From: Cong Wang <xiyou.wangcong@gmail.com>
Date: Thu, 26 Oct 2017 18:24:29 -0700
Subject: net_sched: use tcf_queue_work() in basic filter
Patch-mainline: v4.14-rc7
Git-commit: c96a48385d53089ee9977dd0bce82a9493984484
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_basic.c | 20 +++++++++++++++++---
1 file changed, 17 insertions(+), 3 deletions(-)
--- a/net/sched/cls_basic.c
+++ b/net/sched/cls_basic.c
@@ -34,7 +34,10 @@ struct basic_filter {
struct tcf_result res;
struct tcf_proto *tp;
struct list_head link;
- struct rcu_head rcu;
+ union {
+ struct work_struct work;
+ struct rcu_head rcu;
+ };
};
static int basic_classify(struct sk_buff *skb, const struct tcf_proto *tp,
@@ -82,15 +85,26 @@ static int basic_init(struct tcf_proto *
return 0;
}
-static void basic_delete_filter(struct rcu_head *head)
+static void basic_delete_filter_work(struct work_struct *work)
{
- struct basic_filter *f = container_of(head, struct basic_filter, rcu);
+ struct basic_filter *f = container_of(work, struct basic_filter, work);
+ rtnl_lock();
tcf_exts_destroy(&f->exts);
tcf_em_tree_destroy(&f->ematches);
+ rtnl_unlock();
+
kfree(f);
}
+static void basic_delete_filter(struct rcu_head *head)
+{
+ struct basic_filter *f = container_of(head, struct basic_filter, rcu);
+
+ INIT_WORK(&f->work, basic_delete_filter_work);
+ tcf_queue_work(&f->work);
+}
+
static void basic_destroy(struct tcf_proto *tp)
{
struct basic_head *head = rtnl_dereference(tp->root);