With the Linux 6.16 stable kernel potentially being released this coming Sunday, the Linux 6.17 merge window is quickly approaching. Btrfs maintainer and SUSE engineer David Sterba sent out the Btrfs pull request already of new feature code for this copy-on-write file-system in Linux 6.17.
An experimental configuration option is introduced for enabling large folios for data that has the potential of enhancing Btrfs performance. This large folio support for Btrfs is experimental for now as it’s getting close to production but is not too widely tested yet.
There are also new performance improvements to find with Btrfs in Linux 6.17. Btrfs now caches lookup results of the free space bitmap for around a 20% runtime improvement on an empty file creation benchmark.
There are also optimizations to Btrfs that can benefit metadata-heavy workloads. Better sequential read performance on Linux 6.17 is also expected thanks to readahead handling on compressed data. Plus this new code for the next kernel now uses denser keys for the XArray for extent buffers that leads to better packing of nodes and can yield around a 50~70% reduction of leaf nodes.
Btrfs with Linux 6.17 also has updates to its DEFRAG ioctl, restricts writes now to the block device(s) after Btrfs mount, and a variety of bug fixes. There is also improved error handling, continued zone mode improvements, and other code clean-ups.
More details on these Btrfs feature additions and performance improvements that have been readied for Linux 6.17 via this pull request.