7378 exported_lock held during nfs4 compound processing

@@ -637,11 +637,12 @@
                          * Check if this exportroot is a VROOT dir.  If so,
                          * then attach the pseudonodes.  If not, then
                          * continue .. traversal until we hit a VROOT
                          * export (pseudo or real).
                          */
-                        exi = checkexport4(&vp->v_vfsp->vfs_fsid, &fid, vp);
+                        exi = checkexport_nohold(&vp->v_vfsp->vfs_fsid, &fid,
+                            vp);
                         if (exi != NULL && vp->v_flag & VROOT) {
                                 /*
                                  * Found an export info
                                  *
                                  * Extend the list of visible