rxrpc: Merge together DF/non-DF branches of data Tx function

Merge together the DF and non-DF branches of the transmission function and
always set the flag to the right thing before transmitting.  If we see
-EMSGSIZE from udp_sendmsg(), turn off DF and retry.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: "David S. Miller" <davem@davemloft.net>
cc: Eric Dumazet <edumazet@google.com>
cc: Jakub Kicinski <kuba@kernel.org>
cc: Paolo Abeni <pabeni@redhat.com>
cc: linux-afs@lists.infradead.org
cc: netdev@vger.kernel.org

diff --git a/net/rxrpc/output.c b/net/rxrpc/output.c
index 8aa8ba32eacc188296289477b1a0e575e69a68ad..e2c9e645fcfb9d7f8646d86f061e54ca2bfc5641 100644 (file)
--- a/net/rxrpc/output.c
+++ b/net/rxrpc/output.c
@@ -323,8 +323,9 @@ int rxrpc_send_abort_packet(struct rxrpc_call *call)
  */
 int rxrpc_send_data_packet(struct rxrpc_call *call, struct rxrpc_txbuf *txb)
 {
-       enum rxrpc_req_ack_trace why;
        struct rxrpc_connection *conn = call->conn;
+       enum rxrpc_req_ack_trace why;
+       enum rxrpc_tx_point frag;
        struct msghdr msg;
        struct kvec iov[1];
        size_t len;
@@ -405,11 +406,16 @@ dont_set_request_ack:
 
        /* send the packet with the don't fragment bit set if we currently
         * think it's small enough */
-       if (txb->len >= call->peer->maxdata)
-               goto send_fragmentable;
-       rxrpc_local_dont_fragment(conn->local, true);
+       if (txb->len >= call->peer->maxdata) {
+               rxrpc_local_dont_fragment(conn->local, false);
+               frag = rxrpc_tx_point_call_data_frag;
+       } else {
+               rxrpc_local_dont_fragment(conn->local, true);
+               frag = rxrpc_tx_point_call_data_nofrag;
+       }
 
        txb->wire.flags = txb->flags & RXRPC_TXBUF_WIRE_FLAGS;
+retry:
        txb->last_sent = ktime_get_real();
        if (txb->flags & RXRPC_REQUEST_ACK)
                rtt_slot = rxrpc_begin_rtt_probe(call, txb->serial, rxrpc_rtt_tx_data);
@@ -435,8 +441,11 @@ dont_set_request_ack:
        }
 
        rxrpc_tx_backoff(call, ret);
-       if (ret == -EMSGSIZE)
-               goto send_fragmentable;
+       if (ret == -EMSGSIZE && frag == rxrpc_tx_point_call_data_frag) {
+               rxrpc_local_dont_fragment(conn->local, false);
+               frag = rxrpc_tx_point_call_data_frag;
+               goto retry;
+       }
 
 done:
        if (ret >= 0) {
@@ -478,39 +487,6 @@ done:
 
        _leave(" = %d [%u]", ret, call->peer->maxdata);
        return ret;
-
-send_fragmentable:
-       /* attempt to send this message with fragmentation enabled */
-       _debug("send fragment");
-
-       txb->last_sent = ktime_get_real();
-       if (txb->flags & RXRPC_REQUEST_ACK)
-               rtt_slot = rxrpc_begin_rtt_probe(call, txb->serial, rxrpc_rtt_tx_data);
-
-       switch (conn->local->srx.transport.family) {
-       case AF_INET6:
-       case AF_INET:
-               rxrpc_local_dont_fragment(conn->local, false);
-               rxrpc_inc_stat(call->rxnet, stat_tx_data_send_frag);
-               ret = do_udp_sendmsg(conn->local->socket, &msg, len);
-               conn->peer->last_tx_at = ktime_get_seconds();
-               break;
-
-       default:
-               BUG();
-       }
-
-       if (ret < 0) {
-               rxrpc_inc_stat(call->rxnet, stat_tx_data_send_fail);
-               rxrpc_cancel_rtt_probe(call, txb->serial, rtt_slot);
-               trace_rxrpc_tx_fail(call->debug_id, txb->serial, ret,
-                                   rxrpc_tx_point_call_data_frag);
-       } else {
-               trace_rxrpc_tx_packet(call->debug_id, &txb->wire,
-                                     rxrpc_tx_point_call_data_frag);
-       }
-       rxrpc_tx_backoff(call, ret);
-       goto done;
 }
 
 /*