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authorIan Campbell <Ian.Campbell@citrix.com>2010-05-26 00:09:42 +0000
committerDavid S. Miller <davem@davemloft.net>2010-05-31 00:27:44 -0700
commit06c4648d46d1b757d6b9591a86810be79818b60c (patch)
tree96f6e09a23071157d5b446853294b4564155ffee /net/sched
parent3f8dc2362fd43a0adee2f6f05bf1ac4d619675b6 (diff)
downloadblackbird-op-linux-06c4648d46d1b757d6b9591a86810be79818b60c.tar.gz
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arp_notify: allow drivers to explicitly request a notification event.
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 Cc: stable@kernel.org Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/sched')
-rw-r--r--net/sched/sch_generic.c18
1 files changed, 18 insertions, 0 deletions
diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index a63029ef3edd..bd1892fe4b21 100644
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -327,6 +327,24 @@ void netif_carrier_off(struct net_device *dev)
}
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.
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