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[unix-history] / usr / sys / ken / sys3.c

#
/*
*/

#include "../param.h"
#include "../systm.h"
#include "../reg.h"
#include "../buf.h"
#include "../filsys.h"
#include "../user.h"
#include "../inode.h"
#include "../file.h"
#include "../conf.h"

/*
* the fstat system call.
*/
fstat()
{
       register *fp;

       fp = getf(u.u_ar0[R0]);
       if(fp == NULL)
               return;
       stat1(fp->f_inode, u.u_arg[0]);
}

/*
* the stat system call.
*/
stat()
{
       register ip;
       extern uchar;

       ip = namei(&uchar, 0);
       if(ip == NULL)
               return;
       stat1(ip, u.u_arg[1]);
       iput(ip);
}

/*
* The basic routine for fstat and stat:
* get the inode and pass appropriate parts back.
*/
stat1(ip, ub)
int *ip;
{
       register i, *bp, *cp;

       iupdat(ip, time);
       bp = bread(ip->i_dev, ldiv(ip->i_number+31, 16));
       cp = bp->b_addr + 32*lrem(ip->i_number+31, 16) + 24;
       ip = &(ip->i_dev);
       for(i=0; i<14; i++) {
               suword(ub, *ip++);
               ub =+ 2;
       }
       for(i=0; i<4; i++) {
               suword(ub, *cp++);
               ub =+ 2;
       }
       brelse(bp);
}

/*
* the dup system call.
*/
dup()
{
       register i, *fp;

       fp = getf(u.u_ar0[R0]);
       if(fp == NULL)
               return;
       if ((i = ufalloc()) < 0)
               return;
       u.u_ofile[i] = fp;
       fp->f_count++;
}

/*
* the mount system call.
*/
smount()
{
       int d;
       register *ip;
       register struct mount *mp, *smp;
       extern uchar;

       d = getmdev();
       if(u.u_error)
               return;
       u.u_dirp = u.u_arg[1];
       ip = namei(&uchar, 0);
       if(ip == NULL)
               return;
       if(ip->i_count!=1 || (ip->i_mode&(IFBLK&IFCHR))!=0)
               goto out;
       smp = NULL;
       for(mp = &mount[0]; mp < &mount[NMOUNT]; mp++) {
               if(mp->m_bufp != NULL) {
                       if(d == mp->m_dev)
                               goto out;
               } else
               if(smp == NULL)
                       smp = mp;
       }
       if(smp == NULL)
               goto out;
       (*bdevsw[d.d_major].d_open)(d, !u.u_arg[2]);
       if(u.u_error)
               goto out;
       mp = bread(d, 1);
       if(u.u_error) {
               brelse(mp);
               goto out1;
       }
       smp->m_inodp = ip;
       smp->m_dev = d;
       smp->m_bufp = getblk(NODEV);
       bcopy(mp->b_addr, smp->m_bufp->b_addr, 256);
       smp = smp->m_bufp->b_addr;
       smp->s_ilock = 0;
       smp->s_flock = 0;
       smp->s_ronly = u.u_arg[2] & 1;
       brelse(mp);
       ip->i_flag =| IMOUNT;
       prele(ip);
       return;

out:
       u.u_error = EBUSY;
out1:
       iput(ip);
}

/*
* the umount system call.
*/
sumount()
{
       int d;
       register struct inode *ip;
       register struct mount *mp;

       update();
       d = getmdev();
       if(u.u_error)
               return;
       for(mp = &mount[0]; mp < &mount[NMOUNT]; mp++)
               if(mp->m_bufp!=NULL && d==mp->m_dev)
                       goto found;
       u.u_error = EINVAL;
       return;

found:
       for(ip = &inode[0]; ip < &inode[NINODE]; ip++)
               if(ip->i_number!=0 && d==ip->i_dev) {
                       u.u_error = EBUSY;
                       return;
               }
       (*bdevsw[d.d_major].d_close)(d, 0);
       ip = mp->m_inodp;
       ip->i_flag =& ~IMOUNT;
       iput(ip);
       ip = mp->m_bufp;
       mp->m_bufp = NULL;
       brelse(ip);
}

/*
* Common code for mount and umount.
* Check that the user's argument is a reasonable
* thing on which to mount, and return the device number if so.
*/
getmdev()
{
       register d, *ip;
       extern uchar;

       ip = namei(&uchar, 0);
       if(ip == NULL)
               return;
       if((ip->i_mode&IFMT) != IFBLK)
               u.u_error = ENOTBLK;
       d = ip->i_addr[0];
       if(ip->i_addr[0].d_major >= nblkdev)
               u.u_error = ENXIO;
       iput(ip);
       return(d);
}