blob: 72dbe7fc4f540067272f9fdf8c22f35db7f71c0d [file] [log] [blame]
Andy Grover5c115592009-02-24 15:30:27 +00001/*
2 * Copyright (c) 2006 Oracle. All rights reserved.
3 *
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:
9 *
10 * Redistribution and use in source and binary forms, with or
11 * without modification, are permitted provided that the following
12 * conditions are met:
13 *
14 * - Redistributions of source code must retain the above
15 * copyright notice, this list of conditions and the following
16 * disclaimer.
17 *
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.
22 *
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
30 * SOFTWARE.
31 *
32 */
33#include <linux/kernel.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090034#include <linux/gfp.h>
Andy Grover5c115592009-02-24 15:30:27 +000035#include <net/sock.h>
36#include <linux/in.h>
37#include <linux/list.h>
38
39#include "rds.h"
Andy Grover5c115592009-02-24 15:30:27 +000040
41/* When transmitting messages in rds_send_xmit, we need to emerge from
42 * time to time and briefly release the CPU. Otherwise the softlock watchdog
43 * will kick our shin.
44 * Also, it seems fairer to not let one busy connection stall all the
45 * others.
46 *
47 * send_batch_count is the number of times we'll loop in send_xmit. Setting
48 * it to 0 will restore the old behavior (where we looped until we had
49 * drained the queue).
50 */
51static int send_batch_count = 64;
52module_param(send_batch_count, int, 0444);
53MODULE_PARM_DESC(send_batch_count, " batch factor when working the send queue");
54
55/*
56 * Reset the send state. Caller must hold c_send_lock when calling here.
57 */
58void rds_send_reset(struct rds_connection *conn)
59{
60 struct rds_message *rm, *tmp;
61 unsigned long flags;
62
63 if (conn->c_xmit_rm) {
64 /* Tell the user the RDMA op is no longer mapped by the
65 * transport. This isn't entirely true (it's flushed out
66 * independently) but as the connection is down, there's
67 * no ongoing RDMA to/from that memory */
68 rds_message_unmapped(conn->c_xmit_rm);
69 rds_message_put(conn->c_xmit_rm);
70 conn->c_xmit_rm = NULL;
71 }
72 conn->c_xmit_sg = 0;
73 conn->c_xmit_hdr_off = 0;
74 conn->c_xmit_data_off = 0;
75 conn->c_xmit_rdma_sent = 0;
76
77 conn->c_map_queued = 0;
78
79 conn->c_unacked_packets = rds_sysctl_max_unacked_packets;
80 conn->c_unacked_bytes = rds_sysctl_max_unacked_bytes;
81
82 /* Mark messages as retransmissions, and move them to the send q */
83 spin_lock_irqsave(&conn->c_lock, flags);
84 list_for_each_entry_safe(rm, tmp, &conn->c_retrans, m_conn_item) {
85 set_bit(RDS_MSG_ACK_REQUIRED, &rm->m_flags);
86 set_bit(RDS_MSG_RETRANSMITTED, &rm->m_flags);
87 }
88 list_splice_init(&conn->c_retrans, &conn->c_send_queue);
89 spin_unlock_irqrestore(&conn->c_lock, flags);
90}
91
92/*
93 * We're making the concious trade-off here to only send one message
94 * down the connection at a time.
95 * Pro:
96 * - tx queueing is a simple fifo list
97 * - reassembly is optional and easily done by transports per conn
98 * - no per flow rx lookup at all, straight to the socket
99 * - less per-frag memory and wire overhead
100 * Con:
101 * - queued acks can be delayed behind large messages
102 * Depends:
103 * - small message latency is higher behind queued large messages
104 * - large message latency isn't starved by intervening small sends
105 */
106int rds_send_xmit(struct rds_connection *conn)
107{
108 struct rds_message *rm;
109 unsigned long flags;
110 unsigned int tmp;
111 unsigned int send_quota = send_batch_count;
112 struct scatterlist *sg;
113 int ret = 0;
114 int was_empty = 0;
115 LIST_HEAD(to_be_dropped);
116
117 /*
118 * sendmsg calls here after having queued its message on the send
119 * queue. We only have one task feeding the connection at a time. If
120 * another thread is already feeding the queue then we back off. This
121 * avoids blocking the caller and trading per-connection data between
122 * caches per message.
123 *
124 * The sem holder will issue a retry if they notice that someone queued
125 * a message after they stopped walking the send queue but before they
126 * dropped the sem.
127 */
128 if (!mutex_trylock(&conn->c_send_lock)) {
129 rds_stats_inc(s_send_sem_contention);
130 ret = -ENOMEM;
131 goto out;
132 }
133
134 if (conn->c_trans->xmit_prepare)
135 conn->c_trans->xmit_prepare(conn);
136
137 /*
138 * spin trying to push headers and data down the connection until
139 * the connection doens't make forward progress.
140 */
141 while (--send_quota) {
142 /*
143 * See if need to send a congestion map update if we're
144 * between sending messages. The send_sem protects our sole
145 * use of c_map_offset and _bytes.
146 * Note this is used only by transports that define a special
147 * xmit_cong_map function. For all others, we create allocate
148 * a cong_map message and treat it just like any other send.
149 */
150 if (conn->c_map_bytes) {
151 ret = conn->c_trans->xmit_cong_map(conn, conn->c_lcong,
152 conn->c_map_offset);
153 if (ret <= 0)
154 break;
155
156 conn->c_map_offset += ret;
157 conn->c_map_bytes -= ret;
158 if (conn->c_map_bytes)
159 continue;
160 }
161
162 /* If we're done sending the current message, clear the
163 * offset and S/G temporaries.
164 */
165 rm = conn->c_xmit_rm;
Andy Grover8690bfa2010-01-12 11:56:44 -0800166 if (rm &&
Andy Grover5c115592009-02-24 15:30:27 +0000167 conn->c_xmit_hdr_off == sizeof(struct rds_header) &&
Andy Grovere7791372010-01-12 12:15:02 -0800168 conn->c_xmit_sg == rm->data.m_nents) {
Andy Grover5c115592009-02-24 15:30:27 +0000169 conn->c_xmit_rm = NULL;
170 conn->c_xmit_sg = 0;
171 conn->c_xmit_hdr_off = 0;
172 conn->c_xmit_data_off = 0;
173 conn->c_xmit_rdma_sent = 0;
174
175 /* Release the reference to the previous message. */
176 rds_message_put(rm);
177 rm = NULL;
178 }
179
180 /* If we're asked to send a cong map update, do so.
181 */
Andy Grover8690bfa2010-01-12 11:56:44 -0800182 if (!rm && test_and_clear_bit(0, &conn->c_map_queued)) {
183 if (conn->c_trans->xmit_cong_map) {
Andy Grover5c115592009-02-24 15:30:27 +0000184 conn->c_map_offset = 0;
185 conn->c_map_bytes = sizeof(struct rds_header) +
186 RDS_CONG_MAP_BYTES;
187 continue;
188 }
189
190 rm = rds_cong_update_alloc(conn);
191 if (IS_ERR(rm)) {
192 ret = PTR_ERR(rm);
193 break;
194 }
195
196 conn->c_xmit_rm = rm;
197 }
198
199 /*
200 * Grab the next message from the send queue, if there is one.
201 *
202 * c_xmit_rm holds a ref while we're sending this message down
203 * the connction. We can use this ref while holding the
204 * send_sem.. rds_send_reset() is serialized with it.
205 */
Andy Grover8690bfa2010-01-12 11:56:44 -0800206 if (!rm) {
Andy Grover5c115592009-02-24 15:30:27 +0000207 unsigned int len;
208
209 spin_lock_irqsave(&conn->c_lock, flags);
210
211 if (!list_empty(&conn->c_send_queue)) {
212 rm = list_entry(conn->c_send_queue.next,
213 struct rds_message,
214 m_conn_item);
215 rds_message_addref(rm);
216
217 /*
218 * Move the message from the send queue to the retransmit
219 * list right away.
220 */
221 list_move_tail(&rm->m_conn_item, &conn->c_retrans);
222 }
223
224 spin_unlock_irqrestore(&conn->c_lock, flags);
225
Andy Grover8690bfa2010-01-12 11:56:44 -0800226 if (!rm) {
Andy Grover5c115592009-02-24 15:30:27 +0000227 was_empty = 1;
228 break;
229 }
230
231 /* Unfortunately, the way Infiniband deals with
232 * RDMA to a bad MR key is by moving the entire
233 * queue pair to error state. We cold possibly
234 * recover from that, but right now we drop the
235 * connection.
236 * Therefore, we never retransmit messages with RDMA ops.
237 */
Andy Groverff87e972010-01-12 14:13:15 -0800238 if (rm->rdma.m_rdma_op.r_active &&
Joe Perchesf64f9e72009-11-29 16:55:45 -0800239 test_bit(RDS_MSG_RETRANSMITTED, &rm->m_flags)) {
Andy Grover5c115592009-02-24 15:30:27 +0000240 spin_lock_irqsave(&conn->c_lock, flags);
241 if (test_and_clear_bit(RDS_MSG_ON_CONN, &rm->m_flags))
242 list_move(&rm->m_conn_item, &to_be_dropped);
243 spin_unlock_irqrestore(&conn->c_lock, flags);
244 rds_message_put(rm);
245 continue;
246 }
247
248 /* Require an ACK every once in a while */
249 len = ntohl(rm->m_inc.i_hdr.h_len);
Joe Perchesf64f9e72009-11-29 16:55:45 -0800250 if (conn->c_unacked_packets == 0 ||
251 conn->c_unacked_bytes < len) {
Andy Grover5c115592009-02-24 15:30:27 +0000252 __set_bit(RDS_MSG_ACK_REQUIRED, &rm->m_flags);
253
254 conn->c_unacked_packets = rds_sysctl_max_unacked_packets;
255 conn->c_unacked_bytes = rds_sysctl_max_unacked_bytes;
256 rds_stats_inc(s_send_ack_required);
257 } else {
258 conn->c_unacked_bytes -= len;
259 conn->c_unacked_packets--;
260 }
261
262 conn->c_xmit_rm = rm;
263 }
264
265 /*
266 * Try and send an rdma message. Let's see if we can
267 * keep this simple and require that the transport either
268 * send the whole rdma or none of it.
269 */
Andy Groverff87e972010-01-12 14:13:15 -0800270 if (rm->rdma.m_rdma_op.r_active && !conn->c_xmit_rdma_sent) {
271 ret = conn->c_trans->xmit_rdma(conn, &rm->rdma.m_rdma_op);
Andy Grover5c115592009-02-24 15:30:27 +0000272 if (ret)
273 break;
274 conn->c_xmit_rdma_sent = 1;
275 /* The transport owns the mapped memory for now.
276 * You can't unmap it while it's on the send queue */
277 set_bit(RDS_MSG_MAPPED, &rm->m_flags);
278 }
279
280 if (conn->c_xmit_hdr_off < sizeof(struct rds_header) ||
Andy Grovere7791372010-01-12 12:15:02 -0800281 conn->c_xmit_sg < rm->data.m_nents) {
Andy Grover5c115592009-02-24 15:30:27 +0000282 ret = conn->c_trans->xmit(conn, rm,
283 conn->c_xmit_hdr_off,
284 conn->c_xmit_sg,
285 conn->c_xmit_data_off);
286 if (ret <= 0)
287 break;
288
289 if (conn->c_xmit_hdr_off < sizeof(struct rds_header)) {
290 tmp = min_t(int, ret,
291 sizeof(struct rds_header) -
292 conn->c_xmit_hdr_off);
293 conn->c_xmit_hdr_off += tmp;
294 ret -= tmp;
295 }
296
Andy Grovere7791372010-01-12 12:15:02 -0800297 sg = &rm->data.m_sg[conn->c_xmit_sg];
Andy Grover5c115592009-02-24 15:30:27 +0000298 while (ret) {
299 tmp = min_t(int, ret, sg->length -
300 conn->c_xmit_data_off);
301 conn->c_xmit_data_off += tmp;
302 ret -= tmp;
303 if (conn->c_xmit_data_off == sg->length) {
304 conn->c_xmit_data_off = 0;
305 sg++;
306 conn->c_xmit_sg++;
307 BUG_ON(ret != 0 &&
Andy Grovere7791372010-01-12 12:15:02 -0800308 conn->c_xmit_sg == rm->data.m_nents);
Andy Grover5c115592009-02-24 15:30:27 +0000309 }
310 }
311 }
312 }
313
314 /* Nuke any messages we decided not to retransmit. */
315 if (!list_empty(&to_be_dropped))
316 rds_send_remove_from_sock(&to_be_dropped, RDS_RDMA_DROPPED);
317
318 if (conn->c_trans->xmit_complete)
319 conn->c_trans->xmit_complete(conn);
320
321 /*
322 * We might be racing with another sender who queued a message but
323 * backed off on noticing that we held the c_send_lock. If we check
324 * for queued messages after dropping the sem then either we'll
325 * see the queued message or the queuer will get the sem. If we
326 * notice the queued message then we trigger an immediate retry.
327 *
328 * We need to be careful only to do this when we stopped processing
329 * the send queue because it was empty. It's the only way we
330 * stop processing the loop when the transport hasn't taken
331 * responsibility for forward progress.
332 */
333 mutex_unlock(&conn->c_send_lock);
334
335 if (conn->c_map_bytes || (send_quota == 0 && !was_empty)) {
336 /* We exhausted the send quota, but there's work left to
337 * do. Return and (re-)schedule the send worker.
338 */
339 ret = -EAGAIN;
340 }
341
342 if (ret == 0 && was_empty) {
343 /* A simple bit test would be way faster than taking the
344 * spin lock */
345 spin_lock_irqsave(&conn->c_lock, flags);
346 if (!list_empty(&conn->c_send_queue)) {
347 rds_stats_inc(s_send_sem_queue_raced);
348 ret = -EAGAIN;
349 }
350 spin_unlock_irqrestore(&conn->c_lock, flags);
351 }
352out:
353 return ret;
354}
355
356static void rds_send_sndbuf_remove(struct rds_sock *rs, struct rds_message *rm)
357{
358 u32 len = be32_to_cpu(rm->m_inc.i_hdr.h_len);
359
360 assert_spin_locked(&rs->rs_lock);
361
362 BUG_ON(rs->rs_snd_bytes < len);
363 rs->rs_snd_bytes -= len;
364
365 if (rs->rs_snd_bytes == 0)
366 rds_stats_inc(s_send_queue_empty);
367}
368
369static inline int rds_send_is_acked(struct rds_message *rm, u64 ack,
370 is_acked_func is_acked)
371{
372 if (is_acked)
373 return is_acked(rm, ack);
374 return be64_to_cpu(rm->m_inc.i_hdr.h_sequence) <= ack;
375}
376
377/*
378 * Returns true if there are no messages on the send and retransmit queues
379 * which have a sequence number greater than or equal to the given sequence
380 * number.
381 */
382int rds_send_acked_before(struct rds_connection *conn, u64 seq)
383{
384 struct rds_message *rm, *tmp;
385 int ret = 1;
386
387 spin_lock(&conn->c_lock);
388
389 list_for_each_entry_safe(rm, tmp, &conn->c_retrans, m_conn_item) {
390 if (be64_to_cpu(rm->m_inc.i_hdr.h_sequence) < seq)
391 ret = 0;
392 break;
393 }
394
395 list_for_each_entry_safe(rm, tmp, &conn->c_send_queue, m_conn_item) {
396 if (be64_to_cpu(rm->m_inc.i_hdr.h_sequence) < seq)
397 ret = 0;
398 break;
399 }
400
401 spin_unlock(&conn->c_lock);
402
403 return ret;
404}
405
406/*
407 * This is pretty similar to what happens below in the ACK
408 * handling code - except that we call here as soon as we get
409 * the IB send completion on the RDMA op and the accompanying
410 * message.
411 */
412void rds_rdma_send_complete(struct rds_message *rm, int status)
413{
414 struct rds_sock *rs = NULL;
415 struct rds_rdma_op *ro;
416 struct rds_notifier *notifier;
Andy Grover9de08642010-03-29 16:50:54 -0700417 unsigned long flags;
Andy Grover5c115592009-02-24 15:30:27 +0000418
Andy Grover9de08642010-03-29 16:50:54 -0700419 spin_lock_irqsave(&rm->m_rs_lock, flags);
Andy Grover5c115592009-02-24 15:30:27 +0000420
Andy Groverff87e972010-01-12 14:13:15 -0800421 ro = &rm->rdma.m_rdma_op;
Joe Perchesf64f9e72009-11-29 16:55:45 -0800422 if (test_bit(RDS_MSG_ON_SOCK, &rm->m_flags) &&
Andy Groverff87e972010-01-12 14:13:15 -0800423 ro->r_active && ro->r_notify && ro->r_notifier) {
Andy Grover5c115592009-02-24 15:30:27 +0000424 notifier = ro->r_notifier;
425 rs = rm->m_rs;
426 sock_hold(rds_rs_to_sk(rs));
427
428 notifier->n_status = status;
429 spin_lock(&rs->rs_lock);
430 list_add_tail(&notifier->n_list, &rs->rs_notify_queue);
431 spin_unlock(&rs->rs_lock);
432
433 ro->r_notifier = NULL;
434 }
435
Andy Grover9de08642010-03-29 16:50:54 -0700436 spin_unlock_irqrestore(&rm->m_rs_lock, flags);
Andy Grover5c115592009-02-24 15:30:27 +0000437
438 if (rs) {
439 rds_wake_sk_sleep(rs);
440 sock_put(rds_rs_to_sk(rs));
441 }
442}
Andy Grover616b7572009-08-21 12:28:32 +0000443EXPORT_SYMBOL_GPL(rds_rdma_send_complete);
Andy Grover5c115592009-02-24 15:30:27 +0000444
445/*
446 * This is the same as rds_rdma_send_complete except we
447 * don't do any locking - we have all the ingredients (message,
448 * socket, socket lock) and can just move the notifier.
449 */
450static inline void
451__rds_rdma_send_complete(struct rds_sock *rs, struct rds_message *rm, int status)
452{
453 struct rds_rdma_op *ro;
454
Andy Groverff87e972010-01-12 14:13:15 -0800455 ro = &rm->rdma.m_rdma_op;
456 if (ro->r_active && ro->r_notify && ro->r_notifier) {
Andy Grover5c115592009-02-24 15:30:27 +0000457 ro->r_notifier->n_status = status;
458 list_add_tail(&ro->r_notifier->n_list, &rs->rs_notify_queue);
459 ro->r_notifier = NULL;
460 }
461
462 /* No need to wake the app - caller does this */
463}
464
465/*
466 * This is called from the IB send completion when we detect
467 * a RDMA operation that failed with remote access error.
468 * So speed is not an issue here.
469 */
470struct rds_message *rds_send_get_message(struct rds_connection *conn,
471 struct rds_rdma_op *op)
472{
473 struct rds_message *rm, *tmp, *found = NULL;
474 unsigned long flags;
475
476 spin_lock_irqsave(&conn->c_lock, flags);
477
478 list_for_each_entry_safe(rm, tmp, &conn->c_retrans, m_conn_item) {
Andy Groverff87e972010-01-12 14:13:15 -0800479 if (&rm->rdma.m_rdma_op == op) {
Andy Grover5c115592009-02-24 15:30:27 +0000480 atomic_inc(&rm->m_refcount);
481 found = rm;
482 goto out;
483 }
484 }
485
486 list_for_each_entry_safe(rm, tmp, &conn->c_send_queue, m_conn_item) {
Andy Groverff87e972010-01-12 14:13:15 -0800487 if (&rm->rdma.m_rdma_op == op) {
Andy Grover5c115592009-02-24 15:30:27 +0000488 atomic_inc(&rm->m_refcount);
489 found = rm;
490 break;
491 }
492 }
493
494out:
495 spin_unlock_irqrestore(&conn->c_lock, flags);
496
497 return found;
498}
Andy Grover616b7572009-08-21 12:28:32 +0000499EXPORT_SYMBOL_GPL(rds_send_get_message);
Andy Grover5c115592009-02-24 15:30:27 +0000500
501/*
502 * This removes messages from the socket's list if they're on it. The list
503 * argument must be private to the caller, we must be able to modify it
504 * without locks. The messages must have a reference held for their
505 * position on the list. This function will drop that reference after
506 * removing the messages from the 'messages' list regardless of if it found
507 * the messages on the socket list or not.
508 */
509void rds_send_remove_from_sock(struct list_head *messages, int status)
510{
Andy Grover561c7df2010-03-11 13:50:06 +0000511 unsigned long flags;
Andy Grover5c115592009-02-24 15:30:27 +0000512 struct rds_sock *rs = NULL;
513 struct rds_message *rm;
514
Andy Grover5c115592009-02-24 15:30:27 +0000515 while (!list_empty(messages)) {
Andy Grover561c7df2010-03-11 13:50:06 +0000516 int was_on_sock = 0;
517
Andy Grover5c115592009-02-24 15:30:27 +0000518 rm = list_entry(messages->next, struct rds_message,
519 m_conn_item);
520 list_del_init(&rm->m_conn_item);
521
522 /*
523 * If we see this flag cleared then we're *sure* that someone
524 * else beat us to removing it from the sock. If we race
525 * with their flag update we'll get the lock and then really
526 * see that the flag has been cleared.
527 *
528 * The message spinlock makes sure nobody clears rm->m_rs
529 * while we're messing with it. It does not prevent the
530 * message from being removed from the socket, though.
531 */
Andy Grover561c7df2010-03-11 13:50:06 +0000532 spin_lock_irqsave(&rm->m_rs_lock, flags);
Andy Grover5c115592009-02-24 15:30:27 +0000533 if (!test_bit(RDS_MSG_ON_SOCK, &rm->m_flags))
534 goto unlock_and_drop;
535
536 if (rs != rm->m_rs) {
537 if (rs) {
Andy Grover5c115592009-02-24 15:30:27 +0000538 rds_wake_sk_sleep(rs);
539 sock_put(rds_rs_to_sk(rs));
540 }
541 rs = rm->m_rs;
Andy Grover5c115592009-02-24 15:30:27 +0000542 sock_hold(rds_rs_to_sk(rs));
543 }
Tina Yang048c15e2010-03-11 13:50:00 +0000544 spin_lock(&rs->rs_lock);
Andy Grover5c115592009-02-24 15:30:27 +0000545
546 if (test_and_clear_bit(RDS_MSG_ON_SOCK, &rm->m_flags)) {
Andy Groverff87e972010-01-12 14:13:15 -0800547 struct rds_rdma_op *ro = &rm->rdma.m_rdma_op;
Andy Grover5c115592009-02-24 15:30:27 +0000548 struct rds_notifier *notifier;
549
550 list_del_init(&rm->m_sock_item);
551 rds_send_sndbuf_remove(rs, rm);
552
Andy Groverff87e972010-01-12 14:13:15 -0800553 if (ro->r_active && ro->r_notifier &&
554 (status || ro->r_notify)) {
Andy Grover5c115592009-02-24 15:30:27 +0000555 notifier = ro->r_notifier;
556 list_add_tail(&notifier->n_list,
557 &rs->rs_notify_queue);
558 if (!notifier->n_status)
559 notifier->n_status = status;
Andy Groverff87e972010-01-12 14:13:15 -0800560 rm->rdma.m_rdma_op.r_notifier = NULL;
Andy Grover5c115592009-02-24 15:30:27 +0000561 }
Andy Grover561c7df2010-03-11 13:50:06 +0000562 was_on_sock = 1;
Andy Grover5c115592009-02-24 15:30:27 +0000563 rm->m_rs = NULL;
564 }
Tina Yang048c15e2010-03-11 13:50:00 +0000565 spin_unlock(&rs->rs_lock);
Andy Grover5c115592009-02-24 15:30:27 +0000566
567unlock_and_drop:
Andy Grover561c7df2010-03-11 13:50:06 +0000568 spin_unlock_irqrestore(&rm->m_rs_lock, flags);
Andy Grover5c115592009-02-24 15:30:27 +0000569 rds_message_put(rm);
Andy Grover561c7df2010-03-11 13:50:06 +0000570 if (was_on_sock)
571 rds_message_put(rm);
Andy Grover5c115592009-02-24 15:30:27 +0000572 }
573
574 if (rs) {
Andy Grover5c115592009-02-24 15:30:27 +0000575 rds_wake_sk_sleep(rs);
576 sock_put(rds_rs_to_sk(rs));
577 }
Andy Grover5c115592009-02-24 15:30:27 +0000578}
579
580/*
581 * Transports call here when they've determined that the receiver queued
582 * messages up to, and including, the given sequence number. Messages are
583 * moved to the retrans queue when rds_send_xmit picks them off the send
584 * queue. This means that in the TCP case, the message may not have been
585 * assigned the m_ack_seq yet - but that's fine as long as tcp_is_acked
586 * checks the RDS_MSG_HAS_ACK_SEQ bit.
587 *
588 * XXX It's not clear to me how this is safely serialized with socket
589 * destruction. Maybe it should bail if it sees SOCK_DEAD.
590 */
591void rds_send_drop_acked(struct rds_connection *conn, u64 ack,
592 is_acked_func is_acked)
593{
594 struct rds_message *rm, *tmp;
595 unsigned long flags;
596 LIST_HEAD(list);
597
598 spin_lock_irqsave(&conn->c_lock, flags);
599
600 list_for_each_entry_safe(rm, tmp, &conn->c_retrans, m_conn_item) {
601 if (!rds_send_is_acked(rm, ack, is_acked))
602 break;
603
604 list_move(&rm->m_conn_item, &list);
605 clear_bit(RDS_MSG_ON_CONN, &rm->m_flags);
606 }
607
608 /* order flag updates with spin locks */
609 if (!list_empty(&list))
610 smp_mb__after_clear_bit();
611
612 spin_unlock_irqrestore(&conn->c_lock, flags);
613
614 /* now remove the messages from the sock list as needed */
615 rds_send_remove_from_sock(&list, RDS_RDMA_SUCCESS);
616}
Andy Grover616b7572009-08-21 12:28:32 +0000617EXPORT_SYMBOL_GPL(rds_send_drop_acked);
Andy Grover5c115592009-02-24 15:30:27 +0000618
619void rds_send_drop_to(struct rds_sock *rs, struct sockaddr_in *dest)
620{
621 struct rds_message *rm, *tmp;
622 struct rds_connection *conn;
Andy Grover7c82eaf2010-02-19 18:01:41 -0800623 unsigned long flags;
Andy Grover5c115592009-02-24 15:30:27 +0000624 LIST_HEAD(list);
Andy Grover5c115592009-02-24 15:30:27 +0000625
626 /* get all the messages we're dropping under the rs lock */
627 spin_lock_irqsave(&rs->rs_lock, flags);
628
629 list_for_each_entry_safe(rm, tmp, &rs->rs_send_queue, m_sock_item) {
630 if (dest && (dest->sin_addr.s_addr != rm->m_daddr ||
631 dest->sin_port != rm->m_inc.i_hdr.h_dport))
632 continue;
633
Andy Grover5c115592009-02-24 15:30:27 +0000634 list_move(&rm->m_sock_item, &list);
635 rds_send_sndbuf_remove(rs, rm);
636 clear_bit(RDS_MSG_ON_SOCK, &rm->m_flags);
Andy Grover5c115592009-02-24 15:30:27 +0000637 }
638
639 /* order flag updates with the rs lock */
Andy Grover7c82eaf2010-02-19 18:01:41 -0800640 smp_mb__after_clear_bit();
Andy Grover5c115592009-02-24 15:30:27 +0000641
642 spin_unlock_irqrestore(&rs->rs_lock, flags);
643
Andy Grover7c82eaf2010-02-19 18:01:41 -0800644 if (list_empty(&list))
645 return;
Andy Grover5c115592009-02-24 15:30:27 +0000646
Andy Grover7c82eaf2010-02-19 18:01:41 -0800647 /* Remove the messages from the conn */
Andy Grover5c115592009-02-24 15:30:27 +0000648 list_for_each_entry(rm, &list, m_sock_item) {
Andy Grover7c82eaf2010-02-19 18:01:41 -0800649
650 conn = rm->m_inc.i_conn;
Andy Grover7c82eaf2010-02-19 18:01:41 -0800651
Andy Grover9de08642010-03-29 16:50:54 -0700652 spin_lock_irqsave(&conn->c_lock, flags);
Andy Grover7c82eaf2010-02-19 18:01:41 -0800653 /*
654 * Maybe someone else beat us to removing rm from the conn.
655 * If we race with their flag update we'll get the lock and
656 * then really see that the flag has been cleared.
657 */
658 if (!test_and_clear_bit(RDS_MSG_ON_CONN, &rm->m_flags)) {
659 spin_unlock_irqrestore(&conn->c_lock, flags);
660 continue;
661 }
Andy Grover9de08642010-03-29 16:50:54 -0700662 list_del_init(&rm->m_conn_item);
663 spin_unlock_irqrestore(&conn->c_lock, flags);
Andy Grover7c82eaf2010-02-19 18:01:41 -0800664
665 /*
666 * Couldn't grab m_rs_lock in top loop (lock ordering),
667 * but we can now.
668 */
Andy Grover9de08642010-03-29 16:50:54 -0700669 spin_lock_irqsave(&rm->m_rs_lock, flags);
Andy Grover7c82eaf2010-02-19 18:01:41 -0800670
Tina Yang550a8002010-03-11 13:50:03 +0000671 spin_lock(&rs->rs_lock);
672 __rds_rdma_send_complete(rs, rm, RDS_RDMA_CANCELED);
673 spin_unlock(&rs->rs_lock);
Andy Grover7c82eaf2010-02-19 18:01:41 -0800674
Andy Grover5c115592009-02-24 15:30:27 +0000675 rm->m_rs = NULL;
Andy Grover9de08642010-03-29 16:50:54 -0700676 spin_unlock_irqrestore(&rm->m_rs_lock, flags);
Andy Grover5c115592009-02-24 15:30:27 +0000677
Andy Grover7c82eaf2010-02-19 18:01:41 -0800678 rds_message_put(rm);
Andy Grover5c115592009-02-24 15:30:27 +0000679 }
680
Andy Grover7c82eaf2010-02-19 18:01:41 -0800681 rds_wake_sk_sleep(rs);
Tina Yang550a8002010-03-11 13:50:03 +0000682
Andy Grover5c115592009-02-24 15:30:27 +0000683 while (!list_empty(&list)) {
684 rm = list_entry(list.next, struct rds_message, m_sock_item);
685 list_del_init(&rm->m_sock_item);
686
687 rds_message_wait(rm);
688 rds_message_put(rm);
689 }
690}
691
692/*
693 * we only want this to fire once so we use the callers 'queued'. It's
694 * possible that another thread can race with us and remove the
695 * message from the flow with RDS_CANCEL_SENT_TO.
696 */
697static int rds_send_queue_rm(struct rds_sock *rs, struct rds_connection *conn,
698 struct rds_message *rm, __be16 sport,
699 __be16 dport, int *queued)
700{
701 unsigned long flags;
702 u32 len;
703
704 if (*queued)
705 goto out;
706
707 len = be32_to_cpu(rm->m_inc.i_hdr.h_len);
708
709 /* this is the only place which holds both the socket's rs_lock
710 * and the connection's c_lock */
711 spin_lock_irqsave(&rs->rs_lock, flags);
712
713 /*
714 * If there is a little space in sndbuf, we don't queue anything,
715 * and userspace gets -EAGAIN. But poll() indicates there's send
716 * room. This can lead to bad behavior (spinning) if snd_bytes isn't
717 * freed up by incoming acks. So we check the *old* value of
718 * rs_snd_bytes here to allow the last msg to exceed the buffer,
719 * and poll() now knows no more data can be sent.
720 */
721 if (rs->rs_snd_bytes < rds_sk_sndbuf(rs)) {
722 rs->rs_snd_bytes += len;
723
724 /* let recv side know we are close to send space exhaustion.
725 * This is probably not the optimal way to do it, as this
726 * means we set the flag on *all* messages as soon as our
727 * throughput hits a certain threshold.
728 */
729 if (rs->rs_snd_bytes >= rds_sk_sndbuf(rs) / 2)
730 __set_bit(RDS_MSG_ACK_REQUIRED, &rm->m_flags);
731
732 list_add_tail(&rm->m_sock_item, &rs->rs_send_queue);
733 set_bit(RDS_MSG_ON_SOCK, &rm->m_flags);
734 rds_message_addref(rm);
735 rm->m_rs = rs;
736
737 /* The code ordering is a little weird, but we're
738 trying to minimize the time we hold c_lock */
739 rds_message_populate_header(&rm->m_inc.i_hdr, sport, dport, 0);
740 rm->m_inc.i_conn = conn;
741 rds_message_addref(rm);
742
743 spin_lock(&conn->c_lock);
744 rm->m_inc.i_hdr.h_sequence = cpu_to_be64(conn->c_next_tx_seq++);
745 list_add_tail(&rm->m_conn_item, &conn->c_send_queue);
746 set_bit(RDS_MSG_ON_CONN, &rm->m_flags);
747 spin_unlock(&conn->c_lock);
748
749 rdsdebug("queued msg %p len %d, rs %p bytes %d seq %llu\n",
750 rm, len, rs, rs->rs_snd_bytes,
751 (unsigned long long)be64_to_cpu(rm->m_inc.i_hdr.h_sequence));
752
753 *queued = 1;
754 }
755
756 spin_unlock_irqrestore(&rs->rs_lock, flags);
757out:
758 return *queued;
759}
760
Andy Groverfc445082010-01-12 12:56:06 -0800761/*
762 * rds_message is getting to be quite complicated, and we'd like to allocate
763 * it all in one go. This figures out how big it needs to be up front.
764 */
765static int rds_rm_size(struct msghdr *msg, int data_len)
766{
Andy Groverff87e972010-01-12 14:13:15 -0800767 struct cmsghdr *cmsg;
Andy Groverfc445082010-01-12 12:56:06 -0800768 int size = 0;
Andy Groverff87e972010-01-12 14:13:15 -0800769 int retval;
Andy Groverfc445082010-01-12 12:56:06 -0800770
Andy Groverff87e972010-01-12 14:13:15 -0800771 for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
772 if (!CMSG_OK(msg, cmsg))
773 return -EINVAL;
774
775 if (cmsg->cmsg_level != SOL_RDS)
776 continue;
777
778 switch (cmsg->cmsg_type) {
779 case RDS_CMSG_RDMA_ARGS:
780 retval = rds_rdma_extra_size(CMSG_DATA(cmsg));
781 if (retval < 0)
782 return retval;
783 size += retval;
784 break;
785
786 case RDS_CMSG_RDMA_DEST:
787 case RDS_CMSG_RDMA_MAP:
788 /* these are valid but do no add any size */
789 break;
790
791 default:
792 return -EINVAL;
793 }
794
795 }
796
797 size += ceil(data_len, PAGE_SIZE) * sizeof(struct scatterlist);
Andy Groverfc445082010-01-12 12:56:06 -0800798
799 return size;
800}
801
Andy Grover5c115592009-02-24 15:30:27 +0000802static int rds_cmsg_send(struct rds_sock *rs, struct rds_message *rm,
803 struct msghdr *msg, int *allocated_mr)
804{
805 struct cmsghdr *cmsg;
806 int ret = 0;
807
808 for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
809 if (!CMSG_OK(msg, cmsg))
810 return -EINVAL;
811
812 if (cmsg->cmsg_level != SOL_RDS)
813 continue;
814
815 /* As a side effect, RDMA_DEST and RDMA_MAP will set
816 * rm->m_rdma_cookie and rm->m_rdma_mr.
817 */
818 switch (cmsg->cmsg_type) {
819 case RDS_CMSG_RDMA_ARGS:
820 ret = rds_cmsg_rdma_args(rs, rm, cmsg);
821 break;
822
823 case RDS_CMSG_RDMA_DEST:
824 ret = rds_cmsg_rdma_dest(rs, rm, cmsg);
825 break;
826
827 case RDS_CMSG_RDMA_MAP:
828 ret = rds_cmsg_rdma_map(rs, rm, cmsg);
829 if (!ret)
830 *allocated_mr = 1;
831 break;
832
833 default:
834 return -EINVAL;
835 }
836
837 if (ret)
838 break;
839 }
840
841 return ret;
842}
843
844int rds_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
845 size_t payload_len)
846{
847 struct sock *sk = sock->sk;
848 struct rds_sock *rs = rds_sk_to_rs(sk);
849 struct sockaddr_in *usin = (struct sockaddr_in *)msg->msg_name;
850 __be32 daddr;
851 __be16 dport;
852 struct rds_message *rm = NULL;
853 struct rds_connection *conn;
854 int ret = 0;
855 int queued = 0, allocated_mr = 0;
856 int nonblock = msg->msg_flags & MSG_DONTWAIT;
Andy Grover1123fd72010-03-11 13:49:56 +0000857 long timeo = sock_sndtimeo(sk, nonblock);
Andy Grover5c115592009-02-24 15:30:27 +0000858
859 /* Mirror Linux UDP mirror of BSD error message compatibility */
860 /* XXX: Perhaps MSG_MORE someday */
861 if (msg->msg_flags & ~(MSG_DONTWAIT | MSG_CMSG_COMPAT)) {
862 printk(KERN_INFO "msg_flags 0x%08X\n", msg->msg_flags);
863 ret = -EOPNOTSUPP;
864 goto out;
865 }
866
867 if (msg->msg_namelen) {
868 /* XXX fail non-unicast destination IPs? */
869 if (msg->msg_namelen < sizeof(*usin) || usin->sin_family != AF_INET) {
870 ret = -EINVAL;
871 goto out;
872 }
873 daddr = usin->sin_addr.s_addr;
874 dport = usin->sin_port;
875 } else {
876 /* We only care about consistency with ->connect() */
877 lock_sock(sk);
878 daddr = rs->rs_conn_addr;
879 dport = rs->rs_conn_port;
880 release_sock(sk);
881 }
882
883 /* racing with another thread binding seems ok here */
884 if (daddr == 0 || rs->rs_bound_addr == 0) {
885 ret = -ENOTCONN; /* XXX not a great errno */
886 goto out;
887 }
888
Andy Groverfc445082010-01-12 12:56:06 -0800889 /* size of rm including all sgs */
890 ret = rds_rm_size(msg, payload_len);
891 if (ret < 0)
892 goto out;
893
894 rm = rds_message_alloc(ret, GFP_KERNEL);
895 if (!rm) {
896 ret = -ENOMEM;
Andy Grover5c115592009-02-24 15:30:27 +0000897 goto out;
898 }
899
Andy Groverfc445082010-01-12 12:56:06 -0800900 rm->data.m_sg = rds_message_alloc_sgs(rm, ceil(payload_len, PAGE_SIZE));
901 /* XXX fix this to not allocate memory */
902 ret = rds_message_copy_from_user(rm, msg->msg_iov, payload_len);
903 if (ret)
904 goto out;
905
Andy Grover5c115592009-02-24 15:30:27 +0000906 rm->m_daddr = daddr;
907
Andy Grover5c115592009-02-24 15:30:27 +0000908 /* rds_conn_create has a spinlock that runs with IRQ off.
909 * Caching the conn in the socket helps a lot. */
910 if (rs->rs_conn && rs->rs_conn->c_faddr == daddr)
911 conn = rs->rs_conn;
912 else {
913 conn = rds_conn_create_outgoing(rs->rs_bound_addr, daddr,
914 rs->rs_transport,
915 sock->sk->sk_allocation);
916 if (IS_ERR(conn)) {
917 ret = PTR_ERR(conn);
918 goto out;
919 }
920 rs->rs_conn = conn;
921 }
922
Andy Grover49f69692009-04-09 14:09:41 +0000923 /* Parse any control messages the user may have included. */
924 ret = rds_cmsg_send(rs, rm, msg, &allocated_mr);
925 if (ret)
926 goto out;
927
Andy Groverff87e972010-01-12 14:13:15 -0800928 if ((rm->m_rdma_cookie || rm->rdma.m_rdma_op.r_active) &&
Andy Grover8690bfa2010-01-12 11:56:44 -0800929 !conn->c_trans->xmit_rdma) {
Andy Grover5c115592009-02-24 15:30:27 +0000930 if (printk_ratelimit())
931 printk(KERN_NOTICE "rdma_op %p conn xmit_rdma %p\n",
Andy Groverff87e972010-01-12 14:13:15 -0800932 &rm->rdma.m_rdma_op, conn->c_trans->xmit_rdma);
Andy Grover5c115592009-02-24 15:30:27 +0000933 ret = -EOPNOTSUPP;
934 goto out;
935 }
936
937 /* If the connection is down, trigger a connect. We may
938 * have scheduled a delayed reconnect however - in this case
939 * we should not interfere.
940 */
Joe Perchesf64f9e72009-11-29 16:55:45 -0800941 if (rds_conn_state(conn) == RDS_CONN_DOWN &&
942 !test_and_set_bit(RDS_RECONNECT_PENDING, &conn->c_flags))
Andy Grover5c115592009-02-24 15:30:27 +0000943 queue_delayed_work(rds_wq, &conn->c_conn_w, 0);
944
945 ret = rds_cong_wait(conn->c_fcong, dport, nonblock, rs);
Andy Groverb98ba522010-03-11 13:50:04 +0000946 if (ret) {
947 rs->rs_seen_congestion = 1;
Andy Grover5c115592009-02-24 15:30:27 +0000948 goto out;
Andy Groverb98ba522010-03-11 13:50:04 +0000949 }
Andy Grover5c115592009-02-24 15:30:27 +0000950
951 while (!rds_send_queue_rm(rs, conn, rm, rs->rs_bound_port,
952 dport, &queued)) {
953 rds_stats_inc(s_send_queue_full);
954 /* XXX make sure this is reasonable */
955 if (payload_len > rds_sk_sndbuf(rs)) {
956 ret = -EMSGSIZE;
957 goto out;
958 }
959 if (nonblock) {
960 ret = -EAGAIN;
961 goto out;
962 }
963
Eric Dumazetaa395142010-04-20 13:03:51 +0000964 timeo = wait_event_interruptible_timeout(*sk_sleep(sk),
Andy Grover5c115592009-02-24 15:30:27 +0000965 rds_send_queue_rm(rs, conn, rm,
966 rs->rs_bound_port,
967 dport,
968 &queued),
969 timeo);
970 rdsdebug("sendmsg woke queued %d timeo %ld\n", queued, timeo);
971 if (timeo > 0 || timeo == MAX_SCHEDULE_TIMEOUT)
972 continue;
973
974 ret = timeo;
975 if (ret == 0)
976 ret = -ETIMEDOUT;
977 goto out;
978 }
979
980 /*
981 * By now we've committed to the send. We reuse rds_send_worker()
982 * to retry sends in the rds thread if the transport asks us to.
983 */
984 rds_stats_inc(s_send_queued);
985
986 if (!test_bit(RDS_LL_SEND_FULL, &conn->c_flags))
987 rds_send_worker(&conn->c_send_w.work);
988
989 rds_message_put(rm);
990 return payload_len;
991
992out:
993 /* If the user included a RDMA_MAP cmsg, we allocated a MR on the fly.
994 * If the sendmsg goes through, we keep the MR. If it fails with EAGAIN
995 * or in any other way, we need to destroy the MR again */
996 if (allocated_mr)
997 rds_rdma_unuse(rs, rds_rdma_cookie_key(rm->m_rdma_cookie), 1);
998
999 if (rm)
1000 rds_message_put(rm);
1001 return ret;
1002}
1003
1004/*
1005 * Reply to a ping packet.
1006 */
1007int
1008rds_send_pong(struct rds_connection *conn, __be16 dport)
1009{
1010 struct rds_message *rm;
1011 unsigned long flags;
1012 int ret = 0;
1013
1014 rm = rds_message_alloc(0, GFP_ATOMIC);
Andy Grover8690bfa2010-01-12 11:56:44 -08001015 if (!rm) {
Andy Grover5c115592009-02-24 15:30:27 +00001016 ret = -ENOMEM;
1017 goto out;
1018 }
1019
1020 rm->m_daddr = conn->c_faddr;
1021
1022 /* If the connection is down, trigger a connect. We may
1023 * have scheduled a delayed reconnect however - in this case
1024 * we should not interfere.
1025 */
Joe Perchesf64f9e72009-11-29 16:55:45 -08001026 if (rds_conn_state(conn) == RDS_CONN_DOWN &&
1027 !test_and_set_bit(RDS_RECONNECT_PENDING, &conn->c_flags))
Andy Grover5c115592009-02-24 15:30:27 +00001028 queue_delayed_work(rds_wq, &conn->c_conn_w, 0);
1029
1030 ret = rds_cong_wait(conn->c_fcong, dport, 1, NULL);
1031 if (ret)
1032 goto out;
1033
1034 spin_lock_irqsave(&conn->c_lock, flags);
1035 list_add_tail(&rm->m_conn_item, &conn->c_send_queue);
1036 set_bit(RDS_MSG_ON_CONN, &rm->m_flags);
1037 rds_message_addref(rm);
1038 rm->m_inc.i_conn = conn;
1039
1040 rds_message_populate_header(&rm->m_inc.i_hdr, 0, dport,
1041 conn->c_next_tx_seq);
1042 conn->c_next_tx_seq++;
1043 spin_unlock_irqrestore(&conn->c_lock, flags);
1044
1045 rds_stats_inc(s_send_queued);
1046 rds_stats_inc(s_send_pong);
1047
1048 queue_delayed_work(rds_wq, &conn->c_send_w, 0);
1049 rds_message_put(rm);
1050 return 0;
1051
1052out:
1053 if (rm)
1054 rds_message_put(rm);
1055 return ret;
1056}