diff options
| author | Stefan Bader <shbader@de.ibm.com> | 2007-07-12 17:28:33 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-07-12 15:01:08 -0700 |
| commit | 07a83c47cfc00ba5f0f090ccddd3a0703be0eec9 (patch) | |
| tree | a17d8028f76ba242a04f3c0678644f93cc7eee7d /drivers/md/dm.c | |
| parent | 943317efdbc295e8a28df3f5cbd549d066ee8b4a (diff) | |
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>
Diffstat (limited to 'drivers/md/dm.c')
| -rw-r--r-- | drivers/md/dm.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/drivers/md/dm.c b/drivers/md/dm.c index b5e56af8f85a..f4f7d35561ab 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -800,6 +800,15 @@ static int dm_request(request_queue_t *q, struct bio *bio) int rw = bio_data_dir(bio); struct mapped_device *md = q->queuedata; + /* + * There is no use in forwarding any barrier request since we can't + * guarantee it is (or can be) handled by the targets correctly. + */ + if (unlikely(bio_barrier(bio))) { + bio_endio(bio, bio->bi_size, -EOPNOTSUPP); + return 0; + } + down_read(&md->io_lock); disk_stat_inc(dm_disk(md), ios[rw]); |