NW_BLKSIZ
bufs[i] = malloc(NW_BLKSIZ);
fill_pattern(bufs[i], NW_BLKSIZ, (uint8_t)i);
cbs[i].aio_nbytes = NW_BLKSIZ;
off += (off_t)NW_BLKSIZ;
ATF_REQUIRE_EQ(NW_BLKSIZ, done);