grub_device_iterate (int (*hook) (const char *name))
{
  auto int iterate_disk (const char *disk_name);

  struct part_ent
  {
    struct part_ent *next;
    char *name;
  } *ents;

  int iterate_disk (const char *disk_name)
    {
      grub_device_t dev;

      if (hook (disk_name))
	return 1;

      dev = grub_device_open (disk_name);
      if (! dev)
	return 0;
	.................
	}
	................
}