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 struct class *rtrs_clt_dev_class; 49 50 static inline bool rtrs_clt_is_connected(const struct rtrs_clt_sess *clt) 51 { 52 struct rtrs_clt_path *clt_path; 53 bool connected = false; 54 55 rcu_read_lock(); 56 list_for_each_entry_rcu(clt_path, &clt->paths_list, s.entry) 57 if (READ_ONCE(clt_path->state) == RTRS_CLT_CONNECTED) { 58 connected = true; 59 break; 60 } 61 rcu_read_unlock(); 62 63 return connected; 64 } 65 66 static struct rtrs_permit * 67 __rtrs_get_permit(struct rtrs_clt_sess *clt, enum rtrs_clt_con_type con_type) 68 { 69 size_t max_depth = clt->queue_depth; 70 struct rtrs_permit *permit; 71 int bit; 72 73 /* 74 * Adapted from null_blk get_tag(). Callers from different cpus may 75 * grab the same bit, since find_first_zero_bit is not atomic. 76 * But then the test_and_set_bit_lock will fail for all the 77 * callers but one, so that they will loop again. 78 * This way an explicit spinlock is not required. 79 */ 80 do { 81 bit = find_first_zero_bit(clt->permits_map, max_depth); 82 if (bit >= max_depth) 83 return NULL; 84 } while (test_and_set_bit_lock(bit, clt->permits_map)); 85 86 permit = get_permit(clt, bit); 87 WARN_ON(permit->mem_id != bit); 88 permit->cpu_id = raw_smp_processor_id(); 89 permit->con_type = con_type; 90 91 return permit; 92 } 93 94 static inline void __rtrs_put_permit(struct rtrs_clt_sess *clt, 95 struct rtrs_permit *permit) 96 { 97 clear_bit_unlock(permit->mem_id, clt->permits_map); 98 } 99 100 /** 101 * rtrs_clt_get_permit() - allocates permit for future RDMA operation 102 * @clt: Current session 103 * @con_type: Type of connection to use with the permit 104 * @can_wait: Wait type 105 * 106 * Description: 107 * Allocates permit for the following RDMA operation. Permit is used 108 * to preallocate all resources and to propagate memory pressure 109 * up earlier. 110 * 111 * Context: 112 * Can sleep if @wait == RTRS_PERMIT_WAIT 113 */ 114 struct rtrs_permit *rtrs_clt_get_permit(struct rtrs_clt_sess *clt, 115 enum rtrs_clt_con_type con_type, 116 enum wait_type can_wait) 117 { 118 struct rtrs_permit *permit; 119 DEFINE_WAIT(wait); 120 121 permit = __rtrs_get_permit(clt, con_type); 122 if (permit || !can_wait) 123 return permit; 124 125 do { 126 prepare_to_wait(&clt->permits_wait, &wait, 127 TASK_UNINTERRUPTIBLE); 128 permit = __rtrs_get_permit(clt, con_type); 129 if (permit) 130 break; 131 132 io_schedule(); 133 } while (1); 134 135 finish_wait(&clt->permits_wait, &wait); 136 137 return permit; 138 } 139 EXPORT_SYMBOL(rtrs_clt_get_permit); 140 141 /** 142 * rtrs_clt_put_permit() - puts allocated permit 143 * @clt: Current session 144 * @permit: Permit to be freed 145 * 146 * Context: 147 * Does not matter 148 */ 149 void rtrs_clt_put_permit(struct rtrs_clt_sess *clt, 150 struct rtrs_permit *permit) 151 { 152 if (WARN_ON(!test_bit(permit->mem_id, clt->permits_map))) 153 return; 154 155 __rtrs_put_permit(clt, permit); 156 157 /* 158 * rtrs_clt_get_permit() adds itself to the &clt->permits_wait list 159 * before calling schedule(). So if rtrs_clt_get_permit() is sleeping 160 * it must have added itself to &clt->permits_wait before 161 * __rtrs_put_permit() finished. 162 * Hence it is safe to guard wake_up() with a waitqueue_active() test. 163 */ 164 if (waitqueue_active(&clt->permits_wait)) 165 wake_up(&clt->permits_wait); 166 } 167 EXPORT_SYMBOL(rtrs_clt_put_permit); 168 169 /** 170 * rtrs_permit_to_clt_con() - returns RDMA connection pointer by the permit 171 * @clt_path: client path pointer 172 * @permit: permit for the allocation of the RDMA buffer 173 * Note: 174 * IO connection starts from 1. 175 * 0 connection is for user messages. 176 */ 177 static 178 struct rtrs_clt_con *rtrs_permit_to_clt_con(struct rtrs_clt_path *clt_path, 179 struct rtrs_permit *permit) 180 { 181 int id = 0; 182 183 if (permit->con_type == RTRS_IO_CON) 184 id = (permit->cpu_id % (clt_path->s.irq_con_num - 1)) + 1; 185 186 return to_clt_con(clt_path->s.con[id]); 187 } 188 189 /** 190 * rtrs_clt_change_state() - change the session state through session state 191 * machine. 192 * 193 * @clt_path: client path to change the state of. 194 * @new_state: state to change to. 195 * 196 * returns true if sess's state is changed to new state, otherwise return false. 197 * 198 * Locks: 199 * state_wq lock must be hold. 200 */ 201 static bool rtrs_clt_change_state(struct rtrs_clt_path *clt_path, 202 enum rtrs_clt_state new_state) 203 { 204 enum rtrs_clt_state old_state; 205 bool changed = false; 206 207 lockdep_assert_held(&clt_path->state_wq.lock); 208 209 old_state = clt_path->state; 210 switch (new_state) { 211 case RTRS_CLT_CONNECTING: 212 switch (old_state) { 213 case RTRS_CLT_RECONNECTING: 214 changed = true; 215 fallthrough; 216 default: 217 break; 218 } 219 break; 220 case RTRS_CLT_RECONNECTING: 221 switch (old_state) { 222 case RTRS_CLT_CONNECTED: 223 case RTRS_CLT_CONNECTING_ERR: 224 case RTRS_CLT_CLOSED: 225 changed = true; 226 fallthrough; 227 default: 228 break; 229 } 230 break; 231 case RTRS_CLT_CONNECTED: 232 switch (old_state) { 233 case RTRS_CLT_CONNECTING: 234 changed = true; 235 fallthrough; 236 default: 237 break; 238 } 239 break; 240 case RTRS_CLT_CONNECTING_ERR: 241 switch (old_state) { 242 case RTRS_CLT_CONNECTING: 243 changed = true; 244 fallthrough; 245 default: 246 break; 247 } 248 break; 249 case RTRS_CLT_CLOSING: 250 switch (old_state) { 251 case RTRS_CLT_CONNECTING: 252 case RTRS_CLT_CONNECTING_ERR: 253 case RTRS_CLT_RECONNECTING: 254 case RTRS_CLT_CONNECTED: 255 changed = true; 256 fallthrough; 257 default: 258 break; 259 } 260 break; 261 case RTRS_CLT_CLOSED: 262 switch (old_state) { 263 case RTRS_CLT_CLOSING: 264 changed = true; 265 fallthrough; 266 default: 267 break; 268 } 269 break; 270 case RTRS_CLT_DEAD: 271 switch (old_state) { 272 case RTRS_CLT_CLOSED: 273 changed = true; 274 fallthrough; 275 default: 276 break; 277 } 278 break; 279 default: 280 break; 281 } 282 if (changed) { 283 clt_path->state = new_state; 284 wake_up_locked(&clt_path->state_wq); 285 } 286 287 return changed; 288 } 289 290 static bool rtrs_clt_change_state_from_to(struct rtrs_clt_path *clt_path, 291 enum rtrs_clt_state old_state, 292 enum rtrs_clt_state new_state) 293 { 294 bool changed = false; 295 296 spin_lock_irq(&clt_path->state_wq.lock); 297 if (clt_path->state == old_state) 298 changed = rtrs_clt_change_state(clt_path, new_state); 299 spin_unlock_irq(&clt_path->state_wq.lock); 300 301 return changed; 302 } 303 304 static void rtrs_clt_stop_and_destroy_conns(struct rtrs_clt_path *clt_path); 305 static void rtrs_rdma_error_recovery(struct rtrs_clt_con *con) 306 { 307 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path); 308 309 trace_rtrs_rdma_error_recovery(clt_path); 310 311 if (rtrs_clt_change_state_from_to(clt_path, 312 RTRS_CLT_CONNECTED, 313 RTRS_CLT_RECONNECTING)) { 314 queue_work(rtrs_wq, &clt_path->err_recovery_work); 315 } else { 316 /* 317 * Error can happen just on establishing new connection, 318 * so notify waiter with error state, waiter is responsible 319 * for cleaning the rest and reconnect if needed. 320 */ 321 rtrs_clt_change_state_from_to(clt_path, 322 RTRS_CLT_CONNECTING, 323 RTRS_CLT_CONNECTING_ERR); 324 } 325 } 326 327 static void rtrs_clt_fast_reg_done(struct ib_cq *cq, struct ib_wc *wc) 328 { 329 struct rtrs_clt_con *con = to_clt_con(wc->qp->qp_context); 330 331 if (wc->status != IB_WC_SUCCESS) { 332 rtrs_err(con->c.path, "Failed IB_WR_REG_MR: %s\n", 333 ib_wc_status_msg(wc->status)); 334 rtrs_rdma_error_recovery(con); 335 } 336 } 337 338 static struct ib_cqe fast_reg_cqe = { 339 .done = rtrs_clt_fast_reg_done 340 }; 341 342 static void complete_rdma_req(struct rtrs_clt_io_req *req, int errno, 343 bool notify, bool can_wait); 344 345 static void rtrs_clt_inv_rkey_done(struct ib_cq *cq, struct ib_wc *wc) 346 { 347 struct rtrs_clt_io_req *req = 348 container_of(wc->wr_cqe, typeof(*req), inv_cqe); 349 struct rtrs_clt_con *con = to_clt_con(wc->qp->qp_context); 350 351 if (wc->status != IB_WC_SUCCESS) { 352 rtrs_err(con->c.path, "Failed IB_WR_LOCAL_INV: %s\n", 353 ib_wc_status_msg(wc->status)); 354 rtrs_rdma_error_recovery(con); 355 } 356 req->need_inv = false; 357 if (req->need_inv_comp) 358 complete(&req->inv_comp); 359 else 360 /* Complete request from INV callback */ 361 complete_rdma_req(req, req->inv_errno, true, false); 362 } 363 364 static int rtrs_inv_rkey(struct rtrs_clt_io_req *req) 365 { 366 struct rtrs_clt_con *con = req->con; 367 struct ib_send_wr wr = { 368 .opcode = IB_WR_LOCAL_INV, 369 .wr_cqe = &req->inv_cqe, 370 .send_flags = IB_SEND_SIGNALED, 371 .ex.invalidate_rkey = req->mr->rkey, 372 }; 373 req->inv_cqe.done = rtrs_clt_inv_rkey_done; 374 375 return ib_post_send(con->c.qp, &wr, NULL); 376 } 377 378 static void complete_rdma_req(struct rtrs_clt_io_req *req, int errno, 379 bool notify, bool can_wait) 380 { 381 struct rtrs_clt_con *con = req->con; 382 struct rtrs_clt_path *clt_path; 383 int err; 384 385 if (WARN_ON(!req->in_use)) 386 return; 387 if (WARN_ON(!req->con)) 388 return; 389 clt_path = to_clt_path(con->c.path); 390 391 if (req->sg_cnt) { 392 if (req->dir == DMA_FROM_DEVICE && req->need_inv) { 393 /* 394 * We are here to invalidate read requests 395 * ourselves. In normal scenario server should 396 * send INV for all read requests, but 397 * we are here, thus two things could happen: 398 * 399 * 1. this is failover, when errno != 0 400 * and can_wait == 1, 401 * 402 * 2. something totally bad happened and 403 * server forgot to send INV, so we 404 * should do that ourselves. 405 */ 406 407 if (can_wait) { 408 req->need_inv_comp = true; 409 } else { 410 /* This should be IO path, so always notify */ 411 WARN_ON(!notify); 412 /* Save errno for INV callback */ 413 req->inv_errno = errno; 414 } 415 416 refcount_inc(&req->ref); 417 err = rtrs_inv_rkey(req); 418 if (err) { 419 rtrs_err(con->c.path, "Send INV WR key=%#x: %d\n", 420 req->mr->rkey, err); 421 } else if (can_wait) { 422 wait_for_completion(&req->inv_comp); 423 } else { 424 /* 425 * Something went wrong, so request will be 426 * completed from INV callback. 427 */ 428 WARN_ON_ONCE(1); 429 430 return; 431 } 432 if (!refcount_dec_and_test(&req->ref)) 433 return; 434 } 435 ib_dma_unmap_sg(clt_path->s.dev->ib_dev, req->sglist, 436 req->sg_cnt, req->dir); 437 } 438 if (!refcount_dec_and_test(&req->ref)) 439 return; 440 if (req->mp_policy == MP_POLICY_MIN_INFLIGHT) 441 atomic_dec(&clt_path->stats->inflight); 442 443 req->in_use = false; 444 req->con = NULL; 445 446 if (errno) { 447 rtrs_err_rl(con->c.path, "IO request failed: error=%d path=%s [%s:%u] notify=%d\n", 448 errno, kobject_name(&clt_path->kobj), clt_path->hca_name, 449 clt_path->hca_port, notify); 450 } 451 452 if (notify) 453 req->conf(req->priv, errno); 454 } 455 456 static int rtrs_post_send_rdma(struct rtrs_clt_con *con, 457 struct rtrs_clt_io_req *req, 458 struct rtrs_rbuf *rbuf, u32 off, 459 u32 imm, struct ib_send_wr *wr) 460 { 461 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path); 462 enum ib_send_flags flags; 463 struct ib_sge sge; 464 465 if (!req->sg_size) { 466 rtrs_wrn(con->c.path, 467 "Doing RDMA Write failed, no data supplied\n"); 468 return -EINVAL; 469 } 470 471 /* user data and user message in the first list element */ 472 sge.addr = req->iu->dma_addr; 473 sge.length = req->sg_size; 474 sge.lkey = clt_path->s.dev->ib_pd->local_dma_lkey; 475 476 /* 477 * From time to time we have to post signalled sends, 478 * or send queue will fill up and only QP reset can help. 479 */ 480 flags = atomic_inc_return(&con->c.wr_cnt) % clt_path->s.signal_interval ? 481 0 : IB_SEND_SIGNALED; 482 483 ib_dma_sync_single_for_device(clt_path->s.dev->ib_dev, 484 req->iu->dma_addr, 485 req->sg_size, DMA_TO_DEVICE); 486 487 return rtrs_iu_post_rdma_write_imm(&con->c, req->iu, &sge, 1, 488 rbuf->rkey, rbuf->addr + off, 489 imm, flags, wr, NULL); 490 } 491 492 static void process_io_rsp(struct rtrs_clt_path *clt_path, u32 msg_id, 493 s16 errno, bool w_inval) 494 { 495 struct rtrs_clt_io_req *req; 496 497 if (WARN_ON(msg_id >= clt_path->queue_depth)) 498 return; 499 500 req = &clt_path->reqs[msg_id]; 501 /* Drop need_inv if server responded with send with invalidation */ 502 req->need_inv &= !w_inval; 503 complete_rdma_req(req, errno, true, false); 504 } 505 506 static void rtrs_clt_recv_done(struct rtrs_clt_con *con, struct ib_wc *wc) 507 { 508 struct rtrs_iu *iu; 509 int err; 510 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path); 511 512 WARN_ON((clt_path->flags & RTRS_MSG_NEW_RKEY_F) == 0); 513 iu = container_of(wc->wr_cqe, struct rtrs_iu, 514 cqe); 515 err = rtrs_iu_post_recv(&con->c, iu); 516 if (err) { 517 rtrs_err(con->c.path, "post iu failed %d\n", err); 518 rtrs_rdma_error_recovery(con); 519 } 520 } 521 522 static void rtrs_clt_rkey_rsp_done(struct rtrs_clt_con *con, struct ib_wc *wc) 523 { 524 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path); 525 struct rtrs_msg_rkey_rsp *msg; 526 u32 imm_type, imm_payload; 527 bool w_inval = false; 528 struct rtrs_iu *iu; 529 u32 buf_id; 530 int err; 531 532 WARN_ON((clt_path->flags & RTRS_MSG_NEW_RKEY_F) == 0); 533 534 iu = container_of(wc->wr_cqe, struct rtrs_iu, cqe); 535 536 if (wc->byte_len < sizeof(*msg)) { 537 rtrs_err(con->c.path, "rkey response is malformed: size %d\n", 538 wc->byte_len); 539 goto out; 540 } 541 ib_dma_sync_single_for_cpu(clt_path->s.dev->ib_dev, iu->dma_addr, 542 iu->size, DMA_FROM_DEVICE); 543 msg = iu->buf; 544 if (le16_to_cpu(msg->type) != RTRS_MSG_RKEY_RSP) { 545 rtrs_err(clt_path->clt, 546 "rkey response is malformed: type %d\n", 547 le16_to_cpu(msg->type)); 548 goto out; 549 } 550 buf_id = le16_to_cpu(msg->buf_id); 551 if (WARN_ON(buf_id >= clt_path->queue_depth)) 552 goto out; 553 554 rtrs_from_imm(be32_to_cpu(wc->ex.imm_data), &imm_type, &imm_payload); 555 if (imm_type == RTRS_IO_RSP_IMM || 556 imm_type == RTRS_IO_RSP_W_INV_IMM) { 557 u32 msg_id; 558 559 w_inval = (imm_type == RTRS_IO_RSP_W_INV_IMM); 560 rtrs_from_io_rsp_imm(imm_payload, &msg_id, &err); 561 562 if (WARN_ON(buf_id != msg_id)) 563 goto out; 564 clt_path->rbufs[buf_id].rkey = le32_to_cpu(msg->rkey); 565 process_io_rsp(clt_path, msg_id, err, w_inval); 566 } 567 ib_dma_sync_single_for_device(clt_path->s.dev->ib_dev, iu->dma_addr, 568 iu->size, DMA_FROM_DEVICE); 569 return rtrs_clt_recv_done(con, wc); 570 out: 571 rtrs_rdma_error_recovery(con); 572 } 573 574 static void rtrs_clt_rdma_done(struct ib_cq *cq, struct ib_wc *wc); 575 576 static struct ib_cqe io_comp_cqe = { 577 .done = rtrs_clt_rdma_done 578 }; 579 580 /* 581 * Post x2 empty WRs: first is for this RDMA with IMM, 582 * second is for RECV with INV, which happened earlier. 583 */ 584 static int rtrs_post_recv_empty_x2(struct rtrs_con *con, struct ib_cqe *cqe) 585 { 586 struct ib_recv_wr wr_arr[2], *wr; 587 int i; 588 589 memset(wr_arr, 0, sizeof(wr_arr)); 590 for (i = 0; i < ARRAY_SIZE(wr_arr); i++) { 591 wr = &wr_arr[i]; 592 wr->wr_cqe = cqe; 593 if (i) 594 /* Chain backwards */ 595 wr->next = &wr_arr[i - 1]; 596 } 597 598 return ib_post_recv(con->qp, wr, NULL); 599 } 600 601 static void rtrs_clt_rdma_done(struct ib_cq *cq, struct ib_wc *wc) 602 { 603 struct rtrs_clt_con *con = to_clt_con(wc->qp->qp_context); 604 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path); 605 u32 imm_type, imm_payload; 606 bool w_inval = false; 607 int err; 608 609 if (wc->status != IB_WC_SUCCESS) { 610 if (wc->status != IB_WC_WR_FLUSH_ERR) { 611 rtrs_err(clt_path->clt, "RDMA failed: %s\n", 612 ib_wc_status_msg(wc->status)); 613 rtrs_rdma_error_recovery(con); 614 } 615 return; 616 } 617 rtrs_clt_update_wc_stats(con); 618 619 switch (wc->opcode) { 620 case IB_WC_RECV_RDMA_WITH_IMM: 621 /* 622 * post_recv() RDMA write completions of IO reqs (read/write) 623 * and hb 624 */ 625 if (WARN_ON(wc->wr_cqe->done != rtrs_clt_rdma_done)) 626 return; 627 rtrs_from_imm(be32_to_cpu(wc->ex.imm_data), 628 &imm_type, &imm_payload); 629 if (imm_type == RTRS_IO_RSP_IMM || 630 imm_type == RTRS_IO_RSP_W_INV_IMM) { 631 u32 msg_id; 632 633 w_inval = (imm_type == RTRS_IO_RSP_W_INV_IMM); 634 rtrs_from_io_rsp_imm(imm_payload, &msg_id, &err); 635 636 process_io_rsp(clt_path, msg_id, err, w_inval); 637 } else if (imm_type == RTRS_HB_MSG_IMM) { 638 WARN_ON(con->c.cid); 639 rtrs_send_hb_ack(&clt_path->s); 640 if (clt_path->flags & RTRS_MSG_NEW_RKEY_F) 641 return rtrs_clt_recv_done(con, wc); 642 } else if (imm_type == RTRS_HB_ACK_IMM) { 643 WARN_ON(con->c.cid); 644 clt_path->s.hb_missed_cnt = 0; 645 clt_path->s.hb_cur_latency = 646 ktime_sub(ktime_get(), clt_path->s.hb_last_sent); 647 if (clt_path->flags & RTRS_MSG_NEW_RKEY_F) 648 return rtrs_clt_recv_done(con, wc); 649 } else { 650 rtrs_wrn(con->c.path, "Unknown IMM type %u\n", 651 imm_type); 652 } 653 if (w_inval) 654 /* 655 * Post x2 empty WRs: first is for this RDMA with IMM, 656 * second is for RECV with INV, which happened earlier. 657 */ 658 err = rtrs_post_recv_empty_x2(&con->c, &io_comp_cqe); 659 else 660 err = rtrs_post_recv_empty(&con->c, &io_comp_cqe); 661 if (err) { 662 rtrs_err(con->c.path, "rtrs_post_recv_empty(): %d\n", 663 err); 664 rtrs_rdma_error_recovery(con); 665 } 666 break; 667 case IB_WC_RECV: 668 /* 669 * Key invalidations from server side 670 */ 671 WARN_ON(!(wc->wc_flags & IB_WC_WITH_INVALIDATE || 672 wc->wc_flags & IB_WC_WITH_IMM)); 673 WARN_ON(wc->wr_cqe->done != rtrs_clt_rdma_done); 674 if (clt_path->flags & RTRS_MSG_NEW_RKEY_F) { 675 if (wc->wc_flags & IB_WC_WITH_INVALIDATE) 676 return rtrs_clt_recv_done(con, wc); 677 678 return rtrs_clt_rkey_rsp_done(con, wc); 679 } 680 break; 681 case IB_WC_RDMA_WRITE: 682 /* 683 * post_send() RDMA write completions of IO reqs (read/write) 684 * and hb. 685 */ 686 break; 687 688 default: 689 rtrs_wrn(clt_path->clt, "Unexpected WC type: %d\n", wc->opcode); 690 return; 691 } 692 } 693 694 static int post_recv_io(struct rtrs_clt_con *con, size_t q_size) 695 { 696 int err, i; 697 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path); 698 699 for (i = 0; i < q_size; i++) { 700 if (clt_path->flags & RTRS_MSG_NEW_RKEY_F) { 701 struct rtrs_iu *iu = &con->rsp_ius[i]; 702 703 err = rtrs_iu_post_recv(&con->c, iu); 704 } else { 705 err = rtrs_post_recv_empty(&con->c, &io_comp_cqe); 706 } 707 if (err) 708 return err; 709 } 710 711 return 0; 712 } 713 714 static int post_recv_path(struct rtrs_clt_path *clt_path) 715 { 716 size_t q_size = 0; 717 int err, cid; 718 719 for (cid = 0; cid < clt_path->s.con_num; cid++) { 720 if (cid == 0) 721 q_size = SERVICE_CON_QUEUE_DEPTH; 722 else 723 q_size = clt_path->queue_depth; 724 725 /* 726 * x2 for RDMA read responses + FR key invalidations, 727 * RDMA writes do not require any FR registrations. 728 */ 729 q_size *= 2; 730 731 err = post_recv_io(to_clt_con(clt_path->s.con[cid]), q_size); 732 if (err) { 733 rtrs_err(clt_path->clt, "post_recv_io(), err: %d\n", 734 err); 735 return err; 736 } 737 } 738 739 return 0; 740 } 741 742 struct path_it { 743 int i; 744 struct list_head skip_list; 745 struct rtrs_clt_sess *clt; 746 struct rtrs_clt_path *(*next_path)(struct path_it *it); 747 }; 748 749 /* 750 * rtrs_clt_get_next_path_or_null - get clt path from the list or return NULL 751 * @head: the head for the list. 752 * @clt_path: The element to take the next clt_path from. 753 * 754 * Next clt path returned in round-robin fashion, i.e. head will be skipped, 755 * but if list is observed as empty, NULL will be returned. 756 * 757 * This function may safely run concurrently with the _rcu list-mutation 758 * primitives such as list_add_rcu() as long as it's guarded by rcu_read_lock(). 759 */ 760 static inline struct rtrs_clt_path * 761 rtrs_clt_get_next_path_or_null(struct list_head *head, struct rtrs_clt_path *clt_path) 762 { 763 return list_next_or_null_rcu(head, &clt_path->s.entry, typeof(*clt_path), s.entry) ?: 764 list_next_or_null_rcu(head, 765 READ_ONCE((&clt_path->s.entry)->next), 766 typeof(*clt_path), s.entry); 767 } 768 769 /** 770 * get_next_path_rr() - Returns path in round-robin fashion. 771 * @it: the path pointer 772 * 773 * Related to @MP_POLICY_RR 774 * 775 * Locks: 776 * rcu_read_lock() must be hold. 777 */ 778 static struct rtrs_clt_path *get_next_path_rr(struct path_it *it) 779 { 780 struct rtrs_clt_path __rcu **ppcpu_path; 781 struct rtrs_clt_path *path; 782 struct rtrs_clt_sess *clt; 783 784 clt = it->clt; 785 786 /* 787 * Here we use two RCU objects: @paths_list and @pcpu_path 788 * pointer. See rtrs_clt_remove_path_from_arr() for details 789 * how that is handled. 790 */ 791 792 ppcpu_path = this_cpu_ptr(clt->pcpu_path); 793 path = rcu_dereference(*ppcpu_path); 794 if (!path) 795 path = list_first_or_null_rcu(&clt->paths_list, 796 typeof(*path), s.entry); 797 else 798 path = rtrs_clt_get_next_path_or_null(&clt->paths_list, path); 799 800 rcu_assign_pointer(*ppcpu_path, path); 801 802 return path; 803 } 804 805 /** 806 * get_next_path_min_inflight() - Returns path with minimal inflight count. 807 * @it: the path pointer 808 * 809 * Related to @MP_POLICY_MIN_INFLIGHT 810 * 811 * Locks: 812 * rcu_read_lock() must be hold. 813 */ 814 static struct rtrs_clt_path *get_next_path_min_inflight(struct path_it *it) 815 { 816 struct rtrs_clt_path *min_path = NULL; 817 struct rtrs_clt_sess *clt = it->clt; 818 struct rtrs_clt_path *clt_path; 819 int min_inflight = INT_MAX; 820 int inflight; 821 822 list_for_each_entry_rcu(clt_path, &clt->paths_list, s.entry) { 823 if (READ_ONCE(clt_path->state) != RTRS_CLT_CONNECTED) 824 continue; 825 826 if (!list_empty(raw_cpu_ptr(clt_path->mp_skip_entry))) 827 continue; 828 829 inflight = atomic_read(&clt_path->stats->inflight); 830 831 if (inflight < min_inflight) { 832 min_inflight = inflight; 833 min_path = clt_path; 834 } 835 } 836 837 /* 838 * add the path to the skip list, so that next time we can get 839 * a different one 840 */ 841 if (min_path) 842 list_add(raw_cpu_ptr(min_path->mp_skip_entry), &it->skip_list); 843 844 return min_path; 845 } 846 847 /** 848 * get_next_path_min_latency() - Returns path with minimal latency. 849 * @it: the path pointer 850 * 851 * Return: a path with the lowest latency or NULL if all paths are tried 852 * 853 * Locks: 854 * rcu_read_lock() must be hold. 855 * 856 * Related to @MP_POLICY_MIN_LATENCY 857 * 858 * This DOES skip an already-tried path. 859 * There is a skip-list to skip a path if the path has tried but failed. 860 * It will try the minimum latency path and then the second minimum latency 861 * path and so on. Finally it will return NULL if all paths are tried. 862 * Therefore the caller MUST check the returned 863 * path is NULL and trigger the IO error. 864 */ 865 static struct rtrs_clt_path *get_next_path_min_latency(struct path_it *it) 866 { 867 struct rtrs_clt_path *min_path = NULL; 868 struct rtrs_clt_sess *clt = it->clt; 869 struct rtrs_clt_path *clt_path; 870 ktime_t min_latency = KTIME_MAX; 871 ktime_t latency; 872 873 list_for_each_entry_rcu(clt_path, &clt->paths_list, s.entry) { 874 if (READ_ONCE(clt_path->state) != RTRS_CLT_CONNECTED) 875 continue; 876 877 if (!list_empty(raw_cpu_ptr(clt_path->mp_skip_entry))) 878 continue; 879 880 latency = clt_path->s.hb_cur_latency; 881 882 if (latency < min_latency) { 883 min_latency = latency; 884 min_path = clt_path; 885 } 886 } 887 888 /* 889 * add the path to the skip list, so that next time we can get 890 * a different one 891 */ 892 if (min_path) 893 list_add(raw_cpu_ptr(min_path->mp_skip_entry), &it->skip_list); 894 895 return min_path; 896 } 897 898 static inline void path_it_init(struct path_it *it, struct rtrs_clt_sess *clt) 899 { 900 INIT_LIST_HEAD(&it->skip_list); 901 it->clt = clt; 902 it->i = 0; 903 904 if (clt->mp_policy == MP_POLICY_RR) 905 it->next_path = get_next_path_rr; 906 else if (clt->mp_policy == MP_POLICY_MIN_INFLIGHT) 907 it->next_path = get_next_path_min_inflight; 908 else 909 it->next_path = get_next_path_min_latency; 910 } 911 912 static inline void path_it_deinit(struct path_it *it) 913 { 914 struct list_head *skip, *tmp; 915 /* 916 * The skip_list is used only for the MIN_INFLIGHT and MIN_LATENCY policies. 917 * We need to remove paths from it, so that next IO can insert 918 * paths (->mp_skip_entry) into a skip_list again. 919 */ 920 list_for_each_safe(skip, tmp, &it->skip_list) 921 list_del_init(skip); 922 } 923 924 /** 925 * rtrs_clt_init_req() - Initialize an rtrs_clt_io_req holding information 926 * about an inflight IO. 927 * The user buffer holding user control message (not data) is copied into 928 * the corresponding buffer of rtrs_iu (req->iu->buf), which later on will 929 * also hold the control message of rtrs. 930 * @req: an io request holding information about IO. 931 * @clt_path: client path 932 * @conf: conformation callback function to notify upper layer. 933 * @permit: permit for allocation of RDMA remote buffer 934 * @priv: private pointer 935 * @vec: kernel vector containing control message 936 * @usr_len: length of the user message 937 * @sg: scater list for IO data 938 * @sg_cnt: number of scater list entries 939 * @data_len: length of the IO data 940 * @dir: direction of the IO. 941 */ 942 static void rtrs_clt_init_req(struct rtrs_clt_io_req *req, 943 struct rtrs_clt_path *clt_path, 944 void (*conf)(void *priv, int errno), 945 struct rtrs_permit *permit, void *priv, 946 const struct kvec *vec, size_t usr_len, 947 struct scatterlist *sg, size_t sg_cnt, 948 size_t data_len, int dir) 949 { 950 struct iov_iter iter; 951 size_t len; 952 953 req->permit = permit; 954 req->in_use = true; 955 req->usr_len = usr_len; 956 req->data_len = data_len; 957 req->sglist = sg; 958 req->sg_cnt = sg_cnt; 959 req->priv = priv; 960 req->dir = dir; 961 req->con = rtrs_permit_to_clt_con(clt_path, permit); 962 req->conf = conf; 963 req->need_inv = false; 964 req->need_inv_comp = false; 965 req->inv_errno = 0; 966 refcount_set(&req->ref, 1); 967 req->mp_policy = clt_path->clt->mp_policy; 968 969 iov_iter_kvec(&iter, ITER_SOURCE, vec, 1, usr_len); 970 len = _copy_from_iter(req->iu->buf, usr_len, &iter); 971 WARN_ON(len != usr_len); 972 973 reinit_completion(&req->inv_comp); 974 } 975 976 static struct rtrs_clt_io_req * 977 rtrs_clt_get_req(struct rtrs_clt_path *clt_path, 978 void (*conf)(void *priv, int errno), 979 struct rtrs_permit *permit, void *priv, 980 const struct kvec *vec, size_t usr_len, 981 struct scatterlist *sg, size_t sg_cnt, 982 size_t data_len, int dir) 983 { 984 struct rtrs_clt_io_req *req; 985 986 req = &clt_path->reqs[permit->mem_id]; 987 rtrs_clt_init_req(req, clt_path, conf, permit, priv, vec, usr_len, 988 sg, sg_cnt, data_len, dir); 989 return req; 990 } 991 992 static struct rtrs_clt_io_req * 993 rtrs_clt_get_copy_req(struct rtrs_clt_path *alive_path, 994 struct rtrs_clt_io_req *fail_req) 995 { 996 struct rtrs_clt_io_req *req; 997 struct kvec vec = { 998 .iov_base = fail_req->iu->buf, 999 .iov_len = fail_req->usr_len 1000 }; 1001 1002 req = &alive_path->reqs[fail_req->permit->mem_id]; 1003 rtrs_clt_init_req(req, alive_path, fail_req->conf, fail_req->permit, 1004 fail_req->priv, &vec, fail_req->usr_len, 1005 fail_req->sglist, fail_req->sg_cnt, 1006 fail_req->data_len, fail_req->dir); 1007 return req; 1008 } 1009 1010 static int rtrs_post_rdma_write_sg(struct rtrs_clt_con *con, 1011 struct rtrs_clt_io_req *req, 1012 struct rtrs_rbuf *rbuf, bool fr_en, 1013 u32 count, u32 size, u32 imm, 1014 struct ib_send_wr *wr, 1015 struct ib_send_wr *tail) 1016 { 1017 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path); 1018 struct ib_sge *sge = req->sge; 1019 enum ib_send_flags flags; 1020 struct scatterlist *sg; 1021 size_t num_sge; 1022 int i; 1023 struct ib_send_wr *ptail = NULL; 1024 1025 if (fr_en) { 1026 i = 0; 1027 sge[i].addr = req->mr->iova; 1028 sge[i].length = req->mr->length; 1029 sge[i].lkey = req->mr->lkey; 1030 i++; 1031 num_sge = 2; 1032 ptail = tail; 1033 } else { 1034 for_each_sg(req->sglist, sg, count, i) { 1035 sge[i].addr = sg_dma_address(sg); 1036 sge[i].length = sg_dma_len(sg); 1037 sge[i].lkey = clt_path->s.dev->ib_pd->local_dma_lkey; 1038 } 1039 num_sge = 1 + count; 1040 } 1041 sge[i].addr = req->iu->dma_addr; 1042 sge[i].length = size; 1043 sge[i].lkey = clt_path->s.dev->ib_pd->local_dma_lkey; 1044 1045 /* 1046 * From time to time we have to post signalled sends, 1047 * or send queue will fill up and only QP reset can help. 1048 */ 1049 flags = atomic_inc_return(&con->c.wr_cnt) % clt_path->s.signal_interval ? 1050 0 : IB_SEND_SIGNALED; 1051 1052 ib_dma_sync_single_for_device(clt_path->s.dev->ib_dev, 1053 req->iu->dma_addr, 1054 size, DMA_TO_DEVICE); 1055 1056 return rtrs_iu_post_rdma_write_imm(&con->c, req->iu, sge, num_sge, 1057 rbuf->rkey, rbuf->addr, imm, 1058 flags, wr, ptail); 1059 } 1060 1061 static int rtrs_map_sg_fr(struct rtrs_clt_io_req *req, size_t count) 1062 { 1063 int nr; 1064 1065 /* Align the MR to a 4K page size to match the block virt boundary */ 1066 nr = ib_map_mr_sg(req->mr, req->sglist, count, NULL, SZ_4K); 1067 if (nr != count) 1068 return nr < 0 ? nr : -EINVAL; 1069 ib_update_fast_reg_key(req->mr, ib_inc_rkey(req->mr->rkey)); 1070 1071 return nr; 1072 } 1073 1074 static int rtrs_clt_write_req(struct rtrs_clt_io_req *req) 1075 { 1076 struct rtrs_clt_con *con = req->con; 1077 struct rtrs_path *s = con->c.path; 1078 struct rtrs_clt_path *clt_path = to_clt_path(s); 1079 struct rtrs_msg_rdma_write *msg; 1080 1081 struct rtrs_rbuf *rbuf; 1082 int ret, count = 0; 1083 u32 imm, buf_id; 1084 struct ib_reg_wr rwr; 1085 struct ib_send_wr inv_wr; 1086 struct ib_send_wr *wr = NULL; 1087 bool fr_en = false; 1088 1089 const size_t tsize = sizeof(*msg) + req->data_len + req->usr_len; 1090 1091 if (tsize > clt_path->chunk_size) { 1092 rtrs_wrn(s, "Write request failed, size too big %zu > %d\n", 1093 tsize, clt_path->chunk_size); 1094 return -EMSGSIZE; 1095 } 1096 if (req->sg_cnt) { 1097 count = ib_dma_map_sg(clt_path->s.dev->ib_dev, req->sglist, 1098 req->sg_cnt, req->dir); 1099 if (!count) { 1100 rtrs_wrn(s, "Write request failed, map failed\n"); 1101 return -EINVAL; 1102 } 1103 } 1104 /* put rtrs msg after sg and user message */ 1105 msg = req->iu->buf + req->usr_len; 1106 msg->type = cpu_to_le16(RTRS_MSG_WRITE); 1107 msg->usr_len = cpu_to_le16(req->usr_len); 1108 1109 /* rtrs message on server side will be after user data and message */ 1110 imm = req->permit->mem_off + req->data_len + req->usr_len; 1111 imm = rtrs_to_io_req_imm(imm); 1112 buf_id = req->permit->mem_id; 1113 req->sg_size = tsize; 1114 rbuf = &clt_path->rbufs[buf_id]; 1115 1116 if (count) { 1117 ret = rtrs_map_sg_fr(req, count); 1118 if (ret < 0) { 1119 rtrs_err_rl(s, 1120 "Write request failed, failed to map fast reg. data, err: %d\n", 1121 ret); 1122 ib_dma_unmap_sg(clt_path->s.dev->ib_dev, req->sglist, 1123 req->sg_cnt, req->dir); 1124 return ret; 1125 } 1126 inv_wr = (struct ib_send_wr) { 1127 .opcode = IB_WR_LOCAL_INV, 1128 .wr_cqe = &req->inv_cqe, 1129 .send_flags = IB_SEND_SIGNALED, 1130 .ex.invalidate_rkey = req->mr->rkey, 1131 }; 1132 req->inv_cqe.done = rtrs_clt_inv_rkey_done; 1133 rwr = (struct ib_reg_wr) { 1134 .wr.opcode = IB_WR_REG_MR, 1135 .wr.wr_cqe = &fast_reg_cqe, 1136 .mr = req->mr, 1137 .key = req->mr->rkey, 1138 .access = (IB_ACCESS_LOCAL_WRITE), 1139 }; 1140 wr = &rwr.wr; 1141 fr_en = true; 1142 refcount_inc(&req->ref); 1143 } 1144 /* 1145 * Update stats now, after request is successfully sent it is not 1146 * safe anymore to touch it. 1147 */ 1148 rtrs_clt_update_all_stats(req, WRITE); 1149 1150 ret = rtrs_post_rdma_write_sg(req->con, req, rbuf, fr_en, count, 1151 req->usr_len + sizeof(*msg), 1152 imm, wr, &inv_wr); 1153 if (ret) { 1154 rtrs_err_rl(s, 1155 "Write request failed: error=%d path=%s [%s:%u]\n", 1156 ret, kobject_name(&clt_path->kobj), clt_path->hca_name, 1157 clt_path->hca_port); 1158 if (req->mp_policy == MP_POLICY_MIN_INFLIGHT) 1159 atomic_dec(&clt_path->stats->inflight); 1160 if (req->sg_cnt) 1161 ib_dma_unmap_sg(clt_path->s.dev->ib_dev, req->sglist, 1162 req->sg_cnt, req->dir); 1163 } 1164 1165 return ret; 1166 } 1167 1168 static int rtrs_clt_read_req(struct rtrs_clt_io_req *req) 1169 { 1170 struct rtrs_clt_con *con = req->con; 1171 struct rtrs_path *s = con->c.path; 1172 struct rtrs_clt_path *clt_path = to_clt_path(s); 1173 struct rtrs_msg_rdma_read *msg; 1174 struct rtrs_ib_dev *dev = clt_path->s.dev; 1175 1176 struct ib_reg_wr rwr; 1177 struct ib_send_wr *wr = NULL; 1178 1179 int ret, count = 0; 1180 u32 imm, buf_id; 1181 1182 const size_t tsize = sizeof(*msg) + req->data_len + req->usr_len; 1183 1184 if (tsize > clt_path->chunk_size) { 1185 rtrs_wrn(s, 1186 "Read request failed, message size is %zu, bigger than CHUNK_SIZE %d\n", 1187 tsize, clt_path->chunk_size); 1188 return -EMSGSIZE; 1189 } 1190 1191 if (req->sg_cnt) { 1192 count = ib_dma_map_sg(dev->ib_dev, req->sglist, req->sg_cnt, 1193 req->dir); 1194 if (!count) { 1195 rtrs_wrn(s, 1196 "Read request failed, dma map failed\n"); 1197 return -EINVAL; 1198 } 1199 } 1200 /* put our message into req->buf after user message*/ 1201 msg = req->iu->buf + req->usr_len; 1202 msg->type = cpu_to_le16(RTRS_MSG_READ); 1203 msg->usr_len = cpu_to_le16(req->usr_len); 1204 1205 if (count) { 1206 ret = rtrs_map_sg_fr(req, count); 1207 if (ret < 0) { 1208 rtrs_err_rl(s, 1209 "Read request failed, failed to map fast reg. data, err: %d\n", 1210 ret); 1211 ib_dma_unmap_sg(dev->ib_dev, req->sglist, req->sg_cnt, 1212 req->dir); 1213 return ret; 1214 } 1215 rwr = (struct ib_reg_wr) { 1216 .wr.opcode = IB_WR_REG_MR, 1217 .wr.wr_cqe = &fast_reg_cqe, 1218 .mr = req->mr, 1219 .key = req->mr->rkey, 1220 .access = (IB_ACCESS_LOCAL_WRITE | 1221 IB_ACCESS_REMOTE_WRITE), 1222 }; 1223 wr = &rwr.wr; 1224 1225 msg->sg_cnt = cpu_to_le16(1); 1226 msg->flags = cpu_to_le16(RTRS_MSG_NEED_INVAL_F); 1227 1228 msg->desc[0].addr = cpu_to_le64(req->mr->iova); 1229 msg->desc[0].key = cpu_to_le32(req->mr->rkey); 1230 msg->desc[0].len = cpu_to_le32(req->mr->length); 1231 1232 /* Further invalidation is required */ 1233 req->need_inv = !!RTRS_MSG_NEED_INVAL_F; 1234 1235 } else { 1236 msg->sg_cnt = 0; 1237 msg->flags = 0; 1238 } 1239 /* 1240 * rtrs message will be after the space reserved for disk data and 1241 * user message 1242 */ 1243 imm = req->permit->mem_off + req->data_len + req->usr_len; 1244 imm = rtrs_to_io_req_imm(imm); 1245 buf_id = req->permit->mem_id; 1246 1247 req->sg_size = sizeof(*msg); 1248 req->sg_size += le16_to_cpu(msg->sg_cnt) * sizeof(struct rtrs_sg_desc); 1249 req->sg_size += req->usr_len; 1250 1251 /* 1252 * Update stats now, after request is successfully sent it is not 1253 * safe anymore to touch it. 1254 */ 1255 rtrs_clt_update_all_stats(req, READ); 1256 1257 ret = rtrs_post_send_rdma(req->con, req, &clt_path->rbufs[buf_id], 1258 req->data_len, imm, wr); 1259 if (ret) { 1260 rtrs_err_rl(s, 1261 "Read request failed: error=%d path=%s [%s:%u]\n", 1262 ret, kobject_name(&clt_path->kobj), clt_path->hca_name, 1263 clt_path->hca_port); 1264 if (req->mp_policy == MP_POLICY_MIN_INFLIGHT) 1265 atomic_dec(&clt_path->stats->inflight); 1266 req->need_inv = false; 1267 if (req->sg_cnt) 1268 ib_dma_unmap_sg(dev->ib_dev, req->sglist, 1269 req->sg_cnt, req->dir); 1270 } 1271 1272 return ret; 1273 } 1274 1275 /** 1276 * rtrs_clt_failover_req() - Try to find an active path for a failed request 1277 * @clt: clt context 1278 * @fail_req: a failed io request. 1279 */ 1280 static int rtrs_clt_failover_req(struct rtrs_clt_sess *clt, 1281 struct rtrs_clt_io_req *fail_req) 1282 { 1283 struct rtrs_clt_path *alive_path; 1284 struct rtrs_clt_io_req *req; 1285 int err = -ECONNABORTED; 1286 struct path_it it; 1287 1288 rcu_read_lock(); 1289 for (path_it_init(&it, clt); 1290 (alive_path = it.next_path(&it)) && it.i < it.clt->paths_num; 1291 it.i++) { 1292 if (READ_ONCE(alive_path->state) != RTRS_CLT_CONNECTED) 1293 continue; 1294 req = rtrs_clt_get_copy_req(alive_path, fail_req); 1295 if (req->dir == DMA_TO_DEVICE) 1296 err = rtrs_clt_write_req(req); 1297 else 1298 err = rtrs_clt_read_req(req); 1299 if (err) { 1300 req->in_use = false; 1301 continue; 1302 } 1303 /* Success path */ 1304 rtrs_clt_inc_failover_cnt(alive_path->stats); 1305 break; 1306 } 1307 path_it_deinit(&it); 1308 rcu_read_unlock(); 1309 1310 return err; 1311 } 1312 1313 static void fail_all_outstanding_reqs(struct rtrs_clt_path *clt_path) 1314 { 1315 struct rtrs_clt_sess *clt = clt_path->clt; 1316 struct rtrs_clt_io_req *req; 1317 int i, err; 1318 1319 if (!clt_path->reqs) 1320 return; 1321 for (i = 0; i < clt_path->queue_depth; ++i) { 1322 req = &clt_path->reqs[i]; 1323 if (!req->in_use) 1324 continue; 1325 1326 /* 1327 * Safely (without notification) complete failed request. 1328 * After completion this request is still useble and can 1329 * be failovered to another path. 1330 */ 1331 complete_rdma_req(req, -ECONNABORTED, false, true); 1332 1333 err = rtrs_clt_failover_req(clt, req); 1334 if (err) 1335 /* Failover failed, notify anyway */ 1336 req->conf(req->priv, err); 1337 } 1338 } 1339 1340 static void free_path_reqs(struct rtrs_clt_path *clt_path) 1341 { 1342 struct rtrs_clt_io_req *req; 1343 int i; 1344 1345 if (!clt_path->reqs) 1346 return; 1347 for (i = 0; i < clt_path->queue_depth; ++i) { 1348 req = &clt_path->reqs[i]; 1349 if (req->mr) 1350 ib_dereg_mr(req->mr); 1351 kfree(req->sge); 1352 rtrs_iu_free(req->iu, clt_path->s.dev->ib_dev, 1); 1353 } 1354 kfree(clt_path->reqs); 1355 clt_path->reqs = NULL; 1356 } 1357 1358 static int alloc_path_reqs(struct rtrs_clt_path *clt_path) 1359 { 1360 struct rtrs_clt_io_req *req; 1361 int i, err = -ENOMEM; 1362 1363 clt_path->reqs = kcalloc(clt_path->queue_depth, 1364 sizeof(*clt_path->reqs), 1365 GFP_KERNEL); 1366 if (!clt_path->reqs) 1367 return -ENOMEM; 1368 1369 for (i = 0; i < clt_path->queue_depth; ++i) { 1370 req = &clt_path->reqs[i]; 1371 req->iu = rtrs_iu_alloc(1, clt_path->max_hdr_size, GFP_KERNEL, 1372 clt_path->s.dev->ib_dev, 1373 DMA_TO_DEVICE, 1374 rtrs_clt_rdma_done); 1375 if (!req->iu) 1376 goto out; 1377 1378 req->sge = kcalloc(2, sizeof(*req->sge), GFP_KERNEL); 1379 if (!req->sge) 1380 goto out; 1381 1382 req->mr = ib_alloc_mr(clt_path->s.dev->ib_pd, 1383 IB_MR_TYPE_MEM_REG, 1384 clt_path->max_pages_per_mr); 1385 if (IS_ERR(req->mr)) { 1386 err = PTR_ERR(req->mr); 1387 req->mr = NULL; 1388 pr_err("Failed to alloc clt_path->max_pages_per_mr %d\n", 1389 clt_path->max_pages_per_mr); 1390 goto out; 1391 } 1392 1393 init_completion(&req->inv_comp); 1394 } 1395 1396 return 0; 1397 1398 out: 1399 free_path_reqs(clt_path); 1400 1401 return err; 1402 } 1403 1404 static int alloc_permits(struct rtrs_clt_sess *clt) 1405 { 1406 unsigned int chunk_bits; 1407 int err, i; 1408 1409 clt->permits_map = bitmap_zalloc(clt->queue_depth, GFP_KERNEL); 1410 if (!clt->permits_map) { 1411 err = -ENOMEM; 1412 goto out_err; 1413 } 1414 clt->permits = kcalloc(clt->queue_depth, permit_size(clt), GFP_KERNEL); 1415 if (!clt->permits) { 1416 err = -ENOMEM; 1417 goto err_map; 1418 } 1419 chunk_bits = ilog2(clt->queue_depth - 1) + 1; 1420 for (i = 0; i < clt->queue_depth; i++) { 1421 struct rtrs_permit *permit; 1422 1423 permit = get_permit(clt, i); 1424 permit->mem_id = i; 1425 permit->mem_off = i << (MAX_IMM_PAYL_BITS - chunk_bits); 1426 } 1427 1428 return 0; 1429 1430 err_map: 1431 bitmap_free(clt->permits_map); 1432 clt->permits_map = NULL; 1433 out_err: 1434 return err; 1435 } 1436 1437 static void free_permits(struct rtrs_clt_sess *clt) 1438 { 1439 if (clt->permits_map) 1440 wait_event(clt->permits_wait, 1441 bitmap_empty(clt->permits_map, clt->queue_depth)); 1442 1443 bitmap_free(clt->permits_map); 1444 clt->permits_map = NULL; 1445 kfree(clt->permits); 1446 clt->permits = NULL; 1447 } 1448 1449 static void query_fast_reg_mode(struct rtrs_clt_path *clt_path) 1450 { 1451 struct ib_device *ib_dev; 1452 u64 max_pages_per_mr; 1453 int mr_page_shift; 1454 1455 ib_dev = clt_path->s.dev->ib_dev; 1456 1457 /* 1458 * Use the smallest page size supported by the HCA, down to a 1459 * minimum of 4096 bytes. We're unlikely to build large sglists 1460 * out of smaller entries. 1461 */ 1462 mr_page_shift = max(12, ffs(ib_dev->attrs.page_size_cap) - 1); 1463 max_pages_per_mr = ib_dev->attrs.max_mr_size; 1464 do_div(max_pages_per_mr, (1ull << mr_page_shift)); 1465 clt_path->max_pages_per_mr = 1466 min3(clt_path->max_pages_per_mr, (u32)max_pages_per_mr, 1467 ib_dev->attrs.max_fast_reg_page_list_len); 1468 clt_path->clt->max_segments = 1469 min(clt_path->max_pages_per_mr, clt_path->clt->max_segments); 1470 } 1471 1472 static bool rtrs_clt_change_state_get_old(struct rtrs_clt_path *clt_path, 1473 enum rtrs_clt_state new_state, 1474 enum rtrs_clt_state *old_state) 1475 { 1476 bool changed; 1477 1478 spin_lock_irq(&clt_path->state_wq.lock); 1479 if (old_state) 1480 *old_state = clt_path->state; 1481 changed = rtrs_clt_change_state(clt_path, new_state); 1482 spin_unlock_irq(&clt_path->state_wq.lock); 1483 1484 return changed; 1485 } 1486 1487 static void rtrs_clt_hb_err_handler(struct rtrs_con *c) 1488 { 1489 struct rtrs_clt_con *con = container_of(c, typeof(*con), c); 1490 1491 rtrs_rdma_error_recovery(con); 1492 } 1493 1494 static void rtrs_clt_init_hb(struct rtrs_clt_path *clt_path) 1495 { 1496 rtrs_init_hb(&clt_path->s, &io_comp_cqe, 1497 RTRS_HB_INTERVAL_MS, 1498 RTRS_HB_MISSED_MAX, 1499 rtrs_clt_hb_err_handler, 1500 rtrs_wq); 1501 } 1502 1503 static void rtrs_clt_reconnect_work(struct work_struct *work); 1504 static void rtrs_clt_close_work(struct work_struct *work); 1505 1506 static void rtrs_clt_err_recovery_work(struct work_struct *work) 1507 { 1508 struct rtrs_clt_path *clt_path; 1509 struct rtrs_clt_sess *clt; 1510 int delay_ms; 1511 1512 clt_path = container_of(work, struct rtrs_clt_path, err_recovery_work); 1513 clt = clt_path->clt; 1514 delay_ms = clt->reconnect_delay_sec * 1000; 1515 rtrs_clt_stop_and_destroy_conns(clt_path); 1516 queue_delayed_work(rtrs_wq, &clt_path->reconnect_dwork, 1517 msecs_to_jiffies(delay_ms + 1518 get_random_u32_below(RTRS_RECONNECT_SEED))); 1519 } 1520 1521 static struct rtrs_clt_path *alloc_path(struct rtrs_clt_sess *clt, 1522 const struct rtrs_addr *path, 1523 size_t con_num, u32 nr_poll_queues) 1524 { 1525 struct rtrs_clt_path *clt_path; 1526 int err = -ENOMEM; 1527 int cpu; 1528 size_t total_con; 1529 1530 clt_path = kzalloc(sizeof(*clt_path), GFP_KERNEL); 1531 if (!clt_path) 1532 goto err; 1533 1534 /* 1535 * irqmode and poll 1536 * +1: Extra connection for user messages 1537 */ 1538 total_con = con_num + nr_poll_queues + 1; 1539 clt_path->s.con = kcalloc(total_con, sizeof(*clt_path->s.con), 1540 GFP_KERNEL); 1541 if (!clt_path->s.con) 1542 goto err_free_path; 1543 1544 clt_path->s.con_num = total_con; 1545 clt_path->s.irq_con_num = con_num + 1; 1546 1547 clt_path->stats = kzalloc(sizeof(*clt_path->stats), GFP_KERNEL); 1548 if (!clt_path->stats) 1549 goto err_free_con; 1550 1551 mutex_init(&clt_path->init_mutex); 1552 uuid_gen(&clt_path->s.uuid); 1553 memcpy(&clt_path->s.dst_addr, path->dst, 1554 rdma_addr_size((struct sockaddr *)path->dst)); 1555 1556 /* 1557 * rdma_resolve_addr() passes src_addr to cma_bind_addr, which 1558 * checks the sa_family to be non-zero. If user passed src_addr=NULL 1559 * the sess->src_addr will contain only zeros, which is then fine. 1560 */ 1561 if (path->src) 1562 memcpy(&clt_path->s.src_addr, path->src, 1563 rdma_addr_size((struct sockaddr *)path->src)); 1564 strscpy(clt_path->s.sessname, clt->sessname, 1565 sizeof(clt_path->s.sessname)); 1566 clt_path->clt = clt; 1567 clt_path->max_pages_per_mr = RTRS_MAX_SEGMENTS; 1568 init_waitqueue_head(&clt_path->state_wq); 1569 clt_path->state = RTRS_CLT_CONNECTING; 1570 atomic_set(&clt_path->connected_cnt, 0); 1571 INIT_WORK(&clt_path->close_work, rtrs_clt_close_work); 1572 INIT_WORK(&clt_path->err_recovery_work, rtrs_clt_err_recovery_work); 1573 INIT_DELAYED_WORK(&clt_path->reconnect_dwork, rtrs_clt_reconnect_work); 1574 rtrs_clt_init_hb(clt_path); 1575 1576 clt_path->mp_skip_entry = alloc_percpu(typeof(*clt_path->mp_skip_entry)); 1577 if (!clt_path->mp_skip_entry) 1578 goto err_free_stats; 1579 1580 for_each_possible_cpu(cpu) 1581 INIT_LIST_HEAD(per_cpu_ptr(clt_path->mp_skip_entry, cpu)); 1582 1583 err = rtrs_clt_init_stats(clt_path->stats); 1584 if (err) 1585 goto err_free_percpu; 1586 1587 return clt_path; 1588 1589 err_free_percpu: 1590 free_percpu(clt_path->mp_skip_entry); 1591 err_free_stats: 1592 kfree(clt_path->stats); 1593 err_free_con: 1594 kfree(clt_path->s.con); 1595 err_free_path: 1596 kfree(clt_path); 1597 err: 1598 return ERR_PTR(err); 1599 } 1600 1601 void free_path(struct rtrs_clt_path *clt_path) 1602 { 1603 free_percpu(clt_path->mp_skip_entry); 1604 mutex_destroy(&clt_path->init_mutex); 1605 kfree(clt_path->s.con); 1606 kfree(clt_path->rbufs); 1607 kfree(clt_path); 1608 } 1609 1610 static int create_con(struct rtrs_clt_path *clt_path, unsigned int cid) 1611 { 1612 struct rtrs_clt_con *con; 1613 1614 con = kzalloc(sizeof(*con), GFP_KERNEL); 1615 if (!con) 1616 return -ENOMEM; 1617 1618 /* Map first two connections to the first CPU */ 1619 con->cpu = (cid ? cid - 1 : 0) % nr_cpu_ids; 1620 con->c.cid = cid; 1621 con->c.path = &clt_path->s; 1622 /* Align with srv, init as 1 */ 1623 atomic_set(&con->c.wr_cnt, 1); 1624 mutex_init(&con->con_mutex); 1625 1626 clt_path->s.con[cid] = &con->c; 1627 1628 return 0; 1629 } 1630 1631 static void destroy_con(struct rtrs_clt_con *con) 1632 { 1633 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path); 1634 1635 clt_path->s.con[con->c.cid] = NULL; 1636 mutex_destroy(&con->con_mutex); 1637 kfree(con); 1638 } 1639 1640 static int create_con_cq_qp(struct rtrs_clt_con *con) 1641 { 1642 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path); 1643 u32 max_send_wr, max_recv_wr, cq_num, max_send_sge, wr_limit; 1644 int err, cq_vector; 1645 struct rtrs_msg_rkey_rsp *rsp; 1646 1647 lockdep_assert_held(&con->con_mutex); 1648 if (con->c.cid == 0) { 1649 max_send_sge = 1; 1650 /* We must be the first here */ 1651 if (WARN_ON(clt_path->s.dev)) 1652 return -EINVAL; 1653 1654 /* 1655 * The whole session uses device from user connection. 1656 * Be careful not to close user connection before ib dev 1657 * is gracefully put. 1658 */ 1659 clt_path->s.dev = rtrs_ib_dev_find_or_add(con->c.cm_id->device, 1660 &dev_pd); 1661 if (!clt_path->s.dev) { 1662 rtrs_wrn(clt_path->clt, 1663 "rtrs_ib_dev_find_get_or_add(): no memory\n"); 1664 return -ENOMEM; 1665 } 1666 clt_path->s.dev_ref = 1; 1667 query_fast_reg_mode(clt_path); 1668 wr_limit = clt_path->s.dev->ib_dev->attrs.max_qp_wr; 1669 /* 1670 * Two (request + registration) completion for send 1671 * Two for recv if always_invalidate is set on server 1672 * or one for recv. 1673 * + 2 for drain and heartbeat 1674 * in case qp gets into error state. 1675 */ 1676 max_send_wr = 1677 min_t(int, wr_limit, SERVICE_CON_QUEUE_DEPTH * 2 + 2); 1678 max_recv_wr = max_send_wr; 1679 } else { 1680 /* 1681 * Here we assume that session members are correctly set. 1682 * This is always true if user connection (cid == 0) is 1683 * established first. 1684 */ 1685 if (WARN_ON(!clt_path->s.dev)) 1686 return -EINVAL; 1687 if (WARN_ON(!clt_path->queue_depth)) 1688 return -EINVAL; 1689 1690 wr_limit = clt_path->s.dev->ib_dev->attrs.max_qp_wr; 1691 /* Shared between connections */ 1692 clt_path->s.dev_ref++; 1693 max_send_wr = min_t(int, wr_limit, 1694 /* QD * (REQ + RSP + FR REGS or INVS) + drain */ 1695 clt_path->queue_depth * 3 + 1); 1696 max_recv_wr = min_t(int, wr_limit, 1697 clt_path->queue_depth * 3 + 1); 1698 max_send_sge = 2; 1699 } 1700 atomic_set(&con->c.sq_wr_avail, max_send_wr); 1701 cq_num = max_send_wr + max_recv_wr; 1702 /* alloc iu to recv new rkey reply when server reports flags set */ 1703 if (clt_path->flags & RTRS_MSG_NEW_RKEY_F || con->c.cid == 0) { 1704 con->rsp_ius = rtrs_iu_alloc(cq_num, sizeof(*rsp), 1705 GFP_KERNEL, 1706 clt_path->s.dev->ib_dev, 1707 DMA_FROM_DEVICE, 1708 rtrs_clt_rdma_done); 1709 if (!con->rsp_ius) 1710 return -ENOMEM; 1711 con->queue_num = cq_num; 1712 } 1713 cq_vector = con->cpu % clt_path->s.dev->ib_dev->num_comp_vectors; 1714 if (con->c.cid >= clt_path->s.irq_con_num) 1715 err = rtrs_cq_qp_create(&clt_path->s, &con->c, max_send_sge, 1716 cq_vector, cq_num, max_send_wr, 1717 max_recv_wr, IB_POLL_DIRECT); 1718 else 1719 err = rtrs_cq_qp_create(&clt_path->s, &con->c, max_send_sge, 1720 cq_vector, cq_num, max_send_wr, 1721 max_recv_wr, IB_POLL_SOFTIRQ); 1722 /* 1723 * In case of error we do not bother to clean previous allocations, 1724 * since destroy_con_cq_qp() must be called. 1725 */ 1726 return err; 1727 } 1728 1729 static void destroy_con_cq_qp(struct rtrs_clt_con *con) 1730 { 1731 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path); 1732 1733 /* 1734 * Be careful here: destroy_con_cq_qp() can be called even 1735 * create_con_cq_qp() failed, see comments there. 1736 */ 1737 lockdep_assert_held(&con->con_mutex); 1738 rtrs_cq_qp_destroy(&con->c); 1739 if (con->rsp_ius) { 1740 rtrs_iu_free(con->rsp_ius, clt_path->s.dev->ib_dev, 1741 con->queue_num); 1742 con->rsp_ius = NULL; 1743 con->queue_num = 0; 1744 } 1745 if (clt_path->s.dev_ref && !--clt_path->s.dev_ref) { 1746 rtrs_ib_dev_put(clt_path->s.dev); 1747 clt_path->s.dev = NULL; 1748 } 1749 } 1750 1751 static void stop_cm(struct rtrs_clt_con *con) 1752 { 1753 rdma_disconnect(con->c.cm_id); 1754 if (con->c.qp) 1755 ib_drain_qp(con->c.qp); 1756 } 1757 1758 static void destroy_cm(struct rtrs_clt_con *con) 1759 { 1760 rdma_destroy_id(con->c.cm_id); 1761 con->c.cm_id = NULL; 1762 } 1763 1764 static int rtrs_rdma_addr_resolved(struct rtrs_clt_con *con) 1765 { 1766 struct rtrs_path *s = con->c.path; 1767 int err; 1768 1769 mutex_lock(&con->con_mutex); 1770 err = create_con_cq_qp(con); 1771 mutex_unlock(&con->con_mutex); 1772 if (err) { 1773 rtrs_err(s, "create_con_cq_qp(), err: %d\n", err); 1774 return err; 1775 } 1776 err = rdma_resolve_route(con->c.cm_id, RTRS_CONNECT_TIMEOUT_MS); 1777 if (err) 1778 rtrs_err(s, "Resolving route failed, err: %d\n", err); 1779 1780 return err; 1781 } 1782 1783 static int rtrs_rdma_route_resolved(struct rtrs_clt_con *con) 1784 { 1785 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path); 1786 struct rtrs_clt_sess *clt = clt_path->clt; 1787 struct rtrs_msg_conn_req msg; 1788 struct rdma_conn_param param; 1789 1790 int err; 1791 1792 param = (struct rdma_conn_param) { 1793 .retry_count = 7, 1794 .rnr_retry_count = 7, 1795 .private_data = &msg, 1796 .private_data_len = sizeof(msg), 1797 }; 1798 1799 msg = (struct rtrs_msg_conn_req) { 1800 .magic = cpu_to_le16(RTRS_MAGIC), 1801 .version = cpu_to_le16(RTRS_PROTO_VER), 1802 .cid = cpu_to_le16(con->c.cid), 1803 .cid_num = cpu_to_le16(clt_path->s.con_num), 1804 .recon_cnt = cpu_to_le16(clt_path->s.recon_cnt), 1805 }; 1806 msg.first_conn = clt_path->for_new_clt ? FIRST_CONN : 0; 1807 uuid_copy(&msg.sess_uuid, &clt_path->s.uuid); 1808 uuid_copy(&msg.paths_uuid, &clt->paths_uuid); 1809 1810 err = rdma_connect_locked(con->c.cm_id, ¶m); 1811 if (err) 1812 rtrs_err(clt, "rdma_connect_locked(): %d\n", err); 1813 1814 return err; 1815 } 1816 1817 static int rtrs_rdma_conn_established(struct rtrs_clt_con *con, 1818 struct rdma_cm_event *ev) 1819 { 1820 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path); 1821 struct rtrs_clt_sess *clt = clt_path->clt; 1822 const struct rtrs_msg_conn_rsp *msg; 1823 u16 version, queue_depth; 1824 int errno; 1825 u8 len; 1826 1827 msg = ev->param.conn.private_data; 1828 len = ev->param.conn.private_data_len; 1829 if (len < sizeof(*msg)) { 1830 rtrs_err(clt, "Invalid RTRS connection response\n"); 1831 return -ECONNRESET; 1832 } 1833 if (le16_to_cpu(msg->magic) != RTRS_MAGIC) { 1834 rtrs_err(clt, "Invalid RTRS magic\n"); 1835 return -ECONNRESET; 1836 } 1837 version = le16_to_cpu(msg->version); 1838 if (version >> 8 != RTRS_PROTO_VER_MAJOR) { 1839 rtrs_err(clt, "Unsupported major RTRS version: %d, expected %d\n", 1840 version >> 8, RTRS_PROTO_VER_MAJOR); 1841 return -ECONNRESET; 1842 } 1843 errno = le16_to_cpu(msg->errno); 1844 if (errno) { 1845 rtrs_err(clt, "Invalid RTRS message: errno %d\n", 1846 errno); 1847 return -ECONNRESET; 1848 } 1849 if (con->c.cid == 0) { 1850 queue_depth = le16_to_cpu(msg->queue_depth); 1851 1852 if (clt_path->queue_depth > 0 && queue_depth != clt_path->queue_depth) { 1853 rtrs_err(clt, "Error: queue depth changed\n"); 1854 1855 /* 1856 * Stop any more reconnection attempts 1857 */ 1858 clt_path->reconnect_attempts = -1; 1859 rtrs_err(clt, 1860 "Disabling auto-reconnect. Trigger a manual reconnect after issue is resolved\n"); 1861 return -ECONNRESET; 1862 } 1863 1864 if (!clt_path->rbufs) { 1865 clt_path->rbufs = kcalloc(queue_depth, 1866 sizeof(*clt_path->rbufs), 1867 GFP_KERNEL); 1868 if (!clt_path->rbufs) 1869 return -ENOMEM; 1870 } 1871 clt_path->queue_depth = queue_depth; 1872 clt_path->s.signal_interval = min_not_zero(queue_depth, 1873 (unsigned short) SERVICE_CON_QUEUE_DEPTH); 1874 clt_path->max_hdr_size = le32_to_cpu(msg->max_hdr_size); 1875 clt_path->max_io_size = le32_to_cpu(msg->max_io_size); 1876 clt_path->flags = le32_to_cpu(msg->flags); 1877 clt_path->chunk_size = clt_path->max_io_size + clt_path->max_hdr_size; 1878 1879 /* 1880 * Global IO size is always a minimum. 1881 * If while a reconnection server sends us a value a bit 1882 * higher - client does not care and uses cached minimum. 1883 * 1884 * Since we can have several sessions (paths) restablishing 1885 * connections in parallel, use lock. 1886 */ 1887 mutex_lock(&clt->paths_mutex); 1888 clt->queue_depth = clt_path->queue_depth; 1889 clt->max_io_size = min_not_zero(clt_path->max_io_size, 1890 clt->max_io_size); 1891 mutex_unlock(&clt->paths_mutex); 1892 1893 /* 1894 * Cache the hca_port and hca_name for sysfs 1895 */ 1896 clt_path->hca_port = con->c.cm_id->port_num; 1897 scnprintf(clt_path->hca_name, sizeof(clt_path->hca_name), 1898 clt_path->s.dev->ib_dev->name); 1899 clt_path->s.src_addr = con->c.cm_id->route.addr.src_addr; 1900 /* set for_new_clt, to allow future reconnect on any path */ 1901 clt_path->for_new_clt = 1; 1902 } 1903 1904 return 0; 1905 } 1906 1907 static inline void flag_success_on_conn(struct rtrs_clt_con *con) 1908 { 1909 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path); 1910 1911 atomic_inc(&clt_path->connected_cnt); 1912 con->cm_err = 1; 1913 } 1914 1915 static int rtrs_rdma_conn_rejected(struct rtrs_clt_con *con, 1916 struct rdma_cm_event *ev) 1917 { 1918 struct rtrs_path *s = con->c.path; 1919 const struct rtrs_msg_conn_rsp *msg; 1920 const char *rej_msg; 1921 int status, errno; 1922 u8 data_len; 1923 1924 status = ev->status; 1925 rej_msg = rdma_reject_msg(con->c.cm_id, status); 1926 msg = rdma_consumer_reject_data(con->c.cm_id, ev, &data_len); 1927 1928 if (msg && data_len >= sizeof(*msg)) { 1929 errno = (int16_t)le16_to_cpu(msg->errno); 1930 if (errno == -EBUSY) 1931 rtrs_err(s, 1932 "Previous session is still exists on the server, please reconnect later\n"); 1933 else 1934 rtrs_err(s, 1935 "Connect rejected: status %d (%s), rtrs errno %d\n", 1936 status, rej_msg, errno); 1937 } else { 1938 rtrs_err(s, 1939 "Connect rejected but with malformed message: status %d (%s)\n", 1940 status, rej_msg); 1941 } 1942 1943 return -ECONNRESET; 1944 } 1945 1946 void rtrs_clt_close_conns(struct rtrs_clt_path *clt_path, bool wait) 1947 { 1948 trace_rtrs_clt_close_conns(clt_path); 1949 1950 if (rtrs_clt_change_state_get_old(clt_path, RTRS_CLT_CLOSING, NULL)) 1951 queue_work(rtrs_wq, &clt_path->close_work); 1952 if (wait) 1953 flush_work(&clt_path->close_work); 1954 } 1955 1956 static inline void flag_error_on_conn(struct rtrs_clt_con *con, int cm_err) 1957 { 1958 if (con->cm_err == 1) { 1959 struct rtrs_clt_path *clt_path; 1960 1961 clt_path = to_clt_path(con->c.path); 1962 if (atomic_dec_and_test(&clt_path->connected_cnt)) 1963 1964 wake_up(&clt_path->state_wq); 1965 } 1966 con->cm_err = cm_err; 1967 } 1968 1969 static int rtrs_clt_rdma_cm_handler(struct rdma_cm_id *cm_id, 1970 struct rdma_cm_event *ev) 1971 { 1972 struct rtrs_clt_con *con = cm_id->context; 1973 struct rtrs_path *s = con->c.path; 1974 struct rtrs_clt_path *clt_path = to_clt_path(s); 1975 int cm_err = 0; 1976 1977 switch (ev->event) { 1978 case RDMA_CM_EVENT_ADDR_RESOLVED: 1979 cm_err = rtrs_rdma_addr_resolved(con); 1980 break; 1981 case RDMA_CM_EVENT_ROUTE_RESOLVED: 1982 cm_err = rtrs_rdma_route_resolved(con); 1983 break; 1984 case RDMA_CM_EVENT_ESTABLISHED: 1985 cm_err = rtrs_rdma_conn_established(con, ev); 1986 if (!cm_err) { 1987 /* 1988 * Report success and wake up. Here we abuse state_wq, 1989 * i.e. wake up without state change, but we set cm_err. 1990 */ 1991 flag_success_on_conn(con); 1992 wake_up(&clt_path->state_wq); 1993 return 0; 1994 } 1995 break; 1996 case RDMA_CM_EVENT_REJECTED: 1997 cm_err = rtrs_rdma_conn_rejected(con, ev); 1998 break; 1999 case RDMA_CM_EVENT_DISCONNECTED: 2000 /* No message for disconnecting */ 2001 cm_err = -ECONNRESET; 2002 break; 2003 case RDMA_CM_EVENT_CONNECT_ERROR: 2004 case RDMA_CM_EVENT_UNREACHABLE: 2005 case RDMA_CM_EVENT_ADDR_CHANGE: 2006 case RDMA_CM_EVENT_TIMEWAIT_EXIT: 2007 rtrs_wrn(s, "CM error (CM event: %s, err: %d)\n", 2008 rdma_event_msg(ev->event), ev->status); 2009 cm_err = -ECONNRESET; 2010 break; 2011 case RDMA_CM_EVENT_ADDR_ERROR: 2012 case RDMA_CM_EVENT_ROUTE_ERROR: 2013 rtrs_wrn(s, "CM error (CM event: %s, err: %d)\n", 2014 rdma_event_msg(ev->event), ev->status); 2015 cm_err = -EHOSTUNREACH; 2016 break; 2017 case RDMA_CM_EVENT_DEVICE_REMOVAL: 2018 /* 2019 * Device removal is a special case. Queue close and return 0. 2020 */ 2021 rtrs_clt_close_conns(clt_path, false); 2022 return 0; 2023 default: 2024 rtrs_err(s, "Unexpected RDMA CM error (CM event: %s, err: %d)\n", 2025 rdma_event_msg(ev->event), ev->status); 2026 cm_err = -ECONNRESET; 2027 break; 2028 } 2029 2030 if (cm_err) { 2031 /* 2032 * cm error makes sense only on connection establishing, 2033 * in other cases we rely on normal procedure of reconnecting. 2034 */ 2035 flag_error_on_conn(con, cm_err); 2036 rtrs_rdma_error_recovery(con); 2037 } 2038 2039 return 0; 2040 } 2041 2042 /* The caller should do the cleanup in case of error */ 2043 static int create_cm(struct rtrs_clt_con *con) 2044 { 2045 struct rtrs_path *s = con->c.path; 2046 struct rtrs_clt_path *clt_path = to_clt_path(s); 2047 struct rdma_cm_id *cm_id; 2048 int err; 2049 2050 cm_id = rdma_create_id(&init_net, rtrs_clt_rdma_cm_handler, con, 2051 clt_path->s.dst_addr.ss_family == AF_IB ? 2052 RDMA_PS_IB : RDMA_PS_TCP, IB_QPT_RC); 2053 if (IS_ERR(cm_id)) { 2054 err = PTR_ERR(cm_id); 2055 rtrs_err(s, "Failed to create CM ID, err: %d\n", err); 2056 2057 return err; 2058 } 2059 con->c.cm_id = cm_id; 2060 con->cm_err = 0; 2061 /* allow the port to be reused */ 2062 err = rdma_set_reuseaddr(cm_id, 1); 2063 if (err != 0) { 2064 rtrs_err(s, "Set address reuse failed, err: %d\n", err); 2065 return err; 2066 } 2067 err = rdma_resolve_addr(cm_id, (struct sockaddr *)&clt_path->s.src_addr, 2068 (struct sockaddr *)&clt_path->s.dst_addr, 2069 RTRS_CONNECT_TIMEOUT_MS); 2070 if (err) { 2071 rtrs_err(s, "Failed to resolve address, err: %d\n", err); 2072 return err; 2073 } 2074 /* 2075 * Combine connection status and session events. This is needed 2076 * for waiting two possible cases: cm_err has something meaningful 2077 * or session state was really changed to error by device removal. 2078 */ 2079 err = wait_event_interruptible_timeout( 2080 clt_path->state_wq, 2081 con->cm_err || clt_path->state != RTRS_CLT_CONNECTING, 2082 msecs_to_jiffies(RTRS_CONNECT_TIMEOUT_MS)); 2083 if (err == 0 || err == -ERESTARTSYS) { 2084 if (err == 0) 2085 err = -ETIMEDOUT; 2086 /* Timedout or interrupted */ 2087 return err; 2088 } 2089 if (con->cm_err < 0) 2090 return con->cm_err; 2091 if (READ_ONCE(clt_path->state) != RTRS_CLT_CONNECTING) 2092 /* Device removal */ 2093 return -ECONNABORTED; 2094 2095 return 0; 2096 } 2097 2098 static void rtrs_clt_path_up(struct rtrs_clt_path *clt_path) 2099 { 2100 struct rtrs_clt_sess *clt = clt_path->clt; 2101 int up; 2102 2103 /* 2104 * We can fire RECONNECTED event only when all paths were 2105 * connected on rtrs_clt_open(), then each was disconnected 2106 * and the first one connected again. That's why this nasty 2107 * game with counter value. 2108 */ 2109 2110 mutex_lock(&clt->paths_ev_mutex); 2111 up = ++clt->paths_up; 2112 /* 2113 * Here it is safe to access paths num directly since up counter 2114 * is greater than MAX_PATHS_NUM only while rtrs_clt_open() is 2115 * in progress, thus paths removals are impossible. 2116 */ 2117 if (up > MAX_PATHS_NUM && up == MAX_PATHS_NUM + clt->paths_num) 2118 clt->paths_up = clt->paths_num; 2119 else if (up == 1) 2120 clt->link_ev(clt->priv, RTRS_CLT_LINK_EV_RECONNECTED); 2121 mutex_unlock(&clt->paths_ev_mutex); 2122 2123 /* Mark session as established */ 2124 clt_path->established = true; 2125 clt_path->reconnect_attempts = 0; 2126 clt_path->stats->reconnects.successful_cnt++; 2127 } 2128 2129 static void rtrs_clt_path_down(struct rtrs_clt_path *clt_path) 2130 { 2131 struct rtrs_clt_sess *clt = clt_path->clt; 2132 2133 if (!clt_path->established) 2134 return; 2135 2136 clt_path->established = false; 2137 mutex_lock(&clt->paths_ev_mutex); 2138 WARN_ON(!clt->paths_up); 2139 if (--clt->paths_up == 0) 2140 clt->link_ev(clt->priv, RTRS_CLT_LINK_EV_DISCONNECTED); 2141 mutex_unlock(&clt->paths_ev_mutex); 2142 } 2143 2144 static void rtrs_clt_stop_and_destroy_conns(struct rtrs_clt_path *clt_path) 2145 { 2146 struct rtrs_clt_con *con; 2147 unsigned int cid; 2148 2149 WARN_ON(READ_ONCE(clt_path->state) == RTRS_CLT_CONNECTED); 2150 2151 /* 2152 * Possible race with rtrs_clt_open(), when DEVICE_REMOVAL comes 2153 * exactly in between. Start destroying after it finishes. 2154 */ 2155 mutex_lock(&clt_path->init_mutex); 2156 mutex_unlock(&clt_path->init_mutex); 2157 2158 /* 2159 * All IO paths must observe !CONNECTED state before we 2160 * free everything. 2161 */ 2162 synchronize_rcu(); 2163 2164 rtrs_stop_hb(&clt_path->s); 2165 2166 /* 2167 * The order it utterly crucial: firstly disconnect and complete all 2168 * rdma requests with error (thus set in_use=false for requests), 2169 * then fail outstanding requests checking in_use for each, and 2170 * eventually notify upper layer about session disconnection. 2171 */ 2172 2173 for (cid = 0; cid < clt_path->s.con_num; cid++) { 2174 if (!clt_path->s.con[cid]) 2175 break; 2176 con = to_clt_con(clt_path->s.con[cid]); 2177 stop_cm(con); 2178 } 2179 fail_all_outstanding_reqs(clt_path); 2180 free_path_reqs(clt_path); 2181 rtrs_clt_path_down(clt_path); 2182 2183 /* 2184 * Wait for graceful shutdown, namely when peer side invokes 2185 * rdma_disconnect(). 'connected_cnt' is decremented only on 2186 * CM events, thus if other side had crashed and hb has detected 2187 * something is wrong, here we will stuck for exactly timeout ms, 2188 * since CM does not fire anything. That is fine, we are not in 2189 * hurry. 2190 */ 2191 wait_event_timeout(clt_path->state_wq, 2192 !atomic_read(&clt_path->connected_cnt), 2193 msecs_to_jiffies(RTRS_CONNECT_TIMEOUT_MS)); 2194 2195 for (cid = 0; cid < clt_path->s.con_num; cid++) { 2196 if (!clt_path->s.con[cid]) 2197 break; 2198 con = to_clt_con(clt_path->s.con[cid]); 2199 mutex_lock(&con->con_mutex); 2200 destroy_con_cq_qp(con); 2201 mutex_unlock(&con->con_mutex); 2202 destroy_cm(con); 2203 destroy_con(con); 2204 } 2205 } 2206 2207 static void rtrs_clt_remove_path_from_arr(struct rtrs_clt_path *clt_path) 2208 { 2209 struct rtrs_clt_sess *clt = clt_path->clt; 2210 struct rtrs_clt_path *next; 2211 bool wait_for_grace = false; 2212 int cpu; 2213 2214 mutex_lock(&clt->paths_mutex); 2215 list_del_rcu(&clt_path->s.entry); 2216 2217 /* Make sure everybody observes path removal. */ 2218 synchronize_rcu(); 2219 2220 /* 2221 * At this point nobody sees @sess in the list, but still we have 2222 * dangling pointer @pcpu_path which _can_ point to @sess. Since 2223 * nobody can observe @sess in the list, we guarantee that IO path 2224 * will not assign @sess to @pcpu_path, i.e. @pcpu_path can be equal 2225 * to @sess, but can never again become @sess. 2226 */ 2227 2228 /* 2229 * Decrement paths number only after grace period, because 2230 * caller of do_each_path() must firstly observe list without 2231 * path and only then decremented paths number. 2232 * 2233 * Otherwise there can be the following situation: 2234 * o Two paths exist and IO is coming. 2235 * o One path is removed: 2236 * CPU#0 CPU#1 2237 * do_each_path(): rtrs_clt_remove_path_from_arr(): 2238 * path = get_next_path() 2239 * ^^^ list_del_rcu(path) 2240 * [!CONNECTED path] clt->paths_num-- 2241 * ^^^^^^^^^ 2242 * load clt->paths_num from 2 to 1 2243 * ^^^^^^^^^ 2244 * sees 1 2245 * 2246 * path is observed as !CONNECTED, but do_each_path() loop 2247 * ends, because expression i < clt->paths_num is false. 2248 */ 2249 clt->paths_num--; 2250 2251 /* 2252 * Get @next connection from current @sess which is going to be 2253 * removed. If @sess is the last element, then @next is NULL. 2254 */ 2255 rcu_read_lock(); 2256 next = rtrs_clt_get_next_path_or_null(&clt->paths_list, clt_path); 2257 rcu_read_unlock(); 2258 2259 /* 2260 * @pcpu paths can still point to the path which is going to be 2261 * removed, so change the pointer manually. 2262 */ 2263 for_each_possible_cpu(cpu) { 2264 struct rtrs_clt_path __rcu **ppcpu_path; 2265 2266 ppcpu_path = per_cpu_ptr(clt->pcpu_path, cpu); 2267 if (rcu_dereference_protected(*ppcpu_path, 2268 lockdep_is_held(&clt->paths_mutex)) != clt_path) 2269 /* 2270 * synchronize_rcu() was called just after deleting 2271 * entry from the list, thus IO code path cannot 2272 * change pointer back to the pointer which is going 2273 * to be removed, we are safe here. 2274 */ 2275 continue; 2276 2277 /* 2278 * We race with IO code path, which also changes pointer, 2279 * thus we have to be careful not to overwrite it. 2280 */ 2281 if (try_cmpxchg((struct rtrs_clt_path **)ppcpu_path, &clt_path, 2282 next)) 2283 /* 2284 * @ppcpu_path was successfully replaced with @next, 2285 * that means that someone could also pick up the 2286 * @sess and dereferencing it right now, so wait for 2287 * a grace period is required. 2288 */ 2289 wait_for_grace = true; 2290 } 2291 if (wait_for_grace) 2292 synchronize_rcu(); 2293 2294 mutex_unlock(&clt->paths_mutex); 2295 } 2296 2297 static void rtrs_clt_add_path_to_arr(struct rtrs_clt_path *clt_path) 2298 { 2299 struct rtrs_clt_sess *clt = clt_path->clt; 2300 2301 mutex_lock(&clt->paths_mutex); 2302 clt->paths_num++; 2303 2304 list_add_tail_rcu(&clt_path->s.entry, &clt->paths_list); 2305 mutex_unlock(&clt->paths_mutex); 2306 } 2307 2308 static void rtrs_clt_close_work(struct work_struct *work) 2309 { 2310 struct rtrs_clt_path *clt_path; 2311 2312 clt_path = container_of(work, struct rtrs_clt_path, close_work); 2313 2314 cancel_work_sync(&clt_path->err_recovery_work); 2315 cancel_delayed_work_sync(&clt_path->reconnect_dwork); 2316 rtrs_clt_stop_and_destroy_conns(clt_path); 2317 rtrs_clt_change_state_get_old(clt_path, RTRS_CLT_CLOSED, NULL); 2318 } 2319 2320 static int init_conns(struct rtrs_clt_path *clt_path) 2321 { 2322 unsigned int cid; 2323 int err, i; 2324 2325 /* 2326 * On every new session connections increase reconnect counter 2327 * to avoid clashes with previous sessions not yet closed 2328 * sessions on a server side. 2329 */ 2330 clt_path->s.recon_cnt++; 2331 2332 /* Establish all RDMA connections */ 2333 for (cid = 0; cid < clt_path->s.con_num; cid++) { 2334 err = create_con(clt_path, cid); 2335 if (err) 2336 goto destroy; 2337 2338 err = create_cm(to_clt_con(clt_path->s.con[cid])); 2339 if (err) 2340 goto destroy; 2341 } 2342 err = alloc_path_reqs(clt_path); 2343 if (err) 2344 goto destroy; 2345 2346 rtrs_start_hb(&clt_path->s); 2347 2348 return 0; 2349 2350 destroy: 2351 /* Make sure we do the cleanup in the order they are created */ 2352 for (i = 0; i <= cid; i++) { 2353 struct rtrs_clt_con *con; 2354 2355 if (!clt_path->s.con[i]) 2356 break; 2357 2358 con = to_clt_con(clt_path->s.con[i]); 2359 if (con->c.cm_id) { 2360 stop_cm(con); 2361 mutex_lock(&con->con_mutex); 2362 destroy_con_cq_qp(con); 2363 mutex_unlock(&con->con_mutex); 2364 destroy_cm(con); 2365 } 2366 destroy_con(con); 2367 } 2368 /* 2369 * If we've never taken async path and got an error, say, 2370 * doing rdma_resolve_addr(), switch to CONNECTION_ERR state 2371 * manually to keep reconnecting. 2372 */ 2373 rtrs_clt_change_state_get_old(clt_path, RTRS_CLT_CONNECTING_ERR, NULL); 2374 2375 return err; 2376 } 2377 2378 static void rtrs_clt_info_req_done(struct ib_cq *cq, struct ib_wc *wc) 2379 { 2380 struct rtrs_clt_con *con = to_clt_con(wc->qp->qp_context); 2381 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path); 2382 struct rtrs_iu *iu; 2383 2384 iu = container_of(wc->wr_cqe, struct rtrs_iu, cqe); 2385 rtrs_iu_free(iu, clt_path->s.dev->ib_dev, 1); 2386 2387 if (wc->status != IB_WC_SUCCESS) { 2388 rtrs_err(clt_path->clt, "Path info request send failed: %s\n", 2389 ib_wc_status_msg(wc->status)); 2390 rtrs_clt_change_state_get_old(clt_path, RTRS_CLT_CONNECTING_ERR, NULL); 2391 return; 2392 } 2393 2394 rtrs_clt_update_wc_stats(con); 2395 } 2396 2397 static int process_info_rsp(struct rtrs_clt_path *clt_path, 2398 const struct rtrs_msg_info_rsp *msg) 2399 { 2400 unsigned int sg_cnt, total_len; 2401 int i, sgi; 2402 2403 sg_cnt = le16_to_cpu(msg->sg_cnt); 2404 if (!sg_cnt || (clt_path->queue_depth % sg_cnt)) { 2405 rtrs_err(clt_path->clt, 2406 "Incorrect sg_cnt %d, is not multiple\n", 2407 sg_cnt); 2408 return -EINVAL; 2409 } 2410 2411 /* 2412 * Check if IB immediate data size is enough to hold the mem_id and 2413 * the offset inside the memory chunk. 2414 */ 2415 if ((ilog2(sg_cnt - 1) + 1) + (ilog2(clt_path->chunk_size - 1) + 1) > 2416 MAX_IMM_PAYL_BITS) { 2417 rtrs_err(clt_path->clt, 2418 "RDMA immediate size (%db) not enough to encode %d buffers of size %dB\n", 2419 MAX_IMM_PAYL_BITS, sg_cnt, clt_path->chunk_size); 2420 return -EINVAL; 2421 } 2422 total_len = 0; 2423 for (sgi = 0, i = 0; sgi < sg_cnt && i < clt_path->queue_depth; sgi++) { 2424 const struct rtrs_sg_desc *desc = &msg->desc[sgi]; 2425 u32 len, rkey; 2426 u64 addr; 2427 2428 addr = le64_to_cpu(desc->addr); 2429 rkey = le32_to_cpu(desc->key); 2430 len = le32_to_cpu(desc->len); 2431 2432 total_len += len; 2433 2434 if (!len || (len % clt_path->chunk_size)) { 2435 rtrs_err(clt_path->clt, "Incorrect [%d].len %d\n", 2436 sgi, 2437 len); 2438 return -EINVAL; 2439 } 2440 for ( ; len && i < clt_path->queue_depth; i++) { 2441 clt_path->rbufs[i].addr = addr; 2442 clt_path->rbufs[i].rkey = rkey; 2443 2444 len -= clt_path->chunk_size; 2445 addr += clt_path->chunk_size; 2446 } 2447 } 2448 /* Sanity check */ 2449 if (sgi != sg_cnt || i != clt_path->queue_depth) { 2450 rtrs_err(clt_path->clt, 2451 "Incorrect sg vector, not fully mapped\n"); 2452 return -EINVAL; 2453 } 2454 if (total_len != clt_path->chunk_size * clt_path->queue_depth) { 2455 rtrs_err(clt_path->clt, "Incorrect total_len %d\n", total_len); 2456 return -EINVAL; 2457 } 2458 2459 return 0; 2460 } 2461 2462 static void rtrs_clt_info_rsp_done(struct ib_cq *cq, struct ib_wc *wc) 2463 { 2464 struct rtrs_clt_con *con = to_clt_con(wc->qp->qp_context); 2465 struct rtrs_clt_path *clt_path = to_clt_path(con->c.path); 2466 struct rtrs_msg_info_rsp *msg; 2467 enum rtrs_clt_state state; 2468 struct rtrs_iu *iu; 2469 size_t rx_sz; 2470 int err; 2471 2472 state = RTRS_CLT_CONNECTING_ERR; 2473 2474 WARN_ON(con->c.cid); 2475 iu = container_of(wc->wr_cqe, struct rtrs_iu, cqe); 2476 if (wc->status != IB_WC_SUCCESS) { 2477 rtrs_err(clt_path->clt, "Path info response recv failed: %s\n", 2478 ib_wc_status_msg(wc->status)); 2479 goto out; 2480 } 2481 WARN_ON(wc->opcode != IB_WC_RECV); 2482 2483 if (wc->byte_len < sizeof(*msg)) { 2484 rtrs_err(clt_path->clt, "Path info response is malformed: size %d\n", 2485 wc->byte_len); 2486 goto out; 2487 } 2488 ib_dma_sync_single_for_cpu(clt_path->s.dev->ib_dev, iu->dma_addr, 2489 iu->size, DMA_FROM_DEVICE); 2490 msg = iu->buf; 2491 if (le16_to_cpu(msg->type) != RTRS_MSG_INFO_RSP) { 2492 rtrs_err(clt_path->clt, "Path info response is malformed: type %d\n", 2493 le16_to_cpu(msg->type)); 2494 goto out; 2495 } 2496 rx_sz = sizeof(*msg); 2497 rx_sz += sizeof(msg->desc[0]) * le16_to_cpu(msg->sg_cnt); 2498 if (wc->byte_len < rx_sz) { 2499 rtrs_err(clt_path->clt, "Path info response is malformed: size %d\n", 2500 wc->byte_len); 2501 goto out; 2502 } 2503 err = process_info_rsp(clt_path, msg); 2504 if (err) 2505 goto out; 2506 2507 err = post_recv_path(clt_path); 2508 if (err) 2509 goto out; 2510 2511 state = RTRS_CLT_CONNECTED; 2512 2513 out: 2514 rtrs_clt_update_wc_stats(con); 2515 rtrs_iu_free(iu, clt_path->s.dev->ib_dev, 1); 2516 rtrs_clt_change_state_get_old(clt_path, state, NULL); 2517 } 2518 2519 static int rtrs_send_path_info(struct rtrs_clt_path *clt_path) 2520 { 2521 struct rtrs_clt_con *usr_con = to_clt_con(clt_path->s.con[0]); 2522 struct rtrs_msg_info_req *msg; 2523 struct rtrs_iu *tx_iu, *rx_iu; 2524 size_t rx_sz; 2525 int err; 2526 2527 rx_sz = sizeof(struct rtrs_msg_info_rsp); 2528 rx_sz += sizeof(struct rtrs_sg_desc) * clt_path->queue_depth; 2529 2530 tx_iu = rtrs_iu_alloc(1, sizeof(struct rtrs_msg_info_req), GFP_KERNEL, 2531 clt_path->s.dev->ib_dev, DMA_TO_DEVICE, 2532 rtrs_clt_info_req_done); 2533 rx_iu = rtrs_iu_alloc(1, rx_sz, GFP_KERNEL, clt_path->s.dev->ib_dev, 2534 DMA_FROM_DEVICE, rtrs_clt_info_rsp_done); 2535 if (!tx_iu || !rx_iu) { 2536 err = -ENOMEM; 2537 goto out; 2538 } 2539 /* Prepare for getting info response */ 2540 err = rtrs_iu_post_recv(&usr_con->c, rx_iu); 2541 if (err) { 2542 rtrs_err(clt_path->clt, "rtrs_iu_post_recv(), err: %d\n", err); 2543 goto out; 2544 } 2545 rx_iu = NULL; 2546 2547 msg = tx_iu->buf; 2548 msg->type = cpu_to_le16(RTRS_MSG_INFO_REQ); 2549 memcpy(msg->pathname, clt_path->s.sessname, sizeof(msg->pathname)); 2550 2551 ib_dma_sync_single_for_device(clt_path->s.dev->ib_dev, 2552 tx_iu->dma_addr, 2553 tx_iu->size, DMA_TO_DEVICE); 2554 2555 /* Send info request */ 2556 err = rtrs_iu_post_send(&usr_con->c, tx_iu, sizeof(*msg), NULL); 2557 if (err) { 2558 rtrs_err(clt_path->clt, "rtrs_iu_post_send(), err: %d\n", err); 2559 goto out; 2560 } 2561 tx_iu = NULL; 2562 2563 /* Wait for state change */ 2564 wait_event_interruptible_timeout(clt_path->state_wq, 2565 clt_path->state != RTRS_CLT_CONNECTING, 2566 msecs_to_jiffies( 2567 RTRS_CONNECT_TIMEOUT_MS)); 2568 if (READ_ONCE(clt_path->state) != RTRS_CLT_CONNECTED) { 2569 if (READ_ONCE(clt_path->state) == RTRS_CLT_CONNECTING_ERR) 2570 err = -ECONNRESET; 2571 else 2572 err = -ETIMEDOUT; 2573 } 2574 2575 out: 2576 if (tx_iu) 2577 rtrs_iu_free(tx_iu, clt_path->s.dev->ib_dev, 1); 2578 if (rx_iu) 2579 rtrs_iu_free(rx_iu, clt_path->s.dev->ib_dev, 1); 2580 if (err) 2581 /* If we've never taken async path because of malloc problems */ 2582 rtrs_clt_change_state_get_old(clt_path, 2583 RTRS_CLT_CONNECTING_ERR, NULL); 2584 2585 return err; 2586 } 2587 2588 /** 2589 * init_path() - establishes all path connections and does handshake 2590 * @clt_path: client path. 2591 * In case of error full close or reconnect procedure should be taken, 2592 * because reconnect or close async works can be started. 2593 */ 2594 static int init_path(struct rtrs_clt_path *clt_path) 2595 { 2596 int err; 2597 char str[NAME_MAX]; 2598 struct rtrs_addr path = { 2599 .src = &clt_path->s.src_addr, 2600 .dst = &clt_path->s.dst_addr, 2601 }; 2602 2603 rtrs_addr_to_str(&path, str, sizeof(str)); 2604 2605 mutex_lock(&clt_path->init_mutex); 2606 err = init_conns(clt_path); 2607 if (err) { 2608 rtrs_err(clt_path->clt, 2609 "init_conns() failed: err=%d path=%s [%s:%u]\n", err, 2610 str, clt_path->hca_name, clt_path->hca_port); 2611 goto out; 2612 } 2613 err = rtrs_send_path_info(clt_path); 2614 if (err) { 2615 rtrs_err(clt_path->clt, 2616 "rtrs_send_path_info() failed: err=%d path=%s [%s:%u]\n", 2617 err, str, clt_path->hca_name, clt_path->hca_port); 2618 goto out; 2619 } 2620 rtrs_clt_path_up(clt_path); 2621 out: 2622 mutex_unlock(&clt_path->init_mutex); 2623 2624 return err; 2625 } 2626 2627 static void rtrs_clt_reconnect_work(struct work_struct *work) 2628 { 2629 struct rtrs_clt_path *clt_path; 2630 struct rtrs_clt_sess *clt; 2631 int err; 2632 2633 clt_path = container_of(to_delayed_work(work), struct rtrs_clt_path, 2634 reconnect_dwork); 2635 clt = clt_path->clt; 2636 2637 trace_rtrs_clt_reconnect_work(clt_path); 2638 2639 if (READ_ONCE(clt_path->state) != RTRS_CLT_RECONNECTING) 2640 return; 2641 2642 if (clt_path->reconnect_attempts >= clt->max_reconnect_attempts) { 2643 /* Close a path completely if max attempts is reached */ 2644 rtrs_clt_close_conns(clt_path, false); 2645 return; 2646 } 2647 clt_path->reconnect_attempts++; 2648 2649 msleep(RTRS_RECONNECT_BACKOFF); 2650 if (rtrs_clt_change_state_get_old(clt_path, RTRS_CLT_CONNECTING, NULL)) { 2651 err = init_path(clt_path); 2652 if (err) 2653 goto reconnect_again; 2654 } 2655 2656 return; 2657 2658 reconnect_again: 2659 if (rtrs_clt_change_state_get_old(clt_path, RTRS_CLT_RECONNECTING, NULL)) { 2660 clt_path->stats->reconnects.fail_cnt++; 2661 queue_work(rtrs_wq, &clt_path->err_recovery_work); 2662 } 2663 } 2664 2665 static void rtrs_clt_dev_release(struct device *dev) 2666 { 2667 struct rtrs_clt_sess *clt = container_of(dev, struct rtrs_clt_sess, 2668 dev); 2669 2670 mutex_destroy(&clt->paths_ev_mutex); 2671 mutex_destroy(&clt->paths_mutex); 2672 kfree(clt); 2673 } 2674 2675 static struct rtrs_clt_sess *alloc_clt(const char *sessname, size_t paths_num, 2676 u16 port, size_t pdu_sz, void *priv, 2677 void (*link_ev)(void *priv, 2678 enum rtrs_clt_link_ev ev), 2679 unsigned int reconnect_delay_sec, 2680 unsigned int max_reconnect_attempts) 2681 { 2682 struct rtrs_clt_sess *clt; 2683 int err; 2684 2685 if (!paths_num || paths_num > MAX_PATHS_NUM) 2686 return ERR_PTR(-EINVAL); 2687 2688 if (strlen(sessname) >= sizeof(clt->sessname)) 2689 return ERR_PTR(-EINVAL); 2690 2691 clt = kzalloc(sizeof(*clt), GFP_KERNEL); 2692 if (!clt) 2693 return ERR_PTR(-ENOMEM); 2694 2695 clt->pcpu_path = alloc_percpu(typeof(*clt->pcpu_path)); 2696 if (!clt->pcpu_path) { 2697 kfree(clt); 2698 return ERR_PTR(-ENOMEM); 2699 } 2700 2701 clt->dev.class = rtrs_clt_dev_class; 2702 clt->dev.release = rtrs_clt_dev_release; 2703 uuid_gen(&clt->paths_uuid); 2704 INIT_LIST_HEAD_RCU(&clt->paths_list); 2705 clt->paths_num = paths_num; 2706 clt->paths_up = MAX_PATHS_NUM; 2707 clt->port = port; 2708 clt->pdu_sz = pdu_sz; 2709 clt->max_segments = RTRS_MAX_SEGMENTS; 2710 clt->reconnect_delay_sec = reconnect_delay_sec; 2711 clt->max_reconnect_attempts = max_reconnect_attempts; 2712 clt->priv = priv; 2713 clt->link_ev = link_ev; 2714 clt->mp_policy = MP_POLICY_MIN_INFLIGHT; 2715 strscpy(clt->sessname, sessname, sizeof(clt->sessname)); 2716 init_waitqueue_head(&clt->permits_wait); 2717 mutex_init(&clt->paths_ev_mutex); 2718 mutex_init(&clt->paths_mutex); 2719 device_initialize(&clt->dev); 2720 2721 err = dev_set_name(&clt->dev, "%s", sessname); 2722 if (err) 2723 goto err_put; 2724 2725 /* 2726 * Suppress user space notification until 2727 * sysfs files are created 2728 */ 2729 dev_set_uevent_suppress(&clt->dev, true); 2730 err = device_add(&clt->dev); 2731 if (err) 2732 goto err_put; 2733 2734 clt->kobj_paths = kobject_create_and_add("paths", &clt->dev.kobj); 2735 if (!clt->kobj_paths) { 2736 err = -ENOMEM; 2737 goto err_del; 2738 } 2739 err = rtrs_clt_create_sysfs_root_files(clt); 2740 if (err) { 2741 kobject_del(clt->kobj_paths); 2742 kobject_put(clt->kobj_paths); 2743 goto err_del; 2744 } 2745 dev_set_uevent_suppress(&clt->dev, false); 2746 kobject_uevent(&clt->dev.kobj, KOBJ_ADD); 2747 2748 return clt; 2749 err_del: 2750 device_del(&clt->dev); 2751 err_put: 2752 free_percpu(clt->pcpu_path); 2753 put_device(&clt->dev); 2754 return ERR_PTR(err); 2755 } 2756 2757 static void free_clt(struct rtrs_clt_sess *clt) 2758 { 2759 free_percpu(clt->pcpu_path); 2760 2761 /* 2762 * release callback will free clt and destroy mutexes in last put 2763 */ 2764 device_unregister(&clt->dev); 2765 } 2766 2767 /** 2768 * rtrs_clt_open() - Open a path to an RTRS server 2769 * @ops: holds the link event callback and the private pointer. 2770 * @pathname: name of the path to an RTRS server 2771 * @paths: Paths to be established defined by their src and dst addresses 2772 * @paths_num: Number of elements in the @paths array 2773 * @port: port to be used by the RTRS session 2774 * @pdu_sz: Size of extra payload which can be accessed after permit allocation. 2775 * @reconnect_delay_sec: time between reconnect tries 2776 * @max_reconnect_attempts: Number of times to reconnect on error before giving 2777 * up, 0 for * disabled, -1 for forever 2778 * @nr_poll_queues: number of polling mode connection using IB_POLL_DIRECT flag 2779 * 2780 * Starts session establishment with the rtrs_server. The function can block 2781 * up to ~2000ms before it returns. 2782 * 2783 * Return a valid pointer on success otherwise PTR_ERR. 2784 */ 2785 struct rtrs_clt_sess *rtrs_clt_open(struct rtrs_clt_ops *ops, 2786 const char *pathname, 2787 const struct rtrs_addr *paths, 2788 size_t paths_num, u16 port, 2789 size_t pdu_sz, u8 reconnect_delay_sec, 2790 s16 max_reconnect_attempts, u32 nr_poll_queues) 2791 { 2792 struct rtrs_clt_path *clt_path, *tmp; 2793 struct rtrs_clt_sess *clt; 2794 int err, i; 2795 2796 if (strchr(pathname, '/') || strchr(pathname, '.')) { 2797 pr_err("pathname cannot contain / and .\n"); 2798 err = -EINVAL; 2799 goto out; 2800 } 2801 2802 clt = alloc_clt(pathname, paths_num, port, pdu_sz, ops->priv, 2803 ops->link_ev, 2804 reconnect_delay_sec, 2805 max_reconnect_attempts); 2806 if (IS_ERR(clt)) { 2807 err = PTR_ERR(clt); 2808 goto out; 2809 } 2810 for (i = 0; i < paths_num; i++) { 2811 struct rtrs_clt_path *clt_path; 2812 2813 clt_path = alloc_path(clt, &paths[i], nr_cpu_ids, 2814 nr_poll_queues); 2815 if (IS_ERR(clt_path)) { 2816 err = PTR_ERR(clt_path); 2817 goto close_all_path; 2818 } 2819 if (!i) 2820 clt_path->for_new_clt = 1; 2821 list_add_tail_rcu(&clt_path->s.entry, &clt->paths_list); 2822 2823 err = init_path(clt_path); 2824 if (err) { 2825 list_del_rcu(&clt_path->s.entry); 2826 rtrs_clt_close_conns(clt_path, true); 2827 free_percpu(clt_path->stats->pcpu_stats); 2828 kfree(clt_path->stats); 2829 free_path(clt_path); 2830 goto close_all_path; 2831 } 2832 2833 err = rtrs_clt_create_path_files(clt_path); 2834 if (err) { 2835 list_del_rcu(&clt_path->s.entry); 2836 rtrs_clt_close_conns(clt_path, true); 2837 free_percpu(clt_path->stats->pcpu_stats); 2838 kfree(clt_path->stats); 2839 free_path(clt_path); 2840 goto close_all_path; 2841 } 2842 } 2843 err = alloc_permits(clt); 2844 if (err) 2845 goto close_all_path; 2846 2847 return clt; 2848 2849 close_all_path: 2850 list_for_each_entry_safe(clt_path, tmp, &clt->paths_list, s.entry) { 2851 rtrs_clt_destroy_path_files(clt_path, NULL); 2852 rtrs_clt_close_conns(clt_path, true); 2853 kobject_put(&clt_path->kobj); 2854 } 2855 rtrs_clt_destroy_sysfs_root(clt); 2856 free_clt(clt); 2857 2858 out: 2859 return ERR_PTR(err); 2860 } 2861 EXPORT_SYMBOL(rtrs_clt_open); 2862 2863 /** 2864 * rtrs_clt_close() - Close a path 2865 * @clt: Session handle. Session is freed upon return. 2866 */ 2867 void rtrs_clt_close(struct rtrs_clt_sess *clt) 2868 { 2869 struct rtrs_clt_path *clt_path, *tmp; 2870 2871 /* Firstly forbid sysfs access */ 2872 rtrs_clt_destroy_sysfs_root(clt); 2873 2874 /* Now it is safe to iterate over all paths without locks */ 2875 list_for_each_entry_safe(clt_path, tmp, &clt->paths_list, s.entry) { 2876 rtrs_clt_close_conns(clt_path, true); 2877 rtrs_clt_destroy_path_files(clt_path, NULL); 2878 kobject_put(&clt_path->kobj); 2879 } 2880 free_permits(clt); 2881 free_clt(clt); 2882 } 2883 EXPORT_SYMBOL(rtrs_clt_close); 2884 2885 int rtrs_clt_reconnect_from_sysfs(struct rtrs_clt_path *clt_path) 2886 { 2887 enum rtrs_clt_state old_state; 2888 int err = -EBUSY; 2889 bool changed; 2890 2891 changed = rtrs_clt_change_state_get_old(clt_path, 2892 RTRS_CLT_RECONNECTING, 2893 &old_state); 2894 if (changed) { 2895 clt_path->reconnect_attempts = 0; 2896 rtrs_clt_stop_and_destroy_conns(clt_path); 2897 queue_delayed_work(rtrs_wq, &clt_path->reconnect_dwork, 0); 2898 } 2899 if (changed || old_state == RTRS_CLT_RECONNECTING) { 2900 /* 2901 * flush_delayed_work() queues pending work for immediate 2902 * execution, so do the flush if we have queued something 2903 * right now or work is pending. 2904 */ 2905 flush_delayed_work(&clt_path->reconnect_dwork); 2906 err = (READ_ONCE(clt_path->state) == 2907 RTRS_CLT_CONNECTED ? 0 : -ENOTCONN); 2908 } 2909 2910 return err; 2911 } 2912 2913 int rtrs_clt_remove_path_from_sysfs(struct rtrs_clt_path *clt_path, 2914 const struct attribute *sysfs_self) 2915 { 2916 enum rtrs_clt_state old_state; 2917 bool changed; 2918 2919 /* 2920 * Continue stopping path till state was changed to DEAD or 2921 * state was observed as DEAD: 2922 * 1. State was changed to DEAD - we were fast and nobody 2923 * invoked rtrs_clt_reconnect(), which can again start 2924 * reconnecting. 2925 * 2. State was observed as DEAD - we have someone in parallel 2926 * removing the path. 2927 */ 2928 do { 2929 rtrs_clt_close_conns(clt_path, true); 2930 changed = rtrs_clt_change_state_get_old(clt_path, 2931 RTRS_CLT_DEAD, 2932 &old_state); 2933 } while (!changed && old_state != RTRS_CLT_DEAD); 2934 2935 if (changed) { 2936 rtrs_clt_remove_path_from_arr(clt_path); 2937 rtrs_clt_destroy_path_files(clt_path, sysfs_self); 2938 kobject_put(&clt_path->kobj); 2939 } 2940 2941 return 0; 2942 } 2943 2944 void rtrs_clt_set_max_reconnect_attempts(struct rtrs_clt_sess *clt, int value) 2945 { 2946 clt->max_reconnect_attempts = (unsigned int)value; 2947 } 2948 2949 int rtrs_clt_get_max_reconnect_attempts(const struct rtrs_clt_sess *clt) 2950 { 2951 return (int)clt->max_reconnect_attempts; 2952 } 2953 2954 /** 2955 * rtrs_clt_request() - Request data transfer to/from server via RDMA. 2956 * 2957 * @dir: READ/WRITE 2958 * @ops: callback function to be called as confirmation, and the pointer. 2959 * @clt: Session 2960 * @permit: Preallocated permit 2961 * @vec: Message that is sent to server together with the request. 2962 * Sum of len of all @vec elements limited to <= IO_MSG_SIZE. 2963 * Since the msg is copied internally it can be allocated on stack. 2964 * @nr: Number of elements in @vec. 2965 * @data_len: length of data sent to/from server 2966 * @sg: Pages to be sent/received to/from server. 2967 * @sg_cnt: Number of elements in the @sg 2968 * 2969 * Return: 2970 * 0: Success 2971 * <0: Error 2972 * 2973 * On dir=READ rtrs client will request a data transfer from Server to client. 2974 * The data that the server will respond with will be stored in @sg when 2975 * the user receives an %RTRS_CLT_RDMA_EV_RDMA_REQUEST_WRITE_COMPL event. 2976 * On dir=WRITE rtrs client will rdma write data in sg to server side. 2977 */ 2978 int rtrs_clt_request(int dir, struct rtrs_clt_req_ops *ops, 2979 struct rtrs_clt_sess *clt, struct rtrs_permit *permit, 2980 const struct kvec *vec, size_t nr, size_t data_len, 2981 struct scatterlist *sg, unsigned int sg_cnt) 2982 { 2983 struct rtrs_clt_io_req *req; 2984 struct rtrs_clt_path *clt_path; 2985 2986 enum dma_data_direction dma_dir; 2987 int err = -ECONNABORTED, i; 2988 size_t usr_len, hdr_len; 2989 struct path_it it; 2990 2991 /* Get kvec length */ 2992 for (i = 0, usr_len = 0; i < nr; i++) 2993 usr_len += vec[i].iov_len; 2994 2995 if (dir == READ) { 2996 hdr_len = sizeof(struct rtrs_msg_rdma_read) + 2997 sg_cnt * sizeof(struct rtrs_sg_desc); 2998 dma_dir = DMA_FROM_DEVICE; 2999 } else { 3000 hdr_len = sizeof(struct rtrs_msg_rdma_write); 3001 dma_dir = DMA_TO_DEVICE; 3002 } 3003 3004 rcu_read_lock(); 3005 for (path_it_init(&it, clt); 3006 (clt_path = it.next_path(&it)) && it.i < it.clt->paths_num; it.i++) { 3007 if (READ_ONCE(clt_path->state) != RTRS_CLT_CONNECTED) 3008 continue; 3009 3010 if (usr_len + hdr_len > clt_path->max_hdr_size) { 3011 rtrs_wrn_rl(clt_path->clt, 3012 "%s request failed, user message size is %zu and header length %zu, but max size is %u\n", 3013 dir == READ ? "Read" : "Write", 3014 usr_len, hdr_len, clt_path->max_hdr_size); 3015 err = -EMSGSIZE; 3016 break; 3017 } 3018 req = rtrs_clt_get_req(clt_path, ops->conf_fn, permit, ops->priv, 3019 vec, usr_len, sg, sg_cnt, data_len, 3020 dma_dir); 3021 if (dir == READ) 3022 err = rtrs_clt_read_req(req); 3023 else 3024 err = rtrs_clt_write_req(req); 3025 if (err) { 3026 req->in_use = false; 3027 continue; 3028 } 3029 /* Success path */ 3030 break; 3031 } 3032 path_it_deinit(&it); 3033 rcu_read_unlock(); 3034 3035 return err; 3036 } 3037 EXPORT_SYMBOL(rtrs_clt_request); 3038 3039 int rtrs_clt_rdma_cq_direct(struct rtrs_clt_sess *clt, unsigned int index) 3040 { 3041 /* If no path, return -1 for block layer not to try again */ 3042 int cnt = -1; 3043 struct rtrs_con *con; 3044 struct rtrs_clt_path *clt_path; 3045 struct path_it it; 3046 3047 rcu_read_lock(); 3048 for (path_it_init(&it, clt); 3049 (clt_path = it.next_path(&it)) && it.i < it.clt->paths_num; it.i++) { 3050 if (READ_ONCE(clt_path->state) != RTRS_CLT_CONNECTED) 3051 continue; 3052 3053 con = clt_path->s.con[index + 1]; 3054 cnt = ib_process_cq_direct(con->cq, -1); 3055 if (cnt) 3056 break; 3057 } 3058 path_it_deinit(&it); 3059 rcu_read_unlock(); 3060 3061 return cnt; 3062 } 3063 EXPORT_SYMBOL(rtrs_clt_rdma_cq_direct); 3064 3065 /** 3066 * rtrs_clt_query() - queries RTRS session attributes 3067 *@clt: session pointer 3068 *@attr: query results for session attributes. 3069 * Returns: 3070 * 0 on success 3071 * -ECOMM no connection to the server 3072 */ 3073 int rtrs_clt_query(struct rtrs_clt_sess *clt, struct rtrs_attrs *attr) 3074 { 3075 if (!rtrs_clt_is_connected(clt)) 3076 return -ECOMM; 3077 3078 attr->queue_depth = clt->queue_depth; 3079 attr->max_segments = clt->max_segments; 3080 /* Cap max_io_size to min of remote buffer size and the fr pages */ 3081 attr->max_io_size = min_t(int, clt->max_io_size, 3082 clt->max_segments * SZ_4K); 3083 3084 return 0; 3085 } 3086 EXPORT_SYMBOL(rtrs_clt_query); 3087 3088 int rtrs_clt_create_path_from_sysfs(struct rtrs_clt_sess *clt, 3089 struct rtrs_addr *addr) 3090 { 3091 struct rtrs_clt_path *clt_path; 3092 int err; 3093 3094 clt_path = alloc_path(clt, addr, nr_cpu_ids, 0); 3095 if (IS_ERR(clt_path)) 3096 return PTR_ERR(clt_path); 3097 3098 mutex_lock(&clt->paths_mutex); 3099 if (clt->paths_num == 0) { 3100 /* 3101 * When all the paths are removed for a session, 3102 * the addition of the first path is like a new session for 3103 * the storage server 3104 */ 3105 clt_path->for_new_clt = 1; 3106 } 3107 3108 mutex_unlock(&clt->paths_mutex); 3109 3110 /* 3111 * It is totally safe to add path in CONNECTING state: coming 3112 * IO will never grab it. Also it is very important to add 3113 * path before init, since init fires LINK_CONNECTED event. 3114 */ 3115 rtrs_clt_add_path_to_arr(clt_path); 3116 3117 err = init_path(clt_path); 3118 if (err) 3119 goto close_path; 3120 3121 err = rtrs_clt_create_path_files(clt_path); 3122 if (err) 3123 goto close_path; 3124 3125 return 0; 3126 3127 close_path: 3128 rtrs_clt_remove_path_from_arr(clt_path); 3129 rtrs_clt_close_conns(clt_path, true); 3130 free_percpu(clt_path->stats->pcpu_stats); 3131 kfree(clt_path->stats); 3132 free_path(clt_path); 3133 3134 return err; 3135 } 3136 3137 static int rtrs_clt_ib_dev_init(struct rtrs_ib_dev *dev) 3138 { 3139 if (!(dev->ib_dev->attrs.device_cap_flags & 3140 IB_DEVICE_MEM_MGT_EXTENSIONS)) { 3141 pr_err("Memory registrations not supported.\n"); 3142 return -ENOTSUPP; 3143 } 3144 3145 return 0; 3146 } 3147 3148 static const struct rtrs_rdma_dev_pd_ops dev_pd_ops = { 3149 .init = rtrs_clt_ib_dev_init 3150 }; 3151 3152 static int __init rtrs_client_init(void) 3153 { 3154 rtrs_rdma_dev_pd_init(0, &dev_pd); 3155 3156 rtrs_clt_dev_class = class_create("rtrs-client"); 3157 if (IS_ERR(rtrs_clt_dev_class)) { 3158 pr_err("Failed to create rtrs-client dev class\n"); 3159 return PTR_ERR(rtrs_clt_dev_class); 3160 } 3161 rtrs_wq = alloc_workqueue("rtrs_client_wq", 0, 0); 3162 if (!rtrs_wq) { 3163 class_destroy(rtrs_clt_dev_class); 3164 return -ENOMEM; 3165 } 3166 3167 return 0; 3168 } 3169 3170 static void __exit rtrs_client_exit(void) 3171 { 3172 destroy_workqueue(rtrs_wq); 3173 class_destroy(rtrs_clt_dev_class); 3174 rtrs_rdma_dev_pd_deinit(&dev_pd); 3175 } 3176 3177 module_init(rtrs_client_init); 3178 module_exit(rtrs_client_exit); 3179