From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Hemminger Subject: Re: [patch net-next 01/15] net: introduce upper device lists Date: Sun, 30 Dec 2012 20:56:33 -0800 Message-ID: <20121230205633.5e5614ac@nehalam.linuxnetplumber.net> References: <1356868702-8144-1-git-send-email-jiri@resnulli.us> <1356868702-8144-2-git-send-email-jiri@resnulli.us> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, davem@davemloft.net, edumazet@google.com, bhutchings@solarflare.com, faisal.latif@intel.com, fbl@redhat.com, roland@kernel.org, sean.hefty@intel.com, hal.rosenstock@gmail.com, fubar@us.ibm.com, andy@greyhouse.net, divy@chelsio.com, jitendra.kalsaria@qlogic.com, sony.chacko@qlogic.com, linux-driver@qlogic.com, kaber@trash.net, ursula.braun@de.ibm.com, blaschka@linux.vnet.ibm.com, schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com, ebiederm@xmission.com, joe@perches.com, amwang@redhat.com, nhorman@tuxdriver.com, john.r.fastabend@intel.com, pablo@netfilter.org To: Jiri Pirko Return-path: Received: from mail.vyatta.com ([76.74.103.46]:40400 "EHLO mail.vyatta.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750790Ab2LaE55 (ORCPT ); Sun, 30 Dec 2012 23:57:57 -0500 In-Reply-To: <1356868702-8144-2-git-send-email-jiri@resnulli.us> Sender: netdev-owner@vger.kernel.org List-ID: On Sun, 30 Dec 2012 12:58:08 +0100 Jiri Pirko wrote: > This lists are supposed to serve for storing pointers to all upper devices. > Eventually it will replace dev->master pointer which is used for > bonding, bridge, team but it cannot be used for vlan, macvlan where > there might be multiple upper present. In case the upper link is > replacement for dev->master, it is marked with "master" flag. > > New upper device list resolves this limitation. Also, the information > stored in lists is used for preventing looping setups like > "bond->somethingelse->samebond" > > Signed-off-by: Jiri Pirko What is the use case for this? Could you describe a topology that the new upper device list supports, that the old scheme does not? I am concerned that it may open up many new possibilities for user error that were not possible before. For example how does it prevent an ethernet from being assigned to both a bonding and bridge at the same time?