From 00a40d809207a61f0762488aa5ce72e941b367ce Mon Sep 17 00:00:00 2001 From: Kuniyuki Iwashima Date: Fri, 3 Jul 2026 00:09:25 +0000 Subject: [PATCH] ipvlan: Support per-netns netdev unregistration. When a lower device is unregistered, its upper ipvlan devices must also be unregistered. However, these upper devices may reside in different netns than the lower device. Let's use unregister_netdevice_queue_net() to support per-netns device unregistration for ipvlan. The new dying flag in struct ipvl_dev is used to avoid a race that ipvlan_link_delete() is called while its lower device is being removed in ipvlan_device_event(). If dying is true in ipvlan_link_delete(), the ipvlan device is already destructed but not yet unregistered. In this case, unregistration will be done in __rtnl_net_unlock() of the ->dellink() caller. Tested: 1. Create veth in ns1 and two ipvlan devices in ns2 and ns3. # ip netns add ns1 # ip netns add ns2 # ip netns add ns3 # ip -n ns1 link add veth0 type veth peer veth1 # ip -n ns2 link add ipvl2 link veth0 link-netns ns1 type ipvlan mode l2 # ip -n ns3 link add ipvl3 link veth0 link-netns ns1 type ipvlan mode l2 2. Run bpftrace to check that veth is unregistered first but wait ipvlan to be unregistered # bpftrace -e '#include kprobe:ipvlan_uninit, kprobe:veth_dellink, kprobe:free_netdev { $dev = (struct net_device *)arg0; printf("PID: %d | DEV: %s%s\n", pid, $dev->name, kstack()); }' 3. Remove the lower veth0 in ns1. # ip -n ns1 link del veth0 We can see that veth0 is freed after unregistering ipvl2 and ipvl3 in per-netns work because ipvl_port holds refcount of veth0. PID: 2010 | DEV: veth0 veth_dellink+5 rtnl_dellink+1213 rtnetlink_rcv_msg+1791 ... PID: 440 | DEV: ipvl2 ipvlan_uninit+5 unregister_netdevice_many_notify+7129 unregister_netdevice_many_net+1050 rtnl_net_work_func+136 process_scheduled_works+2538 ... PID: 440 | DEV: ipvl2 free_netdev+5 netdev_run_todo+4798 process_scheduled_works+2538 ... PID: 440 | DEV: ipvl3 ipvlan_uninit+5 unregister_netdevice_many_notify+7129 unregister_netdevice_many_net+1050 rtnl_net_work_func+136 process_scheduled_works+2538 ... PID: 2010 | DEV: veth0 free_netdev+5 netdev_run_todo+4798 rtnl_dellink+1507 rtnetlink_rcv_msg+1791 ... PID: 440 | DEV: ipvl3 free_netdev+5 netdev_run_todo+4798 process_scheduled_works+2538 ... Signed-off-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20260703001009.1572444-15-kuniyu@google.com Signed-off-by: Paolo Abeni --- drivers/net/ipvlan/ipvlan.h | 6 ++++-- drivers/net/ipvlan/ipvlan_main.c | 22 ++++++++++++++-------- drivers/net/ipvlan/ipvtap.c | 8 +++++--- 3 files changed, 23 insertions(+), 13 deletions(-) diff --git a/drivers/net/ipvlan/ipvlan.h b/drivers/net/ipvlan/ipvlan.h index 9d3835c14e5e..8d05ad480438 100644 --- a/drivers/net/ipvlan/ipvlan.h +++ b/drivers/net/ipvlan/ipvlan.h @@ -69,6 +69,7 @@ struct ipvl_dev { DECLARE_BITMAP(mac_filters, IPVLAN_MAC_FILTER_SIZE); netdev_features_t sfeatures; u32 msg_enable; + bool dying; }; struct ipvl_addr { @@ -169,7 +170,8 @@ void ipvlan_count_rx(const struct ipvl_dev *ipvlan, unsigned int len, bool success, bool mcast); int ipvlan_link_new(struct net_device *dev, struct rtnl_newlink_params *params, struct netlink_ext_ack *extack); -void __ipvlan_link_delete(struct net_device *dev, struct list_head *head); +void __ipvlan_link_delete(struct net *net, struct net_device *dev, + struct list_head *head); void ipvlan_link_setup(struct net_device *dev); int ipvlan_link_register(struct rtnl_link_ops *ops); #ifdef CONFIG_IPVLAN_L3S @@ -209,7 +211,7 @@ static inline bool netif_is_ipvlan_port(const struct net_device *dev) } #if IS_ENABLED(CONFIG_IPVTAP) -extern void (*__ipvtap_dellink_ptr)(struct net_device *dev, +extern void (*__ipvtap_dellink_ptr)(struct net *net, struct net_device *dev, struct list_head *head); #endif diff --git a/drivers/net/ipvlan/ipvlan_main.c b/drivers/net/ipvlan/ipvlan_main.c index 6d7479a8a9c6..ee46a55f73d1 100644 --- a/drivers/net/ipvlan/ipvlan_main.c +++ b/drivers/net/ipvlan/ipvlan_main.c @@ -8,7 +8,7 @@ #include "ipvlan.h" #if IS_ENABLED(CONFIG_IPVTAP) -void (*__ipvtap_dellink_ptr)(struct net_device *dev, +void (*__ipvtap_dellink_ptr)(struct net *net, struct net_device *dev, struct list_head *head); EXPORT_SYMBOL(__ipvtap_dellink_ptr); #endif @@ -706,7 +706,8 @@ int ipvlan_link_new(struct net_device *dev, struct rtnl_newlink_params *params, } EXPORT_SYMBOL_GPL(ipvlan_link_new); -void __ipvlan_link_delete(struct net_device *dev, struct list_head *head) +void __ipvlan_link_delete(struct net *net, struct net_device *dev, + struct list_head *head) { struct ipvl_dev *ipvlan = netdev_priv(dev); struct ipvl_addr *addr, *next; @@ -721,7 +722,7 @@ void __ipvlan_link_delete(struct net_device *dev, struct list_head *head) ida_free(&ipvlan->port->ida, dev->dev_id); list_del_rcu(&ipvlan->pnode); - unregister_netdevice_queue(dev, head); + unregister_netdevice_queue_net(net, dev, head); netdev_upper_dev_unlink(ipvlan->phy_dev, dev); } EXPORT_SYMBOL(__ipvlan_link_delete); @@ -731,7 +732,8 @@ static void ipvlan_link_delete(struct net_device *dev, struct list_head *head) struct ipvl_dev *ipvlan = netdev_priv(dev); mutex_lock(&ipvlan->port->pnodes_lock); - __ipvlan_link_delete(dev, head); + if (!ipvlan->dying) + __ipvlan_link_delete(dev_net(dev), dev, head); mutex_unlock(&ipvlan->port->pnodes_lock); } @@ -827,22 +829,26 @@ static int ipvlan_device_event(struct notifier_block *unused, ipvlan_migrate_l3s_hook(oldnet, newnet); break; } - case NETDEV_UNREGISTER: + case NETDEV_UNREGISTER: { + struct net *net = dev_net(dev); + if (dev->reg_state != NETREG_UNREGISTERING) break; list_for_each_entry_safe(ipvlan, next, &port->ipvlans, pnode) { + ipvlan->dying = true; + #if IS_ENABLED(CONFIG_IPVTAP) if (ipvlan->dev->rtnl_link_ops != &ipvlan_link_ops) - __ipvtap_dellink_ptr(ipvlan->dev, &lst_kill); + __ipvtap_dellink_ptr(net, ipvlan->dev, &lst_kill); else #endif - __ipvlan_link_delete(ipvlan->dev, &lst_kill); + __ipvlan_link_delete(net, ipvlan->dev, &lst_kill); } unregister_netdevice_many(&lst_kill); break; - + } case NETDEV_FEAT_CHANGE: list_for_each_entry(ipvlan, &port->ipvlans, pnode) { netif_inherit_tso_max(ipvlan->dev, dev); diff --git a/drivers/net/ipvlan/ipvtap.c b/drivers/net/ipvlan/ipvtap.c index 99eaa29057b4..66c949d94261 100644 --- a/drivers/net/ipvlan/ipvtap.c +++ b/drivers/net/ipvlan/ipvtap.c @@ -109,13 +109,14 @@ static int ipvtap_newlink(struct net_device *dev, return err; } -static void __ipvtap_dellink(struct net_device *dev, struct list_head *head) +static void __ipvtap_dellink(struct net *net, struct net_device *dev, + struct list_head *head) { struct ipvtap_dev *vlantap = netdev_priv(dev); netdev_rx_handler_unregister(dev); tap_del_queues(&vlantap->tap); - __ipvlan_link_delete(dev, head); + __ipvlan_link_delete(net, dev, head); } static void ipvtap_dellink(struct net_device *dev, @@ -125,7 +126,8 @@ static void ipvtap_dellink(struct net_device *dev, struct ipvl_port *port = vlantap->vlan.port; mutex_lock(&port->pnodes_lock); - __ipvtap_dellink(dev, head); + if (!vlantap->vlan.dying) + __ipvtap_dellink(dev_net(dev), dev, head); mutex_unlock(&port->pnodes_lock); }