From mboxrd@z Thu Jan  1 00:00:00 1970
From: Al Viro <viro@ZenIV.linux.org.uk>
Subject: Re: [PATCH 16/24] link_path_walk: kill the recursion
Date: Mon, 20 Apr 2015 22:59:23 +0100
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Cc: Neil Brown <neilb@suse.de>,
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To: Linus Torvalds <torvalds@linux-foundation.org>
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On Mon, Apr 20, 2015 at 02:42:56PM -0700, Linus Torvalds wrote:
> On Mon, Apr 20, 2015 at 2:41 PM, Linus Torvalds
> <torvalds@linux-foundation.org> wrote:
> >
> > And no, we will *never* lift the recursion limit. Not for 1kB, not for
> > 1MB. Never.
> 
> Just to clarify: that's for the "remove restrictions completely".
> Upping it to 32 or 40 would be fine. But not with allocations on the
> stack.

Yep.  There are two restrictions - one on the total amount of symlinks
encountered (40), and another on the depth of nesting (8).  The latter
is due to recursion issues, and with dynamic nd->stack it goes away.
The former, of course, stays, for the reasons you've mentioned - it has
nothing to do with the depth of recursion.