rds: tcp: compute m_ack_seq as offset from ->write_seq

rds-tcp uses m_ack_seq to track the tcp ack# that indicates
that the peer has received a rds_message. The m_ack_seq is
used in rds_tcp_is_acked() to figure out when it is safe to
drop the rds_message from the RDS retransmit queue.

The m_ack_seq must be calculated as an offset from the right
edge of the in-flight tcp buffer, i.e., it should be based on
the ->write_seq, not the ->snd_nxt.

Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 2 deletions

diff --git a/net/rds/tcp_send.c b/net/rds/tcp_send.c
index dc860d1bb608..9b76e0fa1722 100644
--- a/net/rds/tcp_send.c
+++ b/net/rds/tcp_send.c
@@ -86,7 +86,7 @@ int rds_tcp_xmit(struct rds_connection *conn, struct rds_message *rm,
                  * m_ack_seq is set to the sequence number of the last byte of
                  * header and data.  see rds_tcp_is_acked().
                  */
-                tc->t_last_sent_nxt = rds_tcp_snd_nxt(tc);
+                tc->t_last_sent_nxt = rds_tcp_write_seq(tc);
                 rm->m_ack_seq = tc->t_last_sent_nxt +
                                 sizeof(struct rds_header) +
                                 be32_to_cpu(rm->m_inc.i_hdr.h_len) - 1;
@@ -98,7 +98,7 @@ int rds_tcp_xmit(struct rds_connection *conn, struct rds_message *rm,
                         rm->m_inc.i_hdr.h_flags |= RDS_FLAG_RETRANSMITTED;
 
                 rdsdebug("rm %p tcp nxt %u ack_seq %llu\n",
-                         rm, rds_tcp_snd_nxt(tc),
+                         rm, rds_tcp_write_seq(tc),
                          (unsigned long long)rm->m_ack_seq);
         }