Add OnForget to FsNode interface.

fuse/api.go

@@ -28,10 +28,13 @@ type FsNode interface {
 	Inode() *Inode
 	SetInode(node *Inode)
 	
+	// RmChild and AddChild run inside the critical section for
+	// the mutex behind Inode().LockTree().
 	RmChild(name string, child FsNode)
 	AddChild(name string, child FsNode)
 
 	Lookup(name string) (fi *os.FileInfo, node FsNode, code Status)
+	OnForget()
 	
 	// Misc.
 	Access(mode uint32, context *Context) (code Status)

fuse/defaultnode.go

@@ -40,6 +40,9 @@ func (me *DefaultFsNode) Inode() *Inode {
 	return me.inode
 }
 
+func (me *DefaultFsNode) OnForget() {
+}
+
 func (me *DefaultFsNode) RmChild(name string, child FsNode) {
 }
 

fuse/fsconnector.go

@@ -139,6 +139,7 @@ func (me *FileSystemConnector) considerDropInode(n *Inode) (drop bool) {
 		if ch == nil {
 			panic(fmt.Sprintf("trying to del child %q, but not present", k))
 		}
+		ch.fsInode.OnForget()
 		me.inodeMap.Forget(ch.nodeId)
 	}