From d92ca9d8348fb12c89eac5928bd651c3a485d7b9 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 19 Oct 2021 14:25:53 +0200 Subject: blk-mq: don't handle non-flush requests in blk_insert_flush Return to the normal blk_mq_submit_bio flow if the bio did not end up actually being a flush because the device didn't support it. Note that this is basically impossible to hit without special instrumentation given that submit_bio_checks already clears these flags usually, so we'd need a tight race to actually hit this code path. With this the call to blk_mq_run_hw_queue for the flush requests can be removed given that the actual flush requests are always issued via the requeue workqueue which runs the queue unconditionally. Signed-off-by: Christoph Hellwig Link: https://lore.kernel.org/r/20211019122553.2467817-1-hch@lst.de Signed-off-by: Jens Axboe --- block/blk-flush.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) (limited to 'block/blk-flush.c') diff --git a/block/blk-flush.c b/block/blk-flush.c index 4201728bf3a5..8e364bda5166 100644 --- a/block/blk-flush.c +++ b/block/blk-flush.c @@ -379,7 +379,7 @@ static void mq_flush_data_end_io(struct request *rq, blk_status_t error) * @rq is being submitted. Analyze what needs to be done and put it on the * right queue. */ -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 */ @@ -409,7 +409,7 @@ void blk_insert_flush(struct request *rq) */ if (!policy) { blk_mq_end_request(rq, 0); - return; + return true; } BUG_ON(rq->bio != rq->biotail); /*assumes zero or single bio rq */ @@ -420,10 +420,8 @@ void blk_insert_flush(struct request *rq) * for normal execution. */ if ((policy & REQ_FSEQ_DATA) && - !(policy & (REQ_FSEQ_PREFLUSH | REQ_FSEQ_POSTFLUSH))) { - blk_mq_request_bypass_insert(rq, false, false); - return; - } + !(policy & (REQ_FSEQ_PREFLUSH | REQ_FSEQ_POSTFLUSH))) + return false; /* * @rq should go through flush machinery. Mark it part of flush @@ -439,6 +437,8 @@ 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