allow holder to close/open/close without panic on closing closed channel

holder.go

@@ -101,6 +101,9 @@ func NewHolder() *Holder {
 
 // Open initializes the root data directory for the holder.
 func (h *Holder) Open() error {
+	// Reset closing in case Holder is being reopened.
+	h.closing = make(chan struct{})
+
 	h.setFileLimit()
 
 	h.Logger.Printf("open holder path: %s", h.Path)
@@ -178,6 +181,9 @@ func (h *Holder) Close() error {
 		}
 	}
 
+	// Reset opened in case Holder needs to be reopened.
+	h.opened = make(chan struct{})
+
 	return nil
 }
 

holder_internal_test.go

@@ -287,3 +287,13 @@ func TestHolderCleaner_CleanHolder(t *testing.T) {
 		}
 	}
 }
+
+// Ensure holder can reopen.
+func TestHolderCleaner_Reopen(t *testing.T) {
+	h := NewHolder()
+	h.Path = "path"
+	h.Open()
+	h.Close()
+	h.Open()
+	h.Close()
+}