NFSv4: Respect the server imposed limit on how many changes we may cache

The NFSv4 delegation spec allows the server to tell a client to limit how
much data it cache after the file is closed. In return, the server
guarantees enough free space to avoid ENOSPC situations, etc.
Prior to this patch, we assumed we could always cache aggressively after
close. Unfortunately, this causes problems with servers that set the
limit to 0 and therefore do not offer any ENOSPC guarantees.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

1 files changed, 1 insertions, 9 deletions

diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index 526a2681d975..c0f9b1ed12b9 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -142,7 +142,7 @@ EXPORT_SYMBOL_GPL(nfs_file_llseek);
 /*
  * Flush all dirty pages, and check for write errors.
  */
-int
+static int
 nfs_file_flush(struct file *file, fl_owner_t id)
 {
         struct inode    *inode = file_inode(file);
@@ -153,17 +153,9 @@ nfs_file_flush(struct file *file, fl_owner_t id)
         if ((file->f_mode & FMODE_WRITE) == 0)
                 return 0;
 
-        /*
-         * If we're holding a write delegation, then just start the i/o
-         * but don't wait for completion (or send a commit).
-         */
-        if (NFS_PROTO(inode)->have_delegation(inode, FMODE_WRITE))
-                return filemap_fdatawrite(file->f_mapping);
-
         /* Flush writes to the server and return any errors */
         return vfs_fsync(file, 0);
 }
-EXPORT_SYMBOL_GPL(nfs_file_flush);
 
 ssize_t
 nfs_file_read(struct kiocb *iocb, struct iov_iter *to)