@@ -6,6 +6,7 @@ import (

 	"path/filepath"

 	"strings"

 	"syscall"

+	"time"

 )

 type ChangeType int

@@ -34,6 +35,21 @@ func (change *Change) String() string {

 	return fmt.Sprintf("%s %s", kind, change.Path)

 }

+// Gnu tar and the go tar writer don't have sub-second mtime

+// precision, which is problematic when we apply changes via tar

+// files, we handle this by comparing for exact times, *or* same

+// second count and either a or b having exactly 0 nanoseconds

+func sameFsTime(a, b time.Time) bool {

+	return a == b ||

+		(a.Unix() == b.Unix() &&

+			(a.Nanosecond() == 0 || b.Nanosecond() == 0))

+}

+

+func sameFsTimeSpec(a, b syscall.Timespec) bool {

+	return a.Sec == b.Sec &&

+		(a.Nsec == b.Nsec || a.Nsec == 0 || b.Nsec == 0)

+}

+

 func Changes(layers []string, rw string) ([]Change, error) {

 	var changes []Change

 	err := filepath.Walk(rw, func(path string, f os.FileInfo, err error) error {

@@ -85,7 +101,7 @@ func Changes(layers []string, rw string) ([]Change, error) {

 					// However, if it's a directory, maybe it wasn't actually modified.

 					// If you modify /foo/bar/baz, then /foo will be part of the changed files only because it's the parent of bar

 					if stat.IsDir() && f.IsDir() {

-						if f.Size() == stat.Size() && f.Mode() == stat.Mode() && f.ModTime() == stat.ModTime() {

+						if f.Size() == stat.Size() && f.Mode() == stat.Mode() && sameFsTime(f.ModTime(), stat.ModTime()) {

 							// Both directories are the same, don't record the change

 							return nil

 						}

@@ -181,7 +197,7 @@ func (info *FileInfo) addChanges(oldInfo *FileInfo, changes *[]Change) {

 				oldStat.Rdev != newStat.Rdev ||

 				// Don't look at size for dirs, its not a good measure of change

 				(oldStat.Size != newStat.Size && oldStat.Mode&syscall.S_IFDIR != syscall.S_IFDIR) ||

-				getLastModification(oldStat) != getLastModification(newStat) {

+				!sameFsTimeSpec(getLastModification(oldStat), getLastModification(newStat)) {

 				change := Change{

 					Path: newChild.path(),

 					Kind: ChangeModify,