Re: [PATCH] new system call mknod64

On Mon, Apr 21, 2003 at 07:47:49PM +0100, Christoph Hellwig wrote:
> 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.

Why?  Whenever we deal with fs code, we _do_ map anyway (bytesex, if nothing
else).  Ditto for any network filesystems.

Let's go for 32:32 internal and simply map upon mknod(2) and friends.
On the syscall boundary.  End of problem.