NFS: Ensure we return zero if applications attempt to write zero bytes
A zero byte count direct write request should be a successful no-op, not an
error.
Signed-off-by: Chuck Lever <cel@netapp.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index 88d5d1c..4d726e9 100644
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -890,6 +890,8 @@
retval = generic_write_checks(file, &pos, &count, 0);
if (retval)
goto out;
+ if (!count)
+ goto out; /* return 0 */
retval = -EINVAL;
if ((ssize_t) count < 0)