An access control attribute that can be established for an extent that is provided in a storage device may be any access control attribute signifying write permission, read permission, and write prohibition, but an access control attribute signifying read prohibition is not supported. In cases where a read request for read target data is received from a communication device that transmits the read request, the data processing system reads read target data from a read source extent without retrieving an access control attribute of the read source extent according to the read request from among a plurality of access control attributes.