Re: PATCH - change to blkdev->queue calling triggers BUG in md.c

On Tue, 3 Sep 2002 Andries.Brouwer@cwi.nl wrote:

Why?
Because in some cases it is undesirable.

Again, Why?

You can always use the flat device as-is. 

Because in some cases it crashes the kernel.

But moving it to user space would cause the kernel to crash anyway. Bugs 
are bugs.

Because it involves guessing and heuristics.

The same guesses and heuristics would have to be in user space. 

Because policy belongs in user space.

It's not policy. It's a fact of life that disks need to be split up into 
parts, and the partitioning schemes are well-defined and shared across 
multiple operating systems.

Yes - that is my main point: doing it on demand. On demand only.

But I actually _agree_ with this. 

However, that has nothing to do with whether it is in user space or kernel 
space. In many ways it is _easier_ to do on demand in kernel space: when 
somebody opens /dev/sda1 and it isn't partitioned yet, you know it needs 
to be. 

The fact that partitioning right now is to some degree handled by device
drivers is a problem, but that's not a user space vs kernel space issue.
It's slowly getting moved to higher levels.

		Linus