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 b3ebf60..1ab41fb 100644 (file)
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -1313,7 +1313,7 @@ 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);