[arch-projects] [initscripts][PATCH] arch-sysctl: suppress errors about unknown keys

[Seblu]

On Wed, Dec 14, 2011 at 1:23 AM, C Anthony Risinger <anthony at xtfx.me> wrote:
> On Tue, Dec 13, 2011 at 2:44 PM, lolilolicon <lolilolicon at gmail.com> wrote:
>> On Wed, Dec 14, 2011 at 3:48 AM, Tom Gundersen <teg at jklm.no> wrote:
>>> On Tue, Dec 13, 2011 at 8:09 PM, lolilolicon <lolilolicon at gmail.com> wrote:
>>>>
>>>> According to sysctl(8), the -e option is used to "ignore errors about
>>>> unknown keys", so no "other error" would be hidden by it.
>>>
>>> Many reasons for "unknown keys", maybe the module is no longer
>>> installed (by mistake), or it failed loading, or, ....
>>
>> But in case of those failures, one shouldn't expect to look for errors in
>> the sysctl error messages in the first place.  Those error messages should
>> be supplementary at best.
>>
>>>
>>>> It's a good thing if we can report error on misspelled keys, but only if
>>>> we don't report the same errors when the keys are just unknown due to
>>>> disabled modules.
>>>
>>> I can't imagine how that could be done...
>>>
>>>> Currently I have IPv6 disabled, so I get in boot
>>>> messages:
>>>>
>>>>    error: "net.ipv6.conf.all.use_tempaddr" is an unknown key
>>>>    error: "net.ipv6.conf.default.use_tempaddr" is an unknown key
>>>
>>> To me it makes most sense to disable the sysctl entries if you disable
>>> the modules, anything else should give errors.
>>
>> To me, the sysctl entries are to the modules what configuration files are
>> to e.g. daemons -- you don't comment/rename configs if you disable daemons
>> in rc.conf.
>>
>>>
>>>> Now if I consistently get these errors, it would be very likely for me to
>>>> ignore some other real errors, like misspelling:
>>>>
>>>>    error: "net.ipv9.conf.default.use_tempaddr" is an unknown key
>>>
>>> With your patch this error would be ignored anyway...
>>
>> Yes, but if in either case it will be ignored, better just not print it :P
>> My point is that if one gets used to the net.ipv6.* key errors, other real
>> errors would more likely be ignored; if instead, we suppress the
>> non-critical unknown key errors, the other real errors will stand out.
>>
>>>
>>>> BTW, pre arch-sysctl, it used to be `sysctl -q -p &>/dev/null`, which
>>>> really hides *all* errors;
>>>
>>> Yeah, we are slowly moving away from ignoring errors wherever we can.
>>
>> I can understand the intent.
>>
>>>
>>>>  in contrast, The -e option sounds far more
>>>> reasonable...
>>>
>>> Sure, but it still risks ignoring some real errors, which is worse
>>> than being annoying.
>>
>> I still think in reality -e is pretty safe; I wonder what the original
>> intent for the -e option.
>>
>> Well, I think I've made my points.  Comparing options, I would add the -e
>> to my copy of arch-sysctl, if unfortunately we couldn't agree on this
>> matter.
>
> i don't know how beneficial it is to worry about disabled daemons, or
> much else related to sysctl ... because imo the whole thing is
> busted/outdated, even sysctl.d as implemented by systemd.  in
> `/etc/rc.multi`, `arch-sysctl` is called *before* any daemons are
> started, so anything added to /proc after that will not be affected
> anyway (eg. any modules loaded by daemons et al).
>
> the sad truth is sysctl is not hot-plug friendly at all AFAIK, and
> only sysfs attributes (/sys) can be [cleanly] modified by udev rules
> ...
>
> i know this because i have a desire to disable bridge firewalling on
> many of my setups, a /proc/net entry, but the hierarchy doesn't exist
> until the bridge modules are loaded ... which, unless explicitly
> requested, will almost certainly happen after sysctl stuff has fired.

Yes, sysctl loading is not hotplug ready...

I am rather in the opinion of Tom, we do not have to hide errors.

Maybe your patch would be more friendly if you check if quiet
parameter is given during boot?


-- 
Sébastien Luttringer
www.seblu.net