NFS: Fix up O_DIRECT results

if we read or wrote something, we must report it

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Reviewed-by: Jeff Layton <jlayton@poochiereds.net>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

1 files changed, 7 insertions, 3 deletions

diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index 979b3c4dee6a..c7326c2af2c3 100644
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -353,10 +353,12 @@ static ssize_t nfs_direct_wait(struct nfs_direct_req *dreq)
 
         result = wait_for_completion_killable(&dreq->completion);
 
+        if (!result) {
+                result = dreq->count;
+                WARN_ON_ONCE(dreq->count < 0);
+        }
         if (!result)
                 result = dreq->error;
-        if (!result)
-                result = dreq->count;
 
 out:
         return (ssize_t) result;
@@ -386,8 +388,10 @@ static void nfs_direct_complete(struct nfs_direct_req *dreq, bool write)
 
         if (dreq->iocb) {
                 long res = (long) dreq->error;
-                if (!res)
+                if (dreq->count != 0) {
                         res = (long) dreq->count;
+                        WARN_ON_ONCE(dreq->count < 0);
+                }
                 dreq->iocb->ki_complete(dreq->iocb, res, 0);
         }