Among the early pull requests submitted already to Linus Torvalds in advance of the Linux 6.18 merge window opening soon is the Btrfs file-system updates. Btrfs for Linux 6.18 has a few items worth calling out but no major features this cycle.
First up, there is a performance improvement for Btrfs in Linux 6.18 around ready-heavy workloads. Btrfs will now search data checksums in the commit root to avoid locking contention. Btrfs maintainer David Sterba notes this should improve parallelism of read-heavy/low-write workloads. This will also reduce transaction commit time. On a real and reproducer workload, the sync time dropped “from minutes to tens of seconds.”
The other exciting aspect of Btrfs with Linux 6.18 is having initial support for block sizes (BS) greater than the kernel page size (PS). This work has been a long time coming for “BS > PS” support and the initial code is in place for Linux 6.18. But if using Btrfs with a block size greater than page size, currently it’s treated as experimental and lacks direct I/O support, no RAID5 or RAID6 support, and other limitations.
More details on these Btrfs changes submitted ahead of the Linux 6.18 merge window can be found via this pull request.
