Re: kernel/params.c: 'err' variable "set but not used" and perhaps should be?

[Rusty Russell <rusty@rustcorp.com.au>]

Tejun Heo <htejun@gmail.com> writes:
>> > @@ -853,7 +853,8 @@ static void __init version_sysfs_builtin(void)
>> >                mk = locate_module_kobject(vattr->module_name);
>> >                if (mk) {
>> > -                       err = sysfs_create_file(&mk->kobj, &vattr->mattr.attr);
>> > +                       if (sysfs_create_file(&mk->kobj, &vattr->mattr.attr))
>> > +                               doesnt_happen();
>> >                        kobject_uevent(&mk->kobj, KOBJ_ADD);
>> >                        kobject_put(&mk->kobj);
>> >                }
>> 
>> Arguably then, the BUG_ON macro seems more appropriate for this situation
>> than this suggested doesnt_happen macro or my original offering of a call to
>> pr_warning.
>
> It does happen.  If you don't wanna roll back on failure, just wrap it
> in WARN_ON() so that there's at least some indication that something
> failed there?  It'd kinda suck to be missing some interface files w/o
> any indication, wouldn't it?

Please describe the circumstances under which this function can fail.

Thanks,
Rusty.