Am 25.06.2020 um 17:22 hat Max Reitz geschrieben: > This includes some permission limiting (for example, we only need to > take the RESIZE permission for active commits where the base is smaller > than the top). > > Use this opportunity to rename qmp_drive_mirror()'s "source" BDS to > "target_backing_bs", because that is what it really refers to. > > Signed-off-by: Max Reitz <mre...@redhat.com>
> @@ -1682,6 +1721,7 @@ static BlockJob *mirror_start_job( > s->zero_target = zero_target; > s->copy_mode = copy_mode; > s->base = base; > + s->base_overlay = bdrv_find_overlay(bs, base); > s->granularity = granularity; > s->buf_size = ROUND_UP(buf_size, granularity); > s->unmap = unmap; Is this valid without freezing the links between base_overlay and base? Actually, I guess we should freeze everything between bs and base (for base != NULL) and it's a preexisting problem that just happens to affect this code, too. Or maybe freezing everything is too much. We only want to make sure that no non-filter is inserted between base and base_overlay and that base (and now base_overlay) always stay in the backing chain of bs. But what options apart from freezing do we have to achieve this? Why is using base_overlay even better than using base? Assuming there is a good reason, maybe the commit message could spell it out. Kevin
