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 #include "rtrs-clt-trace.h" 20 21 #define RTRS_CONNECT_TIMEOUT_MS 30000 22 /* 23 * Wait a bit before trying to reconnect after a failure 24 * in order to give server time to finish clean up which 25 * leads to "false positives" failed reconnect attempts 26 */ 27 #define RTRS_RECONNECT_BACKOFF 1000 28 /* 29 * Wait for additional random time between 0 and 8 seconds 30 * before starting to reconnect to avoid clients reconnecting 31 * all at once in case of a major network outage 32 */ 33 #define RTRS_RECONNECT_SEED 8 34 35 #define FIRST_CONN 0x01 36 /* limit to 128 * 4k = 512k max IO */ 37 #define RTRS_MAX_SEGMENTS 128 38 39 MODULE_DESCRIPTION("RDMA Transport Client"); 40 MODULE_LICENSE("GPL"); 41 42 static const struct rtrs_rdma_dev_pd_ops dev_pd_ops; 43 static struct rtrs_rdma_dev_pd dev_pd = { 44 .ops = &dev_pd_ops 45 }; 46 47 static struct workqueue_struct *rtrs_wq; 48 static const struct class rtrs_clt_dev_class = { 49 .name = "rtrs-client", 50 }; 51 52 static inline bool rtrs_clt_is_connected(const struct rtrs_clt_sess *clt) 53 { 54 struct rtrs_clt_path *clt_path; 55 bool connected = false; 56 57 rcu_read_lock(); 58 list_for_each_entry_rcu(clt_path, &clt->paths_list, s.entry) 59 if (READ_ONCE(clt_path->state) == RTRS_CLT_CONNECTED) { 60 connected = true; 61 break; 62 } 63 rcu_read_unlock(); 64 65 return connected; 66 } 67 68 static struct rtrs_permit * 69 __rtrs_get_permit(struct rtrs_clt_sess *clt, enum rtrs_clt_con_type con_type) 70 { 71 size_t max_depth = clt->queue_depth; 72 struct rtrs_permit *permit; 73 int bit; 74 75 /* 76 * Adapted from null_blk get_tag(). Callers from different cpus may 77 * grab the same bit, since find_first_zero_bit is not atomic. 78 * But then the test_and_set_bit_lock will fail for all the 79 * callers but one, so that they will loop again. 80 * This way an explicit spinlock is not required. 81 */ 82 do { 83 bit = find_first_zero_bit(clt->permits_map, max_depth); 84 if (bit >= max_depth) 85 return NULL; 86 } while (test_and_set_bit_lock(bit, clt->permits_map)); 87 88 permit = get_permit(clt, bit); 89 WARN_ON(permit->mem_id != bit); 90 permit->cpu_id = raw_smp_processor_id(); 91 permit->con_type = con_type; 92 93 return permit; 94 } 95 96 static inline void __rtrs_put_permit(struct rtrs_clt_sess *clt, 97 struct rtrs_permit *permit) 98 { 99 clear_bit_unlock(permit->mem_id, clt->permits_map); 100 } 101 102 /** 103 * rtrs_clt_get_permit() - allocates permit for future RDMA operation 104 * @clt: Current session 105 * @con_type: Type of connection to use with the permit 106 * @can_wait: Wait type 107 * 108 * Description: 109 * Allocates permit for the following RDMA operation. Permit is used 110 * to preallocate all resources and to propagate memory pressure 111 * up earlier. 112 * 113 * Context: 114 * Can sleep if @wait == RTRS_PERMIT_WAIT 115 */ 116 struct rtrs_permit *rtrs_clt_get_permit(struct rtrs_clt_sess *clt, 117 enum rtrs_clt_con_type con_type, 118 enum wait_type can_wait) 119 { 120 struct rtrs_permit *permit; 121 DEFINE_WAIT(wait); 122 123 permit = __rtrs_get_permit(clt, con_type); 124 if (permit || !can_wait) 125 return permit; 126 127 do { 128 prepare_to_wait(&clt->permits_wait, &wait, 129 TASK_UNINTERRUPTIBLE); 130 permit = __rtrs_get_permit(clt, con_type); 131 if (permit) 132 break; 133 134 io_schedule(); 135 } while (1); 136 137 finish_wait(&clt->permits_wait, &wait); 138 139 return permit; 140 } 141 EXPORT_SYMBOL(rtrs_clt_get_permit); 142 143 /** 144 * rtrs_clt_put_permit() - puts allocated permit 145 * @clt: Current session 146 * @permit: Permit to be freed 147 * 148 * Context: 149 * Does not matter 150 */ 151 void rtrs_clt_put_permit(struct rtrs_clt_sess *clt, 152 struct rtrs_permit *permit) 153 { 154 if (WARN_ON(!test_bit(permit->mem_id, clt->permits_map))) 155 return; 156 157 __rtrs_put_permit(clt, permit); 158 159 /* 160 * rtrs_clt_get_permit() adds itself to the &clt->permits_wait list 161 * before calling schedule(). So if rtrs_clt_get_permit() is sleeping 162 * it must have added itself to &clt->permits_wait before 163 * __rtrs_put_permit() finished. 164 * Hence it is safe to guard wake_up() with a waitqueue_active() test. 165 */ 166 if (waitqueue_active(&clt->permits_wait)) 167 wake_up(&clt->permits_wait); 168 } 169 EXPORT_SYMBOL(rtrs_clt_put_permit); 170 171 /** 172 * rtrs_permit_to_clt_con() - returns RDMA connection pointer by the permit 173 * @clt_path: client path pointer 174 * @permit: permit for the allocation of the RDMA buffer 175 * Note: 176 * IO connection starts from 1. 177 * 0 connection is for user messages. 178 */ 179 static 180 struct rtrs_clt_con *rtrs_permit_to_clt_con(struct rtrs_clt_path *clt_path, 181 struct rtrs_permit *permit) 182 { 183 int id = 0; 184 185 if (permit->con_type == RTRS_IO_CON) 186 id = (permit->cpu_id % (clt_path->s.irq_con_num - 1)) + 1; 187 188 return to_clt_con(clt_path->s.con[id]); 189 } 190 191 /** 192 * rtrs_clt_change_state() - change the session state through session state 193 * machine. 194 * 195 * @clt_path: client path to change the state of. 196 * @new_state: state to change to. 197 * 198 * returns true if sess's state is changed to new state, otherwise return false. 199 * 200 * Locks: 201 * state_wq lock must be hold. 202 */ 203 static bool rtrs_clt_change_state(struct rtrs_clt_path *clt_path, 204 enum rtrs_clt_state new_state) 205 { 206 enum rtrs_clt_state old_state; 207 bool changed = false; 208 209 lockdep_assert_held(&clt_path->state_wq.lock); 210 211 old_state = clt_path->state; 212 switch (new_state) { 213 case RTRS_CLT_CONNECTING: 214 switch (old_state) { 215 case RTRS_CLT_RECONNECTING: 216 changed = true; 217 fallthrough; 218 default: 219 break; 220 } 221 break; 222 case RTRS_CLT_RECONNECTING: 223 switch (old_state) { 224 case RTRS_CLT_CONNECTED: 225 case RTRS_CLT_CONNECTING_ERR: 226 case RTRS_CLT_CLOSED: 227 changed = true; 228 fallthrough; 229 default: 230 break; 231 } 232 break; 233 case RTRS_CLT_CONNECTED: 234 switch (old_state) { 235 case RTRS_CLT_CONNECTING: 236 changed = true; 237 fallthrough; 238 default: 239 break; 240 } 241 break; 242 case RTRS_CLT_CONNECTING_ERR: 243 switch (old_state) { 244 case RTRS_CLT_CONNECTING: 245 changed = true; 246 fallthrough; 247 default: 248 break; 249 } 250 break; 251 case RTRS_CLT_CLOSING: 252 switch (old_state) { 253 case RTRS_CLT_CONNECTING: 254 case RTRS_CLT_CONNECTING_ERR: 255 case RTRS_CLT_RECONNECTING: 256 case RTRS_CLT_CONNECTED: 257 changed = true; 258 fallthrough; 259 default: 260 break; 261 } 262 break; 263 case RTRS_CLT_CLOSED: 264 switch (old_state) { 265 case RTRS_CLT_CLOSING: 266 changed = true; 267 fallthrough; 268 default: 269 break; 270 } 271 break; 272 case RTRS_CLT_DEAD: 273 switch (old_state) { 274 case RTRS_CLT_CLOSED: 275 changed = true; 276 fallthrough; 277 default: 278 break; 279 } 280 break; 281 default: 282 break; 283 } 284 if (changed) { 285 clt_path->state = new_state; 286 wake_up_locked(&clt_path->state_wq); 287 } 288 289 return changed; 290 } 291 292 static bool rtrs_clt_change_state_from_to(struct rtrs_clt_path *clt_path, 293 enum rtrs_clt_state old_state, 294 enum rtrs_clt_state new_state) 295 { 296 bool changed = false; 297 298 spin_lock_irq(&clt_path->state_wq.lock); 299 if (clt_path->state == old_state) 300 changed = rtrs_clt_change_state(clt_path, new_state); 301 spin_unlock_irq(&clt_path->state_wq.lock); 302 303 return changed; 304 } 305 306 static void rtrs_clt_stop_and_destroy_conns(struct rtrs_clt_path *clt_path); 307 static void rtrs_rdma_error_recovery(struct rtrs_clt_con *con) 308 { 309 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path); 310 311 trace_rtrs_rdma_error_recovery(clt_path); 312 313 if (rtrs_clt_change_state_from_to(clt_path, 314 RTRS_CLT_CONNECTED, 315 RTRS_CLT_RECONNECTING)) { 316 queue_work(rtrs_wq, &clt_path->err_recovery_work); 317 } else { 318 /* 319 * Error can happen just on establishing new connection, 320 * so notify waiter with error state, waiter is responsible 321 * for cleaning the rest and reconnect if needed. 322 */ 323 rtrs_clt_change_state_from_to(clt_path, 324 RTRS_CLT_CONNECTING, 325 RTRS_CLT_CONNECTING_ERR); 326 } 327 } 328 329 static void rtrs_clt_fast_reg_done(struct ib_cq *cq, struct ib_wc *wc) 330 { 331 struct rtrs_clt_con *con = to_clt_con(wc->qp->qp_context); 332 333 if (wc->status != IB_WC_SUCCESS) { 334 rtrs_err(con->c.path, "Failed IB_WR_REG_MR: %s\n", 335 ib_wc_status_msg(wc->status)); 336 rtrs_rdma_error_recovery(con); 337 } 338 } 339 340 static struct ib_cqe fast_reg_cqe = { 341 .done = rtrs_clt_fast_reg_done 342 }; 343 344 static void complete_rdma_req(struct rtrs_clt_io_req *req, int errno, 345 bool notify, bool can_wait); 346 347 static void rtrs_clt_inv_rkey_done(struct ib_cq *cq, struct ib_wc *wc) 348 { 349 struct rtrs_clt_io_req *req = 350 container_of(wc->wr_cqe, typeof(*req), inv_cqe); 351 struct rtrs_clt_con *con = to_clt_con(wc->qp->qp_context); 352 353 if (wc->status != IB_WC_SUCCESS) { 354 rtrs_err(con->c.path, "Failed IB_WR_LOCAL_INV: %s\n", 355 ib_wc_status_msg(wc->status)); 356 rtrs_rdma_error_recovery(con); 357 } 358 req->need_inv = false; 359 if (req->need_inv_comp) 360 complete(&req->inv_comp); 361 else 362 /* Complete request from INV callback */ 363 complete_rdma_req(req, req->inv_errno, true, false); 364 } 365 366 static int rtrs_inv_rkey(struct rtrs_clt_io_req *req) 367 { 368 struct rtrs_clt_con *con = req->con; 369 struct ib_send_wr wr = { 370 .opcode = IB_WR_LOCAL_INV, 371 .wr_cqe = &req->inv_cqe, 372 .send_flags = IB_SEND_SIGNALED, 373 .ex.invalidate_rkey = req->mr->rkey, 374 }; 375 req->inv_cqe.done = rtrs_clt_inv_rkey_done; 376 377 return ib_post_send(con->c.qp, &wr, NULL); 378 } 379 380 static void complete_rdma_req(struct rtrs_clt_io_req *req, int errno, 381 bool notify, bool can_wait) 382 { 383 struct rtrs_clt_con *con = req->con; 384 struct rtrs_clt_path *clt_path; 385 int err; 386 387 if (WARN_ON(!req->in_use)) 388 return; 389 if (WARN_ON(!req->con)) 390 return; 391 clt_path = to_clt_path(con->c.path); 392 393 if (req->sg_cnt) { 394 if (req->dir == DMA_FROM_DEVICE && req->need_inv) { 395 /* 396 * We are here to invalidate read requests 397 * ourselves. In normal scenario server should 398 * send INV for all read requests, but 399 * we are here, thus two things could happen: 400 * 401 * 1. this is failover, when errno != 0 402 * and can_wait == 1, 403 * 404 * 2. something totally bad happened and 405 * server forgot to send INV, so we 406 * should do that ourselves. 407 */ 408 409 if (can_wait) { 410 req->need_inv_comp = true; 411 } else { 412 /* This should be IO path, so always notify */ 413 WARN_ON(!notify); 414 /* Save errno for INV callback */ 415 req->inv_errno = errno; 416 } 417 418 refcount_inc(&req->ref); 419 err = rtrs_inv_rkey(req); 420 if (err) { 421 rtrs_err(con->c.path, "Send INV WR key=%#x: %d\n", 422 req->mr->rkey, err); 423 } else if (can_wait) { 424 wait_for_completion(&req->inv_comp); 425 } else { 426 /* 427 * Something went wrong, so request will be 428 * completed from INV callback. 429 */ 430 WARN_ON_ONCE(1); 431 432 return; 433 } 434 if (!refcount_dec_and_test(&req->ref)) 435 return; 436 } 437 ib_dma_unmap_sg(clt_path->s.dev->ib_dev, req->sglist, 438 req->sg_cnt, req->dir); 439 } 440 if (!refcount_dec_and_test(&req->ref)) 441 return; 442 if (req->mp_policy == MP_POLICY_MIN_INFLIGHT) 443 atomic_dec(&clt_path->stats->inflight); 444 445 req->in_use = false; 446 req->con = NULL; 447 448 if (errno) { 449 rtrs_err_rl(con->c.path, "IO request failed: error=%d path=%s [%s:%u] notify=%d\n", 450 errno, kobject_name(&clt_path->kobj), clt_path->hca_name, 451 clt_path->hca_port, notify); 452 } 453 454 if (notify) 455 req->conf(req->priv, errno); 456 } 457 458 static int rtrs_post_send_rdma(struct rtrs_clt_con *con, 459 struct rtrs_clt_io_req *req, 460 struct rtrs_rbuf *rbuf, u32 off, 461 u32 imm, struct ib_send_wr *wr) 462 { 463 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path); 464 enum ib_send_flags flags; 465 struct ib_sge sge; 466 467 if (!req->sg_size) { 468 rtrs_wrn(con->c.path, 469 "Doing RDMA Write failed, no data supplied\n"); 470 return -EINVAL; 471 } 472 473 /* user data and user message in the first list element */ 474 sge.addr = req->iu->dma_addr; 475 sge.length = req->sg_size; 476 sge.lkey = clt_path->s.dev->ib_pd->local_dma_lkey; 477 478 /* 479 * From time to time we have to post signalled sends, 480 * or send queue will fill up and only QP reset can help. 481 */ 482 flags = atomic_inc_return(&con->c.wr_cnt) % clt_path->s.signal_interval ? 483 0 : IB_SEND_SIGNALED; 484 485 ib_dma_sync_single_for_device(clt_path->s.dev->ib_dev, 486 req->iu->dma_addr, 487 req->sg_size, DMA_TO_DEVICE); 488 489 return rtrs_iu_post_rdma_write_imm(&con->c, req->iu, &sge, 1, 490 rbuf->rkey, rbuf->addr + off, 491 imm, flags, wr, NULL); 492 } 493 494 static void process_io_rsp(struct rtrs_clt_path *clt_path, u32 msg_id, 495 s16 errno, bool w_inval) 496 { 497 struct rtrs_clt_io_req *req; 498 499 if (WARN_ON(msg_id >= clt_path->queue_depth)) 500 return; 501 502 req = &clt_path->reqs[msg_id]; 503 /* Drop need_inv if server responded with send with invalidation */ 504 req->need_inv &= !w_inval; 505 complete_rdma_req(req, errno, true, false); 506 } 507 508 static void rtrs_clt_recv_done(struct rtrs_clt_con *con, struct ib_wc *wc) 509 { 510 struct rtrs_iu *iu; 511 int err; 512 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path); 513 514 WARN_ON((clt_path->flags & RTRS_MSG_NEW_RKEY_F) == 0); 515 iu = container_of(wc->wr_cqe, struct rtrs_iu, 516 cqe); 517 err = rtrs_iu_post_recv(&con->c, iu); 518 if (err) { 519 rtrs_err(con->c.path, "post iu failed %d\n", err); 520 rtrs_rdma_error_recovery(con); 521 } 522 } 523 524 static void rtrs_clt_rkey_rsp_done(struct rtrs_clt_con *con, struct ib_wc *wc) 525 { 526 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path); 527 struct rtrs_msg_rkey_rsp *msg; 528 u32 imm_type, imm_payload; 529 bool w_inval = false; 530 struct rtrs_iu *iu; 531 u32 buf_id; 532 int err; 533 534 WARN_ON((clt_path->flags & RTRS_MSG_NEW_RKEY_F) == 0); 535 536 iu = container_of(wc->wr_cqe, struct rtrs_iu, cqe); 537 538 if (wc->byte_len < sizeof(*msg)) { 539 rtrs_err(con->c.path, "rkey response is malformed: size %d\n", 540 wc->byte_len); 541 goto out; 542 } 543 ib_dma_sync_single_for_cpu(clt_path->s.dev->ib_dev, iu->dma_addr, 544 iu->size, DMA_FROM_DEVICE); 545 msg = iu->buf; 546 if (le16_to_cpu(msg->type) != RTRS_MSG_RKEY_RSP) { 547 rtrs_err(clt_path->clt, 548 "rkey response is malformed: type %d\n", 549 le16_to_cpu(msg->type)); 550 goto out; 551 } 552 buf_id = le16_to_cpu(msg->buf_id); 553 if (WARN_ON(buf_id >= clt_path->queue_depth)) 554 goto out; 555 556 rtrs_from_imm(be32_to_cpu(wc->ex.imm_data), &imm_type, &imm_payload); 557 if (imm_type == RTRS_IO_RSP_IMM || 558 imm_type == RTRS_IO_RSP_W_INV_IMM) { 559 u32 msg_id; 560 561 w_inval = (imm_type == RTRS_IO_RSP_W_INV_IMM); 562 rtrs_from_io_rsp_imm(imm_payload, &msg_id, &err); 563 564 if (WARN_ON(buf_id != msg_id)) 565 goto out; 566 clt_path->rbufs[buf_id].rkey = le32_to_cpu(msg->rkey); 567 process_io_rsp(clt_path, msg_id, err, w_inval); 568 } 569 ib_dma_sync_single_for_device(clt_path->s.dev->ib_dev, iu->dma_addr, 570 iu->size, DMA_FROM_DEVICE); 571 return rtrs_clt_recv_done(con, wc); 572 out: 573 rtrs_rdma_error_recovery(con); 574 } 575 576 static void rtrs_clt_rdma_done(struct ib_cq *cq, struct ib_wc *wc); 577 578 static struct ib_cqe io_comp_cqe = { 579 .done = rtrs_clt_rdma_done 580 }; 581 582 /* 583 * Post x2 empty WRs: first is for this RDMA with IMM, 584 * second is for RECV with INV, which happened earlier. 585 */ 586 static int rtrs_post_recv_empty_x2(struct rtrs_con *con, struct ib_cqe *cqe) 587 { 588 struct ib_recv_wr wr_arr[2], *wr; 589 int i; 590 591 memset(wr_arr, 0, sizeof(wr_arr)); 592 for (i = 0; i < ARRAY_SIZE(wr_arr); i++) { 593 wr = &wr_arr[i]; 594 wr->wr_cqe = cqe; 595 if (i) 596 /* Chain backwards */ 597 wr->next = &wr_arr[i - 1]; 598 } 599 600 return ib_post_recv(con->qp, wr, NULL); 601 } 602 603 static void rtrs_clt_rdma_done(struct ib_cq *cq, struct ib_wc *wc) 604 { 605 struct rtrs_clt_con *con = to_clt_con(wc->qp->qp_context); 606 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path); 607 u32 imm_type, imm_payload; 608 bool w_inval = false; 609 int err; 610 611 if (wc->status != IB_WC_SUCCESS) { 612 if (wc->status != IB_WC_WR_FLUSH_ERR) { 613 rtrs_err(clt_path->clt, "RDMA failed: %s\n", 614 ib_wc_status_msg(wc->status)); 615 rtrs_rdma_error_recovery(con); 616 } 617 return; 618 } 619 rtrs_clt_update_wc_stats(con); 620 621 switch (wc->opcode) { 622 case IB_WC_RECV_RDMA_WITH_IMM: 623 /* 624 * post_recv() RDMA write completions of IO reqs (read/write) 625 * and hb 626 */ 627 if (WARN_ON(wc->wr_cqe->done != rtrs_clt_rdma_done)) 628 return; 629 rtrs_from_imm(be32_to_cpu(wc->ex.imm_data), 630 &imm_type, &imm_payload); 631 if (imm_type == RTRS_IO_RSP_IMM || 632 imm_type == RTRS_IO_RSP_W_INV_IMM) { 633 u32 msg_id; 634 635 w_inval = (imm_type == RTRS_IO_RSP_W_INV_IMM); 636 rtrs_from_io_rsp_imm(imm_payload, &msg_id, &err); 637 638 process_io_rsp(clt_path, msg_id, err, w_inval); 639 } else if (imm_type == RTRS_HB_MSG_IMM) { 640 WARN_ON(con->c.cid); 641 rtrs_send_hb_ack(&clt_path->s); 642 if (clt_path->flags & RTRS_MSG_NEW_RKEY_F) 643 return rtrs_clt_recv_done(con, wc); 644 } else if (imm_type == RTRS_HB_ACK_IMM) { 645 WARN_ON(con->c.cid); 646 clt_path->s.hb_missed_cnt = 0; 647 clt_path->s.hb_cur_latency = 648 ktime_sub(ktime_get(), clt_path->s.hb_last_sent); 649 if (clt_path->flags & RTRS_MSG_NEW_RKEY_F) 650 return rtrs_clt_recv_done(con, wc); 651 } else { 652 rtrs_wrn(con->c.path, "Unknown IMM type %u\n", 653 imm_type); 654 } 655 if (w_inval) 656 /* 657 * Post x2 empty WRs: first is for this RDMA with IMM, 658 * second is for RECV with INV, which happened earlier. 659 */ 660 err = rtrs_post_recv_empty_x2(&con->c, &io_comp_cqe); 661 else 662 err = rtrs_post_recv_empty(&con->c, &io_comp_cqe); 663 if (err) { 664 rtrs_err(con->c.path, "rtrs_post_recv_empty(): %d\n", 665 err); 666 rtrs_rdma_error_recovery(con); 667 } 668 break; 669 case IB_WC_RECV: 670 /* 671 * Key invalidations from server side 672 */ 673 WARN_ON(!(wc->wc_flags & IB_WC_WITH_INVALIDATE || 674 wc->wc_flags & IB_WC_WITH_IMM)); 675 WARN_ON(wc->wr_cqe->done != rtrs_clt_rdma_done); 676 if (clt_path->flags & RTRS_MSG_NEW_RKEY_F) { 677 if (wc->wc_flags & IB_WC_WITH_INVALIDATE) 678 return rtrs_clt_recv_done(con, wc); 679 680 return rtrs_clt_rkey_rsp_done(con, wc); 681 } 682 break; 683 case IB_WC_RDMA_WRITE: 684 /* 685 * post_send() RDMA write completions of IO reqs (read/write) 686 * and hb. 687 */ 688 break; 689 690 default: 691 rtrs_wrn(clt_path->clt, "Unexpected WC type: %d\n", wc->opcode); 692 return; 693 } 694 } 695 696 static int post_recv_io(struct rtrs_clt_con *con, size_t q_size) 697 { 698 int err, i; 699 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path); 700 701 for (i = 0; i < q_size; i++) { 702 if (clt_path->flags & RTRS_MSG_NEW_RKEY_F) { 703 struct rtrs_iu *iu = &con->rsp_ius[i]; 704 705 err = rtrs_iu_post_recv(&con->c, iu); 706 } else { 707 err = rtrs_post_recv_empty(&con->c, &io_comp_cqe); 708 } 709 if (err) 710 return err; 711 } 712 713 return 0; 714 } 715 716 static int post_recv_path(struct rtrs_clt_path *clt_path) 717 { 718 size_t q_size = 0; 719 int err, cid; 720 721 for (cid = 0; cid < clt_path->s.con_num; cid++) { 722 if (cid == 0) 723 q_size = SERVICE_CON_QUEUE_DEPTH; 724 else 725 q_size = clt_path->queue_depth; 726 727 /* 728 * x2 for RDMA read responses + FR key invalidations, 729 * RDMA writes do not require any FR registrations. 730 */ 731 q_size *= 2; 732 733 err = post_recv_io(to_clt_con(clt_path->s.con[cid]), q_size); 734 if (err) { 735 rtrs_err(clt_path->clt, "post_recv_io(), err: %d\n", 736 err); 737 return err; 738 } 739 } 740 741 return 0; 742 } 743 744 struct path_it { 745 int i; 746 struct list_head skip_list; 747 struct rtrs_clt_sess *clt; 748 struct rtrs_clt_path *(*next_path)(struct path_it *it); 749 }; 750 751 /* 752 * rtrs_clt_get_next_path_or_null - get clt path from the list or return NULL 753 * @head: the head for the list. 754 * @clt_path: The element to take the next clt_path from. 755 * 756 * Next clt path returned in round-robin fashion, i.e. head will be skipped, 757 * but if list is observed as empty, NULL will be returned. 758 * 759 * This function may safely run concurrently with the _rcu list-mutation 760 * primitives such as list_add_rcu() as long as it's guarded by rcu_read_lock(). 761 */ 762 static inline struct rtrs_clt_path * 763 rtrs_clt_get_next_path_or_null(struct list_head *head, struct rtrs_clt_path *clt_path) 764 { 765 return list_next_or_null_rcu(head, &clt_path->s.entry, typeof(*clt_path), s.entry) ?: 766 list_next_or_null_rcu(head, 767 READ_ONCE((&clt_path->s.entry)->next), 768 typeof(*clt_path), s.entry); 769 } 770 771 /** 772 * get_next_path_rr() - Returns path in round-robin fashion. 773 * @it: the path pointer 774 * 775 * Related to @MP_POLICY_RR 776 * 777 * Locks: 778 * rcu_read_lock() must be hold. 779 */ 780 static struct rtrs_clt_path *get_next_path_rr(struct path_it *it) 781 { 782 struct rtrs_clt_path __rcu **ppcpu_path; 783 struct rtrs_clt_path *path; 784 struct rtrs_clt_sess *clt; 785 786 clt = it->clt; 787 788 /* 789 * Here we use two RCU objects: @paths_list and @pcpu_path 790 * pointer. See rtrs_clt_remove_path_from_arr() for details 791 * how that is handled. 792 */ 793 794 ppcpu_path = this_cpu_ptr(clt->pcpu_path); 795 path = rcu_dereference(*ppcpu_path); 796 if (!path) 797 path = list_first_or_null_rcu(&clt->paths_list, 798 typeof(*path), s.entry); 799 else 800 path = rtrs_clt_get_next_path_or_null(&clt->paths_list, path); 801 802 rcu_assign_pointer(*ppcpu_path, path); 803 804 return path; 805 } 806 807 /** 808 * get_next_path_min_inflight() - Returns path with minimal inflight count. 809 * @it: the path pointer 810 * 811 * Related to @MP_POLICY_MIN_INFLIGHT 812 * 813 * Locks: 814 * rcu_read_lock() must be hold. 815 */ 816 static struct rtrs_clt_path *get_next_path_min_inflight(struct path_it *it) 817 { 818 struct rtrs_clt_path *min_path = NULL; 819 struct rtrs_clt_sess *clt = it->clt; 820 struct rtrs_clt_path *clt_path; 821 int min_inflight = INT_MAX; 822 int inflight; 823 824 list_for_each_entry_rcu(clt_path, &clt->paths_list, s.entry) { 825 if (READ_ONCE(clt_path->state) != RTRS_CLT_CONNECTED) 826 continue; 827 828 if (!list_empty(raw_cpu_ptr(clt_path->mp_skip_entry))) 829 continue; 830 831 inflight = atomic_read(&clt_path->stats->inflight); 832 833 if (inflight < min_inflight) { 834 min_inflight = inflight; 835 min_path = clt_path; 836 } 837 } 838 839 /* 840 * add the path to the skip list, so that next time we can get 841 * a different one 842 */ 843 if (min_path) 844 list_add(raw_cpu_ptr(min_path->mp_skip_entry), &it->skip_list); 845 846 return min_path; 847 } 848 849 /** 850 * get_next_path_min_latency() - Returns path with minimal latency. 851 * @it: the path pointer 852 * 853 * Return: a path with the lowest latency or NULL if all paths are tried 854 * 855 * Locks: 856 * rcu_read_lock() must be hold. 857 * 858 * Related to @MP_POLICY_MIN_LATENCY 859 * 860 * This DOES skip an already-tried path. 861 * There is a skip-list to skip a path if the path has tried but failed. 862 * It will try the minimum latency path and then the second minimum latency 863 * path and so on. Finally it will return NULL if all paths are tried. 864 * Therefore the caller MUST check the returned 865 * path is NULL and trigger the IO error. 866 */ 867 static struct rtrs_clt_path *get_next_path_min_latency(struct path_it *it) 868 { 869 struct rtrs_clt_path *min_path = NULL; 870 struct rtrs_clt_sess *clt = it->clt; 871 struct rtrs_clt_path *clt_path; 872 ktime_t min_latency = KTIME_MAX; 873 ktime_t latency; 874 875 list_for_each_entry_rcu(clt_path, &clt->paths_list, s.entry) { 876 if (READ_ONCE(clt_path->state) != RTRS_CLT_CONNECTED) 877 continue; 878 879 if (!list_empty(raw_cpu_ptr(clt_path->mp_skip_entry))) 880 continue; 881 882 latency = clt_path->s.hb_cur_latency; 883 884 if (latency < min_latency) { 885 min_latency = latency; 886 min_path = clt_path; 887 } 888 } 889 890 /* 891 * add the path to the skip list, so that next time we can get 892 * a different one 893 */ 894 if (min_path) 895 list_add(raw_cpu_ptr(min_path->mp_skip_entry), &it->skip_list); 896 897 return min_path; 898 } 899 900 static inline void path_it_init(struct path_it *it, struct rtrs_clt_sess *clt) 901 { 902 INIT_LIST_HEAD(&it->skip_list); 903 it->clt = clt; 904 it->i = 0; 905 906 if (clt->mp_policy == MP_POLICY_RR) 907 it->next_path = get_next_path_rr; 908 else if (clt->mp_policy == MP_POLICY_MIN_INFLIGHT) 909 it->next_path = get_next_path_min_inflight; 910 else 911 it->next_path = get_next_path_min_latency; 912 } 913 914 static inline void path_it_deinit(struct path_it *it) 915 { 916 struct list_head *skip, *tmp; 917 /* 918 * The skip_list is used only for the MIN_INFLIGHT and MIN_LATENCY policies. 919 * We need to remove paths from it, so that next IO can insert 920 * paths (->mp_skip_entry) into a skip_list again. 921 */ 922 list_for_each_safe(skip, tmp, &it->skip_list) 923 list_del_init(skip); 924 } 925 926 /** 927 * rtrs_clt_init_req() - Initialize an rtrs_clt_io_req holding information 928 * about an inflight IO. 929 * The user buffer holding user control message (not data) is copied into 930 * the corresponding buffer of rtrs_iu (req->iu->buf), which later on will 931 * also hold the control message of rtrs. 932 * @req: an io request holding information about IO. 933 * @clt_path: client path 934 * @conf: conformation callback function to notify upper layer. 935 * @permit: permit for allocation of RDMA remote buffer 936 * @priv: private pointer 937 * @vec: kernel vector containing control message 938 * @usr_len: length of the user message 939 * @sg: scater list for IO data 940 * @sg_cnt: number of scater list entries 941 * @data_len: length of the IO data 942 * @dir: direction of the IO. 943 */ 944 static void rtrs_clt_init_req(struct rtrs_clt_io_req *req, 945 struct rtrs_clt_path *clt_path, 946 void (*conf)(void *priv, int errno), 947 struct rtrs_permit *permit, void *priv, 948 const struct kvec *vec, size_t usr_len, 949 struct scatterlist *sg, size_t sg_cnt, 950 size_t data_len, int dir) 951 { 952 struct iov_iter iter; 953 size_t len; 954 955 req->permit = permit; 956 req->in_use = true; 957 req->usr_len = usr_len; 958 req->data_len = data_len; 959 req->sglist = sg; 960 req->sg_cnt = sg_cnt; 961 req->priv = priv; 962 req->dir = dir; 963 req->con = rtrs_permit_to_clt_con(clt_path, permit); 964 req->conf = conf; 965 req->need_inv = false; 966 req->need_inv_comp = false; 967 req->inv_errno = 0; 968 refcount_set(&req->ref, 1); 969 req->mp_policy = clt_path->clt->mp_policy; 970 971 iov_iter_kvec(&iter, ITER_SOURCE, vec, 1, usr_len); 972 len = _copy_from_iter(req->iu->buf, usr_len, &iter); 973 WARN_ON(len != usr_len); 974 975 reinit_completion(&req->inv_comp); 976 } 977 978 static struct rtrs_clt_io_req * 979 rtrs_clt_get_req(struct rtrs_clt_path *clt_path, 980 void (*conf)(void *priv, int errno), 981 struct rtrs_permit *permit, void *priv, 982 const struct kvec *vec, size_t usr_len, 983 struct scatterlist *sg, size_t sg_cnt, 984 size_t data_len, int dir) 985 { 986 struct rtrs_clt_io_req *req; 987 988 req = &clt_path->reqs[permit->mem_id]; 989 rtrs_clt_init_req(req, clt_path, conf, permit, priv, vec, usr_len, 990 sg, sg_cnt, data_len, dir); 991 return req; 992 } 993 994 static struct rtrs_clt_io_req * 995 rtrs_clt_get_copy_req(struct rtrs_clt_path *alive_path, 996 struct rtrs_clt_io_req *fail_req) 997 { 998 struct rtrs_clt_io_req *req; 999 struct kvec vec = { 1000 .iov_base = fail_req->iu->buf, 1001 .iov_len = fail_req->usr_len 1002 }; 1003 1004 req = &alive_path->reqs[fail_req->permit->mem_id]; 1005 rtrs_clt_init_req(req, alive_path, fail_req->conf, fail_req->permit, 1006 fail_req->priv, &vec, fail_req->usr_len, 1007 fail_req->sglist, fail_req->sg_cnt, 1008 fail_req->data_len, fail_req->dir); 1009 return req; 1010 } 1011 1012 static int rtrs_post_rdma_write_sg(struct rtrs_clt_con *con, 1013 struct rtrs_clt_io_req *req, 1014 struct rtrs_rbuf *rbuf, bool fr_en, 1015 u32 count, u32 size, u32 imm, 1016 struct ib_send_wr *wr, 1017 struct ib_send_wr *tail) 1018 { 1019 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path); 1020 struct ib_sge *sge = req->sge; 1021 enum ib_send_flags flags; 1022 struct scatterlist *sg; 1023 size_t num_sge; 1024 int i; 1025 struct ib_send_wr *ptail = NULL; 1026 1027 if (fr_en) { 1028 i = 0; 1029 sge[i].addr = req->mr->iova; 1030 sge[i].length = req->mr->length; 1031 sge[i].lkey = req->mr->lkey; 1032 i++; 1033 num_sge = 2; 1034 ptail = tail; 1035 } else { 1036 for_each_sg(req->sglist, sg, count, i) { 1037 sge[i].addr = sg_dma_address(sg); 1038 sge[i].length = sg_dma_len(sg); 1039 sge[i].lkey = clt_path->s.dev->ib_pd->local_dma_lkey; 1040 } 1041 num_sge = 1 + count; 1042 } 1043 sge[i].addr = req->iu->dma_addr; 1044 sge[i].length = size; 1045 sge[i].lkey = clt_path->s.dev->ib_pd->local_dma_lkey; 1046 1047 /* 1048 * From time to time we have to post signalled sends, 1049 * or send queue will fill up and only QP reset can help. 1050 */ 1051 flags = atomic_inc_return(&con->c.wr_cnt) % clt_path->s.signal_interval ? 1052 0 : IB_SEND_SIGNALED; 1053 1054 ib_dma_sync_single_for_device(clt_path->s.dev->ib_dev, 1055 req->iu->dma_addr, 1056 size, DMA_TO_DEVICE); 1057 1058 return rtrs_iu_post_rdma_write_imm(&con->c, req->iu, sge, num_sge, 1059 rbuf->rkey, rbuf->addr, imm, 1060 flags, wr, ptail); 1061 } 1062 1063 static int rtrs_map_sg_fr(struct rtrs_clt_io_req *req, size_t count) 1064 { 1065 int nr; 1066 1067 /* Align the MR to a 4K page size to match the block virt boundary */ 1068 nr = ib_map_mr_sg(req->mr, req->sglist, count, NULL, SZ_4K); 1069 if (nr != count) 1070 return nr < 0 ? nr : -EINVAL; 1071 ib_update_fast_reg_key(req->mr, ib_inc_rkey(req->mr->rkey)); 1072 1073 return nr; 1074 } 1075 1076 static int rtrs_clt_write_req(struct rtrs_clt_io_req *req) 1077 { 1078 struct rtrs_clt_con *con = req->con; 1079 struct rtrs_path *s = con->c.path; 1080 struct rtrs_clt_path *clt_path = to_clt_path(s); 1081 struct rtrs_msg_rdma_write *msg; 1082 1083 struct rtrs_rbuf *rbuf; 1084 int ret, count = 0; 1085 u32 imm, buf_id; 1086 struct ib_reg_wr rwr; 1087 struct ib_send_wr inv_wr; 1088 struct ib_send_wr *wr = NULL; 1089 bool fr_en = false; 1090 1091 const size_t tsize = sizeof(*msg) + req->data_len + req->usr_len; 1092 1093 if (tsize > clt_path->chunk_size) { 1094 rtrs_wrn(s, "Write request failed, size too big %zu > %d\n", 1095 tsize, clt_path->chunk_size); 1096 return -EMSGSIZE; 1097 } 1098 if (req->sg_cnt) { 1099 count = ib_dma_map_sg(clt_path->s.dev->ib_dev, req->sglist, 1100 req->sg_cnt, req->dir); 1101 if (!count) { 1102 rtrs_wrn(s, "Write request failed, map failed\n"); 1103 return -EINVAL; 1104 } 1105 } 1106 /* put rtrs msg after sg and user message */ 1107 msg = req->iu->buf + req->usr_len; 1108 msg->type = cpu_to_le16(RTRS_MSG_WRITE); 1109 msg->usr_len = cpu_to_le16(req->usr_len); 1110 1111 /* rtrs message on server side will be after user data and message */ 1112 imm = req->permit->mem_off + req->data_len + req->usr_len; 1113 imm = rtrs_to_io_req_imm(imm); 1114 buf_id = req->permit->mem_id; 1115 req->sg_size = tsize; 1116 rbuf = &clt_path->rbufs[buf_id]; 1117 1118 if (count) { 1119 ret = rtrs_map_sg_fr(req, count); 1120 if (ret < 0) { 1121 rtrs_err_rl(s, 1122 "Write request failed, failed to map fast reg. data, err: %d\n", 1123 ret); 1124 ib_dma_unmap_sg(clt_path->s.dev->ib_dev, req->sglist, 1125 req->sg_cnt, req->dir); 1126 return ret; 1127 } 1128 inv_wr = (struct ib_send_wr) { 1129 .opcode = IB_WR_LOCAL_INV, 1130 .wr_cqe = &req->inv_cqe, 1131 .send_flags = IB_SEND_SIGNALED, 1132 .ex.invalidate_rkey = req->mr->rkey, 1133 }; 1134 req->inv_cqe.done = rtrs_clt_inv_rkey_done; 1135 rwr = (struct ib_reg_wr) { 1136 .wr.opcode = IB_WR_REG_MR, 1137 .wr.wr_cqe = &fast_reg_cqe, 1138 .mr = req->mr, 1139 .key = req->mr->rkey, 1140 .access = (IB_ACCESS_LOCAL_WRITE), 1141 }; 1142 wr = &rwr.wr; 1143 fr_en = true; 1144 refcount_inc(&req->ref); 1145 } 1146 /* 1147 * Update stats now, after request is successfully sent it is not 1148 * safe anymore to touch it. 1149 */ 1150 rtrs_clt_update_all_stats(req, WRITE); 1151 1152 ret = rtrs_post_rdma_write_sg(req->con, req, rbuf, fr_en, count, 1153 req->usr_len + sizeof(*msg), 1154 imm, wr, &inv_wr); 1155 if (ret) { 1156 rtrs_err_rl(s, 1157 "Write request failed: error=%d path=%s [%s:%u]\n", 1158 ret, kobject_name(&clt_path->kobj), clt_path->hca_name, 1159 clt_path->hca_port); 1160 if (req->mp_policy == MP_POLICY_MIN_INFLIGHT) 1161 atomic_dec(&clt_path->stats->inflight); 1162 if (req->sg_cnt) 1163 ib_dma_unmap_sg(clt_path->s.dev->ib_dev, req->sglist, 1164 req->sg_cnt, req->dir); 1165 } 1166 1167 return ret; 1168 } 1169 1170 static int rtrs_clt_read_req(struct rtrs_clt_io_req *req) 1171 { 1172 struct rtrs_clt_con *con = req->con; 1173 struct rtrs_path *s = con->c.path; 1174 struct rtrs_clt_path *clt_path = to_clt_path(s); 1175 struct rtrs_msg_rdma_read *msg; 1176 struct rtrs_ib_dev *dev = clt_path->s.dev; 1177 1178 struct ib_reg_wr rwr; 1179 struct ib_send_wr *wr = NULL; 1180 1181 int ret, count = 0; 1182 u32 imm, buf_id; 1183 1184 const size_t tsize = sizeof(*msg) + req->data_len + req->usr_len; 1185 1186 if (tsize > clt_path->chunk_size) { 1187 rtrs_wrn(s, 1188 "Read request failed, message size is %zu, bigger than CHUNK_SIZE %d\n", 1189 tsize, clt_path->chunk_size); 1190 return -EMSGSIZE; 1191 } 1192 1193 if (req->sg_cnt) { 1194 count = ib_dma_map_sg(dev->ib_dev, req->sglist, req->sg_cnt, 1195 req->dir); 1196 if (!count) { 1197 rtrs_wrn(s, 1198 "Read request failed, dma map failed\n"); 1199 return -EINVAL; 1200 } 1201 } 1202 /* put our message into req->buf after user message*/ 1203 msg = req->iu->buf + req->usr_len; 1204 msg->type = cpu_to_le16(RTRS_MSG_READ); 1205 msg->usr_len = cpu_to_le16(req->usr_len); 1206 1207 if (count) { 1208 ret = rtrs_map_sg_fr(req, count); 1209 if (ret < 0) { 1210 rtrs_err_rl(s, 1211 "Read request failed, failed to map fast reg. data, err: %d\n", 1212 ret); 1213 ib_dma_unmap_sg(dev->ib_dev, req->sglist, req->sg_cnt, 1214 req->dir); 1215 return ret; 1216 } 1217 rwr = (struct ib_reg_wr) { 1218 .wr.opcode = IB_WR_REG_MR, 1219 .wr.wr_cqe = &fast_reg_cqe, 1220 .mr = req->mr, 1221 .key = req->mr->rkey, 1222 .access = (IB_ACCESS_LOCAL_WRITE | 1223 IB_ACCESS_REMOTE_WRITE), 1224 }; 1225 wr = &rwr.wr; 1226 1227 msg->sg_cnt = cpu_to_le16(1); 1228 msg->flags = cpu_to_le16(RTRS_MSG_NEED_INVAL_F); 1229 1230 msg->desc[0].addr = cpu_to_le64(req->mr->iova); 1231 msg->desc[0].key = cpu_to_le32(req->mr->rkey); 1232 msg->desc[0].len = cpu_to_le32(req->mr->length); 1233 1234 /* Further invalidation is required */ 1235 req->need_inv = !!RTRS_MSG_NEED_INVAL_F; 1236 1237 } else { 1238 msg->sg_cnt = 0; 1239 msg->flags = 0; 1240 } 1241 /* 1242 * rtrs message will be after the space reserved for disk data and 1243 * user message 1244 */ 1245 imm = req->permit->mem_off + req->data_len + req->usr_len; 1246 imm = rtrs_to_io_req_imm(imm); 1247 buf_id = req->permit->mem_id; 1248 1249 req->sg_size = sizeof(*msg); 1250 req->sg_size += le16_to_cpu(msg->sg_cnt) * sizeof(struct rtrs_sg_desc); 1251 req->sg_size += req->usr_len; 1252 1253 /* 1254 * Update stats now, after request is successfully sent it is not 1255 * safe anymore to touch it. 1256 */ 1257 rtrs_clt_update_all_stats(req, READ); 1258 1259 ret = rtrs_post_send_rdma(req->con, req, &clt_path->rbufs[buf_id], 1260 req->data_len, imm, wr); 1261 if (ret) { 1262 rtrs_err_rl(s, 1263 "Read request failed: error=%d path=%s [%s:%u]\n", 1264 ret, kobject_name(&clt_path->kobj), clt_path->hca_name, 1265 clt_path->hca_port); 1266 if (req->mp_policy == MP_POLICY_MIN_INFLIGHT) 1267 atomic_dec(&clt_path->stats->inflight); 1268 req->need_inv = false; 1269 if (req->sg_cnt) 1270 ib_dma_unmap_sg(dev->ib_dev, req->sglist, 1271 req->sg_cnt, req->dir); 1272 } 1273 1274 return ret; 1275 } 1276 1277 /** 1278 * rtrs_clt_failover_req() - Try to find an active path for a failed request 1279 * @clt: clt context 1280 * @fail_req: a failed io request. 1281 */ 1282 static int rtrs_clt_failover_req(struct rtrs_clt_sess *clt, 1283 struct rtrs_clt_io_req *fail_req) 1284 { 1285 struct rtrs_clt_path *alive_path; 1286 struct rtrs_clt_io_req *req; 1287 int err = -ECONNABORTED; 1288 struct path_it it; 1289 1290 rcu_read_lock(); 1291 for (path_it_init(&it, clt); 1292 (alive_path = it.next_path(&it)) && it.i < it.clt->paths_num; 1293 it.i++) { 1294 if (READ_ONCE(alive_path->state) != RTRS_CLT_CONNECTED) 1295 continue; 1296 req = rtrs_clt_get_copy_req(alive_path, fail_req); 1297 if (req->dir == DMA_TO_DEVICE) 1298 err = rtrs_clt_write_req(req); 1299 else 1300 err = rtrs_clt_read_req(req); 1301 if (err) { 1302 req->in_use = false; 1303 continue; 1304 } 1305 /* Success path */ 1306 rtrs_clt_inc_failover_cnt(alive_path->stats); 1307 break; 1308 } 1309 path_it_deinit(&it); 1310 rcu_read_unlock(); 1311 1312 return err; 1313 } 1314 1315 static void fail_all_outstanding_reqs(struct rtrs_clt_path *clt_path) 1316 { 1317 struct rtrs_clt_sess *clt = clt_path->clt; 1318 struct rtrs_clt_io_req *req; 1319 int i, err; 1320 1321 if (!clt_path->reqs) 1322 return; 1323 for (i = 0; i < clt_path->queue_depth; ++i) { 1324 req = &clt_path->reqs[i]; 1325 if (!req->in_use) 1326 continue; 1327 1328 /* 1329 * Safely (without notification) complete failed request. 1330 * After completion this request is still useble and can 1331 * be failovered to another path. 1332 */ 1333 complete_rdma_req(req, -ECONNABORTED, false, true); 1334 1335 err = rtrs_clt_failover_req(clt, req); 1336 if (err) 1337 /* Failover failed, notify anyway */ 1338 req->conf(req->priv, err); 1339 } 1340 } 1341 1342 static void free_path_reqs(struct rtrs_clt_path *clt_path) 1343 { 1344 struct rtrs_clt_io_req *req; 1345 int i; 1346 1347 if (!clt_path->reqs) 1348 return; 1349 for (i = 0; i < clt_path->queue_depth; ++i) { 1350 req = &clt_path->reqs[i]; 1351 if (req->mr) 1352 ib_dereg_mr(req->mr); 1353 kfree(req->sge); 1354 rtrs_iu_free(req->iu, clt_path->s.dev->ib_dev, 1); 1355 } 1356 kfree(clt_path->reqs); 1357 clt_path->reqs = NULL; 1358 } 1359 1360 static int alloc_path_reqs(struct rtrs_clt_path *clt_path) 1361 { 1362 struct rtrs_clt_io_req *req; 1363 int i, err = -ENOMEM; 1364 1365 clt_path->reqs = kcalloc(clt_path->queue_depth, 1366 sizeof(*clt_path->reqs), 1367 GFP_KERNEL); 1368 if (!clt_path->reqs) 1369 return -ENOMEM; 1370 1371 for (i = 0; i < clt_path->queue_depth; ++i) { 1372 req = &clt_path->reqs[i]; 1373 req->iu = rtrs_iu_alloc(1, clt_path->max_hdr_size, GFP_KERNEL, 1374 clt_path->s.dev->ib_dev, 1375 DMA_TO_DEVICE, 1376 rtrs_clt_rdma_done); 1377 if (!req->iu) 1378 goto out; 1379 1380 req->sge = kcalloc(2, sizeof(*req->sge), GFP_KERNEL); 1381 if (!req->sge) 1382 goto out; 1383 1384 req->mr = ib_alloc_mr(clt_path->s.dev->ib_pd, 1385 IB_MR_TYPE_MEM_REG, 1386 clt_path->max_pages_per_mr); 1387 if (IS_ERR(req->mr)) { 1388 err = PTR_ERR(req->mr); 1389 req->mr = NULL; 1390 pr_err("Failed to alloc clt_path->max_pages_per_mr %d\n", 1391 clt_path->max_pages_per_mr); 1392 goto out; 1393 } 1394 1395 init_completion(&req->inv_comp); 1396 } 1397 1398 return 0; 1399 1400 out: 1401 free_path_reqs(clt_path); 1402 1403 return err; 1404 } 1405 1406 static int alloc_permits(struct rtrs_clt_sess *clt) 1407 { 1408 unsigned int chunk_bits; 1409 int err, i; 1410 1411 clt->permits_map = bitmap_zalloc(clt->queue_depth, GFP_KERNEL); 1412 if (!clt->permits_map) { 1413 err = -ENOMEM; 1414 goto out_err; 1415 } 1416 clt->permits = kcalloc(clt->queue_depth, permit_size(clt), GFP_KERNEL); 1417 if (!clt->permits) { 1418 err = -ENOMEM; 1419 goto err_map; 1420 } 1421 chunk_bits = ilog2(clt->queue_depth - 1) + 1; 1422 for (i = 0; i < clt->queue_depth; i++) { 1423 struct rtrs_permit *permit; 1424 1425 permit = get_permit(clt, i); 1426 permit->mem_id = i; 1427 permit->mem_off = i << (MAX_IMM_PAYL_BITS - chunk_bits); 1428 } 1429 1430 return 0; 1431 1432 err_map: 1433 bitmap_free(clt->permits_map); 1434 clt->permits_map = NULL; 1435 out_err: 1436 return err; 1437 } 1438 1439 static void free_permits(struct rtrs_clt_sess *clt) 1440 { 1441 if (clt->permits_map) 1442 wait_event(clt->permits_wait, 1443 bitmap_empty(clt->permits_map, clt->queue_depth)); 1444 1445 bitmap_free(clt->permits_map); 1446 clt->permits_map = NULL; 1447 kfree(clt->permits); 1448 clt->permits = NULL; 1449 } 1450 1451 static void query_fast_reg_mode(struct rtrs_clt_path *clt_path) 1452 { 1453 struct ib_device *ib_dev; 1454 u64 max_pages_per_mr; 1455 int mr_page_shift; 1456 1457 ib_dev = clt_path->s.dev->ib_dev; 1458 1459 /* 1460 * Use the smallest page size supported by the HCA, down to a 1461 * minimum of 4096 bytes. We're unlikely to build large sglists 1462 * out of smaller entries. 1463 */ 1464 mr_page_shift = max(12, ffs(ib_dev->attrs.page_size_cap) - 1); 1465 max_pages_per_mr = ib_dev->attrs.max_mr_size; 1466 do_div(max_pages_per_mr, (1ull << mr_page_shift)); 1467 clt_path->max_pages_per_mr = 1468 min3(clt_path->max_pages_per_mr, (u32)max_pages_per_mr, 1469 ib_dev->attrs.max_fast_reg_page_list_len); 1470 clt_path->clt->max_segments = 1471 min(clt_path->max_pages_per_mr, clt_path->clt->max_segments); 1472 } 1473 1474 static bool rtrs_clt_change_state_get_old(struct rtrs_clt_path *clt_path, 1475 enum rtrs_clt_state new_state, 1476 enum rtrs_clt_state *old_state) 1477 { 1478 bool changed; 1479 1480 spin_lock_irq(&clt_path->state_wq.lock); 1481 if (old_state) 1482 *old_state = clt_path->state; 1483 changed = rtrs_clt_change_state(clt_path, new_state); 1484 spin_unlock_irq(&clt_path->state_wq.lock); 1485 1486 return changed; 1487 } 1488 1489 static void rtrs_clt_hb_err_handler(struct rtrs_con *c) 1490 { 1491 struct rtrs_clt_con *con = container_of(c, typeof(*con), c); 1492 1493 rtrs_rdma_error_recovery(con); 1494 } 1495 1496 static void rtrs_clt_init_hb(struct rtrs_clt_path *clt_path) 1497 { 1498 rtrs_init_hb(&clt_path->s, &io_comp_cqe, 1499 RTRS_HB_INTERVAL_MS, 1500 RTRS_HB_MISSED_MAX, 1501 rtrs_clt_hb_err_handler, 1502 rtrs_wq); 1503 } 1504 1505 static void rtrs_clt_reconnect_work(struct work_struct *work); 1506 static void rtrs_clt_close_work(struct work_struct *work); 1507 1508 static void rtrs_clt_err_recovery_work(struct work_struct *work) 1509 { 1510 struct rtrs_clt_path *clt_path; 1511 struct rtrs_clt_sess *clt; 1512 int delay_ms; 1513 1514 clt_path = container_of(work, struct rtrs_clt_path, err_recovery_work); 1515 clt = clt_path->clt; 1516 delay_ms = clt->reconnect_delay_sec * 1000; 1517 rtrs_clt_stop_and_destroy_conns(clt_path); 1518 queue_delayed_work(rtrs_wq, &clt_path->reconnect_dwork, 1519 msecs_to_jiffies(delay_ms + 1520 get_random_u32_below(RTRS_RECONNECT_SEED))); 1521 } 1522 1523 static struct rtrs_clt_path *alloc_path(struct rtrs_clt_sess *clt, 1524 const struct rtrs_addr *path, 1525 size_t con_num, u32 nr_poll_queues) 1526 { 1527 struct rtrs_clt_path *clt_path; 1528 int err = -ENOMEM; 1529 int cpu; 1530 size_t total_con; 1531 1532 clt_path = kzalloc(sizeof(*clt_path), GFP_KERNEL); 1533 if (!clt_path) 1534 goto err; 1535 1536 /* 1537 * irqmode and poll 1538 * +1: Extra connection for user messages 1539 */ 1540 total_con = con_num + nr_poll_queues + 1; 1541 clt_path->s.con = kcalloc(total_con, sizeof(*clt_path->s.con), 1542 GFP_KERNEL); 1543 if (!clt_path->s.con) 1544 goto err_free_path; 1545 1546 clt_path->s.con_num = total_con; 1547 clt_path->s.irq_con_num = con_num + 1; 1548 1549 clt_path->stats = kzalloc(sizeof(*clt_path->stats), GFP_KERNEL); 1550 if (!clt_path->stats) 1551 goto err_free_con; 1552 1553 mutex_init(&clt_path->init_mutex); 1554 uuid_gen(&clt_path->s.uuid); 1555 memcpy(&clt_path->s.dst_addr, path->dst, 1556 rdma_addr_size((struct sockaddr *)path->dst)); 1557 1558 /* 1559 * rdma_resolve_addr() passes src_addr to cma_bind_addr, which 1560 * checks the sa_family to be non-zero. If user passed src_addr=NULL 1561 * the sess->src_addr will contain only zeros, which is then fine. 1562 */ 1563 if (path->src) 1564 memcpy(&clt_path->s.src_addr, path->src, 1565 rdma_addr_size((struct sockaddr *)path->src)); 1566 strscpy(clt_path->s.sessname, clt->sessname, 1567 sizeof(clt_path->s.sessname)); 1568 clt_path->clt = clt; 1569 clt_path->max_pages_per_mr = RTRS_MAX_SEGMENTS; 1570 init_waitqueue_head(&clt_path->state_wq); 1571 clt_path->state = RTRS_CLT_CONNECTING; 1572 atomic_set(&clt_path->connected_cnt, 0); 1573 INIT_WORK(&clt_path->close_work, rtrs_clt_close_work); 1574 INIT_WORK(&clt_path->err_recovery_work, rtrs_clt_err_recovery_work); 1575 INIT_DELAYED_WORK(&clt_path->reconnect_dwork, rtrs_clt_reconnect_work); 1576 rtrs_clt_init_hb(clt_path); 1577 1578 clt_path->mp_skip_entry = alloc_percpu(typeof(*clt_path->mp_skip_entry)); 1579 if (!clt_path->mp_skip_entry) 1580 goto err_free_stats; 1581 1582 for_each_possible_cpu(cpu) 1583 INIT_LIST_HEAD(per_cpu_ptr(clt_path->mp_skip_entry, cpu)); 1584 1585 err = rtrs_clt_init_stats(clt_path->stats); 1586 if (err) 1587 goto err_free_percpu; 1588 1589 return clt_path; 1590 1591 err_free_percpu: 1592 free_percpu(clt_path->mp_skip_entry); 1593 err_free_stats: 1594 kfree(clt_path->stats); 1595 err_free_con: 1596 kfree(clt_path->s.con); 1597 err_free_path: 1598 kfree(clt_path); 1599 err: 1600 return ERR_PTR(err); 1601 } 1602 1603 void free_path(struct rtrs_clt_path *clt_path) 1604 { 1605 free_percpu(clt_path->mp_skip_entry); 1606 mutex_destroy(&clt_path->init_mutex); 1607 kfree(clt_path->s.con); 1608 kfree(clt_path->rbufs); 1609 kfree(clt_path); 1610 } 1611 1612 static int create_con(struct rtrs_clt_path *clt_path, unsigned int cid) 1613 { 1614 struct rtrs_clt_con *con; 1615 1616 con = kzalloc(sizeof(*con), GFP_KERNEL); 1617 if (!con) 1618 return -ENOMEM; 1619 1620 /* Map first two connections to the first CPU */ 1621 con->cpu = (cid ? cid - 1 : 0) % nr_cpu_ids; 1622 con->c.cid = cid; 1623 con->c.path = &clt_path->s; 1624 /* Align with srv, init as 1 */ 1625 atomic_set(&con->c.wr_cnt, 1); 1626 mutex_init(&con->con_mutex); 1627 1628 clt_path->s.con[cid] = &con->c; 1629 1630 return 0; 1631 } 1632 1633 static void destroy_con(struct rtrs_clt_con *con) 1634 { 1635 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path); 1636 1637 clt_path->s.con[con->c.cid] = NULL; 1638 mutex_destroy(&con->con_mutex); 1639 kfree(con); 1640 } 1641 1642 static int create_con_cq_qp(struct rtrs_clt_con *con) 1643 { 1644 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path); 1645 u32 max_send_wr, max_recv_wr, cq_num, max_send_sge, wr_limit; 1646 int err, cq_vector; 1647 struct rtrs_msg_rkey_rsp *rsp; 1648 1649 lockdep_assert_held(&con->con_mutex); 1650 if (con->c.cid == 0) { 1651 max_send_sge = 1; 1652 /* We must be the first here */ 1653 if (WARN_ON(clt_path->s.dev)) 1654 return -EINVAL; 1655 1656 /* 1657 * The whole session uses device from user connection. 1658 * Be careful not to close user connection before ib dev 1659 * is gracefully put. 1660 */ 1661 clt_path->s.dev = rtrs_ib_dev_find_or_add(con->c.cm_id->device, 1662 &dev_pd); 1663 if (!clt_path->s.dev) { 1664 rtrs_wrn(clt_path->clt, 1665 "rtrs_ib_dev_find_get_or_add(): no memory\n"); 1666 return -ENOMEM; 1667 } 1668 clt_path->s.dev_ref = 1; 1669 query_fast_reg_mode(clt_path); 1670 wr_limit = clt_path->s.dev->ib_dev->attrs.max_qp_wr; 1671 /* 1672 * Two (request + registration) completion for send 1673 * Two for recv if always_invalidate is set on server 1674 * or one for recv. 1675 * + 2 for drain and heartbeat 1676 * in case qp gets into error state. 1677 */ 1678 max_send_wr = 1679 min_t(int, wr_limit, SERVICE_CON_QUEUE_DEPTH * 2 + 2); 1680 max_recv_wr = max_send_wr; 1681 } else { 1682 /* 1683 * Here we assume that session members are correctly set. 1684 * This is always true if user connection (cid == 0) is 1685 * established first. 1686 */ 1687 if (WARN_ON(!clt_path->s.dev)) 1688 return -EINVAL; 1689 if (WARN_ON(!clt_path->queue_depth)) 1690 return -EINVAL; 1691 1692 wr_limit = clt_path->s.dev->ib_dev->attrs.max_qp_wr; 1693 /* Shared between connections */ 1694 clt_path->s.dev_ref++; 1695 max_send_wr = min_t(int, wr_limit, 1696 /* QD * (REQ + RSP + FR REGS or INVS) + drain */ 1697 clt_path->queue_depth * 3 + 1); 1698 max_recv_wr = min_t(int, wr_limit, 1699 clt_path->queue_depth * 3 + 1); 1700 max_send_sge = 2; 1701 } 1702 atomic_set(&con->c.sq_wr_avail, max_send_wr); 1703 cq_num = max_send_wr + max_recv_wr; 1704 /* alloc iu to recv new rkey reply when server reports flags set */ 1705 if (clt_path->flags & RTRS_MSG_NEW_RKEY_F || con->c.cid == 0) { 1706 con->rsp_ius = rtrs_iu_alloc(cq_num, sizeof(*rsp), 1707 GFP_KERNEL, 1708 clt_path->s.dev->ib_dev, 1709 DMA_FROM_DEVICE, 1710 rtrs_clt_rdma_done); 1711 if (!con->rsp_ius) 1712 return -ENOMEM; 1713 con->queue_num = cq_num; 1714 } 1715 cq_vector = con->cpu % clt_path->s.dev->ib_dev->num_comp_vectors; 1716 if (con->c.cid >= clt_path->s.irq_con_num) 1717 err = rtrs_cq_qp_create(&clt_path->s, &con->c, max_send_sge, 1718 cq_vector, cq_num, max_send_wr, 1719 max_recv_wr, IB_POLL_DIRECT); 1720 else 1721 err = rtrs_cq_qp_create(&clt_path->s, &con->c, max_send_sge, 1722 cq_vector, cq_num, max_send_wr, 1723 max_recv_wr, IB_POLL_SOFTIRQ); 1724 /* 1725 * In case of error we do not bother to clean previous allocations, 1726 * since destroy_con_cq_qp() must be called. 1727 */ 1728 return err; 1729 } 1730 1731 static void destroy_con_cq_qp(struct rtrs_clt_con *con) 1732 { 1733 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path); 1734 1735 /* 1736 * Be careful here: destroy_con_cq_qp() can be called even 1737 * create_con_cq_qp() failed, see comments there. 1738 */ 1739 lockdep_assert_held(&con->con_mutex); 1740 rtrs_cq_qp_destroy(&con->c); 1741 if (con->rsp_ius) { 1742 rtrs_iu_free(con->rsp_ius, clt_path->s.dev->ib_dev, 1743 con->queue_num); 1744 con->rsp_ius = NULL; 1745 con->queue_num = 0; 1746 } 1747 if (clt_path->s.dev_ref && !--clt_path->s.dev_ref) { 1748 rtrs_ib_dev_put(clt_path->s.dev); 1749 clt_path->s.dev = NULL; 1750 } 1751 } 1752 1753 static void stop_cm(struct rtrs_clt_con *con) 1754 { 1755 rdma_disconnect(con->c.cm_id); 1756 if (con->c.qp) 1757 ib_drain_qp(con->c.qp); 1758 } 1759 1760 static void destroy_cm(struct rtrs_clt_con *con) 1761 { 1762 rdma_destroy_id(con->c.cm_id); 1763 con->c.cm_id = NULL; 1764 } 1765 1766 static int rtrs_rdma_addr_resolved(struct rtrs_clt_con *con) 1767 { 1768 struct rtrs_path *s = con->c.path; 1769 int err; 1770 1771 mutex_lock(&con->con_mutex); 1772 err = create_con_cq_qp(con); 1773 mutex_unlock(&con->con_mutex); 1774 if (err) { 1775 rtrs_err(s, "create_con_cq_qp(), err: %d\n", err); 1776 return err; 1777 } 1778 err = rdma_resolve_route(con->c.cm_id, RTRS_CONNECT_TIMEOUT_MS); 1779 if (err) 1780 rtrs_err(s, "Resolving route failed, err: %d\n", err); 1781 1782 return err; 1783 } 1784 1785 static int rtrs_rdma_route_resolved(struct rtrs_clt_con *con) 1786 { 1787 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path); 1788 struct rtrs_clt_sess *clt = clt_path->clt; 1789 struct rtrs_msg_conn_req msg; 1790 struct rdma_conn_param param; 1791 1792 int err; 1793 1794 param = (struct rdma_conn_param) { 1795 .retry_count = 7, 1796 .rnr_retry_count = 7, 1797 .private_data = &msg, 1798 .private_data_len = sizeof(msg), 1799 }; 1800 1801 msg = (struct rtrs_msg_conn_req) { 1802 .magic = cpu_to_le16(RTRS_MAGIC), 1803 .version = cpu_to_le16(RTRS_PROTO_VER), 1804 .cid = cpu_to_le16(con->c.cid), 1805 .cid_num = cpu_to_le16(clt_path->s.con_num), 1806 .recon_cnt = cpu_to_le16(clt_path->s.recon_cnt), 1807 }; 1808 msg.first_conn = clt_path->for_new_clt ? FIRST_CONN : 0; 1809 uuid_copy(&msg.sess_uuid, &clt_path->s.uuid); 1810 uuid_copy(&msg.paths_uuid, &clt->paths_uuid); 1811 1812 err = rdma_connect_locked(con->c.cm_id, ¶m); 1813 if (err) 1814 rtrs_err(clt, "rdma_connect_locked(): %d\n", err); 1815 1816 return err; 1817 } 1818 1819 static int rtrs_rdma_conn_established(struct rtrs_clt_con *con, 1820 struct rdma_cm_event *ev) 1821 { 1822 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path); 1823 struct rtrs_clt_sess *clt = clt_path->clt; 1824 const struct rtrs_msg_conn_rsp *msg; 1825 u16 version, queue_depth; 1826 int errno; 1827 u8 len; 1828 1829 msg = ev->param.conn.private_data; 1830 len = ev->param.conn.private_data_len; 1831 if (len < sizeof(*msg)) { 1832 rtrs_err(clt, "Invalid RTRS connection response\n"); 1833 return -ECONNRESET; 1834 } 1835 if (le16_to_cpu(msg->magic) != RTRS_MAGIC) { 1836 rtrs_err(clt, "Invalid RTRS magic\n"); 1837 return -ECONNRESET; 1838 } 1839 version = le16_to_cpu(msg->version); 1840 if (version >> 8 != RTRS_PROTO_VER_MAJOR) { 1841 rtrs_err(clt, "Unsupported major RTRS version: %d, expected %d\n", 1842 version >> 8, RTRS_PROTO_VER_MAJOR); 1843 return -ECONNRESET; 1844 } 1845 errno = le16_to_cpu(msg->errno); 1846 if (errno) { 1847 rtrs_err(clt, "Invalid RTRS message: errno %d\n", 1848 errno); 1849 return -ECONNRESET; 1850 } 1851 if (con->c.cid == 0) { 1852 queue_depth = le16_to_cpu(msg->queue_depth); 1853 1854 if (clt_path->queue_depth > 0 && queue_depth != clt_path->queue_depth) { 1855 rtrs_err(clt, "Error: queue depth changed\n"); 1856 1857 /* 1858 * Stop any more reconnection attempts 1859 */ 1860 clt_path->reconnect_attempts = -1; 1861 rtrs_err(clt, 1862 "Disabling auto-reconnect. Trigger a manual reconnect after issue is resolved\n"); 1863 return -ECONNRESET; 1864 } 1865 1866 if (!clt_path->rbufs) { 1867 clt_path->rbufs = kcalloc(queue_depth, 1868 sizeof(*clt_path->rbufs), 1869 GFP_KERNEL); 1870 if (!clt_path->rbufs) 1871 return -ENOMEM; 1872 } 1873 clt_path->queue_depth = queue_depth; 1874 clt_path->s.signal_interval = min_not_zero(queue_depth, 1875 (unsigned short) SERVICE_CON_QUEUE_DEPTH); 1876 clt_path->max_hdr_size = le32_to_cpu(msg->max_hdr_size); 1877 clt_path->max_io_size = le32_to_cpu(msg->max_io_size); 1878 clt_path->flags = le32_to_cpu(msg->flags); 1879 clt_path->chunk_size = clt_path->max_io_size + clt_path->max_hdr_size; 1880 1881 /* 1882 * Global IO size is always a minimum. 1883 * If while a reconnection server sends us a value a bit 1884 * higher - client does not care and uses cached minimum. 1885 * 1886 * Since we can have several sessions (paths) restablishing 1887 * connections in parallel, use lock. 1888 */ 1889 mutex_lock(&clt->paths_mutex); 1890 clt->queue_depth = clt_path->queue_depth; 1891 clt->max_io_size = min_not_zero(clt_path->max_io_size, 1892 clt->max_io_size); 1893 mutex_unlock(&clt->paths_mutex); 1894 1895 /* 1896 * Cache the hca_port and hca_name for sysfs 1897 */ 1898 clt_path->hca_port = con->c.cm_id->port_num; 1899 scnprintf(clt_path->hca_name, sizeof(clt_path->hca_name), 1900 clt_path->s.dev->ib_dev->name); 1901 clt_path->s.src_addr = con->c.cm_id->route.addr.src_addr; 1902 /* set for_new_clt, to allow future reconnect on any path */ 1903 clt_path->for_new_clt = 1; 1904 } 1905 1906 return 0; 1907 } 1908 1909 static inline void flag_success_on_conn(struct rtrs_clt_con *con) 1910 { 1911 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path); 1912 1913 atomic_inc(&clt_path->connected_cnt); 1914 con->cm_err = 1; 1915 } 1916 1917 static int rtrs_rdma_conn_rejected(struct rtrs_clt_con *con, 1918 struct rdma_cm_event *ev) 1919 { 1920 struct rtrs_path *s = con->c.path; 1921 const struct rtrs_msg_conn_rsp *msg; 1922 const char *rej_msg; 1923 int status, errno; 1924 u8 data_len; 1925 1926 status = ev->status; 1927 rej_msg = rdma_reject_msg(con->c.cm_id, status); 1928 msg = rdma_consumer_reject_data(con->c.cm_id, ev, &data_len); 1929 1930 if (msg && data_len >= sizeof(*msg)) { 1931 errno = (int16_t)le16_to_cpu(msg->errno); 1932 if (errno == -EBUSY) 1933 rtrs_err(s, 1934 "Previous session is still exists on the server, please reconnect later\n"); 1935 else 1936 rtrs_err(s, 1937 "Connect rejected: status %d (%s), rtrs errno %d\n", 1938 status, rej_msg, errno); 1939 } else { 1940 rtrs_err(s, 1941 "Connect rejected but with malformed message: status %d (%s)\n", 1942 status, rej_msg); 1943 } 1944 1945 return -ECONNRESET; 1946 } 1947 1948 void rtrs_clt_close_conns(struct rtrs_clt_path *clt_path, bool wait) 1949 { 1950 trace_rtrs_clt_close_conns(clt_path); 1951 1952 if (rtrs_clt_change_state_get_old(clt_path, RTRS_CLT_CLOSING, NULL)) 1953 queue_work(rtrs_wq, &clt_path->close_work); 1954 if (wait) 1955 flush_work(&clt_path->close_work); 1956 } 1957 1958 static inline void flag_error_on_conn(struct rtrs_clt_con *con, int cm_err) 1959 { 1960 if (con->cm_err == 1) { 1961 struct rtrs_clt_path *clt_path; 1962 1963 clt_path = to_clt_path(con->c.path); 1964 if (atomic_dec_and_test(&clt_path->connected_cnt)) 1965 1966 wake_up(&clt_path->state_wq); 1967 } 1968 con->cm_err = cm_err; 1969 } 1970 1971 static int rtrs_clt_rdma_cm_handler(struct rdma_cm_id *cm_id, 1972 struct rdma_cm_event *ev) 1973 { 1974 struct rtrs_clt_con *con = cm_id->context; 1975 struct rtrs_path *s = con->c.path; 1976 struct rtrs_clt_path *clt_path = to_clt_path(s); 1977 int cm_err = 0; 1978 1979 switch (ev->event) { 1980 case RDMA_CM_EVENT_ADDR_RESOLVED: 1981 cm_err = rtrs_rdma_addr_resolved(con); 1982 break; 1983 case RDMA_CM_EVENT_ROUTE_RESOLVED: 1984 cm_err = rtrs_rdma_route_resolved(con); 1985 break; 1986 case RDMA_CM_EVENT_ESTABLISHED: 1987 cm_err = rtrs_rdma_conn_established(con, ev); 1988 if (!cm_err) { 1989 /* 1990 * Report success and wake up. Here we abuse state_wq, 1991 * i.e. wake up without state change, but we set cm_err. 1992 */ 1993 flag_success_on_conn(con); 1994 wake_up(&clt_path->state_wq); 1995 return 0; 1996 } 1997 break; 1998 case RDMA_CM_EVENT_REJECTED: 1999 cm_err = rtrs_rdma_conn_rejected(con, ev); 2000 break; 2001 case RDMA_CM_EVENT_DISCONNECTED: 2002 /* No message for disconnecting */ 2003 cm_err = -ECONNRESET; 2004 break; 2005 case RDMA_CM_EVENT_CONNECT_ERROR: 2006 case RDMA_CM_EVENT_UNREACHABLE: 2007 case RDMA_CM_EVENT_ADDR_CHANGE: 2008 case RDMA_CM_EVENT_TIMEWAIT_EXIT: 2009 rtrs_wrn(s, "CM error (CM event: %s, err: %d)\n", 2010 rdma_event_msg(ev->event), ev->status); 2011 cm_err = -ECONNRESET; 2012 break; 2013 case RDMA_CM_EVENT_ADDR_ERROR: 2014 case RDMA_CM_EVENT_ROUTE_ERROR: 2015 rtrs_wrn(s, "CM error (CM event: %s, err: %d)\n", 2016 rdma_event_msg(ev->event), ev->status); 2017 cm_err = -EHOSTUNREACH; 2018 break; 2019 case RDMA_CM_EVENT_DEVICE_REMOVAL: 2020 /* 2021 * Device removal is a special case. Queue close and return 0. 2022 */ 2023 rtrs_clt_close_conns(clt_path, false); 2024 return 0; 2025 default: 2026 rtrs_err(s, "Unexpected RDMA CM error (CM event: %s, err: %d)\n", 2027 rdma_event_msg(ev->event), ev->status); 2028 cm_err = -ECONNRESET; 2029 break; 2030 } 2031 2032 if (cm_err) { 2033 /* 2034 * cm error makes sense only on connection establishing, 2035 * in other cases we rely on normal procedure of reconnecting. 2036 */ 2037 flag_error_on_conn(con, cm_err); 2038 rtrs_rdma_error_recovery(con); 2039 } 2040 2041 return 0; 2042 } 2043 2044 /* The caller should do the cleanup in case of error */ 2045 static int create_cm(struct rtrs_clt_con *con) 2046 { 2047 struct rtrs_path *s = con->c.path; 2048 struct rtrs_clt_path *clt_path = to_clt_path(s); 2049 struct rdma_cm_id *cm_id; 2050 int err; 2051 2052 cm_id = rdma_create_id(&init_net, rtrs_clt_rdma_cm_handler, con, 2053 clt_path->s.dst_addr.ss_family == AF_IB ? 2054 RDMA_PS_IB : RDMA_PS_TCP, IB_QPT_RC); 2055 if (IS_ERR(cm_id)) { 2056 err = PTR_ERR(cm_id); 2057 rtrs_err(s, "Failed to create CM ID, err: %d\n", err); 2058 2059 return err; 2060 } 2061 con->c.cm_id = cm_id; 2062 con->cm_err = 0; 2063 /* allow the port to be reused */ 2064 err = rdma_set_reuseaddr(cm_id, 1); 2065 if (err != 0) { 2066 rtrs_err(s, "Set address reuse failed, err: %d\n", err); 2067 return err; 2068 } 2069 err = rdma_resolve_addr(cm_id, (struct sockaddr *)&clt_path->s.src_addr, 2070 (struct sockaddr *)&clt_path->s.dst_addr, 2071 RTRS_CONNECT_TIMEOUT_MS); 2072 if (err) { 2073 rtrs_err(s, "Failed to resolve address, err: %d\n", err); 2074 return err; 2075 } 2076 /* 2077 * Combine connection status and session events. This is needed 2078 * for waiting two possible cases: cm_err has something meaningful 2079 * or session state was really changed to error by device removal. 2080 */ 2081 err = wait_event_interruptible_timeout( 2082 clt_path->state_wq, 2083 con->cm_err || clt_path->state != RTRS_CLT_CONNECTING, 2084 msecs_to_jiffies(RTRS_CONNECT_TIMEOUT_MS)); 2085 if (err == 0 || err == -ERESTARTSYS) { 2086 if (err == 0) 2087 err = -ETIMEDOUT; 2088 /* Timedout or interrupted */ 2089 return err; 2090 } 2091 if (con->cm_err < 0) 2092 return con->cm_err; 2093 if (READ_ONCE(clt_path->state) != RTRS_CLT_CONNECTING) 2094 /* Device removal */ 2095 return -ECONNABORTED; 2096 2097 return 0; 2098 } 2099 2100 static void rtrs_clt_path_up(struct rtrs_clt_path *clt_path) 2101 { 2102 struct rtrs_clt_sess *clt = clt_path->clt; 2103 int up; 2104 2105 /* 2106 * We can fire RECONNECTED event only when all paths were 2107 * connected on rtrs_clt_open(), then each was disconnected 2108 * and the first one connected again. That's why this nasty 2109 * game with counter value. 2110 */ 2111 2112 mutex_lock(&clt->paths_ev_mutex); 2113 up = ++clt->paths_up; 2114 /* 2115 * Here it is safe to access paths num directly since up counter 2116 * is greater than MAX_PATHS_NUM only while rtrs_clt_open() is 2117 * in progress, thus paths removals are impossible. 2118 */ 2119 if (up > MAX_PATHS_NUM && up == MAX_PATHS_NUM + clt->paths_num) 2120 clt->paths_up = clt->paths_num; 2121 else if (up == 1) 2122 clt->link_ev(clt->priv, RTRS_CLT_LINK_EV_RECONNECTED); 2123 mutex_unlock(&clt->paths_ev_mutex); 2124 2125 /* Mark session as established */ 2126 clt_path->established = true; 2127 clt_path->reconnect_attempts = 0; 2128 clt_path->stats->reconnects.successful_cnt++; 2129 } 2130 2131 static void rtrs_clt_path_down(struct rtrs_clt_path *clt_path) 2132 { 2133 struct rtrs_clt_sess *clt = clt_path->clt; 2134 2135 if (!clt_path->established) 2136 return; 2137 2138 clt_path->established = false; 2139 mutex_lock(&clt->paths_ev_mutex); 2140 WARN_ON(!clt->paths_up); 2141 if (--clt->paths_up == 0) 2142 clt->link_ev(clt->priv, RTRS_CLT_LINK_EV_DISCONNECTED); 2143 mutex_unlock(&clt->paths_ev_mutex); 2144 } 2145 2146 static void rtrs_clt_stop_and_destroy_conns(struct rtrs_clt_path *clt_path) 2147 { 2148 struct rtrs_clt_con *con; 2149 unsigned int cid; 2150 2151 WARN_ON(READ_ONCE(clt_path->state) == RTRS_CLT_CONNECTED); 2152 2153 /* 2154 * Possible race with rtrs_clt_open(), when DEVICE_REMOVAL comes 2155 * exactly in between. Start destroying after it finishes. 2156 */ 2157 mutex_lock(&clt_path->init_mutex); 2158 mutex_unlock(&clt_path->init_mutex); 2159 2160 /* 2161 * All IO paths must observe !CONNECTED state before we 2162 * free everything. 2163 */ 2164 synchronize_rcu(); 2165 2166 rtrs_stop_hb(&clt_path->s); 2167 2168 /* 2169 * The order it utterly crucial: firstly disconnect and complete all 2170 * rdma requests with error (thus set in_use=false for requests), 2171 * then fail outstanding requests checking in_use for each, and 2172 * eventually notify upper layer about session disconnection. 2173 */ 2174 2175 for (cid = 0; cid < clt_path->s.con_num; cid++) { 2176 if (!clt_path->s.con[cid]) 2177 break; 2178 con = to_clt_con(clt_path->s.con[cid]); 2179 stop_cm(con); 2180 } 2181 fail_all_outstanding_reqs(clt_path); 2182 free_path_reqs(clt_path); 2183 rtrs_clt_path_down(clt_path); 2184 2185 /* 2186 * Wait for graceful shutdown, namely when peer side invokes 2187 * rdma_disconnect(). 'connected_cnt' is decremented only on 2188 * CM events, thus if other side had crashed and hb has detected 2189 * something is wrong, here we will stuck for exactly timeout ms, 2190 * since CM does not fire anything. That is fine, we are not in 2191 * hurry. 2192 */ 2193 wait_event_timeout(clt_path->state_wq, 2194 !atomic_read(&clt_path->connected_cnt), 2195 msecs_to_jiffies(RTRS_CONNECT_TIMEOUT_MS)); 2196 2197 for (cid = 0; cid < clt_path->s.con_num; cid++) { 2198 if (!clt_path->s.con[cid]) 2199 break; 2200 con = to_clt_con(clt_path->s.con[cid]); 2201 mutex_lock(&con->con_mutex); 2202 destroy_con_cq_qp(con); 2203 mutex_unlock(&con->con_mutex); 2204 destroy_cm(con); 2205 destroy_con(con); 2206 } 2207 } 2208 2209 static void rtrs_clt_remove_path_from_arr(struct rtrs_clt_path *clt_path) 2210 { 2211 struct rtrs_clt_sess *clt = clt_path->clt; 2212 struct rtrs_clt_path *next; 2213 bool wait_for_grace = false; 2214 int cpu; 2215 2216 mutex_lock(&clt->paths_mutex); 2217 list_del_rcu(&clt_path->s.entry); 2218 2219 /* Make sure everybody observes path removal. */ 2220 synchronize_rcu(); 2221 2222 /* 2223 * At this point nobody sees @sess in the list, but still we have 2224 * dangling pointer @pcpu_path which _can_ point to @sess. Since 2225 * nobody can observe @sess in the list, we guarantee that IO path 2226 * will not assign @sess to @pcpu_path, i.e. @pcpu_path can be equal 2227 * to @sess, but can never again become @sess. 2228 */ 2229 2230 /* 2231 * Decrement paths number only after grace period, because 2232 * caller of do_each_path() must firstly observe list without 2233 * path and only then decremented paths number. 2234 * 2235 * Otherwise there can be the following situation: 2236 * o Two paths exist and IO is coming. 2237 * o One path is removed: 2238 * CPU#0 CPU#1 2239 * do_each_path(): rtrs_clt_remove_path_from_arr(): 2240 * path = get_next_path() 2241 * ^^^ list_del_rcu(path) 2242 * [!CONNECTED path] clt->paths_num-- 2243 * ^^^^^^^^^ 2244 * load clt->paths_num from 2 to 1 2245 * ^^^^^^^^^ 2246 * sees 1 2247 * 2248 * path is observed as !CONNECTED, but do_each_path() loop 2249 * ends, because expression i < clt->paths_num is false. 2250 */ 2251 clt->paths_num--; 2252 2253 /* 2254 * Get @next connection from current @sess which is going to be 2255 * removed. If @sess is the last element, then @next is NULL. 2256 */ 2257 rcu_read_lock(); 2258 next = rtrs_clt_get_next_path_or_null(&clt->paths_list, clt_path); 2259 rcu_read_unlock(); 2260 2261 /* 2262 * @pcpu paths can still point to the path which is going to be 2263 * removed, so change the pointer manually. 2264 */ 2265 for_each_possible_cpu(cpu) { 2266 struct rtrs_clt_path __rcu **ppcpu_path; 2267 2268 ppcpu_path = per_cpu_ptr(clt->pcpu_path, cpu); 2269 if (rcu_dereference_protected(*ppcpu_path, 2270 lockdep_is_held(&clt->paths_mutex)) != clt_path) 2271 /* 2272 * synchronize_rcu() was called just after deleting 2273 * entry from the list, thus IO code path cannot 2274 * change pointer back to the pointer which is going 2275 * to be removed, we are safe here. 2276 */ 2277 continue; 2278 2279 /* 2280 * We race with IO code path, which also changes pointer, 2281 * thus we have to be careful not to overwrite it. 2282 */ 2283 if (try_cmpxchg((struct rtrs_clt_path **)ppcpu_path, &clt_path, 2284 next)) 2285 /* 2286 * @ppcpu_path was successfully replaced with @next, 2287 * that means that someone could also pick up the 2288 * @sess and dereferencing it right now, so wait for 2289 * a grace period is required. 2290 */ 2291 wait_for_grace = true; 2292 } 2293 if (wait_for_grace) 2294 synchronize_rcu(); 2295 2296 mutex_unlock(&clt->paths_mutex); 2297 } 2298 2299 static void rtrs_clt_add_path_to_arr(struct rtrs_clt_path *clt_path) 2300 { 2301 struct rtrs_clt_sess *clt = clt_path->clt; 2302 2303 mutex_lock(&clt->paths_mutex); 2304 clt->paths_num++; 2305 2306 list_add_tail_rcu(&clt_path->s.entry, &clt->paths_list); 2307 mutex_unlock(&clt->paths_mutex); 2308 } 2309 2310 static void rtrs_clt_close_work(struct work_struct *work) 2311 { 2312 struct rtrs_clt_path *clt_path; 2313 2314 clt_path = container_of(work, struct rtrs_clt_path, close_work); 2315 2316 cancel_work_sync(&clt_path->err_recovery_work); 2317 cancel_delayed_work_sync(&clt_path->reconnect_dwork); 2318 rtrs_clt_stop_and_destroy_conns(clt_path); 2319 rtrs_clt_change_state_get_old(clt_path, RTRS_CLT_CLOSED, NULL); 2320 } 2321 2322 static int init_conns(struct rtrs_clt_path *clt_path) 2323 { 2324 unsigned int cid; 2325 int err, i; 2326 2327 /* 2328 * On every new session connections increase reconnect counter 2329 * to avoid clashes with previous sessions not yet closed 2330 * sessions on a server side. 2331 */ 2332 clt_path->s.recon_cnt++; 2333 2334 /* Establish all RDMA connections */ 2335 for (cid = 0; cid < clt_path->s.con_num; cid++) { 2336 err = create_con(clt_path, cid); 2337 if (err) 2338 goto destroy; 2339 2340 err = create_cm(to_clt_con(clt_path->s.con[cid])); 2341 if (err) 2342 goto destroy; 2343 } 2344 err = alloc_path_reqs(clt_path); 2345 if (err) 2346 goto destroy; 2347 2348 rtrs_start_hb(&clt_path->s); 2349 2350 return 0; 2351 2352 destroy: 2353 /* Make sure we do the cleanup in the order they are created */ 2354 for (i = 0; i <= cid; i++) { 2355 struct rtrs_clt_con *con; 2356 2357 if (!clt_path->s.con[i]) 2358 break; 2359 2360 con = to_clt_con(clt_path->s.con[i]); 2361 if (con->c.cm_id) { 2362 stop_cm(con); 2363 mutex_lock(&con->con_mutex); 2364 destroy_con_cq_qp(con); 2365 mutex_unlock(&con->con_mutex); 2366 destroy_cm(con); 2367 } 2368 destroy_con(con); 2369 } 2370 /* 2371 * If we've never taken async path and got an error, say, 2372 * doing rdma_resolve_addr(), switch to CONNECTION_ERR state 2373 * manually to keep reconnecting. 2374 */ 2375 rtrs_clt_change_state_get_old(clt_path, RTRS_CLT_CONNECTING_ERR, NULL); 2376 2377 return err; 2378 } 2379 2380 static void rtrs_clt_info_req_done(struct ib_cq *cq, struct ib_wc *wc) 2381 { 2382 struct rtrs_clt_con *con = to_clt_con(wc->qp->qp_context); 2383 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path); 2384 struct rtrs_iu *iu; 2385 2386 iu = container_of(wc->wr_cqe, struct rtrs_iu, cqe); 2387 rtrs_iu_free(iu, clt_path->s.dev->ib_dev, 1); 2388 2389 if (wc->status != IB_WC_SUCCESS) { 2390 rtrs_err(clt_path->clt, "Path info request send failed: %s\n", 2391 ib_wc_status_msg(wc->status)); 2392 rtrs_clt_change_state_get_old(clt_path, RTRS_CLT_CONNECTING_ERR, NULL); 2393 return; 2394 } 2395 2396 rtrs_clt_update_wc_stats(con); 2397 } 2398 2399 static int process_info_rsp(struct rtrs_clt_path *clt_path, 2400 const struct rtrs_msg_info_rsp *msg) 2401 { 2402 unsigned int sg_cnt, total_len; 2403 int i, sgi; 2404 2405 sg_cnt = le16_to_cpu(msg->sg_cnt); 2406 if (!sg_cnt || (clt_path->queue_depth % sg_cnt)) { 2407 rtrs_err(clt_path->clt, 2408 "Incorrect sg_cnt %d, is not multiple\n", 2409 sg_cnt); 2410 return -EINVAL; 2411 } 2412 2413 /* 2414 * Check if IB immediate data size is enough to hold the mem_id and 2415 * the offset inside the memory chunk. 2416 */ 2417 if ((ilog2(sg_cnt - 1) + 1) + (ilog2(clt_path->chunk_size - 1) + 1) > 2418 MAX_IMM_PAYL_BITS) { 2419 rtrs_err(clt_path->clt, 2420 "RDMA immediate size (%db) not enough to encode %d buffers of size %dB\n", 2421 MAX_IMM_PAYL_BITS, sg_cnt, clt_path->chunk_size); 2422 return -EINVAL; 2423 } 2424 total_len = 0; 2425 for (sgi = 0, i = 0; sgi < sg_cnt && i < clt_path->queue_depth; sgi++) { 2426 const struct rtrs_sg_desc *desc = &msg->desc[sgi]; 2427 u32 len, rkey; 2428 u64 addr; 2429 2430 addr = le64_to_cpu(desc->addr); 2431 rkey = le32_to_cpu(desc->key); 2432 len = le32_to_cpu(desc->len); 2433 2434 total_len += len; 2435 2436 if (!len || (len % clt_path->chunk_size)) { 2437 rtrs_err(clt_path->clt, "Incorrect [%d].len %d\n", 2438 sgi, 2439 len); 2440 return -EINVAL; 2441 } 2442 for ( ; len && i < clt_path->queue_depth; i++) { 2443 clt_path->rbufs[i].addr = addr; 2444 clt_path->rbufs[i].rkey = rkey; 2445 2446 len -= clt_path->chunk_size; 2447 addr += clt_path->chunk_size; 2448 } 2449 } 2450 /* Sanity check */ 2451 if (sgi != sg_cnt || i != clt_path->queue_depth) { 2452 rtrs_err(clt_path->clt, 2453 "Incorrect sg vector, not fully mapped\n"); 2454 return -EINVAL; 2455 } 2456 if (total_len != clt_path->chunk_size * clt_path->queue_depth) { 2457 rtrs_err(clt_path->clt, "Incorrect total_len %d\n", total_len); 2458 return -EINVAL; 2459 } 2460 2461 return 0; 2462 } 2463 2464 static void rtrs_clt_info_rsp_done(struct ib_cq *cq, struct ib_wc *wc) 2465 { 2466 struct rtrs_clt_con *con = to_clt_con(wc->qp->qp_context); 2467 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path); 2468 struct rtrs_msg_info_rsp *msg; 2469 enum rtrs_clt_state state; 2470 struct rtrs_iu *iu; 2471 size_t rx_sz; 2472 int err; 2473 2474 state = RTRS_CLT_CONNECTING_ERR; 2475 2476 WARN_ON(con->c.cid); 2477 iu = container_of(wc->wr_cqe, struct rtrs_iu, cqe); 2478 if (wc->status != IB_WC_SUCCESS) { 2479 rtrs_err(clt_path->clt, "Path info response recv failed: %s\n", 2480 ib_wc_status_msg(wc->status)); 2481 goto out; 2482 } 2483 WARN_ON(wc->opcode != IB_WC_RECV); 2484 2485 if (wc->byte_len < sizeof(*msg)) { 2486 rtrs_err(clt_path->clt, "Path info response is malformed: size %d\n", 2487 wc->byte_len); 2488 goto out; 2489 } 2490 ib_dma_sync_single_for_cpu(clt_path->s.dev->ib_dev, iu->dma_addr, 2491 iu->size, DMA_FROM_DEVICE); 2492 msg = iu->buf; 2493 if (le16_to_cpu(msg->type) != RTRS_MSG_INFO_RSP) { 2494 rtrs_err(clt_path->clt, "Path info response is malformed: type %d\n", 2495 le16_to_cpu(msg->type)); 2496 goto out; 2497 } 2498 rx_sz = sizeof(*msg); 2499 rx_sz += sizeof(msg->desc[0]) * le16_to_cpu(msg->sg_cnt); 2500 if (wc->byte_len < rx_sz) { 2501 rtrs_err(clt_path->clt, "Path info response is malformed: size %d\n", 2502 wc->byte_len); 2503 goto out; 2504 } 2505 err = process_info_rsp(clt_path, msg); 2506 if (err) 2507 goto out; 2508 2509 err = post_recv_path(clt_path); 2510 if (err) 2511 goto out; 2512 2513 state = RTRS_CLT_CONNECTED; 2514 2515 out: 2516 rtrs_clt_update_wc_stats(con); 2517 rtrs_iu_free(iu, clt_path->s.dev->ib_dev, 1); 2518 rtrs_clt_change_state_get_old(clt_path, state, NULL); 2519 } 2520 2521 static int rtrs_send_path_info(struct rtrs_clt_path *clt_path) 2522 { 2523 struct rtrs_clt_con *usr_con = to_clt_con(clt_path->s.con[0]); 2524 struct rtrs_msg_info_req *msg; 2525 struct rtrs_iu *tx_iu, *rx_iu; 2526 size_t rx_sz; 2527 int err; 2528 2529 rx_sz = sizeof(struct rtrs_msg_info_rsp); 2530 rx_sz += sizeof(struct rtrs_sg_desc) * clt_path->queue_depth; 2531 2532 tx_iu = rtrs_iu_alloc(1, sizeof(struct rtrs_msg_info_req), GFP_KERNEL, 2533 clt_path->s.dev->ib_dev, DMA_TO_DEVICE, 2534 rtrs_clt_info_req_done); 2535 rx_iu = rtrs_iu_alloc(1, rx_sz, GFP_KERNEL, clt_path->s.dev->ib_dev, 2536 DMA_FROM_DEVICE, rtrs_clt_info_rsp_done); 2537 if (!tx_iu || !rx_iu) { 2538 err = -ENOMEM; 2539 goto out; 2540 } 2541 /* Prepare for getting info response */ 2542 err = rtrs_iu_post_recv(&usr_con->c, rx_iu); 2543 if (err) { 2544 rtrs_err(clt_path->clt, "rtrs_iu_post_recv(), err: %d\n", err); 2545 goto out; 2546 } 2547 rx_iu = NULL; 2548 2549 msg = tx_iu->buf; 2550 msg->type = cpu_to_le16(RTRS_MSG_INFO_REQ); 2551 memcpy(msg->pathname, clt_path->s.sessname, sizeof(msg->pathname)); 2552 2553 ib_dma_sync_single_for_device(clt_path->s.dev->ib_dev, 2554 tx_iu->dma_addr, 2555 tx_iu->size, DMA_TO_DEVICE); 2556 2557 /* Send info request */ 2558 err = rtrs_iu_post_send(&usr_con->c, tx_iu, sizeof(*msg), NULL); 2559 if (err) { 2560 rtrs_err(clt_path->clt, "rtrs_iu_post_send(), err: %d\n", err); 2561 goto out; 2562 } 2563 tx_iu = NULL; 2564 2565 /* Wait for state change */ 2566 wait_event_interruptible_timeout(clt_path->state_wq, 2567 clt_path->state != RTRS_CLT_CONNECTING, 2568 msecs_to_jiffies( 2569 RTRS_CONNECT_TIMEOUT_MS)); 2570 if (READ_ONCE(clt_path->state) != RTRS_CLT_CONNECTED) { 2571 if (READ_ONCE(clt_path->state) == RTRS_CLT_CONNECTING_ERR) 2572 err = -ECONNRESET; 2573 else 2574 err = -ETIMEDOUT; 2575 } 2576 2577 out: 2578 if (tx_iu) 2579 rtrs_iu_free(tx_iu, clt_path->s.dev->ib_dev, 1); 2580 if (rx_iu) 2581 rtrs_iu_free(rx_iu, clt_path->s.dev->ib_dev, 1); 2582 if (err) 2583 /* If we've never taken async path because of malloc problems */ 2584 rtrs_clt_change_state_get_old(clt_path, 2585 RTRS_CLT_CONNECTING_ERR, NULL); 2586 2587 return err; 2588 } 2589 2590 /** 2591 * init_path() - establishes all path connections and does handshake 2592 * @clt_path: client path. 2593 * In case of error full close or reconnect procedure should be taken, 2594 * because reconnect or close async works can be started. 2595 */ 2596 static int init_path(struct rtrs_clt_path *clt_path) 2597 { 2598 int err; 2599 char str[NAME_MAX]; 2600 struct rtrs_addr path = { 2601 .src = &clt_path->s.src_addr, 2602 .dst = &clt_path->s.dst_addr, 2603 }; 2604 2605 rtrs_addr_to_str(&path, str, sizeof(str)); 2606 2607 mutex_lock(&clt_path->init_mutex); 2608 err = init_conns(clt_path); 2609 if (err) { 2610 rtrs_err(clt_path->clt, 2611 "init_conns() failed: err=%d path=%s [%s:%u]\n", err, 2612 str, clt_path->hca_name, clt_path->hca_port); 2613 goto out; 2614 } 2615 err = rtrs_send_path_info(clt_path); 2616 if (err) { 2617 rtrs_err(clt_path->clt, 2618 "rtrs_send_path_info() failed: err=%d path=%s [%s:%u]\n", 2619 err, str, clt_path->hca_name, clt_path->hca_port); 2620 goto out; 2621 } 2622 rtrs_clt_path_up(clt_path); 2623 out: 2624 mutex_unlock(&clt_path->init_mutex); 2625 2626 return err; 2627 } 2628 2629 static void rtrs_clt_reconnect_work(struct work_struct *work) 2630 { 2631 struct rtrs_clt_path *clt_path; 2632 struct rtrs_clt_sess *clt; 2633 int err; 2634 2635 clt_path = container_of(to_delayed_work(work), struct rtrs_clt_path, 2636 reconnect_dwork); 2637 clt = clt_path->clt; 2638 2639 trace_rtrs_clt_reconnect_work(clt_path); 2640 2641 if (READ_ONCE(clt_path->state) != RTRS_CLT_RECONNECTING) 2642 return; 2643 2644 if (clt_path->reconnect_attempts >= clt->max_reconnect_attempts) { 2645 /* Close a path completely if max attempts is reached */ 2646 rtrs_clt_close_conns(clt_path, false); 2647 return; 2648 } 2649 clt_path->reconnect_attempts++; 2650 2651 msleep(RTRS_RECONNECT_BACKOFF); 2652 if (rtrs_clt_change_state_get_old(clt_path, RTRS_CLT_CONNECTING, NULL)) { 2653 err = init_path(clt_path); 2654 if (err) 2655 goto reconnect_again; 2656 } 2657 2658 return; 2659 2660 reconnect_again: 2661 if (rtrs_clt_change_state_get_old(clt_path, RTRS_CLT_RECONNECTING, NULL)) { 2662 clt_path->stats->reconnects.fail_cnt++; 2663 queue_work(rtrs_wq, &clt_path->err_recovery_work); 2664 } 2665 } 2666 2667 static void rtrs_clt_dev_release(struct device *dev) 2668 { 2669 struct rtrs_clt_sess *clt = container_of(dev, struct rtrs_clt_sess, 2670 dev); 2671 2672 mutex_destroy(&clt->paths_ev_mutex); 2673 mutex_destroy(&clt->paths_mutex); 2674 kfree(clt); 2675 } 2676 2677 static struct rtrs_clt_sess *alloc_clt(const char *sessname, size_t paths_num, 2678 u16 port, size_t pdu_sz, void *priv, 2679 void (*link_ev)(void *priv, 2680 enum rtrs_clt_link_ev ev), 2681 unsigned int reconnect_delay_sec, 2682 unsigned int max_reconnect_attempts) 2683 { 2684 struct rtrs_clt_sess *clt; 2685 int err; 2686 2687 if (!paths_num || paths_num > MAX_PATHS_NUM) 2688 return ERR_PTR(-EINVAL); 2689 2690 if (strlen(sessname) >= sizeof(clt->sessname)) 2691 return ERR_PTR(-EINVAL); 2692 2693 clt = kzalloc(sizeof(*clt), GFP_KERNEL); 2694 if (!clt) 2695 return ERR_PTR(-ENOMEM); 2696 2697 clt->pcpu_path = alloc_percpu(typeof(*clt->pcpu_path)); 2698 if (!clt->pcpu_path) { 2699 kfree(clt); 2700 return ERR_PTR(-ENOMEM); 2701 } 2702 2703 clt->dev.class = &rtrs_clt_dev_class; 2704 clt->dev.release = rtrs_clt_dev_release; 2705 uuid_gen(&clt->paths_uuid); 2706 INIT_LIST_HEAD_RCU(&clt->paths_list); 2707 clt->paths_num = paths_num; 2708 clt->paths_up = MAX_PATHS_NUM; 2709 clt->port = port; 2710 clt->pdu_sz = pdu_sz; 2711 clt->max_segments = RTRS_MAX_SEGMENTS; 2712 clt->reconnect_delay_sec = reconnect_delay_sec; 2713 clt->max_reconnect_attempts = max_reconnect_attempts; 2714 clt->priv = priv; 2715 clt->link_ev = link_ev; 2716 clt->mp_policy = MP_POLICY_MIN_INFLIGHT; 2717 strscpy(clt->sessname, sessname, sizeof(clt->sessname)); 2718 init_waitqueue_head(&clt->permits_wait); 2719 mutex_init(&clt->paths_ev_mutex); 2720 mutex_init(&clt->paths_mutex); 2721 device_initialize(&clt->dev); 2722 2723 err = dev_set_name(&clt->dev, "%s", sessname); 2724 if (err) 2725 goto err_put; 2726 2727 /* 2728 * Suppress user space notification until 2729 * sysfs files are created 2730 */ 2731 dev_set_uevent_suppress(&clt->dev, true); 2732 err = device_add(&clt->dev); 2733 if (err) 2734 goto err_put; 2735 2736 clt->kobj_paths = kobject_create_and_add("paths", &clt->dev.kobj); 2737 if (!clt->kobj_paths) { 2738 err = -ENOMEM; 2739 goto err_del; 2740 } 2741 err = rtrs_clt_create_sysfs_root_files(clt); 2742 if (err) { 2743 kobject_del(clt->kobj_paths); 2744 kobject_put(clt->kobj_paths); 2745 goto err_del; 2746 } 2747 dev_set_uevent_suppress(&clt->dev, false); 2748 kobject_uevent(&clt->dev.kobj, KOBJ_ADD); 2749 2750 return clt; 2751 err_del: 2752 device_del(&clt->dev); 2753 err_put: 2754 free_percpu(clt->pcpu_path); 2755 put_device(&clt->dev); 2756 return ERR_PTR(err); 2757 } 2758 2759 static void free_clt(struct rtrs_clt_sess *clt) 2760 { 2761 free_percpu(clt->pcpu_path); 2762 2763 /* 2764 * release callback will free clt and destroy mutexes in last put 2765 */ 2766 device_unregister(&clt->dev); 2767 } 2768 2769 /** 2770 * rtrs_clt_open() - Open a path to an RTRS server 2771 * @ops: holds the link event callback and the private pointer. 2772 * @pathname: name of the path to an RTRS server 2773 * @paths: Paths to be established defined by their src and dst addresses 2774 * @paths_num: Number of elements in the @paths array 2775 * @port: port to be used by the RTRS session 2776 * @pdu_sz: Size of extra payload which can be accessed after permit allocation. 2777 * @reconnect_delay_sec: time between reconnect tries 2778 * @max_reconnect_attempts: Number of times to reconnect on error before giving 2779 * up, 0 for * disabled, -1 for forever 2780 * @nr_poll_queues: number of polling mode connection using IB_POLL_DIRECT flag 2781 * 2782 * Starts session establishment with the rtrs_server. The function can block 2783 * up to ~2000ms before it returns. 2784 * 2785 * Return a valid pointer on success otherwise PTR_ERR. 2786 */ 2787 struct rtrs_clt_sess *rtrs_clt_open(struct rtrs_clt_ops *ops, 2788 const char *pathname, 2789 const struct rtrs_addr *paths, 2790 size_t paths_num, u16 port, 2791 size_t pdu_sz, u8 reconnect_delay_sec, 2792 s16 max_reconnect_attempts, u32 nr_poll_queues) 2793 { 2794 struct rtrs_clt_path *clt_path, *tmp; 2795 struct rtrs_clt_sess *clt; 2796 int err, i; 2797 2798 if (strchr(pathname, '/') || strchr(pathname, '.')) { 2799 pr_err("pathname cannot contain / and .\n"); 2800 err = -EINVAL; 2801 goto out; 2802 } 2803 2804 clt = alloc_clt(pathname, paths_num, port, pdu_sz, ops->priv, 2805 ops->link_ev, 2806 reconnect_delay_sec, 2807 max_reconnect_attempts); 2808 if (IS_ERR(clt)) { 2809 err = PTR_ERR(clt); 2810 goto out; 2811 } 2812 for (i = 0; i < paths_num; i++) { 2813 struct rtrs_clt_path *clt_path; 2814 2815 clt_path = alloc_path(clt, &paths[i], nr_cpu_ids, 2816 nr_poll_queues); 2817 if (IS_ERR(clt_path)) { 2818 err = PTR_ERR(clt_path); 2819 goto close_all_path; 2820 } 2821 if (!i) 2822 clt_path->for_new_clt = 1; 2823 list_add_tail_rcu(&clt_path->s.entry, &clt->paths_list); 2824 2825 err = init_path(clt_path); 2826 if (err) { 2827 list_del_rcu(&clt_path->s.entry); 2828 rtrs_clt_close_conns(clt_path, true); 2829 free_percpu(clt_path->stats->pcpu_stats); 2830 kfree(clt_path->stats); 2831 free_path(clt_path); 2832 goto close_all_path; 2833 } 2834 2835 err = rtrs_clt_create_path_files(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 = alloc_permits(clt); 2846 if (err) 2847 goto close_all_path; 2848 2849 return clt; 2850 2851 close_all_path: 2852 list_for_each_entry_safe(clt_path, tmp, &clt->paths_list, s.entry) { 2853 rtrs_clt_destroy_path_files(clt_path, NULL); 2854 rtrs_clt_close_conns(clt_path, true); 2855 kobject_put(&clt_path->kobj); 2856 } 2857 rtrs_clt_destroy_sysfs_root(clt); 2858 free_clt(clt); 2859 2860 out: 2861 return ERR_PTR(err); 2862 } 2863 EXPORT_SYMBOL(rtrs_clt_open); 2864 2865 /** 2866 * rtrs_clt_close() - Close a path 2867 * @clt: Session handle. Session is freed upon return. 2868 */ 2869 void rtrs_clt_close(struct rtrs_clt_sess *clt) 2870 { 2871 struct rtrs_clt_path *clt_path, *tmp; 2872 2873 /* Firstly forbid sysfs access */ 2874 rtrs_clt_destroy_sysfs_root(clt); 2875 2876 /* Now it is safe to iterate over all paths without locks */ 2877 list_for_each_entry_safe(clt_path, tmp, &clt->paths_list, s.entry) { 2878 rtrs_clt_close_conns(clt_path, true); 2879 rtrs_clt_destroy_path_files(clt_path, NULL); 2880 kobject_put(&clt_path->kobj); 2881 } 2882 free_permits(clt); 2883 free_clt(clt); 2884 } 2885 EXPORT_SYMBOL(rtrs_clt_close); 2886 2887 int rtrs_clt_reconnect_from_sysfs(struct rtrs_clt_path *clt_path) 2888 { 2889 enum rtrs_clt_state old_state; 2890 int err = -EBUSY; 2891 bool changed; 2892 2893 changed = rtrs_clt_change_state_get_old(clt_path, 2894 RTRS_CLT_RECONNECTING, 2895 &old_state); 2896 if (changed) { 2897 clt_path->reconnect_attempts = 0; 2898 rtrs_clt_stop_and_destroy_conns(clt_path); 2899 queue_delayed_work(rtrs_wq, &clt_path->reconnect_dwork, 0); 2900 } 2901 if (changed || old_state == RTRS_CLT_RECONNECTING) { 2902 /* 2903 * flush_delayed_work() queues pending work for immediate 2904 * execution, so do the flush if we have queued something 2905 * right now or work is pending. 2906 */ 2907 flush_delayed_work(&clt_path->reconnect_dwork); 2908 err = (READ_ONCE(clt_path->state) == 2909 RTRS_CLT_CONNECTED ? 0 : -ENOTCONN); 2910 } 2911 2912 return err; 2913 } 2914 2915 int rtrs_clt_remove_path_from_sysfs(struct rtrs_clt_path *clt_path, 2916 const struct attribute *sysfs_self) 2917 { 2918 enum rtrs_clt_state old_state; 2919 bool changed; 2920 2921 /* 2922 * Continue stopping path till state was changed to DEAD or 2923 * state was observed as DEAD: 2924 * 1. State was changed to DEAD - we were fast and nobody 2925 * invoked rtrs_clt_reconnect(), which can again start 2926 * reconnecting. 2927 * 2. State was observed as DEAD - we have someone in parallel 2928 * removing the path. 2929 */ 2930 do { 2931 rtrs_clt_close_conns(clt_path, true); 2932 changed = rtrs_clt_change_state_get_old(clt_path, 2933 RTRS_CLT_DEAD, 2934 &old_state); 2935 } while (!changed && old_state != RTRS_CLT_DEAD); 2936 2937 if (changed) { 2938 rtrs_clt_remove_path_from_arr(clt_path); 2939 rtrs_clt_destroy_path_files(clt_path, sysfs_self); 2940 kobject_put(&clt_path->kobj); 2941 } 2942 2943 return 0; 2944 } 2945 2946 void rtrs_clt_set_max_reconnect_attempts(struct rtrs_clt_sess *clt, int value) 2947 { 2948 clt->max_reconnect_attempts = (unsigned int)value; 2949 } 2950 2951 int rtrs_clt_get_max_reconnect_attempts(const struct rtrs_clt_sess *clt) 2952 { 2953 return (int)clt->max_reconnect_attempts; 2954 } 2955 2956 /** 2957 * rtrs_clt_request() - Request data transfer to/from server via RDMA. 2958 * 2959 * @dir: READ/WRITE 2960 * @ops: callback function to be called as confirmation, and the pointer. 2961 * @clt: Session 2962 * @permit: Preallocated permit 2963 * @vec: Message that is sent to server together with the request. 2964 * Sum of len of all @vec elements limited to <= IO_MSG_SIZE. 2965 * Since the msg is copied internally it can be allocated on stack. 2966 * @nr: Number of elements in @vec. 2967 * @data_len: length of data sent to/from server 2968 * @sg: Pages to be sent/received to/from server. 2969 * @sg_cnt: Number of elements in the @sg 2970 * 2971 * Return: 2972 * 0: Success 2973 * <0: Error 2974 * 2975 * On dir=READ rtrs client will request a data transfer from Server to client. 2976 * The data that the server will respond with will be stored in @sg when 2977 * the user receives an %RTRS_CLT_RDMA_EV_RDMA_REQUEST_WRITE_COMPL event. 2978 * On dir=WRITE rtrs client will rdma write data in sg to server side. 2979 */ 2980 int rtrs_clt_request(int dir, struct rtrs_clt_req_ops *ops, 2981 struct rtrs_clt_sess *clt, struct rtrs_permit *permit, 2982 const struct kvec *vec, size_t nr, size_t data_len, 2983 struct scatterlist *sg, unsigned int sg_cnt) 2984 { 2985 struct rtrs_clt_io_req *req; 2986 struct rtrs_clt_path *clt_path; 2987 2988 enum dma_data_direction dma_dir; 2989 int err = -ECONNABORTED, i; 2990 size_t usr_len, hdr_len; 2991 struct path_it it; 2992 2993 /* Get kvec length */ 2994 for (i = 0, usr_len = 0; i < nr; i++) 2995 usr_len += vec[i].iov_len; 2996 2997 if (dir == READ) { 2998 hdr_len = sizeof(struct rtrs_msg_rdma_read) + 2999 sg_cnt * sizeof(struct rtrs_sg_desc); 3000 dma_dir = DMA_FROM_DEVICE; 3001 } else { 3002 hdr_len = sizeof(struct rtrs_msg_rdma_write); 3003 dma_dir = DMA_TO_DEVICE; 3004 } 3005 3006 rcu_read_lock(); 3007 for (path_it_init(&it, clt); 3008 (clt_path = it.next_path(&it)) && it.i < it.clt->paths_num; it.i++) { 3009 if (READ_ONCE(clt_path->state) != RTRS_CLT_CONNECTED) 3010 continue; 3011 3012 if (usr_len + hdr_len > clt_path->max_hdr_size) { 3013 rtrs_wrn_rl(clt_path->clt, 3014 "%s request failed, user message size is %zu and header length %zu, but max size is %u\n", 3015 dir == READ ? "Read" : "Write", 3016 usr_len, hdr_len, clt_path->max_hdr_size); 3017 err = -EMSGSIZE; 3018 break; 3019 } 3020 req = rtrs_clt_get_req(clt_path, ops->conf_fn, permit, ops->priv, 3021 vec, usr_len, sg, sg_cnt, data_len, 3022 dma_dir); 3023 if (dir == READ) 3024 err = rtrs_clt_read_req(req); 3025 else 3026 err = rtrs_clt_write_req(req); 3027 if (err) { 3028 req->in_use = false; 3029 continue; 3030 } 3031 /* Success path */ 3032 break; 3033 } 3034 path_it_deinit(&it); 3035 rcu_read_unlock(); 3036 3037 return err; 3038 } 3039 EXPORT_SYMBOL(rtrs_clt_request); 3040 3041 int rtrs_clt_rdma_cq_direct(struct rtrs_clt_sess *clt, unsigned int index) 3042 { 3043 /* If no path, return -1 for block layer not to try again */ 3044 int cnt = -1; 3045 struct rtrs_con *con; 3046 struct rtrs_clt_path *clt_path; 3047 struct path_it it; 3048 3049 rcu_read_lock(); 3050 for (path_it_init(&it, clt); 3051 (clt_path = it.next_path(&it)) && it.i < it.clt->paths_num; it.i++) { 3052 if (READ_ONCE(clt_path->state) != RTRS_CLT_CONNECTED) 3053 continue; 3054 3055 con = clt_path->s.con[index + 1]; 3056 cnt = ib_process_cq_direct(con->cq, -1); 3057 if (cnt) 3058 break; 3059 } 3060 path_it_deinit(&it); 3061 rcu_read_unlock(); 3062 3063 return cnt; 3064 } 3065 EXPORT_SYMBOL(rtrs_clt_rdma_cq_direct); 3066 3067 /** 3068 * rtrs_clt_query() - queries RTRS session attributes 3069 *@clt: session pointer 3070 *@attr: query results for session attributes. 3071 * Returns: 3072 * 0 on success 3073 * -ECOMM no connection to the server 3074 */ 3075 int rtrs_clt_query(struct rtrs_clt_sess *clt, struct rtrs_attrs *attr) 3076 { 3077 if (!rtrs_clt_is_connected(clt)) 3078 return -ECOMM; 3079 3080 attr->queue_depth = clt->queue_depth; 3081 attr->max_segments = clt->max_segments; 3082 /* Cap max_io_size to min of remote buffer size and the fr pages */ 3083 attr->max_io_size = min_t(int, clt->max_io_size, 3084 clt->max_segments * SZ_4K); 3085 3086 return 0; 3087 } 3088 EXPORT_SYMBOL(rtrs_clt_query); 3089 3090 int rtrs_clt_create_path_from_sysfs(struct rtrs_clt_sess *clt, 3091 struct rtrs_addr *addr) 3092 { 3093 struct rtrs_clt_path *clt_path; 3094 int err; 3095 3096 clt_path = alloc_path(clt, addr, nr_cpu_ids, 0); 3097 if (IS_ERR(clt_path)) 3098 return PTR_ERR(clt_path); 3099 3100 mutex_lock(&clt->paths_mutex); 3101 if (clt->paths_num == 0) { 3102 /* 3103 * When all the paths are removed for a session, 3104 * the addition of the first path is like a new session for 3105 * the storage server 3106 */ 3107 clt_path->for_new_clt = 1; 3108 } 3109 3110 mutex_unlock(&clt->paths_mutex); 3111 3112 /* 3113 * It is totally safe to add path in CONNECTING state: coming 3114 * IO will never grab it. Also it is very important to add 3115 * path before init, since init fires LINK_CONNECTED event. 3116 */ 3117 rtrs_clt_add_path_to_arr(clt_path); 3118 3119 err = init_path(clt_path); 3120 if (err) 3121 goto close_path; 3122 3123 err = rtrs_clt_create_path_files(clt_path); 3124 if (err) 3125 goto close_path; 3126 3127 return 0; 3128 3129 close_path: 3130 rtrs_clt_remove_path_from_arr(clt_path); 3131 rtrs_clt_close_conns(clt_path, true); 3132 free_percpu(clt_path->stats->pcpu_stats); 3133 kfree(clt_path->stats); 3134 free_path(clt_path); 3135 3136 return err; 3137 } 3138 3139 static int rtrs_clt_ib_dev_init(struct rtrs_ib_dev *dev) 3140 { 3141 if (!(dev->ib_dev->attrs.device_cap_flags & 3142 IB_DEVICE_MEM_MGT_EXTENSIONS)) { 3143 pr_err("Memory registrations not supported.\n"); 3144 return -ENOTSUPP; 3145 } 3146 3147 return 0; 3148 } 3149 3150 static const struct rtrs_rdma_dev_pd_ops dev_pd_ops = { 3151 .init = rtrs_clt_ib_dev_init 3152 }; 3153 3154 static int __init rtrs_client_init(void) 3155 { 3156 int ret = 0; 3157 3158 rtrs_rdma_dev_pd_init(0, &dev_pd); 3159 ret = class_register(&rtrs_clt_dev_class); 3160 if (ret) { 3161 pr_err("Failed to create rtrs-client dev class\n"); 3162 return ret; 3163 } 3164 rtrs_wq = alloc_workqueue("rtrs_client_wq", 0, 0); 3165 if (!rtrs_wq) { 3166 class_unregister(&rtrs_clt_dev_class); 3167 return -ENOMEM; 3168 } 3169 3170 return 0; 3171 } 3172 3173 static void __exit rtrs_client_exit(void) 3174 { 3175 destroy_workqueue(rtrs_wq); 3176 class_unregister(&rtrs_clt_dev_class); 3177 rtrs_rdma_dev_pd_deinit(&dev_pd); 3178 } 3179 3180 module_init(rtrs_client_init); 3181 module_exit(rtrs_client_exit); 3182