fly: use pkg/mountinfo for mountinfo parsing

stage1_fly/gc/main.go

@@ -23,10 +23,6 @@ import (
 	rktlog "github.com/coreos/rkt/pkg/log"
 )
 
-const (
-	mountinfoPath = "/proc/self/mountinfo"
-)
-
 var (
 	debug bool
 

stage1_fly/run/main.go

@@ -69,38 +69,6 @@ var (
 	dnsConfMode *pkgflag.PairList
 )
 
-func getHostMounts() (map[string]struct{}, error) {
-	hostMounts := map[string]struct{}{}
-
-	mi, err := os.Open("/proc/self/mountinfo")
-	if err != nil {
-		return nil, err
-	}
-	defer mi.Close()
-
-	sc := bufio.NewScanner(mi)
-	for sc.Scan() {
-		var (
-			discard    string
-			mountPoint string
-		)
-
-		_, err := fmt.Sscanf(sc.Text(),
-			"%s %s %s %s %s",
-			&discard, &discard, &discard, &discard, &mountPoint,
-		)
-		if err != nil {
-			return nil, err
-		}
-
-		hostMounts[mountPoint] = struct{}{}
-	}
-	if sc.Err() != nil {
-		return nil, errwrap.Wrap(errors.New("problem parsing mountinfo"), sc.Err())
-	}
-	return hostMounts, nil
-}
-
 func init() {
 	flag.BoolVar(&debug, "debug", false, "Run in debug mode")
 
@@ -206,10 +174,14 @@ func evaluateMounts(rfs string, app string, p *stage1commontypes.Pod) ([]flyMoun
 	}
 
 	// Gather host mounts which we make MS_SHARED if passed as a volume source
-	hostMounts, err := getHostMounts()
+	hostMounts := map[string]struct{}{}
+	mnts, err := mountinfo.ParseMounts(0)
 	if err != nil {
 		return nil, errwrap.Wrap(errors.New("can't gather host mounts"), err)
 	}
+	for _, m := range mnts {
+		hostMounts[m.MountPoint] = struct{}{}
+	}
 
 	argFlyMounts := []flyMount{}
 	for _, tuple := range namedVolumeMounts {