CLUSTERED FILESYSTEMS FOR MIX OF TRUSTED AND UNTRUSTED NODES

摘要

A cluster of computer system nodes share direct read/write access to storage devices via a storage area network using a cluster filesystem. At least one trusted metadata server assigns a mandatory access control label as an extended attribute of each filesystem object regardless of whether required by a client node accessing the filesystem object. The mandatory access control label indicates the sensitivity and integrity of the filesystem object and is used by the trusted metadata server(s) to control access to the filesystem object by all client nodes.

主权项

1. A method for controlling access to data, the method comprising:
receiving a request by a server from a first client node of a plurality of client nodes to update an access control list attribute; sending a message to one or more other client nodes of the plurality of client nodes that have a read token of one or more read tokens, wherein the message sent to the one or more other client nodes instructs the one or more other client nodes to release the one or more read tokens, wherein the releasing of the one or more read tokens invalidates information cached at the one or more other client nodes regarding the access control list attribute; updating the content of the access control list attribute according to the received request; receiving a request from a second client node of the plurality of client nodes for a current content of an access control list, wherein the current content of the access control list includes the updated access control list attribute; and providing a read token and the current content of the access control list to the second client node after receiving the request from the second client node, wherein the read token provided to the second client node identifies that the current content of the access control list provided to the second client node is valid.