snapshot/devmapper: use losetup in mount package

No need to use the private losetup command line wrapper package.
The generic package provides the same functionality.

Signed-off-by: Peng Tao <bergwolf@hyper.sh>

snapshots/devmapper/dmsetup/dmsetup_test.go

@@ -29,8 +29,8 @@ import (
 	"gotest.tools/v3/assert"
 	is "gotest.tools/v3/assert/cmp"
 
+	"github.com/containerd/containerd/mount"
 	"github.com/containerd/containerd/pkg/testutil"
-	"github.com/containerd/containerd/snapshots/devmapper/losetup"
 )
 
 const (
@@ -55,16 +55,13 @@ func TestDMSetup(t *testing.T) {
 	metaImage, loopMetaDevice := createLoopbackDevice(t, tempDir)
 
 	defer func() {
-		err = losetup.RemoveLoopDevicesAssociatedWithImage(dataImage)
+		err = mount.DetachLoopDevice(loopDataDevice, loopMetaDevice)
-		assert.NilError(t, err, "failed to detach loop devices for data image: %s", dataImage)
+		assert.NilError(t, err, "failed to detach loop devices for data image: %s and meta image: %s", dataImage, metaImage)
-
-		err = losetup.RemoveLoopDevicesAssociatedWithImage(metaImage)
-		assert.NilError(t, err, "failed to detach loop devices for meta image: %s", metaImage)
 	}()
 
 	t.Run("CreatePool", func(t *testing.T) {
 		err := CreatePool(testPoolName, loopDataDevice, loopMetaDevice, 128)
-		assert.NilError(t, err, "failed to create thin-pool")
+		assert.NilError(t, err, "failed to create thin-pool with %s %s", loopDataDevice, loopMetaDevice)
 
 		table, err := Table(testPoolName)
 		t.Logf("table: %s", table)
@@ -201,7 +198,7 @@ func createLoopbackDevice(t *testing.T, dir string) (string, string) {
 
 	imagePath := file.Name()
 
-	loopDevice, err := losetup.AttachLoopDevice(imagePath)
+	loopDevice, err := mount.AttachLoopDevice(imagePath)
 	assert.NilError(t, err)
 
 	return imagePath, loopDevice

snapshots/devmapper/losetup/losetup.go

@@ -1,92 +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 losetup
-
-import (
-	"os/exec"
-	"strings"
-
-	"github.com/pkg/errors"
-	"golang.org/x/sys/unix"
-)
-
-// FindAssociatedLoopDevices returns a list of loop devices attached to a given image
-func FindAssociatedLoopDevices(imagePath string) ([]string, error) {
-	output, err := losetup("--list", "--output", "NAME", "--associated", imagePath)
-	if err != nil {
-		return nil, errors.Wrapf(err, "failed to get loop devices: '%s'", output)
-	}
-
-	if output == "" {
-		return []string{}, nil
-	}
-
-	items := strings.Split(output, "\n")
-	if len(items) <= 1 {
-		return []string{}, nil
-	}
-
-	// Skip header with column names
-	return items[1:], nil
-}
-
-// AttachLoopDevice finds first available loop device and associates it with an image.
-func AttachLoopDevice(imagePath string) (string, error) {
-	return losetup("--find", "--show", imagePath)
-}
-
-// DetachLoopDevice detaches loop devices
-func DetachLoopDevice(loopDevice ...string) error {
-	args := append([]string{"--detach"}, loopDevice...)
-	_, err := losetup(args...)
-	return err
-}
-
-// RemoveLoopDevicesAssociatedWithImage detaches all loop devices attached to a given sparse image
-func RemoveLoopDevicesAssociatedWithImage(imagePath string) error {
-	loopDevices, err := FindAssociatedLoopDevices(imagePath)
-	if err != nil {
-		return err
-	}
-
-	for _, loopDevice := range loopDevices {
-		if err = DetachLoopDevice(loopDevice); err != nil && err != unix.ENOENT {
-			return err
-		}
-	}
-
-	return nil
-}
-
-// losetup is a wrapper around losetup command line tool
-func losetup(args ...string) (string, error) {
-	cmd := exec.Command("losetup", args...)
-	cmd.Env = append(cmd.Env, "LANG=C")
-	data, err := cmd.CombinedOutput()
-	output := string(data)
-	if err != nil {
-		if strings.Contains(output, "No such file or directory") || strings.Contains(output, "No such device") {
-			return "", unix.ENOENT
-		}
-
-		return "", errors.Wrapf(err, "losetup %s\nerror: %s\n", strings.Join(args, " "), output)
-	}
-
-	return strings.TrimSuffix(output, "\n"), err
-}

snapshots/devmapper/losetup/losetup_test.go

@@ -1,124 +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 losetup
-
-import (
-	"io/ioutil"
-	"os"
-	"testing"
-
-	"github.com/docker/go-units"
-	"golang.org/x/sys/unix"
-	"gotest.tools/v3/assert"
-	is "gotest.tools/v3/assert/cmp"
-
-	"github.com/containerd/containerd/pkg/testutil"
-)
-
-func TestLosetup(t *testing.T) {
-	testutil.RequiresRoot(t)
-
-	var (
-		imagePath   = createSparseImage(t)
-		loopDevice1 string
-		loopDevice2 string
-	)
-
-	defer func() {
-		err := os.Remove(imagePath)
-		assert.NilError(t, err)
-	}()
-
-	t.Run("AttachLoopDevice", func(t *testing.T) {
-		dev1, err := AttachLoopDevice(imagePath)
-		assert.NilError(t, err)
-		assert.Assert(t, dev1 != "")
-
-		dev2, err := AttachLoopDevice(imagePath)
-		assert.NilError(t, err)
-		assert.Assert(t, dev2 != dev1, "should attach different loop device")
-
-		loopDevice1 = dev1
-		loopDevice2 = dev2
-	})
-
-	t.Run("AttachEmptyLoopDevice", func(t *testing.T) {
-		_, err := AttachLoopDevice("")
-		assert.Assert(t, err != nil, "shouldn't attach empty path")
-	})
-
-	t.Run("FindAssociatedLoopDevices", func(t *testing.T) {
-		devices, err := FindAssociatedLoopDevices(imagePath)
-		assert.NilError(t, err)
-		assert.Assert(t, is.Len(devices, 2), "unexpected number of attached devices")
-		assert.Assert(t, is.Contains(devices, loopDevice1))
-		assert.Assert(t, is.Contains(devices, loopDevice2))
-	})
-
-	t.Run("FindAssociatedLoopDevicesForInvalidImage", func(t *testing.T) {
-		devices, err := FindAssociatedLoopDevices("")
-		assert.NilError(t, err)
-		assert.Assert(t, is.Len(devices, 0))
-	})
-
-	t.Run("DetachLoopDevice", func(t *testing.T) {
-		err := DetachLoopDevice(loopDevice2)
-		assert.NilError(t, err, "failed to detach %q", loopDevice2)
-	})
-
-	t.Run("DetachEmptyDevice", func(t *testing.T) {
-		err := DetachLoopDevice("")
-		assert.Assert(t, err != nil, "shouldn't detach empty path")
-	})
-
-	t.Run("RemoveLoopDevicesAssociatedWithImage", func(t *testing.T) {
-		err := RemoveLoopDevicesAssociatedWithImage(imagePath)
-		assert.NilError(t, err)
-
-		devices, err := FindAssociatedLoopDevices(imagePath)
-		assert.NilError(t, err)
-		assert.Assert(t, is.Len(devices, 0))
-	})
-
-	t.Run("RemoveLoopDevicesAssociatedWithInvalidImage", func(t *testing.T) {
-		err := RemoveLoopDevicesAssociatedWithImage("")
-		assert.NilError(t, err)
-	})
-
-	t.Run("DetachInvalidDevice", func(t *testing.T) {
-		err := DetachLoopDevice("/dev/loop_invalid_idx")
-		assert.Equal(t, unix.ENOENT, err)
-	})
-}
-
-func createSparseImage(t *testing.T) string {
-	file, err := ioutil.TempFile("", "losetup-tests-")
-	assert.NilError(t, err)
-
-	size, err := units.RAMInBytes("16Mb")
-	assert.NilError(t, err)
-
-	err = file.Truncate(size)
-	assert.NilError(t, err)
-
-	err = file.Close()
-	assert.NilError(t, err)
-
-	return file.Name()
-}

snapshots/devmapper/pool_device_test.go

@@ -31,7 +31,6 @@ import (
 	"github.com/containerd/containerd/mount"
 	"github.com/containerd/containerd/pkg/testutil"
 	"github.com/containerd/containerd/snapshots/devmapper/dmsetup"
-	"github.com/containerd/containerd/snapshots/devmapper/losetup"
 	"github.com/docker/go-units"
 	"github.com/sirupsen/logrus"
 	"gotest.tools/v3/assert"
@@ -74,7 +73,7 @@ func TestPoolDevice(t *testing.T) {
 
 	defer func() {
 		// Detach loop devices and remove images
-		err := losetup.DetachLoopDevice(loopDataDevice, loopMetaDevice)
+		err := mount.DetachLoopDevice(loopDataDevice, loopMetaDevice)
 		assert.NilError(t, err)
 
 		err = os.RemoveAll(tempDir)
@@ -306,7 +305,7 @@ func createLoopbackDevice(t *testing.T, dir string) (string, string) {
 
 	imagePath := file.Name()
 
-	loopDevice, err := losetup.AttachLoopDevice(imagePath)
+	loopDevice, err := mount.AttachLoopDevice(imagePath)
 	assert.NilError(t, err)
 
 	return imagePath, loopDevice

snapshots/devmapper/snapshotter_test.go

@@ -37,7 +37,6 @@ import (
 	"github.com/containerd/containerd/pkg/testutil"
 	"github.com/containerd/containerd/snapshots"
 	"github.com/containerd/containerd/snapshots/devmapper/dmsetup"
-	"github.com/containerd/containerd/snapshots/devmapper/losetup"
 	"github.com/containerd/containerd/snapshots/testsuite"
 )
 
@@ -70,7 +69,7 @@ func TestSnapshotterSuite(t *testing.T) {
 		removePool := func() error {
 			result := multierror.Append(
 				snap.pool.RemovePool(ctx),
-				losetup.DetachLoopDevice(loopDataDevice, loopMetaDevice))
+				mount.DetachLoopDevice(loopDataDevice, loopMetaDevice))
 
 			return result.ErrorOrNil()
 		}