Re: [PATCH 1/2] btrfs-progs: check: add check and repair ability for super num devs mismatch

[Qu Wenruo <quwenruo.btrfs@gmx.com>]

On 2022/3/24 07:15, Qu Wenruo wrote:
>
>
> On 2022/3/24 01:43, David Sterba wrote:
>> On Mon, Feb 28, 2022 at 08:50:07AM +0800, Qu Wenruo wrote:
>>> [BUG]
>>> There is a bug report of kernel rejecting fs which has a mismatch in
>>> super num devices and num devices found in chunk tree.
>>>
>>> But btrfs-check reports no problem about the fs.
>>>
>>> [CAUSE]
>>> We just didn't verify super num devices against the result found in
>>> chunk tree.
>>>
>>> [FIX]
>>> Add such check and repair ability for btrfs-check.
>>>
>>> The ability is mode independent.
>>>
>>> Reported-by: Luca Béla Palkovics <luca.bela.palkovics@gmail.com>
>>> Link:
>>> https://lore.kernel.org/linux-btrfs/CA+8xDSpvdm_U0QLBAnrH=zqDq_cWCOH5TiV46CKmp3igr44okQ@mail.gmail.com/
>>>
>>> Signed-off-by: Qu Wenruo <wqu@suse.com>
>>
>> With this patch applied there's a new test failure:
>>
>> === START TEST .../tests/fsck-tests/014-no-extent-info
>> testing image no_extent.raw.restored
>> ====== RUN MUSTFAIL .../btrfs check ./no_extent.raw.restored
>> Opening filesystem to check...
>> Checking filesystem on ./no_extent.raw.restored
>> UUID: aeee7297-37a4-4547-a8a9-7b870d58d31f
>> cache and super generation don't match, space cache will be invalidated
>> found 180224 bytes used, no error found
>> total csum bytes: 0
>> total tree bytes: 180224
>> total fs tree bytes: 81920
>> total extent tree bytes: 16384
>> btree space waste bytes: 138540
>> file data blocks allocated: 0
>>   referenced 0
>> succeeded (unexpected!): .../btrfs check ./no_extent.raw.restored
>> unexpected success: btrfs check should have detected corruption
>
>
> Weird, the problem is, for the restored image, if I run ./btrfs check
> manually it can detects the problem, but still go "no error found" path.
>
> So it must be my patch overriding the return value.

Indeed that's the case.

Fix upon current devel branch is:
https://lore.kernel.org/linux-btrfs/f576d7a548b91d42d02b17d2dc52ee04d943a57d.1648077794.git.wqu@suse.com/T/#u

Please fold the fix into the patch.

Thanks,
Qu
>
> Will fix it soon.
>
> Thanks,
> Qu