diff options
| author | Ian Campbell <Ian.Campbell@citrix.com> | 2010-05-26 00:09:42 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2010-08-13 13:19:49 -0700 |
| commit | ac33b999caed81edf848948cde358920dff3f31f (patch) | |
| tree | aa5768e332f2c459ac4ec3b579feb990e1e523ae | |
| parent | bdded112e09f6c94084fe6c69ebbfb561650a046 (diff) | |
arp_notify: allow drivers to explicitly request a notification event.
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>
| -rw-r--r-- | include/linux/netdevice.h | 2 | ||||
| -rw-r--r-- | include/linux/notifier.h | 1 | ||||
| -rw-r--r-- | net/ipv4/devinet.c | 1 | ||||
| -rw-r--r-- | net/sched/sch_generic.c | 18 |
4 files changed, 22 insertions, 0 deletions
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 812a5f3c2ab..ec12f8c2477 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -1560,6 +1560,8 @@ extern void netif_carrier_on(struct net_device *dev); 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 diff --git a/include/linux/notifier.h b/include/linux/notifier.h index 44428d247db..b1302a6bdd2 100644 --- a/include/linux/notifier.h +++ b/include/linux/notifier.h @@ -201,6 +201,7 @@ static inline int notifier_to_errno(int ret) #define NETDEV_PRE_UP 0x000D #define NETDEV_BONDING_OLDTYPE 0x000E #define NETDEV_BONDING_NEWTYPE 0x000F +#define NETDEV_NOTIFY_PEERS 0x0012 #define SYS_DOWN 0x0001 /* Notify of system down */ #define SYS_RESTART SYS_DOWN diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c index cc35645d910..f84f6dd0a32 100644 --- a/net/ipv4/devinet.c +++ b/net/ipv4/devinet.c @@ -1076,6 +1076,7 @@ static int inetdev_event(struct notifier_block *this, unsigned long event, } 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)) { diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c index 4ae6aa562f2..30280017b05 100644 --- a/net/sched/sch_generic.c +++ b/net/sched/sch_generic.c @@ -330,6 +330,24 @@ 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. |