Commit 15c30104 authored by Yu Kuai's avatar Yu Kuai Committed by Jens Axboe
Browse files

blk-cgroup: fix missing put device in error path from blkg_conf_pref() 



If blk_queue_enter() failed due to queue is dying, the
blkdev_put_no_open() is needed because blkcg_conf_open_bdev() succeeded.

Fixes: 0c9d338c ("blk-cgroup: synchronize blkg creation against policy deactivation")
Signed-off-by: default avatarYu Kuai <yukuai3@huawei.com>
Acked-by: default avatarTejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20211102020705.2321858-1-yukuai3@huawei.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 245a489e

block/blk-cgroup.c

+5 −4
Original line number Diff line number Diff line
@@ -640,7 +640,7 @@ 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);
@@ -676,13 +676,13 @@ 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();
@@ -722,9 +722,10 @@ 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