Patent ID: 8266176

Claim:
A storage system, comprising: a storage device in which a file system is created; and a file access controller for determining an executability of an access request to a file based on access control information showing whether access to a file stored in the file system is permitted, wherein the file is configured from a data area, a basic attribute area, and an extended attribute area, wherein the access control information comprises: second access control information stored in the extended attribute area of the file as a variable length area, the second access control information including a plurality of information of access rights showing a type of a plurality of access requests to be permitted or rejected for each user or group that executes the access request to the file; and first access control information stored in the basic attribute area of the file as a fixed length area, the first access control information being at least a partial information of the access right included in the second access control information, and the first access control information showing one or more types of the access requests to be permitted or rejected for the user or the group, wherein the file access controller is configured to: (A) execute, upon receiving the access request to the file, a first determination processing of determining whether access to the file is permitted by using the first access control information stored in the basic attribute area of the file, wherein the first access control information includes said information converted from the information of the access right included in the second access control information; and (B) execute a second determination processing of determining whether the access to the file is permitted based on the second access control information stored in the extended attribute area of the file when the storage system cannot determine via the first determining processing whether access to the file is permitted.