Re: [Qemu-block] [PATCH v4 1/3] block: include base when checking image chain for block allocation

[Alberto Garcia]

On Tue 09 Apr 2019 04:43:12 PM CEST, Vladimir Sementsov-Ogievskiy wrote:
>>> -    while (intermediate && intermediate != base) {
>>> +    while (include_base || intermediate != base) {
>>>           int64_t pnum_inter;
>>>           int64_t size_inter;
>>>   
>>> @@ -2360,6 +2364,10 @@ int bdrv_is_allocated_above(BlockDriverState *top,
>>>               n = pnum_inter;
>>>           }
>>>   
>>> +        if (intermediate == base) {
>>> +            break;
>>> +        }
>>> +
>>>           intermediate = backing_bs(intermediate);
>> 
>> I find that the new condition + the break make things a bit less
>> readable. I think it would be simpler with something like this:
>> 
>>     BlockDriverState *stop_at = include_base ? backing_bs(base) : base;
>> 
>>     while (intermediate != stop_at) {
>>        ...
>>     }
>> 
>
> But in this way you return back dependence on base, which we don't
> freeze and which may disappear on some iteration. We should not touch
> backing_bs(base) in any way.

Ok, I see.

Reviewed-by: Alberto Garcia <address@hidden>

(feel free to edit the comment with my suggestion, or leave it as it is
if you prefer)

Berto