diff -u --recursive --new-file linux-2.4.12-seekdir/fs/namei.c linux-2.4.12-cto/fs/namei.c
--- linux-2.4.12-seekdir/fs/namei.c	Thu Oct 11 11:04:23 2001
+++ linux-2.4.12-cto/fs/namei.c	Thu Oct 11 11:07:06 2001
@@ -454,7 +454,7 @@
 	while (*name=='/')
 		name++;
 	if (!*name)
-		goto return_base;
+		goto return_reval;
 
 	inode = nd->dentry->d_inode;
 	if (current->link_count)
@@ -573,7 +573,7 @@
 				inode = nd->dentry->d_inode;
 				/* fallthrough */
 			case 1:
-				goto return_base;
+				goto return_reval;
 		}
 		if (nd->dentry->d_op && nd->dentry->d_op->d_hash) {
 			err = nd->dentry->d_op->d_hash(nd->dentry, &this);
@@ -624,6 +624,17 @@
 			nd->last_type = LAST_DOT;
 		else if (this.len == 2 && this.name[1] == '.')
 			nd->last_type = LAST_DOTDOT;
+return_reval:
+		/*
+		 * We bypassed the ordinary revalidation routines, so
+		 * NFS wants to check the cached inode for staleness.
+		 */
+		inode = nd->dentry->d_inode;
+		if (inode && inode->i_op && inode->i_op->check_stale) {
+			err = inode->i_op->check_stale(inode);
+			if (err)
+				break;
+		}
 return_base:
 		return 0;
 out_dput:
diff -u --recursive --new-file linux-2.4.12-seekdir/fs/nfs/dir.c linux-2.4.12-cto/fs/nfs/dir.c
--- linux-2.4.12-seekdir/fs/nfs/dir.c	Thu Oct 11 11:06:46 2001
+++ linux-2.4.12-cto/fs/nfs/dir.c	Thu Oct 11 14:26:26 2001
@@ -68,6 +68,7 @@
 	permission:	nfs_permission,
 	revalidate:	nfs_revalidate,
 	setattr:	nfs_notify_change,
+	check_stale:	nfs_check_stale,
 };
 
 static loff_t nfs_dir_llseek(struct file *file, loff_t offset, int origin)
@@ -422,6 +423,32 @@
 	return 0;
 }
 
+static inline
+void nfs_renew_verifier(struct inode *dir, struct dentry *dentry)
+{
+	u64 mtime = NFS_CACHE_MTIME(dir);
+	dentry->d_rtime_sec = mtime >> 32;
+	dentry->d_rtime_nsec = mtime & 0xffffffffUL;
+}
+
+/*
+ * A check for whether or not the parent directory has changed.
+ * In the case it has, we assume that the dentries are untrustworthy
+ * and may need to be looked up again.
+ */
+static inline
+int nfs_check_verifier(struct inode *dir, struct dentry *dentry)
+{
+	u64 mtime;
+	if (IS_ROOT(dentry))
+		return 1;
+	if (nfs_revalidate_inode(NFS_SERVER(dir), dir))
+		return 0;
+	mtime = NFS_CACHE_MTIME(dir);
+	return (dentry->d_rtime_sec == (mtime >> 32)) &&
+		(dentry->d_rtime_nsec == (mtime & 0xffffffffUL));
+}
+
 /*
  * Whenever an NFS operation succeeds, we know that the dentry
  * is valid, so we update the revalidation timestamp.
@@ -429,50 +456,34 @@
 static inline void nfs_renew_times(struct dentry * dentry)
 {
 	dentry->d_time = jiffies;
+	nfs_renew_verifier(dentry->d_parent->d_inode, dentry);
 }
 
-static inline int nfs_dentry_force_reval(struct dentry *dentry, int flags)
+static inline
+int nfs_lookup_verify_inode(struct inode *inode, int flags)
 {
-	struct inode *inode = dentry->d_inode;
-	unsigned long timeout = NFS_ATTRTIMEO(inode);
-
+	struct nfs_server *server = NFS_SERVER(inode);
 	/*
-	 * If it's the last lookup in a series, we use a stricter
-	 * cache consistency check by looking at the parent mtime.
-	 *
-	 * If it's been modified in the last hour, be really strict.
-	 * (This still means that we can avoid doing unnecessary
-	 * work on directories like /usr/share/bin etc which basically
-	 * never change).
+	 * If we're interested in close-to-open cache consistency,
+	 * then we revalidate the inode upon lookup.
 	 */
-	if (!(flags & LOOKUP_CONTINUE)) {
-		long diff = CURRENT_TIME - dentry->d_parent->d_inode->i_mtime;
-
-		if (diff < 15*60)
-			timeout = 0;
-	}
-	
-	return time_after(jiffies,dentry->d_time + timeout);
+	if (!(server->flags & NFS_MOUNT_NOCTO) && !(flags & LOOKUP_CONTINUE))
+		NFS_CACHEINV(inode);
+	return nfs_revalidate_inode(server, inode);
 }
 
 /*
  * We judge how long we want to trust negative
  * dentries by looking at the parent inode mtime.
  *
- * If mtime is close to present time, we revalidate
- * more often.
+ * If parent mtime has changed, we revalidate, else we wait for a
+ * period corresponding to the parent's attribute cache timeout value.
  */
-#define NFS_REVALIDATE_NEGATIVE (1 * HZ)
-static inline int nfs_neg_need_reval(struct dentry *dentry)
+static inline int nfs_neg_need_reval(struct inode *dir, struct dentry *dentry)
 {
-	struct inode *dir = dentry->d_parent->d_inode;
-	unsigned long timeout = NFS_ATTRTIMEO(dir);
-	long diff = CURRENT_TIME - dir->i_mtime;
-
-	if (diff < 5*60 && timeout > NFS_REVALIDATE_NEGATIVE)
-		timeout = NFS_REVALIDATE_NEGATIVE;
-
-	return time_after(jiffies, dentry->d_time + timeout);
+	if (!nfs_check_verifier(dir, dentry))
+		return 1;
+	return time_after(jiffies, dentry->d_time + NFS_ATTRTIMEO(dir));
 }
 
 /*
@@ -483,9 +494,8 @@
  * NOTE! The hit can be a negative hit too, don't assume
  * we have an inode!
  *
- * If the dentry is older than the revalidation interval, 
- * we do a new lookup and verify that the dentry is still
- * correct.
+ * If the parent directory is seen to have changed, we throw out the
+ * cached dentry and do a new lookup.
  */
 static int nfs_lookup_revalidate(struct dentry * dentry, int flags)
 {
@@ -498,13 +508,9 @@
 	lock_kernel();
 	dir = dentry->d_parent->d_inode;
 	inode = dentry->d_inode;
-	/*
-	 * If we don't have an inode, let's look at the parent
-	 * directory mtime to get a hint about how often we
-	 * should validate things..
-	 */
+
 	if (!inode) {
-		if (nfs_neg_need_reval(dentry))
+		if (nfs_neg_need_reval(dir, dentry))
 			goto out_bad;
 		goto out_valid;
 	}
@@ -515,48 +521,39 @@
 		goto out_bad;
 	}
 
-	if (!nfs_dentry_force_reval(dentry, flags))
+	/* Force a full look up iff the parent directory has changed */
+	if (nfs_check_verifier(dir, dentry)) {
+		if (nfs_lookup_verify_inode(inode, flags))
+			goto out_bad;
 		goto out_valid;
-
-	if (IS_ROOT(dentry)) {
-		__nfs_revalidate_inode(NFS_SERVER(inode), inode);
-		goto out_valid_renew;
 	}
 
-	/*
-	 * Do a new lookup and check the dentry attributes.
-	 */
+	if (NFS_STALE(inode))
+		goto out_bad;
+
 	error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, &fhandle, &fattr);
 	if (error)
 		goto out_bad;
-
-	/* Inode number matches? */
-	if (!(fattr.valid & NFS_ATTR_FATTR) ||
-	    NFS_FSID(inode) != fattr.fsid ||
-	    NFS_FILEID(inode) != fattr.fileid)
+	if (memcmp(NFS_FH(inode), &fhandle, sizeof(struct nfs_fh))!= 0)
 		goto out_bad;
-
-	/* Ok, remember that we successfully checked it.. */
-	nfs_refresh_inode(inode, &fattr);
-
-	if (nfs_inode_is_stale(inode, &fhandle, &fattr))
+	if ((error = nfs_refresh_inode(inode, &fattr)) != 0)
 		goto out_bad;
 
- out_valid_renew:
 	nfs_renew_times(dentry);
-out_valid:
+ out_valid:
 	unlock_kernel();
 	return 1;
-out_bad:
-	shrink_dcache_parent(dentry);
-	/* If we have submounts, don't unhash ! */
-	if (have_submounts(dentry))
-		goto out_valid;
-	d_drop(dentry);
-	/* Purge readdir caches. */
-	nfs_zap_caches(dir);
-	if (inode && S_ISDIR(inode->i_mode))
+ out_bad:
+	NFS_CACHEINV(dir);
+	if (inode && S_ISDIR(inode->i_mode)) {
+		/* Purge readdir caches. */
 		nfs_zap_caches(inode);
+		/* If we have submounts, don't unhash ! */
+		if (have_submounts(dentry))
+			goto out_valid;
+		shrink_dcache_parent(dentry);
+	}
+	d_drop(dentry);
 	unlock_kernel();
 	return 0;
 }
@@ -625,9 +622,9 @@
 		if (inode) {
 	    no_entry:
 			d_add(dentry, inode);
-			nfs_renew_times(dentry);
 			error = 0;
 		}
+		nfs_renew_times(dentry);
 	}
 out:
 	return ERR_PTR(error);
diff -u --recursive --new-file linux-2.4.12-seekdir/fs/nfs/inode.c linux-2.4.12-cto/fs/nfs/inode.c
--- linux-2.4.12-seekdir/fs/nfs/inode.c	Thu Oct 11 11:04:08 2001
+++ linux-2.4.12-cto/fs/nfs/inode.c	Thu Oct 11 11:07:06 2001
@@ -651,27 +651,6 @@
 	return 1;
 }
 
-int
-nfs_inode_is_stale(struct inode *inode, struct nfs_fh *fh, struct nfs_fattr *fattr)
-{
-	/* Empty inodes are not stale */
-	if (!inode->i_mode)
-		return 0;
-
-	if ((fattr->mode & S_IFMT) != (inode->i_mode & S_IFMT))
-		return 1;
-
-	if (is_bad_inode(inode) || NFS_STALE(inode))
-		return 1;
-
-	/* Has the filehandle changed? If so is the old one stale? */
-	if (memcmp(&inode->u.nfs_i.fh, fh, sizeof(inode->u.nfs_i.fh)) != 0 &&
-	    __nfs_revalidate_inode(NFS_SERVER(inode),inode) == -ESTALE)
-		return 1;
-
-	return 0;
-}
-
 /*
  * This is our own version of iget that looks up inodes by file handle
  * instead of inode number.  We use this technique instead of using
@@ -737,7 +716,7 @@
 	/*
 	 * Make sure the inode is up-to-date.
 	 */
-	error = nfs_revalidate(dentry);
+	error = nfs_revalidate_inode(NFS_SERVER(inode),inode);
 	if (error) {
 #ifdef NFS_PARANOIA
 printk("nfs_notify_change: revalidate failed, error=%d\n", error);
@@ -806,6 +785,21 @@
 {
 	struct inode *inode = dentry->d_inode;
 	return nfs_revalidate_inode(NFS_SERVER(inode), inode);
+}
+
+/*
+ * Another revalidation function: This one checks inodes for staleness
+ * when we've bypassed the ordinary dcache revalidation routines.
+ * e.g. open(".")
+ */
+int
+nfs_check_stale(struct inode *inode)
+{
+	if (!(NFS_SERVER(inode)->flags & NFS_MOUNT_NOCTO))
+		NFS_CACHEINV(inode);
+	if (NFS_STALE(inode))
+		return -ESTALE;
+	return 0;
 }
 
 /*
diff -u --recursive --new-file linux-2.4.12-seekdir/fs/nfs/nfs3proc.c linux-2.4.12-cto/fs/nfs/nfs3proc.c
--- linux-2.4.12-seekdir/fs/nfs/nfs3proc.c	Thu Oct 11 11:06:20 2001
+++ linux-2.4.12-cto/fs/nfs/nfs3proc.c	Thu Oct 11 11:07:06 2001
@@ -80,7 +80,8 @@
 		status = rpc_call(NFS_CLIENT(dir), NFS3PROC_GETATTR,
 			 fhandle, fattr, 0);
 	dprintk("NFS reply lookup: %d\n", status);
-	nfs_refresh_inode(dir, &dir_attr);
+	if (status >= 0)
+		status = nfs_refresh_inode(dir, &dir_attr);
 	return status;
 }
 
diff -u --recursive --new-file linux-2.4.12-seekdir/include/linux/dcache.h linux-2.4.12-cto/include/linux/dcache.h
--- linux-2.4.12-seekdir/include/linux/dcache.h	Thu Oct 11 11:04:10 2001
+++ linux-2.4.12-cto/include/linux/dcache.h	Thu Oct 11 14:16:05 2001
@@ -80,6 +80,8 @@
 	struct super_block * d_sb;	/* The root of the dentry tree */
 	unsigned long d_vfs_flags;
 	void * d_fsdata;		/* fs-specific data */
+	unsigned long d_rtime_sec;	/* used by nfs d_revalidate */
+	unsigned long d_rtime_nsec;	/* used by nfs d_revalidate */
 	unsigned char d_iname[DNAME_INLINE_LEN]; /* small names */
 };
 
diff -u --recursive --new-file linux-2.4.12-seekdir/include/linux/fs.h linux-2.4.12-cto/include/linux/fs.h
--- linux-2.4.12-seekdir/include/linux/fs.h	Thu Oct 11 11:04:24 2001
+++ linux-2.4.12-cto/include/linux/fs.h	Thu Oct 11 11:07:06 2001
@@ -837,6 +837,7 @@
 	int (*revalidate) (struct dentry *);
 	int (*setattr) (struct dentry *, struct iattr *);
 	int (*getattr) (struct dentry *, struct iattr *);
+	int (*check_stale) (struct inode *);
 };
 
 /*
diff -u --recursive --new-file linux-2.4.12-seekdir/include/linux/nfs_fs.h linux-2.4.12-cto/include/linux/nfs_fs.h
--- linux-2.4.12-seekdir/include/linux/nfs_fs.h	Sun Sep 23 19:32:25 2001
+++ linux-2.4.12-cto/include/linux/nfs_fs.h	Thu Oct 11 11:07:06 2001
@@ -152,6 +152,7 @@
 extern int nfs_open(struct inode *, struct file *);
 extern int nfs_release(struct inode *, struct file *);
 extern int __nfs_revalidate_inode(struct nfs_server *, struct inode *);
+extern int nfs_check_stale(struct inode *);
 extern int nfs_notify_change(struct dentry *, struct iattr *);
 
 /*