From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754661Ab2KESSQ (ORCPT ); Mon, 5 Nov 2012 13:18:16 -0500 Received: from mail-pa0-f46.google.com ([209.85.220.46]:42194 "EHLO mail-pa0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754593Ab2KESSO (ORCPT ); Mon, 5 Nov 2012 13:18:14 -0500 Date: Mon, 5 Nov 2012 10:18:09 -0800 From: Tejun Heo To: Alan Cox Cc: Paolo Bonzini , Ric Wheeler , Petr Matousek , Kay Sievers , Jens Axboe , linux-kernel@vger.kernel.org, "James E.J. Bottomley" Subject: Re: setting up CDB filters in udev (was Re: [PATCH v2 0/3] block: add queue-private command filter, editable via sysfs) Message-ID: <20121105181809.GE19354@mtj.dyndns.org> References: <20121025180045.GL11442@htj.dyndns.org> <1657557410.1945557.1351190120407.JavaMail.root@redhat.com> <20121031212241.GZ2945@htj.dyndns.org> <5093DD5E.6030808@redhat.com> <20121102165123.GB3823@mtj.dyndns.org> <509407B7.3030904@redhat.com> <20121102175350.GB27843@mtj.dyndns.org> <50951A0E.9010103@redhat.com> <20121103145052.0da49071@pyramind.ukuu.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20121103145052.0da49071@pyramind.ukuu.org.uk> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, Alan. On Sat, Nov 03, 2012 at 02:50:52PM +0000, Alan Cox wrote: > > I proposed a way to implement the ultimately flexible solution (BPF) and > > you shot it down because it was too complex. Alan is showing you with > > multiple examples of why the flexibility would be useful (perhaps nobody > > would use it, but the use cases _are_ there), and you are mostly > > ignoring them. > > My feeling too - It feels to me like Tejun is trying to railroad a broken > non-solution into the system without regards for anyone else and by > simply dismissing any other input. The only other use case brought up is allowing use of vendor-specific commands while burning CDs. Given that the usual burning has been working well enough for years now, I don't really think that's a strong enough reason to add full BPF filtering to SG_IO. It's just highly unusual thing to do and there isn't strong enough use case for it. To me, it feels like you guys are pushing a feature without strong enough use case. So, I'm still pretty strongly against it. Thanks. -- tejun