[net,09/16] net_sched: use tcf_queue_work() in u32 filter

Message ID	20171027012443.3306-10-xiyou.wangcong@gmail.com
State	Accepted, archived
Delegated to:	David Miller
Headers	show Return-Path: <netdev-owner@vger.kernel.org> From: Cong Wang <xiyou.wangcong@gmail.com> To: netdev@vger.kernel.org Cc: Chris Mi <chrism@mellanox.com>, Cong Wang <xiyou.wangcong@gmail.com>, Daniel Borkmann <daniel@iogearbox.net>, Jiri Pirko <jiri@resnulli.us>, John Fastabend <john.fastabend@gmail.com>, Jamal Hadi Salim <jhs@mojatatu.com>, "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Subject: [Patch net 09/16] net_sched: use tcf_queue_work() in u32 filter Date: Thu, 26 Oct 2017 18:24:36 -0700 Message-Id: <20171027012443.3306-10-xiyou.wangcong@gmail.com> In-Reply-To: <20171027012443.3306-1-xiyou.wangcong@gmail.com> References: <20171027012443.3306-1-xiyou.wangcong@gmail.com> Sender: netdev-owner@vger.kernel.org Precedence: bulk
Series	net_sched: fix races with RCU callbacks \| expand [net,00/16] net_sched: fix races with RCU callbacks [net,01/16] net_sched: introduce a workqueue for RCU callbacks of tc filter [net,02/16] net_sched: use tcf_queue_work() in basic filter [net,03/16] net_sched: use tcf_queue_work() in bpf filter [net,04/16] net_sched: use tcf_queue_work() in cgroup filter [net,05/16] net_sched: use tcf_queue_work() in flow filter [net,06/16] net_sched: use tcf_queue_work() in flower filter [net,07/16] net_sched: use tcf_queue_work() in fw filter [net,08/16] net_sched: use tcf_queue_work() in matchall filter [net,09/16] net_sched: use tcf_queue_work() in u32 filter [net,10/16] net_sched: use tcf_queue_work() in route filter [net,11/16] net_sched: use tcf_queue_work() in rsvp filter [net,12/16] net_sched: use tcf_queue_work() in tcindex filter [net,13/16] net_sched: add rtnl assertion to tcf_exts_destroy() [net,14/16] net_sched: fix call_rcu() race on act_sample module removal [net,15/16] selftests: Introduce a new script to generate tc batch file [net,16/16] selftests: Introduce a new test case to tc testsuite

Message ID

20171027012443.3306-10-xiyou.wangcong@gmail.com

State

Accepted, archived

Delegated to:

David Miller

Headers

From: Cong Wang <xiyou.wangcong@gmail.com>
To: netdev@vger.kernel.org
Cc: Chris Mi <chrism@mellanox.com>, Cong Wang <xiyou.wangcong@gmail.com>,
	Daniel Borkmann <daniel@iogearbox.net>, Jiri Pirko <jiri@resnulli.us>,
	John Fastabend <john.fastabend@gmail.com>,
	Jamal Hadi Salim <jhs@mojatatu.com>,
	"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Subject: [Patch net 09/16] net_sched: use tcf_queue_work() in u32 filter
Date: Thu, 26 Oct 2017 18:24:36 -0700
Message-Id: <20171027012443.3306-10-xiyou.wangcong@gmail.com>
In-Reply-To: <20171027012443.3306-1-xiyou.wangcong@gmail.com>
References: <20171027012443.3306-1-xiyou.wangcong@gmail.com>
Sender: netdev-owner@vger.kernel.org
Precedence: bulk

Series

net_sched: fix races with RCU callbacks | expand

Commit Message

Cong Wang Oct. 27, 2017, 1:24 a.m. UTC

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>
---
 net/sched/cls_u32.c | 29 ++++++++++++++++++++++++++---
 1 file changed, 26 insertions(+), 3 deletions(-)

diff --git a/net/sched/cls_u32.c b/net/sched/cls_u32.c
index 10b8d851fc6b..dadd1b344497 100644
--- a/net/sched/cls_u32.c
+++ b/net/sched/cls_u32.c
@@ -68,7 +68,10 @@  struct tc_u_knode {
 	u32 __percpu		*pcpu_success;
 #endif
 	struct tcf_proto	*tp;
-	struct rcu_head		rcu;
+	union {
+		struct work_struct	work;
+		struct rcu_head		rcu;
+	};
 	/* The 'sel' field MUST be the last field in structure to allow for
 	 * tc_u32_keys allocated at end of structure.
 	 */
@@ -418,11 +421,21 @@  static int u32_destroy_key(struct tcf_proto *tp, struct tc_u_knode *n,
  * this the u32_delete_key_rcu variant does not free the percpu
  * statistics.
  */
+static void u32_delete_key_work(struct work_struct *work)
+{
+	struct tc_u_knode *key = container_of(work, struct tc_u_knode, work);
+
+	rtnl_lock();
+	u32_destroy_key(key->tp, key, false);
+	rtnl_unlock();
+}
+
 static void u32_delete_key_rcu(struct rcu_head *rcu)
 {
 	struct tc_u_knode *key = container_of(rcu, struct tc_u_knode, rcu);
 
-	u32_destroy_key(key->tp, key, false);
+	INIT_WORK(&key->work, u32_delete_key_work);
+	tcf_queue_work(&key->work);
 }
 
 /* u32_delete_key_freepf_rcu is the rcu callback variant
@@ -432,11 +445,21 @@  static void u32_delete_key_rcu(struct rcu_head *rcu)
  * for the variant that should be used with keys return from
  * u32_init_knode()
  */
+static void u32_delete_key_freepf_work(struct work_struct *work)
+{
+	struct tc_u_knode *key = container_of(work, struct tc_u_knode, work);
+
+	rtnl_lock();
+	u32_destroy_key(key->tp, key, true);
+	rtnl_unlock();
+}
+
 static void u32_delete_key_freepf_rcu(struct rcu_head *rcu)
 {
 	struct tc_u_knode *key = container_of(rcu, struct tc_u_knode, rcu);
 
-	u32_destroy_key(key->tp, key, true);
+	INIT_WORK(&key->work, u32_delete_key_freepf_work);
+	tcf_queue_work(&key->work);
 }
 
 static int u32_delete_key(struct tcf_proto *tp, struct tc_u_knode *key)