[PATCH v6 8/8] dm: ensure only power of 2 zone sizes are allowed

[Pankaj Raghav]

Ensure that only power of 2 zoned devices are enabled for dm targets that
supports zoned devices. This constraint can be relaxed once non power of
2 zone size support is added to the DM layer.

Signed-off-by: Pankaj Raghav <p.raghav at samsung.com>
---
 drivers/md/dm-table.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index 03541cfc2317..2a8af70d1d4a 100644
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -251,6 +251,12 @@ static int device_area_is_invalid(struct dm_target *ti, struct dm_dev *dev,
 	if (bdev_is_zoned(bdev)) {
 		unsigned int zone_sectors = bdev_zone_sectors(bdev);
 
+		if (!is_power_of_2(zone_sectors)) {
+			DMWARN("%s: %pg only power of two zone size supported",
+			       dm_device_name(ti->table->md), bdev);
+			return 1;
+		}
+
 		if (start & (zone_sectors - 1)) {
 			DMWARN("%s: start=%llu not aligned to h/w zone size %u of %pg",
 			       dm_device_name(ti->table->md),
-- 
2.25.1