--- util-linux-ng-2.13-rc3/mount/fstab.c.kzak	2007-07-31 12:39:42.000000000 +0200
+++ util-linux-ng-2.13-rc3/mount/fstab.c	2007-08-13 12:24:40.000000000 +0200
@@ -264,6 +264,27 @@
 	return (ct == 1);
 }
 
+/*
+ * Given the loop file LOOPFILE, and the mount point DIR, check that
+ * same file is already mounted on same directory 
+ *
+ * Don't forget there's 
+ *   /path/loopfile /path/dir loop=/dev/loop0
+ * in mtab for loop devices.
+ */
+int
+is_mounted_same_loopfile(const char *loopfile, const char *dir) {
+	struct mntentchn *mc, *mc0;
+	int ct = 0;
+
+	mc0 = mtab_head();
+	for (mc = mc0->prev; mc && mc != mc0; mc = mc->prev)
+		if (streq(mc->m.mnt_fsname, loopfile) && 
+		    streq(mc->m.mnt_dir, dir))
+			ct++;
+	return (ct == 1);
+}
+
 /* Given the name FILE, try to find the option "loop=FILE" in mtab.  */ 
 struct mntentchn *
 getmntoptfile (const char *file) {
--- util-linux-ng-2.13-rc3/mount/fstab.h.kzak	2007-05-30 10:18:12.000000000 +0200
+++ util-linux-ng-2.13-rc3/mount/fstab.h	2007-08-13 12:24:40.000000000 +0200
@@ -5,6 +5,7 @@
 int mtab_is_writable(void);
 int mtab_does_not_exist(void);
 int is_mounted_once(const char *name);
+int is_mounted_same_loopfile(const char *loopfile, const char *dir);
 
 struct mntentchn {
 	struct mntentchn *nxt, *prev;
--- util-linux-ng-2.13-rc3/mount/mount.c.kzak	2007-08-13 12:23:13.000000000 +0200
+++ util-linux-ng-2.13-rc3/mount/mount.c	2007-08-13 12:29:01.000000000 +0200
@@ -853,7 +853,7 @@
 
 static int
 loop_check(const char **spec, const char **type, int *flags,
-	   int *loop, const char **loopdev, const char **loopfile) {
+	   int *loop, const char **loopdev, const char **loopfile, const char *dir) {
   int looptype;
   unsigned long long offset;
 
@@ -894,6 +894,10 @@
 
       offset = opt_offset ? strtoull(opt_offset, NULL, 0) : 0;
 
+      if (is_mounted_same_loopfile(*loopfile, dir)) {
+        error(_("mount: %s already mounted on %s"), *loopfile, dir);
+	return EX_FAIL;
+      }
       do {
         if (!*loopdev || !**loopdev)
 	  *loopdev = find_unused_loop_device();
@@ -1079,7 +1083,7 @@
        * stale assignments of files to loop devices. Nasty when used for
        * encryption.
        */
-      res = loop_check(&spec, &types, &flags, &loop, &loopdev, &loopfile);
+      res = loop_check(&spec, &types, &flags, &loop, &loopdev, &loopfile, node);
       if (res)
 	  goto out;
   }