Hi,
在 2023/06/09 17:43, linan666@xxxxxxxxxxxxxxx 写道:
From: Li Nan <linan122@xxxxxxxxxx>
/sys/block/[device]/queue/iostats is used to control whether to count io
stat. Write 0 to it will clear queue_flags QUEUE_FLAG_IO_STAT which means
iostats is disabled. If we disable iostats and later endable it, the io
issued during this period will be counted incorrectly, inflight will be
decreased to -1.
//T1 set iostats
echo 0 > /sys/block/md0/queue/iostats
clear QUEUE_FLAG_IO_STAT
//T2 issue io
if (QUEUE_FLAG_IO_STAT) -> false
bio_start_io_acct
inflight++
echo 1 > /sys/block/md0/queue/iostats
set QUEUE_FLAG_IO_STAT
//T3 io end
if (QUEUE_FLAG_IO_STAT) -> true
bio_end_io_acct
inflight-- -> -1
Also, if iostats is enabled while issuing io but disabled while io end,
inflight will never be decreased.
Fix it by checking start_time when io end. Only check QUEUE_FLAG_IO_STAT
while issuing io, just like request based devices.
Fixes: 528bc2cf2fcc ("md/raid10: enable io accounting")
Signed-off-by: Li Nan <linan122@xxxxxxxxxx>
---
drivers/md/raid10.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 381c21f7fb06..bf9dca5c25c3 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -325,7 +325,7 @@ static void raid_end_bio_io(struct r10bio *r10_bio)
if (!test_bit(R10BIO_Uptodate, &r10_bio->state))
bio->bi_status = BLK_STS_IOERR;
- if (blk_queue_io_stat(bio->bi_bdev->bd_disk->queue))
+ if (r10_bio->start_time)
bio_end_io_acct(bio, r10_bio->start_time);
This patch LGTM, can you change this for raid1 as well? raid0 and
raid456 is using md_account_bio(), and they don't have such problem.
Thanks,
Kuai
bio_endio(bio);
/*
