[Patch net-next-2.6] netpoll: disable netpoll when enslave a device

From: Amerigo Wang
Date: Wed May 18 2011 - 06:01:28 EST


Currently we do nothing when we enslave a net device which is running netconsole.
Neil pointed out that we may get weird results in such case, so let's disable
netpoll on the device being enslaved. I think it is too harsh to prevent
the device being ensalved if it is running netconsole.

By the way, this patch also removes the NETDEV_GOING_DOWN from netconsole
netdev notifier, because netpoll will check if the device is running or not
and we don't handle NETDEV_PRE_UP neither.

Signed-off-by: WANG Cong <amwang@xxxxxxxxxx>
Cc: Neil Horman <nhorman@xxxxxxxxxx>

---
diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 088fd84..b9c70c5 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -1640,6 +1640,8 @@ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev)
}
}

+ netdev_bonding_change(slave_dev, NETDEV_ENSLAVE);
+
/* If this is the first slave, then we need to set the master's hardware
* address to be the same as the slave's. */
if (is_zero_ether_addr(bond->dev->dev_addr))
diff --git a/drivers/net/netconsole.c b/drivers/net/netconsole.c
index a83e101..0c3e8de 100644
--- a/drivers/net/netconsole.c
+++ b/drivers/net/netconsole.c
@@ -621,7 +621,8 @@ static int netconsole_netdev_event(struct notifier_block *this,
bool stopped = false;

if (!(event == NETDEV_CHANGENAME || event == NETDEV_UNREGISTER ||
- event == NETDEV_BONDING_DESLAVE || event == NETDEV_GOING_DOWN))
+ event == NETDEV_BONDING_DESLAVE || event == NETDEV_GOING_DOWN ||
+ event == NETDEV_ENSLAVE))
goto done;

spin_lock_irqsave(&target_list_lock, flags);
@@ -650,8 +651,8 @@ restart:
goto restart;
}
/* Fall through */
- case NETDEV_GOING_DOWN:
case NETDEV_BONDING_DESLAVE:
+ case NETDEV_ENSLAVE:
nt->enabled = 0;
stopped = true;
break;
@@ -660,10 +661,21 @@ restart:
netconsole_target_put(nt);
}
spin_unlock_irqrestore(&target_list_lock, flags);
- if (stopped && (event == NETDEV_UNREGISTER || event == NETDEV_BONDING_DESLAVE))
+ if (stopped) {
printk(KERN_INFO "netconsole: network logging stopped on "
- "interface %s as it %s\n", dev->name,
- event == NETDEV_UNREGISTER ? "unregistered" : "released slaves");
+ "interface %s as it ", dev->name);
+ switch (event) {
+ case NETDEV_UNREGISTER:
+ printk(KERN_CONT "unregistered\n");
+ break;
+ case NETDEV_BONDING_DESLAVE:
+ printk(KERN_CONT "released slaves\n");
+ break;
+ case NETDEV_ENSLAVE:
+ printk(KERN_CONT "is enslaved\n");
+ break;
+ }
+ }

done:
return NOTIFY_DONE;
diff --git a/include/linux/notifier.h b/include/linux/notifier.h
index 621dfa1..3d82867 100644
--- a/include/linux/notifier.h
+++ b/include/linux/notifier.h
@@ -211,6 +211,7 @@ static inline int notifier_to_errno(int ret)
#define NETDEV_UNREGISTER_BATCH 0x0011
#define NETDEV_BONDING_DESLAVE 0x0012
#define NETDEV_NOTIFY_PEERS 0x0013
+#define NETDEV_ENSLAVE 0x0014

#define SYS_DOWN 0x0001 /* Notify of system down */
#define SYS_RESTART SYS_DOWN
--
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