Summer of Code Results: Improve and Extend resize_ffs

Overview

I mentored Christopher Berardi for one of NetBSD's projects in this year's Google Summer of Code. His project was titled "Improve and Extend resize_ffs".

Goals

The original project abstract said:

This project will seek to thoroughly test and improve the resize_ffs utility as well as to potentially extend it to support features such as live resizing. The primary goal is to make resize_ffs stable through a thorough regression test suite and code review, fixing bugs where encountered and improving on areas such as resource utilization.

Christopher successfully identified a number of issues in resize_ffs that will need to be resolved in order to make it ready for import into the base system.

Some of the issues are consistently reproducible, while others are still intermittent at this point. I've begun putting together a set of regression tests based on Christopher's findings, and some further investigation of my own. Some testing techniques were identified during the Summer of Code period that will be used in the regression tests, and a further set of requirements were identified that go beyond the initial use cases that were targetted. In particular, filesystem images in files are more common these days and used within the NetBSD build system, and we'll want resize_ffs to support these as well the block devices it originally was written for.

So, this project has not yet resulted in code in-tree, but hopefully has revitalized the resize_ffs efforts, and I'll be working on further issues myself as well.