Return-Path: <linux-kernel-owner+willy=40w.ods.org@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id <S318334AbSHKT5J>; Sun, 11 Aug 2002 15:57:09 -0400
Received: (majordomo@vger.kernel.org) by vger.kernel.org
	id <S318338AbSHKT5J>; Sun, 11 Aug 2002 15:57:09 -0400
Received: from pc-62-30-255-50-az.blueyonder.co.uk ([62.30.255.50]:39372 "EHLO
	kushida.apsleyroad.org") by vger.kernel.org with ESMTP
	id <S318334AbSHKT5J>; Sun, 11 Aug 2002 15:57:09 -0400
Date: Sun, 11 Aug 2002 20:58:47 +0100
From: Jamie Lokier <lk@tantalophile.demon.co.uk>
To: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Linus Torvalds <torvalds@transmeta.com>,
       Paul Larson <plars@austin.ibm.com>,
       Hubertus Franke <frankeh@us.ibm.com>,
       Rik van Riel <riel@conectiva.com.br>, Andries Brouwer <aebr@win.tue.nl>,
       Andrew Morton <akpm@zip.com.au>, andrea@suse.de,
       Dave Jones <davej@suse.de>, lkml <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] Linux-2.5 fix/improve get_pid()
Message-ID: <20020811205847.A3206@kushida.apsleyroad.org>
References: <20020810182317.A306@kushida.apsleyroad.org> <Pine.LNX.4.44.0208101132490.2197-100000@home.transmeta.com> <20020810194813.D306@kushida.apsleyroad.org> <1029098474.16236.58.camel@irongate.swansea.linux.org.uk>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
User-Agent: Mutt/1.2.5.1i
In-Reply-To: <1029098474.16236.58.camel@irongate.swansea.linux.org.uk>; from alan@lxorguk.ukuu.org.uk on Sun, Aug 11, 2002 at 09:41:14PM +0100
Sender: linux-kernel-owner@vger.kernel.org
X-Mailing-List: linux-kernel@vger.kernel.org
Content-Length: 800
Lines: 20

Alan Cox wrote:
> If they hold both handles open and stat them and find the same inode
> number then yes its a bug. We have lots of room for inode numbers to
> handle 2^30 processes and allow for 2^30 other files

So, in general, the way to detect hard links requires both objects to be
open at the same time?  I was sure it was enough to stat(), and check
(st1.st_ino == st2.st_ino && st1.st_dev == st2.st_dev).

Admittedly, one of the object could be renamed or deleted in that time
so it's not 100% reliable on changing filesystems.

Ah well.

-- Jamie
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/