Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755396Ab1BOQ4c (ORCPT ); Tue, 15 Feb 2011 11:56:32 -0500 Received: from mx1.redhat.com ([209.132.183.28]:30744 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751209Ab1BOQ4b (ORCPT ); Tue, 15 Feb 2011 11:56:31 -0500 Date: Tue, 15 Feb 2011 16:56:18 +0000 From: Alasdair G Kergon To: Tejun Heo Cc: Milan Broz , Alasdair G Kergon , device-mapper development , Jens Axboe , Tao Ma , linux-kernel@vger.kernel.org Subject: Re: [dm-devel] [PATCH][RFC] dm: Do not open log and cow device read-write for read-only mappings Message-ID: <20110215165618.GA28164@agk-dp.fab.redhat.com> Mail-Followup-To: Tejun Heo , Milan Broz , Alasdair G Kergon , device-mapper development , Jens Axboe , Tao Ma , linux-kernel@vger.kernel.org References: <4D5A6EF4.3030905@redhat.com> <20110215124629.GF5825@agk-dp.fab.redhat.com> <20110215152033.GK3160@htj.dyndns.org> <20110215154625.GG5825@agk-dp.fab.redhat.com> <20110215155018.GM3160@htj.dyndns.org> <4D5AA45C.7050600@redhat.com> <20110215161228.GN3160@htj.dyndns.org> <4D5AAB8F.50901@redhat.com> <20110215164128.GQ3160@htj.dyndns.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110215164128.GQ3160@htj.dyndns.org> Organization: Red Hat UK Ltd. Registered in England and Wales, number 03798903. Registered Office: Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SL4 1TE. User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 867 Lines: 19 On Tue, Feb 15, 2011 at 05:41:28PM +0100, Tejun Heo wrote: > That said, maybe -EROFS is the better fit. I really have no idea. > Maybe we should just revert and leave rw accesses to ro block devices > alone. I'd agree that the change to enforce readonly devs is a desirable change to make. But we're still discovering exactly what things it breaks and as well as further kernel patches some userspace changes seem unavoidable. Personally I'd prefer it if this change went back into linux-next to give us more time to prepare for it cleanly. It's unfortunate none of us picked up on these problems sooner. Alasdair -- 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/