mm: Export migrate_page_move_mapping and migrate_page_copy

[ Upstream commit 1118dce7 ]

Export these symbols such that UBIFS can implement
->migratepage.

Cc: stable@vger.kernel.org
Signed-off-by: Richard Weinberger <richard@nod.at>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

mm/migrate.c

@@ -421,6 +421,7 @@ int migrate_page_move_mapping(struct address_space *mapping,
 
 	return MIGRATEPAGE_SUCCESS;
 }
+EXPORT_SYMBOL(migrate_page_move_mapping);
 
 /*
  * The expected number of remaining references is the same as that
@@ -580,6 +581,7 @@ void migrate_page_copy(struct page *newpage, struct page *page)
 	if (PageWriteback(newpage))
 		end_page_writeback(newpage);
 }
+EXPORT_SYMBOL(migrate_page_copy);
 
 /************************************************************
  *                    Migration functions