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 */ 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; 148 149 restart: 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 if (rds_destroy_pending(cp->cp_conn)) { 166 release_in_xmit(cp); 167 ret = -ENETUNREACH; /* dont requeue send work */ 168 goto out; 169 } 170 171 /* 172 * we record the send generation after doing the xmit acquire. 173 * if someone else manages to jump in and do some work, we'll use 174 * this to avoid a goto restart farther down. 175 * 176 * The acquire_in_xmit() check above ensures that only one 177 * caller can increment c_send_gen at any time. 178 */ 179 send_gen = READ_ONCE(cp->cp_send_gen) + 1; 180 WRITE_ONCE(cp->cp_send_gen, send_gen); 181 182 /* 183 * rds_conn_shutdown() sets the conn state and then tests RDS_IN_XMIT, 184 * we do the opposite to avoid races. 185 */ 186 if (!rds_conn_path_up(cp)) { 187 release_in_xmit(cp); 188 ret = 0; 189 goto out; 190 } 191 192 if (conn->c_trans->xmit_path_prepare) 193 conn->c_trans->xmit_path_prepare(cp); 194 195 /* 196 * spin trying to push headers and data down the connection until 197 * the connection doesn't make forward progress. 198 */ 199 while (1) { 200 201 rm = cp->cp_xmit_rm; 202 203 /* 204 * If between sending messages, we can send a pending congestion 205 * map update. 206 */ 207 if (!rm && test_and_clear_bit(0, &conn->c_map_queued)) { 208 rm = rds_cong_update_alloc(conn); 209 if (IS_ERR(rm)) { 210 ret = PTR_ERR(rm); 211 break; 212 } 213 rm->data.op_active = 1; 214 rm->m_inc.i_conn_path = cp; 215 rm->m_inc.i_conn = cp->cp_conn; 216 217 cp->cp_xmit_rm = rm; 218 } 219 220 /* 221 * If not already working on one, grab the next message. 222 * 223 * cp_xmit_rm holds a ref while we're sending this message down 224 * the connction. We can use this ref while holding the 225 * send_sem.. rds_send_reset() is serialized with it. 226 */ 227 if (!rm) { 228 unsigned int len; 229 230 batch_count++; 231 232 /* we want to process as big a batch as we can, but 233 * we also want to avoid softlockups. If we've been 234 * through a lot of messages, lets back off and see 235 * if anyone else jumps in 236 */ 237 if (batch_count >= send_batch_count) 238 goto over_batch; 239 240 spin_lock_irqsave(&cp->cp_lock, flags); 241 242 if (!list_empty(&cp->cp_send_queue)) { 243 rm = list_entry(cp->cp_send_queue.next, 244 struct rds_message, 245 m_conn_item); 246 rds_message_addref(rm); 247 248 /* 249 * Move the message from the send queue to the retransmit 250 * list right away. 251 */ 252 list_move_tail(&rm->m_conn_item, 253 &cp->cp_retrans); 254 } 255 256 spin_unlock_irqrestore(&cp->cp_lock, flags); 257 258 if (!rm) 259 break; 260 261 /* Unfortunately, the way Infiniband deals with 262 * RDMA to a bad MR key is by moving the entire 263 * queue pair to error state. We cold possibly 264 * recover from that, but right now we drop the 265 * connection. 266 * Therefore, we never retransmit messages with RDMA ops. 267 */ 268 if (test_bit(RDS_MSG_FLUSH, &rm->m_flags) || 269 (rm->rdma.op_active && 270 test_bit(RDS_MSG_RETRANSMITTED, &rm->m_flags))) { 271 spin_lock_irqsave(&cp->cp_lock, flags); 272 if (test_and_clear_bit(RDS_MSG_ON_CONN, &rm->m_flags)) 273 list_move(&rm->m_conn_item, &to_be_dropped); 274 spin_unlock_irqrestore(&cp->cp_lock, flags); 275 continue; 276 } 277 278 /* Require an ACK every once in a while */ 279 len = ntohl(rm->m_inc.i_hdr.h_len); 280 if (cp->cp_unacked_packets == 0 || 281 cp->cp_unacked_bytes < len) { 282 set_bit(RDS_MSG_ACK_REQUIRED, &rm->m_flags); 283 284 cp->cp_unacked_packets = 285 rds_sysctl_max_unacked_packets; 286 cp->cp_unacked_bytes = 287 rds_sysctl_max_unacked_bytes; 288 rds_stats_inc(s_send_ack_required); 289 } else { 290 cp->cp_unacked_bytes -= len; 291 cp->cp_unacked_packets--; 292 } 293 294 cp->cp_xmit_rm = rm; 295 } 296 297 /* The transport either sends the whole rdma or none of it */ 298 if (rm->rdma.op_active && !cp->cp_xmit_rdma_sent) { 299 rm->m_final_op = &rm->rdma; 300 /* The transport owns the mapped memory for now. 301 * You can't unmap it while it's on the send queue 302 */ 303 set_bit(RDS_MSG_MAPPED, &rm->m_flags); 304 ret = conn->c_trans->xmit_rdma(conn, &rm->rdma); 305 if (ret) { 306 clear_bit(RDS_MSG_MAPPED, &rm->m_flags); 307 wake_up_interruptible(&rm->m_flush_wait); 308 break; 309 } 310 cp->cp_xmit_rdma_sent = 1; 311 312 } 313 314 if (rm->atomic.op_active && !cp->cp_xmit_atomic_sent) { 315 rm->m_final_op = &rm->atomic; 316 /* The transport owns the mapped memory for now. 317 * You can't unmap it while it's on the send queue 318 */ 319 set_bit(RDS_MSG_MAPPED, &rm->m_flags); 320 ret = conn->c_trans->xmit_atomic(conn, &rm->atomic); 321 if (ret) { 322 clear_bit(RDS_MSG_MAPPED, &rm->m_flags); 323 wake_up_interruptible(&rm->m_flush_wait); 324 break; 325 } 326 cp->cp_xmit_atomic_sent = 1; 327 328 } 329 330 /* 331 * A number of cases require an RDS header to be sent 332 * even if there is no data. 333 * We permit 0-byte sends; rds-ping depends on this. 334 * However, if there are exclusively attached silent ops, 335 * we skip the hdr/data send, to enable silent operation. 336 */ 337 if (rm->data.op_nents == 0) { 338 int ops_present; 339 int all_ops_are_silent = 1; 340 341 ops_present = (rm->atomic.op_active || rm->rdma.op_active); 342 if (rm->atomic.op_active && !rm->atomic.op_silent) 343 all_ops_are_silent = 0; 344 if (rm->rdma.op_active && !rm->rdma.op_silent) 345 all_ops_are_silent = 0; 346 347 if (ops_present && all_ops_are_silent 348 && !rm->m_rdma_cookie) 349 rm->data.op_active = 0; 350 } 351 352 if (rm->data.op_active && !cp->cp_xmit_data_sent) { 353 rm->m_final_op = &rm->data; 354 355 ret = conn->c_trans->xmit(conn, rm, 356 cp->cp_xmit_hdr_off, 357 cp->cp_xmit_sg, 358 cp->cp_xmit_data_off); 359 if (ret <= 0) 360 break; 361 362 if (cp->cp_xmit_hdr_off < sizeof(struct rds_header)) { 363 tmp = min_t(int, ret, 364 sizeof(struct rds_header) - 365 cp->cp_xmit_hdr_off); 366 cp->cp_xmit_hdr_off += tmp; 367 ret -= tmp; 368 } 369 370 sg = &rm->data.op_sg[cp->cp_xmit_sg]; 371 while (ret) { 372 tmp = min_t(int, ret, sg->length - 373 cp->cp_xmit_data_off); 374 cp->cp_xmit_data_off += tmp; 375 ret -= tmp; 376 if (cp->cp_xmit_data_off == sg->length) { 377 cp->cp_xmit_data_off = 0; 378 sg++; 379 cp->cp_xmit_sg++; 380 BUG_ON(ret != 0 && cp->cp_xmit_sg == 381 rm->data.op_nents); 382 } 383 } 384 385 if (cp->cp_xmit_hdr_off == sizeof(struct rds_header) && 386 (cp->cp_xmit_sg == rm->data.op_nents)) 387 cp->cp_xmit_data_sent = 1; 388 } 389 390 /* 391 * A rm will only take multiple times through this loop 392 * if there is a data op. Thus, if the data is sent (or there was 393 * none), then we're done with the rm. 394 */ 395 if (!rm->data.op_active || cp->cp_xmit_data_sent) { 396 cp->cp_xmit_rm = NULL; 397 cp->cp_xmit_sg = 0; 398 cp->cp_xmit_hdr_off = 0; 399 cp->cp_xmit_data_off = 0; 400 cp->cp_xmit_rdma_sent = 0; 401 cp->cp_xmit_atomic_sent = 0; 402 cp->cp_xmit_data_sent = 0; 403 404 rds_message_put(rm); 405 } 406 } 407 408 over_batch: 409 if (conn->c_trans->xmit_path_complete) 410 conn->c_trans->xmit_path_complete(cp); 411 release_in_xmit(cp); 412 413 /* Nuke any messages we decided not to retransmit. */ 414 if (!list_empty(&to_be_dropped)) { 415 /* irqs on here, so we can put(), unlike above */ 416 list_for_each_entry(rm, &to_be_dropped, m_conn_item) 417 rds_message_put(rm); 418 rds_send_remove_from_sock(&to_be_dropped, RDS_RDMA_DROPPED); 419 } 420 421 /* 422 * Other senders can queue a message after we last test the send queue 423 * but before we clear RDS_IN_XMIT. In that case they'd back off and 424 * not try and send their newly queued message. We need to check the 425 * send queue after having cleared RDS_IN_XMIT so that their message 426 * doesn't get stuck on the send queue. 427 * 428 * If the transport cannot continue (i.e ret != 0), then it must 429 * call us when more room is available, such as from the tx 430 * completion handler. 431 * 432 * We have an extra generation check here so that if someone manages 433 * to jump in after our release_in_xmit, we'll see that they have done 434 * some work and we will skip our goto 435 */ 436 if (ret == 0) { 437 bool raced; 438 439 smp_mb(); 440 raced = send_gen != READ_ONCE(cp->cp_send_gen); 441 442 if ((test_bit(0, &conn->c_map_queued) || 443 !list_empty(&cp->cp_send_queue)) && !raced) { 444 if (batch_count < send_batch_count) 445 goto restart; 446 rcu_read_lock(); 447 if (rds_destroy_pending(cp->cp_conn)) 448 ret = -ENETUNREACH; 449 else 450 queue_delayed_work(rds_wq, &cp->cp_send_w, 1); 451 rcu_read_unlock(); 452 } else if (raced) { 453 rds_stats_inc(s_send_lock_queue_raced); 454 } 455 } 456 out: 457 return ret; 458 } 459 EXPORT_SYMBOL_GPL(rds_send_xmit); 460 461 static void rds_send_sndbuf_remove(struct rds_sock *rs, struct rds_message *rm) 462 { 463 u32 len = be32_to_cpu(rm->m_inc.i_hdr.h_len); 464 465 assert_spin_locked(&rs->rs_lock); 466 467 BUG_ON(rs->rs_snd_bytes < len); 468 rs->rs_snd_bytes -= len; 469 470 if (rs->rs_snd_bytes == 0) 471 rds_stats_inc(s_send_queue_empty); 472 } 473 474 static inline int rds_send_is_acked(struct rds_message *rm, u64 ack, 475 is_acked_func is_acked) 476 { 477 if (is_acked) 478 return is_acked(rm, ack); 479 return be64_to_cpu(rm->m_inc.i_hdr.h_sequence) <= ack; 480 } 481 482 /* 483 * This is pretty similar to what happens below in the ACK 484 * handling code - except that we call here as soon as we get 485 * the IB send completion on the RDMA op and the accompanying 486 * message. 487 */ 488 void rds_rdma_send_complete(struct rds_message *rm, int status) 489 { 490 struct rds_sock *rs = NULL; 491 struct rm_rdma_op *ro; 492 struct rds_notifier *notifier; 493 unsigned long flags; 494 unsigned int notify = 0; 495 496 spin_lock_irqsave(&rm->m_rs_lock, flags); 497 498 notify = rm->rdma.op_notify | rm->data.op_notify; 499 ro = &rm->rdma; 500 if (test_bit(RDS_MSG_ON_SOCK, &rm->m_flags) && 501 ro->op_active && notify && ro->op_notifier) { 502 notifier = ro->op_notifier; 503 rs = rm->m_rs; 504 sock_hold(rds_rs_to_sk(rs)); 505 506 notifier->n_status = status; 507 spin_lock(&rs->rs_lock); 508 list_add_tail(¬ifier->n_list, &rs->rs_notify_queue); 509 spin_unlock(&rs->rs_lock); 510 511 ro->op_notifier = NULL; 512 } 513 514 spin_unlock_irqrestore(&rm->m_rs_lock, flags); 515 516 if (rs) { 517 rds_wake_sk_sleep(rs); 518 sock_put(rds_rs_to_sk(rs)); 519 } 520 } 521 EXPORT_SYMBOL_GPL(rds_rdma_send_complete); 522 523 /* 524 * Just like above, except looks at atomic op 525 */ 526 void rds_atomic_send_complete(struct rds_message *rm, int status) 527 { 528 struct rds_sock *rs = NULL; 529 struct rm_atomic_op *ao; 530 struct rds_notifier *notifier; 531 unsigned long flags; 532 533 spin_lock_irqsave(&rm->m_rs_lock, flags); 534 535 ao = &rm->atomic; 536 if (test_bit(RDS_MSG_ON_SOCK, &rm->m_flags) 537 && ao->op_active && ao->op_notify && ao->op_notifier) { 538 notifier = ao->op_notifier; 539 rs = rm->m_rs; 540 sock_hold(rds_rs_to_sk(rs)); 541 542 notifier->n_status = status; 543 spin_lock(&rs->rs_lock); 544 list_add_tail(¬ifier->n_list, &rs->rs_notify_queue); 545 spin_unlock(&rs->rs_lock); 546 547 ao->op_notifier = NULL; 548 } 549 550 spin_unlock_irqrestore(&rm->m_rs_lock, flags); 551 552 if (rs) { 553 rds_wake_sk_sleep(rs); 554 sock_put(rds_rs_to_sk(rs)); 555 } 556 } 557 EXPORT_SYMBOL_GPL(rds_atomic_send_complete); 558 559 /* 560 * This is the same as rds_rdma_send_complete except we 561 * don't do any locking - we have all the ingredients (message, 562 * socket, socket lock) and can just move the notifier. 563 */ 564 static inline void 565 __rds_send_complete(struct rds_sock *rs, struct rds_message *rm, int status) 566 { 567 struct rm_rdma_op *ro; 568 struct rm_atomic_op *ao; 569 570 ro = &rm->rdma; 571 if (ro->op_active && ro->op_notify && ro->op_notifier) { 572 ro->op_notifier->n_status = status; 573 list_add_tail(&ro->op_notifier->n_list, &rs->rs_notify_queue); 574 ro->op_notifier = NULL; 575 } 576 577 ao = &rm->atomic; 578 if (ao->op_active && ao->op_notify && ao->op_notifier) { 579 ao->op_notifier->n_status = status; 580 list_add_tail(&ao->op_notifier->n_list, &rs->rs_notify_queue); 581 ao->op_notifier = NULL; 582 } 583 584 /* No need to wake the app - caller does this */ 585 } 586 587 /* 588 * This removes messages from the socket's list if they're on it. The list 589 * argument must be private to the caller, we must be able to modify it 590 * without locks. The messages must have a reference held for their 591 * position on the list. This function will drop that reference after 592 * removing the messages from the 'messages' list regardless of if it found 593 * the messages on the socket list or not. 594 */ 595 static void rds_send_remove_from_sock(struct list_head *messages, int status) 596 { 597 unsigned long flags; 598 struct rds_sock *rs = NULL; 599 struct rds_message *rm; 600 601 while (!list_empty(messages)) { 602 int was_on_sock = 0; 603 604 rm = list_entry(messages->next, struct rds_message, 605 m_conn_item); 606 list_del_init(&rm->m_conn_item); 607 608 /* 609 * If we see this flag cleared then we're *sure* that someone 610 * else beat us to removing it from the sock. If we race 611 * with their flag update we'll get the lock and then really 612 * see that the flag has been cleared. 613 * 614 * The message spinlock makes sure nobody clears rm->m_rs 615 * while we're messing with it. It does not prevent the 616 * message from being removed from the socket, though. 617 */ 618 spin_lock_irqsave(&rm->m_rs_lock, flags); 619 if (!test_bit(RDS_MSG_ON_SOCK, &rm->m_flags)) 620 goto unlock_and_drop; 621 622 if (rs != rm->m_rs) { 623 if (rs) { 624 rds_wake_sk_sleep(rs); 625 sock_put(rds_rs_to_sk(rs)); 626 } 627 rs = rm->m_rs; 628 if (rs) 629 sock_hold(rds_rs_to_sk(rs)); 630 } 631 if (!rs) 632 goto unlock_and_drop; 633 spin_lock(&rs->rs_lock); 634 635 if (test_and_clear_bit(RDS_MSG_ON_SOCK, &rm->m_flags)) { 636 struct rm_rdma_op *ro = &rm->rdma; 637 struct rds_notifier *notifier; 638 639 list_del_init(&rm->m_sock_item); 640 rds_send_sndbuf_remove(rs, rm); 641 642 if (ro->op_active && ro->op_notifier && 643 (ro->op_notify || (ro->op_recverr && status))) { 644 notifier = ro->op_notifier; 645 list_add_tail(¬ifier->n_list, 646 &rs->rs_notify_queue); 647 if (!notifier->n_status) 648 notifier->n_status = status; 649 rm->rdma.op_notifier = NULL; 650 } 651 was_on_sock = 1; 652 rm->m_rs = NULL; 653 } 654 spin_unlock(&rs->rs_lock); 655 656 unlock_and_drop: 657 spin_unlock_irqrestore(&rm->m_rs_lock, flags); 658 rds_message_put(rm); 659 if (was_on_sock) 660 rds_message_put(rm); 661 } 662 663 if (rs) { 664 rds_wake_sk_sleep(rs); 665 sock_put(rds_rs_to_sk(rs)); 666 } 667 } 668 669 /* 670 * Transports call here when they've determined that the receiver queued 671 * messages up to, and including, the given sequence number. Messages are 672 * moved to the retrans queue when rds_send_xmit picks them off the send 673 * queue. This means that in the TCP case, the message may not have been 674 * assigned the m_ack_seq yet - but that's fine as long as tcp_is_acked 675 * checks the RDS_MSG_HAS_ACK_SEQ bit. 676 */ 677 void rds_send_path_drop_acked(struct rds_conn_path *cp, u64 ack, 678 is_acked_func is_acked) 679 { 680 struct rds_message *rm, *tmp; 681 unsigned long flags; 682 LIST_HEAD(list); 683 684 spin_lock_irqsave(&cp->cp_lock, flags); 685 686 list_for_each_entry_safe(rm, tmp, &cp->cp_retrans, m_conn_item) { 687 if (!rds_send_is_acked(rm, ack, is_acked)) 688 break; 689 690 list_move(&rm->m_conn_item, &list); 691 clear_bit(RDS_MSG_ON_CONN, &rm->m_flags); 692 } 693 694 /* order flag updates with spin locks */ 695 if (!list_empty(&list)) 696 smp_mb__after_atomic(); 697 698 spin_unlock_irqrestore(&cp->cp_lock, flags); 699 700 /* now remove the messages from the sock list as needed */ 701 rds_send_remove_from_sock(&list, RDS_RDMA_SUCCESS); 702 } 703 EXPORT_SYMBOL_GPL(rds_send_path_drop_acked); 704 705 void rds_send_drop_acked(struct rds_connection *conn, u64 ack, 706 is_acked_func is_acked) 707 { 708 WARN_ON(conn->c_trans->t_mp_capable); 709 rds_send_path_drop_acked(&conn->c_path[0], ack, is_acked); 710 } 711 EXPORT_SYMBOL_GPL(rds_send_drop_acked); 712 713 void rds_send_drop_to(struct rds_sock *rs, struct sockaddr_in *dest) 714 { 715 struct rds_message *rm, *tmp; 716 struct rds_connection *conn; 717 struct rds_conn_path *cp; 718 unsigned long flags; 719 LIST_HEAD(list); 720 721 /* get all the messages we're dropping under the rs lock */ 722 spin_lock_irqsave(&rs->rs_lock, flags); 723 724 list_for_each_entry_safe(rm, tmp, &rs->rs_send_queue, m_sock_item) { 725 if (dest && (dest->sin_addr.s_addr != rm->m_daddr || 726 dest->sin_port != rm->m_inc.i_hdr.h_dport)) 727 continue; 728 729 list_move(&rm->m_sock_item, &list); 730 rds_send_sndbuf_remove(rs, rm); 731 clear_bit(RDS_MSG_ON_SOCK, &rm->m_flags); 732 } 733 734 /* order flag updates with the rs lock */ 735 smp_mb__after_atomic(); 736 737 spin_unlock_irqrestore(&rs->rs_lock, flags); 738 739 if (list_empty(&list)) 740 return; 741 742 /* Remove the messages from the conn */ 743 list_for_each_entry(rm, &list, m_sock_item) { 744 745 conn = rm->m_inc.i_conn; 746 if (conn->c_trans->t_mp_capable) 747 cp = rm->m_inc.i_conn_path; 748 else 749 cp = &conn->c_path[0]; 750 751 spin_lock_irqsave(&cp->cp_lock, flags); 752 /* 753 * Maybe someone else beat us to removing rm from the conn. 754 * If we race with their flag update we'll get the lock and 755 * then really see that the flag has been cleared. 756 */ 757 if (!test_and_clear_bit(RDS_MSG_ON_CONN, &rm->m_flags)) { 758 spin_unlock_irqrestore(&cp->cp_lock, flags); 759 spin_lock_irqsave(&rm->m_rs_lock, flags); 760 rm->m_rs = NULL; 761 spin_unlock_irqrestore(&rm->m_rs_lock, flags); 762 continue; 763 } 764 list_del_init(&rm->m_conn_item); 765 spin_unlock_irqrestore(&cp->cp_lock, flags); 766 767 /* 768 * Couldn't grab m_rs_lock in top loop (lock ordering), 769 * but we can now. 770 */ 771 spin_lock_irqsave(&rm->m_rs_lock, flags); 772 773 spin_lock(&rs->rs_lock); 774 __rds_send_complete(rs, rm, RDS_RDMA_CANCELED); 775 spin_unlock(&rs->rs_lock); 776 777 rm->m_rs = NULL; 778 spin_unlock_irqrestore(&rm->m_rs_lock, flags); 779 780 rds_message_put(rm); 781 } 782 783 rds_wake_sk_sleep(rs); 784 785 while (!list_empty(&list)) { 786 rm = list_entry(list.next, struct rds_message, m_sock_item); 787 list_del_init(&rm->m_sock_item); 788 rds_message_wait(rm); 789 790 /* just in case the code above skipped this message 791 * because RDS_MSG_ON_CONN wasn't set, run it again here 792 * taking m_rs_lock is the only thing that keeps us 793 * from racing with ack processing. 794 */ 795 spin_lock_irqsave(&rm->m_rs_lock, flags); 796 797 spin_lock(&rs->rs_lock); 798 __rds_send_complete(rs, rm, RDS_RDMA_CANCELED); 799 spin_unlock(&rs->rs_lock); 800 801 rm->m_rs = NULL; 802 spin_unlock_irqrestore(&rm->m_rs_lock, flags); 803 804 rds_message_put(rm); 805 } 806 } 807 808 /* 809 * we only want this to fire once so we use the callers 'queued'. It's 810 * possible that another thread can race with us and remove the 811 * message from the flow with RDS_CANCEL_SENT_TO. 812 */ 813 static int rds_send_queue_rm(struct rds_sock *rs, struct rds_connection *conn, 814 struct rds_conn_path *cp, 815 struct rds_message *rm, __be16 sport, 816 __be16 dport, int *queued) 817 { 818 unsigned long flags; 819 u32 len; 820 821 if (*queued) 822 goto out; 823 824 len = be32_to_cpu(rm->m_inc.i_hdr.h_len); 825 826 /* this is the only place which holds both the socket's rs_lock 827 * and the connection's c_lock */ 828 spin_lock_irqsave(&rs->rs_lock, flags); 829 830 /* 831 * If there is a little space in sndbuf, we don't queue anything, 832 * and userspace gets -EAGAIN. But poll() indicates there's send 833 * room. This can lead to bad behavior (spinning) if snd_bytes isn't 834 * freed up by incoming acks. So we check the *old* value of 835 * rs_snd_bytes here to allow the last msg to exceed the buffer, 836 * and poll() now knows no more data can be sent. 837 */ 838 if (rs->rs_snd_bytes < rds_sk_sndbuf(rs)) { 839 rs->rs_snd_bytes += len; 840 841 /* let recv side know we are close to send space exhaustion. 842 * This is probably not the optimal way to do it, as this 843 * means we set the flag on *all* messages as soon as our 844 * throughput hits a certain threshold. 845 */ 846 if (rs->rs_snd_bytes >= rds_sk_sndbuf(rs) / 2) 847 set_bit(RDS_MSG_ACK_REQUIRED, &rm->m_flags); 848 849 list_add_tail(&rm->m_sock_item, &rs->rs_send_queue); 850 set_bit(RDS_MSG_ON_SOCK, &rm->m_flags); 851 rds_message_addref(rm); 852 rm->m_rs = rs; 853 854 /* The code ordering is a little weird, but we're 855 trying to minimize the time we hold c_lock */ 856 rds_message_populate_header(&rm->m_inc.i_hdr, sport, dport, 0); 857 rm->m_inc.i_conn = conn; 858 rm->m_inc.i_conn_path = cp; 859 rds_message_addref(rm); 860 861 spin_lock(&cp->cp_lock); 862 rm->m_inc.i_hdr.h_sequence = cpu_to_be64(cp->cp_next_tx_seq++); 863 list_add_tail(&rm->m_conn_item, &cp->cp_send_queue); 864 set_bit(RDS_MSG_ON_CONN, &rm->m_flags); 865 spin_unlock(&cp->cp_lock); 866 867 rdsdebug("queued msg %p len %d, rs %p bytes %d seq %llu\n", 868 rm, len, rs, rs->rs_snd_bytes, 869 (unsigned long long)be64_to_cpu(rm->m_inc.i_hdr.h_sequence)); 870 871 *queued = 1; 872 } 873 874 spin_unlock_irqrestore(&rs->rs_lock, flags); 875 out: 876 return *queued; 877 } 878 879 /* 880 * rds_message is getting to be quite complicated, and we'd like to allocate 881 * it all in one go. This figures out how big it needs to be up front. 882 */ 883 static int rds_rm_size(struct msghdr *msg, int data_len) 884 { 885 struct cmsghdr *cmsg; 886 int size = 0; 887 int cmsg_groups = 0; 888 int retval; 889 890 for_each_cmsghdr(cmsg, msg) { 891 if (!CMSG_OK(msg, cmsg)) 892 return -EINVAL; 893 894 if (cmsg->cmsg_level != SOL_RDS) 895 continue; 896 897 switch (cmsg->cmsg_type) { 898 case RDS_CMSG_RDMA_ARGS: 899 cmsg_groups |= 1; 900 retval = rds_rdma_extra_size(CMSG_DATA(cmsg)); 901 if (retval < 0) 902 return retval; 903 size += retval; 904 905 break; 906 907 case RDS_CMSG_RDMA_DEST: 908 case RDS_CMSG_RDMA_MAP: 909 cmsg_groups |= 2; 910 /* these are valid but do no add any size */ 911 break; 912 913 case RDS_CMSG_ATOMIC_CSWP: 914 case RDS_CMSG_ATOMIC_FADD: 915 case RDS_CMSG_MASKED_ATOMIC_CSWP: 916 case RDS_CMSG_MASKED_ATOMIC_FADD: 917 cmsg_groups |= 1; 918 size += sizeof(struct scatterlist); 919 break; 920 921 default: 922 return -EINVAL; 923 } 924 925 } 926 927 size += ceil(data_len, PAGE_SIZE) * sizeof(struct scatterlist); 928 929 /* Ensure (DEST, MAP) are never used with (ARGS, ATOMIC) */ 930 if (cmsg_groups == 3) 931 return -EINVAL; 932 933 return size; 934 } 935 936 static int rds_cmsg_send(struct rds_sock *rs, struct rds_message *rm, 937 struct msghdr *msg, int *allocated_mr) 938 { 939 struct cmsghdr *cmsg; 940 int ret = 0; 941 942 for_each_cmsghdr(cmsg, msg) { 943 if (!CMSG_OK(msg, cmsg)) 944 return -EINVAL; 945 946 if (cmsg->cmsg_level != SOL_RDS) 947 continue; 948 949 /* As a side effect, RDMA_DEST and RDMA_MAP will set 950 * rm->rdma.m_rdma_cookie and rm->rdma.m_rdma_mr. 951 */ 952 switch (cmsg->cmsg_type) { 953 case RDS_CMSG_RDMA_ARGS: 954 ret = rds_cmsg_rdma_args(rs, rm, cmsg); 955 break; 956 957 case RDS_CMSG_RDMA_DEST: 958 ret = rds_cmsg_rdma_dest(rs, rm, cmsg); 959 break; 960 961 case RDS_CMSG_RDMA_MAP: 962 ret = rds_cmsg_rdma_map(rs, rm, cmsg); 963 if (!ret) 964 *allocated_mr = 1; 965 else if (ret == -ENODEV) 966 /* Accommodate the get_mr() case which can fail 967 * if connection isn't established yet. 968 */ 969 ret = -EAGAIN; 970 break; 971 case RDS_CMSG_ATOMIC_CSWP: 972 case RDS_CMSG_ATOMIC_FADD: 973 case RDS_CMSG_MASKED_ATOMIC_CSWP: 974 case RDS_CMSG_MASKED_ATOMIC_FADD: 975 ret = rds_cmsg_atomic(rs, rm, cmsg); 976 break; 977 978 default: 979 return -EINVAL; 980 } 981 982 if (ret) 983 break; 984 } 985 986 return ret; 987 } 988 989 static int rds_send_mprds_hash(struct rds_sock *rs, struct rds_connection *conn) 990 { 991 int hash; 992 993 if (conn->c_npaths == 0) 994 hash = RDS_MPATH_HASH(rs, RDS_MPATH_WORKERS); 995 else 996 hash = RDS_MPATH_HASH(rs, conn->c_npaths); 997 if (conn->c_npaths == 0 && hash != 0) { 998 rds_send_ping(conn, 0); 999 1000 if (conn->c_npaths == 0) { 1001 wait_event_interruptible(conn->c_hs_waitq, 1002 (conn->c_npaths != 0)); 1003 } 1004 if (conn->c_npaths == 1) 1005 hash = 0; 1006 } 1007 return hash; 1008 } 1009 1010 static int rds_rdma_bytes(struct msghdr *msg, size_t *rdma_bytes) 1011 { 1012 struct rds_rdma_args *args; 1013 struct cmsghdr *cmsg; 1014 1015 for_each_cmsghdr(cmsg, msg) { 1016 if (!CMSG_OK(msg, cmsg)) 1017 return -EINVAL; 1018 1019 if (cmsg->cmsg_level != SOL_RDS) 1020 continue; 1021 1022 if (cmsg->cmsg_type == RDS_CMSG_RDMA_ARGS) { 1023 if (cmsg->cmsg_len < 1024 CMSG_LEN(sizeof(struct rds_rdma_args))) 1025 return -EINVAL; 1026 args = CMSG_DATA(cmsg); 1027 *rdma_bytes += args->remote_vec.bytes; 1028 } 1029 } 1030 return 0; 1031 } 1032 1033 int rds_sendmsg(struct socket *sock, struct msghdr *msg, size_t payload_len) 1034 { 1035 struct sock *sk = sock->sk; 1036 struct rds_sock *rs = rds_sk_to_rs(sk); 1037 DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name); 1038 __be32 daddr; 1039 __be16 dport; 1040 struct rds_message *rm = NULL; 1041 struct rds_connection *conn; 1042 int ret = 0; 1043 int queued = 0, allocated_mr = 0; 1044 int nonblock = msg->msg_flags & MSG_DONTWAIT; 1045 long timeo = sock_sndtimeo(sk, nonblock); 1046 struct rds_conn_path *cpath; 1047 size_t total_payload_len = payload_len, rdma_payload_len = 0; 1048 1049 /* Mirror Linux UDP mirror of BSD error message compatibility */ 1050 /* XXX: Perhaps MSG_MORE someday */ 1051 if (msg->msg_flags & ~(MSG_DONTWAIT | MSG_CMSG_COMPAT)) { 1052 ret = -EOPNOTSUPP; 1053 goto out; 1054 } 1055 1056 if (msg->msg_namelen) { 1057 /* XXX fail non-unicast destination IPs? */ 1058 if (msg->msg_namelen < sizeof(*usin) || usin->sin_family != AF_INET) { 1059 ret = -EINVAL; 1060 goto out; 1061 } 1062 daddr = usin->sin_addr.s_addr; 1063 dport = usin->sin_port; 1064 } else { 1065 /* We only care about consistency with ->connect() */ 1066 lock_sock(sk); 1067 daddr = rs->rs_conn_addr; 1068 dport = rs->rs_conn_port; 1069 release_sock(sk); 1070 } 1071 1072 lock_sock(sk); 1073 if (daddr == 0 || rs->rs_bound_addr == 0) { 1074 release_sock(sk); 1075 ret = -ENOTCONN; /* XXX not a great errno */ 1076 goto out; 1077 } 1078 release_sock(sk); 1079 1080 ret = rds_rdma_bytes(msg, &rdma_payload_len); 1081 if (ret) 1082 goto out; 1083 1084 total_payload_len += rdma_payload_len; 1085 if (max_t(size_t, payload_len, rdma_payload_len) > RDS_MAX_MSG_SIZE) { 1086 ret = -EMSGSIZE; 1087 goto out; 1088 } 1089 1090 if (payload_len > rds_sk_sndbuf(rs)) { 1091 ret = -EMSGSIZE; 1092 goto out; 1093 } 1094 1095 /* size of rm including all sgs */ 1096 ret = rds_rm_size(msg, payload_len); 1097 if (ret < 0) 1098 goto out; 1099 1100 rm = rds_message_alloc(ret, GFP_KERNEL); 1101 if (!rm) { 1102 ret = -ENOMEM; 1103 goto out; 1104 } 1105 1106 /* Attach data to the rm */ 1107 if (payload_len) { 1108 rm->data.op_sg = rds_message_alloc_sgs(rm, ceil(payload_len, PAGE_SIZE)); 1109 if (!rm->data.op_sg) { 1110 ret = -ENOMEM; 1111 goto out; 1112 } 1113 ret = rds_message_copy_from_user(rm, &msg->msg_iter); 1114 if (ret) 1115 goto out; 1116 } 1117 rm->data.op_active = 1; 1118 1119 rm->m_daddr = daddr; 1120 1121 /* rds_conn_create has a spinlock that runs with IRQ off. 1122 * Caching the conn in the socket helps a lot. */ 1123 if (rs->rs_conn && rs->rs_conn->c_faddr == daddr) 1124 conn = rs->rs_conn; 1125 else { 1126 conn = rds_conn_create_outgoing(sock_net(sock->sk), 1127 rs->rs_bound_addr, daddr, 1128 rs->rs_transport, 1129 sock->sk->sk_allocation); 1130 if (IS_ERR(conn)) { 1131 ret = PTR_ERR(conn); 1132 goto out; 1133 } 1134 rs->rs_conn = conn; 1135 } 1136 1137 /* Parse any control messages the user may have included. */ 1138 ret = rds_cmsg_send(rs, rm, msg, &allocated_mr); 1139 if (ret) { 1140 /* Trigger connection so that its ready for the next retry */ 1141 if (ret == -EAGAIN) 1142 rds_conn_connect_if_down(conn); 1143 goto out; 1144 } 1145 1146 if (rm->rdma.op_active && !conn->c_trans->xmit_rdma) { 1147 printk_ratelimited(KERN_NOTICE "rdma_op %p conn xmit_rdma %p\n", 1148 &rm->rdma, conn->c_trans->xmit_rdma); 1149 ret = -EOPNOTSUPP; 1150 goto out; 1151 } 1152 1153 if (rm->atomic.op_active && !conn->c_trans->xmit_atomic) { 1154 printk_ratelimited(KERN_NOTICE "atomic_op %p conn xmit_atomic %p\n", 1155 &rm->atomic, conn->c_trans->xmit_atomic); 1156 ret = -EOPNOTSUPP; 1157 goto out; 1158 } 1159 1160 if (conn->c_trans->t_mp_capable) 1161 cpath = &conn->c_path[rds_send_mprds_hash(rs, conn)]; 1162 else 1163 cpath = &conn->c_path[0]; 1164 1165 if (rds_destroy_pending(conn)) { 1166 ret = -EAGAIN; 1167 goto out; 1168 } 1169 1170 rds_conn_path_connect_if_down(cpath); 1171 1172 ret = rds_cong_wait(conn->c_fcong, dport, nonblock, rs); 1173 if (ret) { 1174 rs->rs_seen_congestion = 1; 1175 goto out; 1176 } 1177 while (!rds_send_queue_rm(rs, conn, cpath, rm, rs->rs_bound_port, 1178 dport, &queued)) { 1179 rds_stats_inc(s_send_queue_full); 1180 1181 if (nonblock) { 1182 ret = -EAGAIN; 1183 goto out; 1184 } 1185 1186 timeo = wait_event_interruptible_timeout(*sk_sleep(sk), 1187 rds_send_queue_rm(rs, conn, cpath, rm, 1188 rs->rs_bound_port, 1189 dport, 1190 &queued), 1191 timeo); 1192 rdsdebug("sendmsg woke queued %d timeo %ld\n", queued, timeo); 1193 if (timeo > 0 || timeo == MAX_SCHEDULE_TIMEOUT) 1194 continue; 1195 1196 ret = timeo; 1197 if (ret == 0) 1198 ret = -ETIMEDOUT; 1199 goto out; 1200 } 1201 1202 /* 1203 * By now we've committed to the send. We reuse rds_send_worker() 1204 * to retry sends in the rds thread if the transport asks us to. 1205 */ 1206 rds_stats_inc(s_send_queued); 1207 1208 ret = rds_send_xmit(cpath); 1209 if (ret == -ENOMEM || ret == -EAGAIN) { 1210 ret = 0; 1211 rcu_read_lock(); 1212 if (rds_destroy_pending(cpath->cp_conn)) 1213 ret = -ENETUNREACH; 1214 else 1215 queue_delayed_work(rds_wq, &cpath->cp_send_w, 1); 1216 rcu_read_unlock(); 1217 } 1218 if (ret) 1219 goto out; 1220 rds_message_put(rm); 1221 return payload_len; 1222 1223 out: 1224 /* If the user included a RDMA_MAP cmsg, we allocated a MR on the fly. 1225 * If the sendmsg goes through, we keep the MR. If it fails with EAGAIN 1226 * or in any other way, we need to destroy the MR again */ 1227 if (allocated_mr) 1228 rds_rdma_unuse(rs, rds_rdma_cookie_key(rm->m_rdma_cookie), 1); 1229 1230 if (rm) 1231 rds_message_put(rm); 1232 return ret; 1233 } 1234 1235 /* 1236 * send out a probe. Can be shared by rds_send_ping, 1237 * rds_send_pong, rds_send_hb. 1238 * rds_send_hb should use h_flags 1239 * RDS_FLAG_HB_PING|RDS_FLAG_ACK_REQUIRED 1240 * or 1241 * RDS_FLAG_HB_PONG|RDS_FLAG_ACK_REQUIRED 1242 */ 1243 static int 1244 rds_send_probe(struct rds_conn_path *cp, __be16 sport, 1245 __be16 dport, u8 h_flags) 1246 { 1247 struct rds_message *rm; 1248 unsigned long flags; 1249 int ret = 0; 1250 1251 rm = rds_message_alloc(0, GFP_ATOMIC); 1252 if (!rm) { 1253 ret = -ENOMEM; 1254 goto out; 1255 } 1256 1257 rm->m_daddr = cp->cp_conn->c_faddr; 1258 rm->data.op_active = 1; 1259 1260 rds_conn_path_connect_if_down(cp); 1261 1262 ret = rds_cong_wait(cp->cp_conn->c_fcong, dport, 1, NULL); 1263 if (ret) 1264 goto out; 1265 1266 spin_lock_irqsave(&cp->cp_lock, flags); 1267 list_add_tail(&rm->m_conn_item, &cp->cp_send_queue); 1268 set_bit(RDS_MSG_ON_CONN, &rm->m_flags); 1269 rds_message_addref(rm); 1270 rm->m_inc.i_conn = cp->cp_conn; 1271 rm->m_inc.i_conn_path = cp; 1272 1273 rds_message_populate_header(&rm->m_inc.i_hdr, sport, dport, 1274 cp->cp_next_tx_seq); 1275 rm->m_inc.i_hdr.h_flags |= h_flags; 1276 cp->cp_next_tx_seq++; 1277 1278 if (RDS_HS_PROBE(be16_to_cpu(sport), be16_to_cpu(dport)) && 1279 cp->cp_conn->c_trans->t_mp_capable) { 1280 u16 npaths = cpu_to_be16(RDS_MPATH_WORKERS); 1281 u32 my_gen_num = cpu_to_be32(cp->cp_conn->c_my_gen_num); 1282 1283 rds_message_add_extension(&rm->m_inc.i_hdr, 1284 RDS_EXTHDR_NPATHS, &npaths, 1285 sizeof(npaths)); 1286 rds_message_add_extension(&rm->m_inc.i_hdr, 1287 RDS_EXTHDR_GEN_NUM, 1288 &my_gen_num, 1289 sizeof(u32)); 1290 } 1291 spin_unlock_irqrestore(&cp->cp_lock, flags); 1292 1293 rds_stats_inc(s_send_queued); 1294 rds_stats_inc(s_send_pong); 1295 1296 /* schedule the send work on rds_wq */ 1297 rcu_read_lock(); 1298 if (!rds_destroy_pending(cp->cp_conn)) 1299 queue_delayed_work(rds_wq, &cp->cp_send_w, 1); 1300 rcu_read_unlock(); 1301 1302 rds_message_put(rm); 1303 return 0; 1304 1305 out: 1306 if (rm) 1307 rds_message_put(rm); 1308 return ret; 1309 } 1310 1311 int 1312 rds_send_pong(struct rds_conn_path *cp, __be16 dport) 1313 { 1314 return rds_send_probe(cp, 0, dport, 0); 1315 } 1316 1317 void 1318 rds_send_ping(struct rds_connection *conn, int cp_index) 1319 { 1320 unsigned long flags; 1321 struct rds_conn_path *cp = &conn->c_path[cp_index]; 1322 1323 spin_lock_irqsave(&cp->cp_lock, flags); 1324 if (conn->c_ping_triggered) { 1325 spin_unlock_irqrestore(&cp->cp_lock, flags); 1326 return; 1327 } 1328 conn->c_ping_triggered = 1; 1329 spin_unlock_irqrestore(&cp->cp_lock, flags); 1330 rds_send_probe(cp, cpu_to_be16(RDS_FLAG_PROBE_PORT), 0, 0); 1331 } 1332 EXPORT_SYMBOL_GPL(rds_send_ping); 1333