From owner-freebsd-current@FreeBSD.ORG Sun Nov 30 12:00:27 2008 Return-Path: Delivered-To: current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id E82F31065691 for ; Sun, 30 Nov 2008 12:00:27 +0000 (UTC) (envelope-from kostikbel@gmail.com) Received: from mail.terabit.net.ua (mail.terabit.net.ua [195.137.202.147]) by mx1.freebsd.org (Postfix) with ESMTP id 87AC68FC23 for ; Sun, 30 Nov 2008 12:00:27 +0000 (UTC) (envelope-from kostikbel@gmail.com) Received: from skuns.zoral.com.ua ([91.193.166.194] helo=mail.zoral.com.ua) by mail.terabit.net.ua with esmtps (TLSv1:AES256-SHA:256) (Exim 4.63 (FreeBSD)) (envelope-from ) id 1L6kyQ-0000xz-2b; Sun, 30 Nov 2008 14:00:26 +0200 Received: from deviant.kiev.zoral.com.ua (root@deviant.kiev.zoral.com.ua [10.1.1.148]) by mail.zoral.com.ua (8.14.2/8.14.2) with ESMTP id mAUC0M9b009300 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Sun, 30 Nov 2008 14:00:23 +0200 (EET) (envelope-from kostikbel@gmail.com) Received: from deviant.kiev.zoral.com.ua (kostik@localhost [127.0.0.1]) by deviant.kiev.zoral.com.ua (8.14.3/8.14.3) with ESMTP id mAUC0MO1032501; Sun, 30 Nov 2008 14:00:22 +0200 (EET) (envelope-from kostikbel@gmail.com) Received: (from kostik@localhost) by deviant.kiev.zoral.com.ua (8.14.3/8.14.3/Submit) id mAUC0MPS032500; Sun, 30 Nov 2008 14:00:22 +0200 (EET) (envelope-from kostikbel@gmail.com) X-Authentication-Warning: deviant.kiev.zoral.com.ua: kostik set sender to kostikbel@gmail.com using -f Date: Sun, 30 Nov 2008 14:00:22 +0200 From: Kostik Belousov To: Luigi Rizzo Message-ID: <20081130120022.GH3045@deviant.kiev.zoral.com.ua> References: <20081130043110.GA48062@onelab2.iet.unipi.it> <20081130105859.GF3045@deviant.kiev.zoral.com.ua> <20081130115639.GA60027@onelab2.iet.unipi.it> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="nOM8ykUjac0mNN89" Content-Disposition: inline In-Reply-To: <20081130115639.GA60027@onelab2.iet.unipi.it> User-Agent: Mutt/1.4.2.3i X-Virus-Scanned: ClamAV version 0.93.3, clamav-milter version 0.93.3 on skuns.kiev.zoral.com.ua X-Virus-Status: Clean X-Spam-Status: No, score=-4.4 required=5.0 tests=ALL_TRUSTED,AWL,BAYES_00 autolearn=ham version=3.2.5 X-Spam-Checker-Version: SpamAssassin 3.2.5 (2008-06-10) on skuns.kiev.zoral.com.ua X-Virus-Scanned: mail.terabit.net.ua 1L6kyQ-0000xz-2b 5f876b9814e246cf55695d9a65c32f47 X-Terabit: YES Cc: current@freebsd.org Subject: Re: libufs limitation trying to make newfs work on plain files X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 30 Nov 2008 12:00:28 -0000 --nOM8ykUjac0mNN89 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Sun, Nov 30, 2008 at 12:56:39PM +0100, Luigi Rizzo wrote: > On Sun, Nov 30, 2008 at 12:58:59PM +0200, Kostik Belousov wrote: > > On Sun, Nov 30, 2008 at 05:31:10AM +0100, Luigi Rizzo wrote: > > > libufs limitation trying to make newfs work on plain files > ... > > You proposal would introduce incompatibility in the ABI exposed by > > one of the system library. The solution adopted by Linux and (recently) > > by FreeBSD, is to use ELF symbol versioning. It seems that this case > > can be handled by symver. As additional benefit, after your work > > we would got one more symver-ed system library. >=20 > could you point me to an example in freebsd that shows how to > use this feature ? In the FreeBSD src tree, at least libc, libm, libthr and kerberos libraries utilize symver. There is a http://people.freebsd.org/~deischen/symver/freebsd_versioning.txt text that describes intended use os symver in the FreeBSD. You can look at the r175688 for real-world handling of the ABI change (in particular, in the structure definition) using symver. --nOM8ykUjac0mNN89 Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (FreeBSD) iEYEARECAAYFAkkygFUACgkQC3+MBN1Mb4iN0wCgwupzV/+V7z8fKFhWhbQMKQdR rNUAoJ94PwiKJtGSzTHJ27Omef+H5Zct =CO29 -----END PGP SIGNATURE----- --nOM8ykUjac0mNN89--