I would guess it's because people don't always try to figure out whether bugs they find that appear to be in Linux-specific code can be reproduced in other codebases, rather than explicit lack of interest or PRs going nowhere slowly.

Is there enough interest in ZFS that an organization could be set up to keep a single core ZFS and coordinate its ports into different OSs in a way all ports benefit from updates and the frontier between core and OS can be clearer?

They're already having regular meetings among participants from each of the respective child projects to try and coordinate things like this and ensure that problems are not arising from people not doing the followup on pushing code upstream/pulling code from upstream to ensure platforms aren't missing major features/bugfixes for years.

[1] is the monthly meeting notes, and while I haven't had a need to visit one and confirm, they certainly appear to be open to interested parties, not just an invite-only group.

(I recently proposed something controversial [2] in an attempt to try and get predictable consistent behavior on a certain thing across all platforms, which is when I learned about this from someone telling me they discussed it there.)

ZoL also maintains their own list of upstream (e.g. openzfs) commits and what their status is of landing in ZoL. [3]

[1] - https://docs.google.com/document/d/1w2jv2XVYFmBVvG1EGf-9A5HB...

[2] - https://openzfs.topicbox.com/groups/developer/T04955dd2e8aa4...

[3] - http://build.zfsonlinux.org/openzfs-tracking.html

Well, this mailing list discussion is serving that function; how much more of an "organization" would you want?

I suppose you could argue for having a single, explicitly OS-independent "upstream repository" rather than treating either Illumos or ZoL as upstream? I doubt there are enough developers who would want to work on ZFS generically rather than ZFS in the context of a particular OS. ZoL maintains a clear separation from Linux proper for licensing reasons so I'd think they're "independent enough" to serve as upstream for non-Linux versions.

> ZoL maintains a clear separation from Linux proper for licensing reasons so I'd think they're "independent enough" to serve as upstream for non-Linux versions.

That would neatly solve the issue of ZoL patches never making it back to Illumos.