feat: Use Win32 API to implement Filesystem API to reduce PowerShell overhead (library version)

pkg/filesystem/hostapi/hostapi.go

@@ -4,7 +4,6 @@ import (
 	"fmt"
 	"os"
 	"path/filepath"
-	"strings"
 
 	"github.com/kubernetes-csi/csi-proxy/v2/pkg/utils"
 )
@@ -49,17 +48,6 @@ func (filesystemAPI) PathExists(path string) (bool, error) {
 	return pathExists(path)
 }
 
-func pathValid(path string) (bool, error) {
-	cmd := `Test-Path $Env:remotepath`
-	cmdEnv := fmt.Sprintf("remotepath=%s", path)
-	output, err := utils.RunPowershellCmd(cmd, cmdEnv)
-	if err != nil {
-		return false, fmt.Errorf("returned output: %s, error: %v", string(output), err)
-	}
-
-	return strings.HasPrefix(strings.ToLower(string(output)), "true"), nil
-}
-
 // PathValid determines whether all elements of a path exist
 //
 //	https://docs.microsoft.com/en-us/powershell/module/microsoft.powershell.management/test-path?view=powershell-7
@@ -68,7 +56,7 @@ func pathValid(path string) (bool, error) {
 //
 //	e.g. in a SMB server connection, if password is changed, connection will be lost, this func will return false
 func (filesystemAPI) PathValid(path string) (bool, error) {
-	return pathValid(path)
+	return utils.IsPathValid(path)
 }
 
 // Mkdir makes a dir with `os.MkdirAll`.
@@ -124,18 +112,23 @@ func (filesystemAPI) IsSymlink(tgt string) (bool, error) {
 	// This code is similar to k8s.io/kubernetes/pkg/util/mount except the pathExists usage.
 	// Also in a remote call environment the os error cannot be passed directly back, hence the callers
 	// are expected to perform the isExists check before calling this call in CSI proxy.
-	stat, err := os.Lstat(tgt)
+	isSymlink, err := utils.IsPathSymlink(tgt)
+	if err != nil {
+		return false, err
+	}
+
+	// mounted folder created by SetVolumeMountPoint may still report ModeSymlink == 0
+	mountedFolder, err := utils.IsMountedFolder(tgt)
 	if err != nil {
 		return false, err
 	}
 
-	// If its a link and it points to an existing file then its a mount point.
-	if stat.Mode()&os.ModeSymlink != 0 {
+	if isSymlink || mountedFolder {
 		target, err := os.Readlink(tgt)
 		if err != nil {
 			return false, fmt.Errorf("readlink error: %v", err)
 		}
-		exists, err := pathExists(target)
+		exists, err := utils.PathExists(target)
 		if err != nil {
 			return false, err
 		}

pkg/system/hostapi/hostapi.go

@@ -35,7 +35,7 @@ const (
 var (
 	serviceStateCheckInternal = 200 * time.Millisecond
 	serviceStateCheckTimeout  = 30 * time.Second
-	errTimedOut               = errors.New("Timed out")
+	errTimedOut               = errors.New("timed out")
 )
 
 type ServiceManager interface {

pkg/utils/utils.go

@@ -3,7 +3,6 @@ package utils
 import (
 	"fmt"
 	"os"
-	"os/exec"
 	"strings"
 
 	"github.com/pkg/errors"
@@ -18,22 +17,33 @@ const (
 	LongPathPrefix = `\\?\`
 )
 
-func RunPowershellCmd(command string, envs ...string) ([]byte, error) {
-	command = fmt.Sprintf("$global:ProgressPreference = 'SilentlyContinue'; %s", command)
-	cmd := exec.Command("powershell", "-Mta", "-NoProfile", "-Command", command)
-	cmd.Env = append(os.Environ(), envs...)
-	klog.V(8).Infof("Executing command: %q", cmd.String())
-	out, err := cmd.CombinedOutput()
-	return out, err
-}
-
 func EnsureLongPath(path string) string {
 	if !strings.HasPrefix(path, LongPathPrefix) {
 		path = LongPathPrefix + path
 	}
 	return path
 }
 
+func IsPathValid(path string) (bool, error) {
+	pathString, err := windows.UTF16PtrFromString(path)
+	if err != nil {
+		return false, fmt.Errorf("invalid path: %w", err)
+	}
+
+	attrs, err := windows.GetFileAttributes(pathString)
+	if err != nil {
+		if errors.Is(err, windows.ERROR_PATH_NOT_FOUND) || errors.Is(err, windows.ERROR_FILE_NOT_FOUND) || errors.Is(err, windows.ERROR_INVALID_NAME) {
+			return false, nil
+		}
+
+		// GetFileAttribute returns user or password incorrect for a disconnected SMB connection after the password is changed
+		return false, fmt.Errorf("failed to get path %s attribute: %w", path, err)
+	}
+
+	klog.V(6).Infof("Path %s attribute: %O", path, attrs)
+	return attrs != windows.INVALID_FILE_ATTRIBUTES, nil
+}
+
 // IsMountedFolder checks whether the `path` is a mounted folder.
 func IsMountedFolder(path string) (bool, error) {
 	// https://learn.microsoft.com/en-us/windows/win32/fileio/determining-whether-a-directory-is-a-volume-mount-point