diff options
| -rw-r--r-- | block/blk-mq.c | 80 |
1 files changed, 71 insertions, 9 deletions
diff --git a/block/blk-mq.c b/block/blk-mq.c index 83492d942348..b32f70f38c6e 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -510,25 +510,87 @@ retry: alloc_time_ns); } -struct request *blk_mq_alloc_request(struct request_queue *q, blk_opf_t opf, - blk_mq_req_flags_t flags) +static struct request *blk_mq_rq_cache_fill(struct request_queue *q, + struct blk_plug *plug, + blk_opf_t opf, + blk_mq_req_flags_t flags) { struct blk_mq_alloc_data data = { .q = q, .flags = flags, .cmd_flags = opf, - .nr_tags = 1, + .nr_tags = plug->nr_ios, + .cached_rq = &plug->cached_rq, }; struct request *rq; - int ret; - ret = blk_queue_enter(q, flags); - if (ret) - return ERR_PTR(ret); + if (blk_queue_enter(q, flags)) + return NULL; + + plug->nr_ios = 1; rq = __blk_mq_alloc_requests(&data); - if (!rq) - goto out_queue_exit; + if (unlikely(!rq)) + blk_queue_exit(q); + return rq; +} + +static struct request *blk_mq_alloc_cached_request(struct request_queue *q, + blk_opf_t opf, + blk_mq_req_flags_t flags) +{ + struct blk_plug *plug = current->plug; + struct request *rq; + + if (!plug) + return NULL; + if (rq_list_empty(plug->cached_rq)) { + if (plug->nr_ios == 1) + return NULL; + rq = blk_mq_rq_cache_fill(q, plug, opf, flags); + if (rq) + goto got_it; + return NULL; + } + rq = rq_list_peek(&plug->cached_rq); + if (!rq || rq->q != q) + return NULL; + + if (blk_mq_get_hctx_type(opf) != rq->mq_hctx->type) + return NULL; + if (op_is_flush(rq->cmd_flags) != op_is_flush(opf)) + return NULL; + + plug->cached_rq = rq_list_next(rq); +got_it: + rq->cmd_flags = opf; + INIT_LIST_HEAD(&rq->queuelist); + return rq; +} + +struct request *blk_mq_alloc_request(struct request_queue *q, blk_opf_t opf, + blk_mq_req_flags_t flags) +{ + struct request *rq; + + rq = blk_mq_alloc_cached_request(q, opf, flags); + if (!rq) { + struct blk_mq_alloc_data data = { + .q = q, + .flags = flags, + .cmd_flags = opf, + .nr_tags = 1, + }; + int ret; + + ret = blk_queue_enter(q, flags); + if (ret) + return ERR_PTR(ret); + + rq = __blk_mq_alloc_requests(&data); + if (!rq) + goto out_queue_exit; + } rq->__data_len = 0; rq->__sector = (sector_t) -1; rq->bio = rq->biotail = NULL; |