Merge branch 'Pass-extack-to-NETDEV_PRE_UP'

Petr Machata says:

====================
Pass extack to NETDEV_PRE_UP

Drivers may need to validate configuration of a device that's about to
be upped. An example is mlxsw, which needs to check the configuration of
a VXLAN device attached to an offloaded bridge. Should the validation
fail, there's currently no way to communicate details of the failure to
the user, beyond an error number.

Therefore this patch set extends the NETDEV_PRE_UP event to include
extack, if available.

There are three vectors through which NETDEV_PRE_UP invocation can be
reached. The two major ones are dev_open() and dev_change_flags(), the
last is then __dev_change_flags().

In patch #1, the first access vector, dev_open() is addressed. An extack
parameter is added and all users converted to use it.

Before addressing the second vector, two preparatory patches propagate
extack argument to the proximity of the dev_change_flags() call in VRF
and IPVLAN drivers. That happens in patches #2 and #3. Then in patch #4,
dev_change_flags() is treated similarly to dev_open().

Likewise in patch #5, __dev_change_flags() is extended.

Then in patches #6 and #7, the extack is finally propagated all the way
to the point where the notification is emitted.

This change allows particularly mlxsw (which already has code to
leverage extack if available) to communicate to the user error messages
regarding VXLAN configuration. In patch #8, add a test case that
exercises this code and checks that an error message is propagated.

For example:

	local 192.0.2.17 remote 192.0.2.18 \
	dstport 4789 nolearning noudpcsum tos inherit ttl 100
	local 192.0.2.17 remote 192.0.2.18 \
	dstport 4789 nolearning noudpcsum tos inherit ttl 100
Error: mlxsw_spectrum: Conflicting NVE tunnels configuration.

v2:
- Add David Ahern's tags.
====================

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

14 files changed, 35 insertions, 29 deletions

diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 333387f1f1fe..6b34dbefa7dd 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -1538,7 +1538,7 @@ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev,
 	slave_dev->flags |= IFF_SLAVE;
 
 	/* open the slave since the application closed it */
-	res = dev_open(slave_dev);
+	res = dev_open(slave_dev, extack);
 	if (res) {
 		netdev_dbg(bond_dev, "Opening slave %s failed\n", slave_dev->name);
 		goto err_restore_mac;
diff --git a/drivers/net/ethernet/aquantia/atlantic/aq_ethtool.c b/drivers/net/ethernet/aquantia/atlantic/aq_ethtool.c
index a5fd71692c8b..43b42615ad84 100644
--- a/drivers/net/ethernet/aquantia/atlantic/aq_ethtool.c
+++ b/drivers/net/ethernet/aquantia/atlantic/aq_ethtool.c
@@ -525,7 +525,7 @@ static int aq_set_ringparam(struct net_device *ndev,
 		}
 	}
 	if (ndev_running)
-		err = dev_open(ndev);
+		err = dev_open(ndev, NULL);
 
 err_exit:
 	return err;
diff --git a/drivers/net/ethernet/cisco/enic/enic_ethtool.c b/drivers/net/ethernet/cisco/enic/enic_ethtool.c
index f42f7a6e1559..ebd5c2cf1efe 100644
--- a/drivers/net/ethernet/cisco/enic/enic_ethtool.c
+++ b/drivers/net/ethernet/cisco/enic/enic_ethtool.c
@@ -241,7 +241,7 @@ static int enic_set_ringparam(struct net_device *netdev,
 	}
 	enic_init_vnic_resources(enic);
 	if (running) {
-		err = dev_open(netdev);
+		err = dev_open(netdev, NULL);
 		if (err)
 			goto err_out;
 	}
diff --git a/drivers/net/ethernet/hisilicon/hns/hns_ethtool.c b/drivers/net/ethernet/hisilicon/hns/hns_ethtool.c
index 774beda040a1..8e9b95871d30 100644
--- a/drivers/net/ethernet/hisilicon/hns/hns_ethtool.c
+++ b/drivers/net/ethernet/hisilicon/hns/hns_ethtool.c
@@ -624,7 +624,7 @@ static void hns_nic_self_test(struct net_device *ndev,
 		clear_bit(NIC_STATE_TESTING, &priv->state);
 
 		if (if_running)
-			(void)dev_open(ndev);
+			(void)dev_open(ndev, NULL);
 	}
 	/* Online tests aren't run; pass by default */
 
diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3_ethtool.c b/drivers/net/ethernet/hisilicon/hns3/hns3_ethtool.c
index 4563638367ac..e678b6939da3 100644
--- a/drivers/net/ethernet/hisilicon/hns3/hns3_ethtool.c
+++ b/drivers/net/ethernet/hisilicon/hns3/hns3_ethtool.c
@@ -821,7 +821,7 @@ static int hns3_set_ringparam(struct net_device *ndev,
 	}
 
 	if (if_running)
-		ret = dev_open(ndev);
+		ret = dev_open(ndev, NULL);
 
 	return ret;
 }
diff --git a/drivers/net/ethernet/sfc/ethtool.c b/drivers/net/ethernet/sfc/ethtool.c
index 3143588ffd77..600d7b895cf2 100644
--- a/drivers/net/ethernet/sfc/ethtool.c
+++ b/drivers/net/ethernet/sfc/ethtool.c
@@ -539,7 +539,7 @@ static void efx_ethtool_self_test(struct net_device *net_dev,
 	/* We need rx buffers and interrupts. */
 	already_up = (efx->net_dev->flags & IFF_UP);
 	if (!already_up) {
-		rc = dev_open(efx->net_dev);
+		rc = dev_open(efx->net_dev, NULL);
 		if (rc) {
 			netif_err(efx, drv, efx->net_dev,
 				  "failed opening device.\n");
diff --git a/drivers/net/ethernet/sfc/falcon/ethtool.c b/drivers/net/ethernet/sfc/falcon/ethtool.c
index 1ccdb7a82e2a..72cedec945c1 100644
--- a/drivers/net/ethernet/sfc/falcon/ethtool.c
+++ b/drivers/net/ethernet/sfc/falcon/ethtool.c
@@ -517,7 +517,7 @@ static void ef4_ethtool_self_test(struct net_device *net_dev,
 	/* We need rx buffers and interrupts. */
 	already_up = (efx->net_dev->flags & IFF_UP);
 	if (!already_up) {
-		rc = dev_open(efx->net_dev);
+		rc = dev_open(efx->net_dev, NULL);
 		if (rc) {
 			netif_err(efx, drv, efx->net_dev,
 				  "failed opening device.\n");
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index c728ed1375b2..d20496f0ebd0 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -4082,7 +4082,7 @@ static void stmmac_reset_subtask(struct stmmac_priv *priv)
 
 	set_bit(STMMAC_DOWN, &priv->state);
 	dev_close(priv->dev);
-	dev_open(priv->dev);
+	dev_open(priv->dev, NULL);
 	clear_bit(STMMAC_DOWN, &priv->state);
 	clear_bit(STMMAC_RESETING, &priv->state);
 	rtnl_unlock();
diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index 85936ed9e952..18b5584d6377 100644
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -137,7 +137,7 @@ static int netvsc_open(struct net_device *net)
 		 * slave as up. If open fails, then slave will be
 		 * still be offline (and not used).
 		 */
-		ret = dev_open(vf_netdev);
+		ret = dev_open(vf_netdev, NULL);
 		if (ret)
 			netdev_warn(net,
 				    "unable to open slave: %s: %d\n",
@@ -1993,7 +1993,7 @@ static void __netvsc_vf_setup(struct net_device *ndev,
 			    "unable to change mtu to %u\n", ndev->mtu);
 
 	/* set multicast etc flags on VF */
-	dev_change_flags(vf_netdev, ndev->flags | IFF_SLAVE);
+	dev_change_flags(vf_netdev, ndev->flags | IFF_SLAVE, NULL);
 
 	/* sync address list from ndev to VF */
 	netif_addr_lock_bh(ndev);
@@ -2002,7 +2002,7 @@ static void __netvsc_vf_setup(struct net_device *ndev,
 	netif_addr_unlock_bh(ndev);
 
 	if (netif_running(ndev)) {
-		ret = dev_open(vf_netdev);
+		ret = dev_open(vf_netdev, NULL);
 		if (ret)
 			netdev_warn(vf_netdev,
 				    "unable to open: %d\n", ret);
diff --git a/drivers/net/ipvlan/ipvlan_main.c b/drivers/net/ipvlan/ipvlan_main.c
index 4a949569ec4c..c3d3e458f541 100644
--- a/drivers/net/ipvlan/ipvlan_main.c
+++ b/drivers/net/ipvlan/ipvlan_main.c
@@ -71,7 +71,8 @@ static void ipvlan_unregister_nf_hook(struct net *net)
 					ARRAY_SIZE(ipvl_nfops));
 }
 
-static int ipvlan_set_port_mode(struct ipvl_port *port, u16 nval)
+static int ipvlan_set_port_mode(struct ipvl_port *port, u16 nval,
+				struct netlink_ext_ack *extack)
 {
 	struct ipvl_dev *ipvlan;
 	struct net_device *mdev = port->dev;
@@ -84,10 +85,12 @@ static int ipvlan_set_port_mode(struct ipvl_port *port, u16 nval)
 			flags = ipvlan->dev->flags;
 			if (nval == IPVLAN_MODE_L3 || nval == IPVLAN_MODE_L3S) {
 				err = dev_change_flags(ipvlan->dev,
-						       flags | IFF_NOARP);
+						       flags | IFF_NOARP,
+						       extack);
 			} else {
 				err = dev_change_flags(ipvlan->dev,
-						       flags & ~IFF_NOARP);
+						       flags & ~IFF_NOARP,
+						       extack);
 			}
 			if (unlikely(err))
 				goto fail;
@@ -116,9 +119,11 @@ fail:
 		flags = ipvlan->dev->flags;
 		if (port->mode == IPVLAN_MODE_L3 ||
 		    port->mode == IPVLAN_MODE_L3S)
-			dev_change_flags(ipvlan->dev, flags | IFF_NOARP);
+			dev_change_flags(ipvlan->dev, flags | IFF_NOARP,
+					 NULL);
 		else
-			dev_change_flags(ipvlan->dev, flags & ~IFF_NOARP);
+			dev_change_flags(ipvlan->dev, flags & ~IFF_NOARP,
+					 NULL);
 	}
 
 	return err;
@@ -498,7 +503,7 @@ static int ipvlan_nl_changelink(struct net_device *dev,
 	if (data[IFLA_IPVLAN_MODE]) {
 		u16 nmode = nla_get_u16(data[IFLA_IPVLAN_MODE]);
 
-		err = ipvlan_set_port_mode(port, nmode);
+		err = ipvlan_set_port_mode(port, nmode, extack);
 	}
 
 	if (!err && data[IFLA_IPVLAN_FLAGS]) {
@@ -672,7 +677,7 @@ int ipvlan_link_new(struct net *src_net, struct net_device *dev,
 	if (data && data[IFLA_IPVLAN_MODE])
 		mode = nla_get_u16(data[IFLA_IPVLAN_MODE]);
 
-	err = ipvlan_set_port_mode(port, mode);
+	err = ipvlan_set_port_mode(port, mode, extack);
 	if (err)
 		goto unlink_netdev;
 
diff --git a/drivers/net/net_failover.c b/drivers/net/net_failover.c
index e964d312f4ca..ed1166adaa2f 100644
--- a/drivers/net/net_failover.c
+++ b/drivers/net/net_failover.c
@@ -40,14 +40,14 @@ static int net_failover_open(struct net_device *dev)
 
 	primary_dev = rtnl_dereference(nfo_info->primary_dev);
 	if (primary_dev) {
-		err = dev_open(primary_dev);
+		err = dev_open(primary_dev, NULL);
 		if (err)
 			goto err_primary_open;
 	}
 
 	standby_dev = rtnl_dereference(nfo_info->standby_dev);
 	if (standby_dev) {
-		err = dev_open(standby_dev);
+		err = dev_open(standby_dev, NULL);
 		if (err)
 			goto err_standby_open;
 	}
@@ -517,7 +517,7 @@ static int net_failover_slave_register(struct net_device *slave_dev,
 	dev_hold(slave_dev);
 
 	if (netif_running(failover_dev)) {
-		err = dev_open(slave_dev);
+		err = dev_open(slave_dev, NULL);
 		if (err && (err != -EBUSY)) {
 			netdev_err(failover_dev, "Opening slave %s failed err:%d\n",
 				   slave_dev->name, err);
@@ -680,7 +680,7 @@ static int net_failover_slave_name_change(struct net_device *slave_dev,
 	/* We need to bring up the slave after the rename by udev in case
 	 * open failed with EBUSY when it was registered.
 	 */
-	dev_open(slave_dev);
+	dev_open(slave_dev, NULL);
 
 	return 0;
 }
diff --git a/drivers/net/team/team.c b/drivers/net/team/team.c
index 364f514d56d8..93576e0240dd 100644
--- a/drivers/net/team/team.c
+++ b/drivers/net/team/team.c
@@ -1212,7 +1212,7 @@ static int team_port_add(struct team *team, struct net_device *port_dev,
 		goto err_port_enter;
 	}
 
-	err = dev_open(port_dev);
+	err = dev_open(port_dev, extack);
 	if (err) {
 		netdev_dbg(dev, "Device %s opening failed\n",
 			   portname);
diff --git a/drivers/net/vrf.c b/drivers/net/vrf.c
index 21ad4b1d7f03..95909e262ba4 100644
--- a/drivers/net/vrf.c
+++ b/drivers/net/vrf.c
@@ -747,7 +747,8 @@ static int vrf_rtable_create(struct net_device *dev)
 /**************************** device handling ********************/
 
 /* cycle interface to flush neighbor cache and move routes across tables */
-static void cycle_netdev(struct net_device *dev)
+static void cycle_netdev(struct net_device *dev,
+			 struct netlink_ext_ack *extack)
 {
 	unsigned int flags = dev->flags;
 	int ret;
@@ -755,9 +756,9 @@ static void cycle_netdev(struct net_device *dev)
 	if (!netif_running(dev))
 		return;
 
-	ret = dev_change_flags(dev, flags & ~IFF_UP);
+	ret = dev_change_flags(dev, flags & ~IFF_UP, extack);
 	if (ret >= 0)
-		ret = dev_change_flags(dev, flags);
+		ret = dev_change_flags(dev, flags, extack);
 
 	if (ret < 0) {
 		netdev_err(dev,
@@ -785,7 +786,7 @@ static int do_vrf_add_slave(struct net_device *dev, struct net_device *port_dev,
 	if (ret < 0)
 		goto err;
 
-	cycle_netdev(port_dev);
+	cycle_netdev(port_dev, extack);
 
 	return 0;
 
@@ -815,7 +816,7 @@ static int do_vrf_del_slave(struct net_device *dev, struct net_device *port_dev)
 	netdev_upper_dev_unlink(port_dev, dev);
 	port_dev->priv_flags &= ~IFF_L3MDEV_SLAVE;
 
-	cycle_netdev(port_dev);
+	cycle_netdev(port_dev, NULL);
 
 	return 0;
 }
diff --git a/drivers/net/wireless/intersil/hostap/hostap_main.c b/drivers/net/wireless/intersil/hostap/hostap_main.c
index 012930d35434..b0e7c0a0617e 100644
--- a/drivers/net/wireless/intersil/hostap/hostap_main.c
+++ b/drivers/net/wireless/intersil/hostap/hostap_main.c
@@ -690,7 +690,7 @@ static int prism2_open(struct net_device *dev)
 		/* Master radio interface is needed for all operation, so open
 		 * it automatically when any virtual net_device is opened. */
 		local->master_dev_auto_open = 1;
-		dev_open(local->dev);
+		dev_open(local->dev, NULL);
 	}
 
 	netif_device_attach(dev);