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Date: Thu, 18 Jun 2009 14:50:02 +0200
From: Olivier Galibert <galibert@pobox.com>
To: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>,
       Linus Torvalds <torvalds@linux-foundation.org>,
       Andreas Dilger <adilger@sun.com>, Alan Cox <alan@lxorguk.ukuu.org.uk>,
       akpm@linux-foundation.org, linux-fsdevel@vger.kernel.org,
       linux-kernel@vger.kernel.org, linux-afs@lists.infradead.org
Subject: Re: [PATCH 00/17] [RFC] AFS: Implement OpenAFS pioctls(version)s
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On Wed, Jun 17, 2009 at 08:28:29PM +0100, David Howells wrote:
> Al Viro <viro@ZenIV.linux.org.uk> wrote:
> 
> > ... so we need a syscall that would do that "drop the caches" operation.
> > _After_ having decided that it's really needed for symlinks.
> 
> If you want to support disconnected operation, then you need a way to (a) lock
> an object in the cache, (b) unlock an object in the cache, (c) pull an object
> into the cache, (d) kick an object out of the cache, (e) ban an object from the
> cache, (f) reserve space in the cache for an object, (g) release the
> reservation on an object and (h) find out the lock/ban/reservation status of an
> object in the cache, and you'd need to support them for _all_ file types,
> including dirs, symlinks, dev files and fifos.  Probably not UNIX sockets,
> though.

If I follow correctly, what you call "object" is "anything a name can
point to in a filesystem", and you need to be able to refer to any of
them without side effects.  So, Al, whay should be used to refer to
them?

  OG.