dm mpath: support barriers

Flush support for dm-multipath target.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index 92bdcbb7c935..f1cf8f7449d6 100644
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -835,6 +835,8 @@ static int multipath_ctr(struct dm_target *ti, unsigned int argc,
                 goto bad;
         }
 
+        ti->num_flush_requests = 1;
+
         return 0;
 
  bad: