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1/*
2 * Copyright (c) 2006, 2018 Oracle and/or its affiliates. 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>
34#include <linux/moduleparam.h>
35#include <linux/gfp.h>
36#include <net/sock.h>
37#include <linux/in.h>
38#include <linux/list.h>
39#include <linux/ratelimit.h>
40#include <linux/export.h>
41#include <linux/sizes.h>
42
43#include "rds.h"
44
45/* When transmitting messages in rds_send_xmit, we need to emerge from
46 * time to time and briefly release the CPU. Otherwise the softlock watchdog
47 * will kick our shin.
48 * Also, it seems fairer to not let one busy connection stall all the
49 * others.
50 *
51 * send_batch_count is the number of times we'll loop in send_xmit. Setting
52 * it to 0 will restore the old behavior (where we looped until we had
53 * drained the queue).
54 */
55static int send_batch_count = SZ_1K;
56module_param(send_batch_count, int, 0444);
57MODULE_PARM_DESC(send_batch_count, " batch factor when working the send queue");
58
59static void rds_send_remove_from_sock(struct list_head *messages, int status);
60
61/*
62 * Reset the send state. Callers must ensure that this doesn't race with
63 * rds_send_xmit().
64 */
65void rds_send_path_reset(struct rds_conn_path *cp)
66{
67 struct rds_message *rm, *tmp;
68 unsigned long flags;
69
70 if (cp->cp_xmit_rm) {
71 rm = cp->cp_xmit_rm;
72 cp->cp_xmit_rm = NULL;
73 /* Tell the user the RDMA op is no longer mapped by the
74 * transport. This isn't entirely true (it's flushed out
75 * independently) but as the connection is down, there's
76 * no ongoing RDMA to/from that memory */
77 rds_message_unmapped(rm);
78 rds_message_put(rm);
79 }
80
81 cp->cp_xmit_sg = 0;
82 cp->cp_xmit_hdr_off = 0;
83 cp->cp_xmit_data_off = 0;
84 cp->cp_xmit_atomic_sent = 0;
85 cp->cp_xmit_rdma_sent = 0;
86 cp->cp_xmit_data_sent = 0;
87
88 cp->cp_conn->c_map_queued = 0;
89
90 cp->cp_unacked_packets = rds_sysctl_max_unacked_packets;
91 cp->cp_unacked_bytes = rds_sysctl_max_unacked_bytes;
92
93 /* Mark messages as retransmissions, and move them to the send q */
94 spin_lock_irqsave(&cp->cp_lock, flags);
95 list_for_each_entry_safe(rm, tmp, &cp->cp_retrans, m_conn_item) {
96 set_bit(RDS_MSG_ACK_REQUIRED, &rm->m_flags);
97 set_bit(RDS_MSG_RETRANSMITTED, &rm->m_flags);
98 }
99 list_splice_init(&cp->cp_retrans, &cp->cp_send_queue);
100 spin_unlock_irqrestore(&cp->cp_lock, flags);
101}
102EXPORT_SYMBOL_GPL(rds_send_path_reset);
103
104static int acquire_in_xmit(struct rds_conn_path *cp)
105{
106 return test_and_set_bit(RDS_IN_XMIT, &cp->cp_flags) == 0;
107}
108
109static void release_in_xmit(struct rds_conn_path *cp)
110{
111 clear_bit(RDS_IN_XMIT, &cp->cp_flags);
112 smp_mb__after_atomic();
113 /*
114 * We don't use wait_on_bit()/wake_up_bit() because our waking is in a
115 * hot path and finding waiters is very rare. We don't want to walk
116 * the system-wide hashed waitqueue buckets in the fast path only to
117 * almost never find waiters.
118 */
119 if (waitqueue_active(&cp->cp_waitq))
120 wake_up_all(&cp->cp_waitq);
121}
122
123/*
124 * We're making the conscious trade-off here to only send one message
125 * down the connection at a time.
126 * Pro:
127 * - tx queueing is a simple fifo list
128 * - reassembly is optional and easily done by transports per conn
129 * - no per flow rx lookup at all, straight to the socket
130 * - less per-frag memory and wire overhead
131 * Con:
132 * - queued acks can be delayed behind large messages
133 * Depends:
134 * - small message latency is higher behind queued large messages
135 * - large message latency isn't starved by intervening small sends
136 */
137int rds_send_xmit(struct rds_conn_path *cp)
138{
139 struct rds_connection *conn = cp->cp_conn;
140 struct rds_message *rm;
141 unsigned long flags;
142 unsigned int tmp;
143 struct scatterlist *sg;
144 int ret = 0;
145 LIST_HEAD(to_be_dropped);
146 int batch_count;
147 unsigned long send_gen = 0;
148 int same_rm = 0;
149
150restart:
151 batch_count = 0;
152
153 /*
154 * sendmsg calls here after having queued its message on the send
155 * queue. We only have one task feeding the connection at a time. If
156 * another thread is already feeding the queue then we back off. This
157 * avoids blocking the caller and trading per-connection data between
158 * caches per message.
159 */
160 if (!acquire_in_xmit(cp)) {
161 rds_stats_inc(s_send_lock_contention);
162 ret = -ENOMEM;
163 goto out;
164 }
165
166 if (rds_destroy_pending(cp->cp_conn)) {
167 release_in_xmit(cp);
168 ret = -ENETUNREACH; /* dont requeue send work */
169 goto out;
170 }
171
172 /*
173 * we record the send generation after doing the xmit acquire.
174 * if someone else manages to jump in and do some work, we'll use
175 * this to avoid a goto restart farther down.
176 *
177 * The acquire_in_xmit() check above ensures that only one
178 * caller can increment c_send_gen at any time.
179 */
180 send_gen = READ_ONCE(cp->cp_send_gen) + 1;
181 WRITE_ONCE(cp->cp_send_gen, send_gen);
182
183 /*
184 * rds_conn_shutdown() sets the conn state and then tests RDS_IN_XMIT,
185 * we do the opposite to avoid races.
186 */
187 if (!rds_conn_path_up(cp)) {
188 release_in_xmit(cp);
189 ret = 0;
190 goto out;
191 }
192
193 if (conn->c_trans->xmit_path_prepare)
194 conn->c_trans->xmit_path_prepare(cp);
195
196 /*
197 * spin trying to push headers and data down the connection until
198 * the connection doesn't make forward progress.
199 */
200 while (1) {
201
202 rm = cp->cp_xmit_rm;
203
204 if (!rm) {
205 same_rm = 0;
206 } else {
207 same_rm++;
208 if (same_rm >= 4096) {
209 rds_stats_inc(s_send_stuck_rm);
210 ret = -EAGAIN;
211 break;
212 }
213 }
214
215 /*
216 * If between sending messages, we can send a pending congestion
217 * map update.
218 */
219 if (!rm && test_and_clear_bit(0, &conn->c_map_queued)) {
220 rm = rds_cong_update_alloc(conn);
221 if (IS_ERR(rm)) {
222 ret = PTR_ERR(rm);
223 break;
224 }
225 rm->data.op_active = 1;
226 rm->m_inc.i_conn_path = cp;
227 rm->m_inc.i_conn = cp->cp_conn;
228
229 cp->cp_xmit_rm = rm;
230 }
231
232 /*
233 * If not already working on one, grab the next message.
234 *
235 * cp_xmit_rm holds a ref while we're sending this message down
236 * the connction. We can use this ref while holding the
237 * send_sem.. rds_send_reset() is serialized with it.
238 */
239 if (!rm) {
240 unsigned int len;
241
242 batch_count++;
243
244 /* we want to process as big a batch as we can, but
245 * we also want to avoid softlockups. If we've been
246 * through a lot of messages, lets back off and see
247 * if anyone else jumps in
248 */
249 if (batch_count >= send_batch_count)
250 goto over_batch;
251
252 spin_lock_irqsave(&cp->cp_lock, flags);
253
254 if (!list_empty(&cp->cp_send_queue)) {
255 rm = list_entry(cp->cp_send_queue.next,
256 struct rds_message,
257 m_conn_item);
258 rds_message_addref(rm);
259
260 /*
261 * Move the message from the send queue to the retransmit
262 * list right away.
263 */
264 list_move_tail(&rm->m_conn_item,
265 &cp->cp_retrans);
266 }
267
268 spin_unlock_irqrestore(&cp->cp_lock, flags);
269
270 if (!rm)
271 break;
272
273 /* Unfortunately, the way Infiniband deals with
274 * RDMA to a bad MR key is by moving the entire
275 * queue pair to error state. We cold possibly
276 * recover from that, but right now we drop the
277 * connection.
278 * Therefore, we never retransmit messages with RDMA ops.
279 */
280 if (test_bit(RDS_MSG_FLUSH, &rm->m_flags) ||
281 (rm->rdma.op_active &&
282 test_bit(RDS_MSG_RETRANSMITTED, &rm->m_flags))) {
283 spin_lock_irqsave(&cp->cp_lock, flags);
284 if (test_and_clear_bit(RDS_MSG_ON_CONN, &rm->m_flags))
285 list_move(&rm->m_conn_item, &to_be_dropped);
286 spin_unlock_irqrestore(&cp->cp_lock, flags);
287 continue;
288 }
289
290 /* Require an ACK every once in a while */
291 len = ntohl(rm->m_inc.i_hdr.h_len);
292 if (cp->cp_unacked_packets == 0 ||
293 cp->cp_unacked_bytes < len) {
294 set_bit(RDS_MSG_ACK_REQUIRED, &rm->m_flags);
295
296 cp->cp_unacked_packets =
297 rds_sysctl_max_unacked_packets;
298 cp->cp_unacked_bytes =
299 rds_sysctl_max_unacked_bytes;
300 rds_stats_inc(s_send_ack_required);
301 } else {
302 cp->cp_unacked_bytes -= len;
303 cp->cp_unacked_packets--;
304 }
305
306 cp->cp_xmit_rm = rm;
307 }
308
309 /* The transport either sends the whole rdma or none of it */
310 if (rm->rdma.op_active && !cp->cp_xmit_rdma_sent) {
311 rm->m_final_op = &rm->rdma;
312 /* The transport owns the mapped memory for now.
313 * You can't unmap it while it's on the send queue
314 */
315 set_bit(RDS_MSG_MAPPED, &rm->m_flags);
316 ret = conn->c_trans->xmit_rdma(conn, &rm->rdma);
317 if (ret) {
318 clear_bit(RDS_MSG_MAPPED, &rm->m_flags);
319 wake_up_interruptible(&rm->m_flush_wait);
320 break;
321 }
322 cp->cp_xmit_rdma_sent = 1;
323
324 }
325
326 if (rm->atomic.op_active && !cp->cp_xmit_atomic_sent) {
327 rm->m_final_op = &rm->atomic;
328 /* The transport owns the mapped memory for now.
329 * You can't unmap it while it's on the send queue
330 */
331 set_bit(RDS_MSG_MAPPED, &rm->m_flags);
332 ret = conn->c_trans->xmit_atomic(conn, &rm->atomic);
333 if (ret) {
334 clear_bit(RDS_MSG_MAPPED, &rm->m_flags);
335 wake_up_interruptible(&rm->m_flush_wait);
336 break;
337 }
338 cp->cp_xmit_atomic_sent = 1;
339
340 }
341
342 /*
343 * A number of cases require an RDS header to be sent
344 * even if there is no data.
345 * We permit 0-byte sends; rds-ping depends on this.
346 * However, if there are exclusively attached silent ops,
347 * we skip the hdr/data send, to enable silent operation.
348 */
349 if (rm->data.op_nents == 0) {
350 int ops_present;
351 int all_ops_are_silent = 1;
352
353 ops_present = (rm->atomic.op_active || rm->rdma.op_active);
354 if (rm->atomic.op_active && !rm->atomic.op_silent)
355 all_ops_are_silent = 0;
356 if (rm->rdma.op_active && !rm->rdma.op_silent)
357 all_ops_are_silent = 0;
358
359 if (ops_present && all_ops_are_silent
360 && !rm->m_rdma_cookie)
361 rm->data.op_active = 0;
362 }
363
364 if (rm->data.op_active && !cp->cp_xmit_data_sent) {
365 rm->m_final_op = &rm->data;
366
367 ret = conn->c_trans->xmit(conn, rm,
368 cp->cp_xmit_hdr_off,
369 cp->cp_xmit_sg,
370 cp->cp_xmit_data_off);
371 if (ret <= 0)
372 break;
373
374 if (cp->cp_xmit_hdr_off < sizeof(struct rds_header)) {
375 tmp = min_t(int, ret,
376 sizeof(struct rds_header) -
377 cp->cp_xmit_hdr_off);
378 cp->cp_xmit_hdr_off += tmp;
379 ret -= tmp;
380 }
381
382 sg = &rm->data.op_sg[cp->cp_xmit_sg];
383 while (ret) {
384 tmp = min_t(int, ret, sg->length -
385 cp->cp_xmit_data_off);
386 cp->cp_xmit_data_off += tmp;
387 ret -= tmp;
388 if (cp->cp_xmit_data_off == sg->length) {
389 cp->cp_xmit_data_off = 0;
390 sg++;
391 cp->cp_xmit_sg++;
392 BUG_ON(ret != 0 && cp->cp_xmit_sg ==
393 rm->data.op_nents);
394 }
395 }
396
397 if (cp->cp_xmit_hdr_off == sizeof(struct rds_header) &&
398 (cp->cp_xmit_sg == rm->data.op_nents))
399 cp->cp_xmit_data_sent = 1;
400 }
401
402 /*
403 * A rm will only take multiple times through this loop
404 * if there is a data op. Thus, if the data is sent (or there was
405 * none), then we're done with the rm.
406 */
407 if (!rm->data.op_active || cp->cp_xmit_data_sent) {
408 cp->cp_xmit_rm = NULL;
409 cp->cp_xmit_sg = 0;
410 cp->cp_xmit_hdr_off = 0;
411 cp->cp_xmit_data_off = 0;
412 cp->cp_xmit_rdma_sent = 0;
413 cp->cp_xmit_atomic_sent = 0;
414 cp->cp_xmit_data_sent = 0;
415
416 rds_message_put(rm);
417 }
418 }
419
420over_batch:
421 if (conn->c_trans->xmit_path_complete)
422 conn->c_trans->xmit_path_complete(cp);
423 release_in_xmit(cp);
424
425 /* Nuke any messages we decided not to retransmit. */
426 if (!list_empty(&to_be_dropped)) {
427 /* irqs on here, so we can put(), unlike above */
428 list_for_each_entry(rm, &to_be_dropped, m_conn_item)
429 rds_message_put(rm);
430 rds_send_remove_from_sock(&to_be_dropped, RDS_RDMA_DROPPED);
431 }
432
433 /*
434 * Other senders can queue a message after we last test the send queue
435 * but before we clear RDS_IN_XMIT. In that case they'd back off and
436 * not try and send their newly queued message. We need to check the
437 * send queue after having cleared RDS_IN_XMIT so that their message
438 * doesn't get stuck on the send queue.
439 *
440 * If the transport cannot continue (i.e ret != 0), then it must
441 * call us when more room is available, such as from the tx
442 * completion handler.
443 *
444 * We have an extra generation check here so that if someone manages
445 * to jump in after our release_in_xmit, we'll see that they have done
446 * some work and we will skip our goto
447 */
448 if (ret == 0) {
449 bool raced;
450
451 smp_mb();
452 raced = send_gen != READ_ONCE(cp->cp_send_gen);
453
454 if ((test_bit(0, &conn->c_map_queued) ||
455 !list_empty(&cp->cp_send_queue)) && !raced) {
456 if (batch_count < send_batch_count)
457 goto restart;
458 rcu_read_lock();
459 if (rds_destroy_pending(cp->cp_conn))
460 ret = -ENETUNREACH;
461 else
462 queue_delayed_work(rds_wq, &cp->cp_send_w, 1);
463 rcu_read_unlock();
464 } else if (raced) {
465 rds_stats_inc(s_send_lock_queue_raced);
466 }
467 }
468out:
469 return ret;
470}
471EXPORT_SYMBOL_GPL(rds_send_xmit);
472
473static void rds_send_sndbuf_remove(struct rds_sock *rs, struct rds_message *rm)
474{
475 u32 len = be32_to_cpu(rm->m_inc.i_hdr.h_len);
476
477 assert_spin_locked(&rs->rs_lock);
478
479 BUG_ON(rs->rs_snd_bytes < len);
480 rs->rs_snd_bytes -= len;
481
482 if (rs->rs_snd_bytes == 0)
483 rds_stats_inc(s_send_queue_empty);
484}
485
486static inline int rds_send_is_acked(struct rds_message *rm, u64 ack,
487 is_acked_func is_acked)
488{
489 if (is_acked)
490 return is_acked(rm, ack);
491 return be64_to_cpu(rm->m_inc.i_hdr.h_sequence) <= ack;
492}
493
494/*
495 * This is pretty similar to what happens below in the ACK
496 * handling code - except that we call here as soon as we get
497 * the IB send completion on the RDMA op and the accompanying
498 * message.
499 */
500void rds_rdma_send_complete(struct rds_message *rm, int status)
501{
502 struct rds_sock *rs = NULL;
503 struct rm_rdma_op *ro;
504 struct rds_notifier *notifier;
505 unsigned long flags;
506
507 spin_lock_irqsave(&rm->m_rs_lock, flags);
508
509 ro = &rm->rdma;
510 if (test_bit(RDS_MSG_ON_SOCK, &rm->m_flags) &&
511 ro->op_active && ro->op_notify && ro->op_notifier) {
512 notifier = ro->op_notifier;
513 rs = rm->m_rs;
514 sock_hold(rds_rs_to_sk(rs));
515
516 notifier->n_status = status;
517 spin_lock(&rs->rs_lock);
518 list_add_tail(¬ifier->n_list, &rs->rs_notify_queue);
519 spin_unlock(&rs->rs_lock);
520
521 ro->op_notifier = NULL;
522 }
523
524 spin_unlock_irqrestore(&rm->m_rs_lock, flags);
525
526 if (rs) {
527 rds_wake_sk_sleep(rs);
528 sock_put(rds_rs_to_sk(rs));
529 }
530}
531EXPORT_SYMBOL_GPL(rds_rdma_send_complete);
532
533/*
534 * Just like above, except looks at atomic op
535 */
536void rds_atomic_send_complete(struct rds_message *rm, int status)
537{
538 struct rds_sock *rs = NULL;
539 struct rm_atomic_op *ao;
540 struct rds_notifier *notifier;
541 unsigned long flags;
542
543 spin_lock_irqsave(&rm->m_rs_lock, flags);
544
545 ao = &rm->atomic;
546 if (test_bit(RDS_MSG_ON_SOCK, &rm->m_flags)
547 && ao->op_active && ao->op_notify && ao->op_notifier) {
548 notifier = ao->op_notifier;
549 rs = rm->m_rs;
550 sock_hold(rds_rs_to_sk(rs));
551
552 notifier->n_status = status;
553 spin_lock(&rs->rs_lock);
554 list_add_tail(¬ifier->n_list, &rs->rs_notify_queue);
555 spin_unlock(&rs->rs_lock);
556
557 ao->op_notifier = NULL;
558 }
559
560 spin_unlock_irqrestore(&rm->m_rs_lock, flags);
561
562 if (rs) {
563 rds_wake_sk_sleep(rs);
564 sock_put(rds_rs_to_sk(rs));
565 }
566}
567EXPORT_SYMBOL_GPL(rds_atomic_send_complete);
568
569/*
570 * This is the same as rds_rdma_send_complete except we
571 * don't do any locking - we have all the ingredients (message,
572 * socket, socket lock) and can just move the notifier.
573 */
574static inline void
575__rds_send_complete(struct rds_sock *rs, struct rds_message *rm, int status)
576{
577 struct rm_rdma_op *ro;
578 struct rm_atomic_op *ao;
579
580 ro = &rm->rdma;
581 if (ro->op_active && ro->op_notify && ro->op_notifier) {
582 ro->op_notifier->n_status = status;
583 list_add_tail(&ro->op_notifier->n_list, &rs->rs_notify_queue);
584 ro->op_notifier = NULL;
585 }
586
587 ao = &rm->atomic;
588 if (ao->op_active && ao->op_notify && ao->op_notifier) {
589 ao->op_notifier->n_status = status;
590 list_add_tail(&ao->op_notifier->n_list, &rs->rs_notify_queue);
591 ao->op_notifier = NULL;
592 }
593
594 /* No need to wake the app - caller does this */
595}
596
597/*
598 * This removes messages from the socket's list if they're on it. The list
599 * argument must be private to the caller, we must be able to modify it
600 * without locks. The messages must have a reference held for their
601 * position on the list. This function will drop that reference after
602 * removing the messages from the 'messages' list regardless of if it found
603 * the messages on the socket list or not.
604 */
605static void rds_send_remove_from_sock(struct list_head *messages, int status)
606{
607 unsigned long flags;
608 struct rds_sock *rs = NULL;
609 struct rds_message *rm;
610
611 while (!list_empty(messages)) {
612 int was_on_sock = 0;
613
614 rm = list_entry(messages->next, struct rds_message,
615 m_conn_item);
616 list_del_init(&rm->m_conn_item);
617
618 /*
619 * If we see this flag cleared then we're *sure* that someone
620 * else beat us to removing it from the sock. If we race
621 * with their flag update we'll get the lock and then really
622 * see that the flag has been cleared.
623 *
624 * The message spinlock makes sure nobody clears rm->m_rs
625 * while we're messing with it. It does not prevent the
626 * message from being removed from the socket, though.
627 */
628 spin_lock_irqsave(&rm->m_rs_lock, flags);
629 if (!test_bit(RDS_MSG_ON_SOCK, &rm->m_flags))
630 goto unlock_and_drop;
631
632 if (rs != rm->m_rs) {
633 if (rs) {
634 rds_wake_sk_sleep(rs);
635 sock_put(rds_rs_to_sk(rs));
636 }
637 rs = rm->m_rs;
638 if (rs)
639 sock_hold(rds_rs_to_sk(rs));
640 }
641 if (!rs)
642 goto unlock_and_drop;
643 spin_lock(&rs->rs_lock);
644
645 if (test_and_clear_bit(RDS_MSG_ON_SOCK, &rm->m_flags)) {
646 struct rm_rdma_op *ro = &rm->rdma;
647 struct rds_notifier *notifier;
648
649 list_del_init(&rm->m_sock_item);
650 rds_send_sndbuf_remove(rs, rm);
651
652 if (ro->op_active && ro->op_notifier &&
653 (ro->op_notify || (ro->op_recverr && status))) {
654 notifier = ro->op_notifier;
655 list_add_tail(¬ifier->n_list,
656 &rs->rs_notify_queue);
657 if (!notifier->n_status)
658 notifier->n_status = status;
659 rm->rdma.op_notifier = NULL;
660 }
661 was_on_sock = 1;
662 }
663 spin_unlock(&rs->rs_lock);
664
665unlock_and_drop:
666 spin_unlock_irqrestore(&rm->m_rs_lock, flags);
667 rds_message_put(rm);
668 if (was_on_sock)
669 rds_message_put(rm);
670 }
671
672 if (rs) {
673 rds_wake_sk_sleep(rs);
674 sock_put(rds_rs_to_sk(rs));
675 }
676}
677
678/*
679 * Transports call here when they've determined that the receiver queued
680 * messages up to, and including, the given sequence number. Messages are
681 * moved to the retrans queue when rds_send_xmit picks them off the send
682 * queue. This means that in the TCP case, the message may not have been
683 * assigned the m_ack_seq yet - but that's fine as long as tcp_is_acked
684 * checks the RDS_MSG_HAS_ACK_SEQ bit.
685 */
686void rds_send_path_drop_acked(struct rds_conn_path *cp, u64 ack,
687 is_acked_func is_acked)
688{
689 struct rds_message *rm, *tmp;
690 unsigned long flags;
691 LIST_HEAD(list);
692
693 spin_lock_irqsave(&cp->cp_lock, flags);
694
695 list_for_each_entry_safe(rm, tmp, &cp->cp_retrans, m_conn_item) {
696 if (!rds_send_is_acked(rm, ack, is_acked))
697 break;
698
699 list_move(&rm->m_conn_item, &list);
700 clear_bit(RDS_MSG_ON_CONN, &rm->m_flags);
701 }
702
703 /* order flag updates with spin locks */
704 if (!list_empty(&list))
705 smp_mb__after_atomic();
706
707 spin_unlock_irqrestore(&cp->cp_lock, flags);
708
709 /* now remove the messages from the sock list as needed */
710 rds_send_remove_from_sock(&list, RDS_RDMA_SUCCESS);
711}
712EXPORT_SYMBOL_GPL(rds_send_path_drop_acked);
713
714void rds_send_drop_acked(struct rds_connection *conn, u64 ack,
715 is_acked_func is_acked)
716{
717 WARN_ON(conn->c_trans->t_mp_capable);
718 rds_send_path_drop_acked(&conn->c_path[0], ack, is_acked);
719}
720EXPORT_SYMBOL_GPL(rds_send_drop_acked);
721
722void rds_send_drop_to(struct rds_sock *rs, struct sockaddr_in6 *dest)
723{
724 struct rds_message *rm, *tmp;
725 struct rds_connection *conn;
726 struct rds_conn_path *cp;
727 unsigned long flags;
728 LIST_HEAD(list);
729
730 /* get all the messages we're dropping under the rs lock */
731 spin_lock_irqsave(&rs->rs_lock, flags);
732
733 list_for_each_entry_safe(rm, tmp, &rs->rs_send_queue, m_sock_item) {
734 if (dest &&
735 (!ipv6_addr_equal(&dest->sin6_addr, &rm->m_daddr) ||
736 dest->sin6_port != rm->m_inc.i_hdr.h_dport))
737 continue;
738
739 list_move(&rm->m_sock_item, &list);
740 rds_send_sndbuf_remove(rs, rm);
741 clear_bit(RDS_MSG_ON_SOCK, &rm->m_flags);
742 }
743
744 /* order flag updates with the rs lock */
745 smp_mb__after_atomic();
746
747 spin_unlock_irqrestore(&rs->rs_lock, flags);
748
749 if (list_empty(&list))
750 return;
751
752 /* Remove the messages from the conn */
753 list_for_each_entry(rm, &list, m_sock_item) {
754
755 conn = rm->m_inc.i_conn;
756 if (conn->c_trans->t_mp_capable)
757 cp = rm->m_inc.i_conn_path;
758 else
759 cp = &conn->c_path[0];
760
761 spin_lock_irqsave(&cp->cp_lock, flags);
762 /*
763 * Maybe someone else beat us to removing rm from the conn.
764 * If we race with their flag update we'll get the lock and
765 * then really see that the flag has been cleared.
766 */
767 if (!test_and_clear_bit(RDS_MSG_ON_CONN, &rm->m_flags)) {
768 spin_unlock_irqrestore(&cp->cp_lock, flags);
769 continue;
770 }
771 list_del_init(&rm->m_conn_item);
772 spin_unlock_irqrestore(&cp->cp_lock, flags);
773
774 /*
775 * Couldn't grab m_rs_lock in top loop (lock ordering),
776 * but we can now.
777 */
778 spin_lock_irqsave(&rm->m_rs_lock, flags);
779
780 spin_lock(&rs->rs_lock);
781 __rds_send_complete(rs, rm, RDS_RDMA_CANCELED);
782 spin_unlock(&rs->rs_lock);
783
784 spin_unlock_irqrestore(&rm->m_rs_lock, flags);
785
786 rds_message_put(rm);
787 }
788
789 rds_wake_sk_sleep(rs);
790
791 while (!list_empty(&list)) {
792 rm = list_entry(list.next, struct rds_message, m_sock_item);
793 list_del_init(&rm->m_sock_item);
794 rds_message_wait(rm);
795
796 /* just in case the code above skipped this message
797 * because RDS_MSG_ON_CONN wasn't set, run it again here
798 * taking m_rs_lock is the only thing that keeps us
799 * from racing with ack processing.
800 */
801 spin_lock_irqsave(&rm->m_rs_lock, flags);
802
803 spin_lock(&rs->rs_lock);
804 __rds_send_complete(rs, rm, RDS_RDMA_CANCELED);
805 spin_unlock(&rs->rs_lock);
806
807 spin_unlock_irqrestore(&rm->m_rs_lock, flags);
808
809 rds_message_put(rm);
810 }
811}
812
813/*
814 * we only want this to fire once so we use the callers 'queued'. It's
815 * possible that another thread can race with us and remove the
816 * message from the flow with RDS_CANCEL_SENT_TO.
817 */
818static int rds_send_queue_rm(struct rds_sock *rs, struct rds_connection *conn,
819 struct rds_conn_path *cp,
820 struct rds_message *rm, __be16 sport,
821 __be16 dport, int *queued)
822{
823 unsigned long flags;
824 u32 len;
825
826 if (*queued)
827 goto out;
828
829 len = be32_to_cpu(rm->m_inc.i_hdr.h_len);
830
831 /* this is the only place which holds both the socket's rs_lock
832 * and the connection's c_lock */
833 spin_lock_irqsave(&rs->rs_lock, flags);
834
835 /*
836 * If there is a little space in sndbuf, we don't queue anything,
837 * and userspace gets -EAGAIN. But poll() indicates there's send
838 * room. This can lead to bad behavior (spinning) if snd_bytes isn't
839 * freed up by incoming acks. So we check the *old* value of
840 * rs_snd_bytes here to allow the last msg to exceed the buffer,
841 * and poll() now knows no more data can be sent.
842 */
843 if (rs->rs_snd_bytes < rds_sk_sndbuf(rs)) {
844 rs->rs_snd_bytes += len;
845
846 /* let recv side know we are close to send space exhaustion.
847 * This is probably not the optimal way to do it, as this
848 * means we set the flag on *all* messages as soon as our
849 * throughput hits a certain threshold.
850 */
851 if (rs->rs_snd_bytes >= rds_sk_sndbuf(rs) / 2)
852 set_bit(RDS_MSG_ACK_REQUIRED, &rm->m_flags);
853
854 list_add_tail(&rm->m_sock_item, &rs->rs_send_queue);
855 set_bit(RDS_MSG_ON_SOCK, &rm->m_flags);
856 rds_message_addref(rm);
857 sock_hold(rds_rs_to_sk(rs));
858 rm->m_rs = rs;
859
860 /* The code ordering is a little weird, but we're
861 trying to minimize the time we hold c_lock */
862 rds_message_populate_header(&rm->m_inc.i_hdr, sport, dport, 0);
863 rm->m_inc.i_conn = conn;
864 rm->m_inc.i_conn_path = cp;
865 rds_message_addref(rm);
866
867 spin_lock(&cp->cp_lock);
868 rm->m_inc.i_hdr.h_sequence = cpu_to_be64(cp->cp_next_tx_seq++);
869 list_add_tail(&rm->m_conn_item, &cp->cp_send_queue);
870 set_bit(RDS_MSG_ON_CONN, &rm->m_flags);
871 spin_unlock(&cp->cp_lock);
872
873 rdsdebug("queued msg %p len %d, rs %p bytes %d seq %llu\n",
874 rm, len, rs, rs->rs_snd_bytes,
875 (unsigned long long)be64_to_cpu(rm->m_inc.i_hdr.h_sequence));
876
877 *queued = 1;
878 }
879
880 spin_unlock_irqrestore(&rs->rs_lock, flags);
881out:
882 return *queued;
883}
884
885/*
886 * rds_message is getting to be quite complicated, and we'd like to allocate
887 * it all in one go. This figures out how big it needs to be up front.
888 */
889static int rds_rm_size(struct msghdr *msg, int num_sgs,
890 struct rds_iov_vector_arr *vct)
891{
892 struct cmsghdr *cmsg;
893 int size = 0;
894 int cmsg_groups = 0;
895 int retval;
896 bool zcopy_cookie = false;
897 struct rds_iov_vector *iov, *tmp_iov;
898
899 if (num_sgs < 0)
900 return -EINVAL;
901
902 for_each_cmsghdr(cmsg, msg) {
903 if (!CMSG_OK(msg, cmsg))
904 return -EINVAL;
905
906 if (cmsg->cmsg_level != SOL_RDS)
907 continue;
908
909 switch (cmsg->cmsg_type) {
910 case RDS_CMSG_RDMA_ARGS:
911 if (vct->indx >= vct->len) {
912 vct->len += vct->incr;
913 tmp_iov =
914 krealloc(vct->vec,
915 vct->len *
916 sizeof(struct rds_iov_vector),
917 GFP_KERNEL);
918 if (!tmp_iov) {
919 vct->len -= vct->incr;
920 return -ENOMEM;
921 }
922 vct->vec = tmp_iov;
923 }
924 iov = &vct->vec[vct->indx];
925 memset(iov, 0, sizeof(struct rds_iov_vector));
926 vct->indx++;
927 cmsg_groups |= 1;
928 retval = rds_rdma_extra_size(CMSG_DATA(cmsg), iov);
929 if (retval < 0)
930 return retval;
931 size += retval;
932
933 break;
934
935 case RDS_CMSG_ZCOPY_COOKIE:
936 zcopy_cookie = true;
937 fallthrough;
938
939 case RDS_CMSG_RDMA_DEST:
940 case RDS_CMSG_RDMA_MAP:
941 cmsg_groups |= 2;
942 /* these are valid but do no add any size */
943 break;
944
945 case RDS_CMSG_ATOMIC_CSWP:
946 case RDS_CMSG_ATOMIC_FADD:
947 case RDS_CMSG_MASKED_ATOMIC_CSWP:
948 case RDS_CMSG_MASKED_ATOMIC_FADD:
949 cmsg_groups |= 1;
950 size += sizeof(struct scatterlist);
951 break;
952
953 default:
954 return -EINVAL;
955 }
956
957 }
958
959 if ((msg->msg_flags & MSG_ZEROCOPY) && !zcopy_cookie)
960 return -EINVAL;
961
962 size += num_sgs * sizeof(struct scatterlist);
963
964 /* Ensure (DEST, MAP) are never used with (ARGS, ATOMIC) */
965 if (cmsg_groups == 3)
966 return -EINVAL;
967
968 return size;
969}
970
971static int rds_cmsg_zcopy(struct rds_sock *rs, struct rds_message *rm,
972 struct cmsghdr *cmsg)
973{
974 u32 *cookie;
975
976 if (cmsg->cmsg_len < CMSG_LEN(sizeof(*cookie)) ||
977 !rm->data.op_mmp_znotifier)
978 return -EINVAL;
979 cookie = CMSG_DATA(cmsg);
980 rm->data.op_mmp_znotifier->z_cookie = *cookie;
981 return 0;
982}
983
984static int rds_cmsg_send(struct rds_sock *rs, struct rds_message *rm,
985 struct msghdr *msg, int *allocated_mr,
986 struct rds_iov_vector_arr *vct)
987{
988 struct cmsghdr *cmsg;
989 int ret = 0, ind = 0;
990
991 for_each_cmsghdr(cmsg, msg) {
992 if (!CMSG_OK(msg, cmsg))
993 return -EINVAL;
994
995 if (cmsg->cmsg_level != SOL_RDS)
996 continue;
997
998 /* As a side effect, RDMA_DEST and RDMA_MAP will set
999 * rm->rdma.m_rdma_cookie and rm->rdma.m_rdma_mr.
1000 */
1001 switch (cmsg->cmsg_type) {
1002 case RDS_CMSG_RDMA_ARGS:
1003 if (ind >= vct->indx)
1004 return -ENOMEM;
1005 ret = rds_cmsg_rdma_args(rs, rm, cmsg, &vct->vec[ind]);
1006 ind++;
1007 break;
1008
1009 case RDS_CMSG_RDMA_DEST:
1010 ret = rds_cmsg_rdma_dest(rs, rm, cmsg);
1011 break;
1012
1013 case RDS_CMSG_RDMA_MAP:
1014 ret = rds_cmsg_rdma_map(rs, rm, cmsg);
1015 if (!ret)
1016 *allocated_mr = 1;
1017 else if (ret == -ENODEV)
1018 /* Accommodate the get_mr() case which can fail
1019 * if connection isn't established yet.
1020 */
1021 ret = -EAGAIN;
1022 break;
1023 case RDS_CMSG_ATOMIC_CSWP:
1024 case RDS_CMSG_ATOMIC_FADD:
1025 case RDS_CMSG_MASKED_ATOMIC_CSWP:
1026 case RDS_CMSG_MASKED_ATOMIC_FADD:
1027 ret = rds_cmsg_atomic(rs, rm, cmsg);
1028 break;
1029
1030 case RDS_CMSG_ZCOPY_COOKIE:
1031 ret = rds_cmsg_zcopy(rs, rm, cmsg);
1032 break;
1033
1034 default:
1035 return -EINVAL;
1036 }
1037
1038 if (ret)
1039 break;
1040 }
1041
1042 return ret;
1043}
1044
1045static int rds_send_mprds_hash(struct rds_sock *rs,
1046 struct rds_connection *conn, int nonblock)
1047{
1048 int hash;
1049
1050 if (conn->c_npaths == 0)
1051 hash = RDS_MPATH_HASH(rs, RDS_MPATH_WORKERS);
1052 else
1053 hash = RDS_MPATH_HASH(rs, conn->c_npaths);
1054 if (conn->c_npaths == 0 && hash != 0) {
1055 rds_send_ping(conn, 0);
1056
1057 /* The underlying connection is not up yet. Need to wait
1058 * until it is up to be sure that the non-zero c_path can be
1059 * used. But if we are interrupted, we have to use the zero
1060 * c_path in case the connection ends up being non-MP capable.
1061 */
1062 if (conn->c_npaths == 0) {
1063 /* Cannot wait for the connection be made, so just use
1064 * the base c_path.
1065 */
1066 if (nonblock)
1067 return 0;
1068 if (wait_event_interruptible(conn->c_hs_waitq,
1069 conn->c_npaths != 0))
1070 hash = 0;
1071 }
1072 if (conn->c_npaths == 1)
1073 hash = 0;
1074 }
1075 return hash;
1076}
1077
1078static int rds_rdma_bytes(struct msghdr *msg, size_t *rdma_bytes)
1079{
1080 struct rds_rdma_args *args;
1081 struct cmsghdr *cmsg;
1082
1083 for_each_cmsghdr(cmsg, msg) {
1084 if (!CMSG_OK(msg, cmsg))
1085 return -EINVAL;
1086
1087 if (cmsg->cmsg_level != SOL_RDS)
1088 continue;
1089
1090 if (cmsg->cmsg_type == RDS_CMSG_RDMA_ARGS) {
1091 if (cmsg->cmsg_len <
1092 CMSG_LEN(sizeof(struct rds_rdma_args)))
1093 return -EINVAL;
1094 args = CMSG_DATA(cmsg);
1095 *rdma_bytes += args->remote_vec.bytes;
1096 }
1097 }
1098 return 0;
1099}
1100
1101int rds_sendmsg(struct socket *sock, struct msghdr *msg, size_t payload_len)
1102{
1103 struct sock *sk = sock->sk;
1104 struct rds_sock *rs = rds_sk_to_rs(sk);
1105 DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
1106 DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name);
1107 __be16 dport;
1108 struct rds_message *rm = NULL;
1109 struct rds_connection *conn;
1110 int ret = 0;
1111 int queued = 0, allocated_mr = 0;
1112 int nonblock = msg->msg_flags & MSG_DONTWAIT;
1113 long timeo = sock_sndtimeo(sk, nonblock);
1114 struct rds_conn_path *cpath;
1115 struct in6_addr daddr;
1116 __u32 scope_id = 0;
1117 size_t total_payload_len = payload_len, rdma_payload_len = 0;
1118 bool zcopy = ((msg->msg_flags & MSG_ZEROCOPY) &&
1119 sock_flag(rds_rs_to_sk(rs), SOCK_ZEROCOPY));
1120 int num_sgs = DIV_ROUND_UP(payload_len, PAGE_SIZE);
1121 int namelen;
1122 struct rds_iov_vector_arr vct;
1123 int ind;
1124
1125 memset(&vct, 0, sizeof(vct));
1126
1127 /* expect 1 RDMA CMSG per rds_sendmsg. can still grow if more needed. */
1128 vct.incr = 1;
1129
1130 /* Mirror Linux UDP mirror of BSD error message compatibility */
1131 /* XXX: Perhaps MSG_MORE someday */
1132 if (msg->msg_flags & ~(MSG_DONTWAIT | MSG_CMSG_COMPAT | MSG_ZEROCOPY)) {
1133 ret = -EOPNOTSUPP;
1134 goto out;
1135 }
1136
1137 namelen = msg->msg_namelen;
1138 if (namelen != 0) {
1139 if (namelen < sizeof(*usin)) {
1140 ret = -EINVAL;
1141 goto out;
1142 }
1143 switch (usin->sin_family) {
1144 case AF_INET:
1145 if (usin->sin_addr.s_addr == htonl(INADDR_ANY) ||
1146 usin->sin_addr.s_addr == htonl(INADDR_BROADCAST) ||
1147 ipv4_is_multicast(usin->sin_addr.s_addr)) {
1148 ret = -EINVAL;
1149 goto out;
1150 }
1151 ipv6_addr_set_v4mapped(usin->sin_addr.s_addr, &daddr);
1152 dport = usin->sin_port;
1153 break;
1154
1155#if IS_ENABLED(CONFIG_IPV6)
1156 case AF_INET6: {
1157 int addr_type;
1158
1159 if (namelen < sizeof(*sin6)) {
1160 ret = -EINVAL;
1161 goto out;
1162 }
1163 addr_type = ipv6_addr_type(&sin6->sin6_addr);
1164 if (!(addr_type & IPV6_ADDR_UNICAST)) {
1165 __be32 addr4;
1166
1167 if (!(addr_type & IPV6_ADDR_MAPPED)) {
1168 ret = -EINVAL;
1169 goto out;
1170 }
1171
1172 /* It is a mapped address. Need to do some
1173 * sanity checks.
1174 */
1175 addr4 = sin6->sin6_addr.s6_addr32[3];
1176 if (addr4 == htonl(INADDR_ANY) ||
1177 addr4 == htonl(INADDR_BROADCAST) ||
1178 ipv4_is_multicast(addr4)) {
1179 ret = -EINVAL;
1180 goto out;
1181 }
1182 }
1183 if (addr_type & IPV6_ADDR_LINKLOCAL) {
1184 if (sin6->sin6_scope_id == 0) {
1185 ret = -EINVAL;
1186 goto out;
1187 }
1188 scope_id = sin6->sin6_scope_id;
1189 }
1190
1191 daddr = sin6->sin6_addr;
1192 dport = sin6->sin6_port;
1193 break;
1194 }
1195#endif
1196
1197 default:
1198 ret = -EINVAL;
1199 goto out;
1200 }
1201 } else {
1202 /* We only care about consistency with ->connect() */
1203 lock_sock(sk);
1204 daddr = rs->rs_conn_addr;
1205 dport = rs->rs_conn_port;
1206 scope_id = rs->rs_bound_scope_id;
1207 release_sock(sk);
1208 }
1209
1210 lock_sock(sk);
1211 if (ipv6_addr_any(&rs->rs_bound_addr) || ipv6_addr_any(&daddr)) {
1212 release_sock(sk);
1213 ret = -ENOTCONN;
1214 goto out;
1215 } else if (namelen != 0) {
1216 /* Cannot send to an IPv4 address using an IPv6 source
1217 * address and cannot send to an IPv6 address using an
1218 * IPv4 source address.
1219 */
1220 if (ipv6_addr_v4mapped(&daddr) ^
1221 ipv6_addr_v4mapped(&rs->rs_bound_addr)) {
1222 release_sock(sk);
1223 ret = -EOPNOTSUPP;
1224 goto out;
1225 }
1226 /* If the socket is already bound to a link local address,
1227 * it can only send to peers on the same link. But allow
1228 * communicating beween link local and non-link local address.
1229 */
1230 if (scope_id != rs->rs_bound_scope_id) {
1231 if (!scope_id) {
1232 scope_id = rs->rs_bound_scope_id;
1233 } else if (rs->rs_bound_scope_id) {
1234 release_sock(sk);
1235 ret = -EINVAL;
1236 goto out;
1237 }
1238 }
1239 }
1240 release_sock(sk);
1241
1242 ret = rds_rdma_bytes(msg, &rdma_payload_len);
1243 if (ret)
1244 goto out;
1245
1246 total_payload_len += rdma_payload_len;
1247 if (max_t(size_t, payload_len, rdma_payload_len) > RDS_MAX_MSG_SIZE) {
1248 ret = -EMSGSIZE;
1249 goto out;
1250 }
1251
1252 if (payload_len > rds_sk_sndbuf(rs)) {
1253 ret = -EMSGSIZE;
1254 goto out;
1255 }
1256
1257 if (zcopy) {
1258 if (rs->rs_transport->t_type != RDS_TRANS_TCP) {
1259 ret = -EOPNOTSUPP;
1260 goto out;
1261 }
1262 num_sgs = iov_iter_npages(&msg->msg_iter, INT_MAX);
1263 }
1264 /* size of rm including all sgs */
1265 ret = rds_rm_size(msg, num_sgs, &vct);
1266 if (ret < 0)
1267 goto out;
1268
1269 rm = rds_message_alloc(ret, GFP_KERNEL);
1270 if (!rm) {
1271 ret = -ENOMEM;
1272 goto out;
1273 }
1274
1275 /* Attach data to the rm */
1276 if (payload_len) {
1277 rm->data.op_sg = rds_message_alloc_sgs(rm, num_sgs);
1278 if (IS_ERR(rm->data.op_sg)) {
1279 ret = PTR_ERR(rm->data.op_sg);
1280 goto out;
1281 }
1282 ret = rds_message_copy_from_user(rm, &msg->msg_iter, zcopy);
1283 if (ret)
1284 goto out;
1285 }
1286 rm->data.op_active = 1;
1287
1288 rm->m_daddr = daddr;
1289
1290 /* rds_conn_create has a spinlock that runs with IRQ off.
1291 * Caching the conn in the socket helps a lot. */
1292 if (rs->rs_conn && ipv6_addr_equal(&rs->rs_conn->c_faddr, &daddr) &&
1293 rs->rs_tos == rs->rs_conn->c_tos) {
1294 conn = rs->rs_conn;
1295 } else {
1296 conn = rds_conn_create_outgoing(sock_net(sock->sk),
1297 &rs->rs_bound_addr, &daddr,
1298 rs->rs_transport, rs->rs_tos,
1299 sock->sk->sk_allocation,
1300 scope_id);
1301 if (IS_ERR(conn)) {
1302 ret = PTR_ERR(conn);
1303 goto out;
1304 }
1305 rs->rs_conn = conn;
1306 }
1307
1308 if (conn->c_trans->t_mp_capable)
1309 cpath = &conn->c_path[rds_send_mprds_hash(rs, conn, nonblock)];
1310 else
1311 cpath = &conn->c_path[0];
1312
1313 rm->m_conn_path = cpath;
1314
1315 /* Parse any control messages the user may have included. */
1316 ret = rds_cmsg_send(rs, rm, msg, &allocated_mr, &vct);
1317 if (ret) {
1318 /* Trigger connection so that its ready for the next retry */
1319 if (ret == -EAGAIN)
1320 rds_conn_connect_if_down(conn);
1321 goto out;
1322 }
1323
1324 if (rm->rdma.op_active && !conn->c_trans->xmit_rdma) {
1325 printk_ratelimited(KERN_NOTICE "rdma_op %p conn xmit_rdma %p\n",
1326 &rm->rdma, conn->c_trans->xmit_rdma);
1327 ret = -EOPNOTSUPP;
1328 goto out;
1329 }
1330
1331 if (rm->atomic.op_active && !conn->c_trans->xmit_atomic) {
1332 printk_ratelimited(KERN_NOTICE "atomic_op %p conn xmit_atomic %p\n",
1333 &rm->atomic, conn->c_trans->xmit_atomic);
1334 ret = -EOPNOTSUPP;
1335 goto out;
1336 }
1337
1338 if (rds_destroy_pending(conn)) {
1339 ret = -EAGAIN;
1340 goto out;
1341 }
1342
1343 if (rds_conn_path_down(cpath))
1344 rds_check_all_paths(conn);
1345
1346 ret = rds_cong_wait(conn->c_fcong, dport, nonblock, rs);
1347 if (ret) {
1348 rs->rs_seen_congestion = 1;
1349 goto out;
1350 }
1351 while (!rds_send_queue_rm(rs, conn, cpath, rm, rs->rs_bound_port,
1352 dport, &queued)) {
1353 rds_stats_inc(s_send_queue_full);
1354
1355 if (nonblock) {
1356 ret = -EAGAIN;
1357 goto out;
1358 }
1359
1360 timeo = wait_event_interruptible_timeout(*sk_sleep(sk),
1361 rds_send_queue_rm(rs, conn, cpath, rm,
1362 rs->rs_bound_port,
1363 dport,
1364 &queued),
1365 timeo);
1366 rdsdebug("sendmsg woke queued %d timeo %ld\n", queued, timeo);
1367 if (timeo > 0 || timeo == MAX_SCHEDULE_TIMEOUT)
1368 continue;
1369
1370 ret = timeo;
1371 if (ret == 0)
1372 ret = -ETIMEDOUT;
1373 goto out;
1374 }
1375
1376 /*
1377 * By now we've committed to the send. We reuse rds_send_worker()
1378 * to retry sends in the rds thread if the transport asks us to.
1379 */
1380 rds_stats_inc(s_send_queued);
1381
1382 ret = rds_send_xmit(cpath);
1383 if (ret == -ENOMEM || ret == -EAGAIN) {
1384 ret = 0;
1385 rcu_read_lock();
1386 if (rds_destroy_pending(cpath->cp_conn))
1387 ret = -ENETUNREACH;
1388 else
1389 queue_delayed_work(rds_wq, &cpath->cp_send_w, 1);
1390 rcu_read_unlock();
1391 }
1392 if (ret)
1393 goto out;
1394 rds_message_put(rm);
1395
1396 for (ind = 0; ind < vct.indx; ind++)
1397 kfree(vct.vec[ind].iov);
1398 kfree(vct.vec);
1399
1400 return payload_len;
1401
1402out:
1403 for (ind = 0; ind < vct.indx; ind++)
1404 kfree(vct.vec[ind].iov);
1405 kfree(vct.vec);
1406
1407 /* If the user included a RDMA_MAP cmsg, we allocated a MR on the fly.
1408 * If the sendmsg goes through, we keep the MR. If it fails with EAGAIN
1409 * or in any other way, we need to destroy the MR again */
1410 if (allocated_mr)
1411 rds_rdma_unuse(rs, rds_rdma_cookie_key(rm->m_rdma_cookie), 1);
1412
1413 if (rm)
1414 rds_message_put(rm);
1415 return ret;
1416}
1417
1418/*
1419 * send out a probe. Can be shared by rds_send_ping,
1420 * rds_send_pong, rds_send_hb.
1421 * rds_send_hb should use h_flags
1422 * RDS_FLAG_HB_PING|RDS_FLAG_ACK_REQUIRED
1423 * or
1424 * RDS_FLAG_HB_PONG|RDS_FLAG_ACK_REQUIRED
1425 */
1426static int
1427rds_send_probe(struct rds_conn_path *cp, __be16 sport,
1428 __be16 dport, u8 h_flags)
1429{
1430 struct rds_message *rm;
1431 unsigned long flags;
1432 int ret = 0;
1433
1434 rm = rds_message_alloc(0, GFP_ATOMIC);
1435 if (!rm) {
1436 ret = -ENOMEM;
1437 goto out;
1438 }
1439
1440 rm->m_daddr = cp->cp_conn->c_faddr;
1441 rm->data.op_active = 1;
1442
1443 rds_conn_path_connect_if_down(cp);
1444
1445 ret = rds_cong_wait(cp->cp_conn->c_fcong, dport, 1, NULL);
1446 if (ret)
1447 goto out;
1448
1449 spin_lock_irqsave(&cp->cp_lock, flags);
1450 list_add_tail(&rm->m_conn_item, &cp->cp_send_queue);
1451 set_bit(RDS_MSG_ON_CONN, &rm->m_flags);
1452 rds_message_addref(rm);
1453 rm->m_inc.i_conn = cp->cp_conn;
1454 rm->m_inc.i_conn_path = cp;
1455
1456 rds_message_populate_header(&rm->m_inc.i_hdr, sport, dport,
1457 cp->cp_next_tx_seq);
1458 rm->m_inc.i_hdr.h_flags |= h_flags;
1459 cp->cp_next_tx_seq++;
1460
1461 if (RDS_HS_PROBE(be16_to_cpu(sport), be16_to_cpu(dport)) &&
1462 cp->cp_conn->c_trans->t_mp_capable) {
1463 u16 npaths = cpu_to_be16(RDS_MPATH_WORKERS);
1464 u32 my_gen_num = cpu_to_be32(cp->cp_conn->c_my_gen_num);
1465
1466 rds_message_add_extension(&rm->m_inc.i_hdr,
1467 RDS_EXTHDR_NPATHS, &npaths,
1468 sizeof(npaths));
1469 rds_message_add_extension(&rm->m_inc.i_hdr,
1470 RDS_EXTHDR_GEN_NUM,
1471 &my_gen_num,
1472 sizeof(u32));
1473 }
1474 spin_unlock_irqrestore(&cp->cp_lock, flags);
1475
1476 rds_stats_inc(s_send_queued);
1477 rds_stats_inc(s_send_pong);
1478
1479 /* schedule the send work on rds_wq */
1480 rcu_read_lock();
1481 if (!rds_destroy_pending(cp->cp_conn))
1482 queue_delayed_work(rds_wq, &cp->cp_send_w, 1);
1483 rcu_read_unlock();
1484
1485 rds_message_put(rm);
1486 return 0;
1487
1488out:
1489 if (rm)
1490 rds_message_put(rm);
1491 return ret;
1492}
1493
1494int
1495rds_send_pong(struct rds_conn_path *cp, __be16 dport)
1496{
1497 return rds_send_probe(cp, 0, dport, 0);
1498}
1499
1500void
1501rds_send_ping(struct rds_connection *conn, int cp_index)
1502{
1503 unsigned long flags;
1504 struct rds_conn_path *cp = &conn->c_path[cp_index];
1505
1506 spin_lock_irqsave(&cp->cp_lock, flags);
1507 if (conn->c_ping_triggered) {
1508 spin_unlock_irqrestore(&cp->cp_lock, flags);
1509 return;
1510 }
1511 conn->c_ping_triggered = 1;
1512 spin_unlock_irqrestore(&cp->cp_lock, flags);
1513 rds_send_probe(cp, cpu_to_be16(RDS_FLAG_PROBE_PORT), 0, 0);
1514}
1515EXPORT_SYMBOL_GPL(rds_send_ping);
1/*
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>
34#include <linux/moduleparam.h>
35#include <linux/gfp.h>
36#include <net/sock.h>
37#include <linux/in.h>
38#include <linux/list.h>
39#include <linux/ratelimit.h>
40#include <linux/export.h>
41#include <linux/sizes.h>
42
43#include "rds.h"
44
45/* When transmitting messages in rds_send_xmit, we need to emerge from
46 * time to time and briefly release the CPU. Otherwise the softlock watchdog
47 * will kick our shin.
48 * Also, it seems fairer to not let one busy connection stall all the
49 * others.
50 *
51 * send_batch_count is the number of times we'll loop in send_xmit. Setting
52 * it to 0 will restore the old behavior (where we looped until we had
53 * drained the queue).
54 */
55static int send_batch_count = SZ_1K;
56module_param(send_batch_count, int, 0444);
57MODULE_PARM_DESC(send_batch_count, " batch factor when working the send queue");
58
59static void rds_send_remove_from_sock(struct list_head *messages, int status);
60
61/*
62 * Reset the send state. Callers must ensure that this doesn't race with
63 * rds_send_xmit().
64 */
65void rds_send_path_reset(struct rds_conn_path *cp)
66{
67 struct rds_message *rm, *tmp;
68 unsigned long flags;
69
70 if (cp->cp_xmit_rm) {
71 rm = cp->cp_xmit_rm;
72 cp->cp_xmit_rm = NULL;
73 /* Tell the user the RDMA op is no longer mapped by the
74 * transport. This isn't entirely true (it's flushed out
75 * independently) but as the connection is down, there's
76 * no ongoing RDMA to/from that memory */
77 rds_message_unmapped(rm);
78 rds_message_put(rm);
79 }
80
81 cp->cp_xmit_sg = 0;
82 cp->cp_xmit_hdr_off = 0;
83 cp->cp_xmit_data_off = 0;
84 cp->cp_xmit_atomic_sent = 0;
85 cp->cp_xmit_rdma_sent = 0;
86 cp->cp_xmit_data_sent = 0;
87
88 cp->cp_conn->c_map_queued = 0;
89
90 cp->cp_unacked_packets = rds_sysctl_max_unacked_packets;
91 cp->cp_unacked_bytes = rds_sysctl_max_unacked_bytes;
92
93 /* Mark messages as retransmissions, and move them to the send q */
94 spin_lock_irqsave(&cp->cp_lock, flags);
95 list_for_each_entry_safe(rm, tmp, &cp->cp_retrans, m_conn_item) {
96 set_bit(RDS_MSG_ACK_REQUIRED, &rm->m_flags);
97 set_bit(RDS_MSG_RETRANSMITTED, &rm->m_flags);
98 }
99 list_splice_init(&cp->cp_retrans, &cp->cp_send_queue);
100 spin_unlock_irqrestore(&cp->cp_lock, flags);
101}
102EXPORT_SYMBOL_GPL(rds_send_path_reset);
103
104static int acquire_in_xmit(struct rds_conn_path *cp)
105{
106 return test_and_set_bit(RDS_IN_XMIT, &cp->cp_flags) == 0;
107}
108
109static void release_in_xmit(struct rds_conn_path *cp)
110{
111 clear_bit(RDS_IN_XMIT, &cp->cp_flags);
112 smp_mb__after_atomic();
113 /*
114 * We don't use wait_on_bit()/wake_up_bit() because our waking is in a
115 * hot path and finding waiters is very rare. We don't want to walk
116 * the system-wide hashed waitqueue buckets in the fast path only to
117 * almost never find waiters.
118 */
119 if (waitqueue_active(&cp->cp_waitq))
120 wake_up_all(&cp->cp_waitq);
121}
122
123/*
124 * We're making the conscious trade-off here to only send one message
125 * down the connection at a time.
126 * Pro:
127 * - tx queueing is a simple fifo list
128 * - reassembly is optional and easily done by transports per conn
129 * - no per flow rx lookup at all, straight to the socket
130 * - less per-frag memory and wire overhead
131 * Con:
132 * - queued acks can be delayed behind large messages
133 * Depends:
134 * - small message latency is higher behind queued large messages
135 * - large message latency isn't starved by intervening small sends
136 */
137int rds_send_xmit(struct rds_conn_path *cp)
138{
139 struct rds_connection *conn = cp->cp_conn;
140 struct rds_message *rm;
141 unsigned long flags;
142 unsigned int tmp;
143 struct scatterlist *sg;
144 int ret = 0;
145 LIST_HEAD(to_be_dropped);
146 int batch_count;
147 unsigned long send_gen = 0;
148
149restart:
150 batch_count = 0;
151
152 /*
153 * sendmsg calls here after having queued its message on the send
154 * queue. We only have one task feeding the connection at a time. If
155 * another thread is already feeding the queue then we back off. This
156 * avoids blocking the caller and trading per-connection data between
157 * caches per message.
158 */
159 if (!acquire_in_xmit(cp)) {
160 rds_stats_inc(s_send_lock_contention);
161 ret = -ENOMEM;
162 goto out;
163 }
164
165 /*
166 * we record the send generation after doing the xmit acquire.
167 * if someone else manages to jump in and do some work, we'll use
168 * this to avoid a goto restart farther down.
169 *
170 * The acquire_in_xmit() check above ensures that only one
171 * caller can increment c_send_gen at any time.
172 */
173 cp->cp_send_gen++;
174 send_gen = cp->cp_send_gen;
175
176 /*
177 * rds_conn_shutdown() sets the conn state and then tests RDS_IN_XMIT,
178 * we do the opposite to avoid races.
179 */
180 if (!rds_conn_path_up(cp)) {
181 release_in_xmit(cp);
182 ret = 0;
183 goto out;
184 }
185
186 if (conn->c_trans->xmit_path_prepare)
187 conn->c_trans->xmit_path_prepare(cp);
188
189 /*
190 * spin trying to push headers and data down the connection until
191 * the connection doesn't make forward progress.
192 */
193 while (1) {
194
195 rm = cp->cp_xmit_rm;
196
197 /*
198 * If between sending messages, we can send a pending congestion
199 * map update.
200 */
201 if (!rm && test_and_clear_bit(0, &conn->c_map_queued)) {
202 rm = rds_cong_update_alloc(conn);
203 if (IS_ERR(rm)) {
204 ret = PTR_ERR(rm);
205 break;
206 }
207 rm->data.op_active = 1;
208 rm->m_inc.i_conn_path = cp;
209 rm->m_inc.i_conn = cp->cp_conn;
210
211 cp->cp_xmit_rm = rm;
212 }
213
214 /*
215 * If not already working on one, grab the next message.
216 *
217 * cp_xmit_rm holds a ref while we're sending this message down
218 * the connction. We can use this ref while holding the
219 * send_sem.. rds_send_reset() is serialized with it.
220 */
221 if (!rm) {
222 unsigned int len;
223
224 batch_count++;
225
226 /* we want to process as big a batch as we can, but
227 * we also want to avoid softlockups. If we've been
228 * through a lot of messages, lets back off and see
229 * if anyone else jumps in
230 */
231 if (batch_count >= send_batch_count)
232 goto over_batch;
233
234 spin_lock_irqsave(&cp->cp_lock, flags);
235
236 if (!list_empty(&cp->cp_send_queue)) {
237 rm = list_entry(cp->cp_send_queue.next,
238 struct rds_message,
239 m_conn_item);
240 rds_message_addref(rm);
241
242 /*
243 * Move the message from the send queue to the retransmit
244 * list right away.
245 */
246 list_move_tail(&rm->m_conn_item,
247 &cp->cp_retrans);
248 }
249
250 spin_unlock_irqrestore(&cp->cp_lock, flags);
251
252 if (!rm)
253 break;
254
255 /* Unfortunately, the way Infiniband deals with
256 * RDMA to a bad MR key is by moving the entire
257 * queue pair to error state. We cold possibly
258 * recover from that, but right now we drop the
259 * connection.
260 * Therefore, we never retransmit messages with RDMA ops.
261 */
262 if (test_bit(RDS_MSG_FLUSH, &rm->m_flags) ||
263 (rm->rdma.op_active &&
264 test_bit(RDS_MSG_RETRANSMITTED, &rm->m_flags))) {
265 spin_lock_irqsave(&cp->cp_lock, flags);
266 if (test_and_clear_bit(RDS_MSG_ON_CONN, &rm->m_flags))
267 list_move(&rm->m_conn_item, &to_be_dropped);
268 spin_unlock_irqrestore(&cp->cp_lock, flags);
269 continue;
270 }
271
272 /* Require an ACK every once in a while */
273 len = ntohl(rm->m_inc.i_hdr.h_len);
274 if (cp->cp_unacked_packets == 0 ||
275 cp->cp_unacked_bytes < len) {
276 __set_bit(RDS_MSG_ACK_REQUIRED, &rm->m_flags);
277
278 cp->cp_unacked_packets =
279 rds_sysctl_max_unacked_packets;
280 cp->cp_unacked_bytes =
281 rds_sysctl_max_unacked_bytes;
282 rds_stats_inc(s_send_ack_required);
283 } else {
284 cp->cp_unacked_bytes -= len;
285 cp->cp_unacked_packets--;
286 }
287
288 cp->cp_xmit_rm = rm;
289 }
290
291 /* The transport either sends the whole rdma or none of it */
292 if (rm->rdma.op_active && !cp->cp_xmit_rdma_sent) {
293 rm->m_final_op = &rm->rdma;
294 /* The transport owns the mapped memory for now.
295 * You can't unmap it while it's on the send queue
296 */
297 set_bit(RDS_MSG_MAPPED, &rm->m_flags);
298 ret = conn->c_trans->xmit_rdma(conn, &rm->rdma);
299 if (ret) {
300 clear_bit(RDS_MSG_MAPPED, &rm->m_flags);
301 wake_up_interruptible(&rm->m_flush_wait);
302 break;
303 }
304 cp->cp_xmit_rdma_sent = 1;
305
306 }
307
308 if (rm->atomic.op_active && !cp->cp_xmit_atomic_sent) {
309 rm->m_final_op = &rm->atomic;
310 /* The transport owns the mapped memory for now.
311 * You can't unmap it while it's on the send queue
312 */
313 set_bit(RDS_MSG_MAPPED, &rm->m_flags);
314 ret = conn->c_trans->xmit_atomic(conn, &rm->atomic);
315 if (ret) {
316 clear_bit(RDS_MSG_MAPPED, &rm->m_flags);
317 wake_up_interruptible(&rm->m_flush_wait);
318 break;
319 }
320 cp->cp_xmit_atomic_sent = 1;
321
322 }
323
324 /*
325 * A number of cases require an RDS header to be sent
326 * even if there is no data.
327 * We permit 0-byte sends; rds-ping depends on this.
328 * However, if there are exclusively attached silent ops,
329 * we skip the hdr/data send, to enable silent operation.
330 */
331 if (rm->data.op_nents == 0) {
332 int ops_present;
333 int all_ops_are_silent = 1;
334
335 ops_present = (rm->atomic.op_active || rm->rdma.op_active);
336 if (rm->atomic.op_active && !rm->atomic.op_silent)
337 all_ops_are_silent = 0;
338 if (rm->rdma.op_active && !rm->rdma.op_silent)
339 all_ops_are_silent = 0;
340
341 if (ops_present && all_ops_are_silent
342 && !rm->m_rdma_cookie)
343 rm->data.op_active = 0;
344 }
345
346 if (rm->data.op_active && !cp->cp_xmit_data_sent) {
347 rm->m_final_op = &rm->data;
348
349 ret = conn->c_trans->xmit(conn, rm,
350 cp->cp_xmit_hdr_off,
351 cp->cp_xmit_sg,
352 cp->cp_xmit_data_off);
353 if (ret <= 0)
354 break;
355
356 if (cp->cp_xmit_hdr_off < sizeof(struct rds_header)) {
357 tmp = min_t(int, ret,
358 sizeof(struct rds_header) -
359 cp->cp_xmit_hdr_off);
360 cp->cp_xmit_hdr_off += tmp;
361 ret -= tmp;
362 }
363
364 sg = &rm->data.op_sg[cp->cp_xmit_sg];
365 while (ret) {
366 tmp = min_t(int, ret, sg->length -
367 cp->cp_xmit_data_off);
368 cp->cp_xmit_data_off += tmp;
369 ret -= tmp;
370 if (cp->cp_xmit_data_off == sg->length) {
371 cp->cp_xmit_data_off = 0;
372 sg++;
373 cp->cp_xmit_sg++;
374 BUG_ON(ret != 0 && cp->cp_xmit_sg ==
375 rm->data.op_nents);
376 }
377 }
378
379 if (cp->cp_xmit_hdr_off == sizeof(struct rds_header) &&
380 (cp->cp_xmit_sg == rm->data.op_nents))
381 cp->cp_xmit_data_sent = 1;
382 }
383
384 /*
385 * A rm will only take multiple times through this loop
386 * if there is a data op. Thus, if the data is sent (or there was
387 * none), then we're done with the rm.
388 */
389 if (!rm->data.op_active || cp->cp_xmit_data_sent) {
390 cp->cp_xmit_rm = NULL;
391 cp->cp_xmit_sg = 0;
392 cp->cp_xmit_hdr_off = 0;
393 cp->cp_xmit_data_off = 0;
394 cp->cp_xmit_rdma_sent = 0;
395 cp->cp_xmit_atomic_sent = 0;
396 cp->cp_xmit_data_sent = 0;
397
398 rds_message_put(rm);
399 }
400 }
401
402over_batch:
403 if (conn->c_trans->xmit_path_complete)
404 conn->c_trans->xmit_path_complete(cp);
405 release_in_xmit(cp);
406
407 /* Nuke any messages we decided not to retransmit. */
408 if (!list_empty(&to_be_dropped)) {
409 /* irqs on here, so we can put(), unlike above */
410 list_for_each_entry(rm, &to_be_dropped, m_conn_item)
411 rds_message_put(rm);
412 rds_send_remove_from_sock(&to_be_dropped, RDS_RDMA_DROPPED);
413 }
414
415 /*
416 * Other senders can queue a message after we last test the send queue
417 * but before we clear RDS_IN_XMIT. In that case they'd back off and
418 * not try and send their newly queued message. We need to check the
419 * send queue after having cleared RDS_IN_XMIT so that their message
420 * doesn't get stuck on the send queue.
421 *
422 * If the transport cannot continue (i.e ret != 0), then it must
423 * call us when more room is available, such as from the tx
424 * completion handler.
425 *
426 * We have an extra generation check here so that if someone manages
427 * to jump in after our release_in_xmit, we'll see that they have done
428 * some work and we will skip our goto
429 */
430 if (ret == 0) {
431 smp_mb();
432 if ((test_bit(0, &conn->c_map_queued) ||
433 !list_empty(&cp->cp_send_queue)) &&
434 send_gen == cp->cp_send_gen) {
435 rds_stats_inc(s_send_lock_queue_raced);
436 if (batch_count < send_batch_count)
437 goto restart;
438 queue_delayed_work(rds_wq, &cp->cp_send_w, 1);
439 }
440 }
441out:
442 return ret;
443}
444EXPORT_SYMBOL_GPL(rds_send_xmit);
445
446static void rds_send_sndbuf_remove(struct rds_sock *rs, struct rds_message *rm)
447{
448 u32 len = be32_to_cpu(rm->m_inc.i_hdr.h_len);
449
450 assert_spin_locked(&rs->rs_lock);
451
452 BUG_ON(rs->rs_snd_bytes < len);
453 rs->rs_snd_bytes -= len;
454
455 if (rs->rs_snd_bytes == 0)
456 rds_stats_inc(s_send_queue_empty);
457}
458
459static inline int rds_send_is_acked(struct rds_message *rm, u64 ack,
460 is_acked_func is_acked)
461{
462 if (is_acked)
463 return is_acked(rm, ack);
464 return be64_to_cpu(rm->m_inc.i_hdr.h_sequence) <= ack;
465}
466
467/*
468 * This is pretty similar to what happens below in the ACK
469 * handling code - except that we call here as soon as we get
470 * the IB send completion on the RDMA op and the accompanying
471 * message.
472 */
473void rds_rdma_send_complete(struct rds_message *rm, int status)
474{
475 struct rds_sock *rs = NULL;
476 struct rm_rdma_op *ro;
477 struct rds_notifier *notifier;
478 unsigned long flags;
479
480 spin_lock_irqsave(&rm->m_rs_lock, flags);
481
482 ro = &rm->rdma;
483 if (test_bit(RDS_MSG_ON_SOCK, &rm->m_flags) &&
484 ro->op_active && ro->op_notify && ro->op_notifier) {
485 notifier = ro->op_notifier;
486 rs = rm->m_rs;
487 sock_hold(rds_rs_to_sk(rs));
488
489 notifier->n_status = status;
490 spin_lock(&rs->rs_lock);
491 list_add_tail(¬ifier->n_list, &rs->rs_notify_queue);
492 spin_unlock(&rs->rs_lock);
493
494 ro->op_notifier = NULL;
495 }
496
497 spin_unlock_irqrestore(&rm->m_rs_lock, flags);
498
499 if (rs) {
500 rds_wake_sk_sleep(rs);
501 sock_put(rds_rs_to_sk(rs));
502 }
503}
504EXPORT_SYMBOL_GPL(rds_rdma_send_complete);
505
506/*
507 * Just like above, except looks at atomic op
508 */
509void rds_atomic_send_complete(struct rds_message *rm, int status)
510{
511 struct rds_sock *rs = NULL;
512 struct rm_atomic_op *ao;
513 struct rds_notifier *notifier;
514 unsigned long flags;
515
516 spin_lock_irqsave(&rm->m_rs_lock, flags);
517
518 ao = &rm->atomic;
519 if (test_bit(RDS_MSG_ON_SOCK, &rm->m_flags)
520 && ao->op_active && ao->op_notify && ao->op_notifier) {
521 notifier = ao->op_notifier;
522 rs = rm->m_rs;
523 sock_hold(rds_rs_to_sk(rs));
524
525 notifier->n_status = status;
526 spin_lock(&rs->rs_lock);
527 list_add_tail(¬ifier->n_list, &rs->rs_notify_queue);
528 spin_unlock(&rs->rs_lock);
529
530 ao->op_notifier = NULL;
531 }
532
533 spin_unlock_irqrestore(&rm->m_rs_lock, flags);
534
535 if (rs) {
536 rds_wake_sk_sleep(rs);
537 sock_put(rds_rs_to_sk(rs));
538 }
539}
540EXPORT_SYMBOL_GPL(rds_atomic_send_complete);
541
542/*
543 * This is the same as rds_rdma_send_complete except we
544 * don't do any locking - we have all the ingredients (message,
545 * socket, socket lock) and can just move the notifier.
546 */
547static inline void
548__rds_send_complete(struct rds_sock *rs, struct rds_message *rm, int status)
549{
550 struct rm_rdma_op *ro;
551 struct rm_atomic_op *ao;
552
553 ro = &rm->rdma;
554 if (ro->op_active && ro->op_notify && ro->op_notifier) {
555 ro->op_notifier->n_status = status;
556 list_add_tail(&ro->op_notifier->n_list, &rs->rs_notify_queue);
557 ro->op_notifier = NULL;
558 }
559
560 ao = &rm->atomic;
561 if (ao->op_active && ao->op_notify && ao->op_notifier) {
562 ao->op_notifier->n_status = status;
563 list_add_tail(&ao->op_notifier->n_list, &rs->rs_notify_queue);
564 ao->op_notifier = NULL;
565 }
566
567 /* No need to wake the app - caller does this */
568}
569
570/*
571 * This removes messages from the socket's list if they're on it. The list
572 * argument must be private to the caller, we must be able to modify it
573 * without locks. The messages must have a reference held for their
574 * position on the list. This function will drop that reference after
575 * removing the messages from the 'messages' list regardless of if it found
576 * the messages on the socket list or not.
577 */
578static void rds_send_remove_from_sock(struct list_head *messages, int status)
579{
580 unsigned long flags;
581 struct rds_sock *rs = NULL;
582 struct rds_message *rm;
583
584 while (!list_empty(messages)) {
585 int was_on_sock = 0;
586
587 rm = list_entry(messages->next, struct rds_message,
588 m_conn_item);
589 list_del_init(&rm->m_conn_item);
590
591 /*
592 * If we see this flag cleared then we're *sure* that someone
593 * else beat us to removing it from the sock. If we race
594 * with their flag update we'll get the lock and then really
595 * see that the flag has been cleared.
596 *
597 * The message spinlock makes sure nobody clears rm->m_rs
598 * while we're messing with it. It does not prevent the
599 * message from being removed from the socket, though.
600 */
601 spin_lock_irqsave(&rm->m_rs_lock, flags);
602 if (!test_bit(RDS_MSG_ON_SOCK, &rm->m_flags))
603 goto unlock_and_drop;
604
605 if (rs != rm->m_rs) {
606 if (rs) {
607 rds_wake_sk_sleep(rs);
608 sock_put(rds_rs_to_sk(rs));
609 }
610 rs = rm->m_rs;
611 if (rs)
612 sock_hold(rds_rs_to_sk(rs));
613 }
614 if (!rs)
615 goto unlock_and_drop;
616 spin_lock(&rs->rs_lock);
617
618 if (test_and_clear_bit(RDS_MSG_ON_SOCK, &rm->m_flags)) {
619 struct rm_rdma_op *ro = &rm->rdma;
620 struct rds_notifier *notifier;
621
622 list_del_init(&rm->m_sock_item);
623 rds_send_sndbuf_remove(rs, rm);
624
625 if (ro->op_active && ro->op_notifier &&
626 (ro->op_notify || (ro->op_recverr && status))) {
627 notifier = ro->op_notifier;
628 list_add_tail(¬ifier->n_list,
629 &rs->rs_notify_queue);
630 if (!notifier->n_status)
631 notifier->n_status = status;
632 rm->rdma.op_notifier = NULL;
633 }
634 was_on_sock = 1;
635 rm->m_rs = NULL;
636 }
637 spin_unlock(&rs->rs_lock);
638
639unlock_and_drop:
640 spin_unlock_irqrestore(&rm->m_rs_lock, flags);
641 rds_message_put(rm);
642 if (was_on_sock)
643 rds_message_put(rm);
644 }
645
646 if (rs) {
647 rds_wake_sk_sleep(rs);
648 sock_put(rds_rs_to_sk(rs));
649 }
650}
651
652/*
653 * Transports call here when they've determined that the receiver queued
654 * messages up to, and including, the given sequence number. Messages are
655 * moved to the retrans queue when rds_send_xmit picks them off the send
656 * queue. This means that in the TCP case, the message may not have been
657 * assigned the m_ack_seq yet - but that's fine as long as tcp_is_acked
658 * checks the RDS_MSG_HAS_ACK_SEQ bit.
659 */
660void rds_send_path_drop_acked(struct rds_conn_path *cp, u64 ack,
661 is_acked_func is_acked)
662{
663 struct rds_message *rm, *tmp;
664 unsigned long flags;
665 LIST_HEAD(list);
666
667 spin_lock_irqsave(&cp->cp_lock, flags);
668
669 list_for_each_entry_safe(rm, tmp, &cp->cp_retrans, m_conn_item) {
670 if (!rds_send_is_acked(rm, ack, is_acked))
671 break;
672
673 list_move(&rm->m_conn_item, &list);
674 clear_bit(RDS_MSG_ON_CONN, &rm->m_flags);
675 }
676
677 /* order flag updates with spin locks */
678 if (!list_empty(&list))
679 smp_mb__after_atomic();
680
681 spin_unlock_irqrestore(&cp->cp_lock, flags);
682
683 /* now remove the messages from the sock list as needed */
684 rds_send_remove_from_sock(&list, RDS_RDMA_SUCCESS);
685}
686EXPORT_SYMBOL_GPL(rds_send_path_drop_acked);
687
688void rds_send_drop_acked(struct rds_connection *conn, u64 ack,
689 is_acked_func is_acked)
690{
691 WARN_ON(conn->c_trans->t_mp_capable);
692 rds_send_path_drop_acked(&conn->c_path[0], ack, is_acked);
693}
694EXPORT_SYMBOL_GPL(rds_send_drop_acked);
695
696void rds_send_drop_to(struct rds_sock *rs, struct sockaddr_in *dest)
697{
698 struct rds_message *rm, *tmp;
699 struct rds_connection *conn;
700 struct rds_conn_path *cp;
701 unsigned long flags;
702 LIST_HEAD(list);
703
704 /* get all the messages we're dropping under the rs lock */
705 spin_lock_irqsave(&rs->rs_lock, flags);
706
707 list_for_each_entry_safe(rm, tmp, &rs->rs_send_queue, m_sock_item) {
708 if (dest && (dest->sin_addr.s_addr != rm->m_daddr ||
709 dest->sin_port != rm->m_inc.i_hdr.h_dport))
710 continue;
711
712 list_move(&rm->m_sock_item, &list);
713 rds_send_sndbuf_remove(rs, rm);
714 clear_bit(RDS_MSG_ON_SOCK, &rm->m_flags);
715 }
716
717 /* order flag updates with the rs lock */
718 smp_mb__after_atomic();
719
720 spin_unlock_irqrestore(&rs->rs_lock, flags);
721
722 if (list_empty(&list))
723 return;
724
725 /* Remove the messages from the conn */
726 list_for_each_entry(rm, &list, m_sock_item) {
727
728 conn = rm->m_inc.i_conn;
729 if (conn->c_trans->t_mp_capable)
730 cp = rm->m_inc.i_conn_path;
731 else
732 cp = &conn->c_path[0];
733
734 spin_lock_irqsave(&cp->cp_lock, flags);
735 /*
736 * Maybe someone else beat us to removing rm from the conn.
737 * If we race with their flag update we'll get the lock and
738 * then really see that the flag has been cleared.
739 */
740 if (!test_and_clear_bit(RDS_MSG_ON_CONN, &rm->m_flags)) {
741 spin_unlock_irqrestore(&cp->cp_lock, flags);
742 spin_lock_irqsave(&rm->m_rs_lock, flags);
743 rm->m_rs = NULL;
744 spin_unlock_irqrestore(&rm->m_rs_lock, flags);
745 continue;
746 }
747 list_del_init(&rm->m_conn_item);
748 spin_unlock_irqrestore(&cp->cp_lock, flags);
749
750 /*
751 * Couldn't grab m_rs_lock in top loop (lock ordering),
752 * but we can now.
753 */
754 spin_lock_irqsave(&rm->m_rs_lock, flags);
755
756 spin_lock(&rs->rs_lock);
757 __rds_send_complete(rs, rm, RDS_RDMA_CANCELED);
758 spin_unlock(&rs->rs_lock);
759
760 rm->m_rs = NULL;
761 spin_unlock_irqrestore(&rm->m_rs_lock, flags);
762
763 rds_message_put(rm);
764 }
765
766 rds_wake_sk_sleep(rs);
767
768 while (!list_empty(&list)) {
769 rm = list_entry(list.next, struct rds_message, m_sock_item);
770 list_del_init(&rm->m_sock_item);
771 rds_message_wait(rm);
772
773 /* just in case the code above skipped this message
774 * because RDS_MSG_ON_CONN wasn't set, run it again here
775 * taking m_rs_lock is the only thing that keeps us
776 * from racing with ack processing.
777 */
778 spin_lock_irqsave(&rm->m_rs_lock, flags);
779
780 spin_lock(&rs->rs_lock);
781 __rds_send_complete(rs, rm, RDS_RDMA_CANCELED);
782 spin_unlock(&rs->rs_lock);
783
784 rm->m_rs = NULL;
785 spin_unlock_irqrestore(&rm->m_rs_lock, flags);
786
787 rds_message_put(rm);
788 }
789}
790
791/*
792 * we only want this to fire once so we use the callers 'queued'. It's
793 * possible that another thread can race with us and remove the
794 * message from the flow with RDS_CANCEL_SENT_TO.
795 */
796static int rds_send_queue_rm(struct rds_sock *rs, struct rds_connection *conn,
797 struct rds_conn_path *cp,
798 struct rds_message *rm, __be16 sport,
799 __be16 dport, int *queued)
800{
801 unsigned long flags;
802 u32 len;
803
804 if (*queued)
805 goto out;
806
807 len = be32_to_cpu(rm->m_inc.i_hdr.h_len);
808
809 /* this is the only place which holds both the socket's rs_lock
810 * and the connection's c_lock */
811 spin_lock_irqsave(&rs->rs_lock, flags);
812
813 /*
814 * If there is a little space in sndbuf, we don't queue anything,
815 * and userspace gets -EAGAIN. But poll() indicates there's send
816 * room. This can lead to bad behavior (spinning) if snd_bytes isn't
817 * freed up by incoming acks. So we check the *old* value of
818 * rs_snd_bytes here to allow the last msg to exceed the buffer,
819 * and poll() now knows no more data can be sent.
820 */
821 if (rs->rs_snd_bytes < rds_sk_sndbuf(rs)) {
822 rs->rs_snd_bytes += len;
823
824 /* let recv side know we are close to send space exhaustion.
825 * This is probably not the optimal way to do it, as this
826 * means we set the flag on *all* messages as soon as our
827 * throughput hits a certain threshold.
828 */
829 if (rs->rs_snd_bytes >= rds_sk_sndbuf(rs) / 2)
830 __set_bit(RDS_MSG_ACK_REQUIRED, &rm->m_flags);
831
832 list_add_tail(&rm->m_sock_item, &rs->rs_send_queue);
833 set_bit(RDS_MSG_ON_SOCK, &rm->m_flags);
834 rds_message_addref(rm);
835 rm->m_rs = rs;
836
837 /* The code ordering is a little weird, but we're
838 trying to minimize the time we hold c_lock */
839 rds_message_populate_header(&rm->m_inc.i_hdr, sport, dport, 0);
840 rm->m_inc.i_conn = conn;
841 rm->m_inc.i_conn_path = cp;
842 rds_message_addref(rm);
843
844 spin_lock(&cp->cp_lock);
845 rm->m_inc.i_hdr.h_sequence = cpu_to_be64(cp->cp_next_tx_seq++);
846 list_add_tail(&rm->m_conn_item, &cp->cp_send_queue);
847 set_bit(RDS_MSG_ON_CONN, &rm->m_flags);
848 spin_unlock(&cp->cp_lock);
849
850 rdsdebug("queued msg %p len %d, rs %p bytes %d seq %llu\n",
851 rm, len, rs, rs->rs_snd_bytes,
852 (unsigned long long)be64_to_cpu(rm->m_inc.i_hdr.h_sequence));
853
854 *queued = 1;
855 }
856
857 spin_unlock_irqrestore(&rs->rs_lock, flags);
858out:
859 return *queued;
860}
861
862/*
863 * rds_message is getting to be quite complicated, and we'd like to allocate
864 * it all in one go. This figures out how big it needs to be up front.
865 */
866static int rds_rm_size(struct msghdr *msg, int data_len)
867{
868 struct cmsghdr *cmsg;
869 int size = 0;
870 int cmsg_groups = 0;
871 int retval;
872
873 for_each_cmsghdr(cmsg, msg) {
874 if (!CMSG_OK(msg, cmsg))
875 return -EINVAL;
876
877 if (cmsg->cmsg_level != SOL_RDS)
878 continue;
879
880 switch (cmsg->cmsg_type) {
881 case RDS_CMSG_RDMA_ARGS:
882 cmsg_groups |= 1;
883 retval = rds_rdma_extra_size(CMSG_DATA(cmsg));
884 if (retval < 0)
885 return retval;
886 size += retval;
887
888 break;
889
890 case RDS_CMSG_RDMA_DEST:
891 case RDS_CMSG_RDMA_MAP:
892 cmsg_groups |= 2;
893 /* these are valid but do no add any size */
894 break;
895
896 case RDS_CMSG_ATOMIC_CSWP:
897 case RDS_CMSG_ATOMIC_FADD:
898 case RDS_CMSG_MASKED_ATOMIC_CSWP:
899 case RDS_CMSG_MASKED_ATOMIC_FADD:
900 cmsg_groups |= 1;
901 size += sizeof(struct scatterlist);
902 break;
903
904 default:
905 return -EINVAL;
906 }
907
908 }
909
910 size += ceil(data_len, PAGE_SIZE) * sizeof(struct scatterlist);
911
912 /* Ensure (DEST, MAP) are never used with (ARGS, ATOMIC) */
913 if (cmsg_groups == 3)
914 return -EINVAL;
915
916 return size;
917}
918
919static int rds_cmsg_send(struct rds_sock *rs, struct rds_message *rm,
920 struct msghdr *msg, int *allocated_mr)
921{
922 struct cmsghdr *cmsg;
923 int ret = 0;
924
925 for_each_cmsghdr(cmsg, msg) {
926 if (!CMSG_OK(msg, cmsg))
927 return -EINVAL;
928
929 if (cmsg->cmsg_level != SOL_RDS)
930 continue;
931
932 /* As a side effect, RDMA_DEST and RDMA_MAP will set
933 * rm->rdma.m_rdma_cookie and rm->rdma.m_rdma_mr.
934 */
935 switch (cmsg->cmsg_type) {
936 case RDS_CMSG_RDMA_ARGS:
937 ret = rds_cmsg_rdma_args(rs, rm, cmsg);
938 break;
939
940 case RDS_CMSG_RDMA_DEST:
941 ret = rds_cmsg_rdma_dest(rs, rm, cmsg);
942 break;
943
944 case RDS_CMSG_RDMA_MAP:
945 ret = rds_cmsg_rdma_map(rs, rm, cmsg);
946 if (!ret)
947 *allocated_mr = 1;
948 break;
949 case RDS_CMSG_ATOMIC_CSWP:
950 case RDS_CMSG_ATOMIC_FADD:
951 case RDS_CMSG_MASKED_ATOMIC_CSWP:
952 case RDS_CMSG_MASKED_ATOMIC_FADD:
953 ret = rds_cmsg_atomic(rs, rm, cmsg);
954 break;
955
956 default:
957 return -EINVAL;
958 }
959
960 if (ret)
961 break;
962 }
963
964 return ret;
965}
966
967static void rds_send_ping(struct rds_connection *conn);
968
969static int rds_send_mprds_hash(struct rds_sock *rs, struct rds_connection *conn)
970{
971 int hash;
972
973 if (conn->c_npaths == 0)
974 hash = RDS_MPATH_HASH(rs, RDS_MPATH_WORKERS);
975 else
976 hash = RDS_MPATH_HASH(rs, conn->c_npaths);
977 if (conn->c_npaths == 0 && hash != 0) {
978 rds_send_ping(conn);
979
980 if (conn->c_npaths == 0) {
981 wait_event_interruptible(conn->c_hs_waitq,
982 (conn->c_npaths != 0));
983 }
984 if (conn->c_npaths == 1)
985 hash = 0;
986 }
987 return hash;
988}
989
990int rds_sendmsg(struct socket *sock, struct msghdr *msg, size_t payload_len)
991{
992 struct sock *sk = sock->sk;
993 struct rds_sock *rs = rds_sk_to_rs(sk);
994 DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name);
995 __be32 daddr;
996 __be16 dport;
997 struct rds_message *rm = NULL;
998 struct rds_connection *conn;
999 int ret = 0;
1000 int queued = 0, allocated_mr = 0;
1001 int nonblock = msg->msg_flags & MSG_DONTWAIT;
1002 long timeo = sock_sndtimeo(sk, nonblock);
1003 struct rds_conn_path *cpath;
1004
1005 /* Mirror Linux UDP mirror of BSD error message compatibility */
1006 /* XXX: Perhaps MSG_MORE someday */
1007 if (msg->msg_flags & ~(MSG_DONTWAIT | MSG_CMSG_COMPAT)) {
1008 ret = -EOPNOTSUPP;
1009 goto out;
1010 }
1011
1012 if (msg->msg_namelen) {
1013 /* XXX fail non-unicast destination IPs? */
1014 if (msg->msg_namelen < sizeof(*usin) || usin->sin_family != AF_INET) {
1015 ret = -EINVAL;
1016 goto out;
1017 }
1018 daddr = usin->sin_addr.s_addr;
1019 dport = usin->sin_port;
1020 } else {
1021 /* We only care about consistency with ->connect() */
1022 lock_sock(sk);
1023 daddr = rs->rs_conn_addr;
1024 dport = rs->rs_conn_port;
1025 release_sock(sk);
1026 }
1027
1028 lock_sock(sk);
1029 if (daddr == 0 || rs->rs_bound_addr == 0) {
1030 release_sock(sk);
1031 ret = -ENOTCONN; /* XXX not a great errno */
1032 goto out;
1033 }
1034 release_sock(sk);
1035
1036 if (payload_len > rds_sk_sndbuf(rs)) {
1037 ret = -EMSGSIZE;
1038 goto out;
1039 }
1040
1041 /* size of rm including all sgs */
1042 ret = rds_rm_size(msg, payload_len);
1043 if (ret < 0)
1044 goto out;
1045
1046 rm = rds_message_alloc(ret, GFP_KERNEL);
1047 if (!rm) {
1048 ret = -ENOMEM;
1049 goto out;
1050 }
1051
1052 /* Attach data to the rm */
1053 if (payload_len) {
1054 rm->data.op_sg = rds_message_alloc_sgs(rm, ceil(payload_len, PAGE_SIZE));
1055 if (!rm->data.op_sg) {
1056 ret = -ENOMEM;
1057 goto out;
1058 }
1059 ret = rds_message_copy_from_user(rm, &msg->msg_iter);
1060 if (ret)
1061 goto out;
1062 }
1063 rm->data.op_active = 1;
1064
1065 rm->m_daddr = daddr;
1066
1067 /* rds_conn_create has a spinlock that runs with IRQ off.
1068 * Caching the conn in the socket helps a lot. */
1069 if (rs->rs_conn && rs->rs_conn->c_faddr == daddr)
1070 conn = rs->rs_conn;
1071 else {
1072 conn = rds_conn_create_outgoing(sock_net(sock->sk),
1073 rs->rs_bound_addr, daddr,
1074 rs->rs_transport,
1075 sock->sk->sk_allocation);
1076 if (IS_ERR(conn)) {
1077 ret = PTR_ERR(conn);
1078 goto out;
1079 }
1080 rs->rs_conn = conn;
1081 }
1082
1083 /* Parse any control messages the user may have included. */
1084 ret = rds_cmsg_send(rs, rm, msg, &allocated_mr);
1085 if (ret)
1086 goto out;
1087
1088 if (rm->rdma.op_active && !conn->c_trans->xmit_rdma) {
1089 printk_ratelimited(KERN_NOTICE "rdma_op %p conn xmit_rdma %p\n",
1090 &rm->rdma, conn->c_trans->xmit_rdma);
1091 ret = -EOPNOTSUPP;
1092 goto out;
1093 }
1094
1095 if (rm->atomic.op_active && !conn->c_trans->xmit_atomic) {
1096 printk_ratelimited(KERN_NOTICE "atomic_op %p conn xmit_atomic %p\n",
1097 &rm->atomic, conn->c_trans->xmit_atomic);
1098 ret = -EOPNOTSUPP;
1099 goto out;
1100 }
1101
1102 if (conn->c_trans->t_mp_capable)
1103 cpath = &conn->c_path[rds_send_mprds_hash(rs, conn)];
1104 else
1105 cpath = &conn->c_path[0];
1106
1107 rds_conn_path_connect_if_down(cpath);
1108
1109 ret = rds_cong_wait(conn->c_fcong, dport, nonblock, rs);
1110 if (ret) {
1111 rs->rs_seen_congestion = 1;
1112 goto out;
1113 }
1114 while (!rds_send_queue_rm(rs, conn, cpath, rm, rs->rs_bound_port,
1115 dport, &queued)) {
1116 rds_stats_inc(s_send_queue_full);
1117
1118 if (nonblock) {
1119 ret = -EAGAIN;
1120 goto out;
1121 }
1122
1123 timeo = wait_event_interruptible_timeout(*sk_sleep(sk),
1124 rds_send_queue_rm(rs, conn, cpath, rm,
1125 rs->rs_bound_port,
1126 dport,
1127 &queued),
1128 timeo);
1129 rdsdebug("sendmsg woke queued %d timeo %ld\n", queued, timeo);
1130 if (timeo > 0 || timeo == MAX_SCHEDULE_TIMEOUT)
1131 continue;
1132
1133 ret = timeo;
1134 if (ret == 0)
1135 ret = -ETIMEDOUT;
1136 goto out;
1137 }
1138
1139 /*
1140 * By now we've committed to the send. We reuse rds_send_worker()
1141 * to retry sends in the rds thread if the transport asks us to.
1142 */
1143 rds_stats_inc(s_send_queued);
1144
1145 ret = rds_send_xmit(cpath);
1146 if (ret == -ENOMEM || ret == -EAGAIN)
1147 queue_delayed_work(rds_wq, &cpath->cp_send_w, 1);
1148
1149 rds_message_put(rm);
1150 return payload_len;
1151
1152out:
1153 /* If the user included a RDMA_MAP cmsg, we allocated a MR on the fly.
1154 * If the sendmsg goes through, we keep the MR. If it fails with EAGAIN
1155 * or in any other way, we need to destroy the MR again */
1156 if (allocated_mr)
1157 rds_rdma_unuse(rs, rds_rdma_cookie_key(rm->m_rdma_cookie), 1);
1158
1159 if (rm)
1160 rds_message_put(rm);
1161 return ret;
1162}
1163
1164/*
1165 * send out a probe. Can be shared by rds_send_ping,
1166 * rds_send_pong, rds_send_hb.
1167 * rds_send_hb should use h_flags
1168 * RDS_FLAG_HB_PING|RDS_FLAG_ACK_REQUIRED
1169 * or
1170 * RDS_FLAG_HB_PONG|RDS_FLAG_ACK_REQUIRED
1171 */
1172int
1173rds_send_probe(struct rds_conn_path *cp, __be16 sport,
1174 __be16 dport, u8 h_flags)
1175{
1176 struct rds_message *rm;
1177 unsigned long flags;
1178 int ret = 0;
1179
1180 rm = rds_message_alloc(0, GFP_ATOMIC);
1181 if (!rm) {
1182 ret = -ENOMEM;
1183 goto out;
1184 }
1185
1186 rm->m_daddr = cp->cp_conn->c_faddr;
1187 rm->data.op_active = 1;
1188
1189 rds_conn_path_connect_if_down(cp);
1190
1191 ret = rds_cong_wait(cp->cp_conn->c_fcong, dport, 1, NULL);
1192 if (ret)
1193 goto out;
1194
1195 spin_lock_irqsave(&cp->cp_lock, flags);
1196 list_add_tail(&rm->m_conn_item, &cp->cp_send_queue);
1197 set_bit(RDS_MSG_ON_CONN, &rm->m_flags);
1198 rds_message_addref(rm);
1199 rm->m_inc.i_conn = cp->cp_conn;
1200 rm->m_inc.i_conn_path = cp;
1201
1202 rds_message_populate_header(&rm->m_inc.i_hdr, sport, dport,
1203 cp->cp_next_tx_seq);
1204 rm->m_inc.i_hdr.h_flags |= h_flags;
1205 cp->cp_next_tx_seq++;
1206
1207 if (RDS_HS_PROBE(sport, dport) && cp->cp_conn->c_trans->t_mp_capable) {
1208 u16 npaths = RDS_MPATH_WORKERS;
1209
1210 rds_message_add_extension(&rm->m_inc.i_hdr,
1211 RDS_EXTHDR_NPATHS, &npaths,
1212 sizeof(npaths));
1213 rds_message_add_extension(&rm->m_inc.i_hdr,
1214 RDS_EXTHDR_GEN_NUM,
1215 &cp->cp_conn->c_my_gen_num,
1216 sizeof(u32));
1217 }
1218 spin_unlock_irqrestore(&cp->cp_lock, flags);
1219
1220 rds_stats_inc(s_send_queued);
1221 rds_stats_inc(s_send_pong);
1222
1223 /* schedule the send work on rds_wq */
1224 queue_delayed_work(rds_wq, &cp->cp_send_w, 1);
1225
1226 rds_message_put(rm);
1227 return 0;
1228
1229out:
1230 if (rm)
1231 rds_message_put(rm);
1232 return ret;
1233}
1234
1235int
1236rds_send_pong(struct rds_conn_path *cp, __be16 dport)
1237{
1238 return rds_send_probe(cp, 0, dport, 0);
1239}
1240
1241void
1242rds_send_ping(struct rds_connection *conn)
1243{
1244 unsigned long flags;
1245 struct rds_conn_path *cp = &conn->c_path[0];
1246
1247 spin_lock_irqsave(&cp->cp_lock, flags);
1248 if (conn->c_ping_triggered) {
1249 spin_unlock_irqrestore(&cp->cp_lock, flags);
1250 return;
1251 }
1252 conn->c_ping_triggered = 1;
1253 spin_unlock_irqrestore(&cp->cp_lock, flags);
1254 rds_send_probe(&conn->c_path[0], RDS_FLAG_PROBE_PORT, 0, 0);
1255}