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@oracle.com>
---
 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

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@oracle.com>
> ---
>  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@redhat.com>

On 6/18/25 2:07 PM, 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@oracle.com>

Looks good to me:
Reviewed-by: Nilay Shroff <nilay@linux.ibm.com>