Btrfs: fix missing check in the btrfs_qgroup_inherit()

The original code forgot to check 'inherit', we should
gurantee that all the qgroups in the struct 'inherit' exist.

Signed-off-by: Wang Shilong <wangsl-fnst@cn.fujitsu.com>
Reviewed-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

1 files changed, 15 insertions, 0 deletions

diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
index 0932b839550c..2293da6f9e72 100644
--- a/fs/btrfs/qgroup.c
+++ b/fs/btrfs/qgroup.c
@@ -1412,6 +1412,7 @@ int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans,
         struct btrfs_qgroup *srcgroup;
         struct btrfs_qgroup *dstgroup;
         u32 level_size = 0;
+        u64 nums;
 
         mutex_lock(&fs_info->qgroup_ioctl_lock);
         if (!fs_info->quota_enabled)
@@ -1422,6 +1423,20 @@ int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans,
                 goto out;
         }
 
+        if (inherit) {
+                i_qgroups = (u64 *)(inherit + 1);
+                nums = inherit->num_qgroups + 2 * inherit->num_ref_copies +
+                       2 * inherit->num_excl_copies;
+                for (i = 0; i < nums; ++i) {
+                        srcgroup = find_qgroup_rb(fs_info, *i_qgroups);
+                        if (!srcgroup) {
+                                ret = -EINVAL;
+                                goto out;
+                        }
+                        ++i_qgroups;
+                }
+        }
+
         /*
          * create a tracking group for the subvol itself
          */