int nilfs_attach_checkpoint(struct super_block *sb, __u64 cno, int curr_mnt,
struct nilfs_root **root);
int nilfs_checkpoint_is_mounted(struct super_block *sb, __u64 cno);
int nilfs_attach_checkpoint(struct super_block *sb, __u64 cno, int curr_mnt,
struct nilfs_root **root);
int nilfs_checkpoint_is_mounted(struct super_block *sb, __u64 cno);