From 4f3e3fa6239d52378e251382d84ab0932483e674 Mon Sep 17 00:00:00 2001 From: Johannes Thumshirn Date: Wed, 25 Mar 2020 00:24:44 +0900 Subject: [PATCH] block: factor out requeue handling from dispatch code [ Upstream commit c92a41031a6d57395889b5c87cea359220a24d2a ] Factor out the requeue handling from the dispatch code, this will make subsequent addition of different requeueing schemes easier. Signed-off-by: Johannes Thumshirn Reviewed-by: Christoph Hellwig Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- block/blk-mq.c | 29 ++++++++++++++++++----------- 1 file changed, 18 insertions(+), 11 deletions(-) diff --git a/block/blk-mq.c b/block/blk-mq.c index b748d1e63f9c..c0efd3e278da 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -1205,6 +1205,23 @@ static void blk_mq_update_dispatch_busy(struct blk_mq_hw_ctx *hctx, bool busy) #define BLK_MQ_RESOURCE_DELAY 3 /* ms units */ +static void blk_mq_handle_dev_resource(struct request *rq, + struct list_head *list) +{ + struct request *next = + list_first_entry_or_null(list, struct request, queuelist); + + /* + * If an I/O scheduler has been configured and we got a driver tag for + * the next request already, free it. + */ + if (next) + blk_mq_put_driver_tag(next); + + list_add(&rq->queuelist, list); + __blk_mq_requeue_request(rq); +} + /* * Returns true if we did some work AND can potentially do more. */ @@ -1274,17 +1291,7 @@ bool blk_mq_dispatch_rq_list(struct request_queue *q, struct list_head *list, ret = q->mq_ops->queue_rq(hctx, &bd); if (ret == BLK_STS_RESOURCE || ret == BLK_STS_DEV_RESOURCE) { - /* - * If an I/O scheduler has been configured and we got a - * driver tag for the next request already, free it - * again. - */ - if (!list_empty(list)) { - nxt = list_first_entry(list, struct request, queuelist); - blk_mq_put_driver_tag(nxt); - } - list_add(&rq->queuelist, list); - __blk_mq_requeue_request(rq); + blk_mq_handle_dev_resource(rq, list); break; }