Re: [PATCH v2 4/5] dm-stripe: limit chunk_sectors to the stripe size

From: Mikulas Patocka
Date: Mon Jun 23 2025 - 05:50:22 EST




On Wed, 18 Jun 2025, John Garry wrote:

> Same as done for raid0, set chunk_sectors limit to appropriately set the
> atomic write size limit.
>
> Setting chunk_sectors limit in this way overrides the stacked limit
> already calculated based on the bottom device limits. This is ok, as
> when any bios are sent to the bottom devices, the block layer will still
> respect the bottom device chunk_sectors.
>
> Signed-off-by: John Garry <john.g.garry@xxxxxxxxxx>
> ---
> drivers/md/dm-stripe.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/md/dm-stripe.c b/drivers/md/dm-stripe.c
> index a7dc04bd55e5..5bbbdf8fc1bd 100644
> --- a/drivers/md/dm-stripe.c
> +++ b/drivers/md/dm-stripe.c
> @@ -458,6 +458,7 @@ static void stripe_io_hints(struct dm_target *ti,
> struct stripe_c *sc = ti->private;
> unsigned int chunk_size = sc->chunk_size << SECTOR_SHIFT;
>
> + limits->chunk_sectors = sc->chunk_size;
> limits->io_min = chunk_size;
> limits->io_opt = chunk_size * sc->stripes;
> }
> --
> 2.31.1

Reviewed-by: Mikulas Patocka <mpatocka@xxxxxxxxxx>