Add stateCreated as default fd state

Added a new state for a freshly opened `fileDescriptor`.
In `flushUp` only bubble up update if state is either `stateDirty` or
`stateCreated`. `stateFlushed` should prevent bubble up.

fd.go

@@ -14,7 +14,8 @@ import (
 type state uint8
 
 const (
-	stateFlushed state = iota
+	stateCreated state = iota
+	stateFlushed
 	stateDirty
 	stateClosed
 )
@@ -153,7 +154,7 @@ func (fi *fileDescriptor) flushUp(fullSync bool) error {
 		fi.inode.node = nd
 		fi.inode.nodeLock.Unlock()
 		fallthrough
-	case stateFlushed:
+	case stateCreated:
 		if !fullSync {
 			return nil
 		}
@@ -169,6 +170,8 @@ func (fi *fileDescriptor) flushUp(fullSync bool) error {
 		}
 		fi.state = stateFlushed
 		return nil
+	case stateFlushed:
+		return nil
 	default:
 		panic("invalid state")
 	}

file.go

@@ -110,6 +110,7 @@ func (fi *File) Open(flags Flags) (_ FileDescriptor, _retErr error) {
 		inode: fi,
 		flags: flags,
 		mod:   dmod,
+		state: stateCreated,
 	}, nil
 }
 

root.go

@@ -68,6 +68,7 @@ const (
 // (Not to be confused with the `unixfs.FSNode`.)
 type FSNode interface {
 	GetNode() (ipld.Node, error)
+
 	Flush() error
 	Type() NodeType
 }