On Wed, 05 Mar 2025, Yunsheng Lin wrote:

For the existing btrfs and sunrpc case, I am agreed that there
might be valid use cases too, we just need to discuss how to
meet the requirements of different use cases using simpler, more
unified and effective APIs.

We don't need "more unified".

If there are genuinely two different use cases with clearly different
needs - even if only slightly different - then it is acceptable to have
two different interfaces.  Be sure to choose names which emphasise the
differences.

Thanks,
NeilBrown