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From: Michael Leun on 11 Jul 2010 13:40 Hi, On Sat, 10 Jul 2010 16:52:08 +0200 Michael Leun <lkml20100708(a)newton.leun.net> wrote: > # tunctl -u ml -t tap1 > works as expected, but > # unshare -n /bin/bash > # tunctl -u ml -t tap1 [bug (no sysfs support for net namespaces at all) solved in 2.6.35-rcX - I used 2.6.34.1] Now that we have solved that last one I've another glitch (this time using 2.6.35-rc4): In an network namespace I can use an tun/tap tunnel through ssh and when closing that namespace then eveything is fine. But when using openvpn (also tunnel trough tun/tap) in an network namespace and then closing that namespace I get: unregister_netdevice: waiting for lo to become free [repeated] Please see the following two examples showing that difference: # > unshare -n /bin/bash # > # how to setup veth device pair to get connectivity into namespace not shown here # > tunctl -u ml -t tap1 # > ssh -o Tunnel=Ethernet -w 1:1 somewhere [ running some traffic over tap1 not shown here ] ^d # logging out from somewhere # > tunctl -d tap1 # > exit # logging out from shell in network namespace Now the veth device pair used automagically vanishes and nothing from that different network namespace remains - very well. but # > 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] Now one might say it is fault of openvpn (used OpenVPN 2.1_rc20 i586-suse-linux - the one in openSuSE 11.2 package), openvpn didn't close some ressource and ssh does fine. But: should'nt kernel clean up after process when it exits? And/or: Should'nt kernel clean up if last process in network namespace exits - there is nothing left which might use that interface?! Greg KH <greg(a)kroah.com> wrote: > Yes, you are correct. Care to resend all of this to the > network-namespace developer(s) and the netdev mailing list so that the > correct people are notified so they can fix it all? [X] done - hopefully, cannot find a particular network namespace developer in MAINTAINERS or source files. If such a one exists, please forward. Thanks. -- MfG, Michael Leun -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |