It will be more clean to use CONFIG_MIGRATION to cover nfs' private
.migratepage in nfs_file_aops like we do in other part of nfs
operations.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
        .invalidatepage = nfs_invalidate_page,
        .releasepage = nfs_release_page,
        .direct_IO = nfs_direct_IO,
+#ifdef CONFIG_MIGRATION
        .migratepage = nfs_migrate_page,
+#endif
        .launder_page = nfs_launder_page,
        .is_dirty_writeback = nfs_check_dirty_writeback,
        .error_remove_page = generic_error_remove_page,
 
 }
 #endif
 
-
 #ifdef CONFIG_MIGRATION
 extern int nfs_migrate_page(struct address_space *,
                struct page *, struct page *, enum migrate_mode);
-#else
-#define nfs_migrate_page NULL
 #endif
 
 static inline int