1 files changed, 45 insertions, 4 deletions

diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index 3c2b893665ba..94e94bd11aae 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -292,7 +292,7 @@ static int
 nfs_file_fsync(struct file *file, loff_t start, loff_t end, int datasync)
 {
 	int ret;
-	struct inode *inode = file->f_path.dentry->d_inode;
+	struct inode *inode = file_inode(file);
 
 	do {
 		ret = filemap_write_and_wait_range(inode->i_mapping, start, end);
@@ -451,11 +451,13 @@ static int nfs_write_end(struct file *file, struct address_space *mapping,
  * - 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 long offset)
+static void nfs_invalidate_page(struct page *page, unsigned int offset,
+				unsigned int length)
 {
-	dfprintk(PAGECACHE, "NFS: invalidate_page(%p, %lu)\n", page, offset);
+	dfprintk(PAGECACHE, "NFS: invalidate_page(%p, %u, %u)\n",
+		 page, offset, length);
 
-	if (offset != 0)
+	if (offset != 0 || length < PAGE_CACHE_SIZE)
 		return;
 	/* Cancel any unstarted writes on this page */
 	nfs_wb_page_cancel(page_file_mapping(page)->host, page);
@@ -493,6 +495,35 @@ static int nfs_release_page(struct page *page, gfp_t gfp)
 	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 (test_bit(NFS_INO_COMMIT, &nfsi->flags)) {
+		*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
@@ -540,6 +571,7 @@ const struct address_space_operations nfs_file_aops = {
 	.direct_IO = nfs_direct_IO,
 	.migratepage = nfs_migrate_page,
 	.launder_page = nfs_launder_page,
+	.is_dirty_writeback = nfs_check_dirty_writeback,
 	.error_remove_page = generic_error_remove_page,
 #ifdef CONFIG_NFS_SWAP
 	.swap_activate = nfs_swap_activate,
@@ -744,6 +776,7 @@ 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;
 
 	/*
@@ -752,6 +785,14 @@ do_unlk(struct file *filp, int cmd, struct file_lock *fl, int is_local)
 	 */
 	nfs_sync_mapping(filp->f_mapping);
 
+	l_ctx = nfs_get_lock_context(nfs_file_open_context(filp));
+	if (!IS_ERR(l_ctx)) {
+		status = nfs_iocounter_wait(&l_ctx->io_count);
+		nfs_put_lock_context(l_ctx);
+		if (status < 0)
+			return status;
+	}
+
 	/* NOTE: special case
 	 * 	If we're signalled while cleaning up locks on process exit, we
 	 * 	still need to complete the unlock.