package daemon
 
 import (
 	"bufio"

 	"fmt"
 	"io"

 	"os"

 	"regexp"

 	"strings"
 

 	"github.com/docker/docker/pkg/fileutils"

 	"github.com/docker/docker/pkg/mount"

 	"github.com/sirupsen/logrus"

 )
 

 // On Linux, plugins use a static path for storing execution state,
 // instead of deriving path from daemon's exec-root. This is because
 // plugin socket files are created here and they cannot exceed max
 // path length of 108 bytes.
 func getPluginExecRoot(root string) string {
 	return "/run/docker/plugins"
 }
 

 func (daemon *Daemon) cleanupMountsByID(id string) error {
 	logrus.Debugf("Cleaning up old mountid %s: start.", id)
 	f, err := os.Open("/proc/self/mountinfo")
 	if err != nil {
 		return err
 	}
 	defer f.Close()
 
 	return daemon.cleanupMountsFromReaderByID(f, id, mount.Unmount)
 }
 
 func (daemon *Daemon) cleanupMountsFromReaderByID(reader io.Reader, id string, unmount func(target string) error) error {
 	if daemon.root == "" {
 		return nil
 	}
 	var errors []string

 
 	regexps := getCleanPatterns(id)

 	sc := bufio.NewScanner(reader)
 	for sc.Scan() {

 		if fields := strings.Fields(sc.Text()); len(fields) >= 4 {
 			if mnt := fields[4]; strings.HasPrefix(mnt, daemon.root) {
 				for _, p := range regexps {
 					if p.MatchString(mnt) {
 						if err := unmount(mnt); err != nil {
 							logrus.Error(err)
 							errors = append(errors, err.Error())
 						}
 					}

 				}
 			}
 		}
 	}
 
 	if err := sc.Err(); err != nil {
 		return err
 	}
 
 	if len(errors) > 0 {

 		return fmt.Errorf("Error cleaning up mounts:\n%v", strings.Join(errors, "\n"))

 	}
 

 	logrus.Debugf("Cleaning up old mountid %v: done.", id)

 	return nil
 }
 

 // cleanupMounts umounts shm/mqueue mounts for old containers
 func (daemon *Daemon) cleanupMounts() error {

 	return daemon.cleanupMountsByID("")

 }
 

 func getCleanPatterns(id string) (regexps []*regexp.Regexp) {
 	var patterns []string
 	if id == "" {
 		id = "[0-9a-f]{64}"
 		patterns = append(patterns, "containers/"+id+"/shm")

 	}

 	patterns = append(patterns, "aufs/mnt/"+id+"$", "overlay/"+id+"/merged$", "zfs/graph/"+id+"$")
 	for _, p := range patterns {
 		r, err := regexp.Compile(p)
 		if err == nil {
 			regexps = append(regexps, r)

 		}
 	}

 	return

 }

 
 func getRealPath(path string) (string, error) {
 	return fileutils.ReadSymlinkedDirectory(path)
 }