// When creating file, use the same permissions as original
  mode_t open_mode = mode & (S_IRWXU | S_IRWXG | S_IRWXO);

  // O_WRONLY | O_CREAT | O_TRUNC:
  //   Open file for write and if file does not exist, create the file.
  //   If file exists, truncate its size to 0.
  int dst_fd = open(dst, O_WRONLY | O_CREAT | O_TRUNC, open_mode);
  if (dst_fd < 0) {
    close(src_fd);
    return -1;
  }

  }

  close(fd);
}

static void CreateDir(const TF_Filesystem* filesystem, const char* path,
                      TF_Status* status) {
  if (strlen(path) == 0)
    TF_SetStatus(status, TF_ALREADY_EXISTS, "already exists");
  else if (mkdir(path, /*mode=*/0755) != 0)
    TF_SetStatusFromIOError(status, errno, path);
  else
    TF_SetStatus(status, TF_OK, "");
}

  status->status = c.construction_status();
  if (!status->status.ok()) return;

  if (op_reg_data->shape_inference_fn == nullptr) {
    status->status =
        InvalidArgument("No shape inference function exists for op '",
                        node_def.op(), "', did you forget to define it?");
    return;
  }

  status->status = c.Run(op_reg_data->shape_inference_fn);
  if (!status->status.ok()) return;

  ASSERT_TRUE(TF_GetCode(status.get()) == TF_ALREADY_EXISTS)
      << TF_Message(status.get());

  RegisterLoggingDevice(
      context.get(), "/job:localhost/replica:0/task:0/device:CPU:0",
      /*strict_scope_placement=*/true, &arrived, &executed, status.get());
  ASSERT_TRUE(TF_GetCode(status.get()) == TF_ALREADY_EXISTS)
      << TF_Message(status.get());

Status GradientRegistry::Register(
    const string& op_name, GradientFunctionFactory gradient_function_factory) {
  auto iter = registry_.find(op_name);
  if (iter != registry_.end()) {
    const string error_msg = "Gradient already exists for op: " + op_name + ".";
    return errors::AlreadyExists(error_msg);
  }
  registry_.insert({op_name, gradient_function_factory});
  return absl::OkStatus();
}
Status GradientRegistry::Lookup(

    TF_VLog(3, "CreateDir: directory already exists, not uploading %s", path);
    return TF_SetStatus(status, TF_ALREADY_EXISTS, path);
  }

  auto metadata = gcs_file->gcs_client.InsertObject(
      bucket, object, "",
      // Adding this parameter means HTTP_CODE_PRECONDITION_FAILED
      // will be returned if the object already exists, so avoid reuploading.
      gcs::IfGenerationMatch(0), gcs::Fields(""));

// Validates the operations supplied by the plugin.
//
// Uses the 4 simpler `ValidateHelper(const TF_...*)` to validate each
// individual function table and then checks that the function table for a
// specific file type exists if the plugin offers support for creating that
// type of files.
static Status ValidateOperations(const TF_FilesystemPluginOps* ops) {
  TF_RETURN_IF_ERROR(ValidateHelper(ops->filesystem_ops));

  if (ops_->path_exists == nullptr)
    return errors::Unimplemented(tensorflow::strings::StrCat(
        "Filesystem for ", fname, " does not support FileExists()"));

  UniquePtrTo_TF_Status plugin_status(TF_NewStatus(), TF_DeleteStatus);
  const std::string translated_name = TranslateName(fname);
  ops_->path_exists(filesystem_.get(), translated_name.c_str(),

}

TEST_P(ModularFileSystemTest, TestCreateDirTwice) {
  const std::string dirpath = GetURIForPath("a_dir");
  Status status = env_->CreateDir(dirpath);
  if (!status.ok()) GTEST_SKIP() << "CreateDir() not supported: " << status;

  status = env_->CreateDir(dirpath);
  EXPECT_PRED2(UnimplementedOrReturnsCode, status, Code::ALREADY_EXISTS);
}

            static_cast<TF_Code>(tensorflow::error::DEADLINE_EXCEEDED));
  EXPECT_EQ(TF_NOT_FOUND, static_cast<TF_Code>(tensorflow::error::NOT_FOUND));
  EXPECT_EQ(TF_ALREADY_EXISTS,
            static_cast<TF_Code>(tensorflow::error::ALREADY_EXISTS));
  EXPECT_EQ(TF_PERMISSION_DENIED,
            static_cast<TF_Code>(tensorflow::error::PERMISSION_DENIED));
  EXPECT_EQ(TF_UNAUTHENTICATED,