diff options
| -rw-r--r-- | block/blk-mq.c | 39 | ||||
| -rw-r--r-- | include/linux/blk-mq.h | 2 |
2 files changed, 41 insertions, 0 deletions
diff --git a/block/blk-mq.c b/block/blk-mq.c index 13f460368759..7aa60c4f56fd 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -267,6 +267,45 @@ 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; + + /* + * If the tag allocator sleeps we could get an allocation for a + * different hardware context. No need to complicate the low level + * allocator for this for the rare use case of a command tied to + * a specific queue. + */ + if (WARN_ON_ONCE(!(flags & BLK_MQ_REQ_NOWAIT))) + return ERR_PTR(-EINVAL); + + if (hctx_idx >= q->nr_hw_queues) + return ERR_PTR(-EIO); + + ret = blk_queue_enter(q, true); + 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, 0); + if (!rq) { + blk_queue_exit(q); + return ERR_PTR(-EWOULDBLOCK); + } + + return rq; +} +EXPORT_SYMBOL_GPL(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 2498fdf3a503..cbfd8ca5f13e 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 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); |