Re: [PATCH] kdevt-diff

[Linus Torvalds]

On Mon, 14 Apr 2003, Roman Zippel wrote:
> 
> > But at the same time, for backwards compatibility clearly they have to
> > show up in the _old_ places too. Which really implies that there needs to
> > be a mapping function for the old numbers into the proper block device
> > queues etc, so that people can still use the old /dev nodes when they
> > upgrade their kernel.
> 
> Why should the kernel care about this?

Because a kernel that cannot be used with old filesystems is a _useless_ 
kernel as far as I'm concerned.

Backwards compatibility is _important_. It's HUGELY important. It's just
possibly more important than anything else the kernel ever can do.

And new kernels need to be able to seamlessly boot into a disk-image that 
may still need to be used from an old kernel. Without any magic going on.

We can discontinue the old IDE/SCSI majors one or two stable releases 
_after_ we've switched over to a global "disk major". In other words, 
that's about five years down the line after you shouldnä't have to care 
any more.

		Linus