[S390] device_schedule_callback() for dcssblk.

Unregistering a device from within a device attribute handler leads to
a deadlock. Need to use device_schedule_callback() to unregister device
in error path.

Signed-off-by: Gerald Schaefer <geraldsc@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

diff --git a/drivers/s390/block/dcssblk.c b/drivers/s390/block/dcssblk.c
index 859f870..5e083d1 100644 (file)
--- a/drivers/s390/block/dcssblk.c
+++ b/drivers/s390/block/dcssblk.c
@@ -193,6 +193,12 @@ dcssblk_segment_warn(int rc, char* seg_name)
        }
 }
 
+static void dcssblk_unregister_callback(struct device *dev)
+{
+       device_unregister(dev);
+       put_device(dev);
+}
+
 /*
  * device attribute for switching shared/nonshared (exclusive)
  * operation (show + store)
@@ -276,8 +282,7 @@ removeseg:
        blk_cleanup_queue(dev_info->dcssblk_queue);
        dev_info->gd->queue = NULL;
        put_disk(dev_info->gd);
-       device_unregister(dev);
-       put_device(dev);
+       rc = device_schedule_callback(dev, dcssblk_unregister_callback);
 out:
        up_write(&dcssblk_devices_sem);
        return rc;