summary refs log tree commit diff
path: root/block
diff options
context:
space:
mode:
authorJeff Moyer <jmoyer@redhat.com>2011-10-17 12:57:22 +0200
committerJens Axboe <axboe@kernel.dk>2011-10-24 16:24:30 +0200
commit834f9f61a525d2f6d3d0c93894e26326c8d3ceed (patch)
tree73e973ad0c01ce4ac0317f089c9cbb3707186834 /block
parent456be1484ffc72a24bdb4200b5847c4fa90139d9 (diff)
downloadlinux-834f9f61a525d2f6d3d0c93894e26326c8d3ceed.tar.gz
blk-flush: fix invalid BUG_ON in blk_insert_flush
A user reported a regression due to commit
4853abaae7e4a2af938115ce9071ef8684fb7af4 (block: fix flush
machinery for stacking drivers with differring flush flags).
Part of the problem is that blk_insert_flush required a
single bio be attached to the request.  In reality, having
no attached bio is also a valid case, as can be observed with
an empty flush.

[1] http://www.redhat.com/archives/dm-devel/2011-September/msg00154.html

Reported-by: Christophe Saout <christophe@saout.de>
Signed-off-by: Jeff Moyer <jmoyer@redhat.com
Acked-by: Tejun Heo <tj@kernel.org>

Stable note: 3.1
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block')
-rw-r--r--block/blk-flush.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/block/blk-flush.c b/block/blk-flush.c
index 491eb30a242d..89ae3b9bf7ca 100644
--- a/block/blk-flush.c
+++ b/block/blk-flush.c
@@ -320,7 +320,7 @@ void blk_insert_flush(struct request *rq)
 		return;
 	}
 
-	BUG_ON(!rq->bio || rq->bio != rq->biotail);
+	BUG_ON(rq->bio != rq->biotail); /*assumes zero or single bio rq */
 
 	/*
 	 * If there's data but flush is not necessary, the request can be