In any proceeding mentioned in section 1 the heirs of the grantor or devisor if known shall be named as defendants and the same proceedings had thereon as is provided by existing law in actions against known defendants. If the names or addresses of the heirs of any such grantor or devisor are unknown, then proceedings shall be had in such action as may be provided by existing law in proceedings against unknown defendants: Provided, however, That no such action shall be brought within a period of 10 years from the execution of any such conveyance nor within the lifetime of the grantor or devisor thereof.