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=-3.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 0144DC3B189 for ; Thu, 13 Feb 2020 15:40:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CA18D217F4 for ; Thu, 13 Feb 2020 15:40:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387786AbgBMPk0 (ORCPT ); Thu, 13 Feb 2020 10:40:26 -0500 Received: from outgoing-auth-1.mit.edu ([18.9.28.11]:54668 "EHLO outgoing.mit.edu" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2387776AbgBMPkZ (ORCPT ); Thu, 13 Feb 2020 10:40:25 -0500 Received: from callcc.thunk.org (guestnat-104-133-0-101.corp.google.com [104.133.0.101] (may be forged)) (authenticated bits=0) (User authenticated as tytso@ATHENA.MIT.EDU) by outgoing.mit.edu (8.14.7/8.12.4) with ESMTP id 01DFe3sU018178 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 13 Feb 2020 10:40:04 -0500 Received: by callcc.thunk.org (Postfix, from userid 15806) id 7204642032C; Thu, 13 Feb 2020 10:40:03 -0500 (EST) Date: Thu, 13 Feb 2020 10:40:03 -0500 From: "Theodore Y. Ts'o" To: Shijie Luo Cc: linux-ext4@vger.kernel.org, jack@suse.cz, yi.zhang@huawei.com, lutianxiong@huawei.com Subject: Re: [PATCH v2] ext4: add cond_resched() to ext4_protect_reserved_inode Message-ID: <20200213154003.GE239974@mit.edu> References: <20200211011752.29242-1-luoshijie1@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200211011752.29242-1-luoshijie1@huawei.com> Sender: linux-ext4-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org On Mon, Feb 10, 2020 at 08:17:52PM -0500, Shijie Luo wrote: > When journal size is set too big by "mkfs.ext4 -J size=", or when > we mount a crafted image to make journal inode->i_size too big, > the loop, "while (i < num)", holds cpu too long. This could cause > soft lockup. > > [ 529.357541] Call trace: > [ 529.357551] dump_backtrace+0x0/0x198 > [ 529.357555] show_stack+0x24/0x30 > [ 529.357562] dump_stack+0xa4/0xcc > [ 529.357568] watchdog_timer_fn+0x300/0x3e8 > [ 529.357574] __hrtimer_run_queues+0x114/0x358 > [ 529.357576] hrtimer_interrupt+0x104/0x2d8 > [ 529.357580] arch_timer_handler_virt+0x38/0x58 > [ 529.357584] handle_percpu_devid_irq+0x90/0x248 > [ 529.357588] generic_handle_irq+0x34/0x50 > [ 529.357590] __handle_domain_irq+0x68/0xc0 > [ 529.357593] gic_handle_irq+0x6c/0x150 > [ 529.357595] el1_irq+0xb8/0x140 > [ 529.357599] __ll_sc_atomic_add_return_acquire+0x14/0x20 > [ 529.357668] ext4_map_blocks+0x64/0x5c0 [ext4] > [ 529.357693] ext4_setup_system_zone+0x330/0x458 [ext4] > [ 529.357717] ext4_fill_super+0x2170/0x2ba8 [ext4] > [ 529.357722] mount_bdev+0x1a8/0x1e8 > [ 529.357746] ext4_mount+0x44/0x58 [ext4] > [ 529.357748] mount_fs+0x50/0x170 > [ 529.357752] vfs_kern_mount.part.9+0x54/0x188 > [ 529.357755] do_mount+0x5ac/0xd78 > [ 529.357758] ksys_mount+0x9c/0x118 > [ 529.357760] __arm64_sys_mount+0x28/0x38 > [ 529.357764] el0_svc_common+0x78/0x130 > [ 529.357766] el0_svc_handler+0x38/0x78 > [ 529.357769] el0_svc+0x8/0xc > [ 541.356516] watchdog: BUG: soft lockup - CPU#0 stuck for 23s! [mount:18674] > > Signed-off-by: Shijie Luo > Reviewed-by: Jan Kara Applied, thanks. - Ted