From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michael Leun Subject: Re: NET_NS: unregister_netdevice: waiting for lo to become free (after using openvpn) Date: Thu, 5 Aug 2010 12:13:48 +0200 Message-ID: <20100805121348.38ac91ce@xenia.leun.net> References: <20100709235744.GA12752@kroah.com> <20100710101540.2799c9ef@xenia.leun.net> <20100710140800.GA20424@kroah.com> <20100710165208.59272ae6@xenia.leun.net> <20100710235323.5336f627@xenia.leun.net> <20100711192939.1c25dcaf@xenia.leun.net> <20100804153543.56f6ecad@xenia.leun.net> <20100804214618.GA6289@kroah.com> <20100805001105.5a3453ed@xenia.leun.net> <20100805112538.60a46cb1@xenia.leun.net> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: Greg KH , netdev@vger.kernel.org, davem@davemloft.net, linux-kernel@vger.kernel.org, Alexey Dobriyan , Patrick McHardy To: ebiederm@xmission.com (Eric W. Biederman) Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Thu, 05 Aug 2010 02:51:29 -0700 ebiederm@xmission.com (Eric W. Biederman) wrote: > Michael Leun writes: > > > Hi, > > > > On Wed, 04 Aug 2010 17:12:29 -0700 > > ebiederm@xmission.com (Eric W. Biederman) wrote: > > > > First, thank you very much for picking that up (and, of course, for > > your work at linux in general). > > > > > >> > # > unshare -n /bin/bash > >> > # > # how to setup veth device pair to get connectivity into > >> > namespace not shown here # > openvpn --config some.config > >> > [ running some traffic over vpn device not shown here ] > >> > ^c # stopping openvpn > >> > # > lsof -i > >> > # > netstat -an > >> > Active Internet connections (servers and established) > >> > Proto Recv-Q Send-Q Local Address Foreign Address > >> > State Active UNIX domain sockets (servers and established) > >> > Proto RefCnt Flags Type State I-Node Path > >> > # > ps ax|grep openvpn|grep -v grep > >> > # > # cannot find anything that suggests there is anything left > >> > from that openvpn session # > exit # logging out from shell in > >> > network namespace > >> > > >> > Now I get > >> > > >> > Jul 10 20:02:36 doris kernel: unregister_netdevice: waiting for > >> > lo to become free. Usage count = 3 [repeated] > >> > >> How many times? > > > > Unfortunately looks like indefinitely. Never watched longer so far > > (rebooted soon), but I'm seeing this message now repeated every 10 > > secs for ~10 minutes on a idle system. > > Ugh. A real bug then. These can be a pain to track down and fix. I > think the last one of these I tracked down took a couple of weeks. I > will start digging in when I get back from vacation. As I said, if I can do anything to support you, testing or so, please let me know. Until then: Have a great vacation! > > Additionally when testing this I found another one (by accident > > started my firewall script in that namespace...) - using netfilter > > RECENT makes it barf. Stripped down to the essentials it looks like > > this: > > Micheal this is on 2.6.35? Yup - almost vanilla 2.6.35, only patches for aufs (union filesystem) got in. > Alexey can you look at this BUG_ON? It looks like there has been a > regression or you missed something when you did the netns conversion > of xt_recent. > > > >> # unshare -n /bin/bash > >> # iptables -I INPUT -d 1.2.3.4 -m recent --name BLA --set > >> # exit > > > > Aug 5 11:19:47 doris kernel: [ 218.420238] ------------[ cut > > here ]------------ Aug 5 11:19:47 doris kernel: [ 218.420256] > > kernel BUG at net/netfilter/xt_recent.c:609! Aug 5 11:19:47 doris [...] -- MfG, Michael Leun