Research V4 release

[unix-history] / sys / ken / rdwri.c

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

readi(ip)
struct inode *ip;
{
       int *bp;
       int dn, bn, on;
       int n, i;
       char *cp;

       if(u.u_count == 0)
               return;
       ip->i_flag =| IACC;
       if((ip->i_mode&IFMT) == IFCHR) {
               (*cdevsw[ip->i_addr[0].d_major].d_read)(ip->i_addr[0]);
               return;
       }

loop:
       bn = ldiv(u.u_offset[0], u.u_offset[1], 512);
       on = lrem(u.u_offset[0], u.u_offset[1], 512);
       n = min(512-on, u.u_count);
       if((ip->i_mode&IFMT) != IFBLK) {
               dn = dpcmp(ip->i_size0, ip->i_size1,
                       u.u_offset[0], u.u_offset[1]);
               if(dn <= 0)
                       return;
               n = min(n, dn);
               if ((bn = bmap(ip, bn)) == 0)
                       return;
               dn = ip->i_dev;
       } else
               dn = ip->i_addr[0];
       bp = bread(dn, bn);
       cp = bp->b_addr + on;
       if(u.u_segflg==0 && (n&1)==0 && (on&1)==0 && (u.u_base&1)==0) {
               if(copyout(cp, u.u_base, n))
                       u.u_error = EFAULT;
               u.u_base =+ n;
               goto incr;
       } else
       if(u.u_segflg != 0) {
               for(i=0; i<n; i++) {
                       *u.u_base = *cp;
                       u.u_base++;
                       cp++;
               }

       incr:
               dpadd(u.u_offset, n);
               u.u_count =- n;
       } else
       for(i=0; i<n; i++)
               if(passc(*cp++) < 0)
                       break;
       brelse(bp);
       if(u.u_error==0 && u.u_count!=0)
               goto loop;
}

writei(ip)
struct inode *ip;
{
       int *bp;
       int dn, bn, on;
       int n, i;
       char *cp;

       if(u.u_count == 0)
               return;
       ip->i_flag =| IACC;
       if((ip->i_mode&IFMT) == IFCHR) {
               (*cdevsw[ip->i_addr[0].d_major].d_write)(ip->i_addr[0]);
               return;
       }

loop:
       bn = ldiv(u.u_offset[0], u.u_offset[1], 512);
       on = lrem(u.u_offset[0], u.u_offset[1], 512);
       n = min(512-on, u.u_count);
       if((ip->i_mode&IFMT) != IFBLK) {
               if ((bn = bmap(ip, bn)) == 0)
                       return;
               dn = ip->i_dev;
       } else
               dn = ip->i_addr[0];
       if(n == 512) 
               bp = getblk(dn, bn); else
               bp = bread(dn, bn);
       cp = bp->b_addr + on;
       if(u.u_segflg==0 && (n&1)==0 && (on&1)==0 && (u.u_base&1)==0) {
               if(copyin(u.u_base, cp, n))
                       u.u_error = EFAULT;
               u.u_base =+ n;
               goto incr;
       } else
       if(u.u_segflg != 0) {
               for(i=0; i<n; i++) {
                       *cp = *u.u_base;
                       cp++;
                       u.u_base++;
               }

       incr:
               dpadd(u.u_offset, n);
               u.u_count =- n;
       } else
       for(i=0; i<n; i++)
               if(cpass(cp++) < 0)
                       break;
       if(lrem(u.u_offset[0], u.u_offset[1], 512) == 0)
               bawrite(bp); else
               bdwrite(bp);
       if(dpcmp(ip->i_size0, ip->i_size1,
         u.u_offset[0], u.u_offset[1]) < 0 &&
         (ip->i_mode&(IFBLK&IFCHR)) == 0) {
               ip->i_size0 = u.u_offset[0];
               ip->i_size1 = u.u_offset[1];
       }
       ip->i_flag =| IUPD;
       if(u.u_error==0 && u.u_count!=0)
               goto loop;
}

max(a, b)
char *a, *b;
{

       if(a > b)
               return(a);
       return(b);
}

min(a, b)
char *a, *b;
{

       if(a < b)
               return(a);
       return(b);
}