Linux Log-structured Filesystem Project

This project is on hold (probably forever). Luckily, someone else has made a better attempt at a Linux LFS system. Check out Christian Czezatke's LFS project.

Kees' Psuedo Logging Filesystem (the Linux LFS Project) is making it's way into reality. I've started thinking about the code during class and while sleeping, so eventually something will come to fruition.

I'm keeping notes on what I'm researching in the Linux VFS Kernel, so I can possible write a filesystem-writing HOWTO for the Linux Documentation Project.

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Linux Documentation Project

Last modified: 06 May 1998

What IS a log-structured or journaling filesystem, anyway?
Where can I find an LFS project that isn't stalled?

Resources

Papers (gzip'd PostScript files)
- Extent-like Performance from a UNIX File System 1991 McVoy & Kleiman
- A Comparison of FFS Disk Allocation Policies Smith & Seltzer
- Beating the IO Bottleneck: A Case for Log-Structured File Systems Ousterhout & Douglis
- The LFS Storage Manager 1990 Rosenblum & Ousterhout
- Experiences with Implementing a Log-Structured File System 1992
- An Implementation of a Log-Structured File System for UNIX 1993 Seltzer, Bostic, McKusick, & Staelin
- The Design and Implementation of a Log-Structured File System 1991 Rosenblum & Ousterhout
- The Design and Implementation of a Log-Structured File System 1992 Rosenblum's Thesis
- Implementation of the BSD-LFS 1995? Seltzer
Sites
Books
- "UNIX Internals" (1996, Prentice Hall) Uresh Vahalia
- "System Administration 2nd Edition" (1995, O'Reilly) Aeleen Frisch
My Code
- Some of my random notes from the Linux kernel
- The start of my outline for the Kees' Psudo Logging filesystem

Project

The KPL Plan

Learn about standard filesystems
Learn about logging filesystems
Learn about the Linux Kernel VFS
Design the LFS
- Finish new Linux buffer-cache routines
- Finish superblock version checking routines
Write support utility: "mklfs" to make the filesystem (basics done)
Write mountable kernel fs module (started)
Write support utility: "edlfs" to edit the filesystem
Write read-only kernel fs module (super, inode, & dir functions)
Write a read/write kernel fs module (super, inode, & directory functions)
Write user-level segment cleaner utility: "cleanerd"
Add file functions to fs module
Add symlink functions to fs module
Start beta-testing
Add roll-forward code to read_super function in fs module
Add "advanced" features like mmap, etc. to fs module
Write support utility: "fsck.lfs" to repair truely damaged filesystems
Add ext2-like extensibily
Write "unrm" utility
And beyond... defragmentation code? more utils?

Status: see highlighted line in the Plan. We're always improving/breaking previously finished parts of the plan. The highlighted stuff is what's currenlty in the development stages.
Planned Completion Date: sometime in 1998 for orignal beta-test release of KPL

The People

List Serve Maintainer: Sean McAdam
Documentation: Pete Deuel
Beta Testers: Fozzy Dressel, Diaz
Programmers: Kees Cook
WWW Page Maintainer: Kees Cook

Contact Info

List Serve: linux-ljfs@majordomo.ibasys.net
Web Page: http://outflux.net/projects/lfs

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