From 5eb6126e1c5c5b69d90003444acc99743881b7b7 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Wed, 22 Mar 2017 15:01:51 -0400 Subject: [PATCH] blk-mq: improve blk_mq_try_issue_directly Rename blk_mq_try_issue_directly to __blk_mq_try_issue_directly and add a new wrapper that takes care of RCU / SRCU locking to avoid having boileplate code in the caller which would get duplicated with new callers. Signed-off-by: Christoph Hellwig Reviewed-by: Bart Van Assche Signed-off-by: Jens Axboe --- block/blk-mq.c | 32 ++++++++++++++++++-------------- 1 file changed, 18 insertions(+), 14 deletions(-) diff --git a/block/blk-mq.c b/block/blk-mq.c index 5a1ff489..e82e1a9 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -1430,7 +1430,7 @@ static blk_qc_t request_to_qc_t(struct blk_mq_hw_ctx *hctx, struct request *rq) return blk_tag_to_qc_t(rq->internal_tag, hctx->queue_num, true); } -static void blk_mq_try_issue_directly(struct request *rq, blk_qc_t *cookie, +static void __blk_mq_try_issue_directly(struct request *rq, blk_qc_t *cookie, bool may_sleep) { struct request_queue *q = rq->q; @@ -1475,13 +1475,27 @@ insert: blk_mq_sched_insert_request(rq, false, true, false, may_sleep); } +static void blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx, + struct request *rq, blk_qc_t *cookie) +{ + if (!(hctx->flags & BLK_MQ_F_BLOCKING)) { + rcu_read_lock(); + __blk_mq_try_issue_directly(rq, cookie, false); + rcu_read_unlock(); + } else { + unsigned int srcu_idx = srcu_read_lock(&hctx->queue_rq_srcu); + __blk_mq_try_issue_directly(rq, cookie, true); + srcu_read_unlock(&hctx->queue_rq_srcu, srcu_idx); + } +} + static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio) { const int is_sync = op_is_sync(bio->bi_opf); const int is_flush_fua = op_is_flush(bio->bi_opf); struct blk_mq_alloc_data data = { .flags = 0 }; struct request *rq; - unsigned int request_count = 0, srcu_idx; + unsigned int request_count = 0; struct blk_plug *plug; struct request *same_queue_rq = NULL; blk_qc_t cookie; @@ -1579,18 +1593,8 @@ static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio) } else /* is_sync */ old_rq = rq; blk_mq_put_ctx(data.ctx); - if (!old_rq) - goto done; - - if (!(data.hctx->flags & BLK_MQ_F_BLOCKING)) { - rcu_read_lock(); - blk_mq_try_issue_directly(old_rq, &cookie, false); - rcu_read_unlock(); - } else { - srcu_idx = srcu_read_lock(&data.hctx->queue_rq_srcu); - blk_mq_try_issue_directly(old_rq, &cookie, true); - srcu_read_unlock(&data.hctx->queue_rq_srcu, srcu_idx); - } + if (old_rq) + blk_mq_try_issue_directly(data.hctx, old_rq, &cookie); goto done; } -- 2.7.4