Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932158AbWAYWAz (ORCPT ); Wed, 25 Jan 2006 17:00:55 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751123AbWAYWAz (ORCPT ); Wed, 25 Jan 2006 17:00:55 -0500 Received: from ebiederm.dsl.xmission.com ([166.70.28.69]:46763 "EHLO ebiederm.dsl.xmission.com") by vger.kernel.org with ESMTP id S1751177AbWAYWAy (ORCPT ); Wed, 25 Jan 2006 17:00:54 -0500 To: Trond Myklebust Cc: Arjan van de Ven , Alan Cox , Hubertus Franke , Dave Hansen , Greg KH , "Serge E. Hallyn" , linux-kernel@vger.kernel.org, Cedric Le Goater Subject: Re: RFC [patch 13/34] PID Virtualization Define new task_pid api References: <20060117143258.150807000@sergelap> <20060117155600.GF20632@sergelap.austin.ibm.com> <1137513818.14135.23.camel@localhost.localdomain> <1137518714.5526.8.camel@localhost.localdomain> <20060118045518.GB7292@kroah.com> <1137601395.7850.9.camel@localhost.localdomain> <43D14578.6060801@watson.ibm.com> <43D52592.8080709@watson.ibm.com> <1138050684.24808.29.camel@localhost.localdomain> <1138062125.24808.47.camel@localhost.localdomain> <1138137060.14675.73.camel@localhost.localdomain> <1138137305.2977.92.camel@laptopd505.fenrus.org> <1138201811.8720.9.camel@lade.trondhjem.org> <1138217416.8718.10.camel@lade.trondhjem.org> From: ebiederm@xmission.com (Eric W. Biederman) Date: Wed, 25 Jan 2006 14:59:50 -0700 In-Reply-To: <1138217416.8718.10.camel@lade.trondhjem.org> (Trond Myklebust's message of "Wed, 25 Jan 2006 14:30:16 -0500") Message-ID: User-Agent: Gnus/5.1007 (Gnus v5.10.7) Emacs/21.4 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1379 Lines: 38 Trond Myklebust writes: > On Wed, 2006-01-25 at 11:01 -0700, Eric W. Biederman wrote: >> fs/nfs/nfs3proc.c:nfs3_proc_create() >> For O_EXCL we have arg.verifier = current->pid. > > Yes, but that does not result in any permanent state that would be tied > to the pid on the server. The verifier here is used only to ensure > idempotency of the exclusive create RPC call. > >> fs/lockd/clntproc.c:nlmclnt_setlockargs() >> We have: lock->oh.len = sprintf(req->a_owner, "%d@%s", >> current->pid, system_utsname.nodename); >> >> I think this is the fcntl() case. >> I would suggest fl_pid might have something to do with it >> but that is part flock based locking. > > That name is not interpreted by the NLM server. It is, AFAIK, only used > for debugging purposes. Ok I though it might have been compared to equality someplace. > nlm_find_lockowner() is used to define a unique identifier that is > supposed to be sent to the server as the 'pid'. Ok interesting. All I know for certain was that with 2 pidspaces using the same nfs mount I was confusing something, with regards to locking. Eric - 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/