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Date:   Mon, 19 Oct 2020 20:59:30 -0700
From:   "Darrick J. Wong" <darrick.wong@oracle.com>
To:     Luo Meng <luomeng12@huawei.com>
Cc:     tytso@mit.edu, adilger.kernel@dilger.ca,
        linux-ext4@vger.kernel.org, jack@suse.cz
Subject: Re: [PATCH] ext4: fix invalid inode checksum
Message-ID: <20201020035930.GA489993@magnolia>
References: <20201020013631.3796673-1-luomeng12@huawei.com>
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In-Reply-To: <20201020013631.3796673-1-luomeng12@huawei.com>
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On Tue, Oct 20, 2020 at 09:36:31AM +0800, Luo Meng wrote:
> During the stability test, there are some errors:
>   ext4_lookup:1590: inode #6967: comm fsstress: iget: checksum invalid.
> 
> If the inode->i_iblocks too big and doesn't set huge file flag, checksum
> will not be recalculated when update the inode information to it's buffer.
> If other inode marks the buffer dirty, then the inconsistent inode will
> be flushed to disk.
> 
> Fix this problem by checking i_blocks in advance.
> 
> Signed-off-by: Luo Meng <luomeng12@huawei.com>

Fun!  Yikes!
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>

--D

> ---
>  fs/ext4/inode.c | 11 ++++++-----
>  1 file changed, 6 insertions(+), 5 deletions(-)
> 
> diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
> index bf596467c234..fe53774b8b6c 100644
> --- a/fs/ext4/inode.c
> +++ b/fs/ext4/inode.c
> @@ -4971,6 +4971,12 @@ static int ext4_do_update_inode(handle_t *handle,
>  	if (ext4_test_inode_state(inode, EXT4_STATE_NEW))
>  		memset(raw_inode, 0, EXT4_SB(inode->i_sb)->s_inode_size);
>  
> +	err = ext4_inode_blocks_set(handle, raw_inode, ei);
> +	if (err) {
> +		spin_unlock(&ei->i_raw_lock);
> +		goto out_brelse;
> +	}
> +
>  	raw_inode->i_mode = cpu_to_le16(inode->i_mode);
>  	i_uid = i_uid_read(inode);
>  	i_gid = i_gid_read(inode);
> @@ -5004,11 +5010,6 @@ static int ext4_do_update_inode(handle_t *handle,
>  	EXT4_INODE_SET_XTIME(i_atime, inode, raw_inode);
>  	EXT4_EINODE_SET_XTIME(i_crtime, ei, raw_inode);
>  
> -	err = ext4_inode_blocks_set(handle, raw_inode, ei);
> -	if (err) {
> -		spin_unlock(&ei->i_raw_lock);
> -		goto out_brelse;
> -	}
>  	raw_inode->i_dtime = cpu_to_le32(ei->i_dtime);
>  	raw_inode->i_flags = cpu_to_le32(ei->i_flags & 0xFFFFFFFF);
>  	if (likely(!test_opt2(inode->i_sb, HURD_COMPAT)))
> -- 
> 2.25.4
>