Re: [PATCH] NFS using CacheFS

[David Howells <dhowells@redhat.com>]

> This is my one and only real gripe about it. The posix mount option is
> clearly documented, so we really cannot play around with it. Why can't
> you just add a separate cachefs flag?

That's just for the prototype. It will be changed later. It's also a stand-in
for the superblock un-aliasing patch.

> I'm a bit worried about the use of the raw IP address in
> nfs_cache_server_match(). It seems to me that when we add the NFSv4.1
> support for trunking over several different transport mechanisms (RDMA,
> IPv4/v6 etc) on the same mountpoint, then we may end up with a problem.  We
> can probably leave it in for now, but later we may want to consider
> switching to using server->hostname or something equivalent.

There needs to be some way of matching NFS file handle sets in the cache if
you want persistant caches. The only way I could see was to use IP addr and
port number for NFS.

However, changing this later is trivial. If you bump the version number in the
netfs definition, then cachefs will nuke existing data in the cache that isn't
of the expected format.

David