1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * RDMA Transport Layer 4 * 5 * Copyright (c) 2014 - 2018 ProfitBricks GmbH. All rights reserved. 6 * Copyright (c) 2018 - 2019 1&1 IONOS Cloud GmbH. All rights reserved. 7 * Copyright (c) 2019 - 2020 1&1 IONOS SE. All rights reserved. 8 */ 9 10 #undef pr_fmt 11 #define pr_fmt(fmt) KBUILD_MODNAME " L" __stringify(__LINE__) ": " fmt 12 13 #include <linux/module.h> 14 #include <linux/rculist.h> 15 #include <linux/random.h> 16 17 #include "rtrs-clt.h" 18 #include "rtrs-log.h" 19 20 #define RTRS_CONNECT_TIMEOUT_MS 30000 21 /* 22 * Wait a bit before trying to reconnect after a failure 23 * in order to give server time to finish clean up which 24 * leads to "false positives" failed reconnect attempts 25 */ 26 #define RTRS_RECONNECT_BACKOFF 1000 27 /* 28 * Wait for additional random time between 0 and 8 seconds 29 * before starting to reconnect to avoid clients reconnecting 30 * all at once in case of a major network outage 31 */ 32 #define RTRS_RECONNECT_SEED 8 33 34 #define FIRST_CONN 0x01 35 /* limit to 128 * 4k = 512k max IO */ 36 #define RTRS_MAX_SEGMENTS 128 37 38 MODULE_DESCRIPTION("RDMA Transport Client"); 39 MODULE_LICENSE("GPL"); 40 41 static const struct rtrs_rdma_dev_pd_ops dev_pd_ops; 42 static struct rtrs_rdma_dev_pd dev_pd = { 43 .ops = &dev_pd_ops 44 }; 45 46 static struct workqueue_struct *rtrs_wq; 47 static struct class *rtrs_clt_dev_class; 48 49 static inline bool rtrs_clt_is_connected(const struct rtrs_clt_sess *clt) 50 { 51 struct rtrs_clt_path *clt_path; 52 bool connected = false; 53 54 rcu_read_lock(); 55 list_for_each_entry_rcu(clt_path, &clt->paths_list, s.entry) 56 connected |= READ_ONCE(clt_path->state) == RTRS_CLT_CONNECTED; 57 rcu_read_unlock(); 58 59 return connected; 60 } 61 62 static struct rtrs_permit * 63 __rtrs_get_permit(struct rtrs_clt_sess *clt, enum rtrs_clt_con_type con_type) 64 { 65 size_t max_depth = clt->queue_depth; 66 struct rtrs_permit *permit; 67 int bit; 68 69 /* 70 * Adapted from null_blk get_tag(). Callers from different cpus may 71 * grab the same bit, since find_first_zero_bit is not atomic. 72 * But then the test_and_set_bit_lock will fail for all the 73 * callers but one, so that they will loop again. 74 * This way an explicit spinlock is not required. 75 */ 76 do { 77 bit = find_first_zero_bit(clt->permits_map, max_depth); 78 if (bit >= max_depth) 79 return NULL; 80 } while (test_and_set_bit_lock(bit, clt->permits_map)); 81 82 permit = get_permit(clt, bit); 83 WARN_ON(permit->mem_id != bit); 84 permit->cpu_id = raw_smp_processor_id(); 85 permit->con_type = con_type; 86 87 return permit; 88 } 89 90 static inline void __rtrs_put_permit(struct rtrs_clt_sess *clt, 91 struct rtrs_permit *permit) 92 { 93 clear_bit_unlock(permit->mem_id, clt->permits_map); 94 } 95 96 /** 97 * rtrs_clt_get_permit() - allocates permit for future RDMA operation 98 * @clt: Current session 99 * @con_type: Type of connection to use with the permit 100 * @can_wait: Wait type 101 * 102 * Description: 103 * Allocates permit for the following RDMA operation. Permit is used 104 * to preallocate all resources and to propagate memory pressure 105 * up earlier. 106 * 107 * Context: 108 * Can sleep if @wait == RTRS_PERMIT_WAIT 109 */ 110 struct rtrs_permit *rtrs_clt_get_permit(struct rtrs_clt_sess *clt, 111 enum rtrs_clt_con_type con_type, 112 enum wait_type can_wait) 113 { 114 struct rtrs_permit *permit; 115 DEFINE_WAIT(wait); 116 117 permit = __rtrs_get_permit(clt, con_type); 118 if (permit || !can_wait) 119 return permit; 120 121 do { 122 prepare_to_wait(&clt->permits_wait, &wait, 123 TASK_UNINTERRUPTIBLE); 124 permit = __rtrs_get_permit(clt, con_type); 125 if (permit) 126 break; 127 128 io_schedule(); 129 } while (1); 130 131 finish_wait(&clt->permits_wait, &wait); 132 133 return permit; 134 } 135 EXPORT_SYMBOL(rtrs_clt_get_permit); 136 137 /** 138 * rtrs_clt_put_permit() - puts allocated permit 139 * @clt: Current session 140 * @permit: Permit to be freed 141 * 142 * Context: 143 * Does not matter 144 */ 145 void rtrs_clt_put_permit(struct rtrs_clt_sess *clt, 146 struct rtrs_permit *permit) 147 { 148 if (WARN_ON(!test_bit(permit->mem_id, clt->permits_map))) 149 return; 150 151 __rtrs_put_permit(clt, permit); 152 153 /* 154 * rtrs_clt_get_permit() adds itself to the &clt->permits_wait list 155 * before calling schedule(). So if rtrs_clt_get_permit() is sleeping 156 * it must have added itself to &clt->permits_wait before 157 * __rtrs_put_permit() finished. 158 * Hence it is safe to guard wake_up() with a waitqueue_active() test. 159 */ 160 if (waitqueue_active(&clt->permits_wait)) 161 wake_up(&clt->permits_wait); 162 } 163 EXPORT_SYMBOL(rtrs_clt_put_permit); 164 165 /** 166 * rtrs_permit_to_clt_con() - returns RDMA connection pointer by the permit 167 * @clt_path: client path pointer 168 * @permit: permit for the allocation of the RDMA buffer 169 * Note: 170 * IO connection starts from 1. 171 * 0 connection is for user messages. 172 */ 173 static 174 struct rtrs_clt_con *rtrs_permit_to_clt_con(struct rtrs_clt_path *clt_path, 175 struct rtrs_permit *permit) 176 { 177 int id = 0; 178 179 if (permit->con_type == RTRS_IO_CON) 180 id = (permit->cpu_id % (clt_path->s.irq_con_num - 1)) + 1; 181 182 return to_clt_con(clt_path->s.con[id]); 183 } 184 185 /** 186 * rtrs_clt_change_state() - change the session state through session state 187 * machine. 188 * 189 * @clt_path: client path to change the state of. 190 * @new_state: state to change to. 191 * 192 * returns true if sess's state is changed to new state, otherwise return false. 193 * 194 * Locks: 195 * state_wq lock must be hold. 196 */ 197 static bool rtrs_clt_change_state(struct rtrs_clt_path *clt_path, 198 enum rtrs_clt_state new_state) 199 { 200 enum rtrs_clt_state old_state; 201 bool changed = false; 202 203 lockdep_assert_held(&clt_path->state_wq.lock); 204 205 old_state = clt_path->state; 206 switch (new_state) { 207 case RTRS_CLT_CONNECTING: 208 switch (old_state) { 209 case RTRS_CLT_RECONNECTING: 210 changed = true; 211 fallthrough; 212 default: 213 break; 214 } 215 break; 216 case RTRS_CLT_RECONNECTING: 217 switch (old_state) { 218 case RTRS_CLT_CONNECTED: 219 case RTRS_CLT_CONNECTING_ERR: 220 case RTRS_CLT_CLOSED: 221 changed = true; 222 fallthrough; 223 default: 224 break; 225 } 226 break; 227 case RTRS_CLT_CONNECTED: 228 switch (old_state) { 229 case RTRS_CLT_CONNECTING: 230 changed = true; 231 fallthrough; 232 default: 233 break; 234 } 235 break; 236 case RTRS_CLT_CONNECTING_ERR: 237 switch (old_state) { 238 case RTRS_CLT_CONNECTING: 239 changed = true; 240 fallthrough; 241 default: 242 break; 243 } 244 break; 245 case RTRS_CLT_CLOSING: 246 switch (old_state) { 247 case RTRS_CLT_CONNECTING: 248 case RTRS_CLT_CONNECTING_ERR: 249 case RTRS_CLT_RECONNECTING: 250 case RTRS_CLT_CONNECTED: 251 changed = true; 252 fallthrough; 253 default: 254 break; 255 } 256 break; 257 case RTRS_CLT_CLOSED: 258 switch (old_state) { 259 case RTRS_CLT_CLOSING: 260 changed = true; 261 fallthrough; 262 default: 263 break; 264 } 265 break; 266 case RTRS_CLT_DEAD: 267 switch (old_state) { 268 case RTRS_CLT_CLOSED: 269 changed = true; 270 fallthrough; 271 default: 272 break; 273 } 274 break; 275 default: 276 break; 277 } 278 if (changed) { 279 clt_path->state = new_state; 280 wake_up_locked(&clt_path->state_wq); 281 } 282 283 return changed; 284 } 285 286 static bool rtrs_clt_change_state_from_to(struct rtrs_clt_path *clt_path, 287 enum rtrs_clt_state old_state, 288 enum rtrs_clt_state new_state) 289 { 290 bool changed = false; 291 292 spin_lock_irq(&clt_path->state_wq.lock); 293 if (clt_path->state == old_state) 294 changed = rtrs_clt_change_state(clt_path, new_state); 295 spin_unlock_irq(&clt_path->state_wq.lock); 296 297 return changed; 298 } 299 300 static void rtrs_rdma_error_recovery(struct rtrs_clt_con *con) 301 { 302 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path); 303 304 if (rtrs_clt_change_state_from_to(clt_path, 305 RTRS_CLT_CONNECTED, 306 RTRS_CLT_RECONNECTING)) { 307 struct rtrs_clt_sess *clt = clt_path->clt; 308 unsigned int delay_ms; 309 310 /* 311 * Normal scenario, reconnect if we were successfully connected 312 */ 313 delay_ms = clt->reconnect_delay_sec * 1000; 314 queue_delayed_work(rtrs_wq, &clt_path->reconnect_dwork, 315 msecs_to_jiffies(delay_ms + 316 prandom_u32() % RTRS_RECONNECT_SEED)); 317 } else { 318 /* 319 * Error can happen just on establishing new connection, 320 * so notify waiter with error state, waiter is responsible 321 * for cleaning the rest and reconnect if needed. 322 */ 323 rtrs_clt_change_state_from_to(clt_path, 324 RTRS_CLT_CONNECTING, 325 RTRS_CLT_CONNECTING_ERR); 326 } 327 } 328 329 static void rtrs_clt_fast_reg_done(struct ib_cq *cq, struct ib_wc *wc) 330 { 331 struct rtrs_clt_con *con = to_clt_con(wc->qp->qp_context); 332 333 if (wc->status != IB_WC_SUCCESS) { 334 rtrs_err(con->c.path, "Failed IB_WR_REG_MR: %s\n", 335 ib_wc_status_msg(wc->status)); 336 rtrs_rdma_error_recovery(con); 337 } 338 } 339 340 static struct ib_cqe fast_reg_cqe = { 341 .done = rtrs_clt_fast_reg_done 342 }; 343 344 static void complete_rdma_req(struct rtrs_clt_io_req *req, int errno, 345 bool notify, bool can_wait); 346 347 static void rtrs_clt_inv_rkey_done(struct ib_cq *cq, struct ib_wc *wc) 348 { 349 struct rtrs_clt_io_req *req = 350 container_of(wc->wr_cqe, typeof(*req), inv_cqe); 351 struct rtrs_clt_con *con = to_clt_con(wc->qp->qp_context); 352 353 if (wc->status != IB_WC_SUCCESS) { 354 rtrs_err(con->c.path, "Failed IB_WR_LOCAL_INV: %s\n", 355 ib_wc_status_msg(wc->status)); 356 rtrs_rdma_error_recovery(con); 357 } 358 req->need_inv = false; 359 if (req->need_inv_comp) 360 complete(&req->inv_comp); 361 else 362 /* Complete request from INV callback */ 363 complete_rdma_req(req, req->inv_errno, true, false); 364 } 365 366 static int rtrs_inv_rkey(struct rtrs_clt_io_req *req) 367 { 368 struct rtrs_clt_con *con = req->con; 369 struct ib_send_wr wr = { 370 .opcode = IB_WR_LOCAL_INV, 371 .wr_cqe = &req->inv_cqe, 372 .send_flags = IB_SEND_SIGNALED, 373 .ex.invalidate_rkey = req->mr->rkey, 374 }; 375 req->inv_cqe.done = rtrs_clt_inv_rkey_done; 376 377 return ib_post_send(con->c.qp, &wr, NULL); 378 } 379 380 static void complete_rdma_req(struct rtrs_clt_io_req *req, int errno, 381 bool notify, bool can_wait) 382 { 383 struct rtrs_clt_con *con = req->con; 384 struct rtrs_clt_path *clt_path; 385 int err; 386 387 if (WARN_ON(!req->in_use)) 388 return; 389 if (WARN_ON(!req->con)) 390 return; 391 clt_path = to_clt_path(con->c.path); 392 393 if (req->sg_cnt) { 394 if (req->dir == DMA_FROM_DEVICE && req->need_inv) { 395 /* 396 * We are here to invalidate read requests 397 * ourselves. In normal scenario server should 398 * send INV for all read requests, but 399 * we are here, thus two things could happen: 400 * 401 * 1. this is failover, when errno != 0 402 * and can_wait == 1, 403 * 404 * 2. something totally bad happened and 405 * server forgot to send INV, so we 406 * should do that ourselves. 407 */ 408 409 if (can_wait) { 410 req->need_inv_comp = true; 411 } else { 412 /* This should be IO path, so always notify */ 413 WARN_ON(!notify); 414 /* Save errno for INV callback */ 415 req->inv_errno = errno; 416 } 417 418 refcount_inc(&req->ref); 419 err = rtrs_inv_rkey(req); 420 if (err) { 421 rtrs_err(con->c.path, "Send INV WR key=%#x: %d\n", 422 req->mr->rkey, err); 423 } else if (can_wait) { 424 wait_for_completion(&req->inv_comp); 425 } else { 426 /* 427 * Something went wrong, so request will be 428 * completed from INV callback. 429 */ 430 WARN_ON_ONCE(1); 431 432 return; 433 } 434 if (!refcount_dec_and_test(&req->ref)) 435 return; 436 } 437 ib_dma_unmap_sg(clt_path->s.dev->ib_dev, req->sglist, 438 req->sg_cnt, req->dir); 439 } 440 if (!refcount_dec_and_test(&req->ref)) 441 return; 442 if (req->mp_policy == MP_POLICY_MIN_INFLIGHT) 443 atomic_dec(&clt_path->stats->inflight); 444 445 req->in_use = false; 446 req->con = NULL; 447 448 if (errno) { 449 rtrs_err_rl(con->c.path, "IO request failed: error=%d path=%s [%s:%u] notify=%d\n", 450 errno, kobject_name(&clt_path->kobj), clt_path->hca_name, 451 clt_path->hca_port, notify); 452 } 453 454 if (notify) 455 req->conf(req->priv, errno); 456 } 457 458 static int rtrs_post_send_rdma(struct rtrs_clt_con *con, 459 struct rtrs_clt_io_req *req, 460 struct rtrs_rbuf *rbuf, u32 off, 461 u32 imm, struct ib_send_wr *wr) 462 { 463 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path); 464 enum ib_send_flags flags; 465 struct ib_sge sge; 466 467 if (!req->sg_size) { 468 rtrs_wrn(con->c.path, 469 "Doing RDMA Write failed, no data supplied\n"); 470 return -EINVAL; 471 } 472 473 /* user data and user message in the first list element */ 474 sge.addr = req->iu->dma_addr; 475 sge.length = req->sg_size; 476 sge.lkey = clt_path->s.dev->ib_pd->local_dma_lkey; 477 478 /* 479 * From time to time we have to post signalled sends, 480 * or send queue will fill up and only QP reset can help. 481 */ 482 flags = atomic_inc_return(&con->c.wr_cnt) % clt_path->s.signal_interval ? 483 0 : IB_SEND_SIGNALED; 484 485 ib_dma_sync_single_for_device(clt_path->s.dev->ib_dev, 486 req->iu->dma_addr, 487 req->sg_size, DMA_TO_DEVICE); 488 489 return rtrs_iu_post_rdma_write_imm(&con->c, req->iu, &sge, 1, 490 rbuf->rkey, rbuf->addr + off, 491 imm, flags, wr, NULL); 492 } 493 494 static void process_io_rsp(struct rtrs_clt_path *clt_path, u32 msg_id, 495 s16 errno, bool w_inval) 496 { 497 struct rtrs_clt_io_req *req; 498 499 if (WARN_ON(msg_id >= clt_path->queue_depth)) 500 return; 501 502 req = &clt_path->reqs[msg_id]; 503 /* Drop need_inv if server responded with send with invalidation */ 504 req->need_inv &= !w_inval; 505 complete_rdma_req(req, errno, true, false); 506 } 507 508 static void rtrs_clt_recv_done(struct rtrs_clt_con *con, struct ib_wc *wc) 509 { 510 struct rtrs_iu *iu; 511 int err; 512 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path); 513 514 WARN_ON((clt_path->flags & RTRS_MSG_NEW_RKEY_F) == 0); 515 iu = container_of(wc->wr_cqe, struct rtrs_iu, 516 cqe); 517 err = rtrs_iu_post_recv(&con->c, iu); 518 if (err) { 519 rtrs_err(con->c.path, "post iu failed %d\n", err); 520 rtrs_rdma_error_recovery(con); 521 } 522 } 523 524 static void rtrs_clt_rkey_rsp_done(struct rtrs_clt_con *con, struct ib_wc *wc) 525 { 526 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path); 527 struct rtrs_msg_rkey_rsp *msg; 528 u32 imm_type, imm_payload; 529 bool w_inval = false; 530 struct rtrs_iu *iu; 531 u32 buf_id; 532 int err; 533 534 WARN_ON((clt_path->flags & RTRS_MSG_NEW_RKEY_F) == 0); 535 536 iu = container_of(wc->wr_cqe, struct rtrs_iu, cqe); 537 538 if (wc->byte_len < sizeof(*msg)) { 539 rtrs_err(con->c.path, "rkey response is malformed: size %d\n", 540 wc->byte_len); 541 goto out; 542 } 543 ib_dma_sync_single_for_cpu(clt_path->s.dev->ib_dev, iu->dma_addr, 544 iu->size, DMA_FROM_DEVICE); 545 msg = iu->buf; 546 if (le16_to_cpu(msg->type) != RTRS_MSG_RKEY_RSP) { 547 rtrs_err(clt_path->clt, 548 "rkey response is malformed: type %d\n", 549 le16_to_cpu(msg->type)); 550 goto out; 551 } 552 buf_id = le16_to_cpu(msg->buf_id); 553 if (WARN_ON(buf_id >= clt_path->queue_depth)) 554 goto out; 555 556 rtrs_from_imm(be32_to_cpu(wc->ex.imm_data), &imm_type, &imm_payload); 557 if (imm_type == RTRS_IO_RSP_IMM || 558 imm_type == RTRS_IO_RSP_W_INV_IMM) { 559 u32 msg_id; 560 561 w_inval = (imm_type == RTRS_IO_RSP_W_INV_IMM); 562 rtrs_from_io_rsp_imm(imm_payload, &msg_id, &err); 563 564 if (WARN_ON(buf_id != msg_id)) 565 goto out; 566 clt_path->rbufs[buf_id].rkey = le32_to_cpu(msg->rkey); 567 process_io_rsp(clt_path, msg_id, err, w_inval); 568 } 569 ib_dma_sync_single_for_device(clt_path->s.dev->ib_dev, iu->dma_addr, 570 iu->size, DMA_FROM_DEVICE); 571 return rtrs_clt_recv_done(con, wc); 572 out: 573 rtrs_rdma_error_recovery(con); 574 } 575 576 static void rtrs_clt_rdma_done(struct ib_cq *cq, struct ib_wc *wc); 577 578 static struct ib_cqe io_comp_cqe = { 579 .done = rtrs_clt_rdma_done 580 }; 581 582 /* 583 * Post x2 empty WRs: first is for this RDMA with IMM, 584 * second is for RECV with INV, which happened earlier. 585 */ 586 static int rtrs_post_recv_empty_x2(struct rtrs_con *con, struct ib_cqe *cqe) 587 { 588 struct ib_recv_wr wr_arr[2], *wr; 589 int i; 590 591 memset(wr_arr, 0, sizeof(wr_arr)); 592 for (i = 0; i < ARRAY_SIZE(wr_arr); i++) { 593 wr = &wr_arr[i]; 594 wr->wr_cqe = cqe; 595 if (i) 596 /* Chain backwards */ 597 wr->next = &wr_arr[i - 1]; 598 } 599 600 return ib_post_recv(con->qp, wr, NULL); 601 } 602 603 static void rtrs_clt_rdma_done(struct ib_cq *cq, struct ib_wc *wc) 604 { 605 struct rtrs_clt_con *con = to_clt_con(wc->qp->qp_context); 606 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path); 607 u32 imm_type, imm_payload; 608 bool w_inval = false; 609 int err; 610 611 if (wc->status != IB_WC_SUCCESS) { 612 if (wc->status != IB_WC_WR_FLUSH_ERR) { 613 rtrs_err(clt_path->clt, "RDMA failed: %s\n", 614 ib_wc_status_msg(wc->status)); 615 rtrs_rdma_error_recovery(con); 616 } 617 return; 618 } 619 rtrs_clt_update_wc_stats(con); 620 621 switch (wc->opcode) { 622 case IB_WC_RECV_RDMA_WITH_IMM: 623 /* 624 * post_recv() RDMA write completions of IO reqs (read/write) 625 * and hb 626 */ 627 if (WARN_ON(wc->wr_cqe->done != rtrs_clt_rdma_done)) 628 return; 629 rtrs_from_imm(be32_to_cpu(wc->ex.imm_data), 630 &imm_type, &imm_payload); 631 if (imm_type == RTRS_IO_RSP_IMM || 632 imm_type == RTRS_IO_RSP_W_INV_IMM) { 633 u32 msg_id; 634 635 w_inval = (imm_type == RTRS_IO_RSP_W_INV_IMM); 636 rtrs_from_io_rsp_imm(imm_payload, &msg_id, &err); 637 638 process_io_rsp(clt_path, msg_id, err, w_inval); 639 } else if (imm_type == RTRS_HB_MSG_IMM) { 640 WARN_ON(con->c.cid); 641 rtrs_send_hb_ack(&clt_path->s); 642 if (clt_path->flags & RTRS_MSG_NEW_RKEY_F) 643 return rtrs_clt_recv_done(con, wc); 644 } else if (imm_type == RTRS_HB_ACK_IMM) { 645 WARN_ON(con->c.cid); 646 clt_path->s.hb_missed_cnt = 0; 647 clt_path->s.hb_cur_latency = 648 ktime_sub(ktime_get(), clt_path->s.hb_last_sent); 649 if (clt_path->flags & RTRS_MSG_NEW_RKEY_F) 650 return rtrs_clt_recv_done(con, wc); 651 } else { 652 rtrs_wrn(con->c.path, "Unknown IMM type %u\n", 653 imm_type); 654 } 655 if (w_inval) 656 /* 657 * Post x2 empty WRs: first is for this RDMA with IMM, 658 * second is for RECV with INV, which happened earlier. 659 */ 660 err = rtrs_post_recv_empty_x2(&con->c, &io_comp_cqe); 661 else 662 err = rtrs_post_recv_empty(&con->c, &io_comp_cqe); 663 if (err) { 664 rtrs_err(con->c.path, "rtrs_post_recv_empty(): %d\n", 665 err); 666 rtrs_rdma_error_recovery(con); 667 } 668 break; 669 case IB_WC_RECV: 670 /* 671 * Key invalidations from server side 672 */ 673 WARN_ON(!(wc->wc_flags & IB_WC_WITH_INVALIDATE || 674 wc->wc_flags & IB_WC_WITH_IMM)); 675 WARN_ON(wc->wr_cqe->done != rtrs_clt_rdma_done); 676 if (clt_path->flags & RTRS_MSG_NEW_RKEY_F) { 677 if (wc->wc_flags & IB_WC_WITH_INVALIDATE) 678 return rtrs_clt_recv_done(con, wc); 679 680 return rtrs_clt_rkey_rsp_done(con, wc); 681 } 682 break; 683 case IB_WC_RDMA_WRITE: 684 /* 685 * post_send() RDMA write completions of IO reqs (read/write) 686 * and hb. 687 */ 688 break; 689 690 default: 691 rtrs_wrn(clt_path->clt, "Unexpected WC type: %d\n", wc->opcode); 692 return; 693 } 694 } 695 696 static int post_recv_io(struct rtrs_clt_con *con, size_t q_size) 697 { 698 int err, i; 699 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path); 700 701 for (i = 0; i < q_size; i++) { 702 if (clt_path->flags & RTRS_MSG_NEW_RKEY_F) { 703 struct rtrs_iu *iu = &con->rsp_ius[i]; 704 705 err = rtrs_iu_post_recv(&con->c, iu); 706 } else { 707 err = rtrs_post_recv_empty(&con->c, &io_comp_cqe); 708 } 709 if (err) 710 return err; 711 } 712 713 return 0; 714 } 715 716 static int post_recv_path(struct rtrs_clt_path *clt_path) 717 { 718 size_t q_size = 0; 719 int err, cid; 720 721 for (cid = 0; cid < clt_path->s.con_num; cid++) { 722 if (cid == 0) 723 q_size = SERVICE_CON_QUEUE_DEPTH; 724 else 725 q_size = clt_path->queue_depth; 726 727 /* 728 * x2 for RDMA read responses + FR key invalidations, 729 * RDMA writes do not require any FR registrations. 730 */ 731 q_size *= 2; 732 733 err = post_recv_io(to_clt_con(clt_path->s.con[cid]), q_size); 734 if (err) { 735 rtrs_err(clt_path->clt, "post_recv_io(), err: %d\n", 736 err); 737 return err; 738 } 739 } 740 741 return 0; 742 } 743 744 struct path_it { 745 int i; 746 struct list_head skip_list; 747 struct rtrs_clt_sess *clt; 748 struct rtrs_clt_path *(*next_path)(struct path_it *it); 749 }; 750 751 /** 752 * list_next_or_null_rr_rcu - get next list element in round-robin fashion. 753 * @head: the head for the list. 754 * @ptr: the list head to take the next element from. 755 * @type: the type of the struct this is embedded in. 756 * @memb: the name of the list_head within the struct. 757 * 758 * Next element returned in round-robin fashion, i.e. head will be skipped, 759 * but if list is observed as empty, NULL will be returned. 760 * 761 * This primitive may safely run concurrently with the _rcu list-mutation 762 * primitives such as list_add_rcu() as long as it's guarded by rcu_read_lock(). 763 */ 764 #define list_next_or_null_rr_rcu(head, ptr, type, memb) \ 765 ({ \ 766 list_next_or_null_rcu(head, ptr, type, memb) ?: \ 767 list_next_or_null_rcu(head, READ_ONCE((ptr)->next), \ 768 type, memb); \ 769 }) 770 771 /** 772 * get_next_path_rr() - Returns path in round-robin fashion. 773 * @it: the path pointer 774 * 775 * Related to @MP_POLICY_RR 776 * 777 * Locks: 778 * rcu_read_lock() must be hold. 779 */ 780 static struct rtrs_clt_path *get_next_path_rr(struct path_it *it) 781 { 782 struct rtrs_clt_path __rcu **ppcpu_path; 783 struct rtrs_clt_path *path; 784 struct rtrs_clt_sess *clt; 785 786 clt = it->clt; 787 788 /* 789 * Here we use two RCU objects: @paths_list and @pcpu_path 790 * pointer. See rtrs_clt_remove_path_from_arr() for details 791 * how that is handled. 792 */ 793 794 ppcpu_path = this_cpu_ptr(clt->pcpu_path); 795 path = rcu_dereference(*ppcpu_path); 796 if (!path) 797 path = list_first_or_null_rcu(&clt->paths_list, 798 typeof(*path), s.entry); 799 else 800 path = list_next_or_null_rr_rcu(&clt->paths_list, 801 &path->s.entry, 802 typeof(*path), 803 s.entry); 804 rcu_assign_pointer(*ppcpu_path, path); 805 806 return path; 807 } 808 809 /** 810 * get_next_path_min_inflight() - Returns path with minimal inflight count. 811 * @it: the path pointer 812 * 813 * Related to @MP_POLICY_MIN_INFLIGHT 814 * 815 * Locks: 816 * rcu_read_lock() must be hold. 817 */ 818 static struct rtrs_clt_path *get_next_path_min_inflight(struct path_it *it) 819 { 820 struct rtrs_clt_path *min_path = NULL; 821 struct rtrs_clt_sess *clt = it->clt; 822 struct rtrs_clt_path *clt_path; 823 int min_inflight = INT_MAX; 824 int inflight; 825 826 list_for_each_entry_rcu(clt_path, &clt->paths_list, s.entry) { 827 if (READ_ONCE(clt_path->state) != RTRS_CLT_CONNECTED) 828 continue; 829 830 if (!list_empty(raw_cpu_ptr(clt_path->mp_skip_entry))) 831 continue; 832 833 inflight = atomic_read(&clt_path->stats->inflight); 834 835 if (inflight < min_inflight) { 836 min_inflight = inflight; 837 min_path = clt_path; 838 } 839 } 840 841 /* 842 * add the path to the skip list, so that next time we can get 843 * a different one 844 */ 845 if (min_path) 846 list_add(raw_cpu_ptr(min_path->mp_skip_entry), &it->skip_list); 847 848 return min_path; 849 } 850 851 /** 852 * get_next_path_min_latency() - Returns path with minimal latency. 853 * @it: the path pointer 854 * 855 * Return: a path with the lowest latency or NULL if all paths are tried 856 * 857 * Locks: 858 * rcu_read_lock() must be hold. 859 * 860 * Related to @MP_POLICY_MIN_LATENCY 861 * 862 * This DOES skip an already-tried path. 863 * There is a skip-list to skip a path if the path has tried but failed. 864 * It will try the minimum latency path and then the second minimum latency 865 * path and so on. Finally it will return NULL if all paths are tried. 866 * Therefore the caller MUST check the returned 867 * path is NULL and trigger the IO error. 868 */ 869 static struct rtrs_clt_path *get_next_path_min_latency(struct path_it *it) 870 { 871 struct rtrs_clt_path *min_path = NULL; 872 struct rtrs_clt_sess *clt = it->clt; 873 struct rtrs_clt_path *clt_path; 874 ktime_t min_latency = KTIME_MAX; 875 ktime_t latency; 876 877 list_for_each_entry_rcu(clt_path, &clt->paths_list, s.entry) { 878 if (READ_ONCE(clt_path->state) != RTRS_CLT_CONNECTED) 879 continue; 880 881 if (!list_empty(raw_cpu_ptr(clt_path->mp_skip_entry))) 882 continue; 883 884 latency = clt_path->s.hb_cur_latency; 885 886 if (latency < min_latency) { 887 min_latency = latency; 888 min_path = clt_path; 889 } 890 } 891 892 /* 893 * add the path to the skip list, so that next time we can get 894 * a different one 895 */ 896 if (min_path) 897 list_add(raw_cpu_ptr(min_path->mp_skip_entry), &it->skip_list); 898 899 return min_path; 900 } 901 902 static inline void path_it_init(struct path_it *it, struct rtrs_clt_sess *clt) 903 { 904 INIT_LIST_HEAD(&it->skip_list); 905 it->clt = clt; 906 it->i = 0; 907 908 if (clt->mp_policy == MP_POLICY_RR) 909 it->next_path = get_next_path_rr; 910 else if (clt->mp_policy == MP_POLICY_MIN_INFLIGHT) 911 it->next_path = get_next_path_min_inflight; 912 else 913 it->next_path = get_next_path_min_latency; 914 } 915 916 static inline void path_it_deinit(struct path_it *it) 917 { 918 struct list_head *skip, *tmp; 919 /* 920 * The skip_list is used only for the MIN_INFLIGHT policy. 921 * We need to remove paths from it, so that next IO can insert 922 * paths (->mp_skip_entry) into a skip_list again. 923 */ 924 list_for_each_safe(skip, tmp, &it->skip_list) 925 list_del_init(skip); 926 } 927 928 /** 929 * rtrs_clt_init_req() - Initialize an rtrs_clt_io_req holding information 930 * about an inflight IO. 931 * The user buffer holding user control message (not data) is copied into 932 * the corresponding buffer of rtrs_iu (req->iu->buf), which later on will 933 * also hold the control message of rtrs. 934 * @req: an io request holding information about IO. 935 * @clt_path: client path 936 * @conf: conformation callback function to notify upper layer. 937 * @permit: permit for allocation of RDMA remote buffer 938 * @priv: private pointer 939 * @vec: kernel vector containing control message 940 * @usr_len: length of the user message 941 * @sg: scater list for IO data 942 * @sg_cnt: number of scater list entries 943 * @data_len: length of the IO data 944 * @dir: direction of the IO. 945 */ 946 static void rtrs_clt_init_req(struct rtrs_clt_io_req *req, 947 struct rtrs_clt_path *clt_path, 948 void (*conf)(void *priv, int errno), 949 struct rtrs_permit *permit, void *priv, 950 const struct kvec *vec, size_t usr_len, 951 struct scatterlist *sg, size_t sg_cnt, 952 size_t data_len, int dir) 953 { 954 struct iov_iter iter; 955 size_t len; 956 957 req->permit = permit; 958 req->in_use = true; 959 req->usr_len = usr_len; 960 req->data_len = data_len; 961 req->sglist = sg; 962 req->sg_cnt = sg_cnt; 963 req->priv = priv; 964 req->dir = dir; 965 req->con = rtrs_permit_to_clt_con(clt_path, permit); 966 req->conf = conf; 967 req->need_inv = false; 968 req->need_inv_comp = false; 969 req->inv_errno = 0; 970 refcount_set(&req->ref, 1); 971 req->mp_policy = clt_path->clt->mp_policy; 972 973 iov_iter_kvec(&iter, READ, vec, 1, usr_len); 974 len = _copy_from_iter(req->iu->buf, usr_len, &iter); 975 WARN_ON(len != usr_len); 976 977 reinit_completion(&req->inv_comp); 978 } 979 980 static struct rtrs_clt_io_req * 981 rtrs_clt_get_req(struct rtrs_clt_path *clt_path, 982 void (*conf)(void *priv, int errno), 983 struct rtrs_permit *permit, void *priv, 984 const struct kvec *vec, size_t usr_len, 985 struct scatterlist *sg, size_t sg_cnt, 986 size_t data_len, int dir) 987 { 988 struct rtrs_clt_io_req *req; 989 990 req = &clt_path->reqs[permit->mem_id]; 991 rtrs_clt_init_req(req, clt_path, conf, permit, priv, vec, usr_len, 992 sg, sg_cnt, data_len, dir); 993 return req; 994 } 995 996 static struct rtrs_clt_io_req * 997 rtrs_clt_get_copy_req(struct rtrs_clt_path *alive_path, 998 struct rtrs_clt_io_req *fail_req) 999 { 1000 struct rtrs_clt_io_req *req; 1001 struct kvec vec = { 1002 .iov_base = fail_req->iu->buf, 1003 .iov_len = fail_req->usr_len 1004 }; 1005 1006 req = &alive_path->reqs[fail_req->permit->mem_id]; 1007 rtrs_clt_init_req(req, alive_path, fail_req->conf, fail_req->permit, 1008 fail_req->priv, &vec, fail_req->usr_len, 1009 fail_req->sglist, fail_req->sg_cnt, 1010 fail_req->data_len, fail_req->dir); 1011 return req; 1012 } 1013 1014 static int rtrs_post_rdma_write_sg(struct rtrs_clt_con *con, 1015 struct rtrs_clt_io_req *req, 1016 struct rtrs_rbuf *rbuf, bool fr_en, 1017 u32 size, u32 imm, struct ib_send_wr *wr, 1018 struct ib_send_wr *tail) 1019 { 1020 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path); 1021 struct ib_sge *sge = req->sge; 1022 enum ib_send_flags flags; 1023 struct scatterlist *sg; 1024 size_t num_sge; 1025 int i; 1026 struct ib_send_wr *ptail = NULL; 1027 1028 if (fr_en) { 1029 i = 0; 1030 sge[i].addr = req->mr->iova; 1031 sge[i].length = req->mr->length; 1032 sge[i].lkey = req->mr->lkey; 1033 i++; 1034 num_sge = 2; 1035 ptail = tail; 1036 } else { 1037 for_each_sg(req->sglist, sg, req->sg_cnt, i) { 1038 sge[i].addr = sg_dma_address(sg); 1039 sge[i].length = sg_dma_len(sg); 1040 sge[i].lkey = clt_path->s.dev->ib_pd->local_dma_lkey; 1041 } 1042 num_sge = 1 + req->sg_cnt; 1043 } 1044 sge[i].addr = req->iu->dma_addr; 1045 sge[i].length = size; 1046 sge[i].lkey = clt_path->s.dev->ib_pd->local_dma_lkey; 1047 1048 /* 1049 * From time to time we have to post signalled sends, 1050 * or send queue will fill up and only QP reset can help. 1051 */ 1052 flags = atomic_inc_return(&con->c.wr_cnt) % clt_path->s.signal_interval ? 1053 0 : IB_SEND_SIGNALED; 1054 1055 ib_dma_sync_single_for_device(clt_path->s.dev->ib_dev, 1056 req->iu->dma_addr, 1057 size, DMA_TO_DEVICE); 1058 1059 return rtrs_iu_post_rdma_write_imm(&con->c, req->iu, sge, num_sge, 1060 rbuf->rkey, rbuf->addr, imm, 1061 flags, wr, ptail); 1062 } 1063 1064 static int rtrs_map_sg_fr(struct rtrs_clt_io_req *req, size_t count) 1065 { 1066 int nr; 1067 1068 /* Align the MR to a 4K page size to match the block virt boundary */ 1069 nr = ib_map_mr_sg(req->mr, req->sglist, count, NULL, SZ_4K); 1070 if (nr < 0) 1071 return nr; 1072 if (nr < req->sg_cnt) 1073 return -EINVAL; 1074 ib_update_fast_reg_key(req->mr, ib_inc_rkey(req->mr->rkey)); 1075 1076 return nr; 1077 } 1078 1079 static int rtrs_clt_write_req(struct rtrs_clt_io_req *req) 1080 { 1081 struct rtrs_clt_con *con = req->con; 1082 struct rtrs_path *s = con->c.path; 1083 struct rtrs_clt_path *clt_path = to_clt_path(s); 1084 struct rtrs_msg_rdma_write *msg; 1085 1086 struct rtrs_rbuf *rbuf; 1087 int ret, count = 0; 1088 u32 imm, buf_id; 1089 struct ib_reg_wr rwr; 1090 struct ib_send_wr inv_wr; 1091 struct ib_send_wr *wr = NULL; 1092 bool fr_en = false; 1093 1094 const size_t tsize = sizeof(*msg) + req->data_len + req->usr_len; 1095 1096 if (tsize > clt_path->chunk_size) { 1097 rtrs_wrn(s, "Write request failed, size too big %zu > %d\n", 1098 tsize, clt_path->chunk_size); 1099 return -EMSGSIZE; 1100 } 1101 if (req->sg_cnt) { 1102 count = ib_dma_map_sg(clt_path->s.dev->ib_dev, req->sglist, 1103 req->sg_cnt, req->dir); 1104 if (!count) { 1105 rtrs_wrn(s, "Write request failed, map failed\n"); 1106 return -EINVAL; 1107 } 1108 } 1109 /* put rtrs msg after sg and user message */ 1110 msg = req->iu->buf + req->usr_len; 1111 msg->type = cpu_to_le16(RTRS_MSG_WRITE); 1112 msg->usr_len = cpu_to_le16(req->usr_len); 1113 1114 /* rtrs message on server side will be after user data and message */ 1115 imm = req->permit->mem_off + req->data_len + req->usr_len; 1116 imm = rtrs_to_io_req_imm(imm); 1117 buf_id = req->permit->mem_id; 1118 req->sg_size = tsize; 1119 rbuf = &clt_path->rbufs[buf_id]; 1120 1121 if (count) { 1122 ret = rtrs_map_sg_fr(req, count); 1123 if (ret < 0) { 1124 rtrs_err_rl(s, 1125 "Write request failed, failed to map fast reg. data, err: %d\n", 1126 ret); 1127 ib_dma_unmap_sg(clt_path->s.dev->ib_dev, req->sglist, 1128 req->sg_cnt, req->dir); 1129 return ret; 1130 } 1131 inv_wr = (struct ib_send_wr) { 1132 .opcode = IB_WR_LOCAL_INV, 1133 .wr_cqe = &req->inv_cqe, 1134 .send_flags = IB_SEND_SIGNALED, 1135 .ex.invalidate_rkey = req->mr->rkey, 1136 }; 1137 req->inv_cqe.done = rtrs_clt_inv_rkey_done; 1138 rwr = (struct ib_reg_wr) { 1139 .wr.opcode = IB_WR_REG_MR, 1140 .wr.wr_cqe = &fast_reg_cqe, 1141 .mr = req->mr, 1142 .key = req->mr->rkey, 1143 .access = (IB_ACCESS_LOCAL_WRITE), 1144 }; 1145 wr = &rwr.wr; 1146 fr_en = true; 1147 refcount_inc(&req->ref); 1148 } 1149 /* 1150 * Update stats now, after request is successfully sent it is not 1151 * safe anymore to touch it. 1152 */ 1153 rtrs_clt_update_all_stats(req, WRITE); 1154 1155 ret = rtrs_post_rdma_write_sg(req->con, req, rbuf, fr_en, 1156 req->usr_len + sizeof(*msg), 1157 imm, wr, &inv_wr); 1158 if (ret) { 1159 rtrs_err_rl(s, 1160 "Write request failed: error=%d path=%s [%s:%u]\n", 1161 ret, kobject_name(&clt_path->kobj), clt_path->hca_name, 1162 clt_path->hca_port); 1163 if (req->mp_policy == MP_POLICY_MIN_INFLIGHT) 1164 atomic_dec(&clt_path->stats->inflight); 1165 if (req->sg_cnt) 1166 ib_dma_unmap_sg(clt_path->s.dev->ib_dev, req->sglist, 1167 req->sg_cnt, req->dir); 1168 } 1169 1170 return ret; 1171 } 1172 1173 static int rtrs_clt_read_req(struct rtrs_clt_io_req *req) 1174 { 1175 struct rtrs_clt_con *con = req->con; 1176 struct rtrs_path *s = con->c.path; 1177 struct rtrs_clt_path *clt_path = to_clt_path(s); 1178 struct rtrs_msg_rdma_read *msg; 1179 struct rtrs_ib_dev *dev = clt_path->s.dev; 1180 1181 struct ib_reg_wr rwr; 1182 struct ib_send_wr *wr = NULL; 1183 1184 int ret, count = 0; 1185 u32 imm, buf_id; 1186 1187 const size_t tsize = sizeof(*msg) + req->data_len + req->usr_len; 1188 1189 if (tsize > clt_path->chunk_size) { 1190 rtrs_wrn(s, 1191 "Read request failed, message size is %zu, bigger than CHUNK_SIZE %d\n", 1192 tsize, clt_path->chunk_size); 1193 return -EMSGSIZE; 1194 } 1195 1196 if (req->sg_cnt) { 1197 count = ib_dma_map_sg(dev->ib_dev, req->sglist, req->sg_cnt, 1198 req->dir); 1199 if (!count) { 1200 rtrs_wrn(s, 1201 "Read request failed, dma map failed\n"); 1202 return -EINVAL; 1203 } 1204 } 1205 /* put our message into req->buf after user message*/ 1206 msg = req->iu->buf + req->usr_len; 1207 msg->type = cpu_to_le16(RTRS_MSG_READ); 1208 msg->usr_len = cpu_to_le16(req->usr_len); 1209 1210 if (count) { 1211 ret = rtrs_map_sg_fr(req, count); 1212 if (ret < 0) { 1213 rtrs_err_rl(s, 1214 "Read request failed, failed to map fast reg. data, err: %d\n", 1215 ret); 1216 ib_dma_unmap_sg(dev->ib_dev, req->sglist, req->sg_cnt, 1217 req->dir); 1218 return ret; 1219 } 1220 rwr = (struct ib_reg_wr) { 1221 .wr.opcode = IB_WR_REG_MR, 1222 .wr.wr_cqe = &fast_reg_cqe, 1223 .mr = req->mr, 1224 .key = req->mr->rkey, 1225 .access = (IB_ACCESS_LOCAL_WRITE | 1226 IB_ACCESS_REMOTE_WRITE), 1227 }; 1228 wr = &rwr.wr; 1229 1230 msg->sg_cnt = cpu_to_le16(1); 1231 msg->flags = cpu_to_le16(RTRS_MSG_NEED_INVAL_F); 1232 1233 msg->desc[0].addr = cpu_to_le64(req->mr->iova); 1234 msg->desc[0].key = cpu_to_le32(req->mr->rkey); 1235 msg->desc[0].len = cpu_to_le32(req->mr->length); 1236 1237 /* Further invalidation is required */ 1238 req->need_inv = !!RTRS_MSG_NEED_INVAL_F; 1239 1240 } else { 1241 msg->sg_cnt = 0; 1242 msg->flags = 0; 1243 } 1244 /* 1245 * rtrs message will be after the space reserved for disk data and 1246 * user message 1247 */ 1248 imm = req->permit->mem_off + req->data_len + req->usr_len; 1249 imm = rtrs_to_io_req_imm(imm); 1250 buf_id = req->permit->mem_id; 1251 1252 req->sg_size = sizeof(*msg); 1253 req->sg_size += le16_to_cpu(msg->sg_cnt) * sizeof(struct rtrs_sg_desc); 1254 req->sg_size += req->usr_len; 1255 1256 /* 1257 * Update stats now, after request is successfully sent it is not 1258 * safe anymore to touch it. 1259 */ 1260 rtrs_clt_update_all_stats(req, READ); 1261 1262 ret = rtrs_post_send_rdma(req->con, req, &clt_path->rbufs[buf_id], 1263 req->data_len, imm, wr); 1264 if (ret) { 1265 rtrs_err_rl(s, 1266 "Read request failed: error=%d path=%s [%s:%u]\n", 1267 ret, kobject_name(&clt_path->kobj), clt_path->hca_name, 1268 clt_path->hca_port); 1269 if (req->mp_policy == MP_POLICY_MIN_INFLIGHT) 1270 atomic_dec(&clt_path->stats->inflight); 1271 req->need_inv = false; 1272 if (req->sg_cnt) 1273 ib_dma_unmap_sg(dev->ib_dev, req->sglist, 1274 req->sg_cnt, req->dir); 1275 } 1276 1277 return ret; 1278 } 1279 1280 /** 1281 * rtrs_clt_failover_req() - Try to find an active path for a failed request 1282 * @clt: clt context 1283 * @fail_req: a failed io request. 1284 */ 1285 static int rtrs_clt_failover_req(struct rtrs_clt_sess *clt, 1286 struct rtrs_clt_io_req *fail_req) 1287 { 1288 struct rtrs_clt_path *alive_path; 1289 struct rtrs_clt_io_req *req; 1290 int err = -ECONNABORTED; 1291 struct path_it it; 1292 1293 rcu_read_lock(); 1294 for (path_it_init(&it, clt); 1295 (alive_path = it.next_path(&it)) && it.i < it.clt->paths_num; 1296 it.i++) { 1297 if (READ_ONCE(alive_path->state) != RTRS_CLT_CONNECTED) 1298 continue; 1299 req = rtrs_clt_get_copy_req(alive_path, fail_req); 1300 if (req->dir == DMA_TO_DEVICE) 1301 err = rtrs_clt_write_req(req); 1302 else 1303 err = rtrs_clt_read_req(req); 1304 if (err) { 1305 req->in_use = false; 1306 continue; 1307 } 1308 /* Success path */ 1309 rtrs_clt_inc_failover_cnt(alive_path->stats); 1310 break; 1311 } 1312 path_it_deinit(&it); 1313 rcu_read_unlock(); 1314 1315 return err; 1316 } 1317 1318 static void fail_all_outstanding_reqs(struct rtrs_clt_path *clt_path) 1319 { 1320 struct rtrs_clt_sess *clt = clt_path->clt; 1321 struct rtrs_clt_io_req *req; 1322 int i, err; 1323 1324 if (!clt_path->reqs) 1325 return; 1326 for (i = 0; i < clt_path->queue_depth; ++i) { 1327 req = &clt_path->reqs[i]; 1328 if (!req->in_use) 1329 continue; 1330 1331 /* 1332 * Safely (without notification) complete failed request. 1333 * After completion this request is still useble and can 1334 * be failovered to another path. 1335 */ 1336 complete_rdma_req(req, -ECONNABORTED, false, true); 1337 1338 err = rtrs_clt_failover_req(clt, req); 1339 if (err) 1340 /* Failover failed, notify anyway */ 1341 req->conf(req->priv, err); 1342 } 1343 } 1344 1345 static void free_path_reqs(struct rtrs_clt_path *clt_path) 1346 { 1347 struct rtrs_clt_io_req *req; 1348 int i; 1349 1350 if (!clt_path->reqs) 1351 return; 1352 for (i = 0; i < clt_path->queue_depth; ++i) { 1353 req = &clt_path->reqs[i]; 1354 if (req->mr) 1355 ib_dereg_mr(req->mr); 1356 kfree(req->sge); 1357 rtrs_iu_free(req->iu, clt_path->s.dev->ib_dev, 1); 1358 } 1359 kfree(clt_path->reqs); 1360 clt_path->reqs = NULL; 1361 } 1362 1363 static int alloc_path_reqs(struct rtrs_clt_path *clt_path) 1364 { 1365 struct rtrs_clt_io_req *req; 1366 int i, err = -ENOMEM; 1367 1368 clt_path->reqs = kcalloc(clt_path->queue_depth, 1369 sizeof(*clt_path->reqs), 1370 GFP_KERNEL); 1371 if (!clt_path->reqs) 1372 return -ENOMEM; 1373 1374 for (i = 0; i < clt_path->queue_depth; ++i) { 1375 req = &clt_path->reqs[i]; 1376 req->iu = rtrs_iu_alloc(1, clt_path->max_hdr_size, GFP_KERNEL, 1377 clt_path->s.dev->ib_dev, 1378 DMA_TO_DEVICE, 1379 rtrs_clt_rdma_done); 1380 if (!req->iu) 1381 goto out; 1382 1383 req->sge = kcalloc(2, sizeof(*req->sge), GFP_KERNEL); 1384 if (!req->sge) 1385 goto out; 1386 1387 req->mr = ib_alloc_mr(clt_path->s.dev->ib_pd, 1388 IB_MR_TYPE_MEM_REG, 1389 clt_path->max_pages_per_mr); 1390 if (IS_ERR(req->mr)) { 1391 err = PTR_ERR(req->mr); 1392 req->mr = NULL; 1393 pr_err("Failed to alloc clt_path->max_pages_per_mr %d\n", 1394 clt_path->max_pages_per_mr); 1395 goto out; 1396 } 1397 1398 init_completion(&req->inv_comp); 1399 } 1400 1401 return 0; 1402 1403 out: 1404 free_path_reqs(clt_path); 1405 1406 return err; 1407 } 1408 1409 static int alloc_permits(struct rtrs_clt_sess *clt) 1410 { 1411 unsigned int chunk_bits; 1412 int err, i; 1413 1414 clt->permits_map = kcalloc(BITS_TO_LONGS(clt->queue_depth), 1415 sizeof(long), GFP_KERNEL); 1416 if (!clt->permits_map) { 1417 err = -ENOMEM; 1418 goto out_err; 1419 } 1420 clt->permits = kcalloc(clt->queue_depth, permit_size(clt), GFP_KERNEL); 1421 if (!clt->permits) { 1422 err = -ENOMEM; 1423 goto err_map; 1424 } 1425 chunk_bits = ilog2(clt->queue_depth - 1) + 1; 1426 for (i = 0; i < clt->queue_depth; i++) { 1427 struct rtrs_permit *permit; 1428 1429 permit = get_permit(clt, i); 1430 permit->mem_id = i; 1431 permit->mem_off = i << (MAX_IMM_PAYL_BITS - chunk_bits); 1432 } 1433 1434 return 0; 1435 1436 err_map: 1437 kfree(clt->permits_map); 1438 clt->permits_map = NULL; 1439 out_err: 1440 return err; 1441 } 1442 1443 static void free_permits(struct rtrs_clt_sess *clt) 1444 { 1445 if (clt->permits_map) { 1446 size_t sz = clt->queue_depth; 1447 1448 wait_event(clt->permits_wait, 1449 find_first_bit(clt->permits_map, sz) >= sz); 1450 } 1451 kfree(clt->permits_map); 1452 clt->permits_map = NULL; 1453 kfree(clt->permits); 1454 clt->permits = NULL; 1455 } 1456 1457 static void query_fast_reg_mode(struct rtrs_clt_path *clt_path) 1458 { 1459 struct ib_device *ib_dev; 1460 u64 max_pages_per_mr; 1461 int mr_page_shift; 1462 1463 ib_dev = clt_path->s.dev->ib_dev; 1464 1465 /* 1466 * Use the smallest page size supported by the HCA, down to a 1467 * minimum of 4096 bytes. We're unlikely to build large sglists 1468 * out of smaller entries. 1469 */ 1470 mr_page_shift = max(12, ffs(ib_dev->attrs.page_size_cap) - 1); 1471 max_pages_per_mr = ib_dev->attrs.max_mr_size; 1472 do_div(max_pages_per_mr, (1ull << mr_page_shift)); 1473 clt_path->max_pages_per_mr = 1474 min3(clt_path->max_pages_per_mr, (u32)max_pages_per_mr, 1475 ib_dev->attrs.max_fast_reg_page_list_len); 1476 clt_path->clt->max_segments = 1477 min(clt_path->max_pages_per_mr, clt_path->clt->max_segments); 1478 } 1479 1480 static bool rtrs_clt_change_state_get_old(struct rtrs_clt_path *clt_path, 1481 enum rtrs_clt_state new_state, 1482 enum rtrs_clt_state *old_state) 1483 { 1484 bool changed; 1485 1486 spin_lock_irq(&clt_path->state_wq.lock); 1487 if (old_state) 1488 *old_state = clt_path->state; 1489 changed = rtrs_clt_change_state(clt_path, new_state); 1490 spin_unlock_irq(&clt_path->state_wq.lock); 1491 1492 return changed; 1493 } 1494 1495 static void rtrs_clt_hb_err_handler(struct rtrs_con *c) 1496 { 1497 struct rtrs_clt_con *con = container_of(c, typeof(*con), c); 1498 1499 rtrs_rdma_error_recovery(con); 1500 } 1501 1502 static void rtrs_clt_init_hb(struct rtrs_clt_path *clt_path) 1503 { 1504 rtrs_init_hb(&clt_path->s, &io_comp_cqe, 1505 RTRS_HB_INTERVAL_MS, 1506 RTRS_HB_MISSED_MAX, 1507 rtrs_clt_hb_err_handler, 1508 rtrs_wq); 1509 } 1510 1511 static void rtrs_clt_reconnect_work(struct work_struct *work); 1512 static void rtrs_clt_close_work(struct work_struct *work); 1513 1514 static struct rtrs_clt_path *alloc_path(struct rtrs_clt_sess *clt, 1515 const struct rtrs_addr *path, 1516 size_t con_num, u32 nr_poll_queues) 1517 { 1518 struct rtrs_clt_path *clt_path; 1519 int err = -ENOMEM; 1520 int cpu; 1521 size_t total_con; 1522 1523 clt_path = kzalloc(sizeof(*clt_path), GFP_KERNEL); 1524 if (!clt_path) 1525 goto err; 1526 1527 /* 1528 * irqmode and poll 1529 * +1: Extra connection for user messages 1530 */ 1531 total_con = con_num + nr_poll_queues + 1; 1532 clt_path->s.con = kcalloc(total_con, sizeof(*clt_path->s.con), 1533 GFP_KERNEL); 1534 if (!clt_path->s.con) 1535 goto err_free_path; 1536 1537 clt_path->s.con_num = total_con; 1538 clt_path->s.irq_con_num = con_num + 1; 1539 1540 clt_path->stats = kzalloc(sizeof(*clt_path->stats), GFP_KERNEL); 1541 if (!clt_path->stats) 1542 goto err_free_con; 1543 1544 mutex_init(&clt_path->init_mutex); 1545 uuid_gen(&clt_path->s.uuid); 1546 memcpy(&clt_path->s.dst_addr, path->dst, 1547 rdma_addr_size((struct sockaddr *)path->dst)); 1548 1549 /* 1550 * rdma_resolve_addr() passes src_addr to cma_bind_addr, which 1551 * checks the sa_family to be non-zero. If user passed src_addr=NULL 1552 * the sess->src_addr will contain only zeros, which is then fine. 1553 */ 1554 if (path->src) 1555 memcpy(&clt_path->s.src_addr, path->src, 1556 rdma_addr_size((struct sockaddr *)path->src)); 1557 strscpy(clt_path->s.sessname, clt->sessname, 1558 sizeof(clt_path->s.sessname)); 1559 clt_path->clt = clt; 1560 clt_path->max_pages_per_mr = RTRS_MAX_SEGMENTS; 1561 init_waitqueue_head(&clt_path->state_wq); 1562 clt_path->state = RTRS_CLT_CONNECTING; 1563 atomic_set(&clt_path->connected_cnt, 0); 1564 INIT_WORK(&clt_path->close_work, rtrs_clt_close_work); 1565 INIT_DELAYED_WORK(&clt_path->reconnect_dwork, rtrs_clt_reconnect_work); 1566 rtrs_clt_init_hb(clt_path); 1567 1568 clt_path->mp_skip_entry = alloc_percpu(typeof(*clt_path->mp_skip_entry)); 1569 if (!clt_path->mp_skip_entry) 1570 goto err_free_stats; 1571 1572 for_each_possible_cpu(cpu) 1573 INIT_LIST_HEAD(per_cpu_ptr(clt_path->mp_skip_entry, cpu)); 1574 1575 err = rtrs_clt_init_stats(clt_path->stats); 1576 if (err) 1577 goto err_free_percpu; 1578 1579 return clt_path; 1580 1581 err_free_percpu: 1582 free_percpu(clt_path->mp_skip_entry); 1583 err_free_stats: 1584 kfree(clt_path->stats); 1585 err_free_con: 1586 kfree(clt_path->s.con); 1587 err_free_path: 1588 kfree(clt_path); 1589 err: 1590 return ERR_PTR(err); 1591 } 1592 1593 void free_path(struct rtrs_clt_path *clt_path) 1594 { 1595 free_percpu(clt_path->mp_skip_entry); 1596 mutex_destroy(&clt_path->init_mutex); 1597 kfree(clt_path->s.con); 1598 kfree(clt_path->rbufs); 1599 kfree(clt_path); 1600 } 1601 1602 static int create_con(struct rtrs_clt_path *clt_path, unsigned int cid) 1603 { 1604 struct rtrs_clt_con *con; 1605 1606 con = kzalloc(sizeof(*con), GFP_KERNEL); 1607 if (!con) 1608 return -ENOMEM; 1609 1610 /* Map first two connections to the first CPU */ 1611 con->cpu = (cid ? cid - 1 : 0) % nr_cpu_ids; 1612 con->c.cid = cid; 1613 con->c.path = &clt_path->s; 1614 /* Align with srv, init as 1 */ 1615 atomic_set(&con->c.wr_cnt, 1); 1616 mutex_init(&con->con_mutex); 1617 1618 clt_path->s.con[cid] = &con->c; 1619 1620 return 0; 1621 } 1622 1623 static void destroy_con(struct rtrs_clt_con *con) 1624 { 1625 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path); 1626 1627 clt_path->s.con[con->c.cid] = NULL; 1628 mutex_destroy(&con->con_mutex); 1629 kfree(con); 1630 } 1631 1632 static int create_con_cq_qp(struct rtrs_clt_con *con) 1633 { 1634 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path); 1635 u32 max_send_wr, max_recv_wr, cq_num, max_send_sge, wr_limit; 1636 int err, cq_vector; 1637 struct rtrs_msg_rkey_rsp *rsp; 1638 1639 lockdep_assert_held(&con->con_mutex); 1640 if (con->c.cid == 0) { 1641 max_send_sge = 1; 1642 /* We must be the first here */ 1643 if (WARN_ON(clt_path->s.dev)) 1644 return -EINVAL; 1645 1646 /* 1647 * The whole session uses device from user connection. 1648 * Be careful not to close user connection before ib dev 1649 * is gracefully put. 1650 */ 1651 clt_path->s.dev = rtrs_ib_dev_find_or_add(con->c.cm_id->device, 1652 &dev_pd); 1653 if (!clt_path->s.dev) { 1654 rtrs_wrn(clt_path->clt, 1655 "rtrs_ib_dev_find_get_or_add(): no memory\n"); 1656 return -ENOMEM; 1657 } 1658 clt_path->s.dev_ref = 1; 1659 query_fast_reg_mode(clt_path); 1660 wr_limit = clt_path->s.dev->ib_dev->attrs.max_qp_wr; 1661 /* 1662 * Two (request + registration) completion for send 1663 * Two for recv if always_invalidate is set on server 1664 * or one for recv. 1665 * + 2 for drain and heartbeat 1666 * in case qp gets into error state. 1667 */ 1668 max_send_wr = 1669 min_t(int, wr_limit, SERVICE_CON_QUEUE_DEPTH * 2 + 2); 1670 max_recv_wr = max_send_wr; 1671 } else { 1672 /* 1673 * Here we assume that session members are correctly set. 1674 * This is always true if user connection (cid == 0) is 1675 * established first. 1676 */ 1677 if (WARN_ON(!clt_path->s.dev)) 1678 return -EINVAL; 1679 if (WARN_ON(!clt_path->queue_depth)) 1680 return -EINVAL; 1681 1682 wr_limit = clt_path->s.dev->ib_dev->attrs.max_qp_wr; 1683 /* Shared between connections */ 1684 clt_path->s.dev_ref++; 1685 max_send_wr = min_t(int, wr_limit, 1686 /* QD * (REQ + RSP + FR REGS or INVS) + drain */ 1687 clt_path->queue_depth * 3 + 1); 1688 max_recv_wr = min_t(int, wr_limit, 1689 clt_path->queue_depth * 3 + 1); 1690 max_send_sge = 2; 1691 } 1692 atomic_set(&con->c.sq_wr_avail, max_send_wr); 1693 cq_num = max_send_wr + max_recv_wr; 1694 /* alloc iu to recv new rkey reply when server reports flags set */ 1695 if (clt_path->flags & RTRS_MSG_NEW_RKEY_F || con->c.cid == 0) { 1696 con->rsp_ius = rtrs_iu_alloc(cq_num, sizeof(*rsp), 1697 GFP_KERNEL, 1698 clt_path->s.dev->ib_dev, 1699 DMA_FROM_DEVICE, 1700 rtrs_clt_rdma_done); 1701 if (!con->rsp_ius) 1702 return -ENOMEM; 1703 con->queue_num = cq_num; 1704 } 1705 cq_num = max_send_wr + max_recv_wr; 1706 cq_vector = con->cpu % clt_path->s.dev->ib_dev->num_comp_vectors; 1707 if (con->c.cid >= clt_path->s.irq_con_num) 1708 err = rtrs_cq_qp_create(&clt_path->s, &con->c, max_send_sge, 1709 cq_vector, cq_num, max_send_wr, 1710 max_recv_wr, IB_POLL_DIRECT); 1711 else 1712 err = rtrs_cq_qp_create(&clt_path->s, &con->c, max_send_sge, 1713 cq_vector, cq_num, max_send_wr, 1714 max_recv_wr, IB_POLL_SOFTIRQ); 1715 /* 1716 * In case of error we do not bother to clean previous allocations, 1717 * since destroy_con_cq_qp() must be called. 1718 */ 1719 return err; 1720 } 1721 1722 static void destroy_con_cq_qp(struct rtrs_clt_con *con) 1723 { 1724 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path); 1725 1726 /* 1727 * Be careful here: destroy_con_cq_qp() can be called even 1728 * create_con_cq_qp() failed, see comments there. 1729 */ 1730 lockdep_assert_held(&con->con_mutex); 1731 rtrs_cq_qp_destroy(&con->c); 1732 if (con->rsp_ius) { 1733 rtrs_iu_free(con->rsp_ius, clt_path->s.dev->ib_dev, 1734 con->queue_num); 1735 con->rsp_ius = NULL; 1736 con->queue_num = 0; 1737 } 1738 if (clt_path->s.dev_ref && !--clt_path->s.dev_ref) { 1739 rtrs_ib_dev_put(clt_path->s.dev); 1740 clt_path->s.dev = NULL; 1741 } 1742 } 1743 1744 static void stop_cm(struct rtrs_clt_con *con) 1745 { 1746 rdma_disconnect(con->c.cm_id); 1747 if (con->c.qp) 1748 ib_drain_qp(con->c.qp); 1749 } 1750 1751 static void destroy_cm(struct rtrs_clt_con *con) 1752 { 1753 rdma_destroy_id(con->c.cm_id); 1754 con->c.cm_id = NULL; 1755 } 1756 1757 static int rtrs_rdma_addr_resolved(struct rtrs_clt_con *con) 1758 { 1759 struct rtrs_path *s = con->c.path; 1760 int err; 1761 1762 mutex_lock(&con->con_mutex); 1763 err = create_con_cq_qp(con); 1764 mutex_unlock(&con->con_mutex); 1765 if (err) { 1766 rtrs_err(s, "create_con_cq_qp(), err: %d\n", err); 1767 return err; 1768 } 1769 err = rdma_resolve_route(con->c.cm_id, RTRS_CONNECT_TIMEOUT_MS); 1770 if (err) 1771 rtrs_err(s, "Resolving route failed, err: %d\n", err); 1772 1773 return err; 1774 } 1775 1776 static int rtrs_rdma_route_resolved(struct rtrs_clt_con *con) 1777 { 1778 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path); 1779 struct rtrs_clt_sess *clt = clt_path->clt; 1780 struct rtrs_msg_conn_req msg; 1781 struct rdma_conn_param param; 1782 1783 int err; 1784 1785 param = (struct rdma_conn_param) { 1786 .retry_count = 7, 1787 .rnr_retry_count = 7, 1788 .private_data = &msg, 1789 .private_data_len = sizeof(msg), 1790 }; 1791 1792 msg = (struct rtrs_msg_conn_req) { 1793 .magic = cpu_to_le16(RTRS_MAGIC), 1794 .version = cpu_to_le16(RTRS_PROTO_VER), 1795 .cid = cpu_to_le16(con->c.cid), 1796 .cid_num = cpu_to_le16(clt_path->s.con_num), 1797 .recon_cnt = cpu_to_le16(clt_path->s.recon_cnt), 1798 }; 1799 msg.first_conn = clt_path->for_new_clt ? FIRST_CONN : 0; 1800 uuid_copy(&msg.sess_uuid, &clt_path->s.uuid); 1801 uuid_copy(&msg.paths_uuid, &clt->paths_uuid); 1802 1803 err = rdma_connect_locked(con->c.cm_id, ¶m); 1804 if (err) 1805 rtrs_err(clt, "rdma_connect_locked(): %d\n", err); 1806 1807 return err; 1808 } 1809 1810 static int rtrs_rdma_conn_established(struct rtrs_clt_con *con, 1811 struct rdma_cm_event *ev) 1812 { 1813 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path); 1814 struct rtrs_clt_sess *clt = clt_path->clt; 1815 const struct rtrs_msg_conn_rsp *msg; 1816 u16 version, queue_depth; 1817 int errno; 1818 u8 len; 1819 1820 msg = ev->param.conn.private_data; 1821 len = ev->param.conn.private_data_len; 1822 if (len < sizeof(*msg)) { 1823 rtrs_err(clt, "Invalid RTRS connection response\n"); 1824 return -ECONNRESET; 1825 } 1826 if (le16_to_cpu(msg->magic) != RTRS_MAGIC) { 1827 rtrs_err(clt, "Invalid RTRS magic\n"); 1828 return -ECONNRESET; 1829 } 1830 version = le16_to_cpu(msg->version); 1831 if (version >> 8 != RTRS_PROTO_VER_MAJOR) { 1832 rtrs_err(clt, "Unsupported major RTRS version: %d, expected %d\n", 1833 version >> 8, RTRS_PROTO_VER_MAJOR); 1834 return -ECONNRESET; 1835 } 1836 errno = le16_to_cpu(msg->errno); 1837 if (errno) { 1838 rtrs_err(clt, "Invalid RTRS message: errno %d\n", 1839 errno); 1840 return -ECONNRESET; 1841 } 1842 if (con->c.cid == 0) { 1843 queue_depth = le16_to_cpu(msg->queue_depth); 1844 1845 if (clt_path->queue_depth > 0 && queue_depth != clt_path->queue_depth) { 1846 rtrs_err(clt, "Error: queue depth changed\n"); 1847 1848 /* 1849 * Stop any more reconnection attempts 1850 */ 1851 clt_path->reconnect_attempts = -1; 1852 rtrs_err(clt, 1853 "Disabling auto-reconnect. Trigger a manual reconnect after issue is resolved\n"); 1854 return -ECONNRESET; 1855 } 1856 1857 if (!clt_path->rbufs) { 1858 clt_path->rbufs = kcalloc(queue_depth, 1859 sizeof(*clt_path->rbufs), 1860 GFP_KERNEL); 1861 if (!clt_path->rbufs) 1862 return -ENOMEM; 1863 } 1864 clt_path->queue_depth = queue_depth; 1865 clt_path->s.signal_interval = min_not_zero(queue_depth, 1866 (unsigned short) SERVICE_CON_QUEUE_DEPTH); 1867 clt_path->max_hdr_size = le32_to_cpu(msg->max_hdr_size); 1868 clt_path->max_io_size = le32_to_cpu(msg->max_io_size); 1869 clt_path->flags = le32_to_cpu(msg->flags); 1870 clt_path->chunk_size = clt_path->max_io_size + clt_path->max_hdr_size; 1871 1872 /* 1873 * Global IO size is always a minimum. 1874 * If while a reconnection server sends us a value a bit 1875 * higher - client does not care and uses cached minimum. 1876 * 1877 * Since we can have several sessions (paths) restablishing 1878 * connections in parallel, use lock. 1879 */ 1880 mutex_lock(&clt->paths_mutex); 1881 clt->queue_depth = clt_path->queue_depth; 1882 clt->max_io_size = min_not_zero(clt_path->max_io_size, 1883 clt->max_io_size); 1884 mutex_unlock(&clt->paths_mutex); 1885 1886 /* 1887 * Cache the hca_port and hca_name for sysfs 1888 */ 1889 clt_path->hca_port = con->c.cm_id->port_num; 1890 scnprintf(clt_path->hca_name, sizeof(clt_path->hca_name), 1891 clt_path->s.dev->ib_dev->name); 1892 clt_path->s.src_addr = con->c.cm_id->route.addr.src_addr; 1893 /* set for_new_clt, to allow future reconnect on any path */ 1894 clt_path->for_new_clt = 1; 1895 } 1896 1897 return 0; 1898 } 1899 1900 static inline void flag_success_on_conn(struct rtrs_clt_con *con) 1901 { 1902 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path); 1903 1904 atomic_inc(&clt_path->connected_cnt); 1905 con->cm_err = 1; 1906 } 1907 1908 static int rtrs_rdma_conn_rejected(struct rtrs_clt_con *con, 1909 struct rdma_cm_event *ev) 1910 { 1911 struct rtrs_path *s = con->c.path; 1912 const struct rtrs_msg_conn_rsp *msg; 1913 const char *rej_msg; 1914 int status, errno; 1915 u8 data_len; 1916 1917 status = ev->status; 1918 rej_msg = rdma_reject_msg(con->c.cm_id, status); 1919 msg = rdma_consumer_reject_data(con->c.cm_id, ev, &data_len); 1920 1921 if (msg && data_len >= sizeof(*msg)) { 1922 errno = (int16_t)le16_to_cpu(msg->errno); 1923 if (errno == -EBUSY) 1924 rtrs_err(s, 1925 "Previous session is still exists on the server, please reconnect later\n"); 1926 else 1927 rtrs_err(s, 1928 "Connect rejected: status %d (%s), rtrs errno %d\n", 1929 status, rej_msg, errno); 1930 } else { 1931 rtrs_err(s, 1932 "Connect rejected but with malformed message: status %d (%s)\n", 1933 status, rej_msg); 1934 } 1935 1936 return -ECONNRESET; 1937 } 1938 1939 void rtrs_clt_close_conns(struct rtrs_clt_path *clt_path, bool wait) 1940 { 1941 if (rtrs_clt_change_state_get_old(clt_path, RTRS_CLT_CLOSING, NULL)) 1942 queue_work(rtrs_wq, &clt_path->close_work); 1943 if (wait) 1944 flush_work(&clt_path->close_work); 1945 } 1946 1947 static inline void flag_error_on_conn(struct rtrs_clt_con *con, int cm_err) 1948 { 1949 if (con->cm_err == 1) { 1950 struct rtrs_clt_path *clt_path; 1951 1952 clt_path = to_clt_path(con->c.path); 1953 if (atomic_dec_and_test(&clt_path->connected_cnt)) 1954 1955 wake_up(&clt_path->state_wq); 1956 } 1957 con->cm_err = cm_err; 1958 } 1959 1960 static int rtrs_clt_rdma_cm_handler(struct rdma_cm_id *cm_id, 1961 struct rdma_cm_event *ev) 1962 { 1963 struct rtrs_clt_con *con = cm_id->context; 1964 struct rtrs_path *s = con->c.path; 1965 struct rtrs_clt_path *clt_path = to_clt_path(s); 1966 int cm_err = 0; 1967 1968 switch (ev->event) { 1969 case RDMA_CM_EVENT_ADDR_RESOLVED: 1970 cm_err = rtrs_rdma_addr_resolved(con); 1971 break; 1972 case RDMA_CM_EVENT_ROUTE_RESOLVED: 1973 cm_err = rtrs_rdma_route_resolved(con); 1974 break; 1975 case RDMA_CM_EVENT_ESTABLISHED: 1976 cm_err = rtrs_rdma_conn_established(con, ev); 1977 if (!cm_err) { 1978 /* 1979 * Report success and wake up. Here we abuse state_wq, 1980 * i.e. wake up without state change, but we set cm_err. 1981 */ 1982 flag_success_on_conn(con); 1983 wake_up(&clt_path->state_wq); 1984 return 0; 1985 } 1986 break; 1987 case RDMA_CM_EVENT_REJECTED: 1988 cm_err = rtrs_rdma_conn_rejected(con, ev); 1989 break; 1990 case RDMA_CM_EVENT_DISCONNECTED: 1991 /* No message for disconnecting */ 1992 cm_err = -ECONNRESET; 1993 break; 1994 case RDMA_CM_EVENT_CONNECT_ERROR: 1995 case RDMA_CM_EVENT_UNREACHABLE: 1996 case RDMA_CM_EVENT_ADDR_CHANGE: 1997 case RDMA_CM_EVENT_TIMEWAIT_EXIT: 1998 rtrs_wrn(s, "CM error (CM event: %s, err: %d)\n", 1999 rdma_event_msg(ev->event), ev->status); 2000 cm_err = -ECONNRESET; 2001 break; 2002 case RDMA_CM_EVENT_ADDR_ERROR: 2003 case RDMA_CM_EVENT_ROUTE_ERROR: 2004 rtrs_wrn(s, "CM error (CM event: %s, err: %d)\n", 2005 rdma_event_msg(ev->event), ev->status); 2006 cm_err = -EHOSTUNREACH; 2007 break; 2008 case RDMA_CM_EVENT_DEVICE_REMOVAL: 2009 /* 2010 * Device removal is a special case. Queue close and return 0. 2011 */ 2012 rtrs_clt_close_conns(clt_path, false); 2013 return 0; 2014 default: 2015 rtrs_err(s, "Unexpected RDMA CM error (CM event: %s, err: %d)\n", 2016 rdma_event_msg(ev->event), ev->status); 2017 cm_err = -ECONNRESET; 2018 break; 2019 } 2020 2021 if (cm_err) { 2022 /* 2023 * cm error makes sense only on connection establishing, 2024 * in other cases we rely on normal procedure of reconnecting. 2025 */ 2026 flag_error_on_conn(con, cm_err); 2027 rtrs_rdma_error_recovery(con); 2028 } 2029 2030 return 0; 2031 } 2032 2033 static int create_cm(struct rtrs_clt_con *con) 2034 { 2035 struct rtrs_path *s = con->c.path; 2036 struct rtrs_clt_path *clt_path = to_clt_path(s); 2037 struct rdma_cm_id *cm_id; 2038 int err; 2039 2040 cm_id = rdma_create_id(&init_net, rtrs_clt_rdma_cm_handler, con, 2041 clt_path->s.dst_addr.ss_family == AF_IB ? 2042 RDMA_PS_IB : RDMA_PS_TCP, IB_QPT_RC); 2043 if (IS_ERR(cm_id)) { 2044 err = PTR_ERR(cm_id); 2045 rtrs_err(s, "Failed to create CM ID, err: %d\n", err); 2046 2047 return err; 2048 } 2049 con->c.cm_id = cm_id; 2050 con->cm_err = 0; 2051 /* allow the port to be reused */ 2052 err = rdma_set_reuseaddr(cm_id, 1); 2053 if (err != 0) { 2054 rtrs_err(s, "Set address reuse failed, err: %d\n", err); 2055 goto destroy_cm; 2056 } 2057 err = rdma_resolve_addr(cm_id, (struct sockaddr *)&clt_path->s.src_addr, 2058 (struct sockaddr *)&clt_path->s.dst_addr, 2059 RTRS_CONNECT_TIMEOUT_MS); 2060 if (err) { 2061 rtrs_err(s, "Failed to resolve address, err: %d\n", err); 2062 goto destroy_cm; 2063 } 2064 /* 2065 * Combine connection status and session events. This is needed 2066 * for waiting two possible cases: cm_err has something meaningful 2067 * or session state was really changed to error by device removal. 2068 */ 2069 err = wait_event_interruptible_timeout( 2070 clt_path->state_wq, 2071 con->cm_err || clt_path->state != RTRS_CLT_CONNECTING, 2072 msecs_to_jiffies(RTRS_CONNECT_TIMEOUT_MS)); 2073 if (err == 0 || err == -ERESTARTSYS) { 2074 if (err == 0) 2075 err = -ETIMEDOUT; 2076 /* Timedout or interrupted */ 2077 goto errr; 2078 } 2079 if (con->cm_err < 0) { 2080 err = con->cm_err; 2081 goto errr; 2082 } 2083 if (READ_ONCE(clt_path->state) != RTRS_CLT_CONNECTING) { 2084 /* Device removal */ 2085 err = -ECONNABORTED; 2086 goto errr; 2087 } 2088 2089 return 0; 2090 2091 errr: 2092 stop_cm(con); 2093 mutex_lock(&con->con_mutex); 2094 destroy_con_cq_qp(con); 2095 mutex_unlock(&con->con_mutex); 2096 destroy_cm: 2097 destroy_cm(con); 2098 2099 return err; 2100 } 2101 2102 static void rtrs_clt_path_up(struct rtrs_clt_path *clt_path) 2103 { 2104 struct rtrs_clt_sess *clt = clt_path->clt; 2105 int up; 2106 2107 /* 2108 * We can fire RECONNECTED event only when all paths were 2109 * connected on rtrs_clt_open(), then each was disconnected 2110 * and the first one connected again. That's why this nasty 2111 * game with counter value. 2112 */ 2113 2114 mutex_lock(&clt->paths_ev_mutex); 2115 up = ++clt->paths_up; 2116 /* 2117 * Here it is safe to access paths num directly since up counter 2118 * is greater than MAX_PATHS_NUM only while rtrs_clt_open() is 2119 * in progress, thus paths removals are impossible. 2120 */ 2121 if (up > MAX_PATHS_NUM && up == MAX_PATHS_NUM + clt->paths_num) 2122 clt->paths_up = clt->paths_num; 2123 else if (up == 1) 2124 clt->link_ev(clt->priv, RTRS_CLT_LINK_EV_RECONNECTED); 2125 mutex_unlock(&clt->paths_ev_mutex); 2126 2127 /* Mark session as established */ 2128 clt_path->established = true; 2129 clt_path->reconnect_attempts = 0; 2130 clt_path->stats->reconnects.successful_cnt++; 2131 } 2132 2133 static void rtrs_clt_path_down(struct rtrs_clt_path *clt_path) 2134 { 2135 struct rtrs_clt_sess *clt = clt_path->clt; 2136 2137 if (!clt_path->established) 2138 return; 2139 2140 clt_path->established = false; 2141 mutex_lock(&clt->paths_ev_mutex); 2142 WARN_ON(!clt->paths_up); 2143 if (--clt->paths_up == 0) 2144 clt->link_ev(clt->priv, RTRS_CLT_LINK_EV_DISCONNECTED); 2145 mutex_unlock(&clt->paths_ev_mutex); 2146 } 2147 2148 static void rtrs_clt_stop_and_destroy_conns(struct rtrs_clt_path *clt_path) 2149 { 2150 struct rtrs_clt_con *con; 2151 unsigned int cid; 2152 2153 WARN_ON(READ_ONCE(clt_path->state) == RTRS_CLT_CONNECTED); 2154 2155 /* 2156 * Possible race with rtrs_clt_open(), when DEVICE_REMOVAL comes 2157 * exactly in between. Start destroying after it finishes. 2158 */ 2159 mutex_lock(&clt_path->init_mutex); 2160 mutex_unlock(&clt_path->init_mutex); 2161 2162 /* 2163 * All IO paths must observe !CONNECTED state before we 2164 * free everything. 2165 */ 2166 synchronize_rcu(); 2167 2168 rtrs_stop_hb(&clt_path->s); 2169 2170 /* 2171 * The order it utterly crucial: firstly disconnect and complete all 2172 * rdma requests with error (thus set in_use=false for requests), 2173 * then fail outstanding requests checking in_use for each, and 2174 * eventually notify upper layer about session disconnection. 2175 */ 2176 2177 for (cid = 0; cid < clt_path->s.con_num; cid++) { 2178 if (!clt_path->s.con[cid]) 2179 break; 2180 con = to_clt_con(clt_path->s.con[cid]); 2181 stop_cm(con); 2182 } 2183 fail_all_outstanding_reqs(clt_path); 2184 free_path_reqs(clt_path); 2185 rtrs_clt_path_down(clt_path); 2186 2187 /* 2188 * Wait for graceful shutdown, namely when peer side invokes 2189 * rdma_disconnect(). 'connected_cnt' is decremented only on 2190 * CM events, thus if other side had crashed and hb has detected 2191 * something is wrong, here we will stuck for exactly timeout ms, 2192 * since CM does not fire anything. That is fine, we are not in 2193 * hurry. 2194 */ 2195 wait_event_timeout(clt_path->state_wq, 2196 !atomic_read(&clt_path->connected_cnt), 2197 msecs_to_jiffies(RTRS_CONNECT_TIMEOUT_MS)); 2198 2199 for (cid = 0; cid < clt_path->s.con_num; cid++) { 2200 if (!clt_path->s.con[cid]) 2201 break; 2202 con = to_clt_con(clt_path->s.con[cid]); 2203 mutex_lock(&con->con_mutex); 2204 destroy_con_cq_qp(con); 2205 mutex_unlock(&con->con_mutex); 2206 destroy_cm(con); 2207 destroy_con(con); 2208 } 2209 } 2210 2211 static inline bool xchg_paths(struct rtrs_clt_path __rcu **rcu_ppcpu_path, 2212 struct rtrs_clt_path *clt_path, 2213 struct rtrs_clt_path *next) 2214 { 2215 struct rtrs_clt_path **ppcpu_path; 2216 2217 /* Call cmpxchg() without sparse warnings */ 2218 ppcpu_path = (typeof(ppcpu_path))rcu_ppcpu_path; 2219 return clt_path == cmpxchg(ppcpu_path, clt_path, next); 2220 } 2221 2222 static void rtrs_clt_remove_path_from_arr(struct rtrs_clt_path *clt_path) 2223 { 2224 struct rtrs_clt_sess *clt = clt_path->clt; 2225 struct rtrs_clt_path *next; 2226 bool wait_for_grace = false; 2227 int cpu; 2228 2229 mutex_lock(&clt->paths_mutex); 2230 list_del_rcu(&clt_path->s.entry); 2231 2232 /* Make sure everybody observes path removal. */ 2233 synchronize_rcu(); 2234 2235 /* 2236 * At this point nobody sees @sess in the list, but still we have 2237 * dangling pointer @pcpu_path which _can_ point to @sess. Since 2238 * nobody can observe @sess in the list, we guarantee that IO path 2239 * will not assign @sess to @pcpu_path, i.e. @pcpu_path can be equal 2240 * to @sess, but can never again become @sess. 2241 */ 2242 2243 /* 2244 * Decrement paths number only after grace period, because 2245 * caller of do_each_path() must firstly observe list without 2246 * path and only then decremented paths number. 2247 * 2248 * Otherwise there can be the following situation: 2249 * o Two paths exist and IO is coming. 2250 * o One path is removed: 2251 * CPU#0 CPU#1 2252 * do_each_path(): rtrs_clt_remove_path_from_arr(): 2253 * path = get_next_path() 2254 * ^^^ list_del_rcu(path) 2255 * [!CONNECTED path] clt->paths_num-- 2256 * ^^^^^^^^^ 2257 * load clt->paths_num from 2 to 1 2258 * ^^^^^^^^^ 2259 * sees 1 2260 * 2261 * path is observed as !CONNECTED, but do_each_path() loop 2262 * ends, because expression i < clt->paths_num is false. 2263 */ 2264 clt->paths_num--; 2265 2266 /* 2267 * Get @next connection from current @sess which is going to be 2268 * removed. If @sess is the last element, then @next is NULL. 2269 */ 2270 rcu_read_lock(); 2271 next = list_next_or_null_rr_rcu(&clt->paths_list, &clt_path->s.entry, 2272 typeof(*next), s.entry); 2273 rcu_read_unlock(); 2274 2275 /* 2276 * @pcpu paths can still point to the path which is going to be 2277 * removed, so change the pointer manually. 2278 */ 2279 for_each_possible_cpu(cpu) { 2280 struct rtrs_clt_path __rcu **ppcpu_path; 2281 2282 ppcpu_path = per_cpu_ptr(clt->pcpu_path, cpu); 2283 if (rcu_dereference_protected(*ppcpu_path, 2284 lockdep_is_held(&clt->paths_mutex)) != clt_path) 2285 /* 2286 * synchronize_rcu() was called just after deleting 2287 * entry from the list, thus IO code path cannot 2288 * change pointer back to the pointer which is going 2289 * to be removed, we are safe here. 2290 */ 2291 continue; 2292 2293 /* 2294 * We race with IO code path, which also changes pointer, 2295 * thus we have to be careful not to overwrite it. 2296 */ 2297 if (xchg_paths(ppcpu_path, clt_path, next)) 2298 /* 2299 * @ppcpu_path was successfully replaced with @next, 2300 * that means that someone could also pick up the 2301 * @sess and dereferencing it right now, so wait for 2302 * a grace period is required. 2303 */ 2304 wait_for_grace = true; 2305 } 2306 if (wait_for_grace) 2307 synchronize_rcu(); 2308 2309 mutex_unlock(&clt->paths_mutex); 2310 } 2311 2312 static void rtrs_clt_add_path_to_arr(struct rtrs_clt_path *clt_path) 2313 { 2314 struct rtrs_clt_sess *clt = clt_path->clt; 2315 2316 mutex_lock(&clt->paths_mutex); 2317 clt->paths_num++; 2318 2319 list_add_tail_rcu(&clt_path->s.entry, &clt->paths_list); 2320 mutex_unlock(&clt->paths_mutex); 2321 } 2322 2323 static void rtrs_clt_close_work(struct work_struct *work) 2324 { 2325 struct rtrs_clt_path *clt_path; 2326 2327 clt_path = container_of(work, struct rtrs_clt_path, close_work); 2328 2329 cancel_delayed_work_sync(&clt_path->reconnect_dwork); 2330 rtrs_clt_stop_and_destroy_conns(clt_path); 2331 rtrs_clt_change_state_get_old(clt_path, RTRS_CLT_CLOSED, NULL); 2332 } 2333 2334 static int init_conns(struct rtrs_clt_path *clt_path) 2335 { 2336 unsigned int cid; 2337 int err; 2338 2339 /* 2340 * On every new session connections increase reconnect counter 2341 * to avoid clashes with previous sessions not yet closed 2342 * sessions on a server side. 2343 */ 2344 clt_path->s.recon_cnt++; 2345 2346 /* Establish all RDMA connections */ 2347 for (cid = 0; cid < clt_path->s.con_num; cid++) { 2348 err = create_con(clt_path, cid); 2349 if (err) 2350 goto destroy; 2351 2352 err = create_cm(to_clt_con(clt_path->s.con[cid])); 2353 if (err) { 2354 destroy_con(to_clt_con(clt_path->s.con[cid])); 2355 goto destroy; 2356 } 2357 } 2358 err = alloc_path_reqs(clt_path); 2359 if (err) 2360 goto destroy; 2361 2362 rtrs_start_hb(&clt_path->s); 2363 2364 return 0; 2365 2366 destroy: 2367 while (cid--) { 2368 struct rtrs_clt_con *con = to_clt_con(clt_path->s.con[cid]); 2369 2370 stop_cm(con); 2371 2372 mutex_lock(&con->con_mutex); 2373 destroy_con_cq_qp(con); 2374 mutex_unlock(&con->con_mutex); 2375 destroy_cm(con); 2376 destroy_con(con); 2377 } 2378 /* 2379 * If we've never taken async path and got an error, say, 2380 * doing rdma_resolve_addr(), switch to CONNECTION_ERR state 2381 * manually to keep reconnecting. 2382 */ 2383 rtrs_clt_change_state_get_old(clt_path, RTRS_CLT_CONNECTING_ERR, NULL); 2384 2385 return err; 2386 } 2387 2388 static void rtrs_clt_info_req_done(struct ib_cq *cq, struct ib_wc *wc) 2389 { 2390 struct rtrs_clt_con *con = to_clt_con(wc->qp->qp_context); 2391 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path); 2392 struct rtrs_iu *iu; 2393 2394 iu = container_of(wc->wr_cqe, struct rtrs_iu, cqe); 2395 rtrs_iu_free(iu, clt_path->s.dev->ib_dev, 1); 2396 2397 if (wc->status != IB_WC_SUCCESS) { 2398 rtrs_err(clt_path->clt, "Path info request send failed: %s\n", 2399 ib_wc_status_msg(wc->status)); 2400 rtrs_clt_change_state_get_old(clt_path, RTRS_CLT_CONNECTING_ERR, NULL); 2401 return; 2402 } 2403 2404 rtrs_clt_update_wc_stats(con); 2405 } 2406 2407 static int process_info_rsp(struct rtrs_clt_path *clt_path, 2408 const struct rtrs_msg_info_rsp *msg) 2409 { 2410 unsigned int sg_cnt, total_len; 2411 int i, sgi; 2412 2413 sg_cnt = le16_to_cpu(msg->sg_cnt); 2414 if (!sg_cnt || (clt_path->queue_depth % sg_cnt)) { 2415 rtrs_err(clt_path->clt, 2416 "Incorrect sg_cnt %d, is not multiple\n", 2417 sg_cnt); 2418 return -EINVAL; 2419 } 2420 2421 /* 2422 * Check if IB immediate data size is enough to hold the mem_id and 2423 * the offset inside the memory chunk. 2424 */ 2425 if ((ilog2(sg_cnt - 1) + 1) + (ilog2(clt_path->chunk_size - 1) + 1) > 2426 MAX_IMM_PAYL_BITS) { 2427 rtrs_err(clt_path->clt, 2428 "RDMA immediate size (%db) not enough to encode %d buffers of size %dB\n", 2429 MAX_IMM_PAYL_BITS, sg_cnt, clt_path->chunk_size); 2430 return -EINVAL; 2431 } 2432 total_len = 0; 2433 for (sgi = 0, i = 0; sgi < sg_cnt && i < clt_path->queue_depth; sgi++) { 2434 const struct rtrs_sg_desc *desc = &msg->desc[sgi]; 2435 u32 len, rkey; 2436 u64 addr; 2437 2438 addr = le64_to_cpu(desc->addr); 2439 rkey = le32_to_cpu(desc->key); 2440 len = le32_to_cpu(desc->len); 2441 2442 total_len += len; 2443 2444 if (!len || (len % clt_path->chunk_size)) { 2445 rtrs_err(clt_path->clt, "Incorrect [%d].len %d\n", 2446 sgi, 2447 len); 2448 return -EINVAL; 2449 } 2450 for ( ; len && i < clt_path->queue_depth; i++) { 2451 clt_path->rbufs[i].addr = addr; 2452 clt_path->rbufs[i].rkey = rkey; 2453 2454 len -= clt_path->chunk_size; 2455 addr += clt_path->chunk_size; 2456 } 2457 } 2458 /* Sanity check */ 2459 if (sgi != sg_cnt || i != clt_path->queue_depth) { 2460 rtrs_err(clt_path->clt, 2461 "Incorrect sg vector, not fully mapped\n"); 2462 return -EINVAL; 2463 } 2464 if (total_len != clt_path->chunk_size * clt_path->queue_depth) { 2465 rtrs_err(clt_path->clt, "Incorrect total_len %d\n", total_len); 2466 return -EINVAL; 2467 } 2468 2469 return 0; 2470 } 2471 2472 static void rtrs_clt_info_rsp_done(struct ib_cq *cq, struct ib_wc *wc) 2473 { 2474 struct rtrs_clt_con *con = to_clt_con(wc->qp->qp_context); 2475 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path); 2476 struct rtrs_msg_info_rsp *msg; 2477 enum rtrs_clt_state state; 2478 struct rtrs_iu *iu; 2479 size_t rx_sz; 2480 int err; 2481 2482 state = RTRS_CLT_CONNECTING_ERR; 2483 2484 WARN_ON(con->c.cid); 2485 iu = container_of(wc->wr_cqe, struct rtrs_iu, cqe); 2486 if (wc->status != IB_WC_SUCCESS) { 2487 rtrs_err(clt_path->clt, "Path info response recv failed: %s\n", 2488 ib_wc_status_msg(wc->status)); 2489 goto out; 2490 } 2491 WARN_ON(wc->opcode != IB_WC_RECV); 2492 2493 if (wc->byte_len < sizeof(*msg)) { 2494 rtrs_err(clt_path->clt, "Path info response is malformed: size %d\n", 2495 wc->byte_len); 2496 goto out; 2497 } 2498 ib_dma_sync_single_for_cpu(clt_path->s.dev->ib_dev, iu->dma_addr, 2499 iu->size, DMA_FROM_DEVICE); 2500 msg = iu->buf; 2501 if (le16_to_cpu(msg->type) != RTRS_MSG_INFO_RSP) { 2502 rtrs_err(clt_path->clt, "Path info response is malformed: type %d\n", 2503 le16_to_cpu(msg->type)); 2504 goto out; 2505 } 2506 rx_sz = sizeof(*msg); 2507 rx_sz += sizeof(msg->desc[0]) * le16_to_cpu(msg->sg_cnt); 2508 if (wc->byte_len < rx_sz) { 2509 rtrs_err(clt_path->clt, "Path info response is malformed: size %d\n", 2510 wc->byte_len); 2511 goto out; 2512 } 2513 err = process_info_rsp(clt_path, msg); 2514 if (err) 2515 goto out; 2516 2517 err = post_recv_path(clt_path); 2518 if (err) 2519 goto out; 2520 2521 state = RTRS_CLT_CONNECTED; 2522 2523 out: 2524 rtrs_clt_update_wc_stats(con); 2525 rtrs_iu_free(iu, clt_path->s.dev->ib_dev, 1); 2526 rtrs_clt_change_state_get_old(clt_path, state, NULL); 2527 } 2528 2529 static int rtrs_send_path_info(struct rtrs_clt_path *clt_path) 2530 { 2531 struct rtrs_clt_con *usr_con = to_clt_con(clt_path->s.con[0]); 2532 struct rtrs_msg_info_req *msg; 2533 struct rtrs_iu *tx_iu, *rx_iu; 2534 size_t rx_sz; 2535 int err; 2536 2537 rx_sz = sizeof(struct rtrs_msg_info_rsp); 2538 rx_sz += sizeof(struct rtrs_sg_desc) * clt_path->queue_depth; 2539 2540 tx_iu = rtrs_iu_alloc(1, sizeof(struct rtrs_msg_info_req), GFP_KERNEL, 2541 clt_path->s.dev->ib_dev, DMA_TO_DEVICE, 2542 rtrs_clt_info_req_done); 2543 rx_iu = rtrs_iu_alloc(1, rx_sz, GFP_KERNEL, clt_path->s.dev->ib_dev, 2544 DMA_FROM_DEVICE, rtrs_clt_info_rsp_done); 2545 if (!tx_iu || !rx_iu) { 2546 err = -ENOMEM; 2547 goto out; 2548 } 2549 /* Prepare for getting info response */ 2550 err = rtrs_iu_post_recv(&usr_con->c, rx_iu); 2551 if (err) { 2552 rtrs_err(clt_path->clt, "rtrs_iu_post_recv(), err: %d\n", err); 2553 goto out; 2554 } 2555 rx_iu = NULL; 2556 2557 msg = tx_iu->buf; 2558 msg->type = cpu_to_le16(RTRS_MSG_INFO_REQ); 2559 memcpy(msg->pathname, clt_path->s.sessname, sizeof(msg->pathname)); 2560 2561 ib_dma_sync_single_for_device(clt_path->s.dev->ib_dev, 2562 tx_iu->dma_addr, 2563 tx_iu->size, DMA_TO_DEVICE); 2564 2565 /* Send info request */ 2566 err = rtrs_iu_post_send(&usr_con->c, tx_iu, sizeof(*msg), NULL); 2567 if (err) { 2568 rtrs_err(clt_path->clt, "rtrs_iu_post_send(), err: %d\n", err); 2569 goto out; 2570 } 2571 tx_iu = NULL; 2572 2573 /* Wait for state change */ 2574 wait_event_interruptible_timeout(clt_path->state_wq, 2575 clt_path->state != RTRS_CLT_CONNECTING, 2576 msecs_to_jiffies( 2577 RTRS_CONNECT_TIMEOUT_MS)); 2578 if (READ_ONCE(clt_path->state) != RTRS_CLT_CONNECTED) { 2579 if (READ_ONCE(clt_path->state) == RTRS_CLT_CONNECTING_ERR) 2580 err = -ECONNRESET; 2581 else 2582 err = -ETIMEDOUT; 2583 } 2584 2585 out: 2586 if (tx_iu) 2587 rtrs_iu_free(tx_iu, clt_path->s.dev->ib_dev, 1); 2588 if (rx_iu) 2589 rtrs_iu_free(rx_iu, clt_path->s.dev->ib_dev, 1); 2590 if (err) 2591 /* If we've never taken async path because of malloc problems */ 2592 rtrs_clt_change_state_get_old(clt_path, 2593 RTRS_CLT_CONNECTING_ERR, NULL); 2594 2595 return err; 2596 } 2597 2598 /** 2599 * init_path() - establishes all path connections and does handshake 2600 * @clt_path: client path. 2601 * In case of error full close or reconnect procedure should be taken, 2602 * because reconnect or close async works can be started. 2603 */ 2604 static int init_path(struct rtrs_clt_path *clt_path) 2605 { 2606 int err; 2607 char str[NAME_MAX]; 2608 struct rtrs_addr path = { 2609 .src = &clt_path->s.src_addr, 2610 .dst = &clt_path->s.dst_addr, 2611 }; 2612 2613 rtrs_addr_to_str(&path, str, sizeof(str)); 2614 2615 mutex_lock(&clt_path->init_mutex); 2616 err = init_conns(clt_path); 2617 if (err) { 2618 rtrs_err(clt_path->clt, 2619 "init_conns() failed: err=%d path=%s [%s:%u]\n", err, 2620 str, clt_path->hca_name, clt_path->hca_port); 2621 goto out; 2622 } 2623 err = rtrs_send_path_info(clt_path); 2624 if (err) { 2625 rtrs_err(clt_path->clt, 2626 "rtrs_send_path_info() failed: err=%d path=%s [%s:%u]\n", 2627 err, str, clt_path->hca_name, clt_path->hca_port); 2628 goto out; 2629 } 2630 rtrs_clt_path_up(clt_path); 2631 out: 2632 mutex_unlock(&clt_path->init_mutex); 2633 2634 return err; 2635 } 2636 2637 static void rtrs_clt_reconnect_work(struct work_struct *work) 2638 { 2639 struct rtrs_clt_path *clt_path; 2640 struct rtrs_clt_sess *clt; 2641 unsigned int delay_ms; 2642 int err; 2643 2644 clt_path = container_of(to_delayed_work(work), struct rtrs_clt_path, 2645 reconnect_dwork); 2646 clt = clt_path->clt; 2647 2648 if (READ_ONCE(clt_path->state) != RTRS_CLT_RECONNECTING) 2649 return; 2650 2651 if (clt_path->reconnect_attempts >= clt->max_reconnect_attempts) { 2652 /* Close a path completely if max attempts is reached */ 2653 rtrs_clt_close_conns(clt_path, false); 2654 return; 2655 } 2656 clt_path->reconnect_attempts++; 2657 2658 /* Stop everything */ 2659 rtrs_clt_stop_and_destroy_conns(clt_path); 2660 msleep(RTRS_RECONNECT_BACKOFF); 2661 if (rtrs_clt_change_state_get_old(clt_path, RTRS_CLT_CONNECTING, NULL)) { 2662 err = init_path(clt_path); 2663 if (err) 2664 goto reconnect_again; 2665 } 2666 2667 return; 2668 2669 reconnect_again: 2670 if (rtrs_clt_change_state_get_old(clt_path, RTRS_CLT_RECONNECTING, NULL)) { 2671 clt_path->stats->reconnects.fail_cnt++; 2672 delay_ms = clt->reconnect_delay_sec * 1000; 2673 queue_delayed_work(rtrs_wq, &clt_path->reconnect_dwork, 2674 msecs_to_jiffies(delay_ms + 2675 prandom_u32() % 2676 RTRS_RECONNECT_SEED)); 2677 } 2678 } 2679 2680 static void rtrs_clt_dev_release(struct device *dev) 2681 { 2682 struct rtrs_clt_sess *clt = container_of(dev, struct rtrs_clt_sess, 2683 dev); 2684 2685 kfree(clt); 2686 } 2687 2688 static struct rtrs_clt_sess *alloc_clt(const char *sessname, size_t paths_num, 2689 u16 port, size_t pdu_sz, void *priv, 2690 void (*link_ev)(void *priv, 2691 enum rtrs_clt_link_ev ev), 2692 unsigned int reconnect_delay_sec, 2693 unsigned int max_reconnect_attempts) 2694 { 2695 struct rtrs_clt_sess *clt; 2696 int err; 2697 2698 if (!paths_num || paths_num > MAX_PATHS_NUM) 2699 return ERR_PTR(-EINVAL); 2700 2701 if (strlen(sessname) >= sizeof(clt->sessname)) 2702 return ERR_PTR(-EINVAL); 2703 2704 clt = kzalloc(sizeof(*clt), GFP_KERNEL); 2705 if (!clt) 2706 return ERR_PTR(-ENOMEM); 2707 2708 clt->pcpu_path = alloc_percpu(typeof(*clt->pcpu_path)); 2709 if (!clt->pcpu_path) { 2710 kfree(clt); 2711 return ERR_PTR(-ENOMEM); 2712 } 2713 2714 uuid_gen(&clt->paths_uuid); 2715 INIT_LIST_HEAD_RCU(&clt->paths_list); 2716 clt->paths_num = paths_num; 2717 clt->paths_up = MAX_PATHS_NUM; 2718 clt->port = port; 2719 clt->pdu_sz = pdu_sz; 2720 clt->max_segments = RTRS_MAX_SEGMENTS; 2721 clt->reconnect_delay_sec = reconnect_delay_sec; 2722 clt->max_reconnect_attempts = max_reconnect_attempts; 2723 clt->priv = priv; 2724 clt->link_ev = link_ev; 2725 clt->mp_policy = MP_POLICY_MIN_INFLIGHT; 2726 strscpy(clt->sessname, sessname, sizeof(clt->sessname)); 2727 init_waitqueue_head(&clt->permits_wait); 2728 mutex_init(&clt->paths_ev_mutex); 2729 mutex_init(&clt->paths_mutex); 2730 2731 clt->dev.class = rtrs_clt_dev_class; 2732 clt->dev.release = rtrs_clt_dev_release; 2733 err = dev_set_name(&clt->dev, "%s", sessname); 2734 if (err) 2735 goto err; 2736 /* 2737 * Suppress user space notification until 2738 * sysfs files are created 2739 */ 2740 dev_set_uevent_suppress(&clt->dev, true); 2741 err = device_register(&clt->dev); 2742 if (err) { 2743 put_device(&clt->dev); 2744 goto err; 2745 } 2746 2747 clt->kobj_paths = kobject_create_and_add("paths", &clt->dev.kobj); 2748 if (!clt->kobj_paths) { 2749 err = -ENOMEM; 2750 goto err_dev; 2751 } 2752 err = rtrs_clt_create_sysfs_root_files(clt); 2753 if (err) { 2754 kobject_del(clt->kobj_paths); 2755 kobject_put(clt->kobj_paths); 2756 goto err_dev; 2757 } 2758 dev_set_uevent_suppress(&clt->dev, false); 2759 kobject_uevent(&clt->dev.kobj, KOBJ_ADD); 2760 2761 return clt; 2762 err_dev: 2763 device_unregister(&clt->dev); 2764 err: 2765 free_percpu(clt->pcpu_path); 2766 kfree(clt); 2767 return ERR_PTR(err); 2768 } 2769 2770 static void free_clt(struct rtrs_clt_sess *clt) 2771 { 2772 free_permits(clt); 2773 free_percpu(clt->pcpu_path); 2774 mutex_destroy(&clt->paths_ev_mutex); 2775 mutex_destroy(&clt->paths_mutex); 2776 /* release callback will free clt in last put */ 2777 device_unregister(&clt->dev); 2778 } 2779 2780 /** 2781 * rtrs_clt_open() - Open a path to an RTRS server 2782 * @ops: holds the link event callback and the private pointer. 2783 * @sessname: name of the session 2784 * @paths: Paths to be established defined by their src and dst addresses 2785 * @paths_num: Number of elements in the @paths array 2786 * @port: port to be used by the RTRS session 2787 * @pdu_sz: Size of extra payload which can be accessed after permit allocation. 2788 * @reconnect_delay_sec: time between reconnect tries 2789 * @max_reconnect_attempts: Number of times to reconnect on error before giving 2790 * up, 0 for * disabled, -1 for forever 2791 * @nr_poll_queues: number of polling mode connection using IB_POLL_DIRECT flag 2792 * 2793 * Starts session establishment with the rtrs_server. The function can block 2794 * up to ~2000ms before it returns. 2795 * 2796 * Return a valid pointer on success otherwise PTR_ERR. 2797 */ 2798 struct rtrs_clt_sess *rtrs_clt_open(struct rtrs_clt_ops *ops, 2799 const char *pathname, 2800 const struct rtrs_addr *paths, 2801 size_t paths_num, u16 port, 2802 size_t pdu_sz, u8 reconnect_delay_sec, 2803 s16 max_reconnect_attempts, u32 nr_poll_queues) 2804 { 2805 struct rtrs_clt_path *clt_path, *tmp; 2806 struct rtrs_clt_sess *clt; 2807 int err, i; 2808 2809 if (strchr(pathname, '/') || strchr(pathname, '.')) { 2810 pr_err("pathname cannot contain / and .\n"); 2811 err = -EINVAL; 2812 goto out; 2813 } 2814 2815 clt = alloc_clt(pathname, paths_num, port, pdu_sz, ops->priv, 2816 ops->link_ev, 2817 reconnect_delay_sec, 2818 max_reconnect_attempts); 2819 if (IS_ERR(clt)) { 2820 err = PTR_ERR(clt); 2821 goto out; 2822 } 2823 for (i = 0; i < paths_num; i++) { 2824 struct rtrs_clt_path *clt_path; 2825 2826 clt_path = alloc_path(clt, &paths[i], nr_cpu_ids, 2827 nr_poll_queues); 2828 if (IS_ERR(clt_path)) { 2829 err = PTR_ERR(clt_path); 2830 goto close_all_path; 2831 } 2832 if (!i) 2833 clt_path->for_new_clt = 1; 2834 list_add_tail_rcu(&clt_path->s.entry, &clt->paths_list); 2835 2836 err = init_path(clt_path); 2837 if (err) { 2838 list_del_rcu(&clt_path->s.entry); 2839 rtrs_clt_close_conns(clt_path, true); 2840 free_percpu(clt_path->stats->pcpu_stats); 2841 kfree(clt_path->stats); 2842 free_path(clt_path); 2843 goto close_all_path; 2844 } 2845 2846 err = rtrs_clt_create_path_files(clt_path); 2847 if (err) { 2848 list_del_rcu(&clt_path->s.entry); 2849 rtrs_clt_close_conns(clt_path, true); 2850 free_percpu(clt_path->stats->pcpu_stats); 2851 kfree(clt_path->stats); 2852 free_path(clt_path); 2853 goto close_all_path; 2854 } 2855 } 2856 err = alloc_permits(clt); 2857 if (err) 2858 goto close_all_path; 2859 2860 return clt; 2861 2862 close_all_path: 2863 list_for_each_entry_safe(clt_path, tmp, &clt->paths_list, s.entry) { 2864 rtrs_clt_destroy_path_files(clt_path, NULL); 2865 rtrs_clt_close_conns(clt_path, true); 2866 kobject_put(&clt_path->kobj); 2867 } 2868 rtrs_clt_destroy_sysfs_root(clt); 2869 free_clt(clt); 2870 2871 out: 2872 return ERR_PTR(err); 2873 } 2874 EXPORT_SYMBOL(rtrs_clt_open); 2875 2876 /** 2877 * rtrs_clt_close() - Close a path 2878 * @clt: Session handle. Session is freed upon return. 2879 */ 2880 void rtrs_clt_close(struct rtrs_clt_sess *clt) 2881 { 2882 struct rtrs_clt_path *clt_path, *tmp; 2883 2884 /* Firstly forbid sysfs access */ 2885 rtrs_clt_destroy_sysfs_root(clt); 2886 2887 /* Now it is safe to iterate over all paths without locks */ 2888 list_for_each_entry_safe(clt_path, tmp, &clt->paths_list, s.entry) { 2889 rtrs_clt_close_conns(clt_path, true); 2890 rtrs_clt_destroy_path_files(clt_path, NULL); 2891 kobject_put(&clt_path->kobj); 2892 } 2893 free_clt(clt); 2894 } 2895 EXPORT_SYMBOL(rtrs_clt_close); 2896 2897 int rtrs_clt_reconnect_from_sysfs(struct rtrs_clt_path *clt_path) 2898 { 2899 enum rtrs_clt_state old_state; 2900 int err = -EBUSY; 2901 bool changed; 2902 2903 changed = rtrs_clt_change_state_get_old(clt_path, 2904 RTRS_CLT_RECONNECTING, 2905 &old_state); 2906 if (changed) { 2907 clt_path->reconnect_attempts = 0; 2908 queue_delayed_work(rtrs_wq, &clt_path->reconnect_dwork, 0); 2909 } 2910 if (changed || old_state == RTRS_CLT_RECONNECTING) { 2911 /* 2912 * flush_delayed_work() queues pending work for immediate 2913 * execution, so do the flush if we have queued something 2914 * right now or work is pending. 2915 */ 2916 flush_delayed_work(&clt_path->reconnect_dwork); 2917 err = (READ_ONCE(clt_path->state) == 2918 RTRS_CLT_CONNECTED ? 0 : -ENOTCONN); 2919 } 2920 2921 return err; 2922 } 2923 2924 int rtrs_clt_remove_path_from_sysfs(struct rtrs_clt_path *clt_path, 2925 const struct attribute *sysfs_self) 2926 { 2927 enum rtrs_clt_state old_state; 2928 bool changed; 2929 2930 /* 2931 * Continue stopping path till state was changed to DEAD or 2932 * state was observed as DEAD: 2933 * 1. State was changed to DEAD - we were fast and nobody 2934 * invoked rtrs_clt_reconnect(), which can again start 2935 * reconnecting. 2936 * 2. State was observed as DEAD - we have someone in parallel 2937 * removing the path. 2938 */ 2939 do { 2940 rtrs_clt_close_conns(clt_path, true); 2941 changed = rtrs_clt_change_state_get_old(clt_path, 2942 RTRS_CLT_DEAD, 2943 &old_state); 2944 } while (!changed && old_state != RTRS_CLT_DEAD); 2945 2946 if (changed) { 2947 rtrs_clt_remove_path_from_arr(clt_path); 2948 rtrs_clt_destroy_path_files(clt_path, sysfs_self); 2949 kobject_put(&clt_path->kobj); 2950 } 2951 2952 return 0; 2953 } 2954 2955 void rtrs_clt_set_max_reconnect_attempts(struct rtrs_clt_sess *clt, int value) 2956 { 2957 clt->max_reconnect_attempts = (unsigned int)value; 2958 } 2959 2960 int rtrs_clt_get_max_reconnect_attempts(const struct rtrs_clt_sess *clt) 2961 { 2962 return (int)clt->max_reconnect_attempts; 2963 } 2964 2965 /** 2966 * rtrs_clt_request() - Request data transfer to/from server via RDMA. 2967 * 2968 * @dir: READ/WRITE 2969 * @ops: callback function to be called as confirmation, and the pointer. 2970 * @clt: Session 2971 * @permit: Preallocated permit 2972 * @vec: Message that is sent to server together with the request. 2973 * Sum of len of all @vec elements limited to <= IO_MSG_SIZE. 2974 * Since the msg is copied internally it can be allocated on stack. 2975 * @nr: Number of elements in @vec. 2976 * @data_len: length of data sent to/from server 2977 * @sg: Pages to be sent/received to/from server. 2978 * @sg_cnt: Number of elements in the @sg 2979 * 2980 * Return: 2981 * 0: Success 2982 * <0: Error 2983 * 2984 * On dir=READ rtrs client will request a data transfer from Server to client. 2985 * The data that the server will respond with will be stored in @sg when 2986 * the user receives an %RTRS_CLT_RDMA_EV_RDMA_REQUEST_WRITE_COMPL event. 2987 * On dir=WRITE rtrs client will rdma write data in sg to server side. 2988 */ 2989 int rtrs_clt_request(int dir, struct rtrs_clt_req_ops *ops, 2990 struct rtrs_clt_sess *clt, struct rtrs_permit *permit, 2991 const struct kvec *vec, size_t nr, size_t data_len, 2992 struct scatterlist *sg, unsigned int sg_cnt) 2993 { 2994 struct rtrs_clt_io_req *req; 2995 struct rtrs_clt_path *clt_path; 2996 2997 enum dma_data_direction dma_dir; 2998 int err = -ECONNABORTED, i; 2999 size_t usr_len, hdr_len; 3000 struct path_it it; 3001 3002 /* Get kvec length */ 3003 for (i = 0, usr_len = 0; i < nr; i++) 3004 usr_len += vec[i].iov_len; 3005 3006 if (dir == READ) { 3007 hdr_len = sizeof(struct rtrs_msg_rdma_read) + 3008 sg_cnt * sizeof(struct rtrs_sg_desc); 3009 dma_dir = DMA_FROM_DEVICE; 3010 } else { 3011 hdr_len = sizeof(struct rtrs_msg_rdma_write); 3012 dma_dir = DMA_TO_DEVICE; 3013 } 3014 3015 rcu_read_lock(); 3016 for (path_it_init(&it, clt); 3017 (clt_path = it.next_path(&it)) && it.i < it.clt->paths_num; it.i++) { 3018 if (READ_ONCE(clt_path->state) != RTRS_CLT_CONNECTED) 3019 continue; 3020 3021 if (usr_len + hdr_len > clt_path->max_hdr_size) { 3022 rtrs_wrn_rl(clt_path->clt, 3023 "%s request failed, user message size is %zu and header length %zu, but max size is %u\n", 3024 dir == READ ? "Read" : "Write", 3025 usr_len, hdr_len, clt_path->max_hdr_size); 3026 err = -EMSGSIZE; 3027 break; 3028 } 3029 req = rtrs_clt_get_req(clt_path, ops->conf_fn, permit, ops->priv, 3030 vec, usr_len, sg, sg_cnt, data_len, 3031 dma_dir); 3032 if (dir == READ) 3033 err = rtrs_clt_read_req(req); 3034 else 3035 err = rtrs_clt_write_req(req); 3036 if (err) { 3037 req->in_use = false; 3038 continue; 3039 } 3040 /* Success path */ 3041 break; 3042 } 3043 path_it_deinit(&it); 3044 rcu_read_unlock(); 3045 3046 return err; 3047 } 3048 EXPORT_SYMBOL(rtrs_clt_request); 3049 3050 int rtrs_clt_rdma_cq_direct(struct rtrs_clt_sess *clt, unsigned int index) 3051 { 3052 /* If no path, return -1 for block layer not to try again */ 3053 int cnt = -1; 3054 struct rtrs_con *con; 3055 struct rtrs_clt_path *clt_path; 3056 struct path_it it; 3057 3058 rcu_read_lock(); 3059 for (path_it_init(&it, clt); 3060 (clt_path = it.next_path(&it)) && it.i < it.clt->paths_num; it.i++) { 3061 if (READ_ONCE(clt_path->state) != RTRS_CLT_CONNECTED) 3062 continue; 3063 3064 con = clt_path->s.con[index + 1]; 3065 cnt = ib_process_cq_direct(con->cq, -1); 3066 if (cnt) 3067 break; 3068 } 3069 path_it_deinit(&it); 3070 rcu_read_unlock(); 3071 3072 return cnt; 3073 } 3074 EXPORT_SYMBOL(rtrs_clt_rdma_cq_direct); 3075 3076 /** 3077 * rtrs_clt_query() - queries RTRS session attributes 3078 *@clt: session pointer 3079 *@attr: query results for session attributes. 3080 * Returns: 3081 * 0 on success 3082 * -ECOMM no connection to the server 3083 */ 3084 int rtrs_clt_query(struct rtrs_clt_sess *clt, struct rtrs_attrs *attr) 3085 { 3086 if (!rtrs_clt_is_connected(clt)) 3087 return -ECOMM; 3088 3089 attr->queue_depth = clt->queue_depth; 3090 attr->max_segments = clt->max_segments; 3091 /* Cap max_io_size to min of remote buffer size and the fr pages */ 3092 attr->max_io_size = min_t(int, clt->max_io_size, 3093 clt->max_segments * SZ_4K); 3094 3095 return 0; 3096 } 3097 EXPORT_SYMBOL(rtrs_clt_query); 3098 3099 int rtrs_clt_create_path_from_sysfs(struct rtrs_clt_sess *clt, 3100 struct rtrs_addr *addr) 3101 { 3102 struct rtrs_clt_path *clt_path; 3103 int err; 3104 3105 clt_path = alloc_path(clt, addr, nr_cpu_ids, 0); 3106 if (IS_ERR(clt_path)) 3107 return PTR_ERR(clt_path); 3108 3109 mutex_lock(&clt->paths_mutex); 3110 if (clt->paths_num == 0) { 3111 /* 3112 * When all the paths are removed for a session, 3113 * the addition of the first path is like a new session for 3114 * the storage server 3115 */ 3116 clt_path->for_new_clt = 1; 3117 } 3118 3119 mutex_unlock(&clt->paths_mutex); 3120 3121 /* 3122 * It is totally safe to add path in CONNECTING state: coming 3123 * IO will never grab it. Also it is very important to add 3124 * path before init, since init fires LINK_CONNECTED event. 3125 */ 3126 rtrs_clt_add_path_to_arr(clt_path); 3127 3128 err = init_path(clt_path); 3129 if (err) 3130 goto close_path; 3131 3132 err = rtrs_clt_create_path_files(clt_path); 3133 if (err) 3134 goto close_path; 3135 3136 return 0; 3137 3138 close_path: 3139 rtrs_clt_remove_path_from_arr(clt_path); 3140 rtrs_clt_close_conns(clt_path, true); 3141 free_percpu(clt_path->stats->pcpu_stats); 3142 kfree(clt_path->stats); 3143 free_path(clt_path); 3144 3145 return err; 3146 } 3147 3148 static int rtrs_clt_ib_dev_init(struct rtrs_ib_dev *dev) 3149 { 3150 if (!(dev->ib_dev->attrs.device_cap_flags & 3151 IB_DEVICE_MEM_MGT_EXTENSIONS)) { 3152 pr_err("Memory registrations not supported.\n"); 3153 return -ENOTSUPP; 3154 } 3155 3156 return 0; 3157 } 3158 3159 static const struct rtrs_rdma_dev_pd_ops dev_pd_ops = { 3160 .init = rtrs_clt_ib_dev_init 3161 }; 3162 3163 static int __init rtrs_client_init(void) 3164 { 3165 rtrs_rdma_dev_pd_init(0, &dev_pd); 3166 3167 rtrs_clt_dev_class = class_create(THIS_MODULE, "rtrs-client"); 3168 if (IS_ERR(rtrs_clt_dev_class)) { 3169 pr_err("Failed to create rtrs-client dev class\n"); 3170 return PTR_ERR(rtrs_clt_dev_class); 3171 } 3172 rtrs_wq = alloc_workqueue("rtrs_client_wq", 0, 0); 3173 if (!rtrs_wq) { 3174 class_destroy(rtrs_clt_dev_class); 3175 return -ENOMEM; 3176 } 3177 3178 return 0; 3179 } 3180 3181 static void __exit rtrs_client_exit(void) 3182 { 3183 destroy_workqueue(rtrs_wq); 3184 class_destroy(rtrs_clt_dev_class); 3185 rtrs_rdma_dev_pd_deinit(&dev_pd); 3186 } 3187 3188 module_init(rtrs_client_init); 3189 module_exit(rtrs_client_exit); 3190