X-Git-Url: https://git.subgeniuskitty.com/unix-history/.git/blobdiff_plain/f3e6400f0c4441d0a3d6d165792f3faf4a020976..81552f0f5904ea22ac22667d377d623a641b663c:/usr/src/sys/ufs/lfs/lfs_vnops.c

diff --git a/usr/src/sys/ufs/lfs/lfs_vnops.c b/usr/src/sys/ufs/lfs/lfs_vnops.c
index 9bcc790240..e91077154a 100644
--- a/usr/src/sys/ufs/lfs/lfs_vnops.c
+++ b/usr/src/sys/ufs/lfs/lfs_vnops.c
@@ -1,23 +1,38 @@
-/*	lfs_vnops.c	4.27	82/06/25	*/
+/*	lfs_vnops.c	4.58	83/05/28	*/
 
 #include "../h/param.h"
 #include "../h/systm.h"
 #include "../h/dir.h"
 #include "../h/user.h"
+#include "../h/kernel.h"
 #include "../h/file.h"
 #include "../h/stat.h"
 #include "../h/inode.h"
 #include "../h/fs.h"
 #include "../h/buf.h"
 #include "../h/proc.h"
-#include "../h/inline.h"
+#include "../h/quota.h"
+#include "../h/uio.h"
+#include "../h/socket.h"
+#include "../h/socketvar.h"
+#include "../h/nami.h"
+#include "../h/mount.h"
 
+extern	struct fileops inodeops;
+struct	file *getinode();
+
+/*
+ * Change current working directory (``.'').
+ */
 chdir()
 {
 
 	chdirec(&u.u_cdir);
 }
 
+/*
+ * Change notion of root (``/'') directory.
+ */
 chroot()
 {
 
@@ -25,22 +40,25 @@ chroot()
 		chdirec(&u.u_rdir);
 }
 
+/*
+ * Common routine for chroot and chdir.
+ */
 chdirec(ipp)
-register struct inode **ipp;
+	register struct inode **ipp;
 {
 	register struct inode *ip;
 	struct a {
 		char	*fname;
 	};
 
-	ip = namei(uchar, 0, 1);
-	if(ip == NULL)
+	ip = namei(uchar, LOOKUP, 1);
+	if (ip == NULL)
 		return;
-	if((ip->i_mode&IFMT) != IFDIR) {
+	if ((ip->i_mode&IFMT) != IFDIR) {
 		u.u_error = ENOTDIR;
 		goto bad;
 	}
-	if(access(ip, IEXEC))
+	if (access(ip, IEXEC))
 		goto bad;
 	iunlock(ip);
 	if (*ipp)
@@ -57,17 +75,13 @@ bad:
  */
 open()
 {
-	register struct inode *ip;
-	register struct a {
+	struct a {
 		char	*fname;
-		int	rwmode;
-	} *uap;
+		int	mode;
+		int	crtmode;
+	} *uap = (struct a *) u.u_ap;
 
-	uap = (struct a *)u.u_ap;
-	ip = namei(uchar, 0, 1);
-	if (ip == NULL)
-		return;
-	open1(ip, ++uap->rwmode, 0);
+	copen(uap->mode-FOPEN, uap->crtmode);
 }
 
 /*
@@ -75,23 +89,12 @@ open()
  */
 creat()
 {
-	register struct inode *ip;
-	register struct a {
+	struct a {
 		char	*fname;
 		int	fmode;
-	} *uap;
+	} *uap = (struct a *)u.u_ap;
 
-	uap = (struct a *)u.u_ap;
-	ip = namei(uchar, 1, 1);
-	if (ip == NULL) {
-		if (u.u_error)
-			return;
-		ip = maknode(uap->fmode&07777&(~ISVTX));
-		if (ip==NULL)
-			return;
-		open1(ip, FWRITE, 2);
-	} else
-		open1(ip, FWRITE, 1);
+	copen(FWRITE|FCREAT|FTRUNC, uap->fmode);
 }
 
 /*
@@ -99,41 +102,88 @@ creat()
  * Check permissions, allocate an open file structure,
  * and call the device open routine if any.
  */
-open1(ip, mode, trf)
-	register struct inode *ip;
-	register mode;
+copen(mode, arg)
+	register int mode;
+	int arg;
 {
+	register struct inode *ip;
 	register struct file *fp;
 	int i;
 
-	if (trf != 2) {
+#ifdef notdef
+	if ((mode&(FREAD|FWRITE)) == 0) {
+		u.u_error = EINVAL;
+		return;
+	}
+#endif
+	if (mode&FCREAT) {
+		ip = namei(uchar, CREATE, 1);
+		if (ip == NULL) {
+			if (u.u_error)
+				return;
+			ip = maknode(arg&07777&(~ISVTX));
+			if (ip == NULL)
+				return;
+			mode &= ~FTRUNC;
+		} else {
+			if (mode&FEXCL) {
+				u.u_error = EEXIST;
+				iput(ip);
+				return;
+			}
+			mode &= ~FCREAT;
+		}
+	} else {
+		ip = namei(uchar, LOOKUP, 1);
+		if (ip == NULL)
+			return;
+	}
+	if ((ip->i_mode & IFMT) == IFSOCK) {
+		u.u_error = EOPNOTSUPP;
+		goto bad;
+	}
+	if ((mode&FCREAT) == 0) {
 		if (mode&FREAD)
-			(void) access(ip, IREAD);
+			if (access(ip, IREAD))
+				goto bad;
 		if (mode&FWRITE) {
-			(void) access(ip, IWRITE);
-			if ((ip->i_mode&IFMT) == IFDIR)
+			if (access(ip, IWRITE))
+				goto bad;
+			if ((ip->i_mode&IFMT) == IFDIR) {
 				u.u_error = EISDIR;
+				goto bad;
+			}
 		}
 	}
-	if (u.u_error) {
-		iput(ip);
-		return;
-	}
-	if (trf == 1)
-		itrunc(ip);
+	fp = falloc();
+	if (fp == NULL)
+		goto bad;
+	if (mode&FTRUNC)
+		itrunc(ip, (u_long)0);
 	iunlock(ip);
-	if ((fp = falloc()) == NULL)
-		goto out;
-	fp->f_flag = mode&(FREAD|FWRITE);
+	fp->f_flag = mode&FMASK;
+	fp->f_type = DTYPE_INODE;
+	fp->f_ops = &inodeops;
+	fp->f_data = (caddr_t)ip;
 	i = u.u_r.r_val1;
-	fp->f_inode = ip;
-	openi(ip, mode&(FREAD|FWRITE));
+#ifdef notdef
+	if (setjmp(&u.u_qsave)) {
+		if (u.u_error == 0)
+			u.u_error = EINTR;
+		u.u_ofile[i] = NULL;
+		closef(fp);
+		return;
+	}
+#endif
+	u.u_error = openi(ip, mode);
 	if (u.u_error == 0)
 		return;
 	u.u_ofile[i] = NULL;
 	fp->f_count--;
-out:
 	irele(ip);
+	return;
+bad:
+	iput(ip);
 }
 
 /*
@@ -149,25 +199,30 @@ mknod()
 	} *uap;
 
 	uap = (struct a *)u.u_ap;
-	if (suser()) {
-		ip = namei(uchar, 1, 0);
-		if (ip != NULL) {
-			u.u_error = EEXIST;
-			goto out;
-		}
+	if (!suser())
+		return;
+	ip = namei(uchar, CREATE, 0);
+	if (ip != NULL) {
+		u.u_error = EEXIST;
+		goto out;
 	}
 	if (u.u_error)
 		return;
 	ip = maknode(uap->fmode);
 	if (ip == NULL)
 		return;
-	if (uap->dev) {
-		/*
-		 * Want to be able to use this to make badblock
-		 * inodes, so don't truncate the dev number.
-		 */
-		ip->i_rdev = uap->dev;
-		ip->i_flag |= IACC|IUPD|ICHG;
+	switch (ip->i_mode & IFMT) {
+
+	case IFCHR:
+	case IFBLK:
+		if (uap->dev) {
+			/*
+			 * Want to be able to use this to make badblock
+			 * inodes, so don't truncate the dev number.
+			 */
+			ip->i_rdev = uap->dev;
+			ip->i_flag |= IACC|IUPD|ICHG;
+		}
 	}
 
 out:
@@ -186,17 +241,19 @@ link()
 	} *uap;
 
 	uap = (struct a *)u.u_ap;
-	ip = namei(uchar, 0, 1);    /* well, this routine is doomed anyhow */
+	ip = namei(uchar, LOOKUP, 1); /* well, this routine is doomed anyhow */
 	if (ip == NULL)
 		return;
-	if ((ip->i_mode&IFMT)==IFDIR && !suser())
-		goto out1;
+	if ((ip->i_mode&IFMT) == IFDIR && !suser()) {
+		iput(ip);
+		return;
+	}
 	ip->i_nlink++;
 	ip->i_flag |= ICHG;
 	iupdat(ip, &time, &time, 1);
 	iunlock(ip);
 	u.u_dirp = (caddr_t)uap->linkname;
-	xp = namei(uchar, 1, 0);
+	xp = namei(uchar, CREATE, 0);
 	if (xp != NULL) {
 		u.u_error = EEXIST;
 		iput(xp);
@@ -209,13 +266,12 @@ link()
 		u.u_error = EXDEV;
 		goto out;
 	}
-	wdir(ip);
+	u.u_error = direnter(ip);
 out:
 	if (u.u_error) {
 		ip->i_nlink--;
 		ip->i_flag |= ICHG;
 	}
-out1:
 	irele(ip);
 }
 
@@ -244,7 +300,7 @@ symlink()
 		nc++;
 	}
 	u.u_dirp = uap->linkname;
-	ip = namei(uchar, 1, 0);
+	ip = namei(uchar, CREATE, 0);
 	if (ip) {
 		iput(ip);
 		u.u_error = EEXIST;
@@ -255,11 +311,8 @@ symlink()
 	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);
+	u.u_error = rdwri(UIO_WRITE, ip, uap->target, nc, 0, 0, (int *)0);
+	/* handle u.u_error != 0 */
 	iput(ip);
 }
 
@@ -270,109 +323,58 @@ symlink()
  */
 unlink()
 {
-	register struct inode *ip, *pp;
 	struct a {
 		char	*fname;
 	};
-	struct fs *fs;
-	struct buf *bp;
-	int lbn, bn, base;
-	int unlinkingdot = 0;
+	register struct inode *ip, *dp;
 
-	pp = namei(uchar, 2, 0);
-	if(pp == NULL)
+	ip = namei(uchar, DELETE | LOCKPARENT, 0);
+	if (ip == NULL)
 		return;
-	/*
-	 * Check for unlink(".")
-	 * to avoid hanging on the iget
-	 */
-	if (pp->i_number == u.u_dent.d_ino) {
-		ip = pp;
-		ip->i_count++;
-		unlinkingdot++;
-	} else
-		ip = iget(pp->i_dev, pp->i_fs, u.u_dent.d_ino);
-	if(ip == NULL)
-		goto out1;
-	if((ip->i_mode&IFMT)==IFDIR && !suser())
+	dp = u.u_pdir;
+	if ((ip->i_mode&IFMT) == IFDIR && !suser())
 		goto out;
 	/*
 	 * Don't unlink a mounted file.
 	 */
-	if (ip->i_dev != pp->i_dev) {
+	if (ip->i_dev != dp->i_dev) {
 		u.u_error = EBUSY;
 		goto out;
 	}
 	if (ip->i_flag&ITEXT)
 		xrele(ip);	/* try once to free text */
-/*
-	if ((ip->i_flag&ITEXT) && ip->i_nlink==1) {
- 		u.u_error = ETXTBSY;
-		goto out;
-	}
-*/
-	if (u.u_count == 0) {
-		/*
-		 * first entry in block, so set d_ino to zero.
-		 */
-		u.u_base = (caddr_t)&u.u_dent;
-		u.u_count = DIRSIZ(&u.u_dent);
-		u.u_dent.d_ino = 0;
-		writei(pp);
-	} else {
-		/*
-		 * updating preceeding entry to skip over current entry.
-		 */
-		fs = pp->i_fs;
-		lbn = lblkno(fs, u.u_offset);
-		base = blkoff(fs, u.u_offset);
-		bn = fsbtodb(fs, bmap(pp, lbn, B_WRITE, base + u.u_count));
-		bp = bread(pp->i_dev, bn, blksize(fs, pp, lbn));
-		if (bp->b_flags & B_ERROR) {
-			brelse(bp);
-			goto out;
-		}
-		((struct direct *)(bp->b_un.b_addr + base))->d_reclen +=
-		    u.u_dent.d_reclen;
-		bwrite(bp);
-		pp->i_flag |= IUPD|ICHG;
+	if (dirremove()) {
+		ip->i_nlink--;
+		ip->i_flag |= ICHG;
 	}
-	ip->i_nlink--;
-	ip->i_flag |= ICHG;
-
 out:
-	if (unlinkingdot)
+	if (dp == ip)
 		irele(ip);
 	else
 		iput(ip);
-out1:
-	iput(pp);
+	iput(dp);
 }
 
 /*
  * Seek system call
  */
-seek()
+lseek()
 {
 	register struct file *fp;
 	register struct a {
-		int	fdes;
+		int	fd;
 		off_t	off;
 		int	sbase;
 	} *uap;
 
 	uap = (struct a *)u.u_ap;
-	fp = getf(uap->fdes);
+	fp = getinode(uap->fd);
 	if (fp == NULL)
 		return;
-	if (fp->f_flag&FSOCKET) {
-		u.u_error = ESPIPE;
-		return;
-	}
-	if (uap->sbase == 1)
+	if (uap->sbase == L_INCR)
 		uap->off += fp->f_offset;
-	else if (uap->sbase == 2)
-		uap->off += fp->f_inode->i_size;
+	else if (uap->sbase == L_XTND)
+		uap->off += ((struct inode *)fp->f_data)->i_size;
 	fp->f_offset = uap->off;
 	u.u_r.r_off = uap->off;
 }
@@ -394,107 +396,56 @@ saccess()
 	svgid = u.u_gid;
 	u.u_uid = u.u_ruid;
 	u.u_gid = u.u_rgid;
-	ip = namei(uchar, 0, 1);
+	ip = namei(uchar, LOOKUP, 1);
 	if (ip != NULL) {
-		if (uap->fmode&(IREAD>>6))
-			(void) access(ip, IREAD);
-		if (uap->fmode&(IWRITE>>6))
-			(void) access(ip, IWRITE);
-		if (uap->fmode&(IEXEC>>6))
-			(void) access(ip, IEXEC);
+		if ((uap->fmode&R_OK) && access(ip, IREAD))
+			goto done;
+		if ((uap->fmode&W_OK) && access(ip, IWRITE))
+			goto done;
+		if ((uap->fmode&X_OK) && access(ip, IEXEC))
+			goto done;
+done:
 		iput(ip);
 	}
 	u.u_uid = svuid;
 	u.u_gid = svgid;
 }
 
-/*
- * 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;
-	if (fp->f_flag & FSOCKET)
-		u.u_error = sostat(fp->f_socket, uap->sb);
-	else
-		stat1(fp->f_inode, uap->sb);
-}
-
 /*
  * Stat system call.  This version follows links.
  */
 stat()
 {
-	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);
-	iput(ip);
+	stat1(1);
 }
 
 /*
  * Lstat system call.  This version does not follow links.
  */
 lstat()
+{
+
+	stat1(0);
+}
+
+stat1(follow)
+	int follow;
 {
 	register struct inode *ip;
 	register struct a {
 		char	*fname;
-		struct stat *sb;
+		struct stat *ub;
 	} *uap;
+	struct stat sb;
 
 	uap = (struct a *)u.u_ap;
-	ip = namei(uchar, 0, 0);
+	ip = namei(uchar, LOOKUP, follow);
 	if (ip == NULL)
 		return;
-	stat1(ip, uap->sb);
+	(void) statinode(ip, &sb);
 	iput(ip);
-}
-
-/*
- * The basic routine for fstat and stat:
- * get the inode and pass appropriate parts back.
- */
-stat1(ip, ub)
-	register struct inode *ip;
-	struct stat *ub;
-{
-	struct stat ds;
-
-	IUPDAT(ip, &time, &time, 0);
-	/*
-	 * 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_rdev;
-	ds.st_size = ip->i_size;
-	ds.st_atime = ip->i_atime;
-	ds.st_mtime = ip->i_mtime;
-	ds.st_ctime = ip->i_ctime;
-	ds.st_blksize = ip->i_fs->fs_bsize;
-	if (copyout((caddr_t)&ds, (caddr_t)ub, sizeof(ds)) < 0)
-		u.u_error = EFAULT;
+	u.u_error = copyout((caddr_t)&sb, (caddr_t)uap->ub, sizeof (sb));
 }
 
 /*
@@ -507,30 +458,29 @@ readlink()
 		char	*name;
 		char	*buf;
 		int	count;
-	} *uap;
+	} *uap = (struct a *)u.u_ap;
+	int resid;
 
-	ip = namei(uchar, 0, 0);
+	ip = namei(uchar, LOOKUP, 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);
+	u.u_error = rdwri(UIO_READ, ip, uap->buf, uap->count, 0, 0, &resid);
 out:
 	iput(ip);
-	u.u_r.r_val1 = uap->count - u.u_count;
+	u.u_r.r_val1 = uap->count - resid;
 }
 
+/*
+ * Change mode of a file given path name.
+ */
 chmod()
 {
-	register struct inode *ip;
-	register struct a {
+	struct inode *ip;
+	struct a {
 		char	*fname;
 		int	fmode;
 	} *uap;
@@ -538,20 +488,62 @@ chmod()
 	uap = (struct a *)u.u_ap;
 	if ((ip = owner(1)) == NULL)
 		return;
+	chmod1(ip, uap->fmode);
+	iput(ip);
+}
+
+/*
+ * Change mode of a file given a file descriptor.
+ */
+fchmod()
+{
+	struct a {
+		int	fd;
+		int	fmode;
+	} *uap;
+	register struct inode *ip;
+	register struct file *fp;
+
+	uap = (struct a *)u.u_ap;
+	fp = getinode(uap->fd);
+	if (fp == NULL)
+		return;
+	ip = (struct inode *)fp->f_data;
+	if (u.u_uid != ip->i_uid && !suser())
+		return;
+	ilock(ip);
+	chmod1(ip, uap->fmode);
+	iunlock(ip);
+}
+
+/*
+ * Change the mode on a file.
+ * Inode must be locked before calling.
+ */
+chmod1(ip, mode)
+	register struct inode *ip;
+	register int mode;
+{
+
 	ip->i_mode &= ~07777;
-	if (u.u_uid)
-		uap->fmode &= ~ISVTX;
-	ip->i_mode |= uap->fmode&07777;
+	if (u.u_uid) {
+		mode &= ~ISVTX;
+		if (!groupmember(ip->i_gid))
+			mode &= ~ISGID;
+	}
+	ip->i_mode |= mode&07777;
 	ip->i_flag |= ICHG;
 	if (ip->i_flag&ITEXT && (ip->i_mode&ISVTX)==0)
 		xrele(ip);
-	iput(ip);
 }
 
+/*
+ * Set ownership given a path name.
+ */
 chown()
 {
-	register struct inode *ip;
-	register struct a {
+	struct inode *ip;
+	struct a {
 		char	*fname;
 		int	uid;
 		int	gid;
@@ -560,41 +552,795 @@ chown()
 	uap = (struct a *)u.u_ap;
 	if (!suser() || (ip = owner(0)) == NULL)
 		return;
-	ip->i_uid = uap->uid;
-	ip->i_gid = uap->gid;
+	u.u_error = chown1(ip, uap->uid, uap->gid);
+	iput(ip);
+}
+
+/*
+ * Set ownership given a file descriptor.
+ */
+fchown()
+{
+	struct a {
+		int	fd;
+		int	uid;
+		int	gid;
+	} *uap;
+	register struct inode *ip;
+	register struct file *fp;
+
+	uap = (struct a *)u.u_ap;
+	fp = getinode(uap->fd);
+	if (fp == NULL)
+		return;
+	ip = (struct inode *)fp->f_data;
+	if (!suser())
+		return;
+	ilock(ip);
+	u.u_error = chown1(ip, uap->uid, uap->gid);
+	iunlock(ip);
+}
+
+/*
+ * Perform chown operation on inode ip;
+ * inode must be locked prior to call.
+ */
+chown1(ip, uid, gid)
+	register struct inode *ip;
+	int uid, gid;
+{
+#ifdef QUOTA
+	register long change;
+#endif
+
+	if (uid == -1)
+		uid = ip->i_uid;
+	if (gid == -1)
+		gid = ip->i_gid;
+#ifdef QUOTA
+	if (ip->i_uid != uid)		/* this just speeds things a little */
+		change = 0;
+	else
+		change = ip->i_blocks;
+	(void) chkdq(ip, -change, 1);
+	(void) chkiq(ip->i_dev, ip, ip->i_uid, 1);
+	dqrele(ip->i_dquot);
+#endif
+	ip->i_uid = uid;
+	ip->i_gid = gid;
 	ip->i_flag |= ICHG;
 	if (u.u_ruid != 0)
 		ip->i_mode &= ~(ISUID|ISGID);
-	iput(ip);
+#ifdef QUOTA
+	ip->i_dquot = inoquota(ip);
+	(void) chkdq(ip, change, 1);
+	(void) chkiq(ip->i_dev, (struct inode *)NULL, uid, 1);
+	return (u.u_error);		/* should == 0 ALWAYS !! */
+#else
+	return (0);
+#endif
 }
 
+#ifndef NOCOMPAT
 /*
  * Set IUPD and IACC times on file.
  * Can't set ICHG.
  */
-utime()
+outime()
 {
 	register struct a {
 		char	*fname;
 		time_t	*tptr;
-	} *uap;
+	} *uap = (struct a *)u.u_ap;
 	register struct inode *ip;
 	time_t tv[2];
+	struct timeval tv0, tv1;
 
-	uap = (struct a *)u.u_ap;
 	if ((ip = owner(1)) == NULL)
 		return;
-	if (copyin((caddr_t)uap->tptr, (caddr_t)tv, sizeof(tv))) {
-		u.u_error = EFAULT;
-	} else {
+	u.u_error = copyin((caddr_t)uap->tptr, (caddr_t)tv, sizeof (tv));
+	if (u.u_error == 0) {
+		ip->i_flag |= IACC|IUPD|ICHG;
+		tv0.tv_sec = tv[0]; tv0.tv_usec = 0;
+		tv1.tv_sec = tv[1]; tv1.tv_usec = 0;
+		iupdat(ip, &tv0, &tv1, 0);
+	}
+	iput(ip);
+}
+#endif
+
+utimes()
+{
+	register struct a {
+		char	*fname;
+		struct	timeval *tptr;
+	} *uap = (struct a *)u.u_ap;
+	register struct inode *ip;
+	struct timeval tv[2];
+
+	if ((ip = owner(1)) == NULL)
+		return;
+	u.u_error = copyin((caddr_t)uap->tptr, (caddr_t)tv, sizeof (tv));
+	if (u.u_error == 0) {
 		ip->i_flag |= IACC|IUPD|ICHG;
 		iupdat(ip, &tv[0], &tv[1], 0);
 	}
 	iput(ip);
 }
 
+/*
+ * Flush any pending I/O.
+ */
 sync()
 {
 
-	update(0);
+	update();
+}
+
+/*
+ * Apply an advisory lock on a file descriptor.
+ */
+flock()
+{
+	register struct a {
+		int	fd;
+		int	how;
+	} *uap = (struct a *)u.u_ap;
+	register struct file *fp;
+	register int cmd, flags;
+
+	fp = getinode(uap->fd);
+	if (fp == NULL)
+		return;
+	cmd = uap->how;
+	flags = u.u_pofile[uap->fd] & (UF_SHLOCK|UF_EXLOCK);
+	if (cmd&LOCK_UN) {
+		if (flags == 0) {
+			u.u_error = EINVAL;
+			return;
+		}
+		funlocki((struct inode *)fp->f_data, flags);
+		u.u_pofile[uap->fd] &= ~(UF_SHLOCK|UF_EXLOCK);
+		return;
+	}
+	/*
+	 * No reason to write lock a file we've already
+	 * write locked, similarly with a read lock.
+	 */
+	if ((flags&UF_EXLOCK) && (cmd&LOCK_EX) ||
+	    (flags&UF_SHLOCK) && (cmd&LOCK_SH))
+		return;
+	u.u_pofile[uap->fd] =
+	    flocki((struct inode *)fp->f_data, u.u_pofile[uap->fd], cmd);
+}
+
+/*
+ * Truncate a file given its path name.
+ */
+truncate()
+{
+	struct a {
+		char	*fname;
+		u_long	length;
+	} *uap = (struct a *)u.u_ap;
+	struct inode *ip;
+
+	ip = namei(uchar, LOOKUP, 1);
+	if (ip == NULL)
+		return;
+	if (access(ip, IWRITE))
+		goto bad;
+	if ((ip->i_mode&IFMT) == IFDIR) {
+		u.u_error = EISDIR;
+		goto bad;
+	}
+	itrunc(ip, uap->length);
+bad:
+	iput(ip);
+}
+
+/*
+ * Truncate a file given a file descriptor.
+ */
+ftruncate()
+{
+	struct a {
+		int	fd;
+		u_long	length;
+	} *uap = (struct a *)u.u_ap;
+	struct inode *ip;
+	struct file *fp;
+
+	fp = getinode(uap->fd);
+	if (fp == NULL)
+		return;
+	if ((fp->f_flag&FWRITE) == 0) {
+		u.u_error = EINVAL;
+		return;
+	}
+	ip = (struct inode *)fp->f_data;
+	ilock(ip);
+	itrunc(ip, uap->length);
+	iunlock(ip);
+}
+
+/*
+ * Synch an open file.
+ */
+fsync()
+{
+	struct a {
+		int	fd;
+	} *uap = (struct a *)u.u_ap;
+	struct inode *ip;
+	struct file *fp;
+
+	fp = getinode(uap->fd);
+	if (fp == NULL)
+		return;
+	ip = (struct inode *)fp->f_data;
+	ilock(ip);
+	syncip(ip);
+	iunlock(ip);
+}
+
+/*
+ * Rename system call.
+ * 	rename("foo", "bar");
+ * is essentially
+ *	unlink("bar");
+ *	link("foo", "bar");
+ *	unlink("foo");
+ * but ``atomically''.  Can't do full commit without saving state in the
+ * inode on disk which isn't feasible at this time.  Best we can do is
+ * always guarantee the target exists.
+ *
+ * Basic algorithm is:
+ *
+ * 1) Bump link count on source while we're linking it to the
+ *    target.  This also insure the inode won't be deleted out
+ *    from underneath us while we work.
+ * 2) Link source to destination.  If destination already exists,
+ *    delete it first.
+ * 3) Unlink source reference to inode if still around.
+ * 4) If a directory was moved and the parent of the destination
+ *    is different from the source, patch the ".." entry in the
+ *    directory.
+ *
+ * Source and destination must either both be directories, or both
+ * not be directories.  If target is a directory, it must be empty.
+ */
+rename()
+{
+	struct a {
+		char	*from;
+		char	*to;
+	} *uap;
+	register struct inode *ip, *xp, *dp;
+	int oldparent, parentdifferent, doingdirectory;
+	int error = 0;
+
+	uap = (struct a *)u.u_ap;
+	ip = namei(uchar, DELETE | LOCKPARENT, 0);
+	if (ip == NULL)
+		return;
+	dp = u.u_pdir;
+	oldparent = 0, doingdirectory = 0;
+	if ((ip->i_mode&IFMT) == IFDIR) {
+		register struct direct *d;
+
+		d = &u.u_dent;
+		/*
+		 * Avoid ".", "..", and aliases of "." for obvious reasons.
+		 */
+		if ((d->d_namlen == 1 && d->d_name[0] == '.') ||
+		    (d->d_namlen == 2 && bcmp(d->d_name, "..", 2) == 0) ||
+		    (dp == ip)) {
+			iput(dp);
+			if (dp == ip)
+				irele(ip);
+			else
+				iput(ip);
+			u.u_error = EINVAL;
+			return;
+		}
+		oldparent = dp->i_number;
+		doingdirectory++;
+	}
+	iput(dp);
+
+	/*
+	 * 1) Bump link count while we're moving stuff
+	 *    around.  If we crash somewhere before
+	 *    completing our work, the link count
+	 *    may be wrong, but correctable.
+	 */
+	ip->i_nlink++;
+	ip->i_flag |= ICHG;
+	iupdat(ip, &time, &time, 1);
+	iunlock(ip);
+
+	/*
+	 * When the target exists, both the directory
+	 * and target inodes are returned locked.
+	 */
+	u.u_dirp = (caddr_t)uap->to;
+	xp = namei(uchar, CREATE | LOCKPARENT, 0);
+	if (u.u_error) {
+		error = u.u_error;
+		goto out;
+	}
+	dp = u.u_pdir;
+	/*
+	 * If ".." must be changed (ie the directory gets a new
+	 * parent) then the source directory must not be in the
+	 * directory heirarchy above the target, as this would
+	 * orphan everything below the source directory. Also
+	 * the user must have write permission in the source so
+	 * as to be able to change "..". We must repeat the call 
+	 * to namei, as the parent directory is unlocked by the
+	 * call to checkpath().
+	 */
+	parentdifferent = oldparent != dp->i_number;
+	if (doingdirectory && parentdifferent) {
+		if (access(ip, IWRITE))
+			goto bad;
+		do {
+			dp = u.u_pdir;
+			if (xp != NULL)
+				iput(xp);
+			u.u_error = checkpath(ip, dp);
+			if (u.u_error)
+				goto out;
+			u.u_dirp = (caddr_t)uap->to;
+			xp = namei(uchar, CREATE | LOCKPARENT, 0);
+			if (u.u_error) {
+				error = u.u_error;
+				goto out;
+			}
+		} while (dp != u.u_pdir);
+	}
+	/*
+	 * 2) If target doesn't exist, link the target
+	 *    to the source and unlink the source. 
+	 *    Otherwise, rewrite the target directory
+	 *    entry to reference the source inode and
+	 *    expunge the original entry's existence.
+	 */
+	if (xp == NULL) {
+		if (dp->i_dev != ip->i_dev) {
+			error = EXDEV;
+			goto bad;
+		}
+		/*
+		 * Account for ".." in directory.
+		 * When source and destination have the
+		 * same parent we don't fool with the
+		 * link count -- this isn't required
+		 * because we do a similar check below.
+		 */
+		if (doingdirectory && parentdifferent) {
+			dp->i_nlink++;
+			dp->i_flag |= ICHG;
+			iupdat(dp, &time, &time, 1);
+		}
+		error = direnter(ip);
+		if (error)
+			goto out;
+	} else {
+		if (xp->i_dev != dp->i_dev || xp->i_dev != ip->i_dev) {
+			error = EXDEV;
+			goto bad;
+		}
+		/*
+		 * Short circuit rename(foo, foo).
+		 */
+		if (xp->i_number == ip->i_number)
+			goto bad;
+		/*
+		 * Target must be empty if a directory
+		 * and have no links to it.
+		 * Also, insure source and target are
+		 * compatible (both directories, or both
+		 * not directories).
+		 */
+		if ((xp->i_mode&IFMT) == IFDIR) {
+			if (!dirempty(xp) || xp->i_nlink > 2) {
+				error = ENOTEMPTY;
+				goto bad;
+			}
+			if (!doingdirectory) {
+				error = ENOTDIR;
+				goto bad;
+			}
+		} else if (doingdirectory) {
+			error = EISDIR;
+			goto bad;
+		}
+		dirrewrite(dp, ip);
+		if (u.u_error) {
+			error = u.u_error;
+			goto bad1;
+		}
+		/*
+		 * Adjust the link count of the target to
+		 * reflect the dirrewrite above.  If this is
+		 * a directory it is empty and there are
+		 * no links to it, so we can squash the inode and
+		 * any space associated with it.  We disallowed
+		 * renaming over top of a directory with links to
+		 * it above, as we've no way to determine if
+		 * we've got a link or the directory itself, and
+		 * if we get a link, then ".." will be screwed up.
+		 */
+		xp->i_nlink--;
+		if (doingdirectory) {
+			if (--xp->i_nlink != 0)
+				panic("rename: linked directory");
+			itrunc(xp, (u_long)0);
+		}
+		xp->i_flag |= ICHG;
+		iput(xp);
+		xp = NULL;
+	}
+
+	/*
+	 * 3) Unlink the source.
+	 */
+	u.u_dirp = uap->from;
+	dp = namei(uchar, DELETE, 0);
+	/*
+	 * Insure directory entry still exists and
+	 * has not changed since the start of all
+	 * this.  If either has occured, forget about
+	 * about deleting the original entry and just
+	 * adjust the link count in the inode.
+	 */
+	if (dp == NULL || u.u_dent.d_ino != ip->i_number) {
+		ip->i_nlink--;
+		ip->i_flag |= ICHG;
+	} else {
+		/*
+		 * If source is a directory, must adjust
+		 * link count of parent directory also.
+		 * If target didn't exist and source and
+		 * target have the same parent, then we
+		 * needn't touch the link count, it all
+		 * balances out in the end.  Otherwise, we
+		 * must do so to reflect deletion of ".."
+		 * done above.
+		 */
+		if (doingdirectory && (xp != NULL || parentdifferent)) {
+			dp->i_nlink--;
+			dp->i_flag |= ICHG;
+		}
+		if (dirremove()) {
+			ip->i_nlink--;
+			ip->i_flag |= ICHG;
+		}
+		if (error == 0)		/* conservative */
+			error = u.u_error;
+	}
+	irele(ip);
+	if (dp)
+		iput(dp);
+
+	/*
+	 * 4) Renaming a directory with the parent
+	 *    different requires ".." to be rewritten.
+	 *    The window is still there for ".." to
+	 *    be inconsistent, but this is unavoidable,
+	 *    and a lot shorter than when it was done
+	 *    in a user process.
+	 */
+	if (doingdirectory && parentdifferent && error == 0) {
+		struct dirtemplate dirbuf;
+
+		u.u_dirp = uap->to;
+		ip = namei(uchar, LOOKUP | LOCKPARENT, 0);
+		if (ip == NULL) {
+			printf("rename: .. went away\n");
+			return;
+		}
+		dp = u.u_pdir;
+		if ((ip->i_mode&IFMT) != IFDIR) {
+			printf("rename: .. not a directory\n");
+			goto stuck;
+		}
+		error = rdwri(UIO_READ, ip, (caddr_t)&dirbuf,
+			sizeof (struct dirtemplate), (off_t)0, 1, (int *)0);
+		if (error == 0) {
+			dirbuf.dotdot_ino = dp->i_number;
+			(void) rdwri(UIO_WRITE, ip, (caddr_t)&dirbuf,
+			  sizeof (struct dirtemplate), (off_t)0, 1, (int *)0);
+		}
+stuck:
+		irele(dp);
+		iput(ip);
+	}
+	goto done;
+
+bad:
+	iput(dp);
+bad1:
+	if (xp)
+		iput(xp);
+out:
+	ip->i_nlink--;
+	ip->i_flag |= ICHG;
+	irele(ip);
+done:
+	if (error)
+		u.u_error = error;
+}
+
+/*
+ * Make a new file.
+ */
+struct inode *
+maknode(mode)
+	int mode;
+{
+	register struct inode *ip;
+	ino_t ipref;
+
+	if ((mode & IFMT) == IFDIR)
+		ipref = dirpref(u.u_pdir->i_fs);
+	else
+		ipref = u.u_pdir->i_number;
+	ip = ialloc(u.u_pdir, ipref, mode);
+	if (ip == NULL) {
+		iput(u.u_pdir);
+		return (NULL);
+	}
+#ifdef QUOTA
+	if (ip->i_dquot != NODQUOT)
+		panic("maknode: dquot");
+#endif
+	ip->i_flag |= IACC|IUPD|ICHG;
+	if ((mode & IFMT) == 0)
+		mode |= IFREG;
+	ip->i_mode = mode & ~u.u_cmask;
+	ip->i_nlink = 1;
+	ip->i_uid = u.u_uid;
+	ip->i_gid = u.u_pdir->i_gid;
+	if (ip->i_mode & ISGID && !groupmember(ip->i_gid))
+		ip->i_mode &= ~ISGID;
+#ifdef QUOTA
+	ip->i_dquot = inoquota(ip);
+#endif
+
+	/*
+	 * Make sure inode goes to disk before directory entry.
+	 */
+	iupdat(ip, &time, &time, 1);
+	u.u_error = direnter(ip);
+	if (u.u_error) {
+		/*
+		 * Write error occurred trying to update directory
+		 * so must deallocate the inode.
+		 */
+		ip->i_nlink = 0;
+		ip->i_flag |= ICHG;
+		iput(ip);
+		return (NULL);
+	}
+	return (ip);
+}
+
+/*
+ * A virgin directory (no blushing please).
+ */
+struct dirtemplate mastertemplate = {
+	0, 12, 1, ".",
+	0, DIRBLKSIZ - 12, 2, ".."
+};
+
+/*
+ * Mkdir system call
+ */
+mkdir()
+{
+	struct a {
+		char	*name;
+		int	dmode;
+	} *uap;
+	register struct inode *ip, *dp;
+	struct dirtemplate dirtemplate;
+
+	uap = (struct a *)u.u_ap;
+	ip = namei(uchar, CREATE, 0);
+	if (u.u_error)
+		return;
+	if (ip != NULL) {
+		iput(ip);
+		u.u_error = EEXIST;
+		return;
+	}
+	dp = u.u_pdir;
+	uap->dmode &= 0777;
+	uap->dmode |= IFDIR;
+	/*
+	 * Must simulate part of maknode here
+	 * in order to acquire the inode, but
+	 * not have it entered in the parent
+	 * directory.  The entry is made later
+	 * after writing "." and ".." entries out.
+	 */
+	ip = ialloc(dp, dirpref(dp->i_fs), uap->dmode);
+	if (ip == NULL) {
+		iput(dp);
+		return;
+	}
+#ifdef QUOTA
+	if (ip->i_dquot != NODQUOT)
+		panic("mkdir: dquot");
+#endif
+	ip->i_flag |= IACC|IUPD|ICHG;
+	ip->i_mode = uap->dmode & ~u.u_cmask;
+	ip->i_nlink = 2;
+	ip->i_uid = u.u_uid;
+	ip->i_gid = dp->i_gid;
+#ifdef QUOTA
+	ip->i_dquot = inoquota(ip);
+#endif
+	iupdat(ip, &time, &time, 1);
+
+	/*
+	 * Bump link count in parent directory
+	 * to reflect work done below.  Should
+	 * be done before reference is created
+	 * so reparation is possible if we crash.
+	 */
+	dp->i_nlink++;
+	dp->i_flag |= ICHG;
+	iupdat(dp, &time, &time, 1);
+
+	/*
+	 * Initialize directory with "."
+	 * and ".." from static template.
+	 */
+	dirtemplate = mastertemplate;
+	dirtemplate.dot_ino = ip->i_number;
+	dirtemplate.dotdot_ino = dp->i_number;
+	u.u_error = rdwri(UIO_WRITE, ip, (caddr_t)&dirtemplate,
+		sizeof (dirtemplate), (off_t)0, 1, (int *)0);
+	if (u.u_error) {
+		dp->i_nlink--;
+		dp->i_flag |= ICHG;
+		goto bad;
+	}
+	/*
+	 * Directory all set up, now
+	 * install the entry for it in
+	 * the parent directory.
+	 */
+	u.u_error = direnter(ip);
+	dp = NULL;
+	if (u.u_error) {
+		u.u_dirp = uap->name;
+		dp = namei(uchar, LOOKUP, 0);
+		if (dp) {
+			dp->i_nlink--;
+			dp->i_flag |= ICHG;
+		}
+	}
+bad:
+	/*
+	 * No need to do an explicit itrunc here,
+	 * irele will do this for us because we set
+	 * the link count to 0.
+	 */
+	if (u.u_error) {
+		ip->i_nlink = 0;
+		ip->i_flag |= ICHG;
+	}
+	if (dp)
+		iput(dp);
+	iput(ip);
+}
+
+/*
+ * Rmdir system call.
+ */
+rmdir()
+{
+	struct a {
+		char	*name;
+	};
+	register struct inode *ip, *dp;
+
+	ip = namei(uchar, DELETE | LOCKPARENT, 0);
+	if (ip == NULL)
+		return;
+	dp = u.u_pdir;
+	/*
+	 * No rmdir "." please.
+	 */
+	if (dp == ip) {
+		irele(dp);
+		iput(ip);
+		u.u_error = EINVAL;
+		return;
+	}
+	if ((ip->i_mode&IFMT) != IFDIR) {
+		u.u_error = ENOTDIR;
+		goto out;
+	}
+	/*
+	 * Don't remove a mounted on directory.
+	 */
+	if (ip->i_dev != dp->i_dev) {
+		u.u_error = EBUSY;
+		goto out;
+	}
+	/*
+	 * Verify the directory is empty (and valid).
+	 * (Rmdir ".." won't be valid since
+	 *  ".." will contain a reference to
+	 *  the current directory and thus be
+	 *  non-empty.)
+	 */
+	if (ip->i_nlink != 2 || !dirempty(ip)) {
+		u.u_error = ENOTEMPTY;
+		goto out;
+	}
+	/*
+	 * Delete reference to directory before purging
+	 * inode.  If we crash in between, the directory
+	 * will be reattached to lost+found,
+	 */
+	if (dirremove() == 0)
+		goto out;
+	dp->i_nlink--;
+	dp->i_flag |= ICHG;
+	iput(dp);
+	dp = NULL;
+	/*
+	 * Truncate inode.  The only stuff left
+	 * in the directory is "." and "..".  The
+	 * "." reference is inconsequential since
+	 * we're quashing it.  The ".." reference
+	 * has already been adjusted above.  We've
+	 * removed the "." reference and the reference
+	 * in the parent directory, but there may be
+	 * other hard links so decrement by 2 and
+	 * worry about them later.
+	 */
+	ip->i_nlink -= 2;
+	itrunc(ip, (u_long)0);
+out:
+	if (dp)
+		iput(dp);
+	iput(ip);
+}
+
+struct file *
+getinode(fdes)
+	int fdes;
+{
+	register struct file *fp;
+
+	fp = getf(fdes);
+	if (fp == 0)
+		return (0);
+	if (fp->f_type != DTYPE_INODE) {
+		u.u_error = EINVAL;
+		return (0);
+	}
+	return (fp);
+}
+
+/*
+ * mode mask for creation of files
+ */
+umask()
+{
+	register struct a {
+		int	mask;
+	} *uap;
+
+	uap = (struct a *)u.u_ap;
+	u.u_r.r_val1 = u.u_cmask;
+	u.u_cmask = uap->mask & 07777;
 }