rxrpc: Do lazy DF flag resetting

Don't reset the DF flag after transmission, but rather set it when needed
since it should be a fast op now that we call IP directly.

This includes turning it off for RESPONSE packets and, for the moment, ACK
packets.  In future, we will need to turn it on for ACK packets used to do
path MTU discovery.

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 1e039b6f4494a540b8b5a3234738d127640327f6..8aa8ba32eacc188296289477b1a0e575e69a68ad 100644 (file)
--- a/net/rxrpc/output.c
+++ b/net/rxrpc/output.c
@@ -231,6 +231,7 @@ int rxrpc_send_ack_packet(struct rxrpc_call *call, struct rxrpc_txbuf *txb)
        txb->ack.previousPacket = htonl(call->rx_highest_seq);
 
        iov_iter_kvec(&msg.msg_iter, WRITE, iov, 1, len);
+       rxrpc_local_dont_fragment(conn->local, false);
        ret = do_udp_sendmsg(conn->local->socket, &msg, len);
        call->peer->last_tx_at = ktime_get_seconds();
        if (ret < 0) {
@@ -406,6 +407,7 @@ dont_set_request_ack:
         * think it's small enough */
        if (txb->len >= call->peer->maxdata)
                goto send_fragmentable;
+       rxrpc_local_dont_fragment(conn->local, true);
 
        txb->wire.flags = txb->flags & RXRPC_TXBUF_WIRE_FLAGS;
        txb->last_sent = ktime_get_real();
@@ -492,8 +494,6 @@ send_fragmentable:
                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();
-
-               rxrpc_local_dont_fragment(conn->local, true);
                break;
 
        default:

diff --git a/net/rxrpc/rxkad.c b/net/rxrpc/rxkad.c
index 28c9ce763be4f76a9b993c674058a8ac73646b68..e451ac90bfee5c47da71e094c6883f731a90cc31 100644 (file)
--- a/net/rxrpc/rxkad.c
+++ b/net/rxrpc/rxkad.c
@@ -726,7 +726,6 @@ static int rxkad_send_response(struct rxrpc_connection *conn,
 
        rxrpc_local_dont_fragment(conn->local, false);
        ret = kernel_sendmsg(conn->local->socket, &msg, iov, 3, len);
-       rxrpc_local_dont_fragment(conn->local, true);
        if (ret < 0) {
                trace_rxrpc_tx_fail(conn->debug_id, serial, ret,
                                    rxrpc_tx_point_rxkad_response);