dm: disable barriers

This patch causes device-mapper to reject any barrier requests.  This is done
since most of the targets won't handle this correctly anyway.  So until the
situation improves it is better to reject these requests at the first place.
Since barrier requests won't get to the targets, the checks there can be
removed.

Cc: stable@kernel.org
Signed-off-by: Stefan Bader <shbader@de.ibm.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 0 insertions, 3 deletions

diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index ece7c7c4cdbb..ba952a032598 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -941,9 +941,6 @@ static int crypt_map(struct dm_target *ti, struct bio *bio,
         struct crypt_config *cc = ti->private;
         struct dm_crypt_io *io;
 
-        if (bio_barrier(bio))
-                return -EOPNOTSUPP;
-
         io = mempool_alloc(cc->io_pool, GFP_NOIO);
         io->target = ti;
         io->base_bio = bio;