>    in the case of mountroothook, i doubt it should have been
>    implemented as a hook in the first place.
> 
> 
> it was implemented to allow floppy boots to "do something" at
> mountroot time, such as eject the boot floppy and allow the
> root floppy to be mounted... is it used for other things now?

i don't think it's used for other things.

> what else would you prefer to see instead?

what mountroothook does is semantically equivalent to
a function pointer in struct device.
given the current usage of it, i think that even a flag
can be enough.

YAMAMOTO Takashi