ipmr: Convert ipmr_net_exit_batch() to ->exit_rtnl().

ipmr_net_ops uses ->exit_batch() to acquire RTNL only once
for dying network namespaces.

ipmr does not depend on the ordering of ->exit_rtnl() and
->exit_batch() of other pernet_operations (unlike fib_net_ops).

Once ipmr_free_table() is called and all devices are
queued for destruction in ->exit_rtnl(), later during
NETDEV_UNREGISTER, ipmr_device_event() will not see anything
in vif table and just do nothing.

Let's convert ipmr_net_exit_batch() to ->exit_rtnl().

Note that fib_rules_unregister() does not need RTNL and
we will remove RTNL and unregister_netdevice_many() in
ipmr_net_init().

Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260228221800.1082070-10-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Kuniyuki Iwashima 2026-02-28 22:17:27 +00:00 committed by Jakub Kicinski
parent b7fdc3cfb6
commit b22b018674

View File

@ -285,18 +285,17 @@ static int __net_init ipmr_rules_init(struct net *net)
return err; return err;
} }
static void __net_exit ipmr_rules_exit(struct net *net) static void __net_exit ipmr_rules_exit_rtnl(struct net *net,
struct list_head *dev_kill_list)
{ {
struct mr_table *mrt, *next; struct mr_table *mrt, *next;
LIST_HEAD(dev_kill_list);
ASSERT_RTNL(); ASSERT_RTNL();
list_for_each_entry_safe(mrt, next, &net->ipv4.mr_tables, list) { list_for_each_entry_safe(mrt, next, &net->ipv4.mr_tables, list) {
list_del(&mrt->list); list_del(&mrt->list);
ipmr_free_table(mrt, &dev_kill_list); ipmr_free_table(mrt, dev_kill_list);
} }
unregister_netdevice_many(&dev_kill_list);
fib_rules_unregister(net->ipv4.mr_rules_ops); fib_rules_unregister(net->ipv4.mr_rules_ops);
} }
@ -353,14 +352,12 @@ static int __net_init ipmr_rules_init(struct net *net)
return 0; return 0;
} }
static void __net_exit ipmr_rules_exit(struct net *net) static void __net_exit ipmr_rules_exit_rtnl(struct net *net,
struct list_head *dev_kill_list)
{ {
LIST_HEAD(dev_kill_list);
ASSERT_RTNL(); ASSERT_RTNL();
ipmr_free_table(net->ipv4.mrt, &dev_kill_list); ipmr_free_table(net->ipv4.mrt, dev_kill_list);
unregister_netdevice_many(&dev_kill_list);
net->ipv4.mrt = NULL; net->ipv4.mrt = NULL;
} }
@ -3264,6 +3261,7 @@ static void __net_exit ipmr_notifier_exit(struct net *net)
/* Setup for IP multicast routing */ /* Setup for IP multicast routing */
static int __net_init ipmr_net_init(struct net *net) static int __net_init ipmr_net_init(struct net *net)
{ {
LIST_HEAD(dev_kill_list);
int err; int err;
err = ipmr_notifier_init(net); err = ipmr_notifier_init(net);
@ -3290,7 +3288,8 @@ static int __net_init ipmr_net_init(struct net *net)
remove_proc_entry("ip_mr_vif", net->proc_net); remove_proc_entry("ip_mr_vif", net->proc_net);
proc_vif_fail: proc_vif_fail:
rtnl_lock(); rtnl_lock();
ipmr_rules_exit(net); ipmr_rules_exit_rtnl(net, &dev_kill_list);
unregister_netdevice_many(&dev_kill_list);
rtnl_unlock(); rtnl_unlock();
#endif #endif
ipmr_rules_fail: ipmr_rules_fail:
@ -3308,20 +3307,16 @@ static void __net_exit ipmr_net_exit(struct net *net)
ipmr_notifier_exit(net); ipmr_notifier_exit(net);
} }
static void __net_exit ipmr_net_exit_batch(struct list_head *net_list) static void __net_exit ipmr_net_exit_rtnl(struct net *net,
struct list_head *dev_kill_list)
{ {
struct net *net; ipmr_rules_exit_rtnl(net, dev_kill_list);
rtnl_lock();
list_for_each_entry(net, net_list, exit_list)
ipmr_rules_exit(net);
rtnl_unlock();
} }
static struct pernet_operations ipmr_net_ops = { static struct pernet_operations ipmr_net_ops = {
.init = ipmr_net_init, .init = ipmr_net_init,
.exit = ipmr_net_exit, .exit = ipmr_net_exit,
.exit_batch = ipmr_net_exit_batch, .exit_rtnl = ipmr_net_exit_rtnl,
}; };
static const struct rtnl_msg_handler ipmr_rtnl_msg_handlers[] __initconst = { static const struct rtnl_msg_handler ipmr_rtnl_msg_handlers[] __initconst = {