net/smc: save state of last sent CDC message

When a link goes down and all connections of this link need to be
switched to an other link then the producer cursor and the sequence of
the last successfully sent CDC message must be known. Add the two fields
to the SMC connection and update it in the tx completion handler.
And to allow matching of sequences in error cases reset the seqno to the
old value in smc_cdc_msg_send() when the actual send failed.

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 6 insertions, 0 deletions

diff --git a/net/smc/smc_cdc.c b/net/smc/smc_cdc.c
index f64589d823aa..c5e33296e55c 100644
--- a/net/smc/smc_cdc.c
+++ b/net/smc/smc_cdc.c
@@ -47,6 +47,9 @@ static void smc_cdc_tx_handler(struct smc_wr_tx_pend_priv *pnd_snd,
 		/* guarantee 0 <= sndbuf_space <= sndbuf_desc->len */
 		smp_mb__after_atomic();
 		smc_curs_copy(&conn->tx_curs_fin, &cdcpend->cursor, conn);
+		smc_curs_copy(&conn->local_tx_ctrl_fin, &cdcpend->p_cursor,
+			      conn);
+		conn->tx_cdc_seq_fin = cdcpend->ctrl_seq;
 	}
 	smc_tx_sndbuf_nonfull(smc);
 	bh_unlock_sock(&smc->sk);
@@ -104,6 +107,9 @@ int smc_cdc_msg_send(struct smc_connection *conn,
 	if (!rc) {
 		smc_curs_copy(&conn->rx_curs_confirmed, &cfed, conn);
 		conn->local_rx_ctrl.prod_flags.cons_curs_upd_req = 0;
+	} else {
+		conn->tx_cdc_seq--;
+		conn->local_tx_ctrl.seqno = conn->tx_cdc_seq;
 	}
 
 	return rc;