NFS: Ensure O_DIRECT reports an error if the bytes read/written is 0

If the attempt to resend the I/O results in no bytes being read/written,
we must ensure that we report the error.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Fixes: 0a00b77b331a ("nfs: mirroring support for direct io")
Cc: stable@vger.kernel.org # v3.20+

1 files changed, 18 insertions, 9 deletions

diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index 0cb442406168..222d7115db71 100644
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -401,15 +401,21 @@ static void nfs_direct_read_completion(struct nfs_pgio_header *hdr)
         unsigned long bytes = 0;
         struct nfs_direct_req *dreq = hdr->dreq;
 
-        if (test_bit(NFS_IOHDR_REDO, &hdr->flags))
-                goto out_put;
-
         spin_lock(&dreq->lock);
-        if (test_bit(NFS_IOHDR_ERROR, &hdr->flags) && (hdr->good_bytes == 0))
+        if (test_bit(NFS_IOHDR_ERROR, &hdr->flags))
                 dreq->error = hdr->error;
-        else
+
+        if (test_bit(NFS_IOHDR_REDO, &hdr->flags)) {
+                spin_unlock(&dreq->lock);
+                goto out_put;
+        }
+
+        if (hdr->good_bytes != 0)
                 nfs_direct_good_bytes(dreq, hdr);
 
+        if (test_bit(NFS_IOHDR_EOF, &hdr->flags))
+                dreq->error = 0;
+
         spin_unlock(&dreq->lock);
 
         while (!list_empty(&hdr->pages)) {
@@ -782,16 +788,19 @@ static void nfs_direct_write_completion(struct nfs_pgio_header *hdr)
         bool request_commit = false;
         struct nfs_page *req = nfs_list_entry(hdr->pages.next);
 
-        if (test_bit(NFS_IOHDR_REDO, &hdr->flags))
-                goto out_put;
-
         nfs_init_cinfo_from_dreq(&cinfo, dreq);
 
         spin_lock(&dreq->lock);
 
         if (test_bit(NFS_IOHDR_ERROR, &hdr->flags))
                 dreq->error = hdr->error;
-        if (dreq->error == 0) {
+
+        if (test_bit(NFS_IOHDR_REDO, &hdr->flags)) {
+                spin_unlock(&dreq->lock);
+                goto out_put;
+        }
+
+        if (hdr->good_bytes != 0) {
                 nfs_direct_good_bytes(dreq, hdr);
                 if (nfs_write_need_commit(hdr)) {
                         if (dreq->flags == NFS_ODIRECT_RESCHED_WRITES)