[Ocfs2-devel] [PATCH] ocfs2: fix shift left overflow

[Joseph Qi]

On 2015/7/29 8:40, Andrew Morton wrote:
> On Wed, 29 Jul 2015 08:30:59 +0800 Joseph Qi <joseph.qi at huawei.com> wrote:
> 
>> On 2015/7/29 4:51, Andrew Morton wrote:
>>> On Mon, 27 Jul 2015 11:39:16 +0800 Joseph Qi <joseph.qi at huawei.com> wrote:
>>>
>>>> cluster pos is defined as u32, when calculate corresponding sector it
>>>> should be converted to u64 first, otherwise it may overflow.
>>>
>>> What are the runtime effects of this change?
>>>
>> The issue is when using large volume, for example, 9T volume with 2T already
>> used, frequently create small files with O_DIRECT and the IO is not cluster
>> aligned, it may clear sectors in the wrong place.
> 
> You mean it corrupts the filesystem?
> 
> So this wants to be merged asap and backported as far as possible?
> 
Yes, it only affects kernel 4.0+.

>