NFS: don't use FLUSH_SYNC on WB_SYNC_NONE COMMIT calls (try #2)

WB_SYNC_NONE is supposed to mean "don't wait on anything". That should
also include not waiting for COMMIT calls to complete.

WB_SYNC_NONE is also implied when wbc->nonblocking and
wbc->for_background are set, so we can replace those checks in
nfs_commit_unstable_pages with a check for WB_SYNC_NONE.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 9 insertions, 7 deletions

diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 4d6d35dd2b4b..605e292501f4 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -1431,15 +1431,17 @@ static int nfs_commit_unstable_pages(struct inode *inode, struct writeback_contr
         int flags = FLUSH_SYNC;
         int ret = 0;
 
-        /* Don't commit yet if this is a non-blocking flush and there are
-         * lots of outstanding writes for this mapping.
-         */
-        if (wbc->sync_mode == WB_SYNC_NONE &&
-            nfsi->ncommit <= (nfsi->npages >> 1))
-                goto out_mark_dirty;
+        if (wbc->sync_mode == WB_SYNC_NONE) {
+                /* Don't commit yet if this is a non-blocking flush and there
+                 * are a lot of outstanding writes for this mapping.
+                 */
+                if (nfsi->ncommit <= (nfsi->npages >> 1))
+                        goto out_mark_dirty;
 
-        if (wbc->nonblocking || wbc->for_background)
+                /* don't wait for the COMMIT response */
                 flags = 0;
+        }
+
         ret = nfs_commit_inode(inode, flags);
         if (ret >= 0) {
                 if (wbc->sync_mode == WB_SYNC_NONE) {