From: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Date: Tue, 11 Nov 2014 12:18:22 +0000 (-0500)
Subject: btrfs: qgroup: return EINVAL if level of parent is not higher than child's.
X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=09870d2772b284d0061a5e4d1e1cdf6fb6764344;p=openwrt%2Fstaging%2Fblogic.git

btrfs: qgroup: return EINVAL if level of parent is not higher than child's.

When we create a subvol inheriting a qgroup, we need to check the level
of them. Otherwise, there is a chance a qgroup can inherit another qgroup
at the same level.

Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
---

diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
index 17881ad8ed96..4ec86b3eee21 100644
--- a/fs/btrfs/qgroup.c
+++ b/fs/btrfs/qgroup.c
@@ -2230,6 +2230,11 @@ int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans,
 				ret = -EINVAL;
 				goto out;
 			}
+
+			if ((srcgroup->qgroupid >> 48) <= (objectid >> 48)) {
+				ret = -EINVAL;
+				goto out;
+			}
 			++i_qgroups;
 		}
 	}