Re: [PATCH 2/2] Replace pid_t in autofs with struct pid reference

[ebiederm@xmission.com (Eric W. Biederman)]

"Serge E. Hallyn" <serue@us.ibm.com> writes:

>> >  void autofs4_dentry_release(struct dentry *);
>> >  extern void autofs4_kill_sb(struct super_block *);
>> > diff --git a/fs/autofs4/waitq.c b/fs/autofs4/waitq.c
>> > index 9857543..4a9ad9b 100644
>> > --- a/fs/autofs4/waitq.c
>> > +++ b/fs/autofs4/waitq.c
>> > @@ -141,8 +141,8 @@ static void autofs4_notify_daemon(struct
>> >  		packet->ino = wq->ino;
>> >  		packet->uid = wq->uid;
>> >  		packet->gid = wq->gid;
>> > -		packet->pid = wq->pid;
>> > -		packet->tgid = wq->tgid;
>> > +		packet->pid = pid_nr(wq->pid);
>> > +		packet->tgid = pid_nr(wq->tgid);
>> >  		break;
>> 
>> I'm assuming we build the packet in the process context of the
>> daemon we are sending it to.  If not we have a problem here.
>
> Yes this is data being sent to a userspace daemon (Ian pls correct me if
> I'm wrong) so the pid_nr is the only thing we can send.

Agreed.  The question is are we in the user space daemon's process when
we generate the pid_nr.  Or do we stuff this in some kind of socket,
and the socket switch locations of the packet.

Basically I'm just trying to be certain we are calling pid_nr in the
proper context.  Otherwise we could get the wrong pid when we have
multiple pid namespaces in play.

Eric