There is no shortage of different file-systems available for Linux. New file-systems continue to come about in the open-source world but ultimately many of them end up not being well maintained or having very limited users and not necessarily innovating enough to make them worthwhile over other alternatives. Given the continued increase in file-systems looking to get into the Linux kernel, such as FTRFS and VMUFAT being some of the most recent and then even having multiple NTFS drivers for Linux, there is now documentation in place to formally lay out criteria for new file-systems to be accepted.

In early May I reported on documentation proposed to lay out requirements for any future file-systems. In particular, the ongoing number of file-systems being added ends up causing a burden on VFS maintainers and other Linux storage/file-system development, especially when file-systems end up being abandoned or poorly maintained.

Among the requirements laid out for in-kernel file-systems is ensuring any new file-system is unique enough over adding to existing implementations, FUSE user-space file-systems being a better fit often for niche use-cases, and more. New file-systems that do innovate enough for mainline also must use modern VFS interfaces, provide the necessary user-space utilities like mkfs and fsck, be testable in a friendly manner, and be covered in the necessary documentation.

Anyhow, the news today is that this documentation has been accepted without objections and is part of the Linux 7.2 kernel. The documentation on adding new file-systems to Linux was merged without fanfare and now in place as the expectations for any new file-system effort with dreams of getting into the mainline kernel.

Those interested can read the new documentation in full via Documentation/filesystems/adding-new-filesystems.rst with the latest Git tree for Linux 7.2.