[PATCH] xen/netback: refactor xenvif_carrier_on from xenvif_connect

From: Ian Campbell
Date: Tue Feb 19 2013 - 05:46:12 EST


Several people have been confused by the vif reference count taken by
xenvif_connect() being dropped in xenvif_carrier_off(). Factor out bringing
the carrier up (and the associated reference grab) to try and make the
relationship more obvious.

Signed-off-by: Ian Campbell <ian.campbell@xxxxxxxxxx>
---
drivers/net/xen-netback/interface.c | 49 +++++++++++++++++++---------------
1 files changed, 27 insertions(+), 22 deletions(-)

diff --git a/drivers/net/xen-netback/interface.c b/drivers/net/xen-netback/interface.c
index d984141..059d726 100644
--- a/drivers/net/xen-netback/interface.c
+++ b/drivers/net/xen-netback/interface.c
@@ -307,6 +307,32 @@ struct xenvif *xenvif_alloc(struct device *parent, domid_t domid,
return vif;
}

+static void xenvif_carrier_on(struct xenvif *vif)
+{
+ xenvif_get(vif);
+
+ rtnl_lock();
+ if (!vif->can_sg && vif->dev->mtu > ETH_DATA_LEN)
+ dev_set_mtu(vif->dev, ETH_DATA_LEN);
+ netdev_update_features(vif->dev);
+ netif_carrier_on(vif->dev);
+ if (netif_running(vif->dev))
+ xenvif_up(vif);
+ rtnl_unlock();
+}
+
+void xenvif_carrier_off(struct xenvif *vif)
+{
+ struct net_device *dev = vif->dev;
+
+ rtnl_lock();
+ netif_carrier_off(dev); /* discard queued packets */
+ if (netif_running(dev))
+ xenvif_down(vif);
+ rtnl_unlock();
+ xenvif_put(vif);
+}
+
int xenvif_connect(struct xenvif *vif, unsigned long tx_ring_ref,
unsigned long rx_ring_ref, unsigned int evtchn)
{
@@ -328,16 +354,7 @@ int xenvif_connect(struct xenvif *vif, unsigned long tx_ring_ref,
vif->irq = err;
disable_irq(vif->irq);

- xenvif_get(vif);
-
- rtnl_lock();
- if (!vif->can_sg && vif->dev->mtu > ETH_DATA_LEN)
- dev_set_mtu(vif->dev, ETH_DATA_LEN);
- netdev_update_features(vif->dev);
- netif_carrier_on(vif->dev);
- if (netif_running(vif->dev))
- xenvif_up(vif);
- rtnl_unlock();
+ xenvif_carrier_on(vif);

return 0;
err_unmap:
@@ -346,18 +363,6 @@ err:
return err;
}

-void xenvif_carrier_off(struct xenvif *vif)
-{
- struct net_device *dev = vif->dev;
-
- rtnl_lock();
- netif_carrier_off(dev); /* discard queued packets */
- if (netif_running(dev))
- xenvif_down(vif);
- rtnl_unlock();
- xenvif_put(vif);
-}
-
void xenvif_disconnect(struct xenvif *vif)
{
if (netif_carrier_ok(vif->dev))
--
1.7.2.5



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