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 17881ad8..4ec86b3 100644
--- a/fs/btrfs/qgroup.c
+++ b/fs/btrfs/qgroup.c
@@ -2230,6 +2230,11 @@
ret = -EINVAL;
goto out;
}
+
+ if ((srcgroup->qgroupid >> 48) <= (objectid >> 48)) {
+ ret = -EINVAL;
+ goto out;
+ }
++i_qgroups;
}
}