net: fib_notifier: make FIB notifier per-netns

Currently all users of FIB notifier only cares about events in init_net.
Later in this patchset, users get interested in other namespaces too.
However, for every registered block user is interested only about one
namespace. Make the FIB notifier registration per-netns and avoid
unnecessary calls of notifier block for other namespaces.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlx5/core/lag_mp.c

@@ -248,9 +248,6 @@ static int mlx5_lag_fib_event(struct notifier_block *nb,
 	struct net_device *fib_dev;
 	struct fib_info *fi;
 
-	if (!net_eq(info->net, &init_net))
-		return NOTIFY_DONE;
-
 	if (info->family != AF_INET)
 		return NOTIFY_DONE;
 
@@ -311,7 +308,7 @@ int mlx5_lag_mp_init(struct mlx5_lag *ldev)
 		return 0;
 
 	mp->fib_nb.notifier_call = mlx5_lag_fib_event;
-	err = register_fib_notifier(&mp->fib_nb,
+	err = register_fib_notifier(&init_net, &mp->fib_nb,
 				    mlx5_lag_fib_event_flush);
 	if (err)
 		mp->fib_nb.notifier_call = NULL;
@@ -326,6 +323,6 @@ void mlx5_lag_mp_cleanup(struct mlx5_lag *ldev)
 	if (!mp->fib_nb.notifier_call)
 		return;
 
-	unregister_fib_notifier(&mp->fib_nb);
+	unregister_fib_notifier(&init_net, &mp->fib_nb);
 	mp->fib_nb.notifier_call = NULL;
 }

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

@@ -6213,7 +6213,7 @@ static int mlxsw_sp_router_fib_rule_event(unsigned long event,
 	rule = fr_info->rule;
 
 	/* Rule only affects locally generated traffic */
-	if (rule->iifindex == info->net->loopback_dev->ifindex)
+	if (rule->iifindex == init_net.loopback_dev->ifindex)
 		return 0;
 
 	switch (info->family) {
@@ -6250,8 +6250,7 @@ static int mlxsw_sp_router_fib_event(struct notifier_block *nb,
 	struct mlxsw_sp_router *router;
 	int err;
 
-	if (!net_eq(info->net, &init_net) ||
-	    (info->family != AF_INET && info->family != AF_INET6 &&
+	if ((info->family != AF_INET && info->family != AF_INET6 &&
 	     info->family != RTNL_FAMILY_IPMR &&
 	     info->family != RTNL_FAMILY_IP6MR))
 		return NOTIFY_DONE;
@@ -8155,7 +8154,7 @@ int mlxsw_sp_router_init(struct mlxsw_sp *mlxsw_sp)
 		goto err_dscp_init;
 
 	mlxsw_sp->router->fib_nb.notifier_call = mlxsw_sp_router_fib_event;
-	err = register_fib_notifier(&mlxsw_sp->router->fib_nb,
+	err = register_fib_notifier(&init_net, &mlxsw_sp->router->fib_nb,
 				    mlxsw_sp_router_fib_dump_flush);
 	if (err)
 		goto err_register_fib_notifier;
@@ -8195,7 +8194,7 @@ int mlxsw_sp_router_init(struct mlxsw_sp *mlxsw_sp)
 
 void mlxsw_sp_router_fini(struct mlxsw_sp *mlxsw_sp)
 {
-	unregister_fib_notifier(&mlxsw_sp->router->fib_nb);
+	unregister_fib_notifier(&init_net, &mlxsw_sp->router->fib_nb);
 	unregister_netevent_notifier(&mlxsw_sp->router->netevent_nb);
 	mlxsw_sp_neigh_fini(mlxsw_sp);
 	mlxsw_sp_vrs_fini(mlxsw_sp);

drivers/net/ethernet/rocker/rocker_main.c

@@ -2189,9 +2189,6 @@ static int rocker_router_fib_event(struct notifier_block *nb,
 	struct rocker_fib_event_work *fib_work;
 	struct fib_notifier_info *info = ptr;
 
-	if (!net_eq(info->net, &init_net))
-		return NOTIFY_DONE;
-
 	if (info->family != AF_INET)
 		return NOTIFY_DONE;
 
@@ -2994,7 +2991,7 @@ static int rocker_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	 * the device, so no need to pass a callback.
 	 */
 	rocker->fib_nb.notifier_call = rocker_router_fib_event;
-	err = register_fib_notifier(&rocker->fib_nb, NULL);
+	err = register_fib_notifier(&init_net, &rocker->fib_nb, NULL);
 	if (err)
 		goto err_register_fib_notifier;
 
@@ -3021,7 +3018,7 @@ static int rocker_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 err_register_switchdev_blocking_notifier:
 	unregister_switchdev_notifier(&rocker_switchdev_notifier);
 err_register_switchdev_notifier:
-	unregister_fib_notifier(&rocker->fib_nb);
+	unregister_fib_notifier(&init_net, &rocker->fib_nb);
 err_register_fib_notifier:
 	rocker_remove_ports(rocker);
 err_probe_ports:
@@ -3057,7 +3054,7 @@ static void rocker_remove(struct pci_dev *pdev)
 	unregister_switchdev_blocking_notifier(nb);
 
 	unregister_switchdev_notifier(&rocker_switchdev_notifier);
-	unregister_fib_notifier(&rocker->fib_nb);
+	unregister_fib_notifier(&init_net, &rocker->fib_nb);
 	rocker_remove_ports(rocker);
 	rocker_write32(rocker, CONTROL, ROCKER_CONTROL_RESET);
 	destroy_workqueue(rocker->rocker_owq);

drivers/net/netdevsim/fib.c

@@ -182,9 +182,6 @@ static int nsim_fib_event_nb(struct notifier_block *nb, unsigned long event,
 	struct fib_notifier_info *info = ptr;
 	int err = 0;
 
-	if (!net_eq(info->net, &init_net))
-		return NOTIFY_DONE;
-
 	switch (event) {
 	case FIB_EVENT_RULE_ADD: /* fall through */
 	case FIB_EVENT_RULE_DEL:
@@ -258,7 +255,8 @@ struct nsim_fib_data *nsim_fib_create(struct devlink *devlink)
 	data->ipv6.rules.max = (u64)-1;
 
 	data->fib_nb.notifier_call = nsim_fib_event_nb;
-	err = register_fib_notifier(&data->fib_nb, nsim_fib_dump_inconsistent);
+	err = register_fib_notifier(&init_net, &data->fib_nb,
+				    nsim_fib_dump_inconsistent);
 	if (err) {
 		pr_err("Failed to register fib notifier\n");
 		goto err_out;
@@ -297,6 +295,6 @@ void nsim_fib_destroy(struct devlink *devlink, struct nsim_fib_data *data)
 					    NSIM_RESOURCE_IPV4_FIB_RULES);
 	devlink_resource_occ_get_unregister(devlink,
 					    NSIM_RESOURCE_IPV4_FIB);
-	unregister_fib_notifier(&data->fib_nb);
+	unregister_fib_notifier(&init_net, &data->fib_nb);
 	kfree(data);
 }

include/linux/mroute_base.h

@@ -47,7 +47,6 @@ struct vif_entry_notifier_info {
 };
 
 static inline int mr_call_vif_notifier(struct notifier_block *nb,
-				       struct net *net,
 				       unsigned short family,
 				       enum fib_event_type event_type,
 				       struct vif_device *vif,
@@ -56,7 +55,6 @@ static inline int mr_call_vif_notifier(struct notifier_block *nb,
 	struct vif_entry_notifier_info info = {
 		.info = {
 			.family = family,
-			.net = net,
 		},
 		.dev = vif->dev,
 		.vif_index = vif_index,
@@ -64,7 +62,7 @@ static inline int mr_call_vif_notifier(struct notifier_block *nb,
 		.tb_id = tb_id,
 	};
 
-	return call_fib_notifier(nb, net, event_type, &info.info);
+	return call_fib_notifier(nb, event_type, &info.info);
 }
 
 static inline int mr_call_vif_notifiers(struct net *net,
@@ -77,7 +75,6 @@ static inline int mr_call_vif_notifiers(struct net *net,
 	struct vif_entry_notifier_info info = {
 		.info = {
 			.family = family,
-			.net = net,
 		},
 		.dev = vif->dev,
 		.vif_index = vif_index,
@@ -173,7 +170,6 @@ struct mfc_entry_notifier_info {
 };
 
 static inline int mr_call_mfc_notifier(struct notifier_block *nb,
-				       struct net *net,
 				       unsigned short family,
 				       enum fib_event_type event_type,
 				       struct mr_mfc *mfc, u32 tb_id)
@@ -181,13 +177,12 @@ static inline int mr_call_mfc_notifier(struct notifier_block *nb,
 	struct mfc_entry_notifier_info info = {
 		.info = {
 			.family = family,
-			.net = net,
 		},
 		.mfc = mfc,
 		.tb_id = tb_id
 	};
 
-	return call_fib_notifier(nb, net, event_type, &info.info);
+	return call_fib_notifier(nb, event_type, &info.info);
 }
 
 static inline int mr_call_mfc_notifiers(struct net *net,
@@ -199,7 +194,6 @@ static inline int mr_call_mfc_notifiers(struct net *net,
 	struct mfc_entry_notifier_info info = {
 		.info = {
 			.family = family,
-			.net = net,
 		},
 		.mfc = mfc,
 		.tb_id = tb_id

include/net/fib_notifier.h

@@ -8,7 +8,6 @@
 struct module;
 
 struct fib_notifier_info {
-	struct net *net;
 	int family;
 	struct netlink_ext_ack  *extack;
 };
@@ -35,14 +34,14 @@ struct fib_notifier_ops {
 	struct rcu_head rcu;
 };
 
-int call_fib_notifier(struct notifier_block *nb, struct net *net,
+int call_fib_notifier(struct notifier_block *nb,
 		      enum fib_event_type event_type,
 		      struct fib_notifier_info *info);
 int call_fib_notifiers(struct net *net, enum fib_event_type event_type,
 		       struct fib_notifier_info *info);
-int register_fib_notifier(struct notifier_block *nb,
+int register_fib_notifier(struct net *net, struct notifier_block *nb,
 			  void (*cb)(struct notifier_block *nb));
-int unregister_fib_notifier(struct notifier_block *nb);
+int unregister_fib_notifier(struct net *net, struct notifier_block *nb);
 struct fib_notifier_ops *
 fib_notifier_ops_register(const struct fib_notifier_ops *tmpl, struct net *net);
 void fib_notifier_ops_unregister(struct fib_notifier_ops *ops);

include/net/ip6_fib.h

@@ -478,7 +478,7 @@ struct ipv6_route_iter {
 
 extern const struct seq_operations ipv6_route_seq_ops;
 
-int call_fib6_notifier(struct notifier_block *nb, struct net *net,
+int call_fib6_notifier(struct notifier_block *nb,
 		       enum fib_event_type event_type,
 		       struct fib_notifier_info *info);
 int call_fib6_notifiers(struct net *net, enum fib_event_type event_type,

include/net/ip_fib.h

@@ -219,7 +219,7 @@ struct fib_nh_notifier_info {
 	struct fib_nh *fib_nh;
 };
 
-int call_fib4_notifier(struct notifier_block *nb, struct net *net,
+int call_fib4_notifier(struct notifier_block *nb,
 		       enum fib_event_type event_type,
 		       struct fib_notifier_info *info);
 int call_fib4_notifiers(struct net *net, enum fib_event_type event_type,

net/core/fib_notifier.c

@@ -12,17 +12,15 @@ static unsigned int fib_notifier_net_id;
 
 struct fib_notifier_net {
 	struct list_head fib_notifier_ops;
+	struct atomic_notifier_head fib_chain;
 };
 
-static ATOMIC_NOTIFIER_HEAD(fib_chain);
-
-int call_fib_notifier(struct notifier_block *nb, struct net *net,
+int call_fib_notifier(struct notifier_block *nb,
 		      enum fib_event_type event_type,
 		      struct fib_notifier_info *info)
 {
 	int err;
 
-	info->net = net;
 	err = nb->notifier_call(nb, event_type, info);
 	return notifier_to_errno(err);
 }
@@ -31,25 +29,21 @@ EXPORT_SYMBOL(call_fib_notifier);
 int call_fib_notifiers(struct net *net, enum fib_event_type event_type,
 		       struct fib_notifier_info *info)
 {
+	struct fib_notifier_net *fn_net = net_generic(net, fib_notifier_net_id);
 	int err;
 
-	info->net = net;
-	err = atomic_notifier_call_chain(&fib_chain, event_type, info);
+	err = atomic_notifier_call_chain(&fn_net->fib_chain, event_type, info);
 	return notifier_to_errno(err);
 }
 EXPORT_SYMBOL(call_fib_notifiers);
 
-static unsigned int fib_seq_sum(void)
+static unsigned int fib_seq_sum(struct net *net)
 {
-	struct fib_notifier_net *fn_net;
+	struct fib_notifier_net *fn_net = net_generic(net, fib_notifier_net_id);
 	struct fib_notifier_ops *ops;
 	unsigned int fib_seq = 0;
-	struct net *net;
 
 	rtnl_lock();
-	down_read(&net_rwsem);
-	for_each_net(net) {
-		fn_net = net_generic(net, fib_notifier_net_id);
 	rcu_read_lock();
 	list_for_each_entry_rcu(ops, &fn_net->fib_notifier_ops, list) {
 		if (!try_module_get(ops->owner))
@@ -58,8 +52,6 @@ static unsigned int fib_seq_sum(void)
 		module_put(ops->owner);
 	}
 	rcu_read_unlock();
-	}
-	up_read(&net_rwsem);
 	rtnl_unlock();
 
 	return fib_seq;
@@ -69,68 +61,66 @@ static int fib_net_dump(struct net *net, struct notifier_block *nb)
 {
 	struct fib_notifier_net *fn_net = net_generic(net, fib_notifier_net_id);
 	struct fib_notifier_ops *ops;
+	int err = 0;
 
+	rcu_read_lock();
 	list_for_each_entry_rcu(ops, &fn_net->fib_notifier_ops, list) {
-		int err;
-
 		if (!try_module_get(ops->owner))
 			continue;
 		err = ops->fib_dump(net, nb);
 		module_put(ops->owner);
 		if (err)
-			return err;
+			goto unlock;
 	}
 
-	return 0;
+unlock:
+	rcu_read_unlock();
+
+	return err;
 }
 
-static bool fib_dump_is_consistent(struct notifier_block *nb,
+static bool fib_dump_is_consistent(struct net *net, struct notifier_block *nb,
 				   void (*cb)(struct notifier_block *nb),
 				   unsigned int fib_seq)
 {
-	atomic_notifier_chain_register(&fib_chain, nb);
-	if (fib_seq == fib_seq_sum())
+	struct fib_notifier_net *fn_net = net_generic(net, fib_notifier_net_id);
+
+	atomic_notifier_chain_register(&fn_net->fib_chain, nb);
+	if (fib_seq == fib_seq_sum(net))
 		return true;
-	atomic_notifier_chain_unregister(&fib_chain, nb);
+	atomic_notifier_chain_unregister(&fn_net->fib_chain, nb);
 	if (cb)
 		cb(nb);
 	return false;
 }
 
 #define FIB_DUMP_MAX_RETRIES 5
-int register_fib_notifier(struct notifier_block *nb,
+int register_fib_notifier(struct net *net, struct notifier_block *nb,
 			  void (*cb)(struct notifier_block *nb))
 {
 	int retries = 0;
 	int err;
 
 	do {
-		unsigned int fib_seq = fib_seq_sum();
-		struct net *net;
+		unsigned int fib_seq = fib_seq_sum(net);
 
-		rcu_read_lock();
-		for_each_net_rcu(net) {
 		err = fib_net_dump(net, nb);
 		if (err)
-				goto err_fib_net_dump;
-		}
-		rcu_read_unlock();
+			return err;
 
-		if (fib_dump_is_consistent(nb, cb, fib_seq))
+		if (fib_dump_is_consistent(net, nb, cb, fib_seq))
 			return 0;
 	} while (++retries < FIB_DUMP_MAX_RETRIES);
 
 	return -EBUSY;
-
-err_fib_net_dump:
-	rcu_read_unlock();
-	return err;
 }
 EXPORT_SYMBOL(register_fib_notifier);
 
-int unregister_fib_notifier(struct notifier_block *nb)
+int unregister_fib_notifier(struct net *net, struct notifier_block *nb)
 {
-	return atomic_notifier_chain_unregister(&fib_chain, nb);
+	struct fib_notifier_net *fn_net = net_generic(net, fib_notifier_net_id);
+
+	return atomic_notifier_chain_unregister(&fn_net->fib_chain, nb);
 }
 EXPORT_SYMBOL(unregister_fib_notifier);
 
@@ -181,6 +171,7 @@ static int __net_init fib_notifier_net_init(struct net *net)
 	struct fib_notifier_net *fn_net = net_generic(net, fib_notifier_net_id);
 
 	INIT_LIST_HEAD(&fn_net->fib_notifier_ops);
+	ATOMIC_INIT_NOTIFIER_HEAD(&fn_net->fib_chain);
 	return 0;
 }
 

net/core/fib_rules.c

@@ -321,7 +321,7 @@ int fib_rules_lookup(struct fib_rules_ops *ops, struct flowi *fl,
 }
 EXPORT_SYMBOL_GPL(fib_rules_lookup);
 
-static int call_fib_rule_notifier(struct notifier_block *nb, struct net *net,
+static int call_fib_rule_notifier(struct notifier_block *nb,
 				  enum fib_event_type event_type,
 				  struct fib_rule *rule, int family)
 {
@@ -330,7 +330,7 @@ static int call_fib_rule_notifier(struct notifier_block *nb, struct net *net,
 		.rule = rule,
 	};
 
-	return call_fib_notifier(nb, net, event_type, &info.info);
+	return call_fib_notifier(nb, event_type, &info.info);
 }
 
 static int call_fib_rule_notifiers(struct net *net,
@@ -359,8 +359,7 @@ int fib_rules_dump(struct net *net, struct notifier_block *nb, int family)
 	if (!ops)
 		return -EAFNOSUPPORT;
 	list_for_each_entry_rcu(rule, &ops->rules_list, list)
-		call_fib_rule_notifier(nb, net, FIB_EVENT_RULE_ADD, rule,
-				       family);
+		call_fib_rule_notifier(nb, FIB_EVENT_RULE_ADD, rule, family);
 	rules_ops_put(ops);
 
 	return 0;

net/ipv4/fib_notifier.c

@@ -9,12 +9,12 @@
 #include <net/netns/ipv4.h>
 #include <net/ip_fib.h>
 
-int call_fib4_notifier(struct notifier_block *nb, struct net *net,
+int call_fib4_notifier(struct notifier_block *nb,
 		       enum fib_event_type event_type,
 		       struct fib_notifier_info *info)
 {
 	info->family = AF_INET;
-	return call_fib_notifier(nb, net, event_type, info);
+	return call_fib_notifier(nb, event_type, info);
 }
 
 int call_fib4_notifiers(struct net *net, enum fib_event_type event_type,

net/ipv4/fib_trie.c

@@ -74,7 +74,7 @@
 #include <trace/events/fib.h>
 #include "fib_lookup.h"
 
-static int call_fib_entry_notifier(struct notifier_block *nb, struct net *net,
+static int call_fib_entry_notifier(struct notifier_block *nb,
 				   enum fib_event_type event_type, u32 dst,
 				   int dst_len, struct fib_alias *fa)
 {
@@ -86,7 +86,7 @@ static int call_fib_entry_notifier(struct notifier_block *nb, struct net *net,
 		.type = fa->fa_type,
 		.tb_id = fa->tb_id,
 	};
-	return call_fib4_notifier(nb, net, event_type, &info.info);
+	return call_fib4_notifier(nb, event_type, &info.info);
 }
 
 static int call_fib_entry_notifiers(struct net *net,
@@ -2015,8 +2015,8 @@ void fib_info_notify_update(struct net *net, struct nl_info *info)
 	}
 }
 
-static void fib_leaf_notify(struct net *net, struct key_vector *l,
-			    struct fib_table *tb, struct notifier_block *nb)
+static void fib_leaf_notify(struct key_vector *l, struct fib_table *tb,
+			    struct notifier_block *nb)
 {
 	struct fib_alias *fa;
 
@@ -2032,20 +2032,19 @@ static void fib_leaf_notify(struct net *net, struct key_vector *l,
 		if (tb->tb_id != fa->tb_id)
 			continue;
 
-		call_fib_entry_notifier(nb, net, FIB_EVENT_ENTRY_ADD, l->key,
+		call_fib_entry_notifier(nb, FIB_EVENT_ENTRY_ADD, l->key,
 					KEYLENGTH - fa->fa_slen, fa);
 	}
 }
 
-static void fib_table_notify(struct net *net, struct fib_table *tb,
-			     struct notifier_block *nb)
+static void fib_table_notify(struct fib_table *tb, struct notifier_block *nb)
 {
 	struct trie *t = (struct trie *)tb->tb_data;
 	struct key_vector *l, *tp = t->kv;
 	t_key key = 0;
 
 	while ((l = leaf_walk_rcu(&tp, key)) != NULL) {
-		fib_leaf_notify(net, l, tb, nb);
+		fib_leaf_notify(l, tb, nb);
 
 		key = l->key + 1;
 		/* stop in case of wrap around */
@@ -2063,7 +2062,7 @@ void fib_notify(struct net *net, struct notifier_block *nb)
 		struct fib_table *tb;
 
 		hlist_for_each_entry_rcu(tb, head, tb_hlist)
-			fib_table_notify(net, tb, nb);
+			fib_table_notify(tb, nb);
 	}
 }
 

net/ipv4/ipmr_base.c

@@ -409,7 +409,7 @@ int mr_dump(struct net *net, struct notifier_block *nb, unsigned short family,
 			if (!v->dev)
 				continue;
 
-			mr_call_vif_notifier(nb, net, family,
+			mr_call_vif_notifier(nb, family,
 					     FIB_EVENT_VIF_ADD,
 					     v, vifi, mrt->id);
 		}
@@ -417,7 +417,7 @@ int mr_dump(struct net *net, struct notifier_block *nb, unsigned short family,
 
 		/* Notify on table MFC entries */
 		list_for_each_entry_rcu(mfc, &mrt->mfc_cache_list, list)
-			mr_call_mfc_notifier(nb, net, family,
+			mr_call_mfc_notifier(nb, family,
 					     FIB_EVENT_ENTRY_ADD,
 					     mfc, mrt->id);
 	}

net/ipv6/fib6_notifier.c

@@ -7,12 +7,12 @@
 #include <net/netns/ipv6.h>
 #include <net/ip6_fib.h>
 
-int call_fib6_notifier(struct notifier_block *nb, struct net *net,
+int call_fib6_notifier(struct notifier_block *nb,
 		       enum fib_event_type event_type,
 		       struct fib_notifier_info *info)
 {
 	info->family = AF_INET6;
-	return call_fib_notifier(nb, net, event_type, info);
+	return call_fib_notifier(nb, event_type, info);
 }
 
 int call_fib6_notifiers(struct net *net, enum fib_event_type event_type,

net/ipv6/ip6_fib.c

@@ -357,7 +357,7 @@ unsigned int fib6_tables_seq_read(struct net *net)
 	return fib_seq;
 }
 
-static int call_fib6_entry_notifier(struct notifier_block *nb, struct net *net,
+static int call_fib6_entry_notifier(struct notifier_block *nb,
 				    enum fib_event_type event_type,
 				    struct fib6_info *rt)
 {
@@ -365,7 +365,7 @@ static int call_fib6_entry_notifier(struct notifier_block *nb, struct net *net,
 		.rt = rt,
 	};
 
-	return call_fib6_notifier(nb, net, event_type, &info.info);
+	return call_fib6_notifier(nb, event_type, &info.info);
 }
 
 int call_fib6_entry_notifiers(struct net *net,
@@ -407,7 +407,7 @@ static void fib6_rt_dump(struct fib6_info *rt, struct fib6_dump_arg *arg)
 {
 	if (rt == arg->net->ipv6.fib6_null_entry)
 		return;
-	call_fib6_entry_notifier(arg->nb, arg->net, FIB_EVENT_ENTRY_ADD, rt);
+	call_fib6_entry_notifier(arg->nb, FIB_EVENT_ENTRY_ADD, rt);
 }
 
 static int fib6_node_dump(struct fib6_walker *w)