BCacheFS filesystem Moves Outside the Linux Kernel
Table of Contents
Background and Removal from Kernel
The future of the BCacheFS filesystem within the Linux kernel was uncertain for several months, marked by disagreements on the Linux Kernel Mailing List (LKML). As of september 20, 2025, BCacheFS has been removed from the kernel and will be distributed as a DKMS (Dynamic Kernel Module support) module instead, fulfilling a promise made by linus Torvalds. Brodie Robertson details the change in a recent video clarification on YouTube.
The decision follows a period of controversy surrounding BCacheFS, including reports of data loss and filesystem corruption among users.
The Controversy with Linus Torvalds
The core of the issue stemmed from disagreements between BCacheFS lead developer kent Overstreet and Linus Torvalds. According to reports, kent Overstreet repeatedly attempted to introduce new features into kernel release candidate branches, accompanied by assertive justifications for doing so.
Linus Torvalds responded by freezing BCacheFS support in the current kernel release and halting all future in-kernel progress. Hackaday covered the ongoing BCacheFS filesystem stability controversy in June 2025 on their website.
Impact on Distributions
the removal of BCacheFS from the kernel impacts how users access the filesystem.SuSE has announced it will disable BCacheFS starting with kernel version 6.17, requiring users to install the DKMS module independently.
Though, some distributions, such as Arch Linux, are expected to include the DKMS module by default. Users of BCacheFS should verify whether their distribution includes the DKMS module to ensure continued functionality.
