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geneve: Support per-netns netdev unregistration.

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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>
This commit is contained in:
Kuniyuki Iwashima
2026-07-31 16:45:55 +00:00
committed by Paolo Abeni
parent 7df47efd6d
commit ccb161b71a
1 changed files with 7 additions and 5 deletions
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12
drivers/net/geneve.c
View File

@@ -2502,12 +2502,13 @@ static int geneve_changelink(struct net_device *dev, struct nlattr *tb[],
return err;
}
static void __geneve_dellink(struct net_device *dev, struct list_head *head)
static void __geneve_dellink(struct net *net, struct net_device *dev,
struct list_head *head)
{
struct geneve_dev *geneve = netdev_priv(dev);
list_del(&geneve->next);
unregister_netdevice_queue(dev, head);
list_del_init(&geneve->next);
unregister_netdevice_queue_net(net, dev, head);
}
static void geneve_dellink(struct net_device *dev, struct list_head *head)
@@ -2518,7 +2519,8 @@ static void geneve_dellink(struct net_device *dev, struct list_head *head)
gn = net_generic(geneve->net, geneve_net_id);
mutex_lock(&gn->lock);
__geneve_dellink(dev, head);
if (!list_empty(&geneve->next))
__geneve_dellink(dev_net(dev), dev, head);
mutex_unlock(&gn->lock);
}
@@ -2754,7 +2756,7 @@ static void __net_exit geneve_exit_rtnl_net(struct net *net,
mutex_lock(&gn->lock);
list_for_each_entry_safe(geneve, next, &gn->geneve_list, next)
__geneve_dellink(geneve->dev, dev_to_kill);
__geneve_dellink(net, geneve->dev, dev_to_kill);
mutex_unlock(&gn->lock);
}