From 3158bf7d414b69fdc0c715d0a4d82e12b74ef974 Mon Sep 17 00:00:00 2001
From: Moni Shoua <monis@voltaire.com>
Date: Tue, 9 Oct 2007 19:43:41 -0700
Subject: [PATCH] net/bonding: Handlle wrong assumptions that slave is always
 an Ethernet device

bonding sometimes uses Ethernet constants (such as MTU and address length) which
are not good when it enslaves non Ethernet devices (such as InfiniBand).

Signed-off-by: Moni Shoua <monis at voltaire.com>
Acked-by: Jay Vosburgh <fubar@us.ibm.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
---
 drivers/net/bonding/bond_main.c  |  3 ++-
 drivers/net/bonding/bond_sysfs.c | 10 ++++++++--
 drivers/net/bonding/bonding.h    |  1 +
 3 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 3eebfe287533..7be23364a9d6 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -1225,7 +1225,8 @@ static int bond_compute_features(struct bonding *bond)
 	struct slave *slave;
 	struct net_device *bond_dev = bond->dev;
 	unsigned long features = bond_dev->features;
-	unsigned short max_hard_header_len = ETH_HLEN;
+	unsigned short max_hard_header_len = max((u16)ETH_HLEN,
+						bond_dev->hard_header_len);
 	int i;
 
 	features &= ~(NETIF_F_ALL_CSUM | BOND_VLAN_FEATURES);
diff --git a/drivers/net/bonding/bond_sysfs.c b/drivers/net/bonding/bond_sysfs.c
index ca4e429f9ec2..583c568e1764 100644
--- a/drivers/net/bonding/bond_sysfs.c
+++ b/drivers/net/bonding/bond_sysfs.c
@@ -260,6 +260,7 @@ static ssize_t bonding_store_slaves(struct device *d,
 	char command[IFNAMSIZ + 1] = { 0, };
 	char *ifname;
 	int i, res, found, ret = count;
+	u32 original_mtu;
 	struct slave *slave;
 	struct net_device *dev = NULL;
 	struct bonding *bond = to_bond(d);
@@ -325,6 +326,7 @@ static ssize_t bonding_store_slaves(struct device *d,
 		}
 
 		/* Set the slave's MTU to match the bond */
+		original_mtu = dev->mtu;
 		if (dev->mtu != bond->dev->mtu) {
 			if (dev->change_mtu) {
 				res = dev->change_mtu(dev,
@@ -339,6 +341,9 @@ static ssize_t bonding_store_slaves(struct device *d,
 		}
 		rtnl_lock();
 		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;
 		rtnl_unlock();
 		if (res) {
 			ret = res;
@@ -351,6 +356,7 @@ static ssize_t bonding_store_slaves(struct device *d,
 		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) {
@@ -365,9 +371,9 @@ static ssize_t bonding_store_slaves(struct device *d,
 			}
 			/* set the slave MTU to the default */
 			if (dev->change_mtu) {
-				dev->change_mtu(dev, 1500);
+				dev->change_mtu(dev, original_mtu);
 			} else {
-				dev->mtu = 1500;
+				dev->mtu = original_mtu;
 			}
 		}
 		else {
diff --git a/drivers/net/bonding/bonding.h b/drivers/net/bonding/bonding.h
index 5011ba9e4661..ad9c632f88e4 100644
--- a/drivers/net/bonding/bonding.h
+++ b/drivers/net/bonding/bonding.h
@@ -156,6 +156,7 @@ struct slave {
 	s8     link;    /* one of BOND_LINK_XXXX */
 	s8     state;   /* one of BOND_STATE_XXXX */
 	u32    original_flags;
+	u32    original_mtu;
 	u32    link_failure_count;
 	u16    speed;
 	u8     duplex;