remove pkg/testutil/loopback_linux.go and use continuity/testutil/loopback

Signed-off-by: Akihiro Suda <suda.akihiro@lab.ntt.co.jp>

pkg/testutil/loopback_linux.go

@@ -1,72 +0,0 @@
-// +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 testutil
-
-import (
-	"io/ioutil"
-	"os"
-	"os/exec"
-	"strings"
-
-	"github.com/pkg/errors"
-	"github.com/sirupsen/logrus"
-)
-
-// NewLoopback creates a loopback device, and returns its device name (/dev/loopX), and its clean-up function.
-func NewLoopback(size int64) (string, func() error, error) {
-	// create temporary file for the disk image
-	file, err := ioutil.TempFile("", "containerd-test-loopback")
-	if err != nil {
-		return "", nil, errors.Wrap(err, "could not create temporary file for loopback")
-	}
-
-	if err := file.Truncate(size); err != nil {
-		file.Close()
-		os.Remove(file.Name())
-		return "", nil, errors.Wrap(err, "failed to resize temp file")
-	}
-	file.Close()
-
-	// create device
-	losetup := exec.Command("losetup", "--find", "--show", file.Name())
-	p, err := losetup.Output()
-	if err != nil {
-		os.Remove(file.Name())
-		return "", nil, errors.Wrap(err, "loopback setup failed")
-	}
-
-	deviceName := strings.TrimSpace(string(p))
-	logrus.Debugf("Created loop device %s (using %s)", deviceName, file.Name())
-
-	cleanup := func() error {
-		// detach device
-		logrus.Debugf("Removing loop device %s", deviceName)
-		losetup := exec.Command("losetup", "--detach", deviceName)
-		err := losetup.Run()
-		if err != nil {
-			return errors.Wrapf(err, "Could not remove loop device %s", deviceName)
-		}
-
-		// remove file
-		logrus.Debugf("Removing temporary file %s", file.Name())
-		return os.Remove(file.Name())
-	}
-
-	return deviceName, cleanup, nil
-}