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Filesystems maintain a lot of metadata about the files they hold; most of this metadata is for consumption by user space. Some metadata, though, stays buried within the filesystem and is not visible outside of the kernel. One such piece of metadata is the file version count, known as i_version. Current efforts to change how i_version is managed — and to make it visible to user space — have engendered a debate on what i_version actually means and what its behavior should be.

At the 2023 Linux Storage, Filesystem, Memory-Management and BPF Summit, Luis Chamberlain led a plenary session on kernel support for block sizes larger than 4KB. There are assumptions in the current kernel that the block size used by a block-layer device is less than or equal to the system's page size—both are usually 4KB today. But there have been efforts over the years to remove that restriction; that work may be heading toward fruition, in part because of the folio efforts of late, though there are still lots of areas that need attention.

The bcachefs filesystem, and the process for getting it upstream, were the topics of a session led remotely by Kent Overstreet, creator of bcachefs, at the 2023 Linux Storage, Filesystem, Memory-Management and BPF Summit. He has also discussed bcachefs in previous editions of the summit, first in 2018 and at last year's event; in both of those cases, the question of getting bcachefs merged into the mainline kernel came up, but that merge has not happened yet. This time around, though, Overstreet seemed closer than ever to being ready to actually start that process.

Bcachefs is a longstanding out-of-tree filesystem that grew out of the bcache caching layer that has been in the kernel for nearly ten years. Based on a session led by Kent Overstreet at the 2022 Linux Storage, Filesystem, Memory-management and BPF Summit (LSFMM), though, it would seem that bcachefs is likely to be heading upstream soon. He intends to start the process toward mainline inclusion over the next six months or so.

The bcachefs filesystem has been under development for a number of years now; according to lead developer Kent Overstreet, it is time to start talking about getting the code upstream. He came to the 2018 Linux Storage, Filesystem, and Memory-Management Summit (LSFMM) to discuss that in a combined filesystem and storage session. Bcachefs grew out of bcache, which is a block layer cache that was merged into Linux 3.10 in mid-2013.