According to technology media Phoronix , the long-developed Bcachefs filesystem driver was submitted to Linux 6.5, but due to various technical issues and developer "infighting", this driver was not merged during this development cycle.
Bcachefs is a copy-on-write (CoW) file system derived from the block cache Bcache of the Linux kernel. A few months ago, Bcachefs' patch set was officially submitted for review and is expected to be included in the kernel.
The developers hope to provide performance similar to XFS/EXT4, as well as features similar to Btrfs and ZFS. Its lead developer states that Bcachefs has "too many features to list" and known bugs are "too many to list".
Last month, the Linux kernel developers started a stimulating discussion on the "Bcachefs filesystem driver" mailing list , and the atmosphere gradually became tense (lots of unfriendly messages). But this change does not originate in the filesystem itself, but in code changes required outside of the kernel module itself .
Now, Linus Torvalds himself has begun to personally review the submitted code and express his views on the relevant situation.
Linus finished a review of the Bcachefs code yesterday. He expressed concerns about the partial locking code , and believes that some of the Bcachefs prerequisite code should be entered through the respective subsystem/maintainer branch instead of being put into a large PR.
Overall, Linus' stance on the state of the Bcachefs merge basically boils down to:
As it stands, I have nothing against bcachefs itself.
I'm only concerned with bcachefs internal stuff because I really, really want someone to be able to look at those six locks, but at the same time, as long as this stuff is purely bcachefs internal and doesn't affect anything else, I'm not too worried.
In fact, what bothers me the most is the personal arguments I see . I do not know what to do. Due to Christian's objection, I don't actually want to merge this, since we have a responsible vfs maintainer.
So even leaving aside the "I think preconditions should be added separately, or at least explicitly noted", these arguments must be resolved.
Visit the mailing list for Linus' full commentary.
Bcachefs lead developer Kent Overstreet has indicated that he will be recommitting to Linux 6.6, so let's wait and see if the Bcachefs issue and developer debate cools down in the coming weeks.
- Further reading: The next-generation CoW file system Bcachefs enters the Linux kernel