Adding upstream version 6.6.15.upstream/6.6.15

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

1 files changed, 904 insertions, 0 deletions

diff --git a/fs/nfs/file.c b/fs/nfs/file.c
new file mode 100644
index 0000000000..3f97688104
--- /dev/null
+++ b/fs/nfs/file.c
@@ -0,0 +1,904 @@
+// 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 <linux/filelock.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;
+
+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);
+	if (res == 0)
+		filp->f_mode |= FMODE_CAN_ODIRECT;
+	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);
+	nfs_fscache_release_file(inode, filp);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nfs_file_release);
+
+/**
+ * nfs_revalidate_file_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_INVALID_SIZE))
+		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);
+
+ssize_t
+nfs_file_splice_read(struct file *in, loff_t *ppos, struct pipe_inode_info *pipe,
+		     size_t len, unsigned int flags)
+{
+	struct inode *inode = file_inode(in);
+	ssize_t result;
+
+	dprintk("NFS: splice_read(%pD2, %zu@%llu)\n", in, len, *ppos);
+
+	nfs_start_io_read(inode);
+	result = nfs_revalidate_mapping(inode, in->f_mapping);
+	if (!result) {
+		result = filemap_splice_read(in, ppos, pipe, len, flags);
+		if (result > 0)
+			nfs_add_stats(inode, NFSIOS_NORMALREADBYTES, result);
+	}
+	nfs_end_io_read(inode);
+	return result;
+}
+EXPORT_SYMBOL_GPL(nfs_file_splice_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 inode *inode = file_inode(file);
+	struct nfs_inode *nfsi = NFS_I(inode);
+	long save_nredirtied = atomic_long_read(&nfsi->redirtied_pages);
+	long nredirtied;
+	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;
+		nredirtied = atomic_long_read(&nfsi->redirtied_pages);
+		if (nredirtied == save_nredirtied)
+			break;
+		save_nredirtied = nredirtied;
+	}
+
+	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_folio_is_full_write(struct folio *folio, loff_t pos,
+				    unsigned int len)
+{
+	unsigned int pglen = nfs_folio_length(folio);
+	unsigned int offset = offset_in_folio(folio, pos);
+	unsigned int end = offset + len;
+
+	return !pglen || (end >= pglen && !offset);
+}
+
+static bool nfs_want_read_modify_write(struct file *file, struct folio *folio,
+				       loff_t pos, unsigned int len)
+{
+	/*
+	 * Up-to-date pages, those with ongoing or full-page write
+	 * don't need read/modify/write
+	 */
+	if (folio_test_uptodate(folio) || folio_test_private(folio) ||
+	    nfs_folio_is_full_write(folio, pos, len))
+		return false;
+
+	if (pnfs_ld_read_whole_page(file_inode(file)))
+		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, struct page **pagep,
+			   void **fsdata)
+{
+	struct folio *folio;
+	int once_thru = 0;
+	int ret;
+
+	dfprintk(PAGECACHE, "NFS: write_begin(%pD2(%lu), %u@%lld)\n",
+		file, mapping->host->i_ino, len, (long long) pos);
+
+start:
+	folio = __filemap_get_folio(mapping, pos >> PAGE_SHIFT, FGP_WRITEBEGIN,
+				    mapping_gfp_mask(mapping));
+	if (IS_ERR(folio))
+		return PTR_ERR(folio);
+	*pagep = &folio->page;
+
+	ret = nfs_flush_incompatible(file, folio);
+	if (ret) {
+		folio_unlock(folio);
+		folio_put(folio);
+	} else if (!once_thru &&
+		   nfs_want_read_modify_write(file, folio, pos, len)) {
+		once_thru = 1;
+		ret = nfs_read_folio(file, folio);
+		folio_put(folio);
+		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)
+{
+	struct nfs_open_context *ctx = nfs_file_open_context(file);
+	struct folio *folio = page_folio(page);
+	unsigned offset = offset_in_folio(folio, pos);
+	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 (!folio_test_uptodate(folio)) {
+		size_t fsize = folio_size(folio);
+		unsigned pglen = nfs_folio_length(folio);
+		unsigned end = offset + copied;
+
+		if (pglen == 0) {
+			folio_zero_segments(folio, 0, offset, end, fsize);
+			folio_mark_uptodate(folio);
+		} else if (end >= pglen) {
+			folio_zero_segment(folio, end, fsize);
+			if (offset == 0)
+				folio_mark_uptodate(folio);
+		} else
+			folio_zero_segment(folio, pglen, fsize);
+	}
+
+	status = nfs_update_folio(file, folio, offset, copied);
+
+	folio_unlock(folio);
+	folio_put(folio);
+
+	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_folio(struct folio *folio, size_t offset,
+				size_t length)
+{
+	struct inode *inode = folio_file_mapping(folio)->host;
+	dfprintk(PAGECACHE, "NFS: invalidate_folio(%lu, %zu, %zu)\n",
+		 folio->index, offset, length);
+
+	if (offset != 0 || length < folio_size(folio))
+		return;
+	/* Cancel any unstarted writes on this page */
+	nfs_wb_folio_cancel(inode, folio);
+	folio_wait_fscache(folio);
+	trace_nfs_invalidate_folio(inode, folio);
+}
+
+/*
+ * Attempt to release the private state associated with a folio
+ * - Called if either private or fscache flags are set on the folio
+ * - Caller holds folio lock
+ * - Return true (may release folio) or false (may not)
+ */
+static bool nfs_release_folio(struct folio *folio, gfp_t gfp)
+{
+	dfprintk(PAGECACHE, "NFS: release_folio(%p)\n", folio);
+
+	/* If the private flag is set, then the folio is not freeable */
+	if (folio_test_private(folio)) {
+		if ((current_gfp_context(gfp) & GFP_KERNEL) != GFP_KERNEL ||
+		    current_is_kswapd())
+			return false;
+		if (nfs_wb_folio(folio_file_mapping(folio)->host, folio) < 0)
+			return false;
+	}
+	return nfs_fscache_release_folio(folio, gfp);
+}
+
+static void nfs_check_dirty_writeback(struct folio *folio,
+				bool *dirty, bool *writeback)
+{
+	struct nfs_inode *nfsi;
+	struct address_space *mapping = folio->mapping;
+
+	/*
+	 * Check if an unstable folio is currently being committed and
+	 * if so, have the VM treat it as if the folio is under writeback
+	 * so it will not block due to folios that will shortly be freeable.
+	 */
+	nfsi = NFS_I(mapping->host);
+	if (atomic_read(&nfsi->commit_info.rpcs_out)) {
+		*writeback = true;
+		return;
+	}
+
+	/*
+	 * If the private flag is set, then the folio 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 (folio_test_private(folio))
+		*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_folio(struct folio *folio)
+{
+	struct inode *inode = folio->mapping->host;
+	int ret;
+
+	dfprintk(PAGECACHE, "NFS: launder_folio(%ld, %llu)\n",
+		inode->i_ino, folio_pos(folio));
+
+	folio_wait_fscache(folio);
+	ret = nfs_wb_folio(inode, folio);
+	trace_nfs_launder_folio_done(inode, folio, ret);
+	return ret;
+}
+
+static int nfs_swap_activate(struct swap_info_struct *sis, struct file *file,
+						sector_t *span)
+{
+	unsigned long blocks;
+	long long isize;
+	int ret;
+	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;
+	}
+
+	ret = rpc_clnt_swap_activate(clnt);
+	if (ret)
+		return ret;
+	ret = add_swap_extent(sis, 0, sis->max, 0);
+	if (ret < 0) {
+		rpc_clnt_swap_deactivate(clnt);
+		return ret;
+	}
+
+	*span = sis->pages;
+
+	if (cl->rpc_ops->enable_swap)
+		cl->rpc_ops->enable_swap(inode);
+
+	sis->flags |= SWP_FS_OPS;
+	return ret;
+}
+
+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 = {
+	.read_folio = nfs_read_folio,
+	.readahead = nfs_readahead,
+	.dirty_folio = filemap_dirty_folio,
+	.writepage = nfs_writepage,
+	.writepages = nfs_writepages,
+	.write_begin = nfs_write_begin,
+	.write_end = nfs_write_end,
+	.invalidate_folio = nfs_invalidate_folio,
+	.release_folio = nfs_release_folio,
+	.migrate_folio = nfs_migrate_folio,
+	.launder_folio = nfs_launder_folio,
+	.is_dirty_writeback = nfs_check_dirty_writeback,
+	.error_remove_page = generic_error_remove_page,
+	.swap_activate = nfs_swap_activate,
+	.swap_deactivate = nfs_swap_deactivate,
+	.swap_rw = nfs_swap_rw,
+};
+
+/*
+ * 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 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;
+	struct folio *folio = page_folio(vmf->page);
+
+	dfprintk(PAGECACHE, "NFS: vm_page_mkwrite(%pD2(%lu), offset %lld)\n",
+		 filp, filp->f_mapping->host->i_ino,
+		 (long long)folio_file_pos(folio));
+
+	sb_start_pagefault(inode->i_sb);
+
+	/* make sure the cache has finished storing the page */
+	if (folio_test_fscache(folio) &&
+	    folio_wait_fscache_killable(folio) < 0) {
+		ret = VM_FAULT_RETRY;
+		goto out;
+	}
+
+	wait_on_bit_action(&NFS_I(inode)->flags, NFS_INO_INVALIDATING,
+			   nfs_wait_bit_killable,
+			   TASK_KILLABLE|TASK_FREEZABLE_UNSAFE);
+
+	folio_lock(folio);
+	mapping = folio_file_mapping(folio);
+	if (mapping != inode->i_mapping)
+		goto out_unlock;
+
+	folio_wait_writeback(folio);
+
+	pagelen = nfs_folio_length(folio);
+	if (pagelen == 0)
+		goto out_unlock;
+
+	ret = VM_FAULT_LOCKED;
+	if (nfs_flush_incompatible(filp, folio) == 0 &&
+	    nfs_update_folio(filp, folio, 0, pagelen) == 0)
+		goto out;
+
+	ret = VM_FAULT_SIGBUS;
+out_unlock:
+	folio_unlock(folio);
+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,
+};
+
+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 int mntflags = NFS_SERVER(inode)->flags;
+	ssize_t result, written;
+	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 || iocb->ki_pos > i_size_read(inode)) {
+		result = nfs_revalidate_file_size(inode, file);
+		if (result)
+			return result;
+	}
+
+	nfs_clear_invalid_mapping(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)
+		result = generic_perform_write(iocb, from);
+	nfs_end_io_write(inode);
+	if (result <= 0)
+		goto out;
+
+	written = result;
+	nfs_add_stats(inode, NFSIOS_NORMALWRITTENBYTES, written);
+
+	if (mntflags & NFS_MOUNT_WRITE_EAGER) {
+		result = filemap_fdatawrite_range(file->f_mapping,
+						  iocb->ki_pos - written,
+						  iocb->ki_pos - 1);
+		if (result < 0)
+			goto out;
+	}
+	if (mntflags & NFS_MOUNT_WRITE_WAIT) {
+		filemap_fdatawait_range(file->f_mapping,
+					iocb->ki_pos - written,
+					iocb->ki_pos - 1);
+	}
+	result = generic_write_sync(iocb, written);
+	if (result < 0)
+		return result;
+
+out:
+	/* Return error values */
+	error = filemap_check_wb_err(file->f_mapping, since);
+	switch (error) {
+	default:
+		break;
+	case -EDQUOT:
+	case -EFBIG:
+	case -ENOSPC:
+		nfs_wb_all(inode);
+		error = file_check_and_advance_wb_err(file);
+		if (error < 0)
+			result = error;
+	}
+	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);
+
+	if (fl->fl_flags & FL_RECLAIM)
+		return -ENOGRACE;
+
+	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;
+
+	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	= nfs_file_splice_read,
+	.splice_write	= iter_file_splice_write,
+	.check_flags	= nfs_check_flags,
+	.setlease	= simple_nosetlease,
+};
+EXPORT_SYMBOL_GPL(nfs_file_operations);