2023-05-24 01:51:18

by Yu Kuai

[permalink] [raw]
Subject: [PATCH] md/raid5: fix miscalculation of 'end_sector' in raid5_read_one_chunk()

From: Yu Kuai <[email protected]>

'end_sector' is compared to 'rdev->recovery_offset', which is offset to
rdev, however, commit e82ed3a4fbb5 ("md/raid6: refactor
raid5_read_one_chunk") changes the calculation of 'end_sector' to offset
to the array. Fix this miscalculation.

Fixes: e82ed3a4fbb5 ("md/raid6: refactor raid5_read_one_chunk")
Signed-off-by: Yu Kuai <[email protected]>
---
drivers/md/raid5.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 7e2bbcfef325..8686d629e3f2 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -5516,7 +5516,7 @@ static int raid5_read_one_chunk(struct mddev *mddev, struct bio *raid_bio)

sector = raid5_compute_sector(conf, raid_bio->bi_iter.bi_sector, 0,
&dd_idx, NULL);
- end_sector = bio_end_sector(raid_bio);
+ end_sector = sector + bio_sectors(raid_bio);

rcu_read_lock();
if (r5c_big_stripe_cached(conf, sector))
--
2.39.2



2023-05-24 15:09:51

by Jens Axboe

[permalink] [raw]
Subject: Re: [PATCH] md/raid5: fix miscalculation of 'end_sector' in raid5_read_one_chunk()

On 5/23/23 7:41 PM, Yu Kuai wrote:
> From: Yu Kuai <[email protected]>
>
> 'end_sector' is compared to 'rdev->recovery_offset', which is offset to
> rdev, however, commit e82ed3a4fbb5 ("md/raid6: refactor
> raid5_read_one_chunk") changes the calculation of 'end_sector' to offset
> to the array. Fix this miscalculation.
>
> Fixes: e82ed3a4fbb5 ("md/raid6: refactor raid5_read_one_chunk")

This needs a stable tag as well, Fixes alone is not enough to guarantee
it ends up in stable.

Song, are you picking this up?

--
Jens Axboe



2023-05-24 17:35:42

by Song Liu

[permalink] [raw]
Subject: Re: [PATCH] md/raid5: fix miscalculation of 'end_sector' in raid5_read_one_chunk()

On Wed, May 24, 2023 at 8:03 AM Jens Axboe <[email protected]> wrote:
>
> On 5/23/23 7:41 PM, Yu Kuai wrote:
> > From: Yu Kuai <[email protected]>
> >
> > 'end_sector' is compared to 'rdev->recovery_offset', which is offset to
> > rdev, however, commit e82ed3a4fbb5 ("md/raid6: refactor
> > raid5_read_one_chunk") changes the calculation of 'end_sector' to offset
> > to the array. Fix this miscalculation.
> >
> > Fixes: e82ed3a4fbb5 ("md/raid6: refactor raid5_read_one_chunk")
>
> This needs a stable tag as well, Fixes alone is not enough to guarantee
> it ends up in stable.
>
> Song, are you picking this up?

Yes, I will test it and send it via md-fixes.

Thanks,
Song