Hi,
I've just updated my kernel 4.4.x and noticed a regression. Bisecting pointed me to the commit 2417da3f4d6bc ("ipv6: only call ip6_route_dev_notify() once for NETDEV_UNREGISTER") [0] which is backport of upstream 76da0704507bb. That backported commit has appeared in a 4.4.103.
I use OpenWrt/LEDE [1] distribution and LXC [2] 1.1.5. After stopping a container I start getting these messages: [ 229.419188] unregister_netdevice: waiting for lo to become free. Usage count = 1 [ 239.660408] unregister_netdevice: waiting for lo to become free. Usage count = 1 [ 249.839189] unregister_netdevice: waiting for lo to become free. Usage count = 1 (...)
Trying to start LXC nevertheless results in lxc-start command hang around network configuration. Trying to query LXC state afterwards results in a lxc-info command hang too.
I tried Googling for this issue and found similar reports: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1729637 https://github.com/fnproject/fn/issues/686 https://lime-technology.com/forums/topic/66863-kernelunregister_netdevice-wa... all of them related to the Docker, which is probably a similar use case to the LXC.
I couldn't find any reference to commit 76da0704507bb that could suggest fixing the problem I'm seeing.
Does anyone have an idea what is the issue I'm seeing about? Or even better, how to fix it? Can I provide any additional info that would help?
[0] https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git/comm... [1] https://openwrt.org/ [2] https://linuxcontainers.org/