vfsmount mnt_parent element change

I'm trying to find out the changes in the kernel relating the 3.2 to 3.3 changes in relation to the vfsmount structure change as we use an application that uses the mnt_parent element that no longer exists in the source. I looked at the Documentation directory for the kernel in Fedora 16 but it has references to mnt_parent still (linux-3.3.7/Documentation/filesystems). I saw a bug reference that has this being moved to the mount structure however I don't get any results with grep on the entire source tree for mnt_parent. Can anyone point me to a document that has the structure change so that I can modify this source accordingly? Thanks