On Feb 13, 2019, at 4:59 PM, Matthew Wilcox [off-list ref] wrote:

I believe the direction is clear.  It needs people to do the work.
We're critically short of reviewers.  I got precious little review of
the original XArray work, which made Andrew nervous and delayed its
integration.  Now I'm getting little review of the followup patches
to lay the groundwork for filesystems to support larger page sizes.
I have very little patience for this situation.

I'll be happy to dive in and look at the changes from an mm point of view,
but I don't feel qualified to comment on all the file system
considerations.

Perhaps if someone from the fs side would volunteer; I know well how
frustrating it can be to be trapped in code review suspended animation.