Merge branch 'bonding-fix-bonding-interface-bugs'

Taehee Yoo says:

====================
bonding: fix bonding interface bugs

This patchset fixes lockdep problem in bonding interface

1. The first patch is to add missing netdev_update_lockdep_key().
After bond_release(), netdev_update_lockdep_key() should be called.
But both ioctl path and attribute path don't call
netdev_update_lockdep_key().
This patch adds missing netdev_update_lockdep_key().

2. The second patch is to export netdev_next_lower_dev_rcu symbol.
netdev_next_lower_dev_rcu() is useful to implement the function,
which is to walk their all lower interfaces.
This patch is actually a preparing patch for the third patch.

3. The last patch is to fix lockdep waring in bond_get_stats().
The stats_lock uses a dynamic lockdep key.
So, after "nomaster" operation, updating the dynamic lockdep key
routine is needed. but it doesn't
So, lockdep warning occurs.

Change log:
v1 -> v2:
 - Update headline from "fix bonding interface bugs"
   to "bonding: fix bonding interface bugs"
 - Drop a patch("bonding: do not collect slave's stats")
 - Add new patches
   - ("net: export netdev_next_lower_dev_rcu()")
   - ("bonding: fix lockdep warning in bond_get_stats()")
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/bonding/bond_main.c

@@ -3526,6 +3526,47 @@ static void bond_fold_stats(struct rtnl_link_stats64 *_res,
 	}
 }
 
+#ifdef CONFIG_LOCKDEP
+static int bond_get_lowest_level_rcu(struct net_device *dev)
+{
+	struct net_device *ldev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
+	struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
+	int cur = 0, max = 0;
+
+	now = dev;
+	iter = &dev->adj_list.lower;
+
+	while (1) {
+		next = NULL;
+		while (1) {
+			ldev = netdev_next_lower_dev_rcu(now, &iter);
+			if (!ldev)
+				break;
+
+			next = ldev;
+			niter = &ldev->adj_list.lower;
+			dev_stack[cur] = now;
+			iter_stack[cur++] = iter;
+			if (max <= cur)
+				max = cur;
+			break;
+		}
+
+		if (!next) {
+			if (!cur)
+				return max;
+			next = dev_stack[--cur];
+			niter = iter_stack[cur];
+		}
+
+		now = next;
+		iter = niter;
+	}
+
+	return max;
+}
+#endif
+
 static void bond_get_stats(struct net_device *bond_dev,
 			   struct rtnl_link_stats64 *stats)
 {
@@ -3533,11 +3574,17 @@ static void bond_get_stats(struct net_device *bond_dev,
 	struct rtnl_link_stats64 temp;
 	struct list_head *iter;
 	struct slave *slave;
+	int nest_level = 0;
 
-	spin_lock(&bond->stats_lock);
-	memcpy(stats, &bond->bond_stats, sizeof(*stats));
 
 	rcu_read_lock();
+#ifdef CONFIG_LOCKDEP
+	nest_level = bond_get_lowest_level_rcu(bond_dev);
+#endif
+
+	spin_lock_nested(&bond->stats_lock, nest_level);
+	memcpy(stats, &bond->bond_stats, sizeof(*stats));
+
 	bond_for_each_slave_rcu(bond, slave, iter) {
 		const struct rtnl_link_stats64 *new =
 			dev_get_stats(slave->dev, &temp);
@@ -3547,10 +3594,10 @@ static void bond_get_stats(struct net_device *bond_dev,
 		/* save off the slave stats for the next run */
 		memcpy(&slave->slave_stats, new, sizeof(*new));
 	}
-	rcu_read_unlock();
 
 	memcpy(&bond->bond_stats, stats, sizeof(*stats));
 	spin_unlock(&bond->stats_lock);
+	rcu_read_unlock();
 }
 
 static int bond_do_ioctl(struct net_device *bond_dev, struct ifreq *ifr, int cmd)
@@ -3640,6 +3687,8 @@ static int bond_do_ioctl(struct net_device *bond_dev, struct ifreq *ifr, int cmd
 	case BOND_RELEASE_OLD:
 	case SIOCBONDRELEASE:
 		res = bond_release(bond_dev, slave_dev);
+		if (!res)
+			netdev_update_lockdep_key(slave_dev);
 		break;
 	case BOND_SETHWADDR_OLD:
 	case SIOCBONDSETHWADDR:

drivers/net/bonding/bond_options.c

@@ -1398,6 +1398,8 @@ static int bond_option_slaves_set(struct bonding *bond,
 	case '-':
 		slave_dbg(bond->dev, dev, "Releasing interface\n");
 		ret = bond_release(bond->dev, dev);
+		if (!ret)
+			netdev_update_lockdep_key(dev);
 		break;
 
 	default:

include/linux/netdevice.h

@@ -72,6 +72,8 @@ void netdev_set_default_ethtool_ops(struct net_device *dev,
 #define NET_RX_SUCCESS		0	/* keep 'em coming, baby */
 #define NET_RX_DROP		1	/* packet dropped */
 
+#define MAX_NEST_DEV 8
+
 /*
  * Transmit return codes: transmit return codes originate from three different
  * namespaces:
@@ -4389,11 +4391,8 @@ void *netdev_lower_get_next(struct net_device *dev,
 	     ldev; \
 	     ldev = netdev_lower_get_next(dev, &(iter)))
 
-struct net_device *netdev_all_lower_get_next(struct net_device *dev,
-					     struct list_head **iter);
-struct net_device *netdev_all_lower_get_next_rcu(struct net_device *dev,
+struct net_device *netdev_next_lower_dev_rcu(struct net_device *dev,
 					     struct list_head **iter);
-
 int netdev_walk_all_lower_dev(struct net_device *dev,
 			      int (*fn)(struct net_device *lower_dev,
 					void *data),

net/core/dev.c

@@ -146,7 +146,6 @@
 #include "net-sysfs.h"
 
 #define MAX_GRO_SKBS 8
-#define MAX_NEST_DEV 8
 
 /* This should be increased if a protocol with a bigger head is added. */
 #define GRO_MAX_HEAD (MAX_HEADER + 128)
@@ -7207,7 +7206,7 @@ static int __netdev_walk_all_lower_dev(struct net_device *dev,
 	return 0;
 }
 
-static struct net_device *netdev_next_lower_dev_rcu(struct net_device *dev,
+struct net_device *netdev_next_lower_dev_rcu(struct net_device *dev,
 					     struct list_head **iter)
 {
 	struct netdev_adjacent *lower;
@@ -7220,6 +7219,7 @@ static struct net_device *netdev_next_lower_dev_rcu(struct net_device *dev,
 
 	return lower->dev;
 }
+EXPORT_SYMBOL(netdev_next_lower_dev_rcu);
 
 static u8 __netdev_upper_depth(struct net_device *dev)
 {