[PATCH v3] mm/migrate: rename PAGE_ migration flags to FOLIO_

[Shivank Garg]

These flags only track folio-specific state during migration and are
not used for movable_ops pages. Rename the enum values and the
old_page_state variable to match.

No functional change.

Suggested-by: David Hildenbrand <david@xxxxxxxxxx>
Acked-by: David Hildenbrand (Arm) <david@xxxxxxxxxx>
Reviewed-by: Zi Yan <ziy@xxxxxxxxxx>
Signed-off-by: Shivank Garg <shivankg@xxxxxxx>
---
Applies cleanly on mm-new (02b045682c74).

v2: https://lore.kernel.org/all/20260324114720.864478-2-shivankg@xxxxxxx

v3:
- Change to two-tab indent (David)

 mm/migrate.c | 48 +++++++++++++++++++++++-------------------------
 1 file changed, 23 insertions(+), 25 deletions(-)

diff --git a/mm/migrate.c b/mm/migrate.c
index 05cb408846f2..6d4a85f903d8 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1135,26 +1135,24 @@ static int move_to_new_folio(struct folio *dst, struct folio *src,
  * This is safe because nobody is using it except us.
  */
 enum {
-	PAGE_WAS_MAPPED = BIT(0),
-	PAGE_WAS_MLOCKED = BIT(1),
-	PAGE_OLD_STATES = PAGE_WAS_MAPPED | PAGE_WAS_MLOCKED,
+	FOLIO_WAS_MAPPED = BIT(0),
+	FOLIO_WAS_MLOCKED = BIT(1),
+	FOLIO_OLD_STATES = FOLIO_WAS_MAPPED | FOLIO_WAS_MLOCKED,
 };
 
 static void __migrate_folio_record(struct folio *dst,
-				   int old_page_state,
-				   struct anon_vma *anon_vma)
+		int old_folio_state, struct anon_vma *anon_vma)
 {
-	dst->private = (void *)anon_vma + old_page_state;
+	dst->private = (void *)anon_vma + old_folio_state;
 }
 
 static void __migrate_folio_extract(struct folio *dst,
-				   int *old_page_state,
-				   struct anon_vma **anon_vmap)
+		int *old_folio_state, struct anon_vma **anon_vmap)
 {
 	unsigned long private = (unsigned long)dst->private;
 
-	*anon_vmap = (struct anon_vma *)(private & ~PAGE_OLD_STATES);
-	*old_page_state = private & PAGE_OLD_STATES;
+	*anon_vmap = (struct anon_vma *)(private & ~FOLIO_OLD_STATES);
+	*old_folio_state = private & FOLIO_OLD_STATES;
 	dst->private = NULL;
 }
 
@@ -1209,7 +1207,7 @@ static int migrate_folio_unmap(new_folio_t get_new_folio,
 {
 	struct folio *dst;
 	int rc = -EAGAIN;
-	int old_page_state = 0;
+	int old_folio_state = 0;
 	struct anon_vma *anon_vma = NULL;
 	bool locked = false;
 	bool dst_locked = false;
@@ -1253,7 +1251,7 @@ static int migrate_folio_unmap(new_folio_t get_new_folio,
 	}
 	locked = true;
 	if (folio_test_mlocked(src))
-		old_page_state |= PAGE_WAS_MLOCKED;
+		old_folio_state |= FOLIO_WAS_MLOCKED;
 
 	if (folio_test_writeback(src)) {
 		/*
@@ -1302,7 +1300,7 @@ static int migrate_folio_unmap(new_folio_t get_new_folio,
 	dst_locked = true;
 
 	if (unlikely(page_has_movable_ops(&src->page))) {
-		__migrate_folio_record(dst, old_page_state, anon_vma);
+		__migrate_folio_record(dst, old_folio_state, anon_vma);
 		return 0;
 	}
 
@@ -1328,11 +1326,11 @@ static int migrate_folio_unmap(new_folio_t get_new_folio,
 		VM_BUG_ON_FOLIO(folio_test_anon(src) &&
 			       !folio_test_ksm(src) && !anon_vma, src);
 		try_to_migrate(src, mode == MIGRATE_ASYNC ? TTU_BATCH_FLUSH : 0);
-		old_page_state |= PAGE_WAS_MAPPED;
+		old_folio_state |= FOLIO_WAS_MAPPED;
 	}
 
 	if (!folio_mapped(src)) {
-		__migrate_folio_record(dst, old_page_state, anon_vma);
+		__migrate_folio_record(dst, old_folio_state, anon_vma);
 		return 0;
 	}
 
@@ -1344,7 +1342,7 @@ static int migrate_folio_unmap(new_folio_t get_new_folio,
 	if (rc == -EAGAIN)
 		ret = NULL;
 
-	migrate_folio_undo_src(src, old_page_state & PAGE_WAS_MAPPED,
+	migrate_folio_undo_src(src, old_folio_state & FOLIO_WAS_MAPPED,
 			       anon_vma, locked, ret);
 	migrate_folio_undo_dst(dst, dst_locked, put_new_folio, private);
 
@@ -1358,13 +1356,13 @@ static int migrate_folio_move(free_folio_t put_new_folio, unsigned long private,
 			      struct list_head *ret)
 {
 	int rc;
-	int old_page_state = 0;
+	int old_folio_state = 0;
 	struct anon_vma *anon_vma = NULL;
 	bool src_deferred_split = false;
 	bool src_partially_mapped = false;
 	struct list_head *prev;
 
-	__migrate_folio_extract(dst, &old_page_state, &anon_vma);
+	__migrate_folio_extract(dst, &old_folio_state, &anon_vma);
 	prev = dst->lru.prev;
 	list_del(&dst->lru);
 
@@ -1395,10 +1393,10 @@ static int migrate_folio_move(free_folio_t put_new_folio, unsigned long private,
 	 * isolated from the unevictable LRU: but this case is the easiest.
 	 */
 	folio_add_lru(dst);
-	if (old_page_state & PAGE_WAS_MLOCKED)
+	if (old_folio_state & FOLIO_WAS_MLOCKED)
 		lru_add_drain();
 
-	if (old_page_state & PAGE_WAS_MAPPED)
+	if (old_folio_state & FOLIO_WAS_MAPPED)
 		remove_migration_ptes(src, dst, 0);
 
 	/*
@@ -1439,11 +1437,11 @@ static int migrate_folio_move(free_folio_t put_new_folio, unsigned long private,
 	 */
 	if (rc == -EAGAIN) {
 		list_add(&dst->lru, prev);
-		__migrate_folio_record(dst, old_page_state, anon_vma);
+		__migrate_folio_record(dst, old_folio_state, anon_vma);
 		return rc;
 	}
 
-	migrate_folio_undo_src(src, old_page_state & PAGE_WAS_MAPPED,
+	migrate_folio_undo_src(src, old_folio_state & FOLIO_WAS_MAPPED,
 			       anon_vma, true, ret);
 	migrate_folio_undo_dst(dst, true, put_new_folio, private);
 
@@ -1777,11 +1775,11 @@ static void migrate_folios_undo(struct list_head *src_folios,
 	dst = list_first_entry(dst_folios, struct folio, lru);
 	dst2 = list_next_entry(dst, lru);
 	list_for_each_entry_safe(folio, folio2, src_folios, lru) {
-		int old_page_state = 0;
+		int old_folio_state = 0;
 		struct anon_vma *anon_vma = NULL;
 
-		__migrate_folio_extract(dst, &old_page_state, &anon_vma);
-		migrate_folio_undo_src(folio, old_page_state & PAGE_WAS_MAPPED,
+		__migrate_folio_extract(dst, &old_folio_state, &anon_vma);
+		migrate_folio_undo_src(folio, old_folio_state & FOLIO_WAS_MAPPED,
 				anon_vma, true, ret_folios);
 		list_del(&dst->lru);
 		migrate_folio_undo_dst(dst, true, put_new_folio, private);

base-commit: 02b045682c74be16c7d1501563f02b0e92d42cdb
-- 
2.43.0