Add folio_is_lazyfree() function to identify lazy-free folios to improve
code readability.

Signed-off-by: Vernon Yang <yanglincheng@kylinos.cn>
---
 include/linux/mm_inline.h | 5 +++++
 mm/rmap.c                 | 4 ++--
 mm/vmscan.c               | 5 ++---
 3 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/include/linux/mm_inline.h b/include/linux/mm_inline.h
index fa2d6ba811b5..65a4ae52d915 100644
--- a/include/linux/mm_inline.h
+++ b/include/linux/mm_inline.h
@@ -35,6 +35,11 @@ static inline int page_is_file_lru(struct page *page)
 	return folio_is_file_lru(page_folio(page));
 }
 
+static inline int folio_is_lazyfree(const struct folio *folio)
+{
+	return folio_test_anon(folio) && !folio_test_swapbacked(folio);
+}
+
 static __always_inline void __update_lru_size(struct lruvec *lruvec,
 				enum lru_list lru, enum zone_type zid,
 				long nr_pages)
diff --git a/mm/rmap.c b/mm/rmap.c
index f955f02d570e..7241a3fa8574 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -1838,7 +1838,7 @@ static inline unsigned int folio_unmap_pte_batch(struct folio *folio,
 	max_nr = (end_addr - addr) >> PAGE_SHIFT;
 
 	/* We only support lazyfree batching for now ... */
-	if (!folio_test_anon(folio) || folio_test_swapbacked(folio))
+	if (!folio_is_lazyfree(folio))
 		return 1;
 	if (pte_unused(pte))
 		return 1;
@@ -1934,7 +1934,7 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma,
 		}
 
 		if (!pvmw.pte) {
-			if (folio_test_anon(folio) && !folio_test_swapbacked(folio)) {
+			if (folio_is_lazyfree(folio)) {
 				if (unmap_huge_pmd_locked(vma, pvmw.address, pvmw.pmd, folio))
 					goto walk_done;
 				/*
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 670fe9fae5ba..f357f74b5a35 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -963,8 +963,7 @@ static void folio_check_dirty_writeback(struct folio *folio,
 	 * They could be mistakenly treated as file lru. So further anon
 	 * test is needed.
 	 */
-	if (!folio_is_file_lru(folio) ||
-	    (folio_test_anon(folio) && !folio_test_swapbacked(folio))) {
+	if (!folio_is_file_lru(folio) || folio_is_lazyfree(folio)) {
 		*dirty = false;
 		*writeback = false;
 		return;
@@ -1501,7 +1500,7 @@ static unsigned int shrink_folio_list(struct list_head *folio_list,
 			}
 		}
 
-		if (folio_test_anon(folio) && !folio_test_swapbacked(folio)) {
+		if (folio_is_lazyfree(folio)) {
 			/* follow __remove_mapping for reference */
 			if (!folio_ref_freeze(folio, 1))
 				goto keep_locked;
-- 
2.51.0