From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S268246AbUHKVg3 (ORCPT ); Wed, 11 Aug 2004 17:36:29 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S268242AbUHKVgE (ORCPT ); Wed, 11 Aug 2004 17:36:04 -0400 Received: from dial249.pm3abing3.abingdonpm.naxs.com ([216.98.75.249]:14276 "EHLO animx.eu.org") by vger.kernel.org with ESMTP id S268241AbUHKVe7 (ORCPT ); Wed, 11 Aug 2004 17:34:59 -0400 Date: Wed, 11 Aug 2004 17:33:22 -0400 From: Wakko Warner To: Alan Jenkins Cc: linux-kernel@vger.kernel.org Subject: Re: cd burning: kernel / userspace? Message-ID: <20040811213322.GA19908@animx.eu.org> References: <41189AA2.3010908@phonecoop.coop> <20040810220528.GA17537@animx.eu.org> <4119DFB0.6050204@phonecoop.coop> <20040811164109.GA18761@animx.eu.org> <411A89BB.60505@phonecoop.coop> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <411A89BB.60505@phonecoop.coop> User-Agent: Mutt/1.5.6+20040523i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Please keep me CC > A script would be cool, but dd doesn't do the memory locking and real > time priority stuff. I don't know how important this is - how old your > hardware would have to be for you to get "coasters" (buffer underun) > without it. Agreed, however, I was attempting to make a point by saying dd. > Theres an option in cdrecord to fixate an arbitrary disk (one without a > TOC for whatever reason), and one not to fixate the disk you're writing, > so it looks like fixation could and should be done on demand using an > ioctl. You'd also need ioctls to deal with multiple sessions. Already thought of this. But how to deal with it, I don't know. > I think most people would want a cdrwtool that basically pretends to be > cdrecord (in some ways ;), because thats the most intuitive way to do it > - even if you can do everything you want to with cdrwtool for the ioctls > and dd for the data. That did come to mind, as long as I don't have to use dev=x,y,z (joerg you listening? Another user steps up to say he hates it =) heheh. > I've definitely underestimated the problems with my idea, and I can't > see any tangible benefits which couldn't be obtained by hacking I can, like someone else specified. Unlike windows, linux users can put whatever filesystem (or just plain data) on a cd they choose. They wanted to specify their cdrw to send stuff directly to it and change cds. Something like this (so long as the driver supports it too): cdrwtool /dev/scd0 -ejectonclose -fixateonclose note could possibly do -dao with a fixed size. also, I don't know dump's options so I'm improvising dump -D /dev/scd0 -B 700MB /home When dump fills 700mb, it will close and await the user. Since the driver was told to fixate and eject on close, the cd comes out ready. I understand buffer underruns here and for starters, underruns aren't part of this picture, it can come later (ie after proof of concept) > cdrecord. Idealistically, its the right thing to do - but in practice > its unessecary, I'm not up to the job, and its not attractive enough for > someone to pick up. After packet writing is seamlessly merged into the > uniform cdrom driver it might start looking more important, and I might > have learnt enough to at least implement a proof of concept. I'm still > interested in hashing out more details and potential benefits. Frankly, I have found that growisofs is awkward to use. I could hack it to be better suited for what I wanted to do (I can't pipe data into it. I used to do mkisofs on one machine, send the data over the network and burn at the same time.) However, it's not as bad as dev=x,y,z For me, if this were implemented in kernel, I could do this: nail:~> mkisofs -r -no-pad /80g/debian/x/vol200 | \ ssh vegeta 'cat > /dev/scd0' (nail is a disk server, vegeta is the box with the burner on /dev/scd0, that's my current setup) -- Lab tests show that use of micro$oft causes cancer in lab animals