Re: [PATCH v3 3/7] qapi: block-job-change: make copy-mode parameter optional

[Kevin Wolf <kwolf@redhat.com>]

Am 02.10.2024 um 16:06 hat Vladimir Sementsov-Ogievskiy geschrieben:
> We are going to add more parameters to change. We want to make possible
> to change only one or any subset of available options. So all the
> options should be optional.
> 
> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
> Acked-by: Markus Armbruster <armbru@redhat.com>

This is different from blockdev-reopen, which requires repeating all
options (and can therefore reuse the type from blockdev-add). One of the
reasons why we made it like that is that we had some options for which
"option absent" was a meaningful value in itself, so it would have
become ambiguous if an absent option in blockdev-reopen should mean
"leave the existing value unchanged" or "unset the option".

Are we confident that this will never happen with job options? In case
of doubt, I would go for consistency with blockdev-reopen.

Either way, it would be good to document the reasoning for whatever
option we choose in the commit message.

Kevin