btrfs: zoned: do not load fs_info::zoned from incompat flag

Don't set the zoned flag in fs_info as soon as we're encountering the
incompat filesystem flag for a zoned filesystem on mount. The zoned flag
in fs_info is in a union together with the zone_size, so setting it too
early will result in setting an incorrect zone_size as well.

Once the correct zone_size is read from the device, we can rely on the
zoned flag in fs_info as well to determine if the filesystem is zoned.
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/disk-io.c

@@ -3201,8 +3201,6 @@ int __cold open_ctree(struct super_block *sb, struct btrfs_fs_devices *fs_device
 	if (features & BTRFS_FEATURE_INCOMPAT_SKINNY_METADATA)
 		btrfs_info(fs_info, "has skinny extents");
 
-	fs_info->zoned = (features & BTRFS_FEATURE_INCOMPAT_ZONED);
-
 	/*
 	 * flag our filesystem as having big metadata blocks if
 	 * they are bigger than the page size

fs/btrfs/zoned.c

@@ -432,6 +432,14 @@ int btrfs_check_zoned_mode(struct btrfs_fs_info *fs_info)
 	fs_info->zone_size = zone_size;
 	fs_info->max_zone_append_size = max_zone_append_size;
 
+	/*
+	 * Check mount options here, because we might change fs_info->zoned
+	 * from fs_info->zone_size.
+	 */
+	ret = btrfs_check_mountopts_zoned(fs_info);
+	if (ret)
+		goto out;
+
 	btrfs_info(fs_info, "zoned mode enabled with zone size %llu", zone_size);
 out:
 	return ret;