[Patch net 05/16] net_sched: use tcf_queue_work() in flow filter
From: Cong Wang <hidden>
Date: 2017-10-27 01:25:04
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_flow.c | 19 ++++++++++++++++--- 1 file changed, 16 insertions(+), 3 deletions(-)
diff --git a/net/sched/cls_flow.c b/net/sched/cls_flow.c
index 2a3a60ec5b86..67f3a2af6aab 100644
--- a/net/sched/cls_flow.c
+++ b/net/sched/cls_flow.c@@ -57,7 +57,10 @@ struct flow_filter { u32 divisor; u32 baseclass; u32 hashrnd; - struct rcu_head rcu; + union { + struct work_struct work; + struct rcu_head rcu; + }; }; static inline u32 addr_fold(void *addr)
@@ -369,14 +372,24 @@ static const struct nla_policy flow_policy[TCA_FLOW_MAX + 1] = { [TCA_FLOW_PERTURB] = { .type = NLA_U32 }, }; -static void flow_destroy_filter(struct rcu_head *head) +static void flow_destroy_filter_work(struct work_struct *work) { - struct flow_filter *f = container_of(head, struct flow_filter, rcu); + struct flow_filter *f = container_of(work, struct flow_filter, work); + rtnl_lock(); del_timer_sync(&f->perturb_timer); tcf_exts_destroy(&f->exts); tcf_em_tree_destroy(&f->ematches); kfree(f); + rtnl_unlock(); +} + +static void flow_destroy_filter(struct rcu_head *head) +{ + struct flow_filter *f = container_of(head, struct flow_filter, rcu); + + INIT_WORK(&f->work, flow_destroy_filter_work); + tcf_queue_work(&f->work); } static int flow_change(struct net *net, struct sk_buff *in_skb,
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2.13.0