src/patches/suse-2.6.27.31/patches.arch/s390-10-10-ccwgroup_fix_unbind.patch

   1 From: Gerald Schaefer <geraldsc@de.ibm.com>
   2 Subject: cio: ccwgroup - fix unbind behaviour
   3 References: bnc#482818,LTC#52098
   4
   5 Symptom:     Oops after unbinding a ccwgroup device.
   6 Problem:     There is no special callback to tell a driver to unbind
   7              a device - the normal remove is called. In this case
   8              the device remains partly registered in the driver core.
   9 Solution:    Use a bus notifier function to handle this special case
  10              and call ungroup since this virtual device can not exist
  11              without a driver.
  12
  13 Acked-by: John Jolly <jjolly@suse.de>
  14 ---
  15  drivers/s390/cio/ccwgroup.c |   73 +++++++++++++++++++++++++++++++++-----------
  16  1 file changed, 56 insertions(+), 17 deletions(-)
  17
  18 Index: linux-sles11/drivers/s390/cio/ccwgroup.c
  19 ===================================================================
  20 --- linux-sles11.orig/drivers/s390/cio/ccwgroup.c       2009-03-09 15:36:56.000000000 +0100
  21 +++ linux-sles11/drivers/s390/cio/ccwgroup.c    2009-03-09 15:53:56.000000000 +0100
  22 @@ -313,16 +313,32 @@ error:
  23  }
  24  EXPORT_SYMBOL(ccwgroup_create_from_string);
  25
  26 -static int __init
  27 -init_ccwgroup (void)
  28 +static int ccwgroup_notifier(struct notifier_block *nb, unsigned long action,
  29 +                            void *data);
  30 +
  31 +static struct notifier_block ccwgroup_nb = {
  32 +       .notifier_call = ccwgroup_notifier
  33 +};
  34 +
  35 +static int __init init_ccwgroup(void)
  36  {
  37 -       return bus_register (&ccwgroup_bus_type);
  38 +       int ret;
  39 +
  40 +       ret = bus_register(&ccwgroup_bus_type);
  41 +       if (ret)
  42 +               return ret;
  43 +
  44 +       ret = bus_register_notifier(&ccwgroup_bus_type, &ccwgroup_nb);
  45 +       if (ret)
  46 +               bus_unregister(&ccwgroup_bus_type);
  47 +
  48 +       return ret;
  49  }
  50
  51 -static void __exit
  52 -cleanup_ccwgroup (void)
  53 +static void __exit cleanup_ccwgroup(void)
  54  {
  55 -       bus_unregister (&ccwgroup_bus_type);
  56 +       bus_unregister_notifier(&ccwgroup_bus_type, &ccwgroup_nb);
  57 +       bus_unregister(&ccwgroup_bus_type);
  58  }
  59
  60  module_init(init_ccwgroup);
  61 @@ -390,27 +406,28 @@ ccwgroup_online_store (struct device *de
  62         unsigned long value;
  63         int ret;
  64
  65 -       gdev = to_ccwgroupdev(dev);
  66         if (!dev->driver)
  67 -               return count;
  68 +               return -ENODEV;
  69 +
  70 +       gdev = to_ccwgroupdev(dev);
  71 +       gdrv = to_ccwgroupdrv(dev->driver);
  72
  73 -       gdrv = to_ccwgroupdrv (gdev->dev.driver);
  74         if (!try_module_get(gdrv->owner))
  75                 return -EINVAL;
  76
  77         ret = strict_strtoul(buf, 0, &value);
  78         if (ret)
  79                 goto out;
  80 -       ret = count;
  81 +
  82         if (value == 1)
  83 -               ccwgroup_set_online(gdev);
  84 +               ret = ccwgroup_set_online(gdev);
  85         else if (value == 0)
  86 -               ccwgroup_set_offline(gdev);
  87 +               ret = ccwgroup_set_offline(gdev);
  88         else
  89                 ret = -EINVAL;
  90  out:
  91         module_put(gdrv->owner);
  92 -       return ret;
  93 +       return (ret == 0) ? count : ret;
  94  }
  95
  96  static ssize_t
  97 @@ -452,13 +469,18 @@ ccwgroup_remove (struct device *dev)
  98         struct ccwgroup_device *gdev;
  99         struct ccwgroup_driver *gdrv;
 100
 101 +       device_remove_file(dev, &dev_attr_online);
 102 +       device_remove_file(dev, &dev_attr_ungroup);
 103 +
 104 +       if (!dev->driver)
 105 +               return 0;
 106 +
 107         gdev = to_ccwgroupdev(dev);
 108         gdrv = to_ccwgroupdrv(dev->driver);
 109
 110 -       device_remove_file(dev, &dev_attr_online);
 111 -
 112 -       if (gdrv && gdrv->remove)
 113 +       if (gdrv->remove)
 114                 gdrv->remove(gdev);
 115 +
 116         return 0;
 117  }
 118
 119 @@ -467,9 +489,13 @@ static void ccwgroup_shutdown(struct dev
 120         struct ccwgroup_device *gdev;
 121         struct ccwgroup_driver *gdrv;
 122
 123 +       if (!dev->driver)
 124 +               return;
 125 +
 126         gdev = to_ccwgroupdev(dev);
 127         gdrv = to_ccwgroupdrv(dev->driver);
 128 -       if (gdrv && gdrv->shutdown)
 129 +
 130 +       if (gdrv->shutdown)
 131                 gdrv->shutdown(gdev);
 132  }
 133
 134 @@ -482,6 +508,19 @@ static struct bus_type ccwgroup_bus_type
 135         .shutdown = ccwgroup_shutdown,
 136  };
 137
 138 +
 139 +static int ccwgroup_notifier(struct notifier_block *nb, unsigned long action,
 140 +                            void *data)
 141 +{
 142 +       struct device *dev = data;
 143 +
 144 +       if (action == BUS_NOTIFY_UNBIND_DRIVER)
 145 +               device_schedule_callback(dev, ccwgroup_ungroup_callback);
 146 +
 147 +       return NOTIFY_OK;
 148 +}
 149 +
 150 +
 151  /**
 152   * ccwgroup_driver_register() - register a ccw group driver
 153   * @cdriver: driver to be registered