Re: [PATCH] new system call mknod64

[Christoph Hellwig]

On Mon, Apr 21, 2003 at 11:44:59AM -0700, Linus Torvalds wrote:
> We HAVE to do the mapping somewhere. Old applications only use the lower 
> 16 bits, and that's just something that MUST NOT be broken. 
> 
> The question is only _where_ (not whether) we do the mapping. Right now we 
> keep "dev_t" in teh same format as we give back to user space, and thus we 
> always map into that format internally. But we don't have to: we can have 
> an internal format that is different from the one we show users.

Why do we need to do a mapping?  Old applications just won't see the
high bits (they're mapped to whatever overflow value) - values that
fit into the old 16bit range should never be remapped.