[PATCH v1 08/29] mm/migrate: rename putback_movable_folio() to putback_movable_ops_page()

David Hildenbrand
2025-06-30T13:00:50Z

... and factor the complete handling of movable_ops pages out.
Convert it similar to isolate_movable_ops_page().

While at it, convert the VM_BUG_ON_FOLIO() into a VM_WARN_ON_PAGE().

Signed-off-by: David Hildenbrand <david@redhat.com>
---
mm/migrate.c | 37 ++++++++++++++++++++++++-------------
1 file changed, 24 insertions(+), 13 deletions(-)

diff --git a/mm/migrate.c b/mm/migrate.c
index d4b4a7eefb6bd..d97f7cd137e63 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -133,12 +133,30 @@ bool isolate_movable_ops_page(struct page *page, isolate_mode_t mode)
return false;
}

-static void putback_movable_folio(struct folio *folio)
+/**
+ * putback_movable_ops_page - putback an isolated movable_ops page
+ * @page: The isolated page.
+ *
+ * Putback an isolated movable_ops page.
+ *
+ * After the page was putback, it might get freed instantly.
+ */
+static void putback_movable_ops_page(struct page *page)
{
- const struct movable_operations *mops = folio_movable_ops(folio);
-
- mops->putback_page(&folio->page);
- folio_clear_isolated(folio);
+ /*
+ * TODO: these pages will not be folios in the future. All
+ * folio dependencies will have to be removed.
+ */
+ struct folio *folio = page_folio(page);
+
+ VM_WARN_ON_ONCE_PAGE(!PageIsolated(page), page);
+ folio_lock(folio);
+ /* If the page was released by it's owner, there is nothing to do. */
+ if (PageMovable(page))
+ page_movable_ops(page)->putback_page(page);
+ ClearPageIsolated(page);
+ folio_unlock(folio);
+ folio_put(folio);
}

/*
@@ -166,14 +184,7 @@ void putback_movable_pages(struct list_head *l)
* have PAGE_MAPPING_MOVABLE.
*/
if (unlikely(__folio_test_movable(folio))) {
- VM_BUG_ON_FOLIO(!folio_test_isolated(folio), folio);
- folio_lock(folio);
- if (folio_test_movable(folio))
- putback_movable_folio(folio);
- else
- folio_clear_isolated(folio);
- folio_unlock(folio);
- folio_put(folio);
+ putback_movable_ops_page(&folio->page);
} else {
node_stat_mod_folio(folio, NR_ISOLATED_ANON +
folio_is_file_lru(folio), -folio_nr_pages(folio));
--
2.49.0