Re: [patch 4/5] vfs: per superblock dentry stats

[Jan Blunck <jblunck@suse.de>]

On Mon, May 29, David Chinner wrote:

> > -struct dentry_stat_t {
> > +struct dentry_stat {
> >  	int nr_dentry;
> >  	int nr_unused;
> > -	int age_limit;          /* age in seconds */
> > -	int want_pages;         /* pages requested by system */
> > -	int dummy[2];
> > +	int age_limit;		/* age in seconds */
> >  };
> 
> that changes the size of the structure from 6*sizeof(int) to
> 3*sizeof(int)....
> 
> > Index: work-2.6/kernel/sysctl.c
> > ===================================================================
> > --- work-2.6.orig/kernel/sysctl.c
> > +++ work-2.6/kernel/sysctl.c
> > @@ -958,7 +958,7 @@ static ctl_table fs_table[] = {
> >  	{
> >  		.ctl_name	= FS_DENTRY,
> >  		.procname	= "dentry-state",
> > -		.data		= &dentry_stat,
> > +		.data		= &global_dentry_stat,
> >  		.maxlen		= 6*sizeof(int),
> 
> With the above change, maxlen = 3*sizeof(int).
> 
> Given that's a userspace visible change, should the above structure
> change use a "int dummy[3];" to keep the global structure and userspace
> export the same?

Hmm, probably you are right. I'll change this.

Jan