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ipvlan: Support per-netns netdev unregistration.

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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 <linux/netdevice.h>
  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 <kuniyu@google.com>
Link: https://patch.msgid.link/20260703001009.1572444-15-kuniyu@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
This commit is contained in:
Kuniyuki Iwashima
2026-07-03 00:09:25 +00:00
committed by Paolo Abeni
parent 35add1093e
commit 00a40d8092
3 changed files with 23 additions and 13 deletions
Download Patch File Download Diff File Expand all files Collapse all files

6
drivers/net/ipvlan/ipvlan.h
View File

@@ -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

22
drivers/net/ipvlan/ipvlan_main.c
View File

@@ -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);

8
drivers/net/ipvlan/ipvtap.c
View File

@@ -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);
}