dm-stripe: limit chunk_sectors to the stripe size

JIRA: https://issues.redhat.com/browse/RHEL-106845

commit 5fb9d43
Author: John Garry <john.g.garry@oracle.com>
Date:   Fri Jul 11 10:52:57 2025 +0000

    dm-stripe: limit chunk_sectors to the stripe size

    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.

    Reviewed-by: Nilay Shroff <nilay@linux.ibm.com>
    Reviewed-by: Mikulas Patocka <mpatocka@redhat.com>
    Signed-off-by: John Garry <john.g.garry@oracle.com>
    Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
    Link: https://lore.kernel.org/r/20250711105258.3135198-6-john.g.garry@oracle.com
    Signed-off-by: Jens Axboe <axboe@kernel.dk>

Signed-off-by: Ming Lei <ming.lei@redhat.com>

Author: Ming Lei

drivers/md/dm-stripe.c

@@ -459,6 +459,7 @@ 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;
 }