rxrpc: Do zerocopy using MSG_SPLICE_PAGES and page frags

[linux-2.6-microblaze.git] / net / rxrpc / output.c

diff --git a/net/rxrpc/output.c b/net/rxrpc/output.c
index 5398aa2..0a31749 100644 (file)
--- a/net/rxrpc/output.c
+++ b/net/rxrpc/output.c
@@ -83,18 +83,16 @@ static void rxrpc_fill_out_ack(struct rxrpc_call *call,
                               rxrpc_serial_t serial)
 {
        struct rxrpc_wire_header *whdr = txb->kvec[0].iov_base;
+       struct rxrpc_acktrailer *trailer = txb->kvec[2].iov_base + 3;
        struct rxrpc_ackpacket *ack = (struct rxrpc_ackpacket *)(whdr + 1);
-       struct rxrpc_acktrailer trailer;
        unsigned int qsize, sack, wrap, to;
        rxrpc_seq_t window, wtop;
        int rsize;
        u32 mtu, jmax;
-       u8 *ackp = txb->acks;
+       u8 *filler = txb->kvec[2].iov_base;
+       u8 *sackp = txb->kvec[1].iov_base;
 
-       call->ackr_nr_unacked = 0;
-       atomic_set(&call->ackr_nr_consumed, 0);
        rxrpc_inc_stat(call->rxnet, stat_tx_ack_fill);
-       clear_bit(RXRPC_CALL_RX_IS_IDLE, &call->flags);
 
        window = call->ackr_window;
        wtop   = call->ackr_wtop;
@@ -110,20 +108,27 @@ static void rxrpc_fill_out_ack(struct rxrpc_call *call,
        ack->serial             = htonl(serial);
        ack->reason             = ack_reason;
        ack->nAcks              = wtop - window;
+       filler[0]               = 0;
+       filler[1]               = 0;
+       filler[2]               = 0;
+
+       if (ack_reason == RXRPC_ACK_PING)
+               txb->flags |= RXRPC_REQUEST_ACK;
 
        if (after(wtop, window)) {
+               txb->len += ack->nAcks;
+               txb->kvec[1].iov_base = sackp;
+               txb->kvec[1].iov_len = ack->nAcks;
+
                wrap = RXRPC_SACK_SIZE - sack;
                to = min_t(unsigned int, ack->nAcks, RXRPC_SACK_SIZE);
 
                if (sack + ack->nAcks <= RXRPC_SACK_SIZE) {
-                       memcpy(txb->acks, call->ackr_sack_table + sack, ack->nAcks);
+                       memcpy(sackp, call->ackr_sack_table + sack, ack->nAcks);
                } else {
-                       memcpy(txb->acks, call->ackr_sack_table + sack, wrap);
-                       memcpy(txb->acks + wrap, call->ackr_sack_table,
-                              to - wrap);
+                       memcpy(sackp, call->ackr_sack_table + sack, wrap);
+                       memcpy(sackp + wrap, call->ackr_sack_table, to - wrap);
                }
-
-               ackp += to;
        } else if (before(wtop, window)) {
                pr_warn("ack window backward %x %x", window, wtop);
        } else if (ack->reason == RXRPC_ACK_DELAY) {
@@ -135,18 +140,11 @@ static void rxrpc_fill_out_ack(struct rxrpc_call *call,
        jmax = rxrpc_rx_jumbo_max;
        qsize = (window - 1) - call->rx_consumed;
        rsize = max_t(int, call->rx_winsize - qsize, 0);
-       txb->ack_rwind          = rsize;
-       trailer.maxMTU          = htonl(rxrpc_rx_mtu);
-       trailer.ifMTU           = htonl(mtu);
-       trailer.rwind           = htonl(rsize);
-       trailer.jumbo_max       = htonl(jmax);
-
-       *ackp++ = 0;
-       *ackp++ = 0;
-       *ackp++ = 0;
-       memcpy(ackp, &trailer, sizeof(trailer));
-       txb->kvec[0].iov_len += sizeof(*ack) + ack->nAcks + 3 + sizeof(trailer);
-       txb->len = txb->kvec[0].iov_len;
+       txb->ack_rwind = rsize;
+       trailer->maxMTU         = htonl(rxrpc_rx_mtu);
+       trailer->ifMTU          = htonl(mtu);
+       trailer->rwind          = htonl(rsize);
+       trailer->jumbo_max      = htonl(jmax);
 }
 
 /*
@@ -195,7 +193,7 @@ static void rxrpc_cancel_rtt_probe(struct rxrpc_call *call,
 /*
  * Transmit an ACK packet.
  */
-static int rxrpc_send_ack_packet(struct rxrpc_call *call, struct rxrpc_txbuf *txb)
+static void rxrpc_send_ack_packet(struct rxrpc_call *call, struct rxrpc_txbuf *txb)
 {
        struct rxrpc_wire_header *whdr = txb->kvec[0].iov_base;
        struct rxrpc_connection *conn;
@@ -204,7 +202,7 @@ static int rxrpc_send_ack_packet(struct rxrpc_call *call, struct rxrpc_txbuf *tx
        int ret, rtt_slot = -1;
 
        if (test_bit(RXRPC_CALL_DISCONNECTED, &call->flags))
-               return -ECONNRESET;
+               return;
 
        conn = call->conn;
 
@@ -212,10 +210,8 @@ static int rxrpc_send_ack_packet(struct rxrpc_call *call, struct rxrpc_txbuf *tx
        msg.msg_namelen = call->peer->srx.transport_len;
        msg.msg_control = NULL;
        msg.msg_controllen = 0;
-       msg.msg_flags   = 0;
+       msg.msg_flags   = MSG_SPLICE_PAGES;
 
-       if (ack->reason == RXRPC_ACK_PING)
-               txb->flags |= RXRPC_REQUEST_ACK;
        whdr->flags = txb->flags & RXRPC_TXBUF_WIRE_FLAGS;
 
        txb->serial = rxrpc_get_next_serial(conn);
@@ -250,8 +246,6 @@ static int rxrpc_send_ack_packet(struct rxrpc_call *call, struct rxrpc_txbuf *tx
                        rxrpc_cancel_rtt_probe(call, txb->serial, rtt_slot);
                rxrpc_set_keepalive(call);
        }
-
-       return ret;
 }
 
 /*
@@ -267,16 +261,19 @@ void rxrpc_send_ACK(struct rxrpc_call *call, u8 ack_reason,
 
        rxrpc_inc_stat(call->rxnet, stat_tx_acks[ack_reason]);
 
-       txb = rxrpc_alloc_txbuf(call, RXRPC_PACKET_TYPE_ACK,
-                               rcu_read_lock_held() ? GFP_ATOMIC | __GFP_NOWARN : GFP_NOFS);
+       txb = rxrpc_alloc_ack_txbuf(call, call->ackr_wtop - call->ackr_window);
        if (!txb) {
                kleave(" = -ENOMEM");
                return;
        }
 
+       txb->ack_why = why;
+
        rxrpc_fill_out_ack(call, txb, ack_reason, serial);
+       call->ackr_nr_unacked = 0;
+       atomic_set(&call->ackr_nr_consumed, 0);
+       clear_bit(RXRPC_CALL_RX_IS_IDLE, &call->flags);
 
-       txb->ack_why = why;
        trace_rxrpc_send_ack(call, why, ack_reason, serial);
        rxrpc_send_ack_packet(call, txb);
        rxrpc_put_txbuf(txb, rxrpc_txbuf_put_ack_tx);
@@ -465,7 +462,7 @@ static int rxrpc_send_data_packet(struct rxrpc_call *call, struct rxrpc_txbuf *t
        msg.msg_namelen = call->peer->srx.transport_len;
        msg.msg_control = NULL;
        msg.msg_controllen = 0;
-       msg.msg_flags   = 0;
+       msg.msg_flags   = MSG_SPLICE_PAGES;
 
        /* Track what we've attempted to transmit at least once so that the
         * retransmission algorithm doesn't try to resend what we haven't sent