From d79d792ef9f99cca463b6619a93e860d1c833a6e Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Thu, 3 Dec 2009 02:29:05 +0000 Subject: [PATCH] net: Allow xfrm_user_net_exit to batch efficiently. xfrm.nlsk is provided by the xfrm_user module and is access via rcu from other parts of the xfrm code. Add xfrm.nlsk_stash a copy of xfrm.nlsk that will never be set to NULL. This allows the synchronize_net and netlink_kernel_release to be deferred until a whole batch of xfrm.nlsk sockets have been set to NULL. Signed-off-by: Eric W. Biederman Signed-off-by: David S. Miller --- include/net/netns/xfrm.h | 1 + net/xfrm/xfrm_user.c | 18 ++++++++++-------- 2 files changed, 11 insertions(+), 8 deletions(-) diff --git a/include/net/netns/xfrm.h b/include/net/netns/xfrm.h index 1ba912749ca..56f8e5585df 100644 --- a/include/net/netns/xfrm.h +++ b/include/net/netns/xfrm.h @@ -43,6 +43,7 @@ struct netns_xfrm { struct work_struct policy_hash_work; struct sock *nlsk; + struct sock *nlsk_stash; u32 sysctl_aevent_etime; u32 sysctl_aevent_rseqth; diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c index fb42d778d27..1ada6186933 100644 --- a/net/xfrm/xfrm_user.c +++ b/net/xfrm/xfrm_user.c @@ -2721,22 +2721,24 @@ static int __net_init xfrm_user_net_init(struct net *net) xfrm_netlink_rcv, NULL, THIS_MODULE); if (nlsk == NULL) return -ENOMEM; + net->xfrm.nlsk_stash = nlsk; /* Don't set to NULL */ rcu_assign_pointer(net->xfrm.nlsk, nlsk); return 0; } -static void __net_exit xfrm_user_net_exit(struct net *net) +static void __net_exit xfrm_user_net_exit(struct list_head *net_exit_list) { - struct sock *nlsk = net->xfrm.nlsk; - - rcu_assign_pointer(net->xfrm.nlsk, NULL); - synchronize_rcu(); - netlink_kernel_release(nlsk); + struct net *net; + list_for_each_entry(net, net_exit_list, exit_list) + rcu_assign_pointer(net->xfrm.nlsk, NULL); + synchronize_net(); + list_for_each_entry(net, net_exit_list, exit_list) + netlink_kernel_release(net->xfrm.nlsk_stash); } static struct pernet_operations xfrm_user_net_ops = { - .init = xfrm_user_net_init, - .exit = xfrm_user_net_exit, + .init = xfrm_user_net_init, + .exit_batch = xfrm_user_net_exit, }; static int __init xfrm_user_init(void) -- 2.20.1