On Sat, 09 Apr 2016 01:55:06 +0200 Hannes Frederic Sowa <han...@stressinduktion.org> wrote:
> > > On Sat, Apr 9, 2016, at 01:24, Cong Wang wrote: > > On Fri, Apr 8, 2016 at 1:55 PM, Hannes Frederic Sowa > > <han...@stressinduktion.org> wrote: > > > Due to the fact that the udp socket is destructed asynchronously in a > > > work queue, we have some nondeterministic behavior during shutdown of > > > vxlan tunnels and creating new ones. Fix this by keeping the destruction > > > process synchronous in regards to the user space process so IFF_UP can > > > be reliably set. > > > > > > udp_tunnel_sock_release destroys vs->sock->sk if reference counter > > > indicates so. We expect to have the same lifetime of vxlan_sock and > > > vxlan_sock->sock->sk even in fast paths with only rcu locks held. So > > > only destruct the whole socket after we can be sure it cannot be found > > > by searching vxlan_net->sock_list. > > > > > > > I am wondering what is the reason why we used work queue from > > the beginning? > > I actually don't know. It was like that from the beginning. I cc'ed > Stephen, maybe he remembers? > > Bye, > Hannes The problem was that VXLAN needs to update multicast settings and that can't be done under RTNL.
