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;
  52         int ret = DATAOUT_WITHIN_COMMAND_RECOVERY, rx_got;
  53         u32 length, offset = 0, size;
  54         struct kvec iov;
  55
  56         if (conn->sess->sess_ops->RDMAExtensions)
  57                 return 0;
  58
  59         if (dump_padding_digest) {
  60                 buf_len = ALIGN(buf_len, 4);
  61                 if (conn->conn_ops->DataDigest)
  62                         buf_len += ISCSI_CRC_LEN;
  63         }
  64
  65         length = min(buf_len, OFFLOAD_BUF_SIZE);
  66
  67         buf = kzalloc(length, GFP_ATOMIC);
  68         if (!buf) {
  69                 pr_err("Unable to allocate %u bytes for offload"
  70                                 " buffer.\n", length);
  71                 return -1;
  72         }
  73         memset(&iov, 0, sizeof(struct kvec));
  74
  75         while (offset < buf_len) {
  76                 size = min(buf_len - offset, length);
  77
  78                 iov.iov_len = size;
  79                 iov.iov_base = buf;
  80
  81                 rx_got = rx_data(conn, &iov, 1, size);
  82                 if (rx_got != size) {
  83                         ret = DATAOUT_CANNOT_RECOVER;
  84                         break;
  85                 }
  86
  87                 offset += size;
  88         }
  89
  90         kfree(buf);
  91         return ret;
  92 }
  93
  94 /*
  95  *      Used for retransmitting R2Ts from a R2T SNACK request.
  96  */
  97 static int iscsit_send_recovery_r2t_for_snack(
  98         struct iscsi_cmd *cmd,
  99         struct iscsi_r2t *r2t)
 100 {
 101         /*
 102          * If the struct iscsi_r2t has not been sent yet, we can safely
 103          * ignore retransmission
 104          * of the R2TSN in question.
 105          */
 106         spin_lock_bh(&cmd->r2t_lock);
 107         if (!r2t->sent_r2t) {
 108                 spin_unlock_bh(&cmd->r2t_lock);
 109                 return 0;
 110         }
 111         r2t->sent_r2t = 0;
 112         spin_unlock_bh(&cmd->r2t_lock);
 113
 114         iscsit_add_cmd_to_immediate_queue(cmd, cmd->conn, ISTATE_SEND_R2T);
 115
 116         return 0;
 117 }
 118
 119 static int iscsit_handle_r2t_snack(
 120         struct iscsi_cmd *cmd,
 121         unsigned char *buf,
 122         u32 begrun,
 123         u32 runlength)
 124 {
 125         u32 last_r2tsn;
 126         struct iscsi_r2t *r2t;
 127
 128         /*
 129          * Make sure the initiator is not requesting retransmission
 130          * of R2TSNs already acknowledged by a TMR TASK_REASSIGN.
 131          */
 132         if ((cmd->cmd_flags & ICF_GOT_DATACK_SNACK) &&
 133             (begrun <= cmd->acked_data_sn)) {
 134                 pr_err("ITT: 0x%08x, R2T SNACK requesting"
 135                         " retransmission of R2TSN: 0x%08x to 0x%08x but already"
 136                         " acked to  R2TSN: 0x%08x by TMR TASK_REASSIGN,"
 137                         " protocol error.\n", cmd->init_task_tag, begrun,
 138                         (begrun + runlength), cmd->acked_data_sn);
 139
 140                 return iscsit_reject_cmd(cmd, ISCSI_REASON_PROTOCOL_ERROR, buf);
 141         }
 142
 143         if (runlength) {
 144                 if ((begrun + runlength) > cmd->r2t_sn) {
 145                         pr_err("Command ITT: 0x%08x received R2T SNACK"
 146                         " with BegRun: 0x%08x, RunLength: 0x%08x, exceeds"
 147                         " current R2TSN: 0x%08x, protocol error.\n",
 148                         cmd->init_task_tag, begrun, runlength, cmd->r2t_sn);
 149                         return iscsit_reject_cmd(cmd,
 150                                         ISCSI_REASON_BOOKMARK_INVALID, buf);
 151                 }
 152                 last_r2tsn = (begrun + runlength);
 153         } else
 154                 last_r2tsn = cmd->r2t_sn;
 155
 156         while (begrun < last_r2tsn) {
 157                 r2t = iscsit_get_holder_for_r2tsn(cmd, begrun);
 158                 if (!r2t)
 159                         return -1;
 160                 if (iscsit_send_recovery_r2t_for_snack(cmd, r2t) < 0)
 161                         return -1;
 162
 163                 begrun++;
 164         }
 165
 166         return 0;
 167 }
 168
 169 /*
 170  *      Generates Offsets and NextBurstLength based on Begrun and Runlength
 171  *      carried in a Data SNACK or ExpDataSN in TMR TASK_REASSIGN.
 172  *
 173  *      For DataSequenceInOrder=Yes and DataPDUInOrder=[Yes,No] only.
 174  *
 175  *      FIXME: How is this handled for a RData SNACK?
 176  */
 177 int iscsit_create_recovery_datain_values_datasequenceinorder_yes(
 178         struct iscsi_cmd *cmd,
 179         struct iscsi_datain_req *dr)
 180 {
 181         u32 data_sn = 0, data_sn_count = 0;
 182         u32 pdu_start = 0, seq_no = 0;
 183         u32 begrun = dr->begrun;
 184         struct iscsi_conn *conn = cmd->conn;
 185
 186         while (begrun > data_sn++) {
 187                 data_sn_count++;
 188                 if ((dr->next_burst_len +
 189                      conn->conn_ops->MaxRecvDataSegmentLength) <
 190                      conn->sess->sess_ops->MaxBurstLength) {
 191                         dr->read_data_done +=
 192                                 conn->conn_ops->MaxRecvDataSegmentLength;
 193                         dr->next_burst_len +=
 194                                 conn->conn_ops->MaxRecvDataSegmentLength;
 195                 } else {
 196                         dr->read_data_done +=
 197                                 (conn->sess->sess_ops->MaxBurstLength -
 198                                  dr->next_burst_len);
 199                         dr->next_burst_len = 0;
 200                         pdu_start += data_sn_count;
 201                         data_sn_count = 0;
 202                         seq_no++;
 203                 }
 204         }
 205
 206         if (!conn->sess->sess_ops->DataPDUInOrder) {
 207                 cmd->seq_no = seq_no;
 208                 cmd->pdu_start = pdu_start;
 209                 cmd->pdu_send_order = data_sn_count;
 210         }
 211
 212         return 0;
 213 }
 214
 215 /*
 216  *      Generates Offsets and NextBurstLength based on Begrun and Runlength
 217  *      carried in a Data SNACK or ExpDataSN in TMR TASK_REASSIGN.
 218  *
 219  *      For DataSequenceInOrder=No and DataPDUInOrder=[Yes,No] only.
 220  *
 221  *      FIXME: How is this handled for a RData SNACK?
 222  */
 223 int iscsit_create_recovery_datain_values_datasequenceinorder_no(
 224         struct iscsi_cmd *cmd,
 225         struct iscsi_datain_req *dr)
 226 {
 227         int found_seq = 0, i;
 228         u32 data_sn, read_data_done = 0, seq_send_order = 0;
 229         u32 begrun = dr->begrun;
 230         u32 runlength = dr->runlength;
 231         struct iscsi_conn *conn = cmd->conn;
 232         struct iscsi_seq *first_seq = NULL, *seq = NULL;
 233
 234         if (!cmd->seq_list) {
 235                 pr_err("struct iscsi_cmd->seq_list is NULL!\n");
 236                 return -1;
 237         }
 238
 239         /*
 240          * Calculate read_data_done for all sequences containing a
 241          * first_datasn and last_datasn less than the BegRun.
 242          *
 243          * Locate the struct iscsi_seq the BegRun lies within and calculate
 244          * NextBurstLenghth up to the DataSN based on MaxRecvDataSegmentLength.
 245          *
 246          * Also use struct iscsi_seq->seq_send_order to determine where to start.
 247          */
 248         for (i = 0; i < cmd->seq_count; i++) {
 249                 seq = &cmd->seq_list[i];
 250
 251                 if (!seq->seq_send_order)
 252                         first_seq = seq;
 253
 254                 /*
 255                  * No data has been transferred for this DataIN sequence, so the
 256                  * seq->first_datasn and seq->last_datasn have not been set.
 257                  */
 258                 if (!seq->sent) {
 259                         pr_err("Ignoring non-sent sequence 0x%08x ->"
 260                                 " 0x%08x\n\n", seq->first_datasn,
 261                                 seq->last_datasn);
 262                         continue;
 263                 }
 264
 265                 /*
 266                  * This DataIN sequence is precedes the received BegRun, add the
 267                  * total xfer_len of the sequence to read_data_done and reset
 268                  * seq->pdu_send_order.
 269                  */
 270                 if ((seq->first_datasn < begrun) &&
 271                                 (seq->last_datasn < begrun)) {
 272                         pr_err("Pre BegRun sequence 0x%08x ->"
 273                                 " 0x%08x\n", seq->first_datasn,
 274                                 seq->last_datasn);
 275
 276                         read_data_done += cmd->seq_list[i].xfer_len;
 277                         seq->next_burst_len = seq->pdu_send_order = 0;
 278                         continue;
 279                 }
 280
 281                 /*
 282                  * The BegRun lies within this DataIN sequence.
 283                  */
 284                 if ((seq->first_datasn <= begrun) &&
 285                                 (seq->last_datasn >= begrun)) {
 286                         pr_err("Found sequence begrun: 0x%08x in"
 287                                 " 0x%08x -> 0x%08x\n", begrun,
 288                                 seq->first_datasn, seq->last_datasn);
 289
 290                         seq_send_order = seq->seq_send_order;
 291                         data_sn = seq->first_datasn;
 292                         seq->next_burst_len = seq->pdu_send_order = 0;
 293                         found_seq = 1;
 294
 295                         /*
 296                          * For DataPDUInOrder=Yes, while the first DataSN of
 297                          * the sequence is less than the received BegRun, add
 298                          * the MaxRecvDataSegmentLength to read_data_done and
 299                          * to the sequence's next_burst_len;
 300                          *
 301                          * For DataPDUInOrder=No, while the first DataSN of the
 302                          * sequence is less than the received BegRun, find the
 303                          * struct iscsi_pdu of the DataSN in question and add the
 304                          * MaxRecvDataSegmentLength to read_data_done and to the
 305                          * sequence's next_burst_len;
 306                          */
 307                         if (conn->sess->sess_ops->DataPDUInOrder) {
 308                                 while (data_sn < begrun) {
 309                                         seq->pdu_send_order++;
 310                                         read_data_done +=
 311                                                 conn->conn_ops->MaxRecvDataSegmentLength;
 312                                         seq->next_burst_len +=
 313                                                 conn->conn_ops->MaxRecvDataSegmentLength;
 314                                         data_sn++;
 315                                 }
 316                         } else {
 317                                 int j;
 318                                 struct iscsi_pdu *pdu;
 319
 320                                 while (data_sn < begrun) {
 321                                         seq->pdu_send_order++;
 322
 323                                         for (j = 0; j < seq->pdu_count; j++) {
 324                                                 pdu = &cmd->pdu_list[
 325                                                         seq->pdu_start + j];
 326                                                 if (pdu->data_sn == data_sn) {
 327                                                         read_data_done +=
 328                                                                 pdu->length;
 329                                                         seq->next_burst_len +=
 330                                                                 pdu->length;
 331                                                 }
 332                                         }
 333                                         data_sn++;
 334                                 }
 335                         }
 336                         continue;
 337                 }
 338
 339                 /*
 340                  * This DataIN sequence is larger than the received BegRun,
 341                  * reset seq->pdu_send_order and continue.
 342                  */
 343                 if ((seq->first_datasn > begrun) ||
 344                                 (seq->last_datasn > begrun)) {
 345                         pr_err("Post BegRun sequence 0x%08x -> 0x%08x\n",
 346                                         seq->first_datasn, seq->last_datasn);
 347
 348                         seq->next_burst_len = seq->pdu_send_order = 0;
 349                         continue;
 350                 }
 351         }
 352
 353         if (!found_seq) {
 354                 if (!begrun) {
 355                         if (!first_seq) {
 356                                 pr_err("ITT: 0x%08x, Begrun: 0x%08x"
 357                                         " but first_seq is NULL\n",
 358                                         cmd->init_task_tag, begrun);
 359                                 return -1;
 360                         }
 361                         seq_send_order = first_seq->seq_send_order;
 362                         seq->next_burst_len = seq->pdu_send_order = 0;
 363                         goto done;
 364                 }
 365
 366                 pr_err("Unable to locate struct iscsi_seq for ITT: 0x%08x,"
 367                         " BegRun: 0x%08x, RunLength: 0x%08x while"
 368                         " DataSequenceInOrder=No and DataPDUInOrder=%s.\n",
 369                                 cmd->init_task_tag, begrun, runlength,
 370                         (conn->sess->sess_ops->DataPDUInOrder) ? "Yes" : "No");
 371                 return -1;
 372         }
 373
 374 done:
 375         dr->read_data_done = read_data_done;
 376         dr->seq_send_order = seq_send_order;
 377
 378         return 0;
 379 }
 380
 381 static int iscsit_handle_recovery_datain(
 382         struct iscsi_cmd *cmd,
 383         unsigned char *buf,
 384         u32 begrun,
 385         u32 runlength)
 386 {
 387         struct iscsi_conn *conn = cmd->conn;
 388         struct iscsi_datain_req *dr;
 389         struct se_cmd *se_cmd = &cmd->se_cmd;
 390
 391         if (!(se_cmd->transport_state & CMD_T_COMPLETE)) {
 392                 pr_err("Ignoring ITT: 0x%08x Data SNACK\n",
 393                                 cmd->init_task_tag);
 394                 return 0;
 395         }
 396
 397         /*
 398          * Make sure the initiator is not requesting retransmission
 399          * of DataSNs already acknowledged by a Data ACK SNACK.
 400          */
 401         if ((cmd->cmd_flags & ICF_GOT_DATACK_SNACK) &&
 402             (begrun <= cmd->acked_data_sn)) {
 403                 pr_err("ITT: 0x%08x, Data SNACK requesting"
 404                         " retransmission of DataSN: 0x%08x to 0x%08x but"
 405                         " already acked to DataSN: 0x%08x by Data ACK SNACK,"
 406                         " protocol error.\n", cmd->init_task_tag, begrun,
 407                         (begrun + runlength), cmd->acked_data_sn);
 408
 409                 return iscsit_reject_cmd(cmd, ISCSI_REASON_PROTOCOL_ERROR, buf);
 410         }
 411
 412         /*
 413          * Make sure BegRun and RunLength in the Data SNACK are sane.
 414          * Note: (cmd->data_sn - 1) will carry the maximum DataSN sent.
 415          */
 416         if ((begrun + runlength) > (cmd->data_sn - 1)) {
 417                 pr_err("Initiator requesting BegRun: 0x%08x, RunLength"
 418                         ": 0x%08x greater than maximum DataSN: 0x%08x.\n",
 419                                 begrun, runlength, (cmd->data_sn - 1));
 420                 return iscsit_reject_cmd(cmd, ISCSI_REASON_BOOKMARK_INVALID,
 421                                          buf);
 422         }
 423
 424         dr = iscsit_allocate_datain_req();
 425         if (!dr)
 426                 return iscsit_reject_cmd(cmd, ISCSI_REASON_BOOKMARK_NO_RESOURCES,
 427                                          buf);
 428
 429         dr->data_sn = dr->begrun = begrun;
 430         dr->runlength = runlength;
 431         dr->generate_recovery_values = 1;
 432         dr->recovery = DATAIN_WITHIN_COMMAND_RECOVERY;
 433
 434         iscsit_attach_datain_req(cmd, dr);
 435
 436         cmd->i_state = ISTATE_SEND_DATAIN;
 437         iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
 438
 439         return 0;
 440 }
 441
 442 int iscsit_handle_recovery_datain_or_r2t(
 443         struct iscsi_conn *conn,
 444         unsigned char *buf,
 445         itt_t init_task_tag,
 446         u32 targ_xfer_tag,
 447         u32 begrun,
 448         u32 runlength)
 449 {
 450         struct iscsi_cmd *cmd;
 451
 452         cmd = iscsit_find_cmd_from_itt(conn, init_task_tag);
 453         if (!cmd)
 454                 return 0;
 455
 456         /*
 457          * FIXME: This will not work for bidi commands.
 458          */
 459         switch (cmd->data_direction) {
 460         case DMA_TO_DEVICE:
 461                 return iscsit_handle_r2t_snack(cmd, buf, begrun, runlength);
 462         case DMA_FROM_DEVICE:
 463                 return iscsit_handle_recovery_datain(cmd, buf, begrun,
 464                                 runlength);
 465         default:
 466                 pr_err("Unknown cmd->data_direction: 0x%02x\n",
 467                                 cmd->data_direction);
 468                 return -1;
 469         }
 470
 471         return 0;
 472 }
 473
 474 /* #warning FIXME: Status SNACK needs to be dependent on OPCODE!!! */
 475 int iscsit_handle_status_snack(
 476         struct iscsi_conn *conn,
 477         itt_t init_task_tag,
 478         u32 targ_xfer_tag,
 479         u32 begrun,
 480         u32 runlength)
 481 {
 482         struct iscsi_cmd *cmd = NULL;
 483         u32 last_statsn;
 484         int found_cmd;
 485
 486         if (!begrun) {
 487                 begrun = conn->exp_statsn;
 488         } else if (conn->exp_statsn > begrun) {
 489                 pr_err("Got Status SNACK Begrun: 0x%08x, RunLength:"
 490                         " 0x%08x but already got ExpStatSN: 0x%08x on CID:"
 491                         " %hu.\n", begrun, runlength, conn->exp_statsn,
 492                         conn->cid);
 493                 return 0;
 494         }
 495
 496         last_statsn = (!runlength) ? conn->stat_sn : (begrun + runlength);
 497
 498         while (begrun < last_statsn) {
 499                 found_cmd = 0;
 500
 501                 spin_lock_bh(&conn->cmd_lock);
 502                 list_for_each_entry(cmd, &conn->conn_cmd_list, i_conn_node) {
 503                         if (cmd->stat_sn == begrun) {
 504                                 found_cmd = 1;
 505                                 break;
 506                         }
 507                 }
 508                 spin_unlock_bh(&conn->cmd_lock);
 509
 510                 if (!found_cmd) {
 511                         pr_err("Unable to find StatSN: 0x%08x for"
 512                                 " a Status SNACK, assuming this was a"
 513                                 " protactic SNACK for an untransmitted"
 514                                 " StatSN, ignoring.\n", begrun);
 515                         begrun++;
 516                         continue;
 517                 }
 518
 519                 spin_lock_bh(&cmd->istate_lock);
 520                 if (cmd->i_state == ISTATE_SEND_DATAIN) {
 521                         spin_unlock_bh(&cmd->istate_lock);
 522                         pr_err("Ignoring Status SNACK for BegRun:"
 523                                 " 0x%08x, RunLength: 0x%08x, assuming this was"
 524                                 " a protactic SNACK for an untransmitted"
 525                                 " StatSN\n", begrun, runlength);
 526                         begrun++;
 527                         continue;
 528                 }
 529                 spin_unlock_bh(&cmd->istate_lock);
 530
 531                 cmd->i_state = ISTATE_SEND_STATUS_RECOVERY;
 532                 iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
 533                 begrun++;
 534         }
 535
 536         return 0;
 537 }
 538
 539 int iscsit_handle_data_ack(
 540         struct iscsi_conn *conn,
 541         u32 targ_xfer_tag,
 542         u32 begrun,
 543         u32 runlength)
 544 {
 545         struct iscsi_cmd *cmd = NULL;
 546
 547         cmd = iscsit_find_cmd_from_ttt(conn, targ_xfer_tag);
 548         if (!cmd) {
 549                 pr_err("Data ACK SNACK for TTT: 0x%08x is"
 550                         " invalid.\n", targ_xfer_tag);
 551                 return -1;
 552         }
 553
 554         if (begrun <= cmd->acked_data_sn) {
 555                 pr_err("ITT: 0x%08x Data ACK SNACK BegRUN: 0x%08x is"
 556                         " less than the already acked DataSN: 0x%08x.\n",
 557                         cmd->init_task_tag, begrun, cmd->acked_data_sn);
 558                 return -1;
 559         }
 560
 561         /*
 562          * For Data ACK SNACK, BegRun is the next expected DataSN.
 563          * (see iSCSI v19: 10.16.6)
 564          */
 565         cmd->cmd_flags |= ICF_GOT_DATACK_SNACK;
 566         cmd->acked_data_sn = (begrun - 1);
 567
 568         pr_debug("Received Data ACK SNACK for ITT: 0x%08x,"
 569                 " updated acked DataSN to 0x%08x.\n",
 570                         cmd->init_task_tag, cmd->acked_data_sn);
 571
 572         return 0;
 573 }
 574
 575 static int iscsit_send_recovery_r2t(
 576         struct iscsi_cmd *cmd,
 577         u32 offset,
 578         u32 xfer_len)
 579 {
 580         int ret;
 581
 582         spin_lock_bh(&cmd->r2t_lock);
 583         ret = iscsit_add_r2t_to_list(cmd, offset, xfer_len, 1, 0);
 584         spin_unlock_bh(&cmd->r2t_lock);
 585
 586         return ret;
 587 }
 588
 589 int iscsit_dataout_datapduinorder_no_fbit(
 590         struct iscsi_cmd *cmd,
 591         struct iscsi_pdu *pdu)
 592 {
 593         int i, send_recovery_r2t = 0, recovery = 0;
 594         u32 length = 0, offset = 0, pdu_count = 0, xfer_len = 0;
 595         struct iscsi_conn *conn = cmd->conn;
 596         struct iscsi_pdu *first_pdu = NULL;
 597
 598         /*
 599          * Get an struct iscsi_pdu pointer to the first PDU, and total PDU count
 600          * of the DataOUT sequence.
 601          */
 602         if (conn->sess->sess_ops->DataSequenceInOrder) {
 603                 for (i = 0; i < cmd->pdu_count; i++) {
 604                         if (cmd->pdu_list[i].seq_no == pdu->seq_no) {
 605                                 if (!first_pdu)
 606                                         first_pdu = &cmd->pdu_list[i];
 607                                 xfer_len += cmd->pdu_list[i].length;
 608                                 pdu_count++;
 609                         } else if (pdu_count)
 610                                 break;
 611                 }
 612         } else {
 613                 struct iscsi_seq *seq = cmd->seq_ptr;
 614
 615                 first_pdu = &cmd->pdu_list[seq->pdu_start];
 616                 pdu_count = seq->pdu_count;
 617         }
 618
 619         if (!first_pdu || !pdu_count)
 620                 return DATAOUT_CANNOT_RECOVER;
 621
 622         /*
 623          * Loop through the ending DataOUT Sequence checking each struct iscsi_pdu.
 624          * The following ugly logic does batching of not received PDUs.
 625          */
 626         for (i = 0; i < pdu_count; i++) {
 627                 if (first_pdu[i].status == ISCSI_PDU_RECEIVED_OK) {
 628                         if (!send_recovery_r2t)
 629                                 continue;
 630
 631                         if (iscsit_send_recovery_r2t(cmd, offset, length) < 0)
 632                                 return DATAOUT_CANNOT_RECOVER;
 633
 634                         send_recovery_r2t = length = offset = 0;
 635                         continue;
 636                 }
 637                 /*
 638                  * Set recovery = 1 for any missing, CRC failed, or timed
 639                  * out PDUs to let the DataOUT logic know that this sequence
 640                  * has not been completed yet.
 641                  *
 642                  * Also, only send a Recovery R2T for ISCSI_PDU_NOT_RECEIVED.
 643                  * We assume if the PDU either failed CRC or timed out
 644                  * that a Recovery R2T has already been sent.
 645                  */
 646                 recovery = 1;
 647
 648                 if (first_pdu[i].status != ISCSI_PDU_NOT_RECEIVED)
 649                         continue;
 650
 651                 if (!offset)
 652                         offset = first_pdu[i].offset;
 653                 length += first_pdu[i].length;
 654
 655                 send_recovery_r2t = 1;
 656         }
 657
 658         if (send_recovery_r2t)
 659                 if (iscsit_send_recovery_r2t(cmd, offset, length) < 0)
 660                         return DATAOUT_CANNOT_RECOVER;
 661
 662         return (!recovery) ? DATAOUT_NORMAL : DATAOUT_WITHIN_COMMAND_RECOVERY;
 663 }
 664
 665 static int iscsit_recalculate_dataout_values(
 666         struct iscsi_cmd *cmd,
 667         u32 pdu_offset,
 668         u32 pdu_length,
 669         u32 *r2t_offset,
 670         u32 *r2t_length)
 671 {
 672         int i;
 673         struct iscsi_conn *conn = cmd->conn;
 674         struct iscsi_pdu *pdu = NULL;
 675
 676         if (conn->sess->sess_ops->DataSequenceInOrder) {
 677                 cmd->data_sn = 0;
 678
 679                 if (conn->sess->sess_ops->DataPDUInOrder) {
 680                         *r2t_offset = cmd->write_data_done;
 681                         *r2t_length = (cmd->seq_end_offset -
 682                                         cmd->write_data_done);
 683                         return 0;
 684                 }
 685
 686                 *r2t_offset = cmd->seq_start_offset;
 687                 *r2t_length = (cmd->seq_end_offset - cmd->seq_start_offset);
 688
 689                 for (i = 0; i < cmd->pdu_count; i++) {
 690                         pdu = &cmd->pdu_list[i];
 691
 692                         if (pdu->status != ISCSI_PDU_RECEIVED_OK)
 693                                 continue;
 694
 695                         if ((pdu->offset >= cmd->seq_start_offset) &&
 696                            ((pdu->offset + pdu->length) <=
 697                              cmd->seq_end_offset)) {
 698                                 if (!cmd->unsolicited_data)
 699                                         cmd->next_burst_len -= pdu->length;
 700                                 else
 701                                         cmd->first_burst_len -= pdu->length;
 702
 703                                 cmd->write_data_done -= pdu->length;
 704                                 pdu->status = ISCSI_PDU_NOT_RECEIVED;
 705                         }
 706                 }
 707         } else {
 708                 struct iscsi_seq *seq = NULL;
 709
 710                 seq = iscsit_get_seq_holder(cmd, pdu_offset, pdu_length);
 711                 if (!seq)
 712                         return -1;
 713
 714                 *r2t_offset = seq->orig_offset;
 715                 *r2t_length = seq->xfer_len;
 716
 717                 cmd->write_data_done -= (seq->offset - seq->orig_offset);
 718                 if (cmd->immediate_data)
 719                         cmd->first_burst_len = cmd->write_data_done;
 720
 721                 seq->data_sn = 0;
 722                 seq->offset = seq->orig_offset;
 723                 seq->next_burst_len = 0;
 724                 seq->status = DATAOUT_SEQUENCE_WITHIN_COMMAND_RECOVERY;
 725
 726                 if (conn->sess->sess_ops->DataPDUInOrder)
 727                         return 0;
 728
 729                 for (i = 0; i < seq->pdu_count; i++) {
 730                         pdu = &cmd->pdu_list[i+seq->pdu_start];
 731
 732                         if (pdu->status != ISCSI_PDU_RECEIVED_OK)
 733                                 continue;
 734
 735                         pdu->status = ISCSI_PDU_NOT_RECEIVED;
 736                 }
 737         }
 738
 739         return 0;
 740 }
 741
 742 int iscsit_recover_dataout_sequence(
 743         struct iscsi_cmd *cmd,
 744         u32 pdu_offset,
 745         u32 pdu_length)
 746 {
 747         u32 r2t_length = 0, r2t_offset = 0;
 748
 749         spin_lock_bh(&cmd->istate_lock);
 750         cmd->cmd_flags |= ICF_WITHIN_COMMAND_RECOVERY;
 751         spin_unlock_bh(&cmd->istate_lock);
 752
 753         if (iscsit_recalculate_dataout_values(cmd, pdu_offset, pdu_length,
 754                         &r2t_offset, &r2t_length) < 0)
 755                 return DATAOUT_CANNOT_RECOVER;
 756
 757         iscsit_send_recovery_r2t(cmd, r2t_offset, r2t_length);
 758
 759         return DATAOUT_WITHIN_COMMAND_RECOVERY;
 760 }
 761
 762 static struct iscsi_ooo_cmdsn *iscsit_allocate_ooo_cmdsn(void)
 763 {
 764         struct iscsi_ooo_cmdsn *ooo_cmdsn = NULL;
 765
 766         ooo_cmdsn = kmem_cache_zalloc(lio_ooo_cache, GFP_ATOMIC);
 767         if (!ooo_cmdsn) {
 768                 pr_err("Unable to allocate memory for"
 769                         " struct iscsi_ooo_cmdsn.\n");
 770                 return NULL;
 771         }
 772         INIT_LIST_HEAD(&ooo_cmdsn->ooo_list);
 773
 774         return ooo_cmdsn;
 775 }
 776
 777 static int iscsit_attach_ooo_cmdsn(
 778         struct iscsi_session *sess,
 779         struct iscsi_ooo_cmdsn *ooo_cmdsn)
 780 {
 781         struct iscsi_ooo_cmdsn *ooo_tail, *ooo_tmp;
 782
 783         lockdep_assert_held(&sess->cmdsn_mutex);
 784
 785         /*
 786          * We attach the struct iscsi_ooo_cmdsn entry to the out of order
 787          * list in increasing CmdSN order.
 788          * This allows iscsi_execute_ooo_cmdsns() to detect any
 789          * additional CmdSN holes while performing delayed execution.
 790          */
 791         if (list_empty(&sess->sess_ooo_cmdsn_list))
 792                 list_add_tail(&ooo_cmdsn->ooo_list,
 793                                 &sess->sess_ooo_cmdsn_list);
 794         else {
 795                 ooo_tail = list_entry(sess->sess_ooo_cmdsn_list.prev,
 796                                 typeof(*ooo_tail), ooo_list);
 797                 /*
 798                  * CmdSN is greater than the tail of the list.
 799                  */
 800                 if (iscsi_sna_lt(ooo_tail->cmdsn, ooo_cmdsn->cmdsn))
 801                         list_add_tail(&ooo_cmdsn->ooo_list,
 802                                         &sess->sess_ooo_cmdsn_list);
 803                 else {
 804                         /*
 805                          * CmdSN is either lower than the head,  or somewhere
 806                          * in the middle.
 807                          */
 808                         list_for_each_entry(ooo_tmp, &sess->sess_ooo_cmdsn_list,
 809                                                 ooo_list) {
 810                                 if (iscsi_sna_lt(ooo_tmp->cmdsn, ooo_cmdsn->cmdsn))
 811                                         continue;
 812
 813                                 /* Insert before this entry */
 814                                 list_add(&ooo_cmdsn->ooo_list,
 815                                         ooo_tmp->ooo_list.prev);
 816                                 break;
 817                         }
 818                 }
 819         }
 820
 821         return 0;
 822 }
 823
 824 /*
 825  *      Removes an struct iscsi_ooo_cmdsn from a session's list,
 826  *      called with struct iscsi_session->cmdsn_mutex held.
 827  */
 828 void iscsit_remove_ooo_cmdsn(
 829         struct iscsi_session *sess,
 830         struct iscsi_ooo_cmdsn *ooo_cmdsn)
 831 {
 832         list_del(&ooo_cmdsn->ooo_list);
 833         kmem_cache_free(lio_ooo_cache, ooo_cmdsn);
 834 }
 835
 836 void iscsit_clear_ooo_cmdsns_for_conn(struct iscsi_conn *conn)
 837 {
 838         struct iscsi_ooo_cmdsn *ooo_cmdsn;
 839         struct iscsi_session *sess = conn->sess;
 840
 841         mutex_lock(&sess->cmdsn_mutex);
 842         list_for_each_entry(ooo_cmdsn, &sess->sess_ooo_cmdsn_list, ooo_list) {
 843                 if (ooo_cmdsn->cid != conn->cid)
 844                         continue;
 845
 846                 ooo_cmdsn->cmd = NULL;
 847         }
 848         mutex_unlock(&sess->cmdsn_mutex);
 849 }
 850
 851 int iscsit_execute_ooo_cmdsns(struct iscsi_session *sess)
 852 {
 853         int ooo_count = 0;
 854         struct iscsi_cmd *cmd = NULL;
 855         struct iscsi_ooo_cmdsn *ooo_cmdsn, *ooo_cmdsn_tmp;
 856
 857         lockdep_assert_held(&sess->cmdsn_mutex);
 858
 859         list_for_each_entry_safe(ooo_cmdsn, ooo_cmdsn_tmp,
 860                                 &sess->sess_ooo_cmdsn_list, ooo_list) {
 861                 if (ooo_cmdsn->cmdsn != sess->exp_cmd_sn)
 862                         continue;
 863
 864                 if (!ooo_cmdsn->cmd) {
 865                         sess->exp_cmd_sn++;
 866                         iscsit_remove_ooo_cmdsn(sess, ooo_cmdsn);
 867                         continue;
 868                 }
 869
 870                 cmd = ooo_cmdsn->cmd;
 871                 cmd->i_state = cmd->deferred_i_state;
 872                 ooo_count++;
 873                 sess->exp_cmd_sn++;
 874                 pr_debug("Executing out of order CmdSN: 0x%08x,"
 875                         " incremented ExpCmdSN to 0x%08x.\n",
 876                         cmd->cmd_sn, sess->exp_cmd_sn);
 877
 878                 iscsit_remove_ooo_cmdsn(sess, ooo_cmdsn);
 879
 880                 if (iscsit_execute_cmd(cmd, 1) < 0)
 881                         return -1;
 882
 883                 continue;
 884         }
 885
 886         return ooo_count;
 887 }
 888
 889 /*
 890  *      Called either:
 891  *
 892  *      1. With sess->cmdsn_mutex held from iscsi_execute_ooo_cmdsns()
 893  *      or iscsi_check_received_cmdsn().
 894  *      2. With no locks held directly from iscsi_handle_XXX_pdu() functions
 895  *      for immediate commands.
 896  */
 897 int iscsit_execute_cmd(struct iscsi_cmd *cmd, int ooo)
 898 {
 899         struct se_cmd *se_cmd = &cmd->se_cmd;
 900         struct iscsi_conn *conn = cmd->conn;
 901         int lr = 0;
 902
 903         spin_lock_bh(&cmd->istate_lock);
 904         if (ooo)
 905                 cmd->cmd_flags &= ~ICF_OOO_CMDSN;
 906
 907         switch (cmd->iscsi_opcode) {
 908         case ISCSI_OP_SCSI_CMD:
 909                 /*
 910                  * Go ahead and send the CHECK_CONDITION status for
 911                  * any SCSI CDB exceptions that may have occurred.
 912                  */
 913                 if (cmd->sense_reason) {
 914                         if (cmd->sense_reason == TCM_RESERVATION_CONFLICT) {
 915                                 cmd->i_state = ISTATE_SEND_STATUS;
 916                                 spin_unlock_bh(&cmd->istate_lock);
 917                                 iscsit_add_cmd_to_response_queue(cmd, cmd->conn,
 918                                                 cmd->i_state);
 919                                 return 0;
 920                         }
 921                         spin_unlock_bh(&cmd->istate_lock);
 922                         if (cmd->se_cmd.transport_state & CMD_T_ABORTED)
 923                                 return 0;
 924                         return transport_send_check_condition_and_sense(se_cmd,
 925                                         cmd->sense_reason, 0);
 926                 }
 927                 /*
 928                  * Special case for delayed CmdSN with Immediate
 929                  * Data and/or Unsolicited Data Out attached.
 930                  */
 931                 if (cmd->immediate_data) {
 932                         if (cmd->cmd_flags & ICF_GOT_LAST_DATAOUT) {
 933                                 spin_unlock_bh(&cmd->istate_lock);
 934                                 target_execute_cmd(&cmd->se_cmd);
 935                                 return 0;
 936                         }
 937                         spin_unlock_bh(&cmd->istate_lock);
 938
 939                         if (!(cmd->cmd_flags &
 940                                         ICF_NON_IMMEDIATE_UNSOLICITED_DATA)) {
 941                                 if (cmd->se_cmd.transport_state & CMD_T_ABORTED)
 942                                         return 0;
 943
 944                                 iscsit_set_dataout_sequence_values(cmd);
 945                                 conn->conn_transport->iscsit_get_dataout(conn, cmd, false);
 946                         }
 947                         return 0;
 948                 }
 949                 /*
 950                  * The default handler.
 951                  */
 952                 spin_unlock_bh(&cmd->istate_lock);
 953
 954                 if ((cmd->data_direction == DMA_TO_DEVICE) &&
 955                     !(cmd->cmd_flags & ICF_NON_IMMEDIATE_UNSOLICITED_DATA)) {
 956                         if (cmd->se_cmd.transport_state & CMD_T_ABORTED)
 957                                 return 0;
 958
 959                         iscsit_set_unsolicited_dataout(cmd);
 960                 }
 961                 return transport_handle_cdb_direct(&cmd->se_cmd);
 962
 963         case ISCSI_OP_NOOP_OUT:
 964         case ISCSI_OP_TEXT:
 965                 spin_unlock_bh(&cmd->istate_lock);
 966                 iscsit_add_cmd_to_response_queue(cmd, cmd->conn, cmd->i_state);
 967                 break;
 968         case ISCSI_OP_SCSI_TMFUNC:
 969                 if (cmd->se_cmd.se_tmr_req->response) {
 970                         spin_unlock_bh(&cmd->istate_lock);
 971                         iscsit_add_cmd_to_response_queue(cmd, cmd->conn,
 972                                         cmd->i_state);
 973                         return 0;
 974                 }
 975                 spin_unlock_bh(&cmd->istate_lock);
 976
 977                 return transport_generic_handle_tmr(&cmd->se_cmd);
 978         case ISCSI_OP_LOGOUT:
 979                 spin_unlock_bh(&cmd->istate_lock);
 980                 switch (cmd->logout_reason) {
 981                 case ISCSI_LOGOUT_REASON_CLOSE_SESSION:
 982                         lr = iscsit_logout_closesession(cmd, cmd->conn);
 983                         break;
 984                 case ISCSI_LOGOUT_REASON_CLOSE_CONNECTION:
 985                         lr = iscsit_logout_closeconnection(cmd, cmd->conn);
 986                         break;
 987                 case ISCSI_LOGOUT_REASON_RECOVERY:
 988                         lr = iscsit_logout_removeconnforrecovery(cmd, cmd->conn);
 989                         break;
 990                 default:
 991                         pr_err("Unknown iSCSI Logout Request Code:"
 992                                 " 0x%02x\n", cmd->logout_reason);
 993                         return -1;
 994                 }
 995
 996                 return lr;
 997         default:
 998                 spin_unlock_bh(&cmd->istate_lock);
 999                 pr_err("Cannot perform out of order execution for"
1000                 " unknown iSCSI Opcode: 0x%02x\n", cmd->iscsi_opcode);
1001                 return -1;
1002         }
1003
1004         return 0;
1005 }
1006
1007 void iscsit_free_all_ooo_cmdsns(struct iscsi_session *sess)
1008 {
1009         struct iscsi_ooo_cmdsn *ooo_cmdsn, *ooo_cmdsn_tmp;
1010
1011         mutex_lock(&sess->cmdsn_mutex);
1012         list_for_each_entry_safe(ooo_cmdsn, ooo_cmdsn_tmp,
1013                         &sess->sess_ooo_cmdsn_list, ooo_list) {
1014
1015                 list_del(&ooo_cmdsn->ooo_list);
1016                 kmem_cache_free(lio_ooo_cache, ooo_cmdsn);
1017         }
1018         mutex_unlock(&sess->cmdsn_mutex);
1019 }
1020
1021 int iscsit_handle_ooo_cmdsn(
1022         struct iscsi_session *sess,
1023         struct iscsi_cmd *cmd,
1024         u32 cmdsn)
1025 {
1026         int batch = 0;
1027         struct iscsi_ooo_cmdsn *ooo_cmdsn = NULL, *ooo_tail = NULL;
1028
1029         cmd->deferred_i_state           = cmd->i_state;
1030         cmd->i_state                    = ISTATE_DEFERRED_CMD;
1031         cmd->cmd_flags                  |= ICF_OOO_CMDSN;
1032
1033         if (list_empty(&sess->sess_ooo_cmdsn_list))
1034                 batch = 1;
1035         else {
1036                 ooo_tail = list_entry(sess->sess_ooo_cmdsn_list.prev,
1037                                 typeof(*ooo_tail), ooo_list);
1038                 if (ooo_tail->cmdsn != (cmdsn - 1))
1039                         batch = 1;
1040         }
1041
1042         ooo_cmdsn = iscsit_allocate_ooo_cmdsn();
1043         if (!ooo_cmdsn)
1044                 return -ENOMEM;
1045
1046         ooo_cmdsn->cmd                  = cmd;
1047         ooo_cmdsn->batch_count          = (batch) ?
1048                                           (cmdsn - sess->exp_cmd_sn) : 1;
1049         ooo_cmdsn->cid                  = cmd->conn->cid;
1050         ooo_cmdsn->exp_cmdsn            = sess->exp_cmd_sn;
1051         ooo_cmdsn->cmdsn                = cmdsn;
1052
1053         if (iscsit_attach_ooo_cmdsn(sess, ooo_cmdsn) < 0) {
1054                 kmem_cache_free(lio_ooo_cache, ooo_cmdsn);
1055                 return -ENOMEM;
1056         }
1057
1058         return 0;
1059 }
1060
1061 static int iscsit_set_dataout_timeout_values(
1062         struct iscsi_cmd *cmd,
1063         u32 *offset,
1064         u32 *length)
1065 {
1066         struct iscsi_conn *conn = cmd->conn;
1067         struct iscsi_r2t *r2t;
1068
1069         if (cmd->unsolicited_data) {
1070                 *offset = 0;
1071                 *length = (conn->sess->sess_ops->FirstBurstLength >
1072                            cmd->se_cmd.data_length) ?
1073                            cmd->se_cmd.data_length :
1074                            conn->sess->sess_ops->FirstBurstLength;
1075                 return 0;
1076         }
1077
1078         spin_lock_bh(&cmd->r2t_lock);
1079         if (list_empty(&cmd->cmd_r2t_list)) {
1080                 pr_err("cmd->cmd_r2t_list is empty!\n");
1081                 spin_unlock_bh(&cmd->r2t_lock);
1082                 return -1;
1083         }
1084
1085         list_for_each_entry(r2t, &cmd->cmd_r2t_list, r2t_list) {
1086                 if (r2t->sent_r2t && !r2t->recovery_r2t && !r2t->seq_complete) {
1087                         *offset = r2t->offset;
1088                         *length = r2t->xfer_len;
1089                         spin_unlock_bh(&cmd->r2t_lock);
1090                         return 0;
1091                 }
1092         }
1093         spin_unlock_bh(&cmd->r2t_lock);
1094
1095         pr_err("Unable to locate any incomplete DataOUT"
1096                 " sequences for ITT: 0x%08x.\n", cmd->init_task_tag);
1097
1098         return -1;
1099 }
1100
1101 /*
1102  *      NOTE: Called from interrupt (timer) context.
1103  */
1104 void iscsit_handle_dataout_timeout(struct timer_list *t)
1105 {
1106         u32 pdu_length = 0, pdu_offset = 0;
1107         u32 r2t_length = 0, r2t_offset = 0;
1108         struct iscsi_cmd *cmd = from_timer(cmd, t, dataout_timer);
1109         struct iscsi_conn *conn = cmd->conn;
1110         struct iscsi_session *sess = NULL;
1111         struct iscsi_node_attrib *na;
1112
1113         iscsit_inc_conn_usage_count(conn);
1114
1115         spin_lock_bh(&cmd->dataout_timeout_lock);
1116         if (cmd->dataout_timer_flags & ISCSI_TF_STOP) {
1117                 spin_unlock_bh(&cmd->dataout_timeout_lock);
1118                 iscsit_dec_conn_usage_count(conn);
1119                 return;
1120         }
1121         cmd->dataout_timer_flags &= ~ISCSI_TF_RUNNING;
1122         sess = conn->sess;
1123         na = iscsit_tpg_get_node_attrib(sess);
1124
1125         if (!sess->sess_ops->ErrorRecoveryLevel) {
1126                 pr_err("Unable to recover from DataOut timeout while"
1127                         " in ERL=0, closing iSCSI connection for I_T Nexus"
1128                         " %s,i,0x%6phN,%s,t,0x%02x\n",
1129                         sess->sess_ops->InitiatorName, sess->isid,
1130                         sess->tpg->tpg_tiqn->tiqn, (u32)sess->tpg->tpgt);
1131                 goto failure;
1132         }
1133
1134         if (++cmd->dataout_timeout_retries == na->dataout_timeout_retries) {
1135                 pr_err("Command ITT: 0x%08x exceeded max retries"
1136                         " for DataOUT timeout %u, closing iSCSI connection for"
1137                         " I_T Nexus %s,i,0x%6phN,%s,t,0x%02x\n",
1138                         cmd->init_task_tag, na->dataout_timeout_retries,
1139                         sess->sess_ops->InitiatorName, sess->isid,
1140                         sess->tpg->tpg_tiqn->tiqn, (u32)sess->tpg->tpgt);
1141                 goto failure;
1142         }
1143
1144         cmd->cmd_flags |= ICF_WITHIN_COMMAND_RECOVERY;
1145
1146         if (conn->sess->sess_ops->DataSequenceInOrder) {
1147                 if (conn->sess->sess_ops->DataPDUInOrder) {
1148                         pdu_offset = cmd->write_data_done;
1149                         if ((pdu_offset + (conn->sess->sess_ops->MaxBurstLength -
1150                              cmd->next_burst_len)) > cmd->se_cmd.data_length)
1151                                 pdu_length = (cmd->se_cmd.data_length -
1152                                         cmd->write_data_done);
1153                         else
1154                                 pdu_length = (conn->sess->sess_ops->MaxBurstLength -
1155                                                 cmd->next_burst_len);
1156                 } else {
1157                         pdu_offset = cmd->seq_start_offset;
1158                         pdu_length = (cmd->seq_end_offset -
1159                                 cmd->seq_start_offset);
1160                 }
1161         } else {
1162                 if (iscsit_set_dataout_timeout_values(cmd, &pdu_offset,
1163                                 &pdu_length) < 0)
1164                         goto failure;
1165         }
1166
1167         if (iscsit_recalculate_dataout_values(cmd, pdu_offset, pdu_length,
1168                         &r2t_offset, &r2t_length) < 0)
1169                 goto failure;
1170
1171         pr_debug("Command ITT: 0x%08x timed out waiting for"
1172                 " completion of %sDataOUT Sequence Offset: %u, Length: %u\n",
1173                 cmd->init_task_tag, (cmd->unsolicited_data) ? "Unsolicited " :
1174                 "", r2t_offset, r2t_length);
1175
1176         if (iscsit_send_recovery_r2t(cmd, r2t_offset, r2t_length) < 0)
1177                 goto failure;
1178
1179         iscsit_start_dataout_timer(cmd, conn);
1180         spin_unlock_bh(&cmd->dataout_timeout_lock);
1181         iscsit_dec_conn_usage_count(conn);
1182
1183         return;
1184
1185 failure:
1186         spin_unlock_bh(&cmd->dataout_timeout_lock);
1187         iscsit_fill_cxn_timeout_err_stats(sess);
1188         iscsit_cause_connection_reinstatement(conn, 0);
1189         iscsit_dec_conn_usage_count(conn);
1190 }
1191
1192 void iscsit_mod_dataout_timer(struct iscsi_cmd *cmd)
1193 {
1194         struct iscsi_conn *conn = cmd->conn;
1195         struct iscsi_session *sess = conn->sess;
1196         struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
1197
1198         spin_lock_bh(&cmd->dataout_timeout_lock);
1199         if (!(cmd->dataout_timer_flags & ISCSI_TF_RUNNING)) {
1200                 spin_unlock_bh(&cmd->dataout_timeout_lock);
1201                 return;
1202         }
1203
1204         mod_timer(&cmd->dataout_timer,
1205                 (get_jiffies_64() + na->dataout_timeout * HZ));
1206         pr_debug("Updated DataOUT timer for ITT: 0x%08x",
1207                         cmd->init_task_tag);
1208         spin_unlock_bh(&cmd->dataout_timeout_lock);
1209 }
1210
1211 void iscsit_start_dataout_timer(
1212         struct iscsi_cmd *cmd,
1213         struct iscsi_conn *conn)
1214 {
1215         struct iscsi_session *sess = conn->sess;
1216         struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
1217
1218         lockdep_assert_held(&cmd->dataout_timeout_lock);
1219
1220         if (cmd->dataout_timer_flags & ISCSI_TF_RUNNING)
1221                 return;
1222
1223         pr_debug("Starting DataOUT timer for ITT: 0x%08x on"
1224                 " CID: %hu.\n", cmd->init_task_tag, conn->cid);
1225
1226         cmd->dataout_timer_flags &= ~ISCSI_TF_STOP;
1227         cmd->dataout_timer_flags |= ISCSI_TF_RUNNING;
1228         mod_timer(&cmd->dataout_timer, jiffies + na->dataout_timeout * HZ);
1229 }
1230
1231 void iscsit_stop_dataout_timer(struct iscsi_cmd *cmd)
1232 {
1233         spin_lock_bh(&cmd->dataout_timeout_lock);
1234         if (!(cmd->dataout_timer_flags & ISCSI_TF_RUNNING)) {
1235                 spin_unlock_bh(&cmd->dataout_timeout_lock);
1236                 return;
1237         }
1238         cmd->dataout_timer_flags |= ISCSI_TF_STOP;
1239         spin_unlock_bh(&cmd->dataout_timeout_lock);
1240
1241         del_timer_sync(&cmd->dataout_timer);
1242
1243         spin_lock_bh(&cmd->dataout_timeout_lock);
1244         cmd->dataout_timer_flags &= ~ISCSI_TF_RUNNING;
1245         pr_debug("Stopped DataOUT Timer for ITT: 0x%08x\n",
1246                         cmd->init_task_tag);
1247         spin_unlock_bh(&cmd->dataout_timeout_lock);
1248 }
1249 EXPORT_SYMBOL(iscsit_stop_dataout_timer);