Re: [PATCH RFC] jbd2: detect old record when do journal scan

[fengnan chang]

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


> 2022年8月19日 16:00，yebin <yebin10@xxxxxxxxxx> 写道：
> 
> ping...
> 
> 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.
>> 
>> Signed-off-by: Ye Bin <yebin10@xxxxxxxxxx>
>> ---
>>  fs/jbd2/recovery.c | 11 ++++++++++-
>>  1 file changed, 10 insertions(+), 1 deletion(-)
>> 
>> 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 == PASS_SCAN)
>> +			if (pass == PASS_SCAN) {
>> +				if (commit_time < last_trans_commit_time) {
>> +					pr_err("JBD2: old journal record found "
>> +					       "in transaction %u\n",
>> +					       next_commit_ID);
>> +					err = -EFSBADCRC;
>> +					brelse(bh);
>> +					goto failed;
>> +				}
>>  				last_trans_commit_time = commit_time;
>> +			}
>>  			brelse(bh);
>>  			next_commit_ID++;
>>  			continue;
>