An apparatus for enhancing error recovery capability while suppressing increases in response time for a higher-level device, including a management information storage section storing, for each second block, management information relating to a storage medium and information indicating whether a third block corresponding to the second block is valid or invalid; a calculation section performing calculation for each bit position using data of all first blocks in an update target in the case where the management information stored in the management information storage section indicates that the third block corresponding to the second block specified as the update area is invalid and outputs a result of the calculation as calculation data; and a write section writing the calculation data output from the calculation section in the third block associated with the update target and validates the third block in the management information stored in the management information storage section.