[PATCH 3/4] block: Add blk_make_empty()

[Max Reitz]

Two callers of BlockDriver.bdrv_make_empty() remain that should not call
this method directly.  Both do not have access to a BdrvChild, but they
can use a BlockBackend, so we add this function that lets them use it.

Signed-off-by: Max Reitz <address@hidden>
---
 include/sysemu/block-backend.h | 2 ++
 block/block-backend.c          | 5 +++++
 2 files changed, 7 insertions(+)

diff --git a/include/sysemu/block-backend.h b/include/sysemu/block-backend.h
index d37c1244dd..14338b76dc 100644
--- a/include/sysemu/block-backend.h
+++ b/include/sysemu/block-backend.h
@@ -266,4 +266,6 @@ int coroutine_fn blk_co_copy_range(BlockBackend *blk_in, 
int64_t off_in,
 
 const BdrvChild *blk_root(BlockBackend *blk);
 
+int blk_make_empty(BlockBackend *blk, Error **errp);
+
 #endif
diff --git a/block/block-backend.c b/block/block-backend.c
index 3592066b42..5d36efd32f 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -2402,3 +2402,8 @@ const BdrvChild *blk_root(BlockBackend *blk)
 {
     return blk->root;
 }
+
+int blk_make_empty(BlockBackend *blk, Error **errp)
+{
+    return bdrv_make_empty(blk->root, errp);
+}
-- 
2.25.4