@@ -118,6 +118,8 @@ Config provides the base accessible fields for working with V0 plugin format

 - **`propagatedMount`** *string*

    path to be mounted as rshared, so that mounts under that path are visible to docker. This is useful for volume plugins.

+   This path will be bind-mounted outisde of the plugin rootfs so it's contents

+   are preserved on upgrade.

 - **`env`** *PluginEnv array*

@@ -434,6 +434,9 @@ func (s *DockerSuite) TestPluginUpgrade(c *check.C) {

 	pluginV2 := "cpuguy83/docker-volume-driver-plugin-local:v2"

 	dockerCmd(c, "plugin", "install", "--grant-all-permissions", plugin)

+	dockerCmd(c, "volume", "create", "--driver", plugin, "bananas")

+	dockerCmd(c, "run", "--rm", "-v", "bananas:/apple", "busybox", "sh", "-c", "touch /apple/core")

+

 	out, _, err := dockerCmdWithError("plugin", "upgrade", "--grant-all-permissions", plugin, pluginV2)

 	c.Assert(err, checker.NotNil, check.Commentf(out))

 	c.Assert(out, checker.Contains, "disabled before upgrading")

@@ -445,7 +448,7 @@ func (s *DockerSuite) TestPluginUpgrade(c *check.C) {

 	_, err = os.Stat(filepath.Join(testEnv.DockerBasePath(), "plugins", id, "rootfs", "v2"))

 	c.Assert(os.IsNotExist(err), checker.True, check.Commentf(out))

-	dockerCmd(c, "plugin", "disable", plugin)

+	dockerCmd(c, "plugin", "disable", "-f", plugin)

 	dockerCmd(c, "plugin", "upgrade", "--grant-all-permissions", "--skip-remote-check", plugin, pluginV2)

 	// make sure "v2" file exists

@@ -453,4 +456,6 @@ func (s *DockerSuite) TestPluginUpgrade(c *check.C) {

 	c.Assert(err, checker.IsNil)

 	dockerCmd(c, "plugin", "enable", plugin)

+	dockerCmd(c, "volume", "inspect", "bananas")

+	dockerCmd(c, "run", "--rm", "-v", "bananas:/apple", "busybox", "sh", "-c", "ls -lh /apple/core")

 }

@@ -13,6 +13,7 @@ import (

 	"os"

 	"path"

 	"path/filepath"

+	"sort"

 	"strings"

 	"github.com/Sirupsen/logrus"

@@ -25,6 +26,7 @@ import (

 	"github.com/docker/docker/image"

 	"github.com/docker/docker/layer"

 	"github.com/docker/docker/pkg/chrootarchive"

+	"github.com/docker/docker/pkg/mount"

 	"github.com/docker/docker/pkg/pools"

 	"github.com/docker/docker/pkg/progress"

 	"github.com/docker/docker/plugin/v2"

@@ -597,6 +599,9 @@ func (pm *Manager) Remove(name string, config *types.PluginRmConfig) error {

 	id := p.GetID()

 	pm.config.Store.Remove(p)

 	pluginDir := filepath.Join(pm.config.Root, id)

+	if err := recursiveUnmount(pm.config.Root); err != nil {

+		logrus.WithField("dir", pm.config.Root).WithField("id", id).Warn(err)

+	}

 	if err := os.RemoveAll(pluginDir); err != nil {

 		logrus.Warnf("unable to remove %q from plugin remove: %v", pluginDir, err)

 	}

@@ -604,6 +609,43 @@ func (pm *Manager) Remove(name string, config *types.PluginRmConfig) error {

 	return nil

 }

+func getMounts(root string) ([]string, error) {

+	infos, err := mount.GetMounts()

+	if err != nil {

+		return nil, errors.Wrap(err, "failed to read mount table while performing recursive unmount")

+	}

+

+	var mounts []string

+	for _, m := range infos {

+		if strings.HasPrefix(m.Mountpoint, root) {

+			mounts = append(mounts, m.Mountpoint)

+		}

+	}

+

+	return mounts, nil

+}

+

+func recursiveUnmount(root string) error {

+	mounts, err := getMounts(root)

+	if err != nil {

+		return err

+	}

+

+	// sort in reverse-lexicographic order so the root mount will always be last

+	sort.Sort(sort.Reverse(sort.StringSlice(mounts)))

+

+	for i, m := range mounts {

+		if err := mount.Unmount(m); err != nil {

+			if i == len(mounts)-1 {

+				return errors.Wrapf(err, "error performing recursive unmount on %s", root)

+			}

+			logrus.WithError(err).WithField("mountpoint", m).Warn("could not unmount")

+		}

+	}

+

+	return nil

+}

+

 // Set sets plugin args

 func (pm *Manager) Set(name string, args []string) error {

 	p, err := pm.config.Store.GetV2Plugin(name)

@@ -145,6 +145,10 @@ func (pm *Manager) StateChanged(id string, e libcontainerd.StateInfo) error {

 			if err := mount.Unmount(p.PropagatedMount); err != nil {

 				logrus.Warnf("Could not unmount %s: %v", p.PropagatedMount, err)

 			}

+			propRoot := filepath.Join(filepath.Dir(p.Rootfs), "propagated-mount")

+			if err := mount.Unmount(propRoot); err != nil {

+				logrus.Warn("Could not unmount %s: %v", propRoot, err)

+			}

 		}

 		if restart {

@@ -193,6 +197,27 @@ func (pm *Manager) reload() error { // todo: restore

 			for _, typ := range p.PluginObj.Config.Interface.Types {

 				if (typ.Capability == "volumedriver" || typ.Capability == "graphdriver") && typ.Prefix == "docker" && strings.HasPrefix(typ.Version, "1.") {

 					if p.PluginObj.Config.PropagatedMount != "" {

+						propRoot := filepath.Join(filepath.Dir(p.Rootfs), "propagated-mount")

+

+						// check if we need to migrate an older propagated mount from before

+						// these mounts were stored outside the plugin rootfs

+						if _, err := os.Stat(propRoot); os.IsNotExist(err) {

+							if _, err := os.Stat(p.PropagatedMount); err == nil {

+								// make sure nothing is mounted here

+								// don't care about errors

+								mount.Unmount(p.PropagatedMount)

+								if err := os.Rename(p.PropagatedMount, propRoot); err != nil {

+									logrus.WithError(err).WithField("dir", propRoot).Error("error migrating propagated mount storage")

+								}

+								if err := os.MkdirAll(p.PropagatedMount, 0755); err != nil {

+									logrus.WithError(err).WithField("dir", p.PropagatedMount).Error("error migrating propagated mount storage")

+								}

+							}

+						}

+

+						if err := os.MkdirAll(propRoot, 0755); err != nil {

+							logrus.Errorf("failed to create PropagatedMount directory at %s: %v", propRoot, err)

+						}

 						// TODO: sanitize PropagatedMount and prevent breakout

 						p.PropagatedMount = filepath.Join(p.Rootfs, p.PluginObj.Config.PropagatedMount)

 						if err := os.MkdirAll(p.PropagatedMount, 0755); err != nil {

@@ -40,9 +40,20 @@ func (pm *Manager) enable(p *v2.Plugin, c *controller, force bool) error {

 	pm.cMap[p] = c

 	pm.mu.Unlock()

+	var propRoot string

 	if p.PropagatedMount != "" {

-		if err := mount.MakeRShared(p.PropagatedMount); err != nil {

-			return errors.WithStack(err)

+		propRoot = filepath.Join(filepath.Dir(p.Rootfs), "propagated-mount")

+

+		if err := os.MkdirAll(propRoot, 0755); err != nil {

+			logrus.Errorf("failed to create PropagatedMount directory at %s: %v", propRoot, err)

+		}

+

+		if err := mount.MakeRShared(propRoot); err != nil {

+			return errors.Wrap(err, "error setting up propagated mount dir")

+		}

+

+		if err := mount.Mount(propRoot, p.PropagatedMount, "none", "rbind"); err != nil {

+			return errors.Wrap(err, "error creating mount for propagated mount")

 		}

 	}

@@ -55,6 +66,9 @@ func (pm *Manager) enable(p *v2.Plugin, c *controller, force bool) error {

 			if err := mount.Unmount(p.PropagatedMount); err != nil {

 				logrus.Warnf("Could not unmount %s: %v", p.PropagatedMount, err)

 			}

+			if err := mount.Unmount(propRoot); err != nil {

+				logrus.Warnf("Could not unmount %s: %v", propRoot, err)

+			}

 		}

 		return errors.WithStack(err)

 	}