Re: [RFC PATCH 0/2] Allow changing bs->file on reopen

[Kevin Wolf <kwolf@redhat.com>]

Am 05.02.2021 um 13:47 hat Alberto Garcia geschrieben:
> On Thu 21 Jan 2021 11:52:17 AM CET, Kevin Wolf wrote:
> >> Hmm, still, removing a filter which want to unshare WRITE even when
> >> doesn't have any parents will be a problem anyway, so we'll need a
> >> new command to drop filter with a logic like in bdrv_drop_filter in
> >> my series.
> >> 
> >> Or, we can introduce multiple reopen.. So that x-blockdev-reopen will
> >> take a list of BlockdevOptions, and do all modifications in one
> >> transaction. Than we'll be able to drop filter by transactional
> >> update of top node child and removing filter child link.
> >
> > Internally, we already have reopen queues anyway, so it would make
> > sense to me to expose them externally and take a list of
> > BlockdevOptions.  This way we should be able to do even complex
> > changes of the graph where adding some edges requires the removal of
> > other edges in a single atomic operation.
> 
> So you mean changing the signature to something like this?
> 
> { 'command': 'x-blockdev-reopen',
>   'data': { 'options': ['BlockdevOptions'] } }
> 
> It should be easy to make that change, I can have a look.

Yes, this is what I had in mind.

Kevin