1 files changed, 40 insertions, 38 deletions

diff --git a/drivers/s390/cio/ccwgroup.c b/drivers/s390/cio/ccwgroup.c
index 97b25d68e3e..2864581d8ec 100644
--- a/drivers/s390/cio/ccwgroup.c
+++ b/drivers/s390/cio/ccwgroup.c
@@ -67,6 +67,27 @@ __ccwgroup_remove_symlinks(struct ccwgroup_device *gdev)
 }
 
 /*
+ * Remove references from ccw devices to ccw group device and from
+ * ccw group device to ccw devices.
+ */
+static void __ccwgroup_remove_cdev_refs(struct ccwgroup_device *gdev)
+{
+        struct ccw_device *cdev;
+        int i;
+
+        for (i = 0; i < gdev->count; i++) {
+                cdev = gdev->cdev[i];
+                if (!cdev)
+                        continue;
+                spin_lock_irq(cdev->ccwlock);
+                dev_set_drvdata(&cdev->dev, NULL);
+                spin_unlock_irq(cdev->ccwlock);
+                gdev->cdev[i] = NULL;
+                put_device(&cdev->dev);
+        }
+}
+
+/*
  * Provide an 'ungroup' attribute so the user can remove group devices no
  * longer needed or accidentially created. Saves memory :)
  */
@@ -78,6 +99,7 @@ static void ccwgroup_ungroup_callback(struct device *dev)
         if (device_is_registered(&gdev->dev)) {
                 __ccwgroup_remove_symlinks(gdev);
                 device_unregister(dev);
+                __ccwgroup_remove_cdev_refs(gdev);
         }
         mutex_unlock(&gdev->reg_mutex);
 }
@@ -116,21 +138,7 @@ static DEVICE_ATTR(ungroup, 0200, NULL, ccwgroup_ungroup_store);
 static void
 ccwgroup_release (struct device *dev)
 {
-        struct ccwgroup_device *gdev;
-        int i;
-
-        gdev = to_ccwgroupdev(dev);
-
-        for (i = 0; i < gdev->count; i++) {
-                if (gdev->cdev[i]) {
-                        spin_lock_irq(gdev->cdev[i]->ccwlock);
-                        if (dev_get_drvdata(&gdev->cdev[i]->dev) == gdev)
-                                dev_set_drvdata(&gdev->cdev[i]->dev, NULL);
-                        spin_unlock_irq(gdev->cdev[i]->ccwlock);
-                        put_device(&gdev->cdev[i]->dev);
-                }
-        }
-        kfree(gdev);
+        kfree(to_ccwgroupdev(dev));
 }
 
 static int
@@ -639,6 +647,7 @@ void ccwgroup_driver_unregister(struct ccwgroup_driver *cdriver)
                 mutex_lock(&gdev->reg_mutex);
                 __ccwgroup_remove_symlinks(gdev);
                 device_unregister(dev);
+                __ccwgroup_remove_cdev_refs(gdev);
                 mutex_unlock(&gdev->reg_mutex);
                 put_device(dev);
         }
@@ -660,25 +669,6 @@ int ccwgroup_probe_ccwdev(struct ccw_device *cdev)
         return 0;
 }
 
-static struct ccwgroup_device *
-__ccwgroup_get_gdev_by_cdev(struct ccw_device *cdev)
-{
-        struct ccwgroup_device *gdev;
-
-        gdev = dev_get_drvdata(&cdev->dev);
-        if (gdev) {
-                if (get_device(&gdev->dev)) {
-                        mutex_lock(&gdev->reg_mutex);
-                        if (device_is_registered(&gdev->dev))
-                                return gdev;
-                        mutex_unlock(&gdev->reg_mutex);
-                        put_device(&gdev->dev);
-                }
-                return NULL;
-        }
-        return NULL;
-}
-
 /**
  * ccwgroup_remove_ccwdev() - remove function for slave devices
  * @cdev: ccw device to be removed
@@ -694,13 +684,25 @@ void ccwgroup_remove_ccwdev(struct ccw_device *cdev)
         /* Ignore offlining errors, device is gone anyway. */
         ccw_device_set_offline(cdev);
         /* If one of its devices is gone, the whole group is done for. */
-        gdev = __ccwgroup_get_gdev_by_cdev(cdev);
-        if (gdev) {
+        spin_lock_irq(cdev->ccwlock);
+        gdev = dev_get_drvdata(&cdev->dev);
+        if (!gdev) {
+                spin_unlock_irq(cdev->ccwlock);
+                return;
+        }
+        /* Get ccwgroup device reference for local processing. */
+        get_device(&gdev->dev);
+        spin_unlock_irq(cdev->ccwlock);
+        /* Unregister group device. */
+        mutex_lock(&gdev->reg_mutex);
+        if (device_is_registered(&gdev->dev)) {
                 __ccwgroup_remove_symlinks(gdev);
                 device_unregister(&gdev->dev);
-                mutex_unlock(&gdev->reg_mutex);
-                put_device(&gdev->dev);
+                __ccwgroup_remove_cdev_refs(gdev);
         }
+        mutex_unlock(&gdev->reg_mutex);
+        /* Release ccwgroup device reference for local processing. */
+        put_device(&gdev->dev);
 }
 
 MODULE_LICENSE("GPL");