From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933479AbWKSWae (ORCPT ); Sun, 19 Nov 2006 17:30:34 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S933493AbWKSWae (ORCPT ); Sun, 19 Nov 2006 17:30:34 -0500 Received: from cantor2.suse.de ([195.135.220.15]:54985 "EHLO mx2.suse.de") by vger.kernel.org with ESMTP id S933479AbWKSWad (ORCPT ); Sun, 19 Nov 2006 17:30:33 -0500 Message-ID: <4560DB6B.9020601@suse.com> Date: Sun, 19 Nov 2006 17:32:11 -0500 From: Jeff Mahoney Organization: SUSE Labs, Novell, Inc User-Agent: Thunderbird 1.5 (X11/20060317) MIME-Version: 1.0 To: Al Viro Cc: Randy Dunlap , Andi Kleen , lkml , reiserfs-dev@namesys.com, sam@ravnborg.org Subject: Re: reiserfs NET=n build error References: <20061118202206.01bdc0e0.randy.dunlap@oracle.com> <200611190650.49282.ak@suse.de> <45608FC2.5040406@suse.com> <200611191959.55969.ak@suse.de> <4560AAC1.3000800@oracle.com> <20061119205711.GE3078@ftp.linux.org.uk> In-Reply-To: <20061119205711.GE3078@ftp.linux.org.uk> X-Enigmail-Version: 0.94.0.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Al Viro wrote: > On Sun, Nov 19, 2006 at 11:04:33AM -0800, Randy Dunlap wrote: >> Andi Kleen wrote: >>>>> I would copy a relatively simple C implementation, like >>>>> arch/h8300/lib/checksum.c >>>> As long as the h8300 version has the same output as the x86 version. >>> The trouble is that the different architecture have different output >>> for csum_partial. So you already got a bug when someone wants to move >>> file systems. >>> >>> -Andi >> That argues for having only one version of it (in a lib.; my preference) >> -or- Every module having its own local copy/version of it. :( > > Wrong. csum_partial() result is defined modulo 0xffff and it's basically > "whatever's convenient as intermediate for this architecture". > > reiserfs use of it is just plain broken. net/* is fine, since all > final uses are via csum_fold() or equivalents. > > Note that reiserfs use is broken in another way: it takes fixed-endian value > and feeds it to cpu_to_le32(). IOW, even if everything had literally the > same csum_partial(), the value it shits on disk would be endian-dependent. Oh great. Even better. :( - -Jeff - -- Jeff Mahoney SUSE Labs -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.2 (GNU/Linux) Comment: Using GnuPG with SUSE - http://enigmail.mozdev.org iD8DBQFFYNtqLPWxlyuTD7IRAux8AKCbxW4zX5Q7y8LfPT0FY/W4A8v0PQCggV11 EbMvTGkAb5WXa0f7EgUz5Qk= =Zm0q -----END PGP SIGNATURE-----