rxrpc: Don't let ack.previousPacket regress

[ Upstream commit 81524b6312535897707f2942695da1d359a5e56b ]

The previousPacket field in the rx ACK packet should never go backwards -
it's now the highest DATA sequence number received, not the last on
received (it used to be used for out of sequence detection).

Fixes: 248f219cb8bc ("rxrpc: Rewrite the data and ack handling code")
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/net/rxrpc/ar-internal.h b/net/rxrpc/ar-internal.h
index 9a9688c..8465985 100644 (file)
--- a/net/rxrpc/ar-internal.h
+++ b/net/rxrpc/ar-internal.h
@@ -679,7 +679,7 @@ struct rxrpc_call {
        /* Receive-phase ACK management (ACKs we send). */
        u8                      ackr_reason;    /* reason to ACK */
        rxrpc_serial_t          ackr_serial;    /* serial of packet being ACK'd */
-       rxrpc_seq_t             ackr_prev_seq;  /* previous sequence number received */
+       rxrpc_seq_t             ackr_highest_seq; /* Higest sequence number received */
        rxrpc_seq_t             ackr_consumed;  /* Highest packet shown consumed */
        rxrpc_seq_t             ackr_seen;      /* Highest packet shown seen */
 
@@ -694,7 +694,7 @@ struct rxrpc_call {
        /* Transmission-phase ACK management (ACKs we've received). */
        ktime_t                 acks_latest_ts; /* Timestamp of latest ACK received */
        rxrpc_seq_t             acks_first_seq; /* first sequence number received */
-       rxrpc_seq_t             acks_prev_seq;  /* previous sequence number received */
+       rxrpc_seq_t             acks_prev_seq;  /* Highest previousPacket received */
        rxrpc_seq_t             acks_lowest_nak; /* Lowest NACK in the buffer (or ==tx_hard_ack) */
        rxrpc_seq_t             acks_lost_top;  /* tx_top at the time lost-ack ping sent */
        rxrpc_serial_t          acks_lost_ping; /* Serial number of probe ACK */

diff --git a/net/rxrpc/input.c b/net/rxrpc/input.c
index 3da33b5..680b984 100644 (file)
--- a/net/rxrpc/input.c
+++ b/net/rxrpc/input.c
@@ -453,7 +453,6 @@ static void rxrpc_input_data(struct rxrpc_call *call, struct sk_buff *skb)
            !rxrpc_receiving_reply(call))
                goto unlock;
 
-       call->ackr_prev_seq = seq0;
        hard_ack = READ_ONCE(call->rx_hard_ack);
 
        nr_subpackets = sp->nr_subpackets;
@@ -534,6 +533,9 @@ static void rxrpc_input_data(struct rxrpc_call *call, struct sk_buff *skb)
                        ack_serial = serial;
                }
 
+               if (after(seq0, call->ackr_highest_seq))
+                       call->ackr_highest_seq = seq0;
+
                /* Queue the packet.  We use a couple of memory barriers here as need
                 * to make sure that rx_top is perceived to be set after the buffer
                 * pointer and that the buffer pointer is set after the annotation and

diff --git a/net/rxrpc/output.c b/net/rxrpc/output.c
index a45c83f..46aae9b 100644 (file)
--- a/net/rxrpc/output.c
+++ b/net/rxrpc/output.c
@@ -89,7 +89,7 @@ static size_t rxrpc_fill_out_ack(struct rxrpc_connection *conn,
        pkt->ack.bufferSpace    = htons(8);
        pkt->ack.maxSkew        = htons(0);
        pkt->ack.firstPacket    = htonl(hard_ack + 1);
-       pkt->ack.previousPacket = htonl(call->ackr_prev_seq);
+       pkt->ack.previousPacket = htonl(call->ackr_highest_seq);
        pkt->ack.serial         = htonl(serial);
        pkt->ack.reason         = reason;
        pkt->ack.nAcks          = top - hard_ack;