From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eyal Birger Subject: Re: xfrm, ip tunnel: non released device reference upon device unregistration Date: Tue, 6 Feb 2018 21:19:46 +0200 Message-ID: <20180206211946.217783da@jimi> References: <20180204132118.6fef9bf0@jimi> <20180206125624.GE15427@breakpoint.cc> <20180206130937.blxbrhmkpe3kt6lh@gauss3.secunet.de> <20180206131509.GA14261@breakpoint.cc> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: Steffen Klassert , netdev@vger.kernel.org, herbert@gondor.apana.org.au, davem@davemloft.net, shmulik@metanetworks.com To: Florian Westphal Return-path: Received: from mail-wr0-f170.google.com ([209.85.128.170]:46847 "EHLO mail-wr0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750899AbeBFTT4 (ORCPT ); Tue, 6 Feb 2018 14:19:56 -0500 Received: by mail-wr0-f170.google.com with SMTP id 35so3132507wrb.13 for ; Tue, 06 Feb 2018 11:19:56 -0800 (PST) In-Reply-To: <20180206131509.GA14261@breakpoint.cc> Sender: netdev-owner@vger.kernel.org List-ID: On Tue, 6 Feb 2018 14:15:09 +0100 Florian Westphal wrote: > Steffen Klassert wrote: > > I gave the patch a quick try, but still I get this: > > > > unregister_netdevice: waiting for dummy1 to become free. Usage > > count = 2 > > Was that with Eyals setup or the bridge one I posted? > > If it was Eyals setup, its possible the patch missed hookup > to whatever tunnel infra is used (the setup I used has ipip tunnel, > everything is ipv4). > Thanks! Indeed the setup I'm testing uses ip6_tunnel. I have tested a fix in the spirit of the patch and it looks valid for ip6_tunnel as well. It looks though that this change would need to be added to any tunnel device using dst_cache (vxlan, geneve, gre, ...). > Also, perhaps it would be best to not bother with checking the > device in question at all and unconditionally put device reference > of all the dst_caches. With setups that have e.g. 1k devices going > down per second (ppp dialin and the like) doing the full search for > every notify event would be rather expensive. > I'm wondering - non-xfrm dsts are already correctly invalidated, so do you think it makes sense to invalidate caches for devices that have no xfrm dsts? or maybe I didn't understand the suggestion? Eyal.