Features and status of FreeBSD's Ext2 implementation
Channel: Andrea Ross
Date: 22/05/2014

While FreeBSD has been experiencing a huge momentum with ZFS and UFS2 continues to improve in exciting ways, another UFS variant has seen some advances: Ext2fs is trying to catch up with the new times.

FreeBSD's ext2 implementation has a huge history: it started it's life as part of BSD-Lites for CMU's Mach. It got ported to FreeBSD and after some rust gathering it eventually got important merges from NetBSD's port so now it is completely GPL free and is supporting new features.

Ext2 uses many concepts that are based on UFS but, for good or for bad, Ext2 has never been considered important enough to compete with the local UFS filesystem in the BSDs. Both filesystems have also taken different design decisions over the years and it is not always clear which developments are a clear win on either side. The core of both filesystems is indeed very similar and that similarity has made it relatively easy to adopt in FreeBSD's Ext2fs many enhancements based on FreeBSD's UFS support. Recent years have seen some developments based on successful Google Summer of Code Projects so FreeBSD's driver has support for the directory index and read-only support for extents.

This talk presents the recent developments in ext2fs for FreeBSD and attempts to compare the linux ext2/3/4 features with the typical UFS filesystem in the BSDs.