Re: btrfs qgroup destroy -> ERROR: unable to create quota group: Device or resource busy

[Wang Shilong <wangsl.fnst@cn.fujitsu.com>]

Hello,

On 08/09/2013 01:39 PM, Tomasz Chmielewski wrote:
> I'm using qgroups and have created a few hundreds of subvolumes in the
> past.
> 
> It seems that btrfs automatically assigns a qgroup to newly created
> snapshot/subvolume, but does not destroy the qgroup when the subvolume
> is deleted.

This should be implemented. And will soon.

> 
> So I've tried to destroy the unused qgroups, with mixed success. I was
> able to destroy most of them, but some are still failing, i.e.:
> 
> # btrfs qgroup destroy 4494 /mnt/lxc1
> ERROR: unable to create quota group: Device or resource busy

Just remove qgroup（4494）'s parent qgroup. then it can be removed.
Anyway, i think this is unnecessary.

Thanks,
Wang
> 
> 
> Note the negative number here, but I also have qgroups with both
> positive numbers, which I'm not able to destroy as well:
> 
> # btrfs qgroup show /mnt/lxc1 | grep 4494
> 0/4494 839516160 -69632
> 
> 
> qgroup 4494 is not used by any subvolume:
> 
> # btrfs sub list /mnt/lxc1 | grep 4494
> 
> 
> I did run "btrfs quota rescan" for this filesystem, hoping it will fix
> the problem, but it didn't.
> 
> 
> Any advice?
> 
>