[PATCH] device-mapper multipath: Barriers not supported

dm multipath will report barriers as not supported with this patch.

Signed-off-by: Lars Marowsky-Bree <lmb@suse.de>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 6 insertions, 0 deletions

diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index 0c1b8520ef86..84cdb700a247 100644
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -765,6 +765,9 @@ static int multipath_map(struct dm_target *ti, struct bio *bio,
         struct mpath_io *mpio;
         struct multipath *m = (struct multipath *) ti->private;
 
+        if (bio_barrier(bio))
+                return -EOPNOTSUPP;
+
         mpio = mempool_alloc(m->mpio_pool, GFP_NOIO);
         dm_bio_record(&mpio->details, bio);
 
@@ -988,6 +991,9 @@ static int do_end_io(struct multipath *m, struct bio *bio,
         if ((error == -EWOULDBLOCK) && bio_rw_ahead(bio))
                 return error;
 
+        if (error == -EOPNOTSUPP)
+                return error;
+
         spin_lock(&m->lock);
         if (!m->nr_valid_paths) {
                 if (!m->queue_if_no_path || m->suspended) {