btrfs: zoned: fail mount if the device does not support zone append

For zoned btrfs, zone append is mandatory to write to a sequential write
only zone, otherwise parallel writes to the same zone could result in
unaligned write errors.

If a zoned block device does not support zone append (e.g. a dm-crypt
zoned device using a non-NULL IV cypher), fail to mount.

CC: stable@vger.kernel.org # 5.12
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c
index eeb3ebe11d7ae4c19c157239d1cc37fc1af63a60..70b23a0d03b1043df7b81c7fcc0a0d1343ef4ec7 100644 (file)
--- a/fs/btrfs/zoned.c
+++ b/fs/btrfs/zoned.c
@@ -342,6 +342,13 @@ int btrfs_get_dev_zone_info(struct btrfs_device *device)
        if (!IS_ALIGNED(nr_sectors, zone_sectors))
                zone_info->nr_zones++;
 
+       if (bdev_is_zoned(bdev) && zone_info->max_zone_append_size == 0) {
+               btrfs_err(fs_info, "zoned: device %pg does not support zone append",
+                         bdev);
+               ret = -EINVAL;
+               goto out;
+       }
+
        zone_info->seq_zones = bitmap_zalloc(zone_info->nr_zones, GFP_KERNEL);
        if (!zone_info->seq_zones) {
                ret = -ENOMEM;