From: Ming Lin <ming.l@xxxxxxxxxxxxxxx>
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@xxxxxx>.
Signed-off-by: Ming Lin <ming.l@xxxxxxxxxxxxxxx>
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
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
--
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