From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id F2F66C1B0F2 for ; Wed, 20 Jun 2018 10:53:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B67D420846 for ; Wed, 20 Jun 2018 10:53:41 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B67D420846 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753995AbeFTKxj (ORCPT ); Wed, 20 Jun 2018 06:53:39 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:52002 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752787AbeFTKxi (ORCPT ); Wed, 20 Jun 2018 06:53:38 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 753D740214E2; Wed, 20 Jun 2018 10:53:37 +0000 (UTC) Received: from warthog.procyon.org.uk (ovpn-120-94.rdu2.redhat.com [10.10.120.94]) by smtp.corp.redhat.com (Postfix) with ESMTP id A07CF7C25; Wed, 20 Jun 2018 10:53:36 +0000 (UTC) Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 From: David Howells In-Reply-To: <20180620074647.4152617-1-arnd@arndb.de> References: <20180620074647.4152617-1-arnd@arndb.de> To: Arnd Bergmann Cc: dhowells@redhat.com, y2038@lists.linaro.org, Anna Schumaker , linux-afs@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] afs: use a consistent interpretation of time values MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <5319.1529492016.1@warthog.procyon.org.uk> Date: Wed, 20 Jun 2018 11:53:36 +0100 Message-ID: <5320.1529492016@warthog.procyon.org.uk> X-Scanned-By: MIMEDefang 2.79 on 10.11.54.5 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.7]); Wed, 20 Jun 2018 10:53:37 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.7]); Wed, 20 Jun 2018 10:53:37 +0000 (UTC) for IP:'10.11.54.5' DOMAIN:'int-mx05.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'dhowells@redhat.com' RCPT:'' Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Arnd Bergmann wrote: > which avoids the y2038 overflow No it doesn't. The AFS protocol is limited. > + time64_t mtime_client; /* last time client changed data */ > + time64_t mtime_server; /* last time server changed data */ > ... > - time_t creation; /* volume creation time */ > + time64_t creation; /* volume creation time */ Unless you can change the AFS protocol, this is a waste of memory. It might be better to change them to u32 as they are protocol values rather than system values. > - inode->i_ctime.tv_sec = get_seconds(); > - inode->i_ctime.tv_nsec = 0; > - inode->i_atime = inode->i_mtime = inode->i_ctime; > + inode->i_ctime = inode->i_atime = inode->i_mtime = current_time(inode); Surely, the tv_nsec should be zero since anything else cannot be represented in the AFS protocol. I will grant, however, I should be consistently using them as unsigned values. Note that the answers to the above may change if and when I start supporting the YFS protocol extensions, but for the AFS protocol, this is simply not there. David