driver: add pre09 migration logic

client/allocdir/task_dir_linux.go

@@ -0,0 +1,36 @@
+package allocdir
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+
+	multierror "github.com/hashicorp/go-multierror"
+)
+
+// unmountSpecialDirs unmounts the dev and proc file system from the chroot. No
+// error is returned if the directories do not exist or have already been
+// unmounted.
+func (t *TaskDir) unmountSpecialDirs() error {
+	errs := new(multierror.Error)
+	dev := filepath.Join(t.Dir, "dev")
+	if pathExists(dev) {
+		if err := unlinkDir(dev); err != nil {
+			errs = multierror.Append(errs, fmt.Errorf("Failed to unmount dev %q: %v", dev, err))
+		} else if err := os.RemoveAll(dev); err != nil {
+			errs = multierror.Append(errs, fmt.Errorf("Failed to delete dev directory %q: %v", dev, err))
+		}
+	}
+
+	// Unmount proc.
+	proc := filepath.Join(t.Dir, "proc")
+	if pathExists(proc) {
+		if err := unlinkDir(proc); err != nil {
+			errs = multierror.Append(errs, fmt.Errorf("Failed to unmount proc %q: %v", proc, err))
+		} else if err := os.RemoveAll(proc); err != nil {
+			errs = multierror.Append(errs, fmt.Errorf("Failed to delete proc directory %q: %v", dev, err))
+		}
+	}
+
+	return errs.ErrorOrNil()
+}