Re: [PATCH v3 2/4] bitmap: Enforce maximum bitmap name length

[Vladimir Sementsov-Ogievskiy]

15.11.2019 19:33, Eric Blake wrote:
> On 11/15/19 9:47 AM, Vladimir Sementsov-Ogievskiy wrote:
>> 15.11.2019 18:03, Vladimir Sementsov-Ogievskiy wrote:
>>> 14.11.2019 5:46, Eric Blake wrote:
>>>> We document that for qcow2 persistent bitmaps, the name cannot exceed
>>>> 1023 bytes.  It is inconsistent if transient bitmaps do not have to
>>>> abide by the same limit, and it is unlikely that any existing client
>>>> even cares about using bitmap names this long.  It's time to codify
>>>> that ALL bitmaps managed by qemu (whether persistent in qcow2 or not)
>>>> have a documented maximum length.
>>>>
>>>> Signed-off-by: Eric Blake <address@hidden>
>>>
>>> Reviewed-by: Vladimir Sementsov-Ogievskiy <address@hidden>
>>>
>>>
>>
>> One doubt:
>>
>> Is it good idea to include string larger than 4K into error message
>> (in next patch too)? I doubt that such message would be
>> readable, and I think that most possible source of such message is
>> some kind of memory corruption, so the whole message would be garbage,
>> which may contain special symbols which may look bad or even break
>> output.
> 
> The string was provided by the user. You are correct that it results in a lot 
> of output on stderr, but it is no more garbage than what the user provided in 
> the first place. If we wanted, we could truncate (list only the first 256 or 
> so bytes and then output "..."), but it's such a corner case error that I 
> don't think it's worth the effort to worry about it.
> 

OK

-- 
Best regards,
Vladimir