* [08/38] arp_notify: allow drivers to explicitly request a notification event.
[not found] <20100806183250.GA23019@kroah.com>
@ 2010-08-06 18:30 ` Greg KH
2010-08-06 18:30 ` [09/38] xen: netfront: explicitly generate arp_notify event after migration Greg KH
1 sibling, 0 replies; 4+ messages in thread
From: Greg KH @ 2010-08-06 18:30 UTC (permalink / raw)
To: linux-kernel, stable
Cc: stable-review, torvalds, akpm, alan, Ian Campbell,
Stephen Hemminger, Jeremy Fitzhardinge, David S. Miller, netdev
2.6.35-stable review patch. If anyone has any objections, please let us know.
------------------
From: Ian Campbell <Ian.Campbell@citrix.com>
commit 06c4648d46d1b757d6b9591a86810be79818b60c upstream.
Currently such notifications are only generated when the device comes up or the
address changes. However one use case for these notifications is to enable
faster network recovery after a virtual machine migration (by causing switches
to relearn their MAC tables). A migration appears to the network stack as a
temporary loss of carrier and therefore does not trigger either of the current
conditions. Rather than adding carrier up as a trigger (which can cause issues
when interfaces a flapping) simply add an interface which the driver can use
to explicitly trigger the notification.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Cc: Stephen Hemminger <shemminger@linux-foundation.org>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: netdev@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
include/linux/netdevice.h | 2 ++
include/linux/notifier.h | 1 +
net/ipv4/devinet.c | 1 +
net/sched/sch_generic.c | 18 ++++++++++++++++++
4 files changed, 22 insertions(+)
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1775,6 +1775,8 @@ extern void netif_carrier_on(struct net_
extern void netif_carrier_off(struct net_device *dev);
+extern void netif_notify_peers(struct net_device *dev);
+
/**
* netif_dormant_on - mark device as dormant.
* @dev: network device
--- a/include/linux/notifier.h
+++ b/include/linux/notifier.h
@@ -210,6 +210,7 @@ static inline int notifier_to_errno(int
#define NETDEV_POST_INIT 0x0010
#define NETDEV_UNREGISTER_BATCH 0x0011
#define NETDEV_BONDING_DESLAVE 0x0012
+#define NETDEV_NOTIFY_PEERS 0x0012
#define SYS_DOWN 0x0001 /* Notify of system down */
#define SYS_RESTART SYS_DOWN
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -1081,6 +1081,7 @@ static int inetdev_event(struct notifier
}
ip_mc_up(in_dev);
/* fall through */
+ case NETDEV_NOTIFY_PEERS:
case NETDEV_CHANGEADDR:
/* Send gratuitous ARP to notify of link change */
if (IN_DEV_ARP_NOTIFY(in_dev)) {
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -327,6 +327,24 @@ void netif_carrier_off(struct net_device
}
EXPORT_SYMBOL(netif_carrier_off);
+/**
+ * netif_notify_peers - notify network peers about existence of @dev
+ * @dev: network device
+ *
+ * Generate traffic such that interested network peers are aware of
+ * @dev, such as by generating a gratuitous ARP. This may be used when
+ * a device wants to inform the rest of the network about some sort of
+ * reconfiguration such as a failover event or virtual machine
+ * migration.
+ */
+void netif_notify_peers(struct net_device *dev)
+{
+ rtnl_lock();
+ call_netdevice_notifiers(NETDEV_NOTIFY_PEERS, dev);
+ rtnl_unlock();
+}
+EXPORT_SYMBOL(netif_notify_peers);
+
/* "NOOP" scheduler: the best scheduler, recommended for all interfaces
under all circumstances. It is difficult to invent anything faster or
cheaper.
^ permalink raw reply [flat|nested] 4+ messages in thread* [09/38] xen: netfront: explicitly generate arp_notify event after migration.
[not found] <20100806183250.GA23019@kroah.com>
2010-08-06 18:30 ` [08/38] arp_notify: allow drivers to explicitly request a notification event Greg KH
@ 2010-08-06 18:30 ` Greg KH
2010-08-10 13:07 ` Ian Campbell
1 sibling, 1 reply; 4+ messages in thread
From: Greg KH @ 2010-08-06 18:30 UTC (permalink / raw)
To: linux-kernel, stable
Cc: Jeremy Fitzhardinge, xen-devel, Ian Campbell, torvalds,
David S. Miller, netdev, akpm, Stephen Hemminger, stable-review,
alan
2.6.35-stable review patch. If anyone has any objections, please let us know.
------------------
From: Ian Campbell <Ian.Campbell@citrix.com>
commit 592970675c9522bde588b945388c7995c8b51328 upstream.
Use newly introduced netif_notify_peers() method to ensure a gratuitous ARP is
generated after a migration.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Cc: Stephen Hemminger <shemminger@linux-foundation.org>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: netdev@vger.kernel.org
Cc: xen-devel@lists.xensource.com
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
drivers/net/xen-netfront.c | 1 +
1 file changed, 1 insertion(+)
--- a/drivers/net/xen-netfront.c
+++ b/drivers/net/xen-netfront.c
@@ -1621,6 +1621,7 @@ static void backend_changed(struct xenbu
if (xennet_connect(netdev) != 0)
break;
xenbus_switch_state(dev, XenbusStateConnected);
+ netif_notify_peers(netdev);
break;
case XenbusStateClosing:
^ permalink raw reply [flat|nested] 4+ messages in thread