[PULL 4/6] block/qcow2: zero data_file child after free

[Max Reitz]

From: Vladimir Sementsov-Ogievskiy <address@hidden>

data_file being NULL doesn't seem to be a correct state, but it's
better than dead pointer and simpler to debug.

Signed-off-by: Vladimir Sementsov-Ogievskiy <address@hidden>
Message-Id: <address@hidden>
Reviewed-by: John Snow <address@hidden>
Signed-off-by: Max Reitz <address@hidden>
---
 block/qcow2.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/block/qcow2.c b/block/qcow2.c
index e08917ed84..d1da3d91db 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -1758,6 +1758,7 @@ static int coroutine_fn qcow2_do_open(BlockDriverState 
*bs, QDict *options,
     g_free(s->image_data_file);
     if (has_data_file(bs)) {
         bdrv_unref_child(bs, s->data_file);
+        s->data_file = NULL;
     }
     g_free(s->unknown_header_fields);
     cleanup_unknown_header_ext(bs);
@@ -2621,6 +2622,7 @@ static void qcow2_close(BlockDriverState *bs)
 
     if (has_data_file(bs)) {
         bdrv_unref_child(bs, s->data_file);
+        s->data_file = NULL;
     }
 
     qcow2_refcount_close(bs);
-- 
2.25.1