[PATCH] md: fail IO request to md that require a barrier.

md does not yet support BIO_RW_BARRIER, so be honest about it and fail
(-EOPNOTSUPP) any such requests.

Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 4 insertions, 0 deletions

diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index 51d9645ed09c..ace41c571aeb 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -555,6 +555,10 @@ static int make_request(request_queue_t *q, struct bio * bio)
         unsigned long flags;
         struct bio_list bl;
 
+        if (unlikely(bio_barrier(bio))) {
+                bio_endio(bio, bio->bi_size, -EOPNOTSUPP);
+                return 0;
+        }
 
         /*
          * Register the new request and wait if the reconstruction