From c8712c6a674e3382fe4d26d108251ccfa55d08e0 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 23 Sep 2016 10:25:48 -0600 Subject: [PATCH] blk-mq: skip unmapped queues in blk_mq_alloc_request_hctx This provides the caller a feedback that a given hctx is not mapped and thus no command can be sent on it. Signed-off-by: Christoph Hellwig Tested-by: Steve Wise Signed-off-by: Jens Axboe --- block/blk-mq.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) diff --git a/block/blk-mq.c b/block/blk-mq.c index 13f5a6c1de76..c207fa9870eb 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -296,17 +296,29 @@ struct request *blk_mq_alloc_request_hctx(struct request_queue *q, int rw, if (ret) return ERR_PTR(ret); + /* + * Check if the hardware context is actually mapped to anything. + * If not tell the caller that it should skip this queue. + */ hctx = q->queue_hw_ctx[hctx_idx]; + if (!blk_mq_hw_queue_mapped(hctx)) { + ret = -EXDEV; + goto out_queue_exit; + } ctx = __blk_mq_get_ctx(q, cpumask_first(hctx->cpumask)); blk_mq_set_alloc_data(&alloc_data, q, flags, ctx, hctx); rq = __blk_mq_alloc_request(&alloc_data, rw, 0); if (!rq) { - blk_queue_exit(q); - return ERR_PTR(-EWOULDBLOCK); + ret = -EWOULDBLOCK; + goto out_queue_exit; } return rq; + +out_queue_exit: + blk_queue_exit(q); + return ERR_PTR(ret); } EXPORT_SYMBOL_GPL(blk_mq_alloc_request_hctx); -- 2.20.1