Re: [RFC 0/4] mirror: implement incremental and bitmap modes

[Fiona Ebner <f.ebner@proxmox.com>]

Am 29.02.24 um 13:00 schrieb Vladimir Sementsov-Ogievskiy:
> 
> But anyway, this all could be simply achieved with
> bitmap-copying/merging API, if we allow to pass user-given bitmap to the
> mirror as working bitmap.
> 
>>
>> I see, I'll drop the 'bitmap-mode' in the next version if nobody
>> complains :)
>>
> 
> Good. It's a golden rule: never make public interfaces which you don't
> actually need for production. I myself sometimes violate it and spend
> extra time on developing features, which we later have to just drop as
> "not needed downstream, no sense in upstreaming".
> 

Just wondering which new mode I should allow for the @MirrorSyncMode
then? The documentation states:

> # @incremental: only copy data described by the dirty bitmap.
> #     (since: 2.4)
> #
> # @bitmap: only copy data described by the dirty bitmap.  (since: 4.2)
> #     Behavior on completion is determined by the BitmapSyncMode.

For backup, do_backup_common() just maps @incremental to @bitmap +
@bitmap-mode == @on-success.

Using @bitmap for mirror would lead to being at odds with the
documentation, because it mentions the BitmapSyncMode, which mirror
won't have.

Using @incremental for mirror would be consistent with the
documentation, but behave a bit differently from backup.

Opinions?

Best Regards,
Fiona