I've whipped up a patch to split CacheFS into two: (1) FS-Cache This is a general cache manager that the interested netfs's talk to. It is supplied with a number of cache backends over which it distributes the operations from the netfs's. (2) CacheFS This is then made into a cache backend. The act of mounting a block device as cachefs causes the space contained therein to be made available through FS-Cache. To give you a clearer idea of what I'm thinking, this diagram might help: +---------+ | | +-----------+ | NFS |--+ | | | | | +-->| CacheFS | +---------+ | +----------+ | | /dev/hda5 | | | | | +-----------+ +---------+ +-->| | | | | | |--+ +-------------+ | AFS |----->| FS-Cache | | | | | | |----->| Cache Files | +---------+ +-->| | | /var/cache | | | |--+ +-------------+ +---------+ | +----------+ | | | | | +-------------+ | ISOFS |--+ | | | | | +-->| ReiserCache | +---------+ | / | +-------------+ So, for example, you might have a block device mounted with CacheFS as one of your backends, the traditional bunch of cache files as another backend and some sort of Reiser4 plug-in as a third backend. A netfs only has to be modified to take account of FS-Cache. It then shouldn't need to be modified further to support each different type of cache. David