Re: [PATCH v5 01/14] block: return status from bdrv_append and friends

[Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>]

12.01.2021 20:27, Alberto Garcia wrote:
> On Sat 09 Jan 2021 01:57:58 PM CET, Vladimir Sementsov-Ogievskiy wrote:
>> -void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd,
>> +int bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd,
>>                            Error **errp)
> 
> The indentation of the second line should be adjusted, shouldn't it?
> 
>>   {
>> +    int ret;
>>       bool update_inherits_from = bdrv_chain_contains(bs, backing_hd) &&
>>           bdrv_inherits_from_recursive(backing_hd, bs);
>>   
>>       if (bdrv_is_backing_chain_frozen(bs, child_bs(bs->backing), errp)) {
>> -        return;
>> +        return -EPERM;
>>       }
>>   
>>       if (backing_hd) {
>> @@ -2853,15 +2854,24 @@ void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd,
>>
>>       bs->backing = bdrv_attach_child(bs, backing_hd, "backing", &child_of_bds,
>>                                       bdrv_backing_role(bs), errp);
>> +    if (!bs->backing) {
>> +        ret = -EPERM;
>> +        goto out;
>> +    }
> 
> This is not visible in the patch, but before the bdrv_attach_child()
> call there's this:
> 
>      if (!backing_hd) {
>          goto out;
>      }
> 
> But in this case 'ret' is still uninitialized.
> 
>>   out:
>>       bdrv_refresh_limits(bs, NULL);
>> +
>> +    return ret;
>>   }
> 
> 
> 
>> -static void bdrv_replace_node_common(BlockDriverState *from,
>> -                                     BlockDriverState *to,
>> -                                     bool auto_skip, Error **errp)
>> +static int bdrv_replace_node_common(BlockDriverState *from,
>> +                                    BlockDriverState *to,
>> +                                    bool auto_skip, Error **errp)
>>   {
>>       BdrvChild *c, *next;
>>       GSList *list = NULL, *p;
>> @@ -4562,6 +4572,7 @@ static void bdrv_replace_node_common(BlockDriverState *from,
>>               goto out;
>>           }
>>           if (c->frozen) {
>> +            ret = -EPERM;
>>               error_setg(errp, "Cannot change '%s' link to '%s'",
>>                          c->name, from->node_name);
>>               goto out;
> 
> Same here, you set 'ret' in the second 'goto out' but not in the first.
> 
Oops, you are right, thanks!

-- 
Best regards,
Vladimir