From 50cd19175b068538c21f6c627242b60204f106f0 Mon Sep 17 00:00:00 2001
From: Stefan Bader <shbader@de.ibm.com>
Date: Thu, 12 Jul 2007 17:28:33 +0100
Subject: [PATCH] --- yaml --- r: 59286 b: refs/heads/master c:
 07a83c47cfc00ba5f0f090ccddd3a0703be0eec9 h: refs/heads/master v: v3

---
 [refs]                      | 2 +-
 trunk/drivers/md/dm-crypt.c | 3 ---
 trunk/drivers/md/dm-mpath.c | 3 ---
 trunk/drivers/md/dm-snap.c  | 6 ------
 trunk/drivers/md/dm.c       | 9 +++++++++
 5 files changed, 10 insertions(+), 13 deletions(-)

diff --git a/[refs] b/[refs]
index 2bb5d663bc35..6c8e5515cbce 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 943317efdbc295e8a28df3f5cbd549d066ee8b4a
+refs/heads/master: 07a83c47cfc00ba5f0f090ccddd3a0703be0eec9
diff --git a/trunk/drivers/md/dm-crypt.c b/trunk/drivers/md/dm-crypt.c
index ece7c7c4cdbb..ba952a032598 100644
--- a/trunk/drivers/md/dm-crypt.c
+++ b/trunk/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/trunk/drivers/md/dm-mpath.c b/trunk/drivers/md/dm-mpath.c
index fc6c1021178d..d6ca9d0a6fd1 100644
--- a/trunk/drivers/md/dm-mpath.c
+++ b/trunk/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/trunk/drivers/md/dm-snap.c b/trunk/drivers/md/dm-snap.c
index 854891d07b59..83ddbfe6b8a4 100644
--- a/trunk/drivers/md/dm-snap.c
+++ b/trunk/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/trunk/drivers/md/dm.c b/trunk/drivers/md/dm.c
index b5e56af8f85a..f4f7d35561ab 100644
--- a/trunk/drivers/md/dm.c
+++ b/trunk/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]);