From 360f264834e34d08530c2fb9b67e3ffa65318761 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 19 May 2023 06:40:46 +0200 Subject: blk-mq: defer to the normal submission path for non-flush flush commands If blk_insert_flush decides that a command does not need to use the flush state machine, return false and let blk_mq_submit_bio handle it the normal way (including using an I/O scheduler) instead of doing a bypass insert. Signed-off-by: Christoph Hellwig Reviewed-by: Bart Van Assche Reviewed-by: Damien Le Moal Link: https://lore.kernel.org/r/20230519044050.107790-4-hch@lst.de Signed-off-by: Jens Axboe --- block/blk-flush.c | 22 ++++++++-------------- 1 file changed, 8 insertions(+), 14 deletions(-) (limited to 'block/blk-flush.c') diff --git a/block/blk-flush.c b/block/blk-flush.c index d8144f1f6fb1..6fb9cf2d3818 100644 --- a/block/blk-flush.c +++ b/block/blk-flush.c @@ -385,22 +385,17 @@ static void blk_rq_init_flush(struct request *rq) rq->end_io = mq_flush_data_end_io; } -/** - * blk_insert_flush - insert a new PREFLUSH/FUA request - * @rq: request to insert - * - * To be called from __elv_add_request() for %ELEVATOR_INSERT_FLUSH insertions. - * or __blk_mq_run_hw_queue() to dispatch request. - * @rq is being submitted. Analyze what needs to be done and put it on the - * right queue. +/* + * Insert a PREFLUSH/FUA request into the flush state machine. + * Returns true if the request has been consumed by the flush state machine, + * or false if the caller should continue to process it. */ -void blk_insert_flush(struct request *rq) +bool blk_insert_flush(struct request *rq) { struct request_queue *q = rq->q; unsigned long fflags = q->queue_flags; /* may change, cache */ unsigned int policy = blk_flush_policy(fflags, rq); struct blk_flush_queue *fq = blk_get_flush_queue(q, rq->mq_ctx); - struct blk_mq_hw_ctx *hctx = rq->mq_hctx; /* FLUSH/FUA request must never be merged */ WARN_ON_ONCE(rq->bio != rq->biotail); @@ -429,16 +424,14 @@ void blk_insert_flush(struct request *rq) * complete the request. */ blk_mq_end_request(rq, 0); - return; + return true; case REQ_FSEQ_DATA: /* * If there's data, but no flush is necessary, the request can * be processed directly without going through flush machinery. * Queue for normal execution. */ - blk_mq_request_bypass_insert(rq, 0); - blk_mq_run_hw_queue(hctx, false); - return; + return false; default: /* * Mark the request as part of a flush sequence and submit it @@ -448,6 +441,7 @@ void blk_insert_flush(struct request *rq) spin_lock_irq(&fq->mq_flush_lock); blk_flush_complete_seq(rq, fq, REQ_FSEQ_ACTIONS & ~policy, 0); spin_unlock_irq(&fq->mq_flush_lock); + return true; } } -- cgit