On Thu, Feb 16, 2023 at 03:05:06PM -0800, Russ Allbery wrote: >... > Each time you change the defaults in a way that could be > backward-incompatible, you could capture those new defaults in a > permanently-fixed label of, say, 20230616, which is the defaults on that > date. Probably in the default /etc/mke2fs.conf. I don't expect you to > care about what systems they work with, what distributions they work with, > or anything else other than the timeline of when you decided to change the > defaults, something you're presumably already doing as a maintainer. The > only additional work would be to update these labels with the settings > required to make mke2fs with its current defaults behave compatibly with > whatever the defaults had been at each of those captured points in time. > > (And obviously eventually you could drop the really old ones if it made no > sense to keep supporting them, or have some single really-ancient fallback > for really old systems, etc.) > > Then, image creators can look in /etc/mke2fs.conf for the timestamp that > most closely aligns with the target system they want to create and use > that group of settings. If that turns out to be inadequate, they can go > back to a previous date.
The image creators could just set the features they enable to what they copied from /etc/mke2fs.conf from the target distribution, a label with a timestamp wouldn'tbring much benefit here. We are talking about tools for creating filesystems and their authors, users of these tools don't have to know anything about all that. > Some work on their part is still required, but > from their perspective I think this would have the advantage of not having > to do research to reconstruct what all the options could be and how they > changed and which ones were potentially backward-incompatible, which are > all things you would generally already know and have in mind when you > changed the defaults and thus could capture for them. >... Image creators usually support several different filesystems. There is also the point that a tool in bookworm that supports creating bullseye images will also support creating bookworm images, so when there is a difference in the settings for bullseye and bookworm images it should anyway be updated for the difference. Setting a new default for bookworm or disabling a new feature for <= bullseye, the work is trivial in any case and the hard part is all image creators being aware that there is a difference. cu Adrian
