Re: [PATCH RFC 0/3] mirror: rework soft-cancelling READY mirror

[Vladimir Sementsov-Ogievskiy]

27.07.2021 19:47, Vladimir Sementsov-Ogievskiy wrote:
> Hi all!
>
> That's an alternative to (part of) Max's
> "[PATCH for-6.1? v2 0/7] mirror: Handle errors after READY cancel"
> and shows' my idea of handling soft-cancelling READY mirror case
> directly in qmp_block_job_cancel. And cleanup all other job cancelling
> functions.
>
> That's untested draft, don't take it to heart :)


Side idea:

Instead of this all we can do the following:

1. Add new interface as alternative to soft-cancelling READY mirror.

It may be argument to job-complete qmp command, or some separate command to 
change job parameters, or just an option for blockdev-mirror command (may be 
our users actually know what they want when they start the job).

2. Deprecate block-job-cancel command (with recommendation to use job-cancel 
and new interface [1] instead)

3. Wait for 3 releases and apply patch 3, improved by dropping block-job-cancel 
at all.


This way, deprecated interface remains buggy until dropped, but that's not bad. 
It's good actually :)


> Vladimir Sementsov-Ogievskiy (3):
>    job: add job_complete_ex with do_graph_change argument
>    job: use complete(do_graph_change=false) to handle soft cancel
>    job: drop force argument of *job*cancel
>
>   include/qemu/job.h               | 19 ++++++++----------
>   block/backup.c                   |  2 +-
>   block/mirror.c                   | 33 +++++++++++++++++---------------
>   blockdev.c                       | 13 +++++++++++--
>   job-qmp.c                        |  2 +-
>   job.c                            | 27 ++++++++++++++------------
>   tests/unit/test-bdrv-drain.c     |  2 +-
>   tests/unit/test-block-iothread.c |  2 +-
>   tests/unit/test-blockjob-txn.c   |  8 ++++----
>   tests/unit/test-blockjob.c       |  4 ++--
>   10 files changed, 62 insertions(+), 50 deletions(-)


--
Best regards,
Vladimir