Re: [v6,1/2] pid: Replace pid bitmap implementation with IDR API

[Oleg Nesterov]

On 10/19, Andrei Vagin wrote:
>
> Hi Gargi,
>
> This patch breaks CRIU, because it changes a meaning of ns_last_pid.

...

> > @@ -311,7 +297,7 @@ static int pid_ns_ctl_handler(struct ctl_table *table, int write,
> >  	 * it should synchronize its usage with external means.
> >  	 */
> >  
> > -	tmp.data = &pid_ns->last_pid;
> > +	tmp.data = &pid_ns->idr.idr_next;

Ah, yes, off-by-one error...

Gargi, I don't think you need to make another version, I'd suggest you to send
the trivial fix to Andrew, afaics you just need to replace these 2 lines with

	unsigned int last;
	int err;

	tmp.data = &last;
	err = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
	if (!err)
		idr_set_cursor(&pid_ns->idr, last + 1);
	return err;

Oleg.