Re: [PATCH 1/2] block: make bdrv_drop_intermediate() less wrong

[Alberto Garcia]

On Sat 31 Oct 2020 01:35:01 PM CET, Vladimir Sementsov-Ogievskiy wrote:
> @@ -4958,36 +4958,30 @@ int bdrv_drop_intermediate(BlockDriverState *top, 
> BlockDriverState *base,
>          backing_file_str = base->filename;
>      }
>  
> -    QLIST_FOREACH_SAFE(c, &top->parents, next_parent, next) {
> -        /* Check whether we are allowed to switch c from top to base */
> -        GSList *ignore_children = g_slist_prepend(NULL, c);
> -        ret = bdrv_check_update_perm(base, NULL, c->perm, c->shared_perm,
> -                                     ignore_children, NULL, &local_err);
> -        g_slist_free(ignore_children);
> -        if (ret < 0) {
> -            error_report_err(local_err);
> -            goto exit;
> -        }
> +    bdrv_replace_node(top, base, &local_err);
> +    if (local_err) {
> +        error_report_err(local_err);
> +        goto exit;
> +    }

At the beginning of this function there's a check for c->frozen. I think
you can remove it safely because you also have it in bdrv_replace_node()

Berto