btrfs_check_super_csum
if (btrfs_check_super_csum(fs_info, disk_super)) {
int btrfs_check_super_csum(struct btrfs_fs_info *fs_info,
ret = btrfs_check_super_csum(fs_info, sb);
if (unlikely(btrfs_check_super_csum(fs_info, sb))) {