From: Johannes Thumshirn johannes.thumshirn@wdc.com
stable inclusion from linux-4.19.164 commit 7894076fbc90e8c2528e339d50f0e669a6e7fc7a
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[ 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 johannes.thumshirn@wdc.com Reviewed-by: Christoph Hellwig hch@lst.de Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Yang Yingliang yangyingliang@huawei.com Signed-off-by: Cheng Jian cj.chengjian@huawei.com --- 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 d095fe0b2ac0..795ed40ce415 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -1142,6 +1142,23 @@ 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. */ @@ -1213,17 +1230,7 @@ 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; }