diff --git a/vendor/github.com/containerd/continuity/fs/diff.go b/vendor/github.com/containerd/continuity/fs/diff.go
index e64f9e73d304..0204f08ab01b 100644
--- a/vendor/github.com/containerd/continuity/fs/diff.go
+++ b/vendor/github.com/containerd/continuity/fs/diff.go
@@ -212,7 +212,7 @@ func diffDirChanges(ctx context.Context, changeFn ChangeFunc, base string, o *di
 		// This block is here to ensure the change is recorded even if the
 		// modify time, mode and size of the parent directory in the rw and ro layers are all equal.
 		// Check https://github.com/docker/docker/pull/13590 for details.
-		if f.IsDir() {
+		if f != nil && f.IsDir() {
 			changedDirs[path] = struct{}{}
 		}
 		if kind == ChangeKindAdd || kind == ChangeKindDelete {
diff --git a/vendor/github.com/containerd/continuity/fs/diff_unix.go b/vendor/github.com/containerd/continuity/fs/diff_unix.go
index 7913af27d903..09b4db8601be 100644
--- a/vendor/github.com/containerd/continuity/fs/diff_unix.go
+++ b/vendor/github.com/containerd/continuity/fs/diff_unix.go
@@ -21,20 +21,82 @@ package fs
 import (
 	"bytes"
 	"os"
+	"strings"
 	"syscall"
 
+	"github.com/containerd/containerd/mount"
 	"github.com/containerd/continuity/sysx"
 	"github.com/pkg/errors"
 )
 
+// deleteChangeOverlay checks if file has been deleted 
+// in overlay fs by checking if file is marked as char device.
+func deleteChangeOverlay(diffDir, path string, f os.FileInfo) (string, error) {
+	if f.Mode()&os.ModeCharDevice != 0 {
+		return path, nil
+	} else {
+		return "", nil
+	}
+}
+
+// getLowerDir returns the list of lower directories from
+// the options of overlay mount, provided no upperdir 
+// exists ( implying readonly overaly)
+func getLowerDir(vfsOptions string) ([]string) {
+	options := strings.Split(vfsOptions, ",")
+	var lowerDir []string
+	for _, opts := range options {
+                if strings.HasPrefix(opts, "lowerdir=") {
+			lowerDir = strings.Split(strings.Split(opts, "lowerdir=")[1], ":")
+                }
+                if strings.HasPrefix(opts, "upperdir=") {
+                        return  []string{}
+                }
+	}
+	return lowerDir
+}
+
 // detectDirDiff returns diff dir options if a directory could
 // be found in the mount info for upper which is the direct
 // diff with the provided lower directory
 func detectDirDiff(upper, lower string) *diffDirOptions {
-	// TODO: get mount options for upper
 	// TODO: detect AUFS
-	// TODO: detect overlay
-	return nil
+	// Implemented only for overlay
+	mountInfoUpper, err := mount.Lookup(upper)
+	if err != nil {
+		return nil
+	}
+	mountInfoLower, err := mount.Lookup(lower)
+	if err != nil {
+		return nil
+	}
+	if mountInfoUpper.FSType != "overlay" {
+		return nil
+	}
+	if mountInfoLower.FSType != "overlay" {
+		return nil
+	}
+	upperLowerDir := getLowerDir(mountInfoUpper.VFSOptions)
+	lowerLowerDir := getLowerDir(mountInfoLower.VFSOptions)
+	if len(lowerLowerDir) != len(upperLowerDir) - 1 {
+		// the mount points differ by more than 1 snapshots.
+		// In this case resort to double diff walk between the 
+		// mount points.
+		return nil
+	}
+	for i, dir := range lowerLowerDir {
+		if upperLowerDir[i+1] != dir {
+			// the lower dirs are not in order. So compare with 
+			// double diff walk.
+			return nil
+		}
+	}
+
+	var options diffDirOptions
+	options.diffDir = upperLowerDir[0]
+	options.deleteChange = deleteChangeOverlay
+
+	return  &options
 }
 
 // compareSysStat returns whether the stats are equivalent,