Re: [Qemu-devel] [PATCH 4/4] qapi/block-core: Add "new" qcow2 options

[Max Reitz <mreitz@redhat.com>]

On 20.08.2014 21:36, Eric Blake wrote:
> On 08/20/2014 11:59 AM, Max Reitz wrote:
>> qcow2 supports more than four options by now, add the new options
>> (overlap check mode and metadata cache size)
>>
>> Signed-off-by: Max Reitz <mreitz@redhat.com>
>> ---
>>   qapi/block-core.json | 79 +++++++++++++++++++++++++++++++++++++++++++++++++++-
>>   1 file changed, 78 insertions(+), 1 deletion(-)
>>
>> +##
>> +# @Qcow2OverlapCheckFlags
>> +#
>> +# Structure of flags for each metadata structure. Setting a field to 'true'
>> +# makes qemu guard that structure against unintended overwriting. The default
>> +# value is chosen according to the template given.
>> +#
>> +# @template: Specifies a template mode which can be adjusted using the other
>> +#            flags, defaults to 'cached'
>> +#
> Might be worth mentioning the other fields by name, but that's minor.

Well, there were so many and it would've just been "X: Prevent 
unintended writes to X".

>> +{ 'union': 'Qcow2OverlapChecks',
>> +  'discriminator': {},
>> +  'data': { 'flags': 'Qcow2OverlapCheckFlags',
>> +            'mode':  'Qcow2OverlapCheckMode' } }
>> +
> Slick :)  So patch 3/4 added a new commandline option
> overlap-check.template=str which behaves identically to
> overlap-check=str; the short form is the enum branch of this union, the
> long form is the struct form.  The command line parser has to deal with
> both options being given (and errors out if they don't match), while QMP
> does not.
>
> Reviewed-by: Eric Blake <eblake@redhat.com>

Thank you!

Max