svn commit: r216823 - head/sbin/shutdown

[Warner Losh]

On 01/01/2011 07:57, Jilles Tjoelker wrote:
> On Fri, Dec 31, 2010 at 02:57:17PM -0700, Warner Losh wrote:
>> On 12/31/2010 07:43, Jilles Tjoelker wrote:
>>> On Thu, Dec 30, 2010 at 06:06:31PM +0000, Pawel Jakub Dawidek wrote:
>>>> Author: pjd
>>>> Date: Thu Dec 30 18:06:31 2010
>>>> New Revision: 216823
>>>> URL: http://svn.freebsd.org/changeset/base/216823
>>>> Log:
>>>>     For compatibility with Linux and Solaris add poweroff(8).
>>>>     It is implemented as a hard link to shutdown(8) and it is equivalent of:
>>>>     	# shutdown -p now
>>> If we go that way, then for consistency reboot(8) and halt(8) should
>>> also be equivalent to calling shutdown -r now and shutdown -h now
>>> respectively, unless conflicting options are given. Linux has a -f
>>> option for what's currently reboot's and halt's default action, and
>>> fastboot(8)/fasthalt(8) could also retain the current behaviour.
>>> I would be in favour of this change.
>> I'm not sure I'd go this far.  I really *LIKE* that halt/reboot is the
>> low-level interface that shutdown -r now calls.  I'm not sure that
>> moving away from this would be a good idea.  It cuts out many levels of
>> indirection that can be useful in many instances.
> But that's not how it works. After printing all the warnings,
> shutdown(8) signals init. Ctrl+Alt+Del also signals init (and that's
> nontrivial to change, because it's in the kernel).
>
> Only if the strange -o option is used does shutdown execute reboot(8) or
> halt(8).
>
> I think the canonical low-level interface should be sending signals to
> init. reboot(8) and halt(8) doing things on their own should be banished
> to non-default options. (Something should be fixed first so that
> /etc/rc.d/mixer doesn't destroy the user's settings from single-user
> mode.)

I still strongly disagree with this change, however, the proper place to 
talk about it is on arch at .  reboot and halt purposely stop init, kill 
everything and call reboot.  That's what I mean that they are a 
lower-level interface than shutdown, which signals init to do its more 
complicated, higher level thing asyncrhonously in the background...

Warner