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authorChristoph Hellwig2021-10-19 14:25:53 +0200
committerJens Axboe2021-10-19 11:10:09 -0600
commitd92ca9d8348fb12c89eac5928bd651c3a485d7b9 (patch)
tree05d9098b647cd912977e1f87fa297fd9c543ffde /block/blk-mq.c
parentdc5fc361d891e089dfd9c0a975dc78041036b906 (diff)
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 <hch@lst.de> Link: https://lore.kernel.org/r/20211019122553.2467817-1-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/blk-mq.c')
-rw-r--r--block/blk-mq.c14
1 files changed, 6 insertions, 8 deletions
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 71ab7521dd3d..3481a8712234 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -2532,14 +2532,12 @@ void blk_mq_submit_bio(struct bio *bio)
return;
}
- if (unlikely(is_flush_fua)) {
- struct blk_mq_hw_ctx *hctx = rq->mq_hctx;
- /* Bypass scheduler for flush requests */
- blk_insert_flush(rq);
- blk_mq_run_hw_queue(hctx, true);
- } else if (plug && (q->nr_hw_queues == 1 ||
- blk_mq_is_shared_tags(rq->mq_hctx->flags) ||
- q->mq_ops->commit_rqs || !blk_queue_nonrot(q))) {
+ if (is_flush_fua && blk_insert_flush(rq))
+ return;
+
+ if (plug && (q->nr_hw_queues == 1 ||
+ blk_mq_is_shared_tags(rq->mq_hctx->flags) ||
+ q->mq_ops->commit_rqs || !blk_queue_nonrot(q))) {
/*
* Use plugging if we have a ->commit_rqs() hook as well, as
* we know the driver uses bd->last in a smart fashion.