1 files changed, 19 insertions, 1 deletions

diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
index fe9d02c45f8e..a5c856234323 100644
--- a/fs/btrfs/qgroup.c
+++ b/fs/btrfs/qgroup.c
@@ -379,6 +379,13 @@ next1:
 
                 ret = add_relation_rb(fs_info, found_key.objectid,
                                       found_key.offset);
+                if (ret == -ENOENT) {
+                        printk(KERN_WARNING
+                                "btrfs: orphan qgroup relation 0x%llx->0x%llx\n",
+                                (unsigned long long)found_key.objectid,
+                                (unsigned long long)found_key.offset);
+                        ret = 0;        /* ignore the error */
+                }
                 if (ret)
                         goto out;
 next2:
@@ -956,17 +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;