--- grub-core/kern/emu/getroot.c	2011-05-21 05:03:55 +0000
+++ grub-core/kern/emu/getroot.c	2011-06-23 17:50:41 +0000
@@ -616,13 +616,15 @@
 
   if (os_dev)
     {
-      if (strncmp (os_dev, "/dev/dm-", sizeof ("/dev/dm-") - 1) != 0)
+      int dm = (strncmp (os_dev, "/dev/dm-", sizeof ("/dev/dm-") - 1) == 0);
+      int root = (strcmp (os_dev, "/dev/root") == 0);
+      if (!dm && !root)
 	return os_dev;
       if (stat (os_dev, &st) < 0)
 	grub_util_error ("cannot stat `%s'", os_dev);
       free (os_dev);
       dev = st.st_rdev;
-      return grub_find_device ("/dev/mapper", dev);
+      return grub_find_device (dm ? "/dev/mapper" : "/dev", dev);
     }
 
   if (stat (dir, &st) < 0)