--- src/sys/kern/vfs_lookup.c	2004/10/22 18:03:50	1.20
+++ src/sys/kern/vfs_lookup.c	2004/11/12 00:09:24	1.21
@@ -63,639 +63,56 @@ SYSCTL_INT(_vfs, OID_AUTO, varsym_enable
 	    "Enable Variant Symlinks");
 
 /*
- * Convert a pathname into a pointer to a locked inode.
+ * OLD API FUNCTION
  *
- * The CNP_FOLLOW flag is set when symbolic links are to be followed
- * when they occur at the end of the name translation process.
- * Symbolic links are always followed for all other pathname
- * components other than the last.
- *
- * The segflg defines whether the name is to be copied from user
- * space or kernel space.
- *
- * Overall outline of namei:
- *
- *	copy in name
- *	get starting directory
- *	while (!done && !error) {
- *		call lookup to search path.
- *		if symbolic link, massage name in buffer and continue
- *	}
- *
- * NOTE: when namei() is called from a pure thread the system rootvnode
- * will be used as a basis for the search.
- */
-int
-namei(struct nameidata *ndp)
-{
-	struct filedesc *fdp;	/* pointer to file descriptor state */
-	char *cp;		/* pointer into pathname argument */
-	struct vnode *dp;	/* the directory we are searching */
-	struct iovec aiov;		/* uio for reading symbolic links */
-	struct uio auio;
-	int error, linklen;
-	struct componentname *cnp = &ndp->ni_cnd;
-	struct proc *p;
-
-	KKASSERT(ndp->ni_cnd.cn_td != NULL);
-	p = cnp->cn_td->td_proc;
-	if (p == NULL) {
-		KKASSERT(ndp->ni_segflg == UIO_SYSSPACE);
-		printf("namei() from non-process\n");
-		fdp = NULL;
-	} else {
-		KKASSERT(cnp->cn_cred == p->p_ucred); /* YYY */
-		fdp = p->p_fd;
-	}
-	KASSERT(cnp->cn_cred, ("namei: bad cred/proc"));
-	KASSERT((cnp->cn_nameiop & (~NAMEI_OPMASK)) == 0,
-	    ("namei: nameiop contaminated with flags"));
-	KASSERT((cnp->cn_flags & NAMEI_OPMASK) == 0,
-	    ("namei: flags contaminated with nameiops"));
-
-	/*
-	 * Get a buffer for the name to be translated, and copy the
-	 * name into the buffer.
-	 */
-	if ((cnp->cn_flags & CNP_HASBUF) == 0)
-		cnp->cn_pnbuf = zalloc(namei_zone);
-	if (ndp->ni_segflg == UIO_SYSSPACE)
-		error = copystr(ndp->ni_dirp, cnp->cn_pnbuf,
-			    MAXPATHLEN, (size_t *)&ndp->ni_pathlen);
-	else
-		error = copyinstr(ndp->ni_dirp, cnp->cn_pnbuf,
-			    MAXPATHLEN, (size_t *)&ndp->ni_pathlen);
-
-	/*
-	 * Don't allow empty pathnames.
-	 * POSIX.1 requirement: "" is not a vaild file name.
-	 */
-	if (!error && *cnp->cn_pnbuf == '\0')
-		error = ENOENT;
-
-	if (error) {
-		zfree(namei_zone, cnp->cn_pnbuf);
-		ndp->ni_vp = NULL;
-		return (error);
-	}
-	ndp->ni_loopcnt = 0;
-#ifdef KTRACE
-	if (KTRPOINT(cnp->cn_td, KTR_NAMEI))
-		ktrnamei(cnp->cn_td->td_proc->p_tracep, cnp->cn_pnbuf);
-#endif
-
-	/*
-	 * Get starting point for the translation.
-	 */
-	if (fdp) {
-		ndp->ni_rootdir = fdp->fd_rdir;
-		ndp->ni_topdir = fdp->fd_jdir;
-		dp = fdp->fd_cdir;
-	} else {
-		ndp->ni_rootdir = rootvnode;
-		ndp->ni_topdir = rootvnode;
-		dp = rootvnode;
-	}
-	vref(dp);
-	for (;;) {
-		/*
-		 * Check if root directory should replace current directory.
-		 * Done at start of translation and after symbolic link.
-		 */
-		cnp->cn_nameptr = cnp->cn_pnbuf;
-		if (*(cnp->cn_nameptr) == '/') {
-			vrele(dp);
-			while (*(cnp->cn_nameptr) == '/') {
-				cnp->cn_nameptr++;
-				ndp->ni_pathlen--;
-			}
-			dp = ndp->ni_rootdir;
-			vref(dp);
-		}
-		ndp->ni_startdir = dp;
-		error = lookup(ndp);
-		if (error) {
-			zfree(namei_zone, cnp->cn_pnbuf);
-			return (error);
-		}
-		/*
-		 * Check for symbolic link
-		 */
-		if ((cnp->cn_flags & CNP_ISSYMLINK) == 0) {
-			if ((cnp->cn_flags & (CNP_SAVENAME | CNP_SAVESTART)) == 0)
-				zfree(namei_zone, cnp->cn_pnbuf);
-			else
-				cnp->cn_flags |= CNP_HASBUF;
-
-			if (vn_canvmio(ndp->ni_vp) == TRUE &&
-				(cnp->cn_nameiop != NAMEI_DELETE) &&
-				((cnp->cn_flags & (CNP_NOOBJ|CNP_LOCKLEAF)) ==
-				 CNP_LOCKLEAF))
-				vfs_object_create(ndp->ni_vp, ndp->ni_cnd.cn_td);
-
-			return (0);
-		}
-		if ((cnp->cn_flags & CNP_LOCKPARENT) && ndp->ni_pathlen == 1)
-			VOP_UNLOCK(ndp->ni_dvp, 0, cnp->cn_td);
-		if (ndp->ni_loopcnt++ >= MAXSYMLINKS) {
-			error = ELOOP;
-			break;
-		}
-		if (ndp->ni_pathlen > 1)
-			cp = zalloc(namei_zone);
-		else
-			cp = cnp->cn_pnbuf;
-		aiov.iov_base = cp;
-		aiov.iov_len = MAXPATHLEN;
-		auio.uio_iov = &aiov;
-		auio.uio_iovcnt = 1;
-		auio.uio_offset = 0;
-		auio.uio_rw = UIO_READ;
-		auio.uio_segflg = UIO_SYSSPACE;
-		auio.uio_td = cnp->cn_td;
-		auio.uio_resid = MAXPATHLEN;
-		error = VOP_READLINK(ndp->ni_vp, &auio, cnp->cn_cred);
-		if (error) {
-			if (ndp->ni_pathlen > 1)
-				zfree(namei_zone, cp);
-			break;
-		}
-		linklen = MAXPATHLEN - auio.uio_resid;
-		if (linklen == 0) {
-			if (ndp->ni_pathlen > 1)
-				zfree(namei_zone, cp);
-			error = ENOENT;
-			break;
-		}
-		if (varsym_enable) {
-			linklen = varsymreplace(cp, linklen, MAXPATHLEN);
-			if (linklen < 0) {
-				if (ndp->ni_pathlen > 1)
-					zfree(namei_zone, cp);
-				error = ENAMETOOLONG;
-				break;
-			}
-		}
-		if (linklen + ndp->ni_pathlen >= MAXPATHLEN) {
-			if (ndp->ni_pathlen > 1)
-				zfree(namei_zone, cp);
-			error = ENAMETOOLONG;
-			break;
-		}
-		if (ndp->ni_pathlen > 1) {
-			bcopy(ndp->ni_next, cp + linklen, ndp->ni_pathlen);
-			zfree(namei_zone, cnp->cn_pnbuf);
-			cnp->cn_pnbuf = cp;
-		} else {
-			cnp->cn_pnbuf[linklen] = '\0';
-		}
-		ndp->ni_pathlen += linklen;
-		vput(ndp->ni_vp);
-		dp = ndp->ni_dvp;
-	}
-	zfree(namei_zone, cnp->cn_pnbuf);
-	vrele(ndp->ni_dvp);
-	vput(ndp->ni_vp);
-	ndp->ni_vp = NULL;
-	return (error);
-}
-
-/*
- * Old API function, search a patchname.  This is an *EXTREMELY* complicated
- * function.
- *
- * The pathname is pointed to by ni_ptr and is of length ni_pathlen.
- * The starting directory is taken from ni_startdir. The pathname is
- * descended until done, or a symbolic link is encountered. The variable
- * ni_more is clear if the path is completed; it is set to one if a
- * symbolic link needing interpretation is encountered.
- *
- * The flag argument is NAMEI_LOOKUP, CREATE, RENAME, or DELETE depending on
- * whether the name is to be looked up, created, renamed, or deleted.
- * When CREATE, RENAME, or DELETE is specified, information usable in
- * creating, renaming, or deleting a directory entry may be calculated.
- * If flag has LOCKPARENT or'ed into it, the parent directory is returned
- * locked. If flag has WANTPARENT or'ed into it, the parent directory is
- * returned unlocked. Otherwise the parent directory is not returned. If
- * the target of the pathname exists and LOCKLEAF is or'ed into the flag
- * the target is returned locked, otherwise it is returned unlocked.
- * When creating or renaming and LOCKPARENT is specified, the target may not
- * be ".".  When deleting and LOCKPARENT is specified, the target may be ".".
- *
- * SPECIAL CASE: When a symbolic link is encountered the parent
- * directory is always returned in ni_dvp regardless of WANTPARENT|LOCKPARENT
- * and the symbolic link is returned in ni_vp.  If the symbolic link was not
- * the last component ni_dvp will be returned UNLOCKED, regardless of
- * LOCKPARENT.  If the symbolic link is the last component then ni_dvp will
- * be returned locked or unlocked based on LOCKPARENT.
- *
- * SPECIAL CASE: If an error occurs ni_vp and/or ni_dvp may contain garbage
- * on return.
- *
- * VOP_LOOKUP EXPECTATIONS:  VOP_LOOKUP() takes a locked directory vnode
- * and returns a locked target vnode on success.  VOP_LOOKUP() may unlock the
- * directory vnode passed to it, in which case it will set CNP_PDIRUNLOCK.
- * However, this only occurs under very specific circumstances.  The
- * directory vnode will only be returned locked if (1) returned vnode ==
- * directory vnode, or (2) CNP_LOCKPARENT *AND* CNP_LASTCN are both set.
+ * Relookup a path name component.  This function is only used by the
+ * old API *_rename() code under very specific conditions.  CNP_LOCKPARENT
+ * must be set in the cnp.  dvp must be unlocked on entry and will be left
+ * unlocked if an error occurs.
+ *
+ * The returned *vpp will be NULL if an error occurs.  Note that no error
+ * will occur (error == 0) for CREATE requests on a non-existant target, but
+ * *vpp will be NULL in that case.  Both dvp and *vpp (if not NULL) will be
+ * locked in the no-error case.   No additional references are made to dvp,
+ * only the locking state changes.
  */
 int
-lookup(struct nameidata *ndp)
+relookup(struct vnode *dvp, struct vnode **vpp, struct componentname *cnp)
 {
-	char *cp;			/* pointer into pathname argument */
-	struct vnode *dp = NULL;	/* the directory we are searching */
-	struct vnode *tdp;		/* saved dp */
-	struct mount *mp;		/* mount table entry */
-	int docache;			/* == 0 do not cache last component */
-	int wantparent;			/* 1 => wantparent or lockparent flag */
+	struct thread *td = cnp->cn_td;
 	int rdonly;			/* lookup read-only flag bit */
-	int trailing_slash;
 	int error = 0;
-	int dpunlocked = 0;		/* dp has already been unlocked */
-	struct componentname *cnp = &ndp->ni_cnd;
-	struct thread *td = cnp->cn_td;
 
 	/*
 	 * Setup: break out flag bits into variables.
 	 */
-	wantparent = cnp->cn_flags & (CNP_LOCKPARENT | CNP_WANTPARENT);
-	docache = (cnp->cn_flags & CNP_NOCACHE) ^ CNP_NOCACHE;
-	if (cnp->cn_nameiop == NAMEI_DELETE ||
-	    (wantparent && cnp->cn_nameiop != NAMEI_CREATE &&
-	     cnp->cn_nameiop != NAMEI_LOOKUP))
-		docache = 0;
-	rdonly = cnp->cn_flags & CNP_RDONLY;
-	ndp->ni_dvp = NULL;
-	cnp->cn_flags &= ~CNP_ISSYMLINK;
-	dp = ndp->ni_startdir;
-	ndp->ni_startdir = NULLVP;
-	vn_lock(dp, LK_EXCLUSIVE | LK_RETRY, td);
-
-dirloop:
-	/*
-	 * Search a new directory.
-	 *
-	 * The last component of the filename is left accessible via
-	 * cnp->cn_nameptr for callers that need the name. Callers needing
-	 * the name set the CNP_SAVENAME flag. When done, they assume
-	 * responsibility for freeing the pathname buffer.
-	 */
-	cnp->cn_consume = 0;
-	for (cp = cnp->cn_nameptr; *cp != 0 && *cp != '/'; cp++)
-		continue;
-	cnp->cn_namelen = cp - cnp->cn_nameptr;
-	if (cnp->cn_namelen > NAME_MAX) {
-		error = ENAMETOOLONG;
-		goto bad;
-	}
-#ifdef NAMEI_DIAGNOSTIC
-	{ char c = *cp;
-	*cp = '\0';
-	printf("{%s}: ", cnp->cn_nameptr);
-	*cp = c; }
-#endif
-	ndp->ni_pathlen -= cnp->cn_namelen;
-	ndp->ni_next = cp;
-
-	/*
-	 * Replace multiple slashes by a single slash and trailing slashes
-	 * by a null.  This must be done before VOP_LOOKUP() because some
-	 * fs's don't know about trailing slashes.  Remember if there were
-	 * trailing slashes to handle symlinks, existing non-directories
-	 * and non-existing files that won't be directories specially later.
-	 */
-	trailing_slash = 0;
-	while (*cp == '/' && (cp[1] == '/' || cp[1] == '\0')) {
-		cp++;
-		ndp->ni_pathlen--;
-		if (*cp == '\0') {
-			trailing_slash = 1;
-			*ndp->ni_next = '\0';	/* XXX for direnter() ... */
-		}
-	}
-	ndp->ni_next = cp;
-
-	cnp->cn_flags |= CNP_MAKEENTRY;
-	if (*cp == '\0' && docache == 0)
-		cnp->cn_flags &= ~CNP_MAKEENTRY;
-	if (cnp->cn_namelen == 2 &&
-	    cnp->cn_nameptr[1] == '.' && cnp->cn_nameptr[0] == '.')
-		cnp->cn_flags |= CNP_ISDOTDOT;
-	else
-		cnp->cn_flags &= ~CNP_ISDOTDOT;
-	if (*ndp->ni_next == 0)
-		cnp->cn_flags |= CNP_ISLASTCN;
-	else
-		cnp->cn_flags &= ~CNP_ISLASTCN;
-
-
-	/*
-	 * Check for degenerate name (e.g. / or "")
-	 * which is a way of talking about a directory,
-	 * e.g. like "/." or ".".
-	 */
-	if (cnp->cn_nameptr[0] == '\0') {
-		if (dp->v_type != VDIR) {
-			error = ENOTDIR;
-			goto bad;
-		}
-		if (cnp->cn_nameiop != NAMEI_LOOKUP) {
-			error = EISDIR;
-			goto bad;
-		}
-		if (wantparent) {
-			ndp->ni_dvp = dp;
-			vref(dp);
-		}
-		ndp->ni_vp = dp;
-		if (!(cnp->cn_flags & (CNP_LOCKPARENT | CNP_LOCKLEAF)))
-			VOP_UNLOCK(dp, 0, cnp->cn_td);
-		/* XXX This should probably move to the top of function. */
-		if (cnp->cn_flags & CNP_SAVESTART)
-			panic("lookup: CNP_SAVESTART");
-		return (0);
-	}
-
-	/*
-	 * Handle "..": two special cases.
-	 * 1. If at root directory (e.g. after chroot)
-	 *    or at absolute root directory
-	 *    then ignore it so can't get out.
-	 * 2. If this vnode is the root of a mounted
-	 *    filesystem, then replace it with the
-	 *    vnode which was mounted on so we take the
-	 *    .. in the other file system.
-	 * 3. If the vnode is the top directory of
-	 *    the jail or chroot, don't let them out.
-	 */
-	if (cnp->cn_flags & CNP_ISDOTDOT) {
-		for (;;) {
-			if (dp == ndp->ni_rootdir || 
-			    dp == ndp->ni_topdir || 
-			    dp == rootvnode) {
-				ndp->ni_dvp = dp;
-				ndp->ni_vp = dp;
-				vref(dp);
-				goto nextname;
-			}
-			if ((dp->v_flag & VROOT) == 0 ||
-			    (cnp->cn_flags & CNP_NOCROSSMOUNT))
-				break;
-			if (dp->v_mount == NULL) {	/* forced unmount */
-				error = EBADF;
-				goto bad;
-			}
-			tdp = dp;
-			dp = dp->v_mount->mnt_vnodecovered;
-			vput(tdp);
-			vref(dp);
-			vn_lock(dp, LK_EXCLUSIVE | LK_RETRY, td);
-		}
-	}
-
-	/*
-	 * We now have a segment name to search for, and a directory to search.
-	 */
-unionlookup:
-	ndp->ni_dvp = dp;
-	ndp->ni_vp = NULL;
+	KKASSERT(cnp->cn_flags & CNP_LOCKPARENT);
+	KKASSERT(cnp->cn_flags & CNP_PDIRUNLOCK);
+	vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY, td);
 	cnp->cn_flags &= ~CNP_PDIRUNLOCK;
-	ASSERT_VOP_LOCKED(dp, "lookup");
-	if ((error = VOP_LOOKUP(dp, &ndp->ni_vp, cnp)) != 0) {
-		KASSERT(ndp->ni_vp == NULL, ("leaf should be empty"));
-#ifdef NAMEI_DIAGNOSTIC
-		printf("not found\n");
-#endif
-		if ((error == ENOENT) &&
-		    (dp->v_flag & VROOT) && (dp->v_mount != NULL) &&
-		    (dp->v_mount->mnt_flag & MNT_UNION)) {
-			tdp = dp;
-			dp = dp->v_mount->mnt_vnodecovered;
-			if (cnp->cn_flags & CNP_PDIRUNLOCK)
-				vrele(tdp);
-			else
-				vput(tdp);
-			vref(dp);
-			vn_lock(dp, LK_EXCLUSIVE | LK_RETRY, td);
-			goto unionlookup;
-		}
-
-		if (error != EJUSTRETURN)
-			goto bad;
-		/*
-		 * If creating and at end of pathname, then can consider
-		 * allowing file to be created.
-		 */
-		if (rdonly) {
-			error = EROFS;
-			goto bad;
-		}
-		if (*cp == '\0' && trailing_slash &&
-		     !(cnp->cn_flags & CNP_WILLBEDIR)) {
-			error = ENOENT;
-			goto bad;
-		}
-		/*
-		 * We return with ni_vp NULL to indicate that the entry
-		 * doesn't currently exist, leaving a pointer to the
-		 * (possibly locked) directory inode in ndp->ni_dvp.
-		 */
-		if (cnp->cn_flags & CNP_SAVESTART) {
-			ndp->ni_startdir = ndp->ni_dvp;
-			vref(ndp->ni_startdir);
-		}
-		return (0);
-	}
-#ifdef NAMEI_DIAGNOSTIC
-	printf("found\n");
-#endif
-
-	ASSERT_VOP_LOCKED(ndp->ni_vp, "lookup");
-
-	/*
-	 * Take into account any additional components consumed by
-	 * the underlying filesystem.
-	 */
-	if (cnp->cn_consume > 0) {
-		cnp->cn_nameptr += cnp->cn_consume;
-		ndp->ni_next += cnp->cn_consume;
-		ndp->ni_pathlen -= cnp->cn_consume;
-		cnp->cn_consume = 0;
-	}
-
-	dp = ndp->ni_vp;
-
-	/*
-	 * Check to see if the vnode has been mounted on;
-	 * if so find the root of the mounted file system.
-	 */
-	while (dp->v_type == VDIR && (mp = dp->v_mountedhere) &&
-	       (cnp->cn_flags & CNP_NOCROSSMOUNT) == 0) {
-		if (vfs_busy(mp, 0, NULL, td))
-			continue;
-		VOP_UNLOCK(dp, 0, td);
-		error = VFS_ROOT(mp, &tdp);
-		vfs_unbusy(mp, td);
-		if (error) {
-			dpunlocked = 1;
-			goto bad2;
-		}
-		vrele(dp);
-		ndp->ni_vp = dp = tdp;
-	}
-
-	/*
-	 * Check for symbolic link
-	 */
-	if ((dp->v_type == VLNK) &&
-	    ((cnp->cn_flags & CNP_FOLLOW) || trailing_slash ||
-	     *ndp->ni_next == '/')) {
-		cnp->cn_flags |= CNP_ISSYMLINK;
-		if (dp->v_mount == NULL) {
-			/* We can't know whether the directory was mounted with
-			 * NOSYMFOLLOW, so we can't follow safely. */
-			error = EBADF;
-			goto bad2;
-		}
-		if (dp->v_mount->mnt_flag & MNT_NOSYMFOLLOW) {
-			error = EACCES;
-			goto bad2;
-		}
-		return (0);
-	}
-
-	/*
-	 * Check for bogus trailing slashes.
-	 */
-	if (trailing_slash && dp->v_type != VDIR) {
-		error = ENOTDIR;
-		goto bad2;
-	}
-
-nextname:
-	/*
-	 * Not a symbolic link.  If more pathname,
-	 * continue at next component, else return.
-	 */
-	if (*ndp->ni_next == '/') {
-		cnp->cn_nameptr = ndp->ni_next;
-		while (*cnp->cn_nameptr == '/') {
-			cnp->cn_nameptr++;
-			ndp->ni_pathlen--;
-		}
-		if (ndp->ni_dvp != ndp->ni_vp)
-			ASSERT_VOP_UNLOCKED(ndp->ni_dvp, "lookup");
-		vrele(ndp->ni_dvp);
-		goto dirloop;
-	}
-	/*
-	 * Disallow directory write attempts on read-only file systems.
-	 */
-	if (rdonly &&
-	    (cnp->cn_nameiop == NAMEI_DELETE || cnp->cn_nameiop == NAMEI_RENAME)) {
-		error = EROFS;
-		goto bad2;
-	}
-	if (cnp->cn_flags & CNP_SAVESTART) {
-		ndp->ni_startdir = ndp->ni_dvp;
-		vref(ndp->ni_startdir);
-	}
-	if (!wantparent)
-		vrele(ndp->ni_dvp);
-
-	if ((cnp->cn_flags & CNP_LOCKLEAF) == 0)
-		VOP_UNLOCK(dp, 0, td);
-	return (0);
 
-bad2:
-	if ((cnp->cn_flags & (CNP_LOCKPARENT | CNP_PDIRUNLOCK)) == CNP_LOCKPARENT &&
-	    *ndp->ni_next == '\0')
-		VOP_UNLOCK(ndp->ni_dvp, 0, td);
-	vrele(ndp->ni_dvp);
-bad:
-	if (dpunlocked)
-		vrele(dp);
-	else
-		vput(dp);
-	ndp->ni_vp = NULL;
-	return (error);
-}
-
-/*
- * relookup - lookup a path name component
- *    Used by lookup to re-aquire things.
- */
-int
-relookup(dvp, vpp, cnp)
-	struct vnode *dvp, **vpp;
-	struct componentname *cnp;
-{
-	struct thread *td = cnp->cn_td;
-	struct vnode *dp = 0;		/* the directory we are searching */
-	int wantparent;			/* 1 => wantparent or lockparent flag */
-	int rdonly;			/* lookup read-only flag bit */
-	int error = 0;
-#ifdef NAMEI_DIAGNOSTIC
-	int newhash;			/* DEBUG: check name hash */
-	char *cp;			/* DEBUG: check name ptr/len */
-#endif
-
-	/*
-	 * Setup: break out flag bits into variables.
-	 */
-	wantparent = cnp->cn_flags & (CNP_LOCKPARENT|CNP_WANTPARENT);
+	*vpp = NULL;
 	rdonly = cnp->cn_flags & CNP_RDONLY;
-	cnp->cn_flags &= ~CNP_ISSYMLINK;
-	dp = dvp;
-	vn_lock(dp, LK_EXCLUSIVE | LK_RETRY, td);
 
-/* dirloop: */
 	/*
 	 * Search a new directory.
-	 *
-	 * The last component of the filename is left accessible via
-	 * cnp->cn_nameptr for callers that need the name. Callers needing
-	 * the name set the CNP_SAVENAME flag. When done, they assume
-	 * responsibility for freeing the pathname buffer.
 	 */
-#ifdef NAMEI_DIAGNOSTIC
-	if (cnp->cn_namelen != cp - cnp->cn_nameptr)
-		panic ("relookup: bad len");
-	if (*cp != 0)
-		panic("relookup: not last component");
-	printf("{%s}: ", cnp->cn_nameptr);
-#endif
 
 	/*
-	 * Check for degenerate name (e.g. / or "")
-	 * which is a way of talking about a directory,
-	 * e.g. like "/." or ".".
+	 * Degenerate lookups (e.g. "/", "..", derived from "/.", etc)
+	 * are not allowed.
 	 */
 	if (cnp->cn_nameptr[0] == '\0') {
-		if (cnp->cn_nameiop != NAMEI_LOOKUP || wantparent) {
-			error = EISDIR;
-			goto bad;
-		}
-		if (dp->v_type != VDIR) {
-			error = ENOTDIR;
-			goto bad;
-		}
-		if (!(cnp->cn_flags & CNP_LOCKLEAF))
-			VOP_UNLOCK(dp, 0, td);
-		*vpp = dp;
-		/* XXX This should probably move to the top of function. */
-		if (cnp->cn_flags & CNP_SAVESTART)
-			panic("lookup: CNP_SAVESTART");
-		return (0);
+		error = EISDIR;
+		goto bad;
 	}
-
 	if (cnp->cn_flags & CNP_ISDOTDOT)
 		panic ("relookup: lookup on dot-dot");
 
 	/*
 	 * We now have a segment name to search for, and a directory to search.
 	 */
-	if ((error = VOP_LOOKUP(dp, vpp, cnp)) != 0) {
+	if ((error = VOP_OLD_LOOKUP(dvp, vpp, cnp)) != 0) {
 		KASSERT(*vpp == NULL, ("leaf should be empty"));
 		if (error != EJUSTRETURN)
 			goto bad;
@@ -707,9 +124,6 @@ relookup(dvp, vpp, cnp)
 			error = EROFS;
 			goto bad;
 		}
-		/* ASSERT(dvp == ndp->ni_startdir) */
-		if (cnp->cn_flags & CNP_SAVESTART)
-			vref(dvp);
 		/*
 		 * We return with ni_vp NULL to indicate that the entry
 		 * doesn't currently exist, leaving a pointer to the
@@ -717,43 +131,33 @@ relookup(dvp, vpp, cnp)
 		 */
 		return (0);
 	}
-	dp = *vpp;
 
 	/*
 	 * Check for symbolic link
 	 */
-	KASSERT(dp->v_type != VLNK || !(cnp->cn_flags & CNP_FOLLOW),
+	KASSERT((*vpp)->v_type != VLNK || !(cnp->cn_flags & CNP_FOLLOW),
 	    ("relookup: symlink found.\n"));
 
 	/*
 	 * Disallow directory write attempts on read-only file systems.
 	 */
-	if (rdonly &&
-	    (cnp->cn_nameiop == NAMEI_DELETE || cnp->cn_nameiop == NAMEI_RENAME)) {
+	if (rdonly && (cnp->cn_nameiop == NAMEI_DELETE || 
+			cnp->cn_nameiop == NAMEI_RENAME)) {
 		error = EROFS;
-		goto bad2;
+		goto bad;
 	}
-	/* ASSERT(dvp == ndp->ni_startdir) */
-	if (cnp->cn_flags & CNP_SAVESTART)
-		vref(dvp);
-	
-	if (!wantparent)
-		vrele(dvp);
-
-	if (vn_canvmio(dp) == TRUE &&
-		((cnp->cn_flags & (CNP_NOOBJ|CNP_LOCKLEAF)) == CNP_LOCKLEAF))
-		vfs_object_create(dp, cnp->cn_td);
-
-	if ((cnp->cn_flags & CNP_LOCKLEAF) == 0)
-		VOP_UNLOCK(dp, 0, td);
+	KKASSERT((cnp->cn_flags & CNP_PDIRUNLOCK) == 0);
 	return (0);
 
-bad2:
-	if ((cnp->cn_flags & CNP_LOCKPARENT) && (cnp->cn_flags & CNP_ISLASTCN))
-		VOP_UNLOCK(dvp, 0, td);
-	vrele(dvp);
 bad:
-	vput(dp);
-	*vpp = NULL;
+	if ((cnp->cn_flags & CNP_PDIRUNLOCK) == 0) {
+		cnp->cn_flags |= CNP_PDIRUNLOCK;
+		VOP_UNLOCK(dvp, 0, td);
+	}
+	if (*vpp) {
+		vput(*vpp);
+		*vpp = NULL;
+	}
 	return (error);
 }
+