On 09.07.20 17:13, Andrey Shinkevich wrote:
> On 25.06.2020 18:21, Max Reitz wrote:
>> Because of the (not so recent anymore) changes that make the stream job
>> independent of the base node and instead track the node above it, we
>> have to split that "bottom" node into two cases: The bottom COW node,
>> and the node directly above the base node (which may be an R/W filter
>> or the bottom COW node).
>>
>> Signed-off-by: Max Reitz <mreitz@redhat.com>
>> ---
>>   qapi/block-core.json |  4 +++
>>   block/stream.c       | 63 ++++++++++++++++++++++++++++++++------------
>>   blockdev.c           |  4 ++-
>>   3 files changed, 53 insertions(+), 18 deletions(-)
>>
>> diff --git a/qapi/block-core.json b/qapi/block-core.json
>> index b20332e592..df87855429 100644
>> --- a/qapi/block-core.json
>> +++ b/qapi/block-core.json
>> @@ -2486,6 +2486,10 @@
>>   # On successful completion the image file is updated to drop the
>> backing file
>>   # and the BLOCK_JOB_COMPLETED event is emitted.
>>   #
>> +# In case @device is a filter node, block-stream modifies the first
>> non-filter
>> +# overlay node below it to point to base's backing node (or NULL if
>> @base was
> 
> Forgot one thing. To me, it would be more understandable to read
> 
> "...to point to the base as backing node..." because it may be thought
> as a backing
> 
> node of the base.

This doesn’t sound like it’s about understandability; “point to the base
as backing node” and “point to base’s backing node [as backing node]”
are semantically different.

Was my phrasing just wrong?  @base should be the backing node, so yours
seems correct.

Max