2 * Copyright (c) 2006 Oracle. All rights reserved.
4 * This software is available to you under a choice of one of two
5 * licenses. You may choose to be licensed under the terms of the GNU
6 * General Public License (GPL) Version 2, available from the file
7 * COPYING in the main directory of this source tree, or the
8 * OpenIB.org BSD license below:
10 * Redistribution and use in source and binary forms, with or
11 * without modification, are permitted provided that the following
14 * - Redistributions of source code must retain the above
15 * copyright notice, this list of conditions and the following
18 * - Redistributions in binary form must reproduce the above
19 * copyright notice, this list of conditions and the following
20 * disclaimer in the documentation and/or other materials
21 * provided with the distribution.
23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
24 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
25 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
26 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
27 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
28 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
29 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
33 #include <linux/kernel.h>
40 static void rds_tcp_cork(struct socket
*sock
, int val
)
46 sock
->ops
->setsockopt(sock
, SOL_TCP
, TCP_CORK
, (char __user
*)&val
,
51 void rds_tcp_xmit_prepare(struct rds_connection
*conn
)
53 struct rds_tcp_connection
*tc
= conn
->c_transport_data
;
55 rds_tcp_cork(tc
->t_sock
, 1);
58 void rds_tcp_xmit_complete(struct rds_connection
*conn
)
60 struct rds_tcp_connection
*tc
= conn
->c_transport_data
;
62 rds_tcp_cork(tc
->t_sock
, 0);
65 /* the core send_sem serializes this with other xmit and shutdown */
66 int rds_tcp_sendmsg(struct socket
*sock
, void *data
, unsigned int len
)
73 .msg_flags
= MSG_DONTWAIT
| MSG_NOSIGNAL
,
76 return kernel_sendmsg(sock
, &msg
, &vec
, 1, vec
.iov_len
);
79 /* the core send_sem serializes this with other xmit and shutdown */
80 int rds_tcp_xmit_cong_map(struct rds_connection
*conn
,
81 struct rds_cong_map
*map
, unsigned long offset
)
83 static struct rds_header rds_tcp_map_header
= {
84 .h_flags
= RDS_FLAG_CONG_BITMAP
,
86 struct rds_tcp_connection
*tc
= conn
->c_transport_data
;
91 /* Some problem claims cpu_to_be32(constant) isn't a constant. */
92 rds_tcp_map_header
.h_len
= cpu_to_be32(RDS_CONG_MAP_BYTES
);
94 if (offset
< sizeof(struct rds_header
)) {
95 ret
= rds_tcp_sendmsg(tc
->t_sock
,
96 (void *)&rds_tcp_map_header
+ offset
,
97 sizeof(struct rds_header
) - offset
);
102 if (offset
< sizeof(struct rds_header
))
106 offset
-= sizeof(struct rds_header
);
107 i
= offset
/ PAGE_SIZE
;
108 offset
= offset
% PAGE_SIZE
;
109 BUG_ON(i
>= RDS_CONG_MAP_PAGES
);
112 ret
= tc
->t_sock
->ops
->sendpage(tc
->t_sock
,
113 virt_to_page(map
->m_page_addrs
[i
]),
114 offset
, PAGE_SIZE
- offset
,
120 if (offset
== PAGE_SIZE
) {
124 } while (i
< RDS_CONG_MAP_PAGES
);
126 return copied
? copied
: ret
;
129 /* the core send_sem serializes this with other xmit and shutdown */
130 int rds_tcp_xmit(struct rds_connection
*conn
, struct rds_message
*rm
,
131 unsigned int hdr_off
, unsigned int sg
, unsigned int off
)
133 struct rds_tcp_connection
*tc
= conn
->c_transport_data
;
139 * m_ack_seq is set to the sequence number of the last byte of
140 * header and data. see rds_tcp_is_acked().
142 tc
->t_last_sent_nxt
= rds_tcp_snd_nxt(tc
);
143 rm
->m_ack_seq
= tc
->t_last_sent_nxt
+
144 sizeof(struct rds_header
) +
145 be32_to_cpu(rm
->m_inc
.i_hdr
.h_len
) - 1;
146 smp_mb__before_clear_bit();
147 set_bit(RDS_MSG_HAS_ACK_SEQ
, &rm
->m_flags
);
148 tc
->t_last_expected_una
= rm
->m_ack_seq
+ 1;
150 rdsdebug("rm %p tcp nxt %u ack_seq %llu\n",
151 rm
, rds_tcp_snd_nxt(tc
),
152 (unsigned long long)rm
->m_ack_seq
);
155 if (hdr_off
< sizeof(struct rds_header
)) {
156 /* see rds_tcp_write_space() */
157 set_bit(SOCK_NOSPACE
, &tc
->t_sock
->sk
->sk_socket
->flags
);
159 ret
= rds_tcp_sendmsg(tc
->t_sock
,
160 (void *)&rm
->m_inc
.i_hdr
+ hdr_off
,
161 sizeof(rm
->m_inc
.i_hdr
) - hdr_off
);
165 if (hdr_off
+ done
!= sizeof(struct rds_header
))
169 while (sg
< rm
->m_nents
) {
170 ret
= tc
->t_sock
->ops
->sendpage(tc
->t_sock
,
171 sg_page(&rm
->m_sg
[sg
]),
172 rm
->m_sg
[sg
].offset
+ off
,
173 rm
->m_sg
[sg
].length
- off
,
174 MSG_DONTWAIT
|MSG_NOSIGNAL
);
175 rdsdebug("tcp sendpage %p:%u:%u ret %d\n", (void *)sg_page(&rm
->m_sg
[sg
]),
176 rm
->m_sg
[sg
].offset
+ off
, rm
->m_sg
[sg
].length
- off
,
183 if (off
== rm
->m_sg
[sg
].length
) {
191 /* write_space will hit after EAGAIN, all else fatal */
192 if (ret
== -EAGAIN
) {
193 rds_tcp_stats_inc(s_tcp_sndbuf_full
);
196 printk(KERN_WARNING
"RDS/tcp: send to %u.%u.%u.%u "
197 "returned %d, disconnecting and reconnecting\n",
198 NIPQUAD(conn
->c_faddr
), ret
);
208 * rm->m_ack_seq is set to the tcp sequence number that corresponds to the
209 * last byte of the message, including the header. This means that the
210 * entire message has been received if rm->m_ack_seq is "before" the next
211 * unacked byte of the TCP sequence space. We have to do very careful
212 * wrapping 32bit comparisons here.
214 static int rds_tcp_is_acked(struct rds_message
*rm
, uint64_t ack
)
216 if (!test_bit(RDS_MSG_HAS_ACK_SEQ
, &rm
->m_flags
))
218 return (__s32
)((u32
)rm
->m_ack_seq
- (u32
)ack
) < 0;
221 void rds_tcp_write_space(struct sock
*sk
)
223 void (*write_space
)(struct sock
*sk
);
224 struct rds_connection
*conn
;
225 struct rds_tcp_connection
*tc
;
227 read_lock(&sk
->sk_callback_lock
);
228 conn
= sk
->sk_user_data
;
230 write_space
= sk
->sk_write_space
;
234 tc
= conn
->c_transport_data
;
235 rdsdebug("write_space for tc %p\n", tc
);
236 write_space
= tc
->t_orig_write_space
;
237 rds_tcp_stats_inc(s_tcp_write_space_calls
);
239 rdsdebug("tcp una %u\n", rds_tcp_snd_una(tc
));
240 tc
->t_last_seen_una
= rds_tcp_snd_una(tc
);
241 rds_send_drop_acked(conn
, rds_tcp_snd_una(tc
), rds_tcp_is_acked
);
243 queue_delayed_work(rds_wq
, &conn
->c_send_w
, 0);
245 read_unlock(&sk
->sk_callback_lock
);
248 * write_space is only called when data leaves tcp's send queue if
249 * SOCK_NOSPACE is set. We set SOCK_NOSPACE every time we put
250 * data in tcp's send queue because we use write_space to parse the
251 * sequence numbers and notice that rds messages have been fully
254 * tcp's write_space clears SOCK_NOSPACE if the send queue has more
255 * than a certain amount of space. So we need to set it again *after*
256 * we call tcp's write_space or else we might only get called on the
257 * first of a series of incoming tcp acks.
262 set_bit(SOCK_NOSPACE
, &sk
->sk_socket
->flags
);