OK, here is v2 with changes as recommended by Christoph Hellwig and
Matthew Wilcox (thanks!):

* Changed refs to @refs, and added some more documentation as well.

* Completely removed try_get_page(). (I'm adding more people and lists
to Cc, because of those call site changes.)

* Reversed the logic in try_grab_page() to make it a touch more
  readable.

Also, this has been rebased to today's linux-next (next-20210810), and
re-tested on that.

Here is the v1 cover letter, edited slightly to keep up with the latest
story.

While reviewing some of the other things going on around gup.c, I
noticed that the documentation was wrong for a few of the routines that
I wrote. And then I noticed that there was some significant code
duplication too. So this fixes those issues.

This is not entirely risk-free, but after looking closely at this, I
think it's actually a useful improvement, getting rid of the code
duplication here.

However, it is possible I've overlooked something. I did some local LTP
and other testing on an x86 test machine but failed to find any problems
yet.

And the original v1 is here:
https://lore.kernel.org/r/20210808235018.1924918-1-jhubbard@nvidia.com (local)

John Hubbard (3):
  mm/gup: documentation corrections for gup/pup
  mm/gup: small refactoring: simplify try_grab_page()
  mm/gup: Remove try_get_page(), call try_get_compound_head() directly

 arch/s390/mm/fault.c |  2 +-
 fs/pipe.c            |  2 +-
 include/linux/mm.h   | 10 +-----
 mm/gup.c             | 79 ++++++++++++++++++++++----------------------
 4 files changed, 43 insertions(+), 50 deletions(-)

--
2.32.0