Subject: Re: [PATCH 4/5] jbd2: factor out journal initialization from
 journal_get_superblock()
To:     Jan Kara <jack@suse.cz>, Zhihao Cheng <chengzhihao1@huawei.com>
CC:     <tytso@mit.edu>, <adilger.kernel@dilger.ca>, <jack@suse.com>,
        <linux-ext4@vger.kernel.org>, <linux-kernel@vger.kernel.org>
References: <20230310125206.2867822-1-chengzhihao1@huawei.com>
 <20230310125206.2867822-5-chengzhihao1@huawei.com>
 <20230313111253.2eoplgfhcgbaqri2@quack3>
From:   Zhang Yi <yi.zhang@huawei.com>
Message-ID: <a1aef56e-652e-793c-3913-c083119d4b45@huawei.com>
Date:   Mon, 13 Mar 2023 20:48:11 +0800
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On 2023/3/13 19:12, Jan Kara wrote:
> On Fri 10-03-23 20:52:05, Zhihao Cheng wrote:
>> From: Zhang Yi <yi.zhang@huawei.com>
>>
>> Current journal_get_superblock() couple journal superblock checking and
>> partial journal initialization, factor out initialization part from it
>> to make things clear.
>>
>> Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
>> Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>
>> ---
>>  fs/jbd2/journal.c | 52 ++++++++++++++++++++---------------------------
>>  1 file changed, 22 insertions(+), 30 deletions(-)
> 
> The patch looks mostly good. Just one style nit below.
> 
>> diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
>> index b991d5c21d16..cd94d068b4e6 100644
>> --- a/fs/jbd2/journal.c
>> +++ b/fs/jbd2/journal.c
>> @@ -1921,26 +1921,15 @@ static int journal_get_superblock(journal_t *journal)
>>  		printk(KERN_WARNING "JBD2: no valid journal superblock found\n");
>>  		goto out;
>>  	}
>> -
>> -	switch(be32_to_cpu(sb->s_header.h_blocktype)) {
>> -	case JBD2_SUPERBLOCK_V1:
>> -		journal->j_format_version = 1;
>> -		break;
>> -	case JBD2_SUPERBLOCK_V2:
>> -		journal->j_format_version = 2;
>> -		break;
>> -	default:
>> +	if (be32_to_cpu(sb->s_header.h_blocktype) != JBD2_SUPERBLOCK_V1 &&
>> +	    be32_to_cpu(sb->s_header.h_blocktype) != JBD2_SUPERBLOCK_V2) {
>>  		printk(KERN_WARNING "JBD2: unrecognised superblock format ID\n");
>>  		goto out;
>>  	}
>> -
>> -	if (be32_to_cpu(sb->s_maxlen) < journal->j_total_len)
>> -		journal->j_total_len = be32_to_cpu(sb->s_maxlen);
>> -	else if (be32_to_cpu(sb->s_maxlen) > journal->j_total_len) {
>> +	if (be32_to_cpu(sb->s_maxlen) > journal->j_total_len) {
>>  		printk(KERN_WARNING "JBD2: journal file too short\n");
>>  		goto out;
>>  	}
>> -
> 
> Please keep this empty line here. It actually makes the code more readable,
> separating logically different checks. Same with three empty lines below...

Thanks for the comments, I will add them back.

Yi.