rxrpc: Make Tx loss-injection go through normal return and adjust tracing

In rxrpc_send_data_packet() make the loss-injection path return through the
same code as the transmission path so that the RTT determination is
initiated and any future timer shuffling will be done, despite the packet
having been binned.

Whilst we're at it:

 (1) Add to the tx_data tracepoint an indication of whether or not we're
     retransmitting a data packet.

 (2) When we're deciding whether or not to request an ACK, rather than
     checking if we're in fast-retransmit mode check instead if we're
     retransmitting.

 (3) Don't invoke the lose_skb tracepoint when losing a Tx packet as we're
     not altering the sk_buff refcount nor are we just seeing it after
     getting it off the Tx list.

 (4) The rxrpc_skb_tx_lost note is then no longer used so remove it.

 (5) rxrpc_lose_skb() no longer needs to deal with rxrpc_skb_tx_lost.

Signed-off-by: David Howells <dhowells@redhat.com>

diff --git a/include/trace/events/rxrpc.h b/include/trace/events/rxrpc.h
index ada12d00118c9230d384911a4b194a8e23106460..8ba8d76e856ad60e04845154e0e0301b818db6c4 100644 (file)
--- a/include/trace/events/rxrpc.h
+++ b/include/trace/events/rxrpc.h
@@ -258,15 +258,16 @@ TRACE_EVENT(rxrpc_rx_ack,
 
 TRACE_EVENT(rxrpc_tx_data,
            TP_PROTO(struct rxrpc_call *call, rxrpc_seq_t seq,
-                    rxrpc_serial_t serial, u8 flags, bool lose),
+                    rxrpc_serial_t serial, u8 flags, bool retrans, bool lose),
 
-           TP_ARGS(call, seq, serial, flags, lose),
+           TP_ARGS(call, seq, serial, flags, retrans, lose),
 
            TP_STRUCT__entry(
                    __field(struct rxrpc_call *,        call            )
                    __field(rxrpc_seq_t,                seq             )
                    __field(rxrpc_serial_t,             serial          )
                    __field(u8,                         flags           )
+                   __field(bool,                       retrans         )
                    __field(bool,                       lose            )
                             ),
 
@@ -275,6 +276,7 @@ TRACE_EVENT(rxrpc_tx_data,
                    __entry->seq = seq;
                    __entry->serial = serial;
                    __entry->flags = flags;
+                   __entry->retrans = retrans;
                    __entry->lose = lose;
                           ),
 

diff --git a/net/rxrpc/ar-internal.h b/net/rxrpc/ar-internal.h
index ca96e547cb9ac1b1ebdc49594af683f90e53a35e..6aadaa7d8b4374f7850812ece742d58a4183cc52 100644 (file)
--- a/net/rxrpc/ar-internal.h
+++ b/net/rxrpc/ar-internal.h
@@ -603,7 +603,6 @@ enum rxrpc_skb_trace {
        rxrpc_skb_tx_cleaned,
        rxrpc_skb_tx_freed,
        rxrpc_skb_tx_got,
-       rxrpc_skb_tx_lost,
        rxrpc_skb_tx_new,
        rxrpc_skb_tx_rotated,
        rxrpc_skb_tx_seen,
@@ -1073,7 +1072,7 @@ extern const s8 rxrpc_ack_priority[];
  * output.c
  */
 int rxrpc_send_call_packet(struct rxrpc_call *, u8);
-int rxrpc_send_data_packet(struct rxrpc_call *, struct sk_buff *);
+int rxrpc_send_data_packet(struct rxrpc_call *, struct sk_buff *, bool);
 void rxrpc_reject_packets(struct rxrpc_local *);
 
 /*

diff --git a/net/rxrpc/call_event.c b/net/rxrpc/call_event.c
index 0e8478012212ec800bc6d26a5205f679e83a2fb8..1f6c7633b96480cfc619eabc26ba37036852c4ba 100644 (file)
--- a/net/rxrpc/call_event.c
+++ b/net/rxrpc/call_event.c
@@ -256,7 +256,7 @@ static void rxrpc_resend(struct rxrpc_call *call)
                rxrpc_get_skb(skb, rxrpc_skb_tx_got);
                spin_unlock_bh(&call->lock);
 
-               if (rxrpc_send_data_packet(call, skb) < 0) {
+               if (rxrpc_send_data_packet(call, skb, true) < 0) {
                        rxrpc_free_skb(skb, rxrpc_skb_tx_freed);
                        return;
                }

diff --git a/net/rxrpc/misc.c b/net/rxrpc/misc.c
index aedb8978226d2361a407295aa6e6c252384b0973..47dddacdbb91a9881daaee8694f5df003385f36d 100644 (file)
--- a/net/rxrpc/misc.c
+++ b/net/rxrpc/misc.c
@@ -108,7 +108,6 @@ const char rxrpc_skb_traces[rxrpc_skb__nr_trace][7] = {
        [rxrpc_skb_tx_cleaned]          = "Tx CLN",
        [rxrpc_skb_tx_freed]            = "Tx FRE",
        [rxrpc_skb_tx_got]              = "Tx GOT",
-       [rxrpc_skb_tx_lost]             = "Tx *L*",
        [rxrpc_skb_tx_new]              = "Tx NEW",
        [rxrpc_skb_tx_rotated]          = "Tx ROT",
        [rxrpc_skb_tx_seen]             = "Tx SEE",

diff --git a/net/rxrpc/output.c b/net/rxrpc/output.c
index cf43a715685eab1deae47340e341d823dab8797e..ac9a58b619a62abd6c4888d3e97c5792a64cbcde 100644 (file)
--- a/net/rxrpc/output.c
+++ b/net/rxrpc/output.c
@@ -238,7 +238,8 @@ out:
 /*
  * send a packet through the transport endpoint
  */
-int rxrpc_send_data_packet(struct rxrpc_call *call, struct sk_buff *skb)
+int rxrpc_send_data_packet(struct rxrpc_call *call, struct sk_buff *skb,
+                          bool retrans)
 {
        struct rxrpc_connection *conn = call->conn;
        struct rxrpc_wire_header whdr;
@@ -247,6 +248,7 @@ int rxrpc_send_data_packet(struct rxrpc_call *call, struct sk_buff *skb)
        struct kvec iov[2];
        rxrpc_serial_t serial;
        size_t len;
+       bool lost = false;
        int ret, opt;
 
        _enter(",{%d}", skb->len);
@@ -281,7 +283,7 @@ int rxrpc_send_data_packet(struct rxrpc_call *call, struct sk_buff *skb)
        /* If our RTT cache needs working on, request an ACK.  Also request
         * ACKs if a DATA packet appears to have been lost.
         */
-       if (call->cong_mode == RXRPC_CALL_FAST_RETRANSMIT ||
+       if (retrans ||
            (call->peer->rtt_usage < 3 && sp->hdr.seq & 1) ||
            ktime_before(ktime_add_ms(call->peer->rtt_last_req, 1000),
                         ktime_get_real()))
@@ -290,11 +292,9 @@ int rxrpc_send_data_packet(struct rxrpc_call *call, struct sk_buff *skb)
        if (IS_ENABLED(CONFIG_AF_RXRPC_INJECT_LOSS)) {
                static int lose;
                if ((lose++ & 7) == 7) {
-                       trace_rxrpc_tx_data(call, sp->hdr.seq, serial,
-                                           whdr.flags, true);
-                       rxrpc_lose_skb(skb, rxrpc_skb_tx_lost);
-                       _leave(" = 0 [lose]");
-                       return 0;
+                       ret = 0;
+                       lost = true;
+                       goto done;
                }
        }
 
@@ -319,7 +319,8 @@ int rxrpc_send_data_packet(struct rxrpc_call *call, struct sk_buff *skb)
                goto send_fragmentable;
 
 done:
-       trace_rxrpc_tx_data(call, sp->hdr.seq, serial, whdr.flags, false);
+       trace_rxrpc_tx_data(call, sp->hdr.seq, serial, whdr.flags,
+                           retrans, lost);
        if (ret >= 0) {
                ktime_t now = ktime_get_real();
                skb->tstamp = now;

diff --git a/net/rxrpc/sendmsg.c b/net/rxrpc/sendmsg.c
index 1f8040d823959ffe8178fffcedc30a8511b2534b..d8dfdce874d8b20e06fca9b7323fe668fecf6c6a 100644 (file)
--- a/net/rxrpc/sendmsg.c
+++ b/net/rxrpc/sendmsg.c
@@ -144,7 +144,7 @@ static void rxrpc_queue_packet(struct rxrpc_call *call, struct sk_buff *skb,
        if (seq == 1 && rxrpc_is_client_call(call))
                rxrpc_expose_client_call(call);
 
-       ret = rxrpc_send_data_packet(call, skb);
+       ret = rxrpc_send_data_packet(call, skb, false);
        if (ret < 0) {
                _debug("need instant resend %d", ret);
                rxrpc_instant_resend(call, ix);

diff --git a/net/rxrpc/skbuff.c b/net/rxrpc/skbuff.c
index 5154cbf7e540c55efdd8a8dc94abd294005e4e39..67b02c45271ba80be022c77c9c84abe4de2b1c47 100644 (file)
--- a/net/rxrpc/skbuff.c
+++ b/net/rxrpc/skbuff.c
@@ -77,14 +77,9 @@ void rxrpc_lose_skb(struct sk_buff *skb, enum rxrpc_skb_trace op)
        if (skb) {
                int n;
                CHECK_SLAB_OKAY(&skb->users);
-               if (op == rxrpc_skb_tx_lost) {
-                       n = atomic_read(select_skb_count(op));
-                       trace_rxrpc_skb(skb, op, atomic_read(&skb->users), n, here);
-               } else {
-                       n = atomic_dec_return(select_skb_count(op));
-                       trace_rxrpc_skb(skb, op, atomic_read(&skb->users), n, here);
-                       kfree_skb(skb);
-               }
+               n = atomic_dec_return(select_skb_count(op));
+               trace_rxrpc_skb(skb, op, atomic_read(&skb->users), n, here);
+               kfree_skb(skb);
        }
 }