[PATCH v4 13/13] dm-zoned: ensure only power of 2 zone sizes are allowed

Pankaj Raghav
2022-05-16T16:55:23Z

From: Luis Chamberlain <mcgrof@kernel.org>

Today dm-zoned relies on the assumption that you have a zone size
with a power of 2. Even though the block layer today enforces this
requirement, these devices do exist and so provide a stop-gap measure
to ensure these devices cannot be used by mistake

Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Pankaj Raghav <p.raghav@samsung.com>
---
drivers/md/dm-zone.c | 12 ++++++++++++
1 file changed, 12 insertions(+)

diff --git a/drivers/md/dm-zone.c b/drivers/md/dm-zone.c
index 3e7b1fe15..f0c588c02 100644
--- a/drivers/md/dm-zone.c
+++ b/drivers/md/dm-zone.c
@@ -231,6 +231,18 @@ static int dm_revalidate_zones(struct mapped_device *md, struct dm_table *t)
struct request_queue *q = md->queue;
unsigned int noio_flag;
int ret;
+ struct block_device *bdev = md->disk->part0;
+ sector_t zone_sectors;
+ char bname[BDEVNAME_SIZE];
+
+ zone_sectors = bdev_zone_sectors(bdev);
+
+ if (!is_power_of_2(zone_sectors)) {
+ DMWARN("%s: %s only power of two zone size supported",
+ dm_device_name(md),
+ bdevname(bdev, bname));
+ return -EINVAL;
+ }

/*
* Check if something changed. If yes, cleanup the current resources
--
2.25.1