Projects / Extended Attributes and ACLs for Linux

Extended Attributes and ACLs for Linux

Linux, in the tradition of UNIX-like operating systems, implements file system permissions using a rather coarse scheme. While this is sufficient for a surprisingly large set of applications, it is too inflexible for many other scenarios. For that reason, all the major commercial UNIX operating systems have extended this simple scheme in one way or the other. This is an effort to implement POSIX-like Access Control Lists for Linux. Access Control Lists are built on top of Extended Attributes, which can also be used to associate other pieces of information with files such as Filesystem Capabilities, or user data like mime type and search keywords.

Operating Systems

Recent releases

  •  10 Mar 2002 23:58

    Release Notes: The on-disk format has changed between versions 0.7 and 0.8. Official extended attribute system calls have been assigned, and the ext2/ext3 and XFS file systems are now compatible at the system call level. The kernel patches have been rewritten, and are now much better structured. RPM versions of all packages are available.

    •  28 Oct 2001 17:11

      Release Notes: This version contains ext3 support and much more.

      •  16 Aug 2001 19:59

        No changes have been submitted for this release.

        •  04 Mar 2001 19:05

          Release Notes: This release contains support for the 2.4.2 kernel, and for fileutils-4.0.41. Several bug fixes were made in the kernel patches and ACL utilities.

          •  22 Oct 2000 17:29

            Release Notes: Support for sharing extended attribute blocks among ext2 inodes (this required some changes in the ext2 on-disk format), a fix for the ACL and NFSv2 interaction problem (too many permissions granted in some cases), and a complete review of the code.


            Project Spotlight


            A Fluent OpenStack client API for Java.


            Project Spotlight

            TurnKey TWiki Appliance

            A TWiki appliance that is easy to use and lightweight.