xfs: don't allow DAX on reflink filesystems

Now that reflink is no longer experimental, reject attempts to mount
with DAX until that whole mess gets sorted out.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Bill O'Donnell <billodo@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

1 files changed, 4 insertions, 1 deletions

diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index f3e0001f9992..0505605e25c1 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -1666,9 +1666,12 @@ xfs_fs_fill_super(
                         "DAX unsupported by block device. Turning off DAX.");
                         mp->m_flags &= ~XFS_MOUNT_DAX;
                 }
-                if (xfs_sb_version_hasreflink(&mp->m_sb))
+                if (xfs_sb_version_hasreflink(&mp->m_sb)) {
                         xfs_alert(mp,
                 "DAX and reflink cannot be used together!");
+                        error = -EINVAL;
+                        goto out_filestream_unmount;
+                }
         }
 
         if (mp->m_flags & XFS_MOUNT_DISCARD) {