From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cn.fujitsu.com ([222.73.24.84]:8761 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S966964Ab3HIF5t convert rfc822-to-8bit (ORCPT ); Fri, 9 Aug 2013 01:57:49 -0400 Message-ID: <52048483.1010809@cn.fujitsu.com> Date: Fri, 09 Aug 2013 13:56:19 +0800 From: Wang Shilong MIME-Version: 1.0 To: Tomasz Chmielewski CC: "linux-btrfs@vger.kernel.org" Subject: Re: btrfs qgroup destroy -> ERROR: unable to create quota group: Device or resource busy References: <20130809133933.2fbfc6e4@virtall.com> In-Reply-To: <20130809133933.2fbfc6e4@virtall.com> Content-Type: text/plain; charset=UTF-8 Sender: linux-btrfs-owner@vger.kernel.org List-ID: 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? > >