nfs4: Fix rpc listener thread cancelation

recv on UDP sockets is not interrupted when the socket is closed.
Additionaly, signals do not interrupt kernel threads, that is why
new function interrupt_thread was implemented in order to cancel
listener thread.

headers/os/drivers/KernelExport.h

@@ -138,6 +138,7 @@ extern bool			cancel_timer(timer *t);
 /* kernel threads */
 extern thread_id	spawn_kernel_thread(thread_func function,
 						const char *name, int32 priority, void *arg);
+extern status_t		interrupt_thread(thread_id id);
 
 /* signal functions */
 extern int			send_signal_etc(pid_t thread, uint signal, uint32 flags);

src/add-ons/kernel/file_systems/nfs4/Connection.cpp

@@ -55,7 +55,8 @@ Connection::Connection(const sockaddr_in& addr, Transport proto, bool markers)
 
 Connection::~Connection()
 {
-	kclosesocket(fSock);
+	if (fSock != -1)
+		kclosesocket(fSock);
 	mutex_destroy(&fSockLock);
 }
 
@@ -184,6 +185,9 @@ Connection::_ReceivePacket(void** pbuffer, uint32* psize)
 		result = errno;
 		free(buffer);
 		return result;
+	} else if (size == 0) {
+		free(buffer);
+		return ECONNABORTED;
 	}
 
 	*pbuffer = buffer;
@@ -257,6 +261,15 @@ Connection::Reconnect()
 }
 
 
+void
+Connection::Disconnect()
+{
+	int sock = fSock;
+	fSock = -1;
+	kclosesocket(sock);
+}
+
+
 status_t
 Connection::Init()
 {

src/add-ons/kernel/file_systems/nfs4/Connection.h

@@ -39,6 +39,7 @@ public:
 	inline	status_t			Receive(void** buffer, uint32* size);
 
 			status_t			Reconnect();
+			void				Disconnect();
 
 	static	status_t			Init();
 	static	status_t			CleanUp();

src/add-ons/kernel/file_systems/nfs4/RPCServer.cpp

@@ -86,6 +86,8 @@ Server::Server(Connection* conn, ServerAddress* addr)
 Server::~Server()
 {
 	fThreadCancel = true;
+	fConnection->Disconnect();
+	interrupt_thread(fThread);
 
 	delete fConnection;
 
@@ -157,9 +159,12 @@ status_t
 Server::Repair()
 {
 	fThreadCancel = true;
+	interrupt_thread(fThread);
+
 	status_t result = fConnection->Reconnect();
 	if (result != B_OK)
 		return result;
+
 	wait_for_thread(fThread, &result);
 	return _StartListening();
 }
@@ -197,7 +202,8 @@ Server::_Listener()
 		if (req != NULL) {
 			*req->fReply = reply;
 			req->fEvent.NotifyAll();
-		}
+		} else
+			delete reply;
 	}
 
 	return B_OK;

src/system/kernel/thread.cpp

@@ -3007,6 +3007,20 @@ kill_thread(thread_id id)
 }
 
 
+status_t
+interrupt_thread(thread_id id)
+{
+	Thread* thread = Thread::GetAndLock(id);
+	if (thread == NULL)
+		return B_BAD_THREAD_ID;
+	BReference<Thread> threadReference(thread, true);
+	ThreadLocker threadLocker(thread, true);
+
+	InterruptsSpinLocker schedulerLocker(gSchedulerLock);
+	return thread_interrupt(thread, false);
+}
+
+
 status_t
 send_data(thread_id thread, int32 code, const void *buffer, size_t bufferSize)
 {