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

[Tao Ma]

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.

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 at 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);
>>>   
>>
>