This is a note to let you know that I've just added the patch titled blk-cgroup: fix missing put device in error path from blkg_conf_pref() to the 5.15-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: blk-cgroup-fix-missing-put-device-in-error-path-from.patch and it can be found in the queue-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit dab36e7feab2921e41915fb27f6490f0838af56f Author: Yu Kuai <yukuai3@xxxxxxxxxx> Date: Tue Nov 2 10:07:05 2021 +0800 blk-cgroup: fix missing put device in error path from blkg_conf_pref() [ Upstream commit 15c30104965101b8e76b24d27035569d6613a7d6 ] If blk_queue_enter() failed due to queue is dying, the blkdev_put_no_open() is needed because blkcg_conf_open_bdev() succeeded. Fixes: 0c9d338c8443 ("blk-cgroup: synchronize blkg creation against policy deactivation") Signed-off-by: Yu Kuai <yukuai3@xxxxxxxxxx> Acked-by: Tejun Heo <tj@xxxxxxxxxx> Link: https://lore.kernel.org/r/20211102020705.2321858-1-yukuai3@xxxxxxxxxx Signed-off-by: Jens Axboe <axboe@xxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index ebff1af402e5b..0eec59e4df65c 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -639,7 +639,7 @@ int blkg_conf_prep(struct blkcg *blkcg, const struct blkcg_policy *pol, */ ret = blk_queue_enter(q, 0); if (ret) - return ret; + goto fail; rcu_read_lock(); spin_lock_irq(&q->queue_lock); @@ -675,13 +675,13 @@ int blkg_conf_prep(struct blkcg *blkcg, const struct blkcg_policy *pol, new_blkg = blkg_alloc(pos, q, GFP_KERNEL); if (unlikely(!new_blkg)) { ret = -ENOMEM; - goto fail; + goto fail_exit_queue; } if (radix_tree_preload(GFP_KERNEL)) { blkg_free(new_blkg); ret = -ENOMEM; - goto fail; + goto fail_exit_queue; } rcu_read_lock(); @@ -721,9 +721,10 @@ int blkg_conf_prep(struct blkcg *blkcg, const struct blkcg_policy *pol, fail_unlock: spin_unlock_irq(&q->queue_lock); rcu_read_unlock(); +fail_exit_queue: + blk_queue_exit(q); fail: blkdev_put_no_open(bdev); - blk_queue_exit(q); /* * If queue was bypassing, we should retry. Do so after a * short msleep(). It isn't strictly necessary but queue