Btrfs In Linux 6.8 Transitions Metadata Processing To Using Folios

While not as notable as the Bcachefs additions, more work on XFS online repair, and other file-system updates for Linux 6.8, the Btrfs file-system driver changes for Linux 6.8 were merged last week.

This round of Btrfs updates for the new kernel aren't too exciting for end-users but do include transitioning over to the new Linux mount API. That's some code clean-ups in the process and then the other big set of Btrfs work for this kernel is converting metadata processing from using extent buffers to now using folios.

More Linux kernel code continues moving over to the memory folios code. Folios is now used by Btrfs in place of extent buffers but it's known that the performance can currently drop by a few percent for metadata-heavy workloads. Btrfs data hasn't been converted over.

The Btrfs pull request mentions that large folios aren't yet enabled pending more testing but it's just "one patch away" now at this point.

Most of the other Btrfs patches are small and relatively uninteresting for end-users. One bit that may stand out though is temporary pages used for compression are now cached and attached to the shrinker, which "may slightly improve performance" according to the Git pull.