[Xen-devel] [PATCH v3 1/4] xenbus: move xenbus_dev_shutdown() into frontend code...

[Paul Durrant <pdurrant@xxxxxxxxxx>]

...and make it static

xenbus_dev_shutdown() is seemingly intended to cause clean shutdown of PV
frontends when a guest is rebooted. Indeed the function waits for a
conpletion which is only set by a call to xenbus_frontend_closed().

This patch removes the shutdown() method from backends and moves
xenbus_dev_shutdown() from xenbus_probe.c into xenbus_probe_frontend.c,
renaming it appropriately and making it static.

NOTE: In the case where the backend is running in a driver domain, the
      toolstack should have already terminated any frontends that may be
      using it (since Xen does not support re-startable PV driver domains)
      so xenbus_dev_shutdown() should never be called.

Signed-off-by: Paul Durrant <pdurrant@xxxxxxxxxx>
Reviewed-by: Juergen Gross <jgross@xxxxxxxx>
---
Cc: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>
Cc: Stefano Stabellini <sstabellini@xxxxxxxxxx>
---
 drivers/xen/xenbus/xenbus.h                |  2 --
 drivers/xen/xenbus/xenbus_probe.c          | 23 ---------------------
 drivers/xen/xenbus/xenbus_probe_backend.c  |  1 -
 drivers/xen/xenbus/xenbus_probe_frontend.c | 24 +++++++++++++++++++++-
 4 files changed, 23 insertions(+), 27 deletions(-)

diff --git a/drivers/xen/xenbus/xenbus.h b/drivers/xen/xenbus/xenbus.h
index d75a2385b37c..5f5b8a7d5b80 100644
--- a/drivers/xen/xenbus/xenbus.h
+++ b/drivers/xen/xenbus/xenbus.h
@@ -116,8 +116,6 @@ int xenbus_probe_devices(struct xen_bus_type *bus);
 
 void xenbus_dev_changed(const char *node, struct xen_bus_type *bus);
 
-void xenbus_dev_shutdown(struct device *_dev);
-
 int xenbus_dev_suspend(struct device *dev);
 int xenbus_dev_resume(struct device *dev);
 int xenbus_dev_cancel(struct device *dev);
diff --git a/drivers/xen/xenbus/xenbus_probe.c 
b/drivers/xen/xenbus/xenbus_probe.c
index c21be6e9d38a..5aa29396c9e3 100644
--- a/drivers/xen/xenbus/xenbus_probe.c
+++ b/drivers/xen/xenbus/xenbus_probe.c
@@ -281,29 +281,6 @@ int xenbus_dev_remove(struct device *_dev)
 }
 EXPORT_SYMBOL_GPL(xenbus_dev_remove);
 
-void xenbus_dev_shutdown(struct device *_dev)
-{
-       struct xenbus_device *dev = to_xenbus_device(_dev);
-       unsigned long timeout = 5*HZ;
-
-       DPRINTK("%s", dev->nodename);
-
-       get_device(&dev->dev);
-       if (dev->state != XenbusStateConnected) {
-               pr_info("%s: %s: %s != Connected, skipping\n",
-                       __func__, dev->nodename, xenbus_strstate(dev->state));
-               goto out;
-       }
-       xenbus_switch_state(dev, XenbusStateClosing);
-       timeout = wait_for_completion_timeout(&dev->down, timeout);
-       if (!timeout)
-               pr_info("%s: %s timeout closing device\n",
-                       __func__, dev->nodename);
- out:
-       put_device(&dev->dev);
-}
-EXPORT_SYMBOL_GPL(xenbus_dev_shutdown);
-
 int xenbus_register_driver_common(struct xenbus_driver *drv,
                                  struct xen_bus_type *bus,
                                  struct module *owner, const char *mod_name)
diff --git a/drivers/xen/xenbus/xenbus_probe_backend.c 
b/drivers/xen/xenbus/xenbus_probe_backend.c
index b0bed4faf44c..14876faff3b0 100644
--- a/drivers/xen/xenbus/xenbus_probe_backend.c
+++ b/drivers/xen/xenbus/xenbus_probe_backend.c
@@ -198,7 +198,6 @@ static struct xen_bus_type xenbus_backend = {
                .uevent         = xenbus_uevent_backend,
                .probe          = xenbus_dev_probe,
                .remove         = xenbus_dev_remove,
-               .shutdown       = xenbus_dev_shutdown,
                .dev_groups     = xenbus_dev_groups,
        },
 };
diff --git a/drivers/xen/xenbus/xenbus_probe_frontend.c 
b/drivers/xen/xenbus/xenbus_probe_frontend.c
index a7d90a719cea..8a1650bbe18f 100644
--- a/drivers/xen/xenbus/xenbus_probe_frontend.c
+++ b/drivers/xen/xenbus/xenbus_probe_frontend.c
@@ -126,6 +126,28 @@ static int xenbus_frontend_dev_probe(struct device *dev)
        return xenbus_dev_probe(dev);
 }
 
+static void xenbus_frontend_dev_shutdown(struct device *_dev)
+{
+       struct xenbus_device *dev = to_xenbus_device(_dev);
+       unsigned long timeout = 5*HZ;
+
+       DPRINTK("%s", dev->nodename);
+
+       get_device(&dev->dev);
+       if (dev->state != XenbusStateConnected) {
+               pr_info("%s: %s: %s != Connected, skipping\n",
+                       __func__, dev->nodename, xenbus_strstate(dev->state));
+               goto out;
+       }
+       xenbus_switch_state(dev, XenbusStateClosing);
+       timeout = wait_for_completion_timeout(&dev->down, timeout);
+       if (!timeout)
+               pr_info("%s: %s timeout closing device\n",
+                       __func__, dev->nodename);
+ out:
+       put_device(&dev->dev);
+}
+
 static const struct dev_pm_ops xenbus_pm_ops = {
        .suspend        = xenbus_dev_suspend,
        .resume         = xenbus_frontend_dev_resume,
@@ -146,7 +168,7 @@ static struct xen_bus_type xenbus_frontend = {
                .uevent         = xenbus_uevent_frontend,
                .probe          = xenbus_frontend_dev_probe,
                .remove         = xenbus_dev_remove,
-               .shutdown       = xenbus_dev_shutdown,
+               .shutdown       = xenbus_frontend_dev_shutdown,
                .dev_groups     = xenbus_dev_groups,
 
                .pm             = &xenbus_pm_ops,
-- 
2.20.1


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/xen-devel