blk-mq: blk_mq_try_issue_directly() should lookup hardware queue (066a4a73) · Commits · 戴 / test

A previous commit changed this to pass in the hardware queue, but it was using the wrong hardware queue. Hence a request that was allocated on one hardware queue ended up being issued on another one, and that caused IO timeouts and oopses on some drivers. Since the request holds hardware queue private resources, like a tag, we can't just issue it on a different hardware queue. Fixes: ("blk-mq: Move more code into blk_mq_direct_issue_request()") Signed-off-by:

Jens Axboe <axboe@fb.com>

block/blk-mq.c

+4 −4

Original line number	Diff line number	Diff line
		@@ -1291,11 +1291,11 @@ static struct request blk_mq_map_request(struct request_queue q,
		return rq;
		}

		static void blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx,
		struct request rq, blk_qc_t cookie)
		static void blk_mq_try_issue_directly(struct request rq, blk_qc_t cookie)
		{
		int ret;
		struct request_queue *q = rq->q;
		struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(q, rq->mq_ctx->cpu);
		struct blk_mq_queue_data bd = {
		.rq = rq,
		.list = NULL,
		@@ -1414,11 +1414,11 @@ static blk_qc_t blk_mq_make_request(struct request_queue q, struct bio bio)

		if (!(data.hctx->flags & BLK_MQ_F_BLOCKING)) {
		rcu_read_lock();
		blk_mq_try_issue_directly(data.hctx, old_rq, &cookie);
		blk_mq_try_issue_directly(old_rq, &cookie);
		rcu_read_unlock();
		} else {
		srcu_idx = srcu_read_lock(&data.hctx->queue_rq_srcu);
		blk_mq_try_issue_directly(data.hctx, old_rq, &cookie);
		blk_mq_try_issue_directly(old_rq, &cookie);
		srcu_read_unlock(&data.hctx->queue_rq_srcu, srcu_idx);
		}
		goto done;

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