Index: linux-2.6/fs/locks.c
===================================================================
--- linux-2.6.orig/fs/locks.c
+++ linux-2.6/fs/locks.c
@@ -147,7 +147,14 @@ static struct kmem_cache *filelock_cache
 /* Allocate an empty lock structure. */
 static struct file_lock *locks_alloc_lock(void)
 {
-	return kmem_cache_alloc(filelock_cache, GFP_KERNEL);
+	struct file_lock *fl;
+	fl = kmem_cache_alloc(filelock_cache, GFP_KERNEL);
+	if (fl) {
+		BUG_ON(waitqueue_active(&fl->fl_wait));
+		BUG_ON(!list_empty(&fl->fl_block));
+		BUG_ON(!list_empty(&fl->fl_link));
+	}
+	return fl;
 }
 
 static void locks_release_private(struct file_lock *fl)