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_clt_stop_and_destroy_conns(struct rtrs_clt_path *clt_path); 301 static void rtrs_rdma_error_recovery(struct rtrs_clt_con *con) 302 { 303 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path); 304 305 if (rtrs_clt_change_state_from_to(clt_path, 306 RTRS_CLT_CONNECTED, 307 RTRS_CLT_RECONNECTING)) { 308 queue_work(rtrs_wq, &clt_path->err_recovery_work); 309 } else { 310 /* 311 * Error can happen just on establishing new connection, 312 * so notify waiter with error state, waiter is responsible 313 * for cleaning the rest and reconnect if needed. 314 */ 315 rtrs_clt_change_state_from_to(clt_path, 316 RTRS_CLT_CONNECTING, 317 RTRS_CLT_CONNECTING_ERR); 318 } 319 } 320 321 static void rtrs_clt_fast_reg_done(struct ib_cq *cq, struct ib_wc *wc) 322 { 323 struct rtrs_clt_con *con = to_clt_con(wc->qp->qp_context); 324 325 if (wc->status != IB_WC_SUCCESS) { 326 rtrs_err(con->c.path, "Failed IB_WR_REG_MR: %s\n", 327 ib_wc_status_msg(wc->status)); 328 rtrs_rdma_error_recovery(con); 329 } 330 } 331 332 static struct ib_cqe fast_reg_cqe = { 333 .done = rtrs_clt_fast_reg_done 334 }; 335 336 static void complete_rdma_req(struct rtrs_clt_io_req *req, int errno, 337 bool notify, bool can_wait); 338 339 static void rtrs_clt_inv_rkey_done(struct ib_cq *cq, struct ib_wc *wc) 340 { 341 struct rtrs_clt_io_req *req = 342 container_of(wc->wr_cqe, typeof(*req), inv_cqe); 343 struct rtrs_clt_con *con = to_clt_con(wc->qp->qp_context); 344 345 if (wc->status != IB_WC_SUCCESS) { 346 rtrs_err(con->c.path, "Failed IB_WR_LOCAL_INV: %s\n", 347 ib_wc_status_msg(wc->status)); 348 rtrs_rdma_error_recovery(con); 349 } 350 req->need_inv = false; 351 if (req->need_inv_comp) 352 complete(&req->inv_comp); 353 else 354 /* Complete request from INV callback */ 355 complete_rdma_req(req, req->inv_errno, true, false); 356 } 357 358 static int rtrs_inv_rkey(struct rtrs_clt_io_req *req) 359 { 360 struct rtrs_clt_con *con = req->con; 361 struct ib_send_wr wr = { 362 .opcode = IB_WR_LOCAL_INV, 363 .wr_cqe = &req->inv_cqe, 364 .send_flags = IB_SEND_SIGNALED, 365 .ex.invalidate_rkey = req->mr->rkey, 366 }; 367 req->inv_cqe.done = rtrs_clt_inv_rkey_done; 368 369 return ib_post_send(con->c.qp, &wr, NULL); 370 } 371 372 static void complete_rdma_req(struct rtrs_clt_io_req *req, int errno, 373 bool notify, bool can_wait) 374 { 375 struct rtrs_clt_con *con = req->con; 376 struct rtrs_clt_path *clt_path; 377 int err; 378 379 if (WARN_ON(!req->in_use)) 380 return; 381 if (WARN_ON(!req->con)) 382 return; 383 clt_path = to_clt_path(con->c.path); 384 385 if (req->sg_cnt) { 386 if (req->dir == DMA_FROM_DEVICE && req->need_inv) { 387 /* 388 * We are here to invalidate read requests 389 * ourselves. In normal scenario server should 390 * send INV for all read requests, but 391 * we are here, thus two things could happen: 392 * 393 * 1. this is failover, when errno != 0 394 * and can_wait == 1, 395 * 396 * 2. something totally bad happened and 397 * server forgot to send INV, so we 398 * should do that ourselves. 399 */ 400 401 if (can_wait) { 402 req->need_inv_comp = true; 403 } else { 404 /* This should be IO path, so always notify */ 405 WARN_ON(!notify); 406 /* Save errno for INV callback */ 407 req->inv_errno = errno; 408 } 409 410 refcount_inc(&req->ref); 411 err = rtrs_inv_rkey(req); 412 if (err) { 413 rtrs_err(con->c.path, "Send INV WR key=%#x: %d\n", 414 req->mr->rkey, err); 415 } else if (can_wait) { 416 wait_for_completion(&req->inv_comp); 417 } else { 418 /* 419 * Something went wrong, so request will be 420 * completed from INV callback. 421 */ 422 WARN_ON_ONCE(1); 423 424 return; 425 } 426 if (!refcount_dec_and_test(&req->ref)) 427 return; 428 } 429 ib_dma_unmap_sg(clt_path->s.dev->ib_dev, req->sglist, 430 req->sg_cnt, req->dir); 431 } 432 if (!refcount_dec_and_test(&req->ref)) 433 return; 434 if (req->mp_policy == MP_POLICY_MIN_INFLIGHT) 435 atomic_dec(&clt_path->stats->inflight); 436 437 req->in_use = false; 438 req->con = NULL; 439 440 if (errno) { 441 rtrs_err_rl(con->c.path, "IO request failed: error=%d path=%s [%s:%u] notify=%d\n", 442 errno, kobject_name(&clt_path->kobj), clt_path->hca_name, 443 clt_path->hca_port, notify); 444 } 445 446 if (notify) 447 req->conf(req->priv, errno); 448 } 449 450 static int rtrs_post_send_rdma(struct rtrs_clt_con *con, 451 struct rtrs_clt_io_req *req, 452 struct rtrs_rbuf *rbuf, u32 off, 453 u32 imm, struct ib_send_wr *wr) 454 { 455 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path); 456 enum ib_send_flags flags; 457 struct ib_sge sge; 458 459 if (!req->sg_size) { 460 rtrs_wrn(con->c.path, 461 "Doing RDMA Write failed, no data supplied\n"); 462 return -EINVAL; 463 } 464 465 /* user data and user message in the first list element */ 466 sge.addr = req->iu->dma_addr; 467 sge.length = req->sg_size; 468 sge.lkey = clt_path->s.dev->ib_pd->local_dma_lkey; 469 470 /* 471 * From time to time we have to post signalled sends, 472 * or send queue will fill up and only QP reset can help. 473 */ 474 flags = atomic_inc_return(&con->c.wr_cnt) % clt_path->s.signal_interval ? 475 0 : IB_SEND_SIGNALED; 476 477 ib_dma_sync_single_for_device(clt_path->s.dev->ib_dev, 478 req->iu->dma_addr, 479 req->sg_size, DMA_TO_DEVICE); 480 481 return rtrs_iu_post_rdma_write_imm(&con->c, req->iu, &sge, 1, 482 rbuf->rkey, rbuf->addr + off, 483 imm, flags, wr, NULL); 484 } 485 486 static void process_io_rsp(struct rtrs_clt_path *clt_path, u32 msg_id, 487 s16 errno, bool w_inval) 488 { 489 struct rtrs_clt_io_req *req; 490 491 if (WARN_ON(msg_id >= clt_path->queue_depth)) 492 return; 493 494 req = &clt_path->reqs[msg_id]; 495 /* Drop need_inv if server responded with send with invalidation */ 496 req->need_inv &= !w_inval; 497 complete_rdma_req(req, errno, true, false); 498 } 499 500 static void rtrs_clt_recv_done(struct rtrs_clt_con *con, struct ib_wc *wc) 501 { 502 struct rtrs_iu *iu; 503 int err; 504 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path); 505 506 WARN_ON((clt_path->flags & RTRS_MSG_NEW_RKEY_F) == 0); 507 iu = container_of(wc->wr_cqe, struct rtrs_iu, 508 cqe); 509 err = rtrs_iu_post_recv(&con->c, iu); 510 if (err) { 511 rtrs_err(con->c.path, "post iu failed %d\n", err); 512 rtrs_rdma_error_recovery(con); 513 } 514 } 515 516 static void rtrs_clt_rkey_rsp_done(struct rtrs_clt_con *con, struct ib_wc *wc) 517 { 518 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path); 519 struct rtrs_msg_rkey_rsp *msg; 520 u32 imm_type, imm_payload; 521 bool w_inval = false; 522 struct rtrs_iu *iu; 523 u32 buf_id; 524 int err; 525 526 WARN_ON((clt_path->flags & RTRS_MSG_NEW_RKEY_F) == 0); 527 528 iu = container_of(wc->wr_cqe, struct rtrs_iu, cqe); 529 530 if (wc->byte_len < sizeof(*msg)) { 531 rtrs_err(con->c.path, "rkey response is malformed: size %d\n", 532 wc->byte_len); 533 goto out; 534 } 535 ib_dma_sync_single_for_cpu(clt_path->s.dev->ib_dev, iu->dma_addr, 536 iu->size, DMA_FROM_DEVICE); 537 msg = iu->buf; 538 if (le16_to_cpu(msg->type) != RTRS_MSG_RKEY_RSP) { 539 rtrs_err(clt_path->clt, 540 "rkey response is malformed: type %d\n", 541 le16_to_cpu(msg->type)); 542 goto out; 543 } 544 buf_id = le16_to_cpu(msg->buf_id); 545 if (WARN_ON(buf_id >= clt_path->queue_depth)) 546 goto out; 547 548 rtrs_from_imm(be32_to_cpu(wc->ex.imm_data), &imm_type, &imm_payload); 549 if (imm_type == RTRS_IO_RSP_IMM || 550 imm_type == RTRS_IO_RSP_W_INV_IMM) { 551 u32 msg_id; 552 553 w_inval = (imm_type == RTRS_IO_RSP_W_INV_IMM); 554 rtrs_from_io_rsp_imm(imm_payload, &msg_id, &err); 555 556 if (WARN_ON(buf_id != msg_id)) 557 goto out; 558 clt_path->rbufs[buf_id].rkey = le32_to_cpu(msg->rkey); 559 process_io_rsp(clt_path, msg_id, err, w_inval); 560 } 561 ib_dma_sync_single_for_device(clt_path->s.dev->ib_dev, iu->dma_addr, 562 iu->size, DMA_FROM_DEVICE); 563 return rtrs_clt_recv_done(con, wc); 564 out: 565 rtrs_rdma_error_recovery(con); 566 } 567 568 static void rtrs_clt_rdma_done(struct ib_cq *cq, struct ib_wc *wc); 569 570 static struct ib_cqe io_comp_cqe = { 571 .done = rtrs_clt_rdma_done 572 }; 573 574 /* 575 * Post x2 empty WRs: first is for this RDMA with IMM, 576 * second is for RECV with INV, which happened earlier. 577 */ 578 static int rtrs_post_recv_empty_x2(struct rtrs_con *con, struct ib_cqe *cqe) 579 { 580 struct ib_recv_wr wr_arr[2], *wr; 581 int i; 582 583 memset(wr_arr, 0, sizeof(wr_arr)); 584 for (i = 0; i < ARRAY_SIZE(wr_arr); i++) { 585 wr = &wr_arr[i]; 586 wr->wr_cqe = cqe; 587 if (i) 588 /* Chain backwards */ 589 wr->next = &wr_arr[i - 1]; 590 } 591 592 return ib_post_recv(con->qp, wr, NULL); 593 } 594 595 static void rtrs_clt_rdma_done(struct ib_cq *cq, struct ib_wc *wc) 596 { 597 struct rtrs_clt_con *con = to_clt_con(wc->qp->qp_context); 598 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path); 599 u32 imm_type, imm_payload; 600 bool w_inval = false; 601 int err; 602 603 if (wc->status != IB_WC_SUCCESS) { 604 if (wc->status != IB_WC_WR_FLUSH_ERR) { 605 rtrs_err(clt_path->clt, "RDMA failed: %s\n", 606 ib_wc_status_msg(wc->status)); 607 rtrs_rdma_error_recovery(con); 608 } 609 return; 610 } 611 rtrs_clt_update_wc_stats(con); 612 613 switch (wc->opcode) { 614 case IB_WC_RECV_RDMA_WITH_IMM: 615 /* 616 * post_recv() RDMA write completions of IO reqs (read/write) 617 * and hb 618 */ 619 if (WARN_ON(wc->wr_cqe->done != rtrs_clt_rdma_done)) 620 return; 621 rtrs_from_imm(be32_to_cpu(wc->ex.imm_data), 622 &imm_type, &imm_payload); 623 if (imm_type == RTRS_IO_RSP_IMM || 624 imm_type == RTRS_IO_RSP_W_INV_IMM) { 625 u32 msg_id; 626 627 w_inval = (imm_type == RTRS_IO_RSP_W_INV_IMM); 628 rtrs_from_io_rsp_imm(imm_payload, &msg_id, &err); 629 630 process_io_rsp(clt_path, msg_id, err, w_inval); 631 } else if (imm_type == RTRS_HB_MSG_IMM) { 632 WARN_ON(con->c.cid); 633 rtrs_send_hb_ack(&clt_path->s); 634 if (clt_path->flags & RTRS_MSG_NEW_RKEY_F) 635 return rtrs_clt_recv_done(con, wc); 636 } else if (imm_type == RTRS_HB_ACK_IMM) { 637 WARN_ON(con->c.cid); 638 clt_path->s.hb_missed_cnt = 0; 639 clt_path->s.hb_cur_latency = 640 ktime_sub(ktime_get(), clt_path->s.hb_last_sent); 641 if (clt_path->flags & RTRS_MSG_NEW_RKEY_F) 642 return rtrs_clt_recv_done(con, wc); 643 } else { 644 rtrs_wrn(con->c.path, "Unknown IMM type %u\n", 645 imm_type); 646 } 647 if (w_inval) 648 /* 649 * Post x2 empty WRs: first is for this RDMA with IMM, 650 * second is for RECV with INV, which happened earlier. 651 */ 652 err = rtrs_post_recv_empty_x2(&con->c, &io_comp_cqe); 653 else 654 err = rtrs_post_recv_empty(&con->c, &io_comp_cqe); 655 if (err) { 656 rtrs_err(con->c.path, "rtrs_post_recv_empty(): %d\n", 657 err); 658 rtrs_rdma_error_recovery(con); 659 } 660 break; 661 case IB_WC_RECV: 662 /* 663 * Key invalidations from server side 664 */ 665 WARN_ON(!(wc->wc_flags & IB_WC_WITH_INVALIDATE || 666 wc->wc_flags & IB_WC_WITH_IMM)); 667 WARN_ON(wc->wr_cqe->done != rtrs_clt_rdma_done); 668 if (clt_path->flags & RTRS_MSG_NEW_RKEY_F) { 669 if (wc->wc_flags & IB_WC_WITH_INVALIDATE) 670 return rtrs_clt_recv_done(con, wc); 671 672 return rtrs_clt_rkey_rsp_done(con, wc); 673 } 674 break; 675 case IB_WC_RDMA_WRITE: 676 /* 677 * post_send() RDMA write completions of IO reqs (read/write) 678 * and hb. 679 */ 680 break; 681 682 default: 683 rtrs_wrn(clt_path->clt, "Unexpected WC type: %d\n", wc->opcode); 684 return; 685 } 686 } 687 688 static int post_recv_io(struct rtrs_clt_con *con, size_t q_size) 689 { 690 int err, i; 691 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path); 692 693 for (i = 0; i < q_size; i++) { 694 if (clt_path->flags & RTRS_MSG_NEW_RKEY_F) { 695 struct rtrs_iu *iu = &con->rsp_ius[i]; 696 697 err = rtrs_iu_post_recv(&con->c, iu); 698 } else { 699 err = rtrs_post_recv_empty(&con->c, &io_comp_cqe); 700 } 701 if (err) 702 return err; 703 } 704 705 return 0; 706 } 707 708 static int post_recv_path(struct rtrs_clt_path *clt_path) 709 { 710 size_t q_size = 0; 711 int err, cid; 712 713 for (cid = 0; cid < clt_path->s.con_num; cid++) { 714 if (cid == 0) 715 q_size = SERVICE_CON_QUEUE_DEPTH; 716 else 717 q_size = clt_path->queue_depth; 718 719 /* 720 * x2 for RDMA read responses + FR key invalidations, 721 * RDMA writes do not require any FR registrations. 722 */ 723 q_size *= 2; 724 725 err = post_recv_io(to_clt_con(clt_path->s.con[cid]), q_size); 726 if (err) { 727 rtrs_err(clt_path->clt, "post_recv_io(), err: %d\n", 728 err); 729 return err; 730 } 731 } 732 733 return 0; 734 } 735 736 struct path_it { 737 int i; 738 struct list_head skip_list; 739 struct rtrs_clt_sess *clt; 740 struct rtrs_clt_path *(*next_path)(struct path_it *it); 741 }; 742 743 /* 744 * rtrs_clt_get_next_path_or_null - get clt path from the list or return NULL 745 * @head: the head for the list. 746 * @clt_path: The element to take the next clt_path from. 747 * 748 * Next clt path returned in round-robin fashion, i.e. head will be skipped, 749 * but if list is observed as empty, NULL will be returned. 750 * 751 * This function may safely run concurrently with the _rcu list-mutation 752 * primitives such as list_add_rcu() as long as it's guarded by rcu_read_lock(). 753 */ 754 static inline struct rtrs_clt_path * 755 rtrs_clt_get_next_path_or_null(struct list_head *head, struct rtrs_clt_path *clt_path) 756 { 757 return list_next_or_null_rcu(head, &clt_path->s.entry, typeof(*clt_path), s.entry) ?: 758 list_next_or_null_rcu(head, 759 READ_ONCE((&clt_path->s.entry)->next), 760 typeof(*clt_path), s.entry); 761 } 762 763 /** 764 * get_next_path_rr() - Returns path in round-robin fashion. 765 * @it: the path pointer 766 * 767 * Related to @MP_POLICY_RR 768 * 769 * Locks: 770 * rcu_read_lock() must be hold. 771 */ 772 static struct rtrs_clt_path *get_next_path_rr(struct path_it *it) 773 { 774 struct rtrs_clt_path __rcu **ppcpu_path; 775 struct rtrs_clt_path *path; 776 struct rtrs_clt_sess *clt; 777 778 clt = it->clt; 779 780 /* 781 * Here we use two RCU objects: @paths_list and @pcpu_path 782 * pointer. See rtrs_clt_remove_path_from_arr() for details 783 * how that is handled. 784 */ 785 786 ppcpu_path = this_cpu_ptr(clt->pcpu_path); 787 path = rcu_dereference(*ppcpu_path); 788 if (!path) 789 path = list_first_or_null_rcu(&clt->paths_list, 790 typeof(*path), s.entry); 791 else 792 path = rtrs_clt_get_next_path_or_null(&clt->paths_list, path); 793 794 rcu_assign_pointer(*ppcpu_path, path); 795 796 return path; 797 } 798 799 /** 800 * get_next_path_min_inflight() - Returns path with minimal inflight count. 801 * @it: the path pointer 802 * 803 * Related to @MP_POLICY_MIN_INFLIGHT 804 * 805 * Locks: 806 * rcu_read_lock() must be hold. 807 */ 808 static struct rtrs_clt_path *get_next_path_min_inflight(struct path_it *it) 809 { 810 struct rtrs_clt_path *min_path = NULL; 811 struct rtrs_clt_sess *clt = it->clt; 812 struct rtrs_clt_path *clt_path; 813 int min_inflight = INT_MAX; 814 int inflight; 815 816 list_for_each_entry_rcu(clt_path, &clt->paths_list, s.entry) { 817 if (READ_ONCE(clt_path->state) != RTRS_CLT_CONNECTED) 818 continue; 819 820 if (!list_empty(raw_cpu_ptr(clt_path->mp_skip_entry))) 821 continue; 822 823 inflight = atomic_read(&clt_path->stats->inflight); 824 825 if (inflight < min_inflight) { 826 min_inflight = inflight; 827 min_path = clt_path; 828 } 829 } 830 831 /* 832 * add the path to the skip list, so that next time we can get 833 * a different one 834 */ 835 if (min_path) 836 list_add(raw_cpu_ptr(min_path->mp_skip_entry), &it->skip_list); 837 838 return min_path; 839 } 840 841 /** 842 * get_next_path_min_latency() - Returns path with minimal latency. 843 * @it: the path pointer 844 * 845 * Return: a path with the lowest latency or NULL if all paths are tried 846 * 847 * Locks: 848 * rcu_read_lock() must be hold. 849 * 850 * Related to @MP_POLICY_MIN_LATENCY 851 * 852 * This DOES skip an already-tried path. 853 * There is a skip-list to skip a path if the path has tried but failed. 854 * It will try the minimum latency path and then the second minimum latency 855 * path and so on. Finally it will return NULL if all paths are tried. 856 * Therefore the caller MUST check the returned 857 * path is NULL and trigger the IO error. 858 */ 859 static struct rtrs_clt_path *get_next_path_min_latency(struct path_it *it) 860 { 861 struct rtrs_clt_path *min_path = NULL; 862 struct rtrs_clt_sess *clt = it->clt; 863 struct rtrs_clt_path *clt_path; 864 ktime_t min_latency = KTIME_MAX; 865 ktime_t latency; 866 867 list_for_each_entry_rcu(clt_path, &clt->paths_list, s.entry) { 868 if (READ_ONCE(clt_path->state) != RTRS_CLT_CONNECTED) 869 continue; 870 871 if (!list_empty(raw_cpu_ptr(clt_path->mp_skip_entry))) 872 continue; 873 874 latency = clt_path->s.hb_cur_latency; 875 876 if (latency < min_latency) { 877 min_latency = latency; 878 min_path = clt_path; 879 } 880 } 881 882 /* 883 * add the path to the skip list, so that next time we can get 884 * a different one 885 */ 886 if (min_path) 887 list_add(raw_cpu_ptr(min_path->mp_skip_entry), &it->skip_list); 888 889 return min_path; 890 } 891 892 static inline void path_it_init(struct path_it *it, struct rtrs_clt_sess *clt) 893 { 894 INIT_LIST_HEAD(&it->skip_list); 895 it->clt = clt; 896 it->i = 0; 897 898 if (clt->mp_policy == MP_POLICY_RR) 899 it->next_path = get_next_path_rr; 900 else if (clt->mp_policy == MP_POLICY_MIN_INFLIGHT) 901 it->next_path = get_next_path_min_inflight; 902 else 903 it->next_path = get_next_path_min_latency; 904 } 905 906 static inline void path_it_deinit(struct path_it *it) 907 { 908 struct list_head *skip, *tmp; 909 /* 910 * The skip_list is used only for the MIN_INFLIGHT and MIN_LATENCY policies. 911 * We need to remove paths from it, so that next IO can insert 912 * paths (->mp_skip_entry) into a skip_list again. 913 */ 914 list_for_each_safe(skip, tmp, &it->skip_list) 915 list_del_init(skip); 916 } 917 918 /** 919 * rtrs_clt_init_req() - Initialize an rtrs_clt_io_req holding information 920 * about an inflight IO. 921 * The user buffer holding user control message (not data) is copied into 922 * the corresponding buffer of rtrs_iu (req->iu->buf), which later on will 923 * also hold the control message of rtrs. 924 * @req: an io request holding information about IO. 925 * @clt_path: client path 926 * @conf: conformation callback function to notify upper layer. 927 * @permit: permit for allocation of RDMA remote buffer 928 * @priv: private pointer 929 * @vec: kernel vector containing control message 930 * @usr_len: length of the user message 931 * @sg: scater list for IO data 932 * @sg_cnt: number of scater list entries 933 * @data_len: length of the IO data 934 * @dir: direction of the IO. 935 */ 936 static void rtrs_clt_init_req(struct rtrs_clt_io_req *req, 937 struct rtrs_clt_path *clt_path, 938 void (*conf)(void *priv, int errno), 939 struct rtrs_permit *permit, void *priv, 940 const struct kvec *vec, size_t usr_len, 941 struct scatterlist *sg, size_t sg_cnt, 942 size_t data_len, int dir) 943 { 944 struct iov_iter iter; 945 size_t len; 946 947 req->permit = permit; 948 req->in_use = true; 949 req->usr_len = usr_len; 950 req->data_len = data_len; 951 req->sglist = sg; 952 req->sg_cnt = sg_cnt; 953 req->priv = priv; 954 req->dir = dir; 955 req->con = rtrs_permit_to_clt_con(clt_path, permit); 956 req->conf = conf; 957 req->need_inv = false; 958 req->need_inv_comp = false; 959 req->inv_errno = 0; 960 refcount_set(&req->ref, 1); 961 req->mp_policy = clt_path->clt->mp_policy; 962 963 iov_iter_kvec(&iter, READ, vec, 1, usr_len); 964 len = _copy_from_iter(req->iu->buf, usr_len, &iter); 965 WARN_ON(len != usr_len); 966 967 reinit_completion(&req->inv_comp); 968 } 969 970 static struct rtrs_clt_io_req * 971 rtrs_clt_get_req(struct rtrs_clt_path *clt_path, 972 void (*conf)(void *priv, int errno), 973 struct rtrs_permit *permit, void *priv, 974 const struct kvec *vec, size_t usr_len, 975 struct scatterlist *sg, size_t sg_cnt, 976 size_t data_len, int dir) 977 { 978 struct rtrs_clt_io_req *req; 979 980 req = &clt_path->reqs[permit->mem_id]; 981 rtrs_clt_init_req(req, clt_path, conf, permit, priv, vec, usr_len, 982 sg, sg_cnt, data_len, dir); 983 return req; 984 } 985 986 static struct rtrs_clt_io_req * 987 rtrs_clt_get_copy_req(struct rtrs_clt_path *alive_path, 988 struct rtrs_clt_io_req *fail_req) 989 { 990 struct rtrs_clt_io_req *req; 991 struct kvec vec = { 992 .iov_base = fail_req->iu->buf, 993 .iov_len = fail_req->usr_len 994 }; 995 996 req = &alive_path->reqs[fail_req->permit->mem_id]; 997 rtrs_clt_init_req(req, alive_path, fail_req->conf, fail_req->permit, 998 fail_req->priv, &vec, fail_req->usr_len, 999 fail_req->sglist, fail_req->sg_cnt, 1000 fail_req->data_len, fail_req->dir); 1001 return req; 1002 } 1003 1004 static int rtrs_post_rdma_write_sg(struct rtrs_clt_con *con, 1005 struct rtrs_clt_io_req *req, 1006 struct rtrs_rbuf *rbuf, bool fr_en, 1007 u32 size, u32 imm, struct ib_send_wr *wr, 1008 struct ib_send_wr *tail) 1009 { 1010 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path); 1011 struct ib_sge *sge = req->sge; 1012 enum ib_send_flags flags; 1013 struct scatterlist *sg; 1014 size_t num_sge; 1015 int i; 1016 struct ib_send_wr *ptail = NULL; 1017 1018 if (fr_en) { 1019 i = 0; 1020 sge[i].addr = req->mr->iova; 1021 sge[i].length = req->mr->length; 1022 sge[i].lkey = req->mr->lkey; 1023 i++; 1024 num_sge = 2; 1025 ptail = tail; 1026 } else { 1027 for_each_sg(req->sglist, sg, req->sg_cnt, i) { 1028 sge[i].addr = sg_dma_address(sg); 1029 sge[i].length = sg_dma_len(sg); 1030 sge[i].lkey = clt_path->s.dev->ib_pd->local_dma_lkey; 1031 } 1032 num_sge = 1 + req->sg_cnt; 1033 } 1034 sge[i].addr = req->iu->dma_addr; 1035 sge[i].length = size; 1036 sge[i].lkey = clt_path->s.dev->ib_pd->local_dma_lkey; 1037 1038 /* 1039 * From time to time we have to post signalled sends, 1040 * or send queue will fill up and only QP reset can help. 1041 */ 1042 flags = atomic_inc_return(&con->c.wr_cnt) % clt_path->s.signal_interval ? 1043 0 : IB_SEND_SIGNALED; 1044 1045 ib_dma_sync_single_for_device(clt_path->s.dev->ib_dev, 1046 req->iu->dma_addr, 1047 size, DMA_TO_DEVICE); 1048 1049 return rtrs_iu_post_rdma_write_imm(&con->c, req->iu, sge, num_sge, 1050 rbuf->rkey, rbuf->addr, imm, 1051 flags, wr, ptail); 1052 } 1053 1054 static int rtrs_map_sg_fr(struct rtrs_clt_io_req *req, size_t count) 1055 { 1056 int nr; 1057 1058 /* Align the MR to a 4K page size to match the block virt boundary */ 1059 nr = ib_map_mr_sg(req->mr, req->sglist, count, NULL, SZ_4K); 1060 if (nr < 0) 1061 return nr; 1062 if (nr < req->sg_cnt) 1063 return -EINVAL; 1064 ib_update_fast_reg_key(req->mr, ib_inc_rkey(req->mr->rkey)); 1065 1066 return nr; 1067 } 1068 1069 static int rtrs_clt_write_req(struct rtrs_clt_io_req *req) 1070 { 1071 struct rtrs_clt_con *con = req->con; 1072 struct rtrs_path *s = con->c.path; 1073 struct rtrs_clt_path *clt_path = to_clt_path(s); 1074 struct rtrs_msg_rdma_write *msg; 1075 1076 struct rtrs_rbuf *rbuf; 1077 int ret, count = 0; 1078 u32 imm, buf_id; 1079 struct ib_reg_wr rwr; 1080 struct ib_send_wr inv_wr; 1081 struct ib_send_wr *wr = NULL; 1082 bool fr_en = false; 1083 1084 const size_t tsize = sizeof(*msg) + req->data_len + req->usr_len; 1085 1086 if (tsize > clt_path->chunk_size) { 1087 rtrs_wrn(s, "Write request failed, size too big %zu > %d\n", 1088 tsize, clt_path->chunk_size); 1089 return -EMSGSIZE; 1090 } 1091 if (req->sg_cnt) { 1092 count = ib_dma_map_sg(clt_path->s.dev->ib_dev, req->sglist, 1093 req->sg_cnt, req->dir); 1094 if (!count) { 1095 rtrs_wrn(s, "Write request failed, map failed\n"); 1096 return -EINVAL; 1097 } 1098 } 1099 /* put rtrs msg after sg and user message */ 1100 msg = req->iu->buf + req->usr_len; 1101 msg->type = cpu_to_le16(RTRS_MSG_WRITE); 1102 msg->usr_len = cpu_to_le16(req->usr_len); 1103 1104 /* rtrs message on server side will be after user data and message */ 1105 imm = req->permit->mem_off + req->data_len + req->usr_len; 1106 imm = rtrs_to_io_req_imm(imm); 1107 buf_id = req->permit->mem_id; 1108 req->sg_size = tsize; 1109 rbuf = &clt_path->rbufs[buf_id]; 1110 1111 if (count) { 1112 ret = rtrs_map_sg_fr(req, count); 1113 if (ret < 0) { 1114 rtrs_err_rl(s, 1115 "Write request failed, failed to map fast reg. data, err: %d\n", 1116 ret); 1117 ib_dma_unmap_sg(clt_path->s.dev->ib_dev, req->sglist, 1118 req->sg_cnt, req->dir); 1119 return ret; 1120 } 1121 inv_wr = (struct ib_send_wr) { 1122 .opcode = IB_WR_LOCAL_INV, 1123 .wr_cqe = &req->inv_cqe, 1124 .send_flags = IB_SEND_SIGNALED, 1125 .ex.invalidate_rkey = req->mr->rkey, 1126 }; 1127 req->inv_cqe.done = rtrs_clt_inv_rkey_done; 1128 rwr = (struct ib_reg_wr) { 1129 .wr.opcode = IB_WR_REG_MR, 1130 .wr.wr_cqe = &fast_reg_cqe, 1131 .mr = req->mr, 1132 .key = req->mr->rkey, 1133 .access = (IB_ACCESS_LOCAL_WRITE), 1134 }; 1135 wr = &rwr.wr; 1136 fr_en = true; 1137 refcount_inc(&req->ref); 1138 } 1139 /* 1140 * Update stats now, after request is successfully sent it is not 1141 * safe anymore to touch it. 1142 */ 1143 rtrs_clt_update_all_stats(req, WRITE); 1144 1145 ret = rtrs_post_rdma_write_sg(req->con, req, rbuf, fr_en, 1146 req->usr_len + sizeof(*msg), 1147 imm, wr, &inv_wr); 1148 if (ret) { 1149 rtrs_err_rl(s, 1150 "Write request failed: error=%d path=%s [%s:%u]\n", 1151 ret, kobject_name(&clt_path->kobj), clt_path->hca_name, 1152 clt_path->hca_port); 1153 if (req->mp_policy == MP_POLICY_MIN_INFLIGHT) 1154 atomic_dec(&clt_path->stats->inflight); 1155 if (req->sg_cnt) 1156 ib_dma_unmap_sg(clt_path->s.dev->ib_dev, req->sglist, 1157 req->sg_cnt, req->dir); 1158 } 1159 1160 return ret; 1161 } 1162 1163 static int rtrs_clt_read_req(struct rtrs_clt_io_req *req) 1164 { 1165 struct rtrs_clt_con *con = req->con; 1166 struct rtrs_path *s = con->c.path; 1167 struct rtrs_clt_path *clt_path = to_clt_path(s); 1168 struct rtrs_msg_rdma_read *msg; 1169 struct rtrs_ib_dev *dev = clt_path->s.dev; 1170 1171 struct ib_reg_wr rwr; 1172 struct ib_send_wr *wr = NULL; 1173 1174 int ret, count = 0; 1175 u32 imm, buf_id; 1176 1177 const size_t tsize = sizeof(*msg) + req->data_len + req->usr_len; 1178 1179 if (tsize > clt_path->chunk_size) { 1180 rtrs_wrn(s, 1181 "Read request failed, message size is %zu, bigger than CHUNK_SIZE %d\n", 1182 tsize, clt_path->chunk_size); 1183 return -EMSGSIZE; 1184 } 1185 1186 if (req->sg_cnt) { 1187 count = ib_dma_map_sg(dev->ib_dev, req->sglist, req->sg_cnt, 1188 req->dir); 1189 if (!count) { 1190 rtrs_wrn(s, 1191 "Read request failed, dma map failed\n"); 1192 return -EINVAL; 1193 } 1194 } 1195 /* put our message into req->buf after user message*/ 1196 msg = req->iu->buf + req->usr_len; 1197 msg->type = cpu_to_le16(RTRS_MSG_READ); 1198 msg->usr_len = cpu_to_le16(req->usr_len); 1199 1200 if (count) { 1201 ret = rtrs_map_sg_fr(req, count); 1202 if (ret < 0) { 1203 rtrs_err_rl(s, 1204 "Read request failed, failed to map fast reg. data, err: %d\n", 1205 ret); 1206 ib_dma_unmap_sg(dev->ib_dev, req->sglist, req->sg_cnt, 1207 req->dir); 1208 return ret; 1209 } 1210 rwr = (struct ib_reg_wr) { 1211 .wr.opcode = IB_WR_REG_MR, 1212 .wr.wr_cqe = &fast_reg_cqe, 1213 .mr = req->mr, 1214 .key = req->mr->rkey, 1215 .access = (IB_ACCESS_LOCAL_WRITE | 1216 IB_ACCESS_REMOTE_WRITE), 1217 }; 1218 wr = &rwr.wr; 1219 1220 msg->sg_cnt = cpu_to_le16(1); 1221 msg->flags = cpu_to_le16(RTRS_MSG_NEED_INVAL_F); 1222 1223 msg->desc[0].addr = cpu_to_le64(req->mr->iova); 1224 msg->desc[0].key = cpu_to_le32(req->mr->rkey); 1225 msg->desc[0].len = cpu_to_le32(req->mr->length); 1226 1227 /* Further invalidation is required */ 1228 req->need_inv = !!RTRS_MSG_NEED_INVAL_F; 1229 1230 } else { 1231 msg->sg_cnt = 0; 1232 msg->flags = 0; 1233 } 1234 /* 1235 * rtrs message will be after the space reserved for disk data and 1236 * user message 1237 */ 1238 imm = req->permit->mem_off + req->data_len + req->usr_len; 1239 imm = rtrs_to_io_req_imm(imm); 1240 buf_id = req->permit->mem_id; 1241 1242 req->sg_size = sizeof(*msg); 1243 req->sg_size += le16_to_cpu(msg->sg_cnt) * sizeof(struct rtrs_sg_desc); 1244 req->sg_size += req->usr_len; 1245 1246 /* 1247 * Update stats now, after request is successfully sent it is not 1248 * safe anymore to touch it. 1249 */ 1250 rtrs_clt_update_all_stats(req, READ); 1251 1252 ret = rtrs_post_send_rdma(req->con, req, &clt_path->rbufs[buf_id], 1253 req->data_len, imm, wr); 1254 if (ret) { 1255 rtrs_err_rl(s, 1256 "Read request failed: error=%d path=%s [%s:%u]\n", 1257 ret, kobject_name(&clt_path->kobj), clt_path->hca_name, 1258 clt_path->hca_port); 1259 if (req->mp_policy == MP_POLICY_MIN_INFLIGHT) 1260 atomic_dec(&clt_path->stats->inflight); 1261 req->need_inv = false; 1262 if (req->sg_cnt) 1263 ib_dma_unmap_sg(dev->ib_dev, req->sglist, 1264 req->sg_cnt, req->dir); 1265 } 1266 1267 return ret; 1268 } 1269 1270 /** 1271 * rtrs_clt_failover_req() - Try to find an active path for a failed request 1272 * @clt: clt context 1273 * @fail_req: a failed io request. 1274 */ 1275 static int rtrs_clt_failover_req(struct rtrs_clt_sess *clt, 1276 struct rtrs_clt_io_req *fail_req) 1277 { 1278 struct rtrs_clt_path *alive_path; 1279 struct rtrs_clt_io_req *req; 1280 int err = -ECONNABORTED; 1281 struct path_it it; 1282 1283 rcu_read_lock(); 1284 for (path_it_init(&it, clt); 1285 (alive_path = it.next_path(&it)) && it.i < it.clt->paths_num; 1286 it.i++) { 1287 if (READ_ONCE(alive_path->state) != RTRS_CLT_CONNECTED) 1288 continue; 1289 req = rtrs_clt_get_copy_req(alive_path, fail_req); 1290 if (req->dir == DMA_TO_DEVICE) 1291 err = rtrs_clt_write_req(req); 1292 else 1293 err = rtrs_clt_read_req(req); 1294 if (err) { 1295 req->in_use = false; 1296 continue; 1297 } 1298 /* Success path */ 1299 rtrs_clt_inc_failover_cnt(alive_path->stats); 1300 break; 1301 } 1302 path_it_deinit(&it); 1303 rcu_read_unlock(); 1304 1305 return err; 1306 } 1307 1308 static void fail_all_outstanding_reqs(struct rtrs_clt_path *clt_path) 1309 { 1310 struct rtrs_clt_sess *clt = clt_path->clt; 1311 struct rtrs_clt_io_req *req; 1312 int i, err; 1313 1314 if (!clt_path->reqs) 1315 return; 1316 for (i = 0; i < clt_path->queue_depth; ++i) { 1317 req = &clt_path->reqs[i]; 1318 if (!req->in_use) 1319 continue; 1320 1321 /* 1322 * Safely (without notification) complete failed request. 1323 * After completion this request is still useble and can 1324 * be failovered to another path. 1325 */ 1326 complete_rdma_req(req, -ECONNABORTED, false, true); 1327 1328 err = rtrs_clt_failover_req(clt, req); 1329 if (err) 1330 /* Failover failed, notify anyway */ 1331 req->conf(req->priv, err); 1332 } 1333 } 1334 1335 static void free_path_reqs(struct rtrs_clt_path *clt_path) 1336 { 1337 struct rtrs_clt_io_req *req; 1338 int i; 1339 1340 if (!clt_path->reqs) 1341 return; 1342 for (i = 0; i < clt_path->queue_depth; ++i) { 1343 req = &clt_path->reqs[i]; 1344 if (req->mr) 1345 ib_dereg_mr(req->mr); 1346 kfree(req->sge); 1347 rtrs_iu_free(req->iu, clt_path->s.dev->ib_dev, 1); 1348 } 1349 kfree(clt_path->reqs); 1350 clt_path->reqs = NULL; 1351 } 1352 1353 static int alloc_path_reqs(struct rtrs_clt_path *clt_path) 1354 { 1355 struct rtrs_clt_io_req *req; 1356 int i, err = -ENOMEM; 1357 1358 clt_path->reqs = kcalloc(clt_path->queue_depth, 1359 sizeof(*clt_path->reqs), 1360 GFP_KERNEL); 1361 if (!clt_path->reqs) 1362 return -ENOMEM; 1363 1364 for (i = 0; i < clt_path->queue_depth; ++i) { 1365 req = &clt_path->reqs[i]; 1366 req->iu = rtrs_iu_alloc(1, clt_path->max_hdr_size, GFP_KERNEL, 1367 clt_path->s.dev->ib_dev, 1368 DMA_TO_DEVICE, 1369 rtrs_clt_rdma_done); 1370 if (!req->iu) 1371 goto out; 1372 1373 req->sge = kcalloc(2, sizeof(*req->sge), GFP_KERNEL); 1374 if (!req->sge) 1375 goto out; 1376 1377 req->mr = ib_alloc_mr(clt_path->s.dev->ib_pd, 1378 IB_MR_TYPE_MEM_REG, 1379 clt_path->max_pages_per_mr); 1380 if (IS_ERR(req->mr)) { 1381 err = PTR_ERR(req->mr); 1382 req->mr = NULL; 1383 pr_err("Failed to alloc clt_path->max_pages_per_mr %d\n", 1384 clt_path->max_pages_per_mr); 1385 goto out; 1386 } 1387 1388 init_completion(&req->inv_comp); 1389 } 1390 1391 return 0; 1392 1393 out: 1394 free_path_reqs(clt_path); 1395 1396 return err; 1397 } 1398 1399 static int alloc_permits(struct rtrs_clt_sess *clt) 1400 { 1401 unsigned int chunk_bits; 1402 int err, i; 1403 1404 clt->permits_map = bitmap_zalloc(clt->queue_depth, GFP_KERNEL); 1405 if (!clt->permits_map) { 1406 err = -ENOMEM; 1407 goto out_err; 1408 } 1409 clt->permits = kcalloc(clt->queue_depth, permit_size(clt), GFP_KERNEL); 1410 if (!clt->permits) { 1411 err = -ENOMEM; 1412 goto err_map; 1413 } 1414 chunk_bits = ilog2(clt->queue_depth - 1) + 1; 1415 for (i = 0; i < clt->queue_depth; i++) { 1416 struct rtrs_permit *permit; 1417 1418 permit = get_permit(clt, i); 1419 permit->mem_id = i; 1420 permit->mem_off = i << (MAX_IMM_PAYL_BITS - chunk_bits); 1421 } 1422 1423 return 0; 1424 1425 err_map: 1426 bitmap_free(clt->permits_map); 1427 clt->permits_map = NULL; 1428 out_err: 1429 return err; 1430 } 1431 1432 static void free_permits(struct rtrs_clt_sess *clt) 1433 { 1434 if (clt->permits_map) 1435 wait_event(clt->permits_wait, 1436 bitmap_empty(clt->permits_map, clt->queue_depth)); 1437 1438 bitmap_free(clt->permits_map); 1439 clt->permits_map = NULL; 1440 kfree(clt->permits); 1441 clt->permits = NULL; 1442 } 1443 1444 static void query_fast_reg_mode(struct rtrs_clt_path *clt_path) 1445 { 1446 struct ib_device *ib_dev; 1447 u64 max_pages_per_mr; 1448 int mr_page_shift; 1449 1450 ib_dev = clt_path->s.dev->ib_dev; 1451 1452 /* 1453 * Use the smallest page size supported by the HCA, down to a 1454 * minimum of 4096 bytes. We're unlikely to build large sglists 1455 * out of smaller entries. 1456 */ 1457 mr_page_shift = max(12, ffs(ib_dev->attrs.page_size_cap) - 1); 1458 max_pages_per_mr = ib_dev->attrs.max_mr_size; 1459 do_div(max_pages_per_mr, (1ull << mr_page_shift)); 1460 clt_path->max_pages_per_mr = 1461 min3(clt_path->max_pages_per_mr, (u32)max_pages_per_mr, 1462 ib_dev->attrs.max_fast_reg_page_list_len); 1463 clt_path->clt->max_segments = 1464 min(clt_path->max_pages_per_mr, clt_path->clt->max_segments); 1465 } 1466 1467 static bool rtrs_clt_change_state_get_old(struct rtrs_clt_path *clt_path, 1468 enum rtrs_clt_state new_state, 1469 enum rtrs_clt_state *old_state) 1470 { 1471 bool changed; 1472 1473 spin_lock_irq(&clt_path->state_wq.lock); 1474 if (old_state) 1475 *old_state = clt_path->state; 1476 changed = rtrs_clt_change_state(clt_path, new_state); 1477 spin_unlock_irq(&clt_path->state_wq.lock); 1478 1479 return changed; 1480 } 1481 1482 static void rtrs_clt_hb_err_handler(struct rtrs_con *c) 1483 { 1484 struct rtrs_clt_con *con = container_of(c, typeof(*con), c); 1485 1486 rtrs_rdma_error_recovery(con); 1487 } 1488 1489 static void rtrs_clt_init_hb(struct rtrs_clt_path *clt_path) 1490 { 1491 rtrs_init_hb(&clt_path->s, &io_comp_cqe, 1492 RTRS_HB_INTERVAL_MS, 1493 RTRS_HB_MISSED_MAX, 1494 rtrs_clt_hb_err_handler, 1495 rtrs_wq); 1496 } 1497 1498 static void rtrs_clt_reconnect_work(struct work_struct *work); 1499 static void rtrs_clt_close_work(struct work_struct *work); 1500 1501 static void rtrs_clt_err_recovery_work(struct work_struct *work) 1502 { 1503 struct rtrs_clt_path *clt_path; 1504 struct rtrs_clt_sess *clt; 1505 int delay_ms; 1506 1507 clt_path = container_of(work, struct rtrs_clt_path, err_recovery_work); 1508 clt = clt_path->clt; 1509 delay_ms = clt->reconnect_delay_sec * 1000; 1510 rtrs_clt_stop_and_destroy_conns(clt_path); 1511 queue_delayed_work(rtrs_wq, &clt_path->reconnect_dwork, 1512 msecs_to_jiffies(delay_ms + 1513 prandom_u32() % 1514 RTRS_RECONNECT_SEED)); 1515 } 1516 1517 static struct rtrs_clt_path *alloc_path(struct rtrs_clt_sess *clt, 1518 const struct rtrs_addr *path, 1519 size_t con_num, u32 nr_poll_queues) 1520 { 1521 struct rtrs_clt_path *clt_path; 1522 int err = -ENOMEM; 1523 int cpu; 1524 size_t total_con; 1525 1526 clt_path = kzalloc(sizeof(*clt_path), GFP_KERNEL); 1527 if (!clt_path) 1528 goto err; 1529 1530 /* 1531 * irqmode and poll 1532 * +1: Extra connection for user messages 1533 */ 1534 total_con = con_num + nr_poll_queues + 1; 1535 clt_path->s.con = kcalloc(total_con, sizeof(*clt_path->s.con), 1536 GFP_KERNEL); 1537 if (!clt_path->s.con) 1538 goto err_free_path; 1539 1540 clt_path->s.con_num = total_con; 1541 clt_path->s.irq_con_num = con_num + 1; 1542 1543 clt_path->stats = kzalloc(sizeof(*clt_path->stats), GFP_KERNEL); 1544 if (!clt_path->stats) 1545 goto err_free_con; 1546 1547 mutex_init(&clt_path->init_mutex); 1548 uuid_gen(&clt_path->s.uuid); 1549 memcpy(&clt_path->s.dst_addr, path->dst, 1550 rdma_addr_size((struct sockaddr *)path->dst)); 1551 1552 /* 1553 * rdma_resolve_addr() passes src_addr to cma_bind_addr, which 1554 * checks the sa_family to be non-zero. If user passed src_addr=NULL 1555 * the sess->src_addr will contain only zeros, which is then fine. 1556 */ 1557 if (path->src) 1558 memcpy(&clt_path->s.src_addr, path->src, 1559 rdma_addr_size((struct sockaddr *)path->src)); 1560 strscpy(clt_path->s.sessname, clt->sessname, 1561 sizeof(clt_path->s.sessname)); 1562 clt_path->clt = clt; 1563 clt_path->max_pages_per_mr = RTRS_MAX_SEGMENTS; 1564 init_waitqueue_head(&clt_path->state_wq); 1565 clt_path->state = RTRS_CLT_CONNECTING; 1566 atomic_set(&clt_path->connected_cnt, 0); 1567 INIT_WORK(&clt_path->close_work, rtrs_clt_close_work); 1568 INIT_WORK(&clt_path->err_recovery_work, rtrs_clt_err_recovery_work); 1569 INIT_DELAYED_WORK(&clt_path->reconnect_dwork, rtrs_clt_reconnect_work); 1570 rtrs_clt_init_hb(clt_path); 1571 1572 clt_path->mp_skip_entry = alloc_percpu(typeof(*clt_path->mp_skip_entry)); 1573 if (!clt_path->mp_skip_entry) 1574 goto err_free_stats; 1575 1576 for_each_possible_cpu(cpu) 1577 INIT_LIST_HEAD(per_cpu_ptr(clt_path->mp_skip_entry, cpu)); 1578 1579 err = rtrs_clt_init_stats(clt_path->stats); 1580 if (err) 1581 goto err_free_percpu; 1582 1583 return clt_path; 1584 1585 err_free_percpu: 1586 free_percpu(clt_path->mp_skip_entry); 1587 err_free_stats: 1588 kfree(clt_path->stats); 1589 err_free_con: 1590 kfree(clt_path->s.con); 1591 err_free_path: 1592 kfree(clt_path); 1593 err: 1594 return ERR_PTR(err); 1595 } 1596 1597 void free_path(struct rtrs_clt_path *clt_path) 1598 { 1599 free_percpu(clt_path->mp_skip_entry); 1600 mutex_destroy(&clt_path->init_mutex); 1601 kfree(clt_path->s.con); 1602 kfree(clt_path->rbufs); 1603 kfree(clt_path); 1604 } 1605 1606 static int create_con(struct rtrs_clt_path *clt_path, unsigned int cid) 1607 { 1608 struct rtrs_clt_con *con; 1609 1610 con = kzalloc(sizeof(*con), GFP_KERNEL); 1611 if (!con) 1612 return -ENOMEM; 1613 1614 /* Map first two connections to the first CPU */ 1615 con->cpu = (cid ? cid - 1 : 0) % nr_cpu_ids; 1616 con->c.cid = cid; 1617 con->c.path = &clt_path->s; 1618 /* Align with srv, init as 1 */ 1619 atomic_set(&con->c.wr_cnt, 1); 1620 mutex_init(&con->con_mutex); 1621 1622 clt_path->s.con[cid] = &con->c; 1623 1624 return 0; 1625 } 1626 1627 static void destroy_con(struct rtrs_clt_con *con) 1628 { 1629 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path); 1630 1631 clt_path->s.con[con->c.cid] = NULL; 1632 mutex_destroy(&con->con_mutex); 1633 kfree(con); 1634 } 1635 1636 static int create_con_cq_qp(struct rtrs_clt_con *con) 1637 { 1638 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path); 1639 u32 max_send_wr, max_recv_wr, cq_num, max_send_sge, wr_limit; 1640 int err, cq_vector; 1641 struct rtrs_msg_rkey_rsp *rsp; 1642 1643 lockdep_assert_held(&con->con_mutex); 1644 if (con->c.cid == 0) { 1645 max_send_sge = 1; 1646 /* We must be the first here */ 1647 if (WARN_ON(clt_path->s.dev)) 1648 return -EINVAL; 1649 1650 /* 1651 * The whole session uses device from user connection. 1652 * Be careful not to close user connection before ib dev 1653 * is gracefully put. 1654 */ 1655 clt_path->s.dev = rtrs_ib_dev_find_or_add(con->c.cm_id->device, 1656 &dev_pd); 1657 if (!clt_path->s.dev) { 1658 rtrs_wrn(clt_path->clt, 1659 "rtrs_ib_dev_find_get_or_add(): no memory\n"); 1660 return -ENOMEM; 1661 } 1662 clt_path->s.dev_ref = 1; 1663 query_fast_reg_mode(clt_path); 1664 wr_limit = clt_path->s.dev->ib_dev->attrs.max_qp_wr; 1665 /* 1666 * Two (request + registration) completion for send 1667 * Two for recv if always_invalidate is set on server 1668 * or one for recv. 1669 * + 2 for drain and heartbeat 1670 * in case qp gets into error state. 1671 */ 1672 max_send_wr = 1673 min_t(int, wr_limit, SERVICE_CON_QUEUE_DEPTH * 2 + 2); 1674 max_recv_wr = max_send_wr; 1675 } else { 1676 /* 1677 * Here we assume that session members are correctly set. 1678 * This is always true if user connection (cid == 0) is 1679 * established first. 1680 */ 1681 if (WARN_ON(!clt_path->s.dev)) 1682 return -EINVAL; 1683 if (WARN_ON(!clt_path->queue_depth)) 1684 return -EINVAL; 1685 1686 wr_limit = clt_path->s.dev->ib_dev->attrs.max_qp_wr; 1687 /* Shared between connections */ 1688 clt_path->s.dev_ref++; 1689 max_send_wr = min_t(int, wr_limit, 1690 /* QD * (REQ + RSP + FR REGS or INVS) + drain */ 1691 clt_path->queue_depth * 3 + 1); 1692 max_recv_wr = min_t(int, wr_limit, 1693 clt_path->queue_depth * 3 + 1); 1694 max_send_sge = 2; 1695 } 1696 atomic_set(&con->c.sq_wr_avail, max_send_wr); 1697 cq_num = max_send_wr + max_recv_wr; 1698 /* alloc iu to recv new rkey reply when server reports flags set */ 1699 if (clt_path->flags & RTRS_MSG_NEW_RKEY_F || con->c.cid == 0) { 1700 con->rsp_ius = rtrs_iu_alloc(cq_num, sizeof(*rsp), 1701 GFP_KERNEL, 1702 clt_path->s.dev->ib_dev, 1703 DMA_FROM_DEVICE, 1704 rtrs_clt_rdma_done); 1705 if (!con->rsp_ius) 1706 return -ENOMEM; 1707 con->queue_num = cq_num; 1708 } 1709 cq_num = max_send_wr + max_recv_wr; 1710 cq_vector = con->cpu % clt_path->s.dev->ib_dev->num_comp_vectors; 1711 if (con->c.cid >= clt_path->s.irq_con_num) 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_DIRECT); 1715 else 1716 err = rtrs_cq_qp_create(&clt_path->s, &con->c, max_send_sge, 1717 cq_vector, cq_num, max_send_wr, 1718 max_recv_wr, IB_POLL_SOFTIRQ); 1719 /* 1720 * In case of error we do not bother to clean previous allocations, 1721 * since destroy_con_cq_qp() must be called. 1722 */ 1723 return err; 1724 } 1725 1726 static void destroy_con_cq_qp(struct rtrs_clt_con *con) 1727 { 1728 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path); 1729 1730 /* 1731 * Be careful here: destroy_con_cq_qp() can be called even 1732 * create_con_cq_qp() failed, see comments there. 1733 */ 1734 lockdep_assert_held(&con->con_mutex); 1735 rtrs_cq_qp_destroy(&con->c); 1736 if (con->rsp_ius) { 1737 rtrs_iu_free(con->rsp_ius, clt_path->s.dev->ib_dev, 1738 con->queue_num); 1739 con->rsp_ius = NULL; 1740 con->queue_num = 0; 1741 } 1742 if (clt_path->s.dev_ref && !--clt_path->s.dev_ref) { 1743 rtrs_ib_dev_put(clt_path->s.dev); 1744 clt_path->s.dev = NULL; 1745 } 1746 } 1747 1748 static void stop_cm(struct rtrs_clt_con *con) 1749 { 1750 rdma_disconnect(con->c.cm_id); 1751 if (con->c.qp) 1752 ib_drain_qp(con->c.qp); 1753 } 1754 1755 static void destroy_cm(struct rtrs_clt_con *con) 1756 { 1757 rdma_destroy_id(con->c.cm_id); 1758 con->c.cm_id = NULL; 1759 } 1760 1761 static int rtrs_rdma_addr_resolved(struct rtrs_clt_con *con) 1762 { 1763 struct rtrs_path *s = con->c.path; 1764 int err; 1765 1766 mutex_lock(&con->con_mutex); 1767 err = create_con_cq_qp(con); 1768 mutex_unlock(&con->con_mutex); 1769 if (err) { 1770 rtrs_err(s, "create_con_cq_qp(), err: %d\n", err); 1771 return err; 1772 } 1773 err = rdma_resolve_route(con->c.cm_id, RTRS_CONNECT_TIMEOUT_MS); 1774 if (err) 1775 rtrs_err(s, "Resolving route failed, err: %d\n", err); 1776 1777 return err; 1778 } 1779 1780 static int rtrs_rdma_route_resolved(struct rtrs_clt_con *con) 1781 { 1782 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path); 1783 struct rtrs_clt_sess *clt = clt_path->clt; 1784 struct rtrs_msg_conn_req msg; 1785 struct rdma_conn_param param; 1786 1787 int err; 1788 1789 param = (struct rdma_conn_param) { 1790 .retry_count = 7, 1791 .rnr_retry_count = 7, 1792 .private_data = &msg, 1793 .private_data_len = sizeof(msg), 1794 }; 1795 1796 msg = (struct rtrs_msg_conn_req) { 1797 .magic = cpu_to_le16(RTRS_MAGIC), 1798 .version = cpu_to_le16(RTRS_PROTO_VER), 1799 .cid = cpu_to_le16(con->c.cid), 1800 .cid_num = cpu_to_le16(clt_path->s.con_num), 1801 .recon_cnt = cpu_to_le16(clt_path->s.recon_cnt), 1802 }; 1803 msg.first_conn = clt_path->for_new_clt ? FIRST_CONN : 0; 1804 uuid_copy(&msg.sess_uuid, &clt_path->s.uuid); 1805 uuid_copy(&msg.paths_uuid, &clt->paths_uuid); 1806 1807 err = rdma_connect_locked(con->c.cm_id, ¶m); 1808 if (err) 1809 rtrs_err(clt, "rdma_connect_locked(): %d\n", err); 1810 1811 return err; 1812 } 1813 1814 static int rtrs_rdma_conn_established(struct rtrs_clt_con *con, 1815 struct rdma_cm_event *ev) 1816 { 1817 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path); 1818 struct rtrs_clt_sess *clt = clt_path->clt; 1819 const struct rtrs_msg_conn_rsp *msg; 1820 u16 version, queue_depth; 1821 int errno; 1822 u8 len; 1823 1824 msg = ev->param.conn.private_data; 1825 len = ev->param.conn.private_data_len; 1826 if (len < sizeof(*msg)) { 1827 rtrs_err(clt, "Invalid RTRS connection response\n"); 1828 return -ECONNRESET; 1829 } 1830 if (le16_to_cpu(msg->magic) != RTRS_MAGIC) { 1831 rtrs_err(clt, "Invalid RTRS magic\n"); 1832 return -ECONNRESET; 1833 } 1834 version = le16_to_cpu(msg->version); 1835 if (version >> 8 != RTRS_PROTO_VER_MAJOR) { 1836 rtrs_err(clt, "Unsupported major RTRS version: %d, expected %d\n", 1837 version >> 8, RTRS_PROTO_VER_MAJOR); 1838 return -ECONNRESET; 1839 } 1840 errno = le16_to_cpu(msg->errno); 1841 if (errno) { 1842 rtrs_err(clt, "Invalid RTRS message: errno %d\n", 1843 errno); 1844 return -ECONNRESET; 1845 } 1846 if (con->c.cid == 0) { 1847 queue_depth = le16_to_cpu(msg->queue_depth); 1848 1849 if (clt_path->queue_depth > 0 && queue_depth != clt_path->queue_depth) { 1850 rtrs_err(clt, "Error: queue depth changed\n"); 1851 1852 /* 1853 * Stop any more reconnection attempts 1854 */ 1855 clt_path->reconnect_attempts = -1; 1856 rtrs_err(clt, 1857 "Disabling auto-reconnect. Trigger a manual reconnect after issue is resolved\n"); 1858 return -ECONNRESET; 1859 } 1860 1861 if (!clt_path->rbufs) { 1862 clt_path->rbufs = kcalloc(queue_depth, 1863 sizeof(*clt_path->rbufs), 1864 GFP_KERNEL); 1865 if (!clt_path->rbufs) 1866 return -ENOMEM; 1867 } 1868 clt_path->queue_depth = queue_depth; 1869 clt_path->s.signal_interval = min_not_zero(queue_depth, 1870 (unsigned short) SERVICE_CON_QUEUE_DEPTH); 1871 clt_path->max_hdr_size = le32_to_cpu(msg->max_hdr_size); 1872 clt_path->max_io_size = le32_to_cpu(msg->max_io_size); 1873 clt_path->flags = le32_to_cpu(msg->flags); 1874 clt_path->chunk_size = clt_path->max_io_size + clt_path->max_hdr_size; 1875 1876 /* 1877 * Global IO size is always a minimum. 1878 * If while a reconnection server sends us a value a bit 1879 * higher - client does not care and uses cached minimum. 1880 * 1881 * Since we can have several sessions (paths) restablishing 1882 * connections in parallel, use lock. 1883 */ 1884 mutex_lock(&clt->paths_mutex); 1885 clt->queue_depth = clt_path->queue_depth; 1886 clt->max_io_size = min_not_zero(clt_path->max_io_size, 1887 clt->max_io_size); 1888 mutex_unlock(&clt->paths_mutex); 1889 1890 /* 1891 * Cache the hca_port and hca_name for sysfs 1892 */ 1893 clt_path->hca_port = con->c.cm_id->port_num; 1894 scnprintf(clt_path->hca_name, sizeof(clt_path->hca_name), 1895 clt_path->s.dev->ib_dev->name); 1896 clt_path->s.src_addr = con->c.cm_id->route.addr.src_addr; 1897 /* set for_new_clt, to allow future reconnect on any path */ 1898 clt_path->for_new_clt = 1; 1899 } 1900 1901 return 0; 1902 } 1903 1904 static inline void flag_success_on_conn(struct rtrs_clt_con *con) 1905 { 1906 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path); 1907 1908 atomic_inc(&clt_path->connected_cnt); 1909 con->cm_err = 1; 1910 } 1911 1912 static int rtrs_rdma_conn_rejected(struct rtrs_clt_con *con, 1913 struct rdma_cm_event *ev) 1914 { 1915 struct rtrs_path *s = con->c.path; 1916 const struct rtrs_msg_conn_rsp *msg; 1917 const char *rej_msg; 1918 int status, errno; 1919 u8 data_len; 1920 1921 status = ev->status; 1922 rej_msg = rdma_reject_msg(con->c.cm_id, status); 1923 msg = rdma_consumer_reject_data(con->c.cm_id, ev, &data_len); 1924 1925 if (msg && data_len >= sizeof(*msg)) { 1926 errno = (int16_t)le16_to_cpu(msg->errno); 1927 if (errno == -EBUSY) 1928 rtrs_err(s, 1929 "Previous session is still exists on the server, please reconnect later\n"); 1930 else 1931 rtrs_err(s, 1932 "Connect rejected: status %d (%s), rtrs errno %d\n", 1933 status, rej_msg, errno); 1934 } else { 1935 rtrs_err(s, 1936 "Connect rejected but with malformed message: status %d (%s)\n", 1937 status, rej_msg); 1938 } 1939 1940 return -ECONNRESET; 1941 } 1942 1943 void rtrs_clt_close_conns(struct rtrs_clt_path *clt_path, bool wait) 1944 { 1945 if (rtrs_clt_change_state_get_old(clt_path, RTRS_CLT_CLOSING, NULL)) 1946 queue_work(rtrs_wq, &clt_path->close_work); 1947 if (wait) 1948 flush_work(&clt_path->close_work); 1949 } 1950 1951 static inline void flag_error_on_conn(struct rtrs_clt_con *con, int cm_err) 1952 { 1953 if (con->cm_err == 1) { 1954 struct rtrs_clt_path *clt_path; 1955 1956 clt_path = to_clt_path(con->c.path); 1957 if (atomic_dec_and_test(&clt_path->connected_cnt)) 1958 1959 wake_up(&clt_path->state_wq); 1960 } 1961 con->cm_err = cm_err; 1962 } 1963 1964 static int rtrs_clt_rdma_cm_handler(struct rdma_cm_id *cm_id, 1965 struct rdma_cm_event *ev) 1966 { 1967 struct rtrs_clt_con *con = cm_id->context; 1968 struct rtrs_path *s = con->c.path; 1969 struct rtrs_clt_path *clt_path = to_clt_path(s); 1970 int cm_err = 0; 1971 1972 switch (ev->event) { 1973 case RDMA_CM_EVENT_ADDR_RESOLVED: 1974 cm_err = rtrs_rdma_addr_resolved(con); 1975 break; 1976 case RDMA_CM_EVENT_ROUTE_RESOLVED: 1977 cm_err = rtrs_rdma_route_resolved(con); 1978 break; 1979 case RDMA_CM_EVENT_ESTABLISHED: 1980 cm_err = rtrs_rdma_conn_established(con, ev); 1981 if (!cm_err) { 1982 /* 1983 * Report success and wake up. Here we abuse state_wq, 1984 * i.e. wake up without state change, but we set cm_err. 1985 */ 1986 flag_success_on_conn(con); 1987 wake_up(&clt_path->state_wq); 1988 return 0; 1989 } 1990 break; 1991 case RDMA_CM_EVENT_REJECTED: 1992 cm_err = rtrs_rdma_conn_rejected(con, ev); 1993 break; 1994 case RDMA_CM_EVENT_DISCONNECTED: 1995 /* No message for disconnecting */ 1996 cm_err = -ECONNRESET; 1997 break; 1998 case RDMA_CM_EVENT_CONNECT_ERROR: 1999 case RDMA_CM_EVENT_UNREACHABLE: 2000 case RDMA_CM_EVENT_ADDR_CHANGE: 2001 case RDMA_CM_EVENT_TIMEWAIT_EXIT: 2002 rtrs_wrn(s, "CM error (CM event: %s, err: %d)\n", 2003 rdma_event_msg(ev->event), ev->status); 2004 cm_err = -ECONNRESET; 2005 break; 2006 case RDMA_CM_EVENT_ADDR_ERROR: 2007 case RDMA_CM_EVENT_ROUTE_ERROR: 2008 rtrs_wrn(s, "CM error (CM event: %s, err: %d)\n", 2009 rdma_event_msg(ev->event), ev->status); 2010 cm_err = -EHOSTUNREACH; 2011 break; 2012 case RDMA_CM_EVENT_DEVICE_REMOVAL: 2013 /* 2014 * Device removal is a special case. Queue close and return 0. 2015 */ 2016 rtrs_clt_close_conns(clt_path, false); 2017 return 0; 2018 default: 2019 rtrs_err(s, "Unexpected RDMA CM error (CM event: %s, err: %d)\n", 2020 rdma_event_msg(ev->event), ev->status); 2021 cm_err = -ECONNRESET; 2022 break; 2023 } 2024 2025 if (cm_err) { 2026 /* 2027 * cm error makes sense only on connection establishing, 2028 * in other cases we rely on normal procedure of reconnecting. 2029 */ 2030 flag_error_on_conn(con, cm_err); 2031 rtrs_rdma_error_recovery(con); 2032 } 2033 2034 return 0; 2035 } 2036 2037 static int create_cm(struct rtrs_clt_con *con) 2038 { 2039 struct rtrs_path *s = con->c.path; 2040 struct rtrs_clt_path *clt_path = to_clt_path(s); 2041 struct rdma_cm_id *cm_id; 2042 int err; 2043 2044 cm_id = rdma_create_id(&init_net, rtrs_clt_rdma_cm_handler, con, 2045 clt_path->s.dst_addr.ss_family == AF_IB ? 2046 RDMA_PS_IB : RDMA_PS_TCP, IB_QPT_RC); 2047 if (IS_ERR(cm_id)) { 2048 err = PTR_ERR(cm_id); 2049 rtrs_err(s, "Failed to create CM ID, err: %d\n", err); 2050 2051 return err; 2052 } 2053 con->c.cm_id = cm_id; 2054 con->cm_err = 0; 2055 /* allow the port to be reused */ 2056 err = rdma_set_reuseaddr(cm_id, 1); 2057 if (err != 0) { 2058 rtrs_err(s, "Set address reuse failed, err: %d\n", err); 2059 goto destroy_cm; 2060 } 2061 err = rdma_resolve_addr(cm_id, (struct sockaddr *)&clt_path->s.src_addr, 2062 (struct sockaddr *)&clt_path->s.dst_addr, 2063 RTRS_CONNECT_TIMEOUT_MS); 2064 if (err) { 2065 rtrs_err(s, "Failed to resolve address, err: %d\n", err); 2066 goto destroy_cm; 2067 } 2068 /* 2069 * Combine connection status and session events. This is needed 2070 * for waiting two possible cases: cm_err has something meaningful 2071 * or session state was really changed to error by device removal. 2072 */ 2073 err = wait_event_interruptible_timeout( 2074 clt_path->state_wq, 2075 con->cm_err || clt_path->state != RTRS_CLT_CONNECTING, 2076 msecs_to_jiffies(RTRS_CONNECT_TIMEOUT_MS)); 2077 if (err == 0 || err == -ERESTARTSYS) { 2078 if (err == 0) 2079 err = -ETIMEDOUT; 2080 /* Timedout or interrupted */ 2081 goto errr; 2082 } 2083 if (con->cm_err < 0) { 2084 err = con->cm_err; 2085 goto errr; 2086 } 2087 if (READ_ONCE(clt_path->state) != RTRS_CLT_CONNECTING) { 2088 /* Device removal */ 2089 err = -ECONNABORTED; 2090 goto errr; 2091 } 2092 2093 return 0; 2094 2095 errr: 2096 stop_cm(con); 2097 mutex_lock(&con->con_mutex); 2098 destroy_con_cq_qp(con); 2099 mutex_unlock(&con->con_mutex); 2100 destroy_cm: 2101 destroy_cm(con); 2102 2103 return err; 2104 } 2105 2106 static void rtrs_clt_path_up(struct rtrs_clt_path *clt_path) 2107 { 2108 struct rtrs_clt_sess *clt = clt_path->clt; 2109 int up; 2110 2111 /* 2112 * We can fire RECONNECTED event only when all paths were 2113 * connected on rtrs_clt_open(), then each was disconnected 2114 * and the first one connected again. That's why this nasty 2115 * game with counter value. 2116 */ 2117 2118 mutex_lock(&clt->paths_ev_mutex); 2119 up = ++clt->paths_up; 2120 /* 2121 * Here it is safe to access paths num directly since up counter 2122 * is greater than MAX_PATHS_NUM only while rtrs_clt_open() is 2123 * in progress, thus paths removals are impossible. 2124 */ 2125 if (up > MAX_PATHS_NUM && up == MAX_PATHS_NUM + clt->paths_num) 2126 clt->paths_up = clt->paths_num; 2127 else if (up == 1) 2128 clt->link_ev(clt->priv, RTRS_CLT_LINK_EV_RECONNECTED); 2129 mutex_unlock(&clt->paths_ev_mutex); 2130 2131 /* Mark session as established */ 2132 clt_path->established = true; 2133 clt_path->reconnect_attempts = 0; 2134 clt_path->stats->reconnects.successful_cnt++; 2135 } 2136 2137 static void rtrs_clt_path_down(struct rtrs_clt_path *clt_path) 2138 { 2139 struct rtrs_clt_sess *clt = clt_path->clt; 2140 2141 if (!clt_path->established) 2142 return; 2143 2144 clt_path->established = false; 2145 mutex_lock(&clt->paths_ev_mutex); 2146 WARN_ON(!clt->paths_up); 2147 if (--clt->paths_up == 0) 2148 clt->link_ev(clt->priv, RTRS_CLT_LINK_EV_DISCONNECTED); 2149 mutex_unlock(&clt->paths_ev_mutex); 2150 } 2151 2152 static void rtrs_clt_stop_and_destroy_conns(struct rtrs_clt_path *clt_path) 2153 { 2154 struct rtrs_clt_con *con; 2155 unsigned int cid; 2156 2157 WARN_ON(READ_ONCE(clt_path->state) == RTRS_CLT_CONNECTED); 2158 2159 /* 2160 * Possible race with rtrs_clt_open(), when DEVICE_REMOVAL comes 2161 * exactly in between. Start destroying after it finishes. 2162 */ 2163 mutex_lock(&clt_path->init_mutex); 2164 mutex_unlock(&clt_path->init_mutex); 2165 2166 /* 2167 * All IO paths must observe !CONNECTED state before we 2168 * free everything. 2169 */ 2170 synchronize_rcu(); 2171 2172 rtrs_stop_hb(&clt_path->s); 2173 2174 /* 2175 * The order it utterly crucial: firstly disconnect and complete all 2176 * rdma requests with error (thus set in_use=false for requests), 2177 * then fail outstanding requests checking in_use for each, and 2178 * eventually notify upper layer about session disconnection. 2179 */ 2180 2181 for (cid = 0; cid < clt_path->s.con_num; cid++) { 2182 if (!clt_path->s.con[cid]) 2183 break; 2184 con = to_clt_con(clt_path->s.con[cid]); 2185 stop_cm(con); 2186 } 2187 fail_all_outstanding_reqs(clt_path); 2188 free_path_reqs(clt_path); 2189 rtrs_clt_path_down(clt_path); 2190 2191 /* 2192 * Wait for graceful shutdown, namely when peer side invokes 2193 * rdma_disconnect(). 'connected_cnt' is decremented only on 2194 * CM events, thus if other side had crashed and hb has detected 2195 * something is wrong, here we will stuck for exactly timeout ms, 2196 * since CM does not fire anything. That is fine, we are not in 2197 * hurry. 2198 */ 2199 wait_event_timeout(clt_path->state_wq, 2200 !atomic_read(&clt_path->connected_cnt), 2201 msecs_to_jiffies(RTRS_CONNECT_TIMEOUT_MS)); 2202 2203 for (cid = 0; cid < clt_path->s.con_num; cid++) { 2204 if (!clt_path->s.con[cid]) 2205 break; 2206 con = to_clt_con(clt_path->s.con[cid]); 2207 mutex_lock(&con->con_mutex); 2208 destroy_con_cq_qp(con); 2209 mutex_unlock(&con->con_mutex); 2210 destroy_cm(con); 2211 destroy_con(con); 2212 } 2213 } 2214 2215 static inline bool xchg_paths(struct rtrs_clt_path __rcu **rcu_ppcpu_path, 2216 struct rtrs_clt_path *clt_path, 2217 struct rtrs_clt_path *next) 2218 { 2219 struct rtrs_clt_path **ppcpu_path; 2220 2221 /* Call cmpxchg() without sparse warnings */ 2222 ppcpu_path = (typeof(ppcpu_path))rcu_ppcpu_path; 2223 return clt_path == cmpxchg(ppcpu_path, clt_path, next); 2224 } 2225 2226 static void rtrs_clt_remove_path_from_arr(struct rtrs_clt_path *clt_path) 2227 { 2228 struct rtrs_clt_sess *clt = clt_path->clt; 2229 struct rtrs_clt_path *next; 2230 bool wait_for_grace = false; 2231 int cpu; 2232 2233 mutex_lock(&clt->paths_mutex); 2234 list_del_rcu(&clt_path->s.entry); 2235 2236 /* Make sure everybody observes path removal. */ 2237 synchronize_rcu(); 2238 2239 /* 2240 * At this point nobody sees @sess in the list, but still we have 2241 * dangling pointer @pcpu_path which _can_ point to @sess. Since 2242 * nobody can observe @sess in the list, we guarantee that IO path 2243 * will not assign @sess to @pcpu_path, i.e. @pcpu_path can be equal 2244 * to @sess, but can never again become @sess. 2245 */ 2246 2247 /* 2248 * Decrement paths number only after grace period, because 2249 * caller of do_each_path() must firstly observe list without 2250 * path and only then decremented paths number. 2251 * 2252 * Otherwise there can be the following situation: 2253 * o Two paths exist and IO is coming. 2254 * o One path is removed: 2255 * CPU#0 CPU#1 2256 * do_each_path(): rtrs_clt_remove_path_from_arr(): 2257 * path = get_next_path() 2258 * ^^^ list_del_rcu(path) 2259 * [!CONNECTED path] clt->paths_num-- 2260 * ^^^^^^^^^ 2261 * load clt->paths_num from 2 to 1 2262 * ^^^^^^^^^ 2263 * sees 1 2264 * 2265 * path is observed as !CONNECTED, but do_each_path() loop 2266 * ends, because expression i < clt->paths_num is false. 2267 */ 2268 clt->paths_num--; 2269 2270 /* 2271 * Get @next connection from current @sess which is going to be 2272 * removed. If @sess is the last element, then @next is NULL. 2273 */ 2274 rcu_read_lock(); 2275 next = rtrs_clt_get_next_path_or_null(&clt->paths_list, clt_path); 2276 rcu_read_unlock(); 2277 2278 /* 2279 * @pcpu paths can still point to the path which is going to be 2280 * removed, so change the pointer manually. 2281 */ 2282 for_each_possible_cpu(cpu) { 2283 struct rtrs_clt_path __rcu **ppcpu_path; 2284 2285 ppcpu_path = per_cpu_ptr(clt->pcpu_path, cpu); 2286 if (rcu_dereference_protected(*ppcpu_path, 2287 lockdep_is_held(&clt->paths_mutex)) != clt_path) 2288 /* 2289 * synchronize_rcu() was called just after deleting 2290 * entry from the list, thus IO code path cannot 2291 * change pointer back to the pointer which is going 2292 * to be removed, we are safe here. 2293 */ 2294 continue; 2295 2296 /* 2297 * We race with IO code path, which also changes pointer, 2298 * thus we have to be careful not to overwrite it. 2299 */ 2300 if (xchg_paths(ppcpu_path, clt_path, next)) 2301 /* 2302 * @ppcpu_path was successfully replaced with @next, 2303 * that means that someone could also pick up the 2304 * @sess and dereferencing it right now, so wait for 2305 * a grace period is required. 2306 */ 2307 wait_for_grace = true; 2308 } 2309 if (wait_for_grace) 2310 synchronize_rcu(); 2311 2312 mutex_unlock(&clt->paths_mutex); 2313 } 2314 2315 static void rtrs_clt_add_path_to_arr(struct rtrs_clt_path *clt_path) 2316 { 2317 struct rtrs_clt_sess *clt = clt_path->clt; 2318 2319 mutex_lock(&clt->paths_mutex); 2320 clt->paths_num++; 2321 2322 list_add_tail_rcu(&clt_path->s.entry, &clt->paths_list); 2323 mutex_unlock(&clt->paths_mutex); 2324 } 2325 2326 static void rtrs_clt_close_work(struct work_struct *work) 2327 { 2328 struct rtrs_clt_path *clt_path; 2329 2330 clt_path = container_of(work, struct rtrs_clt_path, close_work); 2331 2332 cancel_work_sync(&clt_path->err_recovery_work); 2333 cancel_delayed_work_sync(&clt_path->reconnect_dwork); 2334 rtrs_clt_stop_and_destroy_conns(clt_path); 2335 rtrs_clt_change_state_get_old(clt_path, RTRS_CLT_CLOSED, NULL); 2336 } 2337 2338 static int init_conns(struct rtrs_clt_path *clt_path) 2339 { 2340 unsigned int cid; 2341 int err; 2342 2343 /* 2344 * On every new session connections increase reconnect counter 2345 * to avoid clashes with previous sessions not yet closed 2346 * sessions on a server side. 2347 */ 2348 clt_path->s.recon_cnt++; 2349 2350 /* Establish all RDMA connections */ 2351 for (cid = 0; cid < clt_path->s.con_num; cid++) { 2352 err = create_con(clt_path, cid); 2353 if (err) 2354 goto destroy; 2355 2356 err = create_cm(to_clt_con(clt_path->s.con[cid])); 2357 if (err) { 2358 destroy_con(to_clt_con(clt_path->s.con[cid])); 2359 goto destroy; 2360 } 2361 } 2362 err = alloc_path_reqs(clt_path); 2363 if (err) 2364 goto destroy; 2365 2366 rtrs_start_hb(&clt_path->s); 2367 2368 return 0; 2369 2370 destroy: 2371 while (cid--) { 2372 struct rtrs_clt_con *con = to_clt_con(clt_path->s.con[cid]); 2373 2374 stop_cm(con); 2375 2376 mutex_lock(&con->con_mutex); 2377 destroy_con_cq_qp(con); 2378 mutex_unlock(&con->con_mutex); 2379 destroy_cm(con); 2380 destroy_con(con); 2381 } 2382 /* 2383 * If we've never taken async path and got an error, say, 2384 * doing rdma_resolve_addr(), switch to CONNECTION_ERR state 2385 * manually to keep reconnecting. 2386 */ 2387 rtrs_clt_change_state_get_old(clt_path, RTRS_CLT_CONNECTING_ERR, NULL); 2388 2389 return err; 2390 } 2391 2392 static void rtrs_clt_info_req_done(struct ib_cq *cq, struct ib_wc *wc) 2393 { 2394 struct rtrs_clt_con *con = to_clt_con(wc->qp->qp_context); 2395 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path); 2396 struct rtrs_iu *iu; 2397 2398 iu = container_of(wc->wr_cqe, struct rtrs_iu, cqe); 2399 rtrs_iu_free(iu, clt_path->s.dev->ib_dev, 1); 2400 2401 if (wc->status != IB_WC_SUCCESS) { 2402 rtrs_err(clt_path->clt, "Path info request send failed: %s\n", 2403 ib_wc_status_msg(wc->status)); 2404 rtrs_clt_change_state_get_old(clt_path, RTRS_CLT_CONNECTING_ERR, NULL); 2405 return; 2406 } 2407 2408 rtrs_clt_update_wc_stats(con); 2409 } 2410 2411 static int process_info_rsp(struct rtrs_clt_path *clt_path, 2412 const struct rtrs_msg_info_rsp *msg) 2413 { 2414 unsigned int sg_cnt, total_len; 2415 int i, sgi; 2416 2417 sg_cnt = le16_to_cpu(msg->sg_cnt); 2418 if (!sg_cnt || (clt_path->queue_depth % sg_cnt)) { 2419 rtrs_err(clt_path->clt, 2420 "Incorrect sg_cnt %d, is not multiple\n", 2421 sg_cnt); 2422 return -EINVAL; 2423 } 2424 2425 /* 2426 * Check if IB immediate data size is enough to hold the mem_id and 2427 * the offset inside the memory chunk. 2428 */ 2429 if ((ilog2(sg_cnt - 1) + 1) + (ilog2(clt_path->chunk_size - 1) + 1) > 2430 MAX_IMM_PAYL_BITS) { 2431 rtrs_err(clt_path->clt, 2432 "RDMA immediate size (%db) not enough to encode %d buffers of size %dB\n", 2433 MAX_IMM_PAYL_BITS, sg_cnt, clt_path->chunk_size); 2434 return -EINVAL; 2435 } 2436 total_len = 0; 2437 for (sgi = 0, i = 0; sgi < sg_cnt && i < clt_path->queue_depth; sgi++) { 2438 const struct rtrs_sg_desc *desc = &msg->desc[sgi]; 2439 u32 len, rkey; 2440 u64 addr; 2441 2442 addr = le64_to_cpu(desc->addr); 2443 rkey = le32_to_cpu(desc->key); 2444 len = le32_to_cpu(desc->len); 2445 2446 total_len += len; 2447 2448 if (!len || (len % clt_path->chunk_size)) { 2449 rtrs_err(clt_path->clt, "Incorrect [%d].len %d\n", 2450 sgi, 2451 len); 2452 return -EINVAL; 2453 } 2454 for ( ; len && i < clt_path->queue_depth; i++) { 2455 clt_path->rbufs[i].addr = addr; 2456 clt_path->rbufs[i].rkey = rkey; 2457 2458 len -= clt_path->chunk_size; 2459 addr += clt_path->chunk_size; 2460 } 2461 } 2462 /* Sanity check */ 2463 if (sgi != sg_cnt || i != clt_path->queue_depth) { 2464 rtrs_err(clt_path->clt, 2465 "Incorrect sg vector, not fully mapped\n"); 2466 return -EINVAL; 2467 } 2468 if (total_len != clt_path->chunk_size * clt_path->queue_depth) { 2469 rtrs_err(clt_path->clt, "Incorrect total_len %d\n", total_len); 2470 return -EINVAL; 2471 } 2472 2473 return 0; 2474 } 2475 2476 static void rtrs_clt_info_rsp_done(struct ib_cq *cq, struct ib_wc *wc) 2477 { 2478 struct rtrs_clt_con *con = to_clt_con(wc->qp->qp_context); 2479 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path); 2480 struct rtrs_msg_info_rsp *msg; 2481 enum rtrs_clt_state state; 2482 struct rtrs_iu *iu; 2483 size_t rx_sz; 2484 int err; 2485 2486 state = RTRS_CLT_CONNECTING_ERR; 2487 2488 WARN_ON(con->c.cid); 2489 iu = container_of(wc->wr_cqe, struct rtrs_iu, cqe); 2490 if (wc->status != IB_WC_SUCCESS) { 2491 rtrs_err(clt_path->clt, "Path info response recv failed: %s\n", 2492 ib_wc_status_msg(wc->status)); 2493 goto out; 2494 } 2495 WARN_ON(wc->opcode != IB_WC_RECV); 2496 2497 if (wc->byte_len < sizeof(*msg)) { 2498 rtrs_err(clt_path->clt, "Path info response is malformed: size %d\n", 2499 wc->byte_len); 2500 goto out; 2501 } 2502 ib_dma_sync_single_for_cpu(clt_path->s.dev->ib_dev, iu->dma_addr, 2503 iu->size, DMA_FROM_DEVICE); 2504 msg = iu->buf; 2505 if (le16_to_cpu(msg->type) != RTRS_MSG_INFO_RSP) { 2506 rtrs_err(clt_path->clt, "Path info response is malformed: type %d\n", 2507 le16_to_cpu(msg->type)); 2508 goto out; 2509 } 2510 rx_sz = sizeof(*msg); 2511 rx_sz += sizeof(msg->desc[0]) * le16_to_cpu(msg->sg_cnt); 2512 if (wc->byte_len < rx_sz) { 2513 rtrs_err(clt_path->clt, "Path info response is malformed: size %d\n", 2514 wc->byte_len); 2515 goto out; 2516 } 2517 err = process_info_rsp(clt_path, msg); 2518 if (err) 2519 goto out; 2520 2521 err = post_recv_path(clt_path); 2522 if (err) 2523 goto out; 2524 2525 state = RTRS_CLT_CONNECTED; 2526 2527 out: 2528 rtrs_clt_update_wc_stats(con); 2529 rtrs_iu_free(iu, clt_path->s.dev->ib_dev, 1); 2530 rtrs_clt_change_state_get_old(clt_path, state, NULL); 2531 } 2532 2533 static int rtrs_send_path_info(struct rtrs_clt_path *clt_path) 2534 { 2535 struct rtrs_clt_con *usr_con = to_clt_con(clt_path->s.con[0]); 2536 struct rtrs_msg_info_req *msg; 2537 struct rtrs_iu *tx_iu, *rx_iu; 2538 size_t rx_sz; 2539 int err; 2540 2541 rx_sz = sizeof(struct rtrs_msg_info_rsp); 2542 rx_sz += sizeof(struct rtrs_sg_desc) * clt_path->queue_depth; 2543 2544 tx_iu = rtrs_iu_alloc(1, sizeof(struct rtrs_msg_info_req), GFP_KERNEL, 2545 clt_path->s.dev->ib_dev, DMA_TO_DEVICE, 2546 rtrs_clt_info_req_done); 2547 rx_iu = rtrs_iu_alloc(1, rx_sz, GFP_KERNEL, clt_path->s.dev->ib_dev, 2548 DMA_FROM_DEVICE, rtrs_clt_info_rsp_done); 2549 if (!tx_iu || !rx_iu) { 2550 err = -ENOMEM; 2551 goto out; 2552 } 2553 /* Prepare for getting info response */ 2554 err = rtrs_iu_post_recv(&usr_con->c, rx_iu); 2555 if (err) { 2556 rtrs_err(clt_path->clt, "rtrs_iu_post_recv(), err: %d\n", err); 2557 goto out; 2558 } 2559 rx_iu = NULL; 2560 2561 msg = tx_iu->buf; 2562 msg->type = cpu_to_le16(RTRS_MSG_INFO_REQ); 2563 memcpy(msg->pathname, clt_path->s.sessname, sizeof(msg->pathname)); 2564 2565 ib_dma_sync_single_for_device(clt_path->s.dev->ib_dev, 2566 tx_iu->dma_addr, 2567 tx_iu->size, DMA_TO_DEVICE); 2568 2569 /* Send info request */ 2570 err = rtrs_iu_post_send(&usr_con->c, tx_iu, sizeof(*msg), NULL); 2571 if (err) { 2572 rtrs_err(clt_path->clt, "rtrs_iu_post_send(), err: %d\n", err); 2573 goto out; 2574 } 2575 tx_iu = NULL; 2576 2577 /* Wait for state change */ 2578 wait_event_interruptible_timeout(clt_path->state_wq, 2579 clt_path->state != RTRS_CLT_CONNECTING, 2580 msecs_to_jiffies( 2581 RTRS_CONNECT_TIMEOUT_MS)); 2582 if (READ_ONCE(clt_path->state) != RTRS_CLT_CONNECTED) { 2583 if (READ_ONCE(clt_path->state) == RTRS_CLT_CONNECTING_ERR) 2584 err = -ECONNRESET; 2585 else 2586 err = -ETIMEDOUT; 2587 } 2588 2589 out: 2590 if (tx_iu) 2591 rtrs_iu_free(tx_iu, clt_path->s.dev->ib_dev, 1); 2592 if (rx_iu) 2593 rtrs_iu_free(rx_iu, clt_path->s.dev->ib_dev, 1); 2594 if (err) 2595 /* If we've never taken async path because of malloc problems */ 2596 rtrs_clt_change_state_get_old(clt_path, 2597 RTRS_CLT_CONNECTING_ERR, NULL); 2598 2599 return err; 2600 } 2601 2602 /** 2603 * init_path() - establishes all path connections and does handshake 2604 * @clt_path: client path. 2605 * In case of error full close or reconnect procedure should be taken, 2606 * because reconnect or close async works can be started. 2607 */ 2608 static int init_path(struct rtrs_clt_path *clt_path) 2609 { 2610 int err; 2611 char str[NAME_MAX]; 2612 struct rtrs_addr path = { 2613 .src = &clt_path->s.src_addr, 2614 .dst = &clt_path->s.dst_addr, 2615 }; 2616 2617 rtrs_addr_to_str(&path, str, sizeof(str)); 2618 2619 mutex_lock(&clt_path->init_mutex); 2620 err = init_conns(clt_path); 2621 if (err) { 2622 rtrs_err(clt_path->clt, 2623 "init_conns() failed: err=%d path=%s [%s:%u]\n", err, 2624 str, clt_path->hca_name, clt_path->hca_port); 2625 goto out; 2626 } 2627 err = rtrs_send_path_info(clt_path); 2628 if (err) { 2629 rtrs_err(clt_path->clt, 2630 "rtrs_send_path_info() failed: err=%d path=%s [%s:%u]\n", 2631 err, str, clt_path->hca_name, clt_path->hca_port); 2632 goto out; 2633 } 2634 rtrs_clt_path_up(clt_path); 2635 out: 2636 mutex_unlock(&clt_path->init_mutex); 2637 2638 return err; 2639 } 2640 2641 static void rtrs_clt_reconnect_work(struct work_struct *work) 2642 { 2643 struct rtrs_clt_path *clt_path; 2644 struct rtrs_clt_sess *clt; 2645 int err; 2646 2647 clt_path = container_of(to_delayed_work(work), struct rtrs_clt_path, 2648 reconnect_dwork); 2649 clt = clt_path->clt; 2650 2651 if (READ_ONCE(clt_path->state) != RTRS_CLT_RECONNECTING) 2652 return; 2653 2654 if (clt_path->reconnect_attempts >= clt->max_reconnect_attempts) { 2655 /* Close a path completely if max attempts is reached */ 2656 rtrs_clt_close_conns(clt_path, false); 2657 return; 2658 } 2659 clt_path->reconnect_attempts++; 2660 2661 msleep(RTRS_RECONNECT_BACKOFF); 2662 if (rtrs_clt_change_state_get_old(clt_path, RTRS_CLT_CONNECTING, NULL)) { 2663 err = init_path(clt_path); 2664 if (err) 2665 goto reconnect_again; 2666 } 2667 2668 return; 2669 2670 reconnect_again: 2671 if (rtrs_clt_change_state_get_old(clt_path, RTRS_CLT_RECONNECTING, NULL)) { 2672 clt_path->stats->reconnects.fail_cnt++; 2673 queue_work(rtrs_wq, &clt_path->err_recovery_work); 2674 } 2675 } 2676 2677 static void rtrs_clt_dev_release(struct device *dev) 2678 { 2679 struct rtrs_clt_sess *clt = container_of(dev, struct rtrs_clt_sess, 2680 dev); 2681 2682 mutex_destroy(&clt->paths_ev_mutex); 2683 mutex_destroy(&clt->paths_mutex); 2684 kfree(clt); 2685 } 2686 2687 static struct rtrs_clt_sess *alloc_clt(const char *sessname, size_t paths_num, 2688 u16 port, size_t pdu_sz, void *priv, 2689 void (*link_ev)(void *priv, 2690 enum rtrs_clt_link_ev ev), 2691 unsigned int reconnect_delay_sec, 2692 unsigned int max_reconnect_attempts) 2693 { 2694 struct rtrs_clt_sess *clt; 2695 int err; 2696 2697 if (!paths_num || paths_num > MAX_PATHS_NUM) 2698 return ERR_PTR(-EINVAL); 2699 2700 if (strlen(sessname) >= sizeof(clt->sessname)) 2701 return ERR_PTR(-EINVAL); 2702 2703 clt = kzalloc(sizeof(*clt), GFP_KERNEL); 2704 if (!clt) 2705 return ERR_PTR(-ENOMEM); 2706 2707 clt->pcpu_path = alloc_percpu(typeof(*clt->pcpu_path)); 2708 if (!clt->pcpu_path) { 2709 kfree(clt); 2710 return ERR_PTR(-ENOMEM); 2711 } 2712 2713 clt->dev.class = rtrs_clt_dev_class; 2714 clt->dev.release = rtrs_clt_dev_release; 2715 uuid_gen(&clt->paths_uuid); 2716 INIT_LIST_HEAD_RCU(&clt->paths_list); 2717 clt->paths_num = paths_num; 2718 clt->paths_up = MAX_PATHS_NUM; 2719 clt->port = port; 2720 clt->pdu_sz = pdu_sz; 2721 clt->max_segments = RTRS_MAX_SEGMENTS; 2722 clt->reconnect_delay_sec = reconnect_delay_sec; 2723 clt->max_reconnect_attempts = max_reconnect_attempts; 2724 clt->priv = priv; 2725 clt->link_ev = link_ev; 2726 clt->mp_policy = MP_POLICY_MIN_INFLIGHT; 2727 strscpy(clt->sessname, sessname, sizeof(clt->sessname)); 2728 init_waitqueue_head(&clt->permits_wait); 2729 mutex_init(&clt->paths_ev_mutex); 2730 mutex_init(&clt->paths_mutex); 2731 device_initialize(&clt->dev); 2732 2733 err = dev_set_name(&clt->dev, "%s", sessname); 2734 if (err) 2735 goto err_put; 2736 2737 /* 2738 * Suppress user space notification until 2739 * sysfs files are created 2740 */ 2741 dev_set_uevent_suppress(&clt->dev, true); 2742 err = device_add(&clt->dev); 2743 if (err) 2744 goto err_put; 2745 2746 clt->kobj_paths = kobject_create_and_add("paths", &clt->dev.kobj); 2747 if (!clt->kobj_paths) { 2748 err = -ENOMEM; 2749 goto err_del; 2750 } 2751 err = rtrs_clt_create_sysfs_root_files(clt); 2752 if (err) { 2753 kobject_del(clt->kobj_paths); 2754 kobject_put(clt->kobj_paths); 2755 goto err_del; 2756 } 2757 dev_set_uevent_suppress(&clt->dev, false); 2758 kobject_uevent(&clt->dev.kobj, KOBJ_ADD); 2759 2760 return clt; 2761 err_del: 2762 device_del(&clt->dev); 2763 err_put: 2764 free_percpu(clt->pcpu_path); 2765 put_device(&clt->dev); 2766 return ERR_PTR(err); 2767 } 2768 2769 static void free_clt(struct rtrs_clt_sess *clt) 2770 { 2771 free_percpu(clt->pcpu_path); 2772 2773 /* 2774 * release callback will free clt and destroy mutexes in last put 2775 */ 2776 device_unregister(&clt->dev); 2777 } 2778 2779 /** 2780 * rtrs_clt_open() - Open a path to an RTRS server 2781 * @ops: holds the link event callback and the private pointer. 2782 * @pathname: name of the path to an RTRS server 2783 * @paths: Paths to be established defined by their src and dst addresses 2784 * @paths_num: Number of elements in the @paths array 2785 * @port: port to be used by the RTRS session 2786 * @pdu_sz: Size of extra payload which can be accessed after permit allocation. 2787 * @reconnect_delay_sec: time between reconnect tries 2788 * @max_reconnect_attempts: Number of times to reconnect on error before giving 2789 * up, 0 for * disabled, -1 for forever 2790 * @nr_poll_queues: number of polling mode connection using IB_POLL_DIRECT flag 2791 * 2792 * Starts session establishment with the rtrs_server. The function can block 2793 * up to ~2000ms before it returns. 2794 * 2795 * Return a valid pointer on success otherwise PTR_ERR. 2796 */ 2797 struct rtrs_clt_sess *rtrs_clt_open(struct rtrs_clt_ops *ops, 2798 const char *pathname, 2799 const struct rtrs_addr *paths, 2800 size_t paths_num, u16 port, 2801 size_t pdu_sz, u8 reconnect_delay_sec, 2802 s16 max_reconnect_attempts, u32 nr_poll_queues) 2803 { 2804 struct rtrs_clt_path *clt_path, *tmp; 2805 struct rtrs_clt_sess *clt; 2806 int err, i; 2807 2808 if (strchr(pathname, '/') || strchr(pathname, '.')) { 2809 pr_err("pathname cannot contain / and .\n"); 2810 err = -EINVAL; 2811 goto out; 2812 } 2813 2814 clt = alloc_clt(pathname, paths_num, port, pdu_sz, ops->priv, 2815 ops->link_ev, 2816 reconnect_delay_sec, 2817 max_reconnect_attempts); 2818 if (IS_ERR(clt)) { 2819 err = PTR_ERR(clt); 2820 goto out; 2821 } 2822 for (i = 0; i < paths_num; i++) { 2823 struct rtrs_clt_path *clt_path; 2824 2825 clt_path = alloc_path(clt, &paths[i], nr_cpu_ids, 2826 nr_poll_queues); 2827 if (IS_ERR(clt_path)) { 2828 err = PTR_ERR(clt_path); 2829 goto close_all_path; 2830 } 2831 if (!i) 2832 clt_path->for_new_clt = 1; 2833 list_add_tail_rcu(&clt_path->s.entry, &clt->paths_list); 2834 2835 err = init_path(clt_path); 2836 if (err) { 2837 list_del_rcu(&clt_path->s.entry); 2838 rtrs_clt_close_conns(clt_path, true); 2839 free_percpu(clt_path->stats->pcpu_stats); 2840 kfree(clt_path->stats); 2841 free_path(clt_path); 2842 goto close_all_path; 2843 } 2844 2845 err = rtrs_clt_create_path_files(clt_path); 2846 if (err) { 2847 list_del_rcu(&clt_path->s.entry); 2848 rtrs_clt_close_conns(clt_path, true); 2849 free_percpu(clt_path->stats->pcpu_stats); 2850 kfree(clt_path->stats); 2851 free_path(clt_path); 2852 goto close_all_path; 2853 } 2854 } 2855 err = alloc_permits(clt); 2856 if (err) 2857 goto close_all_path; 2858 2859 return clt; 2860 2861 close_all_path: 2862 list_for_each_entry_safe(clt_path, tmp, &clt->paths_list, s.entry) { 2863 rtrs_clt_destroy_path_files(clt_path, NULL); 2864 rtrs_clt_close_conns(clt_path, true); 2865 kobject_put(&clt_path->kobj); 2866 } 2867 rtrs_clt_destroy_sysfs_root(clt); 2868 free_clt(clt); 2869 2870 out: 2871 return ERR_PTR(err); 2872 } 2873 EXPORT_SYMBOL(rtrs_clt_open); 2874 2875 /** 2876 * rtrs_clt_close() - Close a path 2877 * @clt: Session handle. Session is freed upon return. 2878 */ 2879 void rtrs_clt_close(struct rtrs_clt_sess *clt) 2880 { 2881 struct rtrs_clt_path *clt_path, *tmp; 2882 2883 /* Firstly forbid sysfs access */ 2884 rtrs_clt_destroy_sysfs_root(clt); 2885 2886 /* Now it is safe to iterate over all paths without locks */ 2887 list_for_each_entry_safe(clt_path, tmp, &clt->paths_list, s.entry) { 2888 rtrs_clt_close_conns(clt_path, true); 2889 rtrs_clt_destroy_path_files(clt_path, NULL); 2890 kobject_put(&clt_path->kobj); 2891 } 2892 free_permits(clt); 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 rtrs_clt_stop_and_destroy_conns(clt_path); 2909 queue_delayed_work(rtrs_wq, &clt_path->reconnect_dwork, 0); 2910 } 2911 if (changed || old_state == RTRS_CLT_RECONNECTING) { 2912 /* 2913 * flush_delayed_work() queues pending work for immediate 2914 * execution, so do the flush if we have queued something 2915 * right now or work is pending. 2916 */ 2917 flush_delayed_work(&clt_path->reconnect_dwork); 2918 err = (READ_ONCE(clt_path->state) == 2919 RTRS_CLT_CONNECTED ? 0 : -ENOTCONN); 2920 } 2921 2922 return err; 2923 } 2924 2925 int rtrs_clt_remove_path_from_sysfs(struct rtrs_clt_path *clt_path, 2926 const struct attribute *sysfs_self) 2927 { 2928 enum rtrs_clt_state old_state; 2929 bool changed; 2930 2931 /* 2932 * Continue stopping path till state was changed to DEAD or 2933 * state was observed as DEAD: 2934 * 1. State was changed to DEAD - we were fast and nobody 2935 * invoked rtrs_clt_reconnect(), which can again start 2936 * reconnecting. 2937 * 2. State was observed as DEAD - we have someone in parallel 2938 * removing the path. 2939 */ 2940 do { 2941 rtrs_clt_close_conns(clt_path, true); 2942 changed = rtrs_clt_change_state_get_old(clt_path, 2943 RTRS_CLT_DEAD, 2944 &old_state); 2945 } while (!changed && old_state != RTRS_CLT_DEAD); 2946 2947 if (changed) { 2948 rtrs_clt_remove_path_from_arr(clt_path); 2949 rtrs_clt_destroy_path_files(clt_path, sysfs_self); 2950 kobject_put(&clt_path->kobj); 2951 } 2952 2953 return 0; 2954 } 2955 2956 void rtrs_clt_set_max_reconnect_attempts(struct rtrs_clt_sess *clt, int value) 2957 { 2958 clt->max_reconnect_attempts = (unsigned int)value; 2959 } 2960 2961 int rtrs_clt_get_max_reconnect_attempts(const struct rtrs_clt_sess *clt) 2962 { 2963 return (int)clt->max_reconnect_attempts; 2964 } 2965 2966 /** 2967 * rtrs_clt_request() - Request data transfer to/from server via RDMA. 2968 * 2969 * @dir: READ/WRITE 2970 * @ops: callback function to be called as confirmation, and the pointer. 2971 * @clt: Session 2972 * @permit: Preallocated permit 2973 * @vec: Message that is sent to server together with the request. 2974 * Sum of len of all @vec elements limited to <= IO_MSG_SIZE. 2975 * Since the msg is copied internally it can be allocated on stack. 2976 * @nr: Number of elements in @vec. 2977 * @data_len: length of data sent to/from server 2978 * @sg: Pages to be sent/received to/from server. 2979 * @sg_cnt: Number of elements in the @sg 2980 * 2981 * Return: 2982 * 0: Success 2983 * <0: Error 2984 * 2985 * On dir=READ rtrs client will request a data transfer from Server to client. 2986 * The data that the server will respond with will be stored in @sg when 2987 * the user receives an %RTRS_CLT_RDMA_EV_RDMA_REQUEST_WRITE_COMPL event. 2988 * On dir=WRITE rtrs client will rdma write data in sg to server side. 2989 */ 2990 int rtrs_clt_request(int dir, struct rtrs_clt_req_ops *ops, 2991 struct rtrs_clt_sess *clt, struct rtrs_permit *permit, 2992 const struct kvec *vec, size_t nr, size_t data_len, 2993 struct scatterlist *sg, unsigned int sg_cnt) 2994 { 2995 struct rtrs_clt_io_req *req; 2996 struct rtrs_clt_path *clt_path; 2997 2998 enum dma_data_direction dma_dir; 2999 int err = -ECONNABORTED, i; 3000 size_t usr_len, hdr_len; 3001 struct path_it it; 3002 3003 /* Get kvec length */ 3004 for (i = 0, usr_len = 0; i < nr; i++) 3005 usr_len += vec[i].iov_len; 3006 3007 if (dir == READ) { 3008 hdr_len = sizeof(struct rtrs_msg_rdma_read) + 3009 sg_cnt * sizeof(struct rtrs_sg_desc); 3010 dma_dir = DMA_FROM_DEVICE; 3011 } else { 3012 hdr_len = sizeof(struct rtrs_msg_rdma_write); 3013 dma_dir = DMA_TO_DEVICE; 3014 } 3015 3016 rcu_read_lock(); 3017 for (path_it_init(&it, clt); 3018 (clt_path = it.next_path(&it)) && it.i < it.clt->paths_num; it.i++) { 3019 if (READ_ONCE(clt_path->state) != RTRS_CLT_CONNECTED) 3020 continue; 3021 3022 if (usr_len + hdr_len > clt_path->max_hdr_size) { 3023 rtrs_wrn_rl(clt_path->clt, 3024 "%s request failed, user message size is %zu and header length %zu, but max size is %u\n", 3025 dir == READ ? "Read" : "Write", 3026 usr_len, hdr_len, clt_path->max_hdr_size); 3027 err = -EMSGSIZE; 3028 break; 3029 } 3030 req = rtrs_clt_get_req(clt_path, ops->conf_fn, permit, ops->priv, 3031 vec, usr_len, sg, sg_cnt, data_len, 3032 dma_dir); 3033 if (dir == READ) 3034 err = rtrs_clt_read_req(req); 3035 else 3036 err = rtrs_clt_write_req(req); 3037 if (err) { 3038 req->in_use = false; 3039 continue; 3040 } 3041 /* Success path */ 3042 break; 3043 } 3044 path_it_deinit(&it); 3045 rcu_read_unlock(); 3046 3047 return err; 3048 } 3049 EXPORT_SYMBOL(rtrs_clt_request); 3050 3051 int rtrs_clt_rdma_cq_direct(struct rtrs_clt_sess *clt, unsigned int index) 3052 { 3053 /* If no path, return -1 for block layer not to try again */ 3054 int cnt = -1; 3055 struct rtrs_con *con; 3056 struct rtrs_clt_path *clt_path; 3057 struct path_it it; 3058 3059 rcu_read_lock(); 3060 for (path_it_init(&it, clt); 3061 (clt_path = it.next_path(&it)) && it.i < it.clt->paths_num; it.i++) { 3062 if (READ_ONCE(clt_path->state) != RTRS_CLT_CONNECTED) 3063 continue; 3064 3065 con = clt_path->s.con[index + 1]; 3066 cnt = ib_process_cq_direct(con->cq, -1); 3067 if (cnt) 3068 break; 3069 } 3070 path_it_deinit(&it); 3071 rcu_read_unlock(); 3072 3073 return cnt; 3074 } 3075 EXPORT_SYMBOL(rtrs_clt_rdma_cq_direct); 3076 3077 /** 3078 * rtrs_clt_query() - queries RTRS session attributes 3079 *@clt: session pointer 3080 *@attr: query results for session attributes. 3081 * Returns: 3082 * 0 on success 3083 * -ECOMM no connection to the server 3084 */ 3085 int rtrs_clt_query(struct rtrs_clt_sess *clt, struct rtrs_attrs *attr) 3086 { 3087 if (!rtrs_clt_is_connected(clt)) 3088 return -ECOMM; 3089 3090 attr->queue_depth = clt->queue_depth; 3091 attr->max_segments = clt->max_segments; 3092 /* Cap max_io_size to min of remote buffer size and the fr pages */ 3093 attr->max_io_size = min_t(int, clt->max_io_size, 3094 clt->max_segments * SZ_4K); 3095 3096 return 0; 3097 } 3098 EXPORT_SYMBOL(rtrs_clt_query); 3099 3100 int rtrs_clt_create_path_from_sysfs(struct rtrs_clt_sess *clt, 3101 struct rtrs_addr *addr) 3102 { 3103 struct rtrs_clt_path *clt_path; 3104 int err; 3105 3106 clt_path = alloc_path(clt, addr, nr_cpu_ids, 0); 3107 if (IS_ERR(clt_path)) 3108 return PTR_ERR(clt_path); 3109 3110 mutex_lock(&clt->paths_mutex); 3111 if (clt->paths_num == 0) { 3112 /* 3113 * When all the paths are removed for a session, 3114 * the addition of the first path is like a new session for 3115 * the storage server 3116 */ 3117 clt_path->for_new_clt = 1; 3118 } 3119 3120 mutex_unlock(&clt->paths_mutex); 3121 3122 /* 3123 * It is totally safe to add path in CONNECTING state: coming 3124 * IO will never grab it. Also it is very important to add 3125 * path before init, since init fires LINK_CONNECTED event. 3126 */ 3127 rtrs_clt_add_path_to_arr(clt_path); 3128 3129 err = init_path(clt_path); 3130 if (err) 3131 goto close_path; 3132 3133 err = rtrs_clt_create_path_files(clt_path); 3134 if (err) 3135 goto close_path; 3136 3137 return 0; 3138 3139 close_path: 3140 rtrs_clt_remove_path_from_arr(clt_path); 3141 rtrs_clt_close_conns(clt_path, true); 3142 free_percpu(clt_path->stats->pcpu_stats); 3143 kfree(clt_path->stats); 3144 free_path(clt_path); 3145 3146 return err; 3147 } 3148 3149 static int rtrs_clt_ib_dev_init(struct rtrs_ib_dev *dev) 3150 { 3151 if (!(dev->ib_dev->attrs.device_cap_flags & 3152 IB_DEVICE_MEM_MGT_EXTENSIONS)) { 3153 pr_err("Memory registrations not supported.\n"); 3154 return -ENOTSUPP; 3155 } 3156 3157 return 0; 3158 } 3159 3160 static const struct rtrs_rdma_dev_pd_ops dev_pd_ops = { 3161 .init = rtrs_clt_ib_dev_init 3162 }; 3163 3164 static int __init rtrs_client_init(void) 3165 { 3166 rtrs_rdma_dev_pd_init(0, &dev_pd); 3167 3168 rtrs_clt_dev_class = class_create(THIS_MODULE, "rtrs-client"); 3169 if (IS_ERR(rtrs_clt_dev_class)) { 3170 pr_err("Failed to create rtrs-client dev class\n"); 3171 return PTR_ERR(rtrs_clt_dev_class); 3172 } 3173 rtrs_wq = alloc_workqueue("rtrs_client_wq", 0, 0); 3174 if (!rtrs_wq) { 3175 class_destroy(rtrs_clt_dev_class); 3176 return -ENOMEM; 3177 } 3178 3179 return 0; 3180 } 3181 3182 static void __exit rtrs_client_exit(void) 3183 { 3184 destroy_workqueue(rtrs_wq); 3185 class_destroy(rtrs_clt_dev_class); 3186 rtrs_rdma_dev_pd_deinit(&dev_pd); 3187 } 3188 3189 module_init(rtrs_client_init); 3190 module_exit(rtrs_client_exit); 3191