Btrfs: fix double free in the btrfs_qgroup_account_ref()

The function btrfs_find_all_roots is responsible to allocate
memory for 'roots' and free it if errors happen,so the caller should not
free it again since the work has been done.

Besides,'tmp' is allocated after the function btrfs_find_all_roots,
so we can return directly if btrfs_find_all_roots() fails.

Signed-off-by: Wang Shilong <wangsl-fnst@cn.fujitsu.com>
Reviewed-by: Miao Xie <miaox@cn.fujitsu.com>
Reviewed-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
index 5471e47d6559eafeb36e55035cb427710c5ee4ba..b44124dd2370ea726e66a099400163c342d8fa12 100644 (file)
--- a/fs/btrfs/qgroup.c
+++ b/fs/btrfs/qgroup.c
@@ -1153,7 +1153,7 @@ int btrfs_qgroup_account_ref(struct btrfs_trans_handle *trans,
        ret = btrfs_find_all_roots(trans, fs_info, node->bytenr,
                                   sgn > 0 ? node->seq - 1 : node->seq, &roots);
        if (ret < 0)
-               goto out;
+               return ret;
 
        spin_lock(&fs_info->qgroup_lock);
        quota_root = fs_info->quota_root;
@@ -1275,7 +1275,6 @@ int btrfs_qgroup_account_ref(struct btrfs_trans_handle *trans,
        ret = 0;
 unlock:
        spin_unlock(&fs_info->qgroup_lock);
-out:
        ulist_free(roots);
        ulist_free(tmp);