Failing closed after maximum retry is achieved to avoid inifite recursion

Author: knabben

pkg/os/volume/api.go

@@ -54,6 +54,7 @@ var (
 	// PS C:\disks> (Get-Disk -Number 1 | Get-Partition | Get-Volume).UniqueId
 	// \\?\Volume{452e318a-5cde-421e-9831-b9853c521012}\
 	VolumeRegexp = regexp.MustCompile(`Volume\{[\w-]*\}`)
+
 )
 
 // New - Construct a new Volume API Implementation.
@@ -268,7 +269,7 @@ func (VolumeAPI) GetDiskNumberFromVolumeID(volumeID string) (uint32, error) {
 
 // GetVolumeIDFromTargetPath - gets the volume ID given a mount point, the function is recursive until it find a volume or errors out
 func (VolumeAPI) GetVolumeIDFromTargetPath(mount string) (string, error) {
-	volumeString, err := getTarget(mount)
+	volumeString, err := getTarget(mount, 0)
 
 	if err != nil {
 		return "", fmt.Errorf("error getting the volume for the mount %s, internal error %v", mount, err)
@@ -277,22 +278,28 @@ func (VolumeAPI) GetVolumeIDFromTargetPath(mount string) (string, error) {
 	return volumeString, nil
 }
 
-func getTarget(mount string) (string, error) {
+func getTarget(mount string, retry int) (string, error) {
 	cmd := `(Get-Item -Path $Env:mountpath).Target`
 	cmdEnv := fmt.Sprintf("mountpath=%s", mount)
 	out, err := utils.RunPowershellCmd(cmd, cmdEnv)
-	if err != nil || len(out) == 0 {
+	if err != nil || len(out) == 0  {
 		return "", fmt.Errorf("error getting volume from mount. cmd: %s, output: %s, error: %v", cmd, string(out), err)
 	}
+    if retry >= 256 {
+		return "", fmt.Errorf("maximum recursion reached, cmd: %s, output: %s, :retry %d", cmd, string(out), retry)
+	}
+
 	volumeString := strings.TrimSpace(string(out))
+    klog.V(8).Infof("retry: %d, volumeString: %s", retry, volumeString)
+
 	if !strings.HasPrefix(volumeString, "Volume") {
-		return getTarget(volumeString)
+		return getTarget(volumeString, retry+1)
 	}
 
 	return ensureVolumePrefix(volumeString), nil
 }
 
-// GetVolumeIDFromTargetPath returns the volume id of a given target path.
+// GetClosestVolumeIDFromTargetPath returns the volume id of a given target path.
 func (VolumeAPI) GetClosestVolumeIDFromTargetPath(targetPath string) (string, error) {
 	volumeString, err := findClosestVolume(targetPath)
 

pkg/os/volume/api_test.go

@@ -0,0 +1,32 @@
+package volume
+
+import (
+	"github.com/stretchr/testify/assert"
+	"testing"
+)
+
+func TestGetTarget(t *testing.T) {
+	tests := []struct {
+		mountpath      string
+		expectedResult string
+		expectError    bool
+		counter        int
+	}{
+		{
+			"c:\\",
+			"",
+			true,
+			1,
+		},
+	}
+	for _, test := range tests {
+		target, err := getTarget(test.mountpath, test.counter)
+		if test.expectError {
+			assert.NotNil(t, err, "Expect error during getTarget(%s)", test.mountpath)
+		} else {
+			assert.Nil(t, err, "Expect error is nil during getTarget(%s)", test.mountpath)
+		}
+		assert.Equal(t, target, test.expectedResult, "Expect result not equal with getTarget(%s) return: %q, expected: %s, error: %v",
+			test.mountpath, target, test.expectedResult, err)
+	}
+}