From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.saout.de ([127.0.0.1]) by localhost (mail.saout.de [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id S4frW6uXx2QS for ; Fri, 1 Jun 2012 07:55:26 +0200 (CEST) Received: from v4.tansi.org (ns.km33513-03.keymachine.de [87.118.94.3]) by mail.saout.de (Postfix) with ESMTP for ; Fri, 1 Jun 2012 07:55:25 +0200 (CEST) Received: from gatewagner.dyndns.org (84-74-162-209.dclient.hispeed.ch [84.74.162.209]) by v4.tansi.org (Postfix) with ESMTPA id 150A3205CD5 for ; Fri, 1 Jun 2012 07:55:25 +0200 (CEST) Date: Fri, 1 Jun 2012 07:55:24 +0200 From: Arno Wagner Message-ID: <20120601055524.GA27280@tansi.org> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Subject: Re: [dm-crypt] inconsistency in opening multiple mappers on the same device List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: dm-crypt@saout.de Of course you cannot have two mappings on the same name. The collision is not for the mapping, but for the name! How would you even address a mapping if you had several on the same /dev/mapper/<...> entry? That would be like having several different files under the same file name. Arno On Thu, May 31, 2012 at 06:12:02PM -0400, .. ink .. wrote: > I read the announcement of 1.4.3 and decided to do a simple test on > opening multiple mappers on the same device and this is what i found > out: > > test using cryptsetup 1.4.3 > > [root@mtz ink]# echo -n xxx | cryptsetup create zzz xxx > [root@mtz ink]# echo -n xxx | cryptsetup create zzz xxx > Device zzz already exists. > [root@mtz ink]# echo -n xxx | cryptsetup create yyy xxx > > [root@mtz ink]# ls -l /dev/mapper/ > total 0 > crw------- 1 root root 10, 236 May 29 14:46 control > lrwxrwxrwx 1 root root 7 May 31 18:01 yyy -> ../dm-1 > lrwxrwxrwx 1 root root 7 May 31 18:01 zzz -> ../dm-0 > > [root@mtz ink]# zuluCrypt-cli -P -d /dev/mapper/zzz > /home/ink/xxx > [root@mtz ink]# zuluCrypt-cli -P -d /dev/mapper/yyy > /home/ink/xxx > [root@mtz ink]# > > It looks like by default, cryptsetup does not allow opening more than > one mapper on the same device bu it only checks the mapper name, not > the device behind the mapper and hence it allows opening of multiple > mappers on the same device as long as they use a different mapper > name. > > The same behavior is there in luks based volume > > Also,shouldnt the error say mapper name since the check is on the > mapper,not the device behind the mapper. > _______________________________________________ > dm-crypt mailing list > dm-crypt@saout.de > http://www.saout.de/mailman/listinfo/dm-crypt > -- Arno Wagner, Dr. sc. techn., Dipl. Inform., CISSP -- Email: arno@wagner.name GnuPG: ID: 1E25338F FP: 0C30 5782 9D93 F785 E79C 0296 797F 6B50 1E25 338F ---- One of the painful things about our time is that those who feel certainty are stupid, and those with any imagination and understanding are filled with doubt and indecision. -- Bertrand Russell