From: Cong Wang <xiyou.wangcong@gmail.com>
Date: Thu, 26 Oct 2017 18:24:37 -0700
Subject: net_sched: use tcf_queue_work() in route filter
Patch-mainline: v4.14-rc7
Git-commit: c2f3f31d402be4849b06282c3a5278f2865c9fcc
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_route.c | 19 ++++++++++++++++---
1 file changed, 16 insertions(+), 3 deletions(-)
--- a/net/sched/cls_route.c
+++ b/net/sched/cls_route.c
@@ -57,7 +57,10 @@ struct route4_filter {
u32 handle;
struct route4_bucket *bkt;
struct tcf_proto *tp;
- struct rcu_head rcu;
+ union {
+ struct work_struct work;
+ struct rcu_head rcu;
+ };
};
#define ROUTE4_FAILURE ((struct route4_filter *)(-1L))
@@ -254,12 +257,22 @@ static int route4_init(struct tcf_proto
return 0;
}
-static void route4_delete_filter(struct rcu_head *head)
+static void route4_delete_filter_work(struct work_struct *work)
{
- struct route4_filter *f = container_of(head, struct route4_filter, rcu);
+ struct route4_filter *f = container_of(work, struct route4_filter, work);
+ rtnl_lock();
tcf_exts_destroy(&f->exts);
kfree(f);
+ rtnl_unlock();
+}
+
+static void route4_delete_filter(struct rcu_head *head)
+{
+ struct route4_filter *f = container_of(head, struct route4_filter, rcu);
+
+ INIT_WORK(&f->work, route4_delete_filter_work);
+ tcf_queue_work(&f->work);
}
static void route4_destroy(struct tcf_proto *tp)