blk-mq: move lockdep_assert_held() into elevator_exit

Commit c48dac137a ("block: don't hold q->sysfs_lock in elevator_init_mq")
removes q->sysfs_lock from elevator_init_mq(), but forgot to deal with
lockdep_assert_held() called in blk_mq_sched_free_requests() which is
run in failure path of elevator_init_mq().

blk_mq_sched_free_requests() is called in the following 3 functions:

	elevator_init_mq()
	elevator_exit()
	blk_cleanup_queue()

In blk_cleanup_queue(), blk_mq_sched_free_requests() is followed exactly
by 'mutex_lock(&q->sysfs_lock)'.

So moving the lockdep_assert_held() from blk_mq_sched_free_requests()
into elevator_exit() for fixing the report by syzbot.

Reported-by: [email protected]
Fixed: c48dac137a ("block: don't hold q->sysfs_lock in elevator_init_mq")
Reviewed-by: Bart Van Assche <[email protected]>
Reviewed-by: Damien Le Moal <[email protected]>
Signed-off-by: Ming Lei <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>
This commit is contained in:
Ming Lei 2019-09-26 06:23:54 +08:00 • committed by Jens Axboe
commit 284b94be19
2 changed files with 2 additions and 2 deletions

View file

@ -555,8 +555,6 @@ void blk_mq_sched_free_requests(struct request_queue *q)
struct blk_mq_hw_ctx *hctx;
int i;
lockdep_assert_held(&q->sysfs_lock);
queue_for_each_hw_ctx(q, hctx, i) {
if (hctx->sched_tags)
blk_mq_free_rqs(q->tag_set, hctx->sched_tags, i);

View file

@ -194,6 +194,8 @@ void elv_unregister_queue(struct request_queue *q);
static inline void elevator_exit(struct request_queue *q,
struct elevator_queue *e)
{
lockdep_assert_held(&q->sysfs_lock);
blk_mq_sched_free_requests(q);
__elevator_exit(q, e);
}