drivers/target/iscsi/iscsi_target_erl1.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*******************************************************************************
   3  * This file contains error recovery level one used by the iSCSI Target driver.
   4  *
   5  * (c) Copyright 2007-2013 Datera, Inc.
   6  *
   7  * Author: Nicholas A. Bellinger <nab@linux-iscsi.org>
   8  *
   9  ******************************************************************************/
  10
  11 #include <linux/list.h>
  12 #include <linux/slab.h>
  13 #include <scsi/iscsi_proto.h>
  14 #include <target/target_core_base.h>
  15 #include <target/target_core_fabric.h>
  16 #include <target/iscsi/iscsi_transport.h>
  17
  18 #include <target/iscsi/iscsi_target_core.h>
  19 #include "iscsi_target_seq_pdu_list.h"
  20 #include "iscsi_target_datain_values.h"
  21 #include "iscsi_target_device.h"
  22 #include "iscsi_target_tpg.h"
  23 #include "iscsi_target_util.h"
  24 #include "iscsi_target_erl0.h"
  25 #include "iscsi_target_erl1.h"
  26 #include "iscsi_target_erl2.h"
  27 #include "iscsi_target.h"
  28
  29 #define OFFLOAD_BUF_SIZE        32768U
  30
  31 /*
  32  *      Used to dump excess datain payload for certain error recovery
  33  *      situations.  Receive in OFFLOAD_BUF_SIZE max of datain per rx_data().
  34  *
  35  *      dump_padding_digest denotes if padding and data digests need
  36  *      to be dumped.
  37  */
  38 int iscsit_dump_data_payload(
  39         struct iscsi_conn *conn,
  40         u32 buf_len,
  41         int dump_padding_digest)
  42 {
  43         char *buf;
  44         int ret = DATAOUT_WITHIN_COMMAND_RECOVERY, rx_got;
  45         u32 length, offset = 0, size;
  46         struct kvec iov;
  47
  48         if (conn->sess->sess_ops->RDMAExtensions)
  49                 return 0;
  50
  51         if (dump_padding_digest) {
  52                 buf_len = ALIGN(buf_len, 4);
  53                 if (conn->conn_ops->DataDigest)
  54                         buf_len += ISCSI_CRC_LEN;
  55         }
  56
  57         length = min(buf_len, OFFLOAD_BUF_SIZE);
  58
  59         buf = kzalloc(length, GFP_ATOMIC);
  60         if (!buf) {
  61                 pr_err("Unable to allocate %u bytes for offload"
  62                                 " buffer.\n", length);
  63                 return -1;
  64         }
  65         memset(&iov, 0, sizeof(struct kvec));
  66
  67         while (offset < buf_len) {
  68                 size = min(buf_len - offset, length);
  69
  70                 iov.iov_len = size;
  71                 iov.iov_base = buf;
  72
  73                 rx_got = rx_data(conn, &iov, 1, size);
  74                 if (rx_got != size) {
  75                         ret = DATAOUT_CANNOT_RECOVER;
  76                         break;
  77                 }
  78
  79                 offset += size;
  80         }
  81
  82         kfree(buf);
  83         return ret;
  84 }
  85
  86 /*
  87  *      Used for retransmitting R2Ts from a R2T SNACK request.
  88  */
  89 static int iscsit_send_recovery_r2t_for_snack(
  90         struct iscsi_cmd *cmd,
  91         struct iscsi_r2t *r2t)
  92 {
  93         /*
  94          * If the struct iscsi_r2t has not been sent yet, we can safely
  95          * ignore retransmission
  96          * of the R2TSN in question.
  97          */
  98         spin_lock_bh(&cmd->r2t_lock);
  99         if (!r2t->sent_r2t) {
 100                 spin_unlock_bh(&cmd->r2t_lock);
 101                 return 0;
 102         }
 103         r2t->sent_r2t = 0;
 104         spin_unlock_bh(&cmd->r2t_lock);
 105
 106         iscsit_add_cmd_to_immediate_queue(cmd, cmd->conn, ISTATE_SEND_R2T);
 107
 108         return 0;
 109 }
 110
 111 static int iscsit_handle_r2t_snack(
 112         struct iscsi_cmd *cmd,
 113         unsigned char *buf,
 114         u32 begrun,
 115         u32 runlength)
 116 {
 117         u32 last_r2tsn;
 118         struct iscsi_r2t *r2t;
 119
 120         /*
 121          * Make sure the initiator is not requesting retransmission
 122          * of R2TSNs already acknowledged by a TMR TASK_REASSIGN.
 123          */
 124         if ((cmd->cmd_flags & ICF_GOT_DATACK_SNACK) &&
 125             (begrun <= cmd->acked_data_sn)) {
 126                 pr_err("ITT: 0x%08x, R2T SNACK requesting"
 127                         " retransmission of R2TSN: 0x%08x to 0x%08x but already"
 128                         " acked to  R2TSN: 0x%08x by TMR TASK_REASSIGN,"
 129                         " protocol error.\n", cmd->init_task_tag, begrun,
 130                         (begrun + runlength), cmd->acked_data_sn);
 131
 132                 return iscsit_reject_cmd(cmd, ISCSI_REASON_PROTOCOL_ERROR, buf);
 133         }
 134
 135         if (runlength) {
 136                 if ((begrun + runlength) > cmd->r2t_sn) {
 137                         pr_err("Command ITT: 0x%08x received R2T SNACK"
 138                         " with BegRun: 0x%08x, RunLength: 0x%08x, exceeds"
 139                         " current R2TSN: 0x%08x, protocol error.\n",
 140                         cmd->init_task_tag, begrun, runlength, cmd->r2t_sn);
 141                         return iscsit_reject_cmd(cmd,
 142                                         ISCSI_REASON_BOOKMARK_INVALID, buf);
 143                 }
 144                 last_r2tsn = (begrun + runlength);
 145         } else
 146                 last_r2tsn = cmd->r2t_sn;
 147
 148         while (begrun < last_r2tsn) {
 149                 r2t = iscsit_get_holder_for_r2tsn(cmd, begrun);
 150                 if (!r2t)
 151                         return -1;
 152                 if (iscsit_send_recovery_r2t_for_snack(cmd, r2t) < 0)
 153                         return -1;
 154
 155                 begrun++;
 156         }
 157
 158         return 0;
 159 }
 160
 161 /*
 162  *      Generates Offsets and NextBurstLength based on Begrun and Runlength
 163  *      carried in a Data SNACK or ExpDataSN in TMR TASK_REASSIGN.
 164  *
 165  *      For DataSequenceInOrder=Yes and DataPDUInOrder=[Yes,No] only.
 166  *
 167  *      FIXME: How is this handled for a RData SNACK?
 168  */
 169 int iscsit_create_recovery_datain_values_datasequenceinorder_yes(
 170         struct iscsi_cmd *cmd,
 171         struct iscsi_datain_req *dr)
 172 {
 173         u32 data_sn = 0, data_sn_count = 0;
 174         u32 pdu_start = 0, seq_no = 0;
 175         u32 begrun = dr->begrun;
 176         struct iscsi_conn *conn = cmd->conn;
 177
 178         while (begrun > data_sn++) {
 179                 data_sn_count++;
 180                 if ((dr->next_burst_len +
 181                      conn->conn_ops->MaxRecvDataSegmentLength) <
 182                      conn->sess->sess_ops->MaxBurstLength) {
 183                         dr->read_data_done +=
 184                                 conn->conn_ops->MaxRecvDataSegmentLength;
 185                         dr->next_burst_len +=
 186                                 conn->conn_ops->MaxRecvDataSegmentLength;
 187                 } else {
 188                         dr->read_data_done +=
 189                                 (conn->sess->sess_ops->MaxBurstLength -
 190                                  dr->next_burst_len);
 191                         dr->next_burst_len = 0;
 192                         pdu_start += data_sn_count;
 193                         data_sn_count = 0;
 194                         seq_no++;
 195                 }
 196         }
 197
 198         if (!conn->sess->sess_ops->DataPDUInOrder) {
 199                 cmd->seq_no = seq_no;
 200                 cmd->pdu_start = pdu_start;
 201                 cmd->pdu_send_order = data_sn_count;
 202         }
 203
 204         return 0;
 205 }
 206
 207 /*
 208  *      Generates Offsets and NextBurstLength based on Begrun and Runlength
 209  *      carried in a Data SNACK or ExpDataSN in TMR TASK_REASSIGN.
 210  *
 211  *      For DataSequenceInOrder=No and DataPDUInOrder=[Yes,No] only.
 212  *
 213  *      FIXME: How is this handled for a RData SNACK?
 214  */
 215 int iscsit_create_recovery_datain_values_datasequenceinorder_no(
 216         struct iscsi_cmd *cmd,
 217         struct iscsi_datain_req *dr)
 218 {
 219         int found_seq = 0, i;
 220         u32 data_sn, read_data_done = 0, seq_send_order = 0;
 221         u32 begrun = dr->begrun;
 222         u32 runlength = dr->runlength;
 223         struct iscsi_conn *conn = cmd->conn;
 224         struct iscsi_seq *first_seq = NULL, *seq = NULL;
 225
 226         if (!cmd->seq_list) {
 227                 pr_err("struct iscsi_cmd->seq_list is NULL!\n");
 228                 return -1;
 229         }
 230
 231         /*
 232          * Calculate read_data_done for all sequences containing a
 233          * first_datasn and last_datasn less than the BegRun.
 234          *
 235          * Locate the struct iscsi_seq the BegRun lies within and calculate
 236          * NextBurstLenghth up to the DataSN based on MaxRecvDataSegmentLength.
 237          *
 238          * Also use struct iscsi_seq->seq_send_order to determine where to start.
 239          */
 240         for (i = 0; i < cmd->seq_count; i++) {
 241                 seq = &cmd->seq_list[i];
 242
 243                 if (!seq->seq_send_order)
 244                         first_seq = seq;
 245
 246                 /*
 247                  * No data has been transferred for this DataIN sequence, so the
 248                  * seq->first_datasn and seq->last_datasn have not been set.
 249                  */
 250                 if (!seq->sent) {
 251                         pr_err("Ignoring non-sent sequence 0x%08x ->"
 252                                 " 0x%08x\n\n", seq->first_datasn,
 253                                 seq->last_datasn);
 254                         continue;
 255                 }
 256
 257                 /*
 258                  * This DataIN sequence is precedes the received BegRun, add the
 259                  * total xfer_len of the sequence to read_data_done and reset
 260                  * seq->pdu_send_order.
 261                  */
 262                 if ((seq->first_datasn < begrun) &&
 263                                 (seq->last_datasn < begrun)) {
 264                         pr_err("Pre BegRun sequence 0x%08x ->"
 265                                 " 0x%08x\n", seq->first_datasn,
 266                                 seq->last_datasn);
 267
 268                         read_data_done += cmd->seq_list[i].xfer_len;
 269                         seq->next_burst_len = seq->pdu_send_order = 0;
 270                         continue;
 271                 }
 272
 273                 /*
 274                  * The BegRun lies within this DataIN sequence.
 275                  */
 276                 if ((seq->first_datasn <= begrun) &&
 277                                 (seq->last_datasn >= begrun)) {
 278                         pr_err("Found sequence begrun: 0x%08x in"
 279                                 " 0x%08x -> 0x%08x\n", begrun,
 280                                 seq->first_datasn, seq->last_datasn);
 281
 282                         seq_send_order = seq->seq_send_order;
 283                         data_sn = seq->first_datasn;
 284                         seq->next_burst_len = seq->pdu_send_order = 0;
 285                         found_seq = 1;
 286
 287                         /*
 288                          * For DataPDUInOrder=Yes, while the first DataSN of
 289                          * the sequence is less than the received BegRun, add
 290                          * the MaxRecvDataSegmentLength to read_data_done and
 291                          * to the sequence's next_burst_len;
 292                          *
 293                          * For DataPDUInOrder=No, while the first DataSN of the
 294                          * sequence is less than the received BegRun, find the
 295                          * struct iscsi_pdu of the DataSN in question and add the
 296                          * MaxRecvDataSegmentLength to read_data_done and to the
 297                          * sequence's next_burst_len;
 298                          */
 299                         if (conn->sess->sess_ops->DataPDUInOrder) {
 300                                 while (data_sn < begrun) {
 301                                         seq->pdu_send_order++;
 302                                         read_data_done +=
 303                                                 conn->conn_ops->MaxRecvDataSegmentLength;
 304                                         seq->next_burst_len +=
 305                                                 conn->conn_ops->MaxRecvDataSegmentLength;
 306                                         data_sn++;
 307                                 }
 308                         } else {
 309                                 int j;
 310                                 struct iscsi_pdu *pdu;
 311
 312                                 while (data_sn < begrun) {
 313                                         seq->pdu_send_order++;
 314
 315                                         for (j = 0; j < seq->pdu_count; j++) {
 316                                                 pdu = &cmd->pdu_list[
 317                                                         seq->pdu_start + j];
 318                                                 if (pdu->data_sn == data_sn) {
 319                                                         read_data_done +=
 320                                                                 pdu->length;
 321                                                         seq->next_burst_len +=
 322                                                                 pdu->length;
 323                                                 }
 324                                         }
 325                                         data_sn++;
 326                                 }
 327                         }
 328                         continue;
 329                 }
 330
 331                 /*
 332                  * This DataIN sequence is larger than the received BegRun,
 333                  * reset seq->pdu_send_order and continue.
 334                  */
 335                 if ((seq->first_datasn > begrun) ||
 336                                 (seq->last_datasn > begrun)) {
 337                         pr_err("Post BegRun sequence 0x%08x -> 0x%08x\n",
 338                                         seq->first_datasn, seq->last_datasn);
 339
 340                         seq->next_burst_len = seq->pdu_send_order = 0;
 341                         continue;
 342                 }
 343         }
 344
 345         if (!found_seq) {
 346                 if (!begrun) {
 347                         if (!first_seq) {
 348                                 pr_err("ITT: 0x%08x, Begrun: 0x%08x"
 349                                         " but first_seq is NULL\n",
 350                                         cmd->init_task_tag, begrun);
 351                                 return -1;
 352                         }
 353                         seq_send_order = first_seq->seq_send_order;
 354                         seq->next_burst_len = seq->pdu_send_order = 0;
 355                         goto done;
 356                 }
 357
 358                 pr_err("Unable to locate struct iscsi_seq for ITT: 0x%08x,"
 359                         " BegRun: 0x%08x, RunLength: 0x%08x while"
 360                         " DataSequenceInOrder=No and DataPDUInOrder=%s.\n",
 361                                 cmd->init_task_tag, begrun, runlength,
 362                         (conn->sess->sess_ops->DataPDUInOrder) ? "Yes" : "No");
 363                 return -1;
 364         }
 365
 366 done:
 367         dr->read_data_done = read_data_done;
 368         dr->seq_send_order = seq_send_order;
 369
 370         return 0;
 371 }
 372
 373 static int iscsit_handle_recovery_datain(
 374         struct iscsi_cmd *cmd,
 375         unsigned char *buf,
 376         u32 begrun,
 377         u32 runlength)
 378 {
 379         struct iscsi_conn *conn = cmd->conn;
 380         struct iscsi_datain_req *dr;
 381         struct se_cmd *se_cmd = &cmd->se_cmd;
 382
 383         if (!(se_cmd->transport_state & CMD_T_COMPLETE)) {
 384                 pr_err("Ignoring ITT: 0x%08x Data SNACK\n",
 385                                 cmd->init_task_tag);
 386                 return 0;
 387         }
 388
 389         /*
 390          * Make sure the initiator is not requesting retransmission
 391          * of DataSNs already acknowledged by a Data ACK SNACK.
 392          */
 393         if ((cmd->cmd_flags & ICF_GOT_DATACK_SNACK) &&
 394             (begrun <= cmd->acked_data_sn)) {
 395                 pr_err("ITT: 0x%08x, Data SNACK requesting"
 396                         " retransmission of DataSN: 0x%08x to 0x%08x but"
 397                         " already acked to DataSN: 0x%08x by Data ACK SNACK,"
 398                         " protocol error.\n", cmd->init_task_tag, begrun,
 399                         (begrun + runlength), cmd->acked_data_sn);
 400
 401                 return iscsit_reject_cmd(cmd, ISCSI_REASON_PROTOCOL_ERROR, buf);
 402         }
 403
 404         /*
 405          * Make sure BegRun and RunLength in the Data SNACK are sane.
 406          * Note: (cmd->data_sn - 1) will carry the maximum DataSN sent.
 407          */
 408         if ((begrun + runlength) > (cmd->data_sn - 1)) {
 409                 pr_err("Initiator requesting BegRun: 0x%08x, RunLength"
 410                         ": 0x%08x greater than maximum DataSN: 0x%08x.\n",
 411                                 begrun, runlength, (cmd->data_sn - 1));
 412                 return iscsit_reject_cmd(cmd, ISCSI_REASON_BOOKMARK_INVALID,
 413                                          buf);
 414         }
 415
 416         dr = iscsit_allocate_datain_req();
 417         if (!dr)
 418                 return iscsit_reject_cmd(cmd, ISCSI_REASON_BOOKMARK_NO_RESOURCES,
 419                                          buf);
 420
 421         dr->data_sn = dr->begrun = begrun;
 422         dr->runlength = runlength;
 423         dr->generate_recovery_values = 1;
 424         dr->recovery = DATAIN_WITHIN_COMMAND_RECOVERY;
 425
 426         iscsit_attach_datain_req(cmd, dr);
 427
 428         cmd->i_state = ISTATE_SEND_DATAIN;
 429         iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
 430
 431         return 0;
 432 }
 433
 434 int iscsit_handle_recovery_datain_or_r2t(
 435         struct iscsi_conn *conn,
 436         unsigned char *buf,
 437         itt_t init_task_tag,
 438         u32 targ_xfer_tag,
 439         u32 begrun,
 440         u32 runlength)
 441 {
 442         struct iscsi_cmd *cmd;
 443
 444         cmd = iscsit_find_cmd_from_itt(conn, init_task_tag);
 445         if (!cmd)
 446                 return 0;
 447
 448         /*
 449          * FIXME: This will not work for bidi commands.
 450          */
 451         switch (cmd->data_direction) {
 452         case DMA_TO_DEVICE:
 453                 return iscsit_handle_r2t_snack(cmd, buf, begrun, runlength);
 454         case DMA_FROM_DEVICE:
 455                 return iscsit_handle_recovery_datain(cmd, buf, begrun,
 456                                 runlength);
 457         default:
 458                 pr_err("Unknown cmd->data_direction: 0x%02x\n",
 459                                 cmd->data_direction);
 460                 return -1;
 461         }
 462
 463         return 0;
 464 }
 465
 466 /* #warning FIXME: Status SNACK needs to be dependent on OPCODE!!! */
 467 int iscsit_handle_status_snack(
 468         struct iscsi_conn *conn,
 469         itt_t init_task_tag,
 470         u32 targ_xfer_tag,
 471         u32 begrun,
 472         u32 runlength)
 473 {
 474         struct iscsi_cmd *cmd = NULL;
 475         u32 last_statsn;
 476         int found_cmd;
 477
 478         if (!begrun) {
 479                 begrun = conn->exp_statsn;
 480         } else if (conn->exp_statsn > begrun) {
 481                 pr_err("Got Status SNACK Begrun: 0x%08x, RunLength:"
 482                         " 0x%08x but already got ExpStatSN: 0x%08x on CID:"
 483                         " %hu.\n", begrun, runlength, conn->exp_statsn,
 484                         conn->cid);
 485                 return 0;
 486         }
 487
 488         last_statsn = (!runlength) ? conn->stat_sn : (begrun + runlength);
 489
 490         while (begrun < last_statsn) {
 491                 found_cmd = 0;
 492
 493                 spin_lock_bh(&conn->cmd_lock);
 494                 list_for_each_entry(cmd, &conn->conn_cmd_list, i_conn_node) {
 495                         if (cmd->stat_sn == begrun) {
 496                                 found_cmd = 1;
 497                                 break;
 498                         }
 499                 }
 500                 spin_unlock_bh(&conn->cmd_lock);
 501
 502                 if (!found_cmd) {
 503                         pr_err("Unable to find StatSN: 0x%08x for"
 504                                 " a Status SNACK, assuming this was a"
 505                                 " protactic SNACK for an untransmitted"
 506                                 " StatSN, ignoring.\n", begrun);
 507                         begrun++;
 508                         continue;
 509                 }
 510
 511                 spin_lock_bh(&cmd->istate_lock);
 512                 if (cmd->i_state == ISTATE_SEND_DATAIN) {
 513                         spin_unlock_bh(&cmd->istate_lock);
 514                         pr_err("Ignoring Status SNACK for BegRun:"
 515                                 " 0x%08x, RunLength: 0x%08x, assuming this was"
 516                                 " a protactic SNACK for an untransmitted"
 517                                 " StatSN\n", begrun, runlength);
 518                         begrun++;
 519                         continue;
 520                 }
 521                 spin_unlock_bh(&cmd->istate_lock);
 522
 523                 cmd->i_state = ISTATE_SEND_STATUS_RECOVERY;
 524                 iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
 525                 begrun++;
 526         }
 527
 528         return 0;
 529 }
 530
 531 int iscsit_handle_data_ack(
 532         struct iscsi_conn *conn,
 533         u32 targ_xfer_tag,
 534         u32 begrun,
 535         u32 runlength)
 536 {
 537         struct iscsi_cmd *cmd = NULL;
 538
 539         cmd = iscsit_find_cmd_from_ttt(conn, targ_xfer_tag);
 540         if (!cmd) {
 541                 pr_err("Data ACK SNACK for TTT: 0x%08x is"
 542                         " invalid.\n", targ_xfer_tag);
 543                 return -1;
 544         }
 545
 546         if (begrun <= cmd->acked_data_sn) {
 547                 pr_err("ITT: 0x%08x Data ACK SNACK BegRUN: 0x%08x is"
 548                         " less than the already acked DataSN: 0x%08x.\n",
 549                         cmd->init_task_tag, begrun, cmd->acked_data_sn);
 550                 return -1;
 551         }
 552
 553         /*
 554          * For Data ACK SNACK, BegRun is the next expected DataSN.
 555          * (see iSCSI v19: 10.16.6)
 556          */
 557         cmd->cmd_flags |= ICF_GOT_DATACK_SNACK;
 558         cmd->acked_data_sn = (begrun - 1);
 559
 560         pr_debug("Received Data ACK SNACK for ITT: 0x%08x,"
 561                 " updated acked DataSN to 0x%08x.\n",
 562                         cmd->init_task_tag, cmd->acked_data_sn);
 563
 564         return 0;
 565 }
 566
 567 static int iscsit_send_recovery_r2t(
 568         struct iscsi_cmd *cmd,
 569         u32 offset,
 570         u32 xfer_len)
 571 {
 572         int ret;
 573
 574         spin_lock_bh(&cmd->r2t_lock);
 575         ret = iscsit_add_r2t_to_list(cmd, offset, xfer_len, 1, 0);
 576         spin_unlock_bh(&cmd->r2t_lock);
 577
 578         return ret;
 579 }
 580
 581 int iscsit_dataout_datapduinorder_no_fbit(
 582         struct iscsi_cmd *cmd,
 583         struct iscsi_pdu *pdu)
 584 {
 585         int i, send_recovery_r2t = 0, recovery = 0;
 586         u32 length = 0, offset = 0, pdu_count = 0, xfer_len = 0;
 587         struct iscsi_conn *conn = cmd->conn;
 588         struct iscsi_pdu *first_pdu = NULL;
 589
 590         /*
 591          * Get an struct iscsi_pdu pointer to the first PDU, and total PDU count
 592          * of the DataOUT sequence.
 593          */
 594         if (conn->sess->sess_ops->DataSequenceInOrder) {
 595                 for (i = 0; i < cmd->pdu_count; i++) {
 596                         if (cmd->pdu_list[i].seq_no == pdu->seq_no) {
 597                                 if (!first_pdu)
 598                                         first_pdu = &cmd->pdu_list[i];
 599                                 xfer_len += cmd->pdu_list[i].length;
 600                                 pdu_count++;
 601                         } else if (pdu_count)
 602                                 break;
 603                 }
 604         } else {
 605                 struct iscsi_seq *seq = cmd->seq_ptr;
 606
 607                 first_pdu = &cmd->pdu_list[seq->pdu_start];
 608                 pdu_count = seq->pdu_count;
 609         }
 610
 611         if (!first_pdu || !pdu_count)
 612                 return DATAOUT_CANNOT_RECOVER;
 613
 614         /*
 615          * Loop through the ending DataOUT Sequence checking each struct iscsi_pdu.
 616          * The following ugly logic does batching of not received PDUs.
 617          */
 618         for (i = 0; i < pdu_count; i++) {
 619                 if (first_pdu[i].status == ISCSI_PDU_RECEIVED_OK) {
 620                         if (!send_recovery_r2t)
 621                                 continue;
 622
 623                         if (iscsit_send_recovery_r2t(cmd, offset, length) < 0)
 624                                 return DATAOUT_CANNOT_RECOVER;
 625
 626                         send_recovery_r2t = length = offset = 0;
 627                         continue;
 628                 }
 629                 /*
 630                  * Set recovery = 1 for any missing, CRC failed, or timed
 631                  * out PDUs to let the DataOUT logic know that this sequence
 632                  * has not been completed yet.
 633                  *
 634                  * Also, only send a Recovery R2T for ISCSI_PDU_NOT_RECEIVED.
 635                  * We assume if the PDU either failed CRC or timed out
 636                  * that a Recovery R2T has already been sent.
 637                  */
 638                 recovery = 1;
 639
 640                 if (first_pdu[i].status != ISCSI_PDU_NOT_RECEIVED)
 641                         continue;
 642
 643                 if (!offset)
 644                         offset = first_pdu[i].offset;
 645                 length += first_pdu[i].length;
 646
 647                 send_recovery_r2t = 1;
 648         }
 649
 650         if (send_recovery_r2t)
 651                 if (iscsit_send_recovery_r2t(cmd, offset, length) < 0)
 652                         return DATAOUT_CANNOT_RECOVER;
 653
 654         return (!recovery) ? DATAOUT_NORMAL : DATAOUT_WITHIN_COMMAND_RECOVERY;
 655 }
 656
 657 static int iscsit_recalculate_dataout_values(
 658         struct iscsi_cmd *cmd,
 659         u32 pdu_offset,
 660         u32 pdu_length,
 661         u32 *r2t_offset,
 662         u32 *r2t_length)
 663 {
 664         int i;
 665         struct iscsi_conn *conn = cmd->conn;
 666         struct iscsi_pdu *pdu = NULL;
 667
 668         if (conn->sess->sess_ops->DataSequenceInOrder) {
 669                 cmd->data_sn = 0;
 670
 671                 if (conn->sess->sess_ops->DataPDUInOrder) {
 672                         *r2t_offset = cmd->write_data_done;
 673                         *r2t_length = (cmd->seq_end_offset -
 674                                         cmd->write_data_done);
 675                         return 0;
 676                 }
 677
 678                 *r2t_offset = cmd->seq_start_offset;
 679                 *r2t_length = (cmd->seq_end_offset - cmd->seq_start_offset);
 680
 681                 for (i = 0; i < cmd->pdu_count; i++) {
 682                         pdu = &cmd->pdu_list[i];
 683
 684                         if (pdu->status != ISCSI_PDU_RECEIVED_OK)
 685                                 continue;
 686
 687                         if ((pdu->offset >= cmd->seq_start_offset) &&
 688                            ((pdu->offset + pdu->length) <=
 689                              cmd->seq_end_offset)) {
 690                                 if (!cmd->unsolicited_data)
 691                                         cmd->next_burst_len -= pdu->length;
 692                                 else
 693                                         cmd->first_burst_len -= pdu->length;
 694
 695                                 cmd->write_data_done -= pdu->length;
 696                                 pdu->status = ISCSI_PDU_NOT_RECEIVED;
 697                         }
 698                 }
 699         } else {
 700                 struct iscsi_seq *seq = NULL;
 701
 702                 seq = iscsit_get_seq_holder(cmd, pdu_offset, pdu_length);
 703                 if (!seq)
 704                         return -1;
 705
 706                 *r2t_offset = seq->orig_offset;
 707                 *r2t_length = seq->xfer_len;
 708
 709                 cmd->write_data_done -= (seq->offset - seq->orig_offset);
 710                 if (cmd->immediate_data)
 711                         cmd->first_burst_len = cmd->write_data_done;
 712
 713                 seq->data_sn = 0;
 714                 seq->offset = seq->orig_offset;
 715                 seq->next_burst_len = 0;
 716                 seq->status = DATAOUT_SEQUENCE_WITHIN_COMMAND_RECOVERY;
 717
 718                 if (conn->sess->sess_ops->DataPDUInOrder)
 719                         return 0;
 720
 721                 for (i = 0; i < seq->pdu_count; i++) {
 722                         pdu = &cmd->pdu_list[i+seq->pdu_start];
 723
 724                         if (pdu->status != ISCSI_PDU_RECEIVED_OK)
 725                                 continue;
 726
 727                         pdu->status = ISCSI_PDU_NOT_RECEIVED;
 728                 }
 729         }
 730
 731         return 0;
 732 }
 733
 734 int iscsit_recover_dataout_sequence(
 735         struct iscsi_cmd *cmd,
 736         u32 pdu_offset,
 737         u32 pdu_length)
 738 {
 739         u32 r2t_length = 0, r2t_offset = 0;
 740
 741         spin_lock_bh(&cmd->istate_lock);
 742         cmd->cmd_flags |= ICF_WITHIN_COMMAND_RECOVERY;
 743         spin_unlock_bh(&cmd->istate_lock);
 744
 745         if (iscsit_recalculate_dataout_values(cmd, pdu_offset, pdu_length,
 746                         &r2t_offset, &r2t_length) < 0)
 747                 return DATAOUT_CANNOT_RECOVER;
 748
 749         iscsit_send_recovery_r2t(cmd, r2t_offset, r2t_length);
 750
 751         return DATAOUT_WITHIN_COMMAND_RECOVERY;
 752 }
 753
 754 static struct iscsi_ooo_cmdsn *iscsit_allocate_ooo_cmdsn(void)
 755 {
 756         struct iscsi_ooo_cmdsn *ooo_cmdsn = NULL;
 757
 758         ooo_cmdsn = kmem_cache_zalloc(lio_ooo_cache, GFP_ATOMIC);
 759         if (!ooo_cmdsn) {
 760                 pr_err("Unable to allocate memory for"
 761                         " struct iscsi_ooo_cmdsn.\n");
 762                 return NULL;
 763         }
 764         INIT_LIST_HEAD(&ooo_cmdsn->ooo_list);
 765
 766         return ooo_cmdsn;
 767 }
 768
 769 static int iscsit_attach_ooo_cmdsn(
 770         struct iscsi_session *sess,
 771         struct iscsi_ooo_cmdsn *ooo_cmdsn)
 772 {
 773         struct iscsi_ooo_cmdsn *ooo_tail, *ooo_tmp;
 774
 775         lockdep_assert_held(&sess->cmdsn_mutex);
 776
 777         /*
 778          * We attach the struct iscsi_ooo_cmdsn entry to the out of order
 779          * list in increasing CmdSN order.
 780          * This allows iscsi_execute_ooo_cmdsns() to detect any
 781          * additional CmdSN holes while performing delayed execution.
 782          */
 783         if (list_empty(&sess->sess_ooo_cmdsn_list))
 784                 list_add_tail(&ooo_cmdsn->ooo_list,
 785                                 &sess->sess_ooo_cmdsn_list);
 786         else {
 787                 ooo_tail = list_entry(sess->sess_ooo_cmdsn_list.prev,
 788                                 typeof(*ooo_tail), ooo_list);
 789                 /*
 790                  * CmdSN is greater than the tail of the list.
 791                  */
 792                 if (iscsi_sna_lt(ooo_tail->cmdsn, ooo_cmdsn->cmdsn))
 793                         list_add_tail(&ooo_cmdsn->ooo_list,
 794                                         &sess->sess_ooo_cmdsn_list);
 795                 else {
 796                         /*
 797                          * CmdSN is either lower than the head,  or somewhere
 798                          * in the middle.
 799                          */
 800                         list_for_each_entry(ooo_tmp, &sess->sess_ooo_cmdsn_list,
 801                                                 ooo_list) {
 802                                 if (iscsi_sna_lt(ooo_tmp->cmdsn, ooo_cmdsn->cmdsn))
 803                                         continue;
 804
 805                                 /* Insert before this entry */
 806                                 list_add(&ooo_cmdsn->ooo_list,
 807                                         ooo_tmp->ooo_list.prev);
 808                                 break;
 809                         }
 810                 }
 811         }
 812
 813         return 0;
 814 }
 815
 816 /*
 817  *      Removes an struct iscsi_ooo_cmdsn from a session's list,
 818  *      called with struct iscsi_session->cmdsn_mutex held.
 819  */
 820 void iscsit_remove_ooo_cmdsn(
 821         struct iscsi_session *sess,
 822         struct iscsi_ooo_cmdsn *ooo_cmdsn)
 823 {
 824         list_del(&ooo_cmdsn->ooo_list);
 825         kmem_cache_free(lio_ooo_cache, ooo_cmdsn);
 826 }
 827
 828 void iscsit_clear_ooo_cmdsns_for_conn(struct iscsi_conn *conn)
 829 {
 830         struct iscsi_ooo_cmdsn *ooo_cmdsn;
 831         struct iscsi_session *sess = conn->sess;
 832
 833         mutex_lock(&sess->cmdsn_mutex);
 834         list_for_each_entry(ooo_cmdsn, &sess->sess_ooo_cmdsn_list, ooo_list) {
 835                 if (ooo_cmdsn->cid != conn->cid)
 836                         continue;
 837
 838                 ooo_cmdsn->cmd = NULL;
 839         }
 840         mutex_unlock(&sess->cmdsn_mutex);
 841 }
 842
 843 int iscsit_execute_ooo_cmdsns(struct iscsi_session *sess)
 844 {
 845         int ooo_count = 0;
 846         struct iscsi_cmd *cmd = NULL;
 847         struct iscsi_ooo_cmdsn *ooo_cmdsn, *ooo_cmdsn_tmp;
 848
 849         lockdep_assert_held(&sess->cmdsn_mutex);
 850
 851         list_for_each_entry_safe(ooo_cmdsn, ooo_cmdsn_tmp,
 852                                 &sess->sess_ooo_cmdsn_list, ooo_list) {
 853                 if (ooo_cmdsn->cmdsn != sess->exp_cmd_sn)
 854                         continue;
 855
 856                 if (!ooo_cmdsn->cmd) {
 857                         sess->exp_cmd_sn++;
 858                         iscsit_remove_ooo_cmdsn(sess, ooo_cmdsn);
 859                         continue;
 860                 }
 861
 862                 cmd = ooo_cmdsn->cmd;
 863                 cmd->i_state = cmd->deferred_i_state;
 864                 ooo_count++;
 865                 sess->exp_cmd_sn++;
 866                 pr_debug("Executing out of order CmdSN: 0x%08x,"
 867                         " incremented ExpCmdSN to 0x%08x.\n",
 868                         cmd->cmd_sn, sess->exp_cmd_sn);
 869
 870                 iscsit_remove_ooo_cmdsn(sess, ooo_cmdsn);
 871
 872                 if (iscsit_execute_cmd(cmd, 1) < 0)
 873                         return -1;
 874
 875                 continue;
 876         }
 877
 878         return ooo_count;
 879 }
 880
 881 /*
 882  *      Called either:
 883  *
 884  *      1. With sess->cmdsn_mutex held from iscsi_execute_ooo_cmdsns()
 885  *      or iscsi_check_received_cmdsn().
 886  *      2. With no locks held directly from iscsi_handle_XXX_pdu() functions
 887  *      for immediate commands.
 888  */
 889 int iscsit_execute_cmd(struct iscsi_cmd *cmd, int ooo)
 890 {
 891         struct se_cmd *se_cmd = &cmd->se_cmd;
 892         struct iscsi_conn *conn = cmd->conn;
 893         int lr = 0;
 894
 895         spin_lock_bh(&cmd->istate_lock);
 896         if (ooo)
 897                 cmd->cmd_flags &= ~ICF_OOO_CMDSN;
 898
 899         switch (cmd->iscsi_opcode) {
 900         case ISCSI_OP_SCSI_CMD:
 901                 /*
 902                  * Go ahead and send the CHECK_CONDITION status for
 903                  * any SCSI CDB exceptions that may have occurred.
 904                  */
 905                 if (cmd->sense_reason) {
 906                         if (cmd->sense_reason == TCM_RESERVATION_CONFLICT) {
 907                                 cmd->i_state = ISTATE_SEND_STATUS;
 908                                 spin_unlock_bh(&cmd->istate_lock);
 909                                 iscsit_add_cmd_to_response_queue(cmd, cmd->conn,
 910                                                 cmd->i_state);
 911                                 return 0;
 912                         }
 913                         spin_unlock_bh(&cmd->istate_lock);
 914                         if (cmd->se_cmd.transport_state & CMD_T_ABORTED)
 915                                 return 0;
 916                         return transport_send_check_condition_and_sense(se_cmd,
 917                                         cmd->sense_reason, 0);
 918                 }
 919                 /*
 920                  * Special case for delayed CmdSN with Immediate
 921                  * Data and/or Unsolicited Data Out attached.
 922                  */
 923                 if (cmd->immediate_data) {
 924                         if (cmd->cmd_flags & ICF_GOT_LAST_DATAOUT) {
 925                                 spin_unlock_bh(&cmd->istate_lock);
 926                                 target_execute_cmd(&cmd->se_cmd);
 927                                 return 0;
 928                         }
 929                         spin_unlock_bh(&cmd->istate_lock);
 930
 931                         if (!(cmd->cmd_flags &
 932                                         ICF_NON_IMMEDIATE_UNSOLICITED_DATA)) {
 933                                 if (cmd->se_cmd.transport_state & CMD_T_ABORTED)
 934                                         return 0;
 935
 936                                 iscsit_set_dataout_sequence_values(cmd);
 937                                 conn->conn_transport->iscsit_get_dataout(conn, cmd, false);
 938                         }
 939                         return 0;
 940                 }
 941                 /*
 942                  * The default handler.
 943                  */
 944                 spin_unlock_bh(&cmd->istate_lock);
 945
 946                 if ((cmd->data_direction == DMA_TO_DEVICE) &&
 947                     !(cmd->cmd_flags & ICF_NON_IMMEDIATE_UNSOLICITED_DATA)) {
 948                         if (cmd->se_cmd.transport_state & CMD_T_ABORTED)
 949                                 return 0;
 950
 951                         iscsit_set_unsolicited_dataout(cmd);
 952                 }
 953                 return transport_handle_cdb_direct(&cmd->se_cmd);
 954
 955         case ISCSI_OP_NOOP_OUT:
 956         case ISCSI_OP_TEXT:
 957                 spin_unlock_bh(&cmd->istate_lock);
 958                 iscsit_add_cmd_to_response_queue(cmd, cmd->conn, cmd->i_state);
 959                 break;
 960         case ISCSI_OP_SCSI_TMFUNC:
 961                 if (cmd->se_cmd.se_tmr_req->response) {
 962                         spin_unlock_bh(&cmd->istate_lock);
 963                         iscsit_add_cmd_to_response_queue(cmd, cmd->conn,
 964                                         cmd->i_state);
 965                         return 0;
 966                 }
 967                 spin_unlock_bh(&cmd->istate_lock);
 968
 969                 return transport_generic_handle_tmr(&cmd->se_cmd);
 970         case ISCSI_OP_LOGOUT:
 971                 spin_unlock_bh(&cmd->istate_lock);
 972                 switch (cmd->logout_reason) {
 973                 case ISCSI_LOGOUT_REASON_CLOSE_SESSION:
 974                         lr = iscsit_logout_closesession(cmd, cmd->conn);
 975                         break;
 976                 case ISCSI_LOGOUT_REASON_CLOSE_CONNECTION:
 977                         lr = iscsit_logout_closeconnection(cmd, cmd->conn);
 978                         break;
 979                 case ISCSI_LOGOUT_REASON_RECOVERY:
 980                         lr = iscsit_logout_removeconnforrecovery(cmd, cmd->conn);
 981                         break;
 982                 default:
 983                         pr_err("Unknown iSCSI Logout Request Code:"
 984                                 " 0x%02x\n", cmd->logout_reason);
 985                         return -1;
 986                 }
 987
 988                 return lr;
 989         default:
 990                 spin_unlock_bh(&cmd->istate_lock);
 991                 pr_err("Cannot perform out of order execution for"
 992                 " unknown iSCSI Opcode: 0x%02x\n", cmd->iscsi_opcode);
 993                 return -1;
 994         }
 995
 996         return 0;
 997 }
 998
 999 void iscsit_free_all_ooo_cmdsns(struct iscsi_session *sess)
1000 {
1001         struct iscsi_ooo_cmdsn *ooo_cmdsn, *ooo_cmdsn_tmp;
1002
1003         mutex_lock(&sess->cmdsn_mutex);
1004         list_for_each_entry_safe(ooo_cmdsn, ooo_cmdsn_tmp,
1005                         &sess->sess_ooo_cmdsn_list, ooo_list) {
1006
1007                 list_del(&ooo_cmdsn->ooo_list);
1008                 kmem_cache_free(lio_ooo_cache, ooo_cmdsn);
1009         }
1010         mutex_unlock(&sess->cmdsn_mutex);
1011 }
1012
1013 int iscsit_handle_ooo_cmdsn(
1014         struct iscsi_session *sess,
1015         struct iscsi_cmd *cmd,
1016         u32 cmdsn)
1017 {
1018         int batch = 0;
1019         struct iscsi_ooo_cmdsn *ooo_cmdsn = NULL, *ooo_tail = NULL;
1020
1021         cmd->deferred_i_state           = cmd->i_state;
1022         cmd->i_state                    = ISTATE_DEFERRED_CMD;
1023         cmd->cmd_flags                  |= ICF_OOO_CMDSN;
1024
1025         if (list_empty(&sess->sess_ooo_cmdsn_list))
1026                 batch = 1;
1027         else {
1028                 ooo_tail = list_entry(sess->sess_ooo_cmdsn_list.prev,
1029                                 typeof(*ooo_tail), ooo_list);
1030                 if (ooo_tail->cmdsn != (cmdsn - 1))
1031                         batch = 1;
1032         }
1033
1034         ooo_cmdsn = iscsit_allocate_ooo_cmdsn();
1035         if (!ooo_cmdsn)
1036                 return -ENOMEM;
1037
1038         ooo_cmdsn->cmd                  = cmd;
1039         ooo_cmdsn->batch_count          = (batch) ?
1040                                           (cmdsn - sess->exp_cmd_sn) : 1;
1041         ooo_cmdsn->cid                  = cmd->conn->cid;
1042         ooo_cmdsn->exp_cmdsn            = sess->exp_cmd_sn;
1043         ooo_cmdsn->cmdsn                = cmdsn;
1044
1045         if (iscsit_attach_ooo_cmdsn(sess, ooo_cmdsn) < 0) {
1046                 kmem_cache_free(lio_ooo_cache, ooo_cmdsn);
1047                 return -ENOMEM;
1048         }
1049
1050         return 0;
1051 }
1052
1053 static int iscsit_set_dataout_timeout_values(
1054         struct iscsi_cmd *cmd,
1055         u32 *offset,
1056         u32 *length)
1057 {
1058         struct iscsi_conn *conn = cmd->conn;
1059         struct iscsi_r2t *r2t;
1060
1061         if (cmd->unsolicited_data) {
1062                 *offset = 0;
1063                 *length = (conn->sess->sess_ops->FirstBurstLength >
1064                            cmd->se_cmd.data_length) ?
1065                            cmd->se_cmd.data_length :
1066                            conn->sess->sess_ops->FirstBurstLength;
1067                 return 0;
1068         }
1069
1070         spin_lock_bh(&cmd->r2t_lock);
1071         if (list_empty(&cmd->cmd_r2t_list)) {
1072                 pr_err("cmd->cmd_r2t_list is empty!\n");
1073                 spin_unlock_bh(&cmd->r2t_lock);
1074                 return -1;
1075         }
1076
1077         list_for_each_entry(r2t, &cmd->cmd_r2t_list, r2t_list) {
1078                 if (r2t->sent_r2t && !r2t->recovery_r2t && !r2t->seq_complete) {
1079                         *offset = r2t->offset;
1080                         *length = r2t->xfer_len;
1081                         spin_unlock_bh(&cmd->r2t_lock);
1082                         return 0;
1083                 }
1084         }
1085         spin_unlock_bh(&cmd->r2t_lock);
1086
1087         pr_err("Unable to locate any incomplete DataOUT"
1088                 " sequences for ITT: 0x%08x.\n", cmd->init_task_tag);
1089
1090         return -1;
1091 }
1092
1093 /*
1094  *      NOTE: Called from interrupt (timer) context.
1095  */
1096 void iscsit_handle_dataout_timeout(struct timer_list *t)
1097 {
1098         u32 pdu_length = 0, pdu_offset = 0;
1099         u32 r2t_length = 0, r2t_offset = 0;
1100         struct iscsi_cmd *cmd = from_timer(cmd, t, dataout_timer);
1101         struct iscsi_conn *conn = cmd->conn;
1102         struct iscsi_session *sess = NULL;
1103         struct iscsi_node_attrib *na;
1104
1105         iscsit_inc_conn_usage_count(conn);
1106
1107         spin_lock_bh(&cmd->dataout_timeout_lock);
1108         if (cmd->dataout_timer_flags & ISCSI_TF_STOP) {
1109                 spin_unlock_bh(&cmd->dataout_timeout_lock);
1110                 iscsit_dec_conn_usage_count(conn);
1111                 return;
1112         }
1113         cmd->dataout_timer_flags &= ~ISCSI_TF_RUNNING;
1114         sess = conn->sess;
1115         na = iscsit_tpg_get_node_attrib(sess);
1116
1117         if (!sess->sess_ops->ErrorRecoveryLevel) {
1118                 pr_err("Unable to recover from DataOut timeout while"
1119                         " in ERL=0, closing iSCSI connection for I_T Nexus"
1120                         " %s,i,0x%6phN,%s,t,0x%02x\n",
1121                         sess->sess_ops->InitiatorName, sess->isid,
1122                         sess->tpg->tpg_tiqn->tiqn, (u32)sess->tpg->tpgt);
1123                 goto failure;
1124         }
1125
1126         if (++cmd->dataout_timeout_retries == na->dataout_timeout_retries) {
1127                 pr_err("Command ITT: 0x%08x exceeded max retries"
1128                         " for DataOUT timeout %u, closing iSCSI connection for"
1129                         " I_T Nexus %s,i,0x%6phN,%s,t,0x%02x\n",
1130                         cmd->init_task_tag, na->dataout_timeout_retries,
1131                         sess->sess_ops->InitiatorName, sess->isid,
1132                         sess->tpg->tpg_tiqn->tiqn, (u32)sess->tpg->tpgt);
1133                 goto failure;
1134         }
1135
1136         cmd->cmd_flags |= ICF_WITHIN_COMMAND_RECOVERY;
1137
1138         if (conn->sess->sess_ops->DataSequenceInOrder) {
1139                 if (conn->sess->sess_ops->DataPDUInOrder) {
1140                         pdu_offset = cmd->write_data_done;
1141                         if ((pdu_offset + (conn->sess->sess_ops->MaxBurstLength -
1142                              cmd->next_burst_len)) > cmd->se_cmd.data_length)
1143                                 pdu_length = (cmd->se_cmd.data_length -
1144                                         cmd->write_data_done);
1145                         else
1146                                 pdu_length = (conn->sess->sess_ops->MaxBurstLength -
1147                                                 cmd->next_burst_len);
1148                 } else {
1149                         pdu_offset = cmd->seq_start_offset;
1150                         pdu_length = (cmd->seq_end_offset -
1151                                 cmd->seq_start_offset);
1152                 }
1153         } else {
1154                 if (iscsit_set_dataout_timeout_values(cmd, &pdu_offset,
1155                                 &pdu_length) < 0)
1156                         goto failure;
1157         }
1158
1159         if (iscsit_recalculate_dataout_values(cmd, pdu_offset, pdu_length,
1160                         &r2t_offset, &r2t_length) < 0)
1161                 goto failure;
1162
1163         pr_debug("Command ITT: 0x%08x timed out waiting for"
1164                 " completion of %sDataOUT Sequence Offset: %u, Length: %u\n",
1165                 cmd->init_task_tag, (cmd->unsolicited_data) ? "Unsolicited " :
1166                 "", r2t_offset, r2t_length);
1167
1168         if (iscsit_send_recovery_r2t(cmd, r2t_offset, r2t_length) < 0)
1169                 goto failure;
1170
1171         iscsit_start_dataout_timer(cmd, conn);
1172         spin_unlock_bh(&cmd->dataout_timeout_lock);
1173         iscsit_dec_conn_usage_count(conn);
1174
1175         return;
1176
1177 failure:
1178         spin_unlock_bh(&cmd->dataout_timeout_lock);
1179         iscsit_fill_cxn_timeout_err_stats(sess);
1180         iscsit_cause_connection_reinstatement(conn, 0);
1181         iscsit_dec_conn_usage_count(conn);
1182 }
1183
1184 void iscsit_mod_dataout_timer(struct iscsi_cmd *cmd)
1185 {
1186         struct iscsi_conn *conn = cmd->conn;
1187         struct iscsi_session *sess = conn->sess;
1188         struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
1189
1190         spin_lock_bh(&cmd->dataout_timeout_lock);
1191         if (!(cmd->dataout_timer_flags & ISCSI_TF_RUNNING)) {
1192                 spin_unlock_bh(&cmd->dataout_timeout_lock);
1193                 return;
1194         }
1195
1196         mod_timer(&cmd->dataout_timer,
1197                 (get_jiffies_64() + na->dataout_timeout * HZ));
1198         pr_debug("Updated DataOUT timer for ITT: 0x%08x",
1199                         cmd->init_task_tag);
1200         spin_unlock_bh(&cmd->dataout_timeout_lock);
1201 }
1202
1203 void iscsit_start_dataout_timer(
1204         struct iscsi_cmd *cmd,
1205         struct iscsi_conn *conn)
1206 {
1207         struct iscsi_session *sess = conn->sess;
1208         struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
1209
1210         lockdep_assert_held(&cmd->dataout_timeout_lock);
1211
1212         if (cmd->dataout_timer_flags & ISCSI_TF_RUNNING)
1213                 return;
1214
1215         pr_debug("Starting DataOUT timer for ITT: 0x%08x on"
1216                 " CID: %hu.\n", cmd->init_task_tag, conn->cid);
1217
1218         cmd->dataout_timer_flags &= ~ISCSI_TF_STOP;
1219         cmd->dataout_timer_flags |= ISCSI_TF_RUNNING;
1220         mod_timer(&cmd->dataout_timer, jiffies + na->dataout_timeout * HZ);
1221 }
1222
1223 void iscsit_stop_dataout_timer(struct iscsi_cmd *cmd)
1224 {
1225         spin_lock_bh(&cmd->dataout_timeout_lock);
1226         if (!(cmd->dataout_timer_flags & ISCSI_TF_RUNNING)) {
1227                 spin_unlock_bh(&cmd->dataout_timeout_lock);
1228                 return;
1229         }
1230         cmd->dataout_timer_flags |= ISCSI_TF_STOP;
1231         spin_unlock_bh(&cmd->dataout_timeout_lock);
1232
1233         del_timer_sync(&cmd->dataout_timer);
1234
1235         spin_lock_bh(&cmd->dataout_timeout_lock);
1236         cmd->dataout_timer_flags &= ~ISCSI_TF_RUNNING;
1237         pr_debug("Stopped DataOUT Timer for ITT: 0x%08x\n",
1238                         cmd->init_task_tag);
1239         spin_unlock_bh(&cmd->dataout_timeout_lock);
1240 }
1241 EXPORT_SYMBOL(iscsit_stop_dataout_timer);