bonding: move slave MTU handling from sysfs V2

V1->V2: corrected res/ret use

For some reason, MTU handling (storing, and restoring) is taking  place in
bond_sysfs. The correct place for this code is in bond_enslave, bond_release.
So move it there.
Signed-off-by: Jiri Pirko <jpirko@redhat.com>
Signed-off-by: Jay Vosburgh <fubar@us.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/bonding/bond_main.c

@@ -1533,6 +1533,14 @@ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev)
 	 */
 	new_slave->original_flags = slave_dev->flags;
 
+	/* Save slave's original mtu and then set it to match the bond */
+	new_slave->original_mtu = slave_dev->mtu;
+	res = dev_set_mtu(slave_dev, bond->dev->mtu);
+	if (res) {
+		pr_debug("Error %d calling dev_set_mtu\n", res);
+		goto err_free;
+	}
+
 	/*
 	 * Save slave's original ("permanent") mac address for modes
 	 * that need it, and for restoring it upon release, and then
@@ -1550,7 +1558,7 @@ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev)
 		res = dev_set_mac_address(slave_dev, &addr);
 		if (res) {
 			pr_debug("Error %d calling set_mac_address\n", res);
-			goto err_free;
+			goto err_restore_mtu;
 		}
 	}
 
@@ -1785,6 +1793,9 @@ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev)
 		dev_set_mac_address(slave_dev, &addr);
 	}
 
+err_restore_mtu:
+	dev_set_mtu(slave_dev, new_slave->original_mtu);
+
 err_free:
 	kfree(new_slave);
 
@@ -1969,6 +1980,8 @@ int bond_release(struct net_device *bond_dev, struct net_device *slave_dev)
 		dev_set_mac_address(slave_dev, &addr);
 	}
 
+	dev_set_mtu(slave_dev, slave->original_mtu);
+
 	slave_dev->priv_flags &= ~(IFF_MASTER_8023AD | IFF_MASTER_ALB |
 				   IFF_SLAVE_INACTIVE | IFF_BONDING |
 				   IFF_SLAVE_NEEDARP);

drivers/net/bonding/bond_sysfs.c

@@ -220,7 +220,6 @@ static ssize_t bonding_store_slaves(struct device *d,
 	char command[IFNAMSIZ + 1] = { 0, };
 	char *ifname;
 	int i, res, ret = count;
-	u32 original_mtu;
 	struct slave *slave;
 	struct net_device *dev = NULL;
 	struct bonding *bond = to_bond(d);
@@ -281,18 +280,7 @@ static ssize_t bonding_store_slaves(struct device *d,
 			memcpy(bond->dev->dev_addr, dev->dev_addr,
 			       dev->addr_len);
 
-		/* Set the slave's MTU to match the bond */
-		original_mtu = dev->mtu;
-		res = dev_set_mtu(dev, bond->dev->mtu);
-		if (res) {
-			ret = res;
-			goto out;
-		}
-
 		res = bond_enslave(bond->dev, dev);
-		bond_for_each_slave(bond, slave, i)
-			if (strnicmp(slave->dev->name, ifname, IFNAMSIZ) == 0)
-				slave->original_mtu = original_mtu;
 		if (res)
 			ret = res;
 
@@ -301,23 +289,17 @@ static ssize_t bonding_store_slaves(struct device *d,
 
 	if (command[0] == '-') {
 		dev = NULL;
-		original_mtu = 0;
 		bond_for_each_slave(bond, slave, i)
 			if (strnicmp(slave->dev->name, ifname, IFNAMSIZ) == 0) {
 				dev = slave->dev;
-				original_mtu = slave->original_mtu;
 				break;
 			}
 		if (dev) {
 			pr_info("%s: Removing slave %s\n",
 				bond->dev->name, dev->name);
-				res = bond_release(bond->dev, dev);
-			if (res) {
+			res = bond_release(bond->dev, dev);
+			if (res)
 				ret = res;
-				goto out;
-			}
-			/* set the slave MTU to the default */
-			dev_set_mtu(dev, original_mtu);
 		} else {
 			pr_err("unable to remove non-existent slave %s for bond %s.\n",
 			       ifname, bond->dev->name);