folio_test_fs_private() wraps folio->private != NULL check and excludes swapcache and hugetlb folios, since swapcache uses swp_entry_t overlapping with folio->private and hugetlb sets its own flags in folio->private. Replace open code with the helper, since core MM does this check frequently.
No functional change intended. Assisted-by: Claude:claude-opus-4-8 Assisted-by: Codex:gpt-5 Signed-off-by: Zi Yan <[email protected]> To: Andrew Morton <[email protected]> To: David Hildenbrand <[email protected]> To: Steven Rostedt <[email protected]> To: Masami Hiramatsu <[email protected]> To: Lorenzo Stoakes <[email protected]> Cc: "Liam R. Howlett" <[email protected]> Cc: Vlastimil Babka <[email protected]> Cc: Mike Rapoport <[email protected]> Cc: Suren Baghdasaryan <[email protected]> Cc: Michal Hocko <[email protected]> Cc: Mathieu Desnoyers <[email protected]> Cc: Zi Yan <[email protected]> Cc: Baolin Wang <[email protected]> Cc: Nico Pache <[email protected]> Cc: Ryan Roberts <[email protected]> Cc: Dev Jain <[email protected]> Cc: Barry Song <[email protected]> Cc: Lance Yang <[email protected]> Cc: Usama Arif <[email protected]> Cc: Matthew Brost <[email protected]> Cc: Joshua Hahn <[email protected]> Cc: Rakie Kim <[email protected]> Cc: Byungchul Park <[email protected]> Cc: Gregory Price <[email protected]> Cc: Ying Huang <[email protected]> Cc: Alistair Popple <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] --- fs/proc/page.c | 3 +-- include/linux/mm.h | 3 +-- include/linux/page-flags.h | 21 ++++++++++++++++++--- include/trace/events/pagemap.h | 4 +--- mm/huge_memory.c | 4 +--- mm/migrate.c | 3 +-- 6 files changed, 23 insertions(+), 15 deletions(-) diff --git a/fs/proc/page.c b/fs/proc/page.c index abfa6f7d890cc..aab0e20b8f9fa 100644 --- a/fs/proc/page.c +++ b/fs/proc/page.c @@ -234,8 +234,7 @@ u64 stable_page_flags(const struct page *page) u |= kpf_copy_bit(k, KPF_OWNER_2, PG_owner_2); /* preserve the original KPF_PRIVATE semantics by excluding non pagecache folios */ if (folio->mapping && !folio_test_anon(folio) && - (folio_get_private(folio) && !folio_test_swapcache(folio) && - !folio_test_hugetlb(folio))) + folio_test_fs_private(folio)) u |= BIT_ULL(KPF_PRIVATE); u |= kpf_copy_bit(k, KPF_PRIVATE_2, PG_private_2); u |= kpf_copy_bit(k, KPF_OWNER_PRIVATE, PG_owner_priv_1); diff --git a/include/linux/mm.h b/include/linux/mm.h index ebc035ac26ccc..a93eaf7aae545 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -3004,8 +3004,7 @@ static inline int folio_expected_ref_count(const struct folio *folio) /* One reference per page from the pagecache. */ ref_count += !!folio->mapping << order; /* One reference from filesystem private data. */ - ref_count += !!folio->private && !folio_test_hugetlb(folio) && - !folio_test_swapcache(folio); + ref_count += folio_test_fs_private(folio); } /* One reference per page table mapping. */ diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h index 8efc61f967302..0e3628ea080c4 100644 --- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h @@ -1210,6 +1210,23 @@ static __always_inline void __ClearPageAnonExclusive(struct page *page) (0xffUL /* order */ | 1UL << PG_has_hwpoisoned | \ 1UL << PG_large_rmappable | 1UL << PG_partially_mapped) +/** + * folio_test_fs_private - check if the folio has filesystem private data + * @folio: The folio to check. + * + * Use this in code that may encounter swapcache or hugetlb folios but only + * wants to detect filesystem private data. Swapcache stores swp_entry_t in + * folio->swap, a union with folio->private, and hugetlb stores its own flags + * in folio->private; both are excluded. + * + * Return: true if folio->private is set and the folio is neither swapcache + * nor hugetlb. + */ +static inline bool folio_test_fs_private(const struct folio *folio) +{ + return folio_test_private(folio) && !folio_test_swapcache(folio) && + !folio_test_hugetlb(folio); +} /** * folio_has_private - Determine if folio has private stuff * @folio: The folio to be checked @@ -1219,9 +1236,7 @@ static __always_inline void __ClearPageAnonExclusive(struct page *page) */ static inline int folio_has_private(const struct folio *folio) { - return (!!folio->private && !folio_test_swapcache(folio) && - !folio_test_hugetlb(folio)) || - folio_test_private_2(folio); + return folio_test_fs_private(folio) || folio_test_private_2(folio); } #undef PF_ANY diff --git a/include/trace/events/pagemap.h b/include/trace/events/pagemap.h index fb9abec40ec79..5425ef7bbae6e 100644 --- a/include/trace/events/pagemap.h +++ b/include/trace/events/pagemap.h @@ -22,9 +22,7 @@ (folio_test_swapcache(folio) ? PAGEMAP_SWAPCACHE : 0) | \ (folio_test_swapbacked(folio) ? PAGEMAP_SWAPBACKED : 0) | \ (folio_test_mappedtodisk(folio) ? PAGEMAP_MAPPEDDISK : 0) | \ - (folio_test_private(folio) && \ - !folio_test_swapcache(folio) && \ - !folio_test_hugetlb(folio) ? PAGEMAP_BUFFERS : 0) \ + (folio_test_fs_private(folio) ? PAGEMAP_BUFFERS : 0) \ ) TRACE_EVENT(mm_lru_insertion, diff --git a/mm/huge_memory.c b/mm/huge_memory.c index d21a9b8f40d15..7f8e99cdeacb8 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -4799,9 +4799,7 @@ static int split_huge_pages_pid(int pid, unsigned long vaddr_start, * will try to drop it before split and then check if the folio * can be split or not. So skip the check here. */ - if (!(folio_test_private(folio) && - !folio_test_swapcache(folio) && - !folio_test_hugetlb(folio)) && + if (!folio_test_fs_private(folio) && folio_expected_ref_count(folio) != folio_ref_count(folio)) goto next; diff --git a/mm/migrate.c b/mm/migrate.c index ad5daef8721cf..014fcb745d210 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -1330,8 +1330,7 @@ static int migrate_folio_unmap(new_folio_t get_new_folio, * free the metadata, so the page can be freed. */ if (!src->mapping) { - if (folio_test_private(src) && !folio_test_swapcache(src) && - !folio_test_hugetlb(src)) { + if (folio_test_fs_private(src)) { try_to_free_buffers(src); goto out; } -- 2.53.0
