From patchwork Wed Jun 20 08:31:10 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Arnd Bergmann X-Patchwork-Id: 139299 Delivered-To: patch@linaro.org Received: by 2002:a2e:970d:0:0:0:0:0 with SMTP id r13-v6csp534671lji; Wed, 20 Jun 2018 02:14:43 -0700 (PDT) X-Google-Smtp-Source: ADUXVKLMy2dZ4VUHM9jSWnkKxtXr4CFoN9XcolngQA+WsWm7waasn2fMF8OGuSQm43/VhnI4sL0F X-Received: by 2002:a17:902:8347:: with SMTP id z7-v6mr23208460pln.290.1529486083752; Wed, 20 Jun 2018 02:14:43 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1529486083; cv=none; d=google.com; s=arc-20160816; b=Ph9sZpdoNfnPrwrXUxRTOpiPCvJosLoRGmMY77NiJodKc87Y1jEDAjV1ox/kuJnmJi +7o++OSV+SUfA/oj3G64QylBEgefGoxKoKAlBy3Ve1Ox/0vW4Jmbt1kIenbjKmBuf9dM yiCzOrWTL4NwDUZX5arUoI+wm5ryqztD+9k1lZ0p9MllC/zWtuuS8qiopoQdEN5X0NqZ 2k9rP06XSuAGNSV3oO+k9L5zI4yhIws8qEJWJvsB9s4jI89iLzhEbqGPpPIGxDI4z+yj WKGiTV970JC9teYnF1UDyWAe4++kn35mYQHA06Hv6/scnAqEjf9zKQCM8ccl7qUKZeBr oPvw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:message-id:date:subject:cc:to:from :arc-authentication-results; bh=xhHGN6GU9dIaALOaCyEXrxU556a6mWALcNy72MNtUXM=; b=Y9K/sOidgi3AaG/M+/IZZDGmt+b8cxQNTXgPzIEE5M8b/WIXFKYFoZA6UrBDAxoO05 rkwsEt1gW3Tq3MhsQUhZrrGxXBRIioll0I5rirRc0WPRBQKQuSoxu4Dbdb4LIe7N7gXO 2l5BMUGpkEwJouFbTonTCFOpMZRC50xvPJEF6VPn/M07CLjPsRxHg9pRXUEog3NuseAS 2vXPCNzIVhsrAO9Ul6PukTOzYfWgghiFrgfqjBUETJCNxRKLLYYT9iv1hGYTdfojhHKQ XqtDyqUGM0KOmk+YA2RfEGfHF7thykw8ZXt/otrrUF4lOkeihfqiZOrbO89fiG8nlbXC rwHw== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id g14-v6si1965554plo.95.2018.06.20.02.14.43; Wed, 20 Jun 2018 02:14:43 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754827AbeFTJOk (ORCPT + 30 others); Wed, 20 Jun 2018 05:14:40 -0400 Received: from mout.kundenserver.de ([212.227.126.131]:44455 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754299AbeFTIdr (ORCPT ); Wed, 20 Jun 2018 04:33:47 -0400 Received: from wuerfel.lan ([95.208.111.237]) by mrelayeu.kundenserver.de (mreue005 [212.227.15.129]) with ESMTPA (Nemesis) id 0LrGGm-1gChuk1us0-0135sI; Wed, 20 Jun 2018 10:33:42 +0200 From: Arnd Bergmann To: David Howells Cc: y2038@lists.linaro.org, Arnd Bergmann , linux-cachefs@redhat.com, linux-kernel@vger.kernel.org Subject: [PATCH] cachefiles: avoid deprecated get_seconds() Date: Wed, 20 Jun 2018 10:31:10 +0200 Message-Id: <20180620083339.766780-1-arnd@arndb.de> X-Mailer: git-send-email 2.9.0 X-Provags-ID: V03:K1:5u9IqHPzy3OlmTSEzyeONOP86GAngA6lrWFV9i7lcKSXY2Edgx7 X/9UXKcQEMZP6Jy35BvMYKRsKGKDGj0560PJrHGvsO0H5OUBlNavWiQwCmM2t3wp9dQ7nWr XMrnKkShGcZXFJAw7nj6kByAYg+hk0Y+Eytw9Z0fhQPTtqhcdYfmXGWlRrNY3KusvXOz2bn gXIzB4kxsRjw+XORDD4gA== X-UI-Out-Filterresults: notjunk:1; V01:K0:cAuOoTufQ3I=:npO72s62Ui7Rz2uDl7mhS5 jmkkB2nJNG0jc1JtDprUsarxkQ69UVWrPhWgnNXzbBpNeaAPWoRlE7CqnlEo5nYVF522jzjEb emdoSbmM14lBkRB54xhVCesUorT33/kh5lONckrwxydLSpEPehBNJ25HxUxjHQli1nkTIiILB ztO6icLWx9+xDSbX+06LnNtTnsxnEPOawnajOXqYnkqI7rnrbpQ8bQnzf12t/VbH3HdAenYEV 2opUU+1ri7yD8CW+bGKKhJgIvPJ5NwMCSPgC/OZTyO1p7L1u+5gxADOKtAw1i9LCq+Kx/E9CI NC/qEoOH1MSQvBvjCZ+CJnUWibDj0KAUreC89eW1cO9uAl3q+4ih1EPWJdMq3E8My2U0uqPUI MJrrPwJmdjLQTuvxnjmnbz7FqhaqUAmdw5OOWrKgQ8KeHTwfrTMdKit1GU/qsUHoQAWuC2WmH WZrVdRbYjYmy9cakC0lFeOqUm3sZKrTwC9CuHZFOtF2tdTq1ecU5JH8ukzwQfUDciDjAL0eLW KMOM/9b82OSCTKdfJnemIpKUiYq9KfzPYmiRdF0SO0TeGUgB3ialtM/WgbHEQ+wYGCbCY82pE XAtUnjuQKV/5MGdbB84TTYWSGHmIMwaALmO4kvvCzBlPLcIMdxAp4Ds0qdfR4aYmDnkorLtdm XbXH/qPDKx1IPOBwNd1JD/aXD71lmkMJGH75WK+pG+vHY6iXChIBqMFMbpjwL2ioq77M= Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org get_seconds() returns an unsigned long can overflow on some architectures and is deprecated because of that. In cachefs, we cast that number to a a 32-bit integer, which will overflow in year 2106 on all architectures. The overflow probably isn't harmful in the end, since the timestamps are only used to make the file names unique, but they don't strictly have to be in monotonically increasing order. Moving to ktime_get_real_seconds() avoids the deprecated interface, the question is whether we should still truncate to 32 bits. In this patch, I decided to not overflow, but instead to extend the file names using the 64-bit timestamp, so they will be 17 characters after 2106 rather than 16. Signed-off-by: Arnd Bergmann --- fs/cachefiles/namei.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) -- 2.9.0 diff --git a/fs/cachefiles/namei.c b/fs/cachefiles/namei.c index ab0bbe93b398..5705e29d4506 100644 --- a/fs/cachefiles/namei.c +++ b/fs/cachefiles/namei.c @@ -297,7 +297,7 @@ static int cachefiles_bury_object(struct cachefiles_cache *cache, { struct dentry *grave, *trap; struct path path, path_to_graveyard; - char nbuffer[8 + 8 + 1]; + char nbuffer[16 + 8 + 1]; int ret; _enter(",'%pd','%pd'", dir, rep); @@ -336,8 +336,8 @@ static int cachefiles_bury_object(struct cachefiles_cache *cache, try_again: /* first step is to make up a grave dentry in the graveyard */ - sprintf(nbuffer, "%08x%08x", - (uint32_t) get_seconds(), + sprintf(nbuffer, "%08llx%08x", + (uint64_t) ktime_get_real_seconds(), (uint32_t) atomic_inc_return(&cache->gravecounter)); /* do the multiway lock magic */