Re: [Qemu-devel] [PATCH v3 02/22] qcow2: Add refcount_width to format-specific info

[Max Reitz <mreitz@redhat.com>]

On 2014-11-27 at 14:47, Stefan Hajnoczi wrote:
> On Thu, Nov 20, 2014 at 06:06:18PM +0100, Max Reitz wrote:
>> Add the bit width of every refcount entry to the format-specific
>> information.
>>
>> In contrast to lazy_refcounts and the corrupt flag, this should be
>> always emitted, even for compat=0.10 although it does not support any
>> refcount width other than 16 bits. This is because if a boolean is
>> optional, one normally assumes it to be false when omitted; but if an
>> integer is not specified, it is rather difficult to guess its value.
>>
>> This new field breaks some test outputs, fix them.
>>
>> Signed-off-by: Max Reitz <mreitz@redhat.com>
>> Reviewed-by: Eric Blake <eblake@redhat.com>
>> ---
>>   block/qcow2.c              |  4 +++-
>>   qapi/block-core.json       |  5 ++++-
>>   tests/qemu-iotests/060.out |  1 +
>>   tests/qemu-iotests/065     | 23 +++++++++++++++--------
>>   tests/qemu-iotests/067.out |  5 +++++
>>   tests/qemu-iotests/082.out |  7 +++++++
>>   tests/qemu-iotests/089.out |  2 ++
>>   7 files changed, 37 insertions(+), 10 deletions(-)
>>
>> diff --git a/block/qcow2.c b/block/qcow2.c
>> index f57aff9..d70e927 100644
>> --- a/block/qcow2.c
>> +++ b/block/qcow2.c
>> @@ -2475,7 +2475,8 @@ static ImageInfoSpecific *qcow2_get_specific_info(BlockDriverState *bs)
>>       };
>>       if (s->qcow_version == 2) {
>>           *spec_info->qcow2 = (ImageInfoSpecificQCow2){
>> -            .compat = g_strdup("0.10"),
>> +            .compat             = g_strdup("0.10"),
>> +            .refcount_width     = s->refcount_bits,
> Why call it "width" in ImageInfoSpecificQCow2 when the qcow2 code calls
> it "bits"?  IMO "bits" is clearer because it tells you the units, and
> it's more consistent.

Well, I'm fine with either. The spec calls it refcount_bits, too, but 
also says it's the "width". My main argument against "bits" would be 
that I'd have to look through the whole series and make sure I change it 
everywhere, and also drop Eric's R-b. *g*

So, yes, I'm fine with changing it to refcount_bits.

Max