net: sched: extend proto ops to support unlocked classifiers

Add 'rtnl_held' flag to tcf proto change, delete, destroy, dump, walk
functions to track rtnl lock status. Extend users of these function in cls
API to propagate rtnl lock status to them. This allows classifiers to
obtain rtnl lock when necessary and to pass rtnl lock status to extensions
and driver offload callbacks.

Add flags field to tcf proto ops. Add flag value to indicate that
classifier doesn't require rtnl lock.

Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

13 files changed, 178 insertions, 135 deletions

diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index 8fe38aa180cf..e8ed461e94af 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -69,7 +69,8 @@ static const struct tcf_proto_ops *__tcf_proto_lookup_ops(const char *kind)
 }
 
 static const struct tcf_proto_ops *
-tcf_proto_lookup_ops(const char *kind, struct netlink_ext_ack *extack)
+tcf_proto_lookup_ops(const char *kind, bool rtnl_held,
+		     struct netlink_ext_ack *extack)
 {
 	const struct tcf_proto_ops *ops;
 
@@ -77,9 +78,11 @@ tcf_proto_lookup_ops(const char *kind, struct netlink_ext_ack *extack)
 	if (ops)
 		return ops;
 #ifdef CONFIG_MODULES
-	rtnl_unlock();
+	if (rtnl_held)
+		rtnl_unlock();
 	request_module("cls_%s", kind);
-	rtnl_lock();
+	if (rtnl_held)
+		rtnl_lock();
 	ops = __tcf_proto_lookup_ops(kind);
 	/* We dropped the RTNL semaphore in order to perform
 	 * the module load. So, even if we succeeded in loading
@@ -162,6 +165,7 @@ static inline u32 tcf_auto_prio(struct tcf_proto *tp)
 
 static struct tcf_proto *tcf_proto_create(const char *kind, u32 protocol,
 					  u32 prio, struct tcf_chain *chain,
+					  bool rtnl_held,
 					  struct netlink_ext_ack *extack)
 {
 	struct tcf_proto *tp;
@@ -171,7 +175,7 @@ static struct tcf_proto *tcf_proto_create(const char *kind, u32 protocol,
 	if (!tp)
 		return ERR_PTR(-ENOBUFS);
 
-	tp->ops = tcf_proto_lookup_ops(kind, extack);
+	tp->ops = tcf_proto_lookup_ops(kind, rtnl_held, extack);
 	if (IS_ERR(tp->ops)) {
 		err = PTR_ERR(tp->ops);
 		goto errout;
@@ -202,20 +206,20 @@ static void tcf_proto_get(struct tcf_proto *tp)
 
 static void tcf_chain_put(struct tcf_chain *chain);
 
-static void tcf_proto_destroy(struct tcf_proto *tp,
+static void tcf_proto_destroy(struct tcf_proto *tp, bool rtnl_held,
 			      struct netlink_ext_ack *extack)
 {
-	tp->ops->destroy(tp, extack);
+	tp->ops->destroy(tp, rtnl_held, extack);
 	tcf_chain_put(tp->chain);
 	module_put(tp->ops->owner);
 	kfree_rcu(tp, rcu);
 }
 
-static void tcf_proto_put(struct tcf_proto *tp,
+static void tcf_proto_put(struct tcf_proto *tp, bool rtnl_held,
 			  struct netlink_ext_ack *extack)
 {
 	if (refcount_dec_and_test(&tp->refcnt))
-		tcf_proto_destroy(tp, extack);
+		tcf_proto_destroy(tp, rtnl_held, extack);
 }
 
 static int walker_noop(struct tcf_proto *tp, void *d, struct tcf_walker *arg)
@@ -223,21 +227,21 @@ static int walker_noop(struct tcf_proto *tp, void *d, struct tcf_walker *arg)
 	return -1;
 }
 
-static bool tcf_proto_is_empty(struct tcf_proto *tp)
+static bool tcf_proto_is_empty(struct tcf_proto *tp, bool rtnl_held)
 {
 	struct tcf_walker walker = { .fn = walker_noop, };
 
 	if (tp->ops->walk) {
-		tp->ops->walk(tp, &walker);
+		tp->ops->walk(tp, &walker, rtnl_held);
 		return !walker.stop;
 	}
 	return true;
 }
 
-static bool tcf_proto_check_delete(struct tcf_proto *tp)
+static bool tcf_proto_check_delete(struct tcf_proto *tp, bool rtnl_held)
 {
 	spin_lock(&tp->lock);
-	if (tcf_proto_is_empty(tp))
+	if (tcf_proto_is_empty(tp, rtnl_held))
 		tp->deleting = true;
 	spin_unlock(&tp->lock);
 	return tp->deleting;
@@ -506,7 +510,7 @@ static void tcf_chain_put_explicitly_created(struct tcf_chain *chain)
 	__tcf_chain_put(chain, false, true);
 }
 
-static void tcf_chain_flush(struct tcf_chain *chain)
+static void tcf_chain_flush(struct tcf_chain *chain, bool rtnl_held)
 {
 	struct tcf_proto *tp, *tp_next;
 
@@ -519,7 +523,7 @@ static void tcf_chain_flush(struct tcf_chain *chain)
 
 	while (tp) {
 		tp_next = rcu_dereference_protected(tp->next, 1);
-		tcf_proto_put(tp, NULL);
+		tcf_proto_put(tp, rtnl_held, NULL);
 		tp = tp_next;
 	}
 }
@@ -1070,18 +1074,19 @@ __tcf_get_next_proto(struct tcf_chain *chain, struct tcf_proto *tp)
  */
 
 struct tcf_proto *
-tcf_get_next_proto(struct tcf_chain *chain, struct tcf_proto *tp)
+tcf_get_next_proto(struct tcf_chain *chain, struct tcf_proto *tp,
+		   bool rtnl_held)
 {
 	struct tcf_proto *tp_next = __tcf_get_next_proto(chain, tp);
 
 	if (tp)
-		tcf_proto_put(tp, NULL);
+		tcf_proto_put(tp, rtnl_held, NULL);
 
 	return tp_next;
 }
 EXPORT_SYMBOL(tcf_get_next_proto);
 
-static void tcf_block_flush_all_chains(struct tcf_block *block)
+static void tcf_block_flush_all_chains(struct tcf_block *block, bool rtnl_held)
 {
 	struct tcf_chain *chain;
 
@@ -1092,12 +1097,12 @@ static void tcf_block_flush_all_chains(struct tcf_block *block)
 	     chain;
 	     chain = tcf_get_next_chain(block, chain)) {
 		tcf_chain_put_explicitly_created(chain);
-		tcf_chain_flush(chain);
+		tcf_chain_flush(chain, rtnl_held);
 	}
 }
 
 static void __tcf_block_put(struct tcf_block *block, struct Qdisc *q,
-			    struct tcf_block_ext_info *ei)
+			    struct tcf_block_ext_info *ei, bool rtnl_held)
 {
 	if (refcount_dec_and_mutex_lock(&block->refcnt, &block->lock)) {
 		/* Flushing/putting all chains will cause the block to be
@@ -1118,15 +1123,15 @@ static void __tcf_block_put(struct tcf_block *block, struct Qdisc *q,
 		if (free_block)
 			tcf_block_destroy(block);
 		else
-			tcf_block_flush_all_chains(block);
+			tcf_block_flush_all_chains(block, rtnl_held);
 	} else if (q) {
 		tcf_block_offload_unbind(block, q, ei);
 	}
 }
 
-static void tcf_block_refcnt_put(struct tcf_block *block)
+static void tcf_block_refcnt_put(struct tcf_block *block, bool rtnl_held)
 {
-	__tcf_block_put(block, NULL, NULL);
+	__tcf_block_put(block, NULL, NULL, rtnl_held);
 }
 
 /* Find tcf block.
@@ -1244,10 +1249,11 @@ errout_qdisc:
 	return ERR_PTR(err);
 }
 
-static void tcf_block_release(struct Qdisc *q, struct tcf_block *block)
+static void tcf_block_release(struct Qdisc *q, struct tcf_block *block,
+			      bool rtnl_held)
 {
 	if (!IS_ERR_OR_NULL(block))
-		tcf_block_refcnt_put(block);
+		tcf_block_refcnt_put(block, rtnl_held);
 
 	if (q)
 		qdisc_put(q);
@@ -1358,7 +1364,7 @@ err_chain0_head_change_cb_add:
 	tcf_block_owner_del(block, q, ei->binder_type);
 err_block_owner_add:
 err_block_insert:
-	tcf_block_refcnt_put(block);
+	tcf_block_refcnt_put(block, true);
 	return err;
 }
 EXPORT_SYMBOL(tcf_block_get_ext);
@@ -1395,7 +1401,7 @@ void tcf_block_put_ext(struct tcf_block *block, struct Qdisc *q,
 	tcf_chain0_head_change_cb_del(block, ei);
 	tcf_block_owner_del(block, q, ei->binder_type);
 
-	__tcf_block_put(block, q, ei);
+	__tcf_block_put(block, q, ei, true);
 }
 EXPORT_SYMBOL(tcf_block_put_ext);
 
@@ -1464,7 +1470,7 @@ tcf_block_playback_offloads(struct tcf_block *block, tc_setup_cb_t *cb,
 		for (tp = __tcf_get_next_proto(chain, NULL); tp;
 		     tp_prev = tp,
 			     tp = __tcf_get_next_proto(chain, tp),
-			     tcf_proto_put(tp_prev, NULL)) {
+			     tcf_proto_put(tp_prev, true, NULL)) {
 			if (tp->ops->reoffload) {
 				err = tp->ops->reoffload(tp, add, cb, cb_priv,
 							 extack);
@@ -1481,7 +1487,7 @@ tcf_block_playback_offloads(struct tcf_block *block, tc_setup_cb_t *cb,
 	return 0;
 
 err_playback_remove:
-	tcf_proto_put(tp, NULL);
+	tcf_proto_put(tp, true, NULL);
 	tcf_chain_put(chain);
 	tcf_block_playback_offloads(block, cb, cb_priv, false, offload_in_use,
 				    extack);
@@ -1654,7 +1660,8 @@ static struct tcf_proto *tcf_chain_tp_find(struct tcf_chain *chain,
 
 static struct tcf_proto *tcf_chain_tp_insert_unique(struct tcf_chain *chain,
 						    struct tcf_proto *tp_new,
-						    u32 protocol, u32 prio)
+						    u32 protocol, u32 prio,
+						    bool rtnl_held)
 {
 	struct tcf_chain_info chain_info;
 	struct tcf_proto *tp;
@@ -1669,10 +1676,10 @@ static struct tcf_proto *tcf_chain_tp_insert_unique(struct tcf_chain *chain,
 	mutex_unlock(&chain->filter_chain_lock);
 
 	if (tp) {
-		tcf_proto_destroy(tp_new, NULL);
+		tcf_proto_destroy(tp_new, rtnl_held, NULL);
 		tp_new = tp;
 	} else if (err) {
-		tcf_proto_destroy(tp_new, NULL);
+		tcf_proto_destroy(tp_new, rtnl_held, NULL);
 		tp_new = ERR_PTR(err);
 	}
 
@@ -1680,7 +1687,7 @@ static struct tcf_proto *tcf_chain_tp_insert_unique(struct tcf_chain *chain,
 }
 
 static void tcf_chain_tp_delete_empty(struct tcf_chain *chain,
-				      struct tcf_proto *tp,
+				      struct tcf_proto *tp, bool rtnl_held,
 				      struct netlink_ext_ack *extack)
 {
 	struct tcf_chain_info chain_info;
@@ -1705,7 +1712,7 @@ static void tcf_chain_tp_delete_empty(struct tcf_chain *chain,
 	 * concurrently.
 	 * Mark tp for deletion if it is empty.
 	 */
-	if (!tp_iter || !tcf_proto_check_delete(tp)) {
+	if (!tp_iter || !tcf_proto_check_delete(tp, rtnl_held)) {
 		mutex_unlock(&chain->filter_chain_lock);
 		return;
 	}
@@ -1716,7 +1723,7 @@ static void tcf_chain_tp_delete_empty(struct tcf_chain *chain,
 	RCU_INIT_POINTER(*chain_info.pprev, next);
 	mutex_unlock(&chain->filter_chain_lock);
 
-	tcf_proto_put(tp, extack);
+	tcf_proto_put(tp, rtnl_held, extack);
 }
 
 static struct tcf_proto *tcf_chain_tp_find(struct tcf_chain *chain,
@@ -1755,7 +1762,8 @@ static struct tcf_proto *tcf_chain_tp_find(struct tcf_chain *chain,
 static int tcf_fill_node(struct net *net, struct sk_buff *skb,
 			 struct tcf_proto *tp, struct tcf_block *block,
 			 struct Qdisc *q, u32 parent, void *fh,
-			 u32 portid, u32 seq, u16 flags, int event)
+			 u32 portid, u32 seq, u16 flags, int event,
+			 bool rtnl_held)
 {
 	struct tcmsg *tcm;
 	struct nlmsghdr  *nlh;
@@ -1783,7 +1791,8 @@ static int tcf_fill_node(struct net *net, struct sk_buff *skb,
 	if (!fh) {
 		tcm->tcm_handle = 0;
 	} else {
-		if (tp->ops->dump && tp->ops->dump(net, tp, fh, skb, tcm) < 0)
+		if (tp->ops->dump &&
+		    tp->ops->dump(net, tp, fh, skb, tcm, rtnl_held) < 0)
 			goto nla_put_failure;
 	}
 	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
@@ -1798,7 +1807,8 @@ nla_put_failure:
 static int tfilter_notify(struct net *net, struct sk_buff *oskb,
 			  struct nlmsghdr *n, struct tcf_proto *tp,
 			  struct tcf_block *block, struct Qdisc *q,
-			  u32 parent, void *fh, int event, bool unicast)
+			  u32 parent, void *fh, int event, bool unicast,
+			  bool rtnl_held)
 {
 	struct sk_buff *skb;
 	u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
@@ -1808,7 +1818,8 @@ static int tfilter_notify(struct net *net, struct sk_buff *oskb,
 		return -ENOBUFS;
 
 	if (tcf_fill_node(net, skb, tp, block, q, parent, fh, portid,
-			  n->nlmsg_seq, n->nlmsg_flags, event) <= 0) {
+			  n->nlmsg_seq, n->nlmsg_flags, event,
+			  rtnl_held) <= 0) {
 		kfree_skb(skb);
 		return -EINVAL;
 	}
@@ -1824,7 +1835,7 @@ static int tfilter_del_notify(struct net *net, struct sk_buff *oskb,
 			      struct nlmsghdr *n, struct tcf_proto *tp,
 			      struct tcf_block *block, struct Qdisc *q,
 			      u32 parent, void *fh, bool unicast, bool *last,
-			      struct netlink_ext_ack *extack)
+			      bool rtnl_held, struct netlink_ext_ack *extack)
 {
 	struct sk_buff *skb;
 	u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
@@ -1835,13 +1846,14 @@ static int tfilter_del_notify(struct net *net, struct sk_buff *oskb,
 		return -ENOBUFS;
 
 	if (tcf_fill_node(net, skb, tp, block, q, parent, fh, portid,
-			  n->nlmsg_seq, n->nlmsg_flags, RTM_DELTFILTER) <= 0) {
+			  n->nlmsg_seq, n->nlmsg_flags, RTM_DELTFILTER,
+			  rtnl_held) <= 0) {
 		NL_SET_ERR_MSG(extack, "Failed to build del event notification");
 		kfree_skb(skb);
 		return -EINVAL;
 	}
 
-	err = tp->ops->delete(tp, fh, last, extack);
+	err = tp->ops->delete(tp, fh, last, rtnl_held, extack);
 	if (err) {
 		kfree_skb(skb);
 		return err;
@@ -1860,14 +1872,15 @@ static int tfilter_del_notify(struct net *net, struct sk_buff *oskb,
 static void tfilter_notify_chain(struct net *net, struct sk_buff *oskb,
 				 struct tcf_block *block, struct Qdisc *q,
 				 u32 parent, struct nlmsghdr *n,
-				 struct tcf_chain *chain, int event)
+				 struct tcf_chain *chain, int event,
+				 bool rtnl_held)
 {
 	struct tcf_proto *tp;
 
-	for (tp = tcf_get_next_proto(chain, NULL);
-	     tp; tp = tcf_get_next_proto(chain, tp))
+	for (tp = tcf_get_next_proto(chain, NULL, rtnl_held);
+	     tp; tp = tcf_get_next_proto(chain, tp, rtnl_held))
 		tfilter_notify(net, oskb, n, tp, block,
-			       q, parent, NULL, event, false);
+			       q, parent, NULL, event, false, rtnl_held);
 }
 
 static void tfilter_put(struct tcf_proto *tp, void *fh)
@@ -1896,6 +1909,7 @@ static int tc_new_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
 	void *fh;
 	int err;
 	int tp_created;
+	bool rtnl_held = true;
 
 	if (!netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
 		return -EPERM;
@@ -1987,14 +2001,16 @@ replay:
 
 		mutex_unlock(&chain->filter_chain_lock);
 		tp_new = tcf_proto_create(nla_data(tca[TCA_KIND]),
-					  protocol, prio, chain, extack);
+					  protocol, prio, chain, rtnl_held,
+					  extack);
 		if (IS_ERR(tp_new)) {
 			err = PTR_ERR(tp_new);
 			goto errout_tp;
 		}
 
 		tp_created = 1;
-		tp = tcf_chain_tp_insert_unique(chain, tp_new, protocol, prio);
+		tp = tcf_chain_tp_insert_unique(chain, tp_new, protocol, prio,
+						rtnl_held);
 		if (IS_ERR(tp)) {
 			err = PTR_ERR(tp);
 			goto errout_tp;
@@ -2032,24 +2048,24 @@ replay:
 
 	err = tp->ops->change(net, skb, tp, cl, t->tcm_handle, tca, &fh,
 			      n->nlmsg_flags & NLM_F_CREATE ? TCA_ACT_NOREPLACE : TCA_ACT_REPLACE,
-			      extack);
+			      rtnl_held, extack);
 	if (err == 0) {
 		tfilter_notify(net, skb, n, tp, block, q, parent, fh,
-			       RTM_NEWTFILTER, false);
+			       RTM_NEWTFILTER, false, rtnl_held);
 		tfilter_put(tp, fh);
 	}
 
 errout:
 	if (err && tp_created)
-		tcf_chain_tp_delete_empty(chain, tp, NULL);
+		tcf_chain_tp_delete_empty(chain, tp, rtnl_held, NULL);
 errout_tp:
 	if (chain) {
 		if (tp && !IS_ERR(tp))
-			tcf_proto_put(tp, NULL);
+			tcf_proto_put(tp, rtnl_held, NULL);
 		if (!tp_created)
 			tcf_chain_put(chain);
 	}
-	tcf_block_release(q, block);
+	tcf_block_release(q, block, rtnl_held);
 	if (err == -EAGAIN)
 		/* Replay the request. */
 		goto replay;
@@ -2078,6 +2094,7 @@ static int tc_del_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
 	unsigned long cl = 0;
 	void *fh = NULL;
 	int err;
+	bool rtnl_held = true;
 
 	if (!netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
 		return -EPERM;
@@ -2127,8 +2144,8 @@ static int tc_del_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
 
 	if (prio == 0) {
 		tfilter_notify_chain(net, skb, block, q, parent, n,
-				     chain, RTM_DELTFILTER);
-		tcf_chain_flush(chain);
+				     chain, RTM_DELTFILTER, rtnl_held);
+		tcf_chain_flush(chain, rtnl_held);
 		err = 0;
 		goto errout;
 	}
@@ -2148,9 +2165,9 @@ static int tc_del_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
 		tcf_chain_tp_remove(chain, &chain_info, tp);
 		mutex_unlock(&chain->filter_chain_lock);
 
-		tcf_proto_put(tp, NULL);
+		tcf_proto_put(tp, rtnl_held, NULL);
 		tfilter_notify(net, skb, n, tp, block, q, parent, fh,
-			       RTM_DELTFILTER, false);
+			       RTM_DELTFILTER, false, rtnl_held);
 		err = 0;
 		goto errout;
 	}
@@ -2166,20 +2183,21 @@ static int tc_del_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
 
 		err = tfilter_del_notify(net, skb, n, tp, block,
 					 q, parent, fh, false, &last,
-					 extack);
+					 rtnl_held, extack);
+
 		if (err)
 			goto errout;
 		if (last)
-			tcf_chain_tp_delete_empty(chain, tp, extack);
+			tcf_chain_tp_delete_empty(chain, tp, rtnl_held, extack);
 	}
 
 errout:
 	if (chain) {
 		if (tp && !IS_ERR(tp))
-			tcf_proto_put(tp, NULL);
+			tcf_proto_put(tp, rtnl_held, NULL);
 		tcf_chain_put(chain);
 	}
-	tcf_block_release(q, block);
+	tcf_block_release(q, block, rtnl_held);
 	return err;
 
 errout_locked:
@@ -2205,6 +2223,7 @@ static int tc_get_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
 	unsigned long cl = 0;
 	void *fh = NULL;
 	int err;
+	bool rtnl_held = true;
 
 	err = nlmsg_parse(n, sizeof(*t), tca, TCA_MAX, rtm_tca_policy, extack);
 	if (err < 0)
@@ -2263,7 +2282,7 @@ static int tc_get_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
 		err = -ENOENT;
 	} else {
 		err = tfilter_notify(net, skb, n, tp, block, q, parent,
-				     fh, RTM_NEWTFILTER, true);
+				     fh, RTM_NEWTFILTER, true, rtnl_held);
 		if (err < 0)
 			NL_SET_ERR_MSG(extack, "Failed to send filter notify message");
 	}
@@ -2272,10 +2291,10 @@ static int tc_get_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
 errout:
 	if (chain) {
 		if (tp && !IS_ERR(tp))
-			tcf_proto_put(tp, NULL);
+			tcf_proto_put(tp, rtnl_held, NULL);
 		tcf_chain_put(chain);
 	}
-	tcf_block_release(q, block);
+	tcf_block_release(q, block, rtnl_held);
 	return err;
 }
 
@@ -2296,7 +2315,7 @@ static int tcf_node_dump(struct tcf_proto *tp, void *n, struct tcf_walker *arg)
 	return tcf_fill_node(net, a->skb, tp, a->block, a->q, a->parent,
 			     n, NETLINK_CB(a->cb->skb).portid,
 			     a->cb->nlh->nlmsg_seq, NLM_F_MULTI,
-			     RTM_NEWTFILTER);
+			     RTM_NEWTFILTER, true);
 }
 
 static bool tcf_chain_dump(struct tcf_chain *chain, struct Qdisc *q, u32 parent,
@@ -2313,7 +2332,7 @@ static bool tcf_chain_dump(struct tcf_chain *chain, struct Qdisc *q, u32 parent,
 	     tp;
 	     tp_prev = tp,
 		     tp = __tcf_get_next_proto(chain, tp),
-		     tcf_proto_put(tp_prev, NULL),
+		     tcf_proto_put(tp_prev, true, NULL),
 		     (*p_index)++) {
 		if (*p_index < index_start)
 			continue;
@@ -2330,9 +2349,8 @@ static bool tcf_chain_dump(struct tcf_chain *chain, struct Qdisc *q, u32 parent,
 			if (tcf_fill_node(net, skb, tp, block, q, parent, NULL,
 					  NETLINK_CB(cb->skb).portid,
 					  cb->nlh->nlmsg_seq, NLM_F_MULTI,
-					  RTM_NEWTFILTER) <= 0)
+					  RTM_NEWTFILTER, true) <= 0)
 				goto errout;
-
 			cb->args[1] = 1;
 		}
 		if (!tp->ops->walk)
@@ -2347,7 +2365,7 @@ static bool tcf_chain_dump(struct tcf_chain *chain, struct Qdisc *q, u32 parent,
 		arg.w.skip = cb->args[1] - 1;
 		arg.w.count = 0;
 		arg.w.cookie = cb->args[2];
-		tp->ops->walk(tp, &arg.w);
+		tp->ops->walk(tp, &arg.w, true);
 		cb->args[2] = arg.w.cookie;
 		cb->args[1] = arg.w.count + 1;
 		if (arg.w.stop)
@@ -2356,7 +2374,7 @@ static bool tcf_chain_dump(struct tcf_chain *chain, struct Qdisc *q, u32 parent,
 	return true;
 
 errout:
-	tcf_proto_put(tp, NULL);
+	tcf_proto_put(tp, true, NULL);
 	return false;
 }
 
@@ -2448,7 +2466,7 @@ static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb)
 	}
 
 	if (tcm->tcm_ifindex == TCM_IFINDEX_MAGIC_BLOCK)
-		tcf_block_refcnt_put(block);
+		tcf_block_refcnt_put(block, true);
 	cb->args[0] = index;
 
 out:
@@ -2569,7 +2587,7 @@ static int tc_chain_tmplt_add(struct tcf_chain *chain, struct net *net,
 	if (!tca[TCA_KIND])
 		return 0;
 
-	ops = tcf_proto_lookup_ops(nla_data(tca[TCA_KIND]), extack);
+	ops = tcf_proto_lookup_ops(nla_data(tca[TCA_KIND]), true, extack);
 	if (IS_ERR(ops))
 		return PTR_ERR(ops);
 	if (!ops->tmplt_create || !ops->tmplt_destroy || !ops->tmplt_dump) {
@@ -2699,9 +2717,9 @@ replay:
 		break;
 	case RTM_DELCHAIN:
 		tfilter_notify_chain(net, skb, block, q, parent, n,
-				     chain, RTM_DELTFILTER);
+				     chain, RTM_DELTFILTER, true);
 		/* Flush the chain first as the user requested chain removal. */
-		tcf_chain_flush(chain);
+		tcf_chain_flush(chain, true);
 		/* In case the chain was successfully deleted, put a reference
 		 * to the chain previously taken during addition.
 		 */
@@ -2722,7 +2740,7 @@ replay:
 errout:
 	tcf_chain_put(chain);
 errout_block:
-	tcf_block_release(q, block);
+	tcf_block_release(q, block, true);
 	if (err == -EAGAIN)
 		/* Replay the request. */
 		goto replay;
@@ -2829,7 +2847,7 @@ static int tc_dump_chain(struct sk_buff *skb, struct netlink_callback *cb)
 	}
 
 	if (tcm->tcm_ifindex == TCM_IFINDEX_MAGIC_BLOCK)
-		tcf_block_refcnt_put(block);
+		tcf_block_refcnt_put(block, true);
 	cb->args[0] = index;
 
 out:
diff --git a/net/sched/cls_basic.c b/net/sched/cls_basic.c
index eaf9c02fe792..2383f449d2bc 100644
--- a/net/sched/cls_basic.c
+++ b/net/sched/cls_basic.c
@@ -107,7 +107,8 @@ static void basic_delete_filter_work(struct work_struct *work)
 	rtnl_unlock();
 }
 
-static void basic_destroy(struct tcf_proto *tp, struct netlink_ext_ack *extack)
+static void basic_destroy(struct tcf_proto *tp, bool rtnl_held,
+			  struct netlink_ext_ack *extack)
 {
 	struct basic_head *head = rtnl_dereference(tp->root);
 	struct basic_filter *f, *n;
@@ -126,7 +127,7 @@ static void basic_destroy(struct tcf_proto *tp, struct netlink_ext_ack *extack)
 }
 
 static int basic_delete(struct tcf_proto *tp, void *arg, bool *last,
-			struct netlink_ext_ack *extack)
+			bool rtnl_held, struct netlink_ext_ack *extack)
 {
 	struct basic_head *head = rtnl_dereference(tp->root);
 	struct basic_filter *f = arg;
@@ -173,7 +174,7 @@ static int basic_set_parms(struct net *net, struct tcf_proto *tp,
 static int basic_change(struct net *net, struct sk_buff *in_skb,
 			struct tcf_proto *tp, unsigned long base, u32 handle,
 			struct nlattr **tca, void **arg, bool ovr,
-			struct netlink_ext_ack *extack)
+			bool rtnl_held, struct netlink_ext_ack *extack)
 {
 	int err;
 	struct basic_head *head = rtnl_dereference(tp->root);
@@ -247,7 +248,8 @@ errout:
 	return err;
 }
 
-static void basic_walk(struct tcf_proto *tp, struct tcf_walker *arg)
+static void basic_walk(struct tcf_proto *tp, struct tcf_walker *arg,
+		       bool rtnl_held)
 {
 	struct basic_head *head = rtnl_dereference(tp->root);
 	struct basic_filter *f;
@@ -274,7 +276,7 @@ static void basic_bind_class(void *fh, u32 classid, unsigned long cl)
 }
 
 static int basic_dump(struct net *net, struct tcf_proto *tp, void *fh,
-		      struct sk_buff *skb, struct tcmsg *t)
+		      struct sk_buff *skb, struct tcmsg *t, bool rtnl_held)
 {
 	struct tc_basic_pcnt gpf = {};
 	struct basic_filter *f = fh;
diff --git a/net/sched/cls_bpf.c b/net/sched/cls_bpf.c
index 656b3423ad35..062350c6621c 100644
--- a/net/sched/cls_bpf.c
+++ b/net/sched/cls_bpf.c
@@ -298,7 +298,7 @@ static void __cls_bpf_delete(struct tcf_proto *tp, struct cls_bpf_prog *prog,
 }
 
 static int cls_bpf_delete(struct tcf_proto *tp, void *arg, bool *last,
-			  struct netlink_ext_ack *extack)
+			  bool rtnl_held, struct netlink_ext_ack *extack)
 {
 	struct cls_bpf_head *head = rtnl_dereference(tp->root);
 
@@ -307,7 +307,7 @@ static int cls_bpf_delete(struct tcf_proto *tp, void *arg, bool *last,
 	return 0;
 }
 
-static void cls_bpf_destroy(struct tcf_proto *tp,
+static void cls_bpf_destroy(struct tcf_proto *tp, bool rtnl_held,
 			    struct netlink_ext_ack *extack)
 {
 	struct cls_bpf_head *head = rtnl_dereference(tp->root);
@@ -456,7 +456,8 @@ static int cls_bpf_set_parms(struct net *net, struct tcf_proto *tp,
 static int cls_bpf_change(struct net *net, struct sk_buff *in_skb,
 			  struct tcf_proto *tp, unsigned long base,
 			  u32 handle, struct nlattr **tca,
-			  void **arg, bool ovr, struct netlink_ext_ack *extack)
+			  void **arg, bool ovr, bool rtnl_held,
+			  struct netlink_ext_ack *extack)
 {
 	struct cls_bpf_head *head = rtnl_dereference(tp->root);
 	struct cls_bpf_prog *oldprog = *arg;
@@ -576,7 +577,7 @@ static int cls_bpf_dump_ebpf_info(const struct cls_bpf_prog *prog,
 }
 
 static int cls_bpf_dump(struct net *net, struct tcf_proto *tp, void *fh,
-			struct sk_buff *skb, struct tcmsg *tm)
+			struct sk_buff *skb, struct tcmsg *tm, bool rtnl_held)
 {
 	struct cls_bpf_prog *prog = fh;
 	struct nlattr *nest;
@@ -636,7 +637,8 @@ static void cls_bpf_bind_class(void *fh, u32 classid, unsigned long cl)
 		prog->res.class = cl;
 }
 
-static void cls_bpf_walk(struct tcf_proto *tp, struct tcf_walker *arg)
+static void cls_bpf_walk(struct tcf_proto *tp, struct tcf_walker *arg,
+			 bool rtnl_held)
 {
 	struct cls_bpf_head *head = rtnl_dereference(tp->root);
 	struct cls_bpf_prog *prog;
diff --git a/net/sched/cls_cgroup.c b/net/sched/cls_cgroup.c
index 663ee1c6d606..1cef3b416094 100644
--- a/net/sched/cls_cgroup.c
+++ b/net/sched/cls_cgroup.c
@@ -78,7 +78,7 @@ static void cls_cgroup_destroy_work(struct work_struct *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,
-			     void **arg, bool ovr,
+			     void **arg, bool ovr, bool rtnl_held,
 			     struct netlink_ext_ack *extack)
 {
 	struct nlattr *tb[TCA_CGROUP_MAX + 1];
@@ -130,7 +130,7 @@ errout:
 	return err;
 }
 
-static void cls_cgroup_destroy(struct tcf_proto *tp,
+static void cls_cgroup_destroy(struct tcf_proto *tp, bool rtnl_held,
 			       struct netlink_ext_ack *extack)
 {
 	struct cls_cgroup_head *head = rtnl_dereference(tp->root);
@@ -145,12 +145,13 @@ static void cls_cgroup_destroy(struct tcf_proto *tp,
 }
 
 static int cls_cgroup_delete(struct tcf_proto *tp, void *arg, bool *last,
-			     struct netlink_ext_ack *extack)
+			     bool rtnl_held, struct netlink_ext_ack *extack)
 {
 	return -EOPNOTSUPP;
 }
 
-static void cls_cgroup_walk(struct tcf_proto *tp, struct tcf_walker *arg)
+static void cls_cgroup_walk(struct tcf_proto *tp, struct tcf_walker *arg,
+			    bool rtnl_held)
 {
 	struct cls_cgroup_head *head = rtnl_dereference(tp->root);
 
@@ -166,7 +167,7 @@ skip:
 }
 
 static int cls_cgroup_dump(struct net *net, struct tcf_proto *tp, void *fh,
-			   struct sk_buff *skb, struct tcmsg *t)
+			   struct sk_buff *skb, struct tcmsg *t, bool rtnl_held)
 {
 	struct cls_cgroup_head *head = rtnl_dereference(tp->root);
 	struct nlattr *nest;
diff --git a/net/sched/cls_flow.c b/net/sched/cls_flow.c
index 39a6407d4832..204e2edae8d5 100644
--- a/net/sched/cls_flow.c
+++ b/net/sched/cls_flow.c
@@ -391,7 +391,8 @@ static void flow_destroy_filter_work(struct work_struct *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,
-		       void **arg, bool ovr, struct netlink_ext_ack *extack)
+		       void **arg, bool ovr, bool rtnl_held,
+		       struct netlink_ext_ack *extack)
 {
 	struct flow_head *head = rtnl_dereference(tp->root);
 	struct flow_filter *fold, *fnew;
@@ -566,7 +567,7 @@ err1:
 }
 
 static int flow_delete(struct tcf_proto *tp, void *arg, bool *last,
-		       struct netlink_ext_ack *extack)
+		       bool rtnl_held, struct netlink_ext_ack *extack)
 {
 	struct flow_head *head = rtnl_dereference(tp->root);
 	struct flow_filter *f = arg;
@@ -590,7 +591,8 @@ static int flow_init(struct tcf_proto *tp)
 	return 0;
 }
 
-static void flow_destroy(struct tcf_proto *tp, struct netlink_ext_ack *extack)
+static void flow_destroy(struct tcf_proto *tp, bool rtnl_held,
+			 struct netlink_ext_ack *extack)
 {
 	struct flow_head *head = rtnl_dereference(tp->root);
 	struct flow_filter *f, *next;
@@ -617,7 +619,7 @@ static void *flow_get(struct tcf_proto *tp, u32 handle)
 }
 
 static int flow_dump(struct net *net, struct tcf_proto *tp, void *fh,
-		     struct sk_buff *skb, struct tcmsg *t)
+		     struct sk_buff *skb, struct tcmsg *t, bool rtnl_held)
 {
 	struct flow_filter *f = fh;
 	struct nlattr *nest;
@@ -677,7 +679,8 @@ nla_put_failure:
 	return -1;
 }
 
-static void flow_walk(struct tcf_proto *tp, struct tcf_walker *arg)
+static void flow_walk(struct tcf_proto *tp, struct tcf_walker *arg,
+		      bool rtnl_held)
 {
 	struct flow_head *head = rtnl_dereference(tp->root);
 	struct flow_filter *f;
diff --git a/net/sched/cls_flower.c b/net/sched/cls_flower.c
index 5e3f74ab68ca..32fa3e20adc5 100644
--- a/net/sched/cls_flower.c
+++ b/net/sched/cls_flower.c
@@ -465,7 +465,8 @@ static void fl_destroy_sleepable(struct work_struct *work)
 	module_put(THIS_MODULE);
 }
 
-static void fl_destroy(struct tcf_proto *tp, struct netlink_ext_ack *extack)
+static void fl_destroy(struct tcf_proto *tp, bool rtnl_held,
+		       struct netlink_ext_ack *extack)
 {
 	struct cls_fl_head *head = rtnl_dereference(tp->root);
 	struct fl_flow_mask *mask, *next_mask;
@@ -1300,7 +1301,8 @@ static int fl_set_parms(struct net *net, struct tcf_proto *tp,
 static int fl_change(struct net *net, struct sk_buff *in_skb,
 		     struct tcf_proto *tp, unsigned long base,
 		     u32 handle, struct nlattr **tca,
-		     void **arg, bool ovr, struct netlink_ext_ack *extack)
+		     void **arg, bool ovr, bool rtnl_held,
+		     struct netlink_ext_ack *extack)
 {
 	struct cls_fl_head *head = rtnl_dereference(tp->root);
 	struct cls_fl_filter *fold = *arg;
@@ -1437,7 +1439,7 @@ errout_mask_alloc:
 }
 
 static int fl_delete(struct tcf_proto *tp, void *arg, bool *last,
-		     struct netlink_ext_ack *extack)
+		     bool rtnl_held, struct netlink_ext_ack *extack)
 {
 	struct cls_fl_head *head = rtnl_dereference(tp->root);
 	struct cls_fl_filter *f = arg;
@@ -1449,7 +1451,8 @@ static int fl_delete(struct tcf_proto *tp, void *arg, bool *last,
 	return 0;
 }
 
-static void fl_walk(struct tcf_proto *tp, struct tcf_walker *arg)
+static void fl_walk(struct tcf_proto *tp, struct tcf_walker *arg,
+		    bool rtnl_held)
 {
 	struct cls_fl_head *head = rtnl_dereference(tp->root);
 	struct cls_fl_filter *f;
@@ -2044,7 +2047,7 @@ nla_put_failure:
 }
 
 static int fl_dump(struct net *net, struct tcf_proto *tp, void *fh,
-		   struct sk_buff *skb, struct tcmsg *t)
+		   struct sk_buff *skb, struct tcmsg *t, bool rtnl_held)
 {
 	struct cls_fl_filter *f = fh;
 	struct nlattr *nest;
diff --git a/net/sched/cls_fw.c b/net/sched/cls_fw.c
index c8173ebb69f2..317151bae73b 100644
--- a/net/sched/cls_fw.c
+++ b/net/sched/cls_fw.c
@@ -139,7 +139,8 @@ static void fw_delete_filter_work(struct work_struct *work)
 	rtnl_unlock();
 }
 
-static void fw_destroy(struct tcf_proto *tp, struct netlink_ext_ack *extack)
+static void fw_destroy(struct tcf_proto *tp, bool rtnl_held,
+		       struct netlink_ext_ack *extack)
 {
 	struct fw_head *head = rtnl_dereference(tp->root);
 	struct fw_filter *f;
@@ -163,7 +164,7 @@ static void fw_destroy(struct tcf_proto *tp, struct netlink_ext_ack *extack)
 }
 
 static int fw_delete(struct tcf_proto *tp, void *arg, bool *last,
-		     struct netlink_ext_ack *extack)
+		     bool rtnl_held, struct netlink_ext_ack *extack)
 {
 	struct fw_head *head = rtnl_dereference(tp->root);
 	struct fw_filter *f = arg;
@@ -250,7 +251,8 @@ static int fw_set_parms(struct net *net, struct tcf_proto *tp,
 static int fw_change(struct net *net, struct sk_buff *in_skb,
 		     struct tcf_proto *tp, unsigned long base,
 		     u32 handle, struct nlattr **tca, void **arg,
-		     bool ovr, struct netlink_ext_ack *extack)
+		     bool ovr, bool rtnl_held,
+		     struct netlink_ext_ack *extack)
 {
 	struct fw_head *head = rtnl_dereference(tp->root);
 	struct fw_filter *f = *arg;
@@ -354,7 +356,8 @@ errout:
 	return err;
 }
 
-static void fw_walk(struct tcf_proto *tp, struct tcf_walker *arg)
+static void fw_walk(struct tcf_proto *tp, struct tcf_walker *arg,
+		    bool rtnl_held)
 {
 	struct fw_head *head = rtnl_dereference(tp->root);
 	int h;
@@ -384,7 +387,7 @@ static void fw_walk(struct tcf_proto *tp, struct tcf_walker *arg)
 }
 
 static int fw_dump(struct net *net, struct tcf_proto *tp, void *fh,
-		   struct sk_buff *skb, struct tcmsg *t)
+		   struct sk_buff *skb, struct tcmsg *t, bool rtnl_held)
 {
 	struct fw_head *head = rtnl_dereference(tp->root);
 	struct fw_filter *f = fh;
diff --git a/net/sched/cls_matchall.c b/net/sched/cls_matchall.c
index 8848a147c4bf..a37137430e61 100644
--- a/net/sched/cls_matchall.c
+++ b/net/sched/cls_matchall.c
@@ -109,7 +109,8 @@ static int mall_replace_hw_filter(struct tcf_proto *tp,
 	return 0;
 }
 
-static void mall_destroy(struct tcf_proto *tp, struct netlink_ext_ack *extack)
+static void mall_destroy(struct tcf_proto *tp, bool rtnl_held,
+			 struct netlink_ext_ack *extack)
 {
 	struct cls_mall_head *head = rtnl_dereference(tp->root);
 
@@ -160,7 +161,8 @@ static int mall_set_parms(struct net *net, struct tcf_proto *tp,
 static int mall_change(struct net *net, struct sk_buff *in_skb,
 		       struct tcf_proto *tp, unsigned long base,
 		       u32 handle, struct nlattr **tca,
-		       void **arg, bool ovr, struct netlink_ext_ack *extack)
+		       void **arg, bool ovr, bool rtnl_held,
+		       struct netlink_ext_ack *extack)
 {
 	struct cls_mall_head *head = rtnl_dereference(tp->root);
 	struct nlattr *tb[TCA_MATCHALL_MAX +