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The folio_expected_refs() and is_refcount_suitable() consolidation was recently merged: - 86ebd50224c0 ("mm: add folio_expected_ref_count() for reference count calculation") - 0b43b8bc8ef8 ("mm/khugepaged: clean up refcount check using folio_expected_ref_count()") > do_huge_pmd_wp_page() also has an open-coded version of these checks and there > are probably others around the place to. > > These could all be converted to a helper that returns all the "extra" references > after taking into account things like mapping, swapcache, etc. depending on folio.> >> No functional changes intended. >> >> Signed-off-by: Shivank Garg >> --- >> kernel/events/uprobes.c | 5 +++-- >> mm/memfd.c | 4 ++-- >> 2 files changed, 5 insertions(+), 4 deletions(-) >> >> diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c >> index 4c965ba77f9f..c978c8c27340 100644 >> --- a/kernel/events/uprobes.c >> +++ b/kernel/events/uprobes.c >> @@ -434,10 +434,11 @@ static int __uprobe_write_opcode(struct vm_area_struct *vma, >> /* >> * When unregistering, we may only zap a PTE if uffd is disabled and >> * there are no unexpected folio references ... >> + * Expected refs: mappings + swapcache. >> + * We hold one additional reference (+1). >> */ >> if (is_register || userfaultfd_missing(vma) || >> - (folio_ref_count(folio) != folio_mapcount(folio) + 1 + >> - folio_test_swapcache(folio) * folio_nr_pages(folio))) >> + (folio_ref_count(folio) != folio_expected_ref_count(folio) + 1)) >> goto remap; >> >> /* >> diff --git a/mm/memfd.c b/mm/memfd.c >> index ab367e61553d..4ed5506221b7 100644 >> --- a/mm/memfd.c >> +++ b/mm/memfd.c >> @@ -32,8 +32,8 @@ >> >> static bool memfd_folio_has_extra_refs(struct folio *folio) >> { >> - return folio_ref_count(folio) - folio_mapcount(folio) != >> - folio_nr_pages(folio); >> + /* Expected refs: pagecache + mappings */ >> + return folio_ref_count(folio) != folio_expected_ref_count(folio); >> } >> >> static void memfd_tag_pins(struct xa_state *xas) >> -- >> 2.43.0 >> >>