From ccb161b71a1f5ac2cb97d301cd6942e3d1c8908d Mon Sep 17 00:00:00 2001 From: Kuniyuki Iwashima Date: Fri, 31 Jul 2026 16:45:55 +0000 Subject: [PATCH] geneve: Support per-netns netdev unregistration. 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 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 Link: https://patch.msgid.link/20260731164612.2148830-4-kuniyu@google.com Signed-off-by: Paolo Abeni --- drivers/net/geneve.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/drivers/net/geneve.c b/drivers/net/geneve.c index f456a85dca77..a6a8978e3b81 100644 --- a/drivers/net/geneve.c +++ b/drivers/net/geneve.c @@ -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); }