[RFC PATCH 15/15] l2tp: use pre_exit pernet hook to avoid rcu_barrier
From: James Chapman <jchapman@katalix.com>
Date: 2024-07-23 13:51:55
Subsystem:
networking [general], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
Move the work of closing all tunnels from the pernet exit hook to pre_exit since the core does rcu synchronisation between these steps and we can therefore remove rcu_barrier from l2tp code. --- net/l2tp/l2tp_core.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c
index fd03c17dd20c..5d2068b6c778 100644
--- a/net/l2tp/l2tp_core.c
+++ b/net/l2tp/l2tp_core.c@@ -1756,7 +1756,7 @@ static __net_init int l2tp_init_net(struct net *net) return 0; } -static __net_exit void l2tp_exit_net(struct net *net) +static __net_exit void l2tp_pre_exit_net(struct net *net) { struct l2tp_net *pn = l2tp_pernet(net); struct l2tp_tunnel *tunnel = NULL;
@@ -1771,7 +1771,11 @@ static __net_exit void l2tp_exit_net(struct net *net) if (l2tp_wq) drain_workqueue(l2tp_wq); - rcu_barrier(); +} + +static __net_exit void l2tp_exit_net(struct net *net) +{ + struct l2tp_net *pn = l2tp_pernet(net); idr_destroy(&pn->l2tp_v2_session_idr); idr_destroy(&pn->l2tp_v3_session_idr);
@@ -1781,6 +1785,7 @@ static __net_exit void l2tp_exit_net(struct net *net) static struct pernet_operations l2tp_net_ops = { .init = l2tp_init_net, .exit = l2tp_exit_net, + .pre_exit = l2tp_pre_exit_net, .id = &l2tp_net_id, .size = sizeof(struct l2tp_net), };
--
2.34.1