block: Add bdrv_change_backing_file
Introduce the functions needed to change the backing file of an image. The
function is implemented for qcow2.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
diff --git a/block.h b/block.h
index f660d5f..bee9ec5 100644
--- a/block.h
+++ b/block.h
@@ -83,6 +83,8 @@
void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr);
void bdrv_guess_geometry(BlockDriverState *bs, int *pcyls, int *pheads, int *psecs);
int bdrv_commit(BlockDriverState *bs);
+int bdrv_change_backing_file(BlockDriverState *bs,
+ const char *backing_file, const char *backing_fmt);
void bdrv_register(BlockDriver *bdrv);
/* async block I/O */
