This is a note to let you know that I've just added the patch titled block: mark blk_put_queue as potentially blocking to the 6.1-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: block-mark-blk_put_queue-as-potentially-blocking.patch and it can be found in the queue-6.1 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 1ec7de36d3a9c53347ce5a07ffdfabc14ebed66b Author: Christoph Hellwig <hch@xxxxxx> Date: Mon Nov 14 05:26:37 2022 +0100 block: mark blk_put_queue as potentially blocking [ Upstream commit 63f93fd6fa5717769a78d6d7bea6f7f9a1ccca8e ] We can't just say that the last reference release may block, as any reference dropped could be the last one. So move the might_sleep() from blk_free_queue to blk_put_queue and update the documentation. Signed-off-by: Christoph Hellwig <hch@xxxxxx> Link: https://lore.kernel.org/r/20221114042637.1009333-6-hch@xxxxxx Signed-off-by: Jens Axboe <axboe@xxxxxxxxx> Stable-dep-of: 49e4d04f0486 ("block: Drop spurious might_sleep() from blk_put_queue()") Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/block/blk-core.c b/block/blk-core.c index 7de1bb16e9a7..815ffce6b988 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -260,8 +260,6 @@ static void blk_free_queue_rcu(struct rcu_head *rcu_head) static void blk_free_queue(struct request_queue *q) { - might_sleep(); - percpu_ref_exit(&q->q_usage_counter); if (q->poll_stat) @@ -285,11 +283,11 @@ 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: Any context, but the last reference must not be dropped from - * atomic context. + * Context: Can sleep. */ void blk_put_queue(struct request_queue *q) { + might_sleep(); if (refcount_dec_and_test(&q->refs)) blk_free_queue(q); }