Re: [Qemu-block] [Qemu-devel] [PATCH for-2.10] quorum: Handle bdrv_getlength() failures in quorum_co_flush()

[Alberto Garcia]

On Mon 07 Aug 2017 01:29:09 PM CEST, Eric Blake wrote:
> On 08/07/2017 03:43 AM, Alberto Garcia wrote:
>> On Fri 04 Aug 2017 05:44:00 PM CEST, Eric Blake wrote:
>>>> --- a/block/quorum.c
>>>> +++ b/block/quorum.c
>>>> @@ -785,8 +785,9 @@ static coroutine_fn int 
>>>> quorum_co_flush(BlockDriverState *bs)
>>>>      for (i = 0; i < s->num_children; i++) {
>>>>          result = bdrv_co_flush(s->children[i]->bs);
>>>>          if (result) {
>>>> +            int64_t length = bdrv_getlength(s->children[i]->bs);
>>>>              quorum_report_bad(QUORUM_OP_TYPE_FLUSH, 0,
>>>> -                              bdrv_getlength(s->children[i]->bs),
>>>> +                              length > 0 ? length : 0,
>>>
>>> In the fallback case, is always picking 0 good enough?  Then again,
>>> this is in the error path, so it is unlikely in practice, and I don't
>>> see any better way to handle it.
>> 
>> I don't see any better way to handle it either, and I'm not sure that it
>> matters much: this is a flush error event, the 'sectors-count' field
>> doesn't even mean anything, but we have to put something there.
>
> If that's the case, can we ALWAYS report 0, instead of usually the
> length and sometimes 0?

That's actually not a bad idea, I'll send the patch now.

Berto