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>

diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 4d6d35dd2b4babc5f252e87e5d17e712de8f3738..605e292501f493cbf921c8ee0a4b22caf863572c 100644 (file)
--- 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) {