From: Tomasz Chmielewski <tch@virtall.com>
To: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Cc: "linux-btrfs@vger.kernel.org" <linux-btrfs@vger.kernel.org>
Subject: Re: btrfs qgroup destroy -> ERROR: unable to create quota group: Device or resource busy
Date: Fri, 9 Aug 2013 14:07:50 +0800 [thread overview]
Message-ID: <20130809140750.59832bc4@virtall.com> (raw)
In-Reply-To: <52048483.1010809@cn.fujitsu.com>
On Fri, 09 Aug 2013 13:56:19 +0800
Wang Shilong <wangsl.fnst@cn.fujitsu.com> wrote:
> > 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.
Great to hear (using 3.11-rc4 now).
> > 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.
I don't want to remove the parent qgroup, as it's in use by other subvolumes:
# /usr/src/qgroup/btrfs-progs/btrfs qgroup show -c /mnt/lxc1 | grep 4494
0/4494 839516160 18446744073709481984 --- <------ want to remove only this one
13/1 2142674944 2142674944 0/3973,0/3974,0/3978,0/3981,0/4355,0/4373,0/4398,0/4400,0/4401,0/4427,0/4448,0/4449,0/4457,0/4458,0/4475,0/4476,0/4487,0/4488,0/4489,0/4490,0/4491,0/4492,0/4493,0/4494,0/4495,0/4496,0/4497,0/4498,0/4499,0/4506,0/4507,0/4518
Parent qgroup 13/1 makes accounting for other qgroups - therefore, I don't want to remove it.
BTW, "/usr/src/qgroup/btrfs-progs/btrfs" is from http://github.com/miaoxie/btrfs-progs.git, to support printing parent/child qgroup IDs.
Note it shows different values than btrfs from official repository - is that expected?
# /usr/src/qgroup/btrfs-progs/btrfs qgroup show /mnt/lxc1 | grep 4494
0/4494 839516160 18446744073709481984
# btrfs qgroup show /mnt/lxc1 | grep 4494
0/4494 839516160 -69632
--
Tomasz Chmielewski
http://wpkg.org
next prev parent reply other threads:[~2013-08-09 6:07 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-08-09 5:39 btrfs qgroup destroy -> ERROR: unable to create quota group: Device or resource busy Tomasz Chmielewski
2013-08-09 5:56 ` Wang Shilong
2013-08-09 6:07 ` Tomasz Chmielewski [this message]
2013-08-09 6:08 ` Wang Shilong
2013-08-09 6:42 ` Tomasz Chmielewski
2013-08-09 6:56 ` Wang Shilong
2013-08-09 7:47 ` Tomasz Chmielewski
2013-08-09 12:47 ` Wang Shilong
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