Received-SPF: pass (google.com: domain of linux-ext4-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Content-Type: text/plain;
        charset=utf-8
Mime-Version: 1.0 (Mac OS X Mail 16.0 \(3696.120.41.1.1\))
Subject: Re: [PATCH RFC] jbd2: detect old record when do journal scan
From:   fengnan chang <fengnanchang@gmail.com>
In-Reply-To: <62FF430D.9040405@huawei.com>
Date:   Fri, 19 Aug 2022 16:34:28 +0800
Cc:     "tytso@mit.edu" <tytso@mit.edu>, adilger.kernel@dilger.ca,
        linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org,
        jack@suse.cz
Content-Transfer-Encoding: quoted-printable
Message-Id: <A602BE93-1AE5-43D7-B42B-D991E24AC933@gmail.com>
References: <20220810013442.3474533-1-yebin10@huawei.com>
 <62FF430D.9040405@huawei.com>
To:     yebin <yebin10@huawei.com>
Precedence: bulk

If there has system time calibration, system time has become smaller, =
what will be happen?
the journal maybe thought as corrupt?


> 2022=E5=B9=B48=E6=9C=8819=E6=97=A5 16:00=EF=BC=8Cyebin =
<yebin10@huawei.com> =E5=86=99=E9=81=93=EF=BC=9A
>=20
> ping...
>=20
> On 2022/8/10 9:34, Ye Bin wrote:
>> As https://github.com/tytso/e2fsprogs/issues/120 describe tune2fs do =
not update
>> j_tail_sequence when do journal recovery. This maybe recover old =
journal record,
>> then will lead to file system corruption.
>> To avoid file system corruption in this case, if detect current =
transaction's
>> commit time earlier than previous transaction's commit time when do =
journal
>> scan, just return error.
>>=20
>> Signed-off-by: Ye Bin <yebin10@huawei.com>
>> ---
>>  fs/jbd2/recovery.c | 11 ++++++++++-
>>  1 file changed, 10 insertions(+), 1 deletion(-)
>>=20
>> diff --git a/fs/jbd2/recovery.c b/fs/jbd2/recovery.c
>> index f548479615c6..f3def21a96a5 100644
>> --- a/fs/jbd2/recovery.c
>> +++ b/fs/jbd2/recovery.c
>> @@ -812,8 +812,17 @@ static int do_one_pass(journal_t *journal,
>>  					break;
>>  				}
>>  			}
>> -			if (pass =3D=3D PASS_SCAN)
>> +			if (pass =3D=3D PASS_SCAN) {
>> +				if (commit_time < =
last_trans_commit_time) {
>> +					pr_err("JBD2: old journal record =
found "
>> +					       "in transaction %u\n",
>> +					       next_commit_ID);
>> +					err =3D -EFSBADCRC;
>> +					brelse(bh);
>> +					goto failed;
>> +				}
>>  				last_trans_commit_time =3D commit_time;
>> +			}
>>  			brelse(bh);
>>  			next_commit_ID++;
>>  			continue;
>=20