debug patch for bz 787171/766277

diff --git a/fs/dcache.c b/fs/dcache.c
index bcbdb33..a6a5fdb 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -2530,8 +2530,10 @@ global_root:
 	 */
 	if (IS_ROOT(dentry) &&
 	    (dentry->d_name.len != 1 || dentry->d_name.name[0] != '/')) {
-		WARN(1, "Root dentry has weird name <%.*s>\n",
-		     (int) dentry->d_name.len, dentry->d_name.name);
+		WARN(1, "Root dentry has weird name <%.*s>  vfsmnt:%s fs:%s\n",
+		     (int) dentry->d_name.len, dentry->d_name.name,
+			vfsmnt->mnt_root->d_name.name,
+			vfsmnt->mnt_sb->s_type->name);
 	}
 	if (!slash)
 		error = prepend(buffer, buflen, "/", 1);