Following the Bcachefs pull requests being rejected during the Linux 6.13 cycle by the kernel’s Code of Conduct committee, the Linux 6.14 kernel cycle is kicking off with a big pull request so that the upstream kernel can get back into sync with the latest development code for this cycle. This pull also contains the last anticipated major on-disk format upgrade prior to the removal of the “experimental” flag for this copy-on-write file-system.
Bcachefs lead developer Kent Overstreet explained in the today’s pull request for Linux 6.14:
“Lots of scalability work, another big on disk format change. On disk format version goes from 1.13 to 1.20.
Like 6.11, this is another big and expensive automatic/required on disk format upgrade. This is planned to be the last big on disk format upgrade before the experimental label comes off. There will be one more minor on disk format update for a few things that couldn’t make this release.”
For the Linux 6.14 kernel the Bcachefs file-system is set to see some regression fixes, fsck time on large file-systems is much faster, more work on making the file-system self-healing, various reflink repair changes, improvements to the re-balance data path, and the various on-disk format changes.
The faster fsck time with large Bcachefs file-systems is described as being “multiple orders of magnitude” faster:
“fsck time on large filesystems is improved by multiple orders of magnitude. Previously, 100TB was about the practical max filesystem size, where users were reporting fsck times of a day+. With the new changes (which nearly eliminate backpointers fsck overhead), we fsck’d a filesystem with 10PB of data in 1.5 hours.”
See this pull request for more details on these changes for Linux 6.14. Now awaiting pulling by Linus Tovalds assuming no code quality concerns raised or any intervention by the CoC committee.
