[Ocfs2-tools-devel] [PATCH 2/2] looped chain - Break loop in fsck

[Sunil Mushran]

tristan wrote:
> Sunil Mushran wrote:
>> Let me also add my 2 cents worth.
>>
>> For the global bitmap, why don't we compute the list of expected values
>> and check against that. That will be a lot more precise. This check can
>> be added in CHAIN_LINK_RANGE.
>
> Sorry, here I didn't quite understand your suggestion well, are we 
> going to validate the starting blkno of each cluster group in 
> CHAIN_LINK_RANGE? then correct them by our calculation if any mismatch 
> happened? if it's the case, it looks like s a strengthening to 
> CHAIN_LINK_RANGE?  may that need a new prompt code in this case?
>
> Or we're going to take this into account in CHAIN_LOOP case? that 
> means, we can break the loop by pointing to a correct blkno we 
> calculated, instead of  terminating it as NULL.
>
> Could you please explain more about the motivation?

I am talking about only the global bitmap. The one attribute
the our cluster bitmap has that the blocknumbers in each chain
group can be computed. We won't know the order. But we know
the list of values to expect. The order is unknown because we keep
reordering it.

So instead of looking for only a loop, we can cast a wider net by
also ensuring the value is one of expected.

Having said that, the reality is that the loop will probably be our
biggest problem.

This is just a thought. Joel thinks we should be already doing that
check. If so, then ignore my mutterings.

BTW, maybe more in line if it is called CHAIN_LINK_LOOP.

Sunil