--- dosfstools-2.10/mkdosfs/mkdosfs.c~	2004-07-20 13:58:43 +0400
+++ dosfstools-2.10/mkdosfs/mkdosfs.c	2004-07-20 14:02:51 +0400
@@ -596,7 +596,10 @@ check_mount (char *device_name)
     return;
   while ((mnt = getmntent (f)) != NULL)
     if (strcmp (device_name, mnt->mnt_fsname) == 0)
+    {
+	if ( (strcmp("subfs", mnt->mnt_type) != 0) && (strcmp("supermount", mnt->mnt_type) != 0) )
       die ("%s contains a mounted file system.");
+    }
   endmntent (f);
 }