releases/2.6.32.3/xen-fix-is_disconnected_device-exists_disconnected_device.patch

   1 From c6e1971139be1342902873181f3b80a979bfb33b Mon Sep 17 00:00:00 2001
   2 From: Paolo Bonzini <pbonzini@redhat.com>
   3 Date: Wed, 8 Jul 2009 12:27:37 +0200
   4 Subject: xen: fix is_disconnected_device/exists_disconnected_device
   5
   6 From: Paolo Bonzini <pbonzini@redhat.com>
   7
   8 commit c6e1971139be1342902873181f3b80a979bfb33b upstream.
   9
  10 The logic of is_disconnected_device/exists_disconnected_device is wrong
  11 in that they are used to test whether a device is trying to connect (i.e.
  12 connecting).  For this reason the patch fixes them to not consider a
  13 Closing or Closed device to be connecting.  At the same time the patch
  14 also renames the functions according to what they really do; you could
  15 say a closed device is "disconnected" (the old name), but not "connecting"
  16 (the new name).
  17
  18 This patch is a backport of changeset 909 from the Xenbits tree.
  19
  20 Cc: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
  21 Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
  22 Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
  23 Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
  24
  25 ---
  26  drivers/xen/xenbus/xenbus_probe.c |   13 +++++++------
  27  1 file changed, 7 insertions(+), 6 deletions(-)
  28
  29 --- a/drivers/xen/xenbus/xenbus_probe.c
  30 +++ b/drivers/xen/xenbus/xenbus_probe.c
  31 @@ -843,7 +843,7 @@ postcore_initcall(xenbus_probe_init);
  32
  33  MODULE_LICENSE("GPL");
  34
  35 -static int is_disconnected_device(struct device *dev, void *data)
  36 +static int is_device_connecting(struct device *dev, void *data)
  37  {
  38         struct xenbus_device *xendev = to_xenbus_device(dev);
  39         struct device_driver *drv = data;
  40 @@ -861,14 +861,15 @@ static int is_disconnected_device(struct
  41                 return 0;
  42
  43         xendrv = to_xenbus_driver(dev->driver);
  44 -       return (xendev->state != XenbusStateConnected ||
  45 -               (xendrv->is_ready && !xendrv->is_ready(xendev)));
  46 +       return (xendev->state < XenbusStateConnected ||
  47 +               (xendev->state == XenbusStateConnected &&
  48 +                xendrv->is_ready && !xendrv->is_ready(xendev)));
  49  }
  50
  51 -static int exists_disconnected_device(struct device_driver *drv)
  52 +static int exists_connecting_device(struct device_driver *drv)
  53  {
  54         return bus_for_each_dev(&xenbus_frontend.bus, NULL, drv,
  55 -                               is_disconnected_device);
  56 +                               is_device_connecting);
  57  }
  58
  59  static int print_device_status(struct device *dev, void *data)
  60 @@ -918,7 +919,7 @@ static void wait_for_devices(struct xenb
  61         if (!ready_to_wait_for_devices || !xen_domain())
  62                 return;
  63
  64 -       while (exists_disconnected_device(drv)) {
  65 +       while (exists_connecting_device(drv)) {
  66                 if (time_after(jiffies, timeout))
  67                         break;
  68                 schedule_timeout_interruptible(HZ/10);