Setup: NUFA with 8 subvolumes, server and client being different processes on each host.

Both touch and mkdir return -1, EINVAL.

The errno is being set in the following lines in nufa.c

nufa_local_lookup_cbk:

 if (op_ret == -1)
                goto out

out:
  if (!local->hashed_subvol) {
    gf_log (this->name, GF_LOG_DEBUG,
	    "no subvolume in layout for path=%s",
	    local->loc.path);

	op_errno = EINVAL;
	goto err;
  }

One of the subvolumes (3rd - brick3) is down.