That undo program is called nilfs2, which unfortunately never became popular. I'll simply quote the kernel docs: > NILFS2 is a log-structured file system (LFS)

That undo program is called nilfs2, which unfortunately never became popular. I'll simply quote the kernel docs: > NILFS2 is a log-structured file system (LFS) supporting continuous snapshotting. In addition to versioning capability of the entire file system, users can even restore files mistakenly overwritten or destroyed just a few seconds ago. https://docs.kernel.org/filesystems/nilfs2.html https://docs.kernel.org/filesystems/nilfs2.html https://wiki.archlinux.org/title/NILFS2 https://wiki.archlinux.org/title/NILFS2 https://en.wikipedia.org/wiki/NILFS https://en.wikipedia.org/wiki/NILFS