fs/cifs/smbdirect.c

   1 /*
   2  *   Copyright (C) 2017, Microsoft Corporation.
   3  *
   4  *   Author(s): Long Li <longli@microsoft.com>
   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 as published by
   8  *   the Free Software Foundation; either version 2 of the License, or
   9  *   (at your option) any later version.
  10  *
  11  *   This program is distributed in the hope that it will be useful,
  12  *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
  13  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
  14  *   the GNU General Public License for more details.
  15  */
  16 #include <linux/module.h>
  17 #include <linux/highmem.h>
  18 #include "smbdirect.h"
  19 #include "cifs_debug.h"
  20 #include "cifsproto.h"
  21 #include "smb2proto.h"
  22
  23 static struct smbd_response *get_empty_queue_buffer(
  24                 struct smbd_connection *info);
  25 static struct smbd_response *get_receive_buffer(
  26                 struct smbd_connection *info);
  27 static void put_receive_buffer(
  28                 struct smbd_connection *info,
  29                 struct smbd_response *response);
  30 static int allocate_receive_buffers(struct smbd_connection *info, int num_buf);
  31 static void destroy_receive_buffers(struct smbd_connection *info);
  32
  33 static void put_empty_packet(
  34                 struct smbd_connection *info, struct smbd_response *response);
  35 static void enqueue_reassembly(
  36                 struct smbd_connection *info,
  37                 struct smbd_response *response, int data_length);
  38 static struct smbd_response *_get_first_reassembly(
  39                 struct smbd_connection *info);
  40
  41 static int smbd_post_recv(
  42                 struct smbd_connection *info,
  43                 struct smbd_response *response);
  44
  45 static int smbd_post_send_empty(struct smbd_connection *info);
  46 static int smbd_post_send_data(
  47                 struct smbd_connection *info,
  48                 struct kvec *iov, int n_vec, int remaining_data_length);
  49 static int smbd_post_send_page(struct smbd_connection *info,
  50                 struct page *page, unsigned long offset,
  51                 size_t size, int remaining_data_length);
  52
  53 static void destroy_mr_list(struct smbd_connection *info);
  54 static int allocate_mr_list(struct smbd_connection *info);
  55
  56 /* SMBD version number */
  57 #define SMBD_V1 0x0100
  58
  59 /* Port numbers for SMBD transport */
  60 #define SMB_PORT        445
  61 #define SMBD_PORT       5445
  62
  63 /* Address lookup and resolve timeout in ms */
  64 #define RDMA_RESOLVE_TIMEOUT    5000
  65
  66 /* SMBD negotiation timeout in seconds */
  67 #define SMBD_NEGOTIATE_TIMEOUT  120
  68
  69 /* SMBD minimum receive size and fragmented sized defined in [MS-SMBD] */
  70 #define SMBD_MIN_RECEIVE_SIZE           128
  71 #define SMBD_MIN_FRAGMENTED_SIZE        131072
  72
  73 /*
  74  * Default maximum number of RDMA read/write outstanding on this connection
  75  * This value is possibly decreased during QP creation on hardware limit
  76  */
  77 #define SMBD_CM_RESPONDER_RESOURCES     32
  78
  79 /* Maximum number of retries on data transfer operations */
  80 #define SMBD_CM_RETRY                   6
  81 /* No need to retry on Receiver Not Ready since SMBD manages credits */
  82 #define SMBD_CM_RNR_RETRY               0
  83
  84 /*
  85  * User configurable initial values per SMBD transport connection
  86  * as defined in [MS-SMBD] 3.1.1.1
  87  * Those may change after a SMBD negotiation
  88  */
  89 /* The local peer's maximum number of credits to grant to the peer */
  90 int smbd_receive_credit_max = 255;
  91
  92 /* The remote peer's credit request of local peer */
  93 int smbd_send_credit_target = 255;
  94
  95 /* The maximum single message size can be sent to remote peer */
  96 int smbd_max_send_size = 1364;
  97
  98 /*  The maximum fragmented upper-layer payload receive size supported */
  99 int smbd_max_fragmented_recv_size = 1024 * 1024;
 100
 101 /*  The maximum single-message size which can be received */
 102 int smbd_max_receive_size = 8192;
 103
 104 /* The timeout to initiate send of a keepalive message on idle */
 105 int smbd_keep_alive_interval = 120;
 106
 107 /*
 108  * User configurable initial values for RDMA transport
 109  * The actual values used may be lower and are limited to hardware capabilities
 110  */
 111 /* Default maximum number of SGEs in a RDMA write/read */
 112 int smbd_max_frmr_depth = 2048;
 113
 114 /* If payload is less than this byte, use RDMA send/recv not read/write */
 115 int rdma_readwrite_threshold = 4096;
 116
 117 /* Transport logging functions
 118  * Logging are defined as classes. They can be OR'ed to define the actual
 119  * logging level via module parameter smbd_logging_class
 120  * e.g. cifs.smbd_logging_class=0xa0 will log all log_rdma_recv() and
 121  * log_rdma_event()
 122  */
 123 #define LOG_OUTGOING                    0x1
 124 #define LOG_INCOMING                    0x2
 125 #define LOG_READ                        0x4
 126 #define LOG_WRITE                       0x8
 127 #define LOG_RDMA_SEND                   0x10
 128 #define LOG_RDMA_RECV                   0x20
 129 #define LOG_KEEP_ALIVE                  0x40
 130 #define LOG_RDMA_EVENT                  0x80
 131 #define LOG_RDMA_MR                     0x100
 132 static unsigned int smbd_logging_class;
 133 module_param(smbd_logging_class, uint, 0644);
 134 MODULE_PARM_DESC(smbd_logging_class,
 135         "Logging class for SMBD transport 0x0 to 0x100");
 136
 137 #define ERR             0x0
 138 #define INFO            0x1
 139 static unsigned int smbd_logging_level = ERR;
 140 module_param(smbd_logging_level, uint, 0644);
 141 MODULE_PARM_DESC(smbd_logging_level,
 142         "Logging level for SMBD transport, 0 (default): error, 1: info");
 143
 144 #define log_rdma(level, class, fmt, args...)                            \
 145 do {                                                                    \
 146         if (level <= smbd_logging_level || class & smbd_logging_class)  \
 147                 cifs_dbg(VFS, "%s:%d " fmt, __func__, __LINE__, ##args);\
 148 } while (0)
 149
 150 #define log_outgoing(level, fmt, args...) \
 151                 log_rdma(level, LOG_OUTGOING, fmt, ##args)
 152 #define log_incoming(level, fmt, args...) \
 153                 log_rdma(level, LOG_INCOMING, fmt, ##args)
 154 #define log_read(level, fmt, args...)   log_rdma(level, LOG_READ, fmt, ##args)
 155 #define log_write(level, fmt, args...)  log_rdma(level, LOG_WRITE, fmt, ##args)
 156 #define log_rdma_send(level, fmt, args...) \
 157                 log_rdma(level, LOG_RDMA_SEND, fmt, ##args)
 158 #define log_rdma_recv(level, fmt, args...) \
 159                 log_rdma(level, LOG_RDMA_RECV, fmt, ##args)
 160 #define log_keep_alive(level, fmt, args...) \
 161                 log_rdma(level, LOG_KEEP_ALIVE, fmt, ##args)
 162 #define log_rdma_event(level, fmt, args...) \
 163                 log_rdma(level, LOG_RDMA_EVENT, fmt, ##args)
 164 #define log_rdma_mr(level, fmt, args...) \
 165                 log_rdma(level, LOG_RDMA_MR, fmt, ##args)
 166
 167 /*
 168  * Destroy the transport and related RDMA and memory resources
 169  * Need to go through all the pending counters and make sure on one is using
 170  * the transport while it is destroyed
 171  */
 172 static void smbd_destroy_rdma_work(struct work_struct *work)
 173 {
 174         struct smbd_response *response;
 175         struct smbd_connection *info =
 176                 container_of(work, struct smbd_connection, destroy_work);
 177         unsigned long flags;
 178
 179         log_rdma_event(INFO, "destroying qp\n");
 180         ib_drain_qp(info->id->qp);
 181         rdma_destroy_qp(info->id);
 182
 183         /* Unblock all I/O waiting on the send queue */
 184         wake_up_interruptible_all(&info->wait_send_queue);
 185
 186         log_rdma_event(INFO, "cancelling idle timer\n");
 187         cancel_delayed_work_sync(&info->idle_timer_work);
 188         log_rdma_event(INFO, "cancelling send immediate work\n");
 189         cancel_delayed_work_sync(&info->send_immediate_work);
 190
 191         log_rdma_event(INFO, "wait for all send to finish\n");
 192         wait_event(info->wait_smbd_send_pending,
 193                 info->smbd_send_pending == 0);
 194
 195         log_rdma_event(INFO, "wait for all recv to finish\n");
 196         wake_up_interruptible(&info->wait_reassembly_queue);
 197         wait_event(info->wait_smbd_recv_pending,
 198                 info->smbd_recv_pending == 0);
 199
 200         log_rdma_event(INFO, "wait for all send posted to IB to finish\n");
 201         wait_event(info->wait_send_pending,
 202                 atomic_read(&info->send_pending) == 0);
 203         wait_event(info->wait_send_payload_pending,
 204                 atomic_read(&info->send_payload_pending) == 0);
 205
 206         log_rdma_event(INFO, "freeing mr list\n");
 207         wake_up_interruptible_all(&info->wait_mr);
 208         wait_event(info->wait_for_mr_cleanup,
 209                 atomic_read(&info->mr_used_count) == 0);
 210         destroy_mr_list(info);
 211
 212         /* It's not posssible for upper layer to get to reassembly */
 213         log_rdma_event(INFO, "drain the reassembly queue\n");
 214         do {
 215                 spin_lock_irqsave(&info->reassembly_queue_lock, flags);
 216                 response = _get_first_reassembly(info);
 217                 if (response) {
 218                         list_del(&response->list);
 219                         spin_unlock_irqrestore(
 220                                 &info->reassembly_queue_lock, flags);
 221                         put_receive_buffer(info, response);
 222                 } else
 223                         spin_unlock_irqrestore(&info->reassembly_queue_lock, flags);
 224         } while (response);
 225
 226         info->reassembly_data_length = 0;
 227
 228         log_rdma_event(INFO, "free receive buffers\n");
 229         wait_event(info->wait_receive_queues,
 230                 info->count_receive_queue + info->count_empty_packet_queue
 231                         == info->receive_credit_max);
 232         destroy_receive_buffers(info);
 233
 234         ib_free_cq(info->send_cq);
 235         ib_free_cq(info->recv_cq);
 236         ib_dealloc_pd(info->pd);
 237         rdma_destroy_id(info->id);
 238
 239         /* free mempools */
 240         mempool_destroy(info->request_mempool);
 241         kmem_cache_destroy(info->request_cache);
 242
 243         mempool_destroy(info->response_mempool);
 244         kmem_cache_destroy(info->response_cache);
 245
 246         info->transport_status = SMBD_DESTROYED;
 247         wake_up_all(&info->wait_destroy);
 248 }
 249
 250 static int smbd_process_disconnected(struct smbd_connection *info)
 251 {
 252         schedule_work(&info->destroy_work);
 253         return 0;
 254 }
 255
 256 static void smbd_disconnect_rdma_work(struct work_struct *work)
 257 {
 258         struct smbd_connection *info =
 259                 container_of(work, struct smbd_connection, disconnect_work);
 260
 261         if (info->transport_status == SMBD_CONNECTED) {
 262                 info->transport_status = SMBD_DISCONNECTING;
 263                 rdma_disconnect(info->id);
 264         }
 265 }
 266
 267 static void smbd_disconnect_rdma_connection(struct smbd_connection *info)
 268 {
 269         queue_work(info->workqueue, &info->disconnect_work);
 270 }
 271
 272 /* Upcall from RDMA CM */
 273 static int smbd_conn_upcall(
 274                 struct rdma_cm_id *id, struct rdma_cm_event *event)
 275 {
 276         struct smbd_connection *info = id->context;
 277
 278         log_rdma_event(INFO, "event=%d status=%d\n",
 279                 event->event, event->status);
 280
 281         switch (event->event) {
 282         case RDMA_CM_EVENT_ADDR_RESOLVED:
 283         case RDMA_CM_EVENT_ROUTE_RESOLVED:
 284                 info->ri_rc = 0;
 285                 complete(&info->ri_done);
 286                 break;
 287
 288         case RDMA_CM_EVENT_ADDR_ERROR:
 289                 info->ri_rc = -EHOSTUNREACH;
 290                 complete(&info->ri_done);
 291                 break;
 292
 293         case RDMA_CM_EVENT_ROUTE_ERROR:
 294                 info->ri_rc = -ENETUNREACH;
 295                 complete(&info->ri_done);
 296                 break;
 297
 298         case RDMA_CM_EVENT_ESTABLISHED:
 299                 log_rdma_event(INFO, "connected event=%d\n", event->event);
 300                 info->transport_status = SMBD_CONNECTED;
 301                 wake_up_interruptible(&info->conn_wait);
 302                 break;
 303
 304         case RDMA_CM_EVENT_CONNECT_ERROR:
 305         case RDMA_CM_EVENT_UNREACHABLE:
 306         case RDMA_CM_EVENT_REJECTED:
 307                 log_rdma_event(INFO, "connecting failed event=%d\n", event->event);
 308                 info->transport_status = SMBD_DISCONNECTED;
 309                 wake_up_interruptible(&info->conn_wait);
 310                 break;
 311
 312         case RDMA_CM_EVENT_DEVICE_REMOVAL:
 313         case RDMA_CM_EVENT_DISCONNECTED:
 314                 /* This happenes when we fail the negotiation */
 315                 if (info->transport_status == SMBD_NEGOTIATE_FAILED) {
 316                         info->transport_status = SMBD_DISCONNECTED;
 317                         wake_up(&info->conn_wait);
 318                         break;
 319                 }
 320
 321                 info->transport_status = SMBD_DISCONNECTED;
 322                 smbd_process_disconnected(info);
 323                 break;
 324
 325         default:
 326                 break;
 327         }
 328
 329         return 0;
 330 }
 331
 332 /* Upcall from RDMA QP */
 333 static void
 334 smbd_qp_async_error_upcall(struct ib_event *event, void *context)
 335 {
 336         struct smbd_connection *info = context;
 337
 338         log_rdma_event(ERR, "%s on device %s info %p\n",
 339                 ib_event_msg(event->event), event->device->name, info);
 340
 341         switch (event->event) {
 342         case IB_EVENT_CQ_ERR:
 343         case IB_EVENT_QP_FATAL:
 344                 smbd_disconnect_rdma_connection(info);
 345
 346         default:
 347                 break;
 348         }
 349 }
 350
 351 static inline void *smbd_request_payload(struct smbd_request *request)
 352 {
 353         return (void *)request->packet;
 354 }
 355
 356 static inline void *smbd_response_payload(struct smbd_response *response)
 357 {
 358         return (void *)response->packet;
 359 }
 360
 361 /* Called when a RDMA send is done */
 362 static void send_done(struct ib_cq *cq, struct ib_wc *wc)
 363 {
 364         int i;
 365         struct smbd_request *request =
 366                 container_of(wc->wr_cqe, struct smbd_request, cqe);
 367
 368         log_rdma_send(INFO, "smbd_request %p completed wc->status=%d\n",
 369                 request, wc->status);
 370
 371         if (wc->status != IB_WC_SUCCESS || wc->opcode != IB_WC_SEND) {
 372                 log_rdma_send(ERR, "wc->status=%d wc->opcode=%d\n",
 373                         wc->status, wc->opcode);
 374                 smbd_disconnect_rdma_connection(request->info);
 375         }
 376
 377         for (i = 0; i < request->num_sge; i++)
 378                 ib_dma_unmap_single(request->info->id->device,
 379                         request->sge[i].addr,
 380                         request->sge[i].length,
 381                         DMA_TO_DEVICE);
 382
 383         if (request->has_payload) {
 384                 if (atomic_dec_and_test(&request->info->send_payload_pending))
 385                         wake_up(&request->info->wait_send_payload_pending);
 386         } else {
 387                 if (atomic_dec_and_test(&request->info->send_pending))
 388                         wake_up(&request->info->wait_send_pending);
 389         }
 390
 391         mempool_free(request, request->info->request_mempool);
 392 }
 393
 394 static void dump_smbd_negotiate_resp(struct smbd_negotiate_resp *resp)
 395 {
 396         log_rdma_event(INFO, "resp message min_version %u max_version %u "
 397                 "negotiated_version %u credits_requested %u "
 398                 "credits_granted %u status %u max_readwrite_size %u "
 399                 "preferred_send_size %u max_receive_size %u "
 400                 "max_fragmented_size %u\n",
 401                 resp->min_version, resp->max_version, resp->negotiated_version,
 402                 resp->credits_requested, resp->credits_granted, resp->status,
 403                 resp->max_readwrite_size, resp->preferred_send_size,
 404                 resp->max_receive_size, resp->max_fragmented_size);
 405 }
 406
 407 /*
 408  * Process a negotiation response message, according to [MS-SMBD]3.1.5.7
 409  * response, packet_length: the negotiation response message
 410  * return value: true if negotiation is a success, false if failed
 411  */
 412 static bool process_negotiation_response(
 413                 struct smbd_response *response, int packet_length)
 414 {
 415         struct smbd_connection *info = response->info;
 416         struct smbd_negotiate_resp *packet = smbd_response_payload(response);
 417
 418         if (packet_length < sizeof(struct smbd_negotiate_resp)) {
 419                 log_rdma_event(ERR,
 420                         "error: packet_length=%d\n", packet_length);
 421                 return false;
 422         }
 423
 424         if (le16_to_cpu(packet->negotiated_version) != SMBD_V1) {
 425                 log_rdma_event(ERR, "error: negotiated_version=%x\n",
 426                         le16_to_cpu(packet->negotiated_version));
 427                 return false;
 428         }
 429         info->protocol = le16_to_cpu(packet->negotiated_version);
 430
 431         if (packet->credits_requested == 0) {
 432                 log_rdma_event(ERR, "error: credits_requested==0\n");
 433                 return false;
 434         }
 435         info->receive_credit_target = le16_to_cpu(packet->credits_requested);
 436
 437         if (packet->credits_granted == 0) {
 438                 log_rdma_event(ERR, "error: credits_granted==0\n");
 439                 return false;
 440         }
 441         atomic_set(&info->send_credits, le16_to_cpu(packet->credits_granted));
 442
 443         atomic_set(&info->receive_credits, 0);
 444
 445         if (le32_to_cpu(packet->preferred_send_size) > info->max_receive_size) {
 446                 log_rdma_event(ERR, "error: preferred_send_size=%d\n",
 447                         le32_to_cpu(packet->preferred_send_size));
 448                 return false;
 449         }
 450         info->max_receive_size = le32_to_cpu(packet->preferred_send_size);
 451
 452         if (le32_to_cpu(packet->max_receive_size) < SMBD_MIN_RECEIVE_SIZE) {
 453                 log_rdma_event(ERR, "error: max_receive_size=%d\n",
 454                         le32_to_cpu(packet->max_receive_size));
 455                 return false;
 456         }
 457         info->max_send_size = min_t(int, info->max_send_size,
 458                                         le32_to_cpu(packet->max_receive_size));
 459
 460         if (le32_to_cpu(packet->max_fragmented_size) <
 461                         SMBD_MIN_FRAGMENTED_SIZE) {
 462                 log_rdma_event(ERR, "error: max_fragmented_size=%d\n",
 463                         le32_to_cpu(packet->max_fragmented_size));
 464                 return false;
 465         }
 466         info->max_fragmented_send_size =
 467                 le32_to_cpu(packet->max_fragmented_size);
 468         info->rdma_readwrite_threshold =
 469                 rdma_readwrite_threshold > info->max_fragmented_send_size ?
 470                 info->max_fragmented_send_size :
 471                 rdma_readwrite_threshold;
 472
 473
 474         info->max_readwrite_size = min_t(u32,
 475                         le32_to_cpu(packet->max_readwrite_size),
 476                         info->max_frmr_depth * PAGE_SIZE);
 477         info->max_frmr_depth = info->max_readwrite_size / PAGE_SIZE;
 478
 479         return true;
 480 }
 481
 482 /*
 483  * Check and schedule to send an immediate packet
 484  * This is used to extend credtis to remote peer to keep the transport busy
 485  */
 486 static void check_and_send_immediate(struct smbd_connection *info)
 487 {
 488         if (info->transport_status != SMBD_CONNECTED)
 489                 return;
 490
 491         info->send_immediate = true;
 492
 493         /*
 494          * Promptly send a packet if our peer is running low on receive
 495          * credits
 496          */
 497         if (atomic_read(&info->receive_credits) <
 498                 info->receive_credit_target - 1)
 499                 queue_delayed_work(
 500                         info->workqueue, &info->send_immediate_work, 0);
 501 }
 502
 503 static void smbd_post_send_credits(struct work_struct *work)
 504 {
 505         int ret = 0;
 506         int use_receive_queue = 1;
 507         int rc;
 508         struct smbd_response *response;
 509         struct smbd_connection *info =
 510                 container_of(work, struct smbd_connection,
 511                         post_send_credits_work);
 512
 513         if (info->transport_status != SMBD_CONNECTED) {
 514                 wake_up(&info->wait_receive_queues);
 515                 return;
 516         }
 517
 518         if (info->receive_credit_target >
 519                 atomic_read(&info->receive_credits)) {
 520                 while (true) {
 521                         if (use_receive_queue)
 522                                 response = get_receive_buffer(info);
 523                         else
 524                                 response = get_empty_queue_buffer(info);
 525                         if (!response) {
 526                                 /* now switch to emtpy packet queue */
 527                                 if (use_receive_queue) {
 528                                         use_receive_queue = 0;
 529                                         continue;
 530                                 } else
 531                                         break;
 532                         }
 533
 534                         response->type = SMBD_TRANSFER_DATA;
 535                         response->first_segment = false;
 536                         rc = smbd_post_recv(info, response);
 537                         if (rc) {
 538                                 log_rdma_recv(ERR,
 539                                         "post_recv failed rc=%d\n", rc);
 540                                 put_receive_buffer(info, response);
 541                                 break;
 542                         }
 543
 544                         ret++;
 545                 }
 546         }
 547
 548         spin_lock(&info->lock_new_credits_offered);
 549         info->new_credits_offered += ret;
 550         spin_unlock(&info->lock_new_credits_offered);
 551
 552         atomic_add(ret, &info->receive_credits);
 553
 554         /* Check if we can post new receive and grant credits to peer */
 555         check_and_send_immediate(info);
 556 }
 557
 558 static void smbd_recv_done_work(struct work_struct *work)
 559 {
 560         struct smbd_connection *info =
 561                 container_of(work, struct smbd_connection, recv_done_work);
 562
 563         /*
 564          * We may have new send credits granted from remote peer
 565          * If any sender is blcoked on lack of credets, unblock it
 566          */
 567         if (atomic_read(&info->send_credits))
 568                 wake_up_interruptible(&info->wait_send_queue);
 569
 570         /*
 571          * Check if we need to send something to remote peer to
 572          * grant more credits or respond to KEEP_ALIVE packet
 573          */
 574         check_and_send_immediate(info);
 575 }
 576
 577 /* Called from softirq, when recv is done */
 578 static void recv_done(struct ib_cq *cq, struct ib_wc *wc)
 579 {
 580         struct smbd_data_transfer *data_transfer;
 581         struct smbd_response *response =
 582                 container_of(wc->wr_cqe, struct smbd_response, cqe);
 583         struct smbd_connection *info = response->info;
 584         int data_length = 0;
 585
 586         log_rdma_recv(INFO, "response=%p type=%d wc status=%d wc opcode %d "
 587                       "byte_len=%d pkey_index=%x\n",
 588                 response, response->type, wc->status, wc->opcode,
 589                 wc->byte_len, wc->pkey_index);
 590
 591         if (wc->status != IB_WC_SUCCESS || wc->opcode != IB_WC_RECV) {
 592                 log_rdma_recv(INFO, "wc->status=%d opcode=%d\n",
 593                         wc->status, wc->opcode);
 594                 smbd_disconnect_rdma_connection(info);
 595                 goto error;
 596         }
 597
 598         ib_dma_sync_single_for_cpu(
 599                 wc->qp->device,
 600                 response->sge.addr,
 601                 response->sge.length,
 602                 DMA_FROM_DEVICE);
 603
 604         switch (response->type) {
 605         /* SMBD negotiation response */
 606         case SMBD_NEGOTIATE_RESP:
 607                 dump_smbd_negotiate_resp(smbd_response_payload(response));
 608                 info->full_packet_received = true;
 609                 info->negotiate_done =
 610                         process_negotiation_response(response, wc->byte_len);
 611                 complete(&info->negotiate_completion);
 612                 break;
 613
 614         /* SMBD data transfer packet */
 615         case SMBD_TRANSFER_DATA:
 616                 data_transfer = smbd_response_payload(response);
 617                 data_length = le32_to_cpu(data_transfer->data_length);
 618
 619                 /*
 620                  * If this is a packet with data playload place the data in
 621                  * reassembly queue and wake up the reading thread
 622                  */
 623                 if (data_length) {
 624                         if (info->full_packet_received)
 625                                 response->first_segment = true;
 626
 627                         if (le32_to_cpu(data_transfer->remaining_data_length))
 628                                 info->full_packet_received = false;
 629                         else
 630                                 info->full_packet_received = true;
 631
 632                         enqueue_reassembly(
 633                                 info,
 634                                 response,
 635                                 data_length);
 636                 } else
 637                         put_empty_packet(info, response);
 638
 639                 if (data_length)
 640                         wake_up_interruptible(&info->wait_reassembly_queue);
 641
 642                 atomic_dec(&info->receive_credits);
 643                 info->receive_credit_target =
 644                         le16_to_cpu(data_transfer->credits_requested);
 645                 atomic_add(le16_to_cpu(data_transfer->credits_granted),
 646                         &info->send_credits);
 647
 648                 log_incoming(INFO, "data flags %d data_offset %d "
 649                         "data_length %d remaining_data_length %d\n",
 650                         le16_to_cpu(data_transfer->flags),
 651                         le32_to_cpu(data_transfer->data_offset),
 652                         le32_to_cpu(data_transfer->data_length),
 653                         le32_to_cpu(data_transfer->remaining_data_length));
 654
 655                 /* Send a KEEP_ALIVE response right away if requested */
 656                 info->keep_alive_requested = KEEP_ALIVE_NONE;
 657                 if (le16_to_cpu(data_transfer->flags) &
 658                                 SMB_DIRECT_RESPONSE_REQUESTED) {
 659                         info->keep_alive_requested = KEEP_ALIVE_PENDING;
 660                 }
 661
 662                 queue_work(info->workqueue, &info->recv_done_work);
 663                 return;
 664
 665         default:
 666                 log_rdma_recv(ERR,
 667                         "unexpected response type=%d\n", response->type);
 668         }
 669
 670 error:
 671         put_receive_buffer(info, response);
 672 }
 673
 674 static struct rdma_cm_id *smbd_create_id(
 675                 struct smbd_connection *info,
 676                 struct sockaddr *dstaddr, int port)
 677 {
 678         struct rdma_cm_id *id;
 679         int rc;
 680         __be16 *sport;
 681
 682         id = rdma_create_id(&init_net, smbd_conn_upcall, info,
 683                 RDMA_PS_TCP, IB_QPT_RC);
 684         if (IS_ERR(id)) {
 685                 rc = PTR_ERR(id);
 686                 log_rdma_event(ERR, "rdma_create_id() failed %i\n", rc);
 687                 return id;
 688         }
 689
 690         if (dstaddr->sa_family == AF_INET6)
 691                 sport = &((struct sockaddr_in6 *)dstaddr)->sin6_port;
 692         else
 693                 sport = &((struct sockaddr_in *)dstaddr)->sin_port;
 694
 695         *sport = htons(port);
 696
 697         init_completion(&info->ri_done);
 698         info->ri_rc = -ETIMEDOUT;
 699
 700         rc = rdma_resolve_addr(id, NULL, (struct sockaddr *)dstaddr,
 701                 RDMA_RESOLVE_TIMEOUT);
 702         if (rc) {
 703                 log_rdma_event(ERR, "rdma_resolve_addr() failed %i\n", rc);
 704                 goto out;
 705         }
 706         wait_for_completion_interruptible_timeout(
 707                 &info->ri_done, msecs_to_jiffies(RDMA_RESOLVE_TIMEOUT));
 708         rc = info->ri_rc;
 709         if (rc) {
 710                 log_rdma_event(ERR, "rdma_resolve_addr() completed %i\n", rc);
 711                 goto out;
 712         }
 713
 714         info->ri_rc = -ETIMEDOUT;
 715         rc = rdma_resolve_route(id, RDMA_RESOLVE_TIMEOUT);
 716         if (rc) {
 717                 log_rdma_event(ERR, "rdma_resolve_route() failed %i\n", rc);
 718                 goto out;
 719         }
 720         wait_for_completion_interruptible_timeout(
 721                 &info->ri_done, msecs_to_jiffies(RDMA_RESOLVE_TIMEOUT));
 722         rc = info->ri_rc;
 723         if (rc) {
 724                 log_rdma_event(ERR, "rdma_resolve_route() completed %i\n", rc);
 725                 goto out;
 726         }
 727
 728         return id;
 729
 730 out:
 731         rdma_destroy_id(id);
 732         return ERR_PTR(rc);
 733 }
 734
 735 /*
 736  * Test if FRWR (Fast Registration Work Requests) is supported on the device
 737  * This implementation requries FRWR on RDMA read/write
 738  * return value: true if it is supported
 739  */
 740 static bool frwr_is_supported(struct ib_device_attr *attrs)
 741 {
 742         if (!(attrs->device_cap_flags & IB_DEVICE_MEM_MGT_EXTENSIONS))
 743                 return false;
 744         if (attrs->max_fast_reg_page_list_len == 0)
 745                 return false;
 746         return true;
 747 }
 748
 749 static int smbd_ia_open(
 750                 struct smbd_connection *info,
 751                 struct sockaddr *dstaddr, int port)
 752 {
 753         int rc;
 754
 755         info->id = smbd_create_id(info, dstaddr, port);
 756         if (IS_ERR(info->id)) {
 757                 rc = PTR_ERR(info->id);
 758                 goto out1;
 759         }
 760
 761         if (!frwr_is_supported(&info->id->device->attrs)) {
 762                 log_rdma_event(ERR,
 763                         "Fast Registration Work Requests "
 764                         "(FRWR) is not supported\n");
 765                 log_rdma_event(ERR,
 766                         "Device capability flags = %llx "
 767                         "max_fast_reg_page_list_len = %u\n",
 768                         info->id->device->attrs.device_cap_flags,
 769                         info->id->device->attrs.max_fast_reg_page_list_len);
 770                 rc = -EPROTONOSUPPORT;
 771                 goto out2;
 772         }
 773         info->max_frmr_depth = min_t(int,
 774                 smbd_max_frmr_depth,
 775                 info->id->device->attrs.max_fast_reg_page_list_len);
 776         info->mr_type = IB_MR_TYPE_MEM_REG;
 777         if (info->id->device->attrs.device_cap_flags & IB_DEVICE_SG_GAPS_REG)
 778                 info->mr_type = IB_MR_TYPE_SG_GAPS;
 779
 780         info->pd = ib_alloc_pd(info->id->device, 0);
 781         if (IS_ERR(info->pd)) {
 782                 rc = PTR_ERR(info->pd);
 783                 log_rdma_event(ERR, "ib_alloc_pd() returned %d\n", rc);
 784                 goto out2;
 785         }
 786
 787         return 0;
 788
 789 out2:
 790         rdma_destroy_id(info->id);
 791         info->id = NULL;
 792
 793 out1:
 794         return rc;
 795 }
 796
 797 /*
 798  * Send a negotiation request message to the peer
 799  * The negotiation procedure is in [MS-SMBD] 3.1.5.2 and 3.1.5.3
 800  * After negotiation, the transport is connected and ready for
 801  * carrying upper layer SMB payload
 802  */
 803 static int smbd_post_send_negotiate_req(struct smbd_connection *info)
 804 {
 805         struct ib_send_wr send_wr;
 806         int rc = -ENOMEM;
 807         struct smbd_request *request;
 808         struct smbd_negotiate_req *packet;
 809
 810         request = mempool_alloc(info->request_mempool, GFP_KERNEL);
 811         if (!request)
 812                 return rc;
 813
 814         request->info = info;
 815
 816         packet = smbd_request_payload(request);
 817         packet->min_version = cpu_to_le16(SMBD_V1);
 818         packet->max_version = cpu_to_le16(SMBD_V1);
 819         packet->reserved = 0;
 820         packet->credits_requested = cpu_to_le16(info->send_credit_target);
 821         packet->preferred_send_size = cpu_to_le32(info->max_send_size);
 822         packet->max_receive_size = cpu_to_le32(info->max_receive_size);
 823         packet->max_fragmented_size =
 824                 cpu_to_le32(info->max_fragmented_recv_size);
 825
 826         request->num_sge = 1;
 827         request->sge[0].addr = ib_dma_map_single(
 828                                 info->id->device, (void *)packet,
 829                                 sizeof(*packet), DMA_TO_DEVICE);
 830         if (ib_dma_mapping_error(info->id->device, request->sge[0].addr)) {
 831                 rc = -EIO;
 832                 goto dma_mapping_failed;
 833         }
 834
 835         request->sge[0].length = sizeof(*packet);
 836         request->sge[0].lkey = info->pd->local_dma_lkey;
 837
 838         ib_dma_sync_single_for_device(
 839                 info->id->device, request->sge[0].addr,
 840                 request->sge[0].length, DMA_TO_DEVICE);
 841
 842         request->cqe.done = send_done;
 843
 844         send_wr.next = NULL;
 845         send_wr.wr_cqe = &request->cqe;
 846         send_wr.sg_list = request->sge;
 847         send_wr.num_sge = request->num_sge;
 848         send_wr.opcode = IB_WR_SEND;
 849         send_wr.send_flags = IB_SEND_SIGNALED;
 850
 851         log_rdma_send(INFO, "sge addr=%llx length=%x lkey=%x\n",
 852                 request->sge[0].addr,
 853                 request->sge[0].length, request->sge[0].lkey);
 854
 855         request->has_payload = false;
 856         atomic_inc(&info->send_pending);
 857         rc = ib_post_send(info->id->qp, &send_wr, NULL);
 858         if (!rc)
 859                 return 0;
 860
 861         /* if we reach here, post send failed */
 862         log_rdma_send(ERR, "ib_post_send failed rc=%d\n", rc);
 863         atomic_dec(&info->send_pending);
 864         ib_dma_unmap_single(info->id->device, request->sge[0].addr,
 865                 request->sge[0].length, DMA_TO_DEVICE);
 866
 867         smbd_disconnect_rdma_connection(info);
 868
 869 dma_mapping_failed:
 870         mempool_free(request, info->request_mempool);
 871         return rc;
 872 }
 873
 874 /*
 875  * Extend the credits to remote peer
 876  * This implements [MS-SMBD] 3.1.5.9
 877  * The idea is that we should extend credits to remote peer as quickly as
 878  * it's allowed, to maintain data flow. We allocate as much receive
 879  * buffer as possible, and extend the receive credits to remote peer
 880  * return value: the new credtis being granted.
 881  */
 882 static int manage_credits_prior_sending(struct smbd_connection *info)
 883 {
 884         int new_credits;
 885
 886         spin_lock(&info->lock_new_credits_offered);
 887         new_credits = info->new_credits_offered;
 888         info->new_credits_offered = 0;
 889         spin_unlock(&info->lock_new_credits_offered);
 890
 891         return new_credits;
 892 }
 893
 894 /*
 895  * Check if we need to send a KEEP_ALIVE message
 896  * The idle connection timer triggers a KEEP_ALIVE message when expires
 897  * SMB_DIRECT_RESPONSE_REQUESTED is set in the message flag to have peer send
 898  * back a response.
 899  * return value:
 900  * 1 if SMB_DIRECT_RESPONSE_REQUESTED needs to be set
 901  * 0: otherwise
 902  */
 903 static int manage_keep_alive_before_sending(struct smbd_connection *info)
 904 {
 905         if (info->keep_alive_requested == KEEP_ALIVE_PENDING) {
 906                 info->keep_alive_requested = KEEP_ALIVE_SENT;
 907                 return 1;
 908         }
 909         return 0;
 910 }
 911
 912 /*
 913  * Build and prepare the SMBD packet header
 914  * This function waits for avaialbe send credits and build a SMBD packet
 915  * header. The caller then optional append payload to the packet after
 916  * the header
 917  * intput values
 918  * size: the size of the payload
 919  * remaining_data_length: remaining data to send if this is part of a
 920  * fragmented packet
 921  * output values
 922  * request_out: the request allocated from this function
 923  * return values: 0 on success, otherwise actual error code returned
 924  */
 925 static int smbd_create_header(struct smbd_connection *info,
 926                 int size, int remaining_data_length,
 927                 struct smbd_request **request_out)
 928 {
 929         struct smbd_request *request;
 930         struct smbd_data_transfer *packet;
 931         int header_length;
 932         int rc;
 933
 934         /* Wait for send credits. A SMBD packet needs one credit */
 935         rc = wait_event_interruptible(info->wait_send_queue,
 936                 atomic_read(&info->send_credits) > 0 ||
 937                 info->transport_status != SMBD_CONNECTED);
 938         if (rc)
 939                 return rc;
 940
 941         if (info->transport_status != SMBD_CONNECTED) {
 942                 log_outgoing(ERR, "disconnected not sending\n");
 943                 return -ENOENT;
 944         }
 945         atomic_dec(&info->send_credits);
 946
 947         request = mempool_alloc(info->request_mempool, GFP_KERNEL);
 948         if (!request) {
 949                 rc = -ENOMEM;
 950                 goto err;
 951         }
 952
 953         request->info = info;
 954
 955         /* Fill in the packet header */
 956         packet = smbd_request_payload(request);
 957         packet->credits_requested = cpu_to_le16(info->send_credit_target);
 958         packet->credits_granted =
 959                 cpu_to_le16(manage_credits_prior_sending(info));
 960         info->send_immediate = false;
 961
 962         packet->flags = 0;
 963         if (manage_keep_alive_before_sending(info))
 964                 packet->flags |= cpu_to_le16(SMB_DIRECT_RESPONSE_REQUESTED);
 965
 966         packet->reserved = 0;
 967         if (!size)
 968                 packet->data_offset = 0;
 969         else
 970                 packet->data_offset = cpu_to_le32(24);
 971         packet->data_length = cpu_to_le32(size);
 972         packet->remaining_data_length = cpu_to_le32(remaining_data_length);
 973         packet->padding = 0;
 974
 975         log_outgoing(INFO, "credits_requested=%d credits_granted=%d "
 976                 "data_offset=%d data_length=%d remaining_data_length=%d\n",
 977                 le16_to_cpu(packet->credits_requested),
 978                 le16_to_cpu(packet->credits_granted),
 979                 le32_to_cpu(packet->data_offset),
 980                 le32_to_cpu(packet->data_length),
 981                 le32_to_cpu(packet->remaining_data_length));
 982
 983         /* Map the packet to DMA */
 984         header_length = sizeof(struct smbd_data_transfer);
 985         /* If this is a packet without payload, don't send padding */
 986         if (!size)
 987                 header_length = offsetof(struct smbd_data_transfer, padding);
 988
 989         request->num_sge = 1;
 990         request->sge[0].addr = ib_dma_map_single(info->id->device,
 991                                                  (void *)packet,
 992                                                  header_length,
 993                                                  DMA_BIDIRECTIONAL);
 994         if (ib_dma_mapping_error(info->id->device, request->sge[0].addr)) {
 995                 mempool_free(request, info->request_mempool);
 996                 rc = -EIO;
 997                 goto err;
 998         }
 999
1000         request->sge[0].length = header_length;
1001         request->sge[0].lkey = info->pd->local_dma_lkey;
1002
1003         *request_out = request;
1004         return 0;
1005
1006 err:
1007         atomic_inc(&info->send_credits);
1008         return rc;
1009 }
1010
1011 static void smbd_destroy_header(struct smbd_connection *info,
1012                 struct smbd_request *request)
1013 {
1014
1015         ib_dma_unmap_single(info->id->device,
1016                             request->sge[0].addr,
1017                             request->sge[0].length,
1018                             DMA_TO_DEVICE);
1019         mempool_free(request, info->request_mempool);
1020         atomic_inc(&info->send_credits);
1021 }
1022
1023 /* Post the send request */
1024 static int smbd_post_send(struct smbd_connection *info,
1025                 struct smbd_request *request, bool has_payload)
1026 {
1027         struct ib_send_wr send_wr;
1028         int rc, i;
1029
1030         for (i = 0; i < request->num_sge; i++) {
1031                 log_rdma_send(INFO,
1032                         "rdma_request sge[%d] addr=%llu length=%u\n",
1033                         i, request->sge[i].addr, request->sge[i].length);
1034                 ib_dma_sync_single_for_device(
1035                         info->id->device,
1036                         request->sge[i].addr,
1037                         request->sge[i].length,
1038                         DMA_TO_DEVICE);
1039         }
1040
1041         request->cqe.done = send_done;
1042
1043         send_wr.next = NULL;
1044         send_wr.wr_cqe = &request->cqe;
1045         send_wr.sg_list = request->sge;
1046         send_wr.num_sge = request->num_sge;
1047         send_wr.opcode = IB_WR_SEND;
1048         send_wr.send_flags = IB_SEND_SIGNALED;
1049
1050         if (has_payload) {
1051                 request->has_payload = true;
1052                 atomic_inc(&info->send_payload_pending);
1053         } else {
1054                 request->has_payload = false;
1055                 atomic_inc(&info->send_pending);
1056         }
1057
1058         rc = ib_post_send(info->id->qp, &send_wr, NULL);
1059         if (rc) {
1060                 log_rdma_send(ERR, "ib_post_send failed rc=%d\n", rc);
1061                 if (has_payload) {
1062                         if (atomic_dec_and_test(&info->send_payload_pending))
1063                                 wake_up(&info->wait_send_payload_pending);
1064                 } else {
1065                         if (atomic_dec_and_test(&info->send_pending))
1066                                 wake_up(&info->wait_send_pending);
1067                 }
1068                 smbd_disconnect_rdma_connection(info);
1069         } else
1070                 /* Reset timer for idle connection after packet is sent */
1071                 mod_delayed_work(info->workqueue, &info->idle_timer_work,
1072                         info->keep_alive_interval*HZ);
1073
1074         return rc;
1075 }
1076
1077 static int smbd_post_send_sgl(struct smbd_connection *info,
1078         struct scatterlist *sgl, int data_length, int remaining_data_length)
1079 {
1080         int num_sgs;
1081         int i, rc;
1082         struct smbd_request *request;
1083         struct scatterlist *sg;
1084
1085         rc = smbd_create_header(
1086                 info, data_length, remaining_data_length, &request);
1087         if (rc)
1088                 return rc;
1089
1090         num_sgs = sgl ? sg_nents(sgl) : 0;
1091         for_each_sg(sgl, sg, num_sgs, i) {
1092                 request->sge[i+1].addr =
1093                         ib_dma_map_page(info->id->device, sg_page(sg),
1094                                sg->offset, sg->length, DMA_BIDIRECTIONAL);
1095                 if (ib_dma_mapping_error(
1096                                 info->id->device, request->sge[i+1].addr)) {
1097                         rc = -EIO;
1098                         request->sge[i+1].addr = 0;
1099                         goto dma_mapping_failure;
1100                 }
1101                 request->sge[i+1].length = sg->length;
1102                 request->sge[i+1].lkey = info->pd->local_dma_lkey;
1103                 request->num_sge++;
1104         }
1105
1106         rc = smbd_post_send(info, request, data_length);
1107         if (!rc)
1108                 return 0;
1109
1110 dma_mapping_failure:
1111         for (i = 1; i < request->num_sge; i++)
1112                 if (request->sge[i].addr)
1113                         ib_dma_unmap_single(info->id->device,
1114                                             request->sge[i].addr,
1115                                             request->sge[i].length,
1116                                             DMA_TO_DEVICE);
1117         smbd_destroy_header(info, request);
1118         return rc;
1119 }
1120
1121 /*
1122  * Send a page
1123  * page: the page to send
1124  * offset: offset in the page to send
1125  * size: length in the page to send
1126  * remaining_data_length: remaining data to send in this payload
1127  */
1128 static int smbd_post_send_page(struct smbd_connection *info, struct page *page,
1129                 unsigned long offset, size_t size, int remaining_data_length)
1130 {
1131         struct scatterlist sgl;
1132
1133         sg_init_table(&sgl, 1);
1134         sg_set_page(&sgl, page, size, offset);
1135
1136         return smbd_post_send_sgl(info, &sgl, size, remaining_data_length);
1137 }
1138
1139 /*
1140  * Send an empty message
1141  * Empty message is used to extend credits to peer to for keep live
1142  * while there is no upper layer payload to send at the time
1143  */
1144 static int smbd_post_send_empty(struct smbd_connection *info)
1145 {
1146         info->count_send_empty++;
1147         return smbd_post_send_sgl(info, NULL, 0, 0);
1148 }
1149
1150 /*
1151  * Send a data buffer
1152  * iov: the iov array describing the data buffers
1153  * n_vec: number of iov array
1154  * remaining_data_length: remaining data to send following this packet
1155  * in segmented SMBD packet
1156  */
1157 static int smbd_post_send_data(
1158         struct smbd_connection *info, struct kvec *iov, int n_vec,
1159         int remaining_data_length)
1160 {
1161         int i;
1162         u32 data_length = 0;
1163         struct scatterlist sgl[SMBDIRECT_MAX_SGE];
1164
1165         if (n_vec > SMBDIRECT_MAX_SGE) {
1166                 cifs_dbg(VFS, "Can't fit data to SGL, n_vec=%d\n", n_vec);
1167                 return -ENOMEM;
1168         }
1169
1170         sg_init_table(sgl, n_vec);
1171         for (i = 0; i < n_vec; i++) {
1172                 data_length += iov[i].iov_len;
1173                 sg_set_buf(&sgl[i], iov[i].iov_base, iov[i].iov_len);
1174         }
1175
1176         return smbd_post_send_sgl(info, sgl, data_length, remaining_data_length);
1177 }
1178
1179 /*
1180  * Post a receive request to the transport
1181  * The remote peer can only send data when a receive request is posted
1182  * The interaction is controlled by send/receive credit system
1183  */
1184 static int smbd_post_recv(
1185                 struct smbd_connection *info, struct smbd_response *response)
1186 {
1187         struct ib_recv_wr recv_wr;
1188         int rc = -EIO;
1189
1190         response->sge.addr = ib_dma_map_single(
1191                                 info->id->device, response->packet,
1192                                 info->max_receive_size, DMA_FROM_DEVICE);
1193         if (ib_dma_mapping_error(info->id->device, response->sge.addr))
1194                 return rc;
1195
1196         response->sge.length = info->max_receive_size;
1197         response->sge.lkey = info->pd->local_dma_lkey;
1198
1199         response->cqe.done = recv_done;
1200
1201         recv_wr.wr_cqe = &response->cqe;
1202         recv_wr.next = NULL;
1203         recv_wr.sg_list = &response->sge;
1204         recv_wr.num_sge = 1;
1205
1206         rc = ib_post_recv(info->id->qp, &recv_wr, NULL);
1207         if (rc) {
1208                 ib_dma_unmap_single(info->id->device, response->sge.addr,
1209                                     response->sge.length, DMA_FROM_DEVICE);
1210                 smbd_disconnect_rdma_connection(info);
1211                 log_rdma_recv(ERR, "ib_post_recv failed rc=%d\n", rc);
1212         }
1213
1214         return rc;
1215 }
1216
1217 /* Perform SMBD negotiate according to [MS-SMBD] 3.1.5.2 */
1218 static int smbd_negotiate(struct smbd_connection *info)
1219 {
1220         int rc;
1221         struct smbd_response *response = get_receive_buffer(info);
1222
1223         response->type = SMBD_NEGOTIATE_RESP;
1224         rc = smbd_post_recv(info, response);
1225         log_rdma_event(INFO,
1226                 "smbd_post_recv rc=%d iov.addr=%llx iov.length=%x "
1227                 "iov.lkey=%x\n",
1228                 rc, response->sge.addr,
1229                 response->sge.length, response->sge.lkey);
1230         if (rc)
1231                 return rc;
1232
1233         init_completion(&info->negotiate_completion);
1234         info->negotiate_done = false;
1235         rc = smbd_post_send_negotiate_req(info);
1236         if (rc)
1237                 return rc;
1238
1239         rc = wait_for_completion_interruptible_timeout(
1240                 &info->negotiate_completion, SMBD_NEGOTIATE_TIMEOUT * HZ);
1241         log_rdma_event(INFO, "wait_for_completion_timeout rc=%d\n", rc);
1242
1243         if (info->negotiate_done)
1244                 return 0;
1245
1246         if (rc == 0)
1247                 rc = -ETIMEDOUT;
1248         else if (rc == -ERESTARTSYS)
1249                 rc = -EINTR;
1250         else
1251                 rc = -ENOTCONN;
1252
1253         return rc;
1254 }
1255
1256 static void put_empty_packet(
1257                 struct smbd_connection *info, struct smbd_response *response)
1258 {
1259         spin_lock(&info->empty_packet_queue_lock);
1260         list_add_tail(&response->list, &info->empty_packet_queue);
1261         info->count_empty_packet_queue++;
1262         spin_unlock(&info->empty_packet_queue_lock);
1263
1264         queue_work(info->workqueue, &info->post_send_credits_work);
1265 }
1266
1267 /*
1268  * Implement Connection.FragmentReassemblyBuffer defined in [MS-SMBD] 3.1.1.1
1269  * This is a queue for reassembling upper layer payload and present to upper
1270  * layer. All the inncoming payload go to the reassembly queue, regardless of
1271  * if reassembly is required. The uuper layer code reads from the queue for all
1272  * incoming payloads.
1273  * Put a received packet to the reassembly queue
1274  * response: the packet received
1275  * data_length: the size of payload in this packet
1276  */
1277 static void enqueue_reassembly(
1278         struct smbd_connection *info,
1279         struct smbd_response *response,
1280         int data_length)
1281 {
1282         spin_lock(&info->reassembly_queue_lock);
1283         list_add_tail(&response->list, &info->reassembly_queue);
1284         info->reassembly_queue_length++;
1285         /*
1286          * Make sure reassembly_data_length is updated after list and
1287          * reassembly_queue_length are updated. On the dequeue side
1288          * reassembly_data_length is checked without a lock to determine
1289          * if reassembly_queue_length and list is up to date
1290          */
1291         virt_wmb();
1292         info->reassembly_data_length += data_length;
1293         spin_unlock(&info->reassembly_queue_lock);
1294         info->count_reassembly_queue++;
1295         info->count_enqueue_reassembly_queue++;
1296 }
1297
1298 /*
1299  * Get the first entry at the front of reassembly queue
1300  * Caller is responsible for locking
1301  * return value: the first entry if any, NULL if queue is empty
1302  */
1303 static struct smbd_response *_get_first_reassembly(struct smbd_connection *info)
1304 {
1305         struct smbd_response *ret = NULL;
1306
1307         if (!list_empty(&info->reassembly_queue)) {
1308                 ret = list_first_entry(
1309                         &info->reassembly_queue,
1310                         struct smbd_response, list);
1311         }
1312         return ret;
1313 }
1314
1315 static struct smbd_response *get_empty_queue_buffer(
1316                 struct smbd_connection *info)
1317 {
1318         struct smbd_response *ret = NULL;
1319         unsigned long flags;
1320
1321         spin_lock_irqsave(&info->empty_packet_queue_lock, flags);
1322         if (!list_empty(&info->empty_packet_queue)) {
1323                 ret = list_first_entry(
1324                         &info->empty_packet_queue,
1325                         struct smbd_response, list);
1326                 list_del(&ret->list);
1327                 info->count_empty_packet_queue--;
1328         }
1329         spin_unlock_irqrestore(&info->empty_packet_queue_lock, flags);
1330
1331         return ret;
1332 }
1333
1334 /*
1335  * Get a receive buffer
1336  * For each remote send, we need to post a receive. The receive buffers are
1337  * pre-allocated in advance.
1338  * return value: the receive buffer, NULL if none is available
1339  */
1340 static struct smbd_response *get_receive_buffer(struct smbd_connection *info)
1341 {
1342         struct smbd_response *ret = NULL;
1343         unsigned long flags;
1344
1345         spin_lock_irqsave(&info->receive_queue_lock, flags);
1346         if (!list_empty(&info->receive_queue)) {
1347                 ret = list_first_entry(
1348                         &info->receive_queue,
1349                         struct smbd_response, list);
1350                 list_del(&ret->list);
1351                 info->count_receive_queue--;
1352                 info->count_get_receive_buffer++;
1353         }
1354         spin_unlock_irqrestore(&info->receive_queue_lock, flags);
1355
1356         return ret;
1357 }
1358
1359 /*
1360  * Return a receive buffer
1361  * Upon returning of a receive buffer, we can post new receive and extend
1362  * more receive credits to remote peer. This is done immediately after a
1363  * receive buffer is returned.
1364  */
1365 static void put_receive_buffer(
1366         struct smbd_connection *info, struct smbd_response *response)
1367 {
1368         unsigned long flags;
1369
1370         ib_dma_unmap_single(info->id->device, response->sge.addr,
1371                 response->sge.length, DMA_FROM_DEVICE);
1372
1373         spin_lock_irqsave(&info->receive_queue_lock, flags);
1374         list_add_tail(&response->list, &info->receive_queue);
1375         info->count_receive_queue++;
1376         info->count_put_receive_buffer++;
1377         spin_unlock_irqrestore(&info->receive_queue_lock, flags);
1378
1379         queue_work(info->workqueue, &info->post_send_credits_work);
1380 }
1381
1382 /* Preallocate all receive buffer on transport establishment */
1383 static int allocate_receive_buffers(struct smbd_connection *info, int num_buf)
1384 {
1385         int i;
1386         struct smbd_response *response;
1387
1388         INIT_LIST_HEAD(&info->reassembly_queue);
1389         spin_lock_init(&info->reassembly_queue_lock);
1390         info->reassembly_data_length = 0;
1391         info->reassembly_queue_length = 0;
1392
1393         INIT_LIST_HEAD(&info->receive_queue);
1394         spin_lock_init(&info->receive_queue_lock);
1395         info->count_receive_queue = 0;
1396
1397         INIT_LIST_HEAD(&info->empty_packet_queue);
1398         spin_lock_init(&info->empty_packet_queue_lock);
1399         info->count_empty_packet_queue = 0;
1400
1401         init_waitqueue_head(&info->wait_receive_queues);
1402
1403         for (i = 0; i < num_buf; i++) {
1404                 response = mempool_alloc(info->response_mempool, GFP_KERNEL);
1405                 if (!response)
1406                         goto allocate_failed;
1407
1408                 response->info = info;
1409                 list_add_tail(&response->list, &info->receive_queue);
1410                 info->count_receive_queue++;
1411         }
1412
1413         return 0;
1414
1415 allocate_failed:
1416         while (!list_empty(&info->receive_queue)) {
1417                 response = list_first_entry(
1418                                 &info->receive_queue,
1419                                 struct smbd_response, list);
1420                 list_del(&response->list);
1421                 info->count_receive_queue--;
1422
1423                 mempool_free(response, info->response_mempool);
1424         }
1425         return -ENOMEM;
1426 }
1427
1428 static void destroy_receive_buffers(struct smbd_connection *info)
1429 {
1430         struct smbd_response *response;
1431
1432         while ((response = get_receive_buffer(info)))
1433                 mempool_free(response, info->response_mempool);
1434
1435         while ((response = get_empty_queue_buffer(info)))
1436                 mempool_free(response, info->response_mempool);
1437 }
1438
1439 /*
1440  * Check and send an immediate or keep alive packet
1441  * The condition to send those packets are defined in [MS-SMBD] 3.1.1.1
1442  * Connection.KeepaliveRequested and Connection.SendImmediate
1443  * The idea is to extend credits to server as soon as it becomes available
1444  */
1445 static void send_immediate_work(struct work_struct *work)
1446 {
1447         struct smbd_connection *info = container_of(
1448                                         work, struct smbd_connection,
1449                                         send_immediate_work.work);
1450
1451         if (info->keep_alive_requested == KEEP_ALIVE_PENDING ||
1452             info->send_immediate) {
1453                 log_keep_alive(INFO, "send an empty message\n");
1454                 smbd_post_send_empty(info);
1455         }
1456 }
1457
1458 /* Implement idle connection timer [MS-SMBD] 3.1.6.2 */
1459 static void idle_connection_timer(struct work_struct *work)
1460 {
1461         struct smbd_connection *info = container_of(
1462                                         work, struct smbd_connection,
1463                                         idle_timer_work.work);
1464
1465         if (info->keep_alive_requested != KEEP_ALIVE_NONE) {
1466                 log_keep_alive(ERR,
1467                         "error status info->keep_alive_requested=%d\n",
1468                         info->keep_alive_requested);
1469                 smbd_disconnect_rdma_connection(info);
1470                 return;
1471         }
1472
1473         log_keep_alive(INFO, "about to send an empty idle message\n");
1474         smbd_post_send_empty(info);
1475
1476         /* Setup the next idle timeout work */
1477         queue_delayed_work(info->workqueue, &info->idle_timer_work,
1478                         info->keep_alive_interval*HZ);
1479 }
1480
1481 /* Destroy this SMBD connection, called from upper layer */
1482 void smbd_destroy(struct smbd_connection *info)
1483 {
1484         log_rdma_event(INFO, "destroying rdma session\n");
1485
1486         /* Kick off the disconnection process */
1487         smbd_disconnect_rdma_connection(info);
1488
1489         log_rdma_event(INFO, "wait for transport being destroyed\n");
1490         wait_event(info->wait_destroy,
1491                 info->transport_status == SMBD_DESTROYED);
1492
1493         destroy_workqueue(info->workqueue);
1494         kfree(info);
1495 }
1496
1497 /*
1498  * Reconnect this SMBD connection, called from upper layer
1499  * return value: 0 on success, or actual error code
1500  */
1501 int smbd_reconnect(struct TCP_Server_Info *server)
1502 {
1503         log_rdma_event(INFO, "reconnecting rdma session\n");
1504
1505         if (!server->smbd_conn) {
1506                 log_rdma_event(INFO, "rdma session already destroyed\n");
1507                 goto create_conn;
1508         }
1509
1510         /*
1511          * This is possible if transport is disconnected and we haven't received
1512          * notification from RDMA, but upper layer has detected timeout
1513          */
1514         if (server->smbd_conn->transport_status == SMBD_CONNECTED) {
1515                 log_rdma_event(INFO, "disconnecting transport\n");
1516                 smbd_disconnect_rdma_connection(server->smbd_conn);
1517         }
1518
1519         /* wait until the transport is destroyed */
1520         if (!wait_event_timeout(server->smbd_conn->wait_destroy,
1521                 server->smbd_conn->transport_status == SMBD_DESTROYED, 5*HZ))
1522                 return -EAGAIN;
1523
1524         destroy_workqueue(server->smbd_conn->workqueue);
1525         kfree(server->smbd_conn);
1526
1527 create_conn:
1528         log_rdma_event(INFO, "creating rdma session\n");
1529         server->smbd_conn = smbd_get_connection(
1530                 server, (struct sockaddr *) &server->dstaddr);
1531         log_rdma_event(INFO, "created rdma session info=%p\n",
1532                 server->smbd_conn);
1533
1534         return server->smbd_conn ? 0 : -ENOENT;
1535 }
1536
1537 static void destroy_caches_and_workqueue(struct smbd_connection *info)
1538 {
1539         destroy_receive_buffers(info);
1540         destroy_workqueue(info->workqueue);
1541         mempool_destroy(info->response_mempool);
1542         kmem_cache_destroy(info->response_cache);
1543         mempool_destroy(info->request_mempool);
1544         kmem_cache_destroy(info->request_cache);
1545 }
1546
1547 #define MAX_NAME_LEN    80
1548 static int allocate_caches_and_workqueue(struct smbd_connection *info)
1549 {
1550         char name[MAX_NAME_LEN];
1551         int rc;
1552
1553         snprintf(name, MAX_NAME_LEN, "smbd_request_%p", info);
1554         info->request_cache =
1555                 kmem_cache_create(
1556                         name,
1557                         sizeof(struct smbd_request) +
1558                                 sizeof(struct smbd_data_transfer),
1559                         0, SLAB_HWCACHE_ALIGN, NULL);
1560         if (!info->request_cache)
1561                 return -ENOMEM;
1562
1563         info->request_mempool =
1564                 mempool_create(info->send_credit_target, mempool_alloc_slab,
1565                         mempool_free_slab, info->request_cache);
1566         if (!info->request_mempool)
1567                 goto out1;
1568
1569         snprintf(name, MAX_NAME_LEN, "smbd_response_%p", info);
1570         info->response_cache =
1571                 kmem_cache_create(
1572                         name,
1573                         sizeof(struct smbd_response) +
1574                                 info->max_receive_size,
1575                         0, SLAB_HWCACHE_ALIGN, NULL);
1576         if (!info->response_cache)
1577                 goto out2;
1578
1579         info->response_mempool =
1580                 mempool_create(info->receive_credit_max, mempool_alloc_slab,
1581                        mempool_free_slab, info->response_cache);
1582         if (!info->response_mempool)
1583                 goto out3;
1584
1585         snprintf(name, MAX_NAME_LEN, "smbd_%p", info);
1586         info->workqueue = create_workqueue(name);
1587         if (!info->workqueue)
1588                 goto out4;
1589
1590         rc = allocate_receive_buffers(info, info->receive_credit_max);
1591         if (rc) {
1592                 log_rdma_event(ERR, "failed to allocate receive buffers\n");
1593                 goto out5;
1594         }
1595
1596         return 0;
1597
1598 out5:
1599         destroy_workqueue(info->workqueue);
1600 out4:
1601         mempool_destroy(info->response_mempool);
1602 out3:
1603         kmem_cache_destroy(info->response_cache);
1604 out2:
1605         mempool_destroy(info->request_mempool);
1606 out1:
1607         kmem_cache_destroy(info->request_cache);
1608         return -ENOMEM;
1609 }
1610
1611 /* Create a SMBD connection, called by upper layer */
1612 static struct smbd_connection *_smbd_get_connection(
1613         struct TCP_Server_Info *server, struct sockaddr *dstaddr, int port)
1614 {
1615         int rc;
1616         struct smbd_connection *info;
1617         struct rdma_conn_param conn_param;
1618         struct ib_qp_init_attr qp_attr;
1619         struct sockaddr_in *addr_in = (struct sockaddr_in *) dstaddr;
1620         struct ib_port_immutable port_immutable;
1621         u32 ird_ord_hdr[2];
1622
1623         info = kzalloc(sizeof(struct smbd_connection), GFP_KERNEL);
1624         if (!info)
1625                 return NULL;
1626
1627         info->transport_status = SMBD_CONNECTING;
1628         rc = smbd_ia_open(info, dstaddr, port);
1629         if (rc) {
1630                 log_rdma_event(INFO, "smbd_ia_open rc=%d\n", rc);
1631                 goto create_id_failed;
1632         }
1633
1634         if (smbd_send_credit_target > info->id->device->attrs.max_cqe ||
1635             smbd_send_credit_target > info->id->device->attrs.max_qp_wr) {
1636                 log_rdma_event(ERR,
1637                         "consider lowering send_credit_target = %d. "
1638                         "Possible CQE overrun, device "
1639                         "reporting max_cpe %d max_qp_wr %d\n",
1640                         smbd_send_credit_target,
1641                         info->id->device->attrs.max_cqe,
1642                         info->id->device->attrs.max_qp_wr);
1643                 goto config_failed;
1644         }
1645
1646         if (smbd_receive_credit_max > info->id->device->attrs.max_cqe ||
1647             smbd_receive_credit_max > info->id->device->attrs.max_qp_wr) {
1648                 log_rdma_event(ERR,
1649                         "consider lowering receive_credit_max = %d. "
1650                         "Possible CQE overrun, device "
1651                         "reporting max_cpe %d max_qp_wr %d\n",
1652                         smbd_receive_credit_max,
1653                         info->id->device->attrs.max_cqe,
1654                         info->id->device->attrs.max_qp_wr);
1655                 goto config_failed;
1656         }
1657
1658         info->receive_credit_max = smbd_receive_credit_max;
1659         info->send_credit_target = smbd_send_credit_target;
1660         info->max_send_size = smbd_max_send_size;
1661         info->max_fragmented_recv_size = smbd_max_fragmented_recv_size;
1662         info->max_receive_size = smbd_max_receive_size;
1663         info->keep_alive_interval = smbd_keep_alive_interval;
1664
1665         if (info->id->device->attrs.max_send_sge < SMBDIRECT_MAX_SGE) {
1666                 log_rdma_event(ERR,
1667                         "warning: device max_send_sge = %d too small\n",
1668                         info->id->device->attrs.max_send_sge);
1669                 log_rdma_event(ERR, "Queue Pair creation may fail\n");
1670         }
1671         if (info->id->device->attrs.max_recv_sge < SMBDIRECT_MAX_SGE) {
1672                 log_rdma_event(ERR,
1673                         "warning: device max_recv_sge = %d too small\n",
1674                         info->id->device->attrs.max_recv_sge);
1675                 log_rdma_event(ERR, "Queue Pair creation may fail\n");
1676         }
1677
1678         info->send_cq = NULL;
1679         info->recv_cq = NULL;
1680         info->send_cq = ib_alloc_cq(info->id->device, info,
1681                         info->send_credit_target, 0, IB_POLL_SOFTIRQ);
1682         if (IS_ERR(info->send_cq)) {
1683                 info->send_cq = NULL;
1684                 goto alloc_cq_failed;
1685         }
1686
1687         info->recv_cq = ib_alloc_cq(info->id->device, info,
1688                         info->receive_credit_max, 0, IB_POLL_SOFTIRQ);
1689         if (IS_ERR(info->recv_cq)) {
1690                 info->recv_cq = NULL;
1691                 goto alloc_cq_failed;
1692         }
1693
1694         memset(&qp_attr, 0, sizeof(qp_attr));
1695         qp_attr.event_handler = smbd_qp_async_error_upcall;
1696         qp_attr.qp_context = info;
1697         qp_attr.cap.max_send_wr = info->send_credit_target;
1698         qp_attr.cap.max_recv_wr = info->receive_credit_max;
1699         qp_attr.cap.max_send_sge = SMBDIRECT_MAX_SGE;
1700         qp_attr.cap.max_recv_sge = SMBDIRECT_MAX_SGE;
1701         qp_attr.cap.max_inline_data = 0;
1702         qp_attr.sq_sig_type = IB_SIGNAL_REQ_WR;
1703         qp_attr.qp_type = IB_QPT_RC;
1704         qp_attr.send_cq = info->send_cq;
1705         qp_attr.recv_cq = info->recv_cq;
1706         qp_attr.port_num = ~0;
1707
1708         rc = rdma_create_qp(info->id, info->pd, &qp_attr);
1709         if (rc) {
1710                 log_rdma_event(ERR, "rdma_create_qp failed %i\n", rc);
1711                 goto create_qp_failed;
1712         }
1713
1714         memset(&conn_param, 0, sizeof(conn_param));
1715         conn_param.initiator_depth = 0;
1716
1717         conn_param.responder_resources =
1718                 info->id->device->attrs.max_qp_rd_atom
1719                         < SMBD_CM_RESPONDER_RESOURCES ?
1720                 info->id->device->attrs.max_qp_rd_atom :
1721                 SMBD_CM_RESPONDER_RESOURCES;
1722         info->responder_resources = conn_param.responder_resources;
1723         log_rdma_mr(INFO, "responder_resources=%d\n",
1724                 info->responder_resources);
1725
1726         /* Need to send IRD/ORD in private data for iWARP */
1727         info->id->device->ops.get_port_immutable(
1728                 info->id->device, info->id->port_num, &port_immutable);
1729         if (port_immutable.core_cap_flags & RDMA_CORE_PORT_IWARP) {
1730                 ird_ord_hdr[0] = info->responder_resources;
1731                 ird_ord_hdr[1] = 1;
1732                 conn_param.private_data = ird_ord_hdr;
1733                 conn_param.private_data_len = sizeof(ird_ord_hdr);
1734         } else {
1735                 conn_param.private_data = NULL;
1736                 conn_param.private_data_len = 0;
1737         }
1738
1739         conn_param.retry_count = SMBD_CM_RETRY;
1740         conn_param.rnr_retry_count = SMBD_CM_RNR_RETRY;
1741         conn_param.flow_control = 0;
1742         init_waitqueue_head(&info->wait_destroy);
1743
1744         log_rdma_event(INFO, "connecting to IP %pI4 port %d\n",
1745                 &addr_in->sin_addr, port);
1746
1747         init_waitqueue_head(&info->conn_wait);
1748         rc = rdma_connect(info->id, &conn_param);
1749         if (rc) {
1750                 log_rdma_event(ERR, "rdma_connect() failed with %i\n", rc);
1751                 goto rdma_connect_failed;
1752         }
1753
1754         wait_event_interruptible(
1755                 info->conn_wait, info->transport_status != SMBD_CONNECTING);
1756
1757         if (info->transport_status != SMBD_CONNECTED) {
1758                 log_rdma_event(ERR, "rdma_connect failed port=%d\n", port);
1759                 goto rdma_connect_failed;
1760         }
1761
1762         log_rdma_event(INFO, "rdma_connect connected\n");
1763
1764         rc = allocate_caches_and_workqueue(info);
1765         if (rc) {
1766                 log_rdma_event(ERR, "cache allocation failed\n");
1767                 goto allocate_cache_failed;
1768         }
1769
1770         init_waitqueue_head(&info->wait_send_queue);
1771         init_waitqueue_head(&info->wait_reassembly_queue);
1772
1773         INIT_DELAYED_WORK(&info->idle_timer_work, idle_connection_timer);
1774         INIT_DELAYED_WORK(&info->send_immediate_work, send_immediate_work);
1775         queue_delayed_work(info->workqueue, &info->idle_timer_work,
1776                 info->keep_alive_interval*HZ);
1777
1778         init_waitqueue_head(&info->wait_smbd_send_pending);
1779         info->smbd_send_pending = 0;
1780
1781         init_waitqueue_head(&info->wait_smbd_recv_pending);
1782         info->smbd_recv_pending = 0;
1783
1784         init_waitqueue_head(&info->wait_send_pending);
1785         atomic_set(&info->send_pending, 0);
1786
1787         init_waitqueue_head(&info->wait_send_payload_pending);
1788         atomic_set(&info->send_payload_pending, 0);
1789
1790         INIT_WORK(&info->disconnect_work, smbd_disconnect_rdma_work);
1791         INIT_WORK(&info->destroy_work, smbd_destroy_rdma_work);
1792         INIT_WORK(&info->recv_done_work, smbd_recv_done_work);
1793         INIT_WORK(&info->post_send_credits_work, smbd_post_send_credits);
1794         info->new_credits_offered = 0;
1795         spin_lock_init(&info->lock_new_credits_offered);
1796
1797         rc = smbd_negotiate(info);
1798         if (rc) {
1799                 log_rdma_event(ERR, "smbd_negotiate rc=%d\n", rc);
1800                 goto negotiation_failed;
1801         }
1802
1803         rc = allocate_mr_list(info);
1804         if (rc) {
1805                 log_rdma_mr(ERR, "memory registration allocation failed\n");
1806                 goto allocate_mr_failed;
1807         }
1808
1809         return info;
1810
1811 allocate_mr_failed:
1812         /* At this point, need to a full transport shutdown */
1813         smbd_destroy(info);
1814         return NULL;
1815
1816 negotiation_failed:
1817         cancel_delayed_work_sync(&info->idle_timer_work);
1818         destroy_caches_and_workqueue(info);
1819         info->transport_status = SMBD_NEGOTIATE_FAILED;
1820         init_waitqueue_head(&info->conn_wait);
1821         rdma_disconnect(info->id);
1822         wait_event(info->conn_wait,
1823                 info->transport_status == SMBD_DISCONNECTED);
1824
1825 allocate_cache_failed:
1826 rdma_connect_failed:
1827         rdma_destroy_qp(info->id);
1828
1829 create_qp_failed:
1830 alloc_cq_failed:
1831         if (info->send_cq)
1832                 ib_free_cq(info->send_cq);
1833         if (info->recv_cq)
1834                 ib_free_cq(info->recv_cq);
1835
1836 config_failed:
1837         ib_dealloc_pd(info->pd);
1838         rdma_destroy_id(info->id);
1839
1840 create_id_failed:
1841         kfree(info);
1842         return NULL;
1843 }
1844
1845 struct smbd_connection *smbd_get_connection(
1846         struct TCP_Server_Info *server, struct sockaddr *dstaddr)
1847 {
1848         struct smbd_connection *ret;
1849         int port = SMBD_PORT;
1850
1851 try_again:
1852         ret = _smbd_get_connection(server, dstaddr, port);
1853
1854         /* Try SMB_PORT if SMBD_PORT doesn't work */
1855         if (!ret && port == SMBD_PORT) {
1856                 port = SMB_PORT;
1857                 goto try_again;
1858         }
1859         return ret;
1860 }
1861
1862 /*
1863  * Receive data from receive reassembly queue
1864  * All the incoming data packets are placed in reassembly queue
1865  * buf: the buffer to read data into
1866  * size: the length of data to read
1867  * return value: actual data read
1868  * Note: this implementation copies the data from reassebmly queue to receive
1869  * buffers used by upper layer. This is not the optimal code path. A better way
1870  * to do it is to not have upper layer allocate its receive buffers but rather
1871  * borrow the buffer from reassembly queue, and return it after data is
1872  * consumed. But this will require more changes to upper layer code, and also
1873  * need to consider packet boundaries while they still being reassembled.
1874  */
1875 static int smbd_recv_buf(struct smbd_connection *info, char *buf,
1876                 unsigned int size)
1877 {
1878         struct smbd_response *response;
1879         struct smbd_data_transfer *data_transfer;
1880         int to_copy, to_read, data_read, offset;
1881         u32 data_length, remaining_data_length, data_offset;
1882         int rc;
1883
1884 again:
1885         if (info->transport_status != SMBD_CONNECTED) {
1886                 log_read(ERR, "disconnected\n");
1887                 return -ENODEV;
1888         }
1889
1890         /*
1891          * No need to hold the reassembly queue lock all the time as we are
1892          * the only one reading from the front of the queue. The transport
1893          * may add more entries to the back of the queue at the same time
1894          */
1895         log_read(INFO, "size=%d info->reassembly_data_length=%d\n", size,
1896                 info->reassembly_data_length);
1897         if (info->reassembly_data_length >= size) {
1898                 int queue_length;
1899                 int queue_removed = 0;
1900
1901                 /*
1902                  * Need to make sure reassembly_data_length is read before
1903                  * reading reassembly_queue_length and calling
1904                  * _get_first_reassembly. This call is lock free
1905                  * as we never read at the end of the queue which are being
1906                  * updated in SOFTIRQ as more data is received
1907                  */
1908                 virt_rmb();
1909                 queue_length = info->reassembly_queue_length;
1910                 data_read = 0;
1911                 to_read = size;
1912                 offset = info->first_entry_offset;
1913                 while (data_read < size) {
1914                         response = _get_first_reassembly(info);
1915                         data_transfer = smbd_response_payload(response);
1916                         data_length = le32_to_cpu(data_transfer->data_length);
1917                         remaining_data_length =
1918                                 le32_to_cpu(
1919                                         data_transfer->remaining_data_length);
1920                         data_offset = le32_to_cpu(data_transfer->data_offset);
1921
1922                         /*
1923                          * The upper layer expects RFC1002 length at the
1924                          * beginning of the payload. Return it to indicate
1925                          * the total length of the packet. This minimize the
1926                          * change to upper layer packet processing logic. This
1927                          * will be eventually remove when an intermediate
1928                          * transport layer is added
1929                          */
1930                         if (response->first_segment && size == 4) {
1931                                 unsigned int rfc1002_len =
1932                                         data_length + remaining_data_length;
1933                                 *((__be32 *)buf) = cpu_to_be32(rfc1002_len);
1934                                 data_read = 4;
1935                                 response->first_segment = false;
1936                                 log_read(INFO, "returning rfc1002 length %d\n",
1937                                         rfc1002_len);
1938                                 goto read_rfc1002_done;
1939                         }
1940
1941                         to_copy = min_t(int, data_length - offset, to_read);
1942                         memcpy(
1943                                 buf + data_read,
1944                                 (char *)data_transfer + data_offset + offset,
1945                                 to_copy);
1946
1947                         /* move on to the next buffer? */
1948                         if (to_copy == data_length - offset) {
1949                                 queue_length--;
1950                                 /*
1951                                  * No need to lock if we are not at the
1952                                  * end of the queue
1953                                  */
1954                                 if (queue_length)
1955                                         list_del(&response->list);
1956                                 else {
1957                                         spin_lock_irq(
1958                                                 &info->reassembly_queue_lock);
1959                                         list_del(&response->list);
1960                                         spin_unlock_irq(
1961                                                 &info->reassembly_queue_lock);
1962                                 }
1963                                 queue_removed++;
1964                                 info->count_reassembly_queue--;
1965                                 info->count_dequeue_reassembly_queue++;
1966                                 put_receive_buffer(info, response);
1967                                 offset = 0;
1968                                 log_read(INFO, "put_receive_buffer offset=0\n");
1969                         } else
1970                                 offset += to_copy;
1971
1972                         to_read -= to_copy;
1973                         data_read += to_copy;
1974
1975                         log_read(INFO, "_get_first_reassembly memcpy %d bytes "
1976                                 "data_transfer_length-offset=%d after that "
1977                                 "to_read=%d data_read=%d offset=%d\n",
1978                                 to_copy, data_length - offset,
1979                                 to_read, data_read, offset);
1980                 }
1981
1982                 spin_lock_irq(&info->reassembly_queue_lock);
1983                 info->reassembly_data_length -= data_read;
1984                 info->reassembly_queue_length -= queue_removed;
1985                 spin_unlock_irq(&info->reassembly_queue_lock);
1986
1987                 info->first_entry_offset = offset;
1988                 log_read(INFO, "returning to thread data_read=%d "
1989                         "reassembly_data_length=%d first_entry_offset=%d\n",
1990                         data_read, info->reassembly_data_length,
1991                         info->first_entry_offset);
1992 read_rfc1002_done:
1993                 return data_read;
1994         }
1995
1996         log_read(INFO, "wait_event on more data\n");
1997         rc = wait_event_interruptible(
1998                 info->wait_reassembly_queue,
1999                 info->reassembly_data_length >= size ||
2000                         info->transport_status != SMBD_CONNECTED);
2001         /* Don't return any data if interrupted */
2002         if (rc)
2003                 return -ENODEV;
2004
2005         goto again;
2006 }
2007
2008 /*
2009  * Receive a page from receive reassembly queue
2010  * page: the page to read data into
2011  * to_read: the length of data to read
2012  * return value: actual data read
2013  */
2014 static int smbd_recv_page(struct smbd_connection *info,
2015                 struct page *page, unsigned int page_offset,
2016                 unsigned int to_read)
2017 {
2018         int ret;
2019         char *to_address;
2020         void *page_address;
2021
2022         /* make sure we have the page ready for read */
2023         ret = wait_event_interruptible(
2024                 info->wait_reassembly_queue,
2025                 info->reassembly_data_length >= to_read ||
2026                         info->transport_status != SMBD_CONNECTED);
2027         if (ret)
2028                 return ret;
2029
2030         /* now we can read from reassembly queue and not sleep */
2031         page_address = kmap_atomic(page);
2032         to_address = (char *) page_address + page_offset;
2033
2034         log_read(INFO, "reading from page=%p address=%p to_read=%d\n",
2035                 page, to_address, to_read);
2036
2037         ret = smbd_recv_buf(info, to_address, to_read);
2038         kunmap_atomic(page_address);
2039
2040         return ret;
2041 }
2042
2043 /*
2044  * Receive data from transport
2045  * msg: a msghdr point to the buffer, can be ITER_KVEC or ITER_BVEC
2046  * return: total bytes read, or 0. SMB Direct will not do partial read.
2047  */
2048 int smbd_recv(struct smbd_connection *info, struct msghdr *msg)
2049 {
2050         char *buf;
2051         struct page *page;
2052         unsigned int to_read, page_offset;
2053         int rc;
2054
2055         info->smbd_recv_pending++;
2056
2057         if (iov_iter_rw(&msg->msg_iter) == WRITE) {
2058                 /* It's a bug in upper layer to get there */
2059                 cifs_dbg(VFS, "CIFS: invalid msg iter dir %u\n",
2060                          iov_iter_rw(&msg->msg_iter));
2061                 rc = -EINVAL;
2062                 goto out;
2063         }
2064
2065         switch (iov_iter_type(&msg->msg_iter)) {
2066         case ITER_KVEC:
2067                 buf = msg->msg_iter.kvec->iov_base;
2068                 to_read = msg->msg_iter.kvec->iov_len;
2069                 rc = smbd_recv_buf(info, buf, to_read);
2070                 break;
2071
2072         case ITER_BVEC:
2073                 page = msg->msg_iter.bvec->bv_page;
2074                 page_offset = msg->msg_iter.bvec->bv_offset;
2075                 to_read = msg->msg_iter.bvec->bv_len;
2076                 rc = smbd_recv_page(info, page, page_offset, to_read);
2077                 break;
2078
2079         default:
2080                 /* It's a bug in upper layer to get there */
2081                 cifs_dbg(VFS, "CIFS: invalid msg type %d\n",
2082                          iov_iter_type(&msg->msg_iter));
2083                 rc = -EINVAL;
2084         }
2085
2086 out:
2087         info->smbd_recv_pending--;
2088         wake_up(&info->wait_smbd_recv_pending);
2089
2090         /* SMBDirect will read it all or nothing */
2091         if (rc > 0)
2092                 msg->msg_iter.count = 0;
2093         return rc;
2094 }
2095
2096 /*
2097  * Send data to transport
2098  * Each rqst is transported as a SMBDirect payload
2099  * rqst: the data to write
2100  * return value: 0 if successfully write, otherwise error code
2101  */
2102 int smbd_send(struct TCP_Server_Info *server, struct smb_rqst *rqst)
2103 {
2104         struct smbd_connection *info = server->smbd_conn;
2105         struct kvec vec;
2106         int nvecs;
2107         int size;
2108         unsigned int buflen, remaining_data_length;
2109         int start, i, j;
2110         int max_iov_size =
2111                 info->max_send_size - sizeof(struct smbd_data_transfer);
2112         struct kvec *iov;
2113         int rc;
2114
2115         info->smbd_send_pending++;
2116         if (info->transport_status != SMBD_CONNECTED) {
2117                 rc = -ENODEV;
2118                 goto done;
2119         }
2120
2121         /*
2122          * Skip the RFC1002 length defined in MS-SMB2 section 2.1
2123          * It is used only for TCP transport in the iov[0]
2124          * In future we may want to add a transport layer under protocol
2125          * layer so this will only be issued to TCP transport
2126          */
2127
2128         if (rqst->rq_iov[0].iov_len != 4) {
2129                 log_write(ERR, "expected the pdu length in 1st iov, but got %zu\n", rqst->rq_iov[0].iov_len);
2130                 return -EINVAL;
2131         }
2132
2133         /*
2134          * Add in the page array if there is one. The caller needs to set
2135          * rq_tailsz to PAGE_SIZE when the buffer has multiple pages and
2136          * ends at page boundary
2137          */
2138         buflen = smb_rqst_len(server, rqst);
2139
2140         if (buflen + sizeof(struct smbd_data_transfer) >
2141                 info->max_fragmented_send_size) {
2142                 log_write(ERR, "payload size %d > max size %d\n",
2143                         buflen, info->max_fragmented_send_size);
2144                 rc = -EINVAL;
2145                 goto done;
2146         }
2147
2148         iov = &rqst->rq_iov[1];
2149
2150         cifs_dbg(FYI, "Sending smb (RDMA): smb_len=%u\n", buflen);
2151         for (i = 0; i < rqst->rq_nvec-1; i++)
2152                 dump_smb(iov[i].iov_base, iov[i].iov_len);
2153
2154         remaining_data_length = buflen;
2155
2156         log_write(INFO, "rqst->rq_nvec=%d rqst->rq_npages=%d rq_pagesz=%d "
2157                 "rq_tailsz=%d buflen=%d\n",
2158                 rqst->rq_nvec, rqst->rq_npages, rqst->rq_pagesz,
2159                 rqst->rq_tailsz, buflen);
2160
2161         start = i = iov[0].iov_len ? 0 : 1;
2162         buflen = 0;
2163         while (true) {
2164                 buflen += iov[i].iov_len;
2165                 if (buflen > max_iov_size) {
2166                         if (i > start) {
2167                                 remaining_data_length -=
2168                                         (buflen-iov[i].iov_len);
2169                                 log_write(INFO, "sending iov[] from start=%d "
2170                                         "i=%d nvecs=%d "
2171                                         "remaining_data_length=%d\n",
2172                                         start, i, i-start,
2173                                         remaining_data_length);
2174                                 rc = smbd_post_send_data(
2175                                         info, &iov[start], i-start,
2176                                         remaining_data_length);
2177                                 if (rc)
2178                                         goto done;
2179                         } else {
2180                                 /* iov[start] is too big, break it */
2181                                 nvecs = (buflen+max_iov_size-1)/max_iov_size;
2182                                 log_write(INFO, "iov[%d] iov_base=%p buflen=%d"
2183                                         " break to %d vectors\n",
2184                                         start, iov[start].iov_base,
2185                                         buflen, nvecs);
2186                                 for (j = 0; j < nvecs; j++) {
2187                                         vec.iov_base =
2188                                                 (char *)iov[start].iov_base +
2189                                                 j*max_iov_size;
2190                                         vec.iov_len = max_iov_size;
2191                                         if (j == nvecs-1)
2192                                                 vec.iov_len =
2193                                                         buflen -
2194                                                         max_iov_size*(nvecs-1);
2195                                         remaining_data_length -= vec.iov_len;
2196                                         log_write(INFO,
2197                                                 "sending vec j=%d iov_base=%p"
2198                                                 " iov_len=%zu "
2199                                                 "remaining_data_length=%d\n",
2200                                                 j, vec.iov_base, vec.iov_len,
2201                                                 remaining_data_length);
2202                                         rc = smbd_post_send_data(
2203                                                 info, &vec, 1,
2204                                                 remaining_data_length);
2205                                         if (rc)
2206                                                 goto done;
2207                                 }
2208                                 i++;
2209                                 if (i == rqst->rq_nvec-1)
2210                                         break;
2211                         }
2212                         start = i;
2213                         buflen = 0;
2214                 } else {
2215                         i++;
2216                         if (i == rqst->rq_nvec-1) {
2217                                 /* send out all remaining vecs */
2218                                 remaining_data_length -= buflen;
2219                                 log_write(INFO,
2220                                         "sending iov[] from start=%d i=%d "
2221                                         "nvecs=%d remaining_data_length=%d\n",
2222                                         start, i, i-start,
2223                                         remaining_data_length);
2224                                 rc = smbd_post_send_data(info, &iov[start],
2225                                         i-start, remaining_data_length);
2226                                 if (rc)
2227                                         goto done;
2228                                 break;
2229                         }
2230                 }
2231                 log_write(INFO, "looping i=%d buflen=%d\n", i, buflen);
2232         }
2233
2234         /* now sending pages if there are any */
2235         for (i = 0; i < rqst->rq_npages; i++) {
2236                 unsigned int offset;
2237
2238                 rqst_page_get_length(rqst, i, &buflen, &offset);
2239                 nvecs = (buflen + max_iov_size - 1) / max_iov_size;
2240                 log_write(INFO, "sending pages buflen=%d nvecs=%d\n",
2241                         buflen, nvecs);
2242                 for (j = 0; j < nvecs; j++) {
2243                         size = max_iov_size;
2244                         if (j == nvecs-1)
2245                                 size = buflen - j*max_iov_size;
2246                         remaining_data_length -= size;
2247                         log_write(INFO, "sending pages i=%d offset=%d size=%d"
2248                                 " remaining_data_length=%d\n",
2249                                 i, j*max_iov_size+offset, size,
2250                                 remaining_data_length);
2251                         rc = smbd_post_send_page(
2252                                 info, rqst->rq_pages[i],
2253                                 j*max_iov_size + offset,
2254                                 size, remaining_data_length);
2255                         if (rc)
2256                                 goto done;
2257                 }
2258         }
2259
2260 done:
2261         /*
2262          * As an optimization, we don't wait for individual I/O to finish
2263          * before sending the next one.
2264          * Send them all and wait for pending send count to get to 0
2265          * that means all the I/Os have been out and we are good to return
2266          */
2267
2268         wait_event(info->wait_send_payload_pending,
2269                 atomic_read(&info->send_payload_pending) == 0);
2270
2271         info->smbd_send_pending--;
2272         wake_up(&info->wait_smbd_send_pending);
2273
2274         return rc;
2275 }
2276
2277 static void register_mr_done(struct ib_cq *cq, struct ib_wc *wc)
2278 {
2279         struct smbd_mr *mr;
2280         struct ib_cqe *cqe;
2281
2282         if (wc->status) {
2283                 log_rdma_mr(ERR, "status=%d\n", wc->status);
2284                 cqe = wc->wr_cqe;
2285                 mr = container_of(cqe, struct smbd_mr, cqe);
2286                 smbd_disconnect_rdma_connection(mr->conn);
2287         }
2288 }
2289
2290 /*
2291  * The work queue function that recovers MRs
2292  * We need to call ib_dereg_mr() and ib_alloc_mr() before this MR can be used
2293  * again. Both calls are slow, so finish them in a workqueue. This will not
2294  * block I/O path.
2295  * There is one workqueue that recovers MRs, there is no need to lock as the
2296  * I/O requests calling smbd_register_mr will never update the links in the
2297  * mr_list.
2298  */
2299 static void smbd_mr_recovery_work(struct work_struct *work)
2300 {
2301         struct smbd_connection *info =
2302                 container_of(work, struct smbd_connection, mr_recovery_work);
2303         struct smbd_mr *smbdirect_mr;
2304         int rc;
2305
2306         list_for_each_entry(smbdirect_mr, &info->mr_list, list) {
2307                 if (smbdirect_mr->state == MR_INVALIDATED)
2308                         ib_dma_unmap_sg(
2309                                 info->id->device, smbdirect_mr->sgl,
2310                                 smbdirect_mr->sgl_count,
2311                                 smbdirect_mr->dir);
2312                 else if (smbdirect_mr->state == MR_ERROR) {
2313
2314                         /* recover this MR entry */
2315                         rc = ib_dereg_mr(smbdirect_mr->mr);
2316                         if (rc) {
2317                                 log_rdma_mr(ERR,
2318                                         "ib_dereg_mr failed rc=%x\n",
2319                                         rc);
2320                                 smbd_disconnect_rdma_connection(info);
2321                                 continue;
2322                         }
2323
2324                         smbdirect_mr->mr = ib_alloc_mr(
2325                                 info->pd, info->mr_type,
2326                                 info->max_frmr_depth);
2327                         if (IS_ERR(smbdirect_mr->mr)) {
2328                                 log_rdma_mr(ERR,
2329                                         "ib_alloc_mr failed mr_type=%x "
2330                                         "max_frmr_depth=%x\n",
2331                                         info->mr_type,
2332                                         info->max_frmr_depth);
2333                                 smbd_disconnect_rdma_connection(info);
2334                                 continue;
2335                         }
2336                 } else
2337                         /* This MR is being used, don't recover it */
2338                         continue;
2339
2340                 smbdirect_mr->state = MR_READY;
2341
2342                 /* smbdirect_mr->state is updated by this function
2343                  * and is read and updated by I/O issuing CPUs trying
2344                  * to get a MR, the call to atomic_inc_return
2345                  * implicates a memory barrier and guarantees this
2346                  * value is updated before waking up any calls to
2347                  * get_mr() from the I/O issuing CPUs
2348                  */
2349                 if (atomic_inc_return(&info->mr_ready_count) == 1)
2350                         wake_up_interruptible(&info->wait_mr);
2351         }
2352 }
2353
2354 static void destroy_mr_list(struct smbd_connection *info)
2355 {
2356         struct smbd_mr *mr, *tmp;
2357
2358         cancel_work_sync(&info->mr_recovery_work);
2359         list_for_each_entry_safe(mr, tmp, &info->mr_list, list) {
2360                 if (mr->state == MR_INVALIDATED)
2361                         ib_dma_unmap_sg(info->id->device, mr->sgl,
2362                                 mr->sgl_count, mr->dir);
2363                 ib_dereg_mr(mr->mr);
2364                 kfree(mr->sgl);
2365                 kfree(mr);
2366         }
2367 }
2368
2369 /*
2370  * Allocate MRs used for RDMA read/write
2371  * The number of MRs will not exceed hardware capability in responder_resources
2372  * All MRs are kept in mr_list. The MR can be recovered after it's used
2373  * Recovery is done in smbd_mr_recovery_work. The content of list entry changes
2374  * as MRs are used and recovered for I/O, but the list links will not change
2375  */
2376 static int allocate_mr_list(struct smbd_connection *info)
2377 {
2378         int i;
2379         struct smbd_mr *smbdirect_mr, *tmp;
2380
2381         INIT_LIST_HEAD(&info->mr_list);
2382         init_waitqueue_head(&info->wait_mr);
2383         spin_lock_init(&info->mr_list_lock);
2384         atomic_set(&info->mr_ready_count, 0);
2385         atomic_set(&info->mr_used_count, 0);
2386         init_waitqueue_head(&info->wait_for_mr_cleanup);
2387         /* Allocate more MRs (2x) than hardware responder_resources */
2388         for (i = 0; i < info->responder_resources * 2; i++) {
2389                 smbdirect_mr = kzalloc(sizeof(*smbdirect_mr), GFP_KERNEL);
2390                 if (!smbdirect_mr)
2391                         goto out;
2392                 smbdirect_mr->mr = ib_alloc_mr(info->pd, info->mr_type,
2393                                         info->max_frmr_depth);
2394                 if (IS_ERR(smbdirect_mr->mr)) {
2395                         log_rdma_mr(ERR, "ib_alloc_mr failed mr_type=%x "
2396                                 "max_frmr_depth=%x\n",
2397                                 info->mr_type, info->max_frmr_depth);
2398                         goto out;
2399                 }
2400                 smbdirect_mr->sgl = kcalloc(
2401                                         info->max_frmr_depth,
2402                                         sizeof(struct scatterlist),
2403                                         GFP_KERNEL);
2404                 if (!smbdirect_mr->sgl) {
2405                         log_rdma_mr(ERR, "failed to allocate sgl\n");
2406                         ib_dereg_mr(smbdirect_mr->mr);
2407                         goto out;
2408                 }
2409                 smbdirect_mr->state = MR_READY;
2410                 smbdirect_mr->conn = info;
2411
2412                 list_add_tail(&smbdirect_mr->list, &info->mr_list);
2413                 atomic_inc(&info->mr_ready_count);
2414         }
2415         INIT_WORK(&info->mr_recovery_work, smbd_mr_recovery_work);
2416         return 0;
2417
2418 out:
2419         kfree(smbdirect_mr);
2420
2421         list_for_each_entry_safe(smbdirect_mr, tmp, &info->mr_list, list) {
2422                 ib_dereg_mr(smbdirect_mr->mr);
2423                 kfree(smbdirect_mr->sgl);
2424                 kfree(smbdirect_mr);
2425         }
2426         return -ENOMEM;
2427 }
2428
2429 /*
2430  * Get a MR from mr_list. This function waits until there is at least one
2431  * MR available in the list. It may access the list while the
2432  * smbd_mr_recovery_work is recovering the MR list. This doesn't need a lock
2433  * as they never modify the same places. However, there may be several CPUs
2434  * issueing I/O trying to get MR at the same time, mr_list_lock is used to
2435  * protect this situation.
2436  */
2437 static struct smbd_mr *get_mr(struct smbd_connection *info)
2438 {
2439         struct smbd_mr *ret;
2440         int rc;
2441 again:
2442         rc = wait_event_interruptible(info->wait_mr,
2443                 atomic_read(&info->mr_ready_count) ||
2444                 info->transport_status != SMBD_CONNECTED);
2445         if (rc) {
2446                 log_rdma_mr(ERR, "wait_event_interruptible rc=%x\n", rc);
2447                 return NULL;
2448         }
2449
2450         if (info->transport_status != SMBD_CONNECTED) {
2451                 log_rdma_mr(ERR, "info->transport_status=%x\n",
2452                         info->transport_status);
2453                 return NULL;
2454         }
2455
2456         spin_lock(&info->mr_list_lock);
2457         list_for_each_entry(ret, &info->mr_list, list) {
2458                 if (ret->state == MR_READY) {
2459                         ret->state = MR_REGISTERED;
2460                         spin_unlock(&info->mr_list_lock);
2461                         atomic_dec(&info->mr_ready_count);
2462                         atomic_inc(&info->mr_used_count);
2463                         return ret;
2464                 }
2465         }
2466
2467         spin_unlock(&info->mr_list_lock);
2468         /*
2469          * It is possible that we could fail to get MR because other processes may
2470          * try to acquire a MR at the same time. If this is the case, retry it.
2471          */
2472         goto again;
2473 }
2474
2475 /*
2476  * Register memory for RDMA read/write
2477  * pages[]: the list of pages to register memory with
2478  * num_pages: the number of pages to register
2479  * tailsz: if non-zero, the bytes to register in the last page
2480  * writing: true if this is a RDMA write (SMB read), false for RDMA read
2481  * need_invalidate: true if this MR needs to be locally invalidated after I/O
2482  * return value: the MR registered, NULL if failed.
2483  */
2484 struct smbd_mr *smbd_register_mr(
2485         struct smbd_connection *info, struct page *pages[], int num_pages,
2486         int offset, int tailsz, bool writing, bool need_invalidate)
2487 {
2488         struct smbd_mr *smbdirect_mr;
2489         int rc, i;
2490         enum dma_data_direction dir;
2491         struct ib_reg_wr *reg_wr;
2492
2493         if (num_pages > info->max_frmr_depth) {
2494                 log_rdma_mr(ERR, "num_pages=%d max_frmr_depth=%d\n",
2495                         num_pages, info->max_frmr_depth);
2496                 return NULL;
2497         }
2498
2499         smbdirect_mr = get_mr(info);
2500         if (!smbdirect_mr) {
2501                 log_rdma_mr(ERR, "get_mr returning NULL\n");
2502                 return NULL;
2503         }
2504         smbdirect_mr->need_invalidate = need_invalidate;
2505         smbdirect_mr->sgl_count = num_pages;
2506         sg_init_table(smbdirect_mr->sgl, num_pages);
2507
2508         log_rdma_mr(INFO, "num_pages=0x%x offset=0x%x tailsz=0x%x\n",
2509                         num_pages, offset, tailsz);
2510
2511         if (num_pages == 1) {
2512                 sg_set_page(&smbdirect_mr->sgl[0], pages[0], tailsz, offset);
2513                 goto skip_multiple_pages;
2514         }
2515
2516         /* We have at least two pages to register */
2517         sg_set_page(
2518                 &smbdirect_mr->sgl[0], pages[0], PAGE_SIZE - offset, offset);
2519         i = 1;
2520         while (i < num_pages - 1) {
2521                 sg_set_page(&smbdirect_mr->sgl[i], pages[i], PAGE_SIZE, 0);
2522                 i++;
2523         }
2524         sg_set_page(&smbdirect_mr->sgl[i], pages[i],
2525                 tailsz ? tailsz : PAGE_SIZE, 0);
2526
2527 skip_multiple_pages:
2528         dir = writing ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
2529         smbdirect_mr->dir = dir;
2530         rc = ib_dma_map_sg(info->id->device, smbdirect_mr->sgl, num_pages, dir);
2531         if (!rc) {
2532                 log_rdma_mr(ERR, "ib_dma_map_sg num_pages=%x dir=%x rc=%x\n",
2533                         num_pages, dir, rc);
2534                 goto dma_map_error;
2535         }
2536
2537         rc = ib_map_mr_sg(smbdirect_mr->mr, smbdirect_mr->sgl, num_pages,
2538                 NULL, PAGE_SIZE);
2539         if (rc != num_pages) {
2540                 log_rdma_mr(ERR,
2541                         "ib_map_mr_sg failed rc = %d num_pages = %x\n",
2542                         rc, num_pages);
2543                 goto map_mr_error;
2544         }
2545
2546         ib_update_fast_reg_key(smbdirect_mr->mr,
2547                 ib_inc_rkey(smbdirect_mr->mr->rkey));
2548         reg_wr = &smbdirect_mr->wr;
2549         reg_wr->wr.opcode = IB_WR_REG_MR;
2550         smbdirect_mr->cqe.done = register_mr_done;
2551         reg_wr->wr.wr_cqe = &smbdirect_mr->cqe;
2552         reg_wr->wr.num_sge = 0;
2553         reg_wr->wr.send_flags = IB_SEND_SIGNALED;
2554         reg_wr->mr = smbdirect_mr->mr;
2555         reg_wr->key = smbdirect_mr->mr->rkey;
2556         reg_wr->access = writing ?
2557                         IB_ACCESS_REMOTE_WRITE | IB_ACCESS_LOCAL_WRITE :
2558                         IB_ACCESS_REMOTE_READ;
2559
2560         /*
2561          * There is no need for waiting for complemtion on ib_post_send
2562          * on IB_WR_REG_MR. Hardware enforces a barrier and order of execution
2563          * on the next ib_post_send when we actaully send I/O to remote peer
2564          */
2565         rc = ib_post_send(info->id->qp, &reg_wr->wr, NULL);
2566         if (!rc)
2567                 return smbdirect_mr;
2568
2569         log_rdma_mr(ERR, "ib_post_send failed rc=%x reg_wr->key=%x\n",
2570                 rc, reg_wr->key);
2571
2572         /* If all failed, attempt to recover this MR by setting it MR_ERROR*/
2573 map_mr_error:
2574         ib_dma_unmap_sg(info->id->device, smbdirect_mr->sgl,
2575                 smbdirect_mr->sgl_count, smbdirect_mr->dir);
2576
2577 dma_map_error:
2578         smbdirect_mr->state = MR_ERROR;
2579         if (atomic_dec_and_test(&info->mr_used_count))
2580                 wake_up(&info->wait_for_mr_cleanup);
2581
2582         smbd_disconnect_rdma_connection(info);
2583
2584         return NULL;
2585 }
2586
2587 static void local_inv_done(struct ib_cq *cq, struct ib_wc *wc)
2588 {
2589         struct smbd_mr *smbdirect_mr;
2590         struct ib_cqe *cqe;
2591
2592         cqe = wc->wr_cqe;
2593         smbdirect_mr = container_of(cqe, struct smbd_mr, cqe);
2594         smbdirect_mr->state = MR_INVALIDATED;
2595         if (wc->status != IB_WC_SUCCESS) {
2596                 log_rdma_mr(ERR, "invalidate failed status=%x\n", wc->status);
2597                 smbdirect_mr->state = MR_ERROR;
2598         }
2599         complete(&smbdirect_mr->invalidate_done);
2600 }
2601
2602 /*
2603  * Deregister a MR after I/O is done
2604  * This function may wait if remote invalidation is not used
2605  * and we have to locally invalidate the buffer to prevent data is being
2606  * modified by remote peer after upper layer consumes it
2607  */
2608 int smbd_deregister_mr(struct smbd_mr *smbdirect_mr)
2609 {
2610         struct ib_send_wr *wr;
2611         struct smbd_connection *info = smbdirect_mr->conn;
2612         int rc = 0;
2613
2614         if (smbdirect_mr->need_invalidate) {
2615                 /* Need to finish local invalidation before returning */
2616                 wr = &smbdirect_mr->inv_wr;
2617                 wr->opcode = IB_WR_LOCAL_INV;
2618                 smbdirect_mr->cqe.done = local_inv_done;
2619                 wr->wr_cqe = &smbdirect_mr->cqe;
2620                 wr->num_sge = 0;
2621                 wr->ex.invalidate_rkey = smbdirect_mr->mr->rkey;
2622                 wr->send_flags = IB_SEND_SIGNALED;
2623
2624                 init_completion(&smbdirect_mr->invalidate_done);
2625                 rc = ib_post_send(info->id->qp, wr, NULL);
2626                 if (rc) {
2627                         log_rdma_mr(ERR, "ib_post_send failed rc=%x\n", rc);
2628                         smbd_disconnect_rdma_connection(info);
2629                         goto done;
2630                 }
2631                 wait_for_completion(&smbdirect_mr->invalidate_done);
2632                 smbdirect_mr->need_invalidate = false;
2633         } else
2634                 /*
2635                  * For remote invalidation, just set it to MR_INVALIDATED
2636                  * and defer to mr_recovery_work to recover the MR for next use
2637                  */
2638                 smbdirect_mr->state = MR_INVALIDATED;
2639
2640         /*
2641          * Schedule the work to do MR recovery for future I/Os
2642          * MR recovery is slow and we don't want it to block the current I/O
2643          */
2644         queue_work(info->workqueue, &info->mr_recovery_work);
2645
2646 done:
2647         if (atomic_dec_and_test(&info->mr_used_count))
2648                 wake_up(&info->wait_for_mr_cleanup);
2649
2650         return rc;
2651 }