• Contact: tech-kern
• Duration estimate: 1-2 months

The Ext2 file system is the de-facto standard, Unix-like file system used on Linux installations. Ext2 does not have journaling capabilities, so Ext3 was built on top of it to add them without breaking compatibility with Ext2. Ext3 is now a stable journaled file system used on lots of Linux installations.

NetBSD currently fully supports the Ext2 file system at the kernel level. Unfortunately there is no support for the new features included in Ext3, although Ext3 file systems can be mounted provided that their journal is clean. It would be very nice if NetBSD had Ext3 file system support because the system could immediately gain a journaled file system as well as compatibility with Linux (imagine having both systems installed on a single partition!).

Therefore, the aim of this project is to add Ext3 support to the NetBSD kernel accompanied by any userland code required to support it. This shouldn't be too difficult because, as we already mentioned, Ext2 is implemented in the NetBSD kernel (see src/sys/ufs/ext2fs/) and Ext3 is an extension of it. Also, WAPBL recently added journalling to FFS; maybe parts of the code could be reused.