From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762691AbcALPDF (ORCPT ); Tue, 12 Jan 2016 10:03:05 -0500 Received: from g1t5425.austin.hp.com ([15.216.225.55]:36973 "EHLO g1t5425.austin.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750802AbcALPDD (ORCPT ); Tue, 12 Jan 2016 10:03:03 -0500 Message-ID: <1452610938.19330.66.camel@hpe.com> Subject: Re: [PATCH] BTT: Change nd_btt_arena_is_valid() to verify UUID From: Toshi Kani To: Dan Williams Cc: Vishal Verma , "linux-kernel@vger.kernel.org" , micah.parrish@hpe.com, "linux-nvdimm@lists.01.org" Date: Tue, 12 Jan 2016 08:02:18 -0700 In-Reply-To: References: <1450393200-6802-1-git-send-email-toshi.kani@hpe.com> <1450427687.11503.14.camel@kernel.org> <1450451737.20148.121.camel@hpe.com> <1450464730.10450.14.camel@hpe.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.16.5 (3.16.5-3.fc22) Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2015-12-18 at 14:23 -0800, Dan Williams wrote: > On Fri, Dec 18, 2015 at 10:52 AM, Toshi Kani wrote: > > On Fri, 2015-12-18 at 09:54 -0800, Dan Williams wrote: > > > On Fri, Dec 18, 2015 at 7:15 AM, Toshi Kani > > > wrote: > > > > On Fri, 2015-12-18 at 01:34 -0700, Vishal Verma wrote: > > > > > Also, I wonder if this problem is solved by using libndctl to > > > > > manage > > > > > BTTs. > > > > > > > > I have not tested with libndctl yet, but I think our bind/unbind > > > > scripts do the same procedures. > > > > > > We loop through all combinations of sector size in our unit test. If > > > you want to change the sector size the expectation is that the > > > namespace is destroyed and fully re-created, especially due to the > > > fact that changing sector size invalidates all data on the namespace. > > > > > > See: https://github.com/pmem/ndctl/blob/master/lib/test-libndctl.c > > > > The parent_uuid is not set on our NVDIMM-N systems. I do not see > > 'uuid' file under sysfs 'namespaceX.X' per namespace_visible(), either. > > This concept of creating/destroying a namespace is a bit foreign to us > > since we've never needed to do. Can you elaborate how it's supposed to > > work for NVDIMM-N? > > > > Ugh, yes. An oversight on my part, let me give this some thought. > Whatever we decide, I want the libndctl api to be identical for the > two cases. > > I expect the simplest option is to have > ndctl_namespace_disable_invalidate() destroy the btt-info block in the > NVDIMM-N case. Do you have any update on this? If we are going to use ndctl to address this issue, does it mean that we will have to use ndctl to manage BTT? Thanks, -Toshi