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.