[PATCH 1/8] blk-mq: add blk_mq_alloc_request_hctx
From: Christoph Hellwig <hch@lst.de>
Date: 2016-06-06 21:22:12
Also in:
linux-nvme, lkml
Subsystem:
block layer, the rest · Maintainers:
Jens Axboe, Linus Torvalds
From: Ming Lin <redacted> For some protocols like NVMe over Fabrics we need to be able to send initialization commands to a specific queue. Based on an earlier patch from Christoph Hellwig [off-list ref]. Signed-off-by: Ming Lin <redacted> Signed-off-by: Christoph Hellwig <hch@lst.de> --- block/blk-mq.c | 33 +++++++++++++++++++++++++++++++++ include/linux/blk-mq.h | 2 ++ 2 files changed, 35 insertions(+)
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 29cbc1b..7bb45ed 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c@@ -266,6 +266,39 @@ struct request *blk_mq_alloc_request(struct request_queue *q, int rw, } EXPORT_SYMBOL(blk_mq_alloc_request); +struct request *blk_mq_alloc_request_hctx(struct request_queue *q, int rw, + unsigned int flags, unsigned int hctx_idx) +{ + struct blk_mq_hw_ctx *hctx; + struct blk_mq_ctx *ctx; + struct request *rq; + struct blk_mq_alloc_data alloc_data; + int ret; + + ret = blk_queue_enter(q, flags & BLK_MQ_REQ_NOWAIT); + if (ret) + return ERR_PTR(ret); + + hctx = q->queue_hw_ctx[hctx_idx]; + 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); + if (!rq && !(flags & BLK_MQ_REQ_NOWAIT)) { + __blk_mq_run_hw_queue(hctx); + + rq = __blk_mq_alloc_request(&alloc_data, rw); + } + if (!rq) { + blk_queue_exit(q); + return ERR_PTR(-EWOULDBLOCK); + } + + return rq; +} +EXPORT_SYMBOL(blk_mq_alloc_request_hctx); + static void __blk_mq_free_request(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx, struct request *rq) {
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index 2498fdf..6bf8735 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h@@ -196,6 +196,8 @@ enum { struct request *blk_mq_alloc_request(struct request_queue *q, int rw, unsigned int flags); +struct request *blk_mq_alloc_request_hctx(struct request_queue *q, int rw, + unsigned int flags, unsigned int hctx_idx); struct request *blk_mq_tag_to_rq(struct blk_mq_tags *tags, unsigned int tag); struct cpumask *blk_mq_tags_cpumask(struct blk_mq_tags *tags);
--
2.1.4