1 files changed, 1 insertions, 0 deletions
diff --git a/block.h b/block.h
index c89590df4d..650d872f46 100644
--- a/block.h
+++ b/block.h
@@ -174,6 +174,7 @@ int coroutine_fn bdrv_co_is_allocated_above(BlockDriverState *top,
                                             int nb_sectors, int *pnum);
 BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs,
     const char *backing_file);
+int bdrv_get_backing_file_depth(BlockDriverState *bs);
 int bdrv_truncate(BlockDriverState *bs, int64_t offset);
 int64_t bdrv_getlength(BlockDriverState *bs);
 int64_t bdrv_get_allocated_file_size(BlockDriverState *bs);