Re: [PATCH v3 1/2] ext4: commit super block if fs record error when journal record without error

["yebin (H)" <yebin10@huawei.com>]

On 2023/2/16 15:17, Baokun Li wrote:
> On 2023/2/14 10:29, Ye Bin wrote:
>> From: Ye Bin <yebin10@huawei.com>
>>
>> Now, 'es->s_state' maybe covered by recover journal. And journal errno
>> maybe not recorded in journal sb as IO error. ext4_update_super() only
>> update error information when 'sbi->s_add_error_count' large than zero.
>> Then 'EXT4_ERROR_FS' flag maybe lost.
>> To solve above issue commit error information after recover journal.
>>
>> Signed-off-by: Ye Bin <yebin10@huawei.com>
>> ---
>>   fs/ext4/super.c | 12 ++++++++++++
>>   1 file changed, 12 insertions(+)
>>
>> diff --git a/fs/ext4/super.c b/fs/ext4/super.c
>> index dc3907dff13a..b94754ba8556 100644
>> --- a/fs/ext4/super.c
>> +++ b/fs/ext4/super.c
>> @@ -5932,6 +5932,18 @@ static int ext4_load_journal(struct 
>> super_block *sb,
>>           goto err_out;
>>       }
>>   +    if (unlikely(es->s_error_count && !jbd2_journal_errno(journal) &&
>> +             !(le16_to_cpu(es->s_state) & EXT4_ERROR_FS))) {
>> +        EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
>> +        es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
>> +        err = ext4_commit_super(sb);
>> +        if (err) {
>> +            ext4_msg(sb, KERN_ERR,
>> +                 "Failed to commit error information, please repair 
>> fs force!");
>> +            goto err_out;
>> +        }
>> +    }
>> +
>>       EXT4_SB(sb)->s_journal = journal;
>>       err = ext4_clear_journal_err(sb, es);
>>       if (err) {
> I think we don't need such a complicated judgment, after the journal 
> replay and saving the error info,
> if there is EXT4_ERROR_FS flag in ext4_sb_info->s_mount_state, just 
> add this flag directly to es->s_state.
> This way the EXT4_ERROR_FS flag and the error message will be written 
> to disk the next time

Thanks for your suggestion. There are two reasons for this:
1. We want to write the error mark to the disk as soon as possible.
2. Here we deal with the case where there is no error mark bit but there 
is an error record.
In this case, the file system should be marked with an error and the 
user should be prompted.
> ext4_commit_super() is executed. The code change is as follows:
>
> diff --git a/fs/ext4/super.c b/fs/ext4/super.c
> index 260c1b3e3ef2..341b11c589b3 100644
> --- a/fs/ext4/super.c
> +++ b/fs/ext4/super.c
> @@ -5935,6 +5935,7 @@ static int ext4_load_journal(struct super_block 
> *sb,
>                         memcpy(((char *) es) + EXT4_S_ERR_START,
>                                save, EXT4_S_ERR_LEN);
>                 kfree(save);
> +               es->s_state |= cpu_to_le16(EXT4_SB(sb)->s_mount_state 
> & EXT4_ERROR_FS);
>         }
>
>         if (err) {
>