open_cb           617 test/test-fs.c   r = uv_fs_open(loop, &open_req1, "test_file2", O_RDWR, 0, open_cb);
open_cb           629 test/test-fs.c   r = uv_fs_open(loop, &open_req1, "test_file2", O_RDONLY, 0, open_cb);