From patchwork Wed Mar 13 10:17:04 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrea Righi X-Patchwork-Id: 10850887 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id BB4E31669 for ; Wed, 13 Mar 2019 10:17:09 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A60EF27BA5 for ; Wed, 13 Mar 2019 10:17:09 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 9A1FF2873A; Wed, 13 Mar 2019 10:17:09 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 226B027BA5 for ; Wed, 13 Mar 2019 10:17:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726435AbfCMKRI (ORCPT ); Wed, 13 Mar 2019 06:17:08 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:37981 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725893AbfCMKRH (ORCPT ); Wed, 13 Mar 2019 06:17:07 -0400 Received: from mail-wr1-f72.google.com ([209.85.221.72]) by youngberry.canonical.com with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.76) (envelope-from ) id 1h40wc-00056V-MB for linux-btrfs@vger.kernel.org; Wed, 13 Mar 2019 10:17:06 +0000 Received: by mail-wr1-f72.google.com with SMTP id n15so677149wrr.2 for ; Wed, 13 Mar 2019 03:17:06 -0700 (PDT) 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:mime-version :content-disposition:user-agent; bh=gtgImAkOnibGwd2zSzHyi7rA7YpC32VupyrC3qtJjFo=; b=dZKHpeqHU2V3t/RESgchqFAXA+rYv6kuDTPgayXmXDfX92pE7f3fqmSfiyN+EZi7jq MQYeL2ZC1wIuL5cjqicSRX8wPdwQTP3EbnptFTKFfjHYICDQ+yKpSQy8n6r65/jyKI9F HJScOyF2VlF370ocj+IClYEYrAJ3qccKfr7FPnxpAkskwVb9gzXZ9DuaSoK/yMAZRNP9 OlZGXtELRm/AoN3AdVPSd+z/w3GlBerPXNueXEkdjE/0uvOKm9A9/xbHTIlkAiyFSQPP B5Rg5UObvmtrZMnTDUimemmP5nA/ccDQLUEUnoYydn1edW2EaTunMxgCIwLvkKzczw78 ARWQ== X-Gm-Message-State: APjAAAWyGvBSxE680CpB5PUjwsTUTE0vjvDlYK8YCFRIRuDcfbHOxB/q lNtaBD7RGNWTVsOO4WZCXUV/10ZgXjmRA7IGFmAJz0DCBgIa1Y7H2z7BaqutuZF1/6Coy+EgJ0d W0LOP/NoBZxFYxKoFLyP9k39buZoC9bALjhRLSXIA X-Received: by 2002:adf:ea04:: with SMTP id q4mr629652wrm.97.1552472226372; Wed, 13 Mar 2019 03:17:06 -0700 (PDT) X-Google-Smtp-Source: APXvYqxRAhCNdvLfNwc4P4YZDUFkSesdlUiW9Qodvog6+7PyNZn+cDqIOxa8DrTdnNbHGdz5gZy5QA== X-Received: by 2002:adf:ea04:: with SMTP id q4mr629633wrm.97.1552472226098; Wed, 13 Mar 2019 03:17:06 -0700 (PDT) Received: from localhost (host82-131-dynamic.21-87-r.retail.telecomitalia.it. [87.21.131.82]) by smtp.gmail.com with ESMTPSA id t69sm2071235wmt.16.2019.03.13.03.17.04 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Wed, 13 Mar 2019 03:17:05 -0700 (PDT) Date: Wed, 13 Mar 2019 11:17:04 +0100 From: Andrea Righi To: Chris Mason , Josef Bacik , David Sterba Cc: linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] btrfs: raid56: properly unmap parity page in finish_parity_scrub() Message-ID: <20190313101703.GA9155@xps-13> MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Parity page is incorrectly unmapped in finish_parity_scrub(), triggering a reference counter bug on i386, i.e.: [ 157.662401] kernel BUG at mm/highmem.c:349! [ 157.666725] invalid opcode: 0000 [#1] SMP PTI Steps to reproduce the bug: - create a raid5 btrfs filesystem: # mkfs.btrfs -m raid5 -d raid5 /dev/sdb /dev/sdc /dev/sdd /dev/sde - mount it: # mount /dev/sdb /mnt - run btrfs scrub in a loop: # while :; do btrfs scrub start -BR /mnt; done BugLink: https://bugs.launchpad.net/bugs/1812845 Signed-off-by: Andrea Righi Reviewed-by: Johannes Thumshirn --- fs/btrfs/raid56.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/btrfs/raid56.c b/fs/btrfs/raid56.c index 1869ba8e5981..67a6f7d47402 100644 --- a/fs/btrfs/raid56.c +++ b/fs/btrfs/raid56.c @@ -2430,8 +2430,9 @@ static noinline void finish_parity_scrub(struct btrfs_raid_bio *rbio, bitmap_clear(rbio->dbitmap, pagenr, 1); kunmap(p); - for (stripe = 0; stripe < rbio->real_stripes; stripe++) + for (stripe = 0; stripe < nr_data; stripe++) kunmap(page_in_rbio(rbio, stripe, pagenr, 0)); + kunmap(p_page); } __free_page(p_page);