There are no functional changes, just make code cleaner. Signed-off-by: Yu Kuai --- block/blk-mq.c | 62 ++++++++++++++++++++++++++++++-------------------- 1 file changed, 37 insertions(+), 25 deletions(-) diff --git a/block/blk-mq.c b/block/blk-mq.c index f2650c97a75e..6c505ebfab65 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -497,6 +497,42 @@ __blk_mq_alloc_requests_batch(struct blk_mq_alloc_data *data) return rq_list_pop(data->cached_rqs); } +static void blk_mq_limit_depth(struct blk_mq_alloc_data *data) +{ + struct elevator_mq_ops *ops; + + /* If no I/O scheduler has been configured, don't limit requests */ + if (!data->q->elevator) { + blk_mq_tag_busy(data->hctx); + return; + } + + /* + * All requests use scheduler tags when an I/O scheduler is + * enabled for the queue. + */ + data->rq_flags |= RQF_SCHED_TAGS; + + /* + * Flush/passthrough requests are special and go directly to the + * dispatch list, they are not subject to the async_depth limit. + */ + if ((data->cmd_flags & REQ_OP_MASK) == REQ_OP_FLUSH || + blk_op_is_passthrough(data->cmd_flags)) + return; + + WARN_ON_ONCE(data->flags & BLK_MQ_REQ_RESERVED); + data->rq_flags |= RQF_USE_SCHED; + + /* + * By default, sync requests have no limit, and async requests are + * limited to async_depth. + */ + ops = &data->q->elevator->type->ops; + if (ops->limit_depth) + ops->limit_depth(data->cmd_flags, data); +} + static struct request *__blk_mq_alloc_requests(struct blk_mq_alloc_data *data) { struct request_queue *q = data->q; @@ -515,31 +551,7 @@ static struct request *__blk_mq_alloc_requests(struct blk_mq_alloc_data *data) data->ctx = blk_mq_get_ctx(q); data->hctx = blk_mq_map_queue(data->cmd_flags, data->ctx); - if (q->elevator) { - /* - * All requests use scheduler tags when an I/O scheduler is - * enabled for the queue. - */ - data->rq_flags |= RQF_SCHED_TAGS; - - /* - * Flush/passthrough requests are special and go directly to the - * dispatch list. - */ - if ((data->cmd_flags & REQ_OP_MASK) != REQ_OP_FLUSH && - !blk_op_is_passthrough(data->cmd_flags)) { - struct elevator_mq_ops *ops = &q->elevator->type->ops; - - WARN_ON_ONCE(data->flags & BLK_MQ_REQ_RESERVED); - - data->rq_flags |= RQF_USE_SCHED; - if (ops->limit_depth) - ops->limit_depth(data->cmd_flags, data); - } - } else { - blk_mq_tag_busy(data->hctx); - } - + blk_mq_limit_depth(data); if (data->flags & BLK_MQ_REQ_RESERVED) data->rq_flags |= RQF_RESV; -- 2.51.0