Messages in this thread | | | Subject | Re: [PATCH -next] raid10: fix leak of io accounting | From | Yu Kuai <> | Date | Thu, 9 Mar 2023 14:56:49 +0800 |
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Hi,
在 2023/03/09 14:36, Guoqing Jiang 写道: > Hi, > > What do you mean 'leak' here?
I try to mean that inflight counting is leaked, because it's increased twice for one io. > > On 3/4/23 15:01, Yu Kuai wrote: >> From: Yu Kuai <yukuai3@huawei.com> >> >> handle_read_error() will resumit r10_bio by raid10_read_request(), which >> will call bio_start_io_acct() again, while bio_end_io_acct() will only >> be called once. >> >> Fix the problem by don't account io again from handle_read_error(). > > My understanding is it caused inaccurate io stats for bio which had a read > error. > >> Fixes: 528bc2cf2fcc ("md/raid10: enable io accounting") >> Signed-off-by: Yu Kuai <yukuai3@huawei.com> >> --- >> drivers/md/raid10.c | 8 ++++---- >> 1 file changed, 4 insertions(+), 4 deletions(-) >> >> diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c >> index 6c66357f92f5..4f8edb6ea3e2 100644 >> --- a/drivers/md/raid10.c >> +++ b/drivers/md/raid10.c >> @@ -1173,7 +1173,7 @@ static bool regular_request_wait(struct mddev >> *mddev, struct r10conf *conf, >> } >> static void raid10_read_request(struct mddev *mddev, struct bio *bio, >> - struct r10bio *r10_bio) >> + struct r10bio *r10_bio, bool handle_error) >> { >> struct r10conf *conf = mddev->private; >> struct bio *read_bio; >> @@ -1244,7 +1244,7 @@ static void raid10_read_request(struct mddev >> *mddev, struct bio *bio, >> } >> slot = r10_bio->read_slot; >> - if (blk_queue_io_stat(bio->bi_bdev->bd_disk->queue)) >> + if (!handle_error && >> blk_queue_io_stat(bio->bi_bdev->bd_disk->queue)) >> r10_bio->start_time = bio_start_io_acct(bio); > > I think a simpler way is just check R10BIO_ReadError here.
No, I'm afraid this is incorrect because handle_read_error clears the state before resubmiting the r10bio.
Thanks, Kuai > > Thanks, > Guoqing > . >
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