On Wed, Jul 5, 2017 at 8:57 AM, Nicolas Dichtel
<[email protected]> wrote:
> When a device changes from one netns to another, it's first unregistered,
> then the netns reference is updated and the dev is registered in the new
> netns. Thus, when a slave moves to another netns, it is first
> unregistered. This triggers a NETDEV_UNREGISTER event which is caught by
> the bonding driver. The driver calls bond_release(), which calls
> dev_set_mtu() and thus triggers NETDEV_CHANGEMTU (the device is still in
> the old netns).
I think in this special case it is meaningless to send
NETDEV_CHANGEMTU, because the device is dying within
its old netns, who still cares about its mtu change?
Something like the attached patch...
diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 8ab6bdb..2971af1 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -1820,7 +1820,7 @@ int bond_enslave(struct net_device *bond_dev, struct
net_device *slave_dev)
*/
static int __bond_release_one(struct net_device *bond_dev,
struct net_device *slave_dev,
- bool all)
+ bool all, bool unregister)
{
struct bonding *bond = netdev_priv(bond_dev);
struct slave *slave, *oldcurrent;
@@ -1965,7 +1965,10 @@ static int __bond_release_one(struct net_device
*bond_dev,
dev_set_mac_address(slave_dev, (struct sockaddr *)&ss);
}
- dev_set_mtu(slave_dev, slave->original_mtu);
+ if (unregister)
+ __dev_set_mtu(slave_dev, slave->original_mtu);
+ else
+ dev_set_mtu(slave_dev, slave->original_mtu);
slave_dev->priv_flags &= ~IFF_BONDING;
@@ -1977,7 +1980,7 @@ static int __bond_release_one(struct net_device *bond_dev,
/* A wrapper used because of ndo_del_link */
int bond_release(struct net_device *bond_dev, struct net_device *slave_dev)
{
- return __bond_release_one(bond_dev, slave_dev, false);
+ return __bond_release_one(bond_dev, slave_dev, false, false);
}
/* First release a slave and then destroy the bond if no more slaves are left.
@@ -1989,7 +1992,7 @@ static int bond_release_and_destroy(struct net_device
*bond_dev,
struct bonding *bond = netdev_priv(bond_dev);
int ret;
- ret = bond_release(bond_dev, slave_dev);
+ ret = __bond_release_one(bond_dev, slave_dev, false, true);
if (ret == 0 && !bond_has_slaves(bond)) {
bond_dev->priv_flags |= IFF_DISABLE_NETPOLL;
netdev_info(bond_dev, "Destroying bond %s\n",
@@ -3060,7 +3063,7 @@ static int bond_slave_netdev_event(unsigned long event,
if (bond_dev->type != ARPHRD_ETHER)
bond_release_and_destroy(bond_dev, slave_dev);
else
- bond_release(bond_dev, slave_dev);
+ __bond_release_one(bond_dev, slave_dev, false, true);
break;
case NETDEV_UP:
case NETDEV_CHANGE:
@@ -4257,7 +4260,7 @@ static void bond_uninit(struct net_device *bond_dev)
/* Release the bonded slaves */
bond_for_each_slave(bond, slave, iter)
- __bond_release_one(bond_dev, slave->dev, true);
+ __bond_release_one(bond_dev, slave->dev, true, true);
netdev_info(bond_dev, "Released all slaves\n");
arr = rtnl_dereference(bond->slave_arr);
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 4ed952c..e4030db 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -3287,6 +3287,7 @@ void __dev_notify_flags(struct net_device *, unsigned int
old_flags,
int dev_change_name(struct net_device *, const char *);
int dev_set_alias(struct net_device *, const char *, size_t);
int dev_change_net_namespace(struct net_device *, struct net *, const char *);
+int __dev_set_mtu(struct net_device *, int);
int dev_set_mtu(struct net_device *, int);
void dev_set_group(struct net_device *, int);
int dev_set_mac_address(struct net_device *, struct sockaddr *);
diff --git a/net/core/dev.c b/net/core/dev.c
index 416137c..e567de8 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -6688,7 +6688,7 @@ int dev_change_flags(struct net_device *dev, unsigned int
flags)
}
EXPORT_SYMBOL(dev_change_flags);
-static int __dev_set_mtu(struct net_device *dev, int new_mtu)
+int __dev_set_mtu(struct net_device *dev, int new_mtu)
{
const struct net_device_ops *ops = dev->netdev_ops;
@@ -6698,6 +6698,7 @@ static int __dev_set_mtu(struct net_device *dev, int
new_mtu)
dev->mtu = new_mtu;
return 0;
}
+EXPORT_SYMBOL(__dev_set_mtu);
/**
* dev_set_mtu - Change maximum transfer unit
