mm: Convert all PageMovable users to movable_operations

These drivers are rather uncomfortably hammered into the
address_space_operations hole.  They aren't filesystems and don't behave
like filesystems.  They just need their own movable_operations structure,
which we can point to directly from page->mapping.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>

1 files changed, 12 insertions, 12 deletions

diff --git a/mm/migrate.c b/mm/migrate.c
index 6c1ea61f39d8..491f03747832 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -59,7 +59,7 @@
 
 int isolate_movable_page(struct page *page, isolate_mode_t mode)
 {
-	struct address_space *mapping;
+	const struct movable_operations *mops;
 
 	/*
 	 * Avoid burning cycles with pages that are yet under __free_pages(),
@@ -97,10 +97,10 @@ int isolate_movable_page(struct page *page, isolate_mode_t mode)
 	if (!PageMovable(page) || PageIsolated(page))
 		goto out_no_isolated;
 
-	mapping = page_mapping(page);
-	VM_BUG_ON_PAGE(!mapping, page);
+	mops = page_movable_ops(page);
+	VM_BUG_ON_PAGE(!mops, page);
 
-	if (!mapping->a_ops->isolate_page(page, mode))
+	if (!mops->isolate_page(page, mode))
 		goto out_no_isolated;
 
 	/* Driver shouldn't use PG_isolated bit of page->flags */
@@ -120,10 +120,9 @@ out:
 
 static void putback_movable_page(struct page *page)
 {
-	struct address_space *mapping;
+	const struct movable_operations *mops = page_movable_ops(page);
 
-	mapping = page_mapping(page);
-	mapping->a_ops->putback_page(page);
+	mops->putback_page(page);
 	ClearPageIsolated(page);
 }
 
@@ -846,16 +845,15 @@ static int fallback_migrate_page(struct address_space *mapping,
 static int move_to_new_folio(struct folio *dst, struct folio *src,
 				enum migrate_mode mode)
 {
-	struct address_space *mapping;
 	int rc = -EAGAIN;
 	bool is_lru = !__PageMovable(&src->page);
 
 	VM_BUG_ON_FOLIO(!folio_test_locked(src), src);
 	VM_BUG_ON_FOLIO(!folio_test_locked(dst), dst);
 
-	mapping = folio_mapping(src);
-
 	if (likely(is_lru)) {
+		struct address_space *mapping = folio_mapping(src);
+
 		if (!mapping)
 			rc = migrate_page(mapping, &dst->page, &src->page, mode);
 		else if (mapping->a_ops->migratepage)
@@ -872,6 +870,8 @@ static int move_to_new_folio(struct folio *dst, struct folio *src,
 			rc = fallback_migrate_page(mapping, &dst->page,
 							&src->page, mode);
 	} else {
+		const struct movable_operations *mops;
+
 		/*
 		 * In case of non-lru page, it could be released after
 		 * isolation step. In that case, we shouldn't try migration.
@@ -883,8 +883,8 @@ static int move_to_new_folio(struct folio *dst, struct folio *src,
 			goto out;
 		}
 
-		rc = mapping->a_ops->migratepage(mapping, &dst->page,
-						&src->page, mode);
+		mops = page_movable_ops(&src->page);
+		rc = mops->migrate_page(&dst->page, &src->page, mode);
 		WARN_ON_ONCE(rc == MIGRATEPAGE_SUCCESS &&
 				!folio_test_isolated(src));
 	}