On Sat, 2017-09-30 at 14:12 +0800, Ming Lei wrote: > @@ -1395,16 +1401,21 @@ static struct request *blk_old_get_request(struct request_queue *q, > unsigned int op, gfp_t gfp_mask) > { > struct request *rq; > + int ret = 0; > > WARN_ON_ONCE(q->mq_ops); > > /* create ioc upfront */ > create_io_context(gfp_mask, q->node); > > + ret = blk_queue_enter(q, !(gfp_mask & __GFP_DIRECT_RECLAIM)); > + if (ret) > + return ERR_PTR(ret); Can the above blk_queue_enter() call block if the REQ_NOWAIT flag has been set in the op argument and e.g. gfp_mask == GFP_KERNEL? If so, isn't that a bug? Bart.