From: Christoph Hellwig <hch@lst.de>
Date: Thu, 13 Apr 2023 06:40:38 +0000 (+0200)
Subject: blk-mq: don't plug for head insertions in blk_execute_rq_nowait
X-Git-Tag: v6.2.15~299
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=2be23ebc92077f9a22e8d0f07d6bfd6dff7ae636;p=thirdparty%2Fkernel%2Fstable.git

blk-mq: don't plug for head insertions in blk_execute_rq_nowait

[ Upstream commit 50947d7fe9fa6abe3ddc40769dfb02a51c58edb6 ]

Plugs never insert at head, so don't plug for head insertions.

Fixes: 1c2d2fff6dc0 ("block: wire-up support for passthrough plugging")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20230413064057.707578-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/block/blk-mq.c b/block/blk-mq.c
index 22d739cf8d326..9f1bafb62973d 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -1345,7 +1345,7 @@ void blk_execute_rq_nowait(struct request *rq, bool at_head)
 	 * device, directly accessing the plug instead of using blk_mq_plug()
 	 * should not have any consequences.
 	 */
-	if (current->plug)
+	if (current->plug && !at_head)
 		blk_add_rq_to_plug(current->plug, rq);
 	else
 		blk_mq_sched_insert_request(rq, at_head, true, false);