Adding upstream version 5.10.209.upstream/5.10.209upstream

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

90 files changed, 78877 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,
+};