drivers/target/iscsi/iscsi_target_erl1.c

   1 /*******************************************************************************
   2  * This file contains error recovery level one used by the iSCSI Target driver.
   3  *
   4  * (c) Copyright 2007-2013 Datera, Inc.
   5  *
   6  * Author: Nicholas A. Bellinger <nab@linux-iscsi.org>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  ******************************************************************************/
  18
  19 #include <linux/list.h>
  20 #include <linux/slab.h>
  21 #include <scsi/iscsi_proto.h>
  22 #include <target/target_core_base.h>
  23 #include <target/target_core_fabric.h>
  24 #include <target/iscsi/iscsi_transport.h>
  25
  26 #include <target/iscsi/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        32768U
  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         if (conn->sess->sess_ops->RDMAExtensions)
  57                 return 0;
  58
  59         length = min(buf_len, OFFLOAD_BUF_SIZE);
  60
  61         buf = kzalloc(length, GFP_ATOMIC);
  62         if (!buf) {
  63                 pr_err("Unable to allocate %u bytes for offload"
  64                                 " buffer.\n", length);
  65                 return -1;
  66         }
  67         memset(&iov, 0, sizeof(struct kvec));
  68
  69         while (offset < buf_len) {
  70                 size = min(buf_len - offset, length);
  71
  72                 iov.iov_len = size;
  73                 iov.iov_base = buf;
  74
  75                 rx_got = rx_data(conn, &iov, 1, size);
  76                 if (rx_got != size) {
  77                         ret = DATAOUT_CANNOT_RECOVER;
  78                         goto out;
  79                 }
  80
  81                 offset += size;
  82         }
  83
  84         if (!dump_padding_digest)
  85                 goto out;
  86
  87         padding = ((-buf_len) & 3);
  88         if (padding != 0) {
  89                 iov.iov_len = padding;
  90                 iov.iov_base = pad_bytes;
  91
  92                 rx_got = rx_data(conn, &iov, 1, padding);
  93                 if (rx_got != padding) {
  94                         ret = DATAOUT_CANNOT_RECOVER;
  95                         goto out;
  96                 }
  97         }
  98
  99         if (conn->conn_ops->DataDigest) {
 100                 u32 data_crc;
 101
 102                 iov.iov_len = ISCSI_CRC_LEN;
 103                 iov.iov_base = &data_crc;
 104
 105                 rx_got = rx_data(conn, &iov, 1, ISCSI_CRC_LEN);
 106                 if (rx_got != ISCSI_CRC_LEN) {
 107                         ret = DATAOUT_CANNOT_RECOVER;
 108                         goto out;
 109                 }
 110         }
 111
 112 out:
 113         kfree(buf);
 114         return ret;
 115 }
 116
 117 /*
 118  *      Used for retransmitting R2Ts from a R2T SNACK request.
 119  */
 120 static int iscsit_send_recovery_r2t_for_snack(
 121         struct iscsi_cmd *cmd,
 122         struct iscsi_r2t *r2t)
 123 {
 124         /*
 125          * If the struct iscsi_r2t has not been sent yet, we can safely
 126          * ignore retransmission
 127          * of the R2TSN in question.
 128          */
 129         spin_lock_bh(&cmd->r2t_lock);
 130         if (!r2t->sent_r2t) {
 131                 spin_unlock_bh(&cmd->r2t_lock);
 132                 return 0;
 133         }
 134         r2t->sent_r2t = 0;
 135         spin_unlock_bh(&cmd->r2t_lock);
 136
 137         iscsit_add_cmd_to_immediate_queue(cmd, cmd->conn, ISTATE_SEND_R2T);
 138
 139         return 0;
 140 }
 141
 142 static int iscsit_handle_r2t_snack(
 143         struct iscsi_cmd *cmd,
 144         unsigned char *buf,
 145         u32 begrun,
 146         u32 runlength)
 147 {
 148         u32 last_r2tsn;
 149         struct iscsi_r2t *r2t;
 150
 151         /*
 152          * Make sure the initiator is not requesting retransmission
 153          * of R2TSNs already acknowledged by a TMR TASK_REASSIGN.
 154          */
 155         if ((cmd->cmd_flags & ICF_GOT_DATACK_SNACK) &&
 156             (begrun <= cmd->acked_data_sn)) {
 157                 pr_err("ITT: 0x%08x, R2T SNACK requesting"
 158                         " retransmission of R2TSN: 0x%08x to 0x%08x but already"
 159                         " acked to  R2TSN: 0x%08x by TMR TASK_REASSIGN,"
 160                         " protocol error.\n", cmd->init_task_tag, begrun,
 161                         (begrun + runlength), cmd->acked_data_sn);
 162
 163                 return iscsit_reject_cmd(cmd, ISCSI_REASON_PROTOCOL_ERROR, buf);
 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_reject_cmd(cmd,
 173                                         ISCSI_REASON_BOOKMARK_INVALID, buf);
 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_reject_cmd(cmd, ISCSI_REASON_PROTOCOL_ERROR, buf);
 433         }
 434
 435         /*
 436          * Make sure BegRun and RunLength in the Data SNACK are sane.
 437          * Note: (cmd->data_sn - 1) will carry the maximum DataSN sent.
 438          */
 439         if ((begrun + runlength) > (cmd->data_sn - 1)) {
 440                 pr_err("Initiator requesting BegRun: 0x%08x, RunLength"
 441                         ": 0x%08x greater than maximum DataSN: 0x%08x.\n",
 442                                 begrun, runlength, (cmd->data_sn - 1));
 443                 return iscsit_reject_cmd(cmd, ISCSI_REASON_BOOKMARK_INVALID,
 444                                          buf);
 445         }
 446
 447         dr = iscsit_allocate_datain_req();
 448         if (!dr)
 449                 return iscsit_reject_cmd(cmd, ISCSI_REASON_BOOKMARK_NO_RESOURCES,
 450                                          buf);
 451
 452         dr->data_sn = dr->begrun = begrun;
 453         dr->runlength = runlength;
 454         dr->generate_recovery_values = 1;
 455         dr->recovery = DATAIN_WITHIN_COMMAND_RECOVERY;
 456
 457         iscsit_attach_datain_req(cmd, dr);
 458
 459         cmd->i_state = ISTATE_SEND_DATAIN;
 460         iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
 461
 462         return 0;
 463 }
 464
 465 int iscsit_handle_recovery_datain_or_r2t(
 466         struct iscsi_conn *conn,
 467         unsigned char *buf,
 468         itt_t init_task_tag,
 469         u32 targ_xfer_tag,
 470         u32 begrun,
 471         u32 runlength)
 472 {
 473         struct iscsi_cmd *cmd;
 474
 475         cmd = iscsit_find_cmd_from_itt(conn, init_task_tag);
 476         if (!cmd)
 477                 return 0;
 478
 479         /*
 480          * FIXME: This will not work for bidi commands.
 481          */
 482         switch (cmd->data_direction) {
 483         case DMA_TO_DEVICE:
 484                 return iscsit_handle_r2t_snack(cmd, buf, begrun, runlength);
 485         case DMA_FROM_DEVICE:
 486                 return iscsit_handle_recovery_datain(cmd, buf, begrun,
 487                                 runlength);
 488         default:
 489                 pr_err("Unknown cmd->data_direction: 0x%02x\n",
 490                                 cmd->data_direction);
 491                 return -1;
 492         }
 493
 494         return 0;
 495 }
 496
 497 /* #warning FIXME: Status SNACK needs to be dependent on OPCODE!!! */
 498 int iscsit_handle_status_snack(
 499         struct iscsi_conn *conn,
 500         itt_t init_task_tag,
 501         u32 targ_xfer_tag,
 502         u32 begrun,
 503         u32 runlength)
 504 {
 505         struct iscsi_cmd *cmd = NULL;
 506         u32 last_statsn;
 507         int found_cmd;
 508
 509         if (!begrun) {
 510                 begrun = conn->exp_statsn;
 511         } else if (conn->exp_statsn > begrun) {
 512                 pr_err("Got Status SNACK Begrun: 0x%08x, RunLength:"
 513                         " 0x%08x but already got ExpStatSN: 0x%08x on CID:"
 514                         " %hu.\n", begrun, runlength, conn->exp_statsn,
 515                         conn->cid);
 516                 return 0;
 517         }
 518
 519         last_statsn = (!runlength) ? conn->stat_sn : (begrun + runlength);
 520
 521         while (begrun < last_statsn) {
 522                 found_cmd = 0;
 523
 524                 spin_lock_bh(&conn->cmd_lock);
 525                 list_for_each_entry(cmd, &conn->conn_cmd_list, i_conn_node) {
 526                         if (cmd->stat_sn == begrun) {
 527                                 found_cmd = 1;
 528                                 break;
 529                         }
 530                 }
 531                 spin_unlock_bh(&conn->cmd_lock);
 532
 533                 if (!found_cmd) {
 534                         pr_err("Unable to find StatSN: 0x%08x for"
 535                                 " a Status SNACK, assuming this was a"
 536                                 " protactic SNACK for an untransmitted"
 537                                 " StatSN, ignoring.\n", begrun);
 538                         begrun++;
 539                         continue;
 540                 }
 541
 542                 spin_lock_bh(&cmd->istate_lock);
 543                 if (cmd->i_state == ISTATE_SEND_DATAIN) {
 544                         spin_unlock_bh(&cmd->istate_lock);
 545                         pr_err("Ignoring Status SNACK for BegRun:"
 546                                 " 0x%08x, RunLength: 0x%08x, assuming this was"
 547                                 " a protactic SNACK for an untransmitted"
 548                                 " StatSN\n", begrun, runlength);
 549                         begrun++;
 550                         continue;
 551                 }
 552                 spin_unlock_bh(&cmd->istate_lock);
 553
 554                 cmd->i_state = ISTATE_SEND_STATUS_RECOVERY;
 555                 iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
 556                 begrun++;
 557         }
 558
 559         return 0;
 560 }
 561
 562 int iscsit_handle_data_ack(
 563         struct iscsi_conn *conn,
 564         u32 targ_xfer_tag,
 565         u32 begrun,
 566         u32 runlength)
 567 {
 568         struct iscsi_cmd *cmd = NULL;
 569
 570         cmd = iscsit_find_cmd_from_ttt(conn, targ_xfer_tag);
 571         if (!cmd) {
 572                 pr_err("Data ACK SNACK for TTT: 0x%08x is"
 573                         " invalid.\n", targ_xfer_tag);
 574                 return -1;
 575         }
 576
 577         if (begrun <= cmd->acked_data_sn) {
 578                 pr_err("ITT: 0x%08x Data ACK SNACK BegRUN: 0x%08x is"
 579                         " less than the already acked DataSN: 0x%08x.\n",
 580                         cmd->init_task_tag, begrun, cmd->acked_data_sn);
 581                 return -1;
 582         }
 583
 584         /*
 585          * For Data ACK SNACK, BegRun is the next expected DataSN.
 586          * (see iSCSI v19: 10.16.6)
 587          */
 588         cmd->cmd_flags |= ICF_GOT_DATACK_SNACK;
 589         cmd->acked_data_sn = (begrun - 1);
 590
 591         pr_debug("Received Data ACK SNACK for ITT: 0x%08x,"
 592                 " updated acked DataSN to 0x%08x.\n",
 593                         cmd->init_task_tag, cmd->acked_data_sn);
 594
 595         return 0;
 596 }
 597
 598 static int iscsit_send_recovery_r2t(
 599         struct iscsi_cmd *cmd,
 600         u32 offset,
 601         u32 xfer_len)
 602 {
 603         int ret;
 604
 605         spin_lock_bh(&cmd->r2t_lock);
 606         ret = iscsit_add_r2t_to_list(cmd, offset, xfer_len, 1, 0);
 607         spin_unlock_bh(&cmd->r2t_lock);
 608
 609         return ret;
 610 }
 611
 612 int iscsit_dataout_datapduinorder_no_fbit(
 613         struct iscsi_cmd *cmd,
 614         struct iscsi_pdu *pdu)
 615 {
 616         int i, send_recovery_r2t = 0, recovery = 0;
 617         u32 length = 0, offset = 0, pdu_count = 0, xfer_len = 0;
 618         struct iscsi_conn *conn = cmd->conn;
 619         struct iscsi_pdu *first_pdu = NULL;
 620
 621         /*
 622          * Get an struct iscsi_pdu pointer to the first PDU, and total PDU count
 623          * of the DataOUT sequence.
 624          */
 625         if (conn->sess->sess_ops->DataSequenceInOrder) {
 626                 for (i = 0; i < cmd->pdu_count; i++) {
 627                         if (cmd->pdu_list[i].seq_no == pdu->seq_no) {
 628                                 if (!first_pdu)
 629                                         first_pdu = &cmd->pdu_list[i];
 630                                 xfer_len += cmd->pdu_list[i].length;
 631                                 pdu_count++;
 632                         } else if (pdu_count)
 633                                 break;
 634                 }
 635         } else {
 636                 struct iscsi_seq *seq = cmd->seq_ptr;
 637
 638                 first_pdu = &cmd->pdu_list[seq->pdu_start];
 639                 pdu_count = seq->pdu_count;
 640         }
 641
 642         if (!first_pdu || !pdu_count)
 643                 return DATAOUT_CANNOT_RECOVER;
 644
 645         /*
 646          * Loop through the ending DataOUT Sequence checking each struct iscsi_pdu.
 647          * The following ugly logic does batching of not received PDUs.
 648          */
 649         for (i = 0; i < pdu_count; i++) {
 650                 if (first_pdu[i].status == ISCSI_PDU_RECEIVED_OK) {
 651                         if (!send_recovery_r2t)
 652                                 continue;
 653
 654                         if (iscsit_send_recovery_r2t(cmd, offset, length) < 0)
 655                                 return DATAOUT_CANNOT_RECOVER;
 656
 657                         send_recovery_r2t = length = offset = 0;
 658                         continue;
 659                 }
 660                 /*
 661                  * Set recovery = 1 for any missing, CRC failed, or timed
 662                  * out PDUs to let the DataOUT logic know that this sequence
 663                  * has not been completed yet.
 664                  *
 665                  * Also, only send a Recovery R2T for ISCSI_PDU_NOT_RECEIVED.
 666                  * We assume if the PDU either failed CRC or timed out
 667                  * that a Recovery R2T has already been sent.
 668                  */
 669                 recovery = 1;
 670
 671                 if (first_pdu[i].status != ISCSI_PDU_NOT_RECEIVED)
 672                         continue;
 673
 674                 if (!offset)
 675                         offset = first_pdu[i].offset;
 676                 length += first_pdu[i].length;
 677
 678                 send_recovery_r2t = 1;
 679         }
 680
 681         if (send_recovery_r2t)
 682                 if (iscsit_send_recovery_r2t(cmd, offset, length) < 0)
 683                         return DATAOUT_CANNOT_RECOVER;
 684
 685         return (!recovery) ? DATAOUT_NORMAL : DATAOUT_WITHIN_COMMAND_RECOVERY;
 686 }
 687
 688 static int iscsit_recalculate_dataout_values(
 689         struct iscsi_cmd *cmd,
 690         u32 pdu_offset,
 691         u32 pdu_length,
 692         u32 *r2t_offset,
 693         u32 *r2t_length)
 694 {
 695         int i;
 696         struct iscsi_conn *conn = cmd->conn;
 697         struct iscsi_pdu *pdu = NULL;
 698
 699         if (conn->sess->sess_ops->DataSequenceInOrder) {
 700                 cmd->data_sn = 0;
 701
 702                 if (conn->sess->sess_ops->DataPDUInOrder) {
 703                         *r2t_offset = cmd->write_data_done;
 704                         *r2t_length = (cmd->seq_end_offset -
 705                                         cmd->write_data_done);
 706                         return 0;
 707                 }
 708
 709                 *r2t_offset = cmd->seq_start_offset;
 710                 *r2t_length = (cmd->seq_end_offset - cmd->seq_start_offset);
 711
 712                 for (i = 0; i < cmd->pdu_count; i++) {
 713                         pdu = &cmd->pdu_list[i];
 714
 715                         if (pdu->status != ISCSI_PDU_RECEIVED_OK)
 716                                 continue;
 717
 718                         if ((pdu->offset >= cmd->seq_start_offset) &&
 719                            ((pdu->offset + pdu->length) <=
 720                              cmd->seq_end_offset)) {
 721                                 if (!cmd->unsolicited_data)
 722                                         cmd->next_burst_len -= pdu->length;
 723                                 else
 724                                         cmd->first_burst_len -= pdu->length;
 725
 726                                 cmd->write_data_done -= pdu->length;
 727                                 pdu->status = ISCSI_PDU_NOT_RECEIVED;
 728                         }
 729                 }
 730         } else {
 731                 struct iscsi_seq *seq = NULL;
 732
 733                 seq = iscsit_get_seq_holder(cmd, pdu_offset, pdu_length);
 734                 if (!seq)
 735                         return -1;
 736
 737                 *r2t_offset = seq->orig_offset;
 738                 *r2t_length = seq->xfer_len;
 739
 740                 cmd->write_data_done -= (seq->offset - seq->orig_offset);
 741                 if (cmd->immediate_data)
 742                         cmd->first_burst_len = cmd->write_data_done;
 743
 744                 seq->data_sn = 0;
 745                 seq->offset = seq->orig_offset;
 746                 seq->next_burst_len = 0;
 747                 seq->status = DATAOUT_SEQUENCE_WITHIN_COMMAND_RECOVERY;
 748
 749                 if (conn->sess->sess_ops->DataPDUInOrder)
 750                         return 0;
 751
 752                 for (i = 0; i < seq->pdu_count; i++) {
 753                         pdu = &cmd->pdu_list[i+seq->pdu_start];
 754
 755                         if (pdu->status != ISCSI_PDU_RECEIVED_OK)
 756                                 continue;
 757
 758                         pdu->status = ISCSI_PDU_NOT_RECEIVED;
 759                 }
 760         }
 761
 762         return 0;
 763 }
 764
 765 int iscsit_recover_dataout_sequence(
 766         struct iscsi_cmd *cmd,
 767         u32 pdu_offset,
 768         u32 pdu_length)
 769 {
 770         u32 r2t_length = 0, r2t_offset = 0;
 771
 772         spin_lock_bh(&cmd->istate_lock);
 773         cmd->cmd_flags |= ICF_WITHIN_COMMAND_RECOVERY;
 774         spin_unlock_bh(&cmd->istate_lock);
 775
 776         if (iscsit_recalculate_dataout_values(cmd, pdu_offset, pdu_length,
 777                         &r2t_offset, &r2t_length) < 0)
 778                 return DATAOUT_CANNOT_RECOVER;
 779
 780         iscsit_send_recovery_r2t(cmd, r2t_offset, r2t_length);
 781
 782         return DATAOUT_WITHIN_COMMAND_RECOVERY;
 783 }
 784
 785 static struct iscsi_ooo_cmdsn *iscsit_allocate_ooo_cmdsn(void)
 786 {
 787         struct iscsi_ooo_cmdsn *ooo_cmdsn = NULL;
 788
 789         ooo_cmdsn = kmem_cache_zalloc(lio_ooo_cache, GFP_ATOMIC);
 790         if (!ooo_cmdsn) {
 791                 pr_err("Unable to allocate memory for"
 792                         " struct iscsi_ooo_cmdsn.\n");
 793                 return NULL;
 794         }
 795         INIT_LIST_HEAD(&ooo_cmdsn->ooo_list);
 796
 797         return ooo_cmdsn;
 798 }
 799
 800 /*
 801  *      Called with sess->cmdsn_mutex held.
 802  */
 803 static int iscsit_attach_ooo_cmdsn(
 804         struct iscsi_session *sess,
 805         struct iscsi_ooo_cmdsn *ooo_cmdsn)
 806 {
 807         struct iscsi_ooo_cmdsn *ooo_tail, *ooo_tmp;
 808         /*
 809          * We attach the struct iscsi_ooo_cmdsn entry to the out of order
 810          * list in increasing CmdSN order.
 811          * This allows iscsi_execute_ooo_cmdsns() to detect any
 812          * additional CmdSN holes while performing delayed execution.
 813          */
 814         if (list_empty(&sess->sess_ooo_cmdsn_list))
 815                 list_add_tail(&ooo_cmdsn->ooo_list,
 816                                 &sess->sess_ooo_cmdsn_list);
 817         else {
 818                 ooo_tail = list_entry(sess->sess_ooo_cmdsn_list.prev,
 819                                 typeof(*ooo_tail), ooo_list);
 820                 /*
 821                  * CmdSN is greater than the tail of the list.
 822                  */
 823                 if (iscsi_sna_lt(ooo_tail->cmdsn, ooo_cmdsn->cmdsn))
 824                         list_add_tail(&ooo_cmdsn->ooo_list,
 825                                         &sess->sess_ooo_cmdsn_list);
 826                 else {
 827                         /*
 828                          * CmdSN is either lower than the head,  or somewhere
 829                          * in the middle.
 830                          */
 831                         list_for_each_entry(ooo_tmp, &sess->sess_ooo_cmdsn_list,
 832                                                 ooo_list) {
 833                                 if (iscsi_sna_lt(ooo_tmp->cmdsn, ooo_cmdsn->cmdsn))
 834                                         continue;
 835
 836                                 /* Insert before this entry */
 837                                 list_add(&ooo_cmdsn->ooo_list,
 838                                         ooo_tmp->ooo_list.prev);
 839                                 break;
 840                         }
 841                 }
 842         }
 843
 844         return 0;
 845 }
 846
 847 /*
 848  *      Removes an struct iscsi_ooo_cmdsn from a session's list,
 849  *      called with struct iscsi_session->cmdsn_mutex held.
 850  */
 851 void iscsit_remove_ooo_cmdsn(
 852         struct iscsi_session *sess,
 853         struct iscsi_ooo_cmdsn *ooo_cmdsn)
 854 {
 855         list_del(&ooo_cmdsn->ooo_list);
 856         kmem_cache_free(lio_ooo_cache, ooo_cmdsn);
 857 }
 858
 859 void iscsit_clear_ooo_cmdsns_for_conn(struct iscsi_conn *conn)
 860 {
 861         struct iscsi_ooo_cmdsn *ooo_cmdsn;
 862         struct iscsi_session *sess = conn->sess;
 863
 864         mutex_lock(&sess->cmdsn_mutex);
 865         list_for_each_entry(ooo_cmdsn, &sess->sess_ooo_cmdsn_list, ooo_list) {
 866                 if (ooo_cmdsn->cid != conn->cid)
 867                         continue;
 868
 869                 ooo_cmdsn->cmd = NULL;
 870         }
 871         mutex_unlock(&sess->cmdsn_mutex);
 872 }
 873
 874 /*
 875  *      Called with sess->cmdsn_mutex held.
 876  */
 877 int iscsit_execute_ooo_cmdsns(struct iscsi_session *sess)
 878 {
 879         int ooo_count = 0;
 880         struct iscsi_cmd *cmd = NULL;
 881         struct iscsi_ooo_cmdsn *ooo_cmdsn, *ooo_cmdsn_tmp;
 882
 883         list_for_each_entry_safe(ooo_cmdsn, ooo_cmdsn_tmp,
 884                                 &sess->sess_ooo_cmdsn_list, ooo_list) {
 885                 if (ooo_cmdsn->cmdsn != sess->exp_cmd_sn)
 886                         continue;
 887
 888                 if (!ooo_cmdsn->cmd) {
 889                         sess->exp_cmd_sn++;
 890                         iscsit_remove_ooo_cmdsn(sess, ooo_cmdsn);
 891                         continue;
 892                 }
 893
 894                 cmd = ooo_cmdsn->cmd;
 895                 cmd->i_state = cmd->deferred_i_state;
 896                 ooo_count++;
 897                 sess->exp_cmd_sn++;
 898                 pr_debug("Executing out of order CmdSN: 0x%08x,"
 899                         " incremented ExpCmdSN to 0x%08x.\n",
 900                         cmd->cmd_sn, sess->exp_cmd_sn);
 901
 902                 iscsit_remove_ooo_cmdsn(sess, ooo_cmdsn);
 903
 904                 if (iscsit_execute_cmd(cmd, 1) < 0)
 905                         return -1;
 906
 907                 continue;
 908         }
 909
 910         return ooo_count;
 911 }
 912
 913 /*
 914  *      Called either:
 915  *
 916  *      1. With sess->cmdsn_mutex held from iscsi_execute_ooo_cmdsns()
 917  *      or iscsi_check_received_cmdsn().
 918  *      2. With no locks held directly from iscsi_handle_XXX_pdu() functions
 919  *      for immediate commands.
 920  */
 921 int iscsit_execute_cmd(struct iscsi_cmd *cmd, int ooo)
 922 {
 923         struct se_cmd *se_cmd = &cmd->se_cmd;
 924         struct iscsi_conn *conn = cmd->conn;
 925         int lr = 0;
 926
 927         spin_lock_bh(&cmd->istate_lock);
 928         if (ooo)
 929                 cmd->cmd_flags &= ~ICF_OOO_CMDSN;
 930
 931         switch (cmd->iscsi_opcode) {
 932         case ISCSI_OP_SCSI_CMD:
 933                 /*
 934                  * Go ahead and send the CHECK_CONDITION status for
 935                  * any SCSI CDB exceptions that may have occurred.
 936                  */
 937                 if (cmd->sense_reason) {
 938                         if (cmd->sense_reason == TCM_RESERVATION_CONFLICT) {
 939                                 cmd->i_state = ISTATE_SEND_STATUS;
 940                                 spin_unlock_bh(&cmd->istate_lock);
 941                                 iscsit_add_cmd_to_response_queue(cmd, cmd->conn,
 942                                                 cmd->i_state);
 943                                 return 0;
 944                         }
 945                         spin_unlock_bh(&cmd->istate_lock);
 946                         /*
 947                          * Determine if delayed TASK_ABORTED status for WRITEs
 948                          * should be sent now if no unsolicited data out
 949                          * payloads are expected, or if the delayed status
 950                          * should be sent after unsolicited data out with
 951                          * ISCSI_FLAG_CMD_FINAL set in iscsi_handle_data_out()
 952                          */
 953                         if (transport_check_aborted_status(se_cmd,
 954                                         (cmd->unsolicited_data == 0)) != 0)
 955                                 return 0;
 956                         /*
 957                          * Otherwise send CHECK_CONDITION and sense for
 958                          * exception
 959                          */
 960                         return transport_send_check_condition_and_sense(se_cmd,
 961                                         cmd->sense_reason, 0);
 962                 }
 963                 /*
 964                  * Special case for delayed CmdSN with Immediate
 965                  * Data and/or Unsolicited Data Out attached.
 966                  */
 967                 if (cmd->immediate_data) {
 968                         if (cmd->cmd_flags & ICF_GOT_LAST_DATAOUT) {
 969                                 spin_unlock_bh(&cmd->istate_lock);
 970                                 target_execute_cmd(&cmd->se_cmd);
 971                                 return 0;
 972                         }
 973                         spin_unlock_bh(&cmd->istate_lock);
 974
 975                         if (!(cmd->cmd_flags &
 976                                         ICF_NON_IMMEDIATE_UNSOLICITED_DATA)) {
 977                                 /*
 978                                  * Send the delayed TASK_ABORTED status for
 979                                  * WRITEs if no more unsolicitied data is
 980                                  * expected.
 981                                  */
 982                                 if (transport_check_aborted_status(se_cmd, 1)
 983                                                 != 0)
 984                                         return 0;
 985
 986                                 iscsit_set_dataout_sequence_values(cmd);
 987                                 conn->conn_transport->iscsit_get_dataout(conn, cmd, false);
 988                         }
 989                         return 0;
 990                 }
 991                 /*
 992                  * The default handler.
 993                  */
 994                 spin_unlock_bh(&cmd->istate_lock);
 995
 996                 if ((cmd->data_direction == DMA_TO_DEVICE) &&
 997                     !(cmd->cmd_flags & ICF_NON_IMMEDIATE_UNSOLICITED_DATA)) {
 998                         /*
 999                          * Send the delayed TASK_ABORTED status for WRITEs if
1000                          * no more nsolicitied data is expected.
1001                          */
1002                         if (transport_check_aborted_status(se_cmd, 1) != 0)
1003                                 return 0;
1004
1005                         iscsit_set_unsoliticed_dataout(cmd);
1006                 }
1007                 return transport_handle_cdb_direct(&cmd->se_cmd);
1008
1009         case ISCSI_OP_NOOP_OUT:
1010         case ISCSI_OP_TEXT:
1011                 spin_unlock_bh(&cmd->istate_lock);
1012                 iscsit_add_cmd_to_response_queue(cmd, cmd->conn, cmd->i_state);
1013                 break;
1014         case ISCSI_OP_SCSI_TMFUNC:
1015                 if (cmd->se_cmd.se_tmr_req->response) {
1016                         spin_unlock_bh(&cmd->istate_lock);
1017                         iscsit_add_cmd_to_response_queue(cmd, cmd->conn,
1018                                         cmd->i_state);
1019                         return 0;
1020                 }
1021                 spin_unlock_bh(&cmd->istate_lock);
1022
1023                 return transport_generic_handle_tmr(&cmd->se_cmd);
1024         case ISCSI_OP_LOGOUT:
1025                 spin_unlock_bh(&cmd->istate_lock);
1026                 switch (cmd->logout_reason) {
1027                 case ISCSI_LOGOUT_REASON_CLOSE_SESSION:
1028                         lr = iscsit_logout_closesession(cmd, cmd->conn);
1029                         break;
1030                 case ISCSI_LOGOUT_REASON_CLOSE_CONNECTION:
1031                         lr = iscsit_logout_closeconnection(cmd, cmd->conn);
1032                         break;
1033                 case ISCSI_LOGOUT_REASON_RECOVERY:
1034                         lr = iscsit_logout_removeconnforrecovery(cmd, cmd->conn);
1035                         break;
1036                 default:
1037                         pr_err("Unknown iSCSI Logout Request Code:"
1038                                 " 0x%02x\n", cmd->logout_reason);
1039                         return -1;
1040                 }
1041
1042                 return lr;
1043         default:
1044                 spin_unlock_bh(&cmd->istate_lock);
1045                 pr_err("Cannot perform out of order execution for"
1046                 " unknown iSCSI Opcode: 0x%02x\n", cmd->iscsi_opcode);
1047                 return -1;
1048         }
1049
1050         return 0;
1051 }
1052
1053 void iscsit_free_all_ooo_cmdsns(struct iscsi_session *sess)
1054 {
1055         struct iscsi_ooo_cmdsn *ooo_cmdsn, *ooo_cmdsn_tmp;
1056
1057         mutex_lock(&sess->cmdsn_mutex);
1058         list_for_each_entry_safe(ooo_cmdsn, ooo_cmdsn_tmp,
1059                         &sess->sess_ooo_cmdsn_list, ooo_list) {
1060
1061                 list_del(&ooo_cmdsn->ooo_list);
1062                 kmem_cache_free(lio_ooo_cache, ooo_cmdsn);
1063         }
1064         mutex_unlock(&sess->cmdsn_mutex);
1065 }
1066
1067 int iscsit_handle_ooo_cmdsn(
1068         struct iscsi_session *sess,
1069         struct iscsi_cmd *cmd,
1070         u32 cmdsn)
1071 {
1072         int batch = 0;
1073         struct iscsi_ooo_cmdsn *ooo_cmdsn = NULL, *ooo_tail = NULL;
1074
1075         cmd->deferred_i_state           = cmd->i_state;
1076         cmd->i_state                    = ISTATE_DEFERRED_CMD;
1077         cmd->cmd_flags                  |= ICF_OOO_CMDSN;
1078
1079         if (list_empty(&sess->sess_ooo_cmdsn_list))
1080                 batch = 1;
1081         else {
1082                 ooo_tail = list_entry(sess->sess_ooo_cmdsn_list.prev,
1083                                 typeof(*ooo_tail), ooo_list);
1084                 if (ooo_tail->cmdsn != (cmdsn - 1))
1085                         batch = 1;
1086         }
1087
1088         ooo_cmdsn = iscsit_allocate_ooo_cmdsn();
1089         if (!ooo_cmdsn)
1090                 return -ENOMEM;
1091
1092         ooo_cmdsn->cmd                  = cmd;
1093         ooo_cmdsn->batch_count          = (batch) ?
1094                                           (cmdsn - sess->exp_cmd_sn) : 1;
1095         ooo_cmdsn->cid                  = cmd->conn->cid;
1096         ooo_cmdsn->exp_cmdsn            = sess->exp_cmd_sn;
1097         ooo_cmdsn->cmdsn                = cmdsn;
1098
1099         if (iscsit_attach_ooo_cmdsn(sess, ooo_cmdsn) < 0) {
1100                 kmem_cache_free(lio_ooo_cache, ooo_cmdsn);
1101                 return -ENOMEM;
1102         }
1103
1104         return 0;
1105 }
1106
1107 static int iscsit_set_dataout_timeout_values(
1108         struct iscsi_cmd *cmd,
1109         u32 *offset,
1110         u32 *length)
1111 {
1112         struct iscsi_conn *conn = cmd->conn;
1113         struct iscsi_r2t *r2t;
1114
1115         if (cmd->unsolicited_data) {
1116                 *offset = 0;
1117                 *length = (conn->sess->sess_ops->FirstBurstLength >
1118                            cmd->se_cmd.data_length) ?
1119                            cmd->se_cmd.data_length :
1120                            conn->sess->sess_ops->FirstBurstLength;
1121                 return 0;
1122         }
1123
1124         spin_lock_bh(&cmd->r2t_lock);
1125         if (list_empty(&cmd->cmd_r2t_list)) {
1126                 pr_err("cmd->cmd_r2t_list is empty!\n");
1127                 spin_unlock_bh(&cmd->r2t_lock);
1128                 return -1;
1129         }
1130
1131         list_for_each_entry(r2t, &cmd->cmd_r2t_list, r2t_list) {
1132                 if (r2t->sent_r2t && !r2t->recovery_r2t && !r2t->seq_complete) {
1133                         *offset = r2t->offset;
1134                         *length = r2t->xfer_len;
1135                         spin_unlock_bh(&cmd->r2t_lock);
1136                         return 0;
1137                 }
1138         }
1139         spin_unlock_bh(&cmd->r2t_lock);
1140
1141         pr_err("Unable to locate any incomplete DataOUT"
1142                 " sequences for ITT: 0x%08x.\n", cmd->init_task_tag);
1143
1144         return -1;
1145 }
1146
1147 /*
1148  *      NOTE: Called from interrupt (timer) context.
1149  */
1150 void iscsit_handle_dataout_timeout(struct timer_list *t)
1151 {
1152         u32 pdu_length = 0, pdu_offset = 0;
1153         u32 r2t_length = 0, r2t_offset = 0;
1154         struct iscsi_cmd *cmd = from_timer(cmd, t, dataout_timer);
1155         struct iscsi_conn *conn = cmd->conn;
1156         struct iscsi_session *sess = NULL;
1157         struct iscsi_node_attrib *na;
1158
1159         iscsit_inc_conn_usage_count(conn);
1160
1161         spin_lock_bh(&cmd->dataout_timeout_lock);
1162         if (cmd->dataout_timer_flags & ISCSI_TF_STOP) {
1163                 spin_unlock_bh(&cmd->dataout_timeout_lock);
1164                 iscsit_dec_conn_usage_count(conn);
1165                 return;
1166         }
1167         cmd->dataout_timer_flags &= ~ISCSI_TF_RUNNING;
1168         sess = conn->sess;
1169         na = iscsit_tpg_get_node_attrib(sess);
1170
1171         if (!sess->sess_ops->ErrorRecoveryLevel) {
1172                 pr_debug("Unable to recover from DataOut timeout while"
1173                         " in ERL=0.\n");
1174                 goto failure;
1175         }
1176
1177         if (++cmd->dataout_timeout_retries == na->dataout_timeout_retries) {
1178                 pr_debug("Command ITT: 0x%08x exceeded max retries"
1179                         " for DataOUT timeout %u, closing iSCSI connection.\n",
1180                         cmd->init_task_tag, na->dataout_timeout_retries);
1181                 goto failure;
1182         }
1183
1184         cmd->cmd_flags |= ICF_WITHIN_COMMAND_RECOVERY;
1185
1186         if (conn->sess->sess_ops->DataSequenceInOrder) {
1187                 if (conn->sess->sess_ops->DataPDUInOrder) {
1188                         pdu_offset = cmd->write_data_done;
1189                         if ((pdu_offset + (conn->sess->sess_ops->MaxBurstLength -
1190                              cmd->next_burst_len)) > cmd->se_cmd.data_length)
1191                                 pdu_length = (cmd->se_cmd.data_length -
1192                                         cmd->write_data_done);
1193                         else
1194                                 pdu_length = (conn->sess->sess_ops->MaxBurstLength -
1195                                                 cmd->next_burst_len);
1196                 } else {
1197                         pdu_offset = cmd->seq_start_offset;
1198                         pdu_length = (cmd->seq_end_offset -
1199                                 cmd->seq_start_offset);
1200                 }
1201         } else {
1202                 if (iscsit_set_dataout_timeout_values(cmd, &pdu_offset,
1203                                 &pdu_length) < 0)
1204                         goto failure;
1205         }
1206
1207         if (iscsit_recalculate_dataout_values(cmd, pdu_offset, pdu_length,
1208                         &r2t_offset, &r2t_length) < 0)
1209                 goto failure;
1210
1211         pr_debug("Command ITT: 0x%08x timed out waiting for"
1212                 " completion of %sDataOUT Sequence Offset: %u, Length: %u\n",
1213                 cmd->init_task_tag, (cmd->unsolicited_data) ? "Unsolicited " :
1214                 "", r2t_offset, r2t_length);
1215
1216         if (iscsit_send_recovery_r2t(cmd, r2t_offset, r2t_length) < 0)
1217                 goto failure;
1218
1219         iscsit_start_dataout_timer(cmd, conn);
1220         spin_unlock_bh(&cmd->dataout_timeout_lock);
1221         iscsit_dec_conn_usage_count(conn);
1222
1223         return;
1224
1225 failure:
1226         spin_unlock_bh(&cmd->dataout_timeout_lock);
1227         iscsit_cause_connection_reinstatement(conn, 0);
1228         iscsit_dec_conn_usage_count(conn);
1229 }
1230
1231 void iscsit_mod_dataout_timer(struct iscsi_cmd *cmd)
1232 {
1233         struct iscsi_conn *conn = cmd->conn;
1234         struct iscsi_session *sess = conn->sess;
1235         struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
1236
1237         spin_lock_bh(&cmd->dataout_timeout_lock);
1238         if (!(cmd->dataout_timer_flags & ISCSI_TF_RUNNING)) {
1239                 spin_unlock_bh(&cmd->dataout_timeout_lock);
1240                 return;
1241         }
1242
1243         mod_timer(&cmd->dataout_timer,
1244                 (get_jiffies_64() + na->dataout_timeout * HZ));
1245         pr_debug("Updated DataOUT timer for ITT: 0x%08x",
1246                         cmd->init_task_tag);
1247         spin_unlock_bh(&cmd->dataout_timeout_lock);
1248 }
1249
1250 /*
1251  *      Called with cmd->dataout_timeout_lock held.
1252  */
1253 void iscsit_start_dataout_timer(
1254         struct iscsi_cmd *cmd,
1255         struct iscsi_conn *conn)
1256 {
1257         struct iscsi_session *sess = conn->sess;
1258         struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
1259
1260         if (cmd->dataout_timer_flags & ISCSI_TF_RUNNING)
1261                 return;
1262
1263         pr_debug("Starting DataOUT timer for ITT: 0x%08x on"
1264                 " CID: %hu.\n", cmd->init_task_tag, conn->cid);
1265
1266         cmd->dataout_timer_flags &= ~ISCSI_TF_STOP;
1267         cmd->dataout_timer_flags |= ISCSI_TF_RUNNING;
1268         mod_timer(&cmd->dataout_timer, jiffies + na->dataout_timeout * HZ);
1269 }
1270
1271 void iscsit_stop_dataout_timer(struct iscsi_cmd *cmd)
1272 {
1273         spin_lock_bh(&cmd->dataout_timeout_lock);
1274         if (!(cmd->dataout_timer_flags & ISCSI_TF_RUNNING)) {
1275                 spin_unlock_bh(&cmd->dataout_timeout_lock);
1276                 return;
1277         }
1278         cmd->dataout_timer_flags |= ISCSI_TF_STOP;
1279         spin_unlock_bh(&cmd->dataout_timeout_lock);
1280
1281         del_timer_sync(&cmd->dataout_timer);
1282
1283         spin_lock_bh(&cmd->dataout_timeout_lock);
1284         cmd->dataout_timer_flags &= ~ISCSI_TF_RUNNING;
1285         pr_debug("Stopped DataOUT Timer for ITT: 0x%08x\n",
1286                         cmd->init_task_tag);
1287         spin_unlock_bh(&cmd->dataout_timeout_lock);
1288 }
1289 EXPORT_SYMBOL(iscsit_stop_dataout_timer);