Hello Qu,

On 18.05.22 at 12:59 Qu Wenruo wrote:
> On 2022/5/18 18:38, Johannes Kastl wrote:
>> Fixing the device size fails nonetheless (see below). And I can no
>> longer mount the filesystem, when I try I find this in the logs:
>>
>>> [87396.889043] BTRFS error (device sdb1): super_total_bytes
>>> 15393162784768 mismatch with fs_devices total_rw_bytes 15393162788864
>>> [87396.889974] BTRFS error (device sdb1): failed to read chunk tree: -22
>>> [87396.892741] BTRFS error (device sdb1): open_ctree failed
>>
>> (Don't get confused by sdb1, this is from a rescue system with only some
>> HDDs attached)
>>
>> Fixing the device-size on Leap 15.3:
>>> # btrfs filesystem show /mnt/DUMBO_BACKUP_4TB/
>>> Label: 'DUMBO_BACKUP_4TB'  uuid: 50651b41-bf33-47e7-8a08-afbc71ba0bf8
>>>         Total devices 2 FS bytes used 3.17TiB
>>>         devid    1 size 7.00TiB used 3.64TiB path /dev/sdd1
>>>         devid    2 size 7.00TiB used 3.63TiB path /dev/sdc1
> 
> That's super weird, we have tons of unallocated space.
> 
> So definitely something wrong in btrfs-progs.
> Normally `btrfs fi usage` would provide more info, but it needs the fs
> to be mountable.
> 
> Can you prepare a building environment for btrfs-progs?
> 
> I can update the code to skip transaction commit so that we won't be
> bother with -ENOSPC at all.
> 
> And since we're not really doing any metadata update, we don't really
> need any new space.
> 
> And after your building environment prepared, you can fetch this branch
> to compile the btrfs-progs and try to use the compiled `btrfs` command
> to rescue the device again.

Thanks for your help!

> https://github.com/adam900710/btrfs-progs/tree/dirty_fix
> 
> I did some local tests, it shows no problem, but not sure if it would
> work for you.

I am trying to build this and will test it, hopefully tomorrow. I'll let you 
know what happens...

Kind Regards,
Johannes

-- 
Johannes Kastl
Linux Consultant & Trainer
Tel.: +49 (0) 151 2372 5802
Mail: kastl@b1-systems.de

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