Re: [PATCH v2 00/10] qemu: add option to process offloaded legacy blockjob event ealier

On Fri, Nov 13, 2020 at 09:53:28 +0300, Nikolay Shirokovskiy wrote: > This is successor to [1] but I changed the subject as in the review the patch > 'qemu: sync backing chain update in virDomainGetBlockJobInfo' was not > considered good one from design POV. However I think the basic patch is helpful > to address similar issues. Look at [*] for example, there it allows to sync > backing chains during query block stats. > > In discussion of [1] I stated that first patch will also allow to get rid of > stale block job events on reconnection to qemu. But this will require > additional work actually so with this patch series stale events are still > present. And in the discussion it was also mentioned by Peter that stale events > are not harmful for legacy blockjobs code. I also removed previous attempts to > eliminate some of stale events. > > I still keep patch for virDomainGetBlockJobInfo. May be in comparsion to [*] > the approach the patch takes will look not so bad :) > > [1] First version of the patch series > https://www.redhat.com/archives/libvir-list/2020-October/msg01133.html I had a look at this series and it's just doing too much just to "fix" apps which insist on polling especially with pre-blockdev qemu. I simply it's not worth adding the complexity you are proposing. NACK series.

Instead I propose we add a workaround which will report fake unfinished job: https://www.redhat.com/archives/libvir-list/2020-December/msg00352.html The scope of this is way more limited and it doesn't actually try to modify the job code handovers which is very dangerous. I had a look at this series and it's just doing too much just to "fix" apps which insist on polling especially with pre-blockdev qemu. Additionally it adds documentation stating that apps should not poll virDomainGetBlockJobInfo.