Am 21.02.24 um 07:55 schrieb Markus Armbruster:
>> diff --git a/qapi/block-core.json b/qapi/block-core.json
>> index ab5a93a966..ac05483958 100644
>> --- a/qapi/block-core.json
>> +++ b/qapi/block-core.json
>> @@ -2181,6 +2181,15 @@
>> # destination (all the disk, only the sectors allocated in the
>> # topmost image, or only new I/O).
>> #
>> +# @bitmap: The name of a bitmap to use for sync=bitmap mode. This
>> +# argument must be present for bitmap mode and absent otherwise.
>> +# The bitmap's granularity is used instead of @granularity.
>> +# (Since 9.0).
>
> What happens when the user specifies @granularity anyway? Error or
> silently ignored?
>
It's an error:
>> + if (bitmap) {
>> + if (granularity) {
>> + error_setg(errp, "granularity (%d)"
>> + "cannot be specified when a bitmap is provided",
>> + granularity);
>> + return NULL;
>> + }
>> +#
>> +# @bitmap-mode: Specifies the type of data the bitmap should contain
>> +# after the operation concludes. Must be present if sync is
>> +# "bitmap". Must NOT be present otherwise. (Since 9.0)
>
> Members that must be present when and only when some enum member has a
> certain value should perhaps be in a union branch. Perhaps the block
> maintainers have an opinion here.
>
Sounds sensible to me. Considering also the next patches, in the end it
could be a union discriminated by the @sync which contains @bitmap and
@bitmap-mode when it's the 'bitmap' sync mode, @bitmap when it's the
'incremental' sync mode (@bitmap-sync mode needs to be 'on-success'
then, so there is no choice for the user) and which contains
@granularity for the other sync modes.
Best Regards,
Fiona
