Commit 518d00b7 authored Dec 26, 2013 by Ming Lei Committed by Linus Torvalds Jan 12, 2014

block: null_blk: fix queue leak inside removing device



When queue_mode is NULL_Q_MQ and null_blk is being removed,
blk_cleanup_queue() isn't called to cleanup queue, so the queue
allocated won't be freed.

This patch calls blk_cleanup_queue() for MQ to drain all pending
requests first and release the reference counter of queue kobject, then
blk_mq_free_queue() will be called in queue kobject's release handler
when queue kobject's reference counter drops to zero.

Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 228fdc08

drivers/block/null_blk.c

+2 −8

Original line number	Diff line number	Diff line
		@@ -425,9 +425,6 @@ static void null_del_dev(struct nullb *nullb)
		list_del_init(&nullb->list);

		del_gendisk(nullb->disk);
		if (queue_mode == NULL_Q_MQ)
		blk_mq_free_queue(nullb->q);
		else
		blk_cleanup_queue(nullb->q);
		put_disk(nullb->disk);
		kfree(nullb);
		@@ -578,9 +575,6 @@ static int null_add_dev(void)
		disk = nullb->disk = alloc_disk_node(1, home_node);
		if (!disk) {
		queue_fail:
		if (queue_mode == NULL_Q_MQ)
		blk_mq_free_queue(nullb->q);
		else
		blk_cleanup_queue(nullb->q);
		cleanup_queues(nullb);
		err:

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