File Accessibility

The XFile methods canRead() and canWrite() are implemented within the NFS classes with code that checks the permission bits of the file attributes against the user's UID. While this technique is used by all NFS version 2 clients, it may sometimes return misleading result if file access is controlled on the server with an Access Control List (ACL) since the effects of the ACL cannot always be represented by an equivalent set of permission bits. Version 3 supports an ACCESS request that allows the client to request the server do the access check subject to the ACL. The result from ACCESS is always an accurate indication of the file access permitted the user. The NFS client does not currently implement the ACCESS check but will support it in the next release.