static void bdrv_replace_child(BdrvChild *child, BlockDriverState *new_bs, bool check_new_perm) { BlockDriverState *old_bs = child->bs; uint64_t perm, shared_perm; if (old_bs) { /* Update permissions for old node. This is guaranteed to succeed * because we're just taking a parent away, so we're loosening * restrictions. */ bdrv_get_cumulative_perm(old_bs, &perm, &shared_perm); bdrv_check_perm(old_bs, perm, shared_perm, NULL, &error_abort); bdrv_set_perm(old_bs, perm, shared_perm); } bdrv_replace_child_noperm(child, new_bs); if (new_bs) { bdrv_get_cumulative_perm(new_bs, &perm, &shared_perm); if (check_new_perm) { bdrv_check_perm(new_bs, perm, shared_perm, NULL, &error_abort); } bdrv_set_perm(new_bs, perm, shared_perm); } }