mm/migrate: Add folio_migrate_copy()

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@infradead.org>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>

diff --git a/include/linux/migrate.h b/include/linux/migrate.h
index aa875b8..0d2aeb9 100644 (file)
--- a/include/linux/migrate.h
+++ b/include/linux/migrate.h
@@ -58,6 +58,7 @@ 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 c28cace..93d5fbe 100644 (file)
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -912,7 +912,7 @@ 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 3f00ad9..2ccd8f2 100644 (file)
--- 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 95dc7b8..6378c10 100644 (file)
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -5302,7 +5302,7 @@ 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 f6e0017..433c453 100644 (file)
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -614,16 +614,12 @@ 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
@@ -651,7 +647,7 @@ 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 bf86083..e58151a 100644 (file)
--- a/mm/util.c
+++ b/mm/util.c
@@ -747,13 +747,26 @@ int __page_mapcount(struct page *page)
 }
 EXPORT_SYMBOL_GPL(__page_mapcount);
 
-void copy_huge_page(struct page *dst, struct page *src)
+/**
+ * folio_copy - Copy the contents of one folio to another.
+ * @dst: Folio to copy to.
+ * @src: Folio to copy from.
+ *
+ * The bytes in the folio represented by @src are copied to @dst.
+ * Assumes the caller has validated that @dst is at least as large as @src.
+ * Can be called in atomic context for order-0 folios, but if the folio is
+ * larger, it may sleep.
+ */
+void folio_copy(struct folio *dst, struct folio *src)
 {
-       unsigned i, nr = compound_nr(src);
+       long i = 0;
+       long nr = folio_nr_pages(src);
 
-       for (i = 0; i < nr; i++) {
+       for (;;) {
+               copy_highpage(folio_page(dst, i), folio_page(src, i));
+               if (++i == nr)
+                       break;
                cond_resched();
-               copy_highpage(nth_page(dst, i), nth_page(src, i));
        }
 }