> > > as VOP_RENAME() is not intended to support cross-mount renames; any call 
> > > that ever did that would be an error.
> > 
> > i'm not sure if or not our VOP i/f is intended to support cross-mount ops.
> > (yes, i'm one of confused "future programmers". :-)
> 
> It's not supposed to, as I see no way our file system implementations 
> could cope.

they can cope with it by just passing vnodes to someone else
as nullfs does.  at least, layer_bypass() seems to allow it explicitly.
i hardly see benefits of such weird operations, though.

YAMAMOTO Takashi