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TOMOYO Linux Cross Reference
Linux/net/rds/send.c

Version: ~ [ linux-6.1-rc7 ] ~ [ linux-6.0.10 ] ~ [ linux-5.19.17 ] ~ [ linux-5.18.19 ] ~ [ linux-5.17.15 ] ~ [ linux-5.16.20 ] ~ [ linux-5.15.80 ] ~ [ linux-5.14.21 ] ~ [ linux-5.13.19 ] ~ [ linux-5.12.19 ] ~ [ linux-5.11.22 ] ~ [ linux-5.10.156 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.225 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.267 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.300 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.334 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.302 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.9 ] ~ [ policy-sample ] ~
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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  */
 55 static int send_batch_count = SZ_1K;
 56 module_param(send_batch_count, int, 0444);
 57 MODULE_PARM_DESC(send_batch_count, " batch factor when working the send queue");
 58 
 59 static 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  */
 65 void 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 }
102 EXPORT_SYMBOL_GPL(rds_send_path_reset);
103 
104 static 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 
109 static 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  */
137 int 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 
150 restart:
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 
420 over_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         }
468 out:
469         return ret;
470 }
471 EXPORT_SYMBOL_GPL(rds_send_xmit);
472 
473 static 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 
486 static 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  */
500 void 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(&notifier->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 }
531 EXPORT_SYMBOL_GPL(rds_rdma_send_complete);
532 
533 /*
534  * Just like above, except looks at atomic op
535  */
536 void 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(&notifier->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 }
567 EXPORT_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  */
574 static 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  */
605 static 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(&notifier->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 
665 unlock_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  */
686 void 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 }
712 EXPORT_SYMBOL_GPL(rds_send_path_drop_acked);
713 
714 void 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 }
720 EXPORT_SYMBOL_GPL(rds_send_drop_acked);
721 
722 void 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  */
818 static 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);
881 out:
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  */
889 static 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 
971 static 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 
984 static 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 
1045 static 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 
1078 static 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 
1101 int 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 
1402 out:
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  */
1426 static int
1427 rds_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 
1488 out:
1489         if (rm)
1490                 rds_message_put(rm);
1491         return ret;
1492 }
1493 
1494 int
1495 rds_send_pong(struct rds_conn_path *cp, __be16 dport)
1496 {
1497         return rds_send_probe(cp, 0, dport, 0);
1498 }
1499 
1500 void
1501 rds_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 }
1515 EXPORT_SYMBOL_GPL(rds_send_ping);
1516 

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