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Commit bdf5bd7f authored by Sowmini Varadhan's avatar Sowmini Varadhan Committed by David S. Miller
Browse files

rds: tcp: remove register_netdevice_notifier infrastructure. 



The netns deletion path does not need to wait for all net_devices
to be unregistered before dismantling rds_tcp state for the netns
(we are able to dismantle this state on module unload even when
all net_devices are active so there is no dependency here).

This patch removes code related to netdevice notifiers and
refactors all the code needed to dismantle rds_tcp state
into a ->exit callback for the pernet_operations used with
register_pernet_device().

Signed-off-by: default avatarSowmini Varadhan <sowmini.varadhan@oracle.com>
Reviewed-by: default avatarKirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 692ec06d

net/rds/tcp.c

+23 −70
Original line number Diff line number Diff line
@@ -485,40 +485,6 @@ static __net_init int rds_tcp_init_net(struct net *net) 
	return err;

}



static void __net_exit rds_tcp_exit_net(struct net *net)

{

	struct rds_tcp_net *rtn = net_generic(net, rds_tcp_netid);



	if (rtn->rds_tcp_sysctl)

		unregister_net_sysctl_table(rtn->rds_tcp_sysctl);



	if (net != &init_net && rtn->ctl_table)

		kfree(rtn->ctl_table);



	/* If rds_tcp_exit_net() is called as a result of netns deletion,

	 * the rds_tcp_kill_sock() device notifier would already have cleaned

	 * up the listen socket, thus there is no work to do in this function.

	 *

	 * If rds_tcp_exit_net() is called as a result of module unload,

	 * i.e., due to rds_tcp_exit() -> unregister_pernet_subsys(), then

	 * we do need to clean up the listen socket here.

	 */

	if (rtn->rds_tcp_listen_sock) {

		struct socket *lsock = rtn->rds_tcp_listen_sock;



		rtn->rds_tcp_listen_sock = NULL;

		rds_tcp_listen_stop(lsock, &rtn->rds_tcp_accept_w);

	}

}



static struct pernet_operations rds_tcp_net_ops = {

	.init = rds_tcp_init_net,

	.exit = rds_tcp_exit_net,

	.id = &rds_tcp_netid,

	.size = sizeof(struct rds_tcp_net),

	.async = true,

};



static void rds_tcp_kill_sock(struct net *net)

{

	struct rds_tcp_connection *tc, *_tc;
@@ -546,40 +512,38 @@ static void rds_tcp_kill_sock(struct net *net) 
		rds_conn_destroy(tc->t_cpath->cp_conn);

}



void *rds_tcp_listen_sock_def_readable(struct net *net)

static void __net_exit rds_tcp_exit_net(struct net *net)

{

	struct rds_tcp_net *rtn = net_generic(net, rds_tcp_netid);

	struct socket *lsock = rtn->rds_tcp_listen_sock;



	if (!lsock)

		return NULL;

	rds_tcp_kill_sock(net);



	return lsock->sk->sk_user_data;

	if (rtn->rds_tcp_sysctl)

		unregister_net_sysctl_table(rtn->rds_tcp_sysctl);



	if (net != &init_net && rtn->ctl_table)

		kfree(rtn->ctl_table);

}



static int rds_tcp_dev_event(struct notifier_block *this,

			     unsigned long event, void *ptr)

static struct pernet_operations rds_tcp_net_ops = {

	.init = rds_tcp_init_net,

	.exit = rds_tcp_exit_net,

	.id = &rds_tcp_netid,

	.size = sizeof(struct rds_tcp_net),

	.async = true,

};



void *rds_tcp_listen_sock_def_readable(struct net *net)

{

	struct net_device *dev = netdev_notifier_info_to_dev(ptr);

	struct rds_tcp_net *rtn = net_generic(net, rds_tcp_netid);

	struct socket *lsock = rtn->rds_tcp_listen_sock;



	/* rds-tcp registers as a pernet subys, so the ->exit will only

	 * get invoked after network acitivity has quiesced. We need to

	 * clean up all sockets  to quiesce network activity, and use

	 * the unregistration of the per-net loopback device as a trigger

	 * to start that cleanup.

	 */

	if (event == NETDEV_UNREGISTER_FINAL &&

	    dev->ifindex == LOOPBACK_IFINDEX)

		rds_tcp_kill_sock(dev_net(dev));

	if (!lsock)

		return NULL;



	return NOTIFY_DONE;

	return lsock->sk->sk_user_data;

}



static struct notifier_block rds_tcp_dev_notifier = {

	.notifier_call        = rds_tcp_dev_event,

	.priority = -10, /* must be called after other network notifiers */

};



/* when sysctl is used to modify some kernel socket parameters,this

 * function  resets the RDS connections in that netns  so that we can

 * restart with new parameters.  The assumption is that such reset
@@ -625,9 +589,7 @@ static void rds_tcp_exit(void) 
	rds_tcp_set_unloading();

	synchronize_rcu();

	rds_info_deregister_func(RDS_INFO_TCP_SOCKETS, rds_tcp_tc_info);

	unregister_pernet_subsys(&rds_tcp_net_ops);

	if (unregister_netdevice_notifier(&rds_tcp_dev_notifier))

		pr_warn("could not unregister rds_tcp_dev_notifier\n");

	unregister_pernet_device(&rds_tcp_net_ops);

	rds_tcp_destroy_conns();

	rds_trans_unregister(&rds_tcp_transport);

	rds_tcp_recv_exit();
@@ -651,24 +613,15 @@ static int rds_tcp_init(void) 
	if (ret)

		goto out_slab;



	ret = register_pernet_subsys(&rds_tcp_net_ops);

	ret = register_pernet_device(&rds_tcp_net_ops);

	if (ret)

		goto out_recv;



	ret = register_netdevice_notifier(&rds_tcp_dev_notifier);

	if (ret) {

		pr_warn("could not register rds_tcp_dev_notifier\n");

		goto out_pernet;

	}



	rds_trans_register(&rds_tcp_transport);



	rds_info_register_func(RDS_INFO_TCP_SOCKETS, rds_tcp_tc_info);



	goto out;



out_pernet:

	unregister_pernet_subsys(&rds_tcp_net_ops);

out_recv:

	rds_tcp_recv_exit();

out_slab: