Merge branch 'rxrpc-fixes'

David Howells says:

====================
rxrpc: Fixes

Here is a collection of fixes for rxrpc:

 (1) rxrpc_error_report() needs to call sock_error() to clear the error
     code from the UDP transport socket, lest it be unexpectedly revisited
     on the next kernel_sendmsg() call.  This has been causing all sorts of
     weird effects in AFS as the effects have typically been felt by the
     wrong RxRPC call.

 (2) Allow a kernel user of AF_RXRPC to easily detect if an rxrpc call has
     completed.

 (3) Allow errors incurred by attempting to transmit data through the UDP
     socket to get back up the stack to AFS.

 (4) Make AFS use (2) to abort the synchronous-mode call waiting loop if
     the rxrpc-level call completed.

 (5) Add a missing tracepoint case for tracing abort reception.

 (6) Fix detection and handling of out-of-order ACKs.

====================

Tested-by: Jonathan Billings <jsbillin@umich.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>

9 files changed, 75 insertions, 39 deletions

diff --git a/Documentation/networking/rxrpc.txt b/Documentation/networking/rxrpc.txt
index 2df5894353d6..cd7303d7fa25 100644
--- a/Documentation/networking/rxrpc.txt
+++ b/Documentation/networking/rxrpc.txt
@@ -1009,16 +1009,18 @@ The kernel interface functions are as follows:
 
  (*) Check call still alive.
 
-	u32 rxrpc_kernel_check_life(struct socket *sock,
-				    struct rxrpc_call *call);
+	bool rxrpc_kernel_check_life(struct socket *sock,
+				     struct rxrpc_call *call,
+				     u32 *_life);
 	void rxrpc_kernel_probe_life(struct socket *sock,
 				     struct rxrpc_call *call);
 
-     The first function returns a number that is updated when ACKs are received
-     from the peer (notably including PING RESPONSE ACKs which we can elicit by
-     sending PING ACKs to see if the call still exists on the server).  The
-     caller should compare the numbers of two calls to see if the call is still
-     alive after waiting for a suitable interval.
+     The first function passes back in *_life a number that is updated when
+     ACKs are received from the peer (notably including PING RESPONSE ACKs
+     which we can elicit by sending PING ACKs to see if the call still exists
+     on the server).  The caller should compare the numbers of two calls to see
+     if the call is still alive after waiting for a suitable interval.  It also
+     returns true as long as the call hasn't yet reached the completed state.
 
      This allows the caller to work out if the server is still contactable and
      if the call is still alive on the server while waiting for the server to
diff --git a/fs/afs/rxrpc.c b/fs/afs/rxrpc.c
index 2c588f9bbbda..c14001b42d20 100644
--- a/fs/afs/rxrpc.c
+++ b/fs/afs/rxrpc.c
@@ -610,6 +610,7 @@ static long afs_wait_for_call_to_complete(struct afs_call *call,
 	bool stalled = false;
 	u64 rtt;
 	u32 life, last_life;
+	bool rxrpc_complete = false;
 
 	DECLARE_WAITQUEUE(myself, current);
 
@@ -621,7 +622,7 @@ static long afs_wait_for_call_to_complete(struct afs_call *call,
 		rtt2 = 2;
 
 	timeout = rtt2;
-	last_life = rxrpc_kernel_check_life(call->net->socket, call->rxcall);
+	rxrpc_kernel_check_life(call->net->socket, call->rxcall, &last_life);
 
 	add_wait_queue(&call->waitq, &myself);
 	for (;;) {
@@ -639,7 +640,12 @@ static long afs_wait_for_call_to_complete(struct afs_call *call,
 		if (afs_check_call_state(call, AFS_CALL_COMPLETE))
 			break;
 
-		life = rxrpc_kernel_check_life(call->net->socket, call->rxcall);
+		if (!rxrpc_kernel_check_life(call->net->socket, call->rxcall, &life)) {
+			/* rxrpc terminated the call. */
+			rxrpc_complete = true;
+			break;
+		}
+
 		if (timeout == 0 &&
 		    life == last_life && signal_pending(current)) {
 			if (stalled)
@@ -663,12 +669,16 @@ static long afs_wait_for_call_to_complete(struct afs_call *call,
 	remove_wait_queue(&call->waitq, &myself);
 	__set_current_state(TASK_RUNNING);
 
-	/* Kill off the call if it's still live. */
 	if (!afs_check_call_state(call, AFS_CALL_COMPLETE)) {
-		_debug("call interrupted");
-		if (rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
-					    RX_USER_ABORT, -EINTR, "KWI"))
-			afs_set_call_complete(call, -EINTR, 0);
+		if (rxrpc_complete) {
+			afs_set_call_complete(call, call->error, call->abort_code);
+		} else {
+			/* Kill off the call if it's still live. */
+			_debug("call interrupted");
+			if (rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
+						    RX_USER_ABORT, -EINTR, "KWI"))
+				afs_set_call_complete(call, -EINTR, 0);
+		}
 	}
 
 	spin_lock_bh(&call->state_lock);
diff --git a/include/net/af_rxrpc.h b/include/net/af_rxrpc.h
index 2bfb87eb98ce..78c856cba4f5 100644
--- a/include/net/af_rxrpc.h
+++ b/include/net/af_rxrpc.h
@@ -61,10 +61,12 @@ int rxrpc_kernel_charge_accept(struct socket *, rxrpc_notify_rx_t,
 			       rxrpc_user_attach_call_t, unsigned long, gfp_t,
 			       unsigned int);
 void rxrpc_kernel_set_tx_length(struct socket *, struct rxrpc_call *, s64);
-u32 rxrpc_kernel_check_life(const struct socket *, const struct rxrpc_call *);
+bool rxrpc_kernel_check_life(const struct socket *, const struct rxrpc_call *,
+			     u32 *);
 void rxrpc_kernel_probe_life(struct socket *, struct rxrpc_call *);
 u32 rxrpc_kernel_get_epoch(struct socket *, struct rxrpc_call *);
 bool rxrpc_kernel_get_reply_time(struct socket *, struct rxrpc_call *,
 				 ktime_t *);
+bool rxrpc_kernel_call_is_complete(struct rxrpc_call *);
 
 #endif /* _NET_RXRPC_H */
diff --git a/net/rxrpc/af_rxrpc.c b/net/rxrpc/af_rxrpc.c
index c54dce3ca0dd..ae8c5d7f3bf1 100644
--- a/net/rxrpc/af_rxrpc.c
+++ b/net/rxrpc/af_rxrpc.c
@@ -371,18 +371,22 @@ EXPORT_SYMBOL(rxrpc_kernel_end_call);
  * rxrpc_kernel_check_life - Check to see whether a call is still alive
  * @sock: The socket the call is on
  * @call: The call to check
+ * @_life: Where to store the life value
  *
  * Allow a kernel service to find out whether a call is still alive - ie. we're
- * getting ACKs from the server.  Returns a number representing the life state
- * which can be compared to that returned by a previous call.
+ * getting ACKs from the server.  Passes back in *_life a number representing
+ * the life state which can be compared to that returned by a previous call and
+ * return true if the call is still alive.
  *
  * If the life state stalls, rxrpc_kernel_probe_life() should be called and
  * then 2RTT waited.
  */
-u32 rxrpc_kernel_check_life(const struct socket *sock,
-			    const struct rxrpc_call *call)
+bool rxrpc_kernel_check_life(const struct socket *sock,
+			     const struct rxrpc_call *call,
+			     u32 *_life)
 {
-	return call->acks_latest;
+	*_life = call->acks_latest;
+	return call->state != RXRPC_CALL_COMPLETE;
 }
 EXPORT_SYMBOL(rxrpc_kernel_check_life);
 
diff --git a/net/rxrpc/ar-internal.h b/net/rxrpc/ar-internal.h
index 4b1a534d290a..062ca9dc29b8 100644
--- a/net/rxrpc/ar-internal.h
+++ b/net/rxrpc/ar-internal.h
@@ -654,6 +654,7 @@ struct rxrpc_call {
 	u8			ackr_reason;	/* reason to ACK */
 	u16			ackr_skew;	/* skew on packet being ACK'd */
 	rxrpc_serial_t		ackr_serial;	/* serial of packet being ACK'd */
+	rxrpc_serial_t		ackr_first_seq;	/* first sequence number received */
 	rxrpc_seq_t		ackr_prev_seq;	/* previous sequence number received */
 	rxrpc_seq_t		ackr_consumed;	/* Highest packet shown consumed */
 	rxrpc_seq_t		ackr_seen;	/* Highest packet shown seen */
diff --git a/net/rxrpc/conn_event.c b/net/rxrpc/conn_event.c
index b6fca8ebb117..8d31fb4c51e1 100644
--- a/net/rxrpc/conn_event.c
+++ b/net/rxrpc/conn_event.c
@@ -153,7 +153,8 @@ static void rxrpc_conn_retransmit_call(struct rxrpc_connection *conn,
  * pass a connection-level abort onto all calls on that connection
  */
 static void rxrpc_abort_calls(struct rxrpc_connection *conn,
-			      enum rxrpc_call_completion compl)
+			      enum rxrpc_call_completion compl,
+			      rxrpc_serial_t serial)
 {
 	struct rxrpc_call *call;
 	int i;
@@ -173,6 +174,9 @@ static void rxrpc_abort_calls(struct rxrpc_connection *conn,
 						  call->call_id, 0,
 						  conn->abort_code,
 						  conn->error);
+			else
+				trace_rxrpc_rx_abort(call, serial,
+						     conn->abort_code);
 			if (rxrpc_set_call_completion(call, compl,
 						      conn->abort_code,
 						      conn->error))
@@ -213,8 +217,6 @@ static int rxrpc_abort_connection(struct rxrpc_connection *conn,
 	conn->state = RXRPC_CONN_LOCALLY_ABORTED;
 	spin_unlock_bh(&conn->state_lock);
 
-	rxrpc_abort_calls(conn, RXRPC_CALL_LOCALLY_ABORTED);
-
 	msg.msg_name	= &conn->params.peer->srx.transport;
 	msg.msg_namelen	= conn->params.peer->srx.transport_len;
 	msg.msg_control	= NULL;
@@ -242,6 +244,7 @@ static int rxrpc_abort_connection(struct rxrpc_connection *conn,
 	len = iov[0].iov_len + iov[1].iov_len;
 
 	serial = atomic_inc_return(&conn->serial);
+	rxrpc_abort_calls(conn, RXRPC_CALL_LOCALLY_ABORTED, serial);
 	whdr.serial = htonl(serial);
 	_proto("Tx CONN ABORT %%%u { %d }", serial, conn->abort_code);
 
@@ -321,7 +324,7 @@ static int rxrpc_process_event(struct rxrpc_connection *conn,
 		conn->error = -ECONNABORTED;
 		conn->abort_code = abort_code;
 		conn->state = RXRPC_CONN_REMOTELY_ABORTED;
-		rxrpc_abort_calls(conn, RXRPC_CALL_REMOTELY_ABORTED);
+		rxrpc_abort_calls(conn, RXRPC_CALL_REMOTELY_ABORTED, sp->hdr.serial);
 		return -ECONNABORTED;
 
 	case RXRPC_PACKET_TYPE_CHALLENGE:
diff --git a/net/rxrpc/input.c b/net/rxrpc/input.c
index 9128aa0e40aa..4c6f9d0a00e7 100644
--- a/net/rxrpc/input.c
+++ b/net/rxrpc/input.c
@@ -837,7 +837,7 @@ static void rxrpc_input_ack(struct rxrpc_call *call, struct sk_buff *skb,
 		u8 acks[RXRPC_MAXACKS];
 	} buf;
 	rxrpc_serial_t acked_serial;
-	rxrpc_seq_t first_soft_ack, hard_ack;
+	rxrpc_seq_t first_soft_ack, hard_ack, prev_pkt;
 	int nr_acks, offset, ioffset;
 
 	_enter("");
@@ -851,13 +851,14 @@ static void rxrpc_input_ack(struct rxrpc_call *call, struct sk_buff *skb,
 
 	acked_serial = ntohl(buf.ack.serial);
 	first_soft_ack = ntohl(buf.ack.firstPacket);
+	prev_pkt = ntohl(buf.ack.previousPacket);
 	hard_ack = first_soft_ack - 1;
 	nr_acks = buf.ack.nAcks;
 	summary.ack_reason = (buf.ack.reason < RXRPC_ACK__INVALID ?
 			      buf.ack.reason : RXRPC_ACK__INVALID);
 
 	trace_rxrpc_rx_ack(call, sp->hdr.serial, acked_serial,
-			   first_soft_ack, ntohl(buf.ack.previousPacket),
+			   first_soft_ack, prev_pkt,
 			   summary.ack_reason, nr_acks);
 
 	if (buf.ack.reason == RXRPC_ACK_PING_RESPONSE)
@@ -878,8 +879,9 @@ static void rxrpc_input_ack(struct rxrpc_call *call, struct sk_buff *skb,
 				  rxrpc_propose_ack_respond_to_ack);
 	}
 
-	/* Discard any out-of-order or duplicate ACKs. */
-	if (before_eq(sp->hdr.serial, call->acks_latest))
+	/* Discard any out-of-order or duplicate ACKs (outside lock). */
+	if (before(first_soft_ack, call->ackr_first_seq) ||
+	    before(prev_pkt, call->ackr_prev_seq))
 		return;
 
 	buf.info.rxMTU = 0;
@@ -890,12 +892,16 @@ static void rxrpc_input_ack(struct rxrpc_call *call, struct sk_buff *skb,
 
 	spin_lock(&call->input_lock);
 
-	/* Discard any out-of-order or duplicate ACKs. */
-	if (before_eq(sp->hdr.serial, call->acks_latest))
+	/* Discard any out-of-order or duplicate ACKs (inside lock). */
+	if (before(first_soft_ack, call->ackr_first_seq) ||
+	    before(prev_pkt, call->ackr_prev_seq))
 		goto out;
 	call->acks_latest_ts = skb->tstamp;
 	call->acks_latest = sp->hdr.serial;
 
+	call->ackr_first_seq = first_soft_ack;
+	call->ackr_prev_seq = prev_pkt;
+
 	/* Parse rwind and mtu sizes if provided. */
 	if (buf.info.rxMTU)
 		rxrpc_input_ackinfo(call, skb, &buf.info);
diff --git a/net/rxrpc/peer_event.c b/net/rxrpc/peer_event.c
index bc05af89fc38..6e84d878053c 100644
--- a/net/rxrpc/peer_event.c
+++ b/net/rxrpc/peer_event.c
@@ -157,6 +157,11 @@ void rxrpc_error_report(struct sock *sk)
 
 	_enter("%p{%d}", sk, local->debug_id);
 
+	/* Clear the outstanding error value on the socket so that it doesn't
+	 * cause kernel_sendmsg() to return it later.
+	 */
+	sock_error(sk);
+
 	skb = sock_dequeue_err_skb(sk);
 	if (!skb) {
 		_leave("UDP socket errqueue empty");
diff --git a/net/rxrpc/sendmsg.c b/net/rxrpc/sendmsg.c
index 46c9312085b1..bec64deb7b0a 100644
--- a/net/rxrpc/sendmsg.c
+++ b/net/rxrpc/sendmsg.c
@@ -152,12 +152,13 @@ static void rxrpc_notify_end_tx(struct rxrpc_sock *rx, struct rxrpc_call *call,
 }
 
 /*
- * Queue a DATA packet for transmission, set the resend timeout and send the
- * packet immediately
+ * Queue a DATA packet for transmission, set the resend timeout and send
+ * the packet immediately.  Returns the error from rxrpc_send_data_packet()
+ * in case the caller wants to do something with it.
  */
-static void rxrpc_queue_packet(struct rxrpc_sock *rx, struct rxrpc_call *call,
-			       struct sk_buff *skb, bool last,
-			       rxrpc_notify_end_tx_t notify_end_tx)
+static int rxrpc_queue_packet(struct rxrpc_sock *rx, struct rxrpc_call *call,
+			      struct sk_buff *skb, bool last,
+			      rxrpc_notify_end_tx_t notify_end_tx)
 {
 	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 	unsigned long now;
@@ -250,7 +251,8 @@ static void rxrpc_queue_packet(struct rxrpc_sock *rx, struct rxrpc_call *call,
 
 out:
 	rxrpc_free_skb(skb, rxrpc_skb_tx_freed);
-	_leave("");
+	_leave(" = %d", ret);
+	return ret;
 }
 
 /*
@@ -423,9 +425,10 @@ static int rxrpc_send_data(struct rxrpc_sock *rx,
 			if (ret < 0)
 				goto out;
 
-			rxrpc_queue_packet(rx, call, skb,
-					   !msg_data_left(msg) && !more,
-					   notify_end_tx);
+			ret = rxrpc_queue_packet(rx, call, skb,
+						 !msg_data_left(msg) && !more,
+						 notify_end_tx);
+			/* Should check for failure here */
 			skb = NULL;
 		}
 	} while (msg_data_left(msg) > 0);