net_sched: switch to rcu_work

Commit 05f0fe6 ("RCU, workqueue: Implement rcu_work") introduces
new API's for dispatching work in a RCU callback. Now we can just
switch to the new API's for tc filters. This could get rid of a lot
of code.

Cc: Tejun Heo <[email protected]>
Cc: "Paul E. McKenney" <[email protected]>
Cc: Jamal Hadi Salim <[email protected]>
Signed-off-by: Cong Wang <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

Author: congwang

include/net/pkt_cls.h

@@ -33,7 +33,7 @@ struct tcf_block_ext_info {
 };
 
 struct tcf_block_cb;
-bool tcf_queue_work(struct work_struct *work);
+bool tcf_queue_work(struct rcu_work *rwork, work_func_t func);
 
 #ifdef CONFIG_NET_CLS
 struct tcf_chain *tcf_chain_get(struct tcf_block *block, u32 chain_index,

net/sched/cls_api.c

@@ -103,9 +103,10 @@ int unregister_tcf_proto_ops(struct tcf_proto_ops *ops)
 }
 EXPORT_SYMBOL(unregister_tcf_proto_ops);
 
-bool tcf_queue_work(struct work_struct *work)
+bool tcf_queue_work(struct rcu_work *rwork, work_func_t func)
 {
-	return queue_work(tc_filter_wq, work);
+	INIT_RCU_WORK(rwork, func);
+	return queue_rcu_work(tc_filter_wq, rwork);
 }
 EXPORT_SYMBOL(tcf_queue_work);
 

net/sched/cls_basic.c

@@ -35,10 +35,7 @@ struct basic_filter {
 	struct tcf_result	res;
 	struct tcf_proto	*tp;
 	struct list_head	link;
-	union {
-		struct work_struct	work;
-		struct rcu_head		rcu;
-	};
+	struct rcu_work		rwork;
 };
 
 static int basic_classify(struct sk_buff *skb, const struct tcf_proto *tp,
@@ -97,21 +94,14 @@ static void __basic_delete_filter(struct basic_filter *f)
 
 static void basic_delete_filter_work(struct work_struct *work)
 {
-	struct basic_filter *f = container_of(work, struct basic_filter, work);
-
+	struct basic_filter *f = container_of(to_rcu_work(work),
+					      struct basic_filter,
+					      rwork);
 	rtnl_lock();
 	__basic_delete_filter(f);
 	rtnl_unlock();
 }
 
-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 netlink_ext_ack *extack)
 {
 	struct basic_head *head = rtnl_dereference(tp->root);
@@ -122,7 +112,7 @@ static void basic_destroy(struct tcf_proto *tp, struct netlink_ext_ack *extack)
 		tcf_unbind_filter(tp, &f->res);
 		idr_remove(&head->handle_idr, f->handle);
 		if (tcf_exts_get_net(&f->exts))
-			call_rcu(&f->rcu, basic_delete_filter);
+			tcf_queue_work(&f->rwork, basic_delete_filter_work);
 		else
 			__basic_delete_filter(f);
 	}
@@ -140,7 +130,7 @@ static int basic_delete(struct tcf_proto *tp, void *arg, bool *last,
 	tcf_unbind_filter(tp, &f->res);
 	idr_remove(&head->handle_idr, f->handle);
 	tcf_exts_get_net(&f->exts);
-	call_rcu(&f->rcu, basic_delete_filter);
+	tcf_queue_work(&f->rwork, basic_delete_filter_work);
 	*last = list_empty(&head->flist);
 	return 0;
 }
@@ -234,7 +224,7 @@ static int basic_change(struct net *net, struct sk_buff *in_skb,
 		list_replace_rcu(&fold->link, &fnew->link);
 		tcf_unbind_filter(tp, &fold->res);
 		tcf_exts_get_net(&fold->exts);
-		call_rcu(&fold->rcu, basic_delete_filter);
+		tcf_queue_work(&fold->rwork, basic_delete_filter_work);
 	} else {
 		list_add_rcu(&fnew->link, &head->flist);
 	}

net/sched/cls_bpf.c

@@ -49,10 +49,7 @@ struct cls_bpf_prog {
 	struct sock_filter *bpf_ops;
 	const char *bpf_name;
 	struct tcf_proto *tp;
-	union {
-		struct work_struct work;
-		struct rcu_head rcu;
-	};
+	struct rcu_work rwork;
 };
 
 static const struct nla_policy bpf_policy[TCA_BPF_MAX + 1] = {
@@ -275,21 +272,14 @@ static void __cls_bpf_delete_prog(struct cls_bpf_prog *prog)
 
 static void cls_bpf_delete_prog_work(struct work_struct *work)
 {
-	struct cls_bpf_prog *prog = container_of(work, struct cls_bpf_prog, work);
-
+	struct cls_bpf_prog *prog = container_of(to_rcu_work(work),
+						 struct cls_bpf_prog,
+						 rwork);
 	rtnl_lock();
 	__cls_bpf_delete_prog(prog);
 	rtnl_unlock();
 }
 
-static void cls_bpf_delete_prog_rcu(struct rcu_head *rcu)
-{
-	struct cls_bpf_prog *prog = container_of(rcu, struct cls_bpf_prog, rcu);
-
-	INIT_WORK(&prog->work, cls_bpf_delete_prog_work);
-	tcf_queue_work(&prog->work);
-}
-
 static void __cls_bpf_delete(struct tcf_proto *tp, struct cls_bpf_prog *prog,
 			     struct netlink_ext_ack *extack)
 {
@@ -300,7 +290,7 @@ static void __cls_bpf_delete(struct tcf_proto *tp, struct cls_bpf_prog *prog,
 	list_del_rcu(&prog->link);
 	tcf_unbind_filter(tp, &prog->res);
 	if (tcf_exts_get_net(&prog->exts))
-		call_rcu(&prog->rcu, cls_bpf_delete_prog_rcu);
+		tcf_queue_work(&prog->rwork, cls_bpf_delete_prog_work);
 	else
 		__cls_bpf_delete_prog(prog);
 }
@@ -526,7 +516,7 @@ static int cls_bpf_change(struct net *net, struct sk_buff *in_skb,
 		list_replace_rcu(&oldprog->link, &prog->link);
 		tcf_unbind_filter(tp, &oldprog->res);
 		tcf_exts_get_net(&oldprog->exts);
-		call_rcu(&oldprog->rcu, cls_bpf_delete_prog_rcu);
+		tcf_queue_work(&oldprog->rwork, cls_bpf_delete_prog_work);
 	} else {
 		list_add_rcu(&prog->link, &head->plist);
 	}

net/sched/cls_cgroup.c

@@ -23,10 +23,7 @@ struct cls_cgroup_head {
 	struct tcf_exts		exts;
 	struct tcf_ematch_tree	ematches;
 	struct tcf_proto	*tp;
-	union {
-		struct work_struct	work;
-		struct rcu_head		rcu;
-	};
+	struct rcu_work		rwork;
 };
 
 static int cls_cgroup_classify(struct sk_buff *skb, const struct tcf_proto *tp,
@@ -70,24 +67,14 @@ static void __cls_cgroup_destroy(struct cls_cgroup_head *head)
 
 static void cls_cgroup_destroy_work(struct work_struct *work)
 {
-	struct cls_cgroup_head *head = container_of(work,
+	struct cls_cgroup_head *head = container_of(to_rcu_work(work),
 						    struct cls_cgroup_head,
-						    work);
+						    rwork);
 	rtnl_lock();
 	__cls_cgroup_destroy(head);
 	rtnl_unlock();
 }
 
-static void cls_cgroup_destroy_rcu(struct rcu_head *root)
-{
-	struct cls_cgroup_head *head = container_of(root,
-						    struct cls_cgroup_head,
-						    rcu);
-
-	INIT_WORK(&head->work, cls_cgroup_destroy_work);
-	tcf_queue_work(&head->work);
-}
-
 static int cls_cgroup_change(struct net *net, struct sk_buff *in_skb,
 			     struct tcf_proto *tp, unsigned long base,
 			     u32 handle, struct nlattr **tca,
@@ -134,7 +121,7 @@ static int cls_cgroup_change(struct net *net, struct sk_buff *in_skb,
 	rcu_assign_pointer(tp->root, new);
 	if (head) {
 		tcf_exts_get_net(&head->exts);
-		call_rcu(&head->rcu, cls_cgroup_destroy_rcu);
+		tcf_queue_work(&head->rwork, cls_cgroup_destroy_work);
 	}
 	return 0;
 errout:
@@ -151,7 +138,7 @@ static void cls_cgroup_destroy(struct tcf_proto *tp,
 	/* Head can still be NULL due to cls_cgroup_init(). */
 	if (head) {
 		if (tcf_exts_get_net(&head->exts))
-			call_rcu(&head->rcu, cls_cgroup_destroy_rcu);
+			tcf_queue_work(&head->rwork, cls_cgroup_destroy_work);
 		else
 			__cls_cgroup_destroy(head);
 	}

net/sched/cls_flow.c

@@ -57,10 +57,7 @@ struct flow_filter {
 	u32			divisor;
 	u32			baseclass;
 	u32			hashrnd;
-	union {
-		struct work_struct	work;
-		struct rcu_head		rcu;
-	};
+	struct rcu_work		rwork;
 };
 
 static inline u32 addr_fold(void *addr)
@@ -383,21 +380,14 @@ static void __flow_destroy_filter(struct flow_filter *f)
 
 static void flow_destroy_filter_work(struct work_struct *work)
 {
-	struct flow_filter *f = container_of(work, struct flow_filter, work);
-
+	struct flow_filter *f = container_of(to_rcu_work(work),
+					     struct flow_filter,
+					     rwork);
 	rtnl_lock();
 	__flow_destroy_filter(f);
 	rtnl_unlock();
 }
 
-static void flow_destroy_filter(struct rcu_head *head)
-{
-	struct flow_filter *f = container_of(head, struct flow_filter, rcu);
-
-	INIT_WORK(&f->work, flow_destroy_filter_work);
-	tcf_queue_work(&f->work);
-}
-
 static int flow_change(struct net *net, struct sk_buff *in_skb,
 		       struct tcf_proto *tp, unsigned long base,
 		       u32 handle, struct nlattr **tca,
@@ -563,7 +553,7 @@ static int flow_change(struct net *net, struct sk_buff *in_skb,
 
 	if (fold) {
 		tcf_exts_get_net(&fold->exts);
-		call_rcu(&fold->rcu, flow_destroy_filter);
+		tcf_queue_work(&fold->rwork, flow_destroy_filter_work);
 	}
 	return 0;
 
@@ -583,7 +573,7 @@ static int flow_delete(struct tcf_proto *tp, void *arg, bool *last,
 
 	list_del_rcu(&f->list);
 	tcf_exts_get_net(&f->exts);
-	call_rcu(&f->rcu, flow_destroy_filter);
+	tcf_queue_work(&f->rwork, flow_destroy_filter_work);
 	*last = list_empty(&head->filters);
 	return 0;
 }
@@ -608,7 +598,7 @@ static void flow_destroy(struct tcf_proto *tp, struct netlink_ext_ack *extack)
 	list_for_each_entry_safe(f, next, &head->filters, list) {
 		list_del_rcu(&f->list);
 		if (tcf_exts_get_net(&f->exts))
-			call_rcu(&f->rcu, flow_destroy_filter);
+			tcf_queue_work(&f->rwork, flow_destroy_filter_work);
 		else
 			__flow_destroy_filter(f);
 	}

net/sched/cls_flower.c

@@ -73,10 +73,7 @@ struct fl_flow_mask {
 struct cls_fl_head {
 	struct rhashtable ht;
 	struct list_head masks;
-	union {
-		struct work_struct work;
-		struct rcu_head	rcu;
-	};
+	struct rcu_work rwork;
 	struct idr handle_idr;
 };
 
@@ -90,10 +87,7 @@ struct cls_fl_filter {
 	struct list_head list;
 	u32 handle;
 	u32 flags;
-	union {
-		struct work_struct work;
-		struct rcu_head	rcu;
-	};
+	struct rcu_work rwork;
 	struct net_device *hw_dev;
 };
 
@@ -235,21 +229,14 @@ static void __fl_destroy_filter(struct cls_fl_filter *f)
 
 static void fl_destroy_filter_work(struct work_struct *work)
 {
-	struct cls_fl_filter *f = container_of(work, struct cls_fl_filter, work);
+	struct cls_fl_filter *f = container_of(to_rcu_work(work),
+					struct cls_fl_filter, rwork);
 
 	rtnl_lock();
 	__fl_destroy_filter(f);
 	rtnl_unlock();
 }
 
-static void fl_destroy_filter(struct rcu_head *head)
-{
-	struct cls_fl_filter *f = container_of(head, struct cls_fl_filter, rcu);
-
-	INIT_WORK(&f->work, fl_destroy_filter_work);
-	tcf_queue_work(&f->work);
-}
-
 static void fl_hw_destroy_filter(struct tcf_proto *tp, struct cls_fl_filter *f,
 				 struct netlink_ext_ack *extack)
 {
@@ -327,7 +314,7 @@ static bool __fl_delete(struct tcf_proto *tp, struct cls_fl_filter *f,
 		fl_hw_destroy_filter(tp, f, extack);
 	tcf_unbind_filter(tp, &f->res);
 	if (async)
-		call_rcu(&f->rcu, fl_destroy_filter);
+		tcf_queue_work(&f->rwork, fl_destroy_filter_work);
 	else
 		__fl_destroy_filter(f);
 
@@ -336,20 +323,13 @@ static bool __fl_delete(struct tcf_proto *tp, struct cls_fl_filter *f,
 
 static void fl_destroy_sleepable(struct work_struct *work)
 {
-	struct cls_fl_head *head = container_of(work, struct cls_fl_head,
-						work);
+	struct cls_fl_head *head = container_of(to_rcu_work(work),
+						struct cls_fl_head,
+						rwork);
 	kfree(head);
 	module_put(THIS_MODULE);
 }
 
-static void fl_destroy_rcu(struct rcu_head *rcu)
-{
-	struct cls_fl_head *head = container_of(rcu, struct cls_fl_head, rcu);
-
-	INIT_WORK(&head->work, fl_destroy_sleepable);
-	schedule_work(&head->work);
-}
-
 static void fl_destroy(struct tcf_proto *tp, struct netlink_ext_ack *extack)
 {
 	struct cls_fl_head *head = rtnl_dereference(tp->root);
@@ -365,7 +345,7 @@ static void fl_destroy(struct tcf_proto *tp, struct netlink_ext_ack *extack)
 	idr_destroy(&head->handle_idr);
 
 	__module_get(THIS_MODULE);
-	call_rcu(&head->rcu, fl_destroy_rcu);
+	tcf_queue_work(&head->rwork, fl_destroy_sleepable);
 }
 
 static void *fl_get(struct tcf_proto *tp, u32 handle)
@@ -1036,7 +1016,7 @@ static int fl_change(struct net *net, struct sk_buff *in_skb,
 		list_replace_rcu(&fold->list, &fnew->list);
 		tcf_unbind_filter(tp, &fold->res);
 		tcf_exts_get_net(&fold->exts);
-		call_rcu(&fold->rcu, fl_destroy_filter);
+		tcf_queue_work(&fold->rwork, fl_destroy_filter_work);
 	} else {
 		list_add_tail_rcu(&fnew->list, &fnew->mask->filters);
 	}