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=-13.5 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_MUTT autolearn=unavailable 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 9E2E8C64EB4 for ; Fri, 30 Nov 2018 19:56:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6539F2082F for ; Fri, 30 Nov 2018 19:56:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=osandov-com.20150623.gappssmtp.com header.i=@osandov-com.20150623.gappssmtp.com header.b="jYUNXSIV" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6539F2082F Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=osandov.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-block-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726809AbeLAHGd (ORCPT ); Sat, 1 Dec 2018 02:06:33 -0500 Received: from mail-pf1-f193.google.com ([209.85.210.193]:39562 "EHLO mail-pf1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726779AbeLAHGc (ORCPT ); Sat, 1 Dec 2018 02:06:32 -0500 Received: by mail-pf1-f193.google.com with SMTP id c72so3309307pfc.6 for ; Fri, 30 Nov 2018 11:56:09 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=osandov-com.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=lDemUPEMWm+oRHcUjNq0mhWEwrrriN+plSLSXai9Pwg=; b=jYUNXSIVnlKz7M8TAXjqIDWejbvySOYSRFbOWE0XjR57tAwFDRMM5YRj5ZhajyF/Yo oujR/g4XKNNpESh7iagA49ZrwGLB3rbBa5H1od/26BZ528tlfR0XjQSLGvHsGCpQBpgh SBytB4LV+DojW2BhP7pFG30o1EOQ4BbLbXNwGe10wOa+1R2DC4w0QTrPefdVP6aDZsRp t7aSph2A0n1hxtYygmmI7VXPudtLsX1I/ovgpICLfo4Oz+YgAis/cuwTzTkSpQFtZovV qGUulOaT7r3Zmx9WNVrmOCM9cP9IN7KxlRZeXF7E7eR9vXHw5ycIPLgdYJHyeWIrpkDV eodg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=lDemUPEMWm+oRHcUjNq0mhWEwrrriN+plSLSXai9Pwg=; b=UmZO4AWA/gMTeL+p8LzOUY3TjkeWpwTvk6EHS4AvtHSe74LOopaq+YPGzq47GVb3sK E1hpTHWDWpHp5NrT+NNEngUT2LyIDtIXmJ6jj47EtNKCktTnwWPVj90gnhXXPfpFtZni vc+58wUIc0wysCqSu+raoIAMStg62ueMdbkCxPywciAy85e9zOXZ5L6vT31OKhes4bjC iixdufjXp2V1erVR/Wmi1DaNVjrKr3w+5Z3oVcbgd6g2yF9BJiqGThOKv6cdt23Ie922 jiVJoCftbwidn2QallVezufsO/xLXcG9SXo/eFlqCPu0b22H17cn//yWfxskwLko9EWm Ax9g== X-Gm-Message-State: AA+aEWbGWCtCbdc0fc9/zue9c2fFRZ0iFpra1LhK6kCLuXR+HlssJtDq d8DF9d98rdQNPQrpBbmeS6MISQ== X-Google-Smtp-Source: AFSGD/UmDD2/WxEITstarAA613azDA8uRm8LDmfJmn9NHKjHYVUJmPY3QgQOIyCL3bDAB74jZjiP2g== X-Received: by 2002:a62:5182:: with SMTP id f124mr6947172pfb.238.1543607769002; Fri, 30 Nov 2018 11:56:09 -0800 (PST) Received: from vader ([2620:10d:c090:200::4:705d]) by smtp.gmail.com with ESMTPSA id i73sm12321942pfi.66.2018.11.30.11.56.08 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Fri, 30 Nov 2018 11:56:08 -0800 (PST) Date: Fri, 30 Nov 2018 11:56:07 -0800 From: Omar Sandoval To: Huijin Park Cc: Andreas Dilger , Michael Callahan , Omar Sandoval , js07.lee@samsung.com, Huijin Park , linux-block@vger.kernel.org, linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH,1/2] genhd: avoid overflow of sectors in disk_stats Message-ID: <20181130195607.GA27411@vader> References: <1543570361-3168-1-git-send-email-huijin.park@samsung.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1543570361-3168-1-git-send-email-huijin.park@samsung.com> User-Agent: Mutt/1.11.0 (2018-11-25) Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Fri, Nov 30, 2018 at 04:32:40AM -0500, Huijin Park wrote: > From: "huijin.park" > > This patch changes the 'sectors' type to an u64. > In 32 bit system, the 'sectors' can accumulate up to about 2TiB. > If a 32 bit system makes i/o over 2TiB while running, > the 'sectors' will overflow. > As a result, the part_stat_read(sectors), the diskstats in proc and > the (lifetime|session)_write_kbytes in sysfs return invalid statistic. What about parsers which expect it to be an unsigned long? E.g., iostat: https://github.com/sysstat/sysstat/blob/v12.1.1/rd_stats.c#L736 At least with glibc, scanf seems to truncate sanely, but this appears to be undefined. > Signed-off-by: huijin.park > --- > block/genhd.c | 6 +++--- > include/linux/genhd.h | 2 +- > 2 files changed, 4 insertions(+), 4 deletions(-) > > diff --git a/block/genhd.c b/block/genhd.c > index 0145bcb..7518dcd 100644 > --- a/block/genhd.c > +++ b/block/genhd.c > @@ -1343,10 +1343,10 @@ static int diskstats_show(struct seq_file *seqf, void *v) > part_stat_unlock(); > part_in_flight(gp->queue, hd, inflight); > seq_printf(seqf, "%4d %7d %s " > - "%lu %lu %lu %u " > - "%lu %lu %lu %u " > + "%lu %lu %llu %u " > + "%lu %lu %llu %u " > "%u %u %u " > - "%lu %lu %lu %u\n", > + "%lu %lu %llu %u\n", > MAJOR(part_devt(hd)), MINOR(part_devt(hd)), > disk_name(gp, hd->partno, buf), > part_stat_read(hd, ios[STAT_READ]), > diff --git a/include/linux/genhd.h b/include/linux/genhd.h > index 0c5ee17..5bf86f9 100644 > --- a/include/linux/genhd.h > +++ b/include/linux/genhd.h > @@ -84,7 +84,7 @@ struct partition { > > struct disk_stats { > u64 nsecs[NR_STAT_GROUPS]; > - unsigned long sectors[NR_STAT_GROUPS]; > + u64 sectors[NR_STAT_GROUPS]; > unsigned long ios[NR_STAT_GROUPS]; > unsigned long merges[NR_STAT_GROUPS]; > unsigned long io_ticks; > -- > 1.7.9.5 >