[Patch net 04/16] net_sched: use tcf_queue_work() in cgroup filter
From: Cong Wang <hidden>
Date: 2017-10-27 01:25:03
Subsystem:
networking [general], tc subsystem, the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Jamal Hadi Salim, Jiri Pirko, Linus Torvalds
Defer the tcf_exts_destroy() in RCU callback to tc filter workqueue and get RTNL lock. Reported-by: Chris Mi <redacted> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Jiri Pirko <jiri@resnulli.us> Cc: John Fastabend <john.fastabend@gmail.com> Cc: Jamal Hadi Salim <jhs@mojatatu.com> Cc: "Paul E. McKenney" <redacted> Signed-off-by: Cong Wang <redacted> --- net/sched/cls_cgroup.c | 22 ++++++++++++++++++---- 1 file changed, 18 insertions(+), 4 deletions(-)
diff --git a/net/sched/cls_cgroup.c b/net/sched/cls_cgroup.c
index d48452f87975..a97e069bee89 100644
--- a/net/sched/cls_cgroup.c
+++ b/net/sched/cls_cgroup.c@@ -23,7 +23,10 @@ struct cls_cgroup_head { struct tcf_exts exts; struct tcf_ematch_tree ematches; struct tcf_proto *tp; - struct rcu_head rcu; + union { + struct work_struct work; + struct rcu_head rcu; + }; }; static int cls_cgroup_classify(struct sk_buff *skb, const struct tcf_proto *tp,
@@ -57,15 +60,26 @@ static const struct nla_policy cgroup_policy[TCA_CGROUP_MAX + 1] = { [TCA_CGROUP_EMATCHES] = { .type = NLA_NESTED }, }; +static void cls_cgroup_destroy_work(struct work_struct *work) +{ + struct cls_cgroup_head *head = container_of(work, + struct cls_cgroup_head, + work); + rtnl_lock(); + tcf_exts_destroy(&head->exts); + tcf_em_tree_destroy(&head->ematches); + kfree(head); + rtnl_unlock(); +} + static void cls_cgroup_destroy_rcu(struct rcu_head *root) { struct cls_cgroup_head *head = container_of(root, struct cls_cgroup_head, rcu); - tcf_exts_destroy(&head->exts); - tcf_em_tree_destroy(&head->ematches); - kfree(head); + INIT_WORK(&head->work, cls_cgroup_destroy_work); + tcf_queue_work(&head->work); } static int cls_cgroup_change(struct net *net, struct sk_buff *in_skb,
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2.13.0