Redmine

We use subtasks to create code review tasks. Basically, when code is checked in, a subtask can be added to a revision. That subtask is now related to the original bug report. But we are unable to search for all tickets who have a CodeReview subtask (or the reverse to look for all tickets in a certain status which do not have a subtask of type CodeReview). Any help is appreciated.

Furthermore, if anyone has a proven workflow in redmine to do codereviews of checked in code, please share.

Thanks.