s390/ccwgroup: release the cdevs from within dev->release()

Wiring up the cdevs is an essential part of the gdev creation. So
release them during the gdev destruction, ie. on the last put_device().
This could cause us to hold on to the cdevs a tiny bit longer, but
that's not a real concern.

As we have much less certainty of what context this put_device() is
executed from, switch to irqsave locking.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

diff --git a/drivers/s390/cio/ccwgroup.c b/drivers/s390/cio/ccwgroup.c
index 444385d..49f816c 100644 (file)
--- a/drivers/s390/cio/ccwgroup.c
+++ b/drivers/s390/cio/ccwgroup.c
@@ -45,27 +45,6 @@ static void __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);
-       }
-}
-
 /**
  * ccwgroup_set_online() - enable a ccwgroup device
  * @gdev: target ccwgroup device
@@ -175,7 +154,6 @@ static void ccwgroup_ungroup(struct ccwgroup_device *gdev)
        if (device_is_registered(&gdev->dev)) {
                __ccwgroup_remove_symlinks(gdev);
                device_unregister(&gdev->dev);
-               __ccwgroup_remove_cdev_refs(gdev);
        }
        mutex_unlock(&gdev->reg_mutex);
 }
@@ -228,7 +206,23 @@ static void ccwgroup_ungroup_workfn(struct work_struct *work)
 
 static void ccwgroup_release(struct device *dev)
 {
-       kfree(to_ccwgroupdev(dev));
+       struct ccwgroup_device *gdev = to_ccwgroupdev(dev);
+       unsigned int i;
+
+       for (i = 0; i < gdev->count; i++) {
+               struct ccw_device *cdev = gdev->cdev[i];
+               unsigned long flags;
+
+               if (cdev) {
+                       spin_lock_irqsave(cdev->ccwlock, flags);
+                       if (dev_get_drvdata(&cdev->dev) == gdev)
+                               dev_set_drvdata(&cdev->dev, NULL);
+                       spin_unlock_irqrestore(cdev->ccwlock, flags);
+                       put_device(&cdev->dev);
+               }
+       }
+
+       kfree(gdev);
 }
 
 static int __ccwgroup_create_symlinks(struct ccwgroup_device *gdev)
@@ -396,15 +390,6 @@ int ccwgroup_create_dev(struct device *parent, struct ccwgroup_driver *gdrv,
        mutex_unlock(&gdev->reg_mutex);
        return 0;
 error:
-       for (i = 0; i < num_devices; 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);
-                       gdev->cdev[i] = NULL;
-               }
        mutex_unlock(&gdev->reg_mutex);
        put_device(&gdev->dev);
        return rc;