From 23aff4ed78c248d0e86966606c465d5505469eb5 Mon Sep 17 00:00:00 2001 From: Kuniyuki Iwashima Date: Fri, 31 Jul 2026 22:43:41 +0000 Subject: [PATCH] pfcp: Support per-netns netdev unregistration. pfcp_net_exit_rtnl() iterates pfcp 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 pfcp_net_exit_rtnl() queues a cross-netns pfcp device, pfcp_dellink() could be called concurrently for it (once RTNL is removed). In such a case, __rtnl_net_unlock() will perform the unregistration. We can see pfcp0 below is unregistered by the per-netns work instead of cleanup_net(). # bpftrace -e '#include kprobe:pfcp_dev_uninit { $dev = (struct net_device *)arg0; printf("PID: %d | DEV: %s%s\n", pid, $dev->name, kstack()); } kprobe:pfcp_net_exit_rtnl { printf("PID: %d%s\n", pid, kstack()); }' & # ip netns add ns1 # ip netns add ns2 # ip -n ns1 link add pfcp0 link-netns ns2 type pfcp # ip netns del ns2 PID: 12 pfcp_net_exit_rtnl+5 ops_undo_list+702 cleanup_net+1122 process_scheduled_works+2538 ... PID: 462 | DEV: pfcp0 pfcp_dev_uninit+5 unregister_netdevice_many_notify+7129 unregister_netdevice_many_net+1050 rtnl_net_work_func+136 process_scheduled_works+2538 Signed-off-by: Kuniyuki Iwashima Reviewed-by: Simon Horman Link: https://patch.msgid.link/20260731224406.2444121-3-kuniyu@google.com Signed-off-by: Jakub Kicinski --- drivers/net/pfcp.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/drivers/net/pfcp.c b/drivers/net/pfcp.c index 45f9c5d3cb20..e1cca779d2ec 100644 --- a/drivers/net/pfcp.c +++ b/drivers/net/pfcp.c @@ -227,12 +227,13 @@ static int pfcp_newlink(struct net_device *dev, return err; } -static void __pfcp_dellink(struct net_device *dev, struct list_head *head) +static void __pfcp_dellink(struct net *net, struct net_device *dev, + struct list_head *head) { struct pfcp_dev *pfcp = netdev_priv(dev); - list_del(&pfcp->list); - unregister_netdevice_queue(dev, head); + list_del_init(&pfcp->list); + unregister_netdevice_queue_net(net, dev, head); } static void pfcp_dellink(struct net_device *dev, struct list_head *head) @@ -243,7 +244,8 @@ static void pfcp_dellink(struct net_device *dev, struct list_head *head) pn = net_generic(pfcp->net, pfcp_net_id); mutex_lock(&pn->lock); - __pfcp_dellink(dev, head); + if (!list_empty(&pfcp->list)) + __pfcp_dellink(dev_net(dev), dev, head); mutex_unlock(&pn->lock); } @@ -274,7 +276,7 @@ static void __net_exit pfcp_net_exit_rtnl(struct net *net, mutex_lock(&pn->lock); list_for_each_entry_safe(pfcp, pfcp_next, &pn->pfcp_dev_list, list) - __pfcp_dellink(pfcp->dev, dev_to_kill); + __pfcp_dellink(net, pfcp->dev, dev_to_kill); mutex_unlock(&pn->lock); }