symbolic links

[unix-history] / usr / src / sys / kern / vfs_syscalls.c

diff --git a/usr/src/sys/kern/vfs_syscalls.c b/usr/src/sys/kern/vfs_syscalls.c
index 0c4e494..944dc66 100644 (file)
--- a/usr/src/sys/kern/vfs_syscalls.c
+++ b/usr/src/sys/kern/vfs_syscalls.c
@@ -1,4 +1,4 @@
-/*     vfs_syscalls.c  4.14    81/11/16        */
+/*     vfs_syscalls.c  4.18    82/02/27        */

 
 #include "../h/param.h"
 #include "../h/systm.h"
 
 #include "../h/param.h"
 #include "../h/systm.h"


@@ -39,7 +39,7 @@ fstat()
 }
 
 /*
 }
 
 /*

- * Stat system call.
+ * Stat system call.  This version does not follow links.

  */
 stat()
 {
  */
 stat()
 {


@@ -50,13 +50,32 @@ stat()
        } *uap;
 
        uap = (struct a *)u.u_ap;
        } *uap;
 
        uap = (struct a *)u.u_ap;

-       ip = namei(uchar, 0);
+       ip = namei(uchar, 0, 0);

        if (ip == NULL)
                return;
        stat1(ip, uap->sb);
        iput(ip);
 }
 
        if (ip == NULL)
                return;
        stat1(ip, uap->sb);
        iput(ip);
 }
 

+/*
+ * Lstat system call.  This version does follow links.
+ */
+lstat()
+{
+       register struct inode *ip;
+       register struct a {
+               char    *fname;
+               struct stat *sb;
+       } *uap;
+
+       uap = (struct a *)u.u_ap;
+       ip = namei(uchar, 0, 1);
+       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.
 /*
  * The basic routine for fstat and stat:
  * get the inode and pass appropriate parts back.


@@ -82,7 +101,7 @@ stat1(ip, ub)
        ds.st_rdev = (dev_t)ip->i_un.i_rdev;
        ds.st_size = ip->i_size;
        /*
        ds.st_rdev = (dev_t)ip->i_un.i_rdev;
        ds.st_size = ip->i_size;
        /*

-        * Next the dates in the disk
+        * next the dates in the disk

         */
        bp = bread(ip->i_dev, itod(ip->i_number));
        dp = bp->b_un.b_dino;
         */
        bp = bread(ip->i_dev, itod(ip->i_number));
        dp = bp->b_un.b_dino;


@@ -96,7 +115,79 @@ stat1(ip, ub)
 }
 
 /*
 }
 
 /*

- * Dup system call.
+ * Return target name of a symbolic link
+ */
+readlink()
+{
+       register struct inode *ip;
+       register struct a {
+               char    *name;
+               char    *buf;
+               int     count;
+       } *uap;
+
+       ip = namei(uchar, 0, 0);
+       if (ip == NULL)
+               return;
+       if ((ip->i_mode&IFMT) != IFLNK) {
+               u.u_error = ENXIO;
+               goto out;
+       }
+       uap = (struct a *)u.u_ap;
+       u.u_offset = 0;
+       u.u_base = uap->buf;
+       u.u_count = uap->count;
+       u.u_segflg = 0;
+       readi(ip);
+out:
+       iput(ip);
+       u.u_r.r_val1 = uap->count - u.u_count;
+}
+
+/*
+ * symlink -- make a symbolic link
+ */
+symlink()
+{
+       register struct a {
+               char    *target;
+               char    *linkname;
+       } *uap;
+       register struct inode *ip;
+       register char *tp;
+       register c, nc;
+
+       uap = (struct a *)u.u_ap;
+       tp = uap->target;
+       nc = 0;
+       while (c = fubyte(tp)) {
+               if (c < 0) {
+                       u.u_error = EFAULT;
+                       return;
+               }
+               tp++;
+               nc++;
+       }
+       u.u_dirp = uap->linkname;
+       ip = namei(uchar, 1, 0);
+       if (ip) {
+               iput(ip);
+               u.u_error = EEXIST;
+               return;
+       }
+       ip = maknode(IFLNK | 0777);
+       if (ip == NULL)
+               return;
+       u.u_base = uap->target;
+       u.u_count = nc;
+       u.u_offset = 0;
+       u.u_segflg = 0;
+       writei(ip);
+       iput(ip);
+}
+
+/*
+ * the dup system call.

  */
 dup()
 {
  */
 dup()
 {


@@ -126,7 +217,9 @@ dup()
        }
        if (i != uap->fdes) {
                if (u.u_ofile[i]!=NULL)
        }
        if (i != uap->fdes) {
                if (u.u_ofile[i]!=NULL)

-                       closef(u.u_ofile[i]);
+                       closef(u.u_ofile[i], 0);
+               if (u.u_error)
+                       return;

                u.u_ofile[i] = fp;
                fp->f_count++;
        }
                u.u_ofile[i] = fp;
                fp->f_count++;
        }


@@ -155,7 +248,7 @@ smount()
        if (u.u_error)
                return;
        u.u_dirp = (caddr_t)uap->freg;
        if (u.u_error)
                return;
        u.u_dirp = (caddr_t)uap->freg;

-       ip = namei(uchar, 0);
+       ip = namei(uchar, 0, 1);

        if (ip == NULL)
                return;
        if (ip->i_count!=1 || (ip->i_mode&IFMT) != IFDIR)
        if (ip == NULL)
                return;
        if (ip->i_count!=1 || (ip->i_mode&IFMT) != IFDIR)


@@ -224,7 +317,7 @@ sumount()
        if (u.u_error)
                return;
        xumount(dev);   /* remove unused sticky files from text table */
        if (u.u_error)
                return;
        xumount(dev);   /* remove unused sticky files from text table */

-       update();
+       update(0);

        for (mp = &mount[0]; mp < &mount[NMOUNT]; mp++)
                if (mp->m_bufp != NULL && dev == mp->m_dev)
                        goto found;
        for (mp = &mount[0]; mp < &mount[NMOUNT]; mp++)
                if (mp->m_bufp != NULL && dev == mp->m_dev)
                        goto found;


@@ -270,7 +363,7 @@ getmdev()
 
        if (!suser())
                return(NODEV);
 
        if (!suser())
                return(NODEV);

-       ip = namei(uchar, 0);
+       ip = namei(uchar, 0, 1);

        if (ip == NULL)
                return(NODEV);
        if ((ip->i_mode&IFMT) != IFBLK)
        if (ip == NULL)
                return(NODEV);
        if ((ip->i_mode&IFMT) != IFBLK)