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);
-void bdrv_commit_all(void);
+int bdrv_commit_all(void);
int bdrv_change_backing_file(BlockDriverState *bs,
const char *backing_file, const char *backing_fmt);
void bdrv_register(BlockDriver *bdrv);