rxrpc: Fix lockup due to no error backoff after ack transmit error

[mirror_ubuntu-jammy-kernel.git] / net / rxrpc / output.c

diff --git a/net/rxrpc/output.c b/net/rxrpc/output.c
index 1894188888391fca2ef98a5324de7bc99c4b381f..736aa92811004cfe5d157abd4827710783f8d57c 100644 (file)
--- a/net/rxrpc/output.c
+++ b/net/rxrpc/output.c
@@ -34,6 +34,21 @@ struct rxrpc_abort_buffer {
 
 static const char rxrpc_keepalive_string[] = "";
 
+/*
+ * Increase Tx backoff on transmission failure and clear it on success.
+ */
+static void rxrpc_tx_backoff(struct rxrpc_call *call, int ret)
+{
+       if (ret < 0) {
+               u16 tx_backoff = READ_ONCE(call->tx_backoff);
+
+               if (tx_backoff < HZ)
+                       WRITE_ONCE(call->tx_backoff, tx_backoff + 1);
+       } else {
+               WRITE_ONCE(call->tx_backoff, 0);
+       }
+}
+
 /*
  * Arrange for a keepalive ping a certain time after we last transmitted.  This
  * lets the far side know we're still interested in this call and helps keep
@@ -210,6 +225,7 @@ int rxrpc_send_ack_packet(struct rxrpc_call *call, bool ping,
        else
                trace_rxrpc_tx_packet(call->debug_id, &pkt->whdr,
                                      rxrpc_tx_point_call_ack);
+       rxrpc_tx_backoff(call, ret);
 
        if (call->state < RXRPC_CALL_COMPLETE) {
                if (ret < 0) {
@@ -218,7 +234,7 @@ int rxrpc_send_ack_packet(struct rxrpc_call *call, bool ping,
                        rxrpc_propose_ACK(call, pkt->ack.reason,
                                          ntohs(pkt->ack.maxSkew),
                                          ntohl(pkt->ack.serial),
-                                         true, true,
+                                         false, true,
                                          rxrpc_propose_ack_retry_tx);
                } else {
                        spin_lock_bh(&call->lock);
@@ -300,7 +316,7 @@ int rxrpc_send_abort_packet(struct rxrpc_call *call)
        else
                trace_rxrpc_tx_packet(call->debug_id, &pkt.whdr,
                                      rxrpc_tx_point_call_abort);
-
+       rxrpc_tx_backoff(call, ret);
 
        rxrpc_put_connection(conn);
        return ret;
@@ -413,6 +429,7 @@ int rxrpc_send_data_packet(struct rxrpc_call *call, struct sk_buff *skb,
        else
                trace_rxrpc_tx_packet(call->debug_id, &whdr,
                                      rxrpc_tx_point_call_data_nofrag);
+       rxrpc_tx_backoff(call, ret);
        if (ret == -EMSGSIZE)
                goto send_fragmentable;
 
@@ -445,9 +462,18 @@ done:
                        rxrpc_reduce_call_timer(call, expect_rx_by, nowj,
                                                rxrpc_timer_set_for_normal);
                }
-       }
 
-       rxrpc_set_keepalive(call);
+               rxrpc_set_keepalive(call);
+       } else {
+               /* Cancel the call if the initial transmission fails,
+                * particularly if that's due to network routing issues that
+                * aren't going away anytime soon.  The layer above can arrange
+                * the retransmission.
+                */
+               if (!test_and_set_bit(RXRPC_CALL_BEGAN_RX_TIMER, &call->flags))
+                       rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR,
+                                                 RX_USER_ABORT, ret);
+       }
 
        _leave(" = %d [%u]", ret, call->peer->maxdata);
        return ret;
@@ -506,6 +532,7 @@ send_fragmentable:
        else
                trace_rxrpc_tx_packet(call->debug_id, &whdr,
                                      rxrpc_tx_point_call_data_frag);
+       rxrpc_tx_backoff(call, ret);
 
        up_write(&conn->params.local->defrag_sem);
        goto done;