1 files changed, 32 insertions, 22 deletions

diff --git a/fs/proc/page.c b/fs/proc/page.c
index 999af26c7298..ba3568e97fd1 100644
--- a/fs/proc/page.c
+++ b/fs/proc/page.c
@@ -43,6 +43,22 @@ static inline unsigned long get_max_dump_pfn(void)
 #endif
 }
 
+static u64 get_kpage_count(const struct page *page)
+{
+	struct page_snapshot ps;
+	u64 ret;
+
+	snapshot_page(&ps, page);
+
+	if (IS_ENABLED(CONFIG_PAGE_MAPCOUNT))
+		ret = folio_precise_page_mapcount(&ps.folio_snapshot,
+						  &ps.page_snapshot);
+	else
+		ret = folio_average_page_mapcount(&ps.folio_snapshot);
+
+	return ret;
+}
+
 static ssize_t kpage_read(struct file *file, char __user *buf,
 		size_t count, loff_t *ppos,
 		enum kpage_operation op)
@@ -75,10 +91,7 @@ static ssize_t kpage_read(struct file *file, char __user *buf,
 				info = stable_page_flags(page);
 				break;
 			case KPAGE_COUNT:
-				if (IS_ENABLED(CONFIG_PAGE_MAPCOUNT))
-					info = folio_precise_page_mapcount(page_folio(page), page);
-				else
-					info = folio_average_page_mapcount(page_folio(page));
+				info = get_kpage_count(page);
 				break;
 			case KPAGE_CGROUP:
 				info = page_cgroup_ino(page);
@@ -134,6 +147,7 @@ static inline u64 kpf_copy_bit(u64 kflags, int ubit, int kbit)
 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;
@@ -145,20 +159,22 @@ u64 stable_page_flags(const struct page *page)
 	 */
 	if (!page)
 		return 1 << KPF_NOPAGE;
-	folio = page_folio(page);
+
+	snapshot_page(&ps, page);
+	folio = &ps.folio_snapshot;
 
 	k = folio->flags;
 	mapping = (unsigned long)folio->mapping;
-	is_anon = mapping & PAGE_MAPPING_ANON;
+	is_anon = mapping & FOLIO_MAPPING_ANON;
 
 	/*
 	 * pseudo flags for the well known (anonymous) memory mapped pages
 	 */
-	if (page_mapped(page))
+	if (folio_mapped(folio))
 		u |= 1 << KPF_MMAP;
 	if (is_anon) {
 		u |= 1 << KPF_ANON;
-		if (mapping & PAGE_MAPPING_KSM)
+		if (mapping & FOLIO_MAPPING_KSM)
 			u |= 1 << KPF_KSM;
 	}
 
@@ -166,7 +182,7 @@ u64 stable_page_flags(const struct page *page)
 	 * compound pages: export both head/tail info
 	 * they together define a compound page's start/end pos and order
 	 */
-	if (page == &folio->page)
+	if (ps.idx == 0)
 		u |= kpf_copy_bit(k, KPF_COMPOUND_HEAD, PG_head);
 	else
 		u |= 1 << KPF_COMPOUND_TAIL;
@@ -176,25 +192,19 @@ u64 stable_page_flags(const struct page *page)
 	         folio_test_large_rmappable(folio)) {
 		/* Note: we indicate any THPs here, not just PMD-sized ones */
 		u |= 1 << KPF_THP;
-	} else if (is_huge_zero_folio(folio)) {
+	} else if (is_huge_zero_pfn(ps.pfn)) {
 		u |= 1 << KPF_ZERO_PAGE;
 		u |= 1 << KPF_THP;
-	} else if (is_zero_folio(folio)) {
+	} else if (is_zero_pfn(ps.pfn)) {
 		u |= 1 << KPF_ZERO_PAGE;
 	}
 
-	/*
-	 * Caveats on high order pages: PG_buddy and PG_slab will only be set
-	 * on the head page.
-	 */
-	if (PageBuddy(page))
-		u |= 1 << KPF_BUDDY;
-	else if (page_count(page) == 0 && is_free_buddy_page(page))
+	if (ps.flags & PAGE_SNAPSHOT_PG_BUDDY)
 		u |= 1 << KPF_BUDDY;
 
-	if (PageOffline(page))
+	if (folio_test_offline(folio))
 		u |= 1 << KPF_OFFLINE;
-	if (PageTable(page))
+	if (folio_test_pgtable(folio))
 		u |= 1 << KPF_PGTABLE;
 	if (folio_test_slab(folio))
 		u |= 1 << KPF_SLAB;
@@ -202,7 +212,7 @@ u64 stable_page_flags(const struct page *page)
 #if defined(CONFIG_PAGE_IDLE_FLAG) && defined(CONFIG_64BIT)
 	u |= kpf_copy_bit(k, KPF_IDLE,          PG_idle);
 #else
-	if (folio_test_idle(folio))
+	if (ps.flags & PAGE_SNAPSHOT_PG_IDLE)
 		u |= 1 << KPF_IDLE;
 #endif
 
@@ -228,7 +238,7 @@ u64 stable_page_flags(const struct page *page)
 	if (u & (1 << KPF_HUGE))
 		u |= kpf_copy_bit(k, KPF_HWPOISON,	PG_hwpoison);
 	else
-		u |= kpf_copy_bit(page->flags, KPF_HWPOISON,	PG_hwpoison);
+		u |= kpf_copy_bit(ps.page_snapshot.flags, KPF_HWPOISON, PG_hwpoison);
 #endif
 
 	u |= kpf_copy_bit(k, KPF_RESERVED,	PG_reserved);