From bdf5bd7f21323493dbe5f2c723dc33f2fbb0241a Mon Sep 17 00:00:00 2001 From: Sowmini Varadhan Date: Mon, 19 Mar 2018 06:52:48 -0700 Subject: [PATCH] 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 Reviewed-by: Kirill Tkhai Signed-off-by: David S. Miller --- net/rds/tcp.c | 93 +++++++++++++-------------------------------------- 1 file changed, 23 insertions(+), 70 deletions(-) diff --git a/net/rds/tcp.c b/net/rds/tcp.c index 08ea9cd5c2f6..4f3a32c38bf5 100644 --- a/net/rds/tcp.c +++ b/net/rds/tcp.c @@ -485,40 +485,6 @@ fail: 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: -- 2.30.2