Merge pull request #11349 from cpuguy83/11132_better_error_message_on_graph_init

Make errors from graphdriver friendlier
Upstream-commit: 88c706e442fb489387ba8ef5fd2de42479f74b87
Component: engine

components/engine/daemon/daemon.go

@@ -876,7 +876,7 @@ func NewDaemonFromDirectory(config *Config, eng *engine.Engine) (*Daemon, error)
 	// Load storage driver
 	driver, err := graphdriver.New(config.Root, config.GraphOptions)
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("error intializing graphdriver: %v", err)
 	}
 	log.Debugf("Using graph driver %s", driver)
 

components/engine/daemon/graphdriver/aufs/aufs.go

@@ -378,7 +378,7 @@ func (a *Driver) mount(id, mountLabel string) error {
 	}
 
 	if err := a.aufsMount(layers, rw, target, mountLabel); err != nil {
-		return err
+		return fmt.Errorf("error creating aufs mount to %s: %v", target, err)
 	}
 	return nil
 }

components/engine/daemon/graphdriver/overlay/overlay.go

@@ -301,7 +301,7 @@ func (d *Driver) Get(id string, mountLabel string) (string, error) {
 
 	opts := fmt.Sprintf("lowerdir=%s,upperdir=%s,workdir=%s", lowerDir, upperDir, workDir)
 	if err := syscall.Mount("overlay", mergedDir, "overlay", 0, label.FormatMountLabel(opts, mountLabel)); err != nil {
-		return "", err
+		return "", fmt.Errorf("error creating overlay mount to %s: %v", mergedDir, err)
 	}
 	mount.path = mergedDir
 	mount.mounted = true