Btrfs: fix missing check before disabling quota

The original code forget to check whether quota has been disabled firstly,
and it will return 'EINVAL' and return error to users if quota has been
disabled,it will be unfriendly and confusing for users to see that.
So just return directly if quota has been disabled.

Signed-off-by: Wang Shilong <wangsl-fnst@cn.fujitsu.com>
Cc: Arne Jansen <sensille@gmx.net>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
index a0d6368249fa3b07f903d445194bccc5f0def879..88ab785bbd73181e64843d97838799619e1c140e 100644 (file)
--- a/fs/btrfs/qgroup.c
+++ b/fs/btrfs/qgroup.c
@@ -847,6 +847,10 @@ int btrfs_quota_disable(struct btrfs_trans_handle *trans,
        int ret = 0;
 
        spin_lock(&fs_info->qgroup_lock);
+       if (!fs_info->quota_root) {
+               spin_unlock(&fs_info->qgroup_lock);
+               return 0;
+       }
        fs_info->quota_enabled = 0;
        fs_info->pending_quota_state = 0;
        quota_root = fs_info->quota_root;