On Thu, Feb 15, 2018 at 03:31:45PM -0500, David Miller wrote: > From: Xin Long <lucien....@gmail.com> > Date: Wed, 14 Feb 2018 19:06:02 +0800 > > > In early time, when freeing a xdst, it would be inserted into > > dst_garbage.list first. Then if it's refcnt was still held > > somewhere, later it would be put into dst_busy_list in > > dst_gc_task(). > > > > When one dev was being unregistered, the dev of these dsts in > > dst_busy_list would be set with loopback_dev and put this dev. > > So that this dev's removal wouldn't get blocked, and avoid the > > kmsg warning: > > > > kernel:unregister_netdevice: waiting for veth0 to become \ > > free. Usage count = 2 > > > > However after Commit 52df157f17e5 ("xfrm: take refcnt of dst > > when creating struct xfrm_dst bundle"), the xdst will not be > > freed with dst gc, and this warning happens. > > > > To fix it, we need to find these xdsts that are still held by > > others when removing the dev, and free xdst's dev and set it > > with loopback_dev. > > > > But unfortunately after flow_cache for xfrm was deleted, no > > list tracks them anymore. So we need to save these xdsts > > somewhere to release the xdst's dev later. > > > > To make this easier, this patch is to reuse uncached_list to > > track xdsts, so that the dev refcnt can be released in the > > event NETDEV_UNREGISTER process of fib_netdev_notifier. > > > > Thanks to Florian, we could move forward this fix quickly. > > > > Fixes: 52df157f17e5 ("xfrm: take refcnt of dst when creating struct > > xfrm_dst bundle") > > Reported-by: Jianlin Shi <ji...@redhat.com> > > Reported-by: Hangbin Liu <liuhang...@gmail.com> > > Tested-by: Eyal Birger <eyal.bir...@gmail.com> > > Signed-off-by: Xin Long <lucien....@gmail.com> > > Steffen, I assume you will take this via your ipsec tree?
Yes, this is applied to the ipsec tree now. Thanks a lot everyone!