[ofa-general] [RFC PATCH 1/4] net/bonding: announce fail-over for the active-backup mode

[Or Gerlitz]

Enhance bonding to announce fail-over for the active-backup mode through
the netdev events notifier chain mechanism. Such an event can be of use
for the RDMA CM (communication manager) to let native RDMA ULPs (eg
NFS-RDMA, iSER) always use the same links as the IP stack does.

Signed-off-by: Or Gerlitz <ogerlitz at voltaire.com>

I am sending the patch along with the series before its review in netdev since
its needed later in patch #4 and I see some issues while testing it with
2.6.26-rc2 which I am pretty sure not related directly to my work, so I'd like
to do some more testing before handing it to the bonding maintainer.

Index: linux-2.6.26-rc2/drivers/net/bonding/bond_main.c
===================================================================
--- linux-2.6.26-rc2.orig/drivers/net/bonding/bond_main.c	2008-05-13 10:02:22.000000000 +0300
+++ linux-2.6.26-rc2/drivers/net/bonding/bond_main.c	2008-05-13 16:34:28.000000000 +0300
@@ -1117,6 +1117,7 @@ void bond_change_active_slave(struct bon
 			bond->send_grat_arp = 1;
 		} else
 			bond_send_gratuitous_arp(bond);
+		netdev_bonding_change(bond->dev);
 	}
 }

Index: linux-2.6.26-rc2/include/linux/notifier.h
===================================================================
--- linux-2.6.26-rc2.orig/include/linux/notifier.h	2008-05-13 10:02:30.000000000 +0300
+++ linux-2.6.26-rc2/include/linux/notifier.h	2008-05-13 11:50:44.000000000 +0300
@@ -197,6 +197,7 @@ static inline int notifier_to_errno(int
 #define NETDEV_GOING_DOWN	0x0009
 #define NETDEV_CHANGENAME	0x000A
 #define NETDEV_FEAT_CHANGE	0x000B
+#define NETDEV_BONDING_FAILOVER 0x000C

 #define SYS_DOWN	0x0001	/* Notify of system down */
 #define SYS_RESTART	SYS_DOWN
Index: linux-2.6.26-rc2/include/linux/netdevice.h
===================================================================
--- linux-2.6.26-rc2.orig/include/linux/netdevice.h	2008-05-13 10:02:30.000000000 +0300
+++ linux-2.6.26-rc2/include/linux/netdevice.h	2008-05-13 11:50:20.000000000 +0300
@@ -1459,6 +1459,7 @@ extern void		__dev_addr_unsync(struct de
 extern void		dev_set_promiscuity(struct net_device *dev, int inc);
 extern void		dev_set_allmulti(struct net_device *dev, int inc);
 extern void		netdev_state_change(struct net_device *dev);
+extern void		netdev_bonding_change(struct net_device *dev);
 extern void		netdev_features_change(struct net_device *dev);
 /* Load a device via the kmod */
 extern void		dev_load(struct net *net, const char *name);
Index: linux-2.6.26-rc2/net/core/dev.c
===================================================================
--- linux-2.6.26-rc2.orig/net/core/dev.c	2008-05-13 10:02:31.000000000 +0300
+++ linux-2.6.26-rc2/net/core/dev.c	2008-05-13 11:50:49.000000000 +0300
@@ -956,6 +956,12 @@ void netdev_state_change(struct net_devi
 	}
 }

+void netdev_bonding_change(struct net_device *dev)
+{
+	call_netdevice_notifiers(NETDEV_BONDING_FAILOVER, dev);
+}
+EXPORT_SYMBOL(netdev_bonding_change);
+
 /**
  *	dev_load 	- load a network module
  *	@net: the applicable net namespace