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=-9.6 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS 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 4D571C433DF for ; Thu, 20 Aug 2020 15:32:16 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 089D22075E for ; Thu, 20 Aug 2020 15:32:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="eEQiNAr7" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 089D22075E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 7C63F8D0024; Thu, 20 Aug 2020 11:32:15 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 7773D8D0001; Thu, 20 Aug 2020 11:32:15 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 63E0B8D0024; Thu, 20 Aug 2020 11:32:15 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0249.hostedemail.com [216.40.44.249]) by kanga.kvack.org (Postfix) with ESMTP id 45D018D0001 for ; Thu, 20 Aug 2020 11:32:15 -0400 (EDT) Received: from smtpin09.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id EA27B3638 for ; Thu, 20 Aug 2020 15:32:14 +0000 (UTC) X-FDA: 77171338188.09.cart30_4302fa627031 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin09.hostedemail.com (Postfix) with ESMTP id 310F7180AD817 for ; Thu, 20 Aug 2020 15:32:08 +0000 (UTC) X-HE-Tag: cart30_4302fa627031 X-Filterd-Recvd-Size: 5911 Received: from mail-ej1-f67.google.com (mail-ej1-f67.google.com [209.85.218.67]) by imf12.hostedemail.com (Postfix) with ESMTP for ; Thu, 20 Aug 2020 15:31:59 +0000 (UTC) Received: by mail-ej1-f67.google.com with SMTP id c16so2982158ejx.12 for ; Thu, 20 Aug 2020 08:31:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=msZh1S5NuZX02zho73S2OZYmPkkP6K5y19k9T2pRLlU=; b=eEQiNAr7rWImjK6RLknd81QWM9qtZqSYCjD9pFF78tYd4TULEoiAOd8XfONRjXELup E4CNQ1gh1sZl0QDdS6kR8HrKAHNfSD+4o0BLmZc4Rt5ObBJHIUcBPiiBhfYSHIsJQGEv GOK6LIqNuD/dnKlE0VEvbndrg3mORYdlPSWKgZRcW76Ucd2BJmf1B9QSmhwPCeMoMtM/ Yng6JQdTv/He2XKn2KdPtyGWPSehTDalQBD2wuBGTb92X89VDQShPYLtgU22ECsgcCb7 mfTETbXBT2BnlsJ7RTJUySNQnCAtIoC54fKjVRxTl/dkN9JeIok7CTmdO3W9KBDEKZkO bIoA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=msZh1S5NuZX02zho73S2OZYmPkkP6K5y19k9T2pRLlU=; b=SbW6rL58/yNy4ocrUmcO6kio+xpbT2AOM5ErzSK42gwNm+LUIMf8xY6pDl3NftpZQr 3t238zp+uzNxDMg1/GHPCGvTNKqTZVz7/S4TUqgHQHsaZYs6aRZnkOR/jwJarN4Oc93+ JmCMGfN9UpAW5mERa5UytszZOzQFTAM/P3OVINAAmD72vzB05W1+XBAyIZC11jdlR+Of 7V0iNc/JNbmkvb7ETrrvvBKijfFDMeHDY4Oj8oBm3Yr/WiS3SwQXoM1cWuH1+t5qHCCC RDeYAsx+LsGctjZN/+jrvyLTPZEnDsnh3vZUqLx3bKNRAS0GeURUaM05dqCKXXep0IUZ 36+A== X-Gm-Message-State: AOAM532sUooEWLvBkkNVnCuaNOurpae+fDnwXT69125IztqBgBEvf19U NESlDCH7SZMHj0A9ZvktNu2xOtkVeGiEMia7WIQ= X-Google-Smtp-Source: ABdhPJzD+zk0t+nWGD6xbgEYzbLJU9rJ448TkrySkRv6QD+kn8cqo7BHXH1FT90ym+QcSpF3F2Vrku7Pi7nKPbUArzU= X-Received: by 2002:a17:906:84e1:: with SMTP id zp1mr3535972ejb.499.1597937518785; Thu, 20 Aug 2020 08:31:58 -0700 (PDT) MIME-Version: 1.0 References: <20200820045323.7809-1-hsiangkao@redhat.com> In-Reply-To: <20200820045323.7809-1-hsiangkao@redhat.com> From: Yang Shi Date: Thu, 20 Aug 2020 08:31:46 -0700 Message-ID: Subject: Re: [PATCH v2] mm, THP, swap: fix allocating cluster for swapfile by mistake To: Gao Xiang Cc: Andrew Morton , Linux MM , Linux Kernel Mailing List , Carlos Maiolino , Eric Sandeen , "Huang, Ying" , Yang Shi , Rafael Aquini , Dave Chinner , stable Content-Type: text/plain; charset="UTF-8" X-Rspamd-Queue-Id: 310F7180AD817 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam02 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed, Aug 19, 2020 at 9:54 PM Gao Xiang wrote: > > SWP_FS is used to make swap_{read,write}page() go through > the filesystem, and it's only used for swap files over > NFS. So, !SWP_FS means non NFS for now, it could be either > file backed or device backed. Something similar goes with > legacy SWP_FILE. > > So in order to achieve the goal of the original patch, > SWP_BLKDEV should be used instead. > > FS corruption can be observed with SSD device + XFS + > fragmented swapfile due to CONFIG_THP_SWAP=y. > > I reproduced the issue with the following details: > > Environment: > QEMU + upstream kernel + buildroot + NVMe (2 GB) > > Kernel config: > CONFIG_BLK_DEV_NVME=y > CONFIG_THP_SWAP=y > > Some reproducable steps: > mkfs.xfs -f /dev/nvme0n1 > mkdir /tmp/mnt > mount /dev/nvme0n1 /tmp/mnt > bs="32k" > sz="1024m" # doesn't matter too much, I also tried 16m > xfs_io -f -c "pwrite -R -b $bs 0 $sz" -c "fdatasync" /tmp/mnt/sw > xfs_io -f -c "pwrite -R -b $bs 0 $sz" -c "fdatasync" /tmp/mnt/sw > xfs_io -f -c "pwrite -R -b $bs 0 $sz" -c "fdatasync" /tmp/mnt/sw > xfs_io -f -c "pwrite -F -S 0 -b $bs 0 $sz" -c "fdatasync" /tmp/mnt/sw > xfs_io -f -c "pwrite -R -b $bs 0 $sz" -c "fsync" /tmp/mnt/sw > > mkswap /tmp/mnt/sw > swapon /tmp/mnt/sw > > stress --vm 2 --vm-bytes 600M # doesn't matter too much as well > > Symptoms: > - FS corruption (e.g. checksum failure) > - memory corruption at: 0xd2808010 > - segfault > > Fixes: f0eea189e8e9 ("mm, THP, swap: Don't allocate huge cluster for file backed swap device") > Fixes: 38d8b4e6bdc8 ("mm, THP, swap: delay splitting THP during swap out") > Cc: "Huang, Ying" > Cc: Yang Shi > Cc: Rafael Aquini > Cc: Dave Chinner > Cc: stable > Signed-off-by: Gao Xiang > --- > v1: https://lore.kernel.org/r/20200819195613.24269-1-hsiangkao@redhat.com > > changes since v1: > - improve commit message description Thanks for incorporating this. Reviewed-by: Yang Shi > > Hi Andrew, > Kindly consider this one instead if no other concerns... > > Thanks, > Gao Xiang > > mm/swapfile.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/mm/swapfile.c b/mm/swapfile.c > index 6c26916e95fd..2937daf3ca02 100644 > --- a/mm/swapfile.c > +++ b/mm/swapfile.c > @@ -1074,7 +1074,7 @@ int get_swap_pages(int n_goal, swp_entry_t swp_entries[], int entry_size) > goto nextsi; > } > if (size == SWAPFILE_CLUSTER) { > - if (!(si->flags & SWP_FS)) > + if (si->flags & SWP_BLKDEV) > n_ret = swap_alloc_cluster(si, swp_entries); > } else > n_ret = scan_swap_map_slots(si, SWAP_HAS_CACHE, > -- > 2.18.1 > >