V4/nsys/ken/subr.c

#include "/sys/nsys/param.h"
#include "/sys/nsys/conf.h"
#include "/sys/nsys/inode.h"
#include "/sys/nsys/user.h"
#include "/sys/nsys/buf.h"

bmap(ip, bn)
struct inode *ip;
int bn;
{
	int *bp, *nbp;
	int nb, d;
	int *bap, i;

	d = ip->i_dev;

	if (bn & ~03777) {
		u.u_error = EFBIG;
		return(0);
	}
	if((ip->i_mode&ILARG) == 0) {

		/*
		 * small file algorithm
		 */

		if((bn & ~7) != 0) {

			/*
			 * bad part:
			 * convert small to large
			 */

			if ((bp = alloc(d)) == NULL)
				return(0);
			bap = bp->b_addr;
			for(i=0; i<8; i++) {
				*bap++ = ip->i_addr[i];
				ip->i_addr[i] = 0;
			}
			ip->i_addr[0] = bp->b_blkno;
			bwrite(bp);
			ip->i_mode =| ILARG;
			goto large;
		}
		nb = ip->i_addr[bn];
		if(nb == 0 && (bp = alloc(d)) != NULL) {
			bdwrite(bp);
			nb = bp->b_blkno;
			ip->i_addr[bn] = nb;
			ip->i_flag =| IUPD;
		}
		return(nb);
	}

	/*
	 * large file algorithm
	 */

    large:
	i = bn>>8;
	if((nb=ip->i_addr[i]) == 0) {
		ip->i_flag =| IUPD;
		if ((bp = alloc(d)) == NULL)
			return(0);
		nb = bp->b_blkno;
		ip->i_addr[i] = nb;
	} else
		bp = bread(d, nb);
	bap = bp->b_addr;
	i = bn & 0377;
	if((nb=bap[i]) == 0 && (nbp = alloc(d)) != NULL) {
		nb = nbp->b_blkno;
		bap[i] = nb;
		bdwrite(nbp);
		bwrite(bp);
	} else
		brelse(bp);
	return(nb);
}

passc(c)
char c;
{

	if(u.u_segflg)
		*u.u_base = c; else
		if(subyte(u.u_base, c) < 0) {
			u.u_error = EFAULT;
			return(-1);
		}
	u.u_count--;
	if(++u.u_offset[1] == 0)
		u.u_offset[0]++;
	u.u_base++;
	return(u.u_count == 0? -1: 0);
}

cpass(cp)
char *cp;
{
	int c;

	if(u.u_count == 0)
		return(-1);
	if(u.u_segflg)
		*cp = *u.u_base; else
		if((c=fubyte(u.u_base)) < 0) {
			u.u_error = EFAULT;
			return(-1);
		} else
			*cp = c;
	u.u_count--;
	if(++u.u_offset[1] == 0)
		u.u_offset[0]++;
	u.u_base++;
	return(0);
}

nodev()
{

	u.u_error = ENODEV;
}

nulldev()
{
}