block: Convert bs->file to BdrvChild

This patch removes the temporary duplication between bs->file and
bs->file_child by converting everything to BdrvChild.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>

2 files changed, 8 insertions, 3 deletions

diff --git a/include/block/block.h b/include/block/block.h
index 2dd6630..c5d9620 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -585,7 +585,13 @@ typedef enum {
     BLKDBG_EVENT_MAX,
 } BlkDebugEvent;
 
-#define BLKDBG_EVENT(bs, evt) bdrv_debug_event(bs, evt)
+#define BLKDBG_EVENT(child, evt) \
+    do { \
+        if (child) { \
+            bdrv_debug_event(child->bs, evt); \
+        } \
+    } while (0)
+
 void bdrv_debug_event(BlockDriverState *bs, BlkDebugEvent event);
 
 int bdrv_debug_breakpoint(BlockDriverState *bs, const char *event,
diff --git a/include/block/block_int.h b/include/block/block_int.h
index d0dd93e..98936c9 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -380,8 +380,7 @@ struct BlockDriverState {
 
     BlockDriverState *backing_hd;
     BdrvChild *backing_child;
-    BlockDriverState *file;
-    BdrvChild *file_child;
+    BdrvChild *file;
 
     NotifierList close_notifiers;