From 279f438e36c0a70b23b86d2090aeec50155034a9 Mon Sep 17 00:00:00 2001 From: Paul Durrant Date: Tue, 17 Sep 2013 17:46:08 +0100 Subject: [PATCH] xen-netback: Don't destroy the netdev until the vif is shut down 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 Acked-by: Wei Liu Signed-off-by: David S. Miller --- drivers/net/xen-netback/common.h | 1 + drivers/net/xen-netback/interface.c | 26 ++++++++++---------------- drivers/net/xen-netback/xenbus.c | 17 ++++++++++++----- 3 files changed, 23 insertions(+), 21 deletions(-) diff --git a/drivers/net/xen-netback/common.h b/drivers/net/xen-netback/common.h index a1977430ddfb..5715318d6bab 100644 --- a/drivers/net/xen-netback/common.h +++ b/drivers/net/xen-netback/common.h @@ -184,6 +184,7 @@ int xenvif_connect(struct xenvif *vif, unsigned long tx_ring_ref, unsigned long rx_ring_ref, unsigned int tx_evtchn, unsigned int rx_evtchn); void xenvif_disconnect(struct xenvif *vif); +void xenvif_free(struct xenvif *vif); int xenvif_xenbus_init(void); void xenvif_xenbus_fini(void); diff --git a/drivers/net/xen-netback/interface.c b/drivers/net/xen-netback/interface.c index 77fee1d51fb2..01bb854c7f62 100644 --- a/drivers/net/xen-netback/interface.c +++ b/drivers/net/xen-netback/interface.c @@ -353,6 +353,9 @@ struct xenvif *xenvif_alloc(struct device *parent, domid_t domid, } netdev_dbg(dev, "Successfully created xenvif\n"); + + __module_get(THIS_MODULE); + return vif; } @@ -366,8 +369,6 @@ int xenvif_connect(struct xenvif *vif, unsigned long tx_ring_ref, if (vif->tx_irq) return 0; - __module_get(THIS_MODULE); - err = xenvif_map_frontend_rings(vif, tx_ring_ref, rx_ring_ref); if (err < 0) goto err; @@ -452,12 +453,6 @@ void xenvif_carrier_off(struct xenvif *vif) void xenvif_disconnect(struct xenvif *vif) { - /* Disconnect funtion might get called by generic framework - * even before vif connects, so we need to check if we really - * need to do a module_put. - */ - int need_module_put = 0; - if (netif_carrier_ok(vif->dev)) xenvif_carrier_off(vif); @@ -468,23 +463,22 @@ void xenvif_disconnect(struct xenvif *vif) unbind_from_irqhandler(vif->tx_irq, vif); unbind_from_irqhandler(vif->rx_irq, vif); } - /* vif->irq is valid, we had a module_get in - * xenvif_connect. - */ - need_module_put = 1; + vif->tx_irq = 0; } if (vif->task) kthread_stop(vif->task); + xenvif_unmap_frontend_rings(vif); +} + +void xenvif_free(struct xenvif *vif) +{ netif_napi_del(&vif->napi); unregister_netdev(vif->dev); - xenvif_unmap_frontend_rings(vif); - free_netdev(vif->dev); - if (need_module_put) - module_put(THIS_MODULE); + module_put(THIS_MODULE); } diff --git a/drivers/net/xen-netback/xenbus.c b/drivers/net/xen-netback/xenbus.c index 1fe48fe364ed..a53782ef1540 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); @@ -213,9 +213,18 @@ 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; } } @@ -246,14 +255,11 @@ 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; @@ -262,6 +268,7 @@ 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); -- 2.30.2