int major;
int blkmaj;
chrtoblk(dev)	dev_t dev;{	int major;		if (major(dev) >= nchrdev ||	    major(dev) > sizeof(chrtoblktbl)/sizeof(chrtoblktbl[0]))		return (NODEV);	blkmaj = chrtoblktbl[major(dev)];	if (blkmaj == NODEV)		return (NODEV);	return (makedev(blkmaj, minor(dev)));}