On Tue, Mar 25, 2008 at 01:37:03PM -0400, Mark Lord wrote:

H. Peter Anvin wrote:

quoted

Mark Lord wrote:

quoted

Yeah, that would be just as good, really.  Maybe even better.

Mark Lord wrote (later on):

quoted

Instead, software has to search everything inside /sys/block/
looking for a "dev" file whose contents match,
rather than just trying to access something like this:

  /sys/block/8:1/start
or
  /sys/block/majors/8/minors/1/start

Or any one of a number of similar ways to arrange it. 

..

It shouldn't be under /sys/block... there are enough many things that scan 
/sys/block and assume any directory underneath it has the current format.

..

So long as we only add things, and not remove them, then any software
that scans /sys/block/ shouldn't care, really.

But yes, it could go elsewhere, too.
Perhaps a /sys/dev/ directory, populated with symbolic links
(or hard links?) back to the /sys/block/ entries, something like this:

  /sys/dev/block/8:0 -> ../../../block/sda
  /sys/dev/block/8:1 -> ../../../block/sda/sda1
  /sys/dev/block/8:2 -> ../../../block/sda/sda2
  ...

That's just a suggestion, really.
And what about character devices?

Perhaps Greg will chime in.

I've been waiting to see if sanity will take hold of anyone here.

Come on people, adding symlinks for device major:minor numbers in sysfs
to save a few 10s of lines of userspace code?  Can things get sillier?

You can add a single udev rule to probably build these in a tree in /dev
if you really need such a thing...

And what's wrong with your new ioctl recomendation?

greg k-h