Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966424AbWKNWwK (ORCPT ); Tue, 14 Nov 2006 17:52:10 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S966429AbWKNWwK (ORCPT ); Tue, 14 Nov 2006 17:52:10 -0500 Received: from py-out-1112.google.com ([64.233.166.176]:25633 "EHLO py-out-1112.google.com") by vger.kernel.org with ESMTP id S966418AbWKNWwG (ORCPT ); Tue, 14 Nov 2006 17:52:06 -0500 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:sender:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references:x-google-sender-auth; b=UsOqSbeASR6JvflJ+qUB+ywqJm0fQk3sicoSt5Q8s2X4ojkHN4p4pKFoABlstOKGX8WqRySVzEfEPj5XIE/MLSGWOG4EfM0rb+QphMGtzfDA/e3HH5vBgVIOnQePQ96R42Q1Gr0eLBKSpvvONUVrP4gqTeJJmQsOsX4Lrek0jSw= Message-ID: <806dafc20611141452y7262df80g6fb7d3c0581f7b7f@mail.gmail.com> Date: Tue, 14 Nov 2006 17:52:04 -0500 From: "Monty Montgomery" To: ltuikov@yahoo.com Subject: Re: 2.6.19-rc3 system freezes when ripping with cdparanoia at ioctl(SG_IO) Cc: "Christoph Hellwig" , dougg@torque.net, "Tejun Heo" , "Brice Goglin" , "Jens Axboe" , "Gregor Jasny" , "Linux Kernel" , "Jeff Garzik" , linux-ide@vger.kernel.org, linux-scsi@vger.kernel.org In-Reply-To: <589461.23187.qm@web31813.mail.mud.yahoo.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <20061111104642.GA3356@infradead.org> <589461.23187.qm@web31813.mail.mud.yahoo.com> X-Google-Sender-Auth: 3449ceb7044e89e6 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1888 Lines: 41 On 11/11/06, Luben Tuikov wrote: > --- Christoph Hellwig wrote: > > On Fri, Nov 10, 2006 at 12:08:15PM -0800, Luben Tuikov wrote: > > > P.S. I'd love to see SG_DXFER_TO_FROM_DEV completely ripped out > > > of sg.c, for obvious reasons. Can you not duplicate the resid "fix" > > > it provides into "FROM_DEV" -- do apps really rely on it? > > > > At the beginning of this thread it was mentioned cdparanio uses it. > > But in general we can't just rip out userland interfaces, we pretend > > to have a stable userspace abi (and except for the big sysfs mess that > > actually comes very close to the truth). > > The more reason to think things thorougly when introducing > new code and architecture into a kernel. It was introduced for a good reason, and that reason is still relevant today. Cdparanoia is not using it gratuitously. The only problem is that the implementation had a bug (well, at least two bugs) and only sg ever implemented it correctly. Had block and sata implemente dit correctly, we'd not be having this discussion. Or you can blame a lower level layer for having no way to inform mid-level drivers that DMA only completed a partial transfer. "but anyway"... This lockup was happening using SATA through the block layer, or does SATA implement its own version of the ioctl? Back when I was testing my probing code, the buggy kernel would reject the request, not lock up-- did a change make it inot 2.6.18 or later that causes a lockup instead? (I never tested with SATA cdroms, as I don't have any. I tested with IDE and SCSI and saw correct or detectable behavior) Monty - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/