NFS4_READ_AHEAD
case NFS4_READ_AHEAD:
args->a_io = NFS4_READ_AHEAD;
if (mi->mi_async_reqs[NFS4_READ_AHEAD] == NULL) {
mi->mi_async_reqs[NFS4_READ_AHEAD] = args;
mi->mi_async_tail[NFS4_READ_AHEAD] = args;
mi->mi_async_tail[NFS4_READ_AHEAD]->a_next = args;
mi->mi_async_tail[NFS4_READ_AHEAD] = args;
if (args->a_io == NFS4_READ_AHEAD && mi->mi_max_threads > 0) {