As promised, this post describes how to root the Droid Bionic Jelly Bean build. It should also work on the XT910 Jelly Bean build, but this hasn't been tested yet. Fortunately for Bionic and XT910 owners, I was able to modify Motoshare, which was originally created for the Atrix HD, to work for these devices. My plans to stop looking for new Motorola exploits have not changed at this time, so don't read into this too much.
The exploit requires setting up a special Samba share and mounting this share on your phone using the Files app.
read more.......http://www.droidrzr.com/index.php/topic/16518-root-motoshare-2-old-bug-new-exploit/