From 9c89f8be1a7d14aad9d2c3f7d90d7d88f82c61e2 Mon Sep 17 00:00:00 2001
From: Milan Broz <mbroz@redhat.com>
Date: Wed, 9 May 2007 02:32:51 -0700
Subject: [PATCH] dm crypt: disable barriers

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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 drivers/md/dm-crypt.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index d8121234c347..8527827b24f1 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -954,6 +954,9 @@ static int crypt_map(struct dm_target *ti, struct bio *bio,
 	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;