Re: [PATCH v8 10/11] dm: call dm_zone_endio after the target endio callback for zoned devices

From: Damien Le Moal
Date: Wed Jul 27 2022 - 23:26:05 EST


On 7/28/22 01:22, Pankaj Raghav wrote:
> dm_zone_endio() updates the bi_sector of orig bio for zoned devices that
> uses either native append or append emulation and it is called before the
> endio of the target. But target endio can still update the clone bio
> after dm_zone_endio is called, thereby, the orig bio does not contain
> the updated information anymore. Call dm_zone_endio for zoned devices
> after calling the target's endio function
>
> Signed-off-by: Pankaj Raghav <p.raghav@xxxxxxxxxxx>
> ---
> drivers/md/dm.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/md/dm.c b/drivers/md/dm.c
> index 03ac6143b8aa..bc410ee04004 100644
> --- a/drivers/md/dm.c
> +++ b/drivers/md/dm.c
> @@ -1123,10 +1123,6 @@ static void clone_endio(struct bio *bio)
> disable_write_zeroes(md);
> }
>
> - if (static_branch_unlikely(&zoned_enabled) &&
> - unlikely(bdev_is_zoned(bio->bi_bdev)))
> - dm_zone_endio(io, bio);
> -
> if (endio) {
> int r = endio(ti, bio, &error);
> switch (r) {
> @@ -1155,6 +1151,10 @@ static void clone_endio(struct bio *bio)
> }
> }
>
> + if (static_branch_unlikely(&zoned_enabled) &&
> + unlikely(bdev_is_zoned(bio->bi_bdev)))
> + dm_zone_endio(io, bio);
> +
> if (static_branch_unlikely(&swap_bios_enabled) &&
> unlikely(swap_bios_limit(ti, bio)))
> up(&md->swap_bios_semaphore);

This patch seems completely unrelated to the series topic. Is that a bug
fix ? How do you trigger it ? Our tests do not show any issues here...
If this triggers only with non power of 2 zone size devices, then this
should be squashed in patch 8. And patch 9 could also be squashed with
patch 8 too.

--
Damien Le Moal
Western Digital Research