xen-netback: Don't destroy the netdev until the vif is shut down

[ upstream commit id: 279f438e36c0a70b23b86d2090aeec50155034a9 ]

Without this patch, if a frontend cycles through states Closing
and Closed (which Windows frontends need to do) then the netdev
will be destroyed and requires re-invocation of hotplug scripts
to restore state before the frontend can move to Connected. Thus
when udev is not in use the backend gets stuck in InitWait.

With this patch, the netdev is left alone whilst the backend is
still online and is only de-registered and freed just prior to
destroying the vif (which is also nicely symmetrical with the
netdev allocation and registration being done during probe) so
no re-invocation of hotplug scripts is required.

Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Wei Liu <wei.liu2@citrix.com>
Cc: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Paul Durrant 2013-10-08 14:22:56 +01:00 committed by Greg Kroah-Hartman
parent b9396c4c9e
commit f495ddc46f
3 changed files with 24 additions and 8 deletions

View File

@ -115,6 +115,7 @@ struct xenvif *xenvif_alloc(struct device *parent,
int xenvif_connect(struct xenvif *vif, unsigned long tx_ring_ref,
unsigned long rx_ring_ref, unsigned int evtchn);
void xenvif_disconnect(struct xenvif *vif);
void xenvif_free(struct xenvif *vif);
void xenvif_get(struct xenvif *vif);
void xenvif_put(struct xenvif *vif);

View File

@ -304,6 +304,9 @@ struct xenvif *xenvif_alloc(struct device *parent, domid_t domid,
}
netdev_dbg(dev, "Successfully created xenvif\n");
__module_get(THIS_MODULE);
return vif;
}
@ -369,9 +372,14 @@ void xenvif_disconnect(struct xenvif *vif)
if (vif->irq)
unbind_from_irqhandler(vif->irq, vif);
xen_netbk_unmap_frontend_rings(vif);
}
void xenvif_free(struct xenvif *vif)
{
unregister_netdev(vif->dev);
xen_netbk_unmap_frontend_rings(vif);
free_netdev(vif->dev);
module_put(THIS_MODULE);
}

View File

@ -42,7 +42,7 @@ static int netback_remove(struct xenbus_device *dev)
if (be->vif) {
kobject_uevent(&dev->dev.kobj, KOBJ_OFFLINE);
xenbus_rm(XBT_NIL, dev->nodename, "hotplug-status");
xenvif_disconnect(be->vif);
xenvif_free(be->vif);
be->vif = NULL;
}
kfree(be);
@ -203,9 +203,18 @@ static void disconnect_backend(struct xenbus_device *dev)
{
struct backend_info *be = dev_get_drvdata(&dev->dev);
if (be->vif) {
xenbus_rm(XBT_NIL, dev->nodename, "hotplug-status");
if (be->vif)
xenvif_disconnect(be->vif);
}
static void destroy_backend(struct xenbus_device *dev)
{
struct backend_info *be = dev_get_drvdata(&dev->dev);
if (be->vif) {
kobject_uevent(&dev->dev.kobj, KOBJ_OFFLINE);
xenbus_rm(XBT_NIL, dev->nodename, "hotplug-status");
xenvif_free(be->vif);
be->vif = NULL;
}
}
@ -237,14 +246,11 @@ static void frontend_changed(struct xenbus_device *dev,
case XenbusStateConnected:
if (dev->state == XenbusStateConnected)
break;
backend_create_xenvif(be);
if (be->vif)
connect(be);
break;
case XenbusStateClosing:
if (be->vif)
kobject_uevent(&dev->dev.kobj, KOBJ_OFFLINE);
disconnect_backend(dev);
xenbus_switch_state(dev, XenbusStateClosing);
break;
@ -253,6 +259,7 @@ static void frontend_changed(struct xenbus_device *dev,
xenbus_switch_state(dev, XenbusStateClosed);
if (xenbus_dev_is_online(dev))
break;
destroy_backend(dev);
/* fall through if not online */
case XenbusStateUnknown:
device_unregister(&dev->dev);