[PATCH V3 1/4] blk-mq: serialize queue quiesce and unquiesce by mutex

[Bart Van Assche]

On 2020-09-08 01:15, Ming Lei wrote:
>  void blk_mq_unquiesce_queue(struct request_queue *q)
>  {
> +	mutex_lock(&q->mq_quiesce_lock);
> +
>  	blk_queue_flag_clear(QUEUE_FLAG_QUIESCED, q);
>  
>  	/* dispatch requests which are inserted during quiescing */
>  	blk_mq_run_hw_queues(q, true);
> +
> +	mutex_unlock(&q->mq_quiesce_lock);
>  }
Has the sunvdc driver been retested? It calls blk_mq_unquiesce_queue()
with a spinlock held. As you know calling mutex_lock() while holding a
spinlock is not allowed.

There may be other drivers than the sunvdc driver that do this.

Thanks,

Bart.