File speed-umount.patch of Package util-linux

--- util-linux-ng-2.14.1/mount/umount.c
+++ util-linux-ng-2.14.1/mount/umount.c
@@ -382,6 +382,7 @@
 umount_all (char *types, char *test_opts) {
      struct mntentchn *mc, *hd;
      int errors = 0;
+     int umount_count = 0;
 
      hd = mtab_head();
      if (!hd->prev)
@@ -391,10 +392,11 @@
 	      && matching_opts (mc->m.mnt_opts, test_opts)) {
 	       errors |= umount_one (mc->m.mnt_fsname, mc->m.mnt_dir,
 				     mc->m.mnt_type, mc->m.mnt_opts, mc);
+	       umount_count++;
 	  }
      }
-
-     sync ();
+     if (umount_count > 0)
+       sync ();
      return errors;
 }