Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755746AbZCBSf5 (ORCPT ); Mon, 2 Mar 2009 13:35:57 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751060AbZCBSfs (ORCPT ); Mon, 2 Mar 2009 13:35:48 -0500 Received: from e37.co.us.ibm.com ([32.97.110.158]:38726 "EHLO e37.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750837AbZCBSfs (ORCPT ); Mon, 2 Mar 2009 13:35:48 -0500 Date: Mon, 2 Mar 2009 12:35:22 -0600 From: "Serge E. Hallyn" To: Dave Hansen Cc: containers , "linux-kernel@vger.kernel.org" , hch@infradead.org, Nathan Lynch , Ingo Molnar , Alexey Dobriyan Subject: Re: [RFC][PATCH 8/8] check files for checkpointability Message-ID: <20090302183522.GA13447@us.ibm.com> References: <20090227203425.F3B51176@kernel> <20090227203435.98735E54@kernel> <20090302133754.GA8033@us.ibm.com> <20090302095917.6cfeda55@thinkcentre.lan> <1236011251.26788.450.camel@nimitz> <20090302112247.76bb3662@thinkcentre.lan> <1236015052.26788.471.camel@nimitz> <20090302174433.GA12708@us.ibm.com> <1236017600.26788.488.camel@nimitz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1236017600.26788.488.camel@nimitz> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1323 Lines: 47 Quoting Dave Hansen (dave@linux.vnet.ibm.com): > On Mon, 2009-03-02 at 11:44 -0600, Serge E. Hallyn wrote: > > Quoting Dave Hansen (dave@linux.vnet.ibm.com): > > > On Mon, 2009-03-02 at 11:22 -0600, Nathan Lynch wrote: > > > > No.. I mean what if a process 1234 does > > > > > > > > f = fopen("/proc/1234/stat", "r"); > > > > > > > > and is then checkpointed. Can that path be resolved during restart, > > > > before pid 1234 is alive? > > > > > > Heh, that's a good one. > > > > > > It does mean that we can't do restore like this: > > > > > > for_each_cr_task() > > > restore_task_struct() > > > restore_files() > > > ... > > > > > > We have to do: > > > > > > for_each_cr_task() > > > restore_task_struct() > > > for_each_cr_task() > > > restore_files() > > > > > Which is what we actually do, right? > > OK, I have a really evil one. > > What if task 1234 does: > > open(O_RDONLY, "/proc/5678/fdinfo/44"); > > and task 5678 does: > > open(O_RDONLY, "/proc/5678/fdinfo/55"); Nice one. Let's make fdinfo files uncheckpointable for now :) -serge -- 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/