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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 61E40C433FE for ; Mon, 7 Nov 2022 14:51:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232433AbiKGOvh (ORCPT ); Mon, 7 Nov 2022 09:51:37 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33908 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231527AbiKGOve (ORCPT ); Mon, 7 Nov 2022 09:51:34 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5CB171A817 for ; Mon, 7 Nov 2022 06:51:33 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id F07FB61146 for ; Mon, 7 Nov 2022 14:51:32 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1B22CC433C1; Mon, 7 Nov 2022 14:51:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1667832692; bh=FkN6S5b4LUuRdRi3lyMah/SfaGO7kTVajUyQza/pc8I=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=rpDPq3JIJCrAO+SoKiIixRKufJ/gDJ/BfaEYaECxpcNsLVY8SEHgxbO2cOb1pIR+k degcjVUP2oDTKKNv1sb8qW2gZ6ebMNsb3OkaSpje6OBchvRLELT26GIp8YXxaaJi7B Xjc1U5suralpSoh/aOLdzw/vpksdt/kSxzcYOd8ImG3RuXoKYfTnxn1dgOHmKvztIG vKmN4XwScwmZwB85NT5mSn6vdXXBnTFxjBAjfJUyrrRbrYNeI85IlChfe736xnIYeP 9mc1r3PmbRmBWbCxs38RSb9sXeSNwZantKWcTJJ0L9L5TlDiU4vCZ9V0rqRN9Yvfqw YjgVhpbyDMseQ== Message-ID: <33a06664-cfad-f8dc-e11e-58106bfa1890@kernel.org> Date: Mon, 7 Nov 2022 22:51:28 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.3.1 Subject: Re: [PATCH] f2fs: fix atgc bug on issue in 32bits platform Content-Language: en-US To: Zhiguo Niu Cc: "zhiguo.niu" , jaegeuk@kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org References: <1667547621-26175-1-git-send-email-zhiguo.niu@unisoc.com> <9e22b747-5e59-9a1c-5ff1-fd4f2d6e43fc@kernel.org> From: Chao Yu In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2022/11/7 13:04, Zhiguo Niu wrote: > Dear Chao > > Chao Yu > 于2022年11月7日周一 09:25写道： > > On 2022/11/4 15:40, zhiguo.niu wrote: > > From: Zhiguo Niu > > > > > There is bug on issue after atgc feature is enabled in > > 32bits platform as the following log: > > > > F2FS-fs (dm-x): inconsistent rbtree, cur(3470333575168) next(3320009719808) > > ------------[ cut here ]------------ > > kernel BUG at fs/f2fs/gc.c:602! > > Internal error: Oops - BUG: 0 [#1] PREEMPT SMP ARM > > PC is at get_victim_by_default+0x13c0/0x1498 > > LR is at f2fs_check_rb_tree_consistence+0xc4/0xd4 > > .... > > [] (get_victim_by_default) from [] (f2fs_gc+0x220/0x6cc) > > [] (f2fs_gc) from [] (gc_thread_func+0x2ac/0x708) > > [] (gc_thread_func) from [] (kthread+0x1a8/0x1b4) > > [] (kthread) from [] (ret_from_fork+0x14/0x20) > > > > The reason is the 64bits key in struct rb_entry has __packed attibute > > but has not in struct victim_entry, so the wrong key value got by > > in f2fs_check_rb_tree_consistence, the following are the memory layouts > > of struct rb_entry and struct victim_entry in 32bits platform: > > > > struct rb_entry { > >     [0] struct rb_node rb_node; > >         union { > >             struct {...}; > >    [12]     unsigned long long key; > >         }; > > } > > struct victim_entry { > >     [0] struct rb_node rb_node; > >         union { > >             struct {...}; > >    [16]     struct victim_info vi; > >         }; > >    [32] struct list_head list; > > } > > Shouldn't we add __packed for struct victim_entry? > >  I try to keep it consistent with struct rb_entry (__packed is only added to union for 64bits key), > victim_entry.vi.mtime is used to store the key, and rb_entry.key is used to verify the key, > so make sure that the memory offsets of the 64 bits key in these two structures are the same. > Other members of victim_entry, such as list, i think there is no problem because of it storaged and loaded > are both based on struct victim_entry I'm not sure, there will be any further update in struct rb_node and struct list_head later, so, IMO, it will be more safe to add __packed to align all fields in structure to byte. Thanks, > > > > > This patch fix this inconsistence layout of 64bits key between > > struct rb_entry and struct victim_entry. > > > > Fixes: 093749e296e2 ("f2fs: support age threshold based garbage collection") > > > Signed-off-by: Zhiguo Niu > >