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: David Howells <dhowells@redhat.com>, miklos@szeredi.hu,
        Jeff Layton <jlayton@redhat.com>, viro@zeniv.linux.org.uk,
        gregkh@suse.de, linux-nfs@vger.kernel.org, leonardo.lists@gmail.com
Date: Fri, 23 Sep 2011 11:01:49 -0400
In-Reply-To: <CA+55aFyd3QB-vfp9Vm6S6_YRCXO9pNE2YavYZhmO+5g6YfdERA@mail.gmail.com>
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On Fri, 2011-09-23 at 07:46 -0700, Linus Torvalds wrote: 
> On Fri, Sep 23, 2011 at 7:34 AM, Trond Myklebust
> <Trond.Myklebust@netapp.com> wrote:
> >
> > My objections are due to the other cases that I pointed out, where
> > Miklos's patch introduced changes in behaviour that IMO are unnecessary
> > and incorrect.
> 
> Guys, it wasn't Mikos' patch that introduced the changes!
> 
> What's so hard to understand here?
> 
> That's why I'm so upset. People talk stupid sh*t about "correct
> behavior" when clearly no such thing *exists*. And people talk about
> Miklos changes as if they were some radical change that changed
> behavior, when they were only a revert to old behavior to begin with
> (at least as far as autofs is concerned)!
> 
> Get a grip, people. Stop over-analyzing things. Stop bothering to
> mention what Solaris does, when the *MUCH* bigger issue is what
> *Linux* has done for years and years.
> 
> Stop saying "we'll revert Miklos patch" in the same sentence where you
> then seem to not even understand that the *original* behavior was the
> one that Miklos patch re-introduced.
> 
> Reverting Miklos patch isn't a revert. THAT is the "semantic change".
> That's the one you need to explain why the heck it would be the right
> thing to do, rather than imply that we'd be going back to some known
> state.

Wrong. Miklos's patch introduces new behaviour that was never present
previously:

- you can now bind mount to the hidden directory.
- you can quotactl the underlying directory.

As I said earlier: adding LOOKUP_DIRECTORY to those operations is not an
option because bind mount needs to work with files too (as long as the
source and target are both files). Ditto with quotactl.


-- 
Trond Myklebust
Linux NFS client maintainer

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