Trond Myklebust <trond.myklebust@xxxxxxxxxx> wrote:
> That said, David & co.: why did you choose not to use something similar
> to the Solaris syntax for cachefs?
Well...
(1) when I wrote cachefs I didn't know that Solaris had such a thing
(2) I don't know what Solaris syntax is - I've seen one example, and that
didn't make a lot of sense
(3) my way doesn't involve any changes to userspace programs such as mount
> The "layered filesystem" syntax has the advantage that it would avoid
> entirely the need to change the NFS mount syntax,
And the disadvantage that we'd have to change the VFS to support it, I
think. I don't know how this "layered filesystem" thing operates or is used,
so I'm guessing.
> and would make it easier to port cachefs to cifs etc.
I doubt it. The netfs still has to interact with fscache internally to decide
how match netfs files to cache files, which is what most of the interface is
about; and to push/pull pages to/from the cache (this bit could possibly be
made transparent, but I'm not sure how you'd do it on Linux with the present
VM & VFS interfaces).
David
