);
+	nfs4_init_sequence(&arg->seq_args, &res->seq_res, 1, 0);
+}
+
+static void nfs4_proc_rename_rpc_prepare(struct rpc_task *task, struct nfs_renamedata *data)
+{
+	nfs4_setup_sequence(NFS_SERVER(data->old_dir)->nfs_client,
+			&data->args.seq_args,
+			&data->res.seq_res,
+			task);
+}
+
+static int nfs4_proc_rename_done(struct rpc_task *task, struct inode *old_dir,
+				 struct inode *new_dir)
+{
+	struct nfs_renamedata *data = task->tk_calldata;
+	struct nfs_renameres *res = &data->res;
+
+	if (!nfs4_sequence_done(task, &res->seq_res))
+		return 0;
+	if (nfs4_async_handle_error(task, res->server, NULL, &data->timeout) == -EAGAIN)
+		return 0;
+
+	if (task->tk_status == 0) {
+		if (new_dir != old_dir) {
+			/* Note: If we moved a directory, nlink will change */
+			nfs4_update_changeattr(old_dir, &res->old_cinfo,
+					res->old_fattr->time_start,
+					NFS_INO_INVALID_OTHER |
+					    NFS_INO_INVALID_DATA);
+			nfs4_update_changeattr(new_dir, &res->new_cinfo,
+					res->new_fattr->time_start,
+					NFS_INO_INVALID_OTHER |
+					    NFS_INO_INVALID_DATA);
+		} else
+			nfs4_update_changeattr(old_dir, &res->old_cinfo,
+					res->old_fattr->time_start,
+					NFS_INO_INVALID_DATA);
+	}
+	return 1;
+}
+
+static int _nfs4_proc_link(struct inode *inode, struct inode *dir, const struct qstr *name)
+{
+	struct nfs_server *server = NFS_SERVER(inode);
+	__u32 bitmask[NFS4_BITMASK_SZ];
+	struct nfs4_link_arg arg = {
+		.fh     = NFS_FH(inode),
+		.dir_fh = NFS_FH(dir),
+		.name   = name,
+		.bitmask = bitmask,
+	};
+	struct nfs4_link_res res = {
+		.server = server,
+		.label = NULL,
+	};
+	struct rpc_message msg = {
+		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_LINK],
+		.rpc_argp = &arg,
+		.rpc_resp = &res,
+	};
+	int status = -ENOMEM;
+
+	res.fattr = nfs_alloc_fattr();
+	if (res.fattr == NULL)
+		goto out;
+
+	res.label = nfs4_label_alloc(server, GFP_KERNEL);
+	if (IS_ERR(res.label)) {
+		status = PTR_ERR(res.label);
+		goto out;
+	}
+
+	nfs4_inode_make_writeable(inode);
+	nfs4_bitmap_copy_adjust_setattr(bitmask, nfs4_bitmask(server, res.label), inode);
+
+	status = nfs4_call_sync(server->client, server, &msg, &arg.seq_args, &res.seq_res, 1);
+	if (!status) {
+		nfs4_update_changeattr(dir, &res.cinfo, res.fattr->time_start,
+				       NFS_INO_INVALID_DATA);
+		status = nfs_post_op_update_inode(inode, res.fattr);
+		if (!status)
+			nfs_setsecurity(inode, res.fattr, res.label);
+	}
+
+
+	nfs4_label_free(res.label);
+
+out:
+	nfs_free_fattr(res.fattr);
+	return status;
+}
+
+static int nfs4_proc_link(struct inode *inode, struct inode *dir, const struct qstr *name)
+{
+	struct nfs4_exception exception = {
+		.interruptible = true,
+	};
+	int err;
+	do {
+		err = nfs4_handle_exception(NFS_SERVER(inode),
+				_nfs4_proc_link(inode, dir, name),
+				&exception);
+	} while (exception.retry);
+	return err;
+}
+
+struct nfs4_createdata {
+	struct rpc_message msg;
+	struct nfs4_create_arg arg;
+	struct nfs4_create_res res;
+	struct nfs_fh fh;
+	struct nfs_fattr fattr;
+	struct nfs4_label *label;
+};
+
+static struct nfs4_createdata *nfs4_alloc_createdata(struct inode *dir,
+		const struct qstr *name, struct iattr *sattr, u32 ftype)
+{
+	struct nfs4_createdata *data;
+
+	data = kzalloc(sizeof(*data), GFP_KERNEL);
+	if (data != NULL) {
+		struct nfs_server *server = NFS_SERVER(dir);
+
+		data->label = nfs4_label_alloc(server, GFP_KERNEL);
+		if (IS_ERR(data->label))
+			goto out_free;
+
+		data->msg.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_CREATE];
+		data->msg.rpc_argp = &data->arg;
+		data->msg.rpc_resp = &data->res;
+		data->arg.dir_fh = NFS_FH(dir);
+		data->arg.server = server;
+		data->arg.name = name;
+		data->arg.attrs = sattr;
+		data->arg.ftype = ftype;
+		data->arg.bitmask = nfs4_bitmask(server, data->label);
+		data->arg.umask = current_umask();
+		data->res.server = server;
+		data->res.fh = &data->fh;
+		data->res.fattr = &data->fattr;
+		data->res.label = data->label;
+		nfs_fattr_init(data->res.fattr);
+	}
+	return data;
+out_free:
+	kfree(data);
+	return NULL;
+}
+
+static int nfs4_do_create(struct inode *dir, struct dentry *dentry, struct nfs4_createdata *data)
+{
+	int status = nfs4_call_sync(NFS_SERVER(dir)->client, NFS_SERVER(dir), &data->msg,
+				    &data->arg.seq_args, &data->res.seq_res, 1);
+	if (status == 0) {
+		spin_lock(&dir->i_lock);
+		nfs4_update_changeattr_locked(dir, &data->res.dir_cinfo,
+				data->res.fattr->time_start,
+				NFS_INO_INVALID_DATA);
+		/* Creating a directory bumps nlink in the parent */
+		if (data->arg.ftype == NF4DIR)
+			nfs4_inc_nlink_locked(dir);
+		spin_unlock(&dir->i_lock);
+		status = nfs_instantiate(dentry, data->res.fh, data->res.fattr, data->res.label);
+	}
+	return status;
+}
+
+static void nfs4_free_createdata(struct nfs4_createdata *data)
+{
+	nfs4_label_free(data->label);
+	kfree(data);
+}
+
+static int _nfs4_proc_symlink(struct inode *dir, struct dentry *dentry,
+		struct page *page, unsigned int len, struct iattr *sattr,
+		struct nfs4_label *label)
+{
+	struct nfs4_createdata *data;
+	int status = -ENAMETOOLONG;
+
+	if (len > NFS4_MAXPATHLEN)
+		goto out;
+
+	status = -ENOMEM;
+	data = nfs4_alloc_createdata(dir, &dentry->d_name, sattr, NF4LNK);
+	if (data == NULL)
+		goto out;
+
+	data->msg.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_SYMLINK];
+	data->arg.u.symlink.pages = &page;
+	data->arg.u.symlink.len = len;
+	data->arg.label = label;
+	
+	status = nfs4_do_create(dir, dentry, data);
+
+	nfs4_free_createdata(data);
+out:
+	return status;
+}
+
+static int nfs4_proc_symlink(struct inode *dir, struct dentry *dentry,
+		struct page *page, unsigned int len, struct iattr *sattr)
+{
+	struct nfs4_exception exception = {
+		.interruptible = true,
+	};
+	struct nfs4_label l, *label;
+	int err;
+
+	label = nfs4_label_init_security(dir, dentry, sattr, &l);
+
+	do {
+		err = _nfs4_proc_symlink(dir, dentry, page, len, sattr, label);
+		trace_nfs4_symlink(dir, &dentry->d_name, err);
+		err = nfs4_handle_exception(NFS_SERVER(dir), err,
+				&exception);
+	} while (exception.retry);
+
+	nfs4_label_release_security(label);
+	return err;
+}
+
+static int _nfs4_proc_mkdir(struct inode *dir, struct dentry *dentry,
+		struct iattr *sattr, struct nfs4_label *label)
+{
+	struct nfs4_createdata *data;
+	int status = -ENOMEM;
+
+	data = nfs4_alloc_createdata(dir, &dentry->d_name, sattr, NF4DIR);
+	if (data == NULL)
+		goto out;
+
+	data->arg.label = label;
+	status = nfs4_do_create(dir, dentry, data);
+
+	nfs4_free_createdata(data);
+out:
+	return status;
+}
+
+static int nfs4_proc_mkdir(struct inode *dir, struct dentry *dentry,
+		struct iattr *sattr)
+{
+	struct nfs_server *server = NFS_SERVER(dir);
+	struct nfs4_exception exception = {
+		.interruptible = true,
+	};
+	struct nfs4_label l, *label;
+	int err;
+
+	label = nfs4_label_init_security(dir, dentry, sattr, &l);
+
+	if (!(server->attr_bitmask[2] & FATTR4_WORD2_MODE_UMASK))
+		sattr->ia_mode &= ~current_umask();
+	do {
+		err = _nfs4_proc_mkdir(dir, dentry, sattr, label);
+		trace_nfs4_mkdir(dir, &dentry->d_name, err);
+		err = nfs4_handle_exception(NFS_SERVER(dir), err,
+				&exception);
+	} while (exception.retry);
+	nfs4_label_release_security(label);
+
+	return err;
+}
+
+static int _nfs4_proc_readdir(struct dentry *dentry, const struct cred *cred,
+		u64 cookie, struct page **pages, unsigned int count, bool plus)
+{
+	struct inode		*dir = d_inode(dentry);
+	struct nfs_server	*server = NFS_SERVER(dir);
+	struct nfs4_readdir_arg args = {
+		.fh = NFS_FH(dir),
+		.pages = pages,
+		.pgbase = 0,
+		.count = count,
+		.plus = plus,
+	};
+	struct nfs4_readdir_res res;
+	struct rpc_message msg = {
+		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_READDIR],
+		.rpc_argp = &args,
+		.rpc_resp = &res,
+		.rpc_cred = cred,
+	};
+	int			status;
+
+	dprintk("%s: dentry = %pd2, cookie = %Lu\n", __func__,
+			dentry,
+			(unsigned long long)cookie);
+	if (!(server->caps & NFS_CAP_SECURITY_LABEL))
+		args.bitmask = server->attr_bitmask_nl;
+	else
+		args.bitmask = server->attr_bitmask;
+
+	nfs4_setup_readdir(cookie, NFS_I(dir)->cookieverf, dentry, &args);
+	res.pgbase = args.pgbase;
+	status = nfs4_call_sync(server->client, server, &msg, &args.seq_args,
+			&res.seq_res, 0);
+	if (status >= 0) {
+		memcpy(NFS_I(dir)->cookieverf, res.verifier.data, NFS4_VERIFIER_SIZE);
+		status += args.pgbase;
+	}
+
+	nfs_invalidate_atime(dir);
+
+	dprintk("%s: returns %d\n", __func__, status);
+	return status;
+}
+
+static int nfs4_proc_readdir(struct dentry *dentry, const struct cred *cred,
+		u64 cookie, struct page **pages, unsigned int count, bool plus)
+{
+	struct nfs4_exception exception = {
+		.interruptible = true,
+	};
+	int err;
+	do {
+		err = _nfs4_proc_readdir(dentry, cred, cookie,
+				pages, count, plus);
+		trace_nfs4_readdir(d_inode(dentry), err);
+		err = nfs4_handle_exception(NFS_SERVER(d_inode(dentry)), err,
+				&exception);
+	} while (exception.retry);
+	return err;
+}
+
+static int _nfs4_proc_mknod(struct inode *dir, struct dentry *dentry,
+		struct iattr *sattr, struct nfs4_label *label, dev_t rdev)
+{
+	struct nfs4_createdata *data;
+	int mode = sattr->ia_mode;
+	int status = -ENOMEM;
+
+	data = nfs4_alloc_createdata(dir, &dentry->d_name, sattr, NF4SOCK);
+	if (data == NULL)
+		goto out;
+
+	if (S_ISFIFO(mode))
+		data->arg.ftype = NF4FIFO;
+	else if (S_ISBLK(mode)) {
+		data->arg.ftype = NF4BLK;
+		data->arg.u.device.specdata1 = MAJOR(rdev);
+		data->arg.u.device.specdata2 = MINOR(rdev);
+	}
+	else if (S_ISCHR(mode)) {
+		data->arg.ftype = NF4CHR;
+		data->arg.u.device.specdata1 = MAJOR(rdev);
+		data->arg.u.device.specdata2 = MINOR(rdev);
+	} else if (!S_ISSOCK(mode)) {
+		status = -EINVAL;
+		goto out_free;
+	}
+
+	data->arg.label = label;
+	status = nfs4_do_create(dir, dentry, data);
+out_free:
+	nfs4_free_createdata(data);
+out:
+	return status;
+}
+
+static int nfs4_proc_mknod(struct inode *dir, struct dentry *dentry,
+		struct iattr *sattr, dev_t rdev)
+{
+	struct nfs_server *server = NFS_SERVER(dir);
+	struct nfs4_exception exception = {
+		.interruptible = true,
+	};
+	struct nfs4_label l, *label;
+	int err;
+
+	label = nfs4_label_init_security(dir, dentry, sattr, &l);
+
+	if (!(server->attr_bitmask[2] & FATTR4_WORD2_MODE_UMASK))
+		sattr->ia_mode &= ~current_umask();
+	do {
+		err = _nfs4_proc_mknod(dir, dentry, sattr, label, rdev);
+		trace_nfs4_mknod(dir, &dentry->d_name, err);
+		err = nfs4_handle_exception(NFS_SERVER(dir), err,
+				&exception);
+	} while (exception.retry);
+
+	nfs4_label_release_security(label);
+
+	return err;
+}
+
+static int _nfs4_proc_statfs(struct nfs_server *server, struct nfs_fh *fhandle,
+		 struct nfs_fsstat *fsstat)
+{
+	struct nfs4_statfs_arg args = {
+		.fh = fhandle,
+		.bitmask = server->attr_bitmask,
+	};
+	struct nfs4_statfs_res res = {
+		.fsstat = fsstat,
+	};
+	struct rpc_message msg = {
+		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_STATFS],
+		.rpc_argp = &args,
+		.rpc_resp = &res,
+	};
+
+	nfs_fattr_init(fsstat->fattr);
+	return  nfs4_call_sync(server->client, server, &msg, &args.seq_args, &res.seq_res, 0);
+}
+
+static int nfs4_proc_statfs(struct nfs_server *server, struct nfs_fh *fhandle, struct nfs_fsstat *fsstat)
+{
+	struct nfs4_exception exception = {
+		.interruptible = true,
+	};
+	int err;
+	do {
+		err = nfs4_handle_exception(server,
+				_nfs4_proc_statfs(server, fhandle, fsstat),
+				&exception);
+	} while (exception.retry);
+	return err;
+}
+
+static int _nfs4_do_fsinfo(struct nfs_server *server, struct nfs_fh *fhandle,
+		struct nfs_fsinfo *fsinfo)
+{
+	struct nfs4_fsinfo_arg args = {
+		.fh = fhandle,
+		.bitmask = server->attr_bitmask,
+	};
+	struct nfs4_fsinfo_res res = {
+		.fsinfo = fsinfo,
+	};
+	struct rpc_message msg = {
+		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_FSINFO],
+		.rpc_argp = &args,
+		.rpc_resp = &res,
+	};
+
+	return nfs4_call_sync(server->client, server, &msg, &args.seq_args, &res.seq_res, 0);
+}
+
+static int nfs4_do_fsinfo(struct nfs_server *server, struct nfs_fh *fhandle, struct nfs_fsinfo *fsinfo)
+{
+	struct nfs4_exception exception = {
+		.interruptible = true,
+	};
+	int err;
+
+	do {
+		err = _nfs4_do_fsinfo(server, fhandle, fsinfo);
+		trace_nfs4_fsinfo(server, fhandle, fsinfo->fattr, err);
+		if (err == 0) {
+			nfs4_set_lease_period(server->nfs_client, fsinfo->lease_time * HZ);
+			break;
+		}
+		err = nfs4_handle_exception(server, err, &exception);
+	} while (exception.retry);
+	return err;
+}
+
+static int nfs4_proc_fsinfo(struct nfs_server *server, struct nfs_fh *fhandle, struct nfs_fsinfo *fsinfo)
+{
+	int error;
+
+	nfs_fattr_init(fsinfo->fattr);
+	error = nfs4_do_fsinfo(server, fhandle, fsinfo);
+	if (error == 0) {
+		/* block layout checks this! */
+		server->pnfs_blksize = fsinfo->blksize;
+		set_pnfs_layoutdriver(server, fhandle, fsinfo);
+	}
+
+	return error;
+}
+
+static int _nfs4_proc_pathconf(struct nfs_server *server, struct nfs_fh *fhandle,
+		struct nfs_pathconf *pathconf)
+{
+	struct nfs4_pathconf_arg args = {
+		.fh = fhandle,
+		.bitmask = server->attr_bitmask,
+	};
+	struct nfs4_pathconf_res res = {
+		.pathconf = pathconf,
+	};
+	struct rpc_message msg = {
+		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_PATHCONF],
+		.rpc_argp = &args,
+		.rpc_resp = &res,
+	};
+
+	/* None of the pathconf attributes are mandatory to implement */
+	if ((args.bitmask[0] & nfs4_pathconf_bitmap[0]) == 0) {
+		memset(pathconf, 0, sizeof(*pathconf));
+		return 0;
+	}
+
+	nfs_fattr_init(pathconf->fattr);
+	return nfs4_call_sync(server->client, server, &msg, &args.seq_args, &res.seq_res, 0);
+}
+
+static int nfs4_proc_pathconf(struct nfs_server *server, struct nfs_fh *fhandle,
+		struct nfs_pathconf *pathconf)
+{
+	struct nfs4_exception exception = {
+		.interruptible = true,
+	};
+	int err;
+
+	do {
+		err = nfs4_handle_exception(server,
+				_nfs4_proc_pathconf(server, fhandle, pathconf),
+				&exception);
+	} while (exception.retry);
+	return err;
+}
+
+int nfs4_set_rw_stateid(nfs4_stateid *stateid,
+		const struct nfs_open_context *ctx,
+		const struct nfs_lock_context *l_ctx,
+		fmode_t fmode)
+{
+	return nfs4_select_rw_stateid(ctx->state, fmode, l_ctx, stateid, NULL);
+}
+EXPORT_SYMBOL_GPL(nfs4_set_rw_stateid);
+
+static bool nfs4_stateid_is_current(nfs4_stateid *stateid,
+		const struct nfs_open_context *ctx,
+		const struct nfs_lock_context *l_ctx,
+		fmode_t fmode)
+{
+	nfs4_stateid _current_stateid;
+
+	/* If the current stateid represents a lost lock, then exit */
+	if (nfs4_set_rw_stateid(&_current_stateid, ctx, l_ctx, fmode) == -EIO)
+		return true;
+	return nfs4_stateid_match(stateid, &_current_stateid);
+}
+
+static bool nfs4_error_stateid_expired(int err)
+{
+	switch (err) {
+	case -NFS4ERR_DELEG_REVOKED:
+	case -NFS4ERR_ADMIN_REVOKED:
+	case -NFS4ERR_BAD_STATEID:
+	case -NFS4ERR_STALE_STATEID:
+	case -NFS4ERR_OLD_STATEID:
+	case -NFS4ERR_OPENMODE:
+	case -NFS4ERR_EXPIRED:
+		return true;
+	}
+	return false;
+}
+
+static int nfs4_read_done_cb(struct rpc_task *task, struct nfs_pgio_header *hdr)
+{
+	struct nfs_server *server = NFS_SERVER(hdr->inode);
+
+	trace_nfs4_read(hdr, task->tk_status);
+	if (task->tk_status < 0) {
+		struct nfs4_exception exception = {
+			.inode = hdr->inode,
+			.state = hdr->args.context->state,
+			.stateid = &hdr->args.stateid,
+		};
+		task->tk_status = nfs4_async_handle_exception(task,
+				server, task->tk_status, &exception);
+		if (exception.retry) {
+			rpc_restart_call_prepare(task);
+			return -EAGAIN;
+		}
+	}
+
+	if (task->tk_status > 0)
+		renew_lease(server, hdr->timestamp);
+	return 0;
+}
+
+static bool nfs4_read_stateid_changed(struct rpc_task *task,
+		struct nfs_pgio_args *args)
+{
+
+	if (!nfs4_error_stateid_expired(task->tk_status) ||
+		nfs4_stateid_is_current(&args->stateid,
+				args->context,
+				args->lock_context,
+				FMODE_READ))
+		return false;
+	rpc_restart_call_prepare(task);
+	return true;
+}
+
+static bool nfs4_read_plus_not_supported(struct rpc_task *task,
+					 struct nfs_pgio_header *hdr)
+{
+	struct nfs_server *server = NFS_SERVER(hdr->inode);
+	struct rpc_message *msg = &task->tk_msg;
+
+	if (msg->rpc_proc == &nfs4_procedures[NFSPROC4_CLNT_READ_PLUS] &&
+	    server->caps & NFS_CAP_READ_PLUS && task->tk_status == -ENOTSUPP) {
+		server->caps &= ~NFS_CAP_READ_PLUS;
+		msg->rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_READ];
+		rpc_restart_call_prepare(task);
+		return true;
+	}
+	return false;
+}
+
+static int nfs4_read_done(struct rpc_task *task, struct nfs_pgio_header *hdr)
+{
+	dprintk("--> %s\n", __func__);
+
+	if (!nfs4_sequence_done(task, &hdr->res.seq_res))
+		return -EAGAIN;
+	if (nfs4_read_stateid_changed(task, &hdr->args))
+		return -EAGAIN;
+	if (nfs4_read_plus_not_supported(task, hdr))
+		return -EAGAIN;
+	if (task->tk_status > 0)
+		nfs_invalidate_atime(hdr->inode);
+	return hdr->pgio_done_cb ? hdr->pgio_done_cb(task, hdr) :
+				    nfs4_read_done_cb(task, hdr);
+}
+
+#if defined CONFIG_NFS_V4_2 && defined CONFIG_NFS_V4_2_READ_PLUS
+static void nfs42_read_plus_support(struct nfs_server *server, struct rpc_message *msg)
+{
+	if (server->caps & NFS_CAP_READ_PLUS)
+		msg->rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_READ_PLUS];
+	else
+		msg->rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_READ];
+}
+#else
+static void nfs42_read_plus_support(struct nfs_server *server, struct rpc_message *msg)
+{
+	msg->rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_READ];
+}
+#endif /* CONFIG_NFS_V4_2 */
+
+static void nfs4_proc_read_setup(struct nfs_pgio_header *hdr,
+				 struct rpc_message *msg)
+{
+	hdr->timestamp   = jiffies;
+	if (!hdr->pgio_done_cb)
+		hdr->pgio_done_cb = nfs4_read_done_cb;
+	nfs42_read_plus_support(NFS_SERVER(hdr->inode), msg);
+	nfs4_init_sequence(&hdr->args.seq_args, &hdr->res.seq_res, 0, 0);
+}
+
+static int nfs4_proc_pgio_rpc_prepare(struct rpc_task *task,
+				      struct nfs_pgio_header *hdr)
+{
+	if (nfs4_setup_sequence(NFS_SERVER(hdr->inode)->nfs_client,
+			&hdr->args.seq_args,
+			&hdr->res.seq_res,
+			task))
+		return 0;
+	if (nfs4_set_rw_stateid(&hdr->args.stateid, hdr->args.context,
+				hdr->args.lock_context,
+				hdr->rw_mode) == -EIO)
+		return -EIO;
+	if (unlikely(test_bit(NFS_CONTEXT_BAD, &hdr->args.context->flags)))
+		return -EIO;
+	return 0;
+}
+
+static int nfs4_write_done_cb(struct rpc_task *task,
+			      struct nfs_pgio_header *hdr)
+{
+	struct inode *inode = hdr->inode;
+
+	trace_nfs4_write(hdr, task->tk_status);
+	if (task->tk_status < 0) {
+		struct nfs4_exception exception = {
+			.inode = hdr->inode,
+			.state = hdr->args.context->state,
+			.stateid = &hdr->args.stateid,
+		};
+		task->tk_status = nfs4_async_handle_exception(task,
+				NFS_SERVER(inode), task->tk_status,
+				&exception);
+		if (exception.retry) {
+			rpc_restart_call_prepare(task);
+			return -EAGAIN;
+		}
+	}
+	if (task->tk_status >= 0) {
+		renew_lease(NFS_SERVER(inode), hdr->timestamp);
+		nfs_writeback_update_inode(hdr);
+	}
+	return 0;
+}
+
+static bool nfs4_write_stateid_changed(struct rpc_task *task,
+		struct nfs_pgio_args *args)
+{
+
+	if (!nfs4_error_stateid_expired(task->tk_status) ||
+		nfs4_stateid_is_current(&args->stateid,
+				args->context,
+				args->lock_context,
+				FMODE_WRITE))
+		return false;
+	rpc_restart_call_prepare(task);
+	return true;
+}
+
+static int nfs4_write_done(struct rpc_task *task, struct nfs_pgio_header *hdr)
+{
+	if (!nfs4_sequence_done(task, &hdr->res.seq_res))
+		return -EAGAIN;
+	if (nfs4_write_stateid_changed(task, &hdr->args))
+		return -EAGAIN;
+	return hdr->pgio_done_cb ? hdr->pgio_done_cb(task, hdr) :
+		nfs4_write_done_cb(task, hdr);
+}
+
+static
+bool nfs4_write_need_cache_consistency_data(struct nfs_pgio_header *hdr)
+{
+	/* Don't request attributes for pNFS or O_DIRECT writes */
+	if (hdr->ds_clp != NULL || hdr->dreq != NULL)
+		return false;
+	/* Otherwise, request attributes if and only if we don't hold
+	 * a delegation
+	 */
+	return nfs4_have_delegation(hdr->inode, FMODE_READ) == 0;
+}
+
+static void nfs4_bitmask_set(__u32 bitmask[NFS4_BITMASK_SZ], const __u32 *src,
+			     struct inode *inode, struct nfs_server *server,
+			     struct nfs4_label *label)
+{
+	unsigned long cache_validity = READ_ONCE(NFS_I(inode)->cache_validity);
+	unsigned int i;
+
+	memcpy(bitmask, src, sizeof(*bitmask) * NFS4_BITMASK_SZ);
+
+	if (cache_validity & (NFS_INO_INVALID_CHANGE | NFS_INO_REVAL_PAGECACHE))
+		bitmask[0] |= FATTR4_WORD0_CHANGE;
+	if (cache_validity & NFS_INO_INVALID_ATIME)
+		bitmask[1] |= FATTR4_WORD1_TIME_ACCESS;
+	if (cache_validity & NFS_INO_INVALID_OTHER)
+		bitmask[1] |= FATTR4_WORD1_MODE | FATTR4_WORD1_OWNER |
+				FATTR4_WORD1_OWNER_GROUP |
+				FATTR4_WORD1_NUMLINKS;
+	if (label && label->len && cache_validity & NFS_INO_INVALID_LABEL)
+		bitmask[2] |= FATTR4_WORD2_SECURITY_LABEL;
+	if (cache_validity & NFS_INO_INVALID_CTIME)
+		bitmask[1] |= FATTR4_WORD1_TIME_METADATA;
+	if (cache_validity & NFS_INO_INVALID_MTIME)
+		bitmask[1] |= FATTR4_WORD1_TIME_MODIFY;
+	if (cache_validity & NFS_INO_INVALID_BLOCKS)
+		bitmask[1] |= FATTR4_WORD1_SPACE_USED;
+
+	if (nfs4_have_delegation(inode, FMODE_READ) &&
+	    !(cache_validity & NFS_INO_REVAL_FORCED))
+		bitmask[0] &= ~FATTR4_WORD0_SIZE;
+	else if (cache_validity &
+		 (NFS_INO_INVALID_SIZE | NFS_INO_REVAL_PAGECACHE))
+		bitmask[0] |= FATTR4_WORD0_SIZE;
+
+	for (i = 0; i < NFS4_BITMASK_SZ; i++)
+		bitmask[i] &= server->attr_bitmask[i];
+}
+
+static void nfs4_proc_write_setup(struct nfs_pgio_header *hdr,
+				  struct rpc_message *msg,
+				  struct rpc_clnt **clnt)
+{
+	struct nfs_server *server = NFS_SERVER(hdr->inode);
+
+	if (!nfs4_write_need_cache_consistency_data(hdr)) {
+		hdr->args.bitmask = NULL;
+		hdr->res.fattr = NULL;
+	} else {
+		nfs4_bitmask_set(hdr->args.bitmask_store,
+				 server->cache_consistency_bitmask,
+				 hdr->inode, server, NULL);
+		hdr->args.bitmask = hdr->args.bitmask_store;
+	}
+
+	if (!hdr->pgio_done_cb)
+		hdr->pgio_done_cb = nfs4_write_done_cb;
+	hdr->res.server = server;
+	hdr->timestamp   = jiffies;
+
+	msg->rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_WRITE];
+	nfs4_init_sequence(&hdr->args.seq_args, &hdr->res.seq_res, 0, 0);
+	nfs4_state_protect_write(hdr->ds_clp ? hdr->ds_clp : server->nfs_client, clnt, msg, hdr);
+}
+
+static void nfs4_proc_commit_rpc_prepare(struct rpc_task *task, struct nfs_commit_data *data)
+{
+	nfs4_setup_sequence(NFS_SERVER(data->inode)->nfs_client,
+			&data->args.seq_args,
+			&data->res.seq_res,
+			task);
+}
+
+static int nfs4_commit_done_cb(struct rpc_task *task, struct nfs_commit_data *data)
+{
+	struct inode *inode = data->inode;
+
+	trace_nfs4_commit(data, task->tk_status);
+	if (nfs4_async_handle_error(task, NFS_SERVER(inode),
+				    NULL, NULL) == -EAGAIN) {
+		rpc_restart_call_prepare(task);
+		return -EAGAIN;
+	}
+	return 0;
+}
+
+static int nfs4_commit_done(struct rpc_task *task, struct nfs_commit_data *data)
+{
+	if (!nfs4_sequence_done(task, &data->res.seq_res))
+		return -EAGAIN;
+	return data->commit_done_cb(task, data);
+}
+
+static void nfs4_proc_commit_setup(struct nfs_commit_data *data, struct rpc_message *msg,
+				   struct rpc_clnt **clnt)
+{
+	struct nfs_server *server = NFS_SERVER(data->inode);
+
+	if (data->commit_done_cb == NULL)
+		data->commit_done_cb = nfs4_commit_done_cb;
+	data->res.server = server;
+	msg->rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_COMMIT];
+	nfs4_init_sequence(&data->args.seq_args, &data->res.seq_res, 1, 0);
+	nfs4_state_protect(data->ds_clp ? data->ds_clp : server->nfs_client,
+			NFS_SP4_MACH_CRED_COMMIT, clnt, msg);
+}
+
+static int _nfs4_proc_commit(struct file *dst, struct nfs_commitargs *args,
+				struct nfs_commitres *res)
+{
+	struct inode *dst_inode = file_inode(dst);
+	struct nfs_server *server = NFS_SERVER(dst_inode);
+	struct rpc_message msg = {
+		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_COMMIT],
+		.rpc_argp = args,
+		.rpc_resp = res,
+	};
+
+	args->fh = NFS_FH(dst_inode);
+	return nfs4_call_sync(server->client, server, &msg,
+			&args->seq_args, &res->seq_res, 1);
+}
+
+int nfs4_proc_commit(struct file *dst, __u64 offset, __u32 count, struct nfs_commitres *res)
+{
+	struct nfs_commitargs args = {
+		.offset = offset,
+		.count = count,
+	};
+	struct nfs_server *dst_server = NFS_SERVER(file_inode(dst));
+	struct nfs4_exception exception = { };
+	int status;
+
+	do {
+		status = _nfs4_proc_commit(dst, &args, res);
+		status = nfs4_handle_exception(dst_server, status, &exception);
+	} while (exception.retry);
+
+	return status;
+}
+
+struct nfs4_renewdata {
+	struct nfs_client	*client;
+	unsigned long		timestamp;
+};
+
+/*
+ * nfs4_proc_async_renew(): This is not one of the nfs_rpc_ops; it is a special
+ * standalone procedure for queueing an asynchronous RENEW.
+ */
+static void nfs4_renew_release(void *calldata)
+{
+	struct nfs4_renewdata *data = calldata;
+	struct nfs_client *clp = data->client;
+
+	if (refcount_read(&clp->cl_count) > 1)
+		nfs4_schedule_state_renewal(clp);
+	nfs_put_client(clp);
+	kfree(data);
+}
+
+static void nfs4_renew_done(struct rpc_task *task, void *calldata)
+{
+	struct nfs4_renewdata *data = calldata;
+	struct nfs_client *clp = data->client;
+	unsigned long timestamp = data->timestamp;
+
+	trace_nfs4_renew_async(clp, task->tk_status);
+	switch (task->tk_status) {
+	case 0:
+		break;
+	case -NFS4ERR_LEASE_MOVED:
+		nfs4_schedule_lease_moved_recovery(clp);
+		break;
+	default:
+		/* Unless we're shutting down, schedule state recovery! */
+		if (test_bit(NFS_CS_RENEWD, &clp->cl_res_state) == 0)
+			return;
+		if (task->tk_status != NFS4ERR_CB_PATH_DOWN) {
+			nfs4_schedule_lease_recovery(clp);
+			return;
+		}
+		nfs4_schedule_path_down_recovery(clp);
+	}
+	do_renew_lease(clp, timestamp);
+}
+
+static const struct rpc_call_ops nfs4_renew_ops = {
+	.rpc_call_done = nfs4_renew_done,
+	.rpc_release = nfs4_renew_release,
+};
+
+static int nfs4_proc_async_renew(struct nfs_client *clp, const struct cred *cred, unsigned renew_flags)
+{
+	struct rpc_message msg = {
+		.rpc_proc	= &nfs4_procedures[NFSPROC4_CLNT_RENEW],
+		.rpc_argp	= clp,
+		.rpc_cred	= cred,
+	};
+	struct nfs4_renewdata *data;
+
+	if (renew_flags == 0)
+		return 0;
+	if (!refcount_inc_not_zero(&clp->cl_count))
+		return -EIO;
+	data = kmalloc(sizeof(*data), GFP_NOFS);
+	if (data == NULL) {
+		nfs_put_client(clp);
+		return -ENOMEM;
+	}
+	data->client = clp;
+	data->timestamp = jiffies;
+	return rpc_call_async(clp->cl_rpcclient, &msg, RPC_TASK_TIMEOUT,
+			&nfs4_renew_ops, data);
+}
+
+static int nfs4_proc_renew(struct nfs_client *clp, const struct cred *cred)
+{
+	struct rpc_message msg = {
+		.rpc_proc	= &nfs4_procedures[NFSPROC4_CLNT_RENEW],
+		.rpc_argp	= clp,
+		.rpc_cred	= cred,
+	};
+	unsigned long now = jiffies;
+	int status;
+
+	status = rpc_call_sync(clp->cl_rpcclient, &msg, RPC_TASK_TIMEOUT);
+	if (status < 0)
+		return status;
+	do_renew_lease(clp, now);
+	return 0;
+}
+
+static inline int nfs4_server_supports_acls(struct nfs_server *server)
+{
+	return server->caps & NFS_CAP_ACLS;
+}
+
+/* Assuming that XATTR_SIZE_MAX is a multiple of PAGE_SIZE, and that
+ * it's OK to put sizeof(void) * (XATTR_SIZE_MAX/PAGE_SIZE) bytes on
+ * the stack.
+ */
+#define NFS4ACL_MAXPAGES DIV_ROUND_UP(XATTR_SIZE_MAX, PAGE_SIZE)
+
+int nfs4_buf_to_pages_noslab(const void *buf, size_t buflen,
+		struct page **pages)
+{
+	struct page *newpage, **spages;
+	int rc = 0;
+	size_t len;
+	spages = pages;
+
+	do {
+		len = min_t(size_t, PAGE_SIZE, buflen);
+		newpage = alloc_page(GFP_KERNEL);
+
+		if (newpage == NULL)
+			goto unwind;
+		memcpy(page_address(newpage), buf, len);
+		buf += len;
+		buflen -= len;
+		*pages++ = newpage;
+		rc++;
+	} while (buflen != 0);
+
+	return rc;
+
+unwind:
+	for(; rc > 0; rc--)
+		__free_page(spages[rc-1]);
+	return -ENOMEM;
+}
+
+struct nfs4_cached_acl {
+	int cached;
+	size_t len;
+	char data[];
+};
+
+static void nfs4_set_cached_acl(struct inode *inode, struct nfs4_cached_acl *acl)
+{
+	struct nfs_inode *nfsi = NFS_I(inode);
+
+	spin_lock(&inode->i_lock);
+	kfree(nfsi->nfs4_acl);
+	nfsi->nfs4_acl = acl;
+	spin_unlock(&inode->i_lock);
+}
+
+static void nfs4_zap_acl_attr(struct inode *inode)
+{
+	nfs4_set_cached_acl(inode, NULL);
+}
+
+static inline ssize_t nfs4_read_cached_acl(struct inode *inode, char *buf, size_t buflen)
+{
+	struct nfs_inode *nfsi = NFS_I(inode);
+	struct nfs4_cached_acl *acl;
+	int ret = -ENOENT;
+
+	spin_lock(&inode->i_lock);
+	acl = nfsi->nfs4_acl;
+	if (acl == NULL)
+		goto out;
+	if (buf == NULL) /* user is just asking for length */
+		goto out_len;
+	if (acl->cached == 0)
+		goto out;
+	ret = -ERANGE; /* see getxattr(2) man page */
+	if (acl->len > buflen)
+		goto out;
+	memcpy(buf, acl->data, acl->len);
+out_len:
+	ret = acl->len;
+out:
+	spin_unlock(&inode->i_lock);
+	return ret;
+}
+
+static void nfs4_write_cached_acl(struct inode *inode, struct page **pages, size_t pgbase, size_t acl_len)
+{
+	struct nfs4_cached_acl *acl;
+	size_t buflen = sizeof(*acl) + acl_len;
+
+	if (buflen <= PAGE_SIZE) {
+		acl = kmalloc(buflen, GFP_KERNEL);
+		if (acl == NULL)
+			goto out;
+		acl->cached = 1;
+		_copy_from_pages(acl->data, pages, pgbase, acl_len);
+	} else {
+		acl = kmalloc(sizeof(*acl), GFP_KERNEL);
+		if (acl == NULL)
+			goto out;
+		acl->cached = 0;
+	}
+	acl->len = acl_len;
+out:
+	nfs4_set_cached_acl(inode, acl);
+}
+
+/*
+ * The getxattr API returns the required buffer length when called with a
+ * NULL buf. The NFSv4 acl tool then calls getxattr again after allocating
+ * the required buf.  On a NULL buf, we send a page of data to the server
+ * guessing that the ACL request can be serviced by a page. If so, we cache
+ * up to the page of ACL data, and the 2nd call to getxattr is serviced by
+ * the cache. If not so, we throw away the page, and cache the required
+ * length. The next getxattr call will then produce another round trip to
+ * the server, this time with the input buf of the required size.
+ */
+static ssize_t __nfs4_get_acl_uncached(struct inode *inode, void *buf, size_t buflen)
+{
+	struct page **pages;
+	struct nfs_getaclargs args = {
+		.fh = NFS_FH(inode),
+		.acl_len = buflen,
+	};
+	struct nfs_getaclres res = {
+		.acl_len = buflen,
+	};
+	struct rpc_message msg = {
+		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_GETACL],
+		.rpc_argp = &args,
+		.rpc_resp = &res,
+	};
+	unsigned int npages;
+	int ret = -ENOMEM, i;
+	struct nfs_server *server = NFS_SERVER(inode);
+
+	if (buflen == 0)
+		buflen = server->rsize;
+
+	npages = DIV_ROUND_UP(buflen, PAGE_SIZE) + 1;
+	pages = kmalloc_array(npages, sizeof(struct page *), GFP_NOFS);
+	if (!pages)
+		return -ENOMEM;
+
+	args.acl_pages = pages;
+
+	for (i = 0; i < npages; i++) {
+		pages[i] = alloc_page(GFP_KERNEL);
+		if (!pages[i])
+			goto out_free;
+	}
+
+	/* for decoding across pages */
+	res.acl_scratch = alloc_page(GFP_KERNEL);
+	if (!res.acl_scratch)
+		goto out_free;
+
+	args.acl_len = npages * PAGE_SIZE;
+
+	dprintk("%s  buf %p buflen %zu npages %d args.acl_len %zu\n",
+		__func__, buf, buflen, npages, args.acl_len);
+	ret = nfs4_call_sync(NFS_SERVER(inode)->client, NFS_SERVER(inode),
+			     &msg, &args.seq_args, &res.seq_res, 0);
+	if (ret)
+		goto out_free;
+
+	/* Handle the case where the passed-in buffer is too short */
+	if (res.acl_flags & NFS4_ACL_TRUNC) {
+		/* Did the user only issue a request for the acl length? */
+		if (buf == NULL)
+			goto out_ok;
+		ret = -ERANGE;
+		goto out_free;
+	}
+	nfs4_write_cached_acl(inode, pages, res.acl_data_offset, res.acl_len);
+	if (buf) {
+		if (res.acl_len > buflen) {
+			ret = -ERANGE;
+			goto out_free;
+		}
+		_copy_from_pages(buf, pages, res.acl_data_offset, res.acl_len);
+	}
+out_ok:
+	ret = res.acl_len;
+out_free:
+	while (--i >= 0)
+		__free_page(pages[i]);
+	if (res.acl_scratch)
+		__free_page(res.acl_scratch);
+	kfree(pages);
+	return ret;
+}
+
+static ssize_t nfs4_get_acl_uncached(struct inode *inode, void *buf, size_t buflen)
+{
+	struct nfs4_exception exception = {
+		.interruptible = true,
+	};
+	ssize_t ret;
+	do {
+		ret = __nfs4_get_acl_uncached(inode, buf, buflen);
+		trace_nfs4_get_acl(inode, ret);
+		if (ret >= 0)
+			break;
+		ret = nfs4_handle_exception(NFS_SERVER(inode), ret, &exception);
+	} while (exception.retry);
+	return ret;
+}
+
+static ssize_t nfs4_proc_get_acl(struct inode *inode, void *buf, size_t buflen)
+{
+	struct nfs_server *server = NFS_SERVER(inode);
+	int ret;
+
+	if (!nfs4_server_supports_acls(server))
+		return -EOPNOTSUPP;
+	ret = nfs_revalidate_inode(server, inode);
+	if (ret < 0)
+		return ret;
+	if (NFS_I(inode)->cache_validity & NFS_INO_INVALID_ACL)
+		nfs_zap_acl_cache(inode);
+	ret = nfs4_read_cached_acl(inode, buf, buflen);
+	if (ret != -ENOENT)
+		/* -ENOENT is returned if there is no ACL or if there is an ACL
+		 * but no cached acl data, just the acl length */
+		return ret;
+	return nfs4_get_acl_uncached(inode, buf, buflen);
+}
+
+static int __nfs4_proc_set_acl(struct inode *inode, const void *buf, size_t buflen)
+{
+	struct nfs_server *server = NFS_SERVER(inode);
+	struct page *pages[NFS4ACL_MAXPAGES];
+	struct nfs_setaclargs arg = {
+		.fh		= NFS_FH(inode),
+		.acl_pages	= pages,
+		.acl_len	= buflen,
+	};
+	struct nfs_setaclres res;
+	struct rpc_message msg = {
+		.rpc_proc	= &nfs4_procedures[NFSPROC4_CLNT_SETACL],
+		.rpc_argp	= &arg,
+		.rpc_resp	= &res,
+	};
+	unsigned int npages = DIV_ROUND_UP(buflen, PAGE_SIZE);
+	int ret, i;
+
+	/* You can't remove system.nfs4_acl: */
+	if (buflen == 0)
+		return -EINVAL;
+	if (!nfs4_server_supports_acls(server))
+		return -EOPNOTSUPP;
+	if (npages > ARRAY_SIZE(pages))
+		return -ERANGE;
+	i = nfs4_buf_to_pages_noslab(buf, buflen, arg.acl_pages);
+	if (i < 0)
+		return i;
+	nfs4_inode_make_writeable(inode);
+	ret = nfs4_call_sync(server->client, server, &msg, &arg.seq_args, &res.seq_res, 1);
+
+	/*
+	 * Free each page after tx, so the only ref left is
+	 * held by the network stack
+	 */
+	for (; i > 0; i--)
+		put_page(pages[i-1]);
+
+	/*
+	 * Acl update can result in inode attribute update.
+	 * so mark the attribute cache invalid.
+	 */
+	spin_lock(&inode->i_lock);
+	NFS_I(inode)->cache_validity |= NFS_INO_INVALID_CHANGE
+		| NFS_INO_INVALID_CTIME
+		| NFS_INO_REVAL_FORCED;
+	spin_unlock(&inode->i_lock);
+	nfs_access_zap_cache(inode);
+	nfs_zap_acl_cache(inode);
+	return ret;
+}
+
+static int nfs4_proc_set_acl(struct inode *inode, const void *buf, size_t buflen)
+{
+	struct nfs4_exception exception = { };
+	int err;
+	do {
+		err = __nfs4_proc_set_acl(inode, buf, buflen);
+		trace_nfs4_set_acl(inode, err);
+		if (err == -NFS4ERR_BADOWNER || err == -NFS4ERR_BADNAME) {
+			/*
+			 * no need to retry since the kernel
+			 * isn't involved in encoding the ACEs.
+			 */
+			err = -EINVAL;
+			break;
+		}
+		err = nfs4_handle_exception(NFS_SERVER(inode), err,
+				&exception);
+	} while (exception.retry);
+	return err;
+}
+
+#ifdef CONFIG_NFS_V4_SECURITY_LABEL
+static int _nfs4_get_security_label(struct inode *inode, void *buf,
+					size_t buflen)
+{
+	struct nfs_server *server = NFS_SERVER(inode);
+	struct nfs_fattr fattr;
+	struct nfs4_label label = {0, 0, buflen, buf};
+
+	u32 bitmask[3] = { 0, 0, FATTR4_WORD2_SECURITY_LABEL };
+	struct nfs4_getattr_arg arg = {
+		.fh		= NFS_FH(inode),
+		.bitmask	= bitmask,
+	};
+	struct nfs4_getattr_res res = {
+		.fattr		= &fattr,
+		.label		= &label,
+		.server		= server,
+	};
+	struct rpc_message msg = {
+		.rpc_proc	= &nfs4_procedures[NFSPROC4_CLNT_GETATTR],
+		.rpc_argp	= &arg,
+		.rpc_resp	= &res,
+	};
+	int ret;
+
+	nfs_fattr_init(&fattr);
+
+	ret = nfs4_call_sync(server->client, server, &msg, &arg.seq_args, &res.seq_res, 0);
+	if (ret)
+		return ret;
+	if (!(fattr.valid & NFS_ATTR_FATTR_V4_SECURITY_LABEL))
+		return -ENOENT;
+	return label.len;
+}
+
+static int nfs4_get_security_label(struct inode *inode, void *buf,
+					size_t buflen)
+{
+	struct nfs4_exception exception = {
+		.interruptible = true,
+	};
+	int err;
+
+	if (!nfs_server_capable(inode, NFS_CAP_SECURITY_LABEL))
+		return -EOPNOTSUPP;
+
+	do {
+		err = _nfs4_get_security_label(inode, buf, buflen);
+		trace_nfs4_get_security_label(inode, err);
+		err = nfs4_handle_exception(NFS_SERVER(inode), err,
+				&exception);
+	} while (exception.retry);
+	return err;
+}
+
+static int _nfs4_do_set_security_label(struct inode *inode,
+		struct nfs4_label *ilabel,
+		struct nfs_fattr *fattr,
+		struct nfs4_label *olabel)
+{
+
+	struct iattr sattr = {0};
+	struct nfs_server *server = NFS_SERVER(inode);
+	const u32 bitmask[3] = { 0, 0, FATTR4_WORD2_SECURITY_LABEL };
+	struct nfs_setattrargs arg = {
+		.fh		= NFS_FH(inode),
+		.iap		= &sattr,
+		.server		= server,
+		.bitmask	= bitmask,
+		.label		= ilabel,
+	};
+	struct nfs_setattrres res = {
+		.fattr		= fattr,
+		.label		= olabel,
+		.server		= server,
+	};
+	struct rpc_message msg = {
+		.rpc_proc	= &nfs4_procedures[NFSPROC4_CLNT_SETATTR],
+		.rpc_argp	= &arg,
+		.rpc_resp	= &res,
+	};
+	int status;
+
+	nfs4_stateid_copy(&arg.stateid, &zero_stateid);
+
+	status = nfs4_call_sync(server->client, server, &msg, &arg.seq_args, &res.seq_res, 1);
+	if (status)
+		dprintk("%s failed: %d\n", __func__, status);
+
+	return status;
+}
+
+static int nfs4_do_set_security_label(struct inode *inode,
+		struct nfs4_label *ilabel,
+		struct nfs_fattr *fattr,
+		struct nfs4_label *olabel)
+{
+	struct nfs4_exception exception = { };
+	int err;
+
+	do {
+		err = _nfs4_do_set_security_label(inode, ilabel,
+				fattr, olabel);
+		trace_nfs4_set_security_label(inode, err);
+		err = nfs4_handle_exception(NFS_SERVER(inode), err,
+				&exception);
+	} while (exception.retry);
+	return err;
+}
+
+static int
+nfs4_set_security_label(struct inode *inode, const void *buf, size_t buflen)
+{
+	struct nfs4_label ilabel, *olabel = NULL;
+	struct nfs_fattr fattr;
+	int status;
+
+	if (!nfs_server_capable(inode, NFS_CAP_SECURITY_LABEL))
+		return -EOPNOTSUPP;
+
+	nfs_fattr_init(&fattr);
+
+	ilabel.pi = 0;
+	ilabel.lfs = 0;
+	ilabel.label = (char *)buf;
+	ilabel.len = buflen;
+
+	olabel = nfs4_label_alloc(NFS_SERVER(inode), GFP_KERNEL);
+	if (IS_ERR(olabel)) {
+		status = -PTR_ERR(olabel);
+		goto out;
+	}
+
+	status = nfs4_do_set_security_label(inode, &ilabel, &fattr, olabel);
+	if (status == 0)
+		nfs_setsecurity(inode, &fattr, olabel);
+
+	nfs4_label_free(olabel);
+out:
+	return status;
+}
+#endif	/* CONFIG_NFS_V4_SECURITY_LABEL */
+
+
+static void nfs4_init_boot_verifier(const struct nfs_client *clp,
+				    nfs4_verifier *bootverf)
+{
+	__be32 verf[2];
+
+	if (test_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state)) {
+		/* An impossible timestamp guarantees this value
+		 * will never match a generated boot time. */
+		verf[0] = cpu_to_be32(U32_MAX);
+		verf[1] = cpu_to_be32(U32_MAX);
+	} else {
+		struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
+		u64 ns = ktime_to_ns(nn->boot_time);
+
+		verf[0] = cpu_to_be32(ns >> 32);
+		verf[1] = cpu_to_be32(ns);
+	}
+	memcpy(bootverf->data, verf, sizeof(bootverf->data));
+}
+
+static size_t
+nfs4_get_uniquifier(struct nfs_client *clp, char *buf, size_t buflen)
+{
+	struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
+	struct nfs_netns_client *nn_clp = nn->nfs_client;
+	const char *id;
+
+	buf[0] = '\0';
+
+	if (nn_clp) {
+		rcu_read_lock();
+		id = rcu_dereference(nn_clp->identifier);
+		if (id)
+			strscpy(buf, id, buflen);
+		rcu_read_unlock();
+	}
+
+	if (nfs4_client_id_uniquifier[0] != '\0' && buf[0] == '\0')
+		strscpy(buf, nfs4_client_id_uniquifier, buflen);
+
+	return strlen(buf);
+}
+
+static int
+nfs4_init_nonuniform_client_string(struct nfs_client *clp)
+{
+	char buf[NFS4_CLIENT_ID_UNIQ_LEN];
+	size_t buflen;
+	size_t len;
+	char *str;
+
+	if (clp->cl_owner_id != NULL)
+		return 0;
+
+	rcu_read_lock();
+	len = 14 +
+		strlen(clp->cl_rpcclient->cl_nodename) +
+		1 +
+		strlen(rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_ADDR)) +
+		1;
+	rcu_read_unlock();
+
+	buflen = nfs4_get_uniquifier(clp, buf, sizeof(buf));
+	if (buflen)
+		len += buflen + 1;
+
+	if (len > NFS4_OPAQUE_LIMIT + 1)
+		return -EINVAL;
+
+	/*
+	 * Since this string is allocated at mount time, and held until the
+	 * nfs_client is destroyed, we can use GFP_KERNEL here w/o worrying
+	 * about a memory-reclaim deadlock.
+	 */
+	str = kmalloc(len, GFP_KERNEL);
+	if (!str)
+		return -ENOMEM;
+
+	rcu_read_lock();
+	if (buflen)
+		scnprintf(str, len, "Linux NFSv4.0 %s/%s/%s",
+			  clp->cl_rpcclient->cl_nodename, buf,
+			  rpc_peeraddr2str(clp->cl_rpcclient,
+					   RPC_DISPLAY_ADDR));
+	else
+		scnprintf(str, len, "Linux NFSv4.0 %s/%s",
+			  clp->cl_rpcclient->cl_nodename,
+			  rpc_peeraddr2str(clp->cl_rpcclient,
+					   RPC_DISPLAY_ADDR));
+	rcu_read_unlock();
+
+	clp->cl_owner_id = str;
+	return 0;
+}
+
+static int
+nfs4_init_uniform_client_string(struct nfs_client *clp)
+{
+	char buf[NFS4_CLIENT_ID_UNIQ_LEN];
+	size_t buflen;
+	size_t len;
+	char *str;
+
+	if (clp->cl_owner_id != NULL)
+		return 0;
+
+	len = 10 + 10 + 1 + 10 + 1 +
+		strlen(clp->cl_rpcclient->cl_nodename) + 1;
+
+	buflen = nfs4_get_uniquifier(clp, buf, sizeof(buf));
+	if (buflen)
+		len += buflen + 1;
+
+	if (len > NFS4_OPAQUE_LIMIT + 1)
+		return -EINVAL;
+
+	/*
+	 * Since this string is allocated at mount time, and held until the
+	 * nfs_client is destroyed, we can use GFP_KERNEL here w/o worrying
+	 * about a memory-reclaim deadlock.
+	 */
+	str = kmalloc(len, GFP_KERNEL);
+	if (!str)
+		return -ENOMEM;
+
+	if (buflen)
+		scnprintf(str, len, "Linux NFSv%u.%u %s/%s",
+			  clp->rpc_ops->version, clp->cl_minorversion,
+			  buf, clp->cl_rpcclient->cl_nodename);
+	else
+		scnprintf(str, len, "Linux NFSv%u.%u %s",
+			  clp->rpc_ops->version, clp->cl_minorversion,
+			  clp->cl_rpcclient->cl_nodename);
+	clp->cl_owner_id = str;
+	return 0;
+}
+
+/*
+ * nfs4_callback_up_net() starts only "tcp" and "tcp6" callback
+ * services.  Advertise one based on the address family of the
+ * clientaddr.
+ */
+static unsigned int
+nfs4_init_callback_netid(const struct nfs_client *clp, char *buf, size_t len)
+{
+	if (strchr(clp->cl_ipaddr, ':') != NULL)
+		return scnprintf(buf, len, "tcp6");
+	else
+		return scnprintf(buf, len, "tcp");
+}
+
+static void nfs4_setclientid_done(struct rpc_task *task, void *calldata)
+{
+	struct nfs4_setclientid *sc = calldata;
+
+	if (task->tk_status == 0)
+		sc->sc_cred = get_rpccred(task->tk_rqstp->rq_cred);
+}
+
+static const struct rpc_call_ops nfs4_setclientid_ops = {
+	.rpc_call_done = nfs4_setclientid_done,
+};
+
+/**
+ * nfs4_proc_setclientid - Negotiate client ID
+ * @clp: state data structure
+ * @program: RPC program for NFSv4 callback service
+ * @port: IP port number for NFS4 callback service
+ * @cred: credential to use for this call
+ * @res: where to place the result
+ *
+ * Returns zero, a negative errno, or a negative NFS4ERR status code.
+ */
+int nfs4_proc_setclientid(struct nfs_client *clp, u32 program,
+		unsigned short port, const struct cred *cred,
+		struct nfs4_setclientid_res *res)
+{
+	nfs4_verifier sc_verifier;
+	struct nfs4_setclientid setclientid = {
+		.sc_verifier = &sc_verifier,
+		.sc_prog = program,
+		.sc_clnt = clp,
+	};
+	struct rpc_message msg = {
+		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_SETCLIENTID],
+		.rpc_argp = &setclientid,
+		.rpc_resp = res,
+		.rpc_cred = cred,
+	};
+	struct rpc_task_setup task_setup_data = {
+		.rpc_client = clp->cl_rpcclient,
+		.rpc_message = &msg,
+		.callback_ops = &nfs4_setclientid_ops,
+		.callback_data = &setclientid,
+		.flags = RPC_TASK_TIMEOUT | RPC_TASK_NO_ROUND_ROBIN,
+	};
+	unsigned long now = jiffies;
+	int status;
+
+	/* nfs_client_id4 */
+	nfs4_init_boot_verifier(clp, &sc_verifier);
+
+	if (test_bit(NFS_CS_MIGRATION, &clp->cl_flags))
+		status = nfs4_init_uniform_client_string(clp);
+	else
+		status = nfs4_init_nonuniform_client_string(clp);
+
+	if (status)
+		goto out;
+
+	/* cb_client4 */
+	setclientid.sc_netid_len =
+				nfs4_init_callback_netid(clp,
+						setclientid.sc_netid,
+						sizeof(setclientid.sc_netid));
+	setclientid.sc_uaddr_len = scnprintf(setclientid.sc_uaddr,
+				sizeof(setclientid.sc_uaddr), "%s.%u.%u",
+				clp->cl_ipaddr, port >> 8, port & 255);
+
+	dprintk("NFS call  setclientid auth=%s, '%s'\n",
+		clp->cl_rpcclient->cl_auth->au_ops->au_name,
+		clp->cl_owner_id);
+
+	status = nfs4_call_sync_custom(&task_setup_data);
+	if (setclientid.sc_cred) {
+		kfree(clp->cl_acceptor);
+		clp->cl_acceptor = rpcauth_stringify_acceptor(setclientid.sc_cred);
+		put_rpccred(setclientid.sc_cred);
+	}
+
+	if (status == 0)
+		do_renew_lease(clp, now);
+out:
+	trace_nfs4_setclientid(clp, status);
+	dprintk("NFS reply setclientid: %d\n", status);
+	return status;
+}
+
+/**
+ * nfs4_proc_setclientid_confirm - Confirm client ID
+ * @clp: state data structure
+ * @arg: result of a previous SETCLIENTID
+ * @cred: credential to use for this call
+ *
+ * Returns zero, a negative errno, or a negative NFS4ERR status code.
+ */
+int nfs4_proc_setclientid_confirm(struct nfs_client *clp,
+		struct nfs4_setclientid_res *arg,
+		const struct cred *cred)
+{
+	struct rpc_message msg = {
+		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_SETCLIENTID_CONFIRM],
+		.rpc_argp = arg,
+		.rpc_cred = cred,
+	};
+	int status;
+
+	dprintk("NFS call  setclientid_confirm auth=%s, (client ID %llx)\n",
+		clp->cl_rpcclient->cl_auth->au_ops->au_name,
+		clp->cl_clientid);
+	status = rpc_call_sync(clp->cl_rpcclient, &msg,
+			       RPC_TASK_TIMEOUT | RPC_TASK_NO_ROUND_ROBIN);
+	trace_nfs4_setclientid_confirm(clp, status);
+	dprintk("NFS reply setclientid_confirm: %d\n", status);
+	return status;
+}
+
+struct nfs4_delegreturndata {
+	struct nfs4_delegreturnargs args;
+	struct nfs4_delegreturnres res;
+	struct nfs_fh fh;
+	nfs4_stateid stateid;
+	unsigned long timestamp;
+	struct {
+		struct nfs4_layoutreturn_args arg;
+		struct nfs4_layoutreturn_res res;
+		struct nfs4_xdr_opaque_data ld_private;
+		u32 roc_barrier;
+		bool roc;
+	} lr;
+	struct nfs_fattr fattr;
+	int rpc_status;
+	struct inode *inode;
+};
+
+static void nfs4_delegreturn_done(struct rpc_task *task, void *calldata)
+{
+	struct nfs4_delegreturndata *data = calldata;
+	struct nfs4_exception exception = {
+		.inode = data->inode,
+		.stateid = &data->stateid,
+		.task_is_privileged = data->args.seq_args.sa_privileged,
+	};
+
+	if (!nfs4_sequence_done(task, &data->res.seq_res))
+		return;
+
+	trace_nfs4_delegreturn_exit(&data->args, &data->res, task->tk_status);
+
+	/* Handle Layoutreturn errors */
+	if (pnfs_roc_done(task, &data->args.lr_args, &data->res.lr_res,
+			  &data->res.lr_ret) == -EAGAIN)
+		goto out_restart;
+
+	switch (task->tk_status) {
+	case 0:
+		renew_lease(data->res.server, data->timestamp);
+		break;
+	case -NFS4ERR_ADMIN_REVOKED:
+	case -NFS4ERR_DELEG_REVOKED:
+	case -NFS4ERR_EXPIRED:
+		nfs4_free_revoked_stateid(data->res.server,
+				data->args.stateid,
+				task->tk_msg.rpc_cred);
+		fallthrough;
+	case -NFS4ERR_BAD_STATEID:
+	case -NFS4ERR_STALE_STATEID:
+	case -ETIMEDOUT:
+		task->tk_status = 0;
+		break;
+	case -NFS4ERR_OLD_STATEID:
+		if (!nfs4_refresh_delegation_stateid(&data->stateid, data->inode))
+			nfs4_stateid_seqid_inc(&data->stateid);
+		if (data->args.bitmask) {
+			data->args.bitmask = NULL;
+			data->res.fattr = NULL;
+		}
+		goto out_restart;
+	case -NFS4ERR_ACCESS:
+		if (data->args.bitmask) {
+			data->args.bitmask = NULL;
+			data->res.fattr = NULL;
+			goto out_restart;
+		}
+		fallthrough;
+	default:
+		task->tk_status = nfs4_async_handle_exception(task,
+				data->res.server, task->tk_status,
+				&exception);
+		if (exception.retry)
+			goto out_restart;
+	}
+	nfs_delegation_mark_returned(data->inode, data->args.stateid);
+	data->rpc_status = task->tk_status;
+	return;
+out_restart:
+	task->tk_status = 0;
+	rpc_restart_call_prepare(task);
+}
+
+static void nfs4_delegreturn_release(void *calldata)
+{
+	struct nfs4_delegreturndata *data = calldata;
+	struct inode *inode = data->inode;
+
+	if (data->lr.roc)
+		pnfs_roc_release(&data->lr.arg, &data->lr.res,
+				 data->res.lr_ret);
+	if (inode) {
+		nfs4_fattr_set_prechange(&data->fattr,
+					 inode_peek_iversion_raw(inode));
+		nfs_refresh_inode(inode, &data->fattr);
+		nfs_iput_and_deactive(inode);
+	}
+	kfree(calldata);
+}
+
+static void nfs4_delegreturn_prepare(struct rpc_task *task, void *data)
+{
+	struct nfs4_delegreturndata *d_data;
+	struct pnfs_layout_hdr *lo;
+
+	d_data = (struct nfs4_delegreturndata *)data;
+
+	if (!d_data->lr.roc && nfs4_wait_on_layoutreturn(d_data->inode, task)) {
+		nfs4_sequence_done(task, &d_data->res.seq_res);
+		return;
+	}
+
+	lo = d_data->args.lr_args ? d_data->args.lr_args->layout : NULL;
+	if (lo && !pnfs_layout_is_valid(lo)) {
+		d_data->args.lr_args = NULL;
+		d_data->res.lr_res = NULL;
+	}
+
+	nfs4_setup_sequence(d_data->res.server->nfs_client,
+			&d_data->args.seq_args,
+			&d_data->res.seq_res,
+			task);
+}
+
+static const struct rpc_call_ops nfs4_delegreturn_ops = {
+	.rpc_call_prepare = nfs4_delegreturn_prepare,
+	.rpc_call_done = nfs4_delegreturn_done,
+	.rpc_release = nfs4_delegreturn_release,
+};
+
+static int _nfs4_proc_delegreturn(struct inode *inode, const struct cred *cred, const nfs4_stateid *stateid, int issync)
+{
+	struct nfs4_delegreturndata *data;
+	struct nfs_server *server = NFS_SERVER(inode);
+	struct rpc_task *task;
+	struct rpc_message msg = {
+		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_DELEGRETURN],
+		.rpc_cred = cred,
+	};
+	struct rpc_task_setup task_setup_data = {
+		.rpc_client = server->client,
+		.rpc_message = &msg,
+		.callback_ops = &nfs4_delegreturn_ops,
+		.flags = RPC_TASK_ASYNC | RPC_TASK_TIMEOUT,
+	};
+	int status = 0;
+
+	data = kzalloc(sizeof(*data), GFP_NOFS);
+	if (data == NULL)
+		return -ENOMEM;
+
+	nfs4_state_protect(server->nfs_client,
+			NFS_SP4_MACH_CRED_CLEANUP,
+			&task_setup_data.rpc_client, &msg);
+
+	data->args.fhandle = &data->fh;
+	data->args.stateid = &data->stateid;
+	nfs4_bitmask_set(data->args.bitmask_store,
+			 server->cache_consistency_bitmask, inode, server,
+			 NULL);
+	data->args.bitmask = data->args.bitmask_store;
+	nfs_copy_fh(&data->fh, NFS_FH(inode));
+	nfs4_stateid_copy(&data->stateid, stateid);
+	data->res.fattr = &data->fattr;
+	data->res.server = server;
+	data->res.lr_ret = -NFS4ERR_NOMATCHING_LAYOUT;
+	data->lr.arg.ld_private = &data->lr.ld_private;
+	nfs_fattr_init(data->res.fattr);
+	data->timestamp = jiffies;
+	data->rpc_status = 0;
+	data->inode = nfs_igrab_and_active(inode);
+	if (data->inode || issync) {
+		data->lr.roc = pnfs_roc(inode, &data->lr.arg, &data->lr.res,
+					cred);
+		if (data->lr.roc) {
+			data->args.lr_args = &data->lr.arg;
+			data->res.lr_res = &data->lr.res;
+		}
+	}
+
+	if (!data->inode)
+		nfs4_init_sequence(&data->args.seq_args, &data->res.seq_res, 1,
+				   1);
+	else
+		nfs4_init_sequence(&data->args.seq_args, &data->res.seq_res, 1,
+				   0);
+	task_setup_data.callback_data = data;
+	msg.rpc_argp = &data->args;
+	msg.rpc_resp = &data->res;
+	task = rpc_run_task(&task_setup_data);
+	if (IS_ERR(task))
+		return PTR_ERR(task);
+	if (!issync)
+		goto out;
+	status = rpc_wait_for_completion_task(task);
+	if (status != 0)
+		goto out;
+	status = data->rpc_status;
+out:
+	rpc_put_task(task);
+	return status;
+}
+
+int nfs4_proc_delegreturn(struct inode *inode, const struct cred *cred, const nfs4_stateid *stateid, int issync)
+{
+	struct nfs_server *server = NFS_SERVER(inode);
+	struct nfs4_exception exception = { };
+	int err;
+	do {
+		err = _nfs4_proc_delegreturn(inode, cred, stateid, issync);
+		trace_nfs4_delegreturn(inode, stateid, err);
+		switch (err) {
+			case -NFS4ERR_STALE_STATEID:
+			case -NFS4ERR_EXPIRED:
+			case 0:
+				return 0;
+		}
+		err = nfs4_handle_exception(server, err, &exception);
+	} while (exception.retry);
+	return err;
+}
+
+static int _nfs4_proc_getlk(struct nfs4_state *state, int cmd, struct file_lock *request)
+{
+	struct inode *inode = state->inode;
+	struct nfs_server *server = NFS_SERVER(inode);
+	struct nfs_client *clp = server->nfs_client;
+	struct nfs_lockt_args arg = {
+		.fh = NFS_FH(inode),
+		.fl = request,
+	};
+	struct nfs_lockt_res res = {
+		.denied = request,
+	};
+	struct rpc_message msg = {
+		.rpc_proc	= &nfs4_procedures[NFSPROC4_CLNT_LOCKT],
+		.rpc_argp	= &arg,
+		.rpc_resp	= &res,
+		.rpc_cred	= state->owner->so_cred,
+	};
+	struct nfs4_lock_state *lsp;
+	int status;
+
+	arg.lock_owner.clientid = clp->cl_clientid;
+	status = nfs4_set_lock_state(state, request);
+	if (status != 0)
+		goto out;
+	lsp = request->fl_u.nfs4_fl.owner;
+	arg.lock_owner.id = lsp->ls_seqid.owner_id;
+	arg.lock_owner.s_dev = server->s_dev;
+	status = nfs4_call_sync(server->client, server, &msg, &arg.seq_args, &res.seq_res, 1);
+	switch (status) {
+		case 0:
+			request->fl_type = F_UNLCK;
+			break;
+		case -NFS4ERR_DENIED:
+			status = 0;
+	}
+	request->fl_ops->fl_release_private(request);
+	request->fl_ops = NULL;
+out:
+	return status;
+}
+
+static int nfs4_proc_getlk(struct nfs4_state *state, int cmd, struct file_lock *request)
+{
+	struct nfs4_exception exception = {
+		.interruptible = true,
+	};
+	int err;
+
+	do {
+		err = _nfs4_proc_getlk(state, cmd, request);
+		trace_nfs4_get_lock(request, state, cmd, err);
+		err = nfs4_handle_exception(NFS_SERVER(state->inode), err,
+				&exception);
+	} while (exception.retry);
+	return err;
+}
+
+/*
+ * Update the seqid of a lock stateid after receiving
+ * NFS4ERR_OLD_STATEID
+ */
+static bool nfs4_refresh_lock_old_stateid(nfs4_stateid *dst,
+		struct nfs4_lock_state *lsp)
+{
+	struct nfs4_state *state = lsp->ls_state;
+	bool ret = false;
+
+	spin_lock(&state->state_lock);
+	if (!nfs4_stateid_match_other(dst, &lsp->ls_stateid))
+		goto out;
+	if (!nfs4_stateid_is_newer(&lsp->ls_stateid, dst))
+		nfs4_stateid_seqid_inc(dst);
+	else
+		dst->seqid = lsp->ls_stateid.seqid;
+	ret = true;
+out:
+	spin_unlock(&state->state_lock);
+	return ret;
+}
+
+static bool nfs4_sync_lock_stateid(nfs4_stateid *dst,
+		struct nfs4_lock_state *lsp)
+{
+	struct nfs4_state *state = lsp->ls_state;
+	bool ret;
+
+	spin_lock(&state->state_lock);
+	ret = !nfs4_stateid_match_other(dst, &lsp->ls_stateid);
+	nfs4_stateid_copy(dst, &lsp->ls_stateid);
+	spin_unlock(&state->state_lock);
+	return ret;
+}
+
+struct nfs4_unlockdata {
+	struct nfs_locku_args arg;
+	struct nfs_locku_res res;
+	struct nfs4_lock_state *lsp;
+	struct nfs_open_context *ctx;
+	struct nfs_lock_context *l_ctx;
+	struct file_lock fl;
+	struct nfs_server *server;
+	unsigned long timestamp;
+};
+
+static struct nfs4_unlockdata *nfs4_alloc_unlockdata(struct file_lock *fl,
+		struct nfs_open_context *ctx,
+		struct nfs4_lock_state *lsp,
+		struct nfs_seqid *seqid)
+{
+	struct nfs4_unlockdata *p;
+	struct nfs4_state *state = lsp->ls_state;
+	struct inode *inode = state->inode;
+
+	p = kzalloc(sizeof(*p), GFP_NOFS);
+	if (p == NULL)
+		return NULL;
+	p->arg.fh = NFS_FH(inode);
+	p->arg.fl = &p->fl;
+	p->arg.seqid = seqid;
+	p->res.seqid = seqid;
+	p->lsp = lsp;
+	/* Ensure we don't close file until we're done freeing locks! */
+	p->ctx = get_nfs_open_context(ctx);
+	p->l_ctx = nfs_get_lock_context(ctx);
+	locks_init_lock(&p->fl);
+	locks_copy_lock(&p->fl, fl);
+	p->server = NFS_SERVER(inode);
+	spin_lock(&state->state_lock);
+	nfs4_stateid_copy(&p->arg.stateid, &lsp->ls_stateid);
+	spin_unlock(&state->state_lock);
+	return p;
+}
+
+static void nfs4_locku_release_calldata(void *data)
+{
+	struct nfs4_unlockdata *calldata = data;
+	nfs_free_seqid(calldata->arg.seqid);
+	nfs4_put_lock_state(calldata->lsp);
+	nfs_put_lock_context(calldata->l_ctx);
+	put_nfs_open_context(calldata->ctx);
+	kfree(calldata);
+}
+
+static void nfs4_locku_done(struct rpc_task *task, void *data)
+{
+	struct nfs4_unlockdata *calldata = data;
+	struct nfs4_exception exception = {
+		.inode = calldata->lsp->ls_state->inode,
+		.stateid = &calldata->arg.stateid,
+	};
+
+	if (!nfs4_sequence_done(task, &calldata->res.seq_res))
+		return;
+	switch (task->tk_status) {
+		case 0:
+			renew_lease(calldata->server, calldata->timestamp);
+			locks_lock_inode_wait(calldata->lsp->ls_state->inode, &calldata->fl);
+			if (nfs4_update_lock_stateid(calldata->lsp,
+					&calldata->res.stateid))
+				break;
+			fallthrough;
+		case -NFS4ERR_ADMIN_REVOKED:
+		case -NFS4ERR_EXPIRED:
+			nfs4_free_revoked_stateid(calldata->server,
+					&calldata->arg.stateid,
+					task->tk_msg.rpc_cred);
+			fallthrough;
+		case -NFS4ERR_BAD_STATEID:
+		case -NFS4ERR_STALE_STATEID:
+			if (nfs4_sync_lock_stateid(&calldata->arg.stateid,
+						calldata->lsp))
+				rpc_restart_call_prepare(task);
+			break;
+		case -NFS4ERR_OLD_STATEID:
+			if (nfs4_refresh_lock_old_stateid(&calldata->arg.stateid,
+						calldata->lsp))
+				rpc_restart_call_prepare(task);
+			break;
+		default:
+			task->tk_status = nfs4_async_handle_exception(task,
+					calldata->server, task->tk_status,
+					&exception);
+			if (exception.retry)
+				rpc_restart_call_prepare(task);
+	}
+	nfs_release_seqid(calldata->arg.seqid);
+}
+
+static void nfs4_locku_prepare(struct rpc_task *task, void *data)
+{
+	struct nfs4_unlockdata *calldata = data;
+
+	if (test_bit(NFS_CONTEXT_UNLOCK, &calldata->l_ctx->open_context->flags) &&
+		nfs_async_iocounter_wait(task, calldata->l_ctx))
+		return;
+
+	if (nfs_wait_on_sequence(calldata->arg.seqid, task) != 0)
+		goto out_wait;
+	if (test_bit(NFS_LOCK_INITIALIZED, &calldata->lsp->ls_flags) == 0) {
+		/* Note: exit _without_ running nfs4_locku_done */
+		goto out_no_action;
+	}
+	calldata->timestamp = jiffies;
+	if (nfs4_setup_sequence(calldata->server->nfs_client,
+				&calldata->arg.seq_args,
+				&calldata->res.seq_res,
+				task) != 0)
+		nfs_release_seqid(calldata->arg.seqid);
+	return;
+out_no_action:
+	task->tk_action = NULL;
+out_wait:
+	nfs4_sequence_done(task, &calldata->res.seq_res);
+}
+
+static const struct rpc_call_ops nfs4_locku_ops = {
+	.rpc_call_prepare = nfs4_locku_prepare,
+	.rpc_call_done = nfs4_locku_done,
+	.rpc_release = nfs4_locku_release_calldata,
+};
+
+static struct rpc_task *nfs4_do_unlck(struct file_lock *fl,
+		struct nfs_open_context *ctx,
+		struct nfs4_lock_state *lsp,
+		struct nfs_seqid *seqid)
+{
+	struct nfs4_unlockdata *data;
+	struct rpc_message msg = {
+		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_LOCKU],
+		.rpc_cred = ctx->cred,
+	};
+	struct rpc_task_setup task_setup_data = {
+		.rpc_client = NFS_CLIENT(lsp->ls_state->inode),
+		.rpc_message = &msg,
+		.callback_ops = &nfs4_locku_ops,
+		.workqueue = nfsiod_workqueue,
+		.flags = RPC_TASK_ASYNC,
+	};
+
+	nfs4_state_protect(NFS_SERVER(lsp->ls_state->inode)->nfs_client,
+		NFS_SP4_MACH_CRED_CLEANUP, &task_setup_data.rpc_client, &msg);
+
+	/* Ensure this is an unlock - when canceling a lock, the
+	 * canceled lock is passed in, and it won't be an unlock.
+	 */
+	fl->fl_type = F_UNLCK;
+	if (fl->fl_flags & FL_CLOSE)
+		set_bit(NFS_CONTEXT_UNLOCK, &ctx->flags);
+
+	data = nfs4_alloc_unlockdata(fl, ctx, lsp, seqid);
+	if (data == NULL) {
+		nfs_free_seqid(seqid);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	nfs4_init_sequence(&data->arg.seq_args, &data->res.seq_res, 1, 0);
+	msg.rpc_argp = &data->arg;
+	msg.rpc_resp = &data->res;
+	task_setup_data.callback_data = data;
+	return rpc_run_task(&task_setup_data);
+}
+
+static int nfs4_proc_unlck(struct nfs4_state *state, int cmd, struct file_lock *request)
+{
+	struct inode *inode = state->inode;
+	struct nfs4_state_owner *sp = state->owner;
+	struct nfs_inode *nfsi = NFS_I(inode);
+	struct nfs_seqid *seqid;
+	struct nfs4_lock_state *lsp;
+	struct rpc_task *task;
+	struct nfs_seqid *(*alloc_seqid)(struct nfs_seqid_counter *, gfp_t);
+	int status = 0;
+	unsigned char fl_flags = request->fl_flags;
+
+	status = nfs4_set_lock_state(state, request);
+	/* Unlock _before_ we do the RPC call */
+	request->fl_flags |= FL_EXISTS;
+	/* Exclude nfs_delegation_claim_locks() */
+	mutex_lock(&sp->so_delegreturn_mutex);
+	/* Exclude nfs4_reclaim_open_stateid() - note nesting! */
+	down_read(&nfsi->rwsem);
+	if (locks_lock_inode_wait(inode, request) == -ENOENT) {
+		up_read(&nfsi->rwsem);
+		mutex_unlock(&sp->so_delegreturn_mutex);
+		goto out;
+	}
+	up_read(&nfsi->rwsem);
+	mutex_unlock(&sp->so_delegreturn_mutex);
+	if (status != 0)
+		goto out;
+	/* Is this a delegated lock? */
+	lsp = request->fl_u.nfs4_fl.owner;
+	if (test_bit(NFS_LOCK_INITIALIZED, &lsp->ls_flags) == 0)
+		goto out;
+	alloc_seqid = NFS_SERVER(inode)->nfs_client->cl_mvops->alloc_seqid;
+	seqid = alloc_seqid(&lsp->ls_seqid, GFP_KERNEL);
+	status = -ENOMEM;
+	if (IS_ERR(seqid))
+		goto out;
+	task = nfs4_do_unlck(request, nfs_file_open_context(request->fl_file), lsp, seqid);
+	status = PTR_ERR(task);
+	if (IS_ERR(task))
+		goto out;
+	status = rpc_wait_for_completion_task(task);
+	rpc_put_task(task);
+out:
+	request->fl_flags = fl_flags;
+	trace_nfs4_unlock(request, state, F_SETLK, status);
+	return status;
+}
+
+struct nfs4_lockdata {
+	struct nfs_lock_args arg;
+	struct nfs_lock_res res;
+	struct nfs4_lock_state *lsp;
+	struct nfs_open_context *ctx;
+	struct file_lock fl;
+	unsigned long timestamp;
+	int rpc_status;
+	int cancelled;
+	struct nfs_server *server;
+};
+
+static struct nfs4_lockdata *nfs4_alloc_lockdata(struct file_lock *fl,
+		struct nfs_open_context *ctx, struct nfs4_lock_state *lsp,
+		gfp_t gfp_mask)
+{
+	struct nfs4_lockdata *p;
+	struct inode *inode = lsp->ls_state->inode;
+	struct nfs_server *server = NFS_SERVER(inode);
+	struct nfs_seqid *(*alloc_seqid)(struct nfs_seqid_counter *, gfp_t);
+
+	p = kzalloc(sizeof(*p), gfp_mask);
+	if (p == NULL)
+		return NULL;
+
+	p->arg.fh = NFS_FH(inode);
+	p->arg.fl = &p->fl;
+	p->arg.open_seqid = nfs_alloc_seqid(&lsp->ls_state->owner->so_seqid, gfp_mask);
+	if (IS_ERR(p->arg.open_seqid))
+		goto out_free;
+	alloc_seqid = server->nfs_client->cl_mvops->alloc_seqid;
+	p->arg.lock_seqid = alloc_seqid(&lsp->ls_seqid, gfp_mask);
+	if (IS_ERR(p->arg.lock_seqid))
+		goto out_free_seqid;
+	p->arg.lock_owner.clientid = server->nfs_client->cl_clientid;
+	p->arg.lock_owner.id = lsp->ls_seqid.owner_id;
+	p->arg.lock_owner.s_dev = server->s_dev;
+	p->res.lock_seqid = p->arg.lock_seqid;
+	p->lsp = lsp;
+	p->server = server;
+	p->ctx = get_nfs_open_context(ctx);
+	locks_init_lock(&p->fl);
+	locks_copy_lock(&p->fl, fl);
+	return p;
+out_free_seqid:
+	nfs_free_seqid(p->arg.open_seqid);
+out_free:
+	kfree(p);
+	return NULL;
+}
+
+static void nfs4_lock_prepare(struct rpc_task *task, void *calldata)
+{
+	struct nfs4_lockdata *data = calldata;
+	struct nfs4_state *state = data->lsp->ls_state;
+
+	dprintk("%s: begin!\n", __func__);
+	if (nfs_wait_on_sequence(data->arg.lock_seqid, task) != 0)
+		goto out_wait;
+	/* Do we need to do an open_to_lock_owner? */
+	if (!test_bit(NFS_LOCK_INITIALIZED, &data->lsp->ls_flags)) {
+		if (nfs_wait_on_sequence(data->arg.open_seqid, task) != 0) {
+			goto out_release_lock_seqid;
+		}
+		nfs4_stateid_copy(&data->arg.open_stateid,
+				&state->open_stateid);
+		data->arg.new_lock_owner = 1;
+		data->res.open_seqid = data->arg.open_seqid;
+	} else {
+		data->arg.new_lock_owner = 0;
+		nfs4_stateid_copy(&data->arg.lock_stateid,
+				&data->lsp->ls_stateid);
+	}
+	if (!nfs4_valid_open_stateid(state)) {
+		data->rpc_status = -EBADF;
+		task->tk_action = NULL;
+		goto out_release_open_seqid;
+	}
+	data->timestamp = jiffies;
+	if (nfs4_setup_sequence(data->server->nfs_client,
+				&data->arg.seq_args,
+				&data->res.seq_res,
+				task) == 0)
+		return;
+out_release_open_seqid:
+	nfs_release_seqid(data->arg.open_seqid);
+out_release_lock_seqid:
+	nfs_release_seqid(data->arg.lock_seqid);
+out_wait:
+	nfs4_sequence_done(task, &data->res.seq_res);
+	dprintk("%s: done!, ret = %d\n", __func__, data->rpc_status);
+}
+
+static void nfs4_lock_done(struct rpc_task *task, void *calldata)
+{
+	struct nfs4_lockdata *data = calldata;
+	struct nfs4_lock_state *lsp = data->lsp;
+	struct nfs_server *server = NFS_SERVER(d_inode(data->ctx->dentry));
+
+	dprintk("%s: begin!\n", __func__);
+
+	if (!nfs4_sequence_done(task, &data->res.seq_res))
+		return;
+
+	data->rpc_status = task->tk_status;
+	switch (task->tk_status) {
+	case 0:
+		renew_lease(server, data->timestamp);
+		if (data->arg.new_lock && !data->cancelled) {
+			data->fl.fl_flags &= ~(FL_SLEEP | FL_ACCESS);
+			if (locks_lock_inode_wait(lsp->ls_state->inode, &data->fl) < 0)
+				goto out_restart;
+		}
+		if (data->arg.new_lock_owner != 0) {
+			nfs_confirm_seqid(&lsp->ls_seqid, 0);
+			nfs4_stateid_copy(&lsp->ls_stateid, &data->res.stateid);
+			set_bit(NFS_LOCK_INITIALIZED, &lsp->ls_flags);
+		} else if (!nfs4_update_lock_stateid(lsp, &data->res.stateid))
+			goto out_restart;
+		break;
+	case -NFS4ERR_OLD_STATEID:
+		if (data->arg.new_lock_owner != 0 &&
+			nfs4_refresh_open_old_stateid(&data->arg.open_stateid,
+					lsp->ls_state))
+			goto out_restart;
+		if (nfs4_refresh_lock_old_stateid(&data->arg.lock_stateid, lsp))
+			goto out_restart;
+		fallthrough;
+	case -NFS4ERR_BAD_STATEID:
+	case -NFS4ERR_STALE_STATEID:
+	case -NFS4ERR_EXPIRED:
+		if (data->arg.new_lock_owner != 0) {
+			if (!nfs4_stateid_match(&data->arg.open_stateid,
+						&lsp->ls_state->open_stateid))
+				goto out_restart;
+			else if (nfs4_async_handle_error(task, server, lsp->ls_state, NULL) == -EAGAIN)
+				goto out_restart;
+		} else if (!nfs4_stateid_match(&data->arg.lock_stateid,
+						&lsp->ls_stateid))
+				goto out_restart;
+	}
+out_done:
+	dprintk("%s: done, ret = %d!\n", __func__, data->rpc_status);
+	return;
+out_restart:
+	if (!data->cancelled)
+		rpc_restart_call_prepare(task);
+	goto out_done;
+}
+
+static void nfs4_lock_release(void *calldata)
+{
+	struct nfs4_lockdata *data = calldata;
+
+	dprintk("%s: begin!\n", __func__);
+	nfs_free_seqid(data->arg.open_seqid);
+	if (data->cancelled && data->rpc_status == 0) {
+		struct rpc_task *task;
+		task = nfs4_do_unlck(&data->fl, data->ctx, data->lsp,
+				data->arg.lock_seqid);
+		if (!IS_ERR(task))
+			rpc_put_task_async(task);
+		dprintk("%s: cancelling lock!\n", __func__);
+	} else
+		nfs_free_seqid(data->arg.lock_seqid);
+	nfs4_put_lock_state(data->lsp);
+	put_nfs_open_context(data->ctx);
+	kfree(data);
+	dprintk("%s: done!\n", __func__);
+}
+
+static const struct rpc_call_ops nfs4_lock_ops = {
+	.rpc_call_prepare = nfs4_lock_prepare,
+	.rpc_call_done = nfs4_lock_done,
+	.rpc_release = nfs4_lock_release,
+};
+
+static void nfs4_handle_setlk_error(struct nfs_server *server, struct nfs4_lock_state *lsp, int new_lock_owner, int error)
+{
+	switch (error) {
+	case -NFS4ERR_ADMIN_REVOKED:
+	case -NFS4ERR_EXPIRED:
+	case -NFS4ERR_BAD_STATEID:
+		lsp->ls_seqid.flags &= ~NFS_SEQID_CONFIRMED;
+		if (new_lock_owner != 0 ||
+		   test_bit(NFS_LOCK_INITIALIZED, &lsp->ls_flags) != 0)
+			nfs4_schedule_stateid_recovery(server, lsp->ls_state);
+		break;
+	case -NFS4ERR_STALE_STATEID:
+		lsp->ls_seqid.flags &= ~NFS_SEQID_CONFIRMED;
+		nfs4_schedule_lease_recovery(server->nfs_client);
+	}
+}
+
+static int _nfs4_do_setlk(struct nfs4_state *state, int cmd, struct file_lock *fl, int recovery_type)
+{
+	struct nfs4_lockdata *data;
+	struct rpc_task *task;
+	struct rpc_message msg = {
+		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_LOCK],
+		.rpc_cred = state->owner->so_cred,
+	};
+	struct rpc_task_setup task_setup_data = {
+		.rpc_client = NFS_CLIENT(state->inode),
+		.rpc_message = &msg,
+		.callback_ops = &nfs4_lock_ops,
+		.workqueue = nfsiod_workqueue,
+		.flags = RPC_TASK_ASYNC | RPC_TASK_CRED_NOREF,
+	};
+	int ret;
+
+	dprintk("%s: begin!\n", __func__);
+	data = nfs4_alloc_lockdata(fl, nfs_file_open_context(fl->fl_file),
+			fl->fl_u.nfs4_fl.owner,
+			recovery_type == NFS_LOCK_NEW ? GFP_KERNEL : GFP_NOFS);
+	if (data == NULL)
+		return -ENOMEM;
+	if (IS_SETLKW(cmd))
+		data->arg.block = 1;
+	nfs4_init_sequence(&data->arg.seq_args, &data->res.seq_res, 1,
+				recovery_type > NFS_LOCK_NEW);
+	msg.rpc_argp = &data->arg;
+	msg.rpc_resp = &data->res;
+	task_setup_data.callback_data = data;
+	if (recovery_type > NFS_LOCK_NEW) {
+		if (recovery_type == NFS_LOCK_RECLAIM)
+			data->arg.reclaim = NFS_LOCK_RECLAIM;
+	} else
+		data->arg.new_lock = 1;
+	task = rpc_run_task(&task_setup_data);
+	if (IS_ERR(task))
+		return PTR_ERR(task);
+	ret = rpc_wait_for_completion_task(task);
+	if (ret == 0) {
+		ret = data->rpc_status;
+		if (ret)
+			nfs4_handle_setlk_error(data->server, data->lsp,
+					data->arg.new_lock_owner, ret);
+	} else
+		data->cancelled = true;
+	trace_nfs4_set_lock(fl, state, &data->res.stateid, cmd, ret);
+	rpc_put_task(task);
+	dprintk("%s: done, ret = %d!\n", __func__, ret);
+	return ret;
+}
+
+static int nfs4_lock_reclaim(struct nfs4_state *state, struct file_lock *request)
+{
+	struct nfs_server *server = NFS_SERVER(state->inode);
+	struct nfs4_exception exception = {
+		.inode = state->inode,
+	};
+	int err;
+
+	do {
+		/* Cache the lock if possible... */
+		if (test_bit(NFS_DELEGATED_STATE, &state->flags) != 0)
+			return 0;
+		err = _nfs4_do_setlk(state, F_SETLK, request, NFS_LOCK_RECLAIM);
+		if (err != -NFS4ERR_DELAY)
+			break;
+		nfs4_handle_exception(server, err, &exception);
+	} while (exception.retry);
+	return err;
+}
+
+static int nfs4_lock_expired(struct nfs4_state *state, struct file_lock *request)
+{
+	struct nfs_server *server = NFS_SERVER(state->inode);
+	struct nfs4_exception exception = {
+		.inode = state->inode,
+	};
+	int err;
+
+	err = nfs4_set_lock_state(state, request);
+	if (err != 0)
+		return err;
+	if (!recover_lost_locks) {
+		set_bit(NFS_LOCK_LOST, &request->fl_u.nfs4_fl.owner->ls_flags);
+		return 0;
+	}
+	do {
+		if (test_bit(NFS_DELEGATED_STATE, &state->flags) != 0)
+			return 0;
+		err = _nfs4_do_setlk(state, F_SETLK, request, NFS_LOCK_EXPIRED);
+		switch (err) {
+		default:
+			goto out;
+		case -NFS4ERR_GRACE:
+		case -NFS4ERR_DELAY:
+			nfs4_handle_exception(server, err, &exception);
+			err = 0;
+		}
+	} while (exception.retry);
+out:
+	return err;
+}
+
+#if defined(CONFIG_NFS_V4_1)
+static int nfs41_lock_expired(struct nfs4_state *state, struct file_lock *request)
+{
+	struct nfs4_lock_state *lsp;
+	int status;
+
+	status = nfs4_set_lock_state(state, request);
+	if (status != 0)
+		return status;
+	lsp = request->fl_u.nfs4_fl.owner;
+	if (test_bit(NFS_LOCK_INITIALIZED, &lsp->ls_flags) ||
+	    test_bit(NFS_LOCK_LOST, &lsp->ls_flags))
+		return 0;
+	return nfs4_lock_expired(state, request);
+}
+#endif
+
+static int _nfs4_proc_setlk(struct nfs4_state *state, int cmd, struct file_lock *request)
+{
+	struct nfs_inode *nfsi = NFS_I(state->inode);
+	struct nfs4_state_owner *sp = state->owner;
+	unsigned char fl_flags = request->fl_flags;
+	int status;
+
+	request->fl_flags |= FL_ACCESS;
+	status = locks_lock_inode_wait(state->inode, request);
+	if (status < 0)
+		goto out;
+	mutex_lock(&sp->so_delegreturn_mutex);
+	down_read(&nfsi->rwsem);
+	if (test_bit(NFS_DELEGATED_STATE, &state->flags)) {
+		/* Yes: cache locks! */
+		/* ...but avoid races with delegation recall... */
+		request->fl_flags = fl_flags & ~FL_SLEEP;
+		status = locks_lock_inode_wait(state->inode, request);
+		up_read(&nfsi->rwsem);
+		mutex_unlock(&sp->so_delegreturn_mutex);
+		goto out;
+	}
+	up_read(&nfsi->rwsem);
+	mutex_unlock(&sp->so_delegreturn_mutex);
+	status = _nfs4_do_setlk(state, cmd, request, NFS_LOCK_NEW);
+out:
+	request->fl_flags = fl_flags;
+	return status;
+}
+
+static int nfs4_proc_setlk(struct nfs4_state *state, int cmd, struct file_lock *request)
+{
+	struct nfs4_exception exception = {
+		.state = state,
+		.inode = state->inode,
+		.interruptible = true,
+	};
+	int err;
+
+	do {
+		err = _nfs4_proc_setlk(state, cmd, request);
+		if (err == -NFS4ERR_DENIED)
+			err = -EAGAIN;
+		err = nfs4_handle_exception(NFS_SERVER(state->inode),
+				err, &exception);
+	} while (exception.retry);
+	return err;
+}
+
+#define NFS4_LOCK_MINTIMEOUT (1 * HZ)
+#define NFS4_LOCK_MAXTIMEOUT (30 * HZ)
+
+static int
+nfs4_retry_setlk_simple(struct nfs4_state *state, int cmd,
+			struct file_lock *request)
+{
+	int		status = -ERESTARTSYS;
+	unsigned long	timeout = NFS4_LOCK_MINTIMEOUT;
+
+	while(!signalled()) {
+		status = nfs4_proc_setlk(state, cmd, request);
+		if ((status != -EAGAIN) || IS_SETLK(cmd))
+			break;
+		freezable_schedule_timeout_interruptible(timeout);
+		timeout *= 2;
+		timeout = min_t(unsigned long, NFS4_LOCK_MAXTIMEOUT, timeout);
+		status = -ERESTARTSYS;
+	}
+	return status;
+}
+
+#ifdef CONFIG_NFS_V4_1
+struct nfs4_lock_waiter {
+	struct task_struct	*task;
+	struct inode		*inode;
+	struct nfs_lowner	*owner;
+};
+
+static int
+nfs4_wake_lock_waiter(wait_queue_entry_t *wait, unsigned int mode, int flags, void *key)
+{
+	int ret;
+	struct nfs4_lock_waiter	*waiter	= wait->private;
+
+	/* NULL key means to wake up everyone */
+	if (key) {
+		struct cb_notify_lock_args	*cbnl = key;
+		struct nfs_lowner		*lowner = &cbnl->cbnl_owner,
+						*wowner = waiter->owner;
+
+		/* Only wake if the callback was for the same owner. */
+		if (lowner->id != wowner->id || lowner->s_dev != wowner->s_dev)
+			return 0;
+
+		/* Make sure it's for the right inode */
+		if (nfs_compare_fh(NFS_FH(waiter->inode), &cbnl->cbnl_fh))
+			return 0;
+	}
+
+	/* override "private" so we can use default_wake_function */
+	wait->private = waiter->task;
+	ret = woken_wake_function(wait, mode, flags, key);
+	if (ret)
+		list_del_init(&wait->entry);
+	wait->private = waiter;
+	return ret;
+}
+
+static int
+nfs4_retry_setlk(struct nfs4_state *state, int cmd, struct file_lock *request)
+{
+	int status = -ERESTARTSYS;
+	struct nfs4_lock_state *lsp = request->fl_u.nfs4_fl.owner;
+	struct nfs_server *server = NFS_SERVER(state->inode);
+	struct nfs_client *clp = server->nfs_client;
+	wait_queue_head_t *q = &clp->cl_lock_waitq;
+	struct nfs_lowner owner = { .clientid = clp->cl_clientid,
+				    .id = lsp->ls_seqid.owner_id,
+				    .s_dev = server->s_dev };
+	struct nfs4_lock_waiter waiter = { .task  = current,
+					   .inode = state->inode,
+					   .owner = &owner};
+	wait_queue_entry_t wait;
+
+	/* Don't bother with waitqueue if we don't expect a callback */
+	if (!test_bit(NFS_STATE_MAY_NOTIFY_LOCK, &state->flags))
+		return nfs4_retry_setlk_simple(state, cmd, request);
+
+	init_wait(&wait);
+	wait.private = &waiter;
+	wait.func = nfs4_wake_lock_waiter;
+
+	while(!signalled()) {
+		add_wait_queue(q, &wait);
+		status = nfs4_proc_setlk(state, cmd, request);
+		if ((status != -EAGAIN) || IS_SETLK(cmd)) {
+			finish_wait(q, &wait);
+			break;
+		}
+
+		status = -ERESTARTSYS;
+		freezer_do_not_count();
+		wait_woken(&wait, TASK_INTERRUPTIBLE, NFS4_LOCK_MAXTIMEOUT);
+		freezer_count();
+		finish_wait(q, &wait);
+	}
+
+	return status;
+}
+#else /* !CONFIG_NFS_V4_1 */
+static inline int
+nfs4_retry_setlk(struct nfs4_state *state, int cmd, struct file_lock *request)
+{
+	return nfs4_retry_setlk_simple(state, cmd, request);
+}
+#endif
+
+static int
+nfs4_proc_lock(struct file *filp, int cmd, struct file_lock *request)
+{
+	struct nfs_open_context *ctx;
+	struct nfs4_state *state;
+	int status;
+
+	/* verify open state */
+	ctx = nfs_file_open_context(filp);
+	state = ctx->state;
+
+	if (IS_GETLK(cmd)) {
+		if (state != NULL)
+			return nfs4_proc_getlk(state, F_GETLK, request);
+		return 0;
+	}
+
+	if (!(IS_SETLK(cmd) || IS_SETLKW(cmd)))
+		return -EINVAL;
+
+	if (request->fl_type == F_UNLCK) {
+		if (state != NULL)
+			return nfs4_proc_unlck(state, cmd, request);
+		return 0;
+	}
+
+	if (state == NULL)
+		return -ENOLCK;
+
+	if ((request->fl_flags & FL_POSIX) &&
+	    !test_bit(NFS_STATE_POSIX_LOCKS, &state->flags))
+		return -ENOLCK;
+
+	/*
+	 * Don't rely on the VFS having checked the file open mode,
+	 * since it won't do this for flock() locks.
+	 */
+	switch (request->fl_type) {
+	case F_RDLCK:
+		if (!(filp->f_mode & FMODE_READ))
+			return -EBADF;
+		break;
+	case F_WRLCK:
+		if (!(filp->f_mode & FMODE_WRITE))
+			return -EBADF;
+	}
+
+	status = nfs4_set_lock_state(state, request);
+	if (status != 0)
+		return status;
+
+	return nfs4_retry_setlk(state, cmd, request);
+}
+
+int nfs4_lock_delegation_recall(struct file_lock *fl, struct nfs4_state *state, const nfs4_stateid *stateid)
+{
+	struct nfs_server *server = NFS_SERVER(state->inode);
+	int err;
+
+	err = nfs4_set_lock_state(state, fl);
+	if (err != 0)
+		return err;
+	do {
+		err = _nfs4_do_setlk(state, F_SETLK, fl, NFS_LOCK_NEW);
+		if (err != -NFS4ERR_DELAY)
+			break;
+		ssleep(1);
+	} while (err == -NFS4ERR_DELAY);
+	return nfs4_handle_delegation_recall_error(server, state, stateid, fl, err);
+}
+
+struct nfs_release_lockowner_data {
+	struct nfs4_lock_state *lsp;
+	struct nfs_server *server;
+	struct nfs_release_lockowner_args args;
+	struct nfs_release_lockowner_res res;
+	unsigned long timestamp;
+};
+
+static void nfs4_release_lockowner_prepare(struct rpc_task *task, void *calldata)
+{
+	struct nfs_release_lockowner_data *data = calldata;
+	struct nfs_server *server = data->server;
+	nfs4_setup_sequence(server->nfs_client, &data->args.seq_args,
+			   &data->res.seq_res, task);
+	data->args.lock_owner.clientid = server->nfs_client->cl_clientid;
+	data->timestamp = jiffies;
+}
+
+static void nfs4_release_lockowner_done(struct rpc_task *task, void *calldata)
+{
+	struct nfs_release_lockowner_data *data = calldata;
+	struct nfs_server *server = data->server;
+
+	nfs40_sequence_done(task, &data->res.seq_res);
+
+	switch (task->tk_status) {
+	case 0:
+		renew_lease(server, data->timestamp);
+		break;
+	case -NFS4ERR_STALE_CLIENTID:
+	case -NFS4ERR_EXPIRED:
+		nfs4_schedule_lease_recovery(server->nfs_client);
+		break;
+	case -NFS4ERR_LEASE_MOVED:
+	case -NFS4ERR_DELAY:
+		if (nfs4_async_handle_error(task, server,
+					    NULL, NULL) == -EAGAIN)
+			rpc_restart_call_prepare(task);
+	}
+}
+
+static void nfs4_release_lockowner_release(void *calldata)
+{
+	struct nfs_release_lockowner_data *data = calldata;
+	nfs4_free_lock_state(data->server, data->lsp);
+	kfree(calldata);
+}
+
+static const struct rpc_call_ops nfs4_release_lockowner_ops = {
+	.rpc_call_prepare = nfs4_release_lockowner_prepare,
+	.rpc_call_done = nfs4_release_lockowner_done,
+	.rpc_release = nfs4_release_lockowner_release,
+};
+
+static void
+nfs4_release_lockowner(struct nfs_server *server, struct nfs4_lock_state *lsp)
+{
+	struct nfs_release_lockowner_data *data;
+	struct rpc_message msg = {
+		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_RELEASE_LOCKOWNER],
+	};
+
+	if (server->nfs_client->cl_mvops->minor_version != 0)
+		return;
+
+	data = kmalloc(sizeof(*data), GFP_NOFS);
+	if (!data)
+		return;
+	data->lsp = lsp;
+	data->server = server;
+	data->args.lock_owner.clientid = server->nfs_client->cl_clientid;
+	data->args.lock_owner.id = lsp->ls_seqid.owner_id;
+	data->args.lock_owner.s_dev = server->s_dev;
+
+	msg.rpc_argp = &data->args;
+	msg.rpc_resp = &data->res;
+	nfs4_init_sequence(&data->args.seq_args, &data->res.seq_res, 0, 0);
+	rpc_call_async(server->client, &msg, 0, &nfs4_release_lockowner_ops, data);
+}
+
+#define XATTR_NAME_NFSV4_ACL "system.nfs4_acl"
+
+static int nfs4_xattr_set_nfs4_acl(const struct xattr_handler *handler,
+				   struct dentry *unused, struct inode *inode,
+				   const char *key, const void *buf,
+				   size_t buflen, int flags)
+{
+	return nfs4_proc_set_acl(inode, buf, buflen);
+}
+
+static int nfs4_xattr_get_nfs4_acl(const struct xattr_handler *handler,
+				   struct dentry *unused, struct inode *inode,
+				   const char *key, void *buf, size_t buflen)
+{
+	return nfs4_proc_get_acl(inode, buf, buflen);
+}
+
+static bool nfs4_xattr_list_nfs4_acl(struct dentry *dentry)
+{
+	return nfs4_server_supports_acls(NFS_SERVER(d_inode(dentry)));
+}
+
+#ifdef CONFIG_NFS_V4_SECURITY_LABEL
+
+static int nfs4_xattr_set_nfs4_label(const struct xattr_handler *handler,
+				     struct dentry *unused, struct inode *inode,
+				     const char *key, const void *buf,
+				     size_t buflen, int flags)
+{
+	if (security_ismaclabel(key))
+		return nfs4_set_security_label(inode, buf, buflen);
+
+	return -EOPNOTSUPP;
+}
+
+static int nfs4_xattr_get_nfs4_label(const struct xattr_handler *handler,
+				     struct dentry *unused, struct inode *inode,
+				     const char *key, void *buf, size_t buflen)
+{
+	if (security_ismaclabel(key))
+		return nfs4_get_security_label(inode, buf, buflen);
+	return -EOPNOTSUPP;
+}
+
+static ssize_t
+nfs4_listxattr_nfs4_label(struct inode *inode, char *list, size_t list_len)
+{
+	int len = 0;
+
+	if (nfs_server_capable(inode, NFS_CAP_SECURITY_LABEL)) {
+		len = security_inode_listsecurity(inode, list, list_len);
+		if (len >= 0 && list_len && len > list_len)
+			return -ERANGE;
+	}
+	return len;
+}
+
+static const struct xattr_handler nfs4_xattr_nfs4_label_handler = {
+	.prefix = XATTR_SECURITY_PREFIX,
+	.get	= nfs4_xattr_get_nfs4_label,
+	.set	= nfs4_xattr_set_nfs4_label,
+};
+
+#else
+
+static ssize_t
+nfs4_listxattr_nfs4_label(struct inode *inode, char *list, size_t list_len)
+{
+	return 0;
+}
+
+#endif
+
+#ifdef CONFIG_NFS_V4_2
+static int nfs4_xattr_set_nfs4_user(const struct xattr_handler *handler,
+				    struct dentry *unused, struct inode *inode,
+				    const char *key, const void *buf,
+				    size_t buflen, int flags)
+{
+	u32 mask;
+	int ret;
+
+	if (!nfs_server_capable(inode, NFS_CAP_XATTR))
+		return -EOPNOTSUPP;
+
+	/*
+	 * There is no mapping from the MAY_* flags to the NFS_ACCESS_XA*
+	 * flags right now. Handling of xattr operations use the normal
+	 * file read/write permissions.
+	 *
+	 * Just in case the server has other ideas (which RFC 8276 allows),
+	 * do a cached access check for the XA* flags to possibly avoid
+	 * doing an RPC and getting EACCES back.
+	 */
+	if (!nfs_access_get_cached(inode, current_cred(), &mask, true)) {
+		if (!(mask & NFS_ACCESS_XAWRITE))
+			return -EACCES;
+	}
+
+	if (buf == NULL) {
+		ret = nfs42_proc_removexattr(inode, key);
+		if (!ret)
+			nfs4_xattr_cache_remove(inode, key);
+	} else {
+		ret = nfs42_proc_setxattr(inode, key, buf, buflen, flags);
+		if (!ret)
+			nfs4_xattr_cache_add(inode, key, buf, NULL, buflen);
+	}
+
+	return ret;
+}
+
+static int nfs4_xattr_get_nfs4_user(const struct xattr_handler *handler,
+				    struct dentry *unused, struct inode *inode,
+				    const char *key, void *buf, size_t buflen)
+{
+	u32 mask;
+	ssize_t ret;
+
+	if (!nfs_server_capable(inode, NFS_CAP_XATTR))
+		return -EOPNOTSUPP;
+
+	if (!nfs_access_get_cached(inode, current_cred(), &mask, true)) {
+		if (!(mask & NFS_ACCESS_XAREAD))
+			return -EACCES;
+	}
+
+	ret = nfs_revalidate_inode(NFS_SERVER(inode), inode);
+	if (ret)
+		return ret;
+
+	ret = nfs4_xattr_cache_get(inode, key, buf, buflen);
+	if (ret >= 0 || (ret < 0 && ret != -ENOENT))
+		return ret;
+
+	ret = nfs42_proc_getxattr(inode, key, buf, buflen);
+
+	return ret;
+}
+
+static ssize_t
+nfs4_listxattr_nfs4_user(struct inode *inode, char *list, size_t list_len)
+{
+	u64 cookie;
+	bool eof;
+	ssize_t ret, size;
+	char *buf;
+	size_t buflen;
+	u32 mask;
+
+	if (!nfs_server_capable(inode, NFS_CAP_XATTR))
+		return 0;
+
+	if (!nfs_access_get_cached(inode, current_cred(), &mask, true)) {
+		if (!(mask & NFS_ACCESS_XALIST))
+			return 0;
+	}
+
+	ret = nfs_revalidate_inode(NFS_SERVER(inode), inode);
+	if (ret)
+		return ret;
+
+	ret = nfs4_xattr_cache_list(inode, list, list_len);
+	if (ret >= 0 || (ret < 0 && ret != -ENOENT))
+		return ret;
+
+	cookie = 0;
+	eof = false;
+	buflen = list_len ? list_len : XATTR_LIST_MAX;
+	buf = list_len ? list : NULL;
+	size = 0;
+
+	while (!eof) {
+		ret = nfs42_proc_listxattrs(inode, buf, buflen,
+		    &cookie, &eof);
+		if (ret < 0)
+			return ret;
+
+		if (list_len) {
+			buf += ret;
+			buflen -= ret;
+		}
+		size += ret;
+	}
+
+	if (list_len)
+		nfs4_xattr_cache_set_list(inode, list, size);
+
+	return size;
+}
+
+#else
+
+static ssize_t
+nfs4_listxattr_nfs4_user(struct inode *inode, char *list, size_t list_len)
+{
+	return 0;
+}
+#endif /* CONFIG_NFS_V4_2 */
+
+/*
+ * nfs_fhget will use either the mounted_on_fileid or the fileid
+ */
+static void nfs_fixup_referral_attributes(struct nfs_fattr *fattr)
+{
+	if (!(((fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID) ||
+	       (fattr->valid & NFS_ATTR_FATTR_FILEID)) &&
+	      (fattr->valid & NFS_ATTR_FATTR_FSID) &&
+	      (fattr->valid & NFS_ATTR_FATTR_V4_LOCATIONS)))
+		return;
+
+	fattr->valid |= NFS_ATTR_FATTR_TYPE | NFS_ATTR_FATTR_MODE |
+		NFS_ATTR_FATTR_NLINK | NFS_ATTR_FATTR_V4_REFERRAL;
+	fattr->mode = S_IFDIR | S_IRUGO | S_IXUGO;
+	fattr->nlink = 2;
+}
+
+static int _nfs4_proc_fs_locations(struct rpc_clnt *client, struct inode *dir,
+				   const struct qstr *name,
+				   struct nfs4_fs_locations *fs_locations,
+				   struct page *page)
+{
+	struct nfs_server *server = NFS_SERVER(dir);
+	u32 bitmask[3];
+	struct nfs4_fs_locations_arg args = {
+		.dir_fh = NFS_FH(dir),
+		.name = name,
+		.page = page,
+		.bitmask = bitmask,
+	};
+	struct nfs4_fs_locations_res res = {
+		.fs_locations = fs_locations,
+	};
+	struct rpc_message msg = {
+		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_FS_LOCATIONS],
+		.rpc_argp = &args,
+		.rpc_resp = &res,
+	};
+	int status;
+
+	dprintk("%s: start\n", __func__);
+
+	bitmask[0] = nfs4_fattr_bitmap[0] | FATTR4_WORD0_FS_LOCATIONS;
+	bitmask[1] = nfs4_fattr_bitmap[1];
+
+	/* Ask for the fileid of the absent filesystem if mounted_on_fileid
+	 * is not supported */
+	if (NFS_SERVER(dir)->attr_bitmask[1] & FATTR4_WORD1_MOUNTED_ON_FILEID)
+		bitmask[0] &= ~FATTR4_WORD0_FILEID;
+	else
+		bitmask[1] &= ~FATTR4_WORD1_MOUNTED_ON_FILEID;
+
+	nfs_fattr_init(&fs_locations->fattr);
+	fs_locations->server = server;
+	fs_locations->nlocations = 0;
+	status = nfs4_call_sync(client, server, &msg, &args.seq_args, &res.seq_res, 0);
+	dprintk("%s: returned status = %d\n", __func__, status);
+	return status;
+}
+
+int nfs4_proc_fs_locations(struct rpc_clnt *client, struct inode *dir,
+			   const struct qstr *name,
+			   struct nfs4_fs_locations *fs_locations,
+			   struct page *page)
+{
+	struct nfs4_exception exception = {
+		.interruptible = true,
+	};
+	int err;
+	do {
+		err = _nfs4_proc_fs_locations(client, dir, name,
+				fs_locations, page);
+		trace_nfs4_get_fs_locations(dir, name, err);
+		err = nfs4_handle_exception(NFS_SERVER(dir), err,
+				&exception);
+	} while (exception.retry);
+	return err;
+}
+
+/*
+ * This operation also signals the server that this client is
+ * performing migration recovery.  The server can stop returning
+ * NFS4ERR_LEASE_MOVED to this client.  A RENEW operation is
+ * appended to this compound to identify the client ID which is
+ * performing recovery.
+ */
+static int _nfs40_proc_get_locations(struct inode *inode,
+				     struct nfs4_fs_locations *locations,
+				     struct page *page, const struct cred *cred)
+{
+	struct nfs_server *server = NFS_SERVER(inode);
+	struct rpc_clnt *clnt = server->client;
+	u32 bitmask[2] = {
+		[0] = FATTR4_WORD0_FSID | FATTR4_WORD0_FS_LOCATIONS,
+	};
+	struct nfs4_fs_locations_arg args = {
+		.clientid	= server->nfs_client->cl_clientid,
+		.fh		= NFS_FH(inode),
+		.page		= page,
+		.bitmask	= bitmask,
+		.migration	= 1,		/* skip LOOKUP */
+		.renew		= 1,		/* append RENEW */
+	};
+	struct nfs4_fs_locations_res res = {
+		.fs_locations	= locations,
+		.migration	= 1,
+		.renew		= 1,
+	};
+	struct rpc_message msg = {
+		.rpc_proc	= &nfs4_procedures[NFSPROC4_CLNT_FS_LOCATIONS],
+		.rpc_argp	= &args,
+		.rpc_resp	= &res,
+		.rpc_cred	= cred,
+	};
+	unsigned long now = jiffies;
+	int status;
+
+	nfs_fattr_init(&locations->fattr);
+	locations->server = server;
+	locations->nlocations = 0;
+
+	nfs4_init_sequence(&args.seq_args, &res.seq_res, 0, 1);
+	status = nfs4_call_sync_sequence(clnt, server, &msg,
+					&args.seq_args, &res.seq_res);
+	if (status)
+		return status;
+
+	renew_lease(server, now);
+	return 0;
+}
+
+#ifdef CONFIG_NFS_V4_1
+
+/*
+ * This operation also signals the server that this client is
+ * performing migration recovery.  The server can stop asserting
+ * SEQ4_STATUS_LEASE_MOVED for this client.  The client ID
+ * performing this operation is identified in the SEQUENCE
+ * operation in this compound.
+ *
+ * When the client supports GETATTR(fs_locations_info), it can
+ * be plumbed in here.
+ */
+static int _nfs41_proc_get_locations(struct inode *inode,
+				     struct nfs4_fs_locations *locations,
+				     struct page *page, const struct cred *cred)
+{
+	struct nfs_server *server = NFS_SERVER(inode);
+	struct rpc_clnt *clnt = server->client;
+	u32 bitmask[2] = {
+		[0] = FATTR4_WORD0_FSID | FATTR4_WORD0_FS_LOCATIONS,
+	};
+	struct nfs4_fs_locations_arg args = {
+		.fh		= NFS_FH(inode),
+		.page		= page,
+		.bitmask	= bitmask,
+		.migration	= 1,		/* skip LOOKUP */
+	};
+	struct nfs4_fs_locations_res res = {
+		.fs_locations	= locations,
+		.migration	= 1,
+	};
+	struct rpc_message msg = {
+		.rpc_proc	= &nfs4_procedures[NFSPROC4_CLNT_FS_LOCATIONS],
+		.rpc_argp	= &args,
+		.rpc_resp	= &res,
+		.rpc_cred	= cred,
+	};
+	int status;
+
+	nfs_fattr_init(&locations->fattr);
+	locations->server = server;
+	locations->nlocations = 0;
+
+	nfs4_init_sequence(&args.seq_args, &res.seq_res, 0, 1);
+	status = nfs4_call_sync_sequence(clnt, server, &msg,
+					&args.seq_args, &res.seq_res);
+	if (status == NFS4_OK &&
+	    res.seq_res.sr_status_flags & SEQ4_STATUS_LEASE_MOVED)
+		status = -NFS4ERR_LEASE_MOVED;
+	return status;
+}
+
+#endif	/* CONFIG_NFS_V4_1 */
+
+/**
+ * nfs4_proc_get_locations - discover locations for a migrated FSID
+ * @inode: inode on FSID that is migrating
+ * @locations: result of query
+ * @page: buffer
+ * @cred: credential to use for this operation
+ *
+ * Returns NFS4_OK on success, a negative NFS4ERR status code if the
+ * operation failed, or a negative errno if a local error occurred.
+ *
+ * On success, "locations" is filled in, but if the server has
+ * no locations information, NFS_ATTR_FATTR_V4_LOCATIONS is not
+ * asserted.
+ *
+ * -NFS4ERR_LEASE_MOVED is returned if the server still has leases
+ * from this client that require migration recovery.
+ */
+int nfs4_proc_get_locations(struct inode *inode,
+			    struct nfs4_fs_locations *locations,
+			    struct page *page, const struct cred *cred)
+{
+	struct nfs_server *server = NFS_SERVER(inode);
+	struct nfs_client *clp = server->nfs_client;
+	const struct nfs4_mig_recovery_ops *ops =
+					clp->cl_mvops->mig_recovery_ops;
+	struct nfs4_exception exception = {
+		.interruptible = true,
+	};
+	int status;
+
+	dprintk("%s: FSID %llx:%llx on \"%s\"\n", __func__,
+		(unsigned long long)server->fsid.major,
+		(unsigned long long)server->fsid.minor,
+		clp->cl_hostname);
+	nfs_display_fhandle(NFS_FH(inode), __func__);
+
+	do {
+		status = ops->get_locations(inode, locations, page, cred);
+		if (status != -NFS4ERR_DELAY)
+			break;
+		nfs4_handle_exception(server, status, &exception);
+	} while (exception.retry);
+	return status;
+}
+
+/*
+ * This operation also signals the server that this client is
+ * performing "lease moved" recovery.  The server can stop
+ * returning NFS4ERR_LEASE_MOVED to this client.  A RENEW operation
+ * is appended to this compound to identify the client ID which is
+ * performing recovery.
+ */
+static int _nfs40_proc_fsid_present(struct inode *inode, const struct cred *cred)
+{
+	struct nfs_server *server = NFS_SERVER(inode);
+	struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
+	struct rpc_clnt *clnt = server->client;
+	struct nfs4_fsid_present_arg args = {
+		.fh		= NFS_FH(inode),
+		.clientid	= clp->cl_clientid,
+		.renew		= 1,		/* append RENEW */
+	};
+	struct nfs4_fsid_present_res res = {
+		.renew		= 1,
+	};
+	struct rpc_message msg = {
+		.rpc_proc	= &nfs4_procedures[NFSPROC4_CLNT_FSID_PRESENT],
+		.rpc_argp	= &args,
+		.rpc_resp	= &res,
+		.rpc_cred	= cred,
+	};
+	unsigned long now = jiffies;
+	int status;
+
+	res.fh = nfs_alloc_fhandle();
+	if (res.fh == NULL)
+		return -ENOMEM;
+
+	nfs4_init_sequence(&args.seq_args, &res.seq_res, 0, 1);
+	status = nfs4_call_sync_sequence(clnt, server, &msg,
+						&args.seq_args, &res.seq_res);
+	nfs_free_fhandle(res.fh);
+	if (status)
+		return status;
+
+	do_renew_lease(clp, now);
+	return 0;
+}
+
+#ifdef CONFIG_NFS_V4_1
+
+/*
+ * This operation also signals the server that this client is
+ * performing "lease moved" recovery.  The server can stop asserting
+ * SEQ4_STATUS_LEASE_MOVED for this client.  The client ID performing
+ * this operation is identified in the SEQUENCE operation in this
+ * compound.
+ */
+static int _nfs41_proc_fsid_present(struct inode *inode, const struct cred *cred)
+{
+	struct nfs_server *server = NFS_SERVER(inode);
+	struct rpc_clnt *clnt = server->client;
+	struct nfs4_fsid_present_arg args = {
+		.fh		= NFS_FH(inode),
+	};
+	struct nfs4_fsid_present_res res = {
+	};
+	struct rpc_message msg = {
+		.rpc_proc	= &nfs4_procedures[NFSPROC4_CLNT_FSID_PRESENT],
+		.rpc_argp	= &args,
+		.rpc_resp	= &res,
+		.rpc_cred	= cred,
+	};
+	int status;
+
+	res.fh = nfs_alloc_fhandle();
+	if (res.fh == NULL)
+		return -ENOMEM;
+
+	nfs4_init_sequence(&args.seq_args, &res.seq_res, 0, 1);
+	status = nfs4_call_sync_sequence(clnt, server, &msg,
+						&args.seq_args, &res.seq_res);
+	nfs_free_fhandle(res.fh);
+	if (status == NFS4_OK &&
+	    res.seq_res.sr_status_flags & SEQ4_STATUS_LEASE_MOVED)
+		status = -NFS4ERR_LEASE_MOVED;
+	return status;
+}
+
+#endif	/* CONFIG_NFS_V4_1 */
+
+/**
+ * nfs4_proc_fsid_present - Is this FSID present or absent on server?
+ * @inode: inode on FSID to check
+ * @cred: credential to use for this operation
+ *
+ * Server indicates whether the FSID is present, moved, or not
+ * recognized.  This operation is necessary to clear a LEASE_MOVED
+ * condition for this client ID.
+ *
+ * Returns NFS4_OK if the FSID is present on this server,
+ * -NFS4ERR_MOVED if the FSID is no longer present, a negative
+ *  NFS4ERR code if some error occurred on the server, or a
+ *  negative errno if a local failure occurred.
+ */
+int nfs4_proc_fsid_present(struct inode *inode, const struct cred *cred)
+{
+	struct nfs_server *server = NFS_SERVER(inode);
+	struct nfs_client *clp = server->nfs_client;
+	const struct nfs4_mig_recovery_ops *ops =
+					clp->cl_mvops->mig_recovery_ops;
+	struct nfs4_exception exception = {
+		.interruptible = true,
+	};
+	int status;
+
+	dprintk("%s: FSID %llx:%llx on \"%s\"\n", __func__,
+		(unsigned long long)server->fsid.major,
+		(unsigned long long)server->fsid.minor,
+		clp->cl_hostname);
+	nfs_display_fhandle(NFS_FH(inode), __func__);
+
+	do {
+		status = ops->fsid_present(inode, cred);
+		if (status != -NFS4ERR_DELAY)
+			break;
+		nfs4_handle_exception(server, status, &exception);
+	} while (exception.retry);
+	return status;
+}
+
+/*
+ * If 'use_integrity' is true and the state managment nfs_client
+ * cl_rpcclient is using krb5i/p, use the integrity protected cl_rpcclient
+ * and the machine credential as per RFC3530bis and RFC5661 Security
+ * Considerations sections. Otherwise, just use the user cred with the
+ * filesystem's rpc_client.
+ */
+static int _nfs4_proc_secinfo(struct inode *dir, const struct qstr *name, struct nfs4_secinfo_flavors *flavors, bool use_integrity)
+{
+	int status;
+	struct rpc_clnt *clnt = NFS_SERVER(dir)->client;
+	struct nfs_client *clp = NFS_SERVER(dir)->nfs_client;
+	struct nfs4_secinfo_arg args = {
+		.dir_fh = NFS_FH(dir),
+		.name   = name,
+	};
+	struct nfs4_secinfo_res res = {
+		.flavors     = flavors,
+	};
+	struct rpc_message msg = {
+		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_SECINFO],
+		.rpc_argp = &args,
+		.rpc_resp = &res,
+	};
+	struct nfs4_call_sync_data data = {
+		.seq_server = NFS_SERVER(dir),
+		.seq_args = &args.seq_args,
+		.seq_res = &res.seq_res,
+	};
+	struct rpc_task_setup task_setup = {
+		.rpc_client = clnt,
+		.rpc_message = &msg,
+		.callback_ops = clp->cl_mvops->call_sync_ops,
+		.callback_data = &data,
+		.flags = RPC_TASK_NO_ROUND_ROBIN,
+	};
+	const struct cred *cred = NULL;
+
+	if (use_integrity) {
+		clnt = clp->cl_rpcclient;
+		task_setup.rpc_client = clnt;
+
+		cred = nfs4_get_clid_cred(clp);
+		msg.rpc_cred = cred;
+	}
+
+	dprintk("NFS call  secinfo %s\n", name->name);
+
+	nfs4_state_protect(clp, NFS_SP4_MACH_CRED_SECINFO, &clnt, &msg);
+	nfs4_init_sequence(&args.seq_args, &res.seq_res, 0, 0);
+	status = nfs4_call_sync_custom(&task_setup);
+
+	dprintk("NFS reply  secinfo: %d\n", status);
+
+	put_cred(cred);
+	return status;
+}
+
+int nfs4_proc_secinfo(struct inode *dir, const struct qstr *name,
+		      struct nfs4_secinfo_flavors *flavors)
+{
+	struct nfs4_exception exception = {
+		.interruptible = true,
+	};
+	int err;
+	do {
+		err = -NFS4ERR_WRONGSEC;
+
+		/* try to use integrity protection with machine cred */
+		if (_nfs4_is_integrity_protected(NFS_SERVER(dir)->nfs_client))
+			err = _nfs4_proc_secinfo(dir, name, flavors, true);
+
+		/*
+		 * if unable to use integrity protection, or SECINFO with
+		 * integrity protection returns NFS4ERR_WRONGSEC (which is
+		 * disallowed by spec, but exists in deployed servers) use
+		 * the current filesystem's rpc_client and the user cred.
+		 */
+		if (err == -NFS4ERR_WRONGSEC)
+			err = _nfs4_proc_secinfo(dir, name, flavors, false);
+
+		trace_nfs4_secinfo(dir, name, err);
+		err = nfs4_handle_exception(NFS_SERVER(dir), err,
+				&exception);
+	} while (exception.retry);
+	return err;
+}
+
+#ifdef CONFIG_NFS_V4_1
+/*
+ * Check the exchange flags returned by the server for invalid flags, having
+ * both PNFS and NON_PNFS flags set, and not having one of NON_PNFS, PNFS, or
+ * DS flags set.
+ */
+static int nfs4_check_cl_exchange_flags(u32 flags, u32 version)
+{
+	if (version >= 2 && (flags & ~EXCHGID4_2_FLAG_MASK_R))
+		goto out_inval;
+	else if (version < 2 && (flags & ~EXCHGID4_FLAG_MASK_R))
+		goto out_inval;
+	if ((flags & EXCHGID4_FLAG_USE_PNFS_MDS) &&
+	    (flags & EXCHGID4_FLAG_USE_NON_PNFS))
+		goto out_inval;
+	if (!(flags & (EXCHGID4_FLAG_MASK_PNFS)))
+		goto out_inval;
+	return NFS_OK;
+out_inval:
+	return -NFS4ERR_INVAL;
+}
+
+static bool
+nfs41_same_server_scope(struct nfs41_server_scope *a,
+			struct nfs41_server_scope *b)
+{
+	if (a->server_scope_sz != b->server_scope_sz)
+		return false;
+	return memcmp(a->server_scope, b->server_scope, a->server_scope_sz) == 0;
+}
+
+static void
+nfs4_bind_one_conn_to_session_done(struct rpc_task *task, void *calldata)
+{
+	struct nfs41_bind_conn_to_session_args *args = task->tk_msg.rpc_argp;
+	struct nfs41_bind_conn_to_session_res *res = task->tk_msg.rpc_resp;
+	struct nfs_client *clp = args->client;
+
+	switch (task->tk_status) {
+	case -NFS4ERR_BADSESSION:
+	case -NFS4ERR_DEADSESSION:
+		nfs4_schedule_session_recovery(clp->cl_session,
+				task->tk_status);
+		return;
+	}
+	if (args->dir == NFS4_CDFC4_FORE_OR_BOTH &&
+			res->dir != NFS4_CDFS4_BOTH) {
+		rpc_task_close_connection(task);
+		if (args->retries++ < MAX_BIND_CONN_TO_SESSION_RETRIES)
+			rpc_restart_call(task);
+	}
+}
+
+static const struct rpc_call_ops nfs4_bind_one_conn_to_session_ops = {
+	.rpc_call_done =  nfs4_bind_one_conn_to_session_done,
+};
+
+/*
+ * nfs4_proc_bind_one_conn_to_session()
+ *
+ * The 4.1 client currently uses the same TCP connection for the
+ * fore and backchannel.
+ */
+static
+int nfs4_proc_bind_one_conn_to_session(struct rpc_clnt *clnt,
+		struct rpc_xprt *xprt,
+		struct nfs_client *clp,
+		const struct cred *cred)
+{
+	int status;
+	struct nfs41_bind_conn_to_session_args args = {
+		.client = clp,
+		.dir = NFS4_CDFC4_FORE_OR_BOTH,
+		.retries = 0,
+	};
+	struct nfs41_bind_conn_to_session_res res;
+	struct rpc_message msg = {
+		.rpc_proc =
+			&nfs4_procedures[NFSPROC4_CLNT_BIND_CONN_TO_SESSION],
+		.rpc_argp = &args,
+		.rpc_resp = &res,
+		.rpc_cred = cred,
+	};
+	struct rpc_task_setup task_setup_data = {
+		.rpc_client = clnt,
+		.rpc_xprt = xprt,
+		.callback_ops = &nfs4_bind_one_conn_to_session_ops,
+		.rpc_message = &msg,
+		.flags = RPC_TASK_TIMEOUT,
+	};
+	struct rpc_task *task;
+
+	nfs4_copy_sessionid(&args.sessionid, &clp->cl_session->sess_id);
+	if (!(clp->cl_session->flags & SESSION4_BACK_CHAN))
+		args.dir = NFS4_CDFC4_FORE;
+
+	/* Do not set the backchannel flag unless this is clnt->cl_xprt */
+	if (xprt != rcu_access_pointer(clnt->cl_xprt))
+		args.dir = NFS4_CDFC4_FORE;
+
+	task = rpc_run_task(&task_setup_data);
+	if (!IS_ERR(task)) {
+		status = task->tk_status;
+		rpc_put_task(task);
+	} else
+		status = PTR_ERR(task);
+	trace_nfs4_bind_conn_to_session(clp, status);
+	if (status == 0) {
+		if (memcmp(res.sessionid.data,
+		    clp->cl_session->sess_id.data, NFS4_MAX_SESSIONID_LEN)) {
+			dprintk("NFS: %s: Session ID mismatch\n", __func__);
+			return -EIO;
+		}
+		if ((res.dir & args.dir) != res.dir || res.dir == 0) {
+			dprintk("NFS: %s: Unexpected direction from server\n",
+				__func__);
+			return -EIO;
+		}
+		if (res.use_conn_in_rdma_mode != args.use_conn_in_rdma_mode) {
+			dprintk("NFS: %s: Server returned RDMA mode = true\n",
+				__func__);
+			return -EIO;
+		}
+	}
+
+	return status;
+}
+
+struct rpc_bind_conn_calldata {
+	struct nfs_client *clp;
+	const struct cred *cred;
+};
+
+static int
+nfs4_proc_bind_conn_to_session_callback(struct rpc_clnt *clnt,
+		struct rpc_xprt *xprt,
+		void *calldata)
+{
+	struct rpc_bind_conn_calldata *p = calldata;
+
+	return nfs4_proc_bind_one_conn_to_session(clnt, xprt, p->clp, p->cred);
+}
+
+int nfs4_proc_bind_conn_to_session(struct nfs_client *clp, const struct cred *cred)
+{
+	struct rpc_bind_conn_calldata data = {
+		.clp = clp,
+		.cred = cred,
+	};
+	return rpc_clnt_iterate_for_each_xprt(clp->cl_rpcclient,
+			nfs4_proc_bind_conn_to_session_callback, &data);
+}
+
+/*
+ * Minimum set of SP4_MACH_CRED operations from RFC 5661 in the enforce map
+ * and operations we'd like to see to enable certain features in the allow map
+ */
+static const struct nfs41_state_protection nfs4_sp4_mach_cred_request = {
+	.how = SP4_MACH_CRED,
+	.enforce.u.words = {
+		[1] = 1 << (OP_BIND_CONN_TO_SESSION - 32) |
+		      1 << (OP_EXCHANGE_ID - 32) |
+		      1 << (OP_CREATE_SESSION - 32) |
+		      1 << (OP_DESTROY_SESSION - 32) |
+		      1 << (OP_DESTROY_CLIENTID - 32)
+	},
+	.allow.u.words = {
+		[0] = 1 << (OP_CLOSE) |
+		      1 << (OP_OPEN_DOWNGRADE) |
+		      1 << (OP_LOCKU) |
+		      1 << (OP_DELEGRETURN) |
+		      1 << (OP_COMMIT),
+		[1] = 1 << (OP_SECINFO - 32) |
+		      1 << (OP_SECINFO_NO_NAME - 32) |
+		      1 << (OP_LAYOUTRETURN - 32) |
+		      1 << (OP_TEST_STATEID - 32) |
+		      1 << (OP_FREE_STATEID - 32) |
+		      1 << (OP_WRITE - 32)
+	}
+};
+
+/*
+ * Select the state protection mode for client `clp' given the server results
+ * from exchange_id in `sp'.
+ *
+ * Returns 0 on success, negative errno otherwise.
+ */
+static int nfs4_sp4_select_mode(struct nfs_client *clp,
+				 struct nfs41_state_protection *sp)
+{
+	static const u32 supported_enforce[NFS4_OP_MAP_NUM_WORDS] = {
+		[1] = 1 << (OP_BIND_CONN_TO_SESSION - 32) |
+		      1 << (OP_EXCHANGE_ID - 32) |
+		      1 << (OP_CREATE_SESSION - 32) |
+		      1 << (OP_DESTROY_SESSION - 32) |
+		      1 << (OP_DESTROY_CLIENTID - 32)
+	};
+	unsigned long flags = 0;
+	unsigned int i;
+	int ret = 0;
+
+	if (sp->how == SP4_MACH_CRED) {
+		/* Print state protect result */
+		dfprintk(MOUNT, "Server SP4_MACH_CRED support:\n");
+		for (i = 0; i <= LAST_NFS4_OP; i++) {
+			if (test_bit(i, sp->enforce.u.longs))
+				dfprintk(MOUNT, "  enforce op %d\n", i);
+			if (test_bit(i, sp->allow.u.longs))
+				dfprintk(MOUNT, "  allow op %d\n", i);
+		}
+
+		/* make sure nothing is on enforce list that isn't supported */
+		for (i = 0; i < NFS4_OP_MAP_NUM_WORDS; i++) {
+			if (sp->enforce.u.words[i] & ~supported_enforce[i]) {
+				dfprintk(MOUNT, "sp4_mach_cred: disabled\n");
+				ret = -EINVAL;
+				goto out;
+			}
+		}
+
+		/*
+		 * Minimal mode - state operations are allowed to use machine
+		 * credential.  Note this already happens by default, so the
+		 * client doesn't have to do anything more than the negotiation.
+		 *
+		 * NOTE: we don't care if EXCHANGE_ID is in the list -
+		 *       we're already using the machine cred for exchange_id
+		 *       and will never use a different cred.
+		 */
+		if (test_bit(OP_BIND_CONN_TO_SESSION, sp->enforce.u.longs) &&
+		    test_bit(OP_CREATE_SESSION, sp->enforce.u.longs) &&
+		    test_bit(OP_DESTROY_SESSION, sp->enforce.u.longs) &&
+		    test_bit(OP_DESTROY_CLIENTID, sp->enforce.u.longs)) {
+			dfprintk(MOUNT, "sp4_mach_cred:\n");
+			dfprintk(MOUNT, "  minimal mode enabled\n");
+			__set_bit(NFS_SP4_MACH_CRED_MINIMAL, &flags);
+		} else {
+			dfprintk(MOUNT, "sp4_mach_cred: disabled\n");
+			ret = -EINVAL;
+			goto out;
+		}
+
+		if (test_bit(OP_CLOSE, sp->allow.u.longs) &&
+		    test_bit(OP_OPEN_DOWNGRADE, sp->allow.u.longs) &&
+		    test_bit(OP_DELEGRETURN, sp->allow.u.longs) &&
+		    test_bit(OP_LOCKU, sp->allow.u.longs)) {
+			dfprintk(MOUNT, "  cleanup mode enabled\n");
+			__set_bit(NFS_SP4_MACH_CRED_CLEANUP, &flags);
+		}
+
+		if (test_bit(OP_LAYOUTRETURN, sp->allow.u.longs)) {
+			dfprintk(MOUNT, "  pnfs cleanup mode enabled\n");
+			__set_bit(NFS_SP4_MACH_CRED_PNFS_CLEANUP, &flags);
+		}
+
+		if (test_bit(OP_SECINFO, sp->allow.u.longs) &&
+		    test_bit(OP_SECINFO_NO_NAME, sp->allow.u.longs)) {
+			dfprintk(MOUNT, "  secinfo mode enabled\n");
+			__set_bit(NFS_SP4_MACH_CRED_SECINFO, &flags);
+		}
+
+		if (test_bit(OP_TEST_STATEID, sp->allow.u.longs) &&
+		    test_bit(OP_FREE_STATEID, sp->allow.u.longs)) {
+			dfprintk(MOUNT, "  stateid mode enabled\n");
+			__set_bit(NFS_SP4_MACH_CRED_STATEID, &flags);
+		}
+
+		if (test_bit(OP_WRITE, sp->allow.u.longs)) {
+			dfprintk(MOUNT, "  write mode enabled\n");
+			__set_bit(NFS_SP4_MACH_CRED_WRITE, &flags);
+		}
+
+		if (test_bit(OP_COMMIT, sp->allow.u.longs)) {
+			dfprintk(MOUNT, "  commit mode enabled\n");
+			__set_bit(NFS_SP4_MACH_CRED_COMMIT, &flags);
+		}
+	}
+out:
+	clp->cl_sp4_flags = flags;
+	return ret;
+}
+
+struct nfs41_exchange_id_data {
+	struct nfs41_exchange_id_res res;
+	struct nfs41_exchange_id_args args;
+};
+
+static void nfs4_exchange_id_release(void *data)
+{
+	struct nfs41_exchange_id_data *cdata =
+					(struct nfs41_exchange_id_data *)data;
+
+	nfs_put_client(cdata->args.client);
+	kfree(cdata->res.impl_id);
+	kfree(cdata->res.server_scope);
+	kfree(cdata->res.server_owner);
+	kfree(cdata);
+}
+
+static const struct rpc_call_ops nfs4_exchange_id_call_ops = {
+	.rpc_release = nfs4_exchange_id_release,
+};
+
+/*
+ * _nfs4_proc_exchange_id()
+ *
+ * Wrapper for EXCHANGE_ID operation.
+ */
+static struct rpc_task *
+nfs4_run_exchange_id(struct nfs_client *clp, const struct cred *cred,
+			u32 sp4_how, struct rpc_xprt *xprt)
+{
+	struct rpc_message msg = {
+		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_EXCHANGE_ID],
+		.rpc_cred = cred,
+	};
+	struct rpc_task_setup task_setup_data = {
+		.rpc_client = clp->cl_rpcclient,
+		.callback_ops = &nfs4_exchange_id_call_ops,
+		.rpc_message = &msg,
+		.flags = RPC_TASK_TIMEOUT | RPC_TASK_NO_ROUND_ROBIN,
+	};
+	struct nfs41_exchange_id_data *calldata;
+	int status;
+
+	if (!refcount_inc_not_zero(&clp->cl_count))
+		return ERR_PTR(-EIO);
+
+	status = -ENOMEM;
+	calldata = kzalloc(sizeof(*calldata), GFP_NOFS);
+	if (!calldata)
+		goto out;
+
+	nfs4_init_boot_verifier(clp, &calldata->args.verifier);
+
+	status = nfs4_init_uniform_client_string(clp);
+	if (status)
+		goto out_calldata;
+
+	calldata->res.server_owner = kzalloc(sizeof(struct nfs41_server_owner),
+						GFP_NOFS);
+	status = -ENOMEM;
+	if (unlikely(calldata->res.server_owner == NULL))
+		goto out_calldata;
+
+	calldata->res.server_scope = kzalloc(sizeof(struct nfs41_server_scope),
+					GFP_NOFS);
+	if (unlikely(calldata->res.server_scope == NULL))
+		goto out_server_owner;
+
+	calldata->res.impl_id = kzalloc(sizeof(struct nfs41_impl_id), GFP_NOFS);
+	if (unlikely(calldata->res.impl_id == NULL))
+		goto out_server_scope;
+
+	switch (sp4_how) {
+	case SP4_NONE:
+		calldata->args.state_protect.how = SP4_NONE;
+		break;
+
+	case SP4_MACH_CRED:
+		calldata->args.state_protect = nfs4_sp4_mach_cred_request;
+		break;
+
+	default:
+		/* unsupported! */
+		WARN_ON_ONCE(1);
+		status = -EINVAL;
+		goto out_impl_id;
+	}
+	if (xprt) {
+		task_setup_data.rpc_xprt = xprt;
+		task_setup_data.flags |= RPC_TASK_SOFTCONN;
+		memcpy(calldata->args.verifier.data, clp->cl_confirm.data,
+				sizeof(calldata->args.verifier.data));
+	}
+	calldata->args.client = clp;
+	calldata->args.flags = EXCHGID4_FLAG_SUPP_MOVED_REFER |
+	EXCHGID4_FLAG_BIND_PRINC_STATEID;
+#ifdef CONFIG_NFS_V4_1_MIGRATION
+	calldata->args.flags |= EXCHGID4_FLAG_SUPP_MOVED_MIGR;
+#endif
+	msg.rpc_argp = &calldata->args;
+	msg.rpc_resp = &calldata->res;
+	task_setup_data.callback_data = calldata;
+
+	return rpc_run_task(&task_setup_data);
+
+out_impl_id:
+	kfree(calldata->res.impl_id);
+out_server_scope:
+	kfree(calldata->res.server_scope);
+out_server_owner:
+	kfree(calldata->res.server_owner);
+out_calldata:
+	kfree(calldata);
+out:
+	nfs_put_client(clp);
+	return ERR_PTR(status);
+}
+
+/*
+ * _nfs4_proc_exchange_id()
+ *
+ * Wrapper for EXCHANGE_ID operation.
+ */
+static int _nfs4_proc_exchange_id(struct nfs_client *clp, const struct cred *cred,
+			u32 sp4_how)
+{
+	struct rpc_task *task;
+	struct nfs41_exchange_id_args *argp;
+	struct nfs41_exchange_id_res *resp;
+	unsigned long now = jiffies;
+	int status;
+
+	task = nfs4_run_exchange_id(clp, cred, sp4_how, NULL);
+	if (IS_ERR(task))
+		return PTR_ERR(task);
+
+	argp = task->tk_msg.rpc_argp;
+	resp = task->tk_msg.rpc_resp;
+	status = task->tk_status;
+	if (status  != 0)
+		goto out;
+
+	status = nfs4_check_cl_exchange_flags(resp->flags,
+			clp->cl_mvops->minor_version);
+	if (status  != 0)
+		goto out;
+
+	status = nfs4_sp4_select_mode(clp, &resp->state_protect);
+	if (status != 0)
+		goto out;
+
+	do_renew_lease(clp, now);
+
+	clp->cl_clientid = resp->clientid;
+	clp->cl_exchange_flags = resp->flags;
+	clp->cl_seqid = resp->seqid;
+	/* Client ID is not confirmed */
+	if (!(resp->flags & EXCHGID4_FLAG_CONFIRMED_R))
+		clear_bit(NFS4_SESSION_ESTABLISHED,
+			  &clp->cl_session->session_state);
+
+	if (clp->cl_serverscope != NULL &&
+	    !nfs41_same_server_scope(clp->cl_serverscope,
+				resp->server_scope)) {
+		dprintk("%s: server_scope mismatch detected\n",
+			__func__);
+		set_bit(NFS4CLNT_SERVER_SCOPE_MISMATCH, &clp->cl_state);
+	}
+
+	swap(clp->cl_serverowner, resp->server_owner);
+	swap(clp->cl_serverscope, resp->server_scope);
+	swap(clp->cl_implid, resp->impl_id);
+
+	/* Save the EXCHANGE_ID verifier session trunk tests */
+	memcpy(clp->cl_confirm.data, argp->verifier.data,
+	       sizeof(clp->cl_confirm.data));
+out:
+	trace_nfs4_exchange_id(clp, status);
+	rpc_put_task(task);
+	return status;
+}
+
+/*
+ * nfs4_proc_exchange_id()
+ *
+ * Returns zero, a negative errno, or a negative NFS4ERR status code.
+ *
+ * Since the clientid has expired, all compounds using sessions
+ * associated with the stale clientid will be returning
+ * NFS4ERR_BADSESSION in the sequence operation, and will therefore
+ * be in some phase of session reset.
+ *
+ * Will attempt to negotiate SP4_MACH_CRED if krb5i / krb5p auth is used.
+ */
+int nfs4_proc_exchange_id(struct nfs_client *clp, const struct cred *cred)
+{
+	rpc_authflavor_t authflavor = clp->cl_rpcclient->cl_auth->au_flavor;
+	int status;
+
+	/* try SP4_MACH_CRED if krb5i/p	*/
+	if (authflavor == RPC_AUTH_GSS_KRB5I ||
+	    authflavor == RPC_AUTH_GSS_KRB5P) {
+		status = _nfs4_proc_exchange_id(clp, cred, SP4_MACH_CRED);
+		if (!status)
+			return 0;
+	}
+
+	/* try SP4_NONE */
+	return _nfs4_proc_exchange_id(clp, cred, SP4_NONE);
+}
+
+/**
+ * nfs4_test_session_trunk
+ *
+ * This is an add_xprt_test() test function called from
+ * rpc_clnt_setup_test_and_add_xprt.
+ *
+ * The rpc_xprt_switch is referrenced by rpc_clnt_setup_test_and_add_xprt
+ * and is dereferrenced in nfs4_exchange_id_release
+ *
+ * Upon success, add the new transport to the rpc_clnt
+ *
+ * @clnt: struct rpc_clnt to get new transport
+ * @xprt: the rpc_xprt to test
+ * @data: call data for _nfs4_proc_exchange_id.
+ */
+void nfs4_test_session_trunk(struct rpc_clnt *clnt, struct rpc_xprt *xprt,
+			    void *data)
+{
+	struct nfs4_add_xprt_data *adata = (struct nfs4_add_xprt_data *)data;
+	struct rpc_task *task;
+	int status;
+
+	u32 sp4_how;
+
+	dprintk("--> %s try %s\n", __func__,
+		xprt->address_strings[RPC_DISPLAY_ADDR]);
+
+	sp4_how = (adata->clp->cl_sp4_flags == 0 ? SP4_NONE : SP4_MACH_CRED);
+
+	/* Test connection for session trunking. Async exchange_id call */
+	task = nfs4_run_exchange_id(adata->clp, adata->cred, sp4_how, xprt);
+	if (IS_ERR(task))
+		return;
+
+	status = task->tk_status;
+	if (status == 0)
+		status = nfs4_detect_session_trunking(adata->clp,
+				task->tk_msg.rpc_resp, xprt);
+
+	if (status == 0)
+		rpc_clnt_xprt_switch_add_xprt(clnt, xprt);
+
+	rpc_put_task(task);
+}
+EXPORT_SYMBOL_GPL(nfs4_test_session_trunk);
+
+static int _nfs4_proc_destroy_clientid(struct nfs_client *clp,
+		const struct cred *cred)
+{
+	struct rpc_message msg = {
+		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_DESTROY_CLIENTID],
+		.rpc_argp = clp,
+		.rpc_cred = cred,
+	};
+	int status;
+
+	status = rpc_call_sync(clp->cl_rpcclient, &msg,
+			       RPC_TASK_TIMEOUT | RPC_TASK_NO_ROUND_ROBIN);
+	trace_nfs4_destroy_clientid(clp, status);
+	if (status)
+		dprintk("NFS: Got error %d from the server %s on "
+			"DESTROY_CLIENTID.", status, clp->cl_hostname);
+	return status;
+}
+
+static int nfs4_proc_destroy_clientid(struct nfs_client *clp,
+		const struct cred *cred)
+{
+	unsigned int loop;
+	int ret;
+
+	for (loop = NFS4_MAX_LOOP_ON_RECOVER; loop != 0; loop--) {
+		ret = _nfs4_proc_destroy_clientid(clp, cred);
+		switch (ret) {
+		case -NFS4ERR_DELAY:
+		case -NFS4ERR_CLIENTID_BUSY:
+			ssleep(1);
+			break;
+		default:
+			return ret;
+		}
+	}
+	return 0;
+}
+
+int nfs4_destroy_clientid(struct nfs_client *clp)
+{
+	const struct cred *cred;
+	int ret = 0;
+
+	if (clp->cl_mvops->minor_version < 1)
+		goto out;
+	if (clp->cl_exchange_flags == 0)
+		goto out;
+	if (clp->cl_preserve_clid)
+		goto out;
+	cred = nfs4_get_clid_cred(clp);
+	ret = nfs4_proc_destroy_clientid(clp, cred);
+	put_cred(cred);
+	switch (ret) {
+	case 0:
+	case -NFS4ERR_STALE_CLIENTID:
+		clp->cl_exchange_flags = 0;
+	}
+out:
+	return ret;
+}
+
+#endif /* CONFIG_NFS_V4_1 */
+
+struct nfs4_get_lease_time_data {
+	struct nfs4_get_lease_time_args *args;
+	struct nfs4_get_lease_time_res *res;
+	struct nfs_client *clp;
+};
+
+static void nfs4_get_lease_time_prepare(struct rpc_task *task,
+					void *calldata)
+{
+	struct nfs4_get_lease_time_data *data =
+			(struct nfs4_get_lease_time_data *)calldata;
+
+	dprintk("--> %s\n", __func__);
+	/* just setup sequence, do not trigger session recovery
+	   since we're invoked within one */
+	nfs4_setup_sequence(data->clp,
+			&data->args->la_seq_args,
+			&data->res->lr_seq_res,
+			task);
+	dprintk("<-- %s\n", __func__);
+}
+
+/*
+ * Called from nfs4_state_manager thread for session setup, so don't recover
+ * from sequence operation or clientid errors.
+ */
+static void nfs4_get_lease_time_done(struct rpc_task *task, void *calldata)
+{
+	struct nfs4_get_lease_time_data *data =
+			(struct nfs4_get_lease_time_data *)calldata;
+
+	dprintk("--> %s\n", __func__);
+	if (!nfs4_sequence_done(task, &data->res->lr_seq_res))
+		return;
+	switch (task->tk_status) {
+	case -NFS4ERR_DELAY:
+	case -NFS4ERR_GRACE:
+		dprintk("%s Retry: tk_status %d\n", __func__, task->tk_status);
+		rpc_delay(task, NFS4_POLL_RETRY_MIN);
+		task->tk_status = 0;
+		fallthrough;
+	case -NFS4ERR_RETRY_UNCACHED_REP:
+		rpc_restart_call_prepare(task);
+		return;
+	}
+	dprintk("<-- %s\n", __func__);
+}
+
+static const struct rpc_call_ops nfs4_get_lease_time_ops = {
+	.rpc_call_prepare = nfs4_get_lease_time_prepare,
+	.rpc_call_done = nfs4_get_lease_time_done,
+};
+
+int nfs4_proc_get_lease_time(struct nfs_client *clp, struct nfs_fsinfo *fsinfo)
+{
+	struct nfs4_get_lease_time_args args;
+	struct nfs4_get_lease_time_res res = {
+		.lr_fsinfo = fsinfo,
+	};
+	struct nfs4_get_lease_time_data data = {
+		.args = &args,
+		.res = &res,
+		.clp = clp,
+	};
+	struct rpc_message msg = {
+		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_GET_LEASE_TIME],
+		.rpc_argp = &args,
+		.rpc_resp = &res,
+	};
+	struct rpc_task_setup task_setup = {
+		.rpc_client = clp->cl_rpcclient,
+		.rpc_message = &msg,
+		.callback_ops = &nfs4_get_lease_time_ops,
+		.callback_data = &data,
+		.flags = RPC_TASK_TIMEOUT,
+	};
+
+	nfs4_init_sequence(&args.la_seq_args, &res.lr_seq_res, 0, 1);
+	return nfs4_call_sync_custom(&task_setup);
+}
+
+#ifdef CONFIG_NFS_V4_1
+
+/*
+ * Initialize the values to be used by the client in CREATE_SESSION
+ * If nfs4_init_session set the fore channel request and response sizes,
+ * use them.
+ *
+ * Set the back channel max_resp_sz_cached to zero to force the client to
+ * always set csa_cachethis to FALSE because the current implementation
+ * of the back channel DRC only supports caching the CB_SEQUENCE operation.
+ */
+static void nfs4_init_channel_attrs(struct nfs41_create_session_args *args,
+				    struct rpc_clnt *clnt)
+{
+	unsigned int max_rqst_sz, max_resp_sz;
+	unsigned int max_bc_payload = rpc_max_bc_payload(clnt);
+	unsigned int max_bc_slots = rpc_num_bc_slots(clnt);
+
+	max_rqst_sz = NFS_MAX_FILE_IO_SIZE + nfs41_maxwrite_overhead;
+	max_resp_sz = NFS_MAX_FILE_IO_SIZE + nfs41_maxread_overhead;
+
+	/* Fore channel attributes */
+	args->fc_attrs.max_rqst_sz = max_rqst_sz;
+	args->fc_attrs.max_resp_sz = max_resp_sz;
+	args->fc_attrs.max_ops = NFS4_MAX_OPS;
+	args->fc_attrs.max_reqs = max_session_slots;
+
+	dprintk("%s: Fore Channel : max_rqst_sz=%u max_resp_sz=%u "
+		"max_ops=%u max_reqs=%u\n",
+		__func__,
+		args->fc_attrs.max_rqst_sz, args->fc_attrs.max_resp_sz,
+		args->fc_attrs.max_ops, args->fc_attrs.max_reqs);
+
+	/* Back channel attributes */
+	args->bc_attrs.max_rqst_sz = max_bc_payload;
+	args->bc_attrs.max_resp_sz = max_bc_payload;
+	args->bc_attrs.max_resp_sz_cached = 0;
+	args->bc_attrs.max_ops = NFS4_MAX_BACK_CHANNEL_OPS;
+	args->bc_attrs.max_reqs = max_t(unsigned short, max_session_cb_slots, 1);
+	if (args->bc_attrs.max_reqs > max_bc_slots)
+		args->bc_attrs.max_reqs = max_bc_slots;
+
+	dprintk("%s: Back Channel : max_rqst_sz=%u max_resp_sz=%u "
+		"max_resp_sz_cached=%u max_ops=%u max_reqs=%u\n",
+		__func__,
+		args->bc_attrs.max_rqst_sz, args->bc_attrs.max_resp_sz,
+		args->bc_attrs.max_resp_sz_cached, args->bc_attrs.max_ops,
+		args->bc_attrs.max_reqs);
+}
+
+static int nfs4_verify_fore_channel_attrs(struct nfs41_create_session_args *args,
+		struct nfs41_create_session_res *res)
+{
+	struct nfs4_channel_attrs *sent = &args->fc_attrs;
+	struct nfs4_channel_attrs *rcvd = &res->fc_attrs;
+
+	if (rcvd->max_resp_sz > sent->max_resp_sz)
+		return -EINVAL;
+	/*
+	 * Our requested max_ops is the minimum we need; we're not
+	 * prepared to break up compounds into smaller pieces than that.
+	 * So, no point even trying to continue if the server won't
+	 * cooperate:
+	 */
+	if (rcvd->max_ops < sent->max_ops)
+		return -EINVAL;
+	if (rcvd->max_reqs == 0)
+		return -EINVAL;
+	if (rcvd->max_reqs > NFS4_MAX_SLOT_TABLE)
+		rcvd->max_reqs = NFS4_MAX_SLOT_TABLE;
+	return 0;
+}
+
+static int nfs4_verify_back_channel_attrs(struct nfs41_create_session_args *args,
+		struct nfs41_create_session_res *res)
+{
+	struct nfs4_channel_attrs *sent = &args->bc_attrs;
+	struct nfs4_channel_attrs *rcvd = &res->bc_attrs;
+
+	if (!(res->flags & SESSION4_BACK_CHAN))
+		goto out;
+	if (rcvd->max_rqst_sz > sent->max_rqst_sz)
+		return -EINVAL;
+	if (rcvd->max_resp_sz < sent->max_resp_sz)
+		return -EINVAL;
+	if (rcvd->max_resp_sz_cached > sent->max_resp_sz_cached)
+		return -EINVAL;
+	if (rcvd->max_ops > sent->max_ops)
+		return -EINVAL;
+	if (rcvd->max_reqs > sent->max_reqs)
+		return -EINVAL;
+out:
+	return 0;
+}
+
+static int nfs4_verify_channel_attrs(struct nfs41_create_session_args *args,
+				     struct nfs41_create_session_res *res)
+{
+	int ret;
+
+	ret = nfs4_verify_fore_channel_attrs(args, res);
+	if (ret)
+		return ret;
+	return nfs4_verify_back_channel_attrs(args, res);
+}
+
+static void nfs4_update_session(struct nfs4_session *session,
+		struct nfs41_create_session_res *res)
+{
+	nfs4_copy_sessionid(&session->sess_id, &res->sessionid);
+	/* Mark client id and session as being confirmed */
+	session->clp->cl_exchange_flags |= EXCHGID4_FLAG_CONFIRMED_R;
+	set_bit(NFS4_SESSION_ESTABLISHED, &session->session_state);
+	session->flags = res->flags;
+	memcpy(&session->fc_attrs, &res->fc_attrs, sizeof(session->fc_attrs));
+	if (res->flags & SESSION4_BACK_CHAN)
+		memcpy(&session->bc_attrs, &res->bc_attrs,
+				sizeof(session->bc_attrs));
+}
+
+static int _nfs4_proc_create_session(struct nfs_client *clp,
+		const struct cred *cred)
+{
+	struct nfs4_session *session = clp->cl_session;
+	struct nfs41_create_session_args args = {
+		.client = clp,
+		.clientid = clp->cl_clientid,
+		.seqid = clp->cl_seqid,
+		.cb_program = NFS4_CALLBACK,
+	};
+	struct nfs41_create_session_res res;
+
+	struct rpc_message msg = {
+		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_CREATE_SESSION],
+		.rpc_argp = &args,
+		.rpc_resp = &res,
+		.rpc_cred = cred,
+	};
+	int status;
+
+	nfs4_init_channel_attrs(&args, clp->cl_rpcclient);
+	args.flags = (SESSION4_PERSIST | SESSION4_BACK_CHAN);
+
+	status = rpc_call_sync(session->clp->cl_rpcclient, &msg,
+			       RPC_TASK_TIMEOUT | RPC_TASK_NO_ROUND_ROBIN);
+	trace_nfs4_create_session(clp, status);
+
+	switch (status) {
+	case -NFS4ERR_STALE_CLIENTID:
+	case -NFS4ERR_DELAY:
+	case -ETIMEDOUT:
+	case -EACCES:
+	case -EAGAIN:
+		goto out;
+	}
+
+	clp->cl_seqid++;
+	if (!status) {
+		/* Verify the session's negotiated channel_attrs values */
+		status = nfs4_verify_channel_attrs(&args, &res);
+		/* Increment the clientid slot sequence id */
+		if (status)
+			goto out;
+		nfs4_update_session(session, &res);
+	}
+out:
+	return status;
+}
+
+/*
+ * Issues a CREATE_SESSION operation to the server.
+ * It is the responsibility of the caller to verify the session is
+ * expired before calling this routine.
+ */
+int nfs4_proc_create_session(struct nfs_client *clp, const struct cred *cred)
+{
+	int status;
+	unsigned *ptr;
+	struct nfs4_session *session = clp->cl_session;
+
+	dprintk("--> %s clp=%p session=%p\n", __func__, clp, session);
+
+	status = _nfs4_proc_create_session(clp, cred);
+	if (status)
+		goto out;
+
+	/* Init or reset the session slot tables */
+	status = nfs4_setup_session_slot_tables(session);
+	dprintk("slot table setup returned %d\n", status);
+	if (status)
+		goto out;
+
+	ptr = (unsigned *)&session->sess_id.data[0];
+	dprintk("%s client>seqid %d sessionid %u:%u:%u:%u\n", __func__,
+		clp->cl_seqid, ptr[0], ptr[1], ptr[2], ptr[3]);
+out:
+	dprintk("<-- %s\n", __func__);
+	return status;
+}
+
+/*
+ * Issue the over-the-wire RPC DESTROY_SESSION.
+ * The caller must serialize access to this routine.
+ */
+int nfs4_proc_destroy_session(struct nfs4_session *session,
+		const struct cred *cred)
+{
+	struct rpc_message msg = {
+		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_DESTROY_SESSION],
+		.rpc_argp = session,
+		.rpc_cred = cred,
+	};
+	int status = 0;
+
+	dprintk("--> nfs4_proc_destroy_session\n");
+
+	/* session is still being setup */
+	if (!test_and_clear_bit(NFS4_SESSION_ESTABLISHED, &session->session_state))
+		return 0;
+
+	status = rpc_call_sync(session->clp->cl_rpcclient, &msg,
+			       RPC_TASK_TIMEOUT | RPC_TASK_NO_ROUND_ROBIN);
+	trace_nfs4_destroy_session(session->clp, status);
+
+	if (status)
+		dprintk("NFS: Got error %d from the server on DESTROY_SESSION. "
+			"Session has been destroyed regardless...\n", status);
+
+	dprintk("<-- nfs4_proc_destroy_session\n");
+	return status;
+}
+
+/*
+ * Renew the cl_session lease.
+ */
+struct nfs4_sequence_data {
+	struct nfs_client *clp;
+	struct nfs4_sequence_args args;
+	struct nfs4_sequence_res res;
+};
+
+static void nfs41_sequence_release(void *data)
+{
+	struct nfs4_sequence_data *calldata = data;
+	struct nfs_client *clp = calldata->clp;
+
+	if (refcount_read(&clp->cl_count) > 1)
+		nfs4_schedule_state_renewal(clp);
+	nfs_put_client(clp);
+	kfree(calldata);
+}
+
+static int nfs41_sequence_handle_errors(struct rpc_task *task, struct nfs_client *clp)
+{
+	switch(task->tk_status) {
+	case -NFS4ERR_DELAY:
+		rpc_delay(task, NFS4_POLL_RETRY_MAX);
+		return -EAGAIN;
+	default:
+		nfs4_schedule_lease_recovery(clp);
+	}
+	return 0;
+}
+
+static void nfs41_sequence_call_done(struct rpc_task *task, void *data)
+{
+	struct nfs4_sequence_data *calldata = data;
+	struct nfs_client *clp = calldata->clp;
+
+	if (!nfs41_sequence_done(task, task->tk_msg.rpc_resp))
+		return;
+
+	trace_nfs4_sequence(clp, task->tk_status);
+	if (task->tk_status < 0) {
+		dprintk("%s ERROR %d\n", __func__, task->tk_status);
+		if (refcount_read(&clp->cl_count) == 1)
+			goto out;
+
+		if (nfs41_sequence_handle_errors(task, clp) == -EAGAIN) {
+			rpc_restart_call_prepare(task);
+			return;
+		}
+	}
+	dprintk("%s rpc_cred %p\n", __func__, task->tk_msg.rpc_cred);
+out:
+	dprintk("<-- %s\n", __func__);
+}
+
+static void nfs41_sequence_prepare(struct rpc_task *task, void *data)
+{
+	struct nfs4_sequence_data *calldata = data;
+	struct nfs_client *clp = calldata->clp;
+	struct nfs4_sequence_args *args;
+	struct nfs4_sequence_res *res;
+
+	args = task->tk_msg.rpc_argp;
+	res = task->tk_msg.rpc_resp;
+
+	nfs4_setup_sequence(clp, args, res, task);
+}
+
+static const struct rpc_call_ops nfs41_sequence_ops = {
+	.rpc_call_done = nfs41_sequence_call_done,
+	.rpc_call_prepare = nfs41_sequence_prepare,
+	.rpc_release = nfs41_sequence_release,
+};
+
+static struct rpc_task *_nfs41_proc_sequence(struct nfs_client *clp,
+		const struct cred *cred,
+		struct nfs4_slot *slot,
+		bool is_privileged)
+{
+	struct nfs4_sequence_data *calldata;
+	struct rpc_message msg = {
+		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_SEQUENCE],
+		.rpc_cred = cred,
+	};
+	struct rpc_task_setup task_setup_data = {
+		.rpc_client = clp->cl_rpcclient,
+		.rpc_message = &msg,
+		.callback_ops = &nfs41_sequence_ops,
+		.flags = RPC_TASK_ASYNC | RPC_TASK_TIMEOUT,
+	};
+	struct rpc_task *ret;
+
+	ret = ERR_PTR(-EIO);
+	if (!refcount_inc_not_zero(&clp->cl_count))
+		goto out_err;
+
+	ret = ERR_PTR(-ENOMEM);
+	calldata = kzalloc(sizeof(*calldata), GFP_NOFS);
+	if (calldata == NULL)
+		goto out_put_clp;
+	nfs4_init_sequence(&calldata->args, &calldata->res, 0, is_privileged);
+	nfs4_sequence_attach_slot(&calldata->args, &calldata->res, slot);
+	msg.rpc_argp = &calldata->args;
+	msg.rpc_resp = &calldata->res;
+	calldata->clp = clp;
+	task_setup_data.callback_data = calldata;
+
+	ret = rpc_run_task(&task_setup_data);
+	if (IS_ERR(ret))
+		goto out_err;
+	return ret;
+out_put_clp:
+	nfs_put_client(clp);
+out_err:
+	nfs41_release_slot(slot);
+	return ret;
+}
+
+static int nfs41_proc_async_sequence(struct nfs_client *clp, const struct cred *cred, unsigned renew_flags)
+{
+	struct rpc_task *task;
+	int ret = 0;
+
+	if ((renew_flags & NFS4_RENEW_TIMEOUT) == 0)
+		return -EAGAIN;
+	task = _nfs41_proc_sequence(clp, cred, NULL, false);
+	if (IS_ERR(task))
+		ret = PTR_ERR(task);
+	else
+		rpc_put_task_async(task);
+	dprintk("<-- %s status=%d\n", __func__, ret);
+	return ret;
+}
+
+static int nfs4_proc_sequence(struct nfs_client *clp, const struct cred *cred)
+{
+	struct rpc_task *task;
+	int ret;
+
+	task = _nfs41_proc_sequence(clp, cred, NULL, true);
+	if (IS_ERR(task)) {
+		ret = PTR_ERR(task);
+		goto out;
+	}
+	ret = rpc_wait_for_completion_task(task);
+	if (!ret)
+		ret = task->tk_status;
+	rpc_put_task(task);
+out:
+	dprintk("<-- %s status=%d\n", __func__, ret);
+	return ret;
+}
+
+struct nfs4_reclaim_complete_data {
+	struct nfs_client *clp;
+	struct nfs41_reclaim_complete_args arg;
+	struct nfs41_reclaim_complete_res res;
+};
+
+static void nfs4_reclaim_complete_prepare(struct rpc_task *task, void *data)
+{
+	struct nfs4_reclaim_complete_data *calldata = data;
+
+	nfs4_setup_sequence(calldata->clp,
+			&calldata->arg.seq_args,
+			&calldata->res.seq_res,
+			task);
+}
+
+static int nfs41_reclaim_complete_handle_errors(struct rpc_task *task, struct nfs_client *clp)
+{
+	switch(task->tk_status) {
+	case 0:
+		wake_up_all(&clp->cl_lock_waitq);
+		fallthrough;
+	case -NFS4ERR_COMPLETE_ALREADY:
+	case -NFS4ERR_WRONG_CRED: /* What to do here? */
+		break;
+	case -NFS4ERR_DELAY:
+		rpc_delay(task, NFS4_POLL_RETRY_MAX);
+		fallthrough;
+	case -NFS4ERR_RETRY_UNCACHED_REP:
+	case -EACCES:
+		dprintk("%s: failed to reclaim complete error %d for server %s, retrying\n",
+			__func__, task->tk_status, clp->cl_hostname);
+		return -EAGAIN;
+	case -NFS4ERR_BADSESSION:
+	case -NFS4ERR_DEADSESSION:
+	case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
+		break;
+	default:
+		nfs4_schedule_lease_recovery(clp);
+	}
+	return 0;
+}
+
+static void nfs4_reclaim_complete_done(struct rpc_task *task, void *data)
+{
+	struct nfs4_reclaim_complete_data *calldata = data;
+	struct nfs_client *clp = calldata->clp;
+	struct nfs4_sequence_res *res = &calldata->res.seq_res;
+
+	dprintk("--> %s\n", __func__);
+	if (!nfs41_sequence_done(task, res))
+		return;
+
+	trace_nfs4_reclaim_complete(clp, task->tk_status);
+	if (nfs41_reclaim_complete_handle_errors(task, clp) == -EAGAIN) {
+		rpc_restart_call_prepare(task);
+		return;
+	}
+	dprintk("<-- %s\n", __func__);
+}
+
+static void nfs4_free_reclaim_complete_data(void *data)
+{
+	struct nfs4_reclaim_complete_data *calldata = data;
+
+	kfree(calldata);
+}
+
+static const struct rpc_call_ops nfs4_reclaim_complete_call_ops = {
+	.rpc_call_prepare = nfs4_reclaim_complete_prepare,
+	.rpc_call_done = nfs4_reclaim_complete_done,
+	.rpc_release = nfs4_free_reclaim_complete_data,
+};
+
+/*
+ * Issue a global reclaim complete.
+ */
+static int nfs41_proc_reclaim_complete(struct nfs_client *clp,
+		const struct cred *cred)
+{
+	struct nfs4_reclaim_complete_data *calldata;
+	struct rpc_message msg = {
+		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_RECLAIM_COMPLETE],
+		.rpc_cred = cred,
+	};
+	struct rpc_task_setup task_setup_data = {
+		.rpc_client = clp->cl_rpcclient,
+		.rpc_message = &msg,
+		.callback_ops = &nfs4_reclaim_complete_call_ops,
+		.flags = RPC_TASK_NO_ROUND_ROBIN,
+	};
+	int status = -ENOMEM;
+
+	dprintk("--> %s\n", __func__);
+	calldata = kzalloc(sizeof(*calldata), GFP_NOFS);
+	if (calldata == NULL)
+		goto out;
+	calldata->clp = clp;
+	calldata->arg.one_fs = 0;
+
+	nfs4_init_sequence(&calldata->arg.seq_args, &calldata->res.seq_res, 0, 1);
+	msg.rpc_argp = &calldata->arg;
+	msg.rpc_resp = &calldata->res;
+	task_setup_data.callback_data = calldata;
+	status = nfs4_call_sync_custom(&task_setup_data);
+out:
+	dprintk("<-- %s status=%d\n", __func__, status);
+	return status;
+}
+
+static void
+nfs4_layoutget_prepare(struct rpc_task *task, void *calldata)
+{
+	struct nfs4_layoutget *lgp = calldata;
+	struct nfs_server *server = NFS_SERVER(lgp->args.inode);
+
+	dprintk("--> %s\n", __func__);
+	nfs4_setup_sequence(server->nfs_client, &lgp->args.seq_args,
+				&lgp->res.seq_res, task);
+	dprintk("<-- %s\n", __func__);
+}
+
+static void nfs4_layoutget_done(struct rpc_task *task, void *calldata)
+{
+	struct nfs4_layoutget *lgp = calldata;
+
+	dprintk("--> %s\n", __func__);
+	nfs41_sequence_process(task, &lgp->res.seq_res);
+	dprintk("<-- %s\n", __func__);
+}
+
+static int
+nfs4_layoutget_handle_exception(struct rpc_task *task,
+		struct nfs4_layoutget *lgp, struct nfs4_exception *exception)
+{
+	struct inode *inode = lgp->args.inode;
+	struct nfs_server *server = NFS_SERVER(inode);
+	struct pnfs_layout_hdr *lo;
+	int nfs4err = task->tk_status;
+	int err, status = 0;
+	LIST_HEAD(head);
+
+	dprintk("--> %s tk_status => %d\n", __func__, -task->tk_status);
+
+	nfs4_sequence_free_slot(&lgp->res.seq_res);
+
+	switch (nfs4err) {
+	case 0:
+		goto out;
+
+	/*
+	 * NFS4ERR_LAYOUTUNAVAILABLE means we are not supposed to use pnfs
+	 * on the file. set tk_status to -ENODATA to tell upper layer to
+	 * retry go inband.
+	 */
+	case -NFS4ERR_LAYOUTUNAVAILABLE:
+		status = -ENODATA;
+		goto out;
+	/*
+	 * NFS4ERR_BADLAYOUT means the MDS cannot return a layout of
+	 * length lgp->args.minlength != 0 (see RFC5661 section 18.43.3).
+	 */
+	case -NFS4ERR_BADLAYOUT:
+		status = -EOVERFLOW;
+		goto out;
+	/*
+	 * NFS4ERR_LAYOUTTRYLATER is a conflict with another client
+	 * (or clients) writing to the same RAID stripe except when
+	 * the minlength argument is 0 (see RFC5661 section 18.43.3).
+	 *
+	 * Treat it like we would RECALLCONFLICT -- we retry for a little
+	 * while, and then eventually give up.
+	 */
+	case -NFS4ERR_LAYOUTTRYLATER:
+		if (lgp->args.minlength == 0) {
+			status = -EOVERFLOW;
+			goto out;
+		}
+		status = -EBUSY;
+		break;
+	case -NFS4ERR_RECALLCONFLICT:
+	case -NFS4ERR_RETURNCONFLICT:
+		status = -ERECALLCONFLICT;
+		break;
+	case -NFS4ERR_DELEG_REVOKED:
+	case -NFS4ERR_ADMIN_REVOKED:
+	case -NFS4ERR_EXPIRED:
+	case -NFS4ERR_BAD_STATEID:
+		exception->timeout = 0;
+		spin_lock(&inode->i_lock);
+		lo = NFS_I(inode)->layout;
+		/* If the open stateid was bad, then recover it. */
+		if (!lo || test_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags) ||
+		    !nfs4_stateid_match_other(&lgp->args.stateid, &lo->plh_stateid)) {
+			spin_unlock(&inode->i_lock);
+			exception->state = lgp->args.ctx->state;
+			exception->stateid = &lgp->args.stateid;
+			break;
+		}
+
+		/*
+		 * Mark the bad layout state as invalid, then retry
+		 */
+		pnfs_mark_layout_stateid_invalid(lo, &head);
+		spin_unlock(&inode->i_lock);
+		nfs_commit_inode(inode, 0);
+		pnfs_free_lseg_list(&head);
+		status = -EAGAIN;
+		goto out;
+	}
+
+	err = nfs4_handle_exception(server, nfs4err, exception);
+	if (!status) {
+		if (exception->retry)
+			status = -EAGAIN;
+		else
+			status = err;
+	}
+out:
+	dprintk("<-- %s\n", __func__);
+	return status;
+}
+
+size_t max_response_pages(struct nfs_server *server)
+{
+	u32 max_resp_sz = server->nfs_client->cl_session->fc_attrs.max_resp_sz;
+	return nfs_page_array_len(0, max_resp_sz);
+}
+
+static void nfs4_layoutget_release(void *calldata)
+{
+	struct nfs4_layoutget *lgp = calldata;
+
+	dprintk("--> %s\n", __func__);
+	nfs4_sequence_free_slot(&lgp->res.seq_res);
+	pnfs_layoutget_free(lgp);
+	dprintk("<-- %s\n", __func__);
+}
+
+static const struct rpc_call_ops nfs4_layoutget_call_ops = {
+	.rpc_call_prepare = nfs4_layoutget_prepare,
+	.rpc_call_done = nfs4_layoutget_done,
+	.rpc_release = nfs4_layoutget_release,
+};
+
+struct pnfs_layout_segment *
+nfs4_proc_layoutget(struct nfs4_layoutget *lgp, long *timeout)
+{
+	struct inode *inode = lgp->args.inode;
+	struct nfs_server *server = NFS_SERVER(inode);
+	struct rpc_task *task;
+	struct rpc_message msg = {
+		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_LAYOUTGET],
+		.rpc_argp = &lgp->args,
+		.rpc_resp = &lgp->res,
+		.rpc_cred = lgp->cred,
+	};
+	struct rpc_task_setup task_setup_data = {
+		.rpc_client = server->client,
+		.rpc_message = &msg,
+		.callback_ops = &nfs4_layoutget_call_ops,
+		.callback_data = lgp,
+		.flags = RPC_TASK_ASYNC | RPC_TASK_CRED_NOREF,
+	};
+	struct pnfs_layout_segment *lseg = NULL;
+	struct nfs4_exception exception = {
+		.inode = inode,
+		.timeout = *timeout,
+	};
+	int status = 0;
+
+	dprintk("--> %s\n", __func__);
+
+	/* nfs4_layoutget_release calls pnfs_put_layout_hdr */
+	pnfs_get_layout_hdr(NFS_I(inode)->layout);
+
+	nfs4_init_sequence(&lgp->args.seq_args, &lgp->res.seq_res, 0, 0);
+
+	task = rpc_run_task(&task_setup_data);
+
+	status = rpc_wait_for_completion_task(task);
+	if (status != 0)
+		goto out;
+
+	if (task->tk_status < 0) {
+		status = nfs4_layoutget_handle_exception(task, lgp, &exception);
+		*timeout = exception.timeout;
+	} else if (lgp->res.layoutp->len == 0) {
+		status = -EAGAIN;
+		*timeout = nfs4_update_delay(&exception.timeout);
+	} else
+		lseg = pnfs_layout_process(lgp);
+out:
+	trace_nfs4_layoutget(lgp->args.ctx,
+			&lgp->args.range,
+			&lgp->res.range,
+			&lgp->res.stateid,
+			status);
+
+	rpc_put_task(task);
+	dprintk("<-- %s status=%d\n", __func__, status);
+	if (status)
+		return ERR_PTR(status);
+	return lseg;
+}
+
+static void
+nfs4_layoutreturn_prepare(struct rpc_task *task, void *calldata)
+{
+	struct nfs4_layoutreturn *lrp = calldata;
+
+	dprintk("--> %s\n", __func__);
+	nfs4_setup_sequence(lrp->clp,
+			&lrp->args.seq_args,
+			&lrp->res.seq_res,
+			task);
+	if (!pnfs_layout_is_valid(lrp->args.layout))
+		rpc_exit(task, 0);
+}
+
+static void nfs4_layoutreturn_done(struct rpc_task *task, void *calldata)
+{
+	struct nfs4_layoutreturn *lrp = calldata;
+	struct nfs_server *server;
+
+	dprintk("--> %s\n", __func__);
+
+	if (!nfs41_sequence_process(task, &lrp->res.seq_res))
+		return;
+
+	/*
+	 * Was there an RPC level error? Assume the call succeeded,
+	 * and that we need to release the layout
+	 */
+	if (task->tk_rpc_status != 0 && RPC_WAS_SENT(task)) {
+		lrp->res.lrs_present = 0;
+		return;
+	}
+
+	server = NFS_SERVER(lrp->args.inode);
+	switch (task->tk_status) {
+	case -NFS4ERR_OLD_STATEID:
+		if (nfs4_layout_refresh_old_stateid(&lrp->args.stateid,
+					&lrp->args.range,
+					lrp->args.inode))
+			goto out_restart;
+		fallthrough;
+	default:
+		task->tk_status = 0;
+		fallthrough;
+	case 0:
+		break;
+	case -NFS4ERR_DELAY:
+		if (nfs4_async_handle_error(task, server, NULL, NULL) != -EAGAIN)
+			break;
+		goto out_restart;
+	}
+	dprintk("<-- %s\n", __func__);
+	return;
+out_restart:
+	task->tk_status = 0;
+	nfs4_sequence_free_slot(&lrp->res.seq_res);
+	rpc_restart_call_prepare(task);
+}
+
+static void nfs4_layoutreturn_release(void *calldata)
+{
+	struct nfs4_layoutreturn *lrp = calldata;
+	struct pnfs_layout_hdr *lo = lrp->args.layout;
+
+	dprintk("--> %s\n", __func__);
+	pnfs_layoutreturn_free_lsegs(lo, &lrp->args.stateid, &lrp->args.range,
+			lrp->res.lrs_present ? &lrp->res.stateid : NULL);
+	nfs4_sequence_free_slot(&lrp->res.seq_res);
+	if (lrp->ld_private.ops && lrp->ld_private.ops->free)
+		lrp->ld_private.ops->free(&lrp->ld_private);
+	pnfs_put_layout_hdr(lrp->args.layout);
+	nfs_iput_and_deactive(lrp->inode);
+	put_cred(lrp->cred);
+	kfree(calldata);
+	dprintk("<-- %s\n", __func__);
+}
+
+static const struct rpc_call_ops nfs4_layoutreturn_call_ops = {
+	.rpc_call_prepare = nfs4_layoutreturn_prepare,
+	.rpc_call_done = nfs4_layoutreturn_done,
+	.rpc_release = nfs4_layoutreturn_release,
+};
+
+int nfs4_proc_layoutreturn(struct nfs4_layoutreturn *lrp, bool sync)
+{
+	struct rpc_task *task;
+	struct rpc_message msg = {
+		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_LAYOUTRETURN],
+		.rpc_argp = &lrp->args,
+		.rpc_resp = &lrp->res,
+		.rpc_cred = lrp->cred,
+	};
+	struct rpc_task_setup task_setup_data = {
+		.rpc_client = NFS_SERVER(lrp->args.inode)->client,
+		.rpc_message = &msg,
+		.callback_ops = &nfs4_layoutreturn_call_ops,
+		.callback_data = lrp,
+	};
+	int status = 0;
+
+	nfs4_state_protect(NFS_SERVER(lrp->args.inode)->nfs_client,
+			NFS_SP4_MACH_CRED_PNFS_CLEANUP,
+			&task_setup_data.rpc_client, &msg);
+
+	dprintk("--> %s\n", __func__);
+	lrp->inode = nfs_igrab_and_active(lrp->args.inode);
+	if (!sync) {
+		if (!lrp->inode) {
+			nfs4_layoutreturn_release(lrp);
+			return -EAGAIN;
+		}
+		task_setup_data.flags |= RPC_TASK_ASYNC;
+	}
+	if (!lrp->inode)
+		nfs4_init_sequence(&lrp->args.seq_args, &lrp->res.seq_res, 1,
+				   1);
+	else
+		nfs4_init_sequence(&lrp->args.seq_args, &lrp->res.seq_res, 1,
+				   0);
+	task = rpc_run_task(&task_setup_data);
+	if (IS_ERR(task))
+		return PTR_ERR(task);
+	if (sync)
+		status = task->tk_status;
+	trace_nfs4_layoutreturn(lrp->args.inode, &lrp->args.stateid, status);
+	dprintk("<-- %s status=%d\n", __func__, status);
+	rpc_put_task(task);
+	return status;
+}
+
+static int
+_nfs4_proc_getdeviceinfo(struct nfs_server *server,
+		struct pnfs_device *pdev,
+		const struct cred *cred)
+{
+	struct nfs4_getdeviceinfo_args args = {
+		.pdev = pdev,
+		.notify_types = NOTIFY_DEVICEID4_CHANGE |
+			NOTIFY_DEVICEID4_DELETE,
+	};
+	struct nfs4_getdeviceinfo_res res = {
+		.pdev = pdev,
+	};
+	struct rpc_message msg = {
+		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_GETDEVICEINFO],
+		.rpc_argp = &args,
+		.rpc_resp = &res,
+		.rpc_cred = cred,
+	};
+	int status;
+
+	dprintk("--> %s\n", __func__);
+	status = nfs4_call_sync(server->client, server, &msg, &args.seq_args, &res.seq_res, 0);
+	if (res.notification & ~args.notify_types)
+		dprintk("%s: unsupported notification\n", __func__);
+	if (res.notification != args.notify_types)
+		pdev->nocache = 1;
+
+	dprintk("<-- %s status=%d\n", __func__, status);
+
+	return status;
+}
+
+int nfs4_proc_getdeviceinfo(struct nfs_server *server,
+		struct pnfs_device *pdev,
+		const struct cred *cred)
+{
+	struct nfs4_exception exception = { };
+	int err;
+
+	do {
+		err = nfs4_handle_exception(server,
+					_nfs4_proc_getdeviceinfo(server, pdev, cred),
+					&exception);
+	} while (exception.retry);
+	return err;
+}
+EXPORT_SYMBOL_GPL(nfs4_proc_getdeviceinfo);
+
+static void nfs4_layoutcommit_prepare(struct rpc_task *task, void *calldata)
+{
+	struct nfs4_layoutcommit_data *data = calldata;
+	struct nfs_server *server = NFS_SERVER(data->args.inode);
+
+	nfs4_setup_sequence(server->nfs_client,
+			&data->args.seq_args,
+			&data->res.seq_res,
+			task);
+}
+
+static void
+nfs4_layoutcommit_done(struct rpc_task *task, void *calldata)
+{
+	struct nfs4_layoutcommit_data *data = calldata;
+	struct nfs_server *server = NFS_SERVER(data->args.inode);
+
+	if (!nfs41_sequence_done(task, &data->res.seq_res))
+		return;
+
+	switch (task->tk_status) { /* Just ignore these failures */
+	case -NFS4ERR_DELEG_REVOKED: /* layout was recalled */
+	case -NFS4ERR_BADIOMODE:     /* no IOMODE_RW layout for range */
+	case -NFS4ERR_BADLAYOUT:     /* no layout */
+	case -NFS4ERR_GRACE:	    /* loca_recalim always false */
+		task->tk_status = 0;
+	case 0:
+		break;
+	default:
+		if (nfs4_async_handle_error(task, server, NULL, NULL) == -EAGAIN) {
+			rpc_restart_call_prepare(task);
+			return;
+		}
+	}
+}
+
+static void nfs4_layoutcommit_release(void *calldata)
+{
+	struct nfs4_layoutcommit_data *data = calldata;
+
+	pnfs_cleanup_layoutcommit(data);
+	nfs_post_op_update_inode_force_wcc(data->args.inode,
+					   data->res.fattr);
+	put_cred(data->cred);
+	nfs_iput_and_deactive(data->inode);
+	kfree(data);
+}
+
+static const struct rpc_call_ops nfs4_layoutcommit_ops = {
+	.rpc_call_prepare = nfs4_layoutcommit_prepare,
+	.rpc_call_done = nfs4_layoutcommit_done,
+	.rpc_release = nfs4_layoutcommit_release,
+};
+
+int
+nfs4_proc_layoutcommit(struct nfs4_layoutcommit_data *data, bool sync)
+{
+	struct rpc_message msg = {
+		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_LAYOUTCOMMIT],
+		.rpc_argp = &data->args,
+		.rpc_resp = &data->res,
+		.rpc_cred = data->cred,
+	};
+	struct rpc_task_setup task_setup_data = {
+		.task = &data->task,
+		.rpc_client = NFS_CLIENT(data->args.inode),
+		.rpc_message = &msg,
+		.callback_ops = &nfs4_layoutcommit_ops,
+		.callback_data = data,
+	};
+	struct rpc_task *task;
+	int status = 0;
+
+	dprintk("NFS: initiating layoutcommit call. sync %d "
+		"lbw: %llu inode %lu\n", sync,
+		data->args.lastbytewritten,
+		data->args.inode->i_ino);
+
+	if (!sync) {
+		data->inode = nfs_igrab_and_active(data->args.inode);
+		if (data->inode == NULL) {
+			nfs4_layoutcommit_release(data);
+			return -EAGAIN;
+		}
+		task_setup_data.flags = RPC_TASK_ASYNC;
+	}
+	nfs4_init_sequence(&data->args.seq_args, &data->res.seq_res, 1, 0);
+	task = rpc_run_task(&task_setup_data);
+	if (IS_ERR(task))
+		return PTR_ERR(task);
+	if (sync)
+		status = task->tk_status;
+	trace_nfs4_layoutcommit(data->args.inode, &data->args.stateid, status);
+	dprintk("%s: status %d\n", __func__, status);
+	rpc_put_task(task);
+	return status;
+}
+
+/*
+ * Use the state managment nfs_client cl_rpcclient, which uses krb5i (if
+ * possible) as per RFC3530bis and RFC5661 Security Considerations sections
+ */
+static int
+_nfs41_proc_secinfo_no_name(struct nfs_server *server, struct nfs_fh *fhandle,
+		    struct nfs_fsinfo *info,
+		    struct nfs4_secinfo_flavors *flavors, bool use_integrity)
+{
+	struct nfs41_secinfo_no_name_args args = {
+		.style = SECINFO_STYLE_CURRENT_FH,
+	};
+	struct nfs4_secinfo_res res = {
+		.flavors = flavors,
+	};
+	struct rpc_message msg = {
+		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_SECINFO_NO_NAME],
+		.rpc_argp = &args,
+		.rpc_resp = &res,
+	};
+	struct nfs4_call_sync_data data = {
+		.seq_server = server,
+		.seq_args = &args.seq_args,
+		.seq_res = &res.seq_res,
+	};
+	struct rpc_task_setup task_setup = {
+		.rpc_client = server->client,
+		.rpc_message = &msg,
+		.callback_ops = server->nfs_client->cl_mvops->call_sync_ops,
+		.callback_data = &data,
+		.flags = RPC_TASK_NO_ROUND_ROBIN,
+	};
+	const struct cred *cred = NULL;
+	int status;
+
+	if (use_integrity) {
+		task_setup.rpc_client = server->nfs_client->cl_rpcclient;
+
+		cred = nfs4_get_clid_cred(server->nfs_client);
+		msg.rpc_cred = cred;
+	}
+
+	dprintk("--> %s\n", __func__);
+	nfs4_init_sequence(&args.seq_args, &res.seq_res, 0, 0);
+	status = nfs4_call_sync_custom(&task_setup);
+	dprintk("<-- %s status=%d\n", __func__, status);
+
+	put_cred(cred);
+
+	return status;
+}
+
+static int
+nfs41_proc_secinfo_no_name(struct nfs_server *server, struct nfs_fh *fhandle,
+			   struct nfs_fsinfo *info, struct nfs4_secinfo_flavors *flavors)
+{
+	struct nfs4_exception exception = {
+		.interruptible = true,
+	};
+	int err;
+	do {
+		/* first try using integrity protection */
+		err = -NFS4ERR_WRONGSEC;
+
+		/* try to use integrity protection with machine cred */
+		if (_nfs4_is_integrity_protected(server->nfs_client))
+			err = _nfs41_proc_secinfo_no_name(server, fhandle, info,
+							  flavors, true);
+
+		/*
+		 * if unable to use integrity protection, or SECINFO with
+		 * integrity protection returns NFS4ERR_WRONGSEC (which is
+		 * disallowed by spec, but exists in deployed servers) use
+		 * the current filesystem's rpc_client and the user cred.
+		 */
+		if (err == -NFS4ERR_WRONGSEC)
+			err = _nfs41_proc_secinfo_no_name(server, fhandle, info,
+							  flavors, false);
+
+		switch (err) {
+		case 0:
+		case -NFS4ERR_WRONGSEC:
+		case -ENOTSUPP:
+			goto out;
+		default:
+			err = nfs4_handle_exception(server, err, &exception);
+		}
+	} while (exception.retry);
+out:
+	return err;
+}
+
+static int
+nfs41_find_root_sec(struct nfs_server *server, struct nfs_fh *fhandle,
+		    struct nfs_fsinfo *info)
+{
+	int err;
+	struct page *page;
+	rpc_authflavor_t flavor = RPC_AUTH_MAXFLAVOR;
+	struct nfs4_secinfo_flavors *flavors;
+	struct nfs4_secinfo4 *secinfo;
+	int i;
+
+	page = alloc_page(GFP_KERNEL);
+	if (!page) {
+		err = -ENOMEM;
+		goto out;
+	}
+
+	flavors = page_address(page);
+	err = nfs41_proc_secinfo_no_name(server, fhandle, info, flavors);
+
+	/*
+	 * Fall back on "guess and check" method if
+	 * the server doesn't support SECINFO_NO_NAME
+	 */
+	if (err == -NFS4ERR_WRONGSEC || err == -ENOTSUPP) {
+		err = nfs4_find_root_sec(server, fhandle, info);
+		goto out_freepage;
+	}
+	if (err)
+		goto out_freepage;
+
+	for (i = 0; i < flavors->num_flavors; i++) {
+		secinfo = &flavors->flavors[i];
+
+		switch (secinfo->flavor) {
+		case RPC_AUTH_NULL:
+		case RPC_AUTH_UNIX:
+		case RPC_AUTH_GSS:
+			flavor = rpcauth_get_pseudoflavor(secinfo->flavor,
+					&secinfo->flavor_info);
+			break;
+		default:
+			flavor = RPC_AUTH_MAXFLAVOR;
+			break;
+		}
+
+		if (!nfs_auth_info_match(&server->auth_info, flavor))
+			flavor = RPC_AUTH_MAXFLAVOR;
+
+		if (flavor != RPC_AUTH_MAXFLAVOR) {
+			err = nfs4_lookup_root_sec(server, fhandle,
+						   info, flavor);
+			if (!err)
+				break;
+		}
+	}
+
+	if (flavor == RPC_AUTH_MAXFLAVOR)
+		err = -EPERM;
+
+out_freepage:
+	put_page(page);
+	if (err == -EACCES)
+		return -EPERM;
+out:
+	return err;
+}
+
+static int _nfs41_test_stateid(struct nfs_server *server,
+		nfs4_stateid *stateid,
+		const struct cred *cred)
+{
+	int status;
+	struct nfs41_test_stateid_args args = {
+		.stateid = stateid,
+	};
+	struct nfs41_test_stateid_res res;
+	struct rpc_message msg = {
+		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_TEST_STATEID],
+		.rpc_argp = &args,
+		.rpc_resp = &res,
+		.rpc_cred = cred,
+	};
+	struct rpc_clnt *rpc_client = server->client;
+
+	nfs4_state_protect(server->nfs_client, NFS_SP4_MACH_CRED_STATEID,
+		&rpc_client, &msg);
+
+	dprintk("NFS call  test_stateid %p\n", stateid);
+	nfs4_init_sequence(&args.seq_args, &res.seq_res, 0, 1);
+	status = nfs4_call_sync_sequence(rpc_client, server, &msg,
+			&args.seq_args, &res.seq_res);
+	if (status != NFS_OK) {
+		dprintk("NFS reply test_stateid: failed, %d\n", status);
+		return status;
+	}
+	dprintk("NFS reply test_stateid: succeeded, %d\n", -res.status);
+	return -res.status;
+}
+
+static void nfs4_handle_delay_or_session_error(struct nfs_server *server,
+		int err, struct nfs4_exception *exception)
+{
+	exception->retry = 0;
+	switch(err) {
+	case -NFS4ERR_DELAY:
+	case -NFS4ERR_RETRY_UNCACHED_REP:
+		nfs4_handle_exception(server, err, exception);
+		break;
+	case -NFS4ERR_BADSESSION:
+	case -NFS4ERR_BADSLOT:
+	case -NFS4ERR_BAD_HIGH_SLOT:
+	case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
+	case -NFS4ERR_DEADSESSION:
+		nfs4_do_handle_exception(server, err, exception);
+	}
+}
+
+/**
+ * nfs41_test_stateid - perform a TEST_STATEID operation
+ *
+ * @server: server / transport on which to perform the operation
+ * @stateid: state ID to test
+ * @cred: credential
+ *
+ * Returns NFS_OK if the server recognizes that "stateid" is valid.
+ * Otherwise a negative NFS4ERR value is returned if the operation
+ * failed or the state ID is not currently valid.
+ */
+static int nfs41_test_stateid(struct nfs_server *server,
+		nfs4_stateid *stateid,
+		const struct cred *cred)
+{
+	struct nfs4_exception exception = {
+		.interruptible = true,
+	};
+	int err;
+	do {
+		err = _nfs41_test_stateid(server, stateid, cred);
+		nfs4_handle_delay_or_session_error(server, err, &exception);
+	} while (exception.retry);
+	return err;
+}
+
+struct nfs_free_stateid_data {
+	struct nfs_server *server;
+	struct nfs41_free_stateid_args args;
+	struct nfs41_free_stateid_res res;
+};
+
+static void nfs41_free_stateid_prepare(struct rpc_task *task, void *calldata)
+{
+	struct nfs_free_stateid_data *data = calldata;
+	nfs4_setup_sequence(data->server->nfs_client,
+			&data->args.seq_args,
+			&data->res.seq_res,
+			task);
+}
+
+static void nfs41_free_stateid_done(struct rpc_task *task, void *calldata)
+{
+	struct nfs_free_stateid_data *data = calldata;
+
+	nfs41_sequence_done(task, &data->res.seq_res);
+
+	switch (task->tk_status) {
+	case -NFS4ERR_DELAY:
+		if (nfs4_async_handle_error(task, data->server, NULL, NULL) == -EAGAIN)
+			rpc_restart_call_prepare(task);
+	}
+}
+
+static void nfs41_free_stateid_release(void *calldata)
+{
+	kfree(calldata);
+}
+
+static const struct rpc_call_ops nfs41_free_stateid_ops = {
+	.rpc_call_prepare = nfs41_free_stateid_prepare,
+	.rpc_call_done = nfs41_free_stateid_done,
+	.rpc_release = nfs41_free_stateid_release,
+};
+
+/**
+ * nfs41_free_stateid - perform a FREE_STATEID operation
+ *
+ * @server: server / transport on which to perform the operation
+ * @stateid: state ID to release
+ * @cred: credential
+ * @privileged: set to true if this call needs to be privileged
+ *
+ * Note: this function is always asynchronous.
+ */
+static int nfs41_free_stateid(struct nfs_server *server,
+		const nfs4_stateid *stateid,
+		const struct cred *cred,
+		bool privileged)
+{
+	struct rpc_message msg = {
+		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_FREE_STATEID],
+		.rpc_cred = cred,
+	};
+	struct rpc_task_setup task_setup = {
+		.rpc_client = server->client,
+		.rpc_message = &msg,
+		.callback_ops = &nfs41_free_stateid_ops,
+		.flags = RPC_TASK_ASYNC,
+	};
+	struct nfs_free_stateid_data *data;
+	struct rpc_task *task;
+
+	nfs4_state_protect(server->nfs_client, NFS_SP4_MACH_CRED_STATEID,
+		&task_setup.rpc_client, &msg);
+
+	dprintk("NFS call  free_stateid %p\n", stateid);
+	data = kmalloc(sizeof(*data), GFP_NOFS);
+	if (!data)
+		return -ENOMEM;
+	data->server = server;
+	nfs4_stateid_copy(&data->args.stateid, stateid);
+
+	task_setup.callback_data = data;
+
+	msg.rpc_argp = &data->args;
+	msg.rpc_resp = &data->res;
+	nfs4_init_sequence(&data->args.seq_args, &data->res.seq_res, 1, privileged);
+	task = rpc_run_task(&task_setup);
+	if (IS_ERR(task))
+		return PTR_ERR(task);
+	rpc_put_task(task);
+	return 0;
+}
+
+static void
+nfs41_free_lock_state(struct nfs_server *server, struct nfs4_lock_state *lsp)
+{
+	const struct cred *cred = lsp->ls_state->owner->so_cred;
+
+	nfs41_free_stateid(server, &lsp->ls_stateid, cred, false);
+	nfs4_free_lock_state(server, lsp);
+}
+
+static bool nfs41_match_stateid(const nfs4_stateid *s1,
+		const nfs4_stateid *s2)
+{
+	if (s1->type != s2->type)
+		return false;
+
+	if (memcmp(s1->other, s2->other, sizeof(s1->other)) != 0)
+		return false;
+
+	if (s1->seqid == s2->seqid)
+		return true;
+
+	return s1->seqid == 0 || s2->seqid == 0;
+}
+
+#endif /* CONFIG_NFS_V4_1 */
+
+static bool nfs4_match_stateid(const nfs4_stateid *s1,
+		const nfs4_stateid *s2)
+{
+	return nfs4_stateid_match(s1, s2);
+}
+
+
+static const struct nfs4_state_recovery_ops nfs40_reboot_recovery_ops = {
+	.owner_flag_bit = NFS_OWNER_RECLAIM_REBOOT,
+	.state_flag_bit	= NFS_STATE_RECLAIM_REBOOT,
+	.recover_open	= nfs4_open_reclaim,
+	.recover_lock	= nfs4_lock_reclaim,
+	.establish_clid = nfs4_init_clientid,
+	.detect_trunking = nfs40_discover_server_trunking,
+};
+
+#if defined(CONFIG_NFS_V4_1)
+static const struct nfs4_state_recovery_ops nfs41_reboot_recovery_ops = {
+	.owner_flag_bit = NFS_OWNER_RECLAIM_REBOOT,
+	.state_flag_bit	= NFS_STATE_RECLAIM_REBOOT,
+	.recover_open	= nfs4_open_reclaim,
+	.recover_lock	= nfs4_lock_reclaim,
+	.establish_clid = nfs41_init_clientid,
+	.reclaim_complete = nfs41_proc_reclaim_complete,
+	.detect_trunking = nfs41_discover_server_trunking,
+};
+#endif /* CONFIG_NFS_V4_1 */
+
+static const struct nfs4_state_recovery_ops nfs40_nograce_recovery_ops = {
+	.owner_flag_bit = NFS_OWNER_RECLAIM_NOGRACE,
+	.state_flag_bit	= NFS_STATE_RECLAIM_NOGRACE,
+	.recover_open	= nfs40_open_expired,
+	.recover_lock	= nfs4_lock_expired,
+	.establish_clid = nfs4_init_clientid,
+};
+
+#if defined(CONFIG_NFS_V4_1)
+static const struct nfs4_state_recovery_ops nfs41_nograce_recovery_ops = {
+	.owner_flag_bit = NFS_OWNER_RECLAIM_NOGRACE,
+	.state_flag_bit	= NFS_STATE_RECLAIM_NOGRACE,
+	.recover_open	= nfs41_open_expired,
+	.recover_lock	= nfs41_lock_expired,
+	.establish_clid = nfs41_init_clientid,
+};
+#endif /* CONFIG_NFS_V4_1 */
+
+static const struct nfs4_state_maintenance_ops nfs40_state_renewal_ops = {
+	.sched_state_renewal = nfs4_proc_async_renew,
+	.get_state_renewal_cred = nfs4_get_renew_cred,
+	.renew_lease = nfs4_proc_renew,
+};
+
+#if defined(CONFIG_NFS_V4_1)
+static const struct nfs4_state_maintenance_ops nfs41_state_renewal_ops = {
+	.sched_state_renewal = nfs41_proc_async_sequence,
+	.get_state_renewal_cred = nfs4_get_machine_cred,
+	.renew_lease = nfs4_proc_sequence,
+};
+#endif
+
+static const struct nfs4_mig_recovery_ops nfs40_mig_recovery_ops = {
+	.get_locations = _nfs40_proc_get_locations,
+	.fsid_present = _nfs40_proc_fsid_present,
+};
+
+#if defined(CONFIG_NFS_V4_1)
+static const struct nfs4_mig_recovery_ops nfs41_mig_recovery_ops = {
+	.get_locations = _nfs41_proc_get_locations,
+	.fsid_present = _nfs41_proc_fsid_present,
+};
+#endif	/* CONFIG_NFS_V4_1 */
+
+static const struct nfs4_minor_version_ops nfs_v4_0_minor_ops = {
+	.minor_version = 0,
+	.init_caps = NFS_CAP_READDIRPLUS
+		| NFS_CAP_ATOMIC_OPEN
+		| NFS_CAP_POSIX_LOCK,
+	.init_client = nfs40_init_client,
+	.shutdown_client = nfs40_shutdown_client,
+	.match_stateid = nfs4_match_stateid,
+	.find_root_sec = nfs4_find_root_sec,
+	.free_lock_state = nfs4_release_lockowner,
+	.test_and_free_expired = nfs40_test_and_free_expired_stateid,
+	.alloc_seqid = nfs_alloc_seqid,
+	.call_sync_ops = &nfs40_call_sync_ops,
+	.reboot_recovery_ops = &nfs40_reboot_recovery_ops,
+	.nograce_recovery_ops = &nfs40_nograce_recovery_ops,
+	.state_renewal_ops = &nfs40_state_renewal_ops,
+	.mig_recovery_ops = &nfs40_mig_recovery_ops,
+};
+
+#if defined(CONFIG_NFS_V4_1)
+static struct nfs_seqid *
+nfs_alloc_no_seqid(struct nfs_seqid_counter *arg1, gfp_t arg2)
+{
+	return NULL;
+}
+
+static const struct nfs4_minor_version_ops nfs_v4_1_minor_ops = {
+	.minor_version = 1,
+	.init_caps = NFS_CAP_READDIRPLUS
+		| NFS_CAP_ATOMIC_OPEN
+		| NFS_CAP_POSIX_LOCK
+		| NFS_CAP_STATEID_NFSV41
+		| NFS_CAP_ATOMIC_OPEN_V1
+		| NFS_CAP_LGOPEN,
+	.init_client = nfs41_init_client,
+	.shutdown_client = nfs41_shutdown_client,
+	.match_stateid = nfs41_match_stateid,
+	.find_root_sec = nfs41_find_root_sec,
+	.free_lock_state = nfs41_free_lock_state,
+	.test_and_free_expired = nfs41_test_and_free_expired_stateid,
+	.alloc_seqid = nfs_alloc_no_seqid,
+	.session_trunk = nfs4_test_session_trunk,
+	.call_sync_ops = &nfs41_call_sync_ops,
+	.reboot_recovery_ops = &nfs41_reboot_recovery_ops,
+	.nograce_recovery_ops = &nfs41_nograce_recovery_ops,
+	.state_renewal_ops = &nfs41_state_renewal_ops,
+	.mig_recovery_ops = &nfs41_mig_recovery_ops,
+};
+#endif
+
+#if defined(CONFIG_NFS_V4_2)
+static const struct nfs4_minor_version_ops nfs_v4_2_minor_ops = {
+	.minor_version = 2,
+	.init_caps = NFS_CAP_READDIRPLUS
+		| NFS_CAP_ATOMIC_OPEN
+		| NFS_CAP_POSIX_LOCK
+		| NFS_CAP_STATEID_NFSV41
+		| NFS_CAP_ATOMIC_OPEN_V1
+		| NFS_CAP_LGOPEN
+		| NFS_CAP_ALLOCATE
+		| NFS_CAP_COPY
+		| NFS_CAP_OFFLOAD_CANCEL
+		| NFS_CAP_COPY_NOTIFY
+		| NFS_CAP_DEALLOCATE
+		| NFS_CAP_SEEK
+		| NFS_CAP_LAYOUTSTATS
+		| NFS_CAP_CLONE
+		| NFS_CAP_LAYOUTERROR
+		| NFS_CAP_READ_PLUS,
+	.init_client = nfs41_init_client,
+	.shutdown_client = nfs41_shutdown_client,
+	.match_stateid = nfs41_match_stateid,
+	.find_root_sec = nfs41_find_root_sec,
+	.free_lock_state = nfs41_free_lock_state,
+	.call_sync_ops = &nfs41_call_sync_ops,
+	.test_and_free_expired = nfs41_test_and_free_expired_stateid,
+	.alloc_seqid = nfs_alloc_no_seqid,
+	.session_trunk = nfs4_test_session_trunk,
+	.reboot_recovery_ops = &nfs41_reboot_recovery_ops,
+	.nograce_recovery_ops = &nfs41_nograce_recovery_ops,
+	.state_renewal_ops = &nfs41_state_renewal_ops,
+	.mig_recovery_ops = &nfs41_mig_recovery_ops,
+};
+#endif
+
+const struct nfs4_minor_version_ops *nfs_v4_minor_ops[] = {
+	[0] = &nfs_v4_0_minor_ops,
+#if defined(CONFIG_NFS_V4_1)
+	[1] = &nfs_v4_1_minor_ops,
+#endif
+#if defined(CONFIG_NFS_V4_2)
+	[2] = &nfs_v4_2_minor_ops,
+#endif
+};
+
+static ssize_t nfs4_listxattr(struct dentry *dentry, char *list, size_t size)
+{
+	ssize_t error, error2, error3;
+
+	error = generic_listxattr(dentry, list, size);
+	if (error < 0)
+		return error;
+	if (list) {
+		list += error;
+		size -= error;
+	}
+
+	error2 = nfs4_listxattr_nfs4_label(d_inode(dentry), list, size);
+	if (error2 < 0)
+		return error2;
+
+	if (list) {
+		list += error2;
+		size -= error2;
+	}
+
+	error3 = nfs4_listxattr_nfs4_user(d_inode(dentry), list, size);
+	if (error3 < 0)
+		return error3;
+
+	return error + error2 + error3;
+}
+
+static void nfs4_enable_swap(struct inode *inode)
+{
+	/* The state manager thread must always be running.
+	 * It will notice the client is a swapper, and stay put.
+	 */
+	struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
+
+	nfs4_schedule_state_manager(clp);
+}
+
+static void nfs4_disable_swap(struct inode *inode)
+{
+	/* The state manager thread will now exit once it is
+	 * woken.
+	 */
+	struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
+
+	set_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state);
+	clear_bit(NFS4CLNT_MANAGER_AVAILABLE, &clp->cl_state);
+	wake_up_var(&clp->cl_state);
+}
+
+static const struct inode_operations nfs4_dir_inode_operations = {
+	.create		= nfs_create,
+	.lookup		= nfs_lookup,
+	.atomic_open	= nfs_atomic_open,
+	.link		= nfs_link,
+	.unlink		= nfs_unlink,
+	.symlink	= nfs_symlink,
+	.mkdir		= nfs_mkdir,
+	.rmdir		= nfs_rmdir,
+	.mknod		= nfs_mknod,
+	.rename		= nfs_rename,
+	.permission	= nfs_permission,
+	.getattr	= nfs_getattr,
+	.setattr	= nfs_setattr,
+	.listxattr	= nfs4_listxattr,
+};
+
+static const struct inode_operations nfs4_file_inode_operations = {
+	.permission	= nfs_permission,
+	.getattr	= nfs_getattr,
+	.setattr	= nfs_setattr,
+	.listxattr	= nfs4_listxattr,
+};
+
+const struct nfs_rpc_ops nfs_v4_clientops = {
+	.version	= 4,			/* protocol version */
+	.dentry_ops	= &nfs4_dentry_operations,
+	.dir_inode_ops	= &nfs4_dir_inode_operations,
+	.file_inode_ops	= &nfs4_file_inode_operations,
+	.file_ops	= &nfs4_file_operations,
+	.getroot	= nfs4_proc_get_root,
+	.submount	= nfs4_submount,
+	.try_get_tree	= nfs4_try_get_tree,
+	.getattr	= nfs4_proc_getattr,
+	.setattr	= nfs4_proc_setattr,
+	.lookup		= nfs4_proc_lookup,
+	.lookupp	= nfs4_proc_lookupp,
+	.access		= nfs4_proc_access,
+	.readlink	= nfs4_proc_readlink,
+	.create		= nfs4_proc_create,
+	.remove		= nfs4_proc_remove,
+	.unlink_setup	= nfs4_proc_unlink_setup,
+	.unlink_rpc_prepare = nfs4_proc_unlink_rpc_prepare,
+	.unlink_done	= nfs4_proc_unlink_done,
+	.rename_setup	= nfs4_proc_rename_setup,
+	.rename_rpc_prepare = nfs4_proc_rename_rpc_prepare,
+	.rename_done	= nfs4_proc_rename_done,
+	.link		= nfs4_proc_link,
+	.symlink	= nfs4_proc_symlink,
+	.mkdir		= nfs4_proc_mkdir,
+	.rmdir		= nfs4_proc_rmdir,
+	.readdir	= nfs4_proc_readdir,
+	.mknod		= nfs4_proc_mknod,
+	.statfs		= nfs4_proc_statfs,
+	.fsinfo		= nfs4_proc_fsinfo,
+	.pathconf	= nfs4_proc_pathconf,
+	.set_capabilities = nfs4_server_capabilities,
+	.decode_dirent	= nfs4_decode_dirent,
+	.pgio_rpc_prepare = nfs4_proc_pgio_rpc_prepare,
+	.read_setup	= nfs4_proc_read_setup,
+	.read_done	= nfs4_read_done,
+	.write_setup	= nfs4_proc_write_setup,
+	.write_done	= nfs4_write_done,
+	.commit_setup	= nfs4_proc_commit_setup,
+	.commit_rpc_prepare = nfs4_proc_commit_rpc_prepare,
+	.commit_done	= nfs4_commit_done,
+	.lock		= nfs4_proc_lock,
+	.clear_acl_cache = nfs4_zap_acl_attr,
+	.close_context  = nfs4_close_context,
+	.open_context	= nfs4_atomic_open,
+	.have_delegation = nfs4_have_delegation,
+	.alloc_client	= nfs4_alloc_client,
+	.init_client	= nfs4_init_client,
+	.free_client	= nfs4_free_client,
+	.create_server	= nfs4_create_server,
+	.clone_server	= nfs_clone_server,
+	.enable_swap	= nfs4_enable_swap,
+	.disable_swap	= nfs4_disable_swap,
+};
+
+static const struct xattr_handler nfs4_xattr_nfs4_acl_handler = {
+	.name	= XATTR_NAME_NFSV4_ACL,
+	.list	= nfs4_xattr_list_nfs4_acl,
+	.get	= nfs4_xattr_get_nfs4_acl,
+	.set	= nfs4_xattr_set_nfs4_acl,
+};
+
+#ifdef CONFIG_NFS_V4_2
+static const struct xattr_handler nfs4_xattr_nfs4_user_handler = {
+	.prefix	= XATTR_USER_PREFIX,
+	.get	= nfs4_xattr_get_nfs4_user,
+	.set	= nfs4_xattr_set_nfs4_user,
+};
+#endif
+
+const struct xattr_handler *nfs4_xattr_handlers[] = {
+	&nfs4_xattr_nfs4_acl_handler,
+#ifdef CONFIG_NFS_V4_SECURITY_LABEL
+	&nfs4_xattr_nfs4_label_handler,
+#endif
+#ifdef CONFIG_NFS_V4_2
+	&nfs4_xattr_nfs4_user_handler,
+#endif
+	NULL
+};
+
+/*
+ * Local variables:
+ *  c-basic-offset: 8
+ * End:
+ */
diff --git a/fs/nfs/nfs4renewd.c b/fs/nfs/nfs4renewd.c
new file mode 100644
index 000000000..ff876dda7
--- /dev/null
+++ b/fs/nfs/nfs4renewd.c
@@ -0,0 +1,157 @@
+/*
+ *  fs/nfs/nfs4renewd.c
+ *
+ *  Copyright (c) 2002 The Regents of the University of Michigan.
+ *  All rights reserved.
+ *
+ *  Kendrick Smith <kmsmith@umich.edu>
+ *
+ *  Redistribution and use in source and binary forms, with or without
+ *  modification, are permitted provided that the following conditions
+ *  are met:
+ *
+ *  1. Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *  2. Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *  3. Neither the name of the University nor the names of its
+ *     contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+ *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * Implementation of the NFSv4 "renew daemon", which wakes up periodically to
+ * send a RENEW, to keep state alive on the server.  The daemon is implemented
+ * as an rpc_task, not a real kernel thread, so it always runs in rpciod's
+ * context.  There is one renewd per nfs_server.
+ *
+ */
+
+#include <linux/mm.h>
+#include <linux/pagemap.h>
+#include <linux/sunrpc/sched.h>
+#include <linux/sunrpc/clnt.h>
+
+#include <linux/nfs.h>
+#include <linux/nfs4.h>
+#include <linux/nfs_fs.h>
+#include "nfs4_fs.h"
+#include "delegation.h"
+
+#define NFSDBG_FACILITY		NFSDBG_STATE
+
+void
+nfs4_renew_state(struct work_struct *work)
+{
+	const struct nfs4_state_maintenance_ops *ops;
+	struct nfs_client *clp =
+		container_of(work, struct nfs_client, cl_renewd.work);
+	const struct cred *cred;
+	long lease;
+	unsigned long last, now;
+	unsigned renew_flags = 0;
+
+	ops = clp->cl_mvops->state_renewal_ops;
+	dprintk("%s: start\n", __func__);
+
+	if (test_bit(NFS_CS_STOP_RENEW, &clp->cl_res_state))
+		goto out;
+
+	lease = clp->cl_lease_time;
+	last = clp->cl_last_renewal;
+	now = jiffies;
+	/* Are we close to a lease timeout? */
+	if (time_after(now, last + lease/3))
+		renew_flags |= NFS4_RENEW_TIMEOUT;
+	if (nfs_delegations_present(clp))
+		renew_flags |= NFS4_RENEW_DELEGATION_CB;
+
+	if (renew_flags != 0) {
+		cred = ops->get_state_renewal_cred(clp);
+		if (cred == NULL) {
+			if (!(renew_flags & NFS4_RENEW_DELEGATION_CB)) {
+				set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
+				goto out;
+			}
+			nfs_expire_all_delegations(clp);
+		} else {
+			int ret;
+
+			/* Queue an asynchronous RENEW. */
+			ret = ops->sched_state_renewal(clp, cred, renew_flags);
+			put_cred(cred);
+			switch (ret) {
+			default:
+				goto out_exp;
+			case -EAGAIN:
+			case -ENOMEM:
+				break;
+			}
+		}
+	} else {
+		dprintk("%s: failed to call renewd. Reason: lease not expired \n",
+				__func__);
+	}
+	nfs4_schedule_state_renewal(clp);
+out_exp:
+	nfs_expire_unreferenced_delegations(clp);
+out:
+	dprintk("%s: done\n", __func__);
+}
+
+void
+nfs4_schedule_state_renewal(struct nfs_client *clp)
+{
+	long timeout;
+
+	spin_lock(&clp->cl_lock);
+	timeout = (2 * clp->cl_lease_time) / 3 + (long)clp->cl_last_renewal
+		- (long)jiffies;
+	if (timeout < 5 * HZ)
+		timeout = 5 * HZ;
+	dprintk("%s: requeueing work. Lease period = %ld\n",
+			__func__, (timeout + HZ - 1) / HZ);
+	mod_delayed_work(system_wq, &clp->cl_renewd, timeout);
+	set_bit(NFS_CS_RENEWD, &clp->cl_res_state);
+	spin_unlock(&clp->cl_lock);
+}
+
+void
+nfs4_kill_renewd(struct nfs_client *clp)
+{
+	cancel_delayed_work_sync(&clp->cl_renewd);
+}
+
+/**
+ * nfs4_set_lease_period - Sets the lease period on a nfs_client
+ *
+ * @clp: pointer to nfs_client
+ * @lease: new value for lease period
+ */
+void nfs4_set_lease_period(struct nfs_client *clp,
+		unsigned long lease)
+{
+	spin_lock(&clp->cl_lock);
+	clp->cl_lease_time = lease;
+	spin_unlock(&clp->cl_lock);
+
+	/* Cap maximum reconnect timeout at 1/2 lease period */
+	rpc_set_connect_timeout(clp->cl_rpcclient, lease, lease >> 1);
+}
+
+/*
+ * Local variables:
+ *   c-basic-offset: 8
+ * End:
+ */
diff --git a/fs/nfs/nfs4session.c b/fs/nfs/nfs4session.c
new file mode 100644
index 000000000..4145a0138
--- /dev/null
+++ b/fs/nfs/nfs4session.c
@@ -0,0 +1,653 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * fs/nfs/nfs4session.c
+ *
+ * Copyright (c) 2012 Trond Myklebust <Trond.Myklebust@netapp.com>
+ *
+ */
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/printk.h>
+#include <linux/slab.h>
+#include <linux/sunrpc/sched.h>
+#include <linux/sunrpc/bc_xprt.h>
+#include <linux/nfs.h>
+#include <linux/nfs4.h>
+#include <linux/nfs_fs.h>
+#include <linux/module.h>
+
+#include "nfs4_fs.h"
+#include "internal.h"
+#include "nfs4session.h"
+#include "callback.h"
+
+#define NFSDBG_FACILITY		NFSDBG_STATE
+
+static void nfs4_init_slot_table(struct nfs4_slot_table *tbl, const char *queue)
+{
+	tbl->highest_used_slotid = NFS4_NO_SLOT;
+	spin_lock_init(&tbl->slot_tbl_lock);
+	rpc_init_priority_wait_queue(&tbl->slot_tbl_waitq, queue);
+	init_waitqueue_head(&tbl->slot_waitq);
+	init_completion(&tbl->complete);
+}
+
+/*
+ * nfs4_shrink_slot_table - free retired slots from the slot table
+ */
+static void nfs4_shrink_slot_table(struct nfs4_slot_table  *tbl, u32 newsize)
+{
+	struct nfs4_slot **p;
+	if (newsize >= tbl->max_slots)
+		return;
+
+	p = &tbl->slots;
+	while (newsize--)
+		p = &(*p)->next;
+	while (*p) {
+		struct nfs4_slot *slot = *p;
+
+		*p = slot->next;
+		kfree(slot);
+		tbl->max_slots--;
+	}
+}
+
+/**
+ * nfs4_slot_tbl_drain_complete - wake waiters when drain is complete
+ * @tbl: controlling slot table
+ *
+ */
+void nfs4_slot_tbl_drain_complete(struct nfs4_slot_table *tbl)
+{
+	if (nfs4_slot_tbl_draining(tbl))
+		complete(&tbl->complete);
+}
+
+/*
+ * nfs4_free_slot - free a slot and efficiently update slot table.
+ *
+ * freeing a slot is trivially done by clearing its respective bit
+ * in the bitmap.
+ * If the freed slotid equals highest_used_slotid we want to update it
+ * so that the server would be able to size down the slot table if needed,
+ * otherwise we know that the highest_used_slotid is still in use.
+ * When updating highest_used_slotid there may be "holes" in the bitmap
+ * so we need to scan down from highest_used_slotid to 0 looking for the now
+ * highest slotid in use.
+ * If none found, highest_used_slotid is set to NFS4_NO_SLOT.
+ *
+ * Must be called while holding tbl->slot_tbl_lock
+ */
+void nfs4_free_slot(struct nfs4_slot_table *tbl, struct nfs4_slot *slot)
+{
+	u32 slotid = slot->slot_nr;
+
+	/* clear used bit in bitmap */
+	__clear_bit(slotid, tbl->used_slots);
+
+	/* update highest_used_slotid when it is freed */
+	if (slotid == tbl->highest_used_slotid) {
+		u32 new_max = find_last_bit(tbl->used_slots, slotid);
+		if (new_max < slotid)
+			tbl->highest_used_slotid = new_max;
+		else {
+			tbl->highest_used_slotid = NFS4_NO_SLOT;
+			nfs4_slot_tbl_drain_complete(tbl);
+		}
+	}
+	dprintk("%s: slotid %u highest_used_slotid %u\n", __func__,
+		slotid, tbl->highest_used_slotid);
+}
+
+static struct nfs4_slot *nfs4_new_slot(struct nfs4_slot_table  *tbl,
+		u32 slotid, u32 seq_init, gfp_t gfp_mask)
+{
+	struct nfs4_slot *slot;
+
+	slot = kzalloc(sizeof(*slot), gfp_mask);
+	if (slot) {
+		slot->table = tbl;
+		slot->slot_nr = slotid;
+		slot->seq_nr = seq_init;
+		slot->seq_nr_highest_sent = seq_init;
+		slot->seq_nr_last_acked = seq_init - 1;
+	}
+	return slot;
+}
+
+static struct nfs4_slot *nfs4_find_or_create_slot(struct nfs4_slot_table  *tbl,
+		u32 slotid, u32 seq_init, gfp_t gfp_mask)
+{
+	struct nfs4_slot **p, *slot;
+
+	p = &tbl->slots;
+	for (;;) {
+		if (*p == NULL) {
+			*p = nfs4_new_slot(tbl, tbl->max_slots,
+					seq_init, gfp_mask);
+			if (*p == NULL)
+				break;
+			tbl->max_slots++;
+		}
+		slot = *p;
+		if (slot->slot_nr == slotid)
+			return slot;
+		p = &slot->next;
+	}
+	return ERR_PTR(-ENOMEM);
+}
+
+static void nfs4_lock_slot(struct nfs4_slot_table *tbl,
+		struct nfs4_slot *slot)
+{
+	u32 slotid = slot->slot_nr;
+
+	__set_bit(slotid, tbl->used_slots);
+	if (slotid > tbl->highest_used_slotid ||
+	    tbl->highest_used_slotid == NFS4_NO_SLOT)
+		tbl->highest_used_slotid = slotid;
+	slot->generation = tbl->generation;
+}
+
+/*
+ * nfs4_try_to_lock_slot - Given a slot try to allocate it
+ *
+ * Note: must be called with the slot_tbl_lock held.
+ */
+bool nfs4_try_to_lock_slot(struct nfs4_slot_table *tbl, struct nfs4_slot *slot)
+{
+	if (nfs4_test_locked_slot(tbl, slot->slot_nr))
+		return false;
+	nfs4_lock_slot(tbl, slot);
+	return true;
+}
+
+/*
+ * nfs4_lookup_slot - Find a slot but don't allocate it
+ *
+ * Note: must be called with the slot_tbl_lock held.
+ */
+struct nfs4_slot *nfs4_lookup_slot(struct nfs4_slot_table *tbl, u32 slotid)
+{
+	if (slotid <= tbl->max_slotid)
+		return nfs4_find_or_create_slot(tbl, slotid, 0, GFP_NOWAIT);
+	return ERR_PTR(-E2BIG);
+}
+
+static int nfs4_slot_get_seqid(struct nfs4_slot_table  *tbl, u32 slotid,
+		u32 *seq_nr)
+	__must_hold(&tbl->slot_tbl_lock)
+{
+	struct nfs4_slot *slot;
+	int ret;
+
+	slot = nfs4_lookup_slot(tbl, slotid);
+	ret = PTR_ERR_OR_ZERO(slot);
+	if (!ret)
+		*seq_nr = slot->seq_nr;
+
+	return ret;
+}
+
+/*
+ * nfs4_slot_seqid_in_use - test if a slot sequence id is still in use
+ *
+ * Given a slot table, slot id and sequence number, determine if the
+ * RPC call in question is still in flight. This function is mainly
+ * intended for use by the callback channel.
+ */
+static bool nfs4_slot_seqid_in_use(struct nfs4_slot_table *tbl,
+		u32 slotid, u32 seq_nr)
+{
+	u32 cur_seq = 0;
+	bool ret = false;
+
+	spin_lock(&tbl->slot_tbl_lock);
+	if (nfs4_slot_get_seqid(tbl, slotid, &cur_seq) == 0 &&
+	    cur_seq == seq_nr && test_bit(slotid, tbl->used_slots))
+		ret = true;
+	spin_unlock(&tbl->slot_tbl_lock);
+	return ret;
+}
+
+/*
+ * nfs4_slot_wait_on_seqid - wait until a slot sequence id is complete
+ *
+ * Given a slot table, slot id and sequence number, wait until the
+ * corresponding RPC call completes. This function is mainly
+ * intended for use by the callback channel.
+ */
+int nfs4_slot_wait_on_seqid(struct nfs4_slot_table *tbl,
+		u32 slotid, u32 seq_nr,
+		unsigned long timeout)
+{
+	if (wait_event_timeout(tbl->slot_waitq,
+			!nfs4_slot_seqid_in_use(tbl, slotid, seq_nr),
+			timeout) == 0)
+		return -ETIMEDOUT;
+	return 0;
+}
+
+/*
+ * nfs4_alloc_slot - efficiently look for a free slot
+ *
+ * nfs4_alloc_slot looks for an unset bit in the used_slots bitmap.
+ * If found, we mark the slot as used, update the highest_used_slotid,
+ * and respectively set up the sequence operation args.
+ *
+ * Note: must be called with under the slot_tbl_lock.
+ */
+struct nfs4_slot *nfs4_alloc_slot(struct nfs4_slot_table *tbl)
+{
+	struct nfs4_slot *ret = ERR_PTR(-EBUSY);
+	u32 slotid;
+
+	dprintk("--> %s used_slots=%04lx highest_used=%u max_slots=%u\n",
+		__func__, tbl->used_slots[0], tbl->highest_used_slotid,
+		tbl->max_slotid + 1);
+	slotid = find_first_zero_bit(tbl->used_slots, tbl->max_slotid + 1);
+	if (slotid <= tbl->max_slotid) {
+		ret = nfs4_find_or_create_slot(tbl, slotid, 1, GFP_NOWAIT);
+		if (!IS_ERR(ret))
+			nfs4_lock_slot(tbl, ret);
+	}
+	dprintk("<-- %s used_slots=%04lx highest_used=%u slotid=%u\n",
+		__func__, tbl->used_slots[0], tbl->highest_used_slotid,
+		!IS_ERR(ret) ? ret->slot_nr : NFS4_NO_SLOT);
+	return ret;
+}
+
+static int nfs4_grow_slot_table(struct nfs4_slot_table *tbl,
+		 u32 max_reqs, u32 ivalue)
+{
+	if (max_reqs <= tbl->max_slots)
+		return 0;
+	if (!IS_ERR(nfs4_find_or_create_slot(tbl, max_reqs - 1, ivalue, GFP_NOFS)))
+		return 0;
+	return -ENOMEM;
+}
+
+static void nfs4_reset_slot_table(struct nfs4_slot_table *tbl,
+		u32 server_highest_slotid,
+		u32 ivalue)
+{
+	struct nfs4_slot **p;
+
+	nfs4_shrink_slot_table(tbl, server_highest_slotid + 1);
+	p = &tbl->slots;
+	while (*p) {
+		(*p)->seq_nr = ivalue;
+		(*p)->seq_nr_highest_sent = ivalue;
+		(*p)->seq_nr_last_acked = ivalue - 1;
+		p = &(*p)->next;
+	}
+	tbl->highest_used_slotid = NFS4_NO_SLOT;
+	tbl->target_highest_slotid = server_highest_slotid;
+	tbl->server_highest_slotid = server_highest_slotid;
+	tbl->d_target_highest_slotid = 0;
+	tbl->d2_target_highest_slotid = 0;
+	tbl->max_slotid = server_highest_slotid;
+}
+
+/*
+ * (re)Initialise a slot table
+ */
+static int nfs4_realloc_slot_table(struct nfs4_slot_table *tbl,
+		u32 max_reqs, u32 ivalue)
+{
+	int ret;
+
+	dprintk("--> %s: max_reqs=%u, tbl->max_slots %u\n", __func__,
+		max_reqs, tbl->max_slots);
+
+	if (max_reqs > NFS4_MAX_SLOT_TABLE)
+		max_reqs = NFS4_MAX_SLOT_TABLE;
+
+	ret = nfs4_grow_slot_table(tbl, max_reqs, ivalue);
+	if (ret)
+		goto out;
+
+	spin_lock(&tbl->slot_tbl_lock);
+	nfs4_reset_slot_table(tbl, max_reqs - 1, ivalue);
+	spin_unlock(&tbl->slot_tbl_lock);
+
+	dprintk("%s: tbl=%p slots=%p max_slots=%u\n", __func__,
+		tbl, tbl->slots, tbl->max_slots);
+out:
+	dprintk("<-- %s: return %d\n", __func__, ret);
+	return ret;
+}
+
+/*
+ * nfs4_release_slot_table - release all slot table entries
+ */
+static void nfs4_release_slot_table(struct nfs4_slot_table *tbl)
+{
+	nfs4_shrink_slot_table(tbl, 0);
+}
+
+/**
+ * nfs4_shutdown_slot_table - release resources attached to a slot table
+ * @tbl: slot table to shut down
+ *
+ */
+void nfs4_shutdown_slot_table(struct nfs4_slot_table *tbl)
+{
+	nfs4_release_slot_table(tbl);
+	rpc_destroy_wait_queue(&tbl->slot_tbl_waitq);
+}
+
+/**
+ * nfs4_setup_slot_table - prepare a stand-alone slot table for use
+ * @tbl: slot table to set up
+ * @max_reqs: maximum number of requests allowed
+ * @queue: name to give RPC wait queue
+ *
+ * Returns zero on success, or a negative errno.
+ */
+int nfs4_setup_slot_table(struct nfs4_slot_table *tbl, unsigned int max_reqs,
+		const char *queue)
+{
+	nfs4_init_slot_table(tbl, queue);
+	return nfs4_realloc_slot_table(tbl, max_reqs, 0);
+}
+
+static bool nfs41_assign_slot(struct rpc_task *task, void *pslot)
+{
+	struct nfs4_sequence_args *args = task->tk_msg.rpc_argp;
+	struct nfs4_sequence_res *res = task->tk_msg.rpc_resp;
+	struct nfs4_slot *slot = pslot;
+	struct nfs4_slot_table *tbl = slot->table;
+
+	if (nfs4_slot_tbl_draining(tbl) && !args->sa_privileged)
+		return false;
+	slot->generation = tbl->generation;
+	args->sa_slot = slot;
+	res->sr_timestamp = jiffies;
+	res->sr_slot = slot;
+	res->sr_status_flags = 0;
+	res->sr_status = 1;
+	return true;
+}
+
+static bool __nfs41_wake_and_assign_slot(struct nfs4_slot_table *tbl,
+		struct nfs4_slot *slot)
+{
+	if (rpc_wake_up_first(&tbl->slot_tbl_waitq, nfs41_assign_slot, slot))
+		return true;
+	return false;
+}
+
+bool nfs41_wake_and_assign_slot(struct nfs4_slot_table *tbl,
+		struct nfs4_slot *slot)
+{
+	if (slot->slot_nr > tbl->max_slotid)
+		return false;
+	return __nfs41_wake_and_assign_slot(tbl, slot);
+}
+
+static bool nfs41_try_wake_next_slot_table_entry(struct nfs4_slot_table *tbl)
+{
+	struct nfs4_slot *slot = nfs4_alloc_slot(tbl);
+	if (!IS_ERR(slot)) {
+		bool ret = __nfs41_wake_and_assign_slot(tbl, slot);
+		if (ret)
+			return ret;
+		nfs4_free_slot(tbl, slot);
+	}
+	return false;
+}
+
+void nfs41_wake_slot_table(struct nfs4_slot_table *tbl)
+{
+	for (;;) {
+		if (!nfs41_try_wake_next_slot_table_entry(tbl))
+			break;
+	}
+}
+
+#if defined(CONFIG_NFS_V4_1)
+
+static void nfs41_set_max_slotid_locked(struct nfs4_slot_table *tbl,
+		u32 target_highest_slotid)
+{
+	u32 max_slotid;
+
+	max_slotid = min(NFS4_MAX_SLOT_TABLE - 1, target_highest_slotid);
+	if (max_slotid > tbl->server_highest_slotid)
+		max_slotid = tbl->server_highest_slotid;
+	if (max_slotid > tbl->target_highest_slotid)
+		max_slotid = tbl->target_highest_slotid;
+	tbl->max_slotid = max_slotid;
+	nfs41_wake_slot_table(tbl);
+}
+
+/* Update the client's idea of target_highest_slotid */
+static void nfs41_set_target_slotid_locked(struct nfs4_slot_table *tbl,
+		u32 target_highest_slotid)
+{
+	if (tbl->target_highest_slotid == target_highest_slotid)
+		return;
+	tbl->target_highest_slotid = target_highest_slotid;
+	tbl->generation++;
+}
+
+void nfs41_set_target_slotid(struct nfs4_slot_table *tbl,
+		u32 target_highest_slotid)
+{
+	spin_lock(&tbl->slot_tbl_lock);
+	nfs41_set_target_slotid_locked(tbl, target_highest_slotid);
+	tbl->d_target_highest_slotid = 0;
+	tbl->d2_target_highest_slotid = 0;
+	nfs41_set_max_slotid_locked(tbl, target_highest_slotid);
+	spin_unlock(&tbl->slot_tbl_lock);
+}
+
+static void nfs41_set_server_slotid_locked(struct nfs4_slot_table *tbl,
+		u32 highest_slotid)
+{
+	if (tbl->server_highest_slotid == highest_slotid)
+		return;
+	if (tbl->highest_used_slotid > highest_slotid)
+		return;
+	/* Deallocate slots */
+	nfs4_shrink_slot_table(tbl, highest_slotid + 1);
+	tbl->server_highest_slotid = highest_slotid;
+}
+
+static s32 nfs41_derivative_target_slotid(s32 s1, s32 s2)
+{
+	s1 -= s2;
+	if (s1 == 0)
+		return 0;
+	if (s1 < 0)
+		return (s1 - 1) >> 1;
+	return (s1 + 1) >> 1;
+}
+
+static int nfs41_sign_s32(s32 s1)
+{
+	if (s1 > 0)
+		return 1;
+	if (s1 < 0)
+		return -1;
+	return 0;
+}
+
+static bool nfs41_same_sign_or_zero_s32(s32 s1, s32 s2)
+{
+	if (!s1 || !s2)
+		return true;
+	return nfs41_sign_s32(s1) == nfs41_sign_s32(s2);
+}
+
+/* Try to eliminate outliers by checking for sharp changes in the
+ * derivatives and second derivatives
+ */
+static bool nfs41_is_outlier_target_slotid(struct nfs4_slot_table *tbl,
+		u32 new_target)
+{
+	s32 d_target, d2_target;
+	bool ret = true;
+
+	d_target = nfs41_derivative_target_slotid(new_target,
+			tbl->target_highest_slotid);
+	d2_target = nfs41_derivative_target_slotid(d_target,
+			tbl->d_target_highest_slotid);
+	/* Is first derivative same sign? */
+	if (nfs41_same_sign_or_zero_s32(d_target, tbl->d_target_highest_slotid))
+		ret = false;
+	/* Is second derivative same sign? */
+	if (nfs41_same_sign_or_zero_s32(d2_target, tbl->d2_target_highest_slotid))
+		ret = false;
+	tbl->d_target_highest_slotid = d_target;
+	tbl->d2_target_highest_slotid = d2_target;
+	return ret;
+}
+
+void nfs41_update_target_slotid(struct nfs4_slot_table *tbl,
+		struct nfs4_slot *slot,
+		struct nfs4_sequence_res *res)
+{
+	spin_lock(&tbl->slot_tbl_lock);
+	if (!nfs41_is_outlier_target_slotid(tbl, res->sr_target_highest_slotid))
+		nfs41_set_target_slotid_locked(tbl, res->sr_target_highest_slotid);
+	if (tbl->generation == slot->generation)
+		nfs41_set_server_slotid_locked(tbl, res->sr_highest_slotid);
+	nfs41_set_max_slotid_locked(tbl, res->sr_target_highest_slotid);
+	spin_unlock(&tbl->slot_tbl_lock);
+}
+
+static void nfs4_release_session_slot_tables(struct nfs4_session *session)
+{
+	nfs4_release_slot_table(&session->fc_slot_table);
+	nfs4_release_slot_table(&session->bc_slot_table);
+}
+
+/*
+ * Initialize or reset the forechannel and backchannel tables
+ */
+int nfs4_setup_session_slot_tables(struct nfs4_session *ses)
+{
+	struct nfs4_slot_table *tbl;
+	int status;
+
+	dprintk("--> %s\n", __func__);
+	/* Fore channel */
+	tbl = &ses->fc_slot_table;
+	tbl->session = ses;
+	status = nfs4_realloc_slot_table(tbl, ses->fc_attrs.max_reqs, 1);
+	if (status || !(ses->flags & SESSION4_BACK_CHAN)) /* -ENOMEM */
+		return status;
+	/* Back channel */
+	tbl = &ses->bc_slot_table;
+	tbl->session = ses;
+	status = nfs4_realloc_slot_table(tbl, ses->bc_attrs.max_reqs, 0);
+	if (status && tbl->slots == NULL)
+		/* Fore and back channel share a connection so get
+		 * both slot tables or neither */
+		nfs4_release_session_slot_tables(ses);
+	return status;
+}
+
+struct nfs4_session *nfs4_alloc_session(struct nfs_client *clp)
+{
+	struct nfs4_session *session;
+
+	session = kzalloc(sizeof(struct nfs4_session), GFP_NOFS);
+	if (!session)
+		return NULL;
+
+	nfs4_init_slot_table(&session->fc_slot_table, "ForeChannel Slot table");
+	nfs4_init_slot_table(&session->bc_slot_table, "BackChannel Slot table");
+	session->session_state = 1<<NFS4_SESSION_INITING;
+
+	session->clp = clp;
+	return session;
+}
+
+static void nfs4_destroy_session_slot_tables(struct nfs4_session *session)
+{
+	nfs4_shutdown_slot_table(&session->fc_slot_table);
+	nfs4_shutdown_slot_table(&session->bc_slot_table);
+}
+
+void nfs4_destroy_session(struct nfs4_session *session)
+{
+	struct rpc_xprt *xprt;
+	const struct cred *cred;
+
+	cred = nfs4_get_clid_cred(session->clp);
+	nfs4_proc_destroy_session(session, cred);
+	put_cred(cred);
+
+	rcu_read_lock();
+	xprt = rcu_dereference(session->clp->cl_rpcclient->cl_xprt);
+	rcu_read_unlock();
+	dprintk("%s Destroy backchannel for xprt %p\n",
+		__func__, xprt);
+	xprt_destroy_backchannel(xprt, NFS41_BC_MIN_CALLBACKS);
+	nfs4_destroy_session_slot_tables(session);
+	kfree(session);
+}
+
+/*
+ * With sessions, the client is not marked ready until after a
+ * successful EXCHANGE_ID and CREATE_SESSION.
+ *
+ * Map errors cl_cons_state errors to EPROTONOSUPPORT to indicate
+ * other versions of NFS can be tried.
+ */
+static int nfs41_check_session_ready(struct nfs_client *clp)
+{
+	int ret;
+	
+	if (clp->cl_cons_state == NFS_CS_SESSION_INITING) {
+		ret = nfs4_client_recover_expired_lease(clp);
+		if (ret)
+			return ret;
+	}
+	if (clp->cl_cons_state < NFS_CS_READY)
+		return -EPROTONOSUPPORT;
+	smp_rmb();
+	return 0;
+}
+
+int nfs4_init_session(struct nfs_client *clp)
+{
+	if (!nfs4_has_session(clp))
+		return 0;
+
+	clear_bit(NFS4_SESSION_INITING, &clp->cl_session->session_state);
+	return nfs41_check_session_ready(clp);
+}
+
+int nfs4_init_ds_session(struct nfs_client *clp, unsigned long lease_time)
+{
+	struct nfs4_session *session = clp->cl_session;
+	int ret;
+
+	spin_lock(&clp->cl_lock);
+	if (test_and_clear_bit(NFS4_SESSION_INITING, &session->session_state)) {
+		/*
+		 * Do not set NFS_CS_CHECK_LEASE_TIME instead set the
+		 * DS lease to be equal to the MDS lease.
+		 */
+		clp->cl_lease_time = lease_time;
+		clp->cl_last_renewal = jiffies;
+	}
+	spin_unlock(&clp->cl_lock);
+
+	ret = nfs41_check_session_ready(clp);
+	if (ret)
+		return ret;
+	/* Test for the DS role */
+	if (!is_ds_client(clp))
+		return -ENODEV;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nfs4_init_ds_session);
+
+#endif	/* defined(CONFIG_NFS_V4_1) */
diff --git a/fs/nfs/nfs4session.h b/fs/nfs/nfs4session.h
new file mode 100644
index 000000000..b996ee23f
--- /dev/null
+++ b/fs/nfs/nfs4session.h
@@ -0,0 +1,184 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * fs/nfs/nfs4session.h
+ *
+ * Copyright (c) 2012 Trond Myklebust <Trond.Myklebust@netapp.com>
+ *
+ */
+#ifndef __LINUX_FS_NFS_NFS4SESSION_H
+#define __LINUX_FS_NFS_NFS4SESSION_H
+
+/* maximum number of slots to use */
+#define NFS4_DEF_SLOT_TABLE_SIZE (64U)
+#define NFS4_DEF_CB_SLOT_TABLE_SIZE (16U)
+#define NFS4_MAX_SLOT_TABLE (1024U)
+#define NFS4_NO_SLOT ((u32)-1)
+
+#if IS_ENABLED(CONFIG_NFS_V4)
+
+/* Sessions slot seqid */
+struct nfs4_slot {
+	struct nfs4_slot_table	*table;
+	struct nfs4_slot	*next;
+	unsigned long		generation;
+	u32			slot_nr;
+	u32		 	seq_nr;
+	u32		 	seq_nr_last_acked;
+	u32		 	seq_nr_highest_sent;
+	unsigned int		privileged : 1,
+				seq_done : 1;
+};
+
+/* Sessions */
+enum nfs4_slot_tbl_state {
+	NFS4_SLOT_TBL_DRAINING,
+};
+
+#define SLOT_TABLE_SZ DIV_ROUND_UP(NFS4_MAX_SLOT_TABLE, 8*sizeof(long))
+struct nfs4_slot_table {
+	struct nfs4_session *session;		/* Parent session */
+	struct nfs4_slot *slots;		/* seqid per slot */
+	unsigned long   used_slots[SLOT_TABLE_SZ]; /* used/unused bitmap */
+	spinlock_t	slot_tbl_lock;
+	struct rpc_wait_queue	slot_tbl_waitq;	/* allocators may wait here */
+	wait_queue_head_t	slot_waitq;	/* Completion wait on slot */
+	u32		max_slots;		/* # slots in table */
+	u32		max_slotid;		/* Max allowed slotid value */
+	u32		highest_used_slotid;	/* sent to server on each SEQ.
+						 * op for dynamic resizing */
+	u32		target_highest_slotid;	/* Server max_slot target */
+	u32		server_highest_slotid;	/* Server highest slotid */
+	s32		d_target_highest_slotid; /* Derivative */
+	s32		d2_target_highest_slotid; /* 2nd derivative */
+	unsigned long	generation;		/* Generation counter for
+						   target_highest_slotid */
+	struct completion complete;
+	unsigned long	slot_tbl_state;
+};
+
+/*
+ * Session related parameters
+ */
+struct nfs4_session {
+	struct nfs4_sessionid		sess_id;
+	u32				flags;
+	unsigned long			session_state;
+	u32				hash_alg;
+	u32				ssv_len;
+
+	/* The fore and back channel */
+	struct nfs4_channel_attrs	fc_attrs;
+	struct nfs4_slot_table		fc_slot_table;
+	struct nfs4_channel_attrs	bc_attrs;
+	struct nfs4_slot_table		bc_slot_table;
+	struct nfs_client		*clp;
+};
+
+enum nfs4_session_state {
+	NFS4_SESSION_INITING,
+	NFS4_SESSION_ESTABLISHED,
+};
+
+extern int nfs4_setup_slot_table(struct nfs4_slot_table *tbl,
+		unsigned int max_reqs, const char *queue);
+extern void nfs4_shutdown_slot_table(struct nfs4_slot_table *tbl);
+extern struct nfs4_slot *nfs4_alloc_slot(struct nfs4_slot_table *tbl);
+extern struct nfs4_slot *nfs4_lookup_slot(struct nfs4_slot_table *tbl, u32 slotid);
+extern int nfs4_slot_wait_on_seqid(struct nfs4_slot_table *tbl,
+		u32 slotid, u32 seq_nr,
+		unsigned long timeout);
+extern bool nfs4_try_to_lock_slot(struct nfs4_slot_table *tbl, struct nfs4_slot *slot);
+extern void nfs4_free_slot(struct nfs4_slot_table *tbl, struct nfs4_slot *slot);
+extern void nfs4_slot_tbl_drain_complete(struct nfs4_slot_table *tbl);
+bool nfs41_wake_and_assign_slot(struct nfs4_slot_table *tbl,
+		struct nfs4_slot *slot);
+void nfs41_wake_slot_table(struct nfs4_slot_table *tbl);
+
+static inline bool nfs4_slot_tbl_draining(struct nfs4_slot_table *tbl)
+{
+	return !!test_bit(NFS4_SLOT_TBL_DRAINING, &tbl->slot_tbl_state);
+}
+
+static inline bool nfs4_test_locked_slot(const struct nfs4_slot_table *tbl,
+		u32 slotid)
+{
+	return !!test_bit(slotid, tbl->used_slots);
+}
+
+static inline struct nfs4_session *nfs4_get_session(const struct nfs_client *clp)
+{
+	return clp->cl_session;
+}
+
+#if defined(CONFIG_NFS_V4_1)
+extern void nfs41_set_target_slotid(struct nfs4_slot_table *tbl,
+		u32 target_highest_slotid);
+extern void nfs41_update_target_slotid(struct nfs4_slot_table *tbl,
+		struct nfs4_slot *slot,
+		struct nfs4_sequence_res *res);
+
+extern int nfs4_setup_session_slot_tables(struct nfs4_session *ses);
+
+extern struct nfs4_session *nfs4_alloc_session(struct nfs_client *clp);
+extern void nfs4_destroy_session(struct nfs4_session *session);
+extern int nfs4_init_session(struct nfs_client *clp);
+extern int nfs4_init_ds_session(struct nfs_client *, unsigned long);
+
+/*
+ * Determine if sessions are in use.
+ */
+static inline int nfs4_has_session(const struct nfs_client *clp)
+{
+	if (clp->cl_session)
+		return 1;
+	return 0;
+}
+
+static inline int nfs4_has_persistent_session(const struct nfs_client *clp)
+{
+	if (nfs4_has_session(clp))
+		return (clp->cl_session->flags & SESSION4_PERSIST);
+	return 0;
+}
+
+static inline void nfs4_copy_sessionid(struct nfs4_sessionid *dst,
+		const struct nfs4_sessionid *src)
+{
+	memcpy(dst->data, src->data, NFS4_MAX_SESSIONID_LEN);
+}
+
+#ifdef CONFIG_CRC32
+/*
+ * nfs_session_id_hash - calculate the crc32 hash for the session id
+ * @session - pointer to session
+ */
+#define nfs_session_id_hash(sess_id) \
+	(~crc32_le(0xFFFFFFFF, &(sess_id)->data[0], sizeof((sess_id)->data)))
+#else
+#define nfs_session_id_hash(session) (0)
+#endif
+#else /* defined(CONFIG_NFS_V4_1) */
+
+static inline int nfs4_init_session(struct nfs_client *clp)
+{
+	return 0;
+}
+
+/*
+ * Determine if sessions are in use.
+ */
+static inline int nfs4_has_session(const struct nfs_client *clp)
+{
+	return 0;
+}
+
+static inline int nfs4_has_persistent_session(const struct nfs_client *clp)
+{
+	return 0;
+}
+
+#define nfs_session_id_hash(session) (0)
+
+#endif /* defined(CONFIG_NFS_V4_1) */
+#endif /* IS_ENABLED(CONFIG_NFS_V4) */
+#endif /* __LINUX_FS_NFS_NFS4SESSION_H */
diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c
new file mode 100644
index 000000000..afb617a4a
--- /dev/null
+++ b/fs/nfs/nfs4state.c
@@ -0,0 +1,2768 @@
+/*
+ *  fs/nfs/nfs4state.c
+ *
+ *  Client-side XDR for NFSv4.
+ *
+ *  Copyright (c) 2002 The Regents of the University of Michigan.
+ *  All rights reserved.
+ *
+ *  Kendrick Smith <kmsmith@umich.edu>
+ *
+ *  Redistribution and use in source and binary forms, with or without
+ *  modification, are permitted provided that the following conditions
+ *  are met:
+ *
+ *  1. Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *  2. Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *  3. Neither the name of the University nor the names of its
+ *     contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+ *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * Implementation of the NFSv4 state model.  For the time being,
+ * this is minimal, but will be made much more complex in a
+ * subsequent patch.
+ */
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/fs.h>
+#include <linux/nfs_fs.h>
+#include <linux/kthread.h>
+#include <linux/module.h>
+#include <linux/random.h>
+#include <linux/ratelimit.h>
+#include <linux/workqueue.h>
+#include <linux/bitops.h>
+#include <linux/jiffies.h>
+#include <linux/sched/mm.h>
+
+#include <linux/sunrpc/clnt.h>
+
+#include "nfs4_fs.h"
+#include "callback.h"
+#include "delegation.h"
+#include "internal.h"
+#include "nfs4idmap.h"
+#include "nfs4session.h"
+#include "pnfs.h"
+#include "netns.h"
+#include "nfs4trace.h"
+
+#define NFSDBG_FACILITY		NFSDBG_STATE
+
+#define OPENOWNER_POOL_SIZE	8
+
+static void nfs4_state_start_reclaim_reboot(struct nfs_client *clp);
+
+const nfs4_stateid zero_stateid = {
+	{ .data = { 0 } },
+	.type = NFS4_SPECIAL_STATEID_TYPE,
+};
+const nfs4_stateid invalid_stateid = {
+	{
+		/* Funky initialiser keeps older gcc versions happy */
+		.data = { 0xff, 0xff, 0xff, 0xff, 0 },
+	},
+	.type = NFS4_INVALID_STATEID_TYPE,
+};
+
+const nfs4_stateid current_stateid = {
+	{
+		/* Funky initialiser keeps older gcc versions happy */
+		.data = { 0x0, 0x0, 0x0, 0x1, 0 },
+	},
+	.type = NFS4_SPECIAL_STATEID_TYPE,
+};
+
+static DEFINE_MUTEX(nfs_clid_init_mutex);
+
+static int nfs4_setup_state_renewal(struct nfs_client *clp)
+{
+	int status;
+	struct nfs_fsinfo fsinfo;
+
+	if (!test_bit(NFS_CS_CHECK_LEASE_TIME, &clp->cl_res_state)) {
+		nfs4_schedule_state_renewal(clp);
+		return 0;
+	}
+
+	status = nfs4_proc_get_lease_time(clp, &fsinfo);
+	if (status == 0) {
+		nfs4_set_lease_period(clp, fsinfo.lease_time * HZ);
+		nfs4_schedule_state_renewal(clp);
+	}
+
+	return status;
+}
+
+int nfs4_init_clientid(struct nfs_client *clp, const struct cred *cred)
+{
+	struct nfs4_setclientid_res clid = {
+		.clientid = clp->cl_clientid,
+		.confirm = clp->cl_confirm,
+	};
+	unsigned short port;
+	int status;
+	struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
+
+	if (test_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state))
+		goto do_confirm;
+	port = nn->nfs_callback_tcpport;
+	if (clp->cl_addr.ss_family == AF_INET6)
+		port = nn->nfs_callback_tcpport6;
+
+	status = nfs4_proc_setclientid(clp, NFS4_CALLBACK, port, cred, &clid);
+	if (status != 0)
+		goto out;
+	clp->cl_clientid = clid.clientid;
+	clp->cl_confirm = clid.confirm;
+	set_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
+do_confirm:
+	status = nfs4_proc_setclientid_confirm(clp, &clid, cred);
+	if (status != 0)
+		goto out;
+	clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
+	nfs4_setup_state_renewal(clp);
+out:
+	return status;
+}
+
+/**
+ * nfs40_discover_server_trunking - Detect server IP address trunking (mv0)
+ *
+ * @clp: nfs_client under test
+ * @result: OUT: found nfs_client, or clp
+ * @cred: credential to use for trunking test
+ *
+ * Returns zero, a negative errno, or a negative NFS4ERR status.
+ * If zero is returned, an nfs_client pointer is planted in
+ * "result".
+ *
+ * Note: The returned client may not yet be marked ready.
+ */
+int nfs40_discover_server_trunking(struct nfs_client *clp,
+				   struct nfs_client **result,
+				   const struct cred *cred)
+{
+	struct nfs4_setclientid_res clid = {
+		.clientid = clp->cl_clientid,
+		.confirm = clp->cl_confirm,
+	};
+	struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
+	unsigned short port;
+	int status;
+
+	port = nn->nfs_callback_tcpport;
+	if (clp->cl_addr.ss_family == AF_INET6)
+		port = nn->nfs_callback_tcpport6;
+
+	status = nfs4_proc_setclientid(clp, NFS4_CALLBACK, port, cred, &clid);
+	if (status != 0)
+		goto out;
+	clp->cl_clientid = clid.clientid;
+	clp->cl_confirm = clid.confirm;
+
+	status = nfs40_walk_client_list(clp, result, cred);
+	if (status == 0) {
+		/* Sustain the lease, even if it's empty.  If the clientid4
+		 * goes stale it's of no use for trunking discovery. */
+		nfs4_schedule_state_renewal(*result);
+
+		/* If the client state need to recover, do it. */
+		if (clp->cl_state)
+			nfs4_schedule_state_manager(clp);
+	}
+out:
+	return status;
+}
+
+const struct cred *nfs4_get_machine_cred(struct nfs_client *clp)
+{
+	return get_cred(rpc_machine_cred());
+}
+
+static void nfs4_root_machine_cred(struct nfs_client *clp)
+{
+
+	/* Force root creds instead of machine */
+	clp->cl_principal = NULL;
+	clp->cl_rpcclient->cl_principal = NULL;
+}
+
+static const struct cred *
+nfs4_get_renew_cred_server_locked(struct nfs_server *server)
+{
+	const struct cred *cred = NULL;
+	struct nfs4_state_owner *sp;
+	struct rb_node *pos;
+
+	for (pos = rb_first(&server->state_owners);
+	     pos != NULL;
+	     pos = rb_next(pos)) {
+		sp = rb_entry(pos, struct nfs4_state_owner, so_server_node);
+		if (list_empty(&sp->so_states))
+			continue;
+		cred = get_cred(sp->so_cred);
+		break;
+	}
+	return cred;
+}
+
+/**
+ * nfs4_get_renew_cred - Acquire credential for a renew operation
+ * @clp: client state handle
+ *
+ * Returns an rpc_cred with reference count bumped, or NULL.
+ * Caller must hold clp->cl_lock.
+ */
+const struct cred *nfs4_get_renew_cred(struct nfs_client *clp)
+{
+	const struct cred *cred = NULL;
+	struct nfs_server *server;
+
+	/* Use machine credentials if available */
+	cred = nfs4_get_machine_cred(clp);
+	if (cred != NULL)
+		goto out;
+
+	spin_lock(&clp->cl_lock);
+	rcu_read_lock();
+	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
+		cred = nfs4_get_renew_cred_server_locked(server);
+		if (cred != NULL)
+			break;
+	}
+	rcu_read_unlock();
+	spin_unlock(&clp->cl_lock);
+
+out:
+	return cred;
+}
+
+static void nfs4_end_drain_slot_table(struct nfs4_slot_table *tbl)
+{
+	if (test_and_clear_bit(NFS4_SLOT_TBL_DRAINING, &tbl->slot_tbl_state)) {
+		spin_lock(&tbl->slot_tbl_lock);
+		nfs41_wake_slot_table(tbl);
+		spin_unlock(&tbl->slot_tbl_lock);
+	}
+}
+
+static void nfs4_end_drain_session(struct nfs_client *clp)
+{
+	struct nfs4_session *ses = clp->cl_session;
+
+	if (clp->cl_slot_tbl) {
+		nfs4_end_drain_slot_table(clp->cl_slot_tbl);
+		return;
+	}
+
+	if (ses != NULL) {
+		nfs4_end_drain_slot_table(&ses->bc_slot_table);
+		nfs4_end_drain_slot_table(&ses->fc_slot_table);
+	}
+}
+
+static int nfs4_drain_slot_tbl(struct nfs4_slot_table *tbl)
+{
+	set_bit(NFS4_SLOT_TBL_DRAINING, &tbl->slot_tbl_state);
+	spin_lock(&tbl->slot_tbl_lock);
+	if (tbl->highest_used_slotid != NFS4_NO_SLOT) {
+		reinit_completion(&tbl->complete);
+		spin_unlock(&tbl->slot_tbl_lock);
+		return wait_for_completion_interruptible(&tbl->complete);
+	}
+	spin_unlock(&tbl->slot_tbl_lock);
+	return 0;
+}
+
+static int nfs4_begin_drain_session(struct nfs_client *clp)
+{
+	struct nfs4_session *ses = clp->cl_session;
+	int ret;
+
+	if (clp->cl_slot_tbl)
+		return nfs4_drain_slot_tbl(clp->cl_slot_tbl);
+
+	/* back channel */
+	ret = nfs4_drain_slot_tbl(&ses->bc_slot_table);
+	if (ret)
+		return ret;
+	/* fore channel */
+	return nfs4_drain_slot_tbl(&ses->fc_slot_table);
+}
+
+#if defined(CONFIG_NFS_V4_1)
+
+static void nfs41_finish_session_reset(struct nfs_client *clp)
+{
+	clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
+	clear_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
+	/* create_session negotiated new slot table */
+	clear_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
+	nfs4_setup_state_renewal(clp);
+}
+
+int nfs41_init_clientid(struct nfs_client *clp, const struct cred *cred)
+{
+	int status;
+
+	if (test_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state))
+		goto do_confirm;
+	status = nfs4_proc_exchange_id(clp, cred);
+	if (status != 0)
+		goto out;
+	set_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
+do_confirm:
+	status = nfs4_proc_create_session(clp, cred);
+	if (status != 0)
+		goto out;
+	if (!(clp->cl_exchange_flags & EXCHGID4_FLAG_CONFIRMED_R))
+		nfs4_state_start_reclaim_reboot(clp);
+	nfs41_finish_session_reset(clp);
+	nfs_mark_client_ready(clp, NFS_CS_READY);
+out:
+	return status;
+}
+
+/**
+ * nfs41_discover_server_trunking - Detect server IP address trunking (mv1)
+ *
+ * @clp: nfs_client under test
+ * @result: OUT: found nfs_client, or clp
+ * @cred: credential to use for trunking test
+ *
+ * Returns NFS4_OK, a negative errno, or a negative NFS4ERR status.
+ * If NFS4_OK is returned, an nfs_client pointer is planted in
+ * "result".
+ *
+ * Note: The returned client may not yet be marked ready.
+ */
+int nfs41_discover_server_trunking(struct nfs_client *clp,
+				   struct nfs_client **result,
+				   const struct cred *cred)
+{
+	int status;
+
+	status = nfs4_proc_exchange_id(clp, cred);
+	if (status != NFS4_OK)
+		return status;
+
+	status = nfs41_walk_client_list(clp, result, cred);
+	if (status < 0)
+		return status;
+	if (clp != *result)
+		return 0;
+
+	/*
+	 * Purge state if the client id was established in a prior
+	 * instance and the client id could not have arrived on the
+	 * server via Transparent State Migration.
+	 */
+	if (clp->cl_exchange_flags & EXCHGID4_FLAG_CONFIRMED_R) {
+		if (!test_bit(NFS_CS_TSM_POSSIBLE, &clp->cl_flags))
+			set_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state);
+		else
+			set_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
+	}
+	nfs4_schedule_state_manager(clp);
+	status = nfs_wait_client_init_complete(clp);
+	if (status < 0)
+		nfs_put_client(clp);
+	return status;
+}
+
+#endif /* CONFIG_NFS_V4_1 */
+
+/**
+ * nfs4_get_clid_cred - Acquire credential for a setclientid operation
+ * @clp: client state handle
+ *
+ * Returns a cred with reference count bumped, or NULL.
+ */
+const struct cred *nfs4_get_clid_cred(struct nfs_client *clp)
+{
+	const struct cred *cred;
+
+	cred = nfs4_get_machine_cred(clp);
+	return cred;
+}
+
+static struct nfs4_state_owner *
+nfs4_find_state_owner_locked(struct nfs_server *server, const struct cred *cred)
+{
+	struct rb_node **p = &server->state_owners.rb_node,
+		       *parent = NULL;
+	struct nfs4_state_owner *sp;
+	int cmp;
+
+	while (*p != NULL) {
+		parent = *p;
+		sp = rb_entry(parent, struct nfs4_state_owner, so_server_node);
+		cmp = cred_fscmp(cred, sp->so_cred);
+
+		if (cmp < 0)
+			p = &parent->rb_left;
+		else if (cmp > 0)
+			p = &parent->rb_right;
+		else {
+			if (!list_empty(&sp->so_lru))
+				list_del_init(&sp->so_lru);
+			atomic_inc(&sp->so_count);
+			return sp;
+		}
+	}
+	return NULL;
+}
+
+static struct nfs4_state_owner *
+nfs4_insert_state_owner_locked(struct nfs4_state_owner *new)
+{
+	struct nfs_server *server = new->so_server;
+	struct rb_node **p = &server->state_owners.rb_node,
+		       *parent = NULL;
+	struct nfs4_state_owner *sp;
+	int cmp;
+
+	while (*p != NULL) {
+		parent = *p;
+		sp = rb_entry(parent, struct nfs4_state_owner, so_server_node);
+		cmp = cred_fscmp(new->so_cred, sp->so_cred);
+
+		if (cmp < 0)
+			p = &parent->rb_left;
+		else if (cmp > 0)
+			p = &parent->rb_right;
+		else {
+			if (!list_empty(&sp->so_lru))
+				list_del_init(&sp->so_lru);
+			atomic_inc(&sp->so_count);
+			return sp;
+		}
+	}
+	rb_link_node(&new->so_server_node, parent, p);
+	rb_insert_color(&new->so_server_node, &server->state_owners);
+	return new;
+}
+
+static void
+nfs4_remove_state_owner_locked(struct nfs4_state_owner *sp)
+{
+	struct nfs_server *server = sp->so_server;
+
+	if (!RB_EMPTY_NODE(&sp->so_server_node))
+		rb_erase(&sp->so_server_node, &server->state_owners);
+}
+
+static void
+nfs4_init_seqid_counter(struct nfs_seqid_counter *sc)
+{
+	sc->create_time = ktime_get();
+	sc->flags = 0;
+	sc->counter = 0;
+	spin_lock_init(&sc->lock);
+	INIT_LIST_HEAD(&sc->list);
+	rpc_init_wait_queue(&sc->wait, "Seqid_waitqueue");
+}
+
+static void
+nfs4_destroy_seqid_counter(struct nfs_seqid_counter *sc)
+{
+	rpc_destroy_wait_queue(&sc->wait);
+}
+
+/*
+ * nfs4_alloc_state_owner(): this is called on the OPEN or CREATE path to
+ * create a new state_owner.
+ *
+ */
+static struct nfs4_state_owner *
+nfs4_alloc_state_owner(struct nfs_server *server,
+		const struct cred *cred,
+		gfp_t gfp_flags)
+{
+	struct nfs4_state_owner *sp;
+
+	sp = kzalloc(sizeof(*sp), gfp_flags);
+	if (!sp)
+		return NULL;
+	sp->so_seqid.owner_id = ida_simple_get(&server->openowner_id, 0, 0,
+						gfp_flags);
+	if (sp->so_seqid.owner_id < 0) {
+		kfree(sp);
+		return NULL;
+	}
+	sp->so_server = server;
+	sp->so_cred = get_cred(cred);
+	spin_lock_init(&sp->so_lock);
+	INIT_LIST_HEAD(&sp->so_states);
+	nfs4_init_seqid_counter(&sp->so_seqid);
+	atomic_set(&sp->so_count, 1);
+	INIT_LIST_HEAD(&sp->so_lru);
+	seqcount_spinlock_init(&sp->so_reclaim_seqcount, &sp->so_lock);
+	mutex_init(&sp->so_delegreturn_mutex);
+	return sp;
+}
+
+static void
+nfs4_reset_state_owner(struct nfs4_state_owner *sp)
+{
+	/* This state_owner is no longer usable, but must
+	 * remain in place so that state recovery can find it
+	 * and the opens associated with it.
+	 * It may also be used for new 'open' request to
+	 * return a delegation to the server.
+	 * So update the 'create_time' so that it looks like
+	 * a new state_owner.  This will cause the server to
+	 * request an OPEN_CONFIRM to start a new sequence.
+	 */
+	sp->so_seqid.create_time = ktime_get();
+}
+
+static void nfs4_free_state_owner(struct nfs4_state_owner *sp)
+{
+	nfs4_destroy_seqid_counter(&sp->so_seqid);
+	put_cred(sp->so_cred);
+	ida_simple_remove(&sp->so_server->openowner_id, sp->so_seqid.owner_id);
+	kfree(sp);
+}
+
+static void nfs4_gc_state_owners(struct nfs_server *server)
+{
+	struct nfs_client *clp = server->nfs_client;
+	struct nfs4_state_owner *sp, *tmp;
+	unsigned long time_min, time_max;
+	LIST_HEAD(doomed);
+
+	spin_lock(&clp->cl_lock);
+	time_max = jiffies;
+	time_min = (long)time_max - (long)clp->cl_lease_time;
+	list_for_each_entry_safe(sp, tmp, &server->state_owners_lru, so_lru) {
+		/* NB: LRU is sorted so that oldest is at the head */
+		if (time_in_range(sp->so_expires, time_min, time_max))
+			break;
+		list_move(&sp->so_lru, &doomed);
+		nfs4_remove_state_owner_locked(sp);
+	}
+	spin_unlock(&clp->cl_lock);
+
+	list_for_each_entry_safe(sp, tmp, &doomed, so_lru) {
+		list_del(&sp->so_lru);
+		nfs4_free_state_owner(sp);
+	}
+}
+
+/**
+ * nfs4_get_state_owner - Look up a state owner given a credential
+ * @server: nfs_server to search
+ * @cred: RPC credential to match
+ * @gfp_flags: allocation mode
+ *
+ * Returns a pointer to an instantiated nfs4_state_owner struct, or NULL.
+ */
+struct nfs4_state_owner *nfs4_get_state_owner(struct nfs_server *server,
+					      const struct cred *cred,
+					      gfp_t gfp_flags)
+{
+	struct nfs_client *clp = server->nfs_client;
+	struct nfs4_state_owner *sp, *new;
+
+	spin_lock(&clp->cl_lock);
+	sp = nfs4_find_state_owner_locked(server, cred);
+	spin_unlock(&clp->cl_lock);
+	if (sp != NULL)
+		goto out;
+	new = nfs4_alloc_state_owner(server, cred, gfp_flags);
+	if (new == NULL)
+		goto out;
+	spin_lock(&clp->cl_lock);
+	sp = nfs4_insert_state_owner_locked(new);
+	spin_unlock(&clp->cl_lock);
+	if (sp != new)
+		nfs4_free_state_owner(new);
+out:
+	nfs4_gc_state_owners(server);
+	return sp;
+}
+
+/**
+ * nfs4_put_state_owner - Release a nfs4_state_owner
+ * @sp: state owner data to release
+ *
+ * Note that we keep released state owners on an LRU
+ * list.
+ * This caches valid state owners so that they can be
+ * reused, to avoid the OPEN_CONFIRM on minor version 0.
+ * It also pins the uniquifier of dropped state owners for
+ * a while, to ensure that those state owner names are
+ * never reused.
+ */
+void nfs4_put_state_owner(struct nfs4_state_owner *sp)
+{
+	struct nfs_server *server = sp->so_server;
+	struct nfs_client *clp = server->nfs_client;
+
+	if (!atomic_dec_and_lock(&sp->so_count, &clp->cl_lock))
+		return;
+
+	sp->so_expires = jiffies;
+	list_add_tail(&sp->so_lru, &server->state_owners_lru);
+	spin_unlock(&clp->cl_lock);
+}
+
+/**
+ * nfs4_purge_state_owners - Release all cached state owners
+ * @server: nfs_server with cached state owners to release
+ * @head: resulting list of state owners
+ *
+ * Called at umount time.  Remaining state owners will be on
+ * the LRU with ref count of zero.
+ * Note that the state owners are not freed, but are added
+ * to the list @head, which can later be used as an argument
+ * to nfs4_free_state_owners.
+ */
+void nfs4_purge_state_owners(struct nfs_server *server, struct list_head *head)
+{
+	struct nfs_client *clp = server->nfs_client;
+	struct nfs4_state_owner *sp, *tmp;
+
+	spin_lock(&clp->cl_lock);
+	list_for_each_entry_safe(sp, tmp, &server->state_owners_lru, so_lru) {
+		list_move(&sp->so_lru, head);
+		nfs4_remove_state_owner_locked(sp);
+	}
+	spin_unlock(&clp->cl_lock);
+}
+
+/**
+ * nfs4_purge_state_owners - Release all cached state owners
+ * @head: resulting list of state owners
+ *
+ * Frees a list of state owners that was generated by
+ * nfs4_purge_state_owners
+ */
+void nfs4_free_state_owners(struct list_head *head)
+{
+	struct nfs4_state_owner *sp, *tmp;
+
+	list_for_each_entry_safe(sp, tmp, head, so_lru) {
+		list_del(&sp->so_lru);
+		nfs4_free_state_owner(sp);
+	}
+}
+
+static struct nfs4_state *
+nfs4_alloc_open_state(void)
+{
+	struct nfs4_state *state;
+
+	state = kzalloc(sizeof(*state), GFP_NOFS);
+	if (!state)
+		return NULL;
+	refcount_set(&state->count, 1);
+	INIT_LIST_HEAD(&state->lock_states);
+	spin_lock_init(&state->state_lock);
+	seqlock_init(&state->seqlock);
+	init_waitqueue_head(&state->waitq);
+	return state;
+}
+
+void
+nfs4_state_set_mode_locked(struct nfs4_state *state, fmode_t fmode)
+{
+	if (state->state == fmode)
+		return;
+	/* NB! List reordering - see the reclaim code for why.  */
+	if ((fmode & FMODE_WRITE) != (state->state & FMODE_WRITE)) {
+		if (fmode & FMODE_WRITE)
+			list_move(&state->open_states, &state->owner->so_states);
+		else
+			list_move_tail(&state->open_states, &state->owner->so_states);
+	}
+	state->state = fmode;
+}
+
+static struct nfs4_state *
+__nfs4_find_state_byowner(struct inode *inode, struct nfs4_state_owner *owner)
+{
+	struct nfs_inode *nfsi = NFS_I(inode);
+	struct nfs4_state *state;
+
+	list_for_each_entry_rcu(state, &nfsi->open_states, inode_states) {
+		if (state->owner != owner)
+			continue;
+		if (!nfs4_valid_open_stateid(state))
+			continue;
+		if (refcount_inc_not_zero(&state->count))
+			return state;
+	}
+	return NULL;
+}
+
+static void
+nfs4_free_open_state(struct nfs4_state *state)
+{
+	kfree_rcu(state, rcu_head);
+}
+
+struct nfs4_state *
+nfs4_get_open_state(struct inode *inode, struct nfs4_state_owner *owner)
+{
+	struct nfs4_state *state, *new;
+	struct nfs_inode *nfsi = NFS_I(inode);
+
+	rcu_read_lock();
+	state = __nfs4_find_state_byowner(inode, owner);
+	rcu_read_unlock();
+	if (state)
+		goto out;
+	new = nfs4_alloc_open_state();
+	spin_lock(&owner->so_lock);
+	spin_lock(&inode->i_lock);
+	state = __nfs4_find_state_byowner(inode, owner);
+	if (state == NULL && new != NULL) {
+		state = new;
+		state->owner = owner;
+		atomic_inc(&owner->so_count);
+		ihold(inode);
+		state->inode = inode;
+		list_add_rcu(&state->inode_states, &nfsi->open_states);
+		spin_unlock(&inode->i_lock);
+		/* Note: The reclaim code dictates that we add stateless
+		 * and read-only stateids to the end of the list */
+		list_add_tail(&state->open_states, &owner->so_states);
+		spin_unlock(&owner->so_lock);
+	} else {
+		spin_unlock(&inode->i_lock);
+		spin_unlock(&owner->so_lock);
+		if (new)
+			nfs4_free_open_state(new);
+	}
+out:
+	return state;
+}
+
+void nfs4_put_open_state(struct nfs4_state *state)
+{
+	struct inode *inode = state->inode;
+	struct nfs4_state_owner *owner = state->owner;
+
+	if (!refcount_dec_and_lock(&state->count, &owner->so_lock))
+		return;
+	spin_lock(&inode->i_lock);
+	list_del_rcu(&state->inode_states);
+	list_del(&state->open_states);
+	spin_unlock(&inode->i_lock);
+	spin_unlock(&owner->so_lock);
+	nfs4_inode_return_delegation_on_close(inode);
+	iput(inode);
+	nfs4_free_open_state(state);
+	nfs4_put_state_owner(owner);
+}
+
+/*
+ * Close the current file.
+ */
+static void __nfs4_close(struct nfs4_state *state,
+		fmode_t fmode, gfp_t gfp_mask, int wait)
+{
+	struct nfs4_state_owner *owner = state->owner;
+	int call_close = 0;
+	fmode_t newstate;
+
+	atomic_inc(&owner->so_count);
+	/* Protect against nfs4_find_state() */
+	spin_lock(&owner->so_lock);
+	switch (fmode & (FMODE_READ | FMODE_WRITE)) {
+		case FMODE_READ:
+			state->n_rdonly--;
+			break;
+		case FMODE_WRITE:
+			state->n_wronly--;
+			break;
+		case FMODE_READ|FMODE_WRITE:
+			state->n_rdwr--;
+	}
+	newstate = FMODE_READ|FMODE_WRITE;
+	if (state->n_rdwr == 0) {
+		if (state->n_rdonly == 0) {
+			newstate &= ~FMODE_READ;
+			call_close |= test_bit(NFS_O_RDONLY_STATE, &state->flags);
+			call_close |= test_bit(NFS_O_RDWR_STATE, &state->flags);
+		}
+		if (state->n_wronly == 0) {
+			newstate &= ~FMODE_WRITE;
+			call_close |= test_bit(NFS_O_WRONLY_STATE, &state->flags);
+			call_close |= test_bit(NFS_O_RDWR_STATE, &state->flags);
+		}
+		if (newstate == 0)
+			clear_bit(NFS_DELEGATED_STATE, &state->flags);
+	}
+	nfs4_state_set_mode_locked(state, newstate);
+	spin_unlock(&owner->so_lock);
+
+	if (!call_close) {
+		nfs4_put_open_state(state);
+		nfs4_put_state_owner(owner);
+	} else
+		nfs4_do_close(state, gfp_mask, wait);
+}
+
+void nfs4_close_state(struct nfs4_state *state, fmode_t fmode)
+{
+	__nfs4_close(state, fmode, GFP_NOFS, 0);
+}
+
+void nfs4_close_sync(struct nfs4_state *state, fmode_t fmode)
+{
+	__nfs4_close(state, fmode, GFP_KERNEL, 1);
+}
+
+/*
+ * Search the state->lock_states for an existing lock_owner
+ * that is compatible with either of the given owners.
+ * If the second is non-zero, then the first refers to a Posix-lock
+ * owner (current->files) and the second refers to a flock/OFD
+ * owner (struct file*).  In that case, prefer a match for the first
+ * owner.
+ * If both sorts of locks are held on the one file we cannot know
+ * which stateid was intended to be used, so a "correct" choice cannot
+ * be made.  Failing that, a "consistent" choice is preferable.  The
+ * consistent choice we make is to prefer the first owner, that of a
+ * Posix lock.
+ */
+static struct nfs4_lock_state *
+__nfs4_find_lock_state(struct nfs4_state *state,
+		       fl_owner_t fl_owner, fl_owner_t fl_owner2)
+{
+	struct nfs4_lock_state *pos, *ret = NULL;
+	list_for_each_entry(pos, &state->lock_states, ls_locks) {
+		if (pos->ls_owner == fl_owner) {
+			ret = pos;
+			break;
+		}
+		if (pos->ls_owner == fl_owner2)
+			ret = pos;
+	}
+	if (ret)
+		refcount_inc(&ret->ls_count);
+	return ret;
+}
+
+/*
+ * Return a compatible lock_state. If no initialized lock_state structure
+ * exists, return an uninitialized one.
+ *
+ */
+static struct nfs4_lock_state *nfs4_alloc_lock_state(struct nfs4_state *state, fl_owner_t fl_owner)
+{
+	struct nfs4_lock_state *lsp;
+	struct nfs_server *server = state->owner->so_server;
+
+	lsp = kzalloc(sizeof(*lsp), GFP_NOFS);
+	if (lsp == NULL)
+		return NULL;
+	nfs4_init_seqid_counter(&lsp->ls_seqid);
+	refcount_set(&lsp->ls_count, 1);
+	lsp->ls_state = state;
+	lsp->ls_owner = fl_owner;
+	lsp->ls_seqid.owner_id = ida_simple_get(&server->lockowner_id, 0, 0, GFP_NOFS);
+	if (lsp->ls_seqid.owner_id < 0)
+		goto out_free;
+	INIT_LIST_HEAD(&lsp->ls_locks);
+	return lsp;
+out_free:
+	kfree(lsp);
+	return NULL;
+}
+
+void nfs4_free_lock_state(struct nfs_server *server, struct nfs4_lock_state *lsp)
+{
+	ida_simple_remove(&server->lockowner_id, lsp->ls_seqid.owner_id);
+	nfs4_destroy_seqid_counter(&lsp->ls_seqid);
+	kfree(lsp);
+}
+
+/*
+ * Return a compatible lock_state. If no initialized lock_state structure
+ * exists, return an uninitialized one.
+ *
+ */
+static struct nfs4_lock_state *nfs4_get_lock_state(struct nfs4_state *state, fl_owner_t owner)
+{
+	struct nfs4_lock_state *lsp, *new = NULL;
+	
+	for(;;) {
+		spin_lock(&state->state_lock);
+		lsp = __nfs4_find_lock_state(state, owner, NULL);
+		if (lsp != NULL)
+			break;
+		if (new != NULL) {
+			list_add(&new->ls_locks, &state->lock_states);
+			set_bit(LK_STATE_IN_USE, &state->flags);
+			lsp = new;
+			new = NULL;
+			break;
+		}
+		spin_unlock(&state->state_lock);
+		new = nfs4_alloc_lock_state(state, owner);
+		if (new == NULL)
+			return NULL;
+	}
+	spin_unlock(&state->state_lock);
+	if (new != NULL)
+		nfs4_free_lock_state(state->owner->so_server, new);
+	return lsp;
+}
+
+/*
+ * Release reference to lock_state, and free it if we see that
+ * it is no longer in use
+ */
+void nfs4_put_lock_state(struct nfs4_lock_state *lsp)
+{
+	struct nfs_server *server;
+	struct nfs4_state *state;
+
+	if (lsp == NULL)
+		return;
+	state = lsp->ls_state;
+	if (!refcount_dec_and_lock(&lsp->ls_count, &state->state_lock))
+		return;
+	list_del(&lsp->ls_locks);
+	if (list_empty(&state->lock_states))
+		clear_bit(LK_STATE_IN_USE, &state->flags);
+	spin_unlock(&state->state_lock);
+	server = state->owner->so_server;
+	if (test_bit(NFS_LOCK_INITIALIZED, &lsp->ls_flags)) {
+		struct nfs_client *clp = server->nfs_client;
+
+		clp->cl_mvops->free_lock_state(server, lsp);
+	} else
+		nfs4_free_lock_state(server, lsp);
+}
+
+static void nfs4_fl_copy_lock(struct file_lock *dst, struct file_lock *src)
+{
+	struct nfs4_lock_state *lsp = src->fl_u.nfs4_fl.owner;
+
+	dst->fl_u.nfs4_fl.owner = lsp;
+	refcount_inc(&lsp->ls_count);
+}
+
+static void nfs4_fl_release_lock(struct file_lock *fl)
+{
+	nfs4_put_lock_state(fl->fl_u.nfs4_fl.owner);
+}
+
+static const struct file_lock_operations nfs4_fl_lock_ops = {
+	.fl_copy_lock = nfs4_fl_copy_lock,
+	.fl_release_private = nfs4_fl_release_lock,
+};
+
+int nfs4_set_lock_state(struct nfs4_state *state, struct file_lock *fl)
+{
+	struct nfs4_lock_state *lsp;
+
+	if (fl->fl_ops != NULL)
+		return 0;
+	lsp = nfs4_get_lock_state(state, fl->fl_owner);
+	if (lsp == NULL)
+		return -ENOMEM;
+	fl->fl_u.nfs4_fl.owner = lsp;
+	fl->fl_ops = &nfs4_fl_lock_ops;
+	return 0;
+}
+
+static int nfs4_copy_lock_stateid(nfs4_stateid *dst,
+		struct nfs4_state *state,
+		const struct nfs_lock_context *l_ctx)
+{
+	struct nfs4_lock_state *lsp;
+	fl_owner_t fl_owner, fl_flock_owner;
+	int ret = -ENOENT;
+
+	if (l_ctx == NULL)
+		goto out;
+
+	if (test_bit(LK_STATE_IN_USE, &state->flags) == 0)
+		goto out;
+
+	fl_owner = l_ctx->lockowner;
+	fl_flock_owner = l_ctx->open_context->flock_owner;
+
+	spin_lock(&state->state_lock);
+	lsp = __nfs4_find_lock_state(state, fl_owner, fl_flock_owner);
+	if (lsp && test_bit(NFS_LOCK_LOST, &lsp->ls_flags))
+		ret = -EIO;
+	else if (lsp != NULL && test_bit(NFS_LOCK_INITIALIZED, &lsp->ls_flags) != 0) {
+		nfs4_stateid_copy(dst, &lsp->ls_stateid);
+		ret = 0;
+	}
+	spin_unlock(&state->state_lock);
+	nfs4_put_lock_state(lsp);
+out:
+	return ret;
+}
+
+bool nfs4_copy_open_stateid(nfs4_stateid *dst, struct nfs4_state *state)
+{
+	bool ret;
+	const nfs4_stateid *src;
+	int seq;
+
+	do {
+		ret = false;
+		src = &zero_stateid;
+		seq = read_seqbegin(&state->seqlock);
+		if (test_bit(NFS_OPEN_STATE, &state->flags)) {
+			src = &state->open_stateid;
+			ret = true;
+		}
+		nfs4_stateid_copy(dst, src);
+	} while (read_seqretry(&state->seqlock, seq));
+	return ret;
+}
+
+/*
+ * Byte-range lock aware utility to initialize the stateid of read/write
+ * requests.
+ */
+int nfs4_select_rw_stateid(struct nfs4_state *state,
+		fmode_t fmode, const struct nfs_lock_context *l_ctx,
+		nfs4_stateid *dst, const struct cred **cred)
+{
+	int ret;
+
+	if (!nfs4_valid_open_stateid(state))
+		return -EIO;
+	if (cred != NULL)
+		*cred = NULL;
+	ret = nfs4_copy_lock_stateid(dst, state, l_ctx);
+	if (ret == -EIO)
+		/* A lost lock - don't even consider delegations */
+		goto out;
+	/* returns true if delegation stateid found and copied */
+	if (nfs4_copy_delegation_stateid(state->inode, fmode, dst, cred)) {
+		ret = 0;
+		goto out;
+	}
+	if (ret != -ENOENT)
+		/* nfs4_copy_delegation_stateid() didn't over-write
+		 * dst, so it still has the lock stateid which we now
+		 * choose to use.
+		 */
+		goto out;
+	ret = nfs4_copy_open_stateid(dst, state) ? 0 : -EAGAIN;
+out:
+	if (nfs_server_capable(state->inode, NFS_CAP_STATEID_NFSV41))
+		dst->seqid = 0;
+	return ret;
+}
+
+struct nfs_seqid *nfs_alloc_seqid(struct nfs_seqid_counter *counter, gfp_t gfp_mask)
+{
+	struct nfs_seqid *new;
+
+	new = kmalloc(sizeof(*new), gfp_mask);
+	if (new == NULL)
+		return ERR_PTR(-ENOMEM);
+	new->sequence = counter;
+	INIT_LIST_HEAD(&new->list);
+	new->task = NULL;
+	return new;
+}
+
+void nfs_release_seqid(struct nfs_seqid *seqid)
+{
+	struct nfs_seqid_counter *sequence;
+
+	if (seqid == NULL || list_empty(&seqid->list))
+		return;
+	sequence = seqid->sequence;
+	spin_lock(&sequence->lock);
+	list_del_init(&seqid->list);
+	if (!list_empty(&sequence->list)) {
+		struct nfs_seqid *next;
+
+		next = list_first_entry(&sequence->list,
+				struct nfs_seqid, list);
+		rpc_wake_up_queued_task(&sequence->wait, next->task);
+	}
+	spin_unlock(&sequence->lock);
+}
+
+void nfs_free_seqid(struct nfs_seqid *seqid)
+{
+	nfs_release_seqid(seqid);
+	kfree(seqid);
+}
+
+/*
+ * Increment the seqid if the OPEN/OPEN_DOWNGRADE/CLOSE succeeded, or
+ * failed with a seqid incrementing error -
+ * see comments nfs4.h:seqid_mutating_error()
+ */
+static void nfs_increment_seqid(int status, struct nfs_seqid *seqid)
+{
+	switch (status) {
+		case 0:
+			break;
+		case -NFS4ERR_BAD_SEQID:
+			if (seqid->sequence->flags & NFS_SEQID_CONFIRMED)
+				return;
+			pr_warn_ratelimited("NFS: v4 server returned a bad"
+					" sequence-id error on an"
+					" unconfirmed sequence %p!\n",
+					seqid->sequence);
+		case -NFS4ERR_STALE_CLIENTID:
+		case -NFS4ERR_STALE_STATEID:
+		case -NFS4ERR_BAD_STATEID:
+		case -NFS4ERR_BADXDR:
+		case -NFS4ERR_RESOURCE:
+		case -NFS4ERR_NOFILEHANDLE:
+		case -NFS4ERR_MOVED:
+			/* Non-seqid mutating errors */
+			return;
+	}
+	/*
+	 * Note: no locking needed as we are guaranteed to be first
+	 * on the sequence list
+	 */
+	seqid->sequence->counter++;
+}
+
+void nfs_increment_open_seqid(int status, struct nfs_seqid *seqid)
+{
+	struct nfs4_state_owner *sp;
+
+	if (seqid == NULL)
+		return;
+
+	sp = container_of(seqid->sequence, struct nfs4_state_owner, so_seqid);
+	if (status == -NFS4ERR_BAD_SEQID)
+		nfs4_reset_state_owner(sp);
+	if (!nfs4_has_session(sp->so_server->nfs_client))
+		nfs_increment_seqid(status, seqid);
+}
+
+/*
+ * Increment the seqid if the LOCK/LOCKU succeeded, or
+ * failed with a seqid incrementing error -
+ * see comments nfs4.h:seqid_mutating_error()
+ */
+void nfs_increment_lock_seqid(int status, struct nfs_seqid *seqid)
+{
+	if (seqid != NULL)
+		nfs_increment_seqid(status, seqid);
+}
+
+int nfs_wait_on_sequence(struct nfs_seqid *seqid, struct rpc_task *task)
+{
+	struct nfs_seqid_counter *sequence;
+	int status = 0;
+
+	if (seqid == NULL)
+		goto out;
+	sequence = seqid->sequence;
+	spin_lock(&sequence->lock);
+	seqid->task = task;
+	if (list_empty(&seqid->list))
+		list_add_tail(&seqid->list, &sequence->list);
+	if (list_first_entry(&sequence->list, struct nfs_seqid, list) == seqid)
+		goto unlock;
+	rpc_sleep_on(&sequence->wait, task, NULL);
+	status = -EAGAIN;
+unlock:
+	spin_unlock(&sequence->lock);
+out:
+	return status;
+}
+
+static int nfs4_run_state_manager(void *);
+
+static void nfs4_clear_state_manager_bit(struct nfs_client *clp)
+{
+	smp_mb__before_atomic();
+	clear_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state);
+	smp_mb__after_atomic();
+	wake_up_bit(&clp->cl_state, NFS4CLNT_MANAGER_RUNNING);
+	rpc_wake_up(&clp->cl_rpcwaitq);
+}
+
+/*
+ * Schedule the nfs_client asynchronous state management routine
+ */
+void nfs4_schedule_state_manager(struct nfs_client *clp)
+{
+	struct task_struct *task;
+	char buf[INET6_ADDRSTRLEN + sizeof("-manager") + 1];
+	struct rpc_clnt *clnt = clp->cl_rpcclient;
+	bool swapon = false;
+
+	set_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state);
+
+	if (atomic_read(&clnt->cl_swapper)) {
+		swapon = !test_and_set_bit(NFS4CLNT_MANAGER_AVAILABLE,
+					   &clp->cl_state);
+		if (!swapon) {
+			wake_up_var(&clp->cl_state);
+			return;
+		}
+	}
+
+	if (test_and_set_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state) != 0)
+		return;
+
+	__module_get(THIS_MODULE);
+	refcount_inc(&clp->cl_count);
+
+	/* The rcu_read_lock() is not strictly necessary, as the state
+	 * manager is the only thread that ever changes the rpc_xprt
+	 * after it's initialized.  At this point, we're single threaded. */
+	rcu_read_lock();
+	snprintf(buf, sizeof(buf), "%s-manager",
+			rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_ADDR));
+	rcu_read_unlock();
+	task = kthread_run(nfs4_run_state_manager, clp, "%s", buf);
+	if (IS_ERR(task)) {
+		printk(KERN_ERR "%s: kthread_run: %ld\n",
+			__func__, PTR_ERR(task));
+		if (!nfs_client_init_is_complete(clp))
+			nfs_mark_client_ready(clp, PTR_ERR(task));
+		if (swapon)
+			clear_bit(NFS4CLNT_MANAGER_AVAILABLE, &clp->cl_state);
+		nfs4_clear_state_manager_bit(clp);
+		nfs_put_client(clp);
+		module_put(THIS_MODULE);
+	}
+}
+
+/*
+ * Schedule a lease recovery attempt
+ */
+void nfs4_schedule_lease_recovery(struct nfs_client *clp)
+{
+	if (!clp)
+		return;
+	if (!test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
+		set_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
+	dprintk("%s: scheduling lease recovery for server %s\n", __func__,
+			clp->cl_hostname);
+	nfs4_schedule_state_manager(clp);
+}
+EXPORT_SYMBOL_GPL(nfs4_schedule_lease_recovery);
+
+/**
+ * nfs4_schedule_migration_recovery - trigger migration recovery
+ *
+ * @server: FSID that is migrating
+ *
+ * Returns zero if recovery has started, otherwise a negative NFS4ERR
+ * value is returned.
+ */
+int nfs4_schedule_migration_recovery(const struct nfs_server *server)
+{
+	struct nfs_client *clp = server->nfs_client;
+
+	if (server->fh_expire_type != NFS4_FH_PERSISTENT) {
+		pr_err("NFS: volatile file handles not supported (server %s)\n",
+				clp->cl_hostname);
+		return -NFS4ERR_IO;
+	}
+
+	if (test_bit(NFS_MIG_FAILED, &server->mig_status))
+		return -NFS4ERR_IO;
+
+	dprintk("%s: scheduling migration recovery for (%llx:%llx) on %s\n",
+			__func__,
+			(unsigned long long)server->fsid.major,
+			(unsigned long long)server->fsid.minor,
+			clp->cl_hostname);
+
+	set_bit(NFS_MIG_IN_TRANSITION,
+			&((struct nfs_server *)server)->mig_status);
+	set_bit(NFS4CLNT_MOVED, &clp->cl_state);
+
+	nfs4_schedule_state_manager(clp);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nfs4_schedule_migration_recovery);
+
+/**
+ * nfs4_schedule_lease_moved_recovery - start lease-moved recovery
+ *
+ * @clp: server to check for moved leases
+ *
+ */
+void nfs4_schedule_lease_moved_recovery(struct nfs_client *clp)
+{
+	dprintk("%s: scheduling lease-moved recovery for client ID %llx on %s\n",
+		__func__, clp->cl_clientid, clp->cl_hostname);
+
+	set_bit(NFS4CLNT_LEASE_MOVED, &clp->cl_state);
+	nfs4_schedule_state_manager(clp);
+}
+EXPORT_SYMBOL_GPL(nfs4_schedule_lease_moved_recovery);
+
+int nfs4_wait_clnt_recover(struct nfs_client *clp)
+{
+	int res;
+
+	might_sleep();
+
+	refcount_inc(&clp->cl_count);
+	res = wait_on_bit_action(&clp->cl_state, NFS4CLNT_MANAGER_RUNNING,
+				 nfs_wait_bit_killable, TASK_KILLABLE);
+	if (res)
+		goto out;
+	if (clp->cl_cons_state < 0)
+		res = clp->cl_cons_state;
+out:
+	nfs_put_client(clp);
+	return res;
+}
+
+int nfs4_client_recover_expired_lease(struct nfs_client *clp)
+{
+	unsigned int loop;
+	int ret;
+
+	for (loop = NFS4_MAX_LOOP_ON_RECOVER; loop != 0; loop--) {
+		ret = nfs4_wait_clnt_recover(clp);
+		if (ret != 0)
+			break;
+		if (!test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) &&
+		    !test_bit(NFS4CLNT_CHECK_LEASE,&clp->cl_state))
+			break;
+		nfs4_schedule_state_manager(clp);
+		ret = -EIO;
+	}
+	return ret;
+}
+
+/*
+ * nfs40_handle_cb_pathdown - return all delegations after NFS4ERR_CB_PATH_DOWN
+ * @clp: client to process
+ *
+ * Set the NFS4CLNT_LEASE_EXPIRED state in order to force a
+ * resend of the SETCLIENTID and hence re-establish the
+ * callback channel. Then return all existing delegations.
+ */
+static void nfs40_handle_cb_pathdown(struct nfs_client *clp)
+{
+	set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
+	nfs_expire_all_delegations(clp);
+	dprintk("%s: handling CB_PATHDOWN recovery for server %s\n", __func__,
+			clp->cl_hostname);
+}
+
+void nfs4_schedule_path_down_recovery(struct nfs_client *clp)
+{
+	nfs40_handle_cb_pathdown(clp);
+	nfs4_schedule_state_manager(clp);
+}
+
+static int nfs4_state_mark_reclaim_reboot(struct nfs_client *clp, struct nfs4_state *state)
+{
+
+	if (!nfs4_valid_open_stateid(state))
+		return 0;
+	set_bit(NFS_STATE_RECLAIM_REBOOT, &state->flags);
+	/* Don't recover state that expired before the reboot */
+	if (test_bit(NFS_STATE_RECLAIM_NOGRACE, &state->flags)) {
+		clear_bit(NFS_STATE_RECLAIM_REBOOT, &state->flags);
+		return 0;
+	}
+	set_bit(NFS_OWNER_RECLAIM_REBOOT, &state->owner->so_flags);
+	set_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state);
+	return 1;
+}
+
+int nfs4_state_mark_reclaim_nograce(struct nfs_client *clp, struct nfs4_state *state)
+{
+	if (!nfs4_valid_open_stateid(state))
+		return 0;
+	set_bit(NFS_STATE_RECLAIM_NOGRACE, &state->flags);
+	clear_bit(NFS_STATE_RECLAIM_REBOOT, &state->flags);
+	set_bit(NFS_OWNER_RECLAIM_NOGRACE, &state->owner->so_flags);
+	set_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state);
+	return 1;
+}
+
+int nfs4_schedule_stateid_recovery(const struct nfs_server *server, struct nfs4_state *state)
+{
+	struct nfs_client *clp = server->nfs_client;
+
+	if (!nfs4_state_mark_reclaim_nograce(clp, state))
+		return -EBADF;
+	nfs_inode_find_delegation_state_and_recover(state->inode,
+			&state->stateid);
+	dprintk("%s: scheduling stateid recovery for server %s\n", __func__,
+			clp->cl_hostname);
+	nfs4_schedule_state_manager(clp);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nfs4_schedule_stateid_recovery);
+
+static struct nfs4_lock_state *
+nfs_state_find_lock_state_by_stateid(struct nfs4_state *state,
+		const nfs4_stateid *stateid)
+{
+	struct nfs4_lock_state *pos;
+
+	list_for_each_entry(pos, &state->lock_states, ls_locks) {
+		if (!test_bit(NFS_LOCK_INITIALIZED, &pos->ls_flags))
+			continue;
+		if (nfs4_stateid_match_or_older(&pos->ls_stateid, stateid))
+			return pos;
+	}
+	return NULL;
+}
+
+static bool nfs_state_lock_state_matches_stateid(struct nfs4_state *state,
+		const nfs4_stateid *stateid)
+{
+	bool found = false;
+
+	if (test_bit(LK_STATE_IN_USE, &state->flags)) {
+		spin_lock(&state->state_lock);
+		if (nfs_state_find_lock_state_by_stateid(state, stateid))
+			found = true;
+		spin_unlock(&state->state_lock);
+	}
+	return found;
+}
+
+void nfs_inode_find_state_and_recover(struct inode *inode,
+		const nfs4_stateid *stateid)
+{
+	struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
+	struct nfs_inode *nfsi = NFS_I(inode);
+	struct nfs_open_context *ctx;
+	struct nfs4_state *state;
+	bool found = false;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(ctx, &nfsi->open_files, list) {
+		state = ctx->state;
+		if (state == NULL)
+			continue;
+		if (nfs4_stateid_match_or_older(&state->stateid, stateid) &&
+		    nfs4_state_mark_reclaim_nograce(clp, state)) {
+			found = true;
+			continue;
+		}
+		if (test_bit(NFS_OPEN_STATE, &state->flags) &&
+		    nfs4_stateid_match_or_older(&state->open_stateid, stateid) &&
+		    nfs4_state_mark_reclaim_nograce(clp, state)) {
+			found = true;
+			continue;
+		}
+		if (nfs_state_lock_state_matches_stateid(state, stateid) &&
+		    nfs4_state_mark_reclaim_nograce(clp, state))
+			found = true;
+	}
+	rcu_read_unlock();
+
+	nfs_inode_find_delegation_state_and_recover(inode, stateid);
+	if (found)
+		nfs4_schedule_state_manager(clp);
+}
+
+static void nfs4_state_mark_open_context_bad(struct nfs4_state *state, int err)
+{
+	struct inode *inode = state->inode;
+	struct nfs_inode *nfsi = NFS_I(inode);
+	struct nfs_open_context *ctx;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(ctx, &nfsi->open_files, list) {
+		if (ctx->state != state)
+			continue;
+		set_bit(NFS_CONTEXT_BAD, &ctx->flags);
+		pr_warn("NFSv4: state recovery failed for open file %pd2, "
+				"error = %d\n", ctx->dentry, err);
+	}
+	rcu_read_unlock();
+}
+
+static void nfs4_state_mark_recovery_failed(struct nfs4_state *state, int error)
+{
+	set_bit(NFS_STATE_RECOVERY_FAILED, &state->flags);
+	nfs4_state_mark_open_context_bad(state, error);
+}
+
+
+static int nfs4_reclaim_locks(struct nfs4_state *state, const struct nfs4_state_recovery_ops *ops)
+{
+	struct inode *inode = state->inode;
+	struct nfs_inode *nfsi = NFS_I(inode);
+	struct file_lock *fl;
+	struct nfs4_lock_state *lsp;
+	int status = 0;
+	struct file_lock_context *flctx = inode->i_flctx;
+	struct list_head *list;
+
+	if (flctx == NULL)
+		return 0;
+
+	list = &flctx->flc_posix;
+
+	/* Guard against delegation returns and new lock/unlock calls */
+	down_write(&nfsi->rwsem);
+	spin_lock(&flctx->flc_lock);
+restart:
+	list_for_each_entry(fl, list, fl_list) {
+		if (nfs_file_open_context(fl->fl_file)->state != state)
+			continue;
+		spin_unlock(&flctx->flc_lock);
+		status = ops->recover_lock(state, fl);
+		switch (status) {
+		case 0:
+			break;
+		case -ETIMEDOUT:
+		case -ESTALE:
+		case -NFS4ERR_ADMIN_REVOKED:
+		case -NFS4ERR_STALE_STATEID:
+		case -NFS4ERR_BAD_STATEID:
+		case -NFS4ERR_EXPIRED:
+		case -NFS4ERR_NO_GRACE:
+		case -NFS4ERR_STALE_CLIENTID:
+		case -NFS4ERR_BADSESSION:
+		case -NFS4ERR_BADSLOT:
+		case -NFS4ERR_BAD_HIGH_SLOT:
+		case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
+			goto out;
+		default:
+			pr_err("NFS: %s: unhandled error %d\n",
+					__func__, status);
+			fallthrough;
+		case -ENOMEM:
+		case -NFS4ERR_DENIED:
+		case -NFS4ERR_RECLAIM_BAD:
+		case -NFS4ERR_RECLAIM_CONFLICT:
+			lsp = fl->fl_u.nfs4_fl.owner;
+			if (lsp)
+				set_bit(NFS_LOCK_LOST, &lsp->ls_flags);
+			status = 0;
+		}
+		spin_lock(&flctx->flc_lock);
+	}
+	if (list == &flctx->flc_posix) {
+		list = &flctx->flc_flock;
+		goto restart;
+	}
+	spin_unlock(&flctx->flc_lock);
+out:
+	up_write(&nfsi->rwsem);
+	return status;
+}
+
+#ifdef CONFIG_NFS_V4_2
+static void nfs42_complete_copies(struct nfs4_state_owner *sp, struct nfs4_state *state)
+{
+	struct nfs4_copy_state *copy;
+
+	if (!test_bit(NFS_CLNT_DST_SSC_COPY_STATE, &state->flags) &&
+		!test_bit(NFS_CLNT_SRC_SSC_COPY_STATE, &state->flags))
+		return;
+
+	spin_lock(&sp->so_server->nfs_client->cl_lock);
+	list_for_each_entry(copy, &sp->so_server->ss_copies, copies) {
+		if ((test_bit(NFS_CLNT_DST_SSC_COPY_STATE, &state->flags) &&
+				!nfs4_stateid_match_other(&state->stateid,
+				&copy->parent_dst_state->stateid)))
+				continue;
+		copy->flags = 1;
+		if (test_and_clear_bit(NFS_CLNT_DST_SSC_COPY_STATE,
+				&state->flags)) {
+			clear_bit(NFS_CLNT_SRC_SSC_COPY_STATE, &state->flags);
+			complete(&copy->completion);
+		}
+	}
+	list_for_each_entry(copy, &sp->so_server->ss_copies, src_copies) {
+		if ((test_bit(NFS_CLNT_SRC_SSC_COPY_STATE, &state->flags) &&
+				!nfs4_stateid_match_other(&state->stateid,
+				&copy->parent_src_state->stateid)))
+				continue;
+		copy->flags = 1;
+		if (test_and_clear_bit(NFS_CLNT_DST_SSC_COPY_STATE,
+				&state->flags))
+			complete(&copy->completion);
+	}
+	spin_unlock(&sp->so_server->nfs_client->cl_lock);
+}
+#else /* !CONFIG_NFS_V4_2 */
+static inline void nfs42_complete_copies(struct nfs4_state_owner *sp,
+					 struct nfs4_state *state)
+{
+}
+#endif /* CONFIG_NFS_V4_2 */
+
+static int __nfs4_reclaim_open_state(struct nfs4_state_owner *sp, struct nfs4_state *state,
+				     const struct nfs4_state_recovery_ops *ops)
+{
+	struct nfs4_lock_state *lock;
+	int status;
+
+	status = ops->recover_open(sp, state);
+	if (status < 0)
+		return status;
+
+	status = nfs4_reclaim_locks(state, ops);
+	if (status < 0)
+		return status;
+
+	if (!test_bit(NFS_DELEGATED_STATE, &state->flags)) {
+		spin_lock(&state->state_lock);
+		list_for_each_entry(lock, &state->lock_states, ls_locks) {
+			trace_nfs4_state_lock_reclaim(state, lock);
+			if (!test_bit(NFS_LOCK_INITIALIZED, &lock->ls_flags))
+				pr_warn_ratelimited("NFS: %s: Lock reclaim failed!\n", __func__);
+		}
+		spin_unlock(&state->state_lock);
+	}
+
+	nfs42_complete_copies(sp, state);
+	clear_bit(NFS_STATE_RECLAIM_NOGRACE, &state->flags);
+	return status;
+}
+
+static int nfs4_reclaim_open_state(struct nfs4_state_owner *sp, const struct nfs4_state_recovery_ops *ops)
+{
+	struct nfs4_state *state;
+	unsigned int loop = 0;
+	int status = 0;
+#ifdef CONFIG_NFS_V4_2
+	bool found_ssc_copy_state = false;
+#endif /* CONFIG_NFS_V4_2 */
+
+	/* Note: we rely on the sp->so_states list being ordered 
+	 * so that we always reclaim open(O_RDWR) and/or open(O_WRITE)
+	 * states first.
+	 * This is needed to ensure that the server won't give us any
+	 * read delegations that we have to return if, say, we are
+	 * recovering after a network partition or a reboot from a
+	 * server that doesn't support a grace period.
+	 */
+	spin_lock(&sp->so_lock);
+	raw_write_seqcount_begin(&sp->so_reclaim_seqcount);
+restart:
+	list_for_each_entry(state, &sp->so_states, open_states) {
+		if (!test_and_clear_bit(ops->state_flag_bit, &state->flags))
+			continue;
+		if (!nfs4_valid_open_stateid(state))
+			continue;
+		if (state->state == 0)
+			continue;
+#ifdef CONFIG_NFS_V4_2
+		if (test_bit(NFS_SRV_SSC_COPY_STATE, &state->flags)) {
+			nfs4_state_mark_recovery_failed(state, -EIO);
+			found_ssc_copy_state = true;
+			continue;
+		}
+#endif /* CONFIG_NFS_V4_2 */
+		refcount_inc(&state->count);
+		spin_unlock(&sp->so_lock);
+		status = __nfs4_reclaim_open_state(sp, state, ops);
+
+		switch (status) {
+		default:
+			if (status >= 0) {
+				loop = 0;
+				break;
+			}
+			printk(KERN_ERR "NFS: %s: unhandled error %d\n", __func__, status);
+			fallthrough;
+		case -ENOENT:
+		case -ENOMEM:
+		case -EACCES:
+		case -EROFS:
+		case -EIO:
+		case -ESTALE:
+			/* Open state on this file cannot be recovered */
+			nfs4_state_mark_recovery_failed(state, status);
+			break;
+		case -EAGAIN:
+			ssleep(1);
+			if (loop++ < 10) {
+				set_bit(ops->state_flag_bit, &state->flags);
+				break;
+			}
+			fallthrough;
+		case -NFS4ERR_ADMIN_REVOKED:
+		case -NFS4ERR_STALE_STATEID:
+		case -NFS4ERR_OLD_STATEID:
+		case -NFS4ERR_BAD_STATEID:
+		case -NFS4ERR_RECLAIM_BAD:
+		case -NFS4ERR_RECLAIM_CONFLICT:
+			nfs4_state_mark_reclaim_nograce(sp->so_server->nfs_client, state);
+			break;
+		case -NFS4ERR_EXPIRED:
+		case -NFS4ERR_NO_GRACE:
+			nfs4_state_mark_reclaim_nograce(sp->so_server->nfs_client, state);
+			fallthrough;
+		case -NFS4ERR_STALE_CLIENTID:
+		case -NFS4ERR_BADSESSION:
+		case -NFS4ERR_BADSLOT:
+		case -NFS4ERR_BAD_HIGH_SLOT:
+		case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
+		case -ETIMEDOUT:
+			goto out_err;
+		}
+		nfs4_put_open_state(state);
+		spin_lock(&sp->so_lock);
+		goto restart;
+	}
+	raw_write_seqcount_end(&sp->so_reclaim_seqcount);
+	spin_unlock(&sp->so_lock);
+#ifdef CONFIG_NFS_V4_2
+	if (found_ssc_copy_state)
+		return -EIO;
+#endif /* CONFIG_NFS_V4_2 */
+	return 0;
+out_err:
+	nfs4_put_open_state(state);
+	spin_lock(&sp->so_lock);
+	raw_write_seqcount_end(&sp->so_reclaim_seqcount);
+	spin_unlock(&sp->so_lock);
+	return status;
+}
+
+static void nfs4_clear_open_state(struct nfs4_state *state)
+{
+	struct nfs4_lock_state *lock;
+
+	clear_bit(NFS_DELEGATED_STATE, &state->flags);
+	clear_bit(NFS_O_RDONLY_STATE, &state->flags);
+	clear_bit(NFS_O_WRONLY_STATE, &state->flags);
+	clear_bit(NFS_O_RDWR_STATE, &state->flags);
+	spin_lock(&state->state_lock);
+	list_for_each_entry(lock, &state->lock_states, ls_locks) {
+		lock->ls_seqid.flags = 0;
+		clear_bit(NFS_LOCK_INITIALIZED, &lock->ls_flags);
+	}
+	spin_unlock(&state->state_lock);
+}
+
+static void nfs4_reset_seqids(struct nfs_server *server,
+	int (*mark_reclaim)(struct nfs_client *clp, struct nfs4_state *state))
+{
+	struct nfs_client *clp = server->nfs_client;
+	struct nfs4_state_owner *sp;
+	struct rb_node *pos;
+	struct nfs4_state *state;
+
+	spin_lock(&clp->cl_lock);
+	for (pos = rb_first(&server->state_owners);
+	     pos != NULL;
+	     pos = rb_next(pos)) {
+		sp = rb_entry(pos, struct nfs4_state_owner, so_server_node);
+		sp->so_seqid.flags = 0;
+		spin_lock(&sp->so_lock);
+		list_for_each_entry(state, &sp->so_states, open_states) {
+			if (mark_reclaim(clp, state))
+				nfs4_clear_open_state(state);
+		}
+		spin_unlock(&sp->so_lock);
+	}
+	spin_unlock(&clp->cl_lock);
+}
+
+static void nfs4_state_mark_reclaim_helper(struct nfs_client *clp,
+	int (*mark_reclaim)(struct nfs_client *clp, struct nfs4_state *state))
+{
+	struct nfs_server *server;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
+		nfs4_reset_seqids(server, mark_reclaim);
+	rcu_read_unlock();
+}
+
+static void nfs4_state_start_reclaim_reboot(struct nfs_client *clp)
+{
+	set_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state);
+	/* Mark all delegations for reclaim */
+	nfs_delegation_mark_reclaim(clp);
+	nfs4_state_mark_reclaim_helper(clp, nfs4_state_mark_reclaim_reboot);
+}
+
+static int nfs4_reclaim_complete(struct nfs_client *clp,
+				 const struct nfs4_state_recovery_ops *ops,
+				 const struct cred *cred)
+{
+	/* Notify the server we're done reclaiming our state */
+	if (ops->reclaim_complete)
+		return ops->reclaim_complete(clp, cred);
+	return 0;
+}
+
+static void nfs4_clear_reclaim_server(struct nfs_server *server)
+{
+	struct nfs_client *clp = server->nfs_client;
+	struct nfs4_state_owner *sp;
+	struct rb_node *pos;
+	struct nfs4_state *state;
+
+	spin_lock(&clp->cl_lock);
+	for (pos = rb_first(&server->state_owners);
+	     pos != NULL;
+	     pos = rb_next(pos)) {
+		sp = rb_entry(pos, struct nfs4_state_owner, so_server_node);
+		spin_lock(&sp->so_lock);
+		list_for_each_entry(state, &sp->so_states, open_states) {
+			if (!test_and_clear_bit(NFS_STATE_RECLAIM_REBOOT,
+						&state->flags))
+				continue;
+			nfs4_state_mark_reclaim_nograce(clp, state);
+		}
+		spin_unlock(&sp->so_lock);
+	}
+	spin_unlock(&clp->cl_lock);
+}
+
+static int nfs4_state_clear_reclaim_reboot(struct nfs_client *clp)
+{
+	struct nfs_server *server;
+
+	if (!test_and_clear_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state))
+		return 0;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
+		nfs4_clear_reclaim_server(server);
+	rcu_read_unlock();
+
+	nfs_delegation_reap_unclaimed(clp);
+	return 1;
+}
+
+static void nfs4_state_end_reclaim_reboot(struct nfs_client *clp)
+{
+	const struct nfs4_state_recovery_ops *ops;
+	const struct cred *cred;
+	int err;
+
+	if (!nfs4_state_clear_reclaim_reboot(clp))
+		return;
+	ops = clp->cl_mvops->reboot_recovery_ops;
+	cred = nfs4_get_clid_cred(clp);
+	err = nfs4_reclaim_complete(clp, ops, cred);
+	put_cred(cred);
+	if (err == -NFS4ERR_CONN_NOT_BOUND_TO_SESSION)
+		set_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state);
+}
+
+static void nfs4_state_start_reclaim_nograce(struct nfs_client *clp)
+{
+	nfs_mark_test_expired_all_delegations(clp);
+	nfs4_state_mark_reclaim_helper(clp, nfs4_state_mark_reclaim_nograce);
+}
+
+static int nfs4_recovery_handle_error(struct nfs_client *clp, int error)
+{
+	switch (error) {
+	case 0:
+		break;
+	case -NFS4ERR_CB_PATH_DOWN:
+		nfs40_handle_cb_pathdown(clp);
+		break;
+	case -NFS4ERR_NO_GRACE:
+		nfs4_state_end_reclaim_reboot(clp);
+		break;
+	case -NFS4ERR_STALE_CLIENTID:
+		set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
+		nfs4_state_start_reclaim_reboot(clp);
+		break;
+	case -NFS4ERR_EXPIRED:
+		set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
+		nfs4_state_start_reclaim_nograce(clp);
+		break;
+	case -NFS4ERR_BADSESSION:
+	case -NFS4ERR_BADSLOT:
+	case -NFS4ERR_BAD_HIGH_SLOT:
+	case -NFS4ERR_DEADSESSION:
+	case -NFS4ERR_SEQ_FALSE_RETRY:
+	case -NFS4ERR_SEQ_MISORDERED:
+		set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
+		/* Zero session reset errors */
+		break;
+	case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
+		set_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
+		break;
+	default:
+		dprintk("%s: failed to handle error %d for server %s\n",
+				__func__, error, clp->cl_hostname);
+		return error;
+	}
+	dprintk("%s: handled error %d for server %s\n", __func__, error,
+			clp->cl_hostname);
+	return 0;
+}
+
+static int nfs4_do_reclaim(struct nfs_client *clp, const struct nfs4_state_recovery_ops *ops)
+{
+	struct nfs4_state_owner *sp;
+	struct nfs_server *server;
+	struct rb_node *pos;
+	LIST_HEAD(freeme);
+	int status = 0;
+
+restart:
+	rcu_read_lock();
+	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
+		nfs4_purge_state_owners(server, &freeme);
+		spin_lock(&clp->cl_lock);
+		for (pos = rb_first(&server->state_owners);
+		     pos != NULL;
+		     pos = rb_next(pos)) {
+			sp = rb_entry(pos,
+				struct nfs4_state_owner, so_server_node);
+			if (!test_and_clear_bit(ops->owner_flag_bit,
+							&sp->so_flags))
+				continue;
+			if (!atomic_inc_not_zero(&sp->so_count))
+				continue;
+			spin_unlock(&clp->cl_lock);
+			rcu_read_unlock();
+
+			status = nfs4_reclaim_open_state(sp, ops);
+			if (status < 0) {
+				set_bit(ops->owner_flag_bit, &sp->so_flags);
+				nfs4_put_state_owner(sp);
+				status = nfs4_recovery_handle_error(clp, status);
+				return (status != 0) ? status : -EAGAIN;
+			}
+
+			nfs4_put_state_owner(sp);
+			goto restart;
+		}
+		spin_unlock(&clp->cl_lock);
+	}
+	rcu_read_unlock();
+	nfs4_free_state_owners(&freeme);
+	return 0;
+}
+
+static int nfs4_check_lease(struct nfs_client *clp)
+{
+	const struct cred *cred;
+	const struct nfs4_state_maintenance_ops *ops =
+		clp->cl_mvops->state_renewal_ops;
+	int status;
+
+	/* Is the client already known to have an expired lease? */
+	if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
+		return 0;
+	cred = ops->get_state_renewal_cred(clp);
+	if (cred == NULL) {
+		cred = nfs4_get_clid_cred(clp);
+		status = -ENOKEY;
+		if (cred == NULL)
+			goto out;
+	}
+	status = ops->renew_lease(clp, cred);
+	put_cred(cred);
+	if (status == -ETIMEDOUT) {
+		set_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
+		return 0;
+	}
+out:
+	return nfs4_recovery_handle_error(clp, status);
+}
+
+/* Set NFS4CLNT_LEASE_EXPIRED and reclaim reboot state for all v4.0 errors
+ * and for recoverable errors on EXCHANGE_ID for v4.1
+ */
+static int nfs4_handle_reclaim_lease_error(struct nfs_client *clp, int status)
+{
+	switch (status) {
+	case -NFS4ERR_SEQ_MISORDERED:
+		if (test_and_set_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state))
+			return -ESERVERFAULT;
+		/* Lease confirmation error: retry after purging the lease */
+		ssleep(1);
+		clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
+		break;
+	case -NFS4ERR_STALE_CLIENTID:
+		clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
+		nfs4_state_start_reclaim_reboot(clp);
+		break;
+	case -NFS4ERR_CLID_INUSE:
+		pr_err("NFS: Server %s reports our clientid is in use\n",
+			clp->cl_hostname);
+		nfs_mark_client_ready(clp, -EPERM);
+		clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
+		return -EPERM;
+	case -EACCES:
+	case -NFS4ERR_DELAY:
+	case -EAGAIN:
+		ssleep(1);
+		break;
+
+	case -NFS4ERR_MINOR_VERS_MISMATCH:
+		if (clp->cl_cons_state == NFS_CS_SESSION_INITING)
+			nfs_mark_client_ready(clp, -EPROTONOSUPPORT);
+		dprintk("%s: exit with error %d for server %s\n",
+				__func__, -EPROTONOSUPPORT, clp->cl_hostname);
+		return -EPROTONOSUPPORT;
+	case -NFS4ERR_NOT_SAME: /* FixMe: implement recovery
+				 * in nfs4_exchange_id */
+	default:
+		dprintk("%s: exit with error %d for server %s\n", __func__,
+				status, clp->cl_hostname);
+		return status;
+	}
+	set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
+	dprintk("%s: handled error %d for server %s\n", __func__, status,
+			clp->cl_hostname);
+	return 0;
+}
+
+static int nfs4_establish_lease(struct nfs_client *clp)
+{
+	const struct cred *cred;
+	const struct nfs4_state_recovery_ops *ops =
+		clp->cl_mvops->reboot_recovery_ops;
+	int status;
+
+	status = nfs4_begin_drain_session(clp);
+	if (status != 0)
+		return status;
+	cred = nfs4_get_clid_cred(clp);
+	if (cred == NULL)
+		return -ENOENT;
+	status = ops->establish_clid(clp, cred);
+	put_cred(cred);
+	if (status != 0)
+		return status;
+	pnfs_destroy_all_layouts(clp);
+	return 0;
+}
+
+/*
+ * Returns zero or a negative errno.  NFS4ERR values are converted
+ * to local errno values.
+ */
+static int nfs4_reclaim_lease(struct nfs_client *clp)
+{
+	int status;
+
+	status = nfs4_establish_lease(clp);
+	if (status < 0)
+		return nfs4_handle_reclaim_lease_error(clp, status);
+	if (test_and_clear_bit(NFS4CLNT_SERVER_SCOPE_MISMATCH, &clp->cl_state))
+		nfs4_state_start_reclaim_nograce(clp);
+	if (!test_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state))
+		set_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state);
+	clear_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
+	clear_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
+	return 0;
+}
+
+static int nfs4_purge_lease(struct nfs_client *clp)
+{
+	int status;
+
+	status = nfs4_establish_lease(clp);
+	if (status < 0)
+		return nfs4_handle_reclaim_lease_error(clp, status);
+	clear_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state);
+	set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
+	nfs4_state_start_reclaim_nograce(clp);
+	return 0;
+}
+
+/*
+ * Try remote migration of one FSID from a source server to a
+ * destination server.  The source server provides a list of
+ * potential destinations.
+ *
+ * Returns zero or a negative NFS4ERR status code.
+ */
+static int nfs4_try_migration(struct nfs_server *server, const struct cred *cred)
+{
+	struct nfs_client *clp = server->nfs_client;
+	struct nfs4_fs_locations *locations = NULL;
+	struct inode *inode;
+	struct page *page;
+	int status, result;
+
+	dprintk("--> %s: FSID %llx:%llx on \"%s\"\n", __func__,
+			(unsigned long long)server->fsid.major,
+			(unsigned long long)server->fsid.minor,
+			clp->cl_hostname);
+
+	result = 0;
+	page = alloc_page(GFP_KERNEL);
+	locations = kmalloc(sizeof(struct nfs4_fs_locations), GFP_KERNEL);
+	if (page == NULL || locations == NULL) {
+		dprintk("<-- %s: no memory\n", __func__);
+		goto out;
+	}
+
+	inode = d_inode(server->super->s_root);
+	result = nfs4_proc_get_locations(inode, locations, page, cred);
+	if (result) {
+		dprintk("<-- %s: failed to retrieve fs_locations: %d\n",
+			__func__, result);
+		goto out;
+	}
+
+	result = -NFS4ERR_NXIO;
+	if (!locations->nlocations)
+		goto out;
+
+	if (!(locations->fattr.valid & NFS_ATTR_FATTR_V4_LOCATIONS)) {
+		dprintk("<-- %s: No fs_locations data, migration skipped\n",
+			__func__);
+		goto out;
+	}
+
+	status = nfs4_begin_drain_session(clp);
+	if (status != 0) {
+		result = status;
+		goto out;
+	}
+
+	status = nfs4_replace_transport(server, locations);
+	if (status != 0) {
+		dprintk("<-- %s: failed to replace transport: %d\n",
+			__func__, status);
+		goto out;
+	}
+
+	result = 0;
+	dprintk("<-- %s: migration succeeded\n", __func__);
+
+out:
+	if (page != NULL)
+		__free_page(page);
+	kfree(locations);
+	if (result) {
+		pr_err("NFS: migration recovery failed (server %s)\n",
+				clp->cl_hostname);
+		set_bit(NFS_MIG_FAILED, &server->mig_status);
+	}
+	return result;
+}
+
+/*
+ * Returns zero or a negative NFS4ERR status code.
+ */
+static int nfs4_handle_migration(struct nfs_client *clp)
+{
+	const struct nfs4_state_maintenance_ops *ops =
+				clp->cl_mvops->state_renewal_ops;
+	struct nfs_server *server;
+	const struct cred *cred;
+
+	dprintk("%s: migration reported on \"%s\"\n", __func__,
+			clp->cl_hostname);
+
+	cred = ops->get_state_renewal_cred(clp);
+	if (cred == NULL)
+		return -NFS4ERR_NOENT;
+
+	clp->cl_mig_gen++;
+restart:
+	rcu_read_lock();
+	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
+		int status;
+
+		if (server->mig_gen == clp->cl_mig_gen)
+			continue;
+		server->mig_gen = clp->cl_mig_gen;
+
+		if (!test_and_clear_bit(NFS_MIG_IN_TRANSITION,
+						&server->mig_status))
+			continue;
+
+		rcu_read_unlock();
+		status = nfs4_try_migration(server, cred);
+		if (status < 0) {
+			put_cred(cred);
+			return status;
+		}
+		goto restart;
+	}
+	rcu_read_unlock();
+	put_cred(cred);
+	return 0;
+}
+
+/*
+ * Test each nfs_server on the clp's cl_superblocks list to see
+ * if it's moved to another server.  Stop when the server no longer
+ * returns NFS4ERR_LEASE_MOVED.
+ */
+static int nfs4_handle_lease_moved(struct nfs_client *clp)
+{
+	const struct nfs4_state_maintenance_ops *ops =
+				clp->cl_mvops->state_renewal_ops;
+	struct nfs_server *server;
+	const struct cred *cred;
+
+	dprintk("%s: lease moved reported on \"%s\"\n", __func__,
+			clp->cl_hostname);
+
+	cred = ops->get_state_renewal_cred(clp);
+	if (cred == NULL)
+		return -NFS4ERR_NOENT;
+
+	clp->cl_mig_gen++;
+restart:
+	rcu_read_lock();
+	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
+		struct inode *inode;
+		int status;
+
+		if (server->mig_gen == clp->cl_mig_gen)
+			continue;
+		server->mig_gen = clp->cl_mig_gen;
+
+		rcu_read_unlock();
+
+		inode = d_inode(server->super->s_root);
+		status = nfs4_proc_fsid_present(inode, cred);
+		if (status != -NFS4ERR_MOVED)
+			goto restart;	/* wasn't this one */
+		if (nfs4_try_migration(server, cred) == -NFS4ERR_LEASE_MOVED)
+			goto restart;	/* there are more */
+		goto out;
+	}
+	rcu_read_unlock();
+
+out:
+	put_cred(cred);
+	return 0;
+}
+
+/**
+ * nfs4_discover_server_trunking - Detect server IP address trunking
+ *
+ * @clp: nfs_client under test
+ * @result: OUT: found nfs_client, or clp
+ *
+ * Returns zero or a negative errno.  If zero is returned,
+ * an nfs_client pointer is planted in "result".
+ *
+ * Note: since we are invoked in process context, and
+ * not from inside the state manager, we cannot use
+ * nfs4_handle_reclaim_lease_error().
+ */
+int nfs4_discover_server_trunking(struct nfs_client *clp,
+				  struct nfs_client **result)
+{
+	const struct nfs4_state_recovery_ops *ops =
+				clp->cl_mvops->reboot_recovery_ops;
+	struct rpc_clnt *clnt;
+	const struct cred *cred;
+	int i, status;
+
+	dprintk("NFS: %s: testing '%s'\n", __func__, clp->cl_hostname);
+
+	clnt = clp->cl_rpcclient;
+	i = 0;
+
+	mutex_lock(&nfs_clid_init_mutex);
+again:
+	status  = -ENOENT;
+	cred = nfs4_get_clid_cred(clp);
+	if (cred == NULL)
+		goto out_unlock;
+
+	status = ops->detect_trunking(clp, result, cred);
+	put_cred(cred);
+	switch (status) {
+	case 0:
+	case -EINTR:
+	case -ERESTARTSYS:
+		break;
+	case -ETIMEDOUT:
+		if (clnt->cl_softrtry)
+			break;
+		fallthrough;
+	case -NFS4ERR_DELAY:
+	case -EAGAIN:
+		ssleep(1);
+		fallthrough;
+	case -NFS4ERR_STALE_CLIENTID:
+		dprintk("NFS: %s after status %d, retrying\n",
+			__func__, status);
+		goto again;
+	case -EACCES:
+		if (i++ == 0) {
+			nfs4_root_machine_cred(clp);
+			goto again;
+		}
+		if (clnt->cl_auth->au_flavor == RPC_AUTH_UNIX)
+			break;
+		fallthrough;
+	case -NFS4ERR_CLID_INUSE:
+	case -NFS4ERR_WRONGSEC:
+		/* No point in retrying if we already used RPC_AUTH_UNIX */
+		if (clnt->cl_auth->au_flavor == RPC_AUTH_UNIX) {
+			status = -EPERM;
+			break;
+		}
+		clnt = rpc_clone_client_set_auth(clnt, RPC_AUTH_UNIX);
+		if (IS_ERR(clnt)) {
+			status = PTR_ERR(clnt);
+			break;
+		}
+		/* Note: this is safe because we haven't yet marked the
+		 * client as ready, so we are the only user of
+		 * clp->cl_rpcclient
+		 */
+		clnt = xchg(&clp->cl_rpcclient, clnt);
+		rpc_shutdown_client(clnt);
+		clnt = clp->cl_rpcclient;
+		goto again;
+
+	case -NFS4ERR_MINOR_VERS_MISMATCH:
+		status = -EPROTONOSUPPORT;
+		break;
+
+	case -EKEYEXPIRED:
+	case -NFS4ERR_NOT_SAME: /* FixMe: implement recovery
+				 * in nfs4_exchange_id */
+		status = -EKEYEXPIRED;
+		break;
+	default:
+		pr_warn("NFS: %s unhandled error %d. Exiting with error EIO\n",
+				__func__, status);
+		status = -EIO;
+	}
+
+out_unlock:
+	mutex_unlock(&nfs_clid_init_mutex);
+	dprintk("NFS: %s: status = %d\n", __func__, status);
+	return status;
+}
+
+#ifdef CONFIG_NFS_V4_1
+void nfs4_schedule_session_recovery(struct nfs4_session *session, int err)
+{
+	struct nfs_client *clp = session->clp;
+
+	switch (err) {
+	default:
+		set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
+		break;
+	case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
+		set_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
+	}
+	nfs4_schedule_state_manager(clp);
+}
+EXPORT_SYMBOL_GPL(nfs4_schedule_session_recovery);
+
+void nfs41_notify_server(struct nfs_client *clp)
+{
+	/* Use CHECK_LEASE to ping the server with a SEQUENCE */
+	set_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
+	nfs4_schedule_state_manager(clp);
+}
+
+static void nfs4_reset_all_state(struct nfs_client *clp)
+{
+	if (test_and_set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) == 0) {
+		set_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state);
+		clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
+		nfs4_state_start_reclaim_nograce(clp);
+		dprintk("%s: scheduling reset of all state for server %s!\n",
+				__func__, clp->cl_hostname);
+		nfs4_schedule_state_manager(clp);
+	}
+}
+
+static void nfs41_handle_server_reboot(struct nfs_client *clp)
+{
+	if (test_and_set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) == 0) {
+		nfs4_state_start_reclaim_reboot(clp);
+		dprintk("%s: server %s rebooted!\n", __func__,
+				clp->cl_hostname);
+		nfs4_schedule_state_manager(clp);
+	}
+}
+
+static void nfs41_handle_all_state_revoked(struct nfs_client *clp)
+{
+	nfs4_reset_all_state(clp);
+	dprintk("%s: state revoked on server %s\n", __func__, clp->cl_hostname);
+}
+
+static void nfs41_handle_some_state_revoked(struct nfs_client *clp)
+{
+	nfs4_state_start_reclaim_nograce(clp);
+	nfs4_schedule_state_manager(clp);
+
+	dprintk("%s: state revoked on server %s\n", __func__, clp->cl_hostname);
+}
+
+static void nfs41_handle_recallable_state_revoked(struct nfs_client *clp)
+{
+	/* FIXME: For now, we destroy all layouts. */
+	pnfs_destroy_all_layouts(clp);
+	nfs_test_expired_all_delegations(clp);
+	dprintk("%s: Recallable state revoked on server %s!\n", __func__,
+			clp->cl_hostname);
+}
+
+static void nfs41_handle_backchannel_fault(struct nfs_client *clp)
+{
+	set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
+	nfs4_schedule_state_manager(clp);
+
+	dprintk("%s: server %s declared a backchannel fault\n", __func__,
+			clp->cl_hostname);
+}
+
+static void nfs41_handle_cb_path_down(struct nfs_client *clp)
+{
+	if (test_and_set_bit(NFS4CLNT_BIND_CONN_TO_SESSION,
+		&clp->cl_state) == 0)
+		nfs4_schedule_state_manager(clp);
+}
+
+void nfs41_handle_sequence_flag_errors(struct nfs_client *clp, u32 flags,
+		bool recovery)
+{
+	if (!flags)
+		return;
+
+	dprintk("%s: \"%s\" (client ID %llx) flags=0x%08x\n",
+		__func__, clp->cl_hostname, clp->cl_clientid, flags);
+	/*
+	 * If we're called from the state manager thread, then assume we're
+	 * already handling the RECLAIM_NEEDED and/or STATE_REVOKED.
+	 * Those flags are expected to remain set until we're done
+	 * recovering (see RFC5661, section 18.46.3).
+	 */
+	if (recovery)
+		goto out_recovery;
+
+	if (flags & SEQ4_STATUS_RESTART_RECLAIM_NEEDED)
+		nfs41_handle_server_reboot(clp);
+	if (flags & (SEQ4_STATUS_EXPIRED_ALL_STATE_REVOKED))
+		nfs41_handle_all_state_revoked(clp);
+	if (flags & (SEQ4_STATUS_EXPIRED_SOME_STATE_REVOKED |
+			    SEQ4_STATUS_ADMIN_STATE_REVOKED))
+		nfs41_handle_some_state_revoked(clp);
+	if (flags & SEQ4_STATUS_LEASE_MOVED)
+		nfs4_schedule_lease_moved_recovery(clp);
+	if (flags & SEQ4_STATUS_RECALLABLE_STATE_REVOKED)
+		nfs41_handle_recallable_state_revoked(clp);
+out_recovery:
+	if (flags & SEQ4_STATUS_BACKCHANNEL_FAULT)
+		nfs41_handle_backchannel_fault(clp);
+	else if (flags & (SEQ4_STATUS_CB_PATH_DOWN |
+				SEQ4_STATUS_CB_PATH_DOWN_SESSION))
+		nfs41_handle_cb_path_down(clp);
+}
+
+static int nfs4_reset_session(struct nfs_client *clp)
+{
+	const struct cred *cred;
+	int status;
+
+	if (!nfs4_has_session(clp))
+		return 0;
+	status = nfs4_begin_drain_session(clp);
+	if (status != 0)
+		return status;
+	cred = nfs4_get_clid_cred(clp);
+	status = nfs4_proc_destroy_session(clp->cl_session, cred);
+	switch (status) {
+	case 0:
+	case -NFS4ERR_BADSESSION:
+	case -NFS4ERR_DEADSESSION:
+		break;
+	case -NFS4ERR_BACK_CHAN_BUSY:
+	case -NFS4ERR_DELAY:
+		set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
+		status = 0;
+		ssleep(1);
+		goto out;
+	default:
+		status = nfs4_recovery_handle_error(clp, status);
+		goto out;
+	}
+
+	memset(clp->cl_session->sess_id.data, 0, NFS4_MAX_SESSIONID_LEN);
+	status = nfs4_proc_create_session(clp, cred);
+	if (status) {
+		dprintk("%s: session reset failed with status %d for server %s!\n",
+			__func__, status, clp->cl_hostname);
+		status = nfs4_handle_reclaim_lease_error(clp, status);
+		goto out;
+	}
+	nfs41_finish_session_reset(clp);
+	dprintk("%s: session reset was successful for server %s!\n",
+			__func__, clp->cl_hostname);
+out:
+	put_cred(cred);
+	return status;
+}
+
+static int nfs4_bind_conn_to_session(struct nfs_client *clp)
+{
+	const struct cred *cred;
+	int ret;
+
+	if (!nfs4_has_session(clp))
+		return 0;
+	ret = nfs4_begin_drain_session(clp);
+	if (ret != 0)
+		return ret;
+	cred = nfs4_get_clid_cred(clp);
+	ret = nfs4_proc_bind_conn_to_session(clp, cred);
+	put_cred(cred);
+	clear_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
+	switch (ret) {
+	case 0:
+		dprintk("%s: bind_conn_to_session was successful for server %s!\n",
+			__func__, clp->cl_hostname);
+		break;
+	case -NFS4ERR_DELAY:
+		ssleep(1);
+		set_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
+		break;
+	default:
+		return nfs4_recovery_handle_error(clp, ret);
+	}
+	return 0;
+}
+
+static void nfs4_layoutreturn_any_run(struct nfs_client *clp)
+{
+	int iomode = 0;
+
+	if (test_and_clear_bit(NFS4CLNT_RECALL_ANY_LAYOUT_READ, &clp->cl_state))
+		iomode += IOMODE_READ;
+	if (test_and_clear_bit(NFS4CLNT_RECALL_ANY_LAYOUT_RW, &clp->cl_state))
+		iomode += IOMODE_RW;
+	/* Note: IOMODE_READ + IOMODE_RW == IOMODE_ANY */
+	if (iomode) {
+		pnfs_layout_return_unused_byclid(clp, iomode);
+		set_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state);
+	}
+}
+#else /* CONFIG_NFS_V4_1 */
+static int nfs4_reset_session(struct nfs_client *clp) { return 0; }
+
+static int nfs4_bind_conn_to_session(struct nfs_client *clp)
+{
+	return 0;
+}
+
+static void nfs4_layoutreturn_any_run(struct nfs_client *clp)
+{
+}
+#endif /* CONFIG_NFS_V4_1 */
+
+static void nfs4_state_manager(struct nfs_client *clp)
+{
+	unsigned int memflags;
+	int status = 0;
+	const char *section = "", *section_sep = "";
+
+	/*
+	 * State recovery can deadlock if the direct reclaim code tries
+	 * start NFS writeback. So ensure memory allocations are all
+	 * GFP_NOFS.
+	 */
+	memflags = memalloc_nofs_save();
+
+	/* Ensure exclusive access to NFSv4 state */
+	do {
+		trace_nfs4_state_mgr(clp);
+		clear_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state);
+		if (test_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state)) {
+			section = "purge state";
+			status = nfs4_purge_lease(clp);
+			if (status < 0)
+				goto out_error;
+			continue;
+		}
+
+		if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state)) {
+			section = "lease expired";
+			/* We're going to have to re-establish a clientid */
+			status = nfs4_reclaim_lease(clp);
+			if (status < 0)
+				goto out_error;
+			continue;
+		}
+
+		/* Initialize or reset the session */
+		if (test_and_clear_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state)) {
+			section = "reset session";
+			status = nfs4_reset_session(clp);
+			if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
+				continue;
+			if (status < 0)
+				goto out_error;
+		}
+
+		/* Send BIND_CONN_TO_SESSION */
+		if (test_and_clear_bit(NFS4CLNT_BIND_CONN_TO_SESSION,
+				&clp->cl_state)) {
+			section = "bind conn to session";
+			status = nfs4_bind_conn_to_session(clp);
+			if (status < 0)
+				goto out_error;
+			continue;
+		}
+
+		if (test_and_clear_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state)) {
+			section = "check lease";
+			status = nfs4_check_lease(clp);
+			if (status < 0)
+				goto out_error;
+			continue;
+		}
+
+		if (test_and_clear_bit(NFS4CLNT_MOVED, &clp->cl_state)) {
+			section = "migration";
+			status = nfs4_handle_migration(clp);
+			if (status < 0)
+				goto out_error;
+		}
+
+		if (test_and_clear_bit(NFS4CLNT_LEASE_MOVED, &clp->cl_state)) {
+			section = "lease moved";
+			status = nfs4_handle_lease_moved(clp);
+			if (status < 0)
+				goto out_error;
+		}
+
+		/* First recover reboot state... */
+		if (test_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state)) {
+			section = "reclaim reboot";
+			status = nfs4_do_reclaim(clp,
+				clp->cl_mvops->reboot_recovery_ops);
+			if (status == -EAGAIN)
+				continue;
+			if (status < 0)
+				goto out_error;
+			nfs4_state_end_reclaim_reboot(clp);
+			continue;
+		}
+
+		/* Detect expired delegations... */
+		if (test_and_clear_bit(NFS4CLNT_DELEGATION_EXPIRED, &clp->cl_state)) {
+			section = "detect expired delegations";
+			nfs_reap_expired_delegations(clp);
+			continue;
+		}
+
+		/* Now recover expired state... */
+		if (test_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state)) {
+			section = "reclaim nograce";
+			status = nfs4_do_reclaim(clp,
+				clp->cl_mvops->nograce_recovery_ops);
+			if (status == -EAGAIN)
+				continue;
+			if (status < 0)
+				goto out_error;
+			clear_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state);
+		}
+
+		memalloc_nofs_restore(memflags);
+		nfs4_end_drain_session(clp);
+		nfs4_clear_state_manager_bit(clp);
+
+		if (test_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state) &&
+		    !test_and_set_bit(NFS4CLNT_MANAGER_RUNNING,
+				      &clp->cl_state)) {
+			memflags = memalloc_nofs_save();
+			continue;
+		}
+
+		if (!test_and_set_bit(NFS4CLNT_RECALL_RUNNING, &clp->cl_state)) {
+			if (test_and_clear_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state)) {
+				nfs_client_return_marked_delegations(clp);
+				set_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state);
+			}
+			nfs4_layoutreturn_any_run(clp);
+			clear_bit(NFS4CLNT_RECALL_RUNNING, &clp->cl_state);
+		}
+
+		return;
+
+	} while (refcount_read(&clp->cl_count) > 1 && !signalled());
+	goto out_drain;
+
+out_error:
+	if (strlen(section))
+		section_sep = ": ";
+	trace_nfs4_state_mgr_failed(clp, section, status);
+	pr_warn_ratelimited("NFS: state manager%s%s failed on NFSv4 server %s"
+			" with error %d\n", section_sep, section,
+			clp->cl_hostname, -status);
+	ssleep(1);
+out_drain:
+	memalloc_nofs_restore(memflags);
+	nfs4_end_drain_session(clp);
+	nfs4_clear_state_manager_bit(clp);
+}
+
+static int nfs4_run_state_manager(void *ptr)
+{
+	struct nfs_client *clp = ptr;
+	struct rpc_clnt *cl = clp->cl_rpcclient;
+
+	while (cl != cl->cl_parent)
+		cl = cl->cl_parent;
+
+	allow_signal(SIGKILL);
+again:
+	nfs4_state_manager(clp);
+
+	if (test_bit(NFS4CLNT_MANAGER_AVAILABLE, &clp->cl_state) &&
+	    !test_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state)) {
+		wait_var_event_interruptible(&clp->cl_state,
+					     test_bit(NFS4CLNT_RUN_MANAGER,
+						      &clp->cl_state));
+		if (!atomic_read(&cl->cl_swapper))
+			clear_bit(NFS4CLNT_MANAGER_AVAILABLE, &clp->cl_state);
+		if (refcount_read(&clp->cl_count) > 1 && !signalled() &&
+		    !test_and_set_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state))
+			goto again;
+		/* Either no longer a swapper, or were signalled */
+		clear_bit(NFS4CLNT_MANAGER_AVAILABLE, &clp->cl_state);
+	}
+
+	if (refcount_read(&clp->cl_count) > 1 && !signalled() &&
+	    test_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state) &&
+	    !test_and_set_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state))
+		goto again;
+
+	nfs_put_client(clp);
+	module_put_and_exit(0);
+	return 0;
+}
+
+/*
+ * Local variables:
+ *  c-basic-offset: 8
+ * End:
+ */
diff --git a/fs/nfs/nfs4super.c b/fs/nfs/nfs4super.c
new file mode 100644
index 000000000..d09bcfd7d
--- /dev/null
+++ b/fs/nfs/nfs4super.c
@@ -0,0 +1,314 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2012 Bryan Schumaker <bjschuma@netapp.com>
+ */
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/mount.h>
+#include <linux/nfs4_mount.h>
+#include <linux/nfs_fs.h>
+#include <linux/nfs_ssc.h>
+#include "delegation.h"
+#include "internal.h"
+#include "nfs4_fs.h"
+#include "nfs4idmap.h"
+#include "dns_resolve.h"
+#include "pnfs.h"
+#include "nfs.h"
+
+#define NFSDBG_FACILITY		NFSDBG_VFS
+
+static int nfs4_write_inode(struct inode *inode, struct writeback_control *wbc);
+static void nfs4_evict_inode(struct inode *inode);
+
+static const struct super_operations nfs4_sops = {
+	.alloc_inode	= nfs_alloc_inode,
+	.free_inode	= nfs_free_inode,
+	.write_inode	= nfs4_write_inode,
+	.drop_inode	= nfs_drop_inode,
+	.statfs		= nfs_statfs,
+	.evict_inode	= nfs4_evict_inode,
+	.umount_begin	= nfs_umount_begin,
+	.show_options	= nfs_show_options,
+	.show_devname	= nfs_show_devname,
+	.show_path	= nfs_show_path,
+	.show_stats	= nfs_show_stats,
+};
+
+struct nfs_subversion nfs_v4 = {
+	.owner		= THIS_MODULE,
+	.nfs_fs		= &nfs4_fs_type,
+	.rpc_vers	= &nfs_version4,
+	.rpc_ops	= &nfs_v4_clientops,
+	.sops		= &nfs4_sops,
+	.xattr		= nfs4_xattr_handlers,
+};
+
+static int nfs4_write_inode(struct inode *inode, struct writeback_control *wbc)
+{
+	int ret = nfs_write_inode(inode, wbc);
+
+	if (ret == 0)
+		ret = pnfs_layoutcommit_inode(inode,
+				wbc->sync_mode == WB_SYNC_ALL);
+	return ret;
+}
+
+/*
+ * Clean out any remaining NFSv4 state that might be left over due
+ * to open() calls that passed nfs_atomic_lookup, but failed to call
+ * nfs_open().
+ */
+static void nfs4_evict_inode(struct inode *inode)
+{
+	truncate_inode_pages_final(&inode->i_data);
+	clear_inode(inode);
+	/* If we are holding a delegation, return and free it */
+	nfs_inode_evict_delegation(inode);
+	/* Note that above delegreturn would trigger pnfs return-on-close */
+	pnfs_return_layout(inode);
+	pnfs_destroy_layout_final(NFS_I(inode));
+	/* First call standard NFS clear_inode() code */
+	nfs_clear_inode(inode);
+	nfs4_xattr_cache_zap(inode);
+}
+
+struct nfs_referral_count {
+	struct list_head list;
+	const struct task_struct *task;
+	unsigned int referral_count;
+};
+
+static LIST_HEAD(nfs_referral_count_list);
+static DEFINE_SPINLOCK(nfs_referral_count_list_lock);
+
+static struct nfs_referral_count *nfs_find_referral_count(void)
+{
+	struct nfs_referral_count *p;
+
+	list_for_each_entry(p, &nfs_referral_count_list, list) {
+		if (p->task == current)
+			return p;
+	}
+	return NULL;
+}
+
+#define NFS_MAX_NESTED_REFERRALS 2
+
+static int nfs_referral_loop_protect(void)
+{
+	struct nfs_referral_count *p, *new;
+	int ret = -ENOMEM;
+
+	new = kmalloc(sizeof(*new), GFP_KERNEL);
+	if (!new)
+		goto out;
+	new->task = current;
+	new->referral_count = 1;
+
+	ret = 0;
+	spin_lock(&nfs_referral_count_list_lock);
+	p = nfs_find_referral_count();
+	if (p != NULL) {
+		if (p->referral_count >= NFS_MAX_NESTED_REFERRALS)
+			ret = -ELOOP;
+		else
+			p->referral_count++;
+	} else {
+		list_add(&new->list, &nfs_referral_count_list);
+		new = NULL;
+	}
+	spin_unlock(&nfs_referral_count_list_lock);
+	kfree(new);
+out:
+	return ret;
+}
+
+static void nfs_referral_loop_unprotect(void)
+{
+	struct nfs_referral_count *p;
+
+	spin_lock(&nfs_referral_count_list_lock);
+	p = nfs_find_referral_count();
+	p->referral_count--;
+	if (p->referral_count == 0)
+		list_del(&p->list);
+	else
+		p = NULL;
+	spin_unlock(&nfs_referral_count_list_lock);
+	kfree(p);
+}
+
+static int do_nfs4_mount(struct nfs_server *server,
+			 struct fs_context *fc,
+			 const char *hostname,
+			 const char *export_path)
+{
+	struct nfs_fs_context *root_ctx;
+	struct fs_context *root_fc;
+	struct vfsmount *root_mnt;
+	struct dentry *dentry;
+	size_t len;
+	int ret;
+
+	struct fs_parameter param = {
+		.key	= "source",
+		.type	= fs_value_is_string,
+		.dirfd	= -1,
+	};
+
+	if (IS_ERR(server))
+		return PTR_ERR(server);
+
+	root_fc = vfs_dup_fs_context(fc);
+	if (IS_ERR(root_fc)) {
+		nfs_free_server(server);
+		return PTR_ERR(root_fc);
+	}
+	kfree(root_fc->source);
+	root_fc->source = NULL;
+
+	root_ctx = nfs_fc2context(root_fc);
+	root_ctx->internal = true;
+	root_ctx->server = server;
+	/* We leave export_path unset as it's not used to find the root. */
+
+	len = strlen(hostname) + 5;
+	param.string = kmalloc(len, GFP_KERNEL);
+	if (param.string == NULL) {
+		put_fs_context(root_fc);
+		return -ENOMEM;
+	}
+
+	/* Does hostname needs to be enclosed in brackets? */
+	if (strchr(hostname, ':'))
+		param.size = snprintf(param.string, len, "[%s]:/", hostname);
+	else
+		param.size = snprintf(param.string, len, "%s:/", hostname);
+	ret = vfs_parse_fs_param(root_fc, &param);
+	kfree(param.string);
+	if (ret < 0) {
+		put_fs_context(root_fc);
+		return ret;
+	}
+	root_mnt = fc_mount(root_fc);
+	put_fs_context(root_fc);
+
+	if (IS_ERR(root_mnt))
+		return PTR_ERR(root_mnt);
+
+	ret = nfs_referral_loop_protect();
+	if (ret) {
+		mntput(root_mnt);
+		return ret;
+	}
+
+	dentry = mount_subtree(root_mnt, export_path);
+	nfs_referral_loop_unprotect();
+
+	if (IS_ERR(dentry))
+		return PTR_ERR(dentry);
+
+	fc->root = dentry;
+	return 0;
+}
+
+int nfs4_try_get_tree(struct fs_context *fc)
+{
+	struct nfs_fs_context *ctx = nfs_fc2context(fc);
+	int err;
+
+	dfprintk(MOUNT, "--> nfs4_try_get_tree()\n");
+
+	/* We create a mount for the server's root, walk to the requested
+	 * location and then create another mount for that.
+	 */
+	err= do_nfs4_mount(nfs4_create_server(fc),
+			   fc, ctx->nfs_server.hostname,
+			   ctx->nfs_server.export_path);
+	if (err) {
+		nfs_ferrorf(fc, MOUNT, "NFS4: Couldn't follow remote path");
+		dfprintk(MOUNT, "<-- nfs4_try_get_tree() = %d [error]\n", err);
+	} else {
+		dfprintk(MOUNT, "<-- nfs4_try_get_tree() = 0\n");
+	}
+	return err;
+}
+
+/*
+ * Create an NFS4 server record on referral traversal
+ */
+int nfs4_get_referral_tree(struct fs_context *fc)
+{
+	struct nfs_fs_context *ctx = nfs_fc2context(fc);
+	int err;
+
+	dprintk("--> nfs4_referral_mount()\n");
+
+	/* create a new volume representation */
+	err = do_nfs4_mount(nfs4_create_referral_server(fc),
+			    fc, ctx->nfs_server.hostname,
+			    ctx->nfs_server.export_path);
+	if (err) {
+		nfs_ferrorf(fc, MOUNT, "NFS4: Couldn't follow remote path");
+		dfprintk(MOUNT, "<-- nfs4_get_referral_tree() = %d [error]\n", err);
+	} else {
+		dfprintk(MOUNT, "<-- nfs4_get_referral_tree() = 0\n");
+	}
+	return err;
+}
+
+static int __init init_nfs_v4(void)
+{
+	int err;
+
+	err = nfs_dns_resolver_init();
+	if (err)
+		goto out;
+
+	err = nfs_idmap_init();
+	if (err)
+		goto out1;
+
+#ifdef CONFIG_NFS_V4_2
+	err = nfs4_xattr_cache_init();
+	if (err)
+		goto out2;
+#endif
+
+	err = nfs4_register_sysctl();
+	if (err)
+		goto out2;
+
+#ifdef CONFIG_NFS_V4_2
+	nfs42_ssc_register_ops();
+#endif
+	register_nfs_version(&nfs_v4);
+	return 0;
+out2:
+	nfs_idmap_quit();
+out1:
+	nfs_dns_resolver_destroy();
+out:
+	return err;
+}
+
+static void __exit exit_nfs_v4(void)
+{
+	/* Not called in the _init(), conditionally loaded */
+	nfs4_pnfs_v3_ds_connect_unload();
+
+	unregister_nfs_version(&nfs_v4);
+#ifdef CONFIG_NFS_V4_2
+	nfs4_xattr_cache_exit();
+	nfs42_ssc_unregister_ops();
+#endif
+	nfs4_unregister_sysctl();
+	nfs_idmap_quit();
+	nfs_dns_resolver_destroy();
+}
+
+MODULE_LICENSE("GPL");
+
+module_init(init_nfs_v4);
+module_exit(exit_nfs_v4);
diff --git a/fs/nfs/nfs4sysctl.c b/fs/nfs/nfs4sysctl.c
new file mode 100644
index 000000000..c394e4447
--- /dev/null
+++ b/fs/nfs/nfs4sysctl.c
@@ -0,0 +1,70 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/nfs/nfs4sysctl.c
+ *
+ * Sysctl interface to NFS v4 parameters
+ *
+ * Copyright (c) 2006 Trond Myklebust <Trond.Myklebust@netapp.com>
+ */
+#include <linux/sysctl.h>
+#include <linux/nfs_fs.h>
+
+#include "nfs4_fs.h"
+#include "nfs4idmap.h"
+#include "callback.h"
+
+static const int nfs_set_port_min;
+static const int nfs_set_port_max = 65535;
+static struct ctl_table_header *nfs4_callback_sysctl_table;
+
+static struct ctl_table nfs4_cb_sysctls[] = {
+	{
+		.procname = "nfs_callback_tcpport",
+		.data = &nfs_callback_set_tcpport,
+		.maxlen = sizeof(int),
+		.mode = 0644,
+		.proc_handler = proc_dointvec_minmax,
+		.extra1 = (int *)&nfs_set_port_min,
+		.extra2 = (int *)&nfs_set_port_max,
+	},
+	{
+		.procname = "idmap_cache_timeout",
+		.data = &nfs_idmap_cache_timeout,
+		.maxlen = sizeof(int),
+		.mode = 0644,
+		.proc_handler = proc_dointvec,
+	},
+	{ }
+};
+
+static struct ctl_table nfs4_cb_sysctl_dir[] = {
+	{
+		.procname = "nfs",
+		.mode = 0555,
+		.child = nfs4_cb_sysctls,
+	},
+	{ }
+};
+
+static struct ctl_table nfs4_cb_sysctl_root[] = {
+	{
+		.procname = "fs",
+		.mode = 0555,
+		.child = nfs4_cb_sysctl_dir,
+	},
+	{ }
+};
+
+int nfs4_register_sysctl(void)
+{
+	nfs4_callback_sysctl_table = register_sysctl_table(nfs4_cb_sysctl_root);
+	if (nfs4_callback_sysctl_table == NULL)
+		return -ENOMEM;
+	return 0;
+}
+
+void nfs4_unregister_sysctl(void)
+{
+	unregister_sysctl_table(nfs4_callback_sysctl_table);
+	nfs4_callback_sysctl_table = NULL;
+}
diff --git a/fs/nfs/nfs4trace.c b/fs/nfs/nfs4trace.c
new file mode 100644
index 000000000..d9ac556be
--- /dev/null
+++ b/fs/nfs/nfs4trace.c
@@ -0,0 +1,31 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2013 Trond Myklebust <Trond.Myklebust@netapp.com>
+ */
+#include <linux/nfs_fs.h>
+#include "nfs4_fs.h"
+#include "internal.h"
+#include "nfs4session.h"
+#include "callback.h"
+#include "pnfs.h"
+
+#define CREATE_TRACE_POINTS
+#include "nfs4trace.h"
+
+#ifdef CONFIG_NFS_V4_1
+EXPORT_TRACEPOINT_SYMBOL_GPL(nfs4_pnfs_read);
+EXPORT_TRACEPOINT_SYMBOL_GPL(nfs4_pnfs_write);
+EXPORT_TRACEPOINT_SYMBOL_GPL(nfs4_pnfs_commit_ds);
+
+EXPORT_TRACEPOINT_SYMBOL_GPL(pnfs_mds_fallback_pg_init_read);
+EXPORT_TRACEPOINT_SYMBOL_GPL(pnfs_mds_fallback_pg_init_write);
+EXPORT_TRACEPOINT_SYMBOL_GPL(pnfs_mds_fallback_pg_get_mirror_count);
+EXPORT_TRACEPOINT_SYMBOL_GPL(pnfs_mds_fallback_read_done);
+EXPORT_TRACEPOINT_SYMBOL_GPL(pnfs_mds_fallback_write_done);
+EXPORT_TRACEPOINT_SYMBOL_GPL(pnfs_mds_fallback_read_pagelist);
+EXPORT_TRACEPOINT_SYMBOL_GPL(pnfs_mds_fallback_write_pagelist);
+
+EXPORT_TRACEPOINT_SYMBOL_GPL(ff_layout_read_error);
+EXPORT_TRACEPOINT_SYMBOL_GPL(ff_layout_write_error);
+EXPORT_TRACEPOINT_SYMBOL_GPL(ff_layout_commit_error);
+#endif
diff --git a/fs/nfs/nfs4trace.h b/fs/nfs/nfs4trace.h
new file mode 100644
index 000000000..d862df976
--- /dev/null
+++ b/fs/nfs/nfs4trace.h
@@ -0,0 +1,2311 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2013 Trond Myklebust <Trond.Myklebust@netapp.com>
+ */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM nfs4
+
+#if !defined(_TRACE_NFS4_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_NFS4_H
+
+#include <linux/tracepoint.h>
+
+TRACE_DEFINE_ENUM(EPERM);
+TRACE_DEFINE_ENUM(ENOENT);
+TRACE_DEFINE_ENUM(EIO);
+TRACE_DEFINE_ENUM(ENXIO);
+TRACE_DEFINE_ENUM(EACCES);
+TRACE_DEFINE_ENUM(EEXIST);
+TRACE_DEFINE_ENUM(EXDEV);
+TRACE_DEFINE_ENUM(ENOTDIR);
+TRACE_DEFINE_ENUM(EISDIR);
+TRACE_DEFINE_ENUM(EFBIG);
+TRACE_DEFINE_ENUM(ENOSPC);
+TRACE_DEFINE_ENUM(EROFS);
+TRACE_DEFINE_ENUM(EMLINK);
+TRACE_DEFINE_ENUM(ENAMETOOLONG);
+TRACE_DEFINE_ENUM(ENOTEMPTY);
+TRACE_DEFINE_ENUM(EDQUOT);
+TRACE_DEFINE_ENUM(ESTALE);
+TRACE_DEFINE_ENUM(EBADHANDLE);
+TRACE_DEFINE_ENUM(EBADCOOKIE);
+TRACE_DEFINE_ENUM(ENOTSUPP);
+TRACE_DEFINE_ENUM(ETOOSMALL);
+TRACE_DEFINE_ENUM(EREMOTEIO);
+TRACE_DEFINE_ENUM(EBADTYPE);
+TRACE_DEFINE_ENUM(EAGAIN);
+TRACE_DEFINE_ENUM(ELOOP);
+TRACE_DEFINE_ENUM(EOPNOTSUPP);
+TRACE_DEFINE_ENUM(EDEADLK);
+TRACE_DEFINE_ENUM(ENOMEM);
+TRACE_DEFINE_ENUM(EKEYEXPIRED);
+TRACE_DEFINE_ENUM(ETIMEDOUT);
+TRACE_DEFINE_ENUM(ERESTARTSYS);
+TRACE_DEFINE_ENUM(ECONNREFUSED);
+TRACE_DEFINE_ENUM(ECONNRESET);
+TRACE_DEFINE_ENUM(ENETUNREACH);
+TRACE_DEFINE_ENUM(EHOSTUNREACH);
+TRACE_DEFINE_ENUM(EHOSTDOWN);
+TRACE_DEFINE_ENUM(EPIPE);
+TRACE_DEFINE_ENUM(EPFNOSUPPORT);
+TRACE_DEFINE_ENUM(EPROTONOSUPPORT);
+
+TRACE_DEFINE_ENUM(NFS4_OK);
+TRACE_DEFINE_ENUM(NFS4ERR_ACCESS);
+TRACE_DEFINE_ENUM(NFS4ERR_ATTRNOTSUPP);
+TRACE_DEFINE_ENUM(NFS4ERR_ADMIN_REVOKED);
+TRACE_DEFINE_ENUM(NFS4ERR_BACK_CHAN_BUSY);
+TRACE_DEFINE_ENUM(NFS4ERR_BADCHAR);
+TRACE_DEFINE_ENUM(NFS4ERR_BADHANDLE);
+TRACE_DEFINE_ENUM(NFS4ERR_BADIOMODE);
+TRACE_DEFINE_ENUM(NFS4ERR_BADLAYOUT);
+TRACE_DEFINE_ENUM(NFS4ERR_BADLABEL);
+TRACE_DEFINE_ENUM(NFS4ERR_BADNAME);
+TRACE_DEFINE_ENUM(NFS4ERR_BADOWNER);
+TRACE_DEFINE_ENUM(NFS4ERR_BADSESSION);
+TRACE_DEFINE_ENUM(NFS4ERR_BADSLOT);
+TRACE_DEFINE_ENUM(NFS4ERR_BADTYPE);
+TRACE_DEFINE_ENUM(NFS4ERR_BADXDR);
+TRACE_DEFINE_ENUM(NFS4ERR_BAD_COOKIE);
+TRACE_DEFINE_ENUM(NFS4ERR_BAD_HIGH_SLOT);
+TRACE_DEFINE_ENUM(NFS4ERR_BAD_RANGE);
+TRACE_DEFINE_ENUM(NFS4ERR_BAD_SEQID);
+TRACE_DEFINE_ENUM(NFS4ERR_BAD_SESSION_DIGEST);
+TRACE_DEFINE_ENUM(NFS4ERR_BAD_STATEID);
+TRACE_DEFINE_ENUM(NFS4ERR_CB_PATH_DOWN);
+TRACE_DEFINE_ENUM(NFS4ERR_CLID_INUSE);
+TRACE_DEFINE_ENUM(NFS4ERR_CLIENTID_BUSY);
+TRACE_DEFINE_ENUM(NFS4ERR_COMPLETE_ALREADY);
+TRACE_DEFINE_ENUM(NFS4ERR_CONN_NOT_BOUND_TO_SESSION);
+TRACE_DEFINE_ENUM(NFS4ERR_DEADLOCK);
+TRACE_DEFINE_ENUM(NFS4ERR_DEADSESSION);
+TRACE_DEFINE_ENUM(NFS4ERR_DELAY);
+TRACE_DEFINE_ENUM(NFS4ERR_DELEG_ALREADY_WANTED);
+TRACE_DEFINE_ENUM(NFS4ERR_DELEG_REVOKED);
+TRACE_DEFINE_ENUM(NFS4ERR_DENIED);
+TRACE_DEFINE_ENUM(NFS4ERR_DIRDELEG_UNAVAIL);
+TRACE_DEFINE_ENUM(NFS4ERR_DQUOT);
+TRACE_DEFINE_ENUM(NFS4ERR_ENCR_ALG_UNSUPP);
+TRACE_DEFINE_ENUM(NFS4ERR_EXIST);
+TRACE_DEFINE_ENUM(NFS4ERR_EXPIRED);
+TRACE_DEFINE_ENUM(NFS4ERR_FBIG);
+TRACE_DEFINE_ENUM(NFS4ERR_FHEXPIRED);
+TRACE_DEFINE_ENUM(NFS4ERR_FILE_OPEN);
+TRACE_DEFINE_ENUM(NFS4ERR_GRACE);
+TRACE_DEFINE_ENUM(NFS4ERR_HASH_ALG_UNSUPP);
+TRACE_DEFINE_ENUM(NFS4ERR_INVAL);
+TRACE_DEFINE_ENUM(NFS4ERR_IO);
+TRACE_DEFINE_ENUM(NFS4ERR_ISDIR);
+TRACE_DEFINE_ENUM(NFS4ERR_LAYOUTTRYLATER);
+TRACE_DEFINE_ENUM(NFS4ERR_LAYOUTUNAVAILABLE);
+TRACE_DEFINE_ENUM(NFS4ERR_LEASE_MOVED);
+TRACE_DEFINE_ENUM(NFS4ERR_LOCKED);
+TRACE_DEFINE_ENUM(NFS4ERR_LOCKS_HELD);
+TRACE_DEFINE_ENUM(NFS4ERR_LOCK_RANGE);
+TRACE_DEFINE_ENUM(NFS4ERR_MINOR_VERS_MISMATCH);
+TRACE_DEFINE_ENUM(NFS4ERR_MLINK);
+TRACE_DEFINE_ENUM(NFS4ERR_MOVED);
+TRACE_DEFINE_ENUM(NFS4ERR_NAMETOOLONG);
+TRACE_DEFINE_ENUM(NFS4ERR_NOENT);
+TRACE_DEFINE_ENUM(NFS4ERR_NOFILEHANDLE);
+TRACE_DEFINE_ENUM(NFS4ERR_NOMATCHING_LAYOUT);
+TRACE_DEFINE_ENUM(NFS4ERR_NOSPC);
+TRACE_DEFINE_ENUM(NFS4ERR_NOTDIR);
+TRACE_DEFINE_ENUM(NFS4ERR_NOTEMPTY);
+TRACE_DEFINE_ENUM(NFS4ERR_NOTSUPP);
+TRACE_DEFINE_ENUM(NFS4ERR_NOT_ONLY_OP);
+TRACE_DEFINE_ENUM(NFS4ERR_NOT_SAME);
+TRACE_DEFINE_ENUM(NFS4ERR_NO_GRACE);
+TRACE_DEFINE_ENUM(NFS4ERR_NXIO);
+TRACE_DEFINE_ENUM(NFS4ERR_OLD_STATEID);
+TRACE_DEFINE_ENUM(NFS4ERR_OPENMODE);
+TRACE_DEFINE_ENUM(NFS4ERR_OP_ILLEGAL);
+TRACE_DEFINE_ENUM(NFS4ERR_OP_NOT_IN_SESSION);
+TRACE_DEFINE_ENUM(NFS4ERR_PERM);
+TRACE_DEFINE_ENUM(NFS4ERR_PNFS_IO_HOLE);
+TRACE_DEFINE_ENUM(NFS4ERR_PNFS_NO_LAYOUT);
+TRACE_DEFINE_ENUM(NFS4ERR_RECALLCONFLICT);
+TRACE_DEFINE_ENUM(NFS4ERR_RECLAIM_BAD);
+TRACE_DEFINE_ENUM(NFS4ERR_RECLAIM_CONFLICT);
+TRACE_DEFINE_ENUM(NFS4ERR_REJECT_DELEG);
+TRACE_DEFINE_ENUM(NFS4ERR_REP_TOO_BIG);
+TRACE_DEFINE_ENUM(NFS4ERR_REP_TOO_BIG_TO_CACHE);
+TRACE_DEFINE_ENUM(NFS4ERR_REQ_TOO_BIG);
+TRACE_DEFINE_ENUM(NFS4ERR_RESOURCE);
+TRACE_DEFINE_ENUM(NFS4ERR_RESTOREFH);
+TRACE_DEFINE_ENUM(NFS4ERR_RETRY_UNCACHED_REP);
+TRACE_DEFINE_ENUM(NFS4ERR_RETURNCONFLICT);
+TRACE_DEFINE_ENUM(NFS4ERR_ROFS);
+TRACE_DEFINE_ENUM(NFS4ERR_SAME);
+TRACE_DEFINE_ENUM(NFS4ERR_SHARE_DENIED);
+TRACE_DEFINE_ENUM(NFS4ERR_SEQUENCE_POS);
+TRACE_DEFINE_ENUM(NFS4ERR_SEQ_FALSE_RETRY);
+TRACE_DEFINE_ENUM(NFS4ERR_SEQ_MISORDERED);
+TRACE_DEFINE_ENUM(NFS4ERR_SERVERFAULT);
+TRACE_DEFINE_ENUM(NFS4ERR_STALE);
+TRACE_DEFINE_ENUM(NFS4ERR_STALE_CLIENTID);
+TRACE_DEFINE_ENUM(NFS4ERR_STALE_STATEID);
+TRACE_DEFINE_ENUM(NFS4ERR_SYMLINK);
+TRACE_DEFINE_ENUM(NFS4ERR_TOOSMALL);
+TRACE_DEFINE_ENUM(NFS4ERR_TOO_MANY_OPS);
+TRACE_DEFINE_ENUM(NFS4ERR_UNKNOWN_LAYOUTTYPE);
+TRACE_DEFINE_ENUM(NFS4ERR_UNSAFE_COMPOUND);
+TRACE_DEFINE_ENUM(NFS4ERR_WRONGSEC);
+TRACE_DEFINE_ENUM(NFS4ERR_WRONG_CRED);
+TRACE_DEFINE_ENUM(NFS4ERR_WRONG_TYPE);
+TRACE_DEFINE_ENUM(NFS4ERR_XDEV);
+
+TRACE_DEFINE_ENUM(NFS4ERR_RESET_TO_MDS);
+TRACE_DEFINE_ENUM(NFS4ERR_RESET_TO_PNFS);
+
+#define show_nfsv4_errors(error) \
+	__print_symbolic(error, \
+		{ NFS4_OK, "OK" }, \
+		/* Mapped by nfs4_stat_to_errno() */ \
+		{ EPERM, "EPERM" }, \
+		{ ENOENT, "ENOENT" }, \
+		{ EIO, "EIO" }, \
+		{ ENXIO, "ENXIO" }, \
+		{ EACCES, "EACCES" }, \
+		{ EEXIST, "EEXIST" }, \
+		{ EXDEV, "EXDEV" }, \
+		{ ENOTDIR, "ENOTDIR" }, \
+		{ EISDIR, "EISDIR" }, \
+		{ EFBIG, "EFBIG" }, \
+		{ ENOSPC, "ENOSPC" }, \
+		{ EROFS, "EROFS" }, \
+		{ EMLINK, "EMLINK" }, \
+		{ ENAMETOOLONG, "ENAMETOOLONG" }, \
+		{ ENOTEMPTY, "ENOTEMPTY" }, \
+		{ EDQUOT, "EDQUOT" }, \
+		{ ESTALE, "ESTALE" }, \
+		{ EBADHANDLE, "EBADHANDLE" }, \
+		{ EBADCOOKIE, "EBADCOOKIE" }, \
+		{ ENOTSUPP, "ENOTSUPP" }, \
+		{ ETOOSMALL, "ETOOSMALL" }, \
+		{ EREMOTEIO, "EREMOTEIO" }, \
+		{ EBADTYPE, "EBADTYPE" }, \
+		{ EAGAIN, "EAGAIN" }, \
+		{ ELOOP, "ELOOP" }, \
+		{ EOPNOTSUPP, "EOPNOTSUPP" }, \
+		{ EDEADLK, "EDEADLK" }, \
+		/* RPC errors */ \
+		{ ENOMEM, "ENOMEM" }, \
+		{ EKEYEXPIRED, "EKEYEXPIRED" }, \
+		{ ETIMEDOUT, "ETIMEDOUT" }, \
+		{ ERESTARTSYS, "ERESTARTSYS" }, \
+		{ ECONNREFUSED, "ECONNREFUSED" }, \
+		{ ECONNRESET, "ECONNRESET" }, \
+		{ ENETUNREACH, "ENETUNREACH" }, \
+		{ EHOSTUNREACH, "EHOSTUNREACH" }, \
+		{ EHOSTDOWN, "EHOSTDOWN" }, \
+		{ EPIPE, "EPIPE" }, \
+		{ EPFNOSUPPORT, "EPFNOSUPPORT" }, \
+		{ EPROTONOSUPPORT, "EPROTONOSUPPORT" }, \
+		/* NFSv4 native errors */ \
+		{ NFS4ERR_ACCESS, "ACCESS" }, \
+		{ NFS4ERR_ATTRNOTSUPP, "ATTRNOTSUPP" }, \
+		{ NFS4ERR_ADMIN_REVOKED, "ADMIN_REVOKED" }, \
+		{ NFS4ERR_BACK_CHAN_BUSY, "BACK_CHAN_BUSY" }, \
+		{ NFS4ERR_BADCHAR, "BADCHAR" }, \
+		{ NFS4ERR_BADHANDLE, "BADHANDLE" }, \
+		{ NFS4ERR_BADIOMODE, "BADIOMODE" }, \
+		{ NFS4ERR_BADLAYOUT, "BADLAYOUT" }, \
+		{ NFS4ERR_BADLABEL, "BADLABEL" }, \
+		{ NFS4ERR_BADNAME, "BADNAME" }, \
+		{ NFS4ERR_BADOWNER, "BADOWNER" }, \
+		{ NFS4ERR_BADSESSION, "BADSESSION" }, \
+		{ NFS4ERR_BADSLOT, "BADSLOT" }, \
+		{ NFS4ERR_BADTYPE, "BADTYPE" }, \
+		{ NFS4ERR_BADXDR, "BADXDR" }, \
+		{ NFS4ERR_BAD_COOKIE, "BAD_COOKIE" }, \
+		{ NFS4ERR_BAD_HIGH_SLOT, "BAD_HIGH_SLOT" }, \
+		{ NFS4ERR_BAD_RANGE, "BAD_RANGE" }, \
+		{ NFS4ERR_BAD_SEQID, "BAD_SEQID" }, \
+		{ NFS4ERR_BAD_SESSION_DIGEST, "BAD_SESSION_DIGEST" }, \
+		{ NFS4ERR_BAD_STATEID, "BAD_STATEID" }, \
+		{ NFS4ERR_CB_PATH_DOWN, "CB_PATH_DOWN" }, \
+		{ NFS4ERR_CLID_INUSE, "CLID_INUSE" }, \
+		{ NFS4ERR_CLIENTID_BUSY, "CLIENTID_BUSY" }, \
+		{ NFS4ERR_COMPLETE_ALREADY, "COMPLETE_ALREADY" }, \
+		{ NFS4ERR_CONN_NOT_BOUND_TO_SESSION, \
+			"CONN_NOT_BOUND_TO_SESSION" }, \
+		{ NFS4ERR_DEADLOCK, "DEADLOCK" }, \
+		{ NFS4ERR_DEADSESSION, "DEAD_SESSION" }, \
+		{ NFS4ERR_DELAY, "DELAY" }, \
+		{ NFS4ERR_DELEG_ALREADY_WANTED, \
+			"DELEG_ALREADY_WANTED" }, \
+		{ NFS4ERR_DELEG_REVOKED, "DELEG_REVOKED" }, \
+		{ NFS4ERR_DENIED, "DENIED" }, \
+		{ NFS4ERR_DIRDELEG_UNAVAIL, "DIRDELEG_UNAVAIL" }, \
+		{ NFS4ERR_DQUOT, "DQUOT" }, \
+		{ NFS4ERR_ENCR_ALG_UNSUPP, "ENCR_ALG_UNSUPP" }, \
+		{ NFS4ERR_EXIST, "EXIST" }, \
+		{ NFS4ERR_EXPIRED, "EXPIRED" }, \
+		{ NFS4ERR_FBIG, "FBIG" }, \
+		{ NFS4ERR_FHEXPIRED, "FHEXPIRED" }, \
+		{ NFS4ERR_FILE_OPEN, "FILE_OPEN" }, \
+		{ NFS4ERR_GRACE, "GRACE" }, \
+		{ NFS4ERR_HASH_ALG_UNSUPP, "HASH_ALG_UNSUPP" }, \
+		{ NFS4ERR_INVAL, "INVAL" }, \
+		{ NFS4ERR_IO, "IO" }, \
+		{ NFS4ERR_ISDIR, "ISDIR" }, \
+		{ NFS4ERR_LAYOUTTRYLATER, "LAYOUTTRYLATER" }, \
+		{ NFS4ERR_LAYOUTUNAVAILABLE, "LAYOUTUNAVAILABLE" }, \
+		{ NFS4ERR_LEASE_MOVED, "LEASE_MOVED" }, \
+		{ NFS4ERR_LOCKED, "LOCKED" }, \
+		{ NFS4ERR_LOCKS_HELD, "LOCKS_HELD" }, \
+		{ NFS4ERR_LOCK_RANGE, "LOCK_RANGE" }, \
+		{ NFS4ERR_MINOR_VERS_MISMATCH, "MINOR_VERS_MISMATCH" }, \
+		{ NFS4ERR_MLINK, "MLINK" }, \
+		{ NFS4ERR_MOVED, "MOVED" }, \
+		{ NFS4ERR_NAMETOOLONG, "NAMETOOLONG" }, \
+		{ NFS4ERR_NOENT, "NOENT" }, \
+		{ NFS4ERR_NOFILEHANDLE, "NOFILEHANDLE" }, \
+		{ NFS4ERR_NOMATCHING_LAYOUT, "NOMATCHING_LAYOUT" }, \
+		{ NFS4ERR_NOSPC, "NOSPC" }, \
+		{ NFS4ERR_NOTDIR, "NOTDIR" }, \
+		{ NFS4ERR_NOTEMPTY, "NOTEMPTY" }, \
+		{ NFS4ERR_NOTSUPP, "NOTSUPP" }, \
+		{ NFS4ERR_NOT_ONLY_OP, "NOT_ONLY_OP" }, \
+		{ NFS4ERR_NOT_SAME, "NOT_SAME" }, \
+		{ NFS4ERR_NO_GRACE, "NO_GRACE" }, \
+		{ NFS4ERR_NXIO, "NXIO" }, \
+		{ NFS4ERR_OLD_STATEID, "OLD_STATEID" }, \
+		{ NFS4ERR_OPENMODE, "OPENMODE" }, \
+		{ NFS4ERR_OP_ILLEGAL, "OP_ILLEGAL" }, \
+		{ NFS4ERR_OP_NOT_IN_SESSION, "OP_NOT_IN_SESSION" }, \
+		{ NFS4ERR_PERM, "PERM" }, \
+		{ NFS4ERR_PNFS_IO_HOLE, "PNFS_IO_HOLE" }, \
+		{ NFS4ERR_PNFS_NO_LAYOUT, "PNFS_NO_LAYOUT" }, \
+		{ NFS4ERR_RECALLCONFLICT, "RECALLCONFLICT" }, \
+		{ NFS4ERR_RECLAIM_BAD, "RECLAIM_BAD" }, \
+		{ NFS4ERR_RECLAIM_CONFLICT, "RECLAIM_CONFLICT" }, \
+		{ NFS4ERR_REJECT_DELEG, "REJECT_DELEG" }, \
+		{ NFS4ERR_REP_TOO_BIG, "REP_TOO_BIG" }, \
+		{ NFS4ERR_REP_TOO_BIG_TO_CACHE, \
+			"REP_TOO_BIG_TO_CACHE" }, \
+		{ NFS4ERR_REQ_TOO_BIG, "REQ_TOO_BIG" }, \
+		{ NFS4ERR_RESOURCE, "RESOURCE" }, \
+		{ NFS4ERR_RESTOREFH, "RESTOREFH" }, \
+		{ NFS4ERR_RETRY_UNCACHED_REP, "RETRY_UNCACHED_REP" }, \
+		{ NFS4ERR_RETURNCONFLICT, "RETURNCONFLICT" }, \
+		{ NFS4ERR_ROFS, "ROFS" }, \
+		{ NFS4ERR_SAME, "SAME" }, \
+		{ NFS4ERR_SHARE_DENIED, "SHARE_DENIED" }, \
+		{ NFS4ERR_SEQUENCE_POS, "SEQUENCE_POS" }, \
+		{ NFS4ERR_SEQ_FALSE_RETRY, "SEQ_FALSE_RETRY" }, \
+		{ NFS4ERR_SEQ_MISORDERED, "SEQ_MISORDERED" }, \
+		{ NFS4ERR_SERVERFAULT, "SERVERFAULT" }, \
+		{ NFS4ERR_STALE, "STALE" }, \
+		{ NFS4ERR_STALE_CLIENTID, "STALE_CLIENTID" }, \
+		{ NFS4ERR_STALE_STATEID, "STALE_STATEID" }, \
+		{ NFS4ERR_SYMLINK, "SYMLINK" }, \
+		{ NFS4ERR_TOOSMALL, "TOOSMALL" }, \
+		{ NFS4ERR_TOO_MANY_OPS, "TOO_MANY_OPS" }, \
+		{ NFS4ERR_UNKNOWN_LAYOUTTYPE, "UNKNOWN_LAYOUTTYPE" }, \
+		{ NFS4ERR_UNSAFE_COMPOUND, "UNSAFE_COMPOUND" }, \
+		{ NFS4ERR_WRONGSEC, "WRONGSEC" }, \
+		{ NFS4ERR_WRONG_CRED, "WRONG_CRED" }, \
+		{ NFS4ERR_WRONG_TYPE, "WRONG_TYPE" }, \
+		{ NFS4ERR_XDEV, "XDEV" }, \
+		/* ***** Internal to Linux NFS client ***** */ \
+		{ NFS4ERR_RESET_TO_MDS, "RESET_TO_MDS" }, \
+		{ NFS4ERR_RESET_TO_PNFS, "RESET_TO_PNFS" })
+
+#define show_open_flags(flags) \
+	__print_flags(flags, "|", \
+		{ O_CREAT, "O_CREAT" }, \
+		{ O_EXCL, "O_EXCL" }, \
+		{ O_TRUNC, "O_TRUNC" }, \
+		{ O_DIRECT, "O_DIRECT" })
+
+#define show_fmode_flags(mode) \
+	__print_flags(mode, "|", \
+		{ ((__force unsigned long)FMODE_READ), "READ" }, \
+		{ ((__force unsigned long)FMODE_WRITE), "WRITE" }, \
+		{ ((__force unsigned long)FMODE_EXEC), "EXEC" })
+
+#define show_nfs_fattr_flags(valid) \
+	__print_flags((unsigned long)valid, "|", \
+		{ NFS_ATTR_FATTR_TYPE, "TYPE" }, \
+		{ NFS_ATTR_FATTR_MODE, "MODE" }, \
+		{ NFS_ATTR_FATTR_NLINK, "NLINK" }, \
+		{ NFS_ATTR_FATTR_OWNER, "OWNER" }, \
+		{ NFS_ATTR_FATTR_GROUP, "GROUP" }, \
+		{ NFS_ATTR_FATTR_RDEV, "RDEV" }, \
+		{ NFS_ATTR_FATTR_SIZE, "SIZE" }, \
+		{ NFS_ATTR_FATTR_FSID, "FSID" }, \
+		{ NFS_ATTR_FATTR_FILEID, "FILEID" }, \
+		{ NFS_ATTR_FATTR_ATIME, "ATIME" }, \
+		{ NFS_ATTR_FATTR_MTIME, "MTIME" }, \
+		{ NFS_ATTR_FATTR_CTIME, "CTIME" }, \
+		{ NFS_ATTR_FATTR_CHANGE, "CHANGE" }, \
+		{ NFS_ATTR_FATTR_OWNER_NAME, "OWNER_NAME" }, \
+		{ NFS_ATTR_FATTR_GROUP_NAME, "GROUP_NAME" })
+
+DECLARE_EVENT_CLASS(nfs4_clientid_event,
+		TP_PROTO(
+			const struct nfs_client *clp,
+			int error
+		),
+
+		TP_ARGS(clp, error),
+
+		TP_STRUCT__entry(
+			__string(dstaddr, clp->cl_hostname)
+			__field(unsigned long, error)
+		),
+
+		TP_fast_assign(
+			__entry->error = error < 0 ? -error : 0;
+			__assign_str(dstaddr, clp->cl_hostname);
+		),
+
+		TP_printk(
+			"error=%ld (%s) dstaddr=%s",
+			-__entry->error,
+			show_nfsv4_errors(__entry->error),
+			__get_str(dstaddr)
+		)
+);
+#define DEFINE_NFS4_CLIENTID_EVENT(name) \
+	DEFINE_EVENT(nfs4_clientid_event, name,	 \
+			TP_PROTO( \
+				const struct nfs_client *clp, \
+				int error \
+			), \
+			TP_ARGS(clp, error))
+DEFINE_NFS4_CLIENTID_EVENT(nfs4_setclientid);
+DEFINE_NFS4_CLIENTID_EVENT(nfs4_setclientid_confirm);
+DEFINE_NFS4_CLIENTID_EVENT(nfs4_renew);
+DEFINE_NFS4_CLIENTID_EVENT(nfs4_renew_async);
+#ifdef CONFIG_NFS_V4_1
+DEFINE_NFS4_CLIENTID_EVENT(nfs4_exchange_id);
+DEFINE_NFS4_CLIENTID_EVENT(nfs4_create_session);
+DEFINE_NFS4_CLIENTID_EVENT(nfs4_destroy_session);
+DEFINE_NFS4_CLIENTID_EVENT(nfs4_destroy_clientid);
+DEFINE_NFS4_CLIENTID_EVENT(nfs4_bind_conn_to_session);
+DEFINE_NFS4_CLIENTID_EVENT(nfs4_sequence);
+DEFINE_NFS4_CLIENTID_EVENT(nfs4_reclaim_complete);
+
+#define show_nfs4_sequence_status_flags(status) \
+	__print_flags((unsigned long)status, "|", \
+		{ SEQ4_STATUS_CB_PATH_DOWN, "CB_PATH_DOWN" }, \
+		{ SEQ4_STATUS_CB_GSS_CONTEXTS_EXPIRING, \
+			"CB_GSS_CONTEXTS_EXPIRING" }, \
+		{ SEQ4_STATUS_CB_GSS_CONTEXTS_EXPIRED, \
+			"CB_GSS_CONTEXTS_EXPIRED" }, \
+		{ SEQ4_STATUS_EXPIRED_ALL_STATE_REVOKED, \
+			"EXPIRED_ALL_STATE_REVOKED" }, \
+		{ SEQ4_STATUS_EXPIRED_SOME_STATE_REVOKED, \
+			"EXPIRED_SOME_STATE_REVOKED" }, \
+		{ SEQ4_STATUS_ADMIN_STATE_REVOKED, \
+			"ADMIN_STATE_REVOKED" }, \
+		{ SEQ4_STATUS_RECALLABLE_STATE_REVOKED,	 \
+			"RECALLABLE_STATE_REVOKED" }, \
+		{ SEQ4_STATUS_LEASE_MOVED, "LEASE_MOVED" }, \
+		{ SEQ4_STATUS_RESTART_RECLAIM_NEEDED, \
+			"RESTART_RECLAIM_NEEDED" }, \
+		{ SEQ4_STATUS_CB_PATH_DOWN_SESSION, \
+			"CB_PATH_DOWN_SESSION" }, \
+		{ SEQ4_STATUS_BACKCHANNEL_FAULT, \
+			"BACKCHANNEL_FAULT" })
+
+TRACE_EVENT(nfs4_sequence_done,
+		TP_PROTO(
+			const struct nfs4_session *session,
+			const struct nfs4_sequence_res *res
+		),
+		TP_ARGS(session, res),
+
+		TP_STRUCT__entry(
+			__field(unsigned int, session)
+			__field(unsigned int, slot_nr)
+			__field(unsigned int, seq_nr)
+			__field(unsigned int, highest_slotid)
+			__field(unsigned int, target_highest_slotid)
+			__field(unsigned int, status_flags)
+			__field(unsigned long, error)
+		),
+
+		TP_fast_assign(
+			const struct nfs4_slot *sr_slot = res->sr_slot;
+			__entry->session = nfs_session_id_hash(&session->sess_id);
+			__entry->slot_nr = sr_slot->slot_nr;
+			__entry->seq_nr = sr_slot->seq_nr;
+			__entry->highest_slotid = res->sr_highest_slotid;
+			__entry->target_highest_slotid =
+					res->sr_target_highest_slotid;
+			__entry->status_flags = res->sr_status_flags;
+			__entry->error = res->sr_status < 0 ?
+					-res->sr_status : 0;
+		),
+		TP_printk(
+			"error=%ld (%s) session=0x%08x slot_nr=%u seq_nr=%u "
+			"highest_slotid=%u target_highest_slotid=%u "
+			"status_flags=%u (%s)",
+			-__entry->error,
+			show_nfsv4_errors(__entry->error),
+			__entry->session,
+			__entry->slot_nr,
+			__entry->seq_nr,
+			__entry->highest_slotid,
+			__entry->target_highest_slotid,
+			__entry->status_flags,
+			show_nfs4_sequence_status_flags(__entry->status_flags)
+		)
+);
+
+struct cb_sequenceargs;
+struct cb_sequenceres;
+
+TRACE_EVENT(nfs4_cb_sequence,
+		TP_PROTO(
+			const struct cb_sequenceargs *args,
+			const struct cb_sequenceres *res,
+			__be32 status
+		),
+		TP_ARGS(args, res, status),
+
+		TP_STRUCT__entry(
+			__field(unsigned int, session)
+			__field(unsigned int, slot_nr)
+			__field(unsigned int, seq_nr)
+			__field(unsigned int, highest_slotid)
+			__field(unsigned int, cachethis)
+			__field(unsigned long, error)
+		),
+
+		TP_fast_assign(
+			__entry->session = nfs_session_id_hash(&args->csa_sessionid);
+			__entry->slot_nr = args->csa_slotid;
+			__entry->seq_nr = args->csa_sequenceid;
+			__entry->highest_slotid = args->csa_highestslotid;
+			__entry->cachethis = args->csa_cachethis;
+			__entry->error = be32_to_cpu(status);
+		),
+
+		TP_printk(
+			"error=%ld (%s) session=0x%08x slot_nr=%u seq_nr=%u "
+			"highest_slotid=%u",
+			-__entry->error,
+			show_nfsv4_errors(__entry->error),
+			__entry->session,
+			__entry->slot_nr,
+			__entry->seq_nr,
+			__entry->highest_slotid
+		)
+);
+
+TRACE_EVENT(nfs4_cb_seqid_err,
+		TP_PROTO(
+			const struct cb_sequenceargs *args,
+			__be32 status
+		),
+		TP_ARGS(args, status),
+
+		TP_STRUCT__entry(
+			__field(unsigned int, session)
+			__field(unsigned int, slot_nr)
+			__field(unsigned int, seq_nr)
+			__field(unsigned int, highest_slotid)
+			__field(unsigned int, cachethis)
+			__field(unsigned long, error)
+		),
+
+		TP_fast_assign(
+			__entry->session = nfs_session_id_hash(&args->csa_sessionid);
+			__entry->slot_nr = args->csa_slotid;
+			__entry->seq_nr = args->csa_sequenceid;
+			__entry->highest_slotid = args->csa_highestslotid;
+			__entry->cachethis = args->csa_cachethis;
+			__entry->error = be32_to_cpu(status);
+		),
+
+		TP_printk(
+			"error=%ld (%s) session=0x%08x slot_nr=%u seq_nr=%u "
+			"highest_slotid=%u",
+			-__entry->error,
+			show_nfsv4_errors(__entry->error),
+			__entry->session,
+			__entry->slot_nr,
+			__entry->seq_nr,
+			__entry->highest_slotid
+		)
+);
+
+#endif /* CONFIG_NFS_V4_1 */
+
+TRACE_EVENT(nfs4_setup_sequence,
+		TP_PROTO(
+			const struct nfs4_session *session,
+			const struct nfs4_sequence_args *args
+		),
+		TP_ARGS(session, args),
+
+		TP_STRUCT__entry(
+			__field(unsigned int, session)
+			__field(unsigned int, slot_nr)
+			__field(unsigned int, seq_nr)
+			__field(unsigned int, highest_used_slotid)
+		),
+
+		TP_fast_assign(
+			const struct nfs4_slot *sa_slot = args->sa_slot;
+			__entry->session = session ? nfs_session_id_hash(&session->sess_id) : 0;
+			__entry->slot_nr = sa_slot->slot_nr;
+			__entry->seq_nr = sa_slot->seq_nr;
+			__entry->highest_used_slotid =
+					sa_slot->table->highest_used_slotid;
+		),
+		TP_printk(
+			"session=0x%08x slot_nr=%u seq_nr=%u "
+			"highest_used_slotid=%u",
+			__entry->session,
+			__entry->slot_nr,
+			__entry->seq_nr,
+			__entry->highest_used_slotid
+		)
+);
+
+TRACE_DEFINE_ENUM(NFS4CLNT_MANAGER_RUNNING);
+TRACE_DEFINE_ENUM(NFS4CLNT_CHECK_LEASE);
+TRACE_DEFINE_ENUM(NFS4CLNT_LEASE_EXPIRED);
+TRACE_DEFINE_ENUM(NFS4CLNT_RECLAIM_REBOOT);
+TRACE_DEFINE_ENUM(NFS4CLNT_RECLAIM_NOGRACE);
+TRACE_DEFINE_ENUM(NFS4CLNT_DELEGRETURN);
+TRACE_DEFINE_ENUM(NFS4CLNT_SESSION_RESET);
+TRACE_DEFINE_ENUM(NFS4CLNT_LEASE_CONFIRM);
+TRACE_DEFINE_ENUM(NFS4CLNT_SERVER_SCOPE_MISMATCH);
+TRACE_DEFINE_ENUM(NFS4CLNT_PURGE_STATE);
+TRACE_DEFINE_ENUM(NFS4CLNT_BIND_CONN_TO_SESSION);
+TRACE_DEFINE_ENUM(NFS4CLNT_MOVED);
+TRACE_DEFINE_ENUM(NFS4CLNT_LEASE_MOVED);
+TRACE_DEFINE_ENUM(NFS4CLNT_DELEGATION_EXPIRED);
+TRACE_DEFINE_ENUM(NFS4CLNT_RUN_MANAGER);
+TRACE_DEFINE_ENUM(NFS4CLNT_MANAGER_AVAILABLE);
+TRACE_DEFINE_ENUM(NFS4CLNT_RECALL_RUNNING);
+TRACE_DEFINE_ENUM(NFS4CLNT_RECALL_ANY_LAYOUT_READ);
+TRACE_DEFINE_ENUM(NFS4CLNT_RECALL_ANY_LAYOUT_RW);
+TRACE_DEFINE_ENUM(NFS4CLNT_DELEGRETURN_DELAYED);
+
+#define show_nfs4_clp_state(state) \
+	__print_flags(state, "|", \
+	{ BIT(NFS4CLNT_MANAGER_RUNNING),	"MANAGER_RUNNING" }, \
+	{ BIT(NFS4CLNT_CHECK_LEASE),		"CHECK_LEASE" }, \
+	{ BIT(NFS4CLNT_LEASE_EXPIRED),	"LEASE_EXPIRED" }, \
+	{ BIT(NFS4CLNT_RECLAIM_REBOOT),	"RECLAIM_REBOOT" }, \
+	{ BIT(NFS4CLNT_RECLAIM_NOGRACE),	"RECLAIM_NOGRACE" }, \
+	{ BIT(NFS4CLNT_DELEGRETURN),		"DELEGRETURN" }, \
+	{ BIT(NFS4CLNT_SESSION_RESET),	"SESSION_RESET" }, \
+	{ BIT(NFS4CLNT_LEASE_CONFIRM),	"LEASE_CONFIRM" }, \
+	{ BIT(NFS4CLNT_SERVER_SCOPE_MISMATCH),	"SERVER_SCOPE_MISMATCH" }, \
+	{ BIT(NFS4CLNT_PURGE_STATE),		"PURGE_STATE" }, \
+	{ BIT(NFS4CLNT_BIND_CONN_TO_SESSION),	"BIND_CONN_TO_SESSION" }, \
+	{ BIT(NFS4CLNT_MOVED),		"MOVED" }, \
+	{ BIT(NFS4CLNT_LEASE_MOVED),		"LEASE_MOVED" }, \
+	{ BIT(NFS4CLNT_DELEGATION_EXPIRED),	"DELEGATION_EXPIRED" }, \
+	{ BIT(NFS4CLNT_RUN_MANAGER),		"RUN_MANAGER" }, \
+	{ BIT(NFS4CLNT_MANAGER_AVAILABLE), "MANAGER_AVAILABLE" }, \
+	{ BIT(NFS4CLNT_RECALL_RUNNING),	"RECALL_RUNNING" }, \
+	{ BIT(NFS4CLNT_RECALL_ANY_LAYOUT_READ), "RECALL_ANY_LAYOUT_READ" }, \
+	{ BIT(NFS4CLNT_RECALL_ANY_LAYOUT_RW), "RECALL_ANY_LAYOUT_RW" }, \
+	{ BIT(NFS4CLNT_DELEGRETURN_DELAYED), "DELERETURN_DELAYED" })
+
+TRACE_EVENT(nfs4_state_mgr,
+		TP_PROTO(
+			const struct nfs_client *clp
+		),
+
+		TP_ARGS(clp),
+
+		TP_STRUCT__entry(
+			__field(unsigned long, state)
+			__string(hostname, clp->cl_hostname)
+		),
+
+		TP_fast_assign(
+			__entry->state = clp->cl_state;
+			__assign_str(hostname, clp->cl_hostname)
+		),
+
+		TP_printk(
+			"hostname=%s clp state=%s", __get_str(hostname),
+			show_nfs4_clp_state(__entry->state)
+		)
+)
+
+TRACE_EVENT(nfs4_state_mgr_failed,
+		TP_PROTO(
+			const struct nfs_client *clp,
+			const char *section,
+			int status
+		),
+
+		TP_ARGS(clp, section, status),
+
+		TP_STRUCT__entry(
+			__field(unsigned long, error)
+			__field(unsigned long, state)
+			__string(hostname, clp->cl_hostname)
+			__string(section, section)
+		),
+
+		TP_fast_assign(
+			__entry->error = status < 0 ? -status : 0;
+			__entry->state = clp->cl_state;
+			__assign_str(hostname, clp->cl_hostname);
+			__assign_str(section, section);
+		),
+
+		TP_printk(
+			"hostname=%s clp state=%s error=%ld (%s) section=%s",
+			__get_str(hostname),
+			show_nfs4_clp_state(__entry->state), -__entry->error,
+			show_nfsv4_errors(__entry->error), __get_str(section)
+
+		)
+)
+
+TRACE_EVENT(nfs4_xdr_status,
+		TP_PROTO(
+			const struct xdr_stream *xdr,
+			u32 op,
+			u32 error
+		),
+
+		TP_ARGS(xdr, op, error),
+
+		TP_STRUCT__entry(
+			__field(unsigned int, task_id)
+			__field(unsigned int, client_id)
+			__field(u32, xid)
+			__field(u32, op)
+			__field(unsigned long, error)
+		),
+
+		TP_fast_assign(
+			const struct rpc_rqst *rqstp = xdr->rqst;
+			const struct rpc_task *task = rqstp->rq_task;
+
+			__entry->task_id = task->tk_pid;
+			__entry->client_id = task->tk_client->cl_clid;
+			__entry->xid = be32_to_cpu(rqstp->rq_xid);
+			__entry->op = op;
+			__entry->error = error;
+		),
+
+		TP_printk(
+			"task:%u@%d xid=0x%08x error=%ld (%s) operation=%u",
+			__entry->task_id, __entry->client_id, __entry->xid,
+			-__entry->error, show_nfsv4_errors(__entry->error),
+			__entry->op
+		)
+);
+
+DECLARE_EVENT_CLASS(nfs4_cb_error_class,
+		TP_PROTO(
+			__be32 xid,
+			u32 cb_ident
+		),
+
+		TP_ARGS(xid, cb_ident),
+
+		TP_STRUCT__entry(
+			__field(u32, xid)
+			__field(u32, cbident)
+		),
+
+		TP_fast_assign(
+			__entry->xid = be32_to_cpu(xid);
+			__entry->cbident = cb_ident;
+		),
+
+		TP_printk(
+			"xid=0x%08x cb_ident=0x%08x",
+			__entry->xid, __entry->cbident
+		)
+);
+
+#define DEFINE_CB_ERROR_EVENT(name) \
+	DEFINE_EVENT(nfs4_cb_error_class, nfs_cb_##name, \
+			TP_PROTO( \
+				__be32 xid, \
+				u32 cb_ident \
+			), \
+			TP_ARGS(xid, cb_ident))
+
+DEFINE_CB_ERROR_EVENT(no_clp);
+DEFINE_CB_ERROR_EVENT(badprinc);
+
+DECLARE_EVENT_CLASS(nfs4_open_event,
+		TP_PROTO(
+			const struct nfs_open_context *ctx,
+			int flags,
+			int error
+		),
+
+		TP_ARGS(ctx, flags, error),
+
+		TP_STRUCT__entry(
+			__field(unsigned long, error)
+			__field(unsigned int, flags)
+			__field(unsigned int, fmode)
+			__field(dev_t, dev)
+			__field(u32, fhandle)
+			__field(u64, fileid)
+			__field(u64, dir)
+			__string(name, ctx->dentry->d_name.name)
+			__field(int, stateid_seq)
+			__field(u32, stateid_hash)
+			__field(int, openstateid_seq)
+			__field(u32, openstateid_hash)
+		),
+
+		TP_fast_assign(
+			const struct nfs4_state *state = ctx->state;
+			const struct inode *inode = NULL;
+
+			__entry->error = -error;
+			__entry->flags = flags;
+			__entry->fmode = (__force unsigned int)ctx->mode;
+			__entry->dev = ctx->dentry->d_sb->s_dev;
+			if (!IS_ERR_OR_NULL(state)) {
+				inode = state->inode;
+				__entry->stateid_seq =
+					be32_to_cpu(state->stateid.seqid);
+				__entry->stateid_hash =
+					nfs_stateid_hash(&state->stateid);
+				__entry->openstateid_seq =
+					be32_to_cpu(state->open_stateid.seqid);
+				__entry->openstateid_hash =
+					nfs_stateid_hash(&state->open_stateid);
+			} else {
+				__entry->stateid_seq = 0;
+				__entry->stateid_hash = 0;
+				__entry->openstateid_seq = 0;
+				__entry->openstateid_hash = 0;
+			}
+			if (inode != NULL) {
+				__entry->fileid = NFS_FILEID(inode);
+				__entry->fhandle = nfs_fhandle_hash(NFS_FH(inode));
+			} else {
+				__entry->fileid = 0;
+				__entry->fhandle = 0;
+			}
+			__entry->dir = NFS_FILEID(d_inode(ctx->dentry->d_parent));
+			__assign_str(name, ctx->dentry->d_name.name);
+		),
+
+		TP_printk(
+			"error=%ld (%s) flags=%d (%s) fmode=%s "
+			"fileid=%02x:%02x:%llu fhandle=0x%08x "
+			"name=%02x:%02x:%llu/%s stateid=%d:0x%08x "
+			"openstateid=%d:0x%08x",
+			 -__entry->error,
+			 show_nfsv4_errors(__entry->error),
+			 __entry->flags,
+			 show_open_flags(__entry->flags),
+			 show_fmode_flags(__entry->fmode),
+			 MAJOR(__entry->dev), MINOR(__entry->dev),
+			 (unsigned long long)__entry->fileid,
+			 __entry->fhandle,
+			 MAJOR(__entry->dev), MINOR(__entry->dev),
+			 (unsigned long long)__entry->dir,
+			 __get_str(name),
+			 __entry->stateid_seq, __entry->stateid_hash,
+			 __entry->openstateid_seq, __entry->openstateid_hash
+		)
+);
+
+#define DEFINE_NFS4_OPEN_EVENT(name) \
+	DEFINE_EVENT(nfs4_open_event, name, \
+			TP_PROTO( \
+				const struct nfs_open_context *ctx, \
+				int flags, \
+				int error \
+			), \
+			TP_ARGS(ctx, flags, error))
+DEFINE_NFS4_OPEN_EVENT(nfs4_open_reclaim);
+DEFINE_NFS4_OPEN_EVENT(nfs4_open_expired);
+DEFINE_NFS4_OPEN_EVENT(nfs4_open_file);
+
+TRACE_EVENT(nfs4_cached_open,
+		TP_PROTO(
+			const struct nfs4_state *state
+		),
+		TP_ARGS(state),
+		TP_STRUCT__entry(
+			__field(dev_t, dev)
+			__field(u32, fhandle)
+			__field(u64, fileid)
+			__field(unsigned int, fmode)
+			__field(int, stateid_seq)
+			__field(u32, stateid_hash)
+		),
+
+		TP_fast_assign(
+			const struct inode *inode = state->inode;
+
+			__entry->dev = inode->i_sb->s_dev;
+			__entry->fileid = NFS_FILEID(inode);
+			__entry->fhandle = nfs_fhandle_hash(NFS_FH(inode));
+			__entry->fmode = (__force unsigned int)state->state;
+			__entry->stateid_seq =
+				be32_to_cpu(state->stateid.seqid);
+			__entry->stateid_hash =
+				nfs_stateid_hash(&state->stateid);
+		),
+
+		TP_printk(
+			"fmode=%s fileid=%02x:%02x:%llu "
+			"fhandle=0x%08x stateid=%d:0x%08x",
+			__entry->fmode ?  show_fmode_flags(__entry->fmode) :
+					  "closed",
+			MAJOR(__entry->dev), MINOR(__entry->dev),
+			(unsigned long long)__entry->fileid,
+			__entry->fhandle,
+			__entry->stateid_seq, __entry->stateid_hash
+		)
+);
+
+TRACE_EVENT(nfs4_close,
+		TP_PROTO(
+			const struct nfs4_state *state,
+			const struct nfs_closeargs *args,
+			const struct nfs_closeres *res,
+			int error
+		),
+
+		TP_ARGS(state, args, res, error),
+
+		TP_STRUCT__entry(
+			__field(dev_t, dev)
+			__field(u32, fhandle)
+			__field(u64, fileid)
+			__field(unsigned int, fmode)
+			__field(unsigned long, error)
+			__field(int, stateid_seq)
+			__field(u32, stateid_hash)
+		),
+
+		TP_fast_assign(
+			const struct inode *inode = state->inode;
+
+			__entry->dev = inode->i_sb->s_dev;
+			__entry->fileid = NFS_FILEID(inode);
+			__entry->fhandle = nfs_fhandle_hash(NFS_FH(inode));
+			__entry->fmode = (__force unsigned int)state->state;
+			__entry->error = error < 0 ? -error : 0;
+			__entry->stateid_seq =
+				be32_to_cpu(args->stateid.seqid);
+			__entry->stateid_hash =
+				nfs_stateid_hash(&args->stateid);
+		),
+
+		TP_printk(
+			"error=%ld (%s) fmode=%s fileid=%02x:%02x:%llu "
+			"fhandle=0x%08x openstateid=%d:0x%08x",
+			-__entry->error,
+			show_nfsv4_errors(__entry->error),
+			__entry->fmode ?  show_fmode_flags(__entry->fmode) :
+					  "closed",
+			MAJOR(__entry->dev), MINOR(__entry->dev),
+			(unsigned long long)__entry->fileid,
+			__entry->fhandle,
+			__entry->stateid_seq, __entry->stateid_hash
+		)
+);
+
+TRACE_DEFINE_ENUM(F_GETLK);
+TRACE_DEFINE_ENUM(F_SETLK);
+TRACE_DEFINE_ENUM(F_SETLKW);
+TRACE_DEFINE_ENUM(F_RDLCK);
+TRACE_DEFINE_ENUM(F_WRLCK);
+TRACE_DEFINE_ENUM(F_UNLCK);
+
+#define show_lock_cmd(type) \
+	__print_symbolic((int)type, \
+		{ F_GETLK, "GETLK" }, \
+		{ F_SETLK, "SETLK" }, \
+		{ F_SETLKW, "SETLKW" })
+#define show_lock_type(type) \
+	__print_symbolic((int)type, \
+		{ F_RDLCK, "RDLCK" }, \
+		{ F_WRLCK, "WRLCK" }, \
+		{ F_UNLCK, "UNLCK" })
+
+DECLARE_EVENT_CLASS(nfs4_lock_event,
+		TP_PROTO(
+			const struct file_lock *request,
+			const struct nfs4_state *state,
+			int cmd,
+			int error
+		),
+
+		TP_ARGS(request, state, cmd, error),
+
+		TP_STRUCT__entry(
+			__field(unsigned long, error)
+			__field(int, cmd)
+			__field(char, type)
+			__field(loff_t, start)
+			__field(loff_t, end)
+			__field(dev_t, dev)
+			__field(u32, fhandle)
+			__field(u64, fileid)
+			__field(int, stateid_seq)
+			__field(u32, stateid_hash)
+		),
+
+		TP_fast_assign(
+			const struct inode *inode = state->inode;
+
+			__entry->error = error < 0 ? -error : 0;
+			__entry->cmd = cmd;
+			__entry->type = request->fl_type;
+			__entry->start = request->fl_start;
+			__entry->end = request->fl_end;
+			__entry->dev = inode->i_sb->s_dev;
+			__entry->fileid = NFS_FILEID(inode);
+			__entry->fhandle = nfs_fhandle_hash(NFS_FH(inode));
+			__entry->stateid_seq =
+				be32_to_cpu(state->stateid.seqid);
+			__entry->stateid_hash =
+				nfs_stateid_hash(&state->stateid);
+		),
+
+		TP_printk(
+			"error=%ld (%s) cmd=%s:%s range=%lld:%lld "
+			"fileid=%02x:%02x:%llu fhandle=0x%08x "
+			"stateid=%d:0x%08x",
+			-__entry->error,
+			show_nfsv4_errors(__entry->error),
+			show_lock_cmd(__entry->cmd),
+			show_lock_type(__entry->type),
+			(long long)__entry->start,
+			(long long)__entry->end,
+			MAJOR(__entry->dev), MINOR(__entry->dev),
+			(unsigned long long)__entry->fileid,
+			__entry->fhandle,
+			__entry->stateid_seq, __entry->stateid_hash
+		)
+);
+
+#define DEFINE_NFS4_LOCK_EVENT(name) \
+	DEFINE_EVENT(nfs4_lock_event, name, \
+			TP_PROTO( \
+				const struct file_lock *request, \
+				const struct nfs4_state *state, \
+				int cmd, \
+				int error \
+			), \
+			TP_ARGS(request, state, cmd, error))
+DEFINE_NFS4_LOCK_EVENT(nfs4_get_lock);
+DEFINE_NFS4_LOCK_EVENT(nfs4_unlock);
+
+TRACE_EVENT(nfs4_set_lock,
+		TP_PROTO(
+			const struct file_lock *request,
+			const struct nfs4_state *state,
+			const nfs4_stateid *lockstateid,
+			int cmd,
+			int error
+		),
+
+		TP_ARGS(request, state, lockstateid, cmd, error),
+
+		TP_STRUCT__entry(
+			__field(unsigned long, error)
+			__field(int, cmd)
+			__field(char, type)
+			__field(loff_t, start)
+			__field(loff_t, end)
+			__field(dev_t, dev)
+			__field(u32, fhandle)
+			__field(u64, fileid)
+			__field(int, stateid_seq)
+			__field(u32, stateid_hash)
+			__field(int, lockstateid_seq)
+			__field(u32, lockstateid_hash)
+		),
+
+		TP_fast_assign(
+			const struct inode *inode = state->inode;
+
+			__entry->error = error < 0 ? -error : 0;
+			__entry->cmd = cmd;
+			__entry->type = request->fl_type;
+			__entry->start = request->fl_start;
+			__entry->end = request->fl_end;
+			__entry->dev = inode->i_sb->s_dev;
+			__entry->fileid = NFS_FILEID(inode);
+			__entry->fhandle = nfs_fhandle_hash(NFS_FH(inode));
+			__entry->stateid_seq =
+				be32_to_cpu(state->stateid.seqid);
+			__entry->stateid_hash =
+				nfs_stateid_hash(&state->stateid);
+			__entry->lockstateid_seq =
+				be32_to_cpu(lockstateid->seqid);
+			__entry->lockstateid_hash =
+				nfs_stateid_hash(lockstateid);
+		),
+
+		TP_printk(
+			"error=%ld (%s) cmd=%s:%s range=%lld:%lld "
+			"fileid=%02x:%02x:%llu fhandle=0x%08x "
+			"stateid=%d:0x%08x lockstateid=%d:0x%08x",
+			-__entry->error,
+			show_nfsv4_errors(__entry->error),
+			show_lock_cmd(__entry->cmd),
+			show_lock_type(__entry->type),
+			(long long)__entry->start,
+			(long long)__entry->end,
+			MAJOR(__entry->dev), MINOR(__entry->dev),
+			(unsigned long long)__entry->fileid,
+			__entry->fhandle,
+			__entry->stateid_seq, __entry->stateid_hash,
+			__entry->lockstateid_seq, __entry->lockstateid_hash
+		)
+);
+
+TRACE_DEFINE_ENUM(LK_STATE_IN_USE);
+TRACE_DEFINE_ENUM(NFS_DELEGATED_STATE);
+TRACE_DEFINE_ENUM(NFS_OPEN_STATE);
+TRACE_DEFINE_ENUM(NFS_O_RDONLY_STATE);
+TRACE_DEFINE_ENUM(NFS_O_WRONLY_STATE);
+TRACE_DEFINE_ENUM(NFS_O_RDWR_STATE);
+TRACE_DEFINE_ENUM(NFS_STATE_RECLAIM_REBOOT);
+TRACE_DEFINE_ENUM(NFS_STATE_RECLAIM_NOGRACE);
+TRACE_DEFINE_ENUM(NFS_STATE_POSIX_LOCKS);
+TRACE_DEFINE_ENUM(NFS_STATE_RECOVERY_FAILED);
+TRACE_DEFINE_ENUM(NFS_STATE_MAY_NOTIFY_LOCK);
+TRACE_DEFINE_ENUM(NFS_STATE_CHANGE_WAIT);
+TRACE_DEFINE_ENUM(NFS_CLNT_DST_SSC_COPY_STATE);
+TRACE_DEFINE_ENUM(NFS_CLNT_SRC_SSC_COPY_STATE);
+TRACE_DEFINE_ENUM(NFS_SRV_SSC_COPY_STATE);
+
+#define show_nfs4_state_flags(flags) \
+	__print_flags(flags, "|", \
+		{ LK_STATE_IN_USE,		"IN_USE" }, \
+		{ NFS_DELEGATED_STATE,		"DELEGATED" }, \
+		{ NFS_OPEN_STATE,		"OPEN" }, \
+		{ NFS_O_RDONLY_STATE,		"O_RDONLY" }, \
+		{ NFS_O_WRONLY_STATE,		"O_WRONLY" }, \
+		{ NFS_O_RDWR_STATE,		"O_RDWR" }, \
+		{ NFS_STATE_RECLAIM_REBOOT,	"RECLAIM_REBOOT" }, \
+		{ NFS_STATE_RECLAIM_NOGRACE,	"RECLAIM_NOGRACE" }, \
+		{ NFS_STATE_POSIX_LOCKS,	"POSIX_LOCKS" }, \
+		{ NFS_STATE_RECOVERY_FAILED,	"RECOVERY_FAILED" }, \
+		{ NFS_STATE_MAY_NOTIFY_LOCK,	"MAY_NOTIFY_LOCK" }, \
+		{ NFS_STATE_CHANGE_WAIT,	"CHANGE_WAIT" }, \
+		{ NFS_CLNT_DST_SSC_COPY_STATE,	"CLNT_DST_SSC_COPY" }, \
+		{ NFS_CLNT_SRC_SSC_COPY_STATE,	"CLNT_SRC_SSC_COPY" }, \
+		{ NFS_SRV_SSC_COPY_STATE,	"SRV_SSC_COPY" })
+
+#define show_nfs4_lock_flags(flags) \
+	__print_flags(flags, "|", \
+		{ BIT(NFS_LOCK_INITIALIZED),	"INITIALIZED" }, \
+		{ BIT(NFS_LOCK_LOST),		"LOST" })
+
+TRACE_EVENT(nfs4_state_lock_reclaim,
+		TP_PROTO(
+			const struct nfs4_state *state,
+			const struct nfs4_lock_state *lock
+		),
+
+		TP_ARGS(state, lock),
+
+		TP_STRUCT__entry(
+			__field(dev_t, dev)
+			__field(u32, fhandle)
+			__field(u64, fileid)
+			__field(unsigned long, state_flags)
+			__field(unsigned long, lock_flags)
+			__field(int, stateid_seq)
+			__field(u32, stateid_hash)
+		),
+
+		TP_fast_assign(
+			const struct inode *inode = state->inode;
+
+			__entry->dev = inode->i_sb->s_dev;
+			__entry->fileid = NFS_FILEID(inode);
+			__entry->fhandle = nfs_fhandle_hash(NFS_FH(inode));
+			__entry->state_flags = state->flags;
+			__entry->lock_flags = lock->ls_flags;
+			__entry->stateid_seq =
+				be32_to_cpu(state->stateid.seqid);
+			__entry->stateid_hash =
+				nfs_stateid_hash(&state->stateid);
+		),
+
+		TP_printk(
+			"fileid=%02x:%02x:%llu fhandle=0x%08x "
+			"stateid=%d:0x%08x state_flags=%s lock_flags=%s",
+			MAJOR(__entry->dev), MINOR(__entry->dev),
+			(unsigned long long)__entry->fileid, __entry->fhandle,
+			__entry->stateid_seq, __entry->stateid_hash,
+			show_nfs4_state_flags(__entry->state_flags),
+			show_nfs4_lock_flags(__entry->lock_flags)
+		)
+)
+
+DECLARE_EVENT_CLASS(nfs4_set_delegation_event,
+		TP_PROTO(
+			const struct inode *inode,
+			fmode_t fmode
+		),
+
+		TP_ARGS(inode, fmode),
+
+		TP_STRUCT__entry(
+			__field(dev_t, dev)
+			__field(u32, fhandle)
+			__field(u64, fileid)
+			__field(unsigned int, fmode)
+		),
+
+		TP_fast_assign(
+			__entry->dev = inode->i_sb->s_dev;
+			__entry->fileid = NFS_FILEID(inode);
+			__entry->fhandle = nfs_fhandle_hash(NFS_FH(inode));
+			__entry->fmode = (__force unsigned int)fmode;
+		),
+
+		TP_printk(
+			"fmode=%s fileid=%02x:%02x:%llu fhandle=0x%08x",
+			show_fmode_flags(__entry->fmode),
+			MAJOR(__entry->dev), MINOR(__entry->dev),
+			(unsigned long long)__entry->fileid,
+			__entry->fhandle
+		)
+);
+#define DEFINE_NFS4_SET_DELEGATION_EVENT(name) \
+	DEFINE_EVENT(nfs4_set_delegation_event, name, \
+			TP_PROTO( \
+				const struct inode *inode, \
+				fmode_t fmode \
+			), \
+			TP_ARGS(inode, fmode))
+DEFINE_NFS4_SET_DELEGATION_EVENT(nfs4_set_delegation);
+DEFINE_NFS4_SET_DELEGATION_EVENT(nfs4_reclaim_delegation);
+
+TRACE_EVENT(nfs4_delegreturn_exit,
+		TP_PROTO(
+			const struct nfs4_delegreturnargs *args,
+			const struct nfs4_delegreturnres *res,
+			int error
+		),
+
+		TP_ARGS(args, res, error),
+
+		TP_STRUCT__entry(
+			__field(dev_t, dev)
+			__field(u32, fhandle)
+			__field(unsigned long, error)
+			__field(int, stateid_seq)
+			__field(u32, stateid_hash)
+		),
+
+		TP_fast_assign(
+			__entry->dev = res->server->s_dev;
+			__entry->fhandle = nfs_fhandle_hash(args->fhandle);
+			__entry->error = error < 0 ? -error : 0;
+			__entry->stateid_seq =
+				be32_to_cpu(args->stateid->seqid);
+			__entry->stateid_hash =
+				nfs_stateid_hash(args->stateid);
+		),
+
+		TP_printk(
+			"error=%ld (%s) dev=%02x:%02x fhandle=0x%08x "
+			"stateid=%d:0x%08x",
+			-__entry->error,
+			show_nfsv4_errors(__entry->error),
+			MAJOR(__entry->dev), MINOR(__entry->dev),
+			__entry->fhandle,
+			__entry->stateid_seq, __entry->stateid_hash
+		)
+);
+
+#ifdef CONFIG_NFS_V4_1
+DECLARE_EVENT_CLASS(nfs4_test_stateid_event,
+		TP_PROTO(
+			const struct nfs4_state *state,
+			const struct nfs4_lock_state *lsp,
+			int error
+		),
+
+		TP_ARGS(state, lsp, error),
+
+		TP_STRUCT__entry(
+			__field(unsigned long, error)
+			__field(dev_t, dev)
+			__field(u32, fhandle)
+			__field(u64, fileid)
+			__field(int, stateid_seq)
+			__field(u32, stateid_hash)
+		),
+
+		TP_fast_assign(
+			const struct inode *inode = state->inode;
+
+			__entry->error = error < 0 ? -error : 0;
+			__entry->dev = inode->i_sb->s_dev;
+			__entry->fileid = NFS_FILEID(inode);
+			__entry->fhandle = nfs_fhandle_hash(NFS_FH(inode));
+			__entry->stateid_seq =
+				be32_to_cpu(state->stateid.seqid);
+			__entry->stateid_hash =
+				nfs_stateid_hash(&state->stateid);
+		),
+
+		TP_printk(
+			"error=%ld (%s) fileid=%02x:%02x:%llu fhandle=0x%08x "
+			"stateid=%d:0x%08x",
+			-__entry->error,
+			show_nfsv4_errors(__entry->error),
+			MAJOR(__entry->dev), MINOR(__entry->dev),
+			(unsigned long long)__entry->fileid,
+			__entry->fhandle,
+			__entry->stateid_seq, __entry->stateid_hash
+		)
+);
+
+#define DEFINE_NFS4_TEST_STATEID_EVENT(name) \
+	DEFINE_EVENT(nfs4_test_stateid_event, name, \
+			TP_PROTO( \
+				const struct nfs4_state *state, \
+				const struct nfs4_lock_state *lsp, \
+				int error \
+			), \
+			TP_ARGS(state, lsp, error))
+DEFINE_NFS4_TEST_STATEID_EVENT(nfs4_test_delegation_stateid);
+DEFINE_NFS4_TEST_STATEID_EVENT(nfs4_test_open_stateid);
+DEFINE_NFS4_TEST_STATEID_EVENT(nfs4_test_lock_stateid);
+#endif /* CONFIG_NFS_V4_1 */
+
+DECLARE_EVENT_CLASS(nfs4_lookup_event,
+		TP_PROTO(
+			const struct inode *dir,
+			const struct qstr *name,
+			int error
+		),
+
+		TP_ARGS(dir, name, error),
+
+		TP_STRUCT__entry(
+			__field(dev_t, dev)
+			__field(unsigned long, error)
+			__field(u64, dir)
+			__string(name, name->name)
+		),
+
+		TP_fast_assign(
+			__entry->dev = dir->i_sb->s_dev;
+			__entry->dir = NFS_FILEID(dir);
+			__entry->error = -error;
+			__assign_str(name, name->name);
+		),
+
+		TP_printk(
+			"error=%ld (%s) name=%02x:%02x:%llu/%s",
+			-__entry->error,
+			show_nfsv4_errors(__entry->error),
+			MAJOR(__entry->dev), MINOR(__entry->dev),
+			(unsigned long long)__entry->dir,
+			__get_str(name)
+		)
+);
+
+#define DEFINE_NFS4_LOOKUP_EVENT(name) \
+	DEFINE_EVENT(nfs4_lookup_event, name, \
+			TP_PROTO( \
+				const struct inode *dir, \
+				const struct qstr *name, \
+				int error \
+			), \
+			TP_ARGS(dir, name, error))
+
+DEFINE_NFS4_LOOKUP_EVENT(nfs4_lookup);
+DEFINE_NFS4_LOOKUP_EVENT(nfs4_symlink);
+DEFINE_NFS4_LOOKUP_EVENT(nfs4_mkdir);
+DEFINE_NFS4_LOOKUP_EVENT(nfs4_mknod);
+DEFINE_NFS4_LOOKUP_EVENT(nfs4_remove);
+DEFINE_NFS4_LOOKUP_EVENT(nfs4_get_fs_locations);
+DEFINE_NFS4_LOOKUP_EVENT(nfs4_secinfo);
+
+TRACE_EVENT(nfs4_lookupp,
+		TP_PROTO(
+			const struct inode *inode,
+			int error
+		),
+
+		TP_ARGS(inode, error),
+
+		TP_STRUCT__entry(
+			__field(dev_t, dev)
+			__field(u64, ino)
+			__field(unsigned long, error)
+		),
+
+		TP_fast_assign(
+			__entry->dev = inode->i_sb->s_dev;
+			__entry->ino = NFS_FILEID(inode);
+			__entry->error = error < 0 ? -error : 0;
+		),
+
+		TP_printk(
+			"error=%ld (%s) inode=%02x:%02x:%llu",
+			-__entry->error,
+			show_nfsv4_errors(__entry->error),
+			MAJOR(__entry->dev), MINOR(__entry->dev),
+			(unsigned long long)__entry->ino
+		)
+);
+
+TRACE_EVENT(nfs4_rename,
+		TP_PROTO(
+			const struct inode *olddir,
+			const struct qstr *oldname,
+			const struct inode *newdir,
+			const struct qstr *newname,
+			int error
+		),
+
+		TP_ARGS(olddir, oldname, newdir, newname, error),
+
+		TP_STRUCT__entry(
+			__field(dev_t, dev)
+			__field(unsigned long, error)
+			__field(u64, olddir)
+			__string(oldname, oldname->name)
+			__field(u64, newdir)
+			__string(newname, newname->name)
+		),
+
+		TP_fast_assign(
+			__entry->dev = olddir->i_sb->s_dev;
+			__entry->olddir = NFS_FILEID(olddir);
+			__entry->newdir = NFS_FILEID(newdir);
+			__entry->error = error < 0 ? -error : 0;
+			__assign_str(oldname, oldname->name);
+			__assign_str(newname, newname->name);
+		),
+
+		TP_printk(
+			"error=%ld (%s) oldname=%02x:%02x:%llu/%s "
+			"newname=%02x:%02x:%llu/%s",
+			-__entry->error,
+			show_nfsv4_errors(__entry->error),
+			MAJOR(__entry->dev), MINOR(__entry->dev),
+			(unsigned long long)__entry->olddir,
+			__get_str(oldname),
+			MAJOR(__entry->dev), MINOR(__entry->dev),
+			(unsigned long long)__entry->newdir,
+			__get_str(newname)
+		)
+);
+
+DECLARE_EVENT_CLASS(nfs4_inode_event,
+		TP_PROTO(
+			const struct inode *inode,
+			int error
+		),
+
+		TP_ARGS(inode, error),
+
+		TP_STRUCT__entry(
+			__field(dev_t, dev)
+			__field(u32, fhandle)
+			__field(u64, fileid)
+			__field(unsigned long, error)
+		),
+
+		TP_fast_assign(
+			__entry->dev = inode->i_sb->s_dev;
+			__entry->fileid = NFS_FILEID(inode);
+			__entry->fhandle = nfs_fhandle_hash(NFS_FH(inode));
+			__entry->error = error < 0 ? -error : 0;
+		),
+
+		TP_printk(
+			"error=%ld (%s) fileid=%02x:%02x:%llu fhandle=0x%08x",
+			-__entry->error,
+			show_nfsv4_errors(__entry->error),
+			MAJOR(__entry->dev), MINOR(__entry->dev),
+			(unsigned long long)__entry->fileid,
+			__entry->fhandle
+		)
+);
+
+#define DEFINE_NFS4_INODE_EVENT(name) \
+	DEFINE_EVENT(nfs4_inode_event, name, \
+			TP_PROTO( \
+				const struct inode *inode, \
+				int error \
+			), \
+			TP_ARGS(inode, error))
+
+DEFINE_NFS4_INODE_EVENT(nfs4_access);
+DEFINE_NFS4_INODE_EVENT(nfs4_readlink);
+DEFINE_NFS4_INODE_EVENT(nfs4_readdir);
+DEFINE_NFS4_INODE_EVENT(nfs4_get_acl);
+DEFINE_NFS4_INODE_EVENT(nfs4_set_acl);
+#ifdef CONFIG_NFS_V4_SECURITY_LABEL
+DEFINE_NFS4_INODE_EVENT(nfs4_get_security_label);
+DEFINE_NFS4_INODE_EVENT(nfs4_set_security_label);
+#endif /* CONFIG_NFS_V4_SECURITY_LABEL */
+
+DECLARE_EVENT_CLASS(nfs4_inode_stateid_event,
+		TP_PROTO(
+			const struct inode *inode,
+			const nfs4_stateid *stateid,
+			int error
+		),
+
+		TP_ARGS(inode, stateid, error),
+
+		TP_STRUCT__entry(
+			__field(dev_t, dev)
+			__field(u32, fhandle)
+			__field(u64, fileid)
+			__field(unsigned long, error)
+			__field(int, stateid_seq)
+			__field(u32, stateid_hash)
+		),
+
+		TP_fast_assign(
+			__entry->dev = inode->i_sb->s_dev;
+			__entry->fileid = NFS_FILEID(inode);
+			__entry->fhandle = nfs_fhandle_hash(NFS_FH(inode));
+			__entry->error = error < 0 ? -error : 0;
+			__entry->stateid_seq =
+				be32_to_cpu(stateid->seqid);
+			__entry->stateid_hash =
+				nfs_stateid_hash(stateid);
+		),
+
+		TP_printk(
+			"error=%ld (%s) fileid=%02x:%02x:%llu fhandle=0x%08x "
+			"stateid=%d:0x%08x",
+			-__entry->error,
+			show_nfsv4_errors(__entry->error),
+			MAJOR(__entry->dev), MINOR(__entry->dev),
+			(unsigned long long)__entry->fileid,
+			__entry->fhandle,
+			__entry->stateid_seq, __entry->stateid_hash
+		)
+);
+
+#define DEFINE_NFS4_INODE_STATEID_EVENT(name) \
+	DEFINE_EVENT(nfs4_inode_stateid_event, name, \
+			TP_PROTO( \
+				const struct inode *inode, \
+				const nfs4_stateid *stateid, \
+				int error \
+			), \
+			TP_ARGS(inode, stateid, error))
+
+DEFINE_NFS4_INODE_STATEID_EVENT(nfs4_setattr);
+DEFINE_NFS4_INODE_STATEID_EVENT(nfs4_delegreturn);
+DEFINE_NFS4_INODE_STATEID_EVENT(nfs4_open_stateid_update);
+DEFINE_NFS4_INODE_STATEID_EVENT(nfs4_open_stateid_update_wait);
+DEFINE_NFS4_INODE_STATEID_EVENT(nfs4_close_stateid_update_wait);
+
+DECLARE_EVENT_CLASS(nfs4_getattr_event,
+		TP_PROTO(
+			const struct nfs_server *server,
+			const struct nfs_fh *fhandle,
+			const struct nfs_fattr *fattr,
+			int error
+		),
+
+		TP_ARGS(server, fhandle, fattr, error),
+
+		TP_STRUCT__entry(
+			__field(dev_t, dev)
+			__field(u32, fhandle)
+			__field(u64, fileid)
+			__field(unsigned int, valid)
+			__field(unsigned long, error)
+		),
+
+		TP_fast_assign(
+			__entry->dev = server->s_dev;
+			__entry->valid = fattr->valid;
+			__entry->fhandle = nfs_fhandle_hash(fhandle);
+			__entry->fileid = (fattr->valid & NFS_ATTR_FATTR_FILEID) ? fattr->fileid : 0;
+			__entry->error = error < 0 ? -error : 0;
+		),
+
+		TP_printk(
+			"error=%ld (%s) fileid=%02x:%02x:%llu fhandle=0x%08x "
+			"valid=%s",
+			-__entry->error,
+			show_nfsv4_errors(__entry->error),
+			MAJOR(__entry->dev), MINOR(__entry->dev),
+			(unsigned long long)__entry->fileid,
+			__entry->fhandle,
+			show_nfs_fattr_flags(__entry->valid)
+		)
+);
+
+#define DEFINE_NFS4_GETATTR_EVENT(name) \
+	DEFINE_EVENT(nfs4_getattr_event, name, \
+			TP_PROTO( \
+				const struct nfs_server *server, \
+				const struct nfs_fh *fhandle, \
+				const struct nfs_fattr *fattr, \
+				int error \
+			), \
+			TP_ARGS(server, fhandle, fattr, error))
+DEFINE_NFS4_GETATTR_EVENT(nfs4_getattr);
+DEFINE_NFS4_GETATTR_EVENT(nfs4_lookup_root);
+DEFINE_NFS4_GETATTR_EVENT(nfs4_fsinfo);
+
+DECLARE_EVENT_CLASS(nfs4_inode_callback_event,
+		TP_PROTO(
+			const struct nfs_client *clp,
+			const struct nfs_fh *fhandle,
+			const struct inode *inode,
+			int error
+		),
+
+		TP_ARGS(clp, fhandle, inode, error),
+
+		TP_STRUCT__entry(
+			__field(unsigned long, error)
+			__field(dev_t, dev)
+			__field(u32, fhandle)
+			__field(u64, fileid)
+			__string(dstaddr, clp ? clp->cl_hostname : "unknown")
+		),
+
+		TP_fast_assign(
+			__entry->error = error < 0 ? -error : 0;
+			__entry->fhandle = nfs_fhandle_hash(fhandle);
+			if (!IS_ERR_OR_NULL(inode)) {
+				__entry->fileid = NFS_FILEID(inode);
+				__entry->dev = inode->i_sb->s_dev;
+			} else {
+				__entry->fileid = 0;
+				__entry->dev = 0;
+			}
+			__assign_str(dstaddr, clp ? clp->cl_hostname : "unknown")
+		),
+
+		TP_printk(
+			"error=%ld (%s) fileid=%02x:%02x:%llu fhandle=0x%08x "
+			"dstaddr=%s",
+			-__entry->error,
+			show_nfsv4_errors(__entry->error),
+			MAJOR(__entry->dev), MINOR(__entry->dev),
+			(unsigned long long)__entry->fileid,
+			__entry->fhandle,
+			__get_str(dstaddr)
+		)
+);
+
+#define DEFINE_NFS4_INODE_CALLBACK_EVENT(name) \
+	DEFINE_EVENT(nfs4_inode_callback_event, name, \
+			TP_PROTO( \
+				const struct nfs_client *clp, \
+				const struct nfs_fh *fhandle, \
+				const struct inode *inode, \
+				int error \
+			), \
+			TP_ARGS(clp, fhandle, inode, error))
+DEFINE_NFS4_INODE_CALLBACK_EVENT(nfs4_cb_getattr);
+
+DECLARE_EVENT_CLASS(nfs4_inode_stateid_callback_event,
+		TP_PROTO(
+			const struct nfs_client *clp,
+			const struct nfs_fh *fhandle,
+			const struct inode *inode,
+			const nfs4_stateid *stateid,
+			int error
+		),
+
+		TP_ARGS(clp, fhandle, inode, stateid, error),
+
+		TP_STRUCT__entry(
+			__field(unsigned long, error)
+			__field(dev_t, dev)
+			__field(u32, fhandle)
+			__field(u64, fileid)
+			__string(dstaddr, clp ? clp->cl_hostname : "unknown")
+			__field(int, stateid_seq)
+			__field(u32, stateid_hash)
+		),
+
+		TP_fast_assign(
+			__entry->error = error < 0 ? -error : 0;
+			__entry->fhandle = nfs_fhandle_hash(fhandle);
+			if (!IS_ERR_OR_NULL(inode)) {
+				__entry->fileid = NFS_FILEID(inode);
+				__entry->dev = inode->i_sb->s_dev;
+			} else {
+				__entry->fileid = 0;
+				__entry->dev = 0;
+			}
+			__assign_str(dstaddr, clp ? clp->cl_hostname : "unknown")
+			__entry->stateid_seq =
+				be32_to_cpu(stateid->seqid);
+			__entry->stateid_hash =
+				nfs_stateid_hash(stateid);
+		),
+
+		TP_printk(
+			"error=%ld (%s) fileid=%02x:%02x:%llu fhandle=0x%08x "
+			"stateid=%d:0x%08x dstaddr=%s",
+			-__entry->error,
+			show_nfsv4_errors(__entry->error),
+			MAJOR(__entry->dev), MINOR(__entry->dev),
+			(unsigned long long)__entry->fileid,
+			__entry->fhandle,
+			__entry->stateid_seq, __entry->stateid_hash,
+			__get_str(dstaddr)
+		)
+);
+
+#define DEFINE_NFS4_INODE_STATEID_CALLBACK_EVENT(name) \
+	DEFINE_EVENT(nfs4_inode_stateid_callback_event, name, \
+			TP_PROTO( \
+				const struct nfs_client *clp, \
+				const struct nfs_fh *fhandle, \
+				const struct inode *inode, \
+				const nfs4_stateid *stateid, \
+				int error \
+			), \
+			TP_ARGS(clp, fhandle, inode, stateid, error))
+DEFINE_NFS4_INODE_STATEID_CALLBACK_EVENT(nfs4_cb_recall);
+DEFINE_NFS4_INODE_STATEID_CALLBACK_EVENT(nfs4_cb_layoutrecall_file);
+
+DECLARE_EVENT_CLASS(nfs4_idmap_event,
+		TP_PROTO(
+			const char *name,
+			int len,
+			u32 id,
+			int error
+		),
+
+		TP_ARGS(name, len, id, error),
+
+		TP_STRUCT__entry(
+			__field(unsigned long, error)
+			__field(u32, id)
+			__dynamic_array(char, name, len > 0 ? len + 1 : 1)
+		),
+
+		TP_fast_assign(
+			if (len < 0)
+				len = 0;
+			__entry->error = error < 0 ? error : 0;
+			__entry->id = id;
+			memcpy(__get_str(name), name, len);
+			__get_str(name)[len] = 0;
+		),
+
+		TP_printk(
+			"error=%ld (%s) id=%u name=%s",
+			-__entry->error, show_nfsv4_errors(__entry->error),
+			__entry->id,
+			__get_str(name)
+		)
+);
+#define DEFINE_NFS4_IDMAP_EVENT(name) \
+	DEFINE_EVENT(nfs4_idmap_event, name, \
+			TP_PROTO( \
+				const char *name, \
+				int len, \
+				u32 id, \
+				int error \
+			), \
+			TP_ARGS(name, len, id, error))
+DEFINE_NFS4_IDMAP_EVENT(nfs4_map_name_to_uid);
+DEFINE_NFS4_IDMAP_EVENT(nfs4_map_group_to_gid);
+DEFINE_NFS4_IDMAP_EVENT(nfs4_map_uid_to_name);
+DEFINE_NFS4_IDMAP_EVENT(nfs4_map_gid_to_group);
+
+#ifdef CONFIG_NFS_V4_1
+#define NFS4_LSEG_LAYOUT_STATEID_HASH(lseg) \
+	(lseg ? nfs_stateid_hash(&lseg->pls_layout->plh_stateid) : 0)
+#else
+#define NFS4_LSEG_LAYOUT_STATEID_HASH(lseg) (0)
+#endif
+
+DECLARE_EVENT_CLASS(nfs4_read_event,
+		TP_PROTO(
+			const struct nfs_pgio_header *hdr,
+			int error
+		),
+
+		TP_ARGS(hdr, error),
+
+		TP_STRUCT__entry(
+			__field(dev_t, dev)
+			__field(u32, fhandle)
+			__field(u64, fileid)
+			__field(loff_t, offset)
+			__field(u32, arg_count)
+			__field(u32, res_count)
+			__field(unsigned long, error)
+			__field(int, stateid_seq)
+			__field(u32, stateid_hash)
+			__field(int, layoutstateid_seq)
+			__field(u32, layoutstateid_hash)
+		),
+
+		TP_fast_assign(
+			const struct inode *inode = hdr->inode;
+			const struct nfs_inode *nfsi = NFS_I(inode);
+			const struct nfs_fh *fh = hdr->args.fh ?
+						  hdr->args.fh : &nfsi->fh;
+			const struct nfs4_state *state =
+				hdr->args.context->state;
+			const struct pnfs_layout_segment *lseg = hdr->lseg;
+
+			__entry->dev = inode->i_sb->s_dev;
+			__entry->fileid = nfsi->fileid;
+			__entry->fhandle = nfs_fhandle_hash(fh);
+			__entry->offset = hdr->args.offset;
+			__entry->arg_count = hdr->args.count;
+			__entry->res_count = hdr->res.count;
+			__entry->error = error < 0 ? -error : 0;
+			__entry->stateid_seq =
+				be32_to_cpu(state->stateid.seqid);
+			__entry->stateid_hash =
+				nfs_stateid_hash(&state->stateid);
+			__entry->layoutstateid_seq = lseg ? lseg->pls_seq : 0;
+			__entry->layoutstateid_hash =
+				NFS4_LSEG_LAYOUT_STATEID_HASH(lseg);
+		),
+
+		TP_printk(
+			"error=%ld (%s) fileid=%02x:%02x:%llu fhandle=0x%08x "
+			"offset=%lld count=%u res=%u stateid=%d:0x%08x "
+			"layoutstateid=%d:0x%08x",
+			-__entry->error,
+			show_nfsv4_errors(__entry->error),
+			MAJOR(__entry->dev), MINOR(__entry->dev),
+			(unsigned long long)__entry->fileid,
+			__entry->fhandle,
+			(long long)__entry->offset,
+			__entry->arg_count, __entry->res_count,
+			__entry->stateid_seq, __entry->stateid_hash,
+			__entry->layoutstateid_seq, __entry->layoutstateid_hash
+		)
+);
+#define DEFINE_NFS4_READ_EVENT(name) \
+	DEFINE_EVENT(nfs4_read_event, name, \
+			TP_PROTO( \
+				const struct nfs_pgio_header *hdr, \
+				int error \
+			), \
+			TP_ARGS(hdr, error))
+DEFINE_NFS4_READ_EVENT(nfs4_read);
+#ifdef CONFIG_NFS_V4_1
+DEFINE_NFS4_READ_EVENT(nfs4_pnfs_read);
+#endif /* CONFIG_NFS_V4_1 */
+
+DECLARE_EVENT_CLASS(nfs4_write_event,
+		TP_PROTO(
+			const struct nfs_pgio_header *hdr,
+			int error
+		),
+
+		TP_ARGS(hdr, error),
+
+		TP_STRUCT__entry(
+			__field(dev_t, dev)
+			__field(u32, fhandle)
+			__field(u64, fileid)
+			__field(loff_t, offset)
+			__field(u32, arg_count)
+			__field(u32, res_count)
+			__field(unsigned long, error)
+			__field(int, stateid_seq)
+			__field(u32, stateid_hash)
+			__field(int, layoutstateid_seq)
+			__field(u32, layoutstateid_hash)
+		),
+
+		TP_fast_assign(
+			const struct inode *inode = hdr->inode;
+			const struct nfs_inode *nfsi = NFS_I(inode);
+			const struct nfs_fh *fh = hdr->args.fh ?
+						  hdr->args.fh : &nfsi->fh;
+			const struct nfs4_state *state =
+				hdr->args.context->state;
+			const struct pnfs_layout_segment *lseg = hdr->lseg;
+
+			__entry->dev = inode->i_sb->s_dev;
+			__entry->fileid = nfsi->fileid;
+			__entry->fhandle = nfs_fhandle_hash(fh);
+			__entry->offset = hdr->args.offset;
+			__entry->arg_count = hdr->args.count;
+			__entry->res_count = hdr->res.count;
+			__entry->error = error < 0 ? -error : 0;
+			__entry->stateid_seq =
+				be32_to_cpu(state->stateid.seqid);
+			__entry->stateid_hash =
+				nfs_stateid_hash(&state->stateid);
+			__entry->layoutstateid_seq = lseg ? lseg->pls_seq : 0;
+			__entry->layoutstateid_hash =
+				NFS4_LSEG_LAYOUT_STATEID_HASH(lseg);
+		),
+
+		TP_printk(
+			"error=%ld (%s) fileid=%02x:%02x:%llu fhandle=0x%08x "
+			"offset=%lld count=%u res=%u stateid=%d:0x%08x "
+			"layoutstateid=%d:0x%08x",
+			-__entry->error,
+			show_nfsv4_errors(__entry->error),
+			MAJOR(__entry->dev), MINOR(__entry->dev),
+			(unsigned long long)__entry->fileid,
+			__entry->fhandle,
+			(long long)__entry->offset,
+			__entry->arg_count, __entry->res_count,
+			__entry->stateid_seq, __entry->stateid_hash,
+			__entry->layoutstateid_seq, __entry->layoutstateid_hash
+		)
+);
+
+#define DEFINE_NFS4_WRITE_EVENT(name) \
+	DEFINE_EVENT(nfs4_write_event, name, \
+			TP_PROTO( \
+				const struct nfs_pgio_header *hdr, \
+				int error \
+			), \
+			TP_ARGS(hdr, error))
+DEFINE_NFS4_WRITE_EVENT(nfs4_write);
+#ifdef CONFIG_NFS_V4_1
+DEFINE_NFS4_WRITE_EVENT(nfs4_pnfs_write);
+#endif /* CONFIG_NFS_V4_1 */
+
+DECLARE_EVENT_CLASS(nfs4_commit_event,
+		TP_PROTO(
+			const struct nfs_commit_data *data,
+			int error
+		),
+
+		TP_ARGS(data, error),
+
+		TP_STRUCT__entry(
+			__field(dev_t, dev)
+			__field(u32, fhandle)
+			__field(u64, fileid)
+			__field(unsigned long, error)
+			__field(loff_t, offset)
+			__field(u32, count)
+			__field(int, layoutstateid_seq)
+			__field(u32, layoutstateid_hash)
+		),
+
+		TP_fast_assign(
+			const struct inode *inode = data->inode;
+			const struct nfs_inode *nfsi = NFS_I(inode);
+			const struct nfs_fh *fh = data->args.fh ?
+						  data->args.fh : &nfsi->fh;
+			const struct pnfs_layout_segment *lseg = data->lseg;
+
+			__entry->dev = inode->i_sb->s_dev;
+			__entry->fileid = nfsi->fileid;
+			__entry->fhandle = nfs_fhandle_hash(fh);
+			__entry->offset = data->args.offset;
+			__entry->count = data->args.count;
+			__entry->error = error < 0 ? -error : 0;
+			__entry->layoutstateid_seq = lseg ? lseg->pls_seq : 0;
+			__entry->layoutstateid_hash =
+				NFS4_LSEG_LAYOUT_STATEID_HASH(lseg);
+		),
+
+		TP_printk(
+			"error=%ld (%s) fileid=%02x:%02x:%llu fhandle=0x%08x "
+			"offset=%lld count=%u layoutstateid=%d:0x%08x",
+			-__entry->error,
+			show_nfsv4_errors(__entry->error),
+			MAJOR(__entry->dev), MINOR(__entry->dev),
+			(unsigned long long)__entry->fileid,
+			__entry->fhandle,
+			(long long)__entry->offset,
+			__entry->count,
+			__entry->layoutstateid_seq, __entry->layoutstateid_hash
+		)
+);
+#define DEFINE_NFS4_COMMIT_EVENT(name) \
+	DEFINE_EVENT(nfs4_commit_event, name, \
+			TP_PROTO( \
+				const struct nfs_commit_data *data, \
+				int error \
+			), \
+			TP_ARGS(data, error))
+DEFINE_NFS4_COMMIT_EVENT(nfs4_commit);
+#ifdef CONFIG_NFS_V4_1
+DEFINE_NFS4_COMMIT_EVENT(nfs4_pnfs_commit_ds);
+
+TRACE_DEFINE_ENUM(IOMODE_READ);
+TRACE_DEFINE_ENUM(IOMODE_RW);
+TRACE_DEFINE_ENUM(IOMODE_ANY);
+
+#define show_pnfs_iomode(iomode) \
+	__print_symbolic(iomode, \
+		{ IOMODE_READ, "READ" }, \
+		{ IOMODE_RW, "RW" }, \
+		{ IOMODE_ANY, "ANY" })
+
+TRACE_EVENT(nfs4_layoutget,
+		TP_PROTO(
+			const struct nfs_open_context *ctx,
+			const struct pnfs_layout_range *args,
+			const struct pnfs_layout_range *res,
+			const nfs4_stateid *layout_stateid,
+			int error
+		),
+
+		TP_ARGS(ctx, args, res, layout_stateid, error),
+
+		TP_STRUCT__entry(
+			__field(dev_t, dev)
+			__field(u32, fhandle)
+			__field(u64, fileid)
+			__field(u32, iomode)
+			__field(u64, offset)
+			__field(u64, count)
+			__field(unsigned long, error)
+			__field(int, stateid_seq)
+			__field(u32, stateid_hash)
+			__field(int, layoutstateid_seq)
+			__field(u32, layoutstateid_hash)
+		),
+
+		TP_fast_assign(
+			const struct inode *inode = d_inode(ctx->dentry);
+			const struct nfs4_state *state = ctx->state;
+			__entry->dev = inode->i_sb->s_dev;
+			__entry->fileid = NFS_FILEID(inode);
+			__entry->fhandle = nfs_fhandle_hash(NFS_FH(inode));
+			__entry->iomode = args->iomode;
+			__entry->offset = args->offset;
+			__entry->count = args->length;
+			__entry->error = error < 0 ? -error : 0;
+			__entry->stateid_seq =
+				be32_to_cpu(state->stateid.seqid);
+			__entry->stateid_hash =
+				nfs_stateid_hash(&state->stateid);
+			if (!error) {
+				__entry->layoutstateid_seq =
+				be32_to_cpu(layout_stateid->seqid);
+				__entry->layoutstateid_hash =
+				nfs_stateid_hash(layout_stateid);
+			} else {
+				__entry->layoutstateid_seq = 0;
+				__entry->layoutstateid_hash = 0;
+			}
+		),
+
+		TP_printk(
+			"error=%ld (%s) fileid=%02x:%02x:%llu fhandle=0x%08x "
+			"iomode=%s offset=%llu count=%llu stateid=%d:0x%08x "
+			"layoutstateid=%d:0x%08x",
+			-__entry->error,
+			show_nfsv4_errors(__entry->error),
+			MAJOR(__entry->dev), MINOR(__entry->dev),
+			(unsigned long long)__entry->fileid,
+			__entry->fhandle,
+			show_pnfs_iomode(__entry->iomode),
+			(unsigned long long)__entry->offset,
+			(unsigned long long)__entry->count,
+			__entry->stateid_seq, __entry->stateid_hash,
+			__entry->layoutstateid_seq, __entry->layoutstateid_hash
+		)
+);
+
+DEFINE_NFS4_INODE_STATEID_EVENT(nfs4_layoutcommit);
+DEFINE_NFS4_INODE_STATEID_EVENT(nfs4_layoutreturn);
+DEFINE_NFS4_INODE_STATEID_EVENT(nfs4_layoutreturn_on_close);
+DEFINE_NFS4_INODE_STATEID_EVENT(nfs4_layouterror);
+DEFINE_NFS4_INODE_STATEID_EVENT(nfs4_layoutstats);
+
+TRACE_DEFINE_ENUM(PNFS_UPDATE_LAYOUT_UNKNOWN);
+TRACE_DEFINE_ENUM(PNFS_UPDATE_LAYOUT_NO_PNFS);
+TRACE_DEFINE_ENUM(PNFS_UPDATE_LAYOUT_RD_ZEROLEN);
+TRACE_DEFINE_ENUM(PNFS_UPDATE_LAYOUT_MDSTHRESH);
+TRACE_DEFINE_ENUM(PNFS_UPDATE_LAYOUT_NOMEM);
+TRACE_DEFINE_ENUM(PNFS_UPDATE_LAYOUT_BULK_RECALL);
+TRACE_DEFINE_ENUM(PNFS_UPDATE_LAYOUT_IO_TEST_FAIL);
+TRACE_DEFINE_ENUM(PNFS_UPDATE_LAYOUT_FOUND_CACHED);
+TRACE_DEFINE_ENUM(PNFS_UPDATE_LAYOUT_RETURN);
+TRACE_DEFINE_ENUM(PNFS_UPDATE_LAYOUT_BLOCKED);
+TRACE_DEFINE_ENUM(PNFS_UPDATE_LAYOUT_INVALID_OPEN);
+TRACE_DEFINE_ENUM(PNFS_UPDATE_LAYOUT_RETRY);
+TRACE_DEFINE_ENUM(PNFS_UPDATE_LAYOUT_SEND_LAYOUTGET);
+TRACE_DEFINE_ENUM(PNFS_UPDATE_LAYOUT_EXIT);
+
+#define show_pnfs_update_layout_reason(reason)				\
+	__print_symbolic(reason,					\
+		{ PNFS_UPDATE_LAYOUT_UNKNOWN, "unknown" },		\
+		{ PNFS_UPDATE_LAYOUT_NO_PNFS, "no pnfs" },		\
+		{ PNFS_UPDATE_LAYOUT_RD_ZEROLEN, "read+zerolen" },	\
+		{ PNFS_UPDATE_LAYOUT_MDSTHRESH, "mdsthresh" },		\
+		{ PNFS_UPDATE_LAYOUT_NOMEM, "nomem" },			\
+		{ PNFS_UPDATE_LAYOUT_BULK_RECALL, "bulk recall" },	\
+		{ PNFS_UPDATE_LAYOUT_IO_TEST_FAIL, "io test fail" },	\
+		{ PNFS_UPDATE_LAYOUT_FOUND_CACHED, "found cached" },	\
+		{ PNFS_UPDATE_LAYOUT_RETURN, "layoutreturn" },		\
+		{ PNFS_UPDATE_LAYOUT_BLOCKED, "layouts blocked" },	\
+		{ PNFS_UPDATE_LAYOUT_INVALID_OPEN, "invalid open" },	\
+		{ PNFS_UPDATE_LAYOUT_RETRY, "retrying" },	\
+		{ PNFS_UPDATE_LAYOUT_SEND_LAYOUTGET, "sent layoutget" }, \
+		{ PNFS_UPDATE_LAYOUT_EXIT, "exit" })
+
+TRACE_EVENT(pnfs_update_layout,
+		TP_PROTO(struct inode *inode,
+			loff_t pos,
+			u64 count,
+			enum pnfs_iomode iomode,
+			struct pnfs_layout_hdr *lo,
+			struct pnfs_layout_segment *lseg,
+			enum pnfs_update_layout_reason reason
+		),
+		TP_ARGS(inode, pos, count, iomode, lo, lseg, reason),
+		TP_STRUCT__entry(
+			__field(dev_t, dev)
+			__field(u64, fileid)
+			__field(u32, fhandle)
+			__field(loff_t, pos)
+			__field(u64, count)
+			__field(enum pnfs_iomode, iomode)
+			__field(int, layoutstateid_seq)
+			__field(u32, layoutstateid_hash)
+			__field(long, lseg)
+			__field(enum pnfs_update_layout_reason, reason)
+		),
+		TP_fast_assign(
+			__entry->dev = inode->i_sb->s_dev;
+			__entry->fileid = NFS_FILEID(inode);
+			__entry->fhandle = nfs_fhandle_hash(NFS_FH(inode));
+			__entry->pos = pos;
+			__entry->count = count;
+			__entry->iomode = iomode;
+			__entry->reason = reason;
+			if (lo != NULL) {
+				__entry->layoutstateid_seq =
+				be32_to_cpu(lo->plh_stateid.seqid);
+				__entry->layoutstateid_hash =
+				nfs_stateid_hash(&lo->plh_stateid);
+			} else {
+				__entry->layoutstateid_seq = 0;
+				__entry->layoutstateid_hash = 0;
+			}
+			__entry->lseg = (long)lseg;
+		),
+		TP_printk(
+			"fileid=%02x:%02x:%llu fhandle=0x%08x "
+			"iomode=%s pos=%llu count=%llu "
+			"layoutstateid=%d:0x%08x lseg=0x%lx (%s)",
+			MAJOR(__entry->dev), MINOR(__entry->dev),
+			(unsigned long long)__entry->fileid,
+			__entry->fhandle,
+			show_pnfs_iomode(__entry->iomode),
+			(unsigned long long)__entry->pos,
+			(unsigned long long)__entry->count,
+			__entry->layoutstateid_seq, __entry->layoutstateid_hash,
+			__entry->lseg,
+			show_pnfs_update_layout_reason(__entry->reason)
+		)
+);
+
+DECLARE_EVENT_CLASS(pnfs_layout_event,
+		TP_PROTO(struct inode *inode,
+			loff_t pos,
+			u64 count,
+			enum pnfs_iomode iomode,
+			struct pnfs_layout_hdr *lo,
+			struct pnfs_layout_segment *lseg
+		),
+		TP_ARGS(inode, pos, count, iomode, lo, lseg),
+		TP_STRUCT__entry(
+			__field(dev_t, dev)
+			__field(u64, fileid)
+			__field(u32, fhandle)
+			__field(loff_t, pos)
+			__field(u64, count)
+			__field(enum pnfs_iomode, iomode)
+			__field(int, layoutstateid_seq)
+			__field(u32, layoutstateid_hash)
+			__field(long, lseg)
+		),
+		TP_fast_assign(
+			__entry->dev = inode->i_sb->s_dev;
+			__entry->fileid = NFS_FILEID(inode);
+			__entry->fhandle = nfs_fhandle_hash(NFS_FH(inode));
+			__entry->pos = pos;
+			__entry->count = count;
+			__entry->iomode = iomode;
+			if (lo != NULL) {
+				__entry->layoutstateid_seq =
+				be32_to_cpu(lo->plh_stateid.seqid);
+				__entry->layoutstateid_hash =
+				nfs_stateid_hash(&lo->plh_stateid);
+			} else {
+				__entry->layoutstateid_seq = 0;
+				__entry->layoutstateid_hash = 0;
+			}
+			__entry->lseg = (long)lseg;
+		),
+		TP_printk(
+			"fileid=%02x:%02x:%llu fhandle=0x%08x "
+			"iomode=%s pos=%llu count=%llu "
+			"layoutstateid=%d:0x%08x lseg=0x%lx",
+			MAJOR(__entry->dev), MINOR(__entry->dev),
+			(unsigned long long)__entry->fileid,
+			__entry->fhandle,
+			show_pnfs_iomode(__entry->iomode),
+			(unsigned long long)__entry->pos,
+			(unsigned long long)__entry->count,
+			__entry->layoutstateid_seq, __entry->layoutstateid_hash,
+			__entry->lseg
+		)
+);
+
+#define DEFINE_PNFS_LAYOUT_EVENT(name) \
+	DEFINE_EVENT(pnfs_layout_event, name, \
+		TP_PROTO(struct inode *inode, \
+			loff_t pos, \
+			u64 count, \
+			enum pnfs_iomode iomode, \
+			struct pnfs_layout_hdr *lo, \
+			struct pnfs_layout_segment *lseg \
+		), \
+		TP_ARGS(inode, pos, count, iomode, lo, lseg))
+
+DEFINE_PNFS_LAYOUT_EVENT(pnfs_mds_fallback_pg_init_read);
+DEFINE_PNFS_LAYOUT_EVENT(pnfs_mds_fallback_pg_init_write);
+DEFINE_PNFS_LAYOUT_EVENT(pnfs_mds_fallback_pg_get_mirror_count);
+DEFINE_PNFS_LAYOUT_EVENT(pnfs_mds_fallback_read_done);
+DEFINE_PNFS_LAYOUT_EVENT(pnfs_mds_fallback_write_done);
+DEFINE_PNFS_LAYOUT_EVENT(pnfs_mds_fallback_read_pagelist);
+DEFINE_PNFS_LAYOUT_EVENT(pnfs_mds_fallback_write_pagelist);
+
+DECLARE_EVENT_CLASS(nfs4_flexfiles_io_event,
+		TP_PROTO(
+			const struct nfs_pgio_header *hdr
+		),
+
+		TP_ARGS(hdr),
+
+		TP_STRUCT__entry(
+			__field(unsigned long, error)
+			__field(dev_t, dev)
+			__field(u32, fhandle)
+			__field(u64, fileid)
+			__field(loff_t, offset)
+			__field(u32, count)
+			__field(int, stateid_seq)
+			__field(u32, stateid_hash)
+			__string(dstaddr, hdr->ds_clp ?
+				rpc_peeraddr2str(hdr->ds_clp->cl_rpcclient,
+					RPC_DISPLAY_ADDR) : "unknown")
+		),
+
+		TP_fast_assign(
+			const struct inode *inode = hdr->inode;
+
+			__entry->error = hdr->res.op_status;
+			__entry->fhandle = nfs_fhandle_hash(hdr->args.fh);
+			__entry->fileid = NFS_FILEID(inode);
+			__entry->dev = inode->i_sb->s_dev;
+			__entry->offset = hdr->args.offset;
+			__entry->count = hdr->args.count;
+			__entry->stateid_seq =
+				be32_to_cpu(hdr->args.stateid.seqid);
+			__entry->stateid_hash =
+				nfs_stateid_hash(&hdr->args.stateid);
+			__assign_str(dstaddr, hdr->ds_clp ?
+				rpc_peeraddr2str(hdr->ds_clp->cl_rpcclient,
+					RPC_DISPLAY_ADDR) : "unknown");
+		),
+
+		TP_printk(
+			"error=%ld (%s) fileid=%02x:%02x:%llu fhandle=0x%08x "
+			"offset=%llu count=%u stateid=%d:0x%08x dstaddr=%s",
+			-__entry->error,
+			show_nfsv4_errors(__entry->error),
+			MAJOR(__entry->dev), MINOR(__entry->dev),
+			(unsigned long long)__entry->fileid,
+			__entry->fhandle,
+			__entry->offset, __entry->count,
+			__entry->stateid_seq, __entry->stateid_hash,
+			__get_str(dstaddr)
+		)
+);
+
+#define DEFINE_NFS4_FLEXFILES_IO_EVENT(name) \
+	DEFINE_EVENT(nfs4_flexfiles_io_event, name, \
+			TP_PROTO( \
+				const struct nfs_pgio_header *hdr \
+			), \
+			TP_ARGS(hdr))
+DEFINE_NFS4_FLEXFILES_IO_EVENT(ff_layout_read_error);
+DEFINE_NFS4_FLEXFILES_IO_EVENT(ff_layout_write_error);
+
+TRACE_EVENT(ff_layout_commit_error,
+		TP_PROTO(
+			const struct nfs_commit_data *data
+		),
+
+		TP_ARGS(data),
+
+		TP_STRUCT__entry(
+			__field(unsigned long, error)
+			__field(dev_t, dev)
+			__field(u32, fhandle)
+			__field(u64, fileid)
+			__field(loff_t, offset)
+			__field(u32, count)
+			__string(dstaddr, data->ds_clp ?
+				rpc_peeraddr2str(data->ds_clp->cl_rpcclient,
+					RPC_DISPLAY_ADDR) : "unknown")
+		),
+
+		TP_fast_assign(
+			const struct inode *inode = data->inode;
+
+			__entry->error = data->res.op_status;
+			__entry->fhandle = nfs_fhandle_hash(data->args.fh);
+			__entry->fileid = NFS_FILEID(inode);
+			__entry->dev = inode->i_sb->s_dev;
+			__entry->offset = data->args.offset;
+			__entry->count = data->args.count;
+			__assign_str(dstaddr, data->ds_clp ?
+				rpc_peeraddr2str(data->ds_clp->cl_rpcclient,
+					RPC_DISPLAY_ADDR) : "unknown");
+		),
+
+		TP_printk(
+			"error=%ld (%s) fileid=%02x:%02x:%llu fhandle=0x%08x "
+			"offset=%llu count=%u dstaddr=%s",
+			-__entry->error,
+			show_nfsv4_errors(__entry->error),
+			MAJOR(__entry->dev), MINOR(__entry->dev),
+			(unsigned long long)__entry->fileid,
+			__entry->fhandle,
+			__entry->offset, __entry->count,
+			__get_str(dstaddr)
+		)
+);
+
+
+#endif /* CONFIG_NFS_V4_1 */
+
+#endif /* _TRACE_NFS4_H */
+
+#undef TRACE_INCLUDE_PATH
+#define TRACE_INCLUDE_PATH .
+#define TRACE_INCLUDE_FILE nfs4trace
+/* This part must be outside protection */
+#include <trace/define_trace.h>
diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
new file mode 100644
index 000000000..f1e599553
--- /dev/null
+++ b/fs/nfs/nfs4xdr.c
@@ -0,0 +1,7634 @@
+/*
+ *  fs/nfs/nfs4xdr.c
+ *
+ *  Client-side XDR for NFSv4.
+ *
+ *  Copyright (c) 2002 The Regents of the University of Michigan.
+ *  All rights reserved.
+ *
+ *  Kendrick Smith <kmsmith@umich.edu>
+ *  Andy Adamson   <andros@umich.edu>
+ *
+ *  Redistribution and use in source and binary forms, with or without
+ *  modification, are permitted provided that the following conditions
+ *  are met:
+ *
+ *  1. Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *  2. Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *  3. Neither the name of the University nor the names of its
+ *     contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+ *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <linux/param.h>
+#include <linux/time.h>
+#include <linux/mm.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/in.h>
+#include <linux/pagemap.h>
+#include <linux/proc_fs.h>
+#include <linux/kdev_t.h>
+#include <linux/module.h>
+#include <linux/utsname.h>
+#include <linux/sunrpc/clnt.h>
+#include <linux/sunrpc/msg_prot.h>
+#include <linux/sunrpc/gss_api.h>
+#include <linux/nfs.h>
+#include <linux/nfs4.h>
+#include <linux/nfs_fs.h>
+
+#include "nfs4_fs.h"
+#include "nfs4trace.h"
+#include "internal.h"
+#include "nfs4idmap.h"
+#include "nfs4session.h"
+#include "pnfs.h"
+#include "netns.h"
+
+#define NFSDBG_FACILITY		NFSDBG_XDR
+
+/* Mapping from NFS error code to "errno" error code. */
+#define errno_NFSERR_IO		EIO
+
+struct compound_hdr;
+static int nfs4_stat_to_errno(int);
+static void encode_layoutget(struct xdr_stream *xdr,
+			     const struct nfs4_layoutget_args *args,
+			     struct compound_hdr *hdr);
+static int decode_layoutget(struct xdr_stream *xdr, struct rpc_rqst *req,
+			     struct nfs4_layoutget_res *res);
+
+/* NFSv4 COMPOUND tags are only wanted for debugging purposes */
+#ifdef DEBUG
+#define NFS4_MAXTAGLEN		20
+#else
+#define NFS4_MAXTAGLEN		0
+#endif
+
+/* lock,open owner id:
+ * we currently use size 2 (u64) out of (NFS4_OPAQUE_LIMIT  >> 2)
+ */
+#define open_owner_id_maxsz	(1 + 2 + 1 + 1 + 2)
+#define lock_owner_id_maxsz	(1 + 1 + 4)
+#define decode_lockowner_maxsz	(1 + XDR_QUADLEN(IDMAP_NAMESZ))
+#define compound_encode_hdr_maxsz	(3 + (NFS4_MAXTAGLEN >> 2))
+#define compound_decode_hdr_maxsz	(3 + (NFS4_MAXTAGLEN >> 2))
+#define op_encode_hdr_maxsz	(1)
+#define op_decode_hdr_maxsz	(2)
+#define encode_stateid_maxsz	(XDR_QUADLEN(NFS4_STATEID_SIZE))
+#define decode_stateid_maxsz	(XDR_QUADLEN(NFS4_STATEID_SIZE))
+#define encode_verifier_maxsz	(XDR_QUADLEN(NFS4_VERIFIER_SIZE))
+#define decode_verifier_maxsz	(XDR_QUADLEN(NFS4_VERIFIER_SIZE))
+#define encode_putfh_maxsz	(op_encode_hdr_maxsz + 1 + \
+				(NFS4_FHSIZE >> 2))
+#define decode_putfh_maxsz	(op_decode_hdr_maxsz)
+#define encode_putrootfh_maxsz	(op_encode_hdr_maxsz)
+#define decode_putrootfh_maxsz	(op_decode_hdr_maxsz)
+#define encode_getfh_maxsz      (op_encode_hdr_maxsz)
+#define decode_getfh_maxsz      (op_decode_hdr_maxsz + 1 + \
+				((3+NFS4_FHSIZE) >> 2))
+#define nfs4_fattr_bitmap_maxsz 4
+#define encode_getattr_maxsz    (op_encode_hdr_maxsz + nfs4_fattr_bitmap_maxsz)
+#define nfstime4_maxsz		(3)
+#define nfs4_name_maxsz		(1 + ((3 + NFS4_MAXNAMLEN) >> 2))
+#define nfs4_path_maxsz		(1 + ((3 + NFS4_MAXPATHLEN) >> 2))
+#define nfs4_owner_maxsz	(1 + XDR_QUADLEN(IDMAP_NAMESZ))
+#define nfs4_group_maxsz	(1 + XDR_QUADLEN(IDMAP_NAMESZ))
+#ifdef CONFIG_NFS_V4_SECURITY_LABEL
+/* PI(4 bytes) + LFS(4 bytes) + 1(for null terminator?) + MAXLABELLEN */
+#define	nfs4_label_maxsz	(4 + 4 + 1 + XDR_QUADLEN(NFS4_MAXLABELLEN))
+#else
+#define	nfs4_label_maxsz	0
+#endif
+/* We support only one layout type per file system */
+#define decode_mdsthreshold_maxsz (1 + 1 + nfs4_fattr_bitmap_maxsz + 1 + 8)
+/* This is based on getfattr, which uses the most attributes: */
+#define nfs4_fattr_value_maxsz	(1 + (1 + 2 + 2 + 4 + 2 + 1 + 1 + 2 + 2 + \
+				3*nfstime4_maxsz + \
+				nfs4_owner_maxsz + \
+				nfs4_group_maxsz + nfs4_label_maxsz + \
+				 decode_mdsthreshold_maxsz))
+#define nfs4_fattr_maxsz	(nfs4_fattr_bitmap_maxsz + \
+				nfs4_fattr_value_maxsz)
+#define decode_getattr_maxsz    (op_decode_hdr_maxsz + nfs4_fattr_maxsz)
+#define encode_attrs_maxsz	(nfs4_fattr_bitmap_maxsz + \
+				 1 + 2 + 1 + \
+				nfs4_owner_maxsz + \
+				nfs4_group_maxsz + \
+				nfs4_label_maxsz + \
+				1 + nfstime4_maxsz + \
+				1 + nfstime4_maxsz)
+#define encode_savefh_maxsz     (op_encode_hdr_maxsz)
+#define decode_savefh_maxsz     (op_decode_hdr_maxsz)
+#define encode_restorefh_maxsz  (op_encode_hdr_maxsz)
+#define decode_restorefh_maxsz  (op_decode_hdr_maxsz)
+#define encode_fsinfo_maxsz	(encode_getattr_maxsz)
+/* The 5 accounts for the PNFS attributes, and assumes that at most three
+ * layout types will be returned.
+ */
+#define decode_fsinfo_maxsz	(op_decode_hdr_maxsz + \
+				 nfs4_fattr_bitmap_maxsz + 4 + 8 + 5)
+#define encode_renew_maxsz	(op_encode_hdr_maxsz + 3)
+#define decode_renew_maxsz	(op_decode_hdr_maxsz)
+#define encode_setclientid_maxsz \
+				(op_encode_hdr_maxsz + \
+				XDR_QUADLEN(NFS4_VERIFIER_SIZE) + \
+				/* client name */ \
+				1 + XDR_QUADLEN(NFS4_OPAQUE_LIMIT) + \
+				1 /* sc_prog */ + \
+				1 + XDR_QUADLEN(RPCBIND_MAXNETIDLEN) + \
+				1 + XDR_QUADLEN(RPCBIND_MAXUADDRLEN) + \
+				1) /* sc_cb_ident */
+#define decode_setclientid_maxsz \
+				(op_decode_hdr_maxsz + \
+				2 /* clientid */ + \
+				XDR_QUADLEN(NFS4_VERIFIER_SIZE) + \
+				1 + XDR_QUADLEN(RPCBIND_MAXNETIDLEN) + \
+				1 + XDR_QUADLEN(RPCBIND_MAXUADDRLEN))
+#define encode_setclientid_confirm_maxsz \
+				(op_encode_hdr_maxsz + \
+				3 + (NFS4_VERIFIER_SIZE >> 2))
+#define decode_setclientid_confirm_maxsz \
+				(op_decode_hdr_maxsz)
+#define encode_lookup_maxsz	(op_encode_hdr_maxsz + nfs4_name_maxsz)
+#define decode_lookup_maxsz	(op_decode_hdr_maxsz)
+#define encode_lookupp_maxsz	(op_encode_hdr_maxsz)
+#define decode_lookupp_maxsz	(op_decode_hdr_maxsz)
+#define encode_share_access_maxsz \
+				(2)
+#define encode_createmode_maxsz	(1 + encode_attrs_maxsz + encode_verifier_maxsz)
+#define encode_opentype_maxsz	(1 + encode_createmode_maxsz)
+#define encode_claim_null_maxsz	(1 + nfs4_name_maxsz)
+#define encode_open_maxsz	(op_encode_hdr_maxsz + \
+				2 + encode_share_access_maxsz + 2 + \
+				open_owner_id_maxsz + \
+				encode_opentype_maxsz + \
+				encode_claim_null_maxsz)
+#define decode_space_limit_maxsz	(3)
+#define decode_ace_maxsz	(3 + nfs4_owner_maxsz)
+#define decode_delegation_maxsz	(1 + decode_stateid_maxsz + 1 + \
+				decode_space_limit_maxsz + \
+				decode_ace_maxsz)
+#define decode_change_info_maxsz	(5)
+#define decode_open_maxsz	(op_decode_hdr_maxsz + \
+				decode_stateid_maxsz + \
+				decode_change_info_maxsz + 1 + \
+				nfs4_fattr_bitmap_maxsz + \
+				decode_delegation_maxsz)
+#define encode_open_confirm_maxsz \
+				(op_encode_hdr_maxsz + \
+				 encode_stateid_maxsz + 1)
+#define decode_open_confirm_maxsz \
+				(op_decode_hdr_maxsz + \
+				 decode_stateid_maxsz)
+#define encode_open_downgrade_maxsz \
+				(op_encode_hdr_maxsz + \
+				 encode_stateid_maxsz + 1 + \
+				 encode_share_access_maxsz)
+#define decode_open_downgrade_maxsz \
+				(op_decode_hdr_maxsz + \
+				 decode_stateid_maxsz)
+#define encode_close_maxsz	(op_encode_hdr_maxsz + \
+				 1 + encode_stateid_maxsz)
+#define decode_close_maxsz	(op_decode_hdr_maxsz + \
+				 decode_stateid_maxsz)
+#define encode_setattr_maxsz	(op_encode_hdr_maxsz + \
+				 encode_stateid_maxsz + \
+				 encode_attrs_maxsz)
+#define decode_setattr_maxsz	(op_decode_hdr_maxsz + \
+				 nfs4_fattr_bitmap_maxsz)
+#define encode_read_maxsz	(op_encode_hdr_maxsz + \
+				 encode_stateid_maxsz + 3)
+#define decode_read_maxsz	(op_decode_hdr_maxsz + 2 + 1)
+#define encode_readdir_maxsz	(op_encode_hdr_maxsz + \
+				 2 + encode_verifier_maxsz + 5 + \
+				nfs4_label_maxsz)
+#define decode_readdir_maxsz	(op_decode_hdr_maxsz + \
+				 decode_verifier_maxsz + 1)
+#define encode_readlink_maxsz	(op_encode_hdr_maxsz)
+#define decode_readlink_maxsz	(op_decode_hdr_maxsz + 1 + 1)
+#define encode_write_maxsz	(op_encode_hdr_maxsz + \
+				 encode_stateid_maxsz + 4)
+#define decode_write_maxsz	(op_decode_hdr_maxsz + \
+				 2 + decode_verifier_maxsz)
+#define encode_commit_maxsz	(op_encode_hdr_maxsz + 3)
+#define decode_commit_maxsz	(op_decode_hdr_maxsz + \
+				 decode_verifier_maxsz)
+#define encode_remove_maxsz	(op_encode_hdr_maxsz + \
+				nfs4_name_maxsz)
+#define decode_remove_maxsz	(op_decode_hdr_maxsz + \
+				 decode_change_info_maxsz)
+#define encode_rename_maxsz	(op_encode_hdr_maxsz + \
+				2 * nfs4_name_maxsz)
+#define decode_rename_maxsz	(op_decode_hdr_maxsz + \
+				 decode_change_info_maxsz + \
+				 decode_change_info_maxsz)
+#define encode_link_maxsz	(op_encode_hdr_maxsz + \
+				nfs4_name_maxsz)
+#define decode_link_maxsz	(op_decode_hdr_maxsz + decode_change_info_maxsz)
+#define encode_lockowner_maxsz	(7)
+#define encode_lock_maxsz	(op_encode_hdr_maxsz + \
+				 7 + \
+				 1 + encode_stateid_maxsz + 1 + \
+				 encode_lockowner_maxsz)
+#define decode_lock_denied_maxsz \
+				(8 + decode_lockowner_maxsz)
+#define decode_lock_maxsz	(op_decode_hdr_maxsz + \
+				 decode_lock_denied_maxsz)
+#define encode_lockt_maxsz	(op_encode_hdr_maxsz + 5 + \
+				encode_lockowner_maxsz)
+#define decode_lockt_maxsz	(op_decode_hdr_maxsz + \
+				 decode_lock_denied_maxsz)
+#define encode_locku_maxsz	(op_encode_hdr_maxsz + 3 + \
+				 encode_stateid_maxsz + \
+				 4)
+#define decode_locku_maxsz	(op_decode_hdr_maxsz + \
+				 decode_stateid_maxsz)
+#define encode_release_lockowner_maxsz \
+				(op_encode_hdr_maxsz + \
+				 encode_lockowner_maxsz)
+#define decode_release_lockowner_maxsz \
+				(op_decode_hdr_maxsz)
+#define encode_access_maxsz	(op_encode_hdr_maxsz + 1)
+#define decode_access_maxsz	(op_decode_hdr_maxsz + 2)
+#define encode_symlink_maxsz	(op_encode_hdr_maxsz + \
+				1 + nfs4_name_maxsz + \
+				1 + \
+				nfs4_fattr_maxsz)
+#define decode_symlink_maxsz	(op_decode_hdr_maxsz + 8)
+#define encode_create_maxsz	(op_encode_hdr_maxsz + \
+				1 + 2 + nfs4_name_maxsz + \
+				encode_attrs_maxsz)
+#define decode_create_maxsz	(op_decode_hdr_maxsz + \
+				decode_change_info_maxsz + \
+				nfs4_fattr_bitmap_maxsz)
+#define encode_statfs_maxsz	(encode_getattr_maxsz)
+#define decode_statfs_maxsz	(decode_getattr_maxsz)
+#define encode_delegreturn_maxsz (op_encode_hdr_maxsz + 4)
+#define decode_delegreturn_maxsz (op_decode_hdr_maxsz)
+#define encode_getacl_maxsz	(encode_getattr_maxsz)
+#define decode_getacl_maxsz	(op_decode_hdr_maxsz + \
+				 nfs4_fattr_bitmap_maxsz + 1 + 1)
+#define encode_setacl_maxsz	(op_encode_hdr_maxsz + \
+				 encode_stateid_maxsz + 3)
+#define decode_setacl_maxsz	(decode_setattr_maxsz)
+#define encode_fs_locations_maxsz \
+				(encode_getattr_maxsz)
+#define decode_fs_locations_maxsz \
+				(1)
+#define encode_secinfo_maxsz	(op_encode_hdr_maxsz + nfs4_name_maxsz)
+#define decode_secinfo_maxsz	(op_decode_hdr_maxsz + 1 + ((NFS_MAX_SECFLAVORS * (16 + GSS_OID_MAX_LEN)) / 4))
+
+#if defined(CONFIG_NFS_V4_1)
+#define NFS4_MAX_MACHINE_NAME_LEN (64)
+#define IMPL_NAME_LIMIT (sizeof(utsname()->sysname) + sizeof(utsname()->release) + \
+			 sizeof(utsname()->version) + sizeof(utsname()->machine) + 8)
+
+#define encode_exchange_id_maxsz (op_encode_hdr_maxsz + \
+				encode_verifier_maxsz + \
+				1 /* co_ownerid.len */ + \
+				/* eia_clientowner */ \
+				1 + XDR_QUADLEN(NFS4_OPAQUE_LIMIT) + \
+				1 /* flags */ + \
+				1 /* spa_how */ + \
+				/* max is SP4_MACH_CRED (for now) */ + \
+				1 + NFS4_OP_MAP_NUM_WORDS + \
+				1 + NFS4_OP_MAP_NUM_WORDS + \
+				1 /* implementation id array of size 1 */ + \
+				1 /* nii_domain */ + \
+				XDR_QUADLEN(NFS4_OPAQUE_LIMIT) + \
+				1 /* nii_name */ + \
+				XDR_QUADLEN(IMPL_NAME_LIMIT) + \
+				3 /* nii_date */)
+#define decode_exchange_id_maxsz (op_decode_hdr_maxsz + \
+				2 /* eir_clientid */ + \
+				1 /* eir_sequenceid */ + \
+				1 /* eir_flags */ + \
+				1 /* spr_how */ + \
+				  /* max is SP4_MACH_CRED (for now) */ + \
+				1 + NFS4_OP_MAP_NUM_WORDS + \
+				1 + NFS4_OP_MAP_NUM_WORDS + \
+				2 /* eir_server_owner.so_minor_id */ + \
+				/* eir_server_owner.so_major_id<> */ \
+				XDR_QUADLEN(NFS4_OPAQUE_LIMIT) + 1 + \
+				/* eir_server_scope<> */ \
+				XDR_QUADLEN(NFS4_OPAQUE_LIMIT) + 1 + \
+				1 /* eir_server_impl_id array length */ + \
+				1 /* nii_domain */ + \
+				XDR_QUADLEN(NFS4_OPAQUE_LIMIT) + \
+				1 /* nii_name */ + \
+				XDR_QUADLEN(NFS4_OPAQUE_LIMIT) + \
+				3 /* nii_date */)
+#define encode_channel_attrs_maxsz  (6 + 1 /* ca_rdma_ird.len (0) */)
+#define decode_channel_attrs_maxsz  (6 + \
+				     1 /* ca_rdma_ird.len */ + \
+				     1 /* ca_rdma_ird */)
+#define encode_create_session_maxsz  (op_encode_hdr_maxsz + \
+				     2 /* csa_clientid */ + \
+				     1 /* csa_sequence */ + \
+				     1 /* csa_flags */ + \
+				     encode_channel_attrs_maxsz + \
+				     encode_channel_attrs_maxsz + \
+				     1 /* csa_cb_program */ + \
+				     1 /* csa_sec_parms.len (1) */ + \
+				     1 /* cb_secflavor (AUTH_SYS) */ + \
+				     1 /* stamp */ + \
+				     1 /* machinename.len */ + \
+				     XDR_QUADLEN(NFS4_MAX_MACHINE_NAME_LEN) + \
+				     1 /* uid */ + \
+				     1 /* gid */ + \
+				     1 /* gids.len (0) */)
+#define decode_create_session_maxsz  (op_decode_hdr_maxsz +	\
+				     XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN) + \
+				     1 /* csr_sequence */ + \
+				     1 /* csr_flags */ + \
+				     decode_channel_attrs_maxsz + \
+				     decode_channel_attrs_maxsz)
+#define encode_bind_conn_to_session_maxsz  (op_encode_hdr_maxsz + \
+				     /* bctsa_sessid */ \
+				     XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN) + \
+				     1 /* bctsa_dir */ + \
+				     1 /* bctsa_use_conn_in_rdma_mode */)
+#define decode_bind_conn_to_session_maxsz  (op_decode_hdr_maxsz +	\
+				     /* bctsr_sessid */ \
+				     XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN) + \
+				     1 /* bctsr_dir */ + \
+				     1 /* bctsr_use_conn_in_rdma_mode */)
+#define encode_destroy_session_maxsz    (op_encode_hdr_maxsz + 4)
+#define decode_destroy_session_maxsz    (op_decode_hdr_maxsz)
+#define encode_destroy_clientid_maxsz   (op_encode_hdr_maxsz + 2)
+#define decode_destroy_clientid_maxsz   (op_decode_hdr_maxsz)
+#define encode_sequence_maxsz	(op_encode_hdr_maxsz + \
+				XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN) + 4)
+#define decode_sequence_maxsz	(op_decode_hdr_maxsz + \
+				XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN) + 5)
+#define encode_reclaim_complete_maxsz	(op_encode_hdr_maxsz + 4)
+#define decode_reclaim_complete_maxsz	(op_decode_hdr_maxsz + 4)
+#define encode_getdeviceinfo_maxsz (op_encode_hdr_maxsz + \
+				XDR_QUADLEN(NFS4_DEVICEID4_SIZE) + \
+				1 /* layout type */ + \
+				1 /* maxcount */ + \
+				1 /* bitmap size */ + \
+				1 /* notification bitmap length */ + \
+				1 /* notification bitmap, word 0 */)
+#define decode_getdeviceinfo_maxsz (op_decode_hdr_maxsz + \
+				1 /* layout type */ + \
+				1 /* opaque devaddr4 length */ + \
+				  /* devaddr4 payload is read into page */ \
+				1 /* notification bitmap length */ + \
+				1 /* notification bitmap, word 0 */ + \
+				1 /* possible XDR padding */)
+#define encode_layoutget_maxsz	(op_encode_hdr_maxsz + 10 + \
+				encode_stateid_maxsz)
+#define decode_layoutget_maxsz	(op_decode_hdr_maxsz + 8 + \
+				decode_stateid_maxsz + \
+				XDR_QUADLEN(PNFS_LAYOUT_MAXSIZE) + 1)
+#define encode_layoutcommit_maxsz (op_encode_hdr_maxsz +          \
+				2 /* offset */ + \
+				2 /* length */ + \
+				1 /* reclaim */ + \
+				encode_stateid_maxsz + \
+				1 /* new offset (true) */ + \
+				2 /* last byte written */ + \
+				1 /* nt_timechanged (false) */ + \
+				1 /* layoutupdate4 layout type */ + \
+				1 /* layoutupdate4 opaqueue len */)
+				  /* the actual content of layoutupdate4 should
+				     be allocated by drivers and spliced in
+				     using xdr_write_pages */
+#define decode_layoutcommit_maxsz (op_decode_hdr_maxsz + 3)
+#define encode_layoutreturn_maxsz (8 + op_encode_hdr_maxsz + \
+				encode_stateid_maxsz + \
+				1 + \
+				XDR_QUADLEN(NFS4_OPAQUE_LIMIT))
+#define decode_layoutreturn_maxsz (op_decode_hdr_maxsz + \
+				1 + decode_stateid_maxsz)
+#define encode_secinfo_no_name_maxsz (op_encode_hdr_maxsz + 1)
+#define decode_secinfo_no_name_maxsz decode_secinfo_maxsz
+#define encode_test_stateid_maxsz	(op_encode_hdr_maxsz + 2 + \
+					 XDR_QUADLEN(NFS4_STATEID_SIZE))
+#define decode_test_stateid_maxsz	(op_decode_hdr_maxsz + 2 + 1)
+#define encode_free_stateid_maxsz	(op_encode_hdr_maxsz + 1 + \
+					 XDR_QUADLEN(NFS4_STATEID_SIZE))
+#define decode_free_stateid_maxsz	(op_decode_hdr_maxsz)
+#else /* CONFIG_NFS_V4_1 */
+#define encode_sequence_maxsz	0
+#define decode_sequence_maxsz	0
+#define encode_layoutreturn_maxsz 0
+#define decode_layoutreturn_maxsz 0
+#define encode_layoutget_maxsz	0
+#define decode_layoutget_maxsz	0
+#endif /* CONFIG_NFS_V4_1 */
+
+#define NFS4_enc_compound_sz	(1024)  /* XXX: large enough? */
+#define NFS4_dec_compound_sz	(1024)  /* XXX: large enough? */
+#define NFS4_enc_read_sz	(compound_encode_hdr_maxsz + \
+				encode_sequence_maxsz + \
+				encode_putfh_maxsz + \
+				encode_read_maxsz)
+#define NFS4_dec_read_sz	(compound_decode_hdr_maxsz + \
+				decode_sequence_maxsz + \
+				decode_putfh_maxsz + \
+				decode_read_maxsz)
+#define NFS4_enc_readlink_sz	(compound_encode_hdr_maxsz + \
+				encode_sequence_maxsz + \
+				encode_putfh_maxsz + \
+				encode_readlink_maxsz)
+#define NFS4_dec_readlink_sz	(compound_decode_hdr_maxsz + \
+				decode_sequence_maxsz + \
+				decode_putfh_maxsz + \
+				decode_readlink_maxsz)
+#define NFS4_enc_readdir_sz	(compound_encode_hdr_maxsz + \
+				encode_sequence_maxsz + \
+				encode_putfh_maxsz + \
+				encode_readdir_maxsz)
+#define NFS4_dec_readdir_sz	(compound_decode_hdr_maxsz + \
+				decode_sequence_maxsz + \
+				decode_putfh_maxsz + \
+				decode_readdir_maxsz)
+#define NFS4_enc_write_sz	(compound_encode_hdr_maxsz + \
+				encode_sequence_maxsz + \
+				encode_putfh_maxsz + \
+				encode_write_maxsz + \
+				encode_getattr_maxsz)
+#define NFS4_dec_write_sz	(compound_decode_hdr_maxsz + \
+				decode_sequence_maxsz + \
+				decode_putfh_maxsz + \
+				decode_write_maxsz + \
+				decode_getattr_maxsz)
+#define NFS4_enc_commit_sz	(compound_encode_hdr_maxsz + \
+				encode_sequence_maxsz + \
+				encode_putfh_maxsz + \
+				encode_commit_maxsz)
+#define NFS4_dec_commit_sz	(compound_decode_hdr_maxsz + \
+				decode_sequence_maxsz + \
+				decode_putfh_maxsz + \
+				decode_commit_maxsz)
+#define NFS4_enc_open_sz        (compound_encode_hdr_maxsz + \
+				encode_sequence_maxsz + \
+				encode_putfh_maxsz + \
+				encode_open_maxsz + \
+				encode_access_maxsz + \
+				encode_getfh_maxsz + \
+				encode_getattr_maxsz + \
+				encode_layoutget_maxsz)
+#define NFS4_dec_open_sz        (compound_decode_hdr_maxsz + \
+				decode_sequence_maxsz + \
+				decode_putfh_maxsz + \
+				decode_open_maxsz + \
+				decode_access_maxsz + \
+				decode_getfh_maxsz + \
+				decode_getattr_maxsz + \
+				decode_layoutget_maxsz)
+#define NFS4_enc_open_confirm_sz \
+				(compound_encode_hdr_maxsz + \
+				 encode_putfh_maxsz + \
+				 encode_open_confirm_maxsz)
+#define NFS4_dec_open_confirm_sz \
+				(compound_decode_hdr_maxsz + \
+				 decode_putfh_maxsz + \
+				 decode_open_confirm_maxsz)
+#define NFS4_enc_open_noattr_sz	(compound_encode_hdr_maxsz + \
+					encode_sequence_maxsz + \
+					encode_putfh_maxsz + \
+					encode_open_maxsz + \
+					encode_access_maxsz + \
+					encode_getattr_maxsz + \
+					encode_layoutget_maxsz)
+#define NFS4_dec_open_noattr_sz	(compound_decode_hdr_maxsz + \
+					decode_sequence_maxsz + \
+					decode_putfh_maxsz + \
+					decode_open_maxsz + \
+					decode_access_maxsz + \
+					decode_getattr_maxsz + \
+					decode_layoutget_maxsz)
+#define NFS4_enc_open_downgrade_sz \
+				(compound_encode_hdr_maxsz + \
+				 encode_sequence_maxsz + \
+				 encode_putfh_maxsz + \
+				 encode_layoutreturn_maxsz + \
+				 encode_open_downgrade_maxsz)
+#define NFS4_dec_open_downgrade_sz \
+				(compound_decode_hdr_maxsz + \
+				 decode_sequence_maxsz + \
+				 decode_putfh_maxsz + \
+				 decode_layoutreturn_maxsz + \
+				 decode_open_downgrade_maxsz)
+#define NFS4_enc_close_sz	(compound_encode_hdr_maxsz + \
+				 encode_sequence_maxsz + \
+				 encode_putfh_maxsz + \
+				 encode_layoutreturn_maxsz + \
+				 encode_close_maxsz + \
+				 encode_getattr_maxsz)
+#define NFS4_dec_close_sz	(compound_decode_hdr_maxsz + \
+				 decode_sequence_maxsz + \
+				 decode_putfh_maxsz + \
+				 decode_layoutreturn_maxsz + \
+				 decode_close_maxsz + \
+				 decode_getattr_maxsz)
+#define NFS4_enc_setattr_sz	(compound_encode_hdr_maxsz + \
+				 encode_sequence_maxsz + \
+				 encode_putfh_maxsz + \
+				 encode_setattr_maxsz + \
+				 encode_getattr_maxsz)
+#define NFS4_dec_setattr_sz	(compound_decode_hdr_maxsz + \
+				 decode_sequence_maxsz + \
+				 decode_putfh_maxsz + \
+				 decode_setattr_maxsz + \
+				 decode_getattr_maxsz)
+#define NFS4_enc_fsinfo_sz	(compound_encode_hdr_maxsz + \
+				encode_sequence_maxsz + \
+				encode_putfh_maxsz + \
+				encode_fsinfo_maxsz)
+#define NFS4_dec_fsinfo_sz	(compound_decode_hdr_maxsz + \
+				decode_sequence_maxsz + \
+				decode_putfh_maxsz + \
+				decode_fsinfo_maxsz)
+#define NFS4_enc_renew_sz	(compound_encode_hdr_maxsz + \
+				encode_renew_maxsz)
+#define NFS4_dec_renew_sz	(compound_decode_hdr_maxsz + \
+				decode_renew_maxsz)
+#define NFS4_enc_setclientid_sz	(compound_encode_hdr_maxsz + \
+				encode_setclientid_maxsz)
+#define NFS4_dec_setclientid_sz	(compound_decode_hdr_maxsz + \
+				decode_setclientid_maxsz)
+#define NFS4_enc_setclientid_confirm_sz \
+				(compound_encode_hdr_maxsz + \
+				encode_setclientid_confirm_maxsz)
+#define NFS4_dec_setclientid_confirm_sz \
+				(compound_decode_hdr_maxsz + \
+				decode_setclientid_confirm_maxsz)
+#define NFS4_enc_lock_sz        (compound_encode_hdr_maxsz + \
+				encode_sequence_maxsz + \
+				encode_putfh_maxsz + \
+				encode_lock_maxsz)
+#define NFS4_dec_lock_sz        (compound_decode_hdr_maxsz + \
+				decode_sequence_maxsz + \
+				decode_putfh_maxsz + \
+				decode_lock_maxsz)
+#define NFS4_enc_lockt_sz       (compound_encode_hdr_maxsz + \
+				encode_sequence_maxsz + \
+				encode_putfh_maxsz + \
+				encode_lockt_maxsz)
+#define NFS4_dec_lockt_sz       (compound_decode_hdr_maxsz + \
+				 decode_sequence_maxsz + \
+				 decode_putfh_maxsz + \
+				 decode_lockt_maxsz)
+#define NFS4_enc_locku_sz       (compound_encode_hdr_maxsz + \
+				encode_sequence_maxsz + \
+				encode_putfh_maxsz + \
+				encode_locku_maxsz)
+#define NFS4_dec_locku_sz       (compound_decode_hdr_maxsz + \
+				decode_sequence_maxsz + \
+				decode_putfh_maxsz + \
+				decode_locku_maxsz)
+#define NFS4_enc_release_lockowner_sz \
+				(compound_encode_hdr_maxsz + \
+				 encode_lockowner_maxsz)
+#define NFS4_dec_release_lockowner_sz \
+				(compound_decode_hdr_maxsz + \
+				 decode_lockowner_maxsz)
+#define NFS4_enc_access_sz	(compound_encode_hdr_maxsz + \
+				encode_sequence_maxsz + \
+				encode_putfh_maxsz + \
+				encode_access_maxsz + \
+				encode_getattr_maxsz)
+#define NFS4_dec_access_sz	(compound_decode_hdr_maxsz + \
+				decode_sequence_maxsz + \
+				decode_putfh_maxsz + \
+				decode_access_maxsz + \
+				decode_getattr_maxsz)
+#define NFS4_enc_getattr_sz	(compound_encode_hdr_maxsz + \
+				encode_sequence_maxsz + \
+				encode_putfh_maxsz + \
+				encode_getattr_maxsz + \
+				encode_renew_maxsz)
+#define NFS4_dec_getattr_sz	(compound_decode_hdr_maxsz + \
+				decode_sequence_maxsz + \
+				decode_putfh_maxsz + \
+				decode_getattr_maxsz + \
+				decode_renew_maxsz)
+#define NFS4_enc_lookup_sz	(compound_encode_hdr_maxsz + \
+				encode_sequence_maxsz + \
+				encode_putfh_maxsz + \
+				encode_lookup_maxsz + \
+				encode_getattr_maxsz + \
+				encode_getfh_maxsz)
+#define NFS4_dec_lookup_sz	(compound_decode_hdr_maxsz + \
+				decode_sequence_maxsz + \
+				decode_putfh_maxsz + \
+				decode_lookup_maxsz + \
+				decode_getattr_maxsz + \
+				decode_getfh_maxsz)
+#define NFS4_enc_lookupp_sz	(compound_encode_hdr_maxsz + \
+				encode_sequence_maxsz + \
+				encode_putfh_maxsz + \
+				encode_lookupp_maxsz + \
+				encode_getattr_maxsz + \
+				encode_getfh_maxsz)
+#define NFS4_dec_lookupp_sz	(compound_decode_hdr_maxsz + \
+				decode_sequence_maxsz + \
+				decode_putfh_maxsz + \
+				decode_lookupp_maxsz + \
+				decode_getattr_maxsz + \
+				decode_getfh_maxsz)
+#define NFS4_enc_lookup_root_sz (compound_encode_hdr_maxsz + \
+				encode_sequence_maxsz + \
+				encode_putrootfh_maxsz + \
+				encode_getattr_maxsz + \
+				encode_getfh_maxsz)
+#define NFS4_dec_lookup_root_sz (compound_decode_hdr_maxsz + \
+				decode_sequence_maxsz + \
+				decode_putrootfh_maxsz + \
+				decode_getattr_maxsz + \
+				decode_getfh_maxsz)
+#define NFS4_enc_remove_sz	(compound_encode_hdr_maxsz + \
+				encode_sequence_maxsz + \
+				encode_putfh_maxsz + \
+				encode_remove_maxsz)
+#define NFS4_dec_remove_sz	(compound_decode_hdr_maxsz + \
+				decode_sequence_maxsz + \
+				decode_putfh_maxsz + \
+				decode_remove_maxsz)
+#define NFS4_enc_rename_sz	(compound_encode_hdr_maxsz + \
+				encode_sequence_maxsz + \
+				encode_putfh_maxsz + \
+				encode_savefh_maxsz + \
+				encode_putfh_maxsz + \
+				encode_rename_maxsz)
+#define NFS4_dec_rename_sz	(compound_decode_hdr_maxsz + \
+				decode_sequence_maxsz + \
+				decode_putfh_maxsz + \
+				decode_savefh_maxsz + \
+				decode_putfh_maxsz + \
+				decode_rename_maxsz)
+#define NFS4_enc_link_sz	(compound_encode_hdr_maxsz + \
+				encode_sequence_maxsz + \
+				encode_putfh_maxsz + \
+				encode_savefh_maxsz + \
+				encode_putfh_maxsz + \
+				encode_link_maxsz + \
+				encode_restorefh_maxsz + \
+				encode_getattr_maxsz)
+#define NFS4_dec_link_sz	(compound_decode_hdr_maxsz + \
+				decode_sequence_maxsz + \
+				decode_putfh_maxsz + \
+				decode_savefh_maxsz + \
+				decode_putfh_maxsz + \
+				decode_link_maxsz + \
+				decode_restorefh_maxsz + \
+				decode_getattr_maxsz)
+#define NFS4_enc_symlink_sz	(compound_encode_hdr_maxsz + \
+				encode_sequence_maxsz + \
+				encode_putfh_maxsz + \
+				encode_symlink_maxsz + \
+				encode_getattr_maxsz + \
+				encode_getfh_maxsz)
+#define NFS4_dec_symlink_sz	(compound_decode_hdr_maxsz + \
+				decode_sequence_maxsz + \
+				decode_putfh_maxsz + \
+				decode_symlink_maxsz + \
+				decode_getattr_maxsz + \
+				decode_getfh_maxsz)
+#define NFS4_enc_create_sz	(compound_encode_hdr_maxsz + \
+				encode_sequence_maxsz + \
+				encode_putfh_maxsz + \
+				encode_create_maxsz + \
+				encode_getfh_maxsz + \
+				encode_getattr_maxsz)
+#define NFS4_dec_create_sz	(compound_decode_hdr_maxsz + \
+				decode_sequence_maxsz + \
+				decode_putfh_maxsz + \
+				decode_create_maxsz + \
+				decode_getfh_maxsz + \
+				decode_getattr_maxsz)
+#define NFS4_enc_pathconf_sz	(compound_encode_hdr_maxsz + \
+				encode_sequence_maxsz + \
+				encode_putfh_maxsz + \
+				encode_getattr_maxsz)
+#define NFS4_dec_pathconf_sz	(compound_decode_hdr_maxsz + \
+				decode_sequence_maxsz + \
+				decode_putfh_maxsz + \
+				decode_getattr_maxsz)
+#define NFS4_enc_statfs_sz	(compound_encode_hdr_maxsz + \
+				encode_sequence_maxsz + \
+				encode_putfh_maxsz + \
+				encode_statfs_maxsz)
+#define NFS4_dec_statfs_sz	(compound_decode_hdr_maxsz + \
+				decode_sequence_maxsz + \
+				decode_putfh_maxsz + \
+				decode_statfs_maxsz)
+#define NFS4_enc_server_caps_sz (compound_encode_hdr_maxsz + \
+				encode_sequence_maxsz + \
+				encode_putfh_maxsz + \
+				encode_getattr_maxsz)
+#define NFS4_dec_server_caps_sz (compound_decode_hdr_maxsz + \
+				decode_sequence_maxsz + \
+				decode_putfh_maxsz + \
+				decode_getattr_maxsz)
+#define NFS4_enc_delegreturn_sz	(compound_encode_hdr_maxsz + \
+				encode_sequence_maxsz + \
+				encode_putfh_maxsz + \
+				encode_layoutreturn_maxsz + \
+				encode_delegreturn_maxsz + \
+				encode_getattr_maxsz)
+#define NFS4_dec_delegreturn_sz (compound_decode_hdr_maxsz + \
+				decode_sequence_maxsz + \
+				decode_putfh_maxsz + \
+				decode_layoutreturn_maxsz + \
+				decode_delegreturn_maxsz + \
+				decode_getattr_maxsz)
+#define NFS4_enc_getacl_sz	(compound_encode_hdr_maxsz + \
+				encode_sequence_maxsz + \
+				encode_putfh_maxsz + \
+				encode_getacl_maxsz)
+#define NFS4_dec_getacl_sz	(compound_decode_hdr_maxsz + \
+				decode_sequence_maxsz + \
+				decode_putfh_maxsz + \
+				decode_getacl_maxsz)
+#define NFS4_enc_setacl_sz	(compound_encode_hdr_maxsz + \
+				encode_sequence_maxsz + \
+				encode_putfh_maxsz + \
+				encode_setacl_maxsz)
+#define NFS4_dec_setacl_sz	(compound_decode_hdr_maxsz + \
+				decode_sequence_maxsz + \
+				decode_putfh_maxsz + \
+				decode_setacl_maxsz)
+#define NFS4_enc_fs_locations_sz \
+				(compound_encode_hdr_maxsz + \
+				 encode_sequence_maxsz + \
+				 encode_putfh_maxsz + \
+				 encode_lookup_maxsz + \
+				 encode_fs_locations_maxsz + \
+				 encode_renew_maxsz)
+#define NFS4_dec_fs_locations_sz \
+				(compound_decode_hdr_maxsz + \
+				 decode_sequence_maxsz + \
+				 decode_putfh_maxsz + \
+				 decode_lookup_maxsz + \
+				 decode_fs_locations_maxsz + \
+				 decode_renew_maxsz)
+#define NFS4_enc_secinfo_sz 	(compound_encode_hdr_maxsz + \
+				encode_sequence_maxsz + \
+				encode_putfh_maxsz + \
+				encode_secinfo_maxsz)
+#define NFS4_dec_secinfo_sz	(compound_decode_hdr_maxsz + \
+				decode_sequence_maxsz + \
+				decode_putfh_maxsz + \
+				decode_secinfo_maxsz)
+#define NFS4_enc_fsid_present_sz \
+				(compound_encode_hdr_maxsz + \
+				 encode_sequence_maxsz + \
+				 encode_putfh_maxsz + \
+				 encode_getfh_maxsz + \
+				 encode_renew_maxsz)
+#define NFS4_dec_fsid_present_sz \
+				(compound_decode_hdr_maxsz + \
+				 decode_sequence_maxsz + \
+				 decode_putfh_maxsz + \
+				 decode_getfh_maxsz + \
+				 decode_renew_maxsz)
+#if defined(CONFIG_NFS_V4_1)
+#define NFS4_enc_bind_conn_to_session_sz \
+				(compound_encode_hdr_maxsz + \
+				 encode_bind_conn_to_session_maxsz)
+#define NFS4_dec_bind_conn_to_session_sz \
+				(compound_decode_hdr_maxsz + \
+				 decode_bind_conn_to_session_maxsz)
+#define NFS4_enc_exchange_id_sz \
+				(compound_encode_hdr_maxsz + \
+				 encode_exchange_id_maxsz)
+#define NFS4_dec_exchange_id_sz \
+				(compound_decode_hdr_maxsz + \
+				 decode_exchange_id_maxsz)
+#define NFS4_enc_create_session_sz \
+				(compound_encode_hdr_maxsz + \
+				 encode_create_session_maxsz)
+#define NFS4_dec_create_session_sz \
+				(compound_decode_hdr_maxsz + \
+				 decode_create_session_maxsz)
+#define NFS4_enc_destroy_session_sz	(compound_encode_hdr_maxsz + \
+					 encode_destroy_session_maxsz)
+#define NFS4_dec_destroy_session_sz	(compound_decode_hdr_maxsz + \
+					 decode_destroy_session_maxsz)
+#define NFS4_enc_destroy_clientid_sz	(compound_encode_hdr_maxsz + \
+					 encode_destroy_clientid_maxsz)
+#define NFS4_dec_destroy_clientid_sz	(compound_decode_hdr_maxsz + \
+					 decode_destroy_clientid_maxsz)
+#define NFS4_enc_sequence_sz \
+				(compound_decode_hdr_maxsz + \
+				 encode_sequence_maxsz)
+#define NFS4_dec_sequence_sz \
+				(compound_decode_hdr_maxsz + \
+				 decode_sequence_maxsz)
+#endif
+#define NFS4_enc_get_lease_time_sz	(compound_encode_hdr_maxsz + \
+					 encode_sequence_maxsz + \
+					 encode_putrootfh_maxsz + \
+					 encode_fsinfo_maxsz)
+#define NFS4_dec_get_lease_time_sz	(compound_decode_hdr_maxsz + \
+					 decode_sequence_maxsz + \
+					 decode_putrootfh_maxsz + \
+					 decode_fsinfo_maxsz)
+#if defined(CONFIG_NFS_V4_1)
+#define NFS4_enc_reclaim_complete_sz	(compound_encode_hdr_maxsz + \
+					 encode_sequence_maxsz + \
+					 encode_reclaim_complete_maxsz)
+#define NFS4_dec_reclaim_complete_sz	(compound_decode_hdr_maxsz + \
+					 decode_sequence_maxsz + \
+					 decode_reclaim_complete_maxsz)
+#define NFS4_enc_getdeviceinfo_sz (compound_encode_hdr_maxsz +    \
+				encode_sequence_maxsz +\
+				encode_getdeviceinfo_maxsz)
+#define NFS4_dec_getdeviceinfo_sz (compound_decode_hdr_maxsz +    \
+				decode_sequence_maxsz + \
+				decode_getdeviceinfo_maxsz)
+#define NFS4_enc_layoutget_sz	(compound_encode_hdr_maxsz + \
+				encode_sequence_maxsz + \
+				encode_putfh_maxsz +        \
+				encode_layoutget_maxsz)
+#define NFS4_dec_layoutget_sz	(compound_decode_hdr_maxsz + \
+				decode_sequence_maxsz + \
+				decode_putfh_maxsz +        \
+				decode_layoutget_maxsz)
+#define NFS4_enc_layoutcommit_sz (compound_encode_hdr_maxsz + \
+				encode_sequence_maxsz +\
+				encode_putfh_maxsz + \
+				encode_layoutcommit_maxsz + \
+				encode_getattr_maxsz)
+#define NFS4_dec_layoutcommit_sz (compound_decode_hdr_maxsz + \
+				decode_sequence_maxsz + \
+				decode_putfh_maxsz + \
+				decode_layoutcommit_maxsz + \
+				decode_getattr_maxsz)
+#define NFS4_enc_layoutreturn_sz (compound_encode_hdr_maxsz + \
+				encode_sequence_maxsz + \
+				encode_putfh_maxsz + \
+				encode_layoutreturn_maxsz)
+#define NFS4_dec_layoutreturn_sz (compound_decode_hdr_maxsz + \
+				decode_sequence_maxsz + \
+				decode_putfh_maxsz + \
+				decode_layoutreturn_maxsz)
+#define NFS4_enc_secinfo_no_name_sz	(compound_encode_hdr_maxsz + \
+					encode_sequence_maxsz + \
+					encode_putrootfh_maxsz +\
+					encode_secinfo_no_name_maxsz)
+#define NFS4_dec_secinfo_no_name_sz	(compound_decode_hdr_maxsz + \
+					decode_sequence_maxsz + \
+					decode_putrootfh_maxsz + \
+					decode_secinfo_no_name_maxsz)
+#define NFS4_enc_test_stateid_sz	(compound_encode_hdr_maxsz + \
+					 encode_sequence_maxsz + \
+					 encode_test_stateid_maxsz)
+#define NFS4_dec_test_stateid_sz	(compound_decode_hdr_maxsz + \
+					 decode_sequence_maxsz + \
+					 decode_test_stateid_maxsz)
+#define NFS4_enc_free_stateid_sz	(compound_encode_hdr_maxsz + \
+					 encode_sequence_maxsz + \
+					 encode_free_stateid_maxsz)
+#define NFS4_dec_free_stateid_sz	(compound_decode_hdr_maxsz + \
+					 decode_sequence_maxsz + \
+					 decode_free_stateid_maxsz)
+
+const u32 nfs41_maxwrite_overhead = ((RPC_MAX_HEADER_WITH_AUTH +
+				      compound_encode_hdr_maxsz +
+				      encode_sequence_maxsz +
+				      encode_putfh_maxsz +
+				      encode_getattr_maxsz) *
+				     XDR_UNIT);
+
+const u32 nfs41_maxread_overhead = ((RPC_MAX_HEADER_WITH_AUTH +
+				     compound_decode_hdr_maxsz +
+				     decode_sequence_maxsz +
+				     decode_putfh_maxsz) *
+				    XDR_UNIT);
+
+const u32 nfs41_maxgetdevinfo_overhead = ((RPC_MAX_REPHEADER_WITH_AUTH +
+					   compound_decode_hdr_maxsz +
+					   decode_sequence_maxsz) *
+					  XDR_UNIT);
+EXPORT_SYMBOL_GPL(nfs41_maxgetdevinfo_overhead);
+#endif /* CONFIG_NFS_V4_1 */
+
+static const umode_t nfs_type2fmt[] = {
+	[NF4BAD] = 0,
+	[NF4REG] = S_IFREG,
+	[NF4DIR] = S_IFDIR,
+	[NF4BLK] = S_IFBLK,
+	[NF4CHR] = S_IFCHR,
+	[NF4LNK] = S_IFLNK,
+	[NF4SOCK] = S_IFSOCK,
+	[NF4FIFO] = S_IFIFO,
+	[NF4ATTRDIR] = 0,
+	[NF4NAMEDATTR] = 0,
+};
+
+struct compound_hdr {
+	int32_t		status;
+	uint32_t	nops;
+	__be32 *	nops_p;
+	uint32_t	taglen;
+	char *		tag;
+	uint32_t	replen;		/* expected reply words */
+	u32		minorversion;
+};
+
+static __be32 *reserve_space(struct xdr_stream *xdr, size_t nbytes)
+{
+	__be32 *p = xdr_reserve_space(xdr, nbytes);
+	BUG_ON(!p);
+	return p;
+}
+
+static void encode_opaque_fixed(struct xdr_stream *xdr, const void *buf, size_t len)
+{
+	WARN_ON_ONCE(xdr_stream_encode_opaque_fixed(xdr, buf, len) < 0);
+}
+
+static void encode_string(struct xdr_stream *xdr, unsigned int len, const char *str)
+{
+	WARN_ON_ONCE(xdr_stream_encode_opaque(xdr, str, len) < 0);
+}
+
+static void encode_uint32(struct xdr_stream *xdr, u32 n)
+{
+	WARN_ON_ONCE(xdr_stream_encode_u32(xdr, n) < 0);
+}
+
+static void encode_uint64(struct xdr_stream *xdr, u64 n)
+{
+	WARN_ON_ONCE(xdr_stream_encode_u64(xdr, n) < 0);
+}
+
+static ssize_t xdr_encode_bitmap4(struct xdr_stream *xdr,
+		const __u32 *bitmap, size_t len)
+{
+	ssize_t ret;
+
+	/* Trim empty words */
+	while (len > 0 && bitmap[len-1] == 0)
+		len--;
+	ret = xdr_stream_encode_uint32_array(xdr, bitmap, len);
+	if (WARN_ON_ONCE(ret < 0))
+		return ret;
+	return len;
+}
+
+static size_t mask_bitmap4(const __u32 *bitmap, const __u32 *mask,
+		__u32 *res, size_t len)
+{
+	size_t i;
+	__u32 tmp;
+
+	while (len > 0 && (bitmap[len-1] == 0 || mask[len-1] == 0))
+		len--;
+	for (i = len; i-- > 0;) {
+		tmp = bitmap[i] & mask[i];
+		res[i] = tmp;
+	}
+	return len;
+}
+
+static void encode_nfs4_seqid(struct xdr_stream *xdr,
+		const struct nfs_seqid *seqid)
+{
+	if (seqid != NULL)
+		encode_uint32(xdr, seqid->sequence->counter);
+	else
+		encode_uint32(xdr, 0);
+}
+
+static void encode_compound_hdr(struct xdr_stream *xdr,
+				struct rpc_rqst *req,
+				struct compound_hdr *hdr)
+{
+	__be32 *p;
+
+	/* initialize running count of expected bytes in reply.
+	 * NOTE: the replied tag SHOULD be the same is the one sent,
+	 * but this is not required as a MUST for the server to do so. */
+	hdr->replen = 3 + hdr->taglen;
+
+	WARN_ON_ONCE(hdr->taglen > NFS4_MAXTAGLEN);
+	encode_string(xdr, hdr->taglen, hdr->tag);
+	p = reserve_space(xdr, 8);
+	*p++ = cpu_to_be32(hdr->minorversion);
+	hdr->nops_p = p;
+	*p = cpu_to_be32(hdr->nops);
+}
+
+static void encode_op_hdr(struct xdr_stream *xdr, enum nfs_opnum4 op,
+		uint32_t replen,
+		struct compound_hdr *hdr)
+{
+	encode_uint32(xdr, op);
+	hdr->nops++;
+	hdr->replen += replen;
+}
+
+static void encode_nops(struct compound_hdr *hdr)
+{
+	WARN_ON_ONCE(hdr->nops > NFS4_MAX_OPS);
+	*hdr->nops_p = htonl(hdr->nops);
+}
+
+static void encode_nfs4_stateid(struct xdr_stream *xdr, const nfs4_stateid *stateid)
+{
+	encode_opaque_fixed(xdr, stateid, NFS4_STATEID_SIZE);
+}
+
+static void encode_nfs4_verifier(struct xdr_stream *xdr, const nfs4_verifier *verf)
+{
+	encode_opaque_fixed(xdr, verf->data, NFS4_VERIFIER_SIZE);
+}
+
+static __be32 *
+xdr_encode_nfstime4(__be32 *p, const struct timespec64 *t)
+{
+	p = xdr_encode_hyper(p, t->tv_sec);
+	*p++ = cpu_to_be32(t->tv_nsec);
+	return p;
+}
+
+static void encode_attrs(struct xdr_stream *xdr, const struct iattr *iap,
+				const struct nfs4_label *label,
+				const umode_t *umask,
+				const struct nfs_server *server,
+				const uint32_t attrmask[])
+{
+	char owner_name[IDMAP_NAMESZ];
+	char owner_group[IDMAP_NAMESZ];
+	int owner_namelen = 0;
+	int owner_grouplen = 0;
+	__be32 *p;
+	uint32_t len = 0;
+	uint32_t bmval[3] = { 0 };
+
+	/*
+	 * We reserve enough space to write the entire attribute buffer at once.
+	 */
+	if ((iap->ia_valid & ATTR_SIZE) && (attrmask[0] & FATTR4_WORD0_SIZE)) {
+		bmval[0] |= FATTR4_WORD0_SIZE;
+		len += 8;
+	}
+	if (iap->ia_valid & ATTR_MODE) {
+		if (umask && (attrmask[2] & FATTR4_WORD2_MODE_UMASK)) {
+			bmval[2] |= FATTR4_WORD2_MODE_UMASK;
+			len += 8;
+		} else if (attrmask[1] & FATTR4_WORD1_MODE) {
+			bmval[1] |= FATTR4_WORD1_MODE;
+			len += 4;
+		}
+	}
+	if ((iap->ia_valid & ATTR_UID) && (attrmask[1] & FATTR4_WORD1_OWNER)) {
+		owner_namelen = nfs_map_uid_to_name(server, iap->ia_uid, owner_name, IDMAP_NAMESZ);
+		if (owner_namelen < 0) {
+			dprintk("nfs: couldn't resolve uid %d to string\n",
+					from_kuid(&init_user_ns, iap->ia_uid));
+			/* XXX */
+			strcpy(owner_name, "nobody");
+			owner_namelen = sizeof("nobody") - 1;
+			/* goto out; */
+		}
+		bmval[1] |= FATTR4_WORD1_OWNER;
+		len += 4 + (XDR_QUADLEN(owner_namelen) << 2);
+	}
+	if ((iap->ia_valid & ATTR_GID) &&
+	   (attrmask[1] & FATTR4_WORD1_OWNER_GROUP)) {
+		owner_grouplen = nfs_map_gid_to_group(server, iap->ia_gid, owner_group, IDMAP_NAMESZ);
+		if (owner_grouplen < 0) {
+			dprintk("nfs: couldn't resolve gid %d to string\n",
+					from_kgid(&init_user_ns, iap->ia_gid));
+			strcpy(owner_group, "nobody");
+			owner_grouplen = sizeof("nobody") - 1;
+			/* goto out; */
+		}
+		bmval[1] |= FATTR4_WORD1_OWNER_GROUP;
+		len += 4 + (XDR_QUADLEN(owner_grouplen) << 2);
+	}
+	if (attrmask[1] & FATTR4_WORD1_TIME_ACCESS_SET) {
+		if (iap->ia_valid & ATTR_ATIME_SET) {
+			bmval[1] |= FATTR4_WORD1_TIME_ACCESS_SET;
+			len += 4 + (nfstime4_maxsz << 2);
+		} else if (iap->ia_valid & ATTR_ATIME) {
+			bmval[1] |= FATTR4_WORD1_TIME_ACCESS_SET;
+			len += 4;
+		}
+	}
+	if (attrmask[1] & FATTR4_WORD1_TIME_MODIFY_SET) {
+		if (iap->ia_valid & ATTR_MTIME_SET) {
+			bmval[1] |= FATTR4_WORD1_TIME_MODIFY_SET;
+			len += 4 + (nfstime4_maxsz << 2);
+		} else if (iap->ia_valid & ATTR_MTIME) {
+			bmval[1] |= FATTR4_WORD1_TIME_MODIFY_SET;
+			len += 4;
+		}
+	}
+
+	if (label && (attrmask[2] & FATTR4_WORD2_SECURITY_LABEL)) {
+		len += 4 + 4 + 4 + (XDR_QUADLEN(label->len) << 2);
+		bmval[2] |= FATTR4_WORD2_SECURITY_LABEL;
+	}
+
+	xdr_encode_bitmap4(xdr, bmval, ARRAY_SIZE(bmval));
+	xdr_stream_encode_opaque_inline(xdr, (void **)&p, len);
+
+	if (bmval[0] & FATTR4_WORD0_SIZE)
+		p = xdr_encode_hyper(p, iap->ia_size);
+	if (bmval[1] & FATTR4_WORD1_MODE)
+		*p++ = cpu_to_be32(iap->ia_mode & S_IALLUGO);
+	if (bmval[1] & FATTR4_WORD1_OWNER)
+		p = xdr_encode_opaque(p, owner_name, owner_namelen);
+	if (bmval[1] & FATTR4_WORD1_OWNER_GROUP)
+		p = xdr_encode_opaque(p, owner_group, owner_grouplen);
+	if (bmval[1] & FATTR4_WORD1_TIME_ACCESS_SET) {
+		if (iap->ia_valid & ATTR_ATIME_SET) {
+			*p++ = cpu_to_be32(NFS4_SET_TO_CLIENT_TIME);
+			p = xdr_encode_nfstime4(p, &iap->ia_atime);
+		} else
+			*p++ = cpu_to_be32(NFS4_SET_TO_SERVER_TIME);
+	}
+	if (bmval[1] & FATTR4_WORD1_TIME_MODIFY_SET) {
+		if (iap->ia_valid & ATTR_MTIME_SET) {
+			*p++ = cpu_to_be32(NFS4_SET_TO_CLIENT_TIME);
+			p = xdr_encode_nfstime4(p, &iap->ia_mtime);
+		} else
+			*p++ = cpu_to_be32(NFS4_SET_TO_SERVER_TIME);
+	}
+	if (label && (bmval[2] & FATTR4_WORD2_SECURITY_LABEL)) {
+		*p++ = cpu_to_be32(label->lfs);
+		*p++ = cpu_to_be32(label->pi);
+		*p++ = cpu_to_be32(label->len);
+		p = xdr_encode_opaque_fixed(p, label->label, label->len);
+	}
+	if (bmval[2] & FATTR4_WORD2_MODE_UMASK) {
+		*p++ = cpu_to_be32(iap->ia_mode & S_IALLUGO);
+		*p++ = cpu_to_be32(*umask);
+	}
+
+/* out: */
+}
+
+static void encode_access(struct xdr_stream *xdr, u32 access, struct compound_hdr *hdr)
+{
+	encode_op_hdr(xdr, OP_ACCESS, decode_access_maxsz, hdr);
+	encode_uint32(xdr, access);
+}
+
+static void encode_close(struct xdr_stream *xdr, const struct nfs_closeargs *arg, struct compound_hdr *hdr)
+{
+	encode_op_hdr(xdr, OP_CLOSE, decode_close_maxsz, hdr);
+	encode_nfs4_seqid(xdr, arg->seqid);
+	encode_nfs4_stateid(xdr, &arg->stateid);
+}
+
+static void encode_commit(struct xdr_stream *xdr, const struct nfs_commitargs *args, struct compound_hdr *hdr)
+{
+	__be32 *p;
+
+	encode_op_hdr(xdr, OP_COMMIT, decode_commit_maxsz, hdr);
+	p = reserve_space(xdr, 12);
+	p = xdr_encode_hyper(p, args->offset);
+	*p = cpu_to_be32(args->count);
+}
+
+static void encode_create(struct xdr_stream *xdr, const struct nfs4_create_arg *create, struct compound_hdr *hdr)
+{
+	__be32 *p;
+
+	encode_op_hdr(xdr, OP_CREATE, decode_create_maxsz, hdr);
+	encode_uint32(xdr, create->ftype);
+
+	switch (create->ftype) {
+	case NF4LNK:
+		p = reserve_space(xdr, 4);
+		*p = cpu_to_be32(create->u.symlink.len);
+		xdr_write_pages(xdr, create->u.symlink.pages, 0,
+				create->u.symlink.len);
+		xdr->buf->flags |= XDRBUF_WRITE;
+		break;
+
+	case NF4BLK: case NF4CHR:
+		p = reserve_space(xdr, 8);
+		*p++ = cpu_to_be32(create->u.device.specdata1);
+		*p = cpu_to_be32(create->u.device.specdata2);
+		break;
+
+	default:
+		break;
+	}
+
+	encode_string(xdr, create->name->len, create->name->name);
+	encode_attrs(xdr, create->attrs, create->label, &create->umask,
+			create->server, create->server->attr_bitmask);
+}
+
+static void encode_getattr(struct xdr_stream *xdr,
+		const __u32 *bitmap, const __u32 *mask, size_t len,
+		struct compound_hdr *hdr)
+{
+	__u32 masked_bitmap[nfs4_fattr_bitmap_maxsz];
+
+	encode_op_hdr(xdr, OP_GETATTR, decode_getattr_maxsz, hdr);
+	if (mask) {
+		if (WARN_ON_ONCE(len > ARRAY_SIZE(masked_bitmap)))
+			len = ARRAY_SIZE(masked_bitmap);
+		len = mask_bitmap4(bitmap, mask, masked_bitmap, len);
+		bitmap = masked_bitmap;
+	}
+	xdr_encode_bitmap4(xdr, bitmap, len);
+}
+
+static void encode_getfattr(struct xdr_stream *xdr, const u32* bitmask, struct compound_hdr *hdr)
+{
+	encode_getattr(xdr, nfs4_fattr_bitmap, bitmask,
+			ARRAY_SIZE(nfs4_fattr_bitmap), hdr);
+}
+
+static void encode_getfattr_open(struct xdr_stream *xdr, const u32 *bitmask,
+				 const u32 *open_bitmap,
+				 struct compound_hdr *hdr)
+{
+	encode_getattr(xdr, open_bitmap, bitmask, 3, hdr);
+}
+
+static void encode_fsinfo(struct xdr_stream *xdr, const u32* bitmask, struct compound_hdr *hdr)
+{
+	encode_getattr(xdr, nfs4_fsinfo_bitmap, bitmask,
+			ARRAY_SIZE(nfs4_fsinfo_bitmap), hdr);
+}
+
+static void encode_fs_locations(struct xdr_stream *xdr, const u32* bitmask, struct compound_hdr *hdr)
+{
+	encode_getattr(xdr, nfs4_fs_locations_bitmap, bitmask,
+			ARRAY_SIZE(nfs4_fs_locations_bitmap), hdr);
+}
+
+static void encode_getfh(struct xdr_stream *xdr, struct compound_hdr *hdr)
+{
+	encode_op_hdr(xdr, OP_GETFH, decode_getfh_maxsz, hdr);
+}
+
+static void encode_link(struct xdr_stream *xdr, const struct qstr *name, struct compound_hdr *hdr)
+{
+	encode_op_hdr(xdr, OP_LINK, decode_link_maxsz, hdr);
+	encode_string(xdr, name->len, name->name);
+}
+
+static inline int nfs4_lock_type(struct file_lock *fl, int block)
+{
+	if (fl->fl_type == F_RDLCK)
+		return block ? NFS4_READW_LT : NFS4_READ_LT;
+	return block ? NFS4_WRITEW_LT : NFS4_WRITE_LT;
+}
+
+static inline uint64_t nfs4_lock_length(struct file_lock *fl)
+{
+	if (fl->fl_end == OFFSET_MAX)
+		return ~(uint64_t)0;
+	return fl->fl_end - fl->fl_start + 1;
+}
+
+static void encode_lockowner(struct xdr_stream *xdr, const struct nfs_lowner *lowner)
+{
+	__be32 *p;
+
+	p = reserve_space(xdr, 32);
+	p = xdr_encode_hyper(p, lowner->clientid);
+	*p++ = cpu_to_be32(20);
+	p = xdr_encode_opaque_fixed(p, "lock id:", 8);
+	*p++ = cpu_to_be32(lowner->s_dev);
+	xdr_encode_hyper(p, lowner->id);
+}
+
+/*
+ * opcode,type,reclaim,offset,length,new_lock_owner = 32
+ * open_seqid,open_stateid,lock_seqid,lock_owner.clientid, lock_owner.id = 40
+ */
+static void encode_lock(struct xdr_stream *xdr, const struct nfs_lock_args *args, struct compound_hdr *hdr)
+{
+	__be32 *p;
+
+	encode_op_hdr(xdr, OP_LOCK, decode_lock_maxsz, hdr);
+	p = reserve_space(xdr, 28);
+	*p++ = cpu_to_be32(nfs4_lock_type(args->fl, args->block));
+	*p++ = cpu_to_be32(args->reclaim);
+	p = xdr_encode_hyper(p, args->fl->fl_start);
+	p = xdr_encode_hyper(p, nfs4_lock_length(args->fl));
+	*p = cpu_to_be32(args->new_lock_owner);
+	if (args->new_lock_owner){
+		encode_nfs4_seqid(xdr, args->open_seqid);
+		encode_nfs4_stateid(xdr, &args->open_stateid);
+		encode_nfs4_seqid(xdr, args->lock_seqid);
+		encode_lockowner(xdr, &args->lock_owner);
+	}
+	else {
+		encode_nfs4_stateid(xdr, &args->lock_stateid);
+		encode_nfs4_seqid(xdr, args->lock_seqid);
+	}
+}
+
+static void encode_lockt(struct xdr_stream *xdr, const struct nfs_lockt_args *args, struct compound_hdr *hdr)
+{
+	__be32 *p;
+
+	encode_op_hdr(xdr, OP_LOCKT, decode_lockt_maxsz, hdr);
+	p = reserve_space(xdr, 20);
+	*p++ = cpu_to_be32(nfs4_lock_type(args->fl, 0));
+	p = xdr_encode_hyper(p, args->fl->fl_start);
+	p = xdr_encode_hyper(p, nfs4_lock_length(args->fl));
+	encode_lockowner(xdr, &args->lock_owner);
+}
+
+static void encode_locku(struct xdr_stream *xdr, const struct nfs_locku_args *args, struct compound_hdr *hdr)
+{
+	__be32 *p;
+
+	encode_op_hdr(xdr, OP_LOCKU, decode_locku_maxsz, hdr);
+	encode_uint32(xdr, nfs4_lock_type(args->fl, 0));
+	encode_nfs4_seqid(xdr, args->seqid);
+	encode_nfs4_stateid(xdr, &args->stateid);
+	p = reserve_space(xdr, 16);
+	p = xdr_encode_hyper(p, args->fl->fl_start);
+	xdr_encode_hyper(p, nfs4_lock_length(args->fl));
+}
+
+static void encode_release_lockowner(struct xdr_stream *xdr, const struct nfs_lowner *lowner, struct compound_hdr *hdr)
+{
+	encode_op_hdr(xdr, OP_RELEASE_LOCKOWNER, decode_release_lockowner_maxsz, hdr);
+	encode_lockowner(xdr, lowner);
+}
+
+static void encode_lookup(struct xdr_stream *xdr, const struct qstr *name, struct compound_hdr *hdr)
+{
+	encode_op_hdr(xdr, OP_LOOKUP, decode_lookup_maxsz, hdr);
+	encode_string(xdr, name->len, name->name);
+}
+
+static void encode_lookupp(struct xdr_stream *xdr, struct compound_hdr *hdr)
+{
+	encode_op_hdr(xdr, OP_LOOKUPP, decode_lookupp_maxsz, hdr);
+}
+
+static void encode_share_access(struct xdr_stream *xdr, u32 share_access)
+{
+	__be32 *p;
+
+	p = reserve_space(xdr, 8);
+	*p++ = cpu_to_be32(share_access);
+	*p = cpu_to_be32(0);		/* for linux, share_deny = 0 always */
+}
+
+static inline void encode_openhdr(struct xdr_stream *xdr, const struct nfs_openargs *arg)
+{
+	__be32 *p;
+ /*
+ * opcode 4, seqid 4, share_access 4, share_deny 4, clientid 8, ownerlen 4,
+ * owner 4 = 32
+ */
+	encode_nfs4_seqid(xdr, arg->seqid);
+	encode_share_access(xdr, arg->share_access);
+	p = reserve_space(xdr, 36);
+	p = xdr_encode_hyper(p, arg->clientid);
+	*p++ = cpu_to_be32(24);
+	p = xdr_encode_opaque_fixed(p, "open id:", 8);
+	*p++ = cpu_to_be32(arg->server->s_dev);
+	*p++ = cpu_to_be32(arg->id.uniquifier);
+	xdr_encode_hyper(p, arg->id.create_time);
+}
+
+static inline void encode_createmode(struct xdr_stream *xdr, const struct nfs_openargs *arg)
+{
+	__be32 *p;
+
+	p = reserve_space(xdr, 4);
+	switch(arg->createmode) {
+	case NFS4_CREATE_UNCHECKED:
+		*p = cpu_to_be32(NFS4_CREATE_UNCHECKED);
+		encode_attrs(xdr, arg->u.attrs, arg->label, &arg->umask,
+				arg->server, arg->server->attr_bitmask);
+		break;
+	case NFS4_CREATE_GUARDED:
+		*p = cpu_to_be32(NFS4_CREATE_GUARDED);
+		encode_attrs(xdr, arg->u.attrs, arg->label, &arg->umask,
+				arg->server, arg->server->attr_bitmask);
+		break;
+	case NFS4_CREATE_EXCLUSIVE:
+		*p = cpu_to_be32(NFS4_CREATE_EXCLUSIVE);
+		encode_nfs4_verifier(xdr, &arg->u.verifier);
+		break;
+	case NFS4_CREATE_EXCLUSIVE4_1:
+		*p = cpu_to_be32(NFS4_CREATE_EXCLUSIVE4_1);
+		encode_nfs4_verifier(xdr, &arg->u.verifier);
+		encode_attrs(xdr, arg->u.attrs, arg->label, &arg->umask,
+				arg->server, arg->server->exclcreat_bitmask);
+	}
+}
+
+static void encode_opentype(struct xdr_stream *xdr, const struct nfs_openargs *arg)
+{
+	__be32 *p;
+
+	p = reserve_space(xdr, 4);
+	switch (arg->open_flags & O_CREAT) {
+	case 0:
+		*p = cpu_to_be32(NFS4_OPEN_NOCREATE);
+		break;
+	default:
+		*p = cpu_to_be32(NFS4_OPEN_CREATE);
+		encode_createmode(xdr, arg);
+	}
+}
+
+static inline void encode_delegation_type(struct xdr_stream *xdr, fmode_t delegation_type)
+{
+	__be32 *p;
+
+	p = reserve_space(xdr, 4);
+	switch (delegation_type) {
+	case 0:
+		*p = cpu_to_be32(NFS4_OPEN_DELEGATE_NONE);
+		break;
+	case FMODE_READ:
+		*p = cpu_to_be32(NFS4_OPEN_DELEGATE_READ);
+		break;
+	case FMODE_WRITE|FMODE_READ:
+		*p = cpu_to_be32(NFS4_OPEN_DELEGATE_WRITE);
+		break;
+	default:
+		BUG();
+	}
+}
+
+static inline void encode_claim_null(struct xdr_stream *xdr, const struct qstr *name)
+{
+	__be32 *p;
+
+	p = reserve_space(xdr, 4);
+	*p = cpu_to_be32(NFS4_OPEN_CLAIM_NULL);
+	encode_string(xdr, name->len, name->name);
+}
+
+static inline void encode_claim_previous(struct xdr_stream *xdr, fmode_t type)
+{
+	__be32 *p;
+
+	p = reserve_space(xdr, 4);
+	*p = cpu_to_be32(NFS4_OPEN_CLAIM_PREVIOUS);
+	encode_delegation_type(xdr, type);
+}
+
+static inline void encode_claim_delegate_cur(struct xdr_stream *xdr, const struct qstr *name, const nfs4_stateid *stateid)
+{
+	__be32 *p;
+
+	p = reserve_space(xdr, 4);
+	*p = cpu_to_be32(NFS4_OPEN_CLAIM_DELEGATE_CUR);
+	encode_nfs4_stateid(xdr, stateid);
+	encode_string(xdr, name->len, name->name);
+}
+
+static inline void encode_claim_fh(struct xdr_stream *xdr)
+{
+	__be32 *p;
+
+	p = reserve_space(xdr, 4);
+	*p = cpu_to_be32(NFS4_OPEN_CLAIM_FH);
+}
+
+static inline void encode_claim_delegate_cur_fh(struct xdr_stream *xdr, const nfs4_stateid *stateid)
+{
+	__be32 *p;
+
+	p = reserve_space(xdr, 4);
+	*p = cpu_to_be32(NFS4_OPEN_CLAIM_DELEG_CUR_FH);
+	encode_nfs4_stateid(xdr, stateid);
+}
+
+static void encode_open(struct xdr_stream *xdr, const struct nfs_openargs *arg, struct compound_hdr *hdr)
+{
+	encode_op_hdr(xdr, OP_OPEN, decode_open_maxsz, hdr);
+	encode_openhdr(xdr, arg);
+	encode_opentype(xdr, arg);
+	switch (arg->claim) {
+	case NFS4_OPEN_CLAIM_NULL:
+		encode_claim_null(xdr, arg->name);
+		break;
+	case NFS4_OPEN_CLAIM_PREVIOUS:
+		encode_claim_previous(xdr, arg->u.delegation_type);
+		break;
+	case NFS4_OPEN_CLAIM_DELEGATE_CUR:
+		encode_claim_delegate_cur(xdr, arg->name, &arg->u.delegation);
+		break;
+	case NFS4_OPEN_CLAIM_FH:
+		encode_claim_fh(xdr);
+		break;
+	case NFS4_OPEN_CLAIM_DELEG_CUR_FH:
+		encode_claim_delegate_cur_fh(xdr, &arg->u.delegation);
+		break;
+	default:
+		BUG();
+	}
+}
+
+static void encode_open_confirm(struct xdr_stream *xdr, const struct nfs_open_confirmargs *arg, struct compound_hdr *hdr)
+{
+	encode_op_hdr(xdr, OP_OPEN_CONFIRM, decode_open_confirm_maxsz, hdr);
+	encode_nfs4_stateid(xdr, arg->stateid);
+	encode_nfs4_seqid(xdr, arg->seqid);
+}
+
+static void encode_open_downgrade(struct xdr_stream *xdr, const struct nfs_closeargs *arg, struct compound_hdr *hdr)
+{
+	encode_op_hdr(xdr, OP_OPEN_DOWNGRADE, decode_open_downgrade_maxsz, hdr);
+	encode_nfs4_stateid(xdr, &arg->stateid);
+	encode_nfs4_seqid(xdr, arg->seqid);
+	encode_share_access(xdr, arg->share_access);
+}
+
+static void
+encode_putfh(struct xdr_stream *xdr, const struct nfs_fh *fh, struct compound_hdr *hdr)
+{
+	encode_op_hdr(xdr, OP_PUTFH, decode_putfh_maxsz, hdr);
+	encode_string(xdr, fh->size, fh->data);
+}
+
+static void encode_putrootfh(struct xdr_stream *xdr, struct compound_hdr *hdr)
+{
+	encode_op_hdr(xdr, OP_PUTROOTFH, decode_putrootfh_maxsz, hdr);
+}
+
+static void encode_read(struct xdr_stream *xdr, const struct nfs_pgio_args *args,
+			struct compound_hdr *hdr)
+{
+	__be32 *p;
+
+	encode_op_hdr(xdr, OP_READ, decode_read_maxsz, hdr);
+	encode_nfs4_stateid(xdr, &args->stateid);
+
+	p = reserve_space(xdr, 12);
+	p = xdr_encode_hyper(p, args->offset);
+	*p = cpu_to_be32(args->count);
+}
+
+static void encode_readdir(struct xdr_stream *xdr, const struct nfs4_readdir_arg *readdir, struct rpc_rqst *req, struct compound_hdr *hdr)
+{
+	uint32_t attrs[3] = {
+		FATTR4_WORD0_RDATTR_ERROR,
+		FATTR4_WORD1_MOUNTED_ON_FILEID,
+	};
+	uint32_t dircount = readdir->count >> 1;
+	__be32 *p, verf[2];
+	uint32_t attrlen = 0;
+	unsigned int i;
+
+	if (readdir->plus) {
+		attrs[0] |= FATTR4_WORD0_TYPE|FATTR4_WORD0_CHANGE|FATTR4_WORD0_SIZE|
+			FATTR4_WORD0_FSID|FATTR4_WORD0_FILEHANDLE|FATTR4_WORD0_FILEID;
+		attrs[1] |= FATTR4_WORD1_MODE|FATTR4_WORD1_NUMLINKS|FATTR4_WORD1_OWNER|
+			FATTR4_WORD1_OWNER_GROUP|FATTR4_WORD1_RAWDEV|
+			FATTR4_WORD1_SPACE_USED|FATTR4_WORD1_TIME_ACCESS|
+			FATTR4_WORD1_TIME_METADATA|FATTR4_WORD1_TIME_MODIFY;
+		attrs[2] |= FATTR4_WORD2_SECURITY_LABEL;
+		dircount >>= 1;
+	}
+	/* Use mounted_on_fileid only if the server supports it */
+	if (!(readdir->bitmask[1] & FATTR4_WORD1_MOUNTED_ON_FILEID))
+		attrs[0] |= FATTR4_WORD0_FILEID;
+	for (i = 0; i < ARRAY_SIZE(attrs); i++) {
+		attrs[i] &= readdir->bitmask[i];
+		if (attrs[i] != 0)
+			attrlen = i+1;
+	}
+
+	encode_op_hdr(xdr, OP_READDIR, decode_readdir_maxsz, hdr);
+	encode_uint64(xdr, readdir->cookie);
+	encode_nfs4_verifier(xdr, &readdir->verifier);
+	p = reserve_space(xdr, 12 + (attrlen << 2));
+	*p++ = cpu_to_be32(dircount);
+	*p++ = cpu_to_be32(readdir->count);
+	*p++ = cpu_to_be32(attrlen);
+	for (i = 0; i < attrlen; i++)
+		*p++ = cpu_to_be32(attrs[i]);
+	memcpy(verf, readdir->verifier.data, sizeof(verf));
+
+	dprintk("%s: cookie = %llu, verifier = %08x:%08x, bitmap = %08x:%08x:%08x\n",
+			__func__,
+			(unsigned long long)readdir->cookie,
+			verf[0], verf[1],
+			attrs[0] & readdir->bitmask[0],
+			attrs[1] & readdir->bitmask[1],
+			attrs[2] & readdir->bitmask[2]);
+}
+
+static void encode_readlink(struct xdr_stream *xdr, const struct nfs4_readlink *readlink, struct rpc_rqst *req, struct compound_hdr *hdr)
+{
+	encode_op_hdr(xdr, OP_READLINK, decode_readlink_maxsz, hdr);
+}
+
+static void encode_remove(struct xdr_stream *xdr, const struct qstr *name, struct compound_hdr *hdr)
+{
+	encode_op_hdr(xdr, OP_REMOVE, decode_remove_maxsz, hdr);
+	encode_string(xdr, name->len, name->name);
+}
+
+static void encode_rename(struct xdr_stream *xdr, const struct qstr *oldname, const struct qstr *newname, struct compound_hdr *hdr)
+{
+	encode_op_hdr(xdr, OP_RENAME, decode_rename_maxsz, hdr);
+	encode_string(xdr, oldname->len, oldname->name);
+	encode_string(xdr, newname->len, newname->name);
+}
+
+static void encode_renew(struct xdr_stream *xdr, clientid4 clid,
+			 struct compound_hdr *hdr)
+{
+	encode_op_hdr(xdr, OP_RENEW, decode_renew_maxsz, hdr);
+	encode_uint64(xdr, clid);
+}
+
+static void
+encode_restorefh(struct xdr_stream *xdr, struct compound_hdr *hdr)
+{
+	encode_op_hdr(xdr, OP_RESTOREFH, decode_restorefh_maxsz, hdr);
+}
+
+static void
+encode_setacl(struct xdr_stream *xdr, const struct nfs_setaclargs *arg,
+		struct compound_hdr *hdr)
+{
+	__be32 *p;
+
+	encode_op_hdr(xdr, OP_SETATTR, decode_setacl_maxsz, hdr);
+	encode_nfs4_stateid(xdr, &zero_stateid);
+	p = reserve_space(xdr, 2*4);
+	*p++ = cpu_to_be32(1);
+	*p = cpu_to_be32(FATTR4_WORD0_ACL);
+	p = reserve_space(xdr, 4);
+	*p = cpu_to_be32(arg->acl_len);
+	xdr_write_pages(xdr, arg->acl_pages, 0, arg->acl_len);
+}
+
+static void
+encode_savefh(struct xdr_stream *xdr, struct compound_hdr *hdr)
+{
+	encode_op_hdr(xdr, OP_SAVEFH, decode_savefh_maxsz, hdr);
+}
+
+static void encode_setattr(struct xdr_stream *xdr, const struct nfs_setattrargs *arg, const struct nfs_server *server, struct compound_hdr *hdr)
+{
+	encode_op_hdr(xdr, OP_SETATTR, decode_setattr_maxsz, hdr);
+	encode_nfs4_stateid(xdr, &arg->stateid);
+	encode_attrs(xdr, arg->iap, arg->label, NULL, server,
+			server->attr_bitmask);
+}
+
+static void encode_setclientid(struct xdr_stream *xdr, const struct nfs4_setclientid *setclientid, struct compound_hdr *hdr)
+{
+	__be32 *p;
+
+	encode_op_hdr(xdr, OP_SETCLIENTID, decode_setclientid_maxsz, hdr);
+	encode_nfs4_verifier(xdr, setclientid->sc_verifier);
+
+	encode_string(xdr, strlen(setclientid->sc_clnt->cl_owner_id),
+			setclientid->sc_clnt->cl_owner_id);
+	p = reserve_space(xdr, 4);
+	*p = cpu_to_be32(setclientid->sc_prog);
+	encode_string(xdr, setclientid->sc_netid_len, setclientid->sc_netid);
+	encode_string(xdr, setclientid->sc_uaddr_len, setclientid->sc_uaddr);
+	p = reserve_space(xdr, 4);
+	*p = cpu_to_be32(setclientid->sc_clnt->cl_cb_ident);
+}
+
+static void encode_setclientid_confirm(struct xdr_stream *xdr, const struct nfs4_setclientid_res *arg, struct compound_hdr *hdr)
+{
+	encode_op_hdr(xdr, OP_SETCLIENTID_CONFIRM,
+			decode_setclientid_confirm_maxsz, hdr);
+	encode_uint64(xdr, arg->clientid);
+	encode_nfs4_verifier(xdr, &arg->confirm);
+}
+
+static void encode_write(struct xdr_stream *xdr, const struct nfs_pgio_args *args,
+			 struct compound_hdr *hdr)
+{
+	__be32 *p;
+
+	encode_op_hdr(xdr, OP_WRITE, decode_write_maxsz, hdr);
+	encode_nfs4_stateid(xdr, &args->stateid);
+
+	p = reserve_space(xdr, 16);
+	p = xdr_encode_hyper(p, args->offset);
+	*p++ = cpu_to_be32(args->stable);
+	*p = cpu_to_be32(args->count);
+
+	xdr_write_pages(xdr, args->pages, args->pgbase, args->count);
+}
+
+static void encode_delegreturn(struct xdr_stream *xdr, const nfs4_stateid *stateid, struct compound_hdr *hdr)
+{
+	encode_op_hdr(xdr, OP_DELEGRETURN, decode_delegreturn_maxsz, hdr);
+	encode_nfs4_stateid(xdr, stateid);
+}
+
+static void encode_secinfo(struct xdr_stream *xdr, const struct qstr *name, struct compound_hdr *hdr)
+{
+	encode_op_hdr(xdr, OP_SECINFO, decode_secinfo_maxsz, hdr);
+	encode_string(xdr, name->len, name->name);
+}
+
+#if defined(CONFIG_NFS_V4_1)
+/* NFSv4.1 operations */
+static void encode_bind_conn_to_session(struct xdr_stream *xdr,
+				   const struct nfs41_bind_conn_to_session_args *args,
+				   struct compound_hdr *hdr)
+{
+	__be32 *p;
+
+	encode_op_hdr(xdr, OP_BIND_CONN_TO_SESSION,
+		decode_bind_conn_to_session_maxsz, hdr);
+	encode_opaque_fixed(xdr, args->sessionid.data, NFS4_MAX_SESSIONID_LEN);
+	p = xdr_reserve_space(xdr, 8);
+	*p++ = cpu_to_be32(args->dir);
+	*p = (args->use_conn_in_rdma_mode) ? cpu_to_be32(1) : cpu_to_be32(0);
+}
+
+static void encode_op_map(struct xdr_stream *xdr, const struct nfs4_op_map *op_map)
+{
+	unsigned int i;
+	encode_uint32(xdr, NFS4_OP_MAP_NUM_WORDS);
+	for (i = 0; i < NFS4_OP_MAP_NUM_WORDS; i++)
+		encode_uint32(xdr, op_map->u.words[i]);
+}
+
+static void encode_exchange_id(struct xdr_stream *xdr,
+			       const struct nfs41_exchange_id_args *args,
+			       struct compound_hdr *hdr)
+{
+	__be32 *p;
+	char impl_name[IMPL_NAME_LIMIT];
+	int len = 0;
+
+	encode_op_hdr(xdr, OP_EXCHANGE_ID, decode_exchange_id_maxsz, hdr);
+	encode_nfs4_verifier(xdr, &args->verifier);
+
+	encode_string(xdr, strlen(args->client->cl_owner_id),
+			args->client->cl_owner_id);
+
+	encode_uint32(xdr, args->flags);
+	encode_uint32(xdr, args->state_protect.how);
+
+	switch (args->state_protect.how) {
+	case SP4_NONE:
+		break;
+	case SP4_MACH_CRED:
+		encode_op_map(xdr, &args->state_protect.enforce);
+		encode_op_map(xdr, &args->state_protect.allow);
+		break;
+	default:
+		WARN_ON_ONCE(1);
+		break;
+	}
+
+	if (send_implementation_id &&
+	    sizeof(CONFIG_NFS_V4_1_IMPLEMENTATION_ID_DOMAIN) > 1 &&
+	    sizeof(CONFIG_NFS_V4_1_IMPLEMENTATION_ID_DOMAIN)
+		<= sizeof(impl_name) + 1)
+		len = snprintf(impl_name, sizeof(impl_name), "%s %s %s %s",
+			       utsname()->sysname, utsname()->release,
+			       utsname()->version, utsname()->machine);
+
+	if (len > 0) {
+		encode_uint32(xdr, 1);	/* implementation id array length=1 */
+
+		encode_string(xdr,
+			sizeof(CONFIG_NFS_V4_1_IMPLEMENTATION_ID_DOMAIN) - 1,
+			CONFIG_NFS_V4_1_IMPLEMENTATION_ID_DOMAIN);
+		encode_string(xdr, len, impl_name);
+		/* just send zeros for nii_date - the date is in nii_name */
+		p = reserve_space(xdr, 12);
+		p = xdr_encode_hyper(p, 0);
+		*p = cpu_to_be32(0);
+	} else
+		encode_uint32(xdr, 0);	/* implementation id array length=0 */
+}
+
+static void encode_create_session(struct xdr_stream *xdr,
+				  const struct nfs41_create_session_args *args,
+				  struct compound_hdr *hdr)
+{
+	__be32 *p;
+	struct nfs_client *clp = args->client;
+	struct rpc_clnt *clnt = clp->cl_rpcclient;
+	struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
+	u32 max_resp_sz_cached;
+
+	/*
+	 * Assumes OPEN is the biggest non-idempotent compound.
+	 * 2 is the verifier.
+	 */
+	max_resp_sz_cached = (NFS4_dec_open_sz + RPC_REPHDRSIZE + 2)
+				* XDR_UNIT + RPC_MAX_AUTH_SIZE;
+
+	encode_op_hdr(xdr, OP_CREATE_SESSION, decode_create_session_maxsz, hdr);
+	p = reserve_space(xdr, 16 + 2*28 + 20 + clnt->cl_nodelen + 12);
+	p = xdr_encode_hyper(p, args->clientid);
+	*p++ = cpu_to_be32(args->seqid);			/*Sequence id */
+	*p++ = cpu_to_be32(args->flags);			/*flags */
+
+	/* Fore Channel */
+	*p++ = cpu_to_be32(0);				/* header padding size */
+	*p++ = cpu_to_be32(args->fc_attrs.max_rqst_sz);	/* max req size */
+	*p++ = cpu_to_be32(args->fc_attrs.max_resp_sz);	/* max resp size */
+	*p++ = cpu_to_be32(max_resp_sz_cached);		/* Max resp sz cached */
+	*p++ = cpu_to_be32(args->fc_attrs.max_ops);	/* max operations */
+	*p++ = cpu_to_be32(args->fc_attrs.max_reqs);	/* max requests */
+	*p++ = cpu_to_be32(0);				/* rdmachannel_attrs */
+
+	/* Back Channel */
+	*p++ = cpu_to_be32(0);				/* header padding size */
+	*p++ = cpu_to_be32(args->bc_attrs.max_rqst_sz);	/* max req size */
+	*p++ = cpu_to_be32(args->bc_attrs.max_resp_sz);	/* max resp size */
+	*p++ = cpu_to_be32(args->bc_attrs.max_resp_sz_cached);	/* Max resp sz cached */
+	*p++ = cpu_to_be32(args->bc_attrs.max_ops);	/* max operations */
+	*p++ = cpu_to_be32(args->bc_attrs.max_reqs);	/* max requests */
+	*p++ = cpu_to_be32(0);				/* rdmachannel_attrs */
+
+	*p++ = cpu_to_be32(args->cb_program);		/* cb_program */
+	*p++ = cpu_to_be32(1);
+	*p++ = cpu_to_be32(RPC_AUTH_UNIX);			/* auth_sys */
+
+	/* authsys_parms rfc1831 */
+	*p++ = cpu_to_be32(ktime_to_ns(nn->boot_time));	/* stamp */
+	p = xdr_encode_array(p, clnt->cl_nodename, clnt->cl_nodelen);
+	*p++ = cpu_to_be32(0);				/* UID */
+	*p++ = cpu_to_be32(0);				/* GID */
+	*p = cpu_to_be32(0);				/* No more gids */
+}
+
+static void encode_destroy_session(struct xdr_stream *xdr,
+				   const struct nfs4_session *session,
+				   struct compound_hdr *hdr)
+{
+	encode_op_hdr(xdr, OP_DESTROY_SESSION, decode_destroy_session_maxsz, hdr);
+	encode_opaque_fixed(xdr, session->sess_id.data, NFS4_MAX_SESSIONID_LEN);
+}
+
+static void encode_destroy_clientid(struct xdr_stream *xdr,
+				   uint64_t clientid,
+				   struct compound_hdr *hdr)
+{
+	encode_op_hdr(xdr, OP_DESTROY_CLIENTID, decode_destroy_clientid_maxsz, hdr);
+	encode_uint64(xdr, clientid);
+}
+
+static void encode_reclaim_complete(struct xdr_stream *xdr,
+				    const struct nfs41_reclaim_complete_args *args,
+				    struct compound_hdr *hdr)
+{
+	encode_op_hdr(xdr, OP_RECLAIM_COMPLETE, decode_reclaim_complete_maxsz, hdr);
+	encode_uint32(xdr, args->one_fs);
+}
+#endif /* CONFIG_NFS_V4_1 */
+
+static void encode_sequence(struct xdr_stream *xdr,
+			    const struct nfs4_sequence_args *args,
+			    struct compound_hdr *hdr)
+{
+#if defined(CONFIG_NFS_V4_1)
+	struct nfs4_session *session;
+	struct nfs4_slot_table *tp;
+	struct nfs4_slot *slot = args->sa_slot;
+	__be32 *p;
+
+	tp = slot->table;
+	session = tp->session;
+	if (!session)
+		return;
+
+	encode_op_hdr(xdr, OP_SEQUENCE, decode_sequence_maxsz, hdr);
+
+	/*
+	 * Sessionid + seqid + slotid + max slotid + cache_this
+	 */
+	dprintk("%s: sessionid=%u:%u:%u:%u seqid=%d slotid=%d "
+		"max_slotid=%d cache_this=%d\n",
+		__func__,
+		((u32 *)session->sess_id.data)[0],
+		((u32 *)session->sess_id.data)[1],
+		((u32 *)session->sess_id.data)[2],
+		((u32 *)session->sess_id.data)[3],
+		slot->seq_nr, slot->slot_nr,
+		tp->highest_used_slotid, args->sa_cache_this);
+	p = reserve_space(xdr, NFS4_MAX_SESSIONID_LEN + 16);
+	p = xdr_encode_opaque_fixed(p, session->sess_id.data, NFS4_MAX_SESSIONID_LEN);
+	*p++ = cpu_to_be32(slot->seq_nr);
+	*p++ = cpu_to_be32(slot->slot_nr);
+	*p++ = cpu_to_be32(tp->highest_used_slotid);
+	*p = cpu_to_be32(args->sa_cache_this);
+#endif /* CONFIG_NFS_V4_1 */
+}
+
+#ifdef CONFIG_NFS_V4_1
+static void
+encode_getdeviceinfo(struct xdr_stream *xdr,
+		     const struct nfs4_getdeviceinfo_args *args,
+		     struct compound_hdr *hdr)
+{
+	__be32 *p;
+
+	encode_op_hdr(xdr, OP_GETDEVICEINFO, decode_getdeviceinfo_maxsz, hdr);
+	p = reserve_space(xdr, NFS4_DEVICEID4_SIZE + 4 + 4);
+	p = xdr_encode_opaque_fixed(p, args->pdev->dev_id.data,
+				    NFS4_DEVICEID4_SIZE);
+	*p++ = cpu_to_be32(args->pdev->layout_type);
+	*p++ = cpu_to_be32(args->pdev->maxcount);	/* gdia_maxcount */
+
+	p = reserve_space(xdr, 4 + 4);
+	*p++ = cpu_to_be32(1);			/* bitmap length */
+	*p++ = cpu_to_be32(args->notify_types);
+}
+
+static void
+encode_layoutget(struct xdr_stream *xdr,
+		      const struct nfs4_layoutget_args *args,
+		      struct compound_hdr *hdr)
+{
+	__be32 *p;
+
+	encode_op_hdr(xdr, OP_LAYOUTGET, decode_layoutget_maxsz, hdr);
+	p = reserve_space(xdr, 36);
+	*p++ = cpu_to_be32(0);     /* Signal layout available */
+	*p++ = cpu_to_be32(args->type);
+	*p++ = cpu_to_be32(args->range.iomode);
+	p = xdr_encode_hyper(p, args->range.offset);
+	p = xdr_encode_hyper(p, args->range.length);
+	p = xdr_encode_hyper(p, args->minlength);
+	encode_nfs4_stateid(xdr, &args->stateid);
+	encode_uint32(xdr, args->maxcount);
+
+	dprintk("%s: 1st type:0x%x iomode:%d off:%lu len:%lu mc:%d\n",
+		__func__,
+		args->type,
+		args->range.iomode,
+		(unsigned long)args->range.offset,
+		(unsigned long)args->range.length,
+		args->maxcount);
+}
+
+static int
+encode_layoutcommit(struct xdr_stream *xdr,
+		    struct inode *inode,
+		    const struct nfs4_layoutcommit_args *args,
+		    struct compound_hdr *hdr)
+{
+	__be32 *p;
+
+	dprintk("%s: lbw: %llu type: %d\n", __func__, args->lastbytewritten,
+		NFS_SERVER(args->inode)->pnfs_curr_ld->id);
+
+	encode_op_hdr(xdr, OP_LAYOUTCOMMIT, decode_layoutcommit_maxsz, hdr);
+	p = reserve_space(xdr, 20);
+	/* Only whole file layouts */
+	p = xdr_encode_hyper(p, 0); /* offset */
+	p = xdr_encode_hyper(p, args->lastbytewritten + 1);	/* length */
+	*p = cpu_to_be32(0); /* reclaim */
+	encode_nfs4_stateid(xdr, &args->stateid);
+	if (args->lastbytewritten != U64_MAX) {
+		p = reserve_space(xdr, 20);
+		*p++ = cpu_to_be32(1); /* newoffset = TRUE */
+		p = xdr_encode_hyper(p, args->lastbytewritten);
+	} else {
+		p = reserve_space(xdr, 12);
+		*p++ = cpu_to_be32(0); /* newoffset = FALSE */
+	}
+	*p++ = cpu_to_be32(0); /* Never send time_modify_changed */
+	*p++ = cpu_to_be32(NFS_SERVER(args->inode)->pnfs_curr_ld->id);/* type */
+
+	encode_uint32(xdr, args->layoutupdate_len);
+	if (args->layoutupdate_pages)
+		xdr_write_pages(xdr, args->layoutupdate_pages, 0,
+				args->layoutupdate_len);
+
+	return 0;
+}
+
+static void
+encode_layoutreturn(struct xdr_stream *xdr,
+		    const struct nfs4_layoutreturn_args *args,
+		    struct compound_hdr *hdr)
+{
+	__be32 *p;
+
+	encode_op_hdr(xdr, OP_LAYOUTRETURN, decode_layoutreturn_maxsz, hdr);
+	p = reserve_space(xdr, 16);
+	*p++ = cpu_to_be32(0);		/* reclaim. always 0 for now */
+	*p++ = cpu_to_be32(args->layout_type);
+	*p++ = cpu_to_be32(args->range.iomode);
+	*p = cpu_to_be32(RETURN_FILE);
+	p = reserve_space(xdr, 16);
+	p = xdr_encode_hyper(p, args->range.offset);
+	p = xdr_encode_hyper(p, args->range.length);
+	spin_lock(&args->inode->i_lock);
+	encode_nfs4_stateid(xdr, &args->stateid);
+	spin_unlock(&args->inode->i_lock);
+	if (args->ld_private->ops && args->ld_private->ops->encode)
+		args->ld_private->ops->encode(xdr, args, args->ld_private);
+	else
+		encode_uint32(xdr, 0);
+}
+
+static int
+encode_secinfo_no_name(struct xdr_stream *xdr,
+		       const struct nfs41_secinfo_no_name_args *args,
+		       struct compound_hdr *hdr)
+{
+	encode_op_hdr(xdr, OP_SECINFO_NO_NAME, decode_secinfo_no_name_maxsz, hdr);
+	encode_uint32(xdr, args->style);
+	return 0;
+}
+
+static void encode_test_stateid(struct xdr_stream *xdr,
+				const struct nfs41_test_stateid_args *args,
+				struct compound_hdr *hdr)
+{
+	encode_op_hdr(xdr, OP_TEST_STATEID, decode_test_stateid_maxsz, hdr);
+	encode_uint32(xdr, 1);
+	encode_nfs4_stateid(xdr, args->stateid);
+}
+
+static void encode_free_stateid(struct xdr_stream *xdr,
+				const struct nfs41_free_stateid_args *args,
+				struct compound_hdr *hdr)
+{
+	encode_op_hdr(xdr, OP_FREE_STATEID, decode_free_stateid_maxsz, hdr);
+	encode_nfs4_stateid(xdr, &args->stateid);
+}
+#else
+static inline void
+encode_layoutreturn(struct xdr_stream *xdr,
+		    const struct nfs4_layoutreturn_args *args,
+		    struct compound_hdr *hdr)
+{
+}
+
+static void
+encode_layoutget(struct xdr_stream *xdr,
+		      const struct nfs4_layoutget_args *args,
+		      struct compound_hdr *hdr)
+{
+}
+#endif /* CONFIG_NFS_V4_1 */
+
+/*
+ * END OF "GENERIC" ENCODE ROUTINES.
+ */
+
+static u32 nfs4_xdr_minorversion(const struct nfs4_sequence_args *args)
+{
+#if defined(CONFIG_NFS_V4_1)
+	struct nfs4_session *session = args->sa_slot->table->session;
+	if (session)
+		return session->clp->cl_mvops->minor_version;
+#endif /* CONFIG_NFS_V4_1 */
+	return 0;
+}
+
+/*
+ * Encode an ACCESS request
+ */
+static void nfs4_xdr_enc_access(struct rpc_rqst *req, struct xdr_stream *xdr,
+				const void *data)
+{
+	const struct nfs4_accessargs *args = data;
+	struct compound_hdr hdr = {
+		.minorversion = nfs4_xdr_minorversion(&args->seq_args),
+	};
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_sequence(xdr, &args->seq_args, &hdr);
+	encode_putfh(xdr, args->fh, &hdr);
+	encode_access(xdr, args->access, &hdr);
+	if (args->bitmask)
+		encode_getfattr(xdr, args->bitmask, &hdr);
+	encode_nops(&hdr);
+}
+
+/*
+ * Encode LOOKUP request
+ */
+static void nfs4_xdr_enc_lookup(struct rpc_rqst *req, struct xdr_stream *xdr,
+				const void *data)
+{
+	const struct nfs4_lookup_arg *args = data;
+	struct compound_hdr hdr = {
+		.minorversion = nfs4_xdr_minorversion(&args->seq_args),
+	};
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_sequence(xdr, &args->seq_args, &hdr);
+	encode_putfh(xdr, args->dir_fh, &hdr);
+	encode_lookup(xdr, args->name, &hdr);
+	encode_getfh(xdr, &hdr);
+	encode_getfattr(xdr, args->bitmask, &hdr);
+	encode_nops(&hdr);
+}
+
+/*
+ * Encode LOOKUPP request
+ */
+static void nfs4_xdr_enc_lookupp(struct rpc_rqst *req, struct xdr_stream *xdr,
+		const void *data)
+{
+	const struct nfs4_lookupp_arg *args = data;
+	struct compound_hdr hdr = {
+		.minorversion = nfs4_xdr_minorversion(&args->seq_args),
+	};
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_sequence(xdr, &args->seq_args, &hdr);
+	encode_putfh(xdr, args->fh, &hdr);
+	encode_lookupp(xdr, &hdr);
+	encode_getfh(xdr, &hdr);
+	encode_getfattr(xdr, args->bitmask, &hdr);
+	encode_nops(&hdr);
+}
+
+/*
+ * Encode LOOKUP_ROOT request
+ */
+static void nfs4_xdr_enc_lookup_root(struct rpc_rqst *req,
+				     struct xdr_stream *xdr,
+				     const void *data)
+{
+	const struct nfs4_lookup_root_arg *args = data;
+	struct compound_hdr hdr = {
+		.minorversion = nfs4_xdr_minorversion(&args->seq_args),
+	};
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_sequence(xdr, &args->seq_args, &hdr);
+	encode_putrootfh(xdr, &hdr);
+	encode_getfh(xdr, &hdr);
+	encode_getfattr(xdr, args->bitmask, &hdr);
+	encode_nops(&hdr);
+}
+
+/*
+ * Encode REMOVE request
+ */
+static void nfs4_xdr_enc_remove(struct rpc_rqst *req, struct xdr_stream *xdr,
+				const void *data)
+{
+	const struct nfs_removeargs *args = data;
+	struct compound_hdr hdr = {
+		.minorversion = nfs4_xdr_minorversion(&args->seq_args),
+	};
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_sequence(xdr, &args->seq_args, &hdr);
+	encode_putfh(xdr, args->fh, &hdr);
+	encode_remove(xdr, &args->name, &hdr);
+	encode_nops(&hdr);
+}
+
+/*
+ * Encode RENAME request
+ */
+static void nfs4_xdr_enc_rename(struct rpc_rqst *req, struct xdr_stream *xdr,
+				const void *data)
+{
+	const struct nfs_renameargs *args = data;
+	struct compound_hdr hdr = {
+		.minorversion = nfs4_xdr_minorversion(&args->seq_args),
+	};
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_sequence(xdr, &args->seq_args, &hdr);
+	encode_putfh(xdr, args->old_dir, &hdr);
+	encode_savefh(xdr, &hdr);
+	encode_putfh(xdr, args->new_dir, &hdr);
+	encode_rename(xdr, args->old_name, args->new_name, &hdr);
+	encode_nops(&hdr);
+}
+
+/*
+ * Encode LINK request
+ */
+static void nfs4_xdr_enc_link(struct rpc_rqst *req, struct xdr_stream *xdr,
+			      const void *data)
+{
+	const struct nfs4_link_arg *args = data;
+	struct compound_hdr hdr = {
+		.minorversion = nfs4_xdr_minorversion(&args->seq_args),
+	};
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_sequence(xdr, &args->seq_args, &hdr);
+	encode_putfh(xdr, args->fh, &hdr);
+	encode_savefh(xdr, &hdr);
+	encode_putfh(xdr, args->dir_fh, &hdr);
+	encode_link(xdr, args->name, &hdr);
+	encode_restorefh(xdr, &hdr);
+	encode_getfattr(xdr, args->bitmask, &hdr);
+	encode_nops(&hdr);
+}
+
+/*
+ * Encode CREATE request
+ */
+static void nfs4_xdr_enc_create(struct rpc_rqst *req, struct xdr_stream *xdr,
+				const void *data)
+{
+	const struct nfs4_create_arg *args = data;
+	struct compound_hdr hdr = {
+		.minorversion = nfs4_xdr_minorversion(&args->seq_args),
+	};
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_sequence(xdr, &args->seq_args, &hdr);
+	encode_putfh(xdr, args->dir_fh, &hdr);
+	encode_create(xdr, args, &hdr);
+	encode_getfh(xdr, &hdr);
+	encode_getfattr(xdr, args->bitmask, &hdr);
+	encode_nops(&hdr);
+}
+
+/*
+ * Encode SYMLINK request
+ */
+static void nfs4_xdr_enc_symlink(struct rpc_rqst *req, struct xdr_stream *xdr,
+				 const void *data)
+{
+	const struct nfs4_create_arg *args = data;
+
+	nfs4_xdr_enc_create(req, xdr, args);
+}
+
+/*
+ * Encode GETATTR request
+ */
+static void nfs4_xdr_enc_getattr(struct rpc_rqst *req, struct xdr_stream *xdr,
+				 const void *data)
+{
+	const struct nfs4_getattr_arg *args = data;
+	struct compound_hdr hdr = {
+		.minorversion = nfs4_xdr_minorversion(&args->seq_args),
+	};
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_sequence(xdr, &args->seq_args, &hdr);
+	encode_putfh(xdr, args->fh, &hdr);
+	encode_getfattr(xdr, args->bitmask, &hdr);
+	encode_nops(&hdr);
+}
+
+/*
+ * Encode a CLOSE request
+ */
+static void nfs4_xdr_enc_close(struct rpc_rqst *req, struct xdr_stream *xdr,
+			       const void *data)
+{
+	const struct nfs_closeargs *args = data;
+	struct compound_hdr hdr = {
+		.minorversion = nfs4_xdr_minorversion(&args->seq_args),
+	};
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_sequence(xdr, &args->seq_args, &hdr);
+	encode_putfh(xdr, args->fh, &hdr);
+	if (args->lr_args)
+		encode_layoutreturn(xdr, args->lr_args, &hdr);
+	if (args->bitmask != NULL)
+		encode_getfattr(xdr, args->bitmask, &hdr);
+	encode_close(xdr, args, &hdr);
+	encode_nops(&hdr);
+}
+
+/*
+ * Encode an OPEN request
+ */
+static void nfs4_xdr_enc_open(struct rpc_rqst *req, struct xdr_stream *xdr,
+			      const void *data)
+{
+	const struct nfs_openargs *args = data;
+	struct compound_hdr hdr = {
+		.minorversion = nfs4_xdr_minorversion(&args->seq_args),
+	};
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_sequence(xdr, &args->seq_args, &hdr);
+	encode_putfh(xdr, args->fh, &hdr);
+	encode_open(xdr, args, &hdr);
+	encode_getfh(xdr, &hdr);
+	if (args->access)
+		encode_access(xdr, args->access, &hdr);
+	encode_getfattr_open(xdr, args->bitmask, args->open_bitmap, &hdr);
+	if (args->lg_args) {
+		encode_layoutget(xdr, args->lg_args, &hdr);
+		rpc_prepare_reply_pages(req, args->lg_args->layout.pages, 0,
+					args->lg_args->layout.pglen,
+					hdr.replen);
+	}
+	encode_nops(&hdr);
+}
+
+/*
+ * Encode an OPEN_CONFIRM request
+ */
+static void nfs4_xdr_enc_open_confirm(struct rpc_rqst *req,
+				      struct xdr_stream *xdr,
+				      const void *data)
+{
+	const struct nfs_open_confirmargs *args = data;
+	struct compound_hdr hdr = {
+		.nops   = 0,
+	};
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_putfh(xdr, args->fh, &hdr);
+	encode_open_confirm(xdr, args, &hdr);
+	encode_nops(&hdr);
+}
+
+/*
+ * Encode an OPEN request with no attributes.
+ */
+static void nfs4_xdr_enc_open_noattr(struct rpc_rqst *req,
+				     struct xdr_stream *xdr,
+				     const void *data)
+{
+	const struct nfs_openargs *args = data;
+	struct compound_hdr hdr = {
+		.minorversion = nfs4_xdr_minorversion(&args->seq_args),
+	};
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_sequence(xdr, &args->seq_args, &hdr);
+	encode_putfh(xdr, args->fh, &hdr);
+	encode_open(xdr, args, &hdr);
+	if (args->access)
+		encode_access(xdr, args->access, &hdr);
+	encode_getfattr_open(xdr, args->bitmask, args->open_bitmap, &hdr);
+	if (args->lg_args) {
+		encode_layoutget(xdr, args->lg_args, &hdr);
+		rpc_prepare_reply_pages(req, args->lg_args->layout.pages, 0,
+					args->lg_args->layout.pglen,
+					hdr.replen);
+	}
+	encode_nops(&hdr);
+}
+
+/*
+ * Encode an OPEN_DOWNGRADE request
+ */
+static void nfs4_xdr_enc_open_downgrade(struct rpc_rqst *req,
+					struct xdr_stream *xdr,
+					const void *data)
+{
+	const struct nfs_closeargs *args = data;
+	struct compound_hdr hdr = {
+		.minorversion = nfs4_xdr_minorversion(&args->seq_args),
+	};
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_sequence(xdr, &args->seq_args, &hdr);
+	encode_putfh(xdr, args->fh, &hdr);
+	if (args->lr_args)
+		encode_layoutreturn(xdr, args->lr_args, &hdr);
+	encode_open_downgrade(xdr, args, &hdr);
+	encode_nops(&hdr);
+}
+
+/*
+ * Encode a LOCK request
+ */
+static void nfs4_xdr_enc_lock(struct rpc_rqst *req, struct xdr_stream *xdr,
+			      const void *data)
+{
+	const struct nfs_lock_args *args = data;
+	struct compound_hdr hdr = {
+		.minorversion = nfs4_xdr_minorversion(&args->seq_args),
+	};
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_sequence(xdr, &args->seq_args, &hdr);
+	encode_putfh(xdr, args->fh, &hdr);
+	encode_lock(xdr, args, &hdr);
+	encode_nops(&hdr);
+}
+
+/*
+ * Encode a LOCKT request
+ */
+static void nfs4_xdr_enc_lockt(struct rpc_rqst *req, struct xdr_stream *xdr,
+			       const void *data)
+{
+	const struct nfs_lockt_args *args = data;
+	struct compound_hdr hdr = {
+		.minorversion = nfs4_xdr_minorversion(&args->seq_args),
+	};
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_sequence(xdr, &args->seq_args, &hdr);
+	encode_putfh(xdr, args->fh, &hdr);
+	encode_lockt(xdr, args, &hdr);
+	encode_nops(&hdr);
+}
+
+/*
+ * Encode a LOCKU request
+ */
+static void nfs4_xdr_enc_locku(struct rpc_rqst *req, struct xdr_stream *xdr,
+			       const void *data)
+{
+	const struct nfs_locku_args *args = data;
+	struct compound_hdr hdr = {
+		.minorversion = nfs4_xdr_minorversion(&args->seq_args),
+	};
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_sequence(xdr, &args->seq_args, &hdr);
+	encode_putfh(xdr, args->fh, &hdr);
+	encode_locku(xdr, args, &hdr);
+	encode_nops(&hdr);
+}
+
+static void nfs4_xdr_enc_release_lockowner(struct rpc_rqst *req,
+					   struct xdr_stream *xdr,
+					   const void *data)
+{
+	const struct nfs_release_lockowner_args *args = data;
+	struct compound_hdr hdr = {
+		.minorversion = 0,
+	};
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_release_lockowner(xdr, &args->lock_owner, &hdr);
+	encode_nops(&hdr);
+}
+
+/*
+ * Encode a READLINK request
+ */
+static void nfs4_xdr_enc_readlink(struct rpc_rqst *req, struct xdr_stream *xdr,
+				  const void *data)
+{
+	const struct nfs4_readlink *args = data;
+	struct compound_hdr hdr = {
+		.minorversion = nfs4_xdr_minorversion(&args->seq_args),
+	};
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_sequence(xdr, &args->seq_args, &hdr);
+	encode_putfh(xdr, args->fh, &hdr);
+	encode_readlink(xdr, args, req, &hdr);
+
+	rpc_prepare_reply_pages(req, args->pages, args->pgbase,
+				args->pglen, hdr.replen);
+	encode_nops(&hdr);
+}
+
+/*
+ * Encode a READDIR request
+ */
+static void nfs4_xdr_enc_readdir(struct rpc_rqst *req, struct xdr_stream *xdr,
+				 const void *data)
+{
+	const struct nfs4_readdir_arg *args = data;
+	struct compound_hdr hdr = {
+		.minorversion = nfs4_xdr_minorversion(&args->seq_args),
+	};
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_sequence(xdr, &args->seq_args, &hdr);
+	encode_putfh(xdr, args->fh, &hdr);
+	encode_readdir(xdr, args, req, &hdr);
+
+	rpc_prepare_reply_pages(req, args->pages, args->pgbase,
+				args->count, hdr.replen);
+	encode_nops(&hdr);
+}
+
+/*
+ * Encode a READ request
+ */
+static void nfs4_xdr_enc_read(struct rpc_rqst *req, struct xdr_stream *xdr,
+			      const void *data)
+{
+	const struct nfs_pgio_args *args = data;
+	struct compound_hdr hdr = {
+		.minorversion = nfs4_xdr_minorversion(&args->seq_args),
+	};
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_sequence(xdr, &args->seq_args, &hdr);
+	encode_putfh(xdr, args->fh, &hdr);
+	encode_read(xdr, args, &hdr);
+
+	rpc_prepare_reply_pages(req, args->pages, args->pgbase,
+				args->count, hdr.replen);
+	req->rq_rcv_buf.flags |= XDRBUF_READ;
+	encode_nops(&hdr);
+}
+
+/*
+ * Encode an SETATTR request
+ */
+static void nfs4_xdr_enc_setattr(struct rpc_rqst *req, struct xdr_stream *xdr,
+				 const void *data)
+{
+	const struct nfs_setattrargs *args = data;
+	struct compound_hdr hdr = {
+		.minorversion = nfs4_xdr_minorversion(&args->seq_args),
+	};
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_sequence(xdr, &args->seq_args, &hdr);
+	encode_putfh(xdr, args->fh, &hdr);
+	encode_setattr(xdr, args, args->server, &hdr);
+	encode_getfattr(xdr, args->bitmask, &hdr);
+	encode_nops(&hdr);
+}
+
+/*
+ * Encode a GETACL request
+ */
+static void nfs4_xdr_enc_getacl(struct rpc_rqst *req, struct xdr_stream *xdr,
+				const void *data)
+{
+	const struct nfs_getaclargs *args = data;
+	struct compound_hdr hdr = {
+		.minorversion = nfs4_xdr_minorversion(&args->seq_args),
+	};
+	const __u32 nfs4_acl_bitmap[1] = {
+		[0] = FATTR4_WORD0_ACL,
+	};
+	uint32_t replen;
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_sequence(xdr, &args->seq_args, &hdr);
+	encode_putfh(xdr, args->fh, &hdr);
+	replen = hdr.replen + op_decode_hdr_maxsz;
+	encode_getattr(xdr, nfs4_acl_bitmap, NULL,
+			ARRAY_SIZE(nfs4_acl_bitmap), &hdr);
+
+	rpc_prepare_reply_pages(req, args->acl_pages, 0,
+				args->acl_len, replen + 1);
+	encode_nops(&hdr);
+}
+
+/*
+ * Encode a WRITE request
+ */
+static void nfs4_xdr_enc_write(struct rpc_rqst *req, struct xdr_stream *xdr,
+			       const void *data)
+{
+	const struct nfs_pgio_args *args = data;
+	struct compound_hdr hdr = {
+		.minorversion = nfs4_xdr_minorversion(&args->seq_args),
+	};
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_sequence(xdr, &args->seq_args, &hdr);
+	encode_putfh(xdr, args->fh, &hdr);
+	encode_write(xdr, args, &hdr);
+	req->rq_snd_buf.flags |= XDRBUF_WRITE;
+	if (args->bitmask)
+		encode_getfattr(xdr, args->bitmask, &hdr);
+	encode_nops(&hdr);
+}
+
+/*
+ *  a COMMIT request
+ */
+static void nfs4_xdr_enc_commit(struct rpc_rqst *req, struct xdr_stream *xdr,
+				const void *data)
+{
+	const struct nfs_commitargs *args = data;
+	struct compound_hdr hdr = {
+		.minorversion = nfs4_xdr_minorversion(&args->seq_args),
+	};
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_sequence(xdr, &args->seq_args, &hdr);
+	encode_putfh(xdr, args->fh, &hdr);
+	encode_commit(xdr, args, &hdr);
+	encode_nops(&hdr);
+}
+
+/*
+ * FSINFO request
+ */
+static void nfs4_xdr_enc_fsinfo(struct rpc_rqst *req, struct xdr_stream *xdr,
+				const void *data)
+{
+	const struct nfs4_fsinfo_arg *args = data;
+	struct compound_hdr hdr = {
+		.minorversion = nfs4_xdr_minorversion(&args->seq_args),
+	};
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_sequence(xdr, &args->seq_args, &hdr);
+	encode_putfh(xdr, args->fh, &hdr);
+	encode_fsinfo(xdr, args->bitmask, &hdr);
+	encode_nops(&hdr);
+}
+
+/*
+ * a PATHCONF request
+ */
+static void nfs4_xdr_enc_pathconf(struct rpc_rqst *req, struct xdr_stream *xdr,
+				  const void *data)
+{
+	const struct nfs4_pathconf_arg *args = data;
+	struct compound_hdr hdr = {
+		.minorversion = nfs4_xdr_minorversion(&args->seq_args),
+	};
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_sequence(xdr, &args->seq_args, &hdr);
+	encode_putfh(xdr, args->fh, &hdr);
+	encode_getattr(xdr, nfs4_pathconf_bitmap, args->bitmask,
+			ARRAY_SIZE(nfs4_pathconf_bitmap), &hdr);
+	encode_nops(&hdr);
+}
+
+/*
+ * a STATFS request
+ */
+static void nfs4_xdr_enc_statfs(struct rpc_rqst *req, struct xdr_stream *xdr,
+				const void *data)
+{
+	const struct nfs4_statfs_arg *args = data;
+	struct compound_hdr hdr = {
+		.minorversion = nfs4_xdr_minorversion(&args->seq_args),
+	};
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_sequence(xdr, &args->seq_args, &hdr);
+	encode_putfh(xdr, args->fh, &hdr);
+	encode_getattr(xdr, nfs4_statfs_bitmap, args->bitmask,
+			ARRAY_SIZE(nfs4_statfs_bitmap), &hdr);
+	encode_nops(&hdr);
+}
+
+/*
+ * GETATTR_BITMAP request
+ */
+static void nfs4_xdr_enc_server_caps(struct rpc_rqst *req,
+				     struct xdr_stream *xdr,
+				     const void *data)
+{
+	const struct nfs4_server_caps_arg *args = data;
+	const u32 *bitmask = args->bitmask;
+	struct compound_hdr hdr = {
+		.minorversion = nfs4_xdr_minorversion(&args->seq_args),
+	};
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_sequence(xdr, &args->seq_args, &hdr);
+	encode_putfh(xdr, args->fhandle, &hdr);
+	encode_getattr(xdr, bitmask, NULL, 3, &hdr);
+	encode_nops(&hdr);
+}
+
+/*
+ * a RENEW request
+ */
+static void nfs4_xdr_enc_renew(struct rpc_rqst *req, struct xdr_stream *xdr,
+			       const void *data)
+
+{
+	const struct nfs_client *clp = data;
+	struct compound_hdr hdr = {
+		.nops	= 0,
+	};
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_renew(xdr, clp->cl_clientid, &hdr);
+	encode_nops(&hdr);
+}
+
+/*
+ * a SETCLIENTID request
+ */
+static void nfs4_xdr_enc_setclientid(struct rpc_rqst *req,
+				     struct xdr_stream *xdr,
+				     const void *data)
+{
+	const struct nfs4_setclientid *sc = data;
+	struct compound_hdr hdr = {
+		.nops	= 0,
+	};
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_setclientid(xdr, sc, &hdr);
+	encode_nops(&hdr);
+}
+
+/*
+ * a SETCLIENTID_CONFIRM request
+ */
+static void nfs4_xdr_enc_setclientid_confirm(struct rpc_rqst *req,
+					     struct xdr_stream *xdr,
+					     const void *data)
+{
+	const struct nfs4_setclientid_res *arg = data;
+	struct compound_hdr hdr = {
+		.nops	= 0,
+	};
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_setclientid_confirm(xdr, arg, &hdr);
+	encode_nops(&hdr);
+}
+
+/*
+ * DELEGRETURN request
+ */
+static void nfs4_xdr_enc_delegreturn(struct rpc_rqst *req,
+				     struct xdr_stream *xdr,
+				     const void *data)
+{
+	const struct nfs4_delegreturnargs *args = data;
+	struct compound_hdr hdr = {
+		.minorversion = nfs4_xdr_minorversion(&args->seq_args),
+	};
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_sequence(xdr, &args->seq_args, &hdr);
+	encode_putfh(xdr, args->fhandle, &hdr);
+	if (args->lr_args)
+		encode_layoutreturn(xdr, args->lr_args, &hdr);
+	if (args->bitmask)
+		encode_getfattr(xdr, args->bitmask, &hdr);
+	encode_delegreturn(xdr, args->stateid, &hdr);
+	encode_nops(&hdr);
+}
+
+/*
+ * Encode FS_LOCATIONS request
+ */
+static void nfs4_xdr_enc_fs_locations(struct rpc_rqst *req,
+				      struct xdr_stream *xdr,
+				      const void *data)
+{
+	const struct nfs4_fs_locations_arg *args = data;
+	struct compound_hdr hdr = {
+		.minorversion = nfs4_xdr_minorversion(&args->seq_args),
+	};
+	uint32_t replen;
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_sequence(xdr, &args->seq_args, &hdr);
+	if (args->migration) {
+		encode_putfh(xdr, args->fh, &hdr);
+		replen = hdr.replen;
+		encode_fs_locations(xdr, args->bitmask, &hdr);
+		if (args->renew)
+			encode_renew(xdr, args->clientid, &hdr);
+	} else {
+		encode_putfh(xdr, args->dir_fh, &hdr);
+		encode_lookup(xdr, args->name, &hdr);
+		replen = hdr.replen;
+		encode_fs_locations(xdr, args->bitmask, &hdr);
+	}
+
+	rpc_prepare_reply_pages(req, (struct page **)&args->page, 0,
+				PAGE_SIZE, replen + 1);
+	encode_nops(&hdr);
+}
+
+/*
+ * Encode SECINFO request
+ */
+static void nfs4_xdr_enc_secinfo(struct rpc_rqst *req,
+				struct xdr_stream *xdr,
+				const void *data)
+{
+	const struct nfs4_secinfo_arg *args = data;
+	struct compound_hdr hdr = {
+		.minorversion = nfs4_xdr_minorversion(&args->seq_args),
+	};
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_sequence(xdr, &args->seq_args, &hdr);
+	encode_putfh(xdr, args->dir_fh, &hdr);
+	encode_secinfo(xdr, args->name, &hdr);
+	encode_nops(&hdr);
+}
+
+/*
+ * Encode FSID_PRESENT request
+ */
+static void nfs4_xdr_enc_fsid_present(struct rpc_rqst *req,
+				      struct xdr_stream *xdr,
+				      const void *data)
+{
+	const struct nfs4_fsid_present_arg *args = data;
+	struct compound_hdr hdr = {
+		.minorversion = nfs4_xdr_minorversion(&args->seq_args),
+	};
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_sequence(xdr, &args->seq_args, &hdr);
+	encode_putfh(xdr, args->fh, &hdr);
+	encode_getfh(xdr, &hdr);
+	if (args->renew)
+		encode_renew(xdr, args->clientid, &hdr);
+	encode_nops(&hdr);
+}
+
+#if defined(CONFIG_NFS_V4_1)
+/*
+ * BIND_CONN_TO_SESSION request
+ */
+static void nfs4_xdr_enc_bind_conn_to_session(struct rpc_rqst *req,
+				struct xdr_stream *xdr,
+				const void *data)
+{
+	const struct nfs41_bind_conn_to_session_args *args = data;
+	struct compound_hdr hdr = {
+		.minorversion = args->client->cl_mvops->minor_version,
+	};
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_bind_conn_to_session(xdr, args, &hdr);
+	encode_nops(&hdr);
+}
+
+/*
+ * EXCHANGE_ID request
+ */
+static void nfs4_xdr_enc_exchange_id(struct rpc_rqst *req,
+				     struct xdr_stream *xdr,
+				     const void *data)
+{
+	const struct nfs41_exchange_id_args *args = data;
+	struct compound_hdr hdr = {
+		.minorversion = args->client->cl_mvops->minor_version,
+	};
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_exchange_id(xdr, args, &hdr);
+	encode_nops(&hdr);
+}
+
+/*
+ * a CREATE_SESSION request
+ */
+static void nfs4_xdr_enc_create_session(struct rpc_rqst *req,
+					struct xdr_stream *xdr,
+					const void *data)
+{
+	const struct nfs41_create_session_args *args = data;
+	struct compound_hdr hdr = {
+		.minorversion = args->client->cl_mvops->minor_version,
+	};
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_create_session(xdr, args, &hdr);
+	encode_nops(&hdr);
+}
+
+/*
+ * a DESTROY_SESSION request
+ */
+static void nfs4_xdr_enc_destroy_session(struct rpc_rqst *req,
+					 struct xdr_stream *xdr,
+					 const void *data)
+{
+	const struct nfs4_session *session = data;
+	struct compound_hdr hdr = {
+		.minorversion = session->clp->cl_mvops->minor_version,
+	};
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_destroy_session(xdr, session, &hdr);
+	encode_nops(&hdr);
+}
+
+/*
+ * a DESTROY_CLIENTID request
+ */
+static void nfs4_xdr_enc_destroy_clientid(struct rpc_rqst *req,
+					 struct xdr_stream *xdr,
+					 const void *data)
+{
+	const struct nfs_client *clp = data;
+	struct compound_hdr hdr = {
+		.minorversion = clp->cl_mvops->minor_version,
+	};
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_destroy_clientid(xdr, clp->cl_clientid, &hdr);
+	encode_nops(&hdr);
+}
+
+/*
+ * a SEQUENCE request
+ */
+static void nfs4_xdr_enc_sequence(struct rpc_rqst *req, struct xdr_stream *xdr,
+				  const void *data)
+{
+	const struct nfs4_sequence_args *args = data;
+	struct compound_hdr hdr = {
+		.minorversion = nfs4_xdr_minorversion(args),
+	};
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_sequence(xdr, args, &hdr);
+	encode_nops(&hdr);
+}
+
+#endif
+
+/*
+ * a GET_LEASE_TIME request
+ */
+static void nfs4_xdr_enc_get_lease_time(struct rpc_rqst *req,
+					struct xdr_stream *xdr,
+					const void *data)
+{
+	const struct nfs4_get_lease_time_args *args = data;
+	struct compound_hdr hdr = {
+		.minorversion = nfs4_xdr_minorversion(&args->la_seq_args),
+	};
+	const u32 lease_bitmap[3] = { FATTR4_WORD0_LEASE_TIME };
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_sequence(xdr, &args->la_seq_args, &hdr);
+	encode_putrootfh(xdr, &hdr);
+	encode_fsinfo(xdr, lease_bitmap, &hdr);
+	encode_nops(&hdr);
+}
+
+#ifdef CONFIG_NFS_V4_1
+
+/*
+ * a RECLAIM_COMPLETE request
+ */
+static void nfs4_xdr_enc_reclaim_complete(struct rpc_rqst *req,
+					  struct xdr_stream *xdr,
+					  const void *data)
+{
+	const struct nfs41_reclaim_complete_args *args = data;
+	struct compound_hdr hdr = {
+		.minorversion = nfs4_xdr_minorversion(&args->seq_args)
+	};
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_sequence(xdr, &args->seq_args, &hdr);
+	encode_reclaim_complete(xdr, args, &hdr);
+	encode_nops(&hdr);
+}
+
+/*
+ * Encode GETDEVICEINFO request
+ */
+static void nfs4_xdr_enc_getdeviceinfo(struct rpc_rqst *req,
+				       struct xdr_stream *xdr,
+				       const void *data)
+{
+	const struct nfs4_getdeviceinfo_args *args = data;
+	struct compound_hdr hdr = {
+		.minorversion = nfs4_xdr_minorversion(&args->seq_args),
+	};
+	uint32_t replen;
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_sequence(xdr, &args->seq_args, &hdr);
+
+	replen = hdr.replen + op_decode_hdr_maxsz;
+
+	encode_getdeviceinfo(xdr, args, &hdr);
+
+	/* set up reply kvec. device_addr4 opaque data is read into the
+	 * pages */
+	rpc_prepare_reply_pages(req, args->pdev->pages, args->pdev->pgbase,
+				args->pdev->pglen, replen + 2 + 1);
+	encode_nops(&hdr);
+}
+
+/*
+ *  Encode LAYOUTGET request
+ */
+static void nfs4_xdr_enc_layoutget(struct rpc_rqst *req,
+				   struct xdr_stream *xdr,
+				   const void *data)
+{
+	const struct nfs4_layoutget_args *args = data;
+	struct compound_hdr hdr = {
+		.minorversion = nfs4_xdr_minorversion(&args->seq_args),
+	};
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_sequence(xdr, &args->seq_args, &hdr);
+	encode_putfh(xdr, NFS_FH(args->inode), &hdr);
+	encode_layoutget(xdr, args, &hdr);
+
+	rpc_prepare_reply_pages(req, args->layout.pages, 0,
+				args->layout.pglen, hdr.replen);
+	encode_nops(&hdr);
+}
+
+/*
+ *  Encode LAYOUTCOMMIT request
+ */
+static void nfs4_xdr_enc_layoutcommit(struct rpc_rqst *req,
+				      struct xdr_stream *xdr,
+				      const void *priv)
+{
+	const struct nfs4_layoutcommit_args *args = priv;
+	struct nfs4_layoutcommit_data *data =
+		container_of(args, struct nfs4_layoutcommit_data, args);
+	struct compound_hdr hdr = {
+		.minorversion = nfs4_xdr_minorversion(&args->seq_args),
+	};
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_sequence(xdr, &args->seq_args, &hdr);
+	encode_putfh(xdr, NFS_FH(args->inode), &hdr);
+	encode_layoutcommit(xdr, data->args.inode, args, &hdr);
+	encode_getfattr(xdr, args->bitmask, &hdr);
+	encode_nops(&hdr);
+}
+
+/*
+ * Encode LAYOUTRETURN request
+ */
+static void nfs4_xdr_enc_layoutreturn(struct rpc_rqst *req,
+				      struct xdr_stream *xdr,
+				      const void *data)
+{
+	const struct nfs4_layoutreturn_args *args = data;
+	struct compound_hdr hdr = {
+		.minorversion = nfs4_xdr_minorversion(&args->seq_args),
+	};
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_sequence(xdr, &args->seq_args, &hdr);
+	encode_putfh(xdr, NFS_FH(args->inode), &hdr);
+	encode_layoutreturn(xdr, args, &hdr);
+	encode_nops(&hdr);
+}
+
+/*
+ * Encode SECINFO_NO_NAME request
+ */
+static void nfs4_xdr_enc_secinfo_no_name(struct rpc_rqst *req,
+					struct xdr_stream *xdr,
+					const void *data)
+{
+	const struct nfs41_secinfo_no_name_args *args = data;
+	struct compound_hdr hdr = {
+		.minorversion = nfs4_xdr_minorversion(&args->seq_args),
+	};
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_sequence(xdr, &args->seq_args, &hdr);
+	encode_putrootfh(xdr, &hdr);
+	encode_secinfo_no_name(xdr, args, &hdr);
+	encode_nops(&hdr);
+}
+
+/*
+ *  Encode TEST_STATEID request
+ */
+static void nfs4_xdr_enc_test_stateid(struct rpc_rqst *req,
+				      struct xdr_stream *xdr,
+				      const void *data)
+{
+	const struct nfs41_test_stateid_args *args = data;
+	struct compound_hdr hdr = {
+		.minorversion = nfs4_xdr_minorversion(&args->seq_args),
+	};
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_sequence(xdr, &args->seq_args, &hdr);
+	encode_test_stateid(xdr, args, &hdr);
+	encode_nops(&hdr);
+}
+
+/*
+ *  Encode FREE_STATEID request
+ */
+static void nfs4_xdr_enc_free_stateid(struct rpc_rqst *req,
+				     struct xdr_stream *xdr,
+				     const void *data)
+{
+	const struct nfs41_free_stateid_args *args = data;
+	struct compound_hdr hdr = {
+		.minorversion = nfs4_xdr_minorversion(&args->seq_args),
+	};
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_sequence(xdr, &args->seq_args, &hdr);
+	encode_free_stateid(xdr, args, &hdr);
+	encode_nops(&hdr);
+}
+#endif /* CONFIG_NFS_V4_1 */
+
+static int decode_opaque_inline(struct xdr_stream *xdr, unsigned int *len, char **string)
+{
+	ssize_t ret = xdr_stream_decode_opaque_inline(xdr, (void **)string,
+			NFS4_OPAQUE_LIMIT);
+	if (unlikely(ret < 0))
+		return -EIO;
+	*len = ret;
+	return 0;
+}
+
+static int decode_compound_hdr(struct xdr_stream *xdr, struct compound_hdr *hdr)
+{
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, 8);
+	if (unlikely(!p))
+		return -EIO;
+	hdr->status = be32_to_cpup(p++);
+	hdr->taglen = be32_to_cpup(p);
+
+	p = xdr_inline_decode(xdr, hdr->taglen + 4);
+	if (unlikely(!p))
+		return -EIO;
+	hdr->tag = (char *)p;
+	p += XDR_QUADLEN(hdr->taglen);
+	hdr->nops = be32_to_cpup(p);
+	if (unlikely(hdr->nops < 1))
+		return nfs4_stat_to_errno(hdr->status);
+	return 0;
+}
+
+static bool __decode_op_hdr(struct xdr_stream *xdr, enum nfs_opnum4 expected,
+		int *nfs_retval)
+{
+	__be32 *p;
+	uint32_t opnum;
+	int32_t nfserr;
+
+	p = xdr_inline_decode(xdr, 8);
+	if (unlikely(!p))
+		goto out_overflow;
+	opnum = be32_to_cpup(p++);
+	if (unlikely(opnum != expected))
+		goto out_bad_operation;
+	if (unlikely(*p != cpu_to_be32(NFS_OK)))
+		goto out_status;
+	*nfs_retval = 0;
+	return true;
+out_status:
+	nfserr = be32_to_cpup(p);
+	trace_nfs4_xdr_status(xdr, opnum, nfserr);
+	*nfs_retval = nfs4_stat_to_errno(nfserr);
+	return true;
+out_bad_operation:
+	dprintk("nfs: Server returned operation"
+		" %d but we issued a request for %d\n",
+			opnum, expected);
+	*nfs_retval = -EREMOTEIO;
+	return false;
+out_overflow:
+	*nfs_retval = -EIO;
+	return false;
+}
+
+static int decode_op_hdr(struct xdr_stream *xdr, enum nfs_opnum4 expected)
+{
+	int retval;
+
+	__decode_op_hdr(xdr, expected, &retval);
+	return retval;
+}
+
+/* Dummy routine */
+static int decode_ace(struct xdr_stream *xdr, void *ace)
+{
+	__be32 *p;
+	unsigned int strlen;
+	char *str;
+
+	p = xdr_inline_decode(xdr, 12);
+	if (unlikely(!p))
+		return -EIO;
+	return decode_opaque_inline(xdr, &strlen, &str);
+}
+
+static ssize_t
+decode_bitmap4(struct xdr_stream *xdr, uint32_t *bitmap, size_t sz)
+{
+	ssize_t ret;
+
+	ret = xdr_stream_decode_uint32_array(xdr, bitmap, sz);
+	if (likely(ret >= 0))
+		return ret;
+	if (ret != -EMSGSIZE)
+		return -EIO;
+	return sz;
+}
+
+static int decode_attr_bitmap(struct xdr_stream *xdr, uint32_t *bitmap)
+{
+	ssize_t ret;
+	ret = decode_bitmap4(xdr, bitmap, 3);
+	return ret < 0 ? ret : 0;
+}
+
+static int decode_attr_length(struct xdr_stream *xdr, uint32_t *attrlen, unsigned int *savep)
+{
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(!p))
+		return -EIO;
+	*attrlen = be32_to_cpup(p);
+	*savep = xdr_stream_pos(xdr);
+	return 0;
+}
+
+static int decode_attr_supported(struct xdr_stream *xdr, uint32_t *bitmap, uint32_t *bitmask)
+{
+	if (likely(bitmap[0] & FATTR4_WORD0_SUPPORTED_ATTRS)) {
+		int ret;
+		ret = decode_attr_bitmap(xdr, bitmask);
+		if (unlikely(ret < 0))
+			return ret;
+		bitmap[0] &= ~FATTR4_WORD0_SUPPORTED_ATTRS;
+	} else
+		bitmask[0] = bitmask[1] = bitmask[2] = 0;
+	dprintk("%s: bitmask=%08x:%08x:%08x\n", __func__,
+		bitmask[0], bitmask[1], bitmask[2]);
+	return 0;
+}
+
+static int decode_attr_type(struct xdr_stream *xdr, uint32_t *bitmap, uint32_t *type)
+{
+	__be32 *p;
+	int ret = 0;
+
+	*type = 0;
+	if (unlikely(bitmap[0] & (FATTR4_WORD0_TYPE - 1U)))
+		return -EIO;
+	if (likely(bitmap[0] & FATTR4_WORD0_TYPE)) {
+		p = xdr_inline_decode(xdr, 4);
+		if (unlikely(!p))
+			return -EIO;
+		*type = be32_to_cpup(p);
+		if (*type < NF4REG || *type > NF4NAMEDATTR) {
+			dprintk("%s: bad type %d\n", __func__, *type);
+			return -EIO;
+		}
+		bitmap[0] &= ~FATTR4_WORD0_TYPE;
+		ret = NFS_ATTR_FATTR_TYPE;
+	}
+	dprintk("%s: type=0%o\n", __func__, nfs_type2fmt[*type]);
+	return ret;
+}
+
+static int decode_attr_fh_expire_type(struct xdr_stream *xdr,
+				      uint32_t *bitmap, uint32_t *type)
+{
+	__be32 *p;
+
+	*type = 0;
+	if (unlikely(bitmap[0] & (FATTR4_WORD0_FH_EXPIRE_TYPE - 1U)))
+		return -EIO;
+	if (likely(bitmap[0] & FATTR4_WORD0_FH_EXPIRE_TYPE)) {
+		p = xdr_inline_decode(xdr, 4);
+		if (unlikely(!p))
+			return -EIO;
+		*type = be32_to_cpup(p);
+		bitmap[0] &= ~FATTR4_WORD0_FH_EXPIRE_TYPE;
+	}
+	dprintk("%s: expire type=0x%x\n", __func__, *type);
+	return 0;
+}
+
+static int decode_attr_change(struct xdr_stream *xdr, uint32_t *bitmap, uint64_t *change)
+{
+	__be32 *p;
+	int ret = 0;
+
+	*change = 0;
+	if (unlikely(bitmap[0] & (FATTR4_WORD0_CHANGE - 1U)))
+		return -EIO;
+	if (likely(bitmap[0] & FATTR4_WORD0_CHANGE)) {
+		p = xdr_inline_decode(xdr, 8);
+		if (unlikely(!p))
+			return -EIO;
+		xdr_decode_hyper(p, change);
+		bitmap[0] &= ~FATTR4_WORD0_CHANGE;
+		ret = NFS_ATTR_FATTR_CHANGE;
+	}
+	dprintk("%s: change attribute=%Lu\n", __func__,
+			(unsigned long long)*change);
+	return ret;
+}
+
+static int decode_attr_size(struct xdr_stream *xdr, uint32_t *bitmap, uint64_t *size)
+{
+	__be32 *p;
+	int ret = 0;
+
+	*size = 0;
+	if (unlikely(bitmap[0] & (FATTR4_WORD0_SIZE - 1U)))
+		return -EIO;
+	if (likely(bitmap[0] & FATTR4_WORD0_SIZE)) {
+		p = xdr_inline_decode(xdr, 8);
+		if (unlikely(!p))
+			return -EIO;
+		xdr_decode_hyper(p, size);
+		bitmap[0] &= ~FATTR4_WORD0_SIZE;
+		ret = NFS_ATTR_FATTR_SIZE;
+	}
+	dprintk("%s: file size=%Lu\n", __func__, (unsigned long long)*size);
+	return ret;
+}
+
+static int decode_attr_link_support(struct xdr_stream *xdr, uint32_t *bitmap, uint32_t *res)
+{
+	__be32 *p;
+
+	*res = 0;
+	if (unlikely(bitmap[0] & (FATTR4_WORD0_LINK_SUPPORT - 1U)))
+		return -EIO;
+	if (likely(bitmap[0] & FATTR4_WORD0_LINK_SUPPORT)) {
+		p = xdr_inline_decode(xdr, 4);
+		if (unlikely(!p))
+			return -EIO;
+		*res = be32_to_cpup(p);
+		bitmap[0] &= ~FATTR4_WORD0_LINK_SUPPORT;
+	}
+	dprintk("%s: link support=%s\n", __func__, *res == 0 ? "false" : "true");
+	return 0;
+}
+
+static int decode_attr_symlink_support(struct xdr_stream *xdr, uint32_t *bitmap, uint32_t *res)
+{
+	__be32 *p;
+
+	*res = 0;
+	if (unlikely(bitmap[0] & (FATTR4_WORD0_SYMLINK_SUPPORT - 1U)))
+		return -EIO;
+	if (likely(bitmap[0] & FATTR4_WORD0_SYMLINK_SUPPORT)) {
+		p = xdr_inline_decode(xdr, 4);
+		if (unlikely(!p))
+			return -EIO;
+		*res = be32_to_cpup(p);
+		bitmap[0] &= ~FATTR4_WORD0_SYMLINK_SUPPORT;
+	}
+	dprintk("%s: symlink support=%s\n", __func__, *res == 0 ? "false" : "true");
+	return 0;
+}
+
+static int decode_attr_fsid(struct xdr_stream *xdr, uint32_t *bitmap, struct nfs_fsid *fsid)
+{
+	__be32 *p;
+	int ret = 0;
+
+	fsid->major = 0;
+	fsid->minor = 0;
+	if (unlikely(bitmap[0] & (FATTR4_WORD0_FSID - 1U)))
+		return -EIO;
+	if (likely(bitmap[0] & FATTR4_WORD0_FSID)) {
+		p = xdr_inline_decode(xdr, 16);
+		if (unlikely(!p))
+			return -EIO;
+		p = xdr_decode_hyper(p, &fsid->major);
+		xdr_decode_hyper(p, &fsid->minor);
+		bitmap[0] &= ~FATTR4_WORD0_FSID;
+		ret = NFS_ATTR_FATTR_FSID;
+	}
+	dprintk("%s: fsid=(0x%Lx/0x%Lx)\n", __func__,
+			(unsigned long long)fsid->major,
+			(unsigned long long)fsid->minor);
+	return ret;
+}
+
+static int decode_attr_lease_time(struct xdr_stream *xdr, uint32_t *bitmap, uint32_t *res)
+{
+	__be32 *p;
+
+	*res = 60;
+	if (unlikely(bitmap[0] & (FATTR4_WORD0_LEASE_TIME - 1U)))
+		return -EIO;
+	if (likely(bitmap[0] & FATTR4_WORD0_LEASE_TIME)) {
+		p = xdr_inline_decode(xdr, 4);
+		if (unlikely(!p))
+			return -EIO;
+		*res = be32_to_cpup(p);
+		bitmap[0] &= ~FATTR4_WORD0_LEASE_TIME;
+	}
+	dprintk("%s: lease time=%u\n", __func__, (unsigned int)*res);
+	return 0;
+}
+
+static int decode_attr_error(struct xdr_stream *xdr, uint32_t *bitmap, int32_t *res)
+{
+	__be32 *p;
+
+	if (unlikely(bitmap[0] & (FATTR4_WORD0_RDATTR_ERROR - 1U)))
+		return -EIO;
+	if (likely(bitmap[0] & FATTR4_WORD0_RDATTR_ERROR)) {
+		p = xdr_inline_decode(xdr, 4);
+		if (unlikely(!p))
+			return -EIO;
+		bitmap[0] &= ~FATTR4_WORD0_RDATTR_ERROR;
+		*res = -be32_to_cpup(p);
+	}
+	return 0;
+}
+
+static int decode_attr_exclcreat_supported(struct xdr_stream *xdr,
+				 uint32_t *bitmap, uint32_t *bitmask)
+{
+	if (likely(bitmap[2] & FATTR4_WORD2_SUPPATTR_EXCLCREAT)) {
+		int ret;
+		ret = decode_attr_bitmap(xdr, bitmask);
+		if (unlikely(ret < 0))
+			return ret;
+		bitmap[2] &= ~FATTR4_WORD2_SUPPATTR_EXCLCREAT;
+	} else
+		bitmask[0] = bitmask[1] = bitmask[2] = 0;
+	dprintk("%s: bitmask=%08x:%08x:%08x\n", __func__,
+		bitmask[0], bitmask[1], bitmask[2]);
+	return 0;
+}
+
+static int decode_attr_filehandle(struct xdr_stream *xdr, uint32_t *bitmap, struct nfs_fh *fh)
+{
+	__be32 *p;
+	u32 len;
+
+	if (fh != NULL)
+		memset(fh, 0, sizeof(*fh));
+
+	if (unlikely(bitmap[0] & (FATTR4_WORD0_FILEHANDLE - 1U)))
+		return -EIO;
+	if (likely(bitmap[0] & FATTR4_WORD0_FILEHANDLE)) {
+		p = xdr_inline_decode(xdr, 4);
+		if (unlikely(!p))
+			return -EIO;
+		len = be32_to_cpup(p);
+		if (len > NFS4_FHSIZE)
+			return -EIO;
+		p = xdr_inline_decode(xdr, len);
+		if (unlikely(!p))
+			return -EIO;
+		if (fh != NULL) {
+			memcpy(fh->data, p, len);
+			fh->size = len;
+		}
+		bitmap[0] &= ~FATTR4_WORD0_FILEHANDLE;
+	}
+	return 0;
+}
+
+static int decode_attr_aclsupport(struct xdr_stream *xdr, uint32_t *bitmap, uint32_t *res)
+{
+	__be32 *p;
+
+	*res = 0;
+	if (unlikely(bitmap[0] & (FATTR4_WORD0_ACLSUPPORT - 1U)))
+		return -EIO;
+	if (likely(bitmap[0] & FATTR4_WORD0_ACLSUPPORT)) {
+		p = xdr_inline_decode(xdr, 4);
+		if (unlikely(!p))
+			return -EIO;
+		*res = be32_to_cpup(p);
+		bitmap[0] &= ~FATTR4_WORD0_ACLSUPPORT;
+	}
+	dprintk("%s: ACLs supported=%u\n", __func__, (unsigned int)*res);
+	return 0;
+}
+
+static int decode_attr_fileid(struct xdr_stream *xdr, uint32_t *bitmap, uint64_t *fileid)
+{
+	__be32 *p;
+	int ret = 0;
+
+	*fileid = 0;
+	if (unlikely(bitmap[0] & (FATTR4_WORD0_FILEID - 1U)))
+		return -EIO;
+	if (likely(bitmap[0] & FATTR4_WORD0_FILEID)) {
+		p = xdr_inline_decode(xdr, 8);
+		if (unlikely(!p))
+			return -EIO;
+		xdr_decode_hyper(p, fileid);
+		bitmap[0] &= ~FATTR4_WORD0_FILEID;
+		ret = NFS_ATTR_FATTR_FILEID;
+	}
+	dprintk("%s: fileid=%Lu\n", __func__, (unsigned long long)*fileid);
+	return ret;
+}
+
+static int decode_attr_mounted_on_fileid(struct xdr_stream *xdr, uint32_t *bitmap, uint64_t *fileid)
+{
+	__be32 *p;
+	int ret = 0;
+
+	*fileid = 0;
+	if (unlikely(bitmap[1] & (FATTR4_WORD1_MOUNTED_ON_FILEID - 1U)))
+		return -EIO;
+	if (likely(bitmap[1] & FATTR4_WORD1_MOUNTED_ON_FILEID)) {
+		p = xdr_inline_decode(xdr, 8);
+		if (unlikely(!p))
+			return -EIO;
+		xdr_decode_hyper(p, fileid);
+		bitmap[1] &= ~FATTR4_WORD1_MOUNTED_ON_FILEID;
+		ret = NFS_ATTR_FATTR_MOUNTED_ON_FILEID;
+	}
+	dprintk("%s: fileid=%Lu\n", __func__, (unsigned long long)*fileid);
+	return ret;
+}
+
+static int decode_attr_files_avail(struct xdr_stream *xdr, uint32_t *bitmap, uint64_t *res)
+{
+	__be32 *p;
+	int status = 0;
+
+	*res = 0;
+	if (unlikely(bitmap[0] & (FATTR4_WORD0_FILES_AVAIL - 1U)))
+		return -EIO;
+	if (likely(bitmap[0] & FATTR4_WORD0_FILES_AVAIL)) {
+		p = xdr_inline_decode(xdr, 8);
+		if (unlikely(!p))
+			return -EIO;
+		xdr_decode_hyper(p, res);
+		bitmap[0] &= ~FATTR4_WORD0_FILES_AVAIL;
+	}
+	dprintk("%s: files avail=%Lu\n", __func__, (unsigned long long)*res);
+	return status;
+}
+
+static int decode_attr_files_free(struct xdr_stream *xdr, uint32_t *bitmap, uint64_t *res)
+{
+	__be32 *p;
+	int status = 0;
+
+	*res = 0;
+	if (unlikely(bitmap[0] & (FATTR4_WORD0_FILES_FREE - 1U)))
+		return -EIO;
+	if (likely(bitmap[0] & FATTR4_WORD0_FILES_FREE)) {
+		p = xdr_inline_decode(xdr, 8);
+		if (unlikely(!p))
+			return -EIO;
+		xdr_decode_hyper(p, res);
+		bitmap[0] &= ~FATTR4_WORD0_FILES_FREE;
+	}
+	dprintk("%s: files free=%Lu\n", __func__, (unsigned long long)*res);
+	return status;
+}
+
+static int decode_attr_files_total(struct xdr_stream *xdr, uint32_t *bitmap, uint64_t *res)
+{
+	__be32 *p;
+	int status = 0;
+
+	*res = 0;
+	if (unlikely(bitmap[0] & (FATTR4_WORD0_FILES_TOTAL - 1U)))
+		return -EIO;
+	if (likely(bitmap[0] & FATTR4_WORD0_FILES_TOTAL)) {
+		p = xdr_inline_decode(xdr, 8);
+		if (unlikely(!p))
+			return -EIO;
+		xdr_decode_hyper(p, res);
+		bitmap[0] &= ~FATTR4_WORD0_FILES_TOTAL;
+	}
+	dprintk("%s: files total=%Lu\n", __func__, (unsigned long long)*res);
+	return status;
+}
+
+static int decode_pathname(struct xdr_stream *xdr, struct nfs4_pathname *path)
+{
+	u32 n;
+	__be32 *p;
+	int status = 0;
+
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(!p))
+		return -EIO;
+	n = be32_to_cpup(p);
+	if (n == 0)
+		goto root_path;
+	dprintk("pathname4: ");
+	if (n > NFS4_PATHNAME_MAXCOMPONENTS) {
+		dprintk("cannot parse %d components in path\n", n);
+		goto out_eio;
+	}
+	for (path->ncomponents = 0; path->ncomponents < n; path->ncomponents++) {
+		struct nfs4_string *component = &path->components[path->ncomponents];
+		status = decode_opaque_inline(xdr, &component->len, &component->data);
+		if (unlikely(status != 0))
+			goto out_eio;
+		ifdebug (XDR)
+			pr_cont("%s%.*s ",
+				(path->ncomponents != n ? "/ " : ""),
+				component->len, component->data);
+	}
+out:
+	return status;
+root_path:
+/* a root pathname is sent as a zero component4 */
+	path->ncomponents = 1;
+	path->components[0].len=0;
+	path->components[0].data=NULL;
+	dprintk("pathname4: /\n");
+	goto out;
+out_eio:
+	dprintk(" status %d", status);
+	status = -EIO;
+	goto out;
+}
+
+static int decode_attr_fs_locations(struct xdr_stream *xdr, uint32_t *bitmap, struct nfs4_fs_locations *res)
+{
+	int n;
+	__be32 *p;
+	int status = -EIO;
+
+	if (unlikely(bitmap[0] & (FATTR4_WORD0_FS_LOCATIONS -1U)))
+		goto out;
+	status = 0;
+	if (unlikely(!(bitmap[0] & FATTR4_WORD0_FS_LOCATIONS)))
+		goto out;
+	bitmap[0] &= ~FATTR4_WORD0_FS_LOCATIONS;
+	status = -EIO;
+	/* Ignore borken servers that return unrequested attrs */
+	if (unlikely(res == NULL))
+		goto out;
+	dprintk("%s: fsroot:\n", __func__);
+	status = decode_pathname(xdr, &res->fs_path);
+	if (unlikely(status != 0))
+		goto out;
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(!p))
+		goto out_eio;
+	n = be32_to_cpup(p);
+	for (res->nlocations = 0; res->nlocations < n; res->nlocations++) {
+		u32 m;
+		struct nfs4_fs_location *loc;
+
+		if (res->nlocations == NFS4_FS_LOCATIONS_MAXENTRIES)
+			break;
+		loc = &res->locations[res->nlocations];
+		p = xdr_inline_decode(xdr, 4);
+		if (unlikely(!p))
+			goto out_eio;
+		m = be32_to_cpup(p);
+
+		dprintk("%s: servers:\n", __func__);
+		for (loc->nservers = 0; loc->nservers < m; loc->nservers++) {
+			struct nfs4_string *server;
+
+			if (loc->nservers == NFS4_FS_LOCATION_MAXSERVERS) {
+				unsigned int i;
+				dprintk("%s: using first %u of %u servers "
+					"returned for location %u\n",
+						__func__,
+						NFS4_FS_LOCATION_MAXSERVERS,
+						m, res->nlocations);
+				for (i = loc->nservers; i < m; i++) {
+					unsigned int len;
+					char *data;
+					status = decode_opaque_inline(xdr, &len, &data);
+					if (unlikely(status != 0))
+						goto out_eio;
+				}
+				break;
+			}
+			server = &loc->servers[loc->nservers];
+			status = decode_opaque_inline(xdr, &server->len, &server->data);
+			if (unlikely(status != 0))
+				goto out_eio;
+			dprintk("%s ", server->data);
+		}
+		status = decode_pathname(xdr, &loc->rootpath);
+		if (unlikely(status != 0))
+			goto out_eio;
+	}
+	if (res->nlocations != 0)
+		status = NFS_ATTR_FATTR_V4_LOCATIONS;
+out:
+	dprintk("%s: fs_locations done, error = %d\n", __func__, status);
+	return status;
+out_eio:
+	status = -EIO;
+	goto out;
+}
+
+static int decode_attr_maxfilesize(struct xdr_stream *xdr, uint32_t *bitmap, uint64_t *res)
+{
+	__be32 *p;
+	int status = 0;
+
+	*res = 0;
+	if (unlikely(bitmap[0] & (FATTR4_WORD0_MAXFILESIZE - 1U)))
+		return -EIO;
+	if (likely(bitmap[0] & FATTR4_WORD0_MAXFILESIZE)) {
+		p = xdr_inline_decode(xdr, 8);
+		if (unlikely(!p))
+			return -EIO;
+		xdr_decode_hyper(p, res);
+		bitmap[0] &= ~FATTR4_WORD0_MAXFILESIZE;
+	}
+	dprintk("%s: maxfilesize=%Lu\n", __func__, (unsigned long long)*res);
+	return status;
+}
+
+static int decode_attr_maxlink(struct xdr_stream *xdr, uint32_t *bitmap, uint32_t *maxlink)
+{
+	__be32 *p;
+	int status = 0;
+
+	*maxlink = 1;
+	if (unlikely(bitmap[0] & (FATTR4_WORD0_MAXLINK - 1U)))
+		return -EIO;
+	if (likely(bitmap[0] & FATTR4_WORD0_MAXLINK)) {
+		p = xdr_inline_decode(xdr, 4);
+		if (unlikely(!p))
+			return -EIO;
+		*maxlink = be32_to_cpup(p);
+		bitmap[0] &= ~FATTR4_WORD0_MAXLINK;
+	}
+	dprintk("%s: maxlink=%u\n", __func__, *maxlink);
+	return status;
+}
+
+static int decode_attr_maxname(struct xdr_stream *xdr, uint32_t *bitmap, uint32_t *maxname)
+{
+	__be32 *p;
+	int status = 0;
+
+	*maxname = 1024;
+	if (unlikely(bitmap[0] & (FATTR4_WORD0_MAXNAME - 1U)))
+		return -EIO;
+	if (likely(bitmap[0] & FATTR4_WORD0_MAXNAME)) {
+		p = xdr_inline_decode(xdr, 4);
+		if (unlikely(!p))
+			return -EIO;
+		*maxname = be32_to_cpup(p);
+		bitmap[0] &= ~FATTR4_WORD0_MAXNAME;
+	}
+	dprintk("%s: maxname=%u\n", __func__, *maxname);
+	return status;
+}
+
+static int decode_attr_maxread(struct xdr_stream *xdr, uint32_t *bitmap, uint32_t *res)
+{
+	__be32 *p;
+	int status = 0;
+
+	*res = 1024;
+	if (unlikely(bitmap[0] & (FATTR4_WORD0_MAXREAD - 1U)))
+		return -EIO;
+	if (likely(bitmap[0] & FATTR4_WORD0_MAXREAD)) {
+		uint64_t maxread;
+		p = xdr_inline_decode(xdr, 8);
+		if (unlikely(!p))
+			return -EIO;
+		xdr_decode_hyper(p, &maxread);
+		if (maxread > 0x7FFFFFFF)
+			maxread = 0x7FFFFFFF;
+		*res = (uint32_t)maxread;
+		bitmap[0] &= ~FATTR4_WORD0_MAXREAD;
+	}
+	dprintk("%s: maxread=%lu\n", __func__, (unsigned long)*res);
+	return status;
+}
+
+static int decode_attr_maxwrite(struct xdr_stream *xdr, uint32_t *bitmap, uint32_t *res)
+{
+	__be32 *p;
+	int status = 0;
+
+	*res = 1024;
+	if (unlikely(bitmap[0] & (FATTR4_WORD0_MAXWRITE - 1U)))
+		return -EIO;
+	if (likely(bitmap[0] & FATTR4_WORD0_MAXWRITE)) {
+		uint64_t maxwrite;
+		p = xdr_inline_decode(xdr, 8);
+		if (unlikely(!p))
+			return -EIO;
+		xdr_decode_hyper(p, &maxwrite);
+		if (maxwrite > 0x7FFFFFFF)
+			maxwrite = 0x7FFFFFFF;
+		*res = (uint32_t)maxwrite;
+		bitmap[0] &= ~FATTR4_WORD0_MAXWRITE;
+	}
+	dprintk("%s: maxwrite=%lu\n", __func__, (unsigned long)*res);
+	return status;
+}
+
+static int decode_attr_mode(struct xdr_stream *xdr, uint32_t *bitmap, umode_t *mode)
+{
+	uint32_t tmp;
+	__be32 *p;
+	int ret = 0;
+
+	*mode = 0;
+	if (unlikely(bitmap[1] & (FATTR4_WORD1_MODE - 1U)))
+		return -EIO;
+	if (likely(bitmap[1] & FATTR4_WORD1_MODE)) {
+		p = xdr_inline_decode(xdr, 4);
+		if (unlikely(!p))
+			return -EIO;
+		tmp = be32_to_cpup(p);
+		*mode = tmp & ~S_IFMT;
+		bitmap[1] &= ~FATTR4_WORD1_MODE;
+		ret = NFS_ATTR_FATTR_MODE;
+	}
+	dprintk("%s: file mode=0%o\n", __func__, (unsigned int)*mode);
+	return ret;
+}
+
+static int decode_attr_nlink(struct xdr_stream *xdr, uint32_t *bitmap, uint32_t *nlink)
+{
+	__be32 *p;
+	int ret = 0;
+
+	*nlink = 1;
+	if (unlikely(bitmap[1] & (FATTR4_WORD1_NUMLINKS - 1U)))
+		return -EIO;
+	if (likely(bitmap[1] & FATTR4_WORD1_NUMLINKS)) {
+		p = xdr_inline_decode(xdr, 4);
+		if (unlikely(!p))
+			return -EIO;
+		*nlink = be32_to_cpup(p);
+		bitmap[1] &= ~FATTR4_WORD1_NUMLINKS;
+		ret = NFS_ATTR_FATTR_NLINK;
+	}
+	dprintk("%s: nlink=%u\n", __func__, (unsigned int)*nlink);
+	return ret;
+}
+
+static ssize_t decode_nfs4_string(struct xdr_stream *xdr,
+		struct nfs4_string *name, gfp_t gfp_flags)
+{
+	ssize_t ret;
+
+	ret = xdr_stream_decode_string_dup(xdr, &name->data,
+			XDR_MAX_NETOBJ, gfp_flags);
+	name->len = 0;
+	if (ret > 0)
+		name->len = ret;
+	return ret;
+}
+
+static int decode_attr_owner(struct xdr_stream *xdr, uint32_t *bitmap,
+		const struct nfs_server *server, kuid_t *uid,
+		struct nfs4_string *owner_name)
+{
+	ssize_t len;
+	char *p;
+
+	*uid = make_kuid(&init_user_ns, -2);
+	if (unlikely(bitmap[1] & (FATTR4_WORD1_OWNER - 1U)))
+		return -EIO;
+	if (!(bitmap[1] & FATTR4_WORD1_OWNER))
+		return 0;
+	bitmap[1] &= ~FATTR4_WORD1_OWNER;
+
+	if (owner_name != NULL) {
+		len = decode_nfs4_string(xdr, owner_name, GFP_NOIO);
+		if (len <= 0)
+			goto out;
+		dprintk("%s: name=%s\n", __func__, owner_name->data);
+		return NFS_ATTR_FATTR_OWNER_NAME;
+	} else {
+		len = xdr_stream_decode_opaque_inline(xdr, (void **)&p,
+				XDR_MAX_NETOBJ);
+		if (len <= 0 || nfs_map_name_to_uid(server, p, len, uid) != 0)
+			goto out;
+		dprintk("%s: uid=%d\n", __func__, (int)from_kuid(&init_user_ns, *uid));
+		return NFS_ATTR_FATTR_OWNER;
+	}
+out:
+	if (len == -EBADMSG)
+		return -EIO;
+	return 0;
+}
+
+static int decode_attr_group(struct xdr_stream *xdr, uint32_t *bitmap,
+		const struct nfs_server *server, kgid_t *gid,
+		struct nfs4_string *group_name)
+{
+	ssize_t len;
+	char *p;
+
+	*gid = make_kgid(&init_user_ns, -2);
+	if (unlikely(bitmap[1] & (FATTR4_WORD1_OWNER_GROUP - 1U)))
+		return -EIO;
+	if (!(bitmap[1] & FATTR4_WORD1_OWNER_GROUP))
+		return 0;
+	bitmap[1] &= ~FATTR4_WORD1_OWNER_GROUP;
+
+	if (group_name != NULL) {
+		len = decode_nfs4_string(xdr, group_name, GFP_NOIO);
+		if (len <= 0)
+			goto out;
+		dprintk("%s: name=%s\n", __func__, group_name->data);
+		return NFS_ATTR_FATTR_GROUP_NAME;
+	} else {
+		len = xdr_stream_decode_opaque_inline(xdr, (void **)&p,
+				XDR_MAX_NETOBJ);
+		if (len <= 0 || nfs_map_group_to_gid(server, p, len, gid) != 0)
+			goto out;
+		dprintk("%s: gid=%d\n", __func__, (int)from_kgid(&init_user_ns, *gid));
+		return NFS_ATTR_FATTR_GROUP;
+	}
+out:
+	if (len == -EBADMSG)
+		return -EIO;
+	return 0;
+}
+
+static int decode_attr_rdev(struct xdr_stream *xdr, uint32_t *bitmap, dev_t *rdev)
+{
+	uint32_t major = 0, minor = 0;
+	__be32 *p;
+	int ret = 0;
+
+	*rdev = MKDEV(0,0);
+	if (unlikely(bitmap[1] & (FATTR4_WORD1_RAWDEV - 1U)))
+		return -EIO;
+	if (likely(bitmap[1] & FATTR4_WORD1_RAWDEV)) {
+		dev_t tmp;
+
+		p = xdr_inline_decode(xdr, 8);
+		if (unlikely(!p))
+			return -EIO;
+		major = be32_to_cpup(p++);
+		minor = be32_to_cpup(p);
+		tmp = MKDEV(major, minor);
+		if (MAJOR(tmp) == major && MINOR(tmp) == minor)
+			*rdev = tmp;
+		bitmap[1] &= ~ FATTR4_WORD1_RAWDEV;
+		ret = NFS_ATTR_FATTR_RDEV;
+	}
+	dprintk("%s: rdev=(0x%x:0x%x)\n", __func__, major, minor);
+	return ret;
+}
+
+static int decode_attr_space_avail(struct xdr_stream *xdr, uint32_t *bitmap, uint64_t *res)
+{
+	__be32 *p;
+	int status = 0;
+
+	*res = 0;
+	if (unlikely(bitmap[1] & (FATTR4_WORD1_SPACE_AVAIL - 1U)))
+		return -EIO;
+	if (likely(bitmap[1] & FATTR4_WORD1_SPACE_AVAIL)) {
+		p = xdr_inline_decode(xdr, 8);
+		if (unlikely(!p))
+			return -EIO;
+		xdr_decode_hyper(p, res);
+		bitmap[1] &= ~FATTR4_WORD1_SPACE_AVAIL;
+	}
+	dprintk("%s: space avail=%Lu\n", __func__, (unsigned long long)*res);
+	return status;
+}
+
+static int decode_attr_space_free(struct xdr_stream *xdr, uint32_t *bitmap, uint64_t *res)
+{
+	__be32 *p;
+	int status = 0;
+
+	*res = 0;
+	if (unlikely(bitmap[1] & (FATTR4_WORD1_SPACE_FREE - 1U)))
+		return -EIO;
+	if (likely(bitmap[1] & FATTR4_WORD1_SPACE_FREE)) {
+		p = xdr_inline_decode(xdr, 8);
+		if (unlikely(!p))
+			return -EIO;
+		xdr_decode_hyper(p, res);
+		bitmap[1] &= ~FATTR4_WORD1_SPACE_FREE;
+	}
+	dprintk("%s: space free=%Lu\n", __func__, (unsigned long long)*res);
+	return status;
+}
+
+static int decode_attr_space_total(struct xdr_stream *xdr, uint32_t *bitmap, uint64_t *res)
+{
+	__be32 *p;
+	int status = 0;
+
+	*res = 0;
+	if (unlikely(bitmap[1] & (FATTR4_WORD1_SPACE_TOTAL - 1U)))
+		return -EIO;
+	if (likely(bitmap[1] & FATTR4_WORD1_SPACE_TOTAL)) {
+		p = xdr_inline_decode(xdr, 8);
+		if (unlikely(!p))
+			return -EIO;
+		xdr_decode_hyper(p, res);
+		bitmap[1] &= ~FATTR4_WORD1_SPACE_TOTAL;
+	}
+	dprintk("%s: space total=%Lu\n", __func__, (unsigned long long)*res);
+	return status;
+}
+
+static int decode_attr_space_used(struct xdr_stream *xdr, uint32_t *bitmap, uint64_t *used)
+{
+	__be32 *p;
+	int ret = 0;
+
+	*used = 0;
+	if (unlikely(bitmap[1] & (FATTR4_WORD1_SPACE_USED - 1U)))
+		return -EIO;
+	if (likely(bitmap[1] & FATTR4_WORD1_SPACE_USED)) {
+		p = xdr_inline_decode(xdr, 8);
+		if (unlikely(!p))
+			return -EIO;
+		xdr_decode_hyper(p, used);
+		bitmap[1] &= ~FATTR4_WORD1_SPACE_USED;
+		ret = NFS_ATTR_FATTR_SPACE_USED;
+	}
+	dprintk("%s: space used=%Lu\n", __func__,
+			(unsigned long long)*used);
+	return ret;
+}
+
+static __be32 *
+xdr_decode_nfstime4(__be32 *p, struct timespec64 *t)
+{
+	__u64 sec;
+
+	p = xdr_decode_hyper(p, &sec);
+	t-> tv_sec = sec;
+	t->tv_nsec = be32_to_cpup(p++);
+	return p;
+}
+
+static int decode_attr_time(struct xdr_stream *xdr, struct timespec64 *time)
+{
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, nfstime4_maxsz << 2);
+	if (unlikely(!p))
+		return -EIO;
+	xdr_decode_nfstime4(p, time);
+	return 0;
+}
+
+static int decode_attr_time_access(struct xdr_stream *xdr, uint32_t *bitmap, struct timespec64 *time)
+{
+	int status = 0;
+
+	time->tv_sec = 0;
+	time->tv_nsec = 0;
+	if (unlikely(bitmap[1] & (FATTR4_WORD1_TIME_ACCESS - 1U)))
+		return -EIO;
+	if (likely(bitmap[1] & FATTR4_WORD1_TIME_ACCESS)) {
+		status = decode_attr_time(xdr, time);
+		if (status == 0)
+			status = NFS_ATTR_FATTR_ATIME;
+		bitmap[1] &= ~FATTR4_WORD1_TIME_ACCESS;
+	}
+	dprintk("%s: atime=%lld\n", __func__, time->tv_sec);
+	return status;
+}
+
+static int decode_attr_time_metadata(struct xdr_stream *xdr, uint32_t *bitmap, struct timespec64 *time)
+{
+	int status = 0;
+
+	time->tv_sec = 0;
+	time->tv_nsec = 0;
+	if (unlikely(bitmap[1] & (FATTR4_WORD1_TIME_METADATA - 1U)))
+		return -EIO;
+	if (likely(bitmap[1] & FATTR4_WORD1_TIME_METADATA)) {
+		status = decode_attr_time(xdr, time);
+		if (status == 0)
+			status = NFS_ATTR_FATTR_CTIME;
+		bitmap[1] &= ~FATTR4_WORD1_TIME_METADATA;
+	}
+	dprintk("%s: ctime=%lld\n", __func__, time->tv_sec);
+	return status;
+}
+
+static int decode_attr_time_delta(struct xdr_stream *xdr, uint32_t *bitmap,
+				  struct timespec64 *time)
+{
+	int status = 0;
+
+	time->tv_sec = 0;
+	time->tv_nsec = 0;
+	if (unlikely(bitmap[1] & (FATTR4_WORD1_TIME_DELTA - 1U)))
+		return -EIO;
+	if (likely(bitmap[1] & FATTR4_WORD1_TIME_DELTA)) {
+		status = decode_attr_time(xdr, time);
+		bitmap[1] &= ~FATTR4_WORD1_TIME_DELTA;
+	}
+	dprintk("%s: time_delta=%lld %ld\n", __func__, time->tv_sec,
+		time->tv_nsec);
+	return status;
+}
+
+static int decode_attr_security_label(struct xdr_stream *xdr, uint32_t *bitmap,
+					struct nfs4_label *label)
+{
+	uint32_t pi = 0;
+	uint32_t lfs = 0;
+	__u32 len;
+	__be32 *p;
+	int status = 0;
+
+	if (unlikely(bitmap[2] & (FATTR4_WORD2_SECURITY_LABEL - 1U)))
+		return -EIO;
+	if (likely(bitmap[2] & FATTR4_WORD2_SECURITY_LABEL)) {
+		p = xdr_inline_decode(xdr, 4);
+		if (unlikely(!p))
+			return -EIO;
+		lfs = be32_to_cpup(p++);
+		p = xdr_inline_decode(xdr, 4);
+		if (unlikely(!p))
+			return -EIO;
+		pi = be32_to_cpup(p++);
+		p = xdr_inline_decode(xdr, 4);
+		if (unlikely(!p))
+			return -EIO;
+		len = be32_to_cpup(p++);
+		p = xdr_inline_decode(xdr, len);
+		if (unlikely(!p))
+			return -EIO;
+		bitmap[2] &= ~FATTR4_WORD2_SECURITY_LABEL;
+		if (len < NFS4_MAXLABELLEN) {
+			if (label && label->len) {
+				if (label->len < len)
+					return -ERANGE;
+				memcpy(label->label, p, len);
+				label->len = len;
+				label->pi = pi;
+				label->lfs = lfs;
+				status = NFS_ATTR_FATTR_V4_SECURITY_LABEL;
+			}
+		} else
+			printk(KERN_WARNING "%s: label too long (%u)!\n",
+					__func__, len);
+		if (label && label->label)
+			dprintk("%s: label=%.*s, len=%d, PI=%d, LFS=%d\n",
+				__func__, label->len, (char *)label->label,
+				label->len, label->pi, label->lfs);
+	}
+	return status;
+}
+
+static int decode_attr_time_modify(struct xdr_stream *xdr, uint32_t *bitmap, struct timespec64 *time)
+{
+	int status = 0;
+
+	time->tv_sec = 0;
+	time->tv_nsec = 0;
+	if (unlikely(bitmap[1] & (FATTR4_WORD1_TIME_MODIFY - 1U)))
+		return -EIO;
+	if (likely(bitmap[1] & FATTR4_WORD1_TIME_MODIFY)) {
+		status = decode_attr_time(xdr, time);
+		if (status == 0)
+			status = NFS_ATTR_FATTR_MTIME;
+		bitmap[1] &= ~FATTR4_WORD1_TIME_MODIFY;
+	}
+	dprintk("%s: mtime=%lld\n", __func__, time->tv_sec);
+	return status;
+}
+
+static int decode_attr_xattrsupport(struct xdr_stream *xdr, uint32_t *bitmap,
+				    uint32_t *res)
+{
+	__be32 *p;
+
+	*res = 0;
+	if (unlikely(bitmap[2] & (FATTR4_WORD2_XATTR_SUPPORT - 1U)))
+		return -EIO;
+	if (likely(bitmap[2] & FATTR4_WORD2_XATTR_SUPPORT)) {
+		p = xdr_inline_decode(xdr, 4);
+		if (unlikely(!p))
+			return -EIO;
+		*res = be32_to_cpup(p);
+		bitmap[2] &= ~FATTR4_WORD2_XATTR_SUPPORT;
+	}
+	dprintk("%s: XATTR support=%s\n", __func__,
+		*res == 0 ? "false" : "true");
+	return 0;
+}
+
+static int verify_attr_len(struct xdr_stream *xdr, unsigned int savep, uint32_t attrlen)
+{
+	unsigned int attrwords = XDR_QUADLEN(attrlen);
+	unsigned int nwords = (xdr_stream_pos(xdr) - savep) >> 2;
+
+	if (unlikely(attrwords != nwords)) {
+		dprintk("%s: server returned incorrect attribute length: "
+			"%u %c %u\n",
+				__func__,
+				attrwords << 2,
+				(attrwords < nwords) ? '<' : '>',
+				nwords << 2);
+		return -EIO;
+	}
+	return 0;
+}
+
+static int decode_change_info(struct xdr_stream *xdr, struct nfs4_change_info *cinfo)
+{
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, 20);
+	if (unlikely(!p))
+		return -EIO;
+	cinfo->atomic = be32_to_cpup(p++);
+	p = xdr_decode_hyper(p, &cinfo->before);
+	xdr_decode_hyper(p, &cinfo->after);
+	return 0;
+}
+
+static int decode_access(struct xdr_stream *xdr, u32 *supported, u32 *access)
+{
+	__be32 *p;
+	uint32_t supp, acc;
+	int status;
+
+	status = decode_op_hdr(xdr, OP_ACCESS);
+	if (status)
+		return status;
+	p = xdr_inline_decode(xdr, 8);
+	if (unlikely(!p))
+		return -EIO;
+	supp = be32_to_cpup(p++);
+	acc = be32_to_cpup(p);
+	*supported = supp;
+	*access = acc;
+	return 0;
+}
+
+static int decode_opaque_fixed(struct xdr_stream *xdr, void *buf, size_t len)
+{
+	ssize_t ret = xdr_stream_decode_opaque_fixed(xdr, buf, len);
+	if (unlikely(ret < 0))
+		return -EIO;
+	return 0;
+}
+
+static int decode_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
+{
+	return decode_opaque_fixed(xdr, stateid, NFS4_STATEID_SIZE);
+}
+
+static int decode_open_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
+{
+	stateid->type = NFS4_OPEN_STATEID_TYPE;
+	return decode_stateid(xdr, stateid);
+}
+
+static int decode_lock_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
+{
+	stateid->type = NFS4_LOCK_STATEID_TYPE;
+	return decode_stateid(xdr, stateid);
+}
+
+static int decode_delegation_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
+{
+	stateid->type = NFS4_DELEGATION_STATEID_TYPE;
+	return decode_stateid(xdr, stateid);
+}
+
+static int decode_invalid_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
+{
+	nfs4_stateid dummy;
+
+	nfs4_stateid_copy(stateid, &invalid_stateid);
+	return decode_stateid(xdr, &dummy);
+}
+
+static int decode_close(struct xdr_stream *xdr, struct nfs_closeres *res)
+{
+	int status;
+
+	status = decode_op_hdr(xdr, OP_CLOSE);
+	if (status != -EIO)
+		nfs_increment_open_seqid(status, res->seqid);
+	if (!status)
+		status = decode_invalid_stateid(xdr, &res->stateid);
+	return status;
+}
+
+static int decode_verifier(struct xdr_stream *xdr, void *verifier)
+{
+	return decode_opaque_fixed(xdr, verifier, NFS4_VERIFIER_SIZE);
+}
+
+static int decode_write_verifier(struct xdr_stream *xdr, struct nfs_write_verifier *verifier)
+{
+	return decode_opaque_fixed(xdr, verifier->data, NFS4_VERIFIER_SIZE);
+}
+
+static int decode_commit(struct xdr_stream *xdr, struct nfs_commitres *res)
+{
+	struct nfs_writeverf *verf = res->verf;
+	int status;
+
+	status = decode_op_hdr(xdr, OP_COMMIT);
+	if (!status)
+		status = decode_write_verifier(xdr, &verf->verifier);
+	if (!status)
+		verf->committed = NFS_FILE_SYNC;
+	return status;
+}
+
+static int decode_create(struct xdr_stream *xdr, struct nfs4_change_info *cinfo)
+{
+	__be32 *p;
+	uint32_t bmlen;
+	int status;
+
+	status = decode_op_hdr(xdr, OP_CREATE);
+	if (status)
+		return status;
+	if ((status = decode_change_info(xdr, cinfo)))
+		return status;
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(!p))
+		return -EIO;
+	bmlen = be32_to_cpup(p);
+	p = xdr_inline_decode(xdr, bmlen << 2);
+	if (likely(p))
+		return 0;
+	return -EIO;
+}
+
+static int decode_server_caps(struct xdr_stream *xdr, struct nfs4_server_caps_res *res)
+{
+	unsigned int savep;
+	uint32_t attrlen, bitmap[3] = {0};
+	int status;
+
+	if ((status = decode_op_hdr(xdr, OP_GETATTR)) != 0)
+		goto xdr_error;
+	if ((status = decode_attr_bitmap(xdr, bitmap)) != 0)
+		goto xdr_error;
+	if ((status = decode_attr_length(xdr, &attrlen, &savep)) != 0)
+		goto xdr_error;
+	if ((status = decode_attr_supported(xdr, bitmap, res->attr_bitmask)) != 0)
+		goto xdr_error;
+	if ((status = decode_attr_fh_expire_type(xdr, bitmap,
+						 &res->fh_expire_type)) != 0)
+		goto xdr_error;
+	if ((status = decode_attr_link_support(xdr, bitmap, &res->has_links)) != 0)
+		goto xdr_error;
+	if ((status = decode_attr_symlink_support(xdr, bitmap, &res->has_symlinks)) != 0)
+		goto xdr_error;
+	if ((status = decode_attr_aclsupport(xdr, bitmap, &res->acl_bitmask)) != 0)
+		goto xdr_error;
+	if ((status = decode_attr_exclcreat_supported(xdr, bitmap,
+				res->exclcreat_bitmask)) != 0)
+		goto xdr_error;
+	status = verify_attr_len(xdr, savep, attrlen);
+xdr_error:
+	dprintk("%s: xdr returned %d!\n", __func__, -status);
+	return status;
+}
+
+static int decode_statfs(struct xdr_stream *xdr, struct nfs_fsstat *fsstat)
+{
+	unsigned int savep;
+	uint32_t attrlen, bitmap[3] = {0};
+	int status;
+
+	if ((status = decode_op_hdr(xdr, OP_GETATTR)) != 0)
+		goto xdr_error;
+	if ((status = decode_attr_bitmap(xdr, bitmap)) != 0)
+		goto xdr_error;
+	if ((status = decode_attr_length(xdr, &attrlen, &savep)) != 0)
+		goto xdr_error;
+
+	if ((status = decode_attr_files_avail(xdr, bitmap, &fsstat->afiles)) != 0)
+		goto xdr_error;
+	if ((status = decode_attr_files_free(xdr, bitmap, &fsstat->ffiles)) != 0)
+		goto xdr_error;
+	if ((status = decode_attr_files_total(xdr, bitmap, &fsstat->tfiles)) != 0)
+		goto xdr_error;
+
+	status = -EIO;
+	if (unlikely(bitmap[0]))
+		goto xdr_error;
+
+	if ((status = decode_attr_space_avail(xdr, bitmap, &fsstat->abytes)) != 0)
+		goto xdr_error;
+	if ((status = decode_attr_space_free(xdr, bitmap, &fsstat->fbytes)) != 0)
+		goto xdr_error;
+	if ((status = decode_attr_space_total(xdr, bitmap, &fsstat->tbytes)) != 0)
+		goto xdr_error;
+
+	status = verify_attr_len(xdr, savep, attrlen);
+xdr_error:
+	dprintk("%s: xdr returned %d!\n", __func__, -status);
+	return status;
+}
+
+static int decode_pathconf(struct xdr_stream *xdr, struct nfs_pathconf *pathconf)
+{
+	unsigned int savep;
+	uint32_t attrlen, bitmap[3] = {0};
+	int status;
+
+	if ((status = decode_op_hdr(xdr, OP_GETATTR)) != 0)
+		goto xdr_error;
+	if ((status = decode_attr_bitmap(xdr, bitmap)) != 0)
+		goto xdr_error;
+	if ((status = decode_attr_length(xdr, &attrlen, &savep)) != 0)
+		goto xdr_error;
+
+	if ((status = decode_attr_maxlink(xdr, bitmap, &pathconf->max_link)) != 0)
+		goto xdr_error;
+	if ((status = decode_attr_maxname(xdr, bitmap, &pathconf->max_namelen)) != 0)
+		goto xdr_error;
+
+	status = verify_attr_len(xdr, savep, attrlen);
+xdr_error:
+	dprintk("%s: xdr returned %d!\n", __func__, -status);
+	return status;
+}
+
+static int decode_threshold_hint(struct xdr_stream *xdr,
+				  uint32_t *bitmap,
+				  uint64_t *res,
+				  uint32_t hint_bit)
+{
+	__be32 *p;
+
+	*res = 0;
+	if (likely(bitmap[0] & hint_bit)) {
+		p = xdr_inline_decode(xdr, 8);
+		if (unlikely(!p))
+			return -EIO;
+		xdr_decode_hyper(p, res);
+	}
+	return 0;
+}
+
+static int decode_first_threshold_item4(struct xdr_stream *xdr,
+					struct nfs4_threshold *res)
+{
+	__be32 *p;
+	unsigned int savep;
+	uint32_t bitmap[3] = {0,}, attrlen;
+	int status;
+
+	/* layout type */
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(!p))
+		return -EIO;
+	res->l_type = be32_to_cpup(p);
+
+	/* thi_hintset bitmap */
+	status = decode_attr_bitmap(xdr, bitmap);
+	if (status < 0)
+		goto xdr_error;
+
+	/* thi_hintlist length */
+	status = decode_attr_length(xdr, &attrlen, &savep);
+	if (status < 0)
+		goto xdr_error;
+	/* thi_hintlist */
+	status = decode_threshold_hint(xdr, bitmap, &res->rd_sz, THRESHOLD_RD);
+	if (status < 0)
+		goto xdr_error;
+	status = decode_threshold_hint(xdr, bitmap, &res->wr_sz, THRESHOLD_WR);
+	if (status < 0)
+		goto xdr_error;
+	status = decode_threshold_hint(xdr, bitmap, &res->rd_io_sz,
+				       THRESHOLD_RD_IO);
+	if (status < 0)
+		goto xdr_error;
+	status = decode_threshold_hint(xdr, bitmap, &res->wr_io_sz,
+				       THRESHOLD_WR_IO);
+	if (status < 0)
+		goto xdr_error;
+
+	status = verify_attr_len(xdr, savep, attrlen);
+	res->bm = bitmap[0];
+
+	dprintk("%s bm=0x%x rd_sz=%llu wr_sz=%llu rd_io=%llu wr_io=%llu\n",
+		 __func__, res->bm, res->rd_sz, res->wr_sz, res->rd_io_sz,
+		res->wr_io_sz);
+xdr_error:
+	dprintk("%s ret=%d!\n", __func__, status);
+	return status;
+}
+
+/*
+ * Thresholds on pNFS direct I/O vrs MDS I/O
+ */
+static int decode_attr_mdsthreshold(struct xdr_stream *xdr,
+				    uint32_t *bitmap,
+				    struct nfs4_threshold *res)
+{
+	__be32 *p;
+	int status = 0;
+	uint32_t num;
+
+	if (unlikely(bitmap[2] & (FATTR4_WORD2_MDSTHRESHOLD - 1U)))
+		return -EIO;
+	if (bitmap[2] & FATTR4_WORD2_MDSTHRESHOLD) {
+		/* Did the server return an unrequested attribute? */
+		if (unlikely(res == NULL))
+			return -EREMOTEIO;
+		p = xdr_inline_decode(xdr, 4);
+		if (unlikely(!p))
+			return -EIO;
+		num = be32_to_cpup(p);
+		if (num == 0)
+			return 0;
+		if (num > 1)
+			printk(KERN_INFO "%s: Warning: Multiple pNFS layout "
+				"drivers per filesystem not supported\n",
+				__func__);
+
+		status = decode_first_threshold_item4(xdr, res);
+		bitmap[2] &= ~FATTR4_WORD2_MDSTHRESHOLD;
+	}
+	return status;
+}
+
+static int decode_getfattr_attrs(struct xdr_stream *xdr, uint32_t *bitmap,
+		struct nfs_fattr *fattr, struct nfs_fh *fh,
+		struct nfs4_fs_locations *fs_loc, struct nfs4_label *label,
+		const struct nfs_server *server)
+{
+	int status;
+	umode_t fmode = 0;
+	uint32_t type;
+	int32_t err;
+
+	status = decode_attr_type(xdr, bitmap, &type);
+	if (status < 0)
+		goto xdr_error;
+	fattr->mode = 0;
+	if (status != 0) {
+		fattr->mode |= nfs_type2fmt[type];
+		fattr->valid |= status;
+	}
+
+	status = decode_attr_change(xdr, bitmap, &fattr->change_attr);
+	if (status < 0)
+		goto xdr_error;
+	fattr->valid |= status;
+
+	status = decode_attr_size(xdr, bitmap, &fattr->size);
+	if (status < 0)
+		goto xdr_error;
+	fattr->valid |= status;
+
+	status = decode_attr_fsid(xdr, bitmap, &fattr->fsid);
+	if (status < 0)
+		goto xdr_error;
+	fattr->valid |= status;
+
+	err = 0;
+	status = decode_attr_error(xdr, bitmap, &err);
+	if (status < 0)
+		goto xdr_error;
+
+	status = decode_attr_filehandle(xdr, bitmap, fh);
+	if (status < 0)
+		goto xdr_error;
+
+	status = decode_attr_fileid(xdr, bitmap, &fattr->fileid);
+	if (status < 0)
+		goto xdr_error;
+	fattr->valid |= status;
+
+	status = decode_attr_fs_locations(xdr, bitmap, fs_loc);
+	if (status < 0)
+		goto xdr_error;
+	fattr->valid |= status;
+
+	status = -EIO;
+	if (unlikely(bitmap[0]))
+		goto xdr_error;
+
+	status = decode_attr_mode(xdr, bitmap, &fmode);
+	if (status < 0)
+		goto xdr_error;
+	if (status != 0) {
+		fattr->mode |= fmode;
+		fattr->valid |= status;
+	}
+
+	status = decode_attr_nlink(xdr, bitmap, &fattr->nlink);
+	if (status < 0)
+		goto xdr_error;
+	fattr->valid |= status;
+
+	status = decode_attr_owner(xdr, bitmap, server, &fattr->uid, fattr->owner_name);
+	if (status < 0)
+		goto xdr_error;
+	fattr->valid |= status;
+
+	status = decode_attr_group(xdr, bitmap, server, &fattr->gid, fattr->group_name);
+	if (status < 0)
+		goto xdr_error;
+	fattr->valid |= status;
+
+	status = decode_attr_rdev(xdr, bitmap, &fattr->rdev);
+	if (status < 0)
+		goto xdr_error;
+	fattr->valid |= status;
+
+	status = decode_attr_space_used(xdr, bitmap, &fattr->du.nfs3.used);
+	if (status < 0)
+		goto xdr_error;
+	fattr->valid |= status;
+
+	status = decode_attr_time_access(xdr, bitmap, &fattr->atime);
+	if (status < 0)
+		goto xdr_error;
+	fattr->valid |= status;
+
+	status = decode_attr_time_metadata(xdr, bitmap, &fattr->ctime);
+	if (status < 0)
+		goto xdr_error;
+	fattr->valid |= status;
+
+	status = decode_attr_time_modify(xdr, bitmap, &fattr->mtime);
+	if (status < 0)
+		goto xdr_error;
+	fattr->valid |= status;
+
+	status = decode_attr_mounted_on_fileid(xdr, bitmap, &fattr->mounted_on_fileid);
+	if (status < 0)
+		goto xdr_error;
+	fattr->valid |= status;
+
+	status = -EIO;
+	if (unlikely(bitmap[1]))
+		goto xdr_error;
+
+	status = decode_attr_mdsthreshold(xdr, bitmap, fattr->mdsthreshold);
+	if (status < 0)
+		goto xdr_error;
+
+	if (label) {
+		status = decode_attr_security_label(xdr, bitmap, label);
+		if (status < 0)
+			goto xdr_error;
+		fattr->valid |= status;
+	}
+
+xdr_error:
+	dprintk("%s: xdr returned %d\n", __func__, -status);
+	return status;
+}
+
+static int decode_getfattr_generic(struct xdr_stream *xdr, struct nfs_fattr *fattr,
+		struct nfs_fh *fh, struct nfs4_fs_locations *fs_loc,
+		struct nfs4_label *label, const struct nfs_server *server)
+{
+	unsigned int savep;
+	uint32_t attrlen,
+		 bitmap[3] = {0};
+	int status;
+
+	status = decode_op_hdr(xdr, OP_GETATTR);
+	if (status < 0)
+		goto xdr_error;
+
+	status = decode_attr_bitmap(xdr, bitmap);
+	if (status < 0)
+		goto xdr_error;
+
+	status = decode_attr_length(xdr, &attrlen, &savep);
+	if (status < 0)
+		goto xdr_error;
+
+	status = decode_getfattr_attrs(xdr, bitmap, fattr, fh, fs_loc,
+					label, server);
+	if (status < 0)
+		goto xdr_error;
+
+	status = verify_attr_len(xdr, savep, attrlen);
+xdr_error:
+	dprintk("%s: xdr returned %d\n", __func__, -status);
+	return status;
+}
+
+static int decode_getfattr_label(struct xdr_stream *xdr, struct nfs_fattr *fattr,
+		struct nfs4_label *label, const struct nfs_server *server)
+{
+	return decode_getfattr_generic(xdr, fattr, NULL, NULL, label, server);
+}
+
+static int decode_getfattr(struct xdr_stream *xdr, struct nfs_fattr *fattr,
+		const struct nfs_server *server)
+{
+	return decode_getfattr_generic(xdr, fattr, NULL, NULL, NULL, server);
+}
+
+/*
+ * Decode potentially multiple layout types.
+ */
+static int decode_pnfs_layout_types(struct xdr_stream *xdr,
+				    struct nfs_fsinfo *fsinfo)
+{
+	__be32 *p;
+	uint32_t i;
+
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(!p))
+		return -EIO;
+	fsinfo->nlayouttypes = be32_to_cpup(p);
+
+	/* pNFS is not supported by the underlying file system */
+	if (fsinfo->nlayouttypes == 0)
+		return 0;
+
+	/* Decode and set first layout type, move xdr->p past unused types */
+	p = xdr_inline_decode(xdr, fsinfo->nlayouttypes * 4);
+	if (unlikely(!p))
+		return -EIO;
+
+	/* If we get too many, then just cap it at the max */
+	if (fsinfo->nlayouttypes > NFS_MAX_LAYOUT_TYPES) {
+		printk(KERN_INFO "NFS: %s: Warning: Too many (%u) pNFS layout types\n",
+			__func__, fsinfo->nlayouttypes);
+		fsinfo->nlayouttypes = NFS_MAX_LAYOUT_TYPES;
+	}
+
+	for(i = 0; i < fsinfo->nlayouttypes; ++i)
+		fsinfo->layouttype[i] = be32_to_cpup(p++);
+	return 0;
+}
+
+/*
+ * The type of file system exported.
+ * Note we must ensure that layouttype is set in any non-error case.
+ */
+static int decode_attr_pnfstype(struct xdr_stream *xdr, uint32_t *bitmap,
+				struct nfs_fsinfo *fsinfo)
+{
+	int status = 0;
+
+	dprintk("%s: bitmap is %x\n", __func__, bitmap[1]);
+	if (unlikely(bitmap[1] & (FATTR4_WORD1_FS_LAYOUT_TYPES - 1U)))
+		return -EIO;
+	if (bitmap[1] & FATTR4_WORD1_FS_LAYOUT_TYPES) {
+		status = decode_pnfs_layout_types(xdr, fsinfo);
+		bitmap[1] &= ~FATTR4_WORD1_FS_LAYOUT_TYPES;
+	}
+	return status;
+}
+
+/*
+ * The prefered block size for layout directed io
+ */
+static int decode_attr_layout_blksize(struct xdr_stream *xdr, uint32_t *bitmap,
+				      uint32_t *res)
+{
+	__be32 *p;
+
+	dprintk("%s: bitmap is %x\n", __func__, bitmap[2]);
+	*res = 0;
+	if (bitmap[2] & FATTR4_WORD2_LAYOUT_BLKSIZE) {
+		p = xdr_inline_decode(xdr, 4);
+		if (unlikely(!p))
+			return -EIO;
+		*res = be32_to_cpup(p);
+		bitmap[2] &= ~FATTR4_WORD2_LAYOUT_BLKSIZE;
+	}
+	return 0;
+}
+
+/*
+ * The granularity of a CLONE operation.
+ */
+static int decode_attr_clone_blksize(struct xdr_stream *xdr, uint32_t *bitmap,
+				     uint32_t *res)
+{
+	__be32 *p;
+
+	dprintk("%s: bitmap is %x\n", __func__, bitmap[2]);
+	*res = 0;
+	if (bitmap[2] & FATTR4_WORD2_CLONE_BLKSIZE) {
+		p = xdr_inline_decode(xdr, 4);
+		if (unlikely(!p))
+			return -EIO;
+		*res = be32_to_cpup(p);
+		bitmap[2] &= ~FATTR4_WORD2_CLONE_BLKSIZE;
+	}
+	return 0;
+}
+
+static int decode_fsinfo(struct xdr_stream *xdr, struct nfs_fsinfo *fsinfo)
+{
+	unsigned int savep;
+	uint32_t attrlen, bitmap[3];
+	int status;
+
+	if ((status = decode_op_hdr(xdr, OP_GETATTR)) != 0)
+		goto xdr_error;
+	if ((status = decode_attr_bitmap(xdr, bitmap)) != 0)
+		goto xdr_error;
+	if ((status = decode_attr_length(xdr, &attrlen, &savep)) != 0)
+		goto xdr_error;
+
+	fsinfo->rtmult = fsinfo->wtmult = 512;	/* ??? */
+
+	if ((status = decode_attr_lease_time(xdr, bitmap, &fsinfo->lease_time)) != 0)
+		goto xdr_error;
+	if ((status = decode_attr_maxfilesize(xdr, bitmap, &fsinfo->maxfilesize)) != 0)
+		goto xdr_error;
+	if ((status = decode_attr_maxread(xdr, bitmap, &fsinfo->rtmax)) != 0)
+		goto xdr_error;
+	fsinfo->rtpref = fsinfo->dtpref = fsinfo->rtmax;
+	if ((status = decode_attr_maxwrite(xdr, bitmap, &fsinfo->wtmax)) != 0)
+		goto xdr_error;
+	fsinfo->wtpref = fsinfo->wtmax;
+
+	status = -EIO;
+	if (unlikely(bitmap[0]))
+		goto xdr_error;
+
+	status = decode_attr_time_delta(xdr, bitmap, &fsinfo->time_delta);
+	if (status != 0)
+		goto xdr_error;
+	status = decode_attr_pnfstype(xdr, bitmap, fsinfo);
+	if (status != 0)
+		goto xdr_error;
+
+	status = -EIO;
+	if (unlikely(bitmap[1]))
+		goto xdr_error;
+
+	status = decode_attr_layout_blksize(xdr, bitmap, &fsinfo->blksize);
+	if (status)
+		goto xdr_error;
+	status = decode_attr_clone_blksize(xdr, bitmap, &fsinfo->clone_blksize);
+	if (status)
+		goto xdr_error;
+
+	status = decode_attr_xattrsupport(xdr, bitmap,
+					  &fsinfo->xattr_support);
+	if (status)
+		goto xdr_error;
+
+	status = verify_attr_len(xdr, savep, attrlen);
+xdr_error:
+	dprintk("%s: xdr returned %d!\n", __func__, -status);
+	return status;
+}
+
+static int decode_getfh(struct xdr_stream *xdr, struct nfs_fh *fh)
+{
+	__be32 *p;
+	uint32_t len;
+	int status;
+
+	/* Zero handle first to allow comparisons */
+	memset(fh, 0, sizeof(*fh));
+
+	status = decode_op_hdr(xdr, OP_GETFH);
+	if (status)
+		return status;
+
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(!p))
+		return -EIO;
+	len = be32_to_cpup(p);
+	if (len > NFS4_FHSIZE)
+		return -EIO;
+	fh->size = len;
+	p = xdr_inline_decode(xdr, len);
+	if (unlikely(!p))
+		return -EIO;
+	memcpy(fh->data, p, len);
+	return 0;
+}
+
+static int decode_link(struct xdr_stream *xdr, struct nfs4_change_info *cinfo)
+{
+	int status;
+
+	status = decode_op_hdr(xdr, OP_LINK);
+	if (status)
+		return status;
+	return decode_change_info(xdr, cinfo);
+}
+
+/*
+ * We create the owner, so we know a proper owner.id length is 4.
+ */
+static int decode_lock_denied (struct xdr_stream *xdr, struct file_lock *fl)
+{
+	uint64_t offset, length, clientid;
+	__be32 *p;
+	uint32_t namelen, type;
+
+	p = xdr_inline_decode(xdr, 32); /* read 32 bytes */
+	if (unlikely(!p))
+		return -EIO;
+	p = xdr_decode_hyper(p, &offset); /* read 2 8-byte long words */
+	p = xdr_decode_hyper(p, &length);
+	type = be32_to_cpup(p++); /* 4 byte read */
+	if (fl != NULL) { /* manipulate file lock */
+		fl->fl_start = (loff_t)offset;
+		fl->fl_end = fl->fl_start + (loff_t)length - 1;
+		if (length == ~(uint64_t)0)
+			fl->fl_end = OFFSET_MAX;
+		fl->fl_type = F_WRLCK;
+		if (type & 1)
+			fl->fl_type = F_RDLCK;
+		fl->fl_pid = 0;
+	}
+	p = xdr_decode_hyper(p, &clientid); /* read 8 bytes */
+	namelen = be32_to_cpup(p); /* read 4 bytes */  /* have read all 32 bytes now */
+	p = xdr_inline_decode(xdr, namelen); /* variable size field */
+	if (likely(!p))
+		return -EIO;
+	return -NFS4ERR_DENIED;
+}
+
+static int decode_lock(struct xdr_stream *xdr, struct nfs_lock_res *res)
+{
+	int status;
+
+	status = decode_op_hdr(xdr, OP_LOCK);
+	if (status == -EIO)
+		goto out;
+	if (status == 0) {
+		status = decode_lock_stateid(xdr, &res->stateid);
+		if (unlikely(status))
+			goto out;
+	} else if (status == -NFS4ERR_DENIED)
+		status = decode_lock_denied(xdr, NULL);
+	if (res->open_seqid != NULL)
+		nfs_increment_open_seqid(status, res->open_seqid);
+	nfs_increment_lock_seqid(status, res->lock_seqid);
+out:
+	return status;
+}
+
+static int decode_lockt(struct xdr_stream *xdr, struct nfs_lockt_res *res)
+{
+	int status;
+	status = decode_op_hdr(xdr, OP_LOCKT);
+	if (status == -NFS4ERR_DENIED)
+		return decode_lock_denied(xdr, res->denied);
+	return status;
+}
+
+static int decode_locku(struct xdr_stream *xdr, struct nfs_locku_res *res)
+{
+	int status;
+
+	status = decode_op_hdr(xdr, OP_LOCKU);
+	if (status != -EIO)
+		nfs_increment_lock_seqid(status, res->seqid);
+	if (status == 0)
+		status = decode_lock_stateid(xdr, &res->stateid);
+	return status;
+}
+
+static int decode_release_lockowner(struct xdr_stream *xdr)
+{
+	return decode_op_hdr(xdr, OP_RELEASE_LOCKOWNER);
+}
+
+static int decode_lookup(struct xdr_stream *xdr)
+{
+	return decode_op_hdr(xdr, OP_LOOKUP);
+}
+
+static int decode_lookupp(struct xdr_stream *xdr)
+{
+	return decode_op_hdr(xdr, OP_LOOKUPP);
+}
+
+/* This is too sick! */
+static int decode_space_limit(struct xdr_stream *xdr,
+		unsigned long *pagemod_limit)
+{
+	__be32 *p;
+	uint32_t limit_type, nblocks, blocksize;
+	u64 maxsize = 0;
+
+	p = xdr_inline_decode(xdr, 12);
+	if (unlikely(!p))
+		return -EIO;
+	limit_type = be32_to_cpup(p++);
+	switch (limit_type) {
+	case NFS4_LIMIT_SIZE:
+		xdr_decode_hyper(p, &maxsize);
+		break;
+	case NFS4_LIMIT_BLOCKS:
+		nblocks = be32_to_cpup(p++);
+		blocksize = be32_to_cpup(p);
+		maxsize = (uint64_t)nblocks * (uint64_t)blocksize;
+	}
+	maxsize >>= PAGE_SHIFT;
+	*pagemod_limit = min_t(u64, maxsize, ULONG_MAX);
+	return 0;
+}
+
+static int decode_rw_delegation(struct xdr_stream *xdr,
+		uint32_t delegation_type,
+		struct nfs_openres *res)
+{
+	__be32 *p;
+	int status;
+
+	status = decode_delegation_stateid(xdr, &res->delegation);
+	if (unlikely(status))
+		return status;
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(!p))
+		return -EIO;
+	res->do_recall = be32_to_cpup(p);
+
+	switch (delegation_type) {
+	case NFS4_OPEN_DELEGATE_READ:
+		res->delegation_type = FMODE_READ;
+		break;
+	case NFS4_OPEN_DELEGATE_WRITE:
+		res->delegation_type = FMODE_WRITE|FMODE_READ;
+		if (decode_space_limit(xdr, &res->pagemod_limit) < 0)
+				return -EIO;
+	}
+	return decode_ace(xdr, NULL);
+}
+
+static int decode_no_delegation(struct xdr_stream *xdr, struct nfs_openres *res)
+{
+	__be32 *p;
+	uint32_t why_no_delegation;
+
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(!p))
+		return -EIO;
+	why_no_delegation = be32_to_cpup(p);
+	switch (why_no_delegation) {
+		case WND4_CONTENTION:
+		case WND4_RESOURCE:
+			xdr_inline_decode(xdr, 4);
+			/* Ignore for now */
+	}
+	return 0;
+}
+
+static int decode_delegation(struct xdr_stream *xdr, struct nfs_openres *res)
+{
+	__be32 *p;
+	uint32_t delegation_type;
+
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(!p))
+		return -EIO;
+	delegation_type = be32_to_cpup(p);
+	res->delegation_type = 0;
+	switch (delegation_type) {
+	case NFS4_OPEN_DELEGATE_NONE:
+		return 0;
+	case NFS4_OPEN_DELEGATE_READ:
+	case NFS4_OPEN_DELEGATE_WRITE:
+		return decode_rw_delegation(xdr, delegation_type, res);
+	case NFS4_OPEN_DELEGATE_NONE_EXT:
+		return decode_no_delegation(xdr, res);
+	}
+	return -EIO;
+}
+
+static int decode_open(struct xdr_stream *xdr, struct nfs_openres *res)
+{
+	__be32 *p;
+	uint32_t savewords, bmlen, i;
+	int status;
+
+	if (!__decode_op_hdr(xdr, OP_OPEN, &status))
+		return status;
+	nfs_increment_open_seqid(status, res->seqid);
+	if (status)
+		return status;
+	status = decode_open_stateid(xdr, &res->stateid);
+	if (unlikely(status))
+		return status;
+
+	decode_change_info(xdr, &res->cinfo);
+
+	p = xdr_inline_decode(xdr, 8);
+	if (unlikely(!p))
+		return -EIO;
+	res->rflags = be32_to_cpup(p++);
+	bmlen = be32_to_cpup(p);
+	if (bmlen > 10)
+		goto xdr_error;
+
+	p = xdr_inline_decode(xdr, bmlen << 2);
+	if (unlikely(!p))
+		return -EIO;
+	savewords = min_t(uint32_t, bmlen, NFS4_BITMAP_SIZE);
+	for (i = 0; i < savewords; ++i)
+		res->attrset[i] = be32_to_cpup(p++);
+	for (; i < NFS4_BITMAP_SIZE; i++)
+		res->attrset[i] = 0;
+
+	return decode_delegation(xdr, res);
+xdr_error:
+	dprintk("%s: Bitmap too large! Length = %u\n", __func__, bmlen);
+	return -EIO;
+}
+
+static int decode_open_confirm(struct xdr_stream *xdr, struct nfs_open_confirmres *res)
+{
+	int status;
+
+	status = decode_op_hdr(xdr, OP_OPEN_CONFIRM);
+	if (status != -EIO)
+		nfs_increment_open_seqid(status, res->seqid);
+	if (!status)
+		status = decode_open_stateid(xdr, &res->stateid);
+	return status;
+}
+
+static int decode_open_downgrade(struct xdr_stream *xdr, struct nfs_closeres *res)
+{
+	int status;
+
+	status = decode_op_hdr(xdr, OP_OPEN_DOWNGRADE);
+	if (status != -EIO)
+		nfs_increment_open_seqid(status, res->seqid);
+	if (!status)
+		status = decode_open_stateid(xdr, &res->stateid);
+	return status;
+}
+
+static int decode_putfh(struct xdr_stream *xdr)
+{
+	return decode_op_hdr(xdr, OP_PUTFH);
+}
+
+static int decode_putrootfh(struct xdr_stream *xdr)
+{
+	return decode_op_hdr(xdr, OP_PUTROOTFH);
+}
+
+static int decode_read(struct xdr_stream *xdr, struct rpc_rqst *req,
+		       struct nfs_pgio_res *res)
+{
+	__be32 *p;
+	uint32_t count, eof, recvd;
+	int status;
+
+	status = decode_op_hdr(xdr, OP_READ);
+	if (status)
+		return status;
+	p = xdr_inline_decode(xdr, 8);
+	if (unlikely(!p))
+		return -EIO;
+	eof = be32_to_cpup(p++);
+	count = be32_to_cpup(p);
+	recvd = xdr_read_pages(xdr, count);
+	if (count > recvd) {
+		dprintk("NFS: server cheating in read reply: "
+				"count %u > recvd %u\n", count, recvd);
+		count = recvd;
+		eof = 0;
+	}
+	res->eof = eof;
+	res->count = count;
+	return 0;
+}
+
+static int decode_readdir(struct xdr_stream *xdr, struct rpc_rqst *req, struct nfs4_readdir_res *readdir)
+{
+	int		status;
+	__be32		verf[2];
+
+	status = decode_op_hdr(xdr, OP_READDIR);
+	if (!status)
+		status = decode_verifier(xdr, readdir->verifier.data);
+	if (unlikely(status))
+		return status;
+	memcpy(verf, readdir->verifier.data, sizeof(verf));
+	dprintk("%s: verifier = %08x:%08x\n",
+			__func__, verf[0], verf[1]);
+	return xdr_read_pages(xdr, xdr->buf->page_len);
+}
+
+static int decode_readlink(struct xdr_stream *xdr, struct rpc_rqst *req)
+{
+	struct xdr_buf *rcvbuf = &req->rq_rcv_buf;
+	u32 len, recvd;
+	__be32 *p;
+	int status;
+
+	status = decode_op_hdr(xdr, OP_READLINK);
+	if (status)
+		return status;
+
+	/* Convert length of symlink */
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(!p))
+		return -EIO;
+	len = be32_to_cpup(p);
+	if (len >= rcvbuf->page_len || len <= 0) {
+		dprintk("nfs: server returned giant symlink!\n");
+		return -ENAMETOOLONG;
+	}
+	recvd = xdr_read_pages(xdr, len);
+	if (recvd < len) {
+		dprintk("NFS: server cheating in readlink reply: "
+				"count %u > recvd %u\n", len, recvd);
+		return -EIO;
+	}
+	/*
+	 * The XDR encode routine has set things up so that
+	 * the link text will be copied directly into the
+	 * buffer.  We just have to do overflow-checking,
+	 * and null-terminate the text (the VFS expects
+	 * null-termination).
+	 */
+	xdr_terminate_string(rcvbuf, len);
+	return 0;
+}
+
+static int decode_remove(struct xdr_stream *xdr, struct nfs4_change_info *cinfo)
+{
+	int status;
+
+	status = decode_op_hdr(xdr, OP_REMOVE);
+	if (status)
+		goto out;
+	status = decode_change_info(xdr, cinfo);
+out:
+	return status;
+}
+
+static int decode_rename(struct xdr_stream *xdr, struct nfs4_change_info *old_cinfo,
+	      struct nfs4_change_info *new_cinfo)
+{
+	int status;
+
+	status = decode_op_hdr(xdr, OP_RENAME);
+	if (status)
+		goto out;
+	if ((status = decode_change_info(xdr, old_cinfo)))
+		goto out;
+	status = decode_change_info(xdr, new_cinfo);
+out:
+	return status;
+}
+
+static int decode_renew(struct xdr_stream *xdr)
+{
+	return decode_op_hdr(xdr, OP_RENEW);
+}
+
+static int
+decode_restorefh(struct xdr_stream *xdr)
+{
+	return decode_op_hdr(xdr, OP_RESTOREFH);
+}
+
+static int decode_getacl(struct xdr_stream *xdr, struct rpc_rqst *req,
+			 struct nfs_getaclres *res)
+{
+	unsigned int savep;
+	uint32_t attrlen,
+		 bitmap[3] = {0};
+	int status;
+
+	res->acl_len = 0;
+	if ((status = decode_op_hdr(xdr, OP_GETATTR)) != 0)
+		goto out;
+
+	xdr_enter_page(xdr, xdr->buf->page_len);
+
+	if ((status = decode_attr_bitmap(xdr, bitmap)) != 0)
+		goto out;
+	if ((status = decode_attr_length(xdr, &attrlen, &savep)) != 0)
+		goto out;
+
+	if (unlikely(bitmap[0] & (FATTR4_WORD0_ACL - 1U)))
+		return -EIO;
+	if (likely(bitmap[0] & FATTR4_WORD0_ACL)) {
+
+		/* The bitmap (xdr len + bitmaps) and the attr xdr len words
+		 * are stored with the acl data to handle the problem of
+		 * variable length bitmaps.*/
+		res->acl_data_offset = xdr_page_pos(xdr);
+		res->acl_len = attrlen;
+
+		/* Check for receive buffer overflow */
+		if (res->acl_len > (xdr->nwords << 2) ||
+		    res->acl_len + res->acl_data_offset > xdr->buf->page_len) {
+			res->acl_flags |= NFS4_ACL_TRUNC;
+			dprintk("NFS: acl reply: attrlen %u > page_len %u\n",
+					attrlen, xdr->nwords << 2);
+		}
+	} else
+		status = -EOPNOTSUPP;
+
+out:
+	return status;
+}
+
+static int
+decode_savefh(struct xdr_stream *xdr)
+{
+	return decode_op_hdr(xdr, OP_SAVEFH);
+}
+
+static int decode_setattr(struct xdr_stream *xdr)
+{
+	int status;
+
+	status = decode_op_hdr(xdr, OP_SETATTR);
+	if (status)
+		return status;
+	if (decode_bitmap4(xdr, NULL, 0) >= 0)
+		return 0;
+	return -EIO;
+}
+
+static int decode_setclientid(struct xdr_stream *xdr, struct nfs4_setclientid_res *res)
+{
+	__be32 *p;
+	uint32_t opnum;
+	int32_t nfserr;
+
+	p = xdr_inline_decode(xdr, 8);
+	if (unlikely(!p))
+		return -EIO;
+	opnum = be32_to_cpup(p++);
+	if (opnum != OP_SETCLIENTID) {
+		dprintk("nfs: decode_setclientid: Server returned operation"
+			" %d\n", opnum);
+		return -EIO;
+	}
+	nfserr = be32_to_cpup(p);
+	if (nfserr == NFS_OK) {
+		p = xdr_inline_decode(xdr, 8 + NFS4_VERIFIER_SIZE);
+		if (unlikely(!p))
+			return -EIO;
+		p = xdr_decode_hyper(p, &res->clientid);
+		memcpy(res->confirm.data, p, NFS4_VERIFIER_SIZE);
+	} else if (nfserr == NFSERR_CLID_INUSE) {
+		uint32_t len;
+
+		/* skip netid string */
+		p = xdr_inline_decode(xdr, 4);
+		if (unlikely(!p))
+			return -EIO;
+		len = be32_to_cpup(p);
+		p = xdr_inline_decode(xdr, len);
+		if (unlikely(!p))
+			return -EIO;
+
+		/* skip uaddr string */
+		p = xdr_inline_decode(xdr, 4);
+		if (unlikely(!p))
+			return -EIO;
+		len = be32_to_cpup(p);
+		p = xdr_inline_decode(xdr, len);
+		if (unlikely(!p))
+			return -EIO;
+		return -NFSERR_CLID_INUSE;
+	} else
+		return nfs4_stat_to_errno(nfserr);
+
+	return 0;
+}
+
+static int decode_setclientid_confirm(struct xdr_stream *xdr)
+{
+	return decode_op_hdr(xdr, OP_SETCLIENTID_CONFIRM);
+}
+
+static int decode_write(struct xdr_stream *xdr, struct nfs_pgio_res *res)
+{
+	__be32 *p;
+	int status;
+
+	status = decode_op_hdr(xdr, OP_WRITE);
+	if (status)
+		return status;
+
+	p = xdr_inline_decode(xdr, 8);
+	if (unlikely(!p))
+		return -EIO;
+	res->count = be32_to_cpup(p++);
+	res->verf->committed = be32_to_cpup(p++);
+	return decode_write_verifier(xdr, &res->verf->verifier);
+}
+
+static int decode_delegreturn(struct xdr_stream *xdr)
+{
+	return decode_op_hdr(xdr, OP_DELEGRETURN);
+}
+
+static int decode_secinfo_gss(struct xdr_stream *xdr,
+			      struct nfs4_secinfo4 *flavor)
+{
+	u32 oid_len;
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(!p))
+		return -EIO;
+	oid_len = be32_to_cpup(p);
+	if (oid_len > GSS_OID_MAX_LEN)
+		return -EINVAL;
+
+	p = xdr_inline_decode(xdr, oid_len);
+	if (unlikely(!p))
+		return -EIO;
+	memcpy(flavor->flavor_info.oid.data, p, oid_len);
+	flavor->flavor_info.oid.len = oid_len;
+
+	p = xdr_inline_decode(xdr, 8);
+	if (unlikely(!p))
+		return -EIO;
+	flavor->flavor_info.qop = be32_to_cpup(p++);
+	flavor->flavor_info.service = be32_to_cpup(p);
+
+	return 0;
+}
+
+static int decode_secinfo_common(struct xdr_stream *xdr, struct nfs4_secinfo_res *res)
+{
+	struct nfs4_secinfo4 *sec_flavor;
+	unsigned int i, num_flavors;
+	int status;
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(!p))
+		return -EIO;
+
+	res->flavors->num_flavors = 0;
+	num_flavors = be32_to_cpup(p);
+
+	for (i = 0; i < num_flavors; i++) {
+		sec_flavor = &res->flavors->flavors[i];
+		if ((char *)&sec_flavor[1] - (char *)res->flavors > PAGE_SIZE)
+			break;
+
+		p = xdr_inline_decode(xdr, 4);
+		if (unlikely(!p))
+			return -EIO;
+		sec_flavor->flavor = be32_to_cpup(p);
+
+		if (sec_flavor->flavor == RPC_AUTH_GSS) {
+			status = decode_secinfo_gss(xdr, sec_flavor);
+			if (status)
+				goto out;
+		}
+		res->flavors->num_flavors++;
+	}
+
+	status = 0;
+out:
+	return status;
+}
+
+static int decode_secinfo(struct xdr_stream *xdr, struct nfs4_secinfo_res *res)
+{
+	int status = decode_op_hdr(xdr, OP_SECINFO);
+	if (status)
+		return status;
+	return decode_secinfo_common(xdr, res);
+}
+
+#if defined(CONFIG_NFS_V4_1)
+static int decode_secinfo_no_name(struct xdr_stream *xdr, struct nfs4_secinfo_res *res)
+{
+	int status = decode_op_hdr(xdr, OP_SECINFO_NO_NAME);
+	if (status)
+		return status;
+	return decode_secinfo_common(xdr, res);
+}
+
+static int decode_op_map(struct xdr_stream *xdr, struct nfs4_op_map *op_map)
+{
+	__be32 *p;
+	uint32_t bitmap_words;
+	unsigned int i;
+
+	p = xdr_inline_decode(xdr, 4);
+	if (!p)
+		return -EIO;
+	bitmap_words = be32_to_cpup(p++);
+	if (bitmap_words > NFS4_OP_MAP_NUM_WORDS)
+		return -EIO;
+	p = xdr_inline_decode(xdr, 4 * bitmap_words);
+	for (i = 0; i < bitmap_words; i++)
+		op_map->u.words[i] = be32_to_cpup(p++);
+
+	return 0;
+}
+
+static int decode_exchange_id(struct xdr_stream *xdr,
+			      struct nfs41_exchange_id_res *res)
+{
+	__be32 *p;
+	uint32_t dummy;
+	char *dummy_str;
+	int status;
+	uint32_t impl_id_count;
+
+	status = decode_op_hdr(xdr, OP_EXCHANGE_ID);
+	if (status)
+		return status;
+
+	p = xdr_inline_decode(xdr, 8);
+	if (unlikely(!p))
+		return -EIO;
+	xdr_decode_hyper(p, &res->clientid);
+	p = xdr_inline_decode(xdr, 12);
+	if (unlikely(!p))
+		return -EIO;
+	res->seqid = be32_to_cpup(p++);
+	res->flags = be32_to_cpup(p++);
+
+	res->state_protect.how = be32_to_cpup(p);
+	switch (res->state_protect.how) {
+	case SP4_NONE:
+		break;
+	case SP4_MACH_CRED:
+		status = decode_op_map(xdr, &res->state_protect.enforce);
+		if (status)
+			return status;
+		status = decode_op_map(xdr, &res->state_protect.allow);
+		if (status)
+			return status;
+		break;
+	default:
+		WARN_ON_ONCE(1);
+		return -EIO;
+	}
+
+	/* server_owner4.so_minor_id */
+	p = xdr_inline_decode(xdr, 8);
+	if (unlikely(!p))
+		return -EIO;
+	p = xdr_decode_hyper(p, &res->server_owner->minor_id);
+
+	/* server_owner4.so_major_id */
+	status = decode_opaque_inline(xdr, &dummy, &dummy_str);
+	if (unlikely(status))
+		return status;
+	memcpy(res->server_owner->major_id, dummy_str, dummy);
+	res->server_owner->major_id_sz = dummy;
+
+	/* server_scope4 */
+	status = decode_opaque_inline(xdr, &dummy, &dummy_str);
+	if (unlikely(status))
+		return status;
+	memcpy(res->server_scope->server_scope, dummy_str, dummy);
+	res->server_scope->server_scope_sz = dummy;
+
+	/* Implementation Id */
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(!p))
+		return -EIO;
+	impl_id_count = be32_to_cpup(p++);
+
+	if (impl_id_count) {
+		/* nii_domain */
+		status = decode_opaque_inline(xdr, &dummy, &dummy_str);
+		if (unlikely(status))
+			return status;
+		memcpy(res->impl_id->domain, dummy_str, dummy);
+
+		/* nii_name */
+		status = decode_opaque_inline(xdr, &dummy, &dummy_str);
+		if (unlikely(status))
+			return status;
+		memcpy(res->impl_id->name, dummy_str, dummy);
+
+		/* nii_date */
+		p = xdr_inline_decode(xdr, 12);
+		if (unlikely(!p))
+			return -EIO;
+		p = xdr_decode_hyper(p, &res->impl_id->date.seconds);
+		res->impl_id->date.nseconds = be32_to_cpup(p);
+
+		/* if there's more than one entry, ignore the rest */
+	}
+	return 0;
+}
+
+static int decode_chan_attrs(struct xdr_stream *xdr,
+			     struct nfs4_channel_attrs *attrs)
+{
+	__be32 *p;
+	u32 nr_attrs, val;
+
+	p = xdr_inline_decode(xdr, 28);
+	if (unlikely(!p))
+		return -EIO;
+	val = be32_to_cpup(p++);	/* headerpadsz */
+	if (val)
+		return -EINVAL;		/* no support for header padding yet */
+	attrs->max_rqst_sz = be32_to_cpup(p++);
+	attrs->max_resp_sz = be32_to_cpup(p++);
+	attrs->max_resp_sz_cached = be32_to_cpup(p++);
+	attrs->max_ops = be32_to_cpup(p++);
+	attrs->max_reqs = be32_to_cpup(p++);
+	nr_attrs = be32_to_cpup(p);
+	if (unlikely(nr_attrs > 1)) {
+		printk(KERN_WARNING "NFS: %s: Invalid rdma channel attrs "
+			"count %u\n", __func__, nr_attrs);
+		return -EINVAL;
+	}
+	if (nr_attrs == 1) {
+		p = xdr_inline_decode(xdr, 4); /* skip rdma_attrs */
+		if (unlikely(!p))
+			return -EIO;
+	}
+	return 0;
+}
+
+static int decode_sessionid(struct xdr_stream *xdr, struct nfs4_sessionid *sid)
+{
+	return decode_opaque_fixed(xdr, sid->data, NFS4_MAX_SESSIONID_LEN);
+}
+
+static int decode_bind_conn_to_session(struct xdr_stream *xdr,
+				struct nfs41_bind_conn_to_session_res *res)
+{
+	__be32 *p;
+	int status;
+
+	status = decode_op_hdr(xdr, OP_BIND_CONN_TO_SESSION);
+	if (!status)
+		status = decode_sessionid(xdr, &res->sessionid);
+	if (unlikely(status))
+		return status;
+
+	/* dir flags, rdma mode bool */
+	p = xdr_inline_decode(xdr, 8);
+	if (unlikely(!p))
+		return -EIO;
+
+	res->dir = be32_to_cpup(p++);
+	if (res->dir == 0 || res->dir > NFS4_CDFS4_BOTH)
+		return -EIO;
+	if (be32_to_cpup(p) == 0)
+		res->use_conn_in_rdma_mode = false;
+	else
+		res->use_conn_in_rdma_mode = true;
+
+	return 0;
+}
+
+static int decode_create_session(struct xdr_stream *xdr,
+				 struct nfs41_create_session_res *res)
+{
+	__be32 *p;
+	int status;
+
+	status = decode_op_hdr(xdr, OP_CREATE_SESSION);
+	if (!status)
+		status = decode_sessionid(xdr, &res->sessionid);
+	if (unlikely(status))
+		return status;
+
+	/* seqid, flags */
+	p = xdr_inline_decode(xdr, 8);
+	if (unlikely(!p))
+		return -EIO;
+	res->seqid = be32_to_cpup(p++);
+	res->flags = be32_to_cpup(p);
+
+	/* Channel attributes */
+	status = decode_chan_attrs(xdr, &res->fc_attrs);
+	if (!status)
+		status = decode_chan_attrs(xdr, &res->bc_attrs);
+	return status;
+}
+
+static int decode_destroy_session(struct xdr_stream *xdr, void *dummy)
+{
+	return decode_op_hdr(xdr, OP_DESTROY_SESSION);
+}
+
+static int decode_destroy_clientid(struct xdr_stream *xdr, void *dummy)
+{
+	return decode_op_hdr(xdr, OP_DESTROY_CLIENTID);
+}
+
+static int decode_reclaim_complete(struct xdr_stream *xdr, void *dummy)
+{
+	return decode_op_hdr(xdr, OP_RECLAIM_COMPLETE);
+}
+#endif /* CONFIG_NFS_V4_1 */
+
+static int decode_sequence(struct xdr_stream *xdr,
+			   struct nfs4_sequence_res *res,
+			   struct rpc_rqst *rqstp)
+{
+#if defined(CONFIG_NFS_V4_1)
+	struct nfs4_session *session;
+	struct nfs4_sessionid id;
+	u32 dummy;
+	int status;
+	__be32 *p;
+
+	if (res->sr_slot == NULL)
+		return 0;
+	if (!res->sr_slot->table->session)
+		return 0;
+
+	status = decode_op_hdr(xdr, OP_SEQUENCE);
+	if (!status)
+		status = decode_sessionid(xdr, &id);
+	if (unlikely(status))
+		goto out_err;
+
+	/*
+	 * If the server returns different values for sessionID, slotID or
+	 * sequence number, the server is looney tunes.
+	 */
+	status = -EREMOTEIO;
+	session = res->sr_slot->table->session;
+
+	if (memcmp(id.data, session->sess_id.data,
+		   NFS4_MAX_SESSIONID_LEN)) {
+		dprintk("%s Invalid session id\n", __func__);
+		goto out_err;
+	}
+
+	p = xdr_inline_decode(xdr, 20);
+	if (unlikely(!p))
+		goto out_overflow;
+
+	/* seqid */
+	dummy = be32_to_cpup(p++);
+	if (dummy != res->sr_slot->seq_nr) {
+		dprintk("%s Invalid sequence number\n", __func__);
+		goto out_err;
+	}
+	/* slot id */
+	dummy = be32_to_cpup(p++);
+	if (dummy != res->sr_slot->slot_nr) {
+		dprintk("%s Invalid slot id\n", __func__);
+		goto out_err;
+	}
+	/* highest slot id */
+	res->sr_highest_slotid = be32_to_cpup(p++);
+	/* target highest slot id */
+	res->sr_target_highest_slotid = be32_to_cpup(p++);
+	/* result flags */
+	res->sr_status_flags = be32_to_cpup(p);
+	status = 0;
+out_err:
+	res->sr_status = status;
+	return status;
+out_overflow:
+	status = -EIO;
+	goto out_err;
+#else  /* CONFIG_NFS_V4_1 */
+	return 0;
+#endif /* CONFIG_NFS_V4_1 */
+}
+
+#if defined(CONFIG_NFS_V4_1)
+static int decode_layout_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
+{
+	stateid->type = NFS4_LAYOUT_STATEID_TYPE;
+	return decode_stateid(xdr, stateid);
+}
+
+static int decode_getdeviceinfo(struct xdr_stream *xdr,
+				struct nfs4_getdeviceinfo_res *res)
+{
+	struct pnfs_device *pdev = res->pdev;
+	__be32 *p;
+	uint32_t len, type;
+	int status;
+
+	status = decode_op_hdr(xdr, OP_GETDEVICEINFO);
+	if (status) {
+		if (status == -ETOOSMALL) {
+			p = xdr_inline_decode(xdr, 4);
+			if (unlikely(!p))
+				return -EIO;
+			pdev->mincount = be32_to_cpup(p);
+			dprintk("%s: Min count too small. mincnt = %u\n",
+				__func__, pdev->mincount);
+		}
+		return status;
+	}
+
+	p = xdr_inline_decode(xdr, 8);
+	if (unlikely(!p))
+		return -EIO;
+	type = be32_to_cpup(p++);
+	if (type != pdev->layout_type) {
+		dprintk("%s: layout mismatch req: %u pdev: %u\n",
+			__func__, pdev->layout_type, type);
+		return -EINVAL;
+	}
+	/*
+	 * Get the length of the opaque device_addr4. xdr_read_pages places
+	 * the opaque device_addr4 in the xdr_buf->pages (pnfs_device->pages)
+	 * and places the remaining xdr data in xdr_buf->tail
+	 */
+	pdev->mincount = be32_to_cpup(p);
+	if (xdr_read_pages(xdr, pdev->mincount) != pdev->mincount)
+		return -EIO;
+
+	/* Parse notification bitmap, verifying that it is zero. */
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(!p))
+		return -EIO;
+	len = be32_to_cpup(p);
+	if (len) {
+		uint32_t i;
+
+		p = xdr_inline_decode(xdr, 4 * len);
+		if (unlikely(!p))
+			return -EIO;
+
+		res->notification = be32_to_cpup(p++);
+		for (i = 1; i < len; i++) {
+			if (be32_to_cpup(p++)) {
+				dprintk("%s: unsupported notification\n",
+					__func__);
+				return -EIO;
+			}
+		}
+	}
+	return 0;
+}
+
+static int decode_layoutget(struct xdr_stream *xdr, struct rpc_rqst *req,
+			    struct nfs4_layoutget_res *res)
+{
+	__be32 *p;
+	int status;
+	u32 layout_count;
+	u32 recvd;
+
+	status = decode_op_hdr(xdr, OP_LAYOUTGET);
+	if (status)
+		goto out;
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(!p))
+		goto out_overflow;
+	res->return_on_close = be32_to_cpup(p);
+	decode_layout_stateid(xdr, &res->stateid);
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(!p))
+		goto out_overflow;
+	layout_count = be32_to_cpup(p);
+	if (!layout_count) {
+		dprintk("%s: server responded with empty layout array\n",
+			__func__);
+		status = -EINVAL;
+		goto out;
+	}
+
+	p = xdr_inline_decode(xdr, 28);
+	if (unlikely(!p))
+		goto out_overflow;
+	p = xdr_decode_hyper(p, &res->range.offset);
+	p = xdr_decode_hyper(p, &res->range.length);
+	res->range.iomode = be32_to_cpup(p++);
+	res->type = be32_to_cpup(p++);
+	res->layoutp->len = be32_to_cpup(p);
+
+	dprintk("%s roff:%lu rlen:%lu riomode:%d, lo_type:0x%x, lo.len:%d\n",
+		__func__,
+		(unsigned long)res->range.offset,
+		(unsigned long)res->range.length,
+		res->range.iomode,
+		res->type,
+		res->layoutp->len);
+
+	recvd = xdr_read_pages(xdr, res->layoutp->len);
+	if (res->layoutp->len > recvd) {
+		dprintk("NFS: server cheating in layoutget reply: "
+				"layout len %u > recvd %u\n",
+				res->layoutp->len, recvd);
+		status = -EINVAL;
+		goto out;
+	}
+
+	if (layout_count > 1) {
+		/* We only handle a length one array at the moment.  Any
+		 * further entries are just ignored.  Note that this means
+		 * the client may see a response that is less than the
+		 * minimum it requested.
+		 */
+		dprintk("%s: server responded with %d layouts, dropping tail\n",
+			__func__, layout_count);
+	}
+
+out:
+	res->status = status;
+	return status;
+out_overflow:
+	status = -EIO;
+	goto out;
+}
+
+static int decode_layoutreturn(struct xdr_stream *xdr,
+			       struct nfs4_layoutreturn_res *res)
+{
+	__be32 *p;
+	int status;
+
+	status = decode_op_hdr(xdr, OP_LAYOUTRETURN);
+	if (status)
+		return status;
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(!p))
+		return -EIO;
+	res->lrs_present = be32_to_cpup(p);
+	if (res->lrs_present)
+		status = decode_layout_stateid(xdr, &res->stateid);
+	else
+		nfs4_stateid_copy(&res->stateid, &invalid_stateid);
+	return status;
+}
+
+static int decode_layoutcommit(struct xdr_stream *xdr,
+			       struct rpc_rqst *req,
+			       struct nfs4_layoutcommit_res *res)
+{
+	__be32 *p;
+	__u32 sizechanged;
+	int status;
+
+	status = decode_op_hdr(xdr, OP_LAYOUTCOMMIT);
+	res->status = status;
+	if (status)
+		return status;
+
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(!p))
+		return -EIO;
+	sizechanged = be32_to_cpup(p);
+
+	if (sizechanged) {
+		/* throw away new size */
+		p = xdr_inline_decode(xdr, 8);
+		if (unlikely(!p))
+			return -EIO;
+	}
+	return 0;
+}
+
+static int decode_test_stateid(struct xdr_stream *xdr,
+			       struct nfs41_test_stateid_res *res)
+{
+	__be32 *p;
+	int status;
+	int num_res;
+
+	status = decode_op_hdr(xdr, OP_TEST_STATEID);
+	if (status)
+		return status;
+
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(!p))
+		return -EIO;
+	num_res = be32_to_cpup(p++);
+	if (num_res != 1)
+		return -EIO;
+
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(!p))
+		return -EIO;
+	res->status = be32_to_cpup(p++);
+
+	return status;
+}
+
+static int decode_free_stateid(struct xdr_stream *xdr,
+			       struct nfs41_free_stateid_res *res)
+{
+	res->status = decode_op_hdr(xdr, OP_FREE_STATEID);
+	return res->status;
+}
+#else
+static inline
+int decode_layoutreturn(struct xdr_stream *xdr,
+			       struct nfs4_layoutreturn_res *res)
+{
+	return 0;
+}
+
+static int decode_layoutget(struct xdr_stream *xdr, struct rpc_rqst *req,
+			    struct nfs4_layoutget_res *res)
+{
+	return 0;
+}
+
+#endif /* CONFIG_NFS_V4_1 */
+
+/*
+ * END OF "GENERIC" DECODE ROUTINES.
+ */
+
+/*
+ * Decode OPEN_DOWNGRADE response
+ */
+static int nfs4_xdr_dec_open_downgrade(struct rpc_rqst *rqstp,
+				       struct xdr_stream *xdr,
+				       void *data)
+{
+	struct nfs_closeres *res = data;
+	struct compound_hdr hdr;
+	int status;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	if (status)
+		goto out;
+	status = decode_sequence(xdr, &res->seq_res, rqstp);
+	if (status)
+		goto out;
+	status = decode_putfh(xdr);
+	if (status)
+		goto out;
+	if (res->lr_res) {
+		status = decode_layoutreturn(xdr, res->lr_res);
+		res->lr_ret = status;
+		if (status)
+			goto out;
+	}
+	status = decode_open_downgrade(xdr, res);
+out:
+	return status;
+}
+
+/*
+ * Decode ACCESS response
+ */
+static int nfs4_xdr_dec_access(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
+			       void *data)
+{
+	struct nfs4_accessres *res = data;
+	struct compound_hdr hdr;
+	int status;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	if (status)
+		goto out;
+	status = decode_sequence(xdr, &res->seq_res, rqstp);
+	if (status)
+		goto out;
+	status = decode_putfh(xdr);
+	if (status != 0)
+		goto out;
+	status = decode_access(xdr, &res->supported, &res->access);
+	if (status != 0)
+		goto out;
+	if (res->fattr)
+		decode_getfattr(xdr, res->fattr, res->server);
+out:
+	return status;
+}
+
+/*
+ * Decode LOOKUP response
+ */
+static int nfs4_xdr_dec_lookup(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
+			       void *data)
+{
+	struct nfs4_lookup_res *res = data;
+	struct compound_hdr hdr;
+	int status;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	if (status)
+		goto out;
+	status = decode_sequence(xdr, &res->seq_res, rqstp);
+	if (status)
+		goto out;
+	status = decode_putfh(xdr);
+	if (status)
+		goto out;
+	status = decode_lookup(xdr);
+	if (status)
+		goto out;
+	status = decode_getfh(xdr, res->fh);
+	if (status)
+		goto out;
+	status = decode_getfattr_label(xdr, res->fattr, res->label, res->server);
+out:
+	return status;
+}
+
+/*
+ * Decode LOOKUPP response
+ */
+static int nfs4_xdr_dec_lookupp(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
+		void *data)
+{
+	struct nfs4_lookupp_res *res = data;
+	struct compound_hdr hdr;
+	int status;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	if (status)
+		goto out;
+	status = decode_sequence(xdr, &res->seq_res, rqstp);
+	if (status)
+		goto out;
+	status = decode_putfh(xdr);
+	if (status)
+		goto out;
+	status = decode_lookupp(xdr);
+	if (status)
+		goto out;
+	status = decode_getfh(xdr, res->fh);
+	if (status)
+		goto out;
+	status = decode_getfattr_label(xdr, res->fattr, res->label, res->server);
+out:
+	return status;
+}
+
+/*
+ * Decode LOOKUP_ROOT response
+ */
+static int nfs4_xdr_dec_lookup_root(struct rpc_rqst *rqstp,
+				    struct xdr_stream *xdr,
+				    void *data)
+{
+	struct nfs4_lookup_res *res = data;
+	struct compound_hdr hdr;
+	int status;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	if (status)
+		goto out;
+	status = decode_sequence(xdr, &res->seq_res, rqstp);
+	if (status)
+		goto out;
+	status = decode_putrootfh(xdr);
+	if (status)
+		goto out;
+	status = decode_getfh(xdr, res->fh);
+	if (status == 0)
+		status = decode_getfattr_label(xdr, res->fattr,
+						res->label, res->server);
+out:
+	return status;
+}
+
+/*
+ * Decode REMOVE response
+ */
+static int nfs4_xdr_dec_remove(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
+			       void *data)
+{
+	struct nfs_removeres *res = data;
+	struct compound_hdr hdr;
+	int status;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	if (status)
+		goto out;
+	status = decode_sequence(xdr, &res->seq_res, rqstp);
+	if (status)
+		goto out;
+	status = decode_putfh(xdr);
+	if (status)
+		goto out;
+	status = decode_remove(xdr, &res->cinfo);
+out:
+	return status;
+}
+
+/*
+ * Decode RENAME response
+ */
+static int nfs4_xdr_dec_rename(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
+			       void *data)
+{
+	struct nfs_renameres *res = data;
+	struct compound_hdr hdr;
+	int status;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	if (status)
+		goto out;
+	status = decode_sequence(xdr, &res->seq_res, rqstp);
+	if (status)
+		goto out;
+	status = decode_putfh(xdr);
+	if (status)
+		goto out;
+	status = decode_savefh(xdr);
+	if (status)
+		goto out;
+	status = decode_putfh(xdr);
+	if (status)
+		goto out;
+	status = decode_rename(xdr, &res->old_cinfo, &res->new_cinfo);
+out:
+	return status;
+}
+
+/*
+ * Decode LINK response
+ */
+static int nfs4_xdr_dec_link(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
+			     void *data)
+{
+	struct nfs4_link_res *res = data;
+	struct compound_hdr hdr;
+	int status;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	if (status)
+		goto out;
+	status = decode_sequence(xdr, &res->seq_res, rqstp);
+	if (status)
+		goto out;
+	status = decode_putfh(xdr);
+	if (status)
+		goto out;
+	status = decode_savefh(xdr);
+	if (status)
+		goto out;
+	status = decode_putfh(xdr);
+	if (status)
+		goto out;
+	status = decode_link(xdr, &res->cinfo);
+	if (status)
+		goto out;
+	/*
+	 * Note order: OP_LINK leaves the directory as the current
+	 *             filehandle.
+	 */
+	status = decode_restorefh(xdr);
+	if (status)
+		goto out;
+	decode_getfattr_label(xdr, res->fattr, res->label, res->server);
+out:
+	return status;
+}
+
+/*
+ * Decode CREATE response
+ */
+static int nfs4_xdr_dec_create(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
+			       void *data)
+{
+	struct nfs4_create_res *res = data;
+	struct compound_hdr hdr;
+	int status;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	if (status)
+		goto out;
+	status = decode_sequence(xdr, &res->seq_res, rqstp);
+	if (status)
+		goto out;
+	status = decode_putfh(xdr);
+	if (status)
+		goto out;
+	status = decode_create(xdr, &res->dir_cinfo);
+	if (status)
+		goto out;
+	status = decode_getfh(xdr, res->fh);
+	if (status)
+		goto out;
+	decode_getfattr_label(xdr, res->fattr, res->label, res->server);
+out:
+	return status;
+}
+
+/*
+ * Decode SYMLINK response
+ */
+static int nfs4_xdr_dec_symlink(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
+				void *res)
+{
+	return nfs4_xdr_dec_create(rqstp, xdr, res);
+}
+
+/*
+ * Decode GETATTR response
+ */
+static int nfs4_xdr_dec_getattr(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
+				void *data)
+{
+	struct nfs4_getattr_res *res = data;
+	struct compound_hdr hdr;
+	int status;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	if (status)
+		goto out;
+	status = decode_sequence(xdr, &res->seq_res, rqstp);
+	if (status)
+		goto out;
+	status = decode_putfh(xdr);
+	if (status)
+		goto out;
+	status = decode_getfattr_label(xdr, res->fattr, res->label, res->server);
+out:
+	return status;
+}
+
+/*
+ * Encode an SETACL request
+ */
+static void nfs4_xdr_enc_setacl(struct rpc_rqst *req, struct xdr_stream *xdr,
+				const void *data)
+{
+	const struct nfs_setaclargs *args = data;
+	struct compound_hdr hdr = {
+		.minorversion = nfs4_xdr_minorversion(&args->seq_args),
+	};
+
+	encode_compound_hdr(xdr, req, &hdr);
+	encode_sequence(xdr, &args->seq_args, &hdr);
+	encode_putfh(xdr, args->fh, &hdr);
+	encode_setacl(xdr, args, &hdr);
+	encode_nops(&hdr);
+}
+
+/*
+ * Decode SETACL response
+ */
+static int
+nfs4_xdr_dec_setacl(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
+		    void *data)
+{
+	struct nfs_setaclres *res = data;
+	struct compound_hdr hdr;
+	int status;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	if (status)
+		goto out;
+	status = decode_sequence(xdr, &res->seq_res, rqstp);
+	if (status)
+		goto out;
+	status = decode_putfh(xdr);
+	if (status)
+		goto out;
+	status = decode_setattr(xdr);
+out:
+	return status;
+}
+
+/*
+ * Decode GETACL response
+ */
+static int
+nfs4_xdr_dec_getacl(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
+		    void *data)
+{
+	struct nfs_getaclres *res = data;
+	struct compound_hdr hdr;
+	int status;
+
+	if (res->acl_scratch != NULL) {
+		void *p = page_address(res->acl_scratch);
+		xdr_set_scratch_buffer(xdr, p, PAGE_SIZE);
+	}
+	status = decode_compound_hdr(xdr, &hdr);
+	if (status)
+		goto out;
+	status = decode_sequence(xdr, &res->seq_res, rqstp);
+	if (status)
+		goto out;
+	status = decode_putfh(xdr);
+	if (status)
+		goto out;
+	status = decode_getacl(xdr, rqstp, res);
+
+out:
+	return status;
+}
+
+/*
+ * Decode CLOSE response
+ */
+static int nfs4_xdr_dec_close(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
+			      void *data)
+{
+	struct nfs_closeres *res = data;
+	struct compound_hdr hdr;
+	int status;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	if (status)
+		goto out;
+	status = decode_sequence(xdr, &res->seq_res, rqstp);
+	if (status)
+		goto out;
+	status = decode_putfh(xdr);
+	if (status)
+		goto out;
+	if (res->lr_res) {
+		status = decode_layoutreturn(xdr, res->lr_res);
+		res->lr_ret = status;
+		if (status)
+			goto out;
+	}
+	if (res->fattr != NULL) {
+		status = decode_getfattr(xdr, res->fattr, res->server);
+		if (status != 0)
+			goto out;
+	}
+	status = decode_close(xdr, res);
+out:
+	return status;
+}
+
+/*
+ * Decode OPEN response
+ */
+static int nfs4_xdr_dec_open(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
+			     void *data)
+{
+	struct nfs_openres *res = data;
+	struct compound_hdr hdr;
+	int status;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	if (status)
+		goto out;
+	status = decode_sequence(xdr, &res->seq_res, rqstp);
+	if (status)
+		goto out;
+	status = decode_putfh(xdr);
+	if (status)
+		goto out;
+	status = decode_open(xdr, res);
+	if (status)
+		goto out;
+	status = decode_getfh(xdr, &res->fh);
+	if (status)
+		goto out;
+	if (res->access_request)
+		decode_access(xdr, &res->access_supported, &res->access_result);
+	decode_getfattr_label(xdr, res->f_attr, res->f_label, res->server);
+	if (res->lg_res)
+		decode_layoutget(xdr, rqstp, res->lg_res);
+out:
+	return status;
+}
+
+/*
+ * Decode OPEN_CONFIRM response
+ */
+static int nfs4_xdr_dec_open_confirm(struct rpc_rqst *rqstp,
+				     struct xdr_stream *xdr,
+				     void *data)
+{
+	struct nfs_open_confirmres *res = data;
+	struct compound_hdr hdr;
+	int status;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	if (status)
+		goto out;
+	status = decode_putfh(xdr);
+	if (status)
+		goto out;
+	status = decode_open_confirm(xdr, res);
+out:
+	return status;
+}
+
+/*
+ * Decode OPEN response
+ */
+static int nfs4_xdr_dec_open_noattr(struct rpc_rqst *rqstp,
+				    struct xdr_stream *xdr,
+				    void *data)
+{
+	struct nfs_openres *res = data;
+	struct compound_hdr hdr;
+	int status;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	if (status)
+		goto out;
+	status = decode_sequence(xdr, &res->seq_res, rqstp);
+	if (status)
+		goto out;
+	status = decode_putfh(xdr);
+	if (status)
+		goto out;
+	status = decode_open(xdr, res);
+	if (status)
+		goto out;
+	if (res->access_request)
+		decode_access(xdr, &res->access_supported, &res->access_result);
+	decode_getfattr(xdr, res->f_attr, res->server);
+	if (res->lg_res)
+		decode_layoutget(xdr, rqstp, res->lg_res);
+out:
+	return status;
+}
+
+/*
+ * Decode SETATTR response
+ */
+static int nfs4_xdr_dec_setattr(struct rpc_rqst *rqstp,
+				struct xdr_stream *xdr,
+				void *data)
+{
+	struct nfs_setattrres *res = data;
+	struct compound_hdr hdr;
+	int status;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	if (status)
+		goto out;
+	status = decode_sequence(xdr, &res->seq_res, rqstp);
+	if (status)
+		goto out;
+	status = decode_putfh(xdr);
+	if (status)
+		goto out;
+	status = decode_setattr(xdr);
+	if (status)
+		goto out;
+	decode_getfattr_label(xdr, res->fattr, res->label, res->server);
+out:
+	return status;
+}
+
+/*
+ * Decode LOCK response
+ */
+static int nfs4_xdr_dec_lock(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
+			     void *data)
+{
+	struct nfs_lock_res *res = data;
+	struct compound_hdr hdr;
+	int status;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	if (status)
+		goto out;
+	status = decode_sequence(xdr, &res->seq_res, rqstp);
+	if (status)
+		goto out;
+	status = decode_putfh(xdr);
+	if (status)
+		goto out;
+	status = decode_lock(xdr, res);
+out:
+	return status;
+}
+
+/*
+ * Decode LOCKT response
+ */
+static int nfs4_xdr_dec_lockt(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
+			      void *data)
+{
+	struct nfs_lockt_res *res = data;
+	struct compound_hdr hdr;
+	int status;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	if (status)
+		goto out;
+	status = decode_sequence(xdr, &res->seq_res, rqstp);
+	if (status)
+		goto out;
+	status = decode_putfh(xdr);
+	if (status)
+		goto out;
+	status = decode_lockt(xdr, res);
+out:
+	return status;
+}
+
+/*
+ * Decode LOCKU response
+ */
+static int nfs4_xdr_dec_locku(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
+			      void *data)
+{
+	struct nfs_locku_res *res = data;
+	struct compound_hdr hdr;
+	int status;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	if (status)
+		goto out;
+	status = decode_sequence(xdr, &res->seq_res, rqstp);
+	if (status)
+		goto out;
+	status = decode_putfh(xdr);
+	if (status)
+		goto out;
+	status = decode_locku(xdr, res);
+out:
+	return status;
+}
+
+static int nfs4_xdr_dec_release_lockowner(struct rpc_rqst *rqstp,
+					  struct xdr_stream *xdr, void *dummy)
+{
+	struct compound_hdr hdr;
+	int status;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	if (!status)
+		status = decode_release_lockowner(xdr);
+	return status;
+}
+
+/*
+ * Decode READLINK response
+ */
+static int nfs4_xdr_dec_readlink(struct rpc_rqst *rqstp,
+				 struct xdr_stream *xdr,
+				 void *data)
+{
+	struct nfs4_readlink_res *res = data;
+	struct compound_hdr hdr;
+	int status;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	if (status)
+		goto out;
+	status = decode_sequence(xdr, &res->seq_res, rqstp);
+	if (status)
+		goto out;
+	status = decode_putfh(xdr);
+	if (status)
+		goto out;
+	status = decode_readlink(xdr, rqstp);
+out:
+	return status;
+}
+
+/*
+ * Decode READDIR response
+ */
+static int nfs4_xdr_dec_readdir(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
+				void *data)
+{
+	struct nfs4_readdir_res *res = data;
+	struct compound_hdr hdr;
+	int status;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	if (status)
+		goto out;
+	status = decode_sequence(xdr, &res->seq_res, rqstp);
+	if (status)
+		goto out;
+	status = decode_putfh(xdr);
+	if (status)
+		goto out;
+	status = decode_readdir(xdr, rqstp, res);
+out:
+	return status;
+}
+
+/*
+ * Decode Read response
+ */
+static int nfs4_xdr_dec_read(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
+			     void *data)
+{
+	struct nfs_pgio_res *res = data;
+	struct compound_hdr hdr;
+	int status;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	res->op_status = hdr.status;
+	if (status)
+		goto out;
+	status = decode_sequence(xdr, &res->seq_res, rqstp);
+	if (status)
+		goto out;
+	status = decode_putfh(xdr);
+	if (status)
+		goto out;
+	status = decode_read(xdr, rqstp, res);
+	if (!status)
+		status = res->count;
+out:
+	return status;
+}
+
+/*
+ * Decode WRITE response
+ */
+static int nfs4_xdr_dec_write(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
+			      void *data)
+{
+	struct nfs_pgio_res *res = data;
+	struct compound_hdr hdr;
+	int status;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	res->op_status = hdr.status;
+	if (status)
+		goto out;
+	status = decode_sequence(xdr, &res->seq_res, rqstp);
+	if (status)
+		goto out;
+	status = decode_putfh(xdr);
+	if (status)
+		goto out;
+	status = decode_write(xdr, res);
+	if (status)
+		goto out;
+	if (res->fattr)
+		decode_getfattr(xdr, res->fattr, res->server);
+	if (!status)
+		status = res->count;
+out:
+	return status;
+}
+
+/*
+ * Decode COMMIT response
+ */
+static int nfs4_xdr_dec_commit(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
+			       void *data)
+{
+	struct nfs_commitres *res = data;
+	struct compound_hdr hdr;
+	int status;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	res->op_status = hdr.status;
+	if (status)
+		goto out;
+	status = decode_sequence(xdr, &res->seq_res, rqstp);
+	if (status)
+		goto out;
+	status = decode_putfh(xdr);
+	if (status)
+		goto out;
+	status = decode_commit(xdr, res);
+out:
+	return status;
+}
+
+/*
+ * Decode FSINFO response
+ */
+static int nfs4_xdr_dec_fsinfo(struct rpc_rqst *req, struct xdr_stream *xdr,
+			       void *data)
+{
+	struct nfs4_fsinfo_res *res = data;
+	struct compound_hdr hdr;
+	int status;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	if (!status)
+		status = decode_sequence(xdr, &res->seq_res, req);
+	if (!status)
+		status = decode_putfh(xdr);
+	if (!status)
+		status = decode_fsinfo(xdr, res->fsinfo);
+	return status;
+}
+
+/*
+ * Decode PATHCONF response
+ */
+static int nfs4_xdr_dec_pathconf(struct rpc_rqst *req, struct xdr_stream *xdr,
+				 void *data)
+{
+	struct nfs4_pathconf_res *res = data;
+	struct compound_hdr hdr;
+	int status;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	if (!status)
+		status = decode_sequence(xdr, &res->seq_res, req);
+	if (!status)
+		status = decode_putfh(xdr);
+	if (!status)
+		status = decode_pathconf(xdr, res->pathconf);
+	return status;
+}
+
+/*
+ * Decode STATFS response
+ */
+static int nfs4_xdr_dec_statfs(struct rpc_rqst *req, struct xdr_stream *xdr,
+			       void *data)
+{
+	struct nfs4_statfs_res *res = data;
+	struct compound_hdr hdr;
+	int status;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	if (!status)
+		status = decode_sequence(xdr, &res->seq_res, req);
+	if (!status)
+		status = decode_putfh(xdr);
+	if (!status)
+		status = decode_statfs(xdr, res->fsstat);
+	return status;
+}
+
+/*
+ * Decode GETATTR_BITMAP response
+ */
+static int nfs4_xdr_dec_server_caps(struct rpc_rqst *req,
+				    struct xdr_stream *xdr,
+				    void *data)
+{
+	struct nfs4_server_caps_res *res = data;
+	struct compound_hdr hdr;
+	int status;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	if (status)
+		goto out;
+	status = decode_sequence(xdr, &res->seq_res, req);
+	if (status)
+		goto out;
+	status = decode_putfh(xdr);
+	if (status)
+		goto out;
+	status = decode_server_caps(xdr, res);
+out:
+	return status;
+}
+
+/*
+ * Decode RENEW response
+ */
+static int nfs4_xdr_dec_renew(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
+			      void *__unused)
+{
+	struct compound_hdr hdr;
+	int status;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	if (!status)
+		status = decode_renew(xdr);
+	return status;
+}
+
+/*
+ * Decode SETCLIENTID response
+ */
+static int nfs4_xdr_dec_setclientid(struct rpc_rqst *req,
+				    struct xdr_stream *xdr,
+				    void *data)
+{
+	struct nfs4_setclientid_res *res = data;
+	struct compound_hdr hdr;
+	int status;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	if (!status)
+		status = decode_setclientid(xdr, res);
+	return status;
+}
+
+/*
+ * Decode SETCLIENTID_CONFIRM response
+ */
+static int nfs4_xdr_dec_setclientid_confirm(struct rpc_rqst *req,
+					    struct xdr_stream *xdr,
+					    void *data)
+{
+	struct compound_hdr hdr;
+	int status;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	if (!status)
+		status = decode_setclientid_confirm(xdr);
+	return status;
+}
+
+/*
+ * Decode DELEGRETURN response
+ */
+static int nfs4_xdr_dec_delegreturn(struct rpc_rqst *rqstp,
+				    struct xdr_stream *xdr,
+				    void *data)
+{
+	struct nfs4_delegreturnres *res = data;
+	struct compound_hdr hdr;
+	int status;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	if (status)
+		goto out;
+	status = decode_sequence(xdr, &res->seq_res, rqstp);
+	if (status)
+		goto out;
+	status = decode_putfh(xdr);
+	if (status != 0)
+		goto out;
+	if (res->lr_res) {
+		status = decode_layoutreturn(xdr, res->lr_res);
+		res->lr_ret = status;
+		if (status)
+			goto out;
+	}
+	if (res->fattr) {
+		status = decode_getfattr(xdr, res->fattr, res->server);
+		if (status != 0)
+			goto out;
+	}
+	status = decode_delegreturn(xdr);
+out:
+	return status;
+}
+
+/*
+ * Decode FS_LOCATIONS response
+ */
+static int nfs4_xdr_dec_fs_locations(struct rpc_rqst *req,
+				     struct xdr_stream *xdr,
+				     void *data)
+{
+	struct nfs4_fs_locations_res *res = data;
+	struct compound_hdr hdr;
+	int status;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	if (status)
+		goto out;
+	status = decode_sequence(xdr, &res->seq_res, req);
+	if (status)
+		goto out;
+	status = decode_putfh(xdr);
+	if (status)
+		goto out;
+	if (res->migration) {
+		xdr_enter_page(xdr, PAGE_SIZE);
+		status = decode_getfattr_generic(xdr,
+					&res->fs_locations->fattr,
+					 NULL, res->fs_locations,
+					 NULL, res->fs_locations->server);
+		if (status)
+			goto out;
+		if (res->renew)
+			status = decode_renew(xdr);
+	} else {
+		status = decode_lookup(xdr);
+		if (status)
+			goto out;
+		xdr_enter_page(xdr, PAGE_SIZE);
+		status = decode_getfattr_generic(xdr,
+					&res->fs_locations->fattr,
+					 NULL, res->fs_locations,
+					 NULL, res->fs_locations->server);
+	}
+out:
+	return status;
+}
+
+/*
+ * Decode SECINFO response
+ */
+static int nfs4_xdr_dec_secinfo(struct rpc_rqst *rqstp,
+				struct xdr_stream *xdr,
+				void *data)
+{
+	struct nfs4_secinfo_res *res = data;
+	struct compound_hdr hdr;
+	int status;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	if (status)
+		goto out;
+	status = decode_sequence(xdr, &res->seq_res, rqstp);
+	if (status)
+		goto out;
+	status = decode_putfh(xdr);
+	if (status)
+		goto out;
+	status = decode_secinfo(xdr, res);
+out:
+	return status;
+}
+
+/*
+ * Decode FSID_PRESENT response
+ */
+static int nfs4_xdr_dec_fsid_present(struct rpc_rqst *rqstp,
+				     struct xdr_stream *xdr,
+				     void *data)
+{
+	struct nfs4_fsid_present_res *res = data;
+	struct compound_hdr hdr;
+	int status;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	if (status)
+		goto out;
+	status = decode_sequence(xdr, &res->seq_res, rqstp);
+	if (status)
+		goto out;
+	status = decode_putfh(xdr);
+	if (status)
+		goto out;
+	status = decode_getfh(xdr, res->fh);
+	if (status)
+		goto out;
+	if (res->renew)
+		status = decode_renew(xdr);
+out:
+	return status;
+}
+
+#if defined(CONFIG_NFS_V4_1)
+/*
+ * Decode BIND_CONN_TO_SESSION response
+ */
+static int nfs4_xdr_dec_bind_conn_to_session(struct rpc_rqst *rqstp,
+					struct xdr_stream *xdr,
+					void *res)
+{
+	struct compound_hdr hdr;
+	int status;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	if (!status)
+		status = decode_bind_conn_to_session(xdr, res);
+	return status;
+}
+
+/*
+ * Decode EXCHANGE_ID response
+ */
+static int nfs4_xdr_dec_exchange_id(struct rpc_rqst *rqstp,
+				    struct xdr_stream *xdr,
+				    void *res)
+{
+	struct compound_hdr hdr;
+	int status;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	if (!status)
+		status = decode_exchange_id(xdr, res);
+	return status;
+}
+
+/*
+ * Decode CREATE_SESSION response
+ */
+static int nfs4_xdr_dec_create_session(struct rpc_rqst *rqstp,
+				       struct xdr_stream *xdr,
+				       void *res)
+{
+	struct compound_hdr hdr;
+	int status;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	if (!status)
+		status = decode_create_session(xdr, res);
+	return status;
+}
+
+/*
+ * Decode DESTROY_SESSION response
+ */
+static int nfs4_xdr_dec_destroy_session(struct rpc_rqst *rqstp,
+					struct xdr_stream *xdr,
+					void *res)
+{
+	struct compound_hdr hdr;
+	int status;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	if (!status)
+		status = decode_destroy_session(xdr, res);
+	return status;
+}
+
+/*
+ * Decode DESTROY_CLIENTID response
+ */
+static int nfs4_xdr_dec_destroy_clientid(struct rpc_rqst *rqstp,
+					struct xdr_stream *xdr,
+					void *res)
+{
+	struct compound_hdr hdr;
+	int status;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	if (!status)
+		status = decode_destroy_clientid(xdr, res);
+	return status;
+}
+
+/*
+ * Decode SEQUENCE response
+ */
+static int nfs4_xdr_dec_sequence(struct rpc_rqst *rqstp,
+				 struct xdr_stream *xdr,
+				 void *res)
+{
+	struct compound_hdr hdr;
+	int status;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	if (!status)
+		status = decode_sequence(xdr, res, rqstp);
+	return status;
+}
+
+#endif
+
+/*
+ * Decode GET_LEASE_TIME response
+ */
+static int nfs4_xdr_dec_get_lease_time(struct rpc_rqst *rqstp,
+				       struct xdr_stream *xdr,
+				       void *data)
+{
+	struct nfs4_get_lease_time_res *res = data;
+	struct compound_hdr hdr;
+	int status;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	if (!status)
+		status = decode_sequence(xdr, &res->lr_seq_res, rqstp);
+	if (!status)
+		status = decode_putrootfh(xdr);
+	if (!status)
+		status = decode_fsinfo(xdr, res->lr_fsinfo);
+	return status;
+}
+
+#ifdef CONFIG_NFS_V4_1
+
+/*
+ * Decode RECLAIM_COMPLETE response
+ */
+static int nfs4_xdr_dec_reclaim_complete(struct rpc_rqst *rqstp,
+					 struct xdr_stream *xdr,
+					 void *data)
+{
+	struct nfs41_reclaim_complete_res *res = data;
+	struct compound_hdr hdr;
+	int status;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	if (!status)
+		status = decode_sequence(xdr, &res->seq_res, rqstp);
+	if (!status)
+		status = decode_reclaim_complete(xdr, NULL);
+	return status;
+}
+
+/*
+ * Decode GETDEVINFO response
+ */
+static int nfs4_xdr_dec_getdeviceinfo(struct rpc_rqst *rqstp,
+				      struct xdr_stream *xdr,
+				      void *data)
+{
+	struct nfs4_getdeviceinfo_res *res = data;
+	struct compound_hdr hdr;
+	int status;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	if (status != 0)
+		goto out;
+	status = decode_sequence(xdr, &res->seq_res, rqstp);
+	if (status != 0)
+		goto out;
+	status = decode_getdeviceinfo(xdr, res);
+out:
+	return status;
+}
+
+/*
+ * Decode LAYOUTGET response
+ */
+static int nfs4_xdr_dec_layoutget(struct rpc_rqst *rqstp,
+				  struct xdr_stream *xdr,
+				  void *data)
+{
+	struct nfs4_layoutget_res *res = data;
+	struct compound_hdr hdr;
+	int status;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	if (status)
+		goto out;
+	status = decode_sequence(xdr, &res->seq_res, rqstp);
+	if (status)
+		goto out;
+	status = decode_putfh(xdr);
+	if (status)
+		goto out;
+	status = decode_layoutget(xdr, rqstp, res);
+out:
+	return status;
+}
+
+/*
+ * Decode LAYOUTRETURN response
+ */
+static int nfs4_xdr_dec_layoutreturn(struct rpc_rqst *rqstp,
+				     struct xdr_stream *xdr,
+				     void *data)
+{
+	struct nfs4_layoutreturn_res *res = data;
+	struct compound_hdr hdr;
+	int status;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	if (status)
+		goto out;
+	status = decode_sequence(xdr, &res->seq_res, rqstp);
+	if (status)
+		goto out;
+	status = decode_putfh(xdr);
+	if (status)
+		goto out;
+	status = decode_layoutreturn(xdr, res);
+out:
+	return status;
+}
+
+/*
+ * Decode LAYOUTCOMMIT response
+ */
+static int nfs4_xdr_dec_layoutcommit(struct rpc_rqst *rqstp,
+				     struct xdr_stream *xdr,
+				     void *data)
+{
+	struct nfs4_layoutcommit_res *res = data;
+	struct compound_hdr hdr;
+	int status;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	if (status)
+		goto out;
+	status = decode_sequence(xdr, &res->seq_res, rqstp);
+	if (status)
+		goto out;
+	status = decode_putfh(xdr);
+	if (status)
+		goto out;
+	status = decode_layoutcommit(xdr, rqstp, res);
+	if (status)
+		goto out;
+	decode_getfattr(xdr, res->fattr, res->server);
+out:
+	return status;
+}
+
+/*
+ * Decode SECINFO_NO_NAME response
+ */
+static int nfs4_xdr_dec_secinfo_no_name(struct rpc_rqst *rqstp,
+					struct xdr_stream *xdr,
+					void *data)
+{
+	struct nfs4_secinfo_res *res = data;
+	struct compound_hdr hdr;
+	int status;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	if (status)
+		goto out;
+	status = decode_sequence(xdr, &res->seq_res, rqstp);
+	if (status)
+		goto out;
+	status = decode_putrootfh(xdr);
+	if (status)
+		goto out;
+	status = decode_secinfo_no_name(xdr, res);
+out:
+	return status;
+}
+
+/*
+ * Decode TEST_STATEID response
+ */
+static int nfs4_xdr_dec_test_stateid(struct rpc_rqst *rqstp,
+				     struct xdr_stream *xdr,
+				     void *data)
+{
+	struct nfs41_test_stateid_res *res = data;
+	struct compound_hdr hdr;
+	int status;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	if (status)
+		goto out;
+	status = decode_sequence(xdr, &res->seq_res, rqstp);
+	if (status)
+		goto out;
+	status = decode_test_stateid(xdr, res);
+out:
+	return status;
+}
+
+/*
+ * Decode FREE_STATEID response
+ */
+static int nfs4_xdr_dec_free_stateid(struct rpc_rqst *rqstp,
+				     struct xdr_stream *xdr,
+				     void *data)
+{
+	struct nfs41_free_stateid_res *res = data;
+	struct compound_hdr hdr;
+	int status;
+
+	status = decode_compound_hdr(xdr, &hdr);
+	if (status)
+		goto out;
+	status = decode_sequence(xdr, &res->seq_res, rqstp);
+	if (status)
+		goto out;
+	status = decode_free_stateid(xdr, res);
+out:
+	return status;
+}
+#endif /* CONFIG_NFS_V4_1 */
+
+/**
+ * nfs4_decode_dirent - Decode a single NFSv4 directory entry stored in
+ *                      the local page cache.
+ * @xdr: XDR stream where entry resides
+ * @entry: buffer to fill in with entry data
+ * @plus: boolean indicating whether this should be a readdirplus entry
+ *
+ * Returns zero if successful, otherwise a negative errno value is
+ * returned.
+ *
+ * This function is not invoked during READDIR reply decoding, but
+ * rather whenever an application invokes the getdents(2) system call
+ * on a directory already in our cache.
+ */
+int nfs4_decode_dirent(struct xdr_stream *xdr, struct nfs_entry *entry,
+		       bool plus)
+{
+	unsigned int savep;
+	uint32_t bitmap[3] = {0};
+	uint32_t len;
+	uint64_t new_cookie;
+	__be32 *p = xdr_inline_decode(xdr, 4);
+	if (unlikely(!p))
+		return -EAGAIN;
+	if (*p == xdr_zero) {
+		p = xdr_inline_decode(xdr, 4);
+		if (unlikely(!p))
+			return -EAGAIN;
+		if (*p == xdr_zero)
+			return -EAGAIN;
+		entry->eof = 1;
+		return -EBADCOOKIE;
+	}
+
+	p = xdr_inline_decode(xdr, 12);
+	if (unlikely(!p))
+		return -EAGAIN;
+	p = xdr_decode_hyper(p, &new_cookie);
+	entry->len = be32_to_cpup(p);
+
+	p = xdr_inline_decode(xdr, entry->len);
+	if (unlikely(!p))
+		return -EAGAIN;
+	entry->name = (const char *) p;
+
+	/*
+	 * In case the server doesn't return an inode number,
+	 * we fake one here.  (We don't use inode number 0,
+	 * since glibc seems to choke on it...)
+	 */
+	entry->ino = 1;
+	entry->fattr->valid = 0;
+
+	if (decode_attr_bitmap(xdr, bitmap) < 0)
+		return -EAGAIN;
+
+	if (decode_attr_length(xdr, &len, &savep) < 0)
+		return -EAGAIN;
+
+	if (decode_getfattr_attrs(xdr, bitmap, entry->fattr, entry->fh,
+			NULL, entry->label, entry->server) < 0)
+		return -EAGAIN;
+	if (entry->fattr->valid & NFS_ATTR_FATTR_MOUNTED_ON_FILEID)
+		entry->ino = entry->fattr->mounted_on_fileid;
+	else if (entry->fattr->valid & NFS_ATTR_FATTR_FILEID)
+		entry->ino = entry->fattr->fileid;
+
+	entry->d_type = DT_UNKNOWN;
+	if (entry->fattr->valid & NFS_ATTR_FATTR_TYPE)
+		entry->d_type = nfs_umode_to_dtype(entry->fattr->mode);
+
+	entry->prev_cookie = entry->cookie;
+	entry->cookie = new_cookie;
+
+	return 0;
+}
+
+/*
+ * We need to translate between nfs status return values and
+ * the local errno values which may not be the same.
+ */
+static struct {
+	int stat;
+	int errno;
+} nfs_errtbl[] = {
+	{ NFS4_OK,		0		},
+	{ NFS4ERR_PERM,		-EPERM		},
+	{ NFS4ERR_NOENT,	-ENOENT		},
+	{ NFS4ERR_IO,		-errno_NFSERR_IO},
+	{ NFS4ERR_NXIO,		-ENXIO		},
+	{ NFS4ERR_ACCESS,	-EACCES		},
+	{ NFS4ERR_EXIST,	-EEXIST		},
+	{ NFS4ERR_XDEV,		-EXDEV		},
+	{ NFS4ERR_NOTDIR,	-ENOTDIR	},
+	{ NFS4ERR_ISDIR,	-EISDIR		},
+	{ NFS4ERR_INVAL,	-EINVAL		},
+	{ NFS4ERR_FBIG,		-EFBIG		},
+	{ NFS4ERR_NOSPC,	-ENOSPC		},
+	{ NFS4ERR_ROFS,		-EROFS		},
+	{ NFS4ERR_MLINK,	-EMLINK		},
+	{ NFS4ERR_NAMETOOLONG,	-ENAMETOOLONG	},
+	{ NFS4ERR_NOTEMPTY,	-ENOTEMPTY	},
+	{ NFS4ERR_DQUOT,	-EDQUOT		},
+	{ NFS4ERR_STALE,	-ESTALE		},
+	{ NFS4ERR_BADHANDLE,	-EBADHANDLE	},
+	{ NFS4ERR_BAD_COOKIE,	-EBADCOOKIE	},
+	{ NFS4ERR_NOTSUPP,	-ENOTSUPP	},
+	{ NFS4ERR_TOOSMALL,	-ETOOSMALL	},
+	{ NFS4ERR_SERVERFAULT,	-EREMOTEIO	},
+	{ NFS4ERR_BADTYPE,	-EBADTYPE	},
+	{ NFS4ERR_LOCKED,	-EAGAIN		},
+	{ NFS4ERR_SYMLINK,	-ELOOP		},
+	{ NFS4ERR_OP_ILLEGAL,	-EOPNOTSUPP	},
+	{ NFS4ERR_DEADLOCK,	-EDEADLK	},
+	{ NFS4ERR_NOXATTR,	-ENODATA	},
+	{ NFS4ERR_XATTR2BIG,	-E2BIG		},
+	{ -1,			-EIO		}
+};
+
+/*
+ * Convert an NFS error code to a local one.
+ * This one is used jointly by NFSv2 and NFSv3.
+ */
+static int
+nfs4_stat_to_errno(int stat)
+{
+	int i;
+	for (i = 0; nfs_errtbl[i].stat != -1; i++) {
+		if (nfs_errtbl[i].stat == stat)
+			return nfs_errtbl[i].errno;
+	}
+	if (stat <= 10000 || stat > 10100) {
+		/* The server is looney tunes. */
+		return -EREMOTEIO;
+	}
+	/* If we cannot translate the error, the recovery routines should
+	 * handle it.
+	 * Note: remaining NFSv4 error codes have values > 10000, so should
+	 * not conflict with native Linux error codes.
+	 */
+	return -stat;
+}
+
+#ifdef CONFIG_NFS_V4_2
+#include "nfs42xdr.c"
+#endif /* CONFIG_NFS_V4_2 */
+
+#define PROC(proc, argtype, restype)				\
+[NFSPROC4_CLNT_##proc] = {					\
+	.p_proc   = NFSPROC4_COMPOUND,				\
+	.p_encode = nfs4_xdr_##argtype,				\
+	.p_decode = nfs4_xdr_##restype,				\
+	.p_arglen = NFS4_##argtype##_sz,			\
+	.p_replen = NFS4_##restype##_sz,			\
+	.p_statidx = NFSPROC4_CLNT_##proc,			\
+	.p_name   = #proc,					\
+}
+
+#define STUB(proc)		\
+[NFSPROC4_CLNT_##proc] = {	\
+	.p_name = #proc,	\
+}
+
+#if defined(CONFIG_NFS_V4_1)
+#define PROC41(proc, argtype, restype)				\
+	PROC(proc, argtype, restype)
+#else
+#define PROC41(proc, argtype, restype)				\
+	STUB(proc)
+#endif
+
+#if defined(CONFIG_NFS_V4_2)
+#define PROC42(proc, argtype, restype)				\
+	PROC(proc, argtype, restype)
+#else
+#define PROC42(proc, argtype, restype)				\
+	STUB(proc)
+#endif
+
+const struct rpc_procinfo nfs4_procedures[] = {
+	PROC(READ,		enc_read,		dec_read),
+	PROC(WRITE,		enc_write,		dec_write),
+	PROC(COMMIT,		enc_commit,		dec_commit),
+	PROC(OPEN,		enc_open,		dec_open),
+	PROC(OPEN_CONFIRM,	enc_open_confirm,	dec_open_confirm),
+	PROC(OPEN_NOATTR,	enc_open_noattr,	dec_open_noattr),
+	PROC(OPEN_DOWNGRADE,	enc_open_downgrade,	dec_open_downgrade),
+	PROC(CLOSE,		enc_close,		dec_close),
+	PROC(SETATTR,		enc_setattr,		dec_setattr),
+	PROC(FSINFO,		enc_fsinfo,		dec_fsinfo),
+	PROC(RENEW,		enc_renew,		dec_renew),
+	PROC(SETCLIENTID,	enc_setclientid,	dec_setclientid),
+	PROC(SETCLIENTID_CONFIRM, enc_setclientid_confirm, dec_setclientid_confirm),
+	PROC(LOCK,		enc_lock,		dec_lock),
+	PROC(LOCKT,		enc_lockt,		dec_lockt),
+	PROC(LOCKU,		enc_locku,		dec_locku),
+	PROC(ACCESS,		enc_access,		dec_access),
+	PROC(GETATTR,		enc_getattr,		dec_getattr),
+	PROC(LOOKUP,		enc_lookup,		dec_lookup),
+	PROC(LOOKUP_ROOT,	enc_lookup_root,	dec_lookup_root),
+	PROC(REMOVE,		enc_remove,		dec_remove),
+	PROC(RENAME,		enc_rename,		dec_rename),
+	PROC(LINK,		enc_link,		dec_link),
+	PROC(SYMLINK,		enc_symlink,		dec_symlink),
+	PROC(CREATE,		enc_create,		dec_create),
+	PROC(PATHCONF,		enc_pathconf,		dec_pathconf),
+	PROC(STATFS,		enc_statfs,		dec_statfs),
+	PROC(READLINK,		enc_readlink,		dec_readlink),
+	PROC(READDIR,		enc_readdir,		dec_readdir),
+	PROC(SERVER_CAPS,	enc_server_caps,	dec_server_caps),
+	PROC(DELEGRETURN,	enc_delegreturn,	dec_delegreturn),
+	PROC(GETACL,		enc_getacl,		dec_getacl),
+	PROC(SETACL,		enc_setacl,		dec_setacl),
+	PROC(FS_LOCATIONS,	enc_fs_locations,	dec_fs_locations),
+	PROC(RELEASE_LOCKOWNER,	enc_release_lockowner,	dec_release_lockowner),
+	PROC(SECINFO,		enc_secinfo,		dec_secinfo),
+	PROC(FSID_PRESENT,	enc_fsid_present,	dec_fsid_present),
+	PROC41(EXCHANGE_ID,	enc_exchange_id,	dec_exchange_id),
+	PROC41(CREATE_SESSION,	enc_create_session,	dec_create_session),
+	PROC41(DESTROY_SESSION,	enc_destroy_session,	dec_destroy_session),
+	PROC41(SEQUENCE,	enc_sequence,		dec_sequence),
+	PROC(GET_LEASE_TIME,	enc_get_lease_time,	dec_get_lease_time),
+	PROC41(RECLAIM_COMPLETE,enc_reclaim_complete,	dec_reclaim_complete),
+	PROC41(GETDEVICEINFO,	enc_getdeviceinfo,	dec_getdeviceinfo),
+	PROC41(LAYOUTGET,	enc_layoutget,		dec_layoutget),
+	PROC41(LAYOUTCOMMIT,	enc_layoutcommit,	dec_layoutcommit),
+	PROC41(LAYOUTRETURN,	enc_layoutreturn,	dec_layoutreturn),
+	PROC41(SECINFO_NO_NAME,	enc_secinfo_no_name,	dec_secinfo_no_name),
+	PROC41(TEST_STATEID,	enc_test_stateid,	dec_test_stateid),
+	PROC41(FREE_STATEID,	enc_free_stateid,	dec_free_stateid),
+	STUB(GETDEVICELIST),
+	PROC41(BIND_CONN_TO_SESSION,
+			enc_bind_conn_to_session, dec_bind_conn_to_session),
+	PROC41(DESTROY_CLIENTID,enc_destroy_clientid,	dec_destroy_clientid),
+	PROC42(SEEK,		enc_seek,		dec_seek),
+	PROC42(ALLOCATE,	enc_allocate,		dec_allocate),
+	PROC42(DEALLOCATE,	enc_deallocate,		dec_deallocate),
+	PROC42(LAYOUTSTATS,	enc_layoutstats,	dec_layoutstats),
+	PROC42(CLONE,		enc_clone,		dec_clone),
+	PROC42(COPY,		enc_copy,		dec_copy),
+	PROC42(OFFLOAD_CANCEL,	enc_offload_cancel,	dec_offload_cancel),
+	PROC42(COPY_NOTIFY,	enc_copy_notify,	dec_copy_notify),
+	PROC(LOOKUPP,		enc_lookupp,		dec_lookupp),
+	PROC42(LAYOUTERROR,	enc_layouterror,	dec_layouterror),
+	PROC42(GETXATTR,	enc_getxattr,		dec_getxattr),
+	PROC42(SETXATTR,	enc_setxattr,		dec_setxattr),
+	PROC42(LISTXATTRS,	enc_listxattrs,		dec_listxattrs),
+	PROC42(REMOVEXATTR,	enc_removexattr,	dec_removexattr),
+	PROC42(READ_PLUS,	enc_read_plus,		dec_read_plus),
+};
+
+static unsigned int nfs_version4_counts[ARRAY_SIZE(nfs4_procedures)];
+const struct rpc_version nfs_version4 = {
+	.number			= 4,
+	.nrprocs		= ARRAY_SIZE(nfs4_procedures),
+	.procs			= nfs4_procedures,
+	.counts			= nfs_version4_counts,
+};
+
+/*
+ * Local variables:
+ *  c-basic-offset: 8
+ * End:
+ */
diff --git a/fs/nfs/nfsroot.c b/fs/nfs/nfsroot.c
new file mode 100644
index 000000000..fa1483088
--- /dev/null
+++ b/fs/nfs/nfsroot.c
@@ -0,0 +1,316 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  Copyright (C) 1995, 1996  Gero Kuhlmann <gero@gkminix.han.de>
+ *
+ *  Allow an NFS filesystem to be mounted as root. The way this works is:
+ *     (1) Use the IP autoconfig mechanism to set local IP addresses and routes.
+ *     (2) Construct the device string and the options string using DHCP
+ *         option 17 and/or kernel command line options.
+ *     (3) When mount_root() sets up the root file system, pass these strings
+ *         to the NFS client's regular mount interface via sys_mount().
+ *
+ *
+ *	Changes:
+ *
+ *	Alan Cox	:	Removed get_address name clash with FPU.
+ *	Alan Cox	:	Reformatted a bit.
+ *	Gero Kuhlmann	:	Code cleanup
+ *	Michael Rausch  :	Fixed recognition of an incoming RARP answer.
+ *	Martin Mares	: (2.0)	Auto-configuration via BOOTP supported.
+ *	Martin Mares	:	Manual selection of interface & BOOTP/RARP.
+ *	Martin Mares	:	Using network routes instead of host routes,
+ *				allowing the default configuration to be used
+ *				for normal operation of the host.
+ *	Martin Mares	:	Randomized timer with exponential backoff
+ *				installed to minimize network congestion.
+ *	Martin Mares	:	Code cleanup.
+ *	Martin Mares	: (2.1)	BOOTP and RARP made configuration options.
+ *	Martin Mares	:	Server hostname generation fixed.
+ *	Gerd Knorr	:	Fixed wired inode handling
+ *	Martin Mares	: (2.2)	"0.0.0.0" addresses from command line ignored.
+ *	Martin Mares	:	RARP replies not tested for server address.
+ *	Gero Kuhlmann	: (2.3) Some bug fixes and code cleanup again (please
+ *				send me your new patches _before_ bothering
+ *				Linus so that I don' always have to cleanup
+ *				_afterwards_ - thanks)
+ *	Gero Kuhlmann	:	Last changes of Martin Mares undone.
+ *	Gero Kuhlmann	: 	RARP replies are tested for specified server
+ *				again. However, it's now possible to have
+ *				different RARP and NFS servers.
+ *	Gero Kuhlmann	:	"0.0.0.0" addresses from command line are
+ *				now mapped to INADDR_NONE.
+ *	Gero Kuhlmann	:	Fixed a bug which prevented BOOTP path name
+ *				from being used (thanks to Leo Spiekman)
+ *	Andy Walker	:	Allow to specify the NFS server in nfs_root
+ *				without giving a path name
+ *	Swen Thümmler	:	Allow to specify the NFS options in nfs_root
+ *				without giving a path name. Fix BOOTP request
+ *				for domainname (domainname is NIS domain, not
+ *				DNS domain!). Skip dummy devices for BOOTP.
+ *	Jacek Zapala	:	Fixed a bug which prevented server-ip address
+ *				from nfsroot parameter from being used.
+ *	Olaf Kirch	:	Adapted to new NFS code.
+ *	Jakub Jelinek	:	Free used code segment.
+ *	Marko Kohtala	:	Fixed some bugs.
+ *	Martin Mares	:	Debug message cleanup
+ *	Martin Mares	:	Changed to use the new generic IP layer autoconfig
+ *				code. BOOTP and RARP moved there.
+ *	Martin Mares	:	Default path now contains host name instead of
+ *				host IP address (but host name defaults to IP
+ *				address anyway).
+ *	Martin Mares	:	Use root_server_addr appropriately during setup.
+ *	Martin Mares	:	Rewrote parameter parsing, now hopefully giving
+ *				correct overriding.
+ *	Trond Myklebust :	Add in preliminary support for NFSv3 and TCP.
+ *				Fix bug in root_nfs_addr(). nfs_data.namlen
+ *				is NOT for the length of the hostname.
+ *	Hua Qin		:	Support for mounting root file system via
+ *				NFS over TCP.
+ *	Fabian Frederick:	Option parser rebuilt (using parser lib)
+ *	Chuck Lever	:	Use super.c's text-based mount option parsing
+ *	Chuck Lever	:	Add "nfsrootdebug".
+ */
+
+#include <linux/types.h>
+#include <linux/string.h>
+#include <linux/init.h>
+#include <linux/nfs.h>
+#include <linux/nfs_fs.h>
+#include <linux/utsname.h>
+#include <linux/root_dev.h>
+#include <net/ipconfig.h>
+
+#include "internal.h"
+
+#define NFSDBG_FACILITY NFSDBG_ROOT
+
+/* Default path we try to mount. "%s" gets replaced by our IP address */
+#define NFS_ROOT		"/tftpboot/%s"
+
+/* Default NFSROOT mount options. */
+#if defined(CONFIG_NFS_V2)
+#define NFS_DEF_OPTIONS		"vers=2,tcp,rsize=4096,wsize=4096"
+#elif defined(CONFIG_NFS_V3)
+#define NFS_DEF_OPTIONS		"vers=3,tcp,rsize=4096,wsize=4096"
+#else
+#define NFS_DEF_OPTIONS		"vers=4,tcp,rsize=4096,wsize=4096"
+#endif
+
+/* Parameters passed from the kernel command line */
+static char nfs_root_parms[NFS_MAXPATHLEN + 1] __initdata = "";
+
+/* Text-based mount options passed to super.c */
+static char nfs_root_options[256] __initdata = NFS_DEF_OPTIONS;
+
+/* Address of NFS server */
+static __be32 servaddr __initdata = htonl(INADDR_NONE);
+
+/* Name of directory to mount */
+static char nfs_export_path[NFS_MAXPATHLEN + 1] __initdata = "";
+
+/* server:export path string passed to super.c */
+static char nfs_root_device[NFS_MAXPATHLEN + 1] __initdata = "";
+
+#ifdef NFS_DEBUG
+/*
+ * When the "nfsrootdebug" kernel command line option is specified,
+ * enable debugging messages for NFSROOT.
+ */
+static int __init nfs_root_debug(char *__unused)
+{
+	nfs_debug |= NFSDBG_ROOT | NFSDBG_MOUNT;
+	return 1;
+}
+
+__setup("nfsrootdebug", nfs_root_debug);
+#endif
+
+/*
+ *  Parse NFS server and directory information passed on the kernel
+ *  command line.
+ *
+ *  nfsroot=[<server-ip>:]<root-dir>[,<nfs-options>]
+ *
+ *  If there is a "%s" token in the <root-dir> string, it is replaced
+ *  by the ASCII-representation of the client's IP address.
+ */
+static int __init nfs_root_setup(char *line)
+{
+	ROOT_DEV = Root_NFS;
+
+	if (line[0] == '/' || line[0] == ',' || (line[0] >= '0' && line[0] <= '9')) {
+		strlcpy(nfs_root_parms, line, sizeof(nfs_root_parms));
+	} else {
+		size_t n = strlen(line) + sizeof(NFS_ROOT) - 1;
+		if (n >= sizeof(nfs_root_parms))
+			line[sizeof(nfs_root_parms) - sizeof(NFS_ROOT) - 2] = '\0';
+		sprintf(nfs_root_parms, NFS_ROOT, line);
+	}
+
+	/*
+	 * Extract the IP address of the NFS server containing our
+	 * root file system, if one was specified.
+	 *
+	 * Note: root_nfs_parse_addr() removes the server-ip from
+	 *	 nfs_root_parms, if it exists.
+	 */
+	root_server_addr = root_nfs_parse_addr(nfs_root_parms);
+
+	return 1;
+}
+
+__setup("nfsroot=", nfs_root_setup);
+
+static int __init root_nfs_copy(char *dest, const char *src,
+				     const size_t destlen)
+{
+	if (strlcpy(dest, src, destlen) > destlen)
+		return -1;
+	return 0;
+}
+
+static int __init root_nfs_cat(char *dest, const char *src,
+			       const size_t destlen)
+{
+	size_t len = strlen(dest);
+
+	if (len && dest[len - 1] != ',')
+		if (strlcat(dest, ",", destlen) > destlen)
+			return -1;
+
+	if (strlcat(dest, src, destlen) > destlen)
+		return -1;
+	return 0;
+}
+
+/*
+ * Parse out root export path and mount options from
+ * passed-in string @incoming.
+ *
+ * Copy the export path into @exppath.
+ */
+static int __init root_nfs_parse_options(char *incoming, char *exppath,
+					 const size_t exppathlen)
+{
+	char *p;
+
+	/*
+	 * Set the NFS remote path
+	 */
+	p = strsep(&incoming, ",");
+	if (*p != '\0' && strcmp(p, "default") != 0)
+		if (root_nfs_copy(exppath, p, exppathlen))
+			return -1;
+
+	/*
+	 * @incoming now points to the rest of the string; if it
+	 * contains something, append it to our root options buffer
+	 */
+	if (incoming != NULL && *incoming != '\0')
+		if (root_nfs_cat(nfs_root_options, incoming,
+						sizeof(nfs_root_options)))
+			return -1;
+	return 0;
+}
+
+/*
+ *  Decode the export directory path name and NFS options from
+ *  the kernel command line.  This has to be done late in order to
+ *  use a dynamically acquired client IP address for the remote
+ *  root directory path.
+ *
+ *  Returns zero if successful; otherwise -1 is returned.
+ */
+static int __init root_nfs_data(char *cmdline)
+{
+	char mand_options[sizeof("nolock,addr=") + INET_ADDRSTRLEN + 1];
+	int len, retval = -1;
+	char *tmp = NULL;
+	const size_t tmplen = sizeof(nfs_export_path);
+
+	tmp = kzalloc(tmplen, GFP_KERNEL);
+	if (tmp == NULL)
+		goto out_nomem;
+	strcpy(tmp, NFS_ROOT);
+
+	if (root_server_path[0] != '\0') {
+		dprintk("Root-NFS: DHCPv4 option 17: %s\n",
+			root_server_path);
+		if (root_nfs_parse_options(root_server_path, tmp, tmplen))
+			goto out_optionstoolong;
+	}
+
+	if (cmdline[0] != '\0') {
+		dprintk("Root-NFS: nfsroot=%s\n", cmdline);
+		if (root_nfs_parse_options(cmdline, tmp, tmplen))
+			goto out_optionstoolong;
+	}
+
+	/*
+	 * Append mandatory options for nfsroot so they override
+	 * what has come before
+	 */
+	snprintf(mand_options, sizeof(mand_options), "nolock,addr=%pI4",
+			&servaddr);
+	if (root_nfs_cat(nfs_root_options, mand_options,
+						sizeof(nfs_root_options)))
+		goto out_optionstoolong;
+
+	/*
+	 * Set up nfs_root_device.  For NFS mounts, this looks like
+	 *
+	 *	server:/path
+	 *
+	 * At this point, utsname()->nodename contains our local
+	 * IP address or hostname, set by ipconfig.  If "%s" exists
+	 * in tmp, substitute the nodename, then shovel the whole
+	 * mess into nfs_root_device.
+	 */
+	len = snprintf(nfs_export_path, sizeof(nfs_export_path),
+				tmp, utsname()->nodename);
+	if (len >= (int)sizeof(nfs_export_path))
+		goto out_devnametoolong;
+	len = snprintf(nfs_root_device, sizeof(nfs_root_device),
+				"%pI4:%s", &servaddr, nfs_export_path);
+	if (len >= (int)sizeof(nfs_root_device))
+		goto out_devnametoolong;
+
+	retval = 0;
+
+out:
+	kfree(tmp);
+	return retval;
+out_nomem:
+	printk(KERN_ERR "Root-NFS: could not allocate memory\n");
+	goto out;
+out_optionstoolong:
+	printk(KERN_ERR "Root-NFS: mount options string too long\n");
+	goto out;
+out_devnametoolong:
+	printk(KERN_ERR "Root-NFS: root device name too long.\n");
+	goto out;
+}
+
+/**
+ * nfs_root_data - Return prepared 'data' for NFSROOT mount
+ * @root_device: OUT: address of string containing NFSROOT device
+ * @root_data: OUT: address of string containing NFSROOT mount options
+ *
+ * Returns zero and sets @root_device and @root_data if successful,
+ * otherwise -1 is returned.
+ */
+int __init nfs_root_data(char **root_device, char **root_data)
+{
+	servaddr = root_server_addr;
+	if (servaddr == htonl(INADDR_NONE)) {
+		printk(KERN_ERR "Root-NFS: no NFS server address\n");
+		return -1;
+	}
+
+	if (root_nfs_data(nfs_root_parms) < 0)
+		return -1;
+
+	*root_device = nfs_root_device;
+	*root_data = nfs_root_options;
+	return 0;
+}
diff --git a/fs/nfs/nfstrace.c b/fs/nfs/nfstrace.c
new file mode 100644
index 000000000..a90b36350
--- /dev/null
+++ b/fs/nfs/nfstrace.c
@@ -0,0 +1,14 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2013 Trond Myklebust <Trond.Myklebust@netapp.com>
+ */
+#include <linux/nfs_fs.h>
+#include <linux/namei.h>
+#include "internal.h"
+
+#define CREATE_TRACE_POINTS
+#include "nfstrace.h"
+
+EXPORT_TRACEPOINT_SYMBOL_GPL(nfs_fsync_enter);
+EXPORT_TRACEPOINT_SYMBOL_GPL(nfs_fsync_exit);
+EXPORT_TRACEPOINT_SYMBOL_GPL(nfs_xdr_status);
diff --git a/fs/nfs/nfstrace.h b/fs/nfs/nfstrace.h
new file mode 100644
index 000000000..5a59dcdce
--- /dev/null
+++ b/fs/nfs/nfstrace.h
@@ -0,0 +1,1444 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2013 Trond Myklebust <Trond.Myklebust@netapp.com>
+ */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM nfs
+
+#if !defined(_TRACE_NFS_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_NFS_H
+
+#include <linux/tracepoint.h>
+#include <linux/iversion.h>
+
+TRACE_DEFINE_ENUM(DT_UNKNOWN);
+TRACE_DEFINE_ENUM(DT_FIFO);
+TRACE_DEFINE_ENUM(DT_CHR);
+TRACE_DEFINE_ENUM(DT_DIR);
+TRACE_DEFINE_ENUM(DT_BLK);
+TRACE_DEFINE_ENUM(DT_REG);
+TRACE_DEFINE_ENUM(DT_LNK);
+TRACE_DEFINE_ENUM(DT_SOCK);
+TRACE_DEFINE_ENUM(DT_WHT);
+
+#define nfs_show_file_type(ftype) \
+	__print_symbolic(ftype, \
+			{ DT_UNKNOWN, "UNKNOWN" }, \
+			{ DT_FIFO, "FIFO" }, \
+			{ DT_CHR, "CHR" }, \
+			{ DT_DIR, "DIR" }, \
+			{ DT_BLK, "BLK" }, \
+			{ DT_REG, "REG" }, \
+			{ DT_LNK, "LNK" }, \
+			{ DT_SOCK, "SOCK" }, \
+			{ DT_WHT, "WHT" })
+
+TRACE_DEFINE_ENUM(NFS_INO_INVALID_DATA);
+TRACE_DEFINE_ENUM(NFS_INO_INVALID_ATIME);
+TRACE_DEFINE_ENUM(NFS_INO_INVALID_ACCESS);
+TRACE_DEFINE_ENUM(NFS_INO_INVALID_ACL);
+TRACE_DEFINE_ENUM(NFS_INO_REVAL_PAGECACHE);
+TRACE_DEFINE_ENUM(NFS_INO_REVAL_FORCED);
+TRACE_DEFINE_ENUM(NFS_INO_INVALID_LABEL);
+TRACE_DEFINE_ENUM(NFS_INO_INVALID_CHANGE);
+TRACE_DEFINE_ENUM(NFS_INO_INVALID_CTIME);
+TRACE_DEFINE_ENUM(NFS_INO_INVALID_MTIME);
+TRACE_DEFINE_ENUM(NFS_INO_INVALID_SIZE);
+TRACE_DEFINE_ENUM(NFS_INO_INVALID_OTHER);
+
+#define nfs_show_cache_validity(v) \
+	__print_flags(v, "|", \
+			{ NFS_INO_INVALID_DATA, "INVALID_DATA" }, \
+			{ NFS_INO_INVALID_ATIME, "INVALID_ATIME" }, \
+			{ NFS_INO_INVALID_ACCESS, "INVALID_ACCESS" }, \
+			{ NFS_INO_INVALID_ACL, "INVALID_ACL" }, \
+			{ NFS_INO_REVAL_PAGECACHE, "REVAL_PAGECACHE" }, \
+			{ NFS_INO_REVAL_FORCED, "REVAL_FORCED" }, \
+			{ NFS_INO_INVALID_LABEL, "INVALID_LABEL" }, \
+			{ NFS_INO_INVALID_CHANGE, "INVALID_CHANGE" }, \
+			{ NFS_INO_INVALID_CTIME, "INVALID_CTIME" }, \
+			{ NFS_INO_INVALID_MTIME, "INVALID_MTIME" }, \
+			{ NFS_INO_INVALID_SIZE, "INVALID_SIZE" }, \
+			{ NFS_INO_INVALID_OTHER, "INVALID_OTHER" }, \
+			{ NFS_INO_INVALID_XATTR, "INVALID_XATTR" })
+
+TRACE_DEFINE_ENUM(NFS_INO_ADVISE_RDPLUS);
+TRACE_DEFINE_ENUM(NFS_INO_STALE);
+TRACE_DEFINE_ENUM(NFS_INO_ACL_LRU_SET);
+TRACE_DEFINE_ENUM(NFS_INO_INVALIDATING);
+TRACE_DEFINE_ENUM(NFS_INO_FSCACHE);
+TRACE_DEFINE_ENUM(NFS_INO_FSCACHE_LOCK);
+TRACE_DEFINE_ENUM(NFS_INO_LAYOUTCOMMIT);
+TRACE_DEFINE_ENUM(NFS_INO_LAYOUTCOMMITTING);
+TRACE_DEFINE_ENUM(NFS_INO_LAYOUTSTATS);
+TRACE_DEFINE_ENUM(NFS_INO_ODIRECT);
+
+#define nfs_show_nfsi_flags(v) \
+	__print_flags(v, "|", \
+			{ BIT(NFS_INO_ADVISE_RDPLUS), "ADVISE_RDPLUS" }, \
+			{ BIT(NFS_INO_STALE), "STALE" }, \
+			{ BIT(NFS_INO_ACL_LRU_SET), "ACL_LRU_SET" }, \
+			{ BIT(NFS_INO_INVALIDATING), "INVALIDATING" }, \
+			{ BIT(NFS_INO_FSCACHE), "FSCACHE" }, \
+			{ BIT(NFS_INO_FSCACHE_LOCK), "FSCACHE_LOCK" }, \
+			{ BIT(NFS_INO_LAYOUTCOMMIT), "NEED_LAYOUTCOMMIT" }, \
+			{ BIT(NFS_INO_LAYOUTCOMMITTING), "LAYOUTCOMMIT" }, \
+			{ BIT(NFS_INO_LAYOUTSTATS), "LAYOUTSTATS" }, \
+			{ BIT(NFS_INO_ODIRECT), "ODIRECT" })
+
+DECLARE_EVENT_CLASS(nfs_inode_event,
+		TP_PROTO(
+			const struct inode *inode
+		),
+
+		TP_ARGS(inode),
+
+		TP_STRUCT__entry(
+			__field(dev_t, dev)
+			__field(u32, fhandle)
+			__field(u64, fileid)
+			__field(u64, version)
+		),
+
+		TP_fast_assign(
+			const struct nfs_inode *nfsi = NFS_I(inode);
+			__entry->dev = inode->i_sb->s_dev;
+			__entry->fileid = nfsi->fileid;
+			__entry->fhandle = nfs_fhandle_hash(&nfsi->fh);
+			__entry->version = inode_peek_iversion_raw(inode);
+		),
+
+		TP_printk(
+			"fileid=%02x:%02x:%llu fhandle=0x%08x version=%llu ",
+			MAJOR(__entry->dev), MINOR(__entry->dev),
+			(unsigned long long)__entry->fileid,
+			__entry->fhandle,
+			(unsigned long long)__entry->version
+		)
+);
+
+DECLARE_EVENT_CLASS(nfs_inode_event_done,
+		TP_PROTO(
+			const struct inode *inode,
+			int error
+		),
+
+		TP_ARGS(inode, error),
+
+		TP_STRUCT__entry(
+			__field(unsigned long, error)
+			__field(dev_t, dev)
+			__field(u32, fhandle)
+			__field(unsigned char, type)
+			__field(u64, fileid)
+			__field(u64, version)
+			__field(loff_t, size)
+			__field(unsigned long, nfsi_flags)
+			__field(unsigned long, cache_validity)
+		),
+
+		TP_fast_assign(
+			const struct nfs_inode *nfsi = NFS_I(inode);
+			__entry->error = error < 0 ? -error : 0;
+			__entry->dev = inode->i_sb->s_dev;
+			__entry->fileid = nfsi->fileid;
+			__entry->fhandle = nfs_fhandle_hash(&nfsi->fh);
+			__entry->type = nfs_umode_to_dtype(inode->i_mode);
+			__entry->version = inode_peek_iversion_raw(inode);
+			__entry->size = i_size_read(inode);
+			__entry->nfsi_flags = nfsi->flags;
+			__entry->cache_validity = nfsi->cache_validity;
+		),
+
+		TP_printk(
+			"error=%ld (%s) fileid=%02x:%02x:%llu fhandle=0x%08x "
+			"type=%u (%s) version=%llu size=%lld "
+			"cache_validity=0x%lx (%s) nfs_flags=0x%lx (%s)",
+			-__entry->error, nfs_show_status(__entry->error),
+			MAJOR(__entry->dev), MINOR(__entry->dev),
+			(unsigned long long)__entry->fileid,
+			__entry->fhandle,
+			__entry->type,
+			nfs_show_file_type(__entry->type),
+			(unsigned long long)__entry->version,
+			(long long)__entry->size,
+			__entry->cache_validity,
+			nfs_show_cache_validity(__entry->cache_validity),
+			__entry->nfsi_flags,
+			nfs_show_nfsi_flags(__entry->nfsi_flags)
+		)
+);
+
+#define DEFINE_NFS_INODE_EVENT(name) \
+	DEFINE_EVENT(nfs_inode_event, name, \
+			TP_PROTO( \
+				const struct inode *inode \
+			), \
+			TP_ARGS(inode))
+#define DEFINE_NFS_INODE_EVENT_DONE(name) \
+	DEFINE_EVENT(nfs_inode_event_done, name, \
+			TP_PROTO( \
+				const struct inode *inode, \
+				int error \
+			), \
+			TP_ARGS(inode, error))
+DEFINE_NFS_INODE_EVENT(nfs_set_inode_stale);
+DEFINE_NFS_INODE_EVENT(nfs_refresh_inode_enter);
+DEFINE_NFS_INODE_EVENT_DONE(nfs_refresh_inode_exit);
+DEFINE_NFS_INODE_EVENT(nfs_revalidate_inode_enter);
+DEFINE_NFS_INODE_EVENT_DONE(nfs_revalidate_inode_exit);
+DEFINE_NFS_INODE_EVENT(nfs_invalidate_mapping_enter);
+DEFINE_NFS_INODE_EVENT_DONE(nfs_invalidate_mapping_exit);
+DEFINE_NFS_INODE_EVENT(nfs_getattr_enter);
+DEFINE_NFS_INODE_EVENT_DONE(nfs_getattr_exit);
+DEFINE_NFS_INODE_EVENT(nfs_setattr_enter);
+DEFINE_NFS_INODE_EVENT_DONE(nfs_setattr_exit);
+DEFINE_NFS_INODE_EVENT(nfs_writeback_page_enter);
+DEFINE_NFS_INODE_EVENT_DONE(nfs_writeback_page_exit);
+DEFINE_NFS_INODE_EVENT(nfs_writeback_inode_enter);
+DEFINE_NFS_INODE_EVENT_DONE(nfs_writeback_inode_exit);
+DEFINE_NFS_INODE_EVENT(nfs_fsync_enter);
+DEFINE_NFS_INODE_EVENT_DONE(nfs_fsync_exit);
+DEFINE_NFS_INODE_EVENT(nfs_access_enter);
+
+TRACE_EVENT(nfs_access_exit,
+		TP_PROTO(
+			const struct inode *inode,
+			unsigned int mask,
+			unsigned int permitted,
+			int error
+		),
+
+		TP_ARGS(inode, mask, permitted, error),
+
+		TP_STRUCT__entry(
+			__field(unsigned long, error)
+			__field(dev_t, dev)
+			__field(u32, fhandle)
+			__field(unsigned char, type)
+			__field(u64, fileid)
+			__field(u64, version)
+			__field(loff_t, size)
+			__field(unsigned long, nfsi_flags)
+			__field(unsigned long, cache_validity)
+			__field(unsigned int, mask)
+			__field(unsigned int, permitted)
+		),
+
+		TP_fast_assign(
+			const struct nfs_inode *nfsi = NFS_I(inode);
+			__entry->error = error < 0 ? -error : 0;
+			__entry->dev = inode->i_sb->s_dev;
+			__entry->fileid = nfsi->fileid;
+			__entry->fhandle = nfs_fhandle_hash(&nfsi->fh);
+			__entry->type = nfs_umode_to_dtype(inode->i_mode);
+			__entry->version = inode_peek_iversion_raw(inode);
+			__entry->size = i_size_read(inode);
+			__entry->nfsi_flags = nfsi->flags;
+			__entry->cache_validity = nfsi->cache_validity;
+			__entry->mask = mask;
+			__entry->permitted = permitted;
+		),
+
+		TP_printk(
+			"error=%ld (%s) fileid=%02x:%02x:%llu fhandle=0x%08x "
+			"type=%u (%s) version=%llu size=%lld "
+			"cache_validity=0x%lx (%s) nfs_flags=0x%lx (%s) "
+			"mask=0x%x permitted=0x%x",
+			-__entry->error, nfs_show_status(__entry->error),
+			MAJOR(__entry->dev), MINOR(__entry->dev),
+			(unsigned long long)__entry->fileid,
+			__entry->fhandle,
+			__entry->type,
+			nfs_show_file_type(__entry->type),
+			(unsigned long long)__entry->version,
+			(long long)__entry->size,
+			__entry->cache_validity,
+			nfs_show_cache_validity(__entry->cache_validity),
+			__entry->nfsi_flags,
+			nfs_show_nfsi_flags(__entry->nfsi_flags),
+			__entry->mask, __entry->permitted
+		)
+);
+
+TRACE_DEFINE_ENUM(LOOKUP_FOLLOW);
+TRACE_DEFINE_ENUM(LOOKUP_DIRECTORY);
+TRACE_DEFINE_ENUM(LOOKUP_AUTOMOUNT);
+TRACE_DEFINE_ENUM(LOOKUP_PARENT);
+TRACE_DEFINE_ENUM(LOOKUP_REVAL);
+TRACE_DEFINE_ENUM(LOOKUP_RCU);
+TRACE_DEFINE_ENUM(LOOKUP_OPEN);
+TRACE_DEFINE_ENUM(LOOKUP_CREATE);
+TRACE_DEFINE_ENUM(LOOKUP_EXCL);
+TRACE_DEFINE_ENUM(LOOKUP_RENAME_TARGET);
+TRACE_DEFINE_ENUM(LOOKUP_JUMPED);
+TRACE_DEFINE_ENUM(LOOKUP_ROOT);
+TRACE_DEFINE_ENUM(LOOKUP_EMPTY);
+TRACE_DEFINE_ENUM(LOOKUP_DOWN);
+
+#define show_lookup_flags(flags) \
+	__print_flags(flags, "|", \
+			{ LOOKUP_FOLLOW, "FOLLOW" }, \
+			{ LOOKUP_DIRECTORY, "DIRECTORY" }, \
+			{ LOOKUP_AUTOMOUNT, "AUTOMOUNT" }, \
+			{ LOOKUP_PARENT, "PARENT" }, \
+			{ LOOKUP_REVAL, "REVAL" }, \
+			{ LOOKUP_RCU, "RCU" }, \
+			{ LOOKUP_OPEN, "OPEN" }, \
+			{ LOOKUP_CREATE, "CREATE" }, \
+			{ LOOKUP_EXCL, "EXCL" }, \
+			{ LOOKUP_RENAME_TARGET, "RENAME_TARGET" }, \
+			{ LOOKUP_JUMPED, "JUMPED" }, \
+			{ LOOKUP_ROOT, "ROOT" }, \
+			{ LOOKUP_EMPTY, "EMPTY" }, \
+			{ LOOKUP_DOWN, "DOWN" })
+
+DECLARE_EVENT_CLASS(nfs_lookup_event,
+		TP_PROTO(
+			const struct inode *dir,
+			const struct dentry *dentry,
+			unsigned int flags
+		),
+
+		TP_ARGS(dir, dentry, flags),
+
+		TP_STRUCT__entry(
+			__field(unsigned long, flags)
+			__field(dev_t, dev)
+			__field(u64, dir)
+			__string(name, dentry->d_name.name)
+		),
+
+		TP_fast_assign(
+			__entry->dev = dir->i_sb->s_dev;
+			__entry->dir = NFS_FILEID(dir);
+			__entry->flags = flags;
+			__assign_str(name, dentry->d_name.name);
+		),
+
+		TP_printk(
+			"flags=0x%lx (%s) name=%02x:%02x:%llu/%s",
+			__entry->flags,
+			show_lookup_flags(__entry->flags),
+			MAJOR(__entry->dev), MINOR(__entry->dev),
+			(unsigned long long)__entry->dir,
+			__get_str(name)
+		)
+);
+
+#define DEFINE_NFS_LOOKUP_EVENT(name) \
+	DEFINE_EVENT(nfs_lookup_event, name, \
+			TP_PROTO( \
+				const struct inode *dir, \
+				const struct dentry *dentry, \
+				unsigned int flags \
+			), \
+			TP_ARGS(dir, dentry, flags))
+
+DECLARE_EVENT_CLASS(nfs_lookup_event_done,
+		TP_PROTO(
+			const struct inode *dir,
+			const struct dentry *dentry,
+			unsigned int flags,
+			int error
+		),
+
+		TP_ARGS(dir, dentry, flags, error),
+
+		TP_STRUCT__entry(
+			__field(unsigned long, error)
+			__field(unsigned long, flags)
+			__field(dev_t, dev)
+			__field(u64, dir)
+			__string(name, dentry->d_name.name)
+		),
+
+		TP_fast_assign(
+			__entry->dev = dir->i_sb->s_dev;
+			__entry->dir = NFS_FILEID(dir);
+			__entry->error = error < 0 ? -error : 0;
+			__entry->flags = flags;
+			__assign_str(name, dentry->d_name.name);
+		),
+
+		TP_printk(
+			"error=%ld (%s) flags=0x%lx (%s) name=%02x:%02x:%llu/%s",
+			-__entry->error, nfs_show_status(__entry->error),
+			__entry->flags,
+			show_lookup_flags(__entry->flags),
+			MAJOR(__entry->dev), MINOR(__entry->dev),
+			(unsigned long long)__entry->dir,
+			__get_str(name)
+		)
+);
+
+#define DEFINE_NFS_LOOKUP_EVENT_DONE(name) \
+	DEFINE_EVENT(nfs_lookup_event_done, name, \
+			TP_PROTO( \
+				const struct inode *dir, \
+				const struct dentry *dentry, \
+				unsigned int flags, \
+				int error \
+			), \
+			TP_ARGS(dir, dentry, flags, error))
+
+DEFINE_NFS_LOOKUP_EVENT(nfs_lookup_enter);
+DEFINE_NFS_LOOKUP_EVENT_DONE(nfs_lookup_exit);
+DEFINE_NFS_LOOKUP_EVENT(nfs_lookup_revalidate_enter);
+DEFINE_NFS_LOOKUP_EVENT_DONE(nfs_lookup_revalidate_exit);
+
+TRACE_DEFINE_ENUM(O_WRONLY);
+TRACE_DEFINE_ENUM(O_RDWR);
+TRACE_DEFINE_ENUM(O_CREAT);
+TRACE_DEFINE_ENUM(O_EXCL);
+TRACE_DEFINE_ENUM(O_NOCTTY);
+TRACE_DEFINE_ENUM(O_TRUNC);
+TRACE_DEFINE_ENUM(O_APPEND);
+TRACE_DEFINE_ENUM(O_NONBLOCK);
+TRACE_DEFINE_ENUM(O_DSYNC);
+TRACE_DEFINE_ENUM(O_DIRECT);
+TRACE_DEFINE_ENUM(O_LARGEFILE);
+TRACE_DEFINE_ENUM(O_DIRECTORY);
+TRACE_DEFINE_ENUM(O_NOFOLLOW);
+TRACE_DEFINE_ENUM(O_NOATIME);
+TRACE_DEFINE_ENUM(O_CLOEXEC);
+
+#define show_open_flags(flags) \
+	__print_flags(flags, "|", \
+		{ O_WRONLY, "O_WRONLY" }, \
+		{ O_RDWR, "O_RDWR" }, \
+		{ O_CREAT, "O_CREAT" }, \
+		{ O_EXCL, "O_EXCL" }, \
+		{ O_NOCTTY, "O_NOCTTY" }, \
+		{ O_TRUNC, "O_TRUNC" }, \
+		{ O_APPEND, "O_APPEND" }, \
+		{ O_NONBLOCK, "O_NONBLOCK" }, \
+		{ O_DSYNC, "O_DSYNC" }, \
+		{ O_DIRECT, "O_DIRECT" }, \
+		{ O_LARGEFILE, "O_LARGEFILE" }, \
+		{ O_DIRECTORY, "O_DIRECTORY" }, \
+		{ O_NOFOLLOW, "O_NOFOLLOW" }, \
+		{ O_NOATIME, "O_NOATIME" }, \
+		{ O_CLOEXEC, "O_CLOEXEC" })
+
+TRACE_DEFINE_ENUM(FMODE_READ);
+TRACE_DEFINE_ENUM(FMODE_WRITE);
+TRACE_DEFINE_ENUM(FMODE_EXEC);
+
+#define show_fmode_flags(mode) \
+	__print_flags(mode, "|", \
+		{ ((__force unsigned long)FMODE_READ), "READ" }, \
+		{ ((__force unsigned long)FMODE_WRITE), "WRITE" }, \
+		{ ((__force unsigned long)FMODE_EXEC), "EXEC" })
+
+TRACE_EVENT(nfs_atomic_open_enter,
+		TP_PROTO(
+			const struct inode *dir,
+			const struct nfs_open_context *ctx,
+			unsigned int flags
+		),
+
+		TP_ARGS(dir, ctx, flags),
+
+		TP_STRUCT__entry(
+			__field(unsigned long, flags)
+			__field(unsigned int, fmode)
+			__field(dev_t, dev)
+			__field(u64, dir)
+			__string(name, ctx->dentry->d_name.name)
+		),
+
+		TP_fast_assign(
+			__entry->dev = dir->i_sb->s_dev;
+			__entry->dir = NFS_FILEID(dir);
+			__entry->flags = flags;
+			__entry->fmode = (__force unsigned int)ctx->mode;
+			__assign_str(name, ctx->dentry->d_name.name);
+		),
+
+		TP_printk(
+			"flags=0x%lx (%s) fmode=%s name=%02x:%02x:%llu/%s",
+			__entry->flags,
+			show_open_flags(__entry->flags),
+			show_fmode_flags(__entry->fmode),
+			MAJOR(__entry->dev), MINOR(__entry->dev),
+			(unsigned long long)__entry->dir,
+			__get_str(name)
+		)
+);
+
+TRACE_EVENT(nfs_atomic_open_exit,
+		TP_PROTO(
+			const struct inode *dir,
+			const struct nfs_open_context *ctx,
+			unsigned int flags,
+			int error
+		),
+
+		TP_ARGS(dir, ctx, flags, error),
+
+		TP_STRUCT__entry(
+			__field(unsigned long, error)
+			__field(unsigned long, flags)
+			__field(unsigned int, fmode)
+			__field(dev_t, dev)
+			__field(u64, dir)
+			__string(name, ctx->dentry->d_name.name)
+		),
+
+		TP_fast_assign(
+			__entry->error = -error;
+			__entry->dev = dir->i_sb->s_dev;
+			__entry->dir = NFS_FILEID(dir);
+			__entry->flags = flags;
+			__entry->fmode = (__force unsigned int)ctx->mode;
+			__assign_str(name, ctx->dentry->d_name.name);
+		),
+
+		TP_printk(
+			"error=%ld (%s) flags=0x%lx (%s) fmode=%s "
+			"name=%02x:%02x:%llu/%s",
+			-__entry->error, nfs_show_status(__entry->error),
+			__entry->flags,
+			show_open_flags(__entry->flags),
+			show_fmode_flags(__entry->fmode),
+			MAJOR(__entry->dev), MINOR(__entry->dev),
+			(unsigned long long)__entry->dir,
+			__get_str(name)
+		)
+);
+
+TRACE_EVENT(nfs_create_enter,
+		TP_PROTO(
+			const struct inode *dir,
+			const struct dentry *dentry,
+			unsigned int flags
+		),
+
+		TP_ARGS(dir, dentry, flags),
+
+		TP_STRUCT__entry(
+			__field(unsigned long, flags)
+			__field(dev_t, dev)
+			__field(u64, dir)
+			__string(name, dentry->d_name.name)
+		),
+
+		TP_fast_assign(
+			__entry->dev = dir->i_sb->s_dev;
+			__entry->dir = NFS_FILEID(dir);
+			__entry->flags = flags;
+			__assign_str(name, dentry->d_name.name);
+		),
+
+		TP_printk(
+			"flags=0x%lx (%s) name=%02x:%02x:%llu/%s",
+			__entry->flags,
+			show_open_flags(__entry->flags),
+			MAJOR(__entry->dev), MINOR(__entry->dev),
+			(unsigned long long)__entry->dir,
+			__get_str(name)
+		)
+);
+
+TRACE_EVENT(nfs_create_exit,
+		TP_PROTO(
+			const struct inode *dir,
+			const struct dentry *dentry,
+			unsigned int flags,
+			int error
+		),
+
+		TP_ARGS(dir, dentry, flags, error),
+
+		TP_STRUCT__entry(
+			__field(unsigned long, error)
+			__field(unsigned long, flags)
+			__field(dev_t, dev)
+			__field(u64, dir)
+			__string(name, dentry->d_name.name)
+		),
+
+		TP_fast_assign(
+			__entry->error = -error;
+			__entry->dev = dir->i_sb->s_dev;
+			__entry->dir = NFS_FILEID(dir);
+			__entry->flags = flags;
+			__assign_str(name, dentry->d_name.name);
+		),
+
+		TP_printk(
+			"error=%ld (%s) flags=0x%lx (%s) name=%02x:%02x:%llu/%s",
+			-__entry->error, nfs_show_status(__entry->error),
+			__entry->flags,
+			show_open_flags(__entry->flags),
+			MAJOR(__entry->dev), MINOR(__entry->dev),
+			(unsigned long long)__entry->dir,
+			__get_str(name)
+		)
+);
+
+DECLARE_EVENT_CLASS(nfs_directory_event,
+		TP_PROTO(
+			const struct inode *dir,
+			const struct dentry *dentry
+		),
+
+		TP_ARGS(dir, dentry),
+
+		TP_STRUCT__entry(
+			__field(dev_t, dev)
+			__field(u64, dir)
+			__string(name, dentry->d_name.name)
+		),
+
+		TP_fast_assign(
+			__entry->dev = dir->i_sb->s_dev;
+			__entry->dir = NFS_FILEID(dir);
+			__assign_str(name, dentry->d_name.name);
+		),
+
+		TP_printk(
+			"name=%02x:%02x:%llu/%s",
+			MAJOR(__entry->dev), MINOR(__entry->dev),
+			(unsigned long long)__entry->dir,
+			__get_str(name)
+		)
+);
+
+#define DEFINE_NFS_DIRECTORY_EVENT(name) \
+	DEFINE_EVENT(nfs_directory_event, name, \
+			TP_PROTO( \
+				const struct inode *dir, \
+				const struct dentry *dentry \
+			), \
+			TP_ARGS(dir, dentry))
+
+DECLARE_EVENT_CLASS(nfs_directory_event_done,
+		TP_PROTO(
+			const struct inode *dir,
+			const struct dentry *dentry,
+			int error
+		),
+
+		TP_ARGS(dir, dentry, error),
+
+		TP_STRUCT__entry(
+			__field(unsigned long, error)
+			__field(dev_t, dev)
+			__field(u64, dir)
+			__string(name, dentry->d_name.name)
+		),
+
+		TP_fast_assign(
+			__entry->dev = dir->i_sb->s_dev;
+			__entry->dir = NFS_FILEID(dir);
+			__entry->error = error < 0 ? -error : 0;
+			__assign_str(name, dentry->d_name.name);
+		),
+
+		TP_printk(
+			"error=%ld (%s) name=%02x:%02x:%llu/%s",
+			-__entry->error, nfs_show_status(__entry->error),
+			MAJOR(__entry->dev), MINOR(__entry->dev),
+			(unsigned long long)__entry->dir,
+			__get_str(name)
+		)
+);
+
+#define DEFINE_NFS_DIRECTORY_EVENT_DONE(name) \
+	DEFINE_EVENT(nfs_directory_event_done, name, \
+			TP_PROTO( \
+				const struct inode *dir, \
+				const struct dentry *dentry, \
+				int error \
+			), \
+			TP_ARGS(dir, dentry, error))
+
+DEFINE_NFS_DIRECTORY_EVENT(nfs_mknod_enter);
+DEFINE_NFS_DIRECTORY_EVENT_DONE(nfs_mknod_exit);
+DEFINE_NFS_DIRECTORY_EVENT(nfs_mkdir_enter);
+DEFINE_NFS_DIRECTORY_EVENT_DONE(nfs_mkdir_exit);
+DEFINE_NFS_DIRECTORY_EVENT(nfs_rmdir_enter);
+DEFINE_NFS_DIRECTORY_EVENT_DONE(nfs_rmdir_exit);
+DEFINE_NFS_DIRECTORY_EVENT(nfs_remove_enter);
+DEFINE_NFS_DIRECTORY_EVENT_DONE(nfs_remove_exit);
+DEFINE_NFS_DIRECTORY_EVENT(nfs_unlink_enter);
+DEFINE_NFS_DIRECTORY_EVENT_DONE(nfs_unlink_exit);
+DEFINE_NFS_DIRECTORY_EVENT(nfs_symlink_enter);
+DEFINE_NFS_DIRECTORY_EVENT_DONE(nfs_symlink_exit);
+
+TRACE_EVENT(nfs_link_enter,
+		TP_PROTO(
+			const struct inode *inode,
+			const struct inode *dir,
+			const struct dentry *dentry
+		),
+
+		TP_ARGS(inode, dir, dentry),
+
+		TP_STRUCT__entry(
+			__field(dev_t, dev)
+			__field(u64, fileid)
+			__field(u64, dir)
+			__string(name, dentry->d_name.name)
+		),
+
+		TP_fast_assign(
+			__entry->dev = inode->i_sb->s_dev;
+			__entry->fileid = NFS_FILEID(inode);
+			__entry->dir = NFS_FILEID(dir);
+			__assign_str(name, dentry->d_name.name);
+		),
+
+		TP_printk(
+			"fileid=%02x:%02x:%llu name=%02x:%02x:%llu/%s",
+			MAJOR(__entry->dev), MINOR(__entry->dev),
+			__entry->fileid,
+			MAJOR(__entry->dev), MINOR(__entry->dev),
+			(unsigned long long)__entry->dir,
+			__get_str(name)
+		)
+);
+
+TRACE_EVENT(nfs_link_exit,
+		TP_PROTO(
+			const struct inode *inode,
+			const struct inode *dir,
+			const struct dentry *dentry,
+			int error
+		),
+
+		TP_ARGS(inode, dir, dentry, error),
+
+		TP_STRUCT__entry(
+			__field(unsigned long, error)
+			__field(dev_t, dev)
+			__field(u64, fileid)
+			__field(u64, dir)
+			__string(name, dentry->d_name.name)
+		),
+
+		TP_fast_assign(
+			__entry->dev = inode->i_sb->s_dev;
+			__entry->fileid = NFS_FILEID(inode);
+			__entry->dir = NFS_FILEID(dir);
+			__entry->error = error < 0 ? -error : 0;
+			__assign_str(name, dentry->d_name.name);
+		),
+
+		TP_printk(
+			"error=%ld (%s) fileid=%02x:%02x:%llu name=%02x:%02x:%llu/%s",
+			-__entry->error, nfs_show_status(__entry->error),
+			MAJOR(__entry->dev), MINOR(__entry->dev),
+			__entry->fileid,
+			MAJOR(__entry->dev), MINOR(__entry->dev),
+			(unsigned long long)__entry->dir,
+			__get_str(name)
+		)
+);
+
+DECLARE_EVENT_CLASS(nfs_rename_event,
+		TP_PROTO(
+			const struct inode *old_dir,
+			const struct dentry *old_dentry,
+			const struct inode *new_dir,
+			const struct dentry *new_dentry
+		),
+
+		TP_ARGS(old_dir, old_dentry, new_dir, new_dentry),
+
+		TP_STRUCT__entry(
+			__field(dev_t, dev)
+			__field(u64, old_dir)
+			__field(u64, new_dir)
+			__string(old_name, old_dentry->d_name.name)
+			__string(new_name, new_dentry->d_name.name)
+		),
+
+		TP_fast_assign(
+			__entry->dev = old_dir->i_sb->s_dev;
+			__entry->old_dir = NFS_FILEID(old_dir);
+			__entry->new_dir = NFS_FILEID(new_dir);
+			__assign_str(old_name, old_dentry->d_name.name);
+			__assign_str(new_name, new_dentry->d_name.name);
+		),
+
+		TP_printk(
+			"old_name=%02x:%02x:%llu/%s new_name=%02x:%02x:%llu/%s",
+			MAJOR(__entry->dev), MINOR(__entry->dev),
+			(unsigned long long)__entry->old_dir,
+			__get_str(old_name),
+			MAJOR(__entry->dev), MINOR(__entry->dev),
+			(unsigned long long)__entry->new_dir,
+			__get_str(new_name)
+		)
+);
+#define DEFINE_NFS_RENAME_EVENT(name) \
+	DEFINE_EVENT(nfs_rename_event, name, \
+			TP_PROTO( \
+				const struct inode *old_dir, \
+				const struct dentry *old_dentry, \
+				const struct inode *new_dir, \
+				const struct dentry *new_dentry \
+			), \
+			TP_ARGS(old_dir, old_dentry, new_dir, new_dentry))
+
+DECLARE_EVENT_CLASS(nfs_rename_event_done,
+		TP_PROTO(
+			const struct inode *old_dir,
+			const struct dentry *old_dentry,
+			const struct inode *new_dir,
+			const struct dentry *new_dentry,
+			int error
+		),
+
+		TP_ARGS(old_dir, old_dentry, new_dir, new_dentry, error),
+
+		TP_STRUCT__entry(
+			__field(dev_t, dev)
+			__field(unsigned long, error)
+			__field(u64, old_dir)
+			__string(old_name, old_dentry->d_name.name)
+			__field(u64, new_dir)
+			__string(new_name, new_dentry->d_name.name)
+		),
+
+		TP_fast_assign(
+			__entry->dev = old_dir->i_sb->s_dev;
+			__entry->error = -error;
+			__entry->old_dir = NFS_FILEID(old_dir);
+			__entry->new_dir = NFS_FILEID(new_dir);
+			__assign_str(old_name, old_dentry->d_name.name);
+			__assign_str(new_name, new_dentry->d_name.name);
+		),
+
+		TP_printk(
+			"error=%ld (%s) old_name=%02x:%02x:%llu/%s "
+			"new_name=%02x:%02x:%llu/%s",
+			-__entry->error, nfs_show_status(__entry->error),
+			MAJOR(__entry->dev), MINOR(__entry->dev),
+			(unsigned long long)__entry->old_dir,
+			__get_str(old_name),
+			MAJOR(__entry->dev), MINOR(__entry->dev),
+			(unsigned long long)__entry->new_dir,
+			__get_str(new_name)
+		)
+);
+#define DEFINE_NFS_RENAME_EVENT_DONE(name) \
+	DEFINE_EVENT(nfs_rename_event_done, name, \
+			TP_PROTO( \
+				const struct inode *old_dir, \
+				const struct dentry *old_dentry, \
+				const struct inode *new_dir, \
+				const struct dentry *new_dentry, \
+				int error \
+			), \
+			TP_ARGS(old_dir, old_dentry, new_dir, \
+				new_dentry, error))
+
+DEFINE_NFS_RENAME_EVENT(nfs_rename_enter);
+DEFINE_NFS_RENAME_EVENT_DONE(nfs_rename_exit);
+
+DEFINE_NFS_RENAME_EVENT_DONE(nfs_sillyrename_rename);
+
+TRACE_EVENT(nfs_sillyrename_unlink,
+		TP_PROTO(
+			const struct nfs_unlinkdata *data,
+			int error
+		),
+
+		TP_ARGS(data, error),
+
+		TP_STRUCT__entry(
+			__field(dev_t, dev)
+			__field(unsigned long, error)
+			__field(u64, dir)
+			__dynamic_array(char, name, data->args.name.len + 1)
+		),
+
+		TP_fast_assign(
+			struct inode *dir = d_inode(data->dentry->d_parent);
+			size_t len = data->args.name.len;
+			__entry->dev = dir->i_sb->s_dev;
+			__entry->dir = NFS_FILEID(dir);
+			__entry->error = -error;
+			memcpy(__get_str(name),
+				data->args.name.name, len);
+			__get_str(name)[len] = 0;
+		),
+
+		TP_printk(
+			"error=%ld (%s) name=%02x:%02x:%llu/%s",
+			-__entry->error, nfs_show_status(__entry->error),
+			MAJOR(__entry->dev), MINOR(__entry->dev),
+			(unsigned long long)__entry->dir,
+			__get_str(name)
+		)
+);
+
+TRACE_EVENT(nfs_initiate_read,
+		TP_PROTO(
+			const struct nfs_pgio_header *hdr
+		),
+
+		TP_ARGS(hdr),
+
+		TP_STRUCT__entry(
+			__field(dev_t, dev)
+			__field(u32, fhandle)
+			__field(u64, fileid)
+			__field(loff_t, offset)
+			__field(u32, count)
+		),
+
+		TP_fast_assign(
+			const struct inode *inode = hdr->inode;
+			const struct nfs_inode *nfsi = NFS_I(inode);
+			const struct nfs_fh *fh = hdr->args.fh ?
+						  hdr->args.fh : &nfsi->fh;
+
+			__entry->offset = hdr->args.offset;
+			__entry->count = hdr->args.count;
+			__entry->dev = inode->i_sb->s_dev;
+			__entry->fileid = nfsi->fileid;
+			__entry->fhandle = nfs_fhandle_hash(fh);
+		),
+
+		TP_printk(
+			"fileid=%02x:%02x:%llu fhandle=0x%08x "
+			"offset=%lld count=%u",
+			MAJOR(__entry->dev), MINOR(__entry->dev),
+			(unsigned long long)__entry->fileid,
+			__entry->fhandle,
+			(long long)__entry->offset, __entry->count
+		)
+);
+
+TRACE_EVENT(nfs_readpage_done,
+		TP_PROTO(
+			const struct rpc_task *task,
+			const struct nfs_pgio_header *hdr
+		),
+
+		TP_ARGS(task, hdr),
+
+		TP_STRUCT__entry(
+			__field(dev_t, dev)
+			__field(u32, fhandle)
+			__field(u64, fileid)
+			__field(loff_t, offset)
+			__field(u32, arg_count)
+			__field(u32, res_count)
+			__field(bool, eof)
+			__field(int, status)
+		),
+
+		TP_fast_assign(
+			const struct inode *inode = hdr->inode;
+			const struct nfs_inode *nfsi = NFS_I(inode);
+			const struct nfs_fh *fh = hdr->args.fh ?
+						  hdr->args.fh : &nfsi->fh;
+
+			__entry->status = task->tk_status;
+			__entry->offset = hdr->args.offset;
+			__entry->arg_count = hdr->args.count;
+			__entry->res_count = hdr->res.count;
+			__entry->eof = hdr->res.eof;
+			__entry->dev = inode->i_sb->s_dev;
+			__entry->fileid = nfsi->fileid;
+			__entry->fhandle = nfs_fhandle_hash(fh);
+		),
+
+		TP_printk(
+			"fileid=%02x:%02x:%llu fhandle=0x%08x "
+			"offset=%lld count=%u res=%u status=%d%s",
+			MAJOR(__entry->dev), MINOR(__entry->dev),
+			(unsigned long long)__entry->fileid,
+			__entry->fhandle,
+			(long long)__entry->offset, __entry->arg_count,
+			__entry->res_count, __entry->status,
+			__entry->eof ? " eof" : ""
+		)
+);
+
+TRACE_EVENT(nfs_readpage_short,
+		TP_PROTO(
+			const struct rpc_task *task,
+			const struct nfs_pgio_header *hdr
+		),
+
+		TP_ARGS(task, hdr),
+
+		TP_STRUCT__entry(
+			__field(dev_t, dev)
+			__field(u32, fhandle)
+			__field(u64, fileid)
+			__field(loff_t, offset)
+			__field(u32, arg_count)
+			__field(u32, res_count)
+			__field(bool, eof)
+			__field(int, status)
+		),
+
+		TP_fast_assign(
+			const struct inode *inode = hdr->inode;
+			const struct nfs_inode *nfsi = NFS_I(inode);
+			const struct nfs_fh *fh = hdr->args.fh ?
+						  hdr->args.fh : &nfsi->fh;
+
+			__entry->status = task->tk_status;
+			__entry->offset = hdr->args.offset;
+			__entry->arg_count = hdr->args.count;
+			__entry->res_count = hdr->res.count;
+			__entry->eof = hdr->res.eof;
+			__entry->dev = inode->i_sb->s_dev;
+			__entry->fileid = nfsi->fileid;
+			__entry->fhandle = nfs_fhandle_hash(fh);
+		),
+
+		TP_printk(
+			"fileid=%02x:%02x:%llu fhandle=0x%08x "
+			"offset=%lld count=%u res=%u status=%d%s",
+			MAJOR(__entry->dev), MINOR(__entry->dev),
+			(unsigned long long)__entry->fileid,
+			__entry->fhandle,
+			(long long)__entry->offset, __entry->arg_count,
+			__entry->res_count, __entry->status,
+			__entry->eof ? " eof" : ""
+		)
+);
+
+TRACE_EVENT(nfs_pgio_error,
+	TP_PROTO(
+		const struct nfs_pgio_header *hdr,
+		int error,
+		loff_t pos
+	),
+
+	TP_ARGS(hdr, error, pos),
+
+	TP_STRUCT__entry(
+		__field(dev_t, dev)
+		__field(u32, fhandle)
+		__field(u64, fileid)
+		__field(loff_t, offset)
+		__field(u32, arg_count)
+		__field(u32, res_count)
+		__field(loff_t, pos)
+		__field(int, status)
+	),
+
+	TP_fast_assign(
+		const struct inode *inode = hdr->inode;
+		const struct nfs_inode *nfsi = NFS_I(inode);
+		const struct nfs_fh *fh = hdr->args.fh ?
+					  hdr->args.fh : &nfsi->fh;
+
+		__entry->status = error;
+		__entry->offset = hdr->args.offset;
+		__entry->arg_count = hdr->args.count;
+		__entry->res_count = hdr->res.count;
+		__entry->dev = inode->i_sb->s_dev;
+		__entry->fileid = nfsi->fileid;
+		__entry->fhandle = nfs_fhandle_hash(fh);
+	),
+
+	TP_printk("fileid=%02x:%02x:%llu fhandle=0x%08x "
+		  "offset=%lld count=%u res=%u pos=%llu status=%d",
+		MAJOR(__entry->dev), MINOR(__entry->dev),
+		(unsigned long long)__entry->fileid, __entry->fhandle,
+		(long long)__entry->offset, __entry->arg_count, __entry->res_count,
+		__entry->pos, __entry->status
+	)
+);
+
+TRACE_DEFINE_ENUM(NFS_UNSTABLE);
+TRACE_DEFINE_ENUM(NFS_DATA_SYNC);
+TRACE_DEFINE_ENUM(NFS_FILE_SYNC);
+
+#define nfs_show_stable(stable) \
+	__print_symbolic(stable, \
+			{ NFS_UNSTABLE, "UNSTABLE" }, \
+			{ NFS_DATA_SYNC, "DATA_SYNC" }, \
+			{ NFS_FILE_SYNC, "FILE_SYNC" })
+
+TRACE_EVENT(nfs_initiate_write,
+		TP_PROTO(
+			const struct nfs_pgio_header *hdr
+		),
+
+		TP_ARGS(hdr),
+
+		TP_STRUCT__entry(
+			__field(dev_t, dev)
+			__field(u32, fhandle)
+			__field(u64, fileid)
+			__field(loff_t, offset)
+			__field(u32, count)
+			__field(enum nfs3_stable_how, stable)
+		),
+
+		TP_fast_assign(
+			const struct inode *inode = hdr->inode;
+			const struct nfs_inode *nfsi = NFS_I(inode);
+			const struct nfs_fh *fh = hdr->args.fh ?
+						  hdr->args.fh : &nfsi->fh;
+
+			__entry->offset = hdr->args.offset;
+			__entry->count = hdr->args.count;
+			__entry->stable = hdr->args.stable;
+			__entry->dev = inode->i_sb->s_dev;
+			__entry->fileid = nfsi->fileid;
+			__entry->fhandle = nfs_fhandle_hash(fh);
+		),
+
+		TP_printk(
+			"fileid=%02x:%02x:%llu fhandle=0x%08x "
+			"offset=%lld count=%u stable=%s",
+			MAJOR(__entry->dev), MINOR(__entry->dev),
+			(unsigned long long)__entry->fileid,
+			__entry->fhandle,
+			(long long)__entry->offset, __entry->count,
+			nfs_show_stable(__entry->stable)
+		)
+);
+
+TRACE_EVENT(nfs_writeback_done,
+		TP_PROTO(
+			const struct rpc_task *task,
+			const struct nfs_pgio_header *hdr
+		),
+
+		TP_ARGS(task, hdr),
+
+		TP_STRUCT__entry(
+			__field(dev_t, dev)
+			__field(u32, fhandle)
+			__field(u64, fileid)
+			__field(loff_t, offset)
+			__field(u32, arg_count)
+			__field(u32, res_count)
+			__field(int, status)
+			__field(enum nfs3_stable_how, stable)
+			__array(char, verifier, NFS4_VERIFIER_SIZE)
+		),
+
+		TP_fast_assign(
+			const struct inode *inode = hdr->inode;
+			const struct nfs_inode *nfsi = NFS_I(inode);
+			const struct nfs_fh *fh = hdr->args.fh ?
+						  hdr->args.fh : &nfsi->fh;
+			const struct nfs_writeverf *verf = hdr->res.verf;
+
+			__entry->status = task->tk_status;
+			__entry->offset = hdr->args.offset;
+			__entry->arg_count = hdr->args.count;
+			__entry->res_count = hdr->res.count;
+			__entry->stable = verf->committed;
+			memcpy(__entry->verifier,
+				&verf->verifier,
+				NFS4_VERIFIER_SIZE);
+			__entry->dev = inode->i_sb->s_dev;
+			__entry->fileid = nfsi->fileid;
+			__entry->fhandle = nfs_fhandle_hash(fh);
+		),
+
+		TP_printk(
+			"fileid=%02x:%02x:%llu fhandle=0x%08x "
+			"offset=%lld count=%u res=%u status=%d stable=%s "
+			"verifier=%s",
+			MAJOR(__entry->dev), MINOR(__entry->dev),
+			(unsigned long long)__entry->fileid,
+			__entry->fhandle,
+			(long long)__entry->offset, __entry->arg_count,
+			__entry->res_count, __entry->status,
+			nfs_show_stable(__entry->stable),
+			__print_hex_str(__entry->verifier, NFS4_VERIFIER_SIZE)
+		)
+);
+
+DECLARE_EVENT_CLASS(nfs_page_error_class,
+		TP_PROTO(
+			const struct nfs_page *req,
+			int error
+		),
+
+		TP_ARGS(req, error),
+
+		TP_STRUCT__entry(
+			__field(const void *, req)
+			__field(pgoff_t, index)
+			__field(unsigned int, offset)
+			__field(unsigned int, pgbase)
+			__field(unsigned int, bytes)
+			__field(int, error)
+		),
+
+		TP_fast_assign(
+			__entry->req = req;
+			__entry->index = req->wb_index;
+			__entry->offset = req->wb_offset;
+			__entry->pgbase = req->wb_pgbase;
+			__entry->bytes = req->wb_bytes;
+			__entry->error = error;
+		),
+
+		TP_printk(
+			"req=%p index=%lu offset=%u pgbase=%u bytes=%u error=%d",
+			__entry->req, __entry->index, __entry->offset,
+			__entry->pgbase, __entry->bytes, __entry->error
+		)
+);
+
+#define DEFINE_NFS_PAGEERR_EVENT(name) \
+	DEFINE_EVENT(nfs_page_error_class, name, \
+			TP_PROTO( \
+				const struct nfs_page *req, \
+				int error \
+			), \
+			TP_ARGS(req, error))
+
+DEFINE_NFS_PAGEERR_EVENT(nfs_write_error);
+DEFINE_NFS_PAGEERR_EVENT(nfs_comp_error);
+DEFINE_NFS_PAGEERR_EVENT(nfs_commit_error);
+
+TRACE_EVENT(nfs_initiate_commit,
+		TP_PROTO(
+			const struct nfs_commit_data *data
+		),
+
+		TP_ARGS(data),
+
+		TP_STRUCT__entry(
+			__field(dev_t, dev)
+			__field(u32, fhandle)
+			__field(u64, fileid)
+			__field(loff_t, offset)
+			__field(u32, count)
+		),
+
+		TP_fast_assign(
+			const struct inode *inode = data->inode;
+			const struct nfs_inode *nfsi = NFS_I(inode);
+			const struct nfs_fh *fh = data->args.fh ?
+						  data->args.fh : &nfsi->fh;
+
+			__entry->offset = data->args.offset;
+			__entry->count = data->args.count;
+			__entry->dev = inode->i_sb->s_dev;
+			__entry->fileid = nfsi->fileid;
+			__entry->fhandle = nfs_fhandle_hash(fh);
+		),
+
+		TP_printk(
+			"fileid=%02x:%02x:%llu fhandle=0x%08x "
+			"offset=%lld count=%u",
+			MAJOR(__entry->dev), MINOR(__entry->dev),
+			(unsigned long long)__entry->fileid,
+			__entry->fhandle,
+			(long long)__entry->offset, __entry->count
+		)
+);
+
+TRACE_EVENT(nfs_commit_done,
+		TP_PROTO(
+			const struct rpc_task *task,
+			const struct nfs_commit_data *data
+		),
+
+		TP_ARGS(task, data),
+
+		TP_STRUCT__entry(
+			__field(dev_t, dev)
+			__field(u32, fhandle)
+			__field(u64, fileid)
+			__field(loff_t, offset)
+			__field(int, status)
+			__field(enum nfs3_stable_how, stable)
+			__array(char, verifier, NFS4_VERIFIER_SIZE)
+		),
+
+		TP_fast_assign(
+			const struct inode *inode = data->inode;
+			const struct nfs_inode *nfsi = NFS_I(inode);
+			const struct nfs_fh *fh = data->args.fh ?
+						  data->args.fh : &nfsi->fh;
+			const struct nfs_writeverf *verf = data->res.verf;
+
+			__entry->status = task->tk_status;
+			__entry->offset = data->args.offset;
+			__entry->stable = verf->committed;
+			memcpy(__entry->verifier,
+				&verf->verifier,
+				NFS4_VERIFIER_SIZE);
+			__entry->dev = inode->i_sb->s_dev;
+			__entry->fileid = nfsi->fileid;
+			__entry->fhandle = nfs_fhandle_hash(fh);
+		),
+
+		TP_printk(
+			"fileid=%02x:%02x:%llu fhandle=0x%08x "
+			"offset=%lld status=%d stable=%s verifier=%s",
+			MAJOR(__entry->dev), MINOR(__entry->dev),
+			(unsigned long long)__entry->fileid,
+			__entry->fhandle,
+			(long long)__entry->offset, __entry->status,
+			nfs_show_stable(__entry->stable),
+			__print_hex_str(__entry->verifier, NFS4_VERIFIER_SIZE)
+		)
+);
+
+TRACE_EVENT(nfs_fh_to_dentry,
+		TP_PROTO(
+			const struct super_block *sb,
+			const struct nfs_fh *fh,
+			u64 fileid,
+			int error
+		),
+
+		TP_ARGS(sb, fh, fileid, error),
+
+		TP_STRUCT__entry(
+			__field(int, error)
+			__field(dev_t, dev)
+			__field(u32, fhandle)
+			__field(u64, fileid)
+		),
+
+		TP_fast_assign(
+			__entry->error = error;
+			__entry->dev = sb->s_dev;
+			__entry->fileid = fileid;
+			__entry->fhandle = nfs_fhandle_hash(fh);
+		),
+
+		TP_printk(
+			"error=%d fileid=%02x:%02x:%llu fhandle=0x%08x ",
+			__entry->error,
+			MAJOR(__entry->dev), MINOR(__entry->dev),
+			(unsigned long long)__entry->fileid,
+			__entry->fhandle
+		)
+);
+
+TRACE_DEFINE_ENUM(NFS_OK);
+TRACE_DEFINE_ENUM(NFSERR_PERM);
+TRACE_DEFINE_ENUM(NFSERR_NOENT);
+TRACE_DEFINE_ENUM(NFSERR_IO);
+TRACE_DEFINE_ENUM(NFSERR_NXIO);
+TRACE_DEFINE_ENUM(ECHILD);
+TRACE_DEFINE_ENUM(NFSERR_EAGAIN);
+TRACE_DEFINE_ENUM(NFSERR_ACCES);
+TRACE_DEFINE_ENUM(NFSERR_EXIST);
+TRACE_DEFINE_ENUM(NFSERR_XDEV);
+TRACE_DEFINE_ENUM(NFSERR_NODEV);
+TRACE_DEFINE_ENUM(NFSERR_NOTDIR);
+TRACE_DEFINE_ENUM(NFSERR_ISDIR);
+TRACE_DEFINE_ENUM(NFSERR_INVAL);
+TRACE_DEFINE_ENUM(NFSERR_FBIG);
+TRACE_DEFINE_ENUM(NFSERR_NOSPC);
+TRACE_DEFINE_ENUM(NFSERR_ROFS);
+TRACE_DEFINE_ENUM(NFSERR_MLINK);
+TRACE_DEFINE_ENUM(NFSERR_OPNOTSUPP);
+TRACE_DEFINE_ENUM(NFSERR_NAMETOOLONG);
+TRACE_DEFINE_ENUM(NFSERR_NOTEMPTY);
+TRACE_DEFINE_ENUM(NFSERR_DQUOT);
+TRACE_DEFINE_ENUM(NFSERR_STALE);
+TRACE_DEFINE_ENUM(NFSERR_REMOTE);
+TRACE_DEFINE_ENUM(NFSERR_WFLUSH);
+TRACE_DEFINE_ENUM(NFSERR_BADHANDLE);
+TRACE_DEFINE_ENUM(NFSERR_NOT_SYNC);
+TRACE_DEFINE_ENUM(NFSERR_BAD_COOKIE);
+TRACE_DEFINE_ENUM(NFSERR_NOTSUPP);
+TRACE_DEFINE_ENUM(NFSERR_TOOSMALL);
+TRACE_DEFINE_ENUM(NFSERR_SERVERFAULT);
+TRACE_DEFINE_ENUM(NFSERR_BADTYPE);
+TRACE_DEFINE_ENUM(NFSERR_JUKEBOX);
+
+#define nfs_show_status(x) \
+	__print_symbolic(x, \
+			{ NFS_OK, "OK" }, \
+			{ NFSERR_PERM, "PERM" }, \
+			{ NFSERR_NOENT, "NOENT" }, \
+			{ NFSERR_IO, "IO" }, \
+			{ NFSERR_NXIO, "NXIO" }, \
+			{ ECHILD, "CHILD" }, \
+			{ NFSERR_EAGAIN, "AGAIN" }, \
+			{ NFSERR_ACCES, "ACCES" }, \
+			{ NFSERR_EXIST, "EXIST" }, \
+			{ NFSERR_XDEV, "XDEV" }, \
+			{ NFSERR_NODEV, "NODEV" }, \
+			{ NFSERR_NOTDIR, "NOTDIR" }, \
+			{ NFSERR_ISDIR, "ISDIR" }, \
+			{ NFSERR_INVAL, "INVAL" }, \
+			{ NFSERR_FBIG, "FBIG" }, \
+			{ NFSERR_NOSPC, "NOSPC" }, \
+			{ NFSERR_ROFS, "ROFS" }, \
+			{ NFSERR_MLINK, "MLINK" }, \
+			{ NFSERR_OPNOTSUPP, "OPNOTSUPP" }, \
+			{ NFSERR_NAMETOOLONG, "NAMETOOLONG" }, \
+			{ NFSERR_NOTEMPTY, "NOTEMPTY" }, \
+			{ NFSERR_DQUOT, "DQUOT" }, \
+			{ NFSERR_STALE, "STALE" }, \
+			{ NFSERR_REMOTE, "REMOTE" }, \
+			{ NFSERR_WFLUSH, "WFLUSH" }, \
+			{ NFSERR_BADHANDLE, "BADHANDLE" }, \
+			{ NFSERR_NOT_SYNC, "NOTSYNC" }, \
+			{ NFSERR_BAD_COOKIE, "BADCOOKIE" }, \
+			{ NFSERR_NOTSUPP, "NOTSUPP" }, \
+			{ NFSERR_TOOSMALL, "TOOSMALL" }, \
+			{ NFSERR_SERVERFAULT, "REMOTEIO" }, \
+			{ NFSERR_BADTYPE, "BADTYPE" }, \
+			{ NFSERR_JUKEBOX, "JUKEBOX" })
+
+TRACE_EVENT(nfs_xdr_status,
+		TP_PROTO(
+			const struct xdr_stream *xdr,
+			int error
+		),
+
+		TP_ARGS(xdr, error),
+
+		TP_STRUCT__entry(
+			__field(unsigned int, task_id)
+			__field(unsigned int, client_id)
+			__field(u32, xid)
+			__field(int, version)
+			__field(unsigned long, error)
+			__string(program,
+				 xdr->rqst->rq_task->tk_client->cl_program->name)
+			__string(procedure,
+				 xdr->rqst->rq_task->tk_msg.rpc_proc->p_name)
+		),
+
+		TP_fast_assign(
+			const struct rpc_rqst *rqstp = xdr->rqst;
+			const struct rpc_task *task = rqstp->rq_task;
+
+			__entry->task_id = task->tk_pid;
+			__entry->client_id = task->tk_client->cl_clid;
+			__entry->xid = be32_to_cpu(rqstp->rq_xid);
+			__entry->version = task->tk_client->cl_vers;
+			__entry->error = error;
+			__assign_str(program,
+				     task->tk_client->cl_program->name)
+			__assign_str(procedure, task->tk_msg.rpc_proc->p_name)
+		),
+
+		TP_printk(
+			"task:%u@%d xid=0x%08x %sv%d %s error=%ld (%s)",
+			__entry->task_id, __entry->client_id, __entry->xid,
+			__get_str(program), __entry->version,
+			__get_str(procedure), -__entry->error,
+			nfs_show_status(__entry->error)
+		)
+);
+
+#endif /* _TRACE_NFS_H */
+
+#undef TRACE_INCLUDE_PATH
+#define TRACE_INCLUDE_PATH .
+#define TRACE_INCLUDE_FILE nfstrace
+/* This part must be outside protection */
+#include <trace/define_trace.h>
diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
new file mode 100644
index 000000000..17fef6eb4
--- /dev/null
+++ b/fs/nfs/pagelist.c
@@ -0,0 +1,1470 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * linux/fs/nfs/pagelist.c
+ *
+ * A set of helper functions for managing NFS read and write requests.
+ * The main purpose of these routines is to provide support for the
+ * coalescing of several requests into a single RPC call.
+ *
+ * Copyright 2000, 2001 (c) Trond Myklebust <trond.myklebust@fys.uio.no>
+ *
+ */
+
+#include <linux/slab.h>
+#include <linux/file.h>
+#include <linux/sched.h>
+#include <linux/sunrpc/clnt.h>
+#include <linux/nfs.h>
+#include <linux/nfs3.h>
+#include <linux/nfs4.h>
+#include <linux/nfs_fs.h>
+#include <linux/nfs_page.h>
+#include <linux/nfs_mount.h>
+#include <linux/export.h>
+
+#include "internal.h"
+#include "pnfs.h"
+#include "nfstrace.h"
+
+#define NFSDBG_FACILITY		NFSDBG_PAGECACHE
+
+static struct kmem_cache *nfs_page_cachep;
+static const struct rpc_call_ops nfs_pgio_common_ops;
+
+static struct nfs_pgio_mirror *
+nfs_pgio_get_mirror(struct nfs_pageio_descriptor *desc, u32 idx)
+{
+	if (desc->pg_ops->pg_get_mirror)
+		return desc->pg_ops->pg_get_mirror(desc, idx);
+	return &desc->pg_mirrors[0];
+}
+
+struct nfs_pgio_mirror *
+nfs_pgio_current_mirror(struct nfs_pageio_descriptor *desc)
+{
+	return nfs_pgio_get_mirror(desc, desc->pg_mirror_idx);
+}
+EXPORT_SYMBOL_GPL(nfs_pgio_current_mirror);
+
+static u32
+nfs_pgio_set_current_mirror(struct nfs_pageio_descriptor *desc, u32 idx)
+{
+	if (desc->pg_ops->pg_set_mirror)
+		return desc->pg_ops->pg_set_mirror(desc, idx);
+	return desc->pg_mirror_idx;
+}
+
+void nfs_pgheader_init(struct nfs_pageio_descriptor *desc,
+		       struct nfs_pgio_header *hdr,
+		       void (*release)(struct nfs_pgio_header *hdr))
+{
+	struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
+
+
+	hdr->req = nfs_list_entry(mirror->pg_list.next);
+	hdr->inode = desc->pg_inode;
+	hdr->cred = nfs_req_openctx(hdr->req)->cred;
+	hdr->io_start = req_offset(hdr->req);
+	hdr->good_bytes = mirror->pg_count;
+	hdr->io_completion = desc->pg_io_completion;
+	hdr->dreq = desc->pg_dreq;
+	hdr->release = release;
+	hdr->completion_ops = desc->pg_completion_ops;
+	if (hdr->completion_ops->init_hdr)
+		hdr->completion_ops->init_hdr(hdr);
+
+	hdr->pgio_mirror_idx = desc->pg_mirror_idx;
+}
+EXPORT_SYMBOL_GPL(nfs_pgheader_init);
+
+void nfs_set_pgio_error(struct nfs_pgio_header *hdr, int error, loff_t pos)
+{
+	unsigned int new = pos - hdr->io_start;
+
+	trace_nfs_pgio_error(hdr, error, pos);
+	if (hdr->good_bytes > new) {
+		hdr->good_bytes = new;
+		clear_bit(NFS_IOHDR_EOF, &hdr->flags);
+		if (!test_and_set_bit(NFS_IOHDR_ERROR, &hdr->flags))
+			hdr->error = error;
+	}
+}
+
+static inline struct nfs_page *nfs_page_alloc(void)
+{
+	struct nfs_page *p =
+		kmem_cache_zalloc(nfs_page_cachep, nfs_io_gfp_mask());
+	if (p)
+		INIT_LIST_HEAD(&p->wb_list);
+	return p;
+}
+
+static inline void
+nfs_page_free(struct nfs_page *p)
+{
+	kmem_cache_free(nfs_page_cachep, p);
+}
+
+/**
+ * nfs_iocounter_wait - wait for i/o to complete
+ * @l_ctx: nfs_lock_context with io_counter to use
+ *
+ * returns -ERESTARTSYS if interrupted by a fatal signal.
+ * Otherwise returns 0 once the io_count hits 0.
+ */
+int
+nfs_iocounter_wait(struct nfs_lock_context *l_ctx)
+{
+	return wait_var_event_killable(&l_ctx->io_count,
+				       !atomic_read(&l_ctx->io_count));
+}
+
+/**
+ * nfs_async_iocounter_wait - wait on a rpc_waitqueue for I/O
+ * to complete
+ * @task: the rpc_task that should wait
+ * @l_ctx: nfs_lock_context with io_counter to check
+ *
+ * Returns true if there is outstanding I/O to wait on and the
+ * task has been put to sleep.
+ */
+bool
+nfs_async_iocounter_wait(struct rpc_task *task, struct nfs_lock_context *l_ctx)
+{
+	struct inode *inode = d_inode(l_ctx->open_context->dentry);
+	bool ret = false;
+
+	if (atomic_read(&l_ctx->io_count) > 0) {
+		rpc_sleep_on(&NFS_SERVER(inode)->uoc_rpcwaitq, task, NULL);
+		ret = true;
+	}
+
+	if (atomic_read(&l_ctx->io_count) == 0) {
+		rpc_wake_up_queued_task(&NFS_SERVER(inode)->uoc_rpcwaitq, task);
+		ret = false;
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(nfs_async_iocounter_wait);
+
+/*
+ * nfs_page_lock_head_request - page lock the head of the page group
+ * @req: any member of the page group
+ */
+struct nfs_page *
+nfs_page_group_lock_head(struct nfs_page *req)
+{
+	struct nfs_page *head = req->wb_head;
+
+	while (!nfs_lock_request(head)) {
+		int ret = nfs_wait_on_request(head);
+		if (ret < 0)
+			return ERR_PTR(ret);
+	}
+	if (head != req)
+		kref_get(&head->wb_kref);
+	return head;
+}
+
+/*
+ * nfs_unroll_locks -  unlock all newly locked reqs and wait on @req
+ * @head: head request of page group, must be holding head lock
+ * @req: request that couldn't lock and needs to wait on the req bit lock
+ *
+ * This is a helper function for nfs_lock_and_join_requests
+ * returns 0 on success, < 0 on error.
+ */
+static void
+nfs_unroll_locks(struct nfs_page *head, struct nfs_page *req)
+{
+	struct nfs_page *tmp;
+
+	/* relinquish all the locks successfully grabbed this run */
+	for (tmp = head->wb_this_page ; tmp != req; tmp = tmp->wb_this_page) {
+		if (!kref_read(&tmp->wb_kref))
+			continue;
+		nfs_unlock_and_release_request(tmp);
+	}
+}
+
+/*
+ * nfs_page_group_lock_subreq -  try to lock a subrequest
+ * @head: head request of page group
+ * @subreq: request to lock
+ *
+ * This is a helper function for nfs_lock_and_join_requests which
+ * must be called with the head request and page group both locked.
+ * On error, it returns with the page group unlocked.
+ */
+static int
+nfs_page_group_lock_subreq(struct nfs_page *head, struct nfs_page *subreq)
+{
+	int ret;
+
+	if (!kref_get_unless_zero(&subreq->wb_kref))
+		return 0;
+	while (!nfs_lock_request(subreq)) {
+		nfs_page_group_unlock(head);
+		ret = nfs_wait_on_request(subreq);
+		if (!ret)
+			ret = nfs_page_group_lock(head);
+		if (ret < 0) {
+			nfs_unroll_locks(head, subreq);
+			nfs_release_request(subreq);
+			return ret;
+		}
+	}
+	return 0;
+}
+
+/*
+ * nfs_page_group_lock_subrequests -  try to lock the subrequests
+ * @head: head request of page group
+ *
+ * This is a helper function for nfs_lock_and_join_requests which
+ * must be called with the head request locked.
+ */
+int nfs_page_group_lock_subrequests(struct nfs_page *head)
+{
+	struct nfs_page *subreq;
+	int ret;
+
+	ret = nfs_page_group_lock(head);
+	if (ret < 0)
+		return ret;
+	/* lock each request in the page group */
+	for (subreq = head->wb_this_page; subreq != head;
+			subreq = subreq->wb_this_page) {
+		ret = nfs_page_group_lock_subreq(head, subreq);
+		if (ret < 0)
+			return ret;
+	}
+	nfs_page_group_unlock(head);
+	return 0;
+}
+
+/*
+ * nfs_page_set_headlock - set the request PG_HEADLOCK
+ * @req: request that is to be locked
+ *
+ * this lock must be held when modifying req->wb_head
+ *
+ * return 0 on success, < 0 on error
+ */
+int
+nfs_page_set_headlock(struct nfs_page *req)
+{
+	if (!test_and_set_bit(PG_HEADLOCK, &req->wb_flags))
+		return 0;
+
+	set_bit(PG_CONTENDED1, &req->wb_flags);
+	smp_mb__after_atomic();
+	return wait_on_bit_lock(&req->wb_flags, PG_HEADLOCK,
+				TASK_UNINTERRUPTIBLE);
+}
+
+/*
+ * nfs_page_clear_headlock - clear the request PG_HEADLOCK
+ * @req: request that is to be locked
+ */
+void
+nfs_page_clear_headlock(struct nfs_page *req)
+{
+	smp_mb__before_atomic();
+	clear_bit(PG_HEADLOCK, &req->wb_flags);
+	smp_mb__after_atomic();
+	if (!test_bit(PG_CONTENDED1, &req->wb_flags))
+		return;
+	wake_up_bit(&req->wb_flags, PG_HEADLOCK);
+}
+
+/*
+ * nfs_page_group_lock - lock the head of the page group
+ * @req: request in group that is to be locked
+ *
+ * this lock must be held when traversing or modifying the page
+ * group list
+ *
+ * return 0 on success, < 0 on error
+ */
+int
+nfs_page_group_lock(struct nfs_page *req)
+{
+	int ret;
+
+	ret = nfs_page_set_headlock(req);
+	if (ret || req->wb_head == req)
+		return ret;
+	return nfs_page_set_headlock(req->wb_head);
+}
+
+/*
+ * nfs_page_group_unlock - unlock the head of the page group
+ * @req: request in group that is to be unlocked
+ */
+void
+nfs_page_group_unlock(struct nfs_page *req)
+{
+	if (req != req->wb_head)
+		nfs_page_clear_headlock(req->wb_head);
+	nfs_page_clear_headlock(req);
+}
+
+/*
+ * nfs_page_group_sync_on_bit_locked
+ *
+ * must be called with page group lock held
+ */
+static bool
+nfs_page_group_sync_on_bit_locked(struct nfs_page *req, unsigned int bit)
+{
+	struct nfs_page *head = req->wb_head;
+	struct nfs_page *tmp;
+
+	WARN_ON_ONCE(!test_bit(PG_HEADLOCK, &head->wb_flags));
+	WARN_ON_ONCE(test_and_set_bit(bit, &req->wb_flags));
+
+	tmp = req->wb_this_page;
+	while (tmp != req) {
+		if (!test_bit(bit, &tmp->wb_flags))
+			return false;
+		tmp = tmp->wb_this_page;
+	}
+
+	/* true! reset all bits */
+	tmp = req;
+	do {
+		clear_bit(bit, &tmp->wb_flags);
+		tmp = tmp->wb_this_page;
+	} while (tmp != req);
+
+	return true;
+}
+
+/*
+ * nfs_page_group_sync_on_bit - set bit on current request, but only
+ *   return true if the bit is set for all requests in page group
+ * @req - request in page group
+ * @bit - PG_* bit that is used to sync page group
+ */
+bool nfs_page_group_sync_on_bit(struct nfs_page *req, unsigned int bit)
+{
+	bool ret;
+
+	nfs_page_group_lock(req);
+	ret = nfs_page_group_sync_on_bit_locked(req, bit);
+	nfs_page_group_unlock(req);
+
+	return ret;
+}
+
+/*
+ * nfs_page_group_init - Initialize the page group linkage for @req
+ * @req - a new nfs request
+ * @prev - the previous request in page group, or NULL if @req is the first
+ *         or only request in the group (the head).
+ */
+static inline void
+nfs_page_group_init(struct nfs_page *req, struct nfs_page *prev)
+{
+	struct inode *inode;
+	WARN_ON_ONCE(prev == req);
+
+	if (!prev) {
+		/* a head request */
+		req->wb_head = req;
+		req->wb_this_page = req;
+	} else {
+		/* a subrequest */
+		WARN_ON_ONCE(prev->wb_this_page != prev->wb_head);
+		WARN_ON_ONCE(!test_bit(PG_HEADLOCK, &prev->wb_head->wb_flags));
+		req->wb_head = prev->wb_head;
+		req->wb_this_page = prev->wb_this_page;
+		prev->wb_this_page = req;
+
+		/* All subrequests take a ref on the head request until
+		 * nfs_page_group_destroy is called */
+		kref_get(&req->wb_head->wb_kref);
+
+		/* grab extra ref and bump the request count if head request
+		 * has extra ref from the write/commit path to handle handoff
+		 * between write and commit lists. */
+		if (test_bit(PG_INODE_REF, &prev->wb_head->wb_flags)) {
+			inode = page_file_mapping(req->wb_page)->host;
+			set_bit(PG_INODE_REF, &req->wb_flags);
+			kref_get(&req->wb_kref);
+			atomic_long_inc(&NFS_I(inode)->nrequests);
+		}
+	}
+}
+
+/*
+ * nfs_page_group_destroy - sync the destruction of page groups
+ * @req - request that no longer needs the page group
+ *
+ * releases the page group reference from each member once all
+ * members have called this function.
+ */
+static void
+nfs_page_group_destroy(struct kref *kref)
+{
+	struct nfs_page *req = container_of(kref, struct nfs_page, wb_kref);
+	struct nfs_page *head = req->wb_head;
+	struct nfs_page *tmp, *next;
+
+	if (!nfs_page_group_sync_on_bit(req, PG_TEARDOWN))
+		goto out;
+
+	tmp = req;
+	do {
+		next = tmp->wb_this_page;
+		/* unlink and free */
+		tmp->wb_this_page = tmp;
+		tmp->wb_head = tmp;
+		nfs_free_request(tmp);
+		tmp = next;
+	} while (tmp != req);
+out:
+	/* subrequests must release the ref on the head request */
+	if (head != req)
+		nfs_release_request(head);
+}
+
+static struct nfs_page *
+__nfs_create_request(struct nfs_lock_context *l_ctx, struct page *page,
+		   unsigned int pgbase, unsigned int offset,
+		   unsigned int count)
+{
+	struct nfs_page		*req;
+	struct nfs_open_context *ctx = l_ctx->open_context;
+
+	if (test_bit(NFS_CONTEXT_BAD, &ctx->flags))
+		return ERR_PTR(-EBADF);
+	/* try to allocate the request struct */
+	req = nfs_page_alloc();
+	if (req == NULL)
+		return ERR_PTR(-ENOMEM);
+
+	req->wb_lock_context = l_ctx;
+	refcount_inc(&l_ctx->count);
+	atomic_inc(&l_ctx->io_count);
+
+	/* Initialize the request struct. Initially, we assume a
+	 * long write-back delay. This will be adjusted in
+	 * update_nfs_request below if the region is not locked. */
+	req->wb_page    = page;
+	if (page) {
+		req->wb_index = page_index(page);
+		get_page(page);
+	}
+	req->wb_offset  = offset;
+	req->wb_pgbase	= pgbase;
+	req->wb_bytes   = count;
+	kref_init(&req->wb_kref);
+	req->wb_nio = 0;
+	return req;
+}
+
+/**
+ * nfs_create_request - Create an NFS read/write request.
+ * @ctx: open context to use
+ * @page: page to write
+ * @offset: starting offset within the page for the write
+ * @count: number of bytes to read/write
+ *
+ * The page must be locked by the caller. This makes sure we never
+ * create two different requests for the same page.
+ * User should ensure it is safe to sleep in this function.
+ */
+struct nfs_page *
+nfs_create_request(struct nfs_open_context *ctx, struct page *page,
+		   unsigned int offset, unsigned int count)
+{
+	struct nfs_lock_context *l_ctx = nfs_get_lock_context(ctx);
+	struct nfs_page *ret;
+
+	if (IS_ERR(l_ctx))
+		return ERR_CAST(l_ctx);
+	ret = __nfs_create_request(l_ctx, page, offset, offset, count);
+	if (!IS_ERR(ret))
+		nfs_page_group_init(ret, NULL);
+	nfs_put_lock_context(l_ctx);
+	return ret;
+}
+
+static struct nfs_page *
+nfs_create_subreq(struct nfs_page *req,
+		  unsigned int pgbase,
+		  unsigned int offset,
+		  unsigned int count)
+{
+	struct nfs_page *last;
+	struct nfs_page *ret;
+
+	ret = __nfs_create_request(req->wb_lock_context, req->wb_page,
+			pgbase, offset, count);
+	if (!IS_ERR(ret)) {
+		/* find the last request */
+		for (last = req->wb_head;
+		     last->wb_this_page != req->wb_head;
+		     last = last->wb_this_page)
+			;
+
+		nfs_lock_request(ret);
+		ret->wb_index = req->wb_index;
+		nfs_page_group_init(ret, last);
+		ret->wb_nio = req->wb_nio;
+	}
+	return ret;
+}
+
+/**
+ * nfs_unlock_request - Unlock request and wake up sleepers.
+ * @req: pointer to request
+ */
+void nfs_unlock_request(struct nfs_page *req)
+{
+	if (!NFS_WBACK_BUSY(req)) {
+		printk(KERN_ERR "NFS: Invalid unlock attempted\n");
+		BUG();
+	}
+	smp_mb__before_atomic();
+	clear_bit(PG_BUSY, &req->wb_flags);
+	smp_mb__after_atomic();
+	if (!test_bit(PG_CONTENDED2, &req->wb_flags))
+		return;
+	wake_up_bit(&req->wb_flags, PG_BUSY);
+}
+
+/**
+ * nfs_unlock_and_release_request - Unlock request and release the nfs_page
+ * @req: pointer to request
+ */
+void nfs_unlock_and_release_request(struct nfs_page *req)
+{
+	nfs_unlock_request(req);
+	nfs_release_request(req);
+}
+
+/*
+ * nfs_clear_request - Free up all resources allocated to the request
+ * @req:
+ *
+ * Release page and open context resources associated with a read/write
+ * request after it has completed.
+ */
+static void nfs_clear_request(struct nfs_page *req)
+{
+	struct page *page = req->wb_page;
+	struct nfs_lock_context *l_ctx = req->wb_lock_context;
+	struct nfs_open_context *ctx;
+
+	if (page != NULL) {
+		put_page(page);
+		req->wb_page = NULL;
+	}
+	if (l_ctx != NULL) {
+		if (atomic_dec_and_test(&l_ctx->io_count)) {
+			wake_up_var(&l_ctx->io_count);
+			ctx = l_ctx->open_context;
+			if (test_bit(NFS_CONTEXT_UNLOCK, &ctx->flags))
+				rpc_wake_up(&NFS_SERVER(d_inode(ctx->dentry))->uoc_rpcwaitq);
+		}
+		nfs_put_lock_context(l_ctx);
+		req->wb_lock_context = NULL;
+	}
+}
+
+/**
+ * nfs_release_request - Release the count on an NFS read/write request
+ * @req: request to release
+ *
+ * Note: Should never be called with the spinlock held!
+ */
+void nfs_free_request(struct nfs_page *req)
+{
+	WARN_ON_ONCE(req->wb_this_page != req);
+
+	/* extra debug: make sure no sync bits are still set */
+	WARN_ON_ONCE(test_bit(PG_TEARDOWN, &req->wb_flags));
+	WARN_ON_ONCE(test_bit(PG_UNLOCKPAGE, &req->wb_flags));
+	WARN_ON_ONCE(test_bit(PG_UPTODATE, &req->wb_flags));
+	WARN_ON_ONCE(test_bit(PG_WB_END, &req->wb_flags));
+	WARN_ON_ONCE(test_bit(PG_REMOVE, &req->wb_flags));
+
+	/* Release struct file and open context */
+	nfs_clear_request(req);
+	nfs_page_free(req);
+}
+
+void nfs_release_request(struct nfs_page *req)
+{
+	kref_put(&req->wb_kref, nfs_page_group_destroy);
+}
+EXPORT_SYMBOL_GPL(nfs_release_request);
+
+/**
+ * nfs_wait_on_request - Wait for a request to complete.
+ * @req: request to wait upon.
+ *
+ * Interruptible by fatal signals only.
+ * The user is responsible for holding a count on the request.
+ */
+int
+nfs_wait_on_request(struct nfs_page *req)
+{
+	if (!test_bit(PG_BUSY, &req->wb_flags))
+		return 0;
+	set_bit(PG_CONTENDED2, &req->wb_flags);
+	smp_mb__after_atomic();
+	return wait_on_bit_io(&req->wb_flags, PG_BUSY,
+			      TASK_UNINTERRUPTIBLE);
+}
+EXPORT_SYMBOL_GPL(nfs_wait_on_request);
+
+/*
+ * nfs_generic_pg_test - determine if requests can be coalesced
+ * @desc: pointer to descriptor
+ * @prev: previous request in desc, or NULL
+ * @req: this request
+ *
+ * Returns zero if @req cannot be coalesced into @desc, otherwise it returns
+ * the size of the request.
+ */
+size_t nfs_generic_pg_test(struct nfs_pageio_descriptor *desc,
+			   struct nfs_page *prev, struct nfs_page *req)
+{
+	struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
+
+
+	if (mirror->pg_count > mirror->pg_bsize) {
+		/* should never happen */
+		WARN_ON_ONCE(1);
+		return 0;
+	}
+
+	/*
+	 * Limit the request size so that we can still allocate a page array
+	 * for it without upsetting the slab allocator.
+	 */
+	if (((mirror->pg_count + req->wb_bytes) >> PAGE_SHIFT) *
+			sizeof(struct page *) > PAGE_SIZE)
+		return 0;
+
+	return min(mirror->pg_bsize - mirror->pg_count, (size_t)req->wb_bytes);
+}
+EXPORT_SYMBOL_GPL(nfs_generic_pg_test);
+
+struct nfs_pgio_header *nfs_pgio_header_alloc(const struct nfs_rw_ops *ops)
+{
+	struct nfs_pgio_header *hdr = ops->rw_alloc_header();
+
+	if (hdr) {
+		INIT_LIST_HEAD(&hdr->pages);
+		hdr->rw_ops = ops;
+	}
+	return hdr;
+}
+EXPORT_SYMBOL_GPL(nfs_pgio_header_alloc);
+
+/**
+ * nfs_pgio_data_destroy - make @hdr suitable for reuse
+ *
+ * Frees memory and releases refs from nfs_generic_pgio, so that it may
+ * be called again.
+ *
+ * @hdr: A header that has had nfs_generic_pgio called
+ */
+static void nfs_pgio_data_destroy(struct nfs_pgio_header *hdr)
+{
+	if (hdr->args.context)
+		put_nfs_open_context(hdr->args.context);
+	if (hdr->page_array.pagevec != hdr->page_array.page_array)
+		kfree(hdr->page_array.pagevec);
+}
+
+/*
+ * nfs_pgio_header_free - Free a read or write header
+ * @hdr: The header to free
+ */
+void nfs_pgio_header_free(struct nfs_pgio_header *hdr)
+{
+	nfs_pgio_data_destroy(hdr);
+	hdr->rw_ops->rw_free_header(hdr);
+}
+EXPORT_SYMBOL_GPL(nfs_pgio_header_free);
+
+/**
+ * nfs_pgio_rpcsetup - Set up arguments for a pageio call
+ * @hdr: The pageio hdr
+ * @count: Number of bytes to read
+ * @how: How to commit data (writes only)
+ * @cinfo: Commit information for the call (writes only)
+ */
+static void nfs_pgio_rpcsetup(struct nfs_pgio_header *hdr,
+			      unsigned int count,
+			      int how, struct nfs_commit_info *cinfo)
+{
+	struct nfs_page *req = hdr->req;
+
+	/* Set up the RPC argument and reply structs
+	 * NB: take care not to mess about with hdr->commit et al. */
+
+	hdr->args.fh     = NFS_FH(hdr->inode);
+	hdr->args.offset = req_offset(req);
+	/* pnfs_set_layoutcommit needs this */
+	hdr->mds_offset = hdr->args.offset;
+	hdr->args.pgbase = req->wb_pgbase;
+	hdr->args.pages  = hdr->page_array.pagevec;
+	hdr->args.count  = count;
+	hdr->args.context = get_nfs_open_context(nfs_req_openctx(req));
+	hdr->args.lock_context = req->wb_lock_context;
+	hdr->args.stable  = NFS_UNSTABLE;
+	switch (how & (FLUSH_STABLE | FLUSH_COND_STABLE)) {
+	case 0:
+		break;
+	case FLUSH_COND_STABLE:
+		if (nfs_reqs_to_commit(cinfo))
+			break;
+		fallthrough;
+	default:
+		hdr->args.stable = NFS_FILE_SYNC;
+	}
+
+	hdr->res.fattr   = &hdr->fattr;
+	hdr->res.count   = 0;
+	hdr->res.eof     = 0;
+	hdr->res.verf    = &hdr->verf;
+	nfs_fattr_init(&hdr->fattr);
+}
+
+/**
+ * nfs_pgio_prepare - Prepare pageio hdr to go over the wire
+ * @task: The current task
+ * @calldata: pageio header to prepare
+ */
+static void nfs_pgio_prepare(struct rpc_task *task, void *calldata)
+{
+	struct nfs_pgio_header *hdr = calldata;
+	int err;
+	err = NFS_PROTO(hdr->inode)->pgio_rpc_prepare(task, hdr);
+	if (err)
+		rpc_exit(task, err);
+}
+
+int nfs_initiate_pgio(struct rpc_clnt *clnt, struct nfs_pgio_header *hdr,
+		      const struct cred *cred, const struct nfs_rpc_ops *rpc_ops,
+		      const struct rpc_call_ops *call_ops, int how, int flags)
+{
+	struct rpc_task *task;
+	struct rpc_message msg = {
+		.rpc_argp = &hdr->args,
+		.rpc_resp = &hdr->res,
+		.rpc_cred = cred,
+	};
+	struct rpc_task_setup task_setup_data = {
+		.rpc_client = clnt,
+		.task = &hdr->task,
+		.rpc_message = &msg,
+		.callback_ops = call_ops,
+		.callback_data = hdr,
+		.workqueue = nfsiod_workqueue,
+		.flags = RPC_TASK_ASYNC | flags,
+	};
+
+	hdr->rw_ops->rw_initiate(hdr, &msg, rpc_ops, &task_setup_data, how);
+
+	dprintk("NFS: initiated pgio call "
+		"(req %s/%llu, %u bytes @ offset %llu)\n",
+		hdr->inode->i_sb->s_id,
+		(unsigned long long)NFS_FILEID(hdr->inode),
+		hdr->args.count,
+		(unsigned long long)hdr->args.offset);
+
+	task = rpc_run_task(&task_setup_data);
+	if (IS_ERR(task))
+		return PTR_ERR(task);
+	rpc_put_task(task);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nfs_initiate_pgio);
+
+/**
+ * nfs_pgio_error - Clean up from a pageio error
+ * @hdr: pageio header
+ */
+static void nfs_pgio_error(struct nfs_pgio_header *hdr)
+{
+	set_bit(NFS_IOHDR_REDO, &hdr->flags);
+	hdr->completion_ops->completion(hdr);
+}
+
+/**
+ * nfs_pgio_release - Release pageio data
+ * @calldata: The pageio header to release
+ */
+static void nfs_pgio_release(void *calldata)
+{
+	struct nfs_pgio_header *hdr = calldata;
+	hdr->completion_ops->completion(hdr);
+}
+
+static void nfs_pageio_mirror_init(struct nfs_pgio_mirror *mirror,
+				   unsigned int bsize)
+{
+	INIT_LIST_HEAD(&mirror->pg_list);
+	mirror->pg_bytes_written = 0;
+	mirror->pg_count = 0;
+	mirror->pg_bsize = bsize;
+	mirror->pg_base = 0;
+	mirror->pg_recoalesce = 0;
+}
+
+/**
+ * nfs_pageio_init - initialise a page io descriptor
+ * @desc: pointer to descriptor
+ * @inode: pointer to inode
+ * @pg_ops: pointer to pageio operations
+ * @compl_ops: pointer to pageio completion operations
+ * @rw_ops: pointer to nfs read/write operations
+ * @bsize: io block size
+ * @io_flags: extra parameters for the io function
+ */
+void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
+		     struct inode *inode,
+		     const struct nfs_pageio_ops *pg_ops,
+		     const struct nfs_pgio_completion_ops *compl_ops,
+		     const struct nfs_rw_ops *rw_ops,
+		     size_t bsize,
+		     int io_flags)
+{
+	desc->pg_moreio = 0;
+	desc->pg_inode = inode;
+	desc->pg_ops = pg_ops;
+	desc->pg_completion_ops = compl_ops;
+	desc->pg_rw_ops = rw_ops;
+	desc->pg_ioflags = io_flags;
+	desc->pg_error = 0;
+	desc->pg_lseg = NULL;
+	desc->pg_io_completion = NULL;
+	desc->pg_dreq = NULL;
+	desc->pg_bsize = bsize;
+
+	desc->pg_mirror_count = 1;
+	desc->pg_mirror_idx = 0;
+
+	desc->pg_mirrors_dynamic = NULL;
+	desc->pg_mirrors = desc->pg_mirrors_static;
+	nfs_pageio_mirror_init(&desc->pg_mirrors[0], bsize);
+	desc->pg_maxretrans = 0;
+}
+
+/**
+ * nfs_pgio_result - Basic pageio error handling
+ * @task: The task that ran
+ * @calldata: Pageio header to check
+ */
+static void nfs_pgio_result(struct rpc_task *task, void *calldata)
+{
+	struct nfs_pgio_header *hdr = calldata;
+	struct inode *inode = hdr->inode;
+
+	dprintk("NFS: %s: %5u, (status %d)\n", __func__,
+		task->tk_pid, task->tk_status);
+
+	if (hdr->rw_ops->rw_done(task, hdr, inode) != 0)
+		return;
+	if (task->tk_status < 0)
+		nfs_set_pgio_error(hdr, task->tk_status, hdr->args.offset);
+	else
+		hdr->rw_ops->rw_result(task, hdr);
+}
+
+/*
+ * Create an RPC task for the given read or write request and kick it.
+ * The page must have been locked by the caller.
+ *
+ * It may happen that the page we're passed is not marked dirty.
+ * This is the case if nfs_updatepage detects a conflicting request
+ * that has been written but not committed.
+ */
+int nfs_generic_pgio(struct nfs_pageio_descriptor *desc,
+		     struct nfs_pgio_header *hdr)
+{
+	struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
+
+	struct nfs_page		*req;
+	struct page		**pages,
+				*last_page;
+	struct list_head *head = &mirror->pg_list;
+	struct nfs_commit_info cinfo;
+	struct nfs_page_array *pg_array = &hdr->page_array;
+	unsigned int pagecount, pageused;
+	gfp_t gfp_flags = nfs_io_gfp_mask();
+
+	pagecount = nfs_page_array_len(mirror->pg_base, mirror->pg_count);
+	pg_array->npages = pagecount;
+
+	if (pagecount <= ARRAY_SIZE(pg_array->page_array))
+		pg_array->pagevec = pg_array->page_array;
+	else {
+		pg_array->pagevec = kcalloc(pagecount, sizeof(struct page *), gfp_flags);
+		if (!pg_array->pagevec) {
+			pg_array->npages = 0;
+			nfs_pgio_error(hdr);
+			desc->pg_error = -ENOMEM;
+			return desc->pg_error;
+		}
+	}
+
+	nfs_init_cinfo(&cinfo, desc->pg_inode, desc->pg_dreq);
+	pages = hdr->page_array.pagevec;
+	last_page = NULL;
+	pageused = 0;
+	while (!list_empty(head)) {
+		req = nfs_list_entry(head->next);
+		nfs_list_move_request(req, &hdr->pages);
+
+		if (!last_page || last_page != req->wb_page) {
+			pageused++;
+			if (pageused > pagecount)
+				break;
+			*pages++ = last_page = req->wb_page;
+		}
+	}
+	if (WARN_ON_ONCE(pageused != pagecount)) {
+		nfs_pgio_error(hdr);
+		desc->pg_error = -EINVAL;
+		return desc->pg_error;
+	}
+
+	if ((desc->pg_ioflags & FLUSH_COND_STABLE) &&
+	    (desc->pg_moreio || nfs_reqs_to_commit(&cinfo)))
+		desc->pg_ioflags &= ~FLUSH_COND_STABLE;
+
+	/* Set up the argument struct */
+	nfs_pgio_rpcsetup(hdr, mirror->pg_count, desc->pg_ioflags, &cinfo);
+	desc->pg_rpc_callops = &nfs_pgio_common_ops;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nfs_generic_pgio);
+
+static int nfs_generic_pg_pgios(struct nfs_pageio_descriptor *desc)
+{
+	struct nfs_pgio_header *hdr;
+	int ret;
+
+	hdr = nfs_pgio_header_alloc(desc->pg_rw_ops);
+	if (!hdr) {
+		desc->pg_error = -ENOMEM;
+		return desc->pg_error;
+	}
+	nfs_pgheader_init(desc, hdr, nfs_pgio_header_free);
+	ret = nfs_generic_pgio(desc, hdr);
+	if (ret == 0)
+		ret = nfs_initiate_pgio(NFS_CLIENT(hdr->inode),
+					hdr,
+					hdr->cred,
+					NFS_PROTO(hdr->inode),
+					desc->pg_rpc_callops,
+					desc->pg_ioflags,
+					RPC_TASK_CRED_NOREF);
+	return ret;
+}
+
+static struct nfs_pgio_mirror *
+nfs_pageio_alloc_mirrors(struct nfs_pageio_descriptor *desc,
+		unsigned int mirror_count)
+{
+	struct nfs_pgio_mirror *ret;
+	unsigned int i;
+
+	kfree(desc->pg_mirrors_dynamic);
+	desc->pg_mirrors_dynamic = NULL;
+	if (mirror_count == 1)
+		return desc->pg_mirrors_static;
+	ret = kmalloc_array(mirror_count, sizeof(*ret), nfs_io_gfp_mask());
+	if (ret != NULL) {
+		for (i = 0; i < mirror_count; i++)
+			nfs_pageio_mirror_init(&ret[i], desc->pg_bsize);
+		desc->pg_mirrors_dynamic = ret;
+	}
+	return ret;
+}
+
+/*
+ * nfs_pageio_setup_mirroring - determine if mirroring is to be used
+ *				by calling the pg_get_mirror_count op
+ */
+static void nfs_pageio_setup_mirroring(struct nfs_pageio_descriptor *pgio,
+				       struct nfs_page *req)
+{
+	unsigned int mirror_count = 1;
+
+	if (pgio->pg_ops->pg_get_mirror_count)
+		mirror_count = pgio->pg_ops->pg_get_mirror_count(pgio, req);
+	if (mirror_count == pgio->pg_mirror_count || pgio->pg_error < 0)
+		return;
+
+	if (!mirror_count || mirror_count > NFS_PAGEIO_DESCRIPTOR_MIRROR_MAX) {
+		pgio->pg_error = -EINVAL;
+		return;
+	}
+
+	pgio->pg_mirrors = nfs_pageio_alloc_mirrors(pgio, mirror_count);
+	if (pgio->pg_mirrors == NULL) {
+		pgio->pg_error = -ENOMEM;
+		pgio->pg_mirrors = pgio->pg_mirrors_static;
+		mirror_count = 1;
+	}
+	pgio->pg_mirror_count = mirror_count;
+}
+
+static void nfs_pageio_cleanup_mirroring(struct nfs_pageio_descriptor *pgio)
+{
+	pgio->pg_mirror_count = 1;
+	pgio->pg_mirror_idx = 0;
+	pgio->pg_mirrors = pgio->pg_mirrors_static;
+	kfree(pgio->pg_mirrors_dynamic);
+	pgio->pg_mirrors_dynamic = NULL;
+}
+
+static bool nfs_match_lock_context(const struct nfs_lock_context *l1,
+		const struct nfs_lock_context *l2)
+{
+	return l1->lockowner == l2->lockowner;
+}
+
+/**
+ * nfs_coalesce_size - test two requests for compatibility
+ * @prev: pointer to nfs_page
+ * @req: pointer to nfs_page
+ * @pgio: pointer to nfs_pagio_descriptor
+ *
+ * The nfs_page structures 'prev' and 'req' are compared to ensure that the
+ * page data area they describe is contiguous, and that their RPC
+ * credentials, NFSv4 open state, and lockowners are the same.
+ *
+ * Returns size of the request that can be coalesced
+ */
+static unsigned int nfs_coalesce_size(struct nfs_page *prev,
+				      struct nfs_page *req,
+				      struct nfs_pageio_descriptor *pgio)
+{
+	struct file_lock_context *flctx;
+
+	if (prev) {
+		if (!nfs_match_open_context(nfs_req_openctx(req), nfs_req_openctx(prev)))
+			return 0;
+		flctx = d_inode(nfs_req_openctx(req)->dentry)->i_flctx;
+		if (flctx != NULL &&
+		    !(list_empty_careful(&flctx->flc_posix) &&
+		      list_empty_careful(&flctx->flc_flock)) &&
+		    !nfs_match_lock_context(req->wb_lock_context,
+					    prev->wb_lock_context))
+			return 0;
+		if (req_offset(req) != req_offset(prev) + prev->wb_bytes)
+			return 0;
+		if (req->wb_page == prev->wb_page) {
+			if (req->wb_pgbase != prev->wb_pgbase + prev->wb_bytes)
+				return 0;
+		} else {
+			if (req->wb_pgbase != 0 ||
+			    prev->wb_pgbase + prev->wb_bytes != PAGE_SIZE)
+				return 0;
+		}
+	}
+	return pgio->pg_ops->pg_test(pgio, prev, req);
+}
+
+/**
+ * nfs_pageio_do_add_request - Attempt to coalesce a request into a page list.
+ * @desc: destination io descriptor
+ * @req: request
+ *
+ * If the request 'req' was successfully coalesced into the existing list
+ * of pages 'desc', it returns the size of req.
+ */
+static unsigned int
+nfs_pageio_do_add_request(struct nfs_pageio_descriptor *desc,
+		struct nfs_page *req)
+{
+	struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
+	struct nfs_page *prev = NULL;
+	unsigned int size;
+
+	if (list_empty(&mirror->pg_list)) {
+		if (desc->pg_ops->pg_init)
+			desc->pg_ops->pg_init(desc, req);
+		if (desc->pg_error < 0)
+			return 0;
+		mirror->pg_base = req->wb_pgbase;
+		mirror->pg_count = 0;
+		mirror->pg_recoalesce = 0;
+	} else
+		prev = nfs_list_entry(mirror->pg_list.prev);
+
+	if (desc->pg_maxretrans && req->wb_nio > desc->pg_maxretrans) {
+		if (NFS_SERVER(desc->pg_inode)->flags & NFS_MOUNT_SOFTERR)
+			desc->pg_error = -ETIMEDOUT;
+		else
+			desc->pg_error = -EIO;
+		return 0;
+	}
+
+	size = nfs_coalesce_size(prev, req, desc);
+	if (size < req->wb_bytes)
+		return size;
+	nfs_list_move_request(req, &mirror->pg_list);
+	mirror->pg_count += req->wb_bytes;
+	return req->wb_bytes;
+}
+
+/*
+ * Helper for nfs_pageio_add_request and nfs_pageio_complete
+ */
+static void nfs_pageio_doio(struct nfs_pageio_descriptor *desc)
+{
+	struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
+
+	if (!list_empty(&mirror->pg_list)) {
+		int error = desc->pg_ops->pg_doio(desc);
+		if (error < 0)
+			desc->pg_error = error;
+		if (list_empty(&mirror->pg_list)) {
+			mirror->pg_bytes_written += mirror->pg_count;
+			mirror->pg_count = 0;
+			mirror->pg_base = 0;
+			mirror->pg_recoalesce = 0;
+		}
+	}
+}
+
+static void
+nfs_pageio_cleanup_request(struct nfs_pageio_descriptor *desc,
+		struct nfs_page *req)
+{
+	LIST_HEAD(head);
+
+	nfs_list_move_request(req, &head);
+	desc->pg_completion_ops->error_cleanup(&head, desc->pg_error);
+}
+
+/**
+ * nfs_pageio_add_request - Attempt to coalesce a request into a page list.
+ * @desc: destination io descriptor
+ * @req: request
+ *
+ * This may split a request into subrequests which are all part of the
+ * same page group. If so, it will submit @req as the last one, to ensure
+ * the pointer to @req is still valid in case of failure.
+ *
+ * Returns true if the request 'req' was successfully coalesced into the
+ * existing list of pages 'desc'.
+ */
+static int __nfs_pageio_add_request(struct nfs_pageio_descriptor *desc,
+			   struct nfs_page *req)
+{
+	struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
+	struct nfs_page *subreq;
+	unsigned int size, subreq_size;
+
+	nfs_page_group_lock(req);
+
+	subreq = req;
+	subreq_size = subreq->wb_bytes;
+	for(;;) {
+		size = nfs_pageio_do_add_request(desc, subreq);
+		if (size == subreq_size) {
+			/* We successfully submitted a request */
+			if (subreq == req)
+				break;
+			req->wb_pgbase += size;
+			req->wb_bytes -= size;
+			req->wb_offset += size;
+			subreq_size = req->wb_bytes;
+			subreq = req;
+			continue;
+		}
+		if (WARN_ON_ONCE(subreq != req)) {
+			nfs_page_group_unlock(req);
+			nfs_pageio_cleanup_request(desc, subreq);
+			subreq = req;
+			subreq_size = req->wb_bytes;
+			nfs_page_group_lock(req);
+		}
+		if (!size) {
+			/* Can't coalesce any more, so do I/O */
+			nfs_page_group_unlock(req);
+			desc->pg_moreio = 1;
+			nfs_pageio_doio(desc);
+			if (desc->pg_error < 0 || mirror->pg_recoalesce)
+				return 0;
+			/* retry add_request for this subreq */
+			nfs_page_group_lock(req);
+			continue;
+		}
+		subreq = nfs_create_subreq(req, req->wb_pgbase,
+				req->wb_offset, size);
+		if (IS_ERR(subreq))
+			goto err_ptr;
+		subreq_size = size;
+	}
+
+	nfs_page_group_unlock(req);
+	return 1;
+err_ptr:
+	desc->pg_error = PTR_ERR(subreq);
+	nfs_page_group_unlock(req);
+	return 0;
+}
+
+static int nfs_do_recoalesce(struct nfs_pageio_descriptor *desc)
+{
+	struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
+	LIST_HEAD(head);
+
+	do {
+		list_splice_init(&mirror->pg_list, &head);
+		mirror->pg_count = 0;
+		mirror->pg_base = 0;
+		mirror->pg_recoalesce = 0;
+
+		while (!list_empty(&head)) {
+			struct nfs_page *req;
+
+			req = list_first_entry(&head, struct nfs_page, wb_list);
+			if (__nfs_pageio_add_request(desc, req))
+				continue;
+			if (desc->pg_error < 0) {
+				list_splice_tail(&head, &mirror->pg_list);
+				mirror->pg_recoalesce = 1;
+				return 0;
+			}
+			break;
+		}
+	} while (mirror->pg_recoalesce);
+	return 1;
+}
+
+static int nfs_pageio_add_request_mirror(struct nfs_pageio_descriptor *desc,
+		struct nfs_page *req)
+{
+	int ret;
+
+	do {
+		ret = __nfs_pageio_add_request(desc, req);
+		if (ret)
+			break;
+		if (desc->pg_error < 0)
+			break;
+		ret = nfs_do_recoalesce(desc);
+	} while (ret);
+
+	return ret;
+}
+
+static void nfs_pageio_error_cleanup(struct nfs_pageio_descriptor *desc)
+{
+	u32 midx;
+	struct nfs_pgio_mirror *mirror;
+
+	if (!desc->pg_error)
+		return;
+
+	for (midx = 0; midx < desc->pg_mirror_count; midx++) {
+		mirror = nfs_pgio_get_mirror(desc, midx);
+		desc->pg_completion_ops->error_cleanup(&mirror->pg_list,
+				desc->pg_error);
+	}
+}
+
+int nfs_pageio_add_request(struct nfs_pageio_descriptor *desc,
+			   struct nfs_page *req)
+{
+	u32 midx;
+	unsigned int pgbase, offset, bytes;
+	struct nfs_page *dupreq;
+
+	pgbase = req->wb_pgbase;
+	offset = req->wb_offset;
+	bytes = req->wb_bytes;
+
+	nfs_pageio_setup_mirroring(desc, req);
+	if (desc->pg_error < 0)
+		goto out_failed;
+
+	/* Create the mirror instances first, and fire them off */
+	for (midx = 1; midx < desc->pg_mirror_count; midx++) {
+		nfs_page_group_lock(req);
+
+		dupreq = nfs_create_subreq(req,
+				pgbase, offset, bytes);
+
+		nfs_page_group_unlock(req);
+		if (IS_ERR(dupreq)) {
+			desc->pg_error = PTR_ERR(dupreq);
+			goto out_failed;
+		}
+
+		nfs_pgio_set_current_mirror(desc, midx);
+		if (!nfs_pageio_add_request_mirror(desc, dupreq))
+			goto out_cleanup_subreq;
+	}
+
+	nfs_pgio_set_current_mirror(desc, 0);
+	if (!nfs_pageio_add_request_mirror(desc, req))
+		goto out_failed;
+
+	return 1;
+
+out_cleanup_subreq:
+	nfs_pageio_cleanup_request(desc, dupreq);
+out_failed:
+	nfs_pageio_error_cleanup(desc);
+	return 0;
+}
+
+/*
+ * nfs_pageio_complete_mirror - Complete I/O on the current mirror of an
+ *				nfs_pageio_descriptor
+ * @desc: pointer to io descriptor
+ * @mirror_idx: pointer to mirror index
+ */
+static void nfs_pageio_complete_mirror(struct nfs_pageio_descriptor *desc,
+				       u32 mirror_idx)
+{
+	struct nfs_pgio_mirror *mirror;
+	u32 restore_idx;
+
+	restore_idx = nfs_pgio_set_current_mirror(desc, mirror_idx);
+	mirror = nfs_pgio_current_mirror(desc);
+
+	for (;;) {
+		nfs_pageio_doio(desc);
+		if (desc->pg_error < 0 || !mirror->pg_recoalesce)
+			break;
+		if (!nfs_do_recoalesce(desc))
+			break;
+	}
+	nfs_pgio_set_current_mirror(desc, restore_idx);
+}
+
+/*
+ * nfs_pageio_resend - Transfer requests to new descriptor and resend
+ * @hdr - the pgio header to move request from
+ * @desc - the pageio descriptor to add requests to
+ *
+ * Try to move each request (nfs_page) from @hdr to @desc then attempt
+ * to send them.
+ *
+ * Returns 0 on success and < 0 on error.
+ */
+int nfs_pageio_resend(struct nfs_pageio_descriptor *desc,
+		      struct nfs_pgio_header *hdr)
+{
+	LIST_HEAD(pages);
+
+	desc->pg_io_completion = hdr->io_completion;
+	desc->pg_dreq = hdr->dreq;
+	list_splice_init(&hdr->pages, &pages);
+	while (!list_empty(&pages)) {
+		struct nfs_page *req = nfs_list_entry(pages.next);
+
+		if (!nfs_pageio_add_request(desc, req))
+			break;
+	}
+	nfs_pageio_complete(desc);
+	if (!list_empty(&pages)) {
+		int err = desc->pg_error < 0 ? desc->pg_error : -EIO;
+		hdr->completion_ops->error_cleanup(&pages, err);
+		nfs_set_pgio_error(hdr, err, hdr->io_start);
+		return err;
+	}
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nfs_pageio_resend);
+
+/**
+ * nfs_pageio_complete - Complete I/O then cleanup an nfs_pageio_descriptor
+ * @desc: pointer to io descriptor
+ */
+void nfs_pageio_complete(struct nfs_pageio_descriptor *desc)
+{
+	u32 midx;
+
+	for (midx = 0; midx < desc->pg_mirror_count; midx++)
+		nfs_pageio_complete_mirror(desc, midx);
+
+	if (desc->pg_error < 0)
+		nfs_pageio_error_cleanup(desc);
+	if (desc->pg_ops->pg_cleanup)
+		desc->pg_ops->pg_cleanup(desc);
+	nfs_pageio_cleanup_mirroring(desc);
+}
+
+/**
+ * nfs_pageio_cond_complete - Conditional I/O completion
+ * @desc: pointer to io descriptor
+ * @index: page index
+ *
+ * It is important to ensure that processes don't try to take locks
+ * on non-contiguous ranges of pages as that might deadlock. This
+ * function should be called before attempting to wait on a locked
+ * nfs_page. It will complete the I/O if the page index 'index'
+ * is not contiguous with the existing list of pages in 'desc'.
+ */
+void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *desc, pgoff_t index)
+{
+	struct nfs_pgio_mirror *mirror;
+	struct nfs_page *prev;
+	u32 midx;
+
+	for (midx = 0; midx < desc->pg_mirror_count; midx++) {
+		mirror = nfs_pgio_get_mirror(desc, midx);
+		if (!list_empty(&mirror->pg_list)) {
+			prev = nfs_list_entry(mirror->pg_list.prev);
+			if (index != prev->wb_index + 1) {
+				nfs_pageio_complete(desc);
+				break;
+			}
+		}
+	}
+}
+
+/*
+ * nfs_pageio_stop_mirroring - stop using mirroring (set mirror count to 1)
+ */
+void nfs_pageio_stop_mirroring(struct nfs_pageio_descriptor *pgio)
+{
+	nfs_pageio_complete(pgio);
+}
+
+int __init nfs_init_nfspagecache(void)
+{
+	nfs_page_cachep = kmem_cache_create("nfs_page",
+					    sizeof(struct nfs_page),
+					    0, SLAB_HWCACHE_ALIGN,
+					    NULL);
+	if (nfs_page_cachep == NULL)
+		return -ENOMEM;
+
+	return 0;
+}
+
+void nfs_destroy_nfspagecache(void)
+{
+	kmem_cache_destroy(nfs_page_cachep);
+}
+
+static const struct rpc_call_ops nfs_pgio_common_ops = {
+	.rpc_call_prepare = nfs_pgio_prepare,
+	.rpc_call_done = nfs_pgio_result,
+	.rpc_release = nfs_pgio_release,
+};
+
+const struct nfs_pageio_ops nfs_pgio_rw_ops = {
+	.pg_test = nfs_generic_pg_test,
+	.pg_doio = nfs_generic_pg_pgios,
+};
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
new file mode 100644
index 000000000..ed6a3ed83
--- /dev/null
+++ b/fs/nfs/pnfs.c
@@ -0,0 +1,3360 @@
+/*
+ *  pNFS functions to call and manage layout drivers.
+ *
+ *  Copyright (c) 2002 [year of first publication]
+ *  The Regents of the University of Michigan
+ *  All Rights Reserved
+ *
+ *  Dean Hildebrand <dhildebz@umich.edu>
+ *
+ *  Permission is granted to use, copy, create derivative works, and
+ *  redistribute this software and such derivative works for any purpose,
+ *  so long as the name of the University of Michigan is not used in
+ *  any advertising or publicity pertaining to the use or distribution
+ *  of this software without specific, written prior authorization. If
+ *  the above copyright notice or any other identification of the
+ *  University of Michigan is included in any copy of any portion of
+ *  this software, then the disclaimer below must also be included.
+ *
+ *  This software is provided as is, without representation or warranty
+ *  of any kind either express or implied, including without limitation
+ *  the implied warranties of merchantability, fitness for a particular
+ *  purpose, or noninfringement.  The Regents of the University of
+ *  Michigan shall not be liable for any damages, including special,
+ *  indirect, incidental, or consequential damages, with respect to any
+ *  claim arising out of or in connection with the use of the software,
+ *  even if it has been or is hereafter advised of the possibility of
+ *  such damages.
+ */
+
+#include <linux/nfs_fs.h>
+#include <linux/nfs_page.h>
+#include <linux/module.h>
+#include <linux/sort.h>
+#include "internal.h"
+#include "pnfs.h"
+#include "iostat.h"
+#include "nfs4trace.h"
+#include "delegation.h"
+#include "nfs42.h"
+#include "nfs4_fs.h"
+
+#define NFSDBG_FACILITY		NFSDBG_PNFS
+#define PNFS_LAYOUTGET_RETRY_TIMEOUT (120*HZ)
+
+/* Locking:
+ *
+ * pnfs_spinlock:
+ *      protects pnfs_modules_tbl.
+ */
+static DEFINE_SPINLOCK(pnfs_spinlock);
+
+/*
+ * pnfs_modules_tbl holds all pnfs modules
+ */
+static LIST_HEAD(pnfs_modules_tbl);
+
+static void pnfs_layoutreturn_before_put_layout_hdr(struct pnfs_layout_hdr *lo);
+static void pnfs_free_returned_lsegs(struct pnfs_layout_hdr *lo,
+		struct list_head *free_me,
+		const struct pnfs_layout_range *range,
+		u32 seq);
+static bool pnfs_lseg_dec_and_remove_zero(struct pnfs_layout_segment *lseg,
+		                struct list_head *tmp_list);
+
+/* Return the registered pnfs layout driver module matching given id */
+static struct pnfs_layoutdriver_type *
+find_pnfs_driver_locked(u32 id)
+{
+	struct pnfs_layoutdriver_type *local;
+
+	list_for_each_entry(local, &pnfs_modules_tbl, pnfs_tblid)
+		if (local->id == id)
+			goto out;
+	local = NULL;
+out:
+	dprintk("%s: Searching for id %u, found %p\n", __func__, id, local);
+	return local;
+}
+
+static struct pnfs_layoutdriver_type *
+find_pnfs_driver(u32 id)
+{
+	struct pnfs_layoutdriver_type *local;
+
+	spin_lock(&pnfs_spinlock);
+	local = find_pnfs_driver_locked(id);
+	if (local != NULL && !try_module_get(local->owner)) {
+		dprintk("%s: Could not grab reference on module\n", __func__);
+		local = NULL;
+	}
+	spin_unlock(&pnfs_spinlock);
+	return local;
+}
+
+const struct pnfs_layoutdriver_type *pnfs_find_layoutdriver(u32 id)
+{
+	return find_pnfs_driver(id);
+}
+
+void pnfs_put_layoutdriver(const struct pnfs_layoutdriver_type *ld)
+{
+	if (ld)
+		module_put(ld->owner);
+}
+
+void
+unset_pnfs_layoutdriver(struct nfs_server *nfss)
+{
+	if (nfss->pnfs_curr_ld) {
+		if (nfss->pnfs_curr_ld->clear_layoutdriver)
+			nfss->pnfs_curr_ld->clear_layoutdriver(nfss);
+		/* Decrement the MDS count. Purge the deviceid cache if zero */
+		if (atomic_dec_and_test(&nfss->nfs_client->cl_mds_count))
+			nfs4_deviceid_purge_client(nfss->nfs_client);
+		module_put(nfss->pnfs_curr_ld->owner);
+	}
+	nfss->pnfs_curr_ld = NULL;
+}
+
+/*
+ * When the server sends a list of layout types, we choose one in the order
+ * given in the list below.
+ *
+ * FIXME: should this list be configurable in some fashion? module param?
+ * 	  mount option? something else?
+ */
+static const u32 ld_prefs[] = {
+	LAYOUT_SCSI,
+	LAYOUT_BLOCK_VOLUME,
+	LAYOUT_OSD2_OBJECTS,
+	LAYOUT_FLEX_FILES,
+	LAYOUT_NFSV4_1_FILES,
+	0
+};
+
+static int
+ld_cmp(const void *e1, const void *e2)
+{
+	u32 ld1 = *((u32 *)e1);
+	u32 ld2 = *((u32 *)e2);
+	int i;
+
+	for (i = 0; ld_prefs[i] != 0; i++) {
+		if (ld1 == ld_prefs[i])
+			return -1;
+
+		if (ld2 == ld_prefs[i])
+			return 1;
+	}
+	return 0;
+}
+
+/*
+ * Try to set the server's pnfs module to the pnfs layout type specified by id.
+ * Currently only one pNFS layout driver per filesystem is supported.
+ *
+ * @ids array of layout types supported by MDS.
+ */
+void
+set_pnfs_layoutdriver(struct nfs_server *server, const struct nfs_fh *mntfh,
+		      struct nfs_fsinfo *fsinfo)
+{
+	struct pnfs_layoutdriver_type *ld_type = NULL;
+	u32 id;
+	int i;
+
+	if (fsinfo->nlayouttypes == 0)
+		goto out_no_driver;
+	if (!(server->nfs_client->cl_exchange_flags &
+		 (EXCHGID4_FLAG_USE_NON_PNFS | EXCHGID4_FLAG_USE_PNFS_MDS))) {
+		printk(KERN_ERR "NFS: %s: cl_exchange_flags 0x%x\n",
+			__func__, server->nfs_client->cl_exchange_flags);
+		goto out_no_driver;
+	}
+
+	sort(fsinfo->layouttype, fsinfo->nlayouttypes,
+		sizeof(*fsinfo->layouttype), ld_cmp, NULL);
+
+	for (i = 0; i < fsinfo->nlayouttypes; i++) {
+		id = fsinfo->layouttype[i];
+		ld_type = find_pnfs_driver(id);
+		if (!ld_type) {
+			request_module("%s-%u", LAYOUT_NFSV4_1_MODULE_PREFIX,
+					id);
+			ld_type = find_pnfs_driver(id);
+		}
+		if (ld_type)
+			break;
+	}
+
+	if (!ld_type) {
+		dprintk("%s: No pNFS module found!\n", __func__);
+		goto out_no_driver;
+	}
+
+	server->pnfs_curr_ld = ld_type;
+	if (ld_type->set_layoutdriver
+	    && ld_type->set_layoutdriver(server, mntfh)) {
+		printk(KERN_ERR "NFS: %s: Error initializing pNFS layout "
+			"driver %u.\n", __func__, id);
+		module_put(ld_type->owner);
+		goto out_no_driver;
+	}
+	/* Bump the MDS count */
+	atomic_inc(&server->nfs_client->cl_mds_count);
+
+	dprintk("%s: pNFS module for %u set\n", __func__, id);
+	return;
+
+out_no_driver:
+	dprintk("%s: Using NFSv4 I/O\n", __func__);
+	server->pnfs_curr_ld = NULL;
+}
+
+int
+pnfs_register_layoutdriver(struct pnfs_layoutdriver_type *ld_type)
+{
+	int status = -EINVAL;
+	struct pnfs_layoutdriver_type *tmp;
+
+	if (ld_type->id == 0) {
+		printk(KERN_ERR "NFS: %s id 0 is reserved\n", __func__);
+		return status;
+	}
+	if (!ld_type->alloc_lseg || !ld_type->free_lseg) {
+		printk(KERN_ERR "NFS: %s Layout driver must provide "
+		       "alloc_lseg and free_lseg.\n", __func__);
+		return status;
+	}
+
+	spin_lock(&pnfs_spinlock);
+	tmp = find_pnfs_driver_locked(ld_type->id);
+	if (!tmp) {
+		list_add(&ld_type->pnfs_tblid, &pnfs_modules_tbl);
+		status = 0;
+		dprintk("%s Registering id:%u name:%s\n", __func__, ld_type->id,
+			ld_type->name);
+	} else {
+		printk(KERN_ERR "NFS: %s Module with id %d already loaded!\n",
+			__func__, ld_type->id);
+	}
+	spin_unlock(&pnfs_spinlock);
+
+	return status;
+}
+EXPORT_SYMBOL_GPL(pnfs_register_layoutdriver);
+
+void
+pnfs_unregister_layoutdriver(struct pnfs_layoutdriver_type *ld_type)
+{
+	dprintk("%s Deregistering id:%u\n", __func__, ld_type->id);
+	spin_lock(&pnfs_spinlock);
+	list_del(&ld_type->pnfs_tblid);
+	spin_unlock(&pnfs_spinlock);
+}
+EXPORT_SYMBOL_GPL(pnfs_unregister_layoutdriver);
+
+/*
+ * pNFS client layout cache
+ */
+
+/* Need to hold i_lock if caller does not already hold reference */
+void
+pnfs_get_layout_hdr(struct pnfs_layout_hdr *lo)
+{
+	refcount_inc(&lo->plh_refcount);
+}
+
+static struct pnfs_layout_hdr *
+pnfs_alloc_layout_hdr(struct inode *ino, gfp_t gfp_flags)
+{
+	struct pnfs_layoutdriver_type *ld = NFS_SERVER(ino)->pnfs_curr_ld;
+	return ld->alloc_layout_hdr(ino, gfp_flags);
+}
+
+static void
+pnfs_free_layout_hdr(struct pnfs_layout_hdr *lo)
+{
+	struct nfs_server *server = NFS_SERVER(lo->plh_inode);
+	struct pnfs_layoutdriver_type *ld = server->pnfs_curr_ld;
+
+	if (test_and_clear_bit(NFS_LAYOUT_HASHED, &lo->plh_flags)) {
+		struct nfs_client *clp = server->nfs_client;
+
+		spin_lock(&clp->cl_lock);
+		list_del_rcu(&lo->plh_layouts);
+		spin_unlock(&clp->cl_lock);
+	}
+	put_cred(lo->plh_lc_cred);
+	return ld->free_layout_hdr(lo);
+}
+
+static void
+pnfs_detach_layout_hdr(struct pnfs_layout_hdr *lo)
+{
+	struct nfs_inode *nfsi = NFS_I(lo->plh_inode);
+	dprintk("%s: freeing layout cache %p\n", __func__, lo);
+	nfsi->layout = NULL;
+	/* Reset MDS Threshold I/O counters */
+	nfsi->write_io = 0;
+	nfsi->read_io = 0;
+}
+
+void
+pnfs_put_layout_hdr(struct pnfs_layout_hdr *lo)
+{
+	struct inode *inode;
+	unsigned long i_state;
+
+	if (!lo)
+		return;
+	inode = lo->plh_inode;
+	pnfs_layoutreturn_before_put_layout_hdr(lo);
+
+	if (refcount_dec_and_lock(&lo->plh_refcount, &inode->i_lock)) {
+		if (!list_empty(&lo->plh_segs))
+			WARN_ONCE(1, "NFS: BUG unfreed layout segments.\n");
+		pnfs_detach_layout_hdr(lo);
+		i_state = inode->i_state;
+		spin_unlock(&inode->i_lock);
+		pnfs_free_layout_hdr(lo);
+		/* Notify pnfs_destroy_layout_final() that we're done */
+		if (i_state & (I_FREEING | I_CLEAR))
+			wake_up_var(lo);
+	}
+}
+
+static struct inode *
+pnfs_grab_inode_layout_hdr(struct pnfs_layout_hdr *lo)
+{
+	struct inode *inode = igrab(lo->plh_inode);
+	if (inode)
+		return inode;
+	set_bit(NFS_LAYOUT_INODE_FREEING, &lo->plh_flags);
+	return NULL;
+}
+
+/*
+ * Compare 2 layout stateid sequence ids, to see which is newer,
+ * taking into account wraparound issues.
+ */
+static bool pnfs_seqid_is_newer(u32 s1, u32 s2)
+{
+	return (s32)(s1 - s2) > 0;
+}
+
+static void pnfs_barrier_update(struct pnfs_layout_hdr *lo, u32 newseq)
+{
+	if (pnfs_seqid_is_newer(newseq, lo->plh_barrier) || !lo->plh_barrier)
+		lo->plh_barrier = newseq;
+}
+
+static void
+pnfs_set_plh_return_info(struct pnfs_layout_hdr *lo, enum pnfs_iomode iomode,
+			 u32 seq)
+{
+	if (lo->plh_return_iomode != 0 && lo->plh_return_iomode != iomode)
+		iomode = IOMODE_ANY;
+	lo->plh_return_iomode = iomode;
+	set_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags);
+	/*
+	 * We must set lo->plh_return_seq to avoid livelocks with
+	 * pnfs_layout_need_return()
+	 */
+	if (seq == 0)
+		seq = be32_to_cpu(lo->plh_stateid.seqid);
+	if (!lo->plh_return_seq || pnfs_seqid_is_newer(seq, lo->plh_return_seq))
+		lo->plh_return_seq = seq;
+	pnfs_barrier_update(lo, seq);
+}
+
+static void
+pnfs_clear_layoutreturn_info(struct pnfs_layout_hdr *lo)
+{
+	struct pnfs_layout_segment *lseg;
+	lo->plh_return_iomode = 0;
+	lo->plh_return_seq = 0;
+	clear_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags);
+	list_for_each_entry(lseg, &lo->plh_segs, pls_list) {
+		if (!test_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags))
+			continue;
+		pnfs_set_plh_return_info(lo, lseg->pls_range.iomode, 0);
+	}
+}
+
+static void pnfs_clear_layoutreturn_waitbit(struct pnfs_layout_hdr *lo)
+{
+	clear_bit_unlock(NFS_LAYOUT_RETURN, &lo->plh_flags);
+	clear_bit(NFS_LAYOUT_RETURN_LOCK, &lo->plh_flags);
+	smp_mb__after_atomic();
+	wake_up_bit(&lo->plh_flags, NFS_LAYOUT_RETURN);
+	rpc_wake_up(&NFS_SERVER(lo->plh_inode)->roc_rpcwaitq);
+}
+
+static void
+pnfs_clear_lseg_state(struct pnfs_layout_segment *lseg,
+		struct list_head *free_me)
+{
+	clear_bit(NFS_LSEG_ROC, &lseg->pls_flags);
+	clear_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags);
+	if (test_and_clear_bit(NFS_LSEG_VALID, &lseg->pls_flags))
+		pnfs_lseg_dec_and_remove_zero(lseg, free_me);
+	if (test_and_clear_bit(NFS_LSEG_LAYOUTCOMMIT, &lseg->pls_flags))
+		pnfs_lseg_dec_and_remove_zero(lseg, free_me);
+}
+
+/*
+ * Update the seqid of a layout stateid after receiving
+ * NFS4ERR_OLD_STATEID
+ */
+bool nfs4_layout_refresh_old_stateid(nfs4_stateid *dst,
+		struct pnfs_layout_range *dst_range,
+		struct inode *inode)
+{
+	struct pnfs_layout_hdr *lo;
+	struct pnfs_layout_range range = {
+		.iomode = IOMODE_ANY,
+		.offset = 0,
+		.length = NFS4_MAX_UINT64,
+	};
+	bool ret = false;
+	LIST_HEAD(head);
+	int err;
+
+	spin_lock(&inode->i_lock);
+	lo = NFS_I(inode)->layout;
+	if (lo &&  pnfs_layout_is_valid(lo) &&
+	    nfs4_stateid_match_other(dst, &lo->plh_stateid)) {
+		/* Is our call using the most recent seqid? If so, bump it */
+		if (!nfs4_stateid_is_newer(&lo->plh_stateid, dst)) {
+			nfs4_stateid_seqid_inc(dst);
+			ret = true;
+			goto out;
+		}
+		/* Try to update the seqid to the most recent */
+		err = pnfs_mark_matching_lsegs_return(lo, &head, &range, 0);
+		if (err != -EBUSY) {
+			dst->seqid = lo->plh_stateid.seqid;
+			*dst_range = range;
+			ret = true;
+		}
+	}
+out:
+	spin_unlock(&inode->i_lock);
+	pnfs_free_lseg_list(&head);
+	return ret;
+}
+
+/*
+ * Mark a pnfs_layout_hdr and all associated layout segments as invalid
+ *
+ * In order to continue using the pnfs_layout_hdr, a full recovery
+ * is required.
+ * Note that caller must hold inode->i_lock.
+ */
+int
+pnfs_mark_layout_stateid_invalid(struct pnfs_layout_hdr *lo,
+		struct list_head *lseg_list)
+{
+	struct pnfs_layout_range range = {
+		.iomode = IOMODE_ANY,
+		.offset = 0,
+		.length = NFS4_MAX_UINT64,
+	};
+	struct pnfs_layout_segment *lseg, *next;
+
+	set_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags);
+	list_for_each_entry_safe(lseg, next, &lo->plh_segs, pls_list)
+		pnfs_clear_lseg_state(lseg, lseg_list);
+	pnfs_clear_layoutreturn_info(lo);
+	pnfs_free_returned_lsegs(lo, lseg_list, &range, 0);
+	set_bit(NFS_LAYOUT_DRAIN, &lo->plh_flags);
+	if (test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags) &&
+	    !test_and_set_bit(NFS_LAYOUT_RETURN_LOCK, &lo->plh_flags))
+		pnfs_clear_layoutreturn_waitbit(lo);
+	return !list_empty(&lo->plh_segs);
+}
+
+static int
+pnfs_iomode_to_fail_bit(u32 iomode)
+{
+	return iomode == IOMODE_RW ?
+		NFS_LAYOUT_RW_FAILED : NFS_LAYOUT_RO_FAILED;
+}
+
+static void
+pnfs_layout_set_fail_bit(struct pnfs_layout_hdr *lo, int fail_bit)
+{
+	lo->plh_retry_timestamp = jiffies;
+	if (!test_and_set_bit(fail_bit, &lo->plh_flags))
+		refcount_inc(&lo->plh_refcount);
+}
+
+static void
+pnfs_layout_clear_fail_bit(struct pnfs_layout_hdr *lo, int fail_bit)
+{
+	if (test_and_clear_bit(fail_bit, &lo->plh_flags))
+		refcount_dec(&lo->plh_refcount);
+}
+
+static void
+pnfs_layout_io_set_failed(struct pnfs_layout_hdr *lo, u32 iomode)
+{
+	struct inode *inode = lo->plh_inode;
+	struct pnfs_layout_range range = {
+		.iomode = iomode,
+		.offset = 0,
+		.length = NFS4_MAX_UINT64,
+	};
+	LIST_HEAD(head);
+
+	spin_lock(&inode->i_lock);
+	pnfs_layout_set_fail_bit(lo, pnfs_iomode_to_fail_bit(iomode));
+	pnfs_mark_matching_lsegs_invalid(lo, &head, &range, 0);
+	spin_unlock(&inode->i_lock);
+	pnfs_free_lseg_list(&head);
+	dprintk("%s Setting layout IOMODE_%s fail bit\n", __func__,
+			iomode == IOMODE_RW ?  "RW" : "READ");
+}
+
+static bool
+pnfs_layout_io_test_failed(struct pnfs_layout_hdr *lo, u32 iomode)
+{
+	unsigned long start, end;
+	int fail_bit = pnfs_iomode_to_fail_bit(iomode);
+
+	if (test_bit(fail_bit, &lo->plh_flags) == 0)
+		return false;
+	end = jiffies;
+	start = end - PNFS_LAYOUTGET_RETRY_TIMEOUT;
+	if (!time_in_range(lo->plh_retry_timestamp, start, end)) {
+		/* It is time to retry the failed layoutgets */
+		pnfs_layout_clear_fail_bit(lo, fail_bit);
+		return false;
+	}
+	return true;
+}
+
+static void
+pnfs_init_lseg(struct pnfs_layout_hdr *lo, struct pnfs_layout_segment *lseg,
+		const struct pnfs_layout_range *range,
+		const nfs4_stateid *stateid)
+{
+	INIT_LIST_HEAD(&lseg->pls_list);
+	INIT_LIST_HEAD(&lseg->pls_lc_list);
+	INIT_LIST_HEAD(&lseg->pls_commits);
+	refcount_set(&lseg->pls_refcount, 1);
+	set_bit(NFS_LSEG_VALID, &lseg->pls_flags);
+	lseg->pls_layout = lo;
+	lseg->pls_range = *range;
+	lseg->pls_seq = be32_to_cpu(stateid->seqid);
+}
+
+static void pnfs_free_lseg(struct pnfs_layout_segment *lseg)
+{
+	if (lseg != NULL) {
+		struct inode *inode = lseg->pls_layout->plh_inode;
+		NFS_SERVER(inode)->pnfs_curr_ld->free_lseg(lseg);
+	}
+}
+
+static void
+pnfs_layout_remove_lseg(struct pnfs_layout_hdr *lo,
+		struct pnfs_layout_segment *lseg)
+{
+	WARN_ON(test_bit(NFS_LSEG_VALID, &lseg->pls_flags));
+	list_del_init(&lseg->pls_list);
+	/* Matched by pnfs_get_layout_hdr in pnfs_layout_insert_lseg */
+	refcount_dec(&lo->plh_refcount);
+	if (test_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags))
+		return;
+	if (list_empty(&lo->plh_segs) &&
+	    !test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags) &&
+	    !test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags)) {
+		if (atomic_read(&lo->plh_outstanding) == 0)
+			set_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags);
+		clear_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags);
+	}
+}
+
+static bool
+pnfs_cache_lseg_for_layoutreturn(struct pnfs_layout_hdr *lo,
+		struct pnfs_layout_segment *lseg)
+{
+	if (test_and_clear_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags) &&
+	    pnfs_layout_is_valid(lo)) {
+		pnfs_set_plh_return_info(lo, lseg->pls_range.iomode, 0);
+		list_move_tail(&lseg->pls_list, &lo->plh_return_segs);
+		return true;
+	}
+	return false;
+}
+
+void
+pnfs_put_lseg(struct pnfs_layout_segment *lseg)
+{
+	struct pnfs_layout_hdr *lo;
+	struct inode *inode;
+
+	if (!lseg)
+		return;
+
+	dprintk("%s: lseg %p ref %d valid %d\n", __func__, lseg,
+		refcount_read(&lseg->pls_refcount),
+		test_bit(NFS_LSEG_VALID, &lseg->pls_flags));
+
+	lo = lseg->pls_layout;
+	inode = lo->plh_inode;
+
+	if (refcount_dec_and_lock(&lseg->pls_refcount, &inode->i_lock)) {
+		if (test_bit(NFS_LSEG_VALID, &lseg->pls_flags)) {
+			spin_unlock(&inode->i_lock);
+			return;
+		}
+		pnfs_get_layout_hdr(lo);
+		pnfs_layout_remove_lseg(lo, lseg);
+		if (pnfs_cache_lseg_for_layoutreturn(lo, lseg))
+			lseg = NULL;
+		spin_unlock(&inode->i_lock);
+		pnfs_free_lseg(lseg);
+		pnfs_put_layout_hdr(lo);
+	}
+}
+EXPORT_SYMBOL_GPL(pnfs_put_lseg);
+
+/*
+ * is l2 fully contained in l1?
+ *   start1                             end1
+ *   [----------------------------------)
+ *           start2           end2
+ *           [----------------)
+ */
+static bool
+pnfs_lseg_range_contained(const struct pnfs_layout_range *l1,
+		 const struct pnfs_layout_range *l2)
+{
+	u64 start1 = l1->offset;
+	u64 end1 = pnfs_end_offset(start1, l1->length);
+	u64 start2 = l2->offset;
+	u64 end2 = pnfs_end_offset(start2, l2->length);
+
+	return (start1 <= start2) && (end1 >= end2);
+}
+
+static bool pnfs_lseg_dec_and_remove_zero(struct pnfs_layout_segment *lseg,
+		struct list_head *tmp_list)
+{
+	if (!refcount_dec_and_test(&lseg->pls_refcount))
+		return false;
+	pnfs_layout_remove_lseg(lseg->pls_layout, lseg);
+	list_add(&lseg->pls_list, tmp_list);
+	return true;
+}
+
+/* Returns 1 if lseg is removed from list, 0 otherwise */
+static int mark_lseg_invalid(struct pnfs_layout_segment *lseg,
+			     struct list_head *tmp_list)
+{
+	int rv = 0;
+
+	if (test_and_clear_bit(NFS_LSEG_VALID, &lseg->pls_flags)) {
+		/* Remove the reference keeping the lseg in the
+		 * list.  It will now be removed when all
+		 * outstanding io is finished.
+		 */
+		dprintk("%s: lseg %p ref %d\n", __func__, lseg,
+			refcount_read(&lseg->pls_refcount));
+		if (pnfs_lseg_dec_and_remove_zero(lseg, tmp_list))
+			rv = 1;
+	}
+	return rv;
+}
+
+static bool
+pnfs_should_free_range(const struct pnfs_layout_range *lseg_range,
+		 const struct pnfs_layout_range *recall_range)
+{
+	return (recall_range->iomode == IOMODE_ANY ||
+		lseg_range->iomode == recall_range->iomode) &&
+	       pnfs_lseg_range_intersecting(lseg_range, recall_range);
+}
+
+static bool
+pnfs_match_lseg_recall(const struct pnfs_layout_segment *lseg,
+		const struct pnfs_layout_range *recall_range,
+		u32 seq)
+{
+	if (seq != 0 && pnfs_seqid_is_newer(lseg->pls_seq, seq))
+		return false;
+	if (recall_range == NULL)
+		return true;
+	return pnfs_should_free_range(&lseg->pls_range, recall_range);
+}
+
+/**
+ * pnfs_mark_matching_lsegs_invalid - tear down lsegs or mark them for later
+ * @lo: layout header containing the lsegs
+ * @tmp_list: list head where doomed lsegs should go
+ * @recall_range: optional recall range argument to match (may be NULL)
+ * @seq: only invalidate lsegs obtained prior to this sequence (may be 0)
+ *
+ * Walk the list of lsegs in the layout header, and tear down any that should
+ * be destroyed. If "recall_range" is specified then the segment must match
+ * that range. If "seq" is non-zero, then only match segments that were handed
+ * out at or before that sequence.
+ *
+ * Returns number of matching invalid lsegs remaining in list after scanning
+ * it and purging them.
+ */
+int
+pnfs_mark_matching_lsegs_invalid(struct pnfs_layout_hdr *lo,
+			    struct list_head *tmp_list,
+			    const struct pnfs_layout_range *recall_range,
+			    u32 seq)
+{
+	struct pnfs_layout_segment *lseg, *next;
+	int remaining = 0;
+
+	dprintk("%s:Begin lo %p\n", __func__, lo);
+
+	if (list_empty(&lo->plh_segs))
+		return 0;
+	list_for_each_entry_safe(lseg, next, &lo->plh_segs, pls_list)
+		if (pnfs_match_lseg_recall(lseg, recall_range, seq)) {
+			dprintk("%s: freeing lseg %p iomode %d seq %u "
+				"offset %llu length %llu\n", __func__,
+				lseg, lseg->pls_range.iomode, lseg->pls_seq,
+				lseg->pls_range.offset, lseg->pls_range.length);
+			if (!mark_lseg_invalid(lseg, tmp_list))
+				remaining++;
+		}
+	dprintk("%s:Return %i\n", __func__, remaining);
+	return remaining;
+}
+
+static void
+pnfs_free_returned_lsegs(struct pnfs_layout_hdr *lo,
+		struct list_head *free_me,
+		const struct pnfs_layout_range *range,
+		u32 seq)
+{
+	struct pnfs_layout_segment *lseg, *next;
+
+	list_for_each_entry_safe(lseg, next, &lo->plh_return_segs, pls_list) {
+		if (pnfs_match_lseg_recall(lseg, range, seq))
+			list_move_tail(&lseg->pls_list, free_me);
+	}
+}
+
+/* note free_me must contain lsegs from a single layout_hdr */
+void
+pnfs_free_lseg_list(struct list_head *free_me)
+{
+	struct pnfs_layout_segment *lseg, *tmp;
+
+	if (list_empty(free_me))
+		return;
+
+	list_for_each_entry_safe(lseg, tmp, free_me, pls_list) {
+		list_del(&lseg->pls_list);
+		pnfs_free_lseg(lseg);
+	}
+}
+
+static struct pnfs_layout_hdr *__pnfs_destroy_layout(struct nfs_inode *nfsi)
+{
+	struct pnfs_layout_hdr *lo;
+	LIST_HEAD(tmp_list);
+
+	spin_lock(&nfsi->vfs_inode.i_lock);
+	lo = nfsi->layout;
+	if (lo) {
+		pnfs_get_layout_hdr(lo);
+		pnfs_mark_layout_stateid_invalid(lo, &tmp_list);
+		pnfs_layout_clear_fail_bit(lo, NFS_LAYOUT_RO_FAILED);
+		pnfs_layout_clear_fail_bit(lo, NFS_LAYOUT_RW_FAILED);
+		spin_unlock(&nfsi->vfs_inode.i_lock);
+		pnfs_free_lseg_list(&tmp_list);
+		nfs_commit_inode(&nfsi->vfs_inode, 0);
+		pnfs_put_layout_hdr(lo);
+	} else
+		spin_unlock(&nfsi->vfs_inode.i_lock);
+	return lo;
+}
+
+void pnfs_destroy_layout(struct nfs_inode *nfsi)
+{
+	__pnfs_destroy_layout(nfsi);
+}
+EXPORT_SYMBOL_GPL(pnfs_destroy_layout);
+
+static bool pnfs_layout_removed(struct nfs_inode *nfsi,
+				struct pnfs_layout_hdr *lo)
+{
+	bool ret;
+
+	spin_lock(&nfsi->vfs_inode.i_lock);
+	ret = nfsi->layout != lo;
+	spin_unlock(&nfsi->vfs_inode.i_lock);
+	return ret;
+}
+
+void pnfs_destroy_layout_final(struct nfs_inode *nfsi)
+{
+	struct pnfs_layout_hdr *lo = __pnfs_destroy_layout(nfsi);
+
+	if (lo)
+		wait_var_event(lo, pnfs_layout_removed(nfsi, lo));
+}
+
+static bool
+pnfs_layout_add_bulk_destroy_list(struct inode *inode,
+		struct list_head *layout_list)
+{
+	struct pnfs_layout_hdr *lo;
+	bool ret = false;
+
+	spin_lock(&inode->i_lock);
+	lo = NFS_I(inode)->layout;
+	if (lo != NULL && list_empty(&lo->plh_bulk_destroy)) {
+		pnfs_get_layout_hdr(lo);
+		list_add(&lo->plh_bulk_destroy, layout_list);
+		ret = true;
+	}
+	spin_unlock(&inode->i_lock);
+	return ret;
+}
+
+/* Caller must hold rcu_read_lock and clp->cl_lock */
+static int
+pnfs_layout_bulk_destroy_byserver_locked(struct nfs_client *clp,
+		struct nfs_server *server,
+		struct list_head *layout_list)
+	__must_hold(&clp->cl_lock)
+	__must_hold(RCU)
+{
+	struct pnfs_layout_hdr *lo, *next;
+	struct inode *inode;
+
+	list_for_each_entry_safe(lo, next, &server->layouts, plh_layouts) {
+		if (test_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags) ||
+		    test_bit(NFS_LAYOUT_INODE_FREEING, &lo->plh_flags) ||
+		    !list_empty(&lo->plh_bulk_destroy))
+			continue;
+		/* If the sb is being destroyed, just bail */
+		if (!nfs_sb_active(server->super))
+			break;
+		inode = pnfs_grab_inode_layout_hdr(lo);
+		if (inode != NULL) {
+			if (test_and_clear_bit(NFS_LAYOUT_HASHED, &lo->plh_flags))
+				list_del_rcu(&lo->plh_layouts);
+			if (pnfs_layout_add_bulk_destroy_list(inode,
+						layout_list))
+				continue;
+			rcu_read_unlock();
+			spin_unlock(&clp->cl_lock);
+			iput(inode);
+		} else {
+			rcu_read_unlock();
+			spin_unlock(&clp->cl_lock);
+		}
+		nfs_sb_deactive(server->super);
+		spin_lock(&clp->cl_lock);
+		rcu_read_lock();
+		return -EAGAIN;
+	}
+	return 0;
+}
+
+static int
+pnfs_layout_free_bulk_destroy_list(struct list_head *layout_list,
+		bool is_bulk_recall)
+{
+	struct pnfs_layout_hdr *lo;
+	struct inode *inode;
+	LIST_HEAD(lseg_list);
+	int ret = 0;
+
+	while (!list_empty(layout_list)) {
+		lo = list_entry(layout_list->next, struct pnfs_layout_hdr,
+				plh_bulk_destroy);
+		dprintk("%s freeing layout for inode %lu\n", __func__,
+			lo->plh_inode->i_ino);
+		inode = lo->plh_inode;
+
+		pnfs_layoutcommit_inode(inode, false);
+
+		spin_lock(&inode->i_lock);
+		list_del_init(&lo->plh_bulk_destroy);
+		if (pnfs_mark_layout_stateid_invalid(lo, &lseg_list)) {
+			if (is_bulk_recall)
+				set_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags);
+			ret = -EAGAIN;
+		}
+		spin_unlock(&inode->i_lock);
+		pnfs_free_lseg_list(&lseg_list);
+		/* Free all lsegs that are attached to commit buckets */
+		nfs_commit_inode(inode, 0);
+		pnfs_put_layout_hdr(lo);
+		nfs_iput_and_deactive(inode);
+	}
+	return ret;
+}
+
+int
+pnfs_destroy_layouts_byfsid(struct nfs_client *clp,
+		struct nfs_fsid *fsid,
+		bool is_recall)
+{
+	struct nfs_server *server;
+	LIST_HEAD(layout_list);
+
+	spin_lock(&clp->cl_lock);
+	rcu_read_lock();
+restart:
+	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
+		if (memcmp(&server->fsid, fsid, sizeof(*fsid)) != 0)
+			continue;
+		if (pnfs_layout_bulk_destroy_byserver_locked(clp,
+				server,
+				&layout_list) != 0)
+			goto restart;
+	}
+	rcu_read_unlock();
+	spin_unlock(&clp->cl_lock);
+
+	if (list_empty(&layout_list))
+		return 0;
+	return pnfs_layout_free_bulk_destroy_list(&layout_list, is_recall);
+}
+
+int
+pnfs_destroy_layouts_byclid(struct nfs_client *clp,
+		bool is_recall)
+{
+	struct nfs_server *server;
+	LIST_HEAD(layout_list);
+
+	spin_lock(&clp->cl_lock);
+	rcu_read_lock();
+restart:
+	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
+		if (pnfs_layout_bulk_destroy_byserver_locked(clp,
+					server,
+					&layout_list) != 0)
+			goto restart;
+	}
+	rcu_read_unlock();
+	spin_unlock(&clp->cl_lock);
+
+	if (list_empty(&layout_list))
+		return 0;
+	return pnfs_layout_free_bulk_destroy_list(&layout_list, is_recall);
+}
+
+/*
+ * Called by the state manager to remove all layouts established under an
+ * expired lease.
+ */
+void
+pnfs_destroy_all_layouts(struct nfs_client *clp)
+{
+	nfs4_deviceid_mark_client_invalid(clp);
+	nfs4_deviceid_purge_client(clp);
+
+	pnfs_destroy_layouts_byclid(clp, false);
+}
+
+static void
+pnfs_set_layout_cred(struct pnfs_layout_hdr *lo, const struct cred *cred)
+{
+	const struct cred *old;
+
+	if (cred && cred_fscmp(lo->plh_lc_cred, cred) != 0) {
+		old = xchg(&lo->plh_lc_cred, get_cred(cred));
+		put_cred(old);
+	}
+}
+
+/* update lo->plh_stateid with new if is more recent */
+void
+pnfs_set_layout_stateid(struct pnfs_layout_hdr *lo, const nfs4_stateid *new,
+			const struct cred *cred, bool update_barrier)
+{
+	u32 oldseq = be32_to_cpu(lo->plh_stateid.seqid);
+	u32 newseq = be32_to_cpu(new->seqid);
+
+	if (!pnfs_layout_is_valid(lo)) {
+		pnfs_set_layout_cred(lo, cred);
+		nfs4_stateid_copy(&lo->plh_stateid, new);
+		lo->plh_barrier = newseq;
+		pnfs_clear_layoutreturn_info(lo);
+		clear_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags);
+		return;
+	}
+
+	if (pnfs_seqid_is_newer(newseq, oldseq))
+		nfs4_stateid_copy(&lo->plh_stateid, new);
+
+	if (update_barrier) {
+		pnfs_barrier_update(lo, newseq);
+		return;
+	}
+	/*
+	 * Because of wraparound, we want to keep the barrier
+	 * "close" to the current seqids. We really only want to
+	 * get here from a layoutget call.
+	 */
+	if (atomic_read(&lo->plh_outstanding) == 1)
+		 pnfs_barrier_update(lo, be32_to_cpu(lo->plh_stateid.seqid));
+}
+
+static bool
+pnfs_layout_stateid_blocked(const struct pnfs_layout_hdr *lo,
+		const nfs4_stateid *stateid)
+{
+	u32 seqid = be32_to_cpu(stateid->seqid);
+
+	return lo->plh_barrier && pnfs_seqid_is_newer(lo->plh_barrier, seqid);
+}
+
+/* lget is set to 1 if called from inside send_layoutget call chain */
+static bool
+pnfs_layoutgets_blocked(const struct pnfs_layout_hdr *lo)
+{
+	return lo->plh_block_lgets ||
+		test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags);
+}
+
+static struct nfs_server *
+pnfs_find_server(struct inode *inode, struct nfs_open_context *ctx)
+{
+	struct nfs_server *server;
+
+	if (inode) {
+		server = NFS_SERVER(inode);
+	} else {
+		struct dentry *parent_dir = dget_parent(ctx->dentry);
+		server = NFS_SERVER(parent_dir->d_inode);
+		dput(parent_dir);
+	}
+	return server;
+}
+
+static void nfs4_free_pages(struct page **pages, size_t size)
+{
+	int i;
+
+	if (!pages)
+		return;
+
+	for (i = 0; i < size; i++) {
+		if (!pages[i])
+			break;
+		__free_page(pages[i]);
+	}
+	kfree(pages);
+}
+
+static struct page **nfs4_alloc_pages(size_t size, gfp_t gfp_flags)
+{
+	struct page **pages;
+	int i;
+
+	pages = kmalloc_array(size, sizeof(struct page *), gfp_flags);
+	if (!pages) {
+		dprintk("%s: can't alloc array of %zu pages\n", __func__, size);
+		return NULL;
+	}
+
+	for (i = 0; i < size; i++) {
+		pages[i] = alloc_page(gfp_flags);
+		if (!pages[i]) {
+			dprintk("%s: failed to allocate page\n", __func__);
+			nfs4_free_pages(pages, i);
+			return NULL;
+		}
+	}
+
+	return pages;
+}
+
+static struct nfs4_layoutget *
+pnfs_alloc_init_layoutget_args(struct inode *ino,
+	   struct nfs_open_context *ctx,
+	   const nfs4_stateid *stateid,
+	   const struct pnfs_layout_range *range,
+	   gfp_t gfp_flags)
+{
+	struct nfs_server *server = pnfs_find_server(ino, ctx);
+	size_t max_reply_sz = server->pnfs_curr_ld->max_layoutget_response;
+	size_t max_pages = max_response_pages(server);
+	struct nfs4_layoutget *lgp;
+
+	dprintk("--> %s\n", __func__);
+
+	lgp = kzalloc(sizeof(*lgp), gfp_flags);
+	if (lgp == NULL)
+		return NULL;
+
+	if (max_reply_sz) {
+		size_t npages = (max_reply_sz + PAGE_SIZE - 1) >> PAGE_SHIFT;
+		if (npages < max_pages)
+			max_pages = npages;
+	}
+
+	lgp->args.layout.pages = nfs4_alloc_pages(max_pages, gfp_flags);
+	if (!lgp->args.layout.pages) {
+		kfree(lgp);
+		return NULL;
+	}
+	lgp->args.layout.pglen = max_pages * PAGE_SIZE;
+	lgp->res.layoutp = &lgp->args.layout;
+
+	/* Don't confuse uninitialised result and success */
+	lgp->res.status = -NFS4ERR_DELAY;
+
+	lgp->args.minlength = PAGE_SIZE;
+	if (lgp->args.minlength > range->length)
+		lgp->args.minlength = range->length;
+	if (ino) {
+		loff_t i_size = i_size_read(ino);
+
+		if (range->iomode == IOMODE_READ) {
+			if (range->offset >= i_size)
+				lgp->args.minlength = 0;
+			else if (i_size - range->offset < lgp->args.minlength)
+				lgp->args.minlength = i_size - range->offset;
+		}
+	}
+	lgp->args.maxcount = PNFS_LAYOUT_MAXSIZE;
+	pnfs_copy_range(&lgp->args.range, range);
+	lgp->args.type = server->pnfs_curr_ld->id;
+	lgp->args.inode = ino;
+	lgp->args.ctx = get_nfs_open_context(ctx);
+	nfs4_stateid_copy(&lgp->args.stateid, stateid);
+	lgp->gfp_flags = gfp_flags;
+	lgp->cred = ctx->cred;
+	return lgp;
+}
+
+void pnfs_layoutget_free(struct nfs4_layoutget *lgp)
+{
+	size_t max_pages = lgp->args.layout.pglen / PAGE_SIZE;
+
+	nfs4_free_pages(lgp->args.layout.pages, max_pages);
+	if (lgp->args.inode)
+		pnfs_put_layout_hdr(NFS_I(lgp->args.inode)->layout);
+	put_nfs_open_context(lgp->args.ctx);
+	kfree(lgp);
+}
+
+static void pnfs_clear_layoutcommit(struct inode *inode,
+		struct list_head *head)
+{
+	struct nfs_inode *nfsi = NFS_I(inode);
+	struct pnfs_layout_segment *lseg, *tmp;
+
+	if (!test_and_clear_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags))
+		return;
+	list_for_each_entry_safe(lseg, tmp, &nfsi->layout->plh_segs, pls_list) {
+		if (!test_and_clear_bit(NFS_LSEG_LAYOUTCOMMIT, &lseg->pls_flags))
+			continue;
+		pnfs_lseg_dec_and_remove_zero(lseg, head);
+	}
+}
+
+void pnfs_layoutreturn_free_lsegs(struct pnfs_layout_hdr *lo,
+		const nfs4_stateid *arg_stateid,
+		const struct pnfs_layout_range *range,
+		const nfs4_stateid *stateid)
+{
+	struct inode *inode = lo->plh_inode;
+	LIST_HEAD(freeme);
+
+	spin_lock(&inode->i_lock);
+	if (!pnfs_layout_is_valid(lo) || !arg_stateid ||
+	    !nfs4_stateid_match_other(&lo->plh_stateid, arg_stateid))
+		goto out_unlock;
+	if (stateid) {
+		u32 seq = be32_to_cpu(arg_stateid->seqid);
+
+		pnfs_mark_matching_lsegs_invalid(lo, &freeme, range, seq);
+		pnfs_free_returned_lsegs(lo, &freeme, range, seq);
+		pnfs_set_layout_stateid(lo, stateid, NULL, true);
+	} else
+		pnfs_mark_layout_stateid_invalid(lo, &freeme);
+out_unlock:
+	pnfs_clear_layoutreturn_waitbit(lo);
+	spin_unlock(&inode->i_lock);
+	pnfs_free_lseg_list(&freeme);
+
+}
+
+static bool
+pnfs_prepare_layoutreturn(struct pnfs_layout_hdr *lo,
+		nfs4_stateid *stateid,
+		const struct cred **cred,
+		enum pnfs_iomode *iomode)
+{
+	/* Serialise LAYOUTGET/LAYOUTRETURN */
+	if (atomic_read(&lo->plh_outstanding) != 0)
+		return false;
+	if (test_and_set_bit(NFS_LAYOUT_RETURN_LOCK, &lo->plh_flags))
+		return false;
+	set_bit(NFS_LAYOUT_RETURN, &lo->plh_flags);
+	pnfs_get_layout_hdr(lo);
+	nfs4_stateid_copy(stateid, &lo->plh_stateid);
+	*cred = get_cred(lo->plh_lc_cred);
+	if (test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags)) {
+		if (lo->plh_return_seq != 0)
+			stateid->seqid = cpu_to_be32(lo->plh_return_seq);
+		if (iomode != NULL)
+			*iomode = lo->plh_return_iomode;
+		pnfs_clear_layoutreturn_info(lo);
+	} else if (iomode != NULL)
+		*iomode = IOMODE_ANY;
+	pnfs_barrier_update(lo, be32_to_cpu(stateid->seqid));
+	return true;
+}
+
+static void
+pnfs_init_layoutreturn_args(struct nfs4_layoutreturn_args *args,
+		struct pnfs_layout_hdr *lo,
+		const nfs4_stateid *stateid,
+		enum pnfs_iomode iomode)
+{
+	struct inode *inode = lo->plh_inode;
+
+	args->layout_type = NFS_SERVER(inode)->pnfs_curr_ld->id;
+	args->inode = inode;
+	args->range.iomode = iomode;
+	args->range.offset = 0;
+	args->range.length = NFS4_MAX_UINT64;
+	args->layout = lo;
+	nfs4_stateid_copy(&args->stateid, stateid);
+}
+
+static int
+pnfs_send_layoutreturn(struct pnfs_layout_hdr *lo,
+		       const nfs4_stateid *stateid,
+		       const struct cred **pcred,
+		       enum pnfs_iomode iomode,
+		       bool sync)
+{
+	struct inode *ino = lo->plh_inode;
+	struct pnfs_layoutdriver_type *ld = NFS_SERVER(ino)->pnfs_curr_ld;
+	struct nfs4_layoutreturn *lrp;
+	const struct cred *cred = *pcred;
+	int status = 0;
+
+	*pcred = NULL;
+	lrp = kzalloc(sizeof(*lrp), GFP_NOFS);
+	if (unlikely(lrp == NULL)) {
+		status = -ENOMEM;
+		spin_lock(&ino->i_lock);
+		pnfs_clear_layoutreturn_waitbit(lo);
+		spin_unlock(&ino->i_lock);
+		put_cred(cred);
+		pnfs_put_layout_hdr(lo);
+		goto out;
+	}
+
+	pnfs_init_layoutreturn_args(&lrp->args, lo, stateid, iomode);
+	lrp->args.ld_private = &lrp->ld_private;
+	lrp->clp = NFS_SERVER(ino)->nfs_client;
+	lrp->cred = cred;
+	if (ld->prepare_layoutreturn)
+		ld->prepare_layoutreturn(&lrp->args);
+
+	status = nfs4_proc_layoutreturn(lrp, sync);
+out:
+	dprintk("<-- %s status: %d\n", __func__, status);
+	return status;
+}
+
+static bool
+pnfs_layout_segments_returnable(struct pnfs_layout_hdr *lo,
+				enum pnfs_iomode iomode,
+				u32 seq)
+{
+	struct pnfs_layout_range recall_range = {
+		.length = NFS4_MAX_UINT64,
+		.iomode = iomode,
+	};
+	return pnfs_mark_matching_lsegs_return(lo, &lo->plh_return_segs,
+					       &recall_range, seq) != -EBUSY;
+}
+
+/* Return true if layoutreturn is needed */
+static bool
+pnfs_layout_need_return(struct pnfs_layout_hdr *lo)
+{
+	if (!test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags))
+		return false;
+	return pnfs_layout_segments_returnable(lo, lo->plh_return_iomode,
+					       lo->plh_return_seq);
+}
+
+static void pnfs_layoutreturn_before_put_layout_hdr(struct pnfs_layout_hdr *lo)
+{
+	struct inode *inode= lo->plh_inode;
+
+	if (!test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags))
+		return;
+	spin_lock(&inode->i_lock);
+	if (pnfs_layout_need_return(lo)) {
+		const struct cred *cred;
+		nfs4_stateid stateid;
+		enum pnfs_iomode iomode;
+		bool send;
+
+		send = pnfs_prepare_layoutreturn(lo, &stateid, &cred, &iomode);
+		spin_unlock(&inode->i_lock);
+		if (send) {
+			/* Send an async layoutreturn so we dont deadlock */
+			pnfs_send_layoutreturn(lo, &stateid, &cred, iomode, false);
+		}
+	} else
+		spin_unlock(&inode->i_lock);
+}
+
+/*
+ * Initiates a LAYOUTRETURN(FILE), and removes the pnfs_layout_hdr
+ * when the layout segment list is empty.
+ *
+ * Note that a pnfs_layout_hdr can exist with an empty layout segment
+ * list when LAYOUTGET has failed, or when LAYOUTGET succeeded, but the
+ * deviceid is marked invalid.
+ */
+int
+_pnfs_return_layout(struct inode *ino)
+{
+	struct pnfs_layout_hdr *lo = NULL;
+	struct nfs_inode *nfsi = NFS_I(ino);
+	struct pnfs_layout_range range = {
+		.iomode		= IOMODE_ANY,
+		.offset		= 0,
+		.length		= NFS4_MAX_UINT64,
+	};
+	LIST_HEAD(tmp_list);
+	const struct cred *cred;
+	nfs4_stateid stateid;
+	int status = 0;
+	bool send, valid_layout;
+
+	dprintk("NFS: %s for inode %lu\n", __func__, ino->i_ino);
+
+	spin_lock(&ino->i_lock);
+	lo = nfsi->layout;
+	if (!lo) {
+		spin_unlock(&ino->i_lock);
+		dprintk("NFS: %s no layout to return\n", __func__);
+		goto out;
+	}
+	/* Reference matched in nfs4_layoutreturn_release */
+	pnfs_get_layout_hdr(lo);
+	/* Is there an outstanding layoutreturn ? */
+	if (test_bit(NFS_LAYOUT_RETURN_LOCK, &lo->plh_flags)) {
+		spin_unlock(&ino->i_lock);
+		if (wait_on_bit(&lo->plh_flags, NFS_LAYOUT_RETURN,
+					TASK_UNINTERRUPTIBLE))
+			goto out_put_layout_hdr;
+		spin_lock(&ino->i_lock);
+	}
+	valid_layout = pnfs_layout_is_valid(lo);
+	pnfs_clear_layoutcommit(ino, &tmp_list);
+	pnfs_mark_matching_lsegs_return(lo, &tmp_list, &range, 0);
+
+	if (NFS_SERVER(ino)->pnfs_curr_ld->return_range)
+		NFS_SERVER(ino)->pnfs_curr_ld->return_range(lo, &range);
+
+	/* Don't send a LAYOUTRETURN if list was initially empty */
+	if (!test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags) ||
+			!valid_layout) {
+		spin_unlock(&ino->i_lock);
+		dprintk("NFS: %s no layout segments to return\n", __func__);
+		goto out_wait_layoutreturn;
+	}
+
+	send = pnfs_prepare_layoutreturn(lo, &stateid, &cred, NULL);
+	spin_unlock(&ino->i_lock);
+	if (send)
+		status = pnfs_send_layoutreturn(lo, &stateid, &cred, IOMODE_ANY, true);
+out_wait_layoutreturn:
+	wait_on_bit(&lo->plh_flags, NFS_LAYOUT_RETURN, TASK_UNINTERRUPTIBLE);
+out_put_layout_hdr:
+	pnfs_free_lseg_list(&tmp_list);
+	pnfs_put_layout_hdr(lo);
+out:
+	dprintk("<-- %s status: %d\n", __func__, status);
+	return status;
+}
+
+int
+pnfs_commit_and_return_layout(struct inode *inode)
+{
+	struct pnfs_layout_hdr *lo;
+	int ret;
+
+	spin_lock(&inode->i_lock);
+	lo = NFS_I(inode)->layout;
+	if (lo == NULL) {
+		spin_unlock(&inode->i_lock);
+		return 0;
+	}
+	pnfs_get_layout_hdr(lo);
+	/* Block new layoutgets and read/write to ds */
+	lo->plh_block_lgets++;
+	spin_unlock(&inode->i_lock);
+	filemap_fdatawait(inode->i_mapping);
+	ret = pnfs_layoutcommit_inode(inode, true);
+	if (ret == 0)
+		ret = _pnfs_return_layout(inode);
+	spin_lock(&inode->i_lock);
+	lo->plh_block_lgets--;
+	spin_unlock(&inode->i_lock);
+	pnfs_put_layout_hdr(lo);
+	return ret;
+}
+
+bool pnfs_roc(struct inode *ino,
+		struct nfs4_layoutreturn_args *args,
+		struct nfs4_layoutreturn_res *res,
+		const struct cred *cred)
+{
+	struct nfs_inode *nfsi = NFS_I(ino);
+	struct nfs_open_context *ctx;
+	struct nfs4_state *state;
+	struct pnfs_layout_hdr *lo;
+	struct pnfs_layout_segment *lseg, *next;
+	const struct cred *lc_cred;
+	nfs4_stateid stateid;
+	enum pnfs_iomode iomode = 0;
+	bool layoutreturn = false, roc = false;
+	bool skip_read = false;
+
+	if (!nfs_have_layout(ino))
+		return false;
+retry:
+	rcu_read_lock();
+	spin_lock(&ino->i_lock);
+	lo = nfsi->layout;
+	if (!lo || !pnfs_layout_is_valid(lo) ||
+	    test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags)) {
+		lo = NULL;
+		goto out_noroc;
+	}
+	pnfs_get_layout_hdr(lo);
+	if (test_bit(NFS_LAYOUT_RETURN_LOCK, &lo->plh_flags)) {
+		spin_unlock(&ino->i_lock);
+		rcu_read_unlock();
+		wait_on_bit(&lo->plh_flags, NFS_LAYOUT_RETURN,
+				TASK_UNINTERRUPTIBLE);
+		pnfs_put_layout_hdr(lo);
+		goto retry;
+	}
+
+	/* no roc if we hold a delegation */
+	if (nfs4_check_delegation(ino, FMODE_READ)) {
+		if (nfs4_check_delegation(ino, FMODE_WRITE))
+			goto out_noroc;
+		skip_read = true;
+	}
+
+	list_for_each_entry_rcu(ctx, &nfsi->open_files, list) {
+		state = ctx->state;
+		if (state == NULL)
+			continue;
+		/* Don't return layout if there is open file state */
+		if (state->state & FMODE_WRITE)
+			goto out_noroc;
+		if (state->state & FMODE_READ)
+			skip_read = true;
+	}
+
+
+	list_for_each_entry_safe(lseg, next, &lo->plh_segs, pls_list) {
+		if (skip_read && lseg->pls_range.iomode == IOMODE_READ)
+			continue;
+		/* If we are sending layoutreturn, invalidate all valid lsegs */
+		if (!test_and_clear_bit(NFS_LSEG_ROC, &lseg->pls_flags))
+			continue;
+		/*
+		 * Note: mark lseg for return so pnfs_layout_remove_lseg
+		 * doesn't invalidate the layout for us.
+		 */
+		set_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags);
+		if (!mark_lseg_invalid(lseg, &lo->plh_return_segs))
+			continue;
+		pnfs_set_plh_return_info(lo, lseg->pls_range.iomode, 0);
+	}
+
+	if (!test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags))
+		goto out_noroc;
+
+	/* ROC in two conditions:
+	 * 1. there are ROC lsegs
+	 * 2. we don't send layoutreturn
+	 */
+	/* lo ref dropped in pnfs_roc_release() */
+	layoutreturn = pnfs_prepare_layoutreturn(lo, &stateid, &lc_cred, &iomode);
+	/* If the creds don't match, we can't compound the layoutreturn */
+	if (!layoutreturn || cred_fscmp(cred, lc_cred) != 0)
+		goto out_noroc;
+
+	roc = layoutreturn;
+	pnfs_init_layoutreturn_args(args, lo, &stateid, iomode);
+	res->lrs_present = 0;
+	layoutreturn = false;
+	put_cred(lc_cred);
+
+out_noroc:
+	spin_unlock(&ino->i_lock);
+	rcu_read_unlock();
+	pnfs_layoutcommit_inode(ino, true);
+	if (roc) {
+		struct pnfs_layoutdriver_type *ld = NFS_SERVER(ino)->pnfs_curr_ld;
+		if (ld->prepare_layoutreturn)
+			ld->prepare_layoutreturn(args);
+		pnfs_put_layout_hdr(lo);
+		return true;
+	}
+	if (layoutreturn)
+		pnfs_send_layoutreturn(lo, &stateid, &lc_cred, iomode, true);
+	pnfs_put_layout_hdr(lo);
+	return false;
+}
+
+int pnfs_roc_done(struct rpc_task *task, struct nfs4_layoutreturn_args **argpp,
+		  struct nfs4_layoutreturn_res **respp, int *ret)
+{
+	struct nfs4_layoutreturn_args *arg = *argpp;
+	int retval = -EAGAIN;
+
+	if (!arg)
+		return 0;
+	/* Handle Layoutreturn errors */
+	switch (*ret) {
+	case 0:
+		retval = 0;
+		break;
+	case -NFS4ERR_NOMATCHING_LAYOUT:
+		/* Was there an RPC level error? If not, retry */
+		if (task->tk_rpc_status == 0)
+			break;
+		/* If the call was not sent, let caller handle it */
+		if (!RPC_WAS_SENT(task))
+			return 0;
+		/*
+		 * Otherwise, assume the call succeeded and
+		 * that we need to release the layout
+		 */
+		*ret = 0;
+		(*respp)->lrs_present = 0;
+		retval = 0;
+		break;
+	case -NFS4ERR_DELAY:
+		/* Let the caller handle the retry */
+		*ret = -NFS4ERR_NOMATCHING_LAYOUT;
+		return 0;
+	case -NFS4ERR_OLD_STATEID:
+		if (!nfs4_layout_refresh_old_stateid(&arg->stateid,
+						     &arg->range, arg->inode))
+			break;
+		*ret = -NFS4ERR_NOMATCHING_LAYOUT;
+		return -EAGAIN;
+	}
+	*argpp = NULL;
+	*respp = NULL;
+	return retval;
+}
+
+void pnfs_roc_release(struct nfs4_layoutreturn_args *args,
+		struct nfs4_layoutreturn_res *res,
+		int ret)
+{
+	struct pnfs_layout_hdr *lo = args->layout;
+	struct inode *inode = args->inode;
+	const nfs4_stateid *arg_stateid = NULL;
+	const nfs4_stateid *res_stateid = NULL;
+	struct nfs4_xdr_opaque_data *ld_private = args->ld_private;
+
+	switch (ret) {
+	case -NFS4ERR_NOMATCHING_LAYOUT:
+		spin_lock(&inode->i_lock);
+		if (pnfs_layout_is_valid(lo) &&
+		    nfs4_stateid_match_other(&args->stateid, &lo->plh_stateid))
+			pnfs_set_plh_return_info(lo, args->range.iomode, 0);
+		spin_unlock(&inode->i_lock);
+		break;
+	case 0:
+		if (res->lrs_present)
+			res_stateid = &res->stateid;
+		fallthrough;
+	default:
+		arg_stateid = &args->stateid;
+	}
+	trace_nfs4_layoutreturn_on_close(args->inode, &args->stateid, ret);
+	pnfs_layoutreturn_free_lsegs(lo, arg_stateid, &args->range,
+			res_stateid);
+	if (ld_private && ld_private->ops && ld_private->ops->free)
+		ld_private->ops->free(ld_private);
+	pnfs_put_layout_hdr(lo);
+}
+
+bool pnfs_wait_on_layoutreturn(struct inode *ino, struct rpc_task *task)
+{
+	struct nfs_inode *nfsi = NFS_I(ino);
+        struct pnfs_layout_hdr *lo;
+        bool sleep = false;
+
+	/* we might not have grabbed lo reference. so need to check under
+	 * i_lock */
+        spin_lock(&ino->i_lock);
+        lo = nfsi->layout;
+        if (lo && test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags)) {
+                rpc_sleep_on(&NFS_SERVER(ino)->roc_rpcwaitq, task, NULL);
+                sleep = true;
+	}
+        spin_unlock(&ino->i_lock);
+        return sleep;
+}
+
+/*
+ * Compare two layout segments for sorting into layout cache.
+ * We want to preferentially return RW over RO layouts, so ensure those
+ * are seen first.
+ */
+static s64
+pnfs_lseg_range_cmp(const struct pnfs_layout_range *l1,
+	   const struct pnfs_layout_range *l2)
+{
+	s64 d;
+
+	/* high offset > low offset */
+	d = l1->offset - l2->offset;
+	if (d)
+		return d;
+
+	/* short length > long length */
+	d = l2->length - l1->length;
+	if (d)
+		return d;
+
+	/* read > read/write */
+	return (int)(l1->iomode == IOMODE_READ) - (int)(l2->iomode == IOMODE_READ);
+}
+
+static bool
+pnfs_lseg_range_is_after(const struct pnfs_layout_range *l1,
+		const struct pnfs_layout_range *l2)
+{
+	return pnfs_lseg_range_cmp(l1, l2) > 0;
+}
+
+static bool
+pnfs_lseg_no_merge(struct pnfs_layout_segment *lseg,
+		struct pnfs_layout_segment *old)
+{
+	return false;
+}
+
+void
+pnfs_generic_layout_insert_lseg(struct pnfs_layout_hdr *lo,
+		   struct pnfs_layout_segment *lseg,
+		   bool (*is_after)(const struct pnfs_layout_range *,
+			   const struct pnfs_layout_range *),
+		   bool (*do_merge)(struct pnfs_layout_segment *,
+			   struct pnfs_layout_segment *),
+		   struct list_head *free_me)
+{
+	struct pnfs_layout_segment *lp, *tmp;
+
+	dprintk("%s:Begin\n", __func__);
+
+	list_for_each_entry_safe(lp, tmp, &lo->plh_segs, pls_list) {
+		if (test_bit(NFS_LSEG_VALID, &lp->pls_flags) == 0)
+			continue;
+		if (do_merge(lseg, lp)) {
+			mark_lseg_invalid(lp, free_me);
+			continue;
+		}
+		if (is_after(&lseg->pls_range, &lp->pls_range))
+			continue;
+		list_add_tail(&lseg->pls_list, &lp->pls_list);
+		dprintk("%s: inserted lseg %p "
+			"iomode %d offset %llu length %llu before "
+			"lp %p iomode %d offset %llu length %llu\n",
+			__func__, lseg, lseg->pls_range.iomode,
+			lseg->pls_range.offset, lseg->pls_range.length,
+			lp, lp->pls_range.iomode, lp->pls_range.offset,
+			lp->pls_range.length);
+		goto out;
+	}
+	list_add_tail(&lseg->pls_list, &lo->plh_segs);
+	dprintk("%s: inserted lseg %p "
+		"iomode %d offset %llu length %llu at tail\n",
+		__func__, lseg, lseg->pls_range.iomode,
+		lseg->pls_range.offset, lseg->pls_range.length);
+out:
+	pnfs_get_layout_hdr(lo);
+
+	dprintk("%s:Return\n", __func__);
+}
+EXPORT_SYMBOL_GPL(pnfs_generic_layout_insert_lseg);
+
+static void
+pnfs_layout_insert_lseg(struct pnfs_layout_hdr *lo,
+		   struct pnfs_layout_segment *lseg,
+		   struct list_head *free_me)
+{
+	struct inode *inode = lo->plh_inode;
+	struct pnfs_layoutdriver_type *ld = NFS_SERVER(inode)->pnfs_curr_ld;
+
+	if (ld->add_lseg != NULL)
+		ld->add_lseg(lo, lseg, free_me);
+	else
+		pnfs_generic_layout_insert_lseg(lo, lseg,
+				pnfs_lseg_range_is_after,
+				pnfs_lseg_no_merge,
+				free_me);
+}
+
+static struct pnfs_layout_hdr *
+alloc_init_layout_hdr(struct inode *ino,
+		      struct nfs_open_context *ctx,
+		      gfp_t gfp_flags)
+{
+	struct pnfs_layout_hdr *lo;
+
+	lo = pnfs_alloc_layout_hdr(ino, gfp_flags);
+	if (!lo)
+		return NULL;
+	refcount_set(&lo->plh_refcount, 1);
+	INIT_LIST_HEAD(&lo->plh_layouts);
+	INIT_LIST_HEAD(&lo->plh_segs);
+	INIT_LIST_HEAD(&lo->plh_return_segs);
+	INIT_LIST_HEAD(&lo->plh_bulk_destroy);
+	lo->plh_inode = ino;
+	lo->plh_lc_cred = get_cred(ctx->cred);
+	lo->plh_flags |= 1 << NFS_LAYOUT_INVALID_STID;
+	return lo;
+}
+
+static struct pnfs_layout_hdr *
+pnfs_find_alloc_layout(struct inode *ino,
+		       struct nfs_open_context *ctx,
+		       gfp_t gfp_flags)
+	__releases(&ino->i_lock)
+	__acquires(&ino->i_lock)
+{
+	struct nfs_inode *nfsi = NFS_I(ino);
+	struct pnfs_layout_hdr *new = NULL;
+
+	dprintk("%s Begin ino=%p layout=%p\n", __func__, ino, nfsi->layout);
+
+	if (nfsi->layout != NULL)
+		goto out_existing;
+	spin_unlock(&ino->i_lock);
+	new = alloc_init_layout_hdr(ino, ctx, gfp_flags);
+	spin_lock(&ino->i_lock);
+
+	if (likely(nfsi->layout == NULL)) {	/* Won the race? */
+		nfsi->layout = new;
+		return new;
+	} else if (new != NULL)
+		pnfs_free_layout_hdr(new);
+out_existing:
+	pnfs_get_layout_hdr(nfsi->layout);
+	return nfsi->layout;
+}
+
+/*
+ * iomode matching rules:
+ * iomode	lseg	strict match
+ *                      iomode
+ * -----	-----	------ -----
+ * ANY		READ	N/A    true
+ * ANY		RW	N/A    true
+ * RW		READ	N/A    false
+ * RW		RW	N/A    true
+ * READ		READ	N/A    true
+ * READ		RW	true   false
+ * READ		RW	false  true
+ */
+static bool
+pnfs_lseg_range_match(const struct pnfs_layout_range *ls_range,
+		 const struct pnfs_layout_range *range,
+		 bool strict_iomode)
+{
+	struct pnfs_layout_range range1;
+
+	if ((range->iomode == IOMODE_RW &&
+	     ls_range->iomode != IOMODE_RW) ||
+	    (range->iomode != ls_range->iomode &&
+	     strict_iomode) ||
+	    !pnfs_lseg_range_intersecting(ls_range, range))
+		return false;
+
+	/* range1 covers only the first byte in the range */
+	range1 = *range;
+	range1.length = 1;
+	return pnfs_lseg_range_contained(ls_range, &range1);
+}
+
+/*
+ * lookup range in layout
+ */
+static struct pnfs_layout_segment *
+pnfs_find_lseg(struct pnfs_layout_hdr *lo,
+		struct pnfs_layout_range *range,
+		bool strict_iomode)
+{
+	struct pnfs_layout_segment *lseg, *ret = NULL;
+
+	dprintk("%s:Begin\n", __func__);
+
+	list_for_each_entry(lseg, &lo->plh_segs, pls_list) {
+		if (test_bit(NFS_LSEG_VALID, &lseg->pls_flags) &&
+		    pnfs_lseg_range_match(&lseg->pls_range, range,
+					  strict_iomode)) {
+			ret = pnfs_get_lseg(lseg);
+			break;
+		}
+	}
+
+	dprintk("%s:Return lseg %p ref %d\n",
+		__func__, ret, ret ? refcount_read(&ret->pls_refcount) : 0);
+	return ret;
+}
+
+/*
+ * Use mdsthreshold hints set at each OPEN to determine if I/O should go
+ * to the MDS or over pNFS
+ *
+ * The nfs_inode read_io and write_io fields are cumulative counters reset
+ * when there are no layout segments. Note that in pnfs_update_layout iomode
+ * is set to IOMODE_READ for a READ request, and set to IOMODE_RW for a
+ * WRITE request.
+ *
+ * A return of true means use MDS I/O.
+ *
+ * From rfc 5661:
+ * If a file's size is smaller than the file size threshold, data accesses
+ * SHOULD be sent to the metadata server.  If an I/O request has a length that
+ * is below the I/O size threshold, the I/O SHOULD be sent to the metadata
+ * server.  If both file size and I/O size are provided, the client SHOULD
+ * reach or exceed  both thresholds before sending its read or write
+ * requests to the data server.
+ */
+static bool pnfs_within_mdsthreshold(struct nfs_open_context *ctx,
+				     struct inode *ino, int iomode)
+{
+	struct nfs4_threshold *t = ctx->mdsthreshold;
+	struct nfs_inode *nfsi = NFS_I(ino);
+	loff_t fsize = i_size_read(ino);
+	bool size = false, size_set = false, io = false, io_set = false, ret = false;
+
+	if (t == NULL)
+		return ret;
+
+	dprintk("%s bm=0x%x rd_sz=%llu wr_sz=%llu rd_io=%llu wr_io=%llu\n",
+		__func__, t->bm, t->rd_sz, t->wr_sz, t->rd_io_sz, t->wr_io_sz);
+
+	switch (iomode) {
+	case IOMODE_READ:
+		if (t->bm & THRESHOLD_RD) {
+			dprintk("%s fsize %llu\n", __func__, fsize);
+			size_set = true;
+			if (fsize < t->rd_sz)
+				size = true;
+		}
+		if (t->bm & THRESHOLD_RD_IO) {
+			dprintk("%s nfsi->read_io %llu\n", __func__,
+				nfsi->read_io);
+			io_set = true;
+			if (nfsi->read_io < t->rd_io_sz)
+				io = true;
+		}
+		break;
+	case IOMODE_RW:
+		if (t->bm & THRESHOLD_WR) {
+			dprintk("%s fsize %llu\n", __func__, fsize);
+			size_set = true;
+			if (fsize < t->wr_sz)
+				size = true;
+		}
+		if (t->bm & THRESHOLD_WR_IO) {
+			dprintk("%s nfsi->write_io %llu\n", __func__,
+				nfsi->write_io);
+			io_set = true;
+			if (nfsi->write_io < t->wr_io_sz)
+				io = true;
+		}
+		break;
+	}
+	if (size_set && io_set) {
+		if (size && io)
+			ret = true;
+	} else if (size || io)
+		ret = true;
+
+	dprintk("<-- %s size %d io %d ret %d\n", __func__, size, io, ret);
+	return ret;
+}
+
+static int pnfs_prepare_to_retry_layoutget(struct pnfs_layout_hdr *lo)
+{
+	/*
+	 * send layoutcommit as it can hold up layoutreturn due to lseg
+	 * reference
+	 */
+	pnfs_layoutcommit_inode(lo->plh_inode, false);
+	return wait_on_bit_action(&lo->plh_flags, NFS_LAYOUT_RETURN,
+				   nfs_wait_bit_killable,
+				   TASK_KILLABLE);
+}
+
+static void nfs_layoutget_begin(struct pnfs_layout_hdr *lo)
+{
+	atomic_inc(&lo->plh_outstanding);
+}
+
+static void nfs_layoutget_end(struct pnfs_layout_hdr *lo)
+{
+	if (atomic_dec_and_test(&lo->plh_outstanding) &&
+	    test_and_clear_bit(NFS_LAYOUT_DRAIN, &lo->plh_flags))
+		wake_up_bit(&lo->plh_flags, NFS_LAYOUT_DRAIN);
+}
+
+static bool pnfs_is_first_layoutget(struct pnfs_layout_hdr *lo)
+{
+	return test_bit(NFS_LAYOUT_FIRST_LAYOUTGET, &lo->plh_flags);
+}
+
+static void pnfs_clear_first_layoutget(struct pnfs_layout_hdr *lo)
+{
+	unsigned long *bitlock = &lo->plh_flags;
+
+	clear_bit_unlock(NFS_LAYOUT_FIRST_LAYOUTGET, bitlock);
+	smp_mb__after_atomic();
+	wake_up_bit(bitlock, NFS_LAYOUT_FIRST_LAYOUTGET);
+}
+
+static void _add_to_server_list(struct pnfs_layout_hdr *lo,
+				struct nfs_server *server)
+{
+	if (!test_and_set_bit(NFS_LAYOUT_HASHED, &lo->plh_flags)) {
+		struct nfs_client *clp = server->nfs_client;
+
+		/* The lo must be on the clp list if there is any
+		 * chance of a CB_LAYOUTRECALL(FILE) coming in.
+		 */
+		spin_lock(&clp->cl_lock);
+		list_add_tail_rcu(&lo->plh_layouts, &server->layouts);
+		spin_unlock(&clp->cl_lock);
+	}
+}
+
+/*
+ * Layout segment is retreived from the server if not cached.
+ * The appropriate layout segment is referenced and returned to the caller.
+ */
+struct pnfs_layout_segment *
+pnfs_update_layout(struct inode *ino,
+		   struct nfs_open_context *ctx,
+		   loff_t pos,
+		   u64 count,
+		   enum pnfs_iomode iomode,
+		   bool strict_iomode,
+		   gfp_t gfp_flags)
+{
+	struct pnfs_layout_range arg = {
+		.iomode = iomode,
+		.offset = pos,
+		.length = count,
+	};
+	unsigned pg_offset;
+	struct nfs_server *server = NFS_SERVER(ino);
+	struct nfs_client *clp = server->nfs_client;
+	struct pnfs_layout_hdr *lo = NULL;
+	struct pnfs_layout_segment *lseg = NULL;
+	struct nfs4_layoutget *lgp;
+	nfs4_stateid stateid;
+	long timeout = 0;
+	unsigned long giveup = jiffies + (clp->cl_lease_time << 1);
+	bool first;
+
+	if (!pnfs_enabled_sb(NFS_SERVER(ino))) {
+		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
+				 PNFS_UPDATE_LAYOUT_NO_PNFS);
+		goto out;
+	}
+
+	if (pnfs_within_mdsthreshold(ctx, ino, iomode)) {
+		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
+				 PNFS_UPDATE_LAYOUT_MDSTHRESH);
+		goto out;
+	}
+
+lookup_again:
+	lseg = ERR_PTR(nfs4_client_recover_expired_lease(clp));
+	if (IS_ERR(lseg))
+		goto out;
+	first = false;
+	spin_lock(&ino->i_lock);
+	lo = pnfs_find_alloc_layout(ino, ctx, gfp_flags);
+	if (lo == NULL) {
+		spin_unlock(&ino->i_lock);
+		lseg = ERR_PTR(-ENOMEM);
+		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
+				 PNFS_UPDATE_LAYOUT_NOMEM);
+		goto out;
+	}
+
+	/* Do we even need to bother with this? */
+	if (test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags)) {
+		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
+				 PNFS_UPDATE_LAYOUT_BULK_RECALL);
+		dprintk("%s matches recall, use MDS\n", __func__);
+		goto out_unlock;
+	}
+
+	/* if LAYOUTGET already failed once we don't try again */
+	if (pnfs_layout_io_test_failed(lo, iomode)) {
+		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
+				 PNFS_UPDATE_LAYOUT_IO_TEST_FAIL);
+		goto out_unlock;
+	}
+
+	/*
+	 * If the layout segment list is empty, but there are outstanding
+	 * layoutget calls, then they might be subject to a layoutrecall.
+	 */
+	if (test_bit(NFS_LAYOUT_DRAIN, &lo->plh_flags) &&
+	    atomic_read(&lo->plh_outstanding) != 0) {
+		spin_unlock(&ino->i_lock);
+		lseg = ERR_PTR(wait_on_bit(&lo->plh_flags, NFS_LAYOUT_DRAIN,
+					   TASK_KILLABLE));
+		if (IS_ERR(lseg))
+			goto out_put_layout_hdr;
+		pnfs_put_layout_hdr(lo);
+		goto lookup_again;
+	}
+
+	/*
+	 * Because we free lsegs when sending LAYOUTRETURN, we need to wait
+	 * for LAYOUTRETURN.
+	 */
+	if (test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags)) {
+		spin_unlock(&ino->i_lock);
+		dprintk("%s wait for layoutreturn\n", __func__);
+		lseg = ERR_PTR(pnfs_prepare_to_retry_layoutget(lo));
+		if (!IS_ERR(lseg)) {
+			pnfs_put_layout_hdr(lo);
+			dprintk("%s retrying\n", __func__);
+			trace_pnfs_update_layout(ino, pos, count, iomode, lo,
+						 lseg,
+						 PNFS_UPDATE_LAYOUT_RETRY);
+			goto lookup_again;
+		}
+		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
+					 PNFS_UPDATE_LAYOUT_RETURN);
+		goto out_put_layout_hdr;
+	}
+
+	lseg = pnfs_find_lseg(lo, &arg, strict_iomode);
+	if (lseg) {
+		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
+				PNFS_UPDATE_LAYOUT_FOUND_CACHED);
+		goto out_unlock;
+	}
+
+	/*
+	 * Choose a stateid for the LAYOUTGET. If we don't have a layout
+	 * stateid, or it has been invalidated, then we must use the open
+	 * stateid.
+	 */
+	if (test_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags)) {
+		int status;
+
+		/*
+		 * The first layoutget for the file. Need to serialize per
+		 * RFC 5661 Errata 3208.
+		 */
+		if (test_and_set_bit(NFS_LAYOUT_FIRST_LAYOUTGET,
+				     &lo->plh_flags)) {
+			spin_unlock(&ino->i_lock);
+			lseg = ERR_PTR(wait_on_bit(&lo->plh_flags,
+						NFS_LAYOUT_FIRST_LAYOUTGET,
+						TASK_KILLABLE));
+			if (IS_ERR(lseg))
+				goto out_put_layout_hdr;
+			pnfs_put_layout_hdr(lo);
+			dprintk("%s retrying\n", __func__);
+			goto lookup_again;
+		}
+
+		spin_unlock(&ino->i_lock);
+		first = true;
+		status = nfs4_select_rw_stateid(ctx->state,
+					iomode == IOMODE_RW ? FMODE_WRITE : FMODE_READ,
+					NULL, &stateid, NULL);
+		if (status != 0) {
+			lseg = ERR_PTR(status);
+			trace_pnfs_update_layout(ino, pos, count,
+					iomode, lo, lseg,
+					PNFS_UPDATE_LAYOUT_INVALID_OPEN);
+			nfs4_schedule_stateid_recovery(server, ctx->state);
+			pnfs_clear_first_layoutget(lo);
+			pnfs_put_layout_hdr(lo);
+			goto lookup_again;
+		}
+		spin_lock(&ino->i_lock);
+	} else {
+		nfs4_stateid_copy(&stateid, &lo->plh_stateid);
+	}
+
+	if (pnfs_layoutgets_blocked(lo)) {
+		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
+				PNFS_UPDATE_LAYOUT_BLOCKED);
+		goto out_unlock;
+	}
+	nfs_layoutget_begin(lo);
+	spin_unlock(&ino->i_lock);
+
+	_add_to_server_list(lo, server);
+
+	pg_offset = arg.offset & ~PAGE_MASK;
+	if (pg_offset) {
+		arg.offset -= pg_offset;
+		arg.length += pg_offset;
+	}
+	if (arg.length != NFS4_MAX_UINT64)
+		arg.length = PAGE_ALIGN(arg.length);
+
+	lgp = pnfs_alloc_init_layoutget_args(ino, ctx, &stateid, &arg, gfp_flags);
+	if (!lgp) {
+		lseg = ERR_PTR(-ENOMEM);
+		trace_pnfs_update_layout(ino, pos, count, iomode, lo, NULL,
+					 PNFS_UPDATE_LAYOUT_NOMEM);
+		nfs_layoutget_end(lo);
+		goto out_put_layout_hdr;
+	}
+
+	lseg = nfs4_proc_layoutget(lgp, &timeout);
+	trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
+				 PNFS_UPDATE_LAYOUT_SEND_LAYOUTGET);
+	nfs_layoutget_end(lo);
+	if (IS_ERR(lseg)) {
+		switch(PTR_ERR(lseg)) {
+		case -EBUSY:
+			if (time_after(jiffies, giveup))
+				lseg = NULL;
+			break;
+		case -ERECALLCONFLICT:
+		case -EAGAIN:
+			break;
+		case -ENODATA:
+			/* The server returned NFS4ERR_LAYOUTUNAVAILABLE */
+			pnfs_layout_set_fail_bit(
+				lo, pnfs_iomode_to_fail_bit(iomode));
+			lseg = NULL;
+			goto out_put_layout_hdr;
+		default:
+			if (!nfs_error_is_fatal(PTR_ERR(lseg))) {
+				pnfs_layout_clear_fail_bit(lo, pnfs_iomode_to_fail_bit(iomode));
+				lseg = NULL;
+			}
+			goto out_put_layout_hdr;
+		}
+		if (lseg) {
+			if (first)
+				pnfs_clear_first_layoutget(lo);
+			trace_pnfs_update_layout(ino, pos, count,
+				iomode, lo, lseg, PNFS_UPDATE_LAYOUT_RETRY);
+			pnfs_put_layout_hdr(lo);
+			goto lookup_again;
+		}
+	} else {
+		pnfs_layout_clear_fail_bit(lo, pnfs_iomode_to_fail_bit(iomode));
+	}
+
+out_put_layout_hdr:
+	if (first)
+		pnfs_clear_first_layoutget(lo);
+	trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
+				 PNFS_UPDATE_LAYOUT_EXIT);
+	pnfs_put_layout_hdr(lo);
+out:
+	dprintk("%s: inode %s/%llu pNFS layout segment %s for "
+			"(%s, offset: %llu, length: %llu)\n",
+			__func__, ino->i_sb->s_id,
+			(unsigned long long)NFS_FILEID(ino),
+			IS_ERR_OR_NULL(lseg) ? "not found" : "found",
+			iomode==IOMODE_RW ?  "read/write" : "read-only",
+			(unsigned long long)pos,
+			(unsigned long long)count);
+	return lseg;
+out_unlock:
+	spin_unlock(&ino->i_lock);
+	goto out_put_layout_hdr;
+}
+EXPORT_SYMBOL_GPL(pnfs_update_layout);
+
+static bool
+pnfs_sanity_check_layout_range(struct pnfs_layout_range *range)
+{
+	switch (range->iomode) {
+	case IOMODE_READ:
+	case IOMODE_RW:
+		break;
+	default:
+		return false;
+	}
+	if (range->offset == NFS4_MAX_UINT64)
+		return false;
+	if (range->length == 0)
+		return false;
+	if (range->length != NFS4_MAX_UINT64 &&
+	    range->length > NFS4_MAX_UINT64 - range->offset)
+		return false;
+	return true;
+}
+
+static struct pnfs_layout_hdr *
+_pnfs_grab_empty_layout(struct inode *ino, struct nfs_open_context *ctx)
+{
+	struct pnfs_layout_hdr *lo;
+
+	spin_lock(&ino->i_lock);
+	lo = pnfs_find_alloc_layout(ino, ctx, GFP_KERNEL);
+	if (!lo)
+		goto out_unlock;
+	if (!test_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags))
+		goto out_unlock;
+	if (test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags))
+		goto out_unlock;
+	if (pnfs_layoutgets_blocked(lo))
+		goto out_unlock;
+	if (test_and_set_bit(NFS_LAYOUT_FIRST_LAYOUTGET, &lo->plh_flags))
+		goto out_unlock;
+	nfs_layoutget_begin(lo);
+	spin_unlock(&ino->i_lock);
+	_add_to_server_list(lo, NFS_SERVER(ino));
+	return lo;
+
+out_unlock:
+	spin_unlock(&ino->i_lock);
+	pnfs_put_layout_hdr(lo);
+	return NULL;
+}
+
+static void _lgopen_prepare_attached(struct nfs4_opendata *data,
+				     struct nfs_open_context *ctx)
+{
+	struct inode *ino = data->dentry->d_inode;
+	struct pnfs_layout_range rng = {
+		.iomode = (data->o_arg.fmode & FMODE_WRITE) ?
+			  IOMODE_RW: IOMODE_READ,
+		.offset = 0,
+		.length = NFS4_MAX_UINT64,
+	};
+	struct nfs4_layoutget *lgp;
+	struct pnfs_layout_hdr *lo;
+
+	/* Heuristic: don't send layoutget if we have cached data */
+	if (rng.iomode == IOMODE_READ &&
+	   (i_size_read(ino) == 0 || ino->i_mapping->nrpages != 0))
+		return;
+
+	lo = _pnfs_grab_empty_layout(ino, ctx);
+	if (!lo)
+		return;
+	lgp = pnfs_alloc_init_layoutget_args(ino, ctx, &current_stateid,
+					     &rng, GFP_KERNEL);
+	if (!lgp) {
+		pnfs_clear_first_layoutget(lo);
+		nfs_layoutget_end(lo);
+		pnfs_put_layout_hdr(lo);
+		return;
+	}
+	data->lgp = lgp;
+	data->o_arg.lg_args = &lgp->args;
+	data->o_res.lg_res = &lgp->res;
+}
+
+static void _lgopen_prepare_floating(struct nfs4_opendata *data,
+				     struct nfs_open_context *ctx)
+{
+	struct pnfs_layout_range rng = {
+		.iomode = (data->o_arg.fmode & FMODE_WRITE) ?
+			  IOMODE_RW: IOMODE_READ,
+		.offset = 0,
+		.length = NFS4_MAX_UINT64,
+	};
+	struct nfs4_layoutget *lgp;
+
+	lgp = pnfs_alloc_init_layoutget_args(NULL, ctx, &current_stateid,
+					     &rng, GFP_KERNEL);
+	if (!lgp)
+		return;
+	data->lgp = lgp;
+	data->o_arg.lg_args = &lgp->args;
+	data->o_res.lg_res = &lgp->res;
+}
+
+void pnfs_lgopen_prepare(struct nfs4_opendata *data,
+			 struct nfs_open_context *ctx)
+{
+	struct nfs_server *server = NFS_SERVER(data->dir->d_inode);
+
+	if (!(pnfs_enabled_sb(server) &&
+	      server->pnfs_curr_ld->flags & PNFS_LAYOUTGET_ON_OPEN))
+		return;
+	/* Could check on max_ops, but currently hardcoded high enough */
+	if (!nfs_server_capable(data->dir->d_inode, NFS_CAP_LGOPEN))
+		return;
+	if (data->state)
+		_lgopen_prepare_attached(data, ctx);
+	else
+		_lgopen_prepare_floating(data, ctx);
+}
+
+void pnfs_parse_lgopen(struct inode *ino, struct nfs4_layoutget *lgp,
+		       struct nfs_open_context *ctx)
+{
+	struct pnfs_layout_hdr *lo;
+	struct pnfs_layout_segment *lseg;
+	struct nfs_server *srv = NFS_SERVER(ino);
+	u32 iomode;
+
+	if (!lgp)
+		return;
+	dprintk("%s: entered with status %i\n", __func__, lgp->res.status);
+	if (lgp->res.status) {
+		switch (lgp->res.status) {
+		default:
+			break;
+		/*
+		 * Halt lgopen attempts if the server doesn't recognise
+		 * the "current stateid" value, the layout type, or the
+		 * layoutget operation as being valid.
+		 * Also if it complains about too many ops in the compound
+		 * or of the request/reply being too big.
+		 */
+		case -NFS4ERR_BAD_STATEID:
+		case -NFS4ERR_NOTSUPP:
+		case -NFS4ERR_REP_TOO_BIG:
+		case -NFS4ERR_REP_TOO_BIG_TO_CACHE:
+		case -NFS4ERR_REQ_TOO_BIG:
+		case -NFS4ERR_TOO_MANY_OPS:
+		case -NFS4ERR_UNKNOWN_LAYOUTTYPE:
+			srv->caps &= ~NFS_CAP_LGOPEN;
+		}
+		return;
+	}
+	if (!lgp->args.inode) {
+		lo = _pnfs_grab_empty_layout(ino, ctx);
+		if (!lo)
+			return;
+		lgp->args.inode = ino;
+	} else
+		lo = NFS_I(lgp->args.inode)->layout;
+
+	lseg = pnfs_layout_process(lgp);
+	if (!IS_ERR(lseg)) {
+		iomode = lgp->args.range.iomode;
+		pnfs_layout_clear_fail_bit(lo, pnfs_iomode_to_fail_bit(iomode));
+		pnfs_put_lseg(lseg);
+	}
+}
+
+void nfs4_lgopen_release(struct nfs4_layoutget *lgp)
+{
+	if (lgp != NULL) {
+		struct inode *inode = lgp->args.inode;
+		if (inode) {
+			struct pnfs_layout_hdr *lo = NFS_I(inode)->layout;
+			pnfs_clear_first_layoutget(lo);
+			nfs_layoutget_end(lo);
+		}
+		pnfs_layoutget_free(lgp);
+	}
+}
+
+struct pnfs_layout_segment *
+pnfs_layout_process(struct nfs4_layoutget *lgp)
+{
+	struct pnfs_layout_hdr *lo = NFS_I(lgp->args.inode)->layout;
+	struct nfs4_layoutget_res *res = &lgp->res;
+	struct pnfs_layout_segment *lseg;
+	struct inode *ino = lo->plh_inode;
+	LIST_HEAD(free_me);
+
+	if (!pnfs_sanity_check_layout_range(&res->range))
+		return ERR_PTR(-EINVAL);
+
+	/* Inject layout blob into I/O device driver */
+	lseg = NFS_SERVER(ino)->pnfs_curr_ld->alloc_lseg(lo, res, lgp->gfp_flags);
+	if (IS_ERR_OR_NULL(lseg)) {
+		if (!lseg)
+			lseg = ERR_PTR(-ENOMEM);
+
+		dprintk("%s: Could not allocate layout: error %ld\n",
+		       __func__, PTR_ERR(lseg));
+		return lseg;
+	}
+
+	pnfs_init_lseg(lo, lseg, &res->range, &res->stateid);
+
+	spin_lock(&ino->i_lock);
+	if (pnfs_layoutgets_blocked(lo)) {
+		dprintk("%s forget reply due to state\n", __func__);
+		goto out_forget;
+	}
+
+	if (test_bit(NFS_LAYOUT_DRAIN, &lo->plh_flags) &&
+	    !pnfs_is_first_layoutget(lo))
+		goto out_forget;
+
+	if (nfs4_stateid_match_other(&lo->plh_stateid, &res->stateid)) {
+		/* existing state ID, make sure the sequence number matches. */
+		if (pnfs_layout_stateid_blocked(lo, &res->stateid)) {
+			if (!pnfs_layout_is_valid(lo))
+				lo->plh_barrier = 0;
+			dprintk("%s forget reply due to sequence\n", __func__);
+			goto out_forget;
+		}
+		pnfs_set_layout_stateid(lo, &res->stateid, lgp->cred, false);
+	} else if (pnfs_layout_is_valid(lo)) {
+		/*
+		 * We got an entirely new state ID.  Mark all segments for the
+		 * inode invalid, and retry the layoutget
+		 */
+		struct pnfs_layout_range range = {
+			.iomode = IOMODE_ANY,
+			.length = NFS4_MAX_UINT64,
+		};
+		pnfs_set_plh_return_info(lo, IOMODE_ANY, 0);
+		pnfs_mark_matching_lsegs_return(lo, &lo->plh_return_segs,
+						&range, 0);
+		goto out_forget;
+	} else {
+		/* We have a completely new layout */
+		pnfs_set_layout_stateid(lo, &res->stateid, lgp->cred, true);
+	}
+
+	pnfs_get_lseg(lseg);
+	pnfs_layout_insert_lseg(lo, lseg, &free_me);
+
+
+	if (res->return_on_close)
+		set_bit(NFS_LSEG_ROC, &lseg->pls_flags);
+
+	spin_unlock(&ino->i_lock);
+	pnfs_free_lseg_list(&free_me);
+	return lseg;
+
+out_forget:
+	spin_unlock(&ino->i_lock);
+	lseg->pls_layout = lo;
+	NFS_SERVER(ino)->pnfs_curr_ld->free_lseg(lseg);
+	pnfs_free_lseg_list(&free_me);
+	return ERR_PTR(-EAGAIN);
+}
+
+/**
+ * pnfs_mark_matching_lsegs_return - Free or return matching layout segments
+ * @lo: pointer to layout header
+ * @tmp_list: list header to be used with pnfs_free_lseg_list()
+ * @return_range: describe layout segment ranges to be returned
+ * @seq: stateid seqid to match
+ *
+ * This function is mainly intended for use by layoutrecall. It attempts
+ * to free the layout segment immediately, or else to mark it for return
+ * as soon as its reference count drops to zero.
+ *
+ * Returns
+ * - 0: a layoutreturn needs to be scheduled.
+ * - EBUSY: there are layout segment that are still in use.
+ * - ENOENT: there are no layout segments that need to be returned.
+ */
+int
+pnfs_mark_matching_lsegs_return(struct pnfs_layout_hdr *lo,
+				struct list_head *tmp_list,
+				const struct pnfs_layout_range *return_range,
+				u32 seq)
+{
+	struct pnfs_layout_segment *lseg, *next;
+	int remaining = 0;
+
+	dprintk("%s:Begin lo %p\n", __func__, lo);
+
+	assert_spin_locked(&lo->plh_inode->i_lock);
+
+	if (test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags))
+		tmp_list = &lo->plh_return_segs;
+
+	list_for_each_entry_safe(lseg, next, &lo->plh_segs, pls_list)
+		if (pnfs_match_lseg_recall(lseg, return_range, seq)) {
+			dprintk("%s: marking lseg %p iomode %d "
+				"offset %llu length %llu\n", __func__,
+				lseg, lseg->pls_range.iomode,
+				lseg->pls_range.offset,
+				lseg->pls_range.length);
+			if (test_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags))
+				tmp_list = &lo->plh_return_segs;
+			if (mark_lseg_invalid(lseg, tmp_list))
+				continue;
+			remaining++;
+			set_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags);
+		}
+
+	if (remaining) {
+		pnfs_set_plh_return_info(lo, return_range->iomode, seq);
+		return -EBUSY;
+	}
+
+	if (!list_empty(&lo->plh_return_segs)) {
+		pnfs_set_plh_return_info(lo, return_range->iomode, seq);
+		return 0;
+	}
+
+	return -ENOENT;
+}
+
+static void
+pnfs_mark_layout_for_return(struct inode *inode,
+			    const struct pnfs_layout_range *range)
+{
+	struct pnfs_layout_hdr *lo;
+	bool return_now = false;
+
+	spin_lock(&inode->i_lock);
+	lo = NFS_I(inode)->layout;
+	if (!pnfs_layout_is_valid(lo)) {
+		spin_unlock(&inode->i_lock);
+		return;
+	}
+	pnfs_set_plh_return_info(lo, range->iomode, 0);
+	/*
+	 * mark all matching lsegs so that we are sure to have no live
+	 * segments at hand when sending layoutreturn. See pnfs_put_lseg()
+	 * for how it works.
+	 */
+	if (pnfs_mark_matching_lsegs_return(lo, &lo->plh_return_segs, range, 0) != -EBUSY) {
+		const struct cred *cred;
+		nfs4_stateid stateid;
+		enum pnfs_iomode iomode;
+
+		return_now = pnfs_prepare_layoutreturn(lo, &stateid, &cred, &iomode);
+		spin_unlock(&inode->i_lock);
+		if (return_now)
+			pnfs_send_layoutreturn(lo, &stateid, &cred, iomode, false);
+	} else {
+		spin_unlock(&inode->i_lock);
+		nfs_commit_inode(inode, 0);
+	}
+}
+
+void pnfs_error_mark_layout_for_return(struct inode *inode,
+				       struct pnfs_layout_segment *lseg)
+{
+	struct pnfs_layout_range range = {
+		.iomode = lseg->pls_range.iomode,
+		.offset = 0,
+		.length = NFS4_MAX_UINT64,
+	};
+
+	pnfs_mark_layout_for_return(inode, &range);
+}
+EXPORT_SYMBOL_GPL(pnfs_error_mark_layout_for_return);
+
+static bool
+pnfs_layout_can_be_returned(struct pnfs_layout_hdr *lo)
+{
+	return pnfs_layout_is_valid(lo) &&
+		!test_bit(NFS_LAYOUT_INODE_FREEING, &lo->plh_flags) &&
+		!test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags);
+}
+
+static struct pnfs_layout_segment *
+pnfs_find_first_lseg(struct pnfs_layout_hdr *lo,
+		     const struct pnfs_layout_range *range,
+		     enum pnfs_iomode iomode)
+{
+	struct pnfs_layout_segment *lseg;
+
+	list_for_each_entry(lseg, &lo->plh_segs, pls_list) {
+		if (!test_bit(NFS_LSEG_VALID, &lseg->pls_flags))
+			continue;
+		if (test_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags))
+			continue;
+		if (lseg->pls_range.iomode != iomode && iomode != IOMODE_ANY)
+			continue;
+		if (pnfs_lseg_range_intersecting(&lseg->pls_range, range))
+			return lseg;
+	}
+	return NULL;
+}
+
+/* Find open file states whose mode matches that of the range */
+static bool
+pnfs_should_return_unused_layout(struct pnfs_layout_hdr *lo,
+				 const struct pnfs_layout_range *range)
+{
+	struct list_head *head;
+	struct nfs_open_context *ctx;
+	fmode_t mode = 0;
+
+	if (!pnfs_layout_can_be_returned(lo) ||
+	    !pnfs_find_first_lseg(lo, range, range->iomode))
+		return false;
+
+	head = &NFS_I(lo->plh_inode)->open_files;
+	list_for_each_entry_rcu(ctx, head, list) {
+		if (ctx->state)
+			mode |= ctx->state->state & (FMODE_READ|FMODE_WRITE);
+	}
+
+	switch (range->iomode) {
+	default:
+		break;
+	case IOMODE_READ:
+		mode &= ~FMODE_WRITE;
+		break;
+	case IOMODE_RW:
+		if (pnfs_find_first_lseg(lo, range, IOMODE_READ))
+			mode &= ~FMODE_READ;
+	}
+	return mode == 0;
+}
+
+static int pnfs_layout_return_unused_byserver(struct nfs_server *server,
+					      void *data)
+{
+	const struct pnfs_layout_range *range = data;
+	const struct cred *cred;
+	struct pnfs_layout_hdr *lo;
+	struct inode *inode;
+	nfs4_stateid stateid;
+	enum pnfs_iomode iomode;
+
+restart:
+	rcu_read_lock();
+	list_for_each_entry_rcu(lo, &server->layouts, plh_layouts) {
+		inode = lo->plh_inode;
+		if (!inode || !pnfs_layout_can_be_returned(lo) ||
+		    test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags))
+			continue;
+		spin_lock(&inode->i_lock);
+		if (!lo->plh_inode ||
+		    !pnfs_should_return_unused_layout(lo, range)) {
+			spin_unlock(&inode->i_lock);
+			continue;
+		}
+		pnfs_get_layout_hdr(lo);
+		pnfs_set_plh_return_info(lo, range->iomode, 0);
+		if (pnfs_mark_matching_lsegs_return(lo, &lo->plh_return_segs,
+						    range, 0) != 0 ||
+		    !pnfs_prepare_layoutreturn(lo, &stateid, &cred, &iomode)) {
+			spin_unlock(&inode->i_lock);
+			rcu_read_unlock();
+			pnfs_put_layout_hdr(lo);
+			cond_resched();
+			goto restart;
+		}
+		spin_unlock(&inode->i_lock);
+		rcu_read_unlock();
+		pnfs_send_layoutreturn(lo, &stateid, &cred, iomode, false);
+		pnfs_put_layout_hdr(lo);
+		cond_resched();
+		goto restart;
+	}
+	rcu_read_unlock();
+	return 0;
+}
+
+void
+pnfs_layout_return_unused_byclid(struct nfs_client *clp,
+				 enum pnfs_iomode iomode)
+{
+	struct pnfs_layout_range range = {
+		.iomode = iomode,
+		.offset = 0,
+		.length = NFS4_MAX_UINT64,
+	};
+
+	nfs_client_for_each_server(clp, pnfs_layout_return_unused_byserver,
+			&range);
+}
+
+void
+pnfs_generic_pg_check_layout(struct nfs_pageio_descriptor *pgio)
+{
+	if (pgio->pg_lseg == NULL ||
+	    test_bit(NFS_LSEG_VALID, &pgio->pg_lseg->pls_flags))
+		return;
+	pnfs_put_lseg(pgio->pg_lseg);
+	pgio->pg_lseg = NULL;
+}
+EXPORT_SYMBOL_GPL(pnfs_generic_pg_check_layout);
+
+/*
+ * Check for any intersection between the request and the pgio->pg_lseg,
+ * and if none, put this pgio->pg_lseg away.
+ */
+void
+pnfs_generic_pg_check_range(struct nfs_pageio_descriptor *pgio, struct nfs_page *req)
+{
+	if (pgio->pg_lseg && !pnfs_lseg_request_intersecting(pgio->pg_lseg, req)) {
+		pnfs_put_lseg(pgio->pg_lseg);
+		pgio->pg_lseg = NULL;
+	}
+}
+EXPORT_SYMBOL_GPL(pnfs_generic_pg_check_range);
+
+void
+pnfs_generic_pg_init_read(struct nfs_pageio_descriptor *pgio, struct nfs_page *req)
+{
+	u64 rd_size = req->wb_bytes;
+
+	pnfs_generic_pg_check_layout(pgio);
+	pnfs_generic_pg_check_range(pgio, req);
+	if (pgio->pg_lseg == NULL) {
+		if (pgio->pg_dreq == NULL)
+			rd_size = i_size_read(pgio->pg_inode) - req_offset(req);
+		else
+			rd_size = nfs_dreq_bytes_left(pgio->pg_dreq);
+
+		pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
+						   nfs_req_openctx(req),
+						   req_offset(req),
+						   rd_size,
+						   IOMODE_READ,
+						   false,
+						   GFP_KERNEL);
+		if (IS_ERR(pgio->pg_lseg)) {
+			pgio->pg_error = PTR_ERR(pgio->pg_lseg);
+			pgio->pg_lseg = NULL;
+			return;
+		}
+	}
+	/* If no lseg, fall back to read through mds */
+	if (pgio->pg_lseg == NULL)
+		nfs_pageio_reset_read_mds(pgio);
+
+}
+EXPORT_SYMBOL_GPL(pnfs_generic_pg_init_read);
+
+void
+pnfs_generic_pg_init_write(struct nfs_pageio_descriptor *pgio,
+			   struct nfs_page *req, u64 wb_size)
+{
+	pnfs_generic_pg_check_layout(pgio);
+	pnfs_generic_pg_check_range(pgio, req);
+	if (pgio->pg_lseg == NULL) {
+		pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
+						   nfs_req_openctx(req),
+						   req_offset(req),
+						   wb_size,
+						   IOMODE_RW,
+						   false,
+						   GFP_KERNEL);
+		if (IS_ERR(pgio->pg_lseg)) {
+			pgio->pg_error = PTR_ERR(pgio->pg_lseg);
+			pgio->pg_lseg = NULL;
+			return;
+		}
+	}
+	/* If no lseg, fall back to write through mds */
+	if (pgio->pg_lseg == NULL)
+		nfs_pageio_reset_write_mds(pgio);
+}
+EXPORT_SYMBOL_GPL(pnfs_generic_pg_init_write);
+
+void
+pnfs_generic_pg_cleanup(struct nfs_pageio_descriptor *desc)
+{
+	if (desc->pg_lseg) {
+		pnfs_put_lseg(desc->pg_lseg);
+		desc->pg_lseg = NULL;
+	}
+}
+EXPORT_SYMBOL_GPL(pnfs_generic_pg_cleanup);
+
+/*
+ * Return 0 if @req cannot be coalesced into @pgio, otherwise return the number
+ * of bytes (maximum @req->wb_bytes) that can be coalesced.
+ */
+size_t
+pnfs_generic_pg_test(struct nfs_pageio_descriptor *pgio,
+		     struct nfs_page *prev, struct nfs_page *req)
+{
+	unsigned int size;
+	u64 seg_end, req_start, seg_left;
+
+	size = nfs_generic_pg_test(pgio, prev, req);
+	if (!size)
+		return 0;
+
+	/*
+	 * 'size' contains the number of bytes left in the current page (up
+	 * to the original size asked for in @req->wb_bytes).
+	 *
+	 * Calculate how many bytes are left in the layout segment
+	 * and if there are less bytes than 'size', return that instead.
+	 *
+	 * Please also note that 'end_offset' is actually the offset of the
+	 * first byte that lies outside the pnfs_layout_range. FIXME?
+	 *
+	 */
+	if (pgio->pg_lseg) {
+		seg_end = pnfs_end_offset(pgio->pg_lseg->pls_range.offset,
+				     pgio->pg_lseg->pls_range.length);
+		req_start = req_offset(req);
+
+		/* start of request is past the last byte of this segment */
+		if (req_start >= seg_end)
+			return 0;
+
+		/* adjust 'size' iff there are fewer bytes left in the
+		 * segment than what nfs_generic_pg_test returned */
+		seg_left = seg_end - req_start;
+		if (seg_left < size)
+			size = (unsigned int)seg_left;
+	}
+
+	return size;
+}
+EXPORT_SYMBOL_GPL(pnfs_generic_pg_test);
+
+int pnfs_write_done_resend_to_mds(struct nfs_pgio_header *hdr)
+{
+	struct nfs_pageio_descriptor pgio;
+
+	/* Resend all requests through the MDS */
+	nfs_pageio_init_write(&pgio, hdr->inode, FLUSH_STABLE, true,
+			      hdr->completion_ops);
+	set_bit(NFS_CONTEXT_RESEND_WRITES, &hdr->args.context->flags);
+	return nfs_pageio_resend(&pgio, hdr);
+}
+EXPORT_SYMBOL_GPL(pnfs_write_done_resend_to_mds);
+
+static void pnfs_ld_handle_write_error(struct nfs_pgio_header *hdr)
+{
+
+	dprintk("pnfs write error = %d\n", hdr->pnfs_error);
+	if (NFS_SERVER(hdr->inode)->pnfs_curr_ld->flags &
+	    PNFS_LAYOUTRET_ON_ERROR) {
+		pnfs_return_layout(hdr->inode);
+	}
+	if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags))
+		hdr->task.tk_status = pnfs_write_done_resend_to_mds(hdr);
+}
+
+/*
+ * Called by non rpc-based layout drivers
+ */
+void pnfs_ld_write_done(struct nfs_pgio_header *hdr)
+{
+	if (likely(!hdr->pnfs_error)) {
+		pnfs_set_layoutcommit(hdr->inode, hdr->lseg,
+				hdr->mds_offset + hdr->res.count);
+		hdr->mds_ops->rpc_call_done(&hdr->task, hdr);
+	}
+	trace_nfs4_pnfs_write(hdr, hdr->pnfs_error);
+	if (unlikely(hdr->pnfs_error))
+		pnfs_ld_handle_write_error(hdr);
+	hdr->mds_ops->rpc_release(hdr);
+}
+EXPORT_SYMBOL_GPL(pnfs_ld_write_done);
+
+static void
+pnfs_write_through_mds(struct nfs_pageio_descriptor *desc,
+		struct nfs_pgio_header *hdr)
+{
+	struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
+
+	if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
+		list_splice_tail_init(&hdr->pages, &mirror->pg_list);
+		nfs_pageio_reset_write_mds(desc);
+		mirror->pg_recoalesce = 1;
+	}
+	hdr->completion_ops->completion(hdr);
+}
+
+static enum pnfs_try_status
+pnfs_try_to_write_data(struct nfs_pgio_header *hdr,
+			const struct rpc_call_ops *call_ops,
+			struct pnfs_layout_segment *lseg,
+			int how)
+{
+	struct inode *inode = hdr->inode;
+	enum pnfs_try_status trypnfs;
+	struct nfs_server *nfss = NFS_SERVER(inode);
+
+	hdr->mds_ops = call_ops;
+
+	dprintk("%s: Writing ino:%lu %u@%llu (how %d)\n", __func__,
+		inode->i_ino, hdr->args.count, hdr->args.offset, how);
+	trypnfs = nfss->pnfs_curr_ld->write_pagelist(hdr, how);
+	if (trypnfs != PNFS_NOT_ATTEMPTED)
+		nfs_inc_stats(inode, NFSIOS_PNFS_WRITE);
+	dprintk("%s End (trypnfs:%d)\n", __func__, trypnfs);
+	return trypnfs;
+}
+
+static void
+pnfs_do_write(struct nfs_pageio_descriptor *desc,
+	      struct nfs_pgio_header *hdr, int how)
+{
+	const struct rpc_call_ops *call_ops = desc->pg_rpc_callops;
+	struct pnfs_layout_segment *lseg = desc->pg_lseg;
+	enum pnfs_try_status trypnfs;
+
+	trypnfs = pnfs_try_to_write_data(hdr, call_ops, lseg, how);
+	switch (trypnfs) {
+	case PNFS_NOT_ATTEMPTED:
+		pnfs_write_through_mds(desc, hdr);
+	case PNFS_ATTEMPTED:
+		break;
+	case PNFS_TRY_AGAIN:
+		/* cleanup hdr and prepare to redo pnfs */
+		if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
+			struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
+			list_splice_init(&hdr->pages, &mirror->pg_list);
+			mirror->pg_recoalesce = 1;
+		}
+		hdr->mds_ops->rpc_release(hdr);
+	}
+}
+
+static void pnfs_writehdr_free(struct nfs_pgio_header *hdr)
+{
+	pnfs_put_lseg(hdr->lseg);
+	nfs_pgio_header_free(hdr);
+}
+
+int
+pnfs_generic_pg_writepages(struct nfs_pageio_descriptor *desc)
+{
+	struct nfs_pgio_header *hdr;
+	int ret;
+
+	hdr = nfs_pgio_header_alloc(desc->pg_rw_ops);
+	if (!hdr) {
+		desc->pg_error = -ENOMEM;
+		return desc->pg_error;
+	}
+	nfs_pgheader_init(desc, hdr, pnfs_writehdr_free);
+
+	hdr->lseg = pnfs_get_lseg(desc->pg_lseg);
+	ret = nfs_generic_pgio(desc, hdr);
+	if (!ret)
+		pnfs_do_write(desc, hdr, desc->pg_ioflags);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(pnfs_generic_pg_writepages);
+
+int pnfs_read_done_resend_to_mds(struct nfs_pgio_header *hdr)
+{
+	struct nfs_pageio_descriptor pgio;
+
+	/* Resend all requests through the MDS */
+	nfs_pageio_init_read(&pgio, hdr->inode, true, hdr->completion_ops);
+	return nfs_pageio_resend(&pgio, hdr);
+}
+EXPORT_SYMBOL_GPL(pnfs_read_done_resend_to_mds);
+
+static void pnfs_ld_handle_read_error(struct nfs_pgio_header *hdr)
+{
+	dprintk("pnfs read error = %d\n", hdr->pnfs_error);
+	if (NFS_SERVER(hdr->inode)->pnfs_curr_ld->flags &
+	    PNFS_LAYOUTRET_ON_ERROR) {
+		pnfs_return_layout(hdr->inode);
+	}
+	if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags))
+		hdr->task.tk_status = pnfs_read_done_resend_to_mds(hdr);
+}
+
+/*
+ * Called by non rpc-based layout drivers
+ */
+void pnfs_ld_read_done(struct nfs_pgio_header *hdr)
+{
+	if (likely(!hdr->pnfs_error))
+		hdr->mds_ops->rpc_call_done(&hdr->task, hdr);
+	trace_nfs4_pnfs_read(hdr, hdr->pnfs_error);
+	if (unlikely(hdr->pnfs_error))
+		pnfs_ld_handle_read_error(hdr);
+	hdr->mds_ops->rpc_release(hdr);
+}
+EXPORT_SYMBOL_GPL(pnfs_ld_read_done);
+
+static void
+pnfs_read_through_mds(struct nfs_pageio_descriptor *desc,
+		struct nfs_pgio_header *hdr)
+{
+	struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
+
+	if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
+		list_splice_tail_init(&hdr->pages, &mirror->pg_list);
+		nfs_pageio_reset_read_mds(desc);
+		mirror->pg_recoalesce = 1;
+	}
+	hdr->completion_ops->completion(hdr);
+}
+
+/*
+ * Call the appropriate parallel I/O subsystem read function.
+ */
+static enum pnfs_try_status
+pnfs_try_to_read_data(struct nfs_pgio_header *hdr,
+		       const struct rpc_call_ops *call_ops,
+		       struct pnfs_layout_segment *lseg)
+{
+	struct inode *inode = hdr->inode;
+	struct nfs_server *nfss = NFS_SERVER(inode);
+	enum pnfs_try_status trypnfs;
+
+	hdr->mds_ops = call_ops;
+
+	dprintk("%s: Reading ino:%lu %u@%llu\n",
+		__func__, inode->i_ino, hdr->args.count, hdr->args.offset);
+
+	trypnfs = nfss->pnfs_curr_ld->read_pagelist(hdr);
+	if (trypnfs != PNFS_NOT_ATTEMPTED)
+		nfs_inc_stats(inode, NFSIOS_PNFS_READ);
+	dprintk("%s End (trypnfs:%d)\n", __func__, trypnfs);
+	return trypnfs;
+}
+
+/* Resend all requests through pnfs. */
+void pnfs_read_resend_pnfs(struct nfs_pgio_header *hdr,
+			   unsigned int mirror_idx)
+{
+	struct nfs_pageio_descriptor pgio;
+
+	if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
+		/* Prevent deadlocks with layoutreturn! */
+		pnfs_put_lseg(hdr->lseg);
+		hdr->lseg = NULL;
+
+		nfs_pageio_init_read(&pgio, hdr->inode, false,
+					hdr->completion_ops);
+		pgio.pg_mirror_idx = mirror_idx;
+		hdr->task.tk_status = nfs_pageio_resend(&pgio, hdr);
+	}
+}
+EXPORT_SYMBOL_GPL(pnfs_read_resend_pnfs);
+
+static void
+pnfs_do_read(struct nfs_pageio_descriptor *desc, struct nfs_pgio_header *hdr)
+{
+	const struct rpc_call_ops *call_ops = desc->pg_rpc_callops;
+	struct pnfs_layout_segment *lseg = desc->pg_lseg;
+	enum pnfs_try_status trypnfs;
+
+	trypnfs = pnfs_try_to_read_data(hdr, call_ops, lseg);
+	switch (trypnfs) {
+	case PNFS_NOT_ATTEMPTED:
+		pnfs_read_through_mds(desc, hdr);
+	case PNFS_ATTEMPTED:
+		break;
+	case PNFS_TRY_AGAIN:
+		/* cleanup hdr and prepare to redo pnfs */
+		if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
+			struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
+			list_splice_init(&hdr->pages, &mirror->pg_list);
+			mirror->pg_recoalesce = 1;
+		}
+		hdr->mds_ops->rpc_release(hdr);
+	}
+}
+
+static void pnfs_readhdr_free(struct nfs_pgio_header *hdr)
+{
+	pnfs_put_lseg(hdr->lseg);
+	nfs_pgio_header_free(hdr);
+}
+
+int
+pnfs_generic_pg_readpages(struct nfs_pageio_descriptor *desc)
+{
+	struct nfs_pgio_header *hdr;
+	int ret;
+
+	hdr = nfs_pgio_header_alloc(desc->pg_rw_ops);
+	if (!hdr) {
+		desc->pg_error = -ENOMEM;
+		return desc->pg_error;
+	}
+	nfs_pgheader_init(desc, hdr, pnfs_readhdr_free);
+	hdr->lseg = pnfs_get_lseg(desc->pg_lseg);
+	ret = nfs_generic_pgio(desc, hdr);
+	if (!ret)
+		pnfs_do_read(desc, hdr);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(pnfs_generic_pg_readpages);
+
+static void pnfs_clear_layoutcommitting(struct inode *inode)
+{
+	unsigned long *bitlock = &NFS_I(inode)->flags;
+
+	clear_bit_unlock(NFS_INO_LAYOUTCOMMITTING, bitlock);
+	smp_mb__after_atomic();
+	wake_up_bit(bitlock, NFS_INO_LAYOUTCOMMITTING);
+}
+
+/*
+ * There can be multiple RW segments.
+ */
+static void pnfs_list_write_lseg(struct inode *inode, struct list_head *listp)
+{
+	struct pnfs_layout_segment *lseg;
+
+	list_for_each_entry(lseg, &NFS_I(inode)->layout->plh_segs, pls_list) {
+		if (lseg->pls_range.iomode == IOMODE_RW &&
+		    test_and_clear_bit(NFS_LSEG_LAYOUTCOMMIT, &lseg->pls_flags))
+			list_add(&lseg->pls_lc_list, listp);
+	}
+}
+
+static void pnfs_list_write_lseg_done(struct inode *inode, struct list_head *listp)
+{
+	struct pnfs_layout_segment *lseg, *tmp;
+
+	/* Matched by references in pnfs_set_layoutcommit */
+	list_for_each_entry_safe(lseg, tmp, listp, pls_lc_list) {
+		list_del_init(&lseg->pls_lc_list);
+		pnfs_put_lseg(lseg);
+	}
+
+	pnfs_clear_layoutcommitting(inode);
+}
+
+void pnfs_set_lo_fail(struct pnfs_layout_segment *lseg)
+{
+	pnfs_layout_io_set_failed(lseg->pls_layout, lseg->pls_range.iomode);
+}
+EXPORT_SYMBOL_GPL(pnfs_set_lo_fail);
+
+void
+pnfs_set_layoutcommit(struct inode *inode, struct pnfs_layout_segment *lseg,
+		loff_t end_pos)
+{
+	struct nfs_inode *nfsi = NFS_I(inode);
+	bool mark_as_dirty = false;
+
+	spin_lock(&inode->i_lock);
+	if (!test_and_set_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags)) {
+		nfsi->layout->plh_lwb = end_pos;
+		mark_as_dirty = true;
+		dprintk("%s: Set layoutcommit for inode %lu ",
+			__func__, inode->i_ino);
+	} else if (end_pos > nfsi->layout->plh_lwb)
+		nfsi->layout->plh_lwb = end_pos;
+	if (!test_and_set_bit(NFS_LSEG_LAYOUTCOMMIT, &lseg->pls_flags)) {
+		/* references matched in nfs4_layoutcommit_release */
+		pnfs_get_lseg(lseg);
+	}
+	spin_unlock(&inode->i_lock);
+	dprintk("%s: lseg %p end_pos %llu\n",
+		__func__, lseg, nfsi->layout->plh_lwb);
+
+	/* if pnfs_layoutcommit_inode() runs between inode locks, the next one
+	 * will be a noop because NFS_INO_LAYOUTCOMMIT will not be set */
+	if (mark_as_dirty)
+		mark_inode_dirty_sync(inode);
+}
+EXPORT_SYMBOL_GPL(pnfs_set_layoutcommit);
+
+void pnfs_cleanup_layoutcommit(struct nfs4_layoutcommit_data *data)
+{
+	struct nfs_server *nfss = NFS_SERVER(data->args.inode);
+
+	if (nfss->pnfs_curr_ld->cleanup_layoutcommit)
+		nfss->pnfs_curr_ld->cleanup_layoutcommit(data);
+	pnfs_list_write_lseg_done(data->args.inode, &data->lseg_list);
+}
+
+/*
+ * For the LAYOUT4_NFSV4_1_FILES layout type, NFS_DATA_SYNC WRITEs and
+ * NFS_UNSTABLE WRITEs with a COMMIT to data servers must store enough
+ * data to disk to allow the server to recover the data if it crashes.
+ * LAYOUTCOMMIT is only needed when the NFL4_UFLG_COMMIT_THRU_MDS flag
+ * is off, and a COMMIT is sent to a data server, or
+ * if WRITEs to a data server return NFS_DATA_SYNC.
+ */
+int
+pnfs_layoutcommit_inode(struct inode *inode, bool sync)
+{
+	struct pnfs_layoutdriver_type *ld = NFS_SERVER(inode)->pnfs_curr_ld;
+	struct nfs4_layoutcommit_data *data;
+	struct nfs_inode *nfsi = NFS_I(inode);
+	loff_t end_pos;
+	int status;
+
+	if (!pnfs_layoutcommit_outstanding(inode))
+		return 0;
+
+	dprintk("--> %s inode %lu\n", __func__, inode->i_ino);
+
+	status = -EAGAIN;
+	if (test_and_set_bit(NFS_INO_LAYOUTCOMMITTING, &nfsi->flags)) {
+		if (!sync)
+			goto out;
+		status = wait_on_bit_lock_action(&nfsi->flags,
+				NFS_INO_LAYOUTCOMMITTING,
+				nfs_wait_bit_killable,
+				TASK_KILLABLE);
+		if (status)
+			goto out;
+	}
+
+	status = -ENOMEM;
+	/* Note kzalloc ensures data->res.seq_res.sr_slot == NULL */
+	data = kzalloc(sizeof(*data), GFP_NOFS);
+	if (!data)
+		goto clear_layoutcommitting;
+
+	status = 0;
+	spin_lock(&inode->i_lock);
+	if (!test_and_clear_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags))
+		goto out_unlock;
+
+	INIT_LIST_HEAD(&data->lseg_list);
+	pnfs_list_write_lseg(inode, &data->lseg_list);
+
+	end_pos = nfsi->layout->plh_lwb;
+
+	nfs4_stateid_copy(&data->args.stateid, &nfsi->layout->plh_stateid);
+	data->cred = get_cred(nfsi->layout->plh_lc_cred);
+	spin_unlock(&inode->i_lock);
+
+	data->args.inode = inode;
+	nfs_fattr_init(&data->fattr);
+	data->args.bitmask = NFS_SERVER(inode)->cache_consistency_bitmask;
+	data->res.fattr = &data->fattr;
+	if (end_pos != 0)
+		data->args.lastbytewritten = end_pos - 1;
+	else
+		data->args.lastbytewritten = U64_MAX;
+	data->res.server = NFS_SERVER(inode);
+
+	if (ld->prepare_layoutcommit) {
+		status = ld->prepare_layoutcommit(&data->args);
+		if (status) {
+			put_cred(data->cred);
+			spin_lock(&inode->i_lock);
+			set_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags);
+			if (end_pos > nfsi->layout->plh_lwb)
+				nfsi->layout->plh_lwb = end_pos;
+			goto out_unlock;
+		}
+	}
+
+
+	status = nfs4_proc_layoutcommit(data, sync);
+out:
+	if (status)
+		mark_inode_dirty_sync(inode);
+	dprintk("<-- %s status %d\n", __func__, status);
+	return status;
+out_unlock:
+	spin_unlock(&inode->i_lock);
+	kfree(data);
+clear_layoutcommitting:
+	pnfs_clear_layoutcommitting(inode);
+	goto out;
+}
+EXPORT_SYMBOL_GPL(pnfs_layoutcommit_inode);
+
+int
+pnfs_generic_sync(struct inode *inode, bool datasync)
+{
+	return pnfs_layoutcommit_inode(inode, true);
+}
+EXPORT_SYMBOL_GPL(pnfs_generic_sync);
+
+struct nfs4_threshold *pnfs_mdsthreshold_alloc(void)
+{
+	struct nfs4_threshold *thp;
+
+	thp = kzalloc(sizeof(*thp), GFP_NOFS);
+	if (!thp) {
+		dprintk("%s mdsthreshold allocation failed\n", __func__);
+		return NULL;
+	}
+	return thp;
+}
+
+#if IS_ENABLED(CONFIG_NFS_V4_2)
+int
+pnfs_report_layoutstat(struct inode *inode, gfp_t gfp_flags)
+{
+	struct pnfs_layoutdriver_type *ld = NFS_SERVER(inode)->pnfs_curr_ld;
+	struct nfs_server *server = NFS_SERVER(inode);
+	struct nfs_inode *nfsi = NFS_I(inode);
+	struct nfs42_layoutstat_data *data;
+	struct pnfs_layout_hdr *hdr;
+	int status = 0;
+
+	if (!pnfs_enabled_sb(server) || !ld->prepare_layoutstats)
+		goto out;
+
+	if (!nfs_server_capable(inode, NFS_CAP_LAYOUTSTATS))
+		goto out;
+
+	if (test_and_set_bit(NFS_INO_LAYOUTSTATS, &nfsi->flags))
+		goto out;
+
+	spin_lock(&inode->i_lock);
+	if (!NFS_I(inode)->layout) {
+		spin_unlock(&inode->i_lock);
+		goto out_clear_layoutstats;
+	}
+	hdr = NFS_I(inode)->layout;
+	pnfs_get_layout_hdr(hdr);
+	spin_unlock(&inode->i_lock);
+
+	data = kzalloc(sizeof(*data), gfp_flags);
+	if (!data) {
+		status = -ENOMEM;
+		goto out_put;
+	}
+
+	data->args.fh = NFS_FH(inode);
+	data->args.inode = inode;
+	status = ld->prepare_layoutstats(&data->args);
+	if (status)
+		goto out_free;
+
+	status = nfs42_proc_layoutstats_generic(NFS_SERVER(inode), data);
+
+out:
+	dprintk("%s returns %d\n", __func__, status);
+	return status;
+
+out_free:
+	kfree(data);
+out_put:
+	pnfs_put_layout_hdr(hdr);
+out_clear_layoutstats:
+	smp_mb__before_atomic();
+	clear_bit(NFS_INO_LAYOUTSTATS, &nfsi->flags);
+	smp_mb__after_atomic();
+	goto out;
+}
+EXPORT_SYMBOL_GPL(pnfs_report_layoutstat);
+#endif
+
+unsigned int layoutstats_timer;
+module_param(layoutstats_timer, uint, 0644);
+EXPORT_SYMBOL_GPL(layoutstats_timer);
diff --git a/fs/nfs/pnfs.h b/fs/nfs/pnfs.h
new file mode 100644
index 000000000..a7cf84a66
--- /dev/null
+++ b/fs/nfs/pnfs.h
@@ -0,0 +1,925 @@
+/*
+ *  pNFS client data structures.
+ *
+ *  Copyright (c) 2002
+ *  The Regents of the University of Michigan
+ *  All Rights Reserved
+ *
+ *  Dean Hildebrand <dhildebz@umich.edu>
+ *
+ *  Permission is granted to use, copy, create derivative works, and
+ *  redistribute this software and such derivative works for any purpose,
+ *  so long as the name of the University of Michigan is not used in
+ *  any advertising or publicity pertaining to the use or distribution
+ *  of this software without specific, written prior authorization. If
+ *  the above copyright notice or any other identification of the
+ *  University of Michigan is included in any copy of any portion of
+ *  this software, then the disclaimer below must also be included.
+ *
+ *  This software is provided as is, without representation or warranty
+ *  of any kind either express or implied, including without limitation
+ *  the implied warranties of merchantability, fitness for a particular
+ *  purpose, or noninfringement.  The Regents of the University of
+ *  Michigan shall not be liable for any damages, including special,
+ *  indirect, incidental, or consequential damages, with respect to any
+ *  claim arising out of or in connection with the use of the software,
+ *  even if it has been or is hereafter advised of the possibility of
+ *  such damages.
+ */
+
+#ifndef FS_NFS_PNFS_H
+#define FS_NFS_PNFS_H
+
+#include <linux/refcount.h>
+#include <linux/nfs_fs.h>
+#include <linux/nfs_page.h>
+#include <linux/workqueue.h>
+
+struct nfs4_opendata;
+
+enum {
+	NFS_LSEG_VALID = 0,	/* cleared when lseg is recalled/returned */
+	NFS_LSEG_ROC,		/* roc bit received from server */
+	NFS_LSEG_LAYOUTCOMMIT,	/* layoutcommit bit set for layoutcommit */
+	NFS_LSEG_LAYOUTRETURN,	/* layoutreturn bit set for layoutreturn */
+	NFS_LSEG_UNAVAILABLE,	/* unavailable bit set for temporary problem */
+};
+
+/* Individual ip address */
+struct nfs4_pnfs_ds_addr {
+	struct sockaddr_storage	da_addr;
+	size_t			da_addrlen;
+	struct list_head	da_node;  /* nfs4_pnfs_dev_hlist dev_dslist */
+	char			*da_remotestr;	/* human readable addr+port */
+};
+
+struct nfs4_pnfs_ds {
+	struct list_head	ds_node;  /* nfs4_pnfs_dev_hlist dev_dslist */
+	char			*ds_remotestr;	/* comma sep list of addrs */
+	struct list_head	ds_addrs;
+	struct nfs_client	*ds_clp;
+	refcount_t		ds_count;
+	unsigned long		ds_state;
+#define NFS4DS_CONNECTING	0	/* ds is establishing connection */
+};
+
+struct pnfs_layout_segment {
+	struct list_head pls_list;
+	struct list_head pls_lc_list;
+	struct list_head pls_commits;
+	struct pnfs_layout_range pls_range;
+	refcount_t pls_refcount;
+	u32 pls_seq;
+	unsigned long pls_flags;
+	struct pnfs_layout_hdr *pls_layout;
+};
+
+enum pnfs_try_status {
+	PNFS_ATTEMPTED     = 0,
+	PNFS_NOT_ATTEMPTED = 1,
+	PNFS_TRY_AGAIN     = 2,
+};
+
+/* error codes for internal use */
+#define NFS4ERR_RESET_TO_MDS   12001
+#define NFS4ERR_RESET_TO_PNFS  12002
+
+#ifdef CONFIG_NFS_V4_1
+
+#define LAYOUT_NFSV4_1_MODULE_PREFIX "nfs-layouttype4"
+
+/*
+ * Default data server connection timeout and retrans vaules.
+ * Set by module parameters dataserver_timeo and dataserver_retrans.
+ */
+#define NFS4_DEF_DS_TIMEO   600 /* in tenths of a second */
+#define NFS4_DEF_DS_RETRANS 5
+#define PNFS_DEVICE_RETRY_TIMEOUT (120*HZ)
+
+enum {
+	NFS_LAYOUT_RO_FAILED = 0,	/* get ro layout failed stop trying */
+	NFS_LAYOUT_RW_FAILED,		/* get rw layout failed stop trying */
+	NFS_LAYOUT_BULK_RECALL,		/* bulk recall affecting layout */
+	NFS_LAYOUT_RETURN,		/* layoutreturn in progress */
+	NFS_LAYOUT_RETURN_LOCK,		/* Serialise layoutreturn */
+	NFS_LAYOUT_RETURN_REQUESTED,	/* Return this layout ASAP */
+	NFS_LAYOUT_INVALID_STID,	/* layout stateid id is invalid */
+	NFS_LAYOUT_FIRST_LAYOUTGET,	/* Serialize first layoutget */
+	NFS_LAYOUT_INODE_FREEING,	/* The inode is being freed */
+	NFS_LAYOUT_HASHED,		/* The layout visible */
+	NFS_LAYOUT_DRAIN,
+};
+
+enum layoutdriver_policy_flags {
+	/* Should the pNFS client commit and return the layout upon truncate to
+	 * a smaller size */
+	PNFS_LAYOUTRET_ON_SETATTR	= 1 << 0,
+	PNFS_LAYOUTRET_ON_ERROR		= 1 << 1,
+	PNFS_READ_WHOLE_PAGE		= 1 << 2,
+	PNFS_LAYOUTGET_ON_OPEN		= 1 << 3,
+};
+
+struct nfs4_deviceid_node;
+
+/* Per-layout driver specific registration structure */
+struct pnfs_layoutdriver_type {
+	struct list_head pnfs_tblid;
+	const u32 id;
+	const char *name;
+	struct module *owner;
+	unsigned flags;
+	unsigned max_deviceinfo_size;
+	unsigned max_layoutget_response;
+
+	int (*set_layoutdriver) (struct nfs_server *, const struct nfs_fh *);
+	int (*clear_layoutdriver) (struct nfs_server *);
+
+	struct pnfs_layout_hdr * (*alloc_layout_hdr) (struct inode *inode, gfp_t gfp_flags);
+	void (*free_layout_hdr) (struct pnfs_layout_hdr *);
+
+	struct pnfs_layout_segment * (*alloc_lseg) (struct pnfs_layout_hdr *layoutid, struct nfs4_layoutget_res *lgr, gfp_t gfp_flags);
+	void (*free_lseg) (struct pnfs_layout_segment *lseg);
+	void (*add_lseg) (struct pnfs_layout_hdr *layoutid,
+			struct pnfs_layout_segment *lseg,
+			struct list_head *free_me);
+
+	void (*return_range) (struct pnfs_layout_hdr *lo,
+			      struct pnfs_layout_range *range);
+
+	/* test for nfs page cache coalescing */
+	const struct nfs_pageio_ops *pg_read_ops;
+	const struct nfs_pageio_ops *pg_write_ops;
+
+	struct pnfs_ds_commit_info *(*get_ds_info) (struct inode *inode);
+
+	int (*sync)(struct inode *inode, bool datasync);
+
+	/*
+	 * Return PNFS_ATTEMPTED to indicate the layout code has attempted
+	 * I/O, else return PNFS_NOT_ATTEMPTED to fall back to normal NFS
+	 */
+	enum pnfs_try_status (*read_pagelist)(struct nfs_pgio_header *);
+	enum pnfs_try_status (*write_pagelist)(struct nfs_pgio_header *, int);
+
+	void (*free_deviceid_node) (struct nfs4_deviceid_node *);
+	struct nfs4_deviceid_node * (*alloc_deviceid_node)
+			(struct nfs_server *server, struct pnfs_device *pdev,
+			gfp_t gfp_flags);
+
+	int (*prepare_layoutreturn) (struct nfs4_layoutreturn_args *);
+
+	void (*cleanup_layoutcommit) (struct nfs4_layoutcommit_data *data);
+	int (*prepare_layoutcommit) (struct nfs4_layoutcommit_args *args);
+	int (*prepare_layoutstats) (struct nfs42_layoutstat_args *args);
+};
+
+struct pnfs_commit_ops {
+	void (*setup_ds_info)(struct pnfs_ds_commit_info *,
+			      struct pnfs_layout_segment *);
+	void (*release_ds_info)(struct pnfs_ds_commit_info *,
+				struct inode *inode);
+	int (*commit_pagelist)(struct inode *inode,
+			       struct list_head *mds_pages,
+			       int how,
+			       struct nfs_commit_info *cinfo);
+	void (*mark_request_commit) (struct nfs_page *req,
+				     struct pnfs_layout_segment *lseg,
+				     struct nfs_commit_info *cinfo,
+				     u32 ds_commit_idx);
+	void (*clear_request_commit) (struct nfs_page *req,
+				      struct nfs_commit_info *cinfo);
+	int (*scan_commit_lists) (struct nfs_commit_info *cinfo,
+				  int max);
+	void (*recover_commit_reqs) (struct list_head *list,
+				     struct nfs_commit_info *cinfo);
+	struct nfs_page * (*search_commit_reqs)(struct nfs_commit_info *cinfo,
+						struct page *page);
+};
+
+struct pnfs_layout_hdr {
+	refcount_t		plh_refcount;
+	atomic_t		plh_outstanding; /* number of RPCs out */
+	struct list_head	plh_layouts;   /* other client layouts */
+	struct list_head	plh_bulk_destroy;
+	struct list_head	plh_segs;      /* layout segments list */
+	struct list_head	plh_return_segs; /* invalid layout segments */
+	unsigned long		plh_block_lgets; /* block LAYOUTGET if >0 */
+	unsigned long		plh_retry_timestamp;
+	unsigned long		plh_flags;
+	nfs4_stateid		plh_stateid;
+	u32			plh_barrier; /* ignore lower seqids */
+	u32			plh_return_seq;
+	enum pnfs_iomode	plh_return_iomode;
+	loff_t			plh_lwb; /* last write byte for layoutcommit */
+	const struct cred	*plh_lc_cred; /* layoutcommit cred */
+	struct inode		*plh_inode;
+	struct rcu_head		plh_rcu;
+};
+
+struct pnfs_device {
+	struct nfs4_deviceid dev_id;
+	unsigned int  layout_type;
+	unsigned int  mincount;
+	unsigned int  maxcount;	/* gdia_maxcount */
+	struct page **pages;
+	unsigned int  pgbase;
+	unsigned int  pglen;	/* reply buffer length */
+	unsigned char nocache : 1;/* May not be cached */
+};
+
+#define NFS4_PNFS_GETDEVLIST_MAXNUM 16
+
+struct pnfs_devicelist {
+	unsigned int		eof;
+	unsigned int		num_devs;
+	struct nfs4_deviceid	dev_id[NFS4_PNFS_GETDEVLIST_MAXNUM];
+};
+
+extern int pnfs_register_layoutdriver(struct pnfs_layoutdriver_type *);
+extern void pnfs_unregister_layoutdriver(struct pnfs_layoutdriver_type *);
+extern const struct pnfs_layoutdriver_type *pnfs_find_layoutdriver(u32 id);
+extern void pnfs_put_layoutdriver(const struct pnfs_layoutdriver_type *ld);
+
+/* nfs4proc.c */
+extern size_t max_response_pages(struct nfs_server *server);
+extern int nfs4_proc_getdeviceinfo(struct nfs_server *server,
+				   struct pnfs_device *dev,
+				   const struct cred *cred);
+extern struct pnfs_layout_segment* nfs4_proc_layoutget(struct nfs4_layoutget *lgp, long *timeout);
+extern int nfs4_proc_layoutreturn(struct nfs4_layoutreturn *lrp, bool sync);
+
+/* pnfs.c */
+void pnfs_get_layout_hdr(struct pnfs_layout_hdr *lo);
+void pnfs_put_lseg(struct pnfs_layout_segment *lseg);
+
+void set_pnfs_layoutdriver(struct nfs_server *, const struct nfs_fh *, struct nfs_fsinfo *);
+void unset_pnfs_layoutdriver(struct nfs_server *);
+void pnfs_generic_pg_check_layout(struct nfs_pageio_descriptor *pgio);
+void pnfs_generic_pg_check_range(struct nfs_pageio_descriptor *pgio, struct nfs_page *req);
+void pnfs_generic_pg_init_read(struct nfs_pageio_descriptor *, struct nfs_page *);
+int pnfs_generic_pg_readpages(struct nfs_pageio_descriptor *desc);
+void pnfs_generic_pg_init_write(struct nfs_pageio_descriptor *pgio,
+			        struct nfs_page *req, u64 wb_size);
+void pnfs_generic_pg_cleanup(struct nfs_pageio_descriptor *);
+int pnfs_generic_pg_writepages(struct nfs_pageio_descriptor *desc);
+size_t pnfs_generic_pg_test(struct nfs_pageio_descriptor *pgio,
+			    struct nfs_page *prev, struct nfs_page *req);
+void pnfs_set_lo_fail(struct pnfs_layout_segment *lseg);
+struct pnfs_layout_segment *pnfs_layout_process(struct nfs4_layoutget *lgp);
+void pnfs_layoutget_free(struct nfs4_layoutget *lgp);
+void pnfs_free_lseg_list(struct list_head *tmp_list);
+void pnfs_destroy_layout(struct nfs_inode *);
+void pnfs_destroy_layout_final(struct nfs_inode *);
+void pnfs_destroy_all_layouts(struct nfs_client *);
+int pnfs_destroy_layouts_byfsid(struct nfs_client *clp,
+		struct nfs_fsid *fsid,
+		bool is_recall);
+int pnfs_destroy_layouts_byclid(struct nfs_client *clp,
+		bool is_recall);
+bool nfs4_layout_refresh_old_stateid(nfs4_stateid *dst,
+		struct pnfs_layout_range *dst_range,
+		struct inode *inode);
+void pnfs_put_layout_hdr(struct pnfs_layout_hdr *lo);
+void pnfs_set_layout_stateid(struct pnfs_layout_hdr *lo,
+			     const nfs4_stateid *new,
+			     const struct cred *cred,
+			     bool update_barrier);
+int pnfs_mark_matching_lsegs_invalid(struct pnfs_layout_hdr *lo,
+				struct list_head *tmp_list,
+				const struct pnfs_layout_range *recall_range,
+				u32 seq);
+int pnfs_mark_matching_lsegs_return(struct pnfs_layout_hdr *lo,
+				struct list_head *tmp_list,
+				const struct pnfs_layout_range *recall_range,
+				u32 seq);
+int pnfs_mark_layout_stateid_invalid(struct pnfs_layout_hdr *lo,
+		struct list_head *lseg_list);
+bool pnfs_roc(struct inode *ino,
+		struct nfs4_layoutreturn_args *args,
+		struct nfs4_layoutreturn_res *res,
+		const struct cred *cred);
+int pnfs_roc_done(struct rpc_task *task, struct nfs4_layoutreturn_args **argpp,
+		  struct nfs4_layoutreturn_res **respp, int *ret);
+void pnfs_roc_release(struct nfs4_layoutreturn_args *args,
+		struct nfs4_layoutreturn_res *res,
+		int ret);
+bool pnfs_wait_on_layoutreturn(struct inode *ino, struct rpc_task *task);
+void pnfs_set_layoutcommit(struct inode *, struct pnfs_layout_segment *, loff_t);
+void pnfs_cleanup_layoutcommit(struct nfs4_layoutcommit_data *data);
+int pnfs_layoutcommit_inode(struct inode *inode, bool sync);
+int pnfs_generic_sync(struct inode *inode, bool datasync);
+int pnfs_nfs_generic_sync(struct inode *inode, bool datasync);
+int _pnfs_return_layout(struct inode *);
+int pnfs_commit_and_return_layout(struct inode *);
+void pnfs_ld_write_done(struct nfs_pgio_header *);
+void pnfs_ld_read_done(struct nfs_pgio_header *);
+void pnfs_read_resend_pnfs(struct nfs_pgio_header *, unsigned int mirror_idx);
+struct pnfs_layout_segment *pnfs_update_layout(struct inode *ino,
+					       struct nfs_open_context *ctx,
+					       loff_t pos,
+					       u64 count,
+					       enum pnfs_iomode iomode,
+					       bool strict_iomode,
+					       gfp_t gfp_flags);
+void pnfs_layoutreturn_free_lsegs(struct pnfs_layout_hdr *lo,
+		const nfs4_stateid *arg_stateid,
+		const struct pnfs_layout_range *range,
+		const nfs4_stateid *stateid);
+
+void pnfs_generic_layout_insert_lseg(struct pnfs_layout_hdr *lo,
+		   struct pnfs_layout_segment *lseg,
+		   bool (*is_after)(const struct pnfs_layout_range *lseg_range,
+			   const struct pnfs_layout_range *old),
+		   bool (*do_merge)(struct pnfs_layout_segment *lseg,
+			   struct pnfs_layout_segment *old),
+		   struct list_head *free_me);
+
+void nfs4_deviceid_mark_client_invalid(struct nfs_client *clp);
+int pnfs_read_done_resend_to_mds(struct nfs_pgio_header *);
+int pnfs_write_done_resend_to_mds(struct nfs_pgio_header *);
+struct nfs4_threshold *pnfs_mdsthreshold_alloc(void);
+void pnfs_error_mark_layout_for_return(struct inode *inode,
+				       struct pnfs_layout_segment *lseg);
+void pnfs_layout_return_unused_byclid(struct nfs_client *clp,
+				      enum pnfs_iomode iomode);
+
+/* nfs4_deviceid_flags */
+enum {
+	NFS_DEVICEID_INVALID = 0,       /* set when MDS clientid recalled */
+	NFS_DEVICEID_UNAVAILABLE,	/* device temporarily unavailable */
+	NFS_DEVICEID_NOCACHE,		/* device may not be cached */
+};
+
+/* pnfs_dev.c */
+struct nfs4_deviceid_node {
+	struct hlist_node		node;
+	struct hlist_node		tmpnode;
+	const struct pnfs_layoutdriver_type *ld;
+	const struct nfs_client		*nfs_client;
+	unsigned long 			flags;
+	unsigned long			timestamp_unavailable;
+	struct nfs4_deviceid		deviceid;
+	struct rcu_head			rcu;
+	atomic_t			ref;
+};
+
+struct nfs4_deviceid_node *
+nfs4_find_get_deviceid(struct nfs_server *server,
+		const struct nfs4_deviceid *id, const struct cred *cred,
+		gfp_t gfp_mask);
+void nfs4_delete_deviceid(const struct pnfs_layoutdriver_type *, const struct nfs_client *, const struct nfs4_deviceid *);
+void nfs4_init_deviceid_node(struct nfs4_deviceid_node *, struct nfs_server *,
+			     const struct nfs4_deviceid *);
+bool nfs4_put_deviceid_node(struct nfs4_deviceid_node *);
+void nfs4_mark_deviceid_available(struct nfs4_deviceid_node *node);
+void nfs4_mark_deviceid_unavailable(struct nfs4_deviceid_node *node);
+bool nfs4_test_deviceid_unavailable(struct nfs4_deviceid_node *node);
+void nfs4_deviceid_purge_client(const struct nfs_client *);
+
+/* pnfs_nfs.c */
+struct pnfs_commit_array *pnfs_alloc_commit_array(size_t n, gfp_t gfp_flags);
+void pnfs_free_commit_array(struct pnfs_commit_array *p);
+struct pnfs_commit_array *pnfs_add_commit_array(struct pnfs_ds_commit_info *,
+						struct pnfs_commit_array *,
+						struct pnfs_layout_segment *);
+
+void pnfs_generic_ds_cinfo_release_lseg(struct pnfs_ds_commit_info *fl_cinfo,
+		struct pnfs_layout_segment *lseg);
+void pnfs_generic_ds_cinfo_destroy(struct pnfs_ds_commit_info *fl_cinfo);
+
+void pnfs_generic_clear_request_commit(struct nfs_page *req,
+				       struct nfs_commit_info *cinfo);
+void pnfs_generic_commit_release(void *calldata);
+void pnfs_generic_prepare_to_resend_writes(struct nfs_commit_data *data);
+void pnfs_generic_rw_release(void *data);
+void pnfs_generic_recover_commit_reqs(struct list_head *dst,
+				      struct nfs_commit_info *cinfo);
+struct nfs_page *pnfs_generic_search_commit_reqs(struct nfs_commit_info *cinfo,
+						 struct page *page);
+int pnfs_generic_commit_pagelist(struct inode *inode,
+				 struct list_head *mds_pages,
+				 int how,
+				 struct nfs_commit_info *cinfo,
+				 int (*initiate_commit)(struct nfs_commit_data *data,
+							int how));
+int pnfs_generic_scan_commit_lists(struct nfs_commit_info *cinfo, int max);
+void pnfs_generic_write_commit_done(struct rpc_task *task, void *data);
+void nfs4_pnfs_ds_put(struct nfs4_pnfs_ds *ds);
+struct nfs4_pnfs_ds *nfs4_pnfs_ds_add(struct list_head *dsaddrs,
+				      gfp_t gfp_flags);
+void nfs4_pnfs_v3_ds_connect_unload(void);
+int nfs4_pnfs_ds_connect(struct nfs_server *mds_srv, struct nfs4_pnfs_ds *ds,
+			  struct nfs4_deviceid_node *devid, unsigned int timeo,
+			  unsigned int retrans, u32 version, u32 minor_version);
+struct nfs4_pnfs_ds_addr *nfs4_decode_mp_ds_addr(struct net *net,
+						 struct xdr_stream *xdr,
+						 gfp_t gfp_flags);
+void pnfs_layout_mark_request_commit(struct nfs_page *req,
+				     struct pnfs_layout_segment *lseg,
+				     struct nfs_commit_info *cinfo,
+				     u32 ds_commit_idx);
+void pnfs_lgopen_prepare(struct nfs4_opendata *data,
+			 struct nfs_open_context *ctx);
+void pnfs_parse_lgopen(struct inode *ino, struct nfs4_layoutget *lgp,
+		       struct nfs_open_context *ctx);
+void nfs4_lgopen_release(struct nfs4_layoutget *lgp);
+
+static inline bool nfs_have_layout(struct inode *inode)
+{
+	return NFS_I(inode)->layout != NULL;
+}
+
+static inline bool pnfs_layout_is_valid(const struct pnfs_layout_hdr *lo)
+{
+	return test_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags) == 0;
+}
+
+static inline struct nfs4_deviceid_node *
+nfs4_get_deviceid(struct nfs4_deviceid_node *d)
+{
+	atomic_inc(&d->ref);
+	return d;
+}
+
+static inline struct pnfs_layout_segment *
+pnfs_get_lseg(struct pnfs_layout_segment *lseg)
+{
+	if (lseg) {
+		refcount_inc(&lseg->pls_refcount);
+		smp_mb__after_atomic();
+	}
+	return lseg;
+}
+
+static inline bool
+pnfs_is_valid_lseg(struct pnfs_layout_segment *lseg)
+{
+	return test_bit(NFS_LSEG_VALID, &lseg->pls_flags) != 0;
+}
+
+/* Return true if a layout driver is being used for this mountpoint */
+static inline int pnfs_enabled_sb(struct nfs_server *nfss)
+{
+	return nfss->pnfs_curr_ld != NULL;
+}
+
+static inline int
+pnfs_commit_list(struct inode *inode, struct list_head *mds_pages, int how,
+		 struct nfs_commit_info *cinfo)
+{
+	struct pnfs_ds_commit_info *fl_cinfo = cinfo->ds;
+
+	if (fl_cinfo == NULL || fl_cinfo->ncommitting == 0)
+		return PNFS_NOT_ATTEMPTED;
+	return fl_cinfo->ops->commit_pagelist(inode, mds_pages, how, cinfo);
+}
+
+static inline struct pnfs_ds_commit_info *
+pnfs_get_ds_info(struct inode *inode)
+{
+	struct pnfs_layoutdriver_type *ld = NFS_SERVER(inode)->pnfs_curr_ld;
+
+	if (ld == NULL || ld->get_ds_info == NULL)
+		return NULL;
+	return ld->get_ds_info(inode);
+}
+
+static inline void
+pnfs_init_ds_commit_info_ops(struct pnfs_ds_commit_info *fl_cinfo, struct inode *inode)
+{
+	struct pnfs_ds_commit_info *inode_cinfo = pnfs_get_ds_info(inode);
+	if (inode_cinfo != NULL)
+		fl_cinfo->ops = inode_cinfo->ops;
+}
+
+static inline void
+pnfs_init_ds_commit_info(struct pnfs_ds_commit_info *fl_cinfo)
+{
+	INIT_LIST_HEAD(&fl_cinfo->commits);
+	fl_cinfo->ops = NULL;
+}
+
+static inline void
+pnfs_release_ds_info(struct pnfs_ds_commit_info *fl_cinfo, struct inode *inode)
+{
+	if (fl_cinfo->ops != NULL && fl_cinfo->ops->release_ds_info != NULL)
+		fl_cinfo->ops->release_ds_info(fl_cinfo, inode);
+}
+
+static inline void
+pnfs_generic_mark_devid_invalid(struct nfs4_deviceid_node *node)
+{
+	set_bit(NFS_DEVICEID_INVALID, &node->flags);
+}
+
+static inline bool
+pnfs_mark_request_commit(struct nfs_page *req, struct pnfs_layout_segment *lseg,
+			 struct nfs_commit_info *cinfo, u32 ds_commit_idx)
+{
+	struct pnfs_ds_commit_info *fl_cinfo = cinfo->ds;
+
+	if (!lseg || !fl_cinfo->ops || !fl_cinfo->ops->mark_request_commit)
+		return false;
+	fl_cinfo->ops->mark_request_commit(req, lseg, cinfo, ds_commit_idx);
+	return true;
+}
+
+static inline bool
+pnfs_clear_request_commit(struct nfs_page *req, struct nfs_commit_info *cinfo)
+{
+	struct pnfs_ds_commit_info *fl_cinfo = cinfo->ds;
+
+	if (!fl_cinfo || !fl_cinfo->ops || !fl_cinfo->ops->clear_request_commit)
+		return false;
+	fl_cinfo->ops->clear_request_commit(req, cinfo);
+	return true;
+}
+
+static inline int
+pnfs_scan_commit_lists(struct inode *inode, struct nfs_commit_info *cinfo,
+		       int max)
+{
+	struct pnfs_ds_commit_info *fl_cinfo = cinfo->ds;
+
+	if (!fl_cinfo || fl_cinfo->nwritten == 0)
+		return 0;
+	return fl_cinfo->ops->scan_commit_lists(cinfo, max);
+}
+
+static inline void
+pnfs_recover_commit_reqs(struct list_head *head, struct nfs_commit_info *cinfo)
+{
+	struct pnfs_ds_commit_info *fl_cinfo = cinfo->ds;
+
+	if (fl_cinfo && fl_cinfo->nwritten != 0)
+		fl_cinfo->ops->recover_commit_reqs(head, cinfo);
+}
+
+static inline struct nfs_page *
+pnfs_search_commit_reqs(struct inode *inode, struct nfs_commit_info *cinfo,
+			struct page *page)
+{
+	struct pnfs_ds_commit_info *fl_cinfo = cinfo->ds;
+
+	if (!fl_cinfo->ops || !fl_cinfo->ops->search_commit_reqs)
+		return NULL;
+	return fl_cinfo->ops->search_commit_reqs(cinfo, page);
+}
+
+/* Should the pNFS client commit and return the layout upon a setattr */
+static inline bool
+pnfs_ld_layoutret_on_setattr(struct inode *inode)
+{
+	if (!pnfs_enabled_sb(NFS_SERVER(inode)))
+		return false;
+	return NFS_SERVER(inode)->pnfs_curr_ld->flags &
+		PNFS_LAYOUTRET_ON_SETATTR;
+}
+
+static inline bool
+pnfs_ld_read_whole_page(struct inode *inode)
+{
+	if (!pnfs_enabled_sb(NFS_SERVER(inode)))
+		return false;
+	return NFS_SERVER(inode)->pnfs_curr_ld->flags & PNFS_READ_WHOLE_PAGE;
+}
+
+static inline int
+pnfs_sync_inode(struct inode *inode, bool datasync)
+{
+	if (!pnfs_enabled_sb(NFS_SERVER(inode)))
+		return 0;
+	return NFS_SERVER(inode)->pnfs_curr_ld->sync(inode, datasync);
+}
+
+static inline bool
+pnfs_layoutcommit_outstanding(struct inode *inode)
+{
+	struct nfs_inode *nfsi = NFS_I(inode);
+
+	return test_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags) != 0 ||
+		test_bit(NFS_INO_LAYOUTCOMMITTING, &nfsi->flags) != 0;
+}
+
+static inline int pnfs_return_layout(struct inode *ino)
+{
+	struct nfs_inode *nfsi = NFS_I(ino);
+	struct nfs_server *nfss = NFS_SERVER(ino);
+
+	if (pnfs_enabled_sb(nfss) && nfsi->layout) {
+		set_bit(NFS_LAYOUT_RETURN_REQUESTED, &nfsi->layout->plh_flags);
+		return _pnfs_return_layout(ino);
+	}
+
+	return 0;
+}
+
+static inline bool
+pnfs_use_threshold(struct nfs4_threshold **dst, struct nfs4_threshold *src,
+		   struct nfs_server *nfss)
+{
+	return (dst && src && src->bm != 0 && nfss->pnfs_curr_ld &&
+					nfss->pnfs_curr_ld->id == src->l_type);
+}
+
+static inline u64
+pnfs_calc_offset_end(u64 offset, u64 len)
+{
+	if (len == NFS4_MAX_UINT64 || len >= NFS4_MAX_UINT64 - offset)
+		return NFS4_MAX_UINT64;
+	return offset + len - 1;
+}
+
+static inline u64
+pnfs_calc_offset_length(u64 offset, u64 end)
+{
+	if (end == NFS4_MAX_UINT64 || end <= offset)
+		return NFS4_MAX_UINT64;
+	return 1 + end - offset;
+}
+
+static inline void
+pnfs_copy_range(struct pnfs_layout_range *dst,
+		const struct pnfs_layout_range *src)
+{
+	memcpy(dst, src, sizeof(*dst));
+}
+
+static inline u64
+pnfs_end_offset(u64 start, u64 len)
+{
+	if (NFS4_MAX_UINT64 - start <= len)
+		return NFS4_MAX_UINT64;
+	return start + len;
+}
+
+/*
+ * Are 2 ranges intersecting?
+ *   start1                             end1
+ *   [----------------------------------)
+ *                                start2           end2
+ *                                [----------------)
+ */
+static inline bool
+pnfs_is_range_intersecting(u64 start1, u64 end1, u64 start2, u64 end2)
+{
+	return (end1 == NFS4_MAX_UINT64 || start2 < end1) &&
+		(end2 == NFS4_MAX_UINT64 || start1 < end2);
+}
+
+static inline bool
+pnfs_lseg_range_intersecting(const struct pnfs_layout_range *l1,
+		const struct pnfs_layout_range *l2)
+{
+	u64 end1 = pnfs_end_offset(l1->offset, l1->length);
+	u64 end2 = pnfs_end_offset(l2->offset, l2->length);
+
+	return pnfs_is_range_intersecting(l1->offset, end1, l2->offset, end2);
+}
+
+static inline bool
+pnfs_lseg_request_intersecting(struct pnfs_layout_segment *lseg, struct nfs_page *req)
+{
+	u64 seg_last = pnfs_end_offset(lseg->pls_range.offset, lseg->pls_range.length);
+	u64 req_last = req_offset(req) + req->wb_bytes;
+
+	return pnfs_is_range_intersecting(lseg->pls_range.offset, seg_last,
+				req_offset(req), req_last);
+}
+
+extern unsigned int layoutstats_timer;
+
+#ifdef NFS_DEBUG
+void nfs4_print_deviceid(const struct nfs4_deviceid *dev_id);
+#else
+static inline void nfs4_print_deviceid(const struct nfs4_deviceid *dev_id)
+{
+}
+
+#endif /* NFS_DEBUG */
+#else  /* CONFIG_NFS_V4_1 */
+
+static inline bool nfs_have_layout(struct inode *inode)
+{
+	return false;
+}
+
+static inline void pnfs_destroy_all_layouts(struct nfs_client *clp)
+{
+}
+
+static inline void pnfs_destroy_layout(struct nfs_inode *nfsi)
+{
+}
+
+static inline void pnfs_destroy_layout_final(struct nfs_inode *nfsi)
+{
+}
+
+static inline struct pnfs_layout_segment *
+pnfs_get_lseg(struct pnfs_layout_segment *lseg)
+{
+	return NULL;
+}
+
+static inline void pnfs_put_lseg(struct pnfs_layout_segment *lseg)
+{
+}
+
+static inline int pnfs_return_layout(struct inode *ino)
+{
+	return 0;
+}
+
+static inline int pnfs_commit_and_return_layout(struct inode *inode)
+{
+	return 0;
+}
+
+static inline bool
+pnfs_ld_layoutret_on_setattr(struct inode *inode)
+{
+	return false;
+}
+
+static inline bool
+pnfs_ld_read_whole_page(struct inode *inode)
+{
+	return false;
+}
+
+static inline int
+pnfs_sync_inode(struct inode *inode, bool datasync)
+{
+	return 0;
+}
+
+static inline bool
+pnfs_layoutcommit_outstanding(struct inode *inode)
+{
+	return false;
+}
+
+
+static inline bool
+pnfs_roc(struct inode *ino,
+		struct nfs4_layoutreturn_args *args,
+		struct nfs4_layoutreturn_res *res,
+		const struct cred *cred)
+{
+	return false;
+}
+
+static inline int
+pnfs_roc_done(struct rpc_task *task,
+		struct nfs4_layoutreturn_args **argpp,
+		struct nfs4_layoutreturn_res **respp,
+		int *ret)
+{
+	return 0;
+}
+
+static inline void
+pnfs_roc_release(struct nfs4_layoutreturn_args *args,
+		struct nfs4_layoutreturn_res *res,
+		int ret)
+{
+}
+
+static inline bool
+pnfs_wait_on_layoutreturn(struct inode *ino, struct rpc_task *task)
+{
+	return false;
+}
+
+static inline void set_pnfs_layoutdriver(struct nfs_server *s,
+					 const struct nfs_fh *mntfh,
+					 struct nfs_fsinfo *fsinfo)
+{
+}
+
+static inline void unset_pnfs_layoutdriver(struct nfs_server *s)
+{
+}
+
+static inline int
+pnfs_commit_list(struct inode *inode, struct list_head *mds_pages, int how,
+		 struct nfs_commit_info *cinfo)
+{
+	return PNFS_NOT_ATTEMPTED;
+}
+
+static inline struct pnfs_ds_commit_info *
+pnfs_get_ds_info(struct inode *inode)
+{
+	return NULL;
+}
+
+static inline void
+pnfs_init_ds_commit_info_ops(struct pnfs_ds_commit_info *fl_cinfo, struct inode *inode)
+{
+}
+
+static inline void
+pnfs_init_ds_commit_info(struct pnfs_ds_commit_info *fl_cinfo)
+{
+}
+
+static inline void
+pnfs_release_ds_info(struct pnfs_ds_commit_info *fl_cinfo, struct inode *inode)
+{
+}
+
+static inline bool
+pnfs_mark_request_commit(struct nfs_page *req, struct pnfs_layout_segment *lseg,
+			 struct nfs_commit_info *cinfo, u32 ds_commit_idx)
+{
+	return false;
+}
+
+static inline bool
+pnfs_clear_request_commit(struct nfs_page *req, struct nfs_commit_info *cinfo)
+{
+	return false;
+}
+
+static inline int
+pnfs_scan_commit_lists(struct inode *inode, struct nfs_commit_info *cinfo,
+		       int max)
+{
+	return 0;
+}
+
+static inline void
+pnfs_recover_commit_reqs(struct list_head *head, struct nfs_commit_info *cinfo)
+{
+}
+
+static inline struct nfs_page *
+pnfs_search_commit_reqs(struct inode *inode, struct nfs_commit_info *cinfo,
+			struct page *page)
+{
+	return NULL;
+}
+
+static inline int pnfs_layoutcommit_inode(struct inode *inode, bool sync)
+{
+	return 0;
+}
+
+static inline bool
+pnfs_use_threshold(struct nfs4_threshold **dst, struct nfs4_threshold *src,
+		   struct nfs_server *nfss)
+{
+	return false;
+}
+
+static inline struct nfs4_threshold *pnfs_mdsthreshold_alloc(void)
+{
+	return NULL;
+}
+
+static inline void nfs4_pnfs_v3_ds_connect_unload(void)
+{
+}
+
+static inline bool nfs4_layout_refresh_old_stateid(nfs4_stateid *dst,
+		struct pnfs_layout_range *dst_range,
+		struct inode *inode)
+{
+	return false;
+}
+
+static inline void pnfs_lgopen_prepare(struct nfs4_opendata *data,
+		struct nfs_open_context *ctx)
+{
+}
+
+static inline void pnfs_parse_lgopen(struct inode *ino,
+		struct nfs4_layoutget *lgp,
+		struct nfs_open_context *ctx)
+{
+}
+
+static inline void nfs4_lgopen_release(struct nfs4_layoutget *lgp)
+{
+}
+
+static inline bool pnfs_layout_is_valid(const struct pnfs_layout_hdr *lo)
+{
+	return false;
+}
+
+#endif /* CONFIG_NFS_V4_1 */
+
+#if IS_ENABLED(CONFIG_NFS_V4_2)
+int pnfs_report_layoutstat(struct inode *inode, gfp_t gfp_flags);
+#else
+static inline int
+pnfs_report_layoutstat(struct inode *inode, gfp_t gfp_flags)
+{
+	return 0;
+}
+#endif
+
+#endif /* FS_NFS_PNFS_H */
diff --git a/fs/nfs/pnfs_dev.c b/fs/nfs/pnfs_dev.c
new file mode 100644
index 000000000..d4829f3f2
--- /dev/null
+++ b/fs/nfs/pnfs_dev.c
@@ -0,0 +1,377 @@
+/*
+ *  Device operations for the pnfs client.
+ *
+ *  Copyright (c) 2002
+ *  The Regents of the University of Michigan
+ *  All Rights Reserved
+ *
+ *  Dean Hildebrand <dhildebz@umich.edu>
+ *  Garth Goodson   <Garth.Goodson@netapp.com>
+ *
+ *  Permission is granted to use, copy, create derivative works, and
+ *  redistribute this software and such derivative works for any purpose,
+ *  so long as the name of the University of Michigan is not used in
+ *  any advertising or publicity pertaining to the use or distribution
+ *  of this software without specific, written prior authorization. If
+ *  the above copyright notice or any other identification of the
+ *  University of Michigan is included in any copy of any portion of
+ *  this software, then the disclaimer below must also be included.
+ *
+ *  This software is provided as is, without representation or warranty
+ *  of any kind either express or implied, including without limitation
+ *  the implied warranties of merchantability, fitness for a particular
+ *  purpose, or noninfringement.  The Regents of the University of
+ *  Michigan shall not be liable for any damages, including special,
+ *  indirect, incidental, or consequential damages, with respect to any
+ *  claim arising out of or in connection with the use of the software,
+ *  even if it has been or is hereafter advised of the possibility of
+ *  such damages.
+ */
+
+#include <linux/export.h>
+#include <linux/nfs_fs.h>
+#include "nfs4session.h"
+#include "internal.h"
+#include "pnfs.h"
+
+#define NFSDBG_FACILITY		NFSDBG_PNFS
+
+/*
+ * Device ID RCU cache. A device ID is unique per server and layout type.
+ */
+#define NFS4_DEVICE_ID_HASH_BITS	5
+#define NFS4_DEVICE_ID_HASH_SIZE	(1 << NFS4_DEVICE_ID_HASH_BITS)
+#define NFS4_DEVICE_ID_HASH_MASK	(NFS4_DEVICE_ID_HASH_SIZE - 1)
+
+
+static struct hlist_head nfs4_deviceid_cache[NFS4_DEVICE_ID_HASH_SIZE];
+static DEFINE_SPINLOCK(nfs4_deviceid_lock);
+
+#ifdef NFS_DEBUG
+void
+nfs4_print_deviceid(const struct nfs4_deviceid *id)
+{
+	u32 *p = (u32 *)id;
+
+	dprintk("%s: device id= [%x%x%x%x]\n", __func__,
+		p[0], p[1], p[2], p[3]);
+}
+EXPORT_SYMBOL_GPL(nfs4_print_deviceid);
+#endif
+
+static inline u32
+nfs4_deviceid_hash(const struct nfs4_deviceid *id)
+{
+	unsigned char *cptr = (unsigned char *)id->data;
+	unsigned int nbytes = NFS4_DEVICEID4_SIZE;
+	u32 x = 0;
+
+	while (nbytes--) {
+		x *= 37;
+		x += *cptr++;
+	}
+	return x & NFS4_DEVICE_ID_HASH_MASK;
+}
+
+static struct nfs4_deviceid_node *
+_lookup_deviceid(const struct pnfs_layoutdriver_type *ld,
+		 const struct nfs_client *clp, const struct nfs4_deviceid *id,
+		 long hash)
+{
+	struct nfs4_deviceid_node *d;
+
+	hlist_for_each_entry_rcu(d, &nfs4_deviceid_cache[hash], node)
+		if (d->ld == ld && d->nfs_client == clp &&
+		    !memcmp(&d->deviceid, id, sizeof(*id))) {
+			if (atomic_read(&d->ref))
+				return d;
+			else
+				continue;
+		}
+	return NULL;
+}
+
+static struct nfs4_deviceid_node *
+nfs4_get_device_info(struct nfs_server *server,
+		const struct nfs4_deviceid *dev_id,
+		const struct cred *cred, gfp_t gfp_flags)
+{
+	struct nfs4_deviceid_node *d = NULL;
+	struct pnfs_device *pdev = NULL;
+	struct page **pages = NULL;
+	u32 max_resp_sz;
+	int max_pages;
+	int rc, i;
+
+	/*
+	 * Use the session max response size as the basis for setting
+	 * GETDEVICEINFO's maxcount
+	 */
+	max_resp_sz = server->nfs_client->cl_session->fc_attrs.max_resp_sz;
+	if (server->pnfs_curr_ld->max_deviceinfo_size &&
+	    server->pnfs_curr_ld->max_deviceinfo_size < max_resp_sz)
+		max_resp_sz = server->pnfs_curr_ld->max_deviceinfo_size;
+	max_pages = nfs_page_array_len(0, max_resp_sz);
+	dprintk("%s: server %p max_resp_sz %u max_pages %d\n",
+		__func__, server, max_resp_sz, max_pages);
+
+	pdev = kzalloc(sizeof(*pdev), gfp_flags);
+	if (!pdev)
+		return NULL;
+
+	pages = kcalloc(max_pages, sizeof(struct page *), gfp_flags);
+	if (!pages)
+		goto out_free_pdev;
+
+	for (i = 0; i < max_pages; i++) {
+		pages[i] = alloc_page(gfp_flags);
+		if (!pages[i])
+			goto out_free_pages;
+	}
+
+	memcpy(&pdev->dev_id, dev_id, sizeof(*dev_id));
+	pdev->layout_type = server->pnfs_curr_ld->id;
+	pdev->pages = pages;
+	pdev->pgbase = 0;
+	pdev->pglen = max_resp_sz;
+	pdev->mincount = 0;
+	pdev->maxcount = max_resp_sz - nfs41_maxgetdevinfo_overhead;
+
+	rc = nfs4_proc_getdeviceinfo(server, pdev, cred);
+	dprintk("%s getdevice info returns %d\n", __func__, rc);
+	if (rc)
+		goto out_free_pages;
+
+	/*
+	 * Found new device, need to decode it and then add it to the
+	 * list of known devices for this mountpoint.
+	 */
+	d = server->pnfs_curr_ld->alloc_deviceid_node(server, pdev,
+			gfp_flags);
+	if (d && pdev->nocache)
+		set_bit(NFS_DEVICEID_NOCACHE, &d->flags);
+
+out_free_pages:
+	while (--i >= 0)
+		__free_page(pages[i]);
+	kfree(pages);
+out_free_pdev:
+	kfree(pdev);
+	dprintk("<-- %s d %p\n", __func__, d);
+	return d;
+}
+
+/*
+ * Lookup a deviceid in cache and get a reference count on it if found
+ *
+ * @clp nfs_client associated with deviceid
+ * @id deviceid to look up
+ */
+static struct nfs4_deviceid_node *
+__nfs4_find_get_deviceid(struct nfs_server *server,
+		const struct nfs4_deviceid *id, long hash)
+{
+	struct nfs4_deviceid_node *d;
+
+	rcu_read_lock();
+	d = _lookup_deviceid(server->pnfs_curr_ld, server->nfs_client, id,
+			hash);
+	if (d != NULL && !atomic_inc_not_zero(&d->ref))
+		d = NULL;
+	rcu_read_unlock();
+	return d;
+}
+
+struct nfs4_deviceid_node *
+nfs4_find_get_deviceid(struct nfs_server *server,
+		const struct nfs4_deviceid *id, const struct cred *cred,
+		gfp_t gfp_mask)
+{
+	long hash = nfs4_deviceid_hash(id);
+	struct nfs4_deviceid_node *d, *new;
+
+	d = __nfs4_find_get_deviceid(server, id, hash);
+	if (d)
+		return d;
+
+	new = nfs4_get_device_info(server, id, cred, gfp_mask);
+	if (!new)
+		return new;
+
+	spin_lock(&nfs4_deviceid_lock);
+	d = __nfs4_find_get_deviceid(server, id, hash);
+	if (d) {
+		spin_unlock(&nfs4_deviceid_lock);
+		server->pnfs_curr_ld->free_deviceid_node(new);
+		return d;
+	}
+	hlist_add_head_rcu(&new->node, &nfs4_deviceid_cache[hash]);
+	atomic_inc(&new->ref);
+	spin_unlock(&nfs4_deviceid_lock);
+
+	return new;
+}
+EXPORT_SYMBOL_GPL(nfs4_find_get_deviceid);
+
+/*
+ * Remove a deviceid from cache
+ *
+ * @clp nfs_client associated with deviceid
+ * @id the deviceid to unhash
+ *
+ * @ret the unhashed node, if found and dereferenced to zero, NULL otherwise.
+ */
+void
+nfs4_delete_deviceid(const struct pnfs_layoutdriver_type *ld,
+			 const struct nfs_client *clp, const struct nfs4_deviceid *id)
+{
+	struct nfs4_deviceid_node *d;
+
+	spin_lock(&nfs4_deviceid_lock);
+	rcu_read_lock();
+	d = _lookup_deviceid(ld, clp, id, nfs4_deviceid_hash(id));
+	rcu_read_unlock();
+	if (!d) {
+		spin_unlock(&nfs4_deviceid_lock);
+		return;
+	}
+	hlist_del_init_rcu(&d->node);
+	clear_bit(NFS_DEVICEID_NOCACHE, &d->flags);
+	spin_unlock(&nfs4_deviceid_lock);
+
+	/* balance the initial ref set in pnfs_insert_deviceid */
+	nfs4_put_deviceid_node(d);
+}
+EXPORT_SYMBOL_GPL(nfs4_delete_deviceid);
+
+void
+nfs4_init_deviceid_node(struct nfs4_deviceid_node *d, struct nfs_server *server,
+			const struct nfs4_deviceid *id)
+{
+	INIT_HLIST_NODE(&d->node);
+	INIT_HLIST_NODE(&d->tmpnode);
+	d->ld = server->pnfs_curr_ld;
+	d->nfs_client = server->nfs_client;
+	d->flags = 0;
+	d->deviceid = *id;
+	atomic_set(&d->ref, 1);
+}
+EXPORT_SYMBOL_GPL(nfs4_init_deviceid_node);
+
+/*
+ * Dereference a deviceid node and delete it when its reference count drops
+ * to zero.
+ *
+ * @d deviceid node to put
+ *
+ * return true iff the node was deleted
+ * Note that since the test for d->ref == 0 is sufficient to establish
+ * that the node is no longer hashed in the global device id cache.
+ */
+bool
+nfs4_put_deviceid_node(struct nfs4_deviceid_node *d)
+{
+	if (test_bit(NFS_DEVICEID_NOCACHE, &d->flags)) {
+		if (atomic_add_unless(&d->ref, -1, 2))
+			return false;
+		nfs4_delete_deviceid(d->ld, d->nfs_client, &d->deviceid);
+	}
+	if (!atomic_dec_and_test(&d->ref))
+		return false;
+	d->ld->free_deviceid_node(d);
+	return true;
+}
+EXPORT_SYMBOL_GPL(nfs4_put_deviceid_node);
+
+void
+nfs4_mark_deviceid_available(struct nfs4_deviceid_node *node)
+{
+	if (test_bit(NFS_DEVICEID_UNAVAILABLE, &node->flags)) {
+		clear_bit(NFS_DEVICEID_UNAVAILABLE, &node->flags);
+		smp_mb__after_atomic();
+	}
+}
+EXPORT_SYMBOL_GPL(nfs4_mark_deviceid_available);
+
+void
+nfs4_mark_deviceid_unavailable(struct nfs4_deviceid_node *node)
+{
+	node->timestamp_unavailable = jiffies;
+	smp_mb__before_atomic();
+	set_bit(NFS_DEVICEID_UNAVAILABLE, &node->flags);
+	smp_mb__after_atomic();
+}
+EXPORT_SYMBOL_GPL(nfs4_mark_deviceid_unavailable);
+
+bool
+nfs4_test_deviceid_unavailable(struct nfs4_deviceid_node *node)
+{
+	if (test_bit(NFS_DEVICEID_UNAVAILABLE, &node->flags)) {
+		unsigned long start, end;
+
+		end = jiffies;
+		start = end - PNFS_DEVICE_RETRY_TIMEOUT;
+		if (time_in_range(node->timestamp_unavailable, start, end))
+			return true;
+		clear_bit(NFS_DEVICEID_UNAVAILABLE, &node->flags);
+		smp_mb__after_atomic();
+	}
+	return false;
+}
+EXPORT_SYMBOL_GPL(nfs4_test_deviceid_unavailable);
+
+static void
+_deviceid_purge_client(const struct nfs_client *clp, long hash)
+{
+	struct nfs4_deviceid_node *d;
+	HLIST_HEAD(tmp);
+
+	spin_lock(&nfs4_deviceid_lock);
+	rcu_read_lock();
+	hlist_for_each_entry_rcu(d, &nfs4_deviceid_cache[hash], node)
+		if (d->nfs_client == clp && atomic_read(&d->ref)) {
+			hlist_del_init_rcu(&d->node);
+			hlist_add_head(&d->tmpnode, &tmp);
+			clear_bit(NFS_DEVICEID_NOCACHE, &d->flags);
+		}
+	rcu_read_unlock();
+	spin_unlock(&nfs4_deviceid_lock);
+
+	if (hlist_empty(&tmp))
+		return;
+
+	while (!hlist_empty(&tmp)) {
+		d = hlist_entry(tmp.first, struct nfs4_deviceid_node, tmpnode);
+		hlist_del(&d->tmpnode);
+		nfs4_put_deviceid_node(d);
+	}
+}
+
+void
+nfs4_deviceid_purge_client(const struct nfs_client *clp)
+{
+	long h;
+
+	if (!(clp->cl_exchange_flags & EXCHGID4_FLAG_USE_PNFS_MDS))
+		return;
+	for (h = 0; h < NFS4_DEVICE_ID_HASH_SIZE; h++)
+		_deviceid_purge_client(clp, h);
+}
+
+/*
+ * Stop use of all deviceids associated with an nfs_client
+ */
+void
+nfs4_deviceid_mark_client_invalid(struct nfs_client *clp)
+{
+	struct nfs4_deviceid_node *d;
+	int i;
+
+	rcu_read_lock();
+	for (i = 0; i < NFS4_DEVICE_ID_HASH_SIZE; i ++){
+		hlist_for_each_entry_rcu(d, &nfs4_deviceid_cache[i], node)
+			if (d->nfs_client == clp)
+				set_bit(NFS_DEVICEID_INVALID, &d->flags);
+	}
+	rcu_read_unlock();
+}
diff --git a/fs/nfs/pnfs_nfs.c b/fs/nfs/pnfs_nfs.c
new file mode 100644
index 000000000..a2ad8bb87
--- /dev/null
+++ b/fs/nfs/pnfs_nfs.c
@@ -0,0 +1,1215 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Common NFS I/O  operations for the pnfs file based
+ * layout drivers.
+ *
+ * Copyright (c) 2014, Primary Data, Inc. All rights reserved.
+ *
+ * Tom Haynes <loghyr@primarydata.com>
+ */
+
+#include <linux/nfs_fs.h>
+#include <linux/nfs_page.h>
+#include <linux/sunrpc/addr.h>
+#include <linux/module.h>
+
+#include "nfs4session.h"
+#include "internal.h"
+#include "pnfs.h"
+
+#define NFSDBG_FACILITY		NFSDBG_PNFS
+
+void pnfs_generic_rw_release(void *data)
+{
+	struct nfs_pgio_header *hdr = data;
+
+	nfs_put_client(hdr->ds_clp);
+	hdr->mds_ops->rpc_release(data);
+}
+EXPORT_SYMBOL_GPL(pnfs_generic_rw_release);
+
+/* Fake up some data that will cause nfs_commit_release to retry the writes. */
+void pnfs_generic_prepare_to_resend_writes(struct nfs_commit_data *data)
+{
+	struct nfs_writeverf *verf = data->res.verf;
+
+	data->task.tk_status = 0;
+	memset(&verf->verifier, 0, sizeof(verf->verifier));
+	verf->committed = NFS_UNSTABLE;
+}
+EXPORT_SYMBOL_GPL(pnfs_generic_prepare_to_resend_writes);
+
+void pnfs_generic_write_commit_done(struct rpc_task *task, void *data)
+{
+	struct nfs_commit_data *wdata = data;
+
+	/* Note this may cause RPC to be resent */
+	wdata->mds_ops->rpc_call_done(task, data);
+}
+EXPORT_SYMBOL_GPL(pnfs_generic_write_commit_done);
+
+void pnfs_generic_commit_release(void *calldata)
+{
+	struct nfs_commit_data *data = calldata;
+
+	data->completion_ops->completion(data);
+	pnfs_put_lseg(data->lseg);
+	nfs_put_client(data->ds_clp);
+	nfs_commitdata_release(data);
+}
+EXPORT_SYMBOL_GPL(pnfs_generic_commit_release);
+
+static struct pnfs_layout_segment *
+pnfs_free_bucket_lseg(struct pnfs_commit_bucket *bucket)
+{
+	if (list_empty(&bucket->committing) && list_empty(&bucket->written)) {
+		struct pnfs_layout_segment *freeme = bucket->lseg;
+		bucket->lseg = NULL;
+		return freeme;
+	}
+	return NULL;
+}
+
+/* The generic layer is about to remove the req from the commit list.
+ * If this will make the bucket empty, it will need to put the lseg reference.
+ * Note this must be called holding nfsi->commit_mutex
+ */
+void
+pnfs_generic_clear_request_commit(struct nfs_page *req,
+				  struct nfs_commit_info *cinfo)
+{
+	struct pnfs_commit_bucket *bucket = NULL;
+
+	if (!test_and_clear_bit(PG_COMMIT_TO_DS, &req->wb_flags))
+		goto out;
+	cinfo->ds->nwritten--;
+	if (list_is_singular(&req->wb_list))
+		bucket = list_first_entry(&req->wb_list,
+					  struct pnfs_commit_bucket, written);
+out:
+	nfs_request_remove_commit_list(req, cinfo);
+	if (bucket)
+		pnfs_put_lseg(pnfs_free_bucket_lseg(bucket));
+}
+EXPORT_SYMBOL_GPL(pnfs_generic_clear_request_commit);
+
+struct pnfs_commit_array *
+pnfs_alloc_commit_array(size_t n, gfp_t gfp_flags)
+{
+	struct pnfs_commit_array *p;
+	struct pnfs_commit_bucket *b;
+
+	p = kmalloc(struct_size(p, buckets, n), gfp_flags);
+	if (!p)
+		return NULL;
+	p->nbuckets = n;
+	INIT_LIST_HEAD(&p->cinfo_list);
+	INIT_LIST_HEAD(&p->lseg_list);
+	p->lseg = NULL;
+	for (b = &p->buckets[0]; n != 0; b++, n--) {
+		INIT_LIST_HEAD(&b->written);
+		INIT_LIST_HEAD(&b->committing);
+		b->lseg = NULL;
+		b->direct_verf.committed = NFS_INVALID_STABLE_HOW;
+	}
+	return p;
+}
+EXPORT_SYMBOL_GPL(pnfs_alloc_commit_array);
+
+void
+pnfs_free_commit_array(struct pnfs_commit_array *p)
+{
+	kfree_rcu(p, rcu);
+}
+EXPORT_SYMBOL_GPL(pnfs_free_commit_array);
+
+static struct pnfs_commit_array *
+pnfs_find_commit_array_by_lseg(struct pnfs_ds_commit_info *fl_cinfo,
+		struct pnfs_layout_segment *lseg)
+{
+	struct pnfs_commit_array *array;
+
+	list_for_each_entry_rcu(array, &fl_cinfo->commits, cinfo_list) {
+		if (array->lseg == lseg)
+			return array;
+	}
+	return NULL;
+}
+
+struct pnfs_commit_array *
+pnfs_add_commit_array(struct pnfs_ds_commit_info *fl_cinfo,
+		struct pnfs_commit_array *new,
+		struct pnfs_layout_segment *lseg)
+{
+	struct pnfs_commit_array *array;
+
+	array = pnfs_find_commit_array_by_lseg(fl_cinfo, lseg);
+	if (array)
+		return array;
+	new->lseg = lseg;
+	refcount_set(&new->refcount, 1);
+	list_add_rcu(&new->cinfo_list, &fl_cinfo->commits);
+	list_add(&new->lseg_list, &lseg->pls_commits);
+	return new;
+}
+EXPORT_SYMBOL_GPL(pnfs_add_commit_array);
+
+static struct pnfs_commit_array *
+pnfs_lookup_commit_array(struct pnfs_ds_commit_info *fl_cinfo,
+		struct pnfs_layout_segment *lseg)
+{
+	struct pnfs_commit_array *array;
+
+	rcu_read_lock();
+	array = pnfs_find_commit_array_by_lseg(fl_cinfo, lseg);
+	if (!array) {
+		rcu_read_unlock();
+		fl_cinfo->ops->setup_ds_info(fl_cinfo, lseg);
+		rcu_read_lock();
+		array = pnfs_find_commit_array_by_lseg(fl_cinfo, lseg);
+	}
+	rcu_read_unlock();
+	return array;
+}
+
+static void
+pnfs_release_commit_array_locked(struct pnfs_commit_array *array)
+{
+	list_del_rcu(&array->cinfo_list);
+	list_del(&array->lseg_list);
+	pnfs_free_commit_array(array);
+}
+
+static void
+pnfs_put_commit_array_locked(struct pnfs_commit_array *array)
+{
+	if (refcount_dec_and_test(&array->refcount))
+		pnfs_release_commit_array_locked(array);
+}
+
+static void
+pnfs_put_commit_array(struct pnfs_commit_array *array, struct inode *inode)
+{
+	if (refcount_dec_and_lock(&array->refcount, &inode->i_lock)) {
+		pnfs_release_commit_array_locked(array);
+		spin_unlock(&inode->i_lock);
+	}
+}
+
+static struct pnfs_commit_array *
+pnfs_get_commit_array(struct pnfs_commit_array *array)
+{
+	if (refcount_inc_not_zero(&array->refcount))
+		return array;
+	return NULL;
+}
+
+static void
+pnfs_remove_and_free_commit_array(struct pnfs_commit_array *array)
+{
+	array->lseg = NULL;
+	list_del_init(&array->lseg_list);
+	pnfs_put_commit_array_locked(array);
+}
+
+void
+pnfs_generic_ds_cinfo_release_lseg(struct pnfs_ds_commit_info *fl_cinfo,
+		struct pnfs_layout_segment *lseg)
+{
+	struct pnfs_commit_array *array, *tmp;
+
+	list_for_each_entry_safe(array, tmp, &lseg->pls_commits, lseg_list)
+		pnfs_remove_and_free_commit_array(array);
+}
+EXPORT_SYMBOL_GPL(pnfs_generic_ds_cinfo_release_lseg);
+
+void
+pnfs_generic_ds_cinfo_destroy(struct pnfs_ds_commit_info *fl_cinfo)
+{
+	struct pnfs_commit_array *array, *tmp;
+
+	list_for_each_entry_safe(array, tmp, &fl_cinfo->commits, cinfo_list)
+		pnfs_remove_and_free_commit_array(array);
+}
+EXPORT_SYMBOL_GPL(pnfs_generic_ds_cinfo_destroy);
+
+/*
+ * Locks the nfs_page requests for commit and moves them to
+ * @bucket->committing.
+ */
+static int
+pnfs_bucket_scan_ds_commit_list(struct pnfs_commit_bucket *bucket,
+				struct nfs_commit_info *cinfo,
+				int max)
+{
+	struct list_head *src = &bucket->written;
+	struct list_head *dst = &bucket->committing;
+	int ret;
+
+	lockdep_assert_held(&NFS_I(cinfo->inode)->commit_mutex);
+	ret = nfs_scan_commit_list(src, dst, cinfo, max);
+	if (ret) {
+		cinfo->ds->nwritten -= ret;
+		cinfo->ds->ncommitting += ret;
+	}
+	return ret;
+}
+
+static int pnfs_bucket_scan_array(struct nfs_commit_info *cinfo,
+				  struct pnfs_commit_bucket *buckets,
+				  unsigned int nbuckets,
+				  int max)
+{
+	unsigned int i;
+	int rv = 0, cnt;
+
+	for (i = 0; i < nbuckets && max != 0; i++) {
+		cnt = pnfs_bucket_scan_ds_commit_list(&buckets[i], cinfo, max);
+		rv += cnt;
+		max -= cnt;
+	}
+	return rv;
+}
+
+/* Move reqs from written to committing lists, returning count
+ * of number moved.
+ */
+int pnfs_generic_scan_commit_lists(struct nfs_commit_info *cinfo, int max)
+{
+	struct pnfs_ds_commit_info *fl_cinfo = cinfo->ds;
+	struct pnfs_commit_array *array;
+	int rv = 0, cnt;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(array, &fl_cinfo->commits, cinfo_list) {
+		if (!array->lseg || !pnfs_get_commit_array(array))
+			continue;
+		rcu_read_unlock();
+		cnt = pnfs_bucket_scan_array(cinfo, array->buckets,
+				array->nbuckets, max);
+		rcu_read_lock();
+		pnfs_put_commit_array(array, cinfo->inode);
+		rv += cnt;
+		max -= cnt;
+		if (!max)
+			break;
+	}
+	rcu_read_unlock();
+	return rv;
+}
+EXPORT_SYMBOL_GPL(pnfs_generic_scan_commit_lists);
+
+static unsigned int
+pnfs_bucket_recover_commit_reqs(struct list_head *dst,
+			        struct pnfs_commit_bucket *buckets,
+				unsigned int nbuckets,
+				struct nfs_commit_info *cinfo)
+{
+	struct pnfs_commit_bucket *b;
+	struct pnfs_layout_segment *freeme;
+	unsigned int nwritten, ret = 0;
+	unsigned int i;
+
+restart:
+	for (i = 0, b = buckets; i < nbuckets; i++, b++) {
+		nwritten = nfs_scan_commit_list(&b->written, dst, cinfo, 0);
+		if (!nwritten)
+			continue;
+		ret += nwritten;
+		freeme = pnfs_free_bucket_lseg(b);
+		if (freeme) {
+			pnfs_put_lseg(freeme);
+			goto restart;
+		}
+	}
+	return ret;
+}
+
+/* Pull everything off the committing lists and dump into @dst.  */
+void pnfs_generic_recover_commit_reqs(struct list_head *dst,
+				      struct nfs_commit_info *cinfo)
+{
+	struct pnfs_ds_commit_info *fl_cinfo = cinfo->ds;
+	struct pnfs_commit_array *array;
+	unsigned int nwritten;
+
+	lockdep_assert_held(&NFS_I(cinfo->inode)->commit_mutex);
+	rcu_read_lock();
+	list_for_each_entry_rcu(array, &fl_cinfo->commits, cinfo_list) {
+		if (!array->lseg || !pnfs_get_commit_array(array))
+			continue;
+		rcu_read_unlock();
+		nwritten = pnfs_bucket_recover_commit_reqs(dst,
+							   array->buckets,
+							   array->nbuckets,
+							   cinfo);
+		rcu_read_lock();
+		pnfs_put_commit_array(array, cinfo->inode);
+		fl_cinfo->nwritten -= nwritten;
+	}
+	rcu_read_unlock();
+}
+EXPORT_SYMBOL_GPL(pnfs_generic_recover_commit_reqs);
+
+static struct nfs_page *
+pnfs_bucket_search_commit_reqs(struct pnfs_commit_bucket *buckets,
+		unsigned int nbuckets, struct page *page)
+{
+	struct nfs_page *req;
+	struct pnfs_commit_bucket *b;
+	unsigned int i;
+
+	/* Linearly search the commit lists for each bucket until a matching
+	 * request is found */
+	for (i = 0, b = buckets; i < nbuckets; i++, b++) {
+		list_for_each_entry(req, &b->written, wb_list) {
+			if (req->wb_page == page)
+				return req->wb_head;
+		}
+		list_for_each_entry(req, &b->committing, wb_list) {
+			if (req->wb_page == page)
+				return req->wb_head;
+		}
+	}
+	return NULL;
+}
+
+/* pnfs_generic_search_commit_reqs - Search lists in @cinfo for the head reqest
+ *				   for @page
+ * @cinfo - commit info for current inode
+ * @page - page to search for matching head request
+ *
+ * Returns a the head request if one is found, otherwise returns NULL.
+ */
+struct nfs_page *
+pnfs_generic_search_commit_reqs(struct nfs_commit_info *cinfo, struct page *page)
+{
+	struct pnfs_ds_commit_info *fl_cinfo = cinfo->ds;
+	struct pnfs_commit_array *array;
+	struct nfs_page *req;
+
+	list_for_each_entry(array, &fl_cinfo->commits, cinfo_list) {
+		req = pnfs_bucket_search_commit_reqs(array->buckets,
+				array->nbuckets, page);
+		if (req)
+			return req;
+	}
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(pnfs_generic_search_commit_reqs);
+
+static struct pnfs_layout_segment *
+pnfs_bucket_get_committing(struct list_head *head,
+			   struct pnfs_commit_bucket *bucket,
+			   struct nfs_commit_info *cinfo)
+{
+	struct pnfs_layout_segment *lseg;
+	struct list_head *pos;
+
+	list_for_each(pos, &bucket->committing)
+		cinfo->ds->ncommitting--;
+	list_splice_init(&bucket->committing, head);
+	lseg = pnfs_free_bucket_lseg(bucket);
+	if (!lseg)
+		lseg = pnfs_get_lseg(bucket->lseg);
+	return lseg;
+}
+
+static struct nfs_commit_data *
+pnfs_bucket_fetch_commitdata(struct pnfs_commit_bucket *bucket,
+			     struct nfs_commit_info *cinfo)
+{
+	struct nfs_commit_data *data = nfs_commitdata_alloc();
+
+	if (!data)
+		return NULL;
+	data->lseg = pnfs_bucket_get_committing(&data->pages, bucket, cinfo);
+	return data;
+}
+
+static void pnfs_generic_retry_commit(struct pnfs_commit_bucket *buckets,
+				      unsigned int nbuckets,
+				      struct nfs_commit_info *cinfo,
+				      unsigned int idx)
+{
+	struct pnfs_commit_bucket *bucket;
+	struct pnfs_layout_segment *freeme;
+	LIST_HEAD(pages);
+
+	for (bucket = buckets; idx < nbuckets; bucket++, idx++) {
+		if (list_empty(&bucket->committing))
+			continue;
+		mutex_lock(&NFS_I(cinfo->inode)->commit_mutex);
+		freeme = pnfs_bucket_get_committing(&pages, bucket, cinfo);
+		mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);
+		nfs_retry_commit(&pages, freeme, cinfo, idx);
+		pnfs_put_lseg(freeme);
+	}
+}
+
+static unsigned int
+pnfs_bucket_alloc_ds_commits(struct list_head *list,
+			     struct pnfs_commit_bucket *buckets,
+			     unsigned int nbuckets,
+			     struct nfs_commit_info *cinfo)
+{
+	struct pnfs_commit_bucket *bucket;
+	struct nfs_commit_data *data;
+	unsigned int i;
+	unsigned int nreq = 0;
+
+	for (i = 0, bucket = buckets; i < nbuckets; i++, bucket++) {
+		if (list_empty(&bucket->committing))
+			continue;
+		mutex_lock(&NFS_I(cinfo->inode)->commit_mutex);
+		if (!list_empty(&bucket->committing)) {
+			data = pnfs_bucket_fetch_commitdata(bucket, cinfo);
+			if (!data)
+				goto out_error;
+			data->ds_commit_index = i;
+			list_add_tail(&data->list, list);
+			nreq++;
+		}
+		mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);
+	}
+	return nreq;
+out_error:
+	mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);
+	/* Clean up on error */
+	pnfs_generic_retry_commit(buckets, nbuckets, cinfo, i);
+	return nreq;
+}
+
+static unsigned int
+pnfs_alloc_ds_commits_list(struct list_head *list,
+			   struct pnfs_ds_commit_info *fl_cinfo,
+			   struct nfs_commit_info *cinfo)
+{
+	struct pnfs_commit_array *array;
+	unsigned int ret = 0;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(array, &fl_cinfo->commits, cinfo_list) {
+		if (!array->lseg || !pnfs_get_commit_array(array))
+			continue;
+		rcu_read_unlock();
+		ret += pnfs_bucket_alloc_ds_commits(list, array->buckets,
+				array->nbuckets, cinfo);
+		rcu_read_lock();
+		pnfs_put_commit_array(array, cinfo->inode);
+	}
+	rcu_read_unlock();
+	return ret;
+}
+
+/* This follows nfs_commit_list pretty closely */
+int
+pnfs_generic_commit_pagelist(struct inode *inode, struct list_head *mds_pages,
+			     int how, struct nfs_commit_info *cinfo,
+			     int (*initiate_commit)(struct nfs_commit_data *data,
+						    int how))
+{
+	struct pnfs_ds_commit_info *fl_cinfo = cinfo->ds;
+	struct nfs_commit_data *data, *tmp;
+	LIST_HEAD(list);
+	unsigned int nreq = 0;
+
+	if (!list_empty(mds_pages)) {
+		data = nfs_commitdata_alloc();
+		if (!data) {
+			nfs_retry_commit(mds_pages, NULL, cinfo, -1);
+			return -ENOMEM;
+		}
+		data->ds_commit_index = -1;
+		list_splice_init(mds_pages, &data->pages);
+		list_add_tail(&data->list, &list);
+		nreq++;
+	}
+
+	nreq += pnfs_alloc_ds_commits_list(&list, fl_cinfo, cinfo);
+	if (nreq == 0)
+		goto out;
+
+	list_for_each_entry_safe(data, tmp, &list, list) {
+		list_del(&data->list);
+		if (data->ds_commit_index < 0) {
+			nfs_init_commit(data, NULL, NULL, cinfo);
+			nfs_initiate_commit(NFS_CLIENT(inode), data,
+					    NFS_PROTO(data->inode),
+					    data->mds_ops, how,
+					    RPC_TASK_CRED_NOREF);
+		} else {
+			nfs_init_commit(data, NULL, data->lseg, cinfo);
+			initiate_commit(data, how);
+		}
+	}
+out:
+	return PNFS_ATTEMPTED;
+}
+EXPORT_SYMBOL_GPL(pnfs_generic_commit_pagelist);
+
+/*
+ * Data server cache
+ *
+ * Data servers can be mapped to different device ids.
+ * nfs4_pnfs_ds reference counting
+ *   - set to 1 on allocation
+ *   - incremented when a device id maps a data server already in the cache.
+ *   - decremented when deviceid is removed from the cache.
+ */
+static DEFINE_SPINLOCK(nfs4_ds_cache_lock);
+static LIST_HEAD(nfs4_data_server_cache);
+
+/* Debug routines */
+static void
+print_ds(struct nfs4_pnfs_ds *ds)
+{
+	if (ds == NULL) {
+		printk(KERN_WARNING "%s NULL device\n", __func__);
+		return;
+	}
+	printk(KERN_WARNING "        ds %s\n"
+		"        ref count %d\n"
+		"        client %p\n"
+		"        cl_exchange_flags %x\n",
+		ds->ds_remotestr,
+		refcount_read(&ds->ds_count), ds->ds_clp,
+		ds->ds_clp ? ds->ds_clp->cl_exchange_flags : 0);
+}
+
+static bool
+same_sockaddr(struct sockaddr *addr1, struct sockaddr *addr2)
+{
+	struct sockaddr_in *a, *b;
+	struct sockaddr_in6 *a6, *b6;
+
+	if (addr1->sa_family != addr2->sa_family)
+		return false;
+
+	switch (addr1->sa_family) {
+	case AF_INET:
+		a = (struct sockaddr_in *)addr1;
+		b = (struct sockaddr_in *)addr2;
+
+		if (a->sin_addr.s_addr == b->sin_addr.s_addr &&
+		    a->sin_port == b->sin_port)
+			return true;
+		break;
+
+	case AF_INET6:
+		a6 = (struct sockaddr_in6 *)addr1;
+		b6 = (struct sockaddr_in6 *)addr2;
+
+		/* LINKLOCAL addresses must have matching scope_id */
+		if (ipv6_addr_src_scope(&a6->sin6_addr) ==
+		    IPV6_ADDR_SCOPE_LINKLOCAL &&
+		    a6->sin6_scope_id != b6->sin6_scope_id)
+			return false;
+
+		if (ipv6_addr_equal(&a6->sin6_addr, &b6->sin6_addr) &&
+		    a6->sin6_port == b6->sin6_port)
+			return true;
+		break;
+
+	default:
+		dprintk("%s: unhandled address family: %u\n",
+			__func__, addr1->sa_family);
+		return false;
+	}
+
+	return false;
+}
+
+/*
+ * Checks if 'dsaddrs1' contains a subset of 'dsaddrs2'. If it does,
+ * declare a match.
+ */
+static bool
+_same_data_server_addrs_locked(const struct list_head *dsaddrs1,
+			       const struct list_head *dsaddrs2)
+{
+	struct nfs4_pnfs_ds_addr *da1, *da2;
+	struct sockaddr *sa1, *sa2;
+	bool match = false;
+
+	list_for_each_entry(da1, dsaddrs1, da_node) {
+		sa1 = (struct sockaddr *)&da1->da_addr;
+		match = false;
+		list_for_each_entry(da2, dsaddrs2, da_node) {
+			sa2 = (struct sockaddr *)&da2->da_addr;
+			match = same_sockaddr(sa1, sa2);
+			if (match)
+				break;
+		}
+		if (!match)
+			break;
+	}
+	return match;
+}
+
+/*
+ * Lookup DS by addresses.  nfs4_ds_cache_lock is held
+ */
+static struct nfs4_pnfs_ds *
+_data_server_lookup_locked(const struct list_head *dsaddrs)
+{
+	struct nfs4_pnfs_ds *ds;
+
+	list_for_each_entry(ds, &nfs4_data_server_cache, ds_node)
+		if (_same_data_server_addrs_locked(&ds->ds_addrs, dsaddrs))
+			return ds;
+	return NULL;
+}
+
+static void destroy_ds(struct nfs4_pnfs_ds *ds)
+{
+	struct nfs4_pnfs_ds_addr *da;
+
+	dprintk("--> %s\n", __func__);
+	ifdebug(FACILITY)
+		print_ds(ds);
+
+	nfs_put_client(ds->ds_clp);
+
+	while (!list_empty(&ds->ds_addrs)) {
+		da = list_first_entry(&ds->ds_addrs,
+				      struct nfs4_pnfs_ds_addr,
+				      da_node);
+		list_del_init(&da->da_node);
+		kfree(da->da_remotestr);
+		kfree(da);
+	}
+
+	kfree(ds->ds_remotestr);
+	kfree(ds);
+}
+
+void nfs4_pnfs_ds_put(struct nfs4_pnfs_ds *ds)
+{
+	if (refcount_dec_and_lock(&ds->ds_count,
+				&nfs4_ds_cache_lock)) {
+		list_del_init(&ds->ds_node);
+		spin_unlock(&nfs4_ds_cache_lock);
+		destroy_ds(ds);
+	}
+}
+EXPORT_SYMBOL_GPL(nfs4_pnfs_ds_put);
+
+/*
+ * Create a string with a human readable address and port to avoid
+ * complicated setup around many dprinks.
+ */
+static char *
+nfs4_pnfs_remotestr(struct list_head *dsaddrs, gfp_t gfp_flags)
+{
+	struct nfs4_pnfs_ds_addr *da;
+	char *remotestr;
+	size_t len;
+	char *p;
+
+	len = 3;        /* '{', '}' and eol */
+	list_for_each_entry(da, dsaddrs, da_node) {
+		len += strlen(da->da_remotestr) + 1;    /* string plus comma */
+	}
+
+	remotestr = kzalloc(len, gfp_flags);
+	if (!remotestr)
+		return NULL;
+
+	p = remotestr;
+	*(p++) = '{';
+	len--;
+	list_for_each_entry(da, dsaddrs, da_node) {
+		size_t ll = strlen(da->da_remotestr);
+
+		if (ll > len)
+			goto out_err;
+
+		memcpy(p, da->da_remotestr, ll);
+		p += ll;
+		len -= ll;
+
+		if (len < 1)
+			goto out_err;
+		(*p++) = ',';
+		len--;
+	}
+	if (len < 2)
+		goto out_err;
+	*(p++) = '}';
+	*p = '\0';
+	return remotestr;
+out_err:
+	kfree(remotestr);
+	return NULL;
+}
+
+/*
+ * Given a list of multipath struct nfs4_pnfs_ds_addr, add it to ds cache if
+ * uncached and return cached struct nfs4_pnfs_ds.
+ */
+struct nfs4_pnfs_ds *
+nfs4_pnfs_ds_add(struct list_head *dsaddrs, gfp_t gfp_flags)
+{
+	struct nfs4_pnfs_ds *tmp_ds, *ds = NULL;
+	char *remotestr;
+
+	if (list_empty(dsaddrs)) {
+		dprintk("%s: no addresses defined\n", __func__);
+		goto out;
+	}
+
+	ds = kzalloc(sizeof(*ds), gfp_flags);
+	if (!ds)
+		goto out;
+
+	/* this is only used for debugging, so it's ok if its NULL */
+	remotestr = nfs4_pnfs_remotestr(dsaddrs, gfp_flags);
+
+	spin_lock(&nfs4_ds_cache_lock);
+	tmp_ds = _data_server_lookup_locked(dsaddrs);
+	if (tmp_ds == NULL) {
+		INIT_LIST_HEAD(&ds->ds_addrs);
+		list_splice_init(dsaddrs, &ds->ds_addrs);
+		ds->ds_remotestr = remotestr;
+		refcount_set(&ds->ds_count, 1);
+		INIT_LIST_HEAD(&ds->ds_node);
+		ds->ds_clp = NULL;
+		list_add(&ds->ds_node, &nfs4_data_server_cache);
+		dprintk("%s add new data server %s\n", __func__,
+			ds->ds_remotestr);
+	} else {
+		kfree(remotestr);
+		kfree(ds);
+		refcount_inc(&tmp_ds->ds_count);
+		dprintk("%s data server %s found, inc'ed ds_count to %d\n",
+			__func__, tmp_ds->ds_remotestr,
+			refcount_read(&tmp_ds->ds_count));
+		ds = tmp_ds;
+	}
+	spin_unlock(&nfs4_ds_cache_lock);
+out:
+	return ds;
+}
+EXPORT_SYMBOL_GPL(nfs4_pnfs_ds_add);
+
+static int nfs4_wait_ds_connect(struct nfs4_pnfs_ds *ds)
+{
+	might_sleep();
+	return wait_on_bit(&ds->ds_state, NFS4DS_CONNECTING, TASK_KILLABLE);
+}
+
+static void nfs4_clear_ds_conn_bit(struct nfs4_pnfs_ds *ds)
+{
+	smp_mb__before_atomic();
+	clear_and_wake_up_bit(NFS4DS_CONNECTING, &ds->ds_state);
+}
+
+static struct nfs_client *(*get_v3_ds_connect)(
+			struct nfs_server *mds_srv,
+			const struct sockaddr *ds_addr,
+			int ds_addrlen,
+			int ds_proto,
+			unsigned int ds_timeo,
+			unsigned int ds_retrans);
+
+static bool load_v3_ds_connect(void)
+{
+	if (!get_v3_ds_connect) {
+		get_v3_ds_connect = symbol_request(nfs3_set_ds_client);
+		WARN_ON_ONCE(!get_v3_ds_connect);
+	}
+
+	return(get_v3_ds_connect != NULL);
+}
+
+void nfs4_pnfs_v3_ds_connect_unload(void)
+{
+	if (get_v3_ds_connect) {
+		symbol_put(nfs3_set_ds_client);
+		get_v3_ds_connect = NULL;
+	}
+}
+
+static int _nfs4_pnfs_v3_ds_connect(struct nfs_server *mds_srv,
+				 struct nfs4_pnfs_ds *ds,
+				 unsigned int timeo,
+				 unsigned int retrans)
+{
+	struct nfs_client *clp = ERR_PTR(-EIO);
+	struct nfs4_pnfs_ds_addr *da;
+	int status = 0;
+
+	dprintk("--> %s DS %s\n", __func__, ds->ds_remotestr);
+
+	if (!load_v3_ds_connect())
+		goto out;
+
+	list_for_each_entry(da, &ds->ds_addrs, da_node) {
+		dprintk("%s: DS %s: trying address %s\n",
+			__func__, ds->ds_remotestr, da->da_remotestr);
+
+		if (!IS_ERR(clp)) {
+			struct xprt_create xprt_args = {
+				.ident = XPRT_TRANSPORT_TCP,
+				.net = clp->cl_net,
+				.dstaddr = (struct sockaddr *)&da->da_addr,
+				.addrlen = da->da_addrlen,
+				.servername = clp->cl_hostname,
+			};
+			/* Add this address as an alias */
+			rpc_clnt_add_xprt(clp->cl_rpcclient, &xprt_args,
+					rpc_clnt_test_and_add_xprt, NULL);
+			continue;
+		}
+		clp = get_v3_ds_connect(mds_srv,
+				(struct sockaddr *)&da->da_addr,
+				da->da_addrlen, IPPROTO_TCP,
+				timeo, retrans);
+		if (IS_ERR(clp))
+			continue;
+		clp->cl_rpcclient->cl_softerr = 0;
+		clp->cl_rpcclient->cl_softrtry = 0;
+	}
+
+	if (IS_ERR(clp)) {
+		status = PTR_ERR(clp);
+		goto out;
+	}
+
+	smp_wmb();
+	WRITE_ONCE(ds->ds_clp, clp);
+	dprintk("%s [new] addr: %s\n", __func__, ds->ds_remotestr);
+out:
+	return status;
+}
+
+static int _nfs4_pnfs_v4_ds_connect(struct nfs_server *mds_srv,
+				 struct nfs4_pnfs_ds *ds,
+				 unsigned int timeo,
+				 unsigned int retrans,
+				 u32 minor_version)
+{
+	struct nfs_client *clp = ERR_PTR(-EIO);
+	struct nfs4_pnfs_ds_addr *da;
+	int status = 0;
+
+	dprintk("--> %s DS %s\n", __func__, ds->ds_remotestr);
+
+	list_for_each_entry(da, &ds->ds_addrs, da_node) {
+		dprintk("%s: DS %s: trying address %s\n",
+			__func__, ds->ds_remotestr, da->da_remotestr);
+
+		if (!IS_ERR(clp) && clp->cl_mvops->session_trunk) {
+			struct xprt_create xprt_args = {
+				.ident = XPRT_TRANSPORT_TCP,
+				.net = clp->cl_net,
+				.dstaddr = (struct sockaddr *)&da->da_addr,
+				.addrlen = da->da_addrlen,
+				.servername = clp->cl_hostname,
+			};
+			struct nfs4_add_xprt_data xprtdata = {
+				.clp = clp,
+				.cred = nfs4_get_clid_cred(clp),
+			};
+			struct rpc_add_xprt_test rpcdata = {
+				.add_xprt_test = clp->cl_mvops->session_trunk,
+				.data = &xprtdata,
+			};
+
+			/**
+			* Test this address for session trunking and
+			* add as an alias
+			*/
+			rpc_clnt_add_xprt(clp->cl_rpcclient, &xprt_args,
+					  rpc_clnt_setup_test_and_add_xprt,
+					  &rpcdata);
+			if (xprtdata.cred)
+				put_cred(xprtdata.cred);
+		} else {
+			clp = nfs4_set_ds_client(mds_srv,
+						(struct sockaddr *)&da->da_addr,
+						da->da_addrlen, IPPROTO_TCP,
+						timeo, retrans, minor_version);
+			if (IS_ERR(clp))
+				continue;
+
+			status = nfs4_init_ds_session(clp,
+					mds_srv->nfs_client->cl_lease_time);
+			if (status) {
+				nfs_put_client(clp);
+				clp = ERR_PTR(-EIO);
+				continue;
+			}
+
+		}
+	}
+
+	if (IS_ERR(clp)) {
+		status = PTR_ERR(clp);
+		goto out;
+	}
+
+	smp_wmb();
+	WRITE_ONCE(ds->ds_clp, clp);
+	dprintk("%s [new] addr: %s\n", __func__, ds->ds_remotestr);
+out:
+	return status;
+}
+
+/*
+ * Create an rpc connection to the nfs4_pnfs_ds data server.
+ * Currently only supports IPv4 and IPv6 addresses.
+ * If connection fails, make devid unavailable and return a -errno.
+ */
+int nfs4_pnfs_ds_connect(struct nfs_server *mds_srv, struct nfs4_pnfs_ds *ds,
+			  struct nfs4_deviceid_node *devid, unsigned int timeo,
+			  unsigned int retrans, u32 version, u32 minor_version)
+{
+	int err;
+
+	do {
+		err = nfs4_wait_ds_connect(ds);
+		if (err || ds->ds_clp)
+			goto out;
+		if (nfs4_test_deviceid_unavailable(devid))
+			return -ENODEV;
+	} while (test_and_set_bit(NFS4DS_CONNECTING, &ds->ds_state) != 0);
+
+	if (ds->ds_clp)
+		goto connect_done;
+
+	switch (version) {
+	case 3:
+		err = _nfs4_pnfs_v3_ds_connect(mds_srv, ds, timeo, retrans);
+		break;
+	case 4:
+		err = _nfs4_pnfs_v4_ds_connect(mds_srv, ds, timeo, retrans,
+					       minor_version);
+		break;
+	default:
+		dprintk("%s: unsupported DS version %d\n", __func__, version);
+		err = -EPROTONOSUPPORT;
+	}
+
+connect_done:
+	nfs4_clear_ds_conn_bit(ds);
+out:
+	/*
+	 * At this point the ds->ds_clp should be ready, but it might have
+	 * hit an error.
+	 */
+	if (!err) {
+		if (!ds->ds_clp || !nfs_client_init_is_complete(ds->ds_clp)) {
+			WARN_ON_ONCE(ds->ds_clp ||
+				!nfs4_test_deviceid_unavailable(devid));
+			return -EINVAL;
+		}
+		err = nfs_client_init_status(ds->ds_clp);
+	}
+
+	return err;
+}
+EXPORT_SYMBOL_GPL(nfs4_pnfs_ds_connect);
+
+/*
+ * Currently only supports ipv4, ipv6 and one multi-path address.
+ */
+struct nfs4_pnfs_ds_addr *
+nfs4_decode_mp_ds_addr(struct net *net, struct xdr_stream *xdr, gfp_t gfp_flags)
+{
+	struct nfs4_pnfs_ds_addr *da = NULL;
+	char *buf, *portstr;
+	__be16 port;
+	int nlen, rlen;
+	int tmp[2];
+	__be32 *p;
+	char *netid, *match_netid;
+	size_t len, match_netid_len;
+	char *startsep = "";
+	char *endsep = "";
+
+
+	/* r_netid */
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(!p))
+		goto out_err;
+	nlen = be32_to_cpup(p++);
+
+	p = xdr_inline_decode(xdr, nlen);
+	if (unlikely(!p))
+		goto out_err;
+
+	netid = kmalloc(nlen+1, gfp_flags);
+	if (unlikely(!netid))
+		goto out_err;
+
+	netid[nlen] = '\0';
+	memcpy(netid, p, nlen);
+
+	/* r_addr: ip/ip6addr with port in dec octets - see RFC 5665 */
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(!p))
+		goto out_free_netid;
+	rlen = be32_to_cpup(p);
+
+	p = xdr_inline_decode(xdr, rlen);
+	if (unlikely(!p))
+		goto out_free_netid;
+
+	/* port is ".ABC.DEF", 8 chars max */
+	if (rlen > INET6_ADDRSTRLEN + IPV6_SCOPE_ID_LEN + 8) {
+		dprintk("%s: Invalid address, length %d\n", __func__,
+			rlen);
+		goto out_free_netid;
+	}
+	buf = kmalloc(rlen + 1, gfp_flags);
+	if (!buf) {
+		dprintk("%s: Not enough memory\n", __func__);
+		goto out_free_netid;
+	}
+	buf[rlen] = '\0';
+	memcpy(buf, p, rlen);
+
+	/* replace port '.' with '-' */
+	portstr = strrchr(buf, '.');
+	if (!portstr) {
+		dprintk("%s: Failed finding expected dot in port\n",
+			__func__);
+		goto out_free_buf;
+	}
+	*portstr = '-';
+
+	/* find '.' between address and port */
+	portstr = strrchr(buf, '.');
+	if (!portstr) {
+		dprintk("%s: Failed finding expected dot between address and "
+			"port\n", __func__);
+		goto out_free_buf;
+	}
+	*portstr = '\0';
+
+	da = kzalloc(sizeof(*da), gfp_flags);
+	if (unlikely(!da))
+		goto out_free_buf;
+
+	INIT_LIST_HEAD(&da->da_node);
+
+	if (!rpc_pton(net, buf, portstr-buf, (struct sockaddr *)&da->da_addr,
+		      sizeof(da->da_addr))) {
+		dprintk("%s: error parsing address %s\n", __func__, buf);
+		goto out_free_da;
+	}
+
+	portstr++;
+	sscanf(portstr, "%d-%d", &tmp[0], &tmp[1]);
+	port = htons((tmp[0] << 8) | (tmp[1]));
+
+	switch (da->da_addr.ss_family) {
+	case AF_INET:
+		((struct sockaddr_in *)&da->da_addr)->sin_port = port;
+		da->da_addrlen = sizeof(struct sockaddr_in);
+		match_netid = "tcp";
+		match_netid_len = 3;
+		break;
+
+	case AF_INET6:
+		((struct sockaddr_in6 *)&da->da_addr)->sin6_port = port;
+		da->da_addrlen = sizeof(struct sockaddr_in6);
+		match_netid = "tcp6";
+		match_netid_len = 4;
+		startsep = "[";
+		endsep = "]";
+		break;
+
+	default:
+		dprintk("%s: unsupported address family: %u\n",
+			__func__, da->da_addr.ss_family);
+		goto out_free_da;
+	}
+
+	if (nlen != match_netid_len || strncmp(netid, match_netid, nlen)) {
+		dprintk("%s: ERROR: r_netid \"%s\" != \"%s\"\n",
+			__func__, netid, match_netid);
+		goto out_free_da;
+	}
+
+	/* save human readable address */
+	len = strlen(startsep) + strlen(buf) + strlen(endsep) + 7;
+	da->da_remotestr = kzalloc(len, gfp_flags);
+
+	/* NULL is ok, only used for dprintk */
+	if (da->da_remotestr)
+		snprintf(da->da_remotestr, len, "%s%s%s:%u", startsep,
+			 buf, endsep, ntohs(port));
+
+	dprintk("%s: Parsed DS addr %s\n", __func__, da->da_remotestr);
+	kfree(buf);
+	kfree(netid);
+	return da;
+
+out_free_da:
+	kfree(da);
+out_free_buf:
+	dprintk("%s: Error parsing DS addr: %s\n", __func__, buf);
+	kfree(buf);
+out_free_netid:
+	kfree(netid);
+out_err:
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(nfs4_decode_mp_ds_addr);
+
+void
+pnfs_layout_mark_request_commit(struct nfs_page *req,
+				struct pnfs_layout_segment *lseg,
+				struct nfs_commit_info *cinfo,
+				u32 ds_commit_idx)
+{
+	struct list_head *list;
+	struct pnfs_commit_array *array;
+	struct pnfs_commit_bucket *bucket;
+
+	mutex_lock(&NFS_I(cinfo->inode)->commit_mutex);
+	array = pnfs_lookup_commit_array(cinfo->ds, lseg);
+	if (!array || !pnfs_is_valid_lseg(lseg))
+		goto out_resched;
+	bucket = &array->buckets[ds_commit_idx];
+	list = &bucket->written;
+	/* Non-empty buckets hold a reference on the lseg.  That ref
+	 * is normally transferred to the COMMIT call and released
+	 * there.  It could also be released if the last req is pulled
+	 * off due to a rewrite, in which case it will be done in
+	 * pnfs_common_clear_request_commit
+	 */
+	if (!bucket->lseg)
+		bucket->lseg = pnfs_get_lseg(lseg);
+	set_bit(PG_COMMIT_TO_DS, &req->wb_flags);
+	cinfo->ds->nwritten++;
+
+	nfs_request_add_commit_list_locked(req, list, cinfo);
+	mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);
+	nfs_mark_page_unstable(req->wb_page, cinfo);
+	return;
+out_resched:
+	mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);
+	cinfo->completion_ops->resched_write(cinfo, req);
+}
+EXPORT_SYMBOL_GPL(pnfs_layout_mark_request_commit);
+
+int
+pnfs_nfs_generic_sync(struct inode *inode, bool datasync)
+{
+	int ret;
+
+	if (!pnfs_layoutcommit_outstanding(inode))
+		return 0;
+	ret = nfs_commit_inode(inode, FLUSH_SYNC);
+	if (ret < 0)
+		return ret;
+	if (datasync)
+		return 0;
+	return pnfs_layoutcommit_inode(inode, true);
+}
+EXPORT_SYMBOL_GPL(pnfs_nfs_generic_sync);
+
diff --git a/fs/nfs/proc.c b/fs/nfs/proc.c
new file mode 100644
index 000000000..15c865cc8
--- /dev/null
+++ b/fs/nfs/proc.c
@@ -0,0 +1,763 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  linux/fs/nfs/proc.c
+ *
+ *  Copyright (C) 1992, 1993, 1994  Rick Sladkey
+ *
+ *  OS-independent nfs remote procedure call functions
+ *
+ *  Tuned by Alan Cox <A.Cox@swansea.ac.uk> for >3K buffers
+ *  so at last we can have decent(ish) throughput off a 
+ *  Sun server.
+ *
+ *  Coding optimized and cleaned up by Florian La Roche.
+ *  Note: Error returns are optimized for NFS_OK, which isn't translated via
+ *  nfs_stat_to_errno(), but happens to be already the right return code.
+ *
+ *  Also, the code currently doesn't check the size of the packet, when
+ *  it decodes the packet.
+ *
+ *  Feel free to fix it and mail me the diffs if it worries you.
+ *
+ *  Completely rewritten to support the new RPC call interface;
+ *  rewrote and moved the entire XDR stuff to xdr.c
+ *  --Olaf Kirch June 1996
+ *
+ *  The code below initializes all auto variables explicitly, otherwise
+ *  it will fail to work as a module (gcc generates a memset call for an
+ *  incomplete struct).
+ */
+
+#include <linux/types.h>
+#include <linux/param.h>
+#include <linux/time.h>
+#include <linux/mm.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/in.h>
+#include <linux/pagemap.h>
+#include <linux/sunrpc/clnt.h>
+#include <linux/nfs.h>
+#include <linux/nfs2.h>
+#include <linux/nfs_fs.h>
+#include <linux/nfs_page.h>
+#include <linux/lockd/bind.h>
+#include <linux/freezer.h>
+#include "internal.h"
+
+#define NFSDBG_FACILITY		NFSDBG_PROC
+
+/*
+ * Bare-bones access to getattr: this is for nfs_read_super.
+ */
+static int
+nfs_proc_get_root(struct nfs_server *server, struct nfs_fh *fhandle,
+		  struct nfs_fsinfo *info)
+{
+	struct nfs_fattr *fattr = info->fattr;
+	struct nfs2_fsstat fsinfo;
+	struct rpc_message msg = {
+		.rpc_proc	= &nfs_procedures[NFSPROC_GETATTR],
+		.rpc_argp	= fhandle,
+		.rpc_resp	= fattr,
+	};
+	int status;
+
+	dprintk("%s: call getattr\n", __func__);
+	nfs_fattr_init(fattr);
+	status = rpc_call_sync(server->client, &msg, 0);
+	/* Retry with default authentication if different */
+	if (status && server->nfs_client->cl_rpcclient != server->client)
+		status = rpc_call_sync(server->nfs_client->cl_rpcclient, &msg, 0);
+	dprintk("%s: reply getattr: %d\n", __func__, status);
+	if (status)
+		return status;
+	dprintk("%s: call statfs\n", __func__);
+	msg.rpc_proc = &nfs_procedures[NFSPROC_STATFS];
+	msg.rpc_resp = &fsinfo;
+	status = rpc_call_sync(server->client, &msg, 0);
+	/* Retry with default authentication if different */
+	if (status && server->nfs_client->cl_rpcclient != server->client)
+		status = rpc_call_sync(server->nfs_client->cl_rpcclient, &msg, 0);
+	dprintk("%s: reply statfs: %d\n", __func__, status);
+	if (status)
+		return status;
+	info->rtmax  = NFS_MAXDATA;
+	info->rtpref = fsinfo.tsize;
+	info->rtmult = fsinfo.bsize;
+	info->wtmax  = NFS_MAXDATA;
+	info->wtpref = fsinfo.tsize;
+	info->wtmult = fsinfo.bsize;
+	info->dtpref = fsinfo.tsize;
+	info->maxfilesize = 0x7FFFFFFF;
+	info->lease_time = 0;
+	return 0;
+}
+
+/*
+ * One function for each procedure in the NFS protocol.
+ */
+static int
+nfs_proc_getattr(struct nfs_server *server, struct nfs_fh *fhandle,
+		struct nfs_fattr *fattr, struct nfs4_label *label,
+		struct inode *inode)
+{
+	struct rpc_message msg = {
+		.rpc_proc	= &nfs_procedures[NFSPROC_GETATTR],
+		.rpc_argp	= fhandle,
+		.rpc_resp	= fattr,
+	};
+	int	status;
+	unsigned short task_flags = 0;
+
+	/* Is this is an attribute revalidation, subject to softreval? */
+	if (inode && (server->flags & NFS_MOUNT_SOFTREVAL))
+		task_flags |= RPC_TASK_TIMEOUT;
+
+	dprintk("NFS call  getattr\n");
+	nfs_fattr_init(fattr);
+	status = rpc_call_sync(server->client, &msg, task_flags);
+	dprintk("NFS reply getattr: %d\n", status);
+	return status;
+}
+
+static int
+nfs_proc_setattr(struct dentry *dentry, struct nfs_fattr *fattr,
+		 struct iattr *sattr)
+{
+	struct inode *inode = d_inode(dentry);
+	struct nfs_sattrargs	arg = { 
+		.fh	= NFS_FH(inode),
+		.sattr	= sattr
+	};
+	struct rpc_message msg = {
+		.rpc_proc	= &nfs_procedures[NFSPROC_SETATTR],
+		.rpc_argp	= &arg,
+		.rpc_resp	= fattr,
+	};
+	int	status;
+
+	/* Mask out the non-modebit related stuff from attr->ia_mode */
+	sattr->ia_mode &= S_IALLUGO;
+
+	dprintk("NFS call  setattr\n");
+	if (sattr->ia_valid & ATTR_FILE)
+		msg.rpc_cred = nfs_file_cred(sattr->ia_file);
+	nfs_fattr_init(fattr);
+	status = rpc_call_sync(NFS_CLIENT(inode), &msg, 0);
+	if (status == 0)
+		nfs_setattr_update_inode(inode, sattr, fattr);
+	dprintk("NFS reply setattr: %d\n", status);
+	return status;
+}
+
+static int
+nfs_proc_lookup(struct inode *dir, struct dentry *dentry,
+		struct nfs_fh *fhandle, struct nfs_fattr *fattr,
+		struct nfs4_label *label)
+{
+	struct nfs_diropargs	arg = {
+		.fh		= NFS_FH(dir),
+		.name		= dentry->d_name.name,
+		.len		= dentry->d_name.len
+	};
+	struct nfs_diropok	res = {
+		.fh		= fhandle,
+		.fattr		= fattr
+	};
+	struct rpc_message msg = {
+		.rpc_proc	= &nfs_procedures[NFSPROC_LOOKUP],
+		.rpc_argp	= &arg,
+		.rpc_resp	= &res,
+	};
+	int			status;
+	unsigned short task_flags = 0;
+
+	/* Is this is an attribute revalidation, subject to softreval? */
+	if (nfs_lookup_is_soft_revalidate(dentry))
+		task_flags |= RPC_TASK_TIMEOUT;
+
+	dprintk("NFS call  lookup %pd2\n", dentry);
+	nfs_fattr_init(fattr);
+	status = rpc_call_sync(NFS_CLIENT(dir), &msg, task_flags);
+	dprintk("NFS reply lookup: %d\n", status);
+	return status;
+}
+
+static int nfs_proc_readlink(struct inode *inode, struct page *page,
+		unsigned int pgbase, unsigned int pglen)
+{
+	struct nfs_readlinkargs	args = {
+		.fh		= NFS_FH(inode),
+		.pgbase		= pgbase,
+		.pglen		= pglen,
+		.pages		= &page
+	};
+	struct rpc_message msg = {
+		.rpc_proc	= &nfs_procedures[NFSPROC_READLINK],
+		.rpc_argp	= &args,
+	};
+	int			status;
+
+	dprintk("NFS call  readlink\n");
+	status = rpc_call_sync(NFS_CLIENT(inode), &msg, 0);
+	dprintk("NFS reply readlink: %d\n", status);
+	return status;
+}
+
+struct nfs_createdata {
+	struct nfs_createargs arg;
+	struct nfs_diropok res;
+	struct nfs_fh fhandle;
+	struct nfs_fattr fattr;
+};
+
+static struct nfs_createdata *nfs_alloc_createdata(struct inode *dir,
+		struct dentry *dentry, struct iattr *sattr)
+{
+	struct nfs_createdata *data;
+
+	data = kmalloc(sizeof(*data), GFP_KERNEL);
+
+	if (data != NULL) {
+		data->arg.fh = NFS_FH(dir);
+		data->arg.name = dentry->d_name.name;
+		data->arg.len = dentry->d_name.len;
+		data->arg.sattr = sattr;
+		nfs_fattr_init(&data->fattr);
+		data->fhandle.size = 0;
+		data->res.fh = &data->fhandle;
+		data->res.fattr = &data->fattr;
+	}
+	return data;
+};
+
+static void nfs_free_createdata(const struct nfs_createdata *data)
+{
+	kfree(data);
+}
+
+static int
+nfs_proc_create(struct inode *dir, struct dentry *dentry, struct iattr *sattr,
+		int flags)
+{
+	struct nfs_createdata *data;
+	struct rpc_message msg = {
+		.rpc_proc	= &nfs_procedures[NFSPROC_CREATE],
+	};
+	int status = -ENOMEM;
+
+	dprintk("NFS call  create %pd\n", dentry);
+	data = nfs_alloc_createdata(dir, dentry, sattr);
+	if (data == NULL)
+		goto out;
+	msg.rpc_argp = &data->arg;
+	msg.rpc_resp = &data->res;
+	status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
+	nfs_mark_for_revalidate(dir);
+	if (status == 0)
+		status = nfs_instantiate(dentry, data->res.fh, data->res.fattr, NULL);
+	nfs_free_createdata(data);
+out:
+	dprintk("NFS reply create: %d\n", status);
+	return status;
+}
+
+/*
+ * In NFSv2, mknod is grafted onto the create call.
+ */
+static int
+nfs_proc_mknod(struct inode *dir, struct dentry *dentry, struct iattr *sattr,
+	       dev_t rdev)
+{
+	struct nfs_createdata *data;
+	struct rpc_message msg = {
+		.rpc_proc	= &nfs_procedures[NFSPROC_CREATE],
+	};
+	umode_t mode;
+	int status = -ENOMEM;
+
+	dprintk("NFS call  mknod %pd\n", dentry);
+
+	mode = sattr->ia_mode;
+	if (S_ISFIFO(mode)) {
+		sattr->ia_mode = (mode & ~S_IFMT) | S_IFCHR;
+		sattr->ia_valid &= ~ATTR_SIZE;
+	} else if (S_ISCHR(mode) || S_ISBLK(mode)) {
+		sattr->ia_valid |= ATTR_SIZE;
+		sattr->ia_size = new_encode_dev(rdev);/* get out your barf bag */
+	}
+
+	data = nfs_alloc_createdata(dir, dentry, sattr);
+	if (data == NULL)
+		goto out;
+	msg.rpc_argp = &data->arg;
+	msg.rpc_resp = &data->res;
+
+	status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
+	nfs_mark_for_revalidate(dir);
+
+	if (status == -EINVAL && S_ISFIFO(mode)) {
+		sattr->ia_mode = mode;
+		nfs_fattr_init(data->res.fattr);
+		status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
+	}
+	if (status == 0)
+		status = nfs_instantiate(dentry, data->res.fh, data->res.fattr, NULL);
+	nfs_free_createdata(data);
+out:
+	dprintk("NFS reply mknod: %d\n", status);
+	return status;
+}
+  
+static int
+nfs_proc_remove(struct inode *dir, struct dentry *dentry)
+{
+	struct nfs_removeargs arg = {
+		.fh = NFS_FH(dir),
+		.name = dentry->d_name,
+	};
+	struct rpc_message msg = { 
+		.rpc_proc = &nfs_procedures[NFSPROC_REMOVE],
+		.rpc_argp = &arg,
+	};
+	int			status;
+
+	dprintk("NFS call  remove %pd2\n",dentry);
+	status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
+	nfs_mark_for_revalidate(dir);
+
+	dprintk("NFS reply remove: %d\n", status);
+	return status;
+}
+
+static void
+nfs_proc_unlink_setup(struct rpc_message *msg,
+		struct dentry *dentry,
+		struct inode *inode)
+{
+	msg->rpc_proc = &nfs_procedures[NFSPROC_REMOVE];
+}
+
+static void nfs_proc_unlink_rpc_prepare(struct rpc_task *task, struct nfs_unlinkdata *data)
+{
+	rpc_call_start(task);
+}
+
+static int nfs_proc_unlink_done(struct rpc_task *task, struct inode *dir)
+{
+	nfs_mark_for_revalidate(dir);
+	return 1;
+}
+
+static void
+nfs_proc_rename_setup(struct rpc_message *msg,
+		struct dentry *old_dentry,
+		struct dentry *new_dentry)
+{
+	msg->rpc_proc = &nfs_procedures[NFSPROC_RENAME];
+}
+
+static void nfs_proc_rename_rpc_prepare(struct rpc_task *task, struct nfs_renamedata *data)
+{
+	rpc_call_start(task);
+}
+
+static int
+nfs_proc_rename_done(struct rpc_task *task, struct inode *old_dir,
+		     struct inode *new_dir)
+{
+	nfs_mark_for_revalidate(old_dir);
+	nfs_mark_for_revalidate(new_dir);
+	return 1;
+}
+
+static int
+nfs_proc_link(struct inode *inode, struct inode *dir, const struct qstr *name)
+{
+	struct nfs_linkargs	arg = {
+		.fromfh		= NFS_FH(inode),
+		.tofh		= NFS_FH(dir),
+		.toname		= name->name,
+		.tolen		= name->len
+	};
+	struct rpc_message msg = {
+		.rpc_proc	= &nfs_procedures[NFSPROC_LINK],
+		.rpc_argp	= &arg,
+	};
+	int			status;
+
+	dprintk("NFS call  link %s\n", name->name);
+	status = rpc_call_sync(NFS_CLIENT(inode), &msg, 0);
+	nfs_mark_for_revalidate(inode);
+	nfs_mark_for_revalidate(dir);
+	dprintk("NFS reply link: %d\n", status);
+	return status;
+}
+
+static int
+nfs_proc_symlink(struct inode *dir, struct dentry *dentry, struct page *page,
+		 unsigned int len, struct iattr *sattr)
+{
+	struct nfs_fh *fh;
+	struct nfs_fattr *fattr;
+	struct nfs_symlinkargs	arg = {
+		.fromfh		= NFS_FH(dir),
+		.fromname	= dentry->d_name.name,
+		.fromlen	= dentry->d_name.len,
+		.pages		= &page,
+		.pathlen	= len,
+		.sattr		= sattr
+	};
+	struct rpc_message msg = {
+		.rpc_proc	= &nfs_procedures[NFSPROC_SYMLINK],
+		.rpc_argp	= &arg,
+	};
+	int status = -ENAMETOOLONG;
+
+	dprintk("NFS call  symlink %pd\n", dentry);
+
+	if (len > NFS2_MAXPATHLEN)
+		goto out;
+
+	fh = nfs_alloc_fhandle();
+	fattr = nfs_alloc_fattr();
+	status = -ENOMEM;
+	if (fh == NULL || fattr == NULL)
+		goto out_free;
+
+	status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
+	nfs_mark_for_revalidate(dir);
+
+	/*
+	 * V2 SYMLINK requests don't return any attributes.  Setting the
+	 * filehandle size to zero indicates to nfs_instantiate that it
+	 * should fill in the data with a LOOKUP call on the wire.
+	 */
+	if (status == 0)
+		status = nfs_instantiate(dentry, fh, fattr, NULL);
+
+out_free:
+	nfs_free_fattr(fattr);
+	nfs_free_fhandle(fh);
+out:
+	dprintk("NFS reply symlink: %d\n", status);
+	return status;
+}
+
+static int
+nfs_proc_mkdir(struct inode *dir, struct dentry *dentry, struct iattr *sattr)
+{
+	struct nfs_createdata *data;
+	struct rpc_message msg = {
+		.rpc_proc	= &nfs_procedures[NFSPROC_MKDIR],
+	};
+	int status = -ENOMEM;
+
+	dprintk("NFS call  mkdir %pd\n", dentry);
+	data = nfs_alloc_createdata(dir, dentry, sattr);
+	if (data == NULL)
+		goto out;
+	msg.rpc_argp = &data->arg;
+	msg.rpc_resp = &data->res;
+
+	status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
+	nfs_mark_for_revalidate(dir);
+	if (status == 0)
+		status = nfs_instantiate(dentry, data->res.fh, data->res.fattr, NULL);
+	nfs_free_createdata(data);
+out:
+	dprintk("NFS reply mkdir: %d\n", status);
+	return status;
+}
+
+static int
+nfs_proc_rmdir(struct inode *dir, const struct qstr *name)
+{
+	struct nfs_diropargs	arg = {
+		.fh		= NFS_FH(dir),
+		.name		= name->name,
+		.len		= name->len
+	};
+	struct rpc_message msg = {
+		.rpc_proc	= &nfs_procedures[NFSPROC_RMDIR],
+		.rpc_argp	= &arg,
+	};
+	int			status;
+
+	dprintk("NFS call  rmdir %s\n", name->name);
+	status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
+	nfs_mark_for_revalidate(dir);
+	dprintk("NFS reply rmdir: %d\n", status);
+	return status;
+}
+
+/*
+ * The READDIR implementation is somewhat hackish - we pass a temporary
+ * buffer to the encode function, which installs it in the receive
+ * the receive iovec. The decode function just parses the reply to make
+ * sure it is syntactically correct; the entries itself are decoded
+ * from nfs_readdir by calling the decode_entry function directly.
+ */
+static int
+nfs_proc_readdir(struct dentry *dentry, const struct cred *cred,
+		 u64 cookie, struct page **pages, unsigned int count, bool plus)
+{
+	struct inode		*dir = d_inode(dentry);
+	struct nfs_readdirargs	arg = {
+		.fh		= NFS_FH(dir),
+		.cookie		= cookie,
+		.count		= count,
+		.pages		= pages,
+	};
+	struct rpc_message	msg = {
+		.rpc_proc	= &nfs_procedures[NFSPROC_READDIR],
+		.rpc_argp	= &arg,
+		.rpc_cred	= cred,
+	};
+	int			status;
+
+	dprintk("NFS call  readdir %d\n", (unsigned int)cookie);
+	status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
+
+	nfs_invalidate_atime(dir);
+
+	dprintk("NFS reply readdir: %d\n", status);
+	return status;
+}
+
+static int
+nfs_proc_statfs(struct nfs_server *server, struct nfs_fh *fhandle,
+			struct nfs_fsstat *stat)
+{
+	struct nfs2_fsstat fsinfo;
+	struct rpc_message msg = {
+		.rpc_proc	= &nfs_procedures[NFSPROC_STATFS],
+		.rpc_argp	= fhandle,
+		.rpc_resp	= &fsinfo,
+	};
+	int	status;
+
+	dprintk("NFS call  statfs\n");
+	nfs_fattr_init(stat->fattr);
+	status = rpc_call_sync(server->client, &msg, 0);
+	dprintk("NFS reply statfs: %d\n", status);
+	if (status)
+		goto out;
+	stat->tbytes = (u64)fsinfo.blocks * fsinfo.bsize;
+	stat->fbytes = (u64)fsinfo.bfree  * fsinfo.bsize;
+	stat->abytes = (u64)fsinfo.bavail * fsinfo.bsize;
+	stat->tfiles = 0;
+	stat->ffiles = 0;
+	stat->afiles = 0;
+out:
+	return status;
+}
+
+static int
+nfs_proc_fsinfo(struct nfs_server *server, struct nfs_fh *fhandle,
+			struct nfs_fsinfo *info)
+{
+	struct nfs2_fsstat fsinfo;
+	struct rpc_message msg = {
+		.rpc_proc	= &nfs_procedures[NFSPROC_STATFS],
+		.rpc_argp	= fhandle,
+		.rpc_resp	= &fsinfo,
+	};
+	int	status;
+
+	dprintk("NFS call  fsinfo\n");
+	nfs_fattr_init(info->fattr);
+	status = rpc_call_sync(server->client, &msg, 0);
+	dprintk("NFS reply fsinfo: %d\n", status);
+	if (status)
+		goto out;
+	info->rtmax  = NFS_MAXDATA;
+	info->rtpref = fsinfo.tsize;
+	info->rtmult = fsinfo.bsize;
+	info->wtmax  = NFS_MAXDATA;
+	info->wtpref = fsinfo.tsize;
+	info->wtmult = fsinfo.bsize;
+	info->dtpref = fsinfo.tsize;
+	info->maxfilesize = 0x7FFFFFFF;
+	info->lease_time = 0;
+out:
+	return status;
+}
+
+static int
+nfs_proc_pathconf(struct nfs_server *server, struct nfs_fh *fhandle,
+		  struct nfs_pathconf *info)
+{
+	info->max_link = 0;
+	info->max_namelen = NFS2_MAXNAMLEN;
+	return 0;
+}
+
+static int nfs_read_done(struct rpc_task *task, struct nfs_pgio_header *hdr)
+{
+	struct inode *inode = hdr->inode;
+
+	nfs_invalidate_atime(inode);
+	if (task->tk_status >= 0) {
+		nfs_refresh_inode(inode, hdr->res.fattr);
+		/* Emulate the eof flag, which isn't normally needed in NFSv2
+		 * as it is guaranteed to always return the file attributes
+		 */
+		if ((hdr->res.count == 0 && hdr->args.count > 0) ||
+		    hdr->args.offset + hdr->res.count >= hdr->res.fattr->size)
+			hdr->res.eof = 1;
+	}
+	return 0;
+}
+
+static void nfs_proc_read_setup(struct nfs_pgio_header *hdr,
+				struct rpc_message *msg)
+{
+	msg->rpc_proc = &nfs_procedures[NFSPROC_READ];
+}
+
+static int nfs_proc_pgio_rpc_prepare(struct rpc_task *task,
+				     struct nfs_pgio_header *hdr)
+{
+	rpc_call_start(task);
+	return 0;
+}
+
+static int nfs_write_done(struct rpc_task *task, struct nfs_pgio_header *hdr)
+{
+	if (task->tk_status >= 0) {
+		hdr->res.count = hdr->args.count;
+		nfs_writeback_update_inode(hdr);
+	}
+	return 0;
+}
+
+static void nfs_proc_write_setup(struct nfs_pgio_header *hdr,
+				 struct rpc_message *msg,
+				 struct rpc_clnt **clnt)
+{
+	/* Note: NFSv2 ignores @stable and always uses NFS_FILE_SYNC */
+	hdr->args.stable = NFS_FILE_SYNC;
+	msg->rpc_proc = &nfs_procedures[NFSPROC_WRITE];
+}
+
+static void nfs_proc_commit_rpc_prepare(struct rpc_task *task, struct nfs_commit_data *data)
+{
+	BUG();
+}
+
+static void
+nfs_proc_commit_setup(struct nfs_commit_data *data, struct rpc_message *msg,
+			struct rpc_clnt **clnt)
+{
+	BUG();
+}
+
+static int
+nfs_proc_lock(struct file *filp, int cmd, struct file_lock *fl)
+{
+	struct inode *inode = file_inode(filp);
+
+	return nlmclnt_proc(NFS_SERVER(inode)->nlm_host, cmd, fl, NULL);
+}
+
+/* Helper functions for NFS lock bounds checking */
+#define NFS_LOCK32_OFFSET_MAX ((__s32)0x7fffffffUL)
+static int nfs_lock_check_bounds(const struct file_lock *fl)
+{
+	__s32 start, end;
+
+	start = (__s32)fl->fl_start;
+	if ((loff_t)start != fl->fl_start)
+		goto out_einval;
+
+	if (fl->fl_end != OFFSET_MAX) {
+		end = (__s32)fl->fl_end;
+		if ((loff_t)end != fl->fl_end)
+			goto out_einval;
+	} else
+		end = NFS_LOCK32_OFFSET_MAX;
+
+	if (start < 0 || start > end)
+		goto out_einval;
+	return 0;
+out_einval:
+	return -EINVAL;
+}
+
+static int nfs_have_delegation(struct inode *inode, fmode_t flags)
+{
+	return 0;
+}
+
+static const struct inode_operations nfs_dir_inode_operations = {
+	.create		= nfs_create,
+	.lookup		= nfs_lookup,
+	.link		= nfs_link,
+	.unlink		= nfs_unlink,
+	.symlink	= nfs_symlink,
+	.mkdir		= nfs_mkdir,
+	.rmdir		= nfs_rmdir,
+	.mknod		= nfs_mknod,
+	.rename		= nfs_rename,
+	.permission	= nfs_permission,
+	.getattr	= nfs_getattr,
+	.setattr	= nfs_setattr,
+};
+
+static const struct inode_operations nfs_file_inode_operations = {
+	.permission	= nfs_permission,
+	.getattr	= nfs_getattr,
+	.setattr	= nfs_setattr,
+};
+
+const struct nfs_rpc_ops nfs_v2_clientops = {
+	.version	= 2,		       /* protocol version */
+	.dentry_ops	= &nfs_dentry_operations,
+	.dir_inode_ops	= &nfs_dir_inode_operations,
+	.file_inode_ops	= &nfs_file_inode_operations,
+	.file_ops	= &nfs_file_operations,
+	.getroot	= nfs_proc_get_root,
+	.submount	= nfs_submount,
+	.try_get_tree	= nfs_try_get_tree,
+	.getattr	= nfs_proc_getattr,
+	.setattr	= nfs_proc_setattr,
+	.lookup		= nfs_proc_lookup,
+	.access		= NULL,		       /* access */
+	.readlink	= nfs_proc_readlink,
+	.create		= nfs_proc_create,
+	.remove		= nfs_proc_remove,
+	.unlink_setup	= nfs_proc_unlink_setup,
+	.unlink_rpc_prepare = nfs_proc_unlink_rpc_prepare,
+	.unlink_done	= nfs_proc_unlink_done,
+	.rename_setup	= nfs_proc_rename_setup,
+	.rename_rpc_prepare = nfs_proc_rename_rpc_prepare,
+	.rename_done	= nfs_proc_rename_done,
+	.link		= nfs_proc_link,
+	.symlink	= nfs_proc_symlink,
+	.mkdir		= nfs_proc_mkdir,
+	.rmdir		= nfs_proc_rmdir,
+	.readdir	= nfs_proc_readdir,
+	.mknod		= nfs_proc_mknod,
+	.statfs		= nfs_proc_statfs,
+	.fsinfo		= nfs_proc_fsinfo,
+	.pathconf	= nfs_proc_pathconf,
+	.decode_dirent	= nfs2_decode_dirent,
+	.pgio_rpc_prepare = nfs_proc_pgio_rpc_prepare,
+	.read_setup	= nfs_proc_read_setup,
+	.read_done	= nfs_read_done,
+	.write_setup	= nfs_proc_write_setup,
+	.write_done	= nfs_write_done,
+	.commit_setup	= nfs_proc_commit_setup,
+	.commit_rpc_prepare = nfs_proc_commit_rpc_prepare,
+	.lock		= nfs_proc_lock,
+	.lock_check_bounds = nfs_lock_check_bounds,
+	.close_context	= nfs_close_context,
+	.have_delegation = nfs_have_delegation,
+	.alloc_client	= nfs_alloc_client,
+	.init_client	= nfs_init_client,
+	.free_client	= nfs_free_client,
+	.create_server	= nfs_create_server,
+	.clone_server	= nfs_clone_server,
+};
diff --git a/fs/nfs/read.c b/fs/nfs/read.c
new file mode 100644
index 000000000..eb854f1f8
--- /dev/null
+++ b/fs/nfs/read.c
@@ -0,0 +1,486 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * linux/fs/nfs/read.c
+ *
+ * Block I/O for NFS
+ *
+ * Partial copy of Linus' read cache modifications to fs/nfs/file.c
+ * modified for async RPC by okir@monad.swb.de
+ */
+
+#include <linux/time.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/fcntl.h>
+#include <linux/stat.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/pagemap.h>
+#include <linux/sunrpc/clnt.h>
+#include <linux/nfs_fs.h>
+#include <linux/nfs_page.h>
+#include <linux/module.h>
+
+#include "nfs4_fs.h"
+#include "internal.h"
+#include "iostat.h"
+#include "fscache.h"
+#include "pnfs.h"
+#include "nfstrace.h"
+
+#define NFSDBG_FACILITY		NFSDBG_PAGECACHE
+
+static const struct nfs_pgio_completion_ops nfs_async_read_completion_ops;
+static const struct nfs_rw_ops nfs_rw_read_ops;
+
+static struct kmem_cache *nfs_rdata_cachep;
+
+static struct nfs_pgio_header *nfs_readhdr_alloc(void)
+{
+	struct nfs_pgio_header *p = kmem_cache_zalloc(nfs_rdata_cachep, GFP_KERNEL);
+
+	if (p)
+		p->rw_mode = FMODE_READ;
+	return p;
+}
+
+static void nfs_readhdr_free(struct nfs_pgio_header *rhdr)
+{
+	kmem_cache_free(nfs_rdata_cachep, rhdr);
+}
+
+static
+int nfs_return_empty_page(struct page *page)
+{
+	zero_user(page, 0, PAGE_SIZE);
+	SetPageUptodate(page);
+	unlock_page(page);
+	return 0;
+}
+
+void nfs_pageio_init_read(struct nfs_pageio_descriptor *pgio,
+			      struct inode *inode, bool force_mds,
+			      const struct nfs_pgio_completion_ops *compl_ops)
+{
+	struct nfs_server *server = NFS_SERVER(inode);
+	const struct nfs_pageio_ops *pg_ops = &nfs_pgio_rw_ops;
+
+#ifdef CONFIG_NFS_V4_1
+	if (server->pnfs_curr_ld && !force_mds)
+		pg_ops = server->pnfs_curr_ld->pg_read_ops;
+#endif
+	nfs_pageio_init(pgio, inode, pg_ops, compl_ops, &nfs_rw_read_ops,
+			server->rsize, 0);
+}
+EXPORT_SYMBOL_GPL(nfs_pageio_init_read);
+
+void nfs_pageio_reset_read_mds(struct nfs_pageio_descriptor *pgio)
+{
+	struct nfs_pgio_mirror *mirror;
+
+	if (pgio->pg_ops && pgio->pg_ops->pg_cleanup)
+		pgio->pg_ops->pg_cleanup(pgio);
+
+	pgio->pg_ops = &nfs_pgio_rw_ops;
+
+	/* read path should never have more than one mirror */
+	WARN_ON_ONCE(pgio->pg_mirror_count != 1);
+
+	mirror = &pgio->pg_mirrors[0];
+	mirror->pg_bsize = NFS_SERVER(pgio->pg_inode)->rsize;
+}
+EXPORT_SYMBOL_GPL(nfs_pageio_reset_read_mds);
+
+static void nfs_readpage_release(struct nfs_page *req, int error)
+{
+	struct inode *inode = d_inode(nfs_req_openctx(req)->dentry);
+	struct page *page = req->wb_page;
+
+	dprintk("NFS: read done (%s/%llu %d@%lld)\n", inode->i_sb->s_id,
+		(unsigned long long)NFS_FILEID(inode), req->wb_bytes,
+		(long long)req_offset(req));
+
+	if (nfs_error_is_fatal_on_server(error) && error != -ETIMEDOUT)
+		SetPageError(page);
+	if (nfs_page_group_sync_on_bit(req, PG_UNLOCKPAGE)) {
+		struct address_space *mapping = page_file_mapping(page);
+
+		if (PageUptodate(page))
+			nfs_readpage_to_fscache(inode, page, 0);
+		else if (!PageError(page) && !PagePrivate(page))
+			generic_error_remove_page(mapping, page);
+		unlock_page(page);
+	}
+	nfs_release_request(req);
+}
+
+int nfs_readpage_async(struct nfs_open_context *ctx, struct inode *inode,
+		       struct page *page)
+{
+	struct nfs_page	*new;
+	unsigned int len;
+	struct nfs_pageio_descriptor pgio;
+	struct nfs_pgio_mirror *pgm;
+
+	len = nfs_page_length(page);
+	if (len == 0)
+		return nfs_return_empty_page(page);
+	new = nfs_create_request(ctx, page, 0, len);
+	if (IS_ERR(new)) {
+		unlock_page(page);
+		return PTR_ERR(new);
+	}
+	if (len < PAGE_SIZE)
+		zero_user_segment(page, len, PAGE_SIZE);
+
+	nfs_pageio_init_read(&pgio, inode, false,
+			     &nfs_async_read_completion_ops);
+	if (!nfs_pageio_add_request(&pgio, new)) {
+		nfs_list_remove_request(new);
+		nfs_readpage_release(new, pgio.pg_error);
+	}
+	nfs_pageio_complete(&pgio);
+
+	/* It doesn't make sense to do mirrored reads! */
+	WARN_ON_ONCE(pgio.pg_mirror_count != 1);
+
+	pgm = &pgio.pg_mirrors[0];
+	NFS_I(inode)->read_io += pgm->pg_bytes_written;
+
+	return pgio.pg_error < 0 ? pgio.pg_error : 0;
+}
+
+static void nfs_page_group_set_uptodate(struct nfs_page *req)
+{
+	if (nfs_page_group_sync_on_bit(req, PG_UPTODATE))
+		SetPageUptodate(req->wb_page);
+}
+
+static void nfs_read_completion(struct nfs_pgio_header *hdr)
+{
+	unsigned long bytes = 0;
+	int error;
+
+	if (test_bit(NFS_IOHDR_REDO, &hdr->flags))
+		goto out;
+	while (!list_empty(&hdr->pages)) {
+		struct nfs_page *req = nfs_list_entry(hdr->pages.next);
+		struct page *page = req->wb_page;
+		unsigned long start = req->wb_pgbase;
+		unsigned long end = req->wb_pgbase + req->wb_bytes;
+
+		if (test_bit(NFS_IOHDR_EOF, &hdr->flags)) {
+			/* note: regions of the page not covered by a
+			 * request are zeroed in nfs_readpage_async /
+			 * readpage_async_filler */
+			if (bytes > hdr->good_bytes) {
+				/* nothing in this request was good, so zero
+				 * the full extent of the request */
+				zero_user_segment(page, start, end);
+
+			} else if (hdr->good_bytes - bytes < req->wb_bytes) {
+				/* part of this request has good bytes, but
+				 * not all. zero the bad bytes */
+				start += hdr->good_bytes - bytes;
+				WARN_ON(start < req->wb_pgbase);
+				zero_user_segment(page, start, end);
+			}
+		}
+		error = 0;
+		bytes += req->wb_bytes;
+		if (test_bit(NFS_IOHDR_ERROR, &hdr->flags)) {
+			if (bytes <= hdr->good_bytes)
+				nfs_page_group_set_uptodate(req);
+			else {
+				error = hdr->error;
+				xchg(&nfs_req_openctx(req)->error, error);
+			}
+		} else
+			nfs_page_group_set_uptodate(req);
+		nfs_list_remove_request(req);
+		nfs_readpage_release(req, error);
+	}
+out:
+	hdr->release(hdr);
+}
+
+static void nfs_initiate_read(struct nfs_pgio_header *hdr,
+			      struct rpc_message *msg,
+			      const struct nfs_rpc_ops *rpc_ops,
+			      struct rpc_task_setup *task_setup_data, int how)
+{
+	struct inode *inode = hdr->inode;
+	int swap_flags = IS_SWAPFILE(inode) ? NFS_RPC_SWAPFLAGS : 0;
+
+	task_setup_data->flags |= swap_flags;
+	rpc_ops->read_setup(hdr, msg);
+	trace_nfs_initiate_read(hdr);
+}
+
+static void
+nfs_async_read_error(struct list_head *head, int error)
+{
+	struct nfs_page	*req;
+
+	while (!list_empty(head)) {
+		req = nfs_list_entry(head->next);
+		nfs_list_remove_request(req);
+		nfs_readpage_release(req, error);
+	}
+}
+
+static const struct nfs_pgio_completion_ops nfs_async_read_completion_ops = {
+	.error_cleanup = nfs_async_read_error,
+	.completion = nfs_read_completion,
+};
+
+/*
+ * This is the callback from RPC telling us whether a reply was
+ * received or some error occurred (timeout or socket shutdown).
+ */
+static int nfs_readpage_done(struct rpc_task *task,
+			     struct nfs_pgio_header *hdr,
+			     struct inode *inode)
+{
+	int status = NFS_PROTO(inode)->read_done(task, hdr);
+	if (status != 0)
+		return status;
+
+	nfs_add_stats(inode, NFSIOS_SERVERREADBYTES, hdr->res.count);
+	trace_nfs_readpage_done(task, hdr);
+
+	if (task->tk_status == -ESTALE) {
+		nfs_set_inode_stale(inode);
+		nfs_mark_for_revalidate(inode);
+	}
+	return 0;
+}
+
+static void nfs_readpage_retry(struct rpc_task *task,
+			       struct nfs_pgio_header *hdr)
+{
+	struct nfs_pgio_args *argp = &hdr->args;
+	struct nfs_pgio_res  *resp = &hdr->res;
+
+	/* This is a short read! */
+	nfs_inc_stats(hdr->inode, NFSIOS_SHORTREAD);
+	trace_nfs_readpage_short(task, hdr);
+
+	/* Has the server at least made some progress? */
+	if (resp->count == 0) {
+		nfs_set_pgio_error(hdr, -EIO, argp->offset);
+		return;
+	}
+
+	/* For non rpc-based layout drivers, retry-through-MDS */
+	if (!task->tk_ops) {
+		hdr->pnfs_error = -EAGAIN;
+		return;
+	}
+
+	/* Yes, so retry the read at the end of the hdr */
+	hdr->mds_offset += resp->count;
+	argp->offset += resp->count;
+	argp->pgbase += resp->count;
+	argp->count -= resp->count;
+	resp->count = 0;
+	resp->eof = 0;
+	rpc_restart_call_prepare(task);
+}
+
+static void nfs_readpage_result(struct rpc_task *task,
+				struct nfs_pgio_header *hdr)
+{
+	if (hdr->res.eof) {
+		loff_t pos = hdr->args.offset + hdr->res.count;
+		unsigned int new = pos - hdr->io_start;
+
+		if (hdr->good_bytes > new) {
+			hdr->good_bytes = new;
+			set_bit(NFS_IOHDR_EOF, &hdr->flags);
+			clear_bit(NFS_IOHDR_ERROR, &hdr->flags);
+		}
+	} else if (hdr->res.count < hdr->args.count)
+		nfs_readpage_retry(task, hdr);
+}
+
+/*
+ * Read a page over NFS.
+ * We read the page synchronously in the following case:
+ *  -	The error flag is set for this page. This happens only when a
+ *	previous async read operation failed.
+ */
+int nfs_readpage(struct file *file, struct page *page)
+{
+	struct nfs_open_context *ctx;
+	struct inode *inode = page_file_mapping(page)->host;
+	int		error;
+
+	dprintk("NFS: nfs_readpage (%p %ld@%lu)\n",
+		page, PAGE_SIZE, page_index(page));
+	nfs_inc_stats(inode, NFSIOS_VFSREADPAGE);
+	nfs_add_stats(inode, NFSIOS_READPAGES, 1);
+
+	/*
+	 * Try to flush any pending writes to the file..
+	 *
+	 * NOTE! Because we own the page lock, there cannot
+	 * be any new pending writes generated at this point
+	 * for this page (other pages can be written to).
+	 */
+	error = nfs_wb_page(inode, page);
+	if (error)
+		goto out_unlock;
+	if (PageUptodate(page))
+		goto out_unlock;
+
+	error = -ESTALE;
+	if (NFS_STALE(inode))
+		goto out_unlock;
+
+	if (file == NULL) {
+		error = -EBADF;
+		ctx = nfs_find_open_context(inode, NULL, FMODE_READ);
+		if (ctx == NULL)
+			goto out_unlock;
+	} else
+		ctx = get_nfs_open_context(nfs_file_open_context(file));
+
+	if (!IS_SYNC(inode)) {
+		error = nfs_readpage_from_fscache(ctx, inode, page);
+		if (error == 0)
+			goto out;
+	}
+
+	xchg(&ctx->error, 0);
+	error = nfs_readpage_async(ctx, inode, page);
+	if (!error) {
+		error = wait_on_page_locked_killable(page);
+		if (!PageUptodate(page) && !error)
+			error = xchg(&ctx->error, 0);
+	}
+out:
+	put_nfs_open_context(ctx);
+	return error;
+out_unlock:
+	unlock_page(page);
+	return error;
+}
+
+struct nfs_readdesc {
+	struct nfs_pageio_descriptor *pgio;
+	struct nfs_open_context *ctx;
+};
+
+static int
+readpage_async_filler(void *data, struct page *page)
+{
+	struct nfs_readdesc *desc = (struct nfs_readdesc *)data;
+	struct nfs_page *new;
+	unsigned int len;
+	int error;
+
+	len = nfs_page_length(page);
+	if (len == 0)
+		return nfs_return_empty_page(page);
+
+	new = nfs_create_request(desc->ctx, page, 0, len);
+	if (IS_ERR(new))
+		goto out_error;
+
+	if (len < PAGE_SIZE)
+		zero_user_segment(page, len, PAGE_SIZE);
+	if (!nfs_pageio_add_request(desc->pgio, new)) {
+		nfs_list_remove_request(new);
+		error = desc->pgio->pg_error;
+		nfs_readpage_release(new, error);
+		goto out;
+	}
+	return 0;
+out_error:
+	error = PTR_ERR(new);
+	unlock_page(page);
+out:
+	return error;
+}
+
+int nfs_readpages(struct file *filp, struct address_space *mapping,
+		struct list_head *pages, unsigned nr_pages)
+{
+	struct nfs_pageio_descriptor pgio;
+	struct nfs_pgio_mirror *pgm;
+	struct nfs_readdesc desc = {
+		.pgio = &pgio,
+	};
+	struct inode *inode = mapping->host;
+	unsigned long npages;
+	int ret = -ESTALE;
+
+	dprintk("NFS: nfs_readpages (%s/%Lu %d)\n",
+			inode->i_sb->s_id,
+			(unsigned long long)NFS_FILEID(inode),
+			nr_pages);
+	nfs_inc_stats(inode, NFSIOS_VFSREADPAGES);
+
+	if (NFS_STALE(inode))
+		goto out;
+
+	if (filp == NULL) {
+		desc.ctx = nfs_find_open_context(inode, NULL, FMODE_READ);
+		if (desc.ctx == NULL)
+			return -EBADF;
+	} else
+		desc.ctx = get_nfs_open_context(nfs_file_open_context(filp));
+
+	/* attempt to read as many of the pages as possible from the cache
+	 * - this returns -ENOBUFS immediately if the cookie is negative
+	 */
+	ret = nfs_readpages_from_fscache(desc.ctx, inode, mapping,
+					 pages, &nr_pages);
+	if (ret == 0)
+		goto read_complete; /* all pages were read */
+
+	nfs_pageio_init_read(&pgio, inode, false,
+			     &nfs_async_read_completion_ops);
+
+	ret = read_cache_pages(mapping, pages, readpage_async_filler, &desc);
+	nfs_pageio_complete(&pgio);
+
+	/* It doesn't make sense to do mirrored reads! */
+	WARN_ON_ONCE(pgio.pg_mirror_count != 1);
+
+	pgm = &pgio.pg_mirrors[0];
+	NFS_I(inode)->read_io += pgm->pg_bytes_written;
+	npages = (pgm->pg_bytes_written + PAGE_SIZE - 1) >>
+		 PAGE_SHIFT;
+	nfs_add_stats(inode, NFSIOS_READPAGES, npages);
+read_complete:
+	put_nfs_open_context(desc.ctx);
+out:
+	return ret;
+}
+
+int __init nfs_init_readpagecache(void)
+{
+	nfs_rdata_cachep = kmem_cache_create("nfs_read_data",
+					     sizeof(struct nfs_pgio_header),
+					     0, SLAB_HWCACHE_ALIGN,
+					     NULL);
+	if (nfs_rdata_cachep == NULL)
+		return -ENOMEM;
+
+	return 0;
+}
+
+void nfs_destroy_readpagecache(void)
+{
+	kmem_cache_destroy(nfs_rdata_cachep);
+}
+
+static const struct nfs_rw_ops nfs_rw_read_ops = {
+	.rw_alloc_header	= nfs_readhdr_alloc,
+	.rw_free_header		= nfs_readhdr_free,
+	.rw_done		= nfs_readpage_done,
+	.rw_result		= nfs_readpage_result,
+	.rw_initiate		= nfs_initiate_read,
+};
diff --git a/fs/nfs/super.c b/fs/nfs/super.c
new file mode 100644
index 000000000..b3fcc27b9
--- /dev/null
+++ b/fs/nfs/super.c
@@ -0,0 +1,1401 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  linux/fs/nfs/super.c
+ *
+ *  Copyright (C) 1992  Rick Sladkey
+ *
+ *  nfs superblock handling functions
+ *
+ *  Modularised by Alan Cox <alan@lxorguk.ukuu.org.uk>, while hacking some
+ *  experimental NFS changes. Modularisation taken straight from SYS5 fs.
+ *
+ *  Change to nfs_read_super() to permit NFS mounts to multi-homed hosts.
+ *  J.S.Peatfield@damtp.cam.ac.uk
+ *
+ *  Split from inode.c by David Howells <dhowells@redhat.com>
+ *
+ * - superblocks are indexed on server only - all inodes, dentries, etc. associated with a
+ *   particular server are held in the same superblock
+ * - NFS superblocks can have several effective roots to the dentry tree
+ * - directory type roots are spliced into the tree when a path from one root reaches the root
+ *   of another (see nfs_lookup())
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+
+#include <linux/time.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/string.h>
+#include <linux/stat.h>
+#include <linux/errno.h>
+#include <linux/unistd.h>
+#include <linux/sunrpc/clnt.h>
+#include <linux/sunrpc/addr.h>
+#include <linux/sunrpc/stats.h>
+#include <linux/sunrpc/metrics.h>
+#include <linux/sunrpc/xprtsock.h>
+#include <linux/sunrpc/xprtrdma.h>
+#include <linux/nfs_fs.h>
+#include <linux/nfs_mount.h>
+#include <linux/nfs4_mount.h>
+#include <linux/lockd/bind.h>
+#include <linux/seq_file.h>
+#include <linux/mount.h>
+#include <linux/namei.h>
+#include <linux/vfs.h>
+#include <linux/inet.h>
+#include <linux/in6.h>
+#include <linux/slab.h>
+#include <net/ipv6.h>
+#include <linux/netdevice.h>
+#include <linux/nfs_xdr.h>
+#include <linux/magic.h>
+#include <linux/parser.h>
+#include <linux/nsproxy.h>
+#include <linux/rcupdate.h>
+
+#include <linux/uaccess.h>
+#include <linux/nfs_ssc.h>
+
+#include "nfs4_fs.h"
+#include "callback.h"
+#include "delegation.h"
+#include "iostat.h"
+#include "internal.h"
+#include "fscache.h"
+#include "nfs4session.h"
+#include "pnfs.h"
+#include "nfs.h"
+
+#define NFSDBG_FACILITY		NFSDBG_VFS
+
+const struct super_operations nfs_sops = {
+	.alloc_inode	= nfs_alloc_inode,
+	.free_inode	= nfs_free_inode,
+	.write_inode	= nfs_write_inode,
+	.drop_inode	= nfs_drop_inode,
+	.statfs		= nfs_statfs,
+	.evict_inode	= nfs_evict_inode,
+	.umount_begin	= nfs_umount_begin,
+	.show_options	= nfs_show_options,
+	.show_devname	= nfs_show_devname,
+	.show_path	= nfs_show_path,
+	.show_stats	= nfs_show_stats,
+};
+EXPORT_SYMBOL_GPL(nfs_sops);
+
+static const struct nfs_ssc_client_ops nfs_ssc_clnt_ops_tbl = {
+	.sco_sb_deactive = nfs_sb_deactive,
+};
+
+#if IS_ENABLED(CONFIG_NFS_V4)
+static int __init register_nfs4_fs(void)
+{
+	return register_filesystem(&nfs4_fs_type);
+}
+
+static void unregister_nfs4_fs(void)
+{
+	unregister_filesystem(&nfs4_fs_type);
+}
+#else
+static int __init register_nfs4_fs(void)
+{
+	return 0;
+}
+
+static void unregister_nfs4_fs(void)
+{
+}
+#endif
+
+static void nfs_ssc_register_ops(void)
+{
+	nfs_ssc_register(&nfs_ssc_clnt_ops_tbl);
+}
+
+static void nfs_ssc_unregister_ops(void)
+{
+	nfs_ssc_unregister(&nfs_ssc_clnt_ops_tbl);
+}
+
+static struct shrinker acl_shrinker = {
+	.count_objects	= nfs_access_cache_count,
+	.scan_objects	= nfs_access_cache_scan,
+	.seeks		= DEFAULT_SEEKS,
+};
+
+/*
+ * Register the NFS filesystems
+ */
+int __init register_nfs_fs(void)
+{
+	int ret;
+
+        ret = register_filesystem(&nfs_fs_type);
+	if (ret < 0)
+		goto error_0;
+
+	ret = register_nfs4_fs();
+	if (ret < 0)
+		goto error_1;
+
+	ret = nfs_register_sysctl();
+	if (ret < 0)
+		goto error_2;
+	ret = register_shrinker(&acl_shrinker);
+	if (ret < 0)
+		goto error_3;
+	nfs_ssc_register_ops();
+	return 0;
+error_3:
+	nfs_unregister_sysctl();
+error_2:
+	unregister_nfs4_fs();
+error_1:
+	unregister_filesystem(&nfs_fs_type);
+error_0:
+	return ret;
+}
+
+/*
+ * Unregister the NFS filesystems
+ */
+void __exit unregister_nfs_fs(void)
+{
+	unregister_shrinker(&acl_shrinker);
+	nfs_unregister_sysctl();
+	unregister_nfs4_fs();
+	nfs_ssc_unregister_ops();
+	unregister_filesystem(&nfs_fs_type);
+}
+
+bool nfs_sb_active(struct super_block *sb)
+{
+	struct nfs_server *server = NFS_SB(sb);
+
+	if (!atomic_inc_not_zero(&sb->s_active))
+		return false;
+	if (atomic_inc_return(&server->active) != 1)
+		atomic_dec(&sb->s_active);
+	return true;
+}
+EXPORT_SYMBOL_GPL(nfs_sb_active);
+
+void nfs_sb_deactive(struct super_block *sb)
+{
+	struct nfs_server *server = NFS_SB(sb);
+
+	if (atomic_dec_and_test(&server->active))
+		deactivate_super(sb);
+}
+EXPORT_SYMBOL_GPL(nfs_sb_deactive);
+
+static int __nfs_list_for_each_server(struct list_head *head,
+		int (*fn)(struct nfs_server *, void *),
+		void *data)
+{
+	struct nfs_server *server, *last = NULL;
+	int ret = 0;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(server, head, client_link) {
+		if (!(server->super && nfs_sb_active(server->super)))
+			continue;
+		rcu_read_unlock();
+		if (last)
+			nfs_sb_deactive(last->super);
+		last = server;
+		ret = fn(server, data);
+		if (ret)
+			goto out;
+		rcu_read_lock();
+	}
+	rcu_read_unlock();
+out:
+	if (last)
+		nfs_sb_deactive(last->super);
+	return ret;
+}
+
+int nfs_client_for_each_server(struct nfs_client *clp,
+		int (*fn)(struct nfs_server *, void *),
+		void *data)
+{
+	return __nfs_list_for_each_server(&clp->cl_superblocks, fn, data);
+}
+EXPORT_SYMBOL_GPL(nfs_client_for_each_server);
+
+/*
+ * Deliver file system statistics to userspace
+ */
+int nfs_statfs(struct dentry *dentry, struct kstatfs *buf)
+{
+	struct nfs_server *server = NFS_SB(dentry->d_sb);
+	unsigned char blockbits;
+	unsigned long blockres;
+	struct nfs_fh *fh = NFS_FH(d_inode(dentry));
+	struct nfs_fsstat res;
+	int error = -ENOMEM;
+
+	res.fattr = nfs_alloc_fattr();
+	if (res.fattr == NULL)
+		goto out_err;
+
+	error = server->nfs_client->rpc_ops->statfs(server, fh, &res);
+	if (unlikely(error == -ESTALE)) {
+		struct dentry *pd_dentry;
+
+		pd_dentry = dget_parent(dentry);
+		nfs_zap_caches(d_inode(pd_dentry));
+		dput(pd_dentry);
+	}
+	nfs_free_fattr(res.fattr);
+	if (error < 0)
+		goto out_err;
+
+	buf->f_type = NFS_SUPER_MAGIC;
+
+	/*
+	 * Current versions of glibc do not correctly handle the
+	 * case where f_frsize != f_bsize.  Eventually we want to
+	 * report the value of wtmult in this field.
+	 */
+	buf->f_frsize = dentry->d_sb->s_blocksize;
+
+	/*
+	 * On most *nix systems, f_blocks, f_bfree, and f_bavail
+	 * are reported in units of f_frsize.  Linux hasn't had
+	 * an f_frsize field in its statfs struct until recently,
+	 * thus historically Linux's sys_statfs reports these
+	 * fields in units of f_bsize.
+	 */
+	buf->f_bsize = dentry->d_sb->s_blocksize;
+	blockbits = dentry->d_sb->s_blocksize_bits;
+	blockres = (1 << blockbits) - 1;
+	buf->f_blocks = (res.tbytes + blockres) >> blockbits;
+	buf->f_bfree = (res.fbytes + blockres) >> blockbits;
+	buf->f_bavail = (res.abytes + blockres) >> blockbits;
+
+	buf->f_files = res.tfiles;
+	buf->f_ffree = res.afiles;
+
+	buf->f_namelen = server->namelen;
+
+	return 0;
+
+ out_err:
+	dprintk("%s: statfs error = %d\n", __func__, -error);
+	return error;
+}
+EXPORT_SYMBOL_GPL(nfs_statfs);
+
+/*
+ * Map the security flavour number to a name
+ */
+static const char *nfs_pseudoflavour_to_name(rpc_authflavor_t flavour)
+{
+	static const struct {
+		rpc_authflavor_t flavour;
+		const char *str;
+	} sec_flavours[NFS_AUTH_INFO_MAX_FLAVORS] = {
+		/* update NFS_AUTH_INFO_MAX_FLAVORS when this list changes! */
+		{ RPC_AUTH_NULL, "null" },
+		{ RPC_AUTH_UNIX, "sys" },
+		{ RPC_AUTH_GSS_KRB5, "krb5" },
+		{ RPC_AUTH_GSS_KRB5I, "krb5i" },
+		{ RPC_AUTH_GSS_KRB5P, "krb5p" },
+		{ RPC_AUTH_GSS_LKEY, "lkey" },
+		{ RPC_AUTH_GSS_LKEYI, "lkeyi" },
+		{ RPC_AUTH_GSS_LKEYP, "lkeyp" },
+		{ RPC_AUTH_GSS_SPKM, "spkm" },
+		{ RPC_AUTH_GSS_SPKMI, "spkmi" },
+		{ RPC_AUTH_GSS_SPKMP, "spkmp" },
+		{ UINT_MAX, "unknown" }
+	};
+	int i;
+
+	for (i = 0; sec_flavours[i].flavour != UINT_MAX; i++) {
+		if (sec_flavours[i].flavour == flavour)
+			break;
+	}
+	return sec_flavours[i].str;
+}
+
+static void nfs_show_mountd_netid(struct seq_file *m, struct nfs_server *nfss,
+				  int showdefaults)
+{
+	struct sockaddr *sap = (struct sockaddr *) &nfss->mountd_address;
+	char *proto = NULL;
+
+	switch (sap->sa_family) {
+	case AF_INET:
+		switch (nfss->mountd_protocol) {
+		case IPPROTO_UDP:
+			proto = RPCBIND_NETID_UDP;
+			break;
+		case IPPROTO_TCP:
+			proto = RPCBIND_NETID_TCP;
+			break;
+		}
+		break;
+	case AF_INET6:
+		switch (nfss->mountd_protocol) {
+		case IPPROTO_UDP:
+			proto = RPCBIND_NETID_UDP6;
+			break;
+		case IPPROTO_TCP:
+			proto = RPCBIND_NETID_TCP6;
+			break;
+		}
+		break;
+	}
+	if (proto || showdefaults)
+		seq_printf(m, ",mountproto=%s", proto ?: "auto");
+}
+
+static void nfs_show_mountd_options(struct seq_file *m, struct nfs_server *nfss,
+				    int showdefaults)
+{
+	struct sockaddr *sap = (struct sockaddr *)&nfss->mountd_address;
+
+	if (nfss->flags & NFS_MOUNT_LEGACY_INTERFACE)
+		return;
+
+	switch (sap->sa_family) {
+	case AF_INET: {
+		struct sockaddr_in *sin = (struct sockaddr_in *)sap;
+		seq_printf(m, ",mountaddr=%pI4", &sin->sin_addr.s_addr);
+		break;
+	}
+	case AF_INET6: {
+		struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
+		seq_printf(m, ",mountaddr=%pI6c", &sin6->sin6_addr);
+		break;
+	}
+	default:
+		if (showdefaults)
+			seq_puts(m, ",mountaddr=unspecified");
+	}
+
+	if (nfss->mountd_version || showdefaults)
+		seq_printf(m, ",mountvers=%u", nfss->mountd_version);
+	if ((nfss->mountd_port &&
+		nfss->mountd_port != (unsigned short)NFS_UNSPEC_PORT) ||
+		showdefaults)
+		seq_printf(m, ",mountport=%u", nfss->mountd_port);
+
+	nfs_show_mountd_netid(m, nfss, showdefaults);
+}
+
+#if IS_ENABLED(CONFIG_NFS_V4)
+static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
+				    int showdefaults)
+{
+	struct nfs_client *clp = nfss->nfs_client;
+
+	seq_printf(m, ",clientaddr=%s", clp->cl_ipaddr);
+}
+#else
+static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
+				    int showdefaults)
+{
+}
+#endif
+
+static void nfs_show_nfs_version(struct seq_file *m,
+		unsigned int version,
+		unsigned int minorversion)
+{
+	seq_printf(m, ",vers=%u", version);
+	if (version == 4)
+		seq_printf(m, ".%u", minorversion);
+}
+
+/*
+ * Describe the mount options in force on this server representation
+ */
+static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss,
+				   int showdefaults)
+{
+	static const struct proc_nfs_info {
+		int flag;
+		const char *str;
+		const char *nostr;
+	} nfs_info[] = {
+		{ NFS_MOUNT_SOFT, ",soft", "" },
+		{ NFS_MOUNT_SOFTERR, ",softerr", "" },
+		{ NFS_MOUNT_SOFTREVAL, ",softreval", "" },
+		{ NFS_MOUNT_POSIX, ",posix", "" },
+		{ NFS_MOUNT_NOCTO, ",nocto", "" },
+		{ NFS_MOUNT_NOAC, ",noac", "" },
+		{ NFS_MOUNT_NONLM, ",nolock", "" },
+		{ NFS_MOUNT_NOACL, ",noacl", "" },
+		{ NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" },
+		{ NFS_MOUNT_UNSHARED, ",nosharecache", "" },
+		{ NFS_MOUNT_NORESVPORT, ",noresvport", "" },
+		{ 0, NULL, NULL }
+	};
+	const struct proc_nfs_info *nfs_infop;
+	struct nfs_client *clp = nfss->nfs_client;
+	u32 version = clp->rpc_ops->version;
+	int local_flock, local_fcntl;
+
+	nfs_show_nfs_version(m, version, clp->cl_minorversion);
+	seq_printf(m, ",rsize=%u", nfss->rsize);
+	seq_printf(m, ",wsize=%u", nfss->wsize);
+	if (nfss->bsize != 0)
+		seq_printf(m, ",bsize=%u", nfss->bsize);
+	seq_printf(m, ",namlen=%u", nfss->namelen);
+	if (nfss->acregmin != NFS_DEF_ACREGMIN*HZ || showdefaults)
+		seq_printf(m, ",acregmin=%u", nfss->acregmin/HZ);
+	if (nfss->acregmax != NFS_DEF_ACREGMAX*HZ || showdefaults)
+		seq_printf(m, ",acregmax=%u", nfss->acregmax/HZ);
+	if (nfss->acdirmin != NFS_DEF_ACDIRMIN*HZ || showdefaults)
+		seq_printf(m, ",acdirmin=%u", nfss->acdirmin/HZ);
+	if (nfss->acdirmax != NFS_DEF_ACDIRMAX*HZ || showdefaults)
+		seq_printf(m, ",acdirmax=%u", nfss->acdirmax/HZ);
+	if (!(nfss->flags & (NFS_MOUNT_SOFT|NFS_MOUNT_SOFTERR)))
+			seq_puts(m, ",hard");
+	for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
+		if (nfss->flags & nfs_infop->flag)
+			seq_puts(m, nfs_infop->str);
+		else
+			seq_puts(m, nfs_infop->nostr);
+	}
+	rcu_read_lock();
+	seq_printf(m, ",proto=%s",
+		   rpc_peeraddr2str(nfss->client, RPC_DISPLAY_NETID));
+	rcu_read_unlock();
+	if (clp->cl_nconnect > 0)
+		seq_printf(m, ",nconnect=%u", clp->cl_nconnect);
+	if (version == 4) {
+		if (nfss->port != NFS_PORT)
+			seq_printf(m, ",port=%u", nfss->port);
+	} else
+		if (nfss->port)
+			seq_printf(m, ",port=%u", nfss->port);
+
+	seq_printf(m, ",timeo=%lu", 10U * nfss->client->cl_timeout->to_initval / HZ);
+	seq_printf(m, ",retrans=%u", nfss->client->cl_timeout->to_retries);
+	seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor));
+
+	if (version != 4)
+		nfs_show_mountd_options(m, nfss, showdefaults);
+	else
+		nfs_show_nfsv4_options(m, nfss, showdefaults);
+
+	if (nfss->options & NFS_OPTION_FSCACHE)
+		seq_puts(m, ",fsc");
+
+	if (nfss->options & NFS_OPTION_MIGRATION)
+		seq_puts(m, ",migration");
+
+	if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG) {
+		if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONE)
+			seq_puts(m, ",lookupcache=none");
+		else
+			seq_puts(m, ",lookupcache=pos");
+	}
+
+	local_flock = nfss->flags & NFS_MOUNT_LOCAL_FLOCK;
+	local_fcntl = nfss->flags & NFS_MOUNT_LOCAL_FCNTL;
+
+	if (!local_flock && !local_fcntl)
+		seq_puts(m, ",local_lock=none");
+	else if (local_flock && local_fcntl)
+		seq_puts(m, ",local_lock=all");
+	else if (local_flock)
+		seq_puts(m, ",local_lock=flock");
+	else
+		seq_puts(m, ",local_lock=posix");
+}
+
+/*
+ * Describe the mount options on this VFS mountpoint
+ */
+int nfs_show_options(struct seq_file *m, struct dentry *root)
+{
+	struct nfs_server *nfss = NFS_SB(root->d_sb);
+
+	nfs_show_mount_options(m, nfss, 0);
+
+	rcu_read_lock();
+	seq_printf(m, ",addr=%s",
+			rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient,
+							RPC_DISPLAY_ADDR));
+	rcu_read_unlock();
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nfs_show_options);
+
+#if IS_ENABLED(CONFIG_NFS_V4)
+static void show_lease(struct seq_file *m, struct nfs_server *server)
+{
+	struct nfs_client *clp = server->nfs_client;
+	unsigned long expire;
+
+	seq_printf(m, ",lease_time=%ld", clp->cl_lease_time / HZ);
+	expire = clp->cl_last_renewal + clp->cl_lease_time;
+	seq_printf(m, ",lease_expired=%ld",
+		   time_after(expire, jiffies) ?  0 : (jiffies - expire) / HZ);
+}
+#ifdef CONFIG_NFS_V4_1
+static void show_sessions(struct seq_file *m, struct nfs_server *server)
+{
+	if (nfs4_has_session(server->nfs_client))
+		seq_puts(m, ",sessions");
+}
+#else
+static void show_sessions(struct seq_file *m, struct nfs_server *server) {}
+#endif
+#endif
+
+#ifdef CONFIG_NFS_V4_1
+static void show_pnfs(struct seq_file *m, struct nfs_server *server)
+{
+	seq_printf(m, ",pnfs=");
+	if (server->pnfs_curr_ld)
+		seq_printf(m, "%s", server->pnfs_curr_ld->name);
+	else
+		seq_printf(m, "not configured");
+}
+
+static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
+{
+	if (nfss->nfs_client && nfss->nfs_client->cl_implid) {
+		struct nfs41_impl_id *impl_id = nfss->nfs_client->cl_implid;
+		seq_printf(m, "\n\timpl_id:\tname='%s',domain='%s',"
+			   "date='%llu,%u'",
+			   impl_id->name, impl_id->domain,
+			   impl_id->date.seconds, impl_id->date.nseconds);
+	}
+}
+#else
+#if IS_ENABLED(CONFIG_NFS_V4)
+static void show_pnfs(struct seq_file *m, struct nfs_server *server)
+{
+}
+#endif
+static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
+{
+}
+#endif
+
+int nfs_show_devname(struct seq_file *m, struct dentry *root)
+{
+	char *page = (char *) __get_free_page(GFP_KERNEL);
+	char *devname, *dummy;
+	int err = 0;
+	if (!page)
+		return -ENOMEM;
+	devname = nfs_path(&dummy, root, page, PAGE_SIZE, 0);
+	if (IS_ERR(devname))
+		err = PTR_ERR(devname);
+	else
+		seq_escape(m, devname, " \t\n\\");
+	free_page((unsigned long)page);
+	return err;
+}
+EXPORT_SYMBOL_GPL(nfs_show_devname);
+
+int nfs_show_path(struct seq_file *m, struct dentry *dentry)
+{
+	seq_puts(m, "/");
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nfs_show_path);
+
+/*
+ * Present statistical information for this VFS mountpoint
+ */
+int nfs_show_stats(struct seq_file *m, struct dentry *root)
+{
+	int i, cpu;
+	struct nfs_server *nfss = NFS_SB(root->d_sb);
+	struct rpc_auth *auth = nfss->client->cl_auth;
+	struct nfs_iostats totals = { };
+
+	seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);
+
+	/*
+	 * Display all mount option settings
+	 */
+	seq_puts(m, "\n\topts:\t");
+	seq_puts(m, sb_rdonly(root->d_sb) ? "ro" : "rw");
+	seq_puts(m, root->d_sb->s_flags & SB_SYNCHRONOUS ? ",sync" : "");
+	seq_puts(m, root->d_sb->s_flags & SB_NOATIME ? ",noatime" : "");
+	seq_puts(m, root->d_sb->s_flags & SB_NODIRATIME ? ",nodiratime" : "");
+	nfs_show_mount_options(m, nfss, 1);
+
+	seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
+
+	show_implementation_id(m, nfss);
+
+	seq_puts(m, "\n\tcaps:\t");
+	seq_printf(m, "caps=0x%x", nfss->caps);
+	seq_printf(m, ",wtmult=%u", nfss->wtmult);
+	seq_printf(m, ",dtsize=%u", nfss->dtsize);
+	seq_printf(m, ",bsize=%u", nfss->bsize);
+	seq_printf(m, ",namlen=%u", nfss->namelen);
+
+#if IS_ENABLED(CONFIG_NFS_V4)
+	if (nfss->nfs_client->rpc_ops->version == 4) {
+		seq_puts(m, "\n\tnfsv4:\t");
+		seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
+		seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
+		seq_printf(m, ",bm2=0x%x", nfss->attr_bitmask[2]);
+		seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
+		show_sessions(m, nfss);
+		show_pnfs(m, nfss);
+		show_lease(m, nfss);
+	}
+#endif
+
+	/*
+	 * Display security flavor in effect for this mount
+	 */
+	seq_printf(m, "\n\tsec:\tflavor=%u", auth->au_ops->au_flavor);
+	if (auth->au_flavor)
+		seq_printf(m, ",pseudoflavor=%u", auth->au_flavor);
+
+	/*
+	 * Display superblock I/O counters
+	 */
+	for_each_possible_cpu(cpu) {
+		struct nfs_iostats *stats;
+
+		preempt_disable();
+		stats = per_cpu_ptr(nfss->io_stats, cpu);
+
+		for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
+			totals.events[i] += stats->events[i];
+		for (i = 0; i < __NFSIOS_BYTESMAX; i++)
+			totals.bytes[i] += stats->bytes[i];
+#ifdef CONFIG_NFS_FSCACHE
+		for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
+			totals.fscache[i] += stats->fscache[i];
+#endif
+
+		preempt_enable();
+	}
+
+	seq_puts(m, "\n\tevents:\t");
+	for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
+		seq_printf(m, "%lu ", totals.events[i]);
+	seq_puts(m, "\n\tbytes:\t");
+	for (i = 0; i < __NFSIOS_BYTESMAX; i++)
+		seq_printf(m, "%Lu ", totals.bytes[i]);
+#ifdef CONFIG_NFS_FSCACHE
+	if (nfss->options & NFS_OPTION_FSCACHE) {
+		seq_puts(m, "\n\tfsc:\t");
+		for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
+			seq_printf(m, "%Lu ", totals.fscache[i]);
+	}
+#endif
+	seq_putc(m, '\n');
+
+	rpc_clnt_show_stats(m, nfss->client);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nfs_show_stats);
+
+/*
+ * Begin unmount by attempting to remove all automounted mountpoints we added
+ * in response to xdev traversals and referrals
+ */
+void nfs_umount_begin(struct super_block *sb)
+{
+	struct nfs_server *server;
+	struct rpc_clnt *rpc;
+
+	server = NFS_SB(sb);
+	/* -EIO all pending I/O */
+	rpc = server->client_acl;
+	if (!IS_ERR(rpc))
+		rpc_killall_tasks(rpc);
+	rpc = server->client;
+	if (!IS_ERR(rpc))
+		rpc_killall_tasks(rpc);
+}
+EXPORT_SYMBOL_GPL(nfs_umount_begin);
+
+/*
+ * Return true if 'match' is in auth_info or auth_info is empty.
+ * Return false otherwise.
+ */
+bool nfs_auth_info_match(const struct nfs_auth_info *auth_info,
+			 rpc_authflavor_t match)
+{
+	int i;
+
+	if (!auth_info->flavor_len)
+		return true;
+
+	for (i = 0; i < auth_info->flavor_len; i++) {
+		if (auth_info->flavors[i] == match)
+			return true;
+	}
+	return false;
+}
+EXPORT_SYMBOL_GPL(nfs_auth_info_match);
+
+/*
+ * Ensure that a specified authtype in ctx->auth_info is supported by
+ * the server. Returns 0 and sets ctx->selected_flavor if it's ok, and
+ * -EACCES if not.
+ */
+static int nfs_verify_authflavors(struct nfs_fs_context *ctx,
+				  rpc_authflavor_t *server_authlist,
+				  unsigned int count)
+{
+	rpc_authflavor_t flavor = RPC_AUTH_MAXFLAVOR;
+	bool found_auth_null = false;
+	unsigned int i;
+
+	/*
+	 * If the sec= mount option is used, the specified flavor or AUTH_NULL
+	 * must be in the list returned by the server.
+	 *
+	 * AUTH_NULL has a special meaning when it's in the server list - it
+	 * means that the server will ignore the rpc creds, so any flavor
+	 * can be used but still use the sec= that was specified.
+	 *
+	 * Note also that the MNT procedure in MNTv1 does not return a list
+	 * of supported security flavors. In this case, nfs_mount() fabricates
+	 * a security flavor list containing just AUTH_NULL.
+	 */
+	for (i = 0; i < count; i++) {
+		flavor = server_authlist[i];
+
+		if (nfs_auth_info_match(&ctx->auth_info, flavor))
+			goto out;
+
+		if (flavor == RPC_AUTH_NULL)
+			found_auth_null = true;
+	}
+
+	if (found_auth_null) {
+		flavor = ctx->auth_info.flavors[0];
+		goto out;
+	}
+
+	dfprintk(MOUNT,
+		 "NFS: specified auth flavors not supported by server\n");
+	return -EACCES;
+
+out:
+	ctx->selected_flavor = flavor;
+	dfprintk(MOUNT, "NFS: using auth flavor %u\n", ctx->selected_flavor);
+	return 0;
+}
+
+/*
+ * Use the remote server's MOUNT service to request the NFS file handle
+ * corresponding to the provided path.
+ */
+static int nfs_request_mount(struct fs_context *fc,
+			     struct nfs_fh *root_fh,
+			     rpc_authflavor_t *server_authlist,
+			     unsigned int *server_authlist_len)
+{
+	struct nfs_fs_context *ctx = nfs_fc2context(fc);
+	struct nfs_mount_request request = {
+		.sap		= (struct sockaddr *)
+						&ctx->mount_server.address,
+		.dirpath	= ctx->nfs_server.export_path,
+		.protocol	= ctx->mount_server.protocol,
+		.fh		= root_fh,
+		.noresvport	= ctx->flags & NFS_MOUNT_NORESVPORT,
+		.auth_flav_len	= server_authlist_len,
+		.auth_flavs	= server_authlist,
+		.net		= fc->net_ns,
+	};
+	int status;
+
+	if (ctx->mount_server.version == 0) {
+		switch (ctx->version) {
+			default:
+				ctx->mount_server.version = NFS_MNT3_VERSION;
+				break;
+			case 2:
+				ctx->mount_server.version = NFS_MNT_VERSION;
+		}
+	}
+	request.version = ctx->mount_server.version;
+
+	if (ctx->mount_server.hostname)
+		request.hostname = ctx->mount_server.hostname;
+	else
+		request.hostname = ctx->nfs_server.hostname;
+
+	/*
+	 * Construct the mount server's address.
+	 */
+	if (ctx->mount_server.address.sa_family == AF_UNSPEC) {
+		memcpy(request.sap, &ctx->nfs_server.address,
+		       ctx->nfs_server.addrlen);
+		ctx->mount_server.addrlen = ctx->nfs_server.addrlen;
+	}
+	request.salen = ctx->mount_server.addrlen;
+	nfs_set_port(request.sap, &ctx->mount_server.port, 0);
+
+	/*
+	 * Now ask the mount server to map our export path
+	 * to a file handle.
+	 */
+	status = nfs_mount(&request);
+	if (status != 0) {
+		dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n",
+				request.hostname, status);
+		return status;
+	}
+
+	return 0;
+}
+
+static struct nfs_server *nfs_try_mount_request(struct fs_context *fc)
+{
+	struct nfs_fs_context *ctx = nfs_fc2context(fc);
+	int status;
+	unsigned int i;
+	bool tried_auth_unix = false;
+	bool auth_null_in_list = false;
+	struct nfs_server *server = ERR_PTR(-EACCES);
+	rpc_authflavor_t authlist[NFS_MAX_SECFLAVORS];
+	unsigned int authlist_len = ARRAY_SIZE(authlist);
+
+	status = nfs_request_mount(fc, ctx->mntfh, authlist, &authlist_len);
+	if (status)
+		return ERR_PTR(status);
+
+	/*
+	 * Was a sec= authflavor specified in the options? First, verify
+	 * whether the server supports it, and then just try to use it if so.
+	 */
+	if (ctx->auth_info.flavor_len > 0) {
+		status = nfs_verify_authflavors(ctx, authlist, authlist_len);
+		dfprintk(MOUNT, "NFS: using auth flavor %u\n",
+			 ctx->selected_flavor);
+		if (status)
+			return ERR_PTR(status);
+		return ctx->nfs_mod->rpc_ops->create_server(fc);
+	}
+
+	/*
+	 * No sec= option was provided. RFC 2623, section 2.7 suggests we
+	 * SHOULD prefer the flavor listed first. However, some servers list
+	 * AUTH_NULL first. Avoid ever choosing AUTH_NULL.
+	 */
+	for (i = 0; i < authlist_len; ++i) {
+		rpc_authflavor_t flavor;
+		struct rpcsec_gss_info info;
+
+		flavor = authlist[i];
+		switch (flavor) {
+		case RPC_AUTH_UNIX:
+			tried_auth_unix = true;
+			break;
+		case RPC_AUTH_NULL:
+			auth_null_in_list = true;
+			continue;
+		default:
+			if (rpcauth_get_gssinfo(flavor, &info) != 0)
+				continue;
+			break;
+		}
+		dfprintk(MOUNT, "NFS: attempting to use auth flavor %u\n", flavor);
+		ctx->selected_flavor = flavor;
+		server = ctx->nfs_mod->rpc_ops->create_server(fc);
+		if (!IS_ERR(server))
+			return server;
+	}
+
+	/*
+	 * Nothing we tried so far worked. At this point, give up if we've
+	 * already tried AUTH_UNIX or if the server's list doesn't contain
+	 * AUTH_NULL
+	 */
+	if (tried_auth_unix || !auth_null_in_list)
+		return server;
+
+	/* Last chance! Try AUTH_UNIX */
+	dfprintk(MOUNT, "NFS: attempting to use auth flavor %u\n", RPC_AUTH_UNIX);
+	ctx->selected_flavor = RPC_AUTH_UNIX;
+	return ctx->nfs_mod->rpc_ops->create_server(fc);
+}
+
+int nfs_try_get_tree(struct fs_context *fc)
+{
+	struct nfs_fs_context *ctx = nfs_fc2context(fc);
+
+	if (ctx->need_mount)
+		ctx->server = nfs_try_mount_request(fc);
+	else
+		ctx->server = ctx->nfs_mod->rpc_ops->create_server(fc);
+
+	return nfs_get_tree_common(fc);
+}
+EXPORT_SYMBOL_GPL(nfs_try_get_tree);
+
+
+#define NFS_REMOUNT_CMP_FLAGMASK ~(NFS_MOUNT_INTR \
+		| NFS_MOUNT_SECURE \
+		| NFS_MOUNT_TCP \
+		| NFS_MOUNT_VER3 \
+		| NFS_MOUNT_KERBEROS \
+		| NFS_MOUNT_NONLM \
+		| NFS_MOUNT_BROKEN_SUID \
+		| NFS_MOUNT_STRICTLOCK \
+		| NFS_MOUNT_LEGACY_INTERFACE)
+
+#define NFS_MOUNT_CMP_FLAGMASK (NFS_REMOUNT_CMP_FLAGMASK & \
+		~(NFS_MOUNT_UNSHARED | NFS_MOUNT_NORESVPORT))
+
+static int
+nfs_compare_remount_data(struct nfs_server *nfss,
+			 struct nfs_fs_context *ctx)
+{
+	if ((ctx->flags ^ nfss->flags) & NFS_REMOUNT_CMP_FLAGMASK ||
+	    ctx->rsize != nfss->rsize ||
+	    ctx->wsize != nfss->wsize ||
+	    ctx->version != nfss->nfs_client->rpc_ops->version ||
+	    ctx->minorversion != nfss->nfs_client->cl_minorversion ||
+	    ctx->retrans != nfss->client->cl_timeout->to_retries ||
+	    !nfs_auth_info_match(&ctx->auth_info, nfss->client->cl_auth->au_flavor) ||
+	    ctx->acregmin != nfss->acregmin / HZ ||
+	    ctx->acregmax != nfss->acregmax / HZ ||
+	    ctx->acdirmin != nfss->acdirmin / HZ ||
+	    ctx->acdirmax != nfss->acdirmax / HZ ||
+	    ctx->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) ||
+	    (ctx->options & NFS_OPTION_FSCACHE) != (nfss->options & NFS_OPTION_FSCACHE) ||
+	    ctx->nfs_server.port != nfss->port ||
+	    ctx->nfs_server.addrlen != nfss->nfs_client->cl_addrlen ||
+	    !rpc_cmp_addr((struct sockaddr *)&ctx->nfs_server.address,
+			  (struct sockaddr *)&nfss->nfs_client->cl_addr))
+		return -EINVAL;
+
+	return 0;
+}
+
+int nfs_reconfigure(struct fs_context *fc)
+{
+	struct nfs_fs_context *ctx = nfs_fc2context(fc);
+	struct super_block *sb = fc->root->d_sb;
+	struct nfs_server *nfss = sb->s_fs_info;
+
+	sync_filesystem(sb);
+
+	/*
+	 * Userspace mount programs that send binary options generally send
+	 * them populated with default values. We have no way to know which
+	 * ones were explicitly specified. Fall back to legacy behavior and
+	 * just return success.
+	 */
+	if (ctx->skip_reconfig_option_check)
+		return 0;
+
+	/*
+	 * noac is a special case. It implies -o sync, but that's not
+	 * necessarily reflected in the mtab options. reconfigure_super
+	 * will clear SB_SYNCHRONOUS if -o sync wasn't specified in the
+	 * remount options, so we have to explicitly reset it.
+	 */
+	if (ctx->flags & NFS_MOUNT_NOAC) {
+		fc->sb_flags |= SB_SYNCHRONOUS;
+		fc->sb_flags_mask |= SB_SYNCHRONOUS;
+	}
+
+	/* compare new mount options with old ones */
+	return nfs_compare_remount_data(nfss, ctx);
+}
+EXPORT_SYMBOL_GPL(nfs_reconfigure);
+
+/*
+ * Finish setting up an NFS superblock
+ */
+static void nfs_fill_super(struct super_block *sb, struct nfs_fs_context *ctx)
+{
+	struct nfs_server *server = NFS_SB(sb);
+
+	sb->s_blocksize_bits = 0;
+	sb->s_blocksize = 0;
+	sb->s_xattr = server->nfs_client->cl_nfs_mod->xattr;
+	sb->s_op = server->nfs_client->cl_nfs_mod->sops;
+	if (ctx && ctx->bsize)
+		sb->s_blocksize = nfs_block_size(ctx->bsize, &sb->s_blocksize_bits);
+
+	switch (server->nfs_client->rpc_ops->version) {
+	case 2:
+		sb->s_time_gran = 1000;
+		sb->s_time_min = 0;
+		sb->s_time_max = U32_MAX;
+		break;
+	case 3:
+		/*
+		 * The VFS shouldn't apply the umask to mode bits.
+		 * We will do so ourselves when necessary.
+		 */
+		sb->s_flags |= SB_POSIXACL;
+		sb->s_time_gran = 1;
+		sb->s_time_min = 0;
+		sb->s_time_max = U32_MAX;
+		sb->s_export_op = &nfs_export_ops;
+		break;
+	case 4:
+		sb->s_flags |= SB_POSIXACL;
+		sb->s_time_gran = 1;
+		sb->s_time_min = S64_MIN;
+		sb->s_time_max = S64_MAX;
+		if (server->caps & NFS_CAP_ATOMIC_OPEN_V1)
+			sb->s_export_op = &nfs_export_ops;
+		break;
+	}
+
+	sb->s_magic = NFS_SUPER_MAGIC;
+
+	/* We probably want something more informative here */
+	snprintf(sb->s_id, sizeof(sb->s_id),
+		 "%u:%u", MAJOR(sb->s_dev), MINOR(sb->s_dev));
+
+	if (sb->s_blocksize == 0)
+		sb->s_blocksize = nfs_block_bits(server->wsize,
+						 &sb->s_blocksize_bits);
+
+	nfs_super_set_maxbytes(sb, server->maxfilesize);
+}
+
+static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b,
+				     const struct fs_context *fc)
+{
+	const struct nfs_server *a = s->s_fs_info;
+	const struct rpc_clnt *clnt_a = a->client;
+	const struct rpc_clnt *clnt_b = b->client;
+
+	if ((s->s_flags & NFS_SB_MASK) != (fc->sb_flags & NFS_SB_MASK))
+		goto Ebusy;
+	if (a->nfs_client != b->nfs_client)
+		goto Ebusy;
+	if ((a->flags ^ b->flags) & NFS_MOUNT_CMP_FLAGMASK)
+		goto Ebusy;
+	if (a->wsize != b->wsize)
+		goto Ebusy;
+	if (a->rsize != b->rsize)
+		goto Ebusy;
+	if (a->acregmin != b->acregmin)
+		goto Ebusy;
+	if (a->acregmax != b->acregmax)
+		goto Ebusy;
+	if (a->acdirmin != b->acdirmin)
+		goto Ebusy;
+	if (a->acdirmax != b->acdirmax)
+		goto Ebusy;
+	if (clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
+		goto Ebusy;
+	return 1;
+Ebusy:
+	return 0;
+}
+
+static int nfs_set_super(struct super_block *s, struct fs_context *fc)
+{
+	struct nfs_server *server = fc->s_fs_info;
+	int ret;
+
+	s->s_d_op = server->nfs_client->rpc_ops->dentry_ops;
+	ret = set_anon_super(s, server);
+	if (ret == 0)
+		server->s_dev = s->s_dev;
+	return ret;
+}
+
+static int nfs_compare_super_address(struct nfs_server *server1,
+				     struct nfs_server *server2)
+{
+	struct sockaddr *sap1, *sap2;
+	struct rpc_xprt *xprt1 = server1->client->cl_xprt;
+	struct rpc_xprt *xprt2 = server2->client->cl_xprt;
+
+	if (!net_eq(xprt1->xprt_net, xprt2->xprt_net))
+		return 0;
+
+	sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
+	sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;
+
+	if (sap1->sa_family != sap2->sa_family)
+		return 0;
+
+	switch (sap1->sa_family) {
+	case AF_INET: {
+		struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
+		struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
+		if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
+			return 0;
+		if (sin1->sin_port != sin2->sin_port)
+			return 0;
+		break;
+	}
+	case AF_INET6: {
+		struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
+		struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
+		if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
+			return 0;
+		if (sin1->sin6_port != sin2->sin6_port)
+			return 0;
+		break;
+	}
+	default:
+		return 0;
+	}
+
+	return 1;
+}
+
+static int nfs_compare_userns(const struct nfs_server *old,
+		const struct nfs_server *new)
+{
+	const struct user_namespace *oldns = &init_user_ns;
+	const struct user_namespace *newns = &init_user_ns;
+
+	if (old->client && old->client->cl_cred)
+		oldns = old->client->cl_cred->user_ns;
+	if (new->client && new->client->cl_cred)
+		newns = new->client->cl_cred->user_ns;
+	if (oldns != newns)
+		return 0;
+	return 1;
+}
+
+static int nfs_compare_super(struct super_block *sb, struct fs_context *fc)
+{
+	struct nfs_server *server = fc->s_fs_info, *old = NFS_SB(sb);
+
+	if (!nfs_compare_super_address(old, server))
+		return 0;
+	/* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
+	if (old->flags & NFS_MOUNT_UNSHARED)
+		return 0;
+	if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
+		return 0;
+	if (!nfs_compare_userns(old, server))
+		return 0;
+	return nfs_compare_mount_options(sb, server, fc);
+}
+
+#ifdef CONFIG_NFS_FSCACHE
+static void nfs_get_cache_cookie(struct super_block *sb,
+				 struct nfs_fs_context *ctx)
+{
+	struct nfs_server *nfss = NFS_SB(sb);
+	char *uniq = NULL;
+	int ulen = 0;
+
+	nfss->fscache_key = NULL;
+	nfss->fscache = NULL;
+
+	if (!ctx)
+		return;
+
+	if (ctx->clone_data.sb) {
+		struct nfs_server *mnt_s = NFS_SB(ctx->clone_data.sb);
+		if (!(mnt_s->options & NFS_OPTION_FSCACHE))
+			return;
+		if (mnt_s->fscache_key) {
+			uniq = mnt_s->fscache_key->key.uniquifier;
+			ulen = mnt_s->fscache_key->key.uniq_len;
+		}
+	} else {
+		if (!(ctx->options & NFS_OPTION_FSCACHE))
+			return;
+		if (ctx->fscache_uniq) {
+			uniq = ctx->fscache_uniq;
+			ulen = strlen(ctx->fscache_uniq);
+		}
+	}
+
+	nfs_fscache_get_super_cookie(sb, uniq, ulen);
+}
+#else
+static void nfs_get_cache_cookie(struct super_block *sb,
+				 struct nfs_fs_context *ctx)
+{
+}
+#endif
+
+int nfs_get_tree_common(struct fs_context *fc)
+{
+	struct nfs_fs_context *ctx = nfs_fc2context(fc);
+	struct super_block *s;
+	int (*compare_super)(struct super_block *, struct fs_context *) = nfs_compare_super;
+	struct nfs_server *server = ctx->server;
+	int error;
+
+	ctx->server = NULL;
+	if (IS_ERR(server))
+		return PTR_ERR(server);
+
+	if (server->flags & NFS_MOUNT_UNSHARED)
+		compare_super = NULL;
+
+	/* -o noac implies -o sync */
+	if (server->flags & NFS_MOUNT_NOAC)
+		fc->sb_flags |= SB_SYNCHRONOUS;
+
+	if (ctx->clone_data.sb)
+		if (ctx->clone_data.sb->s_flags & SB_SYNCHRONOUS)
+			fc->sb_flags |= SB_SYNCHRONOUS;
+
+	if (server->caps & NFS_CAP_SECURITY_LABEL)
+		fc->lsm_flags |= SECURITY_LSM_NATIVE_LABELS;
+
+	/* Get a superblock - note that we may end up sharing one that already exists */
+	fc->s_fs_info = server;
+	s = sget_fc(fc, compare_super, nfs_set_super);
+	fc->s_fs_info = NULL;
+	if (IS_ERR(s)) {
+		error = PTR_ERR(s);
+		nfs_errorf(fc, "NFS: Couldn't get superblock");
+		goto out_err_nosb;
+	}
+
+	if (s->s_fs_info != server) {
+		nfs_free_server(server);
+		server = NULL;
+	} else {
+		error = super_setup_bdi_name(s, "%u:%u", MAJOR(server->s_dev),
+					     MINOR(server->s_dev));
+		if (error)
+			goto error_splat_super;
+		s->s_bdi->io_pages = server->rpages;
+		server->super = s;
+	}
+
+	if (!s->s_root) {
+		unsigned bsize = ctx->clone_data.inherited_bsize;
+		/* initial superblock/root creation */
+		nfs_fill_super(s, ctx);
+		if (bsize) {
+			s->s_blocksize_bits = bsize;
+			s->s_blocksize = 1U << bsize;
+		}
+		nfs_get_cache_cookie(s, ctx);
+	}
+
+	error = nfs_get_root(s, fc);
+	if (error < 0) {
+		nfs_errorf(fc, "NFS: Couldn't get root dentry");
+		goto error_splat_super;
+	}
+
+	s->s_flags |= SB_ACTIVE;
+	error = 0;
+
+out:
+	return error;
+
+out_err_nosb:
+	nfs_free_server(server);
+	goto out;
+error_splat_super:
+	deactivate_locked_super(s);
+	goto out;
+}
+
+/*
+ * Destroy an NFS2/3 superblock
+ */
+void nfs_kill_super(struct super_block *s)
+{
+	struct nfs_server *server = NFS_SB(s);
+	dev_t dev = s->s_dev;
+
+	generic_shutdown_super(s);
+
+	nfs_fscache_release_super_cookie(s);
+
+	nfs_free_server(server);
+	free_anon_bdev(dev);
+}
+EXPORT_SYMBOL_GPL(nfs_kill_super);
+
+#if IS_ENABLED(CONFIG_NFS_V4)
+
+/*
+ * NFS v4 module parameters need to stay in the
+ * NFS client for backwards compatibility
+ */
+unsigned int nfs_callback_set_tcpport;
+unsigned short nfs_callback_nr_threads;
+/* Default cache timeout is 10 minutes */
+unsigned int nfs_idmap_cache_timeout = 600;
+/* Turn off NFSv4 uid/gid mapping when using AUTH_SYS */
+bool nfs4_disable_idmapping = true;
+unsigned short max_session_slots = NFS4_DEF_SLOT_TABLE_SIZE;
+unsigned short max_session_cb_slots = NFS4_DEF_CB_SLOT_TABLE_SIZE;
+unsigned short send_implementation_id = 1;
+char nfs4_client_id_uniquifier[NFS4_CLIENT_ID_UNIQ_LEN] = "";
+bool recover_lost_locks = false;
+
+EXPORT_SYMBOL_GPL(nfs_callback_nr_threads);
+EXPORT_SYMBOL_GPL(nfs_callback_set_tcpport);
+EXPORT_SYMBOL_GPL(nfs_idmap_cache_timeout);
+EXPORT_SYMBOL_GPL(nfs4_disable_idmapping);
+EXPORT_SYMBOL_GPL(max_session_slots);
+EXPORT_SYMBOL_GPL(max_session_cb_slots);
+EXPORT_SYMBOL_GPL(send_implementation_id);
+EXPORT_SYMBOL_GPL(nfs4_client_id_uniquifier);
+EXPORT_SYMBOL_GPL(recover_lost_locks);
+
+#define NFS_CALLBACK_MAXPORTNR (65535U)
+
+static int param_set_portnr(const char *val, const struct kernel_param *kp)
+{
+	unsigned long num;
+	int ret;
+
+	if (!val)
+		return -EINVAL;
+	ret = kstrtoul(val, 0, &num);
+	if (ret || num > NFS_CALLBACK_MAXPORTNR)
+		return -EINVAL;
+	*((unsigned int *)kp->arg) = num;
+	return 0;
+}
+static const struct kernel_param_ops param_ops_portnr = {
+	.set = param_set_portnr,
+	.get = param_get_uint,
+};
+#define param_check_portnr(name, p) __param_check(name, p, unsigned int);
+
+module_param_named(callback_tcpport, nfs_callback_set_tcpport, portnr, 0644);
+module_param_named(callback_nr_threads, nfs_callback_nr_threads, ushort, 0644);
+MODULE_PARM_DESC(callback_nr_threads, "Number of threads that will be "
+		"assigned to the NFSv4 callback channels.");
+module_param(nfs_idmap_cache_timeout, int, 0644);
+module_param(nfs4_disable_idmapping, bool, 0644);
+module_param_string(nfs4_unique_id, nfs4_client_id_uniquifier,
+			NFS4_CLIENT_ID_UNIQ_LEN, 0600);
+MODULE_PARM_DESC(nfs4_disable_idmapping,
+		"Turn off NFSv4 idmapping when using 'sec=sys'");
+module_param(max_session_slots, ushort, 0644);
+MODULE_PARM_DESC(max_session_slots, "Maximum number of outstanding NFSv4.1 "
+		"requests the client will negotiate");
+module_param(max_session_cb_slots, ushort, 0644);
+MODULE_PARM_DESC(max_session_cb_slots, "Maximum number of parallel NFSv4.1 "
+		"callbacks the client will process for a given server");
+module_param(send_implementation_id, ushort, 0644);
+MODULE_PARM_DESC(send_implementation_id,
+		"Send implementation ID with NFSv4.1 exchange_id");
+MODULE_PARM_DESC(nfs4_unique_id, "nfs_client_id4 uniquifier string");
+
+module_param(recover_lost_locks, bool, 0644);
+MODULE_PARM_DESC(recover_lost_locks,
+		 "If the server reports that a lock might be lost, "
+		 "try to recover it risking data corruption.");
+
+
+#endif /* CONFIG_NFS_V4 */
diff --git a/fs/nfs/symlink.c b/fs/nfs/symlink.c
new file mode 100644
index 000000000..25ba299fd
--- /dev/null
+++ b/fs/nfs/symlink.c
@@ -0,0 +1,85 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  linux/fs/nfs/symlink.c
+ *
+ *  Copyright (C) 1992  Rick Sladkey
+ *
+ *  Optimization changes Copyright (C) 1994 Florian La Roche
+ *
+ *  Jun 7 1999, cache symlink lookups in the page cache.  -DaveM
+ *
+ *  nfs symlink handling code
+ */
+
+#include <linux/time.h>
+#include <linux/errno.h>
+#include <linux/sunrpc/clnt.h>
+#include <linux/nfs.h>
+#include <linux/nfs2.h>
+#include <linux/nfs_fs.h>
+#include <linux/pagemap.h>
+#include <linux/stat.h>
+#include <linux/mm.h>
+#include <linux/string.h>
+
+/* Symlink caching in the page cache is even more simplistic
+ * and straight-forward than readdir caching.
+ */
+
+static int nfs_symlink_filler(void *data, struct page *page)
+{
+	struct inode *inode = data;
+	int error;
+
+	error = NFS_PROTO(inode)->readlink(inode, page, 0, PAGE_SIZE);
+	if (error < 0)
+		goto error;
+	SetPageUptodate(page);
+	unlock_page(page);
+	return 0;
+
+error:
+	SetPageError(page);
+	unlock_page(page);
+	return -EIO;
+}
+
+static const char *nfs_get_link(struct dentry *dentry,
+				struct inode *inode,
+				struct delayed_call *done)
+{
+	struct page *page;
+	void *err;
+
+	if (!dentry) {
+		err = ERR_PTR(nfs_revalidate_mapping_rcu(inode));
+		if (err)
+			return err;
+		page = find_get_page(inode->i_mapping, 0);
+		if (!page)
+			return ERR_PTR(-ECHILD);
+		if (!PageUptodate(page)) {
+			put_page(page);
+			return ERR_PTR(-ECHILD);
+		}
+	} else {
+		err = ERR_PTR(nfs_revalidate_mapping(inode, inode->i_mapping));
+		if (err)
+			return err;
+		page = read_cache_page(&inode->i_data, 0, nfs_symlink_filler,
+				inode);
+		if (IS_ERR(page))
+			return ERR_CAST(page);
+	}
+	set_delayed_call(done, page_put_link, page);
+	return page_address(page);
+}
+
+/*
+ * symlinks can't do much...
+ */
+const struct inode_operations nfs_symlink_inode_operations = {
+	.get_link	= nfs_get_link,
+	.getattr	= nfs_getattr,
+	.setattr	= nfs_setattr,
+};
diff --git a/fs/nfs/sysctl.c b/fs/nfs/sysctl.c
new file mode 100644
index 000000000..7aea195dd
--- /dev/null
+++ b/fs/nfs/sysctl.c
@@ -0,0 +1,65 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/nfs/sysctl.c
+ *
+ * Sysctl interface to NFS parameters
+ */
+#include <linux/types.h>
+#include <linux/linkage.h>
+#include <linux/ctype.h>
+#include <linux/fs.h>
+#include <linux/sysctl.h>
+#include <linux/module.h>
+#include <linux/nfs_fs.h>
+
+static struct ctl_table_header *nfs_callback_sysctl_table;
+
+static struct ctl_table nfs_cb_sysctls[] = {
+	{
+		.procname	= "nfs_mountpoint_timeout",
+		.data		= &nfs_mountpoint_expiry_timeout,
+		.maxlen		= sizeof(nfs_mountpoint_expiry_timeout),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec_jiffies,
+	},
+	{
+		.procname	= "nfs_congestion_kb",
+		.data		= &nfs_congestion_kb,
+		.maxlen		= sizeof(nfs_congestion_kb),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec,
+	},
+	{ }
+};
+
+static struct ctl_table nfs_cb_sysctl_dir[] = {
+	{
+		.procname = "nfs",
+		.mode = 0555,
+		.child = nfs_cb_sysctls,
+	},
+	{ }
+};
+
+static struct ctl_table nfs_cb_sysctl_root[] = {
+	{
+		.procname = "fs",
+		.mode = 0555,
+		.child = nfs_cb_sysctl_dir,
+	},
+	{ }
+};
+
+int nfs_register_sysctl(void)
+{
+	nfs_callback_sysctl_table = register_sysctl_table(nfs_cb_sysctl_root);
+	if (nfs_callback_sysctl_table == NULL)
+		return -ENOMEM;
+	return 0;
+}
+
+void nfs_unregister_sysctl(void)
+{
+	unregister_sysctl_table(nfs_callback_sysctl_table);
+	nfs_callback_sysctl_table = NULL;
+}
diff --git a/fs/nfs/sysfs.c b/fs/nfs/sysfs.c
new file mode 100644
index 000000000..f7f778e3e
--- /dev/null
+++ b/fs/nfs/sysfs.c
@@ -0,0 +1,191 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2019 Hammerspace Inc
+ */
+
+#include <linux/module.h>
+#include <linux/kobject.h>
+#include <linux/sysfs.h>
+#include <linux/fs.h>
+#include <linux/slab.h>
+#include <linux/netdevice.h>
+#include <linux/string.h>
+#include <linux/nfs_fs.h>
+#include <linux/rcupdate.h>
+
+#include "nfs4_fs.h"
+#include "netns.h"
+#include "sysfs.h"
+
+struct kobject *nfs_client_kobj;
+static struct kset *nfs_kset;
+
+static void nfs_netns_object_release(struct kobject *kobj)
+{
+	kfree(kobj);
+}
+
+static const struct kobj_ns_type_operations *nfs_netns_object_child_ns_type(
+		struct kobject *kobj)
+{
+	return &net_ns_type_operations;
+}
+
+static struct kobj_type nfs_netns_object_type = {
+	.release = nfs_netns_object_release,
+	.sysfs_ops = &kobj_sysfs_ops,
+	.child_ns_type = nfs_netns_object_child_ns_type,
+};
+
+static struct kobject *nfs_netns_object_alloc(const char *name,
+		struct kset *kset, struct kobject *parent)
+{
+	struct kobject *kobj;
+
+	kobj = kzalloc(sizeof(*kobj), GFP_KERNEL);
+	if (kobj) {
+		kobj->kset = kset;
+		if (kobject_init_and_add(kobj, &nfs_netns_object_type,
+					parent, "%s", name) == 0)
+			return kobj;
+		kobject_put(kobj);
+	}
+	return NULL;
+}
+
+int nfs_sysfs_init(void)
+{
+	nfs_kset = kset_create_and_add("nfs", NULL, fs_kobj);
+	if (!nfs_kset)
+		return -ENOMEM;
+	nfs_client_kobj = nfs_netns_object_alloc("net", nfs_kset, NULL);
+	if  (!nfs_client_kobj) {
+		kset_unregister(nfs_kset);
+		nfs_kset = NULL;
+		return -ENOMEM;
+	}
+	return 0;
+}
+
+void nfs_sysfs_exit(void)
+{
+	kobject_put(nfs_client_kobj);
+	kset_unregister(nfs_kset);
+}
+
+static ssize_t nfs_netns_identifier_show(struct kobject *kobj,
+		struct kobj_attribute *attr, char *buf)
+{
+	struct nfs_netns_client *c = container_of(kobj,
+			struct nfs_netns_client,
+			kobject);
+	ssize_t ret;
+
+	rcu_read_lock();
+	ret = scnprintf(buf, PAGE_SIZE, "%s\n", rcu_dereference(c->identifier));
+	rcu_read_unlock();
+	return ret;
+}
+
+/* Strip trailing '\n' */
+static size_t nfs_string_strip(const char *c, size_t len)
+{
+	while (len > 0 && c[len-1] == '\n')
+		--len;
+	return len;
+}
+
+static ssize_t nfs_netns_identifier_store(struct kobject *kobj,
+		struct kobj_attribute *attr,
+		const char *buf, size_t count)
+{
+	struct nfs_netns_client *c = container_of(kobj,
+			struct nfs_netns_client,
+			kobject);
+	const char *old;
+	char *p;
+	size_t len;
+
+	len = nfs_string_strip(buf, min_t(size_t, count, CONTAINER_ID_MAXLEN));
+	if (!len)
+		return 0;
+	p = kmemdup_nul(buf, len, GFP_KERNEL);
+	if (!p)
+		return -ENOMEM;
+	old = rcu_dereference_protected(xchg(&c->identifier, (char __rcu *)p), 1);
+	if (old) {
+		synchronize_rcu();
+		kfree(old);
+	}
+	return count;
+}
+
+static void nfs_netns_client_release(struct kobject *kobj)
+{
+	struct nfs_netns_client *c = container_of(kobj,
+			struct nfs_netns_client,
+			kobject);
+
+	kfree(rcu_dereference_raw(c->identifier));
+	kfree(c);
+}
+
+static const void *nfs_netns_client_namespace(struct kobject *kobj)
+{
+	return container_of(kobj, struct nfs_netns_client, kobject)->net;
+}
+
+static struct kobj_attribute nfs_netns_client_id = __ATTR(identifier,
+		0644, nfs_netns_identifier_show, nfs_netns_identifier_store);
+
+static struct attribute *nfs_netns_client_attrs[] = {
+	&nfs_netns_client_id.attr,
+	NULL,
+};
+
+static struct kobj_type nfs_netns_client_type = {
+	.release = nfs_netns_client_release,
+	.default_attrs = nfs_netns_client_attrs,
+	.sysfs_ops = &kobj_sysfs_ops,
+	.namespace = nfs_netns_client_namespace,
+};
+
+static struct nfs_netns_client *nfs_netns_client_alloc(struct kobject *parent,
+		struct net *net)
+{
+	struct nfs_netns_client *p;
+
+	p = kzalloc(sizeof(*p), GFP_KERNEL);
+	if (p) {
+		p->net = net;
+		p->kobject.kset = nfs_kset;
+		if (kobject_init_and_add(&p->kobject, &nfs_netns_client_type,
+					parent, "nfs_client") == 0)
+			return p;
+		kobject_put(&p->kobject);
+	}
+	return NULL;
+}
+
+void nfs_netns_sysfs_setup(struct nfs_net *netns, struct net *net)
+{
+	struct nfs_netns_client *clp;
+
+	clp = nfs_netns_client_alloc(nfs_client_kobj, net);
+	if (clp) {
+		netns->nfs_client = clp;
+		kobject_uevent(&clp->kobject, KOBJ_ADD);
+	}
+}
+
+void nfs_netns_sysfs_destroy(struct nfs_net *netns)
+{
+	struct nfs_netns_client *clp = netns->nfs_client;
+
+	if (clp) {
+		kobject_uevent(&clp->kobject, KOBJ_REMOVE);
+		kobject_del(&clp->kobject);
+		kobject_put(&clp->kobject);
+		netns->nfs_client = NULL;
+	}
+}
diff --git a/fs/nfs/sysfs.h b/fs/nfs/sysfs.h
new file mode 100644
index 000000000..5501ef573
--- /dev/null
+++ b/fs/nfs/sysfs.h
@@ -0,0 +1,25 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2019 Hammerspace Inc
+ */
+
+#ifndef __NFS_SYSFS_H
+#define __NFS_SYSFS_H
+
+#define CONTAINER_ID_MAXLEN (64)
+
+struct nfs_netns_client {
+	struct kobject kobject;
+	struct net *net;
+	const char __rcu *identifier;
+};
+
+extern struct kobject *nfs_client_kobj;
+
+extern int nfs_sysfs_init(void);
+extern void nfs_sysfs_exit(void);
+
+void nfs_netns_sysfs_setup(struct nfs_net *netns, struct net *net);
+void nfs_netns_sysfs_destroy(struct nfs_net *netns);
+
+#endif
diff --git a/fs/nfs/unlink.c b/fs/nfs/unlink.c
new file mode 100644
index 000000000..b27ebdcce
--- /dev/null
+++ b/fs/nfs/unlink.c
@@ -0,0 +1,521 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  linux/fs/nfs/unlink.c
+ *
+ * nfs sillydelete handling
+ *
+ */
+
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/dcache.h>
+#include <linux/sunrpc/sched.h>
+#include <linux/sunrpc/clnt.h>
+#include <linux/nfs_fs.h>
+#include <linux/sched.h>
+#include <linux/wait.h>
+#include <linux/namei.h>
+#include <linux/fsnotify.h>
+
+#include "internal.h"
+#include "nfs4_fs.h"
+#include "iostat.h"
+#include "delegation.h"
+
+#include "nfstrace.h"
+
+/**
+ * nfs_free_unlinkdata - release data from a sillydelete operation.
+ * @data: pointer to unlink structure.
+ */
+static void
+nfs_free_unlinkdata(struct nfs_unlinkdata *data)
+{
+	put_cred(data->cred);
+	kfree(data->args.name.name);
+	kfree(data);
+}
+
+/**
+ * nfs_async_unlink_done - Sillydelete post-processing
+ * @task: rpc_task of the sillydelete
+ * @calldata: pointer to nfs_unlinkdata
+ *
+ * Do the directory attribute update.
+ */
+static void nfs_async_unlink_done(struct rpc_task *task, void *calldata)
+{
+	struct nfs_unlinkdata *data = calldata;
+	struct inode *dir = d_inode(data->dentry->d_parent);
+
+	trace_nfs_sillyrename_unlink(data, task->tk_status);
+	if (!NFS_PROTO(dir)->unlink_done(task, dir))
+		rpc_restart_call_prepare(task);
+}
+
+/**
+ * nfs_async_unlink_release - Release the sillydelete data.
+ * @calldata: struct nfs_unlinkdata to release
+ *
+ * We need to call nfs_put_unlinkdata as a 'tk_release' task since the
+ * rpc_task would be freed too.
+ */
+static void nfs_async_unlink_release(void *calldata)
+{
+	struct nfs_unlinkdata	*data = calldata;
+	struct dentry *dentry = data->dentry;
+	struct super_block *sb = dentry->d_sb;
+
+	up_read_non_owner(&NFS_I(d_inode(dentry->d_parent))->rmdir_sem);
+	d_lookup_done(dentry);
+	nfs_free_unlinkdata(data);
+	dput(dentry);
+	nfs_sb_deactive(sb);
+}
+
+static void nfs_unlink_prepare(struct rpc_task *task, void *calldata)
+{
+	struct nfs_unlinkdata *data = calldata;
+	struct inode *dir = d_inode(data->dentry->d_parent);
+	NFS_PROTO(dir)->unlink_rpc_prepare(task, data);
+}
+
+static const struct rpc_call_ops nfs_unlink_ops = {
+	.rpc_call_done = nfs_async_unlink_done,
+	.rpc_release = nfs_async_unlink_release,
+	.rpc_call_prepare = nfs_unlink_prepare,
+};
+
+static void nfs_do_call_unlink(struct inode *inode, struct nfs_unlinkdata *data)
+{
+	struct rpc_message msg = {
+		.rpc_argp = &data->args,
+		.rpc_resp = &data->res,
+		.rpc_cred = data->cred,
+	};
+	struct rpc_task_setup task_setup_data = {
+		.rpc_message = &msg,
+		.callback_ops = &nfs_unlink_ops,
+		.callback_data = data,
+		.workqueue = nfsiod_workqueue,
+		.flags = RPC_TASK_ASYNC | RPC_TASK_CRED_NOREF,
+	};
+	struct rpc_task *task;
+	struct inode *dir = d_inode(data->dentry->d_parent);
+	nfs_sb_active(dir->i_sb);
+	data->args.fh = NFS_FH(dir);
+	nfs_fattr_init(data->res.dir_attr);
+
+	NFS_PROTO(dir)->unlink_setup(&msg, data->dentry, inode);
+
+	task_setup_data.rpc_client = NFS_CLIENT(dir);
+	task = rpc_run_task(&task_setup_data);
+	if (!IS_ERR(task))
+		rpc_put_task_async(task);
+}
+
+static int nfs_call_unlink(struct dentry *dentry, struct inode *inode, struct nfs_unlinkdata *data)
+{
+	struct inode *dir = d_inode(dentry->d_parent);
+	struct dentry *alias;
+
+	down_read_non_owner(&NFS_I(dir)->rmdir_sem);
+	alias = d_alloc_parallel(dentry->d_parent, &data->args.name, &data->wq);
+	if (IS_ERR(alias)) {
+		up_read_non_owner(&NFS_I(dir)->rmdir_sem);
+		return 0;
+	}
+	if (!d_in_lookup(alias)) {
+		int ret;
+		void *devname_garbage = NULL;
+
+		/*
+		 * Hey, we raced with lookup... See if we need to transfer
+		 * the sillyrename information to the aliased dentry.
+		 */
+		spin_lock(&alias->d_lock);
+		if (d_really_is_positive(alias) &&
+		    !(alias->d_flags & DCACHE_NFSFS_RENAMED)) {
+			devname_garbage = alias->d_fsdata;
+			alias->d_fsdata = data;
+			alias->d_flags |= DCACHE_NFSFS_RENAMED;
+			ret = 1;
+		} else
+			ret = 0;
+		spin_unlock(&alias->d_lock);
+		dput(alias);
+		up_read_non_owner(&NFS_I(dir)->rmdir_sem);
+		/*
+		 * If we'd displaced old cached devname, free it.  At that
+		 * point dentry is definitely not a root, so we won't need
+		 * that anymore.
+		 */
+		kfree(devname_garbage);
+		return ret;
+	}
+	data->dentry = alias;
+	nfs_do_call_unlink(inode, data);
+	return 1;
+}
+
+/**
+ * nfs_async_unlink - asynchronous unlinking of a file
+ * @dentry: parent directory of dentry
+ * @name: name of dentry to unlink
+ */
+static int
+nfs_async_unlink(struct dentry *dentry, const struct qstr *name)
+{
+	struct nfs_unlinkdata *data;
+	int status = -ENOMEM;
+	void *devname_garbage = NULL;
+
+	data = kzalloc(sizeof(*data), GFP_KERNEL);
+	if (data == NULL)
+		goto out;
+	data->args.name.name = kstrdup(name->name, GFP_KERNEL);
+	if (!data->args.name.name)
+		goto out_free;
+	data->args.name.len = name->len;
+
+	data->cred = get_current_cred();
+	data->res.dir_attr = &data->dir_attr;
+	init_waitqueue_head(&data->wq);
+
+	status = -EBUSY;
+	spin_lock(&dentry->d_lock);
+	if (dentry->d_flags & DCACHE_NFSFS_RENAMED)
+		goto out_unlock;
+	dentry->d_flags |= DCACHE_NFSFS_RENAMED;
+	devname_garbage = dentry->d_fsdata;
+	dentry->d_fsdata = data;
+	spin_unlock(&dentry->d_lock);
+	/*
+	 * If we'd displaced old cached devname, free it.  At that
+	 * point dentry is definitely not a root, so we won't need
+	 * that anymore.
+	 */
+	kfree(devname_garbage);
+	return 0;
+out_unlock:
+	spin_unlock(&dentry->d_lock);
+	put_cred(data->cred);
+	kfree(data->args.name.name);
+out_free:
+	kfree(data);
+out:
+	return status;
+}
+
+/**
+ * nfs_complete_unlink - Initialize completion of the sillydelete
+ * @dentry: dentry to delete
+ * @inode: inode
+ *
+ * Since we're most likely to be called by dentry_iput(), we
+ * only use the dentry to find the sillydelete. We then copy the name
+ * into the qstr.
+ */
+void
+nfs_complete_unlink(struct dentry *dentry, struct inode *inode)
+{
+	struct nfs_unlinkdata	*data;
+
+	spin_lock(&dentry->d_lock);
+	dentry->d_flags &= ~DCACHE_NFSFS_RENAMED;
+	data = dentry->d_fsdata;
+	dentry->d_fsdata = NULL;
+	spin_unlock(&dentry->d_lock);
+
+	if (NFS_STALE(inode) || !nfs_call_unlink(dentry, inode, data))
+		nfs_free_unlinkdata(data);
+}
+
+/* Cancel a queued async unlink. Called when a sillyrename run fails. */
+static void
+nfs_cancel_async_unlink(struct dentry *dentry)
+{
+	spin_lock(&dentry->d_lock);
+	if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
+		struct nfs_unlinkdata *data = dentry->d_fsdata;
+
+		dentry->d_flags &= ~DCACHE_NFSFS_RENAMED;
+		dentry->d_fsdata = NULL;
+		spin_unlock(&dentry->d_lock);
+		nfs_free_unlinkdata(data);
+		return;
+	}
+	spin_unlock(&dentry->d_lock);
+}
+
+/**
+ * nfs_async_rename_done - Sillyrename post-processing
+ * @task: rpc_task of the sillyrename
+ * @calldata: nfs_renamedata for the sillyrename
+ *
+ * Do the directory attribute updates and the d_move
+ */
+static void nfs_async_rename_done(struct rpc_task *task, void *calldata)
+{
+	struct nfs_renamedata *data = calldata;
+	struct inode *old_dir = data->old_dir;
+	struct inode *new_dir = data->new_dir;
+	struct dentry *old_dentry = data->old_dentry;
+
+	trace_nfs_sillyrename_rename(old_dir, old_dentry,
+			new_dir, data->new_dentry, task->tk_status);
+	if (!NFS_PROTO(old_dir)->rename_done(task, old_dir, new_dir)) {
+		rpc_restart_call_prepare(task);
+		return;
+	}
+
+	if (data->complete)
+		data->complete(task, data);
+}
+
+/**
+ * nfs_async_rename_release - Release the sillyrename data.
+ * @calldata: the struct nfs_renamedata to be released
+ */
+static void nfs_async_rename_release(void *calldata)
+{
+	struct nfs_renamedata	*data = calldata;
+	struct super_block *sb = data->old_dir->i_sb;
+
+	if (d_really_is_positive(data->old_dentry))
+		nfs_mark_for_revalidate(d_inode(data->old_dentry));
+
+	/* The result of the rename is unknown. Play it safe by
+	 * forcing a new lookup */
+	if (data->cancelled) {
+		spin_lock(&data->old_dir->i_lock);
+		nfs_force_lookup_revalidate(data->old_dir);
+		spin_unlock(&data->old_dir->i_lock);
+		if (data->new_dir != data->old_dir) {
+			spin_lock(&data->new_dir->i_lock);
+			nfs_force_lookup_revalidate(data->new_dir);
+			spin_unlock(&data->new_dir->i_lock);
+		}
+	}
+
+	dput(data->old_dentry);
+	dput(data->new_dentry);
+	iput(data->old_dir);
+	iput(data->new_dir);
+	nfs_sb_deactive(sb);
+	put_cred(data->cred);
+	kfree(data);
+}
+
+static void nfs_rename_prepare(struct rpc_task *task, void *calldata)
+{
+	struct nfs_renamedata *data = calldata;
+	NFS_PROTO(data->old_dir)->rename_rpc_prepare(task, data);
+}
+
+static const struct rpc_call_ops nfs_rename_ops = {
+	.rpc_call_done = nfs_async_rename_done,
+	.rpc_release = nfs_async_rename_release,
+	.rpc_call_prepare = nfs_rename_prepare,
+};
+
+/**
+ * nfs_async_rename - perform an asynchronous rename operation
+ * @old_dir: directory that currently holds the dentry to be renamed
+ * @new_dir: target directory for the rename
+ * @old_dentry: original dentry to be renamed
+ * @new_dentry: dentry to which the old_dentry should be renamed
+ * @complete: Function to run on successful completion
+ *
+ * It's expected that valid references to the dentries and inodes are held
+ */
+struct rpc_task *
+nfs_async_rename(struct inode *old_dir, struct inode *new_dir,
+		 struct dentry *old_dentry, struct dentry *new_dentry,
+		 void (*complete)(struct rpc_task *, struct nfs_renamedata *))
+{
+	struct nfs_renamedata *data;
+	struct rpc_message msg = { };
+	struct rpc_task_setup task_setup_data = {
+		.rpc_message = &msg,
+		.callback_ops = &nfs_rename_ops,
+		.workqueue = nfsiod_workqueue,
+		.rpc_client = NFS_CLIENT(old_dir),
+		.flags = RPC_TASK_ASYNC | RPC_TASK_CRED_NOREF,
+	};
+
+	data = kzalloc(sizeof(*data), GFP_KERNEL);
+	if (data == NULL)
+		return ERR_PTR(-ENOMEM);
+	task_setup_data.callback_data = data;
+
+	data->cred = get_current_cred();
+
+	msg.rpc_argp = &data->args;
+	msg.rpc_resp = &data->res;
+	msg.rpc_cred = data->cred;
+
+	/* set up nfs_renamedata */
+	data->old_dir = old_dir;
+	ihold(old_dir);
+	data->new_dir = new_dir;
+	ihold(new_dir);
+	data->old_dentry = dget(old_dentry);
+	data->new_dentry = dget(new_dentry);
+	nfs_fattr_init(&data->old_fattr);
+	nfs_fattr_init(&data->new_fattr);
+	data->complete = complete;
+
+	/* set up nfs_renameargs */
+	data->args.old_dir = NFS_FH(old_dir);
+	data->args.old_name = &old_dentry->d_name;
+	data->args.new_dir = NFS_FH(new_dir);
+	data->args.new_name = &new_dentry->d_name;
+
+	/* set up nfs_renameres */
+	data->res.old_fattr = &data->old_fattr;
+	data->res.new_fattr = &data->new_fattr;
+
+	nfs_sb_active(old_dir->i_sb);
+
+	NFS_PROTO(data->old_dir)->rename_setup(&msg, old_dentry, new_dentry);
+
+	return rpc_run_task(&task_setup_data);
+}
+
+/*
+ * Perform tasks needed when a sillyrename is done such as cancelling the
+ * queued async unlink if it failed.
+ */
+static void
+nfs_complete_sillyrename(struct rpc_task *task, struct nfs_renamedata *data)
+{
+	struct dentry *dentry = data->old_dentry;
+
+	if (task->tk_status != 0) {
+		nfs_cancel_async_unlink(dentry);
+		return;
+	}
+}
+
+#define SILLYNAME_PREFIX ".nfs"
+#define SILLYNAME_PREFIX_LEN ((unsigned)sizeof(SILLYNAME_PREFIX) - 1)
+#define SILLYNAME_FILEID_LEN ((unsigned)sizeof(u64) << 1)
+#define SILLYNAME_COUNTER_LEN ((unsigned)sizeof(unsigned int) << 1)
+#define SILLYNAME_LEN (SILLYNAME_PREFIX_LEN + \
+		SILLYNAME_FILEID_LEN + \
+		SILLYNAME_COUNTER_LEN)
+
+/**
+ * nfs_sillyrename - Perform a silly-rename of a dentry
+ * @dir: inode of directory that contains dentry
+ * @dentry: dentry to be sillyrenamed
+ *
+ * NFSv2/3 is stateless and the server doesn't know when the client is
+ * holding a file open. To prevent application problems when a file is
+ * unlinked while it's still open, the client performs a "silly-rename".
+ * That is, it renames the file to a hidden file in the same directory,
+ * and only performs the unlink once the last reference to it is put.
+ *
+ * The final cleanup is done during dentry_iput.
+ *
+ * (Note: NFSv4 is stateful, and has opens, so in theory an NFSv4 server
+ * could take responsibility for keeping open files referenced.  The server
+ * would also need to ensure that opened-but-deleted files were kept over
+ * reboots.  However, we may not assume a server does so.  (RFC 5661
+ * does provide an OPEN4_RESULT_PRESERVE_UNLINKED flag that a server can
+ * use to advertise that it does this; some day we may take advantage of
+ * it.))
+ */
+int
+nfs_sillyrename(struct inode *dir, struct dentry *dentry)
+{
+	static unsigned int sillycounter;
+	unsigned char silly[SILLYNAME_LEN + 1];
+	unsigned long long fileid;
+	struct dentry *sdentry;
+	struct inode *inode = d_inode(dentry);
+	struct rpc_task *task;
+	int            error = -EBUSY;
+
+	dfprintk(VFS, "NFS: silly-rename(%pd2, ct=%d)\n",
+		dentry, d_count(dentry));
+	nfs_inc_stats(dir, NFSIOS_SILLYRENAME);
+
+	/*
+	 * We don't allow a dentry to be silly-renamed twice.
+	 */
+	if (dentry->d_flags & DCACHE_NFSFS_RENAMED)
+		goto out;
+
+	fileid = NFS_FILEID(d_inode(dentry));
+
+	sdentry = NULL;
+	do {
+		int slen;
+		dput(sdentry);
+		sillycounter++;
+		slen = scnprintf(silly, sizeof(silly),
+				SILLYNAME_PREFIX "%0*llx%0*x",
+				SILLYNAME_FILEID_LEN, fileid,
+				SILLYNAME_COUNTER_LEN, sillycounter);
+
+		dfprintk(VFS, "NFS: trying to rename %pd to %s\n",
+				dentry, silly);
+
+		sdentry = lookup_one_len(silly, dentry->d_parent, slen);
+		/*
+		 * N.B. Better to return EBUSY here ... it could be
+		 * dangerous to delete the file while it's in use.
+		 */
+		if (IS_ERR(sdentry))
+			goto out;
+	} while (d_inode(sdentry) != NULL); /* need negative lookup */
+
+	ihold(inode);
+
+	/* queue unlink first. Can't do this from rpc_release as it
+	 * has to allocate memory
+	 */
+	error = nfs_async_unlink(dentry, &sdentry->d_name);
+	if (error)
+		goto out_dput;
+
+	/* run the rename task, undo unlink if it fails */
+	task = nfs_async_rename(dir, dir, dentry, sdentry,
+					nfs_complete_sillyrename);
+	if (IS_ERR(task)) {
+		error = -EBUSY;
+		nfs_cancel_async_unlink(dentry);
+		goto out_dput;
+	}
+
+	/* wait for the RPC task to complete, unless a SIGKILL intervenes */
+	error = rpc_wait_for_completion_task(task);
+	if (error == 0)
+		error = task->tk_status;
+	switch (error) {
+	case 0:
+		/* The rename succeeded */
+		nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
+		spin_lock(&inode->i_lock);
+		NFS_I(inode)->attr_gencount = nfs_inc_attr_generation_counter();
+		NFS_I(inode)->cache_validity |= NFS_INO_INVALID_CHANGE
+			| NFS_INO_INVALID_CTIME
+			| NFS_INO_REVAL_FORCED;
+		spin_unlock(&inode->i_lock);
+		d_move(dentry, sdentry);
+		break;
+	case -ERESTARTSYS:
+		/* The result of the rename is unknown. Play it safe by
+		 * forcing a new lookup */
+		d_drop(dentry);
+		d_drop(sdentry);
+	}
+	rpc_put_task(task);
+out_dput:
+	iput(inode);
+	dput(sdentry);
+out:
+	return error;
+}
diff --git a/fs/nfs/write.c b/fs/nfs/write.c
new file mode 100644
index 000000000..d3cd099ff
--- /dev/null
+++ b/fs/nfs/write.c
@@ -0,0 +1,2180 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * linux/fs/nfs/write.c
+ *
+ * Write file data over NFS.
+ *
+ * Copyright (C) 1996, 1997, Olaf Kirch <okir@monad.swb.de>
+ */
+
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/mm.h>
+#include <linux/pagemap.h>
+#include <linux/file.h>
+#include <linux/writeback.h>
+#include <linux/swap.h>
+#include <linux/migrate.h>
+
+#include <linux/sunrpc/clnt.h>
+#include <linux/nfs_fs.h>
+#include <linux/nfs_mount.h>
+#include <linux/nfs_page.h>
+#include <linux/backing-dev.h>
+#include <linux/export.h>
+#include <linux/freezer.h>
+#include <linux/wait.h>
+#include <linux/iversion.h>
+
+#include <linux/uaccess.h>
+#include <linux/sched/mm.h>
+
+#include "delegation.h"
+#include "internal.h"
+#include "iostat.h"
+#include "nfs4_fs.h"
+#include "fscache.h"
+#include "pnfs.h"
+
+#include "nfstrace.h"
+
+#define NFSDBG_FACILITY		NFSDBG_PAGECACHE
+
+#define MIN_POOL_WRITE		(32)
+#define MIN_POOL_COMMIT		(4)
+
+struct nfs_io_completion {
+	void (*complete)(void *data);
+	void *data;
+	struct kref refcount;
+};
+
+/*
+ * Local function declarations
+ */
+static void nfs_redirty_request(struct nfs_page *req);
+static const struct rpc_call_ops nfs_commit_ops;
+static const struct nfs_pgio_completion_ops nfs_async_write_completion_ops;
+static const struct nfs_commit_completion_ops nfs_commit_completion_ops;
+static const struct nfs_rw_ops nfs_rw_write_ops;
+static void nfs_inode_remove_request(struct nfs_page *req);
+static void nfs_clear_request_commit(struct nfs_commit_info *cinfo,
+				     struct nfs_page *req);
+static void nfs_init_cinfo_from_inode(struct nfs_commit_info *cinfo,
+				      struct inode *inode);
+static struct nfs_page *
+nfs_page_search_commits_for_head_request_locked(struct nfs_inode *nfsi,
+						struct page *page);
+
+static struct kmem_cache *nfs_wdata_cachep;
+static mempool_t *nfs_wdata_mempool;
+static struct kmem_cache *nfs_cdata_cachep;
+static mempool_t *nfs_commit_mempool;
+
+struct nfs_commit_data *nfs_commitdata_alloc(void)
+{
+	struct nfs_commit_data *p;
+
+	p = kmem_cache_zalloc(nfs_cdata_cachep, nfs_io_gfp_mask());
+	if (!p) {
+		p = mempool_alloc(nfs_commit_mempool, GFP_NOWAIT);
+		if (!p)
+			return NULL;
+		memset(p, 0, sizeof(*p));
+	}
+	INIT_LIST_HEAD(&p->pages);
+	return p;
+}
+EXPORT_SYMBOL_GPL(nfs_commitdata_alloc);
+
+void nfs_commit_free(struct nfs_commit_data *p)
+{
+	mempool_free(p, nfs_commit_mempool);
+}
+EXPORT_SYMBOL_GPL(nfs_commit_free);
+
+static struct nfs_pgio_header *nfs_writehdr_alloc(void)
+{
+	struct nfs_pgio_header *p;
+
+	p = kmem_cache_zalloc(nfs_wdata_cachep, nfs_io_gfp_mask());
+	if (!p) {
+		p = mempool_alloc(nfs_wdata_mempool, GFP_NOWAIT);
+		if (!p)
+			return NULL;
+		memset(p, 0, sizeof(*p));
+	}
+	p->rw_mode = FMODE_WRITE;
+	return p;
+}
+
+static void nfs_writehdr_free(struct nfs_pgio_header *hdr)
+{
+	mempool_free(hdr, nfs_wdata_mempool);
+}
+
+static struct nfs_io_completion *nfs_io_completion_alloc(gfp_t gfp_flags)
+{
+	return kmalloc(sizeof(struct nfs_io_completion), gfp_flags);
+}
+
+static void nfs_io_completion_init(struct nfs_io_completion *ioc,
+		void (*complete)(void *), void *data)
+{
+	ioc->complete = complete;
+	ioc->data = data;
+	kref_init(&ioc->refcount);
+}
+
+static void nfs_io_completion_release(struct kref *kref)
+{
+	struct nfs_io_completion *ioc = container_of(kref,
+			struct nfs_io_completion, refcount);
+	ioc->complete(ioc->data);
+	kfree(ioc);
+}
+
+static void nfs_io_completion_get(struct nfs_io_completion *ioc)
+{
+	if (ioc != NULL)
+		kref_get(&ioc->refcount);
+}
+
+static void nfs_io_completion_put(struct nfs_io_completion *ioc)
+{
+	if (ioc != NULL)
+		kref_put(&ioc->refcount, nfs_io_completion_release);
+}
+
+static void
+nfs_page_set_inode_ref(struct nfs_page *req, struct inode *inode)
+{
+	if (!test_and_set_bit(PG_INODE_REF, &req->wb_flags)) {
+		kref_get(&req->wb_kref);
+		atomic_long_inc(&NFS_I(inode)->nrequests);
+	}
+}
+
+static int
+nfs_cancel_remove_inode(struct nfs_page *req, struct inode *inode)
+{
+	int ret;
+
+	if (!test_bit(PG_REMOVE, &req->wb_flags))
+		return 0;
+	ret = nfs_page_group_lock(req);
+	if (ret)
+		return ret;
+	if (test_and_clear_bit(PG_REMOVE, &req->wb_flags))
+		nfs_page_set_inode_ref(req, inode);
+	nfs_page_group_unlock(req);
+	return 0;
+}
+
+static struct nfs_page *
+nfs_page_private_request(struct page *page)
+{
+	if (!PagePrivate(page))
+		return NULL;
+	return (struct nfs_page *)page_private(page);
+}
+
+/*
+ * nfs_page_find_head_request_locked - find head request associated with @page
+ *
+ * must be called while holding the inode lock.
+ *
+ * returns matching head request with reference held, or NULL if not found.
+ */
+static struct nfs_page *
+nfs_page_find_private_request(struct page *page)
+{
+	struct address_space *mapping = page_file_mapping(page);
+	struct nfs_page *req;
+
+	if (!PagePrivate(page))
+		return NULL;
+	spin_lock(&mapping->private_lock);
+	req = nfs_page_private_request(page);
+	if (req) {
+		WARN_ON_ONCE(req->wb_head != req);
+		kref_get(&req->wb_kref);
+	}
+	spin_unlock(&mapping->private_lock);
+	return req;
+}
+
+static struct nfs_page *
+nfs_page_find_swap_request(struct page *page)
+{
+	struct inode *inode = page_file_mapping(page)->host;
+	struct nfs_inode *nfsi = NFS_I(inode);
+	struct nfs_page *req = NULL;
+	if (!PageSwapCache(page))
+		return NULL;
+	mutex_lock(&nfsi->commit_mutex);
+	if (PageSwapCache(page)) {
+		req = nfs_page_search_commits_for_head_request_locked(nfsi,
+			page);
+		if (req) {
+			WARN_ON_ONCE(req->wb_head != req);
+			kref_get(&req->wb_kref);
+		}
+	}
+	mutex_unlock(&nfsi->commit_mutex);
+	return req;
+}
+
+/*
+ * nfs_page_find_head_request - find head request associated with @page
+ *
+ * returns matching head request with reference held, or NULL if not found.
+ */
+static struct nfs_page *nfs_page_find_head_request(struct page *page)
+{
+	struct nfs_page *req;
+
+	req = nfs_page_find_private_request(page);
+	if (!req)
+		req = nfs_page_find_swap_request(page);
+	return req;
+}
+
+static struct nfs_page *nfs_find_and_lock_page_request(struct page *page)
+{
+	struct inode *inode = page_file_mapping(page)->host;
+	struct nfs_page *req, *head;
+	int ret;
+
+	for (;;) {
+		req = nfs_page_find_head_request(page);
+		if (!req)
+			return req;
+		head = nfs_page_group_lock_head(req);
+		if (head != req)
+			nfs_release_request(req);
+		if (IS_ERR(head))
+			return head;
+		ret = nfs_cancel_remove_inode(head, inode);
+		if (ret < 0) {
+			nfs_unlock_and_release_request(head);
+			return ERR_PTR(ret);
+		}
+		/* Ensure that nobody removed the request before we locked it */
+		if (head == nfs_page_private_request(page))
+			break;
+		if (PageSwapCache(page))
+			break;
+		nfs_unlock_and_release_request(head);
+	}
+	return head;
+}
+
+/* Adjust the file length if we're writing beyond the end */
+static void nfs_grow_file(struct page *page, unsigned int offset, unsigned int count)
+{
+	struct inode *inode = page_file_mapping(page)->host;
+	loff_t end, i_size;
+	pgoff_t end_index;
+
+	spin_lock(&inode->i_lock);
+	i_size = i_size_read(inode);
+	end_index = (i_size - 1) >> PAGE_SHIFT;
+	if (i_size > 0 && page_index(page) < end_index)
+		goto out;
+	end = page_file_offset(page) + ((loff_t)offset+count);
+	if (i_size >= end)
+		goto out;
+	i_size_write(inode, end);
+	NFS_I(inode)->cache_validity &= ~NFS_INO_INVALID_SIZE;
+	nfs_inc_stats(inode, NFSIOS_EXTENDWRITE);
+out:
+	spin_unlock(&inode->i_lock);
+}
+
+/* A writeback failed: mark the page as bad, and invalidate the page cache */
+static void nfs_set_pageerror(struct address_space *mapping)
+{
+	struct inode *inode = mapping->host;
+
+	nfs_zap_mapping(mapping->host, mapping);
+	/* Force file size revalidation */
+	spin_lock(&inode->i_lock);
+	NFS_I(inode)->cache_validity |= NFS_INO_REVAL_FORCED |
+					NFS_INO_REVAL_PAGECACHE |
+					NFS_INO_INVALID_SIZE;
+	spin_unlock(&inode->i_lock);
+}
+
+static void nfs_mapping_set_error(struct page *page, int error)
+{
+	struct address_space *mapping = page_file_mapping(page);
+
+	SetPageError(page);
+	filemap_set_wb_err(mapping, error);
+	if (mapping->host)
+		errseq_set(&mapping->host->i_sb->s_wb_err,
+			   error == -ENOSPC ? -ENOSPC : -EIO);
+	nfs_set_pageerror(mapping);
+}
+
+/*
+ * nfs_page_group_search_locked
+ * @head - head request of page group
+ * @page_offset - offset into page
+ *
+ * Search page group with head @head to find a request that contains the
+ * page offset @page_offset.
+ *
+ * Returns a pointer to the first matching nfs request, or NULL if no
+ * match is found.
+ *
+ * Must be called with the page group lock held
+ */
+static struct nfs_page *
+nfs_page_group_search_locked(struct nfs_page *head, unsigned int page_offset)
+{
+	struct nfs_page *req;
+
+	req = head;
+	do {
+		if (page_offset >= req->wb_pgbase &&
+		    page_offset < (req->wb_pgbase + req->wb_bytes))
+			return req;
+
+		req = req->wb_this_page;
+	} while (req != head);
+
+	return NULL;
+}
+
+/*
+ * nfs_page_group_covers_page
+ * @head - head request of page group
+ *
+ * Return true if the page group with head @head covers the whole page,
+ * returns false otherwise
+ */
+static bool nfs_page_group_covers_page(struct nfs_page *req)
+{
+	struct nfs_page *tmp;
+	unsigned int pos = 0;
+	unsigned int len = nfs_page_length(req->wb_page);
+
+	nfs_page_group_lock(req);
+
+	for (;;) {
+		tmp = nfs_page_group_search_locked(req->wb_head, pos);
+		if (!tmp)
+			break;
+		pos = tmp->wb_pgbase + tmp->wb_bytes;
+	}
+
+	nfs_page_group_unlock(req);
+	return pos >= len;
+}
+
+/* We can set the PG_uptodate flag if we see that a write request
+ * covers the full page.
+ */
+static void nfs_mark_uptodate(struct nfs_page *req)
+{
+	if (PageUptodate(req->wb_page))
+		return;
+	if (!nfs_page_group_covers_page(req))
+		return;
+	SetPageUptodate(req->wb_page);
+}
+
+static int wb_priority(struct writeback_control *wbc)
+{
+	int ret = 0;
+
+	if (wbc->sync_mode == WB_SYNC_ALL)
+		ret = FLUSH_COND_STABLE;
+	return ret;
+}
+
+/*
+ * NFS congestion control
+ */
+
+int nfs_congestion_kb;
+
+#define NFS_CONGESTION_ON_THRESH 	(nfs_congestion_kb >> (PAGE_SHIFT-10))
+#define NFS_CONGESTION_OFF_THRESH	\
+	(NFS_CONGESTION_ON_THRESH - (NFS_CONGESTION_ON_THRESH >> 2))
+
+static void nfs_set_page_writeback(struct page *page)
+{
+	struct inode *inode = page_file_mapping(page)->host;
+	struct nfs_server *nfss = NFS_SERVER(inode);
+	int ret = test_set_page_writeback(page);
+
+	WARN_ON_ONCE(ret != 0);
+
+	if (atomic_long_inc_return(&nfss->writeback) >
+			NFS_CONGESTION_ON_THRESH)
+		set_bdi_congested(inode_to_bdi(inode), BLK_RW_ASYNC);
+}
+
+static void nfs_end_page_writeback(struct nfs_page *req)
+{
+	struct inode *inode = page_file_mapping(req->wb_page)->host;
+	struct nfs_server *nfss = NFS_SERVER(inode);
+	bool is_done;
+
+	is_done = nfs_page_group_sync_on_bit(req, PG_WB_END);
+	nfs_unlock_request(req);
+	if (!is_done)
+		return;
+
+	end_page_writeback(req->wb_page);
+	if (atomic_long_dec_return(&nfss->writeback) < NFS_CONGESTION_OFF_THRESH)
+		clear_bdi_congested(inode_to_bdi(inode), BLK_RW_ASYNC);
+}
+
+/*
+ * nfs_destroy_unlinked_subrequests - destroy recently unlinked subrequests
+ *
+ * @destroy_list - request list (using wb_this_page) terminated by @old_head
+ * @old_head - the old head of the list
+ *
+ * All subrequests must be locked and removed from all lists, so at this point
+ * they are only "active" in this function, and possibly in nfs_wait_on_request
+ * with a reference held by some other context.
+ */
+static void
+nfs_destroy_unlinked_subrequests(struct nfs_page *destroy_list,
+				 struct nfs_page *old_head,
+				 struct inode *inode)
+{
+	while (destroy_list) {
+		struct nfs_page *subreq = destroy_list;
+
+		destroy_list = (subreq->wb_this_page == old_head) ?
+				   NULL : subreq->wb_this_page;
+
+		/* Note: lock subreq in order to change subreq->wb_head */
+		nfs_page_set_headlock(subreq);
+		WARN_ON_ONCE(old_head != subreq->wb_head);
+
+		/* make sure old group is not used */
+		subreq->wb_this_page = subreq;
+		subreq->wb_head = subreq;
+
+		clear_bit(PG_REMOVE, &subreq->wb_flags);
+
+		/* Note: races with nfs_page_group_destroy() */
+		if (!kref_read(&subreq->wb_kref)) {
+			/* Check if we raced with nfs_page_group_destroy() */
+			if (test_and_clear_bit(PG_TEARDOWN, &subreq->wb_flags)) {
+				nfs_page_clear_headlock(subreq);
+				nfs_free_request(subreq);
+			} else
+				nfs_page_clear_headlock(subreq);
+			continue;
+		}
+		nfs_page_clear_headlock(subreq);
+
+		nfs_release_request(old_head);
+
+		if (test_and_clear_bit(PG_INODE_REF, &subreq->wb_flags)) {
+			nfs_release_request(subreq);
+			atomic_long_dec(&NFS_I(inode)->nrequests);
+		}
+
+		/* subreq is now totally disconnected from page group or any
+		 * write / commit lists. last chance to wake any waiters */
+		nfs_unlock_and_release_request(subreq);
+	}
+}
+
+/*
+ * nfs_join_page_group - destroy subrequests of the head req
+ * @head: the page used to lookup the "page group" of nfs_page structures
+ * @inode: Inode to which the request belongs.
+ *
+ * This function joins all sub requests to the head request by first
+ * locking all requests in the group, cancelling any pending operations
+ * and finally updating the head request to cover the whole range covered by
+ * the (former) group.  All subrequests are removed from any write or commit
+ * lists, unlinked from the group and destroyed.
+ */
+void nfs_join_page_group(struct nfs_page *head, struct nfs_commit_info *cinfo,
+			 struct inode *inode)
+{
+	struct nfs_page *subreq;
+	struct nfs_page *destroy_list = NULL;
+	unsigned int pgbase, off, bytes;
+
+	pgbase = head->wb_pgbase;
+	bytes = head->wb_bytes;
+	off = head->wb_offset;
+	for (subreq = head->wb_this_page; subreq != head;
+			subreq = subreq->wb_this_page) {
+		/* Subrequests should always form a contiguous range */
+		if (pgbase > subreq->wb_pgbase) {
+			off -= pgbase - subreq->wb_pgbase;
+			bytes += pgbase - subreq->wb_pgbase;
+			pgbase = subreq->wb_pgbase;
+		}
+		bytes = max(subreq->wb_pgbase + subreq->wb_bytes
+				- pgbase, bytes);
+	}
+
+	/* Set the head request's range to cover the former page group */
+	head->wb_pgbase = pgbase;
+	head->wb_bytes = bytes;
+	head->wb_offset = off;
+
+	/* Now that all requests are locked, make sure they aren't on any list.
+	 * Commit list removal accounting is done after locks are dropped */
+	subreq = head;
+	do {
+		nfs_clear_request_commit(cinfo, subreq);
+		subreq = subreq->wb_this_page;
+	} while (subreq != head);
+
+	/* unlink subrequests from head, destroy them later */
+	if (head->wb_this_page != head) {
+		/* destroy list will be terminated by head */
+		destroy_list = head->wb_this_page;
+		head->wb_this_page = head;
+	}
+
+	nfs_destroy_unlinked_subrequests(destroy_list, head, inode);
+}
+
+/*
+ * nfs_lock_and_join_requests - join all subreqs to the head req
+ * @page: the page used to lookup the "page group" of nfs_page structures
+ *
+ * This function joins all sub requests to the head request by first
+ * locking all requests in the group, cancelling any pending operations
+ * and finally updating the head request to cover the whole range covered by
+ * the (former) group.  All subrequests are removed from any write or commit
+ * lists, unlinked from the group and destroyed.
+ *
+ * Returns a locked, referenced pointer to the head request - which after
+ * this call is guaranteed to be the only request associated with the page.
+ * Returns NULL if no requests are found for @page, or a ERR_PTR if an
+ * error was encountered.
+ */
+static struct nfs_page *
+nfs_lock_and_join_requests(struct page *page)
+{
+	struct inode *inode = page_file_mapping(page)->host;
+	struct nfs_page *head;
+	struct nfs_commit_info cinfo;
+	int ret;
+
+	nfs_init_cinfo_from_inode(&cinfo, inode);
+	/*
+	 * A reference is taken only on the head request which acts as a
+	 * reference to the whole page group - the group will not be destroyed
+	 * until the head reference is released.
+	 */
+	head = nfs_find_and_lock_page_request(page);
+	if (IS_ERR_OR_NULL(head))
+		return head;
+
+	/* lock each request in the page group */
+	ret = nfs_page_group_lock_subrequests(head);
+	if (ret < 0) {
+		nfs_unlock_and_release_request(head);
+		return ERR_PTR(ret);
+	}
+
+	nfs_join_page_group(head, &cinfo, inode);
+
+	return head;
+}
+
+static void nfs_write_error(struct nfs_page *req, int error)
+{
+	trace_nfs_write_error(req, error);
+	nfs_mapping_set_error(req->wb_page, error);
+	nfs_inode_remove_request(req);
+	nfs_end_page_writeback(req);
+	nfs_release_request(req);
+}
+
+/*
+ * Find an associated nfs write request, and prepare to flush it out
+ * May return an error if the user signalled nfs_wait_on_request().
+ */
+static int nfs_page_async_flush(struct nfs_pageio_descriptor *pgio,
+				struct page *page)
+{
+	struct nfs_page *req;
+	int ret = 0;
+
+	req = nfs_lock_and_join_requests(page);
+	if (!req)
+		goto out;
+	ret = PTR_ERR(req);
+	if (IS_ERR(req))
+		goto out;
+
+	nfs_set_page_writeback(page);
+	WARN_ON_ONCE(test_bit(PG_CLEAN, &req->wb_flags));
+
+	/* If there is a fatal error that covers this write, just exit */
+	ret = pgio->pg_error;
+	if (nfs_error_is_fatal_on_server(ret))
+		goto out_launder;
+
+	ret = 0;
+	if (!nfs_pageio_add_request(pgio, req)) {
+		ret = pgio->pg_error;
+		/*
+		 * Remove the problematic req upon fatal errors on the server
+		 */
+		if (nfs_error_is_fatal(ret)) {
+			if (nfs_error_is_fatal_on_server(ret))
+				goto out_launder;
+		} else
+			ret = -EAGAIN;
+		nfs_redirty_request(req);
+		pgio->pg_error = 0;
+	} else
+		nfs_add_stats(page_file_mapping(page)->host,
+				NFSIOS_WRITEPAGES, 1);
+out:
+	return ret;
+out_launder:
+	nfs_write_error(req, ret);
+	return 0;
+}
+
+static int nfs_do_writepage(struct page *page, struct writeback_control *wbc,
+			    struct nfs_pageio_descriptor *pgio)
+{
+	int ret;
+
+	nfs_pageio_cond_complete(pgio, page_index(page));
+	ret = nfs_page_async_flush(pgio, page);
+	if (ret == -EAGAIN) {
+		redirty_page_for_writepage(wbc, page);
+		ret = AOP_WRITEPAGE_ACTIVATE;
+	}
+	return ret;
+}
+
+/*
+ * Write an mmapped page to the server.
+ */
+static int nfs_writepage_locked(struct page *page,
+				struct writeback_control *wbc)
+{
+	struct nfs_pageio_descriptor pgio;
+	struct inode *inode = page_file_mapping(page)->host;
+	int err;
+
+	nfs_inc_stats(inode, NFSIOS_VFSWRITEPAGE);
+	nfs_pageio_init_write(&pgio, inode, 0,
+				false, &nfs_async_write_completion_ops);
+	err = nfs_do_writepage(page, wbc, &pgio);
+	pgio.pg_error = 0;
+	nfs_pageio_complete(&pgio);
+	return err;
+}
+
+int nfs_writepage(struct page *page, struct writeback_control *wbc)
+{
+	int ret;
+
+	ret = nfs_writepage_locked(page, wbc);
+	if (ret != AOP_WRITEPAGE_ACTIVATE)
+		unlock_page(page);
+	return ret;
+}
+
+static int nfs_writepages_callback(struct page *page, struct writeback_control *wbc, void *data)
+{
+	int ret;
+
+	ret = nfs_do_writepage(page, wbc, data);
+	if (ret != AOP_WRITEPAGE_ACTIVATE)
+		unlock_page(page);
+	return ret;
+}
+
+static void nfs_io_completion_commit(void *inode)
+{
+	nfs_commit_inode(inode, 0);
+}
+
+int nfs_writepages(struct address_space *mapping, struct writeback_control *wbc)
+{
+	struct inode *inode = mapping->host;
+	struct nfs_pageio_descriptor pgio;
+	struct nfs_io_completion *ioc;
+	int err;
+
+	nfs_inc_stats(inode, NFSIOS_VFSWRITEPAGES);
+
+	ioc = nfs_io_completion_alloc(GFP_KERNEL);
+	if (ioc)
+		nfs_io_completion_init(ioc, nfs_io_completion_commit, inode);
+
+	nfs_pageio_init_write(&pgio, inode, wb_priority(wbc), false,
+				&nfs_async_write_completion_ops);
+	pgio.pg_io_completion = ioc;
+	err = write_cache_pages(mapping, wbc, nfs_writepages_callback, &pgio);
+	pgio.pg_error = 0;
+	nfs_pageio_complete(&pgio);
+	nfs_io_completion_put(ioc);
+
+	if (err < 0)
+		goto out_err;
+	return 0;
+out_err:
+	return err;
+}
+
+/*
+ * Insert a write request into an inode
+ */
+static void nfs_inode_add_request(struct inode *inode, struct nfs_page *req)
+{
+	struct address_space *mapping = page_file_mapping(req->wb_page);
+	struct nfs_inode *nfsi = NFS_I(inode);
+
+	WARN_ON_ONCE(req->wb_this_page != req);
+
+	/* Lock the request! */
+	nfs_lock_request(req);
+
+	/*
+	 * Swap-space should not get truncated. Hence no need to plug the race
+	 * with invalidate/truncate.
+	 */
+	spin_lock(&mapping->private_lock);
+	if (!nfs_have_writebacks(inode) &&
+	    NFS_PROTO(inode)->have_delegation(inode, FMODE_WRITE))
+		inode_inc_iversion_raw(inode);
+	if (likely(!PageSwapCache(req->wb_page))) {
+		set_bit(PG_MAPPED, &req->wb_flags);
+		SetPagePrivate(req->wb_page);
+		set_page_private(req->wb_page, (unsigned long)req);
+	}
+	spin_unlock(&mapping->private_lock);
+	atomic_long_inc(&nfsi->nrequests);
+	/* this a head request for a page group - mark it as having an
+	 * extra reference so sub groups can follow suit.
+	 * This flag also informs pgio layer when to bump nrequests when
+	 * adding subrequests. */
+	WARN_ON(test_and_set_bit(PG_INODE_REF, &req->wb_flags));
+	kref_get(&req->wb_kref);
+}
+
+/*
+ * Remove a write request from an inode
+ */
+static void nfs_inode_remove_request(struct nfs_page *req)
+{
+	struct address_space *mapping = page_file_mapping(req->wb_page);
+	struct inode *inode = mapping->host;
+	struct nfs_inode *nfsi = NFS_I(inode);
+	struct nfs_page *head;
+
+	if (nfs_page_group_sync_on_bit(req, PG_REMOVE)) {
+		head = req->wb_head;
+
+		spin_lock(&mapping->private_lock);
+		if (likely(head->wb_page && !PageSwapCache(head->wb_page))) {
+			set_page_private(head->wb_page, 0);
+			ClearPagePrivate(head->wb_page);
+			clear_bit(PG_MAPPED, &head->wb_flags);
+		}
+		spin_unlock(&mapping->private_lock);
+	}
+
+	if (test_and_clear_bit(PG_INODE_REF, &req->wb_flags)) {
+		nfs_release_request(req);
+		atomic_long_dec(&nfsi->nrequests);
+	}
+}
+
+static void
+nfs_mark_request_dirty(struct nfs_page *req)
+{
+	if (req->wb_page)
+		__set_page_dirty_nobuffers(req->wb_page);
+}
+
+/*
+ * nfs_page_search_commits_for_head_request_locked
+ *
+ * Search through commit lists on @inode for the head request for @page.
+ * Must be called while holding the inode (which is cinfo) lock.
+ *
+ * Returns the head request if found, or NULL if not found.
+ */
+static struct nfs_page *
+nfs_page_search_commits_for_head_request_locked(struct nfs_inode *nfsi,
+						struct page *page)
+{
+	struct nfs_page *freq, *t;
+	struct nfs_commit_info cinfo;
+	struct inode *inode = &nfsi->vfs_inode;
+
+	nfs_init_cinfo_from_inode(&cinfo, inode);
+
+	/* search through pnfs commit lists */
+	freq = pnfs_search_commit_reqs(inode, &cinfo, page);
+	if (freq)
+		return freq->wb_head;
+
+	/* Linearly search the commit list for the correct request */
+	list_for_each_entry_safe(freq, t, &cinfo.mds->list, wb_list) {
+		if (freq->wb_page == page)
+			return freq->wb_head;
+	}
+
+	return NULL;
+}
+
+/**
+ * nfs_request_add_commit_list_locked - add request to a commit list
+ * @req: pointer to a struct nfs_page
+ * @dst: commit list head
+ * @cinfo: holds list lock and accounting info
+ *
+ * This sets the PG_CLEAN bit, updates the cinfo count of
+ * number of outstanding requests requiring a commit as well as
+ * the MM page stats.
+ *
+ * The caller must hold NFS_I(cinfo->inode)->commit_mutex, and the
+ * nfs_page lock.
+ */
+void
+nfs_request_add_commit_list_locked(struct nfs_page *req, struct list_head *dst,
+			    struct nfs_commit_info *cinfo)
+{
+	set_bit(PG_CLEAN, &req->wb_flags);
+	nfs_list_add_request(req, dst);
+	atomic_long_inc(&cinfo->mds->ncommit);
+}
+EXPORT_SYMBOL_GPL(nfs_request_add_commit_list_locked);
+
+/**
+ * nfs_request_add_commit_list - add request to a commit list
+ * @req: pointer to a struct nfs_page
+ * @cinfo: holds list lock and accounting info
+ *
+ * This sets the PG_CLEAN bit, updates the cinfo count of
+ * number of outstanding requests requiring a commit as well as
+ * the MM page stats.
+ *
+ * The caller must _not_ hold the cinfo->lock, but must be
+ * holding the nfs_page lock.
+ */
+void
+nfs_request_add_commit_list(struct nfs_page *req, struct nfs_commit_info *cinfo)
+{
+	mutex_lock(&NFS_I(cinfo->inode)->commit_mutex);
+	nfs_request_add_commit_list_locked(req, &cinfo->mds->list, cinfo);
+	mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);
+	if (req->wb_page)
+		nfs_mark_page_unstable(req->wb_page, cinfo);
+}
+EXPORT_SYMBOL_GPL(nfs_request_add_commit_list);
+
+/**
+ * nfs_request_remove_commit_list - Remove request from a commit list
+ * @req: pointer to a nfs_page
+ * @cinfo: holds list lock and accounting info
+ *
+ * This clears the PG_CLEAN bit, and updates the cinfo's count of
+ * number of outstanding requests requiring a commit
+ * It does not update the MM page stats.
+ *
+ * The caller _must_ hold the cinfo->lock and the nfs_page lock.
+ */
+void
+nfs_request_remove_commit_list(struct nfs_page *req,
+			       struct nfs_commit_info *cinfo)
+{
+	if (!test_and_clear_bit(PG_CLEAN, &(req)->wb_flags))
+		return;
+	nfs_list_remove_request(req);
+	atomic_long_dec(&cinfo->mds->ncommit);
+}
+EXPORT_SYMBOL_GPL(nfs_request_remove_commit_list);
+
+static void nfs_init_cinfo_from_inode(struct nfs_commit_info *cinfo,
+				      struct inode *inode)
+{
+	cinfo->inode = inode;
+	cinfo->mds = &NFS_I(inode)->commit_info;
+	cinfo->ds = pnfs_get_ds_info(inode);
+	cinfo->dreq = NULL;
+	cinfo->completion_ops = &nfs_commit_completion_ops;
+}
+
+void nfs_init_cinfo(struct nfs_commit_info *cinfo,
+		    struct inode *inode,
+		    struct nfs_direct_req *dreq)
+{
+	if (dreq)
+		nfs_init_cinfo_from_dreq(cinfo, dreq);
+	else
+		nfs_init_cinfo_from_inode(cinfo, inode);
+}
+EXPORT_SYMBOL_GPL(nfs_init_cinfo);
+
+/*
+ * Add a request to the inode's commit list.
+ */
+void
+nfs_mark_request_commit(struct nfs_page *req, struct pnfs_layout_segment *lseg,
+			struct nfs_commit_info *cinfo, u32 ds_commit_idx)
+{
+	if (pnfs_mark_request_commit(req, lseg, cinfo, ds_commit_idx))
+		return;
+	nfs_request_add_commit_list(req, cinfo);
+}
+
+static void
+nfs_clear_page_commit(struct page *page)
+{
+	dec_node_page_state(page, NR_WRITEBACK);
+	dec_wb_stat(&inode_to_bdi(page_file_mapping(page)->host)->wb,
+		    WB_WRITEBACK);
+}
+
+/* Called holding the request lock on @req */
+static void nfs_clear_request_commit(struct nfs_commit_info *cinfo,
+				     struct nfs_page *req)
+{
+	if (test_bit(PG_CLEAN, &req->wb_flags)) {
+		struct nfs_open_context *ctx = nfs_req_openctx(req);
+		struct inode *inode = d_inode(ctx->dentry);
+
+		mutex_lock(&NFS_I(inode)->commit_mutex);
+		if (!pnfs_clear_request_commit(req, cinfo)) {
+			nfs_request_remove_commit_list(req, cinfo);
+		}
+		mutex_unlock(&NFS_I(inode)->commit_mutex);
+		nfs_clear_page_commit(req->wb_page);
+	}
+}
+
+int nfs_write_need_commit(struct nfs_pgio_header *hdr)
+{
+	if (hdr->verf.committed == NFS_DATA_SYNC)
+		return hdr->lseg == NULL;
+	return hdr->verf.committed != NFS_FILE_SYNC;
+}
+
+static void nfs_async_write_init(struct nfs_pgio_header *hdr)
+{
+	nfs_io_completion_get(hdr->io_completion);
+}
+
+static void nfs_write_completion(struct nfs_pgio_header *hdr)
+{
+	struct nfs_commit_info cinfo;
+	unsigned long bytes = 0;
+
+	if (test_bit(NFS_IOHDR_REDO, &hdr->flags))
+		goto out;
+	nfs_init_cinfo_from_inode(&cinfo, hdr->inode);
+	while (!list_empty(&hdr->pages)) {
+		struct nfs_page *req = nfs_list_entry(hdr->pages.next);
+
+		bytes += req->wb_bytes;
+		nfs_list_remove_request(req);
+		if (test_bit(NFS_IOHDR_ERROR, &hdr->flags) &&
+		    (hdr->good_bytes < bytes)) {
+			trace_nfs_comp_error(req, hdr->error);
+			nfs_mapping_set_error(req->wb_page, hdr->error);
+			goto remove_req;
+		}
+		if (nfs_write_need_commit(hdr)) {
+			/* Reset wb_nio, since the write was successful. */
+			req->wb_nio = 0;
+			memcpy(&req->wb_verf, &hdr->verf.verifier, sizeof(req->wb_verf));
+			nfs_mark_request_commit(req, hdr->lseg, &cinfo,
+				hdr->pgio_mirror_idx);
+			goto next;
+		}
+remove_req:
+		nfs_inode_remove_request(req);
+next:
+		nfs_end_page_writeback(req);
+		nfs_release_request(req);
+	}
+out:
+	nfs_io_completion_put(hdr->io_completion);
+	hdr->release(hdr);
+}
+
+unsigned long
+nfs_reqs_to_commit(struct nfs_commit_info *cinfo)
+{
+	return atomic_long_read(&cinfo->mds->ncommit);
+}
+
+/* NFS_I(cinfo->inode)->commit_mutex held by caller */
+int
+nfs_scan_commit_list(struct list_head *src, struct list_head *dst,
+		     struct nfs_commit_info *cinfo, int max)
+{
+	struct nfs_page *req, *tmp;
+	int ret = 0;
+
+	list_for_each_entry_safe(req, tmp, src, wb_list) {
+		kref_get(&req->wb_kref);
+		if (!nfs_lock_request(req)) {
+			nfs_release_request(req);
+			continue;
+		}
+		nfs_request_remove_commit_list(req, cinfo);
+		clear_bit(PG_COMMIT_TO_DS, &req->wb_flags);
+		nfs_list_add_request(req, dst);
+		ret++;
+		if ((ret == max) && !cinfo->dreq)
+			break;
+		cond_resched();
+	}
+	return ret;
+}
+EXPORT_SYMBOL_GPL(nfs_scan_commit_list);
+
+/*
+ * nfs_scan_commit - Scan an inode for commit requests
+ * @inode: NFS inode to scan
+ * @dst: mds destination list
+ * @cinfo: mds and ds lists of reqs ready to commit
+ *
+ * Moves requests from the inode's 'commit' request list.
+ * The requests are *not* checked to ensure that they form a contiguous set.
+ */
+int
+nfs_scan_commit(struct inode *inode, struct list_head *dst,
+		struct nfs_commit_info *cinfo)
+{
+	int ret = 0;
+
+	if (!atomic_long_read(&cinfo->mds->ncommit))
+		return 0;
+	mutex_lock(&NFS_I(cinfo->inode)->commit_mutex);
+	if (atomic_long_read(&cinfo->mds->ncommit) > 0) {
+		const int max = INT_MAX;
+
+		ret = nfs_scan_commit_list(&cinfo->mds->list, dst,
+					   cinfo, max);
+		ret += pnfs_scan_commit_lists(inode, cinfo, max - ret);
+	}
+	mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);
+	return ret;
+}
+
+/*
+ * Search for an existing write request, and attempt to update
+ * it to reflect a new dirty region on a given page.
+ *
+ * If the attempt fails, then the existing request is flushed out
+ * to disk.
+ */
+static struct nfs_page *nfs_try_to_update_request(struct inode *inode,
+		struct page *page,
+		unsigned int offset,
+		unsigned int bytes)
+{
+	struct nfs_page *req;
+	unsigned int rqend;
+	unsigned int end;
+	int error;
+
+	end = offset + bytes;
+
+	req = nfs_lock_and_join_requests(page);
+	if (IS_ERR_OR_NULL(req))
+		return req;
+
+	rqend = req->wb_offset + req->wb_bytes;
+	/*
+	 * Tell the caller to flush out the request if
+	 * the offsets are non-contiguous.
+	 * Note: nfs_flush_incompatible() will already
+	 * have flushed out requests having wrong owners.
+	 */
+	if (offset > rqend || end < req->wb_offset)
+		goto out_flushme;
+
+	/* Okay, the request matches. Update the region */
+	if (offset < req->wb_offset) {
+		req->wb_offset = offset;
+		req->wb_pgbase = offset;
+	}
+	if (end > rqend)
+		req->wb_bytes = end - req->wb_offset;
+	else
+		req->wb_bytes = rqend - req->wb_offset;
+	req->wb_nio = 0;
+	return req;
+out_flushme:
+	/*
+	 * Note: we mark the request dirty here because
+	 * nfs_lock_and_join_requests() cannot preserve
+	 * commit flags, so we have to replay the write.
+	 */
+	nfs_mark_request_dirty(req);
+	nfs_unlock_and_release_request(req);
+	error = nfs_wb_page(inode, page);
+	return (error < 0) ? ERR_PTR(error) : NULL;
+}
+
+/*
+ * Try to update an existing write request, or create one if there is none.
+ *
+ * Note: Should always be called with the Page Lock held to prevent races
+ * if we have to add a new request. Also assumes that the caller has
+ * already called nfs_flush_incompatible() if necessary.
+ */
+static struct nfs_page * nfs_setup_write_request(struct nfs_open_context* ctx,
+		struct page *page, unsigned int offset, unsigned int bytes)
+{
+	struct inode *inode = page_file_mapping(page)->host;
+	struct nfs_page	*req;
+
+	req = nfs_try_to_update_request(inode, page, offset, bytes);
+	if (req != NULL)
+		goto out;
+	req = nfs_create_request(ctx, page, offset, bytes);
+	if (IS_ERR(req))
+		goto out;
+	nfs_inode_add_request(inode, req);
+out:
+	return req;
+}
+
+static int nfs_writepage_setup(struct nfs_open_context *ctx, struct page *page,
+		unsigned int offset, unsigned int count)
+{
+	struct nfs_page	*req;
+
+	req = nfs_setup_write_request(ctx, page, offset, count);
+	if (IS_ERR(req))
+		return PTR_ERR(req);
+	/* Update file length */
+	nfs_grow_file(page, offset, count);
+	nfs_mark_uptodate(req);
+	nfs_mark_request_dirty(req);
+	nfs_unlock_and_release_request(req);
+	return 0;
+}
+
+int nfs_flush_incompatible(struct file *file, struct page *page)
+{
+	struct nfs_open_context *ctx = nfs_file_open_context(file);
+	struct nfs_lock_context *l_ctx;
+	struct file_lock_context *flctx = file_inode(file)->i_flctx;
+	struct nfs_page	*req;
+	int do_flush, status;
+	/*
+	 * Look for a request corresponding to this page. If there
+	 * is one, and it belongs to another file, we flush it out
+	 * before we try to copy anything into the page. Do this
+	 * due to the lack of an ACCESS-type call in NFSv2.
+	 * Also do the same if we find a request from an existing
+	 * dropped page.
+	 */
+	do {
+		req = nfs_page_find_head_request(page);
+		if (req == NULL)
+			return 0;
+		l_ctx = req->wb_lock_context;
+		do_flush = req->wb_page != page ||
+			!nfs_match_open_context(nfs_req_openctx(req), ctx);
+		if (l_ctx && flctx &&
+		    !(list_empty_careful(&flctx->flc_posix) &&
+		      list_empty_careful(&flctx->flc_flock))) {
+			do_flush |= l_ctx->lockowner != current->files;
+		}
+		nfs_release_request(req);
+		if (!do_flush)
+			return 0;
+		status = nfs_wb_page(page_file_mapping(page)->host, page);
+	} while (status == 0);
+	return status;
+}
+
+/*
+ * Avoid buffered writes when a open context credential's key would
+ * expire soon.
+ *
+ * Returns -EACCES if the key will expire within RPC_KEY_EXPIRE_FAIL.
+ *
+ * Return 0 and set a credential flag which triggers the inode to flush
+ * and performs  NFS_FILE_SYNC writes if the key will expired within
+ * RPC_KEY_EXPIRE_TIMEO.
+ */
+int
+nfs_key_timeout_notify(struct file *filp, struct inode *inode)
+{
+	struct nfs_open_context *ctx = nfs_file_open_context(filp);
+
+	if (nfs_ctx_key_to_expire(ctx, inode) &&
+	    !ctx->ll_cred)
+		/* Already expired! */
+		return -EACCES;
+	return 0;
+}
+
+/*
+ * Test if the open context credential key is marked to expire soon.
+ */
+bool nfs_ctx_key_to_expire(struct nfs_open_context *ctx, struct inode *inode)
+{
+	struct rpc_auth *auth = NFS_SERVER(inode)->client->cl_auth;
+	struct rpc_cred *cred = ctx->ll_cred;
+	struct auth_cred acred = {
+		.cred = ctx->cred,
+	};
+
+	if (cred && !cred->cr_ops->crmatch(&acred, cred, 0)) {
+		put_rpccred(cred);
+		ctx->ll_cred = NULL;
+		cred = NULL;
+	}
+	if (!cred)
+		cred = auth->au_ops->lookup_cred(auth, &acred, 0);
+	if (!cred || IS_ERR(cred))
+		return true;
+	ctx->ll_cred = cred;
+	return !!(cred->cr_ops->crkey_timeout &&
+		  cred->cr_ops->crkey_timeout(cred));
+}
+
+/*
+ * If the page cache is marked as unsafe or invalid, then we can't rely on
+ * the PageUptodate() flag. In this case, we will need to turn off
+ * write optimisations that depend on the page contents being correct.
+ */
+static bool nfs_write_pageuptodate(struct page *page, struct inode *inode)
+{
+	struct nfs_inode *nfsi = NFS_I(inode);
+
+	if (nfs_have_delegated_attributes(inode))
+		goto out;
+	if (nfsi->cache_validity & NFS_INO_REVAL_PAGECACHE)
+		return false;
+	smp_rmb();
+	if (test_bit(NFS_INO_INVALIDATING, &nfsi->flags))
+		return false;
+out:
+	if (nfsi->cache_validity & NFS_INO_INVALID_DATA)
+		return false;
+	return PageUptodate(page) != 0;
+}
+
+static bool
+is_whole_file_wrlock(struct file_lock *fl)
+{
+	return fl->fl_start == 0 && fl->fl_end == OFFSET_MAX &&
+			fl->fl_type == F_WRLCK;
+}
+
+/* If we know the page is up to date, and we're not using byte range locks (or
+ * if we have the whole file locked for writing), it may be more efficient to
+ * extend the write to cover the entire page in order to avoid fragmentation
+ * inefficiencies.
+ *
+ * If the file is opened for synchronous writes then we can just skip the rest
+ * of the checks.
+ */
+static int nfs_can_extend_write(struct file *file, struct page *page, struct inode *inode)
+{
+	int ret;
+	struct file_lock_context *flctx = inode->i_flctx;
+	struct file_lock *fl;
+
+	if (file->f_flags & O_DSYNC)
+		return 0;
+	if (!nfs_write_pageuptodate(page, inode))
+		return 0;
+	if (NFS_PROTO(inode)->have_delegation(inode, FMODE_WRITE))
+		return 1;
+	if (!flctx || (list_empty_careful(&flctx->flc_flock) &&
+		       list_empty_careful(&flctx->flc_posix)))
+		return 1;
+
+	/* Check to see if there are whole file write locks */
+	ret = 0;
+	spin_lock(&flctx->flc_lock);
+	if (!list_empty(&flctx->flc_posix)) {
+		fl = list_first_entry(&flctx->flc_posix, struct file_lock,
+					fl_list);
+		if (is_whole_file_wrlock(fl))
+			ret = 1;
+	} else if (!list_empty(&flctx->flc_flock)) {
+		fl = list_first_entry(&flctx->flc_flock, struct file_lock,
+					fl_list);
+		if (fl->fl_type == F_WRLCK)
+			ret = 1;
+	}
+	spin_unlock(&flctx->flc_lock);
+	return ret;
+}
+
+/*
+ * Update and possibly write a cached page of an NFS file.
+ *
+ * XXX: Keep an eye on generic_file_read to make sure it doesn't do bad
+ * things with a page scheduled for an RPC call (e.g. invalidate it).
+ */
+int nfs_updatepage(struct file *file, struct page *page,
+		unsigned int offset, unsigned int count)
+{
+	struct nfs_open_context *ctx = nfs_file_open_context(file);
+	struct address_space *mapping = page_file_mapping(page);
+	struct inode	*inode = mapping->host;
+	int		status = 0;
+
+	nfs_inc_stats(inode, NFSIOS_VFSUPDATEPAGE);
+
+	dprintk("NFS:       nfs_updatepage(%pD2 %d@%lld)\n",
+		file, count, (long long)(page_file_offset(page) + offset));
+
+	if (!count)
+		goto out;
+
+	if (nfs_can_extend_write(file, page, inode)) {
+		count = max(count + offset, nfs_page_length(page));
+		offset = 0;
+	}
+
+	status = nfs_writepage_setup(ctx, page, offset, count);
+	if (status < 0)
+		nfs_set_pageerror(mapping);
+	else
+		__set_page_dirty_nobuffers(page);
+out:
+	dprintk("NFS:       nfs_updatepage returns %d (isize %lld)\n",
+			status, (long long)i_size_read(inode));
+	return status;
+}
+
+static int flush_task_priority(int how)
+{
+	switch (how & (FLUSH_HIGHPRI|FLUSH_LOWPRI)) {
+		case FLUSH_HIGHPRI:
+			return RPC_PRIORITY_HIGH;
+		case FLUSH_LOWPRI:
+			return RPC_PRIORITY_LOW;
+	}
+	return RPC_PRIORITY_NORMAL;
+}
+
+static void nfs_initiate_write(struct nfs_pgio_header *hdr,
+			       struct rpc_message *msg,
+			       const struct nfs_rpc_ops *rpc_ops,
+			       struct rpc_task_setup *task_setup_data, int how)
+{
+	int priority = flush_task_priority(how);
+
+	task_setup_data->priority = priority;
+	rpc_ops->write_setup(hdr, msg, &task_setup_data->rpc_client);
+	trace_nfs_initiate_write(hdr);
+}
+
+/* If a nfs_flush_* function fails, it should remove reqs from @head and
+ * call this on each, which will prepare them to be retried on next
+ * writeback using standard nfs.
+ */
+static void nfs_redirty_request(struct nfs_page *req)
+{
+	/* Bump the transmission count */
+	req->wb_nio++;
+	nfs_mark_request_dirty(req);
+	set_bit(NFS_CONTEXT_RESEND_WRITES, &nfs_req_openctx(req)->flags);
+	nfs_end_page_writeback(req);
+	nfs_release_request(req);
+}
+
+static void nfs_async_write_error(struct list_head *head, int error)
+{
+	struct nfs_page	*req;
+
+	while (!list_empty(head)) {
+		req = nfs_list_entry(head->next);
+		nfs_list_remove_request(req);
+		if (nfs_error_is_fatal_on_server(error))
+			nfs_write_error(req, error);
+		else
+			nfs_redirty_request(req);
+	}
+}
+
+static void nfs_async_write_reschedule_io(struct nfs_pgio_header *hdr)
+{
+	nfs_async_write_error(&hdr->pages, 0);
+	filemap_fdatawrite_range(hdr->inode->i_mapping, hdr->args.offset,
+			hdr->args.offset + hdr->args.count - 1);
+}
+
+static const struct nfs_pgio_completion_ops nfs_async_write_completion_ops = {
+	.init_hdr = nfs_async_write_init,
+	.error_cleanup = nfs_async_write_error,
+	.completion = nfs_write_completion,
+	.reschedule_io = nfs_async_write_reschedule_io,
+};
+
+void nfs_pageio_init_write(struct nfs_pageio_descriptor *pgio,
+			       struct inode *inode, int ioflags, bool force_mds,
+			       const struct nfs_pgio_completion_ops *compl_ops)
+{
+	struct nfs_server *server = NFS_SERVER(inode);
+	const struct nfs_pageio_ops *pg_ops = &nfs_pgio_rw_ops;
+
+#ifdef CONFIG_NFS_V4_1
+	if (server->pnfs_curr_ld && !force_mds)
+		pg_ops = server->pnfs_curr_ld->pg_write_ops;
+#endif
+	nfs_pageio_init(pgio, inode, pg_ops, compl_ops, &nfs_rw_write_ops,
+			server->wsize, ioflags);
+}
+EXPORT_SYMBOL_GPL(nfs_pageio_init_write);
+
+void nfs_pageio_reset_write_mds(struct nfs_pageio_descriptor *pgio)
+{
+	struct nfs_pgio_mirror *mirror;
+
+	if (pgio->pg_ops && pgio->pg_ops->pg_cleanup)
+		pgio->pg_ops->pg_cleanup(pgio);
+
+	pgio->pg_ops = &nfs_pgio_rw_ops;
+
+	nfs_pageio_stop_mirroring(pgio);
+
+	mirror = &pgio->pg_mirrors[0];
+	mirror->pg_bsize = NFS_SERVER(pgio->pg_inode)->wsize;
+}
+EXPORT_SYMBOL_GPL(nfs_pageio_reset_write_mds);
+
+
+void nfs_commit_prepare(struct rpc_task *task, void *calldata)
+{
+	struct nfs_commit_data *data = calldata;
+
+	NFS_PROTO(data->inode)->commit_rpc_prepare(task, data);
+}
+
+/*
+ * Special version of should_remove_suid() that ignores capabilities.
+ */
+static int nfs_should_remove_suid(const struct inode *inode)
+{
+	umode_t mode = inode->i_mode;
+	int kill = 0;
+
+	/* suid always must be killed */
+	if (unlikely(mode & S_ISUID))
+		kill = ATTR_KILL_SUID;
+
+	/*
+	 * sgid without any exec bits is just a mandatory locking mark; leave
+	 * it alone.  If some exec bits are set, it's a real sgid; kill it.
+	 */
+	if (unlikely((mode & S_ISGID) && (mode & S_IXGRP)))
+		kill |= ATTR_KILL_SGID;
+
+	if (unlikely(kill && S_ISREG(mode)))
+		return kill;
+
+	return 0;
+}
+
+static void nfs_writeback_check_extend(struct nfs_pgio_header *hdr,
+		struct nfs_fattr *fattr)
+{
+	struct nfs_pgio_args *argp = &hdr->args;
+	struct nfs_pgio_res *resp = &hdr->res;
+	u64 size = argp->offset + resp->count;
+
+	if (!(fattr->valid & NFS_ATTR_FATTR_SIZE))
+		fattr->size = size;
+	if (nfs_size_to_loff_t(fattr->size) < i_size_read(hdr->inode)) {
+		fattr->valid &= ~NFS_ATTR_FATTR_SIZE;
+		return;
+	}
+	if (size != fattr->size)
+		return;
+	/* Set attribute barrier */
+	nfs_fattr_set_barrier(fattr);
+	/* ...and update size */
+	fattr->valid |= NFS_ATTR_FATTR_SIZE;
+}
+
+void nfs_writeback_update_inode(struct nfs_pgio_header *hdr)
+{
+	struct nfs_fattr *fattr = &hdr->fattr;
+	struct inode *inode = hdr->inode;
+
+	spin_lock(&inode->i_lock);
+	nfs_writeback_check_extend(hdr, fattr);
+	nfs_post_op_update_inode_force_wcc_locked(inode, fattr);
+	spin_unlock(&inode->i_lock);
+}
+EXPORT_SYMBOL_GPL(nfs_writeback_update_inode);
+
+/*
+ * This function is called when the WRITE call is complete.
+ */
+static int nfs_writeback_done(struct rpc_task *task,
+			      struct nfs_pgio_header *hdr,
+			      struct inode *inode)
+{
+	int status;
+
+	/*
+	 * ->write_done will attempt to use post-op attributes to detect
+	 * conflicting writes by other clients.  A strict interpretation
+	 * of close-to-open would allow us to continue caching even if
+	 * another writer had changed the file, but some applications
+	 * depend on tighter cache coherency when writing.
+	 */
+	status = NFS_PROTO(inode)->write_done(task, hdr);
+	if (status != 0)
+		return status;
+
+	nfs_add_stats(inode, NFSIOS_SERVERWRITTENBYTES, hdr->res.count);
+	trace_nfs_writeback_done(task, hdr);
+
+	if (hdr->res.verf->committed < hdr->args.stable &&
+	    task->tk_status >= 0) {
+		/* We tried a write call, but the server did not
+		 * commit data to stable storage even though we
+		 * requested it.
+		 * Note: There is a known bug in Tru64 < 5.0 in which
+		 *	 the server reports NFS_DATA_SYNC, but performs
+		 *	 NFS_FILE_SYNC. We therefore implement this checking
+		 *	 as a dprintk() in order to avoid filling syslog.
+		 */
+		static unsigned long    complain;
+
+		/* Note this will print the MDS for a DS write */
+		if (time_before(complain, jiffies)) {
+			dprintk("NFS:       faulty NFS server %s:"
+				" (committed = %d) != (stable = %d)\n",
+				NFS_SERVER(inode)->nfs_client->cl_hostname,
+				hdr->res.verf->committed, hdr->args.stable);
+			complain = jiffies + 300 * HZ;
+		}
+	}
+
+	/* Deal with the suid/sgid bit corner case */
+	if (nfs_should_remove_suid(inode)) {
+		spin_lock(&inode->i_lock);
+		NFS_I(inode)->cache_validity |= NFS_INO_INVALID_OTHER;
+		spin_unlock(&inode->i_lock);
+	}
+	return 0;
+}
+
+/*
+ * This function is called when the WRITE call is complete.
+ */
+static void nfs_writeback_result(struct rpc_task *task,
+				 struct nfs_pgio_header *hdr)
+{
+	struct nfs_pgio_args	*argp = &hdr->args;
+	struct nfs_pgio_res	*resp = &hdr->res;
+
+	if (resp->count < argp->count) {
+		static unsigned long    complain;
+
+		/* This a short write! */
+		nfs_inc_stats(hdr->inode, NFSIOS_SHORTWRITE);
+
+		/* Has the server at least made some progress? */
+		if (resp->count == 0) {
+			if (time_before(complain, jiffies)) {
+				printk(KERN_WARNING
+				       "NFS: Server wrote zero bytes, expected %u.\n",
+				       argp->count);
+				complain = jiffies + 300 * HZ;
+			}
+			nfs_set_pgio_error(hdr, -EIO, argp->offset);
+			task->tk_status = -EIO;
+			return;
+		}
+
+		/* For non rpc-based layout drivers, retry-through-MDS */
+		if (!task->tk_ops) {
+			hdr->pnfs_error = -EAGAIN;
+			return;
+		}
+
+		/* Was this an NFSv2 write or an NFSv3 stable write? */
+		if (resp->verf->committed != NFS_UNSTABLE) {
+			/* Resend from where the server left off */
+			hdr->mds_offset += resp->count;
+			argp->offset += resp->count;
+			argp->pgbase += resp->count;
+			argp->count -= resp->count;
+		} else {
+			/* Resend as a stable write in order to avoid
+			 * headaches in the case of a server crash.
+			 */
+			argp->stable = NFS_FILE_SYNC;
+		}
+		resp->count = 0;
+		resp->verf->committed = 0;
+		rpc_restart_call_prepare(task);
+	}
+}
+
+static int wait_on_commit(struct nfs_mds_commit_info *cinfo)
+{
+	return wait_var_event_killable(&cinfo->rpcs_out,
+				       !atomic_read(&cinfo->rpcs_out));
+}
+
+static void nfs_commit_begin(struct nfs_mds_commit_info *cinfo)
+{
+	atomic_inc(&cinfo->rpcs_out);
+}
+
+bool nfs_commit_end(struct nfs_mds_commit_info *cinfo)
+{
+	if (atomic_dec_and_test(&cinfo->rpcs_out)) {
+		wake_up_var(&cinfo->rpcs_out);
+		return true;
+	}
+	return false;
+}
+
+void nfs_commitdata_release(struct nfs_commit_data *data)
+{
+	put_nfs_open_context(data->context);
+	nfs_commit_free(data);
+}
+EXPORT_SYMBOL_GPL(nfs_commitdata_release);
+
+int nfs_initiate_commit(struct rpc_clnt *clnt, struct nfs_commit_data *data,
+			const struct nfs_rpc_ops *nfs_ops,
+			const struct rpc_call_ops *call_ops,
+			int how, int flags)
+{
+	struct rpc_task *task;
+	int priority = flush_task_priority(how);
+	struct rpc_message msg = {
+		.rpc_argp = &data->args,
+		.rpc_resp = &data->res,
+		.rpc_cred = data->cred,
+	};
+	struct rpc_task_setup task_setup_data = {
+		.task = &data->task,
+		.rpc_client = clnt,
+		.rpc_message = &msg,
+		.callback_ops = call_ops,
+		.callback_data = data,
+		.workqueue = nfsiod_workqueue,
+		.flags = RPC_TASK_ASYNC | flags,
+		.priority = priority,
+	};
+	/* Set up the initial task struct.  */
+	nfs_ops->commit_setup(data, &msg, &task_setup_data.rpc_client);
+	trace_nfs_initiate_commit(data);
+
+	dprintk("NFS: initiated commit call\n");
+
+	task = rpc_run_task(&task_setup_data);
+	if (IS_ERR(task))
+		return PTR_ERR(task);
+	if (how & FLUSH_SYNC)
+		rpc_wait_for_completion_task(task);
+	rpc_put_task(task);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nfs_initiate_commit);
+
+static loff_t nfs_get_lwb(struct list_head *head)
+{
+	loff_t lwb = 0;
+	struct nfs_page *req;
+
+	list_for_each_entry(req, head, wb_list)
+		if (lwb < (req_offset(req) + req->wb_bytes))
+			lwb = req_offset(req) + req->wb_bytes;
+
+	return lwb;
+}
+
+/*
+ * Set up the argument/result storage required for the RPC call.
+ */
+void nfs_init_commit(struct nfs_commit_data *data,
+		     struct list_head *head,
+		     struct pnfs_layout_segment *lseg,
+		     struct nfs_commit_info *cinfo)
+{
+	struct nfs_page *first;
+	struct nfs_open_context *ctx;
+	struct inode *inode;
+
+	/* Set up the RPC argument and reply structs
+	 * NB: take care not to mess about with data->commit et al. */
+
+	if (head)
+		list_splice_init(head, &data->pages);
+
+	first = nfs_list_entry(data->pages.next);
+	ctx = nfs_req_openctx(first);
+	inode = d_inode(ctx->dentry);
+
+	data->inode	  = inode;
+	data->cred	  = ctx->cred;
+	data->lseg	  = lseg; /* reference transferred */
+	/* only set lwb for pnfs commit */
+	if (lseg)
+		data->lwb = nfs_get_lwb(&data->pages);
+	data->mds_ops     = &nfs_commit_ops;
+	data->completion_ops = cinfo->completion_ops;
+	data->dreq	  = cinfo->dreq;
+
+	data->args.fh     = NFS_FH(data->inode);
+	/* Note: we always request a commit of the entire inode */
+	data->args.offset = 0;
+	data->args.count  = 0;
+	data->context     = get_nfs_open_context(ctx);
+	data->res.fattr   = &data->fattr;
+	data->res.verf    = &data->verf;
+	nfs_fattr_init(&data->fattr);
+	nfs_commit_begin(cinfo->mds);
+}
+EXPORT_SYMBOL_GPL(nfs_init_commit);
+
+void nfs_retry_commit(struct list_head *page_list,
+		      struct pnfs_layout_segment *lseg,
+		      struct nfs_commit_info *cinfo,
+		      u32 ds_commit_idx)
+{
+	struct nfs_page *req;
+
+	while (!list_empty(page_list)) {
+		req = nfs_list_entry(page_list->next);
+		nfs_list_remove_request(req);
+		nfs_mark_request_commit(req, lseg, cinfo, ds_commit_idx);
+		if (!cinfo->dreq)
+			nfs_clear_page_commit(req->wb_page);
+		nfs_unlock_and_release_request(req);
+	}
+}
+EXPORT_SYMBOL_GPL(nfs_retry_commit);
+
+static void
+nfs_commit_resched_write(struct nfs_commit_info *cinfo,
+		struct nfs_page *req)
+{
+	__set_page_dirty_nobuffers(req->wb_page);
+}
+
+/*
+ * Commit dirty pages
+ */
+static int
+nfs_commit_list(struct inode *inode, struct list_head *head, int how,
+		struct nfs_commit_info *cinfo)
+{
+	struct nfs_commit_data	*data;
+
+	/* another commit raced with us */
+	if (list_empty(head))
+		return 0;
+
+	data = nfs_commitdata_alloc();
+	if (!data) {
+		nfs_retry_commit(head, NULL, cinfo, -1);
+		return -ENOMEM;
+	}
+
+	/* Set up the argument struct */
+	nfs_init_commit(data, head, NULL, cinfo);
+	return nfs_initiate_commit(NFS_CLIENT(inode), data, NFS_PROTO(inode),
+				   data->mds_ops, how, RPC_TASK_CRED_NOREF);
+}
+
+/*
+ * COMMIT call returned
+ */
+static void nfs_commit_done(struct rpc_task *task, void *calldata)
+{
+	struct nfs_commit_data	*data = calldata;
+
+        dprintk("NFS: %5u nfs_commit_done (status %d)\n",
+                                task->tk_pid, task->tk_status);
+
+	/* Call the NFS version-specific code */
+	NFS_PROTO(data->inode)->commit_done(task, data);
+	trace_nfs_commit_done(task, data);
+}
+
+static void nfs_commit_release_pages(struct nfs_commit_data *data)
+{
+	const struct nfs_writeverf *verf = data->res.verf;
+	struct nfs_page	*req;
+	int status = data->task.tk_status;
+	struct nfs_commit_info cinfo;
+	struct nfs_server *nfss;
+
+	while (!list_empty(&data->pages)) {
+		req = nfs_list_entry(data->pages.next);
+		nfs_list_remove_request(req);
+		if (req->wb_page)
+			nfs_clear_page_commit(req->wb_page);
+
+		dprintk("NFS:       commit (%s/%llu %d@%lld)",
+			nfs_req_openctx(req)->dentry->d_sb->s_id,
+			(unsigned long long)NFS_FILEID(d_inode(nfs_req_openctx(req)->dentry)),
+			req->wb_bytes,
+			(long long)req_offset(req));
+		if (status < 0) {
+			if (req->wb_page) {
+				trace_nfs_commit_error(req, status);
+				nfs_mapping_set_error(req->wb_page, status);
+				nfs_inode_remove_request(req);
+			}
+			dprintk_cont(", error = %d\n", status);
+			goto next;
+		}
+
+		/* Okay, COMMIT succeeded, apparently. Check the verifier
+		 * returned by the server against all stored verfs. */
+		if (nfs_write_match_verf(verf, req)) {
+			/* We have a match */
+			if (req->wb_page)
+				nfs_inode_remove_request(req);
+			dprintk_cont(" OK\n");
+			goto next;
+		}
+		/* We have a mismatch. Write the page again */
+		dprintk_cont(" mismatch\n");
+		nfs_mark_request_dirty(req);
+		set_bit(NFS_CONTEXT_RESEND_WRITES, &nfs_req_openctx(req)->flags);
+	next:
+		nfs_unlock_and_release_request(req);
+		/* Latency breaker */
+		cond_resched();
+	}
+	nfss = NFS_SERVER(data->inode);
+	if (atomic_long_read(&nfss->writeback) < NFS_CONGESTION_OFF_THRESH)
+		clear_bdi_congested(inode_to_bdi(data->inode), BLK_RW_ASYNC);
+
+	nfs_init_cinfo(&cinfo, data->inode, data->dreq);
+	nfs_commit_end(cinfo.mds);
+}
+
+static void nfs_commit_release(void *calldata)
+{
+	struct nfs_commit_data *data = calldata;
+
+	data->completion_ops->completion(data);
+	nfs_commitdata_release(calldata);
+}
+
+static const struct rpc_call_ops nfs_commit_ops = {
+	.rpc_call_prepare = nfs_commit_prepare,
+	.rpc_call_done = nfs_commit_done,
+	.rpc_release = nfs_commit_release,
+};
+
+static const struct nfs_commit_completion_ops nfs_commit_completion_ops = {
+	.completion = nfs_commit_release_pages,
+	.resched_write = nfs_commit_resched_write,
+};
+
+int nfs_generic_commit_list(struct inode *inode, struct list_head *head,
+			    int how, struct nfs_commit_info *cinfo)
+{
+	int status;
+
+	status = pnfs_commit_list(inode, head, how, cinfo);
+	if (status == PNFS_NOT_ATTEMPTED)
+		status = nfs_commit_list(inode, head, how, cinfo);
+	return status;
+}
+
+static int __nfs_commit_inode(struct inode *inode, int how,
+		struct writeback_control *wbc)
+{
+	LIST_HEAD(head);
+	struct nfs_commit_info cinfo;
+	int may_wait = how & FLUSH_SYNC;
+	int ret, nscan;
+
+	how &= ~FLUSH_SYNC;
+	nfs_init_cinfo_from_inode(&cinfo, inode);
+	nfs_commit_begin(cinfo.mds);
+	for (;;) {
+		ret = nscan = nfs_scan_commit(inode, &head, &cinfo);
+		if (ret <= 0)
+			break;
+		ret = nfs_generic_commit_list(inode, &head, how, &cinfo);
+		if (ret < 0)
+			break;
+		ret = 0;
+		if (wbc && wbc->sync_mode == WB_SYNC_NONE) {
+			if (nscan < wbc->nr_to_write)
+				wbc->nr_to_write -= nscan;
+			else
+				wbc->nr_to_write = 0;
+		}
+		if (nscan < INT_MAX)
+			break;
+		cond_resched();
+	}
+	nfs_commit_end(cinfo.mds);
+	if (ret || !may_wait)
+		return ret;
+	return wait_on_commit(cinfo.mds);
+}
+
+int nfs_commit_inode(struct inode *inode, int how)
+{
+	return __nfs_commit_inode(inode, how, NULL);
+}
+EXPORT_SYMBOL_GPL(nfs_commit_inode);
+
+int nfs_write_inode(struct inode *inode, struct writeback_control *wbc)
+{
+	struct nfs_inode *nfsi = NFS_I(inode);
+	int flags = FLUSH_SYNC;
+	int ret = 0;
+
+	if (wbc->sync_mode == WB_SYNC_NONE) {
+		/* no commits means nothing needs to be done */
+		if (!atomic_long_read(&nfsi->commit_info.ncommit))
+			goto check_requests_outstanding;
+
+		/* Don't commit yet if this is a non-blocking flush and there
+		 * are a lot of outstanding writes for this mapping.
+		 */
+		if (mapping_tagged(inode->i_mapping, PAGECACHE_TAG_WRITEBACK))
+			goto out_mark_dirty;
+
+		/* don't wait for the COMMIT response */
+		flags = 0;
+	}
+
+	ret = __nfs_commit_inode(inode, flags, wbc);
+	if (!ret) {
+		if (flags & FLUSH_SYNC)
+			return 0;
+	} else if (atomic_long_read(&nfsi->commit_info.ncommit))
+		goto out_mark_dirty;
+
+check_requests_outstanding:
+	if (!atomic_read(&nfsi->commit_info.rpcs_out))
+		return ret;
+out_mark_dirty:
+	__mark_inode_dirty(inode, I_DIRTY_DATASYNC);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(nfs_write_inode);
+
+/*
+ * Wrapper for filemap_write_and_wait_range()
+ *
+ * Needed for pNFS in order to ensure data becomes visible to the
+ * client.
+ */
+int nfs_filemap_write_and_wait_range(struct address_space *mapping,
+		loff_t lstart, loff_t lend)
+{
+	int ret;
+
+	ret = filemap_write_and_wait_range(mapping, lstart, lend);
+	if (ret == 0)
+		ret = pnfs_sync_inode(mapping->host, true);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(nfs_filemap_write_and_wait_range);
+
+/*
+ * flush the inode to disk.
+ */
+int nfs_wb_all(struct inode *inode)
+{
+	int ret;
+
+	trace_nfs_writeback_inode_enter(inode);
+
+	ret = filemap_write_and_wait(inode->i_mapping);
+	if (ret)
+		goto out;
+	ret = nfs_commit_inode(inode, FLUSH_SYNC);
+	if (ret < 0)
+		goto out;
+	pnfs_sync_inode(inode, true);
+	ret = 0;
+
+out:
+	trace_nfs_writeback_inode_exit(inode, ret);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(nfs_wb_all);
+
+int nfs_wb_page_cancel(struct inode *inode, struct page *page)
+{
+	struct nfs_page *req;
+	int ret = 0;
+
+	wait_on_page_writeback(page);
+
+	/* blocking call to cancel all requests and join to a single (head)
+	 * request */
+	req = nfs_lock_and_join_requests(page);
+
+	if (IS_ERR(req)) {
+		ret = PTR_ERR(req);
+	} else if (req) {
+		/* all requests from this page have been cancelled by
+		 * nfs_lock_and_join_requests, so just remove the head
+		 * request from the inode / page_private pointer and
+		 * release it */
+		nfs_inode_remove_request(req);
+		nfs_unlock_and_release_request(req);
+	}
+
+	return ret;
+}
+
+/*
+ * Write back all requests on one page - we do this before reading it.
+ */
+int nfs_wb_page(struct inode *inode, struct page *page)
+{
+	loff_t range_start = page_file_offset(page);
+	loff_t range_end = range_start + (loff_t)(PAGE_SIZE - 1);
+	struct writeback_control wbc = {
+		.sync_mode = WB_SYNC_ALL,
+		.nr_to_write = 0,
+		.range_start = range_start,
+		.range_end = range_end,
+	};
+	int ret;
+
+	trace_nfs_writeback_page_enter(inode);
+
+	for (;;) {
+		wait_on_page_writeback(page);
+		if (clear_page_dirty_for_io(page)) {
+			ret = nfs_writepage_locked(page, &wbc);
+			if (ret < 0)
+				goto out_error;
+			continue;
+		}
+		ret = 0;
+		if (!PagePrivate(page))
+			break;
+		ret = nfs_commit_inode(inode, FLUSH_SYNC);
+		if (ret < 0)
+			goto out_error;
+	}
+out_error:
+	trace_nfs_writeback_page_exit(inode, ret);
+	return ret;
+}
+
+#ifdef CONFIG_MIGRATION
+int nfs_migrate_page(struct address_space *mapping, struct page *newpage,
+		struct page *page, enum migrate_mode mode)
+{
+	/*
+	 * If PagePrivate is set, then the page is currently associated with
+	 * an in-progress read or write request. Don't try to migrate it.
+	 *
+	 * FIXME: we could do this in principle, but we'll need a way to ensure
+	 *        that we can safely release the inode reference while holding
+	 *        the page lock.
+	 */
+	if (PagePrivate(page))
+		return -EBUSY;
+
+	if (!nfs_fscache_release_page(page, GFP_KERNEL))
+		return -EBUSY;
+
+	return migrate_page(mapping, newpage, page, mode);
+}
+#endif
+
+int __init nfs_init_writepagecache(void)
+{
+	nfs_wdata_cachep = kmem_cache_create("nfs_write_data",
+					     sizeof(struct nfs_pgio_header),
+					     0, SLAB_HWCACHE_ALIGN,
+					     NULL);
+	if (nfs_wdata_cachep == NULL)
+		return -ENOMEM;
+
+	nfs_wdata_mempool = mempool_create_slab_pool(MIN_POOL_WRITE,
+						     nfs_wdata_cachep);
+	if (nfs_wdata_mempool == NULL)
+		goto out_destroy_write_cache;
+
+	nfs_cdata_cachep = kmem_cache_create("nfs_commit_data",
+					     sizeof(struct nfs_commit_data),
+					     0, SLAB_HWCACHE_ALIGN,
+					     NULL);
+	if (nfs_cdata_cachep == NULL)
+		goto out_destroy_write_mempool;
+
+	nfs_commit_mempool = mempool_create_slab_pool(MIN_POOL_COMMIT,
+						      nfs_cdata_cachep);
+	if (nfs_commit_mempool == NULL)
+		goto out_destroy_commit_cache;
+
+	/*
+	 * NFS congestion size, scale with available memory.
+	 *
+	 *  64MB:    8192k
+	 * 128MB:   11585k
+	 * 256MB:   16384k
+	 * 512MB:   23170k
+	 *   1GB:   32768k
+	 *   2GB:   46340k
+	 *   4GB:   65536k
+	 *   8GB:   92681k
+	 *  16GB:  131072k
+	 *
+	 * This allows larger machines to have larger/more transfers.
+	 * Limit the default to 256M
+	 */
+	nfs_congestion_kb = (16*int_sqrt(totalram_pages())) << (PAGE_SHIFT-10);
+	if (nfs_congestion_kb > 256*1024)
+		nfs_congestion_kb = 256*1024;
+
+	return 0;
+
+out_destroy_commit_cache:
+	kmem_cache_destroy(nfs_cdata_cachep);
+out_destroy_write_mempool:
+	mempool_destroy(nfs_wdata_mempool);
+out_destroy_write_cache:
+	kmem_cache_destroy(nfs_wdata_cachep);
+	return -ENOMEM;
+}
+
+void nfs_destroy_writepagecache(void)
+{
+	mempool_destroy(nfs_commit_mempool);
+	kmem_cache_destroy(nfs_cdata_cachep);
+	mempool_destroy(nfs_wdata_mempool);
+	kmem_cache_destroy(nfs_wdata_cachep);
+}
+
+static const struct nfs_rw_ops nfs_rw_write_ops = {
+	.rw_alloc_header	= nfs_writehdr_alloc,
+	.rw_free_header		= nfs_writehdr_free,
+	.rw_done		= nfs_writeback_done,
+	.rw_result		= nfs_writeback_result,
+	.rw_initiate		= nfs_initiate_write,
+};
diff --git a/fs/nfs_common/Makefile b/fs/nfs_common/Makefile
new file mode 100644
index 000000000..fa82f5aaa
--- /dev/null
+++ b/fs/nfs_common/Makefile
@@ -0,0 +1,10 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Makefile for Linux filesystem routines that are shared by client and server.
+#
+
+obj-$(CONFIG_NFS_ACL_SUPPORT) += nfs_acl.o
+nfs_acl-objs := nfsacl.o
+
+obj-$(CONFIG_GRACE_PERIOD) += grace.o
+obj-$(CONFIG_GRACE_PERIOD) += nfs_ssc.o
diff --git a/fs/nfs_common/grace.c b/fs/nfs_common/grace.c
new file mode 100644
index 000000000..26f2a50ec
--- /dev/null
+++ b/fs/nfs_common/grace.c
@@ -0,0 +1,143 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Common code for control of lockd and nfsv4 grace periods.
+ *
+ * Transplanted from lockd code
+ */
+
+#include <linux/module.h>
+#include <net/net_namespace.h>
+#include <net/netns/generic.h>
+#include <linux/fs.h>
+
+static unsigned int grace_net_id;
+static DEFINE_SPINLOCK(grace_lock);
+
+/**
+ * locks_start_grace
+ * @net: net namespace that this lock manager belongs to
+ * @lm: who this grace period is for
+ *
+ * A grace period is a period during which locks should not be given
+ * out.  Currently grace periods are only enforced by the two lock
+ * managers (lockd and nfsd), using the locks_in_grace() function to
+ * check when they are in a grace period.
+ *
+ * This function is called to start a grace period.
+ */
+void
+locks_start_grace(struct net *net, struct lock_manager *lm)
+{
+	struct list_head *grace_list = net_generic(net, grace_net_id);
+
+	spin_lock(&grace_lock);
+	if (list_empty(&lm->list))
+		list_add(&lm->list, grace_list);
+	else
+		WARN(1, "double list_add attempt detected in net %x %s\n",
+		     net->ns.inum, (net == &init_net) ? "(init_net)" : "");
+	spin_unlock(&grace_lock);
+}
+EXPORT_SYMBOL_GPL(locks_start_grace);
+
+/**
+ * locks_end_grace
+ * @net: net namespace that this lock manager belongs to
+ * @lm: who this grace period is for
+ *
+ * Call this function to state that the given lock manager is ready to
+ * resume regular locking.  The grace period will not end until all lock
+ * managers that called locks_start_grace() also call locks_end_grace().
+ * Note that callers count on it being safe to call this more than once,
+ * and the second call should be a no-op.
+ */
+void
+locks_end_grace(struct lock_manager *lm)
+{
+	spin_lock(&grace_lock);
+	list_del_init(&lm->list);
+	spin_unlock(&grace_lock);
+}
+EXPORT_SYMBOL_GPL(locks_end_grace);
+
+static bool
+__state_in_grace(struct net *net, bool open)
+{
+	struct list_head *grace_list = net_generic(net, grace_net_id);
+	struct lock_manager *lm;
+
+	if (!open)
+		return !list_empty(grace_list);
+
+	spin_lock(&grace_lock);
+	list_for_each_entry(lm, grace_list, list) {
+		if (lm->block_opens) {
+			spin_unlock(&grace_lock);
+			return true;
+		}
+	}
+	spin_unlock(&grace_lock);
+	return false;
+}
+
+/**
+ * locks_in_grace
+ *
+ * Lock managers call this function to determine when it is OK for them
+ * to answer ordinary lock requests, and when they should accept only
+ * lock reclaims.
+ */
+bool locks_in_grace(struct net *net)
+{
+	return __state_in_grace(net, false);
+}
+EXPORT_SYMBOL_GPL(locks_in_grace);
+
+bool opens_in_grace(struct net *net)
+{
+	return __state_in_grace(net, true);
+}
+EXPORT_SYMBOL_GPL(opens_in_grace);
+
+static int __net_init
+grace_init_net(struct net *net)
+{
+	struct list_head *grace_list = net_generic(net, grace_net_id);
+
+	INIT_LIST_HEAD(grace_list);
+	return 0;
+}
+
+static void __net_exit
+grace_exit_net(struct net *net)
+{
+	struct list_head *grace_list = net_generic(net, grace_net_id);
+
+	WARN_ONCE(!list_empty(grace_list),
+		  "net %x %s: grace_list is not empty\n",
+		  net->ns.inum, __func__);
+}
+
+static struct pernet_operations grace_net_ops = {
+	.init = grace_init_net,
+	.exit = grace_exit_net,
+	.id   = &grace_net_id,
+	.size = sizeof(struct list_head),
+};
+
+static int __init
+init_grace(void)
+{
+	return register_pernet_subsys(&grace_net_ops);
+}
+
+static void __exit
+exit_grace(void)
+{
+	unregister_pernet_subsys(&grace_net_ops);
+}
+
+MODULE_AUTHOR("Jeff Layton <jlayton@primarydata.com>");
+MODULE_LICENSE("GPL");
+module_init(init_grace)
+module_exit(exit_grace)
diff --git a/fs/nfs_common/nfs_ssc.c b/fs/nfs_common/nfs_ssc.c
new file mode 100644
index 000000000..f43bbb373
--- /dev/null
+++ b/fs/nfs_common/nfs_ssc.c
@@ -0,0 +1,94 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * fs/nfs_common/nfs_ssc_comm.c
+ *
+ * Helper for knfsd's SSC to access ops in NFS client modules
+ *
+ * Author: Dai Ngo <dai.ngo@oracle.com>
+ *
+ * Copyright (c) 2020, Oracle and/or its affiliates.
+ */
+
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/nfs_ssc.h>
+#include "../nfs/nfs4_fs.h"
+
+MODULE_LICENSE("GPL");
+
+struct nfs_ssc_client_ops_tbl nfs_ssc_client_tbl;
+EXPORT_SYMBOL_GPL(nfs_ssc_client_tbl);
+
+#ifdef CONFIG_NFS_V4_2
+/**
+ * nfs42_ssc_register - install the NFS_V4 client ops in the nfs_ssc_client_tbl
+ * @ops: NFS_V4 ops to be installed
+ *
+ * Return values:
+ *   None
+ */
+void nfs42_ssc_register(const struct nfs4_ssc_client_ops *ops)
+{
+	nfs_ssc_client_tbl.ssc_nfs4_ops = ops;
+}
+EXPORT_SYMBOL_GPL(nfs42_ssc_register);
+
+/**
+ * nfs42_ssc_unregister - uninstall the NFS_V4 client ops from
+ *				the nfs_ssc_client_tbl
+ * @ops: ops to be uninstalled
+ *
+ * Return values:
+ *   None
+ */
+void nfs42_ssc_unregister(const struct nfs4_ssc_client_ops *ops)
+{
+	if (nfs_ssc_client_tbl.ssc_nfs4_ops != ops)
+		return;
+
+	nfs_ssc_client_tbl.ssc_nfs4_ops = NULL;
+}
+EXPORT_SYMBOL_GPL(nfs42_ssc_unregister);
+#endif /* CONFIG_NFS_V4_2 */
+
+#ifdef CONFIG_NFS_V4_2
+/**
+ * nfs_ssc_register - install the NFS_FS client ops in the nfs_ssc_client_tbl
+ * @ops: NFS_FS ops to be installed
+ *
+ * Return values:
+ *   None
+ */
+void nfs_ssc_register(const struct nfs_ssc_client_ops *ops)
+{
+	nfs_ssc_client_tbl.ssc_nfs_ops = ops;
+}
+EXPORT_SYMBOL_GPL(nfs_ssc_register);
+
+/**
+ * nfs_ssc_unregister - uninstall the NFS_FS client ops from
+ *				the nfs_ssc_client_tbl
+ * @ops: ops to be uninstalled
+ *
+ * Return values:
+ *   None
+ */
+void nfs_ssc_unregister(const struct nfs_ssc_client_ops *ops)
+{
+	if (nfs_ssc_client_tbl.ssc_nfs_ops != ops)
+		return;
+	nfs_ssc_client_tbl.ssc_nfs_ops = NULL;
+}
+EXPORT_SYMBOL_GPL(nfs_ssc_unregister);
+
+#else
+void nfs_ssc_register(const struct nfs_ssc_client_ops *ops)
+{
+}
+EXPORT_SYMBOL_GPL(nfs_ssc_register);
+
+void nfs_ssc_unregister(const struct nfs_ssc_client_ops *ops)
+{
+}
+EXPORT_SYMBOL_GPL(nfs_ssc_unregister);
+#endif /* CONFIG_NFS_V4_2 */
diff --git a/fs/nfs_common/nfsacl.c b/fs/nfs_common/nfsacl.c
new file mode 100644
index 000000000..d056ad2fd
--- /dev/null
+++ b/fs/nfs_common/nfsacl.c
@@ -0,0 +1,297 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * fs/nfs_common/nfsacl.c
+ *
+ *  Copyright (C) 2002-2003 Andreas Gruenbacher <agruen@suse.de>
+ */
+
+/*
+ * The Solaris nfsacl protocol represents some ACLs slightly differently
+ * than POSIX 1003.1e draft 17 does (and we do):
+ *
+ *  - Minimal ACLs always have an ACL_MASK entry, so they have
+ *    four instead of three entries.
+ *  - The ACL_MASK entry in such minimal ACLs always has the same
+ *    permissions as the ACL_GROUP_OBJ entry. (In extended ACLs
+ *    the ACL_MASK and ACL_GROUP_OBJ entries may differ.)
+ *  - The identifier fields of the ACL_USER_OBJ and ACL_GROUP_OBJ
+ *    entries contain the identifiers of the owner and owning group.
+ *    (In POSIX ACLs we always set them to ACL_UNDEFINED_ID).
+ *  - ACL entries in the kernel are kept sorted in ascending order
+ *    of (e_tag, e_id). Solaris ACLs are unsorted.
+ */
+
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/gfp.h>
+#include <linux/sunrpc/xdr.h>
+#include <linux/nfsacl.h>
+#include <linux/nfs3.h>
+#include <linux/sort.h>
+
+MODULE_LICENSE("GPL");
+
+struct nfsacl_encode_desc {
+	struct xdr_array2_desc desc;
+	unsigned int count;
+	struct posix_acl *acl;
+	int typeflag;
+	kuid_t uid;
+	kgid_t gid;
+};
+
+struct nfsacl_simple_acl {
+	struct posix_acl acl;
+	struct posix_acl_entry ace[4];
+};
+
+static int
+xdr_nfsace_encode(struct xdr_array2_desc *desc, void *elem)
+{
+	struct nfsacl_encode_desc *nfsacl_desc =
+		(struct nfsacl_encode_desc *) desc;
+	__be32 *p = elem;
+
+	struct posix_acl_entry *entry =
+		&nfsacl_desc->acl->a_entries[nfsacl_desc->count++];
+
+	*p++ = htonl(entry->e_tag | nfsacl_desc->typeflag);
+	switch(entry->e_tag) {
+		case ACL_USER_OBJ:
+			*p++ = htonl(from_kuid(&init_user_ns, nfsacl_desc->uid));
+			break;
+		case ACL_GROUP_OBJ:
+			*p++ = htonl(from_kgid(&init_user_ns, nfsacl_desc->gid));
+			break;
+		case ACL_USER:
+			*p++ = htonl(from_kuid(&init_user_ns, entry->e_uid));
+			break;
+		case ACL_GROUP:
+			*p++ = htonl(from_kgid(&init_user_ns, entry->e_gid));
+			break;
+		default:  /* Solaris depends on that! */
+			*p++ = 0;
+			break;
+	}
+	*p++ = htonl(entry->e_perm & S_IRWXO);
+	return 0;
+}
+
+/**
+ * nfsacl_encode - Encode an NFSv3 ACL
+ *
+ * @buf: destination xdr_buf to contain XDR encoded ACL
+ * @base: byte offset in xdr_buf where XDR'd ACL begins
+ * @inode: inode of file whose ACL this is
+ * @acl: posix_acl to encode
+ * @encode_entries: whether to encode ACEs as well
+ * @typeflag: ACL type: NFS_ACL_DEFAULT or zero
+ *
+ * Returns size of encoded ACL in bytes or a negative errno value.
+ */
+int nfsacl_encode(struct xdr_buf *buf, unsigned int base, struct inode *inode,
+		  struct posix_acl *acl, int encode_entries, int typeflag)
+{
+	int entries = (acl && acl->a_count) ? max_t(int, acl->a_count, 4) : 0;
+	struct nfsacl_encode_desc nfsacl_desc = {
+		.desc = {
+			.elem_size = 12,
+			.array_len = encode_entries ? entries : 0,
+			.xcode = xdr_nfsace_encode,
+		},
+		.acl = acl,
+		.typeflag = typeflag,
+		.uid = inode->i_uid,
+		.gid = inode->i_gid,
+	};
+	struct nfsacl_simple_acl aclbuf;
+	int err;
+
+	if (entries > NFS_ACL_MAX_ENTRIES ||
+	    xdr_encode_word(buf, base, entries))
+		return -EINVAL;
+	if (encode_entries && acl && acl->a_count == 3) {
+		struct posix_acl *acl2 = &aclbuf.acl;
+
+		/* Avoid the use of posix_acl_alloc().  nfsacl_encode() is
+		 * invoked in contexts where a memory allocation failure is
+		 * fatal.  Fortunately this fake ACL is small enough to
+		 * construct on the stack. */
+		posix_acl_init(acl2, 4);
+
+		/* Insert entries in canonical order: other orders seem
+		 to confuse Solaris VxFS. */
+		acl2->a_entries[0] = acl->a_entries[0];  /* ACL_USER_OBJ */
+		acl2->a_entries[1] = acl->a_entries[1];  /* ACL_GROUP_OBJ */
+		acl2->a_entries[2] = acl->a_entries[1];  /* ACL_MASK */
+		acl2->a_entries[2].e_tag = ACL_MASK;
+		acl2->a_entries[3] = acl->a_entries[2];  /* ACL_OTHER */
+		nfsacl_desc.acl = acl2;
+	}
+	err = xdr_encode_array2(buf, base + 4, &nfsacl_desc.desc);
+	if (!err)
+		err = 8 + nfsacl_desc.desc.elem_size *
+			  nfsacl_desc.desc.array_len;
+	return err;
+}
+EXPORT_SYMBOL_GPL(nfsacl_encode);
+
+struct nfsacl_decode_desc {
+	struct xdr_array2_desc desc;
+	unsigned int count;
+	struct posix_acl *acl;
+};
+
+static int
+xdr_nfsace_decode(struct xdr_array2_desc *desc, void *elem)
+{
+	struct nfsacl_decode_desc *nfsacl_desc =
+		(struct nfsacl_decode_desc *) desc;
+	__be32 *p = elem;
+	struct posix_acl_entry *entry;
+	unsigned int id;
+
+	if (!nfsacl_desc->acl) {
+		if (desc->array_len > NFS_ACL_MAX_ENTRIES)
+			return -EINVAL;
+		nfsacl_desc->acl = posix_acl_alloc(desc->array_len, GFP_KERNEL);
+		if (!nfsacl_desc->acl)
+			return -ENOMEM;
+		nfsacl_desc->count = 0;
+	}
+
+	entry = &nfsacl_desc->acl->a_entries[nfsacl_desc->count++];
+	entry->e_tag = ntohl(*p++) & ~NFS_ACL_DEFAULT;
+	id = ntohl(*p++);
+	entry->e_perm = ntohl(*p++);
+
+	switch(entry->e_tag) {
+		case ACL_USER:
+			entry->e_uid = make_kuid(&init_user_ns, id);
+			if (!uid_valid(entry->e_uid))
+				return -EINVAL;
+			break;
+		case ACL_GROUP:
+			entry->e_gid = make_kgid(&init_user_ns, id);
+			if (!gid_valid(entry->e_gid))
+				return -EINVAL;
+			break;
+		case ACL_USER_OBJ:
+		case ACL_GROUP_OBJ:
+		case ACL_OTHER:
+			if (entry->e_perm & ~S_IRWXO)
+				return -EINVAL;
+			break;
+		case ACL_MASK:
+			/* Solaris sometimes sets additional bits in the mask */
+			entry->e_perm &= S_IRWXO;
+			break;
+		default:
+			return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int
+cmp_acl_entry(const void *x, const void *y)
+{
+	const struct posix_acl_entry *a = x, *b = y;
+
+	if (a->e_tag != b->e_tag)
+		return a->e_tag - b->e_tag;
+	else if ((a->e_tag == ACL_USER) && uid_gt(a->e_uid, b->e_uid))
+		return 1;
+	else if ((a->e_tag == ACL_USER) && uid_lt(a->e_uid, b->e_uid))
+		return -1;
+	else if ((a->e_tag == ACL_GROUP) && gid_gt(a->e_gid, b->e_gid))
+		return 1;
+	else if ((a->e_tag == ACL_GROUP) && gid_lt(a->e_gid, b->e_gid))
+		return -1;
+	else
+		return 0;
+}
+
+/*
+ * Convert from a Solaris ACL to a POSIX 1003.1e draft 17 ACL.
+ */
+static int
+posix_acl_from_nfsacl(struct posix_acl *acl)
+{
+	struct posix_acl_entry *pa, *pe,
+	       *group_obj = NULL, *mask = NULL;
+
+	if (!acl)
+		return 0;
+
+	sort(acl->a_entries, acl->a_count, sizeof(struct posix_acl_entry),
+	     cmp_acl_entry, NULL);
+
+	/* Find the ACL_GROUP_OBJ and ACL_MASK entries. */
+	FOREACH_ACL_ENTRY(pa, acl, pe) {
+		switch(pa->e_tag) {
+			case ACL_USER_OBJ:
+				break;
+			case ACL_GROUP_OBJ:
+				group_obj = pa;
+				break;
+			case ACL_MASK:
+				mask = pa;
+				fallthrough;
+			case ACL_OTHER:
+				break;
+		}
+	}
+	if (acl->a_count == 4 && group_obj && mask &&
+	    mask->e_perm == group_obj->e_perm) {
+		/* remove bogus ACL_MASK entry */
+		memmove(mask, mask+1, (3 - (mask - acl->a_entries)) *
+				      sizeof(struct posix_acl_entry));
+		acl->a_count = 3;
+	}
+	return 0;
+}
+
+/**
+ * nfsacl_decode - Decode an NFSv3 ACL
+ *
+ * @buf: xdr_buf containing XDR'd ACL data to decode
+ * @base: byte offset in xdr_buf where XDR'd ACL begins
+ * @aclcnt: count of ACEs in decoded posix_acl
+ * @pacl: buffer in which to place decoded posix_acl
+ *
+ * Returns the length of the decoded ACL in bytes, or a negative errno value.
+ */
+int nfsacl_decode(struct xdr_buf *buf, unsigned int base, unsigned int *aclcnt,
+		  struct posix_acl **pacl)
+{
+	struct nfsacl_decode_desc nfsacl_desc = {
+		.desc = {
+			.elem_size = 12,
+			.xcode = pacl ? xdr_nfsace_decode : NULL,
+		},
+	};
+	u32 entries;
+	int err;
+
+	if (xdr_decode_word(buf, base, &entries) ||
+	    entries > NFS_ACL_MAX_ENTRIES)
+		return -EINVAL;
+	nfsacl_desc.desc.array_maxlen = entries;
+	err = xdr_decode_array2(buf, base + 4, &nfsacl_desc.desc);
+	if (err)
+		return err;
+	if (pacl) {
+		if (entries != nfsacl_desc.desc.array_len ||
+		    posix_acl_from_nfsacl(nfsacl_desc.acl) != 0) {
+			posix_acl_release(nfsacl_desc.acl);
+			return -EINVAL;
+		}
+		*pacl = nfsacl_desc.acl;
+	}
+	if (aclcnt)
+		*aclcnt = entries;
+	return 8 + nfsacl_desc.desc.elem_size *
+		   nfsacl_desc.desc.array_len;
+}
+EXPORT_SYMBOL_GPL(nfsacl_decode);
diff --git a/fs/nfsd/Kconfig b/fs/nfsd/Kconfig
new file mode 100644
index 000000000..248f1459c
--- /dev/null
+++ b/fs/nfsd/Kconfig
@@ -0,0 +1,159 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config NFSD
+	tristate "NFS server support"
+	depends on INET
+	depends on FILE_LOCKING
+	depends on FSNOTIFY
+	select LOCKD
+	select SUNRPC
+	select EXPORTFS
+	select NFS_ACL_SUPPORT if NFSD_V2_ACL
+	depends on MULTIUSER
+	help
+	  Choose Y here if you want to allow other computers to access
+	  files residing on this system using Sun's Network File System
+	  protocol.  To compile the NFS server support as a module,
+	  choose M here: the module will be called nfsd.
+
+	  You may choose to use a user-space NFS server instead, in which
+	  case you can choose N here.
+
+	  To export local file systems using NFS, you also need to install
+	  user space programs which can be found in the Linux nfs-utils
+	  package, available from http://linux-nfs.org/.  More detail about
+	  the Linux NFS server implementation is available via the
+	  exports(5) man page.
+
+	  Below you can choose which versions of the NFS protocol are
+	  available to clients mounting the NFS server on this system.
+	  Support for NFS version 2 (RFC 1094) is always available when
+	  CONFIG_NFSD is selected.
+
+	  If unsure, say N.
+
+config NFSD_V2_ACL
+	bool
+	depends on NFSD
+
+config NFSD_V3
+	bool "NFS server support for NFS version 3"
+	depends on NFSD
+	help
+	  This option enables support in your system's NFS server for
+	  version 3 of the NFS protocol (RFC 1813).
+
+	  If unsure, say Y.
+
+config NFSD_V3_ACL
+	bool "NFS server support for the NFSv3 ACL protocol extension"
+	depends on NFSD_V3
+	select NFSD_V2_ACL
+	help
+	  Solaris NFS servers support an auxiliary NFSv3 ACL protocol that
+	  never became an official part of the NFS version 3 protocol.
+	  This protocol extension allows applications on NFS clients to
+	  manipulate POSIX Access Control Lists on files residing on NFS
+	  servers.  NFS servers enforce POSIX ACLs on local files whether
+	  this protocol is available or not.
+
+	  This option enables support in your system's NFS server for the
+	  NFSv3 ACL protocol extension allowing NFS clients to manipulate
+	  POSIX ACLs on files exported by your system's NFS server.  NFS
+	  clients which support the Solaris NFSv3 ACL protocol can then
+	  access and modify ACLs on your NFS server.
+
+	  To store ACLs on your NFS server, you also need to enable ACL-
+	  related CONFIG options for your local file systems of choice.
+
+	  If unsure, say N.
+
+config NFSD_V4
+	bool "NFS server support for NFS version 4"
+	depends on NFSD && PROC_FS
+	select NFSD_V3
+	select FS_POSIX_ACL
+	select SUNRPC_GSS
+	select CRYPTO
+	select CRYPTO_MD5
+	select CRYPTO_SHA256
+	select GRACE_PERIOD
+	help
+	  This option enables support in your system's NFS server for
+	  version 4 of the NFS protocol (RFC 3530).
+
+	  To export files using NFSv4, you need to install additional user
+	  space programs which can be found in the Linux nfs-utils package,
+	  available from http://linux-nfs.org/.
+
+	  If unsure, say N.
+
+config NFSD_PNFS
+	bool
+
+config NFSD_BLOCKLAYOUT
+	bool "NFSv4.1 server support for pNFS block layouts"
+	depends on NFSD_V4 && BLOCK
+	select NFSD_PNFS
+	select EXPORTFS_BLOCK_OPS
+	help
+	  This option enables support for the exporting pNFS block layouts
+	  in the kernel's NFS server. The pNFS block layout enables NFS
+	  clients to directly perform I/O to block devices accesible to both
+	  the server and the clients.  See RFC 5663 for more details.
+
+	  If unsure, say N.
+
+config NFSD_SCSILAYOUT
+	bool "NFSv4.1 server support for pNFS SCSI layouts"
+	depends on NFSD_V4 && BLOCK
+	select NFSD_PNFS
+	select EXPORTFS_BLOCK_OPS
+	select BLK_SCSI_REQUEST
+	help
+	  This option enables support for the exporting pNFS SCSI layouts
+	  in the kernel's NFS server. The pNFS SCSI layout enables NFS
+	  clients to directly perform I/O to SCSI devices accesible to both
+	  the server and the clients.  See draft-ietf-nfsv4-scsi-layout for
+	  more details.
+
+	  If unsure, say N.
+
+config NFSD_FLEXFILELAYOUT
+	bool "NFSv4.1 server support for pNFS Flex File layouts"
+	depends on NFSD_V4
+	select NFSD_PNFS
+	help
+	  This option enables support for the exporting pNFS Flex File
+	  layouts in the kernel's NFS server. The pNFS Flex File  layout
+	  enables NFS clients to directly perform I/O to NFSv3 devices
+	  accesible to both the server and the clients.  See
+	  draft-ietf-nfsv4-flex-files for more details.
+
+	  Warning, this server implements the bare minimum functionality
+	  to be a flex file server - it is for testing the client,
+	  not for use in production.
+
+	  If unsure, say N.
+
+config NFSD_V4_2_INTER_SSC
+	bool "NFSv4.2 inter server to server COPY"
+	depends on NFSD_V4 && NFS_V4_1 && NFS_V4_2
+	help
+	  This option enables support for NFSv4.2 inter server to
+	  server copy where the destination server calls the NFSv4.2
+	  client to read the data to copy from the source server.
+
+	  If unsure, say N.
+
+config NFSD_V4_SECURITY_LABEL
+	bool "Provide Security Label support for NFSv4 server"
+	depends on NFSD_V4 && SECURITY
+	help
+
+	Say Y here if you want enable fine-grained security label attribute
+	support for NFS version 4.  Security labels allow security modules like
+	SELinux and Smack to label files to facilitate enforcement of their policies.
+	Without this an NFSv4 mount will have the same label on each file.
+
+	If you do not wish to enable fine-grained security labels SELinux or
+	Smack policies on NFSv4 files, say N.
diff --git a/fs/nfsd/Makefile b/fs/nfsd/Makefile
new file mode 100644
index 000000000..3f0983e93
--- /dev/null
+++ b/fs/nfsd/Makefile
@@ -0,0 +1,24 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for the Linux nfs server
+#
+
+ccflags-y += -I$(src)			# needed for trace events
+
+obj-$(CONFIG_NFSD)	+= nfsd.o
+
+# this one should be compiled first, as the tracing macros can easily blow up
+nfsd-y			+= trace.o
+
+nfsd-y 			+= nfssvc.o nfsctl.o nfsproc.o nfsfh.o vfs.o \
+			   export.o auth.o lockd.o nfscache.o nfsxdr.o \
+			   stats.o filecache.o
+nfsd-$(CONFIG_NFSD_V2_ACL) += nfs2acl.o
+nfsd-$(CONFIG_NFSD_V3)	+= nfs3proc.o nfs3xdr.o
+nfsd-$(CONFIG_NFSD_V3_ACL) += nfs3acl.o
+nfsd-$(CONFIG_NFSD_V4)	+= nfs4proc.o nfs4xdr.o nfs4state.o nfs4idmap.o \
+			   nfs4acl.o nfs4callback.o nfs4recover.o
+nfsd-$(CONFIG_NFSD_PNFS) += nfs4layouts.o
+nfsd-$(CONFIG_NFSD_BLOCKLAYOUT) += blocklayout.o blocklayoutxdr.o
+nfsd-$(CONFIG_NFSD_SCSILAYOUT) += blocklayout.o blocklayoutxdr.o
+nfsd-$(CONFIG_NFSD_FLEXFILELAYOUT) += flexfilelayout.o flexfilelayoutxdr.o
diff --git a/fs/nfsd/acl.h b/fs/nfsd/acl.h
new file mode 100644
index 000000000..ba14d2f4b
--- /dev/null
+++ b/fs/nfsd/acl.h
@@ -0,0 +1,51 @@
+/*
+ *  Common NFSv4 ACL handling definitions.
+ *
+ *  Copyright (c) 2002 The Regents of the University of Michigan.
+ *  All rights reserved.
+ *
+ *  Marius Aamodt Eriksen <marius@umich.edu>
+ *
+ *  Redistribution and use in source and binary forms, with or without
+ *  modification, are permitted provided that the following conditions
+ *  are met:
+ *
+ *  1. Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *  2. Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *  3. Neither the name of the University nor the names of its
+ *     contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+ *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef LINUX_NFS4_ACL_H
+#define LINUX_NFS4_ACL_H
+
+struct nfs4_acl;
+struct svc_fh;
+struct svc_rqst;
+
+int nfs4_acl_bytes(int entries);
+int nfs4_acl_get_whotype(char *, u32);
+__be32 nfs4_acl_write_who(struct xdr_stream *xdr, int who);
+
+int nfsd4_get_nfs4_acl(struct svc_rqst *rqstp, struct dentry *dentry,
+		struct nfs4_acl **acl);
+__be32 nfsd4_set_nfs4_acl(struct svc_rqst *rqstp, struct svc_fh *fhp,
+		struct nfs4_acl *acl);
+
+#endif /* LINUX_NFS4_ACL_H */
diff --git a/fs/nfsd/auth.c b/fs/nfsd/auth.c
new file mode 100644
index 000000000..fdf2aad73
--- /dev/null
+++ b/fs/nfsd/auth.c
@@ -0,0 +1,94 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de> */
+
+#include <linux/sched.h>
+#include "nfsd.h"
+#include "auth.h"
+
+int nfsexp_flags(struct svc_rqst *rqstp, struct svc_export *exp)
+{
+	struct exp_flavor_info *f;
+	struct exp_flavor_info *end = exp->ex_flavors + exp->ex_nflavors;
+
+	for (f = exp->ex_flavors; f < end; f++) {
+		if (f->pseudoflavor == rqstp->rq_cred.cr_flavor)
+			return f->flags;
+	}
+	return exp->ex_flags;
+
+}
+
+int nfsd_setuser(struct svc_rqst *rqstp, struct svc_export *exp)
+{
+	struct group_info *rqgi;
+	struct group_info *gi;
+	struct cred *new;
+	int i;
+	int flags = nfsexp_flags(rqstp, exp);
+
+	validate_process_creds();
+
+	/* discard any old override before preparing the new set */
+	revert_creds(get_cred(current_real_cred()));
+	new = prepare_creds();
+	if (!new)
+		return -ENOMEM;
+
+	new->fsuid = rqstp->rq_cred.cr_uid;
+	new->fsgid = rqstp->rq_cred.cr_gid;
+
+	rqgi = rqstp->rq_cred.cr_group_info;
+
+	if (flags & NFSEXP_ALLSQUASH) {
+		new->fsuid = exp->ex_anon_uid;
+		new->fsgid = exp->ex_anon_gid;
+		gi = groups_alloc(0);
+		if (!gi)
+			goto oom;
+	} else if (flags & NFSEXP_ROOTSQUASH) {
+		if (uid_eq(new->fsuid, GLOBAL_ROOT_UID))
+			new->fsuid = exp->ex_anon_uid;
+		if (gid_eq(new->fsgid, GLOBAL_ROOT_GID))
+			new->fsgid = exp->ex_anon_gid;
+
+		gi = groups_alloc(rqgi->ngroups);
+		if (!gi)
+			goto oom;
+
+		for (i = 0; i < rqgi->ngroups; i++) {
+			if (gid_eq(GLOBAL_ROOT_GID, rqgi->gid[i]))
+				gi->gid[i] = exp->ex_anon_gid;
+			else
+				gi->gid[i] = rqgi->gid[i];
+		}
+
+		/* Each thread allocates its own gi, no race */
+		groups_sort(gi);
+	} else {
+		gi = get_group_info(rqgi);
+	}
+
+	if (uid_eq(new->fsuid, INVALID_UID))
+		new->fsuid = exp->ex_anon_uid;
+	if (gid_eq(new->fsgid, INVALID_GID))
+		new->fsgid = exp->ex_anon_gid;
+
+	set_groups(new, gi);
+	put_group_info(gi);
+
+	if (!uid_eq(new->fsuid, GLOBAL_ROOT_UID))
+		new->cap_effective = cap_drop_nfsd_set(new->cap_effective);
+	else
+		new->cap_effective = cap_raise_nfsd_set(new->cap_effective,
+							new->cap_permitted);
+	validate_process_creds();
+	put_cred(override_creds(new));
+	put_cred(new);
+	validate_process_creds();
+	return 0;
+
+oom:
+	abort_creds(new);
+	return -ENOMEM;
+}
+
diff --git a/fs/nfsd/auth.h b/fs/nfsd/auth.h
new file mode 100644
index 000000000..dbd66424f
--- /dev/null
+++ b/fs/nfsd/auth.h
@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * nfsd-specific authentication stuff.
+ *
+ * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
+ */
+
+#ifndef LINUX_NFSD_AUTH_H
+#define LINUX_NFSD_AUTH_H
+
+/*
+ * Set the current process's fsuid/fsgid etc to those of the NFS
+ * client user
+ */
+int nfsd_setuser(struct svc_rqst *, struct svc_export *);
+
+#endif /* LINUX_NFSD_AUTH_H */
diff --git a/fs/nfsd/blocklayout.c b/fs/nfsd/blocklayout.c
new file mode 100644
index 000000000..a07c39c94
--- /dev/null
+++ b/fs/nfsd/blocklayout.c
@@ -0,0 +1,433 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2014-2016 Christoph Hellwig.
+ */
+#include <linux/exportfs.h>
+#include <linux/iomap.h>
+#include <linux/genhd.h>
+#include <linux/slab.h>
+#include <linux/pr.h>
+
+#include <linux/nfsd/debug.h>
+#include <scsi/scsi_proto.h>
+#include <scsi/scsi_common.h>
+#include <scsi/scsi_request.h>
+
+#include "blocklayoutxdr.h"
+#include "pnfs.h"
+#include "filecache.h"
+
+#define NFSDDBG_FACILITY	NFSDDBG_PNFS
+
+
+static __be32
+nfsd4_block_proc_layoutget(struct inode *inode, const struct svc_fh *fhp,
+		struct nfsd4_layoutget *args)
+{
+	struct nfsd4_layout_seg *seg = &args->lg_seg;
+	struct super_block *sb = inode->i_sb;
+	u32 block_size = i_blocksize(inode);
+	struct pnfs_block_extent *bex;
+	struct iomap iomap;
+	u32 device_generation = 0;
+	int error;
+
+	if (seg->offset & (block_size - 1)) {
+		dprintk("pnfsd: I/O misaligned\n");
+		goto out_layoutunavailable;
+	}
+
+	/*
+	 * Some clients barf on non-zero block numbers for NONE or INVALID
+	 * layouts, so make sure to zero the whole structure.
+	 */
+	error = -ENOMEM;
+	bex = kzalloc(sizeof(*bex), GFP_KERNEL);
+	if (!bex)
+		goto out_error;
+	args->lg_content = bex;
+
+	error = sb->s_export_op->map_blocks(inode, seg->offset, seg->length,
+					    &iomap, seg->iomode != IOMODE_READ,
+					    &device_generation);
+	if (error) {
+		if (error == -ENXIO)
+			goto out_layoutunavailable;
+		goto out_error;
+	}
+
+	if (iomap.length < args->lg_minlength) {
+		dprintk("pnfsd: extent smaller than minlength\n");
+		goto out_layoutunavailable;
+	}
+
+	switch (iomap.type) {
+	case IOMAP_MAPPED:
+		if (seg->iomode == IOMODE_READ)
+			bex->es = PNFS_BLOCK_READ_DATA;
+		else
+			bex->es = PNFS_BLOCK_READWRITE_DATA;
+		bex->soff = iomap.addr;
+		break;
+	case IOMAP_UNWRITTEN:
+		if (seg->iomode & IOMODE_RW) {
+			/*
+			 * Crack monkey special case from section 2.3.1.
+			 */
+			if (args->lg_minlength == 0) {
+				dprintk("pnfsd: no soup for you!\n");
+				goto out_layoutunavailable;
+			}
+
+			bex->es = PNFS_BLOCK_INVALID_DATA;
+			bex->soff = iomap.addr;
+			break;
+		}
+		fallthrough;
+	case IOMAP_HOLE:
+		if (seg->iomode == IOMODE_READ) {
+			bex->es = PNFS_BLOCK_NONE_DATA;
+			break;
+		}
+		fallthrough;
+	case IOMAP_DELALLOC:
+	default:
+		WARN(1, "pnfsd: filesystem returned %d extent\n", iomap.type);
+		goto out_layoutunavailable;
+	}
+
+	error = nfsd4_set_deviceid(&bex->vol_id, fhp, device_generation);
+	if (error)
+		goto out_error;
+	bex->foff = iomap.offset;
+	bex->len = iomap.length;
+
+	seg->offset = iomap.offset;
+	seg->length = iomap.length;
+
+	dprintk("GET: 0x%llx:0x%llx %d\n", bex->foff, bex->len, bex->es);
+	return 0;
+
+out_error:
+	seg->length = 0;
+	return nfserrno(error);
+out_layoutunavailable:
+	seg->length = 0;
+	return nfserr_layoutunavailable;
+}
+
+static __be32
+nfsd4_block_commit_blocks(struct inode *inode, struct nfsd4_layoutcommit *lcp,
+		struct iomap *iomaps, int nr_iomaps)
+{
+	loff_t new_size = lcp->lc_last_wr + 1;
+	struct iattr iattr = { .ia_valid = 0 };
+	int error;
+
+	if (lcp->lc_mtime.tv_nsec == UTIME_NOW ||
+	    timespec64_compare(&lcp->lc_mtime, &inode->i_mtime) < 0)
+		lcp->lc_mtime = current_time(inode);
+	iattr.ia_valid |= ATTR_ATIME | ATTR_CTIME | ATTR_MTIME;
+	iattr.ia_atime = iattr.ia_ctime = iattr.ia_mtime = lcp->lc_mtime;
+
+	if (new_size > i_size_read(inode)) {
+		iattr.ia_valid |= ATTR_SIZE;
+		iattr.ia_size = new_size;
+	}
+
+	error = inode->i_sb->s_export_op->commit_blocks(inode, iomaps,
+			nr_iomaps, &iattr);
+	kfree(iomaps);
+	return nfserrno(error);
+}
+
+#ifdef CONFIG_NFSD_BLOCKLAYOUT
+static int
+nfsd4_block_get_device_info_simple(struct super_block *sb,
+		struct nfsd4_getdeviceinfo *gdp)
+{
+	struct pnfs_block_deviceaddr *dev;
+	struct pnfs_block_volume *b;
+
+	dev = kzalloc(sizeof(struct pnfs_block_deviceaddr) +
+		      sizeof(struct pnfs_block_volume), GFP_KERNEL);
+	if (!dev)
+		return -ENOMEM;
+	gdp->gd_device = dev;
+
+	dev->nr_volumes = 1;
+	b = &dev->volumes[0];
+
+	b->type = PNFS_BLOCK_VOLUME_SIMPLE;
+	b->simple.sig_len = PNFS_BLOCK_UUID_LEN;
+	return sb->s_export_op->get_uuid(sb, b->simple.sig, &b->simple.sig_len,
+			&b->simple.offset);
+}
+
+static __be32
+nfsd4_block_proc_getdeviceinfo(struct super_block *sb,
+		struct svc_rqst *rqstp,
+		struct nfs4_client *clp,
+		struct nfsd4_getdeviceinfo *gdp)
+{
+	if (bdev_is_partition(sb->s_bdev))
+		return nfserr_inval;
+	return nfserrno(nfsd4_block_get_device_info_simple(sb, gdp));
+}
+
+static __be32
+nfsd4_block_proc_layoutcommit(struct inode *inode,
+		struct nfsd4_layoutcommit *lcp)
+{
+	struct iomap *iomaps;
+	int nr_iomaps;
+
+	nr_iomaps = nfsd4_block_decode_layoutupdate(lcp->lc_up_layout,
+			lcp->lc_up_len, &iomaps, i_blocksize(inode));
+	if (nr_iomaps < 0)
+		return nfserrno(nr_iomaps);
+
+	return nfsd4_block_commit_blocks(inode, lcp, iomaps, nr_iomaps);
+}
+
+const struct nfsd4_layout_ops bl_layout_ops = {
+	/*
+	 * Pretend that we send notification to the client.  This is a blatant
+	 * lie to force recent Linux clients to cache our device IDs.
+	 * We rarely ever change the device ID, so the harm of leaking deviceids
+	 * for a while isn't too bad.  Unfortunately RFC5661 is a complete mess
+	 * in this regard, but I filed errata 4119 for this a while ago, and
+	 * hopefully the Linux client will eventually start caching deviceids
+	 * without this again.
+	 */
+	.notify_types		=
+			NOTIFY_DEVICEID4_DELETE | NOTIFY_DEVICEID4_CHANGE,
+	.proc_getdeviceinfo	= nfsd4_block_proc_getdeviceinfo,
+	.encode_getdeviceinfo	= nfsd4_block_encode_getdeviceinfo,
+	.proc_layoutget		= nfsd4_block_proc_layoutget,
+	.encode_layoutget	= nfsd4_block_encode_layoutget,
+	.proc_layoutcommit	= nfsd4_block_proc_layoutcommit,
+};
+#endif /* CONFIG_NFSD_BLOCKLAYOUT */
+
+#ifdef CONFIG_NFSD_SCSILAYOUT
+static int nfsd4_scsi_identify_device(struct block_device *bdev,
+		struct pnfs_block_volume *b)
+{
+	struct request_queue *q = bdev->bd_disk->queue;
+	struct request *rq;
+	struct scsi_request *req;
+	/*
+	 * The allocation length (passed in bytes 3 and 4 of the INQUIRY
+	 * command descriptor block) specifies the number of bytes that have
+	 * been allocated for the data-in buffer.
+	 * 252 is the highest one-byte value that is a multiple of 4.
+	 * 65532 is the highest two-byte value that is a multiple of 4.
+	 */
+	size_t bufflen = 252, maxlen = 65532, len, id_len;
+	u8 *buf, *d, type, assoc;
+	int retries = 1, error;
+
+	if (WARN_ON_ONCE(!blk_queue_scsi_passthrough(q)))
+		return -EINVAL;
+
+again:
+	buf = kzalloc(bufflen, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	rq = blk_get_request(q, REQ_OP_SCSI_IN, 0);
+	if (IS_ERR(rq)) {
+		error = -ENOMEM;
+		goto out_free_buf;
+	}
+	req = scsi_req(rq);
+
+	error = blk_rq_map_kern(q, rq, buf, bufflen, GFP_KERNEL);
+	if (error)
+		goto out_put_request;
+
+	req->cmd[0] = INQUIRY;
+	req->cmd[1] = 1;
+	req->cmd[2] = 0x83;
+	req->cmd[3] = bufflen >> 8;
+	req->cmd[4] = bufflen & 0xff;
+	req->cmd_len = COMMAND_SIZE(INQUIRY);
+
+	blk_execute_rq(rq->q, NULL, rq, 1);
+	if (req->result) {
+		pr_err("pNFS: INQUIRY 0x83 failed with: %x\n",
+			req->result);
+		error = -EIO;
+		goto out_put_request;
+	}
+
+	len = (buf[2] << 8) + buf[3] + 4;
+	if (len > bufflen) {
+		if (len <= maxlen && retries--) {
+			blk_put_request(rq);
+			kfree(buf);
+			bufflen = len;
+			goto again;
+		}
+		pr_err("pNFS: INQUIRY 0x83 response invalid (len = %zd)\n",
+			len);
+		goto out_put_request;
+	}
+
+	d = buf + 4;
+	for (d = buf + 4; d < buf + len; d += id_len + 4) {
+		id_len = d[3];
+		type = d[1] & 0xf;
+		assoc = (d[1] >> 4) & 0x3;
+
+		/*
+		 * We only care about a EUI-64 and NAA designator types
+		 * with LU association.
+		 */
+		if (assoc != 0x00)
+			continue;
+		if (type != 0x02 && type != 0x03)
+			continue;
+		if (id_len != 8 && id_len != 12 && id_len != 16)
+			continue;
+
+		b->scsi.code_set = PS_CODE_SET_BINARY;
+		b->scsi.designator_type = type == 0x02 ?
+			PS_DESIGNATOR_EUI64 : PS_DESIGNATOR_NAA;
+		b->scsi.designator_len = id_len;
+		memcpy(b->scsi.designator, d + 4, id_len);
+
+		/*
+		 * If we found a 8 or 12 byte descriptor continue on to
+		 * see if a 16 byte one is available.  If we find a
+		 * 16 byte descriptor we're done.
+		 */
+		if (id_len == 16)
+			break;
+	}
+
+out_put_request:
+	blk_put_request(rq);
+out_free_buf:
+	kfree(buf);
+	return error;
+}
+
+#define NFSD_MDS_PR_KEY		0x0100000000000000ULL
+
+/*
+ * We use the client ID as a unique key for the reservations.
+ * This allows us to easily fence a client when recalls fail.
+ */
+static u64 nfsd4_scsi_pr_key(struct nfs4_client *clp)
+{
+	return ((u64)clp->cl_clientid.cl_boot << 32) | clp->cl_clientid.cl_id;
+}
+
+static int
+nfsd4_block_get_device_info_scsi(struct super_block *sb,
+		struct nfs4_client *clp,
+		struct nfsd4_getdeviceinfo *gdp)
+{
+	struct pnfs_block_deviceaddr *dev;
+	struct pnfs_block_volume *b;
+	const struct pr_ops *ops;
+	int error;
+
+	dev = kzalloc(sizeof(struct pnfs_block_deviceaddr) +
+		      sizeof(struct pnfs_block_volume), GFP_KERNEL);
+	if (!dev)
+		return -ENOMEM;
+	gdp->gd_device = dev;
+
+	dev->nr_volumes = 1;
+	b = &dev->volumes[0];
+
+	b->type = PNFS_BLOCK_VOLUME_SCSI;
+	b->scsi.pr_key = nfsd4_scsi_pr_key(clp);
+
+	error = nfsd4_scsi_identify_device(sb->s_bdev, b);
+	if (error)
+		return error;
+
+	ops = sb->s_bdev->bd_disk->fops->pr_ops;
+	if (!ops) {
+		pr_err("pNFS: device %s does not support PRs.\n",
+			sb->s_id);
+		return -EINVAL;
+	}
+
+	error = ops->pr_register(sb->s_bdev, 0, NFSD_MDS_PR_KEY, true);
+	if (error) {
+		pr_err("pNFS: failed to register key for device %s.\n",
+			sb->s_id);
+		return -EINVAL;
+	}
+
+	error = ops->pr_reserve(sb->s_bdev, NFSD_MDS_PR_KEY,
+			PR_EXCLUSIVE_ACCESS_REG_ONLY, 0);
+	if (error) {
+		pr_err("pNFS: failed to reserve device %s.\n",
+			sb->s_id);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static __be32
+nfsd4_scsi_proc_getdeviceinfo(struct super_block *sb,
+		struct svc_rqst *rqstp,
+		struct nfs4_client *clp,
+		struct nfsd4_getdeviceinfo *gdp)
+{
+	if (bdev_is_partition(sb->s_bdev))
+		return nfserr_inval;
+	return nfserrno(nfsd4_block_get_device_info_scsi(sb, clp, gdp));
+}
+static __be32
+nfsd4_scsi_proc_layoutcommit(struct inode *inode,
+		struct nfsd4_layoutcommit *lcp)
+{
+	struct iomap *iomaps;
+	int nr_iomaps;
+
+	nr_iomaps = nfsd4_scsi_decode_layoutupdate(lcp->lc_up_layout,
+			lcp->lc_up_len, &iomaps, i_blocksize(inode));
+	if (nr_iomaps < 0)
+		return nfserrno(nr_iomaps);
+
+	return nfsd4_block_commit_blocks(inode, lcp, iomaps, nr_iomaps);
+}
+
+static void
+nfsd4_scsi_fence_client(struct nfs4_layout_stateid *ls)
+{
+	struct nfs4_client *clp = ls->ls_stid.sc_client;
+	struct block_device *bdev = ls->ls_file->nf_file->f_path.mnt->mnt_sb->s_bdev;
+
+	bdev->bd_disk->fops->pr_ops->pr_preempt(bdev, NFSD_MDS_PR_KEY,
+			nfsd4_scsi_pr_key(clp), 0, true);
+}
+
+const struct nfsd4_layout_ops scsi_layout_ops = {
+	/*
+	 * Pretend that we send notification to the client.  This is a blatant
+	 * lie to force recent Linux clients to cache our device IDs.
+	 * We rarely ever change the device ID, so the harm of leaking deviceids
+	 * for a while isn't too bad.  Unfortunately RFC5661 is a complete mess
+	 * in this regard, but I filed errata 4119 for this a while ago, and
+	 * hopefully the Linux client will eventually start caching deviceids
+	 * without this again.
+	 */
+	.notify_types		=
+			NOTIFY_DEVICEID4_DELETE | NOTIFY_DEVICEID4_CHANGE,
+	.proc_getdeviceinfo	= nfsd4_scsi_proc_getdeviceinfo,
+	.encode_getdeviceinfo	= nfsd4_block_encode_getdeviceinfo,
+	.proc_layoutget		= nfsd4_block_proc_layoutget,
+	.encode_layoutget	= nfsd4_block_encode_layoutget,
+	.proc_layoutcommit	= nfsd4_scsi_proc_layoutcommit,
+	.fence_client		= nfsd4_scsi_fence_client,
+};
+#endif /* CONFIG_NFSD_SCSILAYOUT */
diff --git a/fs/nfsd/blocklayoutxdr.c b/fs/nfsd/blocklayoutxdr.c
new file mode 100644
index 000000000..2455dc8be
--- /dev/null
+++ b/fs/nfsd/blocklayoutxdr.c
@@ -0,0 +1,235 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2014-2016 Christoph Hellwig.
+ */
+#include <linux/sunrpc/svc.h>
+#include <linux/exportfs.h>
+#include <linux/iomap.h>
+#include <linux/nfs4.h>
+
+#include "nfsd.h"
+#include "blocklayoutxdr.h"
+
+#define NFSDDBG_FACILITY	NFSDDBG_PNFS
+
+
+__be32
+nfsd4_block_encode_layoutget(struct xdr_stream *xdr,
+		struct nfsd4_layoutget *lgp)
+{
+	struct pnfs_block_extent *b = lgp->lg_content;
+	int len = sizeof(__be32) + 5 * sizeof(__be64) + sizeof(__be32);
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, sizeof(__be32) + len);
+	if (!p)
+		return nfserr_toosmall;
+
+	*p++ = cpu_to_be32(len);
+	*p++ = cpu_to_be32(1);		/* we always return a single extent */
+
+	p = xdr_encode_opaque_fixed(p, &b->vol_id,
+			sizeof(struct nfsd4_deviceid));
+	p = xdr_encode_hyper(p, b->foff);
+	p = xdr_encode_hyper(p, b->len);
+	p = xdr_encode_hyper(p, b->soff);
+	*p++ = cpu_to_be32(b->es);
+	return 0;
+}
+
+static int
+nfsd4_block_encode_volume(struct xdr_stream *xdr, struct pnfs_block_volume *b)
+{
+	__be32 *p;
+	int len;
+
+	switch (b->type) {
+	case PNFS_BLOCK_VOLUME_SIMPLE:
+		len = 4 + 4 + 8 + 4 + (XDR_QUADLEN(b->simple.sig_len) << 2);
+		p = xdr_reserve_space(xdr, len);
+		if (!p)
+			return -ETOOSMALL;
+
+		*p++ = cpu_to_be32(b->type);
+		*p++ = cpu_to_be32(1);	/* single signature */
+		p = xdr_encode_hyper(p, b->simple.offset);
+		p = xdr_encode_opaque(p, b->simple.sig, b->simple.sig_len);
+		break;
+	case PNFS_BLOCK_VOLUME_SCSI:
+		len = 4 + 4 + 4 + 4 + (XDR_QUADLEN(b->scsi.designator_len) << 2) + 8;
+		p = xdr_reserve_space(xdr, len);
+		if (!p)
+			return -ETOOSMALL;
+
+		*p++ = cpu_to_be32(b->type);
+		*p++ = cpu_to_be32(b->scsi.code_set);
+		*p++ = cpu_to_be32(b->scsi.designator_type);
+		p = xdr_encode_opaque(p, b->scsi.designator, b->scsi.designator_len);
+		p = xdr_encode_hyper(p, b->scsi.pr_key);
+		break;
+	default:
+		return -ENOTSUPP;
+	}
+
+	return len;
+}
+
+__be32
+nfsd4_block_encode_getdeviceinfo(struct xdr_stream *xdr,
+		struct nfsd4_getdeviceinfo *gdp)
+{
+	struct pnfs_block_deviceaddr *dev = gdp->gd_device;
+	int len = sizeof(__be32), ret, i;
+	__be32 *p;
+
+	/*
+	 * See paragraph 5 of RFC 8881 S18.40.3.
+	 */
+	if (!gdp->gd_maxcount) {
+		if (xdr_stream_encode_u32(xdr, 0) != XDR_UNIT)
+			return nfserr_resource;
+		return nfs_ok;
+	}
+
+	p = xdr_reserve_space(xdr, len + sizeof(__be32));
+	if (!p)
+		return nfserr_resource;
+
+	for (i = 0; i < dev->nr_volumes; i++) {
+		ret = nfsd4_block_encode_volume(xdr, &dev->volumes[i]);
+		if (ret < 0)
+			return nfserrno(ret);
+		len += ret;
+	}
+
+	/*
+	 * Fill in the overall length and number of volumes at the beginning
+	 * of the layout.
+	 */
+	*p++ = cpu_to_be32(len);
+	*p++ = cpu_to_be32(dev->nr_volumes);
+	return 0;
+}
+
+int
+nfsd4_block_decode_layoutupdate(__be32 *p, u32 len, struct iomap **iomapp,
+		u32 block_size)
+{
+	struct iomap *iomaps;
+	u32 nr_iomaps, i;
+
+	if (len < sizeof(u32)) {
+		dprintk("%s: extent array too small: %u\n", __func__, len);
+		return -EINVAL;
+	}
+	len -= sizeof(u32);
+	if (len % PNFS_BLOCK_EXTENT_SIZE) {
+		dprintk("%s: extent array invalid: %u\n", __func__, len);
+		return -EINVAL;
+	}
+
+	nr_iomaps = be32_to_cpup(p++);
+	if (nr_iomaps != len / PNFS_BLOCK_EXTENT_SIZE) {
+		dprintk("%s: extent array size mismatch: %u/%u\n",
+			__func__, len, nr_iomaps);
+		return -EINVAL;
+	}
+
+	iomaps = kcalloc(nr_iomaps, sizeof(*iomaps), GFP_KERNEL);
+	if (!iomaps) {
+		dprintk("%s: failed to allocate extent array\n", __func__);
+		return -ENOMEM;
+	}
+
+	for (i = 0; i < nr_iomaps; i++) {
+		struct pnfs_block_extent bex;
+
+		memcpy(&bex.vol_id, p, sizeof(struct nfsd4_deviceid));
+		p += XDR_QUADLEN(sizeof(struct nfsd4_deviceid));
+
+		p = xdr_decode_hyper(p, &bex.foff);
+		if (bex.foff & (block_size - 1)) {
+			dprintk("%s: unaligned offset 0x%llx\n",
+				__func__, bex.foff);
+			goto fail;
+		}
+		p = xdr_decode_hyper(p, &bex.len);
+		if (bex.len & (block_size - 1)) {
+			dprintk("%s: unaligned length 0x%llx\n",
+				__func__, bex.foff);
+			goto fail;
+		}
+		p = xdr_decode_hyper(p, &bex.soff);
+		if (bex.soff & (block_size - 1)) {
+			dprintk("%s: unaligned disk offset 0x%llx\n",
+				__func__, bex.soff);
+			goto fail;
+		}
+		bex.es = be32_to_cpup(p++);
+		if (bex.es != PNFS_BLOCK_READWRITE_DATA) {
+			dprintk("%s: incorrect extent state %d\n",
+				__func__, bex.es);
+			goto fail;
+		}
+
+		iomaps[i].offset = bex.foff;
+		iomaps[i].length = bex.len;
+	}
+
+	*iomapp = iomaps;
+	return nr_iomaps;
+fail:
+	kfree(iomaps);
+	return -EINVAL;
+}
+
+int
+nfsd4_scsi_decode_layoutupdate(__be32 *p, u32 len, struct iomap **iomapp,
+		u32 block_size)
+{
+	struct iomap *iomaps;
+	u32 nr_iomaps, expected, i;
+
+	if (len < sizeof(u32)) {
+		dprintk("%s: extent array too small: %u\n", __func__, len);
+		return -EINVAL;
+	}
+
+	nr_iomaps = be32_to_cpup(p++);
+	expected = sizeof(__be32) + nr_iomaps * PNFS_SCSI_RANGE_SIZE;
+	if (len != expected) {
+		dprintk("%s: extent array size mismatch: %u/%u\n",
+			__func__, len, expected);
+		return -EINVAL;
+	}
+
+	iomaps = kcalloc(nr_iomaps, sizeof(*iomaps), GFP_KERNEL);
+	if (!iomaps) {
+		dprintk("%s: failed to allocate extent array\n", __func__);
+		return -ENOMEM;
+	}
+
+	for (i = 0; i < nr_iomaps; i++) {
+		u64 val;
+
+		p = xdr_decode_hyper(p, &val);
+		if (val & (block_size - 1)) {
+			dprintk("%s: unaligned offset 0x%llx\n", __func__, val);
+			goto fail;
+		}
+		iomaps[i].offset = val;
+
+		p = xdr_decode_hyper(p, &val);
+		if (val & (block_size - 1)) {
+			dprintk("%s: unaligned length 0x%llx\n", __func__, val);
+			goto fail;
+		}
+		iomaps[i].length = val;
+	}
+
+	*iomapp = iomaps;
+	return nr_iomaps;
+fail:
+	kfree(iomaps);
+	return -EINVAL;
+}
diff --git a/fs/nfsd/blocklayoutxdr.h b/fs/nfsd/blocklayoutxdr.h
new file mode 100644
index 000000000..bc5166bfe
--- /dev/null
+++ b/fs/nfsd/blocklayoutxdr.h
@@ -0,0 +1,62 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _NFSD_BLOCKLAYOUTXDR_H
+#define _NFSD_BLOCKLAYOUTXDR_H 1
+
+#include <linux/blkdev.h>
+#include "xdr4.h"
+
+struct iomap;
+struct xdr_stream;
+
+struct pnfs_block_extent {
+	struct nfsd4_deviceid		vol_id;
+	u64				foff;
+	u64				len;
+	u64				soff;
+	enum pnfs_block_extent_state	es;
+};
+
+struct pnfs_block_range {
+	u64				foff;
+	u64				len;
+};
+
+/*
+ * Random upper cap for the uuid length to avoid unbounded allocation.
+ * Not actually limited by the protocol.
+ */
+#define PNFS_BLOCK_UUID_LEN	128
+
+struct pnfs_block_volume {
+	enum pnfs_block_volume_type	type;
+	union {
+		struct {
+			u64		offset;
+			u32		sig_len;
+			u8		sig[PNFS_BLOCK_UUID_LEN];
+		} simple;
+		struct {
+			enum scsi_code_set		code_set;
+			enum scsi_designator_type	designator_type;
+			int				designator_len;
+			u8				designator[256];
+			u64				pr_key;
+		} scsi;
+	};
+};
+
+struct pnfs_block_deviceaddr {
+	u32				nr_volumes;
+	struct pnfs_block_volume	volumes[];
+};
+
+__be32 nfsd4_block_encode_getdeviceinfo(struct xdr_stream *xdr,
+		struct nfsd4_getdeviceinfo *gdp);
+__be32 nfsd4_block_encode_layoutget(struct xdr_stream *xdr,
+		struct nfsd4_layoutget *lgp);
+int nfsd4_block_decode_layoutupdate(__be32 *p, u32 len, struct iomap **iomapp,
+		u32 block_size);
+int nfsd4_scsi_decode_layoutupdate(__be32 *p, u32 len, struct iomap **iomapp,
+		u32 block_size);
+
+#endif /* _NFSD_BLOCKLAYOUTXDR_H */
diff --git a/fs/nfsd/cache.h b/fs/nfsd/cache.h
new file mode 100644
index 000000000..65c331f75
--- /dev/null
+++ b/fs/nfsd/cache.h
@@ -0,0 +1,89 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Request reply cache. This was heavily inspired by the
+ * implementation in 4.3BSD/4.4BSD.
+ *
+ * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
+ */
+
+#ifndef NFSCACHE_H
+#define NFSCACHE_H
+
+#include <linux/sunrpc/svc.h>
+#include "netns.h"
+
+/*
+ * Representation of a reply cache entry.
+ *
+ * Note that we use a sockaddr_in6 to hold the address instead of the more
+ * typical sockaddr_storage. This is for space reasons, since sockaddr_storage
+ * is much larger than a sockaddr_in6.
+ */
+struct svc_cacherep {
+	struct {
+		/* Keep often-read xid, csum in the same cache line: */
+		__be32			k_xid;
+		__wsum			k_csum;
+		u32			k_proc;
+		u32			k_prot;
+		u32			k_vers;
+		unsigned int		k_len;
+		struct sockaddr_in6	k_addr;
+	} c_key;
+
+	struct rb_node		c_node;
+	struct list_head	c_lru;
+	unsigned char		c_state,	/* unused, inprog, done */
+				c_type,		/* status, buffer */
+				c_secure : 1;	/* req came from port < 1024 */
+	unsigned long		c_timestamp;
+	union {
+		struct kvec	u_vec;
+		__be32		u_status;
+	}			c_u;
+};
+
+#define c_replvec		c_u.u_vec
+#define c_replstat		c_u.u_status
+
+/* cache entry states */
+enum {
+	RC_UNUSED,
+	RC_INPROG,
+	RC_DONE
+};
+
+/* return values */
+enum {
+	RC_DROPIT,
+	RC_REPLY,
+	RC_DOIT
+};
+
+/*
+ * Cache types.
+ * We may want to add more types one day, e.g. for diropres and
+ * attrstat replies. Using cache entries with fixed length instead
+ * of buffer pointers may be more efficient.
+ */
+enum {
+	RC_NOCACHE,
+	RC_REPLSTAT,
+	RC_REPLBUFF,
+};
+
+/* Cache entries expire after this time period */
+#define RC_EXPIRE		(120 * HZ)
+
+/* Checksum this amount of the request */
+#define RC_CSUMLEN		(256U)
+
+int	nfsd_drc_slab_create(void);
+void	nfsd_drc_slab_free(void);
+int	nfsd_reply_cache_init(struct nfsd_net *);
+void	nfsd_reply_cache_shutdown(struct nfsd_net *);
+int	nfsd_cache_lookup(struct svc_rqst *);
+void	nfsd_cache_update(struct svc_rqst *, int, __be32 *);
+int	nfsd_reply_cache_stats_open(struct inode *, struct file *);
+
+#endif /* NFSCACHE_H */
diff --git a/fs/nfsd/current_stateid.h b/fs/nfsd/current_stateid.h
new file mode 100644
index 000000000..c28540d86
--- /dev/null
+++ b/fs/nfsd/current_stateid.h
@@ -0,0 +1,41 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _NFSD4_CURRENT_STATE_H
+#define _NFSD4_CURRENT_STATE_H
+
+#include "state.h"
+#include "xdr4.h"
+
+extern void clear_current_stateid(struct nfsd4_compound_state *cstate);
+/*
+ * functions to set current state id
+ */
+extern void nfsd4_set_opendowngradestateid(struct nfsd4_compound_state *,
+		union nfsd4_op_u *);
+extern void nfsd4_set_openstateid(struct nfsd4_compound_state *,
+		union nfsd4_op_u *);
+extern void nfsd4_set_lockstateid(struct nfsd4_compound_state *,
+		union nfsd4_op_u *);
+extern void nfsd4_set_closestateid(struct nfsd4_compound_state *,
+		union nfsd4_op_u *);
+
+/*
+ * functions to consume current state id
+ */
+extern void nfsd4_get_opendowngradestateid(struct nfsd4_compound_state *,
+		union nfsd4_op_u *);
+extern void nfsd4_get_delegreturnstateid(struct nfsd4_compound_state *,
+		union nfsd4_op_u *);
+extern void nfsd4_get_freestateid(struct nfsd4_compound_state *,
+		union nfsd4_op_u *);
+extern void nfsd4_get_setattrstateid(struct nfsd4_compound_state *,
+		union nfsd4_op_u *);
+extern void nfsd4_get_closestateid(struct nfsd4_compound_state *,
+		union nfsd4_op_u *);
+extern void nfsd4_get_lockustateid(struct nfsd4_compound_state *,
+		union nfsd4_op_u *);
+extern void nfsd4_get_readstateid(struct nfsd4_compound_state *,
+		union nfsd4_op_u *);
+extern void nfsd4_get_writestateid(struct nfsd4_compound_state *,
+		union nfsd4_op_u *);
+
+#endif   /* _NFSD4_CURRENT_STATE_H */
diff --git a/fs/nfsd/export.c b/fs/nfsd/export.c
new file mode 100644
index 000000000..21e404e7c
--- /dev/null
+++ b/fs/nfsd/export.c
@@ -0,0 +1,1329 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * NFS exporting and validation.
+ *
+ * We maintain a list of clients, each of which has a list of
+ * exports. To export an fs to a given client, you first have
+ * to create the client entry with NFSCTL_ADDCLIENT, which
+ * creates a client control block and adds it to the hash
+ * table. Then, you call NFSCTL_EXPORT for each fs.
+ *
+ *
+ * Copyright (C) 1995, 1996 Olaf Kirch, <okir@monad.swb.de>
+ */
+
+#include <linux/slab.h>
+#include <linux/namei.h>
+#include <linux/module.h>
+#include <linux/exportfs.h>
+#include <linux/sunrpc/svc_xprt.h>
+
+#include "nfsd.h"
+#include "nfsfh.h"
+#include "netns.h"
+#include "pnfs.h"
+#include "filecache.h"
+#include "trace.h"
+
+#define NFSDDBG_FACILITY	NFSDDBG_EXPORT
+
+/*
+ * We have two caches.
+ * One maps client+vfsmnt+dentry to export options - the export map
+ * The other maps client+filehandle-fragment to export options. - the expkey map
+ *
+ * The export options are actually stored in the first map, and the
+ * second map contains a reference to the entry in the first map.
+ */
+
+#define	EXPKEY_HASHBITS		8
+#define	EXPKEY_HASHMAX		(1 << EXPKEY_HASHBITS)
+#define	EXPKEY_HASHMASK		(EXPKEY_HASHMAX -1)
+
+static void expkey_put(struct kref *ref)
+{
+	struct svc_expkey *key = container_of(ref, struct svc_expkey, h.ref);
+
+	if (test_bit(CACHE_VALID, &key->h.flags) &&
+	    !test_bit(CACHE_NEGATIVE, &key->h.flags))
+		path_put(&key->ek_path);
+	auth_domain_put(key->ek_client);
+	kfree_rcu(key, ek_rcu);
+}
+
+static int expkey_upcall(struct cache_detail *cd, struct cache_head *h)
+{
+	return sunrpc_cache_pipe_upcall(cd, h);
+}
+
+static void expkey_request(struct cache_detail *cd,
+			   struct cache_head *h,
+			   char **bpp, int *blen)
+{
+	/* client fsidtype \xfsid */
+	struct svc_expkey *ek = container_of(h, struct svc_expkey, h);
+	char type[5];
+
+	qword_add(bpp, blen, ek->ek_client->name);
+	snprintf(type, 5, "%d", ek->ek_fsidtype);
+	qword_add(bpp, blen, type);
+	qword_addhex(bpp, blen, (char*)ek->ek_fsid, key_len(ek->ek_fsidtype));
+	(*bpp)[-1] = '\n';
+}
+
+static struct svc_expkey *svc_expkey_update(struct cache_detail *cd, struct svc_expkey *new,
+					    struct svc_expkey *old);
+static struct svc_expkey *svc_expkey_lookup(struct cache_detail *cd, struct svc_expkey *);
+
+static int expkey_parse(struct cache_detail *cd, char *mesg, int mlen)
+{
+	/* client fsidtype fsid expiry [path] */
+	char *buf;
+	int len;
+	struct auth_domain *dom = NULL;
+	int err;
+	int fsidtype;
+	char *ep;
+	struct svc_expkey key;
+	struct svc_expkey *ek = NULL;
+
+	if (mesg[mlen - 1] != '\n')
+		return -EINVAL;
+	mesg[mlen-1] = 0;
+
+	buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
+	err = -ENOMEM;
+	if (!buf)
+		goto out;
+
+	err = -EINVAL;
+	if ((len=qword_get(&mesg, buf, PAGE_SIZE)) <= 0)
+		goto out;
+
+	err = -ENOENT;
+	dom = auth_domain_find(buf);
+	if (!dom)
+		goto out;
+	dprintk("found domain %s\n", buf);
+
+	err = -EINVAL;
+	if ((len=qword_get(&mesg, buf, PAGE_SIZE)) <= 0)
+		goto out;
+	fsidtype = simple_strtoul(buf, &ep, 10);
+	if (*ep)
+		goto out;
+	dprintk("found fsidtype %d\n", fsidtype);
+	if (key_len(fsidtype)==0) /* invalid type */
+		goto out;
+	if ((len=qword_get(&mesg, buf, PAGE_SIZE)) <= 0)
+		goto out;
+	dprintk("found fsid length %d\n", len);
+	if (len != key_len(fsidtype))
+		goto out;
+
+	/* OK, we seem to have a valid key */
+	key.h.flags = 0;
+	key.h.expiry_time = get_expiry(&mesg);
+	if (key.h.expiry_time == 0)
+		goto out;
+
+	key.ek_client = dom;	
+	key.ek_fsidtype = fsidtype;
+	memcpy(key.ek_fsid, buf, len);
+
+	ek = svc_expkey_lookup(cd, &key);
+	err = -ENOMEM;
+	if (!ek)
+		goto out;
+
+	/* now we want a pathname, or empty meaning NEGATIVE  */
+	err = -EINVAL;
+	len = qword_get(&mesg, buf, PAGE_SIZE);
+	if (len < 0)
+		goto out;
+	dprintk("Path seems to be <%s>\n", buf);
+	err = 0;
+	if (len == 0) {
+		set_bit(CACHE_NEGATIVE, &key.h.flags);
+		ek = svc_expkey_update(cd, &key, ek);
+		if (ek)
+			trace_nfsd_expkey_update(ek, NULL);
+		else
+			err = -ENOMEM;
+	} else {
+		err = kern_path(buf, 0, &key.ek_path);
+		if (err)
+			goto out;
+
+		dprintk("Found the path %s\n", buf);
+
+		ek = svc_expkey_update(cd, &key, ek);
+		if (ek)
+			trace_nfsd_expkey_update(ek, buf);
+		else
+			err = -ENOMEM;
+		path_put(&key.ek_path);
+	}
+	cache_flush();
+ out:
+	if (ek)
+		cache_put(&ek->h, cd);
+	if (dom)
+		auth_domain_put(dom);
+	kfree(buf);
+	return err;
+}
+
+static int expkey_show(struct seq_file *m,
+		       struct cache_detail *cd,
+		       struct cache_head *h)
+{
+	struct svc_expkey *ek ;
+	int i;
+
+	if (h ==NULL) {
+		seq_puts(m, "#domain fsidtype fsid [path]\n");
+		return 0;
+	}
+	ek = container_of(h, struct svc_expkey, h);
+	seq_printf(m, "%s %d 0x", ek->ek_client->name,
+		   ek->ek_fsidtype);
+	for (i=0; i < key_len(ek->ek_fsidtype)/4; i++)
+		seq_printf(m, "%08x", ek->ek_fsid[i]);
+	if (test_bit(CACHE_VALID, &h->flags) && 
+	    !test_bit(CACHE_NEGATIVE, &h->flags)) {
+		seq_printf(m, " ");
+		seq_path(m, &ek->ek_path, "\\ \t\n");
+	}
+	seq_printf(m, "\n");
+	return 0;
+}
+
+static inline int expkey_match (struct cache_head *a, struct cache_head *b)
+{
+	struct svc_expkey *orig = container_of(a, struct svc_expkey, h);
+	struct svc_expkey *new = container_of(b, struct svc_expkey, h);
+
+	if (orig->ek_fsidtype != new->ek_fsidtype ||
+	    orig->ek_client != new->ek_client ||
+	    memcmp(orig->ek_fsid, new->ek_fsid, key_len(orig->ek_fsidtype)) != 0)
+		return 0;
+	return 1;
+}
+
+static inline void expkey_init(struct cache_head *cnew,
+				   struct cache_head *citem)
+{
+	struct svc_expkey *new = container_of(cnew, struct svc_expkey, h);
+	struct svc_expkey *item = container_of(citem, struct svc_expkey, h);
+
+	kref_get(&item->ek_client->ref);
+	new->ek_client = item->ek_client;
+	new->ek_fsidtype = item->ek_fsidtype;
+
+	memcpy(new->ek_fsid, item->ek_fsid, sizeof(new->ek_fsid));
+}
+
+static inline void expkey_update(struct cache_head *cnew,
+				   struct cache_head *citem)
+{
+	struct svc_expkey *new = container_of(cnew, struct svc_expkey, h);
+	struct svc_expkey *item = container_of(citem, struct svc_expkey, h);
+
+	new->ek_path = item->ek_path;
+	path_get(&item->ek_path);
+}
+
+static struct cache_head *expkey_alloc(void)
+{
+	struct svc_expkey *i = kmalloc(sizeof(*i), GFP_KERNEL);
+	if (i)
+		return &i->h;
+	else
+		return NULL;
+}
+
+static void expkey_flush(void)
+{
+	/*
+	 * Take the nfsd_mutex here to ensure that the file cache is not
+	 * destroyed while we're in the middle of flushing.
+	 */
+	mutex_lock(&nfsd_mutex);
+	nfsd_file_cache_purge(current->nsproxy->net_ns);
+	mutex_unlock(&nfsd_mutex);
+}
+
+static const struct cache_detail svc_expkey_cache_template = {
+	.owner		= THIS_MODULE,
+	.hash_size	= EXPKEY_HASHMAX,
+	.name		= "nfsd.fh",
+	.cache_put	= expkey_put,
+	.cache_upcall	= expkey_upcall,
+	.cache_request	= expkey_request,
+	.cache_parse	= expkey_parse,
+	.cache_show	= expkey_show,
+	.match		= expkey_match,
+	.init		= expkey_init,
+	.update       	= expkey_update,
+	.alloc		= expkey_alloc,
+	.flush		= expkey_flush,
+};
+
+static int
+svc_expkey_hash(struct svc_expkey *item)
+{
+	int hash = item->ek_fsidtype;
+	char * cp = (char*)item->ek_fsid;
+	int len = key_len(item->ek_fsidtype);
+
+	hash ^= hash_mem(cp, len, EXPKEY_HASHBITS);
+	hash ^= hash_ptr(item->ek_client, EXPKEY_HASHBITS);
+	hash &= EXPKEY_HASHMASK;
+	return hash;
+}
+
+static struct svc_expkey *
+svc_expkey_lookup(struct cache_detail *cd, struct svc_expkey *item)
+{
+	struct cache_head *ch;
+	int hash = svc_expkey_hash(item);
+
+	ch = sunrpc_cache_lookup_rcu(cd, &item->h, hash);
+	if (ch)
+		return container_of(ch, struct svc_expkey, h);
+	else
+		return NULL;
+}
+
+static struct svc_expkey *
+svc_expkey_update(struct cache_detail *cd, struct svc_expkey *new,
+		  struct svc_expkey *old)
+{
+	struct cache_head *ch;
+	int hash = svc_expkey_hash(new);
+
+	ch = sunrpc_cache_update(cd, &new->h, &old->h, hash);
+	if (ch)
+		return container_of(ch, struct svc_expkey, h);
+	else
+		return NULL;
+}
+
+
+#define	EXPORT_HASHBITS		8
+#define	EXPORT_HASHMAX		(1<< EXPORT_HASHBITS)
+
+static void nfsd4_fslocs_free(struct nfsd4_fs_locations *fsloc)
+{
+	struct nfsd4_fs_location *locations = fsloc->locations;
+	int i;
+
+	if (!locations)
+		return;
+
+	for (i = 0; i < fsloc->locations_count; i++) {
+		kfree(locations[i].path);
+		kfree(locations[i].hosts);
+	}
+
+	kfree(locations);
+	fsloc->locations = NULL;
+}
+
+static void svc_export_put(struct kref *ref)
+{
+	struct svc_export *exp = container_of(ref, struct svc_export, h.ref);
+	path_put(&exp->ex_path);
+	auth_domain_put(exp->ex_client);
+	nfsd4_fslocs_free(&exp->ex_fslocs);
+	kfree(exp->ex_uuid);
+	kfree_rcu(exp, ex_rcu);
+}
+
+static int svc_export_upcall(struct cache_detail *cd, struct cache_head *h)
+{
+	return sunrpc_cache_pipe_upcall(cd, h);
+}
+
+static void svc_export_request(struct cache_detail *cd,
+			       struct cache_head *h,
+			       char **bpp, int *blen)
+{
+	/*  client path */
+	struct svc_export *exp = container_of(h, struct svc_export, h);
+	char *pth;
+
+	qword_add(bpp, blen, exp->ex_client->name);
+	pth = d_path(&exp->ex_path, *bpp, *blen);
+	if (IS_ERR(pth)) {
+		/* is this correct? */
+		(*bpp)[0] = '\n';
+		return;
+	}
+	qword_add(bpp, blen, pth);
+	(*bpp)[-1] = '\n';
+}
+
+static struct svc_export *svc_export_update(struct svc_export *new,
+					    struct svc_export *old);
+static struct svc_export *svc_export_lookup(struct svc_export *);
+
+static int check_export(struct inode *inode, int *flags, unsigned char *uuid)
+{
+
+	/*
+	 * We currently export only dirs, regular files, and (for v4
+	 * pseudoroot) symlinks.
+	 */
+	if (!S_ISDIR(inode->i_mode) &&
+	    !S_ISLNK(inode->i_mode) &&
+	    !S_ISREG(inode->i_mode))
+		return -ENOTDIR;
+
+	/*
+	 * Mountd should never pass down a writeable V4ROOT export, but,
+	 * just to make sure:
+	 */
+	if (*flags & NFSEXP_V4ROOT)
+		*flags |= NFSEXP_READONLY;
+
+	/* There are two requirements on a filesystem to be exportable.
+	 * 1:  We must be able to identify the filesystem from a number.
+	 *       either a device number (so FS_REQUIRES_DEV needed)
+	 *       or an FSID number (so NFSEXP_FSID or ->uuid is needed).
+	 * 2:  We must be able to find an inode from a filehandle.
+	 *       This means that s_export_op must be set.
+	 */
+	if (!(inode->i_sb->s_type->fs_flags & FS_REQUIRES_DEV) &&
+	    !(*flags & NFSEXP_FSID) &&
+	    uuid == NULL) {
+		dprintk("exp_export: export of non-dev fs without fsid\n");
+		return -EINVAL;
+	}
+
+	if (!inode->i_sb->s_export_op ||
+	    !inode->i_sb->s_export_op->fh_to_dentry) {
+		dprintk("exp_export: export of invalid fs type.\n");
+		return -EINVAL;
+	}
+
+	return 0;
+
+}
+
+#ifdef CONFIG_NFSD_V4
+
+static int
+fsloc_parse(char **mesg, char *buf, struct nfsd4_fs_locations *fsloc)
+{
+	int len;
+	int migrated, i, err;
+
+	/* more than one fsloc */
+	if (fsloc->locations)
+		return -EINVAL;
+
+	/* listsize */
+	err = get_uint(mesg, &fsloc->locations_count);
+	if (err)
+		return err;
+	if (fsloc->locations_count > MAX_FS_LOCATIONS)
+		return -EINVAL;
+	if (fsloc->locations_count == 0)
+		return 0;
+
+	fsloc->locations = kcalloc(fsloc->locations_count,
+				   sizeof(struct nfsd4_fs_location),
+				   GFP_KERNEL);
+	if (!fsloc->locations)
+		return -ENOMEM;
+	for (i=0; i < fsloc->locations_count; i++) {
+		/* colon separated host list */
+		err = -EINVAL;
+		len = qword_get(mesg, buf, PAGE_SIZE);
+		if (len <= 0)
+			goto out_free_all;
+		err = -ENOMEM;
+		fsloc->locations[i].hosts = kstrdup(buf, GFP_KERNEL);
+		if (!fsloc->locations[i].hosts)
+			goto out_free_all;
+		err = -EINVAL;
+		/* slash separated path component list */
+		len = qword_get(mesg, buf, PAGE_SIZE);
+		if (len <= 0)
+			goto out_free_all;
+		err = -ENOMEM;
+		fsloc->locations[i].path = kstrdup(buf, GFP_KERNEL);
+		if (!fsloc->locations[i].path)
+			goto out_free_all;
+	}
+	/* migrated */
+	err = get_int(mesg, &migrated);
+	if (err)
+		goto out_free_all;
+	err = -EINVAL;
+	if (migrated < 0 || migrated > 1)
+		goto out_free_all;
+	fsloc->migrated = migrated;
+	return 0;
+out_free_all:
+	nfsd4_fslocs_free(fsloc);
+	return err;
+}
+
+static int secinfo_parse(char **mesg, char *buf, struct svc_export *exp)
+{
+	struct exp_flavor_info *f;
+	u32 listsize;
+	int err;
+
+	/* more than one secinfo */
+	if (exp->ex_nflavors)
+		return -EINVAL;
+
+	err = get_uint(mesg, &listsize);
+	if (err)
+		return err;
+	if (listsize > MAX_SECINFO_LIST)
+		return -EINVAL;
+
+	for (f = exp->ex_flavors; f < exp->ex_flavors + listsize; f++) {
+		err = get_uint(mesg, &f->pseudoflavor);
+		if (err)
+			return err;
+		/*
+		 * XXX: It would be nice to also check whether this
+		 * pseudoflavor is supported, so we can discover the
+		 * problem at export time instead of when a client fails
+		 * to authenticate.
+		 */
+		err = get_uint(mesg, &f->flags);
+		if (err)
+			return err;
+		/* Only some flags are allowed to differ between flavors: */
+		if (~NFSEXP_SECINFO_FLAGS & (f->flags ^ exp->ex_flags))
+			return -EINVAL;
+	}
+	exp->ex_nflavors = listsize;
+	return 0;
+}
+
+#else /* CONFIG_NFSD_V4 */
+static inline int
+fsloc_parse(char **mesg, char *buf, struct nfsd4_fs_locations *fsloc){return 0;}
+static inline int
+secinfo_parse(char **mesg, char *buf, struct svc_export *exp) { return 0; }
+#endif
+
+static inline int
+nfsd_uuid_parse(char **mesg, char *buf, unsigned char **puuid)
+{
+	int len;
+
+	/* more than one uuid */
+	if (*puuid)
+		return -EINVAL;
+
+	/* expect a 16 byte uuid encoded as \xXXXX... */
+	len = qword_get(mesg, buf, PAGE_SIZE);
+	if (len != EX_UUID_LEN)
+		return -EINVAL;
+
+	*puuid = kmemdup(buf, EX_UUID_LEN, GFP_KERNEL);
+	if (*puuid == NULL)
+		return -ENOMEM;
+
+	return 0;
+}
+
+static int svc_export_parse(struct cache_detail *cd, char *mesg, int mlen)
+{
+	/* client path expiry [flags anonuid anongid fsid] */
+	char *buf;
+	int len;
+	int err;
+	struct auth_domain *dom = NULL;
+	struct svc_export exp = {}, *expp;
+	int an_int;
+
+	if (mesg[mlen-1] != '\n')
+		return -EINVAL;
+	mesg[mlen-1] = 0;
+
+	buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	/* client */
+	err = -EINVAL;
+	len = qword_get(&mesg, buf, PAGE_SIZE);
+	if (len <= 0)
+		goto out;
+
+	err = -ENOENT;
+	dom = auth_domain_find(buf);
+	if (!dom)
+		goto out;
+
+	/* path */
+	err = -EINVAL;
+	if ((len = qword_get(&mesg, buf, PAGE_SIZE)) <= 0)
+		goto out1;
+
+	err = kern_path(buf, 0, &exp.ex_path);
+	if (err)
+		goto out1;
+
+	exp.ex_client = dom;
+	exp.cd = cd;
+	exp.ex_devid_map = NULL;
+
+	/* expiry */
+	err = -EINVAL;
+	exp.h.expiry_time = get_expiry(&mesg);
+	if (exp.h.expiry_time == 0)
+		goto out3;
+
+	/* flags */
+	err = get_int(&mesg, &an_int);
+	if (err == -ENOENT) {
+		err = 0;
+		set_bit(CACHE_NEGATIVE, &exp.h.flags);
+	} else {
+		if (err || an_int < 0)
+			goto out3;
+		exp.ex_flags= an_int;
+	
+		/* anon uid */
+		err = get_int(&mesg, &an_int);
+		if (err)
+			goto out3;
+		exp.ex_anon_uid= make_kuid(current_user_ns(), an_int);
+
+		/* anon gid */
+		err = get_int(&mesg, &an_int);
+		if (err)
+			goto out3;
+		exp.ex_anon_gid= make_kgid(current_user_ns(), an_int);
+
+		/* fsid */
+		err = get_int(&mesg, &an_int);
+		if (err)
+			goto out3;
+		exp.ex_fsid = an_int;
+
+		while ((len = qword_get(&mesg, buf, PAGE_SIZE)) > 0) {
+			if (strcmp(buf, "fsloc") == 0)
+				err = fsloc_parse(&mesg, buf, &exp.ex_fslocs);
+			else if (strcmp(buf, "uuid") == 0)
+				err = nfsd_uuid_parse(&mesg, buf, &exp.ex_uuid);
+			else if (strcmp(buf, "secinfo") == 0)
+				err = secinfo_parse(&mesg, buf, &exp);
+			else
+				/* quietly ignore unknown words and anything
+				 * following. Newer user-space can try to set
+				 * new values, then see what the result was.
+				 */
+				break;
+			if (err)
+				goto out4;
+		}
+
+		err = check_export(d_inode(exp.ex_path.dentry), &exp.ex_flags,
+				   exp.ex_uuid);
+		if (err)
+			goto out4;
+		/*
+		 * No point caching this if it would immediately expire.
+		 * Also, this protects exportfs's dummy export from the
+		 * anon_uid/anon_gid checks:
+		 */
+		if (exp.h.expiry_time < seconds_since_boot())
+			goto out4;
+		/*
+		 * For some reason exportfs has been passing down an
+		 * invalid (-1) uid & gid on the "dummy" export which it
+		 * uses to test export support.  To make sure exportfs
+		 * sees errors from check_export we therefore need to
+		 * delay these checks till after check_export:
+		 */
+		err = -EINVAL;
+		if (!uid_valid(exp.ex_anon_uid))
+			goto out4;
+		if (!gid_valid(exp.ex_anon_gid))
+			goto out4;
+		err = 0;
+
+		nfsd4_setup_layout_type(&exp);
+	}
+
+	expp = svc_export_lookup(&exp);
+	if (!expp) {
+		err = -ENOMEM;
+		goto out4;
+	}
+	expp = svc_export_update(&exp, expp);
+	if (expp) {
+		trace_nfsd_export_update(expp);
+		cache_flush();
+		exp_put(expp);
+	} else
+		err = -ENOMEM;
+out4:
+	nfsd4_fslocs_free(&exp.ex_fslocs);
+	kfree(exp.ex_uuid);
+out3:
+	path_put(&exp.ex_path);
+out1:
+	auth_domain_put(dom);
+out:
+	kfree(buf);
+	return err;
+}
+
+static void exp_flags(struct seq_file *m, int flag, int fsid,
+		kuid_t anonu, kgid_t anong, struct nfsd4_fs_locations *fslocs);
+static void show_secinfo(struct seq_file *m, struct svc_export *exp);
+
+static int svc_export_show(struct seq_file *m,
+			   struct cache_detail *cd,
+			   struct cache_head *h)
+{
+	struct svc_export *exp ;
+
+	if (h ==NULL) {
+		seq_puts(m, "#path domain(flags)\n");
+		return 0;
+	}
+	exp = container_of(h, struct svc_export, h);
+	seq_path(m, &exp->ex_path, " \t\n\\");
+	seq_putc(m, '\t');
+	seq_escape(m, exp->ex_client->name, " \t\n\\");
+	seq_putc(m, '(');
+	if (test_bit(CACHE_VALID, &h->flags) && 
+	    !test_bit(CACHE_NEGATIVE, &h->flags)) {
+		exp_flags(m, exp->ex_flags, exp->ex_fsid,
+			  exp->ex_anon_uid, exp->ex_anon_gid, &exp->ex_fslocs);
+		if (exp->ex_uuid) {
+			int i;
+			seq_puts(m, ",uuid=");
+			for (i = 0; i < EX_UUID_LEN; i++) {
+				if ((i&3) == 0 && i)
+					seq_putc(m, ':');
+				seq_printf(m, "%02x", exp->ex_uuid[i]);
+			}
+		}
+		show_secinfo(m, exp);
+	}
+	seq_puts(m, ")\n");
+	return 0;
+}
+static int svc_export_match(struct cache_head *a, struct cache_head *b)
+{
+	struct svc_export *orig = container_of(a, struct svc_export, h);
+	struct svc_export *new = container_of(b, struct svc_export, h);
+	return orig->ex_client == new->ex_client &&
+		path_equal(&orig->ex_path, &new->ex_path);
+}
+
+static void svc_export_init(struct cache_head *cnew, struct cache_head *citem)
+{
+	struct svc_export *new = container_of(cnew, struct svc_export, h);
+	struct svc_export *item = container_of(citem, struct svc_export, h);
+
+	kref_get(&item->ex_client->ref);
+	new->ex_client = item->ex_client;
+	new->ex_path = item->ex_path;
+	path_get(&item->ex_path);
+	new->ex_fslocs.locations = NULL;
+	new->ex_fslocs.locations_count = 0;
+	new->ex_fslocs.migrated = 0;
+	new->ex_layout_types = 0;
+	new->ex_uuid = NULL;
+	new->cd = item->cd;
+}
+
+static void export_update(struct cache_head *cnew, struct cache_head *citem)
+{
+	struct svc_export *new = container_of(cnew, struct svc_export, h);
+	struct svc_export *item = container_of(citem, struct svc_export, h);
+	int i;
+
+	new->ex_flags = item->ex_flags;
+	new->ex_anon_uid = item->ex_anon_uid;
+	new->ex_anon_gid = item->ex_anon_gid;
+	new->ex_fsid = item->ex_fsid;
+	new->ex_devid_map = item->ex_devid_map;
+	item->ex_devid_map = NULL;
+	new->ex_uuid = item->ex_uuid;
+	item->ex_uuid = NULL;
+	new->ex_fslocs.locations = item->ex_fslocs.locations;
+	item->ex_fslocs.locations = NULL;
+	new->ex_fslocs.locations_count = item->ex_fslocs.locations_count;
+	item->ex_fslocs.locations_count = 0;
+	new->ex_fslocs.migrated = item->ex_fslocs.migrated;
+	item->ex_fslocs.migrated = 0;
+	new->ex_layout_types = item->ex_layout_types;
+	new->ex_nflavors = item->ex_nflavors;
+	for (i = 0; i < MAX_SECINFO_LIST; i++) {
+		new->ex_flavors[i] = item->ex_flavors[i];
+	}
+}
+
+static struct cache_head *svc_export_alloc(void)
+{
+	struct svc_export *i = kmalloc(sizeof(*i), GFP_KERNEL);
+	if (i)
+		return &i->h;
+	else
+		return NULL;
+}
+
+static const struct cache_detail svc_export_cache_template = {
+	.owner		= THIS_MODULE,
+	.hash_size	= EXPORT_HASHMAX,
+	.name		= "nfsd.export",
+	.cache_put	= svc_export_put,
+	.cache_upcall	= svc_export_upcall,
+	.cache_request	= svc_export_request,
+	.cache_parse	= svc_export_parse,
+	.cache_show	= svc_export_show,
+	.match		= svc_export_match,
+	.init		= svc_export_init,
+	.update		= export_update,
+	.alloc		= svc_export_alloc,
+};
+
+static int
+svc_export_hash(struct svc_export *exp)
+{
+	int hash;
+
+	hash = hash_ptr(exp->ex_client, EXPORT_HASHBITS);
+	hash ^= hash_ptr(exp->ex_path.dentry, EXPORT_HASHBITS);
+	hash ^= hash_ptr(exp->ex_path.mnt, EXPORT_HASHBITS);
+	return hash;
+}
+
+static struct svc_export *
+svc_export_lookup(struct svc_export *exp)
+{
+	struct cache_head *ch;
+	int hash = svc_export_hash(exp);
+
+	ch = sunrpc_cache_lookup_rcu(exp->cd, &exp->h, hash);
+	if (ch)
+		return container_of(ch, struct svc_export, h);
+	else
+		return NULL;
+}
+
+static struct svc_export *
+svc_export_update(struct svc_export *new, struct svc_export *old)
+{
+	struct cache_head *ch;
+	int hash = svc_export_hash(old);
+
+	ch = sunrpc_cache_update(old->cd, &new->h, &old->h, hash);
+	if (ch)
+		return container_of(ch, struct svc_export, h);
+	else
+		return NULL;
+}
+
+
+static struct svc_expkey *
+exp_find_key(struct cache_detail *cd, struct auth_domain *clp, int fsid_type,
+	     u32 *fsidv, struct cache_req *reqp)
+{
+	struct svc_expkey key, *ek;
+	int err;
+	
+	if (!clp)
+		return ERR_PTR(-ENOENT);
+
+	key.ek_client = clp;
+	key.ek_fsidtype = fsid_type;
+	memcpy(key.ek_fsid, fsidv, key_len(fsid_type));
+
+	ek = svc_expkey_lookup(cd, &key);
+	if (ek == NULL)
+		return ERR_PTR(-ENOMEM);
+	err = cache_check(cd, &ek->h, reqp);
+	if (err) {
+		trace_nfsd_exp_find_key(&key, err);
+		return ERR_PTR(err);
+	}
+	return ek;
+}
+
+static struct svc_export *
+exp_get_by_name(struct cache_detail *cd, struct auth_domain *clp,
+		const struct path *path, struct cache_req *reqp)
+{
+	struct svc_export *exp, key;
+	int err;
+
+	if (!clp)
+		return ERR_PTR(-ENOENT);
+
+	key.ex_client = clp;
+	key.ex_path = *path;
+	key.cd = cd;
+
+	exp = svc_export_lookup(&key);
+	if (exp == NULL)
+		return ERR_PTR(-ENOMEM);
+	err = cache_check(cd, &exp->h, reqp);
+	if (err) {
+		trace_nfsd_exp_get_by_name(&key, err);
+		return ERR_PTR(err);
+	}
+	return exp;
+}
+
+/*
+ * Find the export entry for a given dentry.
+ */
+static struct svc_export *
+exp_parent(struct cache_detail *cd, struct auth_domain *clp, struct path *path)
+{
+	struct dentry *saved = dget(path->dentry);
+	struct svc_export *exp = exp_get_by_name(cd, clp, path, NULL);
+
+	while (PTR_ERR(exp) == -ENOENT && !IS_ROOT(path->dentry)) {
+		struct dentry *parent = dget_parent(path->dentry);
+		dput(path->dentry);
+		path->dentry = parent;
+		exp = exp_get_by_name(cd, clp, path, NULL);
+	}
+	dput(path->dentry);
+	path->dentry = saved;
+	return exp;
+}
+
+
+
+/*
+ * Obtain the root fh on behalf of a client.
+ * This could be done in user space, but I feel that it adds some safety
+ * since its harder to fool a kernel module than a user space program.
+ */
+int
+exp_rootfh(struct net *net, struct auth_domain *clp, char *name,
+	   struct knfsd_fh *f, int maxsize)
+{
+	struct svc_export	*exp;
+	struct path		path;
+	struct inode		*inode;
+	struct svc_fh		fh;
+	int			err;
+	struct nfsd_net		*nn = net_generic(net, nfsd_net_id);
+	struct cache_detail	*cd = nn->svc_export_cache;
+
+	err = -EPERM;
+	/* NB: we probably ought to check that it's NUL-terminated */
+	if (kern_path(name, 0, &path)) {
+		printk("nfsd: exp_rootfh path not found %s", name);
+		return err;
+	}
+	inode = d_inode(path.dentry);
+
+	dprintk("nfsd: exp_rootfh(%s [%p] %s:%s/%ld)\n",
+		 name, path.dentry, clp->name,
+		 inode->i_sb->s_id, inode->i_ino);
+	exp = exp_parent(cd, clp, &path);
+	if (IS_ERR(exp)) {
+		err = PTR_ERR(exp);
+		goto out;
+	}
+
+	/*
+	 * fh must be initialized before calling fh_compose
+	 */
+	fh_init(&fh, maxsize);
+	if (fh_compose(&fh, exp, path.dentry, NULL))
+		err = -EINVAL;
+	else
+		err = 0;
+	memcpy(f, &fh.fh_handle, sizeof(struct knfsd_fh));
+	fh_put(&fh);
+	exp_put(exp);
+out:
+	path_put(&path);
+	return err;
+}
+
+static struct svc_export *exp_find(struct cache_detail *cd,
+				   struct auth_domain *clp, int fsid_type,
+				   u32 *fsidv, struct cache_req *reqp)
+{
+	struct svc_export *exp;
+	struct nfsd_net *nn = net_generic(cd->net, nfsd_net_id);
+	struct svc_expkey *ek = exp_find_key(nn->svc_expkey_cache, clp, fsid_type, fsidv, reqp);
+	if (IS_ERR(ek))
+		return ERR_CAST(ek);
+
+	exp = exp_get_by_name(cd, clp, &ek->ek_path, reqp);
+	cache_put(&ek->h, nn->svc_expkey_cache);
+
+	if (IS_ERR(exp))
+		return ERR_CAST(exp);
+	return exp;
+}
+
+__be32 check_nfsd_access(struct svc_export *exp, struct svc_rqst *rqstp)
+{
+	struct exp_flavor_info *f;
+	struct exp_flavor_info *end = exp->ex_flavors + exp->ex_nflavors;
+
+	/* legacy gss-only clients are always OK: */
+	if (exp->ex_client == rqstp->rq_gssclient)
+		return 0;
+	/* ip-address based client; check sec= export option: */
+	for (f = exp->ex_flavors; f < end; f++) {
+		if (f->pseudoflavor == rqstp->rq_cred.cr_flavor)
+			return 0;
+	}
+	/* defaults in absence of sec= options: */
+	if (exp->ex_nflavors == 0) {
+		if (rqstp->rq_cred.cr_flavor == RPC_AUTH_NULL ||
+		    rqstp->rq_cred.cr_flavor == RPC_AUTH_UNIX)
+			return 0;
+	}
+
+	/* If the compound op contains a spo_must_allowed op,
+	 * it will be sent with integrity/protection which
+	 * will have to be expressly allowed on mounts that
+	 * don't support it
+	 */
+
+	if (nfsd4_spo_must_allow(rqstp))
+		return 0;
+
+	return rqstp->rq_vers < 4 ? nfserr_acces : nfserr_wrongsec;
+}
+
+/*
+ * Uses rq_client and rq_gssclient to find an export; uses rq_client (an
+ * auth_unix client) if it's available and has secinfo information;
+ * otherwise, will try to use rq_gssclient.
+ *
+ * Called from functions that handle requests; functions that do work on
+ * behalf of mountd are passed a single client name to use, and should
+ * use exp_get_by_name() or exp_find().
+ */
+struct svc_export *
+rqst_exp_get_by_name(struct svc_rqst *rqstp, struct path *path)
+{
+	struct svc_export *gssexp, *exp = ERR_PTR(-ENOENT);
+	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+	struct cache_detail *cd = nn->svc_export_cache;
+
+	if (rqstp->rq_client == NULL)
+		goto gss;
+
+	/* First try the auth_unix client: */
+	exp = exp_get_by_name(cd, rqstp->rq_client, path, &rqstp->rq_chandle);
+	if (PTR_ERR(exp) == -ENOENT)
+		goto gss;
+	if (IS_ERR(exp))
+		return exp;
+	/* If it has secinfo, assume there are no gss/... clients */
+	if (exp->ex_nflavors > 0)
+		return exp;
+gss:
+	/* Otherwise, try falling back on gss client */
+	if (rqstp->rq_gssclient == NULL)
+		return exp;
+	gssexp = exp_get_by_name(cd, rqstp->rq_gssclient, path, &rqstp->rq_chandle);
+	if (PTR_ERR(gssexp) == -ENOENT)
+		return exp;
+	if (!IS_ERR(exp))
+		exp_put(exp);
+	return gssexp;
+}
+
+struct svc_export *
+rqst_exp_find(struct svc_rqst *rqstp, int fsid_type, u32 *fsidv)
+{
+	struct svc_export *gssexp, *exp = ERR_PTR(-ENOENT);
+	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+	struct cache_detail *cd = nn->svc_export_cache;
+
+	if (rqstp->rq_client == NULL)
+		goto gss;
+
+	/* First try the auth_unix client: */
+	exp = exp_find(cd, rqstp->rq_client, fsid_type,
+		       fsidv, &rqstp->rq_chandle);
+	if (PTR_ERR(exp) == -ENOENT)
+		goto gss;
+	if (IS_ERR(exp))
+		return exp;
+	/* If it has secinfo, assume there are no gss/... clients */
+	if (exp->ex_nflavors > 0)
+		return exp;
+gss:
+	/* Otherwise, try falling back on gss client */
+	if (rqstp->rq_gssclient == NULL)
+		return exp;
+	gssexp = exp_find(cd, rqstp->rq_gssclient, fsid_type, fsidv,
+						&rqstp->rq_chandle);
+	if (PTR_ERR(gssexp) == -ENOENT)
+		return exp;
+	if (!IS_ERR(exp))
+		exp_put(exp);
+	return gssexp;
+}
+
+struct svc_export *
+rqst_exp_parent(struct svc_rqst *rqstp, struct path *path)
+{
+	struct dentry *saved = dget(path->dentry);
+	struct svc_export *exp = rqst_exp_get_by_name(rqstp, path);
+
+	while (PTR_ERR(exp) == -ENOENT && !IS_ROOT(path->dentry)) {
+		struct dentry *parent = dget_parent(path->dentry);
+		dput(path->dentry);
+		path->dentry = parent;
+		exp = rqst_exp_get_by_name(rqstp, path);
+	}
+	dput(path->dentry);
+	path->dentry = saved;
+	return exp;
+}
+
+struct svc_export *rqst_find_fsidzero_export(struct svc_rqst *rqstp)
+{
+	u32 fsidv[2];
+
+	mk_fsid(FSID_NUM, fsidv, 0, 0, 0, NULL);
+
+	return rqst_exp_find(rqstp, FSID_NUM, fsidv);
+}
+
+/*
+ * Called when we need the filehandle for the root of the pseudofs,
+ * for a given NFSv4 client.   The root is defined to be the
+ * export point with fsid==0
+ */
+__be32
+exp_pseudoroot(struct svc_rqst *rqstp, struct svc_fh *fhp)
+{
+	struct svc_export *exp;
+	__be32 rv;
+
+	exp = rqst_find_fsidzero_export(rqstp);
+	if (IS_ERR(exp))
+		return nfserrno(PTR_ERR(exp));
+	rv = fh_compose(fhp, exp, exp->ex_path.dentry, NULL);
+	exp_put(exp);
+	return rv;
+}
+
+static struct flags {
+	int flag;
+	char *name[2];
+} expflags[] = {
+	{ NFSEXP_READONLY, {"ro", "rw"}},
+	{ NFSEXP_INSECURE_PORT, {"insecure", ""}},
+	{ NFSEXP_ROOTSQUASH, {"root_squash", "no_root_squash"}},
+	{ NFSEXP_ALLSQUASH, {"all_squash", ""}},
+	{ NFSEXP_ASYNC, {"async", "sync"}},
+	{ NFSEXP_GATHERED_WRITES, {"wdelay", "no_wdelay"}},
+	{ NFSEXP_NOREADDIRPLUS, {"nordirplus", ""}},
+	{ NFSEXP_NOHIDE, {"nohide", ""}},
+	{ NFSEXP_CROSSMOUNT, {"crossmnt", ""}},
+	{ NFSEXP_NOSUBTREECHECK, {"no_subtree_check", ""}},
+	{ NFSEXP_NOAUTHNLM, {"insecure_locks", ""}},
+	{ NFSEXP_V4ROOT, {"v4root", ""}},
+	{ NFSEXP_PNFS, {"pnfs", ""}},
+	{ NFSEXP_SECURITY_LABEL, {"security_label", ""}},
+	{ 0, {"", ""}}
+};
+
+static void show_expflags(struct seq_file *m, int flags, int mask)
+{
+	struct flags *flg;
+	int state, first = 0;
+
+	for (flg = expflags; flg->flag; flg++) {
+		if (flg->flag & ~mask)
+			continue;
+		state = (flg->flag & flags) ? 0 : 1;
+		if (*flg->name[state])
+			seq_printf(m, "%s%s", first++?",":"", flg->name[state]);
+	}
+}
+
+static void show_secinfo_flags(struct seq_file *m, int flags)
+{
+	seq_printf(m, ",");
+	show_expflags(m, flags, NFSEXP_SECINFO_FLAGS);
+}
+
+static bool secinfo_flags_equal(int f, int g)
+{
+	f &= NFSEXP_SECINFO_FLAGS;
+	g &= NFSEXP_SECINFO_FLAGS;
+	return f == g;
+}
+
+static int show_secinfo_run(struct seq_file *m, struct exp_flavor_info **fp, struct exp_flavor_info *end)
+{
+	int flags;
+
+	flags = (*fp)->flags;
+	seq_printf(m, ",sec=%d", (*fp)->pseudoflavor);
+	(*fp)++;
+	while (*fp != end && secinfo_flags_equal(flags, (*fp)->flags)) {
+		seq_printf(m, ":%d", (*fp)->pseudoflavor);
+		(*fp)++;
+	}
+	return flags;
+}
+
+static void show_secinfo(struct seq_file *m, struct svc_export *exp)
+{
+	struct exp_flavor_info *f;
+	struct exp_flavor_info *end = exp->ex_flavors + exp->ex_nflavors;
+	int flags;
+
+	if (exp->ex_nflavors == 0)
+		return;
+	f = exp->ex_flavors;
+	flags = show_secinfo_run(m, &f, end);
+	if (!secinfo_flags_equal(flags, exp->ex_flags))
+		show_secinfo_flags(m, flags);
+	while (f != end) {
+		flags = show_secinfo_run(m, &f, end);
+		show_secinfo_flags(m, flags);
+	}
+}
+
+static void exp_flags(struct seq_file *m, int flag, int fsid,
+		kuid_t anonu, kgid_t anong, struct nfsd4_fs_locations *fsloc)
+{
+	struct user_namespace *userns = m->file->f_cred->user_ns;
+
+	show_expflags(m, flag, NFSEXP_ALLFLAGS);
+	if (flag & NFSEXP_FSID)
+		seq_printf(m, ",fsid=%d", fsid);
+	if (!uid_eq(anonu, make_kuid(userns, (uid_t)-2)) &&
+	    !uid_eq(anonu, make_kuid(userns, 0x10000-2)))
+		seq_printf(m, ",anonuid=%u", from_kuid_munged(userns, anonu));
+	if (!gid_eq(anong, make_kgid(userns, (gid_t)-2)) &&
+	    !gid_eq(anong, make_kgid(userns, 0x10000-2)))
+		seq_printf(m, ",anongid=%u", from_kgid_munged(userns, anong));
+	if (fsloc && fsloc->locations_count > 0) {
+		char *loctype = (fsloc->migrated) ? "refer" : "replicas";
+		int i;
+
+		seq_printf(m, ",%s=", loctype);
+		seq_escape(m, fsloc->locations[0].path, ",;@ \t\n\\");
+		seq_putc(m, '@');
+		seq_escape(m, fsloc->locations[0].hosts, ",;@ \t\n\\");
+		for (i = 1; i < fsloc->locations_count; i++) {
+			seq_putc(m, ';');
+			seq_escape(m, fsloc->locations[i].path, ",;@ \t\n\\");
+			seq_putc(m, '@');
+			seq_escape(m, fsloc->locations[i].hosts, ",;@ \t\n\\");
+		}
+	}
+}
+
+static int e_show(struct seq_file *m, void *p)
+{
+	struct cache_head *cp = p;
+	struct svc_export *exp = container_of(cp, struct svc_export, h);
+	struct cache_detail *cd = m->private;
+
+	if (p == SEQ_START_TOKEN) {
+		seq_puts(m, "# Version 1.1\n");
+		seq_puts(m, "# Path Client(Flags) # IPs\n");
+		return 0;
+	}
+
+	exp_get(exp);
+	if (cache_check(cd, &exp->h, NULL))
+		return 0;
+	exp_put(exp);
+	return svc_export_show(m, cd, cp);
+}
+
+const struct seq_operations nfs_exports_op = {
+	.start	= cache_seq_start_rcu,
+	.next	= cache_seq_next_rcu,
+	.stop	= cache_seq_stop_rcu,
+	.show	= e_show,
+};
+
+/*
+ * Initialize the exports module.
+ */
+int
+nfsd_export_init(struct net *net)
+{
+	int rv;
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	dprintk("nfsd: initializing export module (net: %x).\n", net->ns.inum);
+
+	nn->svc_export_cache = cache_create_net(&svc_export_cache_template, net);
+	if (IS_ERR(nn->svc_export_cache))
+		return PTR_ERR(nn->svc_export_cache);
+	rv = cache_register_net(nn->svc_export_cache, net);
+	if (rv)
+		goto destroy_export_cache;
+
+	nn->svc_expkey_cache = cache_create_net(&svc_expkey_cache_template, net);
+	if (IS_ERR(nn->svc_expkey_cache)) {
+		rv = PTR_ERR(nn->svc_expkey_cache);
+		goto unregister_export_cache;
+	}
+	rv = cache_register_net(nn->svc_expkey_cache, net);
+	if (rv)
+		goto destroy_expkey_cache;
+	return 0;
+
+destroy_expkey_cache:
+	cache_destroy_net(nn->svc_expkey_cache, net);
+unregister_export_cache:
+	cache_unregister_net(nn->svc_export_cache, net);
+destroy_export_cache:
+	cache_destroy_net(nn->svc_export_cache, net);
+	return rv;
+}
+
+/*
+ * Flush exports table - called when last nfsd thread is killed
+ */
+void
+nfsd_export_flush(struct net *net)
+{
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	cache_purge(nn->svc_expkey_cache);
+	cache_purge(nn->svc_export_cache);
+}
+
+/*
+ * Shutdown the exports module.
+ */
+void
+nfsd_export_shutdown(struct net *net)
+{
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	dprintk("nfsd: shutting down export module (net: %x).\n", net->ns.inum);
+
+	cache_unregister_net(nn->svc_expkey_cache, net);
+	cache_unregister_net(nn->svc_export_cache, net);
+	cache_destroy_net(nn->svc_expkey_cache, net);
+	cache_destroy_net(nn->svc_export_cache, net);
+	svcauth_unix_purge(net);
+
+	dprintk("nfsd: export shutdown complete (net: %x).\n", net->ns.inum);
+}
diff --git a/fs/nfsd/export.h b/fs/nfsd/export.h
new file mode 100644
index 000000000..e7daa1f24
--- /dev/null
+++ b/fs/nfsd/export.h
@@ -0,0 +1,117 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 1995-1997 Olaf Kirch <okir@monad.swb.de>
+ */
+#ifndef NFSD_EXPORT_H
+#define NFSD_EXPORT_H
+
+#include <linux/sunrpc/cache.h>
+#include <uapi/linux/nfsd/export.h>
+#include <linux/nfs4.h>
+
+struct knfsd_fh;
+struct svc_fh;
+struct svc_rqst;
+
+/*
+ * FS Locations
+ */
+
+#define MAX_FS_LOCATIONS	128
+
+struct nfsd4_fs_location {
+	char *hosts; /* colon separated list of hosts */
+	char *path;  /* slash separated list of path components */
+};
+
+struct nfsd4_fs_locations {
+	uint32_t locations_count;
+	struct nfsd4_fs_location *locations;
+/* If we're not actually serving this data ourselves (only providing a
+ * list of replicas that do serve it) then we set "migrated": */
+	int migrated;
+};
+
+/*
+ * We keep an array of pseudoflavors with the export, in order from most
+ * to least preferred.  For the foreseeable future, we don't expect more
+ * than the eight pseudoflavors null, unix, krb5, krb5i, krb5p, skpm3,
+ * spkm3i, and spkm3p (and using all 8 at once should be rare).
+ */
+#define MAX_SECINFO_LIST	8
+#define EX_UUID_LEN		16
+
+struct exp_flavor_info {
+	u32	pseudoflavor;
+	u32	flags;
+};
+
+struct svc_export {
+	struct cache_head	h;
+	struct auth_domain *	ex_client;
+	int			ex_flags;
+	struct path		ex_path;
+	kuid_t			ex_anon_uid;
+	kgid_t			ex_anon_gid;
+	int			ex_fsid;
+	unsigned char *		ex_uuid; /* 16 byte fsid */
+	struct nfsd4_fs_locations ex_fslocs;
+	uint32_t		ex_nflavors;
+	struct exp_flavor_info	ex_flavors[MAX_SECINFO_LIST];
+	u32			ex_layout_types;
+	struct nfsd4_deviceid_map *ex_devid_map;
+	struct cache_detail	*cd;
+	struct rcu_head		ex_rcu;
+};
+
+/* an "export key" (expkey) maps a filehandlefragement to an
+ * svc_export for a given client.  There can be several per export,
+ * for the different fsid types.
+ */
+struct svc_expkey {
+	struct cache_head	h;
+
+	struct auth_domain *	ek_client;
+	int			ek_fsidtype;
+	u32			ek_fsid[6];
+
+	struct path		ek_path;
+	struct rcu_head		ek_rcu;
+};
+
+#define EX_ISSYNC(exp)		(!((exp)->ex_flags & NFSEXP_ASYNC))
+#define EX_NOHIDE(exp)		((exp)->ex_flags & NFSEXP_NOHIDE)
+#define EX_WGATHER(exp)		((exp)->ex_flags & NFSEXP_GATHERED_WRITES)
+
+int nfsexp_flags(struct svc_rqst *rqstp, struct svc_export *exp);
+__be32 check_nfsd_access(struct svc_export *exp, struct svc_rqst *rqstp);
+
+/*
+ * Function declarations
+ */
+int			nfsd_export_init(struct net *);
+void			nfsd_export_shutdown(struct net *);
+void			nfsd_export_flush(struct net *);
+struct svc_export *	rqst_exp_get_by_name(struct svc_rqst *,
+					     struct path *);
+struct svc_export *	rqst_exp_parent(struct svc_rqst *,
+					struct path *);
+struct svc_export *	rqst_find_fsidzero_export(struct svc_rqst *);
+int			exp_rootfh(struct net *, struct auth_domain *,
+					char *path, struct knfsd_fh *, int maxsize);
+__be32			exp_pseudoroot(struct svc_rqst *, struct svc_fh *);
+__be32			nfserrno(int errno);
+
+static inline void exp_put(struct svc_export *exp)
+{
+	cache_put(&exp->h, exp->cd);
+}
+
+static inline struct svc_export *exp_get(struct svc_export *exp)
+{
+	cache_get(&exp->h);
+	return exp;
+}
+struct svc_export * rqst_exp_find(struct svc_rqst *, int, u32 *);
+
+#endif /* NFSD_EXPORT_H */
diff --git a/fs/nfsd/fault_inject.c b/fs/nfsd/fault_inject.c
new file mode 100644
index 000000000..76bee0a0d
--- /dev/null
+++ b/fs/nfsd/fault_inject.c
@@ -0,0 +1,142 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2011 Bryan Schumaker <bjschuma@netapp.com>
+ *
+ * Uses debugfs to create fault injection points for client testing
+ */
+
+#include <linux/types.h>
+#include <linux/fs.h>
+#include <linux/debugfs.h>
+#include <linux/module.h>
+#include <linux/nsproxy.h>
+#include <linux/sunrpc/addr.h>
+#include <linux/uaccess.h>
+#include <linux/kernel.h>
+
+#include "state.h"
+#include "netns.h"
+
+struct nfsd_fault_inject_op {
+	char *file;
+	u64 (*get)(void);
+	u64 (*set_val)(u64);
+	u64 (*set_clnt)(struct sockaddr_storage *, size_t);
+};
+
+static struct dentry *debug_dir;
+
+static ssize_t fault_inject_read(struct file *file, char __user *buf,
+				 size_t len, loff_t *ppos)
+{
+	static u64 val;
+	char read_buf[25];
+	size_t size;
+	loff_t pos = *ppos;
+	struct nfsd_fault_inject_op *op = file_inode(file)->i_private;
+
+	if (!pos)
+		val = op->get();
+	size = scnprintf(read_buf, sizeof(read_buf), "%llu\n", val);
+
+	return simple_read_from_buffer(buf, len, ppos, read_buf, size);
+}
+
+static ssize_t fault_inject_write(struct file *file, const char __user *buf,
+				  size_t len, loff_t *ppos)
+{
+	char write_buf[INET6_ADDRSTRLEN];
+	size_t size = min(sizeof(write_buf) - 1, len);
+	struct net *net = current->nsproxy->net_ns;
+	struct sockaddr_storage sa;
+	struct nfsd_fault_inject_op *op = file_inode(file)->i_private;
+	u64 val;
+	char *nl;
+
+	if (copy_from_user(write_buf, buf, size))
+		return -EFAULT;
+	write_buf[size] = '\0';
+
+	/* Deal with any embedded newlines in the string */
+	nl = strchr(write_buf, '\n');
+	if (nl) {
+		size = nl - write_buf;
+		*nl = '\0';
+	}
+
+	size = rpc_pton(net, write_buf, size, (struct sockaddr *)&sa, sizeof(sa));
+	if (size > 0) {
+		val = op->set_clnt(&sa, size);
+		if (val)
+			pr_info("NFSD [%s]: Client %s had %llu state object(s)\n",
+				op->file, write_buf, val);
+	} else {
+		val = simple_strtoll(write_buf, NULL, 0);
+		if (val == 0)
+			pr_info("NFSD Fault Injection: %s (all)", op->file);
+		else
+			pr_info("NFSD Fault Injection: %s (n = %llu)",
+				op->file, val);
+		val = op->set_val(val);
+		pr_info("NFSD: %s: found %llu", op->file, val);
+	}
+	return len; /* on success, claim we got the whole input */
+}
+
+static const struct file_operations fops_nfsd = {
+	.owner   = THIS_MODULE,
+	.read    = fault_inject_read,
+	.write   = fault_inject_write,
+};
+
+void nfsd_fault_inject_cleanup(void)
+{
+	debugfs_remove_recursive(debug_dir);
+}
+
+static struct nfsd_fault_inject_op inject_ops[] = {
+	{
+		.file     = "forget_clients",
+		.get	  = nfsd_inject_print_clients,
+		.set_val  = nfsd_inject_forget_clients,
+		.set_clnt = nfsd_inject_forget_client,
+	},
+	{
+		.file     = "forget_locks",
+		.get	  = nfsd_inject_print_locks,
+		.set_val  = nfsd_inject_forget_locks,
+		.set_clnt = nfsd_inject_forget_client_locks,
+	},
+	{
+		.file     = "forget_openowners",
+		.get	  = nfsd_inject_print_openowners,
+		.set_val  = nfsd_inject_forget_openowners,
+		.set_clnt = nfsd_inject_forget_client_openowners,
+	},
+	{
+		.file     = "forget_delegations",
+		.get	  = nfsd_inject_print_delegations,
+		.set_val  = nfsd_inject_forget_delegations,
+		.set_clnt = nfsd_inject_forget_client_delegations,
+	},
+	{
+		.file     = "recall_delegations",
+		.get	  = nfsd_inject_print_delegations,
+		.set_val  = nfsd_inject_recall_delegations,
+		.set_clnt = nfsd_inject_recall_client_delegations,
+	},
+};
+
+void nfsd_fault_inject_init(void)
+{
+	unsigned int i;
+	struct nfsd_fault_inject_op *op;
+	umode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
+
+	debug_dir = debugfs_create_dir("nfsd", NULL);
+
+	for (i = 0; i < ARRAY_SIZE(inject_ops); i++) {
+		op = &inject_ops[i];
+		debugfs_create_file(op->file, mode, debug_dir, op, &fops_nfsd);
+	}
+}
diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c
new file mode 100644
index 000000000..e30e1ddc1
--- /dev/null
+++ b/fs/nfsd/filecache.c
@@ -0,0 +1,1092 @@
+/*
+ * Open file cache.
+ *
+ * (c) 2015 - Jeff Layton <jeff.layton@primarydata.com>
+ */
+
+#include <linux/hash.h>
+#include <linux/slab.h>
+#include <linux/file.h>
+#include <linux/sched.h>
+#include <linux/list_lru.h>
+#include <linux/fsnotify_backend.h>
+#include <linux/fsnotify.h>
+#include <linux/seq_file.h>
+
+#include "vfs.h"
+#include "nfsd.h"
+#include "nfsfh.h"
+#include "netns.h"
+#include "filecache.h"
+#include "trace.h"
+
+#define NFSDDBG_FACILITY	NFSDDBG_FH
+
+/* FIXME: dynamically size this for the machine somehow? */
+#define NFSD_FILE_HASH_BITS                   12
+#define NFSD_FILE_HASH_SIZE                  (1 << NFSD_FILE_HASH_BITS)
+#define NFSD_LAUNDRETTE_DELAY		     (2 * HZ)
+
+#define NFSD_FILE_SHUTDOWN		     (1)
+#define NFSD_FILE_LRU_THRESHOLD		     (4096UL)
+#define NFSD_FILE_LRU_LIMIT		     (NFSD_FILE_LRU_THRESHOLD << 2)
+
+/* We only care about NFSD_MAY_READ/WRITE for this cache */
+#define NFSD_FILE_MAY_MASK	(NFSD_MAY_READ|NFSD_MAY_WRITE)
+
+struct nfsd_fcache_bucket {
+	struct hlist_head	nfb_head;
+	spinlock_t		nfb_lock;
+	unsigned int		nfb_count;
+	unsigned int		nfb_maxcount;
+};
+
+static DEFINE_PER_CPU(unsigned long, nfsd_file_cache_hits);
+
+struct nfsd_fcache_disposal {
+	struct list_head list;
+	struct work_struct work;
+	struct net *net;
+	spinlock_t lock;
+	struct list_head freeme;
+	struct rcu_head rcu;
+};
+
+static struct workqueue_struct *nfsd_filecache_wq __read_mostly;
+
+static struct kmem_cache		*nfsd_file_slab;
+static struct kmem_cache		*nfsd_file_mark_slab;
+static struct nfsd_fcache_bucket	*nfsd_file_hashtbl;
+static struct list_lru			nfsd_file_lru;
+static long				nfsd_file_lru_flags;
+static struct fsnotify_group		*nfsd_file_fsnotify_group;
+static atomic_long_t			nfsd_filecache_count;
+static struct delayed_work		nfsd_filecache_laundrette;
+static DEFINE_SPINLOCK(laundrette_lock);
+static LIST_HEAD(laundrettes);
+
+static void nfsd_file_gc(void);
+
+static void
+nfsd_file_schedule_laundrette(void)
+{
+	long count = atomic_long_read(&nfsd_filecache_count);
+
+	if (count == 0 || test_bit(NFSD_FILE_SHUTDOWN, &nfsd_file_lru_flags))
+		return;
+
+	queue_delayed_work(system_wq, &nfsd_filecache_laundrette,
+			NFSD_LAUNDRETTE_DELAY);
+}
+
+static void
+nfsd_file_slab_free(struct rcu_head *rcu)
+{
+	struct nfsd_file *nf = container_of(rcu, struct nfsd_file, nf_rcu);
+
+	put_cred(nf->nf_cred);
+	kmem_cache_free(nfsd_file_slab, nf);
+}
+
+static void
+nfsd_file_mark_free(struct fsnotify_mark *mark)
+{
+	struct nfsd_file_mark *nfm = container_of(mark, struct nfsd_file_mark,
+						  nfm_mark);
+
+	kmem_cache_free(nfsd_file_mark_slab, nfm);
+}
+
+static struct nfsd_file_mark *
+nfsd_file_mark_get(struct nfsd_file_mark *nfm)
+{
+	if (!refcount_inc_not_zero(&nfm->nfm_ref))
+		return NULL;
+	return nfm;
+}
+
+static void
+nfsd_file_mark_put(struct nfsd_file_mark *nfm)
+{
+	if (refcount_dec_and_test(&nfm->nfm_ref)) {
+		fsnotify_destroy_mark(&nfm->nfm_mark, nfsd_file_fsnotify_group);
+		fsnotify_put_mark(&nfm->nfm_mark);
+	}
+}
+
+static struct nfsd_file_mark *
+nfsd_file_mark_find_or_create(struct nfsd_file *nf)
+{
+	int			err;
+	struct fsnotify_mark	*mark;
+	struct nfsd_file_mark	*nfm = NULL, *new;
+	struct inode *inode = nf->nf_inode;
+
+	do {
+		mutex_lock(&nfsd_file_fsnotify_group->mark_mutex);
+		mark = fsnotify_find_mark(&inode->i_fsnotify_marks,
+				nfsd_file_fsnotify_group);
+		if (mark) {
+			nfm = nfsd_file_mark_get(container_of(mark,
+						 struct nfsd_file_mark,
+						 nfm_mark));
+			mutex_unlock(&nfsd_file_fsnotify_group->mark_mutex);
+			if (nfm) {
+				fsnotify_put_mark(mark);
+				break;
+			}
+			/* Avoid soft lockup race with nfsd_file_mark_put() */
+			fsnotify_destroy_mark(mark, nfsd_file_fsnotify_group);
+			fsnotify_put_mark(mark);
+		} else
+			mutex_unlock(&nfsd_file_fsnotify_group->mark_mutex);
+
+		/* allocate a new nfm */
+		new = kmem_cache_alloc(nfsd_file_mark_slab, GFP_KERNEL);
+		if (!new)
+			return NULL;
+		fsnotify_init_mark(&new->nfm_mark, nfsd_file_fsnotify_group);
+		new->nfm_mark.mask = FS_ATTRIB|FS_DELETE_SELF;
+		refcount_set(&new->nfm_ref, 1);
+
+		err = fsnotify_add_inode_mark(&new->nfm_mark, inode, 0);
+
+		/*
+		 * If the add was successful, then return the object.
+		 * Otherwise, we need to put the reference we hold on the
+		 * nfm_mark. The fsnotify code will take a reference and put
+		 * it on failure, so we can't just free it directly. It's also
+		 * not safe to call fsnotify_destroy_mark on it as the
+		 * mark->group will be NULL. Thus, we can't let the nfm_ref
+		 * counter drive the destruction at this point.
+		 */
+		if (likely(!err))
+			nfm = new;
+		else
+			fsnotify_put_mark(&new->nfm_mark);
+	} while (unlikely(err == -EEXIST));
+
+	return nfm;
+}
+
+static struct nfsd_file *
+nfsd_file_alloc(struct inode *inode, unsigned int may, unsigned int hashval,
+		struct net *net)
+{
+	struct nfsd_file *nf;
+
+	nf = kmem_cache_alloc(nfsd_file_slab, GFP_KERNEL);
+	if (nf) {
+		INIT_HLIST_NODE(&nf->nf_node);
+		INIT_LIST_HEAD(&nf->nf_lru);
+		nf->nf_file = NULL;
+		nf->nf_cred = get_current_cred();
+		nf->nf_net = net;
+		nf->nf_flags = 0;
+		nf->nf_inode = inode;
+		nf->nf_hashval = hashval;
+		refcount_set(&nf->nf_ref, 1);
+		nf->nf_may = may & NFSD_FILE_MAY_MASK;
+		if (may & NFSD_MAY_NOT_BREAK_LEASE) {
+			if (may & NFSD_MAY_WRITE)
+				__set_bit(NFSD_FILE_BREAK_WRITE, &nf->nf_flags);
+			if (may & NFSD_MAY_READ)
+				__set_bit(NFSD_FILE_BREAK_READ, &nf->nf_flags);
+		}
+		nf->nf_mark = NULL;
+		trace_nfsd_file_alloc(nf);
+	}
+	return nf;
+}
+
+static bool
+nfsd_file_free(struct nfsd_file *nf)
+{
+	bool flush = false;
+
+	trace_nfsd_file_put_final(nf);
+	if (nf->nf_mark)
+		nfsd_file_mark_put(nf->nf_mark);
+	if (nf->nf_file) {
+		get_file(nf->nf_file);
+		filp_close(nf->nf_file, NULL);
+		fput(nf->nf_file);
+		flush = true;
+	}
+	call_rcu(&nf->nf_rcu, nfsd_file_slab_free);
+	return flush;
+}
+
+static bool
+nfsd_file_check_writeback(struct nfsd_file *nf)
+{
+	struct file *file = nf->nf_file;
+	struct address_space *mapping;
+
+	if (!file || !(file->f_mode & FMODE_WRITE))
+		return false;
+	mapping = file->f_mapping;
+	return mapping_tagged(mapping, PAGECACHE_TAG_DIRTY) ||
+		mapping_tagged(mapping, PAGECACHE_TAG_WRITEBACK);
+}
+
+static int
+nfsd_file_check_write_error(struct nfsd_file *nf)
+{
+	struct file *file = nf->nf_file;
+
+	if (!file || !(file->f_mode & FMODE_WRITE))
+		return 0;
+	return filemap_check_wb_err(file->f_mapping, READ_ONCE(file->f_wb_err));
+}
+
+static void
+nfsd_file_do_unhash(struct nfsd_file *nf)
+{
+	lockdep_assert_held(&nfsd_file_hashtbl[nf->nf_hashval].nfb_lock);
+
+	trace_nfsd_file_unhash(nf);
+
+	if (nfsd_file_check_write_error(nf))
+		nfsd_reset_boot_verifier(net_generic(nf->nf_net, nfsd_net_id));
+	--nfsd_file_hashtbl[nf->nf_hashval].nfb_count;
+	hlist_del_rcu(&nf->nf_node);
+	atomic_long_dec(&nfsd_filecache_count);
+}
+
+static bool
+nfsd_file_unhash(struct nfsd_file *nf)
+{
+	if (test_and_clear_bit(NFSD_FILE_HASHED, &nf->nf_flags)) {
+		nfsd_file_do_unhash(nf);
+		if (!list_empty(&nf->nf_lru))
+			list_lru_del(&nfsd_file_lru, &nf->nf_lru);
+		return true;
+	}
+	return false;
+}
+
+/*
+ * Return true if the file was unhashed.
+ */
+static bool
+nfsd_file_unhash_and_release_locked(struct nfsd_file *nf, struct list_head *dispose)
+{
+	lockdep_assert_held(&nfsd_file_hashtbl[nf->nf_hashval].nfb_lock);
+
+	trace_nfsd_file_unhash_and_release_locked(nf);
+	if (!nfsd_file_unhash(nf))
+		return false;
+	/* keep final reference for nfsd_file_lru_dispose */
+	if (refcount_dec_not_one(&nf->nf_ref))
+		return true;
+
+	list_add(&nf->nf_lru, dispose);
+	return true;
+}
+
+static void
+nfsd_file_put_noref(struct nfsd_file *nf)
+{
+	trace_nfsd_file_put(nf);
+
+	if (refcount_dec_and_test(&nf->nf_ref)) {
+		WARN_ON(test_bit(NFSD_FILE_HASHED, &nf->nf_flags));
+		nfsd_file_free(nf);
+	}
+}
+
+void
+nfsd_file_put(struct nfsd_file *nf)
+{
+	bool is_hashed;
+
+	set_bit(NFSD_FILE_REFERENCED, &nf->nf_flags);
+	if (refcount_read(&nf->nf_ref) > 2 || !nf->nf_file) {
+		nfsd_file_put_noref(nf);
+		return;
+	}
+
+	filemap_flush(nf->nf_file->f_mapping);
+	is_hashed = test_bit(NFSD_FILE_HASHED, &nf->nf_flags) != 0;
+	nfsd_file_put_noref(nf);
+	if (is_hashed)
+		nfsd_file_schedule_laundrette();
+	if (atomic_long_read(&nfsd_filecache_count) >= NFSD_FILE_LRU_LIMIT)
+		nfsd_file_gc();
+}
+
+struct nfsd_file *
+nfsd_file_get(struct nfsd_file *nf)
+{
+	if (likely(refcount_inc_not_zero(&nf->nf_ref)))
+		return nf;
+	return NULL;
+}
+
+static void
+nfsd_file_dispose_list(struct list_head *dispose)
+{
+	struct nfsd_file *nf;
+
+	while(!list_empty(dispose)) {
+		nf = list_first_entry(dispose, struct nfsd_file, nf_lru);
+		list_del(&nf->nf_lru);
+		nfsd_file_put_noref(nf);
+	}
+}
+
+static void
+nfsd_file_dispose_list_sync(struct list_head *dispose)
+{
+	bool flush = false;
+	struct nfsd_file *nf;
+
+	while(!list_empty(dispose)) {
+		nf = list_first_entry(dispose, struct nfsd_file, nf_lru);
+		list_del(&nf->nf_lru);
+		if (!refcount_dec_and_test(&nf->nf_ref))
+			continue;
+		if (nfsd_file_free(nf))
+			flush = true;
+	}
+	if (flush)
+		flush_delayed_fput();
+}
+
+static void
+nfsd_file_list_remove_disposal(struct list_head *dst,
+		struct nfsd_fcache_disposal *l)
+{
+	spin_lock(&l->lock);
+	list_splice_init(&l->freeme, dst);
+	spin_unlock(&l->lock);
+}
+
+static void
+nfsd_file_list_add_disposal(struct list_head *files, struct net *net)
+{
+	struct nfsd_fcache_disposal *l;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(l, &laundrettes, list) {
+		if (l->net == net) {
+			spin_lock(&l->lock);
+			list_splice_tail_init(files, &l->freeme);
+			spin_unlock(&l->lock);
+			queue_work(nfsd_filecache_wq, &l->work);
+			break;
+		}
+	}
+	rcu_read_unlock();
+}
+
+static void
+nfsd_file_list_add_pernet(struct list_head *dst, struct list_head *src,
+		struct net *net)
+{
+	struct nfsd_file *nf, *tmp;
+
+	list_for_each_entry_safe(nf, tmp, src, nf_lru) {
+		if (nf->nf_net == net)
+			list_move_tail(&nf->nf_lru, dst);
+	}
+}
+
+static void
+nfsd_file_dispose_list_delayed(struct list_head *dispose)
+{
+	LIST_HEAD(list);
+	struct nfsd_file *nf;
+
+	while(!list_empty(dispose)) {
+		nf = list_first_entry(dispose, struct nfsd_file, nf_lru);
+		nfsd_file_list_add_pernet(&list, dispose, nf->nf_net);
+		nfsd_file_list_add_disposal(&list, nf->nf_net);
+	}
+}
+
+/*
+ * Note this can deadlock with nfsd_file_cache_purge.
+ */
+static enum lru_status
+nfsd_file_lru_cb(struct list_head *item, struct list_lru_one *lru,
+		 spinlock_t *lock, void *arg)
+	__releases(lock)
+	__acquires(lock)
+{
+	struct list_head *head = arg;
+	struct nfsd_file *nf = list_entry(item, struct nfsd_file, nf_lru);
+
+	/*
+	 * Do a lockless refcount check. The hashtable holds one reference, so
+	 * we look to see if anything else has a reference, or if any have
+	 * been put since the shrinker last ran. Those don't get unhashed and
+	 * released.
+	 *
+	 * Note that in the put path, we set the flag and then decrement the
+	 * counter. Here we check the counter and then test and clear the flag.
+	 * That order is deliberate to ensure that we can do this locklessly.
+	 */
+	if (refcount_read(&nf->nf_ref) > 1)
+		goto out_skip;
+
+	/*
+	 * Don't throw out files that are still undergoing I/O or
+	 * that have uncleared errors pending.
+	 */
+	if (nfsd_file_check_writeback(nf))
+		goto out_skip;
+
+	if (test_and_clear_bit(NFSD_FILE_REFERENCED, &nf->nf_flags))
+		goto out_skip;
+
+	if (!test_and_clear_bit(NFSD_FILE_HASHED, &nf->nf_flags))
+		goto out_skip;
+
+	list_lru_isolate_move(lru, &nf->nf_lru, head);
+	return LRU_REMOVED;
+out_skip:
+	return LRU_SKIP;
+}
+
+static unsigned long
+nfsd_file_lru_walk_list(struct shrink_control *sc)
+{
+	LIST_HEAD(head);
+	struct nfsd_file *nf;
+	unsigned long ret;
+
+	if (sc)
+		ret = list_lru_shrink_walk(&nfsd_file_lru, sc,
+				nfsd_file_lru_cb, &head);
+	else
+		ret = list_lru_walk(&nfsd_file_lru,
+				nfsd_file_lru_cb,
+				&head, LONG_MAX);
+	list_for_each_entry(nf, &head, nf_lru) {
+		spin_lock(&nfsd_file_hashtbl[nf->nf_hashval].nfb_lock);
+		nfsd_file_do_unhash(nf);
+		spin_unlock(&nfsd_file_hashtbl[nf->nf_hashval].nfb_lock);
+	}
+	nfsd_file_dispose_list_delayed(&head);
+	return ret;
+}
+
+static void
+nfsd_file_gc(void)
+{
+	nfsd_file_lru_walk_list(NULL);
+}
+
+static void
+nfsd_file_gc_worker(struct work_struct *work)
+{
+	nfsd_file_gc();
+	nfsd_file_schedule_laundrette();
+}
+
+static unsigned long
+nfsd_file_lru_count(struct shrinker *s, struct shrink_control *sc)
+{
+	return list_lru_count(&nfsd_file_lru);
+}
+
+static unsigned long
+nfsd_file_lru_scan(struct shrinker *s, struct shrink_control *sc)
+{
+	return nfsd_file_lru_walk_list(sc);
+}
+
+static struct shrinker	nfsd_file_shrinker = {
+	.scan_objects = nfsd_file_lru_scan,
+	.count_objects = nfsd_file_lru_count,
+	.seeks = 1,
+};
+
+static void
+__nfsd_file_close_inode(struct inode *inode, unsigned int hashval,
+			struct list_head *dispose)
+{
+	struct nfsd_file	*nf;
+	struct hlist_node	*tmp;
+
+	spin_lock(&nfsd_file_hashtbl[hashval].nfb_lock);
+	hlist_for_each_entry_safe(nf, tmp, &nfsd_file_hashtbl[hashval].nfb_head, nf_node) {
+		if (inode == nf->nf_inode)
+			nfsd_file_unhash_and_release_locked(nf, dispose);
+	}
+	spin_unlock(&nfsd_file_hashtbl[hashval].nfb_lock);
+}
+
+/**
+ * nfsd_file_close_inode_sync - attempt to forcibly close a nfsd_file
+ * @inode: inode of the file to attempt to remove
+ *
+ * Walk the whole hash bucket, looking for any files that correspond to "inode".
+ * If any do, then unhash them and put the hashtable reference to them and
+ * destroy any that had their last reference put. Also ensure that any of the
+ * fputs also have their final __fput done as well.
+ */
+void
+nfsd_file_close_inode_sync(struct inode *inode)
+{
+	unsigned int		hashval = (unsigned int)hash_long(inode->i_ino,
+						NFSD_FILE_HASH_BITS);
+	LIST_HEAD(dispose);
+
+	__nfsd_file_close_inode(inode, hashval, &dispose);
+	trace_nfsd_file_close_inode_sync(inode, hashval, !list_empty(&dispose));
+	nfsd_file_dispose_list_sync(&dispose);
+}
+
+/**
+ * nfsd_file_close_inode_sync - attempt to forcibly close a nfsd_file
+ * @inode: inode of the file to attempt to remove
+ *
+ * Walk the whole hash bucket, looking for any files that correspond to "inode".
+ * If any do, then unhash them and put the hashtable reference to them and
+ * destroy any that had their last reference put.
+ */
+static void
+nfsd_file_close_inode(struct inode *inode)
+{
+	unsigned int		hashval = (unsigned int)hash_long(inode->i_ino,
+						NFSD_FILE_HASH_BITS);
+	LIST_HEAD(dispose);
+
+	__nfsd_file_close_inode(inode, hashval, &dispose);
+	trace_nfsd_file_close_inode(inode, hashval, !list_empty(&dispose));
+	nfsd_file_dispose_list_delayed(&dispose);
+}
+
+/**
+ * nfsd_file_delayed_close - close unused nfsd_files
+ * @work: dummy
+ *
+ * Walk the LRU list and close any entries that have not been used since
+ * the last scan.
+ *
+ * Note this can deadlock with nfsd_file_cache_purge.
+ */
+static void
+nfsd_file_delayed_close(struct work_struct *work)
+{
+	LIST_HEAD(head);
+	struct nfsd_fcache_disposal *l = container_of(work,
+			struct nfsd_fcache_disposal, work);
+
+	nfsd_file_list_remove_disposal(&head, l);
+	nfsd_file_dispose_list(&head);
+}
+
+static int
+nfsd_file_lease_notifier_call(struct notifier_block *nb, unsigned long arg,
+			    void *data)
+{
+	struct file_lock *fl = data;
+
+	/* Only close files for F_SETLEASE leases */
+	if (fl->fl_flags & FL_LEASE)
+		nfsd_file_close_inode_sync(file_inode(fl->fl_file));
+	return 0;
+}
+
+static struct notifier_block nfsd_file_lease_notifier = {
+	.notifier_call = nfsd_file_lease_notifier_call,
+};
+
+static int
+nfsd_file_fsnotify_handle_event(struct fsnotify_mark *mark, u32 mask,
+				struct inode *inode, struct inode *dir,
+				const struct qstr *name, u32 cookie)
+{
+	trace_nfsd_file_fsnotify_handle_event(inode, mask);
+
+	/* Should be no marks on non-regular files */
+	if (!S_ISREG(inode->i_mode)) {
+		WARN_ON_ONCE(1);
+		return 0;
+	}
+
+	/* don't close files if this was not the last link */
+	if (mask & FS_ATTRIB) {
+		if (inode->i_nlink)
+			return 0;
+	}
+
+	nfsd_file_close_inode(inode);
+	return 0;
+}
+
+
+static const struct fsnotify_ops nfsd_file_fsnotify_ops = {
+	.handle_inode_event = nfsd_file_fsnotify_handle_event,
+	.free_mark = nfsd_file_mark_free,
+};
+
+int
+nfsd_file_cache_init(void)
+{
+	int		ret = -ENOMEM;
+	unsigned int	i;
+
+	clear_bit(NFSD_FILE_SHUTDOWN, &nfsd_file_lru_flags);
+
+	if (nfsd_file_hashtbl)
+		return 0;
+
+	nfsd_filecache_wq = alloc_workqueue("nfsd_filecache", 0, 0);
+	if (!nfsd_filecache_wq)
+		goto out;
+
+	nfsd_file_hashtbl = kvcalloc(NFSD_FILE_HASH_SIZE,
+				sizeof(*nfsd_file_hashtbl), GFP_KERNEL);
+	if (!nfsd_file_hashtbl) {
+		pr_err("nfsd: unable to allocate nfsd_file_hashtbl\n");
+		goto out_err;
+	}
+
+	nfsd_file_slab = kmem_cache_create("nfsd_file",
+				sizeof(struct nfsd_file), 0, 0, NULL);
+	if (!nfsd_file_slab) {
+		pr_err("nfsd: unable to create nfsd_file_slab\n");
+		goto out_err;
+	}
+
+	nfsd_file_mark_slab = kmem_cache_create("nfsd_file_mark",
+					sizeof(struct nfsd_file_mark), 0, 0, NULL);
+	if (!nfsd_file_mark_slab) {
+		pr_err("nfsd: unable to create nfsd_file_mark_slab\n");
+		goto out_err;
+	}
+
+
+	ret = list_lru_init(&nfsd_file_lru);
+	if (ret) {
+		pr_err("nfsd: failed to init nfsd_file_lru: %d\n", ret);
+		goto out_err;
+	}
+
+	ret = register_shrinker(&nfsd_file_shrinker);
+	if (ret) {
+		pr_err("nfsd: failed to register nfsd_file_shrinker: %d\n", ret);
+		goto out_lru;
+	}
+
+	ret = lease_register_notifier(&nfsd_file_lease_notifier);
+	if (ret) {
+		pr_err("nfsd: unable to register lease notifier: %d\n", ret);
+		goto out_shrinker;
+	}
+
+	nfsd_file_fsnotify_group = fsnotify_alloc_group(&nfsd_file_fsnotify_ops);
+	if (IS_ERR(nfsd_file_fsnotify_group)) {
+		pr_err("nfsd: unable to create fsnotify group: %ld\n",
+			PTR_ERR(nfsd_file_fsnotify_group));
+		nfsd_file_fsnotify_group = NULL;
+		goto out_notifier;
+	}
+
+	for (i = 0; i < NFSD_FILE_HASH_SIZE; i++) {
+		INIT_HLIST_HEAD(&nfsd_file_hashtbl[i].nfb_head);
+		spin_lock_init(&nfsd_file_hashtbl[i].nfb_lock);
+	}
+
+	INIT_DELAYED_WORK(&nfsd_filecache_laundrette, nfsd_file_gc_worker);
+out:
+	return ret;
+out_notifier:
+	lease_unregister_notifier(&nfsd_file_lease_notifier);
+out_shrinker:
+	unregister_shrinker(&nfsd_file_shrinker);
+out_lru:
+	list_lru_destroy(&nfsd_file_lru);
+out_err:
+	kmem_cache_destroy(nfsd_file_slab);
+	nfsd_file_slab = NULL;
+	kmem_cache_destroy(nfsd_file_mark_slab);
+	nfsd_file_mark_slab = NULL;
+	kvfree(nfsd_file_hashtbl);
+	nfsd_file_hashtbl = NULL;
+	destroy_workqueue(nfsd_filecache_wq);
+	nfsd_filecache_wq = NULL;
+	goto out;
+}
+
+/*
+ * Note this can deadlock with nfsd_file_lru_cb.
+ */
+void
+nfsd_file_cache_purge(struct net *net)
+{
+	unsigned int		i;
+	struct nfsd_file	*nf;
+	struct hlist_node	*next;
+	LIST_HEAD(dispose);
+	bool del;
+
+	if (!nfsd_file_hashtbl)
+		return;
+
+	for (i = 0; i < NFSD_FILE_HASH_SIZE; i++) {
+		struct nfsd_fcache_bucket *nfb = &nfsd_file_hashtbl[i];
+
+		spin_lock(&nfb->nfb_lock);
+		hlist_for_each_entry_safe(nf, next, &nfb->nfb_head, nf_node) {
+			if (net && nf->nf_net != net)
+				continue;
+			del = nfsd_file_unhash_and_release_locked(nf, &dispose);
+
+			/*
+			 * Deadlock detected! Something marked this entry as
+			 * unhased, but hasn't removed it from the hash list.
+			 */
+			WARN_ON_ONCE(!del);
+		}
+		spin_unlock(&nfb->nfb_lock);
+		nfsd_file_dispose_list(&dispose);
+	}
+}
+
+static struct nfsd_fcache_disposal *
+nfsd_alloc_fcache_disposal(struct net *net)
+{
+	struct nfsd_fcache_disposal *l;
+
+	l = kmalloc(sizeof(*l), GFP_KERNEL);
+	if (!l)
+		return NULL;
+	INIT_WORK(&l->work, nfsd_file_delayed_close);
+	l->net = net;
+	spin_lock_init(&l->lock);
+	INIT_LIST_HEAD(&l->freeme);
+	return l;
+}
+
+static void
+nfsd_free_fcache_disposal(struct nfsd_fcache_disposal *l)
+{
+	rcu_assign_pointer(l->net, NULL);
+	cancel_work_sync(&l->work);
+	nfsd_file_dispose_list(&l->freeme);
+	kfree_rcu(l, rcu);
+}
+
+static void
+nfsd_add_fcache_disposal(struct nfsd_fcache_disposal *l)
+{
+	spin_lock(&laundrette_lock);
+	list_add_tail_rcu(&l->list, &laundrettes);
+	spin_unlock(&laundrette_lock);
+}
+
+static void
+nfsd_del_fcache_disposal(struct nfsd_fcache_disposal *l)
+{
+	spin_lock(&laundrette_lock);
+	list_del_rcu(&l->list);
+	spin_unlock(&laundrette_lock);
+}
+
+static int
+nfsd_alloc_fcache_disposal_net(struct net *net)
+{
+	struct nfsd_fcache_disposal *l;
+
+	l = nfsd_alloc_fcache_disposal(net);
+	if (!l)
+		return -ENOMEM;
+	nfsd_add_fcache_disposal(l);
+	return 0;
+}
+
+static void
+nfsd_free_fcache_disposal_net(struct net *net)
+{
+	struct nfsd_fcache_disposal *l;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(l, &laundrettes, list) {
+		if (l->net != net)
+			continue;
+		nfsd_del_fcache_disposal(l);
+		rcu_read_unlock();
+		nfsd_free_fcache_disposal(l);
+		return;
+	}
+	rcu_read_unlock();
+}
+
+int
+nfsd_file_cache_start_net(struct net *net)
+{
+	return nfsd_alloc_fcache_disposal_net(net);
+}
+
+void
+nfsd_file_cache_shutdown_net(struct net *net)
+{
+	nfsd_file_cache_purge(net);
+	nfsd_free_fcache_disposal_net(net);
+}
+
+void
+nfsd_file_cache_shutdown(void)
+{
+	set_bit(NFSD_FILE_SHUTDOWN, &nfsd_file_lru_flags);
+
+	lease_unregister_notifier(&nfsd_file_lease_notifier);
+	unregister_shrinker(&nfsd_file_shrinker);
+	/*
+	 * make sure all callers of nfsd_file_lru_cb are done before
+	 * calling nfsd_file_cache_purge
+	 */
+	cancel_delayed_work_sync(&nfsd_filecache_laundrette);
+	nfsd_file_cache_purge(NULL);
+	list_lru_destroy(&nfsd_file_lru);
+	rcu_barrier();
+	fsnotify_put_group(nfsd_file_fsnotify_group);
+	nfsd_file_fsnotify_group = NULL;
+	kmem_cache_destroy(nfsd_file_slab);
+	nfsd_file_slab = NULL;
+	fsnotify_wait_marks_destroyed();
+	kmem_cache_destroy(nfsd_file_mark_slab);
+	nfsd_file_mark_slab = NULL;
+	kvfree(nfsd_file_hashtbl);
+	nfsd_file_hashtbl = NULL;
+	destroy_workqueue(nfsd_filecache_wq);
+	nfsd_filecache_wq = NULL;
+}
+
+static bool
+nfsd_match_cred(const struct cred *c1, const struct cred *c2)
+{
+	int i;
+
+	if (!uid_eq(c1->fsuid, c2->fsuid))
+		return false;
+	if (!gid_eq(c1->fsgid, c2->fsgid))
+		return false;
+	if (c1->group_info == NULL || c2->group_info == NULL)
+		return c1->group_info == c2->group_info;
+	if (c1->group_info->ngroups != c2->group_info->ngroups)
+		return false;
+	for (i = 0; i < c1->group_info->ngroups; i++) {
+		if (!gid_eq(c1->group_info->gid[i], c2->group_info->gid[i]))
+			return false;
+	}
+	return true;
+}
+
+static struct nfsd_file *
+nfsd_file_find_locked(struct inode *inode, unsigned int may_flags,
+			unsigned int hashval, struct net *net)
+{
+	struct nfsd_file *nf;
+	unsigned char need = may_flags & NFSD_FILE_MAY_MASK;
+
+	hlist_for_each_entry_rcu(nf, &nfsd_file_hashtbl[hashval].nfb_head,
+				 nf_node, lockdep_is_held(&nfsd_file_hashtbl[hashval].nfb_lock)) {
+		if (nf->nf_may != need)
+			continue;
+		if (nf->nf_inode != inode)
+			continue;
+		if (nf->nf_net != net)
+			continue;
+		if (!nfsd_match_cred(nf->nf_cred, current_cred()))
+			continue;
+		if (!test_bit(NFSD_FILE_HASHED, &nf->nf_flags))
+			continue;
+		if (nfsd_file_get(nf) != NULL)
+			return nf;
+	}
+	return NULL;
+}
+
+/**
+ * nfsd_file_is_cached - are there any cached open files for this fh?
+ * @inode: inode of the file to check
+ *
+ * Scan the hashtable for open files that match this fh. Returns true if there
+ * are any, and false if not.
+ */
+bool
+nfsd_file_is_cached(struct inode *inode)
+{
+	bool			ret = false;
+	struct nfsd_file	*nf;
+	unsigned int		hashval;
+
+        hashval = (unsigned int)hash_long(inode->i_ino, NFSD_FILE_HASH_BITS);
+
+	rcu_read_lock();
+	hlist_for_each_entry_rcu(nf, &nfsd_file_hashtbl[hashval].nfb_head,
+				 nf_node) {
+		if (inode == nf->nf_inode) {
+			ret = true;
+			break;
+		}
+	}
+	rcu_read_unlock();
+	trace_nfsd_file_is_cached(inode, hashval, (int)ret);
+	return ret;
+}
+
+__be32
+nfsd_file_acquire(struct svc_rqst *rqstp, struct svc_fh *fhp,
+		  unsigned int may_flags, struct nfsd_file **pnf)
+{
+	__be32	status;
+	struct net *net = SVC_NET(rqstp);
+	struct nfsd_file *nf, *new;
+	struct inode *inode;
+	unsigned int hashval;
+	bool retry = true;
+
+	/* FIXME: skip this if fh_dentry is already set? */
+	status = fh_verify(rqstp, fhp, S_IFREG,
+				may_flags|NFSD_MAY_OWNER_OVERRIDE);
+	if (status != nfs_ok)
+		return status;
+
+	inode = d_inode(fhp->fh_dentry);
+	hashval = (unsigned int)hash_long(inode->i_ino, NFSD_FILE_HASH_BITS);
+retry:
+	rcu_read_lock();
+	nf = nfsd_file_find_locked(inode, may_flags, hashval, net);
+	rcu_read_unlock();
+	if (nf)
+		goto wait_for_construction;
+
+	new = nfsd_file_alloc(inode, may_flags, hashval, net);
+	if (!new) {
+		trace_nfsd_file_acquire(rqstp, hashval, inode, may_flags,
+					NULL, nfserr_jukebox);
+		return nfserr_jukebox;
+	}
+
+	spin_lock(&nfsd_file_hashtbl[hashval].nfb_lock);
+	nf = nfsd_file_find_locked(inode, may_flags, hashval, net);
+	if (nf == NULL)
+		goto open_file;
+	spin_unlock(&nfsd_file_hashtbl[hashval].nfb_lock);
+	nfsd_file_slab_free(&new->nf_rcu);
+
+wait_for_construction:
+	wait_on_bit(&nf->nf_flags, NFSD_FILE_PENDING, TASK_UNINTERRUPTIBLE);
+
+	/* Did construction of this file fail? */
+	if (!test_bit(NFSD_FILE_HASHED, &nf->nf_flags)) {
+		if (!retry) {
+			status = nfserr_jukebox;
+			goto out;
+		}
+		retry = false;
+		nfsd_file_put_noref(nf);
+		goto retry;
+	}
+
+	this_cpu_inc(nfsd_file_cache_hits);
+
+	if (!(may_flags & NFSD_MAY_NOT_BREAK_LEASE)) {
+		bool write = (may_flags & NFSD_MAY_WRITE);
+
+		if (test_bit(NFSD_FILE_BREAK_READ, &nf->nf_flags) ||
+		    (test_bit(NFSD_FILE_BREAK_WRITE, &nf->nf_flags) && write)) {
+			status = nfserrno(nfsd_open_break_lease(
+					file_inode(nf->nf_file), may_flags));
+			if (status == nfs_ok) {
+				clear_bit(NFSD_FILE_BREAK_READ, &nf->nf_flags);
+				if (write)
+					clear_bit(NFSD_FILE_BREAK_WRITE,
+						  &nf->nf_flags);
+			}
+		}
+	}
+out:
+	if (status == nfs_ok) {
+		*pnf = nf;
+	} else {
+		nfsd_file_put(nf);
+		nf = NULL;
+	}
+
+	trace_nfsd_file_acquire(rqstp, hashval, inode, may_flags, nf, status);
+	return status;
+open_file:
+	nf = new;
+	/* Take reference for the hashtable */
+	refcount_inc(&nf->nf_ref);
+	__set_bit(NFSD_FILE_HASHED, &nf->nf_flags);
+	__set_bit(NFSD_FILE_PENDING, &nf->nf_flags);
+	list_lru_add(&nfsd_file_lru, &nf->nf_lru);
+	hlist_add_head_rcu(&nf->nf_node, &nfsd_file_hashtbl[hashval].nfb_head);
+	++nfsd_file_hashtbl[hashval].nfb_count;
+	nfsd_file_hashtbl[hashval].nfb_maxcount = max(nfsd_file_hashtbl[hashval].nfb_maxcount,
+			nfsd_file_hashtbl[hashval].nfb_count);
+	spin_unlock(&nfsd_file_hashtbl[hashval].nfb_lock);
+	if (atomic_long_inc_return(&nfsd_filecache_count) >= NFSD_FILE_LRU_THRESHOLD)
+		nfsd_file_gc();
+
+	nf->nf_mark = nfsd_file_mark_find_or_create(nf);
+	if (nf->nf_mark)
+		status = nfsd_open_verified(rqstp, fhp, S_IFREG,
+				may_flags, &nf->nf_file);
+	else
+		status = nfserr_jukebox;
+	/*
+	 * If construction failed, or we raced with a call to unlink()
+	 * then unhash.
+	 */
+	if (status != nfs_ok || inode->i_nlink == 0) {
+		bool do_free;
+		spin_lock(&nfsd_file_hashtbl[hashval].nfb_lock);
+		do_free = nfsd_file_unhash(nf);
+		spin_unlock(&nfsd_file_hashtbl[hashval].nfb_lock);
+		if (do_free)
+			nfsd_file_put_noref(nf);
+	}
+	clear_bit_unlock(NFSD_FILE_PENDING, &nf->nf_flags);
+	smp_mb__after_atomic();
+	wake_up_bit(&nf->nf_flags, NFSD_FILE_PENDING);
+	goto out;
+}
+
+/*
+ * Note that fields may be added, removed or reordered in the future. Programs
+ * scraping this file for info should test the labels to ensure they're
+ * getting the correct field.
+ */
+static int nfsd_file_cache_stats_show(struct seq_file *m, void *v)
+{
+	unsigned int i, count = 0, longest = 0;
+	unsigned long hits = 0;
+
+	/*
+	 * No need for spinlocks here since we're not terribly interested in
+	 * accuracy. We do take the nfsd_mutex simply to ensure that we
+	 * don't end up racing with server shutdown
+	 */
+	mutex_lock(&nfsd_mutex);
+	if (nfsd_file_hashtbl) {
+		for (i = 0; i < NFSD_FILE_HASH_SIZE; i++) {
+			count += nfsd_file_hashtbl[i].nfb_count;
+			longest = max(longest, nfsd_file_hashtbl[i].nfb_count);
+		}
+	}
+	mutex_unlock(&nfsd_mutex);
+
+	for_each_possible_cpu(i)
+		hits += per_cpu(nfsd_file_cache_hits, i);
+
+	seq_printf(m, "total entries: %u\n", count);
+	seq_printf(m, "longest chain: %u\n", longest);
+	seq_printf(m, "cache hits:    %lu\n", hits);
+	return 0;
+}
+
+int nfsd_file_cache_stats_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, nfsd_file_cache_stats_show, NULL);
+}
diff --git a/fs/nfsd/filecache.h b/fs/nfsd/filecache.h
new file mode 100644
index 000000000..435ceab27
--- /dev/null
+++ b/fs/nfsd/filecache.h
@@ -0,0 +1,63 @@
+#ifndef _FS_NFSD_FILECACHE_H
+#define _FS_NFSD_FILECACHE_H
+
+#include <linux/fsnotify_backend.h>
+
+/*
+ * This is the fsnotify_mark container that nfsd attaches to the files that it
+ * is holding open. Note that we have a separate refcount here aside from the
+ * one in the fsnotify_mark. We only want a single fsnotify_mark attached to
+ * the inode, and for each nfsd_file to hold a reference to it.
+ *
+ * The fsnotify_mark is itself refcounted, but that's not sufficient to tell us
+ * how to put that reference. If there are still outstanding nfsd_files that
+ * reference the mark, then we would want to call fsnotify_put_mark on it.
+ * If there were not, then we'd need to call fsnotify_destroy_mark. Since we
+ * can't really tell the difference, we use the nfm_mark to keep track of how
+ * many nfsd_files hold references to the mark. When that counter goes to zero
+ * then we know to call fsnotify_destroy_mark on it.
+ */
+struct nfsd_file_mark {
+	struct fsnotify_mark	nfm_mark;
+	refcount_t		nfm_ref;
+};
+
+/*
+ * A representation of a file that has been opened by knfsd. These are hashed
+ * in the hashtable by inode pointer value. Note that this object doesn't
+ * hold a reference to the inode by itself, so the nf_inode pointer should
+ * never be dereferenced, only used for comparison.
+ */
+struct nfsd_file {
+	struct hlist_node	nf_node;
+	struct list_head	nf_lru;
+	struct rcu_head		nf_rcu;
+	struct file		*nf_file;
+	const struct cred	*nf_cred;
+	struct net		*nf_net;
+#define NFSD_FILE_HASHED	(0)
+#define NFSD_FILE_PENDING	(1)
+#define NFSD_FILE_BREAK_READ	(2)
+#define NFSD_FILE_BREAK_WRITE	(3)
+#define NFSD_FILE_REFERENCED	(4)
+	unsigned long		nf_flags;
+	struct inode		*nf_inode;
+	unsigned int		nf_hashval;
+	refcount_t		nf_ref;
+	unsigned char		nf_may;
+	struct nfsd_file_mark	*nf_mark;
+};
+
+int nfsd_file_cache_init(void);
+void nfsd_file_cache_purge(struct net *);
+void nfsd_file_cache_shutdown(void);
+int nfsd_file_cache_start_net(struct net *net);
+void nfsd_file_cache_shutdown_net(struct net *net);
+void nfsd_file_put(struct nfsd_file *nf);
+struct nfsd_file *nfsd_file_get(struct nfsd_file *nf);
+void nfsd_file_close_inode_sync(struct inode *inode);
+bool nfsd_file_is_cached(struct inode *inode);
+__be32 nfsd_file_acquire(struct svc_rqst *rqstp, struct svc_fh *fhp,
+		  unsigned int may_flags, struct nfsd_file **nfp);
+int	nfsd_file_cache_stats_open(struct inode *, struct file *);
+#endif /* _FS_NFSD_FILECACHE_H */
diff --git a/fs/nfsd/flexfilelayout.c b/fs/nfsd/flexfilelayout.c
new file mode 100644
index 000000000..db7ef07ae
--- /dev/null
+++ b/fs/nfsd/flexfilelayout.c
@@ -0,0 +1,135 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2016 Tom Haynes <loghyr@primarydata.com>
+ *
+ * The following implements a super-simple flex-file server
+ * where the NFSv4.1 mds is also the ds. And the storage is
+ * the same. I.e., writing to the mds via a NFSv4.1 WRITE
+ * goes to the same location as the NFSv3 WRITE.
+ */
+#include <linux/slab.h>
+
+#include <linux/nfsd/debug.h>
+
+#include <linux/sunrpc/addr.h>
+
+#include "flexfilelayoutxdr.h"
+#include "pnfs.h"
+
+#define NFSDDBG_FACILITY	NFSDDBG_PNFS
+
+static __be32
+nfsd4_ff_proc_layoutget(struct inode *inode, const struct svc_fh *fhp,
+		struct nfsd4_layoutget *args)
+{
+	struct nfsd4_layout_seg *seg = &args->lg_seg;
+	u32 device_generation = 0;
+	int error;
+	uid_t u;
+
+	struct pnfs_ff_layout *fl;
+
+	/*
+	 * The super simple flex file server has 1 mirror, 1 data server,
+	 * and 1 file handle. So instead of 4 allocs, do 1 for now.
+	 * Zero it out for the stateid - don't want junk in there!
+	 */
+	error = -ENOMEM;
+	fl = kzalloc(sizeof(*fl), GFP_KERNEL);
+	if (!fl)
+		goto out_error;
+	args->lg_content = fl;
+
+	/*
+	 * Avoid layout commit, try to force the I/O to the DS,
+	 * and for fun, cause all IOMODE_RW layout segments to
+	 * effectively be WRITE only.
+	 */
+	fl->flags = FF_FLAGS_NO_LAYOUTCOMMIT | FF_FLAGS_NO_IO_THRU_MDS |
+		    FF_FLAGS_NO_READ_IO;
+
+	/* Do not allow a IOMODE_READ segment to have write pemissions */
+	if (seg->iomode == IOMODE_READ) {
+		u = from_kuid(&init_user_ns, inode->i_uid) + 1;
+		fl->uid = make_kuid(&init_user_ns, u);
+	} else
+		fl->uid = inode->i_uid;
+	fl->gid = inode->i_gid;
+
+	error = nfsd4_set_deviceid(&fl->deviceid, fhp, device_generation);
+	if (error)
+		goto out_error;
+
+	fl->fh.size = fhp->fh_handle.fh_size;
+	memcpy(fl->fh.data, &fhp->fh_handle.fh_base, fl->fh.size);
+
+	/* Give whole file layout segments */
+	seg->offset = 0;
+	seg->length = NFS4_MAX_UINT64;
+
+	dprintk("GET: 0x%llx:0x%llx %d\n", seg->offset, seg->length,
+		seg->iomode);
+	return 0;
+
+out_error:
+	seg->length = 0;
+	return nfserrno(error);
+}
+
+static __be32
+nfsd4_ff_proc_getdeviceinfo(struct super_block *sb, struct svc_rqst *rqstp,
+		struct nfs4_client *clp, struct nfsd4_getdeviceinfo *gdp)
+{
+	struct pnfs_ff_device_addr *da;
+
+	u16 port;
+	char addr[INET6_ADDRSTRLEN];
+
+	da = kzalloc(sizeof(struct pnfs_ff_device_addr), GFP_KERNEL);
+	if (!da)
+		return nfserrno(-ENOMEM);
+
+	gdp->gd_device = da;
+
+	da->version = 3;
+	da->minor_version = 0;
+
+	da->rsize = svc_max_payload(rqstp);
+	da->wsize = da->rsize;
+
+	rpc_ntop((struct sockaddr *)&rqstp->rq_daddr,
+		 addr, INET6_ADDRSTRLEN);
+	if (rqstp->rq_daddr.ss_family == AF_INET) {
+		struct sockaddr_in *sin;
+
+		sin = (struct sockaddr_in *)&rqstp->rq_daddr;
+		port = ntohs(sin->sin_port);
+		snprintf(da->netaddr.netid, FF_NETID_LEN + 1, "tcp");
+		da->netaddr.netid_len = 3;
+	} else {
+		struct sockaddr_in6 *sin6;
+
+		sin6 = (struct sockaddr_in6 *)&rqstp->rq_daddr;
+		port = ntohs(sin6->sin6_port);
+		snprintf(da->netaddr.netid, FF_NETID_LEN + 1, "tcp6");
+		da->netaddr.netid_len = 4;
+	}
+
+	da->netaddr.addr_len =
+		snprintf(da->netaddr.addr, FF_ADDR_LEN + 1,
+			 "%s.%hhu.%hhu", addr, port >> 8, port & 0xff);
+
+	da->tightly_coupled = false;
+
+	return 0;
+}
+
+const struct nfsd4_layout_ops ff_layout_ops = {
+	.notify_types		=
+			NOTIFY_DEVICEID4_DELETE | NOTIFY_DEVICEID4_CHANGE,
+	.disable_recalls	= true,
+	.proc_getdeviceinfo	= nfsd4_ff_proc_getdeviceinfo,
+	.encode_getdeviceinfo	= nfsd4_ff_encode_getdeviceinfo,
+	.proc_layoutget		= nfsd4_ff_proc_layoutget,
+	.encode_layoutget	= nfsd4_ff_encode_layoutget,
+};
diff --git a/fs/nfsd/flexfilelayoutxdr.c b/fs/nfsd/flexfilelayoutxdr.c
new file mode 100644
index 000000000..bb205328e
--- /dev/null
+++ b/fs/nfsd/flexfilelayoutxdr.c
@@ -0,0 +1,125 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2016 Tom Haynes <loghyr@primarydata.com>
+ */
+#include <linux/sunrpc/svc.h>
+#include <linux/nfs4.h>
+
+#include "nfsd.h"
+#include "flexfilelayoutxdr.h"
+
+#define NFSDDBG_FACILITY	NFSDDBG_PNFS
+
+struct ff_idmap {
+	char buf[11];
+	int len;
+};
+
+__be32
+nfsd4_ff_encode_layoutget(struct xdr_stream *xdr,
+		struct nfsd4_layoutget *lgp)
+{
+	struct pnfs_ff_layout *fl = lgp->lg_content;
+	int len, mirror_len, ds_len, fh_len;
+	__be32 *p;
+
+	/*
+	 * Unlike nfsd4_encode_user, we know these will
+	 * always be stringified.
+	 */
+	struct ff_idmap uid;
+	struct ff_idmap gid;
+
+	fh_len = 4 + fl->fh.size;
+
+	uid.len = sprintf(uid.buf, "%u", from_kuid(&init_user_ns, fl->uid));
+	gid.len = sprintf(gid.buf, "%u", from_kgid(&init_user_ns, fl->gid));
+
+	/* 8 + len for recording the length, name, and padding */
+	ds_len = 20 + sizeof(stateid_opaque_t) + 4 + fh_len +
+		 8 + uid.len + 8 + gid.len;
+
+	mirror_len = 4 + ds_len;
+
+	/* The layout segment */
+	len = 20 + mirror_len;
+
+	p = xdr_reserve_space(xdr, sizeof(__be32) + len);
+	if (!p)
+		return nfserr_toosmall;
+
+	*p++ = cpu_to_be32(len);
+	p = xdr_encode_hyper(p, 0);		/* stripe unit of 1 */
+
+	*p++ = cpu_to_be32(1);			/* single mirror */
+	*p++ = cpu_to_be32(1);			/* single data server */
+
+	p = xdr_encode_opaque_fixed(p, &fl->deviceid,
+			sizeof(struct nfsd4_deviceid));
+
+	*p++ = cpu_to_be32(1);			/* efficiency */
+
+	*p++ = cpu_to_be32(fl->stateid.si_generation);
+	p = xdr_encode_opaque_fixed(p, &fl->stateid.si_opaque,
+				    sizeof(stateid_opaque_t));
+
+	*p++ = cpu_to_be32(1);			/* single file handle */
+	p = xdr_encode_opaque(p, fl->fh.data, fl->fh.size);
+
+	p = xdr_encode_opaque(p, uid.buf, uid.len);
+	p = xdr_encode_opaque(p, gid.buf, gid.len);
+
+	*p++ = cpu_to_be32(fl->flags);
+	*p++ = cpu_to_be32(0);			/* No stats collect hint */
+
+	return 0;
+}
+
+__be32
+nfsd4_ff_encode_getdeviceinfo(struct xdr_stream *xdr,
+		struct nfsd4_getdeviceinfo *gdp)
+{
+	struct pnfs_ff_device_addr *da = gdp->gd_device;
+	int len;
+	int ver_len;
+	int addr_len;
+	__be32 *p;
+
+	/*
+	 * See paragraph 5 of RFC 8881 S18.40.3.
+	 */
+	if (!gdp->gd_maxcount) {
+		if (xdr_stream_encode_u32(xdr, 0) != XDR_UNIT)
+			return nfserr_resource;
+		return nfs_ok;
+	}
+
+	/* len + padding for two strings */
+	addr_len = 16 + da->netaddr.netid_len + da->netaddr.addr_len;
+	ver_len = 20;
+
+	len = 4 + ver_len + 4 + addr_len;
+
+	p = xdr_reserve_space(xdr, len + sizeof(__be32));
+	if (!p)
+		return nfserr_resource;
+
+	/*
+	 * Fill in the overall length and number of volumes at the beginning
+	 * of the layout.
+	 */
+	*p++ = cpu_to_be32(len);
+	*p++ = cpu_to_be32(1);			/* 1 netaddr */
+	p = xdr_encode_opaque(p, da->netaddr.netid, da->netaddr.netid_len);
+	p = xdr_encode_opaque(p, da->netaddr.addr, da->netaddr.addr_len);
+
+	*p++ = cpu_to_be32(1);			/* 1 versions */
+
+	*p++ = cpu_to_be32(da->version);
+	*p++ = cpu_to_be32(da->minor_version);
+	*p++ = cpu_to_be32(da->rsize);
+	*p++ = cpu_to_be32(da->wsize);
+	*p++ = cpu_to_be32(da->tightly_coupled);
+
+	return 0;
+}
diff --git a/fs/nfsd/flexfilelayoutxdr.h b/fs/nfsd/flexfilelayoutxdr.h
new file mode 100644
index 000000000..8e195aeca
--- /dev/null
+++ b/fs/nfsd/flexfilelayoutxdr.h
@@ -0,0 +1,50 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2016 Tom Haynes <loghyr@primarydata.com>
+ */
+#ifndef _NFSD_FLEXFILELAYOUTXDR_H
+#define _NFSD_FLEXFILELAYOUTXDR_H 1
+
+#include <linux/inet.h>
+#include "xdr4.h"
+
+#define FF_FLAGS_NO_LAYOUTCOMMIT 1
+#define FF_FLAGS_NO_IO_THRU_MDS  2
+#define FF_FLAGS_NO_READ_IO      4
+
+struct xdr_stream;
+
+#define FF_NETID_LEN		(4)
+#define FF_ADDR_LEN		(INET6_ADDRSTRLEN + 8)
+struct pnfs_ff_netaddr {
+	char				netid[FF_NETID_LEN + 1];
+	char				addr[FF_ADDR_LEN + 1];
+	u32				netid_len;
+	u32				addr_len;
+};
+
+struct pnfs_ff_device_addr {
+	struct pnfs_ff_netaddr		netaddr;
+	u32				version;
+	u32				minor_version;
+	u32				rsize;
+	u32				wsize;
+	bool				tightly_coupled;
+};
+
+struct pnfs_ff_layout {
+	u32				flags;
+	u32				stats_collect_hint;
+	kuid_t				uid;
+	kgid_t				gid;
+	struct nfsd4_deviceid		deviceid;
+	stateid_t			stateid;
+	struct nfs_fh			fh;
+};
+
+__be32 nfsd4_ff_encode_getdeviceinfo(struct xdr_stream *xdr,
+		struct nfsd4_getdeviceinfo *gdp);
+__be32 nfsd4_ff_encode_layoutget(struct xdr_stream *xdr,
+		struct nfsd4_layoutget *lgp);
+
+#endif /* _NFSD_FLEXFILELAYOUTXDR_H */
diff --git a/fs/nfsd/idmap.h b/fs/nfsd/idmap.h
new file mode 100644
index 000000000..23cc85d1e
--- /dev/null
+++ b/fs/nfsd/idmap.h
@@ -0,0 +1,60 @@
+/*
+ *  Mapping of UID to name and vice versa.
+ *
+ *  Copyright (c) 2002, 2003 The Regents of the University of
+ *  Michigan.  All rights reserved.
+> *
+ *  Marius Aamodt Eriksen <marius@umich.edu>
+ *
+ *  Redistribution and use in source and binary forms, with or without
+ *  modification, are permitted provided that the following conditions
+ *  are met:
+ *
+ *  1. Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *  2. Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *  3. Neither the name of the University nor the names of its
+ *     contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+ *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef LINUX_NFSD_IDMAP_H
+#define LINUX_NFSD_IDMAP_H
+
+#include <linux/in.h>
+#include <linux/sunrpc/svc.h>
+#include <linux/nfs_idmap.h>
+
+#ifdef CONFIG_NFSD_V4
+int nfsd_idmap_init(struct net *);
+void nfsd_idmap_shutdown(struct net *);
+#else
+static inline int nfsd_idmap_init(struct net *net)
+{
+	return 0;
+}
+static inline void nfsd_idmap_shutdown(struct net *net)
+{
+}
+#endif
+
+__be32 nfsd_map_name_to_uid(struct svc_rqst *, const char *, size_t, kuid_t *);
+__be32 nfsd_map_name_to_gid(struct svc_rqst *, const char *, size_t, kgid_t *);
+__be32 nfsd4_encode_user(struct xdr_stream *, struct svc_rqst *, kuid_t);
+__be32 nfsd4_encode_group(struct xdr_stream *, struct svc_rqst *, kgid_t);
+
+#endif /* LINUX_NFSD_IDMAP_H */
diff --git a/fs/nfsd/lockd.c b/fs/nfsd/lockd.c
new file mode 100644
index 000000000..3f5b3d7b6
--- /dev/null
+++ b/fs/nfsd/lockd.c
@@ -0,0 +1,78 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * This file contains all the stubs needed when communicating with lockd.
+ * This level of indirection is necessary so we can run nfsd+lockd without
+ * requiring the nfs client to be compiled in/loaded, and vice versa.
+ *
+ * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
+ */
+
+#include <linux/file.h>
+#include <linux/lockd/bind.h>
+#include "nfsd.h"
+#include "vfs.h"
+
+#define NFSDDBG_FACILITY		NFSDDBG_LOCKD
+
+#ifdef CONFIG_LOCKD_V4
+#define nlm_stale_fh	nlm4_stale_fh
+#define nlm_failed	nlm4_failed
+#else
+#define nlm_stale_fh	nlm_lck_denied_nolocks
+#define nlm_failed	nlm_lck_denied_nolocks
+#endif
+/*
+ * Note: we hold the dentry use count while the file is open.
+ */
+static __be32
+nlm_fopen(struct svc_rqst *rqstp, struct nfs_fh *f, struct file **filp)
+{
+	__be32		nfserr;
+	struct svc_fh	fh;
+
+	/* must initialize before using! but maxsize doesn't matter */
+	fh_init(&fh,0);
+	fh.fh_handle.fh_size = f->size;
+	memcpy((char*)&fh.fh_handle.fh_base, f->data, f->size);
+	fh.fh_export = NULL;
+
+	nfserr = nfsd_open(rqstp, &fh, S_IFREG, NFSD_MAY_LOCK, filp);
+	fh_put(&fh);
+ 	/* We return nlm error codes as nlm doesn't know
+	 * about nfsd, but nfsd does know about nlm..
+	 */
+	switch (nfserr) {
+	case nfs_ok:
+		return 0;
+	case nfserr_dropit:
+		return nlm_drop_reply;
+	case nfserr_stale:
+		return nlm_stale_fh;
+	default:
+		return nlm_failed;
+	}
+}
+
+static void
+nlm_fclose(struct file *filp)
+{
+	fput(filp);
+}
+
+static const struct nlmsvc_binding nfsd_nlm_ops = {
+	.fopen		= nlm_fopen,		/* open file for locking */
+	.fclose		= nlm_fclose,		/* close file */
+};
+
+void
+nfsd_lockd_init(void)
+{
+	dprintk("nfsd: initializing lockd\n");
+	nlmsvc_ops = &nfsd_nlm_ops;
+}
+
+void
+nfsd_lockd_shutdown(void)
+{
+	nlmsvc_ops = NULL;
+}
diff --git a/fs/nfsd/netns.h b/fs/nfsd/netns.h
new file mode 100644
index 000000000..02d3d2f0e
--- /dev/null
+++ b/fs/nfsd/netns.h
@@ -0,0 +1,187 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * per net namespace data structures for nfsd
+ *
+ * Copyright (C) 2012, Jeff Layton <jlayton@redhat.com>
+ */
+
+#ifndef __NFSD_NETNS_H__
+#define __NFSD_NETNS_H__
+
+#include <net/net_namespace.h>
+#include <net/netns/generic.h>
+
+/* Hash tables for nfs4_clientid state */
+#define CLIENT_HASH_BITS                 4
+#define CLIENT_HASH_SIZE                (1 << CLIENT_HASH_BITS)
+#define CLIENT_HASH_MASK                (CLIENT_HASH_SIZE - 1)
+
+#define SESSION_HASH_SIZE	512
+
+struct cld_net;
+struct nfsd4_client_tracking_ops;
+
+/*
+ * Represents a nfsd "container". With respect to nfsv4 state tracking, the
+ * fields of interest are the *_id_hashtbls and the *_name_tree. These track
+ * the nfs4_client objects by either short or long form clientid.
+ *
+ * Each nfsd_net runs a nfs4_laundromat workqueue job when necessary to clean
+ * up expired clients and delegations within the container.
+ */
+struct nfsd_net {
+	struct cld_net *cld_net;
+
+	struct cache_detail *svc_expkey_cache;
+	struct cache_detail *svc_export_cache;
+
+	struct cache_detail *idtoname_cache;
+	struct cache_detail *nametoid_cache;
+
+	struct lock_manager nfsd4_manager;
+	bool grace_ended;
+	time64_t boot_time;
+
+	struct dentry *nfsd_client_dir;
+
+	/*
+	 * reclaim_str_hashtbl[] holds known client info from previous reset/reboot
+	 * used in reboot/reset lease grace period processing
+	 *
+	 * conf_id_hashtbl[], and conf_name_tree hold confirmed
+	 * setclientid_confirmed info.
+	 *
+	 * unconf_str_hastbl[] and unconf_name_tree hold unconfirmed
+	 * setclientid info.
+	 */
+	struct list_head *reclaim_str_hashtbl;
+	int reclaim_str_hashtbl_size;
+	struct list_head *conf_id_hashtbl;
+	struct rb_root conf_name_tree;
+	struct list_head *unconf_id_hashtbl;
+	struct rb_root unconf_name_tree;
+	struct list_head *sessionid_hashtbl;
+	/*
+	 * client_lru holds client queue ordered by nfs4_client.cl_time
+	 * for lease renewal.
+	 *
+	 * close_lru holds (open) stateowner queue ordered by nfs4_stateowner.so_time
+	 * for last close replay.
+	 *
+	 * All of the above fields are protected by the client_mutex.
+	 */
+	struct list_head client_lru;
+	struct list_head close_lru;
+	struct list_head del_recall_lru;
+
+	/* protected by blocked_locks_lock */
+	struct list_head blocked_locks_lru;
+
+	struct delayed_work laundromat_work;
+
+	/* client_lock protects the client lru list and session hash table */
+	spinlock_t client_lock;
+
+	/* protects blocked_locks_lru */
+	spinlock_t blocked_locks_lock;
+
+	struct file *rec_file;
+	bool in_grace;
+	const struct nfsd4_client_tracking_ops *client_tracking_ops;
+
+	time64_t nfsd4_lease;
+	time64_t nfsd4_grace;
+	bool somebody_reclaimed;
+
+	bool track_reclaim_completes;
+	atomic_t nr_reclaim_complete;
+
+	bool nfsd_net_up;
+	bool lockd_up;
+
+	/* Time of server startup */
+	struct timespec64 nfssvc_boot;
+	seqlock_t boot_lock;
+
+	/*
+	 * Max number of connections this nfsd container will allow. Defaults
+	 * to '0' which is means that it bases this on the number of threads.
+	 */
+	unsigned int max_connections;
+
+	u32 clientid_base;
+	u32 clientid_counter;
+	u32 clverifier_counter;
+
+	struct svc_serv *nfsd_serv;
+
+	wait_queue_head_t ntf_wq;
+	atomic_t ntf_refcnt;
+
+	/* Allow umount to wait for nfsd state cleanup */
+	struct completion nfsd_shutdown_complete;
+
+	/*
+	 * clientid and stateid data for construction of net unique COPY
+	 * stateids.
+	 */
+	u32		s2s_cp_cl_id;
+	struct idr	s2s_cp_stateids;
+	spinlock_t	s2s_cp_lock;
+
+	/*
+	 * Version information
+	 */
+	bool *nfsd_versions;
+	bool *nfsd4_minorversions;
+
+	/*
+	 * Duplicate reply cache
+	 */
+	struct nfsd_drc_bucket   *drc_hashtbl;
+
+	/* max number of entries allowed in the cache */
+	unsigned int             max_drc_entries;
+
+	/* number of significant bits in the hash value */
+	unsigned int             maskbits;
+	unsigned int             drc_hashsize;
+
+	/*
+	 * Stats and other tracking of on the duplicate reply cache.
+	 * These fields and the "rc" fields in nfsdstats are modified
+	 * with only the per-bucket cache lock, which isn't really safe
+	 * and should be fixed if we want the statistics to be
+	 * completely accurate.
+	 */
+
+	/* total number of entries */
+	atomic_t                 num_drc_entries;
+
+	/* cache misses due only to checksum comparison failures */
+	unsigned int             payload_misses;
+
+	/* amount of memory (in bytes) currently consumed by the DRC */
+	unsigned int             drc_mem_usage;
+
+	/* longest hash chain seen */
+	unsigned int             longest_chain;
+
+	/* size of cache when we saw the longest hash chain */
+	unsigned int             longest_chain_cachesize;
+
+	struct shrinker		nfsd_reply_cache_shrinker;
+	/* utsname taken from the process that starts the server */
+	char			nfsd_name[UNX_MAXNODENAME+1];
+};
+
+/* Simple check to find out if a given net was properly initialized */
+#define nfsd_netns_ready(nn) ((nn)->sessionid_hashtbl)
+
+extern void nfsd_netns_free_versions(struct nfsd_net *nn);
+
+extern unsigned int nfsd_net_id;
+
+void nfsd_copy_boot_verifier(__be32 verf[2], struct nfsd_net *nn);
+void nfsd_reset_boot_verifier(struct nfsd_net *nn);
+#endif /* __NFSD_NETNS_H__ */
diff --git a/fs/nfsd/nfs2acl.c b/fs/nfsd/nfs2acl.c
new file mode 100644
index 000000000..6a900f770
--- /dev/null
+++ b/fs/nfsd/nfs2acl.c
@@ -0,0 +1,438 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Process version 2 NFSACL requests.
+ *
+ * Copyright (C) 2002-2003 Andreas Gruenbacher <agruen@suse.de>
+ */
+
+#include "nfsd.h"
+/* FIXME: nfsacl.h is a broken header */
+#include <linux/nfsacl.h>
+#include <linux/gfp.h>
+#include "cache.h"
+#include "xdr3.h"
+#include "vfs.h"
+
+#define NFSDDBG_FACILITY		NFSDDBG_PROC
+
+/*
+ * NULL call.
+ */
+static __be32
+nfsacld_proc_null(struct svc_rqst *rqstp)
+{
+	return rpc_success;
+}
+
+/*
+ * Get the Access and/or Default ACL of a file.
+ */
+static __be32 nfsacld_proc_getacl(struct svc_rqst *rqstp)
+{
+	struct nfsd3_getaclargs *argp = rqstp->rq_argp;
+	struct nfsd3_getaclres *resp = rqstp->rq_resp;
+	struct posix_acl *acl;
+	struct inode *inode;
+	svc_fh *fh;
+
+	dprintk("nfsd: GETACL(2acl)   %s\n", SVCFH_fmt(&argp->fh));
+
+	fh = fh_copy(&resp->fh, &argp->fh);
+	resp->status = fh_verify(rqstp, &resp->fh, 0, NFSD_MAY_NOP);
+	if (resp->status != nfs_ok)
+		goto out;
+
+	inode = d_inode(fh->fh_dentry);
+
+	if (argp->mask & ~NFS_ACL_MASK) {
+		resp->status = nfserr_inval;
+		goto out;
+	}
+	resp->mask = argp->mask;
+
+	resp->status = fh_getattr(fh, &resp->stat);
+	if (resp->status != nfs_ok)
+		goto out;
+
+	if (resp->mask & (NFS_ACL|NFS_ACLCNT)) {
+		acl = get_acl(inode, ACL_TYPE_ACCESS);
+		if (acl == NULL) {
+			/* Solaris returns the inode's minimum ACL. */
+			acl = posix_acl_from_mode(inode->i_mode, GFP_KERNEL);
+		}
+		if (IS_ERR(acl)) {
+			resp->status = nfserrno(PTR_ERR(acl));
+			goto fail;
+		}
+		resp->acl_access = acl;
+	}
+	if (resp->mask & (NFS_DFACL|NFS_DFACLCNT)) {
+		/* Check how Solaris handles requests for the Default ACL
+		   of a non-directory! */
+		acl = get_acl(inode, ACL_TYPE_DEFAULT);
+		if (IS_ERR(acl)) {
+			resp->status = nfserrno(PTR_ERR(acl));
+			goto fail;
+		}
+		resp->acl_default = acl;
+	}
+
+	/* resp->acl_{access,default} are released in nfssvc_release_getacl. */
+out:
+	return rpc_success;
+
+fail:
+	posix_acl_release(resp->acl_access);
+	posix_acl_release(resp->acl_default);
+	goto out;
+}
+
+/*
+ * Set the Access and/or Default ACL of a file.
+ */
+static __be32 nfsacld_proc_setacl(struct svc_rqst *rqstp)
+{
+	struct nfsd3_setaclargs *argp = rqstp->rq_argp;
+	struct nfsd_attrstat *resp = rqstp->rq_resp;
+	struct inode *inode;
+	svc_fh *fh;
+	int error;
+
+	dprintk("nfsd: SETACL(2acl)   %s\n", SVCFH_fmt(&argp->fh));
+
+	fh = fh_copy(&resp->fh, &argp->fh);
+	resp->status = fh_verify(rqstp, &resp->fh, 0, NFSD_MAY_SATTR);
+	if (resp->status != nfs_ok)
+		goto out;
+
+	inode = d_inode(fh->fh_dentry);
+
+	error = fh_want_write(fh);
+	if (error)
+		goto out_errno;
+
+	fh_lock(fh);
+
+	error = set_posix_acl(inode, ACL_TYPE_ACCESS, argp->acl_access);
+	if (error)
+		goto out_drop_lock;
+	error = set_posix_acl(inode, ACL_TYPE_DEFAULT, argp->acl_default);
+	if (error)
+		goto out_drop_lock;
+
+	fh_unlock(fh);
+
+	fh_drop_write(fh);
+
+	resp->status = fh_getattr(fh, &resp->stat);
+
+out:
+	/* argp->acl_{access,default} may have been allocated in
+	   nfssvc_decode_setaclargs. */
+	posix_acl_release(argp->acl_access);
+	posix_acl_release(argp->acl_default);
+	return rpc_success;
+
+out_drop_lock:
+	fh_unlock(fh);
+	fh_drop_write(fh);
+out_errno:
+	resp->status = nfserrno(error);
+	goto out;
+}
+
+/*
+ * Check file attributes
+ */
+static __be32 nfsacld_proc_getattr(struct svc_rqst *rqstp)
+{
+	struct nfsd_fhandle *argp = rqstp->rq_argp;
+	struct nfsd_attrstat *resp = rqstp->rq_resp;
+
+	dprintk("nfsd: GETATTR  %s\n", SVCFH_fmt(&argp->fh));
+
+	fh_copy(&resp->fh, &argp->fh);
+	resp->status = fh_verify(rqstp, &resp->fh, 0, NFSD_MAY_NOP);
+	if (resp->status != nfs_ok)
+		goto out;
+	resp->status = fh_getattr(&resp->fh, &resp->stat);
+out:
+	return rpc_success;
+}
+
+/*
+ * Check file access
+ */
+static __be32 nfsacld_proc_access(struct svc_rqst *rqstp)
+{
+	struct nfsd3_accessargs *argp = rqstp->rq_argp;
+	struct nfsd3_accessres *resp = rqstp->rq_resp;
+
+	dprintk("nfsd: ACCESS(2acl)   %s 0x%x\n",
+			SVCFH_fmt(&argp->fh),
+			argp->access);
+
+	fh_copy(&resp->fh, &argp->fh);
+	resp->access = argp->access;
+	resp->status = nfsd_access(rqstp, &resp->fh, &resp->access, NULL);
+	if (resp->status != nfs_ok)
+		goto out;
+	resp->status = fh_getattr(&resp->fh, &resp->stat);
+out:
+	return rpc_success;
+}
+
+/*
+ * XDR decode functions
+ */
+static int nfsaclsvc_decode_voidarg(struct svc_rqst *rqstp, __be32 *p)
+{
+	return 1;
+}
+
+static int nfsaclsvc_decode_getaclargs(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd3_getaclargs *argp = rqstp->rq_argp;
+
+	p = nfs2svc_decode_fh(p, &argp->fh);
+	if (!p)
+		return 0;
+	argp->mask = ntohl(*p); p++;
+
+	return xdr_argsize_check(rqstp, p);
+}
+
+
+static int nfsaclsvc_decode_setaclargs(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd3_setaclargs *argp = rqstp->rq_argp;
+	struct kvec *head = rqstp->rq_arg.head;
+	unsigned int base;
+	int n;
+
+	p = nfs2svc_decode_fh(p, &argp->fh);
+	if (!p)
+		return 0;
+	argp->mask = ntohl(*p++);
+	if (argp->mask & ~NFS_ACL_MASK ||
+	    !xdr_argsize_check(rqstp, p))
+		return 0;
+
+	base = (char *)p - (char *)head->iov_base;
+	n = nfsacl_decode(&rqstp->rq_arg, base, NULL,
+			  (argp->mask & NFS_ACL) ?
+			  &argp->acl_access : NULL);
+	if (n > 0)
+		n = nfsacl_decode(&rqstp->rq_arg, base + n, NULL,
+				  (argp->mask & NFS_DFACL) ?
+				  &argp->acl_default : NULL);
+	return (n > 0);
+}
+
+static int nfsaclsvc_decode_fhandleargs(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd_fhandle *argp = rqstp->rq_argp;
+
+	p = nfs2svc_decode_fh(p, &argp->fh);
+	if (!p)
+		return 0;
+	return xdr_argsize_check(rqstp, p);
+}
+
+static int nfsaclsvc_decode_accessargs(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd3_accessargs *argp = rqstp->rq_argp;
+
+	p = nfs2svc_decode_fh(p, &argp->fh);
+	if (!p)
+		return 0;
+	argp->access = ntohl(*p++);
+
+	return xdr_argsize_check(rqstp, p);
+}
+
+/*
+ * XDR encode functions
+ */
+
+/*
+ * There must be an encoding function for void results so svc_process
+ * will work properly.
+ */
+static int nfsaclsvc_encode_voidres(struct svc_rqst *rqstp, __be32 *p)
+{
+	return xdr_ressize_check(rqstp, p);
+}
+
+/* GETACL */
+static int nfsaclsvc_encode_getaclres(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd3_getaclres *resp = rqstp->rq_resp;
+	struct dentry *dentry = resp->fh.fh_dentry;
+	struct inode *inode;
+	struct kvec *head = rqstp->rq_res.head;
+	unsigned int base;
+	int n;
+	int w;
+
+	*p++ = resp->status;
+	if (resp->status != nfs_ok)
+		return xdr_ressize_check(rqstp, p);
+
+	/*
+	 * Since this is version 2, the check for nfserr in
+	 * nfsd_dispatch actually ensures the following cannot happen.
+	 * However, it seems fragile to depend on that.
+	 */
+	if (dentry == NULL || d_really_is_negative(dentry))
+		return 0;
+	inode = d_inode(dentry);
+
+	p = nfs2svc_encode_fattr(rqstp, p, &resp->fh, &resp->stat);
+	*p++ = htonl(resp->mask);
+	if (!xdr_ressize_check(rqstp, p))
+		return 0;
+	base = (char *)p - (char *)head->iov_base;
+
+	rqstp->rq_res.page_len = w = nfsacl_size(
+		(resp->mask & NFS_ACL)   ? resp->acl_access  : NULL,
+		(resp->mask & NFS_DFACL) ? resp->acl_default : NULL);
+	while (w > 0) {
+		if (!*(rqstp->rq_next_page++))
+			return 0;
+		w -= PAGE_SIZE;
+	}
+
+	n = nfsacl_encode(&rqstp->rq_res, base, inode,
+			  resp->acl_access,
+			  resp->mask & NFS_ACL, 0);
+	if (n > 0)
+		n = nfsacl_encode(&rqstp->rq_res, base + n, inode,
+				  resp->acl_default,
+				  resp->mask & NFS_DFACL,
+				  NFS_ACL_DEFAULT);
+	return (n > 0);
+}
+
+static int nfsaclsvc_encode_attrstatres(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd_attrstat *resp = rqstp->rq_resp;
+
+	*p++ = resp->status;
+	if (resp->status != nfs_ok)
+		goto out;
+
+	p = nfs2svc_encode_fattr(rqstp, p, &resp->fh, &resp->stat);
+out:
+	return xdr_ressize_check(rqstp, p);
+}
+
+/* ACCESS */
+static int nfsaclsvc_encode_accessres(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd3_accessres *resp = rqstp->rq_resp;
+
+	*p++ = resp->status;
+	if (resp->status != nfs_ok)
+		goto out;
+
+	p = nfs2svc_encode_fattr(rqstp, p, &resp->fh, &resp->stat);
+	*p++ = htonl(resp->access);
+out:
+	return xdr_ressize_check(rqstp, p);
+}
+
+/*
+ * XDR release functions
+ */
+static void nfsaclsvc_release_getacl(struct svc_rqst *rqstp)
+{
+	struct nfsd3_getaclres *resp = rqstp->rq_resp;
+
+	fh_put(&resp->fh);
+	posix_acl_release(resp->acl_access);
+	posix_acl_release(resp->acl_default);
+}
+
+static void nfsaclsvc_release_attrstat(struct svc_rqst *rqstp)
+{
+	struct nfsd_attrstat *resp = rqstp->rq_resp;
+
+	fh_put(&resp->fh);
+}
+
+static void nfsaclsvc_release_access(struct svc_rqst *rqstp)
+{
+	struct nfsd3_accessres *resp = rqstp->rq_resp;
+
+	fh_put(&resp->fh);
+}
+
+struct nfsd3_voidargs { int dummy; };
+
+#define ST 1		/* status*/
+#define AT 21		/* attributes */
+#define pAT (1+AT)	/* post attributes - conditional */
+#define ACL (1+NFS_ACL_MAX_ENTRIES*3)  /* Access Control List */
+
+static const struct svc_procedure nfsd_acl_procedures2[5] = {
+	[ACLPROC2_NULL] = {
+		.pc_func = nfsacld_proc_null,
+		.pc_decode = nfsaclsvc_decode_voidarg,
+		.pc_encode = nfsaclsvc_encode_voidres,
+		.pc_argsize = sizeof(struct nfsd3_voidargs),
+		.pc_ressize = sizeof(struct nfsd3_voidargs),
+		.pc_cachetype = RC_NOCACHE,
+		.pc_xdrressize = ST,
+	},
+	[ACLPROC2_GETACL] = {
+		.pc_func = nfsacld_proc_getacl,
+		.pc_decode = nfsaclsvc_decode_getaclargs,
+		.pc_encode = nfsaclsvc_encode_getaclres,
+		.pc_release = nfsaclsvc_release_getacl,
+		.pc_argsize = sizeof(struct nfsd3_getaclargs),
+		.pc_ressize = sizeof(struct nfsd3_getaclres),
+		.pc_cachetype = RC_NOCACHE,
+		.pc_xdrressize = ST+1+2*(1+ACL),
+	},
+	[ACLPROC2_SETACL] = {
+		.pc_func = nfsacld_proc_setacl,
+		.pc_decode = nfsaclsvc_decode_setaclargs,
+		.pc_encode = nfsaclsvc_encode_attrstatres,
+		.pc_release = nfsaclsvc_release_attrstat,
+		.pc_argsize = sizeof(struct nfsd3_setaclargs),
+		.pc_ressize = sizeof(struct nfsd_attrstat),
+		.pc_cachetype = RC_NOCACHE,
+		.pc_xdrressize = ST+AT,
+	},
+	[ACLPROC2_GETATTR] = {
+		.pc_func = nfsacld_proc_getattr,
+		.pc_decode = nfsaclsvc_decode_fhandleargs,
+		.pc_encode = nfsaclsvc_encode_attrstatres,
+		.pc_release = nfsaclsvc_release_attrstat,
+		.pc_argsize = sizeof(struct nfsd_fhandle),
+		.pc_ressize = sizeof(struct nfsd_attrstat),
+		.pc_cachetype = RC_NOCACHE,
+		.pc_xdrressize = ST+AT,
+	},
+	[ACLPROC2_ACCESS] = {
+		.pc_func = nfsacld_proc_access,
+		.pc_decode = nfsaclsvc_decode_accessargs,
+		.pc_encode = nfsaclsvc_encode_accessres,
+		.pc_release = nfsaclsvc_release_access,
+		.pc_argsize = sizeof(struct nfsd3_accessargs),
+		.pc_ressize = sizeof(struct nfsd3_accessres),
+		.pc_cachetype = RC_NOCACHE,
+		.pc_xdrressize = ST+AT+1,
+	},
+};
+
+static unsigned int nfsd_acl_count2[ARRAY_SIZE(nfsd_acl_procedures2)];
+const struct svc_version nfsd_acl_version2 = {
+	.vs_vers	= 2,
+	.vs_nproc	= 5,
+	.vs_proc	= nfsd_acl_procedures2,
+	.vs_count	= nfsd_acl_count2,
+	.vs_dispatch	= nfsd_dispatch,
+	.vs_xdrsize	= NFS3_SVC_XDRSIZE,
+};
diff --git a/fs/nfsd/nfs3acl.c b/fs/nfsd/nfs3acl.c
new file mode 100644
index 000000000..34a394e50
--- /dev/null
+++ b/fs/nfsd/nfs3acl.c
@@ -0,0 +1,286 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Process version 3 NFSACL requests.
+ *
+ * Copyright (C) 2002-2003 Andreas Gruenbacher <agruen@suse.de>
+ */
+
+#include "nfsd.h"
+/* FIXME: nfsacl.h is a broken header */
+#include <linux/nfsacl.h>
+#include <linux/gfp.h>
+#include "cache.h"
+#include "xdr3.h"
+#include "vfs.h"
+
+/*
+ * NULL call.
+ */
+static __be32
+nfsd3_proc_null(struct svc_rqst *rqstp)
+{
+	return rpc_success;
+}
+
+/*
+ * Get the Access and/or Default ACL of a file.
+ */
+static __be32 nfsd3_proc_getacl(struct svc_rqst *rqstp)
+{
+	struct nfsd3_getaclargs *argp = rqstp->rq_argp;
+	struct nfsd3_getaclres *resp = rqstp->rq_resp;
+	struct posix_acl *acl;
+	struct inode *inode;
+	svc_fh *fh;
+
+	fh = fh_copy(&resp->fh, &argp->fh);
+	resp->status = fh_verify(rqstp, &resp->fh, 0, NFSD_MAY_NOP);
+	if (resp->status != nfs_ok)
+		goto out;
+
+	inode = d_inode(fh->fh_dentry);
+
+	if (argp->mask & ~NFS_ACL_MASK) {
+		resp->status = nfserr_inval;
+		goto out;
+	}
+	resp->mask = argp->mask;
+
+	if (resp->mask & (NFS_ACL|NFS_ACLCNT)) {
+		acl = get_acl(inode, ACL_TYPE_ACCESS);
+		if (acl == NULL) {
+			/* Solaris returns the inode's minimum ACL. */
+			acl = posix_acl_from_mode(inode->i_mode, GFP_KERNEL);
+		}
+		if (IS_ERR(acl)) {
+			resp->status = nfserrno(PTR_ERR(acl));
+			goto fail;
+		}
+		resp->acl_access = acl;
+	}
+	if (resp->mask & (NFS_DFACL|NFS_DFACLCNT)) {
+		/* Check how Solaris handles requests for the Default ACL
+		   of a non-directory! */
+		acl = get_acl(inode, ACL_TYPE_DEFAULT);
+		if (IS_ERR(acl)) {
+			resp->status = nfserrno(PTR_ERR(acl));
+			goto fail;
+		}
+		resp->acl_default = acl;
+	}
+
+	/* resp->acl_{access,default} are released in nfs3svc_release_getacl. */
+out:
+	return rpc_success;
+
+fail:
+	posix_acl_release(resp->acl_access);
+	posix_acl_release(resp->acl_default);
+	goto out;
+}
+
+/*
+ * Set the Access and/or Default ACL of a file.
+ */
+static __be32 nfsd3_proc_setacl(struct svc_rqst *rqstp)
+{
+	struct nfsd3_setaclargs *argp = rqstp->rq_argp;
+	struct nfsd3_attrstat *resp = rqstp->rq_resp;
+	struct inode *inode;
+	svc_fh *fh;
+	int error;
+
+	fh = fh_copy(&resp->fh, &argp->fh);
+	resp->status = fh_verify(rqstp, &resp->fh, 0, NFSD_MAY_SATTR);
+	if (resp->status != nfs_ok)
+		goto out;
+
+	inode = d_inode(fh->fh_dentry);
+
+	error = fh_want_write(fh);
+	if (error)
+		goto out_errno;
+
+	fh_lock(fh);
+
+	error = set_posix_acl(inode, ACL_TYPE_ACCESS, argp->acl_access);
+	if (error)
+		goto out_drop_lock;
+	error = set_posix_acl(inode, ACL_TYPE_DEFAULT, argp->acl_default);
+
+out_drop_lock:
+	fh_unlock(fh);
+	fh_drop_write(fh);
+out_errno:
+	resp->status = nfserrno(error);
+out:
+	/* argp->acl_{access,default} may have been allocated in
+	   nfs3svc_decode_setaclargs. */
+	posix_acl_release(argp->acl_access);
+	posix_acl_release(argp->acl_default);
+	return rpc_success;
+}
+
+/*
+ * XDR decode functions
+ */
+static int nfs3svc_decode_getaclargs(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd3_getaclargs *args = rqstp->rq_argp;
+
+	p = nfs3svc_decode_fh(p, &args->fh);
+	if (!p)
+		return 0;
+	args->mask = ntohl(*p); p++;
+
+	return xdr_argsize_check(rqstp, p);
+}
+
+
+static int nfs3svc_decode_setaclargs(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd3_setaclargs *args = rqstp->rq_argp;
+	struct kvec *head = rqstp->rq_arg.head;
+	unsigned int base;
+	int n;
+
+	p = nfs3svc_decode_fh(p, &args->fh);
+	if (!p)
+		return 0;
+	args->mask = ntohl(*p++);
+	if (args->mask & ~NFS_ACL_MASK ||
+	    !xdr_argsize_check(rqstp, p))
+		return 0;
+
+	base = (char *)p - (char *)head->iov_base;
+	n = nfsacl_decode(&rqstp->rq_arg, base, NULL,
+			  (args->mask & NFS_ACL) ?
+			  &args->acl_access : NULL);
+	if (n > 0)
+		n = nfsacl_decode(&rqstp->rq_arg, base + n, NULL,
+				  (args->mask & NFS_DFACL) ?
+				  &args->acl_default : NULL);
+	return (n > 0);
+}
+
+/*
+ * XDR encode functions
+ */
+
+/* GETACL */
+static int nfs3svc_encode_getaclres(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd3_getaclres *resp = rqstp->rq_resp;
+	struct dentry *dentry = resp->fh.fh_dentry;
+
+	*p++ = resp->status;
+	p = nfs3svc_encode_post_op_attr(rqstp, p, &resp->fh);
+	if (resp->status == 0 && dentry && d_really_is_positive(dentry)) {
+		struct inode *inode = d_inode(dentry);
+		struct kvec *head = rqstp->rq_res.head;
+		unsigned int base;
+		int n;
+		int w;
+
+		*p++ = htonl(resp->mask);
+		if (!xdr_ressize_check(rqstp, p))
+			return 0;
+		base = (char *)p - (char *)head->iov_base;
+
+		rqstp->rq_res.page_len = w = nfsacl_size(
+			(resp->mask & NFS_ACL)   ? resp->acl_access  : NULL,
+			(resp->mask & NFS_DFACL) ? resp->acl_default : NULL);
+		while (w > 0) {
+			if (!*(rqstp->rq_next_page++))
+				return 0;
+			w -= PAGE_SIZE;
+		}
+
+		n = nfsacl_encode(&rqstp->rq_res, base, inode,
+				  resp->acl_access,
+				  resp->mask & NFS_ACL, 0);
+		if (n > 0)
+			n = nfsacl_encode(&rqstp->rq_res, base + n, inode,
+					  resp->acl_default,
+					  resp->mask & NFS_DFACL,
+					  NFS_ACL_DEFAULT);
+		if (n <= 0)
+			return 0;
+	} else
+		if (!xdr_ressize_check(rqstp, p))
+			return 0;
+
+	return 1;
+}
+
+/* SETACL */
+static int nfs3svc_encode_setaclres(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd3_attrstat *resp = rqstp->rq_resp;
+
+	*p++ = resp->status;
+	p = nfs3svc_encode_post_op_attr(rqstp, p, &resp->fh);
+	return xdr_ressize_check(rqstp, p);
+}
+
+/*
+ * XDR release functions
+ */
+static void nfs3svc_release_getacl(struct svc_rqst *rqstp)
+{
+	struct nfsd3_getaclres *resp = rqstp->rq_resp;
+
+	fh_put(&resp->fh);
+	posix_acl_release(resp->acl_access);
+	posix_acl_release(resp->acl_default);
+}
+
+struct nfsd3_voidargs { int dummy; };
+
+#define ST 1		/* status*/
+#define AT 21		/* attributes */
+#define pAT (1+AT)	/* post attributes - conditional */
+#define ACL (1+NFS_ACL_MAX_ENTRIES*3)  /* Access Control List */
+
+static const struct svc_procedure nfsd_acl_procedures3[3] = {
+	[ACLPROC3_NULL] = {
+		.pc_func = nfsd3_proc_null,
+		.pc_decode = nfs3svc_decode_voidarg,
+		.pc_encode = nfs3svc_encode_voidres,
+		.pc_argsize = sizeof(struct nfsd3_voidargs),
+		.pc_ressize = sizeof(struct nfsd3_voidargs),
+		.pc_cachetype = RC_NOCACHE,
+		.pc_xdrressize = ST,
+	},
+	[ACLPROC3_GETACL] = {
+		.pc_func = nfsd3_proc_getacl,
+		.pc_decode = nfs3svc_decode_getaclargs,
+		.pc_encode = nfs3svc_encode_getaclres,
+		.pc_release = nfs3svc_release_getacl,
+		.pc_argsize = sizeof(struct nfsd3_getaclargs),
+		.pc_ressize = sizeof(struct nfsd3_getaclres),
+		.pc_cachetype = RC_NOCACHE,
+		.pc_xdrressize = ST+1+2*(1+ACL),
+	},
+	[ACLPROC3_SETACL] = {
+		.pc_func = nfsd3_proc_setacl,
+		.pc_decode = nfs3svc_decode_setaclargs,
+		.pc_encode = nfs3svc_encode_setaclres,
+		.pc_release = nfs3svc_release_fhandle,
+		.pc_argsize = sizeof(struct nfsd3_setaclargs),
+		.pc_ressize = sizeof(struct nfsd3_attrstat),
+		.pc_cachetype = RC_NOCACHE,
+		.pc_xdrressize = ST+pAT,
+	},
+};
+
+static unsigned int nfsd_acl_count3[ARRAY_SIZE(nfsd_acl_procedures3)];
+const struct svc_version nfsd_acl_version3 = {
+	.vs_vers	= 3,
+	.vs_nproc	= 3,
+	.vs_proc	= nfsd_acl_procedures3,
+	.vs_count	= nfsd_acl_count3,
+	.vs_dispatch	= nfsd_dispatch,
+	.vs_xdrsize	= NFS3_SVC_XDRSIZE,
+};
+
diff --git a/fs/nfsd/nfs3proc.c b/fs/nfsd/nfs3proc.c
new file mode 100644
index 000000000..981a4e4c9
--- /dev/null
+++ b/fs/nfsd/nfs3proc.c
@@ -0,0 +1,935 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Process version 3 NFS requests.
+ *
+ * Copyright (C) 1996, 1997, 1998 Olaf Kirch <okir@monad.swb.de>
+ */
+
+#include <linux/fs.h>
+#include <linux/ext2_fs.h>
+#include <linux/magic.h>
+
+#include "cache.h"
+#include "xdr3.h"
+#include "vfs.h"
+
+#define NFSDDBG_FACILITY		NFSDDBG_PROC
+
+static int	nfs3_ftypes[] = {
+	0,			/* NF3NON */
+	S_IFREG,		/* NF3REG */
+	S_IFDIR,		/* NF3DIR */
+	S_IFBLK,		/* NF3BLK */
+	S_IFCHR,		/* NF3CHR */
+	S_IFLNK,		/* NF3LNK */
+	S_IFSOCK,		/* NF3SOCK */
+	S_IFIFO,		/* NF3FIFO */
+};
+
+/*
+ * NULL call.
+ */
+static __be32
+nfsd3_proc_null(struct svc_rqst *rqstp)
+{
+	return rpc_success;
+}
+
+/*
+ * Get a file's attributes
+ */
+static __be32
+nfsd3_proc_getattr(struct svc_rqst *rqstp)
+{
+	struct nfsd_fhandle *argp = rqstp->rq_argp;
+	struct nfsd3_attrstat *resp = rqstp->rq_resp;
+
+	dprintk("nfsd: GETATTR(3)  %s\n",
+		SVCFH_fmt(&argp->fh));
+
+	fh_copy(&resp->fh, &argp->fh);
+	resp->status = fh_verify(rqstp, &resp->fh, 0,
+				 NFSD_MAY_NOP | NFSD_MAY_BYPASS_GSS_ON_ROOT);
+	if (resp->status != nfs_ok)
+		goto out;
+
+	resp->status = fh_getattr(&resp->fh, &resp->stat);
+out:
+	return rpc_success;
+}
+
+/*
+ * Set a file's attributes
+ */
+static __be32
+nfsd3_proc_setattr(struct svc_rqst *rqstp)
+{
+	struct nfsd3_sattrargs *argp = rqstp->rq_argp;
+	struct nfsd3_attrstat *resp = rqstp->rq_resp;
+
+	dprintk("nfsd: SETATTR(3)  %s\n",
+				SVCFH_fmt(&argp->fh));
+
+	fh_copy(&resp->fh, &argp->fh);
+	resp->status = nfsd_setattr(rqstp, &resp->fh, &argp->attrs,
+				    argp->check_guard, argp->guardtime);
+	return rpc_success;
+}
+
+/*
+ * Look up a path name component
+ */
+static __be32
+nfsd3_proc_lookup(struct svc_rqst *rqstp)
+{
+	struct nfsd3_diropargs *argp = rqstp->rq_argp;
+	struct nfsd3_diropres  *resp = rqstp->rq_resp;
+
+	dprintk("nfsd: LOOKUP(3)   %s %.*s\n",
+				SVCFH_fmt(&argp->fh),
+				argp->len,
+				argp->name);
+
+	fh_copy(&resp->dirfh, &argp->fh);
+	fh_init(&resp->fh, NFS3_FHSIZE);
+
+	resp->status = nfsd_lookup(rqstp, &resp->dirfh,
+				   argp->name, argp->len,
+				   &resp->fh);
+	return rpc_success;
+}
+
+/*
+ * Check file access
+ */
+static __be32
+nfsd3_proc_access(struct svc_rqst *rqstp)
+{
+	struct nfsd3_accessargs *argp = rqstp->rq_argp;
+	struct nfsd3_accessres *resp = rqstp->rq_resp;
+
+	dprintk("nfsd: ACCESS(3)   %s 0x%x\n",
+				SVCFH_fmt(&argp->fh),
+				argp->access);
+
+	fh_copy(&resp->fh, &argp->fh);
+	resp->access = argp->access;
+	resp->status = nfsd_access(rqstp, &resp->fh, &resp->access, NULL);
+	return rpc_success;
+}
+
+/*
+ * Read a symlink.
+ */
+static __be32
+nfsd3_proc_readlink(struct svc_rqst *rqstp)
+{
+	struct nfsd3_readlinkargs *argp = rqstp->rq_argp;
+	struct nfsd3_readlinkres *resp = rqstp->rq_resp;
+
+	dprintk("nfsd: READLINK(3) %s\n", SVCFH_fmt(&argp->fh));
+
+	/* Read the symlink. */
+	fh_copy(&resp->fh, &argp->fh);
+	resp->len = NFS3_MAXPATHLEN;
+	resp->status = nfsd_readlink(rqstp, &resp->fh, argp->buffer, &resp->len);
+	return rpc_success;
+}
+
+/*
+ * Read a portion of a file.
+ */
+static __be32
+nfsd3_proc_read(struct svc_rqst *rqstp)
+{
+	struct nfsd3_readargs *argp = rqstp->rq_argp;
+	struct nfsd3_readres *resp = rqstp->rq_resp;
+	u32	max_blocksize = svc_max_payload(rqstp);
+	unsigned long cnt = min(argp->count, max_blocksize);
+
+	dprintk("nfsd: READ(3) %s %lu bytes at %Lu\n",
+				SVCFH_fmt(&argp->fh),
+				(unsigned long) argp->count,
+				(unsigned long long) argp->offset);
+
+	/* Obtain buffer pointer for payload.
+	 * 1 (status) + 22 (post_op_attr) + 1 (count) + 1 (eof)
+	 * + 1 (xdr opaque byte count) = 26
+	 */
+	resp->count = cnt;
+	svc_reserve_auth(rqstp, ((1 + NFS3_POST_OP_ATTR_WORDS + 3)<<2) + resp->count +4);
+
+	fh_copy(&resp->fh, &argp->fh);
+	resp->status = nfsd_read(rqstp, &resp->fh, argp->offset,
+				 rqstp->rq_vec, argp->vlen, &resp->count,
+				 &resp->eof);
+	return rpc_success;
+}
+
+/*
+ * Write data to a file
+ */
+static __be32
+nfsd3_proc_write(struct svc_rqst *rqstp)
+{
+	struct nfsd3_writeargs *argp = rqstp->rq_argp;
+	struct nfsd3_writeres *resp = rqstp->rq_resp;
+	unsigned long cnt = argp->len;
+	unsigned int nvecs;
+
+	dprintk("nfsd: WRITE(3)    %s %d bytes at %Lu%s\n",
+				SVCFH_fmt(&argp->fh),
+				argp->len,
+				(unsigned long long) argp->offset,
+				argp->stable? " stable" : "");
+
+	resp->status = nfserr_fbig;
+	if (argp->offset > (u64)OFFSET_MAX ||
+	    argp->offset + argp->len > (u64)OFFSET_MAX)
+		return rpc_success;
+
+	fh_copy(&resp->fh, &argp->fh);
+	resp->committed = argp->stable;
+	nvecs = svc_fill_write_vector(rqstp, rqstp->rq_arg.pages,
+				      &argp->first, cnt);
+	if (!nvecs) {
+		resp->status = nfserr_io;
+		goto out;
+	}
+	resp->status = nfsd_write(rqstp, &resp->fh, argp->offset,
+				  rqstp->rq_vec, nvecs, &cnt,
+				  resp->committed, resp->verf);
+	resp->count = cnt;
+out:
+	return rpc_success;
+}
+
+/*
+ * With NFSv3, CREATE processing is a lot easier than with NFSv2.
+ * At least in theory; we'll see how it fares in practice when the
+ * first reports about SunOS compatibility problems start to pour in...
+ */
+static __be32
+nfsd3_proc_create(struct svc_rqst *rqstp)
+{
+	struct nfsd3_createargs *argp = rqstp->rq_argp;
+	struct nfsd3_diropres *resp = rqstp->rq_resp;
+	svc_fh		*dirfhp, *newfhp = NULL;
+	struct iattr	*attr;
+
+	dprintk("nfsd: CREATE(3)   %s %.*s\n",
+				SVCFH_fmt(&argp->fh),
+				argp->len,
+				argp->name);
+
+	dirfhp = fh_copy(&resp->dirfh, &argp->fh);
+	newfhp = fh_init(&resp->fh, NFS3_FHSIZE);
+	attr   = &argp->attrs;
+
+	/* Unfudge the mode bits */
+	attr->ia_mode &= ~S_IFMT;
+	if (!(attr->ia_valid & ATTR_MODE)) { 
+		attr->ia_valid |= ATTR_MODE;
+		attr->ia_mode = S_IFREG;
+	} else {
+		attr->ia_mode = (attr->ia_mode & ~S_IFMT) | S_IFREG;
+	}
+
+	/* Now create the file and set attributes */
+	resp->status = do_nfsd_create(rqstp, dirfhp, argp->name, argp->len,
+				      attr, newfhp, argp->createmode,
+				      (u32 *)argp->verf, NULL, NULL);
+	return rpc_success;
+}
+
+/*
+ * Make directory. This operation is not idempotent.
+ */
+static __be32
+nfsd3_proc_mkdir(struct svc_rqst *rqstp)
+{
+	struct nfsd3_createargs *argp = rqstp->rq_argp;
+	struct nfsd3_diropres *resp = rqstp->rq_resp;
+
+	dprintk("nfsd: MKDIR(3)    %s %.*s\n",
+				SVCFH_fmt(&argp->fh),
+				argp->len,
+				argp->name);
+
+	argp->attrs.ia_valid &= ~ATTR_SIZE;
+	fh_copy(&resp->dirfh, &argp->fh);
+	fh_init(&resp->fh, NFS3_FHSIZE);
+	resp->status = nfsd_create(rqstp, &resp->dirfh, argp->name, argp->len,
+				   &argp->attrs, S_IFDIR, 0, &resp->fh);
+	fh_unlock(&resp->dirfh);
+	return rpc_success;
+}
+
+static __be32
+nfsd3_proc_symlink(struct svc_rqst *rqstp)
+{
+	struct nfsd3_symlinkargs *argp = rqstp->rq_argp;
+	struct nfsd3_diropres *resp = rqstp->rq_resp;
+
+	if (argp->tlen == 0) {
+		resp->status = nfserr_inval;
+		goto out;
+	}
+	if (argp->tlen > NFS3_MAXPATHLEN) {
+		resp->status = nfserr_nametoolong;
+		goto out;
+	}
+
+	argp->tname = svc_fill_symlink_pathname(rqstp, &argp->first,
+						page_address(rqstp->rq_arg.pages[0]),
+						argp->tlen);
+	if (IS_ERR(argp->tname)) {
+		resp->status = nfserrno(PTR_ERR(argp->tname));
+		goto out;
+	}
+
+	dprintk("nfsd: SYMLINK(3)  %s %.*s -> %.*s\n",
+				SVCFH_fmt(&argp->ffh),
+				argp->flen, argp->fname,
+				argp->tlen, argp->tname);
+
+	fh_copy(&resp->dirfh, &argp->ffh);
+	fh_init(&resp->fh, NFS3_FHSIZE);
+	resp->status = nfsd_symlink(rqstp, &resp->dirfh, argp->fname,
+				    argp->flen, argp->tname, &resp->fh);
+	kfree(argp->tname);
+out:
+	return rpc_success;
+}
+
+/*
+ * Make socket/fifo/device.
+ */
+static __be32
+nfsd3_proc_mknod(struct svc_rqst *rqstp)
+{
+	struct nfsd3_mknodargs *argp = rqstp->rq_argp;
+	struct nfsd3_diropres  *resp = rqstp->rq_resp;
+	int type;
+	dev_t	rdev = 0;
+
+	dprintk("nfsd: MKNOD(3)    %s %.*s\n",
+				SVCFH_fmt(&argp->fh),
+				argp->len,
+				argp->name);
+
+	fh_copy(&resp->dirfh, &argp->fh);
+	fh_init(&resp->fh, NFS3_FHSIZE);
+
+	if (argp->ftype == NF3CHR || argp->ftype == NF3BLK) {
+		rdev = MKDEV(argp->major, argp->minor);
+		if (MAJOR(rdev) != argp->major ||
+		    MINOR(rdev) != argp->minor) {
+			resp->status = nfserr_inval;
+			goto out;
+		}
+	} else if (argp->ftype != NF3SOCK && argp->ftype != NF3FIFO) {
+		resp->status = nfserr_badtype;
+		goto out;
+	}
+
+	type = nfs3_ftypes[argp->ftype];
+	resp->status = nfsd_create(rqstp, &resp->dirfh, argp->name, argp->len,
+				   &argp->attrs, type, rdev, &resp->fh);
+	fh_unlock(&resp->dirfh);
+out:
+	return rpc_success;
+}
+
+/*
+ * Remove file/fifo/socket etc.
+ */
+static __be32
+nfsd3_proc_remove(struct svc_rqst *rqstp)
+{
+	struct nfsd3_diropargs *argp = rqstp->rq_argp;
+	struct nfsd3_attrstat *resp = rqstp->rq_resp;
+
+	dprintk("nfsd: REMOVE(3)   %s %.*s\n",
+				SVCFH_fmt(&argp->fh),
+				argp->len,
+				argp->name);
+
+	/* Unlink. -S_IFDIR means file must not be a directory */
+	fh_copy(&resp->fh, &argp->fh);
+	resp->status = nfsd_unlink(rqstp, &resp->fh, -S_IFDIR,
+				   argp->name, argp->len);
+	fh_unlock(&resp->fh);
+	return rpc_success;
+}
+
+/*
+ * Remove a directory
+ */
+static __be32
+nfsd3_proc_rmdir(struct svc_rqst *rqstp)
+{
+	struct nfsd3_diropargs *argp = rqstp->rq_argp;
+	struct nfsd3_attrstat *resp = rqstp->rq_resp;
+
+	dprintk("nfsd: RMDIR(3)    %s %.*s\n",
+				SVCFH_fmt(&argp->fh),
+				argp->len,
+				argp->name);
+
+	fh_copy(&resp->fh, &argp->fh);
+	resp->status = nfsd_unlink(rqstp, &resp->fh, S_IFDIR,
+				   argp->name, argp->len);
+	fh_unlock(&resp->fh);
+	return rpc_success;
+}
+
+static __be32
+nfsd3_proc_rename(struct svc_rqst *rqstp)
+{
+	struct nfsd3_renameargs *argp = rqstp->rq_argp;
+	struct nfsd3_renameres *resp = rqstp->rq_resp;
+
+	dprintk("nfsd: RENAME(3)   %s %.*s ->\n",
+				SVCFH_fmt(&argp->ffh),
+				argp->flen,
+				argp->fname);
+	dprintk("nfsd: -> %s %.*s\n",
+				SVCFH_fmt(&argp->tfh),
+				argp->tlen,
+				argp->tname);
+
+	fh_copy(&resp->ffh, &argp->ffh);
+	fh_copy(&resp->tfh, &argp->tfh);
+	resp->status = nfsd_rename(rqstp, &resp->ffh, argp->fname, argp->flen,
+				   &resp->tfh, argp->tname, argp->tlen);
+	return rpc_success;
+}
+
+static __be32
+nfsd3_proc_link(struct svc_rqst *rqstp)
+{
+	struct nfsd3_linkargs *argp = rqstp->rq_argp;
+	struct nfsd3_linkres  *resp = rqstp->rq_resp;
+
+	dprintk("nfsd: LINK(3)     %s ->\n",
+				SVCFH_fmt(&argp->ffh));
+	dprintk("nfsd:   -> %s %.*s\n",
+				SVCFH_fmt(&argp->tfh),
+				argp->tlen,
+				argp->tname);
+
+	fh_copy(&resp->fh,  &argp->ffh);
+	fh_copy(&resp->tfh, &argp->tfh);
+	resp->status = nfsd_link(rqstp, &resp->tfh, argp->tname, argp->tlen,
+				 &resp->fh);
+	return rpc_success;
+}
+
+/*
+ * Read a portion of a directory.
+ */
+static __be32
+nfsd3_proc_readdir(struct svc_rqst *rqstp)
+{
+	struct nfsd3_readdirargs *argp = rqstp->rq_argp;
+	struct nfsd3_readdirres  *resp = rqstp->rq_resp;
+	int		count = 0;
+	struct page	**p;
+	caddr_t		page_addr = NULL;
+
+	dprintk("nfsd: READDIR(3)  %s %d bytes at %d\n",
+				SVCFH_fmt(&argp->fh),
+				argp->count, (u32) argp->cookie);
+
+	/* Make sure we've room for the NULL ptr & eof flag, and shrink to
+	 * client read size */
+	count = (argp->count >> 2) - 2;
+
+	/* Read directory and encode entries on the fly */
+	fh_copy(&resp->fh, &argp->fh);
+
+	resp->buflen = count;
+	resp->common.err = nfs_ok;
+	resp->buffer = argp->buffer;
+	resp->rqstp = rqstp;
+	resp->status = nfsd_readdir(rqstp, &resp->fh, (loff_t *)&argp->cookie,
+				    &resp->common, nfs3svc_encode_entry);
+	memcpy(resp->verf, argp->verf, 8);
+	count = 0;
+	for (p = rqstp->rq_respages + 1; p < rqstp->rq_next_page; p++) {
+		page_addr = page_address(*p);
+
+		if (((caddr_t)resp->buffer >= page_addr) &&
+		    ((caddr_t)resp->buffer < page_addr + PAGE_SIZE)) {
+			count += (caddr_t)resp->buffer - page_addr;
+			break;
+		}
+		count += PAGE_SIZE;
+	}
+	resp->count = count >> 2;
+	if (resp->offset) {
+		loff_t offset = argp->cookie;
+
+		if (unlikely(resp->offset1)) {
+			/* we ended up with offset on a page boundary */
+			*resp->offset = htonl(offset >> 32);
+			*resp->offset1 = htonl(offset & 0xffffffff);
+			resp->offset1 = NULL;
+		} else {
+			xdr_encode_hyper(resp->offset, offset);
+		}
+		resp->offset = NULL;
+	}
+
+	return rpc_success;
+}
+
+/*
+ * Read a portion of a directory, including file handles and attrs.
+ * For now, we choose to ignore the dircount parameter.
+ */
+static __be32
+nfsd3_proc_readdirplus(struct svc_rqst *rqstp)
+{
+	struct nfsd3_readdirargs *argp = rqstp->rq_argp;
+	struct nfsd3_readdirres  *resp = rqstp->rq_resp;
+	int	count = 0;
+	loff_t	offset;
+	struct page **p;
+	caddr_t	page_addr = NULL;
+
+	dprintk("nfsd: READDIR+(3) %s %d bytes at %d\n",
+				SVCFH_fmt(&argp->fh),
+				argp->count, (u32) argp->cookie);
+
+	/* Convert byte count to number of words (i.e. >> 2),
+	 * and reserve room for the NULL ptr & eof flag (-2 words) */
+	resp->count = (argp->count >> 2) - 2;
+
+	/* Read directory and encode entries on the fly */
+	fh_copy(&resp->fh, &argp->fh);
+
+	resp->common.err = nfs_ok;
+	resp->buffer = argp->buffer;
+	resp->buflen = resp->count;
+	resp->rqstp = rqstp;
+	offset = argp->cookie;
+
+	resp->status = fh_verify(rqstp, &resp->fh, S_IFDIR, NFSD_MAY_NOP);
+	if (resp->status != nfs_ok)
+		goto out;
+
+	if (resp->fh.fh_export->ex_flags & NFSEXP_NOREADDIRPLUS) {
+		resp->status = nfserr_notsupp;
+		goto out;
+	}
+
+	resp->status = nfsd_readdir(rqstp, &resp->fh, &offset,
+				    &resp->common, nfs3svc_encode_entry_plus);
+	memcpy(resp->verf, argp->verf, 8);
+	for (p = rqstp->rq_respages + 1; p < rqstp->rq_next_page; p++) {
+		page_addr = page_address(*p);
+
+		if (((caddr_t)resp->buffer >= page_addr) &&
+		    ((caddr_t)resp->buffer < page_addr + PAGE_SIZE)) {
+			count += (caddr_t)resp->buffer - page_addr;
+			break;
+		}
+		count += PAGE_SIZE;
+	}
+	resp->count = count >> 2;
+	if (resp->offset) {
+		if (unlikely(resp->offset1)) {
+			/* we ended up with offset on a page boundary */
+			*resp->offset = htonl(offset >> 32);
+			*resp->offset1 = htonl(offset & 0xffffffff);
+			resp->offset1 = NULL;
+		} else {
+			xdr_encode_hyper(resp->offset, offset);
+		}
+		resp->offset = NULL;
+	}
+
+out:
+	return rpc_success;
+}
+
+/*
+ * Get file system stats
+ */
+static __be32
+nfsd3_proc_fsstat(struct svc_rqst *rqstp)
+{
+	struct nfsd_fhandle *argp = rqstp->rq_argp;
+	struct nfsd3_fsstatres *resp = rqstp->rq_resp;
+
+	dprintk("nfsd: FSSTAT(3)   %s\n",
+				SVCFH_fmt(&argp->fh));
+
+	resp->status = nfsd_statfs(rqstp, &argp->fh, &resp->stats, 0);
+	fh_put(&argp->fh);
+	return rpc_success;
+}
+
+/*
+ * Get file system info
+ */
+static __be32
+nfsd3_proc_fsinfo(struct svc_rqst *rqstp)
+{
+	struct nfsd_fhandle *argp = rqstp->rq_argp;
+	struct nfsd3_fsinfores *resp = rqstp->rq_resp;
+	u32	max_blocksize = svc_max_payload(rqstp);
+
+	dprintk("nfsd: FSINFO(3)   %s\n",
+				SVCFH_fmt(&argp->fh));
+
+	resp->f_rtmax  = max_blocksize;
+	resp->f_rtpref = max_blocksize;
+	resp->f_rtmult = PAGE_SIZE;
+	resp->f_wtmax  = max_blocksize;
+	resp->f_wtpref = max_blocksize;
+	resp->f_wtmult = PAGE_SIZE;
+	resp->f_dtpref = max_blocksize;
+	resp->f_maxfilesize = ~(u32) 0;
+	resp->f_properties = NFS3_FSF_DEFAULT;
+
+	resp->status = fh_verify(rqstp, &argp->fh, 0,
+				 NFSD_MAY_NOP | NFSD_MAY_BYPASS_GSS_ON_ROOT);
+
+	/* Check special features of the file system. May request
+	 * different read/write sizes for file systems known to have
+	 * problems with large blocks */
+	if (resp->status == nfs_ok) {
+		struct super_block *sb = argp->fh.fh_dentry->d_sb;
+
+		/* Note that we don't care for remote fs's here */
+		if (sb->s_magic == MSDOS_SUPER_MAGIC) {
+			resp->f_properties = NFS3_FSF_BILLYBOY;
+		}
+		resp->f_maxfilesize = sb->s_maxbytes;
+	}
+
+	fh_put(&argp->fh);
+	return rpc_success;
+}
+
+/*
+ * Get pathconf info for the specified file
+ */
+static __be32
+nfsd3_proc_pathconf(struct svc_rqst *rqstp)
+{
+	struct nfsd_fhandle *argp = rqstp->rq_argp;
+	struct nfsd3_pathconfres *resp = rqstp->rq_resp;
+
+	dprintk("nfsd: PATHCONF(3) %s\n",
+				SVCFH_fmt(&argp->fh));
+
+	/* Set default pathconf */
+	resp->p_link_max = 255;		/* at least */
+	resp->p_name_max = 255;		/* at least */
+	resp->p_no_trunc = 0;
+	resp->p_chown_restricted = 1;
+	resp->p_case_insensitive = 0;
+	resp->p_case_preserving = 1;
+
+	resp->status = fh_verify(rqstp, &argp->fh, 0, NFSD_MAY_NOP);
+
+	if (resp->status == nfs_ok) {
+		struct super_block *sb = argp->fh.fh_dentry->d_sb;
+
+		/* Note that we don't care for remote fs's here */
+		switch (sb->s_magic) {
+		case EXT2_SUPER_MAGIC:
+			resp->p_link_max = EXT2_LINK_MAX;
+			resp->p_name_max = EXT2_NAME_LEN;
+			break;
+		case MSDOS_SUPER_MAGIC:
+			resp->p_case_insensitive = 1;
+			resp->p_case_preserving  = 0;
+			break;
+		}
+	}
+
+	fh_put(&argp->fh);
+	return rpc_success;
+}
+
+/*
+ * Commit a file (range) to stable storage.
+ */
+static __be32
+nfsd3_proc_commit(struct svc_rqst *rqstp)
+{
+	struct nfsd3_commitargs *argp = rqstp->rq_argp;
+	struct nfsd3_commitres *resp = rqstp->rq_resp;
+
+	dprintk("nfsd: COMMIT(3)   %s %u@%Lu\n",
+				SVCFH_fmt(&argp->fh),
+				argp->count,
+				(unsigned long long) argp->offset);
+
+	if (argp->offset > NFS_OFFSET_MAX) {
+		resp->status = nfserr_inval;
+		goto out;
+	}
+
+	fh_copy(&resp->fh, &argp->fh);
+	resp->status = nfsd_commit(rqstp, &resp->fh, argp->offset,
+				   argp->count, resp->verf);
+out:
+	return rpc_success;
+}
+
+
+/*
+ * NFSv3 Server procedures.
+ * Only the results of non-idempotent operations are cached.
+ */
+#define nfs3svc_decode_fhandleargs	nfs3svc_decode_fhandle
+#define nfs3svc_encode_attrstatres	nfs3svc_encode_attrstat
+#define nfs3svc_encode_wccstatres	nfs3svc_encode_wccstat
+#define nfsd3_mkdirargs			nfsd3_createargs
+#define nfsd3_readdirplusargs		nfsd3_readdirargs
+#define nfsd3_fhandleargs		nfsd_fhandle
+#define nfsd3_fhandleres		nfsd3_attrstat
+#define nfsd3_attrstatres		nfsd3_attrstat
+#define nfsd3_wccstatres		nfsd3_attrstat
+#define nfsd3_createres			nfsd3_diropres
+#define nfsd3_voidres			nfsd3_voidargs
+struct nfsd3_voidargs { int dummy; };
+
+#define ST 1		/* status*/
+#define FH 17		/* filehandle with length */
+#define AT 21		/* attributes */
+#define pAT (1+AT)	/* post attributes - conditional */
+#define WC (7+pAT)	/* WCC attributes */
+
+static const struct svc_procedure nfsd_procedures3[22] = {
+	[NFS3PROC_NULL] = {
+		.pc_func = nfsd3_proc_null,
+		.pc_decode = nfs3svc_decode_voidarg,
+		.pc_encode = nfs3svc_encode_voidres,
+		.pc_argsize = sizeof(struct nfsd3_voidargs),
+		.pc_ressize = sizeof(struct nfsd3_voidres),
+		.pc_cachetype = RC_NOCACHE,
+		.pc_xdrressize = ST,
+	},
+	[NFS3PROC_GETATTR] = {
+		.pc_func = nfsd3_proc_getattr,
+		.pc_decode = nfs3svc_decode_fhandleargs,
+		.pc_encode = nfs3svc_encode_attrstatres,
+		.pc_release = nfs3svc_release_fhandle,
+		.pc_argsize = sizeof(struct nfsd3_fhandleargs),
+		.pc_ressize = sizeof(struct nfsd3_attrstatres),
+		.pc_cachetype = RC_NOCACHE,
+		.pc_xdrressize = ST+AT,
+	},
+	[NFS3PROC_SETATTR] = {
+		.pc_func = nfsd3_proc_setattr,
+		.pc_decode = nfs3svc_decode_sattrargs,
+		.pc_encode = nfs3svc_encode_wccstatres,
+		.pc_release = nfs3svc_release_fhandle,
+		.pc_argsize = sizeof(struct nfsd3_sattrargs),
+		.pc_ressize = sizeof(struct nfsd3_wccstatres),
+		.pc_cachetype = RC_REPLBUFF,
+		.pc_xdrressize = ST+WC,
+	},
+	[NFS3PROC_LOOKUP] = {
+		.pc_func = nfsd3_proc_lookup,
+		.pc_decode = nfs3svc_decode_diropargs,
+		.pc_encode = nfs3svc_encode_diropres,
+		.pc_release = nfs3svc_release_fhandle2,
+		.pc_argsize = sizeof(struct nfsd3_diropargs),
+		.pc_ressize = sizeof(struct nfsd3_diropres),
+		.pc_cachetype = RC_NOCACHE,
+		.pc_xdrressize = ST+FH+pAT+pAT,
+	},
+	[NFS3PROC_ACCESS] = {
+		.pc_func = nfsd3_proc_access,
+		.pc_decode = nfs3svc_decode_accessargs,
+		.pc_encode = nfs3svc_encode_accessres,
+		.pc_release = nfs3svc_release_fhandle,
+		.pc_argsize = sizeof(struct nfsd3_accessargs),
+		.pc_ressize = sizeof(struct nfsd3_accessres),
+		.pc_cachetype = RC_NOCACHE,
+		.pc_xdrressize = ST+pAT+1,
+	},
+	[NFS3PROC_READLINK] = {
+		.pc_func = nfsd3_proc_readlink,
+		.pc_decode = nfs3svc_decode_readlinkargs,
+		.pc_encode = nfs3svc_encode_readlinkres,
+		.pc_release = nfs3svc_release_fhandle,
+		.pc_argsize = sizeof(struct nfsd3_readlinkargs),
+		.pc_ressize = sizeof(struct nfsd3_readlinkres),
+		.pc_cachetype = RC_NOCACHE,
+		.pc_xdrressize = ST+pAT+1+NFS3_MAXPATHLEN/4,
+	},
+	[NFS3PROC_READ] = {
+		.pc_func = nfsd3_proc_read,
+		.pc_decode = nfs3svc_decode_readargs,
+		.pc_encode = nfs3svc_encode_readres,
+		.pc_release = nfs3svc_release_fhandle,
+		.pc_argsize = sizeof(struct nfsd3_readargs),
+		.pc_ressize = sizeof(struct nfsd3_readres),
+		.pc_cachetype = RC_NOCACHE,
+		.pc_xdrressize = ST+pAT+4+NFSSVC_MAXBLKSIZE/4,
+	},
+	[NFS3PROC_WRITE] = {
+		.pc_func = nfsd3_proc_write,
+		.pc_decode = nfs3svc_decode_writeargs,
+		.pc_encode = nfs3svc_encode_writeres,
+		.pc_release = nfs3svc_release_fhandle,
+		.pc_argsize = sizeof(struct nfsd3_writeargs),
+		.pc_ressize = sizeof(struct nfsd3_writeres),
+		.pc_cachetype = RC_REPLBUFF,
+		.pc_xdrressize = ST+WC+4,
+	},
+	[NFS3PROC_CREATE] = {
+		.pc_func = nfsd3_proc_create,
+		.pc_decode = nfs3svc_decode_createargs,
+		.pc_encode = nfs3svc_encode_createres,
+		.pc_release = nfs3svc_release_fhandle2,
+		.pc_argsize = sizeof(struct nfsd3_createargs),
+		.pc_ressize = sizeof(struct nfsd3_createres),
+		.pc_cachetype = RC_REPLBUFF,
+		.pc_xdrressize = ST+(1+FH+pAT)+WC,
+	},
+	[NFS3PROC_MKDIR] = {
+		.pc_func = nfsd3_proc_mkdir,
+		.pc_decode = nfs3svc_decode_mkdirargs,
+		.pc_encode = nfs3svc_encode_createres,
+		.pc_release = nfs3svc_release_fhandle2,
+		.pc_argsize = sizeof(struct nfsd3_mkdirargs),
+		.pc_ressize = sizeof(struct nfsd3_createres),
+		.pc_cachetype = RC_REPLBUFF,
+		.pc_xdrressize = ST+(1+FH+pAT)+WC,
+	},
+	[NFS3PROC_SYMLINK] = {
+		.pc_func = nfsd3_proc_symlink,
+		.pc_decode = nfs3svc_decode_symlinkargs,
+		.pc_encode = nfs3svc_encode_createres,
+		.pc_release = nfs3svc_release_fhandle2,
+		.pc_argsize = sizeof(struct nfsd3_symlinkargs),
+		.pc_ressize = sizeof(struct nfsd3_createres),
+		.pc_cachetype = RC_REPLBUFF,
+		.pc_xdrressize = ST+(1+FH+pAT)+WC,
+	},
+	[NFS3PROC_MKNOD] = {
+		.pc_func = nfsd3_proc_mknod,
+		.pc_decode = nfs3svc_decode_mknodargs,
+		.pc_encode = nfs3svc_encode_createres,
+		.pc_release = nfs3svc_release_fhandle2,
+		.pc_argsize = sizeof(struct nfsd3_mknodargs),
+		.pc_ressize = sizeof(struct nfsd3_createres),
+		.pc_cachetype = RC_REPLBUFF,
+		.pc_xdrressize = ST+(1+FH+pAT)+WC,
+	},
+	[NFS3PROC_REMOVE] = {
+		.pc_func = nfsd3_proc_remove,
+		.pc_decode = nfs3svc_decode_diropargs,
+		.pc_encode = nfs3svc_encode_wccstatres,
+		.pc_release = nfs3svc_release_fhandle,
+		.pc_argsize = sizeof(struct nfsd3_diropargs),
+		.pc_ressize = sizeof(struct nfsd3_wccstatres),
+		.pc_cachetype = RC_REPLBUFF,
+		.pc_xdrressize = ST+WC,
+	},
+	[NFS3PROC_RMDIR] = {
+		.pc_func = nfsd3_proc_rmdir,
+		.pc_decode = nfs3svc_decode_diropargs,
+		.pc_encode = nfs3svc_encode_wccstatres,
+		.pc_release = nfs3svc_release_fhandle,
+		.pc_argsize = sizeof(struct nfsd3_diropargs),
+		.pc_ressize = sizeof(struct nfsd3_wccstatres),
+		.pc_cachetype = RC_REPLBUFF,
+		.pc_xdrressize = ST+WC,
+	},
+	[NFS3PROC_RENAME] = {
+		.pc_func = nfsd3_proc_rename,
+		.pc_decode = nfs3svc_decode_renameargs,
+		.pc_encode = nfs3svc_encode_renameres,
+		.pc_release = nfs3svc_release_fhandle2,
+		.pc_argsize = sizeof(struct nfsd3_renameargs),
+		.pc_ressize = sizeof(struct nfsd3_renameres),
+		.pc_cachetype = RC_REPLBUFF,
+		.pc_xdrressize = ST+WC+WC,
+	},
+	[NFS3PROC_LINK] = {
+		.pc_func = nfsd3_proc_link,
+		.pc_decode = nfs3svc_decode_linkargs,
+		.pc_encode = nfs3svc_encode_linkres,
+		.pc_release = nfs3svc_release_fhandle2,
+		.pc_argsize = sizeof(struct nfsd3_linkargs),
+		.pc_ressize = sizeof(struct nfsd3_linkres),
+		.pc_cachetype = RC_REPLBUFF,
+		.pc_xdrressize = ST+pAT+WC,
+	},
+	[NFS3PROC_READDIR] = {
+		.pc_func = nfsd3_proc_readdir,
+		.pc_decode = nfs3svc_decode_readdirargs,
+		.pc_encode = nfs3svc_encode_readdirres,
+		.pc_release = nfs3svc_release_fhandle,
+		.pc_argsize = sizeof(struct nfsd3_readdirargs),
+		.pc_ressize = sizeof(struct nfsd3_readdirres),
+		.pc_cachetype = RC_NOCACHE,
+	},
+	[NFS3PROC_READDIRPLUS] = {
+		.pc_func = nfsd3_proc_readdirplus,
+		.pc_decode = nfs3svc_decode_readdirplusargs,
+		.pc_encode = nfs3svc_encode_readdirres,
+		.pc_release = nfs3svc_release_fhandle,
+		.pc_argsize = sizeof(struct nfsd3_readdirplusargs),
+		.pc_ressize = sizeof(struct nfsd3_readdirres),
+		.pc_cachetype = RC_NOCACHE,
+	},
+	[NFS3PROC_FSSTAT] = {
+		.pc_func = nfsd3_proc_fsstat,
+		.pc_decode = nfs3svc_decode_fhandleargs,
+		.pc_encode = nfs3svc_encode_fsstatres,
+		.pc_argsize = sizeof(struct nfsd3_fhandleargs),
+		.pc_ressize = sizeof(struct nfsd3_fsstatres),
+		.pc_cachetype = RC_NOCACHE,
+		.pc_xdrressize = ST+pAT+2*6+1,
+	},
+	[NFS3PROC_FSINFO] = {
+		.pc_func = nfsd3_proc_fsinfo,
+		.pc_decode = nfs3svc_decode_fhandleargs,
+		.pc_encode = nfs3svc_encode_fsinfores,
+		.pc_argsize = sizeof(struct nfsd3_fhandleargs),
+		.pc_ressize = sizeof(struct nfsd3_fsinfores),
+		.pc_cachetype = RC_NOCACHE,
+		.pc_xdrressize = ST+pAT+12,
+	},
+	[NFS3PROC_PATHCONF] = {
+		.pc_func = nfsd3_proc_pathconf,
+		.pc_decode = nfs3svc_decode_fhandleargs,
+		.pc_encode = nfs3svc_encode_pathconfres,
+		.pc_argsize = sizeof(struct nfsd3_fhandleargs),
+		.pc_ressize = sizeof(struct nfsd3_pathconfres),
+		.pc_cachetype = RC_NOCACHE,
+		.pc_xdrressize = ST+pAT+6,
+	},
+	[NFS3PROC_COMMIT] = {
+		.pc_func = nfsd3_proc_commit,
+		.pc_decode = nfs3svc_decode_commitargs,
+		.pc_encode = nfs3svc_encode_commitres,
+		.pc_release = nfs3svc_release_fhandle,
+		.pc_argsize = sizeof(struct nfsd3_commitargs),
+		.pc_ressize = sizeof(struct nfsd3_commitres),
+		.pc_cachetype = RC_NOCACHE,
+		.pc_xdrressize = ST+WC+2,
+	},
+};
+
+static unsigned int nfsd_count3[ARRAY_SIZE(nfsd_procedures3)];
+const struct svc_version nfsd_version3 = {
+	.vs_vers	= 3,
+	.vs_nproc	= 22,
+	.vs_proc	= nfsd_procedures3,
+	.vs_dispatch	= nfsd_dispatch,
+	.vs_count	= nfsd_count3,
+	.vs_xdrsize	= NFS3_SVC_XDRSIZE,
+};
diff --git a/fs/nfsd/nfs3xdr.c b/fs/nfsd/nfs3xdr.c
new file mode 100644
index 000000000..716566da4
--- /dev/null
+++ b/fs/nfsd/nfs3xdr.c
@@ -0,0 +1,1171 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * XDR support for nfsd/protocol version 3.
+ *
+ * Copyright (C) 1995, 1996, 1997 Olaf Kirch <okir@monad.swb.de>
+ *
+ * 2003-08-09 Jamie Lokier: Use htonl() for nanoseconds, not htons()!
+ */
+
+#include <linux/namei.h>
+#include <linux/sunrpc/svc_xprt.h>
+#include "xdr3.h"
+#include "auth.h"
+#include "netns.h"
+#include "vfs.h"
+
+#define NFSDDBG_FACILITY		NFSDDBG_XDR
+
+
+/*
+ * Mapping of S_IF* types to NFS file types
+ */
+static u32	nfs3_ftypes[] = {
+	NF3NON,  NF3FIFO, NF3CHR, NF3BAD,
+	NF3DIR,  NF3BAD,  NF3BLK, NF3BAD,
+	NF3REG,  NF3BAD,  NF3LNK, NF3BAD,
+	NF3SOCK, NF3BAD,  NF3LNK, NF3BAD,
+};
+
+
+/*
+ * XDR functions for basic NFS types
+ */
+static __be32 *
+encode_time3(__be32 *p, struct timespec64 *time)
+{
+	*p++ = htonl((u32) time->tv_sec); *p++ = htonl(time->tv_nsec);
+	return p;
+}
+
+static __be32 *
+decode_time3(__be32 *p, struct timespec64 *time)
+{
+	time->tv_sec = ntohl(*p++);
+	time->tv_nsec = ntohl(*p++);
+	return p;
+}
+
+static __be32 *
+decode_fh(__be32 *p, struct svc_fh *fhp)
+{
+	unsigned int size;
+	fh_init(fhp, NFS3_FHSIZE);
+	size = ntohl(*p++);
+	if (size > NFS3_FHSIZE)
+		return NULL;
+
+	memcpy(&fhp->fh_handle.fh_base, p, size);
+	fhp->fh_handle.fh_size = size;
+	return p + XDR_QUADLEN(size);
+}
+
+/* Helper function for NFSv3 ACL code */
+__be32 *nfs3svc_decode_fh(__be32 *p, struct svc_fh *fhp)
+{
+	return decode_fh(p, fhp);
+}
+
+static __be32 *
+encode_fh(__be32 *p, struct svc_fh *fhp)
+{
+	unsigned int size = fhp->fh_handle.fh_size;
+	*p++ = htonl(size);
+	if (size) p[XDR_QUADLEN(size)-1]=0;
+	memcpy(p, &fhp->fh_handle.fh_base, size);
+	return p + XDR_QUADLEN(size);
+}
+
+/*
+ * Decode a file name and make sure that the path contains
+ * no slashes or null bytes.
+ */
+static __be32 *
+decode_filename(__be32 *p, char **namp, unsigned int *lenp)
+{
+	char		*name;
+	unsigned int	i;
+
+	if ((p = xdr_decode_string_inplace(p, namp, lenp, NFS3_MAXNAMLEN)) != NULL) {
+		for (i = 0, name = *namp; i < *lenp; i++, name++) {
+			if (*name == '\0' || *name == '/')
+				return NULL;
+		}
+	}
+
+	return p;
+}
+
+static __be32 *
+decode_sattr3(__be32 *p, struct iattr *iap, struct user_namespace *userns)
+{
+	u32	tmp;
+
+	iap->ia_valid = 0;
+
+	if (*p++) {
+		iap->ia_valid |= ATTR_MODE;
+		iap->ia_mode = ntohl(*p++);
+	}
+	if (*p++) {
+		iap->ia_uid = make_kuid(userns, ntohl(*p++));
+		if (uid_valid(iap->ia_uid))
+			iap->ia_valid |= ATTR_UID;
+	}
+	if (*p++) {
+		iap->ia_gid = make_kgid(userns, ntohl(*p++));
+		if (gid_valid(iap->ia_gid))
+			iap->ia_valid |= ATTR_GID;
+	}
+	if (*p++) {
+		u64	newsize;
+
+		iap->ia_valid |= ATTR_SIZE;
+		p = xdr_decode_hyper(p, &newsize);
+		iap->ia_size = min_t(u64, newsize, NFS_OFFSET_MAX);
+	}
+	if ((tmp = ntohl(*p++)) == 1) {	/* set to server time */
+		iap->ia_valid |= ATTR_ATIME;
+	} else if (tmp == 2) {		/* set to client time */
+		iap->ia_valid |= ATTR_ATIME | ATTR_ATIME_SET;
+		iap->ia_atime.tv_sec = ntohl(*p++);
+		iap->ia_atime.tv_nsec = ntohl(*p++);
+	}
+	if ((tmp = ntohl(*p++)) == 1) {	/* set to server time */
+		iap->ia_valid |= ATTR_MTIME;
+	} else if (tmp == 2) {		/* set to client time */
+		iap->ia_valid |= ATTR_MTIME | ATTR_MTIME_SET;
+		iap->ia_mtime.tv_sec = ntohl(*p++);
+		iap->ia_mtime.tv_nsec = ntohl(*p++);
+	}
+	return p;
+}
+
+static __be32 *encode_fsid(__be32 *p, struct svc_fh *fhp)
+{
+	u64 f;
+	switch(fsid_source(fhp)) {
+	default:
+	case FSIDSOURCE_DEV:
+		p = xdr_encode_hyper(p, (u64)huge_encode_dev
+				     (fhp->fh_dentry->d_sb->s_dev));
+		break;
+	case FSIDSOURCE_FSID:
+		p = xdr_encode_hyper(p, (u64) fhp->fh_export->ex_fsid);
+		break;
+	case FSIDSOURCE_UUID:
+		f = ((u64*)fhp->fh_export->ex_uuid)[0];
+		f ^= ((u64*)fhp->fh_export->ex_uuid)[1];
+		p = xdr_encode_hyper(p, f);
+		break;
+	}
+	return p;
+}
+
+static __be32 *
+encode_fattr3(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp,
+	      struct kstat *stat)
+{
+	struct user_namespace *userns = nfsd_user_namespace(rqstp);
+	*p++ = htonl(nfs3_ftypes[(stat->mode & S_IFMT) >> 12]);
+	*p++ = htonl((u32) (stat->mode & S_IALLUGO));
+	*p++ = htonl((u32) stat->nlink);
+	*p++ = htonl((u32) from_kuid_munged(userns, stat->uid));
+	*p++ = htonl((u32) from_kgid_munged(userns, stat->gid));
+	if (S_ISLNK(stat->mode) && stat->size > NFS3_MAXPATHLEN) {
+		p = xdr_encode_hyper(p, (u64) NFS3_MAXPATHLEN);
+	} else {
+		p = xdr_encode_hyper(p, (u64) stat->size);
+	}
+	p = xdr_encode_hyper(p, ((u64)stat->blocks) << 9);
+	*p++ = htonl((u32) MAJOR(stat->rdev));
+	*p++ = htonl((u32) MINOR(stat->rdev));
+	p = encode_fsid(p, fhp);
+	p = xdr_encode_hyper(p, stat->ino);
+	p = encode_time3(p, &stat->atime);
+	p = encode_time3(p, &stat->mtime);
+	p = encode_time3(p, &stat->ctime);
+
+	return p;
+}
+
+static __be32 *
+encode_saved_post_attr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp)
+{
+	/* Attributes to follow */
+	*p++ = xdr_one;
+	return encode_fattr3(rqstp, p, fhp, &fhp->fh_post_attr);
+}
+
+/*
+ * Encode post-operation attributes.
+ * The inode may be NULL if the call failed because of a stale file
+ * handle. In this case, no attributes are returned.
+ */
+static __be32 *
+encode_post_op_attr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp)
+{
+	struct dentry *dentry = fhp->fh_dentry;
+	if (dentry && d_really_is_positive(dentry)) {
+	        __be32 err;
+		struct kstat stat;
+
+		err = fh_getattr(fhp, &stat);
+		if (!err) {
+			*p++ = xdr_one;		/* attributes follow */
+			lease_get_mtime(d_inode(dentry), &stat.mtime);
+			return encode_fattr3(rqstp, p, fhp, &stat);
+		}
+	}
+	*p++ = xdr_zero;
+	return p;
+}
+
+/* Helper for NFSv3 ACLs */
+__be32 *
+nfs3svc_encode_post_op_attr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp)
+{
+	return encode_post_op_attr(rqstp, p, fhp);
+}
+
+/*
+ * Enocde weak cache consistency data
+ */
+static __be32 *
+encode_wcc_data(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp)
+{
+	struct dentry	*dentry = fhp->fh_dentry;
+
+	if (dentry && d_really_is_positive(dentry) && fhp->fh_post_saved) {
+		if (fhp->fh_pre_saved) {
+			*p++ = xdr_one;
+			p = xdr_encode_hyper(p, (u64) fhp->fh_pre_size);
+			p = encode_time3(p, &fhp->fh_pre_mtime);
+			p = encode_time3(p, &fhp->fh_pre_ctime);
+		} else {
+			*p++ = xdr_zero;
+		}
+		return encode_saved_post_attr(rqstp, p, fhp);
+	}
+	/* no pre- or post-attrs */
+	*p++ = xdr_zero;
+	return encode_post_op_attr(rqstp, p, fhp);
+}
+
+/*
+ * Fill in the pre_op attr for the wcc data
+ */
+void fill_pre_wcc(struct svc_fh *fhp)
+{
+	struct inode    *inode;
+	struct kstat	stat;
+	__be32 err;
+
+	if (fhp->fh_pre_saved)
+		return;
+
+	inode = d_inode(fhp->fh_dentry);
+	err = fh_getattr(fhp, &stat);
+	if (err) {
+		/* Grab the times from inode anyway */
+		stat.mtime = inode->i_mtime;
+		stat.ctime = inode->i_ctime;
+		stat.size  = inode->i_size;
+	}
+
+	fhp->fh_pre_mtime = stat.mtime;
+	fhp->fh_pre_ctime = stat.ctime;
+	fhp->fh_pre_size  = stat.size;
+	fhp->fh_pre_change = nfsd4_change_attribute(&stat, inode);
+	fhp->fh_pre_saved = true;
+}
+
+/*
+ * Fill in the post_op attr for the wcc data
+ */
+void fill_post_wcc(struct svc_fh *fhp)
+{
+	__be32 err;
+
+	if (fhp->fh_post_saved)
+		printk("nfsd: inode locked twice during operation.\n");
+
+	err = fh_getattr(fhp, &fhp->fh_post_attr);
+	fhp->fh_post_change = nfsd4_change_attribute(&fhp->fh_post_attr,
+						     d_inode(fhp->fh_dentry));
+	if (err) {
+		fhp->fh_post_saved = false;
+		/* Grab the ctime anyway - set_change_info might use it */
+		fhp->fh_post_attr.ctime = d_inode(fhp->fh_dentry)->i_ctime;
+	} else
+		fhp->fh_post_saved = true;
+}
+
+/*
+ * XDR decode functions
+ */
+int
+nfs3svc_decode_voidarg(struct svc_rqst *rqstp, __be32 *p)
+{
+	return 1;
+}
+
+int
+nfs3svc_decode_fhandle(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd_fhandle *args = rqstp->rq_argp;
+
+	p = decode_fh(p, &args->fh);
+	if (!p)
+		return 0;
+	return xdr_argsize_check(rqstp, p);
+}
+
+int
+nfs3svc_decode_sattrargs(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd3_sattrargs *args = rqstp->rq_argp;
+
+	p = decode_fh(p, &args->fh);
+	if (!p)
+		return 0;
+	p = decode_sattr3(p, &args->attrs, nfsd_user_namespace(rqstp));
+
+	if ((args->check_guard = ntohl(*p++)) != 0) { 
+		struct timespec64 time;
+		p = decode_time3(p, &time);
+		args->guardtime = time.tv_sec;
+	}
+
+	return xdr_argsize_check(rqstp, p);
+}
+
+int
+nfs3svc_decode_diropargs(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd3_diropargs *args = rqstp->rq_argp;
+
+	if (!(p = decode_fh(p, &args->fh))
+	 || !(p = decode_filename(p, &args->name, &args->len)))
+		return 0;
+
+	return xdr_argsize_check(rqstp, p);
+}
+
+int
+nfs3svc_decode_accessargs(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd3_accessargs *args = rqstp->rq_argp;
+
+	p = decode_fh(p, &args->fh);
+	if (!p)
+		return 0;
+	args->access = ntohl(*p++);
+
+	return xdr_argsize_check(rqstp, p);
+}
+
+int
+nfs3svc_decode_readargs(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd3_readargs *args = rqstp->rq_argp;
+	unsigned int len;
+	int v;
+	u32 max_blocksize = svc_max_payload(rqstp);
+
+	p = decode_fh(p, &args->fh);
+	if (!p)
+		return 0;
+	p = xdr_decode_hyper(p, &args->offset);
+
+	args->count = ntohl(*p++);
+	len = min(args->count, max_blocksize);
+
+	/* set up the kvec */
+	v=0;
+	while (len > 0) {
+		struct page *p = *(rqstp->rq_next_page++);
+
+		rqstp->rq_vec[v].iov_base = page_address(p);
+		rqstp->rq_vec[v].iov_len = min_t(unsigned int, len, PAGE_SIZE);
+		len -= rqstp->rq_vec[v].iov_len;
+		v++;
+	}
+	args->vlen = v;
+	return xdr_argsize_check(rqstp, p);
+}
+
+int
+nfs3svc_decode_writeargs(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd3_writeargs *args = rqstp->rq_argp;
+	unsigned int len, hdr, dlen;
+	u32 max_blocksize = svc_max_payload(rqstp);
+	struct kvec *head = rqstp->rq_arg.head;
+	struct kvec *tail = rqstp->rq_arg.tail;
+
+	p = decode_fh(p, &args->fh);
+	if (!p)
+		return 0;
+	p = xdr_decode_hyper(p, &args->offset);
+
+	args->count = ntohl(*p++);
+	args->stable = ntohl(*p++);
+	len = args->len = ntohl(*p++);
+	if ((void *)p > head->iov_base + head->iov_len)
+		return 0;
+	/*
+	 * The count must equal the amount of data passed.
+	 */
+	if (args->count != args->len)
+		return 0;
+
+	/*
+	 * Check to make sure that we got the right number of
+	 * bytes.
+	 */
+	hdr = (void*)p - head->iov_base;
+	dlen = head->iov_len + rqstp->rq_arg.page_len + tail->iov_len - hdr;
+	/*
+	 * Round the length of the data which was specified up to
+	 * the next multiple of XDR units and then compare that
+	 * against the length which was actually received.
+	 * Note that when RPCSEC/GSS (for example) is used, the
+	 * data buffer can be padded so dlen might be larger
+	 * than required.  It must never be smaller.
+	 */
+	if (dlen < XDR_QUADLEN(len)*4)
+		return 0;
+
+	if (args->count > max_blocksize) {
+		args->count = max_blocksize;
+		len = args->len = max_blocksize;
+	}
+
+	args->first.iov_base = (void *)p;
+	args->first.iov_len = head->iov_len - hdr;
+	return 1;
+}
+
+int
+nfs3svc_decode_createargs(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd3_createargs *args = rqstp->rq_argp;
+
+	if (!(p = decode_fh(p, &args->fh))
+	 || !(p = decode_filename(p, &args->name, &args->len)))
+		return 0;
+
+	switch (args->createmode = ntohl(*p++)) {
+	case NFS3_CREATE_UNCHECKED:
+	case NFS3_CREATE_GUARDED:
+		p = decode_sattr3(p, &args->attrs, nfsd_user_namespace(rqstp));
+		break;
+	case NFS3_CREATE_EXCLUSIVE:
+		args->verf = p;
+		p += 2;
+		break;
+	default:
+		return 0;
+	}
+
+	return xdr_argsize_check(rqstp, p);
+}
+
+int
+nfs3svc_decode_mkdirargs(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd3_createargs *args = rqstp->rq_argp;
+
+	if (!(p = decode_fh(p, &args->fh)) ||
+	    !(p = decode_filename(p, &args->name, &args->len)))
+		return 0;
+	p = decode_sattr3(p, &args->attrs, nfsd_user_namespace(rqstp));
+
+	return xdr_argsize_check(rqstp, p);
+}
+
+int
+nfs3svc_decode_symlinkargs(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd3_symlinkargs *args = rqstp->rq_argp;
+	char *base = (char *)p;
+	size_t dlen;
+
+	if (!(p = decode_fh(p, &args->ffh)) ||
+	    !(p = decode_filename(p, &args->fname, &args->flen)))
+		return 0;
+	p = decode_sattr3(p, &args->attrs, nfsd_user_namespace(rqstp));
+
+	args->tlen = ntohl(*p++);
+
+	args->first.iov_base = p;
+	args->first.iov_len = rqstp->rq_arg.head[0].iov_len;
+	args->first.iov_len -= (char *)p - base;
+
+	dlen = args->first.iov_len + rqstp->rq_arg.page_len +
+	       rqstp->rq_arg.tail[0].iov_len;
+	if (dlen < XDR_QUADLEN(args->tlen) << 2)
+		return 0;
+	return 1;
+}
+
+int
+nfs3svc_decode_mknodargs(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd3_mknodargs *args = rqstp->rq_argp;
+
+	if (!(p = decode_fh(p, &args->fh))
+	 || !(p = decode_filename(p, &args->name, &args->len)))
+		return 0;
+
+	args->ftype = ntohl(*p++);
+
+	if (args->ftype == NF3BLK  || args->ftype == NF3CHR
+	 || args->ftype == NF3SOCK || args->ftype == NF3FIFO)
+		p = decode_sattr3(p, &args->attrs, nfsd_user_namespace(rqstp));
+
+	if (args->ftype == NF3BLK || args->ftype == NF3CHR) {
+		args->major = ntohl(*p++);
+		args->minor = ntohl(*p++);
+	}
+
+	return xdr_argsize_check(rqstp, p);
+}
+
+int
+nfs3svc_decode_renameargs(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd3_renameargs *args = rqstp->rq_argp;
+
+	if (!(p = decode_fh(p, &args->ffh))
+	 || !(p = decode_filename(p, &args->fname, &args->flen))
+	 || !(p = decode_fh(p, &args->tfh))
+	 || !(p = decode_filename(p, &args->tname, &args->tlen)))
+		return 0;
+
+	return xdr_argsize_check(rqstp, p);
+}
+
+int
+nfs3svc_decode_readlinkargs(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd3_readlinkargs *args = rqstp->rq_argp;
+
+	p = decode_fh(p, &args->fh);
+	if (!p)
+		return 0;
+	args->buffer = page_address(*(rqstp->rq_next_page++));
+
+	return xdr_argsize_check(rqstp, p);
+}
+
+int
+nfs3svc_decode_linkargs(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd3_linkargs *args = rqstp->rq_argp;
+
+	if (!(p = decode_fh(p, &args->ffh))
+	 || !(p = decode_fh(p, &args->tfh))
+	 || !(p = decode_filename(p, &args->tname, &args->tlen)))
+		return 0;
+
+	return xdr_argsize_check(rqstp, p);
+}
+
+int
+nfs3svc_decode_readdirargs(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd3_readdirargs *args = rqstp->rq_argp;
+	int len;
+	u32 max_blocksize = svc_max_payload(rqstp);
+
+	p = decode_fh(p, &args->fh);
+	if (!p)
+		return 0;
+	p = xdr_decode_hyper(p, &args->cookie);
+	args->verf   = p; p += 2;
+	args->dircount = ~0;
+	args->count  = ntohl(*p++);
+	len = args->count  = min_t(u32, args->count, max_blocksize);
+
+	while (len > 0) {
+		struct page *p = *(rqstp->rq_next_page++);
+		if (!args->buffer)
+			args->buffer = page_address(p);
+		len -= PAGE_SIZE;
+	}
+
+	return xdr_argsize_check(rqstp, p);
+}
+
+int
+nfs3svc_decode_readdirplusargs(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd3_readdirargs *args = rqstp->rq_argp;
+	int len;
+	u32 max_blocksize = svc_max_payload(rqstp);
+
+	p = decode_fh(p, &args->fh);
+	if (!p)
+		return 0;
+	p = xdr_decode_hyper(p, &args->cookie);
+	args->verf     = p; p += 2;
+	args->dircount = ntohl(*p++);
+	args->count    = ntohl(*p++);
+
+	len = args->count = min(args->count, max_blocksize);
+	while (len > 0) {
+		struct page *p = *(rqstp->rq_next_page++);
+		if (!args->buffer)
+			args->buffer = page_address(p);
+		len -= PAGE_SIZE;
+	}
+
+	return xdr_argsize_check(rqstp, p);
+}
+
+int
+nfs3svc_decode_commitargs(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd3_commitargs *args = rqstp->rq_argp;
+	p = decode_fh(p, &args->fh);
+	if (!p)
+		return 0;
+	p = xdr_decode_hyper(p, &args->offset);
+	args->count = ntohl(*p++);
+
+	return xdr_argsize_check(rqstp, p);
+}
+
+/*
+ * XDR encode functions
+ */
+
+int
+nfs3svc_encode_voidres(struct svc_rqst *rqstp, __be32 *p)
+{
+	return xdr_ressize_check(rqstp, p);
+}
+
+/* GETATTR */
+int
+nfs3svc_encode_attrstat(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd3_attrstat *resp = rqstp->rq_resp;
+
+	*p++ = resp->status;
+	if (resp->status == 0) {
+		lease_get_mtime(d_inode(resp->fh.fh_dentry),
+				&resp->stat.mtime);
+		p = encode_fattr3(rqstp, p, &resp->fh, &resp->stat);
+	}
+	return xdr_ressize_check(rqstp, p);
+}
+
+/* SETATTR, REMOVE, RMDIR */
+int
+nfs3svc_encode_wccstat(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd3_attrstat *resp = rqstp->rq_resp;
+
+	*p++ = resp->status;
+	p = encode_wcc_data(rqstp, p, &resp->fh);
+	return xdr_ressize_check(rqstp, p);
+}
+
+/* LOOKUP */
+int
+nfs3svc_encode_diropres(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd3_diropres *resp = rqstp->rq_resp;
+
+	*p++ = resp->status;
+	if (resp->status == 0) {
+		p = encode_fh(p, &resp->fh);
+		p = encode_post_op_attr(rqstp, p, &resp->fh);
+	}
+	p = encode_post_op_attr(rqstp, p, &resp->dirfh);
+	return xdr_ressize_check(rqstp, p);
+}
+
+/* ACCESS */
+int
+nfs3svc_encode_accessres(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd3_accessres *resp = rqstp->rq_resp;
+
+	*p++ = resp->status;
+	p = encode_post_op_attr(rqstp, p, &resp->fh);
+	if (resp->status == 0)
+		*p++ = htonl(resp->access);
+	return xdr_ressize_check(rqstp, p);
+}
+
+/* READLINK */
+int
+nfs3svc_encode_readlinkres(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd3_readlinkres *resp = rqstp->rq_resp;
+
+	*p++ = resp->status;
+	p = encode_post_op_attr(rqstp, p, &resp->fh);
+	if (resp->status == 0) {
+		*p++ = htonl(resp->len);
+		xdr_ressize_check(rqstp, p);
+		rqstp->rq_res.page_len = resp->len;
+		if (resp->len & 3) {
+			/* need to pad the tail */
+			rqstp->rq_res.tail[0].iov_base = p;
+			*p = 0;
+			rqstp->rq_res.tail[0].iov_len = 4 - (resp->len&3);
+		}
+		return 1;
+	} else
+		return xdr_ressize_check(rqstp, p);
+}
+
+/* READ */
+int
+nfs3svc_encode_readres(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd3_readres *resp = rqstp->rq_resp;
+
+	*p++ = resp->status;
+	p = encode_post_op_attr(rqstp, p, &resp->fh);
+	if (resp->status == 0) {
+		*p++ = htonl(resp->count);
+		*p++ = htonl(resp->eof);
+		*p++ = htonl(resp->count);	/* xdr opaque count */
+		xdr_ressize_check(rqstp, p);
+		/* now update rqstp->rq_res to reflect data as well */
+		rqstp->rq_res.page_len = resp->count;
+		if (resp->count & 3) {
+			/* need to pad the tail */
+			rqstp->rq_res.tail[0].iov_base = p;
+			*p = 0;
+			rqstp->rq_res.tail[0].iov_len = 4 - (resp->count & 3);
+		}
+		return 1;
+	} else
+		return xdr_ressize_check(rqstp, p);
+}
+
+/* WRITE */
+int
+nfs3svc_encode_writeres(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd3_writeres *resp = rqstp->rq_resp;
+
+	*p++ = resp->status;
+	p = encode_wcc_data(rqstp, p, &resp->fh);
+	if (resp->status == 0) {
+		*p++ = htonl(resp->count);
+		*p++ = htonl(resp->committed);
+		*p++ = resp->verf[0];
+		*p++ = resp->verf[1];
+	}
+	return xdr_ressize_check(rqstp, p);
+}
+
+/* CREATE, MKDIR, SYMLINK, MKNOD */
+int
+nfs3svc_encode_createres(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd3_diropres *resp = rqstp->rq_resp;
+
+	*p++ = resp->status;
+	if (resp->status == 0) {
+		*p++ = xdr_one;
+		p = encode_fh(p, &resp->fh);
+		p = encode_post_op_attr(rqstp, p, &resp->fh);
+	}
+	p = encode_wcc_data(rqstp, p, &resp->dirfh);
+	return xdr_ressize_check(rqstp, p);
+}
+
+/* RENAME */
+int
+nfs3svc_encode_renameres(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd3_renameres *resp = rqstp->rq_resp;
+
+	*p++ = resp->status;
+	p = encode_wcc_data(rqstp, p, &resp->ffh);
+	p = encode_wcc_data(rqstp, p, &resp->tfh);
+	return xdr_ressize_check(rqstp, p);
+}
+
+/* LINK */
+int
+nfs3svc_encode_linkres(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd3_linkres *resp = rqstp->rq_resp;
+
+	*p++ = resp->status;
+	p = encode_post_op_attr(rqstp, p, &resp->fh);
+	p = encode_wcc_data(rqstp, p, &resp->tfh);
+	return xdr_ressize_check(rqstp, p);
+}
+
+/* READDIR */
+int
+nfs3svc_encode_readdirres(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd3_readdirres *resp = rqstp->rq_resp;
+
+	*p++ = resp->status;
+	p = encode_post_op_attr(rqstp, p, &resp->fh);
+
+	if (resp->status == 0) {
+		/* stupid readdir cookie */
+		memcpy(p, resp->verf, 8); p += 2;
+		xdr_ressize_check(rqstp, p);
+		if (rqstp->rq_res.head[0].iov_len + (2<<2) > PAGE_SIZE)
+			return 1; /*No room for trailer */
+		rqstp->rq_res.page_len = (resp->count) << 2;
+
+		/* add the 'tail' to the end of the 'head' page - page 0. */
+		rqstp->rq_res.tail[0].iov_base = p;
+		*p++ = 0;		/* no more entries */
+		*p++ = htonl(resp->common.err == nfserr_eof);
+		rqstp->rq_res.tail[0].iov_len = 2<<2;
+		return 1;
+	} else
+		return xdr_ressize_check(rqstp, p);
+}
+
+static __be32 *
+encode_entry_baggage(struct nfsd3_readdirres *cd, __be32 *p, const char *name,
+	     int namlen, u64 ino)
+{
+	*p++ = xdr_one;				 /* mark entry present */
+	p    = xdr_encode_hyper(p, ino);	 /* file id */
+	p    = xdr_encode_array(p, name, namlen);/* name length & name */
+
+	cd->offset = p;				/* remember pointer */
+	p = xdr_encode_hyper(p, NFS_OFFSET_MAX);/* offset of next entry */
+
+	return p;
+}
+
+static __be32
+compose_entry_fh(struct nfsd3_readdirres *cd, struct svc_fh *fhp,
+		 const char *name, int namlen, u64 ino)
+{
+	struct svc_export	*exp;
+	struct dentry		*dparent, *dchild;
+	__be32 rv = nfserr_noent;
+
+	dparent = cd->fh.fh_dentry;
+	exp  = cd->fh.fh_export;
+
+	if (isdotent(name, namlen)) {
+		if (namlen == 2) {
+			dchild = dget_parent(dparent);
+			/*
+			 * Don't return filehandle for ".." if we're at
+			 * the filesystem or export root:
+			 */
+			if (dchild == dparent)
+				goto out;
+			if (dparent == exp->ex_path.dentry)
+				goto out;
+		} else
+			dchild = dget(dparent);
+	} else
+		dchild = lookup_positive_unlocked(name, dparent, namlen);
+	if (IS_ERR(dchild))
+		return rv;
+	if (d_mountpoint(dchild))
+		goto out;
+	if (dchild->d_inode->i_ino != ino)
+		goto out;
+	rv = fh_compose(fhp, exp, dchild, &cd->fh);
+out:
+	dput(dchild);
+	return rv;
+}
+
+static __be32 *encode_entryplus_baggage(struct nfsd3_readdirres *cd, __be32 *p, const char *name, int namlen, u64 ino)
+{
+	struct svc_fh	*fh = &cd->scratch;
+	__be32 err;
+
+	fh_init(fh, NFS3_FHSIZE);
+	err = compose_entry_fh(cd, fh, name, namlen, ino);
+	if (err) {
+		*p++ = 0;
+		*p++ = 0;
+		goto out;
+	}
+	p = encode_post_op_attr(cd->rqstp, p, fh);
+	*p++ = xdr_one;			/* yes, a file handle follows */
+	p = encode_fh(p, fh);
+out:
+	fh_put(fh);
+	return p;
+}
+
+/*
+ * Encode a directory entry. This one works for both normal readdir
+ * and readdirplus.
+ * The normal readdir reply requires 2 (fileid) + 1 (stringlen)
+ * + string + 2 (cookie) + 1 (next) words, i.e. 6 + strlen.
+ * 
+ * The readdirplus baggage is 1+21 words for post_op_attr, plus the
+ * file handle.
+ */
+
+#define NFS3_ENTRY_BAGGAGE	(2 + 1 + 2 + 1)
+#define NFS3_ENTRYPLUS_BAGGAGE	(1 + 21 + 1 + (NFS3_FHSIZE >> 2))
+static int
+encode_entry(struct readdir_cd *ccd, const char *name, int namlen,
+	     loff_t offset, u64 ino, unsigned int d_type, int plus)
+{
+	struct nfsd3_readdirres *cd = container_of(ccd, struct nfsd3_readdirres,
+		       					common);
+	__be32		*p = cd->buffer;
+	caddr_t		curr_page_addr = NULL;
+	struct page **	page;
+	int		slen;		/* string (name) length */
+	int		elen;		/* estimated entry length in words */
+	int		num_entry_words = 0;	/* actual number of words */
+
+	if (cd->offset) {
+		u64 offset64 = offset;
+
+		if (unlikely(cd->offset1)) {
+			/* we ended up with offset on a page boundary */
+			*cd->offset = htonl(offset64 >> 32);
+			*cd->offset1 = htonl(offset64 & 0xffffffff);
+			cd->offset1 = NULL;
+		} else {
+			xdr_encode_hyper(cd->offset, offset64);
+		}
+		cd->offset = NULL;
+	}
+
+	/*
+	dprintk("encode_entry(%.*s @%ld%s)\n",
+		namlen, name, (long) offset, plus? " plus" : "");
+	 */
+
+	/* truncate filename if too long */
+	namlen = min(namlen, NFS3_MAXNAMLEN);
+
+	slen = XDR_QUADLEN(namlen);
+	elen = slen + NFS3_ENTRY_BAGGAGE
+		+ (plus? NFS3_ENTRYPLUS_BAGGAGE : 0);
+
+	if (cd->buflen < elen) {
+		cd->common.err = nfserr_toosmall;
+		return -EINVAL;
+	}
+
+	/* determine which page in rq_respages[] we are currently filling */
+	for (page = cd->rqstp->rq_respages + 1;
+				page < cd->rqstp->rq_next_page; page++) {
+		curr_page_addr = page_address(*page);
+
+		if (((caddr_t)cd->buffer >= curr_page_addr) &&
+		    ((caddr_t)cd->buffer <  curr_page_addr + PAGE_SIZE))
+			break;
+	}
+
+	if ((caddr_t)(cd->buffer + elen) < (curr_page_addr + PAGE_SIZE)) {
+		/* encode entry in current page */
+
+		p = encode_entry_baggage(cd, p, name, namlen, ino);
+
+		if (plus)
+			p = encode_entryplus_baggage(cd, p, name, namlen, ino);
+		num_entry_words = p - cd->buffer;
+	} else if (*(page+1) != NULL) {
+		/* temporarily encode entry into next page, then move back to
+		 * current and next page in rq_respages[] */
+		__be32 *p1, *tmp;
+		int len1, len2;
+
+		/* grab next page for temporary storage of entry */
+		p1 = tmp = page_address(*(page+1));
+
+		p1 = encode_entry_baggage(cd, p1, name, namlen, ino);
+
+		if (plus)
+			p1 = encode_entryplus_baggage(cd, p1, name, namlen, ino);
+
+		/* determine entry word length and lengths to go in pages */
+		num_entry_words = p1 - tmp;
+		len1 = curr_page_addr + PAGE_SIZE - (caddr_t)cd->buffer;
+		if ((num_entry_words << 2) < len1) {
+			/* the actual number of words in the entry is less
+			 * than elen and can still fit in the current page
+			 */
+			memmove(p, tmp, num_entry_words << 2);
+			p += num_entry_words;
+
+			/* update offset */
+			cd->offset = cd->buffer + (cd->offset - tmp);
+		} else {
+			unsigned int offset_r = (cd->offset - tmp) << 2;
+
+			/* update pointer to offset location.
+			 * This is a 64bit quantity, so we need to
+			 * deal with 3 cases:
+			 *  -	entirely in first page
+			 *  -	entirely in second page
+			 *  -	4 bytes in each page
+			 */
+			if (offset_r + 8 <= len1) {
+				cd->offset = p + (cd->offset - tmp);
+			} else if (offset_r >= len1) {
+				cd->offset -= len1 >> 2;
+			} else {
+				/* sitting on the fence */
+				BUG_ON(offset_r != len1 - 4);
+				cd->offset = p + (cd->offset - tmp);
+				cd->offset1 = tmp;
+			}
+
+			len2 = (num_entry_words << 2) - len1;
+
+			/* move from temp page to current and next pages */
+			memmove(p, tmp, len1);
+			memmove(tmp, (caddr_t)tmp+len1, len2);
+
+			p = tmp + (len2 >> 2);
+		}
+	}
+	else {
+		cd->common.err = nfserr_toosmall;
+		return -EINVAL;
+	}
+
+	cd->buflen -= num_entry_words;
+	cd->buffer = p;
+	cd->common.err = nfs_ok;
+	return 0;
+
+}
+
+int
+nfs3svc_encode_entry(void *cd, const char *name,
+		     int namlen, loff_t offset, u64 ino, unsigned int d_type)
+{
+	return encode_entry(cd, name, namlen, offset, ino, d_type, 0);
+}
+
+int
+nfs3svc_encode_entry_plus(void *cd, const char *name,
+			  int namlen, loff_t offset, u64 ino,
+			  unsigned int d_type)
+{
+	return encode_entry(cd, name, namlen, offset, ino, d_type, 1);
+}
+
+/* FSSTAT */
+int
+nfs3svc_encode_fsstatres(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd3_fsstatres *resp = rqstp->rq_resp;
+	struct kstatfs	*s = &resp->stats;
+	u64		bs = s->f_bsize;
+
+	*p++ = resp->status;
+	*p++ = xdr_zero;	/* no post_op_attr */
+
+	if (resp->status == 0) {
+		p = xdr_encode_hyper(p, bs * s->f_blocks);	/* total bytes */
+		p = xdr_encode_hyper(p, bs * s->f_bfree);	/* free bytes */
+		p = xdr_encode_hyper(p, bs * s->f_bavail);	/* user available bytes */
+		p = xdr_encode_hyper(p, s->f_files);	/* total inodes */
+		p = xdr_encode_hyper(p, s->f_ffree);	/* free inodes */
+		p = xdr_encode_hyper(p, s->f_ffree);	/* user available inodes */
+		*p++ = htonl(resp->invarsec);	/* mean unchanged time */
+	}
+	return xdr_ressize_check(rqstp, p);
+}
+
+/* FSINFO */
+int
+nfs3svc_encode_fsinfores(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd3_fsinfores *resp = rqstp->rq_resp;
+
+	*p++ = resp->status;
+	*p++ = xdr_zero;	/* no post_op_attr */
+
+	if (resp->status == 0) {
+		*p++ = htonl(resp->f_rtmax);
+		*p++ = htonl(resp->f_rtpref);
+		*p++ = htonl(resp->f_rtmult);
+		*p++ = htonl(resp->f_wtmax);
+		*p++ = htonl(resp->f_wtpref);
+		*p++ = htonl(resp->f_wtmult);
+		*p++ = htonl(resp->f_dtpref);
+		p = xdr_encode_hyper(p, resp->f_maxfilesize);
+		*p++ = xdr_one;
+		*p++ = xdr_zero;
+		*p++ = htonl(resp->f_properties);
+	}
+
+	return xdr_ressize_check(rqstp, p);
+}
+
+/* PATHCONF */
+int
+nfs3svc_encode_pathconfres(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd3_pathconfres *resp = rqstp->rq_resp;
+
+	*p++ = resp->status;
+	*p++ = xdr_zero;	/* no post_op_attr */
+
+	if (resp->status == 0) {
+		*p++ = htonl(resp->p_link_max);
+		*p++ = htonl(resp->p_name_max);
+		*p++ = htonl(resp->p_no_trunc);
+		*p++ = htonl(resp->p_chown_restricted);
+		*p++ = htonl(resp->p_case_insensitive);
+		*p++ = htonl(resp->p_case_preserving);
+	}
+
+	return xdr_ressize_check(rqstp, p);
+}
+
+/* COMMIT */
+int
+nfs3svc_encode_commitres(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd3_commitres *resp = rqstp->rq_resp;
+
+	*p++ = resp->status;
+	p = encode_wcc_data(rqstp, p, &resp->fh);
+	/* Write verifier */
+	if (resp->status == 0) {
+		*p++ = resp->verf[0];
+		*p++ = resp->verf[1];
+	}
+	return xdr_ressize_check(rqstp, p);
+}
+
+/*
+ * XDR release functions
+ */
+void
+nfs3svc_release_fhandle(struct svc_rqst *rqstp)
+{
+	struct nfsd3_attrstat *resp = rqstp->rq_resp;
+
+	fh_put(&resp->fh);
+}
+
+void
+nfs3svc_release_fhandle2(struct svc_rqst *rqstp)
+{
+	struct nfsd3_fhandle_pair *resp = rqstp->rq_resp;
+
+	fh_put(&resp->fh1);
+	fh_put(&resp->fh2);
+}
diff --git a/fs/nfsd/nfs4acl.c b/fs/nfsd/nfs4acl.c
new file mode 100644
index 000000000..71292a0d6
--- /dev/null
+++ b/fs/nfsd/nfs4acl.c
@@ -0,0 +1,884 @@
+/*
+ *  Common NFSv4 ACL handling code.
+ *
+ *  Copyright (c) 2002, 2003 The Regents of the University of Michigan.
+ *  All rights reserved.
+ *
+ *  Marius Aamodt Eriksen <marius@umich.edu>
+ *  Jeff Sedlak <jsedlak@umich.edu>
+ *  J. Bruce Fields <bfields@umich.edu>
+ *
+ *  Redistribution and use in source and binary forms, with or without
+ *  modification, are permitted provided that the following conditions
+ *  are met:
+ *
+ *  1. Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *  2. Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *  3. Neither the name of the University nor the names of its
+ *     contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+ *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <linux/fs.h>
+#include <linux/slab.h>
+#include <linux/posix_acl.h>
+
+#include "nfsfh.h"
+#include "nfsd.h"
+#include "acl.h"
+#include "vfs.h"
+
+#define NFS4_ACL_TYPE_DEFAULT	0x01
+#define NFS4_ACL_DIR		0x02
+#define NFS4_ACL_OWNER		0x04
+
+/* mode bit translations: */
+#define NFS4_READ_MODE (NFS4_ACE_READ_DATA)
+#define NFS4_WRITE_MODE (NFS4_ACE_WRITE_DATA | NFS4_ACE_APPEND_DATA)
+#define NFS4_EXECUTE_MODE NFS4_ACE_EXECUTE
+#define NFS4_ANYONE_MODE (NFS4_ACE_READ_ATTRIBUTES | NFS4_ACE_READ_ACL | NFS4_ACE_SYNCHRONIZE)
+#define NFS4_OWNER_MODE (NFS4_ACE_WRITE_ATTRIBUTES | NFS4_ACE_WRITE_ACL)
+
+/* flags used to simulate posix default ACLs */
+#define NFS4_INHERITANCE_FLAGS (NFS4_ACE_FILE_INHERIT_ACE \
+		| NFS4_ACE_DIRECTORY_INHERIT_ACE)
+
+#define NFS4_SUPPORTED_FLAGS (NFS4_INHERITANCE_FLAGS \
+		| NFS4_ACE_INHERIT_ONLY_ACE \
+		| NFS4_ACE_IDENTIFIER_GROUP)
+
+static u32
+mask_from_posix(unsigned short perm, unsigned int flags)
+{
+	int mask = NFS4_ANYONE_MODE;
+
+	if (flags & NFS4_ACL_OWNER)
+		mask |= NFS4_OWNER_MODE;
+	if (perm & ACL_READ)
+		mask |= NFS4_READ_MODE;
+	if (perm & ACL_WRITE)
+		mask |= NFS4_WRITE_MODE;
+	if ((perm & ACL_WRITE) && (flags & NFS4_ACL_DIR))
+		mask |= NFS4_ACE_DELETE_CHILD;
+	if (perm & ACL_EXECUTE)
+		mask |= NFS4_EXECUTE_MODE;
+	return mask;
+}
+
+static u32
+deny_mask_from_posix(unsigned short perm, u32 flags)
+{
+	u32 mask = 0;
+
+	if (perm & ACL_READ)
+		mask |= NFS4_READ_MODE;
+	if (perm & ACL_WRITE)
+		mask |= NFS4_WRITE_MODE;
+	if ((perm & ACL_WRITE) && (flags & NFS4_ACL_DIR))
+		mask |= NFS4_ACE_DELETE_CHILD;
+	if (perm & ACL_EXECUTE)
+		mask |= NFS4_EXECUTE_MODE;
+	return mask;
+}
+
+/* XXX: modify functions to return NFS errors; they're only ever
+ * used by nfs code, after all.... */
+
+/* We only map from NFSv4 to POSIX ACLs when setting ACLs, when we err on the
+ * side of being more restrictive, so the mode bit mapping below is
+ * pessimistic.  An optimistic version would be needed to handle DENY's,
+ * but we expect to coalesce all ALLOWs and DENYs before mapping to mode
+ * bits. */
+
+static void
+low_mode_from_nfs4(u32 perm, unsigned short *mode, unsigned int flags)
+{
+	u32 write_mode = NFS4_WRITE_MODE;
+
+	if (flags & NFS4_ACL_DIR)
+		write_mode |= NFS4_ACE_DELETE_CHILD;
+	*mode = 0;
+	if ((perm & NFS4_READ_MODE) == NFS4_READ_MODE)
+		*mode |= ACL_READ;
+	if ((perm & write_mode) == write_mode)
+		*mode |= ACL_WRITE;
+	if ((perm & NFS4_EXECUTE_MODE) == NFS4_EXECUTE_MODE)
+		*mode |= ACL_EXECUTE;
+}
+
+static short ace2type(struct nfs4_ace *);
+static void _posix_to_nfsv4_one(struct posix_acl *, struct nfs4_acl *,
+				unsigned int);
+
+int
+nfsd4_get_nfs4_acl(struct svc_rqst *rqstp, struct dentry *dentry,
+		struct nfs4_acl **acl)
+{
+	struct inode *inode = d_inode(dentry);
+	int error = 0;
+	struct posix_acl *pacl = NULL, *dpacl = NULL;
+	unsigned int flags = 0;
+	int size = 0;
+
+	pacl = get_acl(inode, ACL_TYPE_ACCESS);
+	if (!pacl)
+		pacl = posix_acl_from_mode(inode->i_mode, GFP_KERNEL);
+
+	if (IS_ERR(pacl))
+		return PTR_ERR(pacl);
+
+	/* allocate for worst case: one (deny, allow) pair each: */
+	size += 2 * pacl->a_count;
+
+	if (S_ISDIR(inode->i_mode)) {
+		flags = NFS4_ACL_DIR;
+		dpacl = get_acl(inode, ACL_TYPE_DEFAULT);
+		if (IS_ERR(dpacl)) {
+			error = PTR_ERR(dpacl);
+			goto rel_pacl;
+		}
+
+		if (dpacl)
+			size += 2 * dpacl->a_count;
+	}
+
+	*acl = kmalloc(nfs4_acl_bytes(size), GFP_KERNEL);
+	if (*acl == NULL) {
+		error = -ENOMEM;
+		goto out;
+	}
+	(*acl)->naces = 0;
+
+	_posix_to_nfsv4_one(pacl, *acl, flags & ~NFS4_ACL_TYPE_DEFAULT);
+
+	if (dpacl)
+		_posix_to_nfsv4_one(dpacl, *acl, flags | NFS4_ACL_TYPE_DEFAULT);
+
+out:
+	posix_acl_release(dpacl);
+rel_pacl:
+	posix_acl_release(pacl);
+	return error;
+}
+
+struct posix_acl_summary {
+	unsigned short owner;
+	unsigned short users;
+	unsigned short group;
+	unsigned short groups;
+	unsigned short other;
+	unsigned short mask;
+};
+
+static void
+summarize_posix_acl(struct posix_acl *acl, struct posix_acl_summary *pas)
+{
+	struct posix_acl_entry *pa, *pe;
+
+	/*
+	 * Only pas.users and pas.groups need initialization; previous
+	 * posix_acl_valid() calls ensure that the other fields will be
+	 * initialized in the following loop.  But, just to placate gcc:
+	 */
+	memset(pas, 0, sizeof(*pas));
+	pas->mask = 07;
+
+	pe = acl->a_entries + acl->a_count;
+
+	FOREACH_ACL_ENTRY(pa, acl, pe) {
+		switch (pa->e_tag) {
+			case ACL_USER_OBJ:
+				pas->owner = pa->e_perm;
+				break;
+			case ACL_GROUP_OBJ:
+				pas->group = pa->e_perm;
+				break;
+			case ACL_USER:
+				pas->users |= pa->e_perm;
+				break;
+			case ACL_GROUP:
+				pas->groups |= pa->e_perm;
+				break;
+			case ACL_OTHER:
+				pas->other = pa->e_perm;
+				break;
+			case ACL_MASK:
+				pas->mask = pa->e_perm;
+				break;
+		}
+	}
+	/* We'll only care about effective permissions: */
+	pas->users &= pas->mask;
+	pas->group &= pas->mask;
+	pas->groups &= pas->mask;
+}
+
+/* We assume the acl has been verified with posix_acl_valid. */
+static void
+_posix_to_nfsv4_one(struct posix_acl *pacl, struct nfs4_acl *acl,
+						unsigned int flags)
+{
+	struct posix_acl_entry *pa, *group_owner_entry;
+	struct nfs4_ace *ace;
+	struct posix_acl_summary pas;
+	unsigned short deny;
+	int eflag = ((flags & NFS4_ACL_TYPE_DEFAULT) ?
+		NFS4_INHERITANCE_FLAGS | NFS4_ACE_INHERIT_ONLY_ACE : 0);
+
+	BUG_ON(pacl->a_count < 3);
+	summarize_posix_acl(pacl, &pas);
+
+	pa = pacl->a_entries;
+	ace = acl->aces + acl->naces;
+
+	/* We could deny everything not granted by the owner: */
+	deny = ~pas.owner;
+	/*
+	 * but it is equivalent (and simpler) to deny only what is not
+	 * granted by later entries:
+	 */
+	deny &= pas.users | pas.group | pas.groups | pas.other;
+	if (deny) {
+		ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE;
+		ace->flag = eflag;
+		ace->access_mask = deny_mask_from_posix(deny, flags);
+		ace->whotype = NFS4_ACL_WHO_OWNER;
+		ace++;
+		acl->naces++;
+	}
+
+	ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE;
+	ace->flag = eflag;
+	ace->access_mask = mask_from_posix(pa->e_perm, flags | NFS4_ACL_OWNER);
+	ace->whotype = NFS4_ACL_WHO_OWNER;
+	ace++;
+	acl->naces++;
+	pa++;
+
+	while (pa->e_tag == ACL_USER) {
+		deny = ~(pa->e_perm & pas.mask);
+		deny &= pas.groups | pas.group | pas.other;
+		if (deny) {
+			ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE;
+			ace->flag = eflag;
+			ace->access_mask = deny_mask_from_posix(deny, flags);
+			ace->whotype = NFS4_ACL_WHO_NAMED;
+			ace->who_uid = pa->e_uid;
+			ace++;
+			acl->naces++;
+		}
+		ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE;
+		ace->flag = eflag;
+		ace->access_mask = mask_from_posix(pa->e_perm & pas.mask,
+						   flags);
+		ace->whotype = NFS4_ACL_WHO_NAMED;
+		ace->who_uid = pa->e_uid;
+		ace++;
+		acl->naces++;
+		pa++;
+	}
+
+	/* In the case of groups, we apply allow ACEs first, then deny ACEs,
+	 * since a user can be in more than one group.  */
+
+	/* allow ACEs */
+
+	group_owner_entry = pa;
+
+	ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE;
+	ace->flag = eflag;
+	ace->access_mask = mask_from_posix(pas.group, flags);
+	ace->whotype = NFS4_ACL_WHO_GROUP;
+	ace++;
+	acl->naces++;
+	pa++;
+
+	while (pa->e_tag == ACL_GROUP) {
+		ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE;
+		ace->flag = eflag | NFS4_ACE_IDENTIFIER_GROUP;
+		ace->access_mask = mask_from_posix(pa->e_perm & pas.mask,
+						   flags);
+		ace->whotype = NFS4_ACL_WHO_NAMED;
+		ace->who_gid = pa->e_gid;
+		ace++;
+		acl->naces++;
+		pa++;
+	}
+
+	/* deny ACEs */
+
+	pa = group_owner_entry;
+
+	deny = ~pas.group & pas.other;
+	if (deny) {
+		ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE;
+		ace->flag = eflag;
+		ace->access_mask = deny_mask_from_posix(deny, flags);
+		ace->whotype = NFS4_ACL_WHO_GROUP;
+		ace++;
+		acl->naces++;
+	}
+	pa++;
+
+	while (pa->e_tag == ACL_GROUP) {
+		deny = ~(pa->e_perm & pas.mask);
+		deny &= pas.other;
+		if (deny) {
+			ace->type = NFS4_ACE_ACCESS_DENIED_ACE_TYPE;
+			ace->flag = eflag | NFS4_ACE_IDENTIFIER_GROUP;
+			ace->access_mask = deny_mask_from_posix(deny, flags);
+			ace->whotype = NFS4_ACL_WHO_NAMED;
+			ace->who_gid = pa->e_gid;
+			ace++;
+			acl->naces++;
+		}
+		pa++;
+	}
+
+	if (pa->e_tag == ACL_MASK)
+		pa++;
+	ace->type = NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE;
+	ace->flag = eflag;
+	ace->access_mask = mask_from_posix(pa->e_perm, flags);
+	ace->whotype = NFS4_ACL_WHO_EVERYONE;
+	acl->naces++;
+}
+
+static bool
+pace_gt(struct posix_acl_entry *pace1, struct posix_acl_entry *pace2)
+{
+	if (pace1->e_tag != pace2->e_tag)
+		return pace1->e_tag > pace2->e_tag;
+	if (pace1->e_tag == ACL_USER)
+		return uid_gt(pace1->e_uid, pace2->e_uid);
+	if (pace1->e_tag == ACL_GROUP)
+		return gid_gt(pace1->e_gid, pace2->e_gid);
+	return false;
+}
+
+static void
+sort_pacl_range(struct posix_acl *pacl, int start, int end) {
+	int sorted = 0, i;
+
+	/* We just do a bubble sort; easy to do in place, and we're not
+	 * expecting acl's to be long enough to justify anything more. */
+	while (!sorted) {
+		sorted = 1;
+		for (i = start; i < end; i++) {
+			if (pace_gt(&pacl->a_entries[i],
+				    &pacl->a_entries[i+1])) {
+				sorted = 0;
+				swap(pacl->a_entries[i],
+				     pacl->a_entries[i + 1]);
+			}
+		}
+	}
+}
+
+static void
+sort_pacl(struct posix_acl *pacl)
+{
+	/* posix_acl_valid requires that users and groups be in order
+	 * by uid/gid. */
+	int i, j;
+
+	/* no users or groups */
+	if (!pacl || pacl->a_count <= 4)
+		return;
+
+	i = 1;
+	while (pacl->a_entries[i].e_tag == ACL_USER)
+		i++;
+	sort_pacl_range(pacl, 1, i-1);
+
+	BUG_ON(pacl->a_entries[i].e_tag != ACL_GROUP_OBJ);
+	j = ++i;
+	while (pacl->a_entries[j].e_tag == ACL_GROUP)
+		j++;
+	sort_pacl_range(pacl, i, j-1);
+	return;
+}
+
+/*
+ * While processing the NFSv4 ACE, this maintains bitmasks representing
+ * which permission bits have been allowed and which denied to a given
+ * entity: */
+struct posix_ace_state {
+	u32 allow;
+	u32 deny;
+};
+
+struct posix_user_ace_state {
+	union {
+		kuid_t uid;
+		kgid_t gid;
+	};
+	struct posix_ace_state perms;
+};
+
+struct posix_ace_state_array {
+	int n;
+	struct posix_user_ace_state aces[];
+};
+
+/*
+ * While processing the NFSv4 ACE, this maintains the partial permissions
+ * calculated so far: */
+
+struct posix_acl_state {
+	int empty;
+	struct posix_ace_state owner;
+	struct posix_ace_state group;
+	struct posix_ace_state other;
+	struct posix_ace_state everyone;
+	struct posix_ace_state mask; /* Deny unused in this case */
+	struct posix_ace_state_array *users;
+	struct posix_ace_state_array *groups;
+};
+
+static int
+init_state(struct posix_acl_state *state, int cnt)
+{
+	int alloc;
+
+	memset(state, 0, sizeof(struct posix_acl_state));
+	state->empty = 1;
+	/*
+	 * In the worst case, each individual acl could be for a distinct
+	 * named user or group, but we don't know which, so we allocate
+	 * enough space for either:
+	 */
+	alloc = sizeof(struct posix_ace_state_array)
+		+ cnt*sizeof(struct posix_user_ace_state);
+	state->users = kzalloc(alloc, GFP_KERNEL);
+	if (!state->users)
+		return -ENOMEM;
+	state->groups = kzalloc(alloc, GFP_KERNEL);
+	if (!state->groups) {
+		kfree(state->users);
+		return -ENOMEM;
+	}
+	return 0;
+}
+
+static void
+free_state(struct posix_acl_state *state) {
+	kfree(state->users);
+	kfree(state->groups);
+}
+
+static inline void add_to_mask(struct posix_acl_state *state, struct posix_ace_state *astate)
+{
+	state->mask.allow |= astate->allow;
+}
+
+static struct posix_acl *
+posix_state_to_acl(struct posix_acl_state *state, unsigned int flags)
+{
+	struct posix_acl_entry *pace;
+	struct posix_acl *pacl;
+	int nace;
+	int i;
+
+	/*
+	 * ACLs with no ACEs are treated differently in the inheritable
+	 * and effective cases: when there are no inheritable ACEs,
+	 * calls ->set_acl with a NULL ACL structure.
+	 */
+	if (state->empty && (flags & NFS4_ACL_TYPE_DEFAULT))
+		return NULL;
+
+	/*
+	 * When there are no effective ACEs, the following will end
+	 * up setting a 3-element effective posix ACL with all
+	 * permissions zero.
+	 */
+	if (!state->users->n && !state->groups->n)
+		nace = 3;
+	else /* Note we also include a MASK ACE in this case: */
+		nace = 4 + state->users->n + state->groups->n;
+	pacl = posix_acl_alloc(nace, GFP_KERNEL);
+	if (!pacl)
+		return ERR_PTR(-ENOMEM);
+
+	pace = pacl->a_entries;
+	pace->e_tag = ACL_USER_OBJ;
+	low_mode_from_nfs4(state->owner.allow, &pace->e_perm, flags);
+
+	for (i=0; i < state->users->n; i++) {
+		pace++;
+		pace->e_tag = ACL_USER;
+		low_mode_from_nfs4(state->users->aces[i].perms.allow,
+					&pace->e_perm, flags);
+		pace->e_uid = state->users->aces[i].uid;
+		add_to_mask(state, &state->users->aces[i].perms);
+	}
+
+	pace++;
+	pace->e_tag = ACL_GROUP_OBJ;
+	low_mode_from_nfs4(state->group.allow, &pace->e_perm, flags);
+	add_to_mask(state, &state->group);
+
+	for (i=0; i < state->groups->n; i++) {
+		pace++;
+		pace->e_tag = ACL_GROUP;
+		low_mode_from_nfs4(state->groups->aces[i].perms.allow,
+					&pace->e_perm, flags);
+		pace->e_gid = state->groups->aces[i].gid;
+		add_to_mask(state, &state->groups->aces[i].perms);
+	}
+
+	if (state->users->n || state->groups->n) {
+		pace++;
+		pace->e_tag = ACL_MASK;
+		low_mode_from_nfs4(state->mask.allow, &pace->e_perm, flags);
+	}
+
+	pace++;
+	pace->e_tag = ACL_OTHER;
+	low_mode_from_nfs4(state->other.allow, &pace->e_perm, flags);
+
+	return pacl;
+}
+
+static inline void allow_bits(struct posix_ace_state *astate, u32 mask)
+{
+	/* Allow all bits in the mask not already denied: */
+	astate->allow |= mask & ~astate->deny;
+}
+
+static inline void deny_bits(struct posix_ace_state *astate, u32 mask)
+{
+	/* Deny all bits in the mask not already allowed: */
+	astate->deny |= mask & ~astate->allow;
+}
+
+static int find_uid(struct posix_acl_state *state, kuid_t uid)
+{
+	struct posix_ace_state_array *a = state->users;
+	int i;
+
+	for (i = 0; i < a->n; i++)
+		if (uid_eq(a->aces[i].uid, uid))
+			return i;
+	/* Not found: */
+	a->n++;
+	a->aces[i].uid = uid;
+	a->aces[i].perms.allow = state->everyone.allow;
+	a->aces[i].perms.deny  = state->everyone.deny;
+
+	return i;
+}
+
+static int find_gid(struct posix_acl_state *state, kgid_t gid)
+{
+	struct posix_ace_state_array *a = state->groups;
+	int i;
+
+	for (i = 0; i < a->n; i++)
+		if (gid_eq(a->aces[i].gid, gid))
+			return i;
+	/* Not found: */
+	a->n++;
+	a->aces[i].gid = gid;
+	a->aces[i].perms.allow = state->everyone.allow;
+	a->aces[i].perms.deny  = state->everyone.deny;
+
+	return i;
+}
+
+static void deny_bits_array(struct posix_ace_state_array *a, u32 mask)
+{
+	int i;
+
+	for (i=0; i < a->n; i++)
+		deny_bits(&a->aces[i].perms, mask);
+}
+
+static void allow_bits_array(struct posix_ace_state_array *a, u32 mask)
+{
+	int i;
+
+	for (i=0; i < a->n; i++)
+		allow_bits(&a->aces[i].perms, mask);
+}
+
+static void process_one_v4_ace(struct posix_acl_state *state,
+				struct nfs4_ace *ace)
+{
+	u32 mask = ace->access_mask;
+	int i;
+
+	state->empty = 0;
+
+	switch (ace2type(ace)) {
+	case ACL_USER_OBJ:
+		if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) {
+			allow_bits(&state->owner, mask);
+		} else {
+			deny_bits(&state->owner, mask);
+		}
+		break;
+	case ACL_USER:
+		i = find_uid(state, ace->who_uid);
+		if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) {
+			allow_bits(&state->users->aces[i].perms, mask);
+		} else {
+			deny_bits(&state->users->aces[i].perms, mask);
+			mask = state->users->aces[i].perms.deny;
+			deny_bits(&state->owner, mask);
+		}
+		break;
+	case ACL_GROUP_OBJ:
+		if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) {
+			allow_bits(&state->group, mask);
+		} else {
+			deny_bits(&state->group, mask);
+			mask = state->group.deny;
+			deny_bits(&state->owner, mask);
+			deny_bits(&state->everyone, mask);
+			deny_bits_array(state->users, mask);
+			deny_bits_array(state->groups, mask);
+		}
+		break;
+	case ACL_GROUP:
+		i = find_gid(state, ace->who_gid);
+		if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) {
+			allow_bits(&state->groups->aces[i].perms, mask);
+		} else {
+			deny_bits(&state->groups->aces[i].perms, mask);
+			mask = state->groups->aces[i].perms.deny;
+			deny_bits(&state->owner, mask);
+			deny_bits(&state->group, mask);
+			deny_bits(&state->everyone, mask);
+			deny_bits_array(state->users, mask);
+			deny_bits_array(state->groups, mask);
+		}
+		break;
+	case ACL_OTHER:
+		if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) {
+			allow_bits(&state->owner, mask);
+			allow_bits(&state->group, mask);
+			allow_bits(&state->other, mask);
+			allow_bits(&state->everyone, mask);
+			allow_bits_array(state->users, mask);
+			allow_bits_array(state->groups, mask);
+		} else {
+			deny_bits(&state->owner, mask);
+			deny_bits(&state->group, mask);
+			deny_bits(&state->other, mask);
+			deny_bits(&state->everyone, mask);
+			deny_bits_array(state->users, mask);
+			deny_bits_array(state->groups, mask);
+		}
+	}
+}
+
+static int nfs4_acl_nfsv4_to_posix(struct nfs4_acl *acl,
+		struct posix_acl **pacl, struct posix_acl **dpacl,
+		unsigned int flags)
+{
+	struct posix_acl_state effective_acl_state, default_acl_state;
+	struct nfs4_ace *ace;
+	int ret;
+
+	ret = init_state(&effective_acl_state, acl->naces);
+	if (ret)
+		return ret;
+	ret = init_state(&default_acl_state, acl->naces);
+	if (ret)
+		goto out_estate;
+	ret = -EINVAL;
+	for (ace = acl->aces; ace < acl->aces + acl->naces; ace++) {
+		if (ace->type != NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE &&
+		    ace->type != NFS4_ACE_ACCESS_DENIED_ACE_TYPE)
+			goto out_dstate;
+		if (ace->flag & ~NFS4_SUPPORTED_FLAGS)
+			goto out_dstate;
+		if ((ace->flag & NFS4_INHERITANCE_FLAGS) == 0) {
+			process_one_v4_ace(&effective_acl_state, ace);
+			continue;
+		}
+		if (!(flags & NFS4_ACL_DIR))
+			goto out_dstate;
+		/*
+		 * Note that when only one of FILE_INHERIT or DIRECTORY_INHERIT
+		 * is set, we're effectively turning on the other.  That's OK,
+		 * according to rfc 3530.
+		 */
+		process_one_v4_ace(&default_acl_state, ace);
+
+		if (!(ace->flag & NFS4_ACE_INHERIT_ONLY_ACE))
+			process_one_v4_ace(&effective_acl_state, ace);
+	}
+	*pacl = posix_state_to_acl(&effective_acl_state, flags);
+	if (IS_ERR(*pacl)) {
+		ret = PTR_ERR(*pacl);
+		*pacl = NULL;
+		goto out_dstate;
+	}
+	*dpacl = posix_state_to_acl(&default_acl_state,
+						flags | NFS4_ACL_TYPE_DEFAULT);
+	if (IS_ERR(*dpacl)) {
+		ret = PTR_ERR(*dpacl);
+		*dpacl = NULL;
+		posix_acl_release(*pacl);
+		*pacl = NULL;
+		goto out_dstate;
+	}
+	sort_pacl(*pacl);
+	sort_pacl(*dpacl);
+	ret = 0;
+out_dstate:
+	free_state(&default_acl_state);
+out_estate:
+	free_state(&effective_acl_state);
+	return ret;
+}
+
+__be32
+nfsd4_set_nfs4_acl(struct svc_rqst *rqstp, struct svc_fh *fhp,
+		struct nfs4_acl *acl)
+{
+	__be32 error;
+	int host_error;
+	struct dentry *dentry;
+	struct inode *inode;
+	struct posix_acl *pacl = NULL, *dpacl = NULL;
+	unsigned int flags = 0;
+
+	/* Get inode */
+	error = fh_verify(rqstp, fhp, 0, NFSD_MAY_SATTR);
+	if (error)
+		return error;
+
+	dentry = fhp->fh_dentry;
+	inode = d_inode(dentry);
+
+	if (S_ISDIR(inode->i_mode))
+		flags = NFS4_ACL_DIR;
+
+	host_error = nfs4_acl_nfsv4_to_posix(acl, &pacl, &dpacl, flags);
+	if (host_error == -EINVAL)
+		return nfserr_attrnotsupp;
+	if (host_error < 0)
+		goto out_nfserr;
+
+	fh_lock(fhp);
+
+	host_error = set_posix_acl(inode, ACL_TYPE_ACCESS, pacl);
+	if (host_error < 0)
+		goto out_drop_lock;
+
+	if (S_ISDIR(inode->i_mode)) {
+		host_error = set_posix_acl(inode, ACL_TYPE_DEFAULT, dpacl);
+	}
+
+out_drop_lock:
+	fh_unlock(fhp);
+
+	posix_acl_release(pacl);
+	posix_acl_release(dpacl);
+out_nfserr:
+	if (host_error == -EOPNOTSUPP)
+		return nfserr_attrnotsupp;
+	else
+		return nfserrno(host_error);
+}
+
+
+static short
+ace2type(struct nfs4_ace *ace)
+{
+	switch (ace->whotype) {
+		case NFS4_ACL_WHO_NAMED:
+			return (ace->flag & NFS4_ACE_IDENTIFIER_GROUP ?
+					ACL_GROUP : ACL_USER);
+		case NFS4_ACL_WHO_OWNER:
+			return ACL_USER_OBJ;
+		case NFS4_ACL_WHO_GROUP:
+			return ACL_GROUP_OBJ;
+		case NFS4_ACL_WHO_EVERYONE:
+			return ACL_OTHER;
+	}
+	BUG();
+	return -1;
+}
+
+/*
+ * return the size of the struct nfs4_acl required to represent an acl
+ * with @entries entries.
+ */
+int nfs4_acl_bytes(int entries)
+{
+	return sizeof(struct nfs4_acl) + entries * sizeof(struct nfs4_ace);
+}
+
+static struct {
+	char *string;
+	int   stringlen;
+	int type;
+} s2t_map[] = {
+	{
+		.string    = "OWNER@",
+		.stringlen = sizeof("OWNER@") - 1,
+		.type      = NFS4_ACL_WHO_OWNER,
+	},
+	{
+		.string    = "GROUP@",
+		.stringlen = sizeof("GROUP@") - 1,
+		.type      = NFS4_ACL_WHO_GROUP,
+	},
+	{
+		.string    = "EVERYONE@",
+		.stringlen = sizeof("EVERYONE@") - 1,
+		.type      = NFS4_ACL_WHO_EVERYONE,
+	},
+};
+
+int
+nfs4_acl_get_whotype(char *p, u32 len)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(s2t_map); i++) {
+		if (s2t_map[i].stringlen == len &&
+				0 == memcmp(s2t_map[i].string, p, len))
+			return s2t_map[i].type;
+	}
+	return NFS4_ACL_WHO_NAMED;
+}
+
+__be32 nfs4_acl_write_who(struct xdr_stream *xdr, int who)
+{
+	__be32 *p;
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(s2t_map); i++) {
+		if (s2t_map[i].type != who)
+			continue;
+		p = xdr_reserve_space(xdr, s2t_map[i].stringlen + 4);
+		if (!p)
+			return nfserr_resource;
+		p = xdr_encode_opaque(p, s2t_map[i].string,
+					s2t_map[i].stringlen);
+		return 0;
+	}
+	WARN_ON_ONCE(1);
+	return nfserr_serverfault;
+}
diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c
new file mode 100644
index 000000000..f5b7ad084
--- /dev/null
+++ b/fs/nfsd/nfs4callback.c
@@ -0,0 +1,1381 @@
+/*
+ *  Copyright (c) 2001 The Regents of the University of Michigan.
+ *  All rights reserved.
+ *
+ *  Kendrick Smith <kmsmith@umich.edu>
+ *  Andy Adamson <andros@umich.edu>
+ *
+ *  Redistribution and use in source and binary forms, with or without
+ *  modification, are permitted provided that the following conditions
+ *  are met:
+ *
+ *  1. Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *  2. Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *  3. Neither the name of the University nor the names of its
+ *     contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+ *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <linux/sunrpc/clnt.h>
+#include <linux/sunrpc/xprt.h>
+#include <linux/sunrpc/svc_xprt.h>
+#include <linux/slab.h>
+#include "nfsd.h"
+#include "state.h"
+#include "netns.h"
+#include "trace.h"
+#include "xdr4cb.h"
+#include "xdr4.h"
+
+#define NFSDDBG_FACILITY                NFSDDBG_PROC
+
+static void nfsd4_mark_cb_fault(struct nfs4_client *, int reason);
+
+#define NFSPROC4_CB_NULL 0
+#define NFSPROC4_CB_COMPOUND 1
+
+/* Index of predefined Linux callback client operations */
+
+struct nfs4_cb_compound_hdr {
+	/* args */
+	u32		ident;	/* minorversion 0 only */
+	u32		nops;
+	__be32		*nops_p;
+	u32		minorversion;
+	/* res */
+	int		status;
+};
+
+static __be32 *xdr_encode_empty_array(__be32 *p)
+{
+	*p++ = xdr_zero;
+	return p;
+}
+
+/*
+ * Encode/decode NFSv4 CB basic data types
+ *
+ * Basic NFSv4 callback data types are defined in section 15 of RFC
+ * 3530: "Network File System (NFS) version 4 Protocol" and section
+ * 20 of RFC 5661: "Network File System (NFS) Version 4 Minor Version
+ * 1 Protocol"
+ */
+
+/*
+ *	nfs_cb_opnum4
+ *
+ *	enum nfs_cb_opnum4 {
+ *		OP_CB_GETATTR		= 3,
+ *		  ...
+ *	};
+ */
+enum nfs_cb_opnum4 {
+	OP_CB_GETATTR			= 3,
+	OP_CB_RECALL			= 4,
+	OP_CB_LAYOUTRECALL		= 5,
+	OP_CB_NOTIFY			= 6,
+	OP_CB_PUSH_DELEG		= 7,
+	OP_CB_RECALL_ANY		= 8,
+	OP_CB_RECALLABLE_OBJ_AVAIL	= 9,
+	OP_CB_RECALL_SLOT		= 10,
+	OP_CB_SEQUENCE			= 11,
+	OP_CB_WANTS_CANCELLED		= 12,
+	OP_CB_NOTIFY_LOCK		= 13,
+	OP_CB_NOTIFY_DEVICEID		= 14,
+	OP_CB_OFFLOAD			= 15,
+	OP_CB_ILLEGAL			= 10044
+};
+
+static void encode_nfs_cb_opnum4(struct xdr_stream *xdr, enum nfs_cb_opnum4 op)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 4);
+	*p = cpu_to_be32(op);
+}
+
+/*
+ * nfs_fh4
+ *
+ *	typedef opaque nfs_fh4<NFS4_FHSIZE>;
+ */
+static void encode_nfs_fh4(struct xdr_stream *xdr, const struct knfsd_fh *fh)
+{
+	u32 length = fh->fh_size;
+	__be32 *p;
+
+	BUG_ON(length > NFS4_FHSIZE);
+	p = xdr_reserve_space(xdr, 4 + length);
+	xdr_encode_opaque(p, &fh->fh_base, length);
+}
+
+/*
+ * stateid4
+ *
+ *	struct stateid4 {
+ *		uint32_t	seqid;
+ *		opaque		other[12];
+ *	};
+ */
+static void encode_stateid4(struct xdr_stream *xdr, const stateid_t *sid)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, NFS4_STATEID_SIZE);
+	*p++ = cpu_to_be32(sid->si_generation);
+	xdr_encode_opaque_fixed(p, &sid->si_opaque, NFS4_STATEID_OTHER_SIZE);
+}
+
+/*
+ * sessionid4
+ *
+ *	typedef opaque sessionid4[NFS4_SESSIONID_SIZE];
+ */
+static void encode_sessionid4(struct xdr_stream *xdr,
+			      const struct nfsd4_session *session)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN);
+	xdr_encode_opaque_fixed(p, session->se_sessionid.data,
+					NFS4_MAX_SESSIONID_LEN);
+}
+
+/*
+ * nfsstat4
+ */
+static const struct {
+	int stat;
+	int errno;
+} nfs_cb_errtbl[] = {
+	{ NFS4_OK,		0		},
+	{ NFS4ERR_PERM,		-EPERM		},
+	{ NFS4ERR_NOENT,	-ENOENT		},
+	{ NFS4ERR_IO,		-EIO		},
+	{ NFS4ERR_NXIO,		-ENXIO		},
+	{ NFS4ERR_ACCESS,	-EACCES		},
+	{ NFS4ERR_EXIST,	-EEXIST		},
+	{ NFS4ERR_XDEV,		-EXDEV		},
+	{ NFS4ERR_NOTDIR,	-ENOTDIR	},
+	{ NFS4ERR_ISDIR,	-EISDIR		},
+	{ NFS4ERR_INVAL,	-EINVAL		},
+	{ NFS4ERR_FBIG,		-EFBIG		},
+	{ NFS4ERR_NOSPC,	-ENOSPC		},
+	{ NFS4ERR_ROFS,		-EROFS		},
+	{ NFS4ERR_MLINK,	-EMLINK		},
+	{ NFS4ERR_NAMETOOLONG,	-ENAMETOOLONG	},
+	{ NFS4ERR_NOTEMPTY,	-ENOTEMPTY	},
+	{ NFS4ERR_DQUOT,	-EDQUOT		},
+	{ NFS4ERR_STALE,	-ESTALE		},
+	{ NFS4ERR_BADHANDLE,	-EBADHANDLE	},
+	{ NFS4ERR_BAD_COOKIE,	-EBADCOOKIE	},
+	{ NFS4ERR_NOTSUPP,	-ENOTSUPP	},
+	{ NFS4ERR_TOOSMALL,	-ETOOSMALL	},
+	{ NFS4ERR_SERVERFAULT,	-ESERVERFAULT	},
+	{ NFS4ERR_BADTYPE,	-EBADTYPE	},
+	{ NFS4ERR_LOCKED,	-EAGAIN		},
+	{ NFS4ERR_RESOURCE,	-EREMOTEIO	},
+	{ NFS4ERR_SYMLINK,	-ELOOP		},
+	{ NFS4ERR_OP_ILLEGAL,	-EOPNOTSUPP	},
+	{ NFS4ERR_DEADLOCK,	-EDEADLK	},
+	{ -1,			-EIO		}
+};
+
+/*
+ * If we cannot translate the error, the recovery routines should
+ * handle it.
+ *
+ * Note: remaining NFSv4 error codes have values > 10000, so should
+ * not conflict with native Linux error codes.
+ */
+static int nfs_cb_stat_to_errno(int status)
+{
+	int i;
+
+	for (i = 0; nfs_cb_errtbl[i].stat != -1; i++) {
+		if (nfs_cb_errtbl[i].stat == status)
+			return nfs_cb_errtbl[i].errno;
+	}
+
+	dprintk("NFSD: Unrecognized NFS CB status value: %u\n", status);
+	return -status;
+}
+
+static int decode_cb_op_status(struct xdr_stream *xdr,
+			       enum nfs_cb_opnum4 expected, int *status)
+{
+	__be32 *p;
+	u32 op;
+
+	p = xdr_inline_decode(xdr, 4 + 4);
+	if (unlikely(p == NULL))
+		goto out_overflow;
+	op = be32_to_cpup(p++);
+	if (unlikely(op != expected))
+		goto out_unexpected;
+	*status = nfs_cb_stat_to_errno(be32_to_cpup(p));
+	return 0;
+out_overflow:
+	return -EIO;
+out_unexpected:
+	dprintk("NFSD: Callback server returned operation %d but "
+		"we issued a request for %d\n", op, expected);
+	return -EIO;
+}
+
+/*
+ * CB_COMPOUND4args
+ *
+ *	struct CB_COMPOUND4args {
+ *		utf8str_cs	tag;
+ *		uint32_t	minorversion;
+ *		uint32_t	callback_ident;
+ *		nfs_cb_argop4	argarray<>;
+ *	};
+*/
+static void encode_cb_compound4args(struct xdr_stream *xdr,
+				    struct nfs4_cb_compound_hdr *hdr)
+{
+	__be32 * p;
+
+	p = xdr_reserve_space(xdr, 4 + 4 + 4 + 4);
+	p = xdr_encode_empty_array(p);		/* empty tag */
+	*p++ = cpu_to_be32(hdr->minorversion);
+	*p++ = cpu_to_be32(hdr->ident);
+
+	hdr->nops_p = p;
+	*p = cpu_to_be32(hdr->nops);		/* argarray element count */
+}
+
+/*
+ * Update argarray element count
+ */
+static void encode_cb_nops(struct nfs4_cb_compound_hdr *hdr)
+{
+	BUG_ON(hdr->nops > NFS4_MAX_BACK_CHANNEL_OPS);
+	*hdr->nops_p = cpu_to_be32(hdr->nops);
+}
+
+/*
+ * CB_COMPOUND4res
+ *
+ *	struct CB_COMPOUND4res {
+ *		nfsstat4	status;
+ *		utf8str_cs	tag;
+ *		nfs_cb_resop4	resarray<>;
+ *	};
+ */
+static int decode_cb_compound4res(struct xdr_stream *xdr,
+				  struct nfs4_cb_compound_hdr *hdr)
+{
+	u32 length;
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, 4 + 4);
+	if (unlikely(p == NULL))
+		goto out_overflow;
+	hdr->status = be32_to_cpup(p++);
+	/* Ignore the tag */
+	length = be32_to_cpup(p++);
+	p = xdr_inline_decode(xdr, length + 4);
+	if (unlikely(p == NULL))
+		goto out_overflow;
+	p += XDR_QUADLEN(length);
+	hdr->nops = be32_to_cpup(p);
+	return 0;
+out_overflow:
+	return -EIO;
+}
+
+/*
+ * CB_RECALL4args
+ *
+ *	struct CB_RECALL4args {
+ *		stateid4	stateid;
+ *		bool		truncate;
+ *		nfs_fh4		fh;
+ *	};
+ */
+static void encode_cb_recall4args(struct xdr_stream *xdr,
+				  const struct nfs4_delegation *dp,
+				  struct nfs4_cb_compound_hdr *hdr)
+{
+	__be32 *p;
+
+	encode_nfs_cb_opnum4(xdr, OP_CB_RECALL);
+	encode_stateid4(xdr, &dp->dl_stid.sc_stateid);
+
+	p = xdr_reserve_space(xdr, 4);
+	*p++ = xdr_zero;			/* truncate */
+
+	encode_nfs_fh4(xdr, &dp->dl_stid.sc_file->fi_fhandle);
+
+	hdr->nops++;
+}
+
+/*
+ * CB_SEQUENCE4args
+ *
+ *	struct CB_SEQUENCE4args {
+ *		sessionid4		csa_sessionid;
+ *		sequenceid4		csa_sequenceid;
+ *		slotid4			csa_slotid;
+ *		slotid4			csa_highest_slotid;
+ *		bool			csa_cachethis;
+ *		referring_call_list4	csa_referring_call_lists<>;
+ *	};
+ */
+static void encode_cb_sequence4args(struct xdr_stream *xdr,
+				    const struct nfsd4_callback *cb,
+				    struct nfs4_cb_compound_hdr *hdr)
+{
+	struct nfsd4_session *session = cb->cb_clp->cl_cb_session;
+	__be32 *p;
+
+	if (hdr->minorversion == 0)
+		return;
+
+	encode_nfs_cb_opnum4(xdr, OP_CB_SEQUENCE);
+	encode_sessionid4(xdr, session);
+
+	p = xdr_reserve_space(xdr, 4 + 4 + 4 + 4 + 4);
+	*p++ = cpu_to_be32(session->se_cb_seq_nr);	/* csa_sequenceid */
+	*p++ = xdr_zero;			/* csa_slotid */
+	*p++ = xdr_zero;			/* csa_highest_slotid */
+	*p++ = xdr_zero;			/* csa_cachethis */
+	xdr_encode_empty_array(p);		/* csa_referring_call_lists */
+
+	hdr->nops++;
+}
+
+/*
+ * CB_SEQUENCE4resok
+ *
+ *	struct CB_SEQUENCE4resok {
+ *		sessionid4	csr_sessionid;
+ *		sequenceid4	csr_sequenceid;
+ *		slotid4		csr_slotid;
+ *		slotid4		csr_highest_slotid;
+ *		slotid4		csr_target_highest_slotid;
+ *	};
+ *
+ *	union CB_SEQUENCE4res switch (nfsstat4 csr_status) {
+ *	case NFS4_OK:
+ *		CB_SEQUENCE4resok	csr_resok4;
+ *	default:
+ *		void;
+ *	};
+ *
+ * Our current back channel implmentation supports a single backchannel
+ * with a single slot.
+ */
+static int decode_cb_sequence4resok(struct xdr_stream *xdr,
+				    struct nfsd4_callback *cb)
+{
+	struct nfsd4_session *session = cb->cb_clp->cl_cb_session;
+	int status = -ESERVERFAULT;
+	__be32 *p;
+	u32 dummy;
+
+	/*
+	 * If the server returns different values for sessionID, slotID or
+	 * sequence number, the server is looney tunes.
+	 */
+	p = xdr_inline_decode(xdr, NFS4_MAX_SESSIONID_LEN + 4 + 4 + 4 + 4);
+	if (unlikely(p == NULL))
+		goto out_overflow;
+
+	if (memcmp(p, session->se_sessionid.data, NFS4_MAX_SESSIONID_LEN)) {
+		dprintk("NFS: %s Invalid session id\n", __func__);
+		goto out;
+	}
+	p += XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN);
+
+	dummy = be32_to_cpup(p++);
+	if (dummy != session->se_cb_seq_nr) {
+		dprintk("NFS: %s Invalid sequence number\n", __func__);
+		goto out;
+	}
+
+	dummy = be32_to_cpup(p++);
+	if (dummy != 0) {
+		dprintk("NFS: %s Invalid slotid\n", __func__);
+		goto out;
+	}
+
+	/*
+	 * FIXME: process highest slotid and target highest slotid
+	 */
+	status = 0;
+out:
+	cb->cb_seq_status = status;
+	return status;
+out_overflow:
+	status = -EIO;
+	goto out;
+}
+
+static int decode_cb_sequence4res(struct xdr_stream *xdr,
+				  struct nfsd4_callback *cb)
+{
+	int status;
+
+	if (cb->cb_clp->cl_minorversion == 0)
+		return 0;
+
+	status = decode_cb_op_status(xdr, OP_CB_SEQUENCE, &cb->cb_seq_status);
+	if (unlikely(status || cb->cb_seq_status))
+		return status;
+
+	return decode_cb_sequence4resok(xdr, cb);
+}
+
+/*
+ * NFSv4.0 and NFSv4.1 XDR encode functions
+ *
+ * NFSv4.0 callback argument types are defined in section 15 of RFC
+ * 3530: "Network File System (NFS) version 4 Protocol" and section 20
+ * of RFC 5661:  "Network File System (NFS) Version 4 Minor Version 1
+ * Protocol".
+ */
+
+/*
+ * NB: Without this zero space reservation, callbacks over krb5p fail
+ */
+static void nfs4_xdr_enc_cb_null(struct rpc_rqst *req, struct xdr_stream *xdr,
+				 const void *__unused)
+{
+	xdr_reserve_space(xdr, 0);
+}
+
+/*
+ * 20.2. Operation 4: CB_RECALL - Recall a Delegation
+ */
+static void nfs4_xdr_enc_cb_recall(struct rpc_rqst *req, struct xdr_stream *xdr,
+				   const void *data)
+{
+	const struct nfsd4_callback *cb = data;
+	const struct nfs4_delegation *dp = cb_to_delegation(cb);
+	struct nfs4_cb_compound_hdr hdr = {
+		.ident = cb->cb_clp->cl_cb_ident,
+		.minorversion = cb->cb_clp->cl_minorversion,
+	};
+
+	encode_cb_compound4args(xdr, &hdr);
+	encode_cb_sequence4args(xdr, cb, &hdr);
+	encode_cb_recall4args(xdr, dp, &hdr);
+	encode_cb_nops(&hdr);
+}
+
+
+/*
+ * NFSv4.0 and NFSv4.1 XDR decode functions
+ *
+ * NFSv4.0 callback result types are defined in section 15 of RFC
+ * 3530: "Network File System (NFS) version 4 Protocol" and section 20
+ * of RFC 5661:  "Network File System (NFS) Version 4 Minor Version 1
+ * Protocol".
+ */
+
+static int nfs4_xdr_dec_cb_null(struct rpc_rqst *req, struct xdr_stream *xdr,
+				void *__unused)
+{
+	return 0;
+}
+
+/*
+ * 20.2. Operation 4: CB_RECALL - Recall a Delegation
+ */
+static int nfs4_xdr_dec_cb_recall(struct rpc_rqst *rqstp,
+				  struct xdr_stream *xdr,
+				  void *data)
+{
+	struct nfsd4_callback *cb = data;
+	struct nfs4_cb_compound_hdr hdr;
+	int status;
+
+	status = decode_cb_compound4res(xdr, &hdr);
+	if (unlikely(status))
+		return status;
+
+	status = decode_cb_sequence4res(xdr, cb);
+	if (unlikely(status || cb->cb_seq_status))
+		return status;
+
+	return decode_cb_op_status(xdr, OP_CB_RECALL, &cb->cb_status);
+}
+
+#ifdef CONFIG_NFSD_PNFS
+/*
+ * CB_LAYOUTRECALL4args
+ *
+ *	struct layoutrecall_file4 {
+ *		nfs_fh4         lor_fh;
+ *		offset4         lor_offset;
+ *		length4         lor_length;
+ *		stateid4        lor_stateid;
+ *	};
+ *
+ *	union layoutrecall4 switch(layoutrecall_type4 lor_recalltype) {
+ *	case LAYOUTRECALL4_FILE:
+ *		layoutrecall_file4 lor_layout;
+ *	case LAYOUTRECALL4_FSID:
+ *		fsid4              lor_fsid;
+ *	case LAYOUTRECALL4_ALL:
+ *		void;
+ *	};
+ *
+ *	struct CB_LAYOUTRECALL4args {
+ *		layouttype4             clora_type;
+ *		layoutiomode4           clora_iomode;
+ *		bool                    clora_changed;
+ *		layoutrecall4           clora_recall;
+ *	};
+ */
+static void encode_cb_layout4args(struct xdr_stream *xdr,
+				  const struct nfs4_layout_stateid *ls,
+				  struct nfs4_cb_compound_hdr *hdr)
+{
+	__be32 *p;
+
+	BUG_ON(hdr->minorversion == 0);
+
+	p = xdr_reserve_space(xdr, 5 * 4);
+	*p++ = cpu_to_be32(OP_CB_LAYOUTRECALL);
+	*p++ = cpu_to_be32(ls->ls_layout_type);
+	*p++ = cpu_to_be32(IOMODE_ANY);
+	*p++ = cpu_to_be32(1);
+	*p = cpu_to_be32(RETURN_FILE);
+
+	encode_nfs_fh4(xdr, &ls->ls_stid.sc_file->fi_fhandle);
+
+	p = xdr_reserve_space(xdr, 2 * 8);
+	p = xdr_encode_hyper(p, 0);
+	xdr_encode_hyper(p, NFS4_MAX_UINT64);
+
+	encode_stateid4(xdr, &ls->ls_recall_sid);
+
+	hdr->nops++;
+}
+
+static void nfs4_xdr_enc_cb_layout(struct rpc_rqst *req,
+				   struct xdr_stream *xdr,
+				   const void *data)
+{
+	const struct nfsd4_callback *cb = data;
+	const struct nfs4_layout_stateid *ls =
+		container_of(cb, struct nfs4_layout_stateid, ls_recall);
+	struct nfs4_cb_compound_hdr hdr = {
+		.ident = 0,
+		.minorversion = cb->cb_clp->cl_minorversion,
+	};
+
+	encode_cb_compound4args(xdr, &hdr);
+	encode_cb_sequence4args(xdr, cb, &hdr);
+	encode_cb_layout4args(xdr, ls, &hdr);
+	encode_cb_nops(&hdr);
+}
+
+static int nfs4_xdr_dec_cb_layout(struct rpc_rqst *rqstp,
+				  struct xdr_stream *xdr,
+				  void *data)
+{
+	struct nfsd4_callback *cb = data;
+	struct nfs4_cb_compound_hdr hdr;
+	int status;
+
+	status = decode_cb_compound4res(xdr, &hdr);
+	if (unlikely(status))
+		return status;
+
+	status = decode_cb_sequence4res(xdr, cb);
+	if (unlikely(status || cb->cb_seq_status))
+		return status;
+
+	return decode_cb_op_status(xdr, OP_CB_LAYOUTRECALL, &cb->cb_status);
+}
+#endif /* CONFIG_NFSD_PNFS */
+
+static void encode_stateowner(struct xdr_stream *xdr, struct nfs4_stateowner *so)
+{
+	__be32	*p;
+
+	p = xdr_reserve_space(xdr, 8 + 4 + so->so_owner.len);
+	p = xdr_encode_opaque_fixed(p, &so->so_client->cl_clientid, 8);
+	xdr_encode_opaque(p, so->so_owner.data, so->so_owner.len);
+}
+
+static void nfs4_xdr_enc_cb_notify_lock(struct rpc_rqst *req,
+					struct xdr_stream *xdr,
+					const void *data)
+{
+	const struct nfsd4_callback *cb = data;
+	const struct nfsd4_blocked_lock *nbl =
+		container_of(cb, struct nfsd4_blocked_lock, nbl_cb);
+	struct nfs4_lockowner *lo = (struct nfs4_lockowner *)nbl->nbl_lock.fl_owner;
+	struct nfs4_cb_compound_hdr hdr = {
+		.ident = 0,
+		.minorversion = cb->cb_clp->cl_minorversion,
+	};
+
+	__be32 *p;
+
+	BUG_ON(hdr.minorversion == 0);
+
+	encode_cb_compound4args(xdr, &hdr);
+	encode_cb_sequence4args(xdr, cb, &hdr);
+
+	p = xdr_reserve_space(xdr, 4);
+	*p = cpu_to_be32(OP_CB_NOTIFY_LOCK);
+	encode_nfs_fh4(xdr, &nbl->nbl_fh);
+	encode_stateowner(xdr, &lo->lo_owner);
+	hdr.nops++;
+
+	encode_cb_nops(&hdr);
+}
+
+static int nfs4_xdr_dec_cb_notify_lock(struct rpc_rqst *rqstp,
+					struct xdr_stream *xdr,
+					void *data)
+{
+	struct nfsd4_callback *cb = data;
+	struct nfs4_cb_compound_hdr hdr;
+	int status;
+
+	status = decode_cb_compound4res(xdr, &hdr);
+	if (unlikely(status))
+		return status;
+
+	status = decode_cb_sequence4res(xdr, cb);
+	if (unlikely(status || cb->cb_seq_status))
+		return status;
+
+	return decode_cb_op_status(xdr, OP_CB_NOTIFY_LOCK, &cb->cb_status);
+}
+
+/*
+ * struct write_response4 {
+ *	stateid4	wr_callback_id<1>;
+ *	length4		wr_count;
+ *	stable_how4	wr_committed;
+ *	verifier4	wr_writeverf;
+ * };
+ * union offload_info4 switch (nfsstat4 coa_status) {
+ *	case NFS4_OK:
+ *		write_response4	coa_resok4;
+ *	default:
+ *	length4		coa_bytes_copied;
+ * };
+ * struct CB_OFFLOAD4args {
+ *	nfs_fh4		coa_fh;
+ *	stateid4	coa_stateid;
+ *	offload_info4	coa_offload_info;
+ * };
+ */
+static void encode_offload_info4(struct xdr_stream *xdr,
+				 __be32 nfserr,
+				 const struct nfsd4_copy *cp)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 4);
+	*p++ = nfserr;
+	if (!nfserr) {
+		p = xdr_reserve_space(xdr, 4 + 8 + 4 + NFS4_VERIFIER_SIZE);
+		p = xdr_encode_empty_array(p);
+		p = xdr_encode_hyper(p, cp->cp_res.wr_bytes_written);
+		*p++ = cpu_to_be32(cp->cp_res.wr_stable_how);
+		p = xdr_encode_opaque_fixed(p, cp->cp_res.wr_verifier.data,
+					    NFS4_VERIFIER_SIZE);
+	} else {
+		p = xdr_reserve_space(xdr, 8);
+		/* We always return success if bytes were written */
+		p = xdr_encode_hyper(p, 0);
+	}
+}
+
+static void encode_cb_offload4args(struct xdr_stream *xdr,
+				   __be32 nfserr,
+				   const struct knfsd_fh *fh,
+				   const struct nfsd4_copy *cp,
+				   struct nfs4_cb_compound_hdr *hdr)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 4);
+	*p++ = cpu_to_be32(OP_CB_OFFLOAD);
+	encode_nfs_fh4(xdr, fh);
+	encode_stateid4(xdr, &cp->cp_res.cb_stateid);
+	encode_offload_info4(xdr, nfserr, cp);
+
+	hdr->nops++;
+}
+
+static void nfs4_xdr_enc_cb_offload(struct rpc_rqst *req,
+				    struct xdr_stream *xdr,
+				    const void *data)
+{
+	const struct nfsd4_callback *cb = data;
+	const struct nfsd4_copy *cp =
+		container_of(cb, struct nfsd4_copy, cp_cb);
+	struct nfs4_cb_compound_hdr hdr = {
+		.ident = 0,
+		.minorversion = cb->cb_clp->cl_minorversion,
+	};
+
+	encode_cb_compound4args(xdr, &hdr);
+	encode_cb_sequence4args(xdr, cb, &hdr);
+	encode_cb_offload4args(xdr, cp->nfserr, &cp->fh, cp, &hdr);
+	encode_cb_nops(&hdr);
+}
+
+static int nfs4_xdr_dec_cb_offload(struct rpc_rqst *rqstp,
+				   struct xdr_stream *xdr,
+				   void *data)
+{
+	struct nfsd4_callback *cb = data;
+	struct nfs4_cb_compound_hdr hdr;
+	int status;
+
+	status = decode_cb_compound4res(xdr, &hdr);
+	if (unlikely(status))
+		return status;
+
+	status = decode_cb_sequence4res(xdr, cb);
+	if (unlikely(status || cb->cb_seq_status))
+		return status;
+
+	return decode_cb_op_status(xdr, OP_CB_OFFLOAD, &cb->cb_status);
+}
+/*
+ * RPC procedure tables
+ */
+#define PROC(proc, call, argtype, restype)				\
+[NFSPROC4_CLNT_##proc] = {						\
+	.p_proc    = NFSPROC4_CB_##call,				\
+	.p_encode  = nfs4_xdr_enc_##argtype,		\
+	.p_decode  = nfs4_xdr_dec_##restype,				\
+	.p_arglen  = NFS4_enc_##argtype##_sz,				\
+	.p_replen  = NFS4_dec_##restype##_sz,				\
+	.p_statidx = NFSPROC4_CB_##call,				\
+	.p_name    = #proc,						\
+}
+
+static const struct rpc_procinfo nfs4_cb_procedures[] = {
+	PROC(CB_NULL,	NULL,		cb_null,	cb_null),
+	PROC(CB_RECALL,	COMPOUND,	cb_recall,	cb_recall),
+#ifdef CONFIG_NFSD_PNFS
+	PROC(CB_LAYOUT,	COMPOUND,	cb_layout,	cb_layout),
+#endif
+	PROC(CB_NOTIFY_LOCK,	COMPOUND,	cb_notify_lock,	cb_notify_lock),
+	PROC(CB_OFFLOAD,	COMPOUND,	cb_offload,	cb_offload),
+};
+
+static unsigned int nfs4_cb_counts[ARRAY_SIZE(nfs4_cb_procedures)];
+static const struct rpc_version nfs_cb_version4 = {
+/*
+ * Note on the callback rpc program version number: despite language in rfc
+ * 5661 section 18.36.3 requiring servers to use 4 in this field, the
+ * official xdr descriptions for both 4.0 and 4.1 specify version 1, and
+ * in practice that appears to be what implementations use.  The section
+ * 18.36.3 language is expected to be fixed in an erratum.
+ */
+	.number			= 1,
+	.nrprocs		= ARRAY_SIZE(nfs4_cb_procedures),
+	.procs			= nfs4_cb_procedures,
+	.counts			= nfs4_cb_counts,
+};
+
+static const struct rpc_version *nfs_cb_version[2] = {
+	[1] = &nfs_cb_version4,
+};
+
+static const struct rpc_program cb_program;
+
+static struct rpc_stat cb_stats = {
+	.program		= &cb_program
+};
+
+#define NFS4_CALLBACK 0x40000000
+static const struct rpc_program cb_program = {
+	.name			= "nfs4_cb",
+	.number			= NFS4_CALLBACK,
+	.nrvers			= ARRAY_SIZE(nfs_cb_version),
+	.version		= nfs_cb_version,
+	.stats			= &cb_stats,
+	.pipe_dir_name		= "nfsd4_cb",
+};
+
+static int max_cb_time(struct net *net)
+{
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	/*
+	 * nfsd4_lease is set to at most one hour in __nfsd4_write_time,
+	 * so we can use 32-bit math on it. Warn if that assumption
+	 * ever stops being true.
+	 */
+	if (WARN_ON_ONCE(nn->nfsd4_lease > 3600))
+		return 360 * HZ;
+
+	return max(((u32)nn->nfsd4_lease)/10, 1u) * HZ;
+}
+
+static struct workqueue_struct *callback_wq;
+
+static bool nfsd4_queue_cb(struct nfsd4_callback *cb)
+{
+	return queue_work(callback_wq, &cb->cb_work);
+}
+
+static void nfsd41_cb_inflight_begin(struct nfs4_client *clp)
+{
+	atomic_inc(&clp->cl_cb_inflight);
+}
+
+static void nfsd41_cb_inflight_end(struct nfs4_client *clp)
+{
+
+	if (atomic_dec_and_test(&clp->cl_cb_inflight))
+		wake_up_var(&clp->cl_cb_inflight);
+}
+
+static void nfsd41_cb_inflight_wait_complete(struct nfs4_client *clp)
+{
+	wait_var_event(&clp->cl_cb_inflight,
+			!atomic_read(&clp->cl_cb_inflight));
+}
+
+static const struct cred *get_backchannel_cred(struct nfs4_client *clp, struct rpc_clnt *client, struct nfsd4_session *ses)
+{
+	if (clp->cl_minorversion == 0) {
+		client->cl_principal = clp->cl_cred.cr_targ_princ ?
+			clp->cl_cred.cr_targ_princ : "nfs";
+
+		return get_cred(rpc_machine_cred());
+	} else {
+		struct cred *kcred;
+
+		kcred = prepare_kernel_cred(NULL);
+		if (!kcred)
+			return NULL;
+
+		kcred->fsuid = ses->se_cb_sec.uid;
+		kcred->fsgid = ses->se_cb_sec.gid;
+		return kcred;
+	}
+}
+
+static int setup_callback_client(struct nfs4_client *clp, struct nfs4_cb_conn *conn, struct nfsd4_session *ses)
+{
+	int maxtime = max_cb_time(clp->net);
+	struct rpc_timeout	timeparms = {
+		.to_initval	= maxtime,
+		.to_retries	= 0,
+		.to_maxval	= maxtime,
+	};
+	struct rpc_create_args args = {
+		.net		= clp->net,
+		.address	= (struct sockaddr *) &conn->cb_addr,
+		.addrsize	= conn->cb_addrlen,
+		.saddress	= (struct sockaddr *) &conn->cb_saddr,
+		.timeout	= &timeparms,
+		.program	= &cb_program,
+		.version	= 1,
+		.flags		= (RPC_CLNT_CREATE_NOPING | RPC_CLNT_CREATE_QUIET),
+		.cred		= current_cred(),
+	};
+	struct rpc_clnt *client;
+	const struct cred *cred;
+
+	if (clp->cl_minorversion == 0) {
+		if (!clp->cl_cred.cr_principal &&
+		    (clp->cl_cred.cr_flavor >= RPC_AUTH_GSS_KRB5)) {
+			trace_nfsd_cb_setup_err(clp, -EINVAL);
+			return -EINVAL;
+		}
+		args.client_name = clp->cl_cred.cr_principal;
+		args.prognumber	= conn->cb_prog;
+		args.protocol = XPRT_TRANSPORT_TCP;
+		args.authflavor = clp->cl_cred.cr_flavor;
+		clp->cl_cb_ident = conn->cb_ident;
+	} else {
+		if (!conn->cb_xprt)
+			return -EINVAL;
+		clp->cl_cb_session = ses;
+		args.bc_xprt = conn->cb_xprt;
+		args.prognumber = clp->cl_cb_session->se_cb_prog;
+		args.protocol = conn->cb_xprt->xpt_class->xcl_ident |
+				XPRT_TRANSPORT_BC;
+		args.authflavor = ses->se_cb_sec.flavor;
+	}
+	/* Create RPC client */
+	client = rpc_create(&args);
+	if (IS_ERR(client)) {
+		trace_nfsd_cb_setup_err(clp, PTR_ERR(client));
+		return PTR_ERR(client);
+	}
+	cred = get_backchannel_cred(clp, client, ses);
+	if (!cred) {
+		trace_nfsd_cb_setup_err(clp, -ENOMEM);
+		rpc_shutdown_client(client);
+		return -ENOMEM;
+	}
+
+	if (clp->cl_minorversion != 0)
+		clp->cl_cb_conn.cb_xprt = conn->cb_xprt;
+	clp->cl_cb_client = client;
+	clp->cl_cb_cred = cred;
+	trace_nfsd_cb_setup(clp);
+	return 0;
+}
+
+static void nfsd4_mark_cb_down(struct nfs4_client *clp, int reason)
+{
+	if (test_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags))
+		return;
+	clp->cl_cb_state = NFSD4_CB_DOWN;
+	trace_nfsd_cb_state(clp);
+}
+
+static void nfsd4_mark_cb_fault(struct nfs4_client *clp, int reason)
+{
+	if (test_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags))
+		return;
+	clp->cl_cb_state = NFSD4_CB_FAULT;
+	trace_nfsd_cb_state(clp);
+}
+
+static void nfsd4_cb_probe_done(struct rpc_task *task, void *calldata)
+{
+	struct nfs4_client *clp = container_of(calldata, struct nfs4_client, cl_cb_null);
+
+	trace_nfsd_cb_done(clp, task->tk_status);
+	if (task->tk_status)
+		nfsd4_mark_cb_down(clp, task->tk_status);
+	else {
+		clp->cl_cb_state = NFSD4_CB_UP;
+		trace_nfsd_cb_state(clp);
+	}
+}
+
+static void nfsd4_cb_probe_release(void *calldata)
+{
+	struct nfs4_client *clp = container_of(calldata, struct nfs4_client, cl_cb_null);
+
+	nfsd41_cb_inflight_end(clp);
+
+}
+
+static const struct rpc_call_ops nfsd4_cb_probe_ops = {
+	/* XXX: release method to ensure we set the cb channel down if
+	 * necessary on early failure? */
+	.rpc_call_done = nfsd4_cb_probe_done,
+	.rpc_release = nfsd4_cb_probe_release,
+};
+
+/*
+ * Poke the callback thread to process any updates to the callback
+ * parameters, and send a null probe.
+ */
+void nfsd4_probe_callback(struct nfs4_client *clp)
+{
+	clp->cl_cb_state = NFSD4_CB_UNKNOWN;
+	trace_nfsd_cb_state(clp);
+	set_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags);
+	nfsd4_run_cb(&clp->cl_cb_null);
+}
+
+void nfsd4_probe_callback_sync(struct nfs4_client *clp)
+{
+	nfsd4_probe_callback(clp);
+	flush_workqueue(callback_wq);
+}
+
+void nfsd4_change_callback(struct nfs4_client *clp, struct nfs4_cb_conn *conn)
+{
+	clp->cl_cb_state = NFSD4_CB_UNKNOWN;
+	spin_lock(&clp->cl_lock);
+	memcpy(&clp->cl_cb_conn, conn, sizeof(struct nfs4_cb_conn));
+	spin_unlock(&clp->cl_lock);
+	trace_nfsd_cb_state(clp);
+}
+
+/*
+ * There's currently a single callback channel slot.
+ * If the slot is available, then mark it busy.  Otherwise, set the
+ * thread for sleeping on the callback RPC wait queue.
+ */
+static bool nfsd41_cb_get_slot(struct nfsd4_callback *cb, struct rpc_task *task)
+{
+	struct nfs4_client *clp = cb->cb_clp;
+
+	if (!cb->cb_holds_slot &&
+	    test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) {
+		rpc_sleep_on(&clp->cl_cb_waitq, task, NULL);
+		/* Race breaker */
+		if (test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) {
+			dprintk("%s slot is busy\n", __func__);
+			return false;
+		}
+		rpc_wake_up_queued_task(&clp->cl_cb_waitq, task);
+	}
+	cb->cb_holds_slot = true;
+	return true;
+}
+
+static void nfsd41_cb_release_slot(struct nfsd4_callback *cb)
+{
+	struct nfs4_client *clp = cb->cb_clp;
+
+	if (cb->cb_holds_slot) {
+		cb->cb_holds_slot = false;
+		clear_bit(0, &clp->cl_cb_slot_busy);
+		rpc_wake_up_next(&clp->cl_cb_waitq);
+	}
+}
+
+static void nfsd41_destroy_cb(struct nfsd4_callback *cb)
+{
+	struct nfs4_client *clp = cb->cb_clp;
+
+	nfsd41_cb_release_slot(cb);
+	if (cb->cb_ops && cb->cb_ops->release)
+		cb->cb_ops->release(cb);
+	nfsd41_cb_inflight_end(clp);
+}
+
+/*
+ * TODO: cb_sequence should support referring call lists, cachethis, multiple
+ * slots, and mark callback channel down on communication errors.
+ */
+static void nfsd4_cb_prepare(struct rpc_task *task, void *calldata)
+{
+	struct nfsd4_callback *cb = calldata;
+	struct nfs4_client *clp = cb->cb_clp;
+	u32 minorversion = clp->cl_minorversion;
+
+	/*
+	 * cb_seq_status is only set in decode_cb_sequence4res,
+	 * and so will remain 1 if an rpc level failure occurs.
+	 */
+	cb->cb_seq_status = 1;
+	cb->cb_status = 0;
+	if (minorversion && !nfsd41_cb_get_slot(cb, task))
+		return;
+	rpc_call_start(task);
+}
+
+static bool nfsd4_cb_sequence_done(struct rpc_task *task, struct nfsd4_callback *cb)
+{
+	struct nfs4_client *clp = cb->cb_clp;
+	struct nfsd4_session *session = clp->cl_cb_session;
+	bool ret = true;
+
+	if (!clp->cl_minorversion) {
+		/*
+		 * If the backchannel connection was shut down while this
+		 * task was queued, we need to resubmit it after setting up
+		 * a new backchannel connection.
+		 *
+		 * Note that if we lost our callback connection permanently
+		 * the submission code will error out, so we don't need to
+		 * handle that case here.
+		 */
+		if (RPC_SIGNALLED(task))
+			goto need_restart;
+
+		return true;
+	}
+
+	if (!cb->cb_holds_slot)
+		goto need_restart;
+
+	switch (cb->cb_seq_status) {
+	case 0:
+		/*
+		 * No need for lock, access serialized in nfsd4_cb_prepare
+		 *
+		 * RFC5661 20.9.3
+		 * If CB_SEQUENCE returns an error, then the state of the slot
+		 * (sequence ID, cached reply) MUST NOT change.
+		 */
+		++session->se_cb_seq_nr;
+		break;
+	case -ESERVERFAULT:
+		++session->se_cb_seq_nr;
+		fallthrough;
+	case 1:
+	case -NFS4ERR_BADSESSION:
+		nfsd4_mark_cb_fault(cb->cb_clp, cb->cb_seq_status);
+		ret = false;
+		break;
+	case -NFS4ERR_DELAY:
+		if (!rpc_restart_call(task))
+			goto out;
+
+		rpc_delay(task, 2 * HZ);
+		return false;
+	case -NFS4ERR_BADSLOT:
+		goto retry_nowait;
+	case -NFS4ERR_SEQ_MISORDERED:
+		if (session->se_cb_seq_nr != 1) {
+			session->se_cb_seq_nr = 1;
+			goto retry_nowait;
+		}
+		break;
+	default:
+		nfsd4_mark_cb_fault(cb->cb_clp, cb->cb_seq_status);
+		dprintk("%s: unprocessed error %d\n", __func__,
+			cb->cb_seq_status);
+	}
+
+	nfsd41_cb_release_slot(cb);
+	dprintk("%s: freed slot, new seqid=%d\n", __func__,
+		clp->cl_cb_session->se_cb_seq_nr);
+
+	if (RPC_SIGNALLED(task))
+		goto need_restart;
+out:
+	return ret;
+retry_nowait:
+	if (rpc_restart_call_prepare(task))
+		ret = false;
+	goto out;
+need_restart:
+	if (!test_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags)) {
+		task->tk_status = 0;
+		cb->cb_need_restart = true;
+	}
+	return false;
+}
+
+static void nfsd4_cb_done(struct rpc_task *task, void *calldata)
+{
+	struct nfsd4_callback *cb = calldata;
+	struct nfs4_client *clp = cb->cb_clp;
+
+	trace_nfsd_cb_done(clp, task->tk_status);
+
+	if (!nfsd4_cb_sequence_done(task, cb))
+		return;
+
+	if (cb->cb_status) {
+		WARN_ON_ONCE(task->tk_status);
+		task->tk_status = cb->cb_status;
+	}
+
+	switch (cb->cb_ops->done(cb, task)) {
+	case 0:
+		task->tk_status = 0;
+		rpc_restart_call_prepare(task);
+		return;
+	case 1:
+		switch (task->tk_status) {
+		case -EIO:
+		case -ETIMEDOUT:
+		case -EACCES:
+			nfsd4_mark_cb_down(clp, task->tk_status);
+		}
+		break;
+	default:
+		BUG();
+	}
+}
+
+static void nfsd4_cb_release(void *calldata)
+{
+	struct nfsd4_callback *cb = calldata;
+
+	if (cb->cb_need_restart)
+		nfsd4_queue_cb(cb);
+	else
+		nfsd41_destroy_cb(cb);
+
+}
+
+static const struct rpc_call_ops nfsd4_cb_ops = {
+	.rpc_call_prepare = nfsd4_cb_prepare,
+	.rpc_call_done = nfsd4_cb_done,
+	.rpc_release = nfsd4_cb_release,
+};
+
+int nfsd4_create_callback_queue(void)
+{
+	callback_wq = alloc_ordered_workqueue("nfsd4_callbacks", 0);
+	if (!callback_wq)
+		return -ENOMEM;
+	return 0;
+}
+
+void nfsd4_destroy_callback_queue(void)
+{
+	destroy_workqueue(callback_wq);
+}
+
+/* must be called under the state lock */
+void nfsd4_shutdown_callback(struct nfs4_client *clp)
+{
+	set_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags);
+	/*
+	 * Note this won't actually result in a null callback;
+	 * instead, nfsd4_run_cb_null() will detect the killed
+	 * client, destroy the rpc client, and stop:
+	 */
+	nfsd4_run_cb(&clp->cl_cb_null);
+	flush_workqueue(callback_wq);
+	nfsd41_cb_inflight_wait_complete(clp);
+}
+
+/* requires cl_lock: */
+static struct nfsd4_conn * __nfsd4_find_backchannel(struct nfs4_client *clp)
+{
+	struct nfsd4_session *s;
+	struct nfsd4_conn *c;
+
+	list_for_each_entry(s, &clp->cl_sessions, se_perclnt) {
+		list_for_each_entry(c, &s->se_conns, cn_persession) {
+			if (c->cn_flags & NFS4_CDFC4_BACK)
+				return c;
+		}
+	}
+	return NULL;
+}
+
+/*
+ * Note there isn't a lot of locking in this code; instead we depend on
+ * the fact that it is run from the callback_wq, which won't run two
+ * work items at once.  So, for example, callback_wq handles all access
+ * of cl_cb_client and all calls to rpc_create or rpc_shutdown_client.
+ */
+static void nfsd4_process_cb_update(struct nfsd4_callback *cb)
+{
+	struct nfs4_cb_conn conn;
+	struct nfs4_client *clp = cb->cb_clp;
+	struct nfsd4_session *ses = NULL;
+	struct nfsd4_conn *c;
+	int err;
+
+	/*
+	 * This is either an update, or the client dying; in either case,
+	 * kill the old client:
+	 */
+	if (clp->cl_cb_client) {
+		trace_nfsd_cb_shutdown(clp);
+		rpc_shutdown_client(clp->cl_cb_client);
+		clp->cl_cb_client = NULL;
+		put_cred(clp->cl_cb_cred);
+		clp->cl_cb_cred = NULL;
+	}
+	if (clp->cl_cb_conn.cb_xprt) {
+		svc_xprt_put(clp->cl_cb_conn.cb_xprt);
+		clp->cl_cb_conn.cb_xprt = NULL;
+	}
+	if (test_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags))
+		return;
+	spin_lock(&clp->cl_lock);
+	/*
+	 * Only serialized callback code is allowed to clear these
+	 * flags; main nfsd code can only set them:
+	 */
+	BUG_ON(!(clp->cl_flags & NFSD4_CLIENT_CB_FLAG_MASK));
+	clear_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags);
+	memcpy(&conn, &cb->cb_clp->cl_cb_conn, sizeof(struct nfs4_cb_conn));
+	c = __nfsd4_find_backchannel(clp);
+	if (c) {
+		svc_xprt_get(c->cn_xprt);
+		conn.cb_xprt = c->cn_xprt;
+		ses = c->cn_session;
+	}
+	spin_unlock(&clp->cl_lock);
+
+	err = setup_callback_client(clp, &conn, ses);
+	if (err) {
+		nfsd4_mark_cb_down(clp, err);
+		if (c)
+			svc_xprt_put(c->cn_xprt);
+		return;
+	}
+}
+
+static void
+nfsd4_run_cb_work(struct work_struct *work)
+{
+	struct nfsd4_callback *cb =
+		container_of(work, struct nfsd4_callback, cb_work);
+	struct nfs4_client *clp = cb->cb_clp;
+	struct rpc_clnt *clnt;
+	int flags;
+
+	trace_nfsd_cb_work(clp, cb->cb_msg.rpc_proc->p_name);
+
+	if (cb->cb_need_restart) {
+		cb->cb_need_restart = false;
+	} else {
+		if (cb->cb_ops && cb->cb_ops->prepare)
+			cb->cb_ops->prepare(cb);
+	}
+
+	if (clp->cl_flags & NFSD4_CLIENT_CB_FLAG_MASK)
+		nfsd4_process_cb_update(cb);
+
+	clnt = clp->cl_cb_client;
+	if (!clnt) {
+		/* Callback channel broken, or client killed; give up: */
+		nfsd41_destroy_cb(cb);
+		return;
+	}
+
+	/*
+	 * Don't send probe messages for 4.1 or later.
+	 */
+	if (!cb->cb_ops && clp->cl_minorversion) {
+		clp->cl_cb_state = NFSD4_CB_UP;
+		nfsd41_destroy_cb(cb);
+		return;
+	}
+
+	cb->cb_msg.rpc_cred = clp->cl_cb_cred;
+	flags = clp->cl_minorversion ? RPC_TASK_NOCONNECT : RPC_TASK_SOFTCONN;
+	rpc_call_async(clnt, &cb->cb_msg, RPC_TASK_SOFT | flags,
+			cb->cb_ops ? &nfsd4_cb_ops : &nfsd4_cb_probe_ops, cb);
+}
+
+void nfsd4_init_cb(struct nfsd4_callback *cb, struct nfs4_client *clp,
+		const struct nfsd4_callback_ops *ops, enum nfsd4_cb_op op)
+{
+	cb->cb_clp = clp;
+	cb->cb_msg.rpc_proc = &nfs4_cb_procedures[op];
+	cb->cb_msg.rpc_argp = cb;
+	cb->cb_msg.rpc_resp = cb;
+	cb->cb_ops = ops;
+	INIT_WORK(&cb->cb_work, nfsd4_run_cb_work);
+	cb->cb_seq_status = 1;
+	cb->cb_status = 0;
+	cb->cb_need_restart = false;
+	cb->cb_holds_slot = false;
+}
+
+void nfsd4_run_cb(struct nfsd4_callback *cb)
+{
+	struct nfs4_client *clp = cb->cb_clp;
+
+	nfsd41_cb_inflight_begin(clp);
+	if (!nfsd4_queue_cb(cb))
+		nfsd41_cb_inflight_end(clp);
+}
diff --git a/fs/nfsd/nfs4idmap.c b/fs/nfsd/nfs4idmap.c
new file mode 100644
index 000000000..f92161ce1
--- /dev/null
+++ b/fs/nfsd/nfs4idmap.c
@@ -0,0 +1,686 @@
+/*
+ *  Mapping of UID/GIDs to name and vice versa.
+ *
+ *  Copyright (c) 2002, 2003 The Regents of the University of
+ *  Michigan.  All rights reserved.
+ *
+ *  Marius Aamodt Eriksen <marius@umich.edu>
+ *
+ *  Redistribution and use in source and binary forms, with or without
+ *  modification, are permitted provided that the following conditions
+ *  are met:
+ *
+ *  1. Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *  2. Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *  3. Neither the name of the University nor the names of its
+ *     contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+ *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <linux/module.h>
+#include <linux/seq_file.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/sunrpc/svc_xprt.h>
+#include <net/net_namespace.h>
+#include "idmap.h"
+#include "nfsd.h"
+#include "netns.h"
+
+/*
+ * Turn off idmapping when using AUTH_SYS.
+ */
+static bool nfs4_disable_idmapping = true;
+module_param(nfs4_disable_idmapping, bool, 0644);
+MODULE_PARM_DESC(nfs4_disable_idmapping,
+		"Turn off server's NFSv4 idmapping when using 'sec=sys'");
+
+/*
+ * Cache entry
+ */
+
+/*
+ * XXX we know that IDMAP_NAMESZ < PAGE_SIZE, but it's ugly to rely on
+ * that.
+ */
+
+struct ent {
+	struct cache_head h;
+	int               type;		       /* User / Group */
+	u32               id;
+	char              name[IDMAP_NAMESZ];
+	char              authname[IDMAP_NAMESZ];
+	struct rcu_head	  rcu_head;
+};
+
+/* Common entry handling */
+
+#define ENT_HASHBITS          8
+#define ENT_HASHMAX           (1 << ENT_HASHBITS)
+
+static void
+ent_init(struct cache_head *cnew, struct cache_head *citm)
+{
+	struct ent *new = container_of(cnew, struct ent, h);
+	struct ent *itm = container_of(citm, struct ent, h);
+
+	new->id = itm->id;
+	new->type = itm->type;
+
+	strlcpy(new->name, itm->name, sizeof(new->name));
+	strlcpy(new->authname, itm->authname, sizeof(new->authname));
+}
+
+static void
+ent_put(struct kref *ref)
+{
+	struct ent *map = container_of(ref, struct ent, h.ref);
+	kfree_rcu(map, rcu_head);
+}
+
+static struct cache_head *
+ent_alloc(void)
+{
+	struct ent *e = kmalloc(sizeof(*e), GFP_KERNEL);
+	if (e)
+		return &e->h;
+	else
+		return NULL;
+}
+
+/*
+ * ID -> Name cache
+ */
+
+static uint32_t
+idtoname_hash(struct ent *ent)
+{
+	uint32_t hash;
+
+	hash = hash_str(ent->authname, ENT_HASHBITS);
+	hash = hash_long(hash ^ ent->id, ENT_HASHBITS);
+
+	/* Flip LSB for user/group */
+	if (ent->type == IDMAP_TYPE_GROUP)
+		hash ^= 1;
+
+	return hash;
+}
+
+static int
+idtoname_upcall(struct cache_detail *cd, struct cache_head *h)
+{
+	return sunrpc_cache_pipe_upcall_timeout(cd, h);
+}
+
+static void
+idtoname_request(struct cache_detail *cd, struct cache_head *ch, char **bpp,
+    int *blen)
+{
+ 	struct ent *ent = container_of(ch, struct ent, h);
+	char idstr[11];
+
+	qword_add(bpp, blen, ent->authname);
+	snprintf(idstr, sizeof(idstr), "%u", ent->id);
+	qword_add(bpp, blen, ent->type == IDMAP_TYPE_GROUP ? "group" : "user");
+	qword_add(bpp, blen, idstr);
+
+	(*bpp)[-1] = '\n';
+}
+
+static int
+idtoname_match(struct cache_head *ca, struct cache_head *cb)
+{
+	struct ent *a = container_of(ca, struct ent, h);
+	struct ent *b = container_of(cb, struct ent, h);
+
+	return (a->id == b->id && a->type == b->type &&
+	    strcmp(a->authname, b->authname) == 0);
+}
+
+static int
+idtoname_show(struct seq_file *m, struct cache_detail *cd, struct cache_head *h)
+{
+	struct ent *ent;
+
+	if (h == NULL) {
+		seq_puts(m, "#domain type id [name]\n");
+		return 0;
+	}
+	ent = container_of(h, struct ent, h);
+	seq_printf(m, "%s %s %u", ent->authname,
+			ent->type == IDMAP_TYPE_GROUP ? "group" : "user",
+			ent->id);
+	if (test_bit(CACHE_VALID, &h->flags))
+		seq_printf(m, " %s", ent->name);
+	seq_putc(m, '\n');
+	return 0;
+}
+
+static void
+warn_no_idmapd(struct cache_detail *detail, int has_died)
+{
+	printk("nfsd: nfsv4 idmapping failing: has idmapd %s?\n",
+			has_died ? "died" : "not been started");
+}
+
+
+static int         idtoname_parse(struct cache_detail *, char *, int);
+static struct ent *idtoname_lookup(struct cache_detail *, struct ent *);
+static struct ent *idtoname_update(struct cache_detail *, struct ent *,
+				   struct ent *);
+
+static const struct cache_detail idtoname_cache_template = {
+	.owner		= THIS_MODULE,
+	.hash_size	= ENT_HASHMAX,
+	.name		= "nfs4.idtoname",
+	.cache_put	= ent_put,
+	.cache_upcall	= idtoname_upcall,
+	.cache_request	= idtoname_request,
+	.cache_parse	= idtoname_parse,
+	.cache_show	= idtoname_show,
+	.warn_no_listener = warn_no_idmapd,
+	.match		= idtoname_match,
+	.init		= ent_init,
+	.update		= ent_init,
+	.alloc		= ent_alloc,
+};
+
+static int
+idtoname_parse(struct cache_detail *cd, char *buf, int buflen)
+{
+	struct ent ent, *res;
+	char *buf1, *bp;
+	int len;
+	int error = -EINVAL;
+
+	if (buf[buflen - 1] != '\n')
+		return (-EINVAL);
+	buf[buflen - 1]= '\0';
+
+	buf1 = kmalloc(PAGE_SIZE, GFP_KERNEL);
+	if (buf1 == NULL)
+		return (-ENOMEM);
+
+	memset(&ent, 0, sizeof(ent));
+
+	/* Authentication name */
+	len = qword_get(&buf, buf1, PAGE_SIZE);
+	if (len <= 0 || len >= IDMAP_NAMESZ)
+		goto out;
+	memcpy(ent.authname, buf1, sizeof(ent.authname));
+
+	/* Type */
+	if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
+		goto out;
+	ent.type = strcmp(buf1, "user") == 0 ?
+		IDMAP_TYPE_USER : IDMAP_TYPE_GROUP;
+
+	/* ID */
+	if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
+		goto out;
+	ent.id = simple_strtoul(buf1, &bp, 10);
+	if (bp == buf1)
+		goto out;
+
+	/* expiry */
+	ent.h.expiry_time = get_expiry(&buf);
+	if (ent.h.expiry_time == 0)
+		goto out;
+
+	error = -ENOMEM;
+	res = idtoname_lookup(cd, &ent);
+	if (!res)
+		goto out;
+
+	/* Name */
+	error = -EINVAL;
+	len = qword_get(&buf, buf1, PAGE_SIZE);
+	if (len < 0 || len >= IDMAP_NAMESZ)
+		goto out;
+	if (len == 0)
+		set_bit(CACHE_NEGATIVE, &ent.h.flags);
+	else
+		memcpy(ent.name, buf1, sizeof(ent.name));
+	error = -ENOMEM;
+	res = idtoname_update(cd, &ent, res);
+	if (res == NULL)
+		goto out;
+
+	cache_put(&res->h, cd);
+	error = 0;
+out:
+	kfree(buf1);
+	return error;
+}
+
+static struct ent *
+idtoname_lookup(struct cache_detail *cd, struct ent *item)
+{
+	struct cache_head *ch = sunrpc_cache_lookup_rcu(cd, &item->h,
+							idtoname_hash(item));
+	if (ch)
+		return container_of(ch, struct ent, h);
+	else
+		return NULL;
+}
+
+static struct ent *
+idtoname_update(struct cache_detail *cd, struct ent *new, struct ent *old)
+{
+	struct cache_head *ch = sunrpc_cache_update(cd, &new->h, &old->h,
+						    idtoname_hash(new));
+	if (ch)
+		return container_of(ch, struct ent, h);
+	else
+		return NULL;
+}
+
+
+/*
+ * Name -> ID cache
+ */
+
+static inline int
+nametoid_hash(struct ent *ent)
+{
+	return hash_str(ent->name, ENT_HASHBITS);
+}
+
+static int
+nametoid_upcall(struct cache_detail *cd, struct cache_head *h)
+{
+	return sunrpc_cache_pipe_upcall_timeout(cd, h);
+}
+
+static void
+nametoid_request(struct cache_detail *cd, struct cache_head *ch, char **bpp,
+    int *blen)
+{
+ 	struct ent *ent = container_of(ch, struct ent, h);
+
+	qword_add(bpp, blen, ent->authname);
+	qword_add(bpp, blen, ent->type == IDMAP_TYPE_GROUP ? "group" : "user");
+	qword_add(bpp, blen, ent->name);
+
+	(*bpp)[-1] = '\n';
+}
+
+static int
+nametoid_match(struct cache_head *ca, struct cache_head *cb)
+{
+	struct ent *a = container_of(ca, struct ent, h);
+	struct ent *b = container_of(cb, struct ent, h);
+
+	return (a->type == b->type && strcmp(a->name, b->name) == 0 &&
+	    strcmp(a->authname, b->authname) == 0);
+}
+
+static int
+nametoid_show(struct seq_file *m, struct cache_detail *cd, struct cache_head *h)
+{
+	struct ent *ent;
+
+	if (h == NULL) {
+		seq_puts(m, "#domain type name [id]\n");
+		return 0;
+	}
+	ent = container_of(h, struct ent, h);
+	seq_printf(m, "%s %s %s", ent->authname,
+			ent->type == IDMAP_TYPE_GROUP ? "group" : "user",
+			ent->name);
+	if (test_bit(CACHE_VALID, &h->flags))
+		seq_printf(m, " %u", ent->id);
+	seq_putc(m, '\n');
+	return 0;
+}
+
+static struct ent *nametoid_lookup(struct cache_detail *, struct ent *);
+static struct ent *nametoid_update(struct cache_detail *, struct ent *,
+				   struct ent *);
+static int         nametoid_parse(struct cache_detail *, char *, int);
+
+static const struct cache_detail nametoid_cache_template = {
+	.owner		= THIS_MODULE,
+	.hash_size	= ENT_HASHMAX,
+	.name		= "nfs4.nametoid",
+	.cache_put	= ent_put,
+	.cache_upcall	= nametoid_upcall,
+	.cache_request	= nametoid_request,
+	.cache_parse	= nametoid_parse,
+	.cache_show	= nametoid_show,
+	.warn_no_listener = warn_no_idmapd,
+	.match		= nametoid_match,
+	.init		= ent_init,
+	.update		= ent_init,
+	.alloc		= ent_alloc,
+};
+
+static int
+nametoid_parse(struct cache_detail *cd, char *buf, int buflen)
+{
+	struct ent ent, *res;
+	char *buf1;
+	int len, error = -EINVAL;
+
+	if (buf[buflen - 1] != '\n')
+		return (-EINVAL);
+	buf[buflen - 1]= '\0';
+
+	buf1 = kmalloc(PAGE_SIZE, GFP_KERNEL);
+	if (buf1 == NULL)
+		return (-ENOMEM);
+
+	memset(&ent, 0, sizeof(ent));
+
+	/* Authentication name */
+	len = qword_get(&buf, buf1, PAGE_SIZE);
+	if (len <= 0 || len >= IDMAP_NAMESZ)
+		goto out;
+	memcpy(ent.authname, buf1, sizeof(ent.authname));
+
+	/* Type */
+	if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
+		goto out;
+	ent.type = strcmp(buf1, "user") == 0 ?
+		IDMAP_TYPE_USER : IDMAP_TYPE_GROUP;
+
+	/* Name */
+	len = qword_get(&buf, buf1, PAGE_SIZE);
+	if (len <= 0 || len >= IDMAP_NAMESZ)
+		goto out;
+	memcpy(ent.name, buf1, sizeof(ent.name));
+
+	/* expiry */
+	ent.h.expiry_time = get_expiry(&buf);
+	if (ent.h.expiry_time == 0)
+		goto out;
+
+	/* ID */
+	error = get_int(&buf, &ent.id);
+	if (error == -EINVAL)
+		goto out;
+	if (error == -ENOENT)
+		set_bit(CACHE_NEGATIVE, &ent.h.flags);
+
+	error = -ENOMEM;
+	res = nametoid_lookup(cd, &ent);
+	if (res == NULL)
+		goto out;
+	res = nametoid_update(cd, &ent, res);
+	if (res == NULL)
+		goto out;
+
+	cache_put(&res->h, cd);
+	error = 0;
+out:
+	kfree(buf1);
+	return (error);
+}
+
+
+static struct ent *
+nametoid_lookup(struct cache_detail *cd, struct ent *item)
+{
+	struct cache_head *ch = sunrpc_cache_lookup_rcu(cd, &item->h,
+							nametoid_hash(item));
+	if (ch)
+		return container_of(ch, struct ent, h);
+	else
+		return NULL;
+}
+
+static struct ent *
+nametoid_update(struct cache_detail *cd, struct ent *new, struct ent *old)
+{
+	struct cache_head *ch = sunrpc_cache_update(cd, &new->h, &old->h,
+						    nametoid_hash(new));
+	if (ch)
+		return container_of(ch, struct ent, h);
+	else
+		return NULL;
+}
+
+/*
+ * Exported API
+ */
+
+int
+nfsd_idmap_init(struct net *net)
+{
+	int rv;
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	nn->idtoname_cache = cache_create_net(&idtoname_cache_template, net);
+	if (IS_ERR(nn->idtoname_cache))
+		return PTR_ERR(nn->idtoname_cache);
+	rv = cache_register_net(nn->idtoname_cache, net);
+	if (rv)
+		goto destroy_idtoname_cache;
+	nn->nametoid_cache = cache_create_net(&nametoid_cache_template, net);
+	if (IS_ERR(nn->nametoid_cache)) {
+		rv = PTR_ERR(nn->nametoid_cache);
+		goto unregister_idtoname_cache;
+	}
+	rv = cache_register_net(nn->nametoid_cache, net);
+	if (rv)
+		goto destroy_nametoid_cache;
+	return 0;
+
+destroy_nametoid_cache:
+	cache_destroy_net(nn->nametoid_cache, net);
+unregister_idtoname_cache:
+	cache_unregister_net(nn->idtoname_cache, net);
+destroy_idtoname_cache:
+	cache_destroy_net(nn->idtoname_cache, net);
+	return rv;
+}
+
+void
+nfsd_idmap_shutdown(struct net *net)
+{
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	cache_unregister_net(nn->idtoname_cache, net);
+	cache_unregister_net(nn->nametoid_cache, net);
+	cache_destroy_net(nn->idtoname_cache, net);
+	cache_destroy_net(nn->nametoid_cache, net);
+}
+
+static int
+idmap_lookup(struct svc_rqst *rqstp,
+		struct ent *(*lookup_fn)(struct cache_detail *, struct ent *),
+		struct ent *key, struct cache_detail *detail, struct ent **item)
+{
+	int ret;
+
+	*item = lookup_fn(detail, key);
+	if (!*item)
+		return -ENOMEM;
+ retry:
+	ret = cache_check(detail, &(*item)->h, &rqstp->rq_chandle);
+
+	if (ret == -ETIMEDOUT) {
+		struct ent *prev_item = *item;
+		*item = lookup_fn(detail, key);
+		if (*item != prev_item)
+			goto retry;
+		cache_put(&(*item)->h, detail);
+	}
+	return ret;
+}
+
+static char *
+rqst_authname(struct svc_rqst *rqstp)
+{
+	struct auth_domain *clp;
+
+	clp = rqstp->rq_gssclient ? rqstp->rq_gssclient : rqstp->rq_client;
+	return clp->name;
+}
+
+static __be32
+idmap_name_to_id(struct svc_rqst *rqstp, int type, const char *name, u32 namelen,
+		u32 *id)
+{
+	struct ent *item, key = {
+		.type = type,
+	};
+	int ret;
+	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+
+	if (namelen + 1 > sizeof(key.name))
+		return nfserr_badowner;
+	memcpy(key.name, name, namelen);
+	key.name[namelen] = '\0';
+	strlcpy(key.authname, rqst_authname(rqstp), sizeof(key.authname));
+	ret = idmap_lookup(rqstp, nametoid_lookup, &key, nn->nametoid_cache, &item);
+	if (ret == -ENOENT)
+		return nfserr_badowner;
+	if (ret)
+		return nfserrno(ret);
+	*id = item->id;
+	cache_put(&item->h, nn->nametoid_cache);
+	return 0;
+}
+
+static __be32 encode_ascii_id(struct xdr_stream *xdr, u32 id)
+{
+	char buf[11];
+	int len;
+	__be32 *p;
+
+	len = sprintf(buf, "%u", id);
+	p = xdr_reserve_space(xdr, len + 4);
+	if (!p)
+		return nfserr_resource;
+	p = xdr_encode_opaque(p, buf, len);
+	return 0;
+}
+
+static __be32 idmap_id_to_name(struct xdr_stream *xdr,
+			       struct svc_rqst *rqstp, int type, u32 id)
+{
+	struct ent *item, key = {
+		.id = id,
+		.type = type,
+	};
+	__be32 *p;
+	int ret;
+	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+
+	strlcpy(key.authname, rqst_authname(rqstp), sizeof(key.authname));
+	ret = idmap_lookup(rqstp, idtoname_lookup, &key, nn->idtoname_cache, &item);
+	if (ret == -ENOENT)
+		return encode_ascii_id(xdr, id);
+	if (ret)
+		return nfserrno(ret);
+	ret = strlen(item->name);
+	WARN_ON_ONCE(ret > IDMAP_NAMESZ);
+	p = xdr_reserve_space(xdr, ret + 4);
+	if (!p)
+		return nfserr_resource;
+	p = xdr_encode_opaque(p, item->name, ret);
+	cache_put(&item->h, nn->idtoname_cache);
+	return 0;
+}
+
+static bool
+numeric_name_to_id(struct svc_rqst *rqstp, int type, const char *name, u32 namelen, u32 *id)
+{
+	int ret;
+	char buf[11];
+
+	if (namelen + 1 > sizeof(buf))
+		/* too long to represent a 32-bit id: */
+		return false;
+	/* Just to make sure it's null-terminated: */
+	memcpy(buf, name, namelen);
+	buf[namelen] = '\0';
+	ret = kstrtouint(buf, 10, id);
+	return ret == 0;
+}
+
+static __be32
+do_name_to_id(struct svc_rqst *rqstp, int type, const char *name, u32 namelen, u32 *id)
+{
+	if (nfs4_disable_idmapping && rqstp->rq_cred.cr_flavor < RPC_AUTH_GSS)
+		if (numeric_name_to_id(rqstp, type, name, namelen, id))
+			return 0;
+		/*
+		 * otherwise, fall through and try idmapping, for
+		 * backwards compatibility with clients sending names:
+		 */
+	return idmap_name_to_id(rqstp, type, name, namelen, id);
+}
+
+static __be32 encode_name_from_id(struct xdr_stream *xdr,
+				  struct svc_rqst *rqstp, int type, u32 id)
+{
+	if (nfs4_disable_idmapping && rqstp->rq_cred.cr_flavor < RPC_AUTH_GSS)
+		return encode_ascii_id(xdr, id);
+	return idmap_id_to_name(xdr, rqstp, type, id);
+}
+
+__be32
+nfsd_map_name_to_uid(struct svc_rqst *rqstp, const char *name, size_t namelen,
+		kuid_t *uid)
+{
+	__be32 status;
+	u32 id = -1;
+
+	if (name == NULL || namelen == 0)
+		return nfserr_inval;
+
+	status = do_name_to_id(rqstp, IDMAP_TYPE_USER, name, namelen, &id);
+	*uid = make_kuid(nfsd_user_namespace(rqstp), id);
+	if (!uid_valid(*uid))
+		status = nfserr_badowner;
+	return status;
+}
+
+__be32
+nfsd_map_name_to_gid(struct svc_rqst *rqstp, const char *name, size_t namelen,
+		kgid_t *gid)
+{
+	__be32 status;
+	u32 id = -1;
+
+	if (name == NULL || namelen == 0)
+		return nfserr_inval;
+
+	status = do_name_to_id(rqstp, IDMAP_TYPE_GROUP, name, namelen, &id);
+	*gid = make_kgid(nfsd_user_namespace(rqstp), id);
+	if (!gid_valid(*gid))
+		status = nfserr_badowner;
+	return status;
+}
+
+__be32 nfsd4_encode_user(struct xdr_stream *xdr, struct svc_rqst *rqstp,
+			 kuid_t uid)
+{
+	u32 id = from_kuid_munged(nfsd_user_namespace(rqstp), uid);
+	return encode_name_from_id(xdr, rqstp, IDMAP_TYPE_USER, id);
+}
+
+__be32 nfsd4_encode_group(struct xdr_stream *xdr, struct svc_rqst *rqstp,
+			  kgid_t gid)
+{
+	u32 id = from_kgid_munged(nfsd_user_namespace(rqstp), gid);
+	return encode_name_from_id(xdr, rqstp, IDMAP_TYPE_GROUP, id);
+}
diff --git a/fs/nfsd/nfs4layouts.c b/fs/nfsd/nfs4layouts.c
new file mode 100644
index 000000000..2673019d3
--- /dev/null
+++ b/fs/nfsd/nfs4layouts.c
@@ -0,0 +1,786 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2014 Christoph Hellwig.
+ */
+#include <linux/blkdev.h>
+#include <linux/kmod.h>
+#include <linux/file.h>
+#include <linux/jhash.h>
+#include <linux/sched.h>
+#include <linux/sunrpc/addr.h>
+
+#include "pnfs.h"
+#include "netns.h"
+#include "trace.h"
+
+#define NFSDDBG_FACILITY                NFSDDBG_PNFS
+
+struct nfs4_layout {
+	struct list_head		lo_perstate;
+	struct nfs4_layout_stateid	*lo_state;
+	struct nfsd4_layout_seg		lo_seg;
+};
+
+static struct kmem_cache *nfs4_layout_cache;
+static struct kmem_cache *nfs4_layout_stateid_cache;
+
+static const struct nfsd4_callback_ops nfsd4_cb_layout_ops;
+static const struct lock_manager_operations nfsd4_layouts_lm_ops;
+
+const struct nfsd4_layout_ops *nfsd4_layout_ops[LAYOUT_TYPE_MAX] =  {
+#ifdef CONFIG_NFSD_FLEXFILELAYOUT
+	[LAYOUT_FLEX_FILES]	= &ff_layout_ops,
+#endif
+#ifdef CONFIG_NFSD_BLOCKLAYOUT
+	[LAYOUT_BLOCK_VOLUME]	= &bl_layout_ops,
+#endif
+#ifdef CONFIG_NFSD_SCSILAYOUT
+	[LAYOUT_SCSI]		= &scsi_layout_ops,
+#endif
+};
+
+/* pNFS device ID to export fsid mapping */
+#define DEVID_HASH_BITS	8
+#define DEVID_HASH_SIZE	(1 << DEVID_HASH_BITS)
+#define DEVID_HASH_MASK	(DEVID_HASH_SIZE - 1)
+static u64 nfsd_devid_seq = 1;
+static struct list_head nfsd_devid_hash[DEVID_HASH_SIZE];
+static DEFINE_SPINLOCK(nfsd_devid_lock);
+
+static inline u32 devid_hashfn(u64 idx)
+{
+	return jhash_2words(idx, idx >> 32, 0) & DEVID_HASH_MASK;
+}
+
+static void
+nfsd4_alloc_devid_map(const struct svc_fh *fhp)
+{
+	const struct knfsd_fh *fh = &fhp->fh_handle;
+	size_t fsid_len = key_len(fh->fh_fsid_type);
+	struct nfsd4_deviceid_map *map, *old;
+	int i;
+
+	map = kzalloc(sizeof(*map) + fsid_len, GFP_KERNEL);
+	if (!map)
+		return;
+
+	map->fsid_type = fh->fh_fsid_type;
+	memcpy(&map->fsid, fh->fh_fsid, fsid_len);
+
+	spin_lock(&nfsd_devid_lock);
+	if (fhp->fh_export->ex_devid_map)
+		goto out_unlock;
+
+	for (i = 0; i < DEVID_HASH_SIZE; i++) {
+		list_for_each_entry(old, &nfsd_devid_hash[i], hash) {
+			if (old->fsid_type != fh->fh_fsid_type)
+				continue;
+			if (memcmp(old->fsid, fh->fh_fsid,
+					key_len(old->fsid_type)))
+				continue;
+
+			fhp->fh_export->ex_devid_map = old;
+			goto out_unlock;
+		}
+	}
+
+	map->idx = nfsd_devid_seq++;
+	list_add_tail_rcu(&map->hash, &nfsd_devid_hash[devid_hashfn(map->idx)]);
+	fhp->fh_export->ex_devid_map = map;
+	map = NULL;
+
+out_unlock:
+	spin_unlock(&nfsd_devid_lock);
+	kfree(map);
+}
+
+struct nfsd4_deviceid_map *
+nfsd4_find_devid_map(int idx)
+{
+	struct nfsd4_deviceid_map *map, *ret = NULL;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(map, &nfsd_devid_hash[devid_hashfn(idx)], hash)
+		if (map->idx == idx)
+			ret = map;
+	rcu_read_unlock();
+
+	return ret;
+}
+
+int
+nfsd4_set_deviceid(struct nfsd4_deviceid *id, const struct svc_fh *fhp,
+		u32 device_generation)
+{
+	if (!fhp->fh_export->ex_devid_map) {
+		nfsd4_alloc_devid_map(fhp);
+		if (!fhp->fh_export->ex_devid_map)
+			return -ENOMEM;
+	}
+
+	id->fsid_idx = fhp->fh_export->ex_devid_map->idx;
+	id->generation = device_generation;
+	id->pad = 0;
+	return 0;
+}
+
+void nfsd4_setup_layout_type(struct svc_export *exp)
+{
+#if defined(CONFIG_NFSD_BLOCKLAYOUT) || defined(CONFIG_NFSD_SCSILAYOUT)
+	struct super_block *sb = exp->ex_path.mnt->mnt_sb;
+#endif
+
+	if (!(exp->ex_flags & NFSEXP_PNFS))
+		return;
+
+#ifdef CONFIG_NFSD_FLEXFILELAYOUT
+	exp->ex_layout_types |= 1 << LAYOUT_FLEX_FILES;
+#endif
+#ifdef CONFIG_NFSD_BLOCKLAYOUT
+	if (sb->s_export_op->get_uuid &&
+	    sb->s_export_op->map_blocks &&
+	    sb->s_export_op->commit_blocks)
+		exp->ex_layout_types |= 1 << LAYOUT_BLOCK_VOLUME;
+#endif
+#ifdef CONFIG_NFSD_SCSILAYOUT
+	if (sb->s_export_op->map_blocks &&
+	    sb->s_export_op->commit_blocks &&
+	    sb->s_bdev && sb->s_bdev->bd_disk->fops->pr_ops &&
+		blk_queue_scsi_passthrough(sb->s_bdev->bd_disk->queue))
+		exp->ex_layout_types |= 1 << LAYOUT_SCSI;
+#endif
+}
+
+static void
+nfsd4_free_layout_stateid(struct nfs4_stid *stid)
+{
+	struct nfs4_layout_stateid *ls = layoutstateid(stid);
+	struct nfs4_client *clp = ls->ls_stid.sc_client;
+	struct nfs4_file *fp = ls->ls_stid.sc_file;
+
+	trace_nfsd_layoutstate_free(&ls->ls_stid.sc_stateid);
+
+	spin_lock(&clp->cl_lock);
+	list_del_init(&ls->ls_perclnt);
+	spin_unlock(&clp->cl_lock);
+
+	spin_lock(&fp->fi_lock);
+	list_del_init(&ls->ls_perfile);
+	spin_unlock(&fp->fi_lock);
+
+	if (!nfsd4_layout_ops[ls->ls_layout_type]->disable_recalls)
+		vfs_setlease(ls->ls_file->nf_file, F_UNLCK, NULL, (void **)&ls);
+	nfsd_file_put(ls->ls_file);
+
+	if (ls->ls_recalled)
+		atomic_dec(&ls->ls_stid.sc_file->fi_lo_recalls);
+
+	kmem_cache_free(nfs4_layout_stateid_cache, ls);
+}
+
+static int
+nfsd4_layout_setlease(struct nfs4_layout_stateid *ls)
+{
+	struct file_lock *fl;
+	int status;
+
+	if (nfsd4_layout_ops[ls->ls_layout_type]->disable_recalls)
+		return 0;
+
+	fl = locks_alloc_lock();
+	if (!fl)
+		return -ENOMEM;
+	locks_init_lock(fl);
+	fl->fl_lmops = &nfsd4_layouts_lm_ops;
+	fl->fl_flags = FL_LAYOUT;
+	fl->fl_type = F_RDLCK;
+	fl->fl_end = OFFSET_MAX;
+	fl->fl_owner = ls;
+	fl->fl_pid = current->tgid;
+	fl->fl_file = ls->ls_file->nf_file;
+
+	status = vfs_setlease(fl->fl_file, fl->fl_type, &fl, NULL);
+	if (status) {
+		locks_free_lock(fl);
+		return status;
+	}
+	BUG_ON(fl != NULL);
+	return 0;
+}
+
+static struct nfs4_layout_stateid *
+nfsd4_alloc_layout_stateid(struct nfsd4_compound_state *cstate,
+		struct nfs4_stid *parent, u32 layout_type)
+{
+	struct nfs4_client *clp = cstate->clp;
+	struct nfs4_file *fp = parent->sc_file;
+	struct nfs4_layout_stateid *ls;
+	struct nfs4_stid *stp;
+
+	stp = nfs4_alloc_stid(cstate->clp, nfs4_layout_stateid_cache,
+					nfsd4_free_layout_stateid);
+	if (!stp)
+		return NULL;
+
+	get_nfs4_file(fp);
+	stp->sc_file = fp;
+
+	ls = layoutstateid(stp);
+	INIT_LIST_HEAD(&ls->ls_perclnt);
+	INIT_LIST_HEAD(&ls->ls_perfile);
+	spin_lock_init(&ls->ls_lock);
+	INIT_LIST_HEAD(&ls->ls_layouts);
+	mutex_init(&ls->ls_mutex);
+	ls->ls_layout_type = layout_type;
+	nfsd4_init_cb(&ls->ls_recall, clp, &nfsd4_cb_layout_ops,
+			NFSPROC4_CLNT_CB_LAYOUT);
+
+	if (parent->sc_type == NFS4_DELEG_STID)
+		ls->ls_file = nfsd_file_get(fp->fi_deleg_file);
+	else
+		ls->ls_file = find_any_file(fp);
+	BUG_ON(!ls->ls_file);
+
+	if (nfsd4_layout_setlease(ls)) {
+		nfsd_file_put(ls->ls_file);
+		put_nfs4_file(fp);
+		kmem_cache_free(nfs4_layout_stateid_cache, ls);
+		return NULL;
+	}
+
+	spin_lock(&clp->cl_lock);
+	stp->sc_type = NFS4_LAYOUT_STID;
+	list_add(&ls->ls_perclnt, &clp->cl_lo_states);
+	spin_unlock(&clp->cl_lock);
+
+	spin_lock(&fp->fi_lock);
+	list_add(&ls->ls_perfile, &fp->fi_lo_states);
+	spin_unlock(&fp->fi_lock);
+
+	trace_nfsd_layoutstate_alloc(&ls->ls_stid.sc_stateid);
+	return ls;
+}
+
+__be32
+nfsd4_preprocess_layout_stateid(struct svc_rqst *rqstp,
+		struct nfsd4_compound_state *cstate, stateid_t *stateid,
+		bool create, u32 layout_type, struct nfs4_layout_stateid **lsp)
+{
+	struct nfs4_layout_stateid *ls;
+	struct nfs4_stid *stid;
+	unsigned char typemask = NFS4_LAYOUT_STID;
+	__be32 status;
+
+	if (create)
+		typemask |= (NFS4_OPEN_STID | NFS4_LOCK_STID | NFS4_DELEG_STID);
+
+	status = nfsd4_lookup_stateid(cstate, stateid, typemask, &stid,
+			net_generic(SVC_NET(rqstp), nfsd_net_id));
+	if (status)
+		goto out;
+
+	if (!fh_match(&cstate->current_fh.fh_handle,
+		      &stid->sc_file->fi_fhandle)) {
+		status = nfserr_bad_stateid;
+		goto out_put_stid;
+	}
+
+	if (stid->sc_type != NFS4_LAYOUT_STID) {
+		ls = nfsd4_alloc_layout_stateid(cstate, stid, layout_type);
+		nfs4_put_stid(stid);
+
+		status = nfserr_jukebox;
+		if (!ls)
+			goto out;
+		mutex_lock(&ls->ls_mutex);
+	} else {
+		ls = container_of(stid, struct nfs4_layout_stateid, ls_stid);
+
+		status = nfserr_bad_stateid;
+		mutex_lock(&ls->ls_mutex);
+		if (nfsd4_stateid_generation_after(stateid, &stid->sc_stateid))
+			goto out_unlock_stid;
+		if (layout_type != ls->ls_layout_type)
+			goto out_unlock_stid;
+	}
+
+	*lsp = ls;
+	return 0;
+
+out_unlock_stid:
+	mutex_unlock(&ls->ls_mutex);
+out_put_stid:
+	nfs4_put_stid(stid);
+out:
+	return status;
+}
+
+static void
+nfsd4_recall_file_layout(struct nfs4_layout_stateid *ls)
+{
+	spin_lock(&ls->ls_lock);
+	if (ls->ls_recalled)
+		goto out_unlock;
+
+	if (list_empty(&ls->ls_layouts))
+		goto out_unlock;
+
+	ls->ls_recalled = true;
+	atomic_inc(&ls->ls_stid.sc_file->fi_lo_recalls);
+	trace_nfsd_layout_recall(&ls->ls_stid.sc_stateid);
+
+	refcount_inc(&ls->ls_stid.sc_count);
+	nfsd4_run_cb(&ls->ls_recall);
+
+out_unlock:
+	spin_unlock(&ls->ls_lock);
+}
+
+static inline u64
+layout_end(struct nfsd4_layout_seg *seg)
+{
+	u64 end = seg->offset + seg->length;
+	return end >= seg->offset ? end : NFS4_MAX_UINT64;
+}
+
+static void
+layout_update_len(struct nfsd4_layout_seg *lo, u64 end)
+{
+	if (end == NFS4_MAX_UINT64)
+		lo->length = NFS4_MAX_UINT64;
+	else
+		lo->length = end - lo->offset;
+}
+
+static bool
+layouts_overlapping(struct nfs4_layout *lo, struct nfsd4_layout_seg *s)
+{
+	if (s->iomode != IOMODE_ANY && s->iomode != lo->lo_seg.iomode)
+		return false;
+	if (layout_end(&lo->lo_seg) <= s->offset)
+		return false;
+	if (layout_end(s) <= lo->lo_seg.offset)
+		return false;
+	return true;
+}
+
+static bool
+layouts_try_merge(struct nfsd4_layout_seg *lo, struct nfsd4_layout_seg *new)
+{
+	if (lo->iomode != new->iomode)
+		return false;
+	if (layout_end(new) < lo->offset)
+		return false;
+	if (layout_end(lo) < new->offset)
+		return false;
+
+	lo->offset = min(lo->offset, new->offset);
+	layout_update_len(lo, max(layout_end(lo), layout_end(new)));
+	return true;
+}
+
+static __be32
+nfsd4_recall_conflict(struct nfs4_layout_stateid *ls)
+{
+	struct nfs4_file *fp = ls->ls_stid.sc_file;
+	struct nfs4_layout_stateid *l, *n;
+	__be32 nfserr = nfs_ok;
+
+	assert_spin_locked(&fp->fi_lock);
+
+	list_for_each_entry_safe(l, n, &fp->fi_lo_states, ls_perfile) {
+		if (l != ls) {
+			nfsd4_recall_file_layout(l);
+			nfserr = nfserr_recallconflict;
+		}
+	}
+
+	return nfserr;
+}
+
+__be32
+nfsd4_insert_layout(struct nfsd4_layoutget *lgp, struct nfs4_layout_stateid *ls)
+{
+	struct nfsd4_layout_seg *seg = &lgp->lg_seg;
+	struct nfs4_file *fp = ls->ls_stid.sc_file;
+	struct nfs4_layout *lp, *new = NULL;
+	__be32 nfserr;
+
+	spin_lock(&fp->fi_lock);
+	nfserr = nfsd4_recall_conflict(ls);
+	if (nfserr)
+		goto out;
+	spin_lock(&ls->ls_lock);
+	list_for_each_entry(lp, &ls->ls_layouts, lo_perstate) {
+		if (layouts_try_merge(&lp->lo_seg, seg))
+			goto done;
+	}
+	spin_unlock(&ls->ls_lock);
+	spin_unlock(&fp->fi_lock);
+
+	new = kmem_cache_alloc(nfs4_layout_cache, GFP_KERNEL);
+	if (!new)
+		return nfserr_jukebox;
+	memcpy(&new->lo_seg, seg, sizeof(lp->lo_seg));
+	new->lo_state = ls;
+
+	spin_lock(&fp->fi_lock);
+	nfserr = nfsd4_recall_conflict(ls);
+	if (nfserr)
+		goto out;
+	spin_lock(&ls->ls_lock);
+	list_for_each_entry(lp, &ls->ls_layouts, lo_perstate) {
+		if (layouts_try_merge(&lp->lo_seg, seg))
+			goto done;
+	}
+
+	refcount_inc(&ls->ls_stid.sc_count);
+	list_add_tail(&new->lo_perstate, &ls->ls_layouts);
+	new = NULL;
+done:
+	nfs4_inc_and_copy_stateid(&lgp->lg_sid, &ls->ls_stid);
+	spin_unlock(&ls->ls_lock);
+out:
+	spin_unlock(&fp->fi_lock);
+	if (new)
+		kmem_cache_free(nfs4_layout_cache, new);
+	return nfserr;
+}
+
+static void
+nfsd4_free_layouts(struct list_head *reaplist)
+{
+	while (!list_empty(reaplist)) {
+		struct nfs4_layout *lp = list_first_entry(reaplist,
+				struct nfs4_layout, lo_perstate);
+
+		list_del(&lp->lo_perstate);
+		nfs4_put_stid(&lp->lo_state->ls_stid);
+		kmem_cache_free(nfs4_layout_cache, lp);
+	}
+}
+
+static void
+nfsd4_return_file_layout(struct nfs4_layout *lp, struct nfsd4_layout_seg *seg,
+		struct list_head *reaplist)
+{
+	struct nfsd4_layout_seg *lo = &lp->lo_seg;
+	u64 end = layout_end(lo);
+
+	if (seg->offset <= lo->offset) {
+		if (layout_end(seg) >= end) {
+			list_move_tail(&lp->lo_perstate, reaplist);
+			return;
+		}
+		lo->offset = layout_end(seg);
+	} else {
+		/* retain the whole layout segment on a split. */
+		if (layout_end(seg) < end) {
+			dprintk("%s: split not supported\n", __func__);
+			return;
+		}
+		end = seg->offset;
+	}
+
+	layout_update_len(lo, end);
+}
+
+__be32
+nfsd4_return_file_layouts(struct svc_rqst *rqstp,
+		struct nfsd4_compound_state *cstate,
+		struct nfsd4_layoutreturn *lrp)
+{
+	struct nfs4_layout_stateid *ls;
+	struct nfs4_layout *lp, *n;
+	LIST_HEAD(reaplist);
+	__be32 nfserr;
+	int found = 0;
+
+	nfserr = nfsd4_preprocess_layout_stateid(rqstp, cstate, &lrp->lr_sid,
+						false, lrp->lr_layout_type,
+						&ls);
+	if (nfserr) {
+		trace_nfsd_layout_return_lookup_fail(&lrp->lr_sid);
+		return nfserr;
+	}
+
+	spin_lock(&ls->ls_lock);
+	list_for_each_entry_safe(lp, n, &ls->ls_layouts, lo_perstate) {
+		if (layouts_overlapping(lp, &lrp->lr_seg)) {
+			nfsd4_return_file_layout(lp, &lrp->lr_seg, &reaplist);
+			found++;
+		}
+	}
+	if (!list_empty(&ls->ls_layouts)) {
+		if (found)
+			nfs4_inc_and_copy_stateid(&lrp->lr_sid, &ls->ls_stid);
+		lrp->lrs_present = 1;
+	} else {
+		trace_nfsd_layoutstate_unhash(&ls->ls_stid.sc_stateid);
+		nfs4_unhash_stid(&ls->ls_stid);
+		lrp->lrs_present = 0;
+	}
+	spin_unlock(&ls->ls_lock);
+
+	mutex_unlock(&ls->ls_mutex);
+	nfs4_put_stid(&ls->ls_stid);
+	nfsd4_free_layouts(&reaplist);
+	return nfs_ok;
+}
+
+__be32
+nfsd4_return_client_layouts(struct svc_rqst *rqstp,
+		struct nfsd4_compound_state *cstate,
+		struct nfsd4_layoutreturn *lrp)
+{
+	struct nfs4_layout_stateid *ls, *n;
+	struct nfs4_client *clp = cstate->clp;
+	struct nfs4_layout *lp, *t;
+	LIST_HEAD(reaplist);
+
+	lrp->lrs_present = 0;
+
+	spin_lock(&clp->cl_lock);
+	list_for_each_entry_safe(ls, n, &clp->cl_lo_states, ls_perclnt) {
+		if (ls->ls_layout_type != lrp->lr_layout_type)
+			continue;
+
+		if (lrp->lr_return_type == RETURN_FSID &&
+		    !fh_fsid_match(&ls->ls_stid.sc_file->fi_fhandle,
+				   &cstate->current_fh.fh_handle))
+			continue;
+
+		spin_lock(&ls->ls_lock);
+		list_for_each_entry_safe(lp, t, &ls->ls_layouts, lo_perstate) {
+			if (lrp->lr_seg.iomode == IOMODE_ANY ||
+			    lrp->lr_seg.iomode == lp->lo_seg.iomode)
+				list_move_tail(&lp->lo_perstate, &reaplist);
+		}
+		spin_unlock(&ls->ls_lock);
+	}
+	spin_unlock(&clp->cl_lock);
+
+	nfsd4_free_layouts(&reaplist);
+	return 0;
+}
+
+static void
+nfsd4_return_all_layouts(struct nfs4_layout_stateid *ls,
+		struct list_head *reaplist)
+{
+	spin_lock(&ls->ls_lock);
+	list_splice_init(&ls->ls_layouts, reaplist);
+	spin_unlock(&ls->ls_lock);
+}
+
+void
+nfsd4_return_all_client_layouts(struct nfs4_client *clp)
+{
+	struct nfs4_layout_stateid *ls, *n;
+	LIST_HEAD(reaplist);
+
+	spin_lock(&clp->cl_lock);
+	list_for_each_entry_safe(ls, n, &clp->cl_lo_states, ls_perclnt)
+		nfsd4_return_all_layouts(ls, &reaplist);
+	spin_unlock(&clp->cl_lock);
+
+	nfsd4_free_layouts(&reaplist);
+}
+
+void
+nfsd4_return_all_file_layouts(struct nfs4_client *clp, struct nfs4_file *fp)
+{
+	struct nfs4_layout_stateid *ls, *n;
+	LIST_HEAD(reaplist);
+
+	spin_lock(&fp->fi_lock);
+	list_for_each_entry_safe(ls, n, &fp->fi_lo_states, ls_perfile) {
+		if (ls->ls_stid.sc_client == clp)
+			nfsd4_return_all_layouts(ls, &reaplist);
+	}
+	spin_unlock(&fp->fi_lock);
+
+	nfsd4_free_layouts(&reaplist);
+}
+
+static void
+nfsd4_cb_layout_fail(struct nfs4_layout_stateid *ls)
+{
+	struct nfs4_client *clp = ls->ls_stid.sc_client;
+	char addr_str[INET6_ADDRSTRLEN];
+	static char const nfsd_recall_failed[] = "/sbin/nfsd-recall-failed";
+	static char *envp[] = {
+		"HOME=/",
+		"TERM=linux",
+		"PATH=/sbin:/usr/sbin:/bin:/usr/bin",
+		NULL
+	};
+	char *argv[8];
+	int error;
+
+	rpc_ntop((struct sockaddr *)&clp->cl_addr, addr_str, sizeof(addr_str));
+
+	printk(KERN_WARNING
+		"nfsd: client %s failed to respond to layout recall. "
+		"  Fencing..\n", addr_str);
+
+	argv[0] = (char *)nfsd_recall_failed;
+	argv[1] = addr_str;
+	argv[2] = ls->ls_file->nf_file->f_path.mnt->mnt_sb->s_id;
+	argv[3] = NULL;
+
+	error = call_usermodehelper(nfsd_recall_failed, argv, envp,
+				    UMH_WAIT_PROC);
+	if (error) {
+		printk(KERN_ERR "nfsd: fence failed for client %s: %d!\n",
+			addr_str, error);
+	}
+}
+
+static void
+nfsd4_cb_layout_prepare(struct nfsd4_callback *cb)
+{
+	struct nfs4_layout_stateid *ls =
+		container_of(cb, struct nfs4_layout_stateid, ls_recall);
+
+	mutex_lock(&ls->ls_mutex);
+	nfs4_inc_and_copy_stateid(&ls->ls_recall_sid, &ls->ls_stid);
+	mutex_unlock(&ls->ls_mutex);
+}
+
+static int
+nfsd4_cb_layout_done(struct nfsd4_callback *cb, struct rpc_task *task)
+{
+	struct nfs4_layout_stateid *ls =
+		container_of(cb, struct nfs4_layout_stateid, ls_recall);
+	struct nfsd_net *nn;
+	ktime_t now, cutoff;
+	const struct nfsd4_layout_ops *ops;
+
+
+	switch (task->tk_status) {
+	case 0:
+	case -NFS4ERR_DELAY:
+		/*
+		 * Anything left? If not, then call it done. Note that we don't
+		 * take the spinlock since this is an optimization and nothing
+		 * should get added until the cb counter goes to zero.
+		 */
+		if (list_empty(&ls->ls_layouts))
+			return 1;
+
+		/* Poll the client until it's done with the layout */
+		now = ktime_get();
+		nn = net_generic(ls->ls_stid.sc_client->net, nfsd_net_id);
+
+		/* Client gets 2 lease periods to return it */
+		cutoff = ktime_add_ns(task->tk_start,
+					 (u64)nn->nfsd4_lease * NSEC_PER_SEC * 2);
+
+		if (ktime_before(now, cutoff)) {
+			rpc_delay(task, HZ/100); /* 10 mili-seconds */
+			return 0;
+		}
+		fallthrough;
+	default:
+		/*
+		 * Unknown error or non-responding client, we'll need to fence.
+		 */
+		trace_nfsd_layout_recall_fail(&ls->ls_stid.sc_stateid);
+
+		ops = nfsd4_layout_ops[ls->ls_layout_type];
+		if (ops->fence_client)
+			ops->fence_client(ls);
+		else
+			nfsd4_cb_layout_fail(ls);
+		return 1;
+	case -NFS4ERR_NOMATCHING_LAYOUT:
+		trace_nfsd_layout_recall_done(&ls->ls_stid.sc_stateid);
+		task->tk_status = 0;
+		return 1;
+	}
+}
+
+static void
+nfsd4_cb_layout_release(struct nfsd4_callback *cb)
+{
+	struct nfs4_layout_stateid *ls =
+		container_of(cb, struct nfs4_layout_stateid, ls_recall);
+	LIST_HEAD(reaplist);
+
+	trace_nfsd_layout_recall_release(&ls->ls_stid.sc_stateid);
+
+	nfsd4_return_all_layouts(ls, &reaplist);
+	nfsd4_free_layouts(&reaplist);
+	nfs4_put_stid(&ls->ls_stid);
+}
+
+static const struct nfsd4_callback_ops nfsd4_cb_layout_ops = {
+	.prepare	= nfsd4_cb_layout_prepare,
+	.done		= nfsd4_cb_layout_done,
+	.release	= nfsd4_cb_layout_release,
+};
+
+static bool
+nfsd4_layout_lm_break(struct file_lock *fl)
+{
+	/*
+	 * We don't want the locks code to timeout the lease for us;
+	 * we'll remove it ourself if a layout isn't returned
+	 * in time:
+	 */
+	fl->fl_break_time = 0;
+	nfsd4_recall_file_layout(fl->fl_owner);
+	return false;
+}
+
+static int
+nfsd4_layout_lm_change(struct file_lock *onlist, int arg,
+		struct list_head *dispose)
+{
+	BUG_ON(!(arg & F_UNLCK));
+	return lease_modify(onlist, arg, dispose);
+}
+
+static const struct lock_manager_operations nfsd4_layouts_lm_ops = {
+	.lm_break	= nfsd4_layout_lm_break,
+	.lm_change	= nfsd4_layout_lm_change,
+};
+
+int
+nfsd4_init_pnfs(void)
+{
+	int i;
+
+	for (i = 0; i < DEVID_HASH_SIZE; i++)
+		INIT_LIST_HEAD(&nfsd_devid_hash[i]);
+
+	nfs4_layout_cache = kmem_cache_create("nfs4_layout",
+			sizeof(struct nfs4_layout), 0, 0, NULL);
+	if (!nfs4_layout_cache)
+		return -ENOMEM;
+
+	nfs4_layout_stateid_cache = kmem_cache_create("nfs4_layout_stateid",
+			sizeof(struct nfs4_layout_stateid), 0, 0, NULL);
+	if (!nfs4_layout_stateid_cache) {
+		kmem_cache_destroy(nfs4_layout_cache);
+		return -ENOMEM;
+	}
+	return 0;
+}
+
+void
+nfsd4_exit_pnfs(void)
+{
+	int i;
+
+	kmem_cache_destroy(nfs4_layout_cache);
+	kmem_cache_destroy(nfs4_layout_stateid_cache);
+
+	for (i = 0; i < DEVID_HASH_SIZE; i++) {
+		struct nfsd4_deviceid_map *map, *n;
+
+		list_for_each_entry_safe(map, n, &nfsd_devid_hash[i], hash)
+			kfree(map);
+	}
+}
diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
new file mode 100644
index 000000000..e84996c38
--- /dev/null
+++ b/fs/nfsd/nfs4proc.c
@@ -0,0 +1,3329 @@
+/*
+ *  Server-side procedures for NFSv4.
+ *
+ *  Copyright (c) 2002 The Regents of the University of Michigan.
+ *  All rights reserved.
+ *
+ *  Kendrick Smith <kmsmith@umich.edu>
+ *  Andy Adamson   <andros@umich.edu>
+ *
+ *  Redistribution and use in source and binary forms, with or without
+ *  modification, are permitted provided that the following conditions
+ *  are met:
+ *
+ *  1. Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *  2. Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *  3. Neither the name of the University nor the names of its
+ *     contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+ *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+#include <linux/fs_struct.h>
+#include <linux/file.h>
+#include <linux/falloc.h>
+#include <linux/slab.h>
+#include <linux/kthread.h>
+#include <linux/sunrpc/addr.h>
+#include <linux/nfs_ssc.h>
+
+#include "idmap.h"
+#include "cache.h"
+#include "xdr4.h"
+#include "vfs.h"
+#include "current_stateid.h"
+#include "netns.h"
+#include "acl.h"
+#include "pnfs.h"
+#include "trace.h"
+
+#ifdef CONFIG_NFSD_V4_SECURITY_LABEL
+#include <linux/security.h>
+
+static inline void
+nfsd4_security_inode_setsecctx(struct svc_fh *resfh, struct xdr_netobj *label, u32 *bmval)
+{
+	struct inode *inode = d_inode(resfh->fh_dentry);
+	int status;
+
+	inode_lock(inode);
+	status = security_inode_setsecctx(resfh->fh_dentry,
+		label->data, label->len);
+	inode_unlock(inode);
+
+	if (status)
+		/*
+		 * XXX: We should really fail the whole open, but we may
+		 * already have created a new file, so it may be too
+		 * late.  For now this seems the least of evils:
+		 */
+		bmval[2] &= ~FATTR4_WORD2_SECURITY_LABEL;
+
+	return;
+}
+#else
+static inline void
+nfsd4_security_inode_setsecctx(struct svc_fh *resfh, struct xdr_netobj *label, u32 *bmval)
+{ }
+#endif
+
+#define NFSDDBG_FACILITY		NFSDDBG_PROC
+
+static u32 nfsd_attrmask[] = {
+	NFSD_WRITEABLE_ATTRS_WORD0,
+	NFSD_WRITEABLE_ATTRS_WORD1,
+	NFSD_WRITEABLE_ATTRS_WORD2
+};
+
+static u32 nfsd41_ex_attrmask[] = {
+	NFSD_SUPPATTR_EXCLCREAT_WORD0,
+	NFSD_SUPPATTR_EXCLCREAT_WORD1,
+	NFSD_SUPPATTR_EXCLCREAT_WORD2
+};
+
+static __be32
+check_attr_support(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+		   u32 *bmval, u32 *writable)
+{
+	struct dentry *dentry = cstate->current_fh.fh_dentry;
+	struct svc_export *exp = cstate->current_fh.fh_export;
+
+	if (!nfsd_attrs_supported(cstate->minorversion, bmval))
+		return nfserr_attrnotsupp;
+	if ((bmval[0] & FATTR4_WORD0_ACL) && !IS_POSIXACL(d_inode(dentry)))
+		return nfserr_attrnotsupp;
+	if ((bmval[2] & FATTR4_WORD2_SECURITY_LABEL) &&
+			!(exp->ex_flags & NFSEXP_SECURITY_LABEL))
+		return nfserr_attrnotsupp;
+	if (writable && !bmval_is_subset(bmval, writable))
+		return nfserr_inval;
+	if (writable && (bmval[2] & FATTR4_WORD2_MODE_UMASK) &&
+			(bmval[1] & FATTR4_WORD1_MODE))
+		return nfserr_inval;
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_check_open_attributes(struct svc_rqst *rqstp,
+	struct nfsd4_compound_state *cstate, struct nfsd4_open *open)
+{
+	__be32 status = nfs_ok;
+
+	if (open->op_create == NFS4_OPEN_CREATE) {
+		if (open->op_createmode == NFS4_CREATE_UNCHECKED
+		    || open->op_createmode == NFS4_CREATE_GUARDED)
+			status = check_attr_support(rqstp, cstate,
+					open->op_bmval, nfsd_attrmask);
+		else if (open->op_createmode == NFS4_CREATE_EXCLUSIVE4_1)
+			status = check_attr_support(rqstp, cstate,
+					open->op_bmval, nfsd41_ex_attrmask);
+	}
+
+	return status;
+}
+
+static int
+is_create_with_attrs(struct nfsd4_open *open)
+{
+	return open->op_create == NFS4_OPEN_CREATE
+		&& (open->op_createmode == NFS4_CREATE_UNCHECKED
+		    || open->op_createmode == NFS4_CREATE_GUARDED
+		    || open->op_createmode == NFS4_CREATE_EXCLUSIVE4_1);
+}
+
+/*
+ * if error occurs when setting the acl, just clear the acl bit
+ * in the returned attr bitmap.
+ */
+static void
+do_set_nfs4_acl(struct svc_rqst *rqstp, struct svc_fh *fhp,
+		struct nfs4_acl *acl, u32 *bmval)
+{
+	__be32 status;
+
+	status = nfsd4_set_nfs4_acl(rqstp, fhp, acl);
+	if (status)
+		/*
+		 * We should probably fail the whole open at this point,
+		 * but we've already created the file, so it's too late;
+		 * So this seems the least of evils:
+		 */
+		bmval[0] &= ~FATTR4_WORD0_ACL;
+}
+
+static inline void
+fh_dup2(struct svc_fh *dst, struct svc_fh *src)
+{
+	fh_put(dst);
+	dget(src->fh_dentry);
+	if (src->fh_export)
+		exp_get(src->fh_export);
+	*dst = *src;
+}
+
+static __be32
+do_open_permission(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nfsd4_open *open, int accmode)
+{
+	__be32 status;
+
+	if (open->op_truncate &&
+		!(open->op_share_access & NFS4_SHARE_ACCESS_WRITE))
+		return nfserr_inval;
+
+	accmode |= NFSD_MAY_READ_IF_EXEC;
+
+	if (open->op_share_access & NFS4_SHARE_ACCESS_READ)
+		accmode |= NFSD_MAY_READ;
+	if (open->op_share_access & NFS4_SHARE_ACCESS_WRITE)
+		accmode |= (NFSD_MAY_WRITE | NFSD_MAY_TRUNC);
+	if (open->op_share_deny & NFS4_SHARE_DENY_READ)
+		accmode |= NFSD_MAY_WRITE;
+
+	status = fh_verify(rqstp, current_fh, S_IFREG, accmode);
+
+	return status;
+}
+
+static __be32 nfsd_check_obj_isreg(struct svc_fh *fh)
+{
+	umode_t mode = d_inode(fh->fh_dentry)->i_mode;
+
+	if (S_ISREG(mode))
+		return nfs_ok;
+	if (S_ISDIR(mode))
+		return nfserr_isdir;
+	/*
+	 * Using err_symlink as our catch-all case may look odd; but
+	 * there's no other obvious error for this case in 4.0, and we
+	 * happen to know that it will cause the linux v4 client to do
+	 * the right thing on attempts to open something other than a
+	 * regular file.
+	 */
+	return nfserr_symlink;
+}
+
+static void nfsd4_set_open_owner_reply_cache(struct nfsd4_compound_state *cstate, struct nfsd4_open *open, struct svc_fh *resfh)
+{
+	if (nfsd4_has_session(cstate))
+		return;
+	fh_copy_shallow(&open->op_openowner->oo_owner.so_replay.rp_openfh,
+			&resfh->fh_handle);
+}
+
+static __be32
+do_open_lookup(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, struct nfsd4_open *open, struct svc_fh **resfh)
+{
+	struct svc_fh *current_fh = &cstate->current_fh;
+	int accmode;
+	__be32 status;
+
+	*resfh = kmalloc(sizeof(struct svc_fh), GFP_KERNEL);
+	if (!*resfh)
+		return nfserr_jukebox;
+	fh_init(*resfh, NFS4_FHSIZE);
+	open->op_truncate = false;
+
+	if (open->op_create) {
+		/* FIXME: check session persistence and pnfs flags.
+		 * The nfsv4.1 spec requires the following semantics:
+		 *
+		 * Persistent   | pNFS   | Server REQUIRED | Client Allowed
+		 * Reply Cache  | server |                 |
+		 * -------------+--------+-----------------+--------------------
+		 * no           | no     | EXCLUSIVE4_1    | EXCLUSIVE4_1
+		 *              |        |                 | (SHOULD)
+		 *              |        | and EXCLUSIVE4  | or EXCLUSIVE4
+		 *              |        |                 | (SHOULD NOT)
+		 * no           | yes    | EXCLUSIVE4_1    | EXCLUSIVE4_1
+		 * yes          | no     | GUARDED4        | GUARDED4
+		 * yes          | yes    | GUARDED4        | GUARDED4
+		 */
+
+		/*
+		 * Note: create modes (UNCHECKED,GUARDED...) are the same
+		 * in NFSv4 as in v3 except EXCLUSIVE4_1.
+		 */
+		current->fs->umask = open->op_umask;
+		status = do_nfsd_create(rqstp, current_fh, open->op_fname.data,
+					open->op_fname.len, &open->op_iattr,
+					*resfh, open->op_createmode,
+					(u32 *)open->op_verf.data,
+					&open->op_truncate, &open->op_created);
+		current->fs->umask = 0;
+
+		if (!status && open->op_label.len)
+			nfsd4_security_inode_setsecctx(*resfh, &open->op_label, open->op_bmval);
+
+		/*
+		 * Following rfc 3530 14.2.16, and rfc 5661 18.16.4
+		 * use the returned bitmask to indicate which attributes
+		 * we used to store the verifier:
+		 */
+		if (nfsd_create_is_exclusive(open->op_createmode) && status == 0)
+			open->op_bmval[1] |= (FATTR4_WORD1_TIME_ACCESS |
+						FATTR4_WORD1_TIME_MODIFY);
+	} else
+		/*
+		 * Note this may exit with the parent still locked.
+		 * We will hold the lock until nfsd4_open's final
+		 * lookup, to prevent renames or unlinks until we've had
+		 * a chance to an acquire a delegation if appropriate.
+		 */
+		status = nfsd_lookup(rqstp, current_fh,
+				     open->op_fname.data, open->op_fname.len, *resfh);
+	if (status)
+		goto out;
+	status = nfsd_check_obj_isreg(*resfh);
+	if (status)
+		goto out;
+
+	if (is_create_with_attrs(open) && open->op_acl != NULL)
+		do_set_nfs4_acl(rqstp, *resfh, open->op_acl, open->op_bmval);
+
+	nfsd4_set_open_owner_reply_cache(cstate, open, *resfh);
+	accmode = NFSD_MAY_NOP;
+	if (open->op_created ||
+			open->op_claim_type == NFS4_OPEN_CLAIM_DELEGATE_CUR)
+		accmode |= NFSD_MAY_OWNER_OVERRIDE;
+	status = do_open_permission(rqstp, *resfh, open, accmode);
+	set_change_info(&open->op_cinfo, current_fh);
+out:
+	return status;
+}
+
+static __be32
+do_open_fhandle(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, struct nfsd4_open *open)
+{
+	struct svc_fh *current_fh = &cstate->current_fh;
+	__be32 status;
+	int accmode = 0;
+
+	/* We don't know the target directory, and therefore can not
+	* set the change info
+	*/
+
+	memset(&open->op_cinfo, 0, sizeof(struct nfsd4_change_info));
+
+	nfsd4_set_open_owner_reply_cache(cstate, open, current_fh);
+
+	open->op_truncate = (open->op_iattr.ia_valid & ATTR_SIZE) &&
+		(open->op_iattr.ia_size == 0);
+	/*
+	 * In the delegation case, the client is telling us about an
+	 * open that it *already* performed locally, some time ago.  We
+	 * should let it succeed now if possible.
+	 *
+	 * In the case of a CLAIM_FH open, on the other hand, the client
+	 * may be counting on us to enforce permissions (the Linux 4.1
+	 * client uses this for normal opens, for example).
+	 */
+	if (open->op_claim_type == NFS4_OPEN_CLAIM_DELEG_CUR_FH)
+		accmode = NFSD_MAY_OWNER_OVERRIDE;
+
+	status = do_open_permission(rqstp, current_fh, open, accmode);
+
+	return status;
+}
+
+static void
+copy_clientid(clientid_t *clid, struct nfsd4_session *session)
+{
+	struct nfsd4_sessionid *sid =
+			(struct nfsd4_sessionid *)session->se_sessionid.data;
+
+	clid->cl_boot = sid->clientid.cl_boot;
+	clid->cl_id = sid->clientid.cl_id;
+}
+
+static __be32
+nfsd4_open(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+	   union nfsd4_op_u *u)
+{
+	struct nfsd4_open *open = &u->open;
+	__be32 status;
+	struct svc_fh *resfh = NULL;
+	struct net *net = SVC_NET(rqstp);
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+	bool reclaim = false;
+
+	dprintk("NFSD: nfsd4_open filename %.*s op_openowner %p\n",
+		(int)open->op_fname.len, open->op_fname.data,
+		open->op_openowner);
+
+	/* This check required by spec. */
+	if (open->op_create && open->op_claim_type != NFS4_OPEN_CLAIM_NULL)
+		return nfserr_inval;
+
+	open->op_created = false;
+	/*
+	 * RFC5661 18.51.3
+	 * Before RECLAIM_COMPLETE done, server should deny new lock
+	 */
+	if (nfsd4_has_session(cstate) &&
+	    !test_bit(NFSD4_CLIENT_RECLAIM_COMPLETE,
+		      &cstate->session->se_client->cl_flags) &&
+	    open->op_claim_type != NFS4_OPEN_CLAIM_PREVIOUS)
+		return nfserr_grace;
+
+	if (nfsd4_has_session(cstate))
+		copy_clientid(&open->op_clientid, cstate->session);
+
+	/* check seqid for replay. set nfs4_owner */
+	status = nfsd4_process_open1(cstate, open, nn);
+	if (status == nfserr_replay_me) {
+		struct nfs4_replay *rp = &open->op_openowner->oo_owner.so_replay;
+		fh_put(&cstate->current_fh);
+		fh_copy_shallow(&cstate->current_fh.fh_handle,
+				&rp->rp_openfh);
+		status = fh_verify(rqstp, &cstate->current_fh, 0, NFSD_MAY_NOP);
+		if (status)
+			dprintk("nfsd4_open: replay failed"
+				" restoring previous filehandle\n");
+		else
+			status = nfserr_replay_me;
+	}
+	if (status)
+		goto out;
+	if (open->op_xdr_error) {
+		status = open->op_xdr_error;
+		goto out;
+	}
+
+	status = nfsd4_check_open_attributes(rqstp, cstate, open);
+	if (status)
+		goto out;
+
+	/* Openowner is now set, so sequence id will get bumped.  Now we need
+	 * these checks before we do any creates: */
+	status = nfserr_grace;
+	if (opens_in_grace(net) && open->op_claim_type != NFS4_OPEN_CLAIM_PREVIOUS)
+		goto out;
+	status = nfserr_no_grace;
+	if (!opens_in_grace(net) && open->op_claim_type == NFS4_OPEN_CLAIM_PREVIOUS)
+		goto out;
+
+	switch (open->op_claim_type) {
+		case NFS4_OPEN_CLAIM_DELEGATE_CUR:
+		case NFS4_OPEN_CLAIM_NULL:
+			status = do_open_lookup(rqstp, cstate, open, &resfh);
+			if (status)
+				goto out;
+			break;
+		case NFS4_OPEN_CLAIM_PREVIOUS:
+			status = nfs4_check_open_reclaim(&open->op_clientid,
+							 cstate, nn);
+			if (status)
+				goto out;
+			open->op_openowner->oo_flags |= NFS4_OO_CONFIRMED;
+			reclaim = true;
+			fallthrough;
+		case NFS4_OPEN_CLAIM_FH:
+		case NFS4_OPEN_CLAIM_DELEG_CUR_FH:
+			status = do_open_fhandle(rqstp, cstate, open);
+			if (status)
+				goto out;
+			resfh = &cstate->current_fh;
+			break;
+		case NFS4_OPEN_CLAIM_DELEG_PREV_FH:
+             	case NFS4_OPEN_CLAIM_DELEGATE_PREV:
+			dprintk("NFSD: unsupported OPEN claim type %d\n",
+				open->op_claim_type);
+			status = nfserr_notsupp;
+			goto out;
+		default:
+			dprintk("NFSD: Invalid OPEN claim type %d\n",
+				open->op_claim_type);
+			status = nfserr_inval;
+			goto out;
+	}
+	/*
+	 * nfsd4_process_open2() does the actual opening of the file.  If
+	 * successful, it (1) truncates the file if open->op_truncate was
+	 * set, (2) sets open->op_stateid, (3) sets open->op_delegation.
+	 */
+	status = nfsd4_process_open2(rqstp, resfh, open);
+	WARN(status && open->op_created,
+	     "nfsd4_process_open2 failed to open newly-created file! status=%u\n",
+	     be32_to_cpu(status));
+	if (reclaim && !status)
+		nn->somebody_reclaimed = true;
+out:
+	if (resfh && resfh != &cstate->current_fh) {
+		fh_dup2(&cstate->current_fh, resfh);
+		fh_put(resfh);
+		kfree(resfh);
+	}
+	nfsd4_cleanup_open_state(cstate, open);
+	nfsd4_bump_seqid(cstate, status);
+	return status;
+}
+
+/*
+ * OPEN is the only seqid-mutating operation whose decoding can fail
+ * with a seqid-mutating error (specifically, decoding of user names in
+ * the attributes).  Therefore we have to do some processing to look up
+ * the stateowner so that we can bump the seqid.
+ */
+static __be32 nfsd4_open_omfg(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, struct nfsd4_op *op)
+{
+	struct nfsd4_open *open = &op->u.open;
+
+	if (!seqid_mutating_err(ntohl(op->status)))
+		return op->status;
+	if (nfsd4_has_session(cstate))
+		return op->status;
+	open->op_xdr_error = op->status;
+	return nfsd4_open(rqstp, cstate, &op->u);
+}
+
+/*
+ * filehandle-manipulating ops.
+ */
+static __be32
+nfsd4_getfh(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+	    union nfsd4_op_u *u)
+{
+	u->getfh = &cstate->current_fh;
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_putfh(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+	    union nfsd4_op_u *u)
+{
+	struct nfsd4_putfh *putfh = &u->putfh;
+	__be32 ret;
+
+	fh_put(&cstate->current_fh);
+	cstate->current_fh.fh_handle.fh_size = putfh->pf_fhlen;
+	memcpy(&cstate->current_fh.fh_handle.fh_base, putfh->pf_fhval,
+	       putfh->pf_fhlen);
+	ret = fh_verify(rqstp, &cstate->current_fh, 0, NFSD_MAY_BYPASS_GSS);
+#ifdef CONFIG_NFSD_V4_2_INTER_SSC
+	if (ret == nfserr_stale && putfh->no_verify) {
+		SET_FH_FLAG(&cstate->current_fh, NFSD4_FH_FOREIGN);
+		ret = 0;
+	}
+#endif
+	return ret;
+}
+
+static __be32
+nfsd4_putrootfh(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+		union nfsd4_op_u *u)
+{
+	__be32 status;
+
+	fh_put(&cstate->current_fh);
+	status = exp_pseudoroot(rqstp, &cstate->current_fh);
+	return status;
+}
+
+static __be32
+nfsd4_restorefh(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+		union nfsd4_op_u *u)
+{
+	if (!cstate->save_fh.fh_dentry)
+		return nfserr_restorefh;
+
+	fh_dup2(&cstate->current_fh, &cstate->save_fh);
+	if (HAS_CSTATE_FLAG(cstate, SAVED_STATE_ID_FLAG)) {
+		memcpy(&cstate->current_stateid, &cstate->save_stateid, sizeof(stateid_t));
+		SET_CSTATE_FLAG(cstate, CURRENT_STATE_ID_FLAG);
+	}
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_savefh(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+	     union nfsd4_op_u *u)
+{
+	fh_dup2(&cstate->save_fh, &cstate->current_fh);
+	if (HAS_CSTATE_FLAG(cstate, CURRENT_STATE_ID_FLAG)) {
+		memcpy(&cstate->save_stateid, &cstate->current_stateid, sizeof(stateid_t));
+		SET_CSTATE_FLAG(cstate, SAVED_STATE_ID_FLAG);
+	}
+	return nfs_ok;
+}
+
+/*
+ * misc nfsv4 ops
+ */
+static __be32
+nfsd4_access(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+	     union nfsd4_op_u *u)
+{
+	struct nfsd4_access *access = &u->access;
+	u32 access_full;
+
+	access_full = NFS3_ACCESS_FULL;
+	if (cstate->minorversion >= 2)
+		access_full |= NFS4_ACCESS_XALIST | NFS4_ACCESS_XAREAD |
+			       NFS4_ACCESS_XAWRITE;
+
+	if (access->ac_req_access & ~access_full)
+		return nfserr_inval;
+
+	access->ac_resp_access = access->ac_req_access;
+	return nfsd_access(rqstp, &cstate->current_fh, &access->ac_resp_access,
+			   &access->ac_supported);
+}
+
+static void gen_boot_verifier(nfs4_verifier *verifier, struct net *net)
+{
+	__be32 *verf = (__be32 *)verifier->data;
+
+	BUILD_BUG_ON(2*sizeof(*verf) != sizeof(verifier->data));
+
+	nfsd_copy_boot_verifier(verf, net_generic(net, nfsd_net_id));
+}
+
+static __be32
+nfsd4_commit(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+	     union nfsd4_op_u *u)
+{
+	struct nfsd4_commit *commit = &u->commit;
+
+	return nfsd_commit(rqstp, &cstate->current_fh, commit->co_offset,
+			     commit->co_count,
+			     (__be32 *)commit->co_verf.data);
+}
+
+static __be32
+nfsd4_create(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+	     union nfsd4_op_u *u)
+{
+	struct nfsd4_create *create = &u->create;
+	struct svc_fh resfh;
+	__be32 status;
+	dev_t rdev;
+
+	fh_init(&resfh, NFS4_FHSIZE);
+
+	status = fh_verify(rqstp, &cstate->current_fh, S_IFDIR, NFSD_MAY_NOP);
+	if (status)
+		return status;
+
+	status = check_attr_support(rqstp, cstate, create->cr_bmval,
+				    nfsd_attrmask);
+	if (status)
+		return status;
+
+	current->fs->umask = create->cr_umask;
+	switch (create->cr_type) {
+	case NF4LNK:
+		status = nfsd_symlink(rqstp, &cstate->current_fh,
+				      create->cr_name, create->cr_namelen,
+				      create->cr_data, &resfh);
+		break;
+
+	case NF4BLK:
+		status = nfserr_inval;
+		rdev = MKDEV(create->cr_specdata1, create->cr_specdata2);
+		if (MAJOR(rdev) != create->cr_specdata1 ||
+		    MINOR(rdev) != create->cr_specdata2)
+			goto out_umask;
+		status = nfsd_create(rqstp, &cstate->current_fh,
+				     create->cr_name, create->cr_namelen,
+				     &create->cr_iattr, S_IFBLK, rdev, &resfh);
+		break;
+
+	case NF4CHR:
+		status = nfserr_inval;
+		rdev = MKDEV(create->cr_specdata1, create->cr_specdata2);
+		if (MAJOR(rdev) != create->cr_specdata1 ||
+		    MINOR(rdev) != create->cr_specdata2)
+			goto out_umask;
+		status = nfsd_create(rqstp, &cstate->current_fh,
+				     create->cr_name, create->cr_namelen,
+				     &create->cr_iattr,S_IFCHR, rdev, &resfh);
+		break;
+
+	case NF4SOCK:
+		status = nfsd_create(rqstp, &cstate->current_fh,
+				     create->cr_name, create->cr_namelen,
+				     &create->cr_iattr, S_IFSOCK, 0, &resfh);
+		break;
+
+	case NF4FIFO:
+		status = nfsd_create(rqstp, &cstate->current_fh,
+				     create->cr_name, create->cr_namelen,
+				     &create->cr_iattr, S_IFIFO, 0, &resfh);
+		break;
+
+	case NF4DIR:
+		create->cr_iattr.ia_valid &= ~ATTR_SIZE;
+		status = nfsd_create(rqstp, &cstate->current_fh,
+				     create->cr_name, create->cr_namelen,
+				     &create->cr_iattr, S_IFDIR, 0, &resfh);
+		break;
+
+	default:
+		status = nfserr_badtype;
+	}
+
+	if (status)
+		goto out;
+
+	if (create->cr_label.len)
+		nfsd4_security_inode_setsecctx(&resfh, &create->cr_label, create->cr_bmval);
+
+	if (create->cr_acl != NULL)
+		do_set_nfs4_acl(rqstp, &resfh, create->cr_acl,
+				create->cr_bmval);
+
+	fh_unlock(&cstate->current_fh);
+	set_change_info(&create->cr_cinfo, &cstate->current_fh);
+	fh_dup2(&cstate->current_fh, &resfh);
+out:
+	fh_put(&resfh);
+out_umask:
+	current->fs->umask = 0;
+	return status;
+}
+
+static __be32
+nfsd4_getattr(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+	      union nfsd4_op_u *u)
+{
+	struct nfsd4_getattr *getattr = &u->getattr;
+	__be32 status;
+
+	status = fh_verify(rqstp, &cstate->current_fh, 0, NFSD_MAY_NOP);
+	if (status)
+		return status;
+
+	if (getattr->ga_bmval[1] & NFSD_WRITEONLY_ATTRS_WORD1)
+		return nfserr_inval;
+
+	getattr->ga_bmval[0] &= nfsd_suppattrs[cstate->minorversion][0];
+	getattr->ga_bmval[1] &= nfsd_suppattrs[cstate->minorversion][1];
+	getattr->ga_bmval[2] &= nfsd_suppattrs[cstate->minorversion][2];
+
+	getattr->ga_fhp = &cstate->current_fh;
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_link(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+	   union nfsd4_op_u *u)
+{
+	struct nfsd4_link *link = &u->link;
+	__be32 status;
+
+	status = nfsd_link(rqstp, &cstate->current_fh,
+			   link->li_name, link->li_namelen, &cstate->save_fh);
+	if (!status)
+		set_change_info(&link->li_cinfo, &cstate->current_fh);
+	return status;
+}
+
+static __be32 nfsd4_do_lookupp(struct svc_rqst *rqstp, struct svc_fh *fh)
+{
+	struct svc_fh tmp_fh;
+	__be32 ret;
+
+	fh_init(&tmp_fh, NFS4_FHSIZE);
+	ret = exp_pseudoroot(rqstp, &tmp_fh);
+	if (ret)
+		return ret;
+	if (tmp_fh.fh_dentry == fh->fh_dentry) {
+		fh_put(&tmp_fh);
+		return nfserr_noent;
+	}
+	fh_put(&tmp_fh);
+	return nfsd_lookup(rqstp, fh, "..", 2, fh);
+}
+
+static __be32
+nfsd4_lookupp(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+	      union nfsd4_op_u *u)
+{
+	return nfsd4_do_lookupp(rqstp, &cstate->current_fh);
+}
+
+static __be32
+nfsd4_lookup(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+	     union nfsd4_op_u *u)
+{
+	return nfsd_lookup(rqstp, &cstate->current_fh,
+			   u->lookup.lo_name, u->lookup.lo_len,
+			   &cstate->current_fh);
+}
+
+static __be32
+nfsd4_read(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+	   union nfsd4_op_u *u)
+{
+	struct nfsd4_read *read = &u->read;
+	__be32 status;
+
+	read->rd_nf = NULL;
+	if (read->rd_offset >= OFFSET_MAX)
+		return nfserr_inval;
+
+	trace_nfsd_read_start(rqstp, &cstate->current_fh,
+			      read->rd_offset, read->rd_length);
+
+	/*
+	 * If we do a zero copy read, then a client will see read data
+	 * that reflects the state of the file *after* performing the
+	 * following compound.
+	 *
+	 * To ensure proper ordering, we therefore turn off zero copy if
+	 * the client wants us to do more in this compound:
+	 */
+	if (!nfsd4_last_compound_op(rqstp))
+		clear_bit(RQ_SPLICE_OK, &rqstp->rq_flags);
+
+	/* check stateid */
+	status = nfs4_preprocess_stateid_op(rqstp, cstate, &cstate->current_fh,
+					&read->rd_stateid, RD_STATE,
+					&read->rd_nf, NULL);
+	if (status) {
+		dprintk("NFSD: nfsd4_read: couldn't process stateid!\n");
+		goto out;
+	}
+	status = nfs_ok;
+out:
+	read->rd_rqstp = rqstp;
+	read->rd_fhp = &cstate->current_fh;
+	return status;
+}
+
+
+static void
+nfsd4_read_release(union nfsd4_op_u *u)
+{
+	if (u->read.rd_nf)
+		nfsd_file_put(u->read.rd_nf);
+	trace_nfsd_read_done(u->read.rd_rqstp, u->read.rd_fhp,
+			     u->read.rd_offset, u->read.rd_length);
+}
+
+static __be32
+nfsd4_readdir(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+	      union nfsd4_op_u *u)
+{
+	struct nfsd4_readdir *readdir = &u->readdir;
+	u64 cookie = readdir->rd_cookie;
+	static const nfs4_verifier zeroverf;
+
+	/* no need to check permission - this will be done in nfsd_readdir() */
+
+	if (readdir->rd_bmval[1] & NFSD_WRITEONLY_ATTRS_WORD1)
+		return nfserr_inval;
+
+	readdir->rd_bmval[0] &= nfsd_suppattrs[cstate->minorversion][0];
+	readdir->rd_bmval[1] &= nfsd_suppattrs[cstate->minorversion][1];
+	readdir->rd_bmval[2] &= nfsd_suppattrs[cstate->minorversion][2];
+
+	if ((cookie == 1) || (cookie == 2) ||
+	    (cookie == 0 && memcmp(readdir->rd_verf.data, zeroverf.data, NFS4_VERIFIER_SIZE)))
+		return nfserr_bad_cookie;
+
+	readdir->rd_rqstp = rqstp;
+	readdir->rd_fhp = &cstate->current_fh;
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_readlink(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+	       union nfsd4_op_u *u)
+{
+	u->readlink.rl_rqstp = rqstp;
+	u->readlink.rl_fhp = &cstate->current_fh;
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_remove(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+	     union nfsd4_op_u *u)
+{
+	struct nfsd4_remove *remove = &u->remove;
+	__be32 status;
+
+	if (opens_in_grace(SVC_NET(rqstp)))
+		return nfserr_grace;
+	status = nfsd_unlink(rqstp, &cstate->current_fh, 0,
+			     remove->rm_name, remove->rm_namelen);
+	if (!status) {
+		fh_unlock(&cstate->current_fh);
+		set_change_info(&remove->rm_cinfo, &cstate->current_fh);
+	}
+	return status;
+}
+
+static __be32
+nfsd4_rename(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+	     union nfsd4_op_u *u)
+{
+	struct nfsd4_rename *rename = &u->rename;
+	__be32 status;
+
+	if (opens_in_grace(SVC_NET(rqstp)))
+		return nfserr_grace;
+	status = nfsd_rename(rqstp, &cstate->save_fh, rename->rn_sname,
+			     rename->rn_snamelen, &cstate->current_fh,
+			     rename->rn_tname, rename->rn_tnamelen);
+	if (status)
+		return status;
+	set_change_info(&rename->rn_sinfo, &cstate->save_fh);
+	set_change_info(&rename->rn_tinfo, &cstate->current_fh);
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_secinfo(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+	      union nfsd4_op_u *u)
+{
+	struct nfsd4_secinfo *secinfo = &u->secinfo;
+	struct svc_export *exp;
+	struct dentry *dentry;
+	__be32 err;
+
+	err = fh_verify(rqstp, &cstate->current_fh, S_IFDIR, NFSD_MAY_EXEC);
+	if (err)
+		return err;
+	err = nfsd_lookup_dentry(rqstp, &cstate->current_fh,
+				    secinfo->si_name, secinfo->si_namelen,
+				    &exp, &dentry);
+	if (err)
+		return err;
+	fh_unlock(&cstate->current_fh);
+	if (d_really_is_negative(dentry)) {
+		exp_put(exp);
+		err = nfserr_noent;
+	} else
+		secinfo->si_exp = exp;
+	dput(dentry);
+	if (cstate->minorversion)
+		/* See rfc 5661 section 2.6.3.1.1.8 */
+		fh_put(&cstate->current_fh);
+	return err;
+}
+
+static __be32
+nfsd4_secinfo_no_name(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+		union nfsd4_op_u *u)
+{
+	__be32 err;
+
+	switch (u->secinfo_no_name.sin_style) {
+	case NFS4_SECINFO_STYLE4_CURRENT_FH:
+		break;
+	case NFS4_SECINFO_STYLE4_PARENT:
+		err = nfsd4_do_lookupp(rqstp, &cstate->current_fh);
+		if (err)
+			return err;
+		break;
+	default:
+		return nfserr_inval;
+	}
+
+	u->secinfo_no_name.sin_exp = exp_get(cstate->current_fh.fh_export);
+	fh_put(&cstate->current_fh);
+	return nfs_ok;
+}
+
+static void
+nfsd4_secinfo_release(union nfsd4_op_u *u)
+{
+	if (u->secinfo.si_exp)
+		exp_put(u->secinfo.si_exp);
+}
+
+static void
+nfsd4_secinfo_no_name_release(union nfsd4_op_u *u)
+{
+	if (u->secinfo_no_name.sin_exp)
+		exp_put(u->secinfo_no_name.sin_exp);
+}
+
+static __be32
+nfsd4_setattr(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+	      union nfsd4_op_u *u)
+{
+	struct nfsd4_setattr *setattr = &u->setattr;
+	__be32 status = nfs_ok;
+	int err;
+
+	if (setattr->sa_iattr.ia_valid & ATTR_SIZE) {
+		status = nfs4_preprocess_stateid_op(rqstp, cstate,
+				&cstate->current_fh, &setattr->sa_stateid,
+				WR_STATE, NULL, NULL);
+		if (status) {
+			dprintk("NFSD: nfsd4_setattr: couldn't process stateid!\n");
+			return status;
+		}
+	}
+	err = fh_want_write(&cstate->current_fh);
+	if (err)
+		return nfserrno(err);
+	status = nfs_ok;
+
+	status = check_attr_support(rqstp, cstate, setattr->sa_bmval,
+				    nfsd_attrmask);
+	if (status)
+		goto out;
+
+	if (setattr->sa_acl != NULL)
+		status = nfsd4_set_nfs4_acl(rqstp, &cstate->current_fh,
+					    setattr->sa_acl);
+	if (status)
+		goto out;
+	if (setattr->sa_label.len)
+		status = nfsd4_set_nfs4_label(rqstp, &cstate->current_fh,
+				&setattr->sa_label);
+	if (status)
+		goto out;
+	status = nfsd_setattr(rqstp, &cstate->current_fh, &setattr->sa_iattr,
+				0, (time64_t)0);
+out:
+	fh_drop_write(&cstate->current_fh);
+	return status;
+}
+
+static __be32
+nfsd4_write(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+	    union nfsd4_op_u *u)
+{
+	struct nfsd4_write *write = &u->write;
+	stateid_t *stateid = &write->wr_stateid;
+	struct nfsd_file *nf = NULL;
+	__be32 status = nfs_ok;
+	unsigned long cnt;
+	int nvecs;
+
+	if (write->wr_offset > (u64)OFFSET_MAX ||
+	    write->wr_offset + write->wr_buflen > (u64)OFFSET_MAX)
+		return nfserr_fbig;
+
+	cnt = write->wr_buflen;
+	trace_nfsd_write_start(rqstp, &cstate->current_fh,
+			       write->wr_offset, cnt);
+	status = nfs4_preprocess_stateid_op(rqstp, cstate, &cstate->current_fh,
+						stateid, WR_STATE, &nf, NULL);
+	if (status) {
+		dprintk("NFSD: nfsd4_write: couldn't process stateid!\n");
+		return status;
+	}
+
+	write->wr_how_written = write->wr_stable_how;
+
+	nvecs = svc_fill_write_vector(rqstp, write->wr_pagelist,
+				      &write->wr_head, write->wr_buflen);
+	WARN_ON_ONCE(nvecs > ARRAY_SIZE(rqstp->rq_vec));
+
+	status = nfsd_vfs_write(rqstp, &cstate->current_fh, nf,
+				write->wr_offset, rqstp->rq_vec, nvecs, &cnt,
+				write->wr_how_written,
+				(__be32 *)write->wr_verifier.data);
+	nfsd_file_put(nf);
+
+	write->wr_bytes_written = cnt;
+	trace_nfsd_write_done(rqstp, &cstate->current_fh,
+			      write->wr_offset, cnt);
+	return status;
+}
+
+static __be32
+nfsd4_verify_copy(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+		  stateid_t *src_stateid, struct nfsd_file **src,
+		  stateid_t *dst_stateid, struct nfsd_file **dst)
+{
+	__be32 status;
+
+	if (!cstate->save_fh.fh_dentry)
+		return nfserr_nofilehandle;
+
+	status = nfs4_preprocess_stateid_op(rqstp, cstate, &cstate->save_fh,
+					    src_stateid, RD_STATE, src, NULL);
+	if (status) {
+		dprintk("NFSD: %s: couldn't process src stateid!\n", __func__);
+		goto out;
+	}
+
+	status = nfs4_preprocess_stateid_op(rqstp, cstate, &cstate->current_fh,
+					    dst_stateid, WR_STATE, dst, NULL);
+	if (status) {
+		dprintk("NFSD: %s: couldn't process dst stateid!\n", __func__);
+		goto out_put_src;
+	}
+
+	/* fix up for NFS-specific error code */
+	if (!S_ISREG(file_inode((*src)->nf_file)->i_mode) ||
+	    !S_ISREG(file_inode((*dst)->nf_file)->i_mode)) {
+		status = nfserr_wrong_type;
+		goto out_put_dst;
+	}
+
+out:
+	return status;
+out_put_dst:
+	nfsd_file_put(*dst);
+	*dst = NULL;
+out_put_src:
+	nfsd_file_put(*src);
+	*src = NULL;
+	goto out;
+}
+
+static __be32
+nfsd4_clone(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+		union nfsd4_op_u *u)
+{
+	struct nfsd4_clone *clone = &u->clone;
+	struct nfsd_file *src, *dst;
+	__be32 status;
+
+	status = nfsd4_verify_copy(rqstp, cstate, &clone->cl_src_stateid, &src,
+				   &clone->cl_dst_stateid, &dst);
+	if (status)
+		goto out;
+
+	status = nfsd4_clone_file_range(src, clone->cl_src_pos,
+			dst, clone->cl_dst_pos, clone->cl_count,
+			EX_ISSYNC(cstate->current_fh.fh_export));
+
+	nfsd_file_put(dst);
+	nfsd_file_put(src);
+out:
+	return status;
+}
+
+void nfs4_put_copy(struct nfsd4_copy *copy)
+{
+	if (!refcount_dec_and_test(&copy->refcount))
+		return;
+	kfree(copy);
+}
+
+static bool
+check_and_set_stop_copy(struct nfsd4_copy *copy)
+{
+	bool value;
+
+	spin_lock(&copy->cp_clp->async_lock);
+	value = copy->stopped;
+	if (!copy->stopped)
+		copy->stopped = true;
+	spin_unlock(&copy->cp_clp->async_lock);
+	return value;
+}
+
+static void nfsd4_stop_copy(struct nfsd4_copy *copy)
+{
+	/* only 1 thread should stop the copy */
+	if (!check_and_set_stop_copy(copy))
+		kthread_stop(copy->copy_task);
+	nfs4_put_copy(copy);
+}
+
+static struct nfsd4_copy *nfsd4_get_copy(struct nfs4_client *clp)
+{
+	struct nfsd4_copy *copy = NULL;
+
+	spin_lock(&clp->async_lock);
+	if (!list_empty(&clp->async_copies)) {
+		copy = list_first_entry(&clp->async_copies, struct nfsd4_copy,
+					copies);
+		refcount_inc(&copy->refcount);
+	}
+	spin_unlock(&clp->async_lock);
+	return copy;
+}
+
+void nfsd4_shutdown_copy(struct nfs4_client *clp)
+{
+	struct nfsd4_copy *copy;
+
+	while ((copy = nfsd4_get_copy(clp)) != NULL)
+		nfsd4_stop_copy(copy);
+}
+#ifdef CONFIG_NFSD_V4_2_INTER_SSC
+
+extern struct file *nfs42_ssc_open(struct vfsmount *ss_mnt,
+				   struct nfs_fh *src_fh,
+				   nfs4_stateid *stateid);
+extern void nfs42_ssc_close(struct file *filep);
+
+extern void nfs_sb_deactive(struct super_block *sb);
+
+#define NFSD42_INTERSSC_MOUNTOPS "vers=4.2,addr=%s,sec=sys"
+
+/*
+ * Support one copy source server for now.
+ */
+static __be32
+nfsd4_interssc_connect(struct nl4_server *nss, struct svc_rqst *rqstp,
+		       struct vfsmount **mount)
+{
+	struct file_system_type *type;
+	struct vfsmount *ss_mnt;
+	struct nfs42_netaddr *naddr;
+	struct sockaddr_storage tmp_addr;
+	size_t tmp_addrlen, match_netid_len = 3;
+	char *startsep = "", *endsep = "", *match_netid = "tcp";
+	char *ipaddr, *dev_name, *raw_data;
+	int len, raw_len;
+	__be32 status = nfserr_inval;
+
+	naddr = &nss->u.nl4_addr;
+	tmp_addrlen = rpc_uaddr2sockaddr(SVC_NET(rqstp), naddr->addr,
+					 naddr->addr_len,
+					 (struct sockaddr *)&tmp_addr,
+					 sizeof(tmp_addr));
+	if (tmp_addrlen == 0)
+		goto out_err;
+
+	if (tmp_addr.ss_family == AF_INET6) {
+		startsep = "[";
+		endsep = "]";
+		match_netid = "tcp6";
+		match_netid_len = 4;
+	}
+
+	if (naddr->netid_len != match_netid_len ||
+		strncmp(naddr->netid, match_netid, naddr->netid_len))
+		goto out_err;
+
+	/* Construct the raw data for the vfs_kern_mount call */
+	len = RPC_MAX_ADDRBUFLEN + 1;
+	ipaddr = kzalloc(len, GFP_KERNEL);
+	if (!ipaddr)
+		goto out_err;
+
+	rpc_ntop((struct sockaddr *)&tmp_addr, ipaddr, len);
+
+	/* 2 for ipv6 endsep and startsep. 3 for ":/" and trailing '/0'*/
+
+	raw_len = strlen(NFSD42_INTERSSC_MOUNTOPS) + strlen(ipaddr);
+	raw_data = kzalloc(raw_len, GFP_KERNEL);
+	if (!raw_data)
+		goto out_free_ipaddr;
+
+	snprintf(raw_data, raw_len, NFSD42_INTERSSC_MOUNTOPS, ipaddr);
+
+	status = nfserr_nodev;
+	type = get_fs_type("nfs");
+	if (!type)
+		goto out_free_rawdata;
+
+	/* Set the server:<export> for the vfs_kern_mount call */
+	dev_name = kzalloc(len + 5, GFP_KERNEL);
+	if (!dev_name)
+		goto out_free_rawdata;
+	snprintf(dev_name, len + 5, "%s%s%s:/", startsep, ipaddr, endsep);
+
+	/* Use an 'internal' mount: SB_KERNMOUNT -> MNT_INTERNAL */
+	ss_mnt = vfs_kern_mount(type, SB_KERNMOUNT, dev_name, raw_data);
+	module_put(type->owner);
+	if (IS_ERR(ss_mnt))
+		goto out_free_devname;
+
+	status = 0;
+	*mount = ss_mnt;
+
+out_free_devname:
+	kfree(dev_name);
+out_free_rawdata:
+	kfree(raw_data);
+out_free_ipaddr:
+	kfree(ipaddr);
+out_err:
+	return status;
+}
+
+/*
+ * Verify COPY destination stateid.
+ *
+ * Connect to the source server with NFSv4.1.
+ * Create the source struct file for nfsd_copy_range.
+ * Called with COPY cstate:
+ *    SAVED_FH: source filehandle
+ *    CURRENT_FH: destination filehandle
+ */
+static __be32
+nfsd4_setup_inter_ssc(struct svc_rqst *rqstp,
+		      struct nfsd4_compound_state *cstate,
+		      struct nfsd4_copy *copy, struct vfsmount **mount)
+{
+	struct svc_fh *s_fh = NULL;
+	stateid_t *s_stid = &copy->cp_src_stateid;
+	__be32 status = nfserr_inval;
+
+	/* Verify the destination stateid and set dst struct file*/
+	status = nfs4_preprocess_stateid_op(rqstp, cstate, &cstate->current_fh,
+					    &copy->cp_dst_stateid,
+					    WR_STATE, &copy->nf_dst, NULL);
+	if (status)
+		goto out;
+
+	status = nfsd4_interssc_connect(&copy->cp_src, rqstp, mount);
+	if (status)
+		goto out;
+
+	s_fh = &cstate->save_fh;
+
+	copy->c_fh.size = s_fh->fh_handle.fh_size;
+	memcpy(copy->c_fh.data, &s_fh->fh_handle.fh_base, copy->c_fh.size);
+	copy->stateid.seqid = cpu_to_be32(s_stid->si_generation);
+	memcpy(copy->stateid.other, (void *)&s_stid->si_opaque,
+	       sizeof(stateid_opaque_t));
+
+	status = 0;
+out:
+	return status;
+}
+
+static void
+nfsd4_cleanup_inter_ssc(struct vfsmount *ss_mnt, struct nfsd_file *src,
+			struct nfsd_file *dst)
+{
+	nfs42_ssc_close(src->nf_file);
+	fput(src->nf_file);
+	nfsd_file_put(dst);
+	mntput(ss_mnt);
+}
+
+#else /* CONFIG_NFSD_V4_2_INTER_SSC */
+
+static __be32
+nfsd4_setup_inter_ssc(struct svc_rqst *rqstp,
+		      struct nfsd4_compound_state *cstate,
+		      struct nfsd4_copy *copy,
+		      struct vfsmount **mount)
+{
+	*mount = NULL;
+	return nfserr_inval;
+}
+
+static void
+nfsd4_cleanup_inter_ssc(struct vfsmount *ss_mnt, struct nfsd_file *src,
+			struct nfsd_file *dst)
+{
+}
+
+static struct file *nfs42_ssc_open(struct vfsmount *ss_mnt,
+				   struct nfs_fh *src_fh,
+				   nfs4_stateid *stateid)
+{
+	return NULL;
+}
+#endif /* CONFIG_NFSD_V4_2_INTER_SSC */
+
+static __be32
+nfsd4_setup_intra_ssc(struct svc_rqst *rqstp,
+		      struct nfsd4_compound_state *cstate,
+		      struct nfsd4_copy *copy)
+{
+	return nfsd4_verify_copy(rqstp, cstate, &copy->cp_src_stateid,
+				 &copy->nf_src, &copy->cp_dst_stateid,
+				 &copy->nf_dst);
+}
+
+static void
+nfsd4_cleanup_intra_ssc(struct nfsd_file *src, struct nfsd_file *dst)
+{
+	nfsd_file_put(src);
+	nfsd_file_put(dst);
+}
+
+static void nfsd4_cb_offload_release(struct nfsd4_callback *cb)
+{
+	struct nfsd4_copy *copy = container_of(cb, struct nfsd4_copy, cp_cb);
+
+	nfs4_put_copy(copy);
+}
+
+static int nfsd4_cb_offload_done(struct nfsd4_callback *cb,
+				 struct rpc_task *task)
+{
+	return 1;
+}
+
+static const struct nfsd4_callback_ops nfsd4_cb_offload_ops = {
+	.release = nfsd4_cb_offload_release,
+	.done = nfsd4_cb_offload_done
+};
+
+static void nfsd4_init_copy_res(struct nfsd4_copy *copy, bool sync)
+{
+	copy->cp_res.wr_stable_how = NFS_UNSTABLE;
+	copy->cp_synchronous = sync;
+	gen_boot_verifier(&copy->cp_res.wr_verifier, copy->cp_clp->net);
+}
+
+static ssize_t _nfsd_copy_file_range(struct nfsd4_copy *copy)
+{
+	struct file *dst = copy->nf_dst->nf_file;
+	struct file *src = copy->nf_src->nf_file;
+	ssize_t bytes_copied = 0;
+	size_t bytes_total = copy->cp_count;
+	u64 src_pos = copy->cp_src_pos;
+	u64 dst_pos = copy->cp_dst_pos;
+
+	do {
+		if (kthread_should_stop())
+			break;
+		bytes_copied = nfsd_copy_file_range(src, src_pos, dst, dst_pos,
+						    bytes_total);
+		if (bytes_copied <= 0)
+			break;
+		bytes_total -= bytes_copied;
+		copy->cp_res.wr_bytes_written += bytes_copied;
+		src_pos += bytes_copied;
+		dst_pos += bytes_copied;
+	} while (bytes_total > 0 && !copy->cp_synchronous);
+	return bytes_copied;
+}
+
+static __be32 nfsd4_do_copy(struct nfsd4_copy *copy, bool sync)
+{
+	__be32 status;
+	ssize_t bytes;
+
+	bytes = _nfsd_copy_file_range(copy);
+	/* for async copy, we ignore the error, client can always retry
+	 * to get the error
+	 */
+	if (bytes < 0 && !copy->cp_res.wr_bytes_written)
+		status = nfserrno(bytes);
+	else {
+		nfsd4_init_copy_res(copy, sync);
+		status = nfs_ok;
+	}
+
+	if (!copy->cp_intra) /* Inter server SSC */
+		nfsd4_cleanup_inter_ssc(copy->ss_mnt, copy->nf_src,
+					copy->nf_dst);
+	else
+		nfsd4_cleanup_intra_ssc(copy->nf_src, copy->nf_dst);
+
+	return status;
+}
+
+static void dup_copy_fields(struct nfsd4_copy *src, struct nfsd4_copy *dst)
+{
+	dst->cp_src_pos = src->cp_src_pos;
+	dst->cp_dst_pos = src->cp_dst_pos;
+	dst->cp_count = src->cp_count;
+	dst->cp_synchronous = src->cp_synchronous;
+	memcpy(&dst->cp_res, &src->cp_res, sizeof(src->cp_res));
+	memcpy(&dst->fh, &src->fh, sizeof(src->fh));
+	dst->cp_clp = src->cp_clp;
+	dst->nf_dst = nfsd_file_get(src->nf_dst);
+	dst->cp_intra = src->cp_intra;
+	if (src->cp_intra) /* for inter, file_src doesn't exist yet */
+		dst->nf_src = nfsd_file_get(src->nf_src);
+
+	memcpy(&dst->cp_stateid, &src->cp_stateid, sizeof(src->cp_stateid));
+	memcpy(&dst->cp_src, &src->cp_src, sizeof(struct nl4_server));
+	memcpy(&dst->stateid, &src->stateid, sizeof(src->stateid));
+	memcpy(&dst->c_fh, &src->c_fh, sizeof(src->c_fh));
+	dst->ss_mnt = src->ss_mnt;
+}
+
+static void cleanup_async_copy(struct nfsd4_copy *copy)
+{
+	nfs4_free_copy_state(copy);
+	nfsd_file_put(copy->nf_dst);
+	if (copy->cp_intra)
+		nfsd_file_put(copy->nf_src);
+	spin_lock(&copy->cp_clp->async_lock);
+	list_del(&copy->copies);
+	spin_unlock(&copy->cp_clp->async_lock);
+	nfs4_put_copy(copy);
+}
+
+static int nfsd4_do_async_copy(void *data)
+{
+	struct nfsd4_copy *copy = (struct nfsd4_copy *)data;
+	struct nfsd4_copy *cb_copy;
+
+	if (!copy->cp_intra) { /* Inter server SSC */
+		copy->nf_src = kzalloc(sizeof(struct nfsd_file), GFP_KERNEL);
+		if (!copy->nf_src) {
+			copy->nfserr = nfserr_serverfault;
+			/* ss_mnt will be unmounted by the laundromat */
+			goto do_callback;
+		}
+		copy->nf_src->nf_file = nfs42_ssc_open(copy->ss_mnt, &copy->c_fh,
+					      &copy->stateid);
+		if (IS_ERR(copy->nf_src->nf_file)) {
+			copy->nfserr = nfserr_offload_denied;
+			/* ss_mnt will be unmounted by the laundromat */
+			goto do_callback;
+		}
+	}
+
+	copy->nfserr = nfsd4_do_copy(copy, 0);
+do_callback:
+	cb_copy = kzalloc(sizeof(struct nfsd4_copy), GFP_KERNEL);
+	if (!cb_copy)
+		goto out;
+	refcount_set(&cb_copy->refcount, 1);
+	memcpy(&cb_copy->cp_res, &copy->cp_res, sizeof(copy->cp_res));
+	cb_copy->cp_clp = copy->cp_clp;
+	cb_copy->nfserr = copy->nfserr;
+	memcpy(&cb_copy->fh, &copy->fh, sizeof(copy->fh));
+	nfsd4_init_cb(&cb_copy->cp_cb, cb_copy->cp_clp,
+			&nfsd4_cb_offload_ops, NFSPROC4_CLNT_CB_OFFLOAD);
+	nfsd4_run_cb(&cb_copy->cp_cb);
+out:
+	if (!copy->cp_intra)
+		kfree(copy->nf_src);
+	cleanup_async_copy(copy);
+	return 0;
+}
+
+static __be32
+nfsd4_copy(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+		union nfsd4_op_u *u)
+{
+	struct nfsd4_copy *copy = &u->copy;
+	__be32 status;
+	struct nfsd4_copy *async_copy = NULL;
+
+	if (!copy->cp_intra) { /* Inter server SSC */
+		if (!inter_copy_offload_enable || copy->cp_synchronous) {
+			status = nfserr_notsupp;
+			goto out;
+		}
+		status = nfsd4_setup_inter_ssc(rqstp, cstate, copy,
+				&copy->ss_mnt);
+		if (status)
+			return nfserr_offload_denied;
+	} else {
+		status = nfsd4_setup_intra_ssc(rqstp, cstate, copy);
+		if (status)
+			return status;
+	}
+
+	copy->cp_clp = cstate->clp;
+	memcpy(&copy->fh, &cstate->current_fh.fh_handle,
+		sizeof(struct knfsd_fh));
+	if (!copy->cp_synchronous) {
+		struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+
+		status = nfserrno(-ENOMEM);
+		async_copy = kzalloc(sizeof(struct nfsd4_copy), GFP_KERNEL);
+		if (!async_copy)
+			goto out_err;
+		if (!nfs4_init_copy_state(nn, copy))
+			goto out_err;
+		refcount_set(&async_copy->refcount, 1);
+		memcpy(&copy->cp_res.cb_stateid, &copy->cp_stateid.stid,
+			sizeof(copy->cp_res.cb_stateid));
+		dup_copy_fields(copy, async_copy);
+		async_copy->copy_task = kthread_create(nfsd4_do_async_copy,
+				async_copy, "%s", "copy thread");
+		if (IS_ERR(async_copy->copy_task))
+			goto out_err;
+		spin_lock(&async_copy->cp_clp->async_lock);
+		list_add(&async_copy->copies,
+				&async_copy->cp_clp->async_copies);
+		spin_unlock(&async_copy->cp_clp->async_lock);
+		wake_up_process(async_copy->copy_task);
+		status = nfs_ok;
+	} else {
+		status = nfsd4_do_copy(copy, 1);
+	}
+out:
+	return status;
+out_err:
+	if (async_copy)
+		cleanup_async_copy(async_copy);
+	status = nfserrno(-ENOMEM);
+	/*
+	 * source's vfsmount of inter-copy will be unmounted
+	 * by the laundromat
+	 */
+	goto out;
+}
+
+struct nfsd4_copy *
+find_async_copy(struct nfs4_client *clp, stateid_t *stateid)
+{
+	struct nfsd4_copy *copy;
+
+	spin_lock(&clp->async_lock);
+	list_for_each_entry(copy, &clp->async_copies, copies) {
+		if (memcmp(&copy->cp_stateid.stid, stateid, NFS4_STATEID_SIZE))
+			continue;
+		refcount_inc(&copy->refcount);
+		spin_unlock(&clp->async_lock);
+		return copy;
+	}
+	spin_unlock(&clp->async_lock);
+	return NULL;
+}
+
+static __be32
+nfsd4_offload_cancel(struct svc_rqst *rqstp,
+		     struct nfsd4_compound_state *cstate,
+		     union nfsd4_op_u *u)
+{
+	struct nfsd4_offload_status *os = &u->offload_status;
+	struct nfsd4_copy *copy;
+	struct nfs4_client *clp = cstate->clp;
+
+	copy = find_async_copy(clp, &os->stateid);
+	if (!copy) {
+		struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+
+		return manage_cpntf_state(nn, &os->stateid, clp, NULL);
+	} else
+		nfsd4_stop_copy(copy);
+
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_copy_notify(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+		  union nfsd4_op_u *u)
+{
+	struct nfsd4_copy_notify *cn = &u->copy_notify;
+	__be32 status;
+	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+	struct nfs4_stid *stid;
+	struct nfs4_cpntf_state *cps;
+	struct nfs4_client *clp = cstate->clp;
+
+	status = nfs4_preprocess_stateid_op(rqstp, cstate, &cstate->current_fh,
+					&cn->cpn_src_stateid, RD_STATE, NULL,
+					&stid);
+	if (status)
+		return status;
+
+	cn->cpn_sec = nn->nfsd4_lease;
+	cn->cpn_nsec = 0;
+
+	status = nfserrno(-ENOMEM);
+	cps = nfs4_alloc_init_cpntf_state(nn, stid);
+	if (!cps)
+		goto out;
+	memcpy(&cn->cpn_cnr_stateid, &cps->cp_stateid.stid, sizeof(stateid_t));
+	memcpy(&cps->cp_p_stateid, &stid->sc_stateid, sizeof(stateid_t));
+	memcpy(&cps->cp_p_clid, &clp->cl_clientid, sizeof(clientid_t));
+
+	/* For now, only return one server address in cpn_src, the
+	 * address used by the client to connect to this server.
+	 */
+	cn->cpn_src.nl4_type = NL4_NETADDR;
+	status = nfsd4_set_netaddr((struct sockaddr *)&rqstp->rq_daddr,
+				 &cn->cpn_src.u.nl4_addr);
+	WARN_ON_ONCE(status);
+	if (status) {
+		nfs4_put_cpntf_state(nn, cps);
+		goto out;
+	}
+out:
+	nfs4_put_stid(stid);
+	return status;
+}
+
+static __be32
+nfsd4_fallocate(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+		struct nfsd4_fallocate *fallocate, int flags)
+{
+	__be32 status;
+	struct nfsd_file *nf;
+
+	status = nfs4_preprocess_stateid_op(rqstp, cstate, &cstate->current_fh,
+					    &fallocate->falloc_stateid,
+					    WR_STATE, &nf, NULL);
+	if (status != nfs_ok) {
+		dprintk("NFSD: nfsd4_fallocate: couldn't process stateid!\n");
+		return status;
+	}
+
+	status = nfsd4_vfs_fallocate(rqstp, &cstate->current_fh, nf->nf_file,
+				     fallocate->falloc_offset,
+				     fallocate->falloc_length,
+				     flags);
+	nfsd_file_put(nf);
+	return status;
+}
+static __be32
+nfsd4_offload_status(struct svc_rqst *rqstp,
+		     struct nfsd4_compound_state *cstate,
+		     union nfsd4_op_u *u)
+{
+	struct nfsd4_offload_status *os = &u->offload_status;
+	__be32 status = 0;
+	struct nfsd4_copy *copy;
+	struct nfs4_client *clp = cstate->clp;
+
+	copy = find_async_copy(clp, &os->stateid);
+	if (copy) {
+		os->count = copy->cp_res.wr_bytes_written;
+		nfs4_put_copy(copy);
+	} else
+		status = nfserr_bad_stateid;
+
+	return status;
+}
+
+static __be32
+nfsd4_allocate(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+	       union nfsd4_op_u *u)
+{
+	return nfsd4_fallocate(rqstp, cstate, &u->allocate, 0);
+}
+
+static __be32
+nfsd4_deallocate(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+		 union nfsd4_op_u *u)
+{
+	return nfsd4_fallocate(rqstp, cstate, &u->deallocate,
+			       FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE);
+}
+
+static __be32
+nfsd4_seek(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+	   union nfsd4_op_u *u)
+{
+	struct nfsd4_seek *seek = &u->seek;
+	int whence;
+	__be32 status;
+	struct nfsd_file *nf;
+
+	status = nfs4_preprocess_stateid_op(rqstp, cstate, &cstate->current_fh,
+					    &seek->seek_stateid,
+					    RD_STATE, &nf, NULL);
+	if (status) {
+		dprintk("NFSD: nfsd4_seek: couldn't process stateid!\n");
+		return status;
+	}
+
+	switch (seek->seek_whence) {
+	case NFS4_CONTENT_DATA:
+		whence = SEEK_DATA;
+		break;
+	case NFS4_CONTENT_HOLE:
+		whence = SEEK_HOLE;
+		break;
+	default:
+		status = nfserr_union_notsupp;
+		goto out;
+	}
+
+	/*
+	 * Note:  This call does change file->f_pos, but nothing in NFSD
+	 *        should ever file->f_pos.
+	 */
+	seek->seek_pos = vfs_llseek(nf->nf_file, seek->seek_offset, whence);
+	if (seek->seek_pos < 0)
+		status = nfserrno(seek->seek_pos);
+	else if (seek->seek_pos >= i_size_read(file_inode(nf->nf_file)))
+		seek->seek_eof = true;
+
+out:
+	nfsd_file_put(nf);
+	return status;
+}
+
+/* This routine never returns NFS_OK!  If there are no other errors, it
+ * will return NFSERR_SAME or NFSERR_NOT_SAME depending on whether the
+ * attributes matched.  VERIFY is implemented by mapping NFSERR_SAME
+ * to NFS_OK after the call; NVERIFY by mapping NFSERR_NOT_SAME to NFS_OK.
+ */
+static __be32
+_nfsd4_verify(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+	     struct nfsd4_verify *verify)
+{
+	__be32 *buf, *p;
+	int count;
+	__be32 status;
+
+	status = fh_verify(rqstp, &cstate->current_fh, 0, NFSD_MAY_NOP);
+	if (status)
+		return status;
+
+	status = check_attr_support(rqstp, cstate, verify->ve_bmval, NULL);
+	if (status)
+		return status;
+
+	if ((verify->ve_bmval[0] & FATTR4_WORD0_RDATTR_ERROR)
+	    || (verify->ve_bmval[1] & NFSD_WRITEONLY_ATTRS_WORD1))
+		return nfserr_inval;
+	if (verify->ve_attrlen & 3)
+		return nfserr_inval;
+
+	/* count in words:
+	 *   bitmap_len(1) + bitmap(2) + attr_len(1) = 4
+	 */
+	count = 4 + (verify->ve_attrlen >> 2);
+	buf = kmalloc(count << 2, GFP_KERNEL);
+	if (!buf)
+		return nfserr_jukebox;
+
+	p = buf;
+	status = nfsd4_encode_fattr_to_buf(&p, count, &cstate->current_fh,
+				    cstate->current_fh.fh_export,
+				    cstate->current_fh.fh_dentry,
+				    verify->ve_bmval,
+				    rqstp, 0);
+	/*
+	 * If nfsd4_encode_fattr() ran out of space, assume that's because
+	 * the attributes are longer (hence different) than those given:
+	 */
+	if (status == nfserr_resource)
+		status = nfserr_not_same;
+	if (status)
+		goto out_kfree;
+
+	/* skip bitmap */
+	p = buf + 1 + ntohl(buf[0]);
+	status = nfserr_not_same;
+	if (ntohl(*p++) != verify->ve_attrlen)
+		goto out_kfree;
+	if (!memcmp(p, verify->ve_attrval, verify->ve_attrlen))
+		status = nfserr_same;
+
+out_kfree:
+	kfree(buf);
+	return status;
+}
+
+static __be32
+nfsd4_nverify(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+	      union nfsd4_op_u *u)
+{
+	__be32 status;
+
+	status = _nfsd4_verify(rqstp, cstate, &u->verify);
+	return status == nfserr_not_same ? nfs_ok : status;
+}
+
+static __be32
+nfsd4_verify(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+	     union nfsd4_op_u *u)
+{
+	__be32 status;
+
+	status = _nfsd4_verify(rqstp, cstate, &u->nverify);
+	return status == nfserr_same ? nfs_ok : status;
+}
+
+#ifdef CONFIG_NFSD_PNFS
+static const struct nfsd4_layout_ops *
+nfsd4_layout_verify(struct svc_export *exp, unsigned int layout_type)
+{
+	if (!exp->ex_layout_types) {
+		dprintk("%s: export does not support pNFS\n", __func__);
+		return NULL;
+	}
+
+	if (layout_type >= LAYOUT_TYPE_MAX ||
+	    !(exp->ex_layout_types & (1 << layout_type))) {
+		dprintk("%s: layout type %d not supported\n",
+			__func__, layout_type);
+		return NULL;
+	}
+
+	return nfsd4_layout_ops[layout_type];
+}
+
+static __be32
+nfsd4_getdeviceinfo(struct svc_rqst *rqstp,
+		struct nfsd4_compound_state *cstate, union nfsd4_op_u *u)
+{
+	struct nfsd4_getdeviceinfo *gdp = &u->getdeviceinfo;
+	const struct nfsd4_layout_ops *ops;
+	struct nfsd4_deviceid_map *map;
+	struct svc_export *exp;
+	__be32 nfserr;
+
+	dprintk("%s: layout_type %u dev_id [0x%llx:0x%x] maxcnt %u\n",
+	       __func__,
+	       gdp->gd_layout_type,
+	       gdp->gd_devid.fsid_idx, gdp->gd_devid.generation,
+	       gdp->gd_maxcount);
+
+	map = nfsd4_find_devid_map(gdp->gd_devid.fsid_idx);
+	if (!map) {
+		dprintk("%s: couldn't find device ID to export mapping!\n",
+			__func__);
+		return nfserr_noent;
+	}
+
+	exp = rqst_exp_find(rqstp, map->fsid_type, map->fsid);
+	if (IS_ERR(exp)) {
+		dprintk("%s: could not find device id\n", __func__);
+		return nfserr_noent;
+	}
+
+	nfserr = nfserr_layoutunavailable;
+	ops = nfsd4_layout_verify(exp, gdp->gd_layout_type);
+	if (!ops)
+		goto out;
+
+	nfserr = nfs_ok;
+	if (gdp->gd_maxcount != 0) {
+		nfserr = ops->proc_getdeviceinfo(exp->ex_path.mnt->mnt_sb,
+				rqstp, cstate->session->se_client, gdp);
+	}
+
+	gdp->gd_notify_types &= ops->notify_types;
+out:
+	exp_put(exp);
+	return nfserr;
+}
+
+static void
+nfsd4_getdeviceinfo_release(union nfsd4_op_u *u)
+{
+	kfree(u->getdeviceinfo.gd_device);
+}
+
+static __be32
+nfsd4_layoutget(struct svc_rqst *rqstp,
+		struct nfsd4_compound_state *cstate, union nfsd4_op_u *u)
+{
+	struct nfsd4_layoutget *lgp = &u->layoutget;
+	struct svc_fh *current_fh = &cstate->current_fh;
+	const struct nfsd4_layout_ops *ops;
+	struct nfs4_layout_stateid *ls;
+	__be32 nfserr;
+	int accmode = NFSD_MAY_READ_IF_EXEC;
+
+	switch (lgp->lg_seg.iomode) {
+	case IOMODE_READ:
+		accmode |= NFSD_MAY_READ;
+		break;
+	case IOMODE_RW:
+		accmode |= NFSD_MAY_READ | NFSD_MAY_WRITE;
+		break;
+	default:
+		dprintk("%s: invalid iomode %d\n",
+			__func__, lgp->lg_seg.iomode);
+		nfserr = nfserr_badiomode;
+		goto out;
+	}
+
+	nfserr = fh_verify(rqstp, current_fh, 0, accmode);
+	if (nfserr)
+		goto out;
+
+	nfserr = nfserr_layoutunavailable;
+	ops = nfsd4_layout_verify(current_fh->fh_export, lgp->lg_layout_type);
+	if (!ops)
+		goto out;
+
+	/*
+	 * Verify minlength and range as per RFC5661:
+	 *  o  If loga_length is less than loga_minlength,
+	 *     the metadata server MUST return NFS4ERR_INVAL.
+	 *  o  If the sum of loga_offset and loga_minlength exceeds
+	 *     NFS4_UINT64_MAX, and loga_minlength is not
+	 *     NFS4_UINT64_MAX, the error NFS4ERR_INVAL MUST result.
+	 *  o  If the sum of loga_offset and loga_length exceeds
+	 *     NFS4_UINT64_MAX, and loga_length is not NFS4_UINT64_MAX,
+	 *     the error NFS4ERR_INVAL MUST result.
+	 */
+	nfserr = nfserr_inval;
+	if (lgp->lg_seg.length < lgp->lg_minlength ||
+	    (lgp->lg_minlength != NFS4_MAX_UINT64 &&
+	     lgp->lg_minlength > NFS4_MAX_UINT64 - lgp->lg_seg.offset) ||
+	    (lgp->lg_seg.length != NFS4_MAX_UINT64 &&
+	     lgp->lg_seg.length > NFS4_MAX_UINT64 - lgp->lg_seg.offset))
+		goto out;
+	if (lgp->lg_seg.length == 0)
+		goto out;
+
+	nfserr = nfsd4_preprocess_layout_stateid(rqstp, cstate, &lgp->lg_sid,
+						true, lgp->lg_layout_type, &ls);
+	if (nfserr) {
+		trace_nfsd_layout_get_lookup_fail(&lgp->lg_sid);
+		goto out;
+	}
+
+	nfserr = nfserr_recallconflict;
+	if (atomic_read(&ls->ls_stid.sc_file->fi_lo_recalls))
+		goto out_put_stid;
+
+	nfserr = ops->proc_layoutget(d_inode(current_fh->fh_dentry),
+				     current_fh, lgp);
+	if (nfserr)
+		goto out_put_stid;
+
+	nfserr = nfsd4_insert_layout(lgp, ls);
+
+out_put_stid:
+	mutex_unlock(&ls->ls_mutex);
+	nfs4_put_stid(&ls->ls_stid);
+out:
+	return nfserr;
+}
+
+static void
+nfsd4_layoutget_release(union nfsd4_op_u *u)
+{
+	kfree(u->layoutget.lg_content);
+}
+
+static __be32
+nfsd4_layoutcommit(struct svc_rqst *rqstp,
+		struct nfsd4_compound_state *cstate, union nfsd4_op_u *u)
+{
+	struct nfsd4_layoutcommit *lcp = &u->layoutcommit;
+	const struct nfsd4_layout_seg *seg = &lcp->lc_seg;
+	struct svc_fh *current_fh = &cstate->current_fh;
+	const struct nfsd4_layout_ops *ops;
+	loff_t new_size = lcp->lc_last_wr + 1;
+	struct inode *inode;
+	struct nfs4_layout_stateid *ls;
+	__be32 nfserr;
+
+	nfserr = fh_verify(rqstp, current_fh, 0, NFSD_MAY_WRITE);
+	if (nfserr)
+		goto out;
+
+	nfserr = nfserr_layoutunavailable;
+	ops = nfsd4_layout_verify(current_fh->fh_export, lcp->lc_layout_type);
+	if (!ops)
+		goto out;
+	inode = d_inode(current_fh->fh_dentry);
+
+	nfserr = nfserr_inval;
+	if (new_size <= seg->offset) {
+		dprintk("pnfsd: last write before layout segment\n");
+		goto out;
+	}
+	if (new_size > seg->offset + seg->length) {
+		dprintk("pnfsd: last write beyond layout segment\n");
+		goto out;
+	}
+	if (!lcp->lc_newoffset && new_size > i_size_read(inode)) {
+		dprintk("pnfsd: layoutcommit beyond EOF\n");
+		goto out;
+	}
+
+	nfserr = nfsd4_preprocess_layout_stateid(rqstp, cstate, &lcp->lc_sid,
+						false, lcp->lc_layout_type,
+						&ls);
+	if (nfserr) {
+		trace_nfsd_layout_commit_lookup_fail(&lcp->lc_sid);
+		/* fixup error code as per RFC5661 */
+		if (nfserr == nfserr_bad_stateid)
+			nfserr = nfserr_badlayout;
+		goto out;
+	}
+
+	/* LAYOUTCOMMIT does not require any serialization */
+	mutex_unlock(&ls->ls_mutex);
+
+	if (new_size > i_size_read(inode)) {
+		lcp->lc_size_chg = 1;
+		lcp->lc_newsize = new_size;
+	} else {
+		lcp->lc_size_chg = 0;
+	}
+
+	nfserr = ops->proc_layoutcommit(inode, lcp);
+	nfs4_put_stid(&ls->ls_stid);
+out:
+	return nfserr;
+}
+
+static __be32
+nfsd4_layoutreturn(struct svc_rqst *rqstp,
+		struct nfsd4_compound_state *cstate, union nfsd4_op_u *u)
+{
+	struct nfsd4_layoutreturn *lrp = &u->layoutreturn;
+	struct svc_fh *current_fh = &cstate->current_fh;
+	__be32 nfserr;
+
+	nfserr = fh_verify(rqstp, current_fh, 0, NFSD_MAY_NOP);
+	if (nfserr)
+		goto out;
+
+	nfserr = nfserr_layoutunavailable;
+	if (!nfsd4_layout_verify(current_fh->fh_export, lrp->lr_layout_type))
+		goto out;
+
+	switch (lrp->lr_seg.iomode) {
+	case IOMODE_READ:
+	case IOMODE_RW:
+	case IOMODE_ANY:
+		break;
+	default:
+		dprintk("%s: invalid iomode %d\n", __func__,
+			lrp->lr_seg.iomode);
+		nfserr = nfserr_inval;
+		goto out;
+	}
+
+	switch (lrp->lr_return_type) {
+	case RETURN_FILE:
+		nfserr = nfsd4_return_file_layouts(rqstp, cstate, lrp);
+		break;
+	case RETURN_FSID:
+	case RETURN_ALL:
+		nfserr = nfsd4_return_client_layouts(rqstp, cstate, lrp);
+		break;
+	default:
+		dprintk("%s: invalid return_type %d\n", __func__,
+			lrp->lr_return_type);
+		nfserr = nfserr_inval;
+		break;
+	}
+out:
+	return nfserr;
+}
+#endif /* CONFIG_NFSD_PNFS */
+
+static __be32
+nfsd4_getxattr(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+	       union nfsd4_op_u *u)
+{
+	struct nfsd4_getxattr *getxattr = &u->getxattr;
+
+	return nfsd_getxattr(rqstp, &cstate->current_fh,
+			     getxattr->getxa_name, &getxattr->getxa_buf,
+			     &getxattr->getxa_len);
+}
+
+static __be32
+nfsd4_setxattr(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+	   union nfsd4_op_u *u)
+{
+	struct nfsd4_setxattr *setxattr = &u->setxattr;
+	__be32 ret;
+
+	if (opens_in_grace(SVC_NET(rqstp)))
+		return nfserr_grace;
+
+	ret = nfsd_setxattr(rqstp, &cstate->current_fh, setxattr->setxa_name,
+			    setxattr->setxa_buf, setxattr->setxa_len,
+			    setxattr->setxa_flags);
+
+	if (!ret)
+		set_change_info(&setxattr->setxa_cinfo, &cstate->current_fh);
+
+	return ret;
+}
+
+static __be32
+nfsd4_listxattrs(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+	   union nfsd4_op_u *u)
+{
+	/*
+	 * Get the entire list, then copy out only the user attributes
+	 * in the encode function.
+	 */
+	return nfsd_listxattr(rqstp, &cstate->current_fh,
+			     &u->listxattrs.lsxa_buf, &u->listxattrs.lsxa_len);
+}
+
+static __be32
+nfsd4_removexattr(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+	   union nfsd4_op_u *u)
+{
+	struct nfsd4_removexattr *removexattr = &u->removexattr;
+	__be32 ret;
+
+	if (opens_in_grace(SVC_NET(rqstp)))
+		return nfserr_grace;
+
+	ret = nfsd_removexattr(rqstp, &cstate->current_fh,
+	    removexattr->rmxa_name);
+
+	if (!ret)
+		set_change_info(&removexattr->rmxa_cinfo, &cstate->current_fh);
+
+	return ret;
+}
+
+/*
+ * NULL call.
+ */
+static __be32
+nfsd4_proc_null(struct svc_rqst *rqstp)
+{
+	return rpc_success;
+}
+
+static inline void nfsd4_increment_op_stats(u32 opnum)
+{
+	if (opnum >= FIRST_NFS4_OP && opnum <= LAST_NFS4_OP)
+		nfsdstats.nfs4_opcount[opnum]++;
+}
+
+static const struct nfsd4_operation nfsd4_ops[];
+
+static const char *nfsd4_op_name(unsigned opnum);
+
+/*
+ * Enforce NFSv4.1 COMPOUND ordering rules:
+ *
+ * Also note, enforced elsewhere:
+ *	- SEQUENCE other than as first op results in
+ *	  NFS4ERR_SEQUENCE_POS. (Enforced in nfsd4_sequence().)
+ *	- BIND_CONN_TO_SESSION must be the only op in its compound.
+ *	  (Enforced in nfsd4_bind_conn_to_session().)
+ *	- DESTROY_SESSION must be the final operation in a compound, if
+ *	  sessionid's in SEQUENCE and DESTROY_SESSION are the same.
+ *	  (Enforced in nfsd4_destroy_session().)
+ */
+static __be32 nfs41_check_op_ordering(struct nfsd4_compoundargs *args)
+{
+	struct nfsd4_op *first_op = &args->ops[0];
+
+	/* These ordering requirements don't apply to NFSv4.0: */
+	if (args->minorversion == 0)
+		return nfs_ok;
+	/* This is weird, but OK, not our problem: */
+	if (args->opcnt == 0)
+		return nfs_ok;
+	if (first_op->status == nfserr_op_illegal)
+		return nfs_ok;
+	if (!(nfsd4_ops[first_op->opnum].op_flags & ALLOWED_AS_FIRST_OP))
+		return nfserr_op_not_in_session;
+	if (first_op->opnum == OP_SEQUENCE)
+		return nfs_ok;
+	/*
+	 * So first_op is something allowed outside a session, like
+	 * EXCHANGE_ID; but then it has to be the only op in the
+	 * compound:
+	 */
+	if (args->opcnt != 1)
+		return nfserr_not_only_op;
+	return nfs_ok;
+}
+
+const struct nfsd4_operation *OPDESC(struct nfsd4_op *op)
+{
+	return &nfsd4_ops[op->opnum];
+}
+
+bool nfsd4_cache_this_op(struct nfsd4_op *op)
+{
+	if (op->opnum == OP_ILLEGAL)
+		return false;
+	return OPDESC(op)->op_flags & OP_CACHEME;
+}
+
+static bool need_wrongsec_check(struct svc_rqst *rqstp)
+{
+	struct nfsd4_compoundres *resp = rqstp->rq_resp;
+	struct nfsd4_compoundargs *argp = rqstp->rq_argp;
+	struct nfsd4_op *this = &argp->ops[resp->opcnt - 1];
+	struct nfsd4_op *next = &argp->ops[resp->opcnt];
+	const struct nfsd4_operation *thisd = OPDESC(this);
+	const struct nfsd4_operation *nextd;
+
+	/*
+	 * Most ops check wronsec on our own; only the putfh-like ops
+	 * have special rules.
+	 */
+	if (!(thisd->op_flags & OP_IS_PUTFH_LIKE))
+		return false;
+	/*
+	 * rfc 5661 2.6.3.1.1.6: don't bother erroring out a
+	 * put-filehandle operation if we're not going to use the
+	 * result:
+	 */
+	if (argp->opcnt == resp->opcnt)
+		return false;
+	if (next->opnum == OP_ILLEGAL)
+		return false;
+	nextd = OPDESC(next);
+	/*
+	 * Rest of 2.6.3.1.1: certain operations will return WRONGSEC
+	 * errors themselves as necessary; others should check for them
+	 * now:
+	 */
+	return !(nextd->op_flags & OP_HANDLES_WRONGSEC);
+}
+
+static void svcxdr_init_encode(struct svc_rqst *rqstp,
+			       struct nfsd4_compoundres *resp)
+{
+	struct xdr_stream *xdr = &resp->xdr;
+	struct xdr_buf *buf = &rqstp->rq_res;
+	struct kvec *head = buf->head;
+
+	xdr->buf = buf;
+	xdr->iov = head;
+	xdr->p   = head->iov_base + head->iov_len;
+	xdr->end = head->iov_base + PAGE_SIZE - rqstp->rq_auth_slack;
+	/* Tail and page_len should be zero at this point: */
+	buf->len = buf->head[0].iov_len;
+	xdr->scratch.iov_len = 0;
+	xdr->page_ptr = buf->pages - 1;
+	buf->buflen = PAGE_SIZE * (1 + rqstp->rq_page_end - buf->pages)
+		- rqstp->rq_auth_slack;
+}
+
+#ifdef CONFIG_NFSD_V4_2_INTER_SSC
+static void
+check_if_stalefh_allowed(struct nfsd4_compoundargs *args)
+{
+	struct nfsd4_op	*op, *current_op = NULL, *saved_op = NULL;
+	struct nfsd4_copy *copy;
+	struct nfsd4_putfh *putfh;
+	int i;
+
+	/* traverse all operation and if it's a COPY compound, mark the
+	 * source filehandle to skip verification
+	 */
+	for (i = 0; i < args->opcnt; i++) {
+		op = &args->ops[i];
+		if (op->opnum == OP_PUTFH)
+			current_op = op;
+		else if (op->opnum == OP_SAVEFH)
+			saved_op = current_op;
+		else if (op->opnum == OP_RESTOREFH)
+			current_op = saved_op;
+		else if (op->opnum == OP_COPY) {
+			copy = (struct nfsd4_copy *)&op->u;
+			if (!saved_op) {
+				op->status = nfserr_nofilehandle;
+				return;
+			}
+			putfh = (struct nfsd4_putfh *)&saved_op->u;
+			if (!copy->cp_intra)
+				putfh->no_verify = true;
+		}
+	}
+}
+#else
+static void
+check_if_stalefh_allowed(struct nfsd4_compoundargs *args)
+{
+}
+#endif
+
+/*
+ * COMPOUND call.
+ */
+static __be32
+nfsd4_proc_compound(struct svc_rqst *rqstp)
+{
+	struct nfsd4_compoundargs *args = rqstp->rq_argp;
+	struct nfsd4_compoundres *resp = rqstp->rq_resp;
+	struct nfsd4_op	*op;
+	struct nfsd4_compound_state *cstate = &resp->cstate;
+	struct svc_fh *current_fh = &cstate->current_fh;
+	struct svc_fh *save_fh = &cstate->save_fh;
+	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+	__be32		status;
+
+	svcxdr_init_encode(rqstp, resp);
+	resp->tagp = resp->xdr.p;
+	/* reserve space for: taglen, tag, and opcnt */
+	xdr_reserve_space(&resp->xdr, 8 + args->taglen);
+	resp->taglen = args->taglen;
+	resp->tag = args->tag;
+	resp->rqstp = rqstp;
+	cstate->minorversion = args->minorversion;
+	fh_init(current_fh, NFS4_FHSIZE);
+	fh_init(save_fh, NFS4_FHSIZE);
+	/*
+	 * Don't use the deferral mechanism for NFSv4; compounds make it
+	 * too hard to avoid non-idempotency problems.
+	 */
+	clear_bit(RQ_USEDEFERRAL, &rqstp->rq_flags);
+
+	/*
+	 * According to RFC3010, this takes precedence over all other errors.
+	 */
+	status = nfserr_minor_vers_mismatch;
+	if (nfsd_minorversion(nn, args->minorversion, NFSD_TEST) <= 0)
+		goto out;
+	status = nfserr_resource;
+	if (args->opcnt > NFSD_MAX_OPS_PER_COMPOUND)
+		goto out;
+
+	status = nfs41_check_op_ordering(args);
+	if (status) {
+		op = &args->ops[0];
+		op->status = status;
+		resp->opcnt = 1;
+		goto encode_op;
+	}
+	check_if_stalefh_allowed(args);
+
+	rqstp->rq_lease_breaker = (void **)&cstate->clp;
+
+	trace_nfsd_compound(rqstp, args->opcnt);
+	while (!status && resp->opcnt < args->opcnt) {
+		op = &args->ops[resp->opcnt++];
+
+		/*
+		 * The XDR decode routines may have pre-set op->status;
+		 * for example, if there is a miscellaneous XDR error
+		 * it will be set to nfserr_bad_xdr.
+		 */
+		if (op->status) {
+			if (op->opnum == OP_OPEN)
+				op->status = nfsd4_open_omfg(rqstp, cstate, op);
+			goto encode_op;
+		}
+		if (!current_fh->fh_dentry &&
+				!HAS_FH_FLAG(current_fh, NFSD4_FH_FOREIGN)) {
+			if (!(op->opdesc->op_flags & ALLOWED_WITHOUT_FH)) {
+				op->status = nfserr_nofilehandle;
+				goto encode_op;
+			}
+		} else if (current_fh->fh_export &&
+			   current_fh->fh_export->ex_fslocs.migrated &&
+			  !(op->opdesc->op_flags & ALLOWED_ON_ABSENT_FS)) {
+			op->status = nfserr_moved;
+			goto encode_op;
+		}
+
+		fh_clear_wcc(current_fh);
+
+		/* If op is non-idempotent */
+		if (op->opdesc->op_flags & OP_MODIFIES_SOMETHING) {
+			/*
+			 * Don't execute this op if we couldn't encode a
+			 * succesful reply:
+			 */
+			u32 plen = op->opdesc->op_rsize_bop(rqstp, op);
+			/*
+			 * Plus if there's another operation, make sure
+			 * we'll have space to at least encode an error:
+			 */
+			if (resp->opcnt < args->opcnt)
+				plen += COMPOUND_ERR_SLACK_SPACE;
+			op->status = nfsd4_check_resp_size(resp, plen);
+		}
+
+		if (op->status)
+			goto encode_op;
+
+		if (op->opdesc->op_get_currentstateid)
+			op->opdesc->op_get_currentstateid(cstate, &op->u);
+		op->status = op->opdesc->op_func(rqstp, cstate, &op->u);
+
+		/* Only from SEQUENCE */
+		if (cstate->status == nfserr_replay_cache) {
+			dprintk("%s NFS4.1 replay from cache\n", __func__);
+			status = op->status;
+			goto out;
+		}
+		if (!op->status) {
+			if (op->opdesc->op_set_currentstateid)
+				op->opdesc->op_set_currentstateid(cstate, &op->u);
+
+			if (op->opdesc->op_flags & OP_CLEAR_STATEID)
+				clear_current_stateid(cstate);
+
+			if (current_fh->fh_export &&
+					need_wrongsec_check(rqstp))
+				op->status = check_nfsd_access(current_fh->fh_export, rqstp);
+		}
+encode_op:
+		if (op->status == nfserr_replay_me) {
+			op->replay = &cstate->replay_owner->so_replay;
+			nfsd4_encode_replay(&resp->xdr, op);
+			status = op->status = op->replay->rp_status;
+		} else {
+			nfsd4_encode_operation(resp, op);
+			status = op->status;
+		}
+
+		trace_nfsd_compound_status(args->opcnt, resp->opcnt, status,
+					   nfsd4_op_name(op->opnum));
+
+		nfsd4_cstate_clear_replay(cstate);
+		nfsd4_increment_op_stats(op->opnum);
+	}
+
+	fh_put(current_fh);
+	fh_put(save_fh);
+	BUG_ON(cstate->replay_owner);
+out:
+	cstate->status = status;
+	/* Reset deferral mechanism for RPC deferrals */
+	set_bit(RQ_USEDEFERRAL, &rqstp->rq_flags);
+	return rpc_success;
+}
+
+#define op_encode_hdr_size		(2)
+#define op_encode_stateid_maxsz		(XDR_QUADLEN(NFS4_STATEID_SIZE))
+#define op_encode_verifier_maxsz	(XDR_QUADLEN(NFS4_VERIFIER_SIZE))
+#define op_encode_change_info_maxsz	(5)
+#define nfs4_fattr_bitmap_maxsz		(4)
+
+/* We'll fall back on returning no lockowner if run out of space: */
+#define op_encode_lockowner_maxsz	(0)
+#define op_encode_lock_denied_maxsz	(8 + op_encode_lockowner_maxsz)
+
+#define nfs4_owner_maxsz		(1 + XDR_QUADLEN(IDMAP_NAMESZ))
+
+#define op_encode_ace_maxsz		(3 + nfs4_owner_maxsz)
+#define op_encode_delegation_maxsz	(1 + op_encode_stateid_maxsz + 1 + \
+					 op_encode_ace_maxsz)
+
+#define op_encode_channel_attrs_maxsz	(6 + 1 + 1)
+
+static inline u32 nfsd4_only_status_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
+{
+	return (op_encode_hdr_size) * sizeof(__be32);
+}
+
+static inline u32 nfsd4_status_stateid_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
+{
+	return (op_encode_hdr_size + op_encode_stateid_maxsz)* sizeof(__be32);
+}
+
+static inline u32 nfsd4_access_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
+{
+	/* ac_supported, ac_resp_access */
+	return (op_encode_hdr_size + 2)* sizeof(__be32);
+}
+
+static inline u32 nfsd4_commit_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
+{
+	return (op_encode_hdr_size + op_encode_verifier_maxsz) * sizeof(__be32);
+}
+
+static inline u32 nfsd4_create_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
+{
+	return (op_encode_hdr_size + op_encode_change_info_maxsz
+		+ nfs4_fattr_bitmap_maxsz) * sizeof(__be32);
+}
+
+/*
+ * Note since this is an idempotent operation we won't insist on failing
+ * the op prematurely if the estimate is too large.  We may turn off splice
+ * reads unnecessarily.
+ */
+static inline u32 nfsd4_getattr_rsize(struct svc_rqst *rqstp,
+				      struct nfsd4_op *op)
+{
+	u32 *bmap = op->u.getattr.ga_bmval;
+	u32 bmap0 = bmap[0], bmap1 = bmap[1], bmap2 = bmap[2];
+	u32 ret = 0;
+
+	if (bmap0 & FATTR4_WORD0_ACL)
+		return svc_max_payload(rqstp);
+	if (bmap0 & FATTR4_WORD0_FS_LOCATIONS)
+		return svc_max_payload(rqstp);
+
+	if (bmap1 & FATTR4_WORD1_OWNER) {
+		ret += IDMAP_NAMESZ + 4;
+		bmap1 &= ~FATTR4_WORD1_OWNER;
+	}
+	if (bmap1 & FATTR4_WORD1_OWNER_GROUP) {
+		ret += IDMAP_NAMESZ + 4;
+		bmap1 &= ~FATTR4_WORD1_OWNER_GROUP;
+	}
+	if (bmap0 & FATTR4_WORD0_FILEHANDLE) {
+		ret += NFS4_FHSIZE + 4;
+		bmap0 &= ~FATTR4_WORD0_FILEHANDLE;
+	}
+	if (bmap2 & FATTR4_WORD2_SECURITY_LABEL) {
+		ret += NFS4_MAXLABELLEN + 12;
+		bmap2 &= ~FATTR4_WORD2_SECURITY_LABEL;
+	}
+	/*
+	 * Largest of remaining attributes are 16 bytes (e.g.,
+	 * supported_attributes)
+	 */
+	ret += 16 * (hweight32(bmap0) + hweight32(bmap1) + hweight32(bmap2));
+	/* bitmask, length */
+	ret += 20;
+	return ret;
+}
+
+static inline u32 nfsd4_getfh_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
+{
+	return (op_encode_hdr_size + 1) * sizeof(__be32) + NFS4_FHSIZE;
+}
+
+static inline u32 nfsd4_link_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
+{
+	return (op_encode_hdr_size + op_encode_change_info_maxsz)
+		* sizeof(__be32);
+}
+
+static inline u32 nfsd4_lock_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
+{
+	return (op_encode_hdr_size + op_encode_lock_denied_maxsz)
+		* sizeof(__be32);
+}
+
+static inline u32 nfsd4_open_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
+{
+	return (op_encode_hdr_size + op_encode_stateid_maxsz
+		+ op_encode_change_info_maxsz + 1
+		+ nfs4_fattr_bitmap_maxsz
+		+ op_encode_delegation_maxsz) * sizeof(__be32);
+}
+
+static inline u32 nfsd4_read_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
+{
+	u32 maxcount = 0, rlen = 0;
+
+	maxcount = svc_max_payload(rqstp);
+	rlen = min(op->u.read.rd_length, maxcount);
+
+	return (op_encode_hdr_size + 2 + XDR_QUADLEN(rlen)) * sizeof(__be32);
+}
+
+static inline u32 nfsd4_read_plus_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
+{
+	u32 maxcount = svc_max_payload(rqstp);
+	u32 rlen = min(op->u.read.rd_length, maxcount);
+	/*
+	 * If we detect that the file changed during hole encoding, then we
+	 * recover by encoding the remaining reply as data. This means we need
+	 * to set aside enough room to encode two data segments.
+	 */
+	u32 seg_len = 2 * (1 + 2 + 1);
+
+	return (op_encode_hdr_size + 2 + seg_len + XDR_QUADLEN(rlen)) * sizeof(__be32);
+}
+
+static inline u32 nfsd4_readdir_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
+{
+	u32 maxcount = 0, rlen = 0;
+
+	maxcount = svc_max_payload(rqstp);
+	rlen = min(op->u.readdir.rd_maxcount, maxcount);
+
+	return (op_encode_hdr_size + op_encode_verifier_maxsz +
+		XDR_QUADLEN(rlen)) * sizeof(__be32);
+}
+
+static inline u32 nfsd4_readlink_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
+{
+	return (op_encode_hdr_size + 1) * sizeof(__be32) + PAGE_SIZE;
+}
+
+static inline u32 nfsd4_remove_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
+{
+	return (op_encode_hdr_size + op_encode_change_info_maxsz)
+		* sizeof(__be32);
+}
+
+static inline u32 nfsd4_rename_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
+{
+	return (op_encode_hdr_size + op_encode_change_info_maxsz
+		+ op_encode_change_info_maxsz) * sizeof(__be32);
+}
+
+static inline u32 nfsd4_sequence_rsize(struct svc_rqst *rqstp,
+				       struct nfsd4_op *op)
+{
+	return (op_encode_hdr_size
+		+ XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN) + 5) * sizeof(__be32);
+}
+
+static inline u32 nfsd4_test_stateid_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
+{
+	return (op_encode_hdr_size + 1 + op->u.test_stateid.ts_num_ids)
+		* sizeof(__be32);
+}
+
+static inline u32 nfsd4_setattr_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
+{
+	return (op_encode_hdr_size + nfs4_fattr_bitmap_maxsz) * sizeof(__be32);
+}
+
+static inline u32 nfsd4_secinfo_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
+{
+	return (op_encode_hdr_size + RPC_AUTH_MAXFLAVOR *
+		(4 + XDR_QUADLEN(GSS_OID_MAX_LEN))) * sizeof(__be32);
+}
+
+static inline u32 nfsd4_setclientid_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
+{
+	return (op_encode_hdr_size + 2 + XDR_QUADLEN(NFS4_VERIFIER_SIZE)) *
+								sizeof(__be32);
+}
+
+static inline u32 nfsd4_write_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
+{
+	return (op_encode_hdr_size + 2 + op_encode_verifier_maxsz) * sizeof(__be32);
+}
+
+static inline u32 nfsd4_exchange_id_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
+{
+	return (op_encode_hdr_size + 2 + 1 + /* eir_clientid, eir_sequenceid */\
+		1 + 1 + /* eir_flags, spr_how */\
+		4 + /* spo_must_enforce & _allow with bitmap */\
+		2 + /*eir_server_owner.so_minor_id */\
+		/* eir_server_owner.so_major_id<> */\
+		XDR_QUADLEN(NFS4_OPAQUE_LIMIT) + 1 +\
+		/* eir_server_scope<> */\
+		XDR_QUADLEN(NFS4_OPAQUE_LIMIT) + 1 +\
+		1 + /* eir_server_impl_id array length */\
+		0 /* ignored eir_server_impl_id contents */) * sizeof(__be32);
+}
+
+static inline u32 nfsd4_bind_conn_to_session_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
+{
+	return (op_encode_hdr_size + \
+		XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN) + /* bctsr_sessid */\
+		2 /* bctsr_dir, use_conn_in_rdma_mode */) * sizeof(__be32);
+}
+
+static inline u32 nfsd4_create_session_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
+{
+	return (op_encode_hdr_size + \
+		XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN) + /* sessionid */\
+		2 + /* csr_sequence, csr_flags */\
+		op_encode_channel_attrs_maxsz + \
+		op_encode_channel_attrs_maxsz) * sizeof(__be32);
+}
+
+static inline u32 nfsd4_copy_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
+{
+	return (op_encode_hdr_size +
+		1 /* wr_callback */ +
+		op_encode_stateid_maxsz /* wr_callback */ +
+		2 /* wr_count */ +
+		1 /* wr_committed */ +
+		op_encode_verifier_maxsz +
+		1 /* cr_consecutive */ +
+		1 /* cr_synchronous */) * sizeof(__be32);
+}
+
+static inline u32 nfsd4_offload_status_rsize(struct svc_rqst *rqstp,
+					     struct nfsd4_op *op)
+{
+	return (op_encode_hdr_size +
+		2 /* osr_count */ +
+		1 /* osr_complete<1> optional 0 for now */) * sizeof(__be32);
+}
+
+static inline u32 nfsd4_copy_notify_rsize(struct svc_rqst *rqstp,
+					struct nfsd4_op *op)
+{
+	return (op_encode_hdr_size +
+		3 /* cnr_lease_time */ +
+		1 /* We support one cnr_source_server */ +
+		1 /* cnr_stateid seq */ +
+		op_encode_stateid_maxsz /* cnr_stateid */ +
+		1 /* num cnr_source_server*/ +
+		1 /* nl4_type */ +
+		1 /* nl4 size */ +
+		XDR_QUADLEN(NFS4_OPAQUE_LIMIT) /*nl4_loc + nl4_loc_sz */)
+		* sizeof(__be32);
+}
+
+#ifdef CONFIG_NFSD_PNFS
+static inline u32 nfsd4_getdeviceinfo_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
+{
+	u32 maxcount = 0, rlen = 0;
+
+	maxcount = svc_max_payload(rqstp);
+	rlen = min(op->u.getdeviceinfo.gd_maxcount, maxcount);
+
+	return (op_encode_hdr_size +
+		1 /* gd_layout_type*/ +
+		XDR_QUADLEN(rlen) +
+		2 /* gd_notify_types */) * sizeof(__be32);
+}
+
+/*
+ * At this stage we don't really know what layout driver will handle the request,
+ * so we need to define an arbitrary upper bound here.
+ */
+#define MAX_LAYOUT_SIZE		128
+static inline u32 nfsd4_layoutget_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
+{
+	return (op_encode_hdr_size +
+		1 /* logr_return_on_close */ +
+		op_encode_stateid_maxsz +
+		1 /* nr of layouts */ +
+		MAX_LAYOUT_SIZE) * sizeof(__be32);
+}
+
+static inline u32 nfsd4_layoutcommit_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
+{
+	return (op_encode_hdr_size +
+		1 /* locr_newsize */ +
+		2 /* ns_size */) * sizeof(__be32);
+}
+
+static inline u32 nfsd4_layoutreturn_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
+{
+	return (op_encode_hdr_size +
+		1 /* lrs_stateid */ +
+		op_encode_stateid_maxsz) * sizeof(__be32);
+}
+#endif /* CONFIG_NFSD_PNFS */
+
+
+static inline u32 nfsd4_seek_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
+{
+	return (op_encode_hdr_size + 3) * sizeof(__be32);
+}
+
+static inline u32 nfsd4_getxattr_rsize(struct svc_rqst *rqstp,
+				       struct nfsd4_op *op)
+{
+	u32 maxcount, rlen;
+
+	maxcount = svc_max_payload(rqstp);
+	rlen = min_t(u32, XATTR_SIZE_MAX, maxcount);
+
+	return (op_encode_hdr_size + 1 + XDR_QUADLEN(rlen)) * sizeof(__be32);
+}
+
+static inline u32 nfsd4_setxattr_rsize(struct svc_rqst *rqstp,
+				       struct nfsd4_op *op)
+{
+	return (op_encode_hdr_size + op_encode_change_info_maxsz)
+		* sizeof(__be32);
+}
+static inline u32 nfsd4_listxattrs_rsize(struct svc_rqst *rqstp,
+					 struct nfsd4_op *op)
+{
+	u32 maxcount, rlen;
+
+	maxcount = svc_max_payload(rqstp);
+	rlen = min(op->u.listxattrs.lsxa_maxcount, maxcount);
+
+	return (op_encode_hdr_size + 4 + XDR_QUADLEN(rlen)) * sizeof(__be32);
+}
+
+static inline u32 nfsd4_removexattr_rsize(struct svc_rqst *rqstp,
+					  struct nfsd4_op *op)
+{
+	return (op_encode_hdr_size + op_encode_change_info_maxsz)
+		* sizeof(__be32);
+}
+
+
+static const struct nfsd4_operation nfsd4_ops[] = {
+	[OP_ACCESS] = {
+		.op_func = nfsd4_access,
+		.op_name = "OP_ACCESS",
+		.op_rsize_bop = nfsd4_access_rsize,
+	},
+	[OP_CLOSE] = {
+		.op_func = nfsd4_close,
+		.op_flags = OP_MODIFIES_SOMETHING,
+		.op_name = "OP_CLOSE",
+		.op_rsize_bop = nfsd4_status_stateid_rsize,
+		.op_get_currentstateid = nfsd4_get_closestateid,
+		.op_set_currentstateid = nfsd4_set_closestateid,
+	},
+	[OP_COMMIT] = {
+		.op_func = nfsd4_commit,
+		.op_flags = OP_MODIFIES_SOMETHING,
+		.op_name = "OP_COMMIT",
+		.op_rsize_bop = nfsd4_commit_rsize,
+	},
+	[OP_CREATE] = {
+		.op_func = nfsd4_create,
+		.op_flags = OP_MODIFIES_SOMETHING | OP_CACHEME | OP_CLEAR_STATEID,
+		.op_name = "OP_CREATE",
+		.op_rsize_bop = nfsd4_create_rsize,
+	},
+	[OP_DELEGRETURN] = {
+		.op_func = nfsd4_delegreturn,
+		.op_flags = OP_MODIFIES_SOMETHING,
+		.op_name = "OP_DELEGRETURN",
+		.op_rsize_bop = nfsd4_only_status_rsize,
+		.op_get_currentstateid = nfsd4_get_delegreturnstateid,
+	},
+	[OP_GETATTR] = {
+		.op_func = nfsd4_getattr,
+		.op_flags = ALLOWED_ON_ABSENT_FS,
+		.op_rsize_bop = nfsd4_getattr_rsize,
+		.op_name = "OP_GETATTR",
+	},
+	[OP_GETFH] = {
+		.op_func = nfsd4_getfh,
+		.op_name = "OP_GETFH",
+		.op_rsize_bop = nfsd4_getfh_rsize,
+	},
+	[OP_LINK] = {
+		.op_func = nfsd4_link,
+		.op_flags = ALLOWED_ON_ABSENT_FS | OP_MODIFIES_SOMETHING
+				| OP_CACHEME,
+		.op_name = "OP_LINK",
+		.op_rsize_bop = nfsd4_link_rsize,
+	},
+	[OP_LOCK] = {
+		.op_func = nfsd4_lock,
+		.op_flags = OP_MODIFIES_SOMETHING |
+				OP_NONTRIVIAL_ERROR_ENCODE,
+		.op_name = "OP_LOCK",
+		.op_rsize_bop = nfsd4_lock_rsize,
+		.op_set_currentstateid = nfsd4_set_lockstateid,
+	},
+	[OP_LOCKT] = {
+		.op_func = nfsd4_lockt,
+		.op_flags = OP_NONTRIVIAL_ERROR_ENCODE,
+		.op_name = "OP_LOCKT",
+		.op_rsize_bop = nfsd4_lock_rsize,
+	},
+	[OP_LOCKU] = {
+		.op_func = nfsd4_locku,
+		.op_flags = OP_MODIFIES_SOMETHING,
+		.op_name = "OP_LOCKU",
+		.op_rsize_bop = nfsd4_status_stateid_rsize,
+		.op_get_currentstateid = nfsd4_get_lockustateid,
+	},
+	[OP_LOOKUP] = {
+		.op_func = nfsd4_lookup,
+		.op_flags = OP_HANDLES_WRONGSEC | OP_CLEAR_STATEID,
+		.op_name = "OP_LOOKUP",
+		.op_rsize_bop = nfsd4_only_status_rsize,
+	},
+	[OP_LOOKUPP] = {
+		.op_func = nfsd4_lookupp,
+		.op_flags = OP_HANDLES_WRONGSEC | OP_CLEAR_STATEID,
+		.op_name = "OP_LOOKUPP",
+		.op_rsize_bop = nfsd4_only_status_rsize,
+	},
+	[OP_NVERIFY] = {
+		.op_func = nfsd4_nverify,
+		.op_name = "OP_NVERIFY",
+		.op_rsize_bop = nfsd4_only_status_rsize,
+	},
+	[OP_OPEN] = {
+		.op_func = nfsd4_open,
+		.op_flags = OP_HANDLES_WRONGSEC | OP_MODIFIES_SOMETHING,
+		.op_name = "OP_OPEN",
+		.op_rsize_bop = nfsd4_open_rsize,
+		.op_set_currentstateid = nfsd4_set_openstateid,
+	},
+	[OP_OPEN_CONFIRM] = {
+		.op_func = nfsd4_open_confirm,
+		.op_flags = OP_MODIFIES_SOMETHING,
+		.op_name = "OP_OPEN_CONFIRM",
+		.op_rsize_bop = nfsd4_status_stateid_rsize,
+	},
+	[OP_OPEN_DOWNGRADE] = {
+		.op_func = nfsd4_open_downgrade,
+		.op_flags = OP_MODIFIES_SOMETHING,
+		.op_name = "OP_OPEN_DOWNGRADE",
+		.op_rsize_bop = nfsd4_status_stateid_rsize,
+		.op_get_currentstateid = nfsd4_get_opendowngradestateid,
+		.op_set_currentstateid = nfsd4_set_opendowngradestateid,
+	},
+	[OP_PUTFH] = {
+		.op_func = nfsd4_putfh,
+		.op_flags = ALLOWED_WITHOUT_FH | ALLOWED_ON_ABSENT_FS
+				| OP_IS_PUTFH_LIKE | OP_CLEAR_STATEID,
+		.op_name = "OP_PUTFH",
+		.op_rsize_bop = nfsd4_only_status_rsize,
+	},
+	[OP_PUTPUBFH] = {
+		.op_func = nfsd4_putrootfh,
+		.op_flags = ALLOWED_WITHOUT_FH | ALLOWED_ON_ABSENT_FS
+				| OP_IS_PUTFH_LIKE | OP_CLEAR_STATEID,
+		.op_name = "OP_PUTPUBFH",
+		.op_rsize_bop = nfsd4_only_status_rsize,
+	},
+	[OP_PUTROOTFH] = {
+		.op_func = nfsd4_putrootfh,
+		.op_flags = ALLOWED_WITHOUT_FH | ALLOWED_ON_ABSENT_FS
+				| OP_IS_PUTFH_LIKE | OP_CLEAR_STATEID,
+		.op_name = "OP_PUTROOTFH",
+		.op_rsize_bop = nfsd4_only_status_rsize,
+	},
+	[OP_READ] = {
+		.op_func = nfsd4_read,
+		.op_release = nfsd4_read_release,
+		.op_name = "OP_READ",
+		.op_rsize_bop = nfsd4_read_rsize,
+		.op_get_currentstateid = nfsd4_get_readstateid,
+	},
+	[OP_READDIR] = {
+		.op_func = nfsd4_readdir,
+		.op_name = "OP_READDIR",
+		.op_rsize_bop = nfsd4_readdir_rsize,
+	},
+	[OP_READLINK] = {
+		.op_func = nfsd4_readlink,
+		.op_name = "OP_READLINK",
+		.op_rsize_bop = nfsd4_readlink_rsize,
+	},
+	[OP_REMOVE] = {
+		.op_func = nfsd4_remove,
+		.op_flags = OP_MODIFIES_SOMETHING | OP_CACHEME,
+		.op_name = "OP_REMOVE",
+		.op_rsize_bop = nfsd4_remove_rsize,
+	},
+	[OP_RENAME] = {
+		.op_func = nfsd4_rename,
+		.op_flags = OP_MODIFIES_SOMETHING | OP_CACHEME,
+		.op_name = "OP_RENAME",
+		.op_rsize_bop = nfsd4_rename_rsize,
+	},
+	[OP_RENEW] = {
+		.op_func = nfsd4_renew,
+		.op_flags = ALLOWED_WITHOUT_FH | ALLOWED_ON_ABSENT_FS
+				| OP_MODIFIES_SOMETHING,
+		.op_name = "OP_RENEW",
+		.op_rsize_bop = nfsd4_only_status_rsize,
+
+	},
+	[OP_RESTOREFH] = {
+		.op_func = nfsd4_restorefh,
+		.op_flags = ALLOWED_WITHOUT_FH | ALLOWED_ON_ABSENT_FS
+				| OP_IS_PUTFH_LIKE | OP_MODIFIES_SOMETHING,
+		.op_name = "OP_RESTOREFH",
+		.op_rsize_bop = nfsd4_only_status_rsize,
+	},
+	[OP_SAVEFH] = {
+		.op_func = nfsd4_savefh,
+		.op_flags = OP_HANDLES_WRONGSEC | OP_MODIFIES_SOMETHING,
+		.op_name = "OP_SAVEFH",
+		.op_rsize_bop = nfsd4_only_status_rsize,
+	},
+	[OP_SECINFO] = {
+		.op_func = nfsd4_secinfo,
+		.op_release = nfsd4_secinfo_release,
+		.op_flags = OP_HANDLES_WRONGSEC,
+		.op_name = "OP_SECINFO",
+		.op_rsize_bop = nfsd4_secinfo_rsize,
+	},
+	[OP_SETATTR] = {
+		.op_func = nfsd4_setattr,
+		.op_name = "OP_SETATTR",
+		.op_flags = OP_MODIFIES_SOMETHING | OP_CACHEME
+				| OP_NONTRIVIAL_ERROR_ENCODE,
+		.op_rsize_bop = nfsd4_setattr_rsize,
+		.op_get_currentstateid = nfsd4_get_setattrstateid,
+	},
+	[OP_SETCLIENTID] = {
+		.op_func = nfsd4_setclientid,
+		.op_flags = ALLOWED_WITHOUT_FH | ALLOWED_ON_ABSENT_FS
+				| OP_MODIFIES_SOMETHING | OP_CACHEME
+				| OP_NONTRIVIAL_ERROR_ENCODE,
+		.op_name = "OP_SETCLIENTID",
+		.op_rsize_bop = nfsd4_setclientid_rsize,
+	},
+	[OP_SETCLIENTID_CONFIRM] = {
+		.op_func = nfsd4_setclientid_confirm,
+		.op_flags = ALLOWED_WITHOUT_FH | ALLOWED_ON_ABSENT_FS
+				| OP_MODIFIES_SOMETHING | OP_CACHEME,
+		.op_name = "OP_SETCLIENTID_CONFIRM",
+		.op_rsize_bop = nfsd4_only_status_rsize,
+	},
+	[OP_VERIFY] = {
+		.op_func = nfsd4_verify,
+		.op_name = "OP_VERIFY",
+		.op_rsize_bop = nfsd4_only_status_rsize,
+	},
+	[OP_WRITE] = {
+		.op_func = nfsd4_write,
+		.op_flags = OP_MODIFIES_SOMETHING | OP_CACHEME,
+		.op_name = "OP_WRITE",
+		.op_rsize_bop = nfsd4_write_rsize,
+		.op_get_currentstateid = nfsd4_get_writestateid,
+	},
+	[OP_RELEASE_LOCKOWNER] = {
+		.op_func = nfsd4_release_lockowner,
+		.op_flags = ALLOWED_WITHOUT_FH | ALLOWED_ON_ABSENT_FS
+				| OP_MODIFIES_SOMETHING,
+		.op_name = "OP_RELEASE_LOCKOWNER",
+		.op_rsize_bop = nfsd4_only_status_rsize,
+	},
+
+	/* NFSv4.1 operations */
+	[OP_EXCHANGE_ID] = {
+		.op_func = nfsd4_exchange_id,
+		.op_flags = ALLOWED_WITHOUT_FH | ALLOWED_AS_FIRST_OP
+				| OP_MODIFIES_SOMETHING,
+		.op_name = "OP_EXCHANGE_ID",
+		.op_rsize_bop = nfsd4_exchange_id_rsize,
+	},
+	[OP_BACKCHANNEL_CTL] = {
+		.op_func = nfsd4_backchannel_ctl,
+		.op_flags = ALLOWED_WITHOUT_FH | OP_MODIFIES_SOMETHING,
+		.op_name = "OP_BACKCHANNEL_CTL",
+		.op_rsize_bop = nfsd4_only_status_rsize,
+	},
+	[OP_BIND_CONN_TO_SESSION] = {
+		.op_func = nfsd4_bind_conn_to_session,
+		.op_flags = ALLOWED_WITHOUT_FH | ALLOWED_AS_FIRST_OP
+				| OP_MODIFIES_SOMETHING,
+		.op_name = "OP_BIND_CONN_TO_SESSION",
+		.op_rsize_bop = nfsd4_bind_conn_to_session_rsize,
+	},
+	[OP_CREATE_SESSION] = {
+		.op_func = nfsd4_create_session,
+		.op_flags = ALLOWED_WITHOUT_FH | ALLOWED_AS_FIRST_OP
+				| OP_MODIFIES_SOMETHING,
+		.op_name = "OP_CREATE_SESSION",
+		.op_rsize_bop = nfsd4_create_session_rsize,
+	},
+	[OP_DESTROY_SESSION] = {
+		.op_func = nfsd4_destroy_session,
+		.op_flags = ALLOWED_WITHOUT_FH | ALLOWED_AS_FIRST_OP
+				| OP_MODIFIES_SOMETHING,
+		.op_name = "OP_DESTROY_SESSION",
+		.op_rsize_bop = nfsd4_only_status_rsize,
+	},
+	[OP_SEQUENCE] = {
+		.op_func = nfsd4_sequence,
+		.op_flags = ALLOWED_WITHOUT_FH | ALLOWED_AS_FIRST_OP,
+		.op_name = "OP_SEQUENCE",
+		.op_rsize_bop = nfsd4_sequence_rsize,
+	},
+	[OP_DESTROY_CLIENTID] = {
+		.op_func = nfsd4_destroy_clientid,
+		.op_flags = ALLOWED_WITHOUT_FH | ALLOWED_AS_FIRST_OP
+				| OP_MODIFIES_SOMETHING,
+		.op_name = "OP_DESTROY_CLIENTID",
+		.op_rsize_bop = nfsd4_only_status_rsize,
+	},
+	[OP_RECLAIM_COMPLETE] = {
+		.op_func = nfsd4_reclaim_complete,
+		.op_flags = ALLOWED_WITHOUT_FH | OP_MODIFIES_SOMETHING,
+		.op_name = "OP_RECLAIM_COMPLETE",
+		.op_rsize_bop = nfsd4_only_status_rsize,
+	},
+	[OP_SECINFO_NO_NAME] = {
+		.op_func = nfsd4_secinfo_no_name,
+		.op_release = nfsd4_secinfo_no_name_release,
+		.op_flags = OP_HANDLES_WRONGSEC,
+		.op_name = "OP_SECINFO_NO_NAME",
+		.op_rsize_bop = nfsd4_secinfo_rsize,
+	},
+	[OP_TEST_STATEID] = {
+		.op_func = nfsd4_test_stateid,
+		.op_flags = ALLOWED_WITHOUT_FH,
+		.op_name = "OP_TEST_STATEID",
+		.op_rsize_bop = nfsd4_test_stateid_rsize,
+	},
+	[OP_FREE_STATEID] = {
+		.op_func = nfsd4_free_stateid,
+		.op_flags = ALLOWED_WITHOUT_FH | OP_MODIFIES_SOMETHING,
+		.op_name = "OP_FREE_STATEID",
+		.op_get_currentstateid = nfsd4_get_freestateid,
+		.op_rsize_bop = nfsd4_only_status_rsize,
+	},
+#ifdef CONFIG_NFSD_PNFS
+	[OP_GETDEVICEINFO] = {
+		.op_func = nfsd4_getdeviceinfo,
+		.op_release = nfsd4_getdeviceinfo_release,
+		.op_flags = ALLOWED_WITHOUT_FH,
+		.op_name = "OP_GETDEVICEINFO",
+		.op_rsize_bop = nfsd4_getdeviceinfo_rsize,
+	},
+	[OP_LAYOUTGET] = {
+		.op_func = nfsd4_layoutget,
+		.op_release = nfsd4_layoutget_release,
+		.op_flags = OP_MODIFIES_SOMETHING,
+		.op_name = "OP_LAYOUTGET",
+		.op_rsize_bop = nfsd4_layoutget_rsize,
+	},
+	[OP_LAYOUTCOMMIT] = {
+		.op_func = nfsd4_layoutcommit,
+		.op_flags = OP_MODIFIES_SOMETHING,
+		.op_name = "OP_LAYOUTCOMMIT",
+		.op_rsize_bop = nfsd4_layoutcommit_rsize,
+	},
+	[OP_LAYOUTRETURN] = {
+		.op_func = nfsd4_layoutreturn,
+		.op_flags = OP_MODIFIES_SOMETHING,
+		.op_name = "OP_LAYOUTRETURN",
+		.op_rsize_bop = nfsd4_layoutreturn_rsize,
+	},
+#endif /* CONFIG_NFSD_PNFS */
+
+	/* NFSv4.2 operations */
+	[OP_ALLOCATE] = {
+		.op_func = nfsd4_allocate,
+		.op_flags = OP_MODIFIES_SOMETHING,
+		.op_name = "OP_ALLOCATE",
+		.op_rsize_bop = nfsd4_only_status_rsize,
+	},
+	[OP_DEALLOCATE] = {
+		.op_func = nfsd4_deallocate,
+		.op_flags = OP_MODIFIES_SOMETHING,
+		.op_name = "OP_DEALLOCATE",
+		.op_rsize_bop = nfsd4_only_status_rsize,
+	},
+	[OP_CLONE] = {
+		.op_func = nfsd4_clone,
+		.op_flags = OP_MODIFIES_SOMETHING,
+		.op_name = "OP_CLONE",
+		.op_rsize_bop = nfsd4_only_status_rsize,
+	},
+	[OP_COPY] = {
+		.op_func = nfsd4_copy,
+		.op_flags = OP_MODIFIES_SOMETHING,
+		.op_name = "OP_COPY",
+		.op_rsize_bop = nfsd4_copy_rsize,
+	},
+	[OP_READ_PLUS] = {
+		.op_func = nfsd4_read,
+		.op_release = nfsd4_read_release,
+		.op_name = "OP_READ_PLUS",
+		.op_rsize_bop = nfsd4_read_plus_rsize,
+		.op_get_currentstateid = nfsd4_get_readstateid,
+	},
+	[OP_SEEK] = {
+		.op_func = nfsd4_seek,
+		.op_name = "OP_SEEK",
+		.op_rsize_bop = nfsd4_seek_rsize,
+	},
+	[OP_OFFLOAD_STATUS] = {
+		.op_func = nfsd4_offload_status,
+		.op_name = "OP_OFFLOAD_STATUS",
+		.op_rsize_bop = nfsd4_offload_status_rsize,
+	},
+	[OP_OFFLOAD_CANCEL] = {
+		.op_func = nfsd4_offload_cancel,
+		.op_flags = OP_MODIFIES_SOMETHING,
+		.op_name = "OP_OFFLOAD_CANCEL",
+		.op_rsize_bop = nfsd4_only_status_rsize,
+	},
+	[OP_COPY_NOTIFY] = {
+		.op_func = nfsd4_copy_notify,
+		.op_flags = OP_MODIFIES_SOMETHING,
+		.op_name = "OP_COPY_NOTIFY",
+		.op_rsize_bop = nfsd4_copy_notify_rsize,
+	},
+	[OP_GETXATTR] = {
+		.op_func = nfsd4_getxattr,
+		.op_name = "OP_GETXATTR",
+		.op_rsize_bop = nfsd4_getxattr_rsize,
+	},
+	[OP_SETXATTR] = {
+		.op_func = nfsd4_setxattr,
+		.op_flags = OP_MODIFIES_SOMETHING | OP_CACHEME,
+		.op_name = "OP_SETXATTR",
+		.op_rsize_bop = nfsd4_setxattr_rsize,
+	},
+	[OP_LISTXATTRS] = {
+		.op_func = nfsd4_listxattrs,
+		.op_name = "OP_LISTXATTRS",
+		.op_rsize_bop = nfsd4_listxattrs_rsize,
+	},
+	[OP_REMOVEXATTR] = {
+		.op_func = nfsd4_removexattr,
+		.op_flags = OP_MODIFIES_SOMETHING | OP_CACHEME,
+		.op_name = "OP_REMOVEXATTR",
+		.op_rsize_bop = nfsd4_removexattr_rsize,
+	},
+};
+
+/**
+ * nfsd4_spo_must_allow - Determine if the compound op contains an
+ * operation that is allowed to be sent with machine credentials
+ *
+ * @rqstp: a pointer to the struct svc_rqst
+ *
+ * Checks to see if the compound contains a spo_must_allow op
+ * and confirms that it was sent with the proper machine creds.
+ */
+
+bool nfsd4_spo_must_allow(struct svc_rqst *rqstp)
+{
+	struct nfsd4_compoundres *resp = rqstp->rq_resp;
+	struct nfsd4_compoundargs *argp = rqstp->rq_argp;
+	struct nfsd4_op *this = &argp->ops[resp->opcnt - 1];
+	struct nfsd4_compound_state *cstate = &resp->cstate;
+	struct nfs4_op_map *allow = &cstate->clp->cl_spo_must_allow;
+	u32 opiter;
+
+	if (!cstate->minorversion)
+		return false;
+
+	if (cstate->spo_must_allowed)
+		return true;
+
+	opiter = resp->opcnt;
+	while (opiter < argp->opcnt) {
+		this = &argp->ops[opiter++];
+		if (test_bit(this->opnum, allow->u.longs) &&
+			cstate->clp->cl_mach_cred &&
+			nfsd4_mach_creds_match(cstate->clp, rqstp)) {
+			cstate->spo_must_allowed = true;
+			return true;
+		}
+	}
+	cstate->spo_must_allowed = false;
+	return false;
+}
+
+int nfsd4_max_reply(struct svc_rqst *rqstp, struct nfsd4_op *op)
+{
+	if (op->opnum == OP_ILLEGAL || op->status == nfserr_notsupp)
+		return op_encode_hdr_size * sizeof(__be32);
+
+	BUG_ON(OPDESC(op)->op_rsize_bop == NULL);
+	return OPDESC(op)->op_rsize_bop(rqstp, op);
+}
+
+void warn_on_nonidempotent_op(struct nfsd4_op *op)
+{
+	if (OPDESC(op)->op_flags & OP_MODIFIES_SOMETHING) {
+		pr_err("unable to encode reply to nonidempotent op %d (%s)\n",
+			op->opnum, nfsd4_op_name(op->opnum));
+		WARN_ON_ONCE(1);
+	}
+}
+
+static const char *nfsd4_op_name(unsigned opnum)
+{
+	if (opnum < ARRAY_SIZE(nfsd4_ops))
+		return nfsd4_ops[opnum].op_name;
+	return "unknown_operation";
+}
+
+#define nfsd4_voidres			nfsd4_voidargs
+struct nfsd4_voidargs { int dummy; };
+
+static const struct svc_procedure nfsd_procedures4[2] = {
+	[NFSPROC4_NULL] = {
+		.pc_func = nfsd4_proc_null,
+		.pc_decode = nfs4svc_decode_voidarg,
+		.pc_encode = nfs4svc_encode_voidres,
+		.pc_argsize = sizeof(struct nfsd4_voidargs),
+		.pc_ressize = sizeof(struct nfsd4_voidres),
+		.pc_cachetype = RC_NOCACHE,
+		.pc_xdrressize = 1,
+	},
+	[NFSPROC4_COMPOUND] = {
+		.pc_func = nfsd4_proc_compound,
+		.pc_decode = nfs4svc_decode_compoundargs,
+		.pc_encode = nfs4svc_encode_compoundres,
+		.pc_argsize = sizeof(struct nfsd4_compoundargs),
+		.pc_ressize = sizeof(struct nfsd4_compoundres),
+		.pc_release = nfsd4_release_compoundargs,
+		.pc_cachetype = RC_NOCACHE,
+		.pc_xdrressize = NFSD_BUFSIZE/4,
+	},
+};
+
+static unsigned int nfsd_count3[ARRAY_SIZE(nfsd_procedures4)];
+const struct svc_version nfsd_version4 = {
+	.vs_vers		= 4,
+	.vs_nproc		= 2,
+	.vs_proc		= nfsd_procedures4,
+	.vs_count		= nfsd_count3,
+	.vs_dispatch		= nfsd_dispatch,
+	.vs_xdrsize		= NFS4_SVC_XDRSIZE,
+	.vs_rpcb_optnl		= true,
+	.vs_need_cong_ctrl	= true,
+};
+
+/*
+ * Local variables:
+ *  c-basic-offset: 8
+ * End:
+ */
diff --git a/fs/nfsd/nfs4recover.c b/fs/nfsd/nfs4recover.c
new file mode 100644
index 000000000..83c4e6883
--- /dev/null
+++ b/fs/nfsd/nfs4recover.c
@@ -0,0 +1,2169 @@
+/*
+*  Copyright (c) 2004 The Regents of the University of Michigan.
+*  Copyright (c) 2012 Jeff Layton <jlayton@redhat.com>
+*  All rights reserved.
+*
+*  Andy Adamson <andros@citi.umich.edu>
+*
+*  Redistribution and use in source and binary forms, with or without
+*  modification, are permitted provided that the following conditions
+*  are met:
+*
+*  1. Redistributions of source code must retain the above copyright
+*     notice, this list of conditions and the following disclaimer.
+*  2. Redistributions in binary form must reproduce the above copyright
+*     notice, this list of conditions and the following disclaimer in the
+*     documentation and/or other materials provided with the distribution.
+*  3. Neither the name of the University nor the names of its
+*     contributors may be used to endorse or promote products derived
+*     from this software without specific prior written permission.
+*
+*  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
+*  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+*  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+*  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+*  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+*  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+*  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+*  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+*  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+*  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+*  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*
+*/
+
+#include <crypto/hash.h>
+#include <linux/file.h>
+#include <linux/slab.h>
+#include <linux/namei.h>
+#include <linux/sched.h>
+#include <linux/fs.h>
+#include <linux/module.h>
+#include <net/net_namespace.h>
+#include <linux/sunrpc/rpc_pipe_fs.h>
+#include <linux/sunrpc/clnt.h>
+#include <linux/nfsd/cld.h>
+
+#include "nfsd.h"
+#include "state.h"
+#include "vfs.h"
+#include "netns.h"
+
+#define NFSDDBG_FACILITY                NFSDDBG_PROC
+
+/* Declarations */
+struct nfsd4_client_tracking_ops {
+	int (*init)(struct net *);
+	void (*exit)(struct net *);
+	void (*create)(struct nfs4_client *);
+	void (*remove)(struct nfs4_client *);
+	int (*check)(struct nfs4_client *);
+	void (*grace_done)(struct nfsd_net *);
+	uint8_t version;
+	size_t msglen;
+};
+
+static const struct nfsd4_client_tracking_ops nfsd4_cld_tracking_ops;
+static const struct nfsd4_client_tracking_ops nfsd4_cld_tracking_ops_v2;
+
+/* Globals */
+static char user_recovery_dirname[PATH_MAX] = "/var/lib/nfs/v4recovery";
+
+static int
+nfs4_save_creds(const struct cred **original_creds)
+{
+	struct cred *new;
+
+	new = prepare_creds();
+	if (!new)
+		return -ENOMEM;
+
+	new->fsuid = GLOBAL_ROOT_UID;
+	new->fsgid = GLOBAL_ROOT_GID;
+	*original_creds = override_creds(new);
+	put_cred(new);
+	return 0;
+}
+
+static void
+nfs4_reset_creds(const struct cred *original)
+{
+	revert_creds(original);
+}
+
+static void
+md5_to_hex(char *out, char *md5)
+{
+	int i;
+
+	for (i=0; i<16; i++) {
+		unsigned char c = md5[i];
+
+		*out++ = '0' + ((c&0xf0)>>4) + (c>=0xa0)*('a'-'9'-1);
+		*out++ = '0' + (c&0x0f) + ((c&0x0f)>=0x0a)*('a'-'9'-1);
+	}
+	*out = '\0';
+}
+
+static int
+nfs4_make_rec_clidname(char *dname, const struct xdr_netobj *clname)
+{
+	struct xdr_netobj cksum;
+	struct crypto_shash *tfm;
+	int status;
+
+	dprintk("NFSD: nfs4_make_rec_clidname for %.*s\n",
+			clname->len, clname->data);
+	tfm = crypto_alloc_shash("md5", 0, 0);
+	if (IS_ERR(tfm)) {
+		status = PTR_ERR(tfm);
+		goto out_no_tfm;
+	}
+
+	cksum.len = crypto_shash_digestsize(tfm);
+	cksum.data = kmalloc(cksum.len, GFP_KERNEL);
+	if (cksum.data == NULL) {
+		status = -ENOMEM;
+ 		goto out;
+	}
+
+	status = crypto_shash_tfm_digest(tfm, clname->data, clname->len,
+					 cksum.data);
+	if (status)
+		goto out;
+
+	md5_to_hex(dname, cksum.data);
+
+	status = 0;
+out:
+	kfree(cksum.data);
+	crypto_free_shash(tfm);
+out_no_tfm:
+	return status;
+}
+
+/*
+ * If we had an error generating the recdir name for the legacy tracker
+ * then warn the admin. If the error doesn't appear to be transient,
+ * then disable recovery tracking.
+ */
+static void
+legacy_recdir_name_error(struct nfs4_client *clp, int error)
+{
+	printk(KERN_ERR "NFSD: unable to generate recoverydir "
+			"name (%d).\n", error);
+
+	/*
+	 * if the algorithm just doesn't exist, then disable the recovery
+	 * tracker altogether. The crypto libs will generally return this if
+	 * FIPS is enabled as well.
+	 */
+	if (error == -ENOENT) {
+		printk(KERN_ERR "NFSD: disabling legacy clientid tracking. "
+			"Reboot recovery will not function correctly!\n");
+		nfsd4_client_tracking_exit(clp->net);
+	}
+}
+
+static void
+__nfsd4_create_reclaim_record_grace(struct nfs4_client *clp,
+		const char *dname, int len, struct nfsd_net *nn)
+{
+	struct xdr_netobj name;
+	struct xdr_netobj princhash = { .len = 0, .data = NULL };
+	struct nfs4_client_reclaim *crp;
+
+	name.data = kmemdup(dname, len, GFP_KERNEL);
+	if (!name.data) {
+		dprintk("%s: failed to allocate memory for name.data!\n",
+			__func__);
+		return;
+	}
+	name.len = len;
+	crp = nfs4_client_to_reclaim(name, princhash, nn);
+	if (!crp) {
+		kfree(name.data);
+		return;
+	}
+	crp->cr_clp = clp;
+}
+
+static void
+nfsd4_create_clid_dir(struct nfs4_client *clp)
+{
+	const struct cred *original_cred;
+	char dname[HEXDIR_LEN];
+	struct dentry *dir, *dentry;
+	int status;
+	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+
+	if (test_and_set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
+		return;
+	if (!nn->rec_file)
+		return;
+
+	status = nfs4_make_rec_clidname(dname, &clp->cl_name);
+	if (status)
+		return legacy_recdir_name_error(clp, status);
+
+	status = nfs4_save_creds(&original_cred);
+	if (status < 0)
+		return;
+
+	status = mnt_want_write_file(nn->rec_file);
+	if (status)
+		goto out_creds;
+
+	dir = nn->rec_file->f_path.dentry;
+	/* lock the parent */
+	inode_lock(d_inode(dir));
+
+	dentry = lookup_one_len(dname, dir, HEXDIR_LEN-1);
+	if (IS_ERR(dentry)) {
+		status = PTR_ERR(dentry);
+		goto out_unlock;
+	}
+	if (d_really_is_positive(dentry))
+		/*
+		 * In the 4.1 case, where we're called from
+		 * reclaim_complete(), records from the previous reboot
+		 * may still be left, so this is OK.
+		 *
+		 * In the 4.0 case, we should never get here; but we may
+		 * as well be forgiving and just succeed silently.
+		 */
+		goto out_put;
+	status = vfs_mkdir(d_inode(dir), dentry, S_IRWXU);
+out_put:
+	dput(dentry);
+out_unlock:
+	inode_unlock(d_inode(dir));
+	if (status == 0) {
+		if (nn->in_grace)
+			__nfsd4_create_reclaim_record_grace(clp, dname,
+					HEXDIR_LEN, nn);
+		vfs_fsync(nn->rec_file, 0);
+	} else {
+		printk(KERN_ERR "NFSD: failed to write recovery record"
+				" (err %d); please check that %s exists"
+				" and is writeable", status,
+				user_recovery_dirname);
+	}
+	mnt_drop_write_file(nn->rec_file);
+out_creds:
+	nfs4_reset_creds(original_cred);
+}
+
+typedef int (recdir_func)(struct dentry *, struct dentry *, struct nfsd_net *);
+
+struct name_list {
+	char name[HEXDIR_LEN];
+	struct list_head list;
+};
+
+struct nfs4_dir_ctx {
+	struct dir_context ctx;
+	struct list_head names;
+};
+
+static int
+nfsd4_build_namelist(struct dir_context *__ctx, const char *name, int namlen,
+		loff_t offset, u64 ino, unsigned int d_type)
+{
+	struct nfs4_dir_ctx *ctx =
+		container_of(__ctx, struct nfs4_dir_ctx, ctx);
+	struct name_list *entry;
+
+	if (namlen != HEXDIR_LEN - 1)
+		return 0;
+	entry = kmalloc(sizeof(struct name_list), GFP_KERNEL);
+	if (entry == NULL)
+		return -ENOMEM;
+	memcpy(entry->name, name, HEXDIR_LEN - 1);
+	entry->name[HEXDIR_LEN - 1] = '\0';
+	list_add(&entry->list, &ctx->names);
+	return 0;
+}
+
+static int
+nfsd4_list_rec_dir(recdir_func *f, struct nfsd_net *nn)
+{
+	const struct cred *original_cred;
+	struct dentry *dir = nn->rec_file->f_path.dentry;
+	struct nfs4_dir_ctx ctx = {
+		.ctx.actor = nfsd4_build_namelist,
+		.names = LIST_HEAD_INIT(ctx.names)
+	};
+	struct name_list *entry, *tmp;
+	int status;
+
+	status = nfs4_save_creds(&original_cred);
+	if (status < 0)
+		return status;
+
+	status = vfs_llseek(nn->rec_file, 0, SEEK_SET);
+	if (status < 0) {
+		nfs4_reset_creds(original_cred);
+		return status;
+	}
+
+	status = iterate_dir(nn->rec_file, &ctx.ctx);
+	inode_lock_nested(d_inode(dir), I_MUTEX_PARENT);
+
+	list_for_each_entry_safe(entry, tmp, &ctx.names, list) {
+		if (!status) {
+			struct dentry *dentry;
+			dentry = lookup_one_len(entry->name, dir, HEXDIR_LEN-1);
+			if (IS_ERR(dentry)) {
+				status = PTR_ERR(dentry);
+				break;
+			}
+			status = f(dir, dentry, nn);
+			dput(dentry);
+		}
+		list_del(&entry->list);
+		kfree(entry);
+	}
+	inode_unlock(d_inode(dir));
+	nfs4_reset_creds(original_cred);
+
+	list_for_each_entry_safe(entry, tmp, &ctx.names, list) {
+		dprintk("NFSD: %s. Left entry %s\n", __func__, entry->name);
+		list_del(&entry->list);
+		kfree(entry);
+	}
+	return status;
+}
+
+static int
+nfsd4_unlink_clid_dir(char *name, int namlen, struct nfsd_net *nn)
+{
+	struct dentry *dir, *dentry;
+	int status;
+
+	dprintk("NFSD: nfsd4_unlink_clid_dir. name %.*s\n", namlen, name);
+
+	dir = nn->rec_file->f_path.dentry;
+	inode_lock_nested(d_inode(dir), I_MUTEX_PARENT);
+	dentry = lookup_one_len(name, dir, namlen);
+	if (IS_ERR(dentry)) {
+		status = PTR_ERR(dentry);
+		goto out_unlock;
+	}
+	status = -ENOENT;
+	if (d_really_is_negative(dentry))
+		goto out;
+	status = vfs_rmdir(d_inode(dir), dentry);
+out:
+	dput(dentry);
+out_unlock:
+	inode_unlock(d_inode(dir));
+	return status;
+}
+
+static void
+__nfsd4_remove_reclaim_record_grace(const char *dname, int len,
+		struct nfsd_net *nn)
+{
+	struct xdr_netobj name;
+	struct nfs4_client_reclaim *crp;
+
+	name.data = kmemdup(dname, len, GFP_KERNEL);
+	if (!name.data) {
+		dprintk("%s: failed to allocate memory for name.data!\n",
+			__func__);
+		return;
+	}
+	name.len = len;
+	crp = nfsd4_find_reclaim_client(name, nn);
+	kfree(name.data);
+	if (crp)
+		nfs4_remove_reclaim_record(crp, nn);
+}
+
+static void
+nfsd4_remove_clid_dir(struct nfs4_client *clp)
+{
+	const struct cred *original_cred;
+	char dname[HEXDIR_LEN];
+	int status;
+	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+
+	if (!nn->rec_file || !test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
+		return;
+
+	status = nfs4_make_rec_clidname(dname, &clp->cl_name);
+	if (status)
+		return legacy_recdir_name_error(clp, status);
+
+	status = mnt_want_write_file(nn->rec_file);
+	if (status)
+		goto out;
+	clear_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
+
+	status = nfs4_save_creds(&original_cred);
+	if (status < 0)
+		goto out_drop_write;
+
+	status = nfsd4_unlink_clid_dir(dname, HEXDIR_LEN-1, nn);
+	nfs4_reset_creds(original_cred);
+	if (status == 0) {
+		vfs_fsync(nn->rec_file, 0);
+		if (nn->in_grace)
+			__nfsd4_remove_reclaim_record_grace(dname,
+					HEXDIR_LEN, nn);
+	}
+out_drop_write:
+	mnt_drop_write_file(nn->rec_file);
+out:
+	if (status)
+		printk("NFSD: Failed to remove expired client state directory"
+				" %.*s\n", HEXDIR_LEN, dname);
+}
+
+static int
+purge_old(struct dentry *parent, struct dentry *child, struct nfsd_net *nn)
+{
+	int status;
+	struct xdr_netobj name;
+
+	if (child->d_name.len != HEXDIR_LEN - 1) {
+		printk("%s: illegal name %pd in recovery directory\n",
+				__func__, child);
+		/* Keep trying; maybe the others are OK: */
+		return 0;
+	}
+	name.data = kmemdup_nul(child->d_name.name, child->d_name.len, GFP_KERNEL);
+	if (!name.data) {
+		dprintk("%s: failed to allocate memory for name.data!\n",
+			__func__);
+		goto out;
+	}
+	name.len = HEXDIR_LEN;
+	if (nfs4_has_reclaimed_state(name, nn))
+		goto out_free;
+
+	status = vfs_rmdir(d_inode(parent), child);
+	if (status)
+		printk("failed to remove client recovery directory %pd\n",
+				child);
+out_free:
+	kfree(name.data);
+out:
+	/* Keep trying, success or failure: */
+	return 0;
+}
+
+static void
+nfsd4_recdir_purge_old(struct nfsd_net *nn)
+{
+	int status;
+
+	nn->in_grace = false;
+	if (!nn->rec_file)
+		return;
+	status = mnt_want_write_file(nn->rec_file);
+	if (status)
+		goto out;
+	status = nfsd4_list_rec_dir(purge_old, nn);
+	if (status == 0)
+		vfs_fsync(nn->rec_file, 0);
+	mnt_drop_write_file(nn->rec_file);
+out:
+	nfs4_release_reclaim(nn);
+	if (status)
+		printk("nfsd4: failed to purge old clients from recovery"
+			" directory %pD\n", nn->rec_file);
+}
+
+static int
+load_recdir(struct dentry *parent, struct dentry *child, struct nfsd_net *nn)
+{
+	struct xdr_netobj name;
+	struct xdr_netobj princhash = { .len = 0, .data = NULL };
+
+	if (child->d_name.len != HEXDIR_LEN - 1) {
+		printk("%s: illegal name %pd in recovery directory\n",
+				__func__, child);
+		/* Keep trying; maybe the others are OK: */
+		return 0;
+	}
+	name.data = kmemdup_nul(child->d_name.name, child->d_name.len, GFP_KERNEL);
+	if (!name.data) {
+		dprintk("%s: failed to allocate memory for name.data!\n",
+			__func__);
+		goto out;
+	}
+	name.len = HEXDIR_LEN;
+	if (!nfs4_client_to_reclaim(name, princhash, nn))
+		kfree(name.data);
+out:
+	return 0;
+}
+
+static int
+nfsd4_recdir_load(struct net *net) {
+	int status;
+	struct nfsd_net *nn =  net_generic(net, nfsd_net_id);
+
+	if (!nn->rec_file)
+		return 0;
+
+	status = nfsd4_list_rec_dir(load_recdir, nn);
+	if (status)
+		printk("nfsd4: failed loading clients from recovery"
+			" directory %pD\n", nn->rec_file);
+	return status;
+}
+
+/*
+ * Hold reference to the recovery directory.
+ */
+
+static int
+nfsd4_init_recdir(struct net *net)
+{
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+	const struct cred *original_cred;
+	int status;
+
+	printk("NFSD: Using %s as the NFSv4 state recovery directory\n",
+			user_recovery_dirname);
+
+	BUG_ON(nn->rec_file);
+
+	status = nfs4_save_creds(&original_cred);
+	if (status < 0) {
+		printk("NFSD: Unable to change credentials to find recovery"
+		       " directory: error %d\n",
+		       status);
+		return status;
+	}
+
+	nn->rec_file = filp_open(user_recovery_dirname, O_RDONLY | O_DIRECTORY, 0);
+	if (IS_ERR(nn->rec_file)) {
+		printk("NFSD: unable to find recovery directory %s\n",
+				user_recovery_dirname);
+		status = PTR_ERR(nn->rec_file);
+		nn->rec_file = NULL;
+	}
+
+	nfs4_reset_creds(original_cred);
+	if (!status)
+		nn->in_grace = true;
+	return status;
+}
+
+static void
+nfsd4_shutdown_recdir(struct net *net)
+{
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	if (!nn->rec_file)
+		return;
+	fput(nn->rec_file);
+	nn->rec_file = NULL;
+}
+
+static int
+nfs4_legacy_state_init(struct net *net)
+{
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+	int i;
+
+	nn->reclaim_str_hashtbl = kmalloc_array(CLIENT_HASH_SIZE,
+						sizeof(struct list_head),
+						GFP_KERNEL);
+	if (!nn->reclaim_str_hashtbl)
+		return -ENOMEM;
+
+	for (i = 0; i < CLIENT_HASH_SIZE; i++)
+		INIT_LIST_HEAD(&nn->reclaim_str_hashtbl[i]);
+	nn->reclaim_str_hashtbl_size = 0;
+
+	return 0;
+}
+
+static void
+nfs4_legacy_state_shutdown(struct net *net)
+{
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	kfree(nn->reclaim_str_hashtbl);
+}
+
+static int
+nfsd4_load_reboot_recovery_data(struct net *net)
+{
+	int status;
+
+	status = nfsd4_init_recdir(net);
+	if (status)
+		return status;
+
+	status = nfsd4_recdir_load(net);
+	if (status)
+		nfsd4_shutdown_recdir(net);
+
+	return status;
+}
+
+static int
+nfsd4_legacy_tracking_init(struct net *net)
+{
+	int status;
+
+	/* XXX: The legacy code won't work in a container */
+	if (net != &init_net) {
+		pr_warn("NFSD: attempt to initialize legacy client tracking in a container ignored.\n");
+		return -EINVAL;
+	}
+
+	status = nfs4_legacy_state_init(net);
+	if (status)
+		return status;
+
+	status = nfsd4_load_reboot_recovery_data(net);
+	if (status)
+		goto err;
+	printk("NFSD: Using legacy client tracking operations.\n");
+	return 0;
+
+err:
+	nfs4_legacy_state_shutdown(net);
+	return status;
+}
+
+static void
+nfsd4_legacy_tracking_exit(struct net *net)
+{
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	nfs4_release_reclaim(nn);
+	nfsd4_shutdown_recdir(net);
+	nfs4_legacy_state_shutdown(net);
+}
+
+/*
+ * Change the NFSv4 recovery directory to recdir.
+ */
+int
+nfs4_reset_recoverydir(char *recdir)
+{
+	int status;
+	struct path path;
+
+	status = kern_path(recdir, LOOKUP_FOLLOW, &path);
+	if (status)
+		return status;
+	status = -ENOTDIR;
+	if (d_is_dir(path.dentry)) {
+		strcpy(user_recovery_dirname, recdir);
+		status = 0;
+	}
+	path_put(&path);
+	return status;
+}
+
+char *
+nfs4_recoverydir(void)
+{
+	return user_recovery_dirname;
+}
+
+static int
+nfsd4_check_legacy_client(struct nfs4_client *clp)
+{
+	int status;
+	char dname[HEXDIR_LEN];
+	struct nfs4_client_reclaim *crp;
+	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+	struct xdr_netobj name;
+
+	/* did we already find that this client is stable? */
+	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
+		return 0;
+
+	status = nfs4_make_rec_clidname(dname, &clp->cl_name);
+	if (status) {
+		legacy_recdir_name_error(clp, status);
+		return status;
+	}
+
+	/* look for it in the reclaim hashtable otherwise */
+	name.data = kmemdup(dname, HEXDIR_LEN, GFP_KERNEL);
+	if (!name.data) {
+		dprintk("%s: failed to allocate memory for name.data!\n",
+			__func__);
+		goto out_enoent;
+	}
+	name.len = HEXDIR_LEN;
+	crp = nfsd4_find_reclaim_client(name, nn);
+	kfree(name.data);
+	if (crp) {
+		set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
+		crp->cr_clp = clp;
+		return 0;
+	}
+
+out_enoent:
+	return -ENOENT;
+}
+
+static const struct nfsd4_client_tracking_ops nfsd4_legacy_tracking_ops = {
+	.init		= nfsd4_legacy_tracking_init,
+	.exit		= nfsd4_legacy_tracking_exit,
+	.create		= nfsd4_create_clid_dir,
+	.remove		= nfsd4_remove_clid_dir,
+	.check		= nfsd4_check_legacy_client,
+	.grace_done	= nfsd4_recdir_purge_old,
+	.version	= 1,
+	.msglen		= 0,
+};
+
+/* Globals */
+#define NFSD_PIPE_DIR		"nfsd"
+#define NFSD_CLD_PIPE		"cld"
+
+/* per-net-ns structure for holding cld upcall info */
+struct cld_net {
+	struct rpc_pipe		*cn_pipe;
+	spinlock_t		 cn_lock;
+	struct list_head	 cn_list;
+	unsigned int		 cn_xid;
+	bool			 cn_has_legacy;
+	struct crypto_shash	*cn_tfm;
+};
+
+struct cld_upcall {
+	struct list_head	 cu_list;
+	struct cld_net		*cu_net;
+	struct completion	 cu_done;
+	union {
+		struct cld_msg_hdr	 cu_hdr;
+		struct cld_msg		 cu_msg;
+		struct cld_msg_v2	 cu_msg_v2;
+	} cu_u;
+};
+
+static int
+__cld_pipe_upcall(struct rpc_pipe *pipe, void *cmsg, struct nfsd_net *nn)
+{
+	int ret;
+	struct rpc_pipe_msg msg;
+	struct cld_upcall *cup = container_of(cmsg, struct cld_upcall, cu_u);
+
+	memset(&msg, 0, sizeof(msg));
+	msg.data = cmsg;
+	msg.len = nn->client_tracking_ops->msglen;
+
+	ret = rpc_queue_upcall(pipe, &msg);
+	if (ret < 0) {
+		goto out;
+	}
+
+	wait_for_completion(&cup->cu_done);
+
+	if (msg.errno < 0)
+		ret = msg.errno;
+out:
+	return ret;
+}
+
+static int
+cld_pipe_upcall(struct rpc_pipe *pipe, void *cmsg, struct nfsd_net *nn)
+{
+	int ret;
+
+	/*
+	 * -EAGAIN occurs when pipe is closed and reopened while there are
+	 *  upcalls queued.
+	 */
+	do {
+		ret = __cld_pipe_upcall(pipe, cmsg, nn);
+	} while (ret == -EAGAIN);
+
+	return ret;
+}
+
+static ssize_t
+__cld_pipe_inprogress_downcall(const struct cld_msg_v2 __user *cmsg,
+		struct nfsd_net *nn)
+{
+	uint8_t cmd, princhashlen;
+	struct xdr_netobj name, princhash = { .len = 0, .data = NULL };
+	uint16_t namelen;
+	struct cld_net *cn = nn->cld_net;
+
+	if (get_user(cmd, &cmsg->cm_cmd)) {
+		dprintk("%s: error when copying cmd from userspace", __func__);
+		return -EFAULT;
+	}
+	if (cmd == Cld_GraceStart) {
+		if (nn->client_tracking_ops->version >= 2) {
+			const struct cld_clntinfo __user *ci;
+
+			ci = &cmsg->cm_u.cm_clntinfo;
+			if (get_user(namelen, &ci->cc_name.cn_len))
+				return -EFAULT;
+			name.data = memdup_user(&ci->cc_name.cn_id, namelen);
+			if (IS_ERR_OR_NULL(name.data))
+				return -EFAULT;
+			name.len = namelen;
+			get_user(princhashlen, &ci->cc_princhash.cp_len);
+			if (princhashlen > 0) {
+				princhash.data = memdup_user(
+						&ci->cc_princhash.cp_data,
+						princhashlen);
+				if (IS_ERR_OR_NULL(princhash.data)) {
+					kfree(name.data);
+					return -EFAULT;
+				}
+				princhash.len = princhashlen;
+			} else
+				princhash.len = 0;
+		} else {
+			const struct cld_name __user *cnm;
+
+			cnm = &cmsg->cm_u.cm_name;
+			if (get_user(namelen, &cnm->cn_len))
+				return -EFAULT;
+			name.data = memdup_user(&cnm->cn_id, namelen);
+			if (IS_ERR_OR_NULL(name.data))
+				return -EFAULT;
+			name.len = namelen;
+		}
+		if (name.len > 5 && memcmp(name.data, "hash:", 5) == 0) {
+			name.len = name.len - 5;
+			memmove(name.data, name.data + 5, name.len);
+			cn->cn_has_legacy = true;
+		}
+		if (!nfs4_client_to_reclaim(name, princhash, nn)) {
+			kfree(name.data);
+			kfree(princhash.data);
+			return -EFAULT;
+		}
+		return nn->client_tracking_ops->msglen;
+	}
+	return -EFAULT;
+}
+
+static ssize_t
+cld_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
+{
+	struct cld_upcall *tmp, *cup;
+	struct cld_msg_hdr __user *hdr = (struct cld_msg_hdr __user *)src;
+	struct cld_msg_v2 __user *cmsg = (struct cld_msg_v2 __user *)src;
+	uint32_t xid;
+	struct nfsd_net *nn = net_generic(file_inode(filp)->i_sb->s_fs_info,
+						nfsd_net_id);
+	struct cld_net *cn = nn->cld_net;
+	int16_t status;
+
+	if (mlen != nn->client_tracking_ops->msglen) {
+		dprintk("%s: got %zu bytes, expected %zu\n", __func__, mlen,
+			nn->client_tracking_ops->msglen);
+		return -EINVAL;
+	}
+
+	/* copy just the xid so we can try to find that */
+	if (copy_from_user(&xid, &hdr->cm_xid, sizeof(xid)) != 0) {
+		dprintk("%s: error when copying xid from userspace", __func__);
+		return -EFAULT;
+	}
+
+	/*
+	 * copy the status so we know whether to remove the upcall from the
+	 * list (for -EINPROGRESS, we just want to make sure the xid is
+	 * valid, not remove the upcall from the list)
+	 */
+	if (get_user(status, &hdr->cm_status)) {
+		dprintk("%s: error when copying status from userspace", __func__);
+		return -EFAULT;
+	}
+
+	/* walk the list and find corresponding xid */
+	cup = NULL;
+	spin_lock(&cn->cn_lock);
+	list_for_each_entry(tmp, &cn->cn_list, cu_list) {
+		if (get_unaligned(&tmp->cu_u.cu_hdr.cm_xid) == xid) {
+			cup = tmp;
+			if (status != -EINPROGRESS)
+				list_del_init(&cup->cu_list);
+			break;
+		}
+	}
+	spin_unlock(&cn->cn_lock);
+
+	/* couldn't find upcall? */
+	if (!cup) {
+		dprintk("%s: couldn't find upcall -- xid=%u\n", __func__, xid);
+		return -EINVAL;
+	}
+
+	if (status == -EINPROGRESS)
+		return __cld_pipe_inprogress_downcall(cmsg, nn);
+
+	if (copy_from_user(&cup->cu_u.cu_msg_v2, src, mlen) != 0)
+		return -EFAULT;
+
+	complete(&cup->cu_done);
+	return mlen;
+}
+
+static void
+cld_pipe_destroy_msg(struct rpc_pipe_msg *msg)
+{
+	struct cld_msg *cmsg = msg->data;
+	struct cld_upcall *cup = container_of(cmsg, struct cld_upcall,
+						 cu_u.cu_msg);
+
+	/* errno >= 0 means we got a downcall */
+	if (msg->errno >= 0)
+		return;
+
+	complete(&cup->cu_done);
+}
+
+static const struct rpc_pipe_ops cld_upcall_ops = {
+	.upcall		= rpc_pipe_generic_upcall,
+	.downcall	= cld_pipe_downcall,
+	.destroy_msg	= cld_pipe_destroy_msg,
+};
+
+static struct dentry *
+nfsd4_cld_register_sb(struct super_block *sb, struct rpc_pipe *pipe)
+{
+	struct dentry *dir, *dentry;
+
+	dir = rpc_d_lookup_sb(sb, NFSD_PIPE_DIR);
+	if (dir == NULL)
+		return ERR_PTR(-ENOENT);
+	dentry = rpc_mkpipe_dentry(dir, NFSD_CLD_PIPE, NULL, pipe);
+	dput(dir);
+	return dentry;
+}
+
+static void
+nfsd4_cld_unregister_sb(struct rpc_pipe *pipe)
+{
+	if (pipe->dentry)
+		rpc_unlink(pipe->dentry);
+}
+
+static struct dentry *
+nfsd4_cld_register_net(struct net *net, struct rpc_pipe *pipe)
+{
+	struct super_block *sb;
+	struct dentry *dentry;
+
+	sb = rpc_get_sb_net(net);
+	if (!sb)
+		return NULL;
+	dentry = nfsd4_cld_register_sb(sb, pipe);
+	rpc_put_sb_net(net);
+	return dentry;
+}
+
+static void
+nfsd4_cld_unregister_net(struct net *net, struct rpc_pipe *pipe)
+{
+	struct super_block *sb;
+
+	sb = rpc_get_sb_net(net);
+	if (sb) {
+		nfsd4_cld_unregister_sb(pipe);
+		rpc_put_sb_net(net);
+	}
+}
+
+/* Initialize rpc_pipefs pipe for communication with client tracking daemon */
+static int
+__nfsd4_init_cld_pipe(struct net *net)
+{
+	int ret;
+	struct dentry *dentry;
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+	struct cld_net *cn;
+
+	if (nn->cld_net)
+		return 0;
+
+	cn = kzalloc(sizeof(*cn), GFP_KERNEL);
+	if (!cn) {
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	cn->cn_pipe = rpc_mkpipe_data(&cld_upcall_ops, RPC_PIPE_WAIT_FOR_OPEN);
+	if (IS_ERR(cn->cn_pipe)) {
+		ret = PTR_ERR(cn->cn_pipe);
+		goto err;
+	}
+	spin_lock_init(&cn->cn_lock);
+	INIT_LIST_HEAD(&cn->cn_list);
+
+	dentry = nfsd4_cld_register_net(net, cn->cn_pipe);
+	if (IS_ERR(dentry)) {
+		ret = PTR_ERR(dentry);
+		goto err_destroy_data;
+	}
+
+	cn->cn_pipe->dentry = dentry;
+	cn->cn_has_legacy = false;
+	nn->cld_net = cn;
+	return 0;
+
+err_destroy_data:
+	rpc_destroy_pipe_data(cn->cn_pipe);
+err:
+	kfree(cn);
+	printk(KERN_ERR "NFSD: unable to create nfsdcld upcall pipe (%d)\n",
+			ret);
+	return ret;
+}
+
+static int
+nfsd4_init_cld_pipe(struct net *net)
+{
+	int status;
+
+	status = __nfsd4_init_cld_pipe(net);
+	if (!status)
+		printk("NFSD: Using old nfsdcld client tracking operations.\n");
+	return status;
+}
+
+static void
+nfsd4_remove_cld_pipe(struct net *net)
+{
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+	struct cld_net *cn = nn->cld_net;
+
+	nfsd4_cld_unregister_net(net, cn->cn_pipe);
+	rpc_destroy_pipe_data(cn->cn_pipe);
+	if (cn->cn_tfm)
+		crypto_free_shash(cn->cn_tfm);
+	kfree(nn->cld_net);
+	nn->cld_net = NULL;
+}
+
+static struct cld_upcall *
+alloc_cld_upcall(struct nfsd_net *nn)
+{
+	struct cld_upcall *new, *tmp;
+	struct cld_net *cn = nn->cld_net;
+
+	new = kzalloc(sizeof(*new), GFP_KERNEL);
+	if (!new)
+		return new;
+
+	/* FIXME: hard cap on number in flight? */
+restart_search:
+	spin_lock(&cn->cn_lock);
+	list_for_each_entry(tmp, &cn->cn_list, cu_list) {
+		if (tmp->cu_u.cu_msg.cm_xid == cn->cn_xid) {
+			cn->cn_xid++;
+			spin_unlock(&cn->cn_lock);
+			goto restart_search;
+		}
+	}
+	init_completion(&new->cu_done);
+	new->cu_u.cu_msg.cm_vers = nn->client_tracking_ops->version;
+	put_unaligned(cn->cn_xid++, &new->cu_u.cu_msg.cm_xid);
+	new->cu_net = cn;
+	list_add(&new->cu_list, &cn->cn_list);
+	spin_unlock(&cn->cn_lock);
+
+	dprintk("%s: allocated xid %u\n", __func__, new->cu_u.cu_msg.cm_xid);
+
+	return new;
+}
+
+static void
+free_cld_upcall(struct cld_upcall *victim)
+{
+	struct cld_net *cn = victim->cu_net;
+
+	spin_lock(&cn->cn_lock);
+	list_del(&victim->cu_list);
+	spin_unlock(&cn->cn_lock);
+	kfree(victim);
+}
+
+/* Ask daemon to create a new record */
+static void
+nfsd4_cld_create(struct nfs4_client *clp)
+{
+	int ret;
+	struct cld_upcall *cup;
+	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+	struct cld_net *cn = nn->cld_net;
+
+	/* Don't upcall if it's already stored */
+	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
+		return;
+
+	cup = alloc_cld_upcall(nn);
+	if (!cup) {
+		ret = -ENOMEM;
+		goto out_err;
+	}
+
+	cup->cu_u.cu_msg.cm_cmd = Cld_Create;
+	cup->cu_u.cu_msg.cm_u.cm_name.cn_len = clp->cl_name.len;
+	memcpy(cup->cu_u.cu_msg.cm_u.cm_name.cn_id, clp->cl_name.data,
+			clp->cl_name.len);
+
+	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg, nn);
+	if (!ret) {
+		ret = cup->cu_u.cu_msg.cm_status;
+		set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
+	}
+
+	free_cld_upcall(cup);
+out_err:
+	if (ret)
+		printk(KERN_ERR "NFSD: Unable to create client "
+				"record on stable storage: %d\n", ret);
+}
+
+/* Ask daemon to create a new record */
+static void
+nfsd4_cld_create_v2(struct nfs4_client *clp)
+{
+	int ret;
+	struct cld_upcall *cup;
+	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+	struct cld_net *cn = nn->cld_net;
+	struct cld_msg_v2 *cmsg;
+	struct crypto_shash *tfm = cn->cn_tfm;
+	struct xdr_netobj cksum;
+	char *principal = NULL;
+
+	/* Don't upcall if it's already stored */
+	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
+		return;
+
+	cup = alloc_cld_upcall(nn);
+	if (!cup) {
+		ret = -ENOMEM;
+		goto out_err;
+	}
+
+	cmsg = &cup->cu_u.cu_msg_v2;
+	cmsg->cm_cmd = Cld_Create;
+	cmsg->cm_u.cm_clntinfo.cc_name.cn_len = clp->cl_name.len;
+	memcpy(cmsg->cm_u.cm_clntinfo.cc_name.cn_id, clp->cl_name.data,
+			clp->cl_name.len);
+	if (clp->cl_cred.cr_raw_principal)
+		principal = clp->cl_cred.cr_raw_principal;
+	else if (clp->cl_cred.cr_principal)
+		principal = clp->cl_cred.cr_principal;
+	if (principal) {
+		cksum.len = crypto_shash_digestsize(tfm);
+		cksum.data = kmalloc(cksum.len, GFP_KERNEL);
+		if (cksum.data == NULL) {
+			ret = -ENOMEM;
+			goto out;
+		}
+		ret = crypto_shash_tfm_digest(tfm, principal, strlen(principal),
+					      cksum.data);
+		if (ret) {
+			kfree(cksum.data);
+			goto out;
+		}
+		cmsg->cm_u.cm_clntinfo.cc_princhash.cp_len = cksum.len;
+		memcpy(cmsg->cm_u.cm_clntinfo.cc_princhash.cp_data,
+		       cksum.data, cksum.len);
+		kfree(cksum.data);
+	} else
+		cmsg->cm_u.cm_clntinfo.cc_princhash.cp_len = 0;
+
+	ret = cld_pipe_upcall(cn->cn_pipe, cmsg, nn);
+	if (!ret) {
+		ret = cmsg->cm_status;
+		set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
+	}
+
+out:
+	free_cld_upcall(cup);
+out_err:
+	if (ret)
+		pr_err("NFSD: Unable to create client record on stable storage: %d\n",
+				ret);
+}
+
+/* Ask daemon to create a new record */
+static void
+nfsd4_cld_remove(struct nfs4_client *clp)
+{
+	int ret;
+	struct cld_upcall *cup;
+	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+	struct cld_net *cn = nn->cld_net;
+
+	/* Don't upcall if it's already removed */
+	if (!test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
+		return;
+
+	cup = alloc_cld_upcall(nn);
+	if (!cup) {
+		ret = -ENOMEM;
+		goto out_err;
+	}
+
+	cup->cu_u.cu_msg.cm_cmd = Cld_Remove;
+	cup->cu_u.cu_msg.cm_u.cm_name.cn_len = clp->cl_name.len;
+	memcpy(cup->cu_u.cu_msg.cm_u.cm_name.cn_id, clp->cl_name.data,
+			clp->cl_name.len);
+
+	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg, nn);
+	if (!ret) {
+		ret = cup->cu_u.cu_msg.cm_status;
+		clear_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
+	}
+
+	free_cld_upcall(cup);
+out_err:
+	if (ret)
+		printk(KERN_ERR "NFSD: Unable to remove client "
+				"record from stable storage: %d\n", ret);
+}
+
+/*
+ * For older nfsdcld's that do not allow us to "slurp" the clients
+ * from the tracking database during startup.
+ *
+ * Check for presence of a record, and update its timestamp
+ */
+static int
+nfsd4_cld_check_v0(struct nfs4_client *clp)
+{
+	int ret;
+	struct cld_upcall *cup;
+	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+	struct cld_net *cn = nn->cld_net;
+
+	/* Don't upcall if one was already stored during this grace pd */
+	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
+		return 0;
+
+	cup = alloc_cld_upcall(nn);
+	if (!cup) {
+		printk(KERN_ERR "NFSD: Unable to check client record on "
+				"stable storage: %d\n", -ENOMEM);
+		return -ENOMEM;
+	}
+
+	cup->cu_u.cu_msg.cm_cmd = Cld_Check;
+	cup->cu_u.cu_msg.cm_u.cm_name.cn_len = clp->cl_name.len;
+	memcpy(cup->cu_u.cu_msg.cm_u.cm_name.cn_id, clp->cl_name.data,
+			clp->cl_name.len);
+
+	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg, nn);
+	if (!ret) {
+		ret = cup->cu_u.cu_msg.cm_status;
+		set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
+	}
+
+	free_cld_upcall(cup);
+	return ret;
+}
+
+/*
+ * For newer nfsdcld's that allow us to "slurp" the clients
+ * from the tracking database during startup.
+ *
+ * Check for presence of a record in the reclaim_str_hashtbl
+ */
+static int
+nfsd4_cld_check(struct nfs4_client *clp)
+{
+	struct nfs4_client_reclaim *crp;
+	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+	struct cld_net *cn = nn->cld_net;
+	int status;
+	char dname[HEXDIR_LEN];
+	struct xdr_netobj name;
+
+	/* did we already find that this client is stable? */
+	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
+		return 0;
+
+	/* look for it in the reclaim hashtable otherwise */
+	crp = nfsd4_find_reclaim_client(clp->cl_name, nn);
+	if (crp)
+		goto found;
+
+	if (cn->cn_has_legacy) {
+		status = nfs4_make_rec_clidname(dname, &clp->cl_name);
+		if (status)
+			return -ENOENT;
+
+		name.data = kmemdup(dname, HEXDIR_LEN, GFP_KERNEL);
+		if (!name.data) {
+			dprintk("%s: failed to allocate memory for name.data!\n",
+				__func__);
+			return -ENOENT;
+		}
+		name.len = HEXDIR_LEN;
+		crp = nfsd4_find_reclaim_client(name, nn);
+		kfree(name.data);
+		if (crp)
+			goto found;
+
+	}
+	return -ENOENT;
+found:
+	crp->cr_clp = clp;
+	return 0;
+}
+
+static int
+nfsd4_cld_check_v2(struct nfs4_client *clp)
+{
+	struct nfs4_client_reclaim *crp;
+	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+	struct cld_net *cn = nn->cld_net;
+	int status;
+	char dname[HEXDIR_LEN];
+	struct xdr_netobj name;
+	struct crypto_shash *tfm = cn->cn_tfm;
+	struct xdr_netobj cksum;
+	char *principal = NULL;
+
+	/* did we already find that this client is stable? */
+	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
+		return 0;
+
+	/* look for it in the reclaim hashtable otherwise */
+	crp = nfsd4_find_reclaim_client(clp->cl_name, nn);
+	if (crp)
+		goto found;
+
+	if (cn->cn_has_legacy) {
+		status = nfs4_make_rec_clidname(dname, &clp->cl_name);
+		if (status)
+			return -ENOENT;
+
+		name.data = kmemdup(dname, HEXDIR_LEN, GFP_KERNEL);
+		if (!name.data) {
+			dprintk("%s: failed to allocate memory for name.data\n",
+					__func__);
+			return -ENOENT;
+		}
+		name.len = HEXDIR_LEN;
+		crp = nfsd4_find_reclaim_client(name, nn);
+		kfree(name.data);
+		if (crp)
+			goto found;
+
+	}
+	return -ENOENT;
+found:
+	if (crp->cr_princhash.len) {
+		if (clp->cl_cred.cr_raw_principal)
+			principal = clp->cl_cred.cr_raw_principal;
+		else if (clp->cl_cred.cr_principal)
+			principal = clp->cl_cred.cr_principal;
+		if (principal == NULL)
+			return -ENOENT;
+		cksum.len = crypto_shash_digestsize(tfm);
+		cksum.data = kmalloc(cksum.len, GFP_KERNEL);
+		if (cksum.data == NULL)
+			return -ENOENT;
+		status = crypto_shash_tfm_digest(tfm, principal,
+						 strlen(principal), cksum.data);
+		if (status) {
+			kfree(cksum.data);
+			return -ENOENT;
+		}
+		if (memcmp(crp->cr_princhash.data, cksum.data,
+				crp->cr_princhash.len)) {
+			kfree(cksum.data);
+			return -ENOENT;
+		}
+		kfree(cksum.data);
+	}
+	crp->cr_clp = clp;
+	return 0;
+}
+
+static int
+nfsd4_cld_grace_start(struct nfsd_net *nn)
+{
+	int ret;
+	struct cld_upcall *cup;
+	struct cld_net *cn = nn->cld_net;
+
+	cup = alloc_cld_upcall(nn);
+	if (!cup) {
+		ret = -ENOMEM;
+		goto out_err;
+	}
+
+	cup->cu_u.cu_msg.cm_cmd = Cld_GraceStart;
+	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg, nn);
+	if (!ret)
+		ret = cup->cu_u.cu_msg.cm_status;
+
+	free_cld_upcall(cup);
+out_err:
+	if (ret)
+		dprintk("%s: Unable to get clients from userspace: %d\n",
+			__func__, ret);
+	return ret;
+}
+
+/* For older nfsdcld's that need cm_gracetime */
+static void
+nfsd4_cld_grace_done_v0(struct nfsd_net *nn)
+{
+	int ret;
+	struct cld_upcall *cup;
+	struct cld_net *cn = nn->cld_net;
+
+	cup = alloc_cld_upcall(nn);
+	if (!cup) {
+		ret = -ENOMEM;
+		goto out_err;
+	}
+
+	cup->cu_u.cu_msg.cm_cmd = Cld_GraceDone;
+	cup->cu_u.cu_msg.cm_u.cm_gracetime = nn->boot_time;
+	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg, nn);
+	if (!ret)
+		ret = cup->cu_u.cu_msg.cm_status;
+
+	free_cld_upcall(cup);
+out_err:
+	if (ret)
+		printk(KERN_ERR "NFSD: Unable to end grace period: %d\n", ret);
+}
+
+/*
+ * For newer nfsdcld's that do not need cm_gracetime.  We also need to call
+ * nfs4_release_reclaim() to clear out the reclaim_str_hashtbl.
+ */
+static void
+nfsd4_cld_grace_done(struct nfsd_net *nn)
+{
+	int ret;
+	struct cld_upcall *cup;
+	struct cld_net *cn = nn->cld_net;
+
+	cup = alloc_cld_upcall(nn);
+	if (!cup) {
+		ret = -ENOMEM;
+		goto out_err;
+	}
+
+	cup->cu_u.cu_msg.cm_cmd = Cld_GraceDone;
+	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg, nn);
+	if (!ret)
+		ret = cup->cu_u.cu_msg.cm_status;
+
+	free_cld_upcall(cup);
+out_err:
+	nfs4_release_reclaim(nn);
+	if (ret)
+		printk(KERN_ERR "NFSD: Unable to end grace period: %d\n", ret);
+}
+
+static int
+nfs4_cld_state_init(struct net *net)
+{
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+	int i;
+
+	nn->reclaim_str_hashtbl = kmalloc_array(CLIENT_HASH_SIZE,
+						sizeof(struct list_head),
+						GFP_KERNEL);
+	if (!nn->reclaim_str_hashtbl)
+		return -ENOMEM;
+
+	for (i = 0; i < CLIENT_HASH_SIZE; i++)
+		INIT_LIST_HEAD(&nn->reclaim_str_hashtbl[i]);
+	nn->reclaim_str_hashtbl_size = 0;
+	nn->track_reclaim_completes = true;
+	atomic_set(&nn->nr_reclaim_complete, 0);
+
+	return 0;
+}
+
+static void
+nfs4_cld_state_shutdown(struct net *net)
+{
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	nn->track_reclaim_completes = false;
+	kfree(nn->reclaim_str_hashtbl);
+}
+
+static bool
+cld_running(struct nfsd_net *nn)
+{
+	struct cld_net *cn = nn->cld_net;
+	struct rpc_pipe *pipe = cn->cn_pipe;
+
+	return pipe->nreaders || pipe->nwriters;
+}
+
+static int
+nfsd4_cld_get_version(struct nfsd_net *nn)
+{
+	int ret = 0;
+	struct cld_upcall *cup;
+	struct cld_net *cn = nn->cld_net;
+	uint8_t version;
+
+	cup = alloc_cld_upcall(nn);
+	if (!cup) {
+		ret = -ENOMEM;
+		goto out_err;
+	}
+	cup->cu_u.cu_msg.cm_cmd = Cld_GetVersion;
+	ret = cld_pipe_upcall(cn->cn_pipe, &cup->cu_u.cu_msg, nn);
+	if (!ret) {
+		ret = cup->cu_u.cu_msg.cm_status;
+		if (ret)
+			goto out_free;
+		version = cup->cu_u.cu_msg.cm_u.cm_version;
+		dprintk("%s: userspace returned version %u\n",
+				__func__, version);
+		if (version < 1)
+			version = 1;
+		else if (version > CLD_UPCALL_VERSION)
+			version = CLD_UPCALL_VERSION;
+
+		switch (version) {
+		case 1:
+			nn->client_tracking_ops = &nfsd4_cld_tracking_ops;
+			break;
+		case 2:
+			nn->client_tracking_ops = &nfsd4_cld_tracking_ops_v2;
+			break;
+		default:
+			break;
+		}
+	}
+out_free:
+	free_cld_upcall(cup);
+out_err:
+	if (ret)
+		dprintk("%s: Unable to get version from userspace: %d\n",
+			__func__, ret);
+	return ret;
+}
+
+static int
+nfsd4_cld_tracking_init(struct net *net)
+{
+	int status;
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+	bool running;
+	int retries = 10;
+	struct crypto_shash *tfm;
+
+	status = nfs4_cld_state_init(net);
+	if (status)
+		return status;
+
+	status = __nfsd4_init_cld_pipe(net);
+	if (status)
+		goto err_shutdown;
+
+	/*
+	 * rpc pipe upcalls take 30 seconds to time out, so we don't want to
+	 * queue an upcall unless we know that nfsdcld is running (because we
+	 * want this to fail fast so that nfsd4_client_tracking_init() can try
+	 * the next client tracking method).  nfsdcld should already be running
+	 * before nfsd is started, so the wait here is for nfsdcld to open the
+	 * pipefs file we just created.
+	 */
+	while (!(running = cld_running(nn)) && retries--)
+		msleep(100);
+
+	if (!running) {
+		status = -ETIMEDOUT;
+		goto err_remove;
+	}
+	tfm = crypto_alloc_shash("sha256", 0, 0);
+	if (IS_ERR(tfm)) {
+		status = PTR_ERR(tfm);
+		goto err_remove;
+	}
+	nn->cld_net->cn_tfm = tfm;
+
+	status = nfsd4_cld_get_version(nn);
+	if (status == -EOPNOTSUPP)
+		pr_warn("NFSD: nfsdcld GetVersion upcall failed. Please upgrade nfsdcld.\n");
+
+	status = nfsd4_cld_grace_start(nn);
+	if (status) {
+		if (status == -EOPNOTSUPP)
+			pr_warn("NFSD: nfsdcld GraceStart upcall failed. Please upgrade nfsdcld.\n");
+		nfs4_release_reclaim(nn);
+		goto err_remove;
+	} else
+		printk("NFSD: Using nfsdcld client tracking operations.\n");
+	return 0;
+
+err_remove:
+	nfsd4_remove_cld_pipe(net);
+err_shutdown:
+	nfs4_cld_state_shutdown(net);
+	return status;
+}
+
+static void
+nfsd4_cld_tracking_exit(struct net *net)
+{
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	nfs4_release_reclaim(nn);
+	nfsd4_remove_cld_pipe(net);
+	nfs4_cld_state_shutdown(net);
+}
+
+/* For older nfsdcld's */
+static const struct nfsd4_client_tracking_ops nfsd4_cld_tracking_ops_v0 = {
+	.init		= nfsd4_init_cld_pipe,
+	.exit		= nfsd4_remove_cld_pipe,
+	.create		= nfsd4_cld_create,
+	.remove		= nfsd4_cld_remove,
+	.check		= nfsd4_cld_check_v0,
+	.grace_done	= nfsd4_cld_grace_done_v0,
+	.version	= 1,
+	.msglen		= sizeof(struct cld_msg),
+};
+
+/* For newer nfsdcld's */
+static const struct nfsd4_client_tracking_ops nfsd4_cld_tracking_ops = {
+	.init		= nfsd4_cld_tracking_init,
+	.exit		= nfsd4_cld_tracking_exit,
+	.create		= nfsd4_cld_create,
+	.remove		= nfsd4_cld_remove,
+	.check		= nfsd4_cld_check,
+	.grace_done	= nfsd4_cld_grace_done,
+	.version	= 1,
+	.msglen		= sizeof(struct cld_msg),
+};
+
+/* v2 create/check ops include the principal, if available */
+static const struct nfsd4_client_tracking_ops nfsd4_cld_tracking_ops_v2 = {
+	.init		= nfsd4_cld_tracking_init,
+	.exit		= nfsd4_cld_tracking_exit,
+	.create		= nfsd4_cld_create_v2,
+	.remove		= nfsd4_cld_remove,
+	.check		= nfsd4_cld_check_v2,
+	.grace_done	= nfsd4_cld_grace_done,
+	.version	= 2,
+	.msglen		= sizeof(struct cld_msg_v2),
+};
+
+/* upcall via usermodehelper */
+static char cltrack_prog[PATH_MAX] = "/sbin/nfsdcltrack";
+module_param_string(cltrack_prog, cltrack_prog, sizeof(cltrack_prog),
+			S_IRUGO|S_IWUSR);
+MODULE_PARM_DESC(cltrack_prog, "Path to the nfsdcltrack upcall program");
+
+static bool cltrack_legacy_disable;
+module_param(cltrack_legacy_disable, bool, S_IRUGO|S_IWUSR);
+MODULE_PARM_DESC(cltrack_legacy_disable,
+		"Disable legacy recoverydir conversion. Default: false");
+
+#define LEGACY_TOPDIR_ENV_PREFIX "NFSDCLTRACK_LEGACY_TOPDIR="
+#define LEGACY_RECDIR_ENV_PREFIX "NFSDCLTRACK_LEGACY_RECDIR="
+#define HAS_SESSION_ENV_PREFIX "NFSDCLTRACK_CLIENT_HAS_SESSION="
+#define GRACE_START_ENV_PREFIX "NFSDCLTRACK_GRACE_START="
+
+static char *
+nfsd4_cltrack_legacy_topdir(void)
+{
+	int copied;
+	size_t len;
+	char *result;
+
+	if (cltrack_legacy_disable)
+		return NULL;
+
+	len = strlen(LEGACY_TOPDIR_ENV_PREFIX) +
+		strlen(nfs4_recoverydir()) + 1;
+
+	result = kmalloc(len, GFP_KERNEL);
+	if (!result)
+		return result;
+
+	copied = snprintf(result, len, LEGACY_TOPDIR_ENV_PREFIX "%s",
+				nfs4_recoverydir());
+	if (copied >= len) {
+		/* just return nothing if output was truncated */
+		kfree(result);
+		return NULL;
+	}
+
+	return result;
+}
+
+static char *
+nfsd4_cltrack_legacy_recdir(const struct xdr_netobj *name)
+{
+	int copied;
+	size_t len;
+	char *result;
+
+	if (cltrack_legacy_disable)
+		return NULL;
+
+	/* +1 is for '/' between "topdir" and "recdir" */
+	len = strlen(LEGACY_RECDIR_ENV_PREFIX) +
+		strlen(nfs4_recoverydir()) + 1 + HEXDIR_LEN;
+
+	result = kmalloc(len, GFP_KERNEL);
+	if (!result)
+		return result;
+
+	copied = snprintf(result, len, LEGACY_RECDIR_ENV_PREFIX "%s/",
+				nfs4_recoverydir());
+	if (copied > (len - HEXDIR_LEN)) {
+		/* just return nothing if output will be truncated */
+		kfree(result);
+		return NULL;
+	}
+
+	copied = nfs4_make_rec_clidname(result + copied, name);
+	if (copied) {
+		kfree(result);
+		return NULL;
+	}
+
+	return result;
+}
+
+static char *
+nfsd4_cltrack_client_has_session(struct nfs4_client *clp)
+{
+	int copied;
+	size_t len;
+	char *result;
+
+	/* prefix + Y/N character + terminating NULL */
+	len = strlen(HAS_SESSION_ENV_PREFIX) + 1 + 1;
+
+	result = kmalloc(len, GFP_KERNEL);
+	if (!result)
+		return result;
+
+	copied = snprintf(result, len, HAS_SESSION_ENV_PREFIX "%c",
+				clp->cl_minorversion ? 'Y' : 'N');
+	if (copied >= len) {
+		/* just return nothing if output was truncated */
+		kfree(result);
+		return NULL;
+	}
+
+	return result;
+}
+
+static char *
+nfsd4_cltrack_grace_start(time64_t grace_start)
+{
+	int copied;
+	size_t len;
+	char *result;
+
+	/* prefix + max width of int64_t string + terminating NULL */
+	len = strlen(GRACE_START_ENV_PREFIX) + 22 + 1;
+
+	result = kmalloc(len, GFP_KERNEL);
+	if (!result)
+		return result;
+
+	copied = snprintf(result, len, GRACE_START_ENV_PREFIX "%lld",
+				grace_start);
+	if (copied >= len) {
+		/* just return nothing if output was truncated */
+		kfree(result);
+		return NULL;
+	}
+
+	return result;
+}
+
+static int
+nfsd4_umh_cltrack_upcall(char *cmd, char *arg, char *env0, char *env1)
+{
+	char *envp[3];
+	char *argv[4];
+	int ret;
+
+	if (unlikely(!cltrack_prog[0])) {
+		dprintk("%s: cltrack_prog is disabled\n", __func__);
+		return -EACCES;
+	}
+
+	dprintk("%s: cmd: %s\n", __func__, cmd);
+	dprintk("%s: arg: %s\n", __func__, arg ? arg : "(null)");
+	dprintk("%s: env0: %s\n", __func__, env0 ? env0 : "(null)");
+	dprintk("%s: env1: %s\n", __func__, env1 ? env1 : "(null)");
+
+	envp[0] = env0;
+	envp[1] = env1;
+	envp[2] = NULL;
+
+	argv[0] = (char *)cltrack_prog;
+	argv[1] = cmd;
+	argv[2] = arg;
+	argv[3] = NULL;
+
+	ret = call_usermodehelper(argv[0], argv, envp, UMH_WAIT_PROC);
+	/*
+	 * Disable the upcall mechanism if we're getting an ENOENT or EACCES
+	 * error. The admin can re-enable it on the fly by using sysfs
+	 * once the problem has been fixed.
+	 */
+	if (ret == -ENOENT || ret == -EACCES) {
+		dprintk("NFSD: %s was not found or isn't executable (%d). "
+			"Setting cltrack_prog to blank string!",
+			cltrack_prog, ret);
+		cltrack_prog[0] = '\0';
+	}
+	dprintk("%s: %s return value: %d\n", __func__, cltrack_prog, ret);
+
+	return ret;
+}
+
+static char *
+bin_to_hex_dup(const unsigned char *src, int srclen)
+{
+	char *buf;
+
+	/* +1 for terminating NULL */
+	buf = kzalloc((srclen * 2) + 1, GFP_KERNEL);
+	if (!buf)
+		return buf;
+
+	bin2hex(buf, src, srclen);
+	return buf;
+}
+
+static int
+nfsd4_umh_cltrack_init(struct net *net)
+{
+	int ret;
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+	char *grace_start = nfsd4_cltrack_grace_start(nn->boot_time);
+
+	/* XXX: The usermode helper s not working in container yet. */
+	if (net != &init_net) {
+		pr_warn("NFSD: attempt to initialize umh client tracking in a container ignored.\n");
+		kfree(grace_start);
+		return -EINVAL;
+	}
+
+	ret = nfsd4_umh_cltrack_upcall("init", NULL, grace_start, NULL);
+	kfree(grace_start);
+	if (!ret)
+		printk("NFSD: Using UMH upcall client tracking operations.\n");
+	return ret;
+}
+
+static void
+nfsd4_cltrack_upcall_lock(struct nfs4_client *clp)
+{
+	wait_on_bit_lock(&clp->cl_flags, NFSD4_CLIENT_UPCALL_LOCK,
+			 TASK_UNINTERRUPTIBLE);
+}
+
+static void
+nfsd4_cltrack_upcall_unlock(struct nfs4_client *clp)
+{
+	smp_mb__before_atomic();
+	clear_bit(NFSD4_CLIENT_UPCALL_LOCK, &clp->cl_flags);
+	smp_mb__after_atomic();
+	wake_up_bit(&clp->cl_flags, NFSD4_CLIENT_UPCALL_LOCK);
+}
+
+static void
+nfsd4_umh_cltrack_create(struct nfs4_client *clp)
+{
+	char *hexid, *has_session, *grace_start;
+	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+
+	/*
+	 * With v4.0 clients, there's little difference in outcome between a
+	 * create and check operation, and we can end up calling into this
+	 * function multiple times per client (once for each openowner). So,
+	 * for v4.0 clients skip upcalling once the client has been recorded
+	 * on stable storage.
+	 *
+	 * For v4.1+ clients, the outcome of the two operations is different,
+	 * so we must ensure that we upcall for the create operation. v4.1+
+	 * clients call this on RECLAIM_COMPLETE though, so we should only end
+	 * up doing a single create upcall per client.
+	 */
+	if (clp->cl_minorversion == 0 &&
+	    test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
+		return;
+
+	hexid = bin_to_hex_dup(clp->cl_name.data, clp->cl_name.len);
+	if (!hexid) {
+		dprintk("%s: can't allocate memory for upcall!\n", __func__);
+		return;
+	}
+
+	has_session = nfsd4_cltrack_client_has_session(clp);
+	grace_start = nfsd4_cltrack_grace_start(nn->boot_time);
+
+	nfsd4_cltrack_upcall_lock(clp);
+	if (!nfsd4_umh_cltrack_upcall("create", hexid, has_session, grace_start))
+		set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
+	nfsd4_cltrack_upcall_unlock(clp);
+
+	kfree(has_session);
+	kfree(grace_start);
+	kfree(hexid);
+}
+
+static void
+nfsd4_umh_cltrack_remove(struct nfs4_client *clp)
+{
+	char *hexid;
+
+	if (!test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
+		return;
+
+	hexid = bin_to_hex_dup(clp->cl_name.data, clp->cl_name.len);
+	if (!hexid) {
+		dprintk("%s: can't allocate memory for upcall!\n", __func__);
+		return;
+	}
+
+	nfsd4_cltrack_upcall_lock(clp);
+	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags) &&
+	    nfsd4_umh_cltrack_upcall("remove", hexid, NULL, NULL) == 0)
+		clear_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
+	nfsd4_cltrack_upcall_unlock(clp);
+
+	kfree(hexid);
+}
+
+static int
+nfsd4_umh_cltrack_check(struct nfs4_client *clp)
+{
+	int ret;
+	char *hexid, *has_session, *legacy;
+
+	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags))
+		return 0;
+
+	hexid = bin_to_hex_dup(clp->cl_name.data, clp->cl_name.len);
+	if (!hexid) {
+		dprintk("%s: can't allocate memory for upcall!\n", __func__);
+		return -ENOMEM;
+	}
+
+	has_session = nfsd4_cltrack_client_has_session(clp);
+	legacy = nfsd4_cltrack_legacy_recdir(&clp->cl_name);
+
+	nfsd4_cltrack_upcall_lock(clp);
+	if (test_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags)) {
+		ret = 0;
+	} else {
+		ret = nfsd4_umh_cltrack_upcall("check", hexid, has_session, legacy);
+		if (ret == 0)
+			set_bit(NFSD4_CLIENT_STABLE, &clp->cl_flags);
+	}
+	nfsd4_cltrack_upcall_unlock(clp);
+	kfree(has_session);
+	kfree(legacy);
+	kfree(hexid);
+
+	return ret;
+}
+
+static void
+nfsd4_umh_cltrack_grace_done(struct nfsd_net *nn)
+{
+	char *legacy;
+	char timestr[22]; /* FIXME: better way to determine max size? */
+
+	sprintf(timestr, "%lld", nn->boot_time);
+	legacy = nfsd4_cltrack_legacy_topdir();
+	nfsd4_umh_cltrack_upcall("gracedone", timestr, legacy, NULL);
+	kfree(legacy);
+}
+
+static const struct nfsd4_client_tracking_ops nfsd4_umh_tracking_ops = {
+	.init		= nfsd4_umh_cltrack_init,
+	.exit		= NULL,
+	.create		= nfsd4_umh_cltrack_create,
+	.remove		= nfsd4_umh_cltrack_remove,
+	.check		= nfsd4_umh_cltrack_check,
+	.grace_done	= nfsd4_umh_cltrack_grace_done,
+	.version	= 1,
+	.msglen		= 0,
+};
+
+int
+nfsd4_client_tracking_init(struct net *net)
+{
+	int status;
+	struct path path;
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	/* just run the init if it the method is already decided */
+	if (nn->client_tracking_ops)
+		goto do_init;
+
+	/* First, try to use nfsdcld */
+	nn->client_tracking_ops = &nfsd4_cld_tracking_ops;
+	status = nn->client_tracking_ops->init(net);
+	if (!status)
+		return status;
+	if (status != -ETIMEDOUT) {
+		nn->client_tracking_ops = &nfsd4_cld_tracking_ops_v0;
+		status = nn->client_tracking_ops->init(net);
+		if (!status)
+			return status;
+	}
+
+	/*
+	 * Next, try the UMH upcall.
+	 */
+	nn->client_tracking_ops = &nfsd4_umh_tracking_ops;
+	status = nn->client_tracking_ops->init(net);
+	if (!status)
+		return status;
+
+	/*
+	 * Finally, See if the recoverydir exists and is a directory.
+	 * If it is, then use the legacy ops.
+	 */
+	nn->client_tracking_ops = &nfsd4_legacy_tracking_ops;
+	status = kern_path(nfs4_recoverydir(), LOOKUP_FOLLOW, &path);
+	if (!status) {
+		status = d_is_dir(path.dentry);
+		path_put(&path);
+		if (!status) {
+			status = -EINVAL;
+			goto out;
+		}
+	}
+
+do_init:
+	status = nn->client_tracking_ops->init(net);
+out:
+	if (status) {
+		printk(KERN_WARNING "NFSD: Unable to initialize client "
+				    "recovery tracking! (%d)\n", status);
+		nn->client_tracking_ops = NULL;
+	}
+	return status;
+}
+
+void
+nfsd4_client_tracking_exit(struct net *net)
+{
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	if (nn->client_tracking_ops) {
+		if (nn->client_tracking_ops->exit)
+			nn->client_tracking_ops->exit(net);
+		nn->client_tracking_ops = NULL;
+	}
+}
+
+void
+nfsd4_client_record_create(struct nfs4_client *clp)
+{
+	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+
+	if (nn->client_tracking_ops)
+		nn->client_tracking_ops->create(clp);
+}
+
+void
+nfsd4_client_record_remove(struct nfs4_client *clp)
+{
+	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+
+	if (nn->client_tracking_ops)
+		nn->client_tracking_ops->remove(clp);
+}
+
+int
+nfsd4_client_record_check(struct nfs4_client *clp)
+{
+	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+
+	if (nn->client_tracking_ops)
+		return nn->client_tracking_ops->check(clp);
+
+	return -EOPNOTSUPP;
+}
+
+void
+nfsd4_record_grace_done(struct nfsd_net *nn)
+{
+	if (nn->client_tracking_ops)
+		nn->client_tracking_ops->grace_done(nn);
+}
+
+static int
+rpc_pipefs_event(struct notifier_block *nb, unsigned long event, void *ptr)
+{
+	struct super_block *sb = ptr;
+	struct net *net = sb->s_fs_info;
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+	struct cld_net *cn = nn->cld_net;
+	struct dentry *dentry;
+	int ret = 0;
+
+	if (!try_module_get(THIS_MODULE))
+		return 0;
+
+	if (!cn) {
+		module_put(THIS_MODULE);
+		return 0;
+	}
+
+	switch (event) {
+	case RPC_PIPEFS_MOUNT:
+		dentry = nfsd4_cld_register_sb(sb, cn->cn_pipe);
+		if (IS_ERR(dentry)) {
+			ret = PTR_ERR(dentry);
+			break;
+		}
+		cn->cn_pipe->dentry = dentry;
+		break;
+	case RPC_PIPEFS_UMOUNT:
+		if (cn->cn_pipe->dentry)
+			nfsd4_cld_unregister_sb(cn->cn_pipe);
+		break;
+	default:
+		ret = -ENOTSUPP;
+		break;
+	}
+	module_put(THIS_MODULE);
+	return ret;
+}
+
+static struct notifier_block nfsd4_cld_block = {
+	.notifier_call = rpc_pipefs_event,
+};
+
+int
+register_cld_notifier(void)
+{
+	WARN_ON(!nfsd_net_id);
+	return rpc_pipefs_notifier_register(&nfsd4_cld_block);
+}
+
+void
+unregister_cld_notifier(void)
+{
+	rpc_pipefs_notifier_unregister(&nfsd4_cld_block);
+}
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
new file mode 100644
index 000000000..d402ca0b5
--- /dev/null
+++ b/fs/nfsd/nfs4state.c
@@ -0,0 +1,7588 @@
+/*
+*  Copyright (c) 2001 The Regents of the University of Michigan.
+*  All rights reserved.
+*
+*  Kendrick Smith <kmsmith@umich.edu>
+*  Andy Adamson <kandros@umich.edu>
+*
+*  Redistribution and use in source and binary forms, with or without
+*  modification, are permitted provided that the following conditions
+*  are met:
+*
+*  1. Redistributions of source code must retain the above copyright
+*     notice, this list of conditions and the following disclaimer.
+*  2. Redistributions in binary form must reproduce the above copyright
+*     notice, this list of conditions and the following disclaimer in the
+*     documentation and/or other materials provided with the distribution.
+*  3. Neither the name of the University nor the names of its
+*     contributors may be used to endorse or promote products derived
+*     from this software without specific prior written permission.
+*
+*  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
+*  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+*  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+*  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+*  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+*  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+*  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+*  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+*  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+*  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+*  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*
+*/
+
+#include <linux/file.h>
+#include <linux/fs.h>
+#include <linux/slab.h>
+#include <linux/namei.h>
+#include <linux/swap.h>
+#include <linux/pagemap.h>
+#include <linux/ratelimit.h>
+#include <linux/sunrpc/svcauth_gss.h>
+#include <linux/sunrpc/addr.h>
+#include <linux/jhash.h>
+#include <linux/string_helpers.h>
+#include "xdr4.h"
+#include "xdr4cb.h"
+#include "vfs.h"
+#include "current_stateid.h"
+
+#include "netns.h"
+#include "pnfs.h"
+#include "filecache.h"
+#include "trace.h"
+
+#define NFSDDBG_FACILITY                NFSDDBG_PROC
+
+#define all_ones {{~0,~0},~0}
+static const stateid_t one_stateid = {
+	.si_generation = ~0,
+	.si_opaque = all_ones,
+};
+static const stateid_t zero_stateid = {
+	/* all fields zero */
+};
+static const stateid_t currentstateid = {
+	.si_generation = 1,
+};
+static const stateid_t close_stateid = {
+	.si_generation = 0xffffffffU,
+};
+
+static u64 current_sessionid = 1;
+
+#define ZERO_STATEID(stateid) (!memcmp((stateid), &zero_stateid, sizeof(stateid_t)))
+#define ONE_STATEID(stateid)  (!memcmp((stateid), &one_stateid, sizeof(stateid_t)))
+#define CURRENT_STATEID(stateid) (!memcmp((stateid), &currentstateid, sizeof(stateid_t)))
+#define CLOSE_STATEID(stateid)  (!memcmp((stateid), &close_stateid, sizeof(stateid_t)))
+
+/* forward declarations */
+static bool check_for_locks(struct nfs4_file *fp, struct nfs4_lockowner *lowner);
+static void nfs4_free_ol_stateid(struct nfs4_stid *stid);
+void nfsd4_end_grace(struct nfsd_net *nn);
+static void _free_cpntf_state_locked(struct nfsd_net *nn, struct nfs4_cpntf_state *cps);
+
+/* Locking: */
+
+/*
+ * Currently used for the del_recall_lru and file hash table.  In an
+ * effort to decrease the scope of the client_mutex, this spinlock may
+ * eventually cover more:
+ */
+static DEFINE_SPINLOCK(state_lock);
+
+enum nfsd4_st_mutex_lock_subclass {
+	OPEN_STATEID_MUTEX = 0,
+	LOCK_STATEID_MUTEX = 1,
+};
+
+/*
+ * A waitqueue for all in-progress 4.0 CLOSE operations that are waiting for
+ * the refcount on the open stateid to drop.
+ */
+static DECLARE_WAIT_QUEUE_HEAD(close_wq);
+
+/*
+ * A waitqueue where a writer to clients/#/ctl destroying a client can
+ * wait for cl_rpc_users to drop to 0 and then for the client to be
+ * unhashed.
+ */
+static DECLARE_WAIT_QUEUE_HEAD(expiry_wq);
+
+static struct kmem_cache *client_slab;
+static struct kmem_cache *openowner_slab;
+static struct kmem_cache *lockowner_slab;
+static struct kmem_cache *file_slab;
+static struct kmem_cache *stateid_slab;
+static struct kmem_cache *deleg_slab;
+static struct kmem_cache *odstate_slab;
+
+static void free_session(struct nfsd4_session *);
+
+static const struct nfsd4_callback_ops nfsd4_cb_recall_ops;
+static const struct nfsd4_callback_ops nfsd4_cb_notify_lock_ops;
+
+static bool is_session_dead(struct nfsd4_session *ses)
+{
+	return ses->se_flags & NFS4_SESSION_DEAD;
+}
+
+static __be32 mark_session_dead_locked(struct nfsd4_session *ses, int ref_held_by_me)
+{
+	if (atomic_read(&ses->se_ref) > ref_held_by_me)
+		return nfserr_jukebox;
+	ses->se_flags |= NFS4_SESSION_DEAD;
+	return nfs_ok;
+}
+
+static bool is_client_expired(struct nfs4_client *clp)
+{
+	return clp->cl_time == 0;
+}
+
+static __be32 get_client_locked(struct nfs4_client *clp)
+{
+	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+
+	lockdep_assert_held(&nn->client_lock);
+
+	if (is_client_expired(clp))
+		return nfserr_expired;
+	atomic_inc(&clp->cl_rpc_users);
+	return nfs_ok;
+}
+
+/* must be called under the client_lock */
+static inline void
+renew_client_locked(struct nfs4_client *clp)
+{
+	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+
+	if (is_client_expired(clp)) {
+		WARN_ON(1);
+		printk("%s: client (clientid %08x/%08x) already expired\n",
+			__func__,
+			clp->cl_clientid.cl_boot,
+			clp->cl_clientid.cl_id);
+		return;
+	}
+
+	list_move_tail(&clp->cl_lru, &nn->client_lru);
+	clp->cl_time = ktime_get_boottime_seconds();
+}
+
+static void put_client_renew_locked(struct nfs4_client *clp)
+{
+	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+
+	lockdep_assert_held(&nn->client_lock);
+
+	if (!atomic_dec_and_test(&clp->cl_rpc_users))
+		return;
+	if (!is_client_expired(clp))
+		renew_client_locked(clp);
+	else
+		wake_up_all(&expiry_wq);
+}
+
+static void put_client_renew(struct nfs4_client *clp)
+{
+	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+
+	if (!atomic_dec_and_lock(&clp->cl_rpc_users, &nn->client_lock))
+		return;
+	if (!is_client_expired(clp))
+		renew_client_locked(clp);
+	else
+		wake_up_all(&expiry_wq);
+	spin_unlock(&nn->client_lock);
+}
+
+static __be32 nfsd4_get_session_locked(struct nfsd4_session *ses)
+{
+	__be32 status;
+
+	if (is_session_dead(ses))
+		return nfserr_badsession;
+	status = get_client_locked(ses->se_client);
+	if (status)
+		return status;
+	atomic_inc(&ses->se_ref);
+	return nfs_ok;
+}
+
+static void nfsd4_put_session_locked(struct nfsd4_session *ses)
+{
+	struct nfs4_client *clp = ses->se_client;
+	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+
+	lockdep_assert_held(&nn->client_lock);
+
+	if (atomic_dec_and_test(&ses->se_ref) && is_session_dead(ses))
+		free_session(ses);
+	put_client_renew_locked(clp);
+}
+
+static void nfsd4_put_session(struct nfsd4_session *ses)
+{
+	struct nfs4_client *clp = ses->se_client;
+	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+
+	spin_lock(&nn->client_lock);
+	nfsd4_put_session_locked(ses);
+	spin_unlock(&nn->client_lock);
+}
+
+static struct nfsd4_blocked_lock *
+find_blocked_lock(struct nfs4_lockowner *lo, struct knfsd_fh *fh,
+			struct nfsd_net *nn)
+{
+	struct nfsd4_blocked_lock *cur, *found = NULL;
+
+	spin_lock(&nn->blocked_locks_lock);
+	list_for_each_entry(cur, &lo->lo_blocked, nbl_list) {
+		if (fh_match(fh, &cur->nbl_fh)) {
+			list_del_init(&cur->nbl_list);
+			list_del_init(&cur->nbl_lru);
+			found = cur;
+			break;
+		}
+	}
+	spin_unlock(&nn->blocked_locks_lock);
+	if (found)
+		locks_delete_block(&found->nbl_lock);
+	return found;
+}
+
+static struct nfsd4_blocked_lock *
+find_or_allocate_block(struct nfs4_lockowner *lo, struct knfsd_fh *fh,
+			struct nfsd_net *nn)
+{
+	struct nfsd4_blocked_lock *nbl;
+
+	nbl = find_blocked_lock(lo, fh, nn);
+	if (!nbl) {
+		nbl= kmalloc(sizeof(*nbl), GFP_KERNEL);
+		if (nbl) {
+			INIT_LIST_HEAD(&nbl->nbl_list);
+			INIT_LIST_HEAD(&nbl->nbl_lru);
+			fh_copy_shallow(&nbl->nbl_fh, fh);
+			locks_init_lock(&nbl->nbl_lock);
+			nfsd4_init_cb(&nbl->nbl_cb, lo->lo_owner.so_client,
+					&nfsd4_cb_notify_lock_ops,
+					NFSPROC4_CLNT_CB_NOTIFY_LOCK);
+		}
+	}
+	return nbl;
+}
+
+static void
+free_blocked_lock(struct nfsd4_blocked_lock *nbl)
+{
+	locks_delete_block(&nbl->nbl_lock);
+	locks_release_private(&nbl->nbl_lock);
+	kfree(nbl);
+}
+
+static void
+remove_blocked_locks(struct nfs4_lockowner *lo)
+{
+	struct nfs4_client *clp = lo->lo_owner.so_client;
+	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+	struct nfsd4_blocked_lock *nbl;
+	LIST_HEAD(reaplist);
+
+	/* Dequeue all blocked locks */
+	spin_lock(&nn->blocked_locks_lock);
+	while (!list_empty(&lo->lo_blocked)) {
+		nbl = list_first_entry(&lo->lo_blocked,
+					struct nfsd4_blocked_lock,
+					nbl_list);
+		list_del_init(&nbl->nbl_list);
+		list_move(&nbl->nbl_lru, &reaplist);
+	}
+	spin_unlock(&nn->blocked_locks_lock);
+
+	/* Now free them */
+	while (!list_empty(&reaplist)) {
+		nbl = list_first_entry(&reaplist, struct nfsd4_blocked_lock,
+					nbl_lru);
+		list_del_init(&nbl->nbl_lru);
+		free_blocked_lock(nbl);
+	}
+}
+
+static void
+nfsd4_cb_notify_lock_prepare(struct nfsd4_callback *cb)
+{
+	struct nfsd4_blocked_lock	*nbl = container_of(cb,
+						struct nfsd4_blocked_lock, nbl_cb);
+	locks_delete_block(&nbl->nbl_lock);
+}
+
+static int
+nfsd4_cb_notify_lock_done(struct nfsd4_callback *cb, struct rpc_task *task)
+{
+	/*
+	 * Since this is just an optimization, we don't try very hard if it
+	 * turns out not to succeed. We'll requeue it on NFS4ERR_DELAY, and
+	 * just quit trying on anything else.
+	 */
+	switch (task->tk_status) {
+	case -NFS4ERR_DELAY:
+		rpc_delay(task, 1 * HZ);
+		return 0;
+	default:
+		return 1;
+	}
+}
+
+static void
+nfsd4_cb_notify_lock_release(struct nfsd4_callback *cb)
+{
+	struct nfsd4_blocked_lock	*nbl = container_of(cb,
+						struct nfsd4_blocked_lock, nbl_cb);
+
+	free_blocked_lock(nbl);
+}
+
+static const struct nfsd4_callback_ops nfsd4_cb_notify_lock_ops = {
+	.prepare	= nfsd4_cb_notify_lock_prepare,
+	.done		= nfsd4_cb_notify_lock_done,
+	.release	= nfsd4_cb_notify_lock_release,
+};
+
+static inline struct nfs4_stateowner *
+nfs4_get_stateowner(struct nfs4_stateowner *sop)
+{
+	atomic_inc(&sop->so_count);
+	return sop;
+}
+
+static int
+same_owner_str(struct nfs4_stateowner *sop, struct xdr_netobj *owner)
+{
+	return (sop->so_owner.len == owner->len) &&
+		0 == memcmp(sop->so_owner.data, owner->data, owner->len);
+}
+
+static struct nfs4_openowner *
+find_openstateowner_str_locked(unsigned int hashval, struct nfsd4_open *open,
+			struct nfs4_client *clp)
+{
+	struct nfs4_stateowner *so;
+
+	lockdep_assert_held(&clp->cl_lock);
+
+	list_for_each_entry(so, &clp->cl_ownerstr_hashtbl[hashval],
+			    so_strhash) {
+		if (!so->so_is_open_owner)
+			continue;
+		if (same_owner_str(so, &open->op_owner))
+			return openowner(nfs4_get_stateowner(so));
+	}
+	return NULL;
+}
+
+static struct nfs4_openowner *
+find_openstateowner_str(unsigned int hashval, struct nfsd4_open *open,
+			struct nfs4_client *clp)
+{
+	struct nfs4_openowner *oo;
+
+	spin_lock(&clp->cl_lock);
+	oo = find_openstateowner_str_locked(hashval, open, clp);
+	spin_unlock(&clp->cl_lock);
+	return oo;
+}
+
+static inline u32
+opaque_hashval(const void *ptr, int nbytes)
+{
+	unsigned char *cptr = (unsigned char *) ptr;
+
+	u32 x = 0;
+	while (nbytes--) {
+		x *= 37;
+		x += *cptr++;
+	}
+	return x;
+}
+
+static void nfsd4_free_file_rcu(struct rcu_head *rcu)
+{
+	struct nfs4_file *fp = container_of(rcu, struct nfs4_file, fi_rcu);
+
+	kmem_cache_free(file_slab, fp);
+}
+
+void
+put_nfs4_file(struct nfs4_file *fi)
+{
+	might_lock(&state_lock);
+
+	if (refcount_dec_and_lock(&fi->fi_ref, &state_lock)) {
+		hlist_del_rcu(&fi->fi_hash);
+		spin_unlock(&state_lock);
+		WARN_ON_ONCE(!list_empty(&fi->fi_clnt_odstate));
+		WARN_ON_ONCE(!list_empty(&fi->fi_delegations));
+		call_rcu(&fi->fi_rcu, nfsd4_free_file_rcu);
+	}
+}
+
+static struct nfsd_file *
+__nfs4_get_fd(struct nfs4_file *f, int oflag)
+{
+	if (f->fi_fds[oflag])
+		return nfsd_file_get(f->fi_fds[oflag]);
+	return NULL;
+}
+
+static struct nfsd_file *
+find_writeable_file_locked(struct nfs4_file *f)
+{
+	struct nfsd_file *ret;
+
+	lockdep_assert_held(&f->fi_lock);
+
+	ret = __nfs4_get_fd(f, O_WRONLY);
+	if (!ret)
+		ret = __nfs4_get_fd(f, O_RDWR);
+	return ret;
+}
+
+static struct nfsd_file *
+find_writeable_file(struct nfs4_file *f)
+{
+	struct nfsd_file *ret;
+
+	spin_lock(&f->fi_lock);
+	ret = find_writeable_file_locked(f);
+	spin_unlock(&f->fi_lock);
+
+	return ret;
+}
+
+static struct nfsd_file *
+find_readable_file_locked(struct nfs4_file *f)
+{
+	struct nfsd_file *ret;
+
+	lockdep_assert_held(&f->fi_lock);
+
+	ret = __nfs4_get_fd(f, O_RDONLY);
+	if (!ret)
+		ret = __nfs4_get_fd(f, O_RDWR);
+	return ret;
+}
+
+static struct nfsd_file *
+find_readable_file(struct nfs4_file *f)
+{
+	struct nfsd_file *ret;
+
+	spin_lock(&f->fi_lock);
+	ret = find_readable_file_locked(f);
+	spin_unlock(&f->fi_lock);
+
+	return ret;
+}
+
+struct nfsd_file *
+find_any_file(struct nfs4_file *f)
+{
+	struct nfsd_file *ret;
+
+	if (!f)
+		return NULL;
+	spin_lock(&f->fi_lock);
+	ret = __nfs4_get_fd(f, O_RDWR);
+	if (!ret) {
+		ret = __nfs4_get_fd(f, O_WRONLY);
+		if (!ret)
+			ret = __nfs4_get_fd(f, O_RDONLY);
+	}
+	spin_unlock(&f->fi_lock);
+	return ret;
+}
+
+static struct nfsd_file *find_any_file_locked(struct nfs4_file *f)
+{
+	lockdep_assert_held(&f->fi_lock);
+
+	if (f->fi_fds[O_RDWR])
+		return f->fi_fds[O_RDWR];
+	if (f->fi_fds[O_WRONLY])
+		return f->fi_fds[O_WRONLY];
+	if (f->fi_fds[O_RDONLY])
+		return f->fi_fds[O_RDONLY];
+	return NULL;
+}
+
+static struct nfsd_file *find_deleg_file_locked(struct nfs4_file *f)
+{
+	lockdep_assert_held(&f->fi_lock);
+
+	if (f->fi_deleg_file)
+		return f->fi_deleg_file;
+	return NULL;
+}
+
+static atomic_long_t num_delegations;
+unsigned long max_delegations;
+
+/*
+ * Open owner state (share locks)
+ */
+
+/* hash tables for lock and open owners */
+#define OWNER_HASH_BITS              8
+#define OWNER_HASH_SIZE             (1 << OWNER_HASH_BITS)
+#define OWNER_HASH_MASK             (OWNER_HASH_SIZE - 1)
+
+static unsigned int ownerstr_hashval(struct xdr_netobj *ownername)
+{
+	unsigned int ret;
+
+	ret = opaque_hashval(ownername->data, ownername->len);
+	return ret & OWNER_HASH_MASK;
+}
+
+/* hash table for nfs4_file */
+#define FILE_HASH_BITS                   8
+#define FILE_HASH_SIZE                  (1 << FILE_HASH_BITS)
+
+static unsigned int nfsd_fh_hashval(struct knfsd_fh *fh)
+{
+	return jhash2(fh->fh_base.fh_pad, XDR_QUADLEN(fh->fh_size), 0);
+}
+
+static unsigned int file_hashval(struct knfsd_fh *fh)
+{
+	return nfsd_fh_hashval(fh) & (FILE_HASH_SIZE - 1);
+}
+
+static struct hlist_head file_hashtbl[FILE_HASH_SIZE];
+
+static void
+__nfs4_file_get_access(struct nfs4_file *fp, u32 access)
+{
+	lockdep_assert_held(&fp->fi_lock);
+
+	if (access & NFS4_SHARE_ACCESS_WRITE)
+		atomic_inc(&fp->fi_access[O_WRONLY]);
+	if (access & NFS4_SHARE_ACCESS_READ)
+		atomic_inc(&fp->fi_access[O_RDONLY]);
+}
+
+static __be32
+nfs4_file_get_access(struct nfs4_file *fp, u32 access)
+{
+	lockdep_assert_held(&fp->fi_lock);
+
+	/* Does this access mode make sense? */
+	if (access & ~NFS4_SHARE_ACCESS_BOTH)
+		return nfserr_inval;
+
+	/* Does it conflict with a deny mode already set? */
+	if ((access & fp->fi_share_deny) != 0)
+		return nfserr_share_denied;
+
+	__nfs4_file_get_access(fp, access);
+	return nfs_ok;
+}
+
+static __be32 nfs4_file_check_deny(struct nfs4_file *fp, u32 deny)
+{
+	/* Common case is that there is no deny mode. */
+	if (deny) {
+		/* Does this deny mode make sense? */
+		if (deny & ~NFS4_SHARE_DENY_BOTH)
+			return nfserr_inval;
+
+		if ((deny & NFS4_SHARE_DENY_READ) &&
+		    atomic_read(&fp->fi_access[O_RDONLY]))
+			return nfserr_share_denied;
+
+		if ((deny & NFS4_SHARE_DENY_WRITE) &&
+		    atomic_read(&fp->fi_access[O_WRONLY]))
+			return nfserr_share_denied;
+	}
+	return nfs_ok;
+}
+
+static void __nfs4_file_put_access(struct nfs4_file *fp, int oflag)
+{
+	might_lock(&fp->fi_lock);
+
+	if (atomic_dec_and_lock(&fp->fi_access[oflag], &fp->fi_lock)) {
+		struct nfsd_file *f1 = NULL;
+		struct nfsd_file *f2 = NULL;
+
+		swap(f1, fp->fi_fds[oflag]);
+		if (atomic_read(&fp->fi_access[1 - oflag]) == 0)
+			swap(f2, fp->fi_fds[O_RDWR]);
+		spin_unlock(&fp->fi_lock);
+		if (f1)
+			nfsd_file_put(f1);
+		if (f2)
+			nfsd_file_put(f2);
+	}
+}
+
+static void nfs4_file_put_access(struct nfs4_file *fp, u32 access)
+{
+	WARN_ON_ONCE(access & ~NFS4_SHARE_ACCESS_BOTH);
+
+	if (access & NFS4_SHARE_ACCESS_WRITE)
+		__nfs4_file_put_access(fp, O_WRONLY);
+	if (access & NFS4_SHARE_ACCESS_READ)
+		__nfs4_file_put_access(fp, O_RDONLY);
+}
+
+/*
+ * Allocate a new open/delegation state counter. This is needed for
+ * pNFS for proper return on close semantics.
+ *
+ * Note that we only allocate it for pNFS-enabled exports, otherwise
+ * all pointers to struct nfs4_clnt_odstate are always NULL.
+ */
+static struct nfs4_clnt_odstate *
+alloc_clnt_odstate(struct nfs4_client *clp)
+{
+	struct nfs4_clnt_odstate *co;
+
+	co = kmem_cache_zalloc(odstate_slab, GFP_KERNEL);
+	if (co) {
+		co->co_client = clp;
+		refcount_set(&co->co_odcount, 1);
+	}
+	return co;
+}
+
+static void
+hash_clnt_odstate_locked(struct nfs4_clnt_odstate *co)
+{
+	struct nfs4_file *fp = co->co_file;
+
+	lockdep_assert_held(&fp->fi_lock);
+	list_add(&co->co_perfile, &fp->fi_clnt_odstate);
+}
+
+static inline void
+get_clnt_odstate(struct nfs4_clnt_odstate *co)
+{
+	if (co)
+		refcount_inc(&co->co_odcount);
+}
+
+static void
+put_clnt_odstate(struct nfs4_clnt_odstate *co)
+{
+	struct nfs4_file *fp;
+
+	if (!co)
+		return;
+
+	fp = co->co_file;
+	if (refcount_dec_and_lock(&co->co_odcount, &fp->fi_lock)) {
+		list_del(&co->co_perfile);
+		spin_unlock(&fp->fi_lock);
+
+		nfsd4_return_all_file_layouts(co->co_client, fp);
+		kmem_cache_free(odstate_slab, co);
+	}
+}
+
+static struct nfs4_clnt_odstate *
+find_or_hash_clnt_odstate(struct nfs4_file *fp, struct nfs4_clnt_odstate *new)
+{
+	struct nfs4_clnt_odstate *co;
+	struct nfs4_client *cl;
+
+	if (!new)
+		return NULL;
+
+	cl = new->co_client;
+
+	spin_lock(&fp->fi_lock);
+	list_for_each_entry(co, &fp->fi_clnt_odstate, co_perfile) {
+		if (co->co_client == cl) {
+			get_clnt_odstate(co);
+			goto out;
+		}
+	}
+	co = new;
+	co->co_file = fp;
+	hash_clnt_odstate_locked(new);
+out:
+	spin_unlock(&fp->fi_lock);
+	return co;
+}
+
+struct nfs4_stid *nfs4_alloc_stid(struct nfs4_client *cl, struct kmem_cache *slab,
+				  void (*sc_free)(struct nfs4_stid *))
+{
+	struct nfs4_stid *stid;
+	int new_id;
+
+	stid = kmem_cache_zalloc(slab, GFP_KERNEL);
+	if (!stid)
+		return NULL;
+
+	idr_preload(GFP_KERNEL);
+	spin_lock(&cl->cl_lock);
+	/* Reserving 0 for start of file in nfsdfs "states" file: */
+	new_id = idr_alloc_cyclic(&cl->cl_stateids, stid, 1, 0, GFP_NOWAIT);
+	spin_unlock(&cl->cl_lock);
+	idr_preload_end();
+	if (new_id < 0)
+		goto out_free;
+
+	stid->sc_free = sc_free;
+	stid->sc_client = cl;
+	stid->sc_stateid.si_opaque.so_id = new_id;
+	stid->sc_stateid.si_opaque.so_clid = cl->cl_clientid;
+	/* Will be incremented before return to client: */
+	refcount_set(&stid->sc_count, 1);
+	spin_lock_init(&stid->sc_lock);
+	INIT_LIST_HEAD(&stid->sc_cp_list);
+
+	/*
+	 * It shouldn't be a problem to reuse an opaque stateid value.
+	 * I don't think it is for 4.1.  But with 4.0 I worry that, for
+	 * example, a stray write retransmission could be accepted by
+	 * the server when it should have been rejected.  Therefore,
+	 * adopt a trick from the sctp code to attempt to maximize the
+	 * amount of time until an id is reused, by ensuring they always
+	 * "increase" (mod INT_MAX):
+	 */
+	return stid;
+out_free:
+	kmem_cache_free(slab, stid);
+	return NULL;
+}
+
+/*
+ * Create a unique stateid_t to represent each COPY.
+ */
+static int nfs4_init_cp_state(struct nfsd_net *nn, copy_stateid_t *stid,
+			      unsigned char sc_type)
+{
+	int new_id;
+
+	stid->stid.si_opaque.so_clid.cl_boot = (u32)nn->boot_time;
+	stid->stid.si_opaque.so_clid.cl_id = nn->s2s_cp_cl_id;
+	stid->sc_type = sc_type;
+
+	idr_preload(GFP_KERNEL);
+	spin_lock(&nn->s2s_cp_lock);
+	new_id = idr_alloc_cyclic(&nn->s2s_cp_stateids, stid, 0, 0, GFP_NOWAIT);
+	stid->stid.si_opaque.so_id = new_id;
+	stid->stid.si_generation = 1;
+	spin_unlock(&nn->s2s_cp_lock);
+	idr_preload_end();
+	if (new_id < 0)
+		return 0;
+	return 1;
+}
+
+int nfs4_init_copy_state(struct nfsd_net *nn, struct nfsd4_copy *copy)
+{
+	return nfs4_init_cp_state(nn, &copy->cp_stateid, NFS4_COPY_STID);
+}
+
+struct nfs4_cpntf_state *nfs4_alloc_init_cpntf_state(struct nfsd_net *nn,
+						     struct nfs4_stid *p_stid)
+{
+	struct nfs4_cpntf_state *cps;
+
+	cps = kzalloc(sizeof(struct nfs4_cpntf_state), GFP_KERNEL);
+	if (!cps)
+		return NULL;
+	cps->cpntf_time = ktime_get_boottime_seconds();
+	refcount_set(&cps->cp_stateid.sc_count, 1);
+	if (!nfs4_init_cp_state(nn, &cps->cp_stateid, NFS4_COPYNOTIFY_STID))
+		goto out_free;
+	spin_lock(&nn->s2s_cp_lock);
+	list_add(&cps->cp_list, &p_stid->sc_cp_list);
+	spin_unlock(&nn->s2s_cp_lock);
+	return cps;
+out_free:
+	kfree(cps);
+	return NULL;
+}
+
+void nfs4_free_copy_state(struct nfsd4_copy *copy)
+{
+	struct nfsd_net *nn;
+
+	WARN_ON_ONCE(copy->cp_stateid.sc_type != NFS4_COPY_STID);
+	nn = net_generic(copy->cp_clp->net, nfsd_net_id);
+	spin_lock(&nn->s2s_cp_lock);
+	idr_remove(&nn->s2s_cp_stateids,
+		   copy->cp_stateid.stid.si_opaque.so_id);
+	spin_unlock(&nn->s2s_cp_lock);
+}
+
+static void nfs4_free_cpntf_statelist(struct net *net, struct nfs4_stid *stid)
+{
+	struct nfs4_cpntf_state *cps;
+	struct nfsd_net *nn;
+
+	nn = net_generic(net, nfsd_net_id);
+	spin_lock(&nn->s2s_cp_lock);
+	while (!list_empty(&stid->sc_cp_list)) {
+		cps = list_first_entry(&stid->sc_cp_list,
+				       struct nfs4_cpntf_state, cp_list);
+		_free_cpntf_state_locked(nn, cps);
+	}
+	spin_unlock(&nn->s2s_cp_lock);
+}
+
+static struct nfs4_ol_stateid * nfs4_alloc_open_stateid(struct nfs4_client *clp)
+{
+	struct nfs4_stid *stid;
+
+	stid = nfs4_alloc_stid(clp, stateid_slab, nfs4_free_ol_stateid);
+	if (!stid)
+		return NULL;
+
+	return openlockstateid(stid);
+}
+
+static void nfs4_free_deleg(struct nfs4_stid *stid)
+{
+	WARN_ON(!list_empty(&stid->sc_cp_list));
+	kmem_cache_free(deleg_slab, stid);
+	atomic_long_dec(&num_delegations);
+}
+
+/*
+ * When we recall a delegation, we should be careful not to hand it
+ * out again straight away.
+ * To ensure this we keep a pair of bloom filters ('new' and 'old')
+ * in which the filehandles of recalled delegations are "stored".
+ * If a filehandle appear in either filter, a delegation is blocked.
+ * When a delegation is recalled, the filehandle is stored in the "new"
+ * filter.
+ * Every 30 seconds we swap the filters and clear the "new" one,
+ * unless both are empty of course.
+ *
+ * Each filter is 256 bits.  We hash the filehandle to 32bit and use the
+ * low 3 bytes as hash-table indices.
+ *
+ * 'blocked_delegations_lock', which is always taken in block_delegations(),
+ * is used to manage concurrent access.  Testing does not need the lock
+ * except when swapping the two filters.
+ */
+static DEFINE_SPINLOCK(blocked_delegations_lock);
+static struct bloom_pair {
+	int	entries, old_entries;
+	time64_t swap_time;
+	int	new; /* index into 'set' */
+	DECLARE_BITMAP(set[2], 256);
+} blocked_delegations;
+
+static int delegation_blocked(struct knfsd_fh *fh)
+{
+	u32 hash;
+	struct bloom_pair *bd = &blocked_delegations;
+
+	if (bd->entries == 0)
+		return 0;
+	if (ktime_get_seconds() - bd->swap_time > 30) {
+		spin_lock(&blocked_delegations_lock);
+		if (ktime_get_seconds() - bd->swap_time > 30) {
+			bd->entries -= bd->old_entries;
+			bd->old_entries = bd->entries;
+			memset(bd->set[bd->new], 0,
+			       sizeof(bd->set[0]));
+			bd->new = 1-bd->new;
+			bd->swap_time = ktime_get_seconds();
+		}
+		spin_unlock(&blocked_delegations_lock);
+	}
+	hash = jhash(&fh->fh_base, fh->fh_size, 0);
+	if (test_bit(hash&255, bd->set[0]) &&
+	    test_bit((hash>>8)&255, bd->set[0]) &&
+	    test_bit((hash>>16)&255, bd->set[0]))
+		return 1;
+
+	if (test_bit(hash&255, bd->set[1]) &&
+	    test_bit((hash>>8)&255, bd->set[1]) &&
+	    test_bit((hash>>16)&255, bd->set[1]))
+		return 1;
+
+	return 0;
+}
+
+static void block_delegations(struct knfsd_fh *fh)
+{
+	u32 hash;
+	struct bloom_pair *bd = &blocked_delegations;
+
+	hash = jhash(&fh->fh_base, fh->fh_size, 0);
+
+	spin_lock(&blocked_delegations_lock);
+	__set_bit(hash&255, bd->set[bd->new]);
+	__set_bit((hash>>8)&255, bd->set[bd->new]);
+	__set_bit((hash>>16)&255, bd->set[bd->new]);
+	if (bd->entries == 0)
+		bd->swap_time = ktime_get_seconds();
+	bd->entries += 1;
+	spin_unlock(&blocked_delegations_lock);
+}
+
+static struct nfs4_delegation *
+alloc_init_deleg(struct nfs4_client *clp, struct nfs4_file *fp,
+		 struct svc_fh *current_fh,
+		 struct nfs4_clnt_odstate *odstate)
+{
+	struct nfs4_delegation *dp;
+	long n;
+
+	dprintk("NFSD alloc_init_deleg\n");
+	n = atomic_long_inc_return(&num_delegations);
+	if (n < 0 || n > max_delegations)
+		goto out_dec;
+	if (delegation_blocked(&current_fh->fh_handle))
+		goto out_dec;
+	dp = delegstateid(nfs4_alloc_stid(clp, deleg_slab, nfs4_free_deleg));
+	if (dp == NULL)
+		goto out_dec;
+
+	/*
+	 * delegation seqid's are never incremented.  The 4.1 special
+	 * meaning of seqid 0 isn't meaningful, really, but let's avoid
+	 * 0 anyway just for consistency and use 1:
+	 */
+	dp->dl_stid.sc_stateid.si_generation = 1;
+	INIT_LIST_HEAD(&dp->dl_perfile);
+	INIT_LIST_HEAD(&dp->dl_perclnt);
+	INIT_LIST_HEAD(&dp->dl_recall_lru);
+	dp->dl_clnt_odstate = odstate;
+	get_clnt_odstate(odstate);
+	dp->dl_type = NFS4_OPEN_DELEGATE_READ;
+	dp->dl_retries = 1;
+	nfsd4_init_cb(&dp->dl_recall, dp->dl_stid.sc_client,
+		      &nfsd4_cb_recall_ops, NFSPROC4_CLNT_CB_RECALL);
+	get_nfs4_file(fp);
+	dp->dl_stid.sc_file = fp;
+	return dp;
+out_dec:
+	atomic_long_dec(&num_delegations);
+	return NULL;
+}
+
+void
+nfs4_put_stid(struct nfs4_stid *s)
+{
+	struct nfs4_file *fp = s->sc_file;
+	struct nfs4_client *clp = s->sc_client;
+
+	might_lock(&clp->cl_lock);
+
+	if (!refcount_dec_and_lock(&s->sc_count, &clp->cl_lock)) {
+		wake_up_all(&close_wq);
+		return;
+	}
+	idr_remove(&clp->cl_stateids, s->sc_stateid.si_opaque.so_id);
+	nfs4_free_cpntf_statelist(clp->net, s);
+	spin_unlock(&clp->cl_lock);
+	s->sc_free(s);
+	if (fp)
+		put_nfs4_file(fp);
+}
+
+void
+nfs4_inc_and_copy_stateid(stateid_t *dst, struct nfs4_stid *stid)
+{
+	stateid_t *src = &stid->sc_stateid;
+
+	spin_lock(&stid->sc_lock);
+	if (unlikely(++src->si_generation == 0))
+		src->si_generation = 1;
+	memcpy(dst, src, sizeof(*dst));
+	spin_unlock(&stid->sc_lock);
+}
+
+static void put_deleg_file(struct nfs4_file *fp)
+{
+	struct nfsd_file *nf = NULL;
+
+	spin_lock(&fp->fi_lock);
+	if (--fp->fi_delegees == 0)
+		swap(nf, fp->fi_deleg_file);
+	spin_unlock(&fp->fi_lock);
+
+	if (nf)
+		nfsd_file_put(nf);
+}
+
+static void nfs4_unlock_deleg_lease(struct nfs4_delegation *dp)
+{
+	struct nfs4_file *fp = dp->dl_stid.sc_file;
+	struct nfsd_file *nf = fp->fi_deleg_file;
+
+	WARN_ON_ONCE(!fp->fi_delegees);
+
+	vfs_setlease(nf->nf_file, F_UNLCK, NULL, (void **)&dp);
+	put_deleg_file(fp);
+}
+
+static void destroy_unhashed_deleg(struct nfs4_delegation *dp)
+{
+	put_clnt_odstate(dp->dl_clnt_odstate);
+	nfs4_unlock_deleg_lease(dp);
+	nfs4_put_stid(&dp->dl_stid);
+}
+
+void nfs4_unhash_stid(struct nfs4_stid *s)
+{
+	s->sc_type = 0;
+}
+
+/**
+ * nfs4_delegation_exists - Discover if this delegation already exists
+ * @clp:     a pointer to the nfs4_client we're granting a delegation to
+ * @fp:      a pointer to the nfs4_file we're granting a delegation on
+ *
+ * Return:
+ *      On success: true iff an existing delegation is found
+ */
+
+static bool
+nfs4_delegation_exists(struct nfs4_client *clp, struct nfs4_file *fp)
+{
+	struct nfs4_delegation *searchdp = NULL;
+	struct nfs4_client *searchclp = NULL;
+
+	lockdep_assert_held(&state_lock);
+	lockdep_assert_held(&fp->fi_lock);
+
+	list_for_each_entry(searchdp, &fp->fi_delegations, dl_perfile) {
+		searchclp = searchdp->dl_stid.sc_client;
+		if (clp == searchclp) {
+			return true;
+		}
+	}
+	return false;
+}
+
+/**
+ * hash_delegation_locked - Add a delegation to the appropriate lists
+ * @dp:     a pointer to the nfs4_delegation we are adding.
+ * @fp:     a pointer to the nfs4_file we're granting a delegation on
+ *
+ * Return:
+ *      On success: NULL if the delegation was successfully hashed.
+ *
+ *      On error: -EAGAIN if one was previously granted to this
+ *                 nfs4_client for this nfs4_file. Delegation is not hashed.
+ *
+ */
+
+static int
+hash_delegation_locked(struct nfs4_delegation *dp, struct nfs4_file *fp)
+{
+	struct nfs4_client *clp = dp->dl_stid.sc_client;
+
+	lockdep_assert_held(&state_lock);
+	lockdep_assert_held(&fp->fi_lock);
+
+	if (nfs4_delegation_exists(clp, fp))
+		return -EAGAIN;
+	refcount_inc(&dp->dl_stid.sc_count);
+	dp->dl_stid.sc_type = NFS4_DELEG_STID;
+	list_add(&dp->dl_perfile, &fp->fi_delegations);
+	list_add(&dp->dl_perclnt, &clp->cl_delegations);
+	return 0;
+}
+
+static bool delegation_hashed(struct nfs4_delegation *dp)
+{
+	return !(list_empty(&dp->dl_perfile));
+}
+
+static bool
+unhash_delegation_locked(struct nfs4_delegation *dp)
+{
+	struct nfs4_file *fp = dp->dl_stid.sc_file;
+
+	lockdep_assert_held(&state_lock);
+
+	if (!delegation_hashed(dp))
+		return false;
+
+	dp->dl_stid.sc_type = NFS4_CLOSED_DELEG_STID;
+	/* Ensure that deleg break won't try to requeue it */
+	++dp->dl_time;
+	spin_lock(&fp->fi_lock);
+	list_del_init(&dp->dl_perclnt);
+	list_del_init(&dp->dl_recall_lru);
+	list_del_init(&dp->dl_perfile);
+	spin_unlock(&fp->fi_lock);
+	return true;
+}
+
+static void destroy_delegation(struct nfs4_delegation *dp)
+{
+	bool unhashed;
+
+	spin_lock(&state_lock);
+	unhashed = unhash_delegation_locked(dp);
+	spin_unlock(&state_lock);
+	if (unhashed)
+		destroy_unhashed_deleg(dp);
+}
+
+static void revoke_delegation(struct nfs4_delegation *dp)
+{
+	struct nfs4_client *clp = dp->dl_stid.sc_client;
+
+	WARN_ON(!list_empty(&dp->dl_recall_lru));
+
+	if (clp->cl_minorversion) {
+		spin_lock(&clp->cl_lock);
+		dp->dl_stid.sc_type = NFS4_REVOKED_DELEG_STID;
+		refcount_inc(&dp->dl_stid.sc_count);
+		list_add(&dp->dl_recall_lru, &clp->cl_revoked);
+		spin_unlock(&clp->cl_lock);
+	}
+	destroy_unhashed_deleg(dp);
+}
+
+/* 
+ * SETCLIENTID state 
+ */
+
+static unsigned int clientid_hashval(u32 id)
+{
+	return id & CLIENT_HASH_MASK;
+}
+
+static unsigned int clientstr_hashval(struct xdr_netobj name)
+{
+	return opaque_hashval(name.data, 8) & CLIENT_HASH_MASK;
+}
+
+/*
+ * We store the NONE, READ, WRITE, and BOTH bits separately in the
+ * st_{access,deny}_bmap field of the stateid, in order to track not
+ * only what share bits are currently in force, but also what
+ * combinations of share bits previous opens have used.  This allows us
+ * to enforce the recommendation of rfc 3530 14.2.19 that the server
+ * return an error if the client attempt to downgrade to a combination
+ * of share bits not explicable by closing some of its previous opens.
+ *
+ * XXX: This enforcement is actually incomplete, since we don't keep
+ * track of access/deny bit combinations; so, e.g., we allow:
+ *
+ *	OPEN allow read, deny write
+ *	OPEN allow both, deny none
+ *	DOWNGRADE allow read, deny none
+ *
+ * which we should reject.
+ */
+static unsigned int
+bmap_to_share_mode(unsigned long bmap) {
+	int i;
+	unsigned int access = 0;
+
+	for (i = 1; i < 4; i++) {
+		if (test_bit(i, &bmap))
+			access |= i;
+	}
+	return access;
+}
+
+/* set share access for a given stateid */
+static inline void
+set_access(u32 access, struct nfs4_ol_stateid *stp)
+{
+	unsigned char mask = 1 << access;
+
+	WARN_ON_ONCE(access > NFS4_SHARE_ACCESS_BOTH);
+	stp->st_access_bmap |= mask;
+}
+
+/* clear share access for a given stateid */
+static inline void
+clear_access(u32 access, struct nfs4_ol_stateid *stp)
+{
+	unsigned char mask = 1 << access;
+
+	WARN_ON_ONCE(access > NFS4_SHARE_ACCESS_BOTH);
+	stp->st_access_bmap &= ~mask;
+}
+
+/* test whether a given stateid has access */
+static inline bool
+test_access(u32 access, struct nfs4_ol_stateid *stp)
+{
+	unsigned char mask = 1 << access;
+
+	return (bool)(stp->st_access_bmap & mask);
+}
+
+/* set share deny for a given stateid */
+static inline void
+set_deny(u32 deny, struct nfs4_ol_stateid *stp)
+{
+	unsigned char mask = 1 << deny;
+
+	WARN_ON_ONCE(deny > NFS4_SHARE_DENY_BOTH);
+	stp->st_deny_bmap |= mask;
+}
+
+/* clear share deny for a given stateid */
+static inline void
+clear_deny(u32 deny, struct nfs4_ol_stateid *stp)
+{
+	unsigned char mask = 1 << deny;
+
+	WARN_ON_ONCE(deny > NFS4_SHARE_DENY_BOTH);
+	stp->st_deny_bmap &= ~mask;
+}
+
+/* test whether a given stateid is denying specific access */
+static inline bool
+test_deny(u32 deny, struct nfs4_ol_stateid *stp)
+{
+	unsigned char mask = 1 << deny;
+
+	return (bool)(stp->st_deny_bmap & mask);
+}
+
+static int nfs4_access_to_omode(u32 access)
+{
+	switch (access & NFS4_SHARE_ACCESS_BOTH) {
+	case NFS4_SHARE_ACCESS_READ:
+		return O_RDONLY;
+	case NFS4_SHARE_ACCESS_WRITE:
+		return O_WRONLY;
+	case NFS4_SHARE_ACCESS_BOTH:
+		return O_RDWR;
+	}
+	WARN_ON_ONCE(1);
+	return O_RDONLY;
+}
+
+/*
+ * A stateid that had a deny mode associated with it is being released
+ * or downgraded. Recalculate the deny mode on the file.
+ */
+static void
+recalculate_deny_mode(struct nfs4_file *fp)
+{
+	struct nfs4_ol_stateid *stp;
+
+	spin_lock(&fp->fi_lock);
+	fp->fi_share_deny = 0;
+	list_for_each_entry(stp, &fp->fi_stateids, st_perfile)
+		fp->fi_share_deny |= bmap_to_share_mode(stp->st_deny_bmap);
+	spin_unlock(&fp->fi_lock);
+}
+
+static void
+reset_union_bmap_deny(u32 deny, struct nfs4_ol_stateid *stp)
+{
+	int i;
+	bool change = false;
+
+	for (i = 1; i < 4; i++) {
+		if ((i & deny) != i) {
+			change = true;
+			clear_deny(i, stp);
+		}
+	}
+
+	/* Recalculate per-file deny mode if there was a change */
+	if (change)
+		recalculate_deny_mode(stp->st_stid.sc_file);
+}
+
+/* release all access and file references for a given stateid */
+static void
+release_all_access(struct nfs4_ol_stateid *stp)
+{
+	int i;
+	struct nfs4_file *fp = stp->st_stid.sc_file;
+
+	if (fp && stp->st_deny_bmap != 0)
+		recalculate_deny_mode(fp);
+
+	for (i = 1; i < 4; i++) {
+		if (test_access(i, stp))
+			nfs4_file_put_access(stp->st_stid.sc_file, i);
+		clear_access(i, stp);
+	}
+}
+
+static inline void nfs4_free_stateowner(struct nfs4_stateowner *sop)
+{
+	kfree(sop->so_owner.data);
+	sop->so_ops->so_free(sop);
+}
+
+static void nfs4_put_stateowner(struct nfs4_stateowner *sop)
+{
+	struct nfs4_client *clp = sop->so_client;
+
+	might_lock(&clp->cl_lock);
+
+	if (!atomic_dec_and_lock(&sop->so_count, &clp->cl_lock))
+		return;
+	sop->so_ops->so_unhash(sop);
+	spin_unlock(&clp->cl_lock);
+	nfs4_free_stateowner(sop);
+}
+
+static bool
+nfs4_ol_stateid_unhashed(const struct nfs4_ol_stateid *stp)
+{
+	return list_empty(&stp->st_perfile);
+}
+
+static bool unhash_ol_stateid(struct nfs4_ol_stateid *stp)
+{
+	struct nfs4_file *fp = stp->st_stid.sc_file;
+
+	lockdep_assert_held(&stp->st_stateowner->so_client->cl_lock);
+
+	if (list_empty(&stp->st_perfile))
+		return false;
+
+	spin_lock(&fp->fi_lock);
+	list_del_init(&stp->st_perfile);
+	spin_unlock(&fp->fi_lock);
+	list_del(&stp->st_perstateowner);
+	return true;
+}
+
+static void nfs4_free_ol_stateid(struct nfs4_stid *stid)
+{
+	struct nfs4_ol_stateid *stp = openlockstateid(stid);
+
+	put_clnt_odstate(stp->st_clnt_odstate);
+	release_all_access(stp);
+	if (stp->st_stateowner)
+		nfs4_put_stateowner(stp->st_stateowner);
+	WARN_ON(!list_empty(&stid->sc_cp_list));
+	kmem_cache_free(stateid_slab, stid);
+}
+
+static void nfs4_free_lock_stateid(struct nfs4_stid *stid)
+{
+	struct nfs4_ol_stateid *stp = openlockstateid(stid);
+	struct nfs4_lockowner *lo = lockowner(stp->st_stateowner);
+	struct nfsd_file *nf;
+
+	nf = find_any_file(stp->st_stid.sc_file);
+	if (nf) {
+		get_file(nf->nf_file);
+		filp_close(nf->nf_file, (fl_owner_t)lo);
+		nfsd_file_put(nf);
+	}
+	nfs4_free_ol_stateid(stid);
+}
+
+/*
+ * Put the persistent reference to an already unhashed generic stateid, while
+ * holding the cl_lock. If it's the last reference, then put it onto the
+ * reaplist for later destruction.
+ */
+static void put_ol_stateid_locked(struct nfs4_ol_stateid *stp,
+				       struct list_head *reaplist)
+{
+	struct nfs4_stid *s = &stp->st_stid;
+	struct nfs4_client *clp = s->sc_client;
+
+	lockdep_assert_held(&clp->cl_lock);
+
+	WARN_ON_ONCE(!list_empty(&stp->st_locks));
+
+	if (!refcount_dec_and_test(&s->sc_count)) {
+		wake_up_all(&close_wq);
+		return;
+	}
+
+	idr_remove(&clp->cl_stateids, s->sc_stateid.si_opaque.so_id);
+	list_add(&stp->st_locks, reaplist);
+}
+
+static bool unhash_lock_stateid(struct nfs4_ol_stateid *stp)
+{
+	lockdep_assert_held(&stp->st_stid.sc_client->cl_lock);
+
+	if (!unhash_ol_stateid(stp))
+		return false;
+	list_del_init(&stp->st_locks);
+	nfs4_unhash_stid(&stp->st_stid);
+	return true;
+}
+
+static void release_lock_stateid(struct nfs4_ol_stateid *stp)
+{
+	struct nfs4_client *clp = stp->st_stid.sc_client;
+	bool unhashed;
+
+	spin_lock(&clp->cl_lock);
+	unhashed = unhash_lock_stateid(stp);
+	spin_unlock(&clp->cl_lock);
+	if (unhashed)
+		nfs4_put_stid(&stp->st_stid);
+}
+
+static void unhash_lockowner_locked(struct nfs4_lockowner *lo)
+{
+	struct nfs4_client *clp = lo->lo_owner.so_client;
+
+	lockdep_assert_held(&clp->cl_lock);
+
+	list_del_init(&lo->lo_owner.so_strhash);
+}
+
+/*
+ * Free a list of generic stateids that were collected earlier after being
+ * fully unhashed.
+ */
+static void
+free_ol_stateid_reaplist(struct list_head *reaplist)
+{
+	struct nfs4_ol_stateid *stp;
+	struct nfs4_file *fp;
+
+	might_sleep();
+
+	while (!list_empty(reaplist)) {
+		stp = list_first_entry(reaplist, struct nfs4_ol_stateid,
+				       st_locks);
+		list_del(&stp->st_locks);
+		fp = stp->st_stid.sc_file;
+		stp->st_stid.sc_free(&stp->st_stid);
+		if (fp)
+			put_nfs4_file(fp);
+	}
+}
+
+static void release_open_stateid_locks(struct nfs4_ol_stateid *open_stp,
+				       struct list_head *reaplist)
+{
+	struct nfs4_ol_stateid *stp;
+
+	lockdep_assert_held(&open_stp->st_stid.sc_client->cl_lock);
+
+	while (!list_empty(&open_stp->st_locks)) {
+		stp = list_entry(open_stp->st_locks.next,
+				struct nfs4_ol_stateid, st_locks);
+		WARN_ON(!unhash_lock_stateid(stp));
+		put_ol_stateid_locked(stp, reaplist);
+	}
+}
+
+static bool unhash_open_stateid(struct nfs4_ol_stateid *stp,
+				struct list_head *reaplist)
+{
+	lockdep_assert_held(&stp->st_stid.sc_client->cl_lock);
+
+	if (!unhash_ol_stateid(stp))
+		return false;
+	release_open_stateid_locks(stp, reaplist);
+	return true;
+}
+
+static void release_open_stateid(struct nfs4_ol_stateid *stp)
+{
+	LIST_HEAD(reaplist);
+
+	spin_lock(&stp->st_stid.sc_client->cl_lock);
+	if (unhash_open_stateid(stp, &reaplist))
+		put_ol_stateid_locked(stp, &reaplist);
+	spin_unlock(&stp->st_stid.sc_client->cl_lock);
+	free_ol_stateid_reaplist(&reaplist);
+}
+
+static void unhash_openowner_locked(struct nfs4_openowner *oo)
+{
+	struct nfs4_client *clp = oo->oo_owner.so_client;
+
+	lockdep_assert_held(&clp->cl_lock);
+
+	list_del_init(&oo->oo_owner.so_strhash);
+	list_del_init(&oo->oo_perclient);
+}
+
+static void release_last_closed_stateid(struct nfs4_openowner *oo)
+{
+	struct nfsd_net *nn = net_generic(oo->oo_owner.so_client->net,
+					  nfsd_net_id);
+	struct nfs4_ol_stateid *s;
+
+	spin_lock(&nn->client_lock);
+	s = oo->oo_last_closed_stid;
+	if (s) {
+		list_del_init(&oo->oo_close_lru);
+		oo->oo_last_closed_stid = NULL;
+	}
+	spin_unlock(&nn->client_lock);
+	if (s)
+		nfs4_put_stid(&s->st_stid);
+}
+
+static void release_openowner(struct nfs4_openowner *oo)
+{
+	struct nfs4_ol_stateid *stp;
+	struct nfs4_client *clp = oo->oo_owner.so_client;
+	struct list_head reaplist;
+
+	INIT_LIST_HEAD(&reaplist);
+
+	spin_lock(&clp->cl_lock);
+	unhash_openowner_locked(oo);
+	while (!list_empty(&oo->oo_owner.so_stateids)) {
+		stp = list_first_entry(&oo->oo_owner.so_stateids,
+				struct nfs4_ol_stateid, st_perstateowner);
+		if (unhash_open_stateid(stp, &reaplist))
+			put_ol_stateid_locked(stp, &reaplist);
+	}
+	spin_unlock(&clp->cl_lock);
+	free_ol_stateid_reaplist(&reaplist);
+	release_last_closed_stateid(oo);
+	nfs4_put_stateowner(&oo->oo_owner);
+}
+
+static inline int
+hash_sessionid(struct nfs4_sessionid *sessionid)
+{
+	struct nfsd4_sessionid *sid = (struct nfsd4_sessionid *)sessionid;
+
+	return sid->sequence % SESSION_HASH_SIZE;
+}
+
+#ifdef CONFIG_SUNRPC_DEBUG
+static inline void
+dump_sessionid(const char *fn, struct nfs4_sessionid *sessionid)
+{
+	u32 *ptr = (u32 *)(&sessionid->data[0]);
+	dprintk("%s: %u:%u:%u:%u\n", fn, ptr[0], ptr[1], ptr[2], ptr[3]);
+}
+#else
+static inline void
+dump_sessionid(const char *fn, struct nfs4_sessionid *sessionid)
+{
+}
+#endif
+
+/*
+ * Bump the seqid on cstate->replay_owner, and clear replay_owner if it
+ * won't be used for replay.
+ */
+void nfsd4_bump_seqid(struct nfsd4_compound_state *cstate, __be32 nfserr)
+{
+	struct nfs4_stateowner *so = cstate->replay_owner;
+
+	if (nfserr == nfserr_replay_me)
+		return;
+
+	if (!seqid_mutating_err(ntohl(nfserr))) {
+		nfsd4_cstate_clear_replay(cstate);
+		return;
+	}
+	if (!so)
+		return;
+	if (so->so_is_open_owner)
+		release_last_closed_stateid(openowner(so));
+	so->so_seqid++;
+	return;
+}
+
+static void
+gen_sessionid(struct nfsd4_session *ses)
+{
+	struct nfs4_client *clp = ses->se_client;
+	struct nfsd4_sessionid *sid;
+
+	sid = (struct nfsd4_sessionid *)ses->se_sessionid.data;
+	sid->clientid = clp->cl_clientid;
+	sid->sequence = current_sessionid++;
+	sid->reserved = 0;
+}
+
+/*
+ * The protocol defines ca_maxresponssize_cached to include the size of
+ * the rpc header, but all we need to cache is the data starting after
+ * the end of the initial SEQUENCE operation--the rest we regenerate
+ * each time.  Therefore we can advertise a ca_maxresponssize_cached
+ * value that is the number of bytes in our cache plus a few additional
+ * bytes.  In order to stay on the safe side, and not promise more than
+ * we can cache, those additional bytes must be the minimum possible: 24
+ * bytes of rpc header (xid through accept state, with AUTH_NULL
+ * verifier), 12 for the compound header (with zero-length tag), and 44
+ * for the SEQUENCE op response:
+ */
+#define NFSD_MIN_HDR_SEQ_SZ  (24 + 12 + 44)
+
+static void
+free_session_slots(struct nfsd4_session *ses)
+{
+	int i;
+
+	for (i = 0; i < ses->se_fchannel.maxreqs; i++) {
+		free_svc_cred(&ses->se_slots[i]->sl_cred);
+		kfree(ses->se_slots[i]);
+	}
+}
+
+/*
+ * We don't actually need to cache the rpc and session headers, so we
+ * can allocate a little less for each slot:
+ */
+static inline u32 slot_bytes(struct nfsd4_channel_attrs *ca)
+{
+	u32 size;
+
+	if (ca->maxresp_cached < NFSD_MIN_HDR_SEQ_SZ)
+		size = 0;
+	else
+		size = ca->maxresp_cached - NFSD_MIN_HDR_SEQ_SZ;
+	return size + sizeof(struct nfsd4_slot);
+}
+
+/*
+ * XXX: If we run out of reserved DRC memory we could (up to a point)
+ * re-negotiate active sessions and reduce their slot usage to make
+ * room for new connections. For now we just fail the create session.
+ */
+static u32 nfsd4_get_drc_mem(struct nfsd4_channel_attrs *ca, struct nfsd_net *nn)
+{
+	u32 slotsize = slot_bytes(ca);
+	u32 num = ca->maxreqs;
+	unsigned long avail, total_avail;
+	unsigned int scale_factor;
+
+	spin_lock(&nfsd_drc_lock);
+	if (nfsd_drc_max_mem > nfsd_drc_mem_used)
+		total_avail = nfsd_drc_max_mem - nfsd_drc_mem_used;
+	else
+		/* We have handed out more space than we chose in
+		 * set_max_drc() to allow.  That isn't really a
+		 * problem as long as that doesn't make us think we
+		 * have lots more due to integer overflow.
+		 */
+		total_avail = 0;
+	avail = min((unsigned long)NFSD_MAX_MEM_PER_SESSION, total_avail);
+	/*
+	 * Never use more than a fraction of the remaining memory,
+	 * unless it's the only way to give this client a slot.
+	 * The chosen fraction is either 1/8 or 1/number of threads,
+	 * whichever is smaller.  This ensures there are adequate
+	 * slots to support multiple clients per thread.
+	 * Give the client one slot even if that would require
+	 * over-allocation--it is better than failure.
+	 */
+	scale_factor = max_t(unsigned int, 8, nn->nfsd_serv->sv_nrthreads);
+
+	avail = clamp_t(unsigned long, avail, slotsize,
+			total_avail/scale_factor);
+	num = min_t(int, num, avail / slotsize);
+	num = max_t(int, num, 1);
+	nfsd_drc_mem_used += num * slotsize;
+	spin_unlock(&nfsd_drc_lock);
+
+	return num;
+}
+
+static void nfsd4_put_drc_mem(struct nfsd4_channel_attrs *ca)
+{
+	int slotsize = slot_bytes(ca);
+
+	spin_lock(&nfsd_drc_lock);
+	nfsd_drc_mem_used -= slotsize * ca->maxreqs;
+	spin_unlock(&nfsd_drc_lock);
+}
+
+static struct nfsd4_session *alloc_session(struct nfsd4_channel_attrs *fattrs,
+					   struct nfsd4_channel_attrs *battrs)
+{
+	int numslots = fattrs->maxreqs;
+	int slotsize = slot_bytes(fattrs);
+	struct nfsd4_session *new;
+	int mem, i;
+
+	BUILD_BUG_ON(NFSD_MAX_SLOTS_PER_SESSION * sizeof(struct nfsd4_slot *)
+			+ sizeof(struct nfsd4_session) > PAGE_SIZE);
+	mem = numslots * sizeof(struct nfsd4_slot *);
+
+	new = kzalloc(sizeof(*new) + mem, GFP_KERNEL);
+	if (!new)
+		return NULL;
+	/* allocate each struct nfsd4_slot and data cache in one piece */
+	for (i = 0; i < numslots; i++) {
+		new->se_slots[i] = kzalloc(slotsize, GFP_KERNEL);
+		if (!new->se_slots[i])
+			goto out_free;
+	}
+
+	memcpy(&new->se_fchannel, fattrs, sizeof(struct nfsd4_channel_attrs));
+	memcpy(&new->se_bchannel, battrs, sizeof(struct nfsd4_channel_attrs));
+
+	return new;
+out_free:
+	while (i--)
+		kfree(new->se_slots[i]);
+	kfree(new);
+	return NULL;
+}
+
+static void free_conn(struct nfsd4_conn *c)
+{
+	svc_xprt_put(c->cn_xprt);
+	kfree(c);
+}
+
+static void nfsd4_conn_lost(struct svc_xpt_user *u)
+{
+	struct nfsd4_conn *c = container_of(u, struct nfsd4_conn, cn_xpt_user);
+	struct nfs4_client *clp = c->cn_session->se_client;
+
+	spin_lock(&clp->cl_lock);
+	if (!list_empty(&c->cn_persession)) {
+		list_del(&c->cn_persession);
+		free_conn(c);
+	}
+	nfsd4_probe_callback(clp);
+	spin_unlock(&clp->cl_lock);
+}
+
+static struct nfsd4_conn *alloc_conn(struct svc_rqst *rqstp, u32 flags)
+{
+	struct nfsd4_conn *conn;
+
+	conn = kmalloc(sizeof(struct nfsd4_conn), GFP_KERNEL);
+	if (!conn)
+		return NULL;
+	svc_xprt_get(rqstp->rq_xprt);
+	conn->cn_xprt = rqstp->rq_xprt;
+	conn->cn_flags = flags;
+	INIT_LIST_HEAD(&conn->cn_xpt_user.list);
+	return conn;
+}
+
+static void __nfsd4_hash_conn(struct nfsd4_conn *conn, struct nfsd4_session *ses)
+{
+	conn->cn_session = ses;
+	list_add(&conn->cn_persession, &ses->se_conns);
+}
+
+static void nfsd4_hash_conn(struct nfsd4_conn *conn, struct nfsd4_session *ses)
+{
+	struct nfs4_client *clp = ses->se_client;
+
+	spin_lock(&clp->cl_lock);
+	__nfsd4_hash_conn(conn, ses);
+	spin_unlock(&clp->cl_lock);
+}
+
+static int nfsd4_register_conn(struct nfsd4_conn *conn)
+{
+	conn->cn_xpt_user.callback = nfsd4_conn_lost;
+	return register_xpt_user(conn->cn_xprt, &conn->cn_xpt_user);
+}
+
+static void nfsd4_init_conn(struct svc_rqst *rqstp, struct nfsd4_conn *conn, struct nfsd4_session *ses)
+{
+	int ret;
+
+	nfsd4_hash_conn(conn, ses);
+	ret = nfsd4_register_conn(conn);
+	if (ret)
+		/* oops; xprt is already down: */
+		nfsd4_conn_lost(&conn->cn_xpt_user);
+	/* We may have gained or lost a callback channel: */
+	nfsd4_probe_callback_sync(ses->se_client);
+}
+
+static struct nfsd4_conn *alloc_conn_from_crses(struct svc_rqst *rqstp, struct nfsd4_create_session *cses)
+{
+	u32 dir = NFS4_CDFC4_FORE;
+
+	if (cses->flags & SESSION4_BACK_CHAN)
+		dir |= NFS4_CDFC4_BACK;
+	return alloc_conn(rqstp, dir);
+}
+
+/* must be called under client_lock */
+static void nfsd4_del_conns(struct nfsd4_session *s)
+{
+	struct nfs4_client *clp = s->se_client;
+	struct nfsd4_conn *c;
+
+	spin_lock(&clp->cl_lock);
+	while (!list_empty(&s->se_conns)) {
+		c = list_first_entry(&s->se_conns, struct nfsd4_conn, cn_persession);
+		list_del_init(&c->cn_persession);
+		spin_unlock(&clp->cl_lock);
+
+		unregister_xpt_user(c->cn_xprt, &c->cn_xpt_user);
+		free_conn(c);
+
+		spin_lock(&clp->cl_lock);
+	}
+	spin_unlock(&clp->cl_lock);
+}
+
+static void __free_session(struct nfsd4_session *ses)
+{
+	free_session_slots(ses);
+	kfree(ses);
+}
+
+static void free_session(struct nfsd4_session *ses)
+{
+	nfsd4_del_conns(ses);
+	nfsd4_put_drc_mem(&ses->se_fchannel);
+	__free_session(ses);
+}
+
+static void init_session(struct svc_rqst *rqstp, struct nfsd4_session *new, struct nfs4_client *clp, struct nfsd4_create_session *cses)
+{
+	int idx;
+	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+
+	new->se_client = clp;
+	gen_sessionid(new);
+
+	INIT_LIST_HEAD(&new->se_conns);
+
+	new->se_cb_seq_nr = 1;
+	new->se_flags = cses->flags;
+	new->se_cb_prog = cses->callback_prog;
+	new->se_cb_sec = cses->cb_sec;
+	atomic_set(&new->se_ref, 0);
+	idx = hash_sessionid(&new->se_sessionid);
+	list_add(&new->se_hash, &nn->sessionid_hashtbl[idx]);
+	spin_lock(&clp->cl_lock);
+	list_add(&new->se_perclnt, &clp->cl_sessions);
+	spin_unlock(&clp->cl_lock);
+
+	{
+		struct sockaddr *sa = svc_addr(rqstp);
+		/*
+		 * This is a little silly; with sessions there's no real
+		 * use for the callback address.  Use the peer address
+		 * as a reasonable default for now, but consider fixing
+		 * the rpc client not to require an address in the
+		 * future:
+		 */
+		rpc_copy_addr((struct sockaddr *)&clp->cl_cb_conn.cb_addr, sa);
+		clp->cl_cb_conn.cb_addrlen = svc_addr_len(sa);
+	}
+}
+
+/* caller must hold client_lock */
+static struct nfsd4_session *
+__find_in_sessionid_hashtbl(struct nfs4_sessionid *sessionid, struct net *net)
+{
+	struct nfsd4_session *elem;
+	int idx;
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	lockdep_assert_held(&nn->client_lock);
+
+	dump_sessionid(__func__, sessionid);
+	idx = hash_sessionid(sessionid);
+	/* Search in the appropriate list */
+	list_for_each_entry(elem, &nn->sessionid_hashtbl[idx], se_hash) {
+		if (!memcmp(elem->se_sessionid.data, sessionid->data,
+			    NFS4_MAX_SESSIONID_LEN)) {
+			return elem;
+		}
+	}
+
+	dprintk("%s: session not found\n", __func__);
+	return NULL;
+}
+
+static struct nfsd4_session *
+find_in_sessionid_hashtbl(struct nfs4_sessionid *sessionid, struct net *net,
+		__be32 *ret)
+{
+	struct nfsd4_session *session;
+	__be32 status = nfserr_badsession;
+
+	session = __find_in_sessionid_hashtbl(sessionid, net);
+	if (!session)
+		goto out;
+	status = nfsd4_get_session_locked(session);
+	if (status)
+		session = NULL;
+out:
+	*ret = status;
+	return session;
+}
+
+/* caller must hold client_lock */
+static void
+unhash_session(struct nfsd4_session *ses)
+{
+	struct nfs4_client *clp = ses->se_client;
+	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+
+	lockdep_assert_held(&nn->client_lock);
+
+	list_del(&ses->se_hash);
+	spin_lock(&ses->se_client->cl_lock);
+	list_del(&ses->se_perclnt);
+	spin_unlock(&ses->se_client->cl_lock);
+}
+
+/* SETCLIENTID and SETCLIENTID_CONFIRM Helper functions */
+static int
+STALE_CLIENTID(clientid_t *clid, struct nfsd_net *nn)
+{
+	/*
+	 * We're assuming the clid was not given out from a boot
+	 * precisely 2^32 (about 136 years) before this one.  That seems
+	 * a safe assumption:
+	 */
+	if (clid->cl_boot == (u32)nn->boot_time)
+		return 0;
+	trace_nfsd_clid_stale(clid);
+	return 1;
+}
+
+/* 
+ * XXX Should we use a slab cache ?
+ * This type of memory management is somewhat inefficient, but we use it
+ * anyway since SETCLIENTID is not a common operation.
+ */
+static struct nfs4_client *alloc_client(struct xdr_netobj name)
+{
+	struct nfs4_client *clp;
+	int i;
+
+	clp = kmem_cache_zalloc(client_slab, GFP_KERNEL);
+	if (clp == NULL)
+		return NULL;
+	xdr_netobj_dup(&clp->cl_name, &name, GFP_KERNEL);
+	if (clp->cl_name.data == NULL)
+		goto err_no_name;
+	clp->cl_ownerstr_hashtbl = kmalloc_array(OWNER_HASH_SIZE,
+						 sizeof(struct list_head),
+						 GFP_KERNEL);
+	if (!clp->cl_ownerstr_hashtbl)
+		goto err_no_hashtbl;
+	for (i = 0; i < OWNER_HASH_SIZE; i++)
+		INIT_LIST_HEAD(&clp->cl_ownerstr_hashtbl[i]);
+	INIT_LIST_HEAD(&clp->cl_sessions);
+	idr_init(&clp->cl_stateids);
+	atomic_set(&clp->cl_rpc_users, 0);
+	clp->cl_cb_state = NFSD4_CB_UNKNOWN;
+	INIT_LIST_HEAD(&clp->cl_idhash);
+	INIT_LIST_HEAD(&clp->cl_openowners);
+	INIT_LIST_HEAD(&clp->cl_delegations);
+	INIT_LIST_HEAD(&clp->cl_lru);
+	INIT_LIST_HEAD(&clp->cl_revoked);
+#ifdef CONFIG_NFSD_PNFS
+	INIT_LIST_HEAD(&clp->cl_lo_states);
+#endif
+	INIT_LIST_HEAD(&clp->async_copies);
+	spin_lock_init(&clp->async_lock);
+	spin_lock_init(&clp->cl_lock);
+	rpc_init_wait_queue(&clp->cl_cb_waitq, "Backchannel slot table");
+	return clp;
+err_no_hashtbl:
+	kfree(clp->cl_name.data);
+err_no_name:
+	kmem_cache_free(client_slab, clp);
+	return NULL;
+}
+
+static void __free_client(struct kref *k)
+{
+	struct nfsdfs_client *c = container_of(k, struct nfsdfs_client, cl_ref);
+	struct nfs4_client *clp = container_of(c, struct nfs4_client, cl_nfsdfs);
+
+	free_svc_cred(&clp->cl_cred);
+	kfree(clp->cl_ownerstr_hashtbl);
+	kfree(clp->cl_name.data);
+	kfree(clp->cl_nii_domain.data);
+	kfree(clp->cl_nii_name.data);
+	idr_destroy(&clp->cl_stateids);
+	kmem_cache_free(client_slab, clp);
+}
+
+static void drop_client(struct nfs4_client *clp)
+{
+	kref_put(&clp->cl_nfsdfs.cl_ref, __free_client);
+}
+
+static void
+free_client(struct nfs4_client *clp)
+{
+	while (!list_empty(&clp->cl_sessions)) {
+		struct nfsd4_session *ses;
+		ses = list_entry(clp->cl_sessions.next, struct nfsd4_session,
+				se_perclnt);
+		list_del(&ses->se_perclnt);
+		WARN_ON_ONCE(atomic_read(&ses->se_ref));
+		free_session(ses);
+	}
+	rpc_destroy_wait_queue(&clp->cl_cb_waitq);
+	if (clp->cl_nfsd_dentry) {
+		nfsd_client_rmdir(clp->cl_nfsd_dentry);
+		clp->cl_nfsd_dentry = NULL;
+		wake_up_all(&expiry_wq);
+	}
+	drop_client(clp);
+}
+
+/* must be called under the client_lock */
+static void
+unhash_client_locked(struct nfs4_client *clp)
+{
+	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+	struct nfsd4_session *ses;
+
+	lockdep_assert_held(&nn->client_lock);
+
+	/* Mark the client as expired! */
+	clp->cl_time = 0;
+	/* Make it invisible */
+	if (!list_empty(&clp->cl_idhash)) {
+		list_del_init(&clp->cl_idhash);
+		if (test_bit(NFSD4_CLIENT_CONFIRMED, &clp->cl_flags))
+			rb_erase(&clp->cl_namenode, &nn->conf_name_tree);
+		else
+			rb_erase(&clp->cl_namenode, &nn->unconf_name_tree);
+	}
+	list_del_init(&clp->cl_lru);
+	spin_lock(&clp->cl_lock);
+	list_for_each_entry(ses, &clp->cl_sessions, se_perclnt)
+		list_del_init(&ses->se_hash);
+	spin_unlock(&clp->cl_lock);
+}
+
+static void
+unhash_client(struct nfs4_client *clp)
+{
+	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+
+	spin_lock(&nn->client_lock);
+	unhash_client_locked(clp);
+	spin_unlock(&nn->client_lock);
+}
+
+static __be32 mark_client_expired_locked(struct nfs4_client *clp)
+{
+	if (atomic_read(&clp->cl_rpc_users))
+		return nfserr_jukebox;
+	unhash_client_locked(clp);
+	return nfs_ok;
+}
+
+static void
+__destroy_client(struct nfs4_client *clp)
+{
+	int i;
+	struct nfs4_openowner *oo;
+	struct nfs4_delegation *dp;
+	struct list_head reaplist;
+
+	INIT_LIST_HEAD(&reaplist);
+	spin_lock(&state_lock);
+	while (!list_empty(&clp->cl_delegations)) {
+		dp = list_entry(clp->cl_delegations.next, struct nfs4_delegation, dl_perclnt);
+		WARN_ON(!unhash_delegation_locked(dp));
+		list_add(&dp->dl_recall_lru, &reaplist);
+	}
+	spin_unlock(&state_lock);
+	while (!list_empty(&reaplist)) {
+		dp = list_entry(reaplist.next, struct nfs4_delegation, dl_recall_lru);
+		list_del_init(&dp->dl_recall_lru);
+		destroy_unhashed_deleg(dp);
+	}
+	while (!list_empty(&clp->cl_revoked)) {
+		dp = list_entry(clp->cl_revoked.next, struct nfs4_delegation, dl_recall_lru);
+		list_del_init(&dp->dl_recall_lru);
+		nfs4_put_stid(&dp->dl_stid);
+	}
+	while (!list_empty(&clp->cl_openowners)) {
+		oo = list_entry(clp->cl_openowners.next, struct nfs4_openowner, oo_perclient);
+		nfs4_get_stateowner(&oo->oo_owner);
+		release_openowner(oo);
+	}
+	for (i = 0; i < OWNER_HASH_SIZE; i++) {
+		struct nfs4_stateowner *so, *tmp;
+
+		list_for_each_entry_safe(so, tmp, &clp->cl_ownerstr_hashtbl[i],
+					 so_strhash) {
+			/* Should be no openowners at this point */
+			WARN_ON_ONCE(so->so_is_open_owner);
+			remove_blocked_locks(lockowner(so));
+		}
+	}
+	nfsd4_return_all_client_layouts(clp);
+	nfsd4_shutdown_copy(clp);
+	nfsd4_shutdown_callback(clp);
+	if (clp->cl_cb_conn.cb_xprt)
+		svc_xprt_put(clp->cl_cb_conn.cb_xprt);
+	free_client(clp);
+	wake_up_all(&expiry_wq);
+}
+
+static void
+destroy_client(struct nfs4_client *clp)
+{
+	unhash_client(clp);
+	__destroy_client(clp);
+}
+
+static void inc_reclaim_complete(struct nfs4_client *clp)
+{
+	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+
+	if (!nn->track_reclaim_completes)
+		return;
+	if (!nfsd4_find_reclaim_client(clp->cl_name, nn))
+		return;
+	if (atomic_inc_return(&nn->nr_reclaim_complete) ==
+			nn->reclaim_str_hashtbl_size) {
+		printk(KERN_INFO "NFSD: all clients done reclaiming, ending NFSv4 grace period (net %x)\n",
+				clp->net->ns.inum);
+		nfsd4_end_grace(nn);
+	}
+}
+
+static void expire_client(struct nfs4_client *clp)
+{
+	unhash_client(clp);
+	nfsd4_client_record_remove(clp);
+	__destroy_client(clp);
+}
+
+static void copy_verf(struct nfs4_client *target, nfs4_verifier *source)
+{
+	memcpy(target->cl_verifier.data, source->data,
+			sizeof(target->cl_verifier.data));
+}
+
+static void copy_clid(struct nfs4_client *target, struct nfs4_client *source)
+{
+	target->cl_clientid.cl_boot = source->cl_clientid.cl_boot; 
+	target->cl_clientid.cl_id = source->cl_clientid.cl_id; 
+}
+
+static int copy_cred(struct svc_cred *target, struct svc_cred *source)
+{
+	target->cr_principal = kstrdup(source->cr_principal, GFP_KERNEL);
+	target->cr_raw_principal = kstrdup(source->cr_raw_principal,
+								GFP_KERNEL);
+	target->cr_targ_princ = kstrdup(source->cr_targ_princ, GFP_KERNEL);
+	if ((source->cr_principal && !target->cr_principal) ||
+	    (source->cr_raw_principal && !target->cr_raw_principal) ||
+	    (source->cr_targ_princ && !target->cr_targ_princ))
+		return -ENOMEM;
+
+	target->cr_flavor = source->cr_flavor;
+	target->cr_uid = source->cr_uid;
+	target->cr_gid = source->cr_gid;
+	target->cr_group_info = source->cr_group_info;
+	get_group_info(target->cr_group_info);
+	target->cr_gss_mech = source->cr_gss_mech;
+	if (source->cr_gss_mech)
+		gss_mech_get(source->cr_gss_mech);
+	return 0;
+}
+
+static int
+compare_blob(const struct xdr_netobj *o1, const struct xdr_netobj *o2)
+{
+	if (o1->len < o2->len)
+		return -1;
+	if (o1->len > o2->len)
+		return 1;
+	return memcmp(o1->data, o2->data, o1->len);
+}
+
+static int
+same_verf(nfs4_verifier *v1, nfs4_verifier *v2)
+{
+	return 0 == memcmp(v1->data, v2->data, sizeof(v1->data));
+}
+
+static int
+same_clid(clientid_t *cl1, clientid_t *cl2)
+{
+	return (cl1->cl_boot == cl2->cl_boot) && (cl1->cl_id == cl2->cl_id);
+}
+
+static bool groups_equal(struct group_info *g1, struct group_info *g2)
+{
+	int i;
+
+	if (g1->ngroups != g2->ngroups)
+		return false;
+	for (i=0; i<g1->ngroups; i++)
+		if (!gid_eq(g1->gid[i], g2->gid[i]))
+			return false;
+	return true;
+}
+
+/*
+ * RFC 3530 language requires clid_inuse be returned when the
+ * "principal" associated with a requests differs from that previously
+ * used.  We use uid, gid's, and gss principal string as our best
+ * approximation.  We also don't want to allow non-gss use of a client
+ * established using gss: in theory cr_principal should catch that
+ * change, but in practice cr_principal can be null even in the gss case
+ * since gssd doesn't always pass down a principal string.
+ */
+static bool is_gss_cred(struct svc_cred *cr)
+{
+	/* Is cr_flavor one of the gss "pseudoflavors"?: */
+	return (cr->cr_flavor > RPC_AUTH_MAXFLAVOR);
+}
+
+
+static bool
+same_creds(struct svc_cred *cr1, struct svc_cred *cr2)
+{
+	if ((is_gss_cred(cr1) != is_gss_cred(cr2))
+		|| (!uid_eq(cr1->cr_uid, cr2->cr_uid))
+		|| (!gid_eq(cr1->cr_gid, cr2->cr_gid))
+		|| !groups_equal(cr1->cr_group_info, cr2->cr_group_info))
+		return false;
+	/* XXX: check that cr_targ_princ fields match ? */
+	if (cr1->cr_principal == cr2->cr_principal)
+		return true;
+	if (!cr1->cr_principal || !cr2->cr_principal)
+		return false;
+	return 0 == strcmp(cr1->cr_principal, cr2->cr_principal);
+}
+
+static bool svc_rqst_integrity_protected(struct svc_rqst *rqstp)
+{
+	struct svc_cred *cr = &rqstp->rq_cred;
+	u32 service;
+
+	if (!cr->cr_gss_mech)
+		return false;
+	service = gss_pseudoflavor_to_service(cr->cr_gss_mech, cr->cr_flavor);
+	return service == RPC_GSS_SVC_INTEGRITY ||
+	       service == RPC_GSS_SVC_PRIVACY;
+}
+
+bool nfsd4_mach_creds_match(struct nfs4_client *cl, struct svc_rqst *rqstp)
+{
+	struct svc_cred *cr = &rqstp->rq_cred;
+
+	if (!cl->cl_mach_cred)
+		return true;
+	if (cl->cl_cred.cr_gss_mech != cr->cr_gss_mech)
+		return false;
+	if (!svc_rqst_integrity_protected(rqstp))
+		return false;
+	if (cl->cl_cred.cr_raw_principal)
+		return 0 == strcmp(cl->cl_cred.cr_raw_principal,
+						cr->cr_raw_principal);
+	if (!cr->cr_principal)
+		return false;
+	return 0 == strcmp(cl->cl_cred.cr_principal, cr->cr_principal);
+}
+
+static void gen_confirm(struct nfs4_client *clp, struct nfsd_net *nn)
+{
+	__be32 verf[2];
+
+	/*
+	 * This is opaque to client, so no need to byte-swap. Use
+	 * __force to keep sparse happy
+	 */
+	verf[0] = (__force __be32)(u32)ktime_get_real_seconds();
+	verf[1] = (__force __be32)nn->clverifier_counter++;
+	memcpy(clp->cl_confirm.data, verf, sizeof(clp->cl_confirm.data));
+}
+
+static void gen_clid(struct nfs4_client *clp, struct nfsd_net *nn)
+{
+	clp->cl_clientid.cl_boot = (u32)nn->boot_time;
+	clp->cl_clientid.cl_id = nn->clientid_counter++;
+	gen_confirm(clp, nn);
+}
+
+static struct nfs4_stid *
+find_stateid_locked(struct nfs4_client *cl, stateid_t *t)
+{
+	struct nfs4_stid *ret;
+
+	ret = idr_find(&cl->cl_stateids, t->si_opaque.so_id);
+	if (!ret || !ret->sc_type)
+		return NULL;
+	return ret;
+}
+
+static struct nfs4_stid *
+find_stateid_by_type(struct nfs4_client *cl, stateid_t *t, char typemask)
+{
+	struct nfs4_stid *s;
+
+	spin_lock(&cl->cl_lock);
+	s = find_stateid_locked(cl, t);
+	if (s != NULL) {
+		if (typemask & s->sc_type)
+			refcount_inc(&s->sc_count);
+		else
+			s = NULL;
+	}
+	spin_unlock(&cl->cl_lock);
+	return s;
+}
+
+static struct nfs4_client *get_nfsdfs_clp(struct inode *inode)
+{
+	struct nfsdfs_client *nc;
+	nc = get_nfsdfs_client(inode);
+	if (!nc)
+		return NULL;
+	return container_of(nc, struct nfs4_client, cl_nfsdfs);
+}
+
+static void seq_quote_mem(struct seq_file *m, char *data, int len)
+{
+	seq_printf(m, "\"");
+	seq_escape_mem_ascii(m, data, len);
+	seq_printf(m, "\"");
+}
+
+static int client_info_show(struct seq_file *m, void *v)
+{
+	struct inode *inode = m->private;
+	struct nfs4_client *clp;
+	u64 clid;
+
+	clp = get_nfsdfs_clp(inode);
+	if (!clp)
+		return -ENXIO;
+	memcpy(&clid, &clp->cl_clientid, sizeof(clid));
+	seq_printf(m, "clientid: 0x%llx\n", clid);
+	seq_printf(m, "address: \"%pISpc\"\n", (struct sockaddr *)&clp->cl_addr);
+	seq_printf(m, "name: ");
+	seq_quote_mem(m, clp->cl_name.data, clp->cl_name.len);
+	seq_printf(m, "\nminor version: %d\n", clp->cl_minorversion);
+	if (clp->cl_nii_domain.data) {
+		seq_printf(m, "Implementation domain: ");
+		seq_quote_mem(m, clp->cl_nii_domain.data,
+					clp->cl_nii_domain.len);
+		seq_printf(m, "\nImplementation name: ");
+		seq_quote_mem(m, clp->cl_nii_name.data, clp->cl_nii_name.len);
+		seq_printf(m, "\nImplementation time: [%lld, %ld]\n",
+			clp->cl_nii_time.tv_sec, clp->cl_nii_time.tv_nsec);
+	}
+	drop_client(clp);
+
+	return 0;
+}
+
+static int client_info_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, client_info_show, inode);
+}
+
+static const struct file_operations client_info_fops = {
+	.open		= client_info_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+
+static void *states_start(struct seq_file *s, loff_t *pos)
+	__acquires(&clp->cl_lock)
+{
+	struct nfs4_client *clp = s->private;
+	unsigned long id = *pos;
+	void *ret;
+
+	spin_lock(&clp->cl_lock);
+	ret = idr_get_next_ul(&clp->cl_stateids, &id);
+	*pos = id;
+	return ret;
+}
+
+static void *states_next(struct seq_file *s, void *v, loff_t *pos)
+{
+	struct nfs4_client *clp = s->private;
+	unsigned long id = *pos;
+	void *ret;
+
+	id = *pos;
+	id++;
+	ret = idr_get_next_ul(&clp->cl_stateids, &id);
+	*pos = id;
+	return ret;
+}
+
+static void states_stop(struct seq_file *s, void *v)
+	__releases(&clp->cl_lock)
+{
+	struct nfs4_client *clp = s->private;
+
+	spin_unlock(&clp->cl_lock);
+}
+
+static void nfs4_show_fname(struct seq_file *s, struct nfsd_file *f)
+{
+         seq_printf(s, "filename: \"%pD2\"", f->nf_file);
+}
+
+static void nfs4_show_superblock(struct seq_file *s, struct nfsd_file *f)
+{
+	struct inode *inode = f->nf_inode;
+
+	seq_printf(s, "superblock: \"%02x:%02x:%ld\"",
+					MAJOR(inode->i_sb->s_dev),
+					 MINOR(inode->i_sb->s_dev),
+					 inode->i_ino);
+}
+
+static void nfs4_show_owner(struct seq_file *s, struct nfs4_stateowner *oo)
+{
+	seq_printf(s, "owner: ");
+	seq_quote_mem(s, oo->so_owner.data, oo->so_owner.len);
+}
+
+static void nfs4_show_stateid(struct seq_file *s, stateid_t *stid)
+{
+	seq_printf(s, "0x%.8x", stid->si_generation);
+	seq_printf(s, "%12phN", &stid->si_opaque);
+}
+
+static int nfs4_show_open(struct seq_file *s, struct nfs4_stid *st)
+{
+	struct nfs4_ol_stateid *ols;
+	struct nfs4_file *nf;
+	struct nfsd_file *file;
+	struct nfs4_stateowner *oo;
+	unsigned int access, deny;
+
+	if (st->sc_type != NFS4_OPEN_STID && st->sc_type != NFS4_LOCK_STID)
+		return 0; /* XXX: or SEQ_SKIP? */
+	ols = openlockstateid(st);
+	oo = ols->st_stateowner;
+	nf = st->sc_file;
+
+	spin_lock(&nf->fi_lock);
+	file = find_any_file_locked(nf);
+	if (!file)
+		goto out;
+
+	seq_printf(s, "- ");
+	nfs4_show_stateid(s, &st->sc_stateid);
+	seq_printf(s, ": { type: open, ");
+
+	access = bmap_to_share_mode(ols->st_access_bmap);
+	deny   = bmap_to_share_mode(ols->st_deny_bmap);
+
+	seq_printf(s, "access: %s%s, ",
+		access & NFS4_SHARE_ACCESS_READ ? "r" : "-",
+		access & NFS4_SHARE_ACCESS_WRITE ? "w" : "-");
+	seq_printf(s, "deny: %s%s, ",
+		deny & NFS4_SHARE_ACCESS_READ ? "r" : "-",
+		deny & NFS4_SHARE_ACCESS_WRITE ? "w" : "-");
+
+	nfs4_show_superblock(s, file);
+	seq_printf(s, ", ");
+	nfs4_show_fname(s, file);
+	seq_printf(s, ", ");
+	nfs4_show_owner(s, oo);
+	seq_printf(s, " }\n");
+out:
+	spin_unlock(&nf->fi_lock);
+	return 0;
+}
+
+static int nfs4_show_lock(struct seq_file *s, struct nfs4_stid *st)
+{
+	struct nfs4_ol_stateid *ols;
+	struct nfs4_file *nf;
+	struct nfsd_file *file;
+	struct nfs4_stateowner *oo;
+
+	ols = openlockstateid(st);
+	oo = ols->st_stateowner;
+	nf = st->sc_file;
+	spin_lock(&nf->fi_lock);
+	file = find_any_file_locked(nf);
+	if (!file)
+		goto out;
+
+	seq_printf(s, "- ");
+	nfs4_show_stateid(s, &st->sc_stateid);
+	seq_printf(s, ": { type: lock, ");
+
+	/*
+	 * Note: a lock stateid isn't really the same thing as a lock,
+	 * it's the locking state held by one owner on a file, and there
+	 * may be multiple (or no) lock ranges associated with it.
+	 * (Same for the matter is true of open stateids.)
+	 */
+
+	nfs4_show_superblock(s, file);
+	/* XXX: open stateid? */
+	seq_printf(s, ", ");
+	nfs4_show_fname(s, file);
+	seq_printf(s, ", ");
+	nfs4_show_owner(s, oo);
+	seq_printf(s, " }\n");
+out:
+	spin_unlock(&nf->fi_lock);
+	return 0;
+}
+
+static int nfs4_show_deleg(struct seq_file *s, struct nfs4_stid *st)
+{
+	struct nfs4_delegation *ds;
+	struct nfs4_file *nf;
+	struct nfsd_file *file;
+
+	ds = delegstateid(st);
+	nf = st->sc_file;
+	spin_lock(&nf->fi_lock);
+	file = find_deleg_file_locked(nf);
+	if (!file)
+		goto out;
+
+	seq_printf(s, "- ");
+	nfs4_show_stateid(s, &st->sc_stateid);
+	seq_printf(s, ": { type: deleg, ");
+
+	/* Kinda dead code as long as we only support read delegs: */
+	seq_printf(s, "access: %s, ",
+		ds->dl_type == NFS4_OPEN_DELEGATE_READ ? "r" : "w");
+
+	/* XXX: lease time, whether it's being recalled. */
+
+	nfs4_show_superblock(s, file);
+	seq_printf(s, ", ");
+	nfs4_show_fname(s, file);
+	seq_printf(s, " }\n");
+out:
+	spin_unlock(&nf->fi_lock);
+	return 0;
+}
+
+static int nfs4_show_layout(struct seq_file *s, struct nfs4_stid *st)
+{
+	struct nfs4_layout_stateid *ls;
+	struct nfsd_file *file;
+
+	ls = container_of(st, struct nfs4_layout_stateid, ls_stid);
+	file = ls->ls_file;
+
+	seq_printf(s, "- ");
+	nfs4_show_stateid(s, &st->sc_stateid);
+	seq_printf(s, ": { type: layout, ");
+
+	/* XXX: What else would be useful? */
+
+	nfs4_show_superblock(s, file);
+	seq_printf(s, ", ");
+	nfs4_show_fname(s, file);
+	seq_printf(s, " }\n");
+
+	return 0;
+}
+
+static int states_show(struct seq_file *s, void *v)
+{
+	struct nfs4_stid *st = v;
+
+	switch (st->sc_type) {
+	case NFS4_OPEN_STID:
+		return nfs4_show_open(s, st);
+	case NFS4_LOCK_STID:
+		return nfs4_show_lock(s, st);
+	case NFS4_DELEG_STID:
+		return nfs4_show_deleg(s, st);
+	case NFS4_LAYOUT_STID:
+		return nfs4_show_layout(s, st);
+	default:
+		return 0; /* XXX: or SEQ_SKIP? */
+	}
+	/* XXX: copy stateids? */
+}
+
+static struct seq_operations states_seq_ops = {
+	.start = states_start,
+	.next = states_next,
+	.stop = states_stop,
+	.show = states_show
+};
+
+static int client_states_open(struct inode *inode, struct file *file)
+{
+	struct seq_file *s;
+	struct nfs4_client *clp;
+	int ret;
+
+	clp = get_nfsdfs_clp(inode);
+	if (!clp)
+		return -ENXIO;
+
+	ret = seq_open(file, &states_seq_ops);
+	if (ret)
+		return ret;
+	s = file->private_data;
+	s->private = clp;
+	return 0;
+}
+
+static int client_opens_release(struct inode *inode, struct file *file)
+{
+	struct seq_file *m = file->private_data;
+	struct nfs4_client *clp = m->private;
+
+	/* XXX: alternatively, we could get/drop in seq start/stop */
+	drop_client(clp);
+	return seq_release(inode, file);
+}
+
+static const struct file_operations client_states_fops = {
+	.open		= client_states_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= client_opens_release,
+};
+
+/*
+ * Normally we refuse to destroy clients that are in use, but here the
+ * administrator is telling us to just do it.  We also want to wait
+ * so the caller has a guarantee that the client's locks are gone by
+ * the time the write returns:
+ */
+static void force_expire_client(struct nfs4_client *clp)
+{
+	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+	bool already_expired;
+
+	spin_lock(&nn->client_lock);
+	clp->cl_time = 0;
+	spin_unlock(&nn->client_lock);
+
+	wait_event(expiry_wq, atomic_read(&clp->cl_rpc_users) == 0);
+	spin_lock(&nn->client_lock);
+	already_expired = list_empty(&clp->cl_lru);
+	if (!already_expired)
+		unhash_client_locked(clp);
+	spin_unlock(&nn->client_lock);
+
+	if (!already_expired)
+		expire_client(clp);
+	else
+		wait_event(expiry_wq, clp->cl_nfsd_dentry == NULL);
+}
+
+static ssize_t client_ctl_write(struct file *file, const char __user *buf,
+				   size_t size, loff_t *pos)
+{
+	char *data;
+	struct nfs4_client *clp;
+
+	data = simple_transaction_get(file, buf, size);
+	if (IS_ERR(data))
+		return PTR_ERR(data);
+	if (size != 7 || 0 != memcmp(data, "expire\n", 7))
+		return -EINVAL;
+	clp = get_nfsdfs_clp(file_inode(file));
+	if (!clp)
+		return -ENXIO;
+	force_expire_client(clp);
+	drop_client(clp);
+	return 7;
+}
+
+static const struct file_operations client_ctl_fops = {
+	.write		= client_ctl_write,
+	.release	= simple_transaction_release,
+};
+
+static const struct tree_descr client_files[] = {
+	[0] = {"info", &client_info_fops, S_IRUSR},
+	[1] = {"states", &client_states_fops, S_IRUSR},
+	[2] = {"ctl", &client_ctl_fops, S_IWUSR},
+	[3] = {""},
+};
+
+static struct nfs4_client *create_client(struct xdr_netobj name,
+		struct svc_rqst *rqstp, nfs4_verifier *verf)
+{
+	struct nfs4_client *clp;
+	struct sockaddr *sa = svc_addr(rqstp);
+	int ret;
+	struct net *net = SVC_NET(rqstp);
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	clp = alloc_client(name);
+	if (clp == NULL)
+		return NULL;
+
+	ret = copy_cred(&clp->cl_cred, &rqstp->rq_cred);
+	if (ret) {
+		free_client(clp);
+		return NULL;
+	}
+	gen_clid(clp, nn);
+	kref_init(&clp->cl_nfsdfs.cl_ref);
+	nfsd4_init_cb(&clp->cl_cb_null, clp, NULL, NFSPROC4_CLNT_CB_NULL);
+	clp->cl_time = ktime_get_boottime_seconds();
+	clear_bit(0, &clp->cl_cb_slot_busy);
+	copy_verf(clp, verf);
+	memcpy(&clp->cl_addr, sa, sizeof(struct sockaddr_storage));
+	clp->cl_cb_session = NULL;
+	clp->net = net;
+	clp->cl_nfsd_dentry = nfsd_client_mkdir(nn, &clp->cl_nfsdfs,
+			clp->cl_clientid.cl_id - nn->clientid_base,
+			client_files);
+	if (!clp->cl_nfsd_dentry) {
+		free_client(clp);
+		return NULL;
+	}
+	return clp;
+}
+
+static void
+add_clp_to_name_tree(struct nfs4_client *new_clp, struct rb_root *root)
+{
+	struct rb_node **new = &(root->rb_node), *parent = NULL;
+	struct nfs4_client *clp;
+
+	while (*new) {
+		clp = rb_entry(*new, struct nfs4_client, cl_namenode);
+		parent = *new;
+
+		if (compare_blob(&clp->cl_name, &new_clp->cl_name) > 0)
+			new = &((*new)->rb_left);
+		else
+			new = &((*new)->rb_right);
+	}
+
+	rb_link_node(&new_clp->cl_namenode, parent, new);
+	rb_insert_color(&new_clp->cl_namenode, root);
+}
+
+static struct nfs4_client *
+find_clp_in_name_tree(struct xdr_netobj *name, struct rb_root *root)
+{
+	int cmp;
+	struct rb_node *node = root->rb_node;
+	struct nfs4_client *clp;
+
+	while (node) {
+		clp = rb_entry(node, struct nfs4_client, cl_namenode);
+		cmp = compare_blob(&clp->cl_name, name);
+		if (cmp > 0)
+			node = node->rb_left;
+		else if (cmp < 0)
+			node = node->rb_right;
+		else
+			return clp;
+	}
+	return NULL;
+}
+
+static void
+add_to_unconfirmed(struct nfs4_client *clp)
+{
+	unsigned int idhashval;
+	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+
+	lockdep_assert_held(&nn->client_lock);
+
+	clear_bit(NFSD4_CLIENT_CONFIRMED, &clp->cl_flags);
+	add_clp_to_name_tree(clp, &nn->unconf_name_tree);
+	idhashval = clientid_hashval(clp->cl_clientid.cl_id);
+	list_add(&clp->cl_idhash, &nn->unconf_id_hashtbl[idhashval]);
+	renew_client_locked(clp);
+}
+
+static void
+move_to_confirmed(struct nfs4_client *clp)
+{
+	unsigned int idhashval = clientid_hashval(clp->cl_clientid.cl_id);
+	struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+
+	lockdep_assert_held(&nn->client_lock);
+
+	dprintk("NFSD: move_to_confirm nfs4_client %p\n", clp);
+	list_move(&clp->cl_idhash, &nn->conf_id_hashtbl[idhashval]);
+	rb_erase(&clp->cl_namenode, &nn->unconf_name_tree);
+	add_clp_to_name_tree(clp, &nn->conf_name_tree);
+	set_bit(NFSD4_CLIENT_CONFIRMED, &clp->cl_flags);
+	renew_client_locked(clp);
+}
+
+static struct nfs4_client *
+find_client_in_id_table(struct list_head *tbl, clientid_t *clid, bool sessions)
+{
+	struct nfs4_client *clp;
+	unsigned int idhashval = clientid_hashval(clid->cl_id);
+
+	list_for_each_entry(clp, &tbl[idhashval], cl_idhash) {
+		if (same_clid(&clp->cl_clientid, clid)) {
+			if ((bool)clp->cl_minorversion != sessions)
+				return NULL;
+			renew_client_locked(clp);
+			return clp;
+		}
+	}
+	return NULL;
+}
+
+static struct nfs4_client *
+find_confirmed_client(clientid_t *clid, bool sessions, struct nfsd_net *nn)
+{
+	struct list_head *tbl = nn->conf_id_hashtbl;
+
+	lockdep_assert_held(&nn->client_lock);
+	return find_client_in_id_table(tbl, clid, sessions);
+}
+
+static struct nfs4_client *
+find_unconfirmed_client(clientid_t *clid, bool sessions, struct nfsd_net *nn)
+{
+	struct list_head *tbl = nn->unconf_id_hashtbl;
+
+	lockdep_assert_held(&nn->client_lock);
+	return find_client_in_id_table(tbl, clid, sessions);
+}
+
+static bool clp_used_exchangeid(struct nfs4_client *clp)
+{
+	return clp->cl_exchange_flags != 0;
+} 
+
+static struct nfs4_client *
+find_confirmed_client_by_name(struct xdr_netobj *name, struct nfsd_net *nn)
+{
+	lockdep_assert_held(&nn->client_lock);
+	return find_clp_in_name_tree(name, &nn->conf_name_tree);
+}
+
+static struct nfs4_client *
+find_unconfirmed_client_by_name(struct xdr_netobj *name, struct nfsd_net *nn)
+{
+	lockdep_assert_held(&nn->client_lock);
+	return find_clp_in_name_tree(name, &nn->unconf_name_tree);
+}
+
+static void
+gen_callback(struct nfs4_client *clp, struct nfsd4_setclientid *se, struct svc_rqst *rqstp)
+{
+	struct nfs4_cb_conn *conn = &clp->cl_cb_conn;
+	struct sockaddr	*sa = svc_addr(rqstp);
+	u32 scopeid = rpc_get_scope_id(sa);
+	unsigned short expected_family;
+
+	/* Currently, we only support tcp and tcp6 for the callback channel */
+	if (se->se_callback_netid_len == 3 &&
+	    !memcmp(se->se_callback_netid_val, "tcp", 3))
+		expected_family = AF_INET;
+	else if (se->se_callback_netid_len == 4 &&
+		 !memcmp(se->se_callback_netid_val, "tcp6", 4))
+		expected_family = AF_INET6;
+	else
+		goto out_err;
+
+	conn->cb_addrlen = rpc_uaddr2sockaddr(clp->net, se->se_callback_addr_val,
+					    se->se_callback_addr_len,
+					    (struct sockaddr *)&conn->cb_addr,
+					    sizeof(conn->cb_addr));
+
+	if (!conn->cb_addrlen || conn->cb_addr.ss_family != expected_family)
+		goto out_err;
+
+	if (conn->cb_addr.ss_family == AF_INET6)
+		((struct sockaddr_in6 *)&conn->cb_addr)->sin6_scope_id = scopeid;
+
+	conn->cb_prog = se->se_callback_prog;
+	conn->cb_ident = se->se_callback_ident;
+	memcpy(&conn->cb_saddr, &rqstp->rq_daddr, rqstp->rq_daddrlen);
+	trace_nfsd_cb_args(clp, conn);
+	return;
+out_err:
+	conn->cb_addr.ss_family = AF_UNSPEC;
+	conn->cb_addrlen = 0;
+	trace_nfsd_cb_nodelegs(clp);
+	return;
+}
+
+/*
+ * Cache a reply. nfsd4_check_resp_size() has bounded the cache size.
+ */
+static void
+nfsd4_store_cache_entry(struct nfsd4_compoundres *resp)
+{
+	struct xdr_buf *buf = resp->xdr.buf;
+	struct nfsd4_slot *slot = resp->cstate.slot;
+	unsigned int base;
+
+	dprintk("--> %s slot %p\n", __func__, slot);
+
+	slot->sl_flags |= NFSD4_SLOT_INITIALIZED;
+	slot->sl_opcnt = resp->opcnt;
+	slot->sl_status = resp->cstate.status;
+	free_svc_cred(&slot->sl_cred);
+	copy_cred(&slot->sl_cred, &resp->rqstp->rq_cred);
+
+	if (!nfsd4_cache_this(resp)) {
+		slot->sl_flags &= ~NFSD4_SLOT_CACHED;
+		return;
+	}
+	slot->sl_flags |= NFSD4_SLOT_CACHED;
+
+	base = resp->cstate.data_offset;
+	slot->sl_datalen = buf->len - base;
+	if (read_bytes_from_xdr_buf(buf, base, slot->sl_data, slot->sl_datalen))
+		WARN(1, "%s: sessions DRC could not cache compound\n",
+		     __func__);
+	return;
+}
+
+/*
+ * Encode the replay sequence operation from the slot values.
+ * If cachethis is FALSE encode the uncached rep error on the next
+ * operation which sets resp->p and increments resp->opcnt for
+ * nfs4svc_encode_compoundres.
+ *
+ */
+static __be32
+nfsd4_enc_sequence_replay(struct nfsd4_compoundargs *args,
+			  struct nfsd4_compoundres *resp)
+{
+	struct nfsd4_op *op;
+	struct nfsd4_slot *slot = resp->cstate.slot;
+
+	/* Encode the replayed sequence operation */
+	op = &args->ops[resp->opcnt - 1];
+	nfsd4_encode_operation(resp, op);
+
+	if (slot->sl_flags & NFSD4_SLOT_CACHED)
+		return op->status;
+	if (args->opcnt == 1) {
+		/*
+		 * The original operation wasn't a solo sequence--we
+		 * always cache those--so this retry must not match the
+		 * original:
+		 */
+		op->status = nfserr_seq_false_retry;
+	} else {
+		op = &args->ops[resp->opcnt++];
+		op->status = nfserr_retry_uncached_rep;
+		nfsd4_encode_operation(resp, op);
+	}
+	return op->status;
+}
+
+/*
+ * The sequence operation is not cached because we can use the slot and
+ * session values.
+ */
+static __be32
+nfsd4_replay_cache_entry(struct nfsd4_compoundres *resp,
+			 struct nfsd4_sequence *seq)
+{
+	struct nfsd4_slot *slot = resp->cstate.slot;
+	struct xdr_stream *xdr = &resp->xdr;
+	__be32 *p;
+	__be32 status;
+
+	dprintk("--> %s slot %p\n", __func__, slot);
+
+	status = nfsd4_enc_sequence_replay(resp->rqstp->rq_argp, resp);
+	if (status)
+		return status;
+
+	p = xdr_reserve_space(xdr, slot->sl_datalen);
+	if (!p) {
+		WARN_ON_ONCE(1);
+		return nfserr_serverfault;
+	}
+	xdr_encode_opaque_fixed(p, slot->sl_data, slot->sl_datalen);
+	xdr_commit_encode(xdr);
+
+	resp->opcnt = slot->sl_opcnt;
+	return slot->sl_status;
+}
+
+/*
+ * Set the exchange_id flags returned by the server.
+ */
+static void
+nfsd4_set_ex_flags(struct nfs4_client *new, struct nfsd4_exchange_id *clid)
+{
+#ifdef CONFIG_NFSD_PNFS
+	new->cl_exchange_flags |= EXCHGID4_FLAG_USE_PNFS_MDS;
+#else
+	new->cl_exchange_flags |= EXCHGID4_FLAG_USE_NON_PNFS;
+#endif
+
+	/* Referrals are supported, Migration is not. */
+	new->cl_exchange_flags |= EXCHGID4_FLAG_SUPP_MOVED_REFER;
+
+	/* set the wire flags to return to client. */
+	clid->flags = new->cl_exchange_flags;
+}
+
+static bool client_has_openowners(struct nfs4_client *clp)
+{
+	struct nfs4_openowner *oo;
+
+	list_for_each_entry(oo, &clp->cl_openowners, oo_perclient) {
+		if (!list_empty(&oo->oo_owner.so_stateids))
+			return true;
+	}
+	return false;
+}
+
+static bool client_has_state(struct nfs4_client *clp)
+{
+	return client_has_openowners(clp)
+#ifdef CONFIG_NFSD_PNFS
+		|| !list_empty(&clp->cl_lo_states)
+#endif
+		|| !list_empty(&clp->cl_delegations)
+		|| !list_empty(&clp->cl_sessions)
+		|| !list_empty(&clp->async_copies);
+}
+
+static __be32 copy_impl_id(struct nfs4_client *clp,
+				struct nfsd4_exchange_id *exid)
+{
+	if (!exid->nii_domain.data)
+		return 0;
+	xdr_netobj_dup(&clp->cl_nii_domain, &exid->nii_domain, GFP_KERNEL);
+	if (!clp->cl_nii_domain.data)
+		return nfserr_jukebox;
+	xdr_netobj_dup(&clp->cl_nii_name, &exid->nii_name, GFP_KERNEL);
+	if (!clp->cl_nii_name.data)
+		return nfserr_jukebox;
+	clp->cl_nii_time = exid->nii_time;
+	return 0;
+}
+
+__be32
+nfsd4_exchange_id(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+		union nfsd4_op_u *u)
+{
+	struct nfsd4_exchange_id *exid = &u->exchange_id;
+	struct nfs4_client *conf, *new;
+	struct nfs4_client *unconf = NULL;
+	__be32 status;
+	char			addr_str[INET6_ADDRSTRLEN];
+	nfs4_verifier		verf = exid->verifier;
+	struct sockaddr		*sa = svc_addr(rqstp);
+	bool	update = exid->flags & EXCHGID4_FLAG_UPD_CONFIRMED_REC_A;
+	struct nfsd_net		*nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+
+	rpc_ntop(sa, addr_str, sizeof(addr_str));
+	dprintk("%s rqstp=%p exid=%p clname.len=%u clname.data=%p "
+		"ip_addr=%s flags %x, spa_how %d\n",
+		__func__, rqstp, exid, exid->clname.len, exid->clname.data,
+		addr_str, exid->flags, exid->spa_how);
+
+	if (exid->flags & ~EXCHGID4_FLAG_MASK_A)
+		return nfserr_inval;
+
+	new = create_client(exid->clname, rqstp, &verf);
+	if (new == NULL)
+		return nfserr_jukebox;
+	status = copy_impl_id(new, exid);
+	if (status)
+		goto out_nolock;
+
+	switch (exid->spa_how) {
+	case SP4_MACH_CRED:
+		exid->spo_must_enforce[0] = 0;
+		exid->spo_must_enforce[1] = (
+			1 << (OP_BIND_CONN_TO_SESSION - 32) |
+			1 << (OP_EXCHANGE_ID - 32) |
+			1 << (OP_CREATE_SESSION - 32) |
+			1 << (OP_DESTROY_SESSION - 32) |
+			1 << (OP_DESTROY_CLIENTID - 32));
+
+		exid->spo_must_allow[0] &= (1 << (OP_CLOSE) |
+					1 << (OP_OPEN_DOWNGRADE) |
+					1 << (OP_LOCKU) |
+					1 << (OP_DELEGRETURN));
+
+		exid->spo_must_allow[1] &= (
+					1 << (OP_TEST_STATEID - 32) |
+					1 << (OP_FREE_STATEID - 32));
+		if (!svc_rqst_integrity_protected(rqstp)) {
+			status = nfserr_inval;
+			goto out_nolock;
+		}
+		/*
+		 * Sometimes userspace doesn't give us a principal.
+		 * Which is a bug, really.  Anyway, we can't enforce
+		 * MACH_CRED in that case, better to give up now:
+		 */
+		if (!new->cl_cred.cr_principal &&
+					!new->cl_cred.cr_raw_principal) {
+			status = nfserr_serverfault;
+			goto out_nolock;
+		}
+		new->cl_mach_cred = true;
+	case SP4_NONE:
+		break;
+	default:				/* checked by xdr code */
+		WARN_ON_ONCE(1);
+		fallthrough;
+	case SP4_SSV:
+		status = nfserr_encr_alg_unsupp;
+		goto out_nolock;
+	}
+
+	/* Cases below refer to rfc 5661 section 18.35.4: */
+	spin_lock(&nn->client_lock);
+	conf = find_confirmed_client_by_name(&exid->clname, nn);
+	if (conf) {
+		bool creds_match = same_creds(&conf->cl_cred, &rqstp->rq_cred);
+		bool verfs_match = same_verf(&verf, &conf->cl_verifier);
+
+		if (update) {
+			if (!clp_used_exchangeid(conf)) { /* buggy client */
+				status = nfserr_inval;
+				goto out;
+			}
+			if (!nfsd4_mach_creds_match(conf, rqstp)) {
+				status = nfserr_wrong_cred;
+				goto out;
+			}
+			if (!creds_match) { /* case 9 */
+				status = nfserr_perm;
+				goto out;
+			}
+			if (!verfs_match) { /* case 8 */
+				status = nfserr_not_same;
+				goto out;
+			}
+			/* case 6 */
+			exid->flags |= EXCHGID4_FLAG_CONFIRMED_R;
+			goto out_copy;
+		}
+		if (!creds_match) { /* case 3 */
+			if (client_has_state(conf)) {
+				status = nfserr_clid_inuse;
+				goto out;
+			}
+			goto out_new;
+		}
+		if (verfs_match) { /* case 2 */
+			conf->cl_exchange_flags |= EXCHGID4_FLAG_CONFIRMED_R;
+			goto out_copy;
+		}
+		/* case 5, client reboot */
+		conf = NULL;
+		goto out_new;
+	}
+
+	if (update) { /* case 7 */
+		status = nfserr_noent;
+		goto out;
+	}
+
+	unconf  = find_unconfirmed_client_by_name(&exid->clname, nn);
+	if (unconf) /* case 4, possible retry or client restart */
+		unhash_client_locked(unconf);
+
+	/* case 1 (normal case) */
+out_new:
+	if (conf) {
+		status = mark_client_expired_locked(conf);
+		if (status)
+			goto out;
+	}
+	new->cl_minorversion = cstate->minorversion;
+	new->cl_spo_must_allow.u.words[0] = exid->spo_must_allow[0];
+	new->cl_spo_must_allow.u.words[1] = exid->spo_must_allow[1];
+
+	add_to_unconfirmed(new);
+	swap(new, conf);
+out_copy:
+	exid->clientid.cl_boot = conf->cl_clientid.cl_boot;
+	exid->clientid.cl_id = conf->cl_clientid.cl_id;
+
+	exid->seqid = conf->cl_cs_slot.sl_seqid + 1;
+	nfsd4_set_ex_flags(conf, exid);
+
+	dprintk("nfsd4_exchange_id seqid %d flags %x\n",
+		conf->cl_cs_slot.sl_seqid, conf->cl_exchange_flags);
+	status = nfs_ok;
+
+out:
+	spin_unlock(&nn->client_lock);
+out_nolock:
+	if (new)
+		expire_client(new);
+	if (unconf)
+		expire_client(unconf);
+	return status;
+}
+
+static __be32
+check_slot_seqid(u32 seqid, u32 slot_seqid, int slot_inuse)
+{
+	dprintk("%s enter. seqid %d slot_seqid %d\n", __func__, seqid,
+		slot_seqid);
+
+	/* The slot is in use, and no response has been sent. */
+	if (slot_inuse) {
+		if (seqid == slot_seqid)
+			return nfserr_jukebox;
+		else
+			return nfserr_seq_misordered;
+	}
+	/* Note unsigned 32-bit arithmetic handles wraparound: */
+	if (likely(seqid == slot_seqid + 1))
+		return nfs_ok;
+	if (seqid == slot_seqid)
+		return nfserr_replay_cache;
+	return nfserr_seq_misordered;
+}
+
+/*
+ * Cache the create session result into the create session single DRC
+ * slot cache by saving the xdr structure. sl_seqid has been set.
+ * Do this for solo or embedded create session operations.
+ */
+static void
+nfsd4_cache_create_session(struct nfsd4_create_session *cr_ses,
+			   struct nfsd4_clid_slot *slot, __be32 nfserr)
+{
+	slot->sl_status = nfserr;
+	memcpy(&slot->sl_cr_ses, cr_ses, sizeof(*cr_ses));
+}
+
+static __be32
+nfsd4_replay_create_session(struct nfsd4_create_session *cr_ses,
+			    struct nfsd4_clid_slot *slot)
+{
+	memcpy(cr_ses, &slot->sl_cr_ses, sizeof(*cr_ses));
+	return slot->sl_status;
+}
+
+#define NFSD_MIN_REQ_HDR_SEQ_SZ	((\
+			2 * 2 + /* credential,verifier: AUTH_NULL, length 0 */ \
+			1 +	/* MIN tag is length with zero, only length */ \
+			3 +	/* version, opcount, opcode */ \
+			XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN) + \
+				/* seqid, slotID, slotID, cache */ \
+			4 ) * sizeof(__be32))
+
+#define NFSD_MIN_RESP_HDR_SEQ_SZ ((\
+			2 +	/* verifier: AUTH_NULL, length 0 */\
+			1 +	/* status */ \
+			1 +	/* MIN tag is length with zero, only length */ \
+			3 +	/* opcount, opcode, opstatus*/ \
+			XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN) + \
+				/* seqid, slotID, slotID, slotID, status */ \
+			5 ) * sizeof(__be32))
+
+static __be32 check_forechannel_attrs(struct nfsd4_channel_attrs *ca, struct nfsd_net *nn)
+{
+	u32 maxrpc = nn->nfsd_serv->sv_max_mesg;
+
+	if (ca->maxreq_sz < NFSD_MIN_REQ_HDR_SEQ_SZ)
+		return nfserr_toosmall;
+	if (ca->maxresp_sz < NFSD_MIN_RESP_HDR_SEQ_SZ)
+		return nfserr_toosmall;
+	ca->headerpadsz = 0;
+	ca->maxreq_sz = min_t(u32, ca->maxreq_sz, maxrpc);
+	ca->maxresp_sz = min_t(u32, ca->maxresp_sz, maxrpc);
+	ca->maxops = min_t(u32, ca->maxops, NFSD_MAX_OPS_PER_COMPOUND);
+	ca->maxresp_cached = min_t(u32, ca->maxresp_cached,
+			NFSD_SLOT_CACHE_SIZE + NFSD_MIN_HDR_SEQ_SZ);
+	ca->maxreqs = min_t(u32, ca->maxreqs, NFSD_MAX_SLOTS_PER_SESSION);
+	/*
+	 * Note decreasing slot size below client's request may make it
+	 * difficult for client to function correctly, whereas
+	 * decreasing the number of slots will (just?) affect
+	 * performance.  When short on memory we therefore prefer to
+	 * decrease number of slots instead of their size.  Clients that
+	 * request larger slots than they need will get poor results:
+	 * Note that we always allow at least one slot, because our
+	 * accounting is soft and provides no guarantees either way.
+	 */
+	ca->maxreqs = nfsd4_get_drc_mem(ca, nn);
+
+	return nfs_ok;
+}
+
+/*
+ * Server's NFSv4.1 backchannel support is AUTH_SYS-only for now.
+ * These are based on similar macros in linux/sunrpc/msg_prot.h .
+ */
+#define RPC_MAX_HEADER_WITH_AUTH_SYS \
+	(RPC_CALLHDRSIZE + 2 * (2 + UNX_CALLSLACK))
+
+#define RPC_MAX_REPHEADER_WITH_AUTH_SYS \
+	(RPC_REPHDRSIZE + (2 + NUL_REPLYSLACK))
+
+#define NFSD_CB_MAX_REQ_SZ	((NFS4_enc_cb_recall_sz + \
+				 RPC_MAX_HEADER_WITH_AUTH_SYS) * sizeof(__be32))
+#define NFSD_CB_MAX_RESP_SZ	((NFS4_dec_cb_recall_sz + \
+				 RPC_MAX_REPHEADER_WITH_AUTH_SYS) * \
+				 sizeof(__be32))
+
+static __be32 check_backchannel_attrs(struct nfsd4_channel_attrs *ca)
+{
+	ca->headerpadsz = 0;
+
+	if (ca->maxreq_sz < NFSD_CB_MAX_REQ_SZ)
+		return nfserr_toosmall;
+	if (ca->maxresp_sz < NFSD_CB_MAX_RESP_SZ)
+		return nfserr_toosmall;
+	ca->maxresp_cached = 0;
+	if (ca->maxops < 2)
+		return nfserr_toosmall;
+
+	return nfs_ok;
+}
+
+static __be32 nfsd4_check_cb_sec(struct nfsd4_cb_sec *cbs)
+{
+	switch (cbs->flavor) {
+	case RPC_AUTH_NULL:
+	case RPC_AUTH_UNIX:
+		return nfs_ok;
+	default:
+		/*
+		 * GSS case: the spec doesn't allow us to return this
+		 * error.  But it also doesn't allow us not to support
+		 * GSS.
+		 * I'd rather this fail hard than return some error the
+		 * client might think it can already handle:
+		 */
+		return nfserr_encr_alg_unsupp;
+	}
+}
+
+__be32
+nfsd4_create_session(struct svc_rqst *rqstp,
+		struct nfsd4_compound_state *cstate, union nfsd4_op_u *u)
+{
+	struct nfsd4_create_session *cr_ses = &u->create_session;
+	struct sockaddr *sa = svc_addr(rqstp);
+	struct nfs4_client *conf, *unconf;
+	struct nfs4_client *old = NULL;
+	struct nfsd4_session *new;
+	struct nfsd4_conn *conn;
+	struct nfsd4_clid_slot *cs_slot = NULL;
+	__be32 status = 0;
+	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+
+	if (cr_ses->flags & ~SESSION4_FLAG_MASK_A)
+		return nfserr_inval;
+	status = nfsd4_check_cb_sec(&cr_ses->cb_sec);
+	if (status)
+		return status;
+	status = check_forechannel_attrs(&cr_ses->fore_channel, nn);
+	if (status)
+		return status;
+	status = check_backchannel_attrs(&cr_ses->back_channel);
+	if (status)
+		goto out_release_drc_mem;
+	status = nfserr_jukebox;
+	new = alloc_session(&cr_ses->fore_channel, &cr_ses->back_channel);
+	if (!new)
+		goto out_release_drc_mem;
+	conn = alloc_conn_from_crses(rqstp, cr_ses);
+	if (!conn)
+		goto out_free_session;
+
+	spin_lock(&nn->client_lock);
+	unconf = find_unconfirmed_client(&cr_ses->clientid, true, nn);
+	conf = find_confirmed_client(&cr_ses->clientid, true, nn);
+	WARN_ON_ONCE(conf && unconf);
+
+	if (conf) {
+		status = nfserr_wrong_cred;
+		if (!nfsd4_mach_creds_match(conf, rqstp))
+			goto out_free_conn;
+		cs_slot = &conf->cl_cs_slot;
+		status = check_slot_seqid(cr_ses->seqid, cs_slot->sl_seqid, 0);
+		if (status) {
+			if (status == nfserr_replay_cache)
+				status = nfsd4_replay_create_session(cr_ses, cs_slot);
+			goto out_free_conn;
+		}
+	} else if (unconf) {
+		if (!same_creds(&unconf->cl_cred, &rqstp->rq_cred) ||
+		    !rpc_cmp_addr(sa, (struct sockaddr *) &unconf->cl_addr)) {
+			status = nfserr_clid_inuse;
+			goto out_free_conn;
+		}
+		status = nfserr_wrong_cred;
+		if (!nfsd4_mach_creds_match(unconf, rqstp))
+			goto out_free_conn;
+		cs_slot = &unconf->cl_cs_slot;
+		status = check_slot_seqid(cr_ses->seqid, cs_slot->sl_seqid, 0);
+		if (status) {
+			/* an unconfirmed replay returns misordered */
+			status = nfserr_seq_misordered;
+			goto out_free_conn;
+		}
+		old = find_confirmed_client_by_name(&unconf->cl_name, nn);
+		if (old) {
+			status = mark_client_expired_locked(old);
+			if (status) {
+				old = NULL;
+				goto out_free_conn;
+			}
+		}
+		move_to_confirmed(unconf);
+		conf = unconf;
+	} else {
+		status = nfserr_stale_clientid;
+		goto out_free_conn;
+	}
+	status = nfs_ok;
+	/* Persistent sessions are not supported */
+	cr_ses->flags &= ~SESSION4_PERSIST;
+	/* Upshifting from TCP to RDMA is not supported */
+	cr_ses->flags &= ~SESSION4_RDMA;
+
+	init_session(rqstp, new, conf, cr_ses);
+	nfsd4_get_session_locked(new);
+
+	memcpy(cr_ses->sessionid.data, new->se_sessionid.data,
+	       NFS4_MAX_SESSIONID_LEN);
+	cs_slot->sl_seqid++;
+	cr_ses->seqid = cs_slot->sl_seqid;
+
+	/* cache solo and embedded create sessions under the client_lock */
+	nfsd4_cache_create_session(cr_ses, cs_slot, status);
+	spin_unlock(&nn->client_lock);
+	/* init connection and backchannel */
+	nfsd4_init_conn(rqstp, conn, new);
+	nfsd4_put_session(new);
+	if (old)
+		expire_client(old);
+	return status;
+out_free_conn:
+	spin_unlock(&nn->client_lock);
+	free_conn(conn);
+	if (old)
+		expire_client(old);
+out_free_session:
+	__free_session(new);
+out_release_drc_mem:
+	nfsd4_put_drc_mem(&cr_ses->fore_channel);
+	return status;
+}
+
+static __be32 nfsd4_map_bcts_dir(u32 *dir)
+{
+	switch (*dir) {
+	case NFS4_CDFC4_FORE:
+	case NFS4_CDFC4_BACK:
+		return nfs_ok;
+	case NFS4_CDFC4_FORE_OR_BOTH:
+	case NFS4_CDFC4_BACK_OR_BOTH:
+		*dir = NFS4_CDFC4_BOTH;
+		return nfs_ok;
+	}
+	return nfserr_inval;
+}
+
+__be32 nfsd4_backchannel_ctl(struct svc_rqst *rqstp,
+		struct nfsd4_compound_state *cstate,
+		union nfsd4_op_u *u)
+{
+	struct nfsd4_backchannel_ctl *bc = &u->backchannel_ctl;
+	struct nfsd4_session *session = cstate->session;
+	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+	__be32 status;
+
+	status = nfsd4_check_cb_sec(&bc->bc_cb_sec);
+	if (status)
+		return status;
+	spin_lock(&nn->client_lock);
+	session->se_cb_prog = bc->bc_cb_program;
+	session->se_cb_sec = bc->bc_cb_sec;
+	spin_unlock(&nn->client_lock);
+
+	nfsd4_probe_callback(session->se_client);
+
+	return nfs_ok;
+}
+
+static struct nfsd4_conn *__nfsd4_find_conn(struct svc_xprt *xpt, struct nfsd4_session *s)
+{
+	struct nfsd4_conn *c;
+
+	list_for_each_entry(c, &s->se_conns, cn_persession) {
+		if (c->cn_xprt == xpt) {
+			return c;
+		}
+	}
+	return NULL;
+}
+
+static __be32 nfsd4_match_existing_connection(struct svc_rqst *rqst,
+		struct nfsd4_session *session, u32 req, struct nfsd4_conn **conn)
+{
+	struct nfs4_client *clp = session->se_client;
+	struct svc_xprt *xpt = rqst->rq_xprt;
+	struct nfsd4_conn *c;
+	__be32 status;
+
+	/* Following the last paragraph of RFC 5661 Section 18.34.3: */
+	spin_lock(&clp->cl_lock);
+	c = __nfsd4_find_conn(xpt, session);
+	if (!c)
+		status = nfserr_noent;
+	else if (req == c->cn_flags)
+		status = nfs_ok;
+	else if (req == NFS4_CDFC4_FORE_OR_BOTH &&
+				c->cn_flags != NFS4_CDFC4_BACK)
+		status = nfs_ok;
+	else if (req == NFS4_CDFC4_BACK_OR_BOTH &&
+				c->cn_flags != NFS4_CDFC4_FORE)
+		status = nfs_ok;
+	else
+		status = nfserr_inval;
+	spin_unlock(&clp->cl_lock);
+	if (status == nfs_ok && conn)
+		*conn = c;
+	return status;
+}
+
+__be32 nfsd4_bind_conn_to_session(struct svc_rqst *rqstp,
+		     struct nfsd4_compound_state *cstate,
+		     union nfsd4_op_u *u)
+{
+	struct nfsd4_bind_conn_to_session *bcts = &u->bind_conn_to_session;
+	__be32 status;
+	struct nfsd4_conn *conn;
+	struct nfsd4_session *session;
+	struct net *net = SVC_NET(rqstp);
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	if (!nfsd4_last_compound_op(rqstp))
+		return nfserr_not_only_op;
+	spin_lock(&nn->client_lock);
+	session = find_in_sessionid_hashtbl(&bcts->sessionid, net, &status);
+	spin_unlock(&nn->client_lock);
+	if (!session)
+		goto out_no_session;
+	status = nfserr_wrong_cred;
+	if (!nfsd4_mach_creds_match(session->se_client, rqstp))
+		goto out;
+	status = nfsd4_match_existing_connection(rqstp, session,
+			bcts->dir, &conn);
+	if (status == nfs_ok) {
+		if (bcts->dir == NFS4_CDFC4_FORE_OR_BOTH ||
+				bcts->dir == NFS4_CDFC4_BACK)
+			conn->cn_flags |= NFS4_CDFC4_BACK;
+		nfsd4_probe_callback(session->se_client);
+		goto out;
+	}
+	if (status == nfserr_inval)
+		goto out;
+	status = nfsd4_map_bcts_dir(&bcts->dir);
+	if (status)
+		goto out;
+	conn = alloc_conn(rqstp, bcts->dir);
+	status = nfserr_jukebox;
+	if (!conn)
+		goto out;
+	nfsd4_init_conn(rqstp, conn, session);
+	status = nfs_ok;
+out:
+	nfsd4_put_session(session);
+out_no_session:
+	return status;
+}
+
+static bool nfsd4_compound_in_session(struct nfsd4_compound_state *cstate, struct nfs4_sessionid *sid)
+{
+	if (!cstate->session)
+		return false;
+	return !memcmp(sid, &cstate->session->se_sessionid, sizeof(*sid));
+}
+
+__be32
+nfsd4_destroy_session(struct svc_rqst *r, struct nfsd4_compound_state *cstate,
+		union nfsd4_op_u *u)
+{
+	struct nfs4_sessionid *sessionid = &u->destroy_session.sessionid;
+	struct nfsd4_session *ses;
+	__be32 status;
+	int ref_held_by_me = 0;
+	struct net *net = SVC_NET(r);
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	status = nfserr_not_only_op;
+	if (nfsd4_compound_in_session(cstate, sessionid)) {
+		if (!nfsd4_last_compound_op(r))
+			goto out;
+		ref_held_by_me++;
+	}
+	dump_sessionid(__func__, sessionid);
+	spin_lock(&nn->client_lock);
+	ses = find_in_sessionid_hashtbl(sessionid, net, &status);
+	if (!ses)
+		goto out_client_lock;
+	status = nfserr_wrong_cred;
+	if (!nfsd4_mach_creds_match(ses->se_client, r))
+		goto out_put_session;
+	status = mark_session_dead_locked(ses, 1 + ref_held_by_me);
+	if (status)
+		goto out_put_session;
+	unhash_session(ses);
+	spin_unlock(&nn->client_lock);
+
+	nfsd4_probe_callback_sync(ses->se_client);
+
+	spin_lock(&nn->client_lock);
+	status = nfs_ok;
+out_put_session:
+	nfsd4_put_session_locked(ses);
+out_client_lock:
+	spin_unlock(&nn->client_lock);
+out:
+	return status;
+}
+
+static __be32 nfsd4_sequence_check_conn(struct nfsd4_conn *new, struct nfsd4_session *ses)
+{
+	struct nfs4_client *clp = ses->se_client;
+	struct nfsd4_conn *c;
+	__be32 status = nfs_ok;
+	int ret;
+
+	spin_lock(&clp->cl_lock);
+	c = __nfsd4_find_conn(new->cn_xprt, ses);
+	if (c)
+		goto out_free;
+	status = nfserr_conn_not_bound_to_session;
+	if (clp->cl_mach_cred)
+		goto out_free;
+	__nfsd4_hash_conn(new, ses);
+	spin_unlock(&clp->cl_lock);
+	ret = nfsd4_register_conn(new);
+	if (ret)
+		/* oops; xprt is already down: */
+		nfsd4_conn_lost(&new->cn_xpt_user);
+	return nfs_ok;
+out_free:
+	spin_unlock(&clp->cl_lock);
+	free_conn(new);
+	return status;
+}
+
+static bool nfsd4_session_too_many_ops(struct svc_rqst *rqstp, struct nfsd4_session *session)
+{
+	struct nfsd4_compoundargs *args = rqstp->rq_argp;
+
+	return args->opcnt > session->se_fchannel.maxops;
+}
+
+static bool nfsd4_request_too_big(struct svc_rqst *rqstp,
+				  struct nfsd4_session *session)
+{
+	struct xdr_buf *xb = &rqstp->rq_arg;
+
+	return xb->len > session->se_fchannel.maxreq_sz;
+}
+
+static bool replay_matches_cache(struct svc_rqst *rqstp,
+		 struct nfsd4_sequence *seq, struct nfsd4_slot *slot)
+{
+	struct nfsd4_compoundargs *argp = rqstp->rq_argp;
+
+	if ((bool)(slot->sl_flags & NFSD4_SLOT_CACHETHIS) !=
+	    (bool)seq->cachethis)
+		return false;
+	/*
+	 * If there's an error then the reply can have fewer ops than
+	 * the call.
+	 */
+	if (slot->sl_opcnt < argp->opcnt && !slot->sl_status)
+		return false;
+	/*
+	 * But if we cached a reply with *more* ops than the call you're
+	 * sending us now, then this new call is clearly not really a
+	 * replay of the old one:
+	 */
+	if (slot->sl_opcnt > argp->opcnt)
+		return false;
+	/* This is the only check explicitly called by spec: */
+	if (!same_creds(&rqstp->rq_cred, &slot->sl_cred))
+		return false;
+	/*
+	 * There may be more comparisons we could actually do, but the
+	 * spec doesn't require us to catch every case where the calls
+	 * don't match (that would require caching the call as well as
+	 * the reply), so we don't bother.
+	 */
+	return true;
+}
+
+__be32
+nfsd4_sequence(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+		union nfsd4_op_u *u)
+{
+	struct nfsd4_sequence *seq = &u->sequence;
+	struct nfsd4_compoundres *resp = rqstp->rq_resp;
+	struct xdr_stream *xdr = &resp->xdr;
+	struct nfsd4_session *session;
+	struct nfs4_client *clp;
+	struct nfsd4_slot *slot;
+	struct nfsd4_conn *conn;
+	__be32 status;
+	int buflen;
+	struct net *net = SVC_NET(rqstp);
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	if (resp->opcnt != 1)
+		return nfserr_sequence_pos;
+
+	/*
+	 * Will be either used or freed by nfsd4_sequence_check_conn
+	 * below.
+	 */
+	conn = alloc_conn(rqstp, NFS4_CDFC4_FORE);
+	if (!conn)
+		return nfserr_jukebox;
+
+	spin_lock(&nn->client_lock);
+	session = find_in_sessionid_hashtbl(&seq->sessionid, net, &status);
+	if (!session)
+		goto out_no_session;
+	clp = session->se_client;
+
+	status = nfserr_too_many_ops;
+	if (nfsd4_session_too_many_ops(rqstp, session))
+		goto out_put_session;
+
+	status = nfserr_req_too_big;
+	if (nfsd4_request_too_big(rqstp, session))
+		goto out_put_session;
+
+	status = nfserr_badslot;
+	if (seq->slotid >= session->se_fchannel.maxreqs)
+		goto out_put_session;
+
+	slot = session->se_slots[seq->slotid];
+	dprintk("%s: slotid %d\n", __func__, seq->slotid);
+
+	/* We do not negotiate the number of slots yet, so set the
+	 * maxslots to the session maxreqs which is used to encode
+	 * sr_highest_slotid and the sr_target_slot id to maxslots */
+	seq->maxslots = session->se_fchannel.maxreqs;
+
+	status = check_slot_seqid(seq->seqid, slot->sl_seqid,
+					slot->sl_flags & NFSD4_SLOT_INUSE);
+	if (status == nfserr_replay_cache) {
+		status = nfserr_seq_misordered;
+		if (!(slot->sl_flags & NFSD4_SLOT_INITIALIZED))
+			goto out_put_session;
+		status = nfserr_seq_false_retry;
+		if (!replay_matches_cache(rqstp, seq, slot))
+			goto out_put_session;
+		cstate->slot = slot;
+		cstate->session = session;
+		cstate->clp = clp;
+		/* Return the cached reply status and set cstate->status
+		 * for nfsd4_proc_compound processing */
+		status = nfsd4_replay_cache_entry(resp, seq);
+		cstate->status = nfserr_replay_cache;
+		goto out;
+	}
+	if (status)
+		goto out_put_session;
+
+	status = nfsd4_sequence_check_conn(conn, session);
+	conn = NULL;
+	if (status)
+		goto out_put_session;
+
+	buflen = (seq->cachethis) ?
+			session->se_fchannel.maxresp_cached :
+			session->se_fchannel.maxresp_sz;
+	status = (seq->cachethis) ? nfserr_rep_too_big_to_cache :
+				    nfserr_rep_too_big;
+	if (xdr_restrict_buflen(xdr, buflen - rqstp->rq_auth_slack))
+		goto out_put_session;
+	svc_reserve(rqstp, buflen);
+
+	status = nfs_ok;
+	/* Success! bump slot seqid */
+	slot->sl_seqid = seq->seqid;
+	slot->sl_flags |= NFSD4_SLOT_INUSE;
+	if (seq->cachethis)
+		slot->sl_flags |= NFSD4_SLOT_CACHETHIS;
+	else
+		slot->sl_flags &= ~NFSD4_SLOT_CACHETHIS;
+
+	cstate->slot = slot;
+	cstate->session = session;
+	cstate->clp = clp;
+
+out:
+	switch (clp->cl_cb_state) {
+	case NFSD4_CB_DOWN:
+		seq->status_flags = SEQ4_STATUS_CB_PATH_DOWN;
+		break;
+	case NFSD4_CB_FAULT:
+		seq->status_flags = SEQ4_STATUS_BACKCHANNEL_FAULT;
+		break;
+	default:
+		seq->status_flags = 0;
+	}
+	if (!list_empty(&clp->cl_revoked))
+		seq->status_flags |= SEQ4_STATUS_RECALLABLE_STATE_REVOKED;
+out_no_session:
+	if (conn)
+		free_conn(conn);
+	spin_unlock(&nn->client_lock);
+	return status;
+out_put_session:
+	nfsd4_put_session_locked(session);
+	goto out_no_session;
+}
+
+void
+nfsd4_sequence_done(struct nfsd4_compoundres *resp)
+{
+	struct nfsd4_compound_state *cs = &resp->cstate;
+
+	if (nfsd4_has_session(cs)) {
+		if (cs->status != nfserr_replay_cache) {
+			nfsd4_store_cache_entry(resp);
+			cs->slot->sl_flags &= ~NFSD4_SLOT_INUSE;
+		}
+		/* Drop session reference that was taken in nfsd4_sequence() */
+		nfsd4_put_session(cs->session);
+	} else if (cs->clp)
+		put_client_renew(cs->clp);
+}
+
+__be32
+nfsd4_destroy_clientid(struct svc_rqst *rqstp,
+		struct nfsd4_compound_state *cstate,
+		union nfsd4_op_u *u)
+{
+	struct nfsd4_destroy_clientid *dc = &u->destroy_clientid;
+	struct nfs4_client *conf, *unconf;
+	struct nfs4_client *clp = NULL;
+	__be32 status = 0;
+	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+
+	spin_lock(&nn->client_lock);
+	unconf = find_unconfirmed_client(&dc->clientid, true, nn);
+	conf = find_confirmed_client(&dc->clientid, true, nn);
+	WARN_ON_ONCE(conf && unconf);
+
+	if (conf) {
+		if (client_has_state(conf)) {
+			status = nfserr_clientid_busy;
+			goto out;
+		}
+		status = mark_client_expired_locked(conf);
+		if (status)
+			goto out;
+		clp = conf;
+	} else if (unconf)
+		clp = unconf;
+	else {
+		status = nfserr_stale_clientid;
+		goto out;
+	}
+	if (!nfsd4_mach_creds_match(clp, rqstp)) {
+		clp = NULL;
+		status = nfserr_wrong_cred;
+		goto out;
+	}
+	unhash_client_locked(clp);
+out:
+	spin_unlock(&nn->client_lock);
+	if (clp)
+		expire_client(clp);
+	return status;
+}
+
+__be32
+nfsd4_reclaim_complete(struct svc_rqst *rqstp,
+		struct nfsd4_compound_state *cstate, union nfsd4_op_u *u)
+{
+	struct nfsd4_reclaim_complete *rc = &u->reclaim_complete;
+	__be32 status = 0;
+
+	if (rc->rca_one_fs) {
+		if (!cstate->current_fh.fh_dentry)
+			return nfserr_nofilehandle;
+		/*
+		 * We don't take advantage of the rca_one_fs case.
+		 * That's OK, it's optional, we can safely ignore it.
+		 */
+		return nfs_ok;
+	}
+
+	status = nfserr_complete_already;
+	if (test_and_set_bit(NFSD4_CLIENT_RECLAIM_COMPLETE,
+			     &cstate->session->se_client->cl_flags))
+		goto out;
+
+	status = nfserr_stale_clientid;
+	if (is_client_expired(cstate->session->se_client))
+		/*
+		 * The following error isn't really legal.
+		 * But we only get here if the client just explicitly
+		 * destroyed the client.  Surely it no longer cares what
+		 * error it gets back on an operation for the dead
+		 * client.
+		 */
+		goto out;
+
+	status = nfs_ok;
+	nfsd4_client_record_create(cstate->session->se_client);
+	inc_reclaim_complete(cstate->session->se_client);
+out:
+	return status;
+}
+
+__be32
+nfsd4_setclientid(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+		  union nfsd4_op_u *u)
+{
+	struct nfsd4_setclientid *setclid = &u->setclientid;
+	struct xdr_netobj 	clname = setclid->se_name;
+	nfs4_verifier		clverifier = setclid->se_verf;
+	struct nfs4_client	*conf, *new;
+	struct nfs4_client	*unconf = NULL;
+	__be32 			status;
+	struct nfsd_net		*nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+
+	new = create_client(clname, rqstp, &clverifier);
+	if (new == NULL)
+		return nfserr_jukebox;
+	/* Cases below refer to rfc 3530 section 14.2.33: */
+	spin_lock(&nn->client_lock);
+	conf = find_confirmed_client_by_name(&clname, nn);
+	if (conf && client_has_state(conf)) {
+		/* case 0: */
+		status = nfserr_clid_inuse;
+		if (clp_used_exchangeid(conf))
+			goto out;
+		if (!same_creds(&conf->cl_cred, &rqstp->rq_cred)) {
+			trace_nfsd_clid_inuse_err(conf);
+			goto out;
+		}
+	}
+	unconf = find_unconfirmed_client_by_name(&clname, nn);
+	if (unconf)
+		unhash_client_locked(unconf);
+	/* We need to handle only case 1: probable callback update */
+	if (conf && same_verf(&conf->cl_verifier, &clverifier)) {
+		copy_clid(new, conf);
+		gen_confirm(new, nn);
+	}
+	new->cl_minorversion = 0;
+	gen_callback(new, setclid, rqstp);
+	add_to_unconfirmed(new);
+	setclid->se_clientid.cl_boot = new->cl_clientid.cl_boot;
+	setclid->se_clientid.cl_id = new->cl_clientid.cl_id;
+	memcpy(setclid->se_confirm.data, new->cl_confirm.data, sizeof(setclid->se_confirm.data));
+	new = NULL;
+	status = nfs_ok;
+out:
+	spin_unlock(&nn->client_lock);
+	if (new)
+		free_client(new);
+	if (unconf)
+		expire_client(unconf);
+	return status;
+}
+
+
+__be32
+nfsd4_setclientid_confirm(struct svc_rqst *rqstp,
+			struct nfsd4_compound_state *cstate,
+			union nfsd4_op_u *u)
+{
+	struct nfsd4_setclientid_confirm *setclientid_confirm =
+			&u->setclientid_confirm;
+	struct nfs4_client *conf, *unconf;
+	struct nfs4_client *old = NULL;
+	nfs4_verifier confirm = setclientid_confirm->sc_confirm; 
+	clientid_t * clid = &setclientid_confirm->sc_clientid;
+	__be32 status;
+	struct nfsd_net	*nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+
+	if (STALE_CLIENTID(clid, nn))
+		return nfserr_stale_clientid;
+
+	spin_lock(&nn->client_lock);
+	conf = find_confirmed_client(clid, false, nn);
+	unconf = find_unconfirmed_client(clid, false, nn);
+	/*
+	 * We try hard to give out unique clientid's, so if we get an
+	 * attempt to confirm the same clientid with a different cred,
+	 * the client may be buggy; this should never happen.
+	 *
+	 * Nevertheless, RFC 7530 recommends INUSE for this case:
+	 */
+	status = nfserr_clid_inuse;
+	if (unconf && !same_creds(&unconf->cl_cred, &rqstp->rq_cred))
+		goto out;
+	if (conf && !same_creds(&conf->cl_cred, &rqstp->rq_cred))
+		goto out;
+	/* cases below refer to rfc 3530 section 14.2.34: */
+	if (!unconf || !same_verf(&confirm, &unconf->cl_confirm)) {
+		if (conf && same_verf(&confirm, &conf->cl_confirm)) {
+			/* case 2: probable retransmit */
+			status = nfs_ok;
+		} else /* case 4: client hasn't noticed we rebooted yet? */
+			status = nfserr_stale_clientid;
+		goto out;
+	}
+	status = nfs_ok;
+	if (conf) { /* case 1: callback update */
+		old = unconf;
+		unhash_client_locked(old);
+		nfsd4_change_callback(conf, &unconf->cl_cb_conn);
+	} else { /* case 3: normal case; new or rebooted client */
+		old = find_confirmed_client_by_name(&unconf->cl_name, nn);
+		if (old) {
+			status = nfserr_clid_inuse;
+			if (client_has_state(old)
+					&& !same_creds(&unconf->cl_cred,
+							&old->cl_cred)) {
+				old = NULL;
+				goto out;
+			}
+			status = mark_client_expired_locked(old);
+			if (status) {
+				old = NULL;
+				goto out;
+			}
+		}
+		move_to_confirmed(unconf);
+		conf = unconf;
+	}
+	get_client_locked(conf);
+	spin_unlock(&nn->client_lock);
+	nfsd4_probe_callback(conf);
+	spin_lock(&nn->client_lock);
+	put_client_renew_locked(conf);
+out:
+	spin_unlock(&nn->client_lock);
+	if (old)
+		expire_client(old);
+	return status;
+}
+
+static struct nfs4_file *nfsd4_alloc_file(void)
+{
+	return kmem_cache_alloc(file_slab, GFP_KERNEL);
+}
+
+/* OPEN Share state helper functions */
+static void nfsd4_init_file(struct knfsd_fh *fh, unsigned int hashval,
+				struct nfs4_file *fp)
+{
+	lockdep_assert_held(&state_lock);
+
+	refcount_set(&fp->fi_ref, 1);
+	spin_lock_init(&fp->fi_lock);
+	INIT_LIST_HEAD(&fp->fi_stateids);
+	INIT_LIST_HEAD(&fp->fi_delegations);
+	INIT_LIST_HEAD(&fp->fi_clnt_odstate);
+	fh_copy_shallow(&fp->fi_fhandle, fh);
+	fp->fi_deleg_file = NULL;
+	fp->fi_had_conflict = false;
+	fp->fi_share_deny = 0;
+	memset(fp->fi_fds, 0, sizeof(fp->fi_fds));
+	memset(fp->fi_access, 0, sizeof(fp->fi_access));
+#ifdef CONFIG_NFSD_PNFS
+	INIT_LIST_HEAD(&fp->fi_lo_states);
+	atomic_set(&fp->fi_lo_recalls, 0);
+#endif
+	hlist_add_head_rcu(&fp->fi_hash, &file_hashtbl[hashval]);
+}
+
+void
+nfsd4_free_slabs(void)
+{
+	kmem_cache_destroy(client_slab);
+	kmem_cache_destroy(openowner_slab);
+	kmem_cache_destroy(lockowner_slab);
+	kmem_cache_destroy(file_slab);
+	kmem_cache_destroy(stateid_slab);
+	kmem_cache_destroy(deleg_slab);
+	kmem_cache_destroy(odstate_slab);
+}
+
+int
+nfsd4_init_slabs(void)
+{
+	client_slab = kmem_cache_create("nfsd4_clients",
+			sizeof(struct nfs4_client), 0, 0, NULL);
+	if (client_slab == NULL)
+		goto out;
+	openowner_slab = kmem_cache_create("nfsd4_openowners",
+			sizeof(struct nfs4_openowner), 0, 0, NULL);
+	if (openowner_slab == NULL)
+		goto out_free_client_slab;
+	lockowner_slab = kmem_cache_create("nfsd4_lockowners",
+			sizeof(struct nfs4_lockowner), 0, 0, NULL);
+	if (lockowner_slab == NULL)
+		goto out_free_openowner_slab;
+	file_slab = kmem_cache_create("nfsd4_files",
+			sizeof(struct nfs4_file), 0, 0, NULL);
+	if (file_slab == NULL)
+		goto out_free_lockowner_slab;
+	stateid_slab = kmem_cache_create("nfsd4_stateids",
+			sizeof(struct nfs4_ol_stateid), 0, 0, NULL);
+	if (stateid_slab == NULL)
+		goto out_free_file_slab;
+	deleg_slab = kmem_cache_create("nfsd4_delegations",
+			sizeof(struct nfs4_delegation), 0, 0, NULL);
+	if (deleg_slab == NULL)
+		goto out_free_stateid_slab;
+	odstate_slab = kmem_cache_create("nfsd4_odstate",
+			sizeof(struct nfs4_clnt_odstate), 0, 0, NULL);
+	if (odstate_slab == NULL)
+		goto out_free_deleg_slab;
+	return 0;
+
+out_free_deleg_slab:
+	kmem_cache_destroy(deleg_slab);
+out_free_stateid_slab:
+	kmem_cache_destroy(stateid_slab);
+out_free_file_slab:
+	kmem_cache_destroy(file_slab);
+out_free_lockowner_slab:
+	kmem_cache_destroy(lockowner_slab);
+out_free_openowner_slab:
+	kmem_cache_destroy(openowner_slab);
+out_free_client_slab:
+	kmem_cache_destroy(client_slab);
+out:
+	return -ENOMEM;
+}
+
+static void init_nfs4_replay(struct nfs4_replay *rp)
+{
+	rp->rp_status = nfserr_serverfault;
+	rp->rp_buflen = 0;
+	rp->rp_buf = rp->rp_ibuf;
+	mutex_init(&rp->rp_mutex);
+}
+
+static void nfsd4_cstate_assign_replay(struct nfsd4_compound_state *cstate,
+		struct nfs4_stateowner *so)
+{
+	if (!nfsd4_has_session(cstate)) {
+		mutex_lock(&so->so_replay.rp_mutex);
+		cstate->replay_owner = nfs4_get_stateowner(so);
+	}
+}
+
+void nfsd4_cstate_clear_replay(struct nfsd4_compound_state *cstate)
+{
+	struct nfs4_stateowner *so = cstate->replay_owner;
+
+	if (so != NULL) {
+		cstate->replay_owner = NULL;
+		mutex_unlock(&so->so_replay.rp_mutex);
+		nfs4_put_stateowner(so);
+	}
+}
+
+static inline void *alloc_stateowner(struct kmem_cache *slab, struct xdr_netobj *owner, struct nfs4_client *clp)
+{
+	struct nfs4_stateowner *sop;
+
+	sop = kmem_cache_alloc(slab, GFP_KERNEL);
+	if (!sop)
+		return NULL;
+
+	xdr_netobj_dup(&sop->so_owner, owner, GFP_KERNEL);
+	if (!sop->so_owner.data) {
+		kmem_cache_free(slab, sop);
+		return NULL;
+	}
+
+	INIT_LIST_HEAD(&sop->so_stateids);
+	sop->so_client = clp;
+	init_nfs4_replay(&sop->so_replay);
+	atomic_set(&sop->so_count, 1);
+	return sop;
+}
+
+static void hash_openowner(struct nfs4_openowner *oo, struct nfs4_client *clp, unsigned int strhashval)
+{
+	lockdep_assert_held(&clp->cl_lock);
+
+	list_add(&oo->oo_owner.so_strhash,
+		 &clp->cl_ownerstr_hashtbl[strhashval]);
+	list_add(&oo->oo_perclient, &clp->cl_openowners);
+}
+
+static void nfs4_unhash_openowner(struct nfs4_stateowner *so)
+{
+	unhash_openowner_locked(openowner(so));
+}
+
+static void nfs4_free_openowner(struct nfs4_stateowner *so)
+{
+	struct nfs4_openowner *oo = openowner(so);
+
+	kmem_cache_free(openowner_slab, oo);
+}
+
+static const struct nfs4_stateowner_operations openowner_ops = {
+	.so_unhash =	nfs4_unhash_openowner,
+	.so_free =	nfs4_free_openowner,
+};
+
+static struct nfs4_ol_stateid *
+nfsd4_find_existing_open(struct nfs4_file *fp, struct nfsd4_open *open)
+{
+	struct nfs4_ol_stateid *local, *ret = NULL;
+	struct nfs4_openowner *oo = open->op_openowner;
+
+	lockdep_assert_held(&fp->fi_lock);
+
+	list_for_each_entry(local, &fp->fi_stateids, st_perfile) {
+		/* ignore lock owners */
+		if (local->st_stateowner->so_is_open_owner == 0)
+			continue;
+		if (local->st_stateowner != &oo->oo_owner)
+			continue;
+		if (local->st_stid.sc_type == NFS4_OPEN_STID) {
+			ret = local;
+			refcount_inc(&ret->st_stid.sc_count);
+			break;
+		}
+	}
+	return ret;
+}
+
+static __be32
+nfsd4_verify_open_stid(struct nfs4_stid *s)
+{
+	__be32 ret = nfs_ok;
+
+	switch (s->sc_type) {
+	default:
+		break;
+	case 0:
+	case NFS4_CLOSED_STID:
+	case NFS4_CLOSED_DELEG_STID:
+		ret = nfserr_bad_stateid;
+		break;
+	case NFS4_REVOKED_DELEG_STID:
+		ret = nfserr_deleg_revoked;
+	}
+	return ret;
+}
+
+/* Lock the stateid st_mutex, and deal with races with CLOSE */
+static __be32
+nfsd4_lock_ol_stateid(struct nfs4_ol_stateid *stp)
+{
+	__be32 ret;
+
+	mutex_lock_nested(&stp->st_mutex, LOCK_STATEID_MUTEX);
+	ret = nfsd4_verify_open_stid(&stp->st_stid);
+	if (ret != nfs_ok)
+		mutex_unlock(&stp->st_mutex);
+	return ret;
+}
+
+static struct nfs4_ol_stateid *
+nfsd4_find_and_lock_existing_open(struct nfs4_file *fp, struct nfsd4_open *open)
+{
+	struct nfs4_ol_stateid *stp;
+	for (;;) {
+		spin_lock(&fp->fi_lock);
+		stp = nfsd4_find_existing_open(fp, open);
+		spin_unlock(&fp->fi_lock);
+		if (!stp || nfsd4_lock_ol_stateid(stp) == nfs_ok)
+			break;
+		nfs4_put_stid(&stp->st_stid);
+	}
+	return stp;
+}
+
+static struct nfs4_openowner *
+alloc_init_open_stateowner(unsigned int strhashval, struct nfsd4_open *open,
+			   struct nfsd4_compound_state *cstate)
+{
+	struct nfs4_client *clp = cstate->clp;
+	struct nfs4_openowner *oo, *ret;
+
+	oo = alloc_stateowner(openowner_slab, &open->op_owner, clp);
+	if (!oo)
+		return NULL;
+	oo->oo_owner.so_ops = &openowner_ops;
+	oo->oo_owner.so_is_open_owner = 1;
+	oo->oo_owner.so_seqid = open->op_seqid;
+	oo->oo_flags = 0;
+	if (nfsd4_has_session(cstate))
+		oo->oo_flags |= NFS4_OO_CONFIRMED;
+	oo->oo_time = 0;
+	oo->oo_last_closed_stid = NULL;
+	INIT_LIST_HEAD(&oo->oo_close_lru);
+	spin_lock(&clp->cl_lock);
+	ret = find_openstateowner_str_locked(strhashval, open, clp);
+	if (ret == NULL) {
+		hash_openowner(oo, clp, strhashval);
+		ret = oo;
+	} else
+		nfs4_free_stateowner(&oo->oo_owner);
+
+	spin_unlock(&clp->cl_lock);
+	return ret;
+}
+
+static struct nfs4_ol_stateid *
+init_open_stateid(struct nfs4_file *fp, struct nfsd4_open *open)
+{
+
+	struct nfs4_openowner *oo = open->op_openowner;
+	struct nfs4_ol_stateid *retstp = NULL;
+	struct nfs4_ol_stateid *stp;
+
+	stp = open->op_stp;
+	/* We are moving these outside of the spinlocks to avoid the warnings */
+	mutex_init(&stp->st_mutex);
+	mutex_lock_nested(&stp->st_mutex, OPEN_STATEID_MUTEX);
+
+retry:
+	spin_lock(&oo->oo_owner.so_client->cl_lock);
+	spin_lock(&fp->fi_lock);
+
+	retstp = nfsd4_find_existing_open(fp, open);
+	if (retstp)
+		goto out_unlock;
+
+	open->op_stp = NULL;
+	refcount_inc(&stp->st_stid.sc_count);
+	stp->st_stid.sc_type = NFS4_OPEN_STID;
+	INIT_LIST_HEAD(&stp->st_locks);
+	stp->st_stateowner = nfs4_get_stateowner(&oo->oo_owner);
+	get_nfs4_file(fp);
+	stp->st_stid.sc_file = fp;
+	stp->st_access_bmap = 0;
+	stp->st_deny_bmap = 0;
+	stp->st_openstp = NULL;
+	list_add(&stp->st_perstateowner, &oo->oo_owner.so_stateids);
+	list_add(&stp->st_perfile, &fp->fi_stateids);
+
+out_unlock:
+	spin_unlock(&fp->fi_lock);
+	spin_unlock(&oo->oo_owner.so_client->cl_lock);
+	if (retstp) {
+		/* Handle races with CLOSE */
+		if (nfsd4_lock_ol_stateid(retstp) != nfs_ok) {
+			nfs4_put_stid(&retstp->st_stid);
+			goto retry;
+		}
+		/* To keep mutex tracking happy */
+		mutex_unlock(&stp->st_mutex);
+		stp = retstp;
+	}
+	return stp;
+}
+
+/*
+ * In the 4.0 case we need to keep the owners around a little while to handle
+ * CLOSE replay. We still do need to release any file access that is held by
+ * them before returning however.
+ */
+static void
+move_to_close_lru(struct nfs4_ol_stateid *s, struct net *net)
+{
+	struct nfs4_ol_stateid *last;
+	struct nfs4_openowner *oo = openowner(s->st_stateowner);
+	struct nfsd_net *nn = net_generic(s->st_stid.sc_client->net,
+						nfsd_net_id);
+
+	dprintk("NFSD: move_to_close_lru nfs4_openowner %p\n", oo);
+
+	/*
+	 * We know that we hold one reference via nfsd4_close, and another
+	 * "persistent" reference for the client. If the refcount is higher
+	 * than 2, then there are still calls in progress that are using this
+	 * stateid. We can't put the sc_file reference until they are finished.
+	 * Wait for the refcount to drop to 2. Since it has been unhashed,
+	 * there should be no danger of the refcount going back up again at
+	 * this point.
+	 */
+	wait_event(close_wq, refcount_read(&s->st_stid.sc_count) == 2);
+
+	release_all_access(s);
+	if (s->st_stid.sc_file) {
+		put_nfs4_file(s->st_stid.sc_file);
+		s->st_stid.sc_file = NULL;
+	}
+
+	spin_lock(&nn->client_lock);
+	last = oo->oo_last_closed_stid;
+	oo->oo_last_closed_stid = s;
+	list_move_tail(&oo->oo_close_lru, &nn->close_lru);
+	oo->oo_time = ktime_get_boottime_seconds();
+	spin_unlock(&nn->client_lock);
+	if (last)
+		nfs4_put_stid(&last->st_stid);
+}
+
+/* search file_hashtbl[] for file */
+static struct nfs4_file *
+find_file_locked(struct knfsd_fh *fh, unsigned int hashval)
+{
+	struct nfs4_file *fp;
+
+	hlist_for_each_entry_rcu(fp, &file_hashtbl[hashval], fi_hash,
+				lockdep_is_held(&state_lock)) {
+		if (fh_match(&fp->fi_fhandle, fh)) {
+			if (refcount_inc_not_zero(&fp->fi_ref))
+				return fp;
+		}
+	}
+	return NULL;
+}
+
+struct nfs4_file *
+find_file(struct knfsd_fh *fh)
+{
+	struct nfs4_file *fp;
+	unsigned int hashval = file_hashval(fh);
+
+	rcu_read_lock();
+	fp = find_file_locked(fh, hashval);
+	rcu_read_unlock();
+	return fp;
+}
+
+static struct nfs4_file *
+find_or_add_file(struct nfs4_file *new, struct knfsd_fh *fh)
+{
+	struct nfs4_file *fp;
+	unsigned int hashval = file_hashval(fh);
+
+	rcu_read_lock();
+	fp = find_file_locked(fh, hashval);
+	rcu_read_unlock();
+	if (fp)
+		return fp;
+
+	spin_lock(&state_lock);
+	fp = find_file_locked(fh, hashval);
+	if (likely(fp == NULL)) {
+		nfsd4_init_file(fh, hashval, new);
+		fp = new;
+	}
+	spin_unlock(&state_lock);
+
+	return fp;
+}
+
+/*
+ * Called to check deny when READ with all zero stateid or
+ * WRITE with all zero or all one stateid
+ */
+static __be32
+nfs4_share_conflict(struct svc_fh *current_fh, unsigned int deny_type)
+{
+	struct nfs4_file *fp;
+	__be32 ret = nfs_ok;
+
+	fp = find_file(&current_fh->fh_handle);
+	if (!fp)
+		return ret;
+	/* Check for conflicting share reservations */
+	spin_lock(&fp->fi_lock);
+	if (fp->fi_share_deny & deny_type)
+		ret = nfserr_locked;
+	spin_unlock(&fp->fi_lock);
+	put_nfs4_file(fp);
+	return ret;
+}
+
+static void nfsd4_cb_recall_prepare(struct nfsd4_callback *cb)
+{
+	struct nfs4_delegation *dp = cb_to_delegation(cb);
+	struct nfsd_net *nn = net_generic(dp->dl_stid.sc_client->net,
+					  nfsd_net_id);
+
+	block_delegations(&dp->dl_stid.sc_file->fi_fhandle);
+
+	/*
+	 * We can't do this in nfsd_break_deleg_cb because it is
+	 * already holding inode->i_lock.
+	 *
+	 * If the dl_time != 0, then we know that it has already been
+	 * queued for a lease break. Don't queue it again.
+	 */
+	spin_lock(&state_lock);
+	if (delegation_hashed(dp) && dp->dl_time == 0) {
+		dp->dl_time = ktime_get_boottime_seconds();
+		list_add_tail(&dp->dl_recall_lru, &nn->del_recall_lru);
+	}
+	spin_unlock(&state_lock);
+}
+
+static int nfsd4_cb_recall_done(struct nfsd4_callback *cb,
+		struct rpc_task *task)
+{
+	struct nfs4_delegation *dp = cb_to_delegation(cb);
+
+	if (dp->dl_stid.sc_type == NFS4_CLOSED_DELEG_STID ||
+	    dp->dl_stid.sc_type == NFS4_REVOKED_DELEG_STID)
+	        return 1;
+
+	switch (task->tk_status) {
+	case 0:
+		return 1;
+	case -NFS4ERR_DELAY:
+		rpc_delay(task, 2 * HZ);
+		return 0;
+	case -EBADHANDLE:
+	case -NFS4ERR_BAD_STATEID:
+		/*
+		 * Race: client probably got cb_recall before open reply
+		 * granting delegation.
+		 */
+		if (dp->dl_retries--) {
+			rpc_delay(task, 2 * HZ);
+			return 0;
+		}
+		fallthrough;
+	default:
+		return 1;
+	}
+}
+
+static void nfsd4_cb_recall_release(struct nfsd4_callback *cb)
+{
+	struct nfs4_delegation *dp = cb_to_delegation(cb);
+
+	nfs4_put_stid(&dp->dl_stid);
+}
+
+static const struct nfsd4_callback_ops nfsd4_cb_recall_ops = {
+	.prepare	= nfsd4_cb_recall_prepare,
+	.done		= nfsd4_cb_recall_done,
+	.release	= nfsd4_cb_recall_release,
+};
+
+static void nfsd_break_one_deleg(struct nfs4_delegation *dp)
+{
+	/*
+	 * We're assuming the state code never drops its reference
+	 * without first removing the lease.  Since we're in this lease
+	 * callback (and since the lease code is serialized by the
+	 * i_lock) we know the server hasn't removed the lease yet, and
+	 * we know it's safe to take a reference.
+	 */
+	refcount_inc(&dp->dl_stid.sc_count);
+	nfsd4_run_cb(&dp->dl_recall);
+}
+
+/* Called from break_lease() with i_lock held. */
+static bool
+nfsd_break_deleg_cb(struct file_lock *fl)
+{
+	bool ret = false;
+	struct nfs4_delegation *dp = (struct nfs4_delegation *)fl->fl_owner;
+	struct nfs4_file *fp = dp->dl_stid.sc_file;
+
+	trace_nfsd_deleg_break(&dp->dl_stid.sc_stateid);
+
+	/*
+	 * We don't want the locks code to timeout the lease for us;
+	 * we'll remove it ourself if a delegation isn't returned
+	 * in time:
+	 */
+	fl->fl_break_time = 0;
+
+	spin_lock(&fp->fi_lock);
+	fp->fi_had_conflict = true;
+	nfsd_break_one_deleg(dp);
+	spin_unlock(&fp->fi_lock);
+	return ret;
+}
+
+/**
+ * nfsd_breaker_owns_lease - Check if lease conflict was resolved
+ * @fl: Lock state to check
+ *
+ * Return values:
+ *   %true: Lease conflict was resolved
+ *   %false: Lease conflict was not resolved.
+ */
+static bool nfsd_breaker_owns_lease(struct file_lock *fl)
+{
+	struct nfs4_delegation *dl = fl->fl_owner;
+	struct svc_rqst *rqst;
+	struct nfs4_client *clp;
+
+	if (!i_am_nfsd())
+		return false;
+	rqst = kthread_data(current);
+	/* Note rq_prog == NFS_ACL_PROGRAM is also possible: */
+	if (rqst->rq_prog != NFS_PROGRAM || rqst->rq_vers < 4)
+		return false;
+	clp = *(rqst->rq_lease_breaker);
+	return dl->dl_stid.sc_client == clp;
+}
+
+static int
+nfsd_change_deleg_cb(struct file_lock *onlist, int arg,
+		     struct list_head *dispose)
+{
+	if (arg & F_UNLCK)
+		return lease_modify(onlist, arg, dispose);
+	else
+		return -EAGAIN;
+}
+
+static const struct lock_manager_operations nfsd_lease_mng_ops = {
+	.lm_breaker_owns_lease = nfsd_breaker_owns_lease,
+	.lm_break = nfsd_break_deleg_cb,
+	.lm_change = nfsd_change_deleg_cb,
+};
+
+static __be32 nfsd4_check_seqid(struct nfsd4_compound_state *cstate, struct nfs4_stateowner *so, u32 seqid)
+{
+	if (nfsd4_has_session(cstate))
+		return nfs_ok;
+	if (seqid == so->so_seqid - 1)
+		return nfserr_replay_me;
+	if (seqid == so->so_seqid)
+		return nfs_ok;
+	return nfserr_bad_seqid;
+}
+
+static __be32 lookup_clientid(clientid_t *clid,
+		struct nfsd4_compound_state *cstate,
+		struct nfsd_net *nn,
+		bool sessions)
+{
+	struct nfs4_client *found;
+
+	if (cstate->clp) {
+		found = cstate->clp;
+		if (!same_clid(&found->cl_clientid, clid))
+			return nfserr_stale_clientid;
+		return nfs_ok;
+	}
+
+	if (STALE_CLIENTID(clid, nn))
+		return nfserr_stale_clientid;
+
+	/*
+	 * For v4.1+ we get the client in the SEQUENCE op. If we don't have one
+	 * cached already then we know this is for is for v4.0 and "sessions"
+	 * will be false.
+	 */
+	WARN_ON_ONCE(cstate->session);
+	spin_lock(&nn->client_lock);
+	found = find_confirmed_client(clid, sessions, nn);
+	if (!found) {
+		spin_unlock(&nn->client_lock);
+		return nfserr_expired;
+	}
+	atomic_inc(&found->cl_rpc_users);
+	spin_unlock(&nn->client_lock);
+
+	/* Cache the nfs4_client in cstate! */
+	cstate->clp = found;
+	return nfs_ok;
+}
+
+__be32
+nfsd4_process_open1(struct nfsd4_compound_state *cstate,
+		    struct nfsd4_open *open, struct nfsd_net *nn)
+{
+	clientid_t *clientid = &open->op_clientid;
+	struct nfs4_client *clp = NULL;
+	unsigned int strhashval;
+	struct nfs4_openowner *oo = NULL;
+	__be32 status;
+
+	if (STALE_CLIENTID(&open->op_clientid, nn))
+		return nfserr_stale_clientid;
+	/*
+	 * In case we need it later, after we've already created the
+	 * file and don't want to risk a further failure:
+	 */
+	open->op_file = nfsd4_alloc_file();
+	if (open->op_file == NULL)
+		return nfserr_jukebox;
+
+	status = lookup_clientid(clientid, cstate, nn, false);
+	if (status)
+		return status;
+	clp = cstate->clp;
+
+	strhashval = ownerstr_hashval(&open->op_owner);
+	oo = find_openstateowner_str(strhashval, open, clp);
+	open->op_openowner = oo;
+	if (!oo) {
+		goto new_owner;
+	}
+	if (!(oo->oo_flags & NFS4_OO_CONFIRMED)) {
+		/* Replace unconfirmed owners without checking for replay. */
+		release_openowner(oo);
+		open->op_openowner = NULL;
+		goto new_owner;
+	}
+	status = nfsd4_check_seqid(cstate, &oo->oo_owner, open->op_seqid);
+	if (status)
+		return status;
+	goto alloc_stateid;
+new_owner:
+	oo = alloc_init_open_stateowner(strhashval, open, cstate);
+	if (oo == NULL)
+		return nfserr_jukebox;
+	open->op_openowner = oo;
+alloc_stateid:
+	open->op_stp = nfs4_alloc_open_stateid(clp);
+	if (!open->op_stp)
+		return nfserr_jukebox;
+
+	if (nfsd4_has_session(cstate) &&
+	    (cstate->current_fh.fh_export->ex_flags & NFSEXP_PNFS)) {
+		open->op_odstate = alloc_clnt_odstate(clp);
+		if (!open->op_odstate)
+			return nfserr_jukebox;
+	}
+
+	return nfs_ok;
+}
+
+static inline __be32
+nfs4_check_delegmode(struct nfs4_delegation *dp, int flags)
+{
+	if ((flags & WR_STATE) && (dp->dl_type == NFS4_OPEN_DELEGATE_READ))
+		return nfserr_openmode;
+	else
+		return nfs_ok;
+}
+
+static int share_access_to_flags(u32 share_access)
+{
+	return share_access == NFS4_SHARE_ACCESS_READ ? RD_STATE : WR_STATE;
+}
+
+static struct nfs4_delegation *find_deleg_stateid(struct nfs4_client *cl, stateid_t *s)
+{
+	struct nfs4_stid *ret;
+
+	ret = find_stateid_by_type(cl, s,
+				NFS4_DELEG_STID|NFS4_REVOKED_DELEG_STID);
+	if (!ret)
+		return NULL;
+	return delegstateid(ret);
+}
+
+static bool nfsd4_is_deleg_cur(struct nfsd4_open *open)
+{
+	return open->op_claim_type == NFS4_OPEN_CLAIM_DELEGATE_CUR ||
+	       open->op_claim_type == NFS4_OPEN_CLAIM_DELEG_CUR_FH;
+}
+
+static __be32
+nfs4_check_deleg(struct nfs4_client *cl, struct nfsd4_open *open,
+		struct nfs4_delegation **dp)
+{
+	int flags;
+	__be32 status = nfserr_bad_stateid;
+	struct nfs4_delegation *deleg;
+
+	deleg = find_deleg_stateid(cl, &open->op_delegate_stateid);
+	if (deleg == NULL)
+		goto out;
+	if (deleg->dl_stid.sc_type == NFS4_REVOKED_DELEG_STID) {
+		nfs4_put_stid(&deleg->dl_stid);
+		if (cl->cl_minorversion)
+			status = nfserr_deleg_revoked;
+		goto out;
+	}
+	flags = share_access_to_flags(open->op_share_access);
+	status = nfs4_check_delegmode(deleg, flags);
+	if (status) {
+		nfs4_put_stid(&deleg->dl_stid);
+		goto out;
+	}
+	*dp = deleg;
+out:
+	if (!nfsd4_is_deleg_cur(open))
+		return nfs_ok;
+	if (status)
+		return status;
+	open->op_openowner->oo_flags |= NFS4_OO_CONFIRMED;
+	return nfs_ok;
+}
+
+static inline int nfs4_access_to_access(u32 nfs4_access)
+{
+	int flags = 0;
+
+	if (nfs4_access & NFS4_SHARE_ACCESS_READ)
+		flags |= NFSD_MAY_READ;
+	if (nfs4_access & NFS4_SHARE_ACCESS_WRITE)
+		flags |= NFSD_MAY_WRITE;
+	return flags;
+}
+
+static inline __be32
+nfsd4_truncate(struct svc_rqst *rqstp, struct svc_fh *fh,
+		struct nfsd4_open *open)
+{
+	struct iattr iattr = {
+		.ia_valid = ATTR_SIZE,
+		.ia_size = 0,
+	};
+	if (!open->op_truncate)
+		return 0;
+	if (!(open->op_share_access & NFS4_SHARE_ACCESS_WRITE))
+		return nfserr_inval;
+	return nfsd_setattr(rqstp, fh, &iattr, 0, (time64_t)0);
+}
+
+static __be32 nfs4_get_vfs_file(struct svc_rqst *rqstp, struct nfs4_file *fp,
+		struct svc_fh *cur_fh, struct nfs4_ol_stateid *stp,
+		struct nfsd4_open *open)
+{
+	struct nfsd_file *nf = NULL;
+	__be32 status;
+	int oflag = nfs4_access_to_omode(open->op_share_access);
+	int access = nfs4_access_to_access(open->op_share_access);
+	unsigned char old_access_bmap, old_deny_bmap;
+
+	spin_lock(&fp->fi_lock);
+
+	/*
+	 * Are we trying to set a deny mode that would conflict with
+	 * current access?
+	 */
+	status = nfs4_file_check_deny(fp, open->op_share_deny);
+	if (status != nfs_ok) {
+		spin_unlock(&fp->fi_lock);
+		goto out;
+	}
+
+	/* set access to the file */
+	status = nfs4_file_get_access(fp, open->op_share_access);
+	if (status != nfs_ok) {
+		spin_unlock(&fp->fi_lock);
+		goto out;
+	}
+
+	/* Set access bits in stateid */
+	old_access_bmap = stp->st_access_bmap;
+	set_access(open->op_share_access, stp);
+
+	/* Set new deny mask */
+	old_deny_bmap = stp->st_deny_bmap;
+	set_deny(open->op_share_deny, stp);
+	fp->fi_share_deny |= (open->op_share_deny & NFS4_SHARE_DENY_BOTH);
+
+	if (!fp->fi_fds[oflag]) {
+		spin_unlock(&fp->fi_lock);
+		status = nfsd_file_acquire(rqstp, cur_fh, access, &nf);
+		if (status)
+			goto out_put_access;
+		spin_lock(&fp->fi_lock);
+		if (!fp->fi_fds[oflag]) {
+			fp->fi_fds[oflag] = nf;
+			nf = NULL;
+		}
+	}
+	spin_unlock(&fp->fi_lock);
+	if (nf)
+		nfsd_file_put(nf);
+
+	status = nfserrno(nfsd_open_break_lease(cur_fh->fh_dentry->d_inode,
+								access));
+	if (status)
+		goto out_put_access;
+
+	status = nfsd4_truncate(rqstp, cur_fh, open);
+	if (status)
+		goto out_put_access;
+out:
+	return status;
+out_put_access:
+	stp->st_access_bmap = old_access_bmap;
+	nfs4_file_put_access(fp, open->op_share_access);
+	reset_union_bmap_deny(bmap_to_share_mode(old_deny_bmap), stp);
+	goto out;
+}
+
+static __be32
+nfs4_upgrade_open(struct svc_rqst *rqstp, struct nfs4_file *fp, struct svc_fh *cur_fh, struct nfs4_ol_stateid *stp, struct nfsd4_open *open)
+{
+	__be32 status;
+	unsigned char old_deny_bmap = stp->st_deny_bmap;
+
+	if (!test_access(open->op_share_access, stp))
+		return nfs4_get_vfs_file(rqstp, fp, cur_fh, stp, open);
+
+	/* test and set deny mode */
+	spin_lock(&fp->fi_lock);
+	status = nfs4_file_check_deny(fp, open->op_share_deny);
+	if (status == nfs_ok) {
+		set_deny(open->op_share_deny, stp);
+		fp->fi_share_deny |=
+				(open->op_share_deny & NFS4_SHARE_DENY_BOTH);
+	}
+	spin_unlock(&fp->fi_lock);
+
+	if (status != nfs_ok)
+		return status;
+
+	status = nfsd4_truncate(rqstp, cur_fh, open);
+	if (status != nfs_ok)
+		reset_union_bmap_deny(old_deny_bmap, stp);
+	return status;
+}
+
+/* Should we give out recallable state?: */
+static bool nfsd4_cb_channel_good(struct nfs4_client *clp)
+{
+	if (clp->cl_cb_state == NFSD4_CB_UP)
+		return true;
+	/*
+	 * In the sessions case, since we don't have to establish a
+	 * separate connection for callbacks, we assume it's OK
+	 * until we hear otherwise:
+	 */
+	return clp->cl_minorversion && clp->cl_cb_state == NFSD4_CB_UNKNOWN;
+}
+
+static struct file_lock *nfs4_alloc_init_lease(struct nfs4_delegation *dp,
+						int flag)
+{
+	struct file_lock *fl;
+
+	fl = locks_alloc_lock();
+	if (!fl)
+		return NULL;
+	fl->fl_lmops = &nfsd_lease_mng_ops;
+	fl->fl_flags = FL_DELEG;
+	fl->fl_type = flag == NFS4_OPEN_DELEGATE_READ? F_RDLCK: F_WRLCK;
+	fl->fl_end = OFFSET_MAX;
+	fl->fl_owner = (fl_owner_t)dp;
+	fl->fl_pid = current->tgid;
+	fl->fl_file = dp->dl_stid.sc_file->fi_deleg_file->nf_file;
+	return fl;
+}
+
+static struct nfs4_delegation *
+nfs4_set_delegation(struct nfs4_client *clp, struct svc_fh *fh,
+		    struct nfs4_file *fp, struct nfs4_clnt_odstate *odstate)
+{
+	int status = 0;
+	struct nfs4_delegation *dp;
+	struct nfsd_file *nf;
+	struct file_lock *fl;
+
+	/*
+	 * The fi_had_conflict and nfs_get_existing_delegation checks
+	 * here are just optimizations; we'll need to recheck them at
+	 * the end:
+	 */
+	if (fp->fi_had_conflict)
+		return ERR_PTR(-EAGAIN);
+
+	nf = find_readable_file(fp);
+	if (!nf) {
+		/* We should always have a readable file here */
+		WARN_ON_ONCE(1);
+		return ERR_PTR(-EBADF);
+	}
+	spin_lock(&state_lock);
+	spin_lock(&fp->fi_lock);
+	if (nfs4_delegation_exists(clp, fp))
+		status = -EAGAIN;
+	else if (!fp->fi_deleg_file) {
+		fp->fi_deleg_file = nf;
+		/* increment early to prevent fi_deleg_file from being
+		 * cleared */
+		fp->fi_delegees = 1;
+		nf = NULL;
+	} else
+		fp->fi_delegees++;
+	spin_unlock(&fp->fi_lock);
+	spin_unlock(&state_lock);
+	if (nf)
+		nfsd_file_put(nf);
+	if (status)
+		return ERR_PTR(status);
+
+	status = -ENOMEM;
+	dp = alloc_init_deleg(clp, fp, fh, odstate);
+	if (!dp)
+		goto out_delegees;
+
+	fl = nfs4_alloc_init_lease(dp, NFS4_OPEN_DELEGATE_READ);
+	if (!fl)
+		goto out_clnt_odstate;
+
+	status = vfs_setlease(fp->fi_deleg_file->nf_file, fl->fl_type, &fl, NULL);
+	if (fl)
+		locks_free_lock(fl);
+	if (status)
+		goto out_clnt_odstate;
+
+	spin_lock(&state_lock);
+	spin_lock(&fp->fi_lock);
+	if (fp->fi_had_conflict)
+		status = -EAGAIN;
+	else
+		status = hash_delegation_locked(dp, fp);
+	spin_unlock(&fp->fi_lock);
+	spin_unlock(&state_lock);
+
+	if (status)
+		goto out_unlock;
+
+	return dp;
+out_unlock:
+	vfs_setlease(fp->fi_deleg_file->nf_file, F_UNLCK, NULL, (void **)&dp);
+out_clnt_odstate:
+	put_clnt_odstate(dp->dl_clnt_odstate);
+	nfs4_put_stid(&dp->dl_stid);
+out_delegees:
+	put_deleg_file(fp);
+	return ERR_PTR(status);
+}
+
+static void nfsd4_open_deleg_none_ext(struct nfsd4_open *open, int status)
+{
+	open->op_delegate_type = NFS4_OPEN_DELEGATE_NONE_EXT;
+	if (status == -EAGAIN)
+		open->op_why_no_deleg = WND4_CONTENTION;
+	else {
+		open->op_why_no_deleg = WND4_RESOURCE;
+		switch (open->op_deleg_want) {
+		case NFS4_SHARE_WANT_READ_DELEG:
+		case NFS4_SHARE_WANT_WRITE_DELEG:
+		case NFS4_SHARE_WANT_ANY_DELEG:
+			break;
+		case NFS4_SHARE_WANT_CANCEL:
+			open->op_why_no_deleg = WND4_CANCELLED;
+			break;
+		case NFS4_SHARE_WANT_NO_DELEG:
+			WARN_ON_ONCE(1);
+		}
+	}
+}
+
+/*
+ * Attempt to hand out a delegation.
+ *
+ * Note we don't support write delegations, and won't until the vfs has
+ * proper support for them.
+ */
+static void
+nfs4_open_delegation(struct svc_fh *fh, struct nfsd4_open *open,
+			struct nfs4_ol_stateid *stp)
+{
+	struct nfs4_delegation *dp;
+	struct nfs4_openowner *oo = openowner(stp->st_stateowner);
+	struct nfs4_client *clp = stp->st_stid.sc_client;
+	int cb_up;
+	int status = 0;
+
+	cb_up = nfsd4_cb_channel_good(oo->oo_owner.so_client);
+	open->op_recall = 0;
+	switch (open->op_claim_type) {
+		case NFS4_OPEN_CLAIM_PREVIOUS:
+			if (!cb_up)
+				open->op_recall = 1;
+			if (open->op_delegate_type != NFS4_OPEN_DELEGATE_READ)
+				goto out_no_deleg;
+			break;
+		case NFS4_OPEN_CLAIM_NULL:
+		case NFS4_OPEN_CLAIM_FH:
+			/*
+			 * Let's not give out any delegations till everyone's
+			 * had the chance to reclaim theirs, *and* until
+			 * NLM locks have all been reclaimed:
+			 */
+			if (locks_in_grace(clp->net))
+				goto out_no_deleg;
+			if (!cb_up || !(oo->oo_flags & NFS4_OO_CONFIRMED))
+				goto out_no_deleg;
+			/*
+			 * Also, if the file was opened for write or
+			 * create, there's a good chance the client's
+			 * about to write to it, resulting in an
+			 * immediate recall (since we don't support
+			 * write delegations):
+			 */
+			if (open->op_share_access & NFS4_SHARE_ACCESS_WRITE)
+				goto out_no_deleg;
+			if (open->op_create == NFS4_OPEN_CREATE)
+				goto out_no_deleg;
+			break;
+		default:
+			goto out_no_deleg;
+	}
+	dp = nfs4_set_delegation(clp, fh, stp->st_stid.sc_file, stp->st_clnt_odstate);
+	if (IS_ERR(dp))
+		goto out_no_deleg;
+
+	memcpy(&open->op_delegate_stateid, &dp->dl_stid.sc_stateid, sizeof(dp->dl_stid.sc_stateid));
+
+	trace_nfsd_deleg_read(&dp->dl_stid.sc_stateid);
+	open->op_delegate_type = NFS4_OPEN_DELEGATE_READ;
+	nfs4_put_stid(&dp->dl_stid);
+	return;
+out_no_deleg:
+	open->op_delegate_type = NFS4_OPEN_DELEGATE_NONE;
+	if (open->op_claim_type == NFS4_OPEN_CLAIM_PREVIOUS &&
+	    open->op_delegate_type != NFS4_OPEN_DELEGATE_NONE) {
+		dprintk("NFSD: WARNING: refusing delegation reclaim\n");
+		open->op_recall = 1;
+	}
+
+	/* 4.1 client asking for a delegation? */
+	if (open->op_deleg_want)
+		nfsd4_open_deleg_none_ext(open, status);
+	return;
+}
+
+static void nfsd4_deleg_xgrade_none_ext(struct nfsd4_open *open,
+					struct nfs4_delegation *dp)
+{
+	if (open->op_deleg_want == NFS4_SHARE_WANT_READ_DELEG &&
+	    dp->dl_type == NFS4_OPEN_DELEGATE_WRITE) {
+		open->op_delegate_type = NFS4_OPEN_DELEGATE_NONE_EXT;
+		open->op_why_no_deleg = WND4_NOT_SUPP_DOWNGRADE;
+	} else if (open->op_deleg_want == NFS4_SHARE_WANT_WRITE_DELEG &&
+		   dp->dl_type == NFS4_OPEN_DELEGATE_WRITE) {
+		open->op_delegate_type = NFS4_OPEN_DELEGATE_NONE_EXT;
+		open->op_why_no_deleg = WND4_NOT_SUPP_UPGRADE;
+	}
+	/* Otherwise the client must be confused wanting a delegation
+	 * it already has, therefore we don't return
+	 * NFS4_OPEN_DELEGATE_NONE_EXT and reason.
+	 */
+}
+
+__be32
+nfsd4_process_open2(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nfsd4_open *open)
+{
+	struct nfsd4_compoundres *resp = rqstp->rq_resp;
+	struct nfs4_client *cl = open->op_openowner->oo_owner.so_client;
+	struct nfs4_file *fp = NULL;
+	struct nfs4_ol_stateid *stp = NULL;
+	struct nfs4_delegation *dp = NULL;
+	__be32 status;
+	bool new_stp = false;
+
+	/*
+	 * Lookup file; if found, lookup stateid and check open request,
+	 * and check for delegations in the process of being recalled.
+	 * If not found, create the nfs4_file struct
+	 */
+	fp = find_or_add_file(open->op_file, &current_fh->fh_handle);
+	if (fp != open->op_file) {
+		status = nfs4_check_deleg(cl, open, &dp);
+		if (status)
+			goto out;
+		stp = nfsd4_find_and_lock_existing_open(fp, open);
+	} else {
+		open->op_file = NULL;
+		status = nfserr_bad_stateid;
+		if (nfsd4_is_deleg_cur(open))
+			goto out;
+	}
+
+	if (!stp) {
+		stp = init_open_stateid(fp, open);
+		if (!open->op_stp)
+			new_stp = true;
+	}
+
+	/*
+	 * OPEN the file, or upgrade an existing OPEN.
+	 * If truncate fails, the OPEN fails.
+	 *
+	 * stp is already locked.
+	 */
+	if (!new_stp) {
+		/* Stateid was found, this is an OPEN upgrade */
+		status = nfs4_upgrade_open(rqstp, fp, current_fh, stp, open);
+		if (status) {
+			mutex_unlock(&stp->st_mutex);
+			goto out;
+		}
+	} else {
+		status = nfs4_get_vfs_file(rqstp, fp, current_fh, stp, open);
+		if (status) {
+			stp->st_stid.sc_type = NFS4_CLOSED_STID;
+			release_open_stateid(stp);
+			mutex_unlock(&stp->st_mutex);
+			goto out;
+		}
+
+		stp->st_clnt_odstate = find_or_hash_clnt_odstate(fp,
+							open->op_odstate);
+		if (stp->st_clnt_odstate == open->op_odstate)
+			open->op_odstate = NULL;
+	}
+
+	nfs4_inc_and_copy_stateid(&open->op_stateid, &stp->st_stid);
+	mutex_unlock(&stp->st_mutex);
+
+	if (nfsd4_has_session(&resp->cstate)) {
+		if (open->op_deleg_want & NFS4_SHARE_WANT_NO_DELEG) {
+			open->op_delegate_type = NFS4_OPEN_DELEGATE_NONE_EXT;
+			open->op_why_no_deleg = WND4_NOT_WANTED;
+			goto nodeleg;
+		}
+	}
+
+	/*
+	* Attempt to hand out a delegation. No error return, because the
+	* OPEN succeeds even if we fail.
+	*/
+	nfs4_open_delegation(current_fh, open, stp);
+nodeleg:
+	status = nfs_ok;
+	trace_nfsd_open(&stp->st_stid.sc_stateid);
+out:
+	/* 4.1 client trying to upgrade/downgrade delegation? */
+	if (open->op_delegate_type == NFS4_OPEN_DELEGATE_NONE && dp &&
+	    open->op_deleg_want)
+		nfsd4_deleg_xgrade_none_ext(open, dp);
+
+	if (fp)
+		put_nfs4_file(fp);
+	if (status == 0 && open->op_claim_type == NFS4_OPEN_CLAIM_PREVIOUS)
+		open->op_openowner->oo_flags |= NFS4_OO_CONFIRMED;
+	/*
+	* To finish the open response, we just need to set the rflags.
+	*/
+	open->op_rflags = NFS4_OPEN_RESULT_LOCKTYPE_POSIX;
+	if (nfsd4_has_session(&resp->cstate))
+		open->op_rflags |= NFS4_OPEN_RESULT_MAY_NOTIFY_LOCK;
+	else if (!(open->op_openowner->oo_flags & NFS4_OO_CONFIRMED))
+		open->op_rflags |= NFS4_OPEN_RESULT_CONFIRM;
+
+	if (dp)
+		nfs4_put_stid(&dp->dl_stid);
+	if (stp)
+		nfs4_put_stid(&stp->st_stid);
+
+	return status;
+}
+
+void nfsd4_cleanup_open_state(struct nfsd4_compound_state *cstate,
+			      struct nfsd4_open *open)
+{
+	if (open->op_openowner) {
+		struct nfs4_stateowner *so = &open->op_openowner->oo_owner;
+
+		nfsd4_cstate_assign_replay(cstate, so);
+		nfs4_put_stateowner(so);
+	}
+	if (open->op_file)
+		kmem_cache_free(file_slab, open->op_file);
+	if (open->op_stp)
+		nfs4_put_stid(&open->op_stp->st_stid);
+	if (open->op_odstate)
+		kmem_cache_free(odstate_slab, open->op_odstate);
+}
+
+__be32
+nfsd4_renew(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+	    union nfsd4_op_u *u)
+{
+	clientid_t *clid = &u->renew;
+	struct nfs4_client *clp;
+	__be32 status;
+	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+
+	trace_nfsd_clid_renew(clid);
+	status = lookup_clientid(clid, cstate, nn, false);
+	if (status)
+		goto out;
+	clp = cstate->clp;
+	status = nfserr_cb_path_down;
+	if (!list_empty(&clp->cl_delegations)
+			&& clp->cl_cb_state != NFSD4_CB_UP)
+		goto out;
+	status = nfs_ok;
+out:
+	return status;
+}
+
+void
+nfsd4_end_grace(struct nfsd_net *nn)
+{
+	/* do nothing if grace period already ended */
+	if (nn->grace_ended)
+		return;
+
+	trace_nfsd_grace_complete(nn);
+	nn->grace_ended = true;
+	/*
+	 * If the server goes down again right now, an NFSv4
+	 * client will still be allowed to reclaim after it comes back up,
+	 * even if it hasn't yet had a chance to reclaim state this time.
+	 *
+	 */
+	nfsd4_record_grace_done(nn);
+	/*
+	 * At this point, NFSv4 clients can still reclaim.  But if the
+	 * server crashes, any that have not yet reclaimed will be out
+	 * of luck on the next boot.
+	 *
+	 * (NFSv4.1+ clients are considered to have reclaimed once they
+	 * call RECLAIM_COMPLETE.  NFSv4.0 clients are considered to
+	 * have reclaimed after their first OPEN.)
+	 */
+	locks_end_grace(&nn->nfsd4_manager);
+	/*
+	 * At this point, and once lockd and/or any other containers
+	 * exit their grace period, further reclaims will fail and
+	 * regular locking can resume.
+	 */
+}
+
+/*
+ * If we've waited a lease period but there are still clients trying to
+ * reclaim, wait a little longer to give them a chance to finish.
+ */
+static bool clients_still_reclaiming(struct nfsd_net *nn)
+{
+	time64_t double_grace_period_end = nn->boot_time +
+					   2 * nn->nfsd4_lease;
+
+	if (nn->track_reclaim_completes &&
+			atomic_read(&nn->nr_reclaim_complete) ==
+			nn->reclaim_str_hashtbl_size)
+		return false;
+	if (!nn->somebody_reclaimed)
+		return false;
+	nn->somebody_reclaimed = false;
+	/*
+	 * If we've given them *two* lease times to reclaim, and they're
+	 * still not done, give up:
+	 */
+	if (ktime_get_boottime_seconds() > double_grace_period_end)
+		return false;
+	return true;
+}
+
+static time64_t
+nfs4_laundromat(struct nfsd_net *nn)
+{
+	struct nfs4_client *clp;
+	struct nfs4_openowner *oo;
+	struct nfs4_delegation *dp;
+	struct nfs4_ol_stateid *stp;
+	struct nfsd4_blocked_lock *nbl;
+	struct list_head *pos, *next, reaplist;
+	time64_t cutoff = ktime_get_boottime_seconds() - nn->nfsd4_lease;
+	time64_t t, new_timeo = nn->nfsd4_lease;
+	struct nfs4_cpntf_state *cps;
+	copy_stateid_t *cps_t;
+	int i;
+
+	if (clients_still_reclaiming(nn)) {
+		new_timeo = 0;
+		goto out;
+	}
+	nfsd4_end_grace(nn);
+	INIT_LIST_HEAD(&reaplist);
+
+	spin_lock(&nn->s2s_cp_lock);
+	idr_for_each_entry(&nn->s2s_cp_stateids, cps_t, i) {
+		cps = container_of(cps_t, struct nfs4_cpntf_state, cp_stateid);
+		if (cps->cp_stateid.sc_type == NFS4_COPYNOTIFY_STID &&
+				cps->cpntf_time < cutoff)
+			_free_cpntf_state_locked(nn, cps);
+	}
+	spin_unlock(&nn->s2s_cp_lock);
+
+	spin_lock(&nn->client_lock);
+	list_for_each_safe(pos, next, &nn->client_lru) {
+		clp = list_entry(pos, struct nfs4_client, cl_lru);
+		if (clp->cl_time > cutoff) {
+			t = clp->cl_time - cutoff;
+			new_timeo = min(new_timeo, t);
+			break;
+		}
+		if (mark_client_expired_locked(clp)) {
+			trace_nfsd_clid_expired(&clp->cl_clientid);
+			continue;
+		}
+		list_add(&clp->cl_lru, &reaplist);
+	}
+	spin_unlock(&nn->client_lock);
+	list_for_each_safe(pos, next, &reaplist) {
+		clp = list_entry(pos, struct nfs4_client, cl_lru);
+		trace_nfsd_clid_purged(&clp->cl_clientid);
+		list_del_init(&clp->cl_lru);
+		expire_client(clp);
+	}
+	spin_lock(&state_lock);
+	list_for_each_safe(pos, next, &nn->del_recall_lru) {
+		dp = list_entry (pos, struct nfs4_delegation, dl_recall_lru);
+		if (dp->dl_time > cutoff) {
+			t = dp->dl_time - cutoff;
+			new_timeo = min(new_timeo, t);
+			break;
+		}
+		WARN_ON(!unhash_delegation_locked(dp));
+		list_add(&dp->dl_recall_lru, &reaplist);
+	}
+	spin_unlock(&state_lock);
+	while (!list_empty(&reaplist)) {
+		dp = list_first_entry(&reaplist, struct nfs4_delegation,
+					dl_recall_lru);
+		list_del_init(&dp->dl_recall_lru);
+		revoke_delegation(dp);
+	}
+
+	spin_lock(&nn->client_lock);
+	while (!list_empty(&nn->close_lru)) {
+		oo = list_first_entry(&nn->close_lru, struct nfs4_openowner,
+					oo_close_lru);
+		if (oo->oo_time > cutoff) {
+			t = oo->oo_time - cutoff;
+			new_timeo = min(new_timeo, t);
+			break;
+		}
+		list_del_init(&oo->oo_close_lru);
+		stp = oo->oo_last_closed_stid;
+		oo->oo_last_closed_stid = NULL;
+		spin_unlock(&nn->client_lock);
+		nfs4_put_stid(&stp->st_stid);
+		spin_lock(&nn->client_lock);
+	}
+	spin_unlock(&nn->client_lock);
+
+	/*
+	 * It's possible for a client to try and acquire an already held lock
+	 * that is being held for a long time, and then lose interest in it.
+	 * So, we clean out any un-revisited request after a lease period
+	 * under the assumption that the client is no longer interested.
+	 *
+	 * RFC5661, sec. 9.6 states that the client must not rely on getting
+	 * notifications and must continue to poll for locks, even when the
+	 * server supports them. Thus this shouldn't lead to clients blocking
+	 * indefinitely once the lock does become free.
+	 */
+	BUG_ON(!list_empty(&reaplist));
+	spin_lock(&nn->blocked_locks_lock);
+	while (!list_empty(&nn->blocked_locks_lru)) {
+		nbl = list_first_entry(&nn->blocked_locks_lru,
+					struct nfsd4_blocked_lock, nbl_lru);
+		if (nbl->nbl_time > cutoff) {
+			t = nbl->nbl_time - cutoff;
+			new_timeo = min(new_timeo, t);
+			break;
+		}
+		list_move(&nbl->nbl_lru, &reaplist);
+		list_del_init(&nbl->nbl_list);
+	}
+	spin_unlock(&nn->blocked_locks_lock);
+
+	while (!list_empty(&reaplist)) {
+		nbl = list_first_entry(&reaplist,
+					struct nfsd4_blocked_lock, nbl_lru);
+		list_del_init(&nbl->nbl_lru);
+		free_blocked_lock(nbl);
+	}
+out:
+	new_timeo = max_t(time64_t, new_timeo, NFSD_LAUNDROMAT_MINTIMEOUT);
+	return new_timeo;
+}
+
+static struct workqueue_struct *laundry_wq;
+static void laundromat_main(struct work_struct *);
+
+static void
+laundromat_main(struct work_struct *laundry)
+{
+	time64_t t;
+	struct delayed_work *dwork = to_delayed_work(laundry);
+	struct nfsd_net *nn = container_of(dwork, struct nfsd_net,
+					   laundromat_work);
+
+	t = nfs4_laundromat(nn);
+	queue_delayed_work(laundry_wq, &nn->laundromat_work, t*HZ);
+}
+
+static inline __be32 nfs4_check_fh(struct svc_fh *fhp, struct nfs4_stid *stp)
+{
+	if (!fh_match(&fhp->fh_handle, &stp->sc_file->fi_fhandle))
+		return nfserr_bad_stateid;
+	return nfs_ok;
+}
+
+static inline int
+access_permit_read(struct nfs4_ol_stateid *stp)
+{
+	return test_access(NFS4_SHARE_ACCESS_READ, stp) ||
+		test_access(NFS4_SHARE_ACCESS_BOTH, stp) ||
+		test_access(NFS4_SHARE_ACCESS_WRITE, stp);
+}
+
+static inline int
+access_permit_write(struct nfs4_ol_stateid *stp)
+{
+	return test_access(NFS4_SHARE_ACCESS_WRITE, stp) ||
+		test_access(NFS4_SHARE_ACCESS_BOTH, stp);
+}
+
+static
+__be32 nfs4_check_openmode(struct nfs4_ol_stateid *stp, int flags)
+{
+        __be32 status = nfserr_openmode;
+
+	/* For lock stateid's, we test the parent open, not the lock: */
+	if (stp->st_openstp)
+		stp = stp->st_openstp;
+	if ((flags & WR_STATE) && !access_permit_write(stp))
+                goto out;
+	if ((flags & RD_STATE) && !access_permit_read(stp))
+                goto out;
+	status = nfs_ok;
+out:
+	return status;
+}
+
+static inline __be32
+check_special_stateids(struct net *net, svc_fh *current_fh, stateid_t *stateid, int flags)
+{
+	if (ONE_STATEID(stateid) && (flags & RD_STATE))
+		return nfs_ok;
+	else if (opens_in_grace(net)) {
+		/* Answer in remaining cases depends on existence of
+		 * conflicting state; so we must wait out the grace period. */
+		return nfserr_grace;
+	} else if (flags & WR_STATE)
+		return nfs4_share_conflict(current_fh,
+				NFS4_SHARE_DENY_WRITE);
+	else /* (flags & RD_STATE) && ZERO_STATEID(stateid) */
+		return nfs4_share_conflict(current_fh,
+				NFS4_SHARE_DENY_READ);
+}
+
+/*
+ * Allow READ/WRITE during grace period on recovered state only for files
+ * that are not able to provide mandatory locking.
+ */
+static inline int
+grace_disallows_io(struct net *net, struct inode *inode)
+{
+	return opens_in_grace(net) && mandatory_lock(inode);
+}
+
+static __be32 check_stateid_generation(stateid_t *in, stateid_t *ref, bool has_session)
+{
+	/*
+	 * When sessions are used the stateid generation number is ignored
+	 * when it is zero.
+	 */
+	if (has_session && in->si_generation == 0)
+		return nfs_ok;
+
+	if (in->si_generation == ref->si_generation)
+		return nfs_ok;
+
+	/* If the client sends us a stateid from the future, it's buggy: */
+	if (nfsd4_stateid_generation_after(in, ref))
+		return nfserr_bad_stateid;
+	/*
+	 * However, we could see a stateid from the past, even from a
+	 * non-buggy client.  For example, if the client sends a lock
+	 * while some IO is outstanding, the lock may bump si_generation
+	 * while the IO is still in flight.  The client could avoid that
+	 * situation by waiting for responses on all the IO requests,
+	 * but better performance may result in retrying IO that
+	 * receives an old_stateid error if requests are rarely
+	 * reordered in flight:
+	 */
+	return nfserr_old_stateid;
+}
+
+static __be32 nfsd4_stid_check_stateid_generation(stateid_t *in, struct nfs4_stid *s, bool has_session)
+{
+	__be32 ret;
+
+	spin_lock(&s->sc_lock);
+	ret = nfsd4_verify_open_stid(s);
+	if (ret == nfs_ok)
+		ret = check_stateid_generation(in, &s->sc_stateid, has_session);
+	spin_unlock(&s->sc_lock);
+	return ret;
+}
+
+static __be32 nfsd4_check_openowner_confirmed(struct nfs4_ol_stateid *ols)
+{
+	if (ols->st_stateowner->so_is_open_owner &&
+	    !(openowner(ols->st_stateowner)->oo_flags & NFS4_OO_CONFIRMED))
+		return nfserr_bad_stateid;
+	return nfs_ok;
+}
+
+static __be32 nfsd4_validate_stateid(struct nfs4_client *cl, stateid_t *stateid)
+{
+	struct nfs4_stid *s;
+	__be32 status = nfserr_bad_stateid;
+
+	if (ZERO_STATEID(stateid) || ONE_STATEID(stateid) ||
+		CLOSE_STATEID(stateid))
+		return status;
+	spin_lock(&cl->cl_lock);
+	s = find_stateid_locked(cl, stateid);
+	if (!s)
+		goto out_unlock;
+	status = nfsd4_stid_check_stateid_generation(stateid, s, 1);
+	if (status)
+		goto out_unlock;
+	switch (s->sc_type) {
+	case NFS4_DELEG_STID:
+		status = nfs_ok;
+		break;
+	case NFS4_REVOKED_DELEG_STID:
+		status = nfserr_deleg_revoked;
+		break;
+	case NFS4_OPEN_STID:
+	case NFS4_LOCK_STID:
+		status = nfsd4_check_openowner_confirmed(openlockstateid(s));
+		break;
+	default:
+		printk("unknown stateid type %x\n", s->sc_type);
+		fallthrough;
+	case NFS4_CLOSED_STID:
+	case NFS4_CLOSED_DELEG_STID:
+		status = nfserr_bad_stateid;
+	}
+out_unlock:
+	spin_unlock(&cl->cl_lock);
+	return status;
+}
+
+__be32
+nfsd4_lookup_stateid(struct nfsd4_compound_state *cstate,
+		     stateid_t *stateid, unsigned char typemask,
+		     struct nfs4_stid **s, struct nfsd_net *nn)
+{
+	__be32 status;
+	bool return_revoked = false;
+
+	/*
+	 *  only return revoked delegations if explicitly asked.
+	 *  otherwise we report revoked or bad_stateid status.
+	 */
+	if (typemask & NFS4_REVOKED_DELEG_STID)
+		return_revoked = true;
+	else if (typemask & NFS4_DELEG_STID)
+		typemask |= NFS4_REVOKED_DELEG_STID;
+
+	if (ZERO_STATEID(stateid) || ONE_STATEID(stateid) ||
+		CLOSE_STATEID(stateid))
+		return nfserr_bad_stateid;
+	status = lookup_clientid(&stateid->si_opaque.so_clid, cstate, nn,
+				 false);
+	if (status == nfserr_stale_clientid) {
+		if (cstate->session)
+			return nfserr_bad_stateid;
+		return nfserr_stale_stateid;
+	}
+	if (status)
+		return status;
+	*s = find_stateid_by_type(cstate->clp, stateid, typemask);
+	if (!*s)
+		return nfserr_bad_stateid;
+	if (((*s)->sc_type == NFS4_REVOKED_DELEG_STID) && !return_revoked) {
+		nfs4_put_stid(*s);
+		if (cstate->minorversion)
+			return nfserr_deleg_revoked;
+		return nfserr_bad_stateid;
+	}
+	return nfs_ok;
+}
+
+static struct nfsd_file *
+nfs4_find_file(struct nfs4_stid *s, int flags)
+{
+	if (!s)
+		return NULL;
+
+	switch (s->sc_type) {
+	case NFS4_DELEG_STID:
+		if (WARN_ON_ONCE(!s->sc_file->fi_deleg_file))
+			return NULL;
+		return nfsd_file_get(s->sc_file->fi_deleg_file);
+	case NFS4_OPEN_STID:
+	case NFS4_LOCK_STID:
+		if (flags & RD_STATE)
+			return find_readable_file(s->sc_file);
+		else
+			return find_writeable_file(s->sc_file);
+	}
+
+	return NULL;
+}
+
+static __be32
+nfs4_check_olstateid(struct nfs4_ol_stateid *ols, int flags)
+{
+	__be32 status;
+
+	status = nfsd4_check_openowner_confirmed(ols);
+	if (status)
+		return status;
+	return nfs4_check_openmode(ols, flags);
+}
+
+static __be32
+nfs4_check_file(struct svc_rqst *rqstp, struct svc_fh *fhp, struct nfs4_stid *s,
+		struct nfsd_file **nfp, int flags)
+{
+	int acc = (flags & RD_STATE) ? NFSD_MAY_READ : NFSD_MAY_WRITE;
+	struct nfsd_file *nf;
+	__be32 status;
+
+	nf = nfs4_find_file(s, flags);
+	if (nf) {
+		status = nfsd_permission(rqstp, fhp->fh_export, fhp->fh_dentry,
+				acc | NFSD_MAY_OWNER_OVERRIDE);
+		if (status) {
+			nfsd_file_put(nf);
+			goto out;
+		}
+	} else {
+		status = nfsd_file_acquire(rqstp, fhp, acc, &nf);
+		if (status)
+			return status;
+	}
+	*nfp = nf;
+out:
+	return status;
+}
+static void
+_free_cpntf_state_locked(struct nfsd_net *nn, struct nfs4_cpntf_state *cps)
+{
+	WARN_ON_ONCE(cps->cp_stateid.sc_type != NFS4_COPYNOTIFY_STID);
+	if (!refcount_dec_and_test(&cps->cp_stateid.sc_count))
+		return;
+	list_del(&cps->cp_list);
+	idr_remove(&nn->s2s_cp_stateids,
+		   cps->cp_stateid.stid.si_opaque.so_id);
+	kfree(cps);
+}
+/*
+ * A READ from an inter server to server COPY will have a
+ * copy stateid. Look up the copy notify stateid from the
+ * idr structure and take a reference on it.
+ */
+__be32 manage_cpntf_state(struct nfsd_net *nn, stateid_t *st,
+			  struct nfs4_client *clp,
+			  struct nfs4_cpntf_state **cps)
+{
+	copy_stateid_t *cps_t;
+	struct nfs4_cpntf_state *state = NULL;
+
+	if (st->si_opaque.so_clid.cl_id != nn->s2s_cp_cl_id)
+		return nfserr_bad_stateid;
+	spin_lock(&nn->s2s_cp_lock);
+	cps_t = idr_find(&nn->s2s_cp_stateids, st->si_opaque.so_id);
+	if (cps_t) {
+		state = container_of(cps_t, struct nfs4_cpntf_state,
+				     cp_stateid);
+		if (state->cp_stateid.sc_type != NFS4_COPYNOTIFY_STID) {
+			state = NULL;
+			goto unlock;
+		}
+		if (!clp)
+			refcount_inc(&state->cp_stateid.sc_count);
+		else
+			_free_cpntf_state_locked(nn, state);
+	}
+unlock:
+	spin_unlock(&nn->s2s_cp_lock);
+	if (!state)
+		return nfserr_bad_stateid;
+	if (!clp && state)
+		*cps = state;
+	return 0;
+}
+
+static __be32 find_cpntf_state(struct nfsd_net *nn, stateid_t *st,
+			       struct nfs4_stid **stid)
+{
+	__be32 status;
+	struct nfs4_cpntf_state *cps = NULL;
+	struct nfsd4_compound_state cstate;
+
+	status = manage_cpntf_state(nn, st, NULL, &cps);
+	if (status)
+		return status;
+
+	cps->cpntf_time = ktime_get_boottime_seconds();
+	memset(&cstate, 0, sizeof(cstate));
+	status = lookup_clientid(&cps->cp_p_clid, &cstate, nn, true);
+	if (status)
+		goto out;
+	status = nfsd4_lookup_stateid(&cstate, &cps->cp_p_stateid,
+				NFS4_DELEG_STID|NFS4_OPEN_STID|NFS4_LOCK_STID,
+				stid, nn);
+	put_client_renew(cstate.clp);
+out:
+	nfs4_put_cpntf_state(nn, cps);
+	return status;
+}
+
+void nfs4_put_cpntf_state(struct nfsd_net *nn, struct nfs4_cpntf_state *cps)
+{
+	spin_lock(&nn->s2s_cp_lock);
+	_free_cpntf_state_locked(nn, cps);
+	spin_unlock(&nn->s2s_cp_lock);
+}
+
+/*
+ * Checks for stateid operations
+ */
+__be32
+nfs4_preprocess_stateid_op(struct svc_rqst *rqstp,
+		struct nfsd4_compound_state *cstate, struct svc_fh *fhp,
+		stateid_t *stateid, int flags, struct nfsd_file **nfp,
+		struct nfs4_stid **cstid)
+{
+	struct inode *ino = d_inode(fhp->fh_dentry);
+	struct net *net = SVC_NET(rqstp);
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+	struct nfs4_stid *s = NULL;
+	__be32 status;
+
+	if (nfp)
+		*nfp = NULL;
+
+	if (grace_disallows_io(net, ino))
+		return nfserr_grace;
+
+	if (ZERO_STATEID(stateid) || ONE_STATEID(stateid)) {
+		status = check_special_stateids(net, fhp, stateid, flags);
+		goto done;
+	}
+
+	status = nfsd4_lookup_stateid(cstate, stateid,
+				NFS4_DELEG_STID|NFS4_OPEN_STID|NFS4_LOCK_STID,
+				&s, nn);
+	if (status == nfserr_bad_stateid)
+		status = find_cpntf_state(nn, stateid, &s);
+	if (status)
+		return status;
+	status = nfsd4_stid_check_stateid_generation(stateid, s,
+			nfsd4_has_session(cstate));
+	if (status)
+		goto out;
+
+	switch (s->sc_type) {
+	case NFS4_DELEG_STID:
+		status = nfs4_check_delegmode(delegstateid(s), flags);
+		break;
+	case NFS4_OPEN_STID:
+	case NFS4_LOCK_STID:
+		status = nfs4_check_olstateid(openlockstateid(s), flags);
+		break;
+	default:
+		status = nfserr_bad_stateid;
+		break;
+	}
+	if (status)
+		goto out;
+	status = nfs4_check_fh(fhp, s);
+
+done:
+	if (status == nfs_ok && nfp)
+		status = nfs4_check_file(rqstp, fhp, s, nfp, flags);
+out:
+	if (s) {
+		if (!status && cstid)
+			*cstid = s;
+		else
+			nfs4_put_stid(s);
+	}
+	return status;
+}
+
+/*
+ * Test if the stateid is valid
+ */
+__be32
+nfsd4_test_stateid(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+		   union nfsd4_op_u *u)
+{
+	struct nfsd4_test_stateid *test_stateid = &u->test_stateid;
+	struct nfsd4_test_stateid_id *stateid;
+	struct nfs4_client *cl = cstate->session->se_client;
+
+	list_for_each_entry(stateid, &test_stateid->ts_stateid_list, ts_id_list)
+		stateid->ts_id_status =
+			nfsd4_validate_stateid(cl, &stateid->ts_id_stateid);
+
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_free_lock_stateid(stateid_t *stateid, struct nfs4_stid *s)
+{
+	struct nfs4_ol_stateid *stp = openlockstateid(s);
+	__be32 ret;
+
+	ret = nfsd4_lock_ol_stateid(stp);
+	if (ret)
+		goto out_put_stid;
+
+	ret = check_stateid_generation(stateid, &s->sc_stateid, 1);
+	if (ret)
+		goto out;
+
+	ret = nfserr_locks_held;
+	if (check_for_locks(stp->st_stid.sc_file,
+			    lockowner(stp->st_stateowner)))
+		goto out;
+
+	release_lock_stateid(stp);
+	ret = nfs_ok;
+
+out:
+	mutex_unlock(&stp->st_mutex);
+out_put_stid:
+	nfs4_put_stid(s);
+	return ret;
+}
+
+__be32
+nfsd4_free_stateid(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+		   union nfsd4_op_u *u)
+{
+	struct nfsd4_free_stateid *free_stateid = &u->free_stateid;
+	stateid_t *stateid = &free_stateid->fr_stateid;
+	struct nfs4_stid *s;
+	struct nfs4_delegation *dp;
+	struct nfs4_client *cl = cstate->session->se_client;
+	__be32 ret = nfserr_bad_stateid;
+
+	spin_lock(&cl->cl_lock);
+	s = find_stateid_locked(cl, stateid);
+	if (!s)
+		goto out_unlock;
+	spin_lock(&s->sc_lock);
+	switch (s->sc_type) {
+	case NFS4_DELEG_STID:
+		ret = nfserr_locks_held;
+		break;
+	case NFS4_OPEN_STID:
+		ret = check_stateid_generation(stateid, &s->sc_stateid, 1);
+		if (ret)
+			break;
+		ret = nfserr_locks_held;
+		break;
+	case NFS4_LOCK_STID:
+		spin_unlock(&s->sc_lock);
+		refcount_inc(&s->sc_count);
+		spin_unlock(&cl->cl_lock);
+		ret = nfsd4_free_lock_stateid(stateid, s);
+		goto out;
+	case NFS4_REVOKED_DELEG_STID:
+		spin_unlock(&s->sc_lock);
+		dp = delegstateid(s);
+		list_del_init(&dp->dl_recall_lru);
+		spin_unlock(&cl->cl_lock);
+		nfs4_put_stid(s);
+		ret = nfs_ok;
+		goto out;
+	/* Default falls through and returns nfserr_bad_stateid */
+	}
+	spin_unlock(&s->sc_lock);
+out_unlock:
+	spin_unlock(&cl->cl_lock);
+out:
+	return ret;
+}
+
+static inline int
+setlkflg (int type)
+{
+	return (type == NFS4_READW_LT || type == NFS4_READ_LT) ?
+		RD_STATE : WR_STATE;
+}
+
+static __be32 nfs4_seqid_op_checks(struct nfsd4_compound_state *cstate, stateid_t *stateid, u32 seqid, struct nfs4_ol_stateid *stp)
+{
+	struct svc_fh *current_fh = &cstate->current_fh;
+	struct nfs4_stateowner *sop = stp->st_stateowner;
+	__be32 status;
+
+	status = nfsd4_check_seqid(cstate, sop, seqid);
+	if (status)
+		return status;
+	status = nfsd4_lock_ol_stateid(stp);
+	if (status != nfs_ok)
+		return status;
+	status = check_stateid_generation(stateid, &stp->st_stid.sc_stateid, nfsd4_has_session(cstate));
+	if (status == nfs_ok)
+		status = nfs4_check_fh(current_fh, &stp->st_stid);
+	if (status != nfs_ok)
+		mutex_unlock(&stp->st_mutex);
+	return status;
+}
+
+/* 
+ * Checks for sequence id mutating operations. 
+ */
+static __be32
+nfs4_preprocess_seqid_op(struct nfsd4_compound_state *cstate, u32 seqid,
+			 stateid_t *stateid, char typemask,
+			 struct nfs4_ol_stateid **stpp,
+			 struct nfsd_net *nn)
+{
+	__be32 status;
+	struct nfs4_stid *s;
+	struct nfs4_ol_stateid *stp = NULL;
+
+	trace_nfsd_preprocess(seqid, stateid);
+
+	*stpp = NULL;
+	status = nfsd4_lookup_stateid(cstate, stateid, typemask, &s, nn);
+	if (status)
+		return status;
+	stp = openlockstateid(s);
+	nfsd4_cstate_assign_replay(cstate, stp->st_stateowner);
+
+	status = nfs4_seqid_op_checks(cstate, stateid, seqid, stp);
+	if (!status)
+		*stpp = stp;
+	else
+		nfs4_put_stid(&stp->st_stid);
+	return status;
+}
+
+static __be32 nfs4_preprocess_confirmed_seqid_op(struct nfsd4_compound_state *cstate, u32 seqid,
+						 stateid_t *stateid, struct nfs4_ol_stateid **stpp, struct nfsd_net *nn)
+{
+	__be32 status;
+	struct nfs4_openowner *oo;
+	struct nfs4_ol_stateid *stp;
+
+	status = nfs4_preprocess_seqid_op(cstate, seqid, stateid,
+						NFS4_OPEN_STID, &stp, nn);
+	if (status)
+		return status;
+	oo = openowner(stp->st_stateowner);
+	if (!(oo->oo_flags & NFS4_OO_CONFIRMED)) {
+		mutex_unlock(&stp->st_mutex);
+		nfs4_put_stid(&stp->st_stid);
+		return nfserr_bad_stateid;
+	}
+	*stpp = stp;
+	return nfs_ok;
+}
+
+__be32
+nfsd4_open_confirm(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+		   union nfsd4_op_u *u)
+{
+	struct nfsd4_open_confirm *oc = &u->open_confirm;
+	__be32 status;
+	struct nfs4_openowner *oo;
+	struct nfs4_ol_stateid *stp;
+	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+
+	dprintk("NFSD: nfsd4_open_confirm on file %pd\n",
+			cstate->current_fh.fh_dentry);
+
+	status = fh_verify(rqstp, &cstate->current_fh, S_IFREG, 0);
+	if (status)
+		return status;
+
+	status = nfs4_preprocess_seqid_op(cstate,
+					oc->oc_seqid, &oc->oc_req_stateid,
+					NFS4_OPEN_STID, &stp, nn);
+	if (status)
+		goto out;
+	oo = openowner(stp->st_stateowner);
+	status = nfserr_bad_stateid;
+	if (oo->oo_flags & NFS4_OO_CONFIRMED) {
+		mutex_unlock(&stp->st_mutex);
+		goto put_stateid;
+	}
+	oo->oo_flags |= NFS4_OO_CONFIRMED;
+	nfs4_inc_and_copy_stateid(&oc->oc_resp_stateid, &stp->st_stid);
+	mutex_unlock(&stp->st_mutex);
+	trace_nfsd_open_confirm(oc->oc_seqid, &stp->st_stid.sc_stateid);
+	nfsd4_client_record_create(oo->oo_owner.so_client);
+	status = nfs_ok;
+put_stateid:
+	nfs4_put_stid(&stp->st_stid);
+out:
+	nfsd4_bump_seqid(cstate, status);
+	return status;
+}
+
+static inline void nfs4_stateid_downgrade_bit(struct nfs4_ol_stateid *stp, u32 access)
+{
+	if (!test_access(access, stp))
+		return;
+	nfs4_file_put_access(stp->st_stid.sc_file, access);
+	clear_access(access, stp);
+}
+
+static inline void nfs4_stateid_downgrade(struct nfs4_ol_stateid *stp, u32 to_access)
+{
+	switch (to_access) {
+	case NFS4_SHARE_ACCESS_READ:
+		nfs4_stateid_downgrade_bit(stp, NFS4_SHARE_ACCESS_WRITE);
+		nfs4_stateid_downgrade_bit(stp, NFS4_SHARE_ACCESS_BOTH);
+		break;
+	case NFS4_SHARE_ACCESS_WRITE:
+		nfs4_stateid_downgrade_bit(stp, NFS4_SHARE_ACCESS_READ);
+		nfs4_stateid_downgrade_bit(stp, NFS4_SHARE_ACCESS_BOTH);
+		break;
+	case NFS4_SHARE_ACCESS_BOTH:
+		break;
+	default:
+		WARN_ON_ONCE(1);
+	}
+}
+
+__be32
+nfsd4_open_downgrade(struct svc_rqst *rqstp,
+		     struct nfsd4_compound_state *cstate, union nfsd4_op_u *u)
+{
+	struct nfsd4_open_downgrade *od = &u->open_downgrade;
+	__be32 status;
+	struct nfs4_ol_stateid *stp;
+	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+
+	dprintk("NFSD: nfsd4_open_downgrade on file %pd\n", 
+			cstate->current_fh.fh_dentry);
+
+	/* We don't yet support WANT bits: */
+	if (od->od_deleg_want)
+		dprintk("NFSD: %s: od_deleg_want=0x%x ignored\n", __func__,
+			od->od_deleg_want);
+
+	status = nfs4_preprocess_confirmed_seqid_op(cstate, od->od_seqid,
+					&od->od_stateid, &stp, nn);
+	if (status)
+		goto out; 
+	status = nfserr_inval;
+	if (!test_access(od->od_share_access, stp)) {
+		dprintk("NFSD: access not a subset of current bitmap: 0x%hhx, input access=%08x\n",
+			stp->st_access_bmap, od->od_share_access);
+		goto put_stateid;
+	}
+	if (!test_deny(od->od_share_deny, stp)) {
+		dprintk("NFSD: deny not a subset of current bitmap: 0x%hhx, input deny=%08x\n",
+			stp->st_deny_bmap, od->od_share_deny);
+		goto put_stateid;
+	}
+	nfs4_stateid_downgrade(stp, od->od_share_access);
+	reset_union_bmap_deny(od->od_share_deny, stp);
+	nfs4_inc_and_copy_stateid(&od->od_stateid, &stp->st_stid);
+	status = nfs_ok;
+put_stateid:
+	mutex_unlock(&stp->st_mutex);
+	nfs4_put_stid(&stp->st_stid);
+out:
+	nfsd4_bump_seqid(cstate, status);
+	return status;
+}
+
+static void nfsd4_close_open_stateid(struct nfs4_ol_stateid *s)
+{
+	struct nfs4_client *clp = s->st_stid.sc_client;
+	bool unhashed;
+	LIST_HEAD(reaplist);
+	struct nfs4_ol_stateid *stp;
+
+	spin_lock(&clp->cl_lock);
+	unhashed = unhash_open_stateid(s, &reaplist);
+
+	if (clp->cl_minorversion) {
+		if (unhashed)
+			put_ol_stateid_locked(s, &reaplist);
+		spin_unlock(&clp->cl_lock);
+		list_for_each_entry(stp, &reaplist, st_locks)
+			nfs4_free_cpntf_statelist(clp->net, &stp->st_stid);
+		free_ol_stateid_reaplist(&reaplist);
+	} else {
+		spin_unlock(&clp->cl_lock);
+		free_ol_stateid_reaplist(&reaplist);
+		if (unhashed)
+			move_to_close_lru(s, clp->net);
+	}
+}
+
+/*
+ * nfs4_unlock_state() called after encode
+ */
+__be32
+nfsd4_close(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+		union nfsd4_op_u *u)
+{
+	struct nfsd4_close *close = &u->close;
+	__be32 status;
+	struct nfs4_ol_stateid *stp;
+	struct net *net = SVC_NET(rqstp);
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	dprintk("NFSD: nfsd4_close on file %pd\n", 
+			cstate->current_fh.fh_dentry);
+
+	status = nfs4_preprocess_seqid_op(cstate, close->cl_seqid,
+					&close->cl_stateid,
+					NFS4_OPEN_STID|NFS4_CLOSED_STID,
+					&stp, nn);
+	nfsd4_bump_seqid(cstate, status);
+	if (status)
+		goto out; 
+
+	stp->st_stid.sc_type = NFS4_CLOSED_STID;
+
+	/*
+	 * Technically we don't _really_ have to increment or copy it, since
+	 * it should just be gone after this operation and we clobber the
+	 * copied value below, but we continue to do so here just to ensure
+	 * that racing ops see that there was a state change.
+	 */
+	nfs4_inc_and_copy_stateid(&close->cl_stateid, &stp->st_stid);
+
+	nfsd4_close_open_stateid(stp);
+	mutex_unlock(&stp->st_mutex);
+
+	/* v4.1+ suggests that we send a special stateid in here, since the
+	 * clients should just ignore this anyway. Since this is not useful
+	 * for v4.0 clients either, we set it to the special close_stateid
+	 * universally.
+	 *
+	 * See RFC5661 section 18.2.4, and RFC7530 section 16.2.5
+	 */
+	memcpy(&close->cl_stateid, &close_stateid, sizeof(close->cl_stateid));
+
+	/* put reference from nfs4_preprocess_seqid_op */
+	nfs4_put_stid(&stp->st_stid);
+out:
+	return status;
+}
+
+__be32
+nfsd4_delegreturn(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+		  union nfsd4_op_u *u)
+{
+	struct nfsd4_delegreturn *dr = &u->delegreturn;
+	struct nfs4_delegation *dp;
+	stateid_t *stateid = &dr->dr_stateid;
+	struct nfs4_stid *s;
+	__be32 status;
+	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+
+	if ((status = fh_verify(rqstp, &cstate->current_fh, S_IFREG, 0)))
+		return status;
+
+	status = nfsd4_lookup_stateid(cstate, stateid, NFS4_DELEG_STID, &s, nn);
+	if (status)
+		goto out;
+	dp = delegstateid(s);
+	status = nfsd4_stid_check_stateid_generation(stateid, &dp->dl_stid, nfsd4_has_session(cstate));
+	if (status)
+		goto put_stateid;
+
+	destroy_delegation(dp);
+put_stateid:
+	nfs4_put_stid(&dp->dl_stid);
+out:
+	return status;
+}
+
+static inline u64
+end_offset(u64 start, u64 len)
+{
+	u64 end;
+
+	end = start + len;
+	return end >= start ? end: NFS4_MAX_UINT64;
+}
+
+/* last octet in a range */
+static inline u64
+last_byte_offset(u64 start, u64 len)
+{
+	u64 end;
+
+	WARN_ON_ONCE(!len);
+	end = start + len;
+	return end > start ? end - 1: NFS4_MAX_UINT64;
+}
+
+/*
+ * TODO: Linux file offsets are _signed_ 64-bit quantities, which means that
+ * we can't properly handle lock requests that go beyond the (2^63 - 1)-th
+ * byte, because of sign extension problems.  Since NFSv4 calls for 64-bit
+ * locking, this prevents us from being completely protocol-compliant.  The
+ * real solution to this problem is to start using unsigned file offsets in
+ * the VFS, but this is a very deep change!
+ */
+static inline void
+nfs4_transform_lock_offset(struct file_lock *lock)
+{
+	if (lock->fl_start < 0)
+		lock->fl_start = OFFSET_MAX;
+	if (lock->fl_end < 0)
+		lock->fl_end = OFFSET_MAX;
+}
+
+static fl_owner_t
+nfsd4_fl_get_owner(fl_owner_t owner)
+{
+	struct nfs4_lockowner *lo = (struct nfs4_lockowner *)owner;
+
+	nfs4_get_stateowner(&lo->lo_owner);
+	return owner;
+}
+
+static void
+nfsd4_fl_put_owner(fl_owner_t owner)
+{
+	struct nfs4_lockowner *lo = (struct nfs4_lockowner *)owner;
+
+	if (lo)
+		nfs4_put_stateowner(&lo->lo_owner);
+}
+
+static void
+nfsd4_lm_notify(struct file_lock *fl)
+{
+	struct nfs4_lockowner		*lo = (struct nfs4_lockowner *)fl->fl_owner;
+	struct net			*net = lo->lo_owner.so_client->net;
+	struct nfsd_net			*nn = net_generic(net, nfsd_net_id);
+	struct nfsd4_blocked_lock	*nbl = container_of(fl,
+						struct nfsd4_blocked_lock, nbl_lock);
+	bool queue = false;
+
+	/* An empty list means that something else is going to be using it */
+	spin_lock(&nn->blocked_locks_lock);
+	if (!list_empty(&nbl->nbl_list)) {
+		list_del_init(&nbl->nbl_list);
+		list_del_init(&nbl->nbl_lru);
+		queue = true;
+	}
+	spin_unlock(&nn->blocked_locks_lock);
+
+	if (queue)
+		nfsd4_run_cb(&nbl->nbl_cb);
+}
+
+static const struct lock_manager_operations nfsd_posix_mng_ops  = {
+	.lm_notify = nfsd4_lm_notify,
+	.lm_get_owner = nfsd4_fl_get_owner,
+	.lm_put_owner = nfsd4_fl_put_owner,
+};
+
+static inline void
+nfs4_set_lock_denied(struct file_lock *fl, struct nfsd4_lock_denied *deny)
+{
+	struct nfs4_lockowner *lo;
+
+	if (fl->fl_lmops == &nfsd_posix_mng_ops) {
+		lo = (struct nfs4_lockowner *) fl->fl_owner;
+		xdr_netobj_dup(&deny->ld_owner, &lo->lo_owner.so_owner,
+						GFP_KERNEL);
+		if (!deny->ld_owner.data)
+			/* We just don't care that much */
+			goto nevermind;
+		deny->ld_clientid = lo->lo_owner.so_client->cl_clientid;
+	} else {
+nevermind:
+		deny->ld_owner.len = 0;
+		deny->ld_owner.data = NULL;
+		deny->ld_clientid.cl_boot = 0;
+		deny->ld_clientid.cl_id = 0;
+	}
+	deny->ld_start = fl->fl_start;
+	deny->ld_length = NFS4_MAX_UINT64;
+	if (fl->fl_end != NFS4_MAX_UINT64)
+		deny->ld_length = fl->fl_end - fl->fl_start + 1;        
+	deny->ld_type = NFS4_READ_LT;
+	if (fl->fl_type != F_RDLCK)
+		deny->ld_type = NFS4_WRITE_LT;
+}
+
+static struct nfs4_lockowner *
+find_lockowner_str_locked(struct nfs4_client *clp, struct xdr_netobj *owner)
+{
+	unsigned int strhashval = ownerstr_hashval(owner);
+	struct nfs4_stateowner *so;
+
+	lockdep_assert_held(&clp->cl_lock);
+
+	list_for_each_entry(so, &clp->cl_ownerstr_hashtbl[strhashval],
+			    so_strhash) {
+		if (so->so_is_open_owner)
+			continue;
+		if (same_owner_str(so, owner))
+			return lockowner(nfs4_get_stateowner(so));
+	}
+	return NULL;
+}
+
+static struct nfs4_lockowner *
+find_lockowner_str(struct nfs4_client *clp, struct xdr_netobj *owner)
+{
+	struct nfs4_lockowner *lo;
+
+	spin_lock(&clp->cl_lock);
+	lo = find_lockowner_str_locked(clp, owner);
+	spin_unlock(&clp->cl_lock);
+	return lo;
+}
+
+static void nfs4_unhash_lockowner(struct nfs4_stateowner *sop)
+{
+	unhash_lockowner_locked(lockowner(sop));
+}
+
+static void nfs4_free_lockowner(struct nfs4_stateowner *sop)
+{
+	struct nfs4_lockowner *lo = lockowner(sop);
+
+	kmem_cache_free(lockowner_slab, lo);
+}
+
+static const struct nfs4_stateowner_operations lockowner_ops = {
+	.so_unhash =	nfs4_unhash_lockowner,
+	.so_free =	nfs4_free_lockowner,
+};
+
+/*
+ * Alloc a lock owner structure.
+ * Called in nfsd4_lock - therefore, OPEN and OPEN_CONFIRM (if needed) has 
+ * occurred. 
+ *
+ * strhashval = ownerstr_hashval
+ */
+static struct nfs4_lockowner *
+alloc_init_lock_stateowner(unsigned int strhashval, struct nfs4_client *clp,
+			   struct nfs4_ol_stateid *open_stp,
+			   struct nfsd4_lock *lock)
+{
+	struct nfs4_lockowner *lo, *ret;
+
+	lo = alloc_stateowner(lockowner_slab, &lock->lk_new_owner, clp);
+	if (!lo)
+		return NULL;
+	INIT_LIST_HEAD(&lo->lo_blocked);
+	INIT_LIST_HEAD(&lo->lo_owner.so_stateids);
+	lo->lo_owner.so_is_open_owner = 0;
+	lo->lo_owner.so_seqid = lock->lk_new_lock_seqid;
+	lo->lo_owner.so_ops = &lockowner_ops;
+	spin_lock(&clp->cl_lock);
+	ret = find_lockowner_str_locked(clp, &lock->lk_new_owner);
+	if (ret == NULL) {
+		list_add(&lo->lo_owner.so_strhash,
+			 &clp->cl_ownerstr_hashtbl[strhashval]);
+		ret = lo;
+	} else
+		nfs4_free_stateowner(&lo->lo_owner);
+
+	spin_unlock(&clp->cl_lock);
+	return ret;
+}
+
+static struct nfs4_ol_stateid *
+find_lock_stateid(const struct nfs4_lockowner *lo,
+		  const struct nfs4_ol_stateid *ost)
+{
+	struct nfs4_ol_stateid *lst;
+
+	lockdep_assert_held(&ost->st_stid.sc_client->cl_lock);
+
+	/* If ost is not hashed, ost->st_locks will not be valid */
+	if (!nfs4_ol_stateid_unhashed(ost))
+		list_for_each_entry(lst, &ost->st_locks, st_locks) {
+			if (lst->st_stateowner == &lo->lo_owner) {
+				refcount_inc(&lst->st_stid.sc_count);
+				return lst;
+			}
+		}
+	return NULL;
+}
+
+static struct nfs4_ol_stateid *
+init_lock_stateid(struct nfs4_ol_stateid *stp, struct nfs4_lockowner *lo,
+		  struct nfs4_file *fp, struct inode *inode,
+		  struct nfs4_ol_stateid *open_stp)
+{
+	struct nfs4_client *clp = lo->lo_owner.so_client;
+	struct nfs4_ol_stateid *retstp;
+
+	mutex_init(&stp->st_mutex);
+	mutex_lock_nested(&stp->st_mutex, OPEN_STATEID_MUTEX);
+retry:
+	spin_lock(&clp->cl_lock);
+	if (nfs4_ol_stateid_unhashed(open_stp))
+		goto out_close;
+	retstp = find_lock_stateid(lo, open_stp);
+	if (retstp)
+		goto out_found;
+	refcount_inc(&stp->st_stid.sc_count);
+	stp->st_stid.sc_type = NFS4_LOCK_STID;
+	stp->st_stateowner = nfs4_get_stateowner(&lo->lo_owner);
+	get_nfs4_file(fp);
+	stp->st_stid.sc_file = fp;
+	stp->st_access_bmap = 0;
+	stp->st_deny_bmap = open_stp->st_deny_bmap;
+	stp->st_openstp = open_stp;
+	spin_lock(&fp->fi_lock);
+	list_add(&stp->st_locks, &open_stp->st_locks);
+	list_add(&stp->st_perstateowner, &lo->lo_owner.so_stateids);
+	list_add(&stp->st_perfile, &fp->fi_stateids);
+	spin_unlock(&fp->fi_lock);
+	spin_unlock(&clp->cl_lock);
+	return stp;
+out_found:
+	spin_unlock(&clp->cl_lock);
+	if (nfsd4_lock_ol_stateid(retstp) != nfs_ok) {
+		nfs4_put_stid(&retstp->st_stid);
+		goto retry;
+	}
+	/* To keep mutex tracking happy */
+	mutex_unlock(&stp->st_mutex);
+	return retstp;
+out_close:
+	spin_unlock(&clp->cl_lock);
+	mutex_unlock(&stp->st_mutex);
+	return NULL;
+}
+
+static struct nfs4_ol_stateid *
+find_or_create_lock_stateid(struct nfs4_lockowner *lo, struct nfs4_file *fi,
+			    struct inode *inode, struct nfs4_ol_stateid *ost,
+			    bool *new)
+{
+	struct nfs4_stid *ns = NULL;
+	struct nfs4_ol_stateid *lst;
+	struct nfs4_openowner *oo = openowner(ost->st_stateowner);
+	struct nfs4_client *clp = oo->oo_owner.so_client;
+
+	*new = false;
+	spin_lock(&clp->cl_lock);
+	lst = find_lock_stateid(lo, ost);
+	spin_unlock(&clp->cl_lock);
+	if (lst != NULL) {
+		if (nfsd4_lock_ol_stateid(lst) == nfs_ok)
+			goto out;
+		nfs4_put_stid(&lst->st_stid);
+	}
+	ns = nfs4_alloc_stid(clp, stateid_slab, nfs4_free_lock_stateid);
+	if (ns == NULL)
+		return NULL;
+
+	lst = init_lock_stateid(openlockstateid(ns), lo, fi, inode, ost);
+	if (lst == openlockstateid(ns))
+		*new = true;
+	else
+		nfs4_put_stid(ns);
+out:
+	return lst;
+}
+
+static int
+check_lock_length(u64 offset, u64 length)
+{
+	return ((length == 0) || ((length != NFS4_MAX_UINT64) &&
+		(length > ~offset)));
+}
+
+static void get_lock_access(struct nfs4_ol_stateid *lock_stp, u32 access)
+{
+	struct nfs4_file *fp = lock_stp->st_stid.sc_file;
+
+	lockdep_assert_held(&fp->fi_lock);
+
+	if (test_access(access, lock_stp))
+		return;
+	__nfs4_file_get_access(fp, access);
+	set_access(access, lock_stp);
+}
+
+static __be32
+lookup_or_create_lock_state(struct nfsd4_compound_state *cstate,
+			    struct nfs4_ol_stateid *ost,
+			    struct nfsd4_lock *lock,
+			    struct nfs4_ol_stateid **plst, bool *new)
+{
+	__be32 status;
+	struct nfs4_file *fi = ost->st_stid.sc_file;
+	struct nfs4_openowner *oo = openowner(ost->st_stateowner);
+	struct nfs4_client *cl = oo->oo_owner.so_client;
+	struct inode *inode = d_inode(cstate->current_fh.fh_dentry);
+	struct nfs4_lockowner *lo;
+	struct nfs4_ol_stateid *lst;
+	unsigned int strhashval;
+
+	lo = find_lockowner_str(cl, &lock->lk_new_owner);
+	if (!lo) {
+		strhashval = ownerstr_hashval(&lock->lk_new_owner);
+		lo = alloc_init_lock_stateowner(strhashval, cl, ost, lock);
+		if (lo == NULL)
+			return nfserr_jukebox;
+	} else {
+		/* with an existing lockowner, seqids must be the same */
+		status = nfserr_bad_seqid;
+		if (!cstate->minorversion &&
+		    lock->lk_new_lock_seqid != lo->lo_owner.so_seqid)
+			goto out;
+	}
+
+	lst = find_or_create_lock_stateid(lo, fi, inode, ost, new);
+	if (lst == NULL) {
+		status = nfserr_jukebox;
+		goto out;
+	}
+
+	status = nfs_ok;
+	*plst = lst;
+out:
+	nfs4_put_stateowner(&lo->lo_owner);
+	return status;
+}
+
+/*
+ *  LOCK operation 
+ */
+__be32
+nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+	   union nfsd4_op_u *u)
+{
+	struct nfsd4_lock *lock = &u->lock;
+	struct nfs4_openowner *open_sop = NULL;
+	struct nfs4_lockowner *lock_sop = NULL;
+	struct nfs4_ol_stateid *lock_stp = NULL;
+	struct nfs4_ol_stateid *open_stp = NULL;
+	struct nfs4_file *fp;
+	struct nfsd_file *nf = NULL;
+	struct nfsd4_blocked_lock *nbl = NULL;
+	struct file_lock *file_lock = NULL;
+	struct file_lock *conflock = NULL;
+	__be32 status = 0;
+	int lkflg;
+	int err;
+	bool new = false;
+	unsigned char fl_type;
+	unsigned int fl_flags = FL_POSIX;
+	struct net *net = SVC_NET(rqstp);
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	dprintk("NFSD: nfsd4_lock: start=%Ld length=%Ld\n",
+		(long long) lock->lk_offset,
+		(long long) lock->lk_length);
+
+	if (check_lock_length(lock->lk_offset, lock->lk_length))
+		 return nfserr_inval;
+
+	if ((status = fh_verify(rqstp, &cstate->current_fh,
+				S_IFREG, NFSD_MAY_LOCK))) {
+		dprintk("NFSD: nfsd4_lock: permission denied!\n");
+		return status;
+	}
+
+	if (lock->lk_is_new) {
+		if (nfsd4_has_session(cstate))
+			/* See rfc 5661 18.10.3: given clientid is ignored: */
+			memcpy(&lock->lk_new_clientid,
+				&cstate->session->se_client->cl_clientid,
+				sizeof(clientid_t));
+
+		status = nfserr_stale_clientid;
+		if (STALE_CLIENTID(&lock->lk_new_clientid, nn))
+			goto out;
+
+		/* validate and update open stateid and open seqid */
+		status = nfs4_preprocess_confirmed_seqid_op(cstate,
+				        lock->lk_new_open_seqid,
+		                        &lock->lk_new_open_stateid,
+					&open_stp, nn);
+		if (status)
+			goto out;
+		mutex_unlock(&open_stp->st_mutex);
+		open_sop = openowner(open_stp->st_stateowner);
+		status = nfserr_bad_stateid;
+		if (!same_clid(&open_sop->oo_owner.so_client->cl_clientid,
+						&lock->lk_new_clientid))
+			goto out;
+		status = lookup_or_create_lock_state(cstate, open_stp, lock,
+							&lock_stp, &new);
+	} else {
+		status = nfs4_preprocess_seqid_op(cstate,
+				       lock->lk_old_lock_seqid,
+				       &lock->lk_old_lock_stateid,
+				       NFS4_LOCK_STID, &lock_stp, nn);
+	}
+	if (status)
+		goto out;
+	lock_sop = lockowner(lock_stp->st_stateowner);
+
+	lkflg = setlkflg(lock->lk_type);
+	status = nfs4_check_openmode(lock_stp, lkflg);
+	if (status)
+		goto out;
+
+	status = nfserr_grace;
+	if (locks_in_grace(net) && !lock->lk_reclaim)
+		goto out;
+	status = nfserr_no_grace;
+	if (!locks_in_grace(net) && lock->lk_reclaim)
+		goto out;
+
+	fp = lock_stp->st_stid.sc_file;
+	switch (lock->lk_type) {
+		case NFS4_READW_LT:
+			if (nfsd4_has_session(cstate))
+				fl_flags |= FL_SLEEP;
+			fallthrough;
+		case NFS4_READ_LT:
+			spin_lock(&fp->fi_lock);
+			nf = find_readable_file_locked(fp);
+			if (nf)
+				get_lock_access(lock_stp, NFS4_SHARE_ACCESS_READ);
+			spin_unlock(&fp->fi_lock);
+			fl_type = F_RDLCK;
+			break;
+		case NFS4_WRITEW_LT:
+			if (nfsd4_has_session(cstate))
+				fl_flags |= FL_SLEEP;
+			fallthrough;
+		case NFS4_WRITE_LT:
+			spin_lock(&fp->fi_lock);
+			nf = find_writeable_file_locked(fp);
+			if (nf)
+				get_lock_access(lock_stp, NFS4_SHARE_ACCESS_WRITE);
+			spin_unlock(&fp->fi_lock);
+			fl_type = F_WRLCK;
+			break;
+		default:
+			status = nfserr_inval;
+		goto out;
+	}
+
+	if (!nf) {
+		status = nfserr_openmode;
+		goto out;
+	}
+
+	nbl = find_or_allocate_block(lock_sop, &fp->fi_fhandle, nn);
+	if (!nbl) {
+		dprintk("NFSD: %s: unable to allocate block!\n", __func__);
+		status = nfserr_jukebox;
+		goto out;
+	}
+
+	file_lock = &nbl->nbl_lock;
+	file_lock->fl_type = fl_type;
+	file_lock->fl_owner = (fl_owner_t)lockowner(nfs4_get_stateowner(&lock_sop->lo_owner));
+	file_lock->fl_pid = current->tgid;
+	file_lock->fl_file = nf->nf_file;
+	file_lock->fl_flags = fl_flags;
+	file_lock->fl_lmops = &nfsd_posix_mng_ops;
+	file_lock->fl_start = lock->lk_offset;
+	file_lock->fl_end = last_byte_offset(lock->lk_offset, lock->lk_length);
+	nfs4_transform_lock_offset(file_lock);
+
+	conflock = locks_alloc_lock();
+	if (!conflock) {
+		dprintk("NFSD: %s: unable to allocate lock!\n", __func__);
+		status = nfserr_jukebox;
+		goto out;
+	}
+
+	if (fl_flags & FL_SLEEP) {
+		nbl->nbl_time = ktime_get_boottime_seconds();
+		spin_lock(&nn->blocked_locks_lock);
+		list_add_tail(&nbl->nbl_list, &lock_sop->lo_blocked);
+		list_add_tail(&nbl->nbl_lru, &nn->blocked_locks_lru);
+		spin_unlock(&nn->blocked_locks_lock);
+	}
+
+	err = vfs_lock_file(nf->nf_file, F_SETLK, file_lock, conflock);
+	switch (err) {
+	case 0: /* success! */
+		nfs4_inc_and_copy_stateid(&lock->lk_resp_stateid, &lock_stp->st_stid);
+		status = 0;
+		if (lock->lk_reclaim)
+			nn->somebody_reclaimed = true;
+		break;
+	case FILE_LOCK_DEFERRED:
+		nbl = NULL;
+		fallthrough;
+	case -EAGAIN:		/* conflock holds conflicting lock */
+		status = nfserr_denied;
+		dprintk("NFSD: nfsd4_lock: conflicting lock found!\n");
+		nfs4_set_lock_denied(conflock, &lock->lk_denied);
+		break;
+	case -EDEADLK:
+		status = nfserr_deadlock;
+		break;
+	default:
+		dprintk("NFSD: nfsd4_lock: vfs_lock_file() failed! status %d\n",err);
+		status = nfserrno(err);
+		break;
+	}
+out:
+	if (nbl) {
+		/* dequeue it if we queued it before */
+		if (fl_flags & FL_SLEEP) {
+			spin_lock(&nn->blocked_locks_lock);
+			list_del_init(&nbl->nbl_list);
+			list_del_init(&nbl->nbl_lru);
+			spin_unlock(&nn->blocked_locks_lock);
+		}
+		free_blocked_lock(nbl);
+	}
+	if (nf)
+		nfsd_file_put(nf);
+	if (lock_stp) {
+		/* Bump seqid manually if the 4.0 replay owner is openowner */
+		if (cstate->replay_owner &&
+		    cstate->replay_owner != &lock_sop->lo_owner &&
+		    seqid_mutating_err(ntohl(status)))
+			lock_sop->lo_owner.so_seqid++;
+
+		/*
+		 * If this is a new, never-before-used stateid, and we are
+		 * returning an error, then just go ahead and release it.
+		 */
+		if (status && new)
+			release_lock_stateid(lock_stp);
+
+		mutex_unlock(&lock_stp->st_mutex);
+
+		nfs4_put_stid(&lock_stp->st_stid);
+	}
+	if (open_stp)
+		nfs4_put_stid(&open_stp->st_stid);
+	nfsd4_bump_seqid(cstate, status);
+	if (conflock)
+		locks_free_lock(conflock);
+	return status;
+}
+
+/*
+ * The NFSv4 spec allows a client to do a LOCKT without holding an OPEN,
+ * so we do a temporary open here just to get an open file to pass to
+ * vfs_test_lock.
+ */
+static __be32 nfsd_test_lock(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file_lock *lock)
+{
+	struct nfsd_file *nf;
+	__be32 err;
+
+	err = nfsd_file_acquire(rqstp, fhp, NFSD_MAY_READ, &nf);
+	if (err)
+		return err;
+	fh_lock(fhp); /* to block new leases till after test_lock: */
+	err = nfserrno(nfsd_open_break_lease(fhp->fh_dentry->d_inode,
+							NFSD_MAY_READ));
+	if (err)
+		goto out;
+	lock->fl_file = nf->nf_file;
+	err = nfserrno(vfs_test_lock(nf->nf_file, lock));
+	lock->fl_file = NULL;
+out:
+	fh_unlock(fhp);
+	nfsd_file_put(nf);
+	return err;
+}
+
+/*
+ * LOCKT operation
+ */
+__be32
+nfsd4_lockt(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+	    union nfsd4_op_u *u)
+{
+	struct nfsd4_lockt *lockt = &u->lockt;
+	struct file_lock *file_lock = NULL;
+	struct nfs4_lockowner *lo = NULL;
+	__be32 status;
+	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+
+	if (locks_in_grace(SVC_NET(rqstp)))
+		return nfserr_grace;
+
+	if (check_lock_length(lockt->lt_offset, lockt->lt_length))
+		 return nfserr_inval;
+
+	if (!nfsd4_has_session(cstate)) {
+		status = lookup_clientid(&lockt->lt_clientid, cstate, nn,
+					 false);
+		if (status)
+			goto out;
+	}
+
+	if ((status = fh_verify(rqstp, &cstate->current_fh, S_IFREG, 0)))
+		goto out;
+
+	file_lock = locks_alloc_lock();
+	if (!file_lock) {
+		dprintk("NFSD: %s: unable to allocate lock!\n", __func__);
+		status = nfserr_jukebox;
+		goto out;
+	}
+
+	switch (lockt->lt_type) {
+		case NFS4_READ_LT:
+		case NFS4_READW_LT:
+			file_lock->fl_type = F_RDLCK;
+			break;
+		case NFS4_WRITE_LT:
+		case NFS4_WRITEW_LT:
+			file_lock->fl_type = F_WRLCK;
+			break;
+		default:
+			dprintk("NFSD: nfs4_lockt: bad lock type!\n");
+			status = nfserr_inval;
+			goto out;
+	}
+
+	lo = find_lockowner_str(cstate->clp, &lockt->lt_owner);
+	if (lo)
+		file_lock->fl_owner = (fl_owner_t)lo;
+	file_lock->fl_pid = current->tgid;
+	file_lock->fl_flags = FL_POSIX;
+
+	file_lock->fl_start = lockt->lt_offset;
+	file_lock->fl_end = last_byte_offset(lockt->lt_offset, lockt->lt_length);
+
+	nfs4_transform_lock_offset(file_lock);
+
+	status = nfsd_test_lock(rqstp, &cstate->current_fh, file_lock);
+	if (status)
+		goto out;
+
+	if (file_lock->fl_type != F_UNLCK) {
+		status = nfserr_denied;
+		nfs4_set_lock_denied(file_lock, &lockt->lt_denied);
+	}
+out:
+	if (lo)
+		nfs4_put_stateowner(&lo->lo_owner);
+	if (file_lock)
+		locks_free_lock(file_lock);
+	return status;
+}
+
+__be32
+nfsd4_locku(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+	    union nfsd4_op_u *u)
+{
+	struct nfsd4_locku *locku = &u->locku;
+	struct nfs4_ol_stateid *stp;
+	struct nfsd_file *nf = NULL;
+	struct file_lock *file_lock = NULL;
+	__be32 status;
+	int err;
+	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+
+	dprintk("NFSD: nfsd4_locku: start=%Ld length=%Ld\n",
+		(long long) locku->lu_offset,
+		(long long) locku->lu_length);
+
+	if (check_lock_length(locku->lu_offset, locku->lu_length))
+		 return nfserr_inval;
+
+	status = nfs4_preprocess_seqid_op(cstate, locku->lu_seqid,
+					&locku->lu_stateid, NFS4_LOCK_STID,
+					&stp, nn);
+	if (status)
+		goto out;
+	nf = find_any_file(stp->st_stid.sc_file);
+	if (!nf) {
+		status = nfserr_lock_range;
+		goto put_stateid;
+	}
+	file_lock = locks_alloc_lock();
+	if (!file_lock) {
+		dprintk("NFSD: %s: unable to allocate lock!\n", __func__);
+		status = nfserr_jukebox;
+		goto put_file;
+	}
+
+	file_lock->fl_type = F_UNLCK;
+	file_lock->fl_owner = (fl_owner_t)lockowner(nfs4_get_stateowner(stp->st_stateowner));
+	file_lock->fl_pid = current->tgid;
+	file_lock->fl_file = nf->nf_file;
+	file_lock->fl_flags = FL_POSIX;
+	file_lock->fl_lmops = &nfsd_posix_mng_ops;
+	file_lock->fl_start = locku->lu_offset;
+
+	file_lock->fl_end = last_byte_offset(locku->lu_offset,
+						locku->lu_length);
+	nfs4_transform_lock_offset(file_lock);
+
+	err = vfs_lock_file(nf->nf_file, F_SETLK, file_lock, NULL);
+	if (err) {
+		dprintk("NFSD: nfs4_locku: vfs_lock_file failed!\n");
+		goto out_nfserr;
+	}
+	nfs4_inc_and_copy_stateid(&locku->lu_stateid, &stp->st_stid);
+put_file:
+	nfsd_file_put(nf);
+put_stateid:
+	mutex_unlock(&stp->st_mutex);
+	nfs4_put_stid(&stp->st_stid);
+out:
+	nfsd4_bump_seqid(cstate, status);
+	if (file_lock)
+		locks_free_lock(file_lock);
+	return status;
+
+out_nfserr:
+	status = nfserrno(err);
+	goto put_file;
+}
+
+/*
+ * returns
+ * 	true:  locks held by lockowner
+ * 	false: no locks held by lockowner
+ */
+static bool
+check_for_locks(struct nfs4_file *fp, struct nfs4_lockowner *lowner)
+{
+	struct file_lock *fl;
+	int status = false;
+	struct nfsd_file *nf = find_any_file(fp);
+	struct inode *inode;
+	struct file_lock_context *flctx;
+
+	if (!nf) {
+		/* Any valid lock stateid should have some sort of access */
+		WARN_ON_ONCE(1);
+		return status;
+	}
+
+	inode = locks_inode(nf->nf_file);
+	flctx = inode->i_flctx;
+
+	if (flctx && !list_empty_careful(&flctx->flc_posix)) {
+		spin_lock(&flctx->flc_lock);
+		list_for_each_entry(fl, &flctx->flc_posix, fl_list) {
+			if (fl->fl_owner == (fl_owner_t)lowner) {
+				status = true;
+				break;
+			}
+		}
+		spin_unlock(&flctx->flc_lock);
+	}
+	nfsd_file_put(nf);
+	return status;
+}
+
+__be32
+nfsd4_release_lockowner(struct svc_rqst *rqstp,
+			struct nfsd4_compound_state *cstate,
+			union nfsd4_op_u *u)
+{
+	struct nfsd4_release_lockowner *rlockowner = &u->release_lockowner;
+	clientid_t *clid = &rlockowner->rl_clientid;
+	struct nfs4_stateowner *sop;
+	struct nfs4_lockowner *lo = NULL;
+	struct nfs4_ol_stateid *stp;
+	struct xdr_netobj *owner = &rlockowner->rl_owner;
+	unsigned int hashval = ownerstr_hashval(owner);
+	__be32 status;
+	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+	struct nfs4_client *clp;
+	LIST_HEAD (reaplist);
+
+	dprintk("nfsd4_release_lockowner clientid: (%08x/%08x):\n",
+		clid->cl_boot, clid->cl_id);
+
+	status = lookup_clientid(clid, cstate, nn, false);
+	if (status)
+		return status;
+
+	clp = cstate->clp;
+	/* Find the matching lock stateowner */
+	spin_lock(&clp->cl_lock);
+	list_for_each_entry(sop, &clp->cl_ownerstr_hashtbl[hashval],
+			    so_strhash) {
+
+		if (sop->so_is_open_owner || !same_owner_str(sop, owner))
+			continue;
+
+		if (atomic_read(&sop->so_count) != 1) {
+			spin_unlock(&clp->cl_lock);
+			return nfserr_locks_held;
+		}
+
+		lo = lockowner(sop);
+		nfs4_get_stateowner(sop);
+		break;
+	}
+	if (!lo) {
+		spin_unlock(&clp->cl_lock);
+		return status;
+	}
+
+	unhash_lockowner_locked(lo);
+	while (!list_empty(&lo->lo_owner.so_stateids)) {
+		stp = list_first_entry(&lo->lo_owner.so_stateids,
+				       struct nfs4_ol_stateid,
+				       st_perstateowner);
+		WARN_ON(!unhash_lock_stateid(stp));
+		put_ol_stateid_locked(stp, &reaplist);
+	}
+	spin_unlock(&clp->cl_lock);
+	free_ol_stateid_reaplist(&reaplist);
+	remove_blocked_locks(lo);
+	nfs4_put_stateowner(&lo->lo_owner);
+
+	return status;
+}
+
+static inline struct nfs4_client_reclaim *
+alloc_reclaim(void)
+{
+	return kmalloc(sizeof(struct nfs4_client_reclaim), GFP_KERNEL);
+}
+
+bool
+nfs4_has_reclaimed_state(struct xdr_netobj name, struct nfsd_net *nn)
+{
+	struct nfs4_client_reclaim *crp;
+
+	crp = nfsd4_find_reclaim_client(name, nn);
+	return (crp && crp->cr_clp);
+}
+
+/*
+ * failure => all reset bets are off, nfserr_no_grace...
+ *
+ * The caller is responsible for freeing name.data if NULL is returned (it
+ * will be freed in nfs4_remove_reclaim_record in the normal case).
+ */
+struct nfs4_client_reclaim *
+nfs4_client_to_reclaim(struct xdr_netobj name, struct xdr_netobj princhash,
+		struct nfsd_net *nn)
+{
+	unsigned int strhashval;
+	struct nfs4_client_reclaim *crp;
+
+	crp = alloc_reclaim();
+	if (crp) {
+		strhashval = clientstr_hashval(name);
+		INIT_LIST_HEAD(&crp->cr_strhash);
+		list_add(&crp->cr_strhash, &nn->reclaim_str_hashtbl[strhashval]);
+		crp->cr_name.data = name.data;
+		crp->cr_name.len = name.len;
+		crp->cr_princhash.data = princhash.data;
+		crp->cr_princhash.len = princhash.len;
+		crp->cr_clp = NULL;
+		nn->reclaim_str_hashtbl_size++;
+	}
+	return crp;
+}
+
+void
+nfs4_remove_reclaim_record(struct nfs4_client_reclaim *crp, struct nfsd_net *nn)
+{
+	list_del(&crp->cr_strhash);
+	kfree(crp->cr_name.data);
+	kfree(crp->cr_princhash.data);
+	kfree(crp);
+	nn->reclaim_str_hashtbl_size--;
+}
+
+void
+nfs4_release_reclaim(struct nfsd_net *nn)
+{
+	struct nfs4_client_reclaim *crp = NULL;
+	int i;
+
+	for (i = 0; i < CLIENT_HASH_SIZE; i++) {
+		while (!list_empty(&nn->reclaim_str_hashtbl[i])) {
+			crp = list_entry(nn->reclaim_str_hashtbl[i].next,
+			                struct nfs4_client_reclaim, cr_strhash);
+			nfs4_remove_reclaim_record(crp, nn);
+		}
+	}
+	WARN_ON_ONCE(nn->reclaim_str_hashtbl_size);
+}
+
+/*
+ * called from OPEN, CLAIM_PREVIOUS with a new clientid. */
+struct nfs4_client_reclaim *
+nfsd4_find_reclaim_client(struct xdr_netobj name, struct nfsd_net *nn)
+{
+	unsigned int strhashval;
+	struct nfs4_client_reclaim *crp = NULL;
+
+	strhashval = clientstr_hashval(name);
+	list_for_each_entry(crp, &nn->reclaim_str_hashtbl[strhashval], cr_strhash) {
+		if (compare_blob(&crp->cr_name, &name) == 0) {
+			return crp;
+		}
+	}
+	return NULL;
+}
+
+/*
+* Called from OPEN. Look for clientid in reclaim list.
+*/
+__be32
+nfs4_check_open_reclaim(clientid_t *clid,
+		struct nfsd4_compound_state *cstate,
+		struct nfsd_net *nn)
+{
+	__be32 status;
+
+	/* find clientid in conf_id_hashtbl */
+	status = lookup_clientid(clid, cstate, nn, false);
+	if (status)
+		return nfserr_reclaim_bad;
+
+	if (test_bit(NFSD4_CLIENT_RECLAIM_COMPLETE, &cstate->clp->cl_flags))
+		return nfserr_no_grace;
+
+	if (nfsd4_client_record_check(cstate->clp))
+		return nfserr_reclaim_bad;
+
+	return nfs_ok;
+}
+
+/*
+ * Since the lifetime of a delegation isn't limited to that of an open, a
+ * client may quite reasonably hang on to a delegation as long as it has
+ * the inode cached.  This becomes an obvious problem the first time a
+ * client's inode cache approaches the size of the server's total memory.
+ *
+ * For now we avoid this problem by imposing a hard limit on the number
+ * of delegations, which varies according to the server's memory size.
+ */
+static void
+set_max_delegations(void)
+{
+	/*
+	 * Allow at most 4 delegations per megabyte of RAM.  Quick
+	 * estimates suggest that in the worst case (where every delegation
+	 * is for a different inode), a delegation could take about 1.5K,
+	 * giving a worst case usage of about 6% of memory.
+	 */
+	max_delegations = nr_free_buffer_pages() >> (20 - 2 - PAGE_SHIFT);
+}
+
+static int nfs4_state_create_net(struct net *net)
+{
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+	int i;
+
+	nn->conf_id_hashtbl = kmalloc_array(CLIENT_HASH_SIZE,
+					    sizeof(struct list_head),
+					    GFP_KERNEL);
+	if (!nn->conf_id_hashtbl)
+		goto err;
+	nn->unconf_id_hashtbl = kmalloc_array(CLIENT_HASH_SIZE,
+					      sizeof(struct list_head),
+					      GFP_KERNEL);
+	if (!nn->unconf_id_hashtbl)
+		goto err_unconf_id;
+	nn->sessionid_hashtbl = kmalloc_array(SESSION_HASH_SIZE,
+					      sizeof(struct list_head),
+					      GFP_KERNEL);
+	if (!nn->sessionid_hashtbl)
+		goto err_sessionid;
+
+	for (i = 0; i < CLIENT_HASH_SIZE; i++) {
+		INIT_LIST_HEAD(&nn->conf_id_hashtbl[i]);
+		INIT_LIST_HEAD(&nn->unconf_id_hashtbl[i]);
+	}
+	for (i = 0; i < SESSION_HASH_SIZE; i++)
+		INIT_LIST_HEAD(&nn->sessionid_hashtbl[i]);
+	nn->conf_name_tree = RB_ROOT;
+	nn->unconf_name_tree = RB_ROOT;
+	nn->boot_time = ktime_get_real_seconds();
+	nn->grace_ended = false;
+	nn->nfsd4_manager.block_opens = true;
+	INIT_LIST_HEAD(&nn->nfsd4_manager.list);
+	INIT_LIST_HEAD(&nn->client_lru);
+	INIT_LIST_HEAD(&nn->close_lru);
+	INIT_LIST_HEAD(&nn->del_recall_lru);
+	spin_lock_init(&nn->client_lock);
+	spin_lock_init(&nn->s2s_cp_lock);
+	idr_init(&nn->s2s_cp_stateids);
+
+	spin_lock_init(&nn->blocked_locks_lock);
+	INIT_LIST_HEAD(&nn->blocked_locks_lru);
+
+	INIT_DELAYED_WORK(&nn->laundromat_work, laundromat_main);
+	get_net(net);
+
+	return 0;
+
+err_sessionid:
+	kfree(nn->unconf_id_hashtbl);
+err_unconf_id:
+	kfree(nn->conf_id_hashtbl);
+err:
+	return -ENOMEM;
+}
+
+static void
+nfs4_state_destroy_net(struct net *net)
+{
+	int i;
+	struct nfs4_client *clp = NULL;
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	for (i = 0; i < CLIENT_HASH_SIZE; i++) {
+		while (!list_empty(&nn->conf_id_hashtbl[i])) {
+			clp = list_entry(nn->conf_id_hashtbl[i].next, struct nfs4_client, cl_idhash);
+			destroy_client(clp);
+		}
+	}
+
+	WARN_ON(!list_empty(&nn->blocked_locks_lru));
+
+	for (i = 0; i < CLIENT_HASH_SIZE; i++) {
+		while (!list_empty(&nn->unconf_id_hashtbl[i])) {
+			clp = list_entry(nn->unconf_id_hashtbl[i].next, struct nfs4_client, cl_idhash);
+			destroy_client(clp);
+		}
+	}
+
+	kfree(nn->sessionid_hashtbl);
+	kfree(nn->unconf_id_hashtbl);
+	kfree(nn->conf_id_hashtbl);
+	put_net(net);
+}
+
+int
+nfs4_state_start_net(struct net *net)
+{
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+	int ret;
+
+	ret = nfs4_state_create_net(net);
+	if (ret)
+		return ret;
+	locks_start_grace(net, &nn->nfsd4_manager);
+	nfsd4_client_tracking_init(net);
+	if (nn->track_reclaim_completes && nn->reclaim_str_hashtbl_size == 0)
+		goto skip_grace;
+	printk(KERN_INFO "NFSD: starting %lld-second grace period (net %x)\n",
+	       nn->nfsd4_grace, net->ns.inum);
+	trace_nfsd_grace_start(nn);
+	queue_delayed_work(laundry_wq, &nn->laundromat_work, nn->nfsd4_grace * HZ);
+	return 0;
+
+skip_grace:
+	printk(KERN_INFO "NFSD: no clients to reclaim, skipping NFSv4 grace period (net %x)\n",
+			net->ns.inum);
+	queue_delayed_work(laundry_wq, &nn->laundromat_work, nn->nfsd4_lease * HZ);
+	nfsd4_end_grace(nn);
+	return 0;
+}
+
+/* initialization to perform when the nfsd service is started: */
+
+int
+nfs4_state_start(void)
+{
+	int ret;
+
+	laundry_wq = alloc_workqueue("%s", WQ_UNBOUND, 0, "nfsd4");
+	if (laundry_wq == NULL) {
+		ret = -ENOMEM;
+		goto out;
+	}
+	ret = nfsd4_create_callback_queue();
+	if (ret)
+		goto out_free_laundry;
+
+	set_max_delegations();
+	return 0;
+
+out_free_laundry:
+	destroy_workqueue(laundry_wq);
+out:
+	return ret;
+}
+
+void
+nfs4_state_shutdown_net(struct net *net)
+{
+	struct nfs4_delegation *dp = NULL;
+	struct list_head *pos, *next, reaplist;
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	cancel_delayed_work_sync(&nn->laundromat_work);
+	locks_end_grace(&nn->nfsd4_manager);
+
+	INIT_LIST_HEAD(&reaplist);
+	spin_lock(&state_lock);
+	list_for_each_safe(pos, next, &nn->del_recall_lru) {
+		dp = list_entry (pos, struct nfs4_delegation, dl_recall_lru);
+		WARN_ON(!unhash_delegation_locked(dp));
+		list_add(&dp->dl_recall_lru, &reaplist);
+	}
+	spin_unlock(&state_lock);
+	list_for_each_safe(pos, next, &reaplist) {
+		dp = list_entry (pos, struct nfs4_delegation, dl_recall_lru);
+		list_del_init(&dp->dl_recall_lru);
+		destroy_unhashed_deleg(dp);
+	}
+
+	nfsd4_client_tracking_exit(net);
+	nfs4_state_destroy_net(net);
+}
+
+void
+nfs4_state_shutdown(void)
+{
+	destroy_workqueue(laundry_wq);
+	nfsd4_destroy_callback_queue();
+}
+
+static void
+get_stateid(struct nfsd4_compound_state *cstate, stateid_t *stateid)
+{
+	if (HAS_CSTATE_FLAG(cstate, CURRENT_STATE_ID_FLAG) &&
+	    CURRENT_STATEID(stateid))
+		memcpy(stateid, &cstate->current_stateid, sizeof(stateid_t));
+}
+
+static void
+put_stateid(struct nfsd4_compound_state *cstate, stateid_t *stateid)
+{
+	if (cstate->minorversion) {
+		memcpy(&cstate->current_stateid, stateid, sizeof(stateid_t));
+		SET_CSTATE_FLAG(cstate, CURRENT_STATE_ID_FLAG);
+	}
+}
+
+void
+clear_current_stateid(struct nfsd4_compound_state *cstate)
+{
+	CLEAR_CSTATE_FLAG(cstate, CURRENT_STATE_ID_FLAG);
+}
+
+/*
+ * functions to set current state id
+ */
+void
+nfsd4_set_opendowngradestateid(struct nfsd4_compound_state *cstate,
+		union nfsd4_op_u *u)
+{
+	put_stateid(cstate, &u->open_downgrade.od_stateid);
+}
+
+void
+nfsd4_set_openstateid(struct nfsd4_compound_state *cstate,
+		union nfsd4_op_u *u)
+{
+	put_stateid(cstate, &u->open.op_stateid);
+}
+
+void
+nfsd4_set_closestateid(struct nfsd4_compound_state *cstate,
+		union nfsd4_op_u *u)
+{
+	put_stateid(cstate, &u->close.cl_stateid);
+}
+
+void
+nfsd4_set_lockstateid(struct nfsd4_compound_state *cstate,
+		union nfsd4_op_u *u)
+{
+	put_stateid(cstate, &u->lock.lk_resp_stateid);
+}
+
+/*
+ * functions to consume current state id
+ */
+
+void
+nfsd4_get_opendowngradestateid(struct nfsd4_compound_state *cstate,
+		union nfsd4_op_u *u)
+{
+	get_stateid(cstate, &u->open_downgrade.od_stateid);
+}
+
+void
+nfsd4_get_delegreturnstateid(struct nfsd4_compound_state *cstate,
+		union nfsd4_op_u *u)
+{
+	get_stateid(cstate, &u->delegreturn.dr_stateid);
+}
+
+void
+nfsd4_get_freestateid(struct nfsd4_compound_state *cstate,
+		union nfsd4_op_u *u)
+{
+	get_stateid(cstate, &u->free_stateid.fr_stateid);
+}
+
+void
+nfsd4_get_setattrstateid(struct nfsd4_compound_state *cstate,
+		union nfsd4_op_u *u)
+{
+	get_stateid(cstate, &u->setattr.sa_stateid);
+}
+
+void
+nfsd4_get_closestateid(struct nfsd4_compound_state *cstate,
+		union nfsd4_op_u *u)
+{
+	get_stateid(cstate, &u->close.cl_stateid);
+}
+
+void
+nfsd4_get_lockustateid(struct nfsd4_compound_state *cstate,
+		union nfsd4_op_u *u)
+{
+	get_stateid(cstate, &u->locku.lu_stateid);
+}
+
+void
+nfsd4_get_readstateid(struct nfsd4_compound_state *cstate,
+		union nfsd4_op_u *u)
+{
+	get_stateid(cstate, &u->read.rd_stateid);
+}
+
+void
+nfsd4_get_writestateid(struct nfsd4_compound_state *cstate,
+		union nfsd4_op_u *u)
+{
+	get_stateid(cstate, &u->write.wr_stateid);
+}
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
new file mode 100644
index 000000000..dbfa24cf3
--- /dev/null
+++ b/fs/nfsd/nfs4xdr.c
@@ -0,0 +1,5354 @@
+/*
+ *  Server-side XDR for NFSv4
+ *
+ *  Copyright (c) 2002 The Regents of the University of Michigan.
+ *  All rights reserved.
+ *
+ *  Kendrick Smith <kmsmith@umich.edu>
+ *  Andy Adamson   <andros@umich.edu>
+ *
+ *  Redistribution and use in source and binary forms, with or without
+ *  modification, are permitted provided that the following conditions
+ *  are met:
+ *
+ *  1. Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *  2. Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *  3. Neither the name of the University nor the names of its
+ *     contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+ *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <linux/file.h>
+#include <linux/slab.h>
+#include <linux/namei.h>
+#include <linux/statfs.h>
+#include <linux/utsname.h>
+#include <linux/pagemap.h>
+#include <linux/sunrpc/svcauth_gss.h>
+#include <linux/sunrpc/addr.h>
+#include <linux/xattr.h>
+#include <uapi/linux/xattr.h>
+
+#include "idmap.h"
+#include "acl.h"
+#include "xdr4.h"
+#include "vfs.h"
+#include "state.h"
+#include "cache.h"
+#include "netns.h"
+#include "pnfs.h"
+#include "filecache.h"
+
+#ifdef CONFIG_NFSD_V4_SECURITY_LABEL
+#include <linux/security.h>
+#endif
+
+
+#define NFSDDBG_FACILITY		NFSDDBG_XDR
+
+const u32 nfsd_suppattrs[3][3] = {
+	{NFSD4_SUPPORTED_ATTRS_WORD0,
+	 NFSD4_SUPPORTED_ATTRS_WORD1,
+	 NFSD4_SUPPORTED_ATTRS_WORD2},
+
+	{NFSD4_1_SUPPORTED_ATTRS_WORD0,
+	 NFSD4_1_SUPPORTED_ATTRS_WORD1,
+	 NFSD4_1_SUPPORTED_ATTRS_WORD2},
+
+	{NFSD4_1_SUPPORTED_ATTRS_WORD0,
+	 NFSD4_1_SUPPORTED_ATTRS_WORD1,
+	 NFSD4_2_SUPPORTED_ATTRS_WORD2},
+};
+
+/*
+ * As per referral draft, the fsid for a referral MUST be different from the fsid of the containing
+ * directory in order to indicate to the client that a filesystem boundary is present
+ * We use a fixed fsid for a referral
+ */
+#define NFS4_REFERRAL_FSID_MAJOR	0x8000000ULL
+#define NFS4_REFERRAL_FSID_MINOR	0x8000000ULL
+
+static __be32
+check_filename(char *str, int len)
+{
+	int i;
+
+	if (len == 0)
+		return nfserr_inval;
+	if (isdotent(str, len))
+		return nfserr_badname;
+	for (i = 0; i < len; i++)
+		if (str[i] == '/')
+			return nfserr_badname;
+	return 0;
+}
+
+#define DECODE_HEAD				\
+	__be32 *p;				\
+	__be32 status
+#define DECODE_TAIL				\
+	status = 0;				\
+out:						\
+	return status;				\
+xdr_error:					\
+	dprintk("NFSD: xdr error (%s:%d)\n",	\
+			__FILE__, __LINE__);	\
+	status = nfserr_bad_xdr;		\
+	goto out
+
+#define READMEM(x,nbytes) do {			\
+	x = (char *)p;				\
+	p += XDR_QUADLEN(nbytes);		\
+} while (0)
+#define SAVEMEM(x,nbytes) do {			\
+	if (!(x = (p==argp->tmp || p == argp->tmpp) ? \
+ 		savemem(argp, p, nbytes) :	\
+ 		(char *)p)) {			\
+		dprintk("NFSD: xdr error (%s:%d)\n", \
+				__FILE__, __LINE__); \
+		goto xdr_error;			\
+		}				\
+	p += XDR_QUADLEN(nbytes);		\
+} while (0)
+#define COPYMEM(x,nbytes) do {			\
+	memcpy((x), p, nbytes);			\
+	p += XDR_QUADLEN(nbytes);		\
+} while (0)
+
+/* READ_BUF, read_buf(): nbytes must be <= PAGE_SIZE */
+#define READ_BUF(nbytes)  do {			\
+	if (nbytes <= (u32)((char *)argp->end - (char *)argp->p)) {	\
+		p = argp->p;			\
+		argp->p += XDR_QUADLEN(nbytes);	\
+	} else if (!(p = read_buf(argp, nbytes))) { \
+		dprintk("NFSD: xdr error (%s:%d)\n", \
+				__FILE__, __LINE__); \
+		goto xdr_error;			\
+	}					\
+} while (0)
+
+static void next_decode_page(struct nfsd4_compoundargs *argp)
+{
+	argp->p = page_address(argp->pagelist[0]);
+	argp->pagelist++;
+	if (argp->pagelen < PAGE_SIZE) {
+		argp->end = argp->p + XDR_QUADLEN(argp->pagelen);
+		argp->pagelen = 0;
+	} else {
+		argp->end = argp->p + (PAGE_SIZE>>2);
+		argp->pagelen -= PAGE_SIZE;
+	}
+}
+
+static __be32 *read_buf(struct nfsd4_compoundargs *argp, u32 nbytes)
+{
+	/* We want more bytes than seem to be available.
+	 * Maybe we need a new page, maybe we have just run out
+	 */
+	unsigned int avail = (char *)argp->end - (char *)argp->p;
+	__be32 *p;
+
+	if (argp->pagelen == 0) {
+		struct kvec *vec = &argp->rqstp->rq_arg.tail[0];
+
+		if (!argp->tail) {
+			argp->tail = true;
+			avail = vec->iov_len;
+			argp->p = vec->iov_base;
+			argp->end = vec->iov_base + avail;
+		}
+
+		if (avail < nbytes)
+			return NULL;
+
+		p = argp->p;
+		argp->p += XDR_QUADLEN(nbytes);
+		return p;
+	}
+
+	if (avail + argp->pagelen < nbytes)
+		return NULL;
+	if (avail + PAGE_SIZE < nbytes) /* need more than a page !! */
+		return NULL;
+	/* ok, we can do it with the current plus the next page */
+	if (nbytes <= sizeof(argp->tmp))
+		p = argp->tmp;
+	else {
+		kfree(argp->tmpp);
+		p = argp->tmpp = kmalloc(nbytes, GFP_KERNEL);
+		if (!p)
+			return NULL;
+		
+	}
+	/*
+	 * The following memcpy is safe because read_buf is always
+	 * called with nbytes > avail, and the two cases above both
+	 * guarantee p points to at least nbytes bytes.
+	 */
+	memcpy(p, argp->p, avail);
+	next_decode_page(argp);
+	memcpy(((char*)p)+avail, argp->p, (nbytes - avail));
+	argp->p += XDR_QUADLEN(nbytes - avail);
+	return p;
+}
+
+static unsigned int compoundargs_bytes_left(struct nfsd4_compoundargs *argp)
+{
+	unsigned int this = (char *)argp->end - (char *)argp->p;
+
+	return this + argp->pagelen;
+}
+
+static int zero_clientid(clientid_t *clid)
+{
+	return (clid->cl_boot == 0) && (clid->cl_id == 0);
+}
+
+/**
+ * svcxdr_tmpalloc - allocate memory to be freed after compound processing
+ * @argp: NFSv4 compound argument structure
+ * @len: length of buffer to allocate
+ *
+ * Allocates a buffer of size @len to be freed when processing the compound
+ * operation described in @argp finishes.
+ */
+static void *
+svcxdr_tmpalloc(struct nfsd4_compoundargs *argp, u32 len)
+{
+	struct svcxdr_tmpbuf *tb;
+
+	tb = kmalloc(sizeof(*tb) + len, GFP_KERNEL);
+	if (!tb)
+		return NULL;
+	tb->next = argp->to_free;
+	argp->to_free = tb;
+	return tb->buf;
+}
+
+/*
+ * For xdr strings that need to be passed to other kernel api's
+ * as null-terminated strings.
+ *
+ * Note null-terminating in place usually isn't safe since the
+ * buffer might end on a page boundary.
+ */
+static char *
+svcxdr_dupstr(struct nfsd4_compoundargs *argp, void *buf, u32 len)
+{
+	char *p = svcxdr_tmpalloc(argp, len + 1);
+
+	if (!p)
+		return NULL;
+	memcpy(p, buf, len);
+	p[len] = '\0';
+	return p;
+}
+
+static __be32
+svcxdr_construct_vector(struct nfsd4_compoundargs *argp, struct kvec *head,
+			struct page ***pagelist, u32 buflen)
+{
+	int avail;
+	int len;
+	int pages;
+
+	/* Sorry .. no magic macros for this.. *
+	 * READ_BUF(write->wr_buflen);
+	 * SAVEMEM(write->wr_buf, write->wr_buflen);
+	 */
+	avail = (char *)argp->end - (char *)argp->p;
+	if (avail + argp->pagelen < buflen) {
+		dprintk("NFSD: xdr error (%s:%d)\n",
+			       __FILE__, __LINE__);
+		return nfserr_bad_xdr;
+	}
+	head->iov_base = argp->p;
+	head->iov_len = avail;
+	*pagelist = argp->pagelist;
+
+	len = XDR_QUADLEN(buflen) << 2;
+	if (len >= avail) {
+		len -= avail;
+
+		pages = len >> PAGE_SHIFT;
+		argp->pagelist += pages;
+		argp->pagelen -= pages * PAGE_SIZE;
+		len -= pages * PAGE_SIZE;
+
+		next_decode_page(argp);
+	}
+	argp->p += XDR_QUADLEN(len);
+
+	return 0;
+}
+
+/**
+ * savemem - duplicate a chunk of memory for later processing
+ * @argp: NFSv4 compound argument structure to be freed with
+ * @p: pointer to be duplicated
+ * @nbytes: length to be duplicated
+ *
+ * Returns a pointer to a copy of @nbytes bytes of memory at @p
+ * that are preserved until processing of the NFSv4 compound
+ * operation described by @argp finishes.
+ */
+static char *savemem(struct nfsd4_compoundargs *argp, __be32 *p, int nbytes)
+{
+	void *ret;
+
+	ret = svcxdr_tmpalloc(argp, nbytes);
+	if (!ret)
+		return NULL;
+	memcpy(ret, p, nbytes);
+	return ret;
+}
+
+static __be32
+nfsd4_decode_time(struct nfsd4_compoundargs *argp, struct timespec64 *tv)
+{
+	DECODE_HEAD;
+
+	READ_BUF(12);
+	p = xdr_decode_hyper(p, &tv->tv_sec);
+	tv->tv_nsec = be32_to_cpup(p++);
+	if (tv->tv_nsec >= (u32)1000000000)
+		return nfserr_inval;
+
+	DECODE_TAIL;
+}
+
+static __be32
+nfsd4_decode_bitmap(struct nfsd4_compoundargs *argp, u32 *bmval)
+{
+	u32 bmlen;
+	DECODE_HEAD;
+
+	bmval[0] = 0;
+	bmval[1] = 0;
+	bmval[2] = 0;
+
+	READ_BUF(4);
+	bmlen = be32_to_cpup(p++);
+	if (bmlen > 1000)
+		goto xdr_error;
+
+	READ_BUF(bmlen << 2);
+	if (bmlen > 0)
+		bmval[0] = be32_to_cpup(p++);
+	if (bmlen > 1)
+		bmval[1] = be32_to_cpup(p++);
+	if (bmlen > 2)
+		bmval[2] = be32_to_cpup(p++);
+
+	DECODE_TAIL;
+}
+
+static __be32
+nfsd4_decode_fattr(struct nfsd4_compoundargs *argp, u32 *bmval,
+		   struct iattr *iattr, struct nfs4_acl **acl,
+		   struct xdr_netobj *label, int *umask)
+{
+	int expected_len, len = 0;
+	u32 dummy32;
+	char *buf;
+
+	DECODE_HEAD;
+	iattr->ia_valid = 0;
+	if ((status = nfsd4_decode_bitmap(argp, bmval)))
+		return status;
+
+	if (bmval[0] & ~NFSD_WRITEABLE_ATTRS_WORD0
+	    || bmval[1] & ~NFSD_WRITEABLE_ATTRS_WORD1
+	    || bmval[2] & ~NFSD_WRITEABLE_ATTRS_WORD2) {
+		if (nfsd_attrs_supported(argp->minorversion, bmval))
+			return nfserr_inval;
+		return nfserr_attrnotsupp;
+	}
+
+	READ_BUF(4);
+	expected_len = be32_to_cpup(p++);
+
+	if (bmval[0] & FATTR4_WORD0_SIZE) {
+		READ_BUF(8);
+		len += 8;
+		p = xdr_decode_hyper(p, &iattr->ia_size);
+		iattr->ia_valid |= ATTR_SIZE;
+	}
+	if (bmval[0] & FATTR4_WORD0_ACL) {
+		u32 nace;
+		struct nfs4_ace *ace;
+
+		READ_BUF(4); len += 4;
+		nace = be32_to_cpup(p++);
+
+		if (nace > compoundargs_bytes_left(argp)/20)
+			/*
+			 * Even with 4-byte names there wouldn't be
+			 * space for that many aces; something fishy is
+			 * going on:
+			 */
+			return nfserr_fbig;
+
+		*acl = svcxdr_tmpalloc(argp, nfs4_acl_bytes(nace));
+		if (*acl == NULL)
+			return nfserr_jukebox;
+
+		(*acl)->naces = nace;
+		for (ace = (*acl)->aces; ace < (*acl)->aces + nace; ace++) {
+			READ_BUF(16); len += 16;
+			ace->type = be32_to_cpup(p++);
+			ace->flag = be32_to_cpup(p++);
+			ace->access_mask = be32_to_cpup(p++);
+			dummy32 = be32_to_cpup(p++);
+			READ_BUF(dummy32);
+			len += XDR_QUADLEN(dummy32) << 2;
+			READMEM(buf, dummy32);
+			ace->whotype = nfs4_acl_get_whotype(buf, dummy32);
+			status = nfs_ok;
+			if (ace->whotype != NFS4_ACL_WHO_NAMED)
+				;
+			else if (ace->flag & NFS4_ACE_IDENTIFIER_GROUP)
+				status = nfsd_map_name_to_gid(argp->rqstp,
+						buf, dummy32, &ace->who_gid);
+			else
+				status = nfsd_map_name_to_uid(argp->rqstp,
+						buf, dummy32, &ace->who_uid);
+			if (status)
+				return status;
+		}
+	} else
+		*acl = NULL;
+	if (bmval[1] & FATTR4_WORD1_MODE) {
+		READ_BUF(4);
+		len += 4;
+		iattr->ia_mode = be32_to_cpup(p++);
+		iattr->ia_mode &= (S_IFMT | S_IALLUGO);
+		iattr->ia_valid |= ATTR_MODE;
+	}
+	if (bmval[1] & FATTR4_WORD1_OWNER) {
+		READ_BUF(4);
+		len += 4;
+		dummy32 = be32_to_cpup(p++);
+		READ_BUF(dummy32);
+		len += (XDR_QUADLEN(dummy32) << 2);
+		READMEM(buf, dummy32);
+		if ((status = nfsd_map_name_to_uid(argp->rqstp, buf, dummy32, &iattr->ia_uid)))
+			return status;
+		iattr->ia_valid |= ATTR_UID;
+	}
+	if (bmval[1] & FATTR4_WORD1_OWNER_GROUP) {
+		READ_BUF(4);
+		len += 4;
+		dummy32 = be32_to_cpup(p++);
+		READ_BUF(dummy32);
+		len += (XDR_QUADLEN(dummy32) << 2);
+		READMEM(buf, dummy32);
+		if ((status = nfsd_map_name_to_gid(argp->rqstp, buf, dummy32, &iattr->ia_gid)))
+			return status;
+		iattr->ia_valid |= ATTR_GID;
+	}
+	if (bmval[1] & FATTR4_WORD1_TIME_ACCESS_SET) {
+		READ_BUF(4);
+		len += 4;
+		dummy32 = be32_to_cpup(p++);
+		switch (dummy32) {
+		case NFS4_SET_TO_CLIENT_TIME:
+			len += 12;
+			status = nfsd4_decode_time(argp, &iattr->ia_atime);
+			if (status)
+				return status;
+			iattr->ia_valid |= (ATTR_ATIME | ATTR_ATIME_SET);
+			break;
+		case NFS4_SET_TO_SERVER_TIME:
+			iattr->ia_valid |= ATTR_ATIME;
+			break;
+		default:
+			goto xdr_error;
+		}
+	}
+	if (bmval[1] & FATTR4_WORD1_TIME_MODIFY_SET) {
+		READ_BUF(4);
+		len += 4;
+		dummy32 = be32_to_cpup(p++);
+		switch (dummy32) {
+		case NFS4_SET_TO_CLIENT_TIME:
+			len += 12;
+			status = nfsd4_decode_time(argp, &iattr->ia_mtime);
+			if (status)
+				return status;
+			iattr->ia_valid |= (ATTR_MTIME | ATTR_MTIME_SET);
+			break;
+		case NFS4_SET_TO_SERVER_TIME:
+			iattr->ia_valid |= ATTR_MTIME;
+			break;
+		default:
+			goto xdr_error;
+		}
+	}
+
+	label->len = 0;
+	if (IS_ENABLED(CONFIG_NFSD_V4_SECURITY_LABEL) &&
+	    bmval[2] & FATTR4_WORD2_SECURITY_LABEL) {
+		READ_BUF(4);
+		len += 4;
+		dummy32 = be32_to_cpup(p++); /* lfs: we don't use it */
+		READ_BUF(4);
+		len += 4;
+		dummy32 = be32_to_cpup(p++); /* pi: we don't use it either */
+		READ_BUF(4);
+		len += 4;
+		dummy32 = be32_to_cpup(p++);
+		READ_BUF(dummy32);
+		if (dummy32 > NFS4_MAXLABELLEN)
+			return nfserr_badlabel;
+		len += (XDR_QUADLEN(dummy32) << 2);
+		READMEM(buf, dummy32);
+		label->len = dummy32;
+		label->data = svcxdr_dupstr(argp, buf, dummy32);
+		if (!label->data)
+			return nfserr_jukebox;
+	}
+	if (bmval[2] & FATTR4_WORD2_MODE_UMASK) {
+		if (!umask)
+			goto xdr_error;
+		READ_BUF(8);
+		len += 8;
+		dummy32 = be32_to_cpup(p++);
+		iattr->ia_mode = dummy32 & (S_IFMT | S_IALLUGO);
+		dummy32 = be32_to_cpup(p++);
+		*umask = dummy32 & S_IRWXUGO;
+		iattr->ia_valid |= ATTR_MODE;
+	}
+	if (len != expected_len)
+		goto xdr_error;
+
+	DECODE_TAIL;
+}
+
+static __be32
+nfsd4_decode_stateid(struct nfsd4_compoundargs *argp, stateid_t *sid)
+{
+	DECODE_HEAD;
+
+	READ_BUF(sizeof(stateid_t));
+	sid->si_generation = be32_to_cpup(p++);
+	COPYMEM(&sid->si_opaque, sizeof(stateid_opaque_t));
+
+	DECODE_TAIL;
+}
+
+static __be32
+nfsd4_decode_access(struct nfsd4_compoundargs *argp, struct nfsd4_access *access)
+{
+	DECODE_HEAD;
+
+	READ_BUF(4);
+	access->ac_req_access = be32_to_cpup(p++);
+
+	DECODE_TAIL;
+}
+
+static __be32 nfsd4_decode_cb_sec(struct nfsd4_compoundargs *argp, struct nfsd4_cb_sec *cbs)
+{
+	DECODE_HEAD;
+	struct user_namespace *userns = nfsd_user_namespace(argp->rqstp);
+	u32 dummy, uid, gid;
+	char *machine_name;
+	int i;
+	int nr_secflavs;
+
+	/* callback_sec_params4 */
+	READ_BUF(4);
+	nr_secflavs = be32_to_cpup(p++);
+	if (nr_secflavs)
+		cbs->flavor = (u32)(-1);
+	else
+		/* Is this legal? Be generous, take it to mean AUTH_NONE: */
+		cbs->flavor = 0;
+	for (i = 0; i < nr_secflavs; ++i) {
+		READ_BUF(4);
+		dummy = be32_to_cpup(p++);
+		switch (dummy) {
+		case RPC_AUTH_NULL:
+			/* Nothing to read */
+			if (cbs->flavor == (u32)(-1))
+				cbs->flavor = RPC_AUTH_NULL;
+			break;
+		case RPC_AUTH_UNIX:
+			READ_BUF(8);
+			/* stamp */
+			dummy = be32_to_cpup(p++);
+
+			/* machine name */
+			dummy = be32_to_cpup(p++);
+			READ_BUF(dummy);
+			SAVEMEM(machine_name, dummy);
+
+			/* uid, gid */
+			READ_BUF(8);
+			uid = be32_to_cpup(p++);
+			gid = be32_to_cpup(p++);
+
+			/* more gids */
+			READ_BUF(4);
+			dummy = be32_to_cpup(p++);
+			READ_BUF(dummy * 4);
+			if (cbs->flavor == (u32)(-1)) {
+				kuid_t kuid = make_kuid(userns, uid);
+				kgid_t kgid = make_kgid(userns, gid);
+				if (uid_valid(kuid) && gid_valid(kgid)) {
+					cbs->uid = kuid;
+					cbs->gid = kgid;
+					cbs->flavor = RPC_AUTH_UNIX;
+				} else {
+					dprintk("RPC_AUTH_UNIX with invalid"
+						"uid or gid ignoring!\n");
+				}
+			}
+			break;
+		case RPC_AUTH_GSS:
+			dprintk("RPC_AUTH_GSS callback secflavor "
+				"not supported!\n");
+			READ_BUF(8);
+			/* gcbp_service */
+			dummy = be32_to_cpup(p++);
+			/* gcbp_handle_from_server */
+			dummy = be32_to_cpup(p++);
+			READ_BUF(dummy);
+			p += XDR_QUADLEN(dummy);
+			/* gcbp_handle_from_client */
+			READ_BUF(4);
+			dummy = be32_to_cpup(p++);
+			READ_BUF(dummy);
+			break;
+		default:
+			dprintk("Illegal callback secflavor\n");
+			return nfserr_inval;
+		}
+	}
+	DECODE_TAIL;
+}
+
+static __be32 nfsd4_decode_backchannel_ctl(struct nfsd4_compoundargs *argp, struct nfsd4_backchannel_ctl *bc)
+{
+	DECODE_HEAD;
+
+	READ_BUF(4);
+	bc->bc_cb_program = be32_to_cpup(p++);
+	nfsd4_decode_cb_sec(argp, &bc->bc_cb_sec);
+
+	DECODE_TAIL;
+}
+
+static __be32 nfsd4_decode_bind_conn_to_session(struct nfsd4_compoundargs *argp, struct nfsd4_bind_conn_to_session *bcts)
+{
+	DECODE_HEAD;
+
+	READ_BUF(NFS4_MAX_SESSIONID_LEN + 8);
+	COPYMEM(bcts->sessionid.data, NFS4_MAX_SESSIONID_LEN);
+	bcts->dir = be32_to_cpup(p++);
+	/* XXX: skipping ctsa_use_conn_in_rdma_mode.  Perhaps Tom Tucker
+	 * could help us figure out we should be using it. */
+	DECODE_TAIL;
+}
+
+static __be32
+nfsd4_decode_close(struct nfsd4_compoundargs *argp, struct nfsd4_close *close)
+{
+	DECODE_HEAD;
+
+	READ_BUF(4);
+	close->cl_seqid = be32_to_cpup(p++);
+	return nfsd4_decode_stateid(argp, &close->cl_stateid);
+
+	DECODE_TAIL;
+}
+
+
+static __be32
+nfsd4_decode_commit(struct nfsd4_compoundargs *argp, struct nfsd4_commit *commit)
+{
+	DECODE_HEAD;
+
+	READ_BUF(12);
+	p = xdr_decode_hyper(p, &commit->co_offset);
+	commit->co_count = be32_to_cpup(p++);
+
+	DECODE_TAIL;
+}
+
+static __be32
+nfsd4_decode_create(struct nfsd4_compoundargs *argp, struct nfsd4_create *create)
+{
+	DECODE_HEAD;
+
+	READ_BUF(4);
+	create->cr_type = be32_to_cpup(p++);
+	switch (create->cr_type) {
+	case NF4LNK:
+		READ_BUF(4);
+		create->cr_datalen = be32_to_cpup(p++);
+		READ_BUF(create->cr_datalen);
+		create->cr_data = svcxdr_dupstr(argp, p, create->cr_datalen);
+		if (!create->cr_data)
+			return nfserr_jukebox;
+		break;
+	case NF4BLK:
+	case NF4CHR:
+		READ_BUF(8);
+		create->cr_specdata1 = be32_to_cpup(p++);
+		create->cr_specdata2 = be32_to_cpup(p++);
+		break;
+	case NF4SOCK:
+	case NF4FIFO:
+	case NF4DIR:
+	default:
+		break;
+	}
+
+	READ_BUF(4);
+	create->cr_namelen = be32_to_cpup(p++);
+	READ_BUF(create->cr_namelen);
+	SAVEMEM(create->cr_name, create->cr_namelen);
+	if ((status = check_filename(create->cr_name, create->cr_namelen)))
+		return status;
+
+	status = nfsd4_decode_fattr(argp, create->cr_bmval, &create->cr_iattr,
+				    &create->cr_acl, &create->cr_label,
+				    &create->cr_umask);
+	if (status)
+		goto out;
+
+	DECODE_TAIL;
+}
+
+static inline __be32
+nfsd4_decode_delegreturn(struct nfsd4_compoundargs *argp, struct nfsd4_delegreturn *dr)
+{
+	return nfsd4_decode_stateid(argp, &dr->dr_stateid);
+}
+
+static inline __be32
+nfsd4_decode_getattr(struct nfsd4_compoundargs *argp, struct nfsd4_getattr *getattr)
+{
+	return nfsd4_decode_bitmap(argp, getattr->ga_bmval);
+}
+
+static __be32
+nfsd4_decode_link(struct nfsd4_compoundargs *argp, struct nfsd4_link *link)
+{
+	DECODE_HEAD;
+
+	READ_BUF(4);
+	link->li_namelen = be32_to_cpup(p++);
+	READ_BUF(link->li_namelen);
+	SAVEMEM(link->li_name, link->li_namelen);
+	if ((status = check_filename(link->li_name, link->li_namelen)))
+		return status;
+
+	DECODE_TAIL;
+}
+
+static __be32
+nfsd4_decode_lock(struct nfsd4_compoundargs *argp, struct nfsd4_lock *lock)
+{
+	DECODE_HEAD;
+
+	/*
+	* type, reclaim(boolean), offset, length, new_lock_owner(boolean)
+	*/
+	READ_BUF(28);
+	lock->lk_type = be32_to_cpup(p++);
+	if ((lock->lk_type < NFS4_READ_LT) || (lock->lk_type > NFS4_WRITEW_LT))
+		goto xdr_error;
+	lock->lk_reclaim = be32_to_cpup(p++);
+	p = xdr_decode_hyper(p, &lock->lk_offset);
+	p = xdr_decode_hyper(p, &lock->lk_length);
+	lock->lk_is_new = be32_to_cpup(p++);
+
+	if (lock->lk_is_new) {
+		READ_BUF(4);
+		lock->lk_new_open_seqid = be32_to_cpup(p++);
+		status = nfsd4_decode_stateid(argp, &lock->lk_new_open_stateid);
+		if (status)
+			return status;
+		READ_BUF(8 + sizeof(clientid_t));
+		lock->lk_new_lock_seqid = be32_to_cpup(p++);
+		COPYMEM(&lock->lk_new_clientid, sizeof(clientid_t));
+		lock->lk_new_owner.len = be32_to_cpup(p++);
+		READ_BUF(lock->lk_new_owner.len);
+		READMEM(lock->lk_new_owner.data, lock->lk_new_owner.len);
+	} else {
+		status = nfsd4_decode_stateid(argp, &lock->lk_old_lock_stateid);
+		if (status)
+			return status;
+		READ_BUF(4);
+		lock->lk_old_lock_seqid = be32_to_cpup(p++);
+	}
+
+	DECODE_TAIL;
+}
+
+static __be32
+nfsd4_decode_lockt(struct nfsd4_compoundargs *argp, struct nfsd4_lockt *lockt)
+{
+	DECODE_HEAD;
+		        
+	READ_BUF(32);
+	lockt->lt_type = be32_to_cpup(p++);
+	if((lockt->lt_type < NFS4_READ_LT) || (lockt->lt_type > NFS4_WRITEW_LT))
+		goto xdr_error;
+	p = xdr_decode_hyper(p, &lockt->lt_offset);
+	p = xdr_decode_hyper(p, &lockt->lt_length);
+	COPYMEM(&lockt->lt_clientid, 8);
+	lockt->lt_owner.len = be32_to_cpup(p++);
+	READ_BUF(lockt->lt_owner.len);
+	READMEM(lockt->lt_owner.data, lockt->lt_owner.len);
+
+	DECODE_TAIL;
+}
+
+static __be32
+nfsd4_decode_locku(struct nfsd4_compoundargs *argp, struct nfsd4_locku *locku)
+{
+	DECODE_HEAD;
+
+	READ_BUF(8);
+	locku->lu_type = be32_to_cpup(p++);
+	if ((locku->lu_type < NFS4_READ_LT) || (locku->lu_type > NFS4_WRITEW_LT))
+		goto xdr_error;
+	locku->lu_seqid = be32_to_cpup(p++);
+	status = nfsd4_decode_stateid(argp, &locku->lu_stateid);
+	if (status)
+		return status;
+	READ_BUF(16);
+	p = xdr_decode_hyper(p, &locku->lu_offset);
+	p = xdr_decode_hyper(p, &locku->lu_length);
+
+	DECODE_TAIL;
+}
+
+static __be32
+nfsd4_decode_lookup(struct nfsd4_compoundargs *argp, struct nfsd4_lookup *lookup)
+{
+	DECODE_HEAD;
+
+	READ_BUF(4);
+	lookup->lo_len = be32_to_cpup(p++);
+	READ_BUF(lookup->lo_len);
+	SAVEMEM(lookup->lo_name, lookup->lo_len);
+	if ((status = check_filename(lookup->lo_name, lookup->lo_len)))
+		return status;
+
+	DECODE_TAIL;
+}
+
+static __be32 nfsd4_decode_share_access(struct nfsd4_compoundargs *argp, u32 *share_access, u32 *deleg_want, u32 *deleg_when)
+{
+	__be32 *p;
+	u32 w;
+
+	READ_BUF(4);
+	w = be32_to_cpup(p++);
+	*share_access = w & NFS4_SHARE_ACCESS_MASK;
+	*deleg_want = w & NFS4_SHARE_WANT_MASK;
+	if (deleg_when)
+		*deleg_when = w & NFS4_SHARE_WHEN_MASK;
+
+	switch (w & NFS4_SHARE_ACCESS_MASK) {
+	case NFS4_SHARE_ACCESS_READ:
+	case NFS4_SHARE_ACCESS_WRITE:
+	case NFS4_SHARE_ACCESS_BOTH:
+		break;
+	default:
+		return nfserr_bad_xdr;
+	}
+	w &= ~NFS4_SHARE_ACCESS_MASK;
+	if (!w)
+		return nfs_ok;
+	if (!argp->minorversion)
+		return nfserr_bad_xdr;
+	switch (w & NFS4_SHARE_WANT_MASK) {
+	case NFS4_SHARE_WANT_NO_PREFERENCE:
+	case NFS4_SHARE_WANT_READ_DELEG:
+	case NFS4_SHARE_WANT_WRITE_DELEG:
+	case NFS4_SHARE_WANT_ANY_DELEG:
+	case NFS4_SHARE_WANT_NO_DELEG:
+	case NFS4_SHARE_WANT_CANCEL:
+		break;
+	default:
+		return nfserr_bad_xdr;
+	}
+	w &= ~NFS4_SHARE_WANT_MASK;
+	if (!w)
+		return nfs_ok;
+
+	if (!deleg_when)	/* open_downgrade */
+		return nfserr_inval;
+	switch (w) {
+	case NFS4_SHARE_SIGNAL_DELEG_WHEN_RESRC_AVAIL:
+	case NFS4_SHARE_PUSH_DELEG_WHEN_UNCONTENDED:
+	case (NFS4_SHARE_SIGNAL_DELEG_WHEN_RESRC_AVAIL |
+	      NFS4_SHARE_PUSH_DELEG_WHEN_UNCONTENDED):
+		return nfs_ok;
+	}
+xdr_error:
+	return nfserr_bad_xdr;
+}
+
+static __be32 nfsd4_decode_share_deny(struct nfsd4_compoundargs *argp, u32 *x)
+{
+	__be32 *p;
+
+	READ_BUF(4);
+	*x = be32_to_cpup(p++);
+	/* Note: unlinke access bits, deny bits may be zero. */
+	if (*x & ~NFS4_SHARE_DENY_BOTH)
+		return nfserr_bad_xdr;
+	return nfs_ok;
+xdr_error:
+	return nfserr_bad_xdr;
+}
+
+static __be32 nfsd4_decode_opaque(struct nfsd4_compoundargs *argp, struct xdr_netobj *o)
+{
+	__be32 *p;
+
+	READ_BUF(4);
+	o->len = be32_to_cpup(p++);
+
+	if (o->len == 0 || o->len > NFS4_OPAQUE_LIMIT)
+		return nfserr_bad_xdr;
+
+	READ_BUF(o->len);
+	SAVEMEM(o->data, o->len);
+	return nfs_ok;
+xdr_error:
+	return nfserr_bad_xdr;
+}
+
+static __be32
+nfsd4_decode_open(struct nfsd4_compoundargs *argp, struct nfsd4_open *open)
+{
+	DECODE_HEAD;
+	u32 dummy;
+
+	memset(open->op_bmval, 0, sizeof(open->op_bmval));
+	open->op_iattr.ia_valid = 0;
+	open->op_openowner = NULL;
+
+	open->op_xdr_error = 0;
+	/* seqid, share_access, share_deny, clientid, ownerlen */
+	READ_BUF(4);
+	open->op_seqid = be32_to_cpup(p++);
+	/* decode, yet ignore deleg_when until supported */
+	status = nfsd4_decode_share_access(argp, &open->op_share_access,
+					   &open->op_deleg_want, &dummy);
+	if (status)
+		goto xdr_error;
+	status = nfsd4_decode_share_deny(argp, &open->op_share_deny);
+	if (status)
+		goto xdr_error;
+	READ_BUF(sizeof(clientid_t));
+	COPYMEM(&open->op_clientid, sizeof(clientid_t));
+	status = nfsd4_decode_opaque(argp, &open->op_owner);
+	if (status)
+		goto xdr_error;
+	READ_BUF(4);
+	open->op_create = be32_to_cpup(p++);
+	switch (open->op_create) {
+	case NFS4_OPEN_NOCREATE:
+		break;
+	case NFS4_OPEN_CREATE:
+		READ_BUF(4);
+		open->op_createmode = be32_to_cpup(p++);
+		switch (open->op_createmode) {
+		case NFS4_CREATE_UNCHECKED:
+		case NFS4_CREATE_GUARDED:
+			status = nfsd4_decode_fattr(argp, open->op_bmval,
+				&open->op_iattr, &open->op_acl, &open->op_label,
+				&open->op_umask);
+			if (status)
+				goto out;
+			break;
+		case NFS4_CREATE_EXCLUSIVE:
+			READ_BUF(NFS4_VERIFIER_SIZE);
+			COPYMEM(open->op_verf.data, NFS4_VERIFIER_SIZE);
+			break;
+		case NFS4_CREATE_EXCLUSIVE4_1:
+			if (argp->minorversion < 1)
+				goto xdr_error;
+			READ_BUF(NFS4_VERIFIER_SIZE);
+			COPYMEM(open->op_verf.data, NFS4_VERIFIER_SIZE);
+			status = nfsd4_decode_fattr(argp, open->op_bmval,
+				&open->op_iattr, &open->op_acl, &open->op_label,
+				&open->op_umask);
+			if (status)
+				goto out;
+			break;
+		default:
+			goto xdr_error;
+		}
+		break;
+	default:
+		goto xdr_error;
+	}
+
+	/* open_claim */
+	READ_BUF(4);
+	open->op_claim_type = be32_to_cpup(p++);
+	switch (open->op_claim_type) {
+	case NFS4_OPEN_CLAIM_NULL:
+	case NFS4_OPEN_CLAIM_DELEGATE_PREV:
+		READ_BUF(4);
+		open->op_fname.len = be32_to_cpup(p++);
+		READ_BUF(open->op_fname.len);
+		SAVEMEM(open->op_fname.data, open->op_fname.len);
+		if ((status = check_filename(open->op_fname.data, open->op_fname.len)))
+			return status;
+		break;
+	case NFS4_OPEN_CLAIM_PREVIOUS:
+		READ_BUF(4);
+		open->op_delegate_type = be32_to_cpup(p++);
+		break;
+	case NFS4_OPEN_CLAIM_DELEGATE_CUR:
+		status = nfsd4_decode_stateid(argp, &open->op_delegate_stateid);
+		if (status)
+			return status;
+		READ_BUF(4);
+		open->op_fname.len = be32_to_cpup(p++);
+		READ_BUF(open->op_fname.len);
+		SAVEMEM(open->op_fname.data, open->op_fname.len);
+		if ((status = check_filename(open->op_fname.data, open->op_fname.len)))
+			return status;
+		break;
+	case NFS4_OPEN_CLAIM_FH:
+	case NFS4_OPEN_CLAIM_DELEG_PREV_FH:
+		if (argp->minorversion < 1)
+			goto xdr_error;
+		/* void */
+		break;
+	case NFS4_OPEN_CLAIM_DELEG_CUR_FH:
+		if (argp->minorversion < 1)
+			goto xdr_error;
+		status = nfsd4_decode_stateid(argp, &open->op_delegate_stateid);
+		if (status)
+			return status;
+		break;
+	default:
+		goto xdr_error;
+	}
+
+	DECODE_TAIL;
+}
+
+static __be32
+nfsd4_decode_open_confirm(struct nfsd4_compoundargs *argp, struct nfsd4_open_confirm *open_conf)
+{
+	DECODE_HEAD;
+
+	if (argp->minorversion >= 1)
+		return nfserr_notsupp;
+
+	status = nfsd4_decode_stateid(argp, &open_conf->oc_req_stateid);
+	if (status)
+		return status;
+	READ_BUF(4);
+	open_conf->oc_seqid = be32_to_cpup(p++);
+
+	DECODE_TAIL;
+}
+
+static __be32
+nfsd4_decode_open_downgrade(struct nfsd4_compoundargs *argp, struct nfsd4_open_downgrade *open_down)
+{
+	DECODE_HEAD;
+		    
+	status = nfsd4_decode_stateid(argp, &open_down->od_stateid);
+	if (status)
+		return status;
+	READ_BUF(4);
+	open_down->od_seqid = be32_to_cpup(p++);
+	status = nfsd4_decode_share_access(argp, &open_down->od_share_access,
+					   &open_down->od_deleg_want, NULL);
+	if (status)
+		return status;
+	status = nfsd4_decode_share_deny(argp, &open_down->od_share_deny);
+	if (status)
+		return status;
+	DECODE_TAIL;
+}
+
+static __be32
+nfsd4_decode_putfh(struct nfsd4_compoundargs *argp, struct nfsd4_putfh *putfh)
+{
+	DECODE_HEAD;
+
+	READ_BUF(4);
+	putfh->pf_fhlen = be32_to_cpup(p++);
+	if (putfh->pf_fhlen > NFS4_FHSIZE)
+		goto xdr_error;
+	READ_BUF(putfh->pf_fhlen);
+	SAVEMEM(putfh->pf_fhval, putfh->pf_fhlen);
+
+	DECODE_TAIL;
+}
+
+static __be32
+nfsd4_decode_putpubfh(struct nfsd4_compoundargs *argp, void *p)
+{
+	if (argp->minorversion == 0)
+		return nfs_ok;
+	return nfserr_notsupp;
+}
+
+static __be32
+nfsd4_decode_read(struct nfsd4_compoundargs *argp, struct nfsd4_read *read)
+{
+	DECODE_HEAD;
+
+	status = nfsd4_decode_stateid(argp, &read->rd_stateid);
+	if (status)
+		return status;
+	READ_BUF(12);
+	p = xdr_decode_hyper(p, &read->rd_offset);
+	read->rd_length = be32_to_cpup(p++);
+
+	DECODE_TAIL;
+}
+
+static __be32
+nfsd4_decode_readdir(struct nfsd4_compoundargs *argp, struct nfsd4_readdir *readdir)
+{
+	DECODE_HEAD;
+
+	READ_BUF(24);
+	p = xdr_decode_hyper(p, &readdir->rd_cookie);
+	COPYMEM(readdir->rd_verf.data, sizeof(readdir->rd_verf.data));
+	readdir->rd_dircount = be32_to_cpup(p++);
+	readdir->rd_maxcount = be32_to_cpup(p++);
+	if ((status = nfsd4_decode_bitmap(argp, readdir->rd_bmval)))
+		goto out;
+
+	DECODE_TAIL;
+}
+
+static __be32
+nfsd4_decode_remove(struct nfsd4_compoundargs *argp, struct nfsd4_remove *remove)
+{
+	DECODE_HEAD;
+
+	READ_BUF(4);
+	remove->rm_namelen = be32_to_cpup(p++);
+	READ_BUF(remove->rm_namelen);
+	SAVEMEM(remove->rm_name, remove->rm_namelen);
+	if ((status = check_filename(remove->rm_name, remove->rm_namelen)))
+		return status;
+
+	DECODE_TAIL;
+}
+
+static __be32
+nfsd4_decode_rename(struct nfsd4_compoundargs *argp, struct nfsd4_rename *rename)
+{
+	DECODE_HEAD;
+
+	READ_BUF(4);
+	rename->rn_snamelen = be32_to_cpup(p++);
+	READ_BUF(rename->rn_snamelen);
+	SAVEMEM(rename->rn_sname, rename->rn_snamelen);
+	READ_BUF(4);
+	rename->rn_tnamelen = be32_to_cpup(p++);
+	READ_BUF(rename->rn_tnamelen);
+	SAVEMEM(rename->rn_tname, rename->rn_tnamelen);
+	if ((status = check_filename(rename->rn_sname, rename->rn_snamelen)))
+		return status;
+	if ((status = check_filename(rename->rn_tname, rename->rn_tnamelen)))
+		return status;
+
+	DECODE_TAIL;
+}
+
+static __be32
+nfsd4_decode_renew(struct nfsd4_compoundargs *argp, clientid_t *clientid)
+{
+	DECODE_HEAD;
+
+	if (argp->minorversion >= 1)
+		return nfserr_notsupp;
+
+	READ_BUF(sizeof(clientid_t));
+	COPYMEM(clientid, sizeof(clientid_t));
+
+	DECODE_TAIL;
+}
+
+static __be32
+nfsd4_decode_secinfo(struct nfsd4_compoundargs *argp,
+		     struct nfsd4_secinfo *secinfo)
+{
+	DECODE_HEAD;
+
+	READ_BUF(4);
+	secinfo->si_namelen = be32_to_cpup(p++);
+	READ_BUF(secinfo->si_namelen);
+	SAVEMEM(secinfo->si_name, secinfo->si_namelen);
+	status = check_filename(secinfo->si_name, secinfo->si_namelen);
+	if (status)
+		return status;
+	DECODE_TAIL;
+}
+
+static __be32
+nfsd4_decode_secinfo_no_name(struct nfsd4_compoundargs *argp,
+		     struct nfsd4_secinfo_no_name *sin)
+{
+	DECODE_HEAD;
+
+	READ_BUF(4);
+	sin->sin_style = be32_to_cpup(p++);
+	DECODE_TAIL;
+}
+
+static __be32
+nfsd4_decode_setattr(struct nfsd4_compoundargs *argp, struct nfsd4_setattr *setattr)
+{
+	__be32 status;
+
+	status = nfsd4_decode_stateid(argp, &setattr->sa_stateid);
+	if (status)
+		return status;
+	return nfsd4_decode_fattr(argp, setattr->sa_bmval, &setattr->sa_iattr,
+				  &setattr->sa_acl, &setattr->sa_label, NULL);
+}
+
+static __be32
+nfsd4_decode_setclientid(struct nfsd4_compoundargs *argp, struct nfsd4_setclientid *setclientid)
+{
+	DECODE_HEAD;
+
+	if (argp->minorversion >= 1)
+		return nfserr_notsupp;
+
+	READ_BUF(NFS4_VERIFIER_SIZE);
+	COPYMEM(setclientid->se_verf.data, NFS4_VERIFIER_SIZE);
+
+	status = nfsd4_decode_opaque(argp, &setclientid->se_name);
+	if (status)
+		return nfserr_bad_xdr;
+	READ_BUF(8);
+	setclientid->se_callback_prog = be32_to_cpup(p++);
+	setclientid->se_callback_netid_len = be32_to_cpup(p++);
+	READ_BUF(setclientid->se_callback_netid_len);
+	SAVEMEM(setclientid->se_callback_netid_val, setclientid->se_callback_netid_len);
+	READ_BUF(4);
+	setclientid->se_callback_addr_len = be32_to_cpup(p++);
+
+	READ_BUF(setclientid->se_callback_addr_len);
+	SAVEMEM(setclientid->se_callback_addr_val, setclientid->se_callback_addr_len);
+	READ_BUF(4);
+	setclientid->se_callback_ident = be32_to_cpup(p++);
+
+	DECODE_TAIL;
+}
+
+static __be32
+nfsd4_decode_setclientid_confirm(struct nfsd4_compoundargs *argp, struct nfsd4_setclientid_confirm *scd_c)
+{
+	DECODE_HEAD;
+
+	if (argp->minorversion >= 1)
+		return nfserr_notsupp;
+
+	READ_BUF(8 + NFS4_VERIFIER_SIZE);
+	COPYMEM(&scd_c->sc_clientid, 8);
+	COPYMEM(&scd_c->sc_confirm, NFS4_VERIFIER_SIZE);
+
+	DECODE_TAIL;
+}
+
+/* Also used for NVERIFY */
+static __be32
+nfsd4_decode_verify(struct nfsd4_compoundargs *argp, struct nfsd4_verify *verify)
+{
+	DECODE_HEAD;
+
+	if ((status = nfsd4_decode_bitmap(argp, verify->ve_bmval)))
+		goto out;
+
+	/* For convenience's sake, we compare raw xdr'd attributes in
+	 * nfsd4_proc_verify */
+
+	READ_BUF(4);
+	verify->ve_attrlen = be32_to_cpup(p++);
+	READ_BUF(verify->ve_attrlen);
+	SAVEMEM(verify->ve_attrval, verify->ve_attrlen);
+
+	DECODE_TAIL;
+}
+
+static __be32
+nfsd4_decode_write(struct nfsd4_compoundargs *argp, struct nfsd4_write *write)
+{
+	DECODE_HEAD;
+
+	status = nfsd4_decode_stateid(argp, &write->wr_stateid);
+	if (status)
+		return status;
+	READ_BUF(16);
+	p = xdr_decode_hyper(p, &write->wr_offset);
+	write->wr_stable_how = be32_to_cpup(p++);
+	if (write->wr_stable_how > NFS_FILE_SYNC)
+		goto xdr_error;
+	write->wr_buflen = be32_to_cpup(p++);
+
+	status = svcxdr_construct_vector(argp, &write->wr_head,
+					 &write->wr_pagelist, write->wr_buflen);
+	if (status)
+		return status;
+
+	DECODE_TAIL;
+}
+
+static __be32
+nfsd4_decode_release_lockowner(struct nfsd4_compoundargs *argp, struct nfsd4_release_lockowner *rlockowner)
+{
+	DECODE_HEAD;
+
+	if (argp->minorversion >= 1)
+		return nfserr_notsupp;
+
+	READ_BUF(12);
+	COPYMEM(&rlockowner->rl_clientid, sizeof(clientid_t));
+	rlockowner->rl_owner.len = be32_to_cpup(p++);
+	READ_BUF(rlockowner->rl_owner.len);
+	READMEM(rlockowner->rl_owner.data, rlockowner->rl_owner.len);
+
+	if (argp->minorversion && !zero_clientid(&rlockowner->rl_clientid))
+		return nfserr_inval;
+	DECODE_TAIL;
+}
+
+static __be32
+nfsd4_decode_exchange_id(struct nfsd4_compoundargs *argp,
+			 struct nfsd4_exchange_id *exid)
+{
+	int dummy, tmp;
+	DECODE_HEAD;
+
+	READ_BUF(NFS4_VERIFIER_SIZE);
+	COPYMEM(exid->verifier.data, NFS4_VERIFIER_SIZE);
+
+	status = nfsd4_decode_opaque(argp, &exid->clname);
+	if (status)
+		return nfserr_bad_xdr;
+
+	READ_BUF(4);
+	exid->flags = be32_to_cpup(p++);
+
+	/* Ignore state_protect4_a */
+	READ_BUF(4);
+	exid->spa_how = be32_to_cpup(p++);
+	switch (exid->spa_how) {
+	case SP4_NONE:
+		break;
+	case SP4_MACH_CRED:
+		/* spo_must_enforce */
+		status = nfsd4_decode_bitmap(argp,
+					exid->spo_must_enforce);
+		if (status)
+			goto out;
+		/* spo_must_allow */
+		status = nfsd4_decode_bitmap(argp, exid->spo_must_allow);
+		if (status)
+			goto out;
+		break;
+	case SP4_SSV:
+		/* ssp_ops */
+		READ_BUF(4);
+		dummy = be32_to_cpup(p++);
+		READ_BUF(dummy * 4);
+		p += dummy;
+
+		READ_BUF(4);
+		dummy = be32_to_cpup(p++);
+		READ_BUF(dummy * 4);
+		p += dummy;
+
+		/* ssp_hash_algs<> */
+		READ_BUF(4);
+		tmp = be32_to_cpup(p++);
+		while (tmp--) {
+			READ_BUF(4);
+			dummy = be32_to_cpup(p++);
+			READ_BUF(dummy);
+			p += XDR_QUADLEN(dummy);
+		}
+
+		/* ssp_encr_algs<> */
+		READ_BUF(4);
+		tmp = be32_to_cpup(p++);
+		while (tmp--) {
+			READ_BUF(4);
+			dummy = be32_to_cpup(p++);
+			READ_BUF(dummy);
+			p += XDR_QUADLEN(dummy);
+		}
+
+		/* ignore ssp_window and ssp_num_gss_handles: */
+		READ_BUF(8);
+		break;
+	default:
+		goto xdr_error;
+	}
+
+	READ_BUF(4);    /* nfs_impl_id4 array length */
+	dummy = be32_to_cpup(p++);
+
+	if (dummy > 1)
+		goto xdr_error;
+
+	if (dummy == 1) {
+		status = nfsd4_decode_opaque(argp, &exid->nii_domain);
+		if (status)
+			goto xdr_error;
+
+		/* nii_name */
+		status = nfsd4_decode_opaque(argp, &exid->nii_name);
+		if (status)
+			goto xdr_error;
+
+		/* nii_date */
+		status = nfsd4_decode_time(argp, &exid->nii_time);
+		if (status)
+			goto xdr_error;
+	}
+	DECODE_TAIL;
+}
+
+static __be32
+nfsd4_decode_create_session(struct nfsd4_compoundargs *argp,
+			    struct nfsd4_create_session *sess)
+{
+	DECODE_HEAD;
+
+	READ_BUF(16);
+	COPYMEM(&sess->clientid, 8);
+	sess->seqid = be32_to_cpup(p++);
+	sess->flags = be32_to_cpup(p++);
+
+	/* Fore channel attrs */
+	READ_BUF(28);
+	p++; /* headerpadsz is always 0 */
+	sess->fore_channel.maxreq_sz = be32_to_cpup(p++);
+	sess->fore_channel.maxresp_sz = be32_to_cpup(p++);
+	sess->fore_channel.maxresp_cached = be32_to_cpup(p++);
+	sess->fore_channel.maxops = be32_to_cpup(p++);
+	sess->fore_channel.maxreqs = be32_to_cpup(p++);
+	sess->fore_channel.nr_rdma_attrs = be32_to_cpup(p++);
+	if (sess->fore_channel.nr_rdma_attrs == 1) {
+		READ_BUF(4);
+		sess->fore_channel.rdma_attrs = be32_to_cpup(p++);
+	} else if (sess->fore_channel.nr_rdma_attrs > 1) {
+		dprintk("Too many fore channel attr bitmaps!\n");
+		goto xdr_error;
+	}
+
+	/* Back channel attrs */
+	READ_BUF(28);
+	p++; /* headerpadsz is always 0 */
+	sess->back_channel.maxreq_sz = be32_to_cpup(p++);
+	sess->back_channel.maxresp_sz = be32_to_cpup(p++);
+	sess->back_channel.maxresp_cached = be32_to_cpup(p++);
+	sess->back_channel.maxops = be32_to_cpup(p++);
+	sess->back_channel.maxreqs = be32_to_cpup(p++);
+	sess->back_channel.nr_rdma_attrs = be32_to_cpup(p++);
+	if (sess->back_channel.nr_rdma_attrs == 1) {
+		READ_BUF(4);
+		sess->back_channel.rdma_attrs = be32_to_cpup(p++);
+	} else if (sess->back_channel.nr_rdma_attrs > 1) {
+		dprintk("Too many back channel attr bitmaps!\n");
+		goto xdr_error;
+	}
+
+	READ_BUF(4);
+	sess->callback_prog = be32_to_cpup(p++);
+	nfsd4_decode_cb_sec(argp, &sess->cb_sec);
+	DECODE_TAIL;
+}
+
+static __be32
+nfsd4_decode_destroy_session(struct nfsd4_compoundargs *argp,
+			     struct nfsd4_destroy_session *destroy_session)
+{
+	DECODE_HEAD;
+	READ_BUF(NFS4_MAX_SESSIONID_LEN);
+	COPYMEM(destroy_session->sessionid.data, NFS4_MAX_SESSIONID_LEN);
+
+	DECODE_TAIL;
+}
+
+static __be32
+nfsd4_decode_free_stateid(struct nfsd4_compoundargs *argp,
+			  struct nfsd4_free_stateid *free_stateid)
+{
+	DECODE_HEAD;
+
+	READ_BUF(sizeof(stateid_t));
+	free_stateid->fr_stateid.si_generation = be32_to_cpup(p++);
+	COPYMEM(&free_stateid->fr_stateid.si_opaque, sizeof(stateid_opaque_t));
+
+	DECODE_TAIL;
+}
+
+static __be32
+nfsd4_decode_sequence(struct nfsd4_compoundargs *argp,
+		      struct nfsd4_sequence *seq)
+{
+	DECODE_HEAD;
+
+	READ_BUF(NFS4_MAX_SESSIONID_LEN + 16);
+	COPYMEM(seq->sessionid.data, NFS4_MAX_SESSIONID_LEN);
+	seq->seqid = be32_to_cpup(p++);
+	seq->slotid = be32_to_cpup(p++);
+	seq->maxslots = be32_to_cpup(p++);
+	seq->cachethis = be32_to_cpup(p++);
+
+	DECODE_TAIL;
+}
+
+static __be32
+nfsd4_decode_test_stateid(struct nfsd4_compoundargs *argp, struct nfsd4_test_stateid *test_stateid)
+{
+	int i;
+	__be32 *p, status;
+	struct nfsd4_test_stateid_id *stateid;
+
+	READ_BUF(4);
+	test_stateid->ts_num_ids = ntohl(*p++);
+
+	INIT_LIST_HEAD(&test_stateid->ts_stateid_list);
+
+	for (i = 0; i < test_stateid->ts_num_ids; i++) {
+		stateid = svcxdr_tmpalloc(argp, sizeof(*stateid));
+		if (!stateid) {
+			status = nfserrno(-ENOMEM);
+			goto out;
+		}
+
+		INIT_LIST_HEAD(&stateid->ts_id_list);
+		list_add_tail(&stateid->ts_id_list, &test_stateid->ts_stateid_list);
+
+		status = nfsd4_decode_stateid(argp, &stateid->ts_id_stateid);
+		if (status)
+			goto out;
+	}
+
+	status = 0;
+out:
+	return status;
+xdr_error:
+	dprintk("NFSD: xdr error (%s:%d)\n", __FILE__, __LINE__);
+	status = nfserr_bad_xdr;
+	goto out;
+}
+
+static __be32 nfsd4_decode_destroy_clientid(struct nfsd4_compoundargs *argp, struct nfsd4_destroy_clientid *dc)
+{
+	DECODE_HEAD;
+
+	READ_BUF(8);
+	COPYMEM(&dc->clientid, 8);
+
+	DECODE_TAIL;
+}
+
+static __be32 nfsd4_decode_reclaim_complete(struct nfsd4_compoundargs *argp, struct nfsd4_reclaim_complete *rc)
+{
+	DECODE_HEAD;
+
+	READ_BUF(4);
+	rc->rca_one_fs = be32_to_cpup(p++);
+
+	DECODE_TAIL;
+}
+
+#ifdef CONFIG_NFSD_PNFS
+static __be32
+nfsd4_decode_getdeviceinfo(struct nfsd4_compoundargs *argp,
+		struct nfsd4_getdeviceinfo *gdev)
+{
+	DECODE_HEAD;
+	u32 num, i;
+
+	READ_BUF(sizeof(struct nfsd4_deviceid) + 3 * 4);
+	COPYMEM(&gdev->gd_devid, sizeof(struct nfsd4_deviceid));
+	gdev->gd_layout_type = be32_to_cpup(p++);
+	gdev->gd_maxcount = be32_to_cpup(p++);
+	num = be32_to_cpup(p++);
+	if (num) {
+		if (num > 1000)
+			goto xdr_error;
+		READ_BUF(4 * num);
+		gdev->gd_notify_types = be32_to_cpup(p++);
+		for (i = 1; i < num; i++) {
+			if (be32_to_cpup(p++)) {
+				status = nfserr_inval;
+				goto out;
+			}
+		}
+	}
+	DECODE_TAIL;
+}
+
+static __be32
+nfsd4_decode_layoutget(struct nfsd4_compoundargs *argp,
+		struct nfsd4_layoutget *lgp)
+{
+	DECODE_HEAD;
+
+	READ_BUF(36);
+	lgp->lg_signal = be32_to_cpup(p++);
+	lgp->lg_layout_type = be32_to_cpup(p++);
+	lgp->lg_seg.iomode = be32_to_cpup(p++);
+	p = xdr_decode_hyper(p, &lgp->lg_seg.offset);
+	p = xdr_decode_hyper(p, &lgp->lg_seg.length);
+	p = xdr_decode_hyper(p, &lgp->lg_minlength);
+
+	status = nfsd4_decode_stateid(argp, &lgp->lg_sid);
+	if (status)
+		return status;
+
+	READ_BUF(4);
+	lgp->lg_maxcount = be32_to_cpup(p++);
+
+	DECODE_TAIL;
+}
+
+static __be32
+nfsd4_decode_layoutcommit(struct nfsd4_compoundargs *argp,
+		struct nfsd4_layoutcommit *lcp)
+{
+	DECODE_HEAD;
+	u32 timechange;
+
+	READ_BUF(20);
+	p = xdr_decode_hyper(p, &lcp->lc_seg.offset);
+	p = xdr_decode_hyper(p, &lcp->lc_seg.length);
+	lcp->lc_reclaim = be32_to_cpup(p++);
+
+	status = nfsd4_decode_stateid(argp, &lcp->lc_sid);
+	if (status)
+		return status;
+
+	READ_BUF(4);
+	lcp->lc_newoffset = be32_to_cpup(p++);
+	if (lcp->lc_newoffset) {
+		READ_BUF(8);
+		p = xdr_decode_hyper(p, &lcp->lc_last_wr);
+	} else
+		lcp->lc_last_wr = 0;
+	READ_BUF(4);
+	timechange = be32_to_cpup(p++);
+	if (timechange) {
+		status = nfsd4_decode_time(argp, &lcp->lc_mtime);
+		if (status)
+			return status;
+	} else {
+		lcp->lc_mtime.tv_nsec = UTIME_NOW;
+	}
+	READ_BUF(8);
+	lcp->lc_layout_type = be32_to_cpup(p++);
+
+	/*
+	 * Save the layout update in XDR format and let the layout driver deal
+	 * with it later.
+	 */
+	lcp->lc_up_len = be32_to_cpup(p++);
+	if (lcp->lc_up_len > 0) {
+		READ_BUF(lcp->lc_up_len);
+		READMEM(lcp->lc_up_layout, lcp->lc_up_len);
+	}
+
+	DECODE_TAIL;
+}
+
+static __be32
+nfsd4_decode_layoutreturn(struct nfsd4_compoundargs *argp,
+		struct nfsd4_layoutreturn *lrp)
+{
+	DECODE_HEAD;
+
+	READ_BUF(16);
+	lrp->lr_reclaim = be32_to_cpup(p++);
+	lrp->lr_layout_type = be32_to_cpup(p++);
+	lrp->lr_seg.iomode = be32_to_cpup(p++);
+	lrp->lr_return_type = be32_to_cpup(p++);
+	if (lrp->lr_return_type == RETURN_FILE) {
+		READ_BUF(16);
+		p = xdr_decode_hyper(p, &lrp->lr_seg.offset);
+		p = xdr_decode_hyper(p, &lrp->lr_seg.length);
+
+		status = nfsd4_decode_stateid(argp, &lrp->lr_sid);
+		if (status)
+			return status;
+
+		READ_BUF(4);
+		lrp->lrf_body_len = be32_to_cpup(p++);
+		if (lrp->lrf_body_len > 0) {
+			READ_BUF(lrp->lrf_body_len);
+			READMEM(lrp->lrf_body, lrp->lrf_body_len);
+		}
+	} else {
+		lrp->lr_seg.offset = 0;
+		lrp->lr_seg.length = NFS4_MAX_UINT64;
+	}
+
+	DECODE_TAIL;
+}
+#endif /* CONFIG_NFSD_PNFS */
+
+static __be32
+nfsd4_decode_fallocate(struct nfsd4_compoundargs *argp,
+		       struct nfsd4_fallocate *fallocate)
+{
+	DECODE_HEAD;
+
+	status = nfsd4_decode_stateid(argp, &fallocate->falloc_stateid);
+	if (status)
+		return status;
+
+	READ_BUF(16);
+	p = xdr_decode_hyper(p, &fallocate->falloc_offset);
+	xdr_decode_hyper(p, &fallocate->falloc_length);
+
+	DECODE_TAIL;
+}
+
+static __be32
+nfsd4_decode_clone(struct nfsd4_compoundargs *argp, struct nfsd4_clone *clone)
+{
+	DECODE_HEAD;
+
+	status = nfsd4_decode_stateid(argp, &clone->cl_src_stateid);
+	if (status)
+		return status;
+	status = nfsd4_decode_stateid(argp, &clone->cl_dst_stateid);
+	if (status)
+		return status;
+
+	READ_BUF(8 + 8 + 8);
+	p = xdr_decode_hyper(p, &clone->cl_src_pos);
+	p = xdr_decode_hyper(p, &clone->cl_dst_pos);
+	p = xdr_decode_hyper(p, &clone->cl_count);
+	DECODE_TAIL;
+}
+
+static __be32 nfsd4_decode_nl4_server(struct nfsd4_compoundargs *argp,
+				      struct nl4_server *ns)
+{
+	DECODE_HEAD;
+	struct nfs42_netaddr *naddr;
+
+	READ_BUF(4);
+	ns->nl4_type = be32_to_cpup(p++);
+
+	/* currently support for 1 inter-server source server */
+	switch (ns->nl4_type) {
+	case NL4_NETADDR:
+		naddr = &ns->u.nl4_addr;
+
+		READ_BUF(4);
+		naddr->netid_len = be32_to_cpup(p++);
+		if (naddr->netid_len > RPCBIND_MAXNETIDLEN)
+			goto xdr_error;
+
+		READ_BUF(naddr->netid_len + 4); /* 4 for uaddr len */
+		COPYMEM(naddr->netid, naddr->netid_len);
+
+		naddr->addr_len = be32_to_cpup(p++);
+		if (naddr->addr_len > RPCBIND_MAXUADDRLEN)
+			goto xdr_error;
+
+		READ_BUF(naddr->addr_len);
+		COPYMEM(naddr->addr, naddr->addr_len);
+		break;
+	default:
+		goto xdr_error;
+	}
+	DECODE_TAIL;
+}
+
+static __be32
+nfsd4_decode_copy(struct nfsd4_compoundargs *argp, struct nfsd4_copy *copy)
+{
+	DECODE_HEAD;
+	struct nl4_server *ns_dummy;
+	int i, count;
+
+	status = nfsd4_decode_stateid(argp, &copy->cp_src_stateid);
+	if (status)
+		return status;
+	status = nfsd4_decode_stateid(argp, &copy->cp_dst_stateid);
+	if (status)
+		return status;
+
+	READ_BUF(8 + 8 + 8 + 4 + 4 + 4);
+	p = xdr_decode_hyper(p, &copy->cp_src_pos);
+	p = xdr_decode_hyper(p, &copy->cp_dst_pos);
+	p = xdr_decode_hyper(p, &copy->cp_count);
+	p++; /* ca_consecutive: we always do consecutive copies */
+	copy->cp_synchronous = be32_to_cpup(p++);
+
+	count = be32_to_cpup(p++);
+
+	copy->cp_intra = false;
+	if (count == 0) { /* intra-server copy */
+		copy->cp_intra = true;
+		goto intra;
+	}
+
+	/* decode all the supplied server addresses but use first */
+	status = nfsd4_decode_nl4_server(argp, &copy->cp_src);
+	if (status)
+		return status;
+
+	ns_dummy = kmalloc(sizeof(struct nl4_server), GFP_KERNEL);
+	if (ns_dummy == NULL)
+		return nfserrno(-ENOMEM);
+	for (i = 0; i < count - 1; i++) {
+		status = nfsd4_decode_nl4_server(argp, ns_dummy);
+		if (status) {
+			kfree(ns_dummy);
+			return status;
+		}
+	}
+	kfree(ns_dummy);
+intra:
+
+	DECODE_TAIL;
+}
+
+static __be32
+nfsd4_decode_offload_status(struct nfsd4_compoundargs *argp,
+			    struct nfsd4_offload_status *os)
+{
+	return nfsd4_decode_stateid(argp, &os->stateid);
+}
+
+static __be32
+nfsd4_decode_copy_notify(struct nfsd4_compoundargs *argp,
+			 struct nfsd4_copy_notify *cn)
+{
+	__be32 status;
+
+	status = nfsd4_decode_stateid(argp, &cn->cpn_src_stateid);
+	if (status)
+		return status;
+	return nfsd4_decode_nl4_server(argp, &cn->cpn_dst);
+}
+
+static __be32
+nfsd4_decode_seek(struct nfsd4_compoundargs *argp, struct nfsd4_seek *seek)
+{
+	DECODE_HEAD;
+
+	status = nfsd4_decode_stateid(argp, &seek->seek_stateid);
+	if (status)
+		return status;
+
+	READ_BUF(8 + 4);
+	p = xdr_decode_hyper(p, &seek->seek_offset);
+	seek->seek_whence = be32_to_cpup(p);
+
+	DECODE_TAIL;
+}
+
+/*
+ * XDR data that is more than PAGE_SIZE in size is normally part of a
+ * read or write. However, the size of extended attributes is limited
+ * by the maximum request size, and then further limited by the underlying
+ * filesystem limits. This can exceed PAGE_SIZE (currently, XATTR_SIZE_MAX
+ * is 64k). Since there is no kvec- or page-based interface to xattrs,
+ * and we're not dealing with contiguous pages, we need to do some copying.
+ */
+
+/*
+ * Decode data into buffer. Uses head and pages constructed by
+ * svcxdr_construct_vector.
+ */
+static __be32
+nfsd4_vbuf_from_vector(struct nfsd4_compoundargs *argp, struct kvec *head,
+		       struct page **pages, char **bufp, u32 buflen)
+{
+	char *tmp, *dp;
+	u32 len;
+
+	if (buflen <= head->iov_len) {
+		/*
+		 * We're in luck, the head has enough space. Just return
+		 * the head, no need for copying.
+		 */
+		*bufp = head->iov_base;
+		return 0;
+	}
+
+	tmp = svcxdr_tmpalloc(argp, buflen);
+	if (tmp == NULL)
+		return nfserr_jukebox;
+
+	dp = tmp;
+	memcpy(dp, head->iov_base, head->iov_len);
+	buflen -= head->iov_len;
+	dp += head->iov_len;
+
+	while (buflen > 0) {
+		len = min_t(u32, buflen, PAGE_SIZE);
+		memcpy(dp, page_address(*pages), len);
+
+		buflen -= len;
+		dp += len;
+		pages++;
+	}
+
+	*bufp = tmp;
+	return 0;
+}
+
+/*
+ * Get a user extended attribute name from the XDR buffer.
+ * It will not have the "user." prefix, so prepend it.
+ * Lastly, check for nul characters in the name.
+ */
+static __be32
+nfsd4_decode_xattr_name(struct nfsd4_compoundargs *argp, char **namep)
+{
+	DECODE_HEAD;
+	char *name, *sp, *dp;
+	u32 namelen, cnt;
+
+	READ_BUF(4);
+	namelen = be32_to_cpup(p++);
+
+	if (namelen > (XATTR_NAME_MAX - XATTR_USER_PREFIX_LEN))
+		return nfserr_nametoolong;
+
+	if (namelen == 0)
+		goto xdr_error;
+
+	READ_BUF(namelen);
+
+	name = svcxdr_tmpalloc(argp, namelen + XATTR_USER_PREFIX_LEN + 1);
+	if (!name)
+		return nfserr_jukebox;
+
+	memcpy(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN);
+
+	/*
+	 * Copy the extended attribute name over while checking for 0
+	 * characters.
+	 */
+	sp = (char *)p;
+	dp = name + XATTR_USER_PREFIX_LEN;
+	cnt = namelen;
+
+	while (cnt-- > 0) {
+		if (*sp == '\0')
+			goto xdr_error;
+		*dp++ = *sp++;
+	}
+	*dp = '\0';
+
+	*namep = name;
+
+	DECODE_TAIL;
+}
+
+/*
+ * A GETXATTR op request comes without a length specifier. We just set the
+ * maximum length for the reply based on XATTR_SIZE_MAX and the maximum
+ * channel reply size. nfsd_getxattr will probe the length of the xattr,
+ * check it against getxa_len, and allocate + return the value.
+ */
+static __be32
+nfsd4_decode_getxattr(struct nfsd4_compoundargs *argp,
+		      struct nfsd4_getxattr *getxattr)
+{
+	__be32 status;
+	u32 maxcount;
+
+	status = nfsd4_decode_xattr_name(argp, &getxattr->getxa_name);
+	if (status)
+		return status;
+
+	maxcount = svc_max_payload(argp->rqstp);
+	maxcount = min_t(u32, XATTR_SIZE_MAX, maxcount);
+
+	getxattr->getxa_len = maxcount;
+
+	return status;
+}
+
+static __be32
+nfsd4_decode_setxattr(struct nfsd4_compoundargs *argp,
+		      struct nfsd4_setxattr *setxattr)
+{
+	DECODE_HEAD;
+	u32 flags, maxcount, size;
+	struct kvec head;
+	struct page **pagelist;
+
+	READ_BUF(4);
+	flags = be32_to_cpup(p++);
+
+	if (flags > SETXATTR4_REPLACE)
+		return nfserr_inval;
+	setxattr->setxa_flags = flags;
+
+	status = nfsd4_decode_xattr_name(argp, &setxattr->setxa_name);
+	if (status)
+		return status;
+
+	maxcount = svc_max_payload(argp->rqstp);
+	maxcount = min_t(u32, XATTR_SIZE_MAX, maxcount);
+
+	READ_BUF(4);
+	size = be32_to_cpup(p++);
+	if (size > maxcount)
+		return nfserr_xattr2big;
+
+	setxattr->setxa_len = size;
+	if (size > 0) {
+		status = svcxdr_construct_vector(argp, &head, &pagelist, size);
+		if (status)
+			return status;
+
+		status = nfsd4_vbuf_from_vector(argp, &head, pagelist,
+		    &setxattr->setxa_buf, size);
+	}
+
+	DECODE_TAIL;
+}
+
+static __be32
+nfsd4_decode_listxattrs(struct nfsd4_compoundargs *argp,
+			struct nfsd4_listxattrs *listxattrs)
+{
+	DECODE_HEAD;
+	u32 maxcount;
+
+	READ_BUF(12);
+	p = xdr_decode_hyper(p, &listxattrs->lsxa_cookie);
+
+	/*
+	 * If the cookie  is too large to have even one user.x attribute
+	 * plus trailing '\0' left in a maximum size buffer, it's invalid.
+	 */
+	if (listxattrs->lsxa_cookie >=
+	    (XATTR_LIST_MAX / (XATTR_USER_PREFIX_LEN + 2)))
+		return nfserr_badcookie;
+
+	maxcount = be32_to_cpup(p++);
+	if (maxcount < 8)
+		/* Always need at least 2 words (length and one character) */
+		return nfserr_inval;
+
+	maxcount = min(maxcount, svc_max_payload(argp->rqstp));
+	listxattrs->lsxa_maxcount = maxcount;
+
+	DECODE_TAIL;
+}
+
+static __be32
+nfsd4_decode_removexattr(struct nfsd4_compoundargs *argp,
+			 struct nfsd4_removexattr *removexattr)
+{
+	return nfsd4_decode_xattr_name(argp, &removexattr->rmxa_name);
+}
+
+static __be32
+nfsd4_decode_noop(struct nfsd4_compoundargs *argp, void *p)
+{
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_notsupp(struct nfsd4_compoundargs *argp, void *p)
+{
+	return nfserr_notsupp;
+}
+
+typedef __be32(*nfsd4_dec)(struct nfsd4_compoundargs *argp, void *);
+
+static const nfsd4_dec nfsd4_dec_ops[] = {
+	[OP_ACCESS]		= (nfsd4_dec)nfsd4_decode_access,
+	[OP_CLOSE]		= (nfsd4_dec)nfsd4_decode_close,
+	[OP_COMMIT]		= (nfsd4_dec)nfsd4_decode_commit,
+	[OP_CREATE]		= (nfsd4_dec)nfsd4_decode_create,
+	[OP_DELEGPURGE]		= (nfsd4_dec)nfsd4_decode_notsupp,
+	[OP_DELEGRETURN]	= (nfsd4_dec)nfsd4_decode_delegreturn,
+	[OP_GETATTR]		= (nfsd4_dec)nfsd4_decode_getattr,
+	[OP_GETFH]		= (nfsd4_dec)nfsd4_decode_noop,
+	[OP_LINK]		= (nfsd4_dec)nfsd4_decode_link,
+	[OP_LOCK]		= (nfsd4_dec)nfsd4_decode_lock,
+	[OP_LOCKT]		= (nfsd4_dec)nfsd4_decode_lockt,
+	[OP_LOCKU]		= (nfsd4_dec)nfsd4_decode_locku,
+	[OP_LOOKUP]		= (nfsd4_dec)nfsd4_decode_lookup,
+	[OP_LOOKUPP]		= (nfsd4_dec)nfsd4_decode_noop,
+	[OP_NVERIFY]		= (nfsd4_dec)nfsd4_decode_verify,
+	[OP_OPEN]		= (nfsd4_dec)nfsd4_decode_open,
+	[OP_OPENATTR]		= (nfsd4_dec)nfsd4_decode_notsupp,
+	[OP_OPEN_CONFIRM]	= (nfsd4_dec)nfsd4_decode_open_confirm,
+	[OP_OPEN_DOWNGRADE]	= (nfsd4_dec)nfsd4_decode_open_downgrade,
+	[OP_PUTFH]		= (nfsd4_dec)nfsd4_decode_putfh,
+	[OP_PUTPUBFH]		= (nfsd4_dec)nfsd4_decode_putpubfh,
+	[OP_PUTROOTFH]		= (nfsd4_dec)nfsd4_decode_noop,
+	[OP_READ]		= (nfsd4_dec)nfsd4_decode_read,
+	[OP_READDIR]		= (nfsd4_dec)nfsd4_decode_readdir,
+	[OP_READLINK]		= (nfsd4_dec)nfsd4_decode_noop,
+	[OP_REMOVE]		= (nfsd4_dec)nfsd4_decode_remove,
+	[OP_RENAME]		= (nfsd4_dec)nfsd4_decode_rename,
+	[OP_RENEW]		= (nfsd4_dec)nfsd4_decode_renew,
+	[OP_RESTOREFH]		= (nfsd4_dec)nfsd4_decode_noop,
+	[OP_SAVEFH]		= (nfsd4_dec)nfsd4_decode_noop,
+	[OP_SECINFO]		= (nfsd4_dec)nfsd4_decode_secinfo,
+	[OP_SETATTR]		= (nfsd4_dec)nfsd4_decode_setattr,
+	[OP_SETCLIENTID]	= (nfsd4_dec)nfsd4_decode_setclientid,
+	[OP_SETCLIENTID_CONFIRM] = (nfsd4_dec)nfsd4_decode_setclientid_confirm,
+	[OP_VERIFY]		= (nfsd4_dec)nfsd4_decode_verify,
+	[OP_WRITE]		= (nfsd4_dec)nfsd4_decode_write,
+	[OP_RELEASE_LOCKOWNER]	= (nfsd4_dec)nfsd4_decode_release_lockowner,
+
+	/* new operations for NFSv4.1 */
+	[OP_BACKCHANNEL_CTL]	= (nfsd4_dec)nfsd4_decode_backchannel_ctl,
+	[OP_BIND_CONN_TO_SESSION]= (nfsd4_dec)nfsd4_decode_bind_conn_to_session,
+	[OP_EXCHANGE_ID]	= (nfsd4_dec)nfsd4_decode_exchange_id,
+	[OP_CREATE_SESSION]	= (nfsd4_dec)nfsd4_decode_create_session,
+	[OP_DESTROY_SESSION]	= (nfsd4_dec)nfsd4_decode_destroy_session,
+	[OP_FREE_STATEID]	= (nfsd4_dec)nfsd4_decode_free_stateid,
+	[OP_GET_DIR_DELEGATION]	= (nfsd4_dec)nfsd4_decode_notsupp,
+#ifdef CONFIG_NFSD_PNFS
+	[OP_GETDEVICEINFO]	= (nfsd4_dec)nfsd4_decode_getdeviceinfo,
+	[OP_GETDEVICELIST]	= (nfsd4_dec)nfsd4_decode_notsupp,
+	[OP_LAYOUTCOMMIT]	= (nfsd4_dec)nfsd4_decode_layoutcommit,
+	[OP_LAYOUTGET]		= (nfsd4_dec)nfsd4_decode_layoutget,
+	[OP_LAYOUTRETURN]	= (nfsd4_dec)nfsd4_decode_layoutreturn,
+#else
+	[OP_GETDEVICEINFO]	= (nfsd4_dec)nfsd4_decode_notsupp,
+	[OP_GETDEVICELIST]	= (nfsd4_dec)nfsd4_decode_notsupp,
+	[OP_LAYOUTCOMMIT]	= (nfsd4_dec)nfsd4_decode_notsupp,
+	[OP_LAYOUTGET]		= (nfsd4_dec)nfsd4_decode_notsupp,
+	[OP_LAYOUTRETURN]	= (nfsd4_dec)nfsd4_decode_notsupp,
+#endif
+	[OP_SECINFO_NO_NAME]	= (nfsd4_dec)nfsd4_decode_secinfo_no_name,
+	[OP_SEQUENCE]		= (nfsd4_dec)nfsd4_decode_sequence,
+	[OP_SET_SSV]		= (nfsd4_dec)nfsd4_decode_notsupp,
+	[OP_TEST_STATEID]	= (nfsd4_dec)nfsd4_decode_test_stateid,
+	[OP_WANT_DELEGATION]	= (nfsd4_dec)nfsd4_decode_notsupp,
+	[OP_DESTROY_CLIENTID]	= (nfsd4_dec)nfsd4_decode_destroy_clientid,
+	[OP_RECLAIM_COMPLETE]	= (nfsd4_dec)nfsd4_decode_reclaim_complete,
+
+	/* new operations for NFSv4.2 */
+	[OP_ALLOCATE]		= (nfsd4_dec)nfsd4_decode_fallocate,
+	[OP_COPY]		= (nfsd4_dec)nfsd4_decode_copy,
+	[OP_COPY_NOTIFY]	= (nfsd4_dec)nfsd4_decode_copy_notify,
+	[OP_DEALLOCATE]		= (nfsd4_dec)nfsd4_decode_fallocate,
+	[OP_IO_ADVISE]		= (nfsd4_dec)nfsd4_decode_notsupp,
+	[OP_LAYOUTERROR]	= (nfsd4_dec)nfsd4_decode_notsupp,
+	[OP_LAYOUTSTATS]	= (nfsd4_dec)nfsd4_decode_notsupp,
+	[OP_OFFLOAD_CANCEL]	= (nfsd4_dec)nfsd4_decode_offload_status,
+	[OP_OFFLOAD_STATUS]	= (nfsd4_dec)nfsd4_decode_offload_status,
+	[OP_READ_PLUS]		= (nfsd4_dec)nfsd4_decode_read,
+	[OP_SEEK]		= (nfsd4_dec)nfsd4_decode_seek,
+	[OP_WRITE_SAME]		= (nfsd4_dec)nfsd4_decode_notsupp,
+	[OP_CLONE]		= (nfsd4_dec)nfsd4_decode_clone,
+	/* RFC 8276 extended atributes operations */
+	[OP_GETXATTR]		= (nfsd4_dec)nfsd4_decode_getxattr,
+	[OP_SETXATTR]		= (nfsd4_dec)nfsd4_decode_setxattr,
+	[OP_LISTXATTRS]		= (nfsd4_dec)nfsd4_decode_listxattrs,
+	[OP_REMOVEXATTR]	= (nfsd4_dec)nfsd4_decode_removexattr,
+};
+
+static inline bool
+nfsd4_opnum_in_range(struct nfsd4_compoundargs *argp, struct nfsd4_op *op)
+{
+	if (op->opnum < FIRST_NFS4_OP)
+		return false;
+	else if (argp->minorversion == 0 && op->opnum > LAST_NFS40_OP)
+		return false;
+	else if (argp->minorversion == 1 && op->opnum > LAST_NFS41_OP)
+		return false;
+	else if (argp->minorversion == 2 && op->opnum > LAST_NFS42_OP)
+		return false;
+	return true;
+}
+
+static __be32
+nfsd4_decode_compound(struct nfsd4_compoundargs *argp)
+{
+	DECODE_HEAD;
+	struct nfsd4_op *op;
+	bool cachethis = false;
+	int auth_slack= argp->rqstp->rq_auth_slack;
+	int max_reply = auth_slack + 8; /* opcnt, status */
+	int readcount = 0;
+	int readbytes = 0;
+	int i;
+
+	READ_BUF(4);
+	argp->taglen = be32_to_cpup(p++);
+	READ_BUF(argp->taglen);
+	SAVEMEM(argp->tag, argp->taglen);
+	READ_BUF(8);
+	argp->minorversion = be32_to_cpup(p++);
+	argp->opcnt = be32_to_cpup(p++);
+	max_reply += 4 + (XDR_QUADLEN(argp->taglen) << 2);
+
+	if (argp->taglen > NFSD4_MAX_TAGLEN)
+		goto xdr_error;
+	/*
+	 * NFS4ERR_RESOURCE is a more helpful error than GARBAGE_ARGS
+	 * here, so we return success at the xdr level so that
+	 * nfsd4_proc can handle this is an NFS-level error.
+	 */
+	if (argp->opcnt > NFSD_MAX_OPS_PER_COMPOUND)
+		return 0;
+
+	if (argp->opcnt > ARRAY_SIZE(argp->iops)) {
+		argp->ops = kzalloc(argp->opcnt * sizeof(*argp->ops), GFP_KERNEL);
+		if (!argp->ops) {
+			argp->ops = argp->iops;
+			dprintk("nfsd: couldn't allocate room for COMPOUND\n");
+			goto xdr_error;
+		}
+	}
+
+	if (argp->minorversion > NFSD_SUPPORTED_MINOR_VERSION)
+		argp->opcnt = 0;
+
+	for (i = 0; i < argp->opcnt; i++) {
+		op = &argp->ops[i];
+		op->replay = NULL;
+
+		READ_BUF(4);
+		op->opnum = be32_to_cpup(p++);
+
+		if (nfsd4_opnum_in_range(argp, op))
+			op->status = nfsd4_dec_ops[op->opnum](argp, &op->u);
+		else {
+			op->opnum = OP_ILLEGAL;
+			op->status = nfserr_op_illegal;
+		}
+		op->opdesc = OPDESC(op);
+		/*
+		 * We'll try to cache the result in the DRC if any one
+		 * op in the compound wants to be cached:
+		 */
+		cachethis |= nfsd4_cache_this_op(op);
+
+		if (op->opnum == OP_READ || op->opnum == OP_READ_PLUS) {
+			readcount++;
+			readbytes += nfsd4_max_reply(argp->rqstp, op);
+		} else
+			max_reply += nfsd4_max_reply(argp->rqstp, op);
+		/*
+		 * OP_LOCK and OP_LOCKT may return a conflicting lock.
+		 * (Special case because it will just skip encoding this
+		 * if it runs out of xdr buffer space, and it is the only
+		 * operation that behaves this way.)
+		 */
+		if (op->opnum == OP_LOCK || op->opnum == OP_LOCKT)
+			max_reply += NFS4_OPAQUE_LIMIT;
+
+		if (op->status) {
+			argp->opcnt = i+1;
+			break;
+		}
+	}
+	/* Sessions make the DRC unnecessary: */
+	if (argp->minorversion)
+		cachethis = false;
+	svc_reserve(argp->rqstp, max_reply + readbytes);
+	argp->rqstp->rq_cachetype = cachethis ? RC_REPLBUFF : RC_NOCACHE;
+
+	if (readcount > 1 || max_reply > PAGE_SIZE - auth_slack)
+		clear_bit(RQ_SPLICE_OK, &argp->rqstp->rq_flags);
+
+	DECODE_TAIL;
+}
+
+static __be32 *encode_change(__be32 *p, struct kstat *stat, struct inode *inode,
+			     struct svc_export *exp)
+{
+	if (exp->ex_flags & NFSEXP_V4ROOT) {
+		*p++ = cpu_to_be32(convert_to_wallclock(exp->cd->flush_time));
+		*p++ = 0;
+	} else if (IS_I_VERSION(inode)) {
+		p = xdr_encode_hyper(p, nfsd4_change_attribute(stat, inode));
+	} else {
+		*p++ = cpu_to_be32(stat->ctime.tv_sec);
+		*p++ = cpu_to_be32(stat->ctime.tv_nsec);
+	}
+	return p;
+}
+
+/*
+ * ctime (in NFSv4, time_metadata) is not writeable, and the client
+ * doesn't really care what resolution could theoretically be stored by
+ * the filesystem.
+ *
+ * The client cares how close together changes can be while still
+ * guaranteeing ctime changes.  For most filesystems (which have
+ * timestamps with nanosecond fields) that is limited by the resolution
+ * of the time returned from current_time() (which I'm assuming to be
+ * 1/HZ).
+ */
+static __be32 *encode_time_delta(__be32 *p, struct inode *inode)
+{
+	struct timespec64 ts;
+	u32 ns;
+
+	ns = max_t(u32, NSEC_PER_SEC/HZ, inode->i_sb->s_time_gran);
+	ts = ns_to_timespec64(ns);
+
+	p = xdr_encode_hyper(p, ts.tv_sec);
+	*p++ = cpu_to_be32(ts.tv_nsec);
+
+	return p;
+}
+
+static __be32 *encode_cinfo(__be32 *p, struct nfsd4_change_info *c)
+{
+	*p++ = cpu_to_be32(c->atomic);
+	if (c->change_supported) {
+		p = xdr_encode_hyper(p, c->before_change);
+		p = xdr_encode_hyper(p, c->after_change);
+	} else {
+		*p++ = cpu_to_be32(c->before_ctime_sec);
+		*p++ = cpu_to_be32(c->before_ctime_nsec);
+		*p++ = cpu_to_be32(c->after_ctime_sec);
+		*p++ = cpu_to_be32(c->after_ctime_nsec);
+	}
+	return p;
+}
+
+/* Encode as an array of strings the string given with components
+ * separated @sep, escaped with esc_enter and esc_exit.
+ */
+static __be32 nfsd4_encode_components_esc(struct xdr_stream *xdr, char sep,
+					  char *components, char esc_enter,
+					  char esc_exit)
+{
+	__be32 *p;
+	__be32 pathlen;
+	int pathlen_offset;
+	int strlen, count=0;
+	char *str, *end, *next;
+
+	dprintk("nfsd4_encode_components(%s)\n", components);
+
+	pathlen_offset = xdr->buf->len;
+	p = xdr_reserve_space(xdr, 4);
+	if (!p)
+		return nfserr_resource;
+	p++; /* We will fill this in with @count later */
+
+	end = str = components;
+	while (*end) {
+		bool found_esc = false;
+
+		/* try to parse as esc_start, ..., esc_end, sep */
+		if (*str == esc_enter) {
+			for (; *end && (*end != esc_exit); end++)
+				/* find esc_exit or end of string */;
+			next = end + 1;
+			if (*end && (!*next || *next == sep)) {
+				str++;
+				found_esc = true;
+			}
+		}
+
+		if (!found_esc)
+			for (; *end && (*end != sep); end++)
+				/* find sep or end of string */;
+
+		strlen = end - str;
+		if (strlen) {
+			p = xdr_reserve_space(xdr, strlen + 4);
+			if (!p)
+				return nfserr_resource;
+			p = xdr_encode_opaque(p, str, strlen);
+			count++;
+		}
+		else
+			end++;
+		if (found_esc)
+			end = next;
+
+		str = end;
+	}
+	pathlen = htonl(count);
+	write_bytes_to_xdr_buf(xdr->buf, pathlen_offset, &pathlen, 4);
+	return 0;
+}
+
+/* Encode as an array of strings the string given with components
+ * separated @sep.
+ */
+static __be32 nfsd4_encode_components(struct xdr_stream *xdr, char sep,
+				      char *components)
+{
+	return nfsd4_encode_components_esc(xdr, sep, components, 0, 0);
+}
+
+/*
+ * encode a location element of a fs_locations structure
+ */
+static __be32 nfsd4_encode_fs_location4(struct xdr_stream *xdr,
+					struct nfsd4_fs_location *location)
+{
+	__be32 status;
+
+	status = nfsd4_encode_components_esc(xdr, ':', location->hosts,
+						'[', ']');
+	if (status)
+		return status;
+	status = nfsd4_encode_components(xdr, '/', location->path);
+	if (status)
+		return status;
+	return 0;
+}
+
+/*
+ * Encode a path in RFC3530 'pathname4' format
+ */
+static __be32 nfsd4_encode_path(struct xdr_stream *xdr,
+				const struct path *root,
+				const struct path *path)
+{
+	struct path cur = *path;
+	__be32 *p;
+	struct dentry **components = NULL;
+	unsigned int ncomponents = 0;
+	__be32 err = nfserr_jukebox;
+
+	dprintk("nfsd4_encode_components(");
+
+	path_get(&cur);
+	/* First walk the path up to the nfsd root, and store the
+	 * dentries/path components in an array.
+	 */
+	for (;;) {
+		if (path_equal(&cur, root))
+			break;
+		if (cur.dentry == cur.mnt->mnt_root) {
+			if (follow_up(&cur))
+				continue;
+			goto out_free;
+		}
+		if ((ncomponents & 15) == 0) {
+			struct dentry **new;
+			new = krealloc(components,
+					sizeof(*new) * (ncomponents + 16),
+					GFP_KERNEL);
+			if (!new)
+				goto out_free;
+			components = new;
+		}
+		components[ncomponents++] = cur.dentry;
+		cur.dentry = dget_parent(cur.dentry);
+	}
+	err = nfserr_resource;
+	p = xdr_reserve_space(xdr, 4);
+	if (!p)
+		goto out_free;
+	*p++ = cpu_to_be32(ncomponents);
+
+	while (ncomponents) {
+		struct dentry *dentry = components[ncomponents - 1];
+		unsigned int len;
+
+		spin_lock(&dentry->d_lock);
+		len = dentry->d_name.len;
+		p = xdr_reserve_space(xdr, len + 4);
+		if (!p) {
+			spin_unlock(&dentry->d_lock);
+			goto out_free;
+		}
+		p = xdr_encode_opaque(p, dentry->d_name.name, len);
+		dprintk("/%pd", dentry);
+		spin_unlock(&dentry->d_lock);
+		dput(dentry);
+		ncomponents--;
+	}
+
+	err = 0;
+out_free:
+	dprintk(")\n");
+	while (ncomponents)
+		dput(components[--ncomponents]);
+	kfree(components);
+	path_put(&cur);
+	return err;
+}
+
+static __be32 nfsd4_encode_fsloc_fsroot(struct xdr_stream *xdr,
+			struct svc_rqst *rqstp, const struct path *path)
+{
+	struct svc_export *exp_ps;
+	__be32 res;
+
+	exp_ps = rqst_find_fsidzero_export(rqstp);
+	if (IS_ERR(exp_ps))
+		return nfserrno(PTR_ERR(exp_ps));
+	res = nfsd4_encode_path(xdr, &exp_ps->ex_path, path);
+	exp_put(exp_ps);
+	return res;
+}
+
+/*
+ *  encode a fs_locations structure
+ */
+static __be32 nfsd4_encode_fs_locations(struct xdr_stream *xdr,
+			struct svc_rqst *rqstp, struct svc_export *exp)
+{
+	__be32 status;
+	int i;
+	__be32 *p;
+	struct nfsd4_fs_locations *fslocs = &exp->ex_fslocs;
+
+	status = nfsd4_encode_fsloc_fsroot(xdr, rqstp, &exp->ex_path);
+	if (status)
+		return status;
+	p = xdr_reserve_space(xdr, 4);
+	if (!p)
+		return nfserr_resource;
+	*p++ = cpu_to_be32(fslocs->locations_count);
+	for (i=0; i<fslocs->locations_count; i++) {
+		status = nfsd4_encode_fs_location4(xdr, &fslocs->locations[i]);
+		if (status)
+			return status;
+	}
+	return 0;
+}
+
+static u32 nfs4_file_type(umode_t mode)
+{
+	switch (mode & S_IFMT) {
+	case S_IFIFO:	return NF4FIFO;
+	case S_IFCHR:	return NF4CHR;
+	case S_IFDIR:	return NF4DIR;
+	case S_IFBLK:	return NF4BLK;
+	case S_IFLNK:	return NF4LNK;
+	case S_IFREG:	return NF4REG;
+	case S_IFSOCK:	return NF4SOCK;
+	default:	return NF4BAD;
+	};
+}
+
+static inline __be32
+nfsd4_encode_aclname(struct xdr_stream *xdr, struct svc_rqst *rqstp,
+		     struct nfs4_ace *ace)
+{
+	if (ace->whotype != NFS4_ACL_WHO_NAMED)
+		return nfs4_acl_write_who(xdr, ace->whotype);
+	else if (ace->flag & NFS4_ACE_IDENTIFIER_GROUP)
+		return nfsd4_encode_group(xdr, rqstp, ace->who_gid);
+	else
+		return nfsd4_encode_user(xdr, rqstp, ace->who_uid);
+}
+
+static inline __be32
+nfsd4_encode_layout_types(struct xdr_stream *xdr, u32 layout_types)
+{
+	__be32		*p;
+	unsigned long	i = hweight_long(layout_types);
+
+	p = xdr_reserve_space(xdr, 4 + 4 * i);
+	if (!p)
+		return nfserr_resource;
+
+	*p++ = cpu_to_be32(i);
+
+	for (i = LAYOUT_NFSV4_1_FILES; i < LAYOUT_TYPE_MAX; ++i)
+		if (layout_types & (1 << i))
+			*p++ = cpu_to_be32(i);
+
+	return 0;
+}
+
+#define WORD0_ABSENT_FS_ATTRS (FATTR4_WORD0_FS_LOCATIONS | FATTR4_WORD0_FSID | \
+			      FATTR4_WORD0_RDATTR_ERROR)
+#define WORD1_ABSENT_FS_ATTRS FATTR4_WORD1_MOUNTED_ON_FILEID
+#define WORD2_ABSENT_FS_ATTRS 0
+
+#ifdef CONFIG_NFSD_V4_SECURITY_LABEL
+static inline __be32
+nfsd4_encode_security_label(struct xdr_stream *xdr, struct svc_rqst *rqstp,
+			    void *context, int len)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, len + 4 + 4 + 4);
+	if (!p)
+		return nfserr_resource;
+
+	/*
+	 * For now we use a 0 here to indicate the null translation; in
+	 * the future we may place a call to translation code here.
+	 */
+	*p++ = cpu_to_be32(0); /* lfs */
+	*p++ = cpu_to_be32(0); /* pi */
+	p = xdr_encode_opaque(p, context, len);
+	return 0;
+}
+#else
+static inline __be32
+nfsd4_encode_security_label(struct xdr_stream *xdr, struct svc_rqst *rqstp,
+			    void *context, int len)
+{ return 0; }
+#endif
+
+static __be32 fattr_handle_absent_fs(u32 *bmval0, u32 *bmval1, u32 *bmval2, u32 *rdattr_err)
+{
+	/* As per referral draft:  */
+	if (*bmval0 & ~WORD0_ABSENT_FS_ATTRS ||
+	    *bmval1 & ~WORD1_ABSENT_FS_ATTRS) {
+		if (*bmval0 & FATTR4_WORD0_RDATTR_ERROR ||
+	            *bmval0 & FATTR4_WORD0_FS_LOCATIONS)
+			*rdattr_err = NFSERR_MOVED;
+		else
+			return nfserr_moved;
+	}
+	*bmval0 &= WORD0_ABSENT_FS_ATTRS;
+	*bmval1 &= WORD1_ABSENT_FS_ATTRS;
+	*bmval2 &= WORD2_ABSENT_FS_ATTRS;
+	return 0;
+}
+
+
+static int get_parent_attributes(struct svc_export *exp, struct kstat *stat)
+{
+	struct path path = exp->ex_path;
+	int err;
+
+	path_get(&path);
+	while (follow_up(&path)) {
+		if (path.dentry != path.mnt->mnt_root)
+			break;
+	}
+	err = vfs_getattr(&path, stat, STATX_BASIC_STATS, AT_STATX_SYNC_AS_STAT);
+	path_put(&path);
+	return err;
+}
+
+static __be32
+nfsd4_encode_bitmap(struct xdr_stream *xdr, u32 bmval0, u32 bmval1, u32 bmval2)
+{
+	__be32 *p;
+
+	if (bmval2) {
+		p = xdr_reserve_space(xdr, 16);
+		if (!p)
+			goto out_resource;
+		*p++ = cpu_to_be32(3);
+		*p++ = cpu_to_be32(bmval0);
+		*p++ = cpu_to_be32(bmval1);
+		*p++ = cpu_to_be32(bmval2);
+	} else if (bmval1) {
+		p = xdr_reserve_space(xdr, 12);
+		if (!p)
+			goto out_resource;
+		*p++ = cpu_to_be32(2);
+		*p++ = cpu_to_be32(bmval0);
+		*p++ = cpu_to_be32(bmval1);
+	} else {
+		p = xdr_reserve_space(xdr, 8);
+		if (!p)
+			goto out_resource;
+		*p++ = cpu_to_be32(1);
+		*p++ = cpu_to_be32(bmval0);
+	}
+
+	return 0;
+out_resource:
+	return nfserr_resource;
+}
+
+/*
+ * Note: @fhp can be NULL; in this case, we might have to compose the filehandle
+ * ourselves.
+ */
+static __be32
+nfsd4_encode_fattr(struct xdr_stream *xdr, struct svc_fh *fhp,
+		struct svc_export *exp,
+		struct dentry *dentry, u32 *bmval,
+		struct svc_rqst *rqstp, int ignore_crossmnt)
+{
+	u32 bmval0 = bmval[0];
+	u32 bmval1 = bmval[1];
+	u32 bmval2 = bmval[2];
+	struct kstat stat;
+	struct svc_fh *tempfh = NULL;
+	struct kstatfs statfs;
+	__be32 *p;
+	int starting_len = xdr->buf->len;
+	int attrlen_offset;
+	__be32 attrlen;
+	u32 dummy;
+	u64 dummy64;
+	u32 rdattr_err = 0;
+	__be32 status;
+	int err;
+	struct nfs4_acl *acl = NULL;
+#ifdef CONFIG_NFSD_V4_SECURITY_LABEL
+	void *context = NULL;
+	int contextlen;
+#endif
+	bool contextsupport = false;
+	struct nfsd4_compoundres *resp = rqstp->rq_resp;
+	u32 minorversion = resp->cstate.minorversion;
+	struct path path = {
+		.mnt	= exp->ex_path.mnt,
+		.dentry	= dentry,
+	};
+	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+
+	BUG_ON(bmval1 & NFSD_WRITEONLY_ATTRS_WORD1);
+	BUG_ON(!nfsd_attrs_supported(minorversion, bmval));
+
+	if (exp->ex_fslocs.migrated) {
+		status = fattr_handle_absent_fs(&bmval0, &bmval1, &bmval2, &rdattr_err);
+		if (status)
+			goto out;
+	}
+
+	err = vfs_getattr(&path, &stat, STATX_BASIC_STATS, AT_STATX_SYNC_AS_STAT);
+	if (err)
+		goto out_nfserr;
+	if ((bmval0 & (FATTR4_WORD0_FILES_AVAIL | FATTR4_WORD0_FILES_FREE |
+			FATTR4_WORD0_FILES_TOTAL | FATTR4_WORD0_MAXNAME)) ||
+	    (bmval1 & (FATTR4_WORD1_SPACE_AVAIL | FATTR4_WORD1_SPACE_FREE |
+		       FATTR4_WORD1_SPACE_TOTAL))) {
+		err = vfs_statfs(&path, &statfs);
+		if (err)
+			goto out_nfserr;
+	}
+	if ((bmval0 & (FATTR4_WORD0_FILEHANDLE | FATTR4_WORD0_FSID)) && !fhp) {
+		tempfh = kmalloc(sizeof(struct svc_fh), GFP_KERNEL);
+		status = nfserr_jukebox;
+		if (!tempfh)
+			goto out;
+		fh_init(tempfh, NFS4_FHSIZE);
+		status = fh_compose(tempfh, exp, dentry, NULL);
+		if (status)
+			goto out;
+		fhp = tempfh;
+	}
+	if (bmval0 & FATTR4_WORD0_ACL) {
+		err = nfsd4_get_nfs4_acl(rqstp, dentry, &acl);
+		if (err == -EOPNOTSUPP)
+			bmval0 &= ~FATTR4_WORD0_ACL;
+		else if (err == -EINVAL) {
+			status = nfserr_attrnotsupp;
+			goto out;
+		} else if (err != 0)
+			goto out_nfserr;
+	}
+
+#ifdef CONFIG_NFSD_V4_SECURITY_LABEL
+	if ((bmval2 & FATTR4_WORD2_SECURITY_LABEL) ||
+	     bmval0 & FATTR4_WORD0_SUPPORTED_ATTRS) {
+		if (exp->ex_flags & NFSEXP_SECURITY_LABEL)
+			err = security_inode_getsecctx(d_inode(dentry),
+						&context, &contextlen);
+		else
+			err = -EOPNOTSUPP;
+		contextsupport = (err == 0);
+		if (bmval2 & FATTR4_WORD2_SECURITY_LABEL) {
+			if (err == -EOPNOTSUPP)
+				bmval2 &= ~FATTR4_WORD2_SECURITY_LABEL;
+			else if (err)
+				goto out_nfserr;
+		}
+	}
+#endif /* CONFIG_NFSD_V4_SECURITY_LABEL */
+
+	status = nfsd4_encode_bitmap(xdr, bmval0, bmval1, bmval2);
+	if (status)
+		goto out;
+
+	attrlen_offset = xdr->buf->len;
+	p = xdr_reserve_space(xdr, 4);
+	if (!p)
+		goto out_resource;
+	p++;                /* to be backfilled later */
+
+	if (bmval0 & FATTR4_WORD0_SUPPORTED_ATTRS) {
+		u32 supp[3];
+
+		memcpy(supp, nfsd_suppattrs[minorversion], sizeof(supp));
+
+		if (!IS_POSIXACL(dentry->d_inode))
+			supp[0] &= ~FATTR4_WORD0_ACL;
+		if (!contextsupport)
+			supp[2] &= ~FATTR4_WORD2_SECURITY_LABEL;
+		if (!supp[2]) {
+			p = xdr_reserve_space(xdr, 12);
+			if (!p)
+				goto out_resource;
+			*p++ = cpu_to_be32(2);
+			*p++ = cpu_to_be32(supp[0]);
+			*p++ = cpu_to_be32(supp[1]);
+		} else {
+			p = xdr_reserve_space(xdr, 16);
+			if (!p)
+				goto out_resource;
+			*p++ = cpu_to_be32(3);
+			*p++ = cpu_to_be32(supp[0]);
+			*p++ = cpu_to_be32(supp[1]);
+			*p++ = cpu_to_be32(supp[2]);
+		}
+	}
+	if (bmval0 & FATTR4_WORD0_TYPE) {
+		p = xdr_reserve_space(xdr, 4);
+		if (!p)
+			goto out_resource;
+		dummy = nfs4_file_type(stat.mode);
+		if (dummy == NF4BAD) {
+			status = nfserr_serverfault;
+			goto out;
+		}
+		*p++ = cpu_to_be32(dummy);
+	}
+	if (bmval0 & FATTR4_WORD0_FH_EXPIRE_TYPE) {
+		p = xdr_reserve_space(xdr, 4);
+		if (!p)
+			goto out_resource;
+		if (exp->ex_flags & NFSEXP_NOSUBTREECHECK)
+			*p++ = cpu_to_be32(NFS4_FH_PERSISTENT);
+		else
+			*p++ = cpu_to_be32(NFS4_FH_PERSISTENT|
+						NFS4_FH_VOL_RENAME);
+	}
+	if (bmval0 & FATTR4_WORD0_CHANGE) {
+		p = xdr_reserve_space(xdr, 8);
+		if (!p)
+			goto out_resource;
+		p = encode_change(p, &stat, d_inode(dentry), exp);
+	}
+	if (bmval0 & FATTR4_WORD0_SIZE) {
+		p = xdr_reserve_space(xdr, 8);
+		if (!p)
+			goto out_resource;
+		p = xdr_encode_hyper(p, stat.size);
+	}
+	if (bmval0 & FATTR4_WORD0_LINK_SUPPORT) {
+		p = xdr_reserve_space(xdr, 4);
+		if (!p)
+			goto out_resource;
+		*p++ = cpu_to_be32(1);
+	}
+	if (bmval0 & FATTR4_WORD0_SYMLINK_SUPPORT) {
+		p = xdr_reserve_space(xdr, 4);
+		if (!p)
+			goto out_resource;
+		*p++ = cpu_to_be32(1);
+	}
+	if (bmval0 & FATTR4_WORD0_NAMED_ATTR) {
+		p = xdr_reserve_space(xdr, 4);
+		if (!p)
+			goto out_resource;
+		*p++ = cpu_to_be32(0);
+	}
+	if (bmval0 & FATTR4_WORD0_FSID) {
+		p = xdr_reserve_space(xdr, 16);
+		if (!p)
+			goto out_resource;
+		if (exp->ex_fslocs.migrated) {
+			p = xdr_encode_hyper(p, NFS4_REFERRAL_FSID_MAJOR);
+			p = xdr_encode_hyper(p, NFS4_REFERRAL_FSID_MINOR);
+		} else switch(fsid_source(fhp)) {
+		case FSIDSOURCE_FSID:
+			p = xdr_encode_hyper(p, (u64)exp->ex_fsid);
+			p = xdr_encode_hyper(p, (u64)0);
+			break;
+		case FSIDSOURCE_DEV:
+			*p++ = cpu_to_be32(0);
+			*p++ = cpu_to_be32(MAJOR(stat.dev));
+			*p++ = cpu_to_be32(0);
+			*p++ = cpu_to_be32(MINOR(stat.dev));
+			break;
+		case FSIDSOURCE_UUID:
+			p = xdr_encode_opaque_fixed(p, exp->ex_uuid,
+								EX_UUID_LEN);
+			break;
+		}
+	}
+	if (bmval0 & FATTR4_WORD0_UNIQUE_HANDLES) {
+		p = xdr_reserve_space(xdr, 4);
+		if (!p)
+			goto out_resource;
+		*p++ = cpu_to_be32(0);
+	}
+	if (bmval0 & FATTR4_WORD0_LEASE_TIME) {
+		p = xdr_reserve_space(xdr, 4);
+		if (!p)
+			goto out_resource;
+		*p++ = cpu_to_be32(nn->nfsd4_lease);
+	}
+	if (bmval0 & FATTR4_WORD0_RDATTR_ERROR) {
+		p = xdr_reserve_space(xdr, 4);
+		if (!p)
+			goto out_resource;
+		*p++ = cpu_to_be32(rdattr_err);
+	}
+	if (bmval0 & FATTR4_WORD0_ACL) {
+		struct nfs4_ace *ace;
+
+		if (acl == NULL) {
+			p = xdr_reserve_space(xdr, 4);
+			if (!p)
+				goto out_resource;
+
+			*p++ = cpu_to_be32(0);
+			goto out_acl;
+		}
+		p = xdr_reserve_space(xdr, 4);
+		if (!p)
+			goto out_resource;
+		*p++ = cpu_to_be32(acl->naces);
+
+		for (ace = acl->aces; ace < acl->aces + acl->naces; ace++) {
+			p = xdr_reserve_space(xdr, 4*3);
+			if (!p)
+				goto out_resource;
+			*p++ = cpu_to_be32(ace->type);
+			*p++ = cpu_to_be32(ace->flag);
+			*p++ = cpu_to_be32(ace->access_mask &
+							NFS4_ACE_MASK_ALL);
+			status = nfsd4_encode_aclname(xdr, rqstp, ace);
+			if (status)
+				goto out;
+		}
+	}
+out_acl:
+	if (bmval0 & FATTR4_WORD0_ACLSUPPORT) {
+		p = xdr_reserve_space(xdr, 4);
+		if (!p)
+			goto out_resource;
+		*p++ = cpu_to_be32(IS_POSIXACL(dentry->d_inode) ?
+			ACL4_SUPPORT_ALLOW_ACL|ACL4_SUPPORT_DENY_ACL : 0);
+	}
+	if (bmval0 & FATTR4_WORD0_CANSETTIME) {
+		p = xdr_reserve_space(xdr, 4);
+		if (!p)
+			goto out_resource;
+		*p++ = cpu_to_be32(1);
+	}
+	if (bmval0 & FATTR4_WORD0_CASE_INSENSITIVE) {
+		p = xdr_reserve_space(xdr, 4);
+		if (!p)
+			goto out_resource;
+		*p++ = cpu_to_be32(0);
+	}
+	if (bmval0 & FATTR4_WORD0_CASE_PRESERVING) {
+		p = xdr_reserve_space(xdr, 4);
+		if (!p)
+			goto out_resource;
+		*p++ = cpu_to_be32(1);
+	}
+	if (bmval0 & FATTR4_WORD0_CHOWN_RESTRICTED) {
+		p = xdr_reserve_space(xdr, 4);
+		if (!p)
+			goto out_resource;
+		*p++ = cpu_to_be32(1);
+	}
+	if (bmval0 & FATTR4_WORD0_FILEHANDLE) {
+		p = xdr_reserve_space(xdr, fhp->fh_handle.fh_size + 4);
+		if (!p)
+			goto out_resource;
+		p = xdr_encode_opaque(p, &fhp->fh_handle.fh_base,
+					fhp->fh_handle.fh_size);
+	}
+	if (bmval0 & FATTR4_WORD0_FILEID) {
+		p = xdr_reserve_space(xdr, 8);
+		if (!p)
+			goto out_resource;
+		p = xdr_encode_hyper(p, stat.ino);
+	}
+	if (bmval0 & FATTR4_WORD0_FILES_AVAIL) {
+		p = xdr_reserve_space(xdr, 8);
+		if (!p)
+			goto out_resource;
+		p = xdr_encode_hyper(p, (u64) statfs.f_ffree);
+	}
+	if (bmval0 & FATTR4_WORD0_FILES_FREE) {
+		p = xdr_reserve_space(xdr, 8);
+		if (!p)
+			goto out_resource;
+		p = xdr_encode_hyper(p, (u64) statfs.f_ffree);
+	}
+	if (bmval0 & FATTR4_WORD0_FILES_TOTAL) {
+		p = xdr_reserve_space(xdr, 8);
+		if (!p)
+			goto out_resource;
+		p = xdr_encode_hyper(p, (u64) statfs.f_files);
+	}
+	if (bmval0 & FATTR4_WORD0_FS_LOCATIONS) {
+		status = nfsd4_encode_fs_locations(xdr, rqstp, exp);
+		if (status)
+			goto out;
+	}
+	if (bmval0 & FATTR4_WORD0_HOMOGENEOUS) {
+		p = xdr_reserve_space(xdr, 4);
+		if (!p)
+			goto out_resource;
+		*p++ = cpu_to_be32(1);
+	}
+	if (bmval0 & FATTR4_WORD0_MAXFILESIZE) {
+		p = xdr_reserve_space(xdr, 8);
+		if (!p)
+			goto out_resource;
+		p = xdr_encode_hyper(p, exp->ex_path.mnt->mnt_sb->s_maxbytes);
+	}
+	if (bmval0 & FATTR4_WORD0_MAXLINK) {
+		p = xdr_reserve_space(xdr, 4);
+		if (!p)
+			goto out_resource;
+		*p++ = cpu_to_be32(255);
+	}
+	if (bmval0 & FATTR4_WORD0_MAXNAME) {
+		p = xdr_reserve_space(xdr, 4);
+		if (!p)
+			goto out_resource;
+		*p++ = cpu_to_be32(statfs.f_namelen);
+	}
+	if (bmval0 & FATTR4_WORD0_MAXREAD) {
+		p = xdr_reserve_space(xdr, 8);
+		if (!p)
+			goto out_resource;
+		p = xdr_encode_hyper(p, (u64) svc_max_payload(rqstp));
+	}
+	if (bmval0 & FATTR4_WORD0_MAXWRITE) {
+		p = xdr_reserve_space(xdr, 8);
+		if (!p)
+			goto out_resource;
+		p = xdr_encode_hyper(p, (u64) svc_max_payload(rqstp));
+	}
+	if (bmval1 & FATTR4_WORD1_MODE) {
+		p = xdr_reserve_space(xdr, 4);
+		if (!p)
+			goto out_resource;
+		*p++ = cpu_to_be32(stat.mode & S_IALLUGO);
+	}
+	if (bmval1 & FATTR4_WORD1_NO_TRUNC) {
+		p = xdr_reserve_space(xdr, 4);
+		if (!p)
+			goto out_resource;
+		*p++ = cpu_to_be32(1);
+	}
+	if (bmval1 & FATTR4_WORD1_NUMLINKS) {
+		p = xdr_reserve_space(xdr, 4);
+		if (!p)
+			goto out_resource;
+		*p++ = cpu_to_be32(stat.nlink);
+	}
+	if (bmval1 & FATTR4_WORD1_OWNER) {
+		status = nfsd4_encode_user(xdr, rqstp, stat.uid);
+		if (status)
+			goto out;
+	}
+	if (bmval1 & FATTR4_WORD1_OWNER_GROUP) {
+		status = nfsd4_encode_group(xdr, rqstp, stat.gid);
+		if (status)
+			goto out;
+	}
+	if (bmval1 & FATTR4_WORD1_RAWDEV) {
+		p = xdr_reserve_space(xdr, 8);
+		if (!p)
+			goto out_resource;
+		*p++ = cpu_to_be32((u32) MAJOR(stat.rdev));
+		*p++ = cpu_to_be32((u32) MINOR(stat.rdev));
+	}
+	if (bmval1 & FATTR4_WORD1_SPACE_AVAIL) {
+		p = xdr_reserve_space(xdr, 8);
+		if (!p)
+			goto out_resource;
+		dummy64 = (u64)statfs.f_bavail * (u64)statfs.f_bsize;
+		p = xdr_encode_hyper(p, dummy64);
+	}
+	if (bmval1 & FATTR4_WORD1_SPACE_FREE) {
+		p = xdr_reserve_space(xdr, 8);
+		if (!p)
+			goto out_resource;
+		dummy64 = (u64)statfs.f_bfree * (u64)statfs.f_bsize;
+		p = xdr_encode_hyper(p, dummy64);
+	}
+	if (bmval1 & FATTR4_WORD1_SPACE_TOTAL) {
+		p = xdr_reserve_space(xdr, 8);
+		if (!p)
+			goto out_resource;
+		dummy64 = (u64)statfs.f_blocks * (u64)statfs.f_bsize;
+		p = xdr_encode_hyper(p, dummy64);
+	}
+	if (bmval1 & FATTR4_WORD1_SPACE_USED) {
+		p = xdr_reserve_space(xdr, 8);
+		if (!p)
+			goto out_resource;
+		dummy64 = (u64)stat.blocks << 9;
+		p = xdr_encode_hyper(p, dummy64);
+	}
+	if (bmval1 & FATTR4_WORD1_TIME_ACCESS) {
+		p = xdr_reserve_space(xdr, 12);
+		if (!p)
+			goto out_resource;
+		p = xdr_encode_hyper(p, (s64)stat.atime.tv_sec);
+		*p++ = cpu_to_be32(stat.atime.tv_nsec);
+	}
+	if (bmval1 & FATTR4_WORD1_TIME_DELTA) {
+		p = xdr_reserve_space(xdr, 12);
+		if (!p)
+			goto out_resource;
+		p = encode_time_delta(p, d_inode(dentry));
+	}
+	if (bmval1 & FATTR4_WORD1_TIME_METADATA) {
+		p = xdr_reserve_space(xdr, 12);
+		if (!p)
+			goto out_resource;
+		p = xdr_encode_hyper(p, (s64)stat.ctime.tv_sec);
+		*p++ = cpu_to_be32(stat.ctime.tv_nsec);
+	}
+	if (bmval1 & FATTR4_WORD1_TIME_MODIFY) {
+		p = xdr_reserve_space(xdr, 12);
+		if (!p)
+			goto out_resource;
+		p = xdr_encode_hyper(p, (s64)stat.mtime.tv_sec);
+		*p++ = cpu_to_be32(stat.mtime.tv_nsec);
+	}
+	if (bmval1 & FATTR4_WORD1_MOUNTED_ON_FILEID) {
+		struct kstat parent_stat;
+		u64 ino = stat.ino;
+
+		p = xdr_reserve_space(xdr, 8);
+		if (!p)
+                	goto out_resource;
+		/*
+		 * Get parent's attributes if not ignoring crossmount
+		 * and this is the root of a cross-mounted filesystem.
+		 */
+		if (ignore_crossmnt == 0 &&
+		    dentry == exp->ex_path.mnt->mnt_root) {
+			err = get_parent_attributes(exp, &parent_stat);
+			if (err)
+				goto out_nfserr;
+			ino = parent_stat.ino;
+		}
+		p = xdr_encode_hyper(p, ino);
+	}
+#ifdef CONFIG_NFSD_PNFS
+	if (bmval1 & FATTR4_WORD1_FS_LAYOUT_TYPES) {
+		status = nfsd4_encode_layout_types(xdr, exp->ex_layout_types);
+		if (status)
+			goto out;
+	}
+
+	if (bmval2 & FATTR4_WORD2_LAYOUT_TYPES) {
+		status = nfsd4_encode_layout_types(xdr, exp->ex_layout_types);
+		if (status)
+			goto out;
+	}
+
+	if (bmval2 & FATTR4_WORD2_LAYOUT_BLKSIZE) {
+		p = xdr_reserve_space(xdr, 4);
+		if (!p)
+			goto out_resource;
+		*p++ = cpu_to_be32(stat.blksize);
+	}
+#endif /* CONFIG_NFSD_PNFS */
+	if (bmval2 & FATTR4_WORD2_SUPPATTR_EXCLCREAT) {
+		u32 supp[3];
+
+		memcpy(supp, nfsd_suppattrs[minorversion], sizeof(supp));
+		supp[0] &= NFSD_SUPPATTR_EXCLCREAT_WORD0;
+		supp[1] &= NFSD_SUPPATTR_EXCLCREAT_WORD1;
+		supp[2] &= NFSD_SUPPATTR_EXCLCREAT_WORD2;
+
+		status = nfsd4_encode_bitmap(xdr, supp[0], supp[1], supp[2]);
+		if (status)
+			goto out;
+	}
+
+	if (bmval2 & FATTR4_WORD2_CHANGE_ATTR_TYPE) {
+		p = xdr_reserve_space(xdr, 4);
+		if (!p)
+			goto out_resource;
+		if (IS_I_VERSION(d_inode(dentry)))
+			*p++ = cpu_to_be32(NFS4_CHANGE_TYPE_IS_MONOTONIC_INCR);
+		else
+			*p++ = cpu_to_be32(NFS4_CHANGE_TYPE_IS_TIME_METADATA);
+	}
+
+#ifdef CONFIG_NFSD_V4_SECURITY_LABEL
+	if (bmval2 & FATTR4_WORD2_SECURITY_LABEL) {
+		status = nfsd4_encode_security_label(xdr, rqstp, context,
+								contextlen);
+		if (status)
+			goto out;
+	}
+#endif
+
+	if (bmval2 & FATTR4_WORD2_XATTR_SUPPORT) {
+		p = xdr_reserve_space(xdr, 4);
+		if (!p)
+			goto out_resource;
+		err = xattr_supported_namespace(d_inode(dentry),
+						XATTR_USER_PREFIX);
+		*p++ = cpu_to_be32(err == 0);
+	}
+
+	attrlen = htonl(xdr->buf->len - attrlen_offset - 4);
+	write_bytes_to_xdr_buf(xdr->buf, attrlen_offset, &attrlen, 4);
+	status = nfs_ok;
+
+out:
+#ifdef CONFIG_NFSD_V4_SECURITY_LABEL
+	if (context)
+		security_release_secctx(context, contextlen);
+#endif /* CONFIG_NFSD_V4_SECURITY_LABEL */
+	kfree(acl);
+	if (tempfh) {
+		fh_put(tempfh);
+		kfree(tempfh);
+	}
+	if (status)
+		xdr_truncate_encode(xdr, starting_len);
+	return status;
+out_nfserr:
+	status = nfserrno(err);
+	goto out;
+out_resource:
+	status = nfserr_resource;
+	goto out;
+}
+
+static void svcxdr_init_encode_from_buffer(struct xdr_stream *xdr,
+				struct xdr_buf *buf, __be32 *p, int bytes)
+{
+	xdr->scratch.iov_len = 0;
+	memset(buf, 0, sizeof(struct xdr_buf));
+	buf->head[0].iov_base = p;
+	buf->head[0].iov_len = 0;
+	buf->len = 0;
+	xdr->buf = buf;
+	xdr->iov = buf->head;
+	xdr->p = p;
+	xdr->end = (void *)p + bytes;
+	buf->buflen = bytes;
+}
+
+__be32 nfsd4_encode_fattr_to_buf(__be32 **p, int words,
+			struct svc_fh *fhp, struct svc_export *exp,
+			struct dentry *dentry, u32 *bmval,
+			struct svc_rqst *rqstp, int ignore_crossmnt)
+{
+	struct xdr_buf dummy;
+	struct xdr_stream xdr;
+	__be32 ret;
+
+	svcxdr_init_encode_from_buffer(&xdr, &dummy, *p, words << 2);
+	ret = nfsd4_encode_fattr(&xdr, fhp, exp, dentry, bmval, rqstp,
+							ignore_crossmnt);
+	*p = xdr.p;
+	return ret;
+}
+
+static inline int attributes_need_mount(u32 *bmval)
+{
+	if (bmval[0] & ~(FATTR4_WORD0_RDATTR_ERROR | FATTR4_WORD0_LEASE_TIME))
+		return 1;
+	if (bmval[1] & ~FATTR4_WORD1_MOUNTED_ON_FILEID)
+		return 1;
+	return 0;
+}
+
+static __be32
+nfsd4_encode_dirent_fattr(struct xdr_stream *xdr, struct nfsd4_readdir *cd,
+			const char *name, int namlen)
+{
+	struct svc_export *exp = cd->rd_fhp->fh_export;
+	struct dentry *dentry;
+	__be32 nfserr;
+	int ignore_crossmnt = 0;
+
+	dentry = lookup_positive_unlocked(name, cd->rd_fhp->fh_dentry, namlen);
+	if (IS_ERR(dentry))
+		return nfserrno(PTR_ERR(dentry));
+
+	exp_get(exp);
+	/*
+	 * In the case of a mountpoint, the client may be asking for
+	 * attributes that are only properties of the underlying filesystem
+	 * as opposed to the cross-mounted file system. In such a case,
+	 * we will not follow the cross mount and will fill the attribtutes
+	 * directly from the mountpoint dentry.
+	 */
+	if (nfsd_mountpoint(dentry, exp)) {
+		int err;
+
+		if (!(exp->ex_flags & NFSEXP_V4ROOT)
+				&& !attributes_need_mount(cd->rd_bmval)) {
+			ignore_crossmnt = 1;
+			goto out_encode;
+		}
+		/*
+		 * Why the heck aren't we just using nfsd_lookup??
+		 * Different "."/".." handling?  Something else?
+		 * At least, add a comment here to explain....
+		 */
+		err = nfsd_cross_mnt(cd->rd_rqstp, &dentry, &exp);
+		if (err) {
+			nfserr = nfserrno(err);
+			goto out_put;
+		}
+		nfserr = check_nfsd_access(exp, cd->rd_rqstp);
+		if (nfserr)
+			goto out_put;
+
+	}
+out_encode:
+	nfserr = nfsd4_encode_fattr(xdr, NULL, exp, dentry, cd->rd_bmval,
+					cd->rd_rqstp, ignore_crossmnt);
+out_put:
+	dput(dentry);
+	exp_put(exp);
+	return nfserr;
+}
+
+static __be32 *
+nfsd4_encode_rdattr_error(struct xdr_stream *xdr, __be32 nfserr)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 20);
+	if (!p)
+		return NULL;
+	*p++ = htonl(2);
+	*p++ = htonl(FATTR4_WORD0_RDATTR_ERROR); /* bmval0 */
+	*p++ = htonl(0);			 /* bmval1 */
+
+	*p++ = htonl(4);     /* attribute length */
+	*p++ = nfserr;       /* no htonl */
+	return p;
+}
+
+static int
+nfsd4_encode_dirent(void *ccdv, const char *name, int namlen,
+		    loff_t offset, u64 ino, unsigned int d_type)
+{
+	struct readdir_cd *ccd = ccdv;
+	struct nfsd4_readdir *cd = container_of(ccd, struct nfsd4_readdir, common);
+	struct xdr_stream *xdr = cd->xdr;
+	int start_offset = xdr->buf->len;
+	int cookie_offset;
+	u32 name_and_cookie;
+	int entry_bytes;
+	__be32 nfserr = nfserr_toosmall;
+	__be64 wire_offset;
+	__be32 *p;
+
+	/* In nfsv4, "." and ".." never make it onto the wire.. */
+	if (name && isdotent(name, namlen)) {
+		cd->common.err = nfs_ok;
+		return 0;
+	}
+
+	if (cd->cookie_offset) {
+		wire_offset = cpu_to_be64(offset);
+		write_bytes_to_xdr_buf(xdr->buf, cd->cookie_offset,
+							&wire_offset, 8);
+	}
+
+	p = xdr_reserve_space(xdr, 4);
+	if (!p)
+		goto fail;
+	*p++ = xdr_one;                             /* mark entry present */
+	cookie_offset = xdr->buf->len;
+	p = xdr_reserve_space(xdr, 3*4 + namlen);
+	if (!p)
+		goto fail;
+	p = xdr_encode_hyper(p, NFS_OFFSET_MAX);    /* offset of next entry */
+	p = xdr_encode_array(p, name, namlen);      /* name length & name */
+
+	nfserr = nfsd4_encode_dirent_fattr(xdr, cd, name, namlen);
+	switch (nfserr) {
+	case nfs_ok:
+		break;
+	case nfserr_resource:
+		nfserr = nfserr_toosmall;
+		goto fail;
+	case nfserr_noent:
+		xdr_truncate_encode(xdr, start_offset);
+		goto skip_entry;
+	case nfserr_jukebox:
+		/*
+		 * The pseudoroot should only display dentries that lead to
+		 * exports. If we get EJUKEBOX here, then we can't tell whether
+		 * this entry should be included. Just fail the whole READDIR
+		 * with NFS4ERR_DELAY in that case, and hope that the situation
+		 * will resolve itself by the client's next attempt.
+		 */
+		if (cd->rd_fhp->fh_export->ex_flags & NFSEXP_V4ROOT)
+			goto fail;
+		fallthrough;
+	default:
+		/*
+		 * If the client requested the RDATTR_ERROR attribute,
+		 * we stuff the error code into this attribute
+		 * and continue.  If this attribute was not requested,
+		 * then in accordance with the spec, we fail the
+		 * entire READDIR operation(!)
+		 */
+		if (!(cd->rd_bmval[0] & FATTR4_WORD0_RDATTR_ERROR))
+			goto fail;
+		p = nfsd4_encode_rdattr_error(xdr, nfserr);
+		if (p == NULL) {
+			nfserr = nfserr_toosmall;
+			goto fail;
+		}
+	}
+	nfserr = nfserr_toosmall;
+	entry_bytes = xdr->buf->len - start_offset;
+	if (entry_bytes > cd->rd_maxcount)
+		goto fail;
+	cd->rd_maxcount -= entry_bytes;
+	/*
+	 * RFC 3530 14.2.24 describes rd_dircount as only a "hint", and
+	 * notes that it could be zero. If it is zero, then the server
+	 * should enforce only the rd_maxcount value.
+	 */
+	if (cd->rd_dircount) {
+		name_and_cookie = 4 + 4 * XDR_QUADLEN(namlen) + 8;
+		if (name_and_cookie > cd->rd_dircount && cd->cookie_offset)
+			goto fail;
+		cd->rd_dircount -= min(cd->rd_dircount, name_and_cookie);
+		if (!cd->rd_dircount)
+			cd->rd_maxcount = 0;
+	}
+
+	cd->cookie_offset = cookie_offset;
+skip_entry:
+	cd->common.err = nfs_ok;
+	return 0;
+fail:
+	xdr_truncate_encode(xdr, start_offset);
+	cd->common.err = nfserr;
+	return -EINVAL;
+}
+
+static __be32
+nfsd4_encode_stateid(struct xdr_stream *xdr, stateid_t *sid)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, sizeof(stateid_t));
+	if (!p)
+		return nfserr_resource;
+	*p++ = cpu_to_be32(sid->si_generation);
+	p = xdr_encode_opaque_fixed(p, &sid->si_opaque,
+					sizeof(stateid_opaque_t));
+	return 0;
+}
+
+static __be32
+nfsd4_encode_access(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_access *access)
+{
+	struct xdr_stream *xdr = &resp->xdr;
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 8);
+	if (!p)
+		return nfserr_resource;
+	*p++ = cpu_to_be32(access->ac_supported);
+	*p++ = cpu_to_be32(access->ac_resp_access);
+	return 0;
+}
+
+static __be32 nfsd4_encode_bind_conn_to_session(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_bind_conn_to_session *bcts)
+{
+	struct xdr_stream *xdr = &resp->xdr;
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN + 8);
+	if (!p)
+		return nfserr_resource;
+	p = xdr_encode_opaque_fixed(p, bcts->sessionid.data,
+					NFS4_MAX_SESSIONID_LEN);
+	*p++ = cpu_to_be32(bcts->dir);
+	/* Upshifting from TCP to RDMA is not supported */
+	*p++ = cpu_to_be32(0);
+	return 0;
+}
+
+static __be32
+nfsd4_encode_close(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_close *close)
+{
+	struct xdr_stream *xdr = &resp->xdr;
+
+	return nfsd4_encode_stateid(xdr, &close->cl_stateid);
+}
+
+
+static __be32
+nfsd4_encode_commit(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_commit *commit)
+{
+	struct xdr_stream *xdr = &resp->xdr;
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, NFS4_VERIFIER_SIZE);
+	if (!p)
+		return nfserr_resource;
+	p = xdr_encode_opaque_fixed(p, commit->co_verf.data,
+						NFS4_VERIFIER_SIZE);
+	return 0;
+}
+
+static __be32
+nfsd4_encode_create(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_create *create)
+{
+	struct xdr_stream *xdr = &resp->xdr;
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 20);
+	if (!p)
+		return nfserr_resource;
+	encode_cinfo(p, &create->cr_cinfo);
+	return nfsd4_encode_bitmap(xdr, create->cr_bmval[0],
+			create->cr_bmval[1], create->cr_bmval[2]);
+}
+
+static __be32
+nfsd4_encode_getattr(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_getattr *getattr)
+{
+	struct svc_fh *fhp = getattr->ga_fhp;
+	struct xdr_stream *xdr = &resp->xdr;
+
+	return nfsd4_encode_fattr(xdr, fhp, fhp->fh_export, fhp->fh_dentry,
+				    getattr->ga_bmval, resp->rqstp, 0);
+}
+
+static __be32
+nfsd4_encode_getfh(struct nfsd4_compoundres *resp, __be32 nfserr, struct svc_fh **fhpp)
+{
+	struct xdr_stream *xdr = &resp->xdr;
+	struct svc_fh *fhp = *fhpp;
+	unsigned int len;
+	__be32 *p;
+
+	len = fhp->fh_handle.fh_size;
+	p = xdr_reserve_space(xdr, len + 4);
+	if (!p)
+		return nfserr_resource;
+	p = xdr_encode_opaque(p, &fhp->fh_handle.fh_base, len);
+	return 0;
+}
+
+/*
+* Including all fields other than the name, a LOCK4denied structure requires
+*   8(clientid) + 4(namelen) + 8(offset) + 8(length) + 4(type) = 32 bytes.
+*/
+static __be32
+nfsd4_encode_lock_denied(struct xdr_stream *xdr, struct nfsd4_lock_denied *ld)
+{
+	struct xdr_netobj *conf = &ld->ld_owner;
+	__be32 *p;
+
+again:
+	p = xdr_reserve_space(xdr, 32 + XDR_LEN(conf->len));
+	if (!p) {
+		/*
+		 * Don't fail to return the result just because we can't
+		 * return the conflicting open:
+		 */
+		if (conf->len) {
+			kfree(conf->data);
+			conf->len = 0;
+			conf->data = NULL;
+			goto again;
+		}
+		return nfserr_resource;
+	}
+	p = xdr_encode_hyper(p, ld->ld_start);
+	p = xdr_encode_hyper(p, ld->ld_length);
+	*p++ = cpu_to_be32(ld->ld_type);
+	if (conf->len) {
+		p = xdr_encode_opaque_fixed(p, &ld->ld_clientid, 8);
+		p = xdr_encode_opaque(p, conf->data, conf->len);
+		kfree(conf->data);
+	}  else {  /* non - nfsv4 lock in conflict, no clientid nor owner */
+		p = xdr_encode_hyper(p, (u64)0); /* clientid */
+		*p++ = cpu_to_be32(0); /* length of owner name */
+	}
+	return nfserr_denied;
+}
+
+static __be32
+nfsd4_encode_lock(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_lock *lock)
+{
+	struct xdr_stream *xdr = &resp->xdr;
+
+	if (!nfserr)
+		nfserr = nfsd4_encode_stateid(xdr, &lock->lk_resp_stateid);
+	else if (nfserr == nfserr_denied)
+		nfserr = nfsd4_encode_lock_denied(xdr, &lock->lk_denied);
+
+	return nfserr;
+}
+
+static __be32
+nfsd4_encode_lockt(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_lockt *lockt)
+{
+	struct xdr_stream *xdr = &resp->xdr;
+
+	if (nfserr == nfserr_denied)
+		nfsd4_encode_lock_denied(xdr, &lockt->lt_denied);
+	return nfserr;
+}
+
+static __be32
+nfsd4_encode_locku(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_locku *locku)
+{
+	struct xdr_stream *xdr = &resp->xdr;
+
+	return nfsd4_encode_stateid(xdr, &locku->lu_stateid);
+}
+
+
+static __be32
+nfsd4_encode_link(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_link *link)
+{
+	struct xdr_stream *xdr = &resp->xdr;
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 20);
+	if (!p)
+		return nfserr_resource;
+	p = encode_cinfo(p, &link->li_cinfo);
+	return 0;
+}
+
+
+static __be32
+nfsd4_encode_open(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_open *open)
+{
+	struct xdr_stream *xdr = &resp->xdr;
+	__be32 *p;
+
+	nfserr = nfsd4_encode_stateid(xdr, &open->op_stateid);
+	if (nfserr)
+		return nfserr;
+	p = xdr_reserve_space(xdr, 24);
+	if (!p)
+		return nfserr_resource;
+	p = encode_cinfo(p, &open->op_cinfo);
+	*p++ = cpu_to_be32(open->op_rflags);
+
+	nfserr = nfsd4_encode_bitmap(xdr, open->op_bmval[0], open->op_bmval[1],
+					open->op_bmval[2]);
+	if (nfserr)
+		return nfserr;
+
+	p = xdr_reserve_space(xdr, 4);
+	if (!p)
+		return nfserr_resource;
+
+	*p++ = cpu_to_be32(open->op_delegate_type);
+	switch (open->op_delegate_type) {
+	case NFS4_OPEN_DELEGATE_NONE:
+		break;
+	case NFS4_OPEN_DELEGATE_READ:
+		nfserr = nfsd4_encode_stateid(xdr, &open->op_delegate_stateid);
+		if (nfserr)
+			return nfserr;
+		p = xdr_reserve_space(xdr, 20);
+		if (!p)
+			return nfserr_resource;
+		*p++ = cpu_to_be32(open->op_recall);
+
+		/*
+		 * TODO: ACE's in delegations
+		 */
+		*p++ = cpu_to_be32(NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE);
+		*p++ = cpu_to_be32(0);
+		*p++ = cpu_to_be32(0);
+		*p++ = cpu_to_be32(0);   /* XXX: is NULL principal ok? */
+		break;
+	case NFS4_OPEN_DELEGATE_WRITE:
+		nfserr = nfsd4_encode_stateid(xdr, &open->op_delegate_stateid);
+		if (nfserr)
+			return nfserr;
+		p = xdr_reserve_space(xdr, 32);
+		if (!p)
+			return nfserr_resource;
+		*p++ = cpu_to_be32(open->op_recall);
+
+		/*
+		 * TODO: space_limit's in delegations
+		 */
+		*p++ = cpu_to_be32(NFS4_LIMIT_SIZE);
+		*p++ = cpu_to_be32(~(u32)0);
+		*p++ = cpu_to_be32(~(u32)0);
+
+		/*
+		 * TODO: ACE's in delegations
+		 */
+		*p++ = cpu_to_be32(NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE);
+		*p++ = cpu_to_be32(0);
+		*p++ = cpu_to_be32(0);
+		*p++ = cpu_to_be32(0);   /* XXX: is NULL principal ok? */
+		break;
+	case NFS4_OPEN_DELEGATE_NONE_EXT: /* 4.1 */
+		switch (open->op_why_no_deleg) {
+		case WND4_CONTENTION:
+		case WND4_RESOURCE:
+			p = xdr_reserve_space(xdr, 8);
+			if (!p)
+				return nfserr_resource;
+			*p++ = cpu_to_be32(open->op_why_no_deleg);
+			/* deleg signaling not supported yet: */
+			*p++ = cpu_to_be32(0);
+			break;
+		default:
+			p = xdr_reserve_space(xdr, 4);
+			if (!p)
+				return nfserr_resource;
+			*p++ = cpu_to_be32(open->op_why_no_deleg);
+		}
+		break;
+	default:
+		BUG();
+	}
+	/* XXX save filehandle here */
+	return 0;
+}
+
+static __be32
+nfsd4_encode_open_confirm(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_open_confirm *oc)
+{
+	struct xdr_stream *xdr = &resp->xdr;
+
+	return nfsd4_encode_stateid(xdr, &oc->oc_resp_stateid);
+}
+
+static __be32
+nfsd4_encode_open_downgrade(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_open_downgrade *od)
+{
+	struct xdr_stream *xdr = &resp->xdr;
+
+	return nfsd4_encode_stateid(xdr, &od->od_stateid);
+}
+
+static __be32 nfsd4_encode_splice_read(
+				struct nfsd4_compoundres *resp,
+				struct nfsd4_read *read,
+				struct file *file, unsigned long maxcount)
+{
+	struct xdr_stream *xdr = &resp->xdr;
+	struct xdr_buf *buf = xdr->buf;
+	u32 eof;
+	int space_left;
+	__be32 nfserr;
+	__be32 *p = xdr->p - 2;
+
+	/* Make sure there will be room for padding if needed */
+	if (xdr->end - xdr->p < 1)
+		return nfserr_resource;
+
+	nfserr = nfsd_splice_read(read->rd_rqstp, read->rd_fhp,
+				  file, read->rd_offset, &maxcount, &eof);
+	read->rd_length = maxcount;
+	if (nfserr) {
+		/*
+		 * nfsd_splice_actor may have already messed with the
+		 * page length; reset it so as not to confuse
+		 * xdr_truncate_encode:
+		 */
+		buf->page_len = 0;
+		return nfserr;
+	}
+
+	*(p++) = htonl(eof);
+	*(p++) = htonl(maxcount);
+
+	buf->page_len = maxcount;
+	buf->len += maxcount;
+	xdr->page_ptr += (buf->page_base + maxcount + PAGE_SIZE - 1)
+							/ PAGE_SIZE;
+
+	/* Use rest of head for padding and remaining ops: */
+	buf->tail[0].iov_base = xdr->p;
+	buf->tail[0].iov_len = 0;
+	xdr->iov = buf->tail;
+	if (maxcount&3) {
+		int pad = 4 - (maxcount&3);
+
+		*(xdr->p++) = 0;
+
+		buf->tail[0].iov_base += maxcount&3;
+		buf->tail[0].iov_len = pad;
+		buf->len += pad;
+	}
+
+	space_left = min_t(int, (void *)xdr->end - (void *)xdr->p,
+				buf->buflen - buf->len);
+	buf->buflen = buf->len + space_left;
+	xdr->end = (__be32 *)((void *)xdr->end + space_left);
+
+	return 0;
+}
+
+static __be32 nfsd4_encode_readv(struct nfsd4_compoundres *resp,
+				 struct nfsd4_read *read,
+				 struct file *file, unsigned long maxcount)
+{
+	struct xdr_stream *xdr = &resp->xdr;
+	u32 eof;
+	int starting_len = xdr->buf->len - 8;
+	__be32 nfserr;
+	__be32 tmp;
+	int pad;
+
+	read->rd_vlen = xdr_reserve_space_vec(xdr, resp->rqstp->rq_vec, maxcount);
+	if (read->rd_vlen < 0)
+		return nfserr_resource;
+
+	nfserr = nfsd_readv(resp->rqstp, read->rd_fhp, file, read->rd_offset,
+			    resp->rqstp->rq_vec, read->rd_vlen, &maxcount,
+			    &eof);
+	read->rd_length = maxcount;
+	if (nfserr)
+		return nfserr;
+	if (svc_encode_read_payload(resp->rqstp, starting_len + 8, maxcount))
+		return nfserr_io;
+	xdr_truncate_encode(xdr, starting_len + 8 + xdr_align_size(maxcount));
+
+	tmp = htonl(eof);
+	write_bytes_to_xdr_buf(xdr->buf, starting_len    , &tmp, 4);
+	tmp = htonl(maxcount);
+	write_bytes_to_xdr_buf(xdr->buf, starting_len + 4, &tmp, 4);
+
+	tmp = xdr_zero;
+	pad = (maxcount&3) ? 4 - (maxcount&3) : 0;
+	write_bytes_to_xdr_buf(xdr->buf, starting_len + 8 + maxcount,
+								&tmp, pad);
+	return 0;
+
+}
+
+static __be32
+nfsd4_encode_read(struct nfsd4_compoundres *resp, __be32 nfserr,
+		  struct nfsd4_read *read)
+{
+	unsigned long maxcount;
+	struct xdr_stream *xdr = &resp->xdr;
+	struct file *file;
+	int starting_len = xdr->buf->len;
+	__be32 *p;
+
+	if (nfserr)
+		return nfserr;
+	file = read->rd_nf->nf_file;
+
+	p = xdr_reserve_space(xdr, 8); /* eof flag and byte count */
+	if (!p) {
+		WARN_ON_ONCE(test_bit(RQ_SPLICE_OK, &resp->rqstp->rq_flags));
+		return nfserr_resource;
+	}
+	if (resp->xdr.buf->page_len &&
+	    test_bit(RQ_SPLICE_OK, &resp->rqstp->rq_flags)) {
+		WARN_ON_ONCE(1);
+		return nfserr_serverfault;
+	}
+	xdr_commit_encode(xdr);
+
+	maxcount = svc_max_payload(resp->rqstp);
+	maxcount = min_t(unsigned long, maxcount,
+			 (xdr->buf->buflen - xdr->buf->len));
+	maxcount = min_t(unsigned long, maxcount, read->rd_length);
+
+	if (file->f_op->splice_read &&
+	    test_bit(RQ_SPLICE_OK, &resp->rqstp->rq_flags))
+		nfserr = nfsd4_encode_splice_read(resp, read, file, maxcount);
+	else
+		nfserr = nfsd4_encode_readv(resp, read, file, maxcount);
+
+	if (nfserr)
+		xdr_truncate_encode(xdr, starting_len);
+
+	return nfserr;
+}
+
+static __be32
+nfsd4_encode_readlink(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_readlink *readlink)
+{
+	int maxcount;
+	__be32 wire_count;
+	int zero = 0;
+	struct xdr_stream *xdr = &resp->xdr;
+	int length_offset = xdr->buf->len;
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 4);
+	if (!p)
+		return nfserr_resource;
+	maxcount = PAGE_SIZE;
+
+	p = xdr_reserve_space(xdr, maxcount);
+	if (!p)
+		return nfserr_resource;
+	/*
+	 * XXX: By default, vfs_readlink() will truncate symlinks if they
+	 * would overflow the buffer.  Is this kosher in NFSv4?  If not, one
+	 * easy fix is: if vfs_readlink() precisely fills the buffer, assume
+	 * that truncation occurred, and return NFS4ERR_RESOURCE.
+	 */
+	nfserr = nfsd_readlink(readlink->rl_rqstp, readlink->rl_fhp,
+						(char *)p, &maxcount);
+	if (nfserr == nfserr_isdir)
+		nfserr = nfserr_inval;
+	if (nfserr) {
+		xdr_truncate_encode(xdr, length_offset);
+		return nfserr;
+	}
+
+	wire_count = htonl(maxcount);
+	write_bytes_to_xdr_buf(xdr->buf, length_offset, &wire_count, 4);
+	xdr_truncate_encode(xdr, length_offset + 4 + ALIGN(maxcount, 4));
+	if (maxcount & 3)
+		write_bytes_to_xdr_buf(xdr->buf, length_offset + 4 + maxcount,
+						&zero, 4 - (maxcount&3));
+	return 0;
+}
+
+static __be32
+nfsd4_encode_readdir(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_readdir *readdir)
+{
+	int maxcount;
+	int bytes_left;
+	loff_t offset;
+	__be64 wire_offset;
+	struct xdr_stream *xdr = &resp->xdr;
+	int starting_len = xdr->buf->len;
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, NFS4_VERIFIER_SIZE);
+	if (!p)
+		return nfserr_resource;
+
+	/* XXX: Following NFSv3, we ignore the READDIR verifier for now. */
+	*p++ = cpu_to_be32(0);
+	*p++ = cpu_to_be32(0);
+	resp->xdr.buf->head[0].iov_len = ((char *)resp->xdr.p)
+				- (char *)resp->xdr.buf->head[0].iov_base;
+
+	/*
+	 * Number of bytes left for directory entries allowing for the
+	 * final 8 bytes of the readdir and a following failed op:
+	 */
+	bytes_left = xdr->buf->buflen - xdr->buf->len
+			- COMPOUND_ERR_SLACK_SPACE - 8;
+	if (bytes_left < 0) {
+		nfserr = nfserr_resource;
+		goto err_no_verf;
+	}
+	maxcount = svc_max_payload(resp->rqstp);
+	maxcount = min_t(u32, readdir->rd_maxcount, maxcount);
+	/*
+	 * Note the rfc defines rd_maxcount as the size of the
+	 * READDIR4resok structure, which includes the verifier above
+	 * and the 8 bytes encoded at the end of this function:
+	 */
+	if (maxcount < 16) {
+		nfserr = nfserr_toosmall;
+		goto err_no_verf;
+	}
+	maxcount = min_t(int, maxcount-16, bytes_left);
+
+	/* RFC 3530 14.2.24 allows us to ignore dircount when it's 0: */
+	if (!readdir->rd_dircount)
+		readdir->rd_dircount = svc_max_payload(resp->rqstp);
+
+	readdir->xdr = xdr;
+	readdir->rd_maxcount = maxcount;
+	readdir->common.err = 0;
+	readdir->cookie_offset = 0;
+
+	offset = readdir->rd_cookie;
+	nfserr = nfsd_readdir(readdir->rd_rqstp, readdir->rd_fhp,
+			      &offset,
+			      &readdir->common, nfsd4_encode_dirent);
+	if (nfserr == nfs_ok &&
+	    readdir->common.err == nfserr_toosmall &&
+	    xdr->buf->len == starting_len + 8) {
+		/* nothing encoded; which limit did we hit?: */
+		if (maxcount - 16 < bytes_left)
+			/* It was the fault of rd_maxcount: */
+			nfserr = nfserr_toosmall;
+		else
+			/* We ran out of buffer space: */
+			nfserr = nfserr_resource;
+	}
+	if (nfserr)
+		goto err_no_verf;
+
+	if (readdir->cookie_offset) {
+		wire_offset = cpu_to_be64(offset);
+		write_bytes_to_xdr_buf(xdr->buf, readdir->cookie_offset,
+							&wire_offset, 8);
+	}
+
+	p = xdr_reserve_space(xdr, 8);
+	if (!p) {
+		WARN_ON_ONCE(1);
+		goto err_no_verf;
+	}
+	*p++ = 0;	/* no more entries */
+	*p++ = htonl(readdir->common.err == nfserr_eof);
+
+	return 0;
+err_no_verf:
+	xdr_truncate_encode(xdr, starting_len);
+	return nfserr;
+}
+
+static __be32
+nfsd4_encode_remove(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_remove *remove)
+{
+	struct xdr_stream *xdr = &resp->xdr;
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 20);
+	if (!p)
+		return nfserr_resource;
+	p = encode_cinfo(p, &remove->rm_cinfo);
+	return 0;
+}
+
+static __be32
+nfsd4_encode_rename(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_rename *rename)
+{
+	struct xdr_stream *xdr = &resp->xdr;
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 40);
+	if (!p)
+		return nfserr_resource;
+	p = encode_cinfo(p, &rename->rn_sinfo);
+	p = encode_cinfo(p, &rename->rn_tinfo);
+	return 0;
+}
+
+static __be32
+nfsd4_do_encode_secinfo(struct xdr_stream *xdr, struct svc_export *exp)
+{
+	u32 i, nflavs, supported;
+	struct exp_flavor_info *flavs;
+	struct exp_flavor_info def_flavs[2];
+	__be32 *p, *flavorsp;
+	static bool report = true;
+
+	if (exp->ex_nflavors) {
+		flavs = exp->ex_flavors;
+		nflavs = exp->ex_nflavors;
+	} else { /* Handling of some defaults in absence of real secinfo: */
+		flavs = def_flavs;
+		if (exp->ex_client->flavour->flavour == RPC_AUTH_UNIX) {
+			nflavs = 2;
+			flavs[0].pseudoflavor = RPC_AUTH_UNIX;
+			flavs[1].pseudoflavor = RPC_AUTH_NULL;
+		} else if (exp->ex_client->flavour->flavour == RPC_AUTH_GSS) {
+			nflavs = 1;
+			flavs[0].pseudoflavor
+					= svcauth_gss_flavor(exp->ex_client);
+		} else {
+			nflavs = 1;
+			flavs[0].pseudoflavor
+					= exp->ex_client->flavour->flavour;
+		}
+	}
+
+	supported = 0;
+	p = xdr_reserve_space(xdr, 4);
+	if (!p)
+		return nfserr_resource;
+	flavorsp = p++;		/* to be backfilled later */
+
+	for (i = 0; i < nflavs; i++) {
+		rpc_authflavor_t pf = flavs[i].pseudoflavor;
+		struct rpcsec_gss_info info;
+
+		if (rpcauth_get_gssinfo(pf, &info) == 0) {
+			supported++;
+			p = xdr_reserve_space(xdr, 4 + 4 +
+					      XDR_LEN(info.oid.len) + 4 + 4);
+			if (!p)
+				return nfserr_resource;
+			*p++ = cpu_to_be32(RPC_AUTH_GSS);
+			p = xdr_encode_opaque(p,  info.oid.data, info.oid.len);
+			*p++ = cpu_to_be32(info.qop);
+			*p++ = cpu_to_be32(info.service);
+		} else if (pf < RPC_AUTH_MAXFLAVOR) {
+			supported++;
+			p = xdr_reserve_space(xdr, 4);
+			if (!p)
+				return nfserr_resource;
+			*p++ = cpu_to_be32(pf);
+		} else {
+			if (report)
+				pr_warn("NFS: SECINFO: security flavor %u "
+					"is not supported\n", pf);
+		}
+	}
+
+	if (nflavs != supported)
+		report = false;
+	*flavorsp = htonl(supported);
+	return 0;
+}
+
+static __be32
+nfsd4_encode_secinfo(struct nfsd4_compoundres *resp, __be32 nfserr,
+		     struct nfsd4_secinfo *secinfo)
+{
+	struct xdr_stream *xdr = &resp->xdr;
+
+	return nfsd4_do_encode_secinfo(xdr, secinfo->si_exp);
+}
+
+static __be32
+nfsd4_encode_secinfo_no_name(struct nfsd4_compoundres *resp, __be32 nfserr,
+		     struct nfsd4_secinfo_no_name *secinfo)
+{
+	struct xdr_stream *xdr = &resp->xdr;
+
+	return nfsd4_do_encode_secinfo(xdr, secinfo->sin_exp);
+}
+
+/*
+ * The SETATTR encode routine is special -- it always encodes a bitmap,
+ * regardless of the error status.
+ */
+static __be32
+nfsd4_encode_setattr(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_setattr *setattr)
+{
+	struct xdr_stream *xdr = &resp->xdr;
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 16);
+	if (!p)
+		return nfserr_resource;
+	if (nfserr) {
+		*p++ = cpu_to_be32(3);
+		*p++ = cpu_to_be32(0);
+		*p++ = cpu_to_be32(0);
+		*p++ = cpu_to_be32(0);
+	}
+	else {
+		*p++ = cpu_to_be32(3);
+		*p++ = cpu_to_be32(setattr->sa_bmval[0]);
+		*p++ = cpu_to_be32(setattr->sa_bmval[1]);
+		*p++ = cpu_to_be32(setattr->sa_bmval[2]);
+	}
+	return nfserr;
+}
+
+static __be32
+nfsd4_encode_setclientid(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_setclientid *scd)
+{
+	struct xdr_stream *xdr = &resp->xdr;
+	__be32 *p;
+
+	if (!nfserr) {
+		p = xdr_reserve_space(xdr, 8 + NFS4_VERIFIER_SIZE);
+		if (!p)
+			return nfserr_resource;
+		p = xdr_encode_opaque_fixed(p, &scd->se_clientid, 8);
+		p = xdr_encode_opaque_fixed(p, &scd->se_confirm,
+						NFS4_VERIFIER_SIZE);
+	}
+	else if (nfserr == nfserr_clid_inuse) {
+		p = xdr_reserve_space(xdr, 8);
+		if (!p)
+			return nfserr_resource;
+		*p++ = cpu_to_be32(0);
+		*p++ = cpu_to_be32(0);
+	}
+	return nfserr;
+}
+
+static __be32
+nfsd4_encode_write(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_write *write)
+{
+	struct xdr_stream *xdr = &resp->xdr;
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 16);
+	if (!p)
+		return nfserr_resource;
+	*p++ = cpu_to_be32(write->wr_bytes_written);
+	*p++ = cpu_to_be32(write->wr_how_written);
+	p = xdr_encode_opaque_fixed(p, write->wr_verifier.data,
+						NFS4_VERIFIER_SIZE);
+	return 0;
+}
+
+static __be32
+nfsd4_encode_exchange_id(struct nfsd4_compoundres *resp, __be32 nfserr,
+			 struct nfsd4_exchange_id *exid)
+{
+	struct xdr_stream *xdr = &resp->xdr;
+	__be32 *p;
+	char *major_id;
+	char *server_scope;
+	int major_id_sz;
+	int server_scope_sz;
+	uint64_t minor_id = 0;
+	struct nfsd_net *nn = net_generic(SVC_NET(resp->rqstp), nfsd_net_id);
+
+	major_id = nn->nfsd_name;
+	major_id_sz = strlen(nn->nfsd_name);
+	server_scope = nn->nfsd_name;
+	server_scope_sz = strlen(nn->nfsd_name);
+
+	p = xdr_reserve_space(xdr,
+		8 /* eir_clientid */ +
+		4 /* eir_sequenceid */ +
+		4 /* eir_flags */ +
+		4 /* spr_how */);
+	if (!p)
+		return nfserr_resource;
+
+	p = xdr_encode_opaque_fixed(p, &exid->clientid, 8);
+	*p++ = cpu_to_be32(exid->seqid);
+	*p++ = cpu_to_be32(exid->flags);
+
+	*p++ = cpu_to_be32(exid->spa_how);
+
+	switch (exid->spa_how) {
+	case SP4_NONE:
+		break;
+	case SP4_MACH_CRED:
+		/* spo_must_enforce bitmap: */
+		nfserr = nfsd4_encode_bitmap(xdr,
+					exid->spo_must_enforce[0],
+					exid->spo_must_enforce[1],
+					exid->spo_must_enforce[2]);
+		if (nfserr)
+			return nfserr;
+		/* spo_must_allow bitmap: */
+		nfserr = nfsd4_encode_bitmap(xdr,
+					exid->spo_must_allow[0],
+					exid->spo_must_allow[1],
+					exid->spo_must_allow[2]);
+		if (nfserr)
+			return nfserr;
+		break;
+	default:
+		WARN_ON_ONCE(1);
+	}
+
+	p = xdr_reserve_space(xdr,
+		8 /* so_minor_id */ +
+		4 /* so_major_id.len */ +
+		(XDR_QUADLEN(major_id_sz) * 4) +
+		4 /* eir_server_scope.len */ +
+		(XDR_QUADLEN(server_scope_sz) * 4) +
+		4 /* eir_server_impl_id.count (0) */);
+	if (!p)
+		return nfserr_resource;
+
+	/* The server_owner struct */
+	p = xdr_encode_hyper(p, minor_id);      /* Minor id */
+	/* major id */
+	p = xdr_encode_opaque(p, major_id, major_id_sz);
+
+	/* Server scope */
+	p = xdr_encode_opaque(p, server_scope, server_scope_sz);
+
+	/* Implementation id */
+	*p++ = cpu_to_be32(0);	/* zero length nfs_impl_id4 array */
+	return 0;
+}
+
+static __be32
+nfsd4_encode_create_session(struct nfsd4_compoundres *resp, __be32 nfserr,
+			    struct nfsd4_create_session *sess)
+{
+	struct xdr_stream *xdr = &resp->xdr;
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 24);
+	if (!p)
+		return nfserr_resource;
+	p = xdr_encode_opaque_fixed(p, sess->sessionid.data,
+					NFS4_MAX_SESSIONID_LEN);
+	*p++ = cpu_to_be32(sess->seqid);
+	*p++ = cpu_to_be32(sess->flags);
+
+	p = xdr_reserve_space(xdr, 28);
+	if (!p)
+		return nfserr_resource;
+	*p++ = cpu_to_be32(0); /* headerpadsz */
+	*p++ = cpu_to_be32(sess->fore_channel.maxreq_sz);
+	*p++ = cpu_to_be32(sess->fore_channel.maxresp_sz);
+	*p++ = cpu_to_be32(sess->fore_channel.maxresp_cached);
+	*p++ = cpu_to_be32(sess->fore_channel.maxops);
+	*p++ = cpu_to_be32(sess->fore_channel.maxreqs);
+	*p++ = cpu_to_be32(sess->fore_channel.nr_rdma_attrs);
+
+	if (sess->fore_channel.nr_rdma_attrs) {
+		p = xdr_reserve_space(xdr, 4);
+		if (!p)
+			return nfserr_resource;
+		*p++ = cpu_to_be32(sess->fore_channel.rdma_attrs);
+	}
+
+	p = xdr_reserve_space(xdr, 28);
+	if (!p)
+		return nfserr_resource;
+	*p++ = cpu_to_be32(0); /* headerpadsz */
+	*p++ = cpu_to_be32(sess->back_channel.maxreq_sz);
+	*p++ = cpu_to_be32(sess->back_channel.maxresp_sz);
+	*p++ = cpu_to_be32(sess->back_channel.maxresp_cached);
+	*p++ = cpu_to_be32(sess->back_channel.maxops);
+	*p++ = cpu_to_be32(sess->back_channel.maxreqs);
+	*p++ = cpu_to_be32(sess->back_channel.nr_rdma_attrs);
+
+	if (sess->back_channel.nr_rdma_attrs) {
+		p = xdr_reserve_space(xdr, 4);
+		if (!p)
+			return nfserr_resource;
+		*p++ = cpu_to_be32(sess->back_channel.rdma_attrs);
+	}
+	return 0;
+}
+
+static __be32
+nfsd4_encode_sequence(struct nfsd4_compoundres *resp, __be32 nfserr,
+		      struct nfsd4_sequence *seq)
+{
+	struct xdr_stream *xdr = &resp->xdr;
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN + 20);
+	if (!p)
+		return nfserr_resource;
+	p = xdr_encode_opaque_fixed(p, seq->sessionid.data,
+					NFS4_MAX_SESSIONID_LEN);
+	*p++ = cpu_to_be32(seq->seqid);
+	*p++ = cpu_to_be32(seq->slotid);
+	/* Note slotid's are numbered from zero: */
+	*p++ = cpu_to_be32(seq->maxslots - 1); /* sr_highest_slotid */
+	*p++ = cpu_to_be32(seq->maxslots - 1); /* sr_target_highest_slotid */
+	*p++ = cpu_to_be32(seq->status_flags);
+
+	resp->cstate.data_offset = xdr->buf->len; /* DRC cache data pointer */
+	return 0;
+}
+
+static __be32
+nfsd4_encode_test_stateid(struct nfsd4_compoundres *resp, __be32 nfserr,
+			  struct nfsd4_test_stateid *test_stateid)
+{
+	struct xdr_stream *xdr = &resp->xdr;
+	struct nfsd4_test_stateid_id *stateid, *next;
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 4 + (4 * test_stateid->ts_num_ids));
+	if (!p)
+		return nfserr_resource;
+	*p++ = htonl(test_stateid->ts_num_ids);
+
+	list_for_each_entry_safe(stateid, next, &test_stateid->ts_stateid_list, ts_id_list) {
+		*p++ = stateid->ts_id_status;
+	}
+
+	return 0;
+}
+
+#ifdef CONFIG_NFSD_PNFS
+static __be32
+nfsd4_encode_getdeviceinfo(struct nfsd4_compoundres *resp, __be32 nfserr,
+		struct nfsd4_getdeviceinfo *gdev)
+{
+	struct xdr_stream *xdr = &resp->xdr;
+	const struct nfsd4_layout_ops *ops;
+	u32 starting_len = xdr->buf->len, needed_len;
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 4);
+	if (!p)
+		return nfserr_resource;
+
+	*p++ = cpu_to_be32(gdev->gd_layout_type);
+
+	ops = nfsd4_layout_ops[gdev->gd_layout_type];
+	nfserr = ops->encode_getdeviceinfo(xdr, gdev);
+	if (nfserr) {
+		/*
+		 * We don't bother to burden the layout drivers with
+		 * enforcing gd_maxcount, just tell the client to
+		 * come back with a bigger buffer if it's not enough.
+		 */
+		if (xdr->buf->len + 4 > gdev->gd_maxcount)
+			goto toosmall;
+		return nfserr;
+	}
+
+	if (gdev->gd_notify_types) {
+		p = xdr_reserve_space(xdr, 4 + 4);
+		if (!p)
+			return nfserr_resource;
+		*p++ = cpu_to_be32(1);			/* bitmap length */
+		*p++ = cpu_to_be32(gdev->gd_notify_types);
+	} else {
+		p = xdr_reserve_space(xdr, 4);
+		if (!p)
+			return nfserr_resource;
+		*p++ = 0;
+	}
+
+	return 0;
+toosmall:
+	dprintk("%s: maxcount too small\n", __func__);
+	needed_len = xdr->buf->len + 4 /* notifications */;
+	xdr_truncate_encode(xdr, starting_len);
+	p = xdr_reserve_space(xdr, 4);
+	if (!p)
+		return nfserr_resource;
+	*p++ = cpu_to_be32(needed_len);
+	return nfserr_toosmall;
+}
+
+static __be32
+nfsd4_encode_layoutget(struct nfsd4_compoundres *resp, __be32 nfserr,
+		struct nfsd4_layoutget *lgp)
+{
+	struct xdr_stream *xdr = &resp->xdr;
+	const struct nfsd4_layout_ops *ops;
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 36 + sizeof(stateid_opaque_t));
+	if (!p)
+		return nfserr_resource;
+
+	*p++ = cpu_to_be32(1);	/* we always set return-on-close */
+	*p++ = cpu_to_be32(lgp->lg_sid.si_generation);
+	p = xdr_encode_opaque_fixed(p, &lgp->lg_sid.si_opaque,
+				    sizeof(stateid_opaque_t));
+
+	*p++ = cpu_to_be32(1);	/* we always return a single layout */
+	p = xdr_encode_hyper(p, lgp->lg_seg.offset);
+	p = xdr_encode_hyper(p, lgp->lg_seg.length);
+	*p++ = cpu_to_be32(lgp->lg_seg.iomode);
+	*p++ = cpu_to_be32(lgp->lg_layout_type);
+
+	ops = nfsd4_layout_ops[lgp->lg_layout_type];
+	return ops->encode_layoutget(xdr, lgp);
+}
+
+static __be32
+nfsd4_encode_layoutcommit(struct nfsd4_compoundres *resp, __be32 nfserr,
+			  struct nfsd4_layoutcommit *lcp)
+{
+	struct xdr_stream *xdr = &resp->xdr;
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 4);
+	if (!p)
+		return nfserr_resource;
+	*p++ = cpu_to_be32(lcp->lc_size_chg);
+	if (lcp->lc_size_chg) {
+		p = xdr_reserve_space(xdr, 8);
+		if (!p)
+			return nfserr_resource;
+		p = xdr_encode_hyper(p, lcp->lc_newsize);
+	}
+
+	return 0;
+}
+
+static __be32
+nfsd4_encode_layoutreturn(struct nfsd4_compoundres *resp, __be32 nfserr,
+		struct nfsd4_layoutreturn *lrp)
+{
+	struct xdr_stream *xdr = &resp->xdr;
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 4);
+	if (!p)
+		return nfserr_resource;
+	*p++ = cpu_to_be32(lrp->lrs_present);
+	if (lrp->lrs_present)
+		return nfsd4_encode_stateid(xdr, &lrp->lr_sid);
+	return 0;
+}
+#endif /* CONFIG_NFSD_PNFS */
+
+static __be32
+nfsd42_encode_write_res(struct nfsd4_compoundres *resp,
+		struct nfsd42_write_res *write, bool sync)
+{
+	__be32 *p;
+	p = xdr_reserve_space(&resp->xdr, 4);
+	if (!p)
+		return nfserr_resource;
+
+	if (sync)
+		*p++ = cpu_to_be32(0);
+	else {
+		__be32 nfserr;
+		*p++ = cpu_to_be32(1);
+		nfserr = nfsd4_encode_stateid(&resp->xdr, &write->cb_stateid);
+		if (nfserr)
+			return nfserr;
+	}
+	p = xdr_reserve_space(&resp->xdr, 8 + 4 + NFS4_VERIFIER_SIZE);
+	if (!p)
+		return nfserr_resource;
+
+	p = xdr_encode_hyper(p, write->wr_bytes_written);
+	*p++ = cpu_to_be32(write->wr_stable_how);
+	p = xdr_encode_opaque_fixed(p, write->wr_verifier.data,
+				    NFS4_VERIFIER_SIZE);
+	return nfs_ok;
+}
+
+static __be32
+nfsd42_encode_nl4_server(struct nfsd4_compoundres *resp, struct nl4_server *ns)
+{
+	struct xdr_stream *xdr = &resp->xdr;
+	struct nfs42_netaddr *addr;
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 4);
+	*p++ = cpu_to_be32(ns->nl4_type);
+
+	switch (ns->nl4_type) {
+	case NL4_NETADDR:
+		addr = &ns->u.nl4_addr;
+
+		/* netid_len, netid, uaddr_len, uaddr (port included
+		 * in RPCBIND_MAXUADDRLEN)
+		 */
+		p = xdr_reserve_space(xdr,
+			4 /* netid len */ +
+			(XDR_QUADLEN(addr->netid_len) * 4) +
+			4 /* uaddr len */ +
+			(XDR_QUADLEN(addr->addr_len) * 4));
+		if (!p)
+			return nfserr_resource;
+
+		*p++ = cpu_to_be32(addr->netid_len);
+		p = xdr_encode_opaque_fixed(p, addr->netid,
+					    addr->netid_len);
+		*p++ = cpu_to_be32(addr->addr_len);
+		p = xdr_encode_opaque_fixed(p, addr->addr,
+					addr->addr_len);
+		break;
+	default:
+		WARN_ON_ONCE(ns->nl4_type != NL4_NETADDR);
+		return nfserr_inval;
+	}
+
+	return 0;
+}
+
+static __be32
+nfsd4_encode_copy(struct nfsd4_compoundres *resp, __be32 nfserr,
+		  struct nfsd4_copy *copy)
+{
+	__be32 *p;
+
+	nfserr = nfsd42_encode_write_res(resp, &copy->cp_res,
+			copy->cp_synchronous);
+	if (nfserr)
+		return nfserr;
+
+	p = xdr_reserve_space(&resp->xdr, 4 + 4);
+	*p++ = xdr_one; /* cr_consecutive */
+	*p++ = cpu_to_be32(copy->cp_synchronous);
+	return 0;
+}
+
+static __be32
+nfsd4_encode_offload_status(struct nfsd4_compoundres *resp, __be32 nfserr,
+			    struct nfsd4_offload_status *os)
+{
+	struct xdr_stream *xdr = &resp->xdr;
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 8 + 4);
+	if (!p)
+		return nfserr_resource;
+	p = xdr_encode_hyper(p, os->count);
+	*p++ = cpu_to_be32(0);
+	return nfserr;
+}
+
+static __be32
+nfsd4_encode_read_plus_data(struct nfsd4_compoundres *resp,
+			    struct nfsd4_read *read,
+			    unsigned long *maxcount, u32 *eof,
+			    loff_t *pos)
+{
+	struct xdr_stream *xdr = &resp->xdr;
+	struct file *file = read->rd_nf->nf_file;
+	int starting_len = xdr->buf->len;
+	loff_t hole_pos;
+	__be32 nfserr;
+	__be32 *p, tmp;
+	__be64 tmp64;
+
+	hole_pos = pos ? *pos : vfs_llseek(file, read->rd_offset, SEEK_HOLE);
+	if (hole_pos > read->rd_offset)
+		*maxcount = min_t(unsigned long, *maxcount, hole_pos - read->rd_offset);
+	*maxcount = min_t(unsigned long, *maxcount, (xdr->buf->buflen - xdr->buf->len));
+
+	/* Content type, offset, byte count */
+	p = xdr_reserve_space(xdr, 4 + 8 + 4);
+	if (!p)
+		return nfserr_resource;
+
+	read->rd_vlen = xdr_reserve_space_vec(xdr, resp->rqstp->rq_vec, *maxcount);
+	if (read->rd_vlen < 0)
+		return nfserr_resource;
+
+	nfserr = nfsd_readv(resp->rqstp, read->rd_fhp, file, read->rd_offset,
+			    resp->rqstp->rq_vec, read->rd_vlen, maxcount, eof);
+	if (nfserr)
+		return nfserr;
+	xdr_truncate_encode(xdr, starting_len + 16 + xdr_align_size(*maxcount));
+
+	tmp = htonl(NFS4_CONTENT_DATA);
+	write_bytes_to_xdr_buf(xdr->buf, starting_len,      &tmp,   4);
+	tmp64 = cpu_to_be64(read->rd_offset);
+	write_bytes_to_xdr_buf(xdr->buf, starting_len + 4,  &tmp64, 8);
+	tmp = htonl(*maxcount);
+	write_bytes_to_xdr_buf(xdr->buf, starting_len + 12, &tmp,   4);
+
+	tmp = xdr_zero;
+	write_bytes_to_xdr_buf(xdr->buf, starting_len + 16 + *maxcount, &tmp,
+			       xdr_pad_size(*maxcount));
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_encode_read_plus_hole(struct nfsd4_compoundres *resp,
+			    struct nfsd4_read *read,
+			    unsigned long *maxcount, u32 *eof)
+{
+	struct file *file = read->rd_nf->nf_file;
+	loff_t data_pos = vfs_llseek(file, read->rd_offset, SEEK_DATA);
+	loff_t f_size = i_size_read(file_inode(file));
+	unsigned long count;
+	__be32 *p;
+
+	if (data_pos == -ENXIO)
+		data_pos = f_size;
+	else if (data_pos <= read->rd_offset || (data_pos < f_size && data_pos % PAGE_SIZE))
+		return nfsd4_encode_read_plus_data(resp, read, maxcount, eof, &f_size);
+	count = data_pos - read->rd_offset;
+
+	/* Content type, offset, byte count */
+	p = xdr_reserve_space(&resp->xdr, 4 + 8 + 8);
+	if (!p)
+		return nfserr_resource;
+
+	*p++ = htonl(NFS4_CONTENT_HOLE);
+	 p   = xdr_encode_hyper(p, read->rd_offset);
+	 p   = xdr_encode_hyper(p, count);
+
+	*eof = (read->rd_offset + count) >= f_size;
+	*maxcount = min_t(unsigned long, count, *maxcount);
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_encode_read_plus(struct nfsd4_compoundres *resp, __be32 nfserr,
+		       struct nfsd4_read *read)
+{
+	unsigned long maxcount, count;
+	struct xdr_stream *xdr = &resp->xdr;
+	struct file *file;
+	int starting_len = xdr->buf->len;
+	int last_segment = xdr->buf->len;
+	int segments = 0;
+	__be32 *p, tmp;
+	bool is_data;
+	loff_t pos;
+	u32 eof;
+
+	if (nfserr)
+		return nfserr;
+	file = read->rd_nf->nf_file;
+
+	/* eof flag, segment count */
+	p = xdr_reserve_space(xdr, 4 + 4);
+	if (!p)
+		return nfserr_resource;
+	xdr_commit_encode(xdr);
+
+	maxcount = svc_max_payload(resp->rqstp);
+	maxcount = min_t(unsigned long, maxcount,
+			 (xdr->buf->buflen - xdr->buf->len));
+	maxcount = min_t(unsigned long, maxcount, read->rd_length);
+	count    = maxcount;
+
+	eof = read->rd_offset >= i_size_read(file_inode(file));
+	if (eof)
+		goto out;
+
+	pos = vfs_llseek(file, read->rd_offset, SEEK_HOLE);
+	is_data = pos > read->rd_offset;
+
+	while (count > 0 && !eof) {
+		maxcount = count;
+		if (is_data)
+			nfserr = nfsd4_encode_read_plus_data(resp, read, &maxcount, &eof,
+						segments == 0 ? &pos : NULL);
+		else
+			nfserr = nfsd4_encode_read_plus_hole(resp, read, &maxcount, &eof);
+		if (nfserr)
+			goto out;
+		count -= maxcount;
+		read->rd_offset += maxcount;
+		is_data = !is_data;
+		last_segment = xdr->buf->len;
+		segments++;
+	}
+
+out:
+	if (nfserr && segments == 0)
+		xdr_truncate_encode(xdr, starting_len);
+	else {
+		if (nfserr) {
+			xdr_truncate_encode(xdr, last_segment);
+			nfserr = nfs_ok;
+			eof = 0;
+		}
+		tmp = htonl(eof);
+		write_bytes_to_xdr_buf(xdr->buf, starting_len,     &tmp, 4);
+		tmp = htonl(segments);
+		write_bytes_to_xdr_buf(xdr->buf, starting_len + 4, &tmp, 4);
+	}
+
+	return nfserr;
+}
+
+static __be32
+nfsd4_encode_copy_notify(struct nfsd4_compoundres *resp, __be32 nfserr,
+			 struct nfsd4_copy_notify *cn)
+{
+	struct xdr_stream *xdr = &resp->xdr;
+	__be32 *p;
+
+	if (nfserr)
+		return nfserr;
+
+	/* 8 sec, 4 nsec */
+	p = xdr_reserve_space(xdr, 12);
+	if (!p)
+		return nfserr_resource;
+
+	/* cnr_lease_time */
+	p = xdr_encode_hyper(p, cn->cpn_sec);
+	*p++ = cpu_to_be32(cn->cpn_nsec);
+
+	/* cnr_stateid */
+	nfserr = nfsd4_encode_stateid(xdr, &cn->cpn_cnr_stateid);
+	if (nfserr)
+		return nfserr;
+
+	/* cnr_src.nl_nsvr */
+	p = xdr_reserve_space(xdr, 4);
+	if (!p)
+		return nfserr_resource;
+
+	*p++ = cpu_to_be32(1);
+
+	return nfsd42_encode_nl4_server(resp, &cn->cpn_src);
+}
+
+static __be32
+nfsd4_encode_seek(struct nfsd4_compoundres *resp, __be32 nfserr,
+		  struct nfsd4_seek *seek)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(&resp->xdr, 4 + 8);
+	*p++ = cpu_to_be32(seek->seek_eof);
+	p = xdr_encode_hyper(p, seek->seek_pos);
+
+	return 0;
+}
+
+static __be32
+nfsd4_encode_noop(struct nfsd4_compoundres *resp, __be32 nfserr, void *p)
+{
+	return nfserr;
+}
+
+/*
+ * Encode kmalloc-ed buffer in to XDR stream.
+ */
+static __be32
+nfsd4_vbuf_to_stream(struct xdr_stream *xdr, char *buf, u32 buflen)
+{
+	u32 cplen;
+	__be32 *p;
+
+	cplen = min_t(unsigned long, buflen,
+		      ((void *)xdr->end - (void *)xdr->p));
+	p = xdr_reserve_space(xdr, cplen);
+	if (!p)
+		return nfserr_resource;
+
+	memcpy(p, buf, cplen);
+	buf += cplen;
+	buflen -= cplen;
+
+	while (buflen) {
+		cplen = min_t(u32, buflen, PAGE_SIZE);
+		p = xdr_reserve_space(xdr, cplen);
+		if (!p)
+			return nfserr_resource;
+
+		memcpy(p, buf, cplen);
+
+		if (cplen < PAGE_SIZE) {
+			/*
+			 * We're done, with a length that wasn't page
+			 * aligned, so possibly not word aligned. Pad
+			 * any trailing bytes with 0.
+			 */
+			xdr_encode_opaque_fixed(p, NULL, cplen);
+			break;
+		}
+
+		buflen -= PAGE_SIZE;
+		buf += PAGE_SIZE;
+	}
+
+	return 0;
+}
+
+static __be32
+nfsd4_encode_getxattr(struct nfsd4_compoundres *resp, __be32 nfserr,
+		      struct nfsd4_getxattr *getxattr)
+{
+	struct xdr_stream *xdr = &resp->xdr;
+	__be32 *p, err;
+
+	p = xdr_reserve_space(xdr, 4);
+	if (!p)
+		return nfserr_resource;
+
+	*p = cpu_to_be32(getxattr->getxa_len);
+
+	if (getxattr->getxa_len == 0)
+		return 0;
+
+	err = nfsd4_vbuf_to_stream(xdr, getxattr->getxa_buf,
+				    getxattr->getxa_len);
+
+	kvfree(getxattr->getxa_buf);
+
+	return err;
+}
+
+static __be32
+nfsd4_encode_setxattr(struct nfsd4_compoundres *resp, __be32 nfserr,
+		      struct nfsd4_setxattr *setxattr)
+{
+	struct xdr_stream *xdr = &resp->xdr;
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 20);
+	if (!p)
+		return nfserr_resource;
+
+	encode_cinfo(p, &setxattr->setxa_cinfo);
+
+	return 0;
+}
+
+/*
+ * See if there are cookie values that can be rejected outright.
+ */
+static __be32
+nfsd4_listxattr_validate_cookie(struct nfsd4_listxattrs *listxattrs,
+				u32 *offsetp)
+{
+	u64 cookie = listxattrs->lsxa_cookie;
+
+	/*
+	 * If the cookie is larger than the maximum number we can fit
+	 * in either the buffer we just got back from vfs_listxattr, or,
+	 * XDR-encoded, in the return buffer, it's invalid.
+	 */
+	if (cookie > (listxattrs->lsxa_len) / (XATTR_USER_PREFIX_LEN + 2))
+		return nfserr_badcookie;
+
+	if (cookie > (listxattrs->lsxa_maxcount /
+		      (XDR_QUADLEN(XATTR_USER_PREFIX_LEN + 2) + 4)))
+		return nfserr_badcookie;
+
+	*offsetp = (u32)cookie;
+	return 0;
+}
+
+static __be32
+nfsd4_encode_listxattrs(struct nfsd4_compoundres *resp, __be32 nfserr,
+			struct nfsd4_listxattrs *listxattrs)
+{
+	struct xdr_stream *xdr = &resp->xdr;
+	u32 cookie_offset, count_offset, eof;
+	u32 left, xdrleft, slen, count;
+	u32 xdrlen, offset;
+	u64 cookie;
+	char *sp;
+	__be32 status, tmp;
+	__be32 *p;
+	u32 nuser;
+
+	eof = 1;
+
+	status = nfsd4_listxattr_validate_cookie(listxattrs, &offset);
+	if (status)
+		goto out;
+
+	/*
+	 * Reserve space for the cookie and the name array count. Record
+	 * the offsets to save them later.
+	 */
+	cookie_offset = xdr->buf->len;
+	count_offset = cookie_offset + 8;
+	p = xdr_reserve_space(xdr, 12);
+	if (!p) {
+		status = nfserr_resource;
+		goto out;
+	}
+
+	count = 0;
+	left = listxattrs->lsxa_len;
+	sp = listxattrs->lsxa_buf;
+	nuser = 0;
+
+	xdrleft = listxattrs->lsxa_maxcount;
+
+	while (left > 0 && xdrleft > 0) {
+		slen = strlen(sp);
+
+		/*
+		 * Check if this is a "user." attribute, skip it if not.
+		 */
+		if (strncmp(sp, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN))
+			goto contloop;
+
+		slen -= XATTR_USER_PREFIX_LEN;
+		xdrlen = 4 + ((slen + 3) & ~3);
+		if (xdrlen > xdrleft) {
+			if (count == 0) {
+				/*
+				 * Can't even fit the first attribute name.
+				 */
+				status = nfserr_toosmall;
+				goto out;
+			}
+			eof = 0;
+			goto wreof;
+		}
+
+		left -= XATTR_USER_PREFIX_LEN;
+		sp += XATTR_USER_PREFIX_LEN;
+		if (nuser++ < offset)
+			goto contloop;
+
+
+		p = xdr_reserve_space(xdr, xdrlen);
+		if (!p) {
+			status = nfserr_resource;
+			goto out;
+		}
+
+		xdr_encode_opaque(p, sp, slen);
+
+		xdrleft -= xdrlen;
+		count++;
+contloop:
+		sp += slen + 1;
+		left -= slen + 1;
+	}
+
+	/*
+	 * If there were user attributes to copy, but we didn't copy
+	 * any, the offset was too large (e.g. the cookie was invalid).
+	 */
+	if (nuser > 0 && count == 0) {
+		status = nfserr_badcookie;
+		goto out;
+	}
+
+wreof:
+	p = xdr_reserve_space(xdr, 4);
+	if (!p) {
+		status = nfserr_resource;
+		goto out;
+	}
+	*p = cpu_to_be32(eof);
+
+	cookie = offset + count;
+
+	write_bytes_to_xdr_buf(xdr->buf, cookie_offset, &cookie, 8);
+	tmp = cpu_to_be32(count);
+	write_bytes_to_xdr_buf(xdr->buf, count_offset, &tmp, 4);
+out:
+	if (listxattrs->lsxa_len)
+		kvfree(listxattrs->lsxa_buf);
+	return status;
+}
+
+static __be32
+nfsd4_encode_removexattr(struct nfsd4_compoundres *resp, __be32 nfserr,
+			 struct nfsd4_removexattr *removexattr)
+{
+	struct xdr_stream *xdr = &resp->xdr;
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 20);
+	if (!p)
+		return nfserr_resource;
+
+	p = encode_cinfo(p, &removexattr->rmxa_cinfo);
+	return 0;
+}
+
+typedef __be32(* nfsd4_enc)(struct nfsd4_compoundres *, __be32, void *);
+
+/*
+ * Note: nfsd4_enc_ops vector is shared for v4.0 and v4.1
+ * since we don't need to filter out obsolete ops as this is
+ * done in the decoding phase.
+ */
+static const nfsd4_enc nfsd4_enc_ops[] = {
+	[OP_ACCESS]		= (nfsd4_enc)nfsd4_encode_access,
+	[OP_CLOSE]		= (nfsd4_enc)nfsd4_encode_close,
+	[OP_COMMIT]		= (nfsd4_enc)nfsd4_encode_commit,
+	[OP_CREATE]		= (nfsd4_enc)nfsd4_encode_create,
+	[OP_DELEGPURGE]		= (nfsd4_enc)nfsd4_encode_noop,
+	[OP_DELEGRETURN]	= (nfsd4_enc)nfsd4_encode_noop,
+	[OP_GETATTR]		= (nfsd4_enc)nfsd4_encode_getattr,
+	[OP_GETFH]		= (nfsd4_enc)nfsd4_encode_getfh,
+	[OP_LINK]		= (nfsd4_enc)nfsd4_encode_link,
+	[OP_LOCK]		= (nfsd4_enc)nfsd4_encode_lock,
+	[OP_LOCKT]		= (nfsd4_enc)nfsd4_encode_lockt,
+	[OP_LOCKU]		= (nfsd4_enc)nfsd4_encode_locku,
+	[OP_LOOKUP]		= (nfsd4_enc)nfsd4_encode_noop,
+	[OP_LOOKUPP]		= (nfsd4_enc)nfsd4_encode_noop,
+	[OP_NVERIFY]		= (nfsd4_enc)nfsd4_encode_noop,
+	[OP_OPEN]		= (nfsd4_enc)nfsd4_encode_open,
+	[OP_OPENATTR]		= (nfsd4_enc)nfsd4_encode_noop,
+	[OP_OPEN_CONFIRM]	= (nfsd4_enc)nfsd4_encode_open_confirm,
+	[OP_OPEN_DOWNGRADE]	= (nfsd4_enc)nfsd4_encode_open_downgrade,
+	[OP_PUTFH]		= (nfsd4_enc)nfsd4_encode_noop,
+	[OP_PUTPUBFH]		= (nfsd4_enc)nfsd4_encode_noop,
+	[OP_PUTROOTFH]		= (nfsd4_enc)nfsd4_encode_noop,
+	[OP_READ]		= (nfsd4_enc)nfsd4_encode_read,
+	[OP_READDIR]		= (nfsd4_enc)nfsd4_encode_readdir,
+	[OP_READLINK]		= (nfsd4_enc)nfsd4_encode_readlink,
+	[OP_REMOVE]		= (nfsd4_enc)nfsd4_encode_remove,
+	[OP_RENAME]		= (nfsd4_enc)nfsd4_encode_rename,
+	[OP_RENEW]		= (nfsd4_enc)nfsd4_encode_noop,
+	[OP_RESTOREFH]		= (nfsd4_enc)nfsd4_encode_noop,
+	[OP_SAVEFH]		= (nfsd4_enc)nfsd4_encode_noop,
+	[OP_SECINFO]		= (nfsd4_enc)nfsd4_encode_secinfo,
+	[OP_SETATTR]		= (nfsd4_enc)nfsd4_encode_setattr,
+	[OP_SETCLIENTID]	= (nfsd4_enc)nfsd4_encode_setclientid,
+	[OP_SETCLIENTID_CONFIRM] = (nfsd4_enc)nfsd4_encode_noop,
+	[OP_VERIFY]		= (nfsd4_enc)nfsd4_encode_noop,
+	[OP_WRITE]		= (nfsd4_enc)nfsd4_encode_write,
+	[OP_RELEASE_LOCKOWNER]	= (nfsd4_enc)nfsd4_encode_noop,
+
+	/* NFSv4.1 operations */
+	[OP_BACKCHANNEL_CTL]	= (nfsd4_enc)nfsd4_encode_noop,
+	[OP_BIND_CONN_TO_SESSION] = (nfsd4_enc)nfsd4_encode_bind_conn_to_session,
+	[OP_EXCHANGE_ID]	= (nfsd4_enc)nfsd4_encode_exchange_id,
+	[OP_CREATE_SESSION]	= (nfsd4_enc)nfsd4_encode_create_session,
+	[OP_DESTROY_SESSION]	= (nfsd4_enc)nfsd4_encode_noop,
+	[OP_FREE_STATEID]	= (nfsd4_enc)nfsd4_encode_noop,
+	[OP_GET_DIR_DELEGATION]	= (nfsd4_enc)nfsd4_encode_noop,
+#ifdef CONFIG_NFSD_PNFS
+	[OP_GETDEVICEINFO]	= (nfsd4_enc)nfsd4_encode_getdeviceinfo,
+	[OP_GETDEVICELIST]	= (nfsd4_enc)nfsd4_encode_noop,
+	[OP_LAYOUTCOMMIT]	= (nfsd4_enc)nfsd4_encode_layoutcommit,
+	[OP_LAYOUTGET]		= (nfsd4_enc)nfsd4_encode_layoutget,
+	[OP_LAYOUTRETURN]	= (nfsd4_enc)nfsd4_encode_layoutreturn,
+#else
+	[OP_GETDEVICEINFO]	= (nfsd4_enc)nfsd4_encode_noop,
+	[OP_GETDEVICELIST]	= (nfsd4_enc)nfsd4_encode_noop,
+	[OP_LAYOUTCOMMIT]	= (nfsd4_enc)nfsd4_encode_noop,
+	[OP_LAYOUTGET]		= (nfsd4_enc)nfsd4_encode_noop,
+	[OP_LAYOUTRETURN]	= (nfsd4_enc)nfsd4_encode_noop,
+#endif
+	[OP_SECINFO_NO_NAME]	= (nfsd4_enc)nfsd4_encode_secinfo_no_name,
+	[OP_SEQUENCE]		= (nfsd4_enc)nfsd4_encode_sequence,
+	[OP_SET_SSV]		= (nfsd4_enc)nfsd4_encode_noop,
+	[OP_TEST_STATEID]	= (nfsd4_enc)nfsd4_encode_test_stateid,
+	[OP_WANT_DELEGATION]	= (nfsd4_enc)nfsd4_encode_noop,
+	[OP_DESTROY_CLIENTID]	= (nfsd4_enc)nfsd4_encode_noop,
+	[OP_RECLAIM_COMPLETE]	= (nfsd4_enc)nfsd4_encode_noop,
+
+	/* NFSv4.2 operations */
+	[OP_ALLOCATE]		= (nfsd4_enc)nfsd4_encode_noop,
+	[OP_COPY]		= (nfsd4_enc)nfsd4_encode_copy,
+	[OP_COPY_NOTIFY]	= (nfsd4_enc)nfsd4_encode_copy_notify,
+	[OP_DEALLOCATE]		= (nfsd4_enc)nfsd4_encode_noop,
+	[OP_IO_ADVISE]		= (nfsd4_enc)nfsd4_encode_noop,
+	[OP_LAYOUTERROR]	= (nfsd4_enc)nfsd4_encode_noop,
+	[OP_LAYOUTSTATS]	= (nfsd4_enc)nfsd4_encode_noop,
+	[OP_OFFLOAD_CANCEL]	= (nfsd4_enc)nfsd4_encode_noop,
+	[OP_OFFLOAD_STATUS]	= (nfsd4_enc)nfsd4_encode_offload_status,
+	[OP_READ_PLUS]		= (nfsd4_enc)nfsd4_encode_read_plus,
+	[OP_SEEK]		= (nfsd4_enc)nfsd4_encode_seek,
+	[OP_WRITE_SAME]		= (nfsd4_enc)nfsd4_encode_noop,
+	[OP_CLONE]		= (nfsd4_enc)nfsd4_encode_noop,
+
+	/* RFC 8276 extended atributes operations */
+	[OP_GETXATTR]		= (nfsd4_enc)nfsd4_encode_getxattr,
+	[OP_SETXATTR]		= (nfsd4_enc)nfsd4_encode_setxattr,
+	[OP_LISTXATTRS]		= (nfsd4_enc)nfsd4_encode_listxattrs,
+	[OP_REMOVEXATTR]	= (nfsd4_enc)nfsd4_encode_removexattr,
+};
+
+/*
+ * Calculate whether we still have space to encode repsize bytes.
+ * There are two considerations:
+ *     - For NFS versions >=4.1, the size of the reply must stay within
+ *       session limits
+ *     - For all NFS versions, we must stay within limited preallocated
+ *       buffer space.
+ *
+ * This is called before the operation is processed, so can only provide
+ * an upper estimate.  For some nonidempotent operations (such as
+ * getattr), it's not necessarily a problem if that estimate is wrong,
+ * as we can fail it after processing without significant side effects.
+ */
+__be32 nfsd4_check_resp_size(struct nfsd4_compoundres *resp, u32 respsize)
+{
+	struct xdr_buf *buf = &resp->rqstp->rq_res;
+	struct nfsd4_slot *slot = resp->cstate.slot;
+
+	if (buf->len + respsize <= buf->buflen)
+		return nfs_ok;
+	if (!nfsd4_has_session(&resp->cstate))
+		return nfserr_resource;
+	if (slot->sl_flags & NFSD4_SLOT_CACHETHIS) {
+		WARN_ON_ONCE(1);
+		return nfserr_rep_too_big_to_cache;
+	}
+	return nfserr_rep_too_big;
+}
+
+void
+nfsd4_encode_operation(struct nfsd4_compoundres *resp, struct nfsd4_op *op)
+{
+	struct xdr_stream *xdr = &resp->xdr;
+	struct nfs4_stateowner *so = resp->cstate.replay_owner;
+	struct svc_rqst *rqstp = resp->rqstp;
+	const struct nfsd4_operation *opdesc = op->opdesc;
+	int post_err_offset;
+	nfsd4_enc encoder;
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 8);
+	if (!p) {
+		WARN_ON_ONCE(1);
+		return;
+	}
+	*p++ = cpu_to_be32(op->opnum);
+	post_err_offset = xdr->buf->len;
+
+	if (op->opnum == OP_ILLEGAL)
+		goto status;
+	if (op->status && opdesc &&
+			!(opdesc->op_flags & OP_NONTRIVIAL_ERROR_ENCODE))
+		goto status;
+	BUG_ON(op->opnum < 0 || op->opnum >= ARRAY_SIZE(nfsd4_enc_ops) ||
+	       !nfsd4_enc_ops[op->opnum]);
+	encoder = nfsd4_enc_ops[op->opnum];
+	op->status = encoder(resp, op->status, &op->u);
+	if (opdesc && opdesc->op_release)
+		opdesc->op_release(&op->u);
+	xdr_commit_encode(xdr);
+
+	/* nfsd4_check_resp_size guarantees enough room for error status */
+	if (!op->status) {
+		int space_needed = 0;
+		if (!nfsd4_last_compound_op(rqstp))
+			space_needed = COMPOUND_ERR_SLACK_SPACE;
+		op->status = nfsd4_check_resp_size(resp, space_needed);
+	}
+	if (op->status == nfserr_resource && nfsd4_has_session(&resp->cstate)) {
+		struct nfsd4_slot *slot = resp->cstate.slot;
+
+		if (slot->sl_flags & NFSD4_SLOT_CACHETHIS)
+			op->status = nfserr_rep_too_big_to_cache;
+		else
+			op->status = nfserr_rep_too_big;
+	}
+	if (op->status == nfserr_resource ||
+	    op->status == nfserr_rep_too_big ||
+	    op->status == nfserr_rep_too_big_to_cache) {
+		/*
+		 * The operation may have already been encoded or
+		 * partially encoded.  No op returns anything additional
+		 * in the case of one of these three errors, so we can
+		 * just truncate back to after the status.  But it's a
+		 * bug if we had to do this on a non-idempotent op:
+		 */
+		warn_on_nonidempotent_op(op);
+		xdr_truncate_encode(xdr, post_err_offset);
+	}
+	if (so) {
+		int len = xdr->buf->len - post_err_offset;
+
+		so->so_replay.rp_status = op->status;
+		so->so_replay.rp_buflen = len;
+		read_bytes_from_xdr_buf(xdr->buf, post_err_offset,
+						so->so_replay.rp_buf, len);
+	}
+status:
+	/* Note that op->status is already in network byte order: */
+	write_bytes_to_xdr_buf(xdr->buf, post_err_offset - 4, &op->status, 4);
+}
+
+/* 
+ * Encode the reply stored in the stateowner reply cache 
+ * 
+ * XDR note: do not encode rp->rp_buflen: the buffer contains the
+ * previously sent already encoded operation.
+ */
+void
+nfsd4_encode_replay(struct xdr_stream *xdr, struct nfsd4_op *op)
+{
+	__be32 *p;
+	struct nfs4_replay *rp = op->replay;
+
+	p = xdr_reserve_space(xdr, 8 + rp->rp_buflen);
+	if (!p) {
+		WARN_ON_ONCE(1);
+		return;
+	}
+	*p++ = cpu_to_be32(op->opnum);
+	*p++ = rp->rp_status;  /* already xdr'ed */
+
+	p = xdr_encode_opaque_fixed(p, rp->rp_buf, rp->rp_buflen);
+}
+
+int
+nfs4svc_encode_voidres(struct svc_rqst *rqstp, __be32 *p)
+{
+        return xdr_ressize_check(rqstp, p);
+}
+
+void nfsd4_release_compoundargs(struct svc_rqst *rqstp)
+{
+	struct nfsd4_compoundargs *args = rqstp->rq_argp;
+
+	if (args->ops != args->iops) {
+		kfree(args->ops);
+		args->ops = args->iops;
+	}
+	kfree(args->tmpp);
+	args->tmpp = NULL;
+	while (args->to_free) {
+		struct svcxdr_tmpbuf *tb = args->to_free;
+		args->to_free = tb->next;
+		kfree(tb);
+	}
+}
+
+int
+nfs4svc_decode_voidarg(struct svc_rqst *rqstp, __be32 *p)
+{
+	return 1;
+}
+
+int
+nfs4svc_decode_compoundargs(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd4_compoundargs *args = rqstp->rq_argp;
+
+	if (rqstp->rq_arg.head[0].iov_len % 4) {
+		/* client is nuts */
+		dprintk("%s: compound not properly padded! (peeraddr=%pISc xid=0x%x)",
+			__func__, svc_addr(rqstp), be32_to_cpu(rqstp->rq_xid));
+		return 0;
+	}
+	args->p = p;
+	args->end = rqstp->rq_arg.head[0].iov_base + rqstp->rq_arg.head[0].iov_len;
+	args->pagelist = rqstp->rq_arg.pages;
+	args->pagelen = rqstp->rq_arg.page_len;
+	args->tail = false;
+	args->tmpp = NULL;
+	args->to_free = NULL;
+	args->ops = args->iops;
+	args->rqstp = rqstp;
+
+	return !nfsd4_decode_compound(args);
+}
+
+int
+nfs4svc_encode_compoundres(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd4_compoundres *resp = rqstp->rq_resp;
+	struct xdr_buf *buf = resp->xdr.buf;
+
+	WARN_ON_ONCE(buf->len != buf->head[0].iov_len + buf->page_len +
+				 buf->tail[0].iov_len);
+
+	*p = resp->cstate.status;
+
+	rqstp->rq_next_page = resp->xdr.page_ptr + 1;
+
+	p = resp->tagp;
+	*p++ = htonl(resp->taglen);
+	memcpy(p, resp->tag, resp->taglen);
+	p += XDR_QUADLEN(resp->taglen);
+	*p++ = htonl(resp->opcnt);
+
+	nfsd4_sequence_done(resp);
+	return 1;
+}
+
+/*
+ * Local variables:
+ *  c-basic-offset: 8
+ * End:
+ */
diff --git a/fs/nfsd/nfscache.c b/fs/nfsd/nfscache.c
new file mode 100644
index 000000000..80c90fc23
--- /dev/null
+++ b/fs/nfsd/nfscache.c
@@ -0,0 +1,609 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Request reply cache. This is currently a global cache, but this may
+ * change in the future and be a per-client cache.
+ *
+ * This code is heavily inspired by the 44BSD implementation, although
+ * it does things a bit differently.
+ *
+ * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
+ */
+
+#include <linux/sunrpc/svc_xprt.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include <linux/sunrpc/addr.h>
+#include <linux/highmem.h>
+#include <linux/log2.h>
+#include <linux/hash.h>
+#include <net/checksum.h>
+
+#include "nfsd.h"
+#include "cache.h"
+#include "trace.h"
+
+/*
+ * We use this value to determine the number of hash buckets from the max
+ * cache size, the idea being that when the cache is at its maximum number
+ * of entries, then this should be the average number of entries per bucket.
+ */
+#define TARGET_BUCKET_SIZE	64
+
+struct nfsd_drc_bucket {
+	struct rb_root rb_head;
+	struct list_head lru_head;
+	spinlock_t cache_lock;
+};
+
+static struct kmem_cache	*drc_slab;
+
+static int	nfsd_cache_append(struct svc_rqst *rqstp, struct kvec *vec);
+static unsigned long nfsd_reply_cache_count(struct shrinker *shrink,
+					    struct shrink_control *sc);
+static unsigned long nfsd_reply_cache_scan(struct shrinker *shrink,
+					   struct shrink_control *sc);
+
+/*
+ * Put a cap on the size of the DRC based on the amount of available
+ * low memory in the machine.
+ *
+ *  64MB:    8192
+ * 128MB:   11585
+ * 256MB:   16384
+ * 512MB:   23170
+ *   1GB:   32768
+ *   2GB:   46340
+ *   4GB:   65536
+ *   8GB:   92681
+ *  16GB:  131072
+ *
+ * ...with a hard cap of 256k entries. In the worst case, each entry will be
+ * ~1k, so the above numbers should give a rough max of the amount of memory
+ * used in k.
+ *
+ * XXX: these limits are per-container, so memory used will increase
+ * linearly with number of containers.  Maybe that's OK.
+ */
+static unsigned int
+nfsd_cache_size_limit(void)
+{
+	unsigned int limit;
+	unsigned long low_pages = totalram_pages() - totalhigh_pages();
+
+	limit = (16 * int_sqrt(low_pages)) << (PAGE_SHIFT-10);
+	return min_t(unsigned int, limit, 256*1024);
+}
+
+/*
+ * Compute the number of hash buckets we need. Divide the max cachesize by
+ * the "target" max bucket size, and round up to next power of two.
+ */
+static unsigned int
+nfsd_hashsize(unsigned int limit)
+{
+	return roundup_pow_of_two(limit / TARGET_BUCKET_SIZE);
+}
+
+static u32
+nfsd_cache_hash(__be32 xid, struct nfsd_net *nn)
+{
+	return hash_32(be32_to_cpu(xid), nn->maskbits);
+}
+
+static struct svc_cacherep *
+nfsd_reply_cache_alloc(struct svc_rqst *rqstp, __wsum csum,
+			struct nfsd_net *nn)
+{
+	struct svc_cacherep	*rp;
+
+	rp = kmem_cache_alloc(drc_slab, GFP_KERNEL);
+	if (rp) {
+		rp->c_state = RC_UNUSED;
+		rp->c_type = RC_NOCACHE;
+		RB_CLEAR_NODE(&rp->c_node);
+		INIT_LIST_HEAD(&rp->c_lru);
+
+		memset(&rp->c_key, 0, sizeof(rp->c_key));
+		rp->c_key.k_xid = rqstp->rq_xid;
+		rp->c_key.k_proc = rqstp->rq_proc;
+		rpc_copy_addr((struct sockaddr *)&rp->c_key.k_addr, svc_addr(rqstp));
+		rpc_set_port((struct sockaddr *)&rp->c_key.k_addr, rpc_get_port(svc_addr(rqstp)));
+		rp->c_key.k_prot = rqstp->rq_prot;
+		rp->c_key.k_vers = rqstp->rq_vers;
+		rp->c_key.k_len = rqstp->rq_arg.len;
+		rp->c_key.k_csum = csum;
+	}
+	return rp;
+}
+
+static void
+nfsd_reply_cache_free_locked(struct nfsd_drc_bucket *b, struct svc_cacherep *rp,
+				struct nfsd_net *nn)
+{
+	if (rp->c_type == RC_REPLBUFF && rp->c_replvec.iov_base) {
+		nn->drc_mem_usage -= rp->c_replvec.iov_len;
+		kfree(rp->c_replvec.iov_base);
+	}
+	if (rp->c_state != RC_UNUSED) {
+		rb_erase(&rp->c_node, &b->rb_head);
+		list_del(&rp->c_lru);
+		atomic_dec(&nn->num_drc_entries);
+		nn->drc_mem_usage -= sizeof(*rp);
+	}
+	kmem_cache_free(drc_slab, rp);
+}
+
+static void
+nfsd_reply_cache_free(struct nfsd_drc_bucket *b, struct svc_cacherep *rp,
+			struct nfsd_net *nn)
+{
+	spin_lock(&b->cache_lock);
+	nfsd_reply_cache_free_locked(b, rp, nn);
+	spin_unlock(&b->cache_lock);
+}
+
+int nfsd_drc_slab_create(void)
+{
+	drc_slab = kmem_cache_create("nfsd_drc",
+				sizeof(struct svc_cacherep), 0, 0, NULL);
+	return drc_slab ? 0: -ENOMEM;
+}
+
+void nfsd_drc_slab_free(void)
+{
+	kmem_cache_destroy(drc_slab);
+}
+
+int nfsd_reply_cache_init(struct nfsd_net *nn)
+{
+	unsigned int hashsize;
+	unsigned int i;
+	int status = 0;
+
+	nn->max_drc_entries = nfsd_cache_size_limit();
+	atomic_set(&nn->num_drc_entries, 0);
+	hashsize = nfsd_hashsize(nn->max_drc_entries);
+	nn->maskbits = ilog2(hashsize);
+
+	nn->nfsd_reply_cache_shrinker.scan_objects = nfsd_reply_cache_scan;
+	nn->nfsd_reply_cache_shrinker.count_objects = nfsd_reply_cache_count;
+	nn->nfsd_reply_cache_shrinker.seeks = 1;
+	status = register_shrinker(&nn->nfsd_reply_cache_shrinker);
+	if (status)
+		goto out_nomem;
+
+	nn->drc_hashtbl = kvzalloc(array_size(hashsize,
+				sizeof(*nn->drc_hashtbl)), GFP_KERNEL);
+	if (!nn->drc_hashtbl)
+		goto out_shrinker;
+
+	for (i = 0; i < hashsize; i++) {
+		INIT_LIST_HEAD(&nn->drc_hashtbl[i].lru_head);
+		spin_lock_init(&nn->drc_hashtbl[i].cache_lock);
+	}
+	nn->drc_hashsize = hashsize;
+
+	return 0;
+out_shrinker:
+	unregister_shrinker(&nn->nfsd_reply_cache_shrinker);
+out_nomem:
+	printk(KERN_ERR "nfsd: failed to allocate reply cache\n");
+	return -ENOMEM;
+}
+
+void nfsd_reply_cache_shutdown(struct nfsd_net *nn)
+{
+	struct svc_cacherep	*rp;
+	unsigned int i;
+
+	unregister_shrinker(&nn->nfsd_reply_cache_shrinker);
+
+	for (i = 0; i < nn->drc_hashsize; i++) {
+		struct list_head *head = &nn->drc_hashtbl[i].lru_head;
+		while (!list_empty(head)) {
+			rp = list_first_entry(head, struct svc_cacherep, c_lru);
+			nfsd_reply_cache_free_locked(&nn->drc_hashtbl[i],
+									rp, nn);
+		}
+	}
+
+	kvfree(nn->drc_hashtbl);
+	nn->drc_hashtbl = NULL;
+	nn->drc_hashsize = 0;
+
+}
+
+/*
+ * Move cache entry to end of LRU list, and queue the cleaner to run if it's
+ * not already scheduled.
+ */
+static void
+lru_put_end(struct nfsd_drc_bucket *b, struct svc_cacherep *rp)
+{
+	rp->c_timestamp = jiffies;
+	list_move_tail(&rp->c_lru, &b->lru_head);
+}
+
+static long
+prune_bucket(struct nfsd_drc_bucket *b, struct nfsd_net *nn)
+{
+	struct svc_cacherep *rp, *tmp;
+	long freed = 0;
+
+	list_for_each_entry_safe(rp, tmp, &b->lru_head, c_lru) {
+		/*
+		 * Don't free entries attached to calls that are still
+		 * in-progress, but do keep scanning the list.
+		 */
+		if (rp->c_state == RC_INPROG)
+			continue;
+		if (atomic_read(&nn->num_drc_entries) <= nn->max_drc_entries &&
+		    time_before(jiffies, rp->c_timestamp + RC_EXPIRE))
+			break;
+		nfsd_reply_cache_free_locked(b, rp, nn);
+		freed++;
+	}
+	return freed;
+}
+
+/*
+ * Walk the LRU list and prune off entries that are older than RC_EXPIRE.
+ * Also prune the oldest ones when the total exceeds the max number of entries.
+ */
+static long
+prune_cache_entries(struct nfsd_net *nn)
+{
+	unsigned int i;
+	long freed = 0;
+
+	for (i = 0; i < nn->drc_hashsize; i++) {
+		struct nfsd_drc_bucket *b = &nn->drc_hashtbl[i];
+
+		if (list_empty(&b->lru_head))
+			continue;
+		spin_lock(&b->cache_lock);
+		freed += prune_bucket(b, nn);
+		spin_unlock(&b->cache_lock);
+	}
+	return freed;
+}
+
+static unsigned long
+nfsd_reply_cache_count(struct shrinker *shrink, struct shrink_control *sc)
+{
+	struct nfsd_net *nn = container_of(shrink,
+				struct nfsd_net, nfsd_reply_cache_shrinker);
+
+	return atomic_read(&nn->num_drc_entries);
+}
+
+static unsigned long
+nfsd_reply_cache_scan(struct shrinker *shrink, struct shrink_control *sc)
+{
+	struct nfsd_net *nn = container_of(shrink,
+				struct nfsd_net, nfsd_reply_cache_shrinker);
+
+	return prune_cache_entries(nn);
+}
+/*
+ * Walk an xdr_buf and get a CRC for at most the first RC_CSUMLEN bytes
+ */
+static __wsum
+nfsd_cache_csum(struct svc_rqst *rqstp)
+{
+	int idx;
+	unsigned int base;
+	__wsum csum;
+	struct xdr_buf *buf = &rqstp->rq_arg;
+	const unsigned char *p = buf->head[0].iov_base;
+	size_t csum_len = min_t(size_t, buf->head[0].iov_len + buf->page_len,
+				RC_CSUMLEN);
+	size_t len = min(buf->head[0].iov_len, csum_len);
+
+	/* rq_arg.head first */
+	csum = csum_partial(p, len, 0);
+	csum_len -= len;
+
+	/* Continue into page array */
+	idx = buf->page_base / PAGE_SIZE;
+	base = buf->page_base & ~PAGE_MASK;
+	while (csum_len) {
+		p = page_address(buf->pages[idx]) + base;
+		len = min_t(size_t, PAGE_SIZE - base, csum_len);
+		csum = csum_partial(p, len, csum);
+		csum_len -= len;
+		base = 0;
+		++idx;
+	}
+	return csum;
+}
+
+static int
+nfsd_cache_key_cmp(const struct svc_cacherep *key,
+			const struct svc_cacherep *rp, struct nfsd_net *nn)
+{
+	if (key->c_key.k_xid == rp->c_key.k_xid &&
+	    key->c_key.k_csum != rp->c_key.k_csum) {
+		++nn->payload_misses;
+		trace_nfsd_drc_mismatch(nn, key, rp);
+	}
+
+	return memcmp(&key->c_key, &rp->c_key, sizeof(key->c_key));
+}
+
+/*
+ * Search the request hash for an entry that matches the given rqstp.
+ * Must be called with cache_lock held. Returns the found entry or
+ * inserts an empty key on failure.
+ */
+static struct svc_cacherep *
+nfsd_cache_insert(struct nfsd_drc_bucket *b, struct svc_cacherep *key,
+			struct nfsd_net *nn)
+{
+	struct svc_cacherep	*rp, *ret = key;
+	struct rb_node		**p = &b->rb_head.rb_node,
+				*parent = NULL;
+	unsigned int		entries = 0;
+	int cmp;
+
+	while (*p != NULL) {
+		++entries;
+		parent = *p;
+		rp = rb_entry(parent, struct svc_cacherep, c_node);
+
+		cmp = nfsd_cache_key_cmp(key, rp, nn);
+		if (cmp < 0)
+			p = &parent->rb_left;
+		else if (cmp > 0)
+			p = &parent->rb_right;
+		else {
+			ret = rp;
+			goto out;
+		}
+	}
+	rb_link_node(&key->c_node, parent, p);
+	rb_insert_color(&key->c_node, &b->rb_head);
+out:
+	/* tally hash chain length stats */
+	if (entries > nn->longest_chain) {
+		nn->longest_chain = entries;
+		nn->longest_chain_cachesize = atomic_read(&nn->num_drc_entries);
+	} else if (entries == nn->longest_chain) {
+		/* prefer to keep the smallest cachesize possible here */
+		nn->longest_chain_cachesize = min_t(unsigned int,
+				nn->longest_chain_cachesize,
+				atomic_read(&nn->num_drc_entries));
+	}
+
+	lru_put_end(b, ret);
+	return ret;
+}
+
+/**
+ * nfsd_cache_lookup - Find an entry in the duplicate reply cache
+ * @rqstp: Incoming Call to find
+ *
+ * Try to find an entry matching the current call in the cache. When none
+ * is found, we try to grab the oldest expired entry off the LRU list. If
+ * a suitable one isn't there, then drop the cache_lock and allocate a
+ * new one, then search again in case one got inserted while this thread
+ * didn't hold the lock.
+ *
+ * Return values:
+ *   %RC_DOIT: Process the request normally
+ *   %RC_REPLY: Reply from cache
+ *   %RC_DROPIT: Do not process the request further
+ */
+int nfsd_cache_lookup(struct svc_rqst *rqstp)
+{
+	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+	struct svc_cacherep	*rp, *found;
+	__be32			xid = rqstp->rq_xid;
+	__wsum			csum;
+	u32 hash = nfsd_cache_hash(xid, nn);
+	struct nfsd_drc_bucket *b = &nn->drc_hashtbl[hash];
+	int type = rqstp->rq_cachetype;
+	int rtn = RC_DOIT;
+
+	rqstp->rq_cacherep = NULL;
+	if (type == RC_NOCACHE) {
+		nfsdstats.rcnocache++;
+		goto out;
+	}
+
+	csum = nfsd_cache_csum(rqstp);
+
+	/*
+	 * Since the common case is a cache miss followed by an insert,
+	 * preallocate an entry.
+	 */
+	rp = nfsd_reply_cache_alloc(rqstp, csum, nn);
+	if (!rp)
+		goto out;
+
+	spin_lock(&b->cache_lock);
+	found = nfsd_cache_insert(b, rp, nn);
+	if (found != rp) {
+		nfsd_reply_cache_free_locked(NULL, rp, nn);
+		rp = found;
+		goto found_entry;
+	}
+
+	nfsdstats.rcmisses++;
+	rqstp->rq_cacherep = rp;
+	rp->c_state = RC_INPROG;
+
+	atomic_inc(&nn->num_drc_entries);
+	nn->drc_mem_usage += sizeof(*rp);
+
+	/* go ahead and prune the cache */
+	prune_bucket(b, nn);
+
+out_unlock:
+	spin_unlock(&b->cache_lock);
+out:
+	return rtn;
+
+found_entry:
+	/* We found a matching entry which is either in progress or done. */
+	nfsdstats.rchits++;
+	rtn = RC_DROPIT;
+
+	/* Request being processed */
+	if (rp->c_state == RC_INPROG)
+		goto out_trace;
+
+	/* From the hall of fame of impractical attacks:
+	 * Is this a user who tries to snoop on the cache? */
+	rtn = RC_DOIT;
+	if (!test_bit(RQ_SECURE, &rqstp->rq_flags) && rp->c_secure)
+		goto out_trace;
+
+	/* Compose RPC reply header */
+	switch (rp->c_type) {
+	case RC_NOCACHE:
+		break;
+	case RC_REPLSTAT:
+		svc_putu32(&rqstp->rq_res.head[0], rp->c_replstat);
+		rtn = RC_REPLY;
+		break;
+	case RC_REPLBUFF:
+		if (!nfsd_cache_append(rqstp, &rp->c_replvec))
+			goto out_unlock; /* should not happen */
+		rtn = RC_REPLY;
+		break;
+	default:
+		WARN_ONCE(1, "nfsd: bad repcache type %d\n", rp->c_type);
+	}
+
+out_trace:
+	trace_nfsd_drc_found(nn, rqstp, rtn);
+	goto out_unlock;
+}
+
+/**
+ * nfsd_cache_update - Update an entry in the duplicate reply cache.
+ * @rqstp: svc_rqst with a finished Reply
+ * @cachetype: which cache to update
+ * @statp: Reply's status code
+ *
+ * This is called from nfsd_dispatch when the procedure has been
+ * executed and the complete reply is in rqstp->rq_res.
+ *
+ * We're copying around data here rather than swapping buffers because
+ * the toplevel loop requires max-sized buffers, which would be a waste
+ * of memory for a cache with a max reply size of 100 bytes (diropokres).
+ *
+ * If we should start to use different types of cache entries tailored
+ * specifically for attrstat and fh's, we may save even more space.
+ *
+ * Also note that a cachetype of RC_NOCACHE can legally be passed when
+ * nfsd failed to encode a reply that otherwise would have been cached.
+ * In this case, nfsd_cache_update is called with statp == NULL.
+ */
+void nfsd_cache_update(struct svc_rqst *rqstp, int cachetype, __be32 *statp)
+{
+	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+	struct svc_cacherep *rp = rqstp->rq_cacherep;
+	struct kvec	*resv = &rqstp->rq_res.head[0], *cachv;
+	u32		hash;
+	struct nfsd_drc_bucket *b;
+	int		len;
+	size_t		bufsize = 0;
+
+	if (!rp)
+		return;
+
+	hash = nfsd_cache_hash(rp->c_key.k_xid, nn);
+	b = &nn->drc_hashtbl[hash];
+
+	len = resv->iov_len - ((char*)statp - (char*)resv->iov_base);
+	len >>= 2;
+
+	/* Don't cache excessive amounts of data and XDR failures */
+	if (!statp || len > (256 >> 2)) {
+		nfsd_reply_cache_free(b, rp, nn);
+		return;
+	}
+
+	switch (cachetype) {
+	case RC_REPLSTAT:
+		if (len != 1)
+			printk("nfsd: RC_REPLSTAT/reply len %d!\n",len);
+		rp->c_replstat = *statp;
+		break;
+	case RC_REPLBUFF:
+		cachv = &rp->c_replvec;
+		bufsize = len << 2;
+		cachv->iov_base = kmalloc(bufsize, GFP_KERNEL);
+		if (!cachv->iov_base) {
+			nfsd_reply_cache_free(b, rp, nn);
+			return;
+		}
+		cachv->iov_len = bufsize;
+		memcpy(cachv->iov_base, statp, bufsize);
+		break;
+	case RC_NOCACHE:
+		nfsd_reply_cache_free(b, rp, nn);
+		return;
+	}
+	spin_lock(&b->cache_lock);
+	nn->drc_mem_usage += bufsize;
+	lru_put_end(b, rp);
+	rp->c_secure = test_bit(RQ_SECURE, &rqstp->rq_flags);
+	rp->c_type = cachetype;
+	rp->c_state = RC_DONE;
+	spin_unlock(&b->cache_lock);
+	return;
+}
+
+/*
+ * Copy cached reply to current reply buffer. Should always fit.
+ * FIXME as reply is in a page, we should just attach the page, and
+ * keep a refcount....
+ */
+static int
+nfsd_cache_append(struct svc_rqst *rqstp, struct kvec *data)
+{
+	struct kvec	*vec = &rqstp->rq_res.head[0];
+
+	if (vec->iov_len + data->iov_len > PAGE_SIZE) {
+		printk(KERN_WARNING "nfsd: cached reply too large (%zd).\n",
+				data->iov_len);
+		return 0;
+	}
+	memcpy((char*)vec->iov_base + vec->iov_len, data->iov_base, data->iov_len);
+	vec->iov_len += data->iov_len;
+	return 1;
+}
+
+/*
+ * Note that fields may be added, removed or reordered in the future. Programs
+ * scraping this file for info should test the labels to ensure they're
+ * getting the correct field.
+ */
+static int nfsd_reply_cache_stats_show(struct seq_file *m, void *v)
+{
+	struct nfsd_net *nn = m->private;
+
+	seq_printf(m, "max entries:           %u\n", nn->max_drc_entries);
+	seq_printf(m, "num entries:           %u\n",
+			atomic_read(&nn->num_drc_entries));
+	seq_printf(m, "hash buckets:          %u\n", 1 << nn->maskbits);
+	seq_printf(m, "mem usage:             %u\n", nn->drc_mem_usage);
+	seq_printf(m, "cache hits:            %u\n", nfsdstats.rchits);
+	seq_printf(m, "cache misses:          %u\n", nfsdstats.rcmisses);
+	seq_printf(m, "not cached:            %u\n", nfsdstats.rcnocache);
+	seq_printf(m, "payload misses:        %u\n", nn->payload_misses);
+	seq_printf(m, "longest chain len:     %u\n", nn->longest_chain);
+	seq_printf(m, "cachesize at longest:  %u\n", nn->longest_chain_cachesize);
+	return 0;
+}
+
+int nfsd_reply_cache_stats_open(struct inode *inode, struct file *file)
+{
+	struct nfsd_net *nn = net_generic(file_inode(file)->i_sb->s_fs_info,
+								nfsd_net_id);
+
+	return single_open(file, nfsd_reply_cache_stats_show, nn);
+}
diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
new file mode 100644
index 000000000..c4b11560a
--- /dev/null
+++ b/fs/nfsd/nfsctl.c
@@ -0,0 +1,1578 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Syscall interface to knfsd.
+ *
+ * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
+ */
+
+#include <linux/slab.h>
+#include <linux/namei.h>
+#include <linux/ctype.h>
+#include <linux/fs_context.h>
+
+#include <linux/sunrpc/svcsock.h>
+#include <linux/lockd/lockd.h>
+#include <linux/sunrpc/addr.h>
+#include <linux/sunrpc/gss_api.h>
+#include <linux/sunrpc/gss_krb5_enctypes.h>
+#include <linux/sunrpc/rpc_pipe_fs.h>
+#include <linux/module.h>
+#include <linux/fsnotify.h>
+
+#include "idmap.h"
+#include "nfsd.h"
+#include "cache.h"
+#include "state.h"
+#include "netns.h"
+#include "pnfs.h"
+
+/*
+ *	We have a single directory with several nodes in it.
+ */
+enum {
+	NFSD_Root = 1,
+	NFSD_List,
+	NFSD_Export_features,
+	NFSD_Fh,
+	NFSD_FO_UnlockIP,
+	NFSD_FO_UnlockFS,
+	NFSD_Threads,
+	NFSD_Pool_Threads,
+	NFSD_Pool_Stats,
+	NFSD_Reply_Cache_Stats,
+	NFSD_Versions,
+	NFSD_Ports,
+	NFSD_MaxBlkSize,
+	NFSD_MaxConnections,
+	NFSD_SupportedEnctypes,
+	/*
+	 * The below MUST come last.  Otherwise we leave a hole in nfsd_files[]
+	 * with !CONFIG_NFSD_V4 and simple_fill_super() goes oops
+	 */
+#ifdef CONFIG_NFSD_V4
+	NFSD_Leasetime,
+	NFSD_Gracetime,
+	NFSD_RecoveryDir,
+	NFSD_V4EndGrace,
+#endif
+	NFSD_MaxReserved
+};
+
+/*
+ * write() for these nodes.
+ */
+static ssize_t write_filehandle(struct file *file, char *buf, size_t size);
+static ssize_t write_unlock_ip(struct file *file, char *buf, size_t size);
+static ssize_t write_unlock_fs(struct file *file, char *buf, size_t size);
+static ssize_t write_threads(struct file *file, char *buf, size_t size);
+static ssize_t write_pool_threads(struct file *file, char *buf, size_t size);
+static ssize_t write_versions(struct file *file, char *buf, size_t size);
+static ssize_t write_ports(struct file *file, char *buf, size_t size);
+static ssize_t write_maxblksize(struct file *file, char *buf, size_t size);
+static ssize_t write_maxconn(struct file *file, char *buf, size_t size);
+#ifdef CONFIG_NFSD_V4
+static ssize_t write_leasetime(struct file *file, char *buf, size_t size);
+static ssize_t write_gracetime(struct file *file, char *buf, size_t size);
+static ssize_t write_recoverydir(struct file *file, char *buf, size_t size);
+static ssize_t write_v4_end_grace(struct file *file, char *buf, size_t size);
+#endif
+
+static ssize_t (*const write_op[])(struct file *, char *, size_t) = {
+	[NFSD_Fh] = write_filehandle,
+	[NFSD_FO_UnlockIP] = write_unlock_ip,
+	[NFSD_FO_UnlockFS] = write_unlock_fs,
+	[NFSD_Threads] = write_threads,
+	[NFSD_Pool_Threads] = write_pool_threads,
+	[NFSD_Versions] = write_versions,
+	[NFSD_Ports] = write_ports,
+	[NFSD_MaxBlkSize] = write_maxblksize,
+	[NFSD_MaxConnections] = write_maxconn,
+#ifdef CONFIG_NFSD_V4
+	[NFSD_Leasetime] = write_leasetime,
+	[NFSD_Gracetime] = write_gracetime,
+	[NFSD_RecoveryDir] = write_recoverydir,
+	[NFSD_V4EndGrace] = write_v4_end_grace,
+#endif
+};
+
+static ssize_t nfsctl_transaction_write(struct file *file, const char __user *buf, size_t size, loff_t *pos)
+{
+	ino_t ino =  file_inode(file)->i_ino;
+	char *data;
+	ssize_t rv;
+
+	if (ino >= ARRAY_SIZE(write_op) || !write_op[ino])
+		return -EINVAL;
+
+	data = simple_transaction_get(file, buf, size);
+	if (IS_ERR(data))
+		return PTR_ERR(data);
+
+	rv =  write_op[ino](file, data, size);
+	if (rv >= 0) {
+		simple_transaction_set(file, rv);
+		rv = size;
+	}
+	return rv;
+}
+
+static ssize_t nfsctl_transaction_read(struct file *file, char __user *buf, size_t size, loff_t *pos)
+{
+	if (! file->private_data) {
+		/* An attempt to read a transaction file without writing
+		 * causes a 0-byte write so that the file can return
+		 * state information
+		 */
+		ssize_t rv = nfsctl_transaction_write(file, buf, 0, pos);
+		if (rv < 0)
+			return rv;
+	}
+	return simple_transaction_read(file, buf, size, pos);
+}
+
+static const struct file_operations transaction_ops = {
+	.write		= nfsctl_transaction_write,
+	.read		= nfsctl_transaction_read,
+	.release	= simple_transaction_release,
+	.llseek		= default_llseek,
+};
+
+static int exports_net_open(struct net *net, struct file *file)
+{
+	int err;
+	struct seq_file *seq;
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	err = seq_open(file, &nfs_exports_op);
+	if (err)
+		return err;
+
+	seq = file->private_data;
+	seq->private = nn->svc_export_cache;
+	return 0;
+}
+
+static int exports_proc_open(struct inode *inode, struct file *file)
+{
+	return exports_net_open(current->nsproxy->net_ns, file);
+}
+
+static const struct proc_ops exports_proc_ops = {
+	.proc_open	= exports_proc_open,
+	.proc_read	= seq_read,
+	.proc_lseek	= seq_lseek,
+	.proc_release	= seq_release,
+};
+
+static int exports_nfsd_open(struct inode *inode, struct file *file)
+{
+	return exports_net_open(inode->i_sb->s_fs_info, file);
+}
+
+static const struct file_operations exports_nfsd_operations = {
+	.open		= exports_nfsd_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= seq_release,
+};
+
+static int export_features_show(struct seq_file *m, void *v)
+{
+	seq_printf(m, "0x%x 0x%x\n", NFSEXP_ALLFLAGS, NFSEXP_SECINFO_FLAGS);
+	return 0;
+}
+
+static int export_features_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, export_features_show, NULL);
+}
+
+static const struct file_operations export_features_operations = {
+	.open		= export_features_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+
+#if defined(CONFIG_SUNRPC_GSS) || defined(CONFIG_SUNRPC_GSS_MODULE)
+static int supported_enctypes_show(struct seq_file *m, void *v)
+{
+	seq_printf(m, KRB5_SUPPORTED_ENCTYPES);
+	return 0;
+}
+
+static int supported_enctypes_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, supported_enctypes_show, NULL);
+}
+
+static const struct file_operations supported_enctypes_ops = {
+	.open		= supported_enctypes_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+#endif /* CONFIG_SUNRPC_GSS or CONFIG_SUNRPC_GSS_MODULE */
+
+static const struct file_operations pool_stats_operations = {
+	.open		= nfsd_pool_stats_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= nfsd_pool_stats_release,
+};
+
+static const struct file_operations reply_cache_stats_operations = {
+	.open		= nfsd_reply_cache_stats_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+
+/*----------------------------------------------------------------------------*/
+/*
+ * payload - write methods
+ */
+
+static inline struct net *netns(struct file *file)
+{
+	return file_inode(file)->i_sb->s_fs_info;
+}
+
+/*
+ * write_unlock_ip - Release all locks used by a client
+ *
+ * Experimental.
+ *
+ * Input:
+ *			buf:	'\n'-terminated C string containing a
+ *				presentation format IP address
+ *			size:	length of C string in @buf
+ * Output:
+ *	On success:	returns zero if all specified locks were released;
+ *			returns one if one or more locks were not released
+ *	On error:	return code is negative errno value
+ */
+static ssize_t write_unlock_ip(struct file *file, char *buf, size_t size)
+{
+	struct sockaddr_storage address;
+	struct sockaddr *sap = (struct sockaddr *)&address;
+	size_t salen = sizeof(address);
+	char *fo_path;
+	struct net *net = netns(file);
+
+	/* sanity check */
+	if (size == 0)
+		return -EINVAL;
+
+	if (buf[size-1] != '\n')
+		return -EINVAL;
+
+	fo_path = buf;
+	if (qword_get(&buf, fo_path, size) < 0)
+		return -EINVAL;
+
+	if (rpc_pton(net, fo_path, size, sap, salen) == 0)
+		return -EINVAL;
+
+	return nlmsvc_unlock_all_by_ip(sap);
+}
+
+/*
+ * write_unlock_fs - Release all locks on a local file system
+ *
+ * Experimental.
+ *
+ * Input:
+ *			buf:	'\n'-terminated C string containing the
+ *				absolute pathname of a local file system
+ *			size:	length of C string in @buf
+ * Output:
+ *	On success:	returns zero if all specified locks were released;
+ *			returns one if one or more locks were not released
+ *	On error:	return code is negative errno value
+ */
+static ssize_t write_unlock_fs(struct file *file, char *buf, size_t size)
+{
+	struct path path;
+	char *fo_path;
+	int error;
+
+	/* sanity check */
+	if (size == 0)
+		return -EINVAL;
+
+	if (buf[size-1] != '\n')
+		return -EINVAL;
+
+	fo_path = buf;
+	if (qword_get(&buf, fo_path, size) < 0)
+		return -EINVAL;
+
+	error = kern_path(fo_path, 0, &path);
+	if (error)
+		return error;
+
+	/*
+	 * XXX: Needs better sanity checking.  Otherwise we could end up
+	 * releasing locks on the wrong file system.
+	 *
+	 * For example:
+	 * 1.  Does the path refer to a directory?
+	 * 2.  Is that directory a mount point, or
+	 * 3.  Is that directory the root of an exported file system?
+	 */
+	error = nlmsvc_unlock_all_by_sb(path.dentry->d_sb);
+
+	path_put(&path);
+	return error;
+}
+
+/*
+ * write_filehandle - Get a variable-length NFS file handle by path
+ *
+ * On input, the buffer contains a '\n'-terminated C string comprised of
+ * three alphanumeric words separated by whitespace.  The string may
+ * contain escape sequences.
+ *
+ * Input:
+ *			buf:
+ *				domain:		client domain name
+ *				path:		export pathname
+ *				maxsize:	numeric maximum size of
+ *						@buf
+ *			size:	length of C string in @buf
+ * Output:
+ *	On success:	passed-in buffer filled with '\n'-terminated C
+ *			string containing a ASCII hex text version
+ *			of the NFS file handle;
+ *			return code is the size in bytes of the string
+ *	On error:	return code is negative errno value
+ */
+static ssize_t write_filehandle(struct file *file, char *buf, size_t size)
+{
+	char *dname, *path;
+	int maxsize;
+	char *mesg = buf;
+	int len;
+	struct auth_domain *dom;
+	struct knfsd_fh fh;
+
+	if (size == 0)
+		return -EINVAL;
+
+	if (buf[size-1] != '\n')
+		return -EINVAL;
+	buf[size-1] = 0;
+
+	dname = mesg;
+	len = qword_get(&mesg, dname, size);
+	if (len <= 0)
+		return -EINVAL;
+	
+	path = dname+len+1;
+	len = qword_get(&mesg, path, size);
+	if (len <= 0)
+		return -EINVAL;
+
+	len = get_int(&mesg, &maxsize);
+	if (len)
+		return len;
+
+	if (maxsize < NFS_FHSIZE)
+		return -EINVAL;
+	maxsize = min(maxsize, NFS3_FHSIZE);
+
+	if (qword_get(&mesg, mesg, size)>0)
+		return -EINVAL;
+
+	/* we have all the words, they are in buf.. */
+	dom = unix_domain_find(dname);
+	if (!dom)
+		return -ENOMEM;
+
+	len = exp_rootfh(netns(file), dom, path, &fh,  maxsize);
+	auth_domain_put(dom);
+	if (len)
+		return len;
+	
+	mesg = buf;
+	len = SIMPLE_TRANSACTION_LIMIT;
+	qword_addhex(&mesg, &len, (char*)&fh.fh_base, fh.fh_size);
+	mesg[-1] = '\n';
+	return mesg - buf;	
+}
+
+/*
+ * write_threads - Start NFSD, or report the current number of running threads
+ *
+ * Input:
+ *			buf:		ignored
+ *			size:		zero
+ * Output:
+ *	On success:	passed-in buffer filled with '\n'-terminated C
+ *			string numeric value representing the number of
+ *			running NFSD threads;
+ *			return code is the size in bytes of the string
+ *	On error:	return code is zero
+ *
+ * OR
+ *
+ * Input:
+ *			buf:		C string containing an unsigned
+ *					integer value representing the
+ *					number of NFSD threads to start
+ *			size:		non-zero length of C string in @buf
+ * Output:
+ *	On success:	NFS service is started;
+ *			passed-in buffer filled with '\n'-terminated C
+ *			string numeric value representing the number of
+ *			running NFSD threads;
+ *			return code is the size in bytes of the string
+ *	On error:	return code is zero or a negative errno value
+ */
+static ssize_t write_threads(struct file *file, char *buf, size_t size)
+{
+	char *mesg = buf;
+	int rv;
+	struct net *net = netns(file);
+
+	if (size > 0) {
+		int newthreads;
+		rv = get_int(&mesg, &newthreads);
+		if (rv)
+			return rv;
+		if (newthreads < 0)
+			return -EINVAL;
+		rv = nfsd_svc(newthreads, net, file->f_cred);
+		if (rv < 0)
+			return rv;
+	} else
+		rv = nfsd_nrthreads(net);
+
+	return scnprintf(buf, SIMPLE_TRANSACTION_LIMIT, "%d\n", rv);
+}
+
+/*
+ * write_pool_threads - Set or report the current number of threads per pool
+ *
+ * Input:
+ *			buf:		ignored
+ *			size:		zero
+ *
+ * OR
+ *
+ * Input:
+ * 			buf:		C string containing whitespace-
+ * 					separated unsigned integer values
+ *					representing the number of NFSD
+ *					threads to start in each pool
+ *			size:		non-zero length of C string in @buf
+ * Output:
+ *	On success:	passed-in buffer filled with '\n'-terminated C
+ *			string containing integer values representing the
+ *			number of NFSD threads in each pool;
+ *			return code is the size in bytes of the string
+ *	On error:	return code is zero or a negative errno value
+ */
+static ssize_t write_pool_threads(struct file *file, char *buf, size_t size)
+{
+	/* if size > 0, look for an array of number of threads per node
+	 * and apply them  then write out number of threads per node as reply
+	 */
+	char *mesg = buf;
+	int i;
+	int rv;
+	int len;
+	int npools;
+	int *nthreads;
+	struct net *net = netns(file);
+
+	mutex_lock(&nfsd_mutex);
+	npools = nfsd_nrpools(net);
+	if (npools == 0) {
+		/*
+		 * NFS is shut down.  The admin can start it by
+		 * writing to the threads file but NOT the pool_threads
+		 * file, sorry.  Report zero threads.
+		 */
+		mutex_unlock(&nfsd_mutex);
+		strcpy(buf, "0\n");
+		return strlen(buf);
+	}
+
+	nthreads = kcalloc(npools, sizeof(int), GFP_KERNEL);
+	rv = -ENOMEM;
+	if (nthreads == NULL)
+		goto out_free;
+
+	if (size > 0) {
+		for (i = 0; i < npools; i++) {
+			rv = get_int(&mesg, &nthreads[i]);
+			if (rv == -ENOENT)
+				break;		/* fewer numbers than pools */
+			if (rv)
+				goto out_free;	/* syntax error */
+			rv = -EINVAL;
+			if (nthreads[i] < 0)
+				goto out_free;
+		}
+		rv = nfsd_set_nrthreads(i, nthreads, net);
+		if (rv)
+			goto out_free;
+	}
+
+	rv = nfsd_get_nrthreads(npools, nthreads, net);
+	if (rv)
+		goto out_free;
+
+	mesg = buf;
+	size = SIMPLE_TRANSACTION_LIMIT;
+	for (i = 0; i < npools && size > 0; i++) {
+		snprintf(mesg, size, "%d%c", nthreads[i], (i == npools-1 ? '\n' : ' '));
+		len = strlen(mesg);
+		size -= len;
+		mesg += len;
+	}
+	rv = mesg - buf;
+out_free:
+	kfree(nthreads);
+	mutex_unlock(&nfsd_mutex);
+	return rv;
+}
+
+static ssize_t
+nfsd_print_version_support(struct nfsd_net *nn, char *buf, int remaining,
+		const char *sep, unsigned vers, int minor)
+{
+	const char *format = minor < 0 ? "%s%c%u" : "%s%c%u.%u";
+	bool supported = !!nfsd_vers(nn, vers, NFSD_TEST);
+
+	if (vers == 4 && minor >= 0 &&
+	    !nfsd_minorversion(nn, minor, NFSD_TEST))
+		supported = false;
+	if (minor == 0 && supported)
+		/*
+		 * special case for backward compatability.
+		 * +4.0 is never reported, it is implied by
+		 * +4, unless -4.0 is present.
+		 */
+		return 0;
+	return snprintf(buf, remaining, format, sep,
+			supported ? '+' : '-', vers, minor);
+}
+
+static ssize_t __write_versions(struct file *file, char *buf, size_t size)
+{
+	char *mesg = buf;
+	char *vers, *minorp, sign;
+	int len, num, remaining;
+	ssize_t tlen = 0;
+	char *sep;
+	struct nfsd_net *nn = net_generic(netns(file), nfsd_net_id);
+
+	if (size>0) {
+		if (nn->nfsd_serv)
+			/* Cannot change versions without updating
+			 * nn->nfsd_serv->sv_xdrsize, and reallocing
+			 * rq_argp and rq_resp
+			 */
+			return -EBUSY;
+		if (buf[size-1] != '\n')
+			return -EINVAL;
+		buf[size-1] = 0;
+
+		vers = mesg;
+		len = qword_get(&mesg, vers, size);
+		if (len <= 0) return -EINVAL;
+		do {
+			enum vers_op cmd;
+			unsigned minor;
+			sign = *vers;
+			if (sign == '+' || sign == '-')
+				num = simple_strtol((vers+1), &minorp, 0);
+			else
+				num = simple_strtol(vers, &minorp, 0);
+			if (*minorp == '.') {
+				if (num != 4)
+					return -EINVAL;
+				if (kstrtouint(minorp+1, 0, &minor) < 0)
+					return -EINVAL;
+			}
+
+			cmd = sign == '-' ? NFSD_CLEAR : NFSD_SET;
+			switch(num) {
+			case 2:
+			case 3:
+				nfsd_vers(nn, num, cmd);
+				break;
+			case 4:
+				if (*minorp == '.') {
+					if (nfsd_minorversion(nn, minor, cmd) < 0)
+						return -EINVAL;
+				} else if ((cmd == NFSD_SET) != nfsd_vers(nn, num, NFSD_TEST)) {
+					/*
+					 * Either we have +4 and no minors are enabled,
+					 * or we have -4 and at least one minor is enabled.
+					 * In either case, propagate 'cmd' to all minors.
+					 */
+					minor = 0;
+					while (nfsd_minorversion(nn, minor, cmd) >= 0)
+						minor++;
+				}
+				break;
+			default:
+				return -EINVAL;
+			}
+			vers += len + 1;
+		} while ((len = qword_get(&mesg, vers, size)) > 0);
+		/* If all get turned off, turn them back on, as
+		 * having no versions is BAD
+		 */
+		nfsd_reset_versions(nn);
+	}
+
+	/* Now write current state into reply buffer */
+	len = 0;
+	sep = "";
+	remaining = SIMPLE_TRANSACTION_LIMIT;
+	for (num=2 ; num <= 4 ; num++) {
+		int minor;
+		if (!nfsd_vers(nn, num, NFSD_AVAIL))
+			continue;
+
+		minor = -1;
+		do {
+			len = nfsd_print_version_support(nn, buf, remaining,
+					sep, num, minor);
+			if (len >= remaining)
+				goto out;
+			remaining -= len;
+			buf += len;
+			tlen += len;
+			minor++;
+			if (len)
+				sep = " ";
+		} while (num == 4 && minor <= NFSD_SUPPORTED_MINOR_VERSION);
+	}
+out:
+	len = snprintf(buf, remaining, "\n");
+	if (len >= remaining)
+		return -EINVAL;
+	return tlen + len;
+}
+
+/*
+ * write_versions - Set or report the available NFS protocol versions
+ *
+ * Input:
+ *			buf:		ignored
+ *			size:		zero
+ * Output:
+ *	On success:	passed-in buffer filled with '\n'-terminated C
+ *			string containing positive or negative integer
+ *			values representing the current status of each
+ *			protocol version;
+ *			return code is the size in bytes of the string
+ *	On error:	return code is zero or a negative errno value
+ *
+ * OR
+ *
+ * Input:
+ * 			buf:		C string containing whitespace-
+ * 					separated positive or negative
+ * 					integer values representing NFS
+ * 					protocol versions to enable ("+n")
+ * 					or disable ("-n")
+ *			size:		non-zero length of C string in @buf
+ * Output:
+ *	On success:	status of zero or more protocol versions has
+ *			been updated; passed-in buffer filled with
+ *			'\n'-terminated C string containing positive
+ *			or negative integer values representing the
+ *			current status of each protocol version;
+ *			return code is the size in bytes of the string
+ *	On error:	return code is zero or a negative errno value
+ */
+static ssize_t write_versions(struct file *file, char *buf, size_t size)
+{
+	ssize_t rv;
+
+	mutex_lock(&nfsd_mutex);
+	rv = __write_versions(file, buf, size);
+	mutex_unlock(&nfsd_mutex);
+	return rv;
+}
+
+/*
+ * Zero-length write.  Return a list of NFSD's current listener
+ * transports.
+ */
+static ssize_t __write_ports_names(char *buf, struct net *net)
+{
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	if (nn->nfsd_serv == NULL)
+		return 0;
+	return svc_xprt_names(nn->nfsd_serv, buf, SIMPLE_TRANSACTION_LIMIT);
+}
+
+/*
+ * A single 'fd' number was written, in which case it must be for
+ * a socket of a supported family/protocol, and we use it as an
+ * nfsd listener.
+ */
+static ssize_t __write_ports_addfd(char *buf, struct net *net, const struct cred *cred)
+{
+	char *mesg = buf;
+	int fd, err;
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	err = get_int(&mesg, &fd);
+	if (err != 0 || fd < 0)
+		return -EINVAL;
+
+	if (svc_alien_sock(net, fd)) {
+		printk(KERN_ERR "%s: socket net is different to NFSd's one\n", __func__);
+		return -EINVAL;
+	}
+
+	err = nfsd_create_serv(net);
+	if (err != 0)
+		return err;
+
+	err = svc_addsock(nn->nfsd_serv, fd, buf, SIMPLE_TRANSACTION_LIMIT, cred);
+	if (err < 0) {
+		nfsd_destroy(net);
+		return err;
+	}
+
+	/* Decrease the count, but don't shut down the service */
+	nn->nfsd_serv->sv_nrthreads--;
+	return err;
+}
+
+/*
+ * A transport listener is added by writing it's transport name and
+ * a port number.
+ */
+static ssize_t __write_ports_addxprt(char *buf, struct net *net, const struct cred *cred)
+{
+	char transport[16];
+	struct svc_xprt *xprt;
+	int port, err;
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	if (sscanf(buf, "%15s %5u", transport, &port) != 2)
+		return -EINVAL;
+
+	if (port < 1 || port > USHRT_MAX)
+		return -EINVAL;
+
+	err = nfsd_create_serv(net);
+	if (err != 0)
+		return err;
+
+	err = svc_create_xprt(nn->nfsd_serv, transport, net,
+				PF_INET, port, SVC_SOCK_ANONYMOUS, cred);
+	if (err < 0)
+		goto out_err;
+
+	err = svc_create_xprt(nn->nfsd_serv, transport, net,
+				PF_INET6, port, SVC_SOCK_ANONYMOUS, cred);
+	if (err < 0 && err != -EAFNOSUPPORT)
+		goto out_close;
+
+	/* Decrease the count, but don't shut down the service */
+	nn->nfsd_serv->sv_nrthreads--;
+	return 0;
+out_close:
+	xprt = svc_find_xprt(nn->nfsd_serv, transport, net, PF_INET, port);
+	if (xprt != NULL) {
+		svc_close_xprt(xprt);
+		svc_xprt_put(xprt);
+	}
+out_err:
+	if (!list_empty(&nn->nfsd_serv->sv_permsocks))
+		nn->nfsd_serv->sv_nrthreads--;
+	 else
+		nfsd_destroy(net);
+	return err;
+}
+
+static ssize_t __write_ports(struct file *file, char *buf, size_t size,
+			     struct net *net)
+{
+	if (size == 0)
+		return __write_ports_names(buf, net);
+
+	if (isdigit(buf[0]))
+		return __write_ports_addfd(buf, net, file->f_cred);
+
+	if (isalpha(buf[0]))
+		return __write_ports_addxprt(buf, net, file->f_cred);
+
+	return -EINVAL;
+}
+
+/*
+ * write_ports - Pass a socket file descriptor or transport name to listen on
+ *
+ * Input:
+ *			buf:		ignored
+ *			size:		zero
+ * Output:
+ *	On success:	passed-in buffer filled with a '\n'-terminated C
+ *			string containing a whitespace-separated list of
+ *			named NFSD listeners;
+ *			return code is the size in bytes of the string
+ *	On error:	return code is zero or a negative errno value
+ *
+ * OR
+ *
+ * Input:
+ *			buf:		C string containing an unsigned
+ *					integer value representing a bound
+ *					but unconnected socket that is to be
+ *					used as an NFSD listener; listen(3)
+ *					must be called for a SOCK_STREAM
+ *					socket, otherwise it is ignored
+ *			size:		non-zero length of C string in @buf
+ * Output:
+ *	On success:	NFS service is started;
+ *			passed-in buffer filled with a '\n'-terminated C
+ *			string containing a unique alphanumeric name of
+ *			the listener;
+ *			return code is the size in bytes of the string
+ *	On error:	return code is a negative errno value
+ *
+ * OR
+ *
+ * Input:
+ *			buf:		C string containing a transport
+ *					name and an unsigned integer value
+ *					representing the port to listen on,
+ *					separated by whitespace
+ *			size:		non-zero length of C string in @buf
+ * Output:
+ *	On success:	returns zero; NFS service is started
+ *	On error:	return code is a negative errno value
+ */
+static ssize_t write_ports(struct file *file, char *buf, size_t size)
+{
+	ssize_t rv;
+
+	mutex_lock(&nfsd_mutex);
+	rv = __write_ports(file, buf, size, netns(file));
+	mutex_unlock(&nfsd_mutex);
+	return rv;
+}
+
+
+int nfsd_max_blksize;
+
+/*
+ * write_maxblksize - Set or report the current NFS blksize
+ *
+ * Input:
+ *			buf:		ignored
+ *			size:		zero
+ *
+ * OR
+ *
+ * Input:
+ * 			buf:		C string containing an unsigned
+ * 					integer value representing the new
+ * 					NFS blksize
+ *			size:		non-zero length of C string in @buf
+ * Output:
+ *	On success:	passed-in buffer filled with '\n'-terminated C string
+ *			containing numeric value of the current NFS blksize
+ *			setting;
+ *			return code is the size in bytes of the string
+ *	On error:	return code is zero or a negative errno value
+ */
+static ssize_t write_maxblksize(struct file *file, char *buf, size_t size)
+{
+	char *mesg = buf;
+	struct nfsd_net *nn = net_generic(netns(file), nfsd_net_id);
+
+	if (size > 0) {
+		int bsize;
+		int rv = get_int(&mesg, &bsize);
+		if (rv)
+			return rv;
+		/* force bsize into allowed range and
+		 * required alignment.
+		 */
+		bsize = max_t(int, bsize, 1024);
+		bsize = min_t(int, bsize, NFSSVC_MAXBLKSIZE);
+		bsize &= ~(1024-1);
+		mutex_lock(&nfsd_mutex);
+		if (nn->nfsd_serv) {
+			mutex_unlock(&nfsd_mutex);
+			return -EBUSY;
+		}
+		nfsd_max_blksize = bsize;
+		mutex_unlock(&nfsd_mutex);
+	}
+
+	return scnprintf(buf, SIMPLE_TRANSACTION_LIMIT, "%d\n",
+							nfsd_max_blksize);
+}
+
+/*
+ * write_maxconn - Set or report the current max number of connections
+ *
+ * Input:
+ *			buf:		ignored
+ *			size:		zero
+ * OR
+ *
+ * Input:
+ * 			buf:		C string containing an unsigned
+ * 					integer value representing the new
+ * 					number of max connections
+ *			size:		non-zero length of C string in @buf
+ * Output:
+ *	On success:	passed-in buffer filled with '\n'-terminated C string
+ *			containing numeric value of max_connections setting
+ *			for this net namespace;
+ *			return code is the size in bytes of the string
+ *	On error:	return code is zero or a negative errno value
+ */
+static ssize_t write_maxconn(struct file *file, char *buf, size_t size)
+{
+	char *mesg = buf;
+	struct nfsd_net *nn = net_generic(netns(file), nfsd_net_id);
+	unsigned int maxconn = nn->max_connections;
+
+	if (size > 0) {
+		int rv = get_uint(&mesg, &maxconn);
+
+		if (rv)
+			return rv;
+		nn->max_connections = maxconn;
+	}
+
+	return scnprintf(buf, SIMPLE_TRANSACTION_LIMIT, "%u\n", maxconn);
+}
+
+#ifdef CONFIG_NFSD_V4
+static ssize_t __nfsd4_write_time(struct file *file, char *buf, size_t size,
+				  time64_t *time, struct nfsd_net *nn)
+{
+	char *mesg = buf;
+	int rv, i;
+
+	if (size > 0) {
+		if (nn->nfsd_serv)
+			return -EBUSY;
+		rv = get_int(&mesg, &i);
+		if (rv)
+			return rv;
+		/*
+		 * Some sanity checking.  We don't have a reason for
+		 * these particular numbers, but problems with the
+		 * extremes are:
+		 *	- Too short: the briefest network outage may
+		 *	  cause clients to lose all their locks.  Also,
+		 *	  the frequent polling may be wasteful.
+		 *	- Too long: do you really want reboot recovery
+		 *	  to take more than an hour?  Or to make other
+		 *	  clients wait an hour before being able to
+		 *	  revoke a dead client's locks?
+		 */
+		if (i < 10 || i > 3600)
+			return -EINVAL;
+		*time = i;
+	}
+
+	return scnprintf(buf, SIMPLE_TRANSACTION_LIMIT, "%lld\n", *time);
+}
+
+static ssize_t nfsd4_write_time(struct file *file, char *buf, size_t size,
+				time64_t *time, struct nfsd_net *nn)
+{
+	ssize_t rv;
+
+	mutex_lock(&nfsd_mutex);
+	rv = __nfsd4_write_time(file, buf, size, time, nn);
+	mutex_unlock(&nfsd_mutex);
+	return rv;
+}
+
+/*
+ * write_leasetime - Set or report the current NFSv4 lease time
+ *
+ * Input:
+ *			buf:		ignored
+ *			size:		zero
+ *
+ * OR
+ *
+ * Input:
+ *			buf:		C string containing an unsigned
+ *					integer value representing the new
+ *					NFSv4 lease expiry time
+ *			size:		non-zero length of C string in @buf
+ * Output:
+ *	On success:	passed-in buffer filled with '\n'-terminated C
+ *			string containing unsigned integer value of the
+ *			current lease expiry time;
+ *			return code is the size in bytes of the string
+ *	On error:	return code is zero or a negative errno value
+ */
+static ssize_t write_leasetime(struct file *file, char *buf, size_t size)
+{
+	struct nfsd_net *nn = net_generic(netns(file), nfsd_net_id);
+	return nfsd4_write_time(file, buf, size, &nn->nfsd4_lease, nn);
+}
+
+/*
+ * write_gracetime - Set or report current NFSv4 grace period time
+ *
+ * As above, but sets the time of the NFSv4 grace period.
+ *
+ * Note this should never be set to less than the *previous*
+ * lease-period time, but we don't try to enforce this.  (In the common
+ * case (a new boot), we don't know what the previous lease time was
+ * anyway.)
+ */
+static ssize_t write_gracetime(struct file *file, char *buf, size_t size)
+{
+	struct nfsd_net *nn = net_generic(netns(file), nfsd_net_id);
+	return nfsd4_write_time(file, buf, size, &nn->nfsd4_grace, nn);
+}
+
+static ssize_t __write_recoverydir(struct file *file, char *buf, size_t size,
+				   struct nfsd_net *nn)
+{
+	char *mesg = buf;
+	char *recdir;
+	int len, status;
+
+	if (size > 0) {
+		if (nn->nfsd_serv)
+			return -EBUSY;
+		if (size > PATH_MAX || buf[size-1] != '\n')
+			return -EINVAL;
+		buf[size-1] = 0;
+
+		recdir = mesg;
+		len = qword_get(&mesg, recdir, size);
+		if (len <= 0)
+			return -EINVAL;
+
+		status = nfs4_reset_recoverydir(recdir);
+		if (status)
+			return status;
+	}
+
+	return scnprintf(buf, SIMPLE_TRANSACTION_LIMIT, "%s\n",
+							nfs4_recoverydir());
+}
+
+/*
+ * write_recoverydir - Set or report the pathname of the recovery directory
+ *
+ * Input:
+ *			buf:		ignored
+ *			size:		zero
+ *
+ * OR
+ *
+ * Input:
+ *			buf:		C string containing the pathname
+ *					of the directory on a local file
+ *					system containing permanent NFSv4
+ *					recovery data
+ *			size:		non-zero length of C string in @buf
+ * Output:
+ *	On success:	passed-in buffer filled with '\n'-terminated C string
+ *			containing the current recovery pathname setting;
+ *			return code is the size in bytes of the string
+ *	On error:	return code is zero or a negative errno value
+ */
+static ssize_t write_recoverydir(struct file *file, char *buf, size_t size)
+{
+	ssize_t rv;
+	struct nfsd_net *nn = net_generic(netns(file), nfsd_net_id);
+
+	mutex_lock(&nfsd_mutex);
+	rv = __write_recoverydir(file, buf, size, nn);
+	mutex_unlock(&nfsd_mutex);
+	return rv;
+}
+
+/*
+ * write_v4_end_grace - release grace period for nfsd's v4.x lock manager
+ *
+ * Input:
+ *			buf:		ignored
+ *			size:		zero
+ * OR
+ *
+ * Input:
+ * 			buf:		any value
+ *			size:		non-zero length of C string in @buf
+ * Output:
+ *			passed-in buffer filled with "Y" or "N" with a newline
+ *			and NULL-terminated C string. This indicates whether
+ *			the grace period has ended in the current net
+ *			namespace. Return code is the size in bytes of the
+ *			string. Writing a string that starts with 'Y', 'y', or
+ *			'1' to the file will end the grace period for nfsd's v4
+ *			lock manager.
+ */
+static ssize_t write_v4_end_grace(struct file *file, char *buf, size_t size)
+{
+	struct nfsd_net *nn = net_generic(netns(file), nfsd_net_id);
+
+	if (size > 0) {
+		switch(buf[0]) {
+		case 'Y':
+		case 'y':
+		case '1':
+			if (!nn->nfsd_serv)
+				return -EBUSY;
+			nfsd4_end_grace(nn);
+			break;
+		default:
+			return -EINVAL;
+		}
+	}
+
+	return scnprintf(buf, SIMPLE_TRANSACTION_LIMIT, "%c\n",
+			 nn->grace_ended ? 'Y' : 'N');
+}
+
+#endif
+
+/*----------------------------------------------------------------------------*/
+/*
+ *	populating the filesystem.
+ */
+
+/* Basically copying rpc_get_inode. */
+static struct inode *nfsd_get_inode(struct super_block *sb, umode_t mode)
+{
+	struct inode *inode = new_inode(sb);
+	if (!inode)
+		return NULL;
+	/* Following advice from simple_fill_super documentation: */
+	inode->i_ino = iunique(sb, NFSD_MaxReserved);
+	inode->i_mode = mode;
+	inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
+	switch (mode & S_IFMT) {
+	case S_IFDIR:
+		inode->i_fop = &simple_dir_operations;
+		inode->i_op = &simple_dir_inode_operations;
+		inc_nlink(inode);
+	default:
+		break;
+	}
+	return inode;
+}
+
+static int __nfsd_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode, struct nfsdfs_client *ncl)
+{
+	struct inode *inode;
+
+	inode = nfsd_get_inode(dir->i_sb, mode);
+	if (!inode)
+		return -ENOMEM;
+	if (ncl) {
+		inode->i_private = ncl;
+		kref_get(&ncl->cl_ref);
+	}
+	d_add(dentry, inode);
+	inc_nlink(dir);
+	fsnotify_mkdir(dir, dentry);
+	return 0;
+}
+
+static struct dentry *nfsd_mkdir(struct dentry *parent, struct nfsdfs_client *ncl, char *name)
+{
+	struct inode *dir = parent->d_inode;
+	struct dentry *dentry;
+	int ret = -ENOMEM;
+
+	inode_lock(dir);
+	dentry = d_alloc_name(parent, name);
+	if (!dentry)
+		goto out_err;
+	ret = __nfsd_mkdir(d_inode(parent), dentry, S_IFDIR | 0600, ncl);
+	if (ret)
+		goto out_err;
+out:
+	inode_unlock(dir);
+	return dentry;
+out_err:
+	dput(dentry);
+	dentry = ERR_PTR(ret);
+	goto out;
+}
+
+static void clear_ncl(struct inode *inode)
+{
+	struct nfsdfs_client *ncl = inode->i_private;
+
+	inode->i_private = NULL;
+	kref_put(&ncl->cl_ref, ncl->cl_release);
+}
+
+static struct nfsdfs_client *__get_nfsdfs_client(struct inode *inode)
+{
+	struct nfsdfs_client *nc = inode->i_private;
+
+	if (nc)
+		kref_get(&nc->cl_ref);
+	return nc;
+}
+
+struct nfsdfs_client *get_nfsdfs_client(struct inode *inode)
+{
+	struct nfsdfs_client *nc;
+
+	inode_lock_shared(inode);
+	nc = __get_nfsdfs_client(inode);
+	inode_unlock_shared(inode);
+	return nc;
+}
+/* from __rpc_unlink */
+static void nfsdfs_remove_file(struct inode *dir, struct dentry *dentry)
+{
+	int ret;
+
+	clear_ncl(d_inode(dentry));
+	dget(dentry);
+	ret = simple_unlink(dir, dentry);
+	d_drop(dentry);
+	fsnotify_unlink(dir, dentry);
+	dput(dentry);
+	WARN_ON_ONCE(ret);
+}
+
+static void nfsdfs_remove_files(struct dentry *root)
+{
+	struct dentry *dentry, *tmp;
+
+	list_for_each_entry_safe(dentry, tmp, &root->d_subdirs, d_child) {
+		if (!simple_positive(dentry)) {
+			WARN_ON_ONCE(1); /* I think this can't happen? */
+			continue;
+		}
+		nfsdfs_remove_file(d_inode(root), dentry);
+	}
+}
+
+/* XXX: cut'n'paste from simple_fill_super; figure out if we could share
+ * code instead. */
+static  int nfsdfs_create_files(struct dentry *root,
+					const struct tree_descr *files)
+{
+	struct inode *dir = d_inode(root);
+	struct inode *inode;
+	struct dentry *dentry;
+	int i;
+
+	inode_lock(dir);
+	for (i = 0; files->name && files->name[0]; i++, files++) {
+		if (!files->name)
+			continue;
+		dentry = d_alloc_name(root, files->name);
+		if (!dentry)
+			goto out;
+		inode = nfsd_get_inode(d_inode(root)->i_sb,
+					S_IFREG | files->mode);
+		if (!inode) {
+			dput(dentry);
+			goto out;
+		}
+		inode->i_fop = files->ops;
+		inode->i_private = __get_nfsdfs_client(dir);
+		d_add(dentry, inode);
+		fsnotify_create(dir, dentry);
+	}
+	inode_unlock(dir);
+	return 0;
+out:
+	nfsdfs_remove_files(root);
+	inode_unlock(dir);
+	return -ENOMEM;
+}
+
+/* on success, returns positive number unique to that client. */
+struct dentry *nfsd_client_mkdir(struct nfsd_net *nn,
+		struct nfsdfs_client *ncl, u32 id,
+		const struct tree_descr *files)
+{
+	struct dentry *dentry;
+	char name[11];
+	int ret;
+
+	sprintf(name, "%u", id);
+
+	dentry = nfsd_mkdir(nn->nfsd_client_dir, ncl, name);
+	if (IS_ERR(dentry)) /* XXX: tossing errors? */
+		return NULL;
+	ret = nfsdfs_create_files(dentry, files);
+	if (ret) {
+		nfsd_client_rmdir(dentry);
+		return NULL;
+	}
+	return dentry;
+}
+
+/* Taken from __rpc_rmdir: */
+void nfsd_client_rmdir(struct dentry *dentry)
+{
+	struct inode *dir = d_inode(dentry->d_parent);
+	struct inode *inode = d_inode(dentry);
+	int ret;
+
+	inode_lock(dir);
+	nfsdfs_remove_files(dentry);
+	clear_ncl(inode);
+	dget(dentry);
+	ret = simple_rmdir(dir, dentry);
+	WARN_ON_ONCE(ret);
+	d_drop(dentry);
+	fsnotify_rmdir(dir, dentry);
+	dput(dentry);
+	inode_unlock(dir);
+}
+
+static int nfsd_fill_super(struct super_block *sb, struct fs_context *fc)
+{
+	struct nfsd_net *nn = net_generic(current->nsproxy->net_ns,
+							nfsd_net_id);
+	struct dentry *dentry;
+	int ret;
+
+	static const struct tree_descr nfsd_files[] = {
+		[NFSD_List] = {"exports", &exports_nfsd_operations, S_IRUGO},
+		[NFSD_Export_features] = {"export_features",
+					&export_features_operations, S_IRUGO},
+		[NFSD_FO_UnlockIP] = {"unlock_ip",
+					&transaction_ops, S_IWUSR|S_IRUSR},
+		[NFSD_FO_UnlockFS] = {"unlock_filesystem",
+					&transaction_ops, S_IWUSR|S_IRUSR},
+		[NFSD_Fh] = {"filehandle", &transaction_ops, S_IWUSR|S_IRUSR},
+		[NFSD_Threads] = {"threads", &transaction_ops, S_IWUSR|S_IRUSR},
+		[NFSD_Pool_Threads] = {"pool_threads", &transaction_ops, S_IWUSR|S_IRUSR},
+		[NFSD_Pool_Stats] = {"pool_stats", &pool_stats_operations, S_IRUGO},
+		[NFSD_Reply_Cache_Stats] = {"reply_cache_stats", &reply_cache_stats_operations, S_IRUGO},
+		[NFSD_Versions] = {"versions", &transaction_ops, S_IWUSR|S_IRUSR},
+		[NFSD_Ports] = {"portlist", &transaction_ops, S_IWUSR|S_IRUGO},
+		[NFSD_MaxBlkSize] = {"max_block_size", &transaction_ops, S_IWUSR|S_IRUGO},
+		[NFSD_MaxConnections] = {"max_connections", &transaction_ops, S_IWUSR|S_IRUGO},
+#if defined(CONFIG_SUNRPC_GSS) || defined(CONFIG_SUNRPC_GSS_MODULE)
+		[NFSD_SupportedEnctypes] = {"supported_krb5_enctypes", &supported_enctypes_ops, S_IRUGO},
+#endif /* CONFIG_SUNRPC_GSS or CONFIG_SUNRPC_GSS_MODULE */
+#ifdef CONFIG_NFSD_V4
+		[NFSD_Leasetime] = {"nfsv4leasetime", &transaction_ops, S_IWUSR|S_IRUSR},
+		[NFSD_Gracetime] = {"nfsv4gracetime", &transaction_ops, S_IWUSR|S_IRUSR},
+		[NFSD_RecoveryDir] = {"nfsv4recoverydir", &transaction_ops, S_IWUSR|S_IRUSR},
+		[NFSD_V4EndGrace] = {"v4_end_grace", &transaction_ops, S_IWUSR|S_IRUGO},
+#endif
+		/* last one */ {""}
+	};
+
+	ret = simple_fill_super(sb, 0x6e667364, nfsd_files);
+	if (ret)
+		return ret;
+	dentry = nfsd_mkdir(sb->s_root, NULL, "clients");
+	if (IS_ERR(dentry))
+		return PTR_ERR(dentry);
+	nn->nfsd_client_dir = dentry;
+	return 0;
+}
+
+static int nfsd_fs_get_tree(struct fs_context *fc)
+{
+	return get_tree_keyed(fc, nfsd_fill_super, get_net(fc->net_ns));
+}
+
+static void nfsd_fs_free_fc(struct fs_context *fc)
+{
+	if (fc->s_fs_info)
+		put_net(fc->s_fs_info);
+}
+
+static const struct fs_context_operations nfsd_fs_context_ops = {
+	.free		= nfsd_fs_free_fc,
+	.get_tree	= nfsd_fs_get_tree,
+};
+
+static int nfsd_init_fs_context(struct fs_context *fc)
+{
+	put_user_ns(fc->user_ns);
+	fc->user_ns = get_user_ns(fc->net_ns->user_ns);
+	fc->ops = &nfsd_fs_context_ops;
+	return 0;
+}
+
+static void nfsd_umount(struct super_block *sb)
+{
+	struct net *net = sb->s_fs_info;
+
+	nfsd_shutdown_threads(net);
+
+	kill_litter_super(sb);
+	put_net(net);
+}
+
+static struct file_system_type nfsd_fs_type = {
+	.owner		= THIS_MODULE,
+	.name		= "nfsd",
+	.init_fs_context = nfsd_init_fs_context,
+	.kill_sb	= nfsd_umount,
+};
+MODULE_ALIAS_FS("nfsd");
+
+#ifdef CONFIG_PROC_FS
+static int create_proc_exports_entry(void)
+{
+	struct proc_dir_entry *entry;
+
+	entry = proc_mkdir("fs/nfs", NULL);
+	if (!entry)
+		return -ENOMEM;
+	entry = proc_create("exports", 0, entry, &exports_proc_ops);
+	if (!entry) {
+		remove_proc_entry("fs/nfs", NULL);
+		return -ENOMEM;
+	}
+	return 0;
+}
+#else /* CONFIG_PROC_FS */
+static int create_proc_exports_entry(void)
+{
+	return 0;
+}
+#endif
+
+unsigned int nfsd_net_id;
+
+static __net_init int nfsd_init_net(struct net *net)
+{
+	int retval;
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	retval = nfsd_export_init(net);
+	if (retval)
+		goto out_export_error;
+	retval = nfsd_idmap_init(net);
+	if (retval)
+		goto out_idmap_error;
+	nn->nfsd_versions = NULL;
+	nn->nfsd4_minorversions = NULL;
+	retval = nfsd_reply_cache_init(nn);
+	if (retval)
+		goto out_drc_error;
+	nn->nfsd4_lease = 90;	/* default lease time */
+	nn->nfsd4_grace = 90;
+	nn->somebody_reclaimed = false;
+	nn->track_reclaim_completes = false;
+	nn->clverifier_counter = prandom_u32();
+	nn->clientid_base = prandom_u32();
+	nn->clientid_counter = nn->clientid_base + 1;
+	nn->s2s_cp_cl_id = nn->clientid_counter++;
+
+	atomic_set(&nn->ntf_refcnt, 0);
+	init_waitqueue_head(&nn->ntf_wq);
+	seqlock_init(&nn->boot_lock);
+
+	return 0;
+
+out_drc_error:
+	nfsd_idmap_shutdown(net);
+out_idmap_error:
+	nfsd_export_shutdown(net);
+out_export_error:
+	return retval;
+}
+
+static __net_exit void nfsd_exit_net(struct net *net)
+{
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	nfsd_reply_cache_shutdown(nn);
+	nfsd_idmap_shutdown(net);
+	nfsd_export_shutdown(net);
+	nfsd_netns_free_versions(net_generic(net, nfsd_net_id));
+}
+
+static struct pernet_operations nfsd_net_ops = {
+	.init = nfsd_init_net,
+	.exit = nfsd_exit_net,
+	.id   = &nfsd_net_id,
+	.size = sizeof(struct nfsd_net),
+};
+
+static int __init init_nfsd(void)
+{
+	int retval;
+	printk(KERN_INFO "Installing knfsd (copyright (C) 1996 okir@monad.swb.de).\n");
+
+	retval = nfsd4_init_slabs();
+	if (retval)
+		return retval;
+	retval = nfsd4_init_pnfs();
+	if (retval)
+		goto out_free_slabs;
+	nfsd_stat_init();	/* Statistics */
+	retval = nfsd_drc_slab_create();
+	if (retval)
+		goto out_free_stat;
+	nfsd_lockd_init();	/* lockd->nfsd callbacks */
+	retval = create_proc_exports_entry();
+	if (retval)
+		goto out_free_lockd;
+	retval = register_filesystem(&nfsd_fs_type);
+	if (retval)
+		goto out_free_exports;
+	retval = register_pernet_subsys(&nfsd_net_ops);
+	if (retval < 0)
+		goto out_free_filesystem;
+	retval = register_cld_notifier();
+	if (retval)
+		goto out_free_all;
+	return 0;
+out_free_all:
+	unregister_pernet_subsys(&nfsd_net_ops);
+out_free_filesystem:
+	unregister_filesystem(&nfsd_fs_type);
+out_free_exports:
+	remove_proc_entry("fs/nfs/exports", NULL);
+	remove_proc_entry("fs/nfs", NULL);
+out_free_lockd:
+	nfsd_lockd_shutdown();
+	nfsd_drc_slab_free();
+out_free_stat:
+	nfsd_stat_shutdown();
+	nfsd4_exit_pnfs();
+out_free_slabs:
+	nfsd4_free_slabs();
+	return retval;
+}
+
+static void __exit exit_nfsd(void)
+{
+	unregister_cld_notifier();
+	unregister_pernet_subsys(&nfsd_net_ops);
+	nfsd_drc_slab_free();
+	remove_proc_entry("fs/nfs/exports", NULL);
+	remove_proc_entry("fs/nfs", NULL);
+	nfsd_stat_shutdown();
+	nfsd_lockd_shutdown();
+	nfsd4_free_slabs();
+	nfsd4_exit_pnfs();
+	unregister_filesystem(&nfsd_fs_type);
+}
+
+MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>");
+MODULE_LICENSE("GPL");
+module_init(init_nfsd)
+module_exit(exit_nfsd)
diff --git a/fs/nfsd/nfsd.h b/fs/nfsd/nfsd.h
new file mode 100644
index 000000000..4362d295e
--- /dev/null
+++ b/fs/nfsd/nfsd.h
@@ -0,0 +1,489 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Hodge-podge collection of knfsd-related stuff.
+ * I will sort this out later.
+ *
+ * Copyright (C) 1995-1997 Olaf Kirch <okir@monad.swb.de>
+ */
+
+#ifndef LINUX_NFSD_NFSD_H
+#define LINUX_NFSD_NFSD_H
+
+#include <linux/types.h>
+#include <linux/mount.h>
+
+#include <linux/nfs.h>
+#include <linux/nfs2.h>
+#include <linux/nfs3.h>
+#include <linux/nfs4.h>
+#include <linux/sunrpc/svc.h>
+#include <linux/sunrpc/svc_xprt.h>
+#include <linux/sunrpc/msg_prot.h>
+#include <linux/sunrpc/addr.h>
+
+#include <uapi/linux/nfsd/debug.h>
+
+#include "netns.h"
+#include "stats.h"
+#include "export.h"
+
+#undef ifdebug
+#ifdef CONFIG_SUNRPC_DEBUG
+# define ifdebug(flag)		if (nfsd_debug & NFSDDBG_##flag)
+#else
+# define ifdebug(flag)		if (0)
+#endif
+
+/*
+ * nfsd version
+ */
+#define NFSD_SUPPORTED_MINOR_VERSION	2
+/*
+ * Maximum blocksizes supported by daemon under various circumstances.
+ */
+#define NFSSVC_MAXBLKSIZE       RPCSVC_MAXPAYLOAD
+/* NFSv2 is limited by the protocol specification, see RFC 1094 */
+#define NFSSVC_MAXBLKSIZE_V2    (8*1024)
+
+
+/*
+ * Largest number of bytes we need to allocate for an NFS
+ * call or reply.  Used to control buffer sizes.  We use
+ * the length of v3 WRITE, READDIR and READDIR replies
+ * which are an RPC header, up to 26 XDR units of reply
+ * data, and some page data.
+ *
+ * Note that accuracy here doesn't matter too much as the
+ * size is rounded up to a page size when allocating space.
+ */
+#define NFSD_BUFSIZE            ((RPC_MAX_HEADER_WITH_AUTH+26)*XDR_UNIT + NFSSVC_MAXBLKSIZE)
+
+struct readdir_cd {
+	__be32			err;	/* 0, nfserr, or nfserr_eof */
+};
+
+
+extern struct svc_program	nfsd_program;
+extern const struct svc_version	nfsd_version2, nfsd_version3,
+				nfsd_version4;
+extern struct mutex		nfsd_mutex;
+extern spinlock_t		nfsd_drc_lock;
+extern unsigned long		nfsd_drc_max_mem;
+extern unsigned long		nfsd_drc_mem_used;
+
+extern const struct seq_operations nfs_exports_op;
+
+/*
+ * Function prototypes.
+ */
+int		nfsd_svc(int nrservs, struct net *net, const struct cred *cred);
+int		nfsd_dispatch(struct svc_rqst *rqstp, __be32 *statp);
+
+int		nfsd_nrthreads(struct net *);
+int		nfsd_nrpools(struct net *);
+int		nfsd_get_nrthreads(int n, int *, struct net *);
+int		nfsd_set_nrthreads(int n, int *, struct net *);
+int		nfsd_pool_stats_open(struct inode *, struct file *);
+int		nfsd_pool_stats_release(struct inode *, struct file *);
+void		nfsd_shutdown_threads(struct net *net);
+
+void		nfsd_destroy(struct net *net);
+
+bool		i_am_nfsd(void);
+
+struct nfsdfs_client {
+	struct kref cl_ref;
+	void (*cl_release)(struct kref *kref);
+};
+
+struct nfsdfs_client *get_nfsdfs_client(struct inode *);
+struct dentry *nfsd_client_mkdir(struct nfsd_net *nn,
+		struct nfsdfs_client *ncl, u32 id, const struct tree_descr *);
+void nfsd_client_rmdir(struct dentry *dentry);
+
+
+#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
+#ifdef CONFIG_NFSD_V2_ACL
+extern const struct svc_version nfsd_acl_version2;
+#else
+#define nfsd_acl_version2 NULL
+#endif
+#ifdef CONFIG_NFSD_V3_ACL
+extern const struct svc_version nfsd_acl_version3;
+#else
+#define nfsd_acl_version3 NULL
+#endif
+#endif
+
+struct nfsd_net;
+
+enum vers_op {NFSD_SET, NFSD_CLEAR, NFSD_TEST, NFSD_AVAIL };
+int nfsd_vers(struct nfsd_net *nn, int vers, enum vers_op change);
+int nfsd_minorversion(struct nfsd_net *nn, u32 minorversion, enum vers_op change);
+void nfsd_reset_versions(struct nfsd_net *nn);
+int nfsd_create_serv(struct net *net);
+
+extern int nfsd_max_blksize;
+
+static inline int nfsd_v4client(struct svc_rqst *rq)
+{
+	return rq->rq_prog == NFS_PROGRAM && rq->rq_vers == 4;
+}
+static inline struct user_namespace *
+nfsd_user_namespace(const struct svc_rqst *rqstp)
+{
+	const struct cred *cred = rqstp->rq_xprt->xpt_cred;
+	return cred ? cred->user_ns : &init_user_ns;
+}
+
+/* 
+ * NFSv4 State
+ */
+#ifdef CONFIG_NFSD_V4
+extern unsigned long max_delegations;
+int nfsd4_init_slabs(void);
+void nfsd4_free_slabs(void);
+int nfs4_state_start(void);
+int nfs4_state_start_net(struct net *net);
+void nfs4_state_shutdown(void);
+void nfs4_state_shutdown_net(struct net *net);
+int nfs4_reset_recoverydir(char *recdir);
+char * nfs4_recoverydir(void);
+bool nfsd4_spo_must_allow(struct svc_rqst *rqstp);
+#else
+static inline int nfsd4_init_slabs(void) { return 0; }
+static inline void nfsd4_free_slabs(void) { }
+static inline int nfs4_state_start(void) { return 0; }
+static inline int nfs4_state_start_net(struct net *net) { return 0; }
+static inline void nfs4_state_shutdown(void) { }
+static inline void nfs4_state_shutdown_net(struct net *net) { }
+static inline int nfs4_reset_recoverydir(char *recdir) { return 0; }
+static inline char * nfs4_recoverydir(void) {return NULL; }
+static inline bool nfsd4_spo_must_allow(struct svc_rqst *rqstp)
+{
+	return false;
+}
+#endif
+
+/*
+ * lockd binding
+ */
+void		nfsd_lockd_init(void);
+void		nfsd_lockd_shutdown(void);
+
+
+/*
+ * These macros provide pre-xdr'ed values for faster operation.
+ */
+#define	nfs_ok			cpu_to_be32(NFS_OK)
+#define	nfserr_perm		cpu_to_be32(NFSERR_PERM)
+#define	nfserr_noent		cpu_to_be32(NFSERR_NOENT)
+#define	nfserr_io		cpu_to_be32(NFSERR_IO)
+#define	nfserr_nxio		cpu_to_be32(NFSERR_NXIO)
+#define	nfserr_eagain		cpu_to_be32(NFSERR_EAGAIN)
+#define	nfserr_acces		cpu_to_be32(NFSERR_ACCES)
+#define	nfserr_exist		cpu_to_be32(NFSERR_EXIST)
+#define	nfserr_xdev		cpu_to_be32(NFSERR_XDEV)
+#define	nfserr_nodev		cpu_to_be32(NFSERR_NODEV)
+#define	nfserr_notdir		cpu_to_be32(NFSERR_NOTDIR)
+#define	nfserr_isdir		cpu_to_be32(NFSERR_ISDIR)
+#define	nfserr_inval		cpu_to_be32(NFSERR_INVAL)
+#define	nfserr_fbig		cpu_to_be32(NFSERR_FBIG)
+#define	nfserr_nospc		cpu_to_be32(NFSERR_NOSPC)
+#define	nfserr_rofs		cpu_to_be32(NFSERR_ROFS)
+#define	nfserr_mlink		cpu_to_be32(NFSERR_MLINK)
+#define	nfserr_opnotsupp	cpu_to_be32(NFSERR_OPNOTSUPP)
+#define	nfserr_nametoolong	cpu_to_be32(NFSERR_NAMETOOLONG)
+#define	nfserr_notempty		cpu_to_be32(NFSERR_NOTEMPTY)
+#define	nfserr_dquot		cpu_to_be32(NFSERR_DQUOT)
+#define	nfserr_stale		cpu_to_be32(NFSERR_STALE)
+#define	nfserr_remote		cpu_to_be32(NFSERR_REMOTE)
+#define	nfserr_wflush		cpu_to_be32(NFSERR_WFLUSH)
+#define	nfserr_badhandle	cpu_to_be32(NFSERR_BADHANDLE)
+#define	nfserr_notsync		cpu_to_be32(NFSERR_NOT_SYNC)
+#define	nfserr_badcookie	cpu_to_be32(NFSERR_BAD_COOKIE)
+#define	nfserr_notsupp		cpu_to_be32(NFSERR_NOTSUPP)
+#define	nfserr_toosmall		cpu_to_be32(NFSERR_TOOSMALL)
+#define	nfserr_serverfault	cpu_to_be32(NFSERR_SERVERFAULT)
+#define	nfserr_badtype		cpu_to_be32(NFSERR_BADTYPE)
+#define	nfserr_jukebox		cpu_to_be32(NFSERR_JUKEBOX)
+#define	nfserr_denied		cpu_to_be32(NFSERR_DENIED)
+#define	nfserr_deadlock		cpu_to_be32(NFSERR_DEADLOCK)
+#define nfserr_expired          cpu_to_be32(NFSERR_EXPIRED)
+#define	nfserr_bad_cookie	cpu_to_be32(NFSERR_BAD_COOKIE)
+#define	nfserr_same		cpu_to_be32(NFSERR_SAME)
+#define	nfserr_clid_inuse	cpu_to_be32(NFSERR_CLID_INUSE)
+#define	nfserr_stale_clientid	cpu_to_be32(NFSERR_STALE_CLIENTID)
+#define	nfserr_resource		cpu_to_be32(NFSERR_RESOURCE)
+#define	nfserr_moved		cpu_to_be32(NFSERR_MOVED)
+#define	nfserr_nofilehandle	cpu_to_be32(NFSERR_NOFILEHANDLE)
+#define	nfserr_minor_vers_mismatch	cpu_to_be32(NFSERR_MINOR_VERS_MISMATCH)
+#define nfserr_share_denied	cpu_to_be32(NFSERR_SHARE_DENIED)
+#define nfserr_stale_stateid	cpu_to_be32(NFSERR_STALE_STATEID)
+#define nfserr_old_stateid	cpu_to_be32(NFSERR_OLD_STATEID)
+#define nfserr_bad_stateid	cpu_to_be32(NFSERR_BAD_STATEID)
+#define nfserr_bad_seqid	cpu_to_be32(NFSERR_BAD_SEQID)
+#define	nfserr_symlink		cpu_to_be32(NFSERR_SYMLINK)
+#define	nfserr_not_same		cpu_to_be32(NFSERR_NOT_SAME)
+#define nfserr_lock_range	cpu_to_be32(NFSERR_LOCK_RANGE)
+#define	nfserr_restorefh	cpu_to_be32(NFSERR_RESTOREFH)
+#define	nfserr_attrnotsupp	cpu_to_be32(NFSERR_ATTRNOTSUPP)
+#define	nfserr_bad_xdr		cpu_to_be32(NFSERR_BAD_XDR)
+#define	nfserr_openmode		cpu_to_be32(NFSERR_OPENMODE)
+#define	nfserr_badowner		cpu_to_be32(NFSERR_BADOWNER)
+#define	nfserr_locks_held	cpu_to_be32(NFSERR_LOCKS_HELD)
+#define	nfserr_op_illegal	cpu_to_be32(NFSERR_OP_ILLEGAL)
+#define	nfserr_grace		cpu_to_be32(NFSERR_GRACE)
+#define	nfserr_no_grace		cpu_to_be32(NFSERR_NO_GRACE)
+#define	nfserr_reclaim_bad	cpu_to_be32(NFSERR_RECLAIM_BAD)
+#define	nfserr_badname		cpu_to_be32(NFSERR_BADNAME)
+#define	nfserr_cb_path_down	cpu_to_be32(NFSERR_CB_PATH_DOWN)
+#define	nfserr_locked		cpu_to_be32(NFSERR_LOCKED)
+#define	nfserr_wrongsec		cpu_to_be32(NFSERR_WRONGSEC)
+#define nfserr_badiomode		cpu_to_be32(NFS4ERR_BADIOMODE)
+#define nfserr_badlayout		cpu_to_be32(NFS4ERR_BADLAYOUT)
+#define nfserr_bad_session_digest	cpu_to_be32(NFS4ERR_BAD_SESSION_DIGEST)
+#define nfserr_badsession		cpu_to_be32(NFS4ERR_BADSESSION)
+#define nfserr_badslot			cpu_to_be32(NFS4ERR_BADSLOT)
+#define nfserr_complete_already		cpu_to_be32(NFS4ERR_COMPLETE_ALREADY)
+#define nfserr_conn_not_bound_to_session cpu_to_be32(NFS4ERR_CONN_NOT_BOUND_TO_SESSION)
+#define nfserr_deleg_already_wanted	cpu_to_be32(NFS4ERR_DELEG_ALREADY_WANTED)
+#define nfserr_back_chan_busy		cpu_to_be32(NFS4ERR_BACK_CHAN_BUSY)
+#define nfserr_layouttrylater		cpu_to_be32(NFS4ERR_LAYOUTTRYLATER)
+#define nfserr_layoutunavailable	cpu_to_be32(NFS4ERR_LAYOUTUNAVAILABLE)
+#define nfserr_nomatching_layout	cpu_to_be32(NFS4ERR_NOMATCHING_LAYOUT)
+#define nfserr_recallconflict		cpu_to_be32(NFS4ERR_RECALLCONFLICT)
+#define nfserr_unknown_layouttype	cpu_to_be32(NFS4ERR_UNKNOWN_LAYOUTTYPE)
+#define nfserr_seq_misordered		cpu_to_be32(NFS4ERR_SEQ_MISORDERED)
+#define nfserr_sequence_pos		cpu_to_be32(NFS4ERR_SEQUENCE_POS)
+#define nfserr_req_too_big		cpu_to_be32(NFS4ERR_REQ_TOO_BIG)
+#define nfserr_rep_too_big		cpu_to_be32(NFS4ERR_REP_TOO_BIG)
+#define nfserr_rep_too_big_to_cache	cpu_to_be32(NFS4ERR_REP_TOO_BIG_TO_CACHE)
+#define nfserr_retry_uncached_rep	cpu_to_be32(NFS4ERR_RETRY_UNCACHED_REP)
+#define nfserr_unsafe_compound		cpu_to_be32(NFS4ERR_UNSAFE_COMPOUND)
+#define nfserr_too_many_ops		cpu_to_be32(NFS4ERR_TOO_MANY_OPS)
+#define nfserr_op_not_in_session	cpu_to_be32(NFS4ERR_OP_NOT_IN_SESSION)
+#define nfserr_hash_alg_unsupp		cpu_to_be32(NFS4ERR_HASH_ALG_UNSUPP)
+#define nfserr_clientid_busy		cpu_to_be32(NFS4ERR_CLIENTID_BUSY)
+#define nfserr_pnfs_io_hole		cpu_to_be32(NFS4ERR_PNFS_IO_HOLE)
+#define nfserr_seq_false_retry		cpu_to_be32(NFS4ERR_SEQ_FALSE_RETRY)
+#define nfserr_bad_high_slot		cpu_to_be32(NFS4ERR_BAD_HIGH_SLOT)
+#define nfserr_deadsession		cpu_to_be32(NFS4ERR_DEADSESSION)
+#define nfserr_encr_alg_unsupp		cpu_to_be32(NFS4ERR_ENCR_ALG_UNSUPP)
+#define nfserr_pnfs_no_layout		cpu_to_be32(NFS4ERR_PNFS_NO_LAYOUT)
+#define nfserr_not_only_op		cpu_to_be32(NFS4ERR_NOT_ONLY_OP)
+#define nfserr_wrong_cred		cpu_to_be32(NFS4ERR_WRONG_CRED)
+#define nfserr_wrong_type		cpu_to_be32(NFS4ERR_WRONG_TYPE)
+#define nfserr_dirdeleg_unavail		cpu_to_be32(NFS4ERR_DIRDELEG_UNAVAIL)
+#define nfserr_reject_deleg		cpu_to_be32(NFS4ERR_REJECT_DELEG)
+#define nfserr_returnconflict		cpu_to_be32(NFS4ERR_RETURNCONFLICT)
+#define nfserr_deleg_revoked		cpu_to_be32(NFS4ERR_DELEG_REVOKED)
+#define nfserr_partner_notsupp		cpu_to_be32(NFS4ERR_PARTNER_NOTSUPP)
+#define nfserr_partner_no_auth		cpu_to_be32(NFS4ERR_PARTNER_NO_AUTH)
+#define nfserr_union_notsupp		cpu_to_be32(NFS4ERR_UNION_NOTSUPP)
+#define nfserr_offload_denied		cpu_to_be32(NFS4ERR_OFFLOAD_DENIED)
+#define nfserr_wrong_lfs		cpu_to_be32(NFS4ERR_WRONG_LFS)
+#define nfserr_badlabel			cpu_to_be32(NFS4ERR_BADLABEL)
+#define nfserr_file_open		cpu_to_be32(NFS4ERR_FILE_OPEN)
+#define nfserr_xattr2big		cpu_to_be32(NFS4ERR_XATTR2BIG)
+#define nfserr_noxattr			cpu_to_be32(NFS4ERR_NOXATTR)
+
+/* error codes for internal use */
+/* if a request fails due to kmalloc failure, it gets dropped.
+ *  Client should resend eventually
+ */
+#define	nfserr_dropit		cpu_to_be32(30000)
+/* end-of-file indicator in readdir */
+#define	nfserr_eof		cpu_to_be32(30001)
+/* replay detected */
+#define	nfserr_replay_me	cpu_to_be32(11001)
+/* nfs41 replay detected */
+#define	nfserr_replay_cache	cpu_to_be32(11002)
+
+/* Check for dir entries '.' and '..' */
+#define isdotent(n, l)	(l < 3 && n[0] == '.' && (l == 1 || n[1] == '.'))
+
+#ifdef CONFIG_NFSD_V4
+
+/* before processing a COMPOUND operation, we have to check that there
+ * is enough space in the buffer for XDR encode to succeed.  otherwise,
+ * we might process an operation with side effects, and be unable to
+ * tell the client that the operation succeeded.
+ *
+ * COMPOUND_SLACK_SPACE - this is the minimum bytes of buffer space
+ * needed to encode an "ordinary" _successful_ operation.  (GETATTR,
+ * READ, READDIR, and READLINK have their own buffer checks.)  if we
+ * fall below this level, we fail the next operation with NFS4ERR_RESOURCE.
+ *
+ * COMPOUND_ERR_SLACK_SPACE - this is the minimum bytes of buffer space
+ * needed to encode an operation which has failed with NFS4ERR_RESOURCE.
+ * care is taken to ensure that we never fall below this level for any
+ * reason.
+ */
+#define	COMPOUND_SLACK_SPACE		140    /* OP_GETFH */
+#define COMPOUND_ERR_SLACK_SPACE	16     /* OP_SETATTR */
+
+#define NFSD_LAUNDROMAT_MINTIMEOUT      1   /* seconds */
+
+/*
+ * The following attributes are currently not supported by the NFSv4 server:
+ *    ARCHIVE       (deprecated anyway)
+ *    HIDDEN        (unlikely to be supported any time soon)
+ *    MIMETYPE      (unlikely to be supported any time soon)
+ *    QUOTA_*       (will be supported in a forthcoming patch)
+ *    SYSTEM        (unlikely to be supported any time soon)
+ *    TIME_BACKUP   (unlikely to be supported any time soon)
+ *    TIME_CREATE   (unlikely to be supported any time soon)
+ */
+#define NFSD4_SUPPORTED_ATTRS_WORD0                                                         \
+(FATTR4_WORD0_SUPPORTED_ATTRS   | FATTR4_WORD0_TYPE         | FATTR4_WORD0_FH_EXPIRE_TYPE   \
+ | FATTR4_WORD0_CHANGE          | FATTR4_WORD0_SIZE         | FATTR4_WORD0_LINK_SUPPORT     \
+ | FATTR4_WORD0_SYMLINK_SUPPORT | FATTR4_WORD0_NAMED_ATTR   | FATTR4_WORD0_FSID             \
+ | FATTR4_WORD0_UNIQUE_HANDLES  | FATTR4_WORD0_LEASE_TIME   | FATTR4_WORD0_RDATTR_ERROR     \
+ | FATTR4_WORD0_ACLSUPPORT      | FATTR4_WORD0_CANSETTIME   | FATTR4_WORD0_CASE_INSENSITIVE \
+ | FATTR4_WORD0_CASE_PRESERVING | FATTR4_WORD0_CHOWN_RESTRICTED                             \
+ | FATTR4_WORD0_FILEHANDLE      | FATTR4_WORD0_FILEID       | FATTR4_WORD0_FILES_AVAIL      \
+ | FATTR4_WORD0_FILES_FREE      | FATTR4_WORD0_FILES_TOTAL  | FATTR4_WORD0_FS_LOCATIONS | FATTR4_WORD0_HOMOGENEOUS      \
+ | FATTR4_WORD0_MAXFILESIZE     | FATTR4_WORD0_MAXLINK      | FATTR4_WORD0_MAXNAME          \
+ | FATTR4_WORD0_MAXREAD         | FATTR4_WORD0_MAXWRITE     | FATTR4_WORD0_ACL)
+
+#define NFSD4_SUPPORTED_ATTRS_WORD1                                                         \
+(FATTR4_WORD1_MODE              | FATTR4_WORD1_NO_TRUNC     | FATTR4_WORD1_NUMLINKS         \
+ | FATTR4_WORD1_OWNER	        | FATTR4_WORD1_OWNER_GROUP  | FATTR4_WORD1_RAWDEV           \
+ | FATTR4_WORD1_SPACE_AVAIL     | FATTR4_WORD1_SPACE_FREE   | FATTR4_WORD1_SPACE_TOTAL      \
+ | FATTR4_WORD1_SPACE_USED      | FATTR4_WORD1_TIME_ACCESS  | FATTR4_WORD1_TIME_ACCESS_SET  \
+ | FATTR4_WORD1_TIME_DELTA   | FATTR4_WORD1_TIME_METADATA    \
+ | FATTR4_WORD1_TIME_MODIFY     | FATTR4_WORD1_TIME_MODIFY_SET | FATTR4_WORD1_MOUNTED_ON_FILEID)
+
+#define NFSD4_SUPPORTED_ATTRS_WORD2 0
+
+/* 4.1 */
+#ifdef CONFIG_NFSD_PNFS
+#define PNFSD_SUPPORTED_ATTRS_WORD1	FATTR4_WORD1_FS_LAYOUT_TYPES
+#define PNFSD_SUPPORTED_ATTRS_WORD2 \
+(FATTR4_WORD2_LAYOUT_BLKSIZE	| FATTR4_WORD2_LAYOUT_TYPES)
+#else
+#define PNFSD_SUPPORTED_ATTRS_WORD1	0
+#define PNFSD_SUPPORTED_ATTRS_WORD2	0
+#endif /* CONFIG_NFSD_PNFS */
+
+#define NFSD4_1_SUPPORTED_ATTRS_WORD0 \
+	NFSD4_SUPPORTED_ATTRS_WORD0
+
+#define NFSD4_1_SUPPORTED_ATTRS_WORD1 \
+	(NFSD4_SUPPORTED_ATTRS_WORD1	| PNFSD_SUPPORTED_ATTRS_WORD1)
+
+#define NFSD4_1_SUPPORTED_ATTRS_WORD2 \
+	(NFSD4_SUPPORTED_ATTRS_WORD2	| PNFSD_SUPPORTED_ATTRS_WORD2 | \
+	 FATTR4_WORD2_SUPPATTR_EXCLCREAT)
+
+/* 4.2 */
+#ifdef CONFIG_NFSD_V4_SECURITY_LABEL
+#define NFSD4_2_SECURITY_ATTRS		FATTR4_WORD2_SECURITY_LABEL
+#else
+#define NFSD4_2_SECURITY_ATTRS		0
+#endif
+
+#define NFSD4_2_SUPPORTED_ATTRS_WORD2 \
+	(NFSD4_1_SUPPORTED_ATTRS_WORD2 | \
+	FATTR4_WORD2_CHANGE_ATTR_TYPE | \
+	FATTR4_WORD2_MODE_UMASK | \
+	NFSD4_2_SECURITY_ATTRS | \
+	FATTR4_WORD2_XATTR_SUPPORT)
+
+extern const u32 nfsd_suppattrs[3][3];
+
+static inline __be32 nfsd4_set_netaddr(struct sockaddr *addr,
+				    struct nfs42_netaddr *netaddr)
+{
+	struct sockaddr_in *sin = (struct sockaddr_in *)addr;
+	struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)addr;
+	unsigned int port;
+	size_t ret_addr, ret_port;
+
+	switch (addr->sa_family) {
+	case AF_INET:
+		port = ntohs(sin->sin_port);
+		sprintf(netaddr->netid, "tcp");
+		netaddr->netid_len = 3;
+		break;
+	case AF_INET6:
+		port = ntohs(sin6->sin6_port);
+		sprintf(netaddr->netid, "tcp6");
+		netaddr->netid_len = 4;
+		break;
+	default:
+		return nfserr_inval;
+	}
+	ret_addr = rpc_ntop(addr, netaddr->addr, sizeof(netaddr->addr));
+	ret_port = snprintf(netaddr->addr + ret_addr,
+			    RPCBIND_MAXUADDRLEN + 1 - ret_addr,
+			    ".%u.%u", port >> 8, port & 0xff);
+	WARN_ON(ret_port >= RPCBIND_MAXUADDRLEN + 1 - ret_addr);
+	netaddr->addr_len = ret_addr + ret_port;
+	return 0;
+}
+
+static inline bool bmval_is_subset(const u32 *bm1, const u32 *bm2)
+{
+	return !((bm1[0] & ~bm2[0]) ||
+	         (bm1[1] & ~bm2[1]) ||
+		 (bm1[2] & ~bm2[2]));
+}
+
+static inline bool nfsd_attrs_supported(u32 minorversion, const u32 *bmval)
+{
+	return bmval_is_subset(bmval, nfsd_suppattrs[minorversion]);
+}
+
+/* These will return ERR_INVAL if specified in GETATTR or READDIR. */
+#define NFSD_WRITEONLY_ATTRS_WORD1 \
+	(FATTR4_WORD1_TIME_ACCESS_SET   | FATTR4_WORD1_TIME_MODIFY_SET)
+
+/*
+ * These are the only attrs allowed in CREATE/OPEN/SETATTR. Don't add
+ * a writeable attribute here without also adding code to parse it to
+ * nfsd4_decode_fattr().
+ */
+#define NFSD_WRITEABLE_ATTRS_WORD0 \
+	(FATTR4_WORD0_SIZE | FATTR4_WORD0_ACL)
+#define NFSD_WRITEABLE_ATTRS_WORD1 \
+	(FATTR4_WORD1_MODE | FATTR4_WORD1_OWNER | FATTR4_WORD1_OWNER_GROUP \
+	| FATTR4_WORD1_TIME_ACCESS_SET | FATTR4_WORD1_TIME_MODIFY_SET)
+#ifdef CONFIG_NFSD_V4_SECURITY_LABEL
+#define MAYBE_FATTR4_WORD2_SECURITY_LABEL \
+	FATTR4_WORD2_SECURITY_LABEL
+#else
+#define MAYBE_FATTR4_WORD2_SECURITY_LABEL 0
+#endif
+#define NFSD_WRITEABLE_ATTRS_WORD2 \
+	(FATTR4_WORD2_MODE_UMASK \
+	| MAYBE_FATTR4_WORD2_SECURITY_LABEL)
+
+#define NFSD_SUPPATTR_EXCLCREAT_WORD0 \
+	NFSD_WRITEABLE_ATTRS_WORD0
+/*
+ * we currently store the exclusive create verifier in the v_{a,m}time
+ * attributes so the client can't set these at create time using EXCLUSIVE4_1
+ */
+#define NFSD_SUPPATTR_EXCLCREAT_WORD1 \
+	(NFSD_WRITEABLE_ATTRS_WORD1 & \
+	 ~(FATTR4_WORD1_TIME_ACCESS_SET | FATTR4_WORD1_TIME_MODIFY_SET))
+#define NFSD_SUPPATTR_EXCLCREAT_WORD2 \
+	NFSD_WRITEABLE_ATTRS_WORD2
+
+extern int nfsd4_is_junction(struct dentry *dentry);
+extern int register_cld_notifier(void);
+extern void unregister_cld_notifier(void);
+#else /* CONFIG_NFSD_V4 */
+static inline int nfsd4_is_junction(struct dentry *dentry)
+{
+	return 0;
+}
+
+#define register_cld_notifier() 0
+#define unregister_cld_notifier() do { } while(0)
+
+#endif /* CONFIG_NFSD_V4 */
+
+#endif /* LINUX_NFSD_NFSD_H */
diff --git a/fs/nfsd/nfsfh.c b/fs/nfsd/nfsfh.c
new file mode 100644
index 000000000..c81dbbad8
--- /dev/null
+++ b/fs/nfsd/nfsfh.c
@@ -0,0 +1,713 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * NFS server file handle treatment.
+ *
+ * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
+ * Portions Copyright (C) 1999 G. Allen Morris III <gam3@acm.org>
+ * Extensive rewrite by Neil Brown <neilb@cse.unsw.edu.au> Southern-Spring 1999
+ * ... and again Southern-Winter 2001 to support export_operations
+ */
+
+#include <linux/exportfs.h>
+
+#include <linux/sunrpc/svcauth_gss.h>
+#include "nfsd.h"
+#include "vfs.h"
+#include "auth.h"
+#include "trace.h"
+
+#define NFSDDBG_FACILITY		NFSDDBG_FH
+
+
+/*
+ * our acceptability function.
+ * if NOSUBTREECHECK, accept anything
+ * if not, require that we can walk up to exp->ex_dentry
+ * doing some checks on the 'x' bits
+ */
+static int nfsd_acceptable(void *expv, struct dentry *dentry)
+{
+	struct svc_export *exp = expv;
+	int rv;
+	struct dentry *tdentry;
+	struct dentry *parent;
+
+	if (exp->ex_flags & NFSEXP_NOSUBTREECHECK)
+		return 1;
+
+	tdentry = dget(dentry);
+	while (tdentry != exp->ex_path.dentry && !IS_ROOT(tdentry)) {
+		/* make sure parents give x permission to user */
+		int err;
+		parent = dget_parent(tdentry);
+		err = inode_permission(d_inode(parent), MAY_EXEC);
+		if (err < 0) {
+			dput(parent);
+			break;
+		}
+		dput(tdentry);
+		tdentry = parent;
+	}
+	if (tdentry != exp->ex_path.dentry)
+		dprintk("nfsd_acceptable failed at %p %pd\n", tdentry, tdentry);
+	rv = (tdentry == exp->ex_path.dentry);
+	dput(tdentry);
+	return rv;
+}
+
+/* Type check. The correct error return for type mismatches does not seem to be
+ * generally agreed upon. SunOS seems to use EISDIR if file isn't S_IFREG; a
+ * comment in the NFSv3 spec says this is incorrect (implementation notes for
+ * the write call).
+ */
+static inline __be32
+nfsd_mode_check(struct svc_rqst *rqstp, struct dentry *dentry,
+		umode_t requested)
+{
+	umode_t mode = d_inode(dentry)->i_mode & S_IFMT;
+
+	if (requested == 0) /* the caller doesn't care */
+		return nfs_ok;
+	if (mode == requested) {
+		if (mode == S_IFDIR && !d_can_lookup(dentry)) {
+			WARN_ON_ONCE(1);
+			return nfserr_notdir;
+		}
+		return nfs_ok;
+	}
+	/*
+	 * v4 has an error more specific than err_notdir which we should
+	 * return in preference to err_notdir:
+	 */
+	if (rqstp->rq_vers == 4 && mode == S_IFLNK)
+		return nfserr_symlink;
+	if (requested == S_IFDIR)
+		return nfserr_notdir;
+	if (mode == S_IFDIR)
+		return nfserr_isdir;
+	return nfserr_inval;
+}
+
+static bool nfsd_originating_port_ok(struct svc_rqst *rqstp, int flags)
+{
+	if (flags & NFSEXP_INSECURE_PORT)
+		return true;
+	/* We don't require gss requests to use low ports: */
+	if (rqstp->rq_cred.cr_flavor >= RPC_AUTH_GSS)
+		return true;
+	return test_bit(RQ_SECURE, &rqstp->rq_flags);
+}
+
+static __be32 nfsd_setuser_and_check_port(struct svc_rqst *rqstp,
+					  struct svc_export *exp)
+{
+	int flags = nfsexp_flags(rqstp, exp);
+
+	/* Check if the request originated from a secure port. */
+	if (!nfsd_originating_port_ok(rqstp, flags)) {
+		RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
+		dprintk("nfsd: request from insecure port %s!\n",
+		        svc_print_addr(rqstp, buf, sizeof(buf)));
+		return nfserr_perm;
+	}
+
+	/* Set user creds for this exportpoint */
+	return nfserrno(nfsd_setuser(rqstp, exp));
+}
+
+static inline __be32 check_pseudo_root(struct svc_rqst *rqstp,
+	struct dentry *dentry, struct svc_export *exp)
+{
+	if (!(exp->ex_flags & NFSEXP_V4ROOT))
+		return nfs_ok;
+	/*
+	 * v2/v3 clients have no need for the V4ROOT export--they use
+	 * the mount protocl instead; also, further V4ROOT checks may be
+	 * in v4-specific code, in which case v2/v3 clients could bypass
+	 * them.
+	 */
+	if (!nfsd_v4client(rqstp))
+		return nfserr_stale;
+	/*
+	 * We're exposing only the directories and symlinks that have to be
+	 * traversed on the way to real exports:
+	 */
+	if (unlikely(!d_is_dir(dentry) &&
+		     !d_is_symlink(dentry)))
+		return nfserr_stale;
+	/*
+	 * A pseudoroot export gives permission to access only one
+	 * single directory; the kernel has to make another upcall
+	 * before granting access to anything else under it:
+	 */
+	if (unlikely(dentry != exp->ex_path.dentry))
+		return nfserr_stale;
+	return nfs_ok;
+}
+
+/*
+ * Use the given filehandle to look up the corresponding export and
+ * dentry.  On success, the results are used to set fh_export and
+ * fh_dentry.
+ */
+static __be32 nfsd_set_fh_dentry(struct svc_rqst *rqstp, struct svc_fh *fhp)
+{
+	struct knfsd_fh	*fh = &fhp->fh_handle;
+	struct fid *fid = NULL, sfid;
+	struct svc_export *exp;
+	struct dentry *dentry;
+	int fileid_type;
+	int data_left = fh->fh_size/4;
+	__be32 error;
+
+	error = nfserr_stale;
+	if (rqstp->rq_vers > 2)
+		error = nfserr_badhandle;
+	if (rqstp->rq_vers == 4 && fh->fh_size == 0)
+		return nfserr_nofilehandle;
+
+	if (fh->fh_version == 1) {
+		int len;
+
+		if (--data_left < 0)
+			return error;
+		if (fh->fh_auth_type != 0)
+			return error;
+		len = key_len(fh->fh_fsid_type) / 4;
+		if (len == 0)
+			return error;
+		if  (fh->fh_fsid_type == FSID_MAJOR_MINOR) {
+			/* deprecated, convert to type 3 */
+			len = key_len(FSID_ENCODE_DEV)/4;
+			fh->fh_fsid_type = FSID_ENCODE_DEV;
+			/*
+			 * struct knfsd_fh uses host-endian fields, which are
+			 * sometimes used to hold net-endian values. This
+			 * confuses sparse, so we must use __force here to
+			 * keep it from complaining.
+			 */
+			fh->fh_fsid[0] = new_encode_dev(MKDEV(ntohl((__force __be32)fh->fh_fsid[0]),
+							ntohl((__force __be32)fh->fh_fsid[1])));
+			fh->fh_fsid[1] = fh->fh_fsid[2];
+		}
+		data_left -= len;
+		if (data_left < 0)
+			return error;
+		exp = rqst_exp_find(rqstp, fh->fh_fsid_type, fh->fh_fsid);
+		fid = (struct fid *)(fh->fh_fsid + len);
+	} else {
+		__u32 tfh[2];
+		dev_t xdev;
+		ino_t xino;
+
+		if (fh->fh_size != NFS_FHSIZE)
+			return error;
+		/* assume old filehandle format */
+		xdev = old_decode_dev(fh->ofh_xdev);
+		xino = u32_to_ino_t(fh->ofh_xino);
+		mk_fsid(FSID_DEV, tfh, xdev, xino, 0, NULL);
+		exp = rqst_exp_find(rqstp, FSID_DEV, tfh);
+	}
+
+	error = nfserr_stale;
+	if (IS_ERR(exp)) {
+		trace_nfsd_set_fh_dentry_badexport(rqstp, fhp, PTR_ERR(exp));
+
+		if (PTR_ERR(exp) == -ENOENT)
+			return error;
+
+		return nfserrno(PTR_ERR(exp));
+	}
+
+	if (exp->ex_flags & NFSEXP_NOSUBTREECHECK) {
+		/* Elevate privileges so that the lack of 'r' or 'x'
+		 * permission on some parent directory will
+		 * not stop exportfs_decode_fh from being able
+		 * to reconnect a directory into the dentry cache.
+		 * The same problem can affect "SUBTREECHECK" exports,
+		 * but as nfsd_acceptable depends on correct
+		 * access control settings being in effect, we cannot
+		 * fix that case easily.
+		 */
+		struct cred *new = prepare_creds();
+		if (!new) {
+			error =  nfserrno(-ENOMEM);
+			goto out;
+		}
+		new->cap_effective =
+			cap_raise_nfsd_set(new->cap_effective,
+					   new->cap_permitted);
+		put_cred(override_creds(new));
+		put_cred(new);
+	} else {
+		error = nfsd_setuser_and_check_port(rqstp, exp);
+		if (error)
+			goto out;
+	}
+
+	/*
+	 * Look up the dentry using the NFS file handle.
+	 */
+	error = nfserr_stale;
+	if (rqstp->rq_vers > 2)
+		error = nfserr_badhandle;
+
+	if (fh->fh_version != 1) {
+		sfid.i32.ino = fh->ofh_ino;
+		sfid.i32.gen = fh->ofh_generation;
+		sfid.i32.parent_ino = fh->ofh_dirino;
+		fid = &sfid;
+		data_left = 3;
+		if (fh->ofh_dirino == 0)
+			fileid_type = FILEID_INO32_GEN;
+		else
+			fileid_type = FILEID_INO32_GEN_PARENT;
+	} else
+		fileid_type = fh->fh_fileid_type;
+
+	if (fileid_type == FILEID_ROOT)
+		dentry = dget(exp->ex_path.dentry);
+	else {
+		dentry = exportfs_decode_fh(exp->ex_path.mnt, fid,
+				data_left, fileid_type,
+				nfsd_acceptable, exp);
+		if (IS_ERR_OR_NULL(dentry))
+			trace_nfsd_set_fh_dentry_badhandle(rqstp, fhp,
+					dentry ?  PTR_ERR(dentry) : -ESTALE);
+	}
+	if (dentry == NULL)
+		goto out;
+	if (IS_ERR(dentry)) {
+		if (PTR_ERR(dentry) != -EINVAL)
+			error = nfserrno(PTR_ERR(dentry));
+		goto out;
+	}
+
+	if (d_is_dir(dentry) &&
+			(dentry->d_flags & DCACHE_DISCONNECTED)) {
+		printk("nfsd: find_fh_dentry returned a DISCONNECTED directory: %pd2\n",
+				dentry);
+	}
+
+	fhp->fh_dentry = dentry;
+	fhp->fh_export = exp;
+	return 0;
+out:
+	exp_put(exp);
+	return error;
+}
+
+/**
+ * fh_verify - filehandle lookup and access checking
+ * @rqstp: pointer to current rpc request
+ * @fhp: filehandle to be verified
+ * @type: expected type of object pointed to by filehandle
+ * @access: type of access needed to object
+ *
+ * Look up a dentry from the on-the-wire filehandle, check the client's
+ * access to the export, and set the current task's credentials.
+ *
+ * Regardless of success or failure of fh_verify(), fh_put() should be
+ * called on @fhp when the caller is finished with the filehandle.
+ *
+ * fh_verify() may be called multiple times on a given filehandle, for
+ * example, when processing an NFSv4 compound.  The first call will look
+ * up a dentry using the on-the-wire filehandle.  Subsequent calls will
+ * skip the lookup and just perform the other checks and possibly change
+ * the current task's credentials.
+ *
+ * @type specifies the type of object expected using one of the S_IF*
+ * constants defined in include/linux/stat.h.  The caller may use zero
+ * to indicate that it doesn't care, or a negative integer to indicate
+ * that it expects something not of the given type.
+ *
+ * @access is formed from the NFSD_MAY_* constants defined in
+ * fs/nfsd/vfs.h.
+ */
+__be32
+fh_verify(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type, int access)
+{
+	struct svc_export *exp;
+	struct dentry	*dentry;
+	__be32		error;
+
+	dprintk("nfsd: fh_verify(%s)\n", SVCFH_fmt(fhp));
+
+	if (!fhp->fh_dentry) {
+		error = nfsd_set_fh_dentry(rqstp, fhp);
+		if (error)
+			goto out;
+	}
+	dentry = fhp->fh_dentry;
+	exp = fhp->fh_export;
+	/*
+	 * We still have to do all these permission checks, even when
+	 * fh_dentry is already set:
+	 * 	- fh_verify may be called multiple times with different
+	 * 	  "access" arguments (e.g. nfsd_proc_create calls
+	 * 	  fh_verify(...,NFSD_MAY_EXEC) first, then later (in
+	 * 	  nfsd_create) calls fh_verify(...,NFSD_MAY_CREATE).
+	 *	- in the NFSv4 case, the filehandle may have been filled
+	 *	  in by fh_compose, and given a dentry, but further
+	 *	  compound operations performed with that filehandle
+	 *	  still need permissions checks.  In the worst case, a
+	 *	  mountpoint crossing may have changed the export
+	 *	  options, and we may now need to use a different uid
+	 *	  (for example, if different id-squashing options are in
+	 *	  effect on the new filesystem).
+	 */
+	error = check_pseudo_root(rqstp, dentry, exp);
+	if (error)
+		goto out;
+
+	error = nfsd_setuser_and_check_port(rqstp, exp);
+	if (error)
+		goto out;
+
+	error = nfsd_mode_check(rqstp, dentry, type);
+	if (error)
+		goto out;
+
+	/*
+	 * pseudoflavor restrictions are not enforced on NLM,
+	 * which clients virtually always use auth_sys for,
+	 * even while using RPCSEC_GSS for NFS.
+	 */
+	if (access & NFSD_MAY_LOCK || access & NFSD_MAY_BYPASS_GSS)
+		goto skip_pseudoflavor_check;
+	/*
+	 * Clients may expect to be able to use auth_sys during mount,
+	 * even if they use gss for everything else; see section 2.3.2
+	 * of rfc 2623.
+	 */
+	if (access & NFSD_MAY_BYPASS_GSS_ON_ROOT
+			&& exp->ex_path.dentry == dentry)
+		goto skip_pseudoflavor_check;
+
+	error = check_nfsd_access(exp, rqstp);
+	if (error)
+		goto out;
+
+skip_pseudoflavor_check:
+	/* Finally, check access permissions. */
+	error = nfsd_permission(rqstp, exp, dentry, access);
+
+	if (error) {
+		dprintk("fh_verify: %pd2 permission failure, "
+			"acc=%x, error=%d\n",
+			dentry,
+			access, ntohl(error));
+	}
+out:
+	if (error == nfserr_stale)
+		nfsdstats.fh_stale++;
+	return error;
+}
+
+
+/*
+ * Compose a file handle for an NFS reply.
+ *
+ * Note that when first composed, the dentry may not yet have
+ * an inode.  In this case a call to fh_update should be made
+ * before the fh goes out on the wire ...
+ */
+static void _fh_update(struct svc_fh *fhp, struct svc_export *exp,
+		struct dentry *dentry)
+{
+	if (dentry != exp->ex_path.dentry) {
+		struct fid *fid = (struct fid *)
+			(fhp->fh_handle.fh_fsid + fhp->fh_handle.fh_size/4 - 1);
+		int maxsize = (fhp->fh_maxsize - fhp->fh_handle.fh_size)/4;
+		int subtreecheck = !(exp->ex_flags & NFSEXP_NOSUBTREECHECK);
+
+		fhp->fh_handle.fh_fileid_type =
+			exportfs_encode_fh(dentry, fid, &maxsize, subtreecheck);
+		fhp->fh_handle.fh_size += maxsize * 4;
+	} else {
+		fhp->fh_handle.fh_fileid_type = FILEID_ROOT;
+	}
+}
+
+/*
+ * for composing old style file handles
+ */
+static inline void _fh_update_old(struct dentry *dentry,
+				  struct svc_export *exp,
+				  struct knfsd_fh *fh)
+{
+	fh->ofh_ino = ino_t_to_u32(d_inode(dentry)->i_ino);
+	fh->ofh_generation = d_inode(dentry)->i_generation;
+	if (d_is_dir(dentry) ||
+	    (exp->ex_flags & NFSEXP_NOSUBTREECHECK))
+		fh->ofh_dirino = 0;
+}
+
+static bool is_root_export(struct svc_export *exp)
+{
+	return exp->ex_path.dentry == exp->ex_path.dentry->d_sb->s_root;
+}
+
+static struct super_block *exp_sb(struct svc_export *exp)
+{
+	return exp->ex_path.dentry->d_sb;
+}
+
+static bool fsid_type_ok_for_exp(u8 fsid_type, struct svc_export *exp)
+{
+	switch (fsid_type) {
+	case FSID_DEV:
+		if (!old_valid_dev(exp_sb(exp)->s_dev))
+			return false;
+		fallthrough;
+	case FSID_MAJOR_MINOR:
+	case FSID_ENCODE_DEV:
+		return exp_sb(exp)->s_type->fs_flags & FS_REQUIRES_DEV;
+	case FSID_NUM:
+		return exp->ex_flags & NFSEXP_FSID;
+	case FSID_UUID8:
+	case FSID_UUID16:
+		if (!is_root_export(exp))
+			return false;
+		fallthrough;
+	case FSID_UUID4_INUM:
+	case FSID_UUID16_INUM:
+		return exp->ex_uuid != NULL;
+	}
+	return true;
+}
+
+
+static void set_version_and_fsid_type(struct svc_fh *fhp, struct svc_export *exp, struct svc_fh *ref_fh)
+{
+	u8 version;
+	u8 fsid_type;
+retry:
+	version = 1;
+	if (ref_fh && ref_fh->fh_export == exp) {
+		version = ref_fh->fh_handle.fh_version;
+		fsid_type = ref_fh->fh_handle.fh_fsid_type;
+
+		ref_fh = NULL;
+
+		switch (version) {
+		case 0xca:
+			fsid_type = FSID_DEV;
+			break;
+		case 1:
+			break;
+		default:
+			goto retry;
+		}
+
+		/*
+		 * As the fsid -> filesystem mapping was guided by
+		 * user-space, there is no guarantee that the filesystem
+		 * actually supports that fsid type. If it doesn't we
+		 * loop around again without ref_fh set.
+		 */
+		if (!fsid_type_ok_for_exp(fsid_type, exp))
+			goto retry;
+	} else if (exp->ex_flags & NFSEXP_FSID) {
+		fsid_type = FSID_NUM;
+	} else if (exp->ex_uuid) {
+		if (fhp->fh_maxsize >= 64) {
+			if (is_root_export(exp))
+				fsid_type = FSID_UUID16;
+			else
+				fsid_type = FSID_UUID16_INUM;
+		} else {
+			if (is_root_export(exp))
+				fsid_type = FSID_UUID8;
+			else
+				fsid_type = FSID_UUID4_INUM;
+		}
+	} else if (!old_valid_dev(exp_sb(exp)->s_dev))
+		/* for newer device numbers, we must use a newer fsid format */
+		fsid_type = FSID_ENCODE_DEV;
+	else
+		fsid_type = FSID_DEV;
+	fhp->fh_handle.fh_version = version;
+	if (version)
+		fhp->fh_handle.fh_fsid_type = fsid_type;
+}
+
+__be32
+fh_compose(struct svc_fh *fhp, struct svc_export *exp, struct dentry *dentry,
+	   struct svc_fh *ref_fh)
+{
+	/* ref_fh is a reference file handle.
+	 * if it is non-null and for the same filesystem, then we should compose
+	 * a filehandle which is of the same version, where possible.
+	 * Currently, that means that if ref_fh->fh_handle.fh_version == 0xca
+	 * Then create a 32byte filehandle using nfs_fhbase_old
+	 *
+	 */
+
+	struct inode * inode = d_inode(dentry);
+	dev_t ex_dev = exp_sb(exp)->s_dev;
+
+	dprintk("nfsd: fh_compose(exp %02x:%02x/%ld %pd2, ino=%ld)\n",
+		MAJOR(ex_dev), MINOR(ex_dev),
+		(long) d_inode(exp->ex_path.dentry)->i_ino,
+		dentry,
+		(inode ? inode->i_ino : 0));
+
+	/* Choose filehandle version and fsid type based on
+	 * the reference filehandle (if it is in the same export)
+	 * or the export options.
+	 */
+	set_version_and_fsid_type(fhp, exp, ref_fh);
+
+	if (ref_fh == fhp)
+		fh_put(ref_fh);
+
+	if (fhp->fh_locked || fhp->fh_dentry) {
+		printk(KERN_ERR "fh_compose: fh %pd2 not initialized!\n",
+		       dentry);
+	}
+	if (fhp->fh_maxsize < NFS_FHSIZE)
+		printk(KERN_ERR "fh_compose: called with maxsize %d! %pd2\n",
+		       fhp->fh_maxsize,
+		       dentry);
+
+	fhp->fh_dentry = dget(dentry); /* our internal copy */
+	fhp->fh_export = exp_get(exp);
+
+	if (fhp->fh_handle.fh_version == 0xca) {
+		/* old style filehandle please */
+		memset(&fhp->fh_handle.fh_base, 0, NFS_FHSIZE);
+		fhp->fh_handle.fh_size = NFS_FHSIZE;
+		fhp->fh_handle.ofh_dcookie = 0xfeebbaca;
+		fhp->fh_handle.ofh_dev =  old_encode_dev(ex_dev);
+		fhp->fh_handle.ofh_xdev = fhp->fh_handle.ofh_dev;
+		fhp->fh_handle.ofh_xino =
+			ino_t_to_u32(d_inode(exp->ex_path.dentry)->i_ino);
+		fhp->fh_handle.ofh_dirino = ino_t_to_u32(parent_ino(dentry));
+		if (inode)
+			_fh_update_old(dentry, exp, &fhp->fh_handle);
+	} else {
+		fhp->fh_handle.fh_size =
+			key_len(fhp->fh_handle.fh_fsid_type) + 4;
+		fhp->fh_handle.fh_auth_type = 0;
+
+		mk_fsid(fhp->fh_handle.fh_fsid_type,
+			fhp->fh_handle.fh_fsid,
+			ex_dev,
+			d_inode(exp->ex_path.dentry)->i_ino,
+			exp->ex_fsid, exp->ex_uuid);
+
+		if (inode)
+			_fh_update(fhp, exp, dentry);
+		if (fhp->fh_handle.fh_fileid_type == FILEID_INVALID) {
+			fh_put(fhp);
+			return nfserr_opnotsupp;
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * Update file handle information after changing a dentry.
+ * This is only called by nfsd_create, nfsd_create_v3 and nfsd_proc_create
+ */
+__be32
+fh_update(struct svc_fh *fhp)
+{
+	struct dentry *dentry;
+
+	if (!fhp->fh_dentry)
+		goto out_bad;
+
+	dentry = fhp->fh_dentry;
+	if (d_really_is_negative(dentry))
+		goto out_negative;
+	if (fhp->fh_handle.fh_version != 1) {
+		_fh_update_old(dentry, fhp->fh_export, &fhp->fh_handle);
+	} else {
+		if (fhp->fh_handle.fh_fileid_type != FILEID_ROOT)
+			return 0;
+
+		_fh_update(fhp, fhp->fh_export, dentry);
+		if (fhp->fh_handle.fh_fileid_type == FILEID_INVALID)
+			return nfserr_opnotsupp;
+	}
+	return 0;
+out_bad:
+	printk(KERN_ERR "fh_update: fh not verified!\n");
+	return nfserr_serverfault;
+out_negative:
+	printk(KERN_ERR "fh_update: %pd2 still negative!\n",
+		dentry);
+	return nfserr_serverfault;
+}
+
+/*
+ * Release a file handle.
+ */
+void
+fh_put(struct svc_fh *fhp)
+{
+	struct dentry * dentry = fhp->fh_dentry;
+	struct svc_export * exp = fhp->fh_export;
+	if (dentry) {
+		fh_unlock(fhp);
+		fhp->fh_dentry = NULL;
+		dput(dentry);
+		fh_clear_wcc(fhp);
+	}
+	fh_drop_write(fhp);
+	if (exp) {
+		exp_put(exp);
+		fhp->fh_export = NULL;
+	}
+	return;
+}
+
+/*
+ * Shorthand for dprintk()'s
+ */
+char * SVCFH_fmt(struct svc_fh *fhp)
+{
+	struct knfsd_fh *fh = &fhp->fh_handle;
+
+	static char buf[80];
+	sprintf(buf, "%d: %08x %08x %08x %08x %08x %08x",
+		fh->fh_size,
+		fh->fh_base.fh_pad[0],
+		fh->fh_base.fh_pad[1],
+		fh->fh_base.fh_pad[2],
+		fh->fh_base.fh_pad[3],
+		fh->fh_base.fh_pad[4],
+		fh->fh_base.fh_pad[5]);
+	return buf;
+}
+
+enum fsid_source fsid_source(struct svc_fh *fhp)
+{
+	if (fhp->fh_handle.fh_version != 1)
+		return FSIDSOURCE_DEV;
+	switch(fhp->fh_handle.fh_fsid_type) {
+	case FSID_DEV:
+	case FSID_ENCODE_DEV:
+	case FSID_MAJOR_MINOR:
+		if (exp_sb(fhp->fh_export)->s_type->fs_flags & FS_REQUIRES_DEV)
+			return FSIDSOURCE_DEV;
+		break;
+	case FSID_NUM:
+		if (fhp->fh_export->ex_flags & NFSEXP_FSID)
+			return FSIDSOURCE_FSID;
+		break;
+	default:
+		break;
+	}
+	/* either a UUID type filehandle, or the filehandle doesn't
+	 * match the export.
+	 */
+	if (fhp->fh_export->ex_flags & NFSEXP_FSID)
+		return FSIDSOURCE_FSID;
+	if (fhp->fh_export->ex_uuid)
+		return FSIDSOURCE_UUID;
+	return FSIDSOURCE_DEV;
+}
diff --git a/fs/nfsd/nfsfh.h b/fs/nfsd/nfsfh.h
new file mode 100644
index 000000000..56cfbc361
--- /dev/null
+++ b/fs/nfsd/nfsfh.h
@@ -0,0 +1,326 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 1995, 1996, 1997 Olaf Kirch <okir@monad.swb.de>
+ *
+ * This file describes the layout of the file handles as passed
+ * over the wire.
+ */
+#ifndef _LINUX_NFSD_NFSFH_H
+#define _LINUX_NFSD_NFSFH_H
+
+#include <linux/crc32.h>
+#include <linux/sunrpc/svc.h>
+#include <uapi/linux/nfsd/nfsfh.h>
+#include <linux/iversion.h>
+
+static inline __u32 ino_t_to_u32(ino_t ino)
+{
+	return (__u32) ino;
+}
+
+static inline ino_t u32_to_ino_t(__u32 uino)
+{
+	return (ino_t) uino;
+}
+
+/*
+ * This is the internal representation of an NFS handle used in knfsd.
+ * pre_mtime/post_version will be used to support wcc_attr's in NFSv3.
+ */
+typedef struct svc_fh {
+	struct knfsd_fh		fh_handle;	/* FH data */
+	int			fh_maxsize;	/* max size for fh_handle */
+	struct dentry *		fh_dentry;	/* validated dentry */
+	struct svc_export *	fh_export;	/* export pointer */
+
+	bool			fh_locked;	/* inode locked by us */
+	bool			fh_want_write;	/* remount protection taken */
+	int			fh_flags;	/* FH flags */
+#ifdef CONFIG_NFSD_V3
+	bool			fh_post_saved;	/* post-op attrs saved */
+	bool			fh_pre_saved;	/* pre-op attrs saved */
+
+	/* Pre-op attributes saved during fh_lock */
+	__u64			fh_pre_size;	/* size before operation */
+	struct timespec64	fh_pre_mtime;	/* mtime before oper */
+	struct timespec64	fh_pre_ctime;	/* ctime before oper */
+	/*
+	 * pre-op nfsv4 change attr: note must check IS_I_VERSION(inode)
+	 *  to find out if it is valid.
+	 */
+	u64			fh_pre_change;
+
+	/* Post-op attributes saved in fh_unlock */
+	struct kstat		fh_post_attr;	/* full attrs after operation */
+	u64			fh_post_change; /* nfsv4 change; see above */
+#endif /* CONFIG_NFSD_V3 */
+
+} svc_fh;
+#define NFSD4_FH_FOREIGN (1<<0)
+#define SET_FH_FLAG(c, f) ((c)->fh_flags |= (f))
+#define HAS_FH_FLAG(c, f) ((c)->fh_flags & (f))
+
+enum nfsd_fsid {
+	FSID_DEV = 0,
+	FSID_NUM,
+	FSID_MAJOR_MINOR,
+	FSID_ENCODE_DEV,
+	FSID_UUID4_INUM,
+	FSID_UUID8,
+	FSID_UUID16,
+	FSID_UUID16_INUM,
+};
+
+enum fsid_source {
+	FSIDSOURCE_DEV,
+	FSIDSOURCE_FSID,
+	FSIDSOURCE_UUID,
+};
+extern enum fsid_source fsid_source(struct svc_fh *fhp);
+
+
+/*
+ * This might look a little large to "inline" but in all calls except
+ * one, 'vers' is constant so moste of the function disappears.
+ *
+ * In some cases the values are considered to be host endian and in
+ * others, net endian. fsidv is always considered to be u32 as the
+ * callers don't know which it will be. So we must use __force to keep
+ * sparse from complaining. Since these values are opaque to the
+ * client, that shouldn't be a problem.
+ */
+static inline void mk_fsid(int vers, u32 *fsidv, dev_t dev, ino_t ino,
+			   u32 fsid, unsigned char *uuid)
+{
+	u32 *up;
+	switch(vers) {
+	case FSID_DEV:
+		fsidv[0] = (__force __u32)htonl((MAJOR(dev)<<16) |
+				 MINOR(dev));
+		fsidv[1] = ino_t_to_u32(ino);
+		break;
+	case FSID_NUM:
+		fsidv[0] = fsid;
+		break;
+	case FSID_MAJOR_MINOR:
+		fsidv[0] = (__force __u32)htonl(MAJOR(dev));
+		fsidv[1] = (__force __u32)htonl(MINOR(dev));
+		fsidv[2] = ino_t_to_u32(ino);
+		break;
+
+	case FSID_ENCODE_DEV:
+		fsidv[0] = new_encode_dev(dev);
+		fsidv[1] = ino_t_to_u32(ino);
+		break;
+
+	case FSID_UUID4_INUM:
+		/* 4 byte fsid and inode number */
+		up = (u32*)uuid;
+		fsidv[0] = ino_t_to_u32(ino);
+		fsidv[1] = up[0] ^ up[1] ^ up[2] ^ up[3];
+		break;
+
+	case FSID_UUID8:
+		/* 8 byte fsid  */
+		up = (u32*)uuid;
+		fsidv[0] = up[0] ^ up[2];
+		fsidv[1] = up[1] ^ up[3];
+		break;
+
+	case FSID_UUID16:
+		/* 16 byte fsid - NFSv3+ only */
+		memcpy(fsidv, uuid, 16);
+		break;
+
+	case FSID_UUID16_INUM:
+		/* 8 byte inode and 16 byte fsid */
+		*(u64*)fsidv = (u64)ino;
+		memcpy(fsidv+2, uuid, 16);
+		break;
+	default: BUG();
+	}
+}
+
+static inline int key_len(int type)
+{
+	switch(type) {
+	case FSID_DEV:		return 8;
+	case FSID_NUM: 		return 4;
+	case FSID_MAJOR_MINOR:	return 12;
+	case FSID_ENCODE_DEV:	return 8;
+	case FSID_UUID4_INUM:	return 8;
+	case FSID_UUID8:	return 8;
+	case FSID_UUID16:	return 16;
+	case FSID_UUID16_INUM:	return 24;
+	default: return 0;
+	}
+}
+
+/*
+ * Shorthand for dprintk()'s
+ */
+extern char * SVCFH_fmt(struct svc_fh *fhp);
+
+/*
+ * Function prototypes
+ */
+__be32	fh_verify(struct svc_rqst *, struct svc_fh *, umode_t, int);
+__be32	fh_compose(struct svc_fh *, struct svc_export *, struct dentry *, struct svc_fh *);
+__be32	fh_update(struct svc_fh *);
+void	fh_put(struct svc_fh *);
+
+static __inline__ struct svc_fh *
+fh_copy(struct svc_fh *dst, struct svc_fh *src)
+{
+	WARN_ON(src->fh_dentry || src->fh_locked);
+			
+	*dst = *src;
+	return dst;
+}
+
+static inline void
+fh_copy_shallow(struct knfsd_fh *dst, struct knfsd_fh *src)
+{
+	dst->fh_size = src->fh_size;
+	memcpy(&dst->fh_base, &src->fh_base, src->fh_size);
+}
+
+static __inline__ struct svc_fh *
+fh_init(struct svc_fh *fhp, int maxsize)
+{
+	memset(fhp, 0, sizeof(*fhp));
+	fhp->fh_maxsize = maxsize;
+	return fhp;
+}
+
+static inline bool fh_match(struct knfsd_fh *fh1, struct knfsd_fh *fh2)
+{
+	if (fh1->fh_size != fh2->fh_size)
+		return false;
+	if (memcmp(fh1->fh_base.fh_pad, fh2->fh_base.fh_pad, fh1->fh_size) != 0)
+		return false;
+	return true;
+}
+
+static inline bool fh_fsid_match(struct knfsd_fh *fh1, struct knfsd_fh *fh2)
+{
+	if (fh1->fh_fsid_type != fh2->fh_fsid_type)
+		return false;
+	if (memcmp(fh1->fh_fsid, fh2->fh_fsid, key_len(fh1->fh_fsid_type)) != 0)
+		return false;
+	return true;
+}
+
+#ifdef CONFIG_CRC32
+/**
+ * knfsd_fh_hash - calculate the crc32 hash for the filehandle
+ * @fh - pointer to filehandle
+ *
+ * returns a crc32 hash for the filehandle that is compatible with
+ * the one displayed by "wireshark".
+ */
+
+static inline u32
+knfsd_fh_hash(struct knfsd_fh *fh)
+{
+	return ~crc32_le(0xFFFFFFFF, (unsigned char *)&fh->fh_base, fh->fh_size);
+}
+#else
+static inline u32
+knfsd_fh_hash(struct knfsd_fh *fh)
+{
+	return 0;
+}
+#endif
+
+#ifdef CONFIG_NFSD_V3
+/*
+ * The wcc data stored in current_fh should be cleared
+ * between compound ops.
+ */
+static inline void
+fh_clear_wcc(struct svc_fh *fhp)
+{
+	fhp->fh_post_saved = false;
+	fhp->fh_pre_saved = false;
+}
+
+/*
+ * We could use i_version alone as the change attribute.  However,
+ * i_version can go backwards after a reboot.  On its own that doesn't
+ * necessarily cause a problem, but if i_version goes backwards and then
+ * is incremented again it could reuse a value that was previously used
+ * before boot, and a client who queried the two values might
+ * incorrectly assume nothing changed.
+ *
+ * By using both ctime and the i_version counter we guarantee that as
+ * long as time doesn't go backwards we never reuse an old value.
+ */
+static inline u64 nfsd4_change_attribute(struct kstat *stat,
+					 struct inode *inode)
+{
+	u64 chattr;
+
+	chattr =  stat->ctime.tv_sec;
+	chattr <<= 30;
+	chattr += stat->ctime.tv_nsec;
+	chattr += inode_query_iversion(inode);
+	return chattr;
+}
+
+extern void fill_pre_wcc(struct svc_fh *fhp);
+extern void fill_post_wcc(struct svc_fh *fhp);
+#else
+#define fh_clear_wcc(ignored)
+#define fill_pre_wcc(ignored)
+#define fill_post_wcc(notused)
+#endif /* CONFIG_NFSD_V3 */
+
+
+/*
+ * Lock a file handle/inode
+ * NOTE: both fh_lock and fh_unlock are done "by hand" in
+ * vfs.c:nfsd_rename as it needs to grab 2 i_mutex's at once
+ * so, any changes here should be reflected there.
+ */
+
+static inline void
+fh_lock_nested(struct svc_fh *fhp, unsigned int subclass)
+{
+	struct dentry	*dentry = fhp->fh_dentry;
+	struct inode	*inode;
+
+	BUG_ON(!dentry);
+
+	if (fhp->fh_locked) {
+		printk(KERN_WARNING "fh_lock: %pd2 already locked!\n",
+			dentry);
+		return;
+	}
+
+	inode = d_inode(dentry);
+	inode_lock_nested(inode, subclass);
+	fill_pre_wcc(fhp);
+	fhp->fh_locked = true;
+}
+
+static inline void
+fh_lock(struct svc_fh *fhp)
+{
+	fh_lock_nested(fhp, I_MUTEX_NORMAL);
+}
+
+/*
+ * Unlock a file handle/inode
+ */
+static inline void
+fh_unlock(struct svc_fh *fhp)
+{
+	if (fhp->fh_locked) {
+		fill_post_wcc(fhp);
+		inode_unlock(d_inode(fhp->fh_dentry));
+		fhp->fh_locked = false;
+	}
+}
+
+#endif /* _LINUX_NFSD_NFSFH_H */
diff --git a/fs/nfsd/nfsproc.c b/fs/nfsd/nfsproc.c
new file mode 100644
index 000000000..bbd01e839
--- /dev/null
+++ b/fs/nfsd/nfsproc.c
@@ -0,0 +1,856 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Process version 2 NFS requests.
+ *
+ * Copyright (C) 1995-1997 Olaf Kirch <okir@monad.swb.de>
+ */
+
+#include <linux/namei.h>
+
+#include "cache.h"
+#include "xdr.h"
+#include "vfs.h"
+
+#define NFSDDBG_FACILITY		NFSDDBG_PROC
+
+static __be32
+nfsd_proc_null(struct svc_rqst *rqstp)
+{
+	return rpc_success;
+}
+
+/*
+ * Get a file's attributes
+ * N.B. After this call resp->fh needs an fh_put
+ */
+static __be32
+nfsd_proc_getattr(struct svc_rqst *rqstp)
+{
+	struct nfsd_fhandle *argp = rqstp->rq_argp;
+	struct nfsd_attrstat *resp = rqstp->rq_resp;
+
+	dprintk("nfsd: GETATTR  %s\n", SVCFH_fmt(&argp->fh));
+
+	fh_copy(&resp->fh, &argp->fh);
+	resp->status = fh_verify(rqstp, &resp->fh, 0,
+				 NFSD_MAY_NOP | NFSD_MAY_BYPASS_GSS_ON_ROOT);
+	if (resp->status != nfs_ok)
+		goto out;
+	resp->status = fh_getattr(&resp->fh, &resp->stat);
+out:
+	return rpc_success;
+}
+
+/*
+ * Set a file's attributes
+ * N.B. After this call resp->fh needs an fh_put
+ */
+static __be32
+nfsd_proc_setattr(struct svc_rqst *rqstp)
+{
+	struct nfsd_sattrargs *argp = rqstp->rq_argp;
+	struct nfsd_attrstat *resp = rqstp->rq_resp;
+	struct iattr *iap = &argp->attrs;
+	struct svc_fh *fhp;
+
+	dprintk("nfsd: SETATTR  %s, valid=%x, size=%ld\n",
+		SVCFH_fmt(&argp->fh),
+		argp->attrs.ia_valid, (long) argp->attrs.ia_size);
+
+	fhp = fh_copy(&resp->fh, &argp->fh);
+
+	/*
+	 * NFSv2 does not differentiate between "set-[ac]time-to-now"
+	 * which only requires access, and "set-[ac]time-to-X" which
+	 * requires ownership.
+	 * So if it looks like it might be "set both to the same time which
+	 * is close to now", and if setattr_prepare fails, then we
+	 * convert to "set to now" instead of "set to explicit time"
+	 *
+	 * We only call setattr_prepare as the last test as technically
+	 * it is not an interface that we should be using.
+	 */
+#define BOTH_TIME_SET (ATTR_ATIME_SET | ATTR_MTIME_SET)
+#define	MAX_TOUCH_TIME_ERROR (30*60)
+	if ((iap->ia_valid & BOTH_TIME_SET) == BOTH_TIME_SET &&
+	    iap->ia_mtime.tv_sec == iap->ia_atime.tv_sec) {
+		/*
+		 * Looks probable.
+		 *
+		 * Now just make sure time is in the right ballpark.
+		 * Solaris, at least, doesn't seem to care what the time
+		 * request is.  We require it be within 30 minutes of now.
+		 */
+		time64_t delta = iap->ia_atime.tv_sec - ktime_get_real_seconds();
+
+		resp->status = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP);
+		if (resp->status != nfs_ok)
+			goto out;
+
+		if (delta < 0)
+			delta = -delta;
+		if (delta < MAX_TOUCH_TIME_ERROR &&
+		    setattr_prepare(fhp->fh_dentry, iap) != 0) {
+			/*
+			 * Turn off ATTR_[AM]TIME_SET but leave ATTR_[AM]TIME.
+			 * This will cause notify_change to set these times
+			 * to "now"
+			 */
+			iap->ia_valid &= ~BOTH_TIME_SET;
+		}
+	}
+
+	resp->status = nfsd_setattr(rqstp, fhp, iap, 0, (time64_t)0);
+	if (resp->status != nfs_ok)
+		goto out;
+
+	resp->status = fh_getattr(&resp->fh, &resp->stat);
+out:
+	return rpc_success;
+}
+
+/* Obsolete, replaced by MNTPROC_MNT. */
+static __be32
+nfsd_proc_root(struct svc_rqst *rqstp)
+{
+	return rpc_success;
+}
+
+/*
+ * Look up a path name component
+ * Note: the dentry in the resp->fh may be negative if the file
+ * doesn't exist yet.
+ * N.B. After this call resp->fh needs an fh_put
+ */
+static __be32
+nfsd_proc_lookup(struct svc_rqst *rqstp)
+{
+	struct nfsd_diropargs *argp = rqstp->rq_argp;
+	struct nfsd_diropres *resp = rqstp->rq_resp;
+
+	dprintk("nfsd: LOOKUP   %s %.*s\n",
+		SVCFH_fmt(&argp->fh), argp->len, argp->name);
+
+	fh_init(&resp->fh, NFS_FHSIZE);
+	resp->status = nfsd_lookup(rqstp, &argp->fh, argp->name, argp->len,
+				   &resp->fh);
+	fh_put(&argp->fh);
+	if (resp->status != nfs_ok)
+		goto out;
+
+	resp->status = fh_getattr(&resp->fh, &resp->stat);
+out:
+	return rpc_success;
+}
+
+/*
+ * Read a symlink.
+ */
+static __be32
+nfsd_proc_readlink(struct svc_rqst *rqstp)
+{
+	struct nfsd_readlinkargs *argp = rqstp->rq_argp;
+	struct nfsd_readlinkres *resp = rqstp->rq_resp;
+
+	dprintk("nfsd: READLINK %s\n", SVCFH_fmt(&argp->fh));
+
+	/* Read the symlink. */
+	resp->len = NFS_MAXPATHLEN;
+	resp->status = nfsd_readlink(rqstp, &argp->fh, argp->buffer, &resp->len);
+
+	fh_put(&argp->fh);
+	return rpc_success;
+}
+
+/*
+ * Read a portion of a file.
+ * N.B. After this call resp->fh needs an fh_put
+ */
+static __be32
+nfsd_proc_read(struct svc_rqst *rqstp)
+{
+	struct nfsd_readargs *argp = rqstp->rq_argp;
+	struct nfsd_readres *resp = rqstp->rq_resp;
+	u32 eof;
+
+	dprintk("nfsd: READ    %s %d bytes at %d\n",
+		SVCFH_fmt(&argp->fh),
+		argp->count, argp->offset);
+
+	/* Obtain buffer pointer for payload. 19 is 1 word for
+	 * status, 17 words for fattr, and 1 word for the byte count.
+	 */
+
+	if (NFSSVC_MAXBLKSIZE_V2 < argp->count) {
+		char buf[RPC_MAX_ADDRBUFLEN];
+		printk(KERN_NOTICE
+			"oversized read request from %s (%d bytes)\n",
+				svc_print_addr(rqstp, buf, sizeof(buf)),
+				argp->count);
+		argp->count = NFSSVC_MAXBLKSIZE_V2;
+	}
+	svc_reserve_auth(rqstp, (19<<2) + argp->count + 4);
+
+	resp->count = argp->count;
+	resp->status = nfsd_read(rqstp, fh_copy(&resp->fh, &argp->fh),
+				 argp->offset,
+				 rqstp->rq_vec, argp->vlen,
+				 &resp->count,
+				 &eof);
+	if (resp->status == nfs_ok)
+		resp->status = fh_getattr(&resp->fh, &resp->stat);
+	else if (resp->status == nfserr_jukebox)
+		return rpc_drop_reply;
+	return rpc_success;
+}
+
+/* Reserved */
+static __be32
+nfsd_proc_writecache(struct svc_rqst *rqstp)
+{
+	return rpc_success;
+}
+
+/*
+ * Write data to a file
+ * N.B. After this call resp->fh needs an fh_put
+ */
+static __be32
+nfsd_proc_write(struct svc_rqst *rqstp)
+{
+	struct nfsd_writeargs *argp = rqstp->rq_argp;
+	struct nfsd_attrstat *resp = rqstp->rq_resp;
+	unsigned long cnt = argp->len;
+	unsigned int nvecs;
+
+	dprintk("nfsd: WRITE    %s %u bytes at %d\n",
+		SVCFH_fmt(&argp->fh),
+		argp->len, argp->offset);
+
+	nvecs = svc_fill_write_vector(rqstp, rqstp->rq_arg.pages,
+				      &argp->first, cnt);
+	if (!nvecs) {
+		resp->status = nfserr_io;
+		goto out;
+	}
+
+	resp->status = nfsd_write(rqstp, fh_copy(&resp->fh, &argp->fh),
+				  argp->offset, rqstp->rq_vec, nvecs,
+				  &cnt, NFS_DATA_SYNC, NULL);
+	if (resp->status == nfs_ok)
+		resp->status = fh_getattr(&resp->fh, &resp->stat);
+	else if (resp->status == nfserr_jukebox)
+		return rpc_drop_reply;
+out:
+	return rpc_success;
+}
+
+/*
+ * CREATE processing is complicated. The keyword here is `overloaded.'
+ * The parent directory is kept locked between the check for existence
+ * and the actual create() call in compliance with VFS protocols.
+ * N.B. After this call _both_ argp->fh and resp->fh need an fh_put
+ */
+static __be32
+nfsd_proc_create(struct svc_rqst *rqstp)
+{
+	struct nfsd_createargs *argp = rqstp->rq_argp;
+	struct nfsd_diropres *resp = rqstp->rq_resp;
+	svc_fh		*dirfhp = &argp->fh;
+	svc_fh		*newfhp = &resp->fh;
+	struct iattr	*attr = &argp->attrs;
+	struct inode	*inode;
+	struct dentry	*dchild;
+	int		type, mode;
+	int		hosterr;
+	dev_t		rdev = 0, wanted = new_decode_dev(attr->ia_size);
+
+	dprintk("nfsd: CREATE   %s %.*s\n",
+		SVCFH_fmt(dirfhp), argp->len, argp->name);
+
+	/* First verify the parent file handle */
+	resp->status = fh_verify(rqstp, dirfhp, S_IFDIR, NFSD_MAY_EXEC);
+	if (resp->status != nfs_ok)
+		goto done; /* must fh_put dirfhp even on error */
+
+	/* Check for NFSD_MAY_WRITE in nfsd_create if necessary */
+
+	resp->status = nfserr_exist;
+	if (isdotent(argp->name, argp->len))
+		goto done;
+	hosterr = fh_want_write(dirfhp);
+	if (hosterr) {
+		resp->status = nfserrno(hosterr);
+		goto done;
+	}
+
+	fh_lock_nested(dirfhp, I_MUTEX_PARENT);
+	dchild = lookup_one_len(argp->name, dirfhp->fh_dentry, argp->len);
+	if (IS_ERR(dchild)) {
+		resp->status = nfserrno(PTR_ERR(dchild));
+		goto out_unlock;
+	}
+	fh_init(newfhp, NFS_FHSIZE);
+	resp->status = fh_compose(newfhp, dirfhp->fh_export, dchild, dirfhp);
+	if (!resp->status && d_really_is_negative(dchild))
+		resp->status = nfserr_noent;
+	dput(dchild);
+	if (resp->status) {
+		if (resp->status != nfserr_noent)
+			goto out_unlock;
+		/*
+		 * If the new file handle wasn't verified, we can't tell
+		 * whether the file exists or not. Time to bail ...
+		 */
+		resp->status = nfserr_acces;
+		if (!newfhp->fh_dentry) {
+			printk(KERN_WARNING 
+				"nfsd_proc_create: file handle not verified\n");
+			goto out_unlock;
+		}
+	}
+
+	inode = d_inode(newfhp->fh_dentry);
+
+	/* Unfudge the mode bits */
+	if (attr->ia_valid & ATTR_MODE) {
+		type = attr->ia_mode & S_IFMT;
+		mode = attr->ia_mode & ~S_IFMT;
+		if (!type) {
+			/* no type, so if target exists, assume same as that,
+			 * else assume a file */
+			if (inode) {
+				type = inode->i_mode & S_IFMT;
+				switch(type) {
+				case S_IFCHR:
+				case S_IFBLK:
+					/* reserve rdev for later checking */
+					rdev = inode->i_rdev;
+					attr->ia_valid |= ATTR_SIZE;
+
+					fallthrough;
+				case S_IFIFO:
+					/* this is probably a permission check..
+					 * at least IRIX implements perm checking on
+					 *   echo thing > device-special-file-or-pipe
+					 * by doing a CREATE with type==0
+					 */
+					resp->status = nfsd_permission(rqstp,
+								 newfhp->fh_export,
+								 newfhp->fh_dentry,
+								 NFSD_MAY_WRITE|NFSD_MAY_LOCAL_ACCESS);
+					if (resp->status && resp->status != nfserr_rofs)
+						goto out_unlock;
+				}
+			} else
+				type = S_IFREG;
+		}
+	} else if (inode) {
+		type = inode->i_mode & S_IFMT;
+		mode = inode->i_mode & ~S_IFMT;
+	} else {
+		type = S_IFREG;
+		mode = 0;	/* ??? */
+	}
+
+	attr->ia_valid |= ATTR_MODE;
+	attr->ia_mode = mode;
+
+	/* Special treatment for non-regular files according to the
+	 * gospel of sun micro
+	 */
+	if (type != S_IFREG) {
+		if (type != S_IFBLK && type != S_IFCHR) {
+			rdev = 0;
+		} else if (type == S_IFCHR && !(attr->ia_valid & ATTR_SIZE)) {
+			/* If you think you've seen the worst, grok this. */
+			type = S_IFIFO;
+		} else {
+			/* Okay, char or block special */
+			if (!rdev)
+				rdev = wanted;
+		}
+
+		/* we've used the SIZE information, so discard it */
+		attr->ia_valid &= ~ATTR_SIZE;
+
+		/* Make sure the type and device matches */
+		resp->status = nfserr_exist;
+		if (inode && inode_wrong_type(inode, type))
+			goto out_unlock;
+	}
+
+	resp->status = nfs_ok;
+	if (!inode) {
+		/* File doesn't exist. Create it and set attrs */
+		resp->status = nfsd_create_locked(rqstp, dirfhp, argp->name,
+						  argp->len, attr, type, rdev,
+						  newfhp);
+	} else if (type == S_IFREG) {
+		dprintk("nfsd:   existing %s, valid=%x, size=%ld\n",
+			argp->name, attr->ia_valid, (long) attr->ia_size);
+		/* File already exists. We ignore all attributes except
+		 * size, so that creat() behaves exactly like
+		 * open(..., O_CREAT|O_TRUNC|O_WRONLY).
+		 */
+		attr->ia_valid &= ATTR_SIZE;
+		if (attr->ia_valid)
+			resp->status = nfsd_setattr(rqstp, newfhp, attr, 0,
+						    (time64_t)0);
+	}
+
+out_unlock:
+	/* We don't really need to unlock, as fh_put does it. */
+	fh_unlock(dirfhp);
+	fh_drop_write(dirfhp);
+done:
+	fh_put(dirfhp);
+	if (resp->status != nfs_ok)
+		goto out;
+	resp->status = fh_getattr(&resp->fh, &resp->stat);
+out:
+	return rpc_success;
+}
+
+static __be32
+nfsd_proc_remove(struct svc_rqst *rqstp)
+{
+	struct nfsd_diropargs *argp = rqstp->rq_argp;
+	struct nfsd_stat *resp = rqstp->rq_resp;
+
+	dprintk("nfsd: REMOVE   %s %.*s\n", SVCFH_fmt(&argp->fh),
+		argp->len, argp->name);
+
+	/* Unlink. -SIFDIR means file must not be a directory */
+	resp->status = nfsd_unlink(rqstp, &argp->fh, -S_IFDIR,
+				   argp->name, argp->len);
+	fh_put(&argp->fh);
+	return rpc_success;
+}
+
+static __be32
+nfsd_proc_rename(struct svc_rqst *rqstp)
+{
+	struct nfsd_renameargs *argp = rqstp->rq_argp;
+	struct nfsd_stat *resp = rqstp->rq_resp;
+
+	dprintk("nfsd: RENAME   %s %.*s -> \n",
+		SVCFH_fmt(&argp->ffh), argp->flen, argp->fname);
+	dprintk("nfsd:        ->  %s %.*s\n",
+		SVCFH_fmt(&argp->tfh), argp->tlen, argp->tname);
+
+	resp->status = nfsd_rename(rqstp, &argp->ffh, argp->fname, argp->flen,
+				   &argp->tfh, argp->tname, argp->tlen);
+	fh_put(&argp->ffh);
+	fh_put(&argp->tfh);
+	return rpc_success;
+}
+
+static __be32
+nfsd_proc_link(struct svc_rqst *rqstp)
+{
+	struct nfsd_linkargs *argp = rqstp->rq_argp;
+	struct nfsd_stat *resp = rqstp->rq_resp;
+
+	dprintk("nfsd: LINK     %s ->\n",
+		SVCFH_fmt(&argp->ffh));
+	dprintk("nfsd:    %s %.*s\n",
+		SVCFH_fmt(&argp->tfh),
+		argp->tlen,
+		argp->tname);
+
+	resp->status = nfsd_link(rqstp, &argp->tfh, argp->tname, argp->tlen,
+				 &argp->ffh);
+	fh_put(&argp->ffh);
+	fh_put(&argp->tfh);
+	return rpc_success;
+}
+
+static __be32
+nfsd_proc_symlink(struct svc_rqst *rqstp)
+{
+	struct nfsd_symlinkargs *argp = rqstp->rq_argp;
+	struct nfsd_stat *resp = rqstp->rq_resp;
+	struct svc_fh	newfh;
+
+	if (argp->tlen > NFS_MAXPATHLEN) {
+		resp->status = nfserr_nametoolong;
+		goto out;
+	}
+
+	argp->tname = svc_fill_symlink_pathname(rqstp, &argp->first,
+						page_address(rqstp->rq_arg.pages[0]),
+						argp->tlen);
+	if (IS_ERR(argp->tname)) {
+		resp->status = nfserrno(PTR_ERR(argp->tname));
+		goto out;
+	}
+
+	dprintk("nfsd: SYMLINK  %s %.*s -> %.*s\n",
+		SVCFH_fmt(&argp->ffh), argp->flen, argp->fname,
+		argp->tlen, argp->tname);
+
+	fh_init(&newfh, NFS_FHSIZE);
+	resp->status = nfsd_symlink(rqstp, &argp->ffh, argp->fname, argp->flen,
+				    argp->tname, &newfh);
+
+	kfree(argp->tname);
+	fh_put(&argp->ffh);
+	fh_put(&newfh);
+out:
+	return rpc_success;
+}
+
+/*
+ * Make directory. This operation is not idempotent.
+ * N.B. After this call resp->fh needs an fh_put
+ */
+static __be32
+nfsd_proc_mkdir(struct svc_rqst *rqstp)
+{
+	struct nfsd_createargs *argp = rqstp->rq_argp;
+	struct nfsd_diropres *resp = rqstp->rq_resp;
+
+	dprintk("nfsd: MKDIR    %s %.*s\n", SVCFH_fmt(&argp->fh), argp->len, argp->name);
+
+	if (resp->fh.fh_dentry) {
+		printk(KERN_WARNING
+			"nfsd_proc_mkdir: response already verified??\n");
+	}
+
+	argp->attrs.ia_valid &= ~ATTR_SIZE;
+	fh_init(&resp->fh, NFS_FHSIZE);
+	resp->status = nfsd_create(rqstp, &argp->fh, argp->name, argp->len,
+				   &argp->attrs, S_IFDIR, 0, &resp->fh);
+	fh_put(&argp->fh);
+	if (resp->status != nfs_ok)
+		goto out;
+
+	resp->status = fh_getattr(&resp->fh, &resp->stat);
+out:
+	return rpc_success;
+}
+
+/*
+ * Remove a directory
+ */
+static __be32
+nfsd_proc_rmdir(struct svc_rqst *rqstp)
+{
+	struct nfsd_diropargs *argp = rqstp->rq_argp;
+	struct nfsd_stat *resp = rqstp->rq_resp;
+
+	dprintk("nfsd: RMDIR    %s %.*s\n", SVCFH_fmt(&argp->fh), argp->len, argp->name);
+
+	resp->status = nfsd_unlink(rqstp, &argp->fh, S_IFDIR,
+				   argp->name, argp->len);
+	fh_put(&argp->fh);
+	return rpc_success;
+}
+
+/*
+ * Read a portion of a directory.
+ */
+static __be32
+nfsd_proc_readdir(struct svc_rqst *rqstp)
+{
+	struct nfsd_readdirargs *argp = rqstp->rq_argp;
+	struct nfsd_readdirres *resp = rqstp->rq_resp;
+	int		count;
+	loff_t		offset;
+
+	dprintk("nfsd: READDIR  %s %d bytes at %d\n",
+		SVCFH_fmt(&argp->fh),		
+		argp->count, argp->cookie);
+
+	/* Shrink to the client read size */
+	count = (argp->count >> 2) - 2;
+
+	/* Make sure we've room for the NULL ptr & eof flag */
+	count -= 2;
+	if (count < 0)
+		count = 0;
+
+	resp->buffer = argp->buffer;
+	resp->offset = NULL;
+	resp->buflen = count;
+	resp->common.err = nfs_ok;
+	/* Read directory and encode entries on the fly */
+	offset = argp->cookie;
+	resp->status = nfsd_readdir(rqstp, &argp->fh, &offset,
+				    &resp->common, nfssvc_encode_entry);
+
+	resp->count = resp->buffer - argp->buffer;
+	if (resp->offset)
+		*resp->offset = htonl(offset);
+
+	fh_put(&argp->fh);
+	return rpc_success;
+}
+
+/*
+ * Get file system info
+ */
+static __be32
+nfsd_proc_statfs(struct svc_rqst *rqstp)
+{
+	struct nfsd_fhandle *argp = rqstp->rq_argp;
+	struct nfsd_statfsres *resp = rqstp->rq_resp;
+
+	dprintk("nfsd: STATFS   %s\n", SVCFH_fmt(&argp->fh));
+
+	resp->status = nfsd_statfs(rqstp, &argp->fh, &resp->stats,
+				   NFSD_MAY_BYPASS_GSS_ON_ROOT);
+	fh_put(&argp->fh);
+	return rpc_success;
+}
+
+/*
+ * NFSv2 Server procedures.
+ * Only the results of non-idempotent operations are cached.
+ */
+struct nfsd_void { int dummy; };
+
+#define ST 1		/* status */
+#define FH 8		/* filehandle */
+#define	AT 18		/* attributes */
+
+static const struct svc_procedure nfsd_procedures2[18] = {
+	[NFSPROC_NULL] = {
+		.pc_func = nfsd_proc_null,
+		.pc_decode = nfssvc_decode_void,
+		.pc_encode = nfssvc_encode_void,
+		.pc_argsize = sizeof(struct nfsd_void),
+		.pc_ressize = sizeof(struct nfsd_void),
+		.pc_cachetype = RC_NOCACHE,
+		.pc_xdrressize = 0,
+	},
+	[NFSPROC_GETATTR] = {
+		.pc_func = nfsd_proc_getattr,
+		.pc_decode = nfssvc_decode_fhandle,
+		.pc_encode = nfssvc_encode_attrstat,
+		.pc_release = nfssvc_release_attrstat,
+		.pc_argsize = sizeof(struct nfsd_fhandle),
+		.pc_ressize = sizeof(struct nfsd_attrstat),
+		.pc_cachetype = RC_NOCACHE,
+		.pc_xdrressize = ST+AT,
+	},
+	[NFSPROC_SETATTR] = {
+		.pc_func = nfsd_proc_setattr,
+		.pc_decode = nfssvc_decode_sattrargs,
+		.pc_encode = nfssvc_encode_attrstat,
+		.pc_release = nfssvc_release_attrstat,
+		.pc_argsize = sizeof(struct nfsd_sattrargs),
+		.pc_ressize = sizeof(struct nfsd_attrstat),
+		.pc_cachetype = RC_REPLBUFF,
+		.pc_xdrressize = ST+AT,
+	},
+	[NFSPROC_ROOT] = {
+		.pc_func = nfsd_proc_root,
+		.pc_decode = nfssvc_decode_void,
+		.pc_encode = nfssvc_encode_void,
+		.pc_argsize = sizeof(struct nfsd_void),
+		.pc_ressize = sizeof(struct nfsd_void),
+		.pc_cachetype = RC_NOCACHE,
+		.pc_xdrressize = 0,
+	},
+	[NFSPROC_LOOKUP] = {
+		.pc_func = nfsd_proc_lookup,
+		.pc_decode = nfssvc_decode_diropargs,
+		.pc_encode = nfssvc_encode_diropres,
+		.pc_release = nfssvc_release_diropres,
+		.pc_argsize = sizeof(struct nfsd_diropargs),
+		.pc_ressize = sizeof(struct nfsd_diropres),
+		.pc_cachetype = RC_NOCACHE,
+		.pc_xdrressize = ST+FH+AT,
+	},
+	[NFSPROC_READLINK] = {
+		.pc_func = nfsd_proc_readlink,
+		.pc_decode = nfssvc_decode_readlinkargs,
+		.pc_encode = nfssvc_encode_readlinkres,
+		.pc_argsize = sizeof(struct nfsd_readlinkargs),
+		.pc_ressize = sizeof(struct nfsd_readlinkres),
+		.pc_cachetype = RC_NOCACHE,
+		.pc_xdrressize = ST+1+NFS_MAXPATHLEN/4,
+	},
+	[NFSPROC_READ] = {
+		.pc_func = nfsd_proc_read,
+		.pc_decode = nfssvc_decode_readargs,
+		.pc_encode = nfssvc_encode_readres,
+		.pc_release = nfssvc_release_readres,
+		.pc_argsize = sizeof(struct nfsd_readargs),
+		.pc_ressize = sizeof(struct nfsd_readres),
+		.pc_cachetype = RC_NOCACHE,
+		.pc_xdrressize = ST+AT+1+NFSSVC_MAXBLKSIZE_V2/4,
+	},
+	[NFSPROC_WRITECACHE] = {
+		.pc_func = nfsd_proc_writecache,
+		.pc_decode = nfssvc_decode_void,
+		.pc_encode = nfssvc_encode_void,
+		.pc_argsize = sizeof(struct nfsd_void),
+		.pc_ressize = sizeof(struct nfsd_void),
+		.pc_cachetype = RC_NOCACHE,
+		.pc_xdrressize = 0,
+	},
+	[NFSPROC_WRITE] = {
+		.pc_func = nfsd_proc_write,
+		.pc_decode = nfssvc_decode_writeargs,
+		.pc_encode = nfssvc_encode_attrstat,
+		.pc_release = nfssvc_release_attrstat,
+		.pc_argsize = sizeof(struct nfsd_writeargs),
+		.pc_ressize = sizeof(struct nfsd_attrstat),
+		.pc_cachetype = RC_REPLBUFF,
+		.pc_xdrressize = ST+AT,
+	},
+	[NFSPROC_CREATE] = {
+		.pc_func = nfsd_proc_create,
+		.pc_decode = nfssvc_decode_createargs,
+		.pc_encode = nfssvc_encode_diropres,
+		.pc_release = nfssvc_release_diropres,
+		.pc_argsize = sizeof(struct nfsd_createargs),
+		.pc_ressize = sizeof(struct nfsd_diropres),
+		.pc_cachetype = RC_REPLBUFF,
+		.pc_xdrressize = ST+FH+AT,
+	},
+	[NFSPROC_REMOVE] = {
+		.pc_func = nfsd_proc_remove,
+		.pc_decode = nfssvc_decode_diropargs,
+		.pc_encode = nfssvc_encode_stat,
+		.pc_argsize = sizeof(struct nfsd_diropargs),
+		.pc_ressize = sizeof(struct nfsd_stat),
+		.pc_cachetype = RC_REPLSTAT,
+		.pc_xdrressize = ST,
+	},
+	[NFSPROC_RENAME] = {
+		.pc_func = nfsd_proc_rename,
+		.pc_decode = nfssvc_decode_renameargs,
+		.pc_encode = nfssvc_encode_stat,
+		.pc_argsize = sizeof(struct nfsd_renameargs),
+		.pc_ressize = sizeof(struct nfsd_stat),
+		.pc_cachetype = RC_REPLSTAT,
+		.pc_xdrressize = ST,
+	},
+	[NFSPROC_LINK] = {
+		.pc_func = nfsd_proc_link,
+		.pc_decode = nfssvc_decode_linkargs,
+		.pc_encode = nfssvc_encode_stat,
+		.pc_argsize = sizeof(struct nfsd_linkargs),
+		.pc_ressize = sizeof(struct nfsd_stat),
+		.pc_cachetype = RC_REPLSTAT,
+		.pc_xdrressize = ST,
+	},
+	[NFSPROC_SYMLINK] = {
+		.pc_func = nfsd_proc_symlink,
+		.pc_decode = nfssvc_decode_symlinkargs,
+		.pc_encode = nfssvc_encode_stat,
+		.pc_argsize = sizeof(struct nfsd_symlinkargs),
+		.pc_ressize = sizeof(struct nfsd_stat),
+		.pc_cachetype = RC_REPLSTAT,
+		.pc_xdrressize = ST,
+	},
+	[NFSPROC_MKDIR] = {
+		.pc_func = nfsd_proc_mkdir,
+		.pc_decode = nfssvc_decode_createargs,
+		.pc_encode = nfssvc_encode_diropres,
+		.pc_release = nfssvc_release_diropres,
+		.pc_argsize = sizeof(struct nfsd_createargs),
+		.pc_ressize = sizeof(struct nfsd_diropres),
+		.pc_cachetype = RC_REPLBUFF,
+		.pc_xdrressize = ST+FH+AT,
+	},
+	[NFSPROC_RMDIR] = {
+		.pc_func = nfsd_proc_rmdir,
+		.pc_decode = nfssvc_decode_diropargs,
+		.pc_encode = nfssvc_encode_stat,
+		.pc_argsize = sizeof(struct nfsd_diropargs),
+		.pc_ressize = sizeof(struct nfsd_stat),
+		.pc_cachetype = RC_REPLSTAT,
+		.pc_xdrressize = ST,
+	},
+	[NFSPROC_READDIR] = {
+		.pc_func = nfsd_proc_readdir,
+		.pc_decode = nfssvc_decode_readdirargs,
+		.pc_encode = nfssvc_encode_readdirres,
+		.pc_argsize = sizeof(struct nfsd_readdirargs),
+		.pc_ressize = sizeof(struct nfsd_readdirres),
+		.pc_cachetype = RC_NOCACHE,
+	},
+	[NFSPROC_STATFS] = {
+		.pc_func = nfsd_proc_statfs,
+		.pc_decode = nfssvc_decode_fhandle,
+		.pc_encode = nfssvc_encode_statfsres,
+		.pc_argsize = sizeof(struct nfsd_fhandle),
+		.pc_ressize = sizeof(struct nfsd_statfsres),
+		.pc_cachetype = RC_NOCACHE,
+		.pc_xdrressize = ST+5,
+	},
+};
+
+
+static unsigned int nfsd_count2[ARRAY_SIZE(nfsd_procedures2)];
+const struct svc_version nfsd_version2 = {
+	.vs_vers	= 2,
+	.vs_nproc	= 18,
+	.vs_proc	= nfsd_procedures2,
+	.vs_count	= nfsd_count2,
+	.vs_dispatch	= nfsd_dispatch,
+	.vs_xdrsize	= NFS2_SVC_XDRSIZE,
+};
+
+/*
+ * Map errnos to NFS errnos.
+ */
+__be32
+nfserrno (int errno)
+{
+	static struct {
+		__be32	nfserr;
+		int	syserr;
+	} nfs_errtbl[] = {
+		{ nfs_ok, 0 },
+		{ nfserr_perm, -EPERM },
+		{ nfserr_noent, -ENOENT },
+		{ nfserr_io, -EIO },
+		{ nfserr_nxio, -ENXIO },
+		{ nfserr_fbig, -E2BIG },
+		{ nfserr_acces, -EACCES },
+		{ nfserr_exist, -EEXIST },
+		{ nfserr_xdev, -EXDEV },
+		{ nfserr_mlink, -EMLINK },
+		{ nfserr_nodev, -ENODEV },
+		{ nfserr_notdir, -ENOTDIR },
+		{ nfserr_isdir, -EISDIR },
+		{ nfserr_inval, -EINVAL },
+		{ nfserr_fbig, -EFBIG },
+		{ nfserr_nospc, -ENOSPC },
+		{ nfserr_rofs, -EROFS },
+		{ nfserr_mlink, -EMLINK },
+		{ nfserr_nametoolong, -ENAMETOOLONG },
+		{ nfserr_notempty, -ENOTEMPTY },
+#ifdef EDQUOT
+		{ nfserr_dquot, -EDQUOT },
+#endif
+		{ nfserr_stale, -ESTALE },
+		{ nfserr_jukebox, -ETIMEDOUT },
+		{ nfserr_jukebox, -ERESTARTSYS },
+		{ nfserr_jukebox, -EAGAIN },
+		{ nfserr_jukebox, -EWOULDBLOCK },
+		{ nfserr_jukebox, -ENOMEM },
+		{ nfserr_io, -ETXTBSY },
+		{ nfserr_notsupp, -EOPNOTSUPP },
+		{ nfserr_toosmall, -ETOOSMALL },
+		{ nfserr_serverfault, -ESERVERFAULT },
+		{ nfserr_serverfault, -ENFILE },
+		{ nfserr_io, -EUCLEAN },
+		{ nfserr_perm, -ENOKEY },
+	};
+	int	i;
+
+	for (i = 0; i < ARRAY_SIZE(nfs_errtbl); i++) {
+		if (nfs_errtbl[i].syserr == errno)
+			return nfs_errtbl[i].nfserr;
+	}
+	WARN_ONCE(1, "nfsd: non-standard errno: %d\n", errno);
+	return nfserr_io;
+}
+
diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c
new file mode 100644
index 000000000..2e61a565c
--- /dev/null
+++ b/fs/nfsd/nfssvc.c
@@ -0,0 +1,1135 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Central processing for nfsd.
+ *
+ * Authors:	Olaf Kirch (okir@monad.swb.de)
+ *
+ * Copyright (C) 1995, 1996, 1997 Olaf Kirch <okir@monad.swb.de>
+ */
+
+#include <linux/sched/signal.h>
+#include <linux/freezer.h>
+#include <linux/module.h>
+#include <linux/fs_struct.h>
+#include <linux/swap.h>
+
+#include <linux/sunrpc/stats.h>
+#include <linux/sunrpc/svcsock.h>
+#include <linux/sunrpc/svc_xprt.h>
+#include <linux/lockd/bind.h>
+#include <linux/nfsacl.h>
+#include <linux/seq_file.h>
+#include <linux/inetdevice.h>
+#include <net/addrconf.h>
+#include <net/ipv6.h>
+#include <net/net_namespace.h>
+#include "nfsd.h"
+#include "cache.h"
+#include "vfs.h"
+#include "netns.h"
+#include "filecache.h"
+
+#define NFSDDBG_FACILITY	NFSDDBG_SVC
+
+bool inter_copy_offload_enable;
+EXPORT_SYMBOL_GPL(inter_copy_offload_enable);
+module_param(inter_copy_offload_enable, bool, 0644);
+MODULE_PARM_DESC(inter_copy_offload_enable,
+		 "Enable inter server to server copy offload. Default: false");
+
+extern struct svc_program	nfsd_program;
+static int			nfsd(void *vrqstp);
+#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
+static int			nfsd_acl_rpcbind_set(struct net *,
+						     const struct svc_program *,
+						     u32, int,
+						     unsigned short,
+						     unsigned short);
+static __be32			nfsd_acl_init_request(struct svc_rqst *,
+						const struct svc_program *,
+						struct svc_process_info *);
+#endif
+static int			nfsd_rpcbind_set(struct net *,
+						 const struct svc_program *,
+						 u32, int,
+						 unsigned short,
+						 unsigned short);
+static __be32			nfsd_init_request(struct svc_rqst *,
+						const struct svc_program *,
+						struct svc_process_info *);
+
+/*
+ * nfsd_mutex protects nn->nfsd_serv -- both the pointer itself and the members
+ * of the svc_serv struct. In particular, ->sv_nrthreads but also to some
+ * extent ->sv_temp_socks and ->sv_permsocks. It also protects nfsdstats.th_cnt
+ *
+ * If (out side the lock) nn->nfsd_serv is non-NULL, then it must point to a
+ * properly initialised 'struct svc_serv' with ->sv_nrthreads > 0. That number
+ * of nfsd threads must exist and each must listed in ->sp_all_threads in each
+ * entry of ->sv_pools[].
+ *
+ * Transitions of the thread count between zero and non-zero are of particular
+ * interest since the svc_serv needs to be created and initialized at that
+ * point, or freed.
+ *
+ * Finally, the nfsd_mutex also protects some of the global variables that are
+ * accessed when nfsd starts and that are settable via the write_* routines in
+ * nfsctl.c. In particular:
+ *
+ *	user_recovery_dirname
+ *	user_lease_time
+ *	nfsd_versions
+ */
+DEFINE_MUTEX(nfsd_mutex);
+
+/*
+ * nfsd_drc_lock protects nfsd_drc_max_pages and nfsd_drc_pages_used.
+ * nfsd_drc_max_pages limits the total amount of memory available for
+ * version 4.1 DRC caches.
+ * nfsd_drc_pages_used tracks the current version 4.1 DRC memory usage.
+ */
+spinlock_t	nfsd_drc_lock;
+unsigned long	nfsd_drc_max_mem;
+unsigned long	nfsd_drc_mem_used;
+
+#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
+static struct svc_stat	nfsd_acl_svcstats;
+static const struct svc_version *nfsd_acl_version[] = {
+	[2] = &nfsd_acl_version2,
+	[3] = &nfsd_acl_version3,
+};
+
+#define NFSD_ACL_MINVERS            2
+#define NFSD_ACL_NRVERS		ARRAY_SIZE(nfsd_acl_version)
+
+static struct svc_program	nfsd_acl_program = {
+	.pg_prog		= NFS_ACL_PROGRAM,
+	.pg_nvers		= NFSD_ACL_NRVERS,
+	.pg_vers		= nfsd_acl_version,
+	.pg_name		= "nfsacl",
+	.pg_class		= "nfsd",
+	.pg_stats		= &nfsd_acl_svcstats,
+	.pg_authenticate	= &svc_set_client,
+	.pg_init_request	= nfsd_acl_init_request,
+	.pg_rpcbind_set		= nfsd_acl_rpcbind_set,
+};
+
+static struct svc_stat	nfsd_acl_svcstats = {
+	.program	= &nfsd_acl_program,
+};
+#endif /* defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) */
+
+static const struct svc_version *nfsd_version[] = {
+	[2] = &nfsd_version2,
+#if defined(CONFIG_NFSD_V3)
+	[3] = &nfsd_version3,
+#endif
+#if defined(CONFIG_NFSD_V4)
+	[4] = &nfsd_version4,
+#endif
+};
+
+#define NFSD_MINVERS    	2
+#define NFSD_NRVERS		ARRAY_SIZE(nfsd_version)
+
+struct svc_program		nfsd_program = {
+#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
+	.pg_next		= &nfsd_acl_program,
+#endif
+	.pg_prog		= NFS_PROGRAM,		/* program number */
+	.pg_nvers		= NFSD_NRVERS,		/* nr of entries in nfsd_version */
+	.pg_vers		= nfsd_version,		/* version table */
+	.pg_name		= "nfsd",		/* program name */
+	.pg_class		= "nfsd",		/* authentication class */
+	.pg_stats		= &nfsd_svcstats,	/* version table */
+	.pg_authenticate	= &svc_set_client,	/* export authentication */
+	.pg_init_request	= nfsd_init_request,
+	.pg_rpcbind_set		= nfsd_rpcbind_set,
+};
+
+static bool
+nfsd_support_version(int vers)
+{
+	if (vers >= NFSD_MINVERS && vers < NFSD_NRVERS)
+		return nfsd_version[vers] != NULL;
+	return false;
+}
+
+static bool *
+nfsd_alloc_versions(void)
+{
+	bool *vers = kmalloc_array(NFSD_NRVERS, sizeof(bool), GFP_KERNEL);
+	unsigned i;
+
+	if (vers) {
+		/* All compiled versions are enabled by default */
+		for (i = 0; i < NFSD_NRVERS; i++)
+			vers[i] = nfsd_support_version(i);
+	}
+	return vers;
+}
+
+static bool *
+nfsd_alloc_minorversions(void)
+{
+	bool *vers = kmalloc_array(NFSD_SUPPORTED_MINOR_VERSION + 1,
+			sizeof(bool), GFP_KERNEL);
+	unsigned i;
+
+	if (vers) {
+		/* All minor versions are enabled by default */
+		for (i = 0; i <= NFSD_SUPPORTED_MINOR_VERSION; i++)
+			vers[i] = nfsd_support_version(4);
+	}
+	return vers;
+}
+
+void
+nfsd_netns_free_versions(struct nfsd_net *nn)
+{
+	kfree(nn->nfsd_versions);
+	kfree(nn->nfsd4_minorversions);
+	nn->nfsd_versions = NULL;
+	nn->nfsd4_minorversions = NULL;
+}
+
+static void
+nfsd_netns_init_versions(struct nfsd_net *nn)
+{
+	if (!nn->nfsd_versions) {
+		nn->nfsd_versions = nfsd_alloc_versions();
+		nn->nfsd4_minorversions = nfsd_alloc_minorversions();
+		if (!nn->nfsd_versions || !nn->nfsd4_minorversions)
+			nfsd_netns_free_versions(nn);
+	}
+}
+
+int nfsd_vers(struct nfsd_net *nn, int vers, enum vers_op change)
+{
+	if (vers < NFSD_MINVERS || vers >= NFSD_NRVERS)
+		return 0;
+	switch(change) {
+	case NFSD_SET:
+		if (nn->nfsd_versions)
+			nn->nfsd_versions[vers] = nfsd_support_version(vers);
+		break;
+	case NFSD_CLEAR:
+		nfsd_netns_init_versions(nn);
+		if (nn->nfsd_versions)
+			nn->nfsd_versions[vers] = false;
+		break;
+	case NFSD_TEST:
+		if (nn->nfsd_versions)
+			return nn->nfsd_versions[vers];
+		fallthrough;
+	case NFSD_AVAIL:
+		return nfsd_support_version(vers);
+	}
+	return 0;
+}
+
+static void
+nfsd_adjust_nfsd_versions4(struct nfsd_net *nn)
+{
+	unsigned i;
+
+	for (i = 0; i <= NFSD_SUPPORTED_MINOR_VERSION; i++) {
+		if (nn->nfsd4_minorversions[i])
+			return;
+	}
+	nfsd_vers(nn, 4, NFSD_CLEAR);
+}
+
+int nfsd_minorversion(struct nfsd_net *nn, u32 minorversion, enum vers_op change)
+{
+	if (minorversion > NFSD_SUPPORTED_MINOR_VERSION &&
+	    change != NFSD_AVAIL)
+		return -1;
+
+	switch(change) {
+	case NFSD_SET:
+		if (nn->nfsd4_minorversions) {
+			nfsd_vers(nn, 4, NFSD_SET);
+			nn->nfsd4_minorversions[minorversion] =
+				nfsd_vers(nn, 4, NFSD_TEST);
+		}
+		break;
+	case NFSD_CLEAR:
+		nfsd_netns_init_versions(nn);
+		if (nn->nfsd4_minorversions) {
+			nn->nfsd4_minorversions[minorversion] = false;
+			nfsd_adjust_nfsd_versions4(nn);
+		}
+		break;
+	case NFSD_TEST:
+		if (nn->nfsd4_minorversions)
+			return nn->nfsd4_minorversions[minorversion];
+		return nfsd_vers(nn, 4, NFSD_TEST);
+	case NFSD_AVAIL:
+		return minorversion <= NFSD_SUPPORTED_MINOR_VERSION &&
+			nfsd_vers(nn, 4, NFSD_AVAIL);
+	}
+	return 0;
+}
+
+/*
+ * Maximum number of nfsd processes
+ */
+#define	NFSD_MAXSERVS		8192
+
+int nfsd_nrthreads(struct net *net)
+{
+	int rv = 0;
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	mutex_lock(&nfsd_mutex);
+	if (nn->nfsd_serv)
+		rv = nn->nfsd_serv->sv_nrthreads;
+	mutex_unlock(&nfsd_mutex);
+	return rv;
+}
+
+static int nfsd_init_socks(struct net *net, const struct cred *cred)
+{
+	int error;
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	if (!list_empty(&nn->nfsd_serv->sv_permsocks))
+		return 0;
+
+	error = svc_create_xprt(nn->nfsd_serv, "udp", net, PF_INET, NFS_PORT,
+					SVC_SOCK_DEFAULTS, cred);
+	if (error < 0)
+		return error;
+
+	error = svc_create_xprt(nn->nfsd_serv, "tcp", net, PF_INET, NFS_PORT,
+					SVC_SOCK_DEFAULTS, cred);
+	if (error < 0)
+		return error;
+
+	return 0;
+}
+
+static int nfsd_users = 0;
+
+static int nfsd_startup_generic(int nrservs)
+{
+	int ret;
+
+	if (nfsd_users++)
+		return 0;
+
+	ret = nfsd_file_cache_init();
+	if (ret)
+		goto dec_users;
+
+	ret = nfs4_state_start();
+	if (ret)
+		goto out_file_cache;
+	return 0;
+
+out_file_cache:
+	nfsd_file_cache_shutdown();
+dec_users:
+	nfsd_users--;
+	return ret;
+}
+
+static void nfsd_shutdown_generic(void)
+{
+	if (--nfsd_users)
+		return;
+
+	nfs4_state_shutdown();
+	nfsd_file_cache_shutdown();
+}
+
+static bool nfsd_needs_lockd(struct nfsd_net *nn)
+{
+	return nfsd_vers(nn, 2, NFSD_TEST) || nfsd_vers(nn, 3, NFSD_TEST);
+}
+
+void nfsd_copy_boot_verifier(__be32 verf[2], struct nfsd_net *nn)
+{
+	int seq = 0;
+
+	do {
+		read_seqbegin_or_lock(&nn->boot_lock, &seq);
+		/*
+		 * This is opaque to client, so no need to byte-swap. Use
+		 * __force to keep sparse happy. y2038 time_t overflow is
+		 * irrelevant in this usage
+		 */
+		verf[0] = (__force __be32)nn->nfssvc_boot.tv_sec;
+		verf[1] = (__force __be32)nn->nfssvc_boot.tv_nsec;
+	} while (need_seqretry(&nn->boot_lock, seq));
+	done_seqretry(&nn->boot_lock, seq);
+}
+
+static void nfsd_reset_boot_verifier_locked(struct nfsd_net *nn)
+{
+	ktime_get_real_ts64(&nn->nfssvc_boot);
+}
+
+void nfsd_reset_boot_verifier(struct nfsd_net *nn)
+{
+	write_seqlock(&nn->boot_lock);
+	nfsd_reset_boot_verifier_locked(nn);
+	write_sequnlock(&nn->boot_lock);
+}
+
+static int nfsd_startup_net(int nrservs, struct net *net, const struct cred *cred)
+{
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+	int ret;
+
+	if (nn->nfsd_net_up)
+		return 0;
+
+	ret = nfsd_startup_generic(nrservs);
+	if (ret)
+		return ret;
+	ret = nfsd_init_socks(net, cred);
+	if (ret)
+		goto out_socks;
+
+	if (nfsd_needs_lockd(nn) && !nn->lockd_up) {
+		ret = lockd_up(net, cred);
+		if (ret)
+			goto out_socks;
+		nn->lockd_up = true;
+	}
+
+	ret = nfsd_file_cache_start_net(net);
+	if (ret)
+		goto out_lockd;
+	ret = nfs4_state_start_net(net);
+	if (ret)
+		goto out_filecache;
+
+	nn->nfsd_net_up = true;
+	return 0;
+
+out_filecache:
+	nfsd_file_cache_shutdown_net(net);
+out_lockd:
+	if (nn->lockd_up) {
+		lockd_down(net);
+		nn->lockd_up = false;
+	}
+out_socks:
+	nfsd_shutdown_generic();
+	return ret;
+}
+
+static void nfsd_shutdown_net(struct net *net)
+{
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	nfs4_state_shutdown_net(net);
+	nfsd_file_cache_shutdown_net(net);
+	if (nn->lockd_up) {
+		lockd_down(net);
+		nn->lockd_up = false;
+	}
+	nn->nfsd_net_up = false;
+	nfsd_shutdown_generic();
+}
+
+static int nfsd_inetaddr_event(struct notifier_block *this, unsigned long event,
+	void *ptr)
+{
+	struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
+	struct net_device *dev = ifa->ifa_dev->dev;
+	struct net *net = dev_net(dev);
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+	struct sockaddr_in sin;
+
+	if ((event != NETDEV_DOWN) ||
+	    !atomic_inc_not_zero(&nn->ntf_refcnt))
+		goto out;
+
+	if (nn->nfsd_serv) {
+		dprintk("nfsd_inetaddr_event: removed %pI4\n", &ifa->ifa_local);
+		sin.sin_family = AF_INET;
+		sin.sin_addr.s_addr = ifa->ifa_local;
+		svc_age_temp_xprts_now(nn->nfsd_serv, (struct sockaddr *)&sin);
+	}
+	atomic_dec(&nn->ntf_refcnt);
+	wake_up(&nn->ntf_wq);
+
+out:
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block nfsd_inetaddr_notifier = {
+	.notifier_call = nfsd_inetaddr_event,
+};
+
+#if IS_ENABLED(CONFIG_IPV6)
+static int nfsd_inet6addr_event(struct notifier_block *this,
+	unsigned long event, void *ptr)
+{
+	struct inet6_ifaddr *ifa = (struct inet6_ifaddr *)ptr;
+	struct net_device *dev = ifa->idev->dev;
+	struct net *net = dev_net(dev);
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+	struct sockaddr_in6 sin6;
+
+	if ((event != NETDEV_DOWN) ||
+	    !atomic_inc_not_zero(&nn->ntf_refcnt))
+		goto out;
+
+	if (nn->nfsd_serv) {
+		dprintk("nfsd_inet6addr_event: removed %pI6\n", &ifa->addr);
+		sin6.sin6_family = AF_INET6;
+		sin6.sin6_addr = ifa->addr;
+		if (ipv6_addr_type(&sin6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
+			sin6.sin6_scope_id = ifa->idev->dev->ifindex;
+		svc_age_temp_xprts_now(nn->nfsd_serv, (struct sockaddr *)&sin6);
+	}
+	atomic_dec(&nn->ntf_refcnt);
+	wake_up(&nn->ntf_wq);
+out:
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block nfsd_inet6addr_notifier = {
+	.notifier_call = nfsd_inet6addr_event,
+};
+#endif
+
+/* Only used under nfsd_mutex, so this atomic may be overkill: */
+static atomic_t nfsd_notifier_refcount = ATOMIC_INIT(0);
+
+static void nfsd_last_thread(struct svc_serv *serv, struct net *net)
+{
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	atomic_dec(&nn->ntf_refcnt);
+	/* check if the notifier still has clients */
+	if (atomic_dec_return(&nfsd_notifier_refcount) == 0) {
+		unregister_inetaddr_notifier(&nfsd_inetaddr_notifier);
+#if IS_ENABLED(CONFIG_IPV6)
+		unregister_inet6addr_notifier(&nfsd_inet6addr_notifier);
+#endif
+	}
+	wait_event(nn->ntf_wq, atomic_read(&nn->ntf_refcnt) == 0);
+
+	/*
+	 * write_ports can create the server without actually starting
+	 * any threads--if we get shut down before any threads are
+	 * started, then nfsd_last_thread will be run before any of this
+	 * other initialization has been done except the rpcb information.
+	 */
+	svc_rpcb_cleanup(serv, net);
+	if (!nn->nfsd_net_up)
+		return;
+
+	nfsd_shutdown_net(net);
+	pr_info("nfsd: last server has exited, flushing export cache\n");
+	nfsd_export_flush(net);
+}
+
+void nfsd_reset_versions(struct nfsd_net *nn)
+{
+	int i;
+
+	for (i = 0; i < NFSD_NRVERS; i++)
+		if (nfsd_vers(nn, i, NFSD_TEST))
+			return;
+
+	for (i = 0; i < NFSD_NRVERS; i++)
+		if (i != 4)
+			nfsd_vers(nn, i, NFSD_SET);
+		else {
+			int minor = 0;
+			while (nfsd_minorversion(nn, minor, NFSD_SET) >= 0)
+				minor++;
+		}
+}
+
+/*
+ * Each session guarantees a negotiated per slot memory cache for replies
+ * which in turn consumes memory beyond the v2/v3/v4.0 server. A dedicated
+ * NFSv4.1 server might want to use more memory for a DRC than a machine
+ * with mutiple services.
+ *
+ * Impose a hard limit on the number of pages for the DRC which varies
+ * according to the machines free pages. This is of course only a default.
+ *
+ * For now this is a #defined shift which could be under admin control
+ * in the future.
+ */
+static void set_max_drc(void)
+{
+	#define NFSD_DRC_SIZE_SHIFT	7
+	nfsd_drc_max_mem = (nr_free_buffer_pages()
+					>> NFSD_DRC_SIZE_SHIFT) * PAGE_SIZE;
+	nfsd_drc_mem_used = 0;
+	spin_lock_init(&nfsd_drc_lock);
+	dprintk("%s nfsd_drc_max_mem %lu \n", __func__, nfsd_drc_max_mem);
+}
+
+static int nfsd_get_default_max_blksize(void)
+{
+	struct sysinfo i;
+	unsigned long long target;
+	unsigned long ret;
+
+	si_meminfo(&i);
+	target = (i.totalram - i.totalhigh) << PAGE_SHIFT;
+	/*
+	 * Aim for 1/4096 of memory per thread This gives 1MB on 4Gig
+	 * machines, but only uses 32K on 128M machines.  Bottom out at
+	 * 8K on 32M and smaller.  Of course, this is only a default.
+	 */
+	target >>= 12;
+
+	ret = NFSSVC_MAXBLKSIZE;
+	while (ret > target && ret >= 8*1024*2)
+		ret /= 2;
+	return ret;
+}
+
+static const struct svc_serv_ops nfsd_thread_sv_ops = {
+	.svo_shutdown		= nfsd_last_thread,
+	.svo_function		= nfsd,
+	.svo_enqueue_xprt	= svc_xprt_do_enqueue,
+	.svo_setup		= svc_set_num_threads,
+	.svo_module		= THIS_MODULE,
+};
+
+static void nfsd_complete_shutdown(struct net *net)
+{
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	WARN_ON(!mutex_is_locked(&nfsd_mutex));
+
+	nn->nfsd_serv = NULL;
+	complete(&nn->nfsd_shutdown_complete);
+}
+
+void nfsd_shutdown_threads(struct net *net)
+{
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+	struct svc_serv *serv;
+
+	mutex_lock(&nfsd_mutex);
+	serv = nn->nfsd_serv;
+	if (serv == NULL) {
+		mutex_unlock(&nfsd_mutex);
+		return;
+	}
+
+	svc_get(serv);
+	/* Kill outstanding nfsd threads */
+	serv->sv_ops->svo_setup(serv, NULL, 0);
+	nfsd_destroy(net);
+	mutex_unlock(&nfsd_mutex);
+	/* Wait for shutdown of nfsd_serv to complete */
+	wait_for_completion(&nn->nfsd_shutdown_complete);
+}
+
+bool i_am_nfsd(void)
+{
+	return kthread_func(current) == nfsd;
+}
+
+int nfsd_create_serv(struct net *net)
+{
+	int error;
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	WARN_ON(!mutex_is_locked(&nfsd_mutex));
+	if (nn->nfsd_serv) {
+		svc_get(nn->nfsd_serv);
+		return 0;
+	}
+	if (nfsd_max_blksize == 0)
+		nfsd_max_blksize = nfsd_get_default_max_blksize();
+	nfsd_reset_versions(nn);
+	nn->nfsd_serv = svc_create_pooled(&nfsd_program, nfsd_max_blksize,
+						&nfsd_thread_sv_ops);
+	if (nn->nfsd_serv == NULL)
+		return -ENOMEM;
+	init_completion(&nn->nfsd_shutdown_complete);
+
+	nn->nfsd_serv->sv_maxconn = nn->max_connections;
+	error = svc_bind(nn->nfsd_serv, net);
+	if (error < 0) {
+		svc_destroy(nn->nfsd_serv);
+		nfsd_complete_shutdown(net);
+		return error;
+	}
+
+	set_max_drc();
+	/* check if the notifier is already set */
+	if (atomic_inc_return(&nfsd_notifier_refcount) == 1) {
+		register_inetaddr_notifier(&nfsd_inetaddr_notifier);
+#if IS_ENABLED(CONFIG_IPV6)
+		register_inet6addr_notifier(&nfsd_inet6addr_notifier);
+#endif
+	}
+	atomic_inc(&nn->ntf_refcnt);
+	nfsd_reset_boot_verifier(nn);
+	return 0;
+}
+
+int nfsd_nrpools(struct net *net)
+{
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	if (nn->nfsd_serv == NULL)
+		return 0;
+	else
+		return nn->nfsd_serv->sv_nrpools;
+}
+
+int nfsd_get_nrthreads(int n, int *nthreads, struct net *net)
+{
+	int i = 0;
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	if (nn->nfsd_serv != NULL) {
+		for (i = 0; i < nn->nfsd_serv->sv_nrpools && i < n; i++)
+			nthreads[i] = nn->nfsd_serv->sv_pools[i].sp_nrthreads;
+	}
+
+	return 0;
+}
+
+void nfsd_destroy(struct net *net)
+{
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+	int destroy = (nn->nfsd_serv->sv_nrthreads == 1);
+
+	if (destroy)
+		svc_shutdown_net(nn->nfsd_serv, net);
+	svc_destroy(nn->nfsd_serv);
+	if (destroy)
+		nfsd_complete_shutdown(net);
+}
+
+int nfsd_set_nrthreads(int n, int *nthreads, struct net *net)
+{
+	int i = 0;
+	int tot = 0;
+	int err = 0;
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	WARN_ON(!mutex_is_locked(&nfsd_mutex));
+
+	if (nn->nfsd_serv == NULL || n <= 0)
+		return 0;
+
+	if (n > nn->nfsd_serv->sv_nrpools)
+		n = nn->nfsd_serv->sv_nrpools;
+
+	/* enforce a global maximum number of threads */
+	tot = 0;
+	for (i = 0; i < n; i++) {
+		nthreads[i] = min(nthreads[i], NFSD_MAXSERVS);
+		tot += nthreads[i];
+	}
+	if (tot > NFSD_MAXSERVS) {
+		/* total too large: scale down requested numbers */
+		for (i = 0; i < n && tot > 0; i++) {
+		    	int new = nthreads[i] * NFSD_MAXSERVS / tot;
+			tot -= (nthreads[i] - new);
+			nthreads[i] = new;
+		}
+		for (i = 0; i < n && tot > 0; i++) {
+			nthreads[i]--;
+			tot--;
+		}
+	}
+
+	/*
+	 * There must always be a thread in pool 0; the admin
+	 * can't shut down NFS completely using pool_threads.
+	 */
+	if (nthreads[0] == 0)
+		nthreads[0] = 1;
+
+	/* apply the new numbers */
+	svc_get(nn->nfsd_serv);
+	for (i = 0; i < n; i++) {
+		err = nn->nfsd_serv->sv_ops->svo_setup(nn->nfsd_serv,
+				&nn->nfsd_serv->sv_pools[i], nthreads[i]);
+		if (err)
+			break;
+	}
+	nfsd_destroy(net);
+	return err;
+}
+
+/*
+ * Adjust the number of threads and return the new number of threads.
+ * This is also the function that starts the server if necessary, if
+ * this is the first time nrservs is nonzero.
+ */
+int
+nfsd_svc(int nrservs, struct net *net, const struct cred *cred)
+{
+	int	error;
+	bool	nfsd_up_before;
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+
+	mutex_lock(&nfsd_mutex);
+	dprintk("nfsd: creating service\n");
+
+	nrservs = max(nrservs, 0);
+	nrservs = min(nrservs, NFSD_MAXSERVS);
+	error = 0;
+
+	if (nrservs == 0 && nn->nfsd_serv == NULL)
+		goto out;
+
+	strlcpy(nn->nfsd_name, utsname()->nodename,
+		sizeof(nn->nfsd_name));
+
+	error = nfsd_create_serv(net);
+	if (error)
+		goto out;
+
+	nfsd_up_before = nn->nfsd_net_up;
+
+	error = nfsd_startup_net(nrservs, net, cred);
+	if (error)
+		goto out_destroy;
+	error = nn->nfsd_serv->sv_ops->svo_setup(nn->nfsd_serv,
+			NULL, nrservs);
+	if (error)
+		goto out_shutdown;
+	/* We are holding a reference to nn->nfsd_serv which
+	 * we don't want to count in the return value,
+	 * so subtract 1
+	 */
+	error = nn->nfsd_serv->sv_nrthreads - 1;
+out_shutdown:
+	if (error < 0 && !nfsd_up_before)
+		nfsd_shutdown_net(net);
+out_destroy:
+	nfsd_destroy(net);		/* Release server */
+out:
+	mutex_unlock(&nfsd_mutex);
+	return error;
+}
+
+#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
+static bool
+nfsd_support_acl_version(int vers)
+{
+	if (vers >= NFSD_ACL_MINVERS && vers < NFSD_ACL_NRVERS)
+		return nfsd_acl_version[vers] != NULL;
+	return false;
+}
+
+static int
+nfsd_acl_rpcbind_set(struct net *net, const struct svc_program *progp,
+		     u32 version, int family, unsigned short proto,
+		     unsigned short port)
+{
+	if (!nfsd_support_acl_version(version) ||
+	    !nfsd_vers(net_generic(net, nfsd_net_id), version, NFSD_TEST))
+		return 0;
+	return svc_generic_rpcbind_set(net, progp, version, family,
+			proto, port);
+}
+
+static __be32
+nfsd_acl_init_request(struct svc_rqst *rqstp,
+		      const struct svc_program *progp,
+		      struct svc_process_info *ret)
+{
+	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+	int i;
+
+	if (likely(nfsd_support_acl_version(rqstp->rq_vers) &&
+	    nfsd_vers(nn, rqstp->rq_vers, NFSD_TEST)))
+		return svc_generic_init_request(rqstp, progp, ret);
+
+	ret->mismatch.lovers = NFSD_ACL_NRVERS;
+	for (i = NFSD_ACL_MINVERS; i < NFSD_ACL_NRVERS; i++) {
+		if (nfsd_support_acl_version(rqstp->rq_vers) &&
+		    nfsd_vers(nn, i, NFSD_TEST)) {
+			ret->mismatch.lovers = i;
+			break;
+		}
+	}
+	if (ret->mismatch.lovers == NFSD_ACL_NRVERS)
+		return rpc_prog_unavail;
+	ret->mismatch.hivers = NFSD_ACL_MINVERS;
+	for (i = NFSD_ACL_NRVERS - 1; i >= NFSD_ACL_MINVERS; i--) {
+		if (nfsd_support_acl_version(rqstp->rq_vers) &&
+		    nfsd_vers(nn, i, NFSD_TEST)) {
+			ret->mismatch.hivers = i;
+			break;
+		}
+	}
+	return rpc_prog_mismatch;
+}
+#endif
+
+static int
+nfsd_rpcbind_set(struct net *net, const struct svc_program *progp,
+		 u32 version, int family, unsigned short proto,
+		 unsigned short port)
+{
+	if (!nfsd_vers(net_generic(net, nfsd_net_id), version, NFSD_TEST))
+		return 0;
+	return svc_generic_rpcbind_set(net, progp, version, family,
+			proto, port);
+}
+
+static __be32
+nfsd_init_request(struct svc_rqst *rqstp,
+		  const struct svc_program *progp,
+		  struct svc_process_info *ret)
+{
+	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+	int i;
+
+	if (likely(nfsd_vers(nn, rqstp->rq_vers, NFSD_TEST)))
+		return svc_generic_init_request(rqstp, progp, ret);
+
+	ret->mismatch.lovers = NFSD_NRVERS;
+	for (i = NFSD_MINVERS; i < NFSD_NRVERS; i++) {
+		if (nfsd_vers(nn, i, NFSD_TEST)) {
+			ret->mismatch.lovers = i;
+			break;
+		}
+	}
+	if (ret->mismatch.lovers == NFSD_NRVERS)
+		return rpc_prog_unavail;
+	ret->mismatch.hivers = NFSD_MINVERS;
+	for (i = NFSD_NRVERS - 1; i >= NFSD_MINVERS; i--) {
+		if (nfsd_vers(nn, i, NFSD_TEST)) {
+			ret->mismatch.hivers = i;
+			break;
+		}
+	}
+	return rpc_prog_mismatch;
+}
+
+/*
+ * This is the NFS server kernel thread
+ */
+static int
+nfsd(void *vrqstp)
+{
+	struct svc_rqst *rqstp = (struct svc_rqst *) vrqstp;
+	struct svc_xprt *perm_sock = list_entry(rqstp->rq_server->sv_permsocks.next, typeof(struct svc_xprt), xpt_list);
+	struct net *net = perm_sock->xpt_net;
+	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+	int err;
+
+	/* Lock module and set up kernel thread */
+	mutex_lock(&nfsd_mutex);
+
+	/* At this point, the thread shares current->fs
+	 * with the init process. We need to create files with the
+	 * umask as defined by the client instead of init's umask. */
+	if (unshare_fs_struct() < 0) {
+		printk("Unable to start nfsd thread: out of memory\n");
+		goto out;
+	}
+
+	current->fs->umask = 0;
+
+	/*
+	 * thread is spawned with all signals set to SIG_IGN, re-enable
+	 * the ones that will bring down the thread
+	 */
+	allow_signal(SIGKILL);
+	allow_signal(SIGHUP);
+	allow_signal(SIGINT);
+	allow_signal(SIGQUIT);
+
+	nfsdstats.th_cnt++;
+	mutex_unlock(&nfsd_mutex);
+
+	set_freezable();
+
+	/*
+	 * The main request loop
+	 */
+	for (;;) {
+		/* Update sv_maxconn if it has changed */
+		rqstp->rq_server->sv_maxconn = nn->max_connections;
+
+		/*
+		 * Find a socket with data available and call its
+		 * recvfrom routine.
+		 */
+		while ((err = svc_recv(rqstp, 60*60*HZ)) == -EAGAIN)
+			;
+		if (err == -EINTR)
+			break;
+		validate_process_creds();
+		svc_process(rqstp);
+		validate_process_creds();
+	}
+
+	/* Clear signals before calling svc_exit_thread() */
+	flush_signals(current);
+
+	mutex_lock(&nfsd_mutex);
+	nfsdstats.th_cnt --;
+
+out:
+	rqstp->rq_server = NULL;
+
+	/* Release the thread */
+	svc_exit_thread(rqstp);
+
+	nfsd_destroy(net);
+
+	/* Release module */
+	mutex_unlock(&nfsd_mutex);
+	module_put_and_exit(0);
+	return 0;
+}
+
+/*
+ * A write procedure can have a large argument, and a read procedure can
+ * have a large reply, but no NFSv2 or NFSv3 procedure has argument and
+ * reply that can both be larger than a page.  The xdr code has taken
+ * advantage of this assumption to be a sloppy about bounds checking in
+ * some cases.  Pending a rewrite of the NFSv2/v3 xdr code to fix that
+ * problem, we enforce these assumptions here:
+ */
+static bool nfs_request_too_big(struct svc_rqst *rqstp,
+				const struct svc_procedure *proc)
+{
+	/*
+	 * The ACL code has more careful bounds-checking and is not
+	 * susceptible to this problem:
+	 */
+	if (rqstp->rq_prog != NFS_PROGRAM)
+		return false;
+	/*
+	 * Ditto NFSv4 (which can in theory have argument and reply both
+	 * more than a page):
+	 */
+	if (rqstp->rq_vers >= 4)
+		return false;
+	/* The reply will be small, we're OK: */
+	if (proc->pc_xdrressize > 0 &&
+	    proc->pc_xdrressize < XDR_QUADLEN(PAGE_SIZE))
+		return false;
+
+	return rqstp->rq_arg.len > PAGE_SIZE;
+}
+
+/**
+ * nfsd_dispatch - Process an NFS or NFSACL Request
+ * @rqstp: incoming request
+ * @statp: pointer to location of accept_stat field in RPC Reply buffer
+ *
+ * This RPC dispatcher integrates the NFS server's duplicate reply cache.
+ *
+ * Return values:
+ *  %0: Processing complete; do not send a Reply
+ *  %1: Processing complete; send Reply in rqstp->rq_res
+ */
+int nfsd_dispatch(struct svc_rqst *rqstp, __be32 *statp)
+{
+	const struct svc_procedure *proc = rqstp->rq_procinfo;
+	struct kvec *argv = &rqstp->rq_arg.head[0];
+	struct kvec *resv = &rqstp->rq_res.head[0];
+	__be32 *p;
+
+	dprintk("nfsd_dispatch: vers %d proc %d\n",
+				rqstp->rq_vers, rqstp->rq_proc);
+
+	if (nfs_request_too_big(rqstp, proc))
+		goto out_too_large;
+
+	/*
+	 * Give the xdr decoder a chance to change this if it wants
+	 * (necessary in the NFSv4.0 compound case)
+	 */
+	rqstp->rq_cachetype = proc->pc_cachetype;
+	if (!proc->pc_decode(rqstp, argv->iov_base))
+		goto out_decode_err;
+
+	switch (nfsd_cache_lookup(rqstp)) {
+	case RC_DOIT:
+		break;
+	case RC_REPLY:
+		goto out_cached_reply;
+	case RC_DROPIT:
+		goto out_dropit;
+	}
+
+	/*
+	 * Need to grab the location to store the status, as
+	 * NFSv4 does some encoding while processing
+	 */
+	p = resv->iov_base + resv->iov_len;
+	resv->iov_len += sizeof(__be32);
+
+	*statp = proc->pc_func(rqstp);
+	if (*statp == rpc_drop_reply || test_bit(RQ_DROPME, &rqstp->rq_flags))
+		goto out_update_drop;
+
+	if (!proc->pc_encode(rqstp, p))
+		goto out_encode_err;
+
+	nfsd_cache_update(rqstp, rqstp->rq_cachetype, statp + 1);
+out_cached_reply:
+	return 1;
+
+out_too_large:
+	dprintk("nfsd: NFSv%d argument too large\n", rqstp->rq_vers);
+	*statp = rpc_garbage_args;
+	return 1;
+
+out_decode_err:
+	dprintk("nfsd: failed to decode arguments!\n");
+	*statp = rpc_garbage_args;
+	return 1;
+
+out_update_drop:
+	dprintk("nfsd: Dropping request; may be revisited later\n");
+	nfsd_cache_update(rqstp, RC_NOCACHE, NULL);
+out_dropit:
+	return 0;
+
+out_encode_err:
+	dprintk("nfsd: failed to encode result!\n");
+	nfsd_cache_update(rqstp, RC_NOCACHE, NULL);
+	*statp = rpc_system_err;
+	return 1;
+}
+
+int nfsd_pool_stats_open(struct inode *inode, struct file *file)
+{
+	int ret;
+	struct nfsd_net *nn = net_generic(inode->i_sb->s_fs_info, nfsd_net_id);
+
+	mutex_lock(&nfsd_mutex);
+	if (nn->nfsd_serv == NULL) {
+		mutex_unlock(&nfsd_mutex);
+		return -ENODEV;
+	}
+	/* bump up the psudo refcount while traversing */
+	svc_get(nn->nfsd_serv);
+	ret = svc_pool_stats_open(nn->nfsd_serv, file);
+	mutex_unlock(&nfsd_mutex);
+	return ret;
+}
+
+int nfsd_pool_stats_release(struct inode *inode, struct file *file)
+{
+	int ret = seq_release(inode, file);
+	struct net *net = inode->i_sb->s_fs_info;
+
+	mutex_lock(&nfsd_mutex);
+	/* this function really, really should have been called svc_put() */
+	nfsd_destroy(net);
+	mutex_unlock(&nfsd_mutex);
+	return ret;
+}
diff --git a/fs/nfsd/nfsxdr.c b/fs/nfsd/nfsxdr.c
new file mode 100644
index 000000000..8a288c8fc
--- /dev/null
+++ b/fs/nfsd/nfsxdr.c
@@ -0,0 +1,616 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * XDR support for nfsd
+ *
+ * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
+ */
+
+#include "vfs.h"
+#include "xdr.h"
+#include "auth.h"
+
+#define NFSDDBG_FACILITY		NFSDDBG_XDR
+
+/*
+ * Mapping of S_IF* types to NFS file types
+ */
+static u32	nfs_ftypes[] = {
+	NFNON,  NFCHR,  NFCHR, NFBAD,
+	NFDIR,  NFBAD,  NFBLK, NFBAD,
+	NFREG,  NFBAD,  NFLNK, NFBAD,
+	NFSOCK, NFBAD,  NFLNK, NFBAD,
+};
+
+
+/*
+ * XDR functions for basic NFS types
+ */
+static __be32 *
+decode_fh(__be32 *p, struct svc_fh *fhp)
+{
+	fh_init(fhp, NFS_FHSIZE);
+	memcpy(&fhp->fh_handle.fh_base, p, NFS_FHSIZE);
+	fhp->fh_handle.fh_size = NFS_FHSIZE;
+
+	/* FIXME: Look up export pointer here and verify
+	 * Sun Secure RPC if requested */
+	return p + (NFS_FHSIZE >> 2);
+}
+
+/* Helper function for NFSv2 ACL code */
+__be32 *nfs2svc_decode_fh(__be32 *p, struct svc_fh *fhp)
+{
+	return decode_fh(p, fhp);
+}
+
+static __be32 *
+encode_fh(__be32 *p, struct svc_fh *fhp)
+{
+	memcpy(p, &fhp->fh_handle.fh_base, NFS_FHSIZE);
+	return p + (NFS_FHSIZE>> 2);
+}
+
+/*
+ * Decode a file name and make sure that the path contains
+ * no slashes or null bytes.
+ */
+static __be32 *
+decode_filename(__be32 *p, char **namp, unsigned int *lenp)
+{
+	char		*name;
+	unsigned int	i;
+
+	if ((p = xdr_decode_string_inplace(p, namp, lenp, NFS_MAXNAMLEN)) != NULL) {
+		for (i = 0, name = *namp; i < *lenp; i++, name++) {
+			if (*name == '\0' || *name == '/')
+				return NULL;
+		}
+	}
+
+	return p;
+}
+
+static __be32 *
+decode_sattr(__be32 *p, struct iattr *iap, struct user_namespace *userns)
+{
+	u32	tmp, tmp1;
+
+	iap->ia_valid = 0;
+
+	/* Sun client bug compatibility check: some sun clients seem to
+	 * put 0xffff in the mode field when they mean 0xffffffff.
+	 * Quoting the 4.4BSD nfs server code: Nah nah nah nah na nah.
+	 */
+	if ((tmp = ntohl(*p++)) != (u32)-1 && tmp != 0xffff) {
+		iap->ia_valid |= ATTR_MODE;
+		iap->ia_mode = tmp;
+	}
+	if ((tmp = ntohl(*p++)) != (u32)-1) {
+		iap->ia_uid = make_kuid(userns, tmp);
+		if (uid_valid(iap->ia_uid))
+			iap->ia_valid |= ATTR_UID;
+	}
+	if ((tmp = ntohl(*p++)) != (u32)-1) {
+		iap->ia_gid = make_kgid(userns, tmp);
+		if (gid_valid(iap->ia_gid))
+			iap->ia_valid |= ATTR_GID;
+	}
+	if ((tmp = ntohl(*p++)) != (u32)-1) {
+		iap->ia_valid |= ATTR_SIZE;
+		iap->ia_size = tmp;
+	}
+	tmp  = ntohl(*p++); tmp1 = ntohl(*p++);
+	if (tmp != (u32)-1 && tmp1 != (u32)-1) {
+		iap->ia_valid |= ATTR_ATIME | ATTR_ATIME_SET;
+		iap->ia_atime.tv_sec = tmp;
+		iap->ia_atime.tv_nsec = tmp1 * 1000; 
+	}
+	tmp  = ntohl(*p++); tmp1 = ntohl(*p++);
+	if (tmp != (u32)-1 && tmp1 != (u32)-1) {
+		iap->ia_valid |= ATTR_MTIME | ATTR_MTIME_SET;
+		iap->ia_mtime.tv_sec = tmp;
+		iap->ia_mtime.tv_nsec = tmp1 * 1000; 
+		/*
+		 * Passing the invalid value useconds=1000000 for mtime
+		 * is a Sun convention for "set both mtime and atime to
+		 * current server time".  It's needed to make permissions
+		 * checks for the "touch" program across v2 mounts to
+		 * Solaris and Irix boxes work correctly. See description of
+		 * sattr in section 6.1 of "NFS Illustrated" by
+		 * Brent Callaghan, Addison-Wesley, ISBN 0-201-32750-5
+		 */
+		if (tmp1 == 1000000)
+			iap->ia_valid &= ~(ATTR_ATIME_SET|ATTR_MTIME_SET);
+	}
+	return p;
+}
+
+static __be32 *
+encode_fattr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp,
+	     struct kstat *stat)
+{
+	struct user_namespace *userns = nfsd_user_namespace(rqstp);
+	struct dentry	*dentry = fhp->fh_dentry;
+	int type;
+	struct timespec64 time;
+	u32 f;
+
+	type = (stat->mode & S_IFMT);
+
+	*p++ = htonl(nfs_ftypes[type >> 12]);
+	*p++ = htonl((u32) stat->mode);
+	*p++ = htonl((u32) stat->nlink);
+	*p++ = htonl((u32) from_kuid_munged(userns, stat->uid));
+	*p++ = htonl((u32) from_kgid_munged(userns, stat->gid));
+
+	if (S_ISLNK(type) && stat->size > NFS_MAXPATHLEN) {
+		*p++ = htonl(NFS_MAXPATHLEN);
+	} else {
+		*p++ = htonl((u32) stat->size);
+	}
+	*p++ = htonl((u32) stat->blksize);
+	if (S_ISCHR(type) || S_ISBLK(type))
+		*p++ = htonl(new_encode_dev(stat->rdev));
+	else
+		*p++ = htonl(0xffffffff);
+	*p++ = htonl((u32) stat->blocks);
+	switch (fsid_source(fhp)) {
+	default:
+	case FSIDSOURCE_DEV:
+		*p++ = htonl(new_encode_dev(stat->dev));
+		break;
+	case FSIDSOURCE_FSID:
+		*p++ = htonl((u32) fhp->fh_export->ex_fsid);
+		break;
+	case FSIDSOURCE_UUID:
+		f = ((u32*)fhp->fh_export->ex_uuid)[0];
+		f ^= ((u32*)fhp->fh_export->ex_uuid)[1];
+		f ^= ((u32*)fhp->fh_export->ex_uuid)[2];
+		f ^= ((u32*)fhp->fh_export->ex_uuid)[3];
+		*p++ = htonl(f);
+		break;
+	}
+	*p++ = htonl((u32) stat->ino);
+	*p++ = htonl((u32) stat->atime.tv_sec);
+	*p++ = htonl(stat->atime.tv_nsec ? stat->atime.tv_nsec / 1000 : 0);
+	time = stat->mtime;
+	lease_get_mtime(d_inode(dentry), &time); 
+	*p++ = htonl((u32) time.tv_sec);
+	*p++ = htonl(time.tv_nsec ? time.tv_nsec / 1000 : 0); 
+	*p++ = htonl((u32) stat->ctime.tv_sec);
+	*p++ = htonl(stat->ctime.tv_nsec ? stat->ctime.tv_nsec / 1000 : 0);
+
+	return p;
+}
+
+/* Helper function for NFSv2 ACL code */
+__be32 *nfs2svc_encode_fattr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp, struct kstat *stat)
+{
+	return encode_fattr(rqstp, p, fhp, stat);
+}
+
+/*
+ * XDR decode functions
+ */
+int
+nfssvc_decode_void(struct svc_rqst *rqstp, __be32 *p)
+{
+	return xdr_argsize_check(rqstp, p);
+}
+
+int
+nfssvc_decode_fhandle(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd_fhandle *args = rqstp->rq_argp;
+
+	p = decode_fh(p, &args->fh);
+	if (!p)
+		return 0;
+	return xdr_argsize_check(rqstp, p);
+}
+
+int
+nfssvc_decode_sattrargs(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd_sattrargs *args = rqstp->rq_argp;
+
+	p = decode_fh(p, &args->fh);
+	if (!p)
+		return 0;
+	p = decode_sattr(p, &args->attrs, nfsd_user_namespace(rqstp));
+
+	return xdr_argsize_check(rqstp, p);
+}
+
+int
+nfssvc_decode_diropargs(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd_diropargs *args = rqstp->rq_argp;
+
+	if (!(p = decode_fh(p, &args->fh))
+	 || !(p = decode_filename(p, &args->name, &args->len)))
+		return 0;
+
+	return xdr_argsize_check(rqstp, p);
+}
+
+int
+nfssvc_decode_readargs(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd_readargs *args = rqstp->rq_argp;
+	unsigned int len;
+	int v;
+	p = decode_fh(p, &args->fh);
+	if (!p)
+		return 0;
+
+	args->offset    = ntohl(*p++);
+	len = args->count     = ntohl(*p++);
+	p++; /* totalcount - unused */
+
+	len = min_t(unsigned int, len, NFSSVC_MAXBLKSIZE_V2);
+
+	/* set up somewhere to store response.
+	 * We take pages, put them on reslist and include in iovec
+	 */
+	v=0;
+	while (len > 0) {
+		struct page *p = *(rqstp->rq_next_page++);
+
+		rqstp->rq_vec[v].iov_base = page_address(p);
+		rqstp->rq_vec[v].iov_len = min_t(unsigned int, len, PAGE_SIZE);
+		len -= rqstp->rq_vec[v].iov_len;
+		v++;
+	}
+	args->vlen = v;
+	return xdr_argsize_check(rqstp, p);
+}
+
+int
+nfssvc_decode_writeargs(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd_writeargs *args = rqstp->rq_argp;
+	unsigned int len, hdr, dlen;
+	struct kvec *head = rqstp->rq_arg.head;
+
+	p = decode_fh(p, &args->fh);
+	if (!p)
+		return 0;
+
+	p++;				/* beginoffset */
+	args->offset = ntohl(*p++);	/* offset */
+	p++;				/* totalcount */
+	len = args->len = ntohl(*p++);
+	/*
+	 * The protocol specifies a maximum of 8192 bytes.
+	 */
+	if (len > NFSSVC_MAXBLKSIZE_V2)
+		return 0;
+
+	/*
+	 * Check to make sure that we got the right number of
+	 * bytes.
+	 */
+	hdr = (void*)p - head->iov_base;
+	if (hdr > head->iov_len)
+		return 0;
+	dlen = head->iov_len + rqstp->rq_arg.page_len - hdr;
+
+	/*
+	 * Round the length of the data which was specified up to
+	 * the next multiple of XDR units and then compare that
+	 * against the length which was actually received.
+	 * Note that when RPCSEC/GSS (for example) is used, the
+	 * data buffer can be padded so dlen might be larger
+	 * than required.  It must never be smaller.
+	 */
+	if (dlen < XDR_QUADLEN(len)*4)
+		return 0;
+
+	args->first.iov_base = (void *)p;
+	args->first.iov_len = head->iov_len - hdr;
+	return 1;
+}
+
+int
+nfssvc_decode_createargs(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd_createargs *args = rqstp->rq_argp;
+
+	if (   !(p = decode_fh(p, &args->fh))
+	    || !(p = decode_filename(p, &args->name, &args->len)))
+		return 0;
+	p = decode_sattr(p, &args->attrs, nfsd_user_namespace(rqstp));
+
+	return xdr_argsize_check(rqstp, p);
+}
+
+int
+nfssvc_decode_renameargs(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd_renameargs *args = rqstp->rq_argp;
+
+	if (!(p = decode_fh(p, &args->ffh))
+	 || !(p = decode_filename(p, &args->fname, &args->flen))
+	 || !(p = decode_fh(p, &args->tfh))
+	 || !(p = decode_filename(p, &args->tname, &args->tlen)))
+		return 0;
+
+	return xdr_argsize_check(rqstp, p);
+}
+
+int
+nfssvc_decode_readlinkargs(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd_readlinkargs *args = rqstp->rq_argp;
+
+	p = decode_fh(p, &args->fh);
+	if (!p)
+		return 0;
+	args->buffer = page_address(*(rqstp->rq_next_page++));
+
+	return xdr_argsize_check(rqstp, p);
+}
+
+int
+nfssvc_decode_linkargs(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd_linkargs *args = rqstp->rq_argp;
+
+	if (!(p = decode_fh(p, &args->ffh))
+	 || !(p = decode_fh(p, &args->tfh))
+	 || !(p = decode_filename(p, &args->tname, &args->tlen)))
+		return 0;
+
+	return xdr_argsize_check(rqstp, p);
+}
+
+int
+nfssvc_decode_symlinkargs(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd_symlinkargs *args = rqstp->rq_argp;
+	char *base = (char *)p;
+	size_t xdrlen;
+
+	if (   !(p = decode_fh(p, &args->ffh))
+	    || !(p = decode_filename(p, &args->fname, &args->flen)))
+		return 0;
+
+	args->tlen = ntohl(*p++);
+	if (args->tlen == 0)
+		return 0;
+
+	args->first.iov_base = p;
+	args->first.iov_len = rqstp->rq_arg.head[0].iov_len;
+	args->first.iov_len -= (char *)p - base;
+
+	/* This request is never larger than a page. Therefore,
+	 * transport will deliver either:
+	 * 1. pathname in the pagelist -> sattr is in the tail.
+	 * 2. everything in the head buffer -> sattr is in the head.
+	 */
+	if (rqstp->rq_arg.page_len) {
+		if (args->tlen != rqstp->rq_arg.page_len)
+			return 0;
+		p = rqstp->rq_arg.tail[0].iov_base;
+	} else {
+		xdrlen = XDR_QUADLEN(args->tlen);
+		if (xdrlen > args->first.iov_len - (8 * sizeof(__be32)))
+			return 0;
+		p += xdrlen;
+	}
+	decode_sattr(p, &args->attrs, nfsd_user_namespace(rqstp));
+
+	return 1;
+}
+
+int
+nfssvc_decode_readdirargs(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd_readdirargs *args = rqstp->rq_argp;
+
+	p = decode_fh(p, &args->fh);
+	if (!p)
+		return 0;
+	args->cookie = ntohl(*p++);
+	args->count  = ntohl(*p++);
+	args->count  = min_t(u32, args->count, PAGE_SIZE);
+	args->buffer = page_address(*(rqstp->rq_next_page++));
+
+	return xdr_argsize_check(rqstp, p);
+}
+
+/*
+ * XDR encode functions
+ */
+int
+nfssvc_encode_void(struct svc_rqst *rqstp, __be32 *p)
+{
+	return xdr_ressize_check(rqstp, p);
+}
+
+int
+nfssvc_encode_stat(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd_stat *resp = rqstp->rq_resp;
+
+	*p++ = resp->status;
+	return xdr_ressize_check(rqstp, p);
+}
+
+int
+nfssvc_encode_attrstat(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd_attrstat *resp = rqstp->rq_resp;
+
+	*p++ = resp->status;
+	if (resp->status != nfs_ok)
+		goto out;
+	p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
+out:
+	return xdr_ressize_check(rqstp, p);
+}
+
+int
+nfssvc_encode_diropres(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd_diropres *resp = rqstp->rq_resp;
+
+	*p++ = resp->status;
+	if (resp->status != nfs_ok)
+		goto out;
+	p = encode_fh(p, &resp->fh);
+	p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
+out:
+	return xdr_ressize_check(rqstp, p);
+}
+
+int
+nfssvc_encode_readlinkres(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd_readlinkres *resp = rqstp->rq_resp;
+
+	*p++ = resp->status;
+	if (resp->status != nfs_ok)
+		return xdr_ressize_check(rqstp, p);
+
+	*p++ = htonl(resp->len);
+	xdr_ressize_check(rqstp, p);
+	rqstp->rq_res.page_len = resp->len;
+	if (resp->len & 3) {
+		/* need to pad the tail */
+		rqstp->rq_res.tail[0].iov_base = p;
+		*p = 0;
+		rqstp->rq_res.tail[0].iov_len = 4 - (resp->len&3);
+	}
+	return 1;
+}
+
+int
+nfssvc_encode_readres(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd_readres *resp = rqstp->rq_resp;
+
+	*p++ = resp->status;
+	if (resp->status != nfs_ok)
+		return xdr_ressize_check(rqstp, p);
+
+	p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
+	*p++ = htonl(resp->count);
+	xdr_ressize_check(rqstp, p);
+
+	/* now update rqstp->rq_res to reflect data as well */
+	rqstp->rq_res.page_len = resp->count;
+	if (resp->count & 3) {
+		/* need to pad the tail */
+		rqstp->rq_res.tail[0].iov_base = p;
+		*p = 0;
+		rqstp->rq_res.tail[0].iov_len = 4 - (resp->count&3);
+	}
+	return 1;
+}
+
+int
+nfssvc_encode_readdirres(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd_readdirres *resp = rqstp->rq_resp;
+
+	*p++ = resp->status;
+	if (resp->status != nfs_ok)
+		return xdr_ressize_check(rqstp, p);
+
+	xdr_ressize_check(rqstp, p);
+	p = resp->buffer;
+	*p++ = 0;			/* no more entries */
+	*p++ = htonl((resp->common.err == nfserr_eof));
+	rqstp->rq_res.page_len = (((unsigned long)p-1) & ~PAGE_MASK)+1;
+
+	return 1;
+}
+
+int
+nfssvc_encode_statfsres(struct svc_rqst *rqstp, __be32 *p)
+{
+	struct nfsd_statfsres *resp = rqstp->rq_resp;
+	struct kstatfs	*stat = &resp->stats;
+
+	*p++ = resp->status;
+	if (resp->status != nfs_ok)
+		return xdr_ressize_check(rqstp, p);
+
+	*p++ = htonl(NFSSVC_MAXBLKSIZE_V2);	/* max transfer size */
+	*p++ = htonl(stat->f_bsize);
+	*p++ = htonl(stat->f_blocks);
+	*p++ = htonl(stat->f_bfree);
+	*p++ = htonl(stat->f_bavail);
+	return xdr_ressize_check(rqstp, p);
+}
+
+int
+nfssvc_encode_entry(void *ccdv, const char *name,
+		    int namlen, loff_t offset, u64 ino, unsigned int d_type)
+{
+	struct readdir_cd *ccd = ccdv;
+	struct nfsd_readdirres *cd = container_of(ccd, struct nfsd_readdirres, common);
+	__be32	*p = cd->buffer;
+	int	buflen, slen;
+
+	/*
+	dprintk("nfsd: entry(%.*s off %ld ino %ld)\n",
+			namlen, name, offset, ino);
+	 */
+
+	if (offset > ~((u32) 0)) {
+		cd->common.err = nfserr_fbig;
+		return -EINVAL;
+	}
+	if (cd->offset)
+		*cd->offset = htonl(offset);
+
+	/* truncate filename */
+	namlen = min(namlen, NFS2_MAXNAMLEN);
+	slen = XDR_QUADLEN(namlen);
+
+	if ((buflen = cd->buflen - slen - 4) < 0) {
+		cd->common.err = nfserr_toosmall;
+		return -EINVAL;
+	}
+	if (ino > ~((u32) 0)) {
+		cd->common.err = nfserr_fbig;
+		return -EINVAL;
+	}
+	*p++ = xdr_one;				/* mark entry present */
+	*p++ = htonl((u32) ino);		/* file id */
+	p    = xdr_encode_array(p, name, namlen);/* name length & name */
+	cd->offset = p;			/* remember pointer */
+	*p++ = htonl(~0U);		/* offset of next entry */
+
+	cd->buflen = buflen;
+	cd->buffer = p;
+	cd->common.err = nfs_ok;
+	return 0;
+}
+
+/*
+ * XDR release functions
+ */
+void nfssvc_release_attrstat(struct svc_rqst *rqstp)
+{
+	struct nfsd_attrstat *resp = rqstp->rq_resp;
+
+	fh_put(&resp->fh);
+}
+
+void nfssvc_release_diropres(struct svc_rqst *rqstp)
+{
+	struct nfsd_diropres *resp = rqstp->rq_resp;
+
+	fh_put(&resp->fh);
+}
+
+void nfssvc_release_readres(struct svc_rqst *rqstp)
+{
+	struct nfsd_readres *resp = rqstp->rq_resp;
+
+	fh_put(&resp->fh);
+}
diff --git a/fs/nfsd/pnfs.h b/fs/nfsd/pnfs.h
new file mode 100644
index 000000000..4f4282d4e
--- /dev/null
+++ b/fs/nfsd/pnfs.h
@@ -0,0 +1,100 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _FS_NFSD_PNFS_H
+#define _FS_NFSD_PNFS_H 1
+
+#ifdef CONFIG_NFSD_V4
+#include <linux/exportfs.h>
+#include <linux/nfsd/export.h>
+
+#include "state.h"
+#include "xdr4.h"
+
+struct xdr_stream;
+
+struct nfsd4_deviceid_map {
+	struct list_head	hash;
+	u64			idx;
+	int			fsid_type;
+	u32			fsid[];
+};
+
+struct nfsd4_layout_ops {
+	u32		notify_types;
+	bool		disable_recalls;
+
+	__be32 (*proc_getdeviceinfo)(struct super_block *sb,
+			struct svc_rqst *rqstp,
+			struct nfs4_client *clp,
+			struct nfsd4_getdeviceinfo *gdevp);
+	__be32 (*encode_getdeviceinfo)(struct xdr_stream *xdr,
+			struct nfsd4_getdeviceinfo *gdevp);
+
+	__be32 (*proc_layoutget)(struct inode *, const struct svc_fh *fhp,
+			struct nfsd4_layoutget *lgp);
+	__be32 (*encode_layoutget)(struct xdr_stream *,
+			struct nfsd4_layoutget *lgp);
+
+	__be32 (*proc_layoutcommit)(struct inode *inode,
+			struct nfsd4_layoutcommit *lcp);
+
+	void (*fence_client)(struct nfs4_layout_stateid *ls);
+};
+
+extern const struct nfsd4_layout_ops *nfsd4_layout_ops[];
+#ifdef CONFIG_NFSD_BLOCKLAYOUT
+extern const struct nfsd4_layout_ops bl_layout_ops;
+#endif
+#ifdef CONFIG_NFSD_SCSILAYOUT
+extern const struct nfsd4_layout_ops scsi_layout_ops;
+#endif
+#ifdef CONFIG_NFSD_FLEXFILELAYOUT
+extern const struct nfsd4_layout_ops ff_layout_ops;
+#endif
+
+__be32 nfsd4_preprocess_layout_stateid(struct svc_rqst *rqstp,
+		struct nfsd4_compound_state *cstate, stateid_t *stateid,
+		bool create, u32 layout_type, struct nfs4_layout_stateid **lsp);
+__be32 nfsd4_insert_layout(struct nfsd4_layoutget *lgp,
+		struct nfs4_layout_stateid *ls);
+__be32 nfsd4_return_file_layouts(struct svc_rqst *rqstp,
+		struct nfsd4_compound_state *cstate,
+		struct nfsd4_layoutreturn *lrp);
+__be32 nfsd4_return_client_layouts(struct svc_rqst *rqstp,
+		struct nfsd4_compound_state *cstate,
+		struct nfsd4_layoutreturn *lrp);
+int nfsd4_set_deviceid(struct nfsd4_deviceid *id, const struct svc_fh *fhp,
+		u32 device_generation);
+struct nfsd4_deviceid_map *nfsd4_find_devid_map(int idx);
+#endif /* CONFIG_NFSD_V4 */
+
+#ifdef CONFIG_NFSD_PNFS
+void nfsd4_setup_layout_type(struct svc_export *exp);
+void nfsd4_return_all_client_layouts(struct nfs4_client *);
+void nfsd4_return_all_file_layouts(struct nfs4_client *clp,
+		struct nfs4_file *fp);
+int nfsd4_init_pnfs(void);
+void nfsd4_exit_pnfs(void);
+#else
+struct nfs4_client;
+struct nfs4_file;
+
+static inline void nfsd4_setup_layout_type(struct svc_export *exp)
+{
+}
+
+static inline void nfsd4_return_all_client_layouts(struct nfs4_client *clp)
+{
+}
+static inline void nfsd4_return_all_file_layouts(struct nfs4_client *clp,
+		struct nfs4_file *fp)
+{
+}
+static inline void nfsd4_exit_pnfs(void)
+{
+}
+static inline int nfsd4_init_pnfs(void)
+{
+	return 0;
+}
+#endif /* CONFIG_NFSD_PNFS */
+#endif /* _FS_NFSD_PNFS_H */
diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h
new file mode 100644
index 000000000..9eae11a9d
--- /dev/null
+++ b/fs/nfsd/state.h
@@ -0,0 +1,696 @@
+/*
+ *  Copyright (c) 2001 The Regents of the University of Michigan.
+ *  All rights reserved.
+ *
+ *  Kendrick Smith <kmsmith@umich.edu>
+ *  Andy Adamson <andros@umich.edu>
+ *  
+ *  Redistribution and use in source and binary forms, with or without
+ *  modification, are permitted provided that the following conditions
+ *  are met:
+ *  
+ *  1. Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *  2. Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *  3. Neither the name of the University nor the names of its
+ *     contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+ *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef _NFSD4_STATE_H
+#define _NFSD4_STATE_H
+
+#include <linux/idr.h>
+#include <linux/refcount.h>
+#include <linux/sunrpc/svc_xprt.h>
+#include "nfsfh.h"
+#include "nfsd.h"
+
+typedef struct {
+	u32             cl_boot;
+	u32             cl_id;
+} clientid_t;
+
+typedef struct {
+	clientid_t	so_clid;
+	u32		so_id;
+} stateid_opaque_t;
+
+typedef struct {
+	u32                     si_generation;
+	stateid_opaque_t        si_opaque;
+} stateid_t;
+
+typedef struct {
+	stateid_t		stid;
+#define NFS4_COPY_STID 1
+#define NFS4_COPYNOTIFY_STID 2
+	unsigned char		sc_type;
+	refcount_t		sc_count;
+} copy_stateid_t;
+
+struct nfsd4_callback {
+	struct nfs4_client *cb_clp;
+	struct rpc_message cb_msg;
+	const struct nfsd4_callback_ops *cb_ops;
+	struct work_struct cb_work;
+	int cb_seq_status;
+	int cb_status;
+	bool cb_need_restart;
+	bool cb_holds_slot;
+};
+
+struct nfsd4_callback_ops {
+	void (*prepare)(struct nfsd4_callback *);
+	int (*done)(struct nfsd4_callback *, struct rpc_task *);
+	void (*release)(struct nfsd4_callback *);
+};
+
+/*
+ * A core object that represents a "common" stateid. These are generally
+ * embedded within the different (more specific) stateid objects and contain
+ * fields that are of general use to any stateid.
+ */
+struct nfs4_stid {
+	refcount_t		sc_count;
+#define NFS4_OPEN_STID 1
+#define NFS4_LOCK_STID 2
+#define NFS4_DELEG_STID 4
+/* For an open stateid kept around *only* to process close replays: */
+#define NFS4_CLOSED_STID 8
+/* For a deleg stateid kept around only to process free_stateid's: */
+#define NFS4_REVOKED_DELEG_STID 16
+#define NFS4_CLOSED_DELEG_STID 32
+#define NFS4_LAYOUT_STID 64
+	struct list_head	sc_cp_list;
+	unsigned char		sc_type;
+	stateid_t		sc_stateid;
+	spinlock_t		sc_lock;
+	struct nfs4_client	*sc_client;
+	struct nfs4_file	*sc_file;
+	void			(*sc_free)(struct nfs4_stid *);
+};
+
+/* Keep a list of stateids issued by the COPY_NOTIFY, associate it with the
+ * parent OPEN/LOCK/DELEG stateid.
+ */
+struct nfs4_cpntf_state {
+	copy_stateid_t		cp_stateid;
+	struct list_head	cp_list;	/* per parent nfs4_stid */
+	stateid_t		cp_p_stateid;	/* copy of parent's stateid */
+	clientid_t		cp_p_clid;	/* copy of parent's clid */
+	time64_t		cpntf_time;	/* last time stateid used */
+};
+
+/*
+ * Represents a delegation stateid. The nfs4_client holds references to these
+ * and they are put when it is being destroyed or when the delegation is
+ * returned by the client:
+ *
+ * o 1 reference as long as a delegation is still in force (taken when it's
+ *   alloc'd, put when it's returned or revoked)
+ *
+ * o 1 reference as long as a recall rpc is in progress (taken when the lease
+ *   is broken, put when the rpc exits)
+ *
+ * o 1 more ephemeral reference for each nfsd thread currently doing something
+ *   with that delegation without holding the cl_lock
+ *
+ * If the server attempts to recall a delegation and the client doesn't do so
+ * before a timeout, the server may also revoke the delegation. In that case,
+ * the object will either be destroyed (v4.0) or moved to a per-client list of
+ * revoked delegations (v4.1+).
+ *
+ * This object is a superset of the nfs4_stid.
+ */
+struct nfs4_delegation {
+	struct nfs4_stid	dl_stid; /* must be first field */
+	struct list_head	dl_perfile;
+	struct list_head	dl_perclnt;
+	struct list_head	dl_recall_lru;  /* delegation recalled */
+	struct nfs4_clnt_odstate *dl_clnt_odstate;
+	u32			dl_type;
+	time64_t		dl_time;
+/* For recall: */
+	int			dl_retries;
+	struct nfsd4_callback	dl_recall;
+};
+
+#define cb_to_delegation(cb) \
+	container_of(cb, struct nfs4_delegation, dl_recall)
+
+/* client delegation callback info */
+struct nfs4_cb_conn {
+	/* SETCLIENTID info */
+	struct sockaddr_storage	cb_addr;
+	struct sockaddr_storage	cb_saddr;
+	size_t			cb_addrlen;
+	u32                     cb_prog; /* used only in 4.0 case;
+					    per-session otherwise */
+	u32                     cb_ident;	/* minorversion 0 only */
+	struct svc_xprt		*cb_xprt;	/* minorversion 1 only */
+};
+
+static inline struct nfs4_delegation *delegstateid(struct nfs4_stid *s)
+{
+	return container_of(s, struct nfs4_delegation, dl_stid);
+}
+
+/* Maximum number of slots per session. 160 is useful for long haul TCP */
+#define NFSD_MAX_SLOTS_PER_SESSION     160
+/* Maximum number of operations per session compound */
+#define NFSD_MAX_OPS_PER_COMPOUND	16
+/* Maximum  session per slot cache size */
+#define NFSD_SLOT_CACHE_SIZE		2048
+/* Maximum number of NFSD_SLOT_CACHE_SIZE slots per session */
+#define NFSD_CACHE_SIZE_SLOTS_PER_SESSION	32
+#define NFSD_MAX_MEM_PER_SESSION  \
+		(NFSD_CACHE_SIZE_SLOTS_PER_SESSION * NFSD_SLOT_CACHE_SIZE)
+
+struct nfsd4_slot {
+	u32	sl_seqid;
+	__be32	sl_status;
+	struct svc_cred sl_cred;
+	u32	sl_datalen;
+	u16	sl_opcnt;
+#define NFSD4_SLOT_INUSE	(1 << 0)
+#define NFSD4_SLOT_CACHETHIS	(1 << 1)
+#define NFSD4_SLOT_INITIALIZED	(1 << 2)
+#define NFSD4_SLOT_CACHED	(1 << 3)
+	u8	sl_flags;
+	char	sl_data[];
+};
+
+struct nfsd4_channel_attrs {
+	u32		headerpadsz;
+	u32		maxreq_sz;
+	u32		maxresp_sz;
+	u32		maxresp_cached;
+	u32		maxops;
+	u32		maxreqs;
+	u32		nr_rdma_attrs;
+	u32		rdma_attrs;
+};
+
+struct nfsd4_cb_sec {
+	u32	flavor; /* (u32)(-1) used to mean "no valid flavor" */
+	kuid_t	uid;
+	kgid_t	gid;
+};
+
+struct nfsd4_create_session {
+	clientid_t			clientid;
+	struct nfs4_sessionid		sessionid;
+	u32				seqid;
+	u32				flags;
+	struct nfsd4_channel_attrs	fore_channel;
+	struct nfsd4_channel_attrs	back_channel;
+	u32				callback_prog;
+	struct nfsd4_cb_sec		cb_sec;
+};
+
+struct nfsd4_backchannel_ctl {
+	u32	bc_cb_program;
+	struct nfsd4_cb_sec		bc_cb_sec;
+};
+
+struct nfsd4_bind_conn_to_session {
+	struct nfs4_sessionid		sessionid;
+	u32				dir;
+};
+
+/* The single slot clientid cache structure */
+struct nfsd4_clid_slot {
+	u32				sl_seqid;
+	__be32				sl_status;
+	struct nfsd4_create_session	sl_cr_ses;
+};
+
+struct nfsd4_conn {
+	struct list_head cn_persession;
+	struct svc_xprt *cn_xprt;
+	struct svc_xpt_user cn_xpt_user;
+	struct nfsd4_session *cn_session;
+/* CDFC4_FORE, CDFC4_BACK: */
+	unsigned char cn_flags;
+};
+
+/*
+ * Representation of a v4.1+ session. These are refcounted in a similar fashion
+ * to the nfs4_client. References are only taken when the server is actively
+ * working on the object (primarily during the processing of compounds).
+ */
+struct nfsd4_session {
+	atomic_t		se_ref;
+	struct list_head	se_hash;	/* hash by sessionid */
+	struct list_head	se_perclnt;
+/* See SESSION4_PERSIST, etc. for standard flags; this is internal-only: */
+#define NFS4_SESSION_DEAD	0x010
+	u32			se_flags;
+	struct nfs4_client	*se_client;
+	struct nfs4_sessionid	se_sessionid;
+	struct nfsd4_channel_attrs se_fchannel;
+	struct nfsd4_channel_attrs se_bchannel;
+	struct nfsd4_cb_sec	se_cb_sec;
+	struct list_head	se_conns;
+	u32			se_cb_prog;
+	u32			se_cb_seq_nr;
+	struct nfsd4_slot	*se_slots[];	/* forward channel slots */
+};
+
+/* formatted contents of nfs4_sessionid */
+struct nfsd4_sessionid {
+	clientid_t	clientid;
+	u32		sequence;
+	u32		reserved;
+};
+
+#define HEXDIR_LEN     33 /* hex version of 16 byte md5 of cl_name plus '\0' */
+
+/*
+ * struct nfs4_client - one per client.  Clientids live here.
+ *
+ * The initial object created by an NFS client using SETCLIENTID (for NFSv4.0)
+ * or EXCHANGE_ID (for NFSv4.1+). These objects are refcounted and timestamped.
+ * Each nfsd_net_ns object contains a set of these and they are tracked via
+ * short and long form clientid. They are hashed and searched for under the
+ * per-nfsd_net client_lock spinlock.
+ *
+ * References to it are only held during the processing of compounds, and in
+ * certain other operations. In their "resting state" they have a refcount of
+ * 0. If they are not renewed within a lease period, they become eligible for
+ * destruction by the laundromat.
+ *
+ * These objects can also be destroyed prematurely by the fault injection code,
+ * or if the client sends certain forms of SETCLIENTID or EXCHANGE_ID updates.
+ * Care is taken *not* to do this however when the objects have an elevated
+ * refcount.
+ *
+ * o Each nfs4_client is hashed by clientid
+ *
+ * o Each nfs4_clients is also hashed by name (the opaque quantity initially
+ *   sent by the client to identify itself).
+ * 	  
+ * o cl_perclient list is used to ensure no dangling stateowner references
+ *   when we expire the nfs4_client
+ */
+struct nfs4_client {
+	struct list_head	cl_idhash; 	/* hash by cl_clientid.id */
+	struct rb_node		cl_namenode;	/* link into by-name trees */
+	struct list_head	*cl_ownerstr_hashtbl;
+	struct list_head	cl_openowners;
+	struct idr		cl_stateids;	/* stateid lookup */
+	struct list_head	cl_delegations;
+	struct list_head	cl_revoked;	/* unacknowledged, revoked 4.1 state */
+	struct list_head        cl_lru;         /* tail queue */
+#ifdef CONFIG_NFSD_PNFS
+	struct list_head	cl_lo_states;	/* outstanding layout states */
+#endif
+	struct xdr_netobj	cl_name; 	/* id generated by client */
+	nfs4_verifier		cl_verifier; 	/* generated by client */
+	time64_t		cl_time;	/* time of last lease renewal */
+	struct sockaddr_storage	cl_addr; 	/* client ipaddress */
+	bool			cl_mach_cred;	/* SP4_MACH_CRED in force */
+	struct svc_cred		cl_cred; 	/* setclientid principal */
+	clientid_t		cl_clientid;	/* generated by server */
+	nfs4_verifier		cl_confirm;	/* generated by server */
+	u32			cl_minorversion;
+	/* NFSv4.1 client implementation id: */
+	struct xdr_netobj	cl_nii_domain;
+	struct xdr_netobj	cl_nii_name;
+	struct timespec64	cl_nii_time;
+
+	/* for v4.0 and v4.1 callbacks: */
+	struct nfs4_cb_conn	cl_cb_conn;
+#define NFSD4_CLIENT_CB_UPDATE		(0)
+#define NFSD4_CLIENT_CB_KILL		(1)
+#define NFSD4_CLIENT_STABLE		(2)	/* client on stable storage */
+#define NFSD4_CLIENT_RECLAIM_COMPLETE	(3)	/* reclaim_complete done */
+#define NFSD4_CLIENT_CONFIRMED		(4)	/* client is confirmed */
+#define NFSD4_CLIENT_UPCALL_LOCK	(5)	/* upcall serialization */
+#define NFSD4_CLIENT_CB_FLAG_MASK	(1 << NFSD4_CLIENT_CB_UPDATE | \
+					 1 << NFSD4_CLIENT_CB_KILL)
+	unsigned long		cl_flags;
+	const struct cred	*cl_cb_cred;
+	struct rpc_clnt		*cl_cb_client;
+	u32			cl_cb_ident;
+#define NFSD4_CB_UP		0
+#define NFSD4_CB_UNKNOWN	1
+#define NFSD4_CB_DOWN		2
+#define NFSD4_CB_FAULT		3
+	int			cl_cb_state;
+	struct nfsd4_callback	cl_cb_null;
+	struct nfsd4_session	*cl_cb_session;
+
+	/* for all client information that callback code might need: */
+	spinlock_t		cl_lock;
+
+	/* for nfs41 */
+	struct list_head	cl_sessions;
+	struct nfsd4_clid_slot	cl_cs_slot;	/* create_session slot */
+	u32			cl_exchange_flags;
+	/* number of rpc's in progress over an associated session: */
+	atomic_t		cl_rpc_users;
+	struct nfsdfs_client	cl_nfsdfs;
+	struct nfs4_op_map      cl_spo_must_allow;
+
+	/* debugging info directory under nfsd/clients/ : */
+	struct dentry		*cl_nfsd_dentry;
+
+	/* for nfs41 callbacks */
+	/* We currently support a single back channel with a single slot */
+	unsigned long		cl_cb_slot_busy;
+	struct rpc_wait_queue	cl_cb_waitq;	/* backchannel callers may */
+						/* wait here for slots */
+	struct net		*net;
+	struct list_head	async_copies;	/* list of async copies */
+	spinlock_t		async_lock;	/* lock for async copies */
+	atomic_t		cl_cb_inflight;	/* Outstanding callbacks */
+};
+
+/* struct nfs4_client_reset
+ * one per old client. Populates reset_str_hashtbl. Filled from conf_id_hashtbl
+ * upon lease reset, or from upcall to state_daemon (to read in state
+ * from non-volitile storage) upon reboot.
+ */
+struct nfs4_client_reclaim {
+	struct list_head	cr_strhash;	/* hash by cr_name */
+	struct nfs4_client	*cr_clp;	/* pointer to associated clp */
+	struct xdr_netobj	cr_name;	/* recovery dir name */
+	struct xdr_netobj	cr_princhash;
+};
+
+/* A reasonable value for REPLAY_ISIZE was estimated as follows:  
+ * The OPEN response, typically the largest, requires 
+ *   4(status) + 8(stateid) + 20(changeinfo) + 4(rflags) +  8(verifier) + 
+ *   4(deleg. type) + 8(deleg. stateid) + 4(deleg. recall flag) + 
+ *   20(deleg. space limit) + ~32(deleg. ace) = 112 bytes 
+ */
+
+#define NFSD4_REPLAY_ISIZE       112 
+
+/*
+ * Replay buffer, where the result of the last seqid-mutating operation 
+ * is cached. 
+ */
+struct nfs4_replay {
+	__be32			rp_status;
+	unsigned int		rp_buflen;
+	char			*rp_buf;
+	struct knfsd_fh		rp_openfh;
+	struct mutex		rp_mutex;
+	char			rp_ibuf[NFSD4_REPLAY_ISIZE];
+};
+
+struct nfs4_stateowner;
+
+struct nfs4_stateowner_operations {
+	void (*so_unhash)(struct nfs4_stateowner *);
+	void (*so_free)(struct nfs4_stateowner *);
+};
+
+/*
+ * A core object that represents either an open or lock owner. The object and
+ * lock owner objects have one of these embedded within them. Refcounts and
+ * other fields common to both owner types are contained within these
+ * structures.
+ */
+struct nfs4_stateowner {
+	struct list_head			so_strhash;
+	struct list_head			so_stateids;
+	struct nfs4_client			*so_client;
+	const struct nfs4_stateowner_operations	*so_ops;
+	/* after increment in nfsd4_bump_seqid, represents the next
+	 * sequence id expected from the client: */
+	atomic_t				so_count;
+	u32					so_seqid;
+	struct xdr_netobj			so_owner; /* open owner name */
+	struct nfs4_replay			so_replay;
+	bool					so_is_open_owner;
+};
+
+/*
+ * When a file is opened, the client provides an open state owner opaque string
+ * that indicates the "owner" of that open. These objects are refcounted.
+ * References to it are held by each open state associated with it. This object
+ * is a superset of the nfs4_stateowner struct.
+ */
+struct nfs4_openowner {
+	struct nfs4_stateowner	oo_owner; /* must be first field */
+	struct list_head        oo_perclient;
+	/*
+	 * We keep around openowners a little while after last close,
+	 * which saves clients from having to confirm, and allows us to
+	 * handle close replays if they come soon enough.  The close_lru
+	 * is a list of such openowners, to be reaped by the laundromat
+	 * thread eventually if they remain unused:
+	 */
+	struct list_head	oo_close_lru;
+	struct nfs4_ol_stateid *oo_last_closed_stid;
+	time64_t		oo_time; /* time of placement on so_close_lru */
+#define NFS4_OO_CONFIRMED   1
+	unsigned char		oo_flags;
+};
+
+/*
+ * Represents a generic "lockowner". Similar to an openowner. References to it
+ * are held by the lock stateids that are created on its behalf. This object is
+ * a superset of the nfs4_stateowner struct.
+ */
+struct nfs4_lockowner {
+	struct nfs4_stateowner	lo_owner;	/* must be first element */
+	struct list_head	lo_blocked;	/* blocked file_locks */
+};
+
+static inline struct nfs4_openowner * openowner(struct nfs4_stateowner *so)
+{
+	return container_of(so, struct nfs4_openowner, oo_owner);
+}
+
+static inline struct nfs4_lockowner * lockowner(struct nfs4_stateowner *so)
+{
+	return container_of(so, struct nfs4_lockowner, lo_owner);
+}
+
+/*
+ * Per-client state indicating no. of opens and outstanding delegations
+ * on a file from a particular client.'od' stands for 'open & delegation'
+ */
+struct nfs4_clnt_odstate {
+	struct nfs4_client	*co_client;
+	struct nfs4_file	*co_file;
+	struct list_head	co_perfile;
+	refcount_t		co_odcount;
+};
+
+/*
+ * nfs4_file: a file opened by some number of (open) nfs4_stateowners.
+ *
+ * These objects are global. nfsd keeps one instance of a nfs4_file per
+ * filehandle (though it may keep multiple file descriptors for each). Each
+ * inode can have multiple filehandles associated with it, so there is
+ * (potentially) a many to one relationship between this struct and struct
+ * inode.
+ *
+ * These are hashed by filehandle in the file_hashtbl, which is protected by
+ * the global state_lock spinlock.
+ */
+struct nfs4_file {
+	refcount_t		fi_ref;
+	spinlock_t		fi_lock;
+	struct hlist_node       fi_hash;	/* hash on fi_fhandle */
+	struct list_head        fi_stateids;
+	union {
+		struct list_head	fi_delegations;
+		struct rcu_head		fi_rcu;
+	};
+	struct list_head	fi_clnt_odstate;
+	/* One each for O_RDONLY, O_WRONLY, O_RDWR: */
+	struct nfsd_file	*fi_fds[3];
+	/*
+	 * Each open or lock stateid contributes 0-4 to the counts
+	 * below depending on which bits are set in st_access_bitmap:
+	 *     1 to fi_access[O_RDONLY] if NFS4_SHARE_ACCES_READ is set
+	 *   + 1 to fi_access[O_WRONLY] if NFS4_SHARE_ACCESS_WRITE is set
+	 *   + 1 to both of the above if NFS4_SHARE_ACCESS_BOTH is set.
+	 */
+	atomic_t		fi_access[2];
+	u32			fi_share_deny;
+	struct nfsd_file	*fi_deleg_file;
+	int			fi_delegees;
+	struct knfsd_fh		fi_fhandle;
+	bool			fi_had_conflict;
+#ifdef CONFIG_NFSD_PNFS
+	struct list_head	fi_lo_states;
+	atomic_t		fi_lo_recalls;
+#endif
+};
+
+/*
+ * A generic struct representing either a open or lock stateid. The nfs4_client
+ * holds a reference to each of these objects, and they in turn hold a
+ * reference to their respective stateowners. The client's reference is
+ * released in response to a close or unlock (depending on whether it's an open
+ * or lock stateid) or when the client is being destroyed.
+ *
+ * In the case of v4.0 open stateids, these objects are preserved for a little
+ * while after close in order to handle CLOSE replays. Those are eventually
+ * reclaimed via a LRU scheme by the laundromat.
+ *
+ * This object is a superset of the nfs4_stid. "ol" stands for "Open or Lock".
+ * Better suggestions welcome.
+ */
+struct nfs4_ol_stateid {
+	struct nfs4_stid		st_stid;
+	struct list_head		st_perfile;
+	struct list_head		st_perstateowner;
+	struct list_head		st_locks;
+	struct nfs4_stateowner		*st_stateowner;
+	struct nfs4_clnt_odstate	*st_clnt_odstate;
+	unsigned char			st_access_bmap;
+	unsigned char			st_deny_bmap;
+	struct nfs4_ol_stateid		*st_openstp;
+	struct mutex			st_mutex;
+};
+
+static inline struct nfs4_ol_stateid *openlockstateid(struct nfs4_stid *s)
+{
+	return container_of(s, struct nfs4_ol_stateid, st_stid);
+}
+
+struct nfs4_layout_stateid {
+	struct nfs4_stid		ls_stid;
+	struct list_head		ls_perclnt;
+	struct list_head		ls_perfile;
+	spinlock_t			ls_lock;
+	struct list_head		ls_layouts;
+	u32				ls_layout_type;
+	struct nfsd_file		*ls_file;
+	struct nfsd4_callback		ls_recall;
+	stateid_t			ls_recall_sid;
+	bool				ls_recalled;
+	struct mutex			ls_mutex;
+};
+
+static inline struct nfs4_layout_stateid *layoutstateid(struct nfs4_stid *s)
+{
+	return container_of(s, struct nfs4_layout_stateid, ls_stid);
+}
+
+/* flags for preprocess_seqid_op() */
+#define RD_STATE	        0x00000010
+#define WR_STATE	        0x00000020
+
+enum nfsd4_cb_op {
+	NFSPROC4_CLNT_CB_NULL = 0,
+	NFSPROC4_CLNT_CB_RECALL,
+	NFSPROC4_CLNT_CB_LAYOUT,
+	NFSPROC4_CLNT_CB_OFFLOAD,
+	NFSPROC4_CLNT_CB_SEQUENCE,
+	NFSPROC4_CLNT_CB_NOTIFY_LOCK,
+};
+
+/* Returns true iff a is later than b: */
+static inline bool nfsd4_stateid_generation_after(stateid_t *a, stateid_t *b)
+{
+	return (s32)(a->si_generation - b->si_generation) > 0;
+}
+
+/*
+ * When a client tries to get a lock on a file, we set one of these objects
+ * on the blocking lock. When the lock becomes free, we can then issue a
+ * CB_NOTIFY_LOCK to the server.
+ */
+struct nfsd4_blocked_lock {
+	struct list_head	nbl_list;
+	struct list_head	nbl_lru;
+	time64_t		nbl_time;
+	struct file_lock	nbl_lock;
+	struct knfsd_fh		nbl_fh;
+	struct nfsd4_callback	nbl_cb;
+};
+
+struct nfsd4_compound_state;
+struct nfsd_net;
+struct nfsd4_copy;
+
+extern __be32 nfs4_preprocess_stateid_op(struct svc_rqst *rqstp,
+		struct nfsd4_compound_state *cstate, struct svc_fh *fhp,
+		stateid_t *stateid, int flags, struct nfsd_file **filp,
+		struct nfs4_stid **cstid);
+__be32 nfsd4_lookup_stateid(struct nfsd4_compound_state *cstate,
+		     stateid_t *stateid, unsigned char typemask,
+		     struct nfs4_stid **s, struct nfsd_net *nn);
+struct nfs4_stid *nfs4_alloc_stid(struct nfs4_client *cl, struct kmem_cache *slab,
+				  void (*sc_free)(struct nfs4_stid *));
+int nfs4_init_copy_state(struct nfsd_net *nn, struct nfsd4_copy *copy);
+void nfs4_free_copy_state(struct nfsd4_copy *copy);
+struct nfs4_cpntf_state *nfs4_alloc_init_cpntf_state(struct nfsd_net *nn,
+			struct nfs4_stid *p_stid);
+void nfs4_unhash_stid(struct nfs4_stid *s);
+void nfs4_put_stid(struct nfs4_stid *s);
+void nfs4_inc_and_copy_stateid(stateid_t *dst, struct nfs4_stid *stid);
+void nfs4_remove_reclaim_record(struct nfs4_client_reclaim *, struct nfsd_net *);
+extern void nfs4_release_reclaim(struct nfsd_net *);
+extern struct nfs4_client_reclaim *nfsd4_find_reclaim_client(struct xdr_netobj name,
+							struct nfsd_net *nn);
+extern __be32 nfs4_check_open_reclaim(clientid_t *clid,
+		struct nfsd4_compound_state *cstate, struct nfsd_net *nn);
+extern void nfsd4_probe_callback(struct nfs4_client *clp);
+extern void nfsd4_probe_callback_sync(struct nfs4_client *clp);
+extern void nfsd4_change_callback(struct nfs4_client *clp, struct nfs4_cb_conn *);
+extern void nfsd4_init_cb(struct nfsd4_callback *cb, struct nfs4_client *clp,
+		const struct nfsd4_callback_ops *ops, enum nfsd4_cb_op op);
+extern void nfsd4_run_cb(struct nfsd4_callback *cb);
+extern int nfsd4_create_callback_queue(void);
+extern void nfsd4_destroy_callback_queue(void);
+extern void nfsd4_shutdown_callback(struct nfs4_client *);
+extern void nfsd4_shutdown_copy(struct nfs4_client *clp);
+extern void nfsd4_prepare_cb_recall(struct nfs4_delegation *dp);
+extern struct nfs4_client_reclaim *nfs4_client_to_reclaim(struct xdr_netobj name,
+				struct xdr_netobj princhash, struct nfsd_net *nn);
+extern bool nfs4_has_reclaimed_state(struct xdr_netobj name, struct nfsd_net *nn);
+
+struct nfs4_file *find_file(struct knfsd_fh *fh);
+void put_nfs4_file(struct nfs4_file *fi);
+extern void nfs4_put_copy(struct nfsd4_copy *copy);
+extern struct nfsd4_copy *
+find_async_copy(struct nfs4_client *clp, stateid_t *staetid);
+extern void nfs4_put_cpntf_state(struct nfsd_net *nn,
+				 struct nfs4_cpntf_state *cps);
+extern __be32 manage_cpntf_state(struct nfsd_net *nn, stateid_t *st,
+				 struct nfs4_client *clp,
+				 struct nfs4_cpntf_state **cps);
+static inline void get_nfs4_file(struct nfs4_file *fi)
+{
+	refcount_inc(&fi->fi_ref);
+}
+struct nfsd_file *find_any_file(struct nfs4_file *f);
+
+/* grace period management */
+void nfsd4_end_grace(struct nfsd_net *nn);
+
+/* nfs4recover operations */
+extern int nfsd4_client_tracking_init(struct net *net);
+extern void nfsd4_client_tracking_exit(struct net *net);
+extern void nfsd4_client_record_create(struct nfs4_client *clp);
+extern void nfsd4_client_record_remove(struct nfs4_client *clp);
+extern int nfsd4_client_record_check(struct nfs4_client *clp);
+extern void nfsd4_record_grace_done(struct nfsd_net *nn);
+
+#endif   /* NFSD4_STATE_H */
diff --git a/fs/nfsd/stats.c b/fs/nfsd/stats.c
new file mode 100644
index 000000000..b1bc582b0
--- /dev/null
+++ b/fs/nfsd/stats.c
@@ -0,0 +1,104 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * procfs-based user access to knfsd statistics
+ *
+ * /proc/net/rpc/nfsd
+ *
+ * Format:
+ *	rc <hits> <misses> <nocache>
+ *			Statistsics for the reply cache
+ *	fh <stale> <total-lookups> <anonlookups> <dir-not-in-dcache> <nondir-not-in-dcache>
+ *			statistics for filehandle lookup
+ *	io <bytes-read> <bytes-written>
+ *			statistics for IO throughput
+ *	th <threads> <fullcnt> <10%-20%> <20%-30%> ... <90%-100%> <100%> 
+ *			time (seconds) when nfsd thread usage above thresholds
+ *			and number of times that all threads were in use
+ *	ra cache-size  <10%  <20%  <30% ... <100% not-found
+ *			number of times that read-ahead entry was found that deep in
+ *			the cache.
+ *	plus generic RPC stats (see net/sunrpc/stats.c)
+ *
+ * Copyright (C) 1995, 1996, 1997 Olaf Kirch <okir@monad.swb.de>
+ */
+
+#include <linux/seq_file.h>
+#include <linux/module.h>
+#include <linux/sunrpc/stats.h>
+#include <net/net_namespace.h>
+
+#include "nfsd.h"
+
+struct nfsd_stats	nfsdstats;
+struct svc_stat		nfsd_svcstats = {
+	.program	= &nfsd_program,
+};
+
+static int nfsd_proc_show(struct seq_file *seq, void *v)
+{
+	int i;
+
+	seq_printf(seq, "rc %u %u %u\nfh %u %u %u %u %u\nio %u %u\n",
+		      nfsdstats.rchits,
+		      nfsdstats.rcmisses,
+		      nfsdstats.rcnocache,
+		      nfsdstats.fh_stale,
+		      nfsdstats.fh_lookup,
+		      nfsdstats.fh_anon,
+		      nfsdstats.fh_nocache_dir,
+		      nfsdstats.fh_nocache_nondir,
+		      nfsdstats.io_read,
+		      nfsdstats.io_write);
+	/* thread usage: */
+	seq_printf(seq, "th %u %u", nfsdstats.th_cnt, nfsdstats.th_fullcnt);
+	for (i=0; i<10; i++) {
+		unsigned int jifs = nfsdstats.th_usage[i];
+		unsigned int sec = jifs / HZ, msec = (jifs % HZ)*1000/HZ;
+		seq_printf(seq, " %u.%03u", sec, msec);
+	}
+
+	/* newline and ra-cache */
+	seq_printf(seq, "\nra %u", nfsdstats.ra_size);
+	for (i=0; i<11; i++)
+		seq_printf(seq, " %u", nfsdstats.ra_depth[i]);
+	seq_putc(seq, '\n');
+	
+	/* show my rpc info */
+	svc_seq_show(seq, &nfsd_svcstats);
+
+#ifdef CONFIG_NFSD_V4
+	/* Show count for individual nfsv4 operations */
+	/* Writing operation numbers 0 1 2 also for maintaining uniformity */
+	seq_printf(seq,"proc4ops %u", LAST_NFS4_OP + 1);
+	for (i = 0; i <= LAST_NFS4_OP; i++)
+		seq_printf(seq, " %u", nfsdstats.nfs4_opcount[i]);
+
+	seq_putc(seq, '\n');
+#endif
+
+	return 0;
+}
+
+static int nfsd_proc_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, nfsd_proc_show, NULL);
+}
+
+static const struct proc_ops nfsd_proc_ops = {
+	.proc_open	= nfsd_proc_open,
+	.proc_read	= seq_read,
+	.proc_lseek	= seq_lseek,
+	.proc_release	= single_release,
+};
+
+void
+nfsd_stat_init(void)
+{
+	svc_proc_register(&init_net, &nfsd_svcstats, &nfsd_proc_ops);
+}
+
+void
+nfsd_stat_shutdown(void)
+{
+	svc_proc_unregister(&init_net, "nfsd");
+}
diff --git a/fs/nfsd/stats.h b/fs/nfsd/stats.h
new file mode 100644
index 000000000..b23fdac69
--- /dev/null
+++ b/fs/nfsd/stats.h
@@ -0,0 +1,44 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Statistics for NFS server.
+ *
+ * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
+ */
+#ifndef _NFSD_STATS_H
+#define _NFSD_STATS_H
+
+#include <uapi/linux/nfsd/stats.h>
+
+
+struct nfsd_stats {
+	unsigned int	rchits;		/* repcache hits */
+	unsigned int	rcmisses;	/* repcache hits */
+	unsigned int	rcnocache;	/* uncached reqs */
+	unsigned int	fh_stale;	/* FH stale error */
+	unsigned int	fh_lookup;	/* dentry cached */
+	unsigned int	fh_anon;	/* anon file dentry returned */
+	unsigned int	fh_nocache_dir;	/* filehandle not found in dcache */
+	unsigned int	fh_nocache_nondir;	/* filehandle not found in dcache */
+	unsigned int	io_read;	/* bytes returned to read requests */
+	unsigned int	io_write;	/* bytes passed in write requests */
+	unsigned int	th_cnt;		/* number of available threads */
+	unsigned int	th_usage[10];	/* number of ticks during which n perdeciles
+					 * of available threads were in use */
+	unsigned int	th_fullcnt;	/* number of times last free thread was used */
+	unsigned int	ra_size;	/* size of ra cache */
+	unsigned int	ra_depth[11];	/* number of times ra entry was found that deep
+					 * in the cache (10percentiles). [10] = not found */
+#ifdef CONFIG_NFSD_V4
+	unsigned int	nfs4_opcount[LAST_NFS4_OP + 1];	/* count of individual nfsv4 operations */
+#endif
+
+};
+
+
+extern struct nfsd_stats	nfsdstats;
+extern struct svc_stat		nfsd_svcstats;
+
+void	nfsd_stat_init(void);
+void	nfsd_stat_shutdown(void);
+
+#endif /* _NFSD_STATS_H */
diff --git a/fs/nfsd/trace.c b/fs/nfsd/trace.c
new file mode 100644
index 000000000..90967466a
--- /dev/null
+++ b/fs/nfsd/trace.c
@@ -0,0 +1,3 @@
+
+#define CREATE_TRACE_POINTS
+#include "trace.h"
diff --git a/fs/nfsd/trace.h b/fs/nfsd/trace.h
new file mode 100644
index 000000000..a952f4a9b
--- /dev/null
+++ b/fs/nfsd/trace.h
@@ -0,0 +1,756 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2014 Christoph Hellwig.
+ */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM nfsd
+
+#if !defined(_NFSD_TRACE_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _NFSD_TRACE_H
+
+#include <linux/tracepoint.h>
+#include "export.h"
+#include "nfsfh.h"
+
+TRACE_EVENT(nfsd_compound,
+	TP_PROTO(const struct svc_rqst *rqst,
+		 u32 args_opcnt),
+	TP_ARGS(rqst, args_opcnt),
+	TP_STRUCT__entry(
+		__field(u32, xid)
+		__field(u32, args_opcnt)
+	),
+	TP_fast_assign(
+		__entry->xid = be32_to_cpu(rqst->rq_xid);
+		__entry->args_opcnt = args_opcnt;
+	),
+	TP_printk("xid=0x%08x opcnt=%u",
+		__entry->xid, __entry->args_opcnt)
+)
+
+TRACE_EVENT(nfsd_compound_status,
+	TP_PROTO(u32 args_opcnt,
+		 u32 resp_opcnt,
+		 __be32 status,
+		 const char *name),
+	TP_ARGS(args_opcnt, resp_opcnt, status, name),
+	TP_STRUCT__entry(
+		__field(u32, args_opcnt)
+		__field(u32, resp_opcnt)
+		__field(int, status)
+		__string(name, name)
+	),
+	TP_fast_assign(
+		__entry->args_opcnt = args_opcnt;
+		__entry->resp_opcnt = resp_opcnt;
+		__entry->status = be32_to_cpu(status);
+		__assign_str(name, name);
+	),
+	TP_printk("op=%u/%u %s status=%d",
+		__entry->resp_opcnt, __entry->args_opcnt,
+		__get_str(name), __entry->status)
+)
+
+DECLARE_EVENT_CLASS(nfsd_fh_err_class,
+	TP_PROTO(struct svc_rqst *rqstp,
+		 struct svc_fh	*fhp,
+		 int		status),
+	TP_ARGS(rqstp, fhp, status),
+	TP_STRUCT__entry(
+		__field(u32, xid)
+		__field(u32, fh_hash)
+		__field(int, status)
+	),
+	TP_fast_assign(
+		__entry->xid = be32_to_cpu(rqstp->rq_xid);
+		__entry->fh_hash = knfsd_fh_hash(&fhp->fh_handle);
+		__entry->status = status;
+	),
+	TP_printk("xid=0x%08x fh_hash=0x%08x status=%d",
+		  __entry->xid, __entry->fh_hash,
+		  __entry->status)
+)
+
+#define DEFINE_NFSD_FH_ERR_EVENT(name)		\
+DEFINE_EVENT(nfsd_fh_err_class, nfsd_##name,	\
+	TP_PROTO(struct svc_rqst *rqstp,	\
+		 struct svc_fh	*fhp,		\
+		 int		status),	\
+	TP_ARGS(rqstp, fhp, status))
+
+DEFINE_NFSD_FH_ERR_EVENT(set_fh_dentry_badexport);
+DEFINE_NFSD_FH_ERR_EVENT(set_fh_dentry_badhandle);
+
+TRACE_EVENT(nfsd_exp_find_key,
+	TP_PROTO(const struct svc_expkey *key,
+		 int status),
+	TP_ARGS(key, status),
+	TP_STRUCT__entry(
+		__field(int, fsidtype)
+		__array(u32, fsid, 6)
+		__string(auth_domain, key->ek_client->name)
+		__field(int, status)
+	),
+	TP_fast_assign(
+		__entry->fsidtype = key->ek_fsidtype;
+		memcpy(__entry->fsid, key->ek_fsid, 4*6);
+		__assign_str(auth_domain, key->ek_client->name);
+		__entry->status = status;
+	),
+	TP_printk("fsid=%x::%s domain=%s status=%d",
+		__entry->fsidtype,
+		__print_array(__entry->fsid, 6, 4),
+		__get_str(auth_domain),
+		__entry->status
+	)
+);
+
+TRACE_EVENT(nfsd_expkey_update,
+	TP_PROTO(const struct svc_expkey *key, const char *exp_path),
+	TP_ARGS(key, exp_path),
+	TP_STRUCT__entry(
+		__field(int, fsidtype)
+		__array(u32, fsid, 6)
+		__string(auth_domain, key->ek_client->name)
+		__string(path, exp_path)
+		__field(bool, cache)
+	),
+	TP_fast_assign(
+		__entry->fsidtype = key->ek_fsidtype;
+		memcpy(__entry->fsid, key->ek_fsid, 4*6);
+		__assign_str(auth_domain, key->ek_client->name);
+		__assign_str(path, exp_path);
+		__entry->cache = !test_bit(CACHE_NEGATIVE, &key->h.flags);
+	),
+	TP_printk("fsid=%x::%s domain=%s path=%s cache=%s",
+		__entry->fsidtype,
+		__print_array(__entry->fsid, 6, 4),
+		__get_str(auth_domain),
+		__get_str(path),
+		__entry->cache ? "pos" : "neg"
+	)
+);
+
+TRACE_EVENT(nfsd_exp_get_by_name,
+	TP_PROTO(const struct svc_export *key,
+		 int status),
+	TP_ARGS(key, status),
+	TP_STRUCT__entry(
+		__string(path, key->ex_path.dentry->d_name.name)
+		__string(auth_domain, key->ex_client->name)
+		__field(int, status)
+	),
+	TP_fast_assign(
+		__assign_str(path, key->ex_path.dentry->d_name.name);
+		__assign_str(auth_domain, key->ex_client->name);
+		__entry->status = status;
+	),
+	TP_printk("path=%s domain=%s status=%d",
+		__get_str(path),
+		__get_str(auth_domain),
+		__entry->status
+	)
+);
+
+TRACE_EVENT(nfsd_export_update,
+	TP_PROTO(const struct svc_export *key),
+	TP_ARGS(key),
+	TP_STRUCT__entry(
+		__string(path, key->ex_path.dentry->d_name.name)
+		__string(auth_domain, key->ex_client->name)
+		__field(bool, cache)
+	),
+	TP_fast_assign(
+		__assign_str(path, key->ex_path.dentry->d_name.name);
+		__assign_str(auth_domain, key->ex_client->name);
+		__entry->cache = !test_bit(CACHE_NEGATIVE, &key->h.flags);
+	),
+	TP_printk("path=%s domain=%s cache=%s",
+		__get_str(path),
+		__get_str(auth_domain),
+		__entry->cache ? "pos" : "neg"
+	)
+);
+
+DECLARE_EVENT_CLASS(nfsd_io_class,
+	TP_PROTO(struct svc_rqst *rqstp,
+		 struct svc_fh	*fhp,
+		 u64		offset,
+		 u32		len),
+	TP_ARGS(rqstp, fhp, offset, len),
+	TP_STRUCT__entry(
+		__field(u32, xid)
+		__field(u32, fh_hash)
+		__field(u64, offset)
+		__field(u32, len)
+	),
+	TP_fast_assign(
+		__entry->xid = be32_to_cpu(rqstp->rq_xid);
+		__entry->fh_hash = knfsd_fh_hash(&fhp->fh_handle);
+		__entry->offset = offset;
+		__entry->len = len;
+	),
+	TP_printk("xid=0x%08x fh_hash=0x%08x offset=%llu len=%u",
+		  __entry->xid, __entry->fh_hash,
+		  __entry->offset, __entry->len)
+)
+
+#define DEFINE_NFSD_IO_EVENT(name)		\
+DEFINE_EVENT(nfsd_io_class, nfsd_##name,	\
+	TP_PROTO(struct svc_rqst *rqstp,	\
+		 struct svc_fh	*fhp,		\
+		 u64		offset,		\
+		 u32		len),		\
+	TP_ARGS(rqstp, fhp, offset, len))
+
+DEFINE_NFSD_IO_EVENT(read_start);
+DEFINE_NFSD_IO_EVENT(read_splice);
+DEFINE_NFSD_IO_EVENT(read_vector);
+DEFINE_NFSD_IO_EVENT(read_io_done);
+DEFINE_NFSD_IO_EVENT(read_done);
+DEFINE_NFSD_IO_EVENT(write_start);
+DEFINE_NFSD_IO_EVENT(write_opened);
+DEFINE_NFSD_IO_EVENT(write_io_done);
+DEFINE_NFSD_IO_EVENT(write_done);
+
+DECLARE_EVENT_CLASS(nfsd_err_class,
+	TP_PROTO(struct svc_rqst *rqstp,
+		 struct svc_fh	*fhp,
+		 loff_t		offset,
+		 int		status),
+	TP_ARGS(rqstp, fhp, offset, status),
+	TP_STRUCT__entry(
+		__field(u32, xid)
+		__field(u32, fh_hash)
+		__field(loff_t, offset)
+		__field(int, status)
+	),
+	TP_fast_assign(
+		__entry->xid = be32_to_cpu(rqstp->rq_xid);
+		__entry->fh_hash = knfsd_fh_hash(&fhp->fh_handle);
+		__entry->offset = offset;
+		__entry->status = status;
+	),
+	TP_printk("xid=0x%08x fh_hash=0x%08x offset=%lld status=%d",
+		  __entry->xid, __entry->fh_hash,
+		  __entry->offset, __entry->status)
+)
+
+#define DEFINE_NFSD_ERR_EVENT(name)		\
+DEFINE_EVENT(nfsd_err_class, nfsd_##name,	\
+	TP_PROTO(struct svc_rqst *rqstp,	\
+		 struct svc_fh	*fhp,		\
+		 loff_t		offset,		\
+		 int		len),		\
+	TP_ARGS(rqstp, fhp, offset, len))
+
+DEFINE_NFSD_ERR_EVENT(read_err);
+DEFINE_NFSD_ERR_EVENT(write_err);
+
+#include "state.h"
+#include "filecache.h"
+#include "vfs.h"
+
+DECLARE_EVENT_CLASS(nfsd_stateid_class,
+	TP_PROTO(stateid_t *stp),
+	TP_ARGS(stp),
+	TP_STRUCT__entry(
+		__field(u32, cl_boot)
+		__field(u32, cl_id)
+		__field(u32, si_id)
+		__field(u32, si_generation)
+	),
+	TP_fast_assign(
+		__entry->cl_boot = stp->si_opaque.so_clid.cl_boot;
+		__entry->cl_id = stp->si_opaque.so_clid.cl_id;
+		__entry->si_id = stp->si_opaque.so_id;
+		__entry->si_generation = stp->si_generation;
+	),
+	TP_printk("client %08x:%08x stateid %08x:%08x",
+		__entry->cl_boot,
+		__entry->cl_id,
+		__entry->si_id,
+		__entry->si_generation)
+)
+
+#define DEFINE_STATEID_EVENT(name) \
+DEFINE_EVENT(nfsd_stateid_class, nfsd_##name, \
+	TP_PROTO(stateid_t *stp), \
+	TP_ARGS(stp))
+
+DEFINE_STATEID_EVENT(layoutstate_alloc);
+DEFINE_STATEID_EVENT(layoutstate_unhash);
+DEFINE_STATEID_EVENT(layoutstate_free);
+DEFINE_STATEID_EVENT(layout_get_lookup_fail);
+DEFINE_STATEID_EVENT(layout_commit_lookup_fail);
+DEFINE_STATEID_EVENT(layout_return_lookup_fail);
+DEFINE_STATEID_EVENT(layout_recall);
+DEFINE_STATEID_EVENT(layout_recall_done);
+DEFINE_STATEID_EVENT(layout_recall_fail);
+DEFINE_STATEID_EVENT(layout_recall_release);
+
+DEFINE_STATEID_EVENT(open);
+DEFINE_STATEID_EVENT(deleg_read);
+DEFINE_STATEID_EVENT(deleg_break);
+DEFINE_STATEID_EVENT(deleg_recall);
+
+DECLARE_EVENT_CLASS(nfsd_stateseqid_class,
+	TP_PROTO(u32 seqid, const stateid_t *stp),
+	TP_ARGS(seqid, stp),
+	TP_STRUCT__entry(
+		__field(u32, seqid)
+		__field(u32, cl_boot)
+		__field(u32, cl_id)
+		__field(u32, si_id)
+		__field(u32, si_generation)
+	),
+	TP_fast_assign(
+		__entry->seqid = seqid;
+		__entry->cl_boot = stp->si_opaque.so_clid.cl_boot;
+		__entry->cl_id = stp->si_opaque.so_clid.cl_id;
+		__entry->si_id = stp->si_opaque.so_id;
+		__entry->si_generation = stp->si_generation;
+	),
+	TP_printk("seqid=%u client %08x:%08x stateid %08x:%08x",
+		__entry->seqid, __entry->cl_boot, __entry->cl_id,
+		__entry->si_id, __entry->si_generation)
+)
+
+#define DEFINE_STATESEQID_EVENT(name) \
+DEFINE_EVENT(nfsd_stateseqid_class, nfsd_##name, \
+	TP_PROTO(u32 seqid, const stateid_t *stp), \
+	TP_ARGS(seqid, stp))
+
+DEFINE_STATESEQID_EVENT(preprocess);
+DEFINE_STATESEQID_EVENT(open_confirm);
+
+DECLARE_EVENT_CLASS(nfsd_clientid_class,
+	TP_PROTO(const clientid_t *clid),
+	TP_ARGS(clid),
+	TP_STRUCT__entry(
+		__field(u32, cl_boot)
+		__field(u32, cl_id)
+	),
+	TP_fast_assign(
+		__entry->cl_boot = clid->cl_boot;
+		__entry->cl_id = clid->cl_id;
+	),
+	TP_printk("client %08x:%08x", __entry->cl_boot, __entry->cl_id)
+)
+
+#define DEFINE_CLIENTID_EVENT(name) \
+DEFINE_EVENT(nfsd_clientid_class, nfsd_clid_##name, \
+	TP_PROTO(const clientid_t *clid), \
+	TP_ARGS(clid))
+
+DEFINE_CLIENTID_EVENT(expired);
+DEFINE_CLIENTID_EVENT(purged);
+DEFINE_CLIENTID_EVENT(renew);
+DEFINE_CLIENTID_EVENT(stale);
+
+DECLARE_EVENT_CLASS(nfsd_net_class,
+	TP_PROTO(const struct nfsd_net *nn),
+	TP_ARGS(nn),
+	TP_STRUCT__entry(
+		__field(unsigned long long, boot_time)
+	),
+	TP_fast_assign(
+		__entry->boot_time = nn->boot_time;
+	),
+	TP_printk("boot_time=%16llx", __entry->boot_time)
+)
+
+#define DEFINE_NET_EVENT(name) \
+DEFINE_EVENT(nfsd_net_class, nfsd_##name, \
+	TP_PROTO(const struct nfsd_net *nn), \
+	TP_ARGS(nn))
+
+DEFINE_NET_EVENT(grace_start);
+DEFINE_NET_EVENT(grace_complete);
+
+TRACE_EVENT(nfsd_clid_inuse_err,
+	TP_PROTO(const struct nfs4_client *clp),
+	TP_ARGS(clp),
+	TP_STRUCT__entry(
+		__field(u32, cl_boot)
+		__field(u32, cl_id)
+		__array(unsigned char, addr, sizeof(struct sockaddr_in6))
+		__field(unsigned int, namelen)
+		__dynamic_array(unsigned char, name, clp->cl_name.len)
+	),
+	TP_fast_assign(
+		__entry->cl_boot = clp->cl_clientid.cl_boot;
+		__entry->cl_id = clp->cl_clientid.cl_id;
+		memcpy(__entry->addr, &clp->cl_addr,
+			sizeof(struct sockaddr_in6));
+		__entry->namelen = clp->cl_name.len;
+		memcpy(__get_dynamic_array(name), clp->cl_name.data,
+			clp->cl_name.len);
+	),
+	TP_printk("nfs4_clientid %.*s already in use by %pISpc, client %08x:%08x",
+		__entry->namelen, __get_str(name), __entry->addr,
+		__entry->cl_boot, __entry->cl_id)
+)
+
+TRACE_DEFINE_ENUM(NFSD_FILE_HASHED);
+TRACE_DEFINE_ENUM(NFSD_FILE_PENDING);
+TRACE_DEFINE_ENUM(NFSD_FILE_BREAK_READ);
+TRACE_DEFINE_ENUM(NFSD_FILE_BREAK_WRITE);
+TRACE_DEFINE_ENUM(NFSD_FILE_REFERENCED);
+
+#define show_nf_flags(val)						\
+	__print_flags(val, "|",						\
+		{ 1 << NFSD_FILE_HASHED,	"HASHED" },		\
+		{ 1 << NFSD_FILE_PENDING,	"PENDING" },		\
+		{ 1 << NFSD_FILE_BREAK_READ,	"BREAK_READ" },		\
+		{ 1 << NFSD_FILE_BREAK_WRITE,	"BREAK_WRITE" },	\
+		{ 1 << NFSD_FILE_REFERENCED,	"REFERENCED"})
+
+/* FIXME: This should probably be fleshed out in the future. */
+#define show_nf_may(val)						\
+	__print_flags(val, "|",						\
+		{ NFSD_MAY_READ,		"READ" },		\
+		{ NFSD_MAY_WRITE,		"WRITE" },		\
+		{ NFSD_MAY_NOT_BREAK_LEASE,	"NOT_BREAK_LEASE" })
+
+DECLARE_EVENT_CLASS(nfsd_file_class,
+	TP_PROTO(struct nfsd_file *nf),
+	TP_ARGS(nf),
+	TP_STRUCT__entry(
+		__field(unsigned int, nf_hashval)
+		__field(void *, nf_inode)
+		__field(int, nf_ref)
+		__field(unsigned long, nf_flags)
+		__field(unsigned char, nf_may)
+		__field(struct file *, nf_file)
+	),
+	TP_fast_assign(
+		__entry->nf_hashval = nf->nf_hashval;
+		__entry->nf_inode = nf->nf_inode;
+		__entry->nf_ref = refcount_read(&nf->nf_ref);
+		__entry->nf_flags = nf->nf_flags;
+		__entry->nf_may = nf->nf_may;
+		__entry->nf_file = nf->nf_file;
+	),
+	TP_printk("hash=0x%x inode=0x%p ref=%d flags=%s may=%s file=%p",
+		__entry->nf_hashval,
+		__entry->nf_inode,
+		__entry->nf_ref,
+		show_nf_flags(__entry->nf_flags),
+		show_nf_may(__entry->nf_may),
+		__entry->nf_file)
+)
+
+#define DEFINE_NFSD_FILE_EVENT(name) \
+DEFINE_EVENT(nfsd_file_class, name, \
+	TP_PROTO(struct nfsd_file *nf), \
+	TP_ARGS(nf))
+
+DEFINE_NFSD_FILE_EVENT(nfsd_file_alloc);
+DEFINE_NFSD_FILE_EVENT(nfsd_file_put_final);
+DEFINE_NFSD_FILE_EVENT(nfsd_file_unhash);
+DEFINE_NFSD_FILE_EVENT(nfsd_file_put);
+DEFINE_NFSD_FILE_EVENT(nfsd_file_unhash_and_release_locked);
+
+TRACE_EVENT(nfsd_file_acquire,
+	TP_PROTO(struct svc_rqst *rqstp, unsigned int hash,
+		 struct inode *inode, unsigned int may_flags,
+		 struct nfsd_file *nf, __be32 status),
+
+	TP_ARGS(rqstp, hash, inode, may_flags, nf, status),
+
+	TP_STRUCT__entry(
+		__field(u32, xid)
+		__field(unsigned int, hash)
+		__field(void *, inode)
+		__field(unsigned int, may_flags)
+		__field(int, nf_ref)
+		__field(unsigned long, nf_flags)
+		__field(unsigned char, nf_may)
+		__field(struct file *, nf_file)
+		__field(u32, status)
+	),
+
+	TP_fast_assign(
+		__entry->xid = be32_to_cpu(rqstp->rq_xid);
+		__entry->hash = hash;
+		__entry->inode = inode;
+		__entry->may_flags = may_flags;
+		__entry->nf_ref = nf ? refcount_read(&nf->nf_ref) : 0;
+		__entry->nf_flags = nf ? nf->nf_flags : 0;
+		__entry->nf_may = nf ? nf->nf_may : 0;
+		__entry->nf_file = nf ? nf->nf_file : NULL;
+		__entry->status = be32_to_cpu(status);
+	),
+
+	TP_printk("xid=0x%x hash=0x%x inode=0x%p may_flags=%s ref=%d nf_flags=%s nf_may=%s nf_file=0x%p status=%u",
+			__entry->xid, __entry->hash, __entry->inode,
+			show_nf_may(__entry->may_flags), __entry->nf_ref,
+			show_nf_flags(__entry->nf_flags),
+			show_nf_may(__entry->nf_may), __entry->nf_file,
+			__entry->status)
+);
+
+DECLARE_EVENT_CLASS(nfsd_file_search_class,
+	TP_PROTO(struct inode *inode, unsigned int hash, int found),
+	TP_ARGS(inode, hash, found),
+	TP_STRUCT__entry(
+		__field(struct inode *, inode)
+		__field(unsigned int, hash)
+		__field(int, found)
+	),
+	TP_fast_assign(
+		__entry->inode = inode;
+		__entry->hash = hash;
+		__entry->found = found;
+	),
+	TP_printk("hash=0x%x inode=0x%p found=%d", __entry->hash,
+			__entry->inode, __entry->found)
+);
+
+#define DEFINE_NFSD_FILE_SEARCH_EVENT(name)				\
+DEFINE_EVENT(nfsd_file_search_class, name,				\
+	TP_PROTO(struct inode *inode, unsigned int hash, int found),	\
+	TP_ARGS(inode, hash, found))
+
+DEFINE_NFSD_FILE_SEARCH_EVENT(nfsd_file_close_inode_sync);
+DEFINE_NFSD_FILE_SEARCH_EVENT(nfsd_file_close_inode);
+DEFINE_NFSD_FILE_SEARCH_EVENT(nfsd_file_is_cached);
+
+TRACE_EVENT(nfsd_file_fsnotify_handle_event,
+	TP_PROTO(struct inode *inode, u32 mask),
+	TP_ARGS(inode, mask),
+	TP_STRUCT__entry(
+		__field(struct inode *, inode)
+		__field(unsigned int, nlink)
+		__field(umode_t, mode)
+		__field(u32, mask)
+	),
+	TP_fast_assign(
+		__entry->inode = inode;
+		__entry->nlink = inode->i_nlink;
+		__entry->mode = inode->i_mode;
+		__entry->mask = mask;
+	),
+	TP_printk("inode=0x%p nlink=%u mode=0%ho mask=0x%x", __entry->inode,
+			__entry->nlink, __entry->mode, __entry->mask)
+);
+
+#include "cache.h"
+
+TRACE_DEFINE_ENUM(RC_DROPIT);
+TRACE_DEFINE_ENUM(RC_REPLY);
+TRACE_DEFINE_ENUM(RC_DOIT);
+
+#define show_drc_retval(x)						\
+	__print_symbolic(x,						\
+		{ RC_DROPIT, "DROPIT" },				\
+		{ RC_REPLY, "REPLY" },					\
+		{ RC_DOIT, "DOIT" })
+
+TRACE_EVENT(nfsd_drc_found,
+	TP_PROTO(
+		const struct nfsd_net *nn,
+		const struct svc_rqst *rqstp,
+		int result
+	),
+	TP_ARGS(nn, rqstp, result),
+	TP_STRUCT__entry(
+		__field(unsigned long long, boot_time)
+		__field(unsigned long, result)
+		__field(u32, xid)
+	),
+	TP_fast_assign(
+		__entry->boot_time = nn->boot_time;
+		__entry->result = result;
+		__entry->xid = be32_to_cpu(rqstp->rq_xid);
+	),
+	TP_printk("boot_time=%16llx xid=0x%08x result=%s",
+		__entry->boot_time, __entry->xid,
+		show_drc_retval(__entry->result))
+
+);
+
+TRACE_EVENT(nfsd_drc_mismatch,
+	TP_PROTO(
+		const struct nfsd_net *nn,
+		const struct svc_cacherep *key,
+		const struct svc_cacherep *rp
+	),
+	TP_ARGS(nn, key, rp),
+	TP_STRUCT__entry(
+		__field(unsigned long long, boot_time)
+		__field(u32, xid)
+		__field(u32, cached)
+		__field(u32, ingress)
+	),
+	TP_fast_assign(
+		__entry->boot_time = nn->boot_time;
+		__entry->xid = be32_to_cpu(key->c_key.k_xid);
+		__entry->cached = (__force u32)key->c_key.k_csum;
+		__entry->ingress = (__force u32)rp->c_key.k_csum;
+	),
+	TP_printk("boot_time=%16llx xid=0x%08x cached-csum=0x%08x ingress-csum=0x%08x",
+		__entry->boot_time, __entry->xid, __entry->cached,
+		__entry->ingress)
+);
+
+TRACE_EVENT(nfsd_cb_args,
+	TP_PROTO(
+		const struct nfs4_client *clp,
+		const struct nfs4_cb_conn *conn
+	),
+	TP_ARGS(clp, conn),
+	TP_STRUCT__entry(
+		__field(u32, cl_boot)
+		__field(u32, cl_id)
+		__field(u32, prog)
+		__field(u32, ident)
+		__array(unsigned char, addr, sizeof(struct sockaddr_in6))
+	),
+	TP_fast_assign(
+		__entry->cl_boot = clp->cl_clientid.cl_boot;
+		__entry->cl_id = clp->cl_clientid.cl_id;
+		__entry->prog = conn->cb_prog;
+		__entry->ident = conn->cb_ident;
+		memcpy(__entry->addr, &conn->cb_addr,
+			sizeof(struct sockaddr_in6));
+	),
+	TP_printk("client %08x:%08x callback addr=%pISpc prog=%u ident=%u",
+		__entry->cl_boot, __entry->cl_id,
+		__entry->addr, __entry->prog, __entry->ident)
+);
+
+TRACE_EVENT(nfsd_cb_nodelegs,
+	TP_PROTO(const struct nfs4_client *clp),
+	TP_ARGS(clp),
+	TP_STRUCT__entry(
+		__field(u32, cl_boot)
+		__field(u32, cl_id)
+	),
+	TP_fast_assign(
+		__entry->cl_boot = clp->cl_clientid.cl_boot;
+		__entry->cl_id = clp->cl_clientid.cl_id;
+	),
+	TP_printk("client %08x:%08x", __entry->cl_boot, __entry->cl_id)
+)
+
+TRACE_DEFINE_ENUM(NFSD4_CB_UP);
+TRACE_DEFINE_ENUM(NFSD4_CB_UNKNOWN);
+TRACE_DEFINE_ENUM(NFSD4_CB_DOWN);
+TRACE_DEFINE_ENUM(NFSD4_CB_FAULT);
+
+#define show_cb_state(val)						\
+	__print_symbolic(val,						\
+		{ NFSD4_CB_UP,		"UP" },				\
+		{ NFSD4_CB_UNKNOWN,	"UNKNOWN" },			\
+		{ NFSD4_CB_DOWN,	"DOWN" },			\
+		{ NFSD4_CB_FAULT,	"FAULT"})
+
+DECLARE_EVENT_CLASS(nfsd_cb_class,
+	TP_PROTO(const struct nfs4_client *clp),
+	TP_ARGS(clp),
+	TP_STRUCT__entry(
+		__field(unsigned long, state)
+		__field(u32, cl_boot)
+		__field(u32, cl_id)
+		__array(unsigned char, addr, sizeof(struct sockaddr_in6))
+	),
+	TP_fast_assign(
+		__entry->state = clp->cl_cb_state;
+		__entry->cl_boot = clp->cl_clientid.cl_boot;
+		__entry->cl_id = clp->cl_clientid.cl_id;
+		memcpy(__entry->addr, &clp->cl_cb_conn.cb_addr,
+			sizeof(struct sockaddr_in6));
+	),
+	TP_printk("addr=%pISpc client %08x:%08x state=%s",
+		__entry->addr, __entry->cl_boot, __entry->cl_id,
+		show_cb_state(__entry->state))
+);
+
+#define DEFINE_NFSD_CB_EVENT(name)			\
+DEFINE_EVENT(nfsd_cb_class, nfsd_cb_##name,		\
+	TP_PROTO(const struct nfs4_client *clp),	\
+	TP_ARGS(clp))
+
+DEFINE_NFSD_CB_EVENT(setup);
+DEFINE_NFSD_CB_EVENT(state);
+DEFINE_NFSD_CB_EVENT(shutdown);
+
+TRACE_EVENT(nfsd_cb_setup_err,
+	TP_PROTO(
+		const struct nfs4_client *clp,
+		long error
+	),
+	TP_ARGS(clp, error),
+	TP_STRUCT__entry(
+		__field(long, error)
+		__field(u32, cl_boot)
+		__field(u32, cl_id)
+		__array(unsigned char, addr, sizeof(struct sockaddr_in6))
+	),
+	TP_fast_assign(
+		__entry->error = error;
+		__entry->cl_boot = clp->cl_clientid.cl_boot;
+		__entry->cl_id = clp->cl_clientid.cl_id;
+		memcpy(__entry->addr, &clp->cl_cb_conn.cb_addr,
+			sizeof(struct sockaddr_in6));
+	),
+	TP_printk("addr=%pISpc client %08x:%08x error=%ld",
+		__entry->addr, __entry->cl_boot, __entry->cl_id, __entry->error)
+);
+
+TRACE_EVENT(nfsd_cb_work,
+	TP_PROTO(
+		const struct nfs4_client *clp,
+		const char *procedure
+	),
+	TP_ARGS(clp, procedure),
+	TP_STRUCT__entry(
+		__field(u32, cl_boot)
+		__field(u32, cl_id)
+		__string(procedure, procedure)
+		__array(unsigned char, addr, sizeof(struct sockaddr_in6))
+	),
+	TP_fast_assign(
+		__entry->cl_boot = clp->cl_clientid.cl_boot;
+		__entry->cl_id = clp->cl_clientid.cl_id;
+		__assign_str(procedure, procedure)
+		memcpy(__entry->addr, &clp->cl_cb_conn.cb_addr,
+			sizeof(struct sockaddr_in6));
+	),
+	TP_printk("addr=%pISpc client %08x:%08x procedure=%s",
+		__entry->addr, __entry->cl_boot, __entry->cl_id,
+		__get_str(procedure))
+);
+
+TRACE_EVENT(nfsd_cb_done,
+	TP_PROTO(
+		const struct nfs4_client *clp,
+		int status
+	),
+	TP_ARGS(clp, status),
+	TP_STRUCT__entry(
+		__field(u32, cl_boot)
+		__field(u32, cl_id)
+		__field(int, status)
+		__array(unsigned char, addr, sizeof(struct sockaddr_in6))
+	),
+	TP_fast_assign(
+		__entry->cl_boot = clp->cl_clientid.cl_boot;
+		__entry->cl_id = clp->cl_clientid.cl_id;
+		__entry->status = status;
+		memcpy(__entry->addr, &clp->cl_cb_conn.cb_addr,
+			sizeof(struct sockaddr_in6));
+	),
+	TP_printk("addr=%pISpc client %08x:%08x status=%d",
+		__entry->addr, __entry->cl_boot, __entry->cl_id,
+		__entry->status)
+);
+
+#endif /* _NFSD_TRACE_H */
+
+#undef TRACE_INCLUDE_PATH
+#define TRACE_INCLUDE_PATH .
+#define TRACE_INCLUDE_FILE trace
+#include <trace/define_trace.h>
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
new file mode 100644
index 000000000..31edb883a
--- /dev/null
+++ b/fs/nfsd/vfs.c
@@ -0,0 +1,2407 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * File operations used by nfsd. Some of these have been ripped from
+ * other parts of the kernel because they weren't exported, others
+ * are partial duplicates with added or changed functionality.
+ *
+ * Note that several functions dget() the dentry upon which they want
+ * to act, most notably those that create directory entries. Response
+ * dentry's are dput()'d if necessary in the release callback.
+ * So if you notice code paths that apparently fail to dput() the
+ * dentry, don't worry--they have been taken care of.
+ *
+ * Copyright (C) 1995-1999 Olaf Kirch <okir@monad.swb.de>
+ * Zerocpy NFS support (C) 2002 Hirokazu Takahashi <taka@valinux.co.jp>
+ */
+
+#include <linux/fs.h>
+#include <linux/file.h>
+#include <linux/splice.h>
+#include <linux/falloc.h>
+#include <linux/fcntl.h>
+#include <linux/namei.h>
+#include <linux/delay.h>
+#include <linux/fsnotify.h>
+#include <linux/posix_acl_xattr.h>
+#include <linux/xattr.h>
+#include <linux/jhash.h>
+#include <linux/ima.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <linux/exportfs.h>
+#include <linux/writeback.h>
+#include <linux/security.h>
+
+#ifdef CONFIG_NFSD_V3
+#include "xdr3.h"
+#endif /* CONFIG_NFSD_V3 */
+
+#ifdef CONFIG_NFSD_V4
+#include "../internal.h"
+#include "acl.h"
+#include "idmap.h"
+#endif /* CONFIG_NFSD_V4 */
+
+#include "nfsd.h"
+#include "vfs.h"
+#include "filecache.h"
+#include "trace.h"
+
+#define NFSDDBG_FACILITY		NFSDDBG_FILEOP
+
+/* 
+ * Called from nfsd_lookup and encode_dirent. Check if we have crossed 
+ * a mount point.
+ * Returns -EAGAIN or -ETIMEDOUT leaving *dpp and *expp unchanged,
+ *  or nfs_ok having possibly changed *dpp and *expp
+ */
+int
+nfsd_cross_mnt(struct svc_rqst *rqstp, struct dentry **dpp, 
+		        struct svc_export **expp)
+{
+	struct svc_export *exp = *expp, *exp2 = NULL;
+	struct dentry *dentry = *dpp;
+	struct path path = {.mnt = mntget(exp->ex_path.mnt),
+			    .dentry = dget(dentry)};
+	int err = 0;
+
+	err = follow_down(&path);
+	if (err < 0)
+		goto out;
+	if (path.mnt == exp->ex_path.mnt && path.dentry == dentry &&
+	    nfsd_mountpoint(dentry, exp) == 2) {
+		/* This is only a mountpoint in some other namespace */
+		path_put(&path);
+		goto out;
+	}
+
+	exp2 = rqst_exp_get_by_name(rqstp, &path);
+	if (IS_ERR(exp2)) {
+		err = PTR_ERR(exp2);
+		/*
+		 * We normally allow NFS clients to continue
+		 * "underneath" a mountpoint that is not exported.
+		 * The exception is V4ROOT, where no traversal is ever
+		 * allowed without an explicit export of the new
+		 * directory.
+		 */
+		if (err == -ENOENT && !(exp->ex_flags & NFSEXP_V4ROOT))
+			err = 0;
+		path_put(&path);
+		goto out;
+	}
+	if (nfsd_v4client(rqstp) ||
+		(exp->ex_flags & NFSEXP_CROSSMOUNT) || EX_NOHIDE(exp2)) {
+		/* successfully crossed mount point */
+		/*
+		 * This is subtle: path.dentry is *not* on path.mnt
+		 * at this point.  The only reason we are safe is that
+		 * original mnt is pinned down by exp, so we should
+		 * put path *before* putting exp
+		 */
+		*dpp = path.dentry;
+		path.dentry = dentry;
+		*expp = exp2;
+		exp2 = exp;
+	}
+	path_put(&path);
+	exp_put(exp2);
+out:
+	return err;
+}
+
+static void follow_to_parent(struct path *path)
+{
+	struct dentry *dp;
+
+	while (path->dentry == path->mnt->mnt_root && follow_up(path))
+		;
+	dp = dget_parent(path->dentry);
+	dput(path->dentry);
+	path->dentry = dp;
+}
+
+static int nfsd_lookup_parent(struct svc_rqst *rqstp, struct dentry *dparent, struct svc_export **exp, struct dentry **dentryp)
+{
+	struct svc_export *exp2;
+	struct path path = {.mnt = mntget((*exp)->ex_path.mnt),
+			    .dentry = dget(dparent)};
+
+	follow_to_parent(&path);
+
+	exp2 = rqst_exp_parent(rqstp, &path);
+	if (PTR_ERR(exp2) == -ENOENT) {
+		*dentryp = dget(dparent);
+	} else if (IS_ERR(exp2)) {
+		path_put(&path);
+		return PTR_ERR(exp2);
+	} else {
+		*dentryp = dget(path.dentry);
+		exp_put(*exp);
+		*exp = exp2;
+	}
+	path_put(&path);
+	return 0;
+}
+
+/*
+ * For nfsd purposes, we treat V4ROOT exports as though there was an
+ * export at *every* directory.
+ * We return:
+ * '1' if this dentry *must* be an export point,
+ * '2' if it might be, if there is really a mount here, and
+ * '0' if there is no chance of an export point here.
+ */
+int nfsd_mountpoint(struct dentry *dentry, struct svc_export *exp)
+{
+	if (!d_inode(dentry))
+		return 0;
+	if (exp->ex_flags & NFSEXP_V4ROOT)
+		return 1;
+	if (nfsd4_is_junction(dentry))
+		return 1;
+	if (d_mountpoint(dentry))
+		/*
+		 * Might only be a mountpoint in a different namespace,
+		 * but we need to check.
+		 */
+		return 2;
+	return 0;
+}
+
+__be32
+nfsd_lookup_dentry(struct svc_rqst *rqstp, struct svc_fh *fhp,
+		   const char *name, unsigned int len,
+		   struct svc_export **exp_ret, struct dentry **dentry_ret)
+{
+	struct svc_export	*exp;
+	struct dentry		*dparent;
+	struct dentry		*dentry;
+	int			host_err;
+
+	dprintk("nfsd: nfsd_lookup(fh %s, %.*s)\n", SVCFH_fmt(fhp), len,name);
+
+	dparent = fhp->fh_dentry;
+	exp = exp_get(fhp->fh_export);
+
+	/* Lookup the name, but don't follow links */
+	if (isdotent(name, len)) {
+		if (len==1)
+			dentry = dget(dparent);
+		else if (dparent != exp->ex_path.dentry)
+			dentry = dget_parent(dparent);
+		else if (!EX_NOHIDE(exp) && !nfsd_v4client(rqstp))
+			dentry = dget(dparent); /* .. == . just like at / */
+		else {
+			/* checking mountpoint crossing is very different when stepping up */
+			host_err = nfsd_lookup_parent(rqstp, dparent, &exp, &dentry);
+			if (host_err)
+				goto out_nfserr;
+		}
+	} else {
+		/*
+		 * In the nfsd4_open() case, this may be held across
+		 * subsequent open and delegation acquisition which may
+		 * need to take the child's i_mutex:
+		 */
+		fh_lock_nested(fhp, I_MUTEX_PARENT);
+		dentry = lookup_one_len(name, dparent, len);
+		host_err = PTR_ERR(dentry);
+		if (IS_ERR(dentry))
+			goto out_nfserr;
+		if (nfsd_mountpoint(dentry, exp)) {
+			/*
+			 * We don't need the i_mutex after all.  It's
+			 * still possible we could open this (regular
+			 * files can be mountpoints too), but the
+			 * i_mutex is just there to prevent renames of
+			 * something that we might be about to delegate,
+			 * and a mountpoint won't be renamed:
+			 */
+			fh_unlock(fhp);
+			if ((host_err = nfsd_cross_mnt(rqstp, &dentry, &exp))) {
+				dput(dentry);
+				goto out_nfserr;
+			}
+		}
+	}
+	*dentry_ret = dentry;
+	*exp_ret = exp;
+	return 0;
+
+out_nfserr:
+	exp_put(exp);
+	return nfserrno(host_err);
+}
+
+/*
+ * Look up one component of a pathname.
+ * N.B. After this call _both_ fhp and resfh need an fh_put
+ *
+ * If the lookup would cross a mountpoint, and the mounted filesystem
+ * is exported to the client with NFSEXP_NOHIDE, then the lookup is
+ * accepted as it stands and the mounted directory is
+ * returned. Otherwise the covered directory is returned.
+ * NOTE: this mountpoint crossing is not supported properly by all
+ *   clients and is explicitly disallowed for NFSv3
+ *      NeilBrown <neilb@cse.unsw.edu.au>
+ */
+__be32
+nfsd_lookup(struct svc_rqst *rqstp, struct svc_fh *fhp, const char *name,
+				unsigned int len, struct svc_fh *resfh)
+{
+	struct svc_export	*exp;
+	struct dentry		*dentry;
+	__be32 err;
+
+	err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_EXEC);
+	if (err)
+		return err;
+	err = nfsd_lookup_dentry(rqstp, fhp, name, len, &exp, &dentry);
+	if (err)
+		return err;
+	err = check_nfsd_access(exp, rqstp);
+	if (err)
+		goto out;
+	/*
+	 * Note: we compose the file handle now, but as the
+	 * dentry may be negative, it may need to be updated.
+	 */
+	err = fh_compose(resfh, exp, dentry, fhp);
+	if (!err && d_really_is_negative(dentry))
+		err = nfserr_noent;
+out:
+	dput(dentry);
+	exp_put(exp);
+	return err;
+}
+
+/*
+ * Commit metadata changes to stable storage.
+ */
+static int
+commit_inode_metadata(struct inode *inode)
+{
+	const struct export_operations *export_ops = inode->i_sb->s_export_op;
+
+	if (export_ops->commit_metadata)
+		return export_ops->commit_metadata(inode);
+	return sync_inode_metadata(inode, 1);
+}
+
+static int
+commit_metadata(struct svc_fh *fhp)
+{
+	struct inode *inode = d_inode(fhp->fh_dentry);
+
+	if (!EX_ISSYNC(fhp->fh_export))
+		return 0;
+	return commit_inode_metadata(inode);
+}
+
+/*
+ * Go over the attributes and take care of the small differences between
+ * NFS semantics and what Linux expects.
+ */
+static void
+nfsd_sanitize_attrs(struct inode *inode, struct iattr *iap)
+{
+	/* sanitize the mode change */
+	if (iap->ia_valid & ATTR_MODE) {
+		iap->ia_mode &= S_IALLUGO;
+		iap->ia_mode |= (inode->i_mode & ~S_IALLUGO);
+	}
+
+	/* Revoke setuid/setgid on chown */
+	if (!S_ISDIR(inode->i_mode) &&
+	    ((iap->ia_valid & ATTR_UID) || (iap->ia_valid & ATTR_GID))) {
+		iap->ia_valid |= ATTR_KILL_PRIV;
+		if (iap->ia_valid & ATTR_MODE) {
+			/* we're setting mode too, just clear the s*id bits */
+			iap->ia_mode &= ~S_ISUID;
+			if (iap->ia_mode & S_IXGRP)
+				iap->ia_mode &= ~S_ISGID;
+		} else {
+			/* set ATTR_KILL_* bits and let VFS handle it */
+			iap->ia_valid |= (ATTR_KILL_SUID | ATTR_KILL_SGID);
+		}
+	}
+}
+
+static __be32
+nfsd_get_write_access(struct svc_rqst *rqstp, struct svc_fh *fhp,
+		struct iattr *iap)
+{
+	struct inode *inode = d_inode(fhp->fh_dentry);
+	int host_err;
+
+	if (iap->ia_size < inode->i_size) {
+		__be32 err;
+
+		err = nfsd_permission(rqstp, fhp->fh_export, fhp->fh_dentry,
+				NFSD_MAY_TRUNC | NFSD_MAY_OWNER_OVERRIDE);
+		if (err)
+			return err;
+	}
+
+	host_err = get_write_access(inode);
+	if (host_err)
+		goto out_nfserrno;
+
+	host_err = locks_verify_truncate(inode, NULL, iap->ia_size);
+	if (host_err)
+		goto out_put_write_access;
+	return 0;
+
+out_put_write_access:
+	put_write_access(inode);
+out_nfserrno:
+	return nfserrno(host_err);
+}
+
+/*
+ * Set various file attributes.  After this call fhp needs an fh_put.
+ */
+__be32
+nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, struct iattr *iap,
+	     int check_guard, time64_t guardtime)
+{
+	struct dentry	*dentry;
+	struct inode	*inode;
+	int		accmode = NFSD_MAY_SATTR;
+	umode_t		ftype = 0;
+	__be32		err;
+	int		host_err;
+	bool		get_write_count;
+	bool		size_change = (iap->ia_valid & ATTR_SIZE);
+
+	if (iap->ia_valid & ATTR_SIZE) {
+		accmode |= NFSD_MAY_WRITE|NFSD_MAY_OWNER_OVERRIDE;
+		ftype = S_IFREG;
+	}
+
+	/*
+	 * If utimes(2) and friends are called with times not NULL, we should
+	 * not set NFSD_MAY_WRITE bit. Otherwise fh_verify->nfsd_permission
+	 * will return EACCES, when the caller's effective UID does not match
+	 * the owner of the file, and the caller is not privileged. In this
+	 * situation, we should return EPERM(notify_change will return this).
+	 */
+	if (iap->ia_valid & (ATTR_ATIME | ATTR_MTIME)) {
+		accmode |= NFSD_MAY_OWNER_OVERRIDE;
+		if (!(iap->ia_valid & (ATTR_ATIME_SET | ATTR_MTIME_SET)))
+			accmode |= NFSD_MAY_WRITE;
+	}
+
+	/* Callers that do fh_verify should do the fh_want_write: */
+	get_write_count = !fhp->fh_dentry;
+
+	/* Get inode */
+	err = fh_verify(rqstp, fhp, ftype, accmode);
+	if (err)
+		return err;
+	if (get_write_count) {
+		host_err = fh_want_write(fhp);
+		if (host_err)
+			goto out;
+	}
+
+	dentry = fhp->fh_dentry;
+	inode = d_inode(dentry);
+
+	/* Ignore any mode updates on symlinks */
+	if (S_ISLNK(inode->i_mode))
+		iap->ia_valid &= ~ATTR_MODE;
+
+	if (!iap->ia_valid)
+		return 0;
+
+	nfsd_sanitize_attrs(inode, iap);
+
+	if (check_guard && guardtime != inode->i_ctime.tv_sec)
+		return nfserr_notsync;
+
+	/*
+	 * The size case is special, it changes the file in addition to the
+	 * attributes, and file systems don't expect it to be mixed with
+	 * "random" attribute changes.  We thus split out the size change
+	 * into a separate call to ->setattr, and do the rest as a separate
+	 * setattr call.
+	 */
+	if (size_change) {
+		err = nfsd_get_write_access(rqstp, fhp, iap);
+		if (err)
+			return err;
+	}
+
+	fh_lock(fhp);
+	if (size_change) {
+		/*
+		 * RFC5661, Section 18.30.4:
+		 *   Changing the size of a file with SETATTR indirectly
+		 *   changes the time_modify and change attributes.
+		 *
+		 * (and similar for the older RFCs)
+		 */
+		struct iattr size_attr = {
+			.ia_valid	= ATTR_SIZE | ATTR_CTIME | ATTR_MTIME,
+			.ia_size	= iap->ia_size,
+		};
+
+		host_err = notify_change(dentry, &size_attr, NULL);
+		if (host_err)
+			goto out_unlock;
+		iap->ia_valid &= ~ATTR_SIZE;
+
+		/*
+		 * Avoid the additional setattr call below if the only other
+		 * attribute that the client sends is the mtime, as we update
+		 * it as part of the size change above.
+		 */
+		if ((iap->ia_valid & ~ATTR_MTIME) == 0)
+			goto out_unlock;
+	}
+
+	iap->ia_valid |= ATTR_CTIME;
+	host_err = notify_change(dentry, iap, NULL);
+
+out_unlock:
+	fh_unlock(fhp);
+	if (size_change)
+		put_write_access(inode);
+out:
+	if (!host_err)
+		host_err = commit_metadata(fhp);
+	return nfserrno(host_err);
+}
+
+#if defined(CONFIG_NFSD_V4)
+/*
+ * NFS junction information is stored in an extended attribute.
+ */
+#define NFSD_JUNCTION_XATTR_NAME	XATTR_TRUSTED_PREFIX "junction.nfs"
+
+/**
+ * nfsd4_is_junction - Test if an object could be an NFS junction
+ *
+ * @dentry: object to test
+ *
+ * Returns 1 if "dentry" appears to contain NFS junction information.
+ * Otherwise 0 is returned.
+ */
+int nfsd4_is_junction(struct dentry *dentry)
+{
+	struct inode *inode = d_inode(dentry);
+
+	if (inode == NULL)
+		return 0;
+	if (inode->i_mode & S_IXUGO)
+		return 0;
+	if (!(inode->i_mode & S_ISVTX))
+		return 0;
+	if (vfs_getxattr(dentry, NFSD_JUNCTION_XATTR_NAME, NULL, 0) <= 0)
+		return 0;
+	return 1;
+}
+#ifdef CONFIG_NFSD_V4_SECURITY_LABEL
+__be32 nfsd4_set_nfs4_label(struct svc_rqst *rqstp, struct svc_fh *fhp,
+		struct xdr_netobj *label)
+{
+	__be32 error;
+	int host_error;
+	struct dentry *dentry;
+
+	error = fh_verify(rqstp, fhp, 0 /* S_IFREG */, NFSD_MAY_SATTR);
+	if (error)
+		return error;
+
+	dentry = fhp->fh_dentry;
+
+	inode_lock(d_inode(dentry));
+	host_error = security_inode_setsecctx(dentry, label->data, label->len);
+	inode_unlock(d_inode(dentry));
+	return nfserrno(host_error);
+}
+#else
+__be32 nfsd4_set_nfs4_label(struct svc_rqst *rqstp, struct svc_fh *fhp,
+		struct xdr_netobj *label)
+{
+	return nfserr_notsupp;
+}
+#endif
+
+__be32 nfsd4_clone_file_range(struct nfsd_file *nf_src, u64 src_pos,
+		struct nfsd_file *nf_dst, u64 dst_pos, u64 count, bool sync)
+{
+	struct file *src = nf_src->nf_file;
+	struct file *dst = nf_dst->nf_file;
+	errseq_t since;
+	loff_t cloned;
+	__be32 ret = 0;
+
+	since = READ_ONCE(dst->f_wb_err);
+	cloned = vfs_clone_file_range(src, src_pos, dst, dst_pos, count, 0);
+	if (cloned < 0) {
+		ret = nfserrno(cloned);
+		goto out_err;
+	}
+	if (count && cloned != count) {
+		ret = nfserrno(-EINVAL);
+		goto out_err;
+	}
+	if (sync) {
+		loff_t dst_end = count ? dst_pos + count - 1 : LLONG_MAX;
+		int status = vfs_fsync_range(dst, dst_pos, dst_end, 0);
+
+		if (!status)
+			status = filemap_check_wb_err(dst->f_mapping, since);
+		if (!status)
+			status = commit_inode_metadata(file_inode(src));
+		if (status < 0) {
+			nfsd_reset_boot_verifier(net_generic(nf_dst->nf_net,
+						 nfsd_net_id));
+			ret = nfserrno(status);
+		}
+	}
+out_err:
+	return ret;
+}
+
+ssize_t nfsd_copy_file_range(struct file *src, u64 src_pos, struct file *dst,
+			     u64 dst_pos, u64 count)
+{
+	ssize_t ret;
+
+	/*
+	 * Limit copy to 4MB to prevent indefinitely blocking an nfsd
+	 * thread and client rpc slot.  The choice of 4MB is somewhat
+	 * arbitrary.  We might instead base this on r/wsize, or make it
+	 * tunable, or use a time instead of a byte limit, or implement
+	 * asynchronous copy.  In theory a client could also recognize a
+	 * limit like this and pipeline multiple COPY requests.
+	 */
+	count = min_t(u64, count, 1 << 22);
+	ret = vfs_copy_file_range(src, src_pos, dst, dst_pos, count, 0);
+
+	if (ret == -EOPNOTSUPP || ret == -EXDEV)
+		ret = vfs_copy_file_range(src, src_pos, dst, dst_pos, count,
+					  COPY_FILE_SPLICE);
+	return ret;
+}
+
+__be32 nfsd4_vfs_fallocate(struct svc_rqst *rqstp, struct svc_fh *fhp,
+			   struct file *file, loff_t offset, loff_t len,
+			   int flags)
+{
+	int error;
+
+	if (!S_ISREG(file_inode(file)->i_mode))
+		return nfserr_inval;
+
+	error = vfs_fallocate(file, flags, offset, len);
+	if (!error)
+		error = commit_metadata(fhp);
+
+	return nfserrno(error);
+}
+#endif /* defined(CONFIG_NFSD_V4) */
+
+#ifdef CONFIG_NFSD_V3
+/*
+ * Check server access rights to a file system object
+ */
+struct accessmap {
+	u32		access;
+	int		how;
+};
+static struct accessmap	nfs3_regaccess[] = {
+    {	NFS3_ACCESS_READ,	NFSD_MAY_READ			},
+    {	NFS3_ACCESS_EXECUTE,	NFSD_MAY_EXEC			},
+    {	NFS3_ACCESS_MODIFY,	NFSD_MAY_WRITE|NFSD_MAY_TRUNC	},
+    {	NFS3_ACCESS_EXTEND,	NFSD_MAY_WRITE			},
+
+#ifdef CONFIG_NFSD_V4
+    {	NFS4_ACCESS_XAREAD,	NFSD_MAY_READ			},
+    {	NFS4_ACCESS_XAWRITE,	NFSD_MAY_WRITE			},
+    {	NFS4_ACCESS_XALIST,	NFSD_MAY_READ			},
+#endif
+
+    {	0,			0				}
+};
+
+static struct accessmap	nfs3_diraccess[] = {
+    {	NFS3_ACCESS_READ,	NFSD_MAY_READ			},
+    {	NFS3_ACCESS_LOOKUP,	NFSD_MAY_EXEC			},
+    {	NFS3_ACCESS_MODIFY,	NFSD_MAY_EXEC|NFSD_MAY_WRITE|NFSD_MAY_TRUNC},
+    {	NFS3_ACCESS_EXTEND,	NFSD_MAY_EXEC|NFSD_MAY_WRITE	},
+    {	NFS3_ACCESS_DELETE,	NFSD_MAY_REMOVE			},
+
+#ifdef CONFIG_NFSD_V4
+    {	NFS4_ACCESS_XAREAD,	NFSD_MAY_READ			},
+    {	NFS4_ACCESS_XAWRITE,	NFSD_MAY_WRITE			},
+    {	NFS4_ACCESS_XALIST,	NFSD_MAY_READ			},
+#endif
+
+    {	0,			0				}
+};
+
+static struct accessmap	nfs3_anyaccess[] = {
+	/* Some clients - Solaris 2.6 at least, make an access call
+	 * to the server to check for access for things like /dev/null
+	 * (which really, the server doesn't care about).  So
+	 * We provide simple access checking for them, looking
+	 * mainly at mode bits, and we make sure to ignore read-only
+	 * filesystem checks
+	 */
+    {	NFS3_ACCESS_READ,	NFSD_MAY_READ			},
+    {	NFS3_ACCESS_EXECUTE,	NFSD_MAY_EXEC			},
+    {	NFS3_ACCESS_MODIFY,	NFSD_MAY_WRITE|NFSD_MAY_LOCAL_ACCESS	},
+    {	NFS3_ACCESS_EXTEND,	NFSD_MAY_WRITE|NFSD_MAY_LOCAL_ACCESS	},
+
+    {	0,			0				}
+};
+
+__be32
+nfsd_access(struct svc_rqst *rqstp, struct svc_fh *fhp, u32 *access, u32 *supported)
+{
+	struct accessmap	*map;
+	struct svc_export	*export;
+	struct dentry		*dentry;
+	u32			query, result = 0, sresult = 0;
+	__be32			error;
+
+	error = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP);
+	if (error)
+		goto out;
+
+	export = fhp->fh_export;
+	dentry = fhp->fh_dentry;
+
+	if (d_is_reg(dentry))
+		map = nfs3_regaccess;
+	else if (d_is_dir(dentry))
+		map = nfs3_diraccess;
+	else
+		map = nfs3_anyaccess;
+
+
+	query = *access;
+	for  (; map->access; map++) {
+		if (map->access & query) {
+			__be32 err2;
+
+			sresult |= map->access;
+
+			err2 = nfsd_permission(rqstp, export, dentry, map->how);
+			switch (err2) {
+			case nfs_ok:
+				result |= map->access;
+				break;
+				
+			/* the following error codes just mean the access was not allowed,
+			 * rather than an error occurred */
+			case nfserr_rofs:
+			case nfserr_acces:
+			case nfserr_perm:
+				/* simply don't "or" in the access bit. */
+				break;
+			default:
+				error = err2;
+				goto out;
+			}
+		}
+	}
+	*access = result;
+	if (supported)
+		*supported = sresult;
+
+ out:
+	return error;
+}
+#endif /* CONFIG_NFSD_V3 */
+
+int nfsd_open_break_lease(struct inode *inode, int access)
+{
+	unsigned int mode;
+
+	if (access & NFSD_MAY_NOT_BREAK_LEASE)
+		return 0;
+	mode = (access & NFSD_MAY_WRITE) ? O_WRONLY : O_RDONLY;
+	return break_lease(inode, mode | O_NONBLOCK);
+}
+
+/*
+ * Open an existing file or directory.
+ * The may_flags argument indicates the type of open (read/write/lock)
+ * and additional flags.
+ * N.B. After this call fhp needs an fh_put
+ */
+static __be32
+__nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type,
+			int may_flags, struct file **filp)
+{
+	struct path	path;
+	struct inode	*inode;
+	struct file	*file;
+	int		flags = O_RDONLY|O_LARGEFILE;
+	__be32		err;
+	int		host_err = 0;
+
+	path.mnt = fhp->fh_export->ex_path.mnt;
+	path.dentry = fhp->fh_dentry;
+	inode = d_inode(path.dentry);
+
+	/* Disallow write access to files with the append-only bit set
+	 * or any access when mandatory locking enabled
+	 */
+	err = nfserr_perm;
+	if (IS_APPEND(inode) && (may_flags & NFSD_MAY_WRITE))
+		goto out;
+	/*
+	 * We must ignore files (but only files) which might have mandatory
+	 * locks on them because there is no way to know if the accesser has
+	 * the lock.
+	 */
+	if (S_ISREG((inode)->i_mode) && mandatory_lock(inode))
+		goto out;
+
+	if (!inode->i_fop)
+		goto out;
+
+	host_err = nfsd_open_break_lease(inode, may_flags);
+	if (host_err) /* NOMEM or WOULDBLOCK */
+		goto out_nfserr;
+
+	if (may_flags & NFSD_MAY_WRITE) {
+		if (may_flags & NFSD_MAY_READ)
+			flags = O_RDWR|O_LARGEFILE;
+		else
+			flags = O_WRONLY|O_LARGEFILE;
+	}
+
+	file = dentry_open(&path, flags, current_cred());
+	if (IS_ERR(file)) {
+		host_err = PTR_ERR(file);
+		goto out_nfserr;
+	}
+
+	host_err = ima_file_check(file, may_flags);
+	if (host_err) {
+		fput(file);
+		goto out_nfserr;
+	}
+
+	if (may_flags & NFSD_MAY_64BIT_COOKIE)
+		file->f_mode |= FMODE_64BITHASH;
+	else
+		file->f_mode |= FMODE_32BITHASH;
+
+	*filp = file;
+out_nfserr:
+	err = nfserrno(host_err);
+out:
+	return err;
+}
+
+__be32
+nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type,
+		int may_flags, struct file **filp)
+{
+	__be32 err;
+
+	validate_process_creds();
+	/*
+	 * If we get here, then the client has already done an "open",
+	 * and (hopefully) checked permission - so allow OWNER_OVERRIDE
+	 * in case a chmod has now revoked permission.
+	 *
+	 * Arguably we should also allow the owner override for
+	 * directories, but we never have and it doesn't seem to have
+	 * caused anyone a problem.  If we were to change this, note
+	 * also that our filldir callbacks would need a variant of
+	 * lookup_one_len that doesn't check permissions.
+	 */
+	if (type == S_IFREG)
+		may_flags |= NFSD_MAY_OWNER_OVERRIDE;
+	err = fh_verify(rqstp, fhp, type, may_flags);
+	if (!err)
+		err = __nfsd_open(rqstp, fhp, type, may_flags, filp);
+	validate_process_creds();
+	return err;
+}
+
+__be32
+nfsd_open_verified(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type,
+		int may_flags, struct file **filp)
+{
+	__be32 err;
+
+	validate_process_creds();
+	err = __nfsd_open(rqstp, fhp, type, may_flags, filp);
+	validate_process_creds();
+	return err;
+}
+
+/*
+ * Grab and keep cached pages associated with a file in the svc_rqst
+ * so that they can be passed to the network sendmsg/sendpage routines
+ * directly. They will be released after the sending has completed.
+ */
+static int
+nfsd_splice_actor(struct pipe_inode_info *pipe, struct pipe_buffer *buf,
+		  struct splice_desc *sd)
+{
+	struct svc_rqst *rqstp = sd->u.data;
+	struct page **pp = rqstp->rq_next_page;
+	struct page *page = buf->page;
+	size_t size;
+
+	size = sd->len;
+
+	if (rqstp->rq_res.page_len == 0) {
+		get_page(page);
+		put_page(*rqstp->rq_next_page);
+		*(rqstp->rq_next_page++) = page;
+		rqstp->rq_res.page_base = buf->offset;
+		rqstp->rq_res.page_len = size;
+	} else if (page != pp[-1]) {
+		get_page(page);
+		if (*rqstp->rq_next_page)
+			put_page(*rqstp->rq_next_page);
+		*(rqstp->rq_next_page++) = page;
+		rqstp->rq_res.page_len += size;
+	} else
+		rqstp->rq_res.page_len += size;
+
+	return size;
+}
+
+static int nfsd_direct_splice_actor(struct pipe_inode_info *pipe,
+				    struct splice_desc *sd)
+{
+	return __splice_from_pipe(pipe, sd, nfsd_splice_actor);
+}
+
+static u32 nfsd_eof_on_read(struct file *file, loff_t offset, ssize_t len,
+		size_t expected)
+{
+	if (expected != 0 && len == 0)
+		return 1;
+	if (offset+len >= i_size_read(file_inode(file)))
+		return 1;
+	return 0;
+}
+
+static __be32 nfsd_finish_read(struct svc_rqst *rqstp, struct svc_fh *fhp,
+			       struct file *file, loff_t offset,
+			       unsigned long *count, u32 *eof, ssize_t host_err)
+{
+	if (host_err >= 0) {
+		nfsdstats.io_read += host_err;
+		*eof = nfsd_eof_on_read(file, offset, host_err, *count);
+		*count = host_err;
+		fsnotify_access(file);
+		trace_nfsd_read_io_done(rqstp, fhp, offset, *count);
+		return 0;
+	} else {
+		trace_nfsd_read_err(rqstp, fhp, offset, host_err);
+		return nfserrno(host_err);
+	}
+}
+
+__be32 nfsd_splice_read(struct svc_rqst *rqstp, struct svc_fh *fhp,
+			struct file *file, loff_t offset, unsigned long *count,
+			u32 *eof)
+{
+	struct splice_desc sd = {
+		.len		= 0,
+		.total_len	= *count,
+		.pos		= offset,
+		.u.data		= rqstp,
+	};
+	ssize_t host_err;
+
+	trace_nfsd_read_splice(rqstp, fhp, offset, *count);
+	rqstp->rq_next_page = rqstp->rq_respages + 1;
+	host_err = splice_direct_to_actor(file, &sd, nfsd_direct_splice_actor);
+	return nfsd_finish_read(rqstp, fhp, file, offset, count, eof, host_err);
+}
+
+__be32 nfsd_readv(struct svc_rqst *rqstp, struct svc_fh *fhp,
+		  struct file *file, loff_t offset,
+		  struct kvec *vec, int vlen, unsigned long *count,
+		  u32 *eof)
+{
+	struct iov_iter iter;
+	loff_t ppos = offset;
+	ssize_t host_err;
+
+	trace_nfsd_read_vector(rqstp, fhp, offset, *count);
+	iov_iter_kvec(&iter, READ, vec, vlen, *count);
+	host_err = vfs_iter_read(file, &iter, &ppos, 0);
+	return nfsd_finish_read(rqstp, fhp, file, offset, count, eof, host_err);
+}
+
+/*
+ * Gathered writes: If another process is currently writing to the file,
+ * there's a high chance this is another nfsd (triggered by a bulk write
+ * from a client's biod). Rather than syncing the file with each write
+ * request, we sleep for 10 msec.
+ *
+ * I don't know if this roughly approximates C. Juszak's idea of
+ * gathered writes, but it's a nice and simple solution (IMHO), and it
+ * seems to work:-)
+ *
+ * Note: we do this only in the NFSv2 case, since v3 and higher have a
+ * better tool (separate unstable writes and commits) for solving this
+ * problem.
+ */
+static int wait_for_concurrent_writes(struct file *file)
+{
+	struct inode *inode = file_inode(file);
+	static ino_t last_ino;
+	static dev_t last_dev;
+	int err = 0;
+
+	if (atomic_read(&inode->i_writecount) > 1
+	    || (last_ino == inode->i_ino && last_dev == inode->i_sb->s_dev)) {
+		dprintk("nfsd: write defer %d\n", task_pid_nr(current));
+		msleep(10);
+		dprintk("nfsd: write resume %d\n", task_pid_nr(current));
+	}
+
+	if (inode->i_state & I_DIRTY) {
+		dprintk("nfsd: write sync %d\n", task_pid_nr(current));
+		err = vfs_fsync(file, 0);
+	}
+	last_ino = inode->i_ino;
+	last_dev = inode->i_sb->s_dev;
+	return err;
+}
+
+__be32
+nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct nfsd_file *nf,
+				loff_t offset, struct kvec *vec, int vlen,
+				unsigned long *cnt, int stable,
+				__be32 *verf)
+{
+	struct file		*file = nf->nf_file;
+	struct svc_export	*exp;
+	struct iov_iter		iter;
+	errseq_t		since;
+	__be32			nfserr;
+	int			host_err;
+	int			use_wgather;
+	loff_t			pos = offset;
+	unsigned int		pflags = current->flags;
+	rwf_t			flags = 0;
+
+	trace_nfsd_write_opened(rqstp, fhp, offset, *cnt);
+
+	if (test_bit(RQ_LOCAL, &rqstp->rq_flags))
+		/*
+		 * We want throttling in balance_dirty_pages()
+		 * and shrink_inactive_list() to only consider
+		 * the backingdev we are writing to, so that nfs to
+		 * localhost doesn't cause nfsd to lock up due to all
+		 * the client's dirty pages or its congested queue.
+		 */
+		current->flags |= PF_LOCAL_THROTTLE;
+
+	exp = fhp->fh_export;
+	use_wgather = (rqstp->rq_vers == 2) && EX_WGATHER(exp);
+
+	if (!EX_ISSYNC(exp))
+		stable = NFS_UNSTABLE;
+
+	if (stable && !use_wgather)
+		flags |= RWF_SYNC;
+
+	iov_iter_kvec(&iter, WRITE, vec, vlen, *cnt);
+	since = READ_ONCE(file->f_wb_err);
+	if (flags & RWF_SYNC) {
+		if (verf)
+			nfsd_copy_boot_verifier(verf,
+					net_generic(SVC_NET(rqstp),
+					nfsd_net_id));
+		host_err = vfs_iter_write(file, &iter, &pos, flags);
+		if (host_err < 0)
+			nfsd_reset_boot_verifier(net_generic(SVC_NET(rqstp),
+						 nfsd_net_id));
+	} else {
+		if (verf)
+			nfsd_copy_boot_verifier(verf,
+					net_generic(SVC_NET(rqstp),
+					nfsd_net_id));
+		host_err = vfs_iter_write(file, &iter, &pos, flags);
+	}
+	if (host_err < 0) {
+		nfsd_reset_boot_verifier(net_generic(SVC_NET(rqstp),
+					 nfsd_net_id));
+		goto out_nfserr;
+	}
+	*cnt = host_err;
+	nfsdstats.io_write += *cnt;
+	fsnotify_modify(file);
+	host_err = filemap_check_wb_err(file->f_mapping, since);
+	if (host_err < 0)
+		goto out_nfserr;
+
+	if (stable && use_wgather) {
+		host_err = wait_for_concurrent_writes(file);
+		if (host_err < 0)
+			nfsd_reset_boot_verifier(net_generic(SVC_NET(rqstp),
+						 nfsd_net_id));
+	}
+
+out_nfserr:
+	if (host_err >= 0) {
+		trace_nfsd_write_io_done(rqstp, fhp, offset, *cnt);
+		nfserr = nfs_ok;
+	} else {
+		trace_nfsd_write_err(rqstp, fhp, offset, host_err);
+		nfserr = nfserrno(host_err);
+	}
+	if (test_bit(RQ_LOCAL, &rqstp->rq_flags))
+		current_restore_flags(pflags, PF_LOCAL_THROTTLE);
+	return nfserr;
+}
+
+/*
+ * Read data from a file. count must contain the requested read count
+ * on entry. On return, *count contains the number of bytes actually read.
+ * N.B. After this call fhp needs an fh_put
+ */
+__be32 nfsd_read(struct svc_rqst *rqstp, struct svc_fh *fhp,
+	loff_t offset, struct kvec *vec, int vlen, unsigned long *count,
+	u32 *eof)
+{
+	struct nfsd_file	*nf;
+	struct file *file;
+	__be32 err;
+
+	trace_nfsd_read_start(rqstp, fhp, offset, *count);
+	err = nfsd_file_acquire(rqstp, fhp, NFSD_MAY_READ, &nf);
+	if (err)
+		return err;
+
+	file = nf->nf_file;
+	if (file->f_op->splice_read && test_bit(RQ_SPLICE_OK, &rqstp->rq_flags))
+		err = nfsd_splice_read(rqstp, fhp, file, offset, count, eof);
+	else
+		err = nfsd_readv(rqstp, fhp, file, offset, vec, vlen, count, eof);
+
+	nfsd_file_put(nf);
+
+	trace_nfsd_read_done(rqstp, fhp, offset, *count);
+
+	return err;
+}
+
+/*
+ * Write data to a file.
+ * The stable flag requests synchronous writes.
+ * N.B. After this call fhp needs an fh_put
+ */
+__be32
+nfsd_write(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t offset,
+	   struct kvec *vec, int vlen, unsigned long *cnt, int stable,
+	   __be32 *verf)
+{
+	struct nfsd_file *nf;
+	__be32 err;
+
+	trace_nfsd_write_start(rqstp, fhp, offset, *cnt);
+
+	err = nfsd_file_acquire(rqstp, fhp, NFSD_MAY_WRITE, &nf);
+	if (err)
+		goto out;
+
+	err = nfsd_vfs_write(rqstp, fhp, nf, offset, vec,
+			vlen, cnt, stable, verf);
+	nfsd_file_put(nf);
+out:
+	trace_nfsd_write_done(rqstp, fhp, offset, *cnt);
+	return err;
+}
+
+#ifdef CONFIG_NFSD_V3
+/*
+ * Commit all pending writes to stable storage.
+ *
+ * Note: we only guarantee that data that lies within the range specified
+ * by the 'offset' and 'count' parameters will be synced.
+ *
+ * Unfortunately we cannot lock the file to make sure we return full WCC
+ * data to the client, as locking happens lower down in the filesystem.
+ */
+__be32
+nfsd_commit(struct svc_rqst *rqstp, struct svc_fh *fhp,
+               loff_t offset, unsigned long count, __be32 *verf)
+{
+	struct nfsd_file	*nf;
+	loff_t			end = LLONG_MAX;
+	__be32			err = nfserr_inval;
+
+	if (offset < 0)
+		goto out;
+	if (count != 0) {
+		end = offset + (loff_t)count - 1;
+		if (end < offset)
+			goto out;
+	}
+
+	err = nfsd_file_acquire(rqstp, fhp,
+			NFSD_MAY_WRITE|NFSD_MAY_NOT_BREAK_LEASE, &nf);
+	if (err)
+		goto out;
+	if (EX_ISSYNC(fhp->fh_export)) {
+		errseq_t since = READ_ONCE(nf->nf_file->f_wb_err);
+		int err2;
+
+		err2 = vfs_fsync_range(nf->nf_file, offset, end, 0);
+		switch (err2) {
+		case 0:
+			nfsd_copy_boot_verifier(verf, net_generic(nf->nf_net,
+						nfsd_net_id));
+			err2 = filemap_check_wb_err(nf->nf_file->f_mapping,
+						    since);
+			err = nfserrno(err2);
+			break;
+		case -EINVAL:
+			err = nfserr_notsupp;
+			break;
+		default:
+			nfsd_reset_boot_verifier(net_generic(nf->nf_net,
+						 nfsd_net_id));
+			err = nfserrno(err2);
+		}
+	} else
+		nfsd_copy_boot_verifier(verf, net_generic(nf->nf_net,
+					nfsd_net_id));
+
+	nfsd_file_put(nf);
+out:
+	return err;
+}
+#endif /* CONFIG_NFSD_V3 */
+
+static __be32
+nfsd_create_setattr(struct svc_rqst *rqstp, struct svc_fh *resfhp,
+			struct iattr *iap)
+{
+	/*
+	 * Mode has already been set earlier in create:
+	 */
+	iap->ia_valid &= ~ATTR_MODE;
+	/*
+	 * Setting uid/gid works only for root.  Irix appears to
+	 * send along the gid on create when it tries to implement
+	 * setgid directories via NFS:
+	 */
+	if (!uid_eq(current_fsuid(), GLOBAL_ROOT_UID))
+		iap->ia_valid &= ~(ATTR_UID|ATTR_GID);
+	if (iap->ia_valid)
+		return nfsd_setattr(rqstp, resfhp, iap, 0, (time64_t)0);
+	/* Callers expect file metadata to be committed here */
+	return nfserrno(commit_metadata(resfhp));
+}
+
+/* HPUX client sometimes creates a file in mode 000, and sets size to 0.
+ * setting size to 0 may fail for some specific file systems by the permission
+ * checking which requires WRITE permission but the mode is 000.
+ * we ignore the resizing(to 0) on the just new created file, since the size is
+ * 0 after file created.
+ *
+ * call this only after vfs_create() is called.
+ * */
+static void
+nfsd_check_ignore_resizing(struct iattr *iap)
+{
+	if ((iap->ia_valid & ATTR_SIZE) && (iap->ia_size == 0))
+		iap->ia_valid &= ~ATTR_SIZE;
+}
+
+/* The parent directory should already be locked: */
+__be32
+nfsd_create_locked(struct svc_rqst *rqstp, struct svc_fh *fhp,
+		char *fname, int flen, struct iattr *iap,
+		int type, dev_t rdev, struct svc_fh *resfhp)
+{
+	struct dentry	*dentry, *dchild;
+	struct inode	*dirp;
+	__be32		err;
+	__be32		err2;
+	int		host_err;
+
+	dentry = fhp->fh_dentry;
+	dirp = d_inode(dentry);
+
+	dchild = dget(resfhp->fh_dentry);
+	if (!fhp->fh_locked) {
+		WARN_ONCE(1, "nfsd_create: parent %pd2 not locked!\n",
+				dentry);
+		err = nfserr_io;
+		goto out;
+	}
+
+	err = nfsd_permission(rqstp, fhp->fh_export, dentry, NFSD_MAY_CREATE);
+	if (err)
+		goto out;
+
+	if (!(iap->ia_valid & ATTR_MODE))
+		iap->ia_mode = 0;
+	iap->ia_mode = (iap->ia_mode & S_IALLUGO) | type;
+
+	if (!IS_POSIXACL(dirp))
+		iap->ia_mode &= ~current_umask();
+
+	err = 0;
+	host_err = 0;
+	switch (type) {
+	case S_IFREG:
+		host_err = vfs_create(dirp, dchild, iap->ia_mode, true);
+		if (!host_err)
+			nfsd_check_ignore_resizing(iap);
+		break;
+	case S_IFDIR:
+		host_err = vfs_mkdir(dirp, dchild, iap->ia_mode);
+		if (!host_err && unlikely(d_unhashed(dchild))) {
+			struct dentry *d;
+			d = lookup_one_len(dchild->d_name.name,
+					   dchild->d_parent,
+					   dchild->d_name.len);
+			if (IS_ERR(d)) {
+				host_err = PTR_ERR(d);
+				break;
+			}
+			if (unlikely(d_is_negative(d))) {
+				dput(d);
+				err = nfserr_serverfault;
+				goto out;
+			}
+			dput(resfhp->fh_dentry);
+			resfhp->fh_dentry = dget(d);
+			err = fh_update(resfhp);
+			dput(dchild);
+			dchild = d;
+			if (err)
+				goto out;
+		}
+		break;
+	case S_IFCHR:
+	case S_IFBLK:
+	case S_IFIFO:
+	case S_IFSOCK:
+		host_err = vfs_mknod(dirp, dchild, iap->ia_mode, rdev);
+		break;
+	default:
+		printk(KERN_WARNING "nfsd: bad file type %o in nfsd_create\n",
+		       type);
+		host_err = -EINVAL;
+	}
+	if (host_err < 0)
+		goto out_nfserr;
+
+	err = nfsd_create_setattr(rqstp, resfhp, iap);
+
+	/*
+	 * nfsd_create_setattr already committed the child.  Transactional
+	 * filesystems had a chance to commit changes for both parent and
+	 * child simultaneously making the following commit_metadata a
+	 * noop.
+	 */
+	err2 = nfserrno(commit_metadata(fhp));
+	if (err2)
+		err = err2;
+	/*
+	 * Update the file handle to get the new inode info.
+	 */
+	if (!err)
+		err = fh_update(resfhp);
+out:
+	dput(dchild);
+	return err;
+
+out_nfserr:
+	err = nfserrno(host_err);
+	goto out;
+}
+
+/*
+ * Create a filesystem object (regular, directory, special).
+ * Note that the parent directory is left locked.
+ *
+ * N.B. Every call to nfsd_create needs an fh_put for _both_ fhp and resfhp
+ */
+__be32
+nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
+		char *fname, int flen, struct iattr *iap,
+		int type, dev_t rdev, struct svc_fh *resfhp)
+{
+	struct dentry	*dentry, *dchild = NULL;
+	__be32		err;
+	int		host_err;
+
+	if (isdotent(fname, flen))
+		return nfserr_exist;
+
+	err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_NOP);
+	if (err)
+		return err;
+
+	dentry = fhp->fh_dentry;
+
+	host_err = fh_want_write(fhp);
+	if (host_err)
+		return nfserrno(host_err);
+
+	fh_lock_nested(fhp, I_MUTEX_PARENT);
+	dchild = lookup_one_len(fname, dentry, flen);
+	host_err = PTR_ERR(dchild);
+	if (IS_ERR(dchild))
+		return nfserrno(host_err);
+	err = fh_compose(resfhp, fhp->fh_export, dchild, fhp);
+	/*
+	 * We unconditionally drop our ref to dchild as fh_compose will have
+	 * already grabbed its own ref for it.
+	 */
+	dput(dchild);
+	if (err)
+		return err;
+	return nfsd_create_locked(rqstp, fhp, fname, flen, iap, type,
+					rdev, resfhp);
+}
+
+#ifdef CONFIG_NFSD_V3
+
+/*
+ * NFSv3 and NFSv4 version of nfsd_create
+ */
+__be32
+do_nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
+		char *fname, int flen, struct iattr *iap,
+		struct svc_fh *resfhp, int createmode, u32 *verifier,
+	        bool *truncp, bool *created)
+{
+	struct dentry	*dentry, *dchild = NULL;
+	struct inode	*dirp;
+	__be32		err;
+	int		host_err;
+	__u32		v_mtime=0, v_atime=0;
+
+	err = nfserr_perm;
+	if (!flen)
+		goto out;
+	err = nfserr_exist;
+	if (isdotent(fname, flen))
+		goto out;
+	if (!(iap->ia_valid & ATTR_MODE))
+		iap->ia_mode = 0;
+	err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_EXEC);
+	if (err)
+		goto out;
+
+	dentry = fhp->fh_dentry;
+	dirp = d_inode(dentry);
+
+	host_err = fh_want_write(fhp);
+	if (host_err)
+		goto out_nfserr;
+
+	fh_lock_nested(fhp, I_MUTEX_PARENT);
+
+	/*
+	 * Compose the response file handle.
+	 */
+	dchild = lookup_one_len(fname, dentry, flen);
+	host_err = PTR_ERR(dchild);
+	if (IS_ERR(dchild))
+		goto out_nfserr;
+
+	/* If file doesn't exist, check for permissions to create one */
+	if (d_really_is_negative(dchild)) {
+		err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE);
+		if (err)
+			goto out;
+	}
+
+	err = fh_compose(resfhp, fhp->fh_export, dchild, fhp);
+	if (err)
+		goto out;
+
+	if (nfsd_create_is_exclusive(createmode)) {
+		/* solaris7 gets confused (bugid 4218508) if these have
+		 * the high bit set, so just clear the high bits. If this is
+		 * ever changed to use different attrs for storing the
+		 * verifier, then do_open_lookup() will also need to be fixed
+		 * accordingly.
+		 */
+		v_mtime = verifier[0]&0x7fffffff;
+		v_atime = verifier[1]&0x7fffffff;
+	}
+	
+	if (d_really_is_positive(dchild)) {
+		err = 0;
+
+		switch (createmode) {
+		case NFS3_CREATE_UNCHECKED:
+			if (! d_is_reg(dchild))
+				goto out;
+			else if (truncp) {
+				/* in nfsv4, we need to treat this case a little
+				 * differently.  we don't want to truncate the
+				 * file now; this would be wrong if the OPEN
+				 * fails for some other reason.  furthermore,
+				 * if the size is nonzero, we should ignore it
+				 * according to spec!
+				 */
+				*truncp = (iap->ia_valid & ATTR_SIZE) && !iap->ia_size;
+			}
+			else {
+				iap->ia_valid &= ATTR_SIZE;
+				goto set_attr;
+			}
+			break;
+		case NFS3_CREATE_EXCLUSIVE:
+			if (   d_inode(dchild)->i_mtime.tv_sec == v_mtime
+			    && d_inode(dchild)->i_atime.tv_sec == v_atime
+			    && d_inode(dchild)->i_size  == 0 ) {
+				if (created)
+					*created = true;
+				break;
+			}
+			fallthrough;
+		case NFS4_CREATE_EXCLUSIVE4_1:
+			if (   d_inode(dchild)->i_mtime.tv_sec == v_mtime
+			    && d_inode(dchild)->i_atime.tv_sec == v_atime
+			    && d_inode(dchild)->i_size  == 0 ) {
+				if (created)
+					*created = true;
+				goto set_attr;
+			}
+			fallthrough;
+		case NFS3_CREATE_GUARDED:
+			err = nfserr_exist;
+		}
+		fh_drop_write(fhp);
+		goto out;
+	}
+
+	if (!IS_POSIXACL(dirp))
+		iap->ia_mode &= ~current_umask();
+
+	host_err = vfs_create(dirp, dchild, iap->ia_mode, true);
+	if (host_err < 0) {
+		fh_drop_write(fhp);
+		goto out_nfserr;
+	}
+	if (created)
+		*created = true;
+
+	nfsd_check_ignore_resizing(iap);
+
+	if (nfsd_create_is_exclusive(createmode)) {
+		/* Cram the verifier into atime/mtime */
+		iap->ia_valid = ATTR_MTIME|ATTR_ATIME
+			| ATTR_MTIME_SET|ATTR_ATIME_SET;
+		/* XXX someone who knows this better please fix it for nsec */ 
+		iap->ia_mtime.tv_sec = v_mtime;
+		iap->ia_atime.tv_sec = v_atime;
+		iap->ia_mtime.tv_nsec = 0;
+		iap->ia_atime.tv_nsec = 0;
+	}
+
+ set_attr:
+	err = nfsd_create_setattr(rqstp, resfhp, iap);
+
+	/*
+	 * nfsd_create_setattr already committed the child
+	 * (and possibly also the parent).
+	 */
+	if (!err)
+		err = nfserrno(commit_metadata(fhp));
+
+	/*
+	 * Update the filehandle to get the new inode info.
+	 */
+	if (!err)
+		err = fh_update(resfhp);
+
+ out:
+	fh_unlock(fhp);
+	if (dchild && !IS_ERR(dchild))
+		dput(dchild);
+	fh_drop_write(fhp);
+ 	return err;
+ 
+ out_nfserr:
+	err = nfserrno(host_err);
+	goto out;
+}
+#endif /* CONFIG_NFSD_V3 */
+
+/*
+ * Read a symlink. On entry, *lenp must contain the maximum path length that
+ * fits into the buffer. On return, it contains the true length.
+ * N.B. After this call fhp needs an fh_put
+ */
+__be32
+nfsd_readlink(struct svc_rqst *rqstp, struct svc_fh *fhp, char *buf, int *lenp)
+{
+	__be32		err;
+	const char *link;
+	struct path path;
+	DEFINE_DELAYED_CALL(done);
+	int len;
+
+	err = fh_verify(rqstp, fhp, S_IFLNK, NFSD_MAY_NOP);
+	if (unlikely(err))
+		return err;
+
+	path.mnt = fhp->fh_export->ex_path.mnt;
+	path.dentry = fhp->fh_dentry;
+
+	if (unlikely(!d_is_symlink(path.dentry)))
+		return nfserr_inval;
+
+	touch_atime(&path);
+
+	link = vfs_get_link(path.dentry, &done);
+	if (IS_ERR(link))
+		return nfserrno(PTR_ERR(link));
+
+	len = strlen(link);
+	if (len < *lenp)
+		*lenp = len;
+	memcpy(buf, link, *lenp);
+	do_delayed_call(&done);
+	return 0;
+}
+
+/*
+ * Create a symlink and look up its inode
+ * N.B. After this call _both_ fhp and resfhp need an fh_put
+ */
+__be32
+nfsd_symlink(struct svc_rqst *rqstp, struct svc_fh *fhp,
+				char *fname, int flen,
+				char *path,
+				struct svc_fh *resfhp)
+{
+	struct dentry	*dentry, *dnew;
+	__be32		err, cerr;
+	int		host_err;
+
+	err = nfserr_noent;
+	if (!flen || path[0] == '\0')
+		goto out;
+	err = nfserr_exist;
+	if (isdotent(fname, flen))
+		goto out;
+
+	err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE);
+	if (err)
+		goto out;
+
+	host_err = fh_want_write(fhp);
+	if (host_err)
+		goto out_nfserr;
+
+	fh_lock(fhp);
+	dentry = fhp->fh_dentry;
+	dnew = lookup_one_len(fname, dentry, flen);
+	host_err = PTR_ERR(dnew);
+	if (IS_ERR(dnew))
+		goto out_nfserr;
+
+	host_err = vfs_symlink(d_inode(dentry), dnew, path);
+	err = nfserrno(host_err);
+	if (!err)
+		err = nfserrno(commit_metadata(fhp));
+	fh_unlock(fhp);
+
+	fh_drop_write(fhp);
+
+	cerr = fh_compose(resfhp, fhp->fh_export, dnew, fhp);
+	dput(dnew);
+	if (err==0) err = cerr;
+out:
+	return err;
+
+out_nfserr:
+	err = nfserrno(host_err);
+	goto out;
+}
+
+/*
+ * Create a hardlink
+ * N.B. After this call _both_ ffhp and tfhp need an fh_put
+ */
+__be32
+nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp,
+				char *name, int len, struct svc_fh *tfhp)
+{
+	struct dentry	*ddir, *dnew, *dold;
+	struct inode	*dirp;
+	__be32		err;
+	int		host_err;
+
+	err = fh_verify(rqstp, ffhp, S_IFDIR, NFSD_MAY_CREATE);
+	if (err)
+		goto out;
+	err = fh_verify(rqstp, tfhp, 0, NFSD_MAY_NOP);
+	if (err)
+		goto out;
+	err = nfserr_isdir;
+	if (d_is_dir(tfhp->fh_dentry))
+		goto out;
+	err = nfserr_perm;
+	if (!len)
+		goto out;
+	err = nfserr_exist;
+	if (isdotent(name, len))
+		goto out;
+
+	host_err = fh_want_write(tfhp);
+	if (host_err) {
+		err = nfserrno(host_err);
+		goto out;
+	}
+
+	fh_lock_nested(ffhp, I_MUTEX_PARENT);
+	ddir = ffhp->fh_dentry;
+	dirp = d_inode(ddir);
+
+	dnew = lookup_one_len(name, ddir, len);
+	host_err = PTR_ERR(dnew);
+	if (IS_ERR(dnew))
+		goto out_nfserr;
+
+	dold = tfhp->fh_dentry;
+
+	err = nfserr_noent;
+	if (d_really_is_negative(dold))
+		goto out_dput;
+	host_err = vfs_link(dold, dirp, dnew, NULL);
+	if (!host_err) {
+		err = nfserrno(commit_metadata(ffhp));
+		if (!err)
+			err = nfserrno(commit_metadata(tfhp));
+	} else {
+		if (host_err == -EXDEV && rqstp->rq_vers == 2)
+			err = nfserr_acces;
+		else
+			err = nfserrno(host_err);
+	}
+out_dput:
+	dput(dnew);
+out_unlock:
+	fh_unlock(ffhp);
+	fh_drop_write(tfhp);
+out:
+	return err;
+
+out_nfserr:
+	err = nfserrno(host_err);
+	goto out_unlock;
+}
+
+static void
+nfsd_close_cached_files(struct dentry *dentry)
+{
+	struct inode *inode = d_inode(dentry);
+
+	if (inode && S_ISREG(inode->i_mode))
+		nfsd_file_close_inode_sync(inode);
+}
+
+static bool
+nfsd_has_cached_files(struct dentry *dentry)
+{
+	bool		ret = false;
+	struct inode *inode = d_inode(dentry);
+
+	if (inode && S_ISREG(inode->i_mode))
+		ret = nfsd_file_is_cached(inode);
+	return ret;
+}
+
+/*
+ * Rename a file
+ * N.B. After this call _both_ ffhp and tfhp need an fh_put
+ */
+__be32
+nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen,
+			    struct svc_fh *tfhp, char *tname, int tlen)
+{
+	struct dentry	*fdentry, *tdentry, *odentry, *ndentry, *trap;
+	struct inode	*fdir, *tdir;
+	__be32		err;
+	int		host_err;
+	bool		has_cached = false;
+
+	err = fh_verify(rqstp, ffhp, S_IFDIR, NFSD_MAY_REMOVE);
+	if (err)
+		goto out;
+	err = fh_verify(rqstp, tfhp, S_IFDIR, NFSD_MAY_CREATE);
+	if (err)
+		goto out;
+
+	fdentry = ffhp->fh_dentry;
+	fdir = d_inode(fdentry);
+
+	tdentry = tfhp->fh_dentry;
+	tdir = d_inode(tdentry);
+
+	err = nfserr_perm;
+	if (!flen || isdotent(fname, flen) || !tlen || isdotent(tname, tlen))
+		goto out;
+
+	err = (rqstp->rq_vers == 2) ? nfserr_acces : nfserr_xdev;
+	if (ffhp->fh_export->ex_path.mnt != tfhp->fh_export->ex_path.mnt)
+		goto out;
+	if (ffhp->fh_export->ex_path.dentry != tfhp->fh_export->ex_path.dentry)
+		goto out;
+
+retry:
+	host_err = fh_want_write(ffhp);
+	if (host_err) {
+		err = nfserrno(host_err);
+		goto out;
+	}
+
+	/* cannot use fh_lock as we need deadlock protective ordering
+	 * so do it by hand */
+	trap = lock_rename(tdentry, fdentry);
+	ffhp->fh_locked = tfhp->fh_locked = true;
+	fill_pre_wcc(ffhp);
+	fill_pre_wcc(tfhp);
+
+	odentry = lookup_one_len(fname, fdentry, flen);
+	host_err = PTR_ERR(odentry);
+	if (IS_ERR(odentry))
+		goto out_nfserr;
+
+	host_err = -ENOENT;
+	if (d_really_is_negative(odentry))
+		goto out_dput_old;
+	host_err = -EINVAL;
+	if (odentry == trap)
+		goto out_dput_old;
+
+	ndentry = lookup_one_len(tname, tdentry, tlen);
+	host_err = PTR_ERR(ndentry);
+	if (IS_ERR(ndentry))
+		goto out_dput_old;
+	host_err = -ENOTEMPTY;
+	if (ndentry == trap)
+		goto out_dput_new;
+
+	if (nfsd_has_cached_files(ndentry)) {
+		has_cached = true;
+		goto out_dput_old;
+	} else {
+		host_err = vfs_rename(fdir, odentry, tdir, ndentry, NULL, 0);
+		if (!host_err) {
+			host_err = commit_metadata(tfhp);
+			if (!host_err)
+				host_err = commit_metadata(ffhp);
+		}
+	}
+ out_dput_new:
+	dput(ndentry);
+ out_dput_old:
+	dput(odentry);
+ out_nfserr:
+	err = nfserrno(host_err);
+	/*
+	 * We cannot rely on fh_unlock on the two filehandles,
+	 * as that would do the wrong thing if the two directories
+	 * were the same, so again we do it by hand.
+	 */
+	if (!has_cached) {
+		fill_post_wcc(ffhp);
+		fill_post_wcc(tfhp);
+	}
+	unlock_rename(tdentry, fdentry);
+	ffhp->fh_locked = tfhp->fh_locked = false;
+	fh_drop_write(ffhp);
+
+	/*
+	 * If the target dentry has cached open files, then we need to try to
+	 * close them prior to doing the rename. Flushing delayed fput
+	 * shouldn't be done with locks held however, so we delay it until this
+	 * point and then reattempt the whole shebang.
+	 */
+	if (has_cached) {
+		has_cached = false;
+		nfsd_close_cached_files(ndentry);
+		dput(ndentry);
+		goto retry;
+	}
+out:
+	return err;
+}
+
+/*
+ * Unlink a file or directory
+ * N.B. After this call fhp needs an fh_put
+ */
+__be32
+nfsd_unlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int type,
+				char *fname, int flen)
+{
+	struct dentry	*dentry, *rdentry;
+	struct inode	*dirp;
+	__be32		err;
+	int		host_err;
+
+	err = nfserr_acces;
+	if (!flen || isdotent(fname, flen))
+		goto out;
+	err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_REMOVE);
+	if (err)
+		goto out;
+
+	host_err = fh_want_write(fhp);
+	if (host_err)
+		goto out_nfserr;
+
+	fh_lock_nested(fhp, I_MUTEX_PARENT);
+	dentry = fhp->fh_dentry;
+	dirp = d_inode(dentry);
+
+	rdentry = lookup_one_len(fname, dentry, flen);
+	host_err = PTR_ERR(rdentry);
+	if (IS_ERR(rdentry))
+		goto out_drop_write;
+
+	if (d_really_is_negative(rdentry)) {
+		dput(rdentry);
+		host_err = -ENOENT;
+		goto out_drop_write;
+	}
+
+	if (!type)
+		type = d_inode(rdentry)->i_mode & S_IFMT;
+
+	if (type != S_IFDIR) {
+		nfsd_close_cached_files(rdentry);
+		host_err = vfs_unlink(dirp, rdentry, NULL);
+	} else {
+		host_err = vfs_rmdir(dirp, rdentry);
+	}
+
+	if (!host_err)
+		host_err = commit_metadata(fhp);
+	dput(rdentry);
+
+out_drop_write:
+	fh_drop_write(fhp);
+out_nfserr:
+	if (host_err == -EBUSY) {
+		/* name is mounted-on. There is no perfect
+		 * error status.
+		 */
+		if (nfsd_v4client(rqstp))
+			err = nfserr_file_open;
+		else
+			err = nfserr_acces;
+	} else {
+		err = nfserrno(host_err);
+	}
+out:
+	return err;
+}
+
+/*
+ * We do this buffering because we must not call back into the file
+ * system's ->lookup() method from the filldir callback. That may well
+ * deadlock a number of file systems.
+ *
+ * This is based heavily on the implementation of same in XFS.
+ */
+struct buffered_dirent {
+	u64		ino;
+	loff_t		offset;
+	int		namlen;
+	unsigned int	d_type;
+	char		name[];
+};
+
+struct readdir_data {
+	struct dir_context ctx;
+	char		*dirent;
+	size_t		used;
+	int		full;
+};
+
+static int nfsd_buffered_filldir(struct dir_context *ctx, const char *name,
+				 int namlen, loff_t offset, u64 ino,
+				 unsigned int d_type)
+{
+	struct readdir_data *buf =
+		container_of(ctx, struct readdir_data, ctx);
+	struct buffered_dirent *de = (void *)(buf->dirent + buf->used);
+	unsigned int reclen;
+
+	reclen = ALIGN(sizeof(struct buffered_dirent) + namlen, sizeof(u64));
+	if (buf->used + reclen > PAGE_SIZE) {
+		buf->full = 1;
+		return -EINVAL;
+	}
+
+	de->namlen = namlen;
+	de->offset = offset;
+	de->ino = ino;
+	de->d_type = d_type;
+	memcpy(de->name, name, namlen);
+	buf->used += reclen;
+
+	return 0;
+}
+
+static __be32 nfsd_buffered_readdir(struct file *file, nfsd_filldir_t func,
+				    struct readdir_cd *cdp, loff_t *offsetp)
+{
+	struct buffered_dirent *de;
+	int host_err;
+	int size;
+	loff_t offset;
+	struct readdir_data buf = {
+		.ctx.actor = nfsd_buffered_filldir,
+		.dirent = (void *)__get_free_page(GFP_KERNEL)
+	};
+
+	if (!buf.dirent)
+		return nfserrno(-ENOMEM);
+
+	offset = *offsetp;
+
+	while (1) {
+		unsigned int reclen;
+
+		cdp->err = nfserr_eof; /* will be cleared on successful read */
+		buf.used = 0;
+		buf.full = 0;
+
+		host_err = iterate_dir(file, &buf.ctx);
+		if (buf.full)
+			host_err = 0;
+
+		if (host_err < 0)
+			break;
+
+		size = buf.used;
+
+		if (!size)
+			break;
+
+		de = (struct buffered_dirent *)buf.dirent;
+		while (size > 0) {
+			offset = de->offset;
+
+			if (func(cdp, de->name, de->namlen, de->offset,
+				 de->ino, de->d_type))
+				break;
+
+			if (cdp->err != nfs_ok)
+				break;
+
+			reclen = ALIGN(sizeof(*de) + de->namlen,
+				       sizeof(u64));
+			size -= reclen;
+			de = (struct buffered_dirent *)((char *)de + reclen);
+		}
+		if (size > 0) /* We bailed out early */
+			break;
+
+		offset = vfs_llseek(file, 0, SEEK_CUR);
+	}
+
+	free_page((unsigned long)(buf.dirent));
+
+	if (host_err)
+		return nfserrno(host_err);
+
+	*offsetp = offset;
+	return cdp->err;
+}
+
+/*
+ * Read entries from a directory.
+ * The  NFSv3/4 verifier we ignore for now.
+ */
+__be32
+nfsd_readdir(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t *offsetp, 
+	     struct readdir_cd *cdp, nfsd_filldir_t func)
+{
+	__be32		err;
+	struct file	*file;
+	loff_t		offset = *offsetp;
+	int             may_flags = NFSD_MAY_READ;
+
+	/* NFSv2 only supports 32 bit cookies */
+	if (rqstp->rq_vers > 2)
+		may_flags |= NFSD_MAY_64BIT_COOKIE;
+
+	err = nfsd_open(rqstp, fhp, S_IFDIR, may_flags, &file);
+	if (err)
+		goto out;
+
+	offset = vfs_llseek(file, offset, SEEK_SET);
+	if (offset < 0) {
+		err = nfserrno((int)offset);
+		goto out_close;
+	}
+
+	err = nfsd_buffered_readdir(file, func, cdp, offsetp);
+
+	if (err == nfserr_eof || err == nfserr_toosmall)
+		err = nfs_ok; /* can still be found in ->err */
+out_close:
+	fput(file);
+out:
+	return err;
+}
+
+/*
+ * Get file system stats
+ * N.B. After this call fhp needs an fh_put
+ */
+__be32
+nfsd_statfs(struct svc_rqst *rqstp, struct svc_fh *fhp, struct kstatfs *stat, int access)
+{
+	__be32 err;
+
+	err = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP | access);
+	if (!err) {
+		struct path path = {
+			.mnt	= fhp->fh_export->ex_path.mnt,
+			.dentry	= fhp->fh_dentry,
+		};
+		if (vfs_statfs(&path, stat))
+			err = nfserr_io;
+	}
+	return err;
+}
+
+static int exp_rdonly(struct svc_rqst *rqstp, struct svc_export *exp)
+{
+	return nfsexp_flags(rqstp, exp) & NFSEXP_READONLY;
+}
+
+#ifdef CONFIG_NFSD_V4
+/*
+ * Helper function to translate error numbers. In the case of xattr operations,
+ * some error codes need to be translated outside of the standard translations.
+ *
+ * ENODATA needs to be translated to nfserr_noxattr.
+ * E2BIG to nfserr_xattr2big.
+ *
+ * Additionally, vfs_listxattr can return -ERANGE. This means that the
+ * file has too many extended attributes to retrieve inside an
+ * XATTR_LIST_MAX sized buffer. This is a bug in the xattr implementation:
+ * filesystems will allow the adding of extended attributes until they hit
+ * their own internal limit. This limit may be larger than XATTR_LIST_MAX.
+ * So, at that point, the attributes are present and valid, but can't
+ * be retrieved using listxattr, since the upper level xattr code enforces
+ * the XATTR_LIST_MAX limit.
+ *
+ * This bug means that we need to deal with listxattr returning -ERANGE. The
+ * best mapping is to return TOOSMALL.
+ */
+static __be32
+nfsd_xattr_errno(int err)
+{
+	switch (err) {
+	case -ENODATA:
+		return nfserr_noxattr;
+	case -E2BIG:
+		return nfserr_xattr2big;
+	case -ERANGE:
+		return nfserr_toosmall;
+	}
+	return nfserrno(err);
+}
+
+/*
+ * Retrieve the specified user extended attribute. To avoid always
+ * having to allocate the maximum size (since we are not getting
+ * a maximum size from the RPC), do a probe + alloc. Hold a reader
+ * lock on i_rwsem to prevent the extended attribute from changing
+ * size while we're doing this.
+ */
+__be32
+nfsd_getxattr(struct svc_rqst *rqstp, struct svc_fh *fhp, char *name,
+	      void **bufp, int *lenp)
+{
+	ssize_t len;
+	__be32 err;
+	char *buf;
+	struct inode *inode;
+	struct dentry *dentry;
+
+	err = fh_verify(rqstp, fhp, 0, NFSD_MAY_READ);
+	if (err)
+		return err;
+
+	err = nfs_ok;
+	dentry = fhp->fh_dentry;
+	inode = d_inode(dentry);
+
+	inode_lock_shared(inode);
+
+	len = vfs_getxattr(dentry, name, NULL, 0);
+
+	/*
+	 * Zero-length attribute, just return.
+	 */
+	if (len == 0) {
+		*bufp = NULL;
+		*lenp = 0;
+		goto out;
+	}
+
+	if (len < 0) {
+		err = nfsd_xattr_errno(len);
+		goto out;
+	}
+
+	if (len > *lenp) {
+		err = nfserr_toosmall;
+		goto out;
+	}
+
+	buf = kvmalloc(len, GFP_KERNEL | GFP_NOFS);
+	if (buf == NULL) {
+		err = nfserr_jukebox;
+		goto out;
+	}
+
+	len = vfs_getxattr(dentry, name, buf, len);
+	if (len <= 0) {
+		kvfree(buf);
+		buf = NULL;
+		err = nfsd_xattr_errno(len);
+	}
+
+	*lenp = len;
+	*bufp = buf;
+
+out:
+	inode_unlock_shared(inode);
+
+	return err;
+}
+
+/*
+ * Retrieve the xattr names. Since we can't know how many are
+ * user extended attributes, we must get all attributes here,
+ * and have the XDR encode filter out the "user." ones.
+ *
+ * While this could always just allocate an XATTR_LIST_MAX
+ * buffer, that's a waste, so do a probe + allocate. To
+ * avoid any changes between the probe and allocate, wrap
+ * this in inode_lock.
+ */
+__be32
+nfsd_listxattr(struct svc_rqst *rqstp, struct svc_fh *fhp, char **bufp,
+	       int *lenp)
+{
+	ssize_t len;
+	__be32 err;
+	char *buf;
+	struct inode *inode;
+	struct dentry *dentry;
+
+	err = fh_verify(rqstp, fhp, 0, NFSD_MAY_READ);
+	if (err)
+		return err;
+
+	dentry = fhp->fh_dentry;
+	inode = d_inode(dentry);
+	*lenp = 0;
+
+	inode_lock_shared(inode);
+
+	len = vfs_listxattr(dentry, NULL, 0);
+	if (len <= 0) {
+		err = nfsd_xattr_errno(len);
+		goto out;
+	}
+
+	if (len > XATTR_LIST_MAX) {
+		err = nfserr_xattr2big;
+		goto out;
+	}
+
+	/*
+	 * We're holding i_rwsem - use GFP_NOFS.
+	 */
+	buf = kvmalloc(len, GFP_KERNEL | GFP_NOFS);
+	if (buf == NULL) {
+		err = nfserr_jukebox;
+		goto out;
+	}
+
+	len = vfs_listxattr(dentry, buf, len);
+	if (len <= 0) {
+		kvfree(buf);
+		err = nfsd_xattr_errno(len);
+		goto out;
+	}
+
+	*lenp = len;
+	*bufp = buf;
+
+	err = nfs_ok;
+out:
+	inode_unlock_shared(inode);
+
+	return err;
+}
+
+/*
+ * Removexattr and setxattr need to call fh_lock to both lock the inode
+ * and set the change attribute. Since the top-level vfs_removexattr
+ * and vfs_setxattr calls already do their own inode_lock calls, call
+ * the _locked variant. Pass in a NULL pointer for delegated_inode,
+ * and let the client deal with NFS4ERR_DELAY (same as with e.g.
+ * setattr and remove).
+ */
+__be32
+nfsd_removexattr(struct svc_rqst *rqstp, struct svc_fh *fhp, char *name)
+{
+	__be32 err;
+	int ret;
+
+	err = fh_verify(rqstp, fhp, 0, NFSD_MAY_WRITE);
+	if (err)
+		return err;
+
+	ret = fh_want_write(fhp);
+	if (ret)
+		return nfserrno(ret);
+
+	fh_lock(fhp);
+
+	ret = __vfs_removexattr_locked(fhp->fh_dentry, name, NULL);
+
+	fh_unlock(fhp);
+	fh_drop_write(fhp);
+
+	return nfsd_xattr_errno(ret);
+}
+
+__be32
+nfsd_setxattr(struct svc_rqst *rqstp, struct svc_fh *fhp, char *name,
+	      void *buf, u32 len, u32 flags)
+{
+	__be32 err;
+	int ret;
+
+	err = fh_verify(rqstp, fhp, 0, NFSD_MAY_WRITE);
+	if (err)
+		return err;
+
+	ret = fh_want_write(fhp);
+	if (ret)
+		return nfserrno(ret);
+	fh_lock(fhp);
+
+	ret = __vfs_setxattr_locked(fhp->fh_dentry, name, buf, len, flags,
+				    NULL);
+
+	fh_unlock(fhp);
+	fh_drop_write(fhp);
+
+	return nfsd_xattr_errno(ret);
+}
+#endif
+
+/*
+ * Check for a user's access permissions to this inode.
+ */
+__be32
+nfsd_permission(struct svc_rqst *rqstp, struct svc_export *exp,
+					struct dentry *dentry, int acc)
+{
+	struct inode	*inode = d_inode(dentry);
+	int		err;
+
+	if ((acc & NFSD_MAY_MASK) == NFSD_MAY_NOP)
+		return 0;
+#if 0
+	dprintk("nfsd: permission 0x%x%s%s%s%s%s%s%s mode 0%o%s%s%s\n",
+		acc,
+		(acc & NFSD_MAY_READ)?	" read"  : "",
+		(acc & NFSD_MAY_WRITE)?	" write" : "",
+		(acc & NFSD_MAY_EXEC)?	" exec"  : "",
+		(acc & NFSD_MAY_SATTR)?	" sattr" : "",
+		(acc & NFSD_MAY_TRUNC)?	" trunc" : "",
+		(acc & NFSD_MAY_LOCK)?	" lock"  : "",
+		(acc & NFSD_MAY_OWNER_OVERRIDE)? " owneroverride" : "",
+		inode->i_mode,
+		IS_IMMUTABLE(inode)?	" immut" : "",
+		IS_APPEND(inode)?	" append" : "",
+		__mnt_is_readonly(exp->ex_path.mnt)?	" ro" : "");
+	dprintk("      owner %d/%d user %d/%d\n",
+		inode->i_uid, inode->i_gid, current_fsuid(), current_fsgid());
+#endif
+
+	/* Normally we reject any write/sattr etc access on a read-only file
+	 * system.  But if it is IRIX doing check on write-access for a 
+	 * device special file, we ignore rofs.
+	 */
+	if (!(acc & NFSD_MAY_LOCAL_ACCESS))
+		if (acc & (NFSD_MAY_WRITE | NFSD_MAY_SATTR | NFSD_MAY_TRUNC)) {
+			if (exp_rdonly(rqstp, exp) ||
+			    __mnt_is_readonly(exp->ex_path.mnt))
+				return nfserr_rofs;
+			if (/* (acc & NFSD_MAY_WRITE) && */ IS_IMMUTABLE(inode))
+				return nfserr_perm;
+		}
+	if ((acc & NFSD_MAY_TRUNC) && IS_APPEND(inode))
+		return nfserr_perm;
+
+	if (acc & NFSD_MAY_LOCK) {
+		/* If we cannot rely on authentication in NLM requests,
+		 * just allow locks, otherwise require read permission, or
+		 * ownership
+		 */
+		if (exp->ex_flags & NFSEXP_NOAUTHNLM)
+			return 0;
+		else
+			acc = NFSD_MAY_READ | NFSD_MAY_OWNER_OVERRIDE;
+	}
+	/*
+	 * The file owner always gets access permission for accesses that
+	 * would normally be checked at open time. This is to make
+	 * file access work even when the client has done a fchmod(fd, 0).
+	 *
+	 * However, `cp foo bar' should fail nevertheless when bar is
+	 * readonly. A sensible way to do this might be to reject all
+	 * attempts to truncate a read-only file, because a creat() call
+	 * always implies file truncation.
+	 * ... but this isn't really fair.  A process may reasonably call
+	 * ftruncate on an open file descriptor on a file with perm 000.
+	 * We must trust the client to do permission checking - using "ACCESS"
+	 * with NFSv3.
+	 */
+	if ((acc & NFSD_MAY_OWNER_OVERRIDE) &&
+	    uid_eq(inode->i_uid, current_fsuid()))
+		return 0;
+
+	/* This assumes  NFSD_MAY_{READ,WRITE,EXEC} == MAY_{READ,WRITE,EXEC} */
+	err = inode_permission(inode, acc & (MAY_READ|MAY_WRITE|MAY_EXEC));
+
+	/* Allow read access to binaries even when mode 111 */
+	if (err == -EACCES && S_ISREG(inode->i_mode) &&
+	     (acc == (NFSD_MAY_READ | NFSD_MAY_OWNER_OVERRIDE) ||
+	      acc == (NFSD_MAY_READ | NFSD_MAY_READ_IF_EXEC)))
+		err = inode_permission(inode, MAY_EXEC);
+
+	return err? nfserrno(err) : 0;
+}
diff --git a/fs/nfsd/vfs.h b/fs/nfsd/vfs.h
new file mode 100644
index 000000000..a2442ebe5
--- /dev/null
+++ b/fs/nfsd/vfs.h
@@ -0,0 +1,169 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 1995-1997 Olaf Kirch <okir@monad.swb.de>
+ */
+
+#ifndef LINUX_NFSD_VFS_H
+#define LINUX_NFSD_VFS_H
+
+#include "nfsfh.h"
+#include "nfsd.h"
+
+/*
+ * Flags for nfsd_permission
+ */
+#define NFSD_MAY_NOP			0
+#define NFSD_MAY_EXEC			0x001 /* == MAY_EXEC */
+#define NFSD_MAY_WRITE			0x002 /* == MAY_WRITE */
+#define NFSD_MAY_READ			0x004 /* == MAY_READ */
+#define NFSD_MAY_SATTR			0x008
+#define NFSD_MAY_TRUNC			0x010
+#define NFSD_MAY_LOCK			0x020
+#define NFSD_MAY_MASK			0x03f
+
+/* extra hints to permission and open routines: */
+#define NFSD_MAY_OWNER_OVERRIDE		0x040
+#define NFSD_MAY_LOCAL_ACCESS		0x080 /* for device special files */
+#define NFSD_MAY_BYPASS_GSS_ON_ROOT	0x100
+#define NFSD_MAY_NOT_BREAK_LEASE	0x200
+#define NFSD_MAY_BYPASS_GSS		0x400
+#define NFSD_MAY_READ_IF_EXEC		0x800
+
+#define NFSD_MAY_64BIT_COOKIE		0x1000 /* 64 bit readdir cookies for >= NFSv3 */
+
+#define NFSD_MAY_CREATE		(NFSD_MAY_EXEC|NFSD_MAY_WRITE)
+#define NFSD_MAY_REMOVE		(NFSD_MAY_EXEC|NFSD_MAY_WRITE|NFSD_MAY_TRUNC)
+
+struct nfsd_file;
+
+/*
+ * Callback function for readdir
+ */
+typedef int (*nfsd_filldir_t)(void *, const char *, int, loff_t, u64, unsigned);
+
+/* nfsd/vfs.c */
+int		nfsd_cross_mnt(struct svc_rqst *rqstp, struct dentry **dpp,
+		                struct svc_export **expp);
+__be32		nfsd_lookup(struct svc_rqst *, struct svc_fh *,
+				const char *, unsigned int, struct svc_fh *);
+__be32		 nfsd_lookup_dentry(struct svc_rqst *, struct svc_fh *,
+				const char *, unsigned int,
+				struct svc_export **, struct dentry **);
+__be32		nfsd_setattr(struct svc_rqst *, struct svc_fh *,
+				struct iattr *, int, time64_t);
+int nfsd_mountpoint(struct dentry *, struct svc_export *);
+#ifdef CONFIG_NFSD_V4
+__be32          nfsd4_set_nfs4_label(struct svc_rqst *, struct svc_fh *,
+		    struct xdr_netobj *);
+__be32		nfsd4_vfs_fallocate(struct svc_rqst *, struct svc_fh *,
+				    struct file *, loff_t, loff_t, int);
+__be32		nfsd4_clone_file_range(struct nfsd_file *nf_src, u64 src_pos,
+				       struct nfsd_file *nf_dst, u64 dst_pos,
+				       u64 count, bool sync);
+#endif /* CONFIG_NFSD_V4 */
+__be32		nfsd_create_locked(struct svc_rqst *, struct svc_fh *,
+				char *name, int len, struct iattr *attrs,
+				int type, dev_t rdev, struct svc_fh *res);
+__be32		nfsd_create(struct svc_rqst *, struct svc_fh *,
+				char *name, int len, struct iattr *attrs,
+				int type, dev_t rdev, struct svc_fh *res);
+#ifdef CONFIG_NFSD_V3
+__be32		nfsd_access(struct svc_rqst *, struct svc_fh *, u32 *, u32 *);
+__be32		do_nfsd_create(struct svc_rqst *, struct svc_fh *,
+				char *name, int len, struct iattr *attrs,
+				struct svc_fh *res, int createmode,
+				u32 *verifier, bool *truncp, bool *created);
+__be32		nfsd_commit(struct svc_rqst *, struct svc_fh *,
+				loff_t, unsigned long, __be32 *verf);
+#endif /* CONFIG_NFSD_V3 */
+#ifdef CONFIG_NFSD_V4
+__be32		nfsd_getxattr(struct svc_rqst *rqstp, struct svc_fh *fhp,
+			    char *name, void **bufp, int *lenp);
+__be32		nfsd_listxattr(struct svc_rqst *rqstp, struct svc_fh *fhp,
+			    char **bufp, int *lenp);
+__be32		nfsd_removexattr(struct svc_rqst *rqstp, struct svc_fh *fhp,
+			    char *name);
+__be32		nfsd_setxattr(struct svc_rqst *rqstp, struct svc_fh *fhp,
+			    char *name, void *buf, u32 len, u32 flags);
+#endif
+int 		nfsd_open_break_lease(struct inode *, int);
+__be32		nfsd_open(struct svc_rqst *, struct svc_fh *, umode_t,
+				int, struct file **);
+__be32		nfsd_open_verified(struct svc_rqst *, struct svc_fh *, umode_t,
+				int, struct file **);
+__be32		nfsd_splice_read(struct svc_rqst *rqstp, struct svc_fh *fhp,
+				struct file *file, loff_t offset,
+				unsigned long *count,
+				u32 *eof);
+__be32		nfsd_readv(struct svc_rqst *rqstp, struct svc_fh *fhp,
+				struct file *file, loff_t offset,
+				struct kvec *vec, int vlen,
+				unsigned long *count,
+				u32 *eof);
+__be32 		nfsd_read(struct svc_rqst *, struct svc_fh *,
+				loff_t, struct kvec *, int, unsigned long *,
+				u32 *eof);
+__be32 		nfsd_write(struct svc_rqst *, struct svc_fh *, loff_t,
+				struct kvec *, int, unsigned long *,
+				int stable, __be32 *verf);
+__be32		nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp,
+				struct nfsd_file *nf, loff_t offset,
+				struct kvec *vec, int vlen, unsigned long *cnt,
+				int stable, __be32 *verf);
+__be32		nfsd_readlink(struct svc_rqst *, struct svc_fh *,
+				char *, int *);
+__be32		nfsd_symlink(struct svc_rqst *, struct svc_fh *,
+				char *name, int len, char *path,
+				struct svc_fh *res);
+__be32		nfsd_link(struct svc_rqst *, struct svc_fh *,
+				char *, int, struct svc_fh *);
+ssize_t		nfsd_copy_file_range(struct file *, u64,
+				     struct file *, u64, u64);
+__be32		nfsd_rename(struct svc_rqst *,
+				struct svc_fh *, char *, int,
+				struct svc_fh *, char *, int);
+__be32		nfsd_unlink(struct svc_rqst *, struct svc_fh *, int type,
+				char *name, int len);
+__be32		nfsd_readdir(struct svc_rqst *, struct svc_fh *,
+			     loff_t *, struct readdir_cd *, nfsd_filldir_t);
+__be32		nfsd_statfs(struct svc_rqst *, struct svc_fh *,
+				struct kstatfs *, int access);
+
+__be32		nfsd_permission(struct svc_rqst *, struct svc_export *,
+				struct dentry *, int);
+
+static inline int fh_want_write(struct svc_fh *fh)
+{
+	int ret;
+
+	if (fh->fh_want_write)
+		return 0;
+	ret = mnt_want_write(fh->fh_export->ex_path.mnt);
+	if (!ret)
+		fh->fh_want_write = true;
+	return ret;
+}
+
+static inline void fh_drop_write(struct svc_fh *fh)
+{
+	if (fh->fh_want_write) {
+		fh->fh_want_write = false;
+		mnt_drop_write(fh->fh_export->ex_path.mnt);
+	}
+}
+
+static inline __be32 fh_getattr(struct svc_fh *fh, struct kstat *stat)
+{
+	struct path p = {.mnt = fh->fh_export->ex_path.mnt,
+			 .dentry = fh->fh_dentry};
+	return nfserrno(vfs_getattr(&p, stat, STATX_BASIC_STATS,
+				    AT_STATX_SYNC_AS_STAT));
+}
+
+static inline int nfsd_create_is_exclusive(int createmode)
+{
+	return createmode == NFS3_CREATE_EXCLUSIVE
+	       || createmode == NFS4_CREATE_EXCLUSIVE4_1;
+}
+
+#endif /* LINUX_NFSD_VFS_H */
diff --git a/fs/nfsd/xdr.h b/fs/nfsd/xdr.h
new file mode 100644
index 000000000..b8cc6a4b2
--- /dev/null
+++ b/fs/nfsd/xdr.h
@@ -0,0 +1,179 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* XDR types for nfsd. This is mainly a typing exercise. */
+
+#ifndef LINUX_NFSD_H
+#define LINUX_NFSD_H
+
+#include <linux/vfs.h>
+#include "nfsd.h"
+#include "nfsfh.h"
+
+struct nfsd_fhandle {
+	struct svc_fh		fh;
+};
+
+struct nfsd_sattrargs {
+	struct svc_fh		fh;
+	struct iattr		attrs;
+};
+
+struct nfsd_diropargs {
+	struct svc_fh		fh;
+	char *			name;
+	unsigned int		len;
+};
+
+struct nfsd_readargs {
+	struct svc_fh		fh;
+	__u32			offset;
+	__u32			count;
+	int			vlen;
+};
+
+struct nfsd_writeargs {
+	svc_fh			fh;
+	__u32			offset;
+	__u32			len;
+	struct kvec		first;
+};
+
+struct nfsd_createargs {
+	struct svc_fh		fh;
+	char *			name;
+	unsigned int		len;
+	struct iattr		attrs;
+};
+
+struct nfsd_renameargs {
+	struct svc_fh		ffh;
+	char *			fname;
+	unsigned int		flen;
+	struct svc_fh		tfh;
+	char *			tname;
+	unsigned int		tlen;
+};
+
+struct nfsd_readlinkargs {
+	struct svc_fh		fh;
+	char *			buffer;
+};
+	
+struct nfsd_linkargs {
+	struct svc_fh		ffh;
+	struct svc_fh		tfh;
+	char *			tname;
+	unsigned int		tlen;
+};
+
+struct nfsd_symlinkargs {
+	struct svc_fh		ffh;
+	char *			fname;
+	unsigned int		flen;
+	char *			tname;
+	unsigned int		tlen;
+	struct iattr		attrs;
+	struct kvec		first;
+};
+
+struct nfsd_readdirargs {
+	struct svc_fh		fh;
+	__u32			cookie;
+	__u32			count;
+	__be32 *		buffer;
+};
+
+struct nfsd_stat {
+	__be32			status;
+};
+
+struct nfsd_attrstat {
+	__be32			status;
+	struct svc_fh		fh;
+	struct kstat		stat;
+};
+
+struct nfsd_diropres  {
+	__be32			status;
+	struct svc_fh		fh;
+	struct kstat		stat;
+};
+
+struct nfsd_readlinkres {
+	__be32			status;
+	int			len;
+};
+
+struct nfsd_readres {
+	__be32			status;
+	struct svc_fh		fh;
+	unsigned long		count;
+	struct kstat		stat;
+};
+
+struct nfsd_readdirres {
+	__be32			status;
+
+	int			count;
+
+	struct readdir_cd	common;
+	__be32 *		buffer;
+	int			buflen;
+	__be32 *		offset;
+};
+
+struct nfsd_statfsres {
+	__be32			status;
+	struct kstatfs		stats;
+};
+
+/*
+ * Storage requirements for XDR arguments and results.
+ */
+union nfsd_xdrstore {
+	struct nfsd_sattrargs	sattr;
+	struct nfsd_diropargs	dirop;
+	struct nfsd_readargs	read;
+	struct nfsd_writeargs	write;
+	struct nfsd_createargs	create;
+	struct nfsd_renameargs	rename;
+	struct nfsd_linkargs	link;
+	struct nfsd_symlinkargs	symlink;
+	struct nfsd_readdirargs	readdir;
+};
+
+#define NFS2_SVC_XDRSIZE	sizeof(union nfsd_xdrstore)
+
+
+int nfssvc_decode_void(struct svc_rqst *, __be32 *);
+int nfssvc_decode_fhandle(struct svc_rqst *, __be32 *);
+int nfssvc_decode_sattrargs(struct svc_rqst *, __be32 *);
+int nfssvc_decode_diropargs(struct svc_rqst *, __be32 *);
+int nfssvc_decode_readargs(struct svc_rqst *, __be32 *);
+int nfssvc_decode_writeargs(struct svc_rqst *, __be32 *);
+int nfssvc_decode_createargs(struct svc_rqst *, __be32 *);
+int nfssvc_decode_renameargs(struct svc_rqst *, __be32 *);
+int nfssvc_decode_readlinkargs(struct svc_rqst *, __be32 *);
+int nfssvc_decode_linkargs(struct svc_rqst *, __be32 *);
+int nfssvc_decode_symlinkargs(struct svc_rqst *, __be32 *);
+int nfssvc_decode_readdirargs(struct svc_rqst *, __be32 *);
+int nfssvc_encode_void(struct svc_rqst *, __be32 *);
+int nfssvc_encode_stat(struct svc_rqst *, __be32 *);
+int nfssvc_encode_attrstat(struct svc_rqst *, __be32 *);
+int nfssvc_encode_diropres(struct svc_rqst *, __be32 *);
+int nfssvc_encode_readlinkres(struct svc_rqst *, __be32 *);
+int nfssvc_encode_readres(struct svc_rqst *, __be32 *);
+int nfssvc_encode_statfsres(struct svc_rqst *, __be32 *);
+int nfssvc_encode_readdirres(struct svc_rqst *, __be32 *);
+
+int nfssvc_encode_entry(void *, const char *name,
+			int namlen, loff_t offset, u64 ino, unsigned int);
+
+void nfssvc_release_attrstat(struct svc_rqst *rqstp);
+void nfssvc_release_diropres(struct svc_rqst *rqstp);
+void nfssvc_release_readres(struct svc_rqst *rqstp);
+
+/* Helper functions for NFSv2 ACL code */
+__be32 *nfs2svc_encode_fattr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp, struct kstat *stat);
+__be32 *nfs2svc_decode_fh(__be32 *p, struct svc_fh *fhp);
+
+#endif /* LINUX_NFSD_H */
diff --git a/fs/nfsd/xdr3.h b/fs/nfsd/xdr3.h
new file mode 100644
index 000000000..ae6fa6c9c
--- /dev/null
+++ b/fs/nfsd/xdr3.h
@@ -0,0 +1,324 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * XDR types for NFSv3 in nfsd.
+ *
+ * Copyright (C) 1996-1998, Olaf Kirch <okir@monad.swb.de>
+ */
+
+#ifndef _LINUX_NFSD_XDR3_H
+#define _LINUX_NFSD_XDR3_H
+
+#include "xdr.h"
+
+struct nfsd3_sattrargs {
+	struct svc_fh		fh;
+	struct iattr		attrs;
+	int			check_guard;
+	time64_t		guardtime;
+};
+
+struct nfsd3_diropargs {
+	struct svc_fh		fh;
+	char *			name;
+	unsigned int		len;
+};
+
+struct nfsd3_accessargs {
+	struct svc_fh		fh;
+	unsigned int		access;
+};
+
+struct nfsd3_readargs {
+	struct svc_fh		fh;
+	__u64			offset;
+	__u32			count;
+	int			vlen;
+};
+
+struct nfsd3_writeargs {
+	svc_fh			fh;
+	__u64			offset;
+	__u32			count;
+	int			stable;
+	__u32			len;
+	struct kvec		first;
+};
+
+struct nfsd3_createargs {
+	struct svc_fh		fh;
+	char *			name;
+	unsigned int		len;
+	int			createmode;
+	struct iattr		attrs;
+	__be32 *		verf;
+};
+
+struct nfsd3_mknodargs {
+	struct svc_fh		fh;
+	char *			name;
+	unsigned int		len;
+	__u32			ftype;
+	__u32			major, minor;
+	struct iattr		attrs;
+};
+
+struct nfsd3_renameargs {
+	struct svc_fh		ffh;
+	char *			fname;
+	unsigned int		flen;
+	struct svc_fh		tfh;
+	char *			tname;
+	unsigned int		tlen;
+};
+
+struct nfsd3_readlinkargs {
+	struct svc_fh		fh;
+	char *			buffer;
+};
+
+struct nfsd3_linkargs {
+	struct svc_fh		ffh;
+	struct svc_fh		tfh;
+	char *			tname;
+	unsigned int		tlen;
+};
+
+struct nfsd3_symlinkargs {
+	struct svc_fh		ffh;
+	char *			fname;
+	unsigned int		flen;
+	char *			tname;
+	unsigned int		tlen;
+	struct iattr		attrs;
+	struct kvec		first;
+};
+
+struct nfsd3_readdirargs {
+	struct svc_fh		fh;
+	__u64			cookie;
+	__u32			dircount;
+	__u32			count;
+	__be32 *		verf;
+	__be32 *		buffer;
+};
+
+struct nfsd3_commitargs {
+	struct svc_fh		fh;
+	__u64			offset;
+	__u32			count;
+};
+
+struct nfsd3_getaclargs {
+	struct svc_fh		fh;
+	int			mask;
+};
+
+struct posix_acl;
+struct nfsd3_setaclargs {
+	struct svc_fh		fh;
+	int			mask;
+	struct posix_acl	*acl_access;
+	struct posix_acl	*acl_default;
+};
+
+struct nfsd3_attrstat {
+	__be32			status;
+	struct svc_fh		fh;
+	struct kstat            stat;
+};
+
+/* LOOKUP, CREATE, MKDIR, SYMLINK, MKNOD */
+struct nfsd3_diropres  {
+	__be32			status;
+	struct svc_fh		dirfh;
+	struct svc_fh		fh;
+};
+
+struct nfsd3_accessres {
+	__be32			status;
+	struct svc_fh		fh;
+	__u32			access;
+	struct kstat		stat;
+};
+
+struct nfsd3_readlinkres {
+	__be32			status;
+	struct svc_fh		fh;
+	__u32			len;
+};
+
+struct nfsd3_readres {
+	__be32			status;
+	struct svc_fh		fh;
+	unsigned long		count;
+	__u32			eof;
+};
+
+struct nfsd3_writeres {
+	__be32			status;
+	struct svc_fh		fh;
+	unsigned long		count;
+	int			committed;
+	__be32			verf[2];
+};
+
+struct nfsd3_renameres {
+	__be32			status;
+	struct svc_fh		ffh;
+	struct svc_fh		tfh;
+};
+
+struct nfsd3_linkres {
+	__be32			status;
+	struct svc_fh		tfh;
+	struct svc_fh		fh;
+};
+
+struct nfsd3_readdirres {
+	__be32			status;
+	struct svc_fh		fh;
+	/* Just to save kmalloc on every readdirplus entry (svc_fh is a
+	 * little large for the stack): */
+	struct svc_fh		scratch;
+	int			count;
+	__be32			verf[2];
+
+	struct readdir_cd	common;
+	__be32 *		buffer;
+	int			buflen;
+	__be32 *		offset;
+	__be32 *		offset1;
+	struct svc_rqst *	rqstp;
+
+};
+
+struct nfsd3_fsstatres {
+	__be32			status;
+	struct kstatfs		stats;
+	__u32			invarsec;
+};
+
+struct nfsd3_fsinfores {
+	__be32			status;
+	__u32			f_rtmax;
+	__u32			f_rtpref;
+	__u32			f_rtmult;
+	__u32			f_wtmax;
+	__u32			f_wtpref;
+	__u32			f_wtmult;
+	__u32			f_dtpref;
+	__u64			f_maxfilesize;
+	__u32			f_properties;
+};
+
+struct nfsd3_pathconfres {
+	__be32			status;
+	__u32			p_link_max;
+	__u32			p_name_max;
+	__u32			p_no_trunc;
+	__u32			p_chown_restricted;
+	__u32			p_case_insensitive;
+	__u32			p_case_preserving;
+};
+
+struct nfsd3_commitres {
+	__be32			status;
+	struct svc_fh		fh;
+	__be32			verf[2];
+};
+
+struct nfsd3_getaclres {
+	__be32			status;
+	struct svc_fh		fh;
+	int			mask;
+	struct posix_acl	*acl_access;
+	struct posix_acl	*acl_default;
+	struct kstat		stat;
+};
+
+/* dummy type for release */
+struct nfsd3_fhandle_pair {
+	__u32			dummy;
+	struct svc_fh		fh1;
+	struct svc_fh		fh2;
+};
+
+/*
+ * Storage requirements for XDR arguments and results.
+ */
+union nfsd3_xdrstore {
+	struct nfsd3_sattrargs		sattrargs;
+	struct nfsd3_diropargs		diropargs;
+	struct nfsd3_readargs		readargs;
+	struct nfsd3_writeargs		writeargs;
+	struct nfsd3_createargs		createargs;
+	struct nfsd3_renameargs		renameargs;
+	struct nfsd3_linkargs		linkargs;
+	struct nfsd3_symlinkargs	symlinkargs;
+	struct nfsd3_readdirargs	readdirargs;
+	struct nfsd3_diropres 		diropres;
+	struct nfsd3_accessres		accessres;
+	struct nfsd3_readlinkres	readlinkres;
+	struct nfsd3_readres		readres;
+	struct nfsd3_writeres		writeres;
+	struct nfsd3_renameres		renameres;
+	struct nfsd3_linkres		linkres;
+	struct nfsd3_readdirres		readdirres;
+	struct nfsd3_fsstatres		fsstatres;
+	struct nfsd3_fsinfores		fsinfores;
+	struct nfsd3_pathconfres	pathconfres;
+	struct nfsd3_commitres		commitres;
+	struct nfsd3_getaclres		getaclres;
+};
+
+#define NFS3_SVC_XDRSIZE		sizeof(union nfsd3_xdrstore)
+
+int nfs3svc_decode_voidarg(struct svc_rqst *, __be32 *);
+int nfs3svc_decode_fhandle(struct svc_rqst *, __be32 *);
+int nfs3svc_decode_sattrargs(struct svc_rqst *, __be32 *);
+int nfs3svc_decode_diropargs(struct svc_rqst *, __be32 *);
+int nfs3svc_decode_accessargs(struct svc_rqst *, __be32 *);
+int nfs3svc_decode_readargs(struct svc_rqst *, __be32 *);
+int nfs3svc_decode_writeargs(struct svc_rqst *, __be32 *);
+int nfs3svc_decode_createargs(struct svc_rqst *, __be32 *);
+int nfs3svc_decode_mkdirargs(struct svc_rqst *, __be32 *);
+int nfs3svc_decode_mknodargs(struct svc_rqst *, __be32 *);
+int nfs3svc_decode_renameargs(struct svc_rqst *, __be32 *);
+int nfs3svc_decode_readlinkargs(struct svc_rqst *, __be32 *);
+int nfs3svc_decode_linkargs(struct svc_rqst *, __be32 *);
+int nfs3svc_decode_symlinkargs(struct svc_rqst *, __be32 *);
+int nfs3svc_decode_readdirargs(struct svc_rqst *, __be32 *);
+int nfs3svc_decode_readdirplusargs(struct svc_rqst *, __be32 *);
+int nfs3svc_decode_commitargs(struct svc_rqst *, __be32 *);
+int nfs3svc_encode_voidres(struct svc_rqst *, __be32 *);
+int nfs3svc_encode_attrstat(struct svc_rqst *, __be32 *);
+int nfs3svc_encode_wccstat(struct svc_rqst *, __be32 *);
+int nfs3svc_encode_diropres(struct svc_rqst *, __be32 *);
+int nfs3svc_encode_accessres(struct svc_rqst *, __be32 *);
+int nfs3svc_encode_readlinkres(struct svc_rqst *, __be32 *);
+int nfs3svc_encode_readres(struct svc_rqst *, __be32 *);
+int nfs3svc_encode_writeres(struct svc_rqst *, __be32 *);
+int nfs3svc_encode_createres(struct svc_rqst *, __be32 *);
+int nfs3svc_encode_renameres(struct svc_rqst *, __be32 *);
+int nfs3svc_encode_linkres(struct svc_rqst *, __be32 *);
+int nfs3svc_encode_readdirres(struct svc_rqst *, __be32 *);
+int nfs3svc_encode_fsstatres(struct svc_rqst *, __be32 *);
+int nfs3svc_encode_fsinfores(struct svc_rqst *, __be32 *);
+int nfs3svc_encode_pathconfres(struct svc_rqst *, __be32 *);
+int nfs3svc_encode_commitres(struct svc_rqst *, __be32 *);
+
+void nfs3svc_release_fhandle(struct svc_rqst *);
+void nfs3svc_release_fhandle2(struct svc_rqst *);
+int nfs3svc_encode_entry(void *, const char *name,
+				int namlen, loff_t offset, u64 ino,
+				unsigned int);
+int nfs3svc_encode_entry_plus(void *, const char *name,
+				int namlen, loff_t offset, u64 ino,
+				unsigned int);
+/* Helper functions for NFSv3 ACL code */
+__be32 *nfs3svc_encode_post_op_attr(struct svc_rqst *rqstp, __be32 *p,
+				struct svc_fh *fhp);
+__be32 *nfs3svc_decode_fh(__be32 *p, struct svc_fh *fhp);
+
+
+#endif /* _LINUX_NFSD_XDR3_H */
diff --git a/fs/nfsd/xdr4.h b/fs/nfsd/xdr4.h
new file mode 100644
index 000000000..679d40af1
--- /dev/null
+++ b/fs/nfsd/xdr4.h
@@ -0,0 +1,902 @@
+/*
+ *  Server-side types for NFSv4.
+ *
+ *  Copyright (c) 2002 The Regents of the University of Michigan.
+ *  All rights reserved.
+ *
+ *  Kendrick Smith <kmsmith@umich.edu>
+ *  Andy Adamson   <andros@umich.edu>
+ *
+ *  Redistribution and use in source and binary forms, with or without
+ *  modification, are permitted provided that the following conditions
+ *  are met:
+ *
+ *  1. Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *  2. Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *  3. Neither the name of the University nor the names of its
+ *     contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+ *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef _LINUX_NFSD_XDR4_H
+#define _LINUX_NFSD_XDR4_H
+
+#include "state.h"
+#include "nfsd.h"
+
+#define NFSD4_MAX_TAGLEN	128
+#define XDR_LEN(n)                     (((n) + 3) & ~3)
+
+#define CURRENT_STATE_ID_FLAG (1<<0)
+#define SAVED_STATE_ID_FLAG (1<<1)
+
+#define SET_CSTATE_FLAG(c, f) ((c)->sid_flags |= (f))
+#define HAS_CSTATE_FLAG(c, f) ((c)->sid_flags & (f))
+#define CLEAR_CSTATE_FLAG(c, f) ((c)->sid_flags &= ~(f))
+
+struct nfsd4_compound_state {
+	struct svc_fh		current_fh;
+	struct svc_fh		save_fh;
+	struct nfs4_stateowner	*replay_owner;
+	struct nfs4_client	*clp;
+	/* For sessions DRC */
+	struct nfsd4_session	*session;
+	struct nfsd4_slot	*slot;
+	int			data_offset;
+	bool                    spo_must_allowed;
+	size_t			iovlen;
+	u32			minorversion;
+	__be32			status;
+	stateid_t	current_stateid;
+	stateid_t	save_stateid;
+	/* to indicate current and saved state id presents */
+	u32		sid_flags;
+};
+
+static inline bool nfsd4_has_session(struct nfsd4_compound_state *cs)
+{
+	return cs->slot != NULL;
+}
+
+struct nfsd4_change_info {
+	u32		atomic;
+	bool		change_supported;
+	u32		before_ctime_sec;
+	u32		before_ctime_nsec;
+	u64		before_change;
+	u32		after_ctime_sec;
+	u32		after_ctime_nsec;
+	u64		after_change;
+};
+
+struct nfsd4_access {
+	u32		ac_req_access;      /* request */
+	u32		ac_supported;       /* response */
+	u32		ac_resp_access;     /* response */
+};
+
+struct nfsd4_close {
+	u32		cl_seqid;           /* request */
+	stateid_t	cl_stateid;         /* request+response */
+};
+
+struct nfsd4_commit {
+	u64		co_offset;          /* request */
+	u32		co_count;           /* request */
+	nfs4_verifier	co_verf;            /* response */
+};
+
+struct nfsd4_create {
+	u32		cr_namelen;         /* request */
+	char *		cr_name;            /* request */
+	u32		cr_type;            /* request */
+	union {                             /* request */
+		struct {
+			u32 datalen;
+			char *data;
+			struct kvec first;
+		} link;   /* NF4LNK */
+		struct {
+			u32 specdata1;
+			u32 specdata2;
+		} dev;    /* NF4BLK, NF4CHR */
+	} u;
+	u32		cr_bmval[3];        /* request */
+	struct iattr	cr_iattr;           /* request */
+	int		cr_umask;           /* request */
+	struct nfsd4_change_info  cr_cinfo; /* response */
+	struct nfs4_acl *cr_acl;
+	struct xdr_netobj cr_label;
+};
+#define cr_datalen	u.link.datalen
+#define cr_data		u.link.data
+#define cr_first	u.link.first
+#define cr_specdata1	u.dev.specdata1
+#define cr_specdata2	u.dev.specdata2
+
+struct nfsd4_delegreturn {
+	stateid_t	dr_stateid;
+};
+
+struct nfsd4_getattr {
+	u32		ga_bmval[3];        /* request */
+	struct svc_fh	*ga_fhp;            /* response */
+};
+
+struct nfsd4_link {
+	u32		li_namelen;         /* request */
+	char *		li_name;            /* request */
+	struct nfsd4_change_info  li_cinfo; /* response */
+};
+
+struct nfsd4_lock_denied {
+	clientid_t	ld_clientid;
+	struct xdr_netobj	ld_owner;
+	u64             ld_start;
+	u64             ld_length;
+	u32             ld_type;
+};
+
+struct nfsd4_lock {
+	/* request */
+	u32             lk_type;
+	u32             lk_reclaim;         /* boolean */
+	u64             lk_offset;
+	u64             lk_length;
+	u32             lk_is_new;
+	union {
+		struct {
+			u32             open_seqid;
+			stateid_t       open_stateid;
+			u32             lock_seqid;
+			clientid_t      clientid;
+			struct xdr_netobj owner;
+		} new;
+		struct {
+			stateid_t       lock_stateid;
+			u32             lock_seqid;
+		} old;
+	} v;
+
+	/* response */
+	union {
+		struct {
+			stateid_t               stateid;
+		} ok;
+		struct nfsd4_lock_denied        denied;
+	} u;
+};
+#define lk_new_open_seqid       v.new.open_seqid
+#define lk_new_open_stateid     v.new.open_stateid
+#define lk_new_lock_seqid       v.new.lock_seqid
+#define lk_new_clientid         v.new.clientid
+#define lk_new_owner            v.new.owner
+#define lk_old_lock_stateid     v.old.lock_stateid
+#define lk_old_lock_seqid       v.old.lock_seqid
+
+#define lk_resp_stateid u.ok.stateid
+#define lk_denied       u.denied
+
+
+struct nfsd4_lockt {
+	u32				lt_type;
+	clientid_t			lt_clientid;
+	struct xdr_netobj		lt_owner;
+	u64				lt_offset;
+	u64				lt_length;
+	struct nfsd4_lock_denied  	lt_denied;
+};
+
+ 
+struct nfsd4_locku {
+	u32             lu_type;
+	u32             lu_seqid;
+	stateid_t       lu_stateid;
+	u64             lu_offset;
+	u64             lu_length;
+};
+
+
+struct nfsd4_lookup {
+	u32		lo_len;             /* request */
+	char *		lo_name;            /* request */
+};
+
+struct nfsd4_putfh {
+	u32		pf_fhlen;           /* request */
+	char		*pf_fhval;          /* request */
+	bool		no_verify;	    /* represents foreigh fh */
+};
+
+struct nfsd4_getxattr {
+	char		*getxa_name;		/* request */
+	u32		getxa_len;		/* request */
+	void		*getxa_buf;
+};
+
+struct nfsd4_setxattr {
+	u32		setxa_flags;		/* request */
+	char		*setxa_name;		/* request */
+	char		*setxa_buf;		/* request */
+	u32		setxa_len;		/* request */
+	struct nfsd4_change_info  setxa_cinfo;	/* response */
+};
+
+struct nfsd4_removexattr {
+	char		*rmxa_name;		/* request */
+	struct nfsd4_change_info  rmxa_cinfo;	/* response */
+};
+
+struct nfsd4_listxattrs {
+	u64		lsxa_cookie;		/* request */
+	u32		lsxa_maxcount;		/* request */
+	char		*lsxa_buf;		/* unfiltered buffer (reply) */
+	u32		lsxa_len;		/* unfiltered len (reply) */
+};
+
+struct nfsd4_open {
+	u32		op_claim_type;      /* request */
+	struct xdr_netobj op_fname;	    /* request - everything but CLAIM_PREV */
+	u32		op_delegate_type;   /* request - CLAIM_PREV only */
+	stateid_t       op_delegate_stateid; /* request - response */
+	u32		op_why_no_deleg;    /* response - DELEG_NONE_EXT only */
+	u32		op_create;     	    /* request */
+	u32		op_createmode;      /* request */
+	int		op_umask;           /* request */
+	u32		op_bmval[3];        /* request */
+	struct iattr	op_iattr;           /* UNCHECKED4, GUARDED4, EXCLUSIVE4_1 */
+	nfs4_verifier	op_verf __attribute__((aligned(32)));
+					    /* EXCLUSIVE4 */
+	clientid_t	op_clientid;        /* request */
+	struct xdr_netobj op_owner;           /* request */
+	u32		op_seqid;           /* request */
+	u32		op_share_access;    /* request */
+	u32		op_share_deny;      /* request */
+	u32		op_deleg_want;      /* request */
+	stateid_t	op_stateid;         /* response */
+	__be32		op_xdr_error;       /* see nfsd4_open_omfg() */
+	u32		op_recall;          /* recall */
+	struct nfsd4_change_info  op_cinfo; /* response */
+	u32		op_rflags;          /* response */
+	bool		op_truncate;        /* used during processing */
+	bool		op_created;         /* used during processing */
+	struct nfs4_openowner *op_openowner; /* used during processing */
+	struct nfs4_file *op_file;          /* used during processing */
+	struct nfs4_ol_stateid *op_stp;	    /* used during processing */
+	struct nfs4_clnt_odstate *op_odstate; /* used during processing */
+	struct nfs4_acl *op_acl;
+	struct xdr_netobj op_label;
+};
+
+struct nfsd4_open_confirm {
+	stateid_t	oc_req_stateid		/* request */;
+	u32		oc_seqid    		/* request */;
+	stateid_t	oc_resp_stateid		/* response */;
+};
+
+struct nfsd4_open_downgrade {
+	stateid_t       od_stateid;
+	u32             od_seqid;
+	u32             od_share_access;	/* request */
+	u32		od_deleg_want;		/* request */
+	u32             od_share_deny;		/* request */
+};
+
+
+struct nfsd4_read {
+	stateid_t		rd_stateid;         /* request */
+	u64			rd_offset;          /* request */
+	u32			rd_length;          /* request */
+	int			rd_vlen;
+	struct nfsd_file	*rd_nf;
+	
+	struct svc_rqst		*rd_rqstp;          /* response */
+	struct svc_fh		*rd_fhp;             /* response */
+};
+
+struct nfsd4_readdir {
+	u64		rd_cookie;          /* request */
+	nfs4_verifier	rd_verf;            /* request */
+	u32		rd_dircount;        /* request */
+	u32		rd_maxcount;        /* request */
+	u32		rd_bmval[3];        /* request */
+	struct svc_rqst *rd_rqstp;          /* response */
+	struct svc_fh * rd_fhp;             /* response */
+
+	struct readdir_cd	common;
+	struct xdr_stream	*xdr;
+	int			cookie_offset;
+};
+
+struct nfsd4_release_lockowner {
+	clientid_t        rl_clientid;
+	struct xdr_netobj rl_owner;
+};
+struct nfsd4_readlink {
+	struct svc_rqst *rl_rqstp;          /* request */
+	struct svc_fh *	rl_fhp;             /* request */
+};
+
+struct nfsd4_remove {
+	u32		rm_namelen;         /* request */
+	char *		rm_name;            /* request */
+	struct nfsd4_change_info  rm_cinfo; /* response */
+};
+
+struct nfsd4_rename {
+	u32		rn_snamelen;        /* request */
+	char *		rn_sname;           /* request */
+	u32		rn_tnamelen;        /* request */
+	char *		rn_tname;           /* request */
+	struct nfsd4_change_info  rn_sinfo; /* response */
+	struct nfsd4_change_info  rn_tinfo; /* response */
+};
+
+struct nfsd4_secinfo {
+	u32 si_namelen;					/* request */
+	char *si_name;					/* request */
+	struct svc_export *si_exp;			/* response */
+};
+
+struct nfsd4_secinfo_no_name {
+	u32 sin_style;					/* request */
+	struct svc_export *sin_exp;			/* response */
+};
+
+struct nfsd4_setattr {
+	stateid_t	sa_stateid;         /* request */
+	u32		sa_bmval[3];        /* request */
+	struct iattr	sa_iattr;           /* request */
+	struct nfs4_acl *sa_acl;
+	struct xdr_netobj sa_label;
+};
+
+struct nfsd4_setclientid {
+	nfs4_verifier	se_verf;            /* request */
+	struct xdr_netobj se_name;
+	u32		se_callback_prog;   /* request */
+	u32		se_callback_netid_len;  /* request */
+	char *		se_callback_netid_val;  /* request */
+	u32		se_callback_addr_len;   /* request */
+	char *		se_callback_addr_val;   /* request */
+	u32		se_callback_ident;  /* request */
+	clientid_t	se_clientid;        /* response */
+	nfs4_verifier	se_confirm;         /* response */
+};
+
+struct nfsd4_setclientid_confirm {
+	clientid_t	sc_clientid;
+	nfs4_verifier	sc_confirm;
+};
+
+struct nfsd4_saved_compoundargs {
+	__be32 *p;
+	__be32 *end;
+	int pagelen;
+	struct page **pagelist;
+};
+
+struct nfsd4_test_stateid_id {
+	__be32			ts_id_status;
+	stateid_t		ts_id_stateid;
+	struct list_head	ts_id_list;
+};
+
+struct nfsd4_test_stateid {
+	u32		ts_num_ids;
+	struct list_head ts_stateid_list;
+};
+
+struct nfsd4_free_stateid {
+	stateid_t	fr_stateid;         /* request */
+};
+
+/* also used for NVERIFY */
+struct nfsd4_verify {
+	u32		ve_bmval[3];        /* request */
+	u32		ve_attrlen;         /* request */
+	char *		ve_attrval;         /* request */
+};
+
+struct nfsd4_write {
+	stateid_t	wr_stateid;         /* request */
+	u64		wr_offset;          /* request */
+	u32		wr_stable_how;      /* request */
+	u32		wr_buflen;          /* request */
+	struct kvec	wr_head;
+	struct page **	wr_pagelist;        /* request */
+
+	u32		wr_bytes_written;   /* response */
+	u32		wr_how_written;     /* response */
+	nfs4_verifier	wr_verifier;        /* response */
+};
+
+struct nfsd4_exchange_id {
+	nfs4_verifier	verifier;
+	struct xdr_netobj clname;
+	u32		flags;
+	clientid_t	clientid;
+	u32		seqid;
+	int		spa_how;
+	u32             spo_must_enforce[3];
+	u32             spo_must_allow[3];
+	struct xdr_netobj nii_domain;
+	struct xdr_netobj nii_name;
+	struct timespec64 nii_time;
+};
+
+struct nfsd4_sequence {
+	struct nfs4_sessionid	sessionid;		/* request/response */
+	u32			seqid;			/* request/response */
+	u32			slotid;			/* request/response */
+	u32			maxslots;		/* request/response */
+	u32			cachethis;		/* request */
+#if 0
+	u32			target_maxslots;	/* response */
+#endif /* not yet */
+	u32			status_flags;		/* response */
+};
+
+struct nfsd4_destroy_session {
+	struct nfs4_sessionid	sessionid;
+};
+
+struct nfsd4_destroy_clientid {
+	clientid_t clientid;
+};
+
+struct nfsd4_reclaim_complete {
+	u32 rca_one_fs;
+};
+
+struct nfsd4_deviceid {
+	u64			fsid_idx;
+	u32			generation;
+	u32			pad;
+};
+
+struct nfsd4_layout_seg {
+	u32			iomode;
+	u64			offset;
+	u64			length;
+};
+
+struct nfsd4_getdeviceinfo {
+	struct nfsd4_deviceid	gd_devid;	/* request */
+	u32			gd_layout_type;	/* request */
+	u32			gd_maxcount;	/* request */
+	u32			gd_notify_types;/* request - response */
+	void			*gd_device;	/* response */
+};
+
+struct nfsd4_layoutget {
+	u64			lg_minlength;	/* request */
+	u32			lg_signal;	/* request */
+	u32			lg_layout_type;	/* request */
+	u32			lg_maxcount;	/* request */
+	stateid_t		lg_sid;		/* request/response */
+	struct nfsd4_layout_seg	lg_seg;		/* request/response */
+	void			*lg_content;	/* response */
+};
+
+struct nfsd4_layoutcommit {
+	stateid_t		lc_sid;		/* request */
+	struct nfsd4_layout_seg	lc_seg;		/* request */
+	u32			lc_reclaim;	/* request */
+	u32			lc_newoffset;	/* request */
+	u64			lc_last_wr;	/* request */
+	struct timespec64	lc_mtime;	/* request */
+	u32			lc_layout_type;	/* request */
+	u32			lc_up_len;	/* layout length */
+	void			*lc_up_layout;	/* decoded by callback */
+	u32			lc_size_chg;	/* boolean for response */
+	u64			lc_newsize;	/* response */
+};
+
+struct nfsd4_layoutreturn {
+	u32			lr_return_type;	/* request */
+	u32			lr_layout_type;	/* request */
+	struct nfsd4_layout_seg	lr_seg;		/* request */
+	u32			lr_reclaim;	/* request */
+	u32			lrf_body_len;	/* request */
+	void			*lrf_body;	/* request */
+	stateid_t		lr_sid;		/* request/response */
+	u32			lrs_present;	/* response */
+};
+
+struct nfsd4_fallocate {
+	/* request */
+	stateid_t	falloc_stateid;
+	loff_t		falloc_offset;
+	u64		falloc_length;
+};
+
+struct nfsd4_clone {
+	/* request */
+	stateid_t	cl_src_stateid;
+	stateid_t	cl_dst_stateid;
+	u64		cl_src_pos;
+	u64		cl_dst_pos;
+	u64		cl_count;
+};
+
+struct nfsd42_write_res {
+	u64			wr_bytes_written;
+	u32			wr_stable_how;
+	nfs4_verifier		wr_verifier;
+	stateid_t		cb_stateid;
+};
+
+struct nfsd4_copy {
+	/* request */
+	stateid_t		cp_src_stateid;
+	stateid_t		cp_dst_stateid;
+	u64			cp_src_pos;
+	u64			cp_dst_pos;
+	u64			cp_count;
+	struct nl4_server	cp_src;
+	bool			cp_intra;
+
+	/* both */
+	bool		cp_synchronous;
+
+	/* response */
+	struct nfsd42_write_res	cp_res;
+
+	/* for cb_offload */
+	struct nfsd4_callback	cp_cb;
+	__be32			nfserr;
+	struct knfsd_fh		fh;
+
+	struct nfs4_client      *cp_clp;
+
+	struct nfsd_file        *nf_src;
+	struct nfsd_file        *nf_dst;
+
+	copy_stateid_t		cp_stateid;
+
+	struct list_head	copies;
+	struct task_struct	*copy_task;
+	refcount_t		refcount;
+	bool			stopped;
+
+	struct vfsmount		*ss_mnt;
+	struct nfs_fh		c_fh;
+	nfs4_stateid		stateid;
+};
+extern bool inter_copy_offload_enable;
+
+struct nfsd4_seek {
+	/* request */
+	stateid_t	seek_stateid;
+	loff_t		seek_offset;
+	u32		seek_whence;
+
+	/* response */
+	u32		seek_eof;
+	loff_t		seek_pos;
+};
+
+struct nfsd4_offload_status {
+	/* request */
+	stateid_t	stateid;
+
+	/* response */
+	u64		count;
+	u32		status;
+};
+
+struct nfsd4_copy_notify {
+	/* request */
+	stateid_t		cpn_src_stateid;
+	struct nl4_server	cpn_dst;
+
+	/* response */
+	stateid_t		cpn_cnr_stateid;
+	u64			cpn_sec;
+	u32			cpn_nsec;
+	struct nl4_server	cpn_src;
+};
+
+struct nfsd4_op {
+	int					opnum;
+	const struct nfsd4_operation *		opdesc;
+	__be32					status;
+	union nfsd4_op_u {
+		struct nfsd4_access		access;
+		struct nfsd4_close		close;
+		struct nfsd4_commit		commit;
+		struct nfsd4_create		create;
+		struct nfsd4_delegreturn	delegreturn;
+		struct nfsd4_getattr		getattr;
+		struct svc_fh *			getfh;
+		struct nfsd4_link		link;
+		struct nfsd4_lock		lock;
+		struct nfsd4_lockt		lockt;
+		struct nfsd4_locku		locku;
+		struct nfsd4_lookup		lookup;
+		struct nfsd4_verify		nverify;
+		struct nfsd4_open		open;
+		struct nfsd4_open_confirm	open_confirm;
+		struct nfsd4_open_downgrade	open_downgrade;
+		struct nfsd4_putfh		putfh;
+		struct nfsd4_read		read;
+		struct nfsd4_readdir		readdir;
+		struct nfsd4_readlink		readlink;
+		struct nfsd4_remove		remove;
+		struct nfsd4_rename		rename;
+		clientid_t			renew;
+		struct nfsd4_secinfo		secinfo;
+		struct nfsd4_setattr		setattr;
+		struct nfsd4_setclientid	setclientid;
+		struct nfsd4_setclientid_confirm setclientid_confirm;
+		struct nfsd4_verify		verify;
+		struct nfsd4_write		write;
+		struct nfsd4_release_lockowner	release_lockowner;
+
+		/* NFSv4.1 */
+		struct nfsd4_exchange_id	exchange_id;
+		struct nfsd4_backchannel_ctl	backchannel_ctl;
+		struct nfsd4_bind_conn_to_session bind_conn_to_session;
+		struct nfsd4_create_session	create_session;
+		struct nfsd4_destroy_session	destroy_session;
+		struct nfsd4_destroy_clientid	destroy_clientid;
+		struct nfsd4_sequence		sequence;
+		struct nfsd4_reclaim_complete	reclaim_complete;
+		struct nfsd4_test_stateid	test_stateid;
+		struct nfsd4_free_stateid	free_stateid;
+		struct nfsd4_getdeviceinfo	getdeviceinfo;
+		struct nfsd4_layoutget		layoutget;
+		struct nfsd4_layoutcommit	layoutcommit;
+		struct nfsd4_layoutreturn	layoutreturn;
+		struct nfsd4_secinfo_no_name	secinfo_no_name;
+
+		/* NFSv4.2 */
+		struct nfsd4_fallocate		allocate;
+		struct nfsd4_fallocate		deallocate;
+		struct nfsd4_clone		clone;
+		struct nfsd4_copy		copy;
+		struct nfsd4_offload_status	offload_status;
+		struct nfsd4_copy_notify	copy_notify;
+		struct nfsd4_seek		seek;
+
+		struct nfsd4_getxattr		getxattr;
+		struct nfsd4_setxattr		setxattr;
+		struct nfsd4_listxattrs		listxattrs;
+		struct nfsd4_removexattr	removexattr;
+	} u;
+	struct nfs4_replay *			replay;
+};
+
+bool nfsd4_cache_this_op(struct nfsd4_op *);
+
+/*
+ * Memory needed just for the duration of processing one compound:
+ */
+struct svcxdr_tmpbuf {
+	struct svcxdr_tmpbuf *next;
+	char buf[];
+};
+
+struct nfsd4_compoundargs {
+	/* scratch variables for XDR decode */
+	__be32 *			p;
+	__be32 *			end;
+	struct page **			pagelist;
+	int				pagelen;
+	bool				tail;
+	__be32				tmp[8];
+	__be32 *			tmpp;
+	struct svcxdr_tmpbuf		*to_free;
+
+	struct svc_rqst			*rqstp;
+
+	u32				taglen;
+	char *				tag;
+	u32				minorversion;
+	u32				opcnt;
+	struct nfsd4_op			*ops;
+	struct nfsd4_op			iops[8];
+	int				cachetype;
+};
+
+struct nfsd4_compoundres {
+	/* scratch variables for XDR encode */
+	struct xdr_stream		xdr;
+	struct svc_rqst *		rqstp;
+
+	u32				taglen;
+	char *				tag;
+	u32				opcnt;
+	__be32 *			tagp; /* tag, opcount encode location */
+	struct nfsd4_compound_state	cstate;
+};
+
+static inline bool nfsd4_is_solo_sequence(struct nfsd4_compoundres *resp)
+{
+	struct nfsd4_compoundargs *args = resp->rqstp->rq_argp;
+	return resp->opcnt == 1 && args->ops[0].opnum == OP_SEQUENCE;
+}
+
+/*
+ * The session reply cache only needs to cache replies that the client
+ * actually asked us to.  But it's almost free for us to cache compounds
+ * consisting of only a SEQUENCE op, so we may as well cache those too.
+ * Also, the protocol doesn't give us a convenient response in the case
+ * of a replay of a solo SEQUENCE op that wasn't cached
+ * (RETRY_UNCACHED_REP can only be returned in the second op of a
+ * compound).
+ */
+static inline bool nfsd4_cache_this(struct nfsd4_compoundres *resp)
+{
+	return (resp->cstate.slot->sl_flags & NFSD4_SLOT_CACHETHIS)
+		|| nfsd4_is_solo_sequence(resp);
+}
+
+static inline bool nfsd4_last_compound_op(struct svc_rqst *rqstp)
+{
+	struct nfsd4_compoundres *resp = rqstp->rq_resp;
+	struct nfsd4_compoundargs *argp = rqstp->rq_argp;
+
+	return argp->opcnt == resp->opcnt;
+}
+
+const struct nfsd4_operation *OPDESC(struct nfsd4_op *op);
+int nfsd4_max_reply(struct svc_rqst *rqstp, struct nfsd4_op *op);
+void warn_on_nonidempotent_op(struct nfsd4_op *op);
+
+#define NFS4_SVC_XDRSIZE		sizeof(struct nfsd4_compoundargs)
+
+static inline void
+set_change_info(struct nfsd4_change_info *cinfo, struct svc_fh *fhp)
+{
+	BUG_ON(!fhp->fh_pre_saved);
+	cinfo->atomic = (u32)fhp->fh_post_saved;
+	cinfo->change_supported = IS_I_VERSION(d_inode(fhp->fh_dentry));
+
+	cinfo->before_change = fhp->fh_pre_change;
+	cinfo->after_change = fhp->fh_post_change;
+	cinfo->before_ctime_sec = fhp->fh_pre_ctime.tv_sec;
+	cinfo->before_ctime_nsec = fhp->fh_pre_ctime.tv_nsec;
+	cinfo->after_ctime_sec = fhp->fh_post_attr.ctime.tv_sec;
+	cinfo->after_ctime_nsec = fhp->fh_post_attr.ctime.tv_nsec;
+
+}
+
+
+bool nfsd4_mach_creds_match(struct nfs4_client *cl, struct svc_rqst *rqstp);
+int nfs4svc_decode_voidarg(struct svc_rqst *, __be32 *);
+int nfs4svc_encode_voidres(struct svc_rqst *, __be32 *);
+int nfs4svc_decode_compoundargs(struct svc_rqst *, __be32 *);
+int nfs4svc_encode_compoundres(struct svc_rqst *, __be32 *);
+__be32 nfsd4_check_resp_size(struct nfsd4_compoundres *, u32);
+void nfsd4_encode_operation(struct nfsd4_compoundres *, struct nfsd4_op *);
+void nfsd4_encode_replay(struct xdr_stream *xdr, struct nfsd4_op *op);
+__be32 nfsd4_encode_fattr_to_buf(__be32 **p, int words,
+		struct svc_fh *fhp, struct svc_export *exp,
+		struct dentry *dentry,
+		u32 *bmval, struct svc_rqst *, int ignore_crossmnt);
+extern __be32 nfsd4_setclientid(struct svc_rqst *rqstp,
+		struct nfsd4_compound_state *, union nfsd4_op_u *u);
+extern __be32 nfsd4_setclientid_confirm(struct svc_rqst *rqstp,
+		struct nfsd4_compound_state *, union nfsd4_op_u *u);
+extern __be32 nfsd4_exchange_id(struct svc_rqst *rqstp,
+		struct nfsd4_compound_state *, union nfsd4_op_u *u);
+extern __be32 nfsd4_backchannel_ctl(struct svc_rqst *,
+		struct nfsd4_compound_state *, union nfsd4_op_u *u);
+extern __be32 nfsd4_bind_conn_to_session(struct svc_rqst *,
+		struct nfsd4_compound_state *, union nfsd4_op_u *u);
+extern __be32 nfsd4_create_session(struct svc_rqst *,
+		struct nfsd4_compound_state *, union nfsd4_op_u *u);
+extern __be32 nfsd4_sequence(struct svc_rqst *,
+		struct nfsd4_compound_state *, union nfsd4_op_u *u);
+extern void nfsd4_sequence_done(struct nfsd4_compoundres *resp);
+extern __be32 nfsd4_destroy_session(struct svc_rqst *,
+		struct nfsd4_compound_state *, union nfsd4_op_u *u);
+extern __be32 nfsd4_destroy_clientid(struct svc_rqst *, struct nfsd4_compound_state *,
+		union nfsd4_op_u *u);
+__be32 nfsd4_reclaim_complete(struct svc_rqst *, struct nfsd4_compound_state *,
+		union nfsd4_op_u *u);
+extern __be32 nfsd4_process_open1(struct nfsd4_compound_state *,
+		struct nfsd4_open *open, struct nfsd_net *nn);
+extern __be32 nfsd4_process_open2(struct svc_rqst *rqstp,
+		struct svc_fh *current_fh, struct nfsd4_open *open);
+extern void nfsd4_cstate_clear_replay(struct nfsd4_compound_state *cstate);
+extern void nfsd4_cleanup_open_state(struct nfsd4_compound_state *cstate,
+		struct nfsd4_open *open);
+extern __be32 nfsd4_open_confirm(struct svc_rqst *rqstp,
+		struct nfsd4_compound_state *, union nfsd4_op_u *u);
+extern __be32 nfsd4_close(struct svc_rqst *rqstp, struct nfsd4_compound_state *,
+		union nfsd4_op_u *u);
+extern __be32 nfsd4_open_downgrade(struct svc_rqst *rqstp,
+		struct nfsd4_compound_state *, union nfsd4_op_u *u);
+extern __be32 nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *,
+		union nfsd4_op_u *u);
+extern __be32 nfsd4_lockt(struct svc_rqst *rqstp, struct nfsd4_compound_state *,
+		union nfsd4_op_u *u);
+extern __be32 nfsd4_locku(struct svc_rqst *rqstp, struct nfsd4_compound_state *,
+		union nfsd4_op_u *u);
+extern __be32
+nfsd4_release_lockowner(struct svc_rqst *rqstp,
+		struct nfsd4_compound_state *, union nfsd4_op_u *u);
+extern void nfsd4_release_compoundargs(struct svc_rqst *rqstp);
+extern __be32 nfsd4_delegreturn(struct svc_rqst *rqstp,
+		struct nfsd4_compound_state *, union nfsd4_op_u *u);
+extern __be32 nfsd4_renew(struct svc_rqst *rqstp, struct nfsd4_compound_state *,
+		union nfsd4_op_u *u);
+extern __be32 nfsd4_test_stateid(struct svc_rqst *rqstp,
+		struct nfsd4_compound_state *, union nfsd4_op_u *);
+extern __be32 nfsd4_free_stateid(struct svc_rqst *rqstp,
+		struct nfsd4_compound_state *, union nfsd4_op_u *);
+extern void nfsd4_bump_seqid(struct nfsd4_compound_state *, __be32 nfserr);
+
+enum nfsd4_op_flags {
+	ALLOWED_WITHOUT_FH = 1 << 0,    /* No current filehandle required */
+	ALLOWED_ON_ABSENT_FS = 1 << 1,  /* ops processed on absent fs */
+	ALLOWED_AS_FIRST_OP = 1 << 2,   /* ops reqired first in compound */
+	/* For rfc 5661 section 2.6.3.1.1: */
+	OP_HANDLES_WRONGSEC = 1 << 3,
+	OP_IS_PUTFH_LIKE = 1 << 4,
+	/*
+	 * These are the ops whose result size we estimate before
+	 * encoding, to avoid performing an op then not being able to
+	 * respond or cache a response.  This includes writes and setattrs
+	 * as well as the operations usually called "nonidempotent":
+	 */
+	OP_MODIFIES_SOMETHING = 1 << 5,
+	/*
+	 * Cache compounds containing these ops in the xid-based drc:
+	 * We use the DRC for compounds containing non-idempotent
+	 * operations, *except* those that are 4.1-specific (since
+	 * sessions provide their own EOS), and except for stateful
+	 * operations other than setclientid and setclientid_confirm
+	 * (since sequence numbers provide EOS for open, lock, etc in
+	 * the v4.0 case).
+	 */
+	OP_CACHEME = 1 << 6,
+	/*
+	 * These are ops which clear current state id.
+	 */
+	OP_CLEAR_STATEID = 1 << 7,
+	/* Most ops return only an error on failure; some may do more: */
+	OP_NONTRIVIAL_ERROR_ENCODE = 1 << 8,
+};
+
+struct nfsd4_operation {
+	__be32 (*op_func)(struct svc_rqst *, struct nfsd4_compound_state *,
+			union nfsd4_op_u *);
+	void (*op_release)(union nfsd4_op_u *);
+	u32 op_flags;
+	char *op_name;
+	/* Try to get response size before operation */
+	u32 (*op_rsize_bop)(struct svc_rqst *, struct nfsd4_op *);
+	void (*op_get_currentstateid)(struct nfsd4_compound_state *,
+			union nfsd4_op_u *);
+	void (*op_set_currentstateid)(struct nfsd4_compound_state *,
+			union nfsd4_op_u *);
+};
+
+
+#endif
+
+/*
+ * Local variables:
+ *  c-basic-offset: 8
+ * End:
+ */
diff --git a/fs/nfsd/xdr4cb.h b/fs/nfsd/xdr4cb.h
new file mode 100644
index 000000000..547cf07cf
--- /dev/null
+++ b/fs/nfsd/xdr4cb.h
@@ -0,0 +1,50 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#define NFS4_MAXTAGLEN		20
+
+#define NFS4_enc_cb_null_sz		0
+#define NFS4_dec_cb_null_sz		0
+#define cb_compound_enc_hdr_sz		4
+#define cb_compound_dec_hdr_sz		(3 + (NFS4_MAXTAGLEN >> 2))
+#define sessionid_sz			(NFS4_MAX_SESSIONID_LEN >> 2)
+#define cb_sequence_enc_sz		(sessionid_sz + 4 +             \
+					1 /* no referring calls list yet */)
+#define cb_sequence_dec_sz		(op_dec_sz + sessionid_sz + 4)
+
+#define op_enc_sz			1
+#define op_dec_sz			2
+#define enc_nfs4_fh_sz			(1 + (NFS4_FHSIZE >> 2))
+#define enc_stateid_sz			(NFS4_STATEID_SIZE >> 2)
+#define NFS4_enc_cb_recall_sz		(cb_compound_enc_hdr_sz +       \
+					cb_sequence_enc_sz +            \
+					1 + enc_stateid_sz +            \
+					enc_nfs4_fh_sz)
+
+#define NFS4_dec_cb_recall_sz		(cb_compound_dec_hdr_sz  +      \
+					cb_sequence_dec_sz +            \
+					op_dec_sz)
+#define NFS4_enc_cb_layout_sz		(cb_compound_enc_hdr_sz +       \
+					cb_sequence_enc_sz +            \
+					1 + 3 +                         \
+					enc_nfs4_fh_sz + 4)
+#define NFS4_dec_cb_layout_sz		(cb_compound_dec_hdr_sz  +      \
+					cb_sequence_dec_sz +            \
+					op_dec_sz)
+
+#define NFS4_enc_cb_notify_lock_sz	(cb_compound_enc_hdr_sz +        \
+					cb_sequence_enc_sz +             \
+					2 + 1 +				 \
+					XDR_QUADLEN(NFS4_OPAQUE_LIMIT) + \
+					enc_nfs4_fh_sz)
+#define NFS4_dec_cb_notify_lock_sz	(cb_compound_dec_hdr_sz  +      \
+					cb_sequence_dec_sz +            \
+					op_dec_sz)
+#define enc_cb_offload_info_sz		(1 + 1 + 2 + 1 +		\
+					XDR_QUADLEN(NFS4_VERIFIER_SIZE))
+#define NFS4_enc_cb_offload_sz		(cb_compound_enc_hdr_sz +       \
+					cb_sequence_enc_sz +            \
+					enc_nfs4_fh_sz +		\
+					enc_stateid_sz +		\
+					enc_cb_offload_info_sz)
+#define NFS4_dec_cb_offload_sz		(cb_compound_dec_hdr_sz  +      \
+					cb_sequence_dec_sz +            \
+					op_dec_sz)