[PATCH 0/2 v2] remove PF_MEMALLOC_NORECLAIM

[Michal Hocko <mhocko@kernel.org>]

The previous version has been posted in [1]. Based on the review feedback
I have sent v2 of patches in the same threat but it seems that the
review has mostly settled on these patches. There is still an open
discussion on whether having a NORECLAIM allocator semantic (compare to
atomic) is worthwhile or how to deal with broken GFP_NOFAIL users but
those are not really relevant to this particular patchset as it 1)
doesn't aim to implement either of the two and 2) it aims at spreading
PF_MEMALLOC_NORECLAIM use while it doesn't have a properly defined
semantic now that it is not widely used and much harder to fix.

I have collected Reviewed-bys and reposting here. These patches are
touching bcachefs, VFS and core MM so I am not sure which tree to merge
this through but I guess going through Andrew makes the most sense.

Changes since v1;
- compile fixes
- rather than dropping PF_MEMALLOC_NORECLAIM alone reverted eab0af905bfc
  ("mm: introduce PF_MEMALLOC_NORECLAIM, PF_MEMALLOC_NOWARN") suggested
  by Matthew.