[PATCH 5.2 105/143] NFS: Ensure O_DIRECT reports an error if the bytes read/written is 0

[Greg Kroah-Hartman]

From: Trond Myklebust <trond.mykleb...@hammerspace.com>

commit eb2c50da9e256dbbb3ff27694440e4c1900cfef8 upstream.

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.mykleb...@hammerspace.com>
Fixes: 0a00b77b331a ("nfs: mirroring support for direct io")
Cc: sta...@vger.kernel.org # v3.20+
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>

---
 fs/nfs/direct.c   |   27 ++++++++++++++++++---------
 fs/nfs/pagelist.c |    1 +
 2 files changed, 19 insertions(+), 9 deletions(-)

--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -401,15 +401,21 @@ static void nfs_direct_read_completion(s
        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(
        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)
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -1268,6 +1268,7 @@ int nfs_pageio_resend(struct nfs_pageio_
        if (!list_empty(&pages)) {
                int err = desc->pg_error < 0 ? desc->pg_error : -EIO;
                hdr->completion_ops->error_cleanup(&pages, err);
+               nfs_set_pgio_error(hdr, err, hdr->io_start);
                return err;
        }
        return 0;