From: Ming Lei <ming.lei@redhat.com>
Date: Tue, 11 May 2021 23:22:33 +0800
Subject: block: avoid double io accounting for flush request
Patch-mainline: v5.14-rc1
Git-commit: 84da7acc3ba53af26f15c4b0ada446127b7a7836
References: bsc#1193787
For flush request, rq->end_io() may be called two times, one is from
timeout handling(blk_mq_check_expired()), another is from normal
completion(__blk_mq_end_request()).
Move blk_account_io_flush() after flush_rq->ref drops to zero, so
io accounting can be done just once for flush request.
Fixes: b68663186577 ("block: add iostat counters for flush requests")
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Tested-by: John Garry <john.garry@huawei.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20210511152236.763464-2-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Acked-by: Daniel Wagner <dwagner@suse.de>
---
block/blk-flush.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
--- a/block/blk-flush.c
+++ b/block/blk-flush.c
@@ -220,8 +220,6 @@ static void flush_end_io(struct request
unsigned long flags = 0;
struct blk_flush_queue *fq = blk_get_flush_queue(q, flush_rq->mq_ctx);
- blk_account_io_flush(flush_rq);
-
/* release the tag's ownership to the req cloned from */
spin_lock_irqsave(&fq->mq_flush_lock, flags);
@@ -231,6 +229,7 @@ static void flush_end_io(struct request
return;
}
+ blk_account_io_flush(flush_rq);
/*
* Flush request has to be marked as IDLE when it is really ended
* because its .end_io() is called from timeout code path too for