Land fix for bug 1558 on HEAD. r=phil,shaver

lustre/ldlm/ldlm_lock.c

@@ -153,6 +153,8 @@ void ldlm_lock_put(struct ldlm_lock *lock)
 
                 ldlm_resource_putref(lock->l_resource);
                 lock->l_resource = NULL;
+                if (lock->l_export)
+                        class_export_put(lock->l_export);
 
                 if (lock->l_parent)
                         LDLM_LOCK_PUT(lock->l_parent);
@@ -220,6 +222,8 @@ void ldlm_lock_destroy(struct ldlm_lock *lock)
         /* Wake anyone waiting for this lock */
         /* FIXME: I should probably add yet another flag, instead of using
          * l_export to only call this on clients */
+        if (lock->l_export)
+                class_export_put(lock->l_export);
         lock->l_export = NULL;
         if (lock->l_export && lock->l_completion_ast)
                 lock->l_completion_ast(lock, 0);

lustre/ldlm/ldlm_lockd.c

@@ -179,8 +179,6 @@ static int ldlm_add_waiting_lock(struct ldlm_lock *lock)
         }
         list_add_tail(&lock->l_pending_chain, &waiting_locks_list); /* FIFO */
         spin_unlock_bh(&waiting_locks_spinlock);
-        /* We drop this ref when we get removed from the list. */
-        class_export_get(lock->l_export);
         return 1;
 }
 
@@ -223,8 +221,6 @@ int ldlm_del_waiting_lock(struct ldlm_lock *lock)
         }
         list_del_init(&lock->l_pending_chain);
         spin_unlock_bh(&waiting_locks_spinlock);
-        /* We got this ref when we were added to the list. */
-        class_export_put(lock->l_export);
         LDLM_DEBUG(lock, "removed");
         return 1;
 }
@@ -468,7 +464,7 @@ int ldlm_handle_enqueue(struct ptlrpc_request *req,
         LDLM_DEBUG(lock, "server-side enqueue handler, new lock created");
 
         LASSERT(req->rq_export);
-        lock->l_export = req->rq_export;
+        lock->l_export = class_export_get(req->rq_export);
         l_lock(&lock->l_resource->lr_namespace->ns_lock);
         list_add(&lock->l_export_chain,
                  &lock->l_export->exp_ldlm_data.led_held_locks);