blk-mq: add blk_mq_alloc_request_hctx
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 <hch@lst.de>.
Signed-off-by: Ming Lin <ming.l@ssi.samsung.com>
[hch: disallow sleeping allocation, req_op fixes]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index 2498fdf..cbfd8ca 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -196,6 +196,8 @@
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 op,
+ 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);