[plugins] return err when failing remove

Fixes a case where removing the plugin from disk would
fail silently. Also moves pluginStore remove after we
remove from disk, so 'docker plugin ls' doesn't isn't
empty in case it errors out.

Signed-off-by: Christopher Jones <tophj@linux.vnet.ibm.com>

plugin/backend_linux.go

@@ -5,7 +5,6 @@ package plugin
 import (
 	"bytes"
 	"encoding/json"
-	"errors"
 	"fmt"
 	"io"
 	"io/ioutil"
@@ -23,6 +22,7 @@ import (
 	"github.com/docker/docker/plugin/distribution"
 	"github.com/docker/docker/plugin/v2"
 	"github.com/docker/docker/reference"
+	"github.com/pkg/errors"
 	"golang.org/x/net/context"
 )
 
@@ -268,7 +268,7 @@ func (pm *Manager) Push(name string, metaHeader http.Header, authConfig *types.A
 }
 
 // Remove deletes plugin's root directory.
-func (pm *Manager) Remove(name string, config *types.PluginRmConfig) error {
+func (pm *Manager) Remove(name string, config *types.PluginRmConfig) (err error) {
 	p, err := pm.pluginStore.GetByName(name)
 	pm.mu.RLock()
 	c := pm.cMap[p]
@@ -294,12 +294,18 @@ func (pm *Manager) Remove(name string, config *types.PluginRmConfig) error {
 	}
 
 	id := p.GetID()
-	pm.pluginStore.Remove(p)
 	pluginDir := filepath.Join(pm.libRoot, id)
-	if err := os.RemoveAll(pluginDir); err != nil {
-		logrus.Warnf("unable to remove %q from plugin remove: %v", pluginDir, err)
+
+	defer func() {
+		if err == nil || config.ForceRemove {
+			pm.pluginStore.Remove(p)
+			pm.pluginEventLogger(id, name, "remove")
+		}
+	}()
+
+	if err = os.RemoveAll(pluginDir); err != nil {
+		return errors.Wrap(err, "failed to remove plugin directory")
 	}
-	pm.pluginEventLogger(id, name, "remove")
 	return nil
 }