MFC r1.89:
MFC r1.89:

 - LK_RETRY means nothing when passed to VOP_LOCK.  Call vn_lock instead.
 - Move the vn_lock of the dvp until after we've unbusied the filesystem
   to avoid a LOR with the mount point lock.
 - In the v_mountedhere while loop we acquire a new instance of giant each
   time through without releasing the first.  This would cause us to leak
   Giant.

Sponsored by:   Isilon Systems, Inc.
Approved by:	re (scottl)

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase