@lina I have seen the same situation in fs realms too, some "not-so-polite" MM guys want to improve their work and pushing new interfaces to fses.
But the main objective of the maintainer for any fs, is to keep their fs working without regression. So migrating to newer interface is not the priority and will only happen gradually.
@lina To me, as long as the discussions are still kept constructive, (not some BS like "yeah, this feature is already implemented in XXX several years ago and it's all your fs' fault not to do it", or "XXXfs is definitely better than YYYYfs") some delay of merging is totally acceptable, and if one really needs to fix others' bugs, that's just bonus patches to me.
It may looks frustrating for now to fix both rust and C, but aren't more contribution better?