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=-8.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 6E41BC388F9 for ; Fri, 30 Oct 2020 12:37:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1849722242 for ; Fri, 30 Oct 2020 12:37:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726434AbgJ3Mhn (ORCPT ); Fri, 30 Oct 2020 08:37:43 -0400 Received: from mgw-01.mpynet.fi ([82.197.21.90]:58598 "EHLO mgw-01.mpynet.fi" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725939AbgJ3Mhn (ORCPT ); Fri, 30 Oct 2020 08:37:43 -0400 X-Greylist: delayed 991 seconds by postgrey-1.27 at vger.kernel.org; Fri, 30 Oct 2020 08:37:42 EDT Received: from pps.filterd (mgw-01.mpynet.fi [127.0.0.1]) by mgw-01.mpynet.fi (8.16.0.42/8.16.0.42) with SMTP id 09UCBMOo060917; Fri, 30 Oct 2020 14:20:42 +0200 Received: from ex13.tuxera.com (ex13.tuxera.com [178.16.184.72]) by mgw-01.mpynet.fi with ESMTP id 34g4hx0uhv-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-SHA384 bits=256 verify=NOT); Fri, 30 Oct 2020 14:20:42 +0200 Received: from [192.168.108.50] (194.100.106.190) by tuxera-exch.ad.tuxera.com (10.20.48.11) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Fri, 30 Oct 2020 14:20:42 +0200 Subject: Re: [PATCH 1/4] erofs: fix setting up pcluster for temporary pages To: , Gao Xiang CC: Gao Xiang , , LKML References: <20201022145724.27284-1-hsiangkao.ref@aol.com> <20201022145724.27284-1-hsiangkao@aol.com> From: Vladimir Zapolskiy Message-ID: Date: Fri, 30 Oct 2020 14:20:31 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.5.0 MIME-Version: 1.0 In-Reply-To: <20201022145724.27284-1-hsiangkao@aol.com> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [194.100.106.190] X-ClientProxiedBy: tuxera-exch.ad.tuxera.com (10.20.48.11) To tuxera-exch.ad.tuxera.com (10.20.48.11) X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.312,18.0.737 definitions=2020-10-30_04:2020-10-30,2020-10-30 signatures=0 X-Proofpoint-Spam-Details: rule=mpy_notspam policy=mpy score=0 spamscore=0 malwarescore=0 suspectscore=2 mlxscore=0 mlxlogscore=999 adultscore=0 bulkscore=0 phishscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2010300095 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello Gao Xiang, On 10/22/20 5:57 PM, Gao Xiang via Linux-erofs wrote: > From: Gao Xiang > > pcluster should be only set up for all managed pages instead of > temporary pages. Since it currently uses page->mapping to identify, > the impact is minor for now. > > Fixes: 5ddcee1f3a1c ("erofs: get rid of __stagingpage_alloc helper") > Cc: # 5.5+ > Signed-off-by: Gao Xiang I was looking exactly at this problem recently, my change is one-to-one to your fix, thus I can provide a tag: Tested-by: Vladimir Zapolskiy The fixed problem is minor, but the kernel log becomes polluted, if a page allocation debug option is enabled: % md5sum ~/erofs/testfile BUG: Bad page state in process kworker/u9:0 pfn:687de page:0000000057b8bcb4 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x687de flags: 0x4000000000002000(private) raw: 4000000000002000 dead000000000100 dead000000000122 0000000000000000 raw: 0000000000000000 ffff888066758690 00000000ffffffff 0000000000000000 page dumped because: PAGE_FLAGS_CHECK_AT_FREE flag(s) set Modules linked in: CPU: 1 PID: 602 Comm: kworker/u9:0 Not tainted 5.9.1 #2 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1 04/01/2014 Workqueue: erofs_unzipd z_erofs_decompressqueue_work Call Trace: dump_stack+0x84/0xba bad_page.cold+0xac/0xb1 check_free_page_bad+0xb0/0xc0 free_pcp_prepare+0x2c8/0x2d0 free_unref_page+0x18/0xf0 put_pages_list+0x11a/0x120 z_erofs_decompressqueue_work+0xc9/0x110 ? z_erofs_decompress_pcluster.isra.0+0xf10/0xf10 ? read_word_at_a_time+0x12/0x20 ? strscpy+0xc7/0x1a0 process_one_work+0x30c/0x730 worker_thread+0x91/0x640 ? __kasan_check_read+0x11/0x20 ? rescuer_thread+0x8a0/0x8a0 kthread+0x1dd/0x200 ? kthread_unpark+0xa0/0xa0 ret_from_fork+0x1f/0x30 Disabling lock debugging due to kernel taint -- Best wishes, Vladimir