From: Stefan Bader Date: Thu, 12 Jul 2007 16:28:33 +0000 (+0100) Subject: dm: disable barriers X-Git-Tag: v2.6.23-rc1~1091 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=07a83c47cfc00ba5f0f090ccddd3a0703be0eec9;p=linux-2.6 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 Signed-off-by: Alasdair G Kergon Signed-off-by: Linus Torvalds --- diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c index ece7c7c4cd..ba952a0325 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; diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c index fc6c102117..d6ca9d0a6f 100644 --- a/drivers/md/dm-mpath.c +++ b/drivers/md/dm-mpath.c @@ -798,9 +798,6 @@ static int multipath_map(struct dm_target *ti, struct bio *bio, struct dm_mpath_io *mpio; struct multipath *m = (struct multipath *) ti->private; - if (bio_barrier(bio)) - return -EOPNOTSUPP; - mpio = mempool_alloc(m->mpio_pool, GFP_NOIO); dm_bio_record(&mpio->details, bio); diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c index 854891d07b..83ddbfe6b8 100644 --- a/drivers/md/dm-snap.c +++ b/drivers/md/dm-snap.c @@ -889,9 +889,6 @@ static int snapshot_map(struct dm_target *ti, struct bio *bio, if (!s->valid) return -EIO; - if (unlikely(bio_barrier(bio))) - return -EOPNOTSUPP; - /* FIXME: should only take write lock if we need * to copy an exception */ down_write(&s->lock); @@ -1162,9 +1159,6 @@ static int origin_map(struct dm_target *ti, struct bio *bio, struct dm_dev *dev = ti->private; bio->bi_bdev = dev->bdev; - if (unlikely(bio_barrier(bio))) - return -EOPNOTSUPP; - /* Only tell snapshots if this is a write */ return (bio_rw(bio) == WRITE) ? do_origin(dev, bio) : DM_MAPIO_REMAPPED; } diff --git a/drivers/md/dm.c b/drivers/md/dm.c index b5e56af8f8..f4f7d35561 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]);