How to use gvfs to unmount someone's gvfs mounted shared folder with root or sudo user.

["minqiang wu" <minqiang wu gmail com>]

The request is as follows:

On the destkop of use "abc", we use gvfs-mount to mount some shared folder with smb. 
The links are displayed on the user abc's desktop. 

Then we need to unmount all these shared folders, but our applicaiton has to run with root privilage now. 
Our application run with sudo, or just as "root" user. 
Then how we can umount the mounted smb shared folder on "abc" 's desktop. 
We tried to use gvfs-mount as  "sudo -u abc gvfs-mount -u smb://xxx/test", but the gvfs-mount just report errors. 

Is there any solution to this case?


Thanks
Minqiang