Btrfs and Squashfs merged into Linux kernel
The Btrfs and Squashfs file systems have been merged into the Linux kernel main development branch and, barring any problems, should appear in the 2.6.29 version of the kernel, currently in development. The two new file systems are good examples of where the Linux kernel developers see the future of Linux; running on both smaller and larger systems.
Squashfs is a compressed read-only file system that is ideal for archival usage and for embedded systems, where resources are limited. Squashfs has been used in several Linux distributions, but has been developed away from the kernel development process. Squashfs is already a stable file system, so it should integrate easily into 2.6.29.
Btrfs is a "next generation file system" which is destined to be a future default Linux file system. In contrast to Shashfs, Btrfs is still very much in development, and in the meantime work continues on Ext4 as a more immediate replacement for the current Ext2 and Ext3 file systems, which have a number of limitations. Ext4 has completed main development and was merged into 2.6.28 to focus the further development required for a future default file system. Originally developed by Chris Mason at Oracle, Btrfs has a number of advanced features, with extent-based storage, file systems that can be divided into sub-volumes, on-line integrity checking and fast off-line checking.