page_io: return proper error codes for swap_read_folio_zeromap() (fix)

Commit Message

Nhat Pham March 7, 2025, 11:34 p.m. UTC

Fix the comments for swap_read_folio_zeromap().

Suggested-by: Yosry Ahmed <[e-mail]>
Signed-off-by: Nhat Pham <[e-mail]>
---
 mm/page_io.c | 10 ++--------
 1 file changed, 2 insertions(+), 8 deletions(-)

Patch

diff --git a/mm/page_io.c b/mm/page_io.c
index 48ed1e810392..30ec132c801b 100644
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -521,9 +521,8 @@  static void sio_read_complete(struct kiocb *iocb, long ret)
  *
  *  -ENOENT: the folio is entirely not zeromapped. The folio remains locked.
  *
- *  -EINVAL: some of the subpages in the folio are zeromaped, but not all of
- *  them. This is an error because we don't currently support a large folio
- *  that is partially in the zeromap. The folio is unlocked, but NOT marked
+ *  -EINVAL: The folio is partially in the zeromap, which is not
+ *  currently supported. The folio is unlocked, but NOT marked
  *  up-to-date, so that an IO error is emitted (e.g. do_swap_page() will
  *  sigbus).
  */
@@ -533,11 +532,6 @@  static int swap_read_folio_zeromap(struct folio *folio)
 	struct obj_cgroup *objcg;
 	bool is_zeromap;
 
-	/*
-	 * Swapping in a large folio that is partially in the zeromap is not
-	 * currently handled. Return -EINVAL without marking the folio uptodate so
-	 * that an IO error is emitted (e.g. do_swap_page() will sigbus).
-	 */
 	if (WARN_ON_ONCE(swap_zeromap_batch(folio->swap, nr_pages,
 			&is_zeromap) != nr_pages)) {
 		folio_unlock(folio);