From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from newverein.lst.de (verein.lst.de [213.95.11.211]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 9A62421A08D84 for ; Thu, 25 May 2017 06:00:29 -0700 (PDT) Date: Thu, 25 May 2017 15:00:27 +0200 From: Christoph Hellwig Subject: Re: [PATCH 10/23] afs: switch to use uuid_t and uuid_gen Message-ID: <20170525130027.GA30194@lst.de> References: <20170518062705.25902-1-hch@lst.de> <20170518062705.25902-11-hch@lst.de> <1495478957.6967.69.camel@linux.intel.com> <20170523084956.GB20121@lst.de> <1495545099.6967.81.camel@linux.intel.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1495545099.6967.81.camel@linux.intel.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: linux-nvdimm-bounces@lists.01.org Sender: "Linux-nvdimm" To: Andy Shevchenko Cc: linux-xfs@vger.kernel.org, linux-raid@vger.kernel.org, linux-nvdimm@lists.01.org, Mimi Zohar , Amir Goldstein , linux-kernel@vger.kernel.org, Steven Whitehouse , David Howells , linux-fsdevel@vger.kernel.org, Shaohua Li , Christoph Hellwig List-ID: On Tue, May 23, 2017 at 04:11:39PM +0300, Andy Shevchenko wrote: > Since we introduced a union it's possible that we might access the > member which wasn't last modified one. So, my comment is to give an > attention on such possibility and avoid if there is an aliasing > happened. We do for AFS (and XFS for fs fsid). My preference would be to not have the v1 struct defintion but instead provide a few helpers in uuid.h that use get_unaligned_be* if needed: uuid_v1_time_low() uuid_v1_time_mid() uuid_v1_time_time_hi_and_version().. >>From his previously reply it seems like Dave doesn't like that idea too much, in which case I suspect moving struct uuid_v1 back into afs and living with cast in it is the way to go. _______________________________________________ Linux-nvdimm mailing list Linux-nvdimm@lists.01.org https://lists.01.org/mailman/listinfo/linux-nvdimm From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: Re: [PATCH 10/23] afs: switch to use uuid_t and uuid_gen Date: Thu, 25 May 2017 15:00:27 +0200 Message-ID: <20170525130027.GA30194@lst.de> References: <20170518062705.25902-1-hch@lst.de> <20170518062705.25902-11-hch@lst.de> <1495478957.6967.69.camel@linux.intel.com> <20170523084956.GB20121@lst.de> <1495545099.6967.81.camel@linux.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <1495545099.6967.81.camel-VuQAYsv1563Yd54FQh9/CA@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linux-nvdimm-bounces-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org Sender: "Linux-nvdimm" To: Andy Shevchenko Cc: linux-xfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-raid-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-nvdimm-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org, Mimi Zohar , Amir Goldstein , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Steven Whitehouse , David Howells , linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Shaohua Li , Christoph Hellwig List-Id: linux-raid.ids On Tue, May 23, 2017 at 04:11:39PM +0300, Andy Shevchenko wrote: > Since we introduced a union it's possible that we might access the > member which wasn't last modified one. So, my comment is to give an > attention on such possibility and avoid if there is an aliasing > happened. We do for AFS (and XFS for fs fsid). My preference would be to not have the v1 struct defintion but instead provide a few helpers in uuid.h that use get_unaligned_be* if needed: uuid_v1_time_low() uuid_v1_time_mid() uuid_v1_time_time_hi_and_version().. >From his previously reply it seems like Dave doesn't like that idea too much, in which case I suspect moving struct uuid_v1 back into afs and living with cast in it is the way to go. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from verein.lst.de ([213.95.11.211]:37217 "EHLO newverein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965793AbdEYNA3 (ORCPT ); Thu, 25 May 2017 09:00:29 -0400 Date: Thu, 25 May 2017 15:00:27 +0200 From: Christoph Hellwig Subject: Re: [PATCH 10/23] afs: switch to use uuid_t and uuid_gen Message-ID: <20170525130027.GA30194@lst.de> References: <20170518062705.25902-1-hch@lst.de> <20170518062705.25902-11-hch@lst.de> <1495478957.6967.69.camel@linux.intel.com> <20170523084956.GB20121@lst.de> <1495545099.6967.81.camel@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1495545099.6967.81.camel@linux.intel.com> Sender: linux-xfs-owner@vger.kernel.org List-ID: List-Id: xfs To: Andy Shevchenko Cc: Christoph Hellwig , Amir Goldstein , linux-fsdevel@vger.kernel.org, Shaohua Li , Dan Williams , David Howells , Steven Whitehouse , Mimi Zohar , linux-xfs@vger.kernel.org, linux-raid@vger.kernel.org, linux-nvdimm@lists.01.org, linux-kernel@vger.kernel.org On Tue, May 23, 2017 at 04:11:39PM +0300, Andy Shevchenko wrote: > Since we introduced a union it's possible that we might access the > member which wasn't last modified one. So, my comment is to give an > attention on such possibility and avoid if there is an aliasing > happened. We do for AFS (and XFS for fs fsid). My preference would be to not have the v1 struct defintion but instead provide a few helpers in uuid.h that use get_unaligned_be* if needed: uuid_v1_time_low() uuid_v1_time_mid() uuid_v1_time_time_hi_and_version().. >>From his previously reply it seems like Dave doesn't like that idea too much, in which case I suspect moving struct uuid_v1 back into afs and living with cast in it is the way to go. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1424040AbdEYNAd (ORCPT ); Thu, 25 May 2017 09:00:33 -0400 Received: from verein.lst.de ([213.95.11.211]:37217 "EHLO newverein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965793AbdEYNA3 (ORCPT ); Thu, 25 May 2017 09:00:29 -0400 Date: Thu, 25 May 2017 15:00:27 +0200 From: Christoph Hellwig To: Andy Shevchenko Cc: Christoph Hellwig , Amir Goldstein , linux-fsdevel@vger.kernel.org, Shaohua Li , Dan Williams , David Howells , Steven Whitehouse , Mimi Zohar , linux-xfs@vger.kernel.org, linux-raid@vger.kernel.org, linux-nvdimm@ml01.01.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 10/23] afs: switch to use uuid_t and uuid_gen Message-ID: <20170525130027.GA30194@lst.de> References: <20170518062705.25902-1-hch@lst.de> <20170518062705.25902-11-hch@lst.de> <1495478957.6967.69.camel@linux.intel.com> <20170523084956.GB20121@lst.de> <1495545099.6967.81.camel@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1495545099.6967.81.camel@linux.intel.com> User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, May 23, 2017 at 04:11:39PM +0300, Andy Shevchenko wrote: > Since we introduced a union it's possible that we might access the > member which wasn't last modified one. So, my comment is to give an > attention on such possibility and avoid if there is an aliasing > happened. We do for AFS (and XFS for fs fsid). My preference would be to not have the v1 struct defintion but instead provide a few helpers in uuid.h that use get_unaligned_be* if needed: uuid_v1_time_low() uuid_v1_time_mid() uuid_v1_time_time_hi_and_version().. >>From his previously reply it seems like Dave doesn't like that idea too much, in which case I suspect moving struct uuid_v1 back into afs and living with cast in it is the way to go.