Re: [RFC qemu 0/6] mirror: implement incremental and bitmap modes

[John Snow <jsnow@redhat.com>]

On 8/21/20 9:03 AM, Max Reitz wrote:
> On 18.02.20 11:07, Fabian Grünbichler wrote:
> 
> [Sorry :/]
> 
>> picking up on John's in-progress patch series from last summer, this is
>> a stab at rebasing and adding test cases for the low-hanging fruits:
>>
>> - bitmap mirror mode with always/on-success/never bitmap sync mode
>> - incremental mirror mode as sugar for bitmap + on-success
>>
>> Fabian Grünbichler (4):
>>    mirror: add check for bitmap-mode without bitmap
>>    mirror: switch to bdrv_dirty_bitmap_merge_internal
>>    iotests: add test for bitmap mirror
>>    mirror: move some checks to QMP
>>
>> John Snow (2):
>>    drive-mirror: add support for sync=bitmap mode=never
>>    drive-mirror: add support for conditional and always bitmap sync modes
> 
> Looks reasonable to me.  I would indeed merge patches 2 through 4 into a
> single one, and perhaps switch patches 5 and 6.
> 
> Also, we still need an S-o-b from John on patch 2.
> 

Whoops! Will do.

> I have one question: When the mirror job completes successfully (or is
> cancelled “successfully”), the bitmap is always fully cleared when the
> job completes, right?  (Unless in “never” mode.)
> 

I don't remember personally, it's been a minute ...

> Not that I think we should change the current implementation of “clear
> sync_bitmap; merge dirty_bitmap into sync_bitmap;”.  Just a question for
> understanding.
> 
> 
> Soo...  What’s the plan?
> 
> Max
>