[PATCH] mm: update outdated comments for removed scan_swap_map_slots()

From: Kexin Sun

Date: Sat Mar 21 2026 - 07:02:15 EST


The function scan_swap_map_slots() was removed in commit
0ff67f990bd4 ("mm, swap: remove swap slot cache").

The three comments referencing it simply noted that ->flags can be
updated non-atomically by scan_swap_map_slots() to justify a
data_race() annotation. Since the function no longer exists, drop
the parenthetical reference while keeping the data_race()
justification intact: ->flags can still be updated non-atomically
by other paths (e.g., swapoff clearing SWP_WRITEOK).

Assisted-by: unnamed:deepseek-v3.2 coccinelle
Signed-off-by: Kexin Sun <kexinsun@xxxxxxxxxxxxxxxx>
---
mm/page_io.c | 4 ++--
mm/vmscan.c | 2 +-
2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/mm/page_io.c b/mm/page_io.c
index a2c034660c80..330abc5ab7b4 100644
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -450,14 +450,14 @@ void __swap_writepage(struct folio *folio, struct swap_iocb **swap_plug)

VM_BUG_ON_FOLIO(!folio_test_swapcache(folio), folio);
/*
- * ->flags can be updated non-atomically (scan_swap_map_slots),
+ * ->flags can be updated non-atomically,
* but that will never affect SWP_FS_OPS, so the data_race
* is safe.
*/
if (data_race(sis->flags & SWP_FS_OPS))
swap_writepage_fs(folio, swap_plug);
/*
- * ->flags can be updated non-atomically (scan_swap_map_slots),
+ * ->flags can be updated non-atomically,
* but that will never affect SWP_SYNCHRONOUS_IO, so the data_race
* is safe.
*/
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 0fc9373e8251..0758ef3b100b 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1070,7 +1070,7 @@ static bool may_enter_fs(struct folio *folio, gfp_t gfp_mask)
/*
* We can "enter_fs" for swap-cache with only __GFP_IO
* providing this isn't SWP_FS_OPS.
- * ->flags can be updated non-atomically (scan_swap_map_slots),
+ * ->flags can be updated non-atomically,
* but that will never affect SWP_FS_OPS, so the data_race
* is safe.
*/
--
2.25.1