From 53548d2a945eb2c277332c66f57505881392e5a9 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 13 Apr 2023 08:40:47 +0200 Subject: blk-mq: refactor passthrough vs flush handling in blk_mq_insert_request While both passthrough and flush requests call directly into blk_mq_request_bypass_insert, the parameters aren't the same. Split the handling into two separate conditionals and turn the whole function into an if/elif/elif/else flow instead of the gotos. Signed-off-by: Christoph Hellwig Reviewed-by: Bart Van Assche Reviewed-by: Damien Le Moal Link: https://lore.kernel.org/r/20230413064057.707578-11-hch@lst.de Signed-off-by: Jens Axboe --- block/blk-mq.c | 50 ++++++++++++++++++-------------------------------- 1 file changed, 18 insertions(+), 32 deletions(-) (limited to 'block/blk-mq.c') diff --git a/block/blk-mq.c b/block/blk-mq.c index 7e9f7d00452f..c3de03217f4f 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -2506,37 +2506,26 @@ out: blk_mq_run_hw_queue(hctx, run_queue_async); } -static bool blk_mq_sched_bypass_insert(struct blk_mq_hw_ctx *hctx, - struct request *rq) -{ - /* - * dispatch flush and passthrough rq directly - * - * passthrough request has to be added to hctx->dispatch directly. - * For some reason, device may be in one situation which can't - * handle FS request, so STS_RESOURCE is always returned and the - * FS request will be added to hctx->dispatch. However passthrough - * request may be required at that time for fixing the problem. If - * passthrough request is added to scheduler queue, there isn't any - * chance to dispatch it given we prioritize requests in hctx->dispatch. - */ - if ((rq->rq_flags & RQF_FLUSH_SEQ) || blk_rq_is_passthrough(rq)) - return true; - - return false; -} - static void blk_mq_insert_request(struct request *rq, bool at_head, bool run_queue, bool async) { struct request_queue *q = rq->q; - struct elevator_queue *e = q->elevator; struct blk_mq_ctx *ctx = rq->mq_ctx; struct blk_mq_hw_ctx *hctx = rq->mq_hctx; - WARN_ON(e && (rq->tag != BLK_MQ_NO_TAG)); - - if (blk_mq_sched_bypass_insert(hctx, rq)) { + if (blk_rq_is_passthrough(rq)) { + /* + * Passthrough request have to be added to hctx->dispatch + * directly. The device may be in a situation where it can't + * handle FS request, and always returns BLK_STS_RESOURCE for + * them, which gets them added to hctx->dispatch. + * + * If a passthrough request is required to unblock the queues, + * and it is added to the scheduler queue, there is no chance to + * dispatch it given we prioritize requests in hctx->dispatch. + */ + blk_mq_request_bypass_insert(rq, at_head, false); + } else if (rq->rq_flags & RQF_FLUSH_SEQ) { /* * Firstly normal IO request is inserted to scheduler queue or * sw queue, meantime we add flush request to dispatch queue( @@ -2558,16 +2547,14 @@ static void blk_mq_insert_request(struct request *rq, bool at_head, * Simply queue flush rq to the front of hctx->dispatch so that * intensive flush workloads can benefit in case of NCQ HW. */ - at_head = (rq->rq_flags & RQF_FLUSH_SEQ) ? true : at_head; - blk_mq_request_bypass_insert(rq, at_head, false); - goto run; - } - - if (e) { + blk_mq_request_bypass_insert(rq, true, false); + } else if (q->elevator) { LIST_HEAD(list); + WARN_ON_ONCE(rq->tag != BLK_MQ_NO_TAG); + list_add(&rq->queuelist, &list); - e->type->ops.insert_requests(hctx, &list, at_head); + q->elevator->type->ops.insert_requests(hctx, &list, at_head); } else { trace_block_rq_insert(rq); @@ -2581,7 +2568,6 @@ static void blk_mq_insert_request(struct request *rq, bool at_head, spin_unlock(&ctx->lock); } -run: if (run_queue) blk_mq_run_hw_queue(hctx, async); } -- cgit v1.2.3