Commit b589513e authored by Sowmini Varadhan's avatar Sowmini Varadhan Committed by David S. Miller
Browse files

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: default avatarSowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent ab18a9c9

net/rds/tcp.c

+3 −2
Original line number Diff line number Diff line
@@ -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)

net/rds/tcp.h

+1 −1
Original line number Diff line number Diff line
@@ -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;

net/rds/tcp_send.c

+2 −2
Original line number Diff line number Diff line
@@ -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);

	}

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