From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754832Ab2KEUM7 (ORCPT ); Mon, 5 Nov 2012 15:12:59 -0500 Received: from lxorguk.ukuu.org.uk ([81.2.110.251]:40069 "EHLO lxorguk.ukuu.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754600Ab2KEUM6 (ORCPT ); Mon, 5 Nov 2012 15:12:58 -0500 Date: Mon, 5 Nov 2012 20:17:54 +0000 From: Alan Cox To: Tejun Heo 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: <20121105201754.7d82deff@pyramind.ukuu.org.uk> In-Reply-To: <20121105200955.GA26735@htj.dyndns.org> References: <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> <20121105181809.GE19354@mtj.dyndns.org> <20121105201208.2ea500cc@pyramind.ukuu.org.uk> <20121105200955.GA26735@htj.dyndns.org> X-Mailer: Claws Mail 3.8.1 (GTK+ 2.24.8; x86_64-redhat-linux-gnu) Face: iVBORw0KGgoAAAANSUhEUgAAADAAAAAwBAMAAAClLOS0AAAAFVBMVEWysKsSBQMIAwIZCwj///8wIhxoRDXH9QHCAAABeUlEQVQ4jaXTvW7DIBAAYCQTzz2hdq+rdg494ZmBeE5KYHZjm/d/hJ6NfzBJpp5kRb5PHJwvMPMk2L9As5Y9AmYRBL+HAyJKeOU5aHRhsAAvORQ+UEgAvgddj/lwAXndw2laEDqA4x6KEBhjYRCg9tBFCOuJFxg2OKegbWjbsRTk8PPhKPD7HcRxB7cqhgBRp9Dcqs+B8v4CQvFdqeot3Kov6hBUn0AJitrzY+sgUuiA8i0r7+B3AfqKcN6t8M6HtqQ+AOoELCikgQSbgabKaJW3kn5lBs47JSGDhhLKDUh1UMipwwinMYPTBuIBjEclSaGZUk9hDlTb5sUTYN2SFFQuPe4Gox1X0FZOufjgBiV1Vls7b+GvK3SU4wfmcGo9rPPQzgIabfj4TYQo15k3bTHX9RIw/kniir5YbtJF4jkFG+dsDK1IgE413zAthU/vR2HVMmFUPIHTvF6jWCpFaGw/A3qWgnbxpSm9MSmY5b3pM1gvNc/gQfwBsGwF0VCtxZgAAAAASUVORK5CYII= Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 5 Nov 2012 12:09:55 -0800 Tejun Heo wrote: > Hey, Alan. > > On Mon, Nov 05, 2012 at 08:12:08PM +0000, Alan Cox wrote: > > There are two sensible choices here IMHO > > > > - The simple sysctl > > > > - Doing the job right > > > > A half way solution such as that you are proposing seems to me to achieve > > nothing other than guaranteeing we'll have another pile of useless crap > > to maintain forever as ABI. > > I'm all for simple. Just throw in a sysfs binary switch to allow all > SG_IO for a given block device for users w/ write access. I'd be > completely happy with that. IMHO that's the best option for now - if it fixes the specific case of concern right now. It's a trivial interface, it's trivial security (need to check CAP_SYS_RAWIO to flip) and it means that the job can be done properly when there is consensus without a whole extra legacy API stuck behind. Alan