package docker

 
 import (
 	"fmt"

 	"github.com/dotcloud/docker/utils"

 	"os"

 	"os/exec"

 	"path/filepath"
 	"syscall"
 	"time"
 )
 
 func Unmount(target string) error {

 	if err := exec.Command("auplink", target, "flush").Run(); err != nil {
 		utils.Debugf("[warning]: couldn't run auplink before unmount: %s", err)
 	}

 	if err := syscall.Unmount(target, 0); err != nil {
 		return err
 	}
 	// Even though we just unmounted the filesystem, AUFS will prevent deleting the mntpoint
 	// for some time. We'll just keep retrying until it succeeds.
 	for retries := 0; retries < 1000; retries++ {
 		err := os.Remove(target)
 		if err == nil {
 			// rm mntpoint succeeded
 			return nil
 		}
 		if os.IsNotExist(err) {
 			// mntpoint doesn't exist anymore. Success.
 			return nil
 		}
 		// fmt.Printf("(%v) Remove %v returned: %v\n", retries, target, err)
 		time.Sleep(10 * time.Millisecond)
 	}
 	return fmt.Errorf("Umount: Failed to umount %v", target)
 }
 
 func Mounted(mountpoint string) (bool, error) {
 	mntpoint, err := os.Stat(mountpoint)
 	if err != nil {
 		if os.IsNotExist(err) {
 			return false, nil
 		}
 		return false, err
 	}
 	parent, err := os.Stat(filepath.Join(mountpoint, ".."))
 	if err != nil {
 		return false, err
 	}
 	mntpointSt := mntpoint.Sys().(*syscall.Stat_t)
 	parentSt := parent.Sys().(*syscall.Stat_t)
 	return mntpointSt.Dev != parentSt.Dev, nil
 }