--- a/drivers/block/loop.c 2010-07-02 15:58:02.000000000 -0700
+++ a/drivers/block/loop.c 2010-07-23 10:30:17.000000000 -0700
@@ -899,6 +899,7 @@

	wait_for_completion(&lo->lo_done);

+ lo->lo_queue->unplug_fn = NULL;
	lo->lo_backing_file = NULL;

	loop_release_xfer(lo);