From mboxrd@z Thu Jan  1 00:00:00 1970
From: NeilBrown <neilb@suse.de>
Subject: Re: O_CREAT|O_DIRECTORY on nonexisting file with ext4 not
 posix-compliant
Date: Tue, 16 Dec 2014 13:49:26 +1100
Message-ID: <20141216134926.70253edb@notabene.brown>
References: <2ECE9D9EEF1F524185270138AE23265947D57FA7@S0MSMAIL112.arc.local>
Mime-Version: 1.0
Content-Type: multipart/signed; micalg=pgp-sha1;
 boundary="Sig_/X8wW8WzhkJOWmeK9gC74092"; protocol="application/pgp-signature"
Cc: "linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>,
	"Michael Kerrisk (man-pages)" <mtk.manpages@gmail.com>
To: Fiedler Roman <Roman.Fiedler@ait.ac.at>
Return-path: <linux-fsdevel-owner@vger.kernel.org>
Received: from cantor2.suse.de ([195.135.220.15]:42250 "EHLO mx2.suse.de"
	rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
	id S1752518AbaLPCtf (ORCPT <rfc822;linux-fsdevel@vger.kernel.org>);
	Mon, 15 Dec 2014 21:49:35 -0500
In-Reply-To: <2ECE9D9EEF1F524185270138AE23265947D57FA7@S0MSMAIL112.arc.local>
Sender: linux-fsdevel-owner@vger.kernel.org
List-ID: <linux-fsdevel.vger.kernel.org>

--Sig_/X8wW8WzhkJOWmeK9gC74092
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: quoted-printable

On Mon, 15 Dec 2014 17:39:09 +0000 Fiedler Roman <Roman.Fiedler@ait.ac.at>
wrote:

> Hi,
>=20
> It seems that the open syscall is not POSIX-compliant when using both
> O_CREAT|O_DIRECTORY. This was discussed in [1] with a reference to the PO=
SIX
> documentation.

Given that O_DIRECTORY is not part of POSIX, I don't think that
POSIX-compliance is an issue here.

However the implementation does seem to differ from the Linux documentation.

I suggest you submit a patch to the manpages project to change

  If  pathname  is  not a directory

to

  If  pathname exists and is  not a directory

That should fix the problem.

NeilBrown


>=20
> A simple test program is:
>=20
> #include <fcntl.h>
> #include <stdio.h>
> #include <sys/stat.h>
>=20
> int main(int argc, char **argv) {
>   int fd;
>   struct stat statBuf;
>   int result;
>=20
>   fd=3Dopen("xxx", O_RDWR|O_CREAT|O_DIRECTORY, 0600);
>   result=3Dfstat(fd, &statBuf);
>   if(result) {
>     fprintf(stderr, "Stat failed\n");
>     return(1);
>   }
>   fprintf(stderr, "New element type is %d\n", S_ISDIR(statBuf.st_mode));
>   return(0);
> }
>=20
>=20
> Kind Regards,
> Roman
>=20
> [1] http://www.openwall.com/lists/oss-security/2014/11/26/10
>=20
>=20
> DI Roman Fiedler
> Scientist
> Digital Safety & Security Department
> Assistive Healthcare Information Technology
>=20
> AIT Austrian Institute of Technology GmbH
> Reininghausstra=C3=9Fe 13/1 | 8020 Graz | Austria
> T +43(0) 50550 2957 | M +43(0) 664 8561599 | F +43(0) 50550 2950
> roman.fiedler@ait.ac.at | http://www.ait.ac.at/
>=20
> FN: 115980 i HG Wien=C2=A0 |=C2=A0 UID: ATU14703506
> http://www.ait.ac.at/Email-Disclaimer
>=20


--Sig_/X8wW8WzhkJOWmeK9gC74092
Content-Type: application/pgp-signature
Content-Description: OpenPGP digital signature

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2

iQIVAwUBVI+dtjnsnt1WYoG5AQJwvRAAhvf3emlHHWxbDEMYd5AMeyaIbXQTL/jh
2bJKD3vvCUw1GkChOb28fC1PdLg9asJjk34rplrp06ycVXS7/7zrwkZh+MCChU6V
Wn98GWJwzkpNJD+K6vQw9k6kByjSPTM3hIvVAFjtO4bWaxEol0x14mdrS4h0Lysb
t+KrWlB2kE/wEqvUJ5ivdGGQhvLmsFQaJNqIgpuQ7TvUBFJI5nv22kA+WtOnKbUR
V2l0UHJTXq1RTg/7gHpqaeGF8z/nRynGKcA5+dNrkvhj241jQVdq9QwRcKeCfMtR
JMktfSlBBaoZ+1cLz87mcEcz8Q7vWtIVuT4CyJw8bYKTmkVTxO8VtFcMDRagM4hX
tmQAS4yFBTW7/8RMsvFrOyEAsZWn4o2aAFgSKDNgWV5hIGlEazDTB8vE39ktzxEg
BNK96QBsQ65c2AEyRB0sl03uxugOe+1kWL4+/LIr6MyW175UFEQPy76KGsRX1lAI
QhYnszdd9h0gLEUi22m70g5LrPZsIEMR3CeWrH97w1fLbr5b7R9sSd8X894ZD+BV
8ZOH/g2GT9u+m2Velsp5JIYBh+8k7Q6DO4gpVERGgepdZkIoLHEjL8JixDR74ro+
iXA5afi8AIOXJJ+E2Rb40R3EjkV0ENuWORwbGkkQgSDjNDAk+J4HhvyANciK7ULV
iRLQMQBitYE=
=Zr5+
-----END PGP SIGNATURE-----

--Sig_/X8wW8WzhkJOWmeK9gC74092--