Re: [Linux-cachefs] Re: [PATCH] NFS using CacheFS

From: David Howells
Date: Wed Oct 13 2004 - 05:42:15 EST



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
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/