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 AF401C433EF for ; Wed, 22 Dec 2021 14:37:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1343499AbhLVOh7 (ORCPT ); Wed, 22 Dec 2021 09:37:59 -0500 Received: from smtp-out1.suse.de ([195.135.220.28]:54228 "EHLO smtp-out1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238818AbhLVOh6 (ORCPT ); Wed, 22 Dec 2021 09:37:58 -0500 Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out1.suse.de (Postfix) with ESMTP id C4AD6212B7; Wed, 22 Dec 2021 14:37:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1640183877; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=gc7GULz8GdRORFE4g+VjvQfetQYn3CecFaan/rOImzU=; b=pp2MQa4g4afqeHnnbpstvRRU0/qWMlW3OK2cev8JBu+h0CU2G607lmDtWIKsVNc5MPiGlf UQYbLtLeBmrUAxD4kratrxEyvquGjz1GfnyYp2i/V7jM0BhhPl2n1Km6Hqp2GGdldC0qqR hD2XX1rjZZsYBlFXLZ+Ujjay4STNAgA= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1640183877; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=gc7GULz8GdRORFE4g+VjvQfetQYn3CecFaan/rOImzU=; b=E33r5WLDqBxz72e8y/vh9Rj8eAHM6hee0L1G3De5TXXGsSaRB+ut2Ly/Amuo1Ed0D7oG7w Kp9twdzYx7wOzdAg== Received: from quack2.suse.cz (unknown [10.163.28.18]) by relay2.suse.de (Postfix) with ESMTP id B0536A3B81; Wed, 22 Dec 2021 14:37:57 +0000 (UTC) Received: by quack2.suse.cz (Postfix, from userid 1000) id 832E51F2CEF; Wed, 22 Dec 2021 15:37:57 +0100 (CET) Date: Wed, 22 Dec 2021 15:37:57 +0100 From: Jan Kara To: Ye Bin Cc: tytso@mit.edu, adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org, jack@suse.cz Subject: Re: [PATCH -next] ext4: Fix BUG_ON in ext4_bread when write quota data Message-ID: <20211222143757.GD685@quack2.suse.cz> References: <20211222013537.3096310-1-yebin10@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20211222013537.3096310-1-yebin10@huawei.com> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org On Wed 22-12-21 09:35:37, Ye Bin wrote: > We got issue as follows when run syzkaller: > [ 167.936972] EXT4-fs error (device loop0): __ext4_remount:6314: comm rep: Abort forced by user > [ 167.938306] EXT4-fs (loop0): Remounting filesystem read-only > [ 167.981637] Assertion failure in ext4_getblk() at fs/ext4/inode.c:847: '(EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY) || handle != NULL || create == 0' > [ 167.983601] ------------[ cut here ]------------ > [ 167.984245] kernel BUG at fs/ext4/inode.c:847! > [ 167.984882] invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI > [ 167.985624] CPU: 7 PID: 2290 Comm: rep Tainted: G B 5.16.0-rc5-next-20211217+ #123 > [ 167.986823] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20190727_073836-buildvm-ppc64le-16.ppc.fedoraproject.org-3.fc31 04/01/2014 > [ 167.988590] RIP: 0010:ext4_getblk+0x17e/0x504 > [ 167.989189] Code: c6 01 74 28 49 c7 c0 a0 a3 5c 9b b9 4f 03 00 00 48 c7 c2 80 9c 5c 9b 48 c7 c6 40 b6 5c 9b 48 c7 c7 20 a4 5c 9b e8 77 e3 fd ff <0f> 0b 8b 04 244 > [ 167.991679] RSP: 0018:ffff8881736f7398 EFLAGS: 00010282 > [ 167.992385] RAX: 0000000000000094 RBX: 1ffff1102e6dee75 RCX: 0000000000000000 > [ 167.993337] RDX: 0000000000000001 RSI: ffffffff9b6e29e0 RDI: ffffed102e6dee66 > [ 167.994292] RBP: ffff88816a076210 R08: 0000000000000094 R09: ffffed107363fa09 > [ 167.995252] R10: ffff88839b1fd047 R11: ffffed107363fa08 R12: ffff88816a0761e8 > [ 167.996205] R13: 0000000000000000 R14: 0000000000000021 R15: 0000000000000001 > [ 167.997158] FS: 00007f6a1428c740(0000) GS:ffff88839b000000(0000) knlGS:0000000000000000 > [ 167.998238] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [ 167.999025] CR2: 00007f6a140716c8 CR3: 0000000133216000 CR4: 00000000000006e0 > [ 167.999987] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > [ 168.000944] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > [ 168.001899] Call Trace: > [ 168.002235] > [ 168.007167] ext4_bread+0xd/0x53 > [ 168.007612] ext4_quota_write+0x20c/0x5c0 > [ 168.010457] write_blk+0x100/0x220 > [ 168.010944] remove_free_dqentry+0x1c6/0x440 > [ 168.011525] free_dqentry.isra.0+0x565/0x830 > [ 168.012133] remove_tree+0x318/0x6d0 > [ 168.014744] remove_tree+0x1eb/0x6d0 > [ 168.017346] remove_tree+0x1eb/0x6d0 > [ 168.019969] remove_tree+0x1eb/0x6d0 > [ 168.022128] qtree_release_dquot+0x291/0x340 > [ 168.023297] v2_release_dquot+0xce/0x120 > [ 168.023847] dquot_release+0x197/0x3e0 > [ 168.024358] ext4_release_dquot+0x22a/0x2d0 > [ 168.024932] dqput.part.0+0x1c9/0x900 > [ 168.025430] __dquot_drop+0x120/0x190 > [ 168.025942] ext4_clear_inode+0x86/0x220 > [ 168.026472] ext4_evict_inode+0x9e8/0xa22 > [ 168.028200] evict+0x29e/0x4f0 > [ 168.028625] dispose_list+0x102/0x1f0 > [ 168.029148] evict_inodes+0x2c1/0x3e0 > [ 168.030188] generic_shutdown_super+0xa4/0x3b0 > [ 168.030817] kill_block_super+0x95/0xd0 > [ 168.031360] deactivate_locked_super+0x85/0xd0 > [ 168.031977] cleanup_mnt+0x2bc/0x480 > [ 168.033062] task_work_run+0xd1/0x170 > [ 168.033565] do_exit+0xa4f/0x2b50 > [ 168.037155] do_group_exit+0xef/0x2d0 > [ 168.037666] __x64_sys_exit_group+0x3a/0x50 > [ 168.038237] do_syscall_64+0x3b/0x90 > [ 168.038751] entry_SYSCALL_64_after_hwframe+0x44/0xae > > In order to reproduce this problem, the following conditions need to be met: > 1. Ext4 filesystem with no journal; > 2. Filesystem image with incorrect quota data; > 3. Abort filesystem forced by user; > 4. umount filesystem; > > As in ext4_quota_write: > ... > if (EXT4_SB(sb)->s_journal && !handle) { > ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)" > " cancelled because transaction is not started", > (unsigned long long)off, (unsigned long long)len); > return -EIO; > } > ... > We only check handle if NULL when filesystem has journal. There is need > check handle if NULL even when filesystem has no journal. Hum, so I think we can just drop this whole condition and warning and instead add a silent return of -EROFS if the filesystem is readonly. That should also fix the bug and also make aborted case less noisy. The message from ext4_quota_write() IMO is not very useful and ext4_bread() will provide us with a BUG and stacktrace which is better for debugging what went wrong anyway. Honza > > Signed-off-by: Ye Bin > --- > fs/ext4/super.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/fs/ext4/super.c b/fs/ext4/super.c > index 071b7b3c5678..c8ca5811ea65 100644 > --- a/fs/ext4/super.c > +++ b/fs/ext4/super.c > @@ -6955,9 +6955,10 @@ static ssize_t ext4_quota_write(struct super_block *sb, int type, > struct buffer_head *bh; > handle_t *handle = journal_current_handle(); > > - if (EXT4_SB(sb)->s_journal && !handle) { > + if (!handle) { > ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)" > - " cancelled because transaction is not started", > + " cancelled because transaction is not started" > + " or filesystem is abort forced by user", > (unsigned long long)off, (unsigned long long)len); > return -EIO; > } > -- > 2.31.1 > -- Jan Kara SUSE Labs, CR