[Ocfs2-devel] [PATCH 1/1] Ocfs2: __ocfs2_find_path() needs to treat hole correctly.

[tristan <tristan.ye@oracle.com>]

Tao Ma wrote:
>
>
> tristan wrote:
>> Tao Ma wrote:
>>> Tristan Ye wrote:
>>>> Currently, __ocfs2_find_path() was lack of a mechanism to detect
>>>> a hole between two extent blocks if the cpos we want to search is
>>>> within the hole, as a result, the last rec will be returned 
>>>> incorrectly.
>>>>   
>>> Do you mean extent block or extent rec? The extent block are 
>>> contiguous and there should be no hole.
>>> oh, here. We should never meet with this. So Nack.
>>
>> I meant the extent records in none-leaf extent blocks, may the hole 
>> exist between these recs?
> no, there is no holes except the leaf extent rec.

Gotcha,

Thanks for teaching;) I thought there may be a bug along with my 
punching hole patch, seems that is fine...

>
> Regards,
> Tao
>>
>>
>> Tristan.
>>
>>
>>>
>>> Regards,
>>> Tao
>>>>   This patch attempts to detect a hole, and return the rightmost
>>>> extent block preceding the hole.
>>>>
>>>> Signed-off-by: Tristan Ye <tristan.ye@oracle.com>
>>>> ---
>>>>  fs/ocfs2/alloc.c |   11 +++++++++++
>>>>  1 files changed, 11 insertions(+), 0 deletions(-)
>>>>
>>>> diff --git a/fs/ocfs2/alloc.c b/fs/ocfs2/alloc.c
>>>> index 9f8bd91..2638a18 100644
>>>> --- a/fs/ocfs2/alloc.c
>>>> +++ b/fs/ocfs2/alloc.c
>>>> @@ -1841,6 +1841,17 @@ static int __ocfs2_find_path(struct 
>>>> ocfs2_caching_info *ci,
>>>>                  ocfs2_rec_clusters(el, rec);
>>>>              if (cpos >= le32_to_cpu(rec->e_cpos) && cpos < range)
>>>>                  break;
>>>> +
>>>> +            /*
>>>> +             * Return the rightmost extent block leftly adjacent
>>>> +             * to a hole if there is any between two extent blocks.
>>>> +             *
>>>> +             * Otherwise, we get the last rec of this block 
>>>> unexpectly.
>>>> +             */
>>>> +            if (cpos < le32_to_cpu(rec->e_cpos)) {
>>>> +                i--;
>>>> +                break;
>>>> +            }
>>>>          }
>>>>  
>>>>          blkno = le64_to_cpu(el->l_recs[i].e_blkno);
>>>>   
>>>
>>