Re: [Qemu-block] [PATCH 2/5] block/qcow2-bitmap: Allow bitmap flushing

[John Snow]

On 3/6/19 7:58 AM, Eric Blake wrote:
> On 3/5/19 5:43 PM, John Snow wrote:
>> Usually, we only write out bitmaps when we're about to close out the file,
>> so we always remove the bitmaps after to make it easier to determine the
>> source of truth for migration purposes.
>>
>> However, there may be times we want to flush bitmap data more aggressively,
>> like after a truncate event where we need to make the metadata consistent
>> again.
> 
> Or, as I've mentioned in other threads, after every
> bitmap-add/bitmap-delete operation, so that 'qemu-img info -U' can see
> which persistent bitmaps exist. But that's one step further than this
> series, so I won't insist on it today.
> 

Yes, I was keeping that in mind as I wrote this. I think it extends to
those cases trivially, so long as Vladimir is OK with what I'm trying to do.