po_return_t po_append(struct mount_options *, char *);
po_found_t po_contains(struct mount_options *, char *);
char * po_get(struct mount_options *, char *);
po_return_t po_append(struct mount_options *, char *);
po_found_t po_contains(struct mount_options *, char *);
char * po_get(struct mount_options *, char *);