What happened to the patch for module reference counting when using dma-buf API

[Volker Vogelhuber]

I just stumbled across the same problem the patch from Tomasz 
Stanislawski (https://lkml.org/lkml/2012/8/8/163) would solve over two 
years ago. But it seems like it hasn't been merged into mainline. Why 
not? Is there any other possibility to avoid modules being released 
while other modules still use dma buffers of that module?

regards,
    Volker