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 <scsi/iscsi_proto.h>
  21 #include <target/target_core_base.h>
  22 #include <target/target_core_fabric.h>
  23 #include <target/iscsi/iscsi_transport.h>
  24
  25 #include "iscsi_target_core.h"
  26 #include "iscsi_target_seq_pdu_list.h"
  27 #include "iscsi_target_datain_values.h"
  28 #include "iscsi_target_device.h"
  29 #include "iscsi_target_tpg.h"
  30 #include "iscsi_target_util.h"
  31 #include "iscsi_target_erl0.h"
  32 #include "iscsi_target_erl1.h"
  33 #include "iscsi_target_erl2.h"
  34 #include "iscsi_target.h"
  35
  36 #define OFFLOAD_BUF_SIZE        32768
  37
  38 /*
  39  *      Used to dump excess datain payload for certain error recovery
  40  *      situations.  Receive in OFFLOAD_BUF_SIZE max of datain per rx_data().
  41  *
  42  *      dump_padding_digest denotes if padding and data digests need
  43  *      to be dumped.
  44  */
  45 int iscsit_dump_data_payload(
  46         struct iscsi_conn *conn,
  47         u32 buf_len,
  48         int dump_padding_digest)
  49 {
  50         char *buf, pad_bytes[4];
  51         int ret = DATAOUT_WITHIN_COMMAND_RECOVERY, rx_got;
  52         u32 length, padding, offset = 0, size;
  53         struct kvec iov;
  54
  55         if (conn->sess->sess_ops->RDMAExtensions)
  56                 return 0;
  57
  58         length = (buf_len > OFFLOAD_BUF_SIZE) ? OFFLOAD_BUF_SIZE : buf_len;
  59
  60         buf = kzalloc(length, GFP_ATOMIC);
  61         if (!buf) {
  62                 pr_err("Unable to allocate %u bytes for offload"
  63                                 " buffer.\n", length);
  64                 return -1;
  65         }
  66         memset(&iov, 0, sizeof(struct kvec));
  67
  68         while (offset < buf_len) {
  69                 size = ((offset + length) > buf_len) ?
  70                         (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,
 164                                         ISCSI_REASON_PROTOCOL_ERROR, buf);
 165         }
 166
 167         if (runlength) {
 168                 if ((begrun + runlength) > cmd->r2t_sn) {
 169                         pr_err("Command ITT: 0x%08x received R2T SNACK"
 170                         " with BegRun: 0x%08x, RunLength: 0x%08x, exceeds"
 171                         " current R2TSN: 0x%08x, protocol error.\n",
 172                         cmd->init_task_tag, begrun, runlength, cmd->r2t_sn);
 173                         return iscsit_reject_cmd(cmd,
 174                                         ISCSI_REASON_BOOKMARK_INVALID, buf);
 175                 }
 176                 last_r2tsn = (begrun + runlength);
 177         } else
 178                 last_r2tsn = cmd->r2t_sn;
 179
 180         while (begrun < last_r2tsn) {
 181                 r2t = iscsit_get_holder_for_r2tsn(cmd, begrun);
 182                 if (!r2t)
 183                         return -1;
 184                 if (iscsit_send_recovery_r2t_for_snack(cmd, r2t) < 0)
 185                         return -1;
 186
 187                 begrun++;
 188         }
 189
 190         return 0;
 191 }
 192
 193 /*
 194  *      Generates Offsets and NextBurstLength based on Begrun and Runlength
 195  *      carried in a Data SNACK or ExpDataSN in TMR TASK_REASSIGN.
 196  *
 197  *      For DataSequenceInOrder=Yes and DataPDUInOrder=[Yes,No] only.
 198  *
 199  *      FIXME: How is this handled for a RData SNACK?
 200  */
 201 int iscsit_create_recovery_datain_values_datasequenceinorder_yes(
 202         struct iscsi_cmd *cmd,
 203         struct iscsi_datain_req *dr)
 204 {
 205         u32 data_sn = 0, data_sn_count = 0;
 206         u32 pdu_start = 0, seq_no = 0;
 207         u32 begrun = dr->begrun;
 208         struct iscsi_conn *conn = cmd->conn;
 209
 210         while (begrun > data_sn++) {
 211                 data_sn_count++;
 212                 if ((dr->next_burst_len +
 213                      conn->conn_ops->MaxRecvDataSegmentLength) <
 214                      conn->sess->sess_ops->MaxBurstLength) {
 215                         dr->read_data_done +=
 216                                 conn->conn_ops->MaxRecvDataSegmentLength;
 217                         dr->next_burst_len +=
 218                                 conn->conn_ops->MaxRecvDataSegmentLength;
 219                 } else {
 220                         dr->read_data_done +=
 221                                 (conn->sess->sess_ops->MaxBurstLength -
 222                                  dr->next_burst_len);
 223                         dr->next_burst_len = 0;
 224                         pdu_start += data_sn_count;
 225                         data_sn_count = 0;
 226                         seq_no++;
 227                 }
 228         }
 229
 230         if (!conn->sess->sess_ops->DataPDUInOrder) {
 231                 cmd->seq_no = seq_no;
 232                 cmd->pdu_start = pdu_start;
 233                 cmd->pdu_send_order = data_sn_count;
 234         }
 235
 236         return 0;
 237 }
 238
 239 /*
 240  *      Generates Offsets and NextBurstLength based on Begrun and Runlength
 241  *      carried in a Data SNACK or ExpDataSN in TMR TASK_REASSIGN.
 242  *
 243  *      For DataSequenceInOrder=No and DataPDUInOrder=[Yes,No] only.
 244  *
 245  *      FIXME: How is this handled for a RData SNACK?
 246  */
 247 int iscsit_create_recovery_datain_values_datasequenceinorder_no(
 248         struct iscsi_cmd *cmd,
 249         struct iscsi_datain_req *dr)
 250 {
 251         int found_seq = 0, i;
 252         u32 data_sn, read_data_done = 0, seq_send_order = 0;
 253         u32 begrun = dr->begrun;
 254         u32 runlength = dr->runlength;
 255         struct iscsi_conn *conn = cmd->conn;
 256         struct iscsi_seq *first_seq = NULL, *seq = NULL;
 257
 258         if (!cmd->seq_list) {
 259                 pr_err("struct iscsi_cmd->seq_list is NULL!\n");
 260                 return -1;
 261         }
 262
 263         /*
 264          * Calculate read_data_done for all sequences containing a
 265          * first_datasn and last_datasn less than the BegRun.
 266          *
 267          * Locate the struct iscsi_seq the BegRun lies within and calculate
 268          * NextBurstLenghth up to the DataSN based on MaxRecvDataSegmentLength.
 269          *
 270          * Also use struct iscsi_seq->seq_send_order to determine where to start.
 271          */
 272         for (i = 0; i < cmd->seq_count; i++) {
 273                 seq = &cmd->seq_list[i];
 274
 275                 if (!seq->seq_send_order)
 276                         first_seq = seq;
 277
 278                 /*
 279                  * No data has been transferred for this DataIN sequence, so the
 280                  * seq->first_datasn and seq->last_datasn have not been set.
 281                  */
 282                 if (!seq->sent) {
 283                         pr_err("Ignoring non-sent sequence 0x%08x ->"
 284                                 " 0x%08x\n\n", seq->first_datasn,
 285                                 seq->last_datasn);
 286                         continue;
 287                 }
 288
 289                 /*
 290                  * This DataIN sequence is precedes the received BegRun, add the
 291                  * total xfer_len of the sequence to read_data_done and reset
 292                  * seq->pdu_send_order.
 293                  */
 294                 if ((seq->first_datasn < begrun) &&
 295                                 (seq->last_datasn < begrun)) {
 296                         pr_err("Pre BegRun sequence 0x%08x ->"
 297                                 " 0x%08x\n", seq->first_datasn,
 298                                 seq->last_datasn);
 299
 300                         read_data_done += cmd->seq_list[i].xfer_len;
 301                         seq->next_burst_len = seq->pdu_send_order = 0;
 302                         continue;
 303                 }
 304
 305                 /*
 306                  * The BegRun lies within this DataIN sequence.
 307                  */
 308                 if ((seq->first_datasn <= begrun) &&
 309                                 (seq->last_datasn >= begrun)) {
 310                         pr_err("Found sequence begrun: 0x%08x in"
 311                                 " 0x%08x -> 0x%08x\n", begrun,
 312                                 seq->first_datasn, seq->last_datasn);
 313
 314                         seq_send_order = seq->seq_send_order;
 315                         data_sn = seq->first_datasn;
 316                         seq->next_burst_len = seq->pdu_send_order = 0;
 317                         found_seq = 1;
 318
 319                         /*
 320                          * For DataPDUInOrder=Yes, while the first DataSN of
 321                          * the sequence is less than the received BegRun, add
 322                          * the MaxRecvDataSegmentLength to read_data_done and
 323                          * to the sequence's next_burst_len;
 324                          *
 325                          * For DataPDUInOrder=No, while the first DataSN of the
 326                          * sequence is less than the received BegRun, find the
 327                          * struct iscsi_pdu of the DataSN in question and add the
 328                          * MaxRecvDataSegmentLength to read_data_done and to the
 329                          * sequence's next_burst_len;
 330                          */
 331                         if (conn->sess->sess_ops->DataPDUInOrder) {
 332                                 while (data_sn < begrun) {
 333                                         seq->pdu_send_order++;
 334                                         read_data_done +=
 335                                                 conn->conn_ops->MaxRecvDataSegmentLength;
 336                                         seq->next_burst_len +=
 337                                                 conn->conn_ops->MaxRecvDataSegmentLength;
 338                                         data_sn++;
 339                                 }
 340                         } else {
 341                                 int j;
 342                                 struct iscsi_pdu *pdu;
 343
 344                                 while (data_sn < begrun) {
 345                                         seq->pdu_send_order++;
 346
 347                                         for (j = 0; j < seq->pdu_count; j++) {
 348                                                 pdu = &cmd->pdu_list[
 349                                                         seq->pdu_start + j];
 350                                                 if (pdu->data_sn == data_sn) {
 351                                                         read_data_done +=
 352                                                                 pdu->length;
 353                                                         seq->next_burst_len +=
 354                                                                 pdu->length;
 355                                                 }
 356                                         }
 357                                         data_sn++;
 358                                 }
 359                         }
 360                         continue;
 361                 }
 362
 363                 /*
 364                  * This DataIN sequence is larger than the received BegRun,
 365                  * reset seq->pdu_send_order and continue.
 366                  */
 367                 if ((seq->first_datasn > begrun) ||
 368                                 (seq->last_datasn > begrun)) {
 369                         pr_err("Post BegRun sequence 0x%08x -> 0x%08x\n",
 370                                         seq->first_datasn, seq->last_datasn);
 371
 372                         seq->next_burst_len = seq->pdu_send_order = 0;
 373                         continue;
 374                 }
 375         }
 376
 377         if (!found_seq) {
 378                 if (!begrun) {
 379                         if (!first_seq) {
 380                                 pr_err("ITT: 0x%08x, Begrun: 0x%08x"
 381                                         " but first_seq is NULL\n",
 382                                         cmd->init_task_tag, begrun);
 383                                 return -1;
 384                         }
 385                         seq_send_order = first_seq->seq_send_order;
 386                         seq->next_burst_len = seq->pdu_send_order = 0;
 387                         goto done;
 388                 }
 389
 390                 pr_err("Unable to locate struct iscsi_seq for ITT: 0x%08x,"
 391                         " BegRun: 0x%08x, RunLength: 0x%08x while"
 392                         " DataSequenceInOrder=No and DataPDUInOrder=%s.\n",
 393                                 cmd->init_task_tag, begrun, runlength,
 394                         (conn->sess->sess_ops->DataPDUInOrder) ? "Yes" : "No");
 395                 return -1;
 396         }
 397
 398 done:
 399         dr->read_data_done = read_data_done;
 400         dr->seq_send_order = seq_send_order;
 401
 402         return 0;
 403 }
 404
 405 static int iscsit_handle_recovery_datain(
 406         struct iscsi_cmd *cmd,
 407         unsigned char *buf,
 408         u32 begrun,
 409         u32 runlength)
 410 {
 411         struct iscsi_conn *conn = cmd->conn;
 412         struct iscsi_datain_req *dr;
 413         struct se_cmd *se_cmd = &cmd->se_cmd;
 414
 415         if (!(se_cmd->transport_state & CMD_T_COMPLETE)) {
 416                 pr_err("Ignoring ITT: 0x%08x Data SNACK\n",
 417                                 cmd->init_task_tag);
 418                 return 0;
 419         }
 420
 421         /*
 422          * Make sure the initiator is not requesting retransmission
 423          * of DataSNs already acknowledged by a Data ACK SNACK.
 424          */
 425         if ((cmd->cmd_flags & ICF_GOT_DATACK_SNACK) &&
 426             (begrun <= cmd->acked_data_sn)) {
 427                 pr_err("ITT: 0x%08x, Data SNACK requesting"
 428                         " retransmission of DataSN: 0x%08x to 0x%08x but"
 429                         " already acked to DataSN: 0x%08x by Data ACK SNACK,"
 430                         " protocol error.\n", cmd->init_task_tag, begrun,
 431                         (begrun + runlength), cmd->acked_data_sn);
 432
 433                 return iscsit_reject_cmd(cmd, ISCSI_REASON_PROTOCOL_ERROR, buf);
 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_reject_cmd(cmd, ISCSI_REASON_BOOKMARK_INVALID,
 445                                          buf);
 446         }
 447
 448         dr = iscsit_allocate_datain_req();
 449         if (!dr)
 450                 return iscsit_reject_cmd(cmd, ISCSI_REASON_BOOKMARK_NO_RESOURCES,
 451                                          buf);
 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 (iscsi_sna_lt(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 (iscsi_sna_lt(ooo_tmp->cmdsn, ooo_cmdsn->cmdsn))
 833                                         continue;
 834
 835                                 /* Insert before this entry */
 836                                 list_add(&ooo_cmdsn->ooo_list,
 837                                         ooo_tmp->ooo_list.prev);
 838                                 break;
 839                         }
 840                 }
 841         }
 842
 843         return 0;
 844 }
 845
 846 /*
 847  *      Removes an struct iscsi_ooo_cmdsn from a session's list,
 848  *      called with struct iscsi_session->cmdsn_mutex held.
 849  */
 850 void iscsit_remove_ooo_cmdsn(
 851         struct iscsi_session *sess,
 852         struct iscsi_ooo_cmdsn *ooo_cmdsn)
 853 {
 854         list_del(&ooo_cmdsn->ooo_list);
 855         kmem_cache_free(lio_ooo_cache, ooo_cmdsn);
 856 }
 857
 858 void iscsit_clear_ooo_cmdsns_for_conn(struct iscsi_conn *conn)
 859 {
 860         struct iscsi_ooo_cmdsn *ooo_cmdsn;
 861         struct iscsi_session *sess = conn->sess;
 862
 863         mutex_lock(&sess->cmdsn_mutex);
 864         list_for_each_entry(ooo_cmdsn, &sess->sess_ooo_cmdsn_list, ooo_list) {
 865                 if (ooo_cmdsn->cid != conn->cid)
 866                         continue;
 867
 868                 ooo_cmdsn->cmd = NULL;
 869         }
 870         mutex_unlock(&sess->cmdsn_mutex);
 871 }
 872
 873 /*
 874  *      Called with sess->cmdsn_mutex held.
 875  */
 876 int iscsit_execute_ooo_cmdsns(struct iscsi_session *sess)
 877 {
 878         int ooo_count = 0;
 879         struct iscsi_cmd *cmd = NULL;
 880         struct iscsi_ooo_cmdsn *ooo_cmdsn, *ooo_cmdsn_tmp;
 881
 882         list_for_each_entry_safe(ooo_cmdsn, ooo_cmdsn_tmp,
 883                                 &sess->sess_ooo_cmdsn_list, ooo_list) {
 884                 if (ooo_cmdsn->cmdsn != sess->exp_cmd_sn)
 885                         continue;
 886
 887                 if (!ooo_cmdsn->cmd) {
 888                         sess->exp_cmd_sn++;
 889                         iscsit_remove_ooo_cmdsn(sess, ooo_cmdsn);
 890                         continue;
 891                 }
 892
 893                 cmd = ooo_cmdsn->cmd;
 894                 cmd->i_state = cmd->deferred_i_state;
 895                 ooo_count++;
 896                 sess->exp_cmd_sn++;
 897                 pr_debug("Executing out of order CmdSN: 0x%08x,"
 898                         " incremented ExpCmdSN to 0x%08x.\n",
 899                         cmd->cmd_sn, sess->exp_cmd_sn);
 900
 901                 iscsit_remove_ooo_cmdsn(sess, ooo_cmdsn);
 902
 903                 if (iscsit_execute_cmd(cmd, 1) < 0)
 904                         return -1;
 905
 906                 continue;
 907         }
 908
 909         return ooo_count;
 910 }
 911
 912 /*
 913  *      Called either:
 914  *
 915  *      1. With sess->cmdsn_mutex held from iscsi_execute_ooo_cmdsns()
 916  *      or iscsi_check_received_cmdsn().
 917  *      2. With no locks held directly from iscsi_handle_XXX_pdu() functions
 918  *      for immediate commands.
 919  */
 920 int iscsit_execute_cmd(struct iscsi_cmd *cmd, int ooo)
 921 {
 922         struct se_cmd *se_cmd = &cmd->se_cmd;
 923         struct iscsi_conn *conn = cmd->conn;
 924         int lr = 0;
 925
 926         spin_lock_bh(&cmd->istate_lock);
 927         if (ooo)
 928                 cmd->cmd_flags &= ~ICF_OOO_CMDSN;
 929
 930         switch (cmd->iscsi_opcode) {
 931         case ISCSI_OP_SCSI_CMD:
 932                 /*
 933                  * Go ahead and send the CHECK_CONDITION status for
 934                  * any SCSI CDB exceptions that may have occurred.
 935                  */
 936                 if (cmd->sense_reason) {
 937                         if (cmd->sense_reason == TCM_RESERVATION_CONFLICT) {
 938                                 cmd->i_state = ISTATE_SEND_STATUS;
 939                                 spin_unlock_bh(&cmd->istate_lock);
 940                                 iscsit_add_cmd_to_response_queue(cmd, cmd->conn,
 941                                                 cmd->i_state);
 942                                 return 0;
 943                         }
 944                         spin_unlock_bh(&cmd->istate_lock);
 945                         /*
 946                          * Determine if delayed TASK_ABORTED status for WRITEs
 947                          * should be sent now if no unsolicited data out
 948                          * payloads are expected, or if the delayed status
 949                          * should be sent after unsolicited data out with
 950                          * ISCSI_FLAG_CMD_FINAL set in iscsi_handle_data_out()
 951                          */
 952                         if (transport_check_aborted_status(se_cmd,
 953                                         (cmd->unsolicited_data == 0)) != 0)
 954                                 return 0;
 955                         /*
 956                          * Otherwise send CHECK_CONDITION and sense for
 957                          * exception
 958                          */
 959                         return transport_send_check_condition_and_sense(se_cmd,
 960                                         cmd->sense_reason, 0);
 961                 }
 962                 /*
 963                  * Special case for delayed CmdSN with Immediate
 964                  * Data and/or Unsolicited Data Out attached.
 965                  */
 966                 if (cmd->immediate_data) {
 967                         if (cmd->cmd_flags & ICF_GOT_LAST_DATAOUT) {
 968                                 spin_unlock_bh(&cmd->istate_lock);
 969                                 target_execute_cmd(&cmd->se_cmd);
 970                                 return 0;
 971                         }
 972                         spin_unlock_bh(&cmd->istate_lock);
 973
 974                         if (!(cmd->cmd_flags &
 975                                         ICF_NON_IMMEDIATE_UNSOLICITED_DATA)) {
 976                                 /*
 977                                  * Send the delayed TASK_ABORTED status for
 978                                  * WRITEs if no more unsolicitied data is
 979                                  * expected.
 980                                  */
 981                                 if (transport_check_aborted_status(se_cmd, 1)
 982                                                 != 0)
 983                                         return 0;
 984
 985                                 iscsit_set_dataout_sequence_values(cmd);
 986                                 conn->conn_transport->iscsit_get_dataout(conn, cmd, false);
 987                         }
 988                         return 0;
 989                 }
 990                 /*
 991                  * The default handler.
 992                  */
 993                 spin_unlock_bh(&cmd->istate_lock);
 994
 995                 if ((cmd->data_direction == DMA_TO_DEVICE) &&
 996                     !(cmd->cmd_flags & ICF_NON_IMMEDIATE_UNSOLICITED_DATA)) {
 997                         /*
 998                          * Send the delayed TASK_ABORTED status for WRITEs if
 999                          * no more nsolicitied data is expected.
1000                          */
1001                         if (transport_check_aborted_status(se_cmd, 1) != 0)
1002                                 return 0;
1003
1004                         iscsit_set_unsoliticed_dataout(cmd);
1005                 }
1006                 return transport_handle_cdb_direct(&cmd->se_cmd);
1007
1008         case ISCSI_OP_NOOP_OUT:
1009         case ISCSI_OP_TEXT:
1010                 spin_unlock_bh(&cmd->istate_lock);
1011                 iscsit_add_cmd_to_response_queue(cmd, cmd->conn, cmd->i_state);
1012                 break;
1013         case ISCSI_OP_SCSI_TMFUNC:
1014                 if (cmd->se_cmd.se_tmr_req->response) {
1015                         spin_unlock_bh(&cmd->istate_lock);
1016                         iscsit_add_cmd_to_response_queue(cmd, cmd->conn,
1017                                         cmd->i_state);
1018                         return 0;
1019                 }
1020                 spin_unlock_bh(&cmd->istate_lock);
1021
1022                 return transport_generic_handle_tmr(&cmd->se_cmd);
1023         case ISCSI_OP_LOGOUT:
1024                 spin_unlock_bh(&cmd->istate_lock);
1025                 switch (cmd->logout_reason) {
1026                 case ISCSI_LOGOUT_REASON_CLOSE_SESSION:
1027                         lr = iscsit_logout_closesession(cmd, cmd->conn);
1028                         break;
1029                 case ISCSI_LOGOUT_REASON_CLOSE_CONNECTION:
1030                         lr = iscsit_logout_closeconnection(cmd, cmd->conn);
1031                         break;
1032                 case ISCSI_LOGOUT_REASON_RECOVERY:
1033                         lr = iscsit_logout_removeconnforrecovery(cmd, cmd->conn);
1034                         break;
1035                 default:
1036                         pr_err("Unknown iSCSI Logout Request Code:"
1037                                 " 0x%02x\n", cmd->logout_reason);
1038                         return -1;
1039                 }
1040
1041                 return lr;
1042         default:
1043                 spin_unlock_bh(&cmd->istate_lock);
1044                 pr_err("Cannot perform out of order execution for"
1045                 " unknown iSCSI Opcode: 0x%02x\n", cmd->iscsi_opcode);
1046                 return -1;
1047         }
1048
1049         return 0;
1050 }
1051
1052 void iscsit_free_all_ooo_cmdsns(struct iscsi_session *sess)
1053 {
1054         struct iscsi_ooo_cmdsn *ooo_cmdsn, *ooo_cmdsn_tmp;
1055
1056         mutex_lock(&sess->cmdsn_mutex);
1057         list_for_each_entry_safe(ooo_cmdsn, ooo_cmdsn_tmp,
1058                         &sess->sess_ooo_cmdsn_list, ooo_list) {
1059
1060                 list_del(&ooo_cmdsn->ooo_list);
1061                 kmem_cache_free(lio_ooo_cache, ooo_cmdsn);
1062         }
1063         mutex_unlock(&sess->cmdsn_mutex);
1064 }
1065
1066 int iscsit_handle_ooo_cmdsn(
1067         struct iscsi_session *sess,
1068         struct iscsi_cmd *cmd,
1069         u32 cmdsn)
1070 {
1071         int batch = 0;
1072         struct iscsi_ooo_cmdsn *ooo_cmdsn = NULL, *ooo_tail = NULL;
1073
1074         cmd->deferred_i_state           = cmd->i_state;
1075         cmd->i_state                    = ISTATE_DEFERRED_CMD;
1076         cmd->cmd_flags                  |= ICF_OOO_CMDSN;
1077
1078         if (list_empty(&sess->sess_ooo_cmdsn_list))
1079                 batch = 1;
1080         else {
1081                 ooo_tail = list_entry(sess->sess_ooo_cmdsn_list.prev,
1082                                 typeof(*ooo_tail), ooo_list);
1083                 if (ooo_tail->cmdsn != (cmdsn - 1))
1084                         batch = 1;
1085         }
1086
1087         ooo_cmdsn = iscsit_allocate_ooo_cmdsn();
1088         if (!ooo_cmdsn)
1089                 return -ENOMEM;
1090
1091         ooo_cmdsn->cmd                  = cmd;
1092         ooo_cmdsn->batch_count          = (batch) ?
1093                                           (cmdsn - sess->exp_cmd_sn) : 1;
1094         ooo_cmdsn->cid                  = cmd->conn->cid;
1095         ooo_cmdsn->exp_cmdsn            = sess->exp_cmd_sn;
1096         ooo_cmdsn->cmdsn                = cmdsn;
1097
1098         if (iscsit_attach_ooo_cmdsn(sess, ooo_cmdsn) < 0) {
1099                 kmem_cache_free(lio_ooo_cache, ooo_cmdsn);
1100                 return -ENOMEM;
1101         }
1102
1103         return 0;
1104 }
1105
1106 static int iscsit_set_dataout_timeout_values(
1107         struct iscsi_cmd *cmd,
1108         u32 *offset,
1109         u32 *length)
1110 {
1111         struct iscsi_conn *conn = cmd->conn;
1112         struct iscsi_r2t *r2t;
1113
1114         if (cmd->unsolicited_data) {
1115                 *offset = 0;
1116                 *length = (conn->sess->sess_ops->FirstBurstLength >
1117                            cmd->se_cmd.data_length) ?
1118                            cmd->se_cmd.data_length :
1119                            conn->sess->sess_ops->FirstBurstLength;
1120                 return 0;
1121         }
1122
1123         spin_lock_bh(&cmd->r2t_lock);
1124         if (list_empty(&cmd->cmd_r2t_list)) {
1125                 pr_err("cmd->cmd_r2t_list is empty!\n");
1126                 spin_unlock_bh(&cmd->r2t_lock);
1127                 return -1;
1128         }
1129
1130         list_for_each_entry(r2t, &cmd->cmd_r2t_list, r2t_list) {
1131                 if (r2t->sent_r2t && !r2t->recovery_r2t && !r2t->seq_complete) {
1132                         *offset = r2t->offset;
1133                         *length = r2t->xfer_len;
1134                         spin_unlock_bh(&cmd->r2t_lock);
1135                         return 0;
1136                 }
1137         }
1138         spin_unlock_bh(&cmd->r2t_lock);
1139
1140         pr_err("Unable to locate any incomplete DataOUT"
1141                 " sequences for ITT: 0x%08x.\n", cmd->init_task_tag);
1142
1143         return -1;
1144 }
1145
1146 /*
1147  *      NOTE: Called from interrupt (timer) context.
1148  */
1149 static void iscsit_handle_dataout_timeout(unsigned long data)
1150 {
1151         u32 pdu_length = 0, pdu_offset = 0;
1152         u32 r2t_length = 0, r2t_offset = 0;
1153         struct iscsi_cmd *cmd = (struct iscsi_cmd *) data;
1154         struct iscsi_conn *conn = cmd->conn;
1155         struct iscsi_session *sess = NULL;
1156         struct iscsi_node_attrib *na;
1157
1158         iscsit_inc_conn_usage_count(conn);
1159
1160         spin_lock_bh(&cmd->dataout_timeout_lock);
1161         if (cmd->dataout_timer_flags & ISCSI_TF_STOP) {
1162                 spin_unlock_bh(&cmd->dataout_timeout_lock);
1163                 iscsit_dec_conn_usage_count(conn);
1164                 return;
1165         }
1166         cmd->dataout_timer_flags &= ~ISCSI_TF_RUNNING;
1167         sess = conn->sess;
1168         na = iscsit_tpg_get_node_attrib(sess);
1169
1170         if (!sess->sess_ops->ErrorRecoveryLevel) {
1171                 pr_debug("Unable to recover from DataOut timeout while"
1172                         " in ERL=0.\n");
1173                 goto failure;
1174         }
1175
1176         if (++cmd->dataout_timeout_retries == na->dataout_timeout_retries) {
1177                 pr_debug("Command ITT: 0x%08x exceeded max retries"
1178                         " for DataOUT timeout %u, closing iSCSI connection.\n",
1179                         cmd->init_task_tag, na->dataout_timeout_retries);
1180                 goto failure;
1181         }
1182
1183         cmd->cmd_flags |= ICF_WITHIN_COMMAND_RECOVERY;
1184
1185         if (conn->sess->sess_ops->DataSequenceInOrder) {
1186                 if (conn->sess->sess_ops->DataPDUInOrder) {
1187                         pdu_offset = cmd->write_data_done;
1188                         if ((pdu_offset + (conn->sess->sess_ops->MaxBurstLength -
1189                              cmd->next_burst_len)) > cmd->se_cmd.data_length)
1190                                 pdu_length = (cmd->se_cmd.data_length -
1191                                         cmd->write_data_done);
1192                         else
1193                                 pdu_length = (conn->sess->sess_ops->MaxBurstLength -
1194                                                 cmd->next_burst_len);
1195                 } else {
1196                         pdu_offset = cmd->seq_start_offset;
1197                         pdu_length = (cmd->seq_end_offset -
1198                                 cmd->seq_start_offset);
1199                 }
1200         } else {
1201                 if (iscsit_set_dataout_timeout_values(cmd, &pdu_offset,
1202                                 &pdu_length) < 0)
1203                         goto failure;
1204         }
1205
1206         if (iscsit_recalculate_dataout_values(cmd, pdu_offset, pdu_length,
1207                         &r2t_offset, &r2t_length) < 0)
1208                 goto failure;
1209
1210         pr_debug("Command ITT: 0x%08x timed out waiting for"
1211                 " completion of %sDataOUT Sequence Offset: %u, Length: %u\n",
1212                 cmd->init_task_tag, (cmd->unsolicited_data) ? "Unsolicited " :
1213                 "", r2t_offset, r2t_length);
1214
1215         if (iscsit_send_recovery_r2t(cmd, r2t_offset, r2t_length) < 0)
1216                 goto failure;
1217
1218         iscsit_start_dataout_timer(cmd, conn);
1219         spin_unlock_bh(&cmd->dataout_timeout_lock);
1220         iscsit_dec_conn_usage_count(conn);
1221
1222         return;
1223
1224 failure:
1225         spin_unlock_bh(&cmd->dataout_timeout_lock);
1226         iscsit_cause_connection_reinstatement(conn, 0);
1227         iscsit_dec_conn_usage_count(conn);
1228 }
1229
1230 void iscsit_mod_dataout_timer(struct iscsi_cmd *cmd)
1231 {
1232         struct iscsi_conn *conn = cmd->conn;
1233         struct iscsi_session *sess = conn->sess;
1234         struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
1235
1236         spin_lock_bh(&cmd->dataout_timeout_lock);
1237         if (!(cmd->dataout_timer_flags & ISCSI_TF_RUNNING)) {
1238                 spin_unlock_bh(&cmd->dataout_timeout_lock);
1239                 return;
1240         }
1241
1242         mod_timer(&cmd->dataout_timer,
1243                 (get_jiffies_64() + na->dataout_timeout * HZ));
1244         pr_debug("Updated DataOUT timer for ITT: 0x%08x",
1245                         cmd->init_task_tag);
1246         spin_unlock_bh(&cmd->dataout_timeout_lock);
1247 }
1248
1249 /*
1250  *      Called with cmd->dataout_timeout_lock held.
1251  */
1252 void iscsit_start_dataout_timer(
1253         struct iscsi_cmd *cmd,
1254         struct iscsi_conn *conn)
1255 {
1256         struct iscsi_session *sess = conn->sess;
1257         struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
1258
1259         if (cmd->dataout_timer_flags & ISCSI_TF_RUNNING)
1260                 return;
1261
1262         pr_debug("Starting DataOUT timer for ITT: 0x%08x on"
1263                 " CID: %hu.\n", cmd->init_task_tag, conn->cid);
1264
1265         init_timer(&cmd->dataout_timer);
1266         cmd->dataout_timer.expires = (get_jiffies_64() + na->dataout_timeout * HZ);
1267         cmd->dataout_timer.data = (unsigned long)cmd;
1268         cmd->dataout_timer.function = iscsit_handle_dataout_timeout;
1269         cmd->dataout_timer_flags &= ~ISCSI_TF_STOP;
1270         cmd->dataout_timer_flags |= ISCSI_TF_RUNNING;
1271         add_timer(&cmd->dataout_timer);
1272 }
1273
1274 void iscsit_stop_dataout_timer(struct iscsi_cmd *cmd)
1275 {
1276         spin_lock_bh(&cmd->dataout_timeout_lock);
1277         if (!(cmd->dataout_timer_flags & ISCSI_TF_RUNNING)) {
1278                 spin_unlock_bh(&cmd->dataout_timeout_lock);
1279                 return;
1280         }
1281         cmd->dataout_timer_flags |= ISCSI_TF_STOP;
1282         spin_unlock_bh(&cmd->dataout_timeout_lock);
1283
1284         del_timer_sync(&cmd->dataout_timer);
1285
1286         spin_lock_bh(&cmd->dataout_timeout_lock);
1287         cmd->dataout_timer_flags &= ~ISCSI_TF_RUNNING;
1288         pr_debug("Stopped DataOUT Timer for ITT: 0x%08x\n",
1289                         cmd->init_task_tag);
1290         spin_unlock_bh(&cmd->dataout_timeout_lock);
1291 }
1292 EXPORT_SYMBOL(iscsit_stop_dataout_timer);