DISCUSSION: /dev/fd%d.%d and /dev/{a}cd%d[ac] to be discontinued ?

I am committing a BURN_BRIDGES patch which puts the density select
devices of the floppy driver and the 'a' and 'c' compat partitions of
the CD drivers on the chopping block for 6-current.

There is no loss of functionality from this, the fdcontrol(8) utility
allows even greater flexibility than the density select devices do
for floppies and the 'a' and 'c' compat parititons can be simulated
with symlinks from userland should any critical application be found
to have hardcoded paths.

The use of device cloning functions in disk drivers under GEOM is
not as such impossible, but it would be quite complicated and I
would rather avoid it unless we have much better killer apps for
it than these two uses.


As soon as these uses of cloning code has been removed, I will move
the floppy and CD drivers under GEOM, paving the way for the
significant changes to the buf/VM system which some of you have
already heard rumours about.  (more will emerge after BSDcon'03)

And now comes the bit which I would like to offer for discussion:

Should we do this for 5.2 instead ?

By pulling this into 5.2, the divergence between 5-stable and
6-current can be managed much better, and we will be able to backport
much more from 6-current to 5-stable than we would be able to
otherwise.

If we do not do this I fear that it will be close to impossible to
MFC filesystem work in practice.

And let me repeat:  the only loss of functionality is the density
select devices for floppy disks which will have to be done with the
fdcontrol(8) utility instead.

-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
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