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>
This commit is contained in:
Sowmini Varadhan 2018-01-18 13:11:07 -08:00 committed by David S. Miller
parent ab18a9c9ca
commit b589513e63
3 changed files with 6 additions and 5 deletions

View File

@ -90,9 +90,10 @@ void rds_tcp_nonagle(struct socket *sock)
sizeof(val));
}
u32 rds_tcp_snd_nxt(struct rds_tcp_connection *tc)
u32 rds_tcp_write_seq(struct rds_tcp_connection *tc)
{
return tcp_sk(tc->t_sock->sk)->snd_nxt;
/* seq# of the last byte of data in tcp send buffer */
return tcp_sk(tc->t_sock->sk)->write_seq;
}
u32 rds_tcp_snd_una(struct rds_tcp_connection *tc)

View File

@ -54,7 +54,7 @@ void rds_tcp_set_callbacks(struct socket *sock, struct rds_conn_path *cp);
void rds_tcp_reset_callbacks(struct socket *sock, struct rds_conn_path *cp);
void rds_tcp_restore_callbacks(struct socket *sock,
struct rds_tcp_connection *tc);
u32 rds_tcp_snd_nxt(struct rds_tcp_connection *tc);
u32 rds_tcp_write_seq(struct rds_tcp_connection *tc);
u32 rds_tcp_snd_una(struct rds_tcp_connection *tc);
u64 rds_tcp_map_seq(struct rds_tcp_connection *tc, u32 seq);
extern struct rds_transport rds_tcp_transport;

View File

@ -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);
}