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From f09346578021c12069b6deb9487a1462b8d28a83 Mon Sep 17 00:00:00 2001
From: Nalin Dahyabhai <nalin@redhat.com>
Date: Thu, 21 Nov 2019 15:32:41 -0500
Subject: [PATCH 1/3] bind: don't complain about missing mountpoints

When we go to unmount a tree of mounts, if one of the directories isn't
there, instead of returning an error as before, log a debug message and
keep going.

Signed-off-by: Nalin Dahyabhai <nalin@redhat.com>
---
 bind/mount.go | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/bind/mount.go b/bind/mount.go
index e1ae323b9f..adde901fd1 100644
--- a/bind/mount.go
+++ b/bind/mount.go
@@ -264,6 +264,10 @@ func UnmountMountpoints(mountpoint string, mountpointsToRemove []string) error {
 		mount := getMountByID(id)
 		// check if this mountpoint is mounted
 		if err := unix.Lstat(mount.Mountpoint, &st); err != nil {
+			if os.IsNotExist(err) {
+				logrus.Debugf("mountpoint %q is not present(?), skipping", mount.Mountpoint)
+				continue
+			}
 			return errors.Wrapf(err, "error checking if %q is mounted", mount.Mountpoint)
 		}
 		if mount.Major != int(unix.Major(st.Dev)) || mount.Minor != int(unix.Minor(st.Dev)) {

From c5fb681a6082b78c422eb3531667dc6d607a9355 Mon Sep 17 00:00:00 2001
From: Nalin Dahyabhai <nalin@redhat.com>
Date: Fri, 22 Nov 2019 14:22:26 -0500
Subject: [PATCH 2/3] chroot: Unmount with MNT_DETACH instead of
 UnmountMountpoints()

Unmounting the rootfs with MNT_DETACH should unmount everything below
it, so we don't need to use the more exhaustive method that our bind
package uses for its bind mounts.

Signed-off-by: Nalin Dahyabhai <nalin@redhat.com>
---
 chroot/run.go | 25 +++++++++++++++----------
 1 file changed, 15 insertions(+), 10 deletions(-)

diff --git a/chroot/run.go b/chroot/run.go
index fbccbcdb0d..76ac78d1ff 100644
--- a/chroot/run.go
+++ b/chroot/run.go
@@ -15,6 +15,7 @@ import (
 	"strings"
 	"sync"
 	"syscall"
+	"time"
 	"unsafe"
 
 	"github.com/containers/buildah/bind"
@@ -1002,12 +1003,19 @@ func isDevNull(dev os.FileInfo) bool {
 // callback that will clean up its work.
 func setupChrootBindMounts(spec *specs.Spec, bundlePath string) (undoBinds func() error, err error) {
 	var fs unix.Statfs_t
-	removes := []string{}
 	undoBinds = func() error {
-		if err2 := bind.UnmountMountpoints(spec.Root.Path, removes); err2 != nil {
-			logrus.Warnf("pkg/chroot: error unmounting %q: %v", spec.Root.Path, err2)
-			if err == nil {
-				err = err2
+		if err2 := unix.Unmount(spec.Root.Path, unix.MNT_DETACH); err2 != nil {
+			retries := 0
+			for (err2 == unix.EBUSY || err2 == unix.EAGAIN) && retries < 50 {
+				time.Sleep(50 * time.Millisecond)
+				err2 = unix.Unmount(spec.Root.Path, unix.MNT_DETACH)
+				retries++
+			}
+			if err2 != nil {
+				logrus.Warnf("pkg/chroot: error unmounting %q (retried %d times): %v", spec.Root.Path, retries, err2)
+				if err == nil {
+					err = err2
+				}
 			}
 		}
 		return err
@@ -1096,6 +1104,7 @@ func setupChrootBindMounts(spec *specs.Spec, bundlePath string) (undoBinds func(
 	// Add /sys/fs/selinux to the set of masked paths, to ensure that we don't have processes
 	// attempting to interact with labeling, when they aren't allowed to do so.
 	spec.Linux.MaskedPaths = append(spec.Linux.MaskedPaths, "/sys/fs/selinux")
+
 	// Bind mount in everything we've been asked to mount.
 	for _, m := range spec.Mounts {
 		// Skip anything that we just mounted.
@@ -1141,13 +1150,11 @@ func setupChrootBindMounts(spec *specs.Spec, bundlePath string) (undoBinds func(
 			if !os.IsNotExist(err) {
 				return undoBinds, errors.Wrapf(err, "error examining %q for mounting in mount namespace", target)
 			}
-			// The target isn't there yet, so create it, and make a
-			// note to remove it later.
+			// The target isn't there yet, so create it.
 			if srcinfo.IsDir() {
 				if err = os.MkdirAll(target, 0111); err != nil {
 					return undoBinds, errors.Wrapf(err, "error creating mountpoint %q in mount namespace", target)
 				}
-				removes = append(removes, target)
 			} else {
 				if err = os.MkdirAll(filepath.Dir(target), 0111); err != nil {
 					return undoBinds, errors.Wrapf(err, "error ensuring parent of mountpoint %q (%q) is present in mount namespace", target, filepath.Dir(target))
@@ -1157,7 +1164,6 @@ func setupChrootBindMounts(spec *specs.Spec, bundlePath string) (undoBinds func(
 					return undoBinds, errors.Wrapf(err, "error creating mountpoint %q in mount namespace", target)
 				}
 				file.Close()
-				removes = append(removes, target)
 			}
 		}
 		requestFlags := bindFlags
@@ -1266,7 +1272,6 @@ func setupChrootBindMounts(spec *specs.Spec, bundlePath string) (undoBinds func(
 		if err := os.Mkdir(roEmptyDir, 0700); err != nil {
 			return undoBinds, errors.Wrapf(err, "error creating empty directory %q", roEmptyDir)
 		}
-		removes = append(removes, roEmptyDir)
 	}
 
 	// Set up any masked paths that we need to.  If we're running inside of

From ec1be6a51941e10b5316c911ef97c88940f7c095 Mon Sep 17 00:00:00 2001
From: Nalin Dahyabhai <nalin@redhat.com>
Date: Fri, 22 Nov 2019 14:52:25 -0500
Subject: [PATCH 3/3] overlay.bats typo: fuse-overlays should be fuse-overlayfs

Signed-off-by: Nalin Dahyabhai <nalin@redhat.com>
---
 tests/overlay.bats | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tests/overlay.bats b/tests/overlay.bats
index 04056f6804..7cc2d0c622 100644
--- a/tests/overlay.bats
+++ b/tests/overlay.bats
@@ -3,14 +3,14 @@
 load helpers
 
 @test "overlay specific level" {
-  if test \! -e /usr/bin/fuse-overlays -a  "$BUILDAH_ISOLATION" = "rootless"; then
+  if test \! -e /usr/bin/fuse-overlayfs -a "$BUILDAH_ISOLATION" = "rootless"; then
     skip "BUILDAH_ISOLATION = $BUILDAH_ISOLATION" and no /usr/bin/fuse-overlayfs present
   fi
   image=alpine
   mkdir ${TESTDIR}/lower
   touch ${TESTDIR}/lower/foo
 
-cid=$(buildah --log-level=error from -v ${TESTDIR}/lower:/lower:O --quiet --signature-policy ${TESTSDIR}/policy.json $image)
+  cid=$(buildah --log-level=error from -v ${TESTDIR}/lower:/lower:O --quiet --signature-policy ${TESTSDIR}/policy.json $image)
 
   # This should succeed
   run_buildah --log-level=error run $cid ls /lower/foo