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=-11.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 326DEC433E3 for ; Wed, 5 Aug 2020 20:05:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1A48D22B42 for ; Wed, 5 Aug 2020 20:05:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727884AbgHEUFl (ORCPT ); Wed, 5 Aug 2020 16:05:41 -0400 Received: from mx2.suse.de ([195.135.220.15]:58434 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727793AbgHEQf6 (ORCPT ); Wed, 5 Aug 2020 12:35:58 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 3617EB5FD; Wed, 5 Aug 2020 14:16:40 +0000 (UTC) Received: by quack2.suse.cz (Postfix, from userid 1000) id 54C291E12CB; Wed, 5 Aug 2020 16:16:23 +0200 (CEST) Date: Wed, 5 Aug 2020 16:16:23 +0200 From: Jan Kara To: Ted Tso Cc: linux-ext4@vger.kernel.org, Lukas Czerner , Jan Kara Subject: Re: [PATCH v3] ext4: don't BUG on inconsistent journal feature Message-ID: <20200805141623.GC16475@quack2.suse.cz> References: <20200710140759.18031-1-jack@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200710140759.18031-1-jack@suse.cz> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-ext4-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org On Fri 10-07-20 16:07:59, 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. We issue warning and fail the mount > in the cases where the race window is narrow and the failed check is > most likely a programming error. In cases where fs corruption is more > likely, we do full ext4_error() handling before failing mount / remount. > > Reviewed-by: Lukas Czerner > Signed-off-by: Jan Kara Ted, can you please pick up this patch? Thanks! Honza > --- > fs/ext4/super.c | 68 +++++++++++++++++++++++++++++++++++++++------------------ > 1 file changed, 47 insertions(+), 21 deletions(-) > > Changes since v2: > - added Reviewed-by tag > - fixup compilation failure without CONFIG_QUOTA > > Changes since v1: > - handle failures more likely coming from fs corruption as with ext4_error > > diff --git a/fs/ext4/super.c b/fs/ext4/super.c > index 330957ed1f05..9fdad843b30e 100644 > --- a/fs/ext4/super.c > +++ b/fs/ext4/super.c > @@ -66,10 +66,10 @@ static int ext4_load_journal(struct super_block *, struct ext4_super_block *, > unsigned long journal_devnum); > 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, > +static int 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); > @@ -4770,7 +4770,9 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent) > EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS; > if (needs_recovery) { > ext4_msg(sb, KERN_INFO, "recovery complete"); > - ext4_mark_recovery_complete(sb, es); > + err = ext4_mark_recovery_complete(sb, es); > + if (err) > + goto failed_mount8; > } > if (EXT4_SB(sb)->s_journal) { > if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) > @@ -4813,10 +4815,8 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent) > ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem"); > goto failed_mount; > > -#ifdef CONFIG_QUOTA > failed_mount8: > ext4_unregister_sysfs(sb); > -#endif > failed_mount7: > ext4_unregister_li_request(sb); > failed_mount6: > @@ -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)) { > @@ -5244,26 +5252,32 @@ static int ext4_commit_super(struct super_block *sb, int sync) > * remounting) the filesystem readonly, then we will end up with a > * consistent fs on disk. Record that fact. > */ > -static void ext4_mark_recovery_complete(struct super_block *sb, > - struct ext4_super_block *es) > +static int ext4_mark_recovery_complete(struct super_block *sb, > + struct ext4_super_block *es) > { > + int err; > journal_t *journal = EXT4_SB(sb)->s_journal; > > if (!ext4_has_feature_journal(sb)) { > - BUG_ON(journal != NULL); > - return; > + if (journal != NULL) { > + ext4_error(sb, "Journal got removed while the fs was " > + "mounted!"); > + return -EFSCORRUPTED; > + } > + return 0; > } > jbd2_journal_lock_updates(journal); > - if (jbd2_journal_flush(journal) < 0) > + err = jbd2_journal_flush(journal); > + if (err < 0) > goto out; > > if (ext4_has_feature_journal_needs_recovery(sb) && sb_rdonly(sb)) { > ext4_clear_feature_journal_needs_recovery(sb); > ext4_commit_super(sb, 1); > } > - > out: > jbd2_journal_unlock_updates(journal); > + return err; > } > > /* > @@ -5271,14 +5285,17 @@ 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 (!ext4_has_feature_journal(sb)) { > + ext4_error(sb, "Journal got removed while the fs was mounted!"); > + return -EFSCORRUPTED; > + } > > journal = EXT4_SB(sb)->s_journal; > > @@ -5303,6 +5320,7 @@ static void ext4_clear_journal_err(struct super_block *sb, > jbd2_journal_clear_err(journal); > jbd2_journal_update_sb_errno(journal); > } > + return 0; > } > > /* > @@ -5573,8 +5591,13 @@ static int ext4_remount(struct super_block *sb, int *flags, char *data) > (sbi->s_mount_state & EXT4_VALID_FS)) > es->s_state = cpu_to_le16(sbi->s_mount_state); > > - if (sbi->s_journal) > + if (sbi->s_journal) { > + /* > + * We let remount-ro finish even if marking fs > + * as clean failed... > + */ > ext4_mark_recovery_complete(sb, es); > + } > if (sbi->s_mmp_tsk) > kthread_stop(sbi->s_mmp_tsk); > } else { > @@ -5622,8 +5645,11 @@ 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 > -- Jan Kara SUSE Labs, CR