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