Merge branch 'net-convert-exit_batch_rtnl-to-exit_rtnl'

Kuniyuki Iwashima says:

====================
net: Convert ->exit_batch_rtnl() to ->exit_rtnl().

While converting nexthop to per-netns RTNL, there are two blockers
to using rtnl_net_dereference(), flush_all_nexthops() and
__unregister_nexthop_notifier(), both of which are called from
->exit_batch_rtnl().

Instead of spreading __rtnl_net_lock() over each ->exit_batch_rtnl(),
we should convert all ->exit_batch_rtnl() to per-net ->exit_rtnl() and
run it under __rtnl_net_lock() because all ->exit_batch_rtnl() functions
do not have anything to factor out for batching.

Patch 1 & 2 factorise the undo mechanism against ->init() into a single
function, and Patch 3 adds ->exit_batch_rtnl().

Patch 4 ~ 13 convert all ->exit_batch_rtnl() users.

Patch 14 removes ->exit_batch_rtnl().

Later, we can convert pfcp and ppp to use ->exit_rtnl().

v1: https://lore.kernel.org/all/20250410022004.8668-1-kuniyu@amazon.com/
====================

Link: https://patch.msgid.link/20250411205258.63164-1-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 7 insertions, 20 deletions

diff --git a/net/ipv6/ip6_vti.c b/net/ipv6/ip6_vti.c
index 09ec4b0ad7dc..40464a88bca6 100644
--- a/net/ipv6/ip6_vti.c
+++ b/net/ipv6/ip6_vti.c
@@ -1112,21 +1112,21 @@ static struct rtnl_link_ops vti6_link_ops __read_mostly = {
 	.get_link_net	= ip6_tnl_get_link_net,
 };
 
-static void __net_exit vti6_destroy_tunnels(struct vti6_net *ip6n,
-					    struct list_head *list)
+static void __net_exit vti6_exit_rtnl_net(struct net *net, struct list_head *list)
 {
-	int h;
+	struct vti6_net *ip6n = net_generic(net, vti6_net_id);
 	struct ip6_tnl *t;
+	int h;
 
 	for (h = 0; h < IP6_VTI_HASH_SIZE; h++) {
-		t = rtnl_dereference(ip6n->tnls_r_l[h]);
+		t = rtnl_net_dereference(net, ip6n->tnls_r_l[h]);
 		while (t) {
 			unregister_netdevice_queue(t->dev, list);
-			t = rtnl_dereference(t->next);
+			t = rtnl_net_dereference(net, t->next);
 		}
 	}
 
-	t = rtnl_dereference(ip6n->tnls_wc[0]);
+	t = rtnl_net_dereference(net, ip6n->tnls_wc[0]);
 	if (t)
 		unregister_netdevice_queue(t->dev, list);
 }
@@ -1170,22 +1170,9 @@ err_alloc_dev:
 	return err;
 }
 
-static void __net_exit vti6_exit_batch_rtnl(struct list_head *net_list,
-					    struct list_head *dev_to_kill)
-{
-	struct vti6_net *ip6n;
-	struct net *net;
-
-	ASSERT_RTNL();
-	list_for_each_entry(net, net_list, exit_list) {
-		ip6n = net_generic(net, vti6_net_id);
-		vti6_destroy_tunnels(ip6n, dev_to_kill);
-	}
-}
-
 static struct pernet_operations vti6_net_ops = {
 	.init = vti6_init_net,
-	.exit_batch_rtnl = vti6_exit_batch_rtnl,
+	.exit_rtnl = vti6_exit_rtnl_net,
 	.id   = &vti6_net_id,
 	.size = sizeof(struct vti6_net),
 };