lnet/klnds/kfilnd/kfilnd_tn.c

   1 /*
   2  * GPL HEADER START
   3  *
   4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 only,
   8  * as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * General Public License version 2 for more details (a copy is included
  14  * in the LICENSE file that accompanied this code).
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * version 2 along with this program; If not, see
  18  * http://www.gnu.org/licenses/gpl-2.0.html
  19  *
  20  * GPL HEADER END
  21  */
  22 /*
  23  * Copyright 2022 Hewlett Packard Enterprise Development LP
  24  */
  25 /*
  26  * This file is part of Lustre, http://www.lustre.org/
  27  */
  28 /*
  29  * kfilnd transaction and state machine processing.
  30  */
  31
  32 #include "kfilnd_tn.h"
  33 #include "kfilnd_ep.h"
  34 #include "kfilnd_dev.h"
  35 #include "kfilnd_dom.h"
  36 #include "kfilnd_peer.h"
  37 #include <asm/checksum.h>
  38
  39 static struct kmem_cache *tn_cache;
  40 static struct kmem_cache *imm_buf_cache;
  41
  42 static __sum16 kfilnd_tn_cksum(void *ptr, int nob)
  43 {
  44         if (cksum)
  45                 return csum_fold(csum_partial(ptr, nob, 0));
  46         return NO_CHECKSUM;
  47 }
  48
  49 static int kfilnd_tn_msgtype2size(enum kfilnd_msg_type type)
  50 {
  51         const int hdr_size = offsetof(struct kfilnd_msg, proto);
  52
  53         switch (type) {
  54         case KFILND_MSG_IMMEDIATE:
  55                 return offsetof(struct kfilnd_msg, proto.immed.payload[0]);
  56
  57         case KFILND_MSG_BULK_PUT_REQ:
  58         case KFILND_MSG_BULK_GET_REQ:
  59                 return hdr_size + sizeof(struct kfilnd_bulk_req_msg);
  60
  61         default:
  62                 return -1;
  63         }
  64 }
  65
  66 static void kfilnd_tn_pack_hello_req(struct kfilnd_transaction *tn)
  67 {
  68         struct kfilnd_msg *msg = tn->tn_tx_msg.msg;
  69
  70         /* Pack the protocol header and payload. */
  71         msg->proto.hello.version = KFILND_MSG_VERSION;
  72         msg->proto.hello.rx_base = kfilnd_peer_target_rx_base(tn->peer);
  73         msg->proto.hello.session_key = tn->peer->local_session_key;
  74
  75         /* TODO: Support multiple RX contexts per peer. */
  76         msg->proto.hello.rx_count = 1;
  77
  78         /* Pack the transport header. */
  79         msg->magic = KFILND_MSG_MAGIC;
  80
  81         /* Mesage version zero is only valid for hello requests. */
  82         msg->version = 0;
  83         msg->type = KFILND_MSG_HELLO_REQ;
  84         msg->nob = sizeof(struct kfilnd_hello_msg) +
  85                 offsetof(struct kfilnd_msg, proto);
  86         msg->cksum = NO_CHECKSUM;
  87         msg->srcnid = lnet_nid_to_nid4(&tn->tn_ep->end_dev->kfd_ni->ni_nid);
  88         msg->dstnid = tn->peer->nid;
  89
  90         /* Checksum entire message. */
  91         msg->cksum = kfilnd_tn_cksum(msg, msg->nob);
  92
  93         tn->tn_tx_msg.length = msg->nob;
  94 }
  95
  96 static void kfilnd_tn_pack_hello_rsp(struct kfilnd_transaction *tn)
  97 {
  98         struct kfilnd_msg *msg = tn->tn_tx_msg.msg;
  99
 100         /* Pack the protocol header and payload. */
 101         msg->proto.hello.version = tn->peer->version;
 102         msg->proto.hello.rx_base = kfilnd_peer_target_rx_base(tn->peer);
 103         msg->proto.hello.session_key = tn->peer->local_session_key;
 104
 105         /* TODO: Support multiple RX contexts per peer. */
 106         msg->proto.hello.rx_count = 1;
 107
 108         /* Pack the transport header. */
 109         msg->magic = KFILND_MSG_MAGIC;
 110
 111         /* Mesage version zero is only valid for hello requests. */
 112         msg->version = 0;
 113         msg->type = KFILND_MSG_HELLO_RSP;
 114         msg->nob = sizeof(struct kfilnd_hello_msg) +
 115                 offsetof(struct kfilnd_msg, proto);
 116         msg->cksum = NO_CHECKSUM;
 117         msg->srcnid = lnet_nid_to_nid4(&tn->tn_ep->end_dev->kfd_ni->ni_nid);
 118         msg->dstnid = tn->peer->nid;
 119
 120         /* Checksum entire message. */
 121         msg->cksum = kfilnd_tn_cksum(msg, msg->nob);
 122
 123         tn->tn_tx_msg.length = msg->nob;
 124 }
 125
 126 static void kfilnd_tn_pack_bulk_req(struct kfilnd_transaction *tn)
 127 {
 128         struct kfilnd_msg *msg = tn->tn_tx_msg.msg;
 129
 130         /* Pack the protocol header and payload. */
 131         lnet_hdr_to_nid4(&tn->tn_lntmsg->msg_hdr, &msg->proto.bulk_req.hdr);
 132         msg->proto.bulk_req.key = tn->tn_mr_key;
 133         msg->proto.bulk_req.response_rx = tn->tn_response_rx;
 134
 135         /* Pack the transport header. */
 136         msg->magic = KFILND_MSG_MAGIC;
 137         msg->version = KFILND_MSG_VERSION;
 138         msg->type = tn->msg_type;
 139         msg->nob = sizeof(struct kfilnd_bulk_req_msg) +
 140                 offsetof(struct kfilnd_msg, proto);
 141         msg->cksum = NO_CHECKSUM;
 142         msg->srcnid = lnet_nid_to_nid4(&tn->tn_ep->end_dev->kfd_ni->ni_nid);
 143         msg->dstnid = tn->peer->nid;
 144
 145         /* Checksum entire message. */
 146         msg->cksum = kfilnd_tn_cksum(msg, msg->nob);
 147
 148         tn->tn_tx_msg.length = msg->nob;
 149 }
 150
 151 static void kfilnd_tn_pack_immed_msg(struct kfilnd_transaction *tn)
 152 {
 153         struct kfilnd_msg *msg = tn->tn_tx_msg.msg;
 154
 155         /* Pack the protocol header and payload. */
 156         lnet_hdr_to_nid4(&tn->tn_lntmsg->msg_hdr, &msg->proto.immed.hdr);
 157
 158         lnet_copy_kiov2flat(KFILND_IMMEDIATE_MSG_SIZE,
 159                             msg,
 160                             offsetof(struct kfilnd_msg,
 161                                      proto.immed.payload),
 162                             tn->tn_num_iovec, tn->tn_kiov, 0,
 163                             tn->tn_nob);
 164
 165         /* Pack the transport header. */
 166         msg->magic = KFILND_MSG_MAGIC;
 167         msg->version = KFILND_MSG_VERSION;
 168         msg->type = tn->msg_type;
 169         msg->nob = offsetof(struct kfilnd_msg, proto.immed.payload[tn->tn_nob]);
 170         msg->cksum = NO_CHECKSUM;
 171         msg->srcnid = lnet_nid_to_nid4(&tn->tn_ep->end_dev->kfd_ni->ni_nid);
 172         msg->dstnid = tn->peer->nid;
 173
 174         /* Checksum entire message. */
 175         msg->cksum = kfilnd_tn_cksum(msg, msg->nob);
 176
 177         tn->tn_tx_msg.length = msg->nob;
 178 }
 179
 180 static int kfilnd_tn_unpack_msg(struct kfilnd_ep *ep, struct kfilnd_msg *msg,
 181                                 unsigned int nob)
 182 {
 183         const unsigned int hdr_size = offsetof(struct kfilnd_msg, proto);
 184
 185         if (nob < hdr_size) {
 186                 KFILND_EP_ERROR(ep, "Short message: %u", nob);
 187                 return -EPROTO;
 188         }
 189
 190         /* TODO: Support byte swapping on mixed endian systems. */
 191         if (msg->magic != KFILND_MSG_MAGIC) {
 192                 KFILND_EP_ERROR(ep, "Bad magic: %#x", msg->magic);
 193                 return -EPROTO;
 194         }
 195
 196         /* TODO: Allow for older versions. */
 197         if (msg->version > KFILND_MSG_VERSION) {
 198                 KFILND_EP_ERROR(ep, "Bad version: %#x", msg->version);
 199                 return -EPROTO;
 200         }
 201
 202         if (msg->nob > nob) {
 203                 KFILND_EP_ERROR(ep, "Short message: got=%u, expected=%u", nob,
 204                                 msg->nob);
 205                 return -EPROTO;
 206         }
 207
 208         /* If kfilnd_tn_cksum() returns a non-zero value, checksum is bad. */
 209         if (msg->cksum != NO_CHECKSUM && kfilnd_tn_cksum(msg, msg->nob)) {
 210                 KFILND_EP_ERROR(ep, "Bad checksum");
 211                 return -EPROTO;
 212         }
 213
 214         if (msg->dstnid != lnet_nid_to_nid4(&ep->end_dev->kfd_ni->ni_nid)) {
 215                 KFILND_EP_ERROR(ep, "Bad destination nid: %s",
 216                                 libcfs_nid2str(msg->dstnid));
 217                 return -EPROTO;
 218         }
 219
 220         if (msg->srcnid == LNET_NID_ANY) {
 221                 KFILND_EP_ERROR(ep, "Bad source nid: %s",
 222                                 libcfs_nid2str(msg->srcnid));
 223                 return -EPROTO;
 224         }
 225
 226         if (msg->nob < kfilnd_tn_msgtype2size(msg->type)) {
 227                 KFILND_EP_ERROR(ep, "Short %s: %d(%d)\n",
 228                                 msg_type_to_str(msg->type),
 229                                 msg->nob, kfilnd_tn_msgtype2size(msg->type));
 230                 return -EPROTO;
 231         }
 232
 233         switch ((enum kfilnd_msg_type)msg->type) {
 234         case KFILND_MSG_IMMEDIATE:
 235         case KFILND_MSG_BULK_PUT_REQ:
 236         case KFILND_MSG_BULK_GET_REQ:
 237                 if (msg->version == 0) {
 238                         KFILND_EP_ERROR(ep,
 239                                         "Bad message type and version: type=%s version=%u",
 240                                         msg_type_to_str(msg->type),
 241                                         msg->version);
 242                         return -EPROTO;
 243                 }
 244                 break;
 245
 246         case KFILND_MSG_HELLO_REQ:
 247         case KFILND_MSG_HELLO_RSP:
 248                 if (msg->version != 0) {
 249                         KFILND_EP_ERROR(ep,
 250                                         "Bad message type and version: type=%s version=%u",
 251                                         msg_type_to_str(msg->type),
 252                                         msg->version);
 253                         return -EPROTO;
 254                 }
 255                 break;
 256
 257         default:
 258                 CERROR("Unknown message type %x\n", msg->type);
 259                 return -EPROTO;
 260         }
 261         return 0;
 262 }
 263
 264 static void kfilnd_tn_record_state_change(struct kfilnd_transaction *tn)
 265 {
 266         unsigned int data_size_bucket =
 267                 kfilnd_msg_len_to_data_size_bucket(tn->lnet_msg_len);
 268         struct kfilnd_tn_duration_stat *stat;
 269
 270         if (tn->is_initiator)
 271                 stat = &tn->tn_ep->end_dev->initiator_state_stats.state[tn->tn_state].data_size[data_size_bucket];
 272         else
 273                 stat = &tn->tn_ep->end_dev->target_state_stats.state[tn->tn_state].data_size[data_size_bucket];
 274
 275         atomic64_add(ktime_to_ns(ktime_sub(ktime_get(), tn->tn_state_ts)),
 276                      &stat->accumulated_duration);
 277         atomic_inc(&stat->accumulated_count);
 278 }
 279
 280 static void kfilnd_tn_state_change(struct kfilnd_transaction *tn,
 281                                    enum tn_states new_state)
 282 {
 283         KFILND_TN_DEBUG(tn, "%s -> %s state change",
 284                         tn_state_to_str(tn->tn_state),
 285                         tn_state_to_str(new_state));
 286
 287         kfilnd_tn_record_state_change(tn);
 288
 289         tn->tn_state = new_state;
 290         tn->tn_state_ts = ktime_get();
 291 }
 292
 293 static void kfilnd_tn_status_update(struct kfilnd_transaction *tn, int status,
 294                                     enum lnet_msg_hstatus hstatus)
 295 {
 296         /* Only the first non-ok status will take. */
 297         if (tn->tn_status == 0) {
 298                 KFILND_TN_DEBUG(tn, "%d -> %d status change", tn->tn_status,
 299                                 status);
 300                 tn->tn_status = status;
 301         }
 302
 303         if (tn->hstatus == LNET_MSG_STATUS_OK) {
 304                 KFILND_TN_DEBUG(tn, "%d -> %d health status change",
 305                                 tn->hstatus, hstatus);
 306                 tn->hstatus = hstatus;
 307         }
 308 }
 309
 310 static bool kfilnd_tn_has_failed(struct kfilnd_transaction *tn)
 311 {
 312         return tn->tn_status != 0;
 313 }
 314
 315 /**
 316  * kfilnd_tn_process_rx_event() - Process an immediate receive event.
 317  *
 318  * For each immediate receive, a transaction structure needs to be allocated to
 319  * process the receive.
 320  */
 321 void kfilnd_tn_process_rx_event(struct kfilnd_immediate_buffer *bufdesc,
 322                                 struct kfilnd_msg *rx_msg, int msg_size)
 323 {
 324         struct kfilnd_transaction *tn;
 325         bool alloc_msg = true;
 326         int rc;
 327         enum tn_events event = TN_EVENT_RX_HELLO;
 328
 329         /* Increment buf ref count for this work */
 330         atomic_inc(&bufdesc->immed_ref);
 331
 332         /* Unpack the message */
 333         rc = kfilnd_tn_unpack_msg(bufdesc->immed_end, rx_msg, msg_size);
 334         if (rc || CFS_FAIL_CHECK(CFS_KFI_FAIL_MSG_UNPACK)) {
 335                 kfilnd_ep_imm_buffer_put(bufdesc);
 336                 KFILND_EP_ERROR(bufdesc->immed_end,
 337                                 "Failed to unpack message %d", rc);
 338                 return;
 339         }
 340
 341         switch ((enum kfilnd_msg_type)rx_msg->type) {
 342         case KFILND_MSG_IMMEDIATE:
 343         case KFILND_MSG_BULK_PUT_REQ:
 344         case KFILND_MSG_BULK_GET_REQ:
 345                 event = TN_EVENT_RX_OK;
 346                 fallthrough;
 347         case KFILND_MSG_HELLO_RSP:
 348                 alloc_msg = false;
 349                 fallthrough;
 350         case KFILND_MSG_HELLO_REQ:
 351                 /* Context points to a received buffer and status is the length.
 352                  * Allocate a Tn structure, set its values, then launch the
 353                  * receive.
 354                  */
 355                 tn = kfilnd_tn_alloc(bufdesc->immed_end->end_dev,
 356                                      bufdesc->immed_end->end_cpt,
 357                                      rx_msg->srcnid, alloc_msg, false,
 358                                      false);
 359                 if (IS_ERR(tn)) {
 360                         kfilnd_ep_imm_buffer_put(bufdesc);
 361                         KFILND_EP_ERROR(bufdesc->immed_end,
 362                                         "Failed to allocate transaction struct: rc=%ld",
 363                                         PTR_ERR(tn));
 364                         return;
 365                 }
 366
 367                 tn->tn_rx_msg.msg = rx_msg;
 368                 tn->tn_rx_msg.length = msg_size;
 369                 tn->tn_posted_buf = bufdesc;
 370
 371                 KFILND_EP_DEBUG(bufdesc->immed_end, "%s transaction ID %u",
 372                                 msg_type_to_str((enum kfilnd_msg_type)rx_msg->type),
 373                                 tn->tn_mr_key);
 374                 break;
 375
 376         default:
 377                 KFILND_EP_ERROR(bufdesc->immed_end,
 378                                 "Unhandled kfilnd message type: %d",
 379                                 (enum kfilnd_msg_type)rx_msg->type);
 380                 LBUG();
 381         };
 382
 383         kfilnd_tn_event_handler(tn, event, 0);
 384 }
 385
 386 static void kfilnd_tn_record_duration(struct kfilnd_transaction *tn)
 387 {
 388         unsigned int data_size_bucket =
 389                 kfilnd_msg_len_to_data_size_bucket(tn->lnet_msg_len);
 390         struct kfilnd_tn_duration_stat *stat;
 391
 392         if (tn->is_initiator)
 393                 stat = &tn->tn_ep->end_dev->initiator_stats.data_size[data_size_bucket];
 394         else
 395                 stat = &tn->tn_ep->end_dev->target_stats.data_size[data_size_bucket];
 396
 397         atomic64_add(ktime_to_ns(ktime_sub(ktime_get(), tn->tn_alloc_ts)),
 398                      &stat->accumulated_duration);
 399         atomic_inc(&stat->accumulated_count);
 400 }
 401
 402 /**
 403  * kfilnd_tn_finalize() - Cleanup resources and finalize LNet operation.
 404  *
 405  * All state machine functions should call kfilnd_tn_finalize() instead of
 406  * kfilnd_tn_free(). Once all expected asynchronous events have been received,
 407  * if the transaction lock has not been released, it will now be released,
 408  * transaction resources cleaned up, and LNet finalized will be called.
 409  */
 410 static void kfilnd_tn_finalize(struct kfilnd_transaction *tn, bool *tn_released)
 411 {
 412         if (!*tn_released) {
 413                 mutex_unlock(&tn->tn_lock);
 414                 *tn_released = true;
 415         }
 416
 417         /* Release the reference on the multi-receive buffer. */
 418         if (tn->tn_posted_buf)
 419                 kfilnd_ep_imm_buffer_put(tn->tn_posted_buf);
 420
 421         /* Finalize LNet operation. */
 422         if (tn->tn_lntmsg) {
 423                 tn->tn_lntmsg->msg_health_status = tn->hstatus;
 424                 lnet_finalize(tn->tn_lntmsg, tn->tn_status);
 425         }
 426
 427         if (tn->tn_getreply) {
 428                 tn->tn_getreply->msg_health_status = tn->hstatus;
 429                 lnet_set_reply_msg_len(tn->tn_ep->end_dev->kfd_ni,
 430                                        tn->tn_getreply,
 431                                        tn->tn_status ? 0 : tn->tn_nob);
 432                 lnet_finalize(tn->tn_getreply, tn->tn_status);
 433         }
 434
 435         if (KFILND_TN_PEER_VALID(tn))
 436                 kfilnd_peer_put(tn->peer);
 437
 438         kfilnd_tn_record_state_change(tn);
 439         kfilnd_tn_record_duration(tn);
 440
 441         kfilnd_tn_free(tn);
 442 }
 443
 444 /**
 445  * kfilnd_tn_cancel_tag_recv() - Attempt to cancel a tagged receive.
 446  * @tn: Transaction to have tagged received cancelled.
 447  *
 448  * Return: 0 on success. Else, negative errno. If an error occurs, resources may
 449  * be leaked.
 450  */
 451 static int kfilnd_tn_cancel_tag_recv(struct kfilnd_transaction *tn)
 452 {
 453         int rc;
 454
 455         /* Issue a cancel. A return code of zero means the operation issued an
 456          * async cancel. A return code of -ENOENT means the tagged receive was
 457          * not found. The assumption here is that a tagged send landed thus
 458          * removing the tagged receive buffer from hardware. For both cases,
 459          * async events should occur.
 460          */
 461         rc = kfilnd_ep_cancel_tagged_recv(tn->tn_ep, tn);
 462         if (rc != 0 && rc != -ENOENT) {
 463                 KFILND_TN_ERROR(tn, "Failed to cancel tag receive. Resources may leak.");
 464                 return rc;
 465         }
 466
 467         return 0;
 468 }
 469
 470 static void kfilnd_tn_timeout_work(struct work_struct *work)
 471 {
 472         struct kfilnd_transaction *tn =
 473                 container_of(work, struct kfilnd_transaction, timeout_work);
 474
 475         KFILND_TN_ERROR(tn, "Bulk operation timeout");
 476         kfilnd_tn_event_handler(tn, TN_EVENT_TIMEOUT, 0);
 477 }
 478
 479 static void kfilnd_tn_timeout(cfs_timer_cb_arg_t data)
 480 {
 481         struct kfilnd_transaction *tn = cfs_from_timer(tn, data, timeout_timer);
 482
 483         queue_work(kfilnd_wq, &tn->timeout_work);
 484 }
 485
 486 static bool kfilnd_tn_timeout_cancel(struct kfilnd_transaction *tn)
 487 {
 488         return del_timer(&tn->timeout_timer);
 489 }
 490
 491 static void kfilnd_tn_timeout_enable(struct kfilnd_transaction *tn)
 492 {
 493         ktime_t remaining_time = max_t(ktime_t, 0,
 494                                        tn->deadline - ktime_get_seconds());
 495         unsigned long expires = remaining_time * HZ + jiffies;
 496
 497         if (CFS_FAIL_CHECK(CFS_KFI_FAIL_BULK_TIMEOUT))
 498                 expires = jiffies;
 499
 500         cfs_timer_setup(&tn->timeout_timer, kfilnd_tn_timeout,
 501                         (unsigned long)tn, 0);
 502         mod_timer(&tn->timeout_timer, expires);
 503 }
 504
 505 /*  The following are the state machine routines for the transactions. */
 506 static int kfilnd_tn_state_send_failed(struct kfilnd_transaction *tn,
 507                                        enum tn_events event, int status,
 508                                        bool *tn_released)
 509 {
 510         int rc;
 511
 512         KFILND_TN_DEBUG(tn, "%s event status %d", tn_event_to_str(event),
 513                         status);
 514
 515         switch (event) {
 516         case TN_EVENT_INIT_BULK:
 517                 /* Need to cancel the tagged receive to prevent resources from
 518                  * being leaked.
 519                  */
 520                 rc = kfilnd_tn_cancel_tag_recv(tn);
 521
 522                 switch (rc) {
 523                 /* Async event will progress transaction. */
 524                 case 0:
 525                         kfilnd_tn_state_change(tn, TN_STATE_FAIL);
 526                         return 0;
 527
 528                 /* Need to replay TN_EVENT_INIT_BULK event while in the
 529                  * TN_STATE_SEND_FAILED state.
 530                  */
 531                 case -EAGAIN:
 532                         KFILND_TN_DEBUG(tn,
 533                                         "Need to replay cancel tagged recv");
 534                         return -EAGAIN;
 535
 536                 default:
 537                         KFILND_TN_ERROR(tn,
 538                                         "Unexpected error during cancel tagged receive: rc=%d",
 539                                         rc);
 540                         LBUG();
 541                 }
 542                 break;
 543
 544         default:
 545                 KFILND_TN_ERROR(tn, "Invalid %s event", tn_event_to_str(event));
 546                 LBUG();
 547         }
 548 }
 549
 550 static int kfilnd_tn_state_tagged_recv_posted(struct kfilnd_transaction *tn,
 551                                               enum tn_events event, int status,
 552                                               bool *tn_released)
 553 {
 554         int rc;
 555
 556         KFILND_TN_DEBUG(tn, "%s event status %d", tn_event_to_str(event),
 557                         status);
 558
 559         switch (event) {
 560         case TN_EVENT_INIT_BULK:
 561                 tn->tn_target_addr = kfilnd_peer_get_kfi_addr(tn->peer);
 562                 KFILND_TN_DEBUG(tn, "Using peer %s(%#llx)",
 563                                 libcfs_nid2str(tn->peer->nid),
 564                                 tn->tn_target_addr);
 565
 566                 kfilnd_tn_pack_bulk_req(tn);
 567
 568                 rc = kfilnd_ep_post_send(tn->tn_ep, tn);
 569                 switch (rc) {
 570                 /* Async event will progress immediate send. */
 571                 case 0:
 572                         kfilnd_tn_state_change(tn, TN_STATE_WAIT_COMP);
 573                         return 0;
 574
 575                 /* Need to replay TN_EVENT_INIT_BULK event while in the
 576                  * TN_STATE_TAGGED_RECV_POSTED state.
 577                  */
 578                 case -EAGAIN:
 579                         KFILND_TN_DEBUG(tn,
 580                                         "Need to replay post send to %s(%#llx)",
 581                                         libcfs_nid2str(tn->peer->nid),
 582                                         tn->tn_target_addr);
 583                         return -EAGAIN;
 584
 585                 /* Need to transition to the TN_STATE_SEND_FAILED to cleanup
 586                  * posted tagged receive buffer.
 587                  */
 588                 default:
 589                         KFILND_TN_ERROR(tn,
 590                                         "Failed to post send to %s(%#llx): rc=%d",
 591                                         libcfs_nid2str(tn->peer->nid),
 592                                         tn->tn_target_addr, rc);
 593                         kfilnd_tn_status_update(tn, rc,
 594                                                 LNET_MSG_STATUS_LOCAL_ERROR);
 595                         kfilnd_tn_state_change(tn, TN_STATE_SEND_FAILED);
 596
 597                         /* Propogate TN_EVENT_INIT_BULK event to
 598                          * TN_STATE_SEND_FAILED handler.
 599                          */
 600                         return kfilnd_tn_state_send_failed(tn, event, rc,
 601                                                            tn_released);
 602                 }
 603
 604         default:
 605                 KFILND_TN_ERROR(tn, "Invalid %s event", tn_event_to_str(event));
 606                 LBUG();
 607         }
 608 }
 609
 610 static int kfilnd_tn_state_idle(struct kfilnd_transaction *tn,
 611                                 enum tn_events event, int status,
 612                                 bool *tn_released)
 613 {
 614         struct kfilnd_msg *msg;
 615         int rc;
 616         bool finalize = false;
 617         ktime_t remaining_time;
 618         struct lnet_hdr hdr;
 619         struct lnet_nid srcnid;
 620
 621         KFILND_TN_DEBUG(tn, "%s event status %d", tn_event_to_str(event),
 622                         status);
 623
 624         /* For new peers, send a hello request message and queue the true LNet
 625          * message for replay.
 626          */
 627         if (kfilnd_peer_is_new_peer(tn->peer) &&
 628             (event == TN_EVENT_INIT_IMMEDIATE || event == TN_EVENT_INIT_BULK)) {
 629                 remaining_time = max_t(ktime_t, 0,
 630                                        tn->deadline - ktime_get_seconds());
 631
 632                 /* If transaction deadline has not be met, return -EAGAIN. This
 633                  * will cause this transaction event to be replayed. During this
 634                  * time, an async message from the peer should occur at which
 635                  * point the kfilnd version should be negotiated.
 636                  */
 637                 if (remaining_time > 0) {
 638                         KFILND_TN_DEBUG(tn, "%s hello response pending",
 639                                         libcfs_nid2str(tn->peer->nid));
 640                         return -EAGAIN;
 641                 }
 642
 643                 rc = 0;
 644                 kfilnd_tn_status_update(tn, -ETIMEDOUT,
 645                                         LNET_MSG_STATUS_NETWORK_TIMEOUT);
 646                 goto out;
 647         }
 648
 649         switch (event) {
 650         case TN_EVENT_INIT_IMMEDIATE:
 651         case TN_EVENT_TX_HELLO:
 652                 tn->tn_target_addr = kfilnd_peer_get_kfi_addr(tn->peer);
 653                 KFILND_TN_DEBUG(tn, "Using peer %s(%#llx)",
 654                                 libcfs_nid2str(tn->peer->nid),
 655                                 tn->tn_target_addr);
 656
 657                 if (event == TN_EVENT_INIT_IMMEDIATE)
 658                         kfilnd_tn_pack_immed_msg(tn);
 659                 else
 660                         kfilnd_tn_pack_hello_req(tn);
 661
 662                 /* Send immediate message. */
 663                 rc = kfilnd_ep_post_send(tn->tn_ep, tn);
 664                 switch (rc) {
 665                 /* Async event will progress immediate send. */
 666                 case 0:
 667                         kfilnd_tn_state_change(tn, TN_STATE_IMM_SEND);
 668                         return 0;
 669
 670                 /* Need to TN_EVENT_INIT_IMMEDIATE event while in TN_STATE_IDLE
 671                  * state.
 672                  */
 673                 case -EAGAIN:
 674                         KFILND_TN_DEBUG(tn, "Need to replay send to %s(%#llx)",
 675                                         libcfs_nid2str(tn->peer->nid),
 676                                         tn->tn_target_addr);
 677                         return -EAGAIN;
 678
 679                 default:
 680                         KFILND_TN_ERROR(tn,
 681                                         "Failed to post send to %s(%#llx): rc=%d",
 682                                         libcfs_nid2str(tn->peer->nid),
 683                                         tn->tn_target_addr, rc);
 684                         kfilnd_tn_status_update(tn, rc,
 685                                                 LNET_MSG_STATUS_LOCAL_ERROR);
 686                 }
 687                 break;
 688
 689         case TN_EVENT_INIT_BULK:
 690                 /* Post tagged receive buffer used to land bulk response. */
 691                 rc = kfilnd_ep_post_tagged_recv(tn->tn_ep, tn);
 692
 693                 switch (rc) {
 694                 /* Transition to TN_STATE_TAGGED_RECV_POSTED on success. */
 695                 case 0:
 696                         kfilnd_tn_state_change(tn, TN_STATE_TAGGED_RECV_POSTED);
 697
 698                         /* Propogate TN_EVENT_INIT_BULK event to
 699                          * TN_STATE_TAGGED_RECV_POSTED handler.
 700                          */
 701                         return kfilnd_tn_state_tagged_recv_posted(tn, event,
 702                                                                   rc,
 703                                                                   tn_released);
 704
 705                 /* Need to replay TN_EVENT_INIT_BULK event in the TN_STATE_IDLE
 706                  * state.
 707                  */
 708                 case -EAGAIN:
 709                         KFILND_TN_DEBUG(tn, "Need to replay tagged recv");
 710                         return -EAGAIN;
 711
 712                 default:
 713                         KFILND_TN_ERROR(tn, "Failed to post tagged recv %d",
 714                                         rc);
 715                         kfilnd_tn_status_update(tn, rc,
 716                                                 LNET_MSG_STATUS_LOCAL_ERROR);
 717                 }
 718                 break;
 719
 720         case TN_EVENT_RX_OK:
 721                 /* If TN_EVENT_RX_OK occurs on a new peer, this is a sign of a
 722                  * peer having a stale peer structure. Stale peer structures
 723                  * requires dropping the incoming message and initiating a hello
 724                  * handshake.
 725                  */
 726                 if (kfilnd_peer_is_new_peer(tn->peer)) {
 727                         rc = kfilnd_send_hello_request(tn->tn_ep->end_dev,
 728                                                        tn->tn_ep->end_cpt,
 729                                                        tn->peer->nid);
 730                         if (rc)
 731                                 KFILND_TN_ERROR(tn,
 732                                                 "Failed to send hello request: rc=%d",
 733                                                 rc);
 734
 735                         /* Need to drop this message since it is uses stale
 736                          * peer.
 737                          */
 738                         KFILND_TN_ERROR(tn,
 739                                         "Dropping message from %s due to stale peer",
 740                                         libcfs_nid2str(tn->peer->nid));
 741                         kfilnd_tn_status_update(tn, -EPROTO,
 742                                                 LNET_MSG_STATUS_LOCAL_DROPPED);
 743                         rc = 0;
 744                         goto out;
 745                 }
 746
 747                 LASSERT(kfilnd_peer_is_new_peer(tn->peer) == false);
 748                 msg = tn->tn_rx_msg.msg;
 749
 750                 /* Update the NID address with the new preferred RX context. */
 751                 kfilnd_peer_alive(tn->peer);
 752
 753                 /* Pass message up to LNet
 754                  * The TN will be reused in this call chain so we need to
 755                  * release the lock on the TN before proceeding.
 756                  */
 757                 KFILND_TN_DEBUG(tn, "%s -> TN_STATE_IMM_RECV state change",
 758                                 tn_state_to_str(tn->tn_state));
 759
 760                 /* TODO: Do not manually update this state change. */
 761                 tn->tn_state = TN_STATE_IMM_RECV;
 762                 mutex_unlock(&tn->tn_lock);
 763                 *tn_released = true;
 764                 lnet_nid4_to_nid(msg->srcnid, &srcnid);
 765                 if (msg->type == KFILND_MSG_IMMEDIATE) {
 766                         lnet_hdr_from_nid4(&hdr, &msg->proto.immed.hdr);
 767                         rc = lnet_parse(tn->tn_ep->end_dev->kfd_ni,
 768                                         &hdr, &srcnid, tn, 0);
 769                 } else {
 770                         lnet_hdr_from_nid4(&hdr, &msg->proto.bulk_req.hdr);
 771                         rc = lnet_parse(tn->tn_ep->end_dev->kfd_ni,
 772                                         &hdr, &srcnid, tn, 1);
 773                 }
 774
 775                 /* If successful, transaction has been accepted by LNet and we
 776                  * cannot process the transaction anymore within this context.
 777                  */
 778                 if (!rc)
 779                         return 0;
 780
 781                 KFILND_TN_ERROR(tn, "Failed to parse LNet message: rc=%d", rc);
 782                 kfilnd_tn_status_update(tn, rc, LNET_MSG_STATUS_LOCAL_ERROR);
 783                 break;
 784
 785         case TN_EVENT_RX_HELLO:
 786                 msg = tn->tn_rx_msg.msg;
 787
 788                 switch (msg->type) {
 789                 case KFILND_MSG_HELLO_REQ:
 790                         kfilnd_peer_update_rx_contexts(tn->peer,
 791                                                        msg->proto.hello.rx_base,
 792                                                        msg->proto.hello.rx_count);
 793                         kfilnd_peer_set_remote_session_key(tn->peer,
 794                                                            msg->proto.hello.session_key);
 795
 796                         /* Negotiate kfilnd version used between peers. Fallback
 797                          * to the minimum implemented kfilnd version.
 798                          */
 799                         kfilnd_peer_set_version(tn->peer,
 800                                                 min_t(__u16, KFILND_MSG_VERSION,
 801                                                     msg->proto.hello.version));
 802                         KFILND_TN_DEBUG(tn,
 803                                         "Peer kfilnd version: %u; Local kfilnd version: %u; Negotiated kfilnd verions: %u",
 804                                         msg->proto.hello.version,
 805                                         KFILND_MSG_VERSION, tn->peer->version);
 806
 807                         tn->tn_target_addr = kfilnd_peer_get_kfi_addr(tn->peer);
 808                         KFILND_TN_DEBUG(tn, "Using peer %s(%#llx)",
 809                                         libcfs_nid2str(tn->peer->nid),
 810                                         tn->tn_target_addr);
 811
 812                         kfilnd_tn_pack_hello_rsp(tn);
 813
 814                         /* Send immediate message. */
 815                         rc = kfilnd_ep_post_send(tn->tn_ep, tn);
 816                         switch (rc) {
 817                         case 0:
 818                                 kfilnd_tn_state_change(tn, TN_STATE_IMM_SEND);
 819                                 return 0;
 820
 821                         case -EAGAIN:
 822                                 KFILND_TN_DEBUG(tn, "Need to replay send to %s(%#llx)",
 823                                                 libcfs_nid2str(tn->peer->nid),
 824                                                 tn->tn_target_addr);
 825                                 return -EAGAIN;
 826
 827                         default:
 828                                 KFILND_TN_ERROR(tn,
 829                                                 "Failed to post send to %s(%#llx): rc=%d",
 830                                                 libcfs_nid2str(tn->peer->nid),
 831                                                 tn->tn_target_addr, rc);
 832                                 kfilnd_tn_status_update(tn, rc,
 833                                                         LNET_MSG_STATUS_LOCAL_ERROR);
 834                         }
 835                         break;
 836
 837                 case KFILND_MSG_HELLO_RSP:
 838                         rc = 0;
 839                         kfilnd_peer_update_rx_contexts(tn->peer,
 840                                                        msg->proto.hello.rx_base,
 841                                                        msg->proto.hello.rx_count);
 842                         kfilnd_peer_set_remote_session_key(tn->peer,
 843                                                            msg->proto.hello.session_key);
 844                         kfilnd_peer_set_version(tn->peer,
 845                                                 msg->proto.hello.version);
 846                         KFILND_TN_DEBUG(tn, "Negotiated kfilnd version: %u",
 847                                         msg->proto.hello.version);
 848                         finalize = true;
 849                         break;
 850
 851                 default:
 852                         KFILND_TN_ERROR(tn, "Invalid message type: %s",
 853                                         msg_type_to_str(msg->type));
 854                         LBUG();
 855                 }
 856                 break;
 857
 858         default:
 859                 KFILND_TN_ERROR(tn, "Invalid %s event", tn_event_to_str(event));
 860                 LBUG();
 861         }
 862
 863 out:
 864         if (kfilnd_tn_has_failed(tn))
 865                 finalize = true;
 866
 867         if (finalize)
 868                 kfilnd_tn_finalize(tn, tn_released);
 869
 870         return rc;
 871 }
 872
 873 static int kfilnd_tn_state_imm_send(struct kfilnd_transaction *tn,
 874                                     enum tn_events event, int status,
 875                                     bool *tn_released)
 876 {
 877         enum lnet_msg_hstatus hstatus;
 878
 879         KFILND_TN_DEBUG(tn, "%s event status %d", tn_event_to_str(event),
 880                         status);
 881
 882         switch (event) {
 883         case TN_EVENT_TX_FAIL:
 884                 if (status == -ETIMEDOUT || status == -EIO)
 885                         hstatus = LNET_MSG_STATUS_NETWORK_TIMEOUT;
 886                 else
 887                         hstatus = LNET_MSG_STATUS_REMOTE_ERROR;
 888
 889                 kfilnd_tn_status_update(tn, status, hstatus);
 890                 kfilnd_peer_down(tn->peer);
 891                 break;
 892
 893         case TN_EVENT_TX_OK:
 894                 kfilnd_peer_alive(tn->peer);
 895                 break;
 896
 897         default:
 898                 KFILND_TN_ERROR(tn, "Invalid %s event", tn_event_to_str(event));
 899                 LBUG();
 900         }
 901
 902         kfilnd_tn_finalize(tn, tn_released);
 903
 904         return 0;
 905 }
 906
 907 static int kfilnd_tn_state_imm_recv(struct kfilnd_transaction *tn,
 908                                     enum tn_events event, int status,
 909                                     bool *tn_released)
 910 {
 911         int rc = 0;
 912         bool finalize = false;
 913
 914         KFILND_TN_DEBUG(tn, "%s event status %d", tn_event_to_str(event),
 915                         status);
 916
 917         switch (event) {
 918         case TN_EVENT_INIT_TAG_RMA:
 919         case TN_EVENT_SKIP_TAG_RMA:
 920                 /* Release the buffer we received the request on. All relevant
 921                  * information to perform the RMA operation is stored in the
 922                  * transaction structure. This should be done before the RMA
 923                  * operation to prevent two contexts from potentially processing
 924                  * the same transaction.
 925                  *
 926                  * TODO: Prevent this from returning -EAGAIN.
 927                  */
 928                 if (tn->tn_posted_buf) {
 929                         kfilnd_ep_imm_buffer_put(tn->tn_posted_buf);
 930                         tn->tn_posted_buf = NULL;
 931                 }
 932
 933                 /* Update the KFI address to use the response RX context. */
 934                 tn->tn_target_addr =
 935                         kfi_rx_addr(KFILND_BASE_ADDR(tn->peer->addr),
 936                                     tn->tn_response_rx, KFILND_FAB_RX_CTX_BITS);
 937                 KFILND_TN_DEBUG(tn, "Using peer %s(0x%llx)",
 938                                 libcfs_nid2str(tn->peer->nid),
 939                                 tn->tn_target_addr);
 940
 941                 /* Initiate the RMA operation to push/pull the LNet payload or
 942                  * send a tagged message to finalize the bulk operation if the
 943                  * RMA operation should be skipped.
 944                  */
 945                 if (event == TN_EVENT_INIT_TAG_RMA) {
 946                         if (tn->sink_buffer)
 947                                 rc = kfilnd_ep_post_read(tn->tn_ep, tn);
 948                         else
 949                                 rc = kfilnd_ep_post_write(tn->tn_ep, tn);
 950
 951                         switch (rc) {
 952                         /* Async tagged RMA event will progress transaction. */
 953                         case 0:
 954                                 kfilnd_tn_state_change(tn,
 955                                                        TN_STATE_WAIT_TAG_RMA_COMP);
 956                                 return 0;
 957
 958                         /* Need to replay TN_EVENT_INIT_TAG_RMA event while in
 959                          * the TN_STATE_IMM_RECV state.
 960                          */
 961                         case -EAGAIN:
 962                                 KFILND_TN_DEBUG(tn,
 963                                                 "Need to replay tagged %s to %s(%#llx)",
 964                                                 tn->sink_buffer ? "read" : "write",
 965                                                 libcfs_nid2str(tn->peer->nid),
 966                                                 tn->tn_target_addr);
 967                                 return -EAGAIN;
 968
 969                         default:
 970                                 KFILND_TN_ERROR(tn,
 971                                                 "Failed to post tagged %s to %s(%#llx): rc=%d",
 972                                                 tn->sink_buffer ? "read" : "write",
 973                                                 libcfs_nid2str(tn->peer->nid),
 974                                                 tn->tn_target_addr, rc);
 975                                 kfilnd_tn_status_update(tn, rc,
 976                                                         LNET_MSG_STATUS_LOCAL_ERROR);
 977                         }
 978                 } else {
 979                         kfilnd_tn_status_update(tn, status,
 980                                                 LNET_MSG_STATUS_OK);
 981
 982                         /* Since the LNet initiator has posted a unique tagged
 983                          * buffer specific for this LNet transaction and the
 984                          * LNet target has decide not to push/pull to/for the
 985                          * LNet initiator tagged buffer, a noop operation is
 986                          * done to this tagged buffer (i/e payload transfer size
 987                          * is zero). But, immediate data, which contains the
 988                          * LNet target status for the transaction, is sent to
 989                          * the LNet initiator. Immediate data only appears in
 990                          * the completion event at the LNet initiator and not in
 991                          * the tagged buffer.
 992                          */
 993                         tn->tagged_data = cpu_to_be64(abs(tn->tn_status));
 994
 995                         rc = kfilnd_ep_post_tagged_send(tn->tn_ep, tn);
 996                         switch (rc) {
 997                         /* Async tagged RMA event will progress transaction. */
 998                         case 0:
 999                                 kfilnd_tn_state_change(tn,
1000                                                        TN_STATE_WAIT_TAG_COMP);
1001                                 return 0;
1002
1003                         /* Need to replay TN_EVENT_SKIP_TAG_RMA event while in
1004                          * the TN_STATE_IMM_RECV state.
1005                          */
1006                         case -EAGAIN:
1007                                 KFILND_TN_DEBUG(tn,
1008                                                 "Need to replay tagged send to %s(%#llx)",
1009                                                 libcfs_nid2str(tn->peer->nid),
1010                                                 tn->tn_target_addr);
1011                                 return -EAGAIN;
1012
1013                         default:
1014                                 KFILND_TN_ERROR(tn,
1015                                                 "Failed to post tagged send to %s(%#llx): rc=%d",
1016                                                 libcfs_nid2str(tn->peer->nid),
1017                                                 tn->tn_target_addr, rc);
1018                                 kfilnd_tn_status_update(tn, rc,
1019                                                         LNET_MSG_STATUS_LOCAL_ERROR);
1020                         }
1021                 }
1022                 break;
1023
1024         case TN_EVENT_RX_OK:
1025                 finalize = true;
1026                 break;
1027
1028         default:
1029                 KFILND_TN_ERROR(tn, "Invalid %s event", tn_event_to_str(event));
1030                 LBUG();
1031         }
1032
1033         if (kfilnd_tn_has_failed(tn))
1034                 finalize = true;
1035
1036         if (finalize)
1037                 kfilnd_tn_finalize(tn, tn_released);
1038
1039         return rc;
1040 }
1041
1042 static int kfilnd_tn_state_wait_comp(struct kfilnd_transaction *tn,
1043                                      enum tn_events event, int status,
1044                                      bool *tn_released)
1045 {
1046         int rc;
1047         enum lnet_msg_hstatus hstatus;
1048
1049         KFILND_TN_DEBUG(tn, "%s event status %d", tn_event_to_str(event),
1050                         status);
1051
1052         switch (event) {
1053         case TN_EVENT_TX_OK:
1054                 kfilnd_peer_alive(tn->peer);
1055                 kfilnd_tn_timeout_enable(tn);
1056                 kfilnd_tn_state_change(tn, TN_STATE_WAIT_TAG_COMP);
1057                 break;
1058
1059         case TN_EVENT_TAG_RX_OK:
1060                 kfilnd_tn_state_change(tn, TN_STATE_WAIT_SEND_COMP);
1061                 break;
1062
1063         case TN_EVENT_TX_FAIL:
1064                 if (status == -ETIMEDOUT)
1065                         hstatus = LNET_MSG_STATUS_NETWORK_TIMEOUT;
1066                 else
1067                         hstatus = LNET_MSG_STATUS_REMOTE_ERROR;
1068
1069                 kfilnd_tn_status_update(tn, status, hstatus);
1070                 kfilnd_peer_down(tn->peer);
1071
1072                 /* Need to cancel the tagged receive to prevent resources from
1073                  * being leaked.
1074                  */
1075                 rc = kfilnd_tn_cancel_tag_recv(tn);
1076
1077                 switch (rc) {
1078                 /* Async cancel event will progress transaction. */
1079                 case 0:
1080                         kfilnd_tn_status_update(tn, status,
1081                                                 LNET_MSG_STATUS_LOCAL_ERROR);
1082                         kfilnd_tn_state_change(tn, TN_STATE_FAIL);
1083                         return 0;
1084
1085                 /* Need to replay TN_EVENT_INIT_BULK event while in the
1086                  * TN_STATE_SEND_FAILED state.
1087                  */
1088                 case -EAGAIN:
1089                         KFILND_TN_DEBUG(tn,
1090                                         "Need to replay cancel tagged recv");
1091                         return -EAGAIN;
1092
1093                 default:
1094                         KFILND_TN_ERROR(tn,
1095                                         "Unexpected error during cancel tagged receive: rc=%d",
1096                                         rc);
1097                         LBUG();
1098                 }
1099                 break;
1100
1101         case TN_EVENT_TAG_RX_FAIL:
1102                 kfilnd_tn_status_update(tn, status,
1103                                         LNET_MSG_STATUS_LOCAL_ERROR);
1104                 kfilnd_tn_state_change(tn, TN_STATE_FAIL);
1105                 break;
1106
1107         default:
1108                 KFILND_TN_ERROR(tn, "Invalid %s event", tn_event_to_str(event));
1109                 LBUG();
1110         }
1111
1112         return 0;
1113 }
1114
1115 static int kfilnd_tn_state_wait_send_comp(struct kfilnd_transaction *tn,
1116                                           enum tn_events event, int status,
1117                                           bool *tn_released)
1118 {
1119         KFILND_TN_DEBUG(tn, "%s event status %d", tn_event_to_str(event),
1120                         status);
1121
1122         if (event == TN_EVENT_TX_OK) {
1123                 kfilnd_peer_alive(tn->peer);
1124                 kfilnd_tn_finalize(tn, tn_released);
1125         } else {
1126                 KFILND_TN_ERROR(tn, "Invalid %s event", tn_event_to_str(event));
1127                 LBUG();
1128         }
1129
1130         return 0;
1131 }
1132
1133 static int kfilnd_tn_state_wait_tag_rma_comp(struct kfilnd_transaction *tn,
1134                                              enum tn_events event, int status,
1135                                              bool *tn_released)
1136 {
1137         enum lnet_msg_hstatus hstatus;
1138
1139         KFILND_TN_DEBUG(tn, "%s event status %d", tn_event_to_str(event),
1140                         status);
1141
1142         switch (event) {
1143         case TN_EVENT_TAG_TX_OK:
1144                 kfilnd_peer_alive(tn->peer);
1145                 break;
1146
1147         case TN_EVENT_TAG_TX_FAIL:
1148                 if (status == -ETIMEDOUT)
1149                         hstatus = LNET_MSG_STATUS_NETWORK_TIMEOUT;
1150                 else
1151                         hstatus = LNET_MSG_STATUS_REMOTE_ERROR;
1152
1153                 kfilnd_tn_status_update(tn, status, hstatus);
1154                 kfilnd_peer_down(tn->peer);
1155                 break;
1156
1157         default:
1158                 KFILND_TN_ERROR(tn, "Invalid %s event", tn_event_to_str(event));
1159                 LBUG();
1160         }
1161
1162         kfilnd_tn_finalize(tn, tn_released);
1163
1164         return 0;
1165 }
1166
1167 static int kfilnd_tn_state_wait_tag_comp(struct kfilnd_transaction *tn,
1168                                          enum tn_events event, int status,
1169                                          bool *tn_released)
1170 {
1171         int rc;
1172         enum lnet_msg_hstatus hstatus;
1173
1174         KFILND_TN_DEBUG(tn, "%s event status %d", tn_event_to_str(event),
1175                         status);
1176
1177         switch (event) {
1178         case TN_EVENT_TAG_RX_FAIL:
1179         case TN_EVENT_TAG_RX_OK:
1180                 /* Status can be set for both TN_EVENT_TAG_RX_FAIL and
1181                  * TN_EVENT_TAG_RX_OK. For TN_EVENT_TAG_RX_OK, if status is set,
1182                  * LNet target returned -ENODATA.
1183                  */
1184                 if (status) {
1185                         if (event == TN_EVENT_TAG_RX_FAIL)
1186                                 kfilnd_tn_status_update(tn, status,
1187                                                         LNET_MSG_STATUS_LOCAL_ERROR);
1188                         else
1189                                 kfilnd_tn_status_update(tn, status,
1190                                                         LNET_MSG_STATUS_OK);
1191                 }
1192
1193                 if (!kfilnd_tn_timeout_cancel(tn)) {
1194                         kfilnd_tn_state_change(tn, TN_STATE_WAIT_TIMEOUT_COMP);
1195                         return 0;
1196                 }
1197                 break;
1198
1199         case TN_EVENT_TIMEOUT:
1200                 /* Need to cancel the tagged receive to prevent resources from
1201                  * being leaked.
1202                  */
1203                 rc = kfilnd_tn_cancel_tag_recv(tn);
1204
1205                 switch (rc) {
1206                 /* Async cancel event will progress transaction. */
1207                 case 0:
1208                         kfilnd_tn_state_change(tn,
1209                                                TN_STATE_WAIT_TIMEOUT_TAG_COMP);
1210                         return 0;
1211
1212                 /* Need to replay TN_EVENT_INIT_BULK event while in the
1213                  * TN_STATE_WAIT_TAG_COMP state.
1214                  */
1215                 case -EAGAIN:
1216                         KFILND_TN_DEBUG(tn,
1217                                         "Need to replay cancel tagged recv");
1218                         return -EAGAIN;
1219
1220                 default:
1221                         KFILND_TN_ERROR(tn,
1222                                         "Unexpected error during cancel tagged receive: rc=%d",
1223                                         rc);
1224                         LBUG();
1225                 }
1226                 break;
1227
1228         case TN_EVENT_TAG_TX_FAIL:
1229                 if (status == -ETIMEDOUT)
1230                         hstatus = LNET_MSG_STATUS_NETWORK_TIMEOUT;
1231                 else
1232                         hstatus = LNET_MSG_STATUS_REMOTE_ERROR;
1233
1234                 kfilnd_tn_status_update(tn, status, hstatus);
1235                 kfilnd_peer_down(tn->peer);
1236                 break;
1237
1238         case TN_EVENT_TAG_TX_OK:
1239                 kfilnd_peer_alive(tn->peer);
1240                 break;
1241
1242         default:
1243                 KFILND_TN_ERROR(tn, "Invalid %s event", tn_event_to_str(event));
1244                 LBUG();
1245         }
1246
1247         kfilnd_tn_finalize(tn, tn_released);
1248
1249         return 0;
1250 }
1251
1252 static int kfilnd_tn_state_fail(struct kfilnd_transaction *tn,
1253                                 enum tn_events event, int status,
1254                                 bool *tn_released)
1255 {
1256         KFILND_TN_DEBUG(tn, "%s event status %d", tn_event_to_str(event),
1257                         status);
1258
1259         switch (event) {
1260         case TN_EVENT_TX_FAIL:
1261                 kfilnd_peer_down(tn->peer);
1262                 break;
1263
1264         case TN_EVENT_TX_OK:
1265                 kfilnd_peer_alive(tn->peer);
1266                 break;
1267
1268         case TN_EVENT_TAG_RX_FAIL:
1269         case TN_EVENT_TAG_RX_CANCEL:
1270                 break;
1271
1272         default:
1273                 KFILND_TN_ERROR(tn, "Invalid %s event", tn_event_to_str(event));
1274                 LBUG();
1275         }
1276
1277         kfilnd_tn_finalize(tn, tn_released);
1278
1279         return 0;
1280 }
1281
1282 static int kfilnd_tn_state_wait_timeout_tag_comp(struct kfilnd_transaction *tn,
1283                                                  enum tn_events event,
1284                                                  int status, bool *tn_released)
1285 {
1286         KFILND_TN_DEBUG(tn, "%s event status %d", tn_event_to_str(event),
1287                         status);
1288
1289         switch (event) {
1290         case TN_EVENT_TAG_RX_CANCEL:
1291                 kfilnd_tn_status_update(tn, -ETIMEDOUT,
1292                                         LNET_MSG_STATUS_REMOTE_TIMEOUT);
1293                 kfilnd_peer_down(tn->peer);
1294                 break;
1295
1296         case TN_EVENT_TAG_RX_FAIL:
1297                 kfilnd_tn_status_update(tn, status,
1298                                         LNET_MSG_STATUS_LOCAL_ERROR);
1299                 break;
1300
1301         case TN_EVENT_TAG_RX_OK:
1302                 break;
1303
1304         default:
1305                 KFILND_TN_ERROR(tn, "Invalid %s event", tn_event_to_str(event));
1306                 LBUG();
1307         }
1308
1309         kfilnd_tn_finalize(tn, tn_released);
1310
1311         return 0;
1312 }
1313
1314 static int kfilnd_tn_state_wait_timeout_comp(struct kfilnd_transaction *tn,
1315                                              enum tn_events event, int status,
1316                                              bool *tn_released)
1317 {
1318         KFILND_TN_DEBUG(tn, "%s event status %d", tn_event_to_str(event),
1319                         status);
1320
1321         if (event == TN_EVENT_TIMEOUT) {
1322                 kfilnd_tn_finalize(tn, tn_released);
1323         } else {
1324                 KFILND_TN_ERROR(tn, "Invalid %s event", tn_event_to_str(event));
1325                 LBUG();
1326         }
1327
1328         return 0;
1329 }
1330
1331 static int
1332 (* const kfilnd_tn_state_dispatch_table[TN_STATE_MAX])(struct kfilnd_transaction *tn,
1333                                                        enum tn_events event,
1334                                                        int status,
1335                                                        bool *tn_released) = {
1336         [TN_STATE_IDLE] = kfilnd_tn_state_idle,
1337         [TN_STATE_WAIT_TAG_COMP] = kfilnd_tn_state_wait_tag_comp,
1338         [TN_STATE_IMM_SEND] = kfilnd_tn_state_imm_send,
1339         [TN_STATE_TAGGED_RECV_POSTED] = kfilnd_tn_state_tagged_recv_posted,
1340         [TN_STATE_SEND_FAILED] = kfilnd_tn_state_send_failed,
1341         [TN_STATE_WAIT_COMP] = kfilnd_tn_state_wait_comp,
1342         [TN_STATE_WAIT_TIMEOUT_COMP] = kfilnd_tn_state_wait_timeout_comp,
1343         [TN_STATE_WAIT_SEND_COMP] = kfilnd_tn_state_wait_send_comp,
1344         [TN_STATE_WAIT_TIMEOUT_TAG_COMP] =
1345                 kfilnd_tn_state_wait_timeout_tag_comp,
1346         [TN_STATE_FAIL] = kfilnd_tn_state_fail,
1347         [TN_STATE_IMM_RECV] = kfilnd_tn_state_imm_recv,
1348         [TN_STATE_WAIT_TAG_RMA_COMP] = kfilnd_tn_state_wait_tag_rma_comp,
1349 };
1350
1351 /**
1352  * kfilnd_tn_event_handler() - Update transaction state machine with an event.
1353  * @tn: Transaction to be updated.
1354  * @event: Transaction event.
1355  * @status: Errno status associated with the event.
1356  *
1357  * When the transaction event handler is first called on a new transaction, the
1358  * transaction is now own by the transaction system. This means that will be
1359  * freed by the system as the transaction is progressed through the state
1360  * machine.
1361  */
1362 void kfilnd_tn_event_handler(struct kfilnd_transaction *tn,
1363                              enum tn_events event, int status)
1364 {
1365         bool tn_released = false;
1366         int rc;
1367
1368         if (!tn)
1369                 return;
1370
1371         mutex_lock(&tn->tn_lock);
1372         rc = kfilnd_tn_state_dispatch_table[tn->tn_state](tn, event, status,
1373                                                           &tn_released);
1374         if (rc == -EAGAIN) {
1375                 tn->replay_event = event;
1376                 tn->replay_status = status;
1377                 kfilnd_ep_queue_tn_replay(tn->tn_ep, tn);
1378         }
1379
1380         if (!tn_released)
1381                 mutex_unlock(&tn->tn_lock);
1382 }
1383
1384 /**
1385  * kfilnd_tn_free() - Free a transaction.
1386  */
1387 void kfilnd_tn_free(struct kfilnd_transaction *tn)
1388 {
1389         spin_lock(&tn->tn_ep->tn_list_lock);
1390         list_del(&tn->tn_entry);
1391         spin_unlock(&tn->tn_ep->tn_list_lock);
1392
1393         KFILND_TN_DEBUG(tn, "Transaction freed");
1394
1395         if (tn->tn_mr_key)
1396                 kfilnd_ep_put_key(tn->tn_ep, tn->tn_mr_key);
1397
1398         /* Free send message buffer if needed. */
1399         if (tn->tn_tx_msg.msg)
1400                 kmem_cache_free(imm_buf_cache, tn->tn_tx_msg.msg);
1401
1402         kmem_cache_free(tn_cache, tn);
1403 }
1404
1405 /**
1406  * kfilnd_tn_alloc() - Allocate a new KFI LND transaction.
1407  * @dev: KFI LND device used to look the KFI LND endpoint to associate with the
1408  * transaction.
1409  * @cpt: CPT of the transaction.
1410  * @target_nid: Target NID of the transaction.
1411  * @alloc_msg: Allocate an immediate message for the transaction.
1412  * @is_initiator: Is initiator of LNet transaction.
1413  * @key: Is transaction memory region key need.
1414  *
1415  * During transaction allocation, each transaction is associated with a KFI LND
1416  * endpoint use to post data transfer operations. The CPT argument is used to
1417  * lookup the KFI LND endpoint within the KFI LND device.
1418  *
1419  * Return: On success, valid pointer. Else, negative errno pointer.
1420  */
1421 struct kfilnd_transaction *kfilnd_tn_alloc(struct kfilnd_dev *dev, int cpt,
1422                                            lnet_nid_t target_nid,
1423                                            bool alloc_msg, bool is_initiator,
1424                                            bool key)
1425 {
1426         struct kfilnd_transaction *tn;
1427         struct kfilnd_ep *ep;
1428         int rc;
1429         ktime_t tn_alloc_ts;
1430
1431         if (!dev) {
1432                 rc = -EINVAL;
1433                 goto err;
1434         }
1435
1436         tn_alloc_ts = ktime_get();
1437
1438         /* If the CPT does not fall into the LNet NI CPT range, force the CPT
1439          * into the LNet NI CPT range. This should never happen.
1440          */
1441         ep = dev->cpt_to_endpoint[cpt];
1442         if (!ep) {
1443                 CWARN("%s used invalid cpt=%d\n",
1444                       libcfs_nidstr(&dev->kfd_ni->ni_nid), cpt);
1445                 ep = dev->kfd_endpoints[0];
1446         }
1447
1448         tn = kmem_cache_zalloc(tn_cache, GFP_KERNEL);
1449         if (!tn) {
1450                 rc = -ENOMEM;
1451                 goto err;
1452         }
1453
1454         if (alloc_msg) {
1455                 tn->tn_tx_msg.msg = kmem_cache_alloc(imm_buf_cache, GFP_KERNEL);
1456                 if (!tn->tn_tx_msg.msg) {
1457                         rc = -ENOMEM;
1458                         goto err_free_tn;
1459                 }
1460         }
1461
1462         if (key) {
1463                 rc = kfilnd_ep_get_key(ep);
1464                 if (rc < 0)
1465                         goto err_free_tn;
1466                 tn->tn_mr_key = rc;
1467         }
1468
1469         tn->peer = kfilnd_peer_get(dev, target_nid);
1470         if (IS_ERR(tn->peer)) {
1471                 rc = PTR_ERR(tn->peer);
1472                 goto err_put_mr_key;
1473         }
1474
1475         mutex_init(&tn->tn_lock);
1476         tn->tn_ep = ep;
1477         tn->tn_response_rx = ep->end_context_id;
1478         tn->tn_state = TN_STATE_IDLE;
1479         tn->hstatus = LNET_MSG_STATUS_OK;
1480         tn->deadline = ktime_get_seconds() + lnet_get_lnd_timeout();
1481         tn->is_initiator = is_initiator;
1482         INIT_WORK(&tn->timeout_work, kfilnd_tn_timeout_work);
1483
1484         /* Add the transaction to an endpoint.  This is like
1485          * incrementing a ref counter.
1486          */
1487         spin_lock(&ep->tn_list_lock);
1488         list_add_tail(&tn->tn_entry, &ep->tn_list);
1489         spin_unlock(&ep->tn_list_lock);
1490
1491         tn->tn_alloc_ts = tn_alloc_ts;
1492         tn->tn_state_ts = ktime_get();
1493
1494         KFILND_EP_DEBUG(ep, "Transaction ID %u allocated", tn->tn_mr_key);
1495
1496         return tn;
1497
1498 err_put_mr_key:
1499         if (key)
1500                 kfilnd_ep_put_key(ep, tn->tn_mr_key);
1501 err_free_tn:
1502         if (tn->tn_tx_msg.msg)
1503                 kmem_cache_free(imm_buf_cache, tn->tn_tx_msg.msg);
1504         kmem_cache_free(tn_cache, tn);
1505 err:
1506         return ERR_PTR(rc);
1507 }
1508
1509 /**
1510  * kfilnd_tn_cleanup() - Cleanup KFI LND transaction system.
1511  *
1512  * This function should only be called when there are no outstanding
1513  * transactions.
1514  */
1515 void kfilnd_tn_cleanup(void)
1516 {
1517         kmem_cache_destroy(imm_buf_cache);
1518         kmem_cache_destroy(tn_cache);
1519 }
1520
1521 /**
1522  * kfilnd_tn_init() - Initialize KFI LND transaction system.
1523  *
1524  * Return: On success, zero. Else, negative errno.
1525  */
1526 int kfilnd_tn_init(void)
1527 {
1528         tn_cache = kmem_cache_create("kfilnd_tn",
1529                                      sizeof(struct kfilnd_transaction), 0,
1530                                      SLAB_HWCACHE_ALIGN, NULL);
1531         if (!tn_cache)
1532                 goto err;
1533
1534         imm_buf_cache = kmem_cache_create("kfilnd_imm_buf",
1535                                           KFILND_IMMEDIATE_MSG_SIZE, 0,
1536                                           SLAB_HWCACHE_ALIGN, NULL);
1537         if (!imm_buf_cache)
1538                 goto err_tn_cache_destroy;
1539
1540         return 0;
1541
1542 err_tn_cache_destroy:
1543         kmem_cache_destroy(tn_cache);
1544 err:
1545         return -ENOMEM;
1546 }
1547
1548 /**
1549  * kfilnd_tn_set_kiov_buf() - Set the buffer used for a transaction.
1550  * @tn: Transaction to have buffer set.
1551  * @kiov: LNet KIOV buffer.
1552  * @num_iov: Number of IOVs.
1553  * @offset: Offset into IOVs where the buffer starts.
1554  * @len: Length of the buffer.
1555  *
1556  * This function takes the user provided IOV, offset, and len, and sets the
1557  * transaction buffer. The user provided IOV is an LNet KIOV. When the
1558  * transaction buffer is configured, the user provided offset is applied
1559  * when the transaction buffer is configured (i.e. the transaction buffer
1560  * offset is zero).
1561  */
1562 int kfilnd_tn_set_kiov_buf(struct kfilnd_transaction *tn,
1563                            struct bio_vec *kiov, size_t num_iov,
1564                            size_t offset, size_t len)
1565 {
1566         size_t i;
1567         size_t cur_len = 0;
1568         size_t cur_offset = offset;
1569         size_t cur_iov = 0;
1570         size_t tmp_len;
1571         size_t tmp_offset;
1572
1573         for (i = 0; (i < num_iov) && (cur_len < len); i++) {
1574                 /* Skip KIOVs until a KIOV with a length less than the current
1575                  * offset is found.
1576                  */
1577                 if (kiov[i].bv_len <= cur_offset) {
1578                         cur_offset -= kiov[i].bv_len;
1579                         continue;
1580                 }
1581
1582                 tmp_len = kiov[i].bv_len - cur_offset;
1583                 tmp_offset = kiov[i].bv_len - tmp_len + kiov[i].bv_offset;
1584
1585                 if (tmp_len + cur_len > len)
1586                         tmp_len = len - cur_len;
1587
1588                 /* tn_kiov is an array of size LNET_MAX_IOV */
1589                 if (cur_iov >= LNET_MAX_IOV)
1590                         return -EINVAL;
1591
1592                 tn->tn_kiov[cur_iov].bv_page = kiov[i].bv_page;
1593                 tn->tn_kiov[cur_iov].bv_len = tmp_len;
1594                 tn->tn_kiov[cur_iov].bv_offset = tmp_offset;
1595
1596                 cur_iov++;
1597                 cur_len += tmp_len;
1598                 cur_offset = 0;
1599         }
1600
1601         tn->tn_num_iovec = cur_iov;
1602         tn->tn_nob = cur_len;
1603
1604         return 0;
1605 }