sdev_get_vtor
vtor = (int (*)(struct sdev_node *))sdev_get_vtor(ddv);
vtor = (int (*)(struct sdev_node *))sdev_get_vtor(ddv);
vtor = (int (*)(struct sdev_node *))sdev_get_vtor(ddv);
vtor = (int (*)(struct sdev_node *))sdev_get_vtor(ddv);
extern void *sdev_get_vtor(struct sdev_node *dv);
extern void *sdev_get_vtor(struct sdev_node *dv);