From mboxrd@z Thu Jan 1 00:00:00 1970 From: "tgraf@suug.ch" Subject: Re: [PATCH net-next] bridge: fix setlink/dellink notifications Date: Thu, 15 Jan 2015 00:01:25 +0000 Message-ID: <20150115000125.GG2105@casper.infradead.org> References: <1421218123-18346-1-git-send-email-roopa@cumulusnetworks.com> <54B6FD60.8020106@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: "Arad, Ronen" , "roopa@cumulusnetworks.com" , "netdev@vger.kernel.org" , "shemminger@vyatta.com" , "vyasevic@redhat.com" , "jhs@mojatatu.com" , "sfeldma@gmail.com" , "jiri@resnulli.us" , "wkok@cumulusnetworks.com" To: John Fastabend Return-path: Received: from casper.infradead.org ([85.118.1.10]:34324 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752306AbbAOABd (ORCPT ); Wed, 14 Jan 2015 19:01:33 -0500 Content-Disposition: inline In-Reply-To: <54B6FD60.8020106@gmail.com> Sender: netdev-owner@vger.kernel.org List-ID: On 01/14/15 at 03:36pm, John Fastabend wrote: > On 01/14/2015 03:22 PM, Arad, Ronen wrote: > >What is the purpose of the above two lines (not changed by the patch)? > >They seem to copy over the flags with the successfully applied cases > >(MASTER and/or SELF) flags cleared back into the incoming netlink message. > >I could not figure any place where the modified flags attribute is used > > This allows userspace to learn which operation failed when it is an > operation to set both the software bridge via BRIDGE_FLAGS_MASTER and > the the hardware via BRIDGE_FLAGS_SELF. When we get the error back > software looks at the flags to figure out how to recover/retry/etc. The intent of including the original message in the error Netlink message was originally to track the request that lead to the error ;-)