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=-8.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,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 1EACCC43603 for ; Fri, 13 Dec 2019 21:10:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5DB5824682 for ; Fri, 13 Dec 2019 21:10:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725937AbfLMVKH (ORCPT ); Fri, 13 Dec 2019 16:10:07 -0500 Received: from mout.kundenserver.de ([212.227.126.130]:45929 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725747AbfLMVKH (ORCPT ); Fri, 13 Dec 2019 16:10:07 -0500 Received: from mail-qk1-f175.google.com ([209.85.222.175]) by mrelayeu.kundenserver.de (mreue010 [212.227.15.129]) with ESMTPSA (Nemesis) id 1Mnq4Q-1huvWZ2uao-00pJD5; Fri, 13 Dec 2019 22:10:05 +0100 Received: by mail-qk1-f175.google.com with SMTP id z14so360747qkg.9; Fri, 13 Dec 2019 13:10:05 -0800 (PST) X-Gm-Message-State: APjAAAWQQByzRJl+FRsh8mWKGC+1rCfdZACj1Xt9Dax7lDMM5PGgvkTp BRbPDqVVHLAzeXZFoIRpgFIJvJIrjqQJUvrTVY0= X-Google-Smtp-Source: APXvYqyzAwR27KFKi5TkucxKpQNzOtGX0NSY+WgXrxpmwySh3tOt3BeOLfaBKAthCSioGeE7zaSTXD2qo8rhZRMFjvA= X-Received: by 2002:a37:84a:: with SMTP id 71mr15047213qki.138.1576271404501; Fri, 13 Dec 2019 13:10:04 -0800 (PST) MIME-Version: 1.0 References: <20191213141046.1770441-1-arnd@arndb.de> <20191213141046.1770441-11-arnd@arndb.de> In-Reply-To: From: Arnd Bergmann Date: Fri, 13 Dec 2019 22:09:48 +0100 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH v2 10/12] nfsd: use boottime for lease expiry alculation To: Chuck Lever Cc: Bruce Fields , Linux NFS Mailing List , "linux-kernel@vger.kernel.org" , y2038 Mailman List Content-Type: text/plain; charset="UTF-8" X-Provags-ID: V03:K1:u4OHeFUmz3H/zb1xub1jtQBskNNTwVgzesEymRCHoYLFvufnxM2 gPTbFFhWO6l7/m0gG6WMPqIm9Z9V10keWMTyI6kUspm7+2laK9JwkeAI+77p9PmOh5PVAvE SjD0G/WeGITJ0cB3fSA1tTcSqKNaTBd9dqbJCjmecycb9lknHSEJ3VN6S7a4NRAkd3TpVjZ SQmLDHMDGqj6uAoMmemOQ== X-UI-Out-Filterresults: notjunk:1;V03:K0:dG+P425Wcyo=:9IxV4PrNZPQAgqwpS+PNZK Dv8uaSwx1wV8UXsB+/+Ji6Ha6jRNM4GpbiZG/xZX0k3KOf8mwSBMwupJOEC3+urHrPFO2HLGG iJjGkQLn2cEjNM7svNXGmSNSkIt+7VhYCDG8aBIZSD9v2GnqEj/Js7C10q6Zb5KTFuFAmJxF5 j8yNBODZWmWyXTct8O+E8aH4ek7IqcjrwEDNfuy14S6WUT7t6+R1iiIkf811fq5FLbO5ZjCdO GsssljDOsst+X8AAcMjcDUVbXBcvA66QsUYWZ5mmzbjeh/lO64tNOAfCwP4WClWD831Qp6uqs OB827wfffVJvYEQMgElECNP+3XpSEkXrlqp4bSs5ch1mXHvICOWSBw6q+09VVpVx+dsbTMOeL GrOTRYMeSOMv/o5C3Og8F/SQZUoIdxUWZWVKGAX4hv8Fo8shXJaN3j1KgyTta4tEkrdOQmdfJ l2bCKld3WBfAIbq1EDw3uHi2goLIQ8J0RLC6EQJh+JA6yKJlW/TD19E/+LVCBUJ5MjFWNJC80 myCU7OeIr+Ee8G47BFOcf9kQ8XDxf2GPE+LXZco9yH3IuPXFFVmbuY8Um7sYwvZZR/2d2/Bdf vFrFZs0t4qBlNZfep5ZyWdnuK4WWMOEXLgMOM2ILA50fbEKivENBUfZRnaZhcSeeIrXr0hInF QsOzSQXVG3QV4iEfvMx/6dol7rP5dHFAQuIBZUT/JqWVKhySbj7Il1+U+0wGnP7uvpcc9UnrZ gAHRnlDpyB9U7IzpD15ZZBLuf+JyYIpFUS2xyPnSw40EBif6ynyMAwpBNJg2kund90RExMUwA +ck2qANEIYRQeKZkYSOdc0bA0sn8HgLOY8TmeWld/7febOKTwkJM/Jj2xnv+g5HDtFS490tFd liEA1OCLh7z1cjhtWriw== Sender: linux-nfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org On Fri, Dec 13, 2019 at 7:23 PM Chuck Lever wrote: > > On Dec 13, 2019, at 11:40 AM, Arnd Bergmann wrote: > > > > On Fri, Dec 13, 2019 at 5:26 PM Chuck Lever wrote: > >>> On Dec 13, 2019, at 9:10 AM, Arnd Bergmann wrote: > > > >>> diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c > >>> index 24534db87e86..508d7c6c00b5 100644 > > > > With the old code, dividing by 10 was always fast as > > nn->nfsd4_lease was the size of an integer register. Now it > > is 64 bit wide, and I check that truncating it to 32 bit again > > is safe. > > OK. That comment should state this reason rather than just repeating > what the code does. ;-) I changed the comment now to: + /* + * nfsd4_lease is set to at most one hour in __nfsd4_write_time, + * so we can use 32-bit math on it. Warn if that assumption + * ever stops being true. + */ Modified branch pushed to git://git.kernel.org/pub/scm/linux/kernel/git/arnd/playground.git y2038-nfsd-v2 Arnd