[Ocfs2-devel] [PATCH] ocfs2: fix panic due to unrecovered local alloc

[Junxiao Bi]

Hi Yiwen

On 11/19/18 10:17 AM, jiangyiwen wrote:
> Hi Junxiao,
>
> I think this scenario may be as follows:
>
> ocfs2_dismount_volume()
>    - ocfs2_shutdown_local_alloc()
>      1. clear local alloc and commit transaction

For jbd2, not commit yet, it could be still in running transaction, that 
means it was not written into journal yet.

Later when flushing the running transaction to journal, io error may 
happen, this running transaction not only contained local alloc changes 
but also other metadata. How recovering local alloc only can avoid other 
metadata corruption?

>      2. storage disconnection cause data don't update to disk and journal abort.
>    - ocfs2_journal_shutdown()
>      3. in this function, it will call ocfs2_journal_toggle_dirty() to
>         clear dirty even if journal abort.

Check rerturn value of jbd2_journal_destroy() seemed OK to judge whether 
toggle dirty flag.


Thanks,

Junxiao.

>
> So I suggest we can do two aspects:
> 1. Actively recover local alloc when checking journal clean and "local_alloc dirty"
> in ocfs2_check_volume(), instead of fsck, it can online recover this case more
> intelligently.
> 2. Before calling ocfs2_journal_toggle_dirty(), check if journal abort.
>
> Thanks,
> Yiwen.
>