Re: [Qemu-devel] [PATCH V2 1/3] colo-compare: introduce colo compare initlization

[Zhang Chen <zhangchen.fnst@cn.fujitsu.com>]

>> +    if (!size) {
>> +        return 0;
>> +    }
>> +
>> +    ret = qemu_chr_fe_write_all(out, (uint8_t *)&len, sizeof(len));
>> +    if (ret != sizeof(len)) {
>> +        goto err;
>> +    }
>> +
>> +    ret = qemu_chr_fe_write_all(out, (uint8_t *)buf, size);
>> +    if (ret != size) {
>> +        goto err;
>> +    }
>> +
> You can make this slightly simpler and save the return 0;

If we want to save the return 0 , the code will be changed like that:

err:
     return (ret < 0 || ret == size) ? ret : -EIO;

I think it too complex to be understood, so should we keep the original ?

>> +    return 0;
>> +
>> +err:
>> +    return ret < 0 ? ret : -EIO;
> err:
>         return ret <= 0 ? ret : -EIO;

This is wrong, if qemu_chr_fe_write_all success, ret will equal size.
return -EIO.

>> +}
>> +
>> +static int compare_chr_can_read(void *opaque)
>> +{
>> +    return COMPARE_READ_LEN_MAX;
>> +}
>>

-- 
Thanks
zhangchen