WO_DRAIN_IO
[WO_DRAIN_IO] = 'd',
drbd_bump_write_ordering(connection->resource, NULL, WO_DRAIN_IO);
wo = WO_DRAIN_IO;
if (wo == WO_DRAIN_IO && !dc->disk_drain)
[WO_DRAIN_IO] = "drain",
case WO_DRAIN_IO: