file system update orderings

[unix-history] / usr / src / sys / ufs / ffs / ufs_vnops.c

/*      ufs_vnops.c     3.5     %G%     */

#include "../h/param.h"
#include "../h/systm.h"
#include "../h/mount.h"
#include "../h/ino.h"
#include "../h/reg.h"
#include "../h/buf.h"
#include "../h/filsys.h"
#include "../h/dir.h"
#include "../h/user.h"
#include "../h/inode.h"
#include "../h/file.h"
#include "../h/conf.h"
#include "../h/stat.h"
#include "../h/inline.h"

/*
* the fstat system call.
*/
fstat()
{
       register struct file *fp;
       register struct a {
               int     fdes;
               struct stat *sb;
       } *uap;

       uap = (struct a *)u.u_ap;
       fp = getf(uap->fdes);
       if(fp == NULL)
               return;
       stat1(fp->f_inode, uap->sb, fp->f_flag&FPIPE? fp->f_un.f_offset: 0);
}

/*
* the stat system call.
*/
stat()
{
       register struct inode *ip;
       register struct a {
               char    *fname;
               struct stat *sb;
       } *uap;

       uap = (struct a *)u.u_ap;
       ip = namei(uchar, 0);
       if(ip == NULL)
               return;
       stat1(ip, uap->sb, (off_t)0);
       iput(ip);
}

/*
* The basic routine for fstat and stat:
* get the inode and pass appropriate parts back.
*/
stat1(ip, ub, pipeadj)
register struct inode *ip;
struct stat *ub;
off_t pipeadj;
{
       register struct dinode *dp;
       register struct buf *bp;
       struct stat ds;

       IUPDAT(ip, &time, &time, 0);
       /*
        * first copy from inode table
        */
       ds.st_dev = ip->i_dev;
       ds.st_ino = ip->i_number;
       ds.st_mode = ip->i_mode;
       ds.st_nlink = ip->i_nlink;
       ds.st_uid = ip->i_uid;
       ds.st_gid = ip->i_gid;
       ds.st_rdev = (dev_t)ip->i_un.i_rdev;
       ds.st_size = ip->i_size - pipeadj;
       /*
        * next the dates in the disk
        */
       bp = bread(ip->i_dev, itod(ip->i_number));
       dp = bp->b_un.b_dino;
       dp += itoo(ip->i_number);
       ds.st_atime = dp->di_atime;
       ds.st_mtime = dp->di_mtime;
       ds.st_ctime = dp->di_ctime;
       brelse(bp);
       if (copyout((caddr_t)&ds, (caddr_t)ub, sizeof(ds)) < 0)
               u.u_error = EFAULT;
}

/*
* the dup system call.
*/
dup()
{
       register struct file *fp;
       register struct a {
               int     fdes;
               int     fdes2;
       } *uap;
       register i, m;

       uap = (struct a *)u.u_ap;
       m = uap->fdes & ~077;
       uap->fdes &= 077;
       fp = getf(uap->fdes);
       if(fp == NULL)
               return;
       if ((m&0100) == 0) {
               if ((i = ufalloc()) < 0)
                       return;
       } else {
               i = uap->fdes2;
               if (i<0 || i>=NOFILE) {
                       u.u_error = EBADF;
                       return;
               }
               if (u.u_vrpages[i]) {
                       u.u_error = ETXTBSY;
                       return;
               }
               u.u_r.r_val1 = i;
       }
       if (i!=uap->fdes) {
               if (u.u_ofile[i]!=NULL)
                       closef(u.u_ofile[i]);
               u.u_ofile[i] = fp;
               fp->f_count++;
       }
}

/*
* the mount system call.
*/
smount()
{
       dev_t dev;
       register struct inode *ip;
       register struct mount *mp;
       struct mount *smp;
       register struct filsys *fp;
       struct buf *bp;
       register struct a {
               char    *fspec;
               char    *freg;
               int     ronly;
       } *uap;

       uap = (struct a *)u.u_ap;
       dev = getmdev();
       if(u.u_error)
               return;
       u.u_dirp = (caddr_t)uap->freg;
       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(dev == mp->m_dev)
                               goto out;
               } else
               if(smp == NULL)
                       smp = mp;
       }
       mp = smp;
       if(mp == NULL)
               goto out;
       (*bdevsw[major(dev)].d_open)(dev, !uap->ronly);
       if(u.u_error)
               goto out;
       bp = bread(dev, SUPERB);
       if(u.u_error) {
               brelse(bp);
               goto out1;
       }
       mp->m_inodp = ip;
       mp->m_dev = dev;
       mp->m_bufp = geteblk();
       bcopy((caddr_t)bp->b_un.b_addr, mp->m_bufp->b_un.b_addr, BSIZE);
       fp = mp->m_bufp->b_un.b_filsys;
       fp->s_ilock = 0;
       fp->s_flock = 0;
       fp->s_ronly = uap->ronly & 1;
       fp->s_nbehind = 0;
       fp->s_lasti = 1;
       brelse(bp);
       ip->i_flag |= IMOUNT;
       prele(ip);
       return;

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

/*
* the umount system call.
*/
sumount()
{
       dev_t dev;
       register struct inode *ip;
       register struct mount *mp;
       struct buf *bp;
       register struct a {
               char    *fspec;
       };

       dev = getmdev();
       if(u.u_error)
               return;
       xumount(dev);   /* remove unused sticky files from text table */
       update();
       for(mp = &mount[0]; mp < &mount[NMOUNT]; mp++)
               if(mp->m_bufp != NULL && dev == mp->m_dev)
                       goto found;
       u.u_error = EINVAL;
       return;

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

/*
* 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.
*/
dev_t
getmdev()
{
       dev_t dev;
       register struct inode *ip;

#ifdef UCB
       if (!suser())
               return(NODEV);
#endif
       ip = namei(uchar, 0);
       if(ip == NULL)
               return(NODEV);
       if((ip->i_mode&IFMT) != IFBLK)
               u.u_error = ENOTBLK;
       dev = (dev_t)ip->i_un.i_rdev;
       if(major(dev) >= nblkdev)
               u.u_error = ENXIO;
       iput(ip);
       return(dev);
}