8 files changed, 31 insertions, 21 deletions

diff --git a/net/sched/cls_basic.c b/net/sched/cls_basic.c
index eb219b78cd49..5877f6061b57 100644
--- a/net/sched/cls_basic.c
+++ b/net/sched/cls_basic.c
@@ -62,9 +62,6 @@ static unsigned long basic_get(struct tcf_proto *tp, u32 handle)
 	struct basic_head *head = rtnl_dereference(tp->root);
 	struct basic_filter *f;
 
-	if (head == NULL)
-		return 0UL;
-
 	list_for_each_entry(f, &head->flist, link) {
 		if (f->handle == handle) {
 			l = (unsigned long) f;
@@ -109,7 +106,6 @@ static bool basic_destroy(struct tcf_proto *tp, bool force)
 		tcf_unbind_filter(tp, &f->res);
 		call_rcu(&f->rcu, basic_delete_filter);
 	}
-	RCU_INIT_POINTER(tp->root, NULL);
 	kfree_rcu(head, rcu);
 	return true;
 }
diff --git a/net/sched/cls_bpf.c b/net/sched/cls_bpf.c
index bb1d5a487081..0a47ba5e6109 100644
--- a/net/sched/cls_bpf.c
+++ b/net/sched/cls_bpf.c
@@ -292,7 +292,6 @@ static bool cls_bpf_destroy(struct tcf_proto *tp, bool force)
 		call_rcu(&prog->rcu, __cls_bpf_delete_prog);
 	}
 
-	RCU_INIT_POINTER(tp->root, NULL);
 	kfree_rcu(head, rcu);
 	return true;
 }
@@ -303,9 +302,6 @@ static unsigned long cls_bpf_get(struct tcf_proto *tp, u32 handle)
 	struct cls_bpf_prog *prog;
 	unsigned long ret = 0UL;
 
-	if (head == NULL)
-		return 0UL;
-
 	list_for_each_entry(prog, &head->plist, link) {
 		if (prog->handle == handle) {
 			ret = (unsigned long) prog;
diff --git a/net/sched/cls_cgroup.c b/net/sched/cls_cgroup.c
index 85233c470035..c1f20077837f 100644
--- a/net/sched/cls_cgroup.c
+++ b/net/sched/cls_cgroup.c
@@ -137,11 +137,10 @@ static bool cls_cgroup_destroy(struct tcf_proto *tp, bool force)
 
 	if (!force)
 		return false;
-
-	if (head) {
-		RCU_INIT_POINTER(tp->root, NULL);
+	/* Head can still be NULL due to cls_cgroup_init(). */
+	if (head)
 		call_rcu(&head->rcu, cls_cgroup_destroy_rcu);
-	}
+
 	return true;
 }
 
diff --git a/net/sched/cls_flow.c b/net/sched/cls_flow.c
index e39672394c7b..6575aba87630 100644
--- a/net/sched/cls_flow.c
+++ b/net/sched/cls_flow.c
@@ -596,7 +596,6 @@ static bool flow_destroy(struct tcf_proto *tp, bool force)
 		list_del_rcu(&f->list);
 		call_rcu(&f->rcu, flow_destroy_filter);
 	}
-	RCU_INIT_POINTER(tp->root, NULL);
 	kfree_rcu(head, rcu);
 	return true;
 }
diff --git a/net/sched/cls_flower.c b/net/sched/cls_flower.c
index f6f40fba599b..b296f3991ab2 100644
--- a/net/sched/cls_flower.c
+++ b/net/sched/cls_flower.c
@@ -13,6 +13,7 @@
 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/rhashtable.h>
+#include <linux/workqueue.h>
 
 #include <linux/if_ether.h>
 #include <linux/in6.h>
@@ -64,7 +65,10 @@ struct cls_fl_head {
 	bool mask_assigned;
 	struct list_head filters;
 	struct rhashtable_params ht_params;
-	struct rcu_head rcu;
+	union {
+		struct work_struct work;
+		struct rcu_head	rcu;
+	};
 };
 
 struct cls_fl_filter {
@@ -269,6 +273,24 @@ static void fl_hw_update_stats(struct tcf_proto *tp, struct cls_fl_filter *f)
 	dev->netdev_ops->ndo_setup_tc(dev, tp->q->handle, tp->protocol, &tc);
 }
 
+static void fl_destroy_sleepable(struct work_struct *work)
+{
+	struct cls_fl_head *head = container_of(work, struct cls_fl_head,
+						work);
+	if (head->mask_assigned)
+		rhashtable_destroy(&head->ht);
+	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 bool fl_destroy(struct tcf_proto *tp, bool force)
 {
 	struct cls_fl_head *head = rtnl_dereference(tp->root);
@@ -282,10 +304,9 @@ static bool fl_destroy(struct tcf_proto *tp, bool force)
 		list_del_rcu(&f->list);
 		call_rcu(&f->rcu, fl_destroy_filter);
 	}
-	RCU_INIT_POINTER(tp->root, NULL);
-	if (head->mask_assigned)
-		rhashtable_destroy(&head->ht);
-	kfree_rcu(head, rcu);
+
+	__module_get(THIS_MODULE);
+	call_rcu(&head->rcu, fl_destroy_rcu);
 	return true;
 }
 
diff --git a/net/sched/cls_matchall.c b/net/sched/cls_matchall.c
index 25927b6c4436..f935429bd5ef 100644
--- a/net/sched/cls_matchall.c
+++ b/net/sched/cls_matchall.c
@@ -114,7 +114,6 @@ static bool mall_destroy(struct tcf_proto *tp, bool force)
 
 		call_rcu(&f->rcu, mall_destroy_filter);
 	}
-	RCU_INIT_POINTER(tp->root, NULL);
 	kfree_rcu(head, rcu);
 	return true;
 }
diff --git a/net/sched/cls_rsvp.h b/net/sched/cls_rsvp.h
index 4f05a19fb073..322438fb3ffc 100644
--- a/net/sched/cls_rsvp.h
+++ b/net/sched/cls_rsvp.h
@@ -152,7 +152,8 @@ static int rsvp_classify(struct sk_buff *skb, const struct tcf_proto *tp,
 		return -1;
 	nhptr = ip_hdr(skb);
 #endif
-
+	if (unlikely(!head))
+		return -1;
 restart:
 
 #if RSVP_DST_LEN == 4
diff --git a/net/sched/cls_tcindex.c b/net/sched/cls_tcindex.c
index 96144bdf30db..0751245a6ace 100644
--- a/net/sched/cls_tcindex.c
+++ b/net/sched/cls_tcindex.c
@@ -543,7 +543,6 @@ static bool tcindex_destroy(struct tcf_proto *tp, bool force)
 	walker.fn = tcindex_destroy_element;
 	tcindex_walk(tp, &walker);
 
-	RCU_INIT_POINTER(tp->root, NULL);
 	call_rcu(&p->rcu, __tcindex_destroy);
 	return true;
 }