[patch] halt/reboot/shutdown cleanup

[Warner Losh]

On May 14, 2012, at 3:25 AM, Doug Barton wrote:

> On 5/13/2012 3:42 PM, Warner Losh wrote:
>> 
>> On May 13, 2012, at 4:06 PM, Jilles Tjoelker wrote:
>>> Also, the normal forms of halt and reboot will now call shutdown
>>> so users get a clear message of the event.
>> 
>> I hate these messages, which is why I always use halt or reboot to
>> avoid them. 
> 
> You hate messages? Seriously?

Seriously.  And I'd appreciate it if you didn't mock me on this.  It is rude and insulting and not constructive to a dialog.

>> I find the additional delays from doing a shutdown -r to
>> also be annoying, which is why I never use them.
> 
> If things are working as they should be, running rc.shutdown won't cause
> any delays at all vs. the brute force method used by 'shutdown'. The
> only time you'll see a delay is if something that's being killed
> actually needs it to cleanly shut down.

halt and reboot are low level interfaces.  shutdown is the higher level interface that people should use.

>>> Halt and reboot still support the -q option to invoke reboot(2)
>>> without anything else. The -d and -n options now require -q
>>> (because init is signaled if -q is not used, and init will not do
>>> dump or nosync).
>>> 
>>> The -l option of halt and reboot now not only suppresses logging,
>>> but also user notification. It does this by signaling init directly
>>> and not going through shutdown.
>>> 
>>> The -o option of shutdown goes away because there does not seem
>>> any point in executing halt or reboot if they are going to send the
>>> same signal to init anyway.
>> 
>> Generally, I think this is a really bad idea, just like the last time
>> it was proposed.
> 
> This topic comes up very often as users are confused by the fact that we
> have 2 different methods for shutdown/reboot, and the ones that seem the
> most obvious (halt and reboot) are the most pathological.
> 
> IMO we should maintain the old behavior as binaries with scary names
> that the anachronists can use in local aliases, and we should modify
> halt and reboot in a manner similar to what Jilles is suggesting.

See my other post for a way forward, sans bogusly scary names.

Warner