From f495ddc46f97dd0054ff2d5d3c7493d59f7511fb Mon Sep 17 00:00:00 2001 From: Paul Durrant Date: Tue, 8 Oct 2013 14:22:56 +0100 Subject: [PATCH] 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 Cc: David Vrabel Cc: Wei Liu Cc: Ian Campbell Signed-off-by: Greg Kroah-Hartman --- drivers/net/xen-netback/common.h | 1 + drivers/net/xen-netback/interface.c | 12 ++++++++++-- drivers/net/xen-netback/xenbus.c | 17 ++++++++++++----- 3 files changed, 23 insertions(+), 7 deletions(-) diff --git a/drivers/net/xen-netback/common.h b/drivers/net/xen-netback/common.h index 9d7f172..1a28508 100644 --- a/drivers/net/xen-netback/common.h +++ b/drivers/net/xen-netback/common.h @@ -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); diff --git a/drivers/net/xen-netback/interface.c b/drivers/net/xen-netback/interface.c index d984141..3a294c2 100644 --- a/drivers/net/xen-netback/interface.c +++ b/drivers/net/xen-netback/interface.c @@ -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); - unregister_netdev(vif->dev); - xen_netbk_unmap_frontend_rings(vif); +} + +void xenvif_free(struct xenvif *vif) +{ + unregister_netdev(vif->dev); free_netdev(vif->dev); + + module_put(THIS_MODULE); } diff --git a/drivers/net/xen-netback/xenbus.c b/drivers/net/xen-netback/xenbus.c index 410018c..abe24ff 100644 --- a/drivers/net/xen-netback/xenbus.c +++ b/drivers/net/xen-netback/xenbus.c @@ -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) + 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_disconnect(be->vif); + 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); -- 2.7.4