Date:   Wed, 15 Mar 2023 09:44:03 +0100
From:   Jan Kara <jack@suse.cz>
To:     Zhihao Cheng <chengzhihao1@huawei.com>
Cc:     tytso@mit.edu, adilger.kernel@dilger.ca, jack@suse.com,
        tudor.ambarus@linaro.org, linux-ext4@vger.kernel.org,
        linux-kernel@vger.kernel.org, yi.zhang@huawei.com
Subject: Re: [PATCH v3 2/6] ext4: ext4_put_super: Remove redundant checking
 for 'sbi->s_journal_bdev'
Message-ID: <20230315084403.krguix7veo4lsvgk@quack3>
References: <20230315013128.3911115-1-chengzhihao1@huawei.com>
 <20230315013128.3911115-3-chengzhihao1@huawei.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20230315013128.3911115-3-chengzhihao1@huawei.com>
Precedence: bulk

On Wed 15-03-23 09:31:24, Zhihao Cheng wrote:
> As discussed in [1], 'sbi->s_journal_bdev != sb->s_bdev' will always
> become true if sbi->s_journal_bdev exists. Filesystem block device and
> journal block device are both opened with 'FMODE_EXCL' mode, so these
> two devices can't be same one. Then we can remove the redundant checking
> 'sbi->s_journal_bdev != sb->s_bdev' if 'sbi->s_journal_bdev' exists.
> 
> [1] https://lore.kernel.org/lkml/f86584f6-3877-ff18-47a1-2efaa12d18b2@huawei.com/
> 
> Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>

Looks good. Feel free to add:

Reviewed-by: Jan Kara <jack@suse.cz>

								Honza

> ---
>  fs/ext4/super.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/fs/ext4/super.c b/fs/ext4/super.c
> index 61511b7ba017..a22417d113ca 100644
> --- a/fs/ext4/super.c
> +++ b/fs/ext4/super.c
> @@ -1277,7 +1277,7 @@ static void ext4_put_super(struct super_block *sb)
>  
>  	sync_blockdev(sb->s_bdev);
>  	invalidate_bdev(sb->s_bdev);
> -	if (sbi->s_journal_bdev && sbi->s_journal_bdev != sb->s_bdev) {
> +	if (sbi->s_journal_bdev) {
>  		sync_blockdev(sbi->s_journal_bdev);
>  		ext4_blkdev_remove(sbi);
>  	}
> -- 
> 2.31.1
> 
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR