blk-mq: open code __blk_mq_alloc_request in blk_mq_alloc_request_hctx (600c3b0c) · Commits · 戴 / test

block/blk-mq.c

+23 −21

Original line number	Diff line number	Diff line
		@@ -351,21 +351,13 @@ static struct request __blk_mq_alloc_request(struct blk_mq_alloc_data data)
		{
		struct request_queue *q = data->q;
		struct elevator_queue *e = q->elevator;
		unsigned int tag;
		bool clear_ctx_on_error = false;
		u64 alloc_time_ns = 0;
		unsigned int tag;

		/* alloc_time includes depth and tag waits */
		if (blk_queue_rq_alloc_time(q))
		alloc_time_ns = ktime_get_ns();

		if (likely(!data->ctx)) {
		data->ctx = blk_mq_get_ctx(q);
		clear_ctx_on_error = true;
		}
		if (likely(!data->hctx))
		data->hctx = blk_mq_map_queue(q, data->cmd_flags,
		data->ctx);
		if (data->cmd_flags & REQ_NOWAIT)
		data->flags \|= BLK_MQ_REQ_NOWAIT;

		@@ -381,17 +373,16 @@ static struct request __blk_mq_alloc_request(struct blk_mq_alloc_data data)
		e->type->ops.limit_depth &&
		!(data->flags & BLK_MQ_REQ_RESERVED))
		e->type->ops.limit_depth(data->cmd_flags, data);
		} else {
		blk_mq_tag_busy(data->hctx);
		}

		data->ctx = blk_mq_get_ctx(q);
		data->hctx = blk_mq_map_queue(q, data->cmd_flags, data->ctx);
		if (!(data->flags & BLK_MQ_REQ_INTERNAL))
		blk_mq_tag_busy(data->hctx);

		tag = blk_mq_get_tag(data);
		if (tag == BLK_MQ_NO_TAG) {
		if (clear_ctx_on_error)
		data->ctx = NULL;
		if (tag == BLK_MQ_NO_TAG)
		return NULL;
		}

		return blk_mq_rq_ctx_init(data, tag, alloc_time_ns);
		}

		@@ -431,17 +422,22 @@ struct request blk_mq_alloc_request_hctx(struct request_queue q,
		.flags = flags,
		.cmd_flags = op,
		};
		struct request *rq;
		u64 alloc_time_ns = 0;
		unsigned int cpu;
		unsigned int tag;
		int ret;

		/* alloc_time includes depth and tag waits */
		if (blk_queue_rq_alloc_time(q))
		alloc_time_ns = ktime_get_ns();

		/*
		* If the tag allocator sleeps we could get an allocation for a
		* different hardware context. No need to complicate the low level
		* allocator for this for the rare use case of a command tied to
		* a specific queue.
		*/
		if (WARN_ON_ONCE(!(flags & BLK_MQ_REQ_NOWAIT)))
		if (WARN_ON_ONCE(!(flags & (BLK_MQ_REQ_NOWAIT \| BLK_MQ_REQ_RESERVED))))
		return ERR_PTR(-EINVAL);

		if (hctx_idx >= q->nr_hw_queues)
		@@ -462,11 +458,17 @@ struct request blk_mq_alloc_request_hctx(struct request_queue q,
		cpu = cpumask_first_and(data.hctx->cpumask, cpu_online_mask);
		data.ctx = __blk_mq_get_ctx(q, cpu);

		if (q->elevator)
		data.flags \|= BLK_MQ_REQ_INTERNAL;
		else
		blk_mq_tag_busy(data.hctx);

		ret = -EWOULDBLOCK;
		rq = __blk_mq_alloc_request(&data);
		if (!rq)
		tag = blk_mq_get_tag(&data);
		if (tag == BLK_MQ_NO_TAG)
		goto out_queue_exit;
		return rq;
		return blk_mq_rq_ctx_init(&data, tag, alloc_time_ns);

		out_queue_exit:
		blk_queue_exit(q);
		return ERR_PTR(ret);

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