Btrfs: prevent qgroup destroy when there are still relations

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>
This commit is contained in:
Arne Jansen 2013-01-17 01:22:09 -07:00 committed by Chris Mason
parent ff24858c65
commit 2cf6870396

View file

@ -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;