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 (adding ipv6 address to interface) Date: Mon, 6 Dec 2010 23:47:25 +0100 Message-ID: <20101206234725.622a2212@xenia.leun.net> References: <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> <20100805134707.0442a7b1@xenia.leun.net> <20101021171532.54af5e97@xenia.leun.net> <20101022124858.GA719746@jupiter.n2.diac24.net> <20101022190532.00e9e5d8@xenia.leun.net> <20101024151541.161bf46c@xenia.leun.net> <4CFD0A8F.8010906@univ-nantes.fr> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: jean-philippe.menil@univ-nantes.fr, netdev@vger.kernel.org, David Lamparter , Greg KH , 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 Mon, 06 Dec 2010 13:22:00 -0800 ebiederm@xmission.com (Eric W. Biederman) wrote: > Menil Jean-Philippe writes: >=20 > > Le 24/10/2010 15:15, Michael Leun a =E9crit : > >> On Fri, 22 Oct 2010 19:05:32 +0200 > >> Michael Leun wrote: > >> > >>> On Fri, 22 Oct 2010 14:48:58 +0200 > >>> David Lamparter wrote: > >>> > >>>> On Thu, Oct 21, 2010 at 05:15:32PM +0200, Michael Leun wrote: > >>>>> unfortunately the bug described below originally reported in > >>>>> 2.6.35-rcX is still there in 2.6.36. [...] > > curiously, i'm facing a similar problem in 2.6.36.1 > > > > in my container, when i configure ipv6 adress on the interfaces, > > everything seems good on the first boot of the host. If i shutdown > > my container (lxc), then boot it, i observe the following logs: > > Dec 6 17:04:12 suntory.u06.univ-nantes.prive kernel: [ 368.192019= ] > > unregister_netdevice: waiting for lo to become free. Usage count =3D= 4 > > Dec 6 17:04:22 suntory.u06.univ-nantes.prive kernel: [ 378.432018= ] > > unregister_netdevice: waiting for lo to become free. Usage count =3D= 4 > > Dec 6 17:04:32 suntory.u06.univ-nantes.prive kernel: [ 388.672015= ] > > unregister_netdevice: waiting for lo to become free. Usage count =3D= 4 > > Dec 6 17:04:42 suntory.u06.univ-nantes.prive kernel: [ 398.912016= ] > > unregister_netdevice: waiting for lo to become free. Usage count =3D= 4 > > Dec 6 17:04:53 suntory.u06.univ-nantes.prive kernel: [ 409.152016= ] > > unregister_netdevice: waiting for lo to become free. Usage count =3D= 4 > > Dec 6 17:05:03 suntory.u06.univ-nantes.prive kernel: [ 419.392018= ] > > unregister_netdevice: waiting for lo to become free. Usage count =3D= 4 > > Dec 6 17:05:13 suntory.u06.univ-nantes.prive kernel: [ 429.632018= ] > > unregister_netdevice: waiting for lo to become free. Usage count =3D= 4 > > Dec 6 17:05:23 suntory.u06.univ-nantes.prive kernel: [ 439.876016= ] > > unregister_netdevice: waiting for lo to become free. Usage count =3D= 4 > > Dec 6 17:05:34 suntory.u06.univ-nantes.prive kernel: [ 450.116015= ] > > unregister_netdevice: waiting for lo to become free. Usage count =3D= 4 > > Dec 6 17:05:44 suntory.u06.univ-nantes.prive kernel: [ 460.356019= ] > > unregister_netdevice: waiting for lo to become free. Usage count =3D= 4 > > Dec 6 17:05:54 suntory.u06.univ-nantes.prive kernel: [ 470.596020= ] > > unregister_netdevice: waiting for lo to become free. Usage count =3D= 4 > > Dec 6 17:06:04 suntory.u06.univ-nantes.prive kernel: [ 480.836019= ] > > unregister_netdevice: waiting for lo to become free. Usage count =3D= 4 > > Dec 6 17:06:05 suntory.u06.univ-nantes.prive kernel: > > [ 481.468021] INFO: task lxc-start:3805 blocked for more than 120 > > seconds. > > > > Then i must reboot the host. > > The same on kernel 2.6.34, but everything is good on a 2.6.32 > > > > Some relvant informations about the kernel: > > root@suntory:~# cat /boot/config-2.6.36.1-dsiun-1d | grep -i sysfs > > # CONFIG_SYSFS_DEPRECATED_V2 is not set > > CONFIG_ACPI_SYSFS_POWER=3Dy > > # CONFIG_WIRELESS_EXT_SYSFS is not set > > CONFIG_ISCSI_BOOT_SYSFS=3Dm > > CONFIG_RTC_INTF_SYSFS=3Dy > > CONFIG_SYSFS=3Dy > > root@suntory:~# cat /boot/config-2.6.36.1-dsiun-1d | grep -i net_ns > > CONFIG_NET_NS=3Dy > > > > Is there anything in my configuration, i must check in order to get > > ipv6 working fully in the container? >=20 > 2.6.37-rc4 is working here. There were problems earlier in the > earlier rcs. Can you try that? >=20 > There have been a couple of different reference counting bugs between > 2.6.34 and the present, and I haven't tracked them, just noticed they > exist. Can reproduce the following still on 2.6.36.1, but NOT on 2.6.37-rc4 - so indeed seems to be fixed! Putting an ipv6 address on a device seems to be the trigger: OrigNS > # ip link add type veth OrigNS > # ip link set dev veth0 up OrigNS > # unshare -n /bin/bash NewNS > # echo $$ OrigNS > # ip link set dev veth1 netns # this, of course is on a different terminal NewNS > # ip link set dev veth1 up NewNS > # ip -6 addr add dev veth1 fd50:dead:beef::1/64 NewNS > # exit Yields kernel: unregister_netdevice: waiting for veth1 to become free. Usage count =3D 3 --=20 MfG, Michael Leun