Linux 5.17 Lands Big Rewrite To FS-Cache & CacheFiles Driver Code

Being worked on since early 2020 by Red Hat's David Howells has been a rewrite to Linux's FS-Cache and CacheFiles code focusing on making it smaller and simpler while also presenting possible memory/performance advantages. That major rewrite has been merged now for Linux 5.17.

The FSCACHE is the general purpose cache code used by network file-systems and CacheFiles provides a caching back-end for mounted file-systems. This affects network file-systems like 9p, AFS, Ceph, and NFS. This Red Hat led rewrite to the code simplifies the code and cleans a lot of things up in the process as well as being more future-proof. Indeed with the rewrite merged on Wednesday there were 13k lines of existing code removed while adding just 7.2k lines of new code.

More details on this big FS-Cache/CacheFiles rewrite via the pull request.