[Lunar-commits] <moonbase> udev: Proper kernel configuration detection

[Zbigniew Luszpinski]

> Stefan Wold wrote:
> > commit 3177c3a652551e46ba70cc1124d043e88119e08e
> > Author: Stefan Wold <ratler at lunar-linux.org>
> > Date:   Thu Mar 25 07:35:31 2010 +0100
> > 
> >     udev: Proper kernel configuration detection
> > ---
> 
> I think this is wrong
> 
> > +if kernel_option_present CONFIG_SYSFS_DEPRECATED || \
> 
> why does having (more) deprecated sysfs files prevent udev from working? 
> that doesn't make sense, it just ADDS old nodes in sysfs, but doesn't 
> affect the non-deprecated ones.

CONFIG_SYSFS_DEPRECATED does not prevent udev from working AFAIR but can make you stop working when you encounter weird situation and will start to investigate the issue instead of doing planned job. The reason for blocking CONFIG_SYSFS_DEPRECATED is to keep Lunar running always inside supported code. This way we can better support the users and have less problems with support. Another reason is to avoid udev nag text with 15 secs pause at boot telling that SYSFS is deprecated and why it is important to turn it off.

Here is the more technical answer than mine more user oriented:
http://article.gmane.org/gmane.linux.hotplug.devel/13141
Pay attention to this part at the end of response:
"So it's not strictly a udev requirement, it's that system services
will increasingly depend on new features udev offers, which will fail
in in subtle ways with older kernels or the deprecated sysfs layout."
I do not like fixing and supporting subtle failures because they are usually subtle to find and fix :)

Do you have any problems (like LVM not booting) when CONFIG_SYSFS_DEPRECATED is turned off or just only wanted to know why?

have a nice day,
Zbigniew Luszpinski