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From:   Pankaj Raghav <p.raghav@samsung.com>
To:     agk@redhat.com, snitzer@kernel.org, axboe@kernel.dk,
        damien.lemoal@opensource.wdc.com, hch@lst.de
Cc:     pankydev8@gmail.com, Johannes.Thumshirn@wdc.com,
        linux-block@vger.kernel.org, dm-devel@redhat.com, hare@suse.de,
        jaegeuk@kernel.org, linux-kernel@vger.kernel.org,
        matias.bjorling@wdc.com, gost.dev@samsung.com, bvanassche@acm.org,
        linux-nvme@lists.infradead.org,
        Luis Chamberlain <mcgrof@kernel.org>,
        Pankaj Raghav <p.raghav@samsung.com>
Subject: [PATCH v12 08/13] dm-zoned: ensure only power of 2 zone sizes are
 allowed
Date:   Tue, 23 Aug 2022 14:18:54 +0200
Message-Id: <20220823121859.163903-9-p.raghav@samsung.com>
In-Reply-To: <20220823121859.163903-1-p.raghav@samsung.com>
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        <CGME20220823121909eucas1p113c0c29f7e28d0ee3e1161f7da243baf@eucas1p1.samsung.com>
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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>
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(+)

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