[PATCH v1 net-next 0/3] geneve: Support per-netns device unregistration.

[PATCH v1 net-next 0/3] geneve: Support per-netns device unregistration.

[Kuniyuki Iwashima]

Patch 1 is a prep patch to make patch 2 clean, which
adds a per-netns mutex for geneve linked lists.

Patch 3 supports per-netns netdev unreg by using
unregister_netdevice_queue_net().


Kuniyuki Iwashima (3):
  geneve: Unlink geneve->sock[46].hlist[46].hlist in
    __geneve_sock_release().
  geneve: Protect geneve_net and geneve_sock with per-netns mutex.
  geneve: Support per-netns netdev unregistration.

 drivers/net/geneve.c | 126 ++++++++++++++++++++++++++++++++-----------
 1 file changed, 95 insertions(+), 31 deletions(-)

-- 
2.55.0.571.g244d577d93-goog

[PATCH v1 net-next 1/3] geneve: Unlink geneve->sock[46].hlist[46].hlist in __geneve_sock_release().

[Kuniyuki Iwashima]

Currently, geneve->sock[46].hlist[46] is unliked from
geneve_sock.vni_list in geneve_stop() and geneve_sock.refcnt is
decremented for each socket later in __geneve_sock_release().

The following patch will introduce a mutex in geneve_net to
protect geneve_sock.{refcnt,vni_list}.

However, udp_tunnel_notify_del_rx_port() must be outside of the
lock to avoid AB-BA deadlock.

To make the change cleaner, let's move hlist_del_init_rcu()
from geneve_stop() to __geneve_sock_release().

Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
---
 drivers/net/geneve.c | 42 +++++++++++++++++++++++++-----------------
 1 file changed, 25 insertions(+), 17 deletions(-)

diff --git a/drivers/net/geneve.c b/drivers/net/geneve.c
index 542e53f9dc3e..bd4fc6dba2fa 100644
--- a/drivers/net/geneve.c
+++ b/drivers/net/geneve.c
@@ -1052,9 +1052,30 @@ static struct geneve_sock *geneve_socket_create(struct net *net,
 	return gs;
 }
 
-static void __geneve_sock_release(struct geneve_sock *gs)
+static void __geneve_sock_release(struct geneve_dev *geneve, bool ipv6)
 {
-	if (!gs || --gs->refcnt)
+	struct geneve_dev_node *node;
+	struct geneve_sock *gs;
+
+#if IS_ENABLED(CONFIG_IPV6)
+	if (ipv6) {
+		gs = rtnl_dereference(geneve->sock6);
+		rcu_assign_pointer(geneve->sock6, NULL);
+		node = &geneve->hlist6;
+	} else
+#endif
+	{
+		gs = rtnl_dereference(geneve->sock4);
+		rcu_assign_pointer(geneve->sock4, NULL);
+		node = &geneve->hlist4;
+	}
+
+	if (!gs)
+		return;
+
+	hlist_del_init_rcu(&node->hlist);
+
+	if (--gs->refcnt)
 		return;
 
 	list_del(&gs->list);
@@ -1065,19 +1086,10 @@ static void __geneve_sock_release(struct geneve_sock *gs)
 
 static void geneve_sock_release(struct geneve_dev *geneve)
 {
-	struct geneve_sock *gs4 = rtnl_dereference(geneve->sock4);
 #if IS_ENABLED(CONFIG_IPV6)
-	struct geneve_sock *gs6 = rtnl_dereference(geneve->sock6);
-
-	rcu_assign_pointer(geneve->sock6, NULL);
-#endif
-
-	rcu_assign_pointer(geneve->sock4, NULL);
-
-	__geneve_sock_release(gs4);
-#if IS_ENABLED(CONFIG_IPV6)
-	__geneve_sock_release(gs6);
+	__geneve_sock_release(geneve, true);
 #endif
+	__geneve_sock_release(geneve, false);
 }
 
 static struct geneve_sock *geneve_find_sock(struct net *net,
@@ -1187,10 +1199,6 @@ static int geneve_stop(struct net_device *dev)
 {
 	struct geneve_dev *geneve = netdev_priv(dev);
 
-	hlist_del_init_rcu(&geneve->hlist4.hlist);
-#if IS_ENABLED(CONFIG_IPV6)
-	hlist_del_init_rcu(&geneve->hlist6.hlist);
-#endif
 	geneve_sock_release(geneve);
 	return 0;
 }
-- 
2.55.0.571.g244d577d93-goog

[PATCH v1 net-next 2/3] geneve: Protect geneve_net and geneve_sock with per-netns mutex.

[Kuniyuki Iwashima]

struct geneve_dev.net is the netns where the backend geneve
socket resides.

struct geneve_dev is linked to the geneve_net.geneve_list of
the socket's netns.

During netns dismantle or module unload, geneve_exit_rtnl_net()
iterates the list and queues devices for destruction regardless
of devices' netns.

Moreover, a socket can be shared by multiple geneve devices in
different netns, and geneve_open() and geneve_stop() modify
geneve_sock.vni_list and geneve_net.sock_list.

Thus, once RTNL is removed, the three lists can be modified
concurrently from different netns due to device removal and
link-up/down.

Let's protect them with per-netns mutex.

geneve_newlink() is still protected by rtnl_net_lock()s, so
acquiring gn->lock twice in geneve_find_dev() and
geneve_configure() is not a problem.

Note that udp_tunnel_notify_add_rx_port() is moved outside of
the mutex, otherwise gn->lock -> utn->lock ordering would trigger
AB-BA deadlock in geneve_offload_rx_ports(), which acquires
gn->lock under utn->lock.  Even without gn->lock, geneve_sock_add()
and geneve_offload_rx_ports() are still serialised with (per-netns)
RTNL, so there is no race.

Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
---
 drivers/net/geneve.c | 82 ++++++++++++++++++++++++++++++++++++--------
 1 file changed, 68 insertions(+), 14 deletions(-)

diff --git a/drivers/net/geneve.c b/drivers/net/geneve.c
index bd4fc6dba2fa..f456a85dca77 100644
--- a/drivers/net/geneve.c
+++ b/drivers/net/geneve.c
@@ -69,8 +69,8 @@ struct geneve_skb_cb {
 /* per-network namespace private data for this module */
 struct geneve_net {
 	struct list_head	geneve_list;
-	/* sock_list is protected by rtnl lock */
 	struct list_head	sock_list;
+	struct mutex		lock;
 };
 
 static unsigned int geneve_net_id;
@@ -1035,9 +1035,6 @@ static struct geneve_sock *geneve_socket_create(struct net *net,
 	for (h = 0; h < VNI_HASH_SIZE; ++h)
 		INIT_HLIST_HEAD(&gs->vni_list[h]);
 
-	/* Initialize the geneve udp offloads structure */
-	udp_tunnel_notify_add_rx_port(sk, UDP_TUNNEL_TYPE_GENEVE);
-
 	/* Mark socket as an encapsulation socket */
 	memset(&tunnel_cfg, 0, sizeof(tunnel_cfg));
 	tunnel_cfg.sk_user_data = gs;
@@ -1056,6 +1053,7 @@ static void __geneve_sock_release(struct geneve_dev *geneve, bool ipv6)
 {
 	struct geneve_dev_node *node;
 	struct geneve_sock *gs;
+	struct geneve_net *gn;
 
 #if IS_ENABLED(CONFIG_IPV6)
 	if (ipv6) {
@@ -1073,12 +1071,19 @@ static void __geneve_sock_release(struct geneve_dev *geneve, bool ipv6)
 	if (!gs)
 		return;
 
+	gn = net_generic(sock_net(gs->sk), geneve_net_id);
+	mutex_lock(&gn->lock);
+
 	hlist_del_init_rcu(&node->hlist);
 
-	if (--gs->refcnt)
+	if (--gs->refcnt) {
+		mutex_unlock(&gn->lock);
 		return;
+	}
 
 	list_del(&gs->list);
+	mutex_unlock(&gn->lock);
+
 	udp_tunnel_notify_del_rx_port(gs->sk, UDP_TUNNEL_TYPE_GENEVE);
 	udp_tunnel_sock_release(gs->sk);
 	kfree_rcu(gs, rcu);
@@ -1135,22 +1140,31 @@ static int geneve_sock_add(struct geneve_dev *geneve,
 	struct net *net = geneve->net;
 	struct geneve_dev_node *node;
 	struct geneve_sock *gs;
+	struct geneve_net *gn;
+	bool created = false;
 	__u8 vni[3];
+	int ret = 0;
 	__u32 hash;
 
+	gn = net_generic(net, geneve_net_id);
+	mutex_lock(&gn->lock);
+
 	gs = geneve_find_sock(net, geneve, cfg, ipv6);
 	if (gs) {
 		gs->refcnt++;
-		goto out;
-	}
+	} else {
+		gs = geneve_socket_create(net, geneve, cfg, ipv6);
+		if (IS_ERR(gs)) {
+			ret = PTR_ERR(gs);
+			goto out;
+		}
 
-	gs = geneve_socket_create(net, geneve, cfg, ipv6);
-	if (IS_ERR(gs))
-		return PTR_ERR(gs);
+		created = true;
+	}
 
-out:
 	gs->collect_md = cfg->collect_md;
 	gs->gro_hint = cfg->gro_hint;
+
 #if IS_ENABLED(CONFIG_IPV6)
 	if (ipv6) {
 		rcu_assign_pointer(geneve->sock6, gs);
@@ -1166,7 +1180,16 @@ static int geneve_sock_add(struct geneve_dev *geneve,
 	tunnel_id_to_vni(cfg->info.key.tun_id, vni);
 	hash = geneve_net_vni_hash(vni);
 	hlist_add_head_rcu(&node->hlist, &gs->vni_list[hash]);
-	return 0;
+
+out:
+	mutex_unlock(&gn->lock);
+
+	if (created) {
+		/* Initialize the geneve udp offloads structure */
+		udp_tunnel_notify_add_rx_port(gs->sk, UDP_TUNNEL_TYPE_GENEVE);
+	}
+
+	return ret;
 }
 
 static int geneve_open(struct net_device *dev)
@@ -1743,6 +1766,8 @@ static void geneve_offload_rx_ports(struct net_device *dev, bool push)
 
 	ASSERT_RTNL();
 
+	mutex_lock(&gn->lock);
+
 	list_for_each_entry(gs, &gn->sock_list, list) {
 		if (push) {
 			udp_tunnel_push_rx_port(dev, gs->sk,
@@ -1752,6 +1777,8 @@ static void geneve_offload_rx_ports(struct net_device *dev, bool push)
 						UDP_TUNNEL_TYPE_GENEVE);
 		}
 	}
+
+	mutex_unlock(&gn->lock);
 }
 
 static struct geneve_config *geneve_config_alloc(const struct geneve_config *src)
@@ -1968,6 +1995,9 @@ static struct geneve_dev *geneve_find_dev(struct geneve_net *gn,
 
 	*tun_on_same_port = false;
 	*tun_collect_md = false;
+
+	mutex_lock(&gn->lock);
+
 	list_for_each_entry(geneve, &gn->geneve_list, next) {
 		const struct geneve_config *gcfg = rtnl_dereference(geneve->cfg);
 
@@ -1982,6 +2012,9 @@ static struct geneve_dev *geneve_find_dev(struct geneve_net *gn,
 		    !memcmp(&info->key.u, &gcfg->info.key.u, sizeof(info->key.u)))
 			t = geneve;
 	}
+
+	mutex_unlock(&gn->lock);
+
 	return t;
 }
 
@@ -2076,7 +2109,10 @@ static int geneve_configure(struct net *net, struct net_device *dev,
 		return err;
 	}
 
+	mutex_lock(&gn->lock);
 	list_add(&geneve->next, &gn->geneve_list);
+	mutex_unlock(&gn->lock);
+
 	return 0;
 }
 
@@ -2466,7 +2502,7 @@ 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_device *dev, struct list_head *head)
 {
 	struct geneve_dev *geneve = netdev_priv(dev);
 
@@ -2474,6 +2510,18 @@ static void geneve_dellink(struct net_device *dev, struct list_head *head)
 	unregister_netdevice_queue(dev, head);
 }
 
+static void geneve_dellink(struct net_device *dev, struct list_head *head)
+{
+	struct geneve_dev *geneve = netdev_priv(dev);
+	struct geneve_net *gn;
+
+	gn = net_generic(geneve->net, geneve_net_id);
+
+	mutex_lock(&gn->lock);
+	__geneve_dellink(dev, head);
+	mutex_unlock(&gn->lock);
+}
+
 static size_t geneve_get_size(const struct net_device *dev)
 {
 	return nla_total_size(sizeof(__u32)) +	/* IFLA_GENEVE_ID */
@@ -2692,6 +2740,8 @@ static __net_init int geneve_init_net(struct net *net)
 
 	INIT_LIST_HEAD(&gn->geneve_list);
 	INIT_LIST_HEAD(&gn->sock_list);
+	mutex_init(&gn->lock);
+
 	return 0;
 }
 
@@ -2701,8 +2751,12 @@ static void __net_exit geneve_exit_rtnl_net(struct net *net,
 	struct geneve_net *gn = net_generic(net, geneve_net_id);
 	struct geneve_dev *geneve, *next;
 
+	mutex_lock(&gn->lock);
+
 	list_for_each_entry_safe(geneve, next, &gn->geneve_list, next)
-		geneve_dellink(geneve->dev, dev_to_kill);
+		__geneve_dellink(geneve->dev, dev_to_kill);
+
+	mutex_unlock(&gn->lock);
 }
 
 static void __net_exit geneve_exit_net(struct net *net)
-- 
2.55.0.571.g244d577d93-goog

[PATCH v1 net-next 3/3] geneve: Support per-netns netdev unregistration.

[Kuniyuki Iwashima]

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>
---
 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);
 }
-- 
2.55.0.571.g244d577d93-goog

Re: [PATCH v1 net-next 3/3] geneve: Support per-netns netdev unregistration.

[Paolo Abeni]

On 7/31/26 6:45 PM, Kuniyuki Iwashima wrote:
> 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>
> ---
>  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);

Sashiko noted that the lockdep chain between dev->lock, utn->loc and
gn->lock is not trivial, possibly a documentation follow-up would be useful

>  	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);

Here sashiko foresees some problem with CONFIG_DEBUG_NET_SMALL_RTNL
before full conversion to per netns lock even of ovs. Just more
follow-up, I guess.

/P

>  
>  	mutex_unlock(&gn->lock);
>  }

Re: [PATCH v1 net-next 0/3] geneve: Support per-netns device unregistration.

[patchwork-bot+netdevbpf]

Hello:

This series was applied to netdev/net-next.git (main)
by Paolo Abeni <pabeni@redhat.com>:

On Fri, 31 Jul 2026 16:45:52 +0000 you wrote:
> Patch 1 is a prep patch to make patch 2 clean, which
> adds a per-netns mutex for geneve linked lists.
> 
> Patch 3 supports per-netns netdev unreg by using
> unregister_netdevice_queue_net().
> 
> 
> [...]

Here is the summary with links:
  - [v1,net-next,1/3] geneve: Unlink geneve->sock[46].hlist[46].hlist in __geneve_sock_release().
    https://git.kernel.org/netdev/net-next/c/cf31c7f186ed
  - [v1,net-next,2/3] geneve: Protect geneve_net and geneve_sock with per-netns mutex.
    https://git.kernel.org/netdev/net-next/c/7df47efd6db1
  - [v1,net-next,3/3] geneve: Support per-netns netdev unregistration.
    https://git.kernel.org/netdev/net-next/c/ccb161b71a1f

You are awesome, thank you!
-- 
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html

Re: [PATCH v1 net-next 3/3] geneve: Support per-netns netdev unregistration.

[Kuniyuki Iwashima]

On Tue, Aug 4, 2026 at 6:47 AM Paolo Abeni <pabeni@redhat.com> wrote:
>
> On 7/31/26 6:45 PM, Kuniyuki Iwashima wrote:
> > 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>
> > ---
> >  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);
>
> Sashiko noted that the lockdep chain between dev->lock, utn->loc and
> gn->lock is not trivial, possibly a documentation follow-up would be useful
>
> >       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);
>
> Here sashiko foresees some problem with CONFIG_DEBUG_NET_SMALL_RTNL
> before full conversion to per netns lock even of ovs. Just more
> follow-up, I guess.

Is it Sashiko-nipa output ?
I can't find the comments from patchwork.
https://patchwork.kernel.org/project/netdevbpf/patch/20260731164612.2148830-2-kuniyu@google.com/
https://sashiko.dev/#/patchset/20260731164612.2148830-1-kuniyu@google.com

btw, I was hoping this series would land upstream so that
I don't need to care about OVS :)
https://lore.kernel.org/netdev/20260513183559.2141010-1-i.maximets@ovn.org/


>
> /P
>
> >
> >       mutex_unlock(&gn->lock);
> >  }
>

Re: [PATCH v1 net-next 3/3] geneve: Support per-netns netdev unregistration.

[Ilya Maximets]

On 8/4/26 5:24 PM, Kuniyuki Iwashima wrote:
> On Tue, Aug 4, 2026 at 6:47 AM Paolo Abeni <pabeni@redhat.com> wrote:
>>
>> On 7/31/26 6:45 PM, Kuniyuki Iwashima wrote:
>>> 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>
>>> ---
>>>  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);
>>
>> Sashiko noted that the lockdep chain between dev->lock, utn->loc and
>> gn->lock is not trivial, possibly a documentation follow-up would be useful
>>
>>>       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);
>>
>> Here sashiko foresees some problem with CONFIG_DEBUG_NET_SMALL_RTNL
>> before full conversion to per netns lock even of ovs. Just more
>> follow-up, I guess.
> 
> Is it Sashiko-nipa output ?
> I can't find the comments from patchwork.
> https://patchwork.kernel.org/project/netdevbpf/patch/20260731164612.2148830-2-kuniyu@google.com/
> https://sashiko.dev/#/patchset/20260731164612.2148830-1-kuniyu@google.com
> 
> btw, I was hoping this series would land upstream so that
> I don't need to care about OVS :)
> https://lore.kernel.org/netdev/20260513183559.2141010-1-i.maximets@ovn.org/
FWIW, I have the non-RFC version of this set prepared.  I can post it,
if that helps.

Best regards, Ilya Maximets.

Re: [PATCH v1 net-next 3/3] geneve: Support per-netns netdev unregistration.

[Paolo Abeni]

On 8/4/26 5:24 PM, Kuniyuki Iwashima wrote:
> On Tue, Aug 4, 2026 at 6:47 AM Paolo Abeni <pabeni@redhat.com> wrote:
>> On 7/31/26 6:45 PM, Kuniyuki Iwashima wrote:
>>> 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>
>>> ---
>>>  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);
>>
>> Sashiko noted that the lockdep chain between dev->lock, utn->loc and
>> gn->lock is not trivial, possibly a documentation follow-up would be useful
>>
>>>       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);
>>
>> Here sashiko foresees some problem with CONFIG_DEBUG_NET_SMALL_RTNL
>> before full conversion to per netns lock even of ovs. Just more
>> follow-up, I guess.
> 
> Is it Sashiko-nipa output ?

Yes, sorry I should have included the link:

https://netdev-ai.bots.linux.dev/sashiko/#/patchset/20260731164612.2148830-1-kuniyu%40google.com

sometimes PW reports a timeout, but the report is still available via
the sashiko nipa UI. You can search for the patch title in:

https://netdev-ai.bots.linux.dev/sashiko/

alike the gemini instance.

/P

Re: [PATCH v1 net-next 3/3] geneve: Support per-netns netdev unregistration.

[Kuniyuki Iwashima]

On Tue, Aug 4, 2026 at 10:34 AM Paolo Abeni <pabeni@redhat.com> wrote:
>
> On 8/4/26 5:24 PM, Kuniyuki Iwashima wrote:
> > On Tue, Aug 4, 2026 at 6:47 AM Paolo Abeni <pabeni@redhat.com> wrote:
> >> On 7/31/26 6:45 PM, Kuniyuki Iwashima wrote:
> >>> 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>
> >>> ---
> >>>  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);
> >>
> >> Sashiko noted that the lockdep chain between dev->lock, utn->loc and
> >> gn->lock is not trivial, possibly a documentation follow-up would be useful
> >>
> >>>       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);
> >>
> >> Here sashiko foresees some problem with CONFIG_DEBUG_NET_SMALL_RTNL
> >> before full conversion to per netns lock even of ovs. Just more
> >> follow-up, I guess.
> >
> > Is it Sashiko-nipa output ?
>
> Yes, sorry I should have included the link:
>
> https://netdev-ai.bots.linux.dev/sashiko/#/patchset/20260731164612.2148830-1-kuniyu%40google.com
>
> sometimes PW reports a timeout, but the report is still available via
> the sashiko nipa UI.

Ah, good to know that, I gave up looking for it due to the timeout log.

Thanks !


> You can search for the patch title in:
>
> https://netdev-ai.bots.linux.dev/sashiko/
>
> alike the gemini instance.
>
> /P
>

Re: [PATCH v1 net-next 3/3] geneve: Support per-netns netdev unregistration.

[Kuniyuki Iwashima]

On Tue, Aug 4, 2026 at 8:35 AM Ilya Maximets <i.maximets@ovn.org> wrote:
>
> On 8/4/26 5:24 PM, Kuniyuki Iwashima wrote:
> > On Tue, Aug 4, 2026 at 6:47 AM Paolo Abeni <pabeni@redhat.com> wrote:
> >>
> >> On 7/31/26 6:45 PM, Kuniyuki Iwashima wrote:
> >>> 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>
> >>> ---
> >>>  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);
> >>
> >> Sashiko noted that the lockdep chain between dev->lock, utn->loc and
> >> gn->lock is not trivial, possibly a documentation follow-up would be useful
> >>
> >>>       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);
> >>
> >> Here sashiko foresees some problem with CONFIG_DEBUG_NET_SMALL_RTNL
> >> before full conversion to per netns lock even of ovs. Just more
> >> follow-up, I guess.
> >
> > Is it Sashiko-nipa output ?
> > I can't find the comments from patchwork.
> > https://patchwork.kernel.org/project/netdevbpf/patch/20260731164612.2148830-2-kuniyu@google.com/
> > https://sashiko.dev/#/patchset/20260731164612.2148830-1-kuniyu@google.com
> >
> > btw, I was hoping this series would land upstream so that
> > I don't need to care about OVS :)
> > https://lore.kernel.org/netdev/20260513183559.2141010-1-i.maximets@ovn.org/
> FWIW, I have the non-RFC version of this set prepared.  I can post it,
> if that helps.

Yes, that would be nice, thanks !