Re: [PATCH v2 09/31] qapi/qom: Add ObjectOptions for throttle-group

[Kevin Wolf]

Am 26.02.2021 um 18:26 hat Eric Blake geschrieben:
> On 2/24/21 7:52 AM, Kevin Wolf wrote:
> > This adds a QAPI schema for the properties of the throttle-group object.
> > 
> > The only purpose of the x-* properties is to make the nested options in
> > 'limits' available for a command line parser that doesn't support
> > structs. Any parser that will use the QAPI schema will supports structs,
> > though, so they will not be needed in the schema in the future.
> > 
> > To keep the conversion straightforward, add them to the schema anyway.
> > We can then remove the options and adjust documentation, test cases etc.
> > in a separate patch.
> > 
> > Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> > ---
> >  qapi/block-core.json | 27 +++++++++++++++++++++++++++
> >  qapi/qom.json        |  7 +++++--
> >  2 files changed, 32 insertions(+), 2 deletions(-)
> > 
> > diff --git a/qapi/block-core.json b/qapi/block-core.json
> > index 9f555d5c1d..a67fa0cc59 100644
> > --- a/qapi/block-core.json
> > +++ b/qapi/block-core.json
> > @@ -2504,6 +2504,33 @@
> >              '*bps-write-max' : 'int', '*bps-write-max-length' : 'int',
> >              '*iops-size' : 'int' } }
> >  
> > +##
> > +# @ThrottleGroupProperties:
> > +#
> > +# Properties for throttle-group objects.
> 
> Corresponds to block/throttle-groups.c:throttle_group_obj_class_init()
> with its ThrottleParamInfo struct for the x- fields, and limits as-is.
> 
> > +#
> > +# The options starting with x- are aliases for the same key without x- in
> > +# the @limits object. As indicated by the x- prefix, this is not a stable
> > +# interface and may be removed or changed incompatibly in the future. Use
> > +# @limits for a supported stable interface.
> > +#
> > +# @limits: limits to apply for this throttle group
> 
> And I did check that qapi/block-core.json:ThrottleLimits has the same
> fields as the ThrottleParamInfo x- fields.  All this duplication!  But
> we're getting to a state where it will be easier to clean up the cruft.

Indeed, after this series you can use 'limit' everywhere, so there is no
real reason for the x- fields to stay. I almost included the removal in
this series, but then it turned out that some more test cases depend on
it than I wanted to fix up on the side. But it's an obvious follow-up
series.

Kevin