Date: Tue, 27 Dec 2011 06:36:42 +0200 From: Maxim Ignatenko <gelraen.ua@gmail.com> To: Doug Barton <dougb@freebsd.org> Cc: freebsd-rc@freebsd.org Subject: Re: conf/163508: [rc.subr] [patch] Add " enable" and " disable" commands to rc.subr Message-ID: <CABWTX-Z8g7Tom8dJSH2Q=Hq38qy=WFdhtwzmSeoLe=jig9Mzaw@mail.gmail.com> In-Reply-To: <4EF90CE7.7050008@FreeBSD.org> References: <201112241230.pBOCUF3h064098@freefall.freebsd.org> <D9E8E12B-7E7F-4164-802F-4F6FE7DFB397@bsdimp.com> <4EF64915.4030006@FreeBSD.org> <DE3E9178-9610-4014-AABA-32C66823C1B8@bsdimp.com> <4EF8105D.3030907@FreeBSD.org> <CABWTX-Z9aPJpwdjOz6ZXRykGpDC0sJW0wpSAwr=pZpnL1Qwm6g@mail.gmail.com> <4EF90CE7.7050008@FreeBSD.org>
next in thread | previous in thread | raw e-mail | index | archive | help
On 27 December 2011 02:10, Doug Barton <dougb@freebsd.org> wrote:
> On 12/26/2011 09:26, Maxim Ignatenko wrote:
>> On 26 December 2011 08:12, Doug Barton <dougb@freebsd.org> wrote:
>>> On 12/24/2011 15:08, Warner Losh wrote:
>>>>
>>>> On Dec 24, 2011, at 2:50 PM, Doug Barton wrote:
>>>>
>>>>> On 12/24/2011 08:46, Warner Losh wrote:
>>>>>> Also, let's not reject =C2=A0it before it is done. =C2=A0Let's rejec=
t it
>>>>>> when it actually doesn't handle the cases that are interesting.
>>>>>> No sense in cutting off a good feature because of some
>>>>>> theoretical problem. =C2=A0It is a problem we have sometimes in the
>>>>>> project...
>>>>>
>>>>> Warner,
>>>>>
>>>>> You seemed to have missed the bit where I said, "We've already been
>>>>> down this path once before, and it turns out to be way harder to do
>>>>> this right than it looks at first glance."
>>>>
>>>> No, I get that totally. =C2=A0I just don't care. =C2=A0The fact that o=
thers
>>>> have failed shouldn't mean we should discourage others from trying.
>>>> We shouldn't be shooting arrows at people before they are given a
>>>> chance to produce something good or bad, or when they do shooting
>>>> them without evaluating their work.
>>>
>>> You do get that the OP included a patch, right?
>>>
>>>>> Just as an example of potential problems, imagine a scenario where
>>>>> the user has foo_enable=3DNO in rc.conf, but the service keeps
>>>>> starting up anyway.
>>>>
>>>> Most people call that a bug, or at least POLA. =C2=A0The few cases in =
the
>>>> tree where bar_enable=3Dyes forces foo_enable=3Dyes can be dealt with.
>>>
>>> No, you seem to be missing my point. Because of the way that rc.d
>>> processes the various *conf* options the last match "wins." So let's sa=
y
>>> that you had foo_enable=3D0 in /etc/rc.conf; but one of the conf files
>>> that's processed later has foo_enable=3D1. If that's the last match, it
>>> gets started. This is one of the many concerns regarding trying to
>>> automatically enable or disable things.
>>>
>>
>> Proposed patch searches all files (except /etc/defaults/rc.conf) that
>> are included by load_rc_config() in _reverse_ order, so even if there
>> are some other files included in rc.conf,
>
> It's unusual, but not impossible for files to actually be included in
> /etc/rc.conf. What I think you're referring to is the files included by
> rc.d.
>
>> foo_enable=3DNO gets added to
>> the end of last processed file and we still have foo enabled.
>
> I reviewed your patch, I understand how it works. I still think you're
> missing my concern. Imagine this scenario:
>
> 1. foo gets enabled by something (a port, whatever).
> 2. User notices that foo is enabled, doesn't understand why, and adds
> "foo_enable=3Dno" to /etc/rc.conf.
> 3. Because foo_enable=3Dyes is in a conf file other than /etc/rc.conf,
> which is included later, it gets started again on next reboot.
By default, there are only 2 files included after /etc/rc.conf:
/etc/rc.conf.local and /etc/rc.conf.d/${name}. Or you meant some other
files included manually (from where?)?
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?CABWTX-Z8g7Tom8dJSH2Q=Hq38qy=WFdhtwzmSeoLe=jig9Mzaw>