@@ -98,6 +98,7 @@ struct rxrpc_net {
atomic_t stat_tx_data_send;
atomic_t stat_tx_data_send_frag;
atomic_t stat_tx_data_send_fail;
+ atomic_t stat_tx_data_send_msgsize;
atomic_t stat_tx_data_underflow;
atomic_t stat_tx_data_cwnd_reset;
atomic_t stat_rx_data;
@@ -551,16 +551,11 @@ static int rxrpc_send_data_packet(struct rxrpc_call *call, struct rxrpc_txbuf *t
msg.msg_controllen = 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
- * yet.
+ /* Send the packet with the don't fragment bit set unless we think it's
+ * too big or if this is a retransmission.
*/
- if (txb->seq == call->tx_transmitted + 1)
- call->tx_transmitted = txb->seq + n - 1;
-
- /* send the packet with the don't fragment bit set if we currently
- * think it's small enough */
- if (len >= sizeof(struct rxrpc_wire_header) + call->peer->max_data) {
+ if (txb->seq == call->tx_transmitted + 1 &&
+ len >= sizeof(struct rxrpc_wire_header) + call->peer->max_data) {
rxrpc_local_dont_fragment(conn->local, false);
frag = rxrpc_tx_point_call_data_frag;
} else {
@@ -568,6 +563,13 @@ static int rxrpc_send_data_packet(struct rxrpc_call *call, struct rxrpc_txbuf *t
frag = rxrpc_tx_point_call_data_nofrag;
}
+ /* 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
+ * yet.
+ */
+ if (txb->seq == call->tx_transmitted + 1)
+ call->tx_transmitted = txb->seq + n - 1;
+
if (IS_ENABLED(CONFIG_AF_RXRPC_INJECT_LOSS)) {
static int lose;
if ((lose++ & 7) == 7) {
@@ -578,7 +580,6 @@ static int rxrpc_send_data_packet(struct rxrpc_call *call, struct rxrpc_txbuf *t
}
}
-retry:
/* send the packet by UDP
* - returns -EMSGSIZE if UDP would have to fragment the packet
* to go out of the interface
@@ -589,7 +590,11 @@ static int rxrpc_send_data_packet(struct rxrpc_call *call, struct rxrpc_txbuf *t
ret = do_udp_sendmsg(conn->local->socket, &msg, len);
conn->peer->last_tx_at = ktime_get_seconds();
- if (ret < 0) {
+ if (ret == -EMSGSIZE) {
+ rxrpc_inc_stat(call->rxnet, stat_tx_data_send_msgsize);
+ trace_rxrpc_tx_packet(call->debug_id, call->local->kvec[0].iov_base, frag);
+ ret = 0;
+ } else if (ret < 0) {
rxrpc_inc_stat(call->rxnet, stat_tx_data_send_fail);
trace_rxrpc_tx_fail(call->debug_id, txb->serial, ret, frag);
} else {
@@ -597,11 +602,6 @@ static int rxrpc_send_data_packet(struct rxrpc_call *call, struct rxrpc_txbuf *t
}
rxrpc_tx_backoff(call, ret);
- if (ret == -EMSGSIZE && frag == rxrpc_tx_point_call_data_nofrag) {
- rxrpc_local_dont_fragment(conn->local, false);
- frag = rxrpc_tx_point_call_data_frag;
- goto retry;
- }
done:
if (ret >= 0) {
@@ -476,10 +476,11 @@ int rxrpc_stats_show(struct seq_file *seq, void *v)
struct rxrpc_net *rxnet = rxrpc_net(seq_file_single_net(seq));
seq_printf(seq,
- "Data : send=%u sendf=%u fail=%u\n",
+ "Data : send=%u sendf=%u fail=%u emsz=%u\n",
atomic_read(&rxnet->stat_tx_data_send),
atomic_read(&rxnet->stat_tx_data_send_frag),
- atomic_read(&rxnet->stat_tx_data_send_fail));
+ atomic_read(&rxnet->stat_tx_data_send_fail),
+ atomic_read(&rxnet->stat_tx_data_send_msgsize));
seq_printf(seq,
"Data-Tx : nr=%u retrans=%u uf=%u cwr=%u\n",
atomic_read(&rxnet->stat_tx_data),
Change how the DF flag is managed on DATA transmissions. Set it on initial transmission and don't set it on retransmissions. Then remove the handling for EMSGSIZE in rxrpc_send_data_packet() and just pretend it didn't happen, leaving it to the retransmission path to retry. The path-MTU discovery using PING ACKs is then used to probe for the maximum DATA size - though notification by ICMP will be used if one is received. 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 --- net/rxrpc/ar-internal.h | 1 + net/rxrpc/output.c | 32 ++++++++++++++++---------------- net/rxrpc/proc.c | 5 +++-- 3 files changed, 20 insertions(+), 18 deletions(-)