Merge branch 'net-followup-series-for-exit_rtnl'

Kuniyuki Iwashima says:

====================
net: Followup series for ->exit_rtnl().

Patch 1 drops the hold_rtnl arg in ops_undo_list() as suggested by Jakub.
Patch 2 & 3 apply ->exit_rtnl() to pfcp and ppp.

v1: https://lore.kernel.org/20250415022258.11491-1-kuniyu@amazon.com
====================

Link: https://patch.msgid.link/20250418003259.48017-1-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Author: kuba-moo

drivers/net/pfcp.c

@@ -245,30 +245,21 @@ static int __net_init pfcp_net_init(struct net *net)
 	return 0;
 }
 
-static void __net_exit pfcp_net_exit(struct net *net)
+static void __net_exit pfcp_net_exit_rtnl(struct net *net,
+					  struct list_head *dev_to_kill)
 {
 	struct pfcp_net *pn = net_generic(net, pfcp_net_id);
 	struct pfcp_dev *pfcp, *pfcp_next;
-	struct net_device *dev;
-	LIST_HEAD(list);
-
-	rtnl_lock();
-	for_each_netdev(net, dev)
-		if (dev->rtnl_link_ops == &pfcp_link_ops)
-			pfcp_dellink(dev, &list);
 
 	list_for_each_entry_safe(pfcp, pfcp_next, &pn->pfcp_dev_list, list)
-		pfcp_dellink(pfcp->dev, &list);
-
-	unregister_netdevice_many(&list);
-	rtnl_unlock();
+		pfcp_dellink(pfcp->dev, dev_to_kill);
 }
 
 static struct pernet_operations pfcp_net_ops = {
-	.init	= pfcp_net_init,
-	.exit	= pfcp_net_exit,
-	.id	= &pfcp_net_id,
-	.size	= sizeof(struct pfcp_net),
+	.init = pfcp_net_init,
+	.exit_rtnl = pfcp_net_exit_rtnl,
+	.id = &pfcp_net_id,
+	.size = sizeof(struct pfcp_net),
 };
 
 static int __init pfcp_init(void)

drivers/net/ppp/ppp_generic.c

@@ -1131,6 +1131,8 @@ static const struct file_operations ppp_device_fops = {
 	.llseek		= noop_llseek,
 };
 
+static void ppp_nl_dellink(struct net_device *dev, struct list_head *head);
+
 static __net_init int ppp_init_net(struct net *net)
 {
 	struct ppp_net *pn = net_generic(net, ppp_net_id);
@@ -1146,28 +1148,20 @@ static __net_init int ppp_init_net(struct net *net)
 	return 0;
 }
 
-static __net_exit void ppp_exit_net(struct net *net)
+static __net_exit void ppp_exit_rtnl_net(struct net *net,
+					 struct list_head *dev_to_kill)
 {
 	struct ppp_net *pn = net_generic(net, ppp_net_id);
-	struct net_device *dev;
-	struct net_device *aux;
 	struct ppp *ppp;
-	LIST_HEAD(list);
 	int id;
 
-	rtnl_lock();
-	for_each_netdev_safe(net, dev, aux) {
-		if (dev->netdev_ops == &ppp_netdev_ops)
-			unregister_netdevice_queue(dev, &list);
-	}
-
 	idr_for_each_entry(&pn->units_idr, ppp, id)
-		/* Skip devices already unregistered by previous loop */
-		if (!net_eq(dev_net(ppp->dev), net))
-			unregister_netdevice_queue(ppp->dev, &list);
+		ppp_nl_dellink(ppp->dev, dev_to_kill);
+}
 
-	unregister_netdevice_many(&list);
-	rtnl_unlock();
+static __net_exit void ppp_exit_net(struct net *net)
+{
+	struct ppp_net *pn = net_generic(net, ppp_net_id);
 
 	mutex_destroy(&pn->all_ppp_mutex);
 	idr_destroy(&pn->units_idr);
@@ -1177,6 +1171,7 @@ static __net_exit void ppp_exit_net(struct net *net)
 
 static struct pernet_operations ppp_net_ops = {
 	.init = ppp_init_net,
+	.exit_rtnl = ppp_exit_rtnl_net,
 	.exit = ppp_exit_net,
 	.id   = &ppp_net_id,
 	.size = sizeof(struct ppp_net),

net/core/net_namespace.c

@@ -220,17 +220,20 @@ static void ops_free_list(const struct pernet_operations *ops,
 static void ops_undo_list(const struct list_head *ops_list,
 			  const struct pernet_operations *ops,
 			  struct list_head *net_exit_list,
-			  bool expedite_rcu, bool hold_rtnl)
+			  bool expedite_rcu)
 {
 	const struct pernet_operations *saved_ops;
+	bool hold_rtnl = false;
 
 	if (!ops)
 		ops = list_entry(ops_list, typeof(*ops), list);
 
 	saved_ops = ops;
 
-	list_for_each_entry_continue_reverse(ops, ops_list, list)
+	list_for_each_entry_continue_reverse(ops, ops_list, list) {
+		hold_rtnl |= !!ops->exit_rtnl;
 		ops_pre_exit_list(ops, net_exit_list);
+	}
 
 	/* Another CPU might be rcu-iterating the list, wait for it.
 	 * This needs to be before calling the exit() notifiers, so the
@@ -257,11 +260,10 @@ static void ops_undo_list(const struct list_head *ops_list,
 static void ops_undo_single(struct pernet_operations *ops,
 			    struct list_head *net_exit_list)
 {
-	bool hold_rtnl = !!ops->exit_rtnl;
 	LIST_HEAD(ops_list);
 
 	list_add(&ops->list, &ops_list);
-	ops_undo_list(&ops_list, NULL, net_exit_list, false, hold_rtnl);
+	ops_undo_list(&ops_list, NULL, net_exit_list, false);
 	list_del(&ops->list);
 }
 
@@ -452,7 +454,7 @@ static __net_init int setup_net(struct net *net)
 	 * for the pernet modules whose init functions did not fail.
 	 */
 	list_add(&net->exit_list, &net_exit_list);
-	ops_undo_list(&pernet_list, ops, &net_exit_list, false, true);
+	ops_undo_list(&pernet_list, ops, &net_exit_list, false);
 	rcu_barrier();
 	goto out;
 }
@@ -681,7 +683,7 @@ static void cleanup_net(struct work_struct *work)
 		list_add_tail(&net->exit_list, &net_exit_list);
 	}
 
-	ops_undo_list(&pernet_list, NULL, &net_exit_list, true, true);
+	ops_undo_list(&pernet_list, NULL, &net_exit_list, true);
 
 	up_read(&pernet_ops_rwsem);