From e071dff2a6beeccb6f9744f9a0251ab773ca2ab8 Mon Sep 17 00:00:00 2001
From: Cong Wang <xiyou.wangcong@gmail.com>
Date: Thu, 26 Oct 2017 18:24:34 -0700
Subject: [PATCH] net_sched: use tcf_queue_work() in fw filter
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>
---
net/sched/cls_fw.c | 19 ++++++++++++++++---
1 file changed, 16 insertions(+), 3 deletions(-)
diff --git a/net/sched/cls_fw.c b/net/sched/cls_fw.c
index 941245ad07fd4..99183b8621ecb 100644
--- a/net/sched/cls_fw.c
+++ b/net/sched/cls_fw.c
@@ -46,7 +46,10 @@ struct fw_filter {
#endif /* CONFIG_NET_CLS_IND */
struct tcf_exts exts;
struct tcf_proto *tp;
- struct rcu_head rcu;
+ union {
+ struct work_struct work;
+ struct rcu_head rcu;
+ };
};
static u32 fw_hash(u32 handle)
@@ -119,12 +122,22 @@ static int fw_init(struct tcf_proto *tp)
return 0;
}
-static void fw_delete_filter(struct rcu_head *head)
+static void fw_delete_filter_work(struct work_struct *work)
{
- struct fw_filter *f = container_of(head, struct fw_filter, rcu);
+ struct fw_filter *f = container_of(work, struct fw_filter, work);
+ rtnl_lock();
tcf_exts_destroy(&f->exts);
kfree(f);
+ rtnl_unlock();
+}
+
+static void fw_delete_filter(struct rcu_head *head)
+{
+ struct fw_filter *f = container_of(head, struct fw_filter, rcu);
+
+ INIT_WORK(&f->work, fw_delete_filter_work);
+ tcf_queue_work(&f->work);
}
static void fw_destroy(struct tcf_proto *tp)
--
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