On 8/3/21 1:06 AM, Ming Lei wrote: > blkcg->lock depends on q->queue_lock which may depend on another driver > lock required in irq context, one example is dm-thin: > > Chain exists of: > &pool->lock#3 --> &q->queue_lock --> &blkcg->lock > > Possible interrupt unsafe locking scenario: > > CPU0 CPU1 > ---- ---- > lock(&blkcg->lock); > local_irq_disable(); > lock(&pool->lock#3); > lock(&q->queue_lock); > <Interrupt> > lock(&pool->lock#3); > > Fix the issue by using spin_lock_irq(&blkcg->lock) in ioc_weight_write(). Applied, thanks. -- Jens Axboe
