There's been some Friday night kernel drama on the Linux kernel mailing list... Linus Torvalds has expressed regrets for merging the Bcachefs file-system and an ensuing back-and-forth between the file-system maintainer.
On Friday a set of fixes were submitted for merging into the current Linux 6.11 cycle. There were little fixes plus two big "fixes" around an rhashtable conversion and a new data structure for managing free lists in the BTree key cache. That later one eliminates the BTree key cache lock and avoids some locking contention that can appear in some multi-threaded workloads.
But this "fixes" pull request touches more than one thousand lines of code and we're now more than half-way through the Linux 6.11 cycle. This is far from the first time that big "fixes" pulls for Bcachefs have been submitted post merge window and not the first time that it's not strictly bug fixes but also heavier more feature-like additions being made via fixes pull requests. Linus Torvalds had enough and responded to the pull request.
I don't understand any of this on a technical level but it is interesting to see play out nonetheless.