Index: util-linux-ng-2.14.2/mount/umount.c
===================================================================
--- util-linux-ng-2.14.2.orig/mount/umount.c	2009-02-11 17:00:35.000000000 +0100
+++ util-linux-ng-2.14.2/mount/umount.c	2009-02-12 13:09:44.000000000 +0100
@@ -465,6 +465,42 @@ get_value(const char *list, const char *
 	return 0;
 }
 
+#define LOOP_DEV_PATH "/dev/loop"
+/* check if mc contains a loop device which is associated
+ * with the file in fs
+ */
+static int
+valid_loop(struct mntentchn *mc, struct mntentchn *fs)
+{
+	unsigned long long offset=0;
+	char *p;
+
+	/* 1. check if it begins with /dev/loop */
+	if (strncmp(LOOP_DEV_PATH, mc->m.mnt_fsname, sizeof(LOOP_DEV_PATH)-1) != 0)
+		return 0;
+	
+	/* 2. check for loop option in fstab */
+	if (!contains(fs->m.mnt_opts, "loop"))
+		return 0;
+
+	/* 3. check for offset option in fstab */
+	if (p=get_value(fs->m.mnt_opts, "offset="))
+		offset = strtoull(p, NULL, 10);
+
+	/* 4. check association */
+	if (loopfile_used_with(mc->m.mnt_fsname, fs->m.mnt_fsname, offset)) {
+		if (verbose > 1)
+			printf(_("device %s is associated with %s\n"),
+			       mc->m.mnt_fsname, fs->m.mnt_fsname);
+		return 1;
+	} else {
+		if (verbose > 1)
+			printf(_("device %s is not associated with %s\n"),
+			       mc->m.mnt_fsname, fs->m.mnt_fsname);
+		return 0;
+	}
+}
+
 static int
 umount_file (char *arg) {
 	struct mntentchn *mc, *fs;
@@ -530,14 +566,18 @@ umount_file (char *arg) {
 		   the pair (spec,file) in fstab. */
 		fs = getfs_by_specdir(mc->m.mnt_fsname, mc->m.mnt_dir);
 		if (!fs) {
-			if (!getfs_by_spec (file) && !getfs_by_dir (file))
+			fs = getfs_by_dir(file);
+			if (!getfs_by_spec (file) && !fs)
 				die (2,
 				     _("umount: %s is not in the fstab "
 				       "(and you are not root)"),
 				     file);
-			else
+
+			/* spec could be a file which is loop mounted */
+			if (fs && !valid_loop(mc, fs))
 				die (2, _("umount: %s mount disagrees with "
 					  "the fstab"), file);
+
 		}
 
 		/*