On 9/26/19 12:23 AM, Ming Lei wrote:
> Commit c48dac137a62 ("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.
Applied, thanks Ming.
--
Jens Axboe
