[PATCH v15 08/13] dm-zoned: ensure only power of 2 zone sizes are allowed

From: Pankaj Raghav
Date: Fri Sep 23 2022 - 13:37:33 EST


From: Luis Chamberlain <mcgrof@xxxxxxxxxx>

dm-zoned relies on the assumption that the zone size is a
power-of-2(po2) and the zone capacity is same as the zone size.

Ensure only po2 devices can be used as dm-zoned target until a native
support for zoned devices with non-po2 zone size is added.

Reviewed-by: Hannes Reinecke <hare@xxxxxxx>
Reviewed-by: Damien Le Moal <damien.lemoal@xxxxxxxxxxxxxxxxxx>
Reviewed-by: Bart Van Assche <bvanassche@xxxxxxx>
Reviewed-by: Mike Snitzer <snitzer@xxxxxxxxxx>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@xxxxxxx>
Signed-off-by: Luis Chamberlain <mcgrof@xxxxxxxxxx>
Signed-off-by: Pankaj Raghav <p.raghav@xxxxxxxxxxx>
---
drivers/md/dm-zoned-target.c | 8 ++++++++
1 file changed, 8 insertions(+)

diff --git a/drivers/md/dm-zoned-target.c b/drivers/md/dm-zoned-target.c
index 95b132b52f33..9325bf5dee81 100644
--- a/drivers/md/dm-zoned-target.c
+++ b/drivers/md/dm-zoned-target.c
@@ -792,6 +792,10 @@ static int dmz_fixup_devices(struct dm_target *ti)
return -EINVAL;
}
zone_nr_sectors = bdev_zone_sectors(bdev);
+ if (!is_power_of_2(zone_nr_sectors)) {
+ ti->error = "Zone size is not a power-of-2 number of sectors";
+ return -EINVAL;
+ }
zoned_dev->zone_nr_sectors = zone_nr_sectors;
zoned_dev->nr_zones = bdev_nr_zones(bdev);
}
@@ -804,6 +808,10 @@ static int dmz_fixup_devices(struct dm_target *ti)
return -EINVAL;
}
zoned_dev->zone_nr_sectors = bdev_zone_sectors(bdev);
+ if (!is_power_of_2(zoned_dev->zone_nr_sectors)) {
+ ti->error = "Zone size is not a power-of-2 number of sectors";
+ return -EINVAL;
+ }
zoned_dev->nr_zones = bdev_nr_zones(bdev);
}

--
2.25.1