Merge branch 'nexthop-Small-changes'

Ido Schimmel says:

====================
nexthop: Small changes

This patch set contains a few small changes that I split out of the RFC
I sent last week [1]. Main change is the conversion of the nexthop
notification chain to a blocking chain so that it could be reused by
device drivers for nexthop objects programming in the future.

Tested with fib_nexthops.sh:

Tests passed: 164
Tests failed:   0

[1] https://lore.kernel.org/netdev/20200908091037.2709823-1-idosch@idosch.org/
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/netns/nexthop.h

@@ -14,6 +14,6 @@ struct netns_nexthop {
 
 	unsigned int		seq;		/* protected by rtnl_mutex */
 	u32			last_id_allocated;
-	struct atomic_notifier_head notifier_chain;
+	struct blocking_notifier_head notifier_chain;
 };
 #endif

include/net/nexthop.h

@@ -105,13 +105,9 @@ struct nexthop {
 };
 
 enum nexthop_event_type {
-	NEXTHOP_EVENT_ADD,
 	NEXTHOP_EVENT_DEL
 };
 
-int call_nexthop_notifier(struct notifier_block *nb, struct net *net,
-			  enum nexthop_event_type event_type,
-			  struct nexthop *nh);
 int register_nexthop_notifier(struct net *net, struct notifier_block *nb);
 int unregister_nexthop_notifier(struct net *net, struct notifier_block *nb);
 

net/ipv4/nexthop.c

@@ -42,8 +42,8 @@ static int call_nexthop_notifiers(struct net *net,
 {
 	int err;
 
-	err = atomic_notifier_call_chain(&net->nexthop.notifier_chain,
-					 event_type, nh);
+	err = blocking_notifier_call_chain(&net->nexthop.notifier_chain,
+					   event_type, nh);
 	return notifier_to_errno(err);
 }
 
@@ -870,8 +870,6 @@ static void __remove_nexthop_fib(struct net *net, struct nexthop *nh)
 	bool do_flush = false;
 	struct fib_info *fi;
 
-	call_nexthop_notifiers(net, NEXTHOP_EVENT_DEL, nh);
-
 	list_for_each_entry(fi, &nh->fi_list, nh_list) {
 		fi->fib_flags |= RTNH_F_DEAD;
 		do_flush = true;
@@ -909,6 +907,8 @@ static void __remove_nexthop(struct net *net, struct nexthop *nh,
 static void remove_nexthop(struct net *net, struct nexthop *nh,
 			   struct nl_info *nlinfo)
 {
+	call_nexthop_notifiers(net, NEXTHOP_EVENT_DEL, nh);
+
 	/* remove from the tree */
 	rb_erase(&nh->rb_node, &net->nexthop.rb_root);
 
@@ -1959,14 +1959,15 @@ static struct notifier_block nh_netdev_notifier = {
 
 int register_nexthop_notifier(struct net *net, struct notifier_block *nb)
 {
-	return atomic_notifier_chain_register(&net->nexthop.notifier_chain, nb);
+	return blocking_notifier_chain_register(&net->nexthop.notifier_chain,
+						nb);
 }
 EXPORT_SYMBOL(register_nexthop_notifier);
 
 int unregister_nexthop_notifier(struct net *net, struct notifier_block *nb)
 {
-	return atomic_notifier_chain_unregister(&net->nexthop.notifier_chain,
-						nb);
+	return blocking_notifier_chain_unregister(&net->nexthop.notifier_chain,
+						  nb);
 }
 EXPORT_SYMBOL(unregister_nexthop_notifier);
 
@@ -1986,7 +1987,7 @@ static int __net_init nexthop_net_init(struct net *net)
 	net->nexthop.devhash = kzalloc(sz, GFP_KERNEL);
 	if (!net->nexthop.devhash)
 		return -ENOMEM;
-	ATOMIC_INIT_NOTIFIER_HEAD(&net->nexthop.notifier_chain);
+	BLOCKING_INIT_NOTIFIER_HEAD(&net->nexthop.notifier_chain);
 
 	return 0;
 }

tools/testing/selftests/net/fib_nexthops.sh

@@ -411,9 +411,16 @@ ipv6_fdb_grp_fcnal()
 	run_cmd "$IP -6 ro add 2001:db8:101::1/128 nhid 103"
 	log_test $? 2 "Route add with fdb nexthop group"
 
+	run_cmd "$IP nexthop del id 61"
+	run_cmd "$BRIDGE fdb get to 02:02:00:00:00:13 dev vx10 self"
+	log_test $? 0 "Fdb entry after deleting a single nexthop"
+
 	run_cmd "$IP nexthop del id 102"
 	log_test $? 0 "Fdb nexthop delete"
 
+	run_cmd "$BRIDGE fdb get to 02:02:00:00:00:13 dev vx10 self"
+	log_test $? 254 "Fdb entry after deleting a nexthop group"
+
 	$IP link del dev vx10
 }
 
@@ -484,9 +491,16 @@ ipv4_fdb_grp_fcnal()
 	run_cmd "$IP ro add 172.16.0.0/22 nhid 103"
 	log_test $? 2 "Route add with fdb nexthop group"
 
+	run_cmd "$IP nexthop del id 12"
+	run_cmd "$BRIDGE fdb get to 02:02:00:00:00:13 dev vx10 self"
+	log_test $? 0 "Fdb entry after deleting a single nexthop"
+
 	run_cmd "$IP nexthop del id 102"
 	log_test $? 0 "Fdb nexthop delete"
 
+	run_cmd "$BRIDGE fdb get to 02:02:00:00:00:13 dev vx10 self"
+	log_test $? 254 "Fdb entry after deleting a nexthop group"
+
 	$IP link del dev vx10
 }