Re: migrating to space_cache=2 and btrfs userspace commands

[DanglingPointer <danglingpointerexception@gmail.com>]

Yep that's what I'm referring to here: 
https://btrfs.wiki.kernel.org/index.php/Manpage/btrfs(5)

Thanks for the prompt respone Qu!

So just to confirm, our scheduled cron jobs to scrub will still work 
with space_cache=v2?



On 14/7/21 4:05 pm, Qu Wenruo wrote:
>
>
> On 2021/7/14 下午1:44, Chris Murphy wrote:
>> On Tue, Jul 13, 2021 at 10:59 PM Qu Wenruo <quwenruo.btrfs@gmx.com> 
>> wrote:
>>>
>>>
>>>
>>> On 2021/7/13 下午11:38, DanglingPointer wrote:
>>
>>>> 2. If we use space_cache=v2, is it indeed still the case that the
>>>>      "btrfs" command will NOT work with the filesystem?
>>>
>>> Why would you think "btrfs" won't work on a btrfs?
>>>
>>
>> Maybe this?
>>
>> man 5 btrfs, space_cache includes:
>>
>>   The btrfs(8) command currently only has read-only support for v2. A
>> read-write command may be run on a v2 filesystem by clearing the
>> cache, running the command, and then remounting with space_cache=v2.
>>
>
> Oh, that's only for offline tools writing into the fs, namingly "btrfs
> check --repair" and "mkfs.btrfs -R"
>
> And I believe that sentence is now out-of-date after btrfs-progs v4.19,
> which pulls all the support for write time free space tree (v2 space 
> cache).
>
> I'll soon send out a patch to fix that.
>
> Thanks,
> Qu