From mboxrd@z Thu Jan 1 00:00:00 1970 From: Patrick McHardy Subject: Re: request_module while holding rtnl semaphore Date: Wed, 10 Nov 2004 02:29:47 +0100 Message-ID: <41916F0B.5010809@trash.net> References: <41899DCF.3050804@trash.net> <20041109161126.376f755c.davem@davemloft.net> <20041110010113.GJ31969@postel.suug.ch> <41916A91.3080107@trash.net> <20041110012251.GK31969@postel.suug.ch> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Cc: "David S. Miller" , Herbert Xu , netdev@oss.sgi.com Return-path: To: Thomas Graf In-Reply-To: <20041110012251.GK31969@postel.suug.ch> Sender: netdev-bounce@oss.sgi.com Errors-to: netdev-bounce@oss.sgi.com List-Id: netdev.vger.kernel.org Thomas Graf wrote: >* Patrick McHardy <41916A91.3080107@trash.net> 2004-11-10 02:10 > > >>Can you please show an example of a case where this is needed ? >>Just to help me understand. >> >> > >The action code might load modules in the middle of a classifier >configuration and it will be very hard to reverse those changes. >Right now we could move it to the top of all configurations and it >would probably be possible to get back where we fetch the device >but it will get impossible once a classifier requires module >loading which is not unlikely. > > Assuming all error-paths do proper cleanup, returning -EAGAIN should always result in the same configuration state as before. Module-loading as a side-effect is exactly why this is done, the replay will have all modules available. >Well, it's not impossible but it would mean to have the action >code parse the TLV and just try to load the module, then report >to the classifier so it can try to load its own modules and then do >the actual action and classifier configuration. I don't even want to >think of how nasty it gets once a action module requests modules itself ;-> > > I still don't understand the problem. Regards Patrick