Re: [Qemu-devel] [RFC v4 19/21] blockjobs: Expose manual property

[Kevin Wolf <kwolf@redhat.com>]

Am 27.02.2018 um 22:57 hat John Snow geschrieben:
> 
> 
> On 02/27/2018 03:16 PM, Eric Blake wrote:
> > On 02/23/2018 05:51 PM, John Snow wrote:
> >> Expose the "manual" property via QAPI for the backup-related jobs.
> >> As of this commit, this allows the management API to request the
> >> "concluded" and "dismiss" semantics for backup jobs.
> >>
> >> Signed-off-by: John Snow <jsnow@redhat.com>
> >> ---
> >>   blockdev.c           | 19 ++++++++++++++++---
> >>   qapi/block-core.json | 32 ++++++++++++++++++++++++++------
> >>   2 files changed, 42 insertions(+), 9 deletions(-)
> >>
> > 
> >> +++ b/qapi/block-core.json
> >> @@ -1177,6 +1177,16 @@
> >>   # @job-id: identifier for the newly-created block job. If
> >>   #          omitted, the device name will be used. (Since 2.7)
> >>   #
> >> +# @manual: True to use an expanded, more explicit job control flow.
> >> +#          Jobs may transition from a running state to a pending state,
> >> +#          where they must be instructed to complete manually via
> >> +#          block-job-finalize.
> >> +#          Jobs belonging to a transaction must either all or all not
> >> use this
> >> +#          setting. Once a transaction reaches a pending state,
> >> issuing the
> >> +#          finalize command to any one job in the transaction is
> >> sufficient
> >> +#          to finalize the entire transaction.
> > 
> > The previous commit message talked about mixed-manual transactions, but
> > this seems to imply it is not possible.  I'm fine if we don't support
> > mixed-manual transactions, but wonder if it means any changes to the
> > series.
> > 
> > Otherwise looks reasonable from the UI point of view.
> > 
> 
> More seriously, this documentation I wrote doesn't address the totality
> of the expanded flow. I omitted dismiss here by accident as well. This
> is at best a partial definition of the 'manual' property.
> 
> I'd like to use _this_ patch to ask the question: "What should the
> proper noun for the QEMU 2.12+ Expanded Block Job Management Flow
> Mechanism be?"
> 
> I'm not too sure, but "Manual mode" leaves a lot to be desired.

I still think that the best way to expose it is like this:

    # both default to true
    '*auto-finalize': 'bool',
    '*auto-dismiss': 'bool',

These options would be very easy to describe because they just invoke
the functionality of a specific QMP command automatically as soon as it
becomes available for the job.

But given how often I already said that and people still don't consider
it as an option, this doesn't appear to have been very convincing. So
whatever... *shrug*

Kevin