* Re: [PATCH] xen-netback: Don't destroy the netdev until the vif is shut
@ 2013-10-04 4:22 David Miller
2013-10-04 14:23 ` Paul Durrant
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: David Miller @ 2013-10-04 4:22 UTC (permalink / raw)
To: Paul.Durrant; +Cc: netdev, wei.liu2
Can one of you do -stable backports of this change for v3.11 and any
other active -stable branch where this fix is relevant?
I gave it a shot, and it got outside my realm of expertise.
Thanks!
^ permalink raw reply [flat|nested] 4+ messages in thread
* RE: [PATCH] xen-netback: Don't destroy the netdev until the vif is shut
2013-10-04 4:22 [PATCH] xen-netback: Don't destroy the netdev until the vif is shut David Miller
@ 2013-10-04 14:23 ` Paul Durrant
2013-10-08 14:39 ` Paul Durrant
2013-10-08 14:41 ` Paul Durrant
2 siblings, 0 replies; 4+ messages in thread
From: Paul Durrant @ 2013-10-04 14:23 UTC (permalink / raw)
To: David Miller; +Cc: netdev, Wei Liu
> -----Original Message-----
> From: David Miller [mailto:davem@davemloft.net]
> Sent: 04 October 2013 05:23
> To: Paul Durrant
> Cc: netdev@vger.kernel.org; Wei Liu
> Subject: Re: [PATCH] xen-netback: Don't destroy the netdev until the vif is
> shut
>
>
> Can one of you do -stable backports of this change for v3.11 and any
> other active -stable branch where this fix is relevant?
>
Ok. Will do.
Paul
> I gave it a shot, and it got outside my realm of expertise.
>
> Thanks!
^ permalink raw reply [flat|nested] 4+ messages in thread
* RE: [PATCH] xen-netback: Don't destroy the netdev until the vif is shut
2013-10-04 4:22 [PATCH] xen-netback: Don't destroy the netdev until the vif is shut David Miller
2013-10-04 14:23 ` Paul Durrant
@ 2013-10-08 14:39 ` Paul Durrant
2013-10-08 14:41 ` Paul Durrant
2 siblings, 0 replies; 4+ messages in thread
From: Paul Durrant @ 2013-10-08 14:39 UTC (permalink / raw)
To: David Miller; +Cc: netdev, Wei Liu
> -----Original Message-----
> From: David Miller [mailto:davem@davemloft.net]
> Sent: 04 October 2013 05:23
> To: Paul Durrant
> Cc: netdev@vger.kernel.org; Wei Liu
> Subject: Re: [PATCH] xen-netback: Don't destroy the netdev until the vif is
> shut
>
>
> Can one of you do -stable backports of this change for v3.11 and any
> other active -stable branch where this fix is relevant?
>
> I gave it a shot, and it got outside my realm of expertise.
>
> Thanks!
Ok. Here's a backport to 3.11.
Paul
--8<--
>From 158011889a79ad7cebdd30d551adcfeae80b8989 Mon Sep 17 00:00:00 2001
From: Paul Durrant <paul.durrant@citrix.com>
Date: Tue, 8 Oct 2013 14:56:44 +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 <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>
---
drivers/net/xen-netback/common.h | 1 +
drivers/net/xen-netback/interface.c | 23 +++++++++--------------
drivers/net/xen-netback/xenbus.c | 17 ++++++++++++-----
3 files changed, 22 insertions(+), 19 deletions(-)
diff --git a/drivers/net/xen-netback/common.h b/drivers/net/xen-netback/common.h
index 8a4d77e..4d9a5e7 100644
--- a/drivers/net/xen-netback/common.h
+++ b/drivers/net/xen-netback/common.h
@@ -120,6 +120,7 @@ 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);
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 087d2db..73336c1 100644
--- a/drivers/net/xen-netback/interface.c
+++ b/drivers/net/xen-netback/interface.c
@@ -326,6 +326,9 @@ struct xenvif *xenvif_alloc(struct device *parent, domid_t domid,
}
netdev_dbg(dev, "Successfully created xenvif\n");
+
+ __module_get(THIS_MODULE);
+
return vif;
}
@@ -413,12 +416,6 @@ 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);
@@ -432,18 +429,16 @@ 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;
}
- unregister_netdev(vif->dev);
-
xen_netbk_unmap_frontend_rings(vif);
+}
+
+void xenvif_free(struct xenvif *vif)
+{
+ unregister_netdev(vif->dev);
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 1fe48fe3..a53782e 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);
--
1.7.10.4
^ permalink raw reply related [flat|nested] 4+ messages in thread
* RE: [PATCH] xen-netback: Don't destroy the netdev until the vif is shut
2013-10-04 4:22 [PATCH] xen-netback: Don't destroy the netdev until the vif is shut David Miller
2013-10-04 14:23 ` Paul Durrant
2013-10-08 14:39 ` Paul Durrant
@ 2013-10-08 14:41 ` Paul Durrant
2 siblings, 0 replies; 4+ messages in thread
From: Paul Durrant @ 2013-10-08 14:41 UTC (permalink / raw)
To: David Miller; +Cc: netdev, Wei Liu
> -----Original Message-----
> From: David Miller [mailto:davem@davemloft.net]
> Sent: 04 October 2013 05:23
> To: Paul Durrant
> Cc: netdev@vger.kernel.org; Wei Liu
> Subject: Re: [PATCH] xen-netback: Don't destroy the netdev until the vif is
> shut
>
>
> Can one of you do -stable backports of this change for v3.11 and any
> other active -stable branch where this fix is relevant?
>
> I gave it a shot, and it got outside my realm of expertise.
>
> Thanks!
Here is a patch for 3.10.
--8<--
>From e626fc73f445f05d976756d022614f06461cab74 Mon Sep 17 00:00:00 2001
From: Paul Durrant <paul.durrant@citrix.com>
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 <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>
---
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);
--
1.7.10.4
^ permalink raw reply related [flat|nested] 4+ messages in thread
end of thread, other threads:[~2013-10-08 14:42 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2013-10-04 4:22 [PATCH] xen-netback: Don't destroy the netdev until the vif is shut David Miller
2013-10-04 14:23 ` Paul Durrant
2013-10-08 14:39 ` Paul Durrant
2013-10-08 14:41 ` Paul Durrant
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).