From: Rusty Russell <rusty@rustcorp.com.au>
To: Dmitry Torokhov <dtor@vmware.com>
Subject: Re: [PATCH 1/2] param: allow omitting set() methods for truly read-only params
Date: Wed, 11 Aug 2010 11:09:30 +0930
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        Len Brown <lenb@kernel.org>
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On Wed, 11 Aug 2010 04:28:44 am Dmitry Torokhov wrote:
> Certain "parameters", such as acpica version and upcoming VMware Balloon
> version, are need to be purely read-only. They are exported as
> parameters so that they are visible in sysfs even in cases when the
> module is built directly into the kernel, but their values should be
> immutable. Specifying S_IRUGO takes care of sysfs interface, but it
> has no effect on kernel command line or modprobe configuration files and
> so these "parameters" attempt to omit set() method. Unfortunately
> kernel expects set() to be always present and crashes if it is not
> there, so let's add appropriate check.
> 
> Signed-off-by: Dmitry Torokhov <dtor@vmware.com>

That almost makes sense, but not quite.

Your followup patch uses this for version, but the version is already
in /sys/module/vmware_balloon/version as is standard with modules, no?

Confused,
Rusty.
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