Re: [PATCH] new system call mknod64

Christoph Hellwig
2003-04-21T18:36:16Z

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.