Re: Critical error from Tree-checker

[Qu Wenruo <wqu@suse.com>]

在 2024/9/12 21:43, Archange 写道:
> Le 12/09/2024 à 14:23, Qu Wenruo a écrit :
>> 在 2024/9/12 19:34, Archange 写道:
>>> Le 12/09/2024 à 14:01, Qu Wenruo a écrit :
>>>> 在 2024/9/12 19:27, Archange 写道:
>>>>> […]
>>>>>
>>>>> [3/7] checking free space tree
>>>>> there is no free space entry for 0-65536
>>>>> cache appears valid but isn't 0
>>>>
>>>> Then it's totally fine.
>>>>
>>>> For the 0-65536 problem, mind to provide the following dump?
>>>>
>>>> # btrfs ins dump-tree -t fst <device>
>>>>
>>>> I'm afraid since the fs is somewhat old, there may be some corner case
>>>> btrfs-check is not handling properly.
>>>
>>> ERROR: unexpected tree id suffix of 'fst': t
>>
>> My bad, it should be "btrfs ins dump-tree -t free-space <device>".
> 
> The output is too big for an email, so uploaded here:
> 
> https://paste.xinu.at/XtR8/
> 
>> And if possible, also "btrfs ins dump-tree -t extent <device>" just in 
>> case.
> 
> Same thing (even bigger), also output on the terminal and while 
> redirecting to a file was quite different (but maybe that’s more because 
> something changed between the two calls), so here are:
> 
> – the cli run : https://paste.xinu.at/9vs/
> 
> – the file run: https://paste.xinu.at/XpzhbZ/

Thanks a lot.

This indeed shows a very old filesystem, and for a long long time, we no 
longer create any block group at logical bytenr 0, thus it shows an 
corner case that older fs layout doesn't exclude the first 1MiB.

And it's indeed a false alert.

In that case, as long as you still have unallocated space, you can just 
relocate the system chunks:

# btrfs balacne start -s <mnt>

Which should move the system chunks to new locations and will not 
utilize the first 1MiB reserved space.

Thanks,
Qu
> 
> Regards,
> Archange
>