Merge branch 'mlxsw-IPv6-and-reference-counting-fixes'

Ido Schimmel says:

====================
mlxsw: IPv6 and reference counting fixes

The first three patches fix a mismatch between the new IPv6 behavior
introduced in commit f34436a4 ("net/ipv6: Simplify route replace and
appending into multipath route") and mlxsw. The patches allow the driver
to support multipathing in IPv6 overlays with GRE tunnel devices. A
selftest will be submitted when net-next opens.

The last patch fixes a reference count problem of the port_vlan struct.
I plan to simplify the code in net-next, so that reference counting is
not necessary anymore.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c

@@ -4756,12 +4756,6 @@ static void mlxsw_sp_rt6_destroy(struct mlxsw_sp_rt6 *mlxsw_sp_rt6)
 	kfree(mlxsw_sp_rt6);
 }
 
-static bool mlxsw_sp_fib6_rt_can_mp(const struct fib6_info *rt)
-{
-	/* RTF_CACHE routes are ignored */
-	return (rt->fib6_flags & (RTF_GATEWAY | RTF_ADDRCONF)) == RTF_GATEWAY;
-}
-
 static struct fib6_info *
 mlxsw_sp_fib6_entry_rt(const struct mlxsw_sp_fib6_entry *fib6_entry)
 {
@@ -4771,11 +4765,11 @@ mlxsw_sp_fib6_entry_rt(const struct mlxsw_sp_fib6_entry *fib6_entry)
 
 static struct mlxsw_sp_fib6_entry *
 mlxsw_sp_fib6_node_mp_entry_find(const struct mlxsw_sp_fib_node *fib_node,
-				 const struct fib6_info *nrt, bool replace)
+				 const struct fib6_info *nrt, bool append)
 {
 	struct mlxsw_sp_fib6_entry *fib6_entry;
 
-	if (!mlxsw_sp_fib6_rt_can_mp(nrt) || replace)
+	if (!append)
 		return NULL;
 
 	list_for_each_entry(fib6_entry, &fib_node->entry_list, common.list) {
@@ -4790,8 +4784,7 @@ mlxsw_sp_fib6_node_mp_entry_find(const struct mlxsw_sp_fib_node *fib_node,
 			break;
 		if (rt->fib6_metric < nrt->fib6_metric)
 			continue;
-		if (rt->fib6_metric == nrt->fib6_metric &&
-		    mlxsw_sp_fib6_rt_can_mp(rt))
+		if (rt->fib6_metric == nrt->fib6_metric)
 			return fib6_entry;
 		if (rt->fib6_metric > nrt->fib6_metric)
 			break;
@@ -5170,7 +5163,7 @@ static struct mlxsw_sp_fib6_entry *
 mlxsw_sp_fib6_node_entry_find(const struct mlxsw_sp_fib_node *fib_node,
 			      const struct fib6_info *nrt, bool replace)
 {
-	struct mlxsw_sp_fib6_entry *fib6_entry, *fallback = NULL;
+	struct mlxsw_sp_fib6_entry *fib6_entry;
 
 	list_for_each_entry(fib6_entry, &fib_node->entry_list, common.list) {
 		struct fib6_info *rt = mlxsw_sp_fib6_entry_rt(fib6_entry);
@@ -5179,18 +5172,13 @@ mlxsw_sp_fib6_node_entry_find(const struct mlxsw_sp_fib_node *fib_node,
 			continue;
 		if (rt->fib6_table->tb6_id != nrt->fib6_table->tb6_id)
 			break;
-		if (replace && rt->fib6_metric == nrt->fib6_metric) {
-			if (mlxsw_sp_fib6_rt_can_mp(rt) ==
-			    mlxsw_sp_fib6_rt_can_mp(nrt))
-				return fib6_entry;
-			if (mlxsw_sp_fib6_rt_can_mp(nrt))
-				fallback = fallback ?: fib6_entry;
-		}
+		if (replace && rt->fib6_metric == nrt->fib6_metric)
+			return fib6_entry;
 		if (rt->fib6_metric > nrt->fib6_metric)
-			return fallback ?: fib6_entry;
+			return fib6_entry;
 	}
 
-	return fallback;
+	return NULL;
 }
 
 static int
@@ -5316,7 +5304,8 @@ static void mlxsw_sp_fib6_entry_replace(struct mlxsw_sp *mlxsw_sp,
 }
 
 static int mlxsw_sp_router_fib6_add(struct mlxsw_sp *mlxsw_sp,
-				    struct fib6_info *rt, bool replace)
+				    struct fib6_info *rt, bool replace,
+				    bool append)
 {
 	struct mlxsw_sp_fib6_entry *fib6_entry;
 	struct mlxsw_sp_fib_node *fib_node;
@@ -5342,7 +5331,7 @@ static int mlxsw_sp_router_fib6_add(struct mlxsw_sp *mlxsw_sp,
 	/* Before creating a new entry, try to append route to an existing
 	 * multipath entry.
 	 */
-	fib6_entry = mlxsw_sp_fib6_node_mp_entry_find(fib_node, rt, replace);
+	fib6_entry = mlxsw_sp_fib6_node_mp_entry_find(fib_node, rt, append);
 	if (fib6_entry) {
 		err = mlxsw_sp_fib6_entry_nexthop_add(mlxsw_sp, fib6_entry, rt);
 		if (err)
@@ -5350,6 +5339,14 @@ static int mlxsw_sp_router_fib6_add(struct mlxsw_sp *mlxsw_sp,
 		return 0;
 	}
 
+	/* We received an append event, yet did not find any route to
+	 * append to.
+	 */
+	if (WARN_ON(append)) {
+		err = -EINVAL;
+		goto err_fib6_entry_append;
+	}
+
 	fib6_entry = mlxsw_sp_fib6_entry_create(mlxsw_sp, fib_node, rt);
 	if (IS_ERR(fib6_entry)) {
 		err = PTR_ERR(fib6_entry);
@@ -5367,6 +5364,7 @@ static int mlxsw_sp_router_fib6_add(struct mlxsw_sp *mlxsw_sp,
 err_fib6_node_entry_link:
 	mlxsw_sp_fib6_entry_destroy(mlxsw_sp, fib6_entry);
 err_fib6_entry_create:
+err_fib6_entry_append:
 err_fib6_entry_nexthop_add:
 	mlxsw_sp_fib_node_put(mlxsw_sp, fib_node);
 	return err;
@@ -5717,7 +5715,7 @@ static void mlxsw_sp_router_fib6_event_work(struct work_struct *work)
 	struct mlxsw_sp_fib_event_work *fib_work =
 		container_of(work, struct mlxsw_sp_fib_event_work, work);
 	struct mlxsw_sp *mlxsw_sp = fib_work->mlxsw_sp;
-	bool replace;
+	bool replace, append;
 	int err;
 
 	rtnl_lock();
@@ -5728,8 +5726,10 @@ static void mlxsw_sp_router_fib6_event_work(struct work_struct *work)
 	case FIB_EVENT_ENTRY_APPEND: /* fall through */
 	case FIB_EVENT_ENTRY_ADD:
 		replace = fib_work->event == FIB_EVENT_ENTRY_REPLACE;
+		append = fib_work->event == FIB_EVENT_ENTRY_APPEND;
 		err = mlxsw_sp_router_fib6_add(mlxsw_sp,
-					       fib_work->fen6_info.rt, replace);
+					       fib_work->fen6_info.rt, replace,
+					       append);
 		if (err)
 			mlxsw_sp_router_fib_abort(mlxsw_sp);
 		mlxsw_sp_rt6_release(fib_work->fen6_info.rt);

drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c

@@ -1018,8 +1018,10 @@ mlxsw_sp_port_vlan_bridge_join(struct mlxsw_sp_port_vlan *mlxsw_sp_port_vlan,
 	int err;
 
 	/* No need to continue if only VLAN flags were changed */
-	if (mlxsw_sp_port_vlan->bridge_port)
+	if (mlxsw_sp_port_vlan->bridge_port) {
+		mlxsw_sp_port_vlan_put(mlxsw_sp_port_vlan);
 		return 0;
+	}
 
 	err = mlxsw_sp_port_vlan_fid_join(mlxsw_sp_port_vlan, bridge_port);
 	if (err)

net/ipv6/ip6_fib.c

@@ -934,6 +934,7 @@ static int fib6_add_rt2node(struct fib6_node *fn, struct fib6_info *rt,
 {
 	struct fib6_info *leaf = rcu_dereference_protected(fn->leaf,
 				    lockdep_is_held(&rt->fib6_table->tb6_lock));
+	enum fib_event_type event = FIB_EVENT_ENTRY_ADD;
 	struct fib6_info *iter = NULL, *match = NULL;
 	struct fib6_info __rcu **ins;
 	int replace = (info->nlh &&
@@ -1013,6 +1014,7 @@ static int fib6_add_rt2node(struct fib6_node *fn, struct fib6_info *rt,
 				       "Can not append to a REJECT route");
 			return -EINVAL;
 		}
+		event = FIB_EVENT_ENTRY_APPEND;
 		rt->fib6_nsiblings = match->fib6_nsiblings;
 		list_add_tail(&rt->fib6_siblings, &match->fib6_siblings);
 		match->fib6_nsiblings++;
@@ -1034,15 +1036,12 @@ static int fib6_add_rt2node(struct fib6_node *fn, struct fib6_info *rt,
 	 *	insert node
 	 */
 	if (!replace) {
-		enum fib_event_type event;
-
 		if (!add)
 			pr_warn("NLM_F_CREATE should be set when creating new route\n");
 
 add:
 		nlflags |= NLM_F_CREATE;
 
-		event = append ? FIB_EVENT_ENTRY_APPEND : FIB_EVENT_ENTRY_ADD;
 		err = call_fib6_entry_notifiers(info->nl_net, event, rt,
 						extack);
 		if (err)