Merge branch 'mlxsw-extack'

David Ahern says:

====================
mlxsw: spectrum_router: Add extack messages for RIF and VRF overflow

Currently, exceeding the number of VRF instances or the number of router
interfaces either fails with a non-intuitive EBUSY:
    $ ip li set swp1s1.6 vrf vrf-1s1-6 up
    RTNETLINK answers: Device or resource busy

or fails silently (IPv6) since the checks are done in a work queue. This
set adds support for the address validator notifier to spectrum which
allows ext-ack based messages to be returned on failure.

To make that happen the IPv6 version needs to be converted from atomic
to blocking (patch 2), and then support for extack needs to be added
to the notifier (patch 3). Patch 1 reworks the locking in ipv6_add_addr
to work better in the atomic and non-atomic code paths. Patches 4 and 5
add the validator notifier to spectrum and then plumb the extack argument
through spectrum_router.

With this set, VRF overflows fail with:
   $ ip li set swp1s1.6 vrf vrf-1s1-6 up
   Error: spectrum: Exceeded number of supported VRF.

and RIF overflows fail with:
   $ ip addr add dev swp1s2.191 10.12.191.1/24
   Error: spectrum: Exceeded number of supported router interfaces.

v2 -> v3
- fix surround context of patch 4 which was altered by c30f5d0

v1 -> v2
- fix error path in ipv6_add_addr: reset rt to NULL (Ido comment) and
  add in6_dev_put on ifa once the hold has been done

RFC -> v1
- addressed various comments from Ido
- refactored ipv6_add_addr to allow ifa's to be allocated with
  GFP_KERNEL as requested by DaveM
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

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

@@ -4521,9 +4521,16 @@ static int mlxsw_sp_netdevice_event(struct notifier_block *nb,
 	return notifier_from_errno(err);
 }
 
+static struct notifier_block mlxsw_sp_inetaddr_valid_nb __read_mostly = {
+	.notifier_call = mlxsw_sp_inetaddr_valid_event,
+};
+
 static struct notifier_block mlxsw_sp_inetaddr_nb __read_mostly = {
 	.notifier_call = mlxsw_sp_inetaddr_event,
-	.priority = 10,	/* Must be called before FIB notifier block */
+};
+
+static struct notifier_block mlxsw_sp_inet6addr_valid_nb __read_mostly = {
+	.notifier_call = mlxsw_sp_inet6addr_valid_event,
 };
 
 static struct notifier_block mlxsw_sp_inet6addr_nb __read_mostly = {
@@ -4548,7 +4555,9 @@ static int __init mlxsw_sp_module_init(void)
 {
 	int err;
 
+	register_inetaddr_validator_notifier(&mlxsw_sp_inetaddr_valid_nb);
 	register_inetaddr_notifier(&mlxsw_sp_inetaddr_nb);
+	register_inet6addr_validator_notifier(&mlxsw_sp_inet6addr_valid_nb);
 	register_inet6addr_notifier(&mlxsw_sp_inet6addr_nb);
 	register_netevent_notifier(&mlxsw_sp_router_netevent_nb);
 
@@ -4567,7 +4576,9 @@ static int __init mlxsw_sp_module_init(void)
 err_core_driver_register:
 	unregister_netevent_notifier(&mlxsw_sp_router_netevent_nb);
 	unregister_inet6addr_notifier(&mlxsw_sp_inet6addr_nb);
+	unregister_inet6addr_validator_notifier(&mlxsw_sp_inet6addr_valid_nb);
 	unregister_inetaddr_notifier(&mlxsw_sp_inetaddr_nb);
+	unregister_inetaddr_validator_notifier(&mlxsw_sp_inetaddr_valid_nb);
 	return err;
 }
 
@@ -4577,7 +4588,9 @@ static void __exit mlxsw_sp_module_exit(void)
 	mlxsw_core_driver_unregister(&mlxsw_sp_driver);
 	unregister_netevent_notifier(&mlxsw_sp_router_netevent_nb);
 	unregister_inet6addr_notifier(&mlxsw_sp_inet6addr_nb);
+	unregister_inet6addr_validator_notifier(&mlxsw_sp_inet6addr_valid_nb);
 	unregister_inetaddr_notifier(&mlxsw_sp_inetaddr_nb);
+	unregister_inetaddr_validator_notifier(&mlxsw_sp_inetaddr_valid_nb);
 }
 
 module_init(mlxsw_sp_module_init);

drivers/net/ethernet/mellanox/mlxsw/spectrum.h

@@ -391,8 +391,12 @@ int mlxsw_sp_router_netevent_event(struct notifier_block *unused,
 int mlxsw_sp_netdevice_router_port_event(struct net_device *dev);
 int mlxsw_sp_inetaddr_event(struct notifier_block *unused,
 			    unsigned long event, void *ptr);
+int mlxsw_sp_inetaddr_valid_event(struct notifier_block *unused,
+				  unsigned long event, void *ptr);
 int mlxsw_sp_inet6addr_event(struct notifier_block *unused,
 			     unsigned long event, void *ptr);
+int mlxsw_sp_inet6addr_valid_event(struct notifier_block *unused,
+				   unsigned long event, void *ptr);
 int mlxsw_sp_netdevice_vrf_event(struct net_device *l3_dev, unsigned long event,
 				 struct netdev_notifier_changeupper_info *info);
 bool mlxsw_sp_netdev_is_ipip(const struct mlxsw_sp *mlxsw_sp,