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Date: Mon, 20 Apr 2015 20:22:53 +0100
From: Al Viro <viro@ZenIV.linux.org.uk>
To: Andreas Dilger <adilger@dilger.ca>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
        Oleg Drokin <oleg.drokin@intel.com>, Neil Brown <neilb@suse.de>,
        LKML <linux-kernel@vger.kernel.org>,
        Linux Filesystem Mailing List <linux-fsdevel@vger.kernel.org>
Subject: Re: [PATCH 01/24] lustre: rip the private symlink nesting limit out
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On Mon, Apr 20, 2015 at 01:08:16PM -0600, Andreas Dilger wrote:
> On Apr 20, 2015, at 12:12 PM, Al Viro <viro@ZenIV.linux.org.uk> wrote:
> > 
> > From: Al Viro <viro@zeniv.linux.org.uk>
> > 
> > Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
> 
> Al, the patch itself looks good, thanks.
> 
> However, if this is applied at the start of the series it could
> allow tests to easily cause a stack overflow during a bisection (I
> don't think users would see a kernel in the middle of the series).
> 
> Could this be converted over to checking nd->link_count along with
> the [02/24] patch until closer to the end of the series when the
> recursion has been removed?

Er...  You do realize that struct nameidata is opaque for anything outside
of fs/namei.c and has been that way for a while now?  Sure, we can export
a helper that would return that and rip it out in the end of the series,
but...

> It isn't fatal if that doesn't happen, since this whole series should
> land at one time and the chance of testing Lustre symlinks right
> in the middle of the series is low, just something I thought when
> reviewing the patch.