moby--moby/pkg/system/filesys_windows.go

// +build windows

package system

import (
	"os"
	"regexp"
	"syscall"
)

// MkdirAll implementation that is volume path aware for Windows.
func MkdirAll(path string, perm os.FileMode) error {
	if re := regexp.MustCompile(`^\\\\\?\\Volume{[a-z0-9-]+}$`); re.MatchString(path) {
		return nil
	}

	// The rest of this method is copied from os.MkdirAll and should be kept
	// as-is to ensure compatibility.

	// Fast path: if we can tell whether path is a directory or file, stop with success or error.
	dir, err := os.Stat(path)
	if err == nil {
		if dir.IsDir() {
			return nil
		}
		return &os.PathError{
			Op:   "mkdir",
			Path: path,
			Err:  syscall.ENOTDIR,
		}
	}

	// Slow path: make sure parent exists and then call Mkdir for path.
	i := len(path)
	for i > 0 && os.IsPathSeparator(path[i-1]) { // Skip trailing path separator.
		i--
	}

	j := i
	for j > 0 && !os.IsPathSeparator(path[j-1]) { // Scan backward over element.
		j--
	}

	if j > 1 {
		// Create parent
		err = MkdirAll(path[0:j-1], perm)
		if err != nil {
			return err
		}
	}

	// Parent now exists; invoke Mkdir and use its result.
	err = os.Mkdir(path, perm)
	if err != nil {
		// Handle arguments like "foo/." by
		// double-checking that directory doesn't exist.
		dir, err1 := os.Lstat(path)
		if err1 == nil && dir.IsDir() {
			return nil
		}
		return err
	}
	return nil
}