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>

diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index 979b3c4..c7326c2 100644 (file)
--- 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);
        }