Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754711AbaBSR75 (ORCPT ); Wed, 19 Feb 2014 12:59:57 -0500 Received: from mail-la0-f43.google.com ([209.85.215.43]:42999 "EHLO mail-la0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754021AbaBSR74 (ORCPT ); Wed, 19 Feb 2014 12:59:56 -0500 MIME-Version: 1.0 In-Reply-To: <20140219090855.610c0e04@nehalam.linuxnetplumber.net> References: <1392433180-16052-1-git-send-email-mcgrof@do-not-panic.com> <1392433180-16052-2-git-send-email-mcgrof@do-not-panic.com> <20140216105754.63738163@nehalam.linuxnetplumber.net> <1392803559.23084.99.camel@kazak.uk.xensource.com> <5304C13F.3030802@citrix.com> <20140219090855.610c0e04@nehalam.linuxnetplumber.net> From: "Luis R. Rodriguez" Date: Wed, 19 Feb 2014 09:59:33 -0800 X-Google-Sender-Auth: 2W6AZCV3DN8PrHRsHj3OiUbjK2I Message-ID: Subject: Re: [Xen-devel] [RFC v2 1/4] bridge: enable interfaces to opt out from becoming the root bridge To: Stephen Hemminger Cc: Zoltan Kiss , Ian Campbell , kvm@vger.kernel.org, "netdev@vger.kernel.org" , bridge@lists.linux-foundation.org, "linux-kernel@vger.kernel.org" , xen-devel@lists.xenproject.org Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Feb 19, 2014 at 9:08 AM, Stephen Hemminger wrote: > On Wed, 19 Feb 2014 09:02:06 -0800 > "Luis R. Rodriguez" wrote: > >> Folks, what if I repurpose my patch to use the IFF_BRIDGE_NON_ROOT (or >> relabel to IFF_ROOT_BLOCK_DEF) flag for a default driver preference >> upon initialization so that root block will be used once the device >> gets added to a bridge. The purpose would be to avoid drivers from >> using the high MAC address hack, streamline to use a random MAC >> address thereby avoiding the possible duplicate address situation for >> IPv6. In the STP use case for these interfaces we'd just require >> userspace to unset the root block. I'd consider the STP use case the >> most odd of all. The caveat to this approach is 3.8 would be needed >> (or its the root block patches cherry picked) for base kernels older >> than 3.8. >> >> Stephen? >> >> Luis > > Don't add IFF_ flags that adds yet another API hook into bridge. The goal was not to add a userspace API, but rather consider a driver initialization preference. > Please only use the netlink/sysfs flags fields that already exist > for new features. Sure, but what if we know a driver in most cases wants the root block and we'd want to make it the default, thereby only requiring userspace for toggling it off. Luis -- 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/