write_context
struct write_context *wc = context;
struct write_context wc = {.no_wait = no_wait, .write_list = write_list};
struct write_if_not_dirtied_context *write_context = context;
if (page->generation == write_context->generation) {
acquire_vio(waiter, write_context->zone);
enqueue_page(page, write_context->zone);