mm/rmap: move folio_test_anon() check out of __folio_set_anon()

Let's handle it in the caller; no need for the "first" check based on the
mapcount.

We really only end up with !anon pages in page_add_anon_rmap() via
do_swap_page(), where we hold the folio lock.  So races are not possible. 
Add a VM_WARN_ON_FOLIO() to make sure that we really hold the folio lock.

In the future, we might want to let do_swap_page() use
folio_add_new_anon_rmap() on new pages instead: however, we might have to
pass then whether the folio is exclusive or not.  So keep it in there for
now.

For hugetlb we never expect to have a non-anon page in
hugepage_add_anon_rmap().  Remove that code, along with some other checks
that are either not required or were checked in
hugepage_add_new_anon_rmap() already.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: David Hildenbrand <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Mike Kravetz <[email protected]>
Cc: Muchun Song <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

0 files changed, 0 insertions, 0 deletions