Commit b22b0186 authored by Kuniyuki Iwashima's avatar Kuniyuki Iwashima Committed by Jakub Kicinski
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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: default avatarKuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: default avatarEric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260228221800.1082070-10-kuniyu@google.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent b7fdc3cf

net/ipv4/ipmr.c

+13 −18
Original line number Diff line number Diff line
@@ -285,18 +285,17 @@ static int __net_init ipmr_rules_init(struct net *net) 
	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;

	LIST_HEAD(dev_kill_list);



	ASSERT_RTNL();

	list_for_each_entry_safe(mrt, next, &net->ipv4.mr_tables, 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);

}
@@ -353,14 +352,12 @@ static int __net_init ipmr_rules_init(struct net *net) 
	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();



	ipmr_free_table(net->ipv4.mrt, &dev_kill_list);

	unregister_netdevice_many(&dev_kill_list);

	ipmr_free_table(net->ipv4.mrt, dev_kill_list);



	net->ipv4.mrt = NULL;

}
@@ -3264,6 +3261,7 @@ static void __net_exit ipmr_notifier_exit(struct net *net) 
/* Setup for IP multicast routing */

static int __net_init ipmr_net_init(struct net *net)

{

	LIST_HEAD(dev_kill_list);

	int err;



	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);

proc_vif_fail:

	rtnl_lock();

	ipmr_rules_exit(net);

	ipmr_rules_exit_rtnl(net, &dev_kill_list);

	unregister_netdevice_many(&dev_kill_list);

	rtnl_unlock();

#endif

ipmr_rules_fail:
@@ -3308,20 +3307,16 @@ static void __net_exit ipmr_net_exit(struct net *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;



	rtnl_lock();

	list_for_each_entry(net, net_list, exit_list)

		ipmr_rules_exit(net);

	rtnl_unlock();

	ipmr_rules_exit_rtnl(net, dev_kill_list);

}



static struct pernet_operations ipmr_net_ops = {

	.init = ipmr_net_init,

	.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 = {