linux-ext4 - Re: [PATCH 2/2] jbd2: Do not try to recover wiped journal

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <d191d727-2496-4272-8c2a-b97aa5eec3f8@huawei.com>
Date: Tue, 11 Feb 2025 11:14:55 +0800
From: Zhang Yi <yi.zhang@...wei.com>
To: Jan Kara <jack@...e.cz>
CC: <linux-ext4@...r.kernel.org>, Ted Tso <tytso@....edu>
Subject: Re: [PATCH 2/2] jbd2: Do not try to recover wiped journal

On 2025/2/6 17:46, Jan Kara wrote:
> If a journal is wiped, we will set journal->j_tail to 0. However if
> 'write' argument is not set (as it happens for read-only device or for
> ocfs2), the on-disk superblock is not updated accordingly and thus
> jbd2_journal_recover() cat try to recover the wiped journal. Fix the
> check in jbd2_journal_recover() to use journal->j_tail for checking
> empty journal instead.
> 
> Signed-off-by: Jan Kara <jack@...e.cz>

Ha, right, it looks good to me.

Reviewed-by: Zhang Yi <yi.zhang@...wei.com>

> ---
>  fs/jbd2/recovery.c | 11 ++++++-----
>  1 file changed, 6 insertions(+), 5 deletions(-)
> 
> diff --git a/fs/jbd2/recovery.c b/fs/jbd2/recovery.c
> index 9192be7c19d8..23502f1a67c1 100644
> --- a/fs/jbd2/recovery.c
> +++ b/fs/jbd2/recovery.c
> @@ -287,19 +287,20 @@ static int fc_do_one_pass(journal_t *journal,
>  int jbd2_journal_recover(journal_t *journal)
>  {
>  	int			err, err2;
> -	journal_superblock_t *	sb;
> -
>  	struct recovery_info	info;
>  
>  	memset(&info, 0, sizeof(info));
> -	sb = journal->j_superblock;
>  
>  	/*
>  	 * The journal superblock's s_start field (the current log head)
>  	 * is always zero if, and only if, the journal was cleanly
> -	 * unmounted.
> +	 * unmounted. We use its in-memory version j_tail here because
> +	 * jbd2_journal_wipe() could have updated it without updating journal
> +	 * superblock.
>  	 */
> -	if (!sb->s_start) {
> +	if (!journal->j_tail) {
> +		journal_superblock_t *sb = journal->j_superblock;
> +
>  		jbd2_debug(1, "No recovery required, last transaction %d, head block %u\n",
>  			  be32_to_cpu(sb->s_sequence), be32_to_cpu(sb->s_head));
>  		journal->j_transaction_sequence = be32_to_cpu(sb->s_sequence) + 1;