From 834f9f61a525d2f6d3d0c93894e26326c8d3ceed Mon Sep 17 00:00:00 2001 From: Jeff Moyer Date: Mon, 17 Oct 2011 12:57:22 +0200 Subject: [PATCH] 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 Signed-off-by: Jeff Moyer Stable note: 3.1 Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe --- block/blk-flush.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) 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 -- 2.34.1