drivers/target/iscsi/iscsi_target_erl1.c

   1 /*******************************************************************************
   2  * This file contains error recovery level one used by the iSCSI Target driver.
   3  *
   4  * \u00a9 Copyright 2007-2011 RisingTide Systems LLC.
   5  *
   6  * Licensed to the Linux Foundation under the General Public License (GPL) version 2.
   7  *
   8  * Author: Nicholas A. Bellinger <nab@linux-iscsi.org>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  ******************************************************************************/
  20
  21 #include <linux/list.h>
  22 #include <scsi/iscsi_proto.h>
  23 #include <target/target_core_base.h>
  24 #include <target/target_core_fabric.h>
  25
  26 #include "iscsi_target_core.h"
  27 #include "iscsi_target_seq_pdu_list.h"
  28 #include "iscsi_target_datain_values.h"
  29 #include "iscsi_target_device.h"
  30 #include "iscsi_target_tpg.h"
  31 #include "iscsi_target_util.h"
  32 #include "iscsi_target_erl0.h"
  33 #include "iscsi_target_erl1.h"
  34 #include "iscsi_target_erl2.h"
  35 #include "iscsi_target.h"
  36
  37 #define OFFLOAD_BUF_SIZE        32768
  38
  39 /*
  40  *      Used to dump excess datain payload for certain error recovery
  41  *      situations.  Receive in OFFLOAD_BUF_SIZE max of datain per rx_data().
  42  *
  43  *      dump_padding_digest denotes if padding and data digests need
  44  *      to be dumped.
  45  */
  46 int iscsit_dump_data_payload(
  47         struct iscsi_conn *conn,
  48         u32 buf_len,
  49         int dump_padding_digest)
  50 {
  51         char *buf, pad_bytes[4];
  52         int ret = DATAOUT_WITHIN_COMMAND_RECOVERY, rx_got;
  53         u32 length, padding, offset = 0, size;
  54         struct kvec iov;
  55
  56         length = (buf_len > OFFLOAD_BUF_SIZE) ? OFFLOAD_BUF_SIZE : buf_len;
  57
  58         buf = kzalloc(length, GFP_ATOMIC);
  59         if (!buf) {
  60                 pr_err("Unable to allocate %u bytes for offload"
  61                                 " buffer.\n", length);
  62                 return -1;
  63         }
  64         memset(&iov, 0, sizeof(struct kvec));
  65
  66         while (offset < buf_len) {
  67                 size = ((offset + length) > buf_len) ?
  68                         (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                         goto out;
  77                 }
  78
  79                 offset += size;
  80         }
  81
  82         if (!dump_padding_digest)
  83                 goto out;
  84
  85         padding = ((-buf_len) & 3);
  86         if (padding != 0) {
  87                 iov.iov_len = padding;
  88                 iov.iov_base = pad_bytes;
  89
  90                 rx_got = rx_data(conn, &iov, 1, padding);
  91                 if (rx_got != padding) {
  92                         ret = DATAOUT_CANNOT_RECOVER;
  93                         goto out;
  94                 }
  95         }
  96
  97         if (conn->conn_ops->DataDigest) {
  98                 u32 data_crc;
  99
 100                 iov.iov_len = ISCSI_CRC_LEN;
 101                 iov.iov_base = &data_crc;
 102
 103                 rx_got = rx_data(conn, &iov, 1, ISCSI_CRC_LEN);
 104                 if (rx_got != ISCSI_CRC_LEN) {
 105                         ret = DATAOUT_CANNOT_RECOVER;
 106                         goto out;
 107                 }
 108         }
 109
 110 out:
 111         kfree(buf);
 112         return ret;
 113 }
 114
 115 /*
 116  *      Used for retransmitting R2Ts from a R2T SNACK request.
 117  */
 118 static int iscsit_send_recovery_r2t_for_snack(
 119         struct iscsi_cmd *cmd,
 120         struct iscsi_r2t *r2t)
 121 {
 122         /*
 123          * If the struct iscsi_r2t has not been sent yet, we can safely
 124          * ignore retransmission
 125          * of the R2TSN in question.
 126          */
 127         spin_lock_bh(&cmd->r2t_lock);
 128         if (!r2t->sent_r2t) {
 129                 spin_unlock_bh(&cmd->r2t_lock);
 130                 return 0;
 131         }
 132         r2t->sent_r2t = 0;
 133         spin_unlock_bh(&cmd->r2t_lock);
 134
 135         iscsit_add_cmd_to_immediate_queue(cmd, cmd->conn, ISTATE_SEND_R2T);
 136
 137         return 0;
 138 }
 139
 140 static int iscsit_handle_r2t_snack(
 141         struct iscsi_cmd *cmd,
 142         unsigned char *buf,
 143         u32 begrun,
 144         u32 runlength)
 145 {
 146         u32 last_r2tsn;
 147         struct iscsi_r2t *r2t;
 148
 149         /*
 150          * Make sure the initiator is not requesting retransmission
 151          * of R2TSNs already acknowledged by a TMR TASK_REASSIGN.
 152          */
 153         if ((cmd->cmd_flags & ICF_GOT_DATACK_SNACK) &&
 154             (begrun <= cmd->acked_data_sn)) {
 155                 pr_err("ITT: 0x%08x, R2T SNACK requesting"
 156                         " retransmission of R2TSN: 0x%08x to 0x%08x but already"
 157                         " acked to  R2TSN: 0x%08x by TMR TASK_REASSIGN,"
 158                         " protocol error.\n", cmd->init_task_tag, begrun,
 159                         (begrun + runlength), cmd->acked_data_sn);
 160
 161                         return iscsit_add_reject_from_cmd(
 162                                         ISCSI_REASON_PROTOCOL_ERROR,
 163                                         1, 0, buf, cmd);
 164         }
 165
 166         if (runlength) {
 167                 if ((begrun + runlength) > cmd->r2t_sn) {
 168                         pr_err("Command ITT: 0x%08x received R2T SNACK"
 169                         " with BegRun: 0x%08x, RunLength: 0x%08x, exceeds"
 170                         " current R2TSN: 0x%08x, protocol error.\n",
 171                         cmd->init_task_tag, begrun, runlength, cmd->r2t_sn);
 172                         return iscsit_add_reject_from_cmd(
 173                                 ISCSI_REASON_BOOKMARK_INVALID, 1, 0, buf, cmd);
 174                 }
 175                 last_r2tsn = (begrun + runlength);
 176         } else
 177                 last_r2tsn = cmd->r2t_sn;
 178
 179         while (begrun < last_r2tsn) {
 180                 r2t = iscsit_get_holder_for_r2tsn(cmd, begrun);
 181                 if (!r2t)
 182                         return -1;
 183                 if (iscsit_send_recovery_r2t_for_snack(cmd, r2t) < 0)
 184                         return -1;
 185
 186                 begrun++;
 187         }
 188
 189         return 0;
 190 }
 191
 192 /*
 193  *      Generates Offsets and NextBurstLength based on Begrun and Runlength
 194  *      carried in a Data SNACK or ExpDataSN in TMR TASK_REASSIGN.
 195  *
 196  *      For DataSequenceInOrder=Yes and DataPDUInOrder=[Yes,No] only.
 197  *
 198  *      FIXME: How is this handled for a RData SNACK?
 199  */
 200 int iscsit_create_recovery_datain_values_datasequenceinorder_yes(
 201         struct iscsi_cmd *cmd,
 202         struct iscsi_datain_req *dr)
 203 {
 204         u32 data_sn = 0, data_sn_count = 0;
 205         u32 pdu_start = 0, seq_no = 0;
 206         u32 begrun = dr->begrun;
 207         struct iscsi_conn *conn = cmd->conn;
 208
 209         while (begrun > data_sn++) {
 210                 data_sn_count++;
 211                 if ((dr->next_burst_len +
 212                      conn->conn_ops->MaxRecvDataSegmentLength) <
 213                      conn->sess->sess_ops->MaxBurstLength) {
 214                         dr->read_data_done +=
 215                                 conn->conn_ops->MaxRecvDataSegmentLength;
 216                         dr->next_burst_len +=
 217                                 conn->conn_ops->MaxRecvDataSegmentLength;
 218                 } else {
 219                         dr->read_data_done +=
 220                                 (conn->sess->sess_ops->MaxBurstLength -
 221                                  dr->next_burst_len);
 222                         dr->next_burst_len = 0;
 223                         pdu_start += data_sn_count;
 224                         data_sn_count = 0;
 225                         seq_no++;
 226                 }
 227         }
 228
 229         if (!conn->sess->sess_ops->DataPDUInOrder) {
 230                 cmd->seq_no = seq_no;
 231                 cmd->pdu_start = pdu_start;
 232                 cmd->pdu_send_order = data_sn_count;
 233         }
 234
 235         return 0;
 236 }
 237
 238 /*
 239  *      Generates Offsets and NextBurstLength based on Begrun and Runlength
 240  *      carried in a Data SNACK or ExpDataSN in TMR TASK_REASSIGN.
 241  *
 242  *      For DataSequenceInOrder=No and DataPDUInOrder=[Yes,No] only.
 243  *
 244  *      FIXME: How is this handled for a RData SNACK?
 245  */
 246 int iscsit_create_recovery_datain_values_datasequenceinorder_no(
 247         struct iscsi_cmd *cmd,
 248         struct iscsi_datain_req *dr)
 249 {
 250         int found_seq = 0, i;
 251         u32 data_sn, read_data_done = 0, seq_send_order = 0;
 252         u32 begrun = dr->begrun;
 253         u32 runlength = dr->runlength;
 254         struct iscsi_conn *conn = cmd->conn;
 255         struct iscsi_seq *first_seq = NULL, *seq = NULL;
 256
 257         if (!cmd->seq_list) {
 258                 pr_err("struct iscsi_cmd->seq_list is NULL!\n");
 259                 return -1;
 260         }
 261
 262         /*
 263          * Calculate read_data_done for all sequences containing a
 264          * first_datasn and last_datasn less than the BegRun.
 265          *
 266          * Locate the struct iscsi_seq the BegRun lies within and calculate
 267          * NextBurstLenghth up to the DataSN based on MaxRecvDataSegmentLength.
 268          *
 269          * Also use struct iscsi_seq->seq_send_order to determine where to start.
 270          */
 271         for (i = 0; i < cmd->seq_count; i++) {
 272                 seq = &cmd->seq_list[i];
 273
 274                 if (!seq->seq_send_order)
 275                         first_seq = seq;
 276
 277                 /*
 278                  * No data has been transferred for this DataIN sequence, so the
 279                  * seq->first_datasn and seq->last_datasn have not been set.
 280                  */
 281                 if (!seq->sent) {
 282                         pr_err("Ignoring non-sent sequence 0x%08x ->"
 283                                 " 0x%08x\n\n", seq->first_datasn,
 284                                 seq->last_datasn);
 285                         continue;
 286                 }
 287
 288                 /*
 289                  * This DataIN sequence is precedes the received BegRun, add the
 290                  * total xfer_len of the sequence to read_data_done and reset
 291                  * seq->pdu_send_order.
 292                  */
 293                 if ((seq->first_datasn < begrun) &&
 294                                 (seq->last_datasn < begrun)) {
 295                         pr_err("Pre BegRun sequence 0x%08x ->"
 296                                 " 0x%08x\n", seq->first_datasn,
 297                                 seq->last_datasn);
 298
 299                         read_data_done += cmd->seq_list[i].xfer_len;
 300                         seq->next_burst_len = seq->pdu_send_order = 0;
 301                         continue;
 302                 }
 303
 304                 /*
 305                  * The BegRun lies within this DataIN sequence.
 306                  */
 307                 if ((seq->first_datasn <= begrun) &&
 308                                 (seq->last_datasn >= begrun)) {
 309                         pr_err("Found sequence begrun: 0x%08x in"
 310                                 " 0x%08x -> 0x%08x\n", begrun,
 311                                 seq->first_datasn, seq->last_datasn);
 312
 313                         seq_send_order = seq->seq_send_order;
 314                         data_sn = seq->first_datasn;
 315                         seq->next_burst_len = seq->pdu_send_order = 0;
 316                         found_seq = 1;
 317
 318                         /*
 319                          * For DataPDUInOrder=Yes, while the first DataSN of
 320                          * the sequence is less than the received BegRun, add
 321                          * the MaxRecvDataSegmentLength to read_data_done and
 322                          * to the sequence's next_burst_len;
 323                          *
 324                          * For DataPDUInOrder=No, while the first DataSN of the
 325                          * sequence is less than the received BegRun, find the
 326                          * struct iscsi_pdu of the DataSN in question and add the
 327                          * MaxRecvDataSegmentLength to read_data_done and to the
 328                          * sequence's next_burst_len;
 329                          */
 330                         if (conn->sess->sess_ops->DataPDUInOrder) {
 331                                 while (data_sn < begrun) {
 332                                         seq->pdu_send_order++;
 333                                         read_data_done +=
 334                                                 conn->conn_ops->MaxRecvDataSegmentLength;
 335                                         seq->next_burst_len +=
 336                                                 conn->conn_ops->MaxRecvDataSegmentLength;
 337                                         data_sn++;
 338                                 }
 339                         } else {
 340                                 int j;
 341                                 struct iscsi_pdu *pdu;
 342
 343                                 while (data_sn < begrun) {
 344                                         seq->pdu_send_order++;
 345
 346                                         for (j = 0; j < seq->pdu_count; j++) {
 347                                                 pdu = &cmd->pdu_list[
 348                                                         seq->pdu_start + j];
 349                                                 if (pdu->data_sn == data_sn) {
 350                                                         read_data_done +=
 351                                                                 pdu->length;
 352                                                         seq->next_burst_len +=
 353                                                                 pdu->length;
 354                                                 }
 355                                         }
 356                                         data_sn++;
 357                                 }
 358                         }
 359                         continue;
 360                 }
 361
 362                 /*
 363                  * This DataIN sequence is larger than the received BegRun,
 364                  * reset seq->pdu_send_order and continue.
 365                  */
 366                 if ((seq->first_datasn > begrun) ||
 367                                 (seq->last_datasn > begrun)) {
 368                         pr_err("Post BegRun sequence 0x%08x -> 0x%08x\n",
 369                                         seq->first_datasn, seq->last_datasn);
 370
 371                         seq->next_burst_len = seq->pdu_send_order = 0;
 372                         continue;
 373                 }
 374         }
 375
 376         if (!found_seq) {
 377                 if (!begrun) {
 378                         if (!first_seq) {
 379                                 pr_err("ITT: 0x%08x, Begrun: 0x%08x"
 380                                         " but first_seq is NULL\n",
 381                                         cmd->init_task_tag, begrun);
 382                                 return -1;
 383                         }
 384                         seq_send_order = first_seq->seq_send_order;
 385                         seq->next_burst_len = seq->pdu_send_order = 0;
 386                         goto done;
 387                 }
 388
 389                 pr_err("Unable to locate struct iscsi_seq for ITT: 0x%08x,"
 390                         " BegRun: 0x%08x, RunLength: 0x%08x while"
 391                         " DataSequenceInOrder=No and DataPDUInOrder=%s.\n",
 392                                 cmd->init_task_tag, begrun, runlength,
 393                         (conn->sess->sess_ops->DataPDUInOrder) ? "Yes" : "No");
 394                 return -1;
 395         }
 396
 397 done:
 398         dr->read_data_done = read_data_done;
 399         dr->seq_send_order = seq_send_order;
 400
 401         return 0;
 402 }
 403
 404 static int iscsit_handle_recovery_datain(
 405         struct iscsi_cmd *cmd,
 406         unsigned char *buf,
 407         u32 begrun,
 408         u32 runlength)
 409 {
 410         struct iscsi_conn *conn = cmd->conn;
 411         struct iscsi_datain_req *dr;
 412         struct se_cmd *se_cmd = &cmd->se_cmd;
 413
 414         if (!(se_cmd->transport_state & CMD_T_COMPLETE)) {
 415                 pr_err("Ignoring ITT: 0x%08x Data SNACK\n",
 416                                 cmd->init_task_tag);
 417                 return 0;
 418         }
 419
 420         /*
 421          * Make sure the initiator is not requesting retransmission
 422          * of DataSNs already acknowledged by a Data ACK SNACK.
 423          */
 424         if ((cmd->cmd_flags & ICF_GOT_DATACK_SNACK) &&
 425             (begrun <= cmd->acked_data_sn)) {
 426                 pr_err("ITT: 0x%08x, Data SNACK requesting"
 427                         " retransmission of DataSN: 0x%08x to 0x%08x but"
 428                         " already acked to DataSN: 0x%08x by Data ACK SNACK,"
 429                         " protocol error.\n", cmd->init_task_tag, begrun,
 430                         (begrun + runlength), cmd->acked_data_sn);
 431
 432                 return iscsit_add_reject_from_cmd(ISCSI_REASON_PROTOCOL_ERROR,
 433                                 1, 0, buf, cmd);
 434         }
 435
 436         /*
 437          * Make sure BegRun and RunLength in the Data SNACK are sane.
 438          * Note: (cmd->data_sn - 1) will carry the maximum DataSN sent.
 439          */
 440         if ((begrun + runlength) > (cmd->data_sn - 1)) {
 441                 pr_err("Initiator requesting BegRun: 0x%08x, RunLength"
 442                         ": 0x%08x greater than maximum DataSN: 0x%08x.\n",
 443                                 begrun, runlength, (cmd->data_sn - 1));
 444                 return iscsit_add_reject_from_cmd(ISCSI_REASON_BOOKMARK_INVALID,
 445                                 1, 0, buf, cmd);
 446         }
 447
 448         dr = iscsit_allocate_datain_req();
 449         if (!dr)
 450                 return iscsit_add_reject_from_cmd(ISCSI_REASON_BOOKMARK_NO_RESOURCES,
 451                                 1, 0, buf, cmd);
 452
 453         dr->data_sn = dr->begrun = begrun;
 454         dr->runlength = runlength;
 455         dr->generate_recovery_values = 1;
 456         dr->recovery = DATAIN_WITHIN_COMMAND_RECOVERY;
 457
 458         iscsit_attach_datain_req(cmd, dr);
 459
 460         cmd->i_state = ISTATE_SEND_DATAIN;
 461         iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
 462
 463         return 0;
 464 }
 465
 466 int iscsit_handle_recovery_datain_or_r2t(
 467         struct iscsi_conn *conn,
 468         unsigned char *buf,
 469         itt_t init_task_tag,
 470         u32 targ_xfer_tag,
 471         u32 begrun,
 472         u32 runlength)
 473 {
 474         struct iscsi_cmd *cmd;
 475
 476         cmd = iscsit_find_cmd_from_itt(conn, init_task_tag);
 477         if (!cmd)
 478                 return 0;
 479
 480         /*
 481          * FIXME: This will not work for bidi commands.
 482          */
 483         switch (cmd->data_direction) {
 484         case DMA_TO_DEVICE:
 485                 return iscsit_handle_r2t_snack(cmd, buf, begrun, runlength);
 486         case DMA_FROM_DEVICE:
 487                 return iscsit_handle_recovery_datain(cmd, buf, begrun,
 488                                 runlength);
 489         default:
 490                 pr_err("Unknown cmd->data_direction: 0x%02x\n",
 491                                 cmd->data_direction);
 492                 return -1;
 493         }
 494
 495         return 0;
 496 }
 497
 498 /* #warning FIXME: Status SNACK needs to be dependent on OPCODE!!! */
 499 int iscsit_handle_status_snack(
 500         struct iscsi_conn *conn,
 501         itt_t init_task_tag,
 502         u32 targ_xfer_tag,
 503         u32 begrun,
 504         u32 runlength)
 505 {
 506         struct iscsi_cmd *cmd = NULL;
 507         u32 last_statsn;
 508         int found_cmd;
 509
 510         if (conn->exp_statsn > begrun) {
 511                 pr_err("Got Status SNACK Begrun: 0x%08x, RunLength:"
 512                         " 0x%08x but already got ExpStatSN: 0x%08x on CID:"
 513                         " %hu.\n", begrun, runlength, conn->exp_statsn,
 514                         conn->cid);
 515                 return 0;
 516         }
 517
 518         last_statsn = (!runlength) ? conn->stat_sn : (begrun + runlength);
 519
 520         while (begrun < last_statsn) {
 521                 found_cmd = 0;
 522
 523                 spin_lock_bh(&conn->cmd_lock);
 524                 list_for_each_entry(cmd, &conn->conn_cmd_list, i_conn_node) {
 525                         if (cmd->stat_sn == begrun) {
 526                                 found_cmd = 1;
 527                                 break;
 528                         }
 529                 }
 530                 spin_unlock_bh(&conn->cmd_lock);
 531
 532                 if (!found_cmd) {
 533                         pr_err("Unable to find StatSN: 0x%08x for"
 534                                 " a Status SNACK, assuming this was a"
 535                                 " protactic SNACK for an untransmitted"
 536                                 " StatSN, ignoring.\n", begrun);
 537                         begrun++;
 538                         continue;
 539                 }
 540
 541                 spin_lock_bh(&cmd->istate_lock);
 542                 if (cmd->i_state == ISTATE_SEND_DATAIN) {
 543                         spin_unlock_bh(&cmd->istate_lock);
 544                         pr_err("Ignoring Status SNACK for BegRun:"
 545                                 " 0x%08x, RunLength: 0x%08x, assuming this was"
 546                                 " a protactic SNACK for an untransmitted"
 547                                 " StatSN\n", begrun, runlength);
 548                         begrun++;
 549                         continue;
 550                 }
 551                 spin_unlock_bh(&cmd->istate_lock);
 552
 553                 cmd->i_state = ISTATE_SEND_STATUS_RECOVERY;
 554                 iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
 555                 begrun++;
 556         }
 557
 558         return 0;
 559 }
 560
 561 int iscsit_handle_data_ack(
 562         struct iscsi_conn *conn,
 563         u32 targ_xfer_tag,
 564         u32 begrun,
 565         u32 runlength)
 566 {
 567         struct iscsi_cmd *cmd = NULL;
 568
 569         cmd = iscsit_find_cmd_from_ttt(conn, targ_xfer_tag);
 570         if (!cmd) {
 571                 pr_err("Data ACK SNACK for TTT: 0x%08x is"
 572                         " invalid.\n", targ_xfer_tag);
 573                 return -1;
 574         }
 575
 576         if (begrun <= cmd->acked_data_sn) {
 577                 pr_err("ITT: 0x%08x Data ACK SNACK BegRUN: 0x%08x is"
 578                         " less than the already acked DataSN: 0x%08x.\n",
 579                         cmd->init_task_tag, begrun, cmd->acked_data_sn);
 580                 return -1;
 581         }
 582
 583         /*
 584          * For Data ACK SNACK, BegRun is the next expected DataSN.
 585          * (see iSCSI v19: 10.16.6)
 586          */
 587         cmd->cmd_flags |= ICF_GOT_DATACK_SNACK;
 588         cmd->acked_data_sn = (begrun - 1);
 589
 590         pr_debug("Received Data ACK SNACK for ITT: 0x%08x,"
 591                 " updated acked DataSN to 0x%08x.\n",
 592                         cmd->init_task_tag, cmd->acked_data_sn);
 593
 594         return 0;
 595 }
 596
 597 static int iscsit_send_recovery_r2t(
 598         struct iscsi_cmd *cmd,
 599         u32 offset,
 600         u32 xfer_len)
 601 {
 602         int ret;
 603
 604         spin_lock_bh(&cmd->r2t_lock);
 605         ret = iscsit_add_r2t_to_list(cmd, offset, xfer_len, 1, 0);
 606         spin_unlock_bh(&cmd->r2t_lock);
 607
 608         return ret;
 609 }
 610
 611 int iscsit_dataout_datapduinorder_no_fbit(
 612         struct iscsi_cmd *cmd,
 613         struct iscsi_pdu *pdu)
 614 {
 615         int i, send_recovery_r2t = 0, recovery = 0;
 616         u32 length = 0, offset = 0, pdu_count = 0, xfer_len = 0;
 617         struct iscsi_conn *conn = cmd->conn;
 618         struct iscsi_pdu *first_pdu = NULL;
 619
 620         /*
 621          * Get an struct iscsi_pdu pointer to the first PDU, and total PDU count
 622          * of the DataOUT sequence.
 623          */
 624         if (conn->sess->sess_ops->DataSequenceInOrder) {
 625                 for (i = 0; i < cmd->pdu_count; i++) {
 626                         if (cmd->pdu_list[i].seq_no == pdu->seq_no) {
 627                                 if (!first_pdu)
 628                                         first_pdu = &cmd->pdu_list[i];
 629                                  xfer_len += cmd->pdu_list[i].length;
 630                                  pdu_count++;
 631                         } else if (pdu_count)
 632                                 break;
 633                 }
 634         } else {
 635                 struct iscsi_seq *seq = cmd->seq_ptr;
 636
 637                 first_pdu = &cmd->pdu_list[seq->pdu_start];
 638                 pdu_count = seq->pdu_count;
 639         }
 640
 641         if (!first_pdu || !pdu_count)
 642                 return DATAOUT_CANNOT_RECOVER;
 643
 644         /*
 645          * Loop through the ending DataOUT Sequence checking each struct iscsi_pdu.
 646          * The following ugly logic does batching of not received PDUs.
 647          */
 648         for (i = 0; i < pdu_count; i++) {
 649                 if (first_pdu[i].status == ISCSI_PDU_RECEIVED_OK) {
 650                         if (!send_recovery_r2t)
 651                                 continue;
 652
 653                         if (iscsit_send_recovery_r2t(cmd, offset, length) < 0)
 654                                 return DATAOUT_CANNOT_RECOVER;
 655
 656                         send_recovery_r2t = length = offset = 0;
 657                         continue;
 658                 }
 659                 /*
 660                  * Set recovery = 1 for any missing, CRC failed, or timed
 661                  * out PDUs to let the DataOUT logic know that this sequence
 662                  * has not been completed yet.
 663                  *
 664                  * Also, only send a Recovery R2T for ISCSI_PDU_NOT_RECEIVED.
 665                  * We assume if the PDU either failed CRC or timed out
 666                  * that a Recovery R2T has already been sent.
 667                  */
 668                 recovery = 1;
 669
 670                 if (first_pdu[i].status != ISCSI_PDU_NOT_RECEIVED)
 671                         continue;
 672
 673                 if (!offset)
 674                         offset = first_pdu[i].offset;
 675                 length += first_pdu[i].length;
 676
 677                 send_recovery_r2t = 1;
 678         }
 679
 680         if (send_recovery_r2t)
 681                 if (iscsit_send_recovery_r2t(cmd, offset, length) < 0)
 682                         return DATAOUT_CANNOT_RECOVER;
 683
 684         return (!recovery) ? DATAOUT_NORMAL : DATAOUT_WITHIN_COMMAND_RECOVERY;
 685 }
 686
 687 static int iscsit_recalculate_dataout_values(
 688         struct iscsi_cmd *cmd,
 689         u32 pdu_offset,
 690         u32 pdu_length,
 691         u32 *r2t_offset,
 692         u32 *r2t_length)
 693 {
 694         int i;
 695         struct iscsi_conn *conn = cmd->conn;
 696         struct iscsi_pdu *pdu = NULL;
 697
 698         if (conn->sess->sess_ops->DataSequenceInOrder) {
 699                 cmd->data_sn = 0;
 700
 701                 if (conn->sess->sess_ops->DataPDUInOrder) {
 702                         *r2t_offset = cmd->write_data_done;
 703                         *r2t_length = (cmd->seq_end_offset -
 704                                         cmd->write_data_done);
 705                         return 0;
 706                 }
 707
 708                 *r2t_offset = cmd->seq_start_offset;
 709                 *r2t_length = (cmd->seq_end_offset - cmd->seq_start_offset);
 710
 711                 for (i = 0; i < cmd->pdu_count; i++) {
 712                         pdu = &cmd->pdu_list[i];
 713
 714                         if (pdu->status != ISCSI_PDU_RECEIVED_OK)
 715                                 continue;
 716
 717                         if ((pdu->offset >= cmd->seq_start_offset) &&
 718                            ((pdu->offset + pdu->length) <=
 719                              cmd->seq_end_offset)) {
 720                                 if (!cmd->unsolicited_data)
 721                                         cmd->next_burst_len -= pdu->length;
 722                                 else
 723                                         cmd->first_burst_len -= pdu->length;
 724
 725                                 cmd->write_data_done -= pdu->length;
 726                                 pdu->status = ISCSI_PDU_NOT_RECEIVED;
 727                         }
 728                 }
 729         } else {
 730                 struct iscsi_seq *seq = NULL;
 731
 732                 seq = iscsit_get_seq_holder(cmd, pdu_offset, pdu_length);
 733                 if (!seq)
 734                         return -1;
 735
 736                 *r2t_offset = seq->orig_offset;
 737                 *r2t_length = seq->xfer_len;
 738
 739                 cmd->write_data_done -= (seq->offset - seq->orig_offset);
 740                 if (cmd->immediate_data)
 741                         cmd->first_burst_len = cmd->write_data_done;
 742
 743                 seq->data_sn = 0;
 744                 seq->offset = seq->orig_offset;
 745                 seq->next_burst_len = 0;
 746                 seq->status = DATAOUT_SEQUENCE_WITHIN_COMMAND_RECOVERY;
 747
 748                 if (conn->sess->sess_ops->DataPDUInOrder)
 749                         return 0;
 750
 751                 for (i = 0; i < seq->pdu_count; i++) {
 752                         pdu = &cmd->pdu_list[i+seq->pdu_start];
 753
 754                         if (pdu->status != ISCSI_PDU_RECEIVED_OK)
 755                                 continue;
 756
 757                         pdu->status = ISCSI_PDU_NOT_RECEIVED;
 758                 }
 759         }
 760
 761         return 0;
 762 }
 763
 764 int iscsit_recover_dataout_sequence(
 765         struct iscsi_cmd *cmd,
 766         u32 pdu_offset,
 767         u32 pdu_length)
 768 {
 769         u32 r2t_length = 0, r2t_offset = 0;
 770
 771         spin_lock_bh(&cmd->istate_lock);
 772         cmd->cmd_flags |= ICF_WITHIN_COMMAND_RECOVERY;
 773         spin_unlock_bh(&cmd->istate_lock);
 774
 775         if (iscsit_recalculate_dataout_values(cmd, pdu_offset, pdu_length,
 776                         &r2t_offset, &r2t_length) < 0)
 777                 return DATAOUT_CANNOT_RECOVER;
 778
 779         iscsit_send_recovery_r2t(cmd, r2t_offset, r2t_length);
 780
 781         return DATAOUT_WITHIN_COMMAND_RECOVERY;
 782 }
 783
 784 static struct iscsi_ooo_cmdsn *iscsit_allocate_ooo_cmdsn(void)
 785 {
 786         struct iscsi_ooo_cmdsn *ooo_cmdsn = NULL;
 787
 788         ooo_cmdsn = kmem_cache_zalloc(lio_ooo_cache, GFP_ATOMIC);
 789         if (!ooo_cmdsn) {
 790                 pr_err("Unable to allocate memory for"
 791                         " struct iscsi_ooo_cmdsn.\n");
 792                 return NULL;
 793         }
 794         INIT_LIST_HEAD(&ooo_cmdsn->ooo_list);
 795
 796         return ooo_cmdsn;
 797 }
 798
 799 /*
 800  *      Called with sess->cmdsn_mutex held.
 801  */
 802 static int iscsit_attach_ooo_cmdsn(
 803         struct iscsi_session *sess,
 804         struct iscsi_ooo_cmdsn *ooo_cmdsn)
 805 {
 806         struct iscsi_ooo_cmdsn *ooo_tail, *ooo_tmp;
 807         /*
 808          * We attach the struct iscsi_ooo_cmdsn entry to the out of order
 809          * list in increasing CmdSN order.
 810          * This allows iscsi_execute_ooo_cmdsns() to detect any
 811          * additional CmdSN holes while performing delayed execution.
 812          */
 813         if (list_empty(&sess->sess_ooo_cmdsn_list))
 814                 list_add_tail(&ooo_cmdsn->ooo_list,
 815                                 &sess->sess_ooo_cmdsn_list);
 816         else {
 817                 ooo_tail = list_entry(sess->sess_ooo_cmdsn_list.prev,
 818                                 typeof(*ooo_tail), ooo_list);
 819                 /*
 820                  * CmdSN is greater than the tail of the list.
 821                  */
 822                 if (ooo_tail->cmdsn < ooo_cmdsn->cmdsn)
 823                         list_add_tail(&ooo_cmdsn->ooo_list,
 824                                         &sess->sess_ooo_cmdsn_list);
 825                 else {
 826                         /*
 827                          * CmdSN is either lower than the head,  or somewhere
 828                          * in the middle.
 829                          */
 830                         list_for_each_entry(ooo_tmp, &sess->sess_ooo_cmdsn_list,
 831                                                 ooo_list) {
 832                                 if (ooo_tmp->cmdsn < ooo_cmdsn->cmdsn)
 833                                         continue;
 834
 835                                 list_add(&ooo_cmdsn->ooo_list,
 836                                         &ooo_tmp->ooo_list);
 837                                 break;
 838                         }
 839                 }
 840         }
 841
 842         return 0;
 843 }
 844
 845 /*
 846  *      Removes an struct iscsi_ooo_cmdsn from a session's list,
 847  *      called with struct iscsi_session->cmdsn_mutex held.
 848  */
 849 void iscsit_remove_ooo_cmdsn(
 850         struct iscsi_session *sess,
 851         struct iscsi_ooo_cmdsn *ooo_cmdsn)
 852 {
 853         list_del(&ooo_cmdsn->ooo_list);
 854         kmem_cache_free(lio_ooo_cache, ooo_cmdsn);
 855 }
 856
 857 void iscsit_clear_ooo_cmdsns_for_conn(struct iscsi_conn *conn)
 858 {
 859         struct iscsi_ooo_cmdsn *ooo_cmdsn;
 860         struct iscsi_session *sess = conn->sess;
 861
 862         mutex_lock(&sess->cmdsn_mutex);
 863         list_for_each_entry(ooo_cmdsn, &sess->sess_ooo_cmdsn_list, ooo_list) {
 864                 if (ooo_cmdsn->cid != conn->cid)
 865                         continue;
 866
 867                 ooo_cmdsn->cmd = NULL;
 868         }
 869         mutex_unlock(&sess->cmdsn_mutex);
 870 }
 871
 872 /*
 873  *      Called with sess->cmdsn_mutex held.
 874  */
 875 int iscsit_execute_ooo_cmdsns(struct iscsi_session *sess)
 876 {
 877         int ooo_count = 0;
 878         struct iscsi_cmd *cmd = NULL;
 879         struct iscsi_ooo_cmdsn *ooo_cmdsn, *ooo_cmdsn_tmp;
 880
 881         list_for_each_entry_safe(ooo_cmdsn, ooo_cmdsn_tmp,
 882                                 &sess->sess_ooo_cmdsn_list, ooo_list) {
 883                 if (ooo_cmdsn->cmdsn != sess->exp_cmd_sn)
 884                         continue;
 885
 886                 if (!ooo_cmdsn->cmd) {
 887                         sess->exp_cmd_sn++;
 888                         iscsit_remove_ooo_cmdsn(sess, ooo_cmdsn);
 889                         continue;
 890                 }
 891
 892                 cmd = ooo_cmdsn->cmd;
 893                 cmd->i_state = cmd->deferred_i_state;
 894                 ooo_count++;
 895                 sess->exp_cmd_sn++;
 896                 pr_debug("Executing out of order CmdSN: 0x%08x,"
 897                         " incremented ExpCmdSN to 0x%08x.\n",
 898                         cmd->cmd_sn, sess->exp_cmd_sn);
 899
 900                 iscsit_remove_ooo_cmdsn(sess, ooo_cmdsn);
 901
 902                 if (iscsit_execute_cmd(cmd, 1) < 0)
 903                         return -1;
 904
 905                 continue;
 906         }
 907
 908         return ooo_count;
 909 }
 910
 911 /*
 912  *      Called either:
 913  *
 914  *      1. With sess->cmdsn_mutex held from iscsi_execute_ooo_cmdsns()
 915  *      or iscsi_check_received_cmdsn().
 916  *      2. With no locks held directly from iscsi_handle_XXX_pdu() functions
 917  *      for immediate commands.
 918  */
 919 int iscsit_execute_cmd(struct iscsi_cmd *cmd, int ooo)
 920 {
 921         struct se_cmd *se_cmd = &cmd->se_cmd;
 922         int lr = 0;
 923
 924         spin_lock_bh(&cmd->istate_lock);
 925         if (ooo)
 926                 cmd->cmd_flags &= ~ICF_OOO_CMDSN;
 927
 928         switch (cmd->iscsi_opcode) {
 929         case ISCSI_OP_SCSI_CMD:
 930                 /*
 931                  * Go ahead and send the CHECK_CONDITION status for
 932                  * any SCSI CDB exceptions that may have occurred, also
 933                  * handle the SCF_SCSI_RESERVATION_CONFLICT case here as well.
 934                  */
 935                 if (se_cmd->se_cmd_flags & SCF_SCSI_CDB_EXCEPTION) {
 936                         if (se_cmd->scsi_sense_reason == TCM_RESERVATION_CONFLICT) {
 937                                 cmd->i_state = ISTATE_SEND_STATUS;
 938                                 spin_unlock_bh(&cmd->istate_lock);
 939                                 iscsit_add_cmd_to_response_queue(cmd, cmd->conn,
 940                                                 cmd->i_state);
 941                                 return 0;
 942                         }
 943                         spin_unlock_bh(&cmd->istate_lock);
 944                         /*
 945                          * Determine if delayed TASK_ABORTED status for WRITEs
 946                          * should be sent now if no unsolicited data out
 947                          * payloads are expected, or if the delayed status
 948                          * should be sent after unsolicited data out with
 949                          * ISCSI_FLAG_CMD_FINAL set in iscsi_handle_data_out()
 950                          */
 951                         if (transport_check_aborted_status(se_cmd,
 952                                         (cmd->unsolicited_data == 0)) != 0)
 953                                 return 0;
 954                         /*
 955                          * Otherwise send CHECK_CONDITION and sense for
 956                          * exception
 957                          */
 958                         return transport_send_check_condition_and_sense(se_cmd,
 959                                         se_cmd->scsi_sense_reason, 0);
 960                 }
 961                 /*
 962                  * Special case for delayed CmdSN with Immediate
 963                  * Data and/or Unsolicited Data Out attached.
 964                  */
 965                 if (cmd->immediate_data) {
 966                         if (cmd->cmd_flags & ICF_GOT_LAST_DATAOUT) {
 967                                 spin_unlock_bh(&cmd->istate_lock);
 968                                 target_execute_cmd(&cmd->se_cmd);
 969                                 return 0;
 970                         }
 971                         spin_unlock_bh(&cmd->istate_lock);
 972
 973                         if (!(cmd->cmd_flags &
 974                                         ICF_NON_IMMEDIATE_UNSOLICITED_DATA)) {
 975                                 /*
 976                                  * Send the delayed TASK_ABORTED status for
 977                                  * WRITEs if no more unsolicitied data is
 978                                  * expected.
 979                                  */
 980                                 if (transport_check_aborted_status(se_cmd, 1)
 981                                                 != 0)
 982                                         return 0;
 983
 984                                 iscsit_set_dataout_sequence_values(cmd);
 985                                 iscsit_build_r2ts_for_cmd(cmd, cmd->conn, false);
 986                         }
 987                         return 0;
 988                 }
 989                 /*
 990                  * The default handler.
 991                  */
 992                 spin_unlock_bh(&cmd->istate_lock);
 993
 994                 if ((cmd->data_direction == DMA_TO_DEVICE) &&
 995                     !(cmd->cmd_flags & ICF_NON_IMMEDIATE_UNSOLICITED_DATA)) {
 996                         /*
 997                          * Send the delayed TASK_ABORTED status for WRITEs if
 998                          * no more nsolicitied data is expected.
 999                          */
1000                         if (transport_check_aborted_status(se_cmd, 1) != 0)
1001                                 return 0;
1002
1003                         iscsit_set_dataout_sequence_values(cmd);
1004                         spin_lock_bh(&cmd->dataout_timeout_lock);
1005                         iscsit_start_dataout_timer(cmd, cmd->conn);
1006                         spin_unlock_bh(&cmd->dataout_timeout_lock);
1007                 }
1008                 return transport_handle_cdb_direct(&cmd->se_cmd);
1009
1010         case ISCSI_OP_NOOP_OUT:
1011         case ISCSI_OP_TEXT:
1012                 spin_unlock_bh(&cmd->istate_lock);
1013                 iscsit_add_cmd_to_response_queue(cmd, cmd->conn, cmd->i_state);
1014                 break;
1015         case ISCSI_OP_SCSI_TMFUNC:
1016                 if (se_cmd->se_cmd_flags & SCF_SCSI_CDB_EXCEPTION) {
1017                         spin_unlock_bh(&cmd->istate_lock);
1018                         iscsit_add_cmd_to_response_queue(cmd, cmd->conn,
1019                                         cmd->i_state);
1020                         return 0;
1021                 }
1022                 spin_unlock_bh(&cmd->istate_lock);
1023
1024                 return transport_generic_handle_tmr(&cmd->se_cmd);
1025         case ISCSI_OP_LOGOUT:
1026                 spin_unlock_bh(&cmd->istate_lock);
1027                 switch (cmd->logout_reason) {
1028                 case ISCSI_LOGOUT_REASON_CLOSE_SESSION:
1029                         lr = iscsit_logout_closesession(cmd, cmd->conn);
1030                         break;
1031                 case ISCSI_LOGOUT_REASON_CLOSE_CONNECTION:
1032                         lr = iscsit_logout_closeconnection(cmd, cmd->conn);
1033                         break;
1034                 case ISCSI_LOGOUT_REASON_RECOVERY:
1035                         lr = iscsit_logout_removeconnforrecovery(cmd, cmd->conn);
1036                         break;
1037                 default:
1038                         pr_err("Unknown iSCSI Logout Request Code:"
1039                                 " 0x%02x\n", cmd->logout_reason);
1040                         return -1;
1041                 }
1042
1043                 return lr;
1044         default:
1045                 spin_unlock_bh(&cmd->istate_lock);
1046                 pr_err("Cannot perform out of order execution for"
1047                 " unknown iSCSI Opcode: 0x%02x\n", cmd->iscsi_opcode);
1048                 return -1;
1049         }
1050
1051         return 0;
1052 }
1053
1054 void iscsit_free_all_ooo_cmdsns(struct iscsi_session *sess)
1055 {
1056         struct iscsi_ooo_cmdsn *ooo_cmdsn, *ooo_cmdsn_tmp;
1057
1058         mutex_lock(&sess->cmdsn_mutex);
1059         list_for_each_entry_safe(ooo_cmdsn, ooo_cmdsn_tmp,
1060                         &sess->sess_ooo_cmdsn_list, ooo_list) {
1061
1062                 list_del(&ooo_cmdsn->ooo_list);
1063                 kmem_cache_free(lio_ooo_cache, ooo_cmdsn);
1064         }
1065         mutex_unlock(&sess->cmdsn_mutex);
1066 }
1067
1068 int iscsit_handle_ooo_cmdsn(
1069         struct iscsi_session *sess,
1070         struct iscsi_cmd *cmd,
1071         u32 cmdsn)
1072 {
1073         int batch = 0;
1074         struct iscsi_ooo_cmdsn *ooo_cmdsn = NULL, *ooo_tail = NULL;
1075
1076         cmd->deferred_i_state           = cmd->i_state;
1077         cmd->i_state                    = ISTATE_DEFERRED_CMD;
1078         cmd->cmd_flags                  |= ICF_OOO_CMDSN;
1079
1080         if (list_empty(&sess->sess_ooo_cmdsn_list))
1081                 batch = 1;
1082         else {
1083                 ooo_tail = list_entry(sess->sess_ooo_cmdsn_list.prev,
1084                                 typeof(*ooo_tail), ooo_list);
1085                 if (ooo_tail->cmdsn != (cmdsn - 1))
1086                         batch = 1;
1087         }
1088
1089         ooo_cmdsn = iscsit_allocate_ooo_cmdsn();
1090         if (!ooo_cmdsn)
1091                 return CMDSN_ERROR_CANNOT_RECOVER;
1092
1093         ooo_cmdsn->cmd                  = cmd;
1094         ooo_cmdsn->batch_count          = (batch) ?
1095                                           (cmdsn - sess->exp_cmd_sn) : 1;
1096         ooo_cmdsn->cid                  = cmd->conn->cid;
1097         ooo_cmdsn->exp_cmdsn            = sess->exp_cmd_sn;
1098         ooo_cmdsn->cmdsn                = cmdsn;
1099
1100         if (iscsit_attach_ooo_cmdsn(sess, ooo_cmdsn) < 0) {
1101                 kmem_cache_free(lio_ooo_cache, ooo_cmdsn);
1102                 return CMDSN_ERROR_CANNOT_RECOVER;
1103         }
1104
1105         return CMDSN_HIGHER_THAN_EXP;
1106 }
1107
1108 static int iscsit_set_dataout_timeout_values(
1109         struct iscsi_cmd *cmd,
1110         u32 *offset,
1111         u32 *length)
1112 {
1113         struct iscsi_conn *conn = cmd->conn;
1114         struct iscsi_r2t *r2t;
1115
1116         if (cmd->unsolicited_data) {
1117                 *offset = 0;
1118                 *length = (conn->sess->sess_ops->FirstBurstLength >
1119                            cmd->se_cmd.data_length) ?
1120                            cmd->se_cmd.data_length :
1121                            conn->sess->sess_ops->FirstBurstLength;
1122                 return 0;
1123         }
1124
1125         spin_lock_bh(&cmd->r2t_lock);
1126         if (list_empty(&cmd->cmd_r2t_list)) {
1127                 pr_err("cmd->cmd_r2t_list is empty!\n");
1128                 spin_unlock_bh(&cmd->r2t_lock);
1129                 return -1;
1130         }
1131
1132         list_for_each_entry(r2t, &cmd->cmd_r2t_list, r2t_list) {
1133                 if (r2t->sent_r2t && !r2t->recovery_r2t && !r2t->seq_complete) {
1134                         *offset = r2t->offset;
1135                         *length = r2t->xfer_len;
1136                         spin_unlock_bh(&cmd->r2t_lock);
1137                         return 0;
1138                 }
1139         }
1140         spin_unlock_bh(&cmd->r2t_lock);
1141
1142         pr_err("Unable to locate any incomplete DataOUT"
1143                 " sequences for ITT: 0x%08x.\n", cmd->init_task_tag);
1144
1145         return -1;
1146 }
1147
1148 /*
1149  *      NOTE: Called from interrupt (timer) context.
1150  */
1151 static void iscsit_handle_dataout_timeout(unsigned long data)
1152 {
1153         u32 pdu_length = 0, pdu_offset = 0;
1154         u32 r2t_length = 0, r2t_offset = 0;
1155         struct iscsi_cmd *cmd = (struct iscsi_cmd *) data;
1156         struct iscsi_conn *conn = cmd->conn;
1157         struct iscsi_session *sess = NULL;
1158         struct iscsi_node_attrib *na;
1159
1160         iscsit_inc_conn_usage_count(conn);
1161
1162         spin_lock_bh(&cmd->dataout_timeout_lock);
1163         if (cmd->dataout_timer_flags & ISCSI_TF_STOP) {
1164                 spin_unlock_bh(&cmd->dataout_timeout_lock);
1165                 iscsit_dec_conn_usage_count(conn);
1166                 return;
1167         }
1168         cmd->dataout_timer_flags &= ~ISCSI_TF_RUNNING;
1169         sess = conn->sess;
1170         na = iscsit_tpg_get_node_attrib(sess);
1171
1172         if (!sess->sess_ops->ErrorRecoveryLevel) {
1173                 pr_debug("Unable to recover from DataOut timeout while"
1174                         " in ERL=0.\n");
1175                 goto failure;
1176         }
1177
1178         if (++cmd->dataout_timeout_retries == na->dataout_timeout_retries) {
1179                 pr_debug("Command ITT: 0x%08x exceeded max retries"
1180                         " for DataOUT timeout %u, closing iSCSI connection.\n",
1181                         cmd->init_task_tag, na->dataout_timeout_retries);
1182                 goto failure;
1183         }
1184
1185         cmd->cmd_flags |= ICF_WITHIN_COMMAND_RECOVERY;
1186
1187         if (conn->sess->sess_ops->DataSequenceInOrder) {
1188                 if (conn->sess->sess_ops->DataPDUInOrder) {
1189                         pdu_offset = cmd->write_data_done;
1190                         if ((pdu_offset + (conn->sess->sess_ops->MaxBurstLength -
1191                              cmd->next_burst_len)) > cmd->se_cmd.data_length)
1192                                 pdu_length = (cmd->se_cmd.data_length -
1193                                         cmd->write_data_done);
1194                         else
1195                                 pdu_length = (conn->sess->sess_ops->MaxBurstLength -
1196                                                 cmd->next_burst_len);
1197                 } else {
1198                         pdu_offset = cmd->seq_start_offset;
1199                         pdu_length = (cmd->seq_end_offset -
1200                                 cmd->seq_start_offset);
1201                 }
1202         } else {
1203                 if (iscsit_set_dataout_timeout_values(cmd, &pdu_offset,
1204                                 &pdu_length) < 0)
1205                         goto failure;
1206         }
1207
1208         if (iscsit_recalculate_dataout_values(cmd, pdu_offset, pdu_length,
1209                         &r2t_offset, &r2t_length) < 0)
1210                 goto failure;
1211
1212         pr_debug("Command ITT: 0x%08x timed out waiting for"
1213                 " completion of %sDataOUT Sequence Offset: %u, Length: %u\n",
1214                 cmd->init_task_tag, (cmd->unsolicited_data) ? "Unsolicited " :
1215                 "", r2t_offset, r2t_length);
1216
1217         if (iscsit_send_recovery_r2t(cmd, r2t_offset, r2t_length) < 0)
1218                 goto failure;
1219
1220         iscsit_start_dataout_timer(cmd, conn);
1221         spin_unlock_bh(&cmd->dataout_timeout_lock);
1222         iscsit_dec_conn_usage_count(conn);
1223
1224         return;
1225
1226 failure:
1227         spin_unlock_bh(&cmd->dataout_timeout_lock);
1228         iscsit_cause_connection_reinstatement(conn, 0);
1229         iscsit_dec_conn_usage_count(conn);
1230 }
1231
1232 void iscsit_mod_dataout_timer(struct iscsi_cmd *cmd)
1233 {
1234         struct iscsi_conn *conn = cmd->conn;
1235         struct iscsi_session *sess = conn->sess;
1236         struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
1237
1238         spin_lock_bh(&cmd->dataout_timeout_lock);
1239         if (!(cmd->dataout_timer_flags & ISCSI_TF_RUNNING)) {
1240                 spin_unlock_bh(&cmd->dataout_timeout_lock);
1241                 return;
1242         }
1243
1244         mod_timer(&cmd->dataout_timer,
1245                 (get_jiffies_64() + na->dataout_timeout * HZ));
1246         pr_debug("Updated DataOUT timer for ITT: 0x%08x",
1247                         cmd->init_task_tag);
1248         spin_unlock_bh(&cmd->dataout_timeout_lock);
1249 }
1250
1251 /*
1252  *      Called with cmd->dataout_timeout_lock held.
1253  */
1254 void iscsit_start_dataout_timer(
1255         struct iscsi_cmd *cmd,
1256         struct iscsi_conn *conn)
1257 {
1258         struct iscsi_session *sess = conn->sess;
1259         struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
1260
1261         if (cmd->dataout_timer_flags & ISCSI_TF_RUNNING)
1262                 return;
1263
1264         pr_debug("Starting DataOUT timer for ITT: 0x%08x on"
1265                 " CID: %hu.\n", cmd->init_task_tag, conn->cid);
1266
1267         init_timer(&cmd->dataout_timer);
1268         cmd->dataout_timer.expires = (get_jiffies_64() + na->dataout_timeout * HZ);
1269         cmd->dataout_timer.data = (unsigned long)cmd;
1270         cmd->dataout_timer.function = iscsit_handle_dataout_timeout;
1271         cmd->dataout_timer_flags &= ~ISCSI_TF_STOP;
1272         cmd->dataout_timer_flags |= ISCSI_TF_RUNNING;
1273         add_timer(&cmd->dataout_timer);
1274 }
1275
1276 void iscsit_stop_dataout_timer(struct iscsi_cmd *cmd)
1277 {
1278         spin_lock_bh(&cmd->dataout_timeout_lock);
1279         if (!(cmd->dataout_timer_flags & ISCSI_TF_RUNNING)) {
1280                 spin_unlock_bh(&cmd->dataout_timeout_lock);
1281                 return;
1282         }
1283         cmd->dataout_timer_flags |= ISCSI_TF_STOP;
1284         spin_unlock_bh(&cmd->dataout_timeout_lock);
1285
1286         del_timer_sync(&cmd->dataout_timer);
1287
1288         spin_lock_bh(&cmd->dataout_timeout_lock);
1289         cmd->dataout_timer_flags &= ~ISCSI_TF_RUNNING;
1290         pr_debug("Stopped DataOUT Timer for ITT: 0x%08x\n",
1291                         cmd->init_task_tag);
1292         spin_unlock_bh(&cmd->dataout_timeout_lock);
1293 }