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 <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 */
  46int iscsit_dump_data_payload(
  47        struct iscsi_conn *conn,
  48        u32 buf_len,
  49        int dump_padding_digest)
  50{
  51        char *buf, pad_bytes[4];
  52        int ret = DATAOUT_WITHIN_COMMAND_RECOVERY, rx_got;
  53        u32 length, padding, offset = 0, size;
  54        struct kvec iov;
  55
  56        if (conn->sess->sess_ops->RDMAExtensions)
  57                return 0;
  58
  59        length = min(buf_len, OFFLOAD_BUF_SIZE);
  60
  61        buf = kzalloc(length, GFP_ATOMIC);
  62        if (!buf) {
  63                pr_err("Unable to allocate %u bytes for offload"
  64                                " buffer.\n", length);
  65                return -1;
  66        }
  67        memset(&iov, 0, sizeof(struct kvec));
  68
  69        while (offset < buf_len) {
  70                size = min(buf_len - offset, length);
  71
  72                iov.iov_len = size;
  73                iov.iov_base = buf;
  74
  75                rx_got = rx_data(conn, &iov, 1, size);
  76                if (rx_got != size) {
  77                        ret = DATAOUT_CANNOT_RECOVER;
  78                        goto out;
  79                }
  80
  81                offset += size;
  82        }
  83
  84        if (!dump_padding_digest)
  85                goto out;
  86
  87        padding = ((-buf_len) & 3);
  88        if (padding != 0) {
  89                iov.iov_len = padding;
  90                iov.iov_base = pad_bytes;
  91
  92                rx_got = rx_data(conn, &iov, 1, padding);
  93                if (rx_got != padding) {
  94                        ret = DATAOUT_CANNOT_RECOVER;
  95                        goto out;
  96                }
  97        }
  98
  99        if (conn->conn_ops->DataDigest) {
 100                u32 data_crc;
 101
 102                iov.iov_len = ISCSI_CRC_LEN;
 103                iov.iov_base = &data_crc;
 104
 105                rx_got = rx_data(conn, &iov, 1, ISCSI_CRC_LEN);
 106                if (rx_got != ISCSI_CRC_LEN) {
 107                        ret = DATAOUT_CANNOT_RECOVER;
 108                        goto out;
 109                }
 110        }
 111
 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, ISCSI_REASON_PROTOCOL_ERROR, buf);
 164        }
 165
 166        if (runlength) {
 167                if ((begrun + runlength) > cmd->r2t_sn) {
 168                        pr_err("Command ITT: 0x%08x received R2T SNACK"
 169                        " with BegRun: 0x%08x, RunLength: 0x%08x, exceeds"
 170                        " current R2TSN: 0x%08x, protocol error.\n",
 171                        cmd->init_task_tag, begrun, runlength, cmd->r2t_sn);
 172                        return iscsit_reject_cmd(cmd,
 173                                        ISCSI_REASON_BOOKMARK_INVALID, buf);
 174                }
 175                last_r2tsn = (begrun + runlength);
 176        } else
 177                last_r2tsn = cmd->r2t_sn;
 178
 179        while (begrun < last_r2tsn) {
 180                r2t = iscsit_get_holder_for_r2tsn(cmd, begrun);
 181                if (!r2t)
 182                        return -1;
 183                if (iscsit_send_recovery_r2t_for_snack(cmd, r2t) < 0)
 184                        return -1;
 185
 186                begrun++;
 187        }
 188
 189        return 0;
 190}
 191
 192/*
 193 *      Generates Offsets and NextBurstLength based on Begrun and Runlength
 194 *      carried in a Data SNACK or ExpDataSN in TMR TASK_REASSIGN.
 195 *
 196 *      For DataSequenceInOrder=Yes and DataPDUInOrder=[Yes,No] only.
 197 *
 198 *      FIXME: How is this handled for a RData SNACK?
 199 */
 200int iscsit_create_recovery_datain_values_datasequenceinorder_yes(
 201        struct iscsi_cmd *cmd,
 202        struct iscsi_datain_req *dr)
 203{
 204        u32 data_sn = 0, data_sn_count = 0;
 205        u32 pdu_start = 0, seq_no = 0;
 206        u32 begrun = dr->begrun;
 207        struct iscsi_conn *conn = cmd->conn;
 208
 209        while (begrun > data_sn++) {
 210                data_sn_count++;
 211                if ((dr->next_burst_len +
 212                     conn->conn_ops->MaxRecvDataSegmentLength) <
 213                     conn->sess->sess_ops->MaxBurstLength) {
 214                        dr->read_data_done +=
 215                                conn->conn_ops->MaxRecvDataSegmentLength;
 216                        dr->next_burst_len +=
 217                                conn->conn_ops->MaxRecvDataSegmentLength;
 218                } else {
 219                        dr->read_data_done +=
 220                                (conn->sess->sess_ops->MaxBurstLength -
 221                                 dr->next_burst_len);
 222                        dr->next_burst_len = 0;
 223                        pdu_start += data_sn_count;
 224                        data_sn_count = 0;
 225                        seq_no++;
 226                }
 227        }
 228
 229        if (!conn->sess->sess_ops->DataPDUInOrder) {
 230                cmd->seq_no = seq_no;
 231                cmd->pdu_start = pdu_start;
 232                cmd->pdu_send_order = data_sn_count;
 233        }
 234
 235        return 0;
 236}
 237
 238/*
 239 *      Generates Offsets and NextBurstLength based on Begrun and Runlength
 240 *      carried in a Data SNACK or ExpDataSN in TMR TASK_REASSIGN.
 241 *
 242 *      For DataSequenceInOrder=No and DataPDUInOrder=[Yes,No] only.
 243 *
 244 *      FIXME: How is this handled for a RData SNACK?
 245 */
 246int iscsit_create_recovery_datain_values_datasequenceinorder_no(
 247        struct iscsi_cmd *cmd,
 248        struct iscsi_datain_req *dr)
 249{
 250        int found_seq = 0, i;
 251        u32 data_sn, read_data_done = 0, seq_send_order = 0;
 252        u32 begrun = dr->begrun;
 253        u32 runlength = dr->runlength;
 254        struct iscsi_conn *conn = cmd->conn;
 255        struct iscsi_seq *first_seq = NULL, *seq = NULL;
 256
 257        if (!cmd->seq_list) {
 258                pr_err("struct iscsi_cmd->seq_list is NULL!\n");
 259                return -1;
 260        }
 261
 262        /*
 263         * Calculate read_data_done for all sequences containing a
 264         * first_datasn and last_datasn less than the BegRun.
 265         *
 266         * Locate the struct iscsi_seq the BegRun lies within and calculate
 267         * NextBurstLenghth up to the DataSN based on MaxRecvDataSegmentLength.
 268         *
 269         * Also use struct iscsi_seq->seq_send_order to determine where to start.
 270         */
 271        for (i = 0; i < cmd->seq_count; i++) {
 272                seq = &cmd->seq_list[i];
 273
 274                if (!seq->seq_send_order)
 275                        first_seq = seq;
 276
 277                /*
 278                 * No data has been transferred for this DataIN sequence, so the
 279                 * seq->first_datasn and seq->last_datasn have not been set.
 280                 */
 281                if (!seq->sent) {
 282                        pr_err("Ignoring non-sent sequence 0x%08x ->"
 283                                " 0x%08x\n\n", seq->first_datasn,
 284                                seq->last_datasn);
 285                        continue;
 286                }
 287
 288                /*
 289                 * This DataIN sequence is precedes the received BegRun, add the
 290                 * total xfer_len of the sequence to read_data_done and reset
 291                 * seq->pdu_send_order.
 292                 */
 293                if ((seq->first_datasn < begrun) &&
 294                                (seq->last_datasn < begrun)) {
 295                        pr_err("Pre BegRun sequence 0x%08x ->"
 296                                " 0x%08x\n", seq->first_datasn,
 297                                seq->last_datasn);
 298
 299                        read_data_done += cmd->seq_list[i].xfer_len;
 300                        seq->next_burst_len = seq->pdu_send_order = 0;
 301                        continue;
 302                }
 303
 304                /*
 305                 * The BegRun lies within this DataIN sequence.
 306                 */
 307                if ((seq->first_datasn <= begrun) &&
 308                                (seq->last_datasn >= begrun)) {
 309                        pr_err("Found sequence begrun: 0x%08x in"
 310                                " 0x%08x -> 0x%08x\n", begrun,
 311                                seq->first_datasn, seq->last_datasn);
 312
 313                        seq_send_order = seq->seq_send_order;
 314                        data_sn = seq->first_datasn;
 315                        seq->next_burst_len = seq->pdu_send_order = 0;
 316                        found_seq = 1;
 317
 318                        /*
 319                         * For DataPDUInOrder=Yes, while the first DataSN of
 320                         * the sequence is less than the received BegRun, add
 321                         * the MaxRecvDataSegmentLength to read_data_done and
 322                         * to the sequence's next_burst_len;
 323                         *
 324                         * For DataPDUInOrder=No, while the first DataSN of the
 325                         * sequence is less than the received BegRun, find the
 326                         * struct iscsi_pdu of the DataSN in question and add the
 327                         * MaxRecvDataSegmentLength to read_data_done and to the
 328                         * sequence's next_burst_len;
 329                         */
 330                        if (conn->sess->sess_ops->DataPDUInOrder) {
 331                                while (data_sn < begrun) {
 332                                        seq->pdu_send_order++;
 333                                        read_data_done +=
 334                                                conn->conn_ops->MaxRecvDataSegmentLength;
 335                                        seq->next_burst_len +=
 336                                                conn->conn_ops->MaxRecvDataSegmentLength;
 337                                        data_sn++;
 338                                }
 339                        } else {
 340                                int j;
 341                                struct iscsi_pdu *pdu;
 342
 343                                while (data_sn < begrun) {
 344                                        seq->pdu_send_order++;
 345
 346                                        for (j = 0; j < seq->pdu_count; j++) {
 347                                                pdu = &cmd->pdu_list[
 348                                                        seq->pdu_start + j];
 349                                                if (pdu->data_sn == data_sn) {
 350                                                        read_data_done +=
 351                                                                pdu->length;
 352                                                        seq->next_burst_len +=
 353                                                                pdu->length;
 354                                                }
 355                                        }
 356                                        data_sn++;
 357                                }
 358                        }
 359                        continue;
 360                }
 361
 362                /*
 363                 * This DataIN sequence is larger than the received BegRun,
 364                 * reset seq->pdu_send_order and continue.
 365                 */
 366                if ((seq->first_datasn > begrun) ||
 367                                (seq->last_datasn > begrun)) {
 368                        pr_err("Post BegRun sequence 0x%08x -> 0x%08x\n",
 369                                        seq->first_datasn, seq->last_datasn);
 370
 371                        seq->next_burst_len = seq->pdu_send_order = 0;
 372                        continue;
 373                }
 374        }
 375
 376        if (!found_seq) {
 377                if (!begrun) {
 378                        if (!first_seq) {
 379                                pr_err("ITT: 0x%08x, Begrun: 0x%08x"
 380                                        " but first_seq is NULL\n",
 381                                        cmd->init_task_tag, begrun);
 382                                return -1;
 383                        }
 384                        seq_send_order = first_seq->seq_send_order;
 385                        seq->next_burst_len = seq->pdu_send_order = 0;
 386                        goto done;
 387                }
 388
 389                pr_err("Unable to locate struct iscsi_seq for ITT: 0x%08x,"
 390                        " BegRun: 0x%08x, RunLength: 0x%08x while"
 391                        " DataSequenceInOrder=No and DataPDUInOrder=%s.\n",
 392                                cmd->init_task_tag, begrun, runlength,
 393                        (conn->sess->sess_ops->DataPDUInOrder) ? "Yes" : "No");
 394                return -1;
 395        }
 396
 397done:
 398        dr->read_data_done = read_data_done;
 399        dr->seq_send_order = seq_send_order;
 400
 401        return 0;
 402}
 403
 404static int iscsit_handle_recovery_datain(
 405        struct iscsi_cmd *cmd,
 406        unsigned char *buf,
 407        u32 begrun,
 408        u32 runlength)
 409{
 410        struct iscsi_conn *conn = cmd->conn;
 411        struct iscsi_datain_req *dr;
 412        struct se_cmd *se_cmd = &cmd->se_cmd;
 413
 414        if (!(se_cmd->transport_state & CMD_T_COMPLETE)) {
 415                pr_err("Ignoring ITT: 0x%08x Data SNACK\n",
 416                                cmd->init_task_tag);
 417                return 0;
 418        }
 419
 420        /*
 421         * Make sure the initiator is not requesting retransmission
 422         * of DataSNs already acknowledged by a Data ACK SNACK.
 423         */
 424        if ((cmd->cmd_flags & ICF_GOT_DATACK_SNACK) &&
 425            (begrun <= cmd->acked_data_sn)) {
 426                pr_err("ITT: 0x%08x, Data SNACK requesting"
 427                        " retransmission of DataSN: 0x%08x to 0x%08x but"
 428                        " already acked to DataSN: 0x%08x by Data ACK SNACK,"
 429                        " protocol error.\n", cmd->init_task_tag, begrun,
 430                        (begrun + runlength), cmd->acked_data_sn);
 431
 432                return iscsit_reject_cmd(cmd, ISCSI_REASON_PROTOCOL_ERROR, buf);
 433        }
 434
 435        /*
 436         * Make sure BegRun and RunLength in the Data SNACK are sane.
 437         * Note: (cmd->data_sn - 1) will carry the maximum DataSN sent.
 438         */
 439        if ((begrun + runlength) > (cmd->data_sn - 1)) {
 440                pr_err("Initiator requesting BegRun: 0x%08x, RunLength"
 441                        ": 0x%08x greater than maximum DataSN: 0x%08x.\n",
 442                                begrun, runlength, (cmd->data_sn - 1));
 443                return iscsit_reject_cmd(cmd, ISCSI_REASON_BOOKMARK_INVALID,
 444                                         buf);
 445        }
 446
 447        dr = iscsit_allocate_datain_req();
 448        if (!dr)
 449                return iscsit_reject_cmd(cmd, ISCSI_REASON_BOOKMARK_NO_RESOURCES,
 450                                         buf);
 451
 452        dr->data_sn = dr->begrun = begrun;
 453        dr->runlength = runlength;
 454        dr->generate_recovery_values = 1;
 455        dr->recovery = DATAIN_WITHIN_COMMAND_RECOVERY;
 456
 457        iscsit_attach_datain_req(cmd, dr);
 458
 459        cmd->i_state = ISTATE_SEND_DATAIN;
 460        iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
 461
 462        return 0;
 463}
 464
 465int iscsit_handle_recovery_datain_or_r2t(
 466        struct iscsi_conn *conn,
 467        unsigned char *buf,
 468        itt_t init_task_tag,
 469        u32 targ_xfer_tag,
 470        u32 begrun,
 471        u32 runlength)
 472{
 473        struct iscsi_cmd *cmd;
 474
 475        cmd = iscsit_find_cmd_from_itt(conn, init_task_tag);
 476        if (!cmd)
 477                return 0;
 478
 479        /*
 480         * FIXME: This will not work for bidi commands.
 481         */
 482        switch (cmd->data_direction) {
 483        case DMA_TO_DEVICE:
 484                return iscsit_handle_r2t_snack(cmd, buf, begrun, runlength);
 485        case DMA_FROM_DEVICE:
 486                return iscsit_handle_recovery_datain(cmd, buf, begrun,
 487                                runlength);
 488        default:
 489                pr_err("Unknown cmd->data_direction: 0x%02x\n",
 490                                cmd->data_direction);
 491                return -1;
 492        }
 493
 494        return 0;
 495}
 496
 497/* #warning FIXME: Status SNACK needs to be dependent on OPCODE!!! */
 498int iscsit_handle_status_snack(
 499        struct iscsi_conn *conn,
 500        itt_t init_task_tag,
 501        u32 targ_xfer_tag,
 502        u32 begrun,
 503        u32 runlength)
 504{
 505        struct iscsi_cmd *cmd = NULL;
 506        u32 last_statsn;
 507        int found_cmd;
 508
 509        if (!begrun) {
 510                begrun = conn->exp_statsn;
 511        } else if (conn->exp_statsn > begrun) {
 512                pr_err("Got Status SNACK Begrun: 0x%08x, RunLength:"
 513                        " 0x%08x but already got ExpStatSN: 0x%08x on CID:"
 514                        " %hu.\n", begrun, runlength, conn->exp_statsn,
 515                        conn->cid);
 516                return 0;
 517        }
 518
 519        last_statsn = (!runlength) ? conn->stat_sn : (begrun + runlength);
 520
 521        while (begrun < last_statsn) {
 522                found_cmd = 0;
 523
 524                spin_lock_bh(&conn->cmd_lock);
 525                list_for_each_entry(cmd, &conn->conn_cmd_list, i_conn_node) {
 526                        if (cmd->stat_sn == begrun) {
 527                                found_cmd = 1;
 528                                break;
 529                        }
 530                }
 531                spin_unlock_bh(&conn->cmd_lock);
 532
 533                if (!found_cmd) {
 534                        pr_err("Unable to find StatSN: 0x%08x for"
 535                                " a Status SNACK, assuming this was a"
 536                                " protactic SNACK for an untransmitted"
 537                                " StatSN, ignoring.\n", begrun);
 538                        begrun++;
 539                        continue;
 540                }
 541
 542                spin_lock_bh(&cmd->istate_lock);
 543                if (cmd->i_state == ISTATE_SEND_DATAIN) {
 544                        spin_unlock_bh(&cmd->istate_lock);
 545                        pr_err("Ignoring Status SNACK for BegRun:"
 546                                " 0x%08x, RunLength: 0x%08x, assuming this was"
 547                                " a protactic SNACK for an untransmitted"
 548                                " StatSN\n", begrun, runlength);
 549                        begrun++;
 550                        continue;
 551                }
 552                spin_unlock_bh(&cmd->istate_lock);
 553
 554                cmd->i_state = ISTATE_SEND_STATUS_RECOVERY;
 555                iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
 556                begrun++;
 557        }
 558
 559        return 0;
 560}
 561
 562int iscsit_handle_data_ack(
 563        struct iscsi_conn *conn,
 564        u32 targ_xfer_tag,
 565        u32 begrun,
 566        u32 runlength)
 567{
 568        struct iscsi_cmd *cmd = NULL;
 569
 570        cmd = iscsit_find_cmd_from_ttt(conn, targ_xfer_tag);
 571        if (!cmd) {
 572                pr_err("Data ACK SNACK for TTT: 0x%08x is"
 573                        " invalid.\n", targ_xfer_tag);
 574                return -1;
 575        }
 576
 577        if (begrun <= cmd->acked_data_sn) {
 578                pr_err("ITT: 0x%08x Data ACK SNACK BegRUN: 0x%08x is"
 579                        " less than the already acked DataSN: 0x%08x.\n",
 580                        cmd->init_task_tag, begrun, cmd->acked_data_sn);
 581                return -1;
 582        }
 583
 584        /*
 585         * For Data ACK SNACK, BegRun is the next expected DataSN.
 586         * (see iSCSI v19: 10.16.6)
 587         */
 588        cmd->cmd_flags |= ICF_GOT_DATACK_SNACK;
 589        cmd->acked_data_sn = (begrun - 1);
 590
 591        pr_debug("Received Data ACK SNACK for ITT: 0x%08x,"
 592                " updated acked DataSN to 0x%08x.\n",
 593                        cmd->init_task_tag, cmd->acked_data_sn);
 594
 595        return 0;
 596}
 597
 598static int iscsit_send_recovery_r2t(
 599        struct iscsi_cmd *cmd,
 600        u32 offset,
 601        u32 xfer_len)
 602{
 603        int ret;
 604
 605        spin_lock_bh(&cmd->r2t_lock);
 606        ret = iscsit_add_r2t_to_list(cmd, offset, xfer_len, 1, 0);
 607        spin_unlock_bh(&cmd->r2t_lock);
 608
 609        return ret;
 610}
 611
 612int iscsit_dataout_datapduinorder_no_fbit(
 613        struct iscsi_cmd *cmd,
 614        struct iscsi_pdu *pdu)
 615{
 616        int i, send_recovery_r2t = 0, recovery = 0;
 617        u32 length = 0, offset = 0, pdu_count = 0, xfer_len = 0;
 618        struct iscsi_conn *conn = cmd->conn;
 619        struct iscsi_pdu *first_pdu = NULL;
 620
 621        /*
 622         * Get an struct iscsi_pdu pointer to the first PDU, and total PDU count
 623         * of the DataOUT sequence.
 624         */
 625        if (conn->sess->sess_ops->DataSequenceInOrder) {
 626                for (i = 0; i < cmd->pdu_count; i++) {
 627                        if (cmd->pdu_list[i].seq_no == pdu->seq_no) {
 628                                if (!first_pdu)
 629                                        first_pdu = &cmd->pdu_list[i];
 630                                xfer_len += cmd->pdu_list[i].length;
 631                                pdu_count++;
 632                        } else if (pdu_count)
 633                                break;
 634                }
 635        } else {
 636                struct iscsi_seq *seq = cmd->seq_ptr;
 637
 638                first_pdu = &cmd->pdu_list[seq->pdu_start];
 639                pdu_count = seq->pdu_count;
 640        }
 641
 642        if (!first_pdu || !pdu_count)
 643                return DATAOUT_CANNOT_RECOVER;
 644
 645        /*
 646         * Loop through the ending DataOUT Sequence checking each struct iscsi_pdu.
 647         * The following ugly logic does batching of not received PDUs.
 648         */
 649        for (i = 0; i < pdu_count; i++) {
 650                if (first_pdu[i].status == ISCSI_PDU_RECEIVED_OK) {
 651                        if (!send_recovery_r2t)
 652                                continue;
 653
 654                        if (iscsit_send_recovery_r2t(cmd, offset, length) < 0)
 655                                return DATAOUT_CANNOT_RECOVER;
 656
 657                        send_recovery_r2t = length = offset = 0;
 658                        continue;
 659                }
 660                /*
 661                 * Set recovery = 1 for any missing, CRC failed, or timed
 662                 * out PDUs to let the DataOUT logic know that this sequence
 663                 * has not been completed yet.
 664                 *
 665                 * Also, only send a Recovery R2T for ISCSI_PDU_NOT_RECEIVED.
 666                 * We assume if the PDU either failed CRC or timed out
 667                 * that a Recovery R2T has already been sent.
 668                 */
 669                recovery = 1;
 670
 671                if (first_pdu[i].status != ISCSI_PDU_NOT_RECEIVED)
 672                        continue;
 673
 674                if (!offset)
 675                        offset = first_pdu[i].offset;
 676                length += first_pdu[i].length;
 677
 678                send_recovery_r2t = 1;
 679        }
 680
 681        if (send_recovery_r2t)
 682                if (iscsit_send_recovery_r2t(cmd, offset, length) < 0)
 683                        return DATAOUT_CANNOT_RECOVER;
 684
 685        return (!recovery) ? DATAOUT_NORMAL : DATAOUT_WITHIN_COMMAND_RECOVERY;
 686}
 687
 688static int iscsit_recalculate_dataout_values(
 689        struct iscsi_cmd *cmd,
 690        u32 pdu_offset,
 691        u32 pdu_length,
 692        u32 *r2t_offset,
 693        u32 *r2t_length)
 694{
 695        int i;
 696        struct iscsi_conn *conn = cmd->conn;
 697        struct iscsi_pdu *pdu = NULL;
 698
 699        if (conn->sess->sess_ops->DataSequenceInOrder) {
 700                cmd->data_sn = 0;
 701
 702                if (conn->sess->sess_ops->DataPDUInOrder) {
 703                        *r2t_offset = cmd->write_data_done;
 704                        *r2t_length = (cmd->seq_end_offset -
 705                                        cmd->write_data_done);
 706                        return 0;
 707                }
 708
 709                *r2t_offset = cmd->seq_start_offset;
 710                *r2t_length = (cmd->seq_end_offset - cmd->seq_start_offset);
 711
 712                for (i = 0; i < cmd->pdu_count; i++) {
 713                        pdu = &cmd->pdu_list[i];
 714
 715                        if (pdu->status != ISCSI_PDU_RECEIVED_OK)
 716                                continue;
 717
 718                        if ((pdu->offset >= cmd->seq_start_offset) &&
 719                           ((pdu->offset + pdu->length) <=
 720                             cmd->seq_end_offset)) {
 721                                if (!cmd->unsolicited_data)
 722                                        cmd->next_burst_len -= pdu->length;
 723                                else
 724                                        cmd->first_burst_len -= pdu->length;
 725
 726                                cmd->write_data_done -= pdu->length;
 727                                pdu->status = ISCSI_PDU_NOT_RECEIVED;
 728                        }
 729                }
 730        } else {
 731                struct iscsi_seq *seq = NULL;
 732
 733                seq = iscsit_get_seq_holder(cmd, pdu_offset, pdu_length);
 734                if (!seq)
 735                        return -1;
 736
 737                *r2t_offset = seq->orig_offset;
 738                *r2t_length = seq->xfer_len;
 739
 740                cmd->write_data_done -= (seq->offset - seq->orig_offset);
 741                if (cmd->immediate_data)
 742                        cmd->first_burst_len = cmd->write_data_done;
 743
 744                seq->data_sn = 0;
 745                seq->offset = seq->orig_offset;
 746                seq->next_burst_len = 0;
 747                seq->status = DATAOUT_SEQUENCE_WITHIN_COMMAND_RECOVERY;
 748
 749                if (conn->sess->sess_ops->DataPDUInOrder)
 750                        return 0;
 751
 752                for (i = 0; i < seq->pdu_count; i++) {
 753                        pdu = &cmd->pdu_list[i+seq->pdu_start];
 754
 755                        if (pdu->status != ISCSI_PDU_RECEIVED_OK)
 756                                continue;
 757
 758                        pdu->status = ISCSI_PDU_NOT_RECEIVED;
 759                }
 760        }
 761
 762        return 0;
 763}
 764
 765int iscsit_recover_dataout_sequence(
 766        struct iscsi_cmd *cmd,
 767        u32 pdu_offset,
 768        u32 pdu_length)
 769{
 770        u32 r2t_length = 0, r2t_offset = 0;
 771
 772        spin_lock_bh(&cmd->istate_lock);
 773        cmd->cmd_flags |= ICF_WITHIN_COMMAND_RECOVERY;
 774        spin_unlock_bh(&cmd->istate_lock);
 775
 776        if (iscsit_recalculate_dataout_values(cmd, pdu_offset, pdu_length,
 777                        &r2t_offset, &r2t_length) < 0)
 778                return DATAOUT_CANNOT_RECOVER;
 779
 780        iscsit_send_recovery_r2t(cmd, r2t_offset, r2t_length);
 781
 782        return DATAOUT_WITHIN_COMMAND_RECOVERY;
 783}
 784
 785static struct iscsi_ooo_cmdsn *iscsit_allocate_ooo_cmdsn(void)
 786{
 787        struct iscsi_ooo_cmdsn *ooo_cmdsn = NULL;
 788
 789        ooo_cmdsn = kmem_cache_zalloc(lio_ooo_cache, GFP_ATOMIC);
 790        if (!ooo_cmdsn) {
 791                pr_err("Unable to allocate memory for"
 792                        " struct iscsi_ooo_cmdsn.\n");
 793                return NULL;
 794        }
 795        INIT_LIST_HEAD(&ooo_cmdsn->ooo_list);
 796
 797        return ooo_cmdsn;
 798}
 799
 800/*
 801 *      Called with sess->cmdsn_mutex held.
 802 */
 803static int iscsit_attach_ooo_cmdsn(
 804        struct iscsi_session *sess,
 805        struct iscsi_ooo_cmdsn *ooo_cmdsn)
 806{
 807        struct iscsi_ooo_cmdsn *ooo_tail, *ooo_tmp;
 808        /*
 809         * We attach the struct iscsi_ooo_cmdsn entry to the out of order
 810         * list in increasing CmdSN order.
 811         * This allows iscsi_execute_ooo_cmdsns() to detect any
 812         * additional CmdSN holes while performing delayed execution.
 813         */
 814        if (list_empty(&sess->sess_ooo_cmdsn_list))
 815                list_add_tail(&ooo_cmdsn->ooo_list,
 816                                &sess->sess_ooo_cmdsn_list);
 817        else {
 818                ooo_tail = list_entry(sess->sess_ooo_cmdsn_list.prev,
 819                                typeof(*ooo_tail), ooo_list);
 820                /*
 821                 * CmdSN is greater than the tail of the list.
 822                 */
 823                if (iscsi_sna_lt(ooo_tail->cmdsn, ooo_cmdsn->cmdsn))
 824                        list_add_tail(&ooo_cmdsn->ooo_list,
 825                                        &sess->sess_ooo_cmdsn_list);
 826                else {
 827                        /*
 828                         * CmdSN is either lower than the head,  or somewhere
 829                         * in the middle.
 830                         */
 831                        list_for_each_entry(ooo_tmp, &sess->sess_ooo_cmdsn_list,
 832                                                ooo_list) {
 833                                if (iscsi_sna_lt(ooo_tmp->cmdsn, ooo_cmdsn->cmdsn))
 834                                        continue;
 835
 836                                /* Insert before this entry */
 837                                list_add(&ooo_cmdsn->ooo_list,
 838                                        ooo_tmp->ooo_list.prev);
 839                                break;
 840                        }
 841                }
 842        }
 843
 844        return 0;
 845}
 846
 847/*
 848 *      Removes an struct iscsi_ooo_cmdsn from a session's list,
 849 *      called with struct iscsi_session->cmdsn_mutex held.
 850 */
 851void iscsit_remove_ooo_cmdsn(
 852        struct iscsi_session *sess,
 853        struct iscsi_ooo_cmdsn *ooo_cmdsn)
 854{
 855        list_del(&ooo_cmdsn->ooo_list);
 856        kmem_cache_free(lio_ooo_cache, ooo_cmdsn);
 857}
 858
 859void iscsit_clear_ooo_cmdsns_for_conn(struct iscsi_conn *conn)
 860{
 861        struct iscsi_ooo_cmdsn *ooo_cmdsn;
 862        struct iscsi_session *sess = conn->sess;
 863
 864        mutex_lock(&sess->cmdsn_mutex);
 865        list_for_each_entry(ooo_cmdsn, &sess->sess_ooo_cmdsn_list, ooo_list) {
 866                if (ooo_cmdsn->cid != conn->cid)
 867                        continue;
 868
 869                ooo_cmdsn->cmd = NULL;
 870        }
 871        mutex_unlock(&sess->cmdsn_mutex);
 872}
 873
 874/*
 875 *      Called with sess->cmdsn_mutex held.
 876 */
 877int iscsit_execute_ooo_cmdsns(struct iscsi_session *sess)
 878{
 879        int ooo_count = 0;
 880        struct iscsi_cmd *cmd = NULL;
 881        struct iscsi_ooo_cmdsn *ooo_cmdsn, *ooo_cmdsn_tmp;
 882
 883        list_for_each_entry_safe(ooo_cmdsn, ooo_cmdsn_tmp,
 884                                &sess->sess_ooo_cmdsn_list, ooo_list) {
 885                if (ooo_cmdsn->cmdsn != sess->exp_cmd_sn)
 886                        continue;
 887
 888                if (!ooo_cmdsn->cmd) {
 889                        sess->exp_cmd_sn++;
 890                        iscsit_remove_ooo_cmdsn(sess, ooo_cmdsn);
 891                        continue;
 892                }
 893
 894                cmd = ooo_cmdsn->cmd;
 895                cmd->i_state = cmd->deferred_i_state;
 896                ooo_count++;
 897                sess->exp_cmd_sn++;
 898                pr_debug("Executing out of order CmdSN: 0x%08x,"
 899                        " incremented ExpCmdSN to 0x%08x.\n",
 900                        cmd->cmd_sn, sess->exp_cmd_sn);
 901
 902                iscsit_remove_ooo_cmdsn(sess, ooo_cmdsn);
 903
 904                if (iscsit_execute_cmd(cmd, 1) < 0)
 905                        return -1;
 906
 907                continue;
 908        }
 909
 910        return ooo_count;
 911}
 912
 913/*
 914 *      Called either:
 915 *
 916 *      1. With sess->cmdsn_mutex held from iscsi_execute_ooo_cmdsns()
 917 *      or iscsi_check_received_cmdsn().
 918 *      2. With no locks held directly from iscsi_handle_XXX_pdu() functions
 919 *      for immediate commands.
 920 */
 921int iscsit_execute_cmd(struct iscsi_cmd *cmd, int ooo)
 922{
 923        struct se_cmd *se_cmd = &cmd->se_cmd;
 924        struct iscsi_conn *conn = cmd->conn;
 925        int lr = 0;
 926
 927        spin_lock_bh(&cmd->istate_lock);
 928        if (ooo)
 929                cmd->cmd_flags &= ~ICF_OOO_CMDSN;
 930
 931        switch (cmd->iscsi_opcode) {
 932        case ISCSI_OP_SCSI_CMD:
 933                /*
 934                 * Go ahead and send the CHECK_CONDITION status for
 935                 * any SCSI CDB exceptions that may have occurred.
 936                 */
 937                if (cmd->sense_reason) {
 938                        if (cmd->sense_reason == TCM_RESERVATION_CONFLICT) {
 939                                cmd->i_state = ISTATE_SEND_STATUS;
 940                                spin_unlock_bh(&cmd->istate_lock);
 941                                iscsit_add_cmd_to_response_queue(cmd, cmd->conn,
 942                                                cmd->i_state);
 943                                return 0;
 944                        }
 945                        spin_unlock_bh(&cmd->istate_lock);
 946                        /*
 947                         * Determine if delayed TASK_ABORTED status for WRITEs
 948                         * should be sent now if no unsolicited data out
 949                         * payloads are expected, or if the delayed status
 950                         * should be sent after unsolicited data out with
 951                         * ISCSI_FLAG_CMD_FINAL set in iscsi_handle_data_out()
 952                         */
 953                        if (transport_check_aborted_status(se_cmd,
 954                                        (cmd->unsolicited_data == 0)) != 0)
 955                                return 0;
 956                        /*
 957                         * Otherwise send CHECK_CONDITION and sense for
 958                         * exception
 959                         */
 960                        return transport_send_check_condition_and_sense(se_cmd,
 961                                        cmd->sense_reason, 0);
 962                }
 963                /*
 964                 * Special case for delayed CmdSN with Immediate
 965                 * Data and/or Unsolicited Data Out attached.
 966                 */
 967                if (cmd->immediate_data) {
 968                        if (cmd->cmd_flags & ICF_GOT_LAST_DATAOUT) {
 969                                spin_unlock_bh(&cmd->istate_lock);
 970                                target_execute_cmd(&cmd->se_cmd);
 971                                return 0;
 972                        }
 973                        spin_unlock_bh(&cmd->istate_lock);
 974
 975                        if (!(cmd->cmd_flags &
 976                                        ICF_NON_IMMEDIATE_UNSOLICITED_DATA)) {
 977                                /*
 978                                 * Send the delayed TASK_ABORTED status for
 979                                 * WRITEs if no more unsolicitied data is
 980                                 * expected.
 981                                 */
 982                                if (transport_check_aborted_status(se_cmd, 1)
 983                                                != 0)
 984                                        return 0;
 985
 986                                iscsit_set_dataout_sequence_values(cmd);
 987                                conn->conn_transport->iscsit_get_dataout(conn, cmd, false);
 988                        }
 989                        return 0;
 990                }
 991                /*
 992                 * The default handler.
 993                 */
 994                spin_unlock_bh(&cmd->istate_lock);
 995
 996                if ((cmd->data_direction == DMA_TO_DEVICE) &&
 997                    !(cmd->cmd_flags & ICF_NON_IMMEDIATE_UNSOLICITED_DATA)) {
 998                        /*
 999                         * Send the delayed TASK_ABORTED status for WRITEs if
1000                         * no more nsolicitied data is expected.
1001                         */
1002                        if (transport_check_aborted_status(se_cmd, 1) != 0)
1003                                return 0;
1004
1005                        iscsit_set_unsoliticed_dataout(cmd);
1006                }
1007                return transport_handle_cdb_direct(&cmd->se_cmd);
1008
1009        case ISCSI_OP_NOOP_OUT:
1010        case ISCSI_OP_TEXT:
1011                spin_unlock_bh(&cmd->istate_lock);
1012                iscsit_add_cmd_to_response_queue(cmd, cmd->conn, cmd->i_state);
1013                break;
1014        case ISCSI_OP_SCSI_TMFUNC:
1015                if (cmd->se_cmd.se_tmr_req->response) {
1016                        spin_unlock_bh(&cmd->istate_lock);
1017                        iscsit_add_cmd_to_response_queue(cmd, cmd->conn,
1018                                        cmd->i_state);
1019                        return 0;
1020                }
1021                spin_unlock_bh(&cmd->istate_lock);
1022
1023                return transport_generic_handle_tmr(&cmd->se_cmd);
1024        case ISCSI_OP_LOGOUT:
1025                spin_unlock_bh(&cmd->istate_lock);
1026                switch (cmd->logout_reason) {
1027                case ISCSI_LOGOUT_REASON_CLOSE_SESSION:
1028                        lr = iscsit_logout_closesession(cmd, cmd->conn);
1029                        break;
1030                case ISCSI_LOGOUT_REASON_CLOSE_CONNECTION:
1031                        lr = iscsit_logout_closeconnection(cmd, cmd->conn);
1032                        break;
1033                case ISCSI_LOGOUT_REASON_RECOVERY:
1034                        lr = iscsit_logout_removeconnforrecovery(cmd, cmd->conn);
1035                        break;
1036                default:
1037                        pr_err("Unknown iSCSI Logout Request Code:"
1038                                " 0x%02x\n", cmd->logout_reason);
1039                        return -1;
1040                }
1041
1042                return lr;
1043        default:
1044                spin_unlock_bh(&cmd->istate_lock);
1045                pr_err("Cannot perform out of order execution for"
1046                " unknown iSCSI Opcode: 0x%02x\n", cmd->iscsi_opcode);
1047                return -1;
1048        }
1049
1050        return 0;
1051}
1052
1053void iscsit_free_all_ooo_cmdsns(struct iscsi_session *sess)
1054{
1055        struct iscsi_ooo_cmdsn *ooo_cmdsn, *ooo_cmdsn_tmp;
1056
1057        mutex_lock(&sess->cmdsn_mutex);
1058        list_for_each_entry_safe(ooo_cmdsn, ooo_cmdsn_tmp,
1059                        &sess->sess_ooo_cmdsn_list, ooo_list) {
1060
1061                list_del(&ooo_cmdsn->ooo_list);
1062                kmem_cache_free(lio_ooo_cache, ooo_cmdsn);
1063        }
1064        mutex_unlock(&sess->cmdsn_mutex);
1065}
1066
1067int iscsit_handle_ooo_cmdsn(
1068        struct iscsi_session *sess,
1069        struct iscsi_cmd *cmd,
1070        u32 cmdsn)
1071{
1072        int batch = 0;
1073        struct iscsi_ooo_cmdsn *ooo_cmdsn = NULL, *ooo_tail = NULL;
1074
1075        cmd->deferred_i_state           = cmd->i_state;
1076        cmd->i_state                    = ISTATE_DEFERRED_CMD;
1077        cmd->cmd_flags                  |= ICF_OOO_CMDSN;
1078
1079        if (list_empty(&sess->sess_ooo_cmdsn_list))
1080                batch = 1;
1081        else {
1082                ooo_tail = list_entry(sess->sess_ooo_cmdsn_list.prev,
1083                                typeof(*ooo_tail), ooo_list);
1084                if (ooo_tail->cmdsn != (cmdsn - 1))
1085                        batch = 1;
1086        }
1087
1088        ooo_cmdsn = iscsit_allocate_ooo_cmdsn();
1089        if (!ooo_cmdsn)
1090                return -ENOMEM;
1091
1092        ooo_cmdsn->cmd                  = cmd;
1093        ooo_cmdsn->batch_count          = (batch) ?
1094                                          (cmdsn - sess->exp_cmd_sn) : 1;
1095        ooo_cmdsn->cid                  = cmd->conn->cid;
1096        ooo_cmdsn->exp_cmdsn            = sess->exp_cmd_sn;
1097        ooo_cmdsn->cmdsn                = cmdsn;
1098
1099        if (iscsit_attach_ooo_cmdsn(sess, ooo_cmdsn) < 0) {
1100                kmem_cache_free(lio_ooo_cache, ooo_cmdsn);
1101                return -ENOMEM;
1102        }
1103
1104        return 0;
1105}
1106
1107static int iscsit_set_dataout_timeout_values(
1108        struct iscsi_cmd *cmd,
1109        u32 *offset,
1110        u32 *length)
1111{
1112        struct iscsi_conn *conn = cmd->conn;
1113        struct iscsi_r2t *r2t;
1114
1115        if (cmd->unsolicited_data) {
1116                *offset = 0;
1117                *length = (conn->sess->sess_ops->FirstBurstLength >
1118                           cmd->se_cmd.data_length) ?
1119                           cmd->se_cmd.data_length :
1120                           conn->sess->sess_ops->FirstBurstLength;
1121                return 0;
1122        }
1123
1124        spin_lock_bh(&cmd->r2t_lock);
1125        if (list_empty(&cmd->cmd_r2t_list)) {
1126                pr_err("cmd->cmd_r2t_list is empty!\n");
1127                spin_unlock_bh(&cmd->r2t_lock);
1128                return -1;
1129        }
1130
1131        list_for_each_entry(r2t, &cmd->cmd_r2t_list, r2t_list) {
1132                if (r2t->sent_r2t && !r2t->recovery_r2t && !r2t->seq_complete) {
1133                        *offset = r2t->offset;
1134                        *length = r2t->xfer_len;
1135                        spin_unlock_bh(&cmd->r2t_lock);
1136                        return 0;
1137                }
1138        }
1139        spin_unlock_bh(&cmd->r2t_lock);
1140
1141        pr_err("Unable to locate any incomplete DataOUT"
1142                " sequences for ITT: 0x%08x.\n", cmd->init_task_tag);
1143
1144        return -1;
1145}
1146
1147/*
1148 *      NOTE: Called from interrupt (timer) context.
1149 */
1150void iscsit_handle_dataout_timeout(struct timer_list *t)
1151{
1152        u32 pdu_length = 0, pdu_offset = 0;
1153        u32 r2t_length = 0, r2t_offset = 0;
1154        struct iscsi_cmd *cmd = from_timer(cmd, t, dataout_timer);
1155        struct iscsi_conn *conn = cmd->conn;
1156        struct iscsi_session *sess = NULL;
1157        struct iscsi_node_attrib *na;
1158
1159        iscsit_inc_conn_usage_count(conn);
1160
1161        spin_lock_bh(&cmd->dataout_timeout_lock);
1162        if (cmd->dataout_timer_flags & ISCSI_TF_STOP) {
1163                spin_unlock_bh(&cmd->dataout_timeout_lock);
1164                iscsit_dec_conn_usage_count(conn);
1165                return;
1166        }
1167        cmd->dataout_timer_flags &= ~ISCSI_TF_RUNNING;
1168        sess = conn->sess;
1169        na = iscsit_tpg_get_node_attrib(sess);
1170
1171        if (!sess->sess_ops->ErrorRecoveryLevel) {
1172                pr_debug("Unable to recover from DataOut timeout while"
1173                        " in ERL=0.\n");
1174                goto failure;
1175        }
1176
1177        if (++cmd->dataout_timeout_retries == na->dataout_timeout_retries) {
1178                pr_debug("Command ITT: 0x%08x exceeded max retries"
1179                        " for DataOUT timeout %u, closing iSCSI connection.\n",
1180                        cmd->init_task_tag, na->dataout_timeout_retries);
1181                goto failure;
1182        }
1183
1184        cmd->cmd_flags |= ICF_WITHIN_COMMAND_RECOVERY;
1185
1186        if (conn->sess->sess_ops->DataSequenceInOrder) {
1187                if (conn->sess->sess_ops->DataPDUInOrder) {
1188                        pdu_offset = cmd->write_data_done;
1189                        if ((pdu_offset + (conn->sess->sess_ops->MaxBurstLength -
1190                             cmd->next_burst_len)) > cmd->se_cmd.data_length)
1191                                pdu_length = (cmd->se_cmd.data_length -
1192                                        cmd->write_data_done);
1193                        else
1194                                pdu_length = (conn->sess->sess_ops->MaxBurstLength -
1195                                                cmd->next_burst_len);
1196                } else {
1197                        pdu_offset = cmd->seq_start_offset;
1198                        pdu_length = (cmd->seq_end_offset -
1199                                cmd->seq_start_offset);
1200                }
1201        } else {
1202                if (iscsit_set_dataout_timeout_values(cmd, &pdu_offset,
1203                                &pdu_length) < 0)
1204                        goto failure;
1205        }
1206
1207        if (iscsit_recalculate_dataout_values(cmd, pdu_offset, pdu_length,
1208                        &r2t_offset, &r2t_length) < 0)
1209                goto failure;
1210
1211        pr_debug("Command ITT: 0x%08x timed out waiting for"
1212                " completion of %sDataOUT Sequence Offset: %u, Length: %u\n",
1213                cmd->init_task_tag, (cmd->unsolicited_data) ? "Unsolicited " :
1214                "", r2t_offset, r2t_length);
1215
1216        if (iscsit_send_recovery_r2t(cmd, r2t_offset, r2t_length) < 0)
1217                goto failure;
1218
1219        iscsit_start_dataout_timer(cmd, conn);
1220        spin_unlock_bh(&cmd->dataout_timeout_lock);
1221        iscsit_dec_conn_usage_count(conn);
1222
1223        return;
1224
1225failure:
1226        spin_unlock_bh(&cmd->dataout_timeout_lock);
1227        iscsit_cause_connection_reinstatement(conn, 0);
1228        iscsit_dec_conn_usage_count(conn);
1229}
1230
1231void iscsit_mod_dataout_timer(struct iscsi_cmd *cmd)
1232{
1233        struct iscsi_conn *conn = cmd->conn;
1234        struct iscsi_session *sess = conn->sess;
1235        struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
1236
1237        spin_lock_bh(&cmd->dataout_timeout_lock);
1238        if (!(cmd->dataout_timer_flags & ISCSI_TF_RUNNING)) {
1239                spin_unlock_bh(&cmd->dataout_timeout_lock);
1240                return;
1241        }
1242
1243        mod_timer(&cmd->dataout_timer,
1244                (get_jiffies_64() + na->dataout_timeout * HZ));
1245        pr_debug("Updated DataOUT timer for ITT: 0x%08x",
1246                        cmd->init_task_tag);
1247        spin_unlock_bh(&cmd->dataout_timeout_lock);
1248}
1249
1250/*
1251 *      Called with cmd->dataout_timeout_lock held.
1252 */
1253void iscsit_start_dataout_timer(
1254        struct iscsi_cmd *cmd,
1255        struct iscsi_conn *conn)
1256{
1257        struct iscsi_session *sess = conn->sess;
1258        struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
1259
1260        if (cmd->dataout_timer_flags & ISCSI_TF_RUNNING)
1261                return;
1262
1263        pr_debug("Starting DataOUT timer for ITT: 0x%08x on"
1264                " CID: %hu.\n", cmd->init_task_tag, conn->cid);
1265
1266        cmd->dataout_timer_flags &= ~ISCSI_TF_STOP;
1267        cmd->dataout_timer_flags |= ISCSI_TF_RUNNING;
1268        mod_timer(&cmd->dataout_timer, jiffies + na->dataout_timeout * HZ);
1269}
1270
1271void iscsit_stop_dataout_timer(struct iscsi_cmd *cmd)
1272{
1273        spin_lock_bh(&cmd->dataout_timeout_lock);
1274        if (!(cmd->dataout_timer_flags & ISCSI_TF_RUNNING)) {
1275                spin_unlock_bh(&cmd->dataout_timeout_lock);
1276                return;
1277        }
1278        cmd->dataout_timer_flags |= ISCSI_TF_STOP;
1279        spin_unlock_bh(&cmd->dataout_timeout_lock);
1280
1281        del_timer_sync(&cmd->dataout_timer);
1282
1283        spin_lock_bh(&cmd->dataout_timeout_lock);
1284        cmd->dataout_timer_flags &= ~ISCSI_TF_RUNNING;
1285        pr_debug("Stopped DataOUT Timer for ITT: 0x%08x\n",
1286                        cmd->init_task_tag);
1287        spin_unlock_bh(&cmd->dataout_timeout_lock);
1288}
1289EXPORT_SYMBOL(iscsit_stop_dataout_timer);
1290