Re: [PATCHv4 man-pages 3/3] open.2: describe O_BENEATH flag

From: Andy Lutomirski <luto@amacapital.net>
To: David Drysdale <drysdale@google.com>
Cc: Michael Kerrisk-manpages <mtk.manpages@gmail.com>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	Alexander Viro <viro@zeniv.linux.org.uk>,
	Kees Cook <keescook@chromium.org>,
	"Eric W. Biederman" <ebiederm@xmission.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Meredydd Luff <meredydd@senatehouse.org>,
	Will Drewry <wad@chromium.org>,
	Jorge Lucangeli Obes <jorgelo@google.com>,
	Ricky Zhou <rickyz@google.com>, Lee Campbell <leecam@google.com>,
	Julien Tinnes <jln@google.com>,
	Mike Depinet <mdepinet@google.com>,
	James Morris <james.l.morris@oracle.com>,
	Paolo Bonzini <pbonzini@redhat.com>,
	Paul Moore <paul@paul-moore.com>,
	Christoph Hellwig <hch@infradead.org>,
	Dave Chinner <david@fromorbit.com>,
	Linux API <linux-api@vger.kernel.org>,
	linux-arch <linux-arch@vger.kernel.org>,
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	fstests <fstests@vger.kernel.org>
Subject: Re: [PATCHv4 man-pages 3/3] open.2: describe O_BENEATH flag
Date: Fri, 14 Aug 2015 07:17:50 -0700	[thread overview]
Message-ID: <CALCETrXLhp6-dVq8TS0_vSQBJieP-SrabhoDJE0PZ8KpMz1m0A@mail.gmail.com> (raw)
In-Reply-To: <CAHse=S9HdriyqKrQRj=x3CpEFftPgVFX7p8B9efu9_mQtEvJSA@mail.gmail.com>

On Fri, Aug 14, 2015 at 2:29 AM, David Drysdale <drysdale@google.com> wrote:
> On Fri, Aug 14, 2015 at 6:33 AM, Michael Kerrisk (man-pages)
> <mtk.manpages@gmail.com> wrote:
>> On 13 August 2015 at 19:38, Andy Lutomirski <luto@amacapital.net> wrote:
>>> On Thu, Aug 13, 2015 at 2:32 AM, David Drysdale <drysdale@google.com> wrote:
>>>> Signed-off-by: David Drysdale <drysdale@google.com>
>>>
>>> What's the behavior wrt fcntl(F_GETFL, etc)?
>>
>> I would presume that O_BENEATH is one of the so-called "file creation
>> flags". See this paragraph of the DESCRIPTION:
>>
>>        In addition, zero or more file creation  flags  and  file  status
>>        flags  can be bitwise-or'd in flags.  The file creation flags are
>>        O_CLOEXEC, O_CREAT, O_DIRECTORY,  O_EXCL,  O_NOCTTY,  O_NOFOLLOW,
>>        O_TMPFILE,  O_TRUNC,  and  O_TTY_INIT.  The file status flags are
>>        all of the remaining flags listed below.  The distinction between
>>        these  two  groups  of flags is that the file status flags can be
>>        retrieved and (in some cases) modified; see fcntl(2) for details.
>>
>> David, presuming this is correct (I can't see how O_BENEATH could be a
>> "file *status* flag"), your patch should also add O_BENEATH to the
>> list in that paragraph.
>
> Yeah, O_BENEATH makes sense as a file creation flag; I'll add it
> to that list -- thanks for spotting.

Should there be a test that you can't clear O_BENEATH with F_SETFL?

--Andy