From c70089ebb32fa6c6755f151dd54498c9f0ac5dc0 Mon Sep 17 00:00:00 2001
From: Kir Kolyshkin <kolyshkin@gmail.com>
Date: Wed, 17 Apr 2019 19:56:48 -0700
Subject: [PATCH] aufs.Cleanup: optimize

Do not use filepath.Walk() as there's no requirement to recursively
go into every directory under mnt -- a (non-recursive) list of
directories in mnt is sufficient.

With filepath.Walk(), in case some container will fail to unmount,
it'll go through the whole container filesystem which is both
excessive and useless.

This is similar to commit f1a459229724f5e8e440b49f ("devmapper.shutdown:
optimize")

While at it, raise the priority of "unmount error" message from debug
to a warning. Note we don't have to explicitly add `m` as unmount error (from
pkg/mount) will have it.

Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
(cherry picked from commit 8fda12c6078ed5c86be0822a7a980c6fbc9220bf)
Upstream-commit: b85d4a4f09badf40201ef7fcbd5b930de216190d
Component: engine
---
 .../engine/daemon/graphdriver/aufs/aufs.go    | 25 ++++++++-----------
 1 file changed, 11 insertions(+), 14 deletions(-)

diff --git a/components/engine/daemon/graphdriver/aufs/aufs.go b/components/engine/daemon/graphdriver/aufs/aufs.go
index 9a0a6207f0..bbd19a82b0 100644
--- a/components/engine/daemon/graphdriver/aufs/aufs.go
+++ b/components/engine/daemon/graphdriver/aufs/aufs.go
@@ -573,23 +573,20 @@ func (a *Driver) mounted(mountpoint string) (bool, error) {
 
 // Cleanup aufs and unmount all mountpoints
 func (a *Driver) Cleanup() error {
-	var dirs []string
-	if err := filepath.Walk(a.mntPath(), func(path string, info os.FileInfo, err error) error {
-		if err != nil {
-			return err
-		}
-		if !info.IsDir() {
-			return nil
-		}
-		dirs = append(dirs, path)
-		return nil
-	}); err != nil {
-		return err
+	dir := a.mntPath()
+	files, err := ioutil.ReadDir(dir)
+	if err != nil {
+		return errors.Wrap(err, "aufs readdir error")
 	}
+	for _, f := range files {
+		if !f.IsDir() {
+			continue
+		}
+
+		m := path.Join(dir, f.Name())
 
-	for _, m := range dirs {
 		if err := a.unmount(m); err != nil {
-			logger.Debugf("error unmounting %s: %s", m, err)
+			logger.WithError(err).WithField("method", "Cleanup()").Warn()
 		}
 	}
 	return mount.RecursiveUnmount(a.root)