netns: Add an explicit rcu_barrier to unregister_pernet_{device|subsys}
This allows namespace exit methods to batch work that comes requires an
rcu barrier using call_rcu without having to treat the
unregister_pernet_operations cases specially.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
index 4026a4cf..bd8c471 100644
--- a/net/core/net_namespace.c
+++ b/net/core/net_namespace.c
@@ -413,8 +413,11 @@
}
}
error = __register_pernet_operations(list, ops);
- if (error && ops->id)
- ida_remove(&net_generic_ids, *ops->id);
+ if (error) {
+ rcu_barrier();
+ if (ops->id)
+ ida_remove(&net_generic_ids, *ops->id);
+ }
return error;
}
@@ -423,6 +426,7 @@
{
__unregister_pernet_operations(ops);
+ rcu_barrier();
if (ops->id)
ida_remove(&net_generic_ids, *ops->id);
}