From: Cong Wang <xiyou.wangcong@gmail.com>
Date: Thu, 26 Oct 2017 18:24:35 -0700
Subject: net_sched: use tcf_queue_work() in matchall filter
Patch-mainline: v4.14-rc7
Git-commit: df2735ee8e6ca202a8630f237b59401a25193be1
References: bsc#1109837
Defer the tcf_exts_destroy() in RCU callback to
tc filter workqueue and get RTNL lock.
Reported-by: Chris Mi <chrism@mellanox.com>
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" <paulmck@linux.vnet.ibm.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
net/sched/cls_matchall.c | 19 ++++++++++++++++---
1 file changed, 16 insertions(+), 3 deletions(-)
--- a/net/sched/cls_matchall.c
+++ b/net/sched/cls_matchall.c
@@ -21,7 +21,10 @@ struct cls_mall_head {
struct tcf_result res;
u32 handle;
u32 flags;
- struct rcu_head rcu;
+ union {
+ struct work_struct work;
+ struct rcu_head rcu;
+ };
};
static int mall_classify(struct sk_buff *skb, const struct tcf_proto *tp,
@@ -41,13 +44,23 @@ static int mall_init(struct tcf_proto *t
return 0;
}
+static void mall_destroy_work(struct work_struct *work)
+{
+ struct cls_mall_head *head = container_of(work, struct cls_mall_head,
+ work);
+ rtnl_lock();
+ tcf_exts_destroy(&head->exts);
+ kfree(head);
+ rtnl_unlock();
+}
+
static void mall_destroy_rcu(struct rcu_head *rcu)
{
struct cls_mall_head *head = container_of(rcu, struct cls_mall_head,
rcu);
- tcf_exts_destroy(&head->exts);
- kfree(head);
+ INIT_WORK(&head->work, mall_destroy_work);
+ tcf_queue_work(&head->work);
}
static int mall_replace_hw_filter(struct tcf_proto *tp,