Re: [PATCH] print_dev_t for 2.6.0-test1-mm

Andries Brouwer
2003-07-16T23:30:53Z

On Wed, Jul 16, 2003 at 03:21:43PM -0700, Andrew Morton wrote:

> > > Why do we need the 16:16 option?
> >
> > It is not very important, but major 0 is reserved, so if userspace
> > (or a filesystem) hands us a 32-bit device number, we have to
> > split that in some way, not 0+32. Life is easiest with 16+16.
> > (Now the major is nonzero, otherwise we had 8+8.)
> > Other choices lead to slightly more complicated code.
> >
>
> Why would anyone hand the kernel a 32-bit device number? They're either 16
> or 64, are they not?

The kernel has no control over what userspace comes with.
And here userspace includes filesystems.
Not all filesystems know how to come with 64 bits.

Andries