[Ocfs2-devel] [RFC] Online File(system) check

[Junxiao Bi <junxiao.bi@oracle.com>]

On 05/02/2015 08:45 PM, Goldwyn Rodrigues wrote:
> 
> 
> On 04/29/2015 02:59 AM, Junxiao Bi wrote:
>> On 04/28/2015 05:32 AM, Goldwyn Rodrigues wrote:
>>> On popular demand, here is an RFC. If you think there is a better
>>> way to communicate with the kernel module for the check, please
>>> let me know.
>>>
>>>
>>> Intro
>>> -----
>>> OCFS2 is often used in high-availaibility systems. However, ocfs2
>>> converts the filesystem to read-only at the drop of the hat. This
>>> may not be necessary, since turning the filesystem read-only would
>>> affect other running processes as well, decreasing availability.
>>>
>>> This attempt is to add errors=continue, which would return the EIO
>>> to the calling process and terminate furhter processing so that
>>> the filesystem is not corrupted further. However, the filesystem
>>> is not converted to read-only.
>> Is this safe, if detected an error when accessing an inode, how do you
>> know this is only inode internal error?
> 
> 
> Thanks for your comments. The error message would need to be modified to
> specify the inode(s) which need to be checked. It could be a regular
> file or the system inode.
> 
>> If there is corruptions in other
>> place, the fs will be corrupted further.
>>
> It there is a corruption in another place, the process will err at that
> location.
> 
> Could you provide a sample case to explain this situation? and how is it
> different from what is already present in the code?

For example, if a disk had some bit reversion error, some used bits in
local alloc are marked free and also an inode X's inline flag is
cleared, set fs read-only when detected the inode error at the first
time will stop more data corruption.

I think if want to continue for some inconsistent, we need to prove it's
safe, if can't then better stop at first time.

Thanks,
Junxiao.

>