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From: Alberto Garcia <berto@igalia.com>
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Date: Mon, 07 Aug 2017 10:43:31 +0200
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Subject: Re: [Qemu-devel] [PATCH for-2.10] quorum: Handle bdrv_getlength()
 failures in quorum_co_flush()
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To: Eric Blake <eblake@redhat.com>, qemu-devel@nongnu.org
Cc: Markus Armbruster <armbru@redhat.com>, qemu-block@nongnu.org

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.

Berto