On 2018/11/7 下午3:04, Su Yanjun <suyj.f...@cn.fujitsu.com> wrote:
>
>
> On 11/7/2018 2:38 PM, Qu Wenruo wrote:
>>
>> On 2018/11/7 下午2:21, Su Yanjun <suyj.f...@cn.fujitsu.com> wrote:
>>>
>>> On 10/24/2018 8:45 AM, Qu Wenruo wrote:
>>>> On 2018/10/23 下午5:41, Su Yue wrote:
>>>>> From: Su Yanjun <suyj.f...@cn.fujitsu.com>
>>>>>
>>>>> In original mode, if some file extent item has unaligned extent
>>>>> backref,
>>>>> fixup_extent_refs can't repair it. This patch will check extent
>>>>> alignment
>>>>> then delete file extent with unaligned extent backref.
>>>> This looks a little strange to me.
>>>>
>>>> You mean, an unaligned FILE EXTENT has an unaligned EXTENT_ITEM?
>>>>
>>>> Then why not just delete the EXTENT_ITEM directly? No need to go back
>>>> checking if it has a corresponding EXTENT_DATA since unaligned one is
>>>> definitely corrupted.
>>>>
>>>> For corrupted EXTENT_DATA, it should get deleted when we check fs tree.
>>>>
>>>> This would save you a lot of codes.
>>>>
>>>> Thanks,
>>>> Qu
>>> The situation is that the file extent has wrong extent backref, actually
>>> it doesn't exist.
>> Did you mean extent EXTENT_ITEM key's objectid is unaligned?
>>
>> Would you please give an example on this case? Like:
>> (<ino> EXTENT_DATA <offset>
>> disk bytenr <XXXX> disk len <YYYY>
>>
>> And its backref like:
>> (<XXXX> EXTENT_ITEM <YYYY>)
>>
>> And then mark where the number is incorrect.
>>
>> Thanks,
>> Qu
>
> As in /btrfs-progs/tests/fsck-tests/001-bad-file-extent-bytenr case:
>
> item 7 key (257 EXTENT_DATA 0) itemoff 3453 itemsize 53
>
> generation 6 type 1 (regular)
>
> extent data disk byte 755944791 nr 1048576
> ^^^^^^^^^
>
> extent data offset 0 nr 1048576 ram 1048576
>
> extent compression 0 (none)
Then there is no "unaligned extent backref".
It's just a unaligned disk bytenr of a file extent.
Nothing to do with backref.
Please update the commit message to avoid such confusing words, and
include above info, which is pretty easy to understand.
Thanks,
Qu
>
> Thanks,
>
> Su
>
>>> Thanks,
>>> Su
>>>
>>>
>>>
>>>
>>>
>>
>
>
>
