mm/huge_memory: fix folio_set_dirty() vs. folio_mark_dirty()

The correct folio replacement for "set_page_dirty()" is
"folio_mark_dirty()", not "folio_set_dirty()".  Using the latter won't
properly inform the FS using the dirty_folio() callback.

This has been found by code inspection, but likely this can result in some
real trouble.

Link: https://lkml.kernel.org/r/[email protected]
Fixes: a8e61d5 ("mm/huge_memory: page_remove_rmap() -> folio_remove_rmap_pmd()")
Signed-off-by: David Hildenbrand <[email protected]>
Cc: Ryan Roberts <[email protected]>
Cc: Matthew Wilcox (Oracle) <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

mm/huge_memory.c

@@ -2437,7 +2437,7 @@ static void __split_huge_pmd_locked(struct vm_area_struct *vma, pmd_t *pmd,
  page = pmd_page(old_pmd);
  folio = page_folio(page);
  if (!folio_test_dirty(folio) && pmd_dirty(old_pmd))
- folio_set_dirty(folio);
+ folio_mark_dirty(folio);
  if (!folio_test_referenced(folio) && pmd_young(old_pmd))
  folio_set_referenced(folio);
  folio_remove_rmap_pmd(folio, page, vma);
@@ -3563,7 +3563,7 @@ int set_pmd_migration_entry(struct page_vma_mapped_walk *pvmw,
  }
 
  if (pmd_dirty(pmdval))
- folio_set_dirty(folio);
+ folio_mark_dirty(folio);
  if (pmd_write(pmdval))
  entry = make_writable_migration_entry(page_to_pfn(page));
  else if (anon_exclusive)