From mboxrd@z Thu Jan 1 00:00:00 1970 From: Philipp Hahn Subject: Re: [PATCH v4] virtio-9p: fix build on !CONFIG_UTIMENSAT Date: Thu, 18 Nov 2010 09:28:11 +0100 Message-ID: <201011180928.16981.hahn@univention.de> References: <4CE47643.7030808@jp.fujitsu.com> Mime-Version: 1.0 Content-Type: multipart/signed; boundary="nextPart2458712.ToaYXZQNu6"; protocol="application/pgp-signature"; micalg=pgp-sha1 Content-Transfer-Encoding: 7bit To: kvm@vger.kernel.org Return-path: Received: from mail.univention.de ([82.198.197.8]:2523 "EHLO mail.univention.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754894Ab0KRIhj (ORCPT ); Thu, 18 Nov 2010 03:37:39 -0500 Received: from localhost (localhost [127.0.0.1]) by slugis.knut.univention.de (Postfix) with ESMTP id 9D007164B10A for ; Thu, 18 Nov 2010 09:27:45 +0100 (CET) Received: from localhost (localhost [127.0.0.1]) by slugis.knut.univention.de (Postfix) with ESMTP id 9431B164B110 for ; Thu, 18 Nov 2010 09:27:45 +0100 (CET) Received: from mail.univention.de ([127.0.0.1]) by localhost (slugis.knut.univention.de [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 6Rn6thKOshAw for ; Thu, 18 Nov 2010 09:27:45 +0100 (CET) Received: from mammut.knut.univention.de (mammut.knut.univention.de [192.168.0.81]) by slugis.knut.univention.de (Postfix) with ESMTPSA id 43C07164B10A for ; Thu, 18 Nov 2010 09:27:45 +0100 (CET) In-Reply-To: <4CE47643.7030808@jp.fujitsu.com> Sender: kvm-owner@vger.kernel.org List-ID: --nextPart2458712.ToaYXZQNu6 Content-Type: text/plain; charset="iso-2022-jp" Content-Transfer-Encoding: quoted-printable Content-Disposition: inline Hello, Am Donnerstag 18 November 2010 01:41:39 schrieb Hidetoshi Seto: > This patch introduce a fallback mechanism for old systems that do not > support utimensat(). This fix build failure with following warnings: > +#ifdef CONFIG_UTIMENSAT > + return utimensat(dirfd, path, times, flags); > +#else > + /* Fallback: use utimes() instead of utimensat() */ Since we also had a problem with utimestat() some time ago with Samba I'd like to comment on that: Your have to be careful about compile-time-detection and runtime-detection:= If=20 you later run your utimestat()-enabled binary on an older kernel not=20 supporting that syscall, you get -1 as the return-value and errno=3DENOSYS.= So=20 even if you detected utimesatat() during compile-time, please always provid= e=20 a fallback for run-time. This is less important for people compiling there own version of kvm, but i= s=20 essential for Linux distributions, since people often run newer kvm version= s=20 on older kernels. Sincerely Philipp Hahn =2D-=20 Philipp Hahn Open Source Software Engineer hahn@univention.d= e =20 Univention GmbH Linux for Your Business fon: +49 421 22 232- 0 Mary-Somerville-Str.1 28359 Bremen fax: +49 421 22 232-99 http://www.univention.de --nextPart2458712.ToaYXZQNu6 Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (GNU/Linux) iEYEABECAAYFAkzk45sACgkQYPlgoZpUDjlS4gCgqKaHl45bElyhbp2qFFbsK20q kOQAoLmF9R0XdUY881BGbmc+m5HiYqZc =Vg9B -----END PGP SIGNATURE----- --nextPart2458712.ToaYXZQNu6--