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Message-Id: <1521467568-37876-1-git-send-email-sowmini.varadhan@oracle.com>
Date: Mon, 19 Mar 2018 06:52:48 -0700
From: Sowmini Varadhan <sowmini.varadhan@...cle.com>
To: sowmini.varadhan@...cle.com
Cc: davem@...emloft.net, sowmini.varadhan@...cle.com,
santosh.shilimkar@...cle.com, ktkhai@...tuozzo.com
Subject: [PATCH net-next] 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: Sowmini Varadhan <sowmini.varadhan@...cle.com>
---
net/rds/tcp.c | 93 ++++++++++++++-------------------------------------------
1 files changed, 23 insertions(+), 70 deletions(-)
diff --git a/net/rds/tcp.c b/net/rds/tcp.c
index 08ea9cd..4f3a32c 100644
--- a/net/rds/tcp.c
+++ b/net/rds/tcp.c
@@ -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:
--
1.7.1
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