Re: [PATCH 2/2] fix file counting

[Dipankar Sarma <dipankar@in.ibm.com>]

On Sat, Feb 18, 2006 at 01:45:29AM -0800, Andrew Morton wrote:
> Dipankar Sarma <dipankar@in.ibm.com> wrote:
> >
> > 
> >  Slight optimization -
> > 
> >  	if (get_nr_files() >= files_stat.max_files) {
> >  		if (capable(CAP_SYS_ADMIN)) {
> >  		/*
> >  		 * percpu_counters are inaccurate.  Do an expensive check before
> >  		 * we go and fail.
> >  		 */
> >  			if (percpu_counter_sum(&nr_files) >= 
> >  						files_stat.max_files)
> >  				goto over;
> >  		} else 
> >  			goto over;
> >  	}
> 
> That changes the behaviour for root.  Maybe you meant !capable(), but that
> still changes the behaviour.  I'm all confused.

Hmm.. on second thoughts, there is no harm doing the expensive check
for both priviledged and non-priviledged user. It will correctly
allow non-priviledged users to create the new file provided
the fast-path percpu counter value returned was greater than the 
slow path per-cpu counter value.

Just ignore my comment in the previous mail.

Thanks
Dipankar