readvtoc
if ((slice = readvtoc(fd, device, &vtdata)) >= 0) {
if (readvtoc(fd, device, &vtdata) < 0)
static int readvtoc(int fd, char *name, struct extvtoc *vtoc);
if (readvtoc() != VTOC_OK) {
static int readvtoc(void);
if ((idx = readvtoc(fd, name, &vtoc)) == VT_ENOTSUP) {
static int readvtoc(int, char *, struct extvtoc *);