[PATCH 07/15] mm: replace direct FOLIO_MAPPING_ANON usage with helpers

[tao]

Replace direct uses of FOLIO_MAPPING_ANON in external modules with
helper functions in preparation for ANON_VMA_LAZY.

Signed-off-by: tao <tao.wangtao@xxxxxxxxx>
---
 fs/proc/page.c             |  6 ++----
 include/linux/page-flags.h | 15 ++++++++++++---
 include/linux/pagemap.h    |  2 +-
 mm/gup.c                   |  6 ++----
 4 files changed, 17 insertions(+), 12 deletions(-)

diff --git a/fs/proc/page.c b/fs/proc/page.c
index f9b2c2c906cd..93ddfda9fa1d 100644
--- a/fs/proc/page.c
+++ b/fs/proc/page.c
@@ -148,7 +148,6 @@ u64 stable_page_flags(const struct page *page)
 	const struct folio *folio;
 	struct page_snapshot ps;
 	unsigned long k;
-	unsigned long mapping;
 	bool is_anon;
 	u64 u = 0;
 
@@ -163,8 +162,7 @@ u64 stable_page_flags(const struct page *page)
 	folio = &ps.folio_snapshot;
 
 	k = folio->flags.f;
-	mapping = (unsigned long)folio->mapping;
-	is_anon = mapping & FOLIO_MAPPING_ANON;
+	is_anon = folio_test_anon(folio);
 
 	/*
 	 * pseudo flags for the well known (anonymous) memory mapped pages
@@ -173,7 +171,7 @@ u64 stable_page_flags(const struct page *page)
 		u |= 1 << KPF_MMAP;
 	if (is_anon) {
 		u |= 1 << KPF_ANON;
-		if (mapping & FOLIO_MAPPING_KSM)
+		if (!PageAnonNotKsm(page))
 			u |= 1 << KPF_KSM;
 	}
 
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index c0cc43118877..50c80a1e2c7c 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -720,15 +720,20 @@ PAGEFLAG_FALSE(VmemmapSelfHosted, vmemmap_self_hosted)
 #define FOLIO_MAPPING_ANON_VMA_LAZY	FOLIO_MAPPING_ANON_KSM
 #define FOLIO_MAPPING_FLAGS	(FOLIO_MAPPING_ANON | FOLIO_MAPPING_ANON_KSM)
 
-static __always_inline bool folio_test_anon(const struct folio *folio)
+static __always_inline bool mapping_is_anon(unsigned long mapping)
 {
 #ifdef CONFIG_ANON_VMA_LAZY
-	return ((unsigned long)folio->mapping & FOLIO_MAPPING_FLAGS) != 0;
+	return (mapping & FOLIO_MAPPING_FLAGS) != 0;
 #else
-	return ((unsigned long)folio->mapping & FOLIO_MAPPING_ANON) != 0;
+	return (mapping & FOLIO_MAPPING_ANON) != 0;
 #endif
 }
 
+static __always_inline bool folio_test_anon(const struct folio *folio)
+{
+	return mapping_is_anon((unsigned long)folio->mapping);
+}
+
 static __always_inline bool folio_test_lazyfree(const struct folio *folio)
 {
 	return folio_test_anon(folio) && !folio_test_swapbacked(folio);
@@ -738,7 +743,11 @@ static __always_inline bool PageAnonNotKsm(const struct page *page)
 {
 	unsigned long flags = (unsigned long)page_folio(page)->mapping;
 
+#ifdef CONFIG_ANON_VMA_LAZY
+	return (flags & FOLIO_MAPPING_FLAGS) != FOLIO_MAPPING_KSM;
+#else
 	return (flags & FOLIO_MAPPING_FLAGS) == FOLIO_MAPPING_ANON;
+#endif
 }
 
 static __always_inline bool PageAnon(const struct page *page)
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index 31a848485ad9..746939872ac4 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -507,7 +507,7 @@ static inline pgoff_t mapping_align_index(const struct address_space *mapping,
 static inline bool mapping_large_folio_support(const struct address_space *mapping)
 {
 	/* AS_FOLIO_ORDER is only reasonable for pagecache folios */
-	VM_WARN_ONCE((unsigned long)mapping & FOLIO_MAPPING_ANON,
+	VM_WARN_ONCE(mapping_is_anon((unsigned long)mapping),
 			"Anonymous mapping always supports large folio");
 
 	return mapping_max_folio_order(mapping) > 0;
diff --git a/mm/gup.c b/mm/gup.c
index ad9ded39609c..69dda325b082 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -2740,7 +2740,6 @@ static bool gup_fast_folio_allowed(struct folio *folio, unsigned int flags)
 	bool reject_file_backed = false;
 	struct address_space *mapping;
 	bool check_secretmem = false;
-	unsigned long mapping_flags;
 
 	/*
 	 * If we aren't pinning then no problematic write can occur. A long term
@@ -2792,9 +2791,8 @@ static bool gup_fast_folio_allowed(struct folio *folio, unsigned int flags)
 		return false;
 
 	/* Anonymous folios pose no problem. */
-	mapping_flags = (unsigned long)mapping & FOLIO_MAPPING_FLAGS;
-	if (mapping_flags)
-		return mapping_flags & FOLIO_MAPPING_ANON;
+	if (mapping_is_anon((unsigned long)mapping))
+		return true;
 
 	/*
 	 * At this point, we know the mapping is non-null and points to an
-- 
2.17.1