[Ocfs2-devel] [PATCH v2] ocfs2: should not use le32_add_cpu to set ocfs2_dinode i_flags

[Jeff Liu]

Hi Andrew,

Sorry for the late response because I just returned from the LinuxCon/Japan.

I'm afraid that Joesph can not follow this thread up in time since today is the
weekend in China.  So please let me answer your question on behalf of Joesph
as a quick response.

On 06/01/2013 06:25 AM, Andrew Morton wrote:

> On Thu, 30 May 2013 12:49:46 +0800 Joseph Qi <joseph.qi at huawei.com> wrote:
> 
>> If we use le32_add_cpu to set ocfs2_dinode i_flags, it may lead to the
>> corresponding flag corrupted. So we should change it to bitwise and/or
>> operation.
>>
> 
> The usual question: what is the end-user impact of the bug which was
> just fixed?

This patch can be treated as a trivial fix.  Yes, i_flags is operated in
bitwise context, but those assignments are only happened at the time of
initializing the corresponding OCFS2 private on-disk inode info.  Hence
there is no impact from the end-user's perspective.

However, it's better to replace those three assignments with bitwise operations
since they essentially should be.  In this way, we can immediately know that the
business performed on i_flags are in bitwise rather than increasing or decreasing
a count value. 

> For the usual reason: so I and others can decide which kernel versions
> need the fix.

The current fix comments looks too horrible than it would be.
Can it make your life easier if I repost this patch with the revised
descriptions if Joseph agrees to me?


Thanks,
-Jeff