FSCRYPT Sees Cleanup With Linux 7.3 To Open Door For More Features Like Btrfs Encryption

FSCRYPT is the Linux file-system encryption framework for supporting per-directory, transparent encryption. FSCRYPT so far is used by the likes of EXT4, F2FS, and CephFS. For Linux 7.3 there is an important clean-up to the FSCRYPT code to simplify it while also opening the door for new features moving forward into future kernel versions.

Eric Biggers sent out the FSCRYPT updates this week for Linux 7.3, which are already merged and headlined by a significant clean-up. This work removes redundant implementations of the single file encryption code where as EXT4 and F2FS had each been carrying their own implementation. In place the blk-crypto implementation for file contents encryption is used, which also allows using inline encryption hardware where supported.

Removing the redundant implementation allows for clearing out a lot of FSCRYPT code. Plus makes it easier supporting new features moving forward. Among those features noted by Eric Biggers of Google is for IOmap support, large folios, and supporting FSCRYPT encryption with Btrfs.

For Linux 7.3 this rework also now allows direct I/O to work on encrypted files even without the "inlinecrypt" mount option rather than falling back to buffered I/O.

More details on this FSCRYPT work now merged for Linux 7.3 via this pull request.