[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>

1 files changed, 7 insertions, 2 deletions

diff --git a/drivers/s390/block/dcssblk.c b/drivers/s390/block/dcssblk.c
index 859f870552..5e083d1f57 100644
--- 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;