[dm-devel] [2.6.22 PATCH 03/26] dm crypt: disable barriers

[Alasdair G Kergon <agk redhat com>]

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>
---

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

Index: linux-2.6.21/drivers/md/dm-crypt.c
===================================================================
--- linux-2.6.21.orig/drivers/md/dm-crypt.c	2007-05-01 17:38:32.000000000 +0100
+++ linux-2.6.21/drivers/md/dm-crypt.c	2007-05-01 17:40:47.000000000 +0100
@@ -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;