geneve_exit_rtnl_net() iterates geneve devices whose sockets
are in the dying netns and queues them for destruction.
So the devices may reside in different netns.
Let's use unregister_netdevice_queue_net() to support per-netns
device unregistration.
list_del() is changed to list_del_init() to avoid queueing the
same device twice.
Even after geneve_exit_rtnl_net() queues a cross-netns geneve
device, geneve_dellink() can be called concurrently for it.
In such a case, __rtnl_net_unlock() will perform the unregistration.
Note that geneve uses register_pernet_subsys() instead of _device(),
so default_device_exit_batch() guarantees that the async per-netns
works are flushed before ->exit().
Tested:
1. Create geneve device across two netns.
# ip netns add ns1
# ip netns add ns2
# ip -n ns1 link add geneve0 link-netns ns2 type geneve external
2. Run bpftrace to check that geneve_uninit() is called between
->exit_rtnl() and ->exit().
# bpftrace -e '#include <linux/netdevice.h>
kprobe:geneve_uninit {
$dev = (struct net_device *)arg0;
printf("PID: %d | DEV: %s%s\n", pid, $dev->name, kstack());
}
kprobe:geneve_exit_rtnl_net,
kprobe:geneve_exit_net {
printf("PID: %d%s\n", pid, kstack());
}'
3. Remove the netns where the geneve socket resides
# ip netns del ns2
Now, we can see geneve0 is unregistered by per-netns work
instead of cleanup_net() and it finishes before ->exit() to
avoid WARN_ON_ONCE(!list_empty(&gn->sock_list)) there.
PID: 571
geneve_exit_rtnl_net+5
ops_undo_list+702
cleanup_net+1122
process_scheduled_works+2538
...
PID: 1047 | DEV: geneve0
geneve_uninit+5
unregister_netdevice_many_notify+7129
unregister_netdevice_many_net+1050
rtnl_net_work_func+136
process_scheduled_works+2538
...
PID: 571
geneve_exit_net+5
ops_undo_list+1064
cleanup_net+1122
process_scheduled_works+2538
...
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20260731164612.2148830-4-kuniyu@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
ccb161b71a