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Date: Mon, 5 Mar 2018 07:55:50 -0800
From: Christoph Hellwig <hch@infradead.org>
To: "Robert N. M. Watson" <robert.watson@cl.cam.ac.uk>
Cc: Justin Cormack <justin@specialbusservice.com>,
 "<cl-capsicum-discuss@lists.cam.ac.uk>" <cl-capsicum-discuss@lists.cam.ac.uk>, 
 freebsd-hackers@freebsd.org, Mariusz Zaborski <oshogbo@freebsd.org>
Subject: Re: [capsicum] unlinkfd
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With my Linux hat I'd much prefer using the AT_EMPTY_PATH flag that
Linux already supports for a few *at calls to operate on the dirfd
fd.  But it seems like neither FreeBSD nor anyone else picked up that
flag, so it might be a bit of a hard sell.

FreeBSD bugzilla related to AT_EMPTY_PATH and the lack of it for
unlinkat even in Linux:

https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=197778

Linux bugzilla:

https://bugzilla.kernel.org/show_bug.cgi?id=93441

If you are interested in bringing this to FreeBSD that might be reason
enough for me into looking into a Linux implementation as well.