```mermaid
graph LR
classDef process fill:#E5F6FF,stroke:#73A6FF,stroke-width:2px
OverlayFs([OverlayFs]):::process
OverlayInode([OverlayInode]):::process
RealInode([RealInode]):::process
RealHandle([RealHandle]):::process
HandleData([HandleData]):::process
InodeStore([InodeStore]):::process
Config([Config]):::process
PassthroughFs([PassthroughFs]):::process
OverlayFs -->|including| Config
OverlayFs -->|includes multiple| lower_layers(PassthroughFs)
OverlayFs -->|includes one| upper_layer(PassthroughFs)
OverlayFs -->|manages| InodeStore
OverlayFs -->|manages| handles(HandleData)
OverlayInode -->|includes multiple| RealInode
OverlayInode -->|parent| OverlayInode
OverlayInode -->|child| OverlayInode
RealInode -->|associated with| PassthroughFs
RealHandle -->|associated with| PassthroughFs
HandleData -->|includes| OverlayInode
HandleData -->|includes| RealHandle
OverlayFs -->|operations involve| OverlayInode
InodeStore -->|stores| OverlayInode
```