Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964887AbWBMWsG (ORCPT ); Mon, 13 Feb 2006 17:48:06 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964888AbWBMWsF (ORCPT ); Mon, 13 Feb 2006 17:48:05 -0500 Received: from smtp.enter.net ([216.193.128.24]:46856 "EHLO smtp.enter.net") by vger.kernel.org with ESMTP id S964887AbWBMWsE (ORCPT ); Mon, 13 Feb 2006 17:48:04 -0500 From: "D. Hazelton" To: Joerg Schilling Subject: Re: CD writing in future Linux (stirring up a hornets' nest) Date: Mon, 13 Feb 2006 17:57:10 -0500 User-Agent: KMail/1.8.1 Cc: jerome.lacoste@gmail.com, peter.read@gmail.com, mj@ucw.cz, matthias.andree@gmx.de, linux-kernel@vger.kernel.org, jim@why.dont.jablowme.net, jengelh@linux01.gwdg.de References: <20060208162828.GA17534@voodoo> <5a2cf1f60602100738r465dd996m2ddc8ef18bf1b716@mail.gmail.com> <43F06220.nailKUS5D8SL2@burner> In-Reply-To: <43F06220.nailKUS5D8SL2@burner> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200602131757.11725.dhazelton@enter.net> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2887 Lines: 56 On Monday 13 February 2006 05:40, Joerg Schilling wrote: > jerome lacoste wrote: > > On 2/10/06, Joerg Schilling wrote: > > > "D. Hazelton" wrote: > > > > And does cdrecord even need libscg anymore? From having actually gone > > > > through your code, Joerg, I can tell you that it does serve a larger > > > > purpose. But at this point I have to ask - besides cdrecord and a few > > > > other _COMPACT_ _DISC_ writing programs, does _ANYONE_ use libscg? Is > > > > it ever used to access any other devices that are either SCSI or use > > > > a SCSI command protocol (like ATAPI)? My point there is that you > > > > have a wonderful library, but despite your wishes, there is no proof > > > > that it is ever used for anything except writing/ripping CD's. > > > > > > Name a single program (not using libscg) that implements user space > > > SCSI and runs on as many platforms as cdrecord/libscg does. > > > > I have 2 technical questions, and I hope that you will take the time > > to answer them. > > > > 1) extract from the README of the latest stable cdrtools package: > > > > Linux driver design oddities > > ****************************************** Although cdrecord supports to > > use dev=/dev/sgc, it is not recommended and it is unsupported. > > > > The /dev/sg* device mapping in Linux is not stable! Using > > dev=/dev/sgc in a shell script may fail after a reboot because the device > > you want to talk to has moved to /dev/sgd. For the proper and OS > > independent dev=,, syntax read the man page of cdrecord. > > > > My understanding of that is you say to not use dev=/dev/sgc because it > > isn't stable. Now that you've said that bus,tgt,lun is not stable on > > Linux (because of a "Linux bug") why is the b,t,l scheme preferred > > over the /dev/sg* one ? > > b,t,l _is_ stable as long as the OS does a reasonable and orthogonal work. > > This was true until ~ 2001, when Linux introduced unstable USB handling. > Note that this fact is not a failure from libscg but from Linux. Isn't that also when the USB system underwent a massive rewrite to fully support hotplugging and to fix a lot of bugs that were present in the original implementation? Still, the question I posed in my earlier post remains - why can't you have your program do the BTL mappings behind the scenes? You can easily allow it from the command line and also allow pointing to a /dev entry... If you want I'll actually put together a patch based on whatever version of cdrecord I have here on my system and send it to you. DRH - 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/