Subject: Re: [PATCH] VFS: Suppress automount on [l]stat, [l]getxattr, etc.
From: Trond Myklebust <Trond.Myklebust@netapp.com>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Ian Kent <raven@themaw.net>, Jeff Layton <jlayton@redhat.com>,
        Miklos Szeredi <miklos@szeredi.hu>,
        David Howells <dhowells@redhat.com>, viro@zeniv.linux.org.uk,
        gregkh@suse.de, linux-nfs@vger.kernel.org, leonardo.lists@gmail.com
Date: Mon, 26 Sep 2011 17:31:58 -0400
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On Mon, 2011-09-26 at 14:24 -0700, Linus Torvalds wrote: 
> On Mon, Sep 26, 2011 at 2:13 PM, Trond Myklebust
> <Trond.Myklebust@netapp.com> wrote:
> >
> > LOOKUP_OPEN flags an open intent and will therefore have side-effects on
> > NFSv4.
> 
> Yes, and the actual downside for that is exactly what?
> 
> If you are talking about the bind mount issue, then what is the
> downside with saying "we want the same stronger consistency guarantees
> as for a 'file open' operation"?

A bind mount doesn't actually want us to set up OPEN state on the NFSv4
server and return a fully initialised 'struct file' in the struct
nameidata. If it did, we would already have set the LOOKUP_OPEN flag
together with the accompanying open intent structure in the struct
nameidata.

Ditto for the quotactl().

Cheers
  Trond

-- 
Trond Myklebust
Linux NFS client maintainer

NetApp
Trond.Myklebust@netapp.com
www.netapp.com