Re: filesystem namespace regions, or making mountd less bozotic

[David Laight <david%l8s.co.uk@localhost>]

On Wed, Dec 05, 2012 at 09:29:06PM +0000, David Holland wrote:
> I am tired of PR 3019 and its many duplicates, so I'd like to see a
> scheme that allows managing arbitrary subtrees of the filesystem
> namespace in a reasonably useful manner.
> 
> The immediate application is nfs exports and mountd; however, I expect
> the resulting mechanism will also be useful for handling chroots and
> possibly also inotify-type mechanisms.

Haven't you forgotten about 'file handles'.
Since they refer to files you don't know anything about the containing
directory.

In the old days NFS had the following 'rules':
1) If you export part of a filesystem, you export all of it.
2) If you give anyone access, you give everyone access.
3) If you give anyone write access, you give everyone write access.

I suspect 2 & 3 are no longer true (in NetBSD) as nfs checks the
permissions, not just mountd.
1 is true if clients can 'fake up' valid file handles (used to be very
easy).

        David

-- 
David Laight: david%l8s.co.uk@localhost