_cd9660node
struct _cd9660node *parent; /* parent (NULL if root) */
TAILQ_HEAD(cd9660_children_head, _cd9660node) cn_children;
TAILQ_ENTRY(_cd9660node) cn_next_child;
struct _cd9660node *dot_record; /* For directories, used mainly in RRIP */
struct _cd9660node *dot_dot_record;
struct _cd9660node *rr_real_parent, *rr_relocated;
struct _cd9660node *ptnext, *ptprev, *ptlast;
struct _cd9660node *boot_image_node;