[PATCH -v2] md/raid10: Don't call bio_start_io_acct twice for bio which experienced read error

From: Yu Kuai
Date: Thu Mar 09 2023 - 07:34:42 EST


From: Yu Kuai <yukuai3@xxxxxxxxxx>

handle_read_error() will resubmit 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().

Fixes: 528bc2cf2fcc ("md/raid10: enable io accounting")
Signed-off-by: Yu Kuai <yukuai3@xxxxxxxxxx>
Acked-by: Guoqing Jiang <guoqing.jiang@xxxxxxxxx>
---
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);
read_bio = bio_alloc_clone(rdev->bdev, bio, gfp, &mddev->bio_set);

@@ -1578,7 +1578,7 @@ static void __make_request(struct mddev *mddev, struct bio *bio, int sectors)
conf->geo.raid_disks);

if (bio_data_dir(bio) == READ)
- raid10_read_request(mddev, bio, r10_bio);
+ raid10_read_request(mddev, bio, r10_bio, false);
else
raid10_write_request(mddev, bio, r10_bio);
}
@@ -2980,7 +2980,7 @@ static void handle_read_error(struct mddev *mddev, struct r10bio *r10_bio)
rdev_dec_pending(rdev, mddev);
allow_barrier(conf);
r10_bio->state = 0;
- raid10_read_request(mddev, r10_bio->master_bio, r10_bio);
+ raid10_read_request(mddev, r10_bio->master_bio, r10_bio, true);
}

static void handle_write_completed(struct r10conf *conf, struct r10bio *r10_bio)
--
2.31.1