linux/drivers/target/iscsi/iscsi_target_erl1.c
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   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 */
  45int 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
 112out:
 113        kfree(buf);
 114        return ret;
 115}
 116
 117/*
 118 *      Used for retransmitting R2Ts from a R2T SNACK request.
 119 */
 120static 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
 142static 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 */
 201int 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 */
 247int 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
 398done:
 399        dr->read_data_done = read_data_done;
 400        dr->seq_send_order = seq_send_order;
 401
 402        return 0;
 403}
 404
 405static 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
 466int 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!!! */
 499int 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 (!begrun) {
 511                begrun = conn->exp_statsn;
 512        } else if (conn->exp_statsn > begrun) {
 513                pr_err("Got Status SNACK Begrun: 0x%08x, RunLength:"
 514                        " 0x%08x but already got ExpStatSN: 0x%08x on CID:"
 515                        " %hu.\n", begrun, runlength, conn->exp_statsn,
 516                        conn->cid);
 517                return 0;
 518        }
 519
 520        last_statsn = (!runlength) ? conn->stat_sn : (begrun + runlength);
 521
 522        while (begrun < last_statsn) {
 523                found_cmd = 0;
 524
 525                spin_lock_bh(&conn->cmd_lock);
 526                list_for_each_entry(cmd, &conn->conn_cmd_list, i_conn_node) {
 527                        if (cmd->stat_sn == begrun) {
 528                                found_cmd = 1;
 529                                break;
 530                        }
 531                }
 532                spin_unlock_bh(&conn->cmd_lock);
 533
 534                if (!found_cmd) {
 535                        pr_err("Unable to find StatSN: 0x%08x for"
 536                                " a Status SNACK, assuming this was a"
 537                                " protactic SNACK for an untransmitted"
 538                                " StatSN, ignoring.\n", begrun);
 539                        begrun++;
 540                        continue;
 541                }
 542
 543                spin_lock_bh(&cmd->istate_lock);
 544                if (cmd->i_state == ISTATE_SEND_DATAIN) {
 545                        spin_unlock_bh(&cmd->istate_lock);
 546                        pr_err("Ignoring Status SNACK for BegRun:"
 547                                " 0x%08x, RunLength: 0x%08x, assuming this was"
 548                                " a protactic SNACK for an untransmitted"
 549                                " StatSN\n", begrun, runlength);
 550                        begrun++;
 551                        continue;
 552                }
 553                spin_unlock_bh(&cmd->istate_lock);
 554
 555                cmd->i_state = ISTATE_SEND_STATUS_RECOVERY;
 556                iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
 557                begrun++;
 558        }
 559
 560        return 0;
 561}
 562
 563int iscsit_handle_data_ack(
 564        struct iscsi_conn *conn,
 565        u32 targ_xfer_tag,
 566        u32 begrun,
 567        u32 runlength)
 568{
 569        struct iscsi_cmd *cmd = NULL;
 570
 571        cmd = iscsit_find_cmd_from_ttt(conn, targ_xfer_tag);
 572        if (!cmd) {
 573                pr_err("Data ACK SNACK for TTT: 0x%08x is"
 574                        " invalid.\n", targ_xfer_tag);
 575                return -1;
 576        }
 577
 578        if (begrun <= cmd->acked_data_sn) {
 579                pr_err("ITT: 0x%08x Data ACK SNACK BegRUN: 0x%08x is"
 580                        " less than the already acked DataSN: 0x%08x.\n",
 581                        cmd->init_task_tag, begrun, cmd->acked_data_sn);
 582                return -1;
 583        }
 584
 585        /*
 586         * For Data ACK SNACK, BegRun is the next expected DataSN.
 587         * (see iSCSI v19: 10.16.6)
 588         */
 589        cmd->cmd_flags |= ICF_GOT_DATACK_SNACK;
 590        cmd->acked_data_sn = (begrun - 1);
 591
 592        pr_debug("Received Data ACK SNACK for ITT: 0x%08x,"
 593                " updated acked DataSN to 0x%08x.\n",
 594                        cmd->init_task_tag, cmd->acked_data_sn);
 595
 596        return 0;
 597}
 598
 599static int iscsit_send_recovery_r2t(
 600        struct iscsi_cmd *cmd,
 601        u32 offset,
 602        u32 xfer_len)
 603{
 604        int ret;
 605
 606        spin_lock_bh(&cmd->r2t_lock);
 607        ret = iscsit_add_r2t_to_list(cmd, offset, xfer_len, 1, 0);
 608        spin_unlock_bh(&cmd->r2t_lock);
 609
 610        return ret;
 611}
 612
 613int iscsit_dataout_datapduinorder_no_fbit(
 614        struct iscsi_cmd *cmd,
 615        struct iscsi_pdu *pdu)
 616{
 617        int i, send_recovery_r2t = 0, recovery = 0;
 618        u32 length = 0, offset = 0, pdu_count = 0, xfer_len = 0;
 619        struct iscsi_conn *conn = cmd->conn;
 620        struct iscsi_pdu *first_pdu = NULL;
 621
 622        /*
 623         * Get an struct iscsi_pdu pointer to the first PDU, and total PDU count
 624         * of the DataOUT sequence.
 625         */
 626        if (conn->sess->sess_ops->DataSequenceInOrder) {
 627                for (i = 0; i < cmd->pdu_count; i++) {
 628                        if (cmd->pdu_list[i].seq_no == pdu->seq_no) {
 629                                if (!first_pdu)
 630                                        first_pdu = &cmd->pdu_list[i];
 631                                 xfer_len += cmd->pdu_list[i].length;
 632                                 pdu_count++;
 633                        } else if (pdu_count)
 634                                break;
 635                }
 636        } else {
 637                struct iscsi_seq *seq = cmd->seq_ptr;
 638
 639                first_pdu = &cmd->pdu_list[seq->pdu_start];
 640                pdu_count = seq->pdu_count;
 641        }
 642
 643        if (!first_pdu || !pdu_count)
 644                return DATAOUT_CANNOT_RECOVER;
 645
 646        /*
 647         * Loop through the ending DataOUT Sequence checking each struct iscsi_pdu.
 648         * The following ugly logic does batching of not received PDUs.
 649         */
 650        for (i = 0; i < pdu_count; i++) {
 651                if (first_pdu[i].status == ISCSI_PDU_RECEIVED_OK) {
 652                        if (!send_recovery_r2t)
 653                                continue;
 654
 655                        if (iscsit_send_recovery_r2t(cmd, offset, length) < 0)
 656                                return DATAOUT_CANNOT_RECOVER;
 657
 658                        send_recovery_r2t = length = offset = 0;
 659                        continue;
 660                }
 661                /*
 662                 * Set recovery = 1 for any missing, CRC failed, or timed
 663                 * out PDUs to let the DataOUT logic know that this sequence
 664                 * has not been completed yet.
 665                 *
 666                 * Also, only send a Recovery R2T for ISCSI_PDU_NOT_RECEIVED.
 667                 * We assume if the PDU either failed CRC or timed out
 668                 * that a Recovery R2T has already been sent.
 669                 */
 670                recovery = 1;
 671
 672                if (first_pdu[i].status != ISCSI_PDU_NOT_RECEIVED)
 673                        continue;
 674
 675                if (!offset)
 676                        offset = first_pdu[i].offset;
 677                length += first_pdu[i].length;
 678
 679                send_recovery_r2t = 1;
 680        }
 681
 682        if (send_recovery_r2t)
 683                if (iscsit_send_recovery_r2t(cmd, offset, length) < 0)
 684                        return DATAOUT_CANNOT_RECOVER;
 685
 686        return (!recovery) ? DATAOUT_NORMAL : DATAOUT_WITHIN_COMMAND_RECOVERY;
 687}
 688
 689static int iscsit_recalculate_dataout_values(
 690        struct iscsi_cmd *cmd,
 691        u32 pdu_offset,
 692        u32 pdu_length,
 693        u32 *r2t_offset,
 694        u32 *r2t_length)
 695{
 696        int i;
 697        struct iscsi_conn *conn = cmd->conn;
 698        struct iscsi_pdu *pdu = NULL;
 699
 700        if (conn->sess->sess_ops->DataSequenceInOrder) {
 701                cmd->data_sn = 0;
 702
 703                if (conn->sess->sess_ops->DataPDUInOrder) {
 704                        *r2t_offset = cmd->write_data_done;
 705                        *r2t_length = (cmd->seq_end_offset -
 706                                        cmd->write_data_done);
 707                        return 0;
 708                }
 709
 710                *r2t_offset = cmd->seq_start_offset;
 711                *r2t_length = (cmd->seq_end_offset - cmd->seq_start_offset);
 712
 713                for (i = 0; i < cmd->pdu_count; i++) {
 714                        pdu = &cmd->pdu_list[i];
 715
 716                        if (pdu->status != ISCSI_PDU_RECEIVED_OK)
 717                                continue;
 718
 719                        if ((pdu->offset >= cmd->seq_start_offset) &&
 720                           ((pdu->offset + pdu->length) <=
 721                             cmd->seq_end_offset)) {
 722                                if (!cmd->unsolicited_data)
 723                                        cmd->next_burst_len -= pdu->length;
 724                                else
 725                                        cmd->first_burst_len -= pdu->length;
 726
 727                                cmd->write_data_done -= pdu->length;
 728                                pdu->status = ISCSI_PDU_NOT_RECEIVED;
 729                        }
 730                }
 731        } else {
 732                struct iscsi_seq *seq = NULL;
 733
 734                seq = iscsit_get_seq_holder(cmd, pdu_offset, pdu_length);
 735                if (!seq)
 736                        return -1;
 737
 738                *r2t_offset = seq->orig_offset;
 739                *r2t_length = seq->xfer_len;
 740
 741                cmd->write_data_done -= (seq->offset - seq->orig_offset);
 742                if (cmd->immediate_data)
 743                        cmd->first_burst_len = cmd->write_data_done;
 744
 745                seq->data_sn = 0;
 746                seq->offset = seq->orig_offset;
 747                seq->next_burst_len = 0;
 748                seq->status = DATAOUT_SEQUENCE_WITHIN_COMMAND_RECOVERY;
 749
 750                if (conn->sess->sess_ops->DataPDUInOrder)
 751                        return 0;
 752
 753                for (i = 0; i < seq->pdu_count; i++) {
 754                        pdu = &cmd->pdu_list[i+seq->pdu_start];
 755
 756                        if (pdu->status != ISCSI_PDU_RECEIVED_OK)
 757                                continue;
 758
 759                        pdu->status = ISCSI_PDU_NOT_RECEIVED;
 760                }
 761        }
 762
 763        return 0;
 764}
 765
 766int iscsit_recover_dataout_sequence(
 767        struct iscsi_cmd *cmd,
 768        u32 pdu_offset,
 769        u32 pdu_length)
 770{
 771        u32 r2t_length = 0, r2t_offset = 0;
 772
 773        spin_lock_bh(&cmd->istate_lock);
 774        cmd->cmd_flags |= ICF_WITHIN_COMMAND_RECOVERY;
 775        spin_unlock_bh(&cmd->istate_lock);
 776
 777        if (iscsit_recalculate_dataout_values(cmd, pdu_offset, pdu_length,
 778                        &r2t_offset, &r2t_length) < 0)
 779                return DATAOUT_CANNOT_RECOVER;
 780
 781        iscsit_send_recovery_r2t(cmd, r2t_offset, r2t_length);
 782
 783        return DATAOUT_WITHIN_COMMAND_RECOVERY;
 784}
 785
 786static struct iscsi_ooo_cmdsn *iscsit_allocate_ooo_cmdsn(void)
 787{
 788        struct iscsi_ooo_cmdsn *ooo_cmdsn = NULL;
 789
 790        ooo_cmdsn = kmem_cache_zalloc(lio_ooo_cache, GFP_ATOMIC);
 791        if (!ooo_cmdsn) {
 792                pr_err("Unable to allocate memory for"
 793                        " struct iscsi_ooo_cmdsn.\n");
 794                return NULL;
 795        }
 796        INIT_LIST_HEAD(&ooo_cmdsn->ooo_list);
 797
 798        return ooo_cmdsn;
 799}
 800
 801/*
 802 *      Called with sess->cmdsn_mutex held.
 803 */
 804static int iscsit_attach_ooo_cmdsn(
 805        struct iscsi_session *sess,
 806        struct iscsi_ooo_cmdsn *ooo_cmdsn)
 807{
 808        struct iscsi_ooo_cmdsn *ooo_tail, *ooo_tmp;
 809        /*
 810         * We attach the struct iscsi_ooo_cmdsn entry to the out of order
 811         * list in increasing CmdSN order.
 812         * This allows iscsi_execute_ooo_cmdsns() to detect any
 813         * additional CmdSN holes while performing delayed execution.
 814         */
 815        if (list_empty(&sess->sess_ooo_cmdsn_list))
 816                list_add_tail(&ooo_cmdsn->ooo_list,
 817                                &sess->sess_ooo_cmdsn_list);
 818        else {
 819                ooo_tail = list_entry(sess->sess_ooo_cmdsn_list.prev,
 820                                typeof(*ooo_tail), ooo_list);
 821                /*
 822                 * CmdSN is greater than the tail of the list.
 823                 */
 824                if (iscsi_sna_lt(ooo_tail->cmdsn, ooo_cmdsn->cmdsn))
 825                        list_add_tail(&ooo_cmdsn->ooo_list,
 826                                        &sess->sess_ooo_cmdsn_list);
 827                else {
 828                        /*
 829                         * CmdSN is either lower than the head,  or somewhere
 830                         * in the middle.
 831                         */
 832                        list_for_each_entry(ooo_tmp, &sess->sess_ooo_cmdsn_list,
 833                                                ooo_list) {
 834                                if (iscsi_sna_lt(ooo_tmp->cmdsn, ooo_cmdsn->cmdsn))
 835                                        continue;
 836
 837                                /* Insert before this entry */
 838                                list_add(&ooo_cmdsn->ooo_list,
 839                                        ooo_tmp->ooo_list.prev);
 840                                break;
 841                        }
 842                }
 843        }
 844
 845        return 0;
 846}
 847
 848/*
 849 *      Removes an struct iscsi_ooo_cmdsn from a session's list,
 850 *      called with struct iscsi_session->cmdsn_mutex held.
 851 */
 852void iscsit_remove_ooo_cmdsn(
 853        struct iscsi_session *sess,
 854        struct iscsi_ooo_cmdsn *ooo_cmdsn)
 855{
 856        list_del(&ooo_cmdsn->ooo_list);
 857        kmem_cache_free(lio_ooo_cache, ooo_cmdsn);
 858}
 859
 860void iscsit_clear_ooo_cmdsns_for_conn(struct iscsi_conn *conn)
 861{
 862        struct iscsi_ooo_cmdsn *ooo_cmdsn;
 863        struct iscsi_session *sess = conn->sess;
 864
 865        mutex_lock(&sess->cmdsn_mutex);
 866        list_for_each_entry(ooo_cmdsn, &sess->sess_ooo_cmdsn_list, ooo_list) {
 867                if (ooo_cmdsn->cid != conn->cid)
 868                        continue;
 869
 870                ooo_cmdsn->cmd = NULL;
 871        }
 872        mutex_unlock(&sess->cmdsn_mutex);
 873}
 874
 875/*
 876 *      Called with sess->cmdsn_mutex held.
 877 */
 878int iscsit_execute_ooo_cmdsns(struct iscsi_session *sess)
 879{
 880        int ooo_count = 0;
 881        struct iscsi_cmd *cmd = NULL;
 882        struct iscsi_ooo_cmdsn *ooo_cmdsn, *ooo_cmdsn_tmp;
 883
 884        list_for_each_entry_safe(ooo_cmdsn, ooo_cmdsn_tmp,
 885                                &sess->sess_ooo_cmdsn_list, ooo_list) {
 886                if (ooo_cmdsn->cmdsn != sess->exp_cmd_sn)
 887                        continue;
 888
 889                if (!ooo_cmdsn->cmd) {
 890                        sess->exp_cmd_sn++;
 891                        iscsit_remove_ooo_cmdsn(sess, ooo_cmdsn);
 892                        continue;
 893                }
 894
 895                cmd = ooo_cmdsn->cmd;
 896                cmd->i_state = cmd->deferred_i_state;
 897                ooo_count++;
 898                sess->exp_cmd_sn++;
 899                pr_debug("Executing out of order CmdSN: 0x%08x,"
 900                        " incremented ExpCmdSN to 0x%08x.\n",
 901                        cmd->cmd_sn, sess->exp_cmd_sn);
 902
 903                iscsit_remove_ooo_cmdsn(sess, ooo_cmdsn);
 904
 905                if (iscsit_execute_cmd(cmd, 1) < 0)
 906                        return -1;
 907
 908                continue;
 909        }
 910
 911        return ooo_count;
 912}
 913
 914/*
 915 *      Called either:
 916 *
 917 *      1. With sess->cmdsn_mutex held from iscsi_execute_ooo_cmdsns()
 918 *      or iscsi_check_received_cmdsn().
 919 *      2. With no locks held directly from iscsi_handle_XXX_pdu() functions
 920 *      for immediate commands.
 921 */
 922int iscsit_execute_cmd(struct iscsi_cmd *cmd, int ooo)
 923{
 924        struct se_cmd *se_cmd = &cmd->se_cmd;
 925        struct iscsi_conn *conn = cmd->conn;
 926        int lr = 0;
 927
 928        spin_lock_bh(&cmd->istate_lock);
 929        if (ooo)
 930                cmd->cmd_flags &= ~ICF_OOO_CMDSN;
 931
 932        switch (cmd->iscsi_opcode) {
 933        case ISCSI_OP_SCSI_CMD:
 934                /*
 935                 * Go ahead and send the CHECK_CONDITION status for
 936                 * any SCSI CDB exceptions that may have occurred.
 937                 */
 938                if (cmd->sense_reason) {
 939                        if (cmd->sense_reason == TCM_RESERVATION_CONFLICT) {
 940                                cmd->i_state = ISTATE_SEND_STATUS;
 941                                spin_unlock_bh(&cmd->istate_lock);
 942                                iscsit_add_cmd_to_response_queue(cmd, cmd->conn,
 943                                                cmd->i_state);
 944                                return 0;
 945                        }
 946                        spin_unlock_bh(&cmd->istate_lock);
 947                        /*
 948                         * Determine if delayed TASK_ABORTED status for WRITEs
 949                         * should be sent now if no unsolicited data out
 950                         * payloads are expected, or if the delayed status
 951                         * should be sent after unsolicited data out with
 952                         * ISCSI_FLAG_CMD_FINAL set in iscsi_handle_data_out()
 953                         */
 954                        if (transport_check_aborted_status(se_cmd,
 955                                        (cmd->unsolicited_data == 0)) != 0)
 956                                return 0;
 957                        /*
 958                         * Otherwise send CHECK_CONDITION and sense for
 959                         * exception
 960                         */
 961                        return transport_send_check_condition_and_sense(se_cmd,
 962                                        cmd->sense_reason, 0);
 963                }
 964                /*
 965                 * Special case for delayed CmdSN with Immediate
 966                 * Data and/or Unsolicited Data Out attached.
 967                 */
 968                if (cmd->immediate_data) {
 969                        if (cmd->cmd_flags & ICF_GOT_LAST_DATAOUT) {
 970                                spin_unlock_bh(&cmd->istate_lock);
 971                                target_execute_cmd(&cmd->se_cmd);
 972                                return 0;
 973                        }
 974                        spin_unlock_bh(&cmd->istate_lock);
 975
 976                        if (!(cmd->cmd_flags &
 977                                        ICF_NON_IMMEDIATE_UNSOLICITED_DATA)) {
 978                                /*
 979                                 * Send the delayed TASK_ABORTED status for
 980                                 * WRITEs if no more unsolicitied data is
 981                                 * expected.
 982                                 */
 983                                if (transport_check_aborted_status(se_cmd, 1)
 984                                                != 0)
 985                                        return 0;
 986
 987                                iscsit_set_dataout_sequence_values(cmd);
 988                                conn->conn_transport->iscsit_get_dataout(conn, cmd, false);
 989                        }
 990                        return 0;
 991                }
 992                /*
 993                 * The default handler.
 994                 */
 995                spin_unlock_bh(&cmd->istate_lock);
 996
 997                if ((cmd->data_direction == DMA_TO_DEVICE) &&
 998                    !(cmd->cmd_flags & ICF_NON_IMMEDIATE_UNSOLICITED_DATA)) {
 999                        /*
1000                         * Send the delayed TASK_ABORTED status for WRITEs if
1001                         * no more nsolicitied data is expected.
1002                         */
1003                        if (transport_check_aborted_status(se_cmd, 1) != 0)
1004                                return 0;
1005
1006                        iscsit_set_unsoliticed_dataout(cmd);
1007                }
1008                return transport_handle_cdb_direct(&cmd->se_cmd);
1009
1010        case ISCSI_OP_NOOP_OUT:
1011        case ISCSI_OP_TEXT:
1012                spin_unlock_bh(&cmd->istate_lock);
1013                iscsit_add_cmd_to_response_queue(cmd, cmd->conn, cmd->i_state);
1014                break;
1015        case ISCSI_OP_SCSI_TMFUNC:
1016                if (cmd->se_cmd.se_tmr_req->response) {
1017                        spin_unlock_bh(&cmd->istate_lock);
1018                        iscsit_add_cmd_to_response_queue(cmd, cmd->conn,
1019                                        cmd->i_state);
1020                        return 0;
1021                }
1022                spin_unlock_bh(&cmd->istate_lock);
1023
1024                return transport_generic_handle_tmr(&cmd->se_cmd);
1025        case ISCSI_OP_LOGOUT:
1026                spin_unlock_bh(&cmd->istate_lock);
1027                switch (cmd->logout_reason) {
1028                case ISCSI_LOGOUT_REASON_CLOSE_SESSION:
1029                        lr = iscsit_logout_closesession(cmd, cmd->conn);
1030                        break;
1031                case ISCSI_LOGOUT_REASON_CLOSE_CONNECTION:
1032                        lr = iscsit_logout_closeconnection(cmd, cmd->conn);
1033                        break;
1034                case ISCSI_LOGOUT_REASON_RECOVERY:
1035                        lr = iscsit_logout_removeconnforrecovery(cmd, cmd->conn);
1036                        break;
1037                default:
1038                        pr_err("Unknown iSCSI Logout Request Code:"
1039                                " 0x%02x\n", cmd->logout_reason);
1040                        return -1;
1041                }
1042
1043                return lr;
1044        default:
1045                spin_unlock_bh(&cmd->istate_lock);
1046                pr_err("Cannot perform out of order execution for"
1047                " unknown iSCSI Opcode: 0x%02x\n", cmd->iscsi_opcode);
1048                return -1;
1049        }
1050
1051        return 0;
1052}
1053
1054void iscsit_free_all_ooo_cmdsns(struct iscsi_session *sess)
1055{
1056        struct iscsi_ooo_cmdsn *ooo_cmdsn, *ooo_cmdsn_tmp;
1057
1058        mutex_lock(&sess->cmdsn_mutex);
1059        list_for_each_entry_safe(ooo_cmdsn, ooo_cmdsn_tmp,
1060                        &sess->sess_ooo_cmdsn_list, ooo_list) {
1061
1062                list_del(&ooo_cmdsn->ooo_list);
1063                kmem_cache_free(lio_ooo_cache, ooo_cmdsn);
1064        }
1065        mutex_unlock(&sess->cmdsn_mutex);
1066}
1067
1068int iscsit_handle_ooo_cmdsn(
1069        struct iscsi_session *sess,
1070        struct iscsi_cmd *cmd,
1071        u32 cmdsn)
1072{
1073        int batch = 0;
1074        struct iscsi_ooo_cmdsn *ooo_cmdsn = NULL, *ooo_tail = NULL;
1075
1076        cmd->deferred_i_state           = cmd->i_state;
1077        cmd->i_state                    = ISTATE_DEFERRED_CMD;
1078        cmd->cmd_flags                  |= ICF_OOO_CMDSN;
1079
1080        if (list_empty(&sess->sess_ooo_cmdsn_list))
1081                batch = 1;
1082        else {
1083                ooo_tail = list_entry(sess->sess_ooo_cmdsn_list.prev,
1084                                typeof(*ooo_tail), ooo_list);
1085                if (ooo_tail->cmdsn != (cmdsn - 1))
1086                        batch = 1;
1087        }
1088
1089        ooo_cmdsn = iscsit_allocate_ooo_cmdsn();
1090        if (!ooo_cmdsn)
1091                return -ENOMEM;
1092
1093        ooo_cmdsn->cmd                  = cmd;
1094        ooo_cmdsn->batch_count          = (batch) ?
1095                                          (cmdsn - sess->exp_cmd_sn) : 1;
1096        ooo_cmdsn->cid                  = cmd->conn->cid;
1097        ooo_cmdsn->exp_cmdsn            = sess->exp_cmd_sn;
1098        ooo_cmdsn->cmdsn                = cmdsn;
1099
1100        if (iscsit_attach_ooo_cmdsn(sess, ooo_cmdsn) < 0) {
1101                kmem_cache_free(lio_ooo_cache, ooo_cmdsn);
1102                return -ENOMEM;
1103        }
1104
1105        return 0;
1106}
1107
1108static int iscsit_set_dataout_timeout_values(
1109        struct iscsi_cmd *cmd,
1110        u32 *offset,
1111        u32 *length)
1112{
1113        struct iscsi_conn *conn = cmd->conn;
1114        struct iscsi_r2t *r2t;
1115
1116        if (cmd->unsolicited_data) {
1117                *offset = 0;
1118                *length = (conn->sess->sess_ops->FirstBurstLength >
1119                           cmd->se_cmd.data_length) ?
1120                           cmd->se_cmd.data_length :
1121                           conn->sess->sess_ops->FirstBurstLength;
1122                return 0;
1123        }
1124
1125        spin_lock_bh(&cmd->r2t_lock);
1126        if (list_empty(&cmd->cmd_r2t_list)) {
1127                pr_err("cmd->cmd_r2t_list is empty!\n");
1128                spin_unlock_bh(&cmd->r2t_lock);
1129                return -1;
1130        }
1131
1132        list_for_each_entry(r2t, &cmd->cmd_r2t_list, r2t_list) {
1133                if (r2t->sent_r2t && !r2t->recovery_r2t && !r2t->seq_complete) {
1134                        *offset = r2t->offset;
1135                        *length = r2t->xfer_len;
1136                        spin_unlock_bh(&cmd->r2t_lock);
1137                        return 0;
1138                }
1139        }
1140        spin_unlock_bh(&cmd->r2t_lock);
1141
1142        pr_err("Unable to locate any incomplete DataOUT"
1143                " sequences for ITT: 0x%08x.\n", cmd->init_task_tag);
1144
1145        return -1;
1146}
1147
1148/*
1149 *      NOTE: Called from interrupt (timer) context.
1150 */
1151static void iscsit_handle_dataout_timeout(unsigned long data)
1152{
1153        u32 pdu_length = 0, pdu_offset = 0;
1154        u32 r2t_length = 0, r2t_offset = 0;
1155        struct iscsi_cmd *cmd = (struct iscsi_cmd *) data;
1156        struct iscsi_conn *conn = cmd->conn;
1157        struct iscsi_session *sess = NULL;
1158        struct iscsi_node_attrib *na;
1159
1160        iscsit_inc_conn_usage_count(conn);
1161
1162        spin_lock_bh(&cmd->dataout_timeout_lock);
1163        if (cmd->dataout_timer_flags & ISCSI_TF_STOP) {
1164                spin_unlock_bh(&cmd->dataout_timeout_lock);
1165                iscsit_dec_conn_usage_count(conn);
1166                return;
1167        }
1168        cmd->dataout_timer_flags &= ~ISCSI_TF_RUNNING;
1169        sess = conn->sess;
1170        na = iscsit_tpg_get_node_attrib(sess);
1171
1172        if (!sess->sess_ops->ErrorRecoveryLevel) {
1173                pr_debug("Unable to recover from DataOut timeout while"
1174                        " in ERL=0.\n");
1175                goto failure;
1176        }
1177
1178        if (++cmd->dataout_timeout_retries == na->dataout_timeout_retries) {
1179                pr_debug("Command ITT: 0x%08x exceeded max retries"
1180                        " for DataOUT timeout %u, closing iSCSI connection.\n",
1181                        cmd->init_task_tag, na->dataout_timeout_retries);
1182                goto failure;
1183        }
1184
1185        cmd->cmd_flags |= ICF_WITHIN_COMMAND_RECOVERY;
1186
1187        if (conn->sess->sess_ops->DataSequenceInOrder) {
1188                if (conn->sess->sess_ops->DataPDUInOrder) {
1189                        pdu_offset = cmd->write_data_done;
1190                        if ((pdu_offset + (conn->sess->sess_ops->MaxBurstLength -
1191                             cmd->next_burst_len)) > cmd->se_cmd.data_length)
1192                                pdu_length = (cmd->se_cmd.data_length -
1193                                        cmd->write_data_done);
1194                        else
1195                                pdu_length = (conn->sess->sess_ops->MaxBurstLength -
1196                                                cmd->next_burst_len);
1197                } else {
1198                        pdu_offset = cmd->seq_start_offset;
1199                        pdu_length = (cmd->seq_end_offset -
1200                                cmd->seq_start_offset);
1201                }
1202        } else {
1203                if (iscsit_set_dataout_timeout_values(cmd, &pdu_offset,
1204                                &pdu_length) < 0)
1205                        goto failure;
1206        }
1207
1208        if (iscsit_recalculate_dataout_values(cmd, pdu_offset, pdu_length,
1209                        &r2t_offset, &r2t_length) < 0)
1210                goto failure;
1211
1212        pr_debug("Command ITT: 0x%08x timed out waiting for"
1213                " completion of %sDataOUT Sequence Offset: %u, Length: %u\n",
1214                cmd->init_task_tag, (cmd->unsolicited_data) ? "Unsolicited " :
1215                "", r2t_offset, r2t_length);
1216
1217        if (iscsit_send_recovery_r2t(cmd, r2t_offset, r2t_length) < 0)
1218                goto failure;
1219
1220        iscsit_start_dataout_timer(cmd, conn);
1221        spin_unlock_bh(&cmd->dataout_timeout_lock);
1222        iscsit_dec_conn_usage_count(conn);
1223
1224        return;
1225
1226failure:
1227        spin_unlock_bh(&cmd->dataout_timeout_lock);
1228        iscsit_cause_connection_reinstatement(conn, 0);
1229        iscsit_dec_conn_usage_count(conn);
1230}
1231
1232void iscsit_mod_dataout_timer(struct iscsi_cmd *cmd)
1233{
1234        struct iscsi_conn *conn = cmd->conn;
1235        struct iscsi_session *sess = conn->sess;
1236        struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
1237
1238        spin_lock_bh(&cmd->dataout_timeout_lock);
1239        if (!(cmd->dataout_timer_flags & ISCSI_TF_RUNNING)) {
1240                spin_unlock_bh(&cmd->dataout_timeout_lock);
1241                return;
1242        }
1243
1244        mod_timer(&cmd->dataout_timer,
1245                (get_jiffies_64() + na->dataout_timeout * HZ));
1246        pr_debug("Updated DataOUT timer for ITT: 0x%08x",
1247                        cmd->init_task_tag);
1248        spin_unlock_bh(&cmd->dataout_timeout_lock);
1249}
1250
1251/*
1252 *      Called with cmd->dataout_timeout_lock held.
1253 */
1254void iscsit_start_dataout_timer(
1255        struct iscsi_cmd *cmd,
1256        struct iscsi_conn *conn)
1257{
1258        struct iscsi_session *sess = conn->sess;
1259        struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
1260
1261        if (cmd->dataout_timer_flags & ISCSI_TF_RUNNING)
1262                return;
1263
1264        pr_debug("Starting DataOUT timer for ITT: 0x%08x on"
1265                " CID: %hu.\n", cmd->init_task_tag, conn->cid);
1266
1267        init_timer(&cmd->dataout_timer);
1268        cmd->dataout_timer.expires = (get_jiffies_64() + na->dataout_timeout * HZ);
1269        cmd->dataout_timer.data = (unsigned long)cmd;
1270        cmd->dataout_timer.function = iscsit_handle_dataout_timeout;
1271        cmd->dataout_timer_flags &= ~ISCSI_TF_STOP;
1272        cmd->dataout_timer_flags |= ISCSI_TF_RUNNING;
1273        add_timer(&cmd->dataout_timer);
1274}
1275
1276void iscsit_stop_dataout_timer(struct iscsi_cmd *cmd)
1277{
1278        spin_lock_bh(&cmd->dataout_timeout_lock);
1279        if (!(cmd->dataout_timer_flags & ISCSI_TF_RUNNING)) {
1280                spin_unlock_bh(&cmd->dataout_timeout_lock);
1281                return;
1282        }
1283        cmd->dataout_timer_flags |= ISCSI_TF_STOP;
1284        spin_unlock_bh(&cmd->dataout_timeout_lock);
1285
1286        del_timer_sync(&cmd->dataout_timer);
1287
1288        spin_lock_bh(&cmd->dataout_timeout_lock);
1289        cmd->dataout_timer_flags &= ~ISCSI_TF_RUNNING;
1290        pr_debug("Stopped DataOUT Timer for ITT: 0x%08x\n",
1291                        cmd->init_task_tag);
1292        spin_unlock_bh(&cmd->dataout_timeout_lock);
1293}
1294EXPORT_SYMBOL(iscsit_stop_dataout_timer);
1295