Commit 02ba8893 authored Mar 28, 2017 by Omar Sandoval Committed by Jens Axboe Mar 29, 2017

block: fix leak of q->rq_wb



CONFIG_DEBUG_TEST_DRIVER_REMOVE found a possible leak of q->rq_wb when a
request queue is reregistered. This has been a problem since wbt was
introduced, but the WARN_ON(!list_empty(&stats->callbacks)) in the
blk-stat rework exposed it. Fix it by cleaning up wbt when we unregister
the queue.

Fixes: 87760e5e ("block: hook up writeback throttling")
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

parent 0c9539a4

block/blk-sysfs.c

+3 −1

Original line number	Diff line number	Diff line
		@@ -795,7 +795,6 @@ static void blk_release_queue(struct kobject *kobj)
		struct request_queue *q =
		container_of(kobj, struct request_queue, kobj);

		wbt_exit(q);
		if (test_bit(QUEUE_FLAG_POLL_STATS, &q->queue_flags))
		blk_stat_remove_callback(q, q->poll_cb);
		blk_stat_free_callback(q->poll_cb);
		@@ -938,6 +937,9 @@ void blk_unregister_queue(struct gendisk *disk)

		queue_flag_clear_unlocked(QUEUE_FLAG_REGISTERED, q);

		wbt_exit(q);


		if (q->mq_ops)
		blk_mq_unregister_dev(disk_to_dev(disk), q);

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