Linux Developers Discuss Deprecating & Removing ReiserFS

Besides no discussion in years over possibly upstreaming Reiser4 nor have any been brought up about eventually trying to mainline Reiser5, it looks like the original and feature-rich for its original time ReiserFS file-system could be on its way out of the Linux kernel in 2022.

ReiserFS was introduced 21 years ago as the Linux kernel's first journaling file-system to be mainlined and offered innovative features for its time among early open-source file-systems. For a time ReiserFS was used by default on SUSE Linux and during the Namesys times was continuing to see active feature development. But since lead ReiserFS developer Hans Reiser was convicted of murdering his wife a decade and a half ago, there hasn't been much work on ReiserFS (or Reiser4) besides notably the work of former Namesys developer Edward Shishkin. While Shishkin has been pushing forward with Reiser4/Reiser5 out-of-tree, ReiserFS has basically been left to code rot with diminishing user interest and no company seeming to want to get involved with it given its connection to Hans Reiser. Plus these days EXT4, XFS, and Btrfs are all better choices and even OpenZFS.

It's been a long time since ReiserFS was last relevant to the Linux masses.

Started in a discussion this week by longtime kernel developer Matthew Wilcox, there is a discussion over removing ReiserFS. The motivation by Wilcox for removing ReiserFS is due to kernel infrastructure changes he is pursuing but ReiserFS being the only user left of a particular flag blocking his work. Plus he notes ReiserFS has been barely seen new work in recent years besides Syzbot fixes and other tree-wide code changes. There doesn't appear to be any user-spotted bug fixes since at least 2019.

Following that thread, Edward Shishkin posted a patch for ReiserFS to get rid of the AOP_FLAG_CONT_EXPAND flag, which is what motivated Wilcox to start the discussion in the first place. However, other kernel developers have chimed in with interest to deprecate / removal the file-system. It's possible ReiserFS will be deprecated for a few kernel releases prior to its actual removal, which has been common practice for kernel feature removal.

When is the last time you used the ReiserFS file-system? (It might get removed from mainline #Linux kernel.)

— Phoronix (@phoronix) February 22, 2022

Judging from the comments so far, it's looking like ReiserFS may stand to be deprecated in 2022 for its eventual removal in a future mainline Linux kernel release. Dave Chinner also suggested possibly looking at deprecating with plans to remove other old Linux file-systems that aren't maintained and not Year 2038 compliant.