From: Tejun Heo tj@kernel.org
[ Upstream commit 49e4d04f0486117ac57a97890eb1db6d52bf82b3 ]
Dan reports the following smatch detected the following:
block/blk-cgroup.c:1863 blkcg_schedule_throttle() warn: sleeping in atomic context
caused by blkcg_schedule_throttle() calling blk_put_queue() in an non-sleepable context.
blk_put_queue() acquired might_sleep() in 63f93fd6fa57 ("block: mark blk_put_queue as potentially blocking") which transferred the might_sleep() from blk_free_queue().
blk_free_queue() acquired might_sleep() in e8c7d14ac6c3 ("block: revert back to synchronous request_queue removal") while turning request_queue removal synchronous. However, this isn't necessary as nothing in the free path actually requires sleeping.
It's pretty unusual to require a sleeping context in a put operation and it's not needed in the first place. Let's drop it.
Signed-off-by: Tejun Heo tj@kernel.org Reported-by: Dan Carpenter error27@gmail.com Link: https://lkml.kernel.org/r/Y7g3L6fntnTtOm63@kili Cc: Christoph Hellwig hch@lst.de Cc: Luis Chamberlain mcgrof@kernel.org Fixes: e8c7d14ac6c3 ("block: revert back to synchronous request_queue removal") # v5.9+ Reviewed-by: Christoph Hellwig hch@lst.de Link: https://lore.kernel.org/r/Y7iFwjN+XzWvLv3y@slm.duckdns.org Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Sasha Levin sashal@kernel.org --- block/blk-core.c | 3 --- 1 file changed, 3 deletions(-)
diff --git a/block/blk-core.c b/block/blk-core.c index 815ffce6b988..f5ae527fb0c3 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -282,12 +282,9 @@ static void blk_free_queue(struct request_queue *q) * * Decrements the refcount of the request_queue and free it when the refcount * reaches 0. - * - * Context: Can sleep. */ void blk_put_queue(struct request_queue *q) { - might_sleep(); if (refcount_dec_and_test(&q->refs)) blk_free_queue(q); }