iotests: 30: prepare to COR filter insertion by stream job
test_stream_parallel run parallel stream jobs, intersecting so that top
of one is base of another. It's OK now, but it would be a problem if
insert the filter, as one job will want to use another job's filter as
above_base node.
Correct thing to do is move to new interface: "bottom" argument instead
of base. This guarantees that jobs don't intersect by their actions.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <
20201216061703.70908-12-vsementsov@virtuozzo.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>