cri: support blockio class in pod and container annotations

This patch adds support for a container annotation and two separate
pod annotations for controlling the blockio class of containers.

The container annotation can be used by a CRI client:
  "io.kubernetes.cri.blockio-class"

Pod annotations specify the blockio class in the K8s pod spec level:
  "blockio.resources.beta.kubernetes.io/pod"
  (pod-wide default for all containers within)

  "blockio.resources.beta.kubernetes.io/container.<container_name>"
  (container-specific overrides)

Correspondingly, this patch adds support for --blockio-class and
--blockio-config-file to ctr, too.

This implementation follows the resource class annotation pattern
introduced in RDT and merged in commit 893701220.

Signed-off-by: Antti Kervinen <antti.kervinen@intel.com>

services/tasks/blockio_linux.go

@@ -0,0 +1,50 @@
+//go:build linux
+// +build linux
+
+/*
+   Copyright The containerd Authors.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+package tasks
+
+import (
+	"fmt"
+
+	"github.com/containerd/containerd/log"
+
+	"github.com/intel/goresctrl/pkg/blockio"
+)
+
+var blockIOEnabled bool
+
+func BlockIOEnabled() bool { return blockIOEnabled }
+
+func initBlockIO(configFilePath string) error {
+	blockIOEnabled = false
+
+	if configFilePath == "" {
+		log.L.Debug("No blockio config file specified, blockio not configured")
+		return nil
+	}
+
+	if err := blockio.SetConfigFromFile(configFilePath, true); err != nil {
+		return fmt.Errorf("blockio not enabled: %w", err)
+	}
+
+	blockIOEnabled = true
+
+	return nil
+
+}