Btrfs: prevent qgroup destroy when there are still relations (2cf68703) · Commits · 戴 / test

Currently you can just destroy a qgroup even though it is in use by other qgroups or has qgroups assigned to it. This patch prevents destruction of qgroups unless they are completely unused. Otherwise destroy will return EBUSY. Reported-by:

Eric Hopper <hopper@omnifarious.org> Signed-off-by:

Arne Jansen <sensille@gmx.net> Signed-off-by:

Chris Mason <chris.mason@fusionio.com>

fs/btrfs/qgroup.c

+12 −1

Original line number	Diff line number	Diff line
		@@ -963,17 +963,28 @@ int btrfs_remove_qgroup(struct btrfs_trans_handle *trans,
		struct btrfs_fs_info *fs_info, u64 qgroupid)
		{
		struct btrfs_root *quota_root;
		struct btrfs_qgroup *qgroup;
		int ret = 0;

		quota_root = fs_info->quota_root;
		if (!quota_root)
		return -EINVAL;

		/* check if there are no relations to this qgroup */
		spin_lock(&fs_info->qgroup_lock);
		qgroup = find_qgroup_rb(fs_info, qgroupid);
		if (qgroup) {
		if (!list_empty(&qgroup->groups) \|\| !list_empty(&qgroup->members)) {
		spin_unlock(&fs_info->qgroup_lock);
		return -EBUSY;
		}
		}
		spin_unlock(&fs_info->qgroup_lock);

		ret = del_qgroup_item(trans, quota_root, qgroupid);

		spin_lock(&fs_info->qgroup_lock);
		del_qgroup_rb(quota_root->fs_info, qgroupid);

		spin_unlock(&fs_info->qgroup_lock);

		return ret;

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