NFS: If the VFS sets LOOKUP_REVAL then force a lookup of the dentry

If nfs_lookup_revalidate() is called with LOOKUP_REVAL because a
previous path lookup failed, then we ought to force a full lookup
of the component name.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

fs/nfs/dir.c

@@ -1118,7 +1118,7 @@ static int nfs_lookup_revalidate(struct dentry *dentry, unsigned int flags)
 		goto out_set_verifier;
 
 	/* Force a full look up iff the parent directory has changed */
-	if (!nfs_is_exclusive_create(dir, flags) &&
+	if (!(flags & (LOOKUP_EXCL | LOOKUP_REVAL)) &&
 	    nfs_check_verifier(dir, dentry, flags & LOOKUP_RCU)) {
 		error = nfs_lookup_verify_inode(inode, flags);
 		if (error) {