[5/7] dm-zoned: ensure only power of 2 zone sizes are allowed

Message ID 20230106083317.93938-6-p.raghav@samsung.com
State New
Headers
Series block zoned cleanups |

Commit Message

Pankaj Raghav Jan. 6, 2023, 8:33 a.m. UTC
  From: Luis Chamberlain <mcgrof@kernel.org>

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@suse.de>
Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Mike Snitzer <snitzer@kernel.org>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Pankaj Raghav <p.raghav@samsung.com>
---
 drivers/md/dm-zoned-target.c | 8 ++++++++
 1 file changed, 8 insertions(+)
  

Comments

Christoph Hellwig Jan. 10, 2023, 6:56 a.m. UTC | #1
Given that we don't even support the non pow of 2 zones in the block
layer I don't see why this is needed.  But either way it doesn't really
seem to fit into this series.
  
Pankaj Raghav Jan. 10, 2023, 8:39 a.m. UTC | #2
On 2023-01-10 07:56, Christoph Hellwig wrote:
> Given that we don't even support the non pow of 2 zones in the block
> layer I don't see why this is needed.  But either way it doesn't really
> seem to fit into this series.

You are right. It is just an extra stop gap, but it is not needed as block
layer does not support pow of 2 anyway! I will remove this patch in the
next version.
  

Patch

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);
 	}