[PATCH v14 12/39] mm/migrate: Add folio_migrate_copy()

["Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>]

This is the folio equivalent of migrate_page_copy(), which is retained
as a wrapper for filesystems which are not yet converted to folios.
Also convert copy_huge_page() to folio_copy().

Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Reviewed-by: Zi Yan <ziy@xxxxxxxxxx>
---
 include/linux/migrate.h |  1 +
 include/linux/mm.h      |  2 +-
 mm/folio-compat.c       |  6 ++++++
 mm/hugetlb.c            |  2 +-
 mm/migrate.c            | 14 +++++---------
 mm/util.c               |  6 +++---
 6 files changed, 17 insertions(+), 14 deletions(-)

diff --git a/include/linux/migrate.h b/include/linux/migrate.h
index ba0a554b3eae..6a01de9faff5 100644
--- a/include/linux/migrate.h
+++ b/include/linux/migrate.h
@@ -52,6 +52,7 @@ extern int migrate_huge_page_move_mapping(struct address_space *mapping,
 extern int migrate_page_move_mapping(struct address_space *mapping,
 		struct page *newpage, struct page *page, int extra_count);
 void folio_migrate_flags(struct folio *newfolio, struct folio *folio);
+void folio_migrate_copy(struct folio *newfolio, struct folio *folio);
 int folio_migrate_mapping(struct address_space *mapping,
 		struct folio *newfolio, struct folio *folio, int extra_count);
 #else
diff --git a/include/linux/mm.h b/include/linux/mm.h
index deb0f5efaa65..23276330ef4f 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -911,7 +911,7 @@ void __put_page(struct page *page);
 void put_pages_list(struct list_head *pages);
 
 void split_page(struct page *page, unsigned int order);
-void copy_huge_page(struct page *dst, struct page *src);
+void folio_copy(struct folio *dst, struct folio *src);
 
 /*
  * Compound pages have a destructor function.  Provide a
diff --git a/mm/folio-compat.c b/mm/folio-compat.c
index 3f00ad92d1ff..2ccd8f213fc4 100644
--- a/mm/folio-compat.c
+++ b/mm/folio-compat.c
@@ -64,4 +64,10 @@ void migrate_page_states(struct page *newpage, struct page *page)
 	folio_migrate_flags(page_folio(newpage), page_folio(page));
 }
 EXPORT_SYMBOL(migrate_page_states);
+
+void migrate_page_copy(struct page *newpage, struct page *page)
+{
+	folio_migrate_copy(page_folio(newpage), page_folio(page));
+}
+EXPORT_SYMBOL(migrate_page_copy);
 #endif
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 924553aa8f78..b46f9d09aa94 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -5200,7 +5200,7 @@ int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm,
 			*pagep = NULL;
 			goto out;
 		}
-		copy_huge_page(page, *pagep);
+		folio_copy(page_folio(page), page_folio(*pagep));
 		put_page(*pagep);
 		*pagep = NULL;
 	}
diff --git a/mm/migrate.c b/mm/migrate.c
index a86be2bfc9a1..36cdae0a1235 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -613,16 +613,12 @@ void folio_migrate_flags(struct folio *newfolio, struct folio *folio)
 }
 EXPORT_SYMBOL(folio_migrate_flags);
 
-void migrate_page_copy(struct page *newpage, struct page *page)
+void folio_migrate_copy(struct folio *newfolio, struct folio *folio)
 {
-	if (PageHuge(page) || PageTransHuge(page))
-		copy_huge_page(newpage, page);
-	else
-		copy_highpage(newpage, page);
-
-	migrate_page_states(newpage, page);
+	folio_copy(newfolio, folio);
+	folio_migrate_flags(newfolio, folio);
 }
-EXPORT_SYMBOL(migrate_page_copy);
+EXPORT_SYMBOL(folio_migrate_copy);
 
 /************************************************************
  *                    Migration functions
@@ -650,7 +646,7 @@ int migrate_page(struct address_space *mapping,
 		return rc;
 
 	if (mode != MIGRATE_SYNC_NO_COPY)
-		migrate_page_copy(newpage, page);
+		folio_migrate_copy(newfolio, folio);
 	else
 		folio_migrate_flags(newfolio, folio);
 	return MIGRATEPAGE_SUCCESS;
diff --git a/mm/util.c b/mm/util.c
index 149537120a91..904a75612307 100644
--- a/mm/util.c
+++ b/mm/util.c
@@ -728,13 +728,13 @@ int __page_mapcount(struct page *page)
 }
 EXPORT_SYMBOL_GPL(__page_mapcount);
 
-void copy_huge_page(struct page *dst, struct page *src)
+void folio_copy(struct folio *dst, struct folio *src)
 {
-	unsigned i, nr = compound_nr(src);
+	unsigned i, nr = folio_nr_pages(src);
 
 	for (i = 0; i < nr; i++) {
 		cond_resched();
-		copy_highpage(nth_page(dst, i), nth_page(src, i));
+		copy_highpage(folio_page(dst, i), folio_page(src, i));
 	}
 }
 
-- 
2.30.2