Re: [PATCH v6 2/5] block/io: bdrv_common_block_status_above: support include_base

[Alberto Garcia]

On Wed 16 Sep 2020 02:20:05 PM CEST, Vladimir Sementsov-Ogievskiy wrote:
> -    for (p = backing_bs(bs); p != base; p = backing_bs(p)) {
> +    for (p = backing_bs(bs); include_base || p != base; p = backing_bs(p)) {
>          ret = bdrv_co_block_status(p, want_zero, offset, bytes, pnum, map,
>                                     file);
>          if (ret < 0) {
> @@ -2420,6 +2422,11 @@ bdrv_co_common_block_status_above(BlockDriverState *bs,
>              break;
>          }
>  
> +        if (p == base) {
> +            assert(include_base);
> +            break;
> +        }
> +

Another option is something like:

   BlockDriverState *last_bs = include_base ? base : backing_bs(base);

and you get a simpler 'for' loop.

But why do we need include_base at all? Can't the caller just pass
backing_bs(base) instead? I'm talking also about the existing case of
bdrv_is_allocated_above().

Berto