Re: [PATCH RFC v2 5/5] block: Deprecate transaction type drive-backup

[Kevin Wolf <kwolf@redhat.com>]

Am 11.10.2021 um 20:58 hat Eric Blake geschrieben:
> On Sat, Oct 09, 2021 at 02:09:44PM +0200, Markus Armbruster wrote:
> > Several moons ago, Vladimir posted
> > 
> >     Subject: [PATCH v2 3/3] qapi: deprecate drive-backup
> >     Date: Wed,  5 May 2021 16:58:03 +0300
> >     Message-Id: <20210505135803.67896-4-vsementsov@virtuozzo.com>
> >     https://lists.gnu.org/archive/html/qemu-devel/2021-05/msg01394.html
> > 
> > with this
> > 
> >     TODO: We also need to deprecate drive-backup transaction action..
> >     But union members in QAPI doesn't support 'deprecated' feature. I tried
> >     to dig a bit, but failed :/ Markus, could you please help with it? At
> >     least by advice?
> > 
> > This is one way to resolve it.  Sorry it took so long.
> > 
> > John explored another way, namely adding feature flags to union
> > branches.  Could also be useful, say to add different features to
> > branches in multiple unions sharing the same tag enum.
> > 
> > Signed-off-by: Markus Armbruster <armbru@redhat.com>
> > ---
> >  qapi/transaction.json | 5 ++++-
> >  1 file changed, 4 insertions(+), 1 deletion(-)
> > 
> > diff --git a/qapi/transaction.json b/qapi/transaction.json
> > index d175b5f863..0564a893b3 100644
> > --- a/qapi/transaction.json
> > +++ b/qapi/transaction.json
> > @@ -54,6 +54,9 @@
> >  # @blockdev-snapshot-sync: since 1.1
> >  # @drive-backup: Since 1.6
> >  #
> > +# Features:
> > +# @deprecated: Member @drive-backup is deprecated.  Use FIXME instead.
> 
> Obviously, we'd need to flesh this out ("'blockdev-backup' with proper
> node names"? something else?) before dropping RFC on this patch.

What does 'blockdev-backup' with improper node names look like?

I think it's sufficient to say "Use @blockdev-backup instead", which is
already documented to take a node/device name instead of a file name.

> And we'd want to edit docs/about/deprecated.rst to match.

Yes.

Kevin