Since we no longer attempt to write back filesystem folios in pageout(),
and only tmpfs/shmem folios and anonymous swapcache folios can be written
back, we can remove the redundant folio_test_private() related logic to
simplify the logic of pageout(), as tmpfs/shmem and swapcache folios do
not use the PG_private flag.

Changes from v1:
 - Re-write the commit message for patch 1 after discussing with Hugh. Thanks.
 - Add a warning to catch this unlikely case.
 - Add acked tags. Thanks.

Baolin Wang (2):
  mm: vmscan: remove folio_test_private() check in pageout()
  mm: vmscan: simplify the folio refcount check in pageout()

 mm/vmscan.c | 28 +++++++---------------------
 1 file changed, 7 insertions(+), 21 deletions(-)

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2.43.7