From: Milan Broz <mbroz@redhat.com>

Disable barriers in dm-crypt because of current workqueue processing can
reorder requests.

This must be addresed later but for now disabling barriers is needed to
prevent data corruption.

Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 drivers/md/dm-crypt.c |    3 +++
 1 files changed, 3 insertions(+)

diff -puN drivers/md/dm-crypt.c~dm-crypt-disable-barriers drivers/md/dm-crypt.c
--- a/drivers/md/dm-crypt.c~dm-crypt-disable-barriers
+++ a/drivers/md/dm-crypt.c
@@ -954,6 +954,9 @@ static int crypt_map(struct dm_target *t
 	struct crypt_config *cc = ti->private;
 	struct crypt_io *io;
 
+	if (bio_barrier(bio))
+		return -EOPNOTSUPP;
+
 	io = mempool_alloc(cc->io_pool, GFP_NOIO);
 	io->target = ti;
 	io->base_bio = bio;
_