Merge branch 'hsr-several-code-cleanup-for-hsr-module'

Taehee Yoo says:

====================
hsr: several code cleanup for hsr module

This patchset is to clean up hsr module code.

1. The first patch is to use debugfs_remove_recursive().
If it uses debugfs_remove_recursive() instead of debugfs_remove(),
hsr_priv() doesn't need to have "node_tbl_file" pointer variable.

2. The second patch is to use extack error message.
If HSR uses the extack instead of netdev_info(), users can get
error messages immediately without any checking the kernel message.

3. The third patch is to use netdev_err() instead of WARN_ONCE().
When a packet is being sent, hsr_addr_subst_dest() is called and
it tries to find the node with the ethernet destination address.
If it couldn't find a node, it warns with WARN_ONCE().
But, using WARN_ONCE() is a little bit overdoing.
So, in this patch, netdev_err() is used instead.

4. The fourth patch is to remove unnecessary rcu_read_{lock/unlock}().
There are some rcu_read_{lock/unlock}() in hsr module and some of
them are unnecessary. In this patch,
these unnecessary rcu_read_{lock/unlock}() will be removed.

5. The fifth patch is to use upper/lower device infrastructure.
netdev_upper_dev_link() is useful to manage lower/upper interfaces.
And this function internally validates looping, maximum depth.
If hsr module uses upper/lower device infrastructure,
it can prevent these above problems.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

net/hsr/hsr_debugfs.c

@@ -113,7 +113,6 @@ void hsr_debugfs_init(struct hsr_priv *priv, struct net_device *hsr_dev)
 		priv->node_tbl_root = NULL;
 		return;
 	}
-	priv->node_tbl_file = de;
 }
 
 /* hsr_debugfs_term - Tear down debugfs intrastructure
@@ -125,9 +124,7 @@ void hsr_debugfs_init(struct hsr_priv *priv, struct net_device *hsr_dev)
 void
 hsr_debugfs_term(struct hsr_priv *priv)
 {
-	debugfs_remove(priv->node_tbl_file);
-	priv->node_tbl_file = NULL;
-	debugfs_remove(priv->node_tbl_root);
+	debugfs_remove_recursive(priv->node_tbl_root);
 	priv->node_tbl_root = NULL;
 }
 

net/hsr/hsr_device.c

@@ -57,24 +57,19 @@ static void hsr_set_operstate(struct hsr_port *master, bool has_carrier)
 static bool hsr_check_carrier(struct hsr_port *master)
 {
 	struct hsr_port *port;
-	bool has_carrier;
 
-	has_carrier = false;
+	ASSERT_RTNL();
 
-	rcu_read_lock();
-	hsr_for_each_port(master->hsr, port)
+	hsr_for_each_port(master->hsr, port) {
 		if (port->type != HSR_PT_MASTER && is_slave_up(port->dev)) {
-			has_carrier = true;
-			break;
+			netif_carrier_on(master->dev);
+			return true;
 		}
-	rcu_read_unlock();
+	}
 
-	if (has_carrier)
-		netif_carrier_on(master->dev);
-	else
-		netif_carrier_off(master->dev);
+	netif_carrier_off(master->dev);
 
-	return has_carrier;
+	return false;
 }
 
 static void hsr_check_announce(struct net_device *hsr_dev,
@@ -118,11 +113,9 @@ int hsr_get_max_mtu(struct hsr_priv *hsr)
 	struct hsr_port *port;
 
 	mtu_max = ETH_DATA_LEN;
-	rcu_read_lock();
 	hsr_for_each_port(hsr, port)
 		if (port->type != HSR_PT_MASTER)
 			mtu_max = min(port->dev->mtu, mtu_max);
-	rcu_read_unlock();
 
 	if (mtu_max < HSR_HLEN)
 		return 0;
@@ -157,7 +150,6 @@ static int hsr_dev_open(struct net_device *dev)
 	hsr = netdev_priv(dev);
 	designation = '\0';
 
-	rcu_read_lock();
 	hsr_for_each_port(hsr, port) {
 		if (port->type == HSR_PT_MASTER)
 			continue;
@@ -175,7 +167,6 @@ static int hsr_dev_open(struct net_device *dev)
 			netdev_warn(dev, "Slave %c (%s) is not up; please bring it up to get a fully working HSR network\n",
 				    designation, port->dev->name);
 	}
-	rcu_read_unlock();
 
 	if (designation == '\0')
 		netdev_warn(dev, "No slave devices configured\n");
@@ -350,22 +341,33 @@ static void hsr_announce(struct timer_list *t)
 	rcu_read_unlock();
 }
 
+static void hsr_del_ports(struct hsr_priv *hsr)
+{
+	struct hsr_port *port;
+
+	port = hsr_port_get_hsr(hsr, HSR_PT_SLAVE_A);
+	if (port)
+		hsr_del_port(port);
+
+	port = hsr_port_get_hsr(hsr, HSR_PT_SLAVE_B);
+	if (port)
+		hsr_del_port(port);
+
+	port = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
+	if (port)
+		hsr_del_port(port);
+}
+
 /* This has to be called after all the readers are gone.
  * Otherwise we would have to check the return value of
  * hsr_port_get_hsr().
  */
 static void hsr_dev_destroy(struct net_device *hsr_dev)
 {
-	struct hsr_priv *hsr;
-	struct hsr_port *port;
-	struct hsr_port *tmp;
-
-	hsr = netdev_priv(hsr_dev);
+	struct hsr_priv *hsr = netdev_priv(hsr_dev);
 
 	hsr_debugfs_term(hsr);
-
-	list_for_each_entry_safe(port, tmp, &hsr->ports, port_list)
-		hsr_del_port(port);
+	hsr_del_ports(hsr);
 
 	del_timer_sync(&hsr->prune_timer);
 	del_timer_sync(&hsr->announce_timer);
@@ -431,11 +433,10 @@ static const unsigned char def_multicast_addr[ETH_ALEN] __aligned(2) = {
 };
 
 int hsr_dev_finalize(struct net_device *hsr_dev, struct net_device *slave[2],
-		     unsigned char multicast_spec, u8 protocol_version)
+		     unsigned char multicast_spec, u8 protocol_version,
+		     struct netlink_ext_ack *extack)
 {
 	struct hsr_priv *hsr;
-	struct hsr_port *port;
-	struct hsr_port *tmp;
 	int res;
 
 	hsr = netdev_priv(hsr_dev);
@@ -478,7 +479,7 @@ int hsr_dev_finalize(struct net_device *hsr_dev, struct net_device *slave[2],
 	/* Make sure the 1st call to netif_carrier_on() gets through */
 	netif_carrier_off(hsr_dev);
 
-	res = hsr_add_port(hsr, hsr_dev, HSR_PT_MASTER);
+	res = hsr_add_port(hsr, hsr_dev, HSR_PT_MASTER, extack);
 	if (res)
 		goto err_add_master;
 
@@ -486,11 +487,11 @@ int hsr_dev_finalize(struct net_device *hsr_dev, struct net_device *slave[2],
 	if (res)
 		goto err_unregister;
 
-	res = hsr_add_port(hsr, slave[0], HSR_PT_SLAVE_A);
+	res = hsr_add_port(hsr, slave[0], HSR_PT_SLAVE_A, extack);
 	if (res)
 		goto err_add_slaves;
 
-	res = hsr_add_port(hsr, slave[1], HSR_PT_SLAVE_B);
+	res = hsr_add_port(hsr, slave[1], HSR_PT_SLAVE_B, extack);
 	if (res)
 		goto err_add_slaves;
 
@@ -502,8 +503,7 @@ int hsr_dev_finalize(struct net_device *hsr_dev, struct net_device *slave[2],
 err_add_slaves:
 	unregister_netdevice(hsr_dev);
 err_unregister:
-	list_for_each_entry_safe(port, tmp, &hsr->ports, port_list)
-		hsr_del_port(port);
+	hsr_del_ports(hsr);
 err_add_master:
 	hsr_del_self_node(hsr);
 

net/hsr/hsr_device.h

@@ -13,7 +13,8 @@
 
 void hsr_dev_setup(struct net_device *dev);
 int hsr_dev_finalize(struct net_device *hsr_dev, struct net_device *slave[2],
-		     unsigned char multicast_spec, u8 protocol_version);
+		     unsigned char multicast_spec, u8 protocol_version,
+		     struct netlink_ext_ack *extack);
 void hsr_check_carrier_and_operstate(struct hsr_priv *hsr);
 bool is_hsr_master(struct net_device *dev);
 int hsr_get_max_mtu(struct hsr_priv *hsr);

net/hsr/hsr_framereg.c

@@ -318,7 +318,8 @@ void hsr_addr_subst_dest(struct hsr_node *node_src, struct sk_buff *skb,
 	node_dst = find_node_by_addr_A(&port->hsr->node_db,
 				       eth_hdr(skb)->h_dest);
 	if (!node_dst) {
-		WARN_ONCE(1, "%s: Unknown node\n", __func__);
+		if (net_ratelimit())
+			netdev_err(skb->dev, "%s: Unknown node\n", __func__);
 		return;
 	}
 	if (port->type != node_dst->addr_B_port)

net/hsr/hsr_main.c

@@ -85,7 +85,8 @@ static int hsr_netdev_notify(struct notifier_block *nb, unsigned long event,
 		master->dev->mtu = mtu_max;
 		break;
 	case NETDEV_UNREGISTER:
-		hsr_del_port(port);
+		if (!is_hsr_master(dev))
+			hsr_del_port(port);
 		break;
 	case NETDEV_PRE_TYPE_CHANGE:
 		/* HSR works only on Ethernet devices. Refuse slave to change

net/hsr/hsr_main.h

@@ -166,7 +166,6 @@ struct hsr_priv {
 	unsigned char		sup_multicast_addr[ETH_ALEN];
 #ifdef	CONFIG_DEBUG_FS
 	struct dentry *node_tbl_root;
-	struct dentry *node_tbl_file;
 #endif
 };
 

net/hsr/hsr_netlink.c

@@ -35,26 +35,34 @@ static int hsr_newlink(struct net *src_net, struct net_device *dev,
 	unsigned char multicast_spec, hsr_version;
 
 	if (!data) {
-		netdev_info(dev, "HSR: No slave devices specified\n");
+		NL_SET_ERR_MSG_MOD(extack, "No slave devices specified");
 		return -EINVAL;
 	}
 	if (!data[IFLA_HSR_SLAVE1]) {
-		netdev_info(dev, "HSR: Slave1 device not specified\n");
+		NL_SET_ERR_MSG_MOD(extack, "Slave1 device not specified");
 		return -EINVAL;
 	}
 	link[0] = __dev_get_by_index(src_net,
 				     nla_get_u32(data[IFLA_HSR_SLAVE1]));
+	if (!link[0]) {
+		NL_SET_ERR_MSG_MOD(extack, "Slave1 does not exist");
+		return -EINVAL;
+	}
 	if (!data[IFLA_HSR_SLAVE2]) {
-		netdev_info(dev, "HSR: Slave2 device not specified\n");
+		NL_SET_ERR_MSG_MOD(extack, "Slave2 device not specified");
 		return -EINVAL;
 	}
 	link[1] = __dev_get_by_index(src_net,
 				     nla_get_u32(data[IFLA_HSR_SLAVE2]));
+	if (!link[1]) {
+		NL_SET_ERR_MSG_MOD(extack, "Slave2 does not exist");
+		return -EINVAL;
+	}
 
-	if (!link[0] || !link[1])
-		return -ENODEV;
-	if (link[0] == link[1])
+	if (link[0] == link[1]) {
+		NL_SET_ERR_MSG_MOD(extack, "Slave1 and Slave2 are same");
 		return -EINVAL;
+	}
 
 	if (!data[IFLA_HSR_MULTICAST_SPEC])
 		multicast_spec = 0;
@@ -66,34 +74,25 @@ static int hsr_newlink(struct net *src_net, struct net_device *dev,
 	else
 		hsr_version = nla_get_u8(data[IFLA_HSR_VERSION]);
 
-	return hsr_dev_finalize(dev, link, multicast_spec, hsr_version);
+	return hsr_dev_finalize(dev, link, multicast_spec, hsr_version, extack);
 }
 
 static int hsr_fill_info(struct sk_buff *skb, const struct net_device *dev)
 {
-	struct hsr_priv *hsr;
+	struct hsr_priv *hsr = netdev_priv(dev);
 	struct hsr_port *port;
-	int res;
-
-	hsr = netdev_priv(dev);
-
-	res = 0;
 
-	rcu_read_lock();
 	port = hsr_port_get_hsr(hsr, HSR_PT_SLAVE_A);
-	if (port)
-		res = nla_put_u32(skb, IFLA_HSR_SLAVE1, port->dev->ifindex);
-	rcu_read_unlock();
-	if (res)
-		goto nla_put_failure;
+	if (port) {
+		if (nla_put_u32(skb, IFLA_HSR_SLAVE1, port->dev->ifindex))
+			goto nla_put_failure;
+	}
 
-	rcu_read_lock();
 	port = hsr_port_get_hsr(hsr, HSR_PT_SLAVE_B);
-	if (port)
-		res = nla_put_u32(skb, IFLA_HSR_SLAVE2, port->dev->ifindex);
-	rcu_read_unlock();
-	if (res)
-		goto nla_put_failure;
+	if (port) {
+		if (nla_put_u32(skb, IFLA_HSR_SLAVE2, port->dev->ifindex))
+			goto nla_put_failure;
+	}
 
 	if (nla_put(skb, IFLA_HSR_SUPERVISION_ADDR, ETH_ALEN,
 		    hsr->sup_multicast_addr) ||

net/hsr/hsr_slave.c

@@ -25,7 +25,6 @@ static rx_handler_result_t hsr_handle_frame(struct sk_buff **pskb)
 		return RX_HANDLER_PASS;
 	}
 
-	rcu_read_lock(); /* hsr->node_db, hsr->ports */
 	port = hsr_port_get_rcu(skb->dev);
 	if (!port)
 		goto finish_pass;
@@ -45,11 +44,9 @@ static rx_handler_result_t hsr_handle_frame(struct sk_buff **pskb)
 	hsr_forward_skb(skb, port);
 
 finish_consume:
-	rcu_read_unlock(); /* hsr->node_db, hsr->ports */
 	return RX_HANDLER_CONSUMED;
 
 finish_pass:
-	rcu_read_unlock(); /* hsr->node_db, hsr->ports */
 	return RX_HANDLER_PASS;
 }
 
@@ -58,33 +55,37 @@ bool hsr_port_exists(const struct net_device *dev)
 	return rcu_access_pointer(dev->rx_handler) == hsr_handle_frame;
 }
 
-static int hsr_check_dev_ok(struct net_device *dev)
+static int hsr_check_dev_ok(struct net_device *dev,
+			    struct netlink_ext_ack *extack)
 {
 	/* Don't allow HSR on non-ethernet like devices */
 	if ((dev->flags & IFF_LOOPBACK) || dev->type != ARPHRD_ETHER ||
 	    dev->addr_len != ETH_ALEN) {
-		netdev_info(dev, "Cannot use loopback or non-ethernet device as HSR slave.\n");
+		NL_SET_ERR_MSG_MOD(extack, "Cannot use loopback or non-ethernet device as HSR slave.");
 		return -EINVAL;
 	}
 
 	/* Don't allow enslaving hsr devices */
 	if (is_hsr_master(dev)) {
-		netdev_info(dev, "Cannot create trees of HSR devices.\n");
+		NL_SET_ERR_MSG_MOD(extack,
+				   "Cannot create trees of HSR devices.");
 		return -EINVAL;
 	}
 
 	if (hsr_port_exists(dev)) {
-		netdev_info(dev, "This device is already a HSR slave.\n");
+		NL_SET_ERR_MSG_MOD(extack,
+				   "This device is already a HSR slave.");
 		return -EINVAL;
 	}
 
 	if (is_vlan_dev(dev)) {
-		netdev_info(dev, "HSR on top of VLAN is not yet supported in this driver.\n");
+		NL_SET_ERR_MSG_MOD(extack, "HSR on top of VLAN is not yet supported in this driver.");
 		return -EINVAL;
 	}
 
 	if (dev->priv_flags & IFF_DONT_BRIDGE) {
-		netdev_info(dev, "This device does not support bridging.\n");
+		NL_SET_ERR_MSG_MOD(extack,
+				   "This device does not support bridging.");
 		return -EOPNOTSUPP;
 	}
 
@@ -96,19 +97,25 @@ static int hsr_check_dev_ok(struct net_device *dev)
 }
 
 /* Setup device to be added to the HSR bridge. */
-static int hsr_portdev_setup(struct net_device *dev, struct hsr_port *port)
+static int hsr_portdev_setup(struct hsr_priv *hsr, struct net_device *dev,
+			     struct hsr_port *port,
+			     struct netlink_ext_ack *extack)
+
 {
+	struct net_device *hsr_dev;
+	struct hsr_port *master;
 	int res;
 
-	dev_hold(dev);
 	res = dev_set_promiscuity(dev, 1);
 	if (res)
 		goto fail_promiscuity;
 
-	/* FIXME:
-	 * What does net device "adjacency" mean? Should we do
-	 * res = netdev_master_upper_dev_link(port->dev, port->hsr->dev); ?
-	 */
+	master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
+	hsr_dev = master->dev;
+
+	res = netdev_upper_dev_link(dev, hsr_dev, extack);
+	if (res)
+		goto fail_upper_dev_link;
 
 	res = netdev_rx_handler_register(dev, hsr_handle_frame, port);
 	if (res)
@@ -118,6 +125,8 @@ static int hsr_portdev_setup(struct net_device *dev, struct hsr_port *port)
 	return 0;
 
 fail_rx_handler:
+	netdev_upper_dev_unlink(dev, hsr_dev);
+fail_upper_dev_link:
 	dev_set_promiscuity(dev, -1);
 fail_promiscuity:
 	dev_put(dev);
@@ -126,13 +135,13 @@ static int hsr_portdev_setup(struct net_device *dev, struct hsr_port *port)
 }
 
 int hsr_add_port(struct hsr_priv *hsr, struct net_device *dev,
-		 enum hsr_port_type type)
+		 enum hsr_port_type type, struct netlink_ext_ack *extack)
 {
 	struct hsr_port *port, *master;
 	int res;
 
 	if (type != HSR_PT_MASTER) {
-		res = hsr_check_dev_ok(dev);
+		res = hsr_check_dev_ok(dev, extack);
 		if (res)
 			return res;
 	}
@@ -146,7 +155,7 @@ int hsr_add_port(struct hsr_priv *hsr, struct net_device *dev,
 		return -ENOMEM;
 
 	if (type != HSR_PT_MASTER) {
-		res = hsr_portdev_setup(dev, port);
+		res = hsr_portdev_setup(hsr, dev, port, extack);
 		if (res)
 			goto fail_dev_setup;
 	}
@@ -179,21 +188,14 @@ void hsr_del_port(struct hsr_port *port)
 	list_del_rcu(&port->port_list);
 
 	if (port != master) {
-		if (master) {
-			netdev_update_features(master->dev);
-			dev_set_mtu(master->dev, hsr_get_max_mtu(hsr));
-		}
+		netdev_update_features(master->dev);
+		dev_set_mtu(master->dev, hsr_get_max_mtu(hsr));
 		netdev_rx_handler_unregister(port->dev);
 		dev_set_promiscuity(port->dev, -1);
+		netdev_upper_dev_unlink(port->dev, master->dev);
 	}
 
-	/* FIXME?
-	 * netdev_upper_dev_unlink(port->dev, port->hsr->dev);
-	 */
-
 	synchronize_rcu();
 
-	if (port != master)
-		dev_put(port->dev);
 	kfree(port);
 }

net/hsr/hsr_slave.h

@@ -13,7 +13,7 @@
 #include "hsr_main.h"
 
 int hsr_add_port(struct hsr_priv *hsr, struct net_device *dev,
-		 enum hsr_port_type pt);
+		 enum hsr_port_type pt, struct netlink_ext_ack *extack);
 void hsr_del_port(struct hsr_port *port);
 bool hsr_port_exists(const struct net_device *dev);