runtime: Base64 encode the direct volume mountInfo path

This is to avoid accidentally deleting multiple volumes.

Fixes #4020

Signed-off-by: Feng Wang <feng.wang@databricks.com>

src/runtime/cmd/kata-runtime/kata-volume.go

@@ -54,7 +54,10 @@ var addCommand = cli.Command{
 		},
 	},
 	Action: func(c *cli.Context) error {
-		return volume.Add(volumePath, mountInfo)
+		if err := volume.Add(volumePath, mountInfo); err != nil {
+			return cli.NewExitError(err.Error(), 1)
+		}
+		return nil
 	},
 }
 
@@ -69,7 +72,10 @@ var removeCommand = cli.Command{
 		},
 	},
 	Action: func(c *cli.Context) error {
-		return volume.Remove(volumePath)
+		if err := volume.Remove(volumePath); err != nil {
+			return cli.NewExitError(err.Error(), 1)
+		}
+		return nil
 	},
 }
 
@@ -86,9 +92,8 @@ var statsCommand = cli.Command{
 	Action: func(c *cli.Context) (string, error) {
 		stats, err := Stats(volumePath)
 		if err != nil {
-			return "", err
+			return "", cli.NewExitError(err.Error(), 1)
 		}
-
 		return string(stats), nil
 	},
 }
@@ -109,7 +114,10 @@ var resizeCommand = cli.Command{
 		},
 	},
 	Action: func(c *cli.Context) error {
-		return Resize(volumePath, size)
+		if err := Resize(volumePath, size); err != nil {
+			return cli.NewExitError(err.Error(), 1)
+		}
+		return nil
 	},
 }
 

src/runtime/pkg/direct-volume/utils.go

@@ -6,13 +6,13 @@
 package volume
 
 import (
+	b64 "encoding/base64"
 	"encoding/json"
 	"errors"
 	"fmt"
 	"io/ioutil"
 	"os"
 	"path/filepath"
-	"strings"
 )
 
 const (
@@ -37,19 +37,20 @@ type MountInfo struct {
 
 // Add writes the mount info of a direct volume into a filesystem path known to Kata Container.
 func Add(volumePath string, mountInfo string) error {
-	volumeDir := filepath.Join(kataDirectVolumeRootPath, volumePath)
+	volumeDir := filepath.Join(kataDirectVolumeRootPath, b64.URLEncoding.EncodeToString([]byte(volumePath)))
 	stat, err := os.Stat(volumeDir)
-	if err != nil && !errors.Is(err, os.ErrNotExist) {
-		return err
-	}
-	if stat != nil && !stat.IsDir() {
-		return fmt.Errorf("%s should be a directory", volumeDir)
-	}
-	if errors.Is(err, os.ErrNotExist) {
+	if err != nil {
+		if !errors.Is(err, os.ErrNotExist) {
+			return err
+		}
 		if err := os.MkdirAll(volumeDir, 0700); err != nil {
 			return err
 		}
 	}
+	if stat != nil && !stat.IsDir() {
+		return fmt.Errorf("%s should be a directory", volumeDir)
+	}
+
 	var deserialized MountInfo
 	if err := json.Unmarshal([]byte(mountInfo), &deserialized); err != nil {
 		return err
@@ -60,14 +61,12 @@ func Add(volumePath string, mountInfo string) error {
 
 // Remove deletes the direct volume path including all the files inside it.
 func Remove(volumePath string) error {
-	// Find the base of the volume path to delete the whole volume path
-	base := strings.SplitN(volumePath, string(os.PathSeparator), 2)[0]
-	return os.RemoveAll(filepath.Join(kataDirectVolumeRootPath, base))
+	return os.RemoveAll(filepath.Join(kataDirectVolumeRootPath, b64.URLEncoding.EncodeToString([]byte(volumePath))))
 }
 
 // VolumeMountInfo retrieves the mount info of a direct volume.
 func VolumeMountInfo(volumePath string) (*MountInfo, error) {
-	mountInfoFilePath := filepath.Join(kataDirectVolumeRootPath, volumePath, mountInfoFileName)
+	mountInfoFilePath := filepath.Join(kataDirectVolumeRootPath, b64.URLEncoding.EncodeToString([]byte(volumePath)), mountInfoFileName)
 	if _, err := os.Stat(mountInfoFilePath); err != nil {
 		return nil, err
 	}
@@ -84,16 +83,17 @@ func VolumeMountInfo(volumePath string) (*MountInfo, error) {
 
 // RecordSandboxId associates a sandbox id with a direct volume.
 func RecordSandboxId(sandboxId string, volumePath string) error {
-	mountInfoFilePath := filepath.Join(kataDirectVolumeRootPath, volumePath, mountInfoFileName)
+	encodedPath := b64.URLEncoding.EncodeToString([]byte(volumePath))
+	mountInfoFilePath := filepath.Join(kataDirectVolumeRootPath, encodedPath, mountInfoFileName)
 	if _, err := os.Stat(mountInfoFilePath); err != nil {
 		return err
 	}
 
-	return ioutil.WriteFile(filepath.Join(kataDirectVolumeRootPath, volumePath, sandboxId), []byte(""), 0600)
+	return ioutil.WriteFile(filepath.Join(kataDirectVolumeRootPath, encodedPath, sandboxId), []byte(""), 0600)
 }
 
 func GetSandboxIdForVolume(volumePath string) (string, error) {
-	files, err := ioutil.ReadDir(filepath.Join(kataDirectVolumeRootPath, volumePath))
+	files, err := ioutil.ReadDir(filepath.Join(kataDirectVolumeRootPath, b64.URLEncoding.EncodeToString([]byte(volumePath))))
 	if err != nil {
 		return "", err
 	}

src/runtime/pkg/direct-volume/utils_test.go

@@ -6,6 +6,7 @@
 package volume
 
 import (
+	b64 "encoding/base64"
 	"encoding/json"
 	"errors"
 	"os"
@@ -22,7 +23,6 @@ func TestAdd(t *testing.T) {
 	assert.Nil(t, err)
 	defer os.RemoveAll(kataDirectVolumeRootPath)
 	var volumePath = "/a/b/c"
-	var basePath = "a"
 	actual := MountInfo{
 		VolumeType: "block",
 		Device:     "/dev/sda",
@@ -42,14 +42,15 @@ func TestAdd(t *testing.T) {
 	assert.Equal(t, expected.FsType, actual.FsType)
 	assert.Equal(t, expected.Options, actual.Options)
 
+	_, err = os.Stat(filepath.Join(kataDirectVolumeRootPath, b64.URLEncoding.EncodeToString([]byte(volumePath))))
+	assert.Nil(t, err)
 	// Remove the file
 	err = Remove(volumePath)
 	assert.Nil(t, err)
-	_, err = os.Stat(filepath.Join(kataDirectVolumeRootPath, basePath))
+	_, err = os.Stat(filepath.Join(kataDirectVolumeRootPath, b64.URLEncoding.EncodeToString([]byte(volumePath))))
 	assert.True(t, errors.Is(err, os.ErrNotExist))
-
-	// Test invalid mount info json
-	assert.Error(t, Add(volumePath, "{invalid json}"))
+	_, err = os.Stat(filepath.Join(kataDirectVolumeRootPath))
+	assert.Nil(t, err)
 }
 
 func TestRecordSandboxId(t *testing.T) {

src/runtime/virtcontainers/kata_agent.go

@@ -1549,11 +1549,9 @@ func (k *kataAgent) handleBlkOCIMounts(c *Container, spec *specs.Spec) ([]*grpc.
 		// Each device will be mounted at a unique location within the VM only once. Mounting
 		// to the container specific location is handled within the OCI spec. Let's ensure that
 		// the storage mount point is unique for each device. This is then utilized as the source
-		// in the OCI spec. If multiple containers mount the same block device, it's refcounted inside
+		// in the OCI spec. If multiple containers mount the same block device, it's ref-counted inside
 		// the guest by Kata agent.
-		filename := b64.StdEncoding.EncodeToString([]byte(vol.Source))
-		// Make the base64 encoding path safe.
-		filename = strings.ReplaceAll(filename, "/", "_")
+		filename := b64.URLEncoding.EncodeToString([]byte(vol.Source))
 		path := filepath.Join(kataGuestSandboxStorageDir(), filename)
 
 		// Update applicable OCI mount source