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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 1846FC433DF for ; Thu, 9 Jul 2020 12:37:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E88102076A for ; Thu, 9 Jul 2020 12:37:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="CBfb2U+0" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726443AbgGIMhF (ORCPT ); Thu, 9 Jul 2020 08:37:05 -0400 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:48344 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726327AbgGIMhD (ORCPT ); Thu, 9 Jul 2020 08:37:03 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1594298221; h=from:from:reply-to:subject:subject: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=chflHkeu9/+34UfQSK8HKBjbRjDjN1sXIPcAXIQZ+zo=; b=CBfb2U+0kZIw1zCFmC/dFIBwAxmoMOP4EVre8O2sl+6QuTPDJKOPtgOQtwh44CdGN27gOf +NVs9Zl6vMdSRlqA8RKODpPiFVpuyWLZtvWu7tN8oEz1Sr/O62Ble/1Xu0jE4Ln1qktkQo KgCU2Zj7w5SBveVvNEkKAC2Y2KiQ1rs= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-484-Rtkt7ZjhMXecWdlmNsPc2w-1; Thu, 09 Jul 2020 08:36:59 -0400 X-MC-Unique: Rtkt7ZjhMXecWdlmNsPc2w-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id D98688015FB; Thu, 9 Jul 2020 12:36:58 +0000 (UTC) Received: from work (unknown [10.40.192.254]) by smtp.corp.redhat.com (Postfix) with ESMTPS id E67E72DE69; Thu, 9 Jul 2020 12:36:57 +0000 (UTC) Date: Thu, 9 Jul 2020 14:36:55 +0200 From: Lukas Czerner To: Jan Kara Cc: Ted Tso , linux-ext4@vger.kernel.org Subject: Re: [PATCH] ext4: don't BUG on inconsistent journal feature Message-ID: <20200709123655.y7p7idrqukdi2he5@work> References: <20200709095854.3651-1-jack@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200709095854.3651-1-jack@suse.cz> X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Sender: linux-ext4-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org On Thu, Jul 09, 2020 at 11:58:54AM +0200, Jan Kara wrote: > A customer has reported a BUG_ON in ext4_clear_journal_err() hitting > during an LTP testing. Either this has been caused by a test setup > issue where the filesystem was being overwritten while LTP was mounting > it or the journal replay has overwritten the superblock with invalid > data. In either case it is preferable we don't take the machine down > with a BUG_ON. So handle the situation of unexpectedly missing > has_journal feature more gracefully by a WARN_ON_ONCE and bailing out > with error. > > Signed-off-by: Jan Kara > --- > fs/ext4/super.c | 35 ++++++++++++++++++++++++----------- > 1 file changed, 24 insertions(+), 11 deletions(-) > > diff --git a/fs/ext4/super.c b/fs/ext4/super.c > index 330957ed1f05..d8b7222cb86c 100644 > --- a/fs/ext4/super.c > +++ b/fs/ext4/super.c > @@ -68,8 +68,8 @@ static int ext4_show_options(struct seq_file *seq, struct dentry *root); > static int ext4_commit_super(struct super_block *sb, int sync); > static void ext4_mark_recovery_complete(struct super_block *sb, > struct ext4_super_block *es); > -static void ext4_clear_journal_err(struct super_block *sb, > - struct ext4_super_block *es); > +static int ext4_clear_journal_err(struct super_block *sb, > + struct ext4_super_block *es); > static int ext4_sync_fs(struct super_block *sb, int wait); > static int ext4_remount(struct super_block *sb, int *flags, char *data); > static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf); > @@ -4956,7 +4956,8 @@ static journal_t *ext4_get_journal(struct super_block *sb, > struct inode *journal_inode; > journal_t *journal; > > - BUG_ON(!ext4_has_feature_journal(sb)); > + if (WARN_ON_ONCE(!ext4_has_feature_journal(sb))) > + return NULL; > > journal_inode = ext4_get_journal_inode(sb, journal_inum); > if (!journal_inode) > @@ -4986,7 +4987,8 @@ static journal_t *ext4_get_dev_journal(struct super_block *sb, > struct ext4_super_block *es; > struct block_device *bdev; > > - BUG_ON(!ext4_has_feature_journal(sb)); > + if (WARN_ON_ONCE(!ext4_has_feature_journal(sb))) > + return NULL; > > bdev = ext4_blkdev_get(j_dev, sb); > if (bdev == NULL) > @@ -5078,7 +5080,8 @@ static int ext4_load_journal(struct super_block *sb, > int err = 0; > int really_read_only; > > - BUG_ON(!ext4_has_feature_journal(sb)); > + if (WARN_ON_ONCE(!ext4_has_feature_journal(sb))) > + return -EFSCORRUPTED; > > if (journal_devnum && > journal_devnum != le32_to_cpu(es->s_journal_dev)) { > @@ -5148,7 +5151,12 @@ static int ext4_load_journal(struct super_block *sb, > } > > EXT4_SB(sb)->s_journal = journal; > - ext4_clear_journal_err(sb, es); > + err = ext4_clear_journal_err(sb, es); > + if (err) { > + EXT4_SB(sb)->s_journal = NULL; > + jbd2_journal_destroy(journal); > + return err; > + } > > if (!really_read_only && journal_devnum && > journal_devnum != le32_to_cpu(es->s_journal_dev)) { > @@ -5250,7 +5258,7 @@ static void ext4_mark_recovery_complete(struct super_block *sb, > journal_t *journal = EXT4_SB(sb)->s_journal; > > if (!ext4_has_feature_journal(sb)) { > - BUG_ON(journal != NULL); > + WARN_ON_ONCE(journal != NULL); Hi Jan, If this ever happens we will hapily continue with fs operation after mount, or remount (remount is ro, so that is probably ok ?) without journal feature, but with s_journal set ? I am not quite sure what the consequences might be, are you sure this is ok ? -Lukas > return; > } > jbd2_journal_lock_updates(journal); > @@ -5271,14 +5279,15 @@ static void ext4_mark_recovery_complete(struct super_block *sb, > * has recorded an error from a previous lifetime, move that error to the > * main filesystem now. > */ > -static void ext4_clear_journal_err(struct super_block *sb, > +static int ext4_clear_journal_err(struct super_block *sb, > struct ext4_super_block *es) > { > journal_t *journal; > int j_errno; > const char *errstr; > > - BUG_ON(!ext4_has_feature_journal(sb)); > + if (WARN_ON_ONCE(!ext4_has_feature_journal(sb))) > + return -EFSCORRUPTED; > > journal = EXT4_SB(sb)->s_journal; > > @@ -5303,6 +5312,7 @@ static void ext4_clear_journal_err(struct super_block *sb, > jbd2_journal_clear_err(journal); > jbd2_journal_update_sb_errno(journal); > } > + return 0; > } > > /* > @@ -5622,8 +5632,11 @@ static int ext4_remount(struct super_block *sb, int *flags, char *data) > * been changed by e2fsck since we originally mounted > * the partition.) > */ > - if (sbi->s_journal) > - ext4_clear_journal_err(sb, es); > + if (sbi->s_journal) { > + err = ext4_clear_journal_err(sb, es); > + if (err) > + goto restore_opts; > + } > sbi->s_mount_state = le16_to_cpu(es->s_state); > > err = ext4_setup_super(sb, es, 0); > -- > 2.16.4 >