linux/drivers/scsi/libiscsi.c
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   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * iSCSI lib functions
   4 *
   5 * Copyright (C) 2006 Red Hat, Inc.  All rights reserved.
   6 * Copyright (C) 2004 - 2006 Mike Christie
   7 * Copyright (C) 2004 - 2005 Dmitry Yusupov
   8 * Copyright (C) 2004 - 2005 Alex Aizman
   9 * maintained by open-iscsi@googlegroups.com
  10 */
  11#include <linux/types.h>
  12#include <linux/kfifo.h>
  13#include <linux/delay.h>
  14#include <linux/log2.h>
  15#include <linux/slab.h>
  16#include <linux/sched/signal.h>
  17#include <linux/module.h>
  18#include <asm/unaligned.h>
  19#include <net/tcp.h>
  20#include <scsi/scsi_cmnd.h>
  21#include <scsi/scsi_device.h>
  22#include <scsi/scsi_eh.h>
  23#include <scsi/scsi_tcq.h>
  24#include <scsi/scsi_host.h>
  25#include <scsi/scsi.h>
  26#include <scsi/iscsi_proto.h>
  27#include <scsi/scsi_transport.h>
  28#include <scsi/scsi_transport_iscsi.h>
  29#include <scsi/libiscsi.h>
  30#include <trace/events/iscsi.h>
  31
  32static int iscsi_dbg_lib_conn;
  33module_param_named(debug_libiscsi_conn, iscsi_dbg_lib_conn, int,
  34                   S_IRUGO | S_IWUSR);
  35MODULE_PARM_DESC(debug_libiscsi_conn,
  36                 "Turn on debugging for connections in libiscsi module. "
  37                 "Set to 1 to turn on, and zero to turn off. Default is off.");
  38
  39static int iscsi_dbg_lib_session;
  40module_param_named(debug_libiscsi_session, iscsi_dbg_lib_session, int,
  41                   S_IRUGO | S_IWUSR);
  42MODULE_PARM_DESC(debug_libiscsi_session,
  43                 "Turn on debugging for sessions in libiscsi module. "
  44                 "Set to 1 to turn on, and zero to turn off. Default is off.");
  45
  46static int iscsi_dbg_lib_eh;
  47module_param_named(debug_libiscsi_eh, iscsi_dbg_lib_eh, int,
  48                   S_IRUGO | S_IWUSR);
  49MODULE_PARM_DESC(debug_libiscsi_eh,
  50                 "Turn on debugging for error handling in libiscsi module. "
  51                 "Set to 1 to turn on, and zero to turn off. Default is off.");
  52
  53#define ISCSI_DBG_CONN(_conn, dbg_fmt, arg...)                  \
  54        do {                                                    \
  55                if (iscsi_dbg_lib_conn)                         \
  56                        iscsi_conn_printk(KERN_INFO, _conn,     \
  57                                             "%s " dbg_fmt,     \
  58                                             __func__, ##arg);  \
  59                iscsi_dbg_trace(trace_iscsi_dbg_conn,           \
  60                                &(_conn)->cls_conn->dev,        \
  61                                "%s " dbg_fmt, __func__, ##arg);\
  62        } while (0);
  63
  64#define ISCSI_DBG_SESSION(_session, dbg_fmt, arg...)                    \
  65        do {                                                            \
  66                if (iscsi_dbg_lib_session)                              \
  67                        iscsi_session_printk(KERN_INFO, _session,       \
  68                                             "%s " dbg_fmt,             \
  69                                             __func__, ##arg);          \
  70                iscsi_dbg_trace(trace_iscsi_dbg_session,                \
  71                                &(_session)->cls_session->dev,          \
  72                                "%s " dbg_fmt, __func__, ##arg);        \
  73        } while (0);
  74
  75#define ISCSI_DBG_EH(_session, dbg_fmt, arg...)                         \
  76        do {                                                            \
  77                if (iscsi_dbg_lib_eh)                                   \
  78                        iscsi_session_printk(KERN_INFO, _session,       \
  79                                             "%s " dbg_fmt,             \
  80                                             __func__, ##arg);          \
  81                iscsi_dbg_trace(trace_iscsi_dbg_eh,                     \
  82                                &(_session)->cls_session->dev,          \
  83                                "%s " dbg_fmt, __func__, ##arg);        \
  84        } while (0);
  85
  86inline void iscsi_conn_queue_work(struct iscsi_conn *conn)
  87{
  88        struct Scsi_Host *shost = conn->session->host;
  89        struct iscsi_host *ihost = shost_priv(shost);
  90
  91        if (ihost->workq)
  92                queue_work(ihost->workq, &conn->xmitwork);
  93}
  94EXPORT_SYMBOL_GPL(iscsi_conn_queue_work);
  95
  96static void __iscsi_update_cmdsn(struct iscsi_session *session,
  97                                 uint32_t exp_cmdsn, uint32_t max_cmdsn)
  98{
  99        /*
 100         * standard specifies this check for when to update expected and
 101         * max sequence numbers
 102         */
 103        if (iscsi_sna_lt(max_cmdsn, exp_cmdsn - 1))
 104                return;
 105
 106        if (exp_cmdsn != session->exp_cmdsn &&
 107            !iscsi_sna_lt(exp_cmdsn, session->exp_cmdsn))
 108                session->exp_cmdsn = exp_cmdsn;
 109
 110        if (max_cmdsn != session->max_cmdsn &&
 111            !iscsi_sna_lt(max_cmdsn, session->max_cmdsn))
 112                session->max_cmdsn = max_cmdsn;
 113}
 114
 115void iscsi_update_cmdsn(struct iscsi_session *session, struct iscsi_nopin *hdr)
 116{
 117        __iscsi_update_cmdsn(session, be32_to_cpu(hdr->exp_cmdsn),
 118                             be32_to_cpu(hdr->max_cmdsn));
 119}
 120EXPORT_SYMBOL_GPL(iscsi_update_cmdsn);
 121
 122/**
 123 * iscsi_prep_data_out_pdu - initialize Data-Out
 124 * @task: scsi command task
 125 * @r2t: R2T info
 126 * @hdr: iscsi data in pdu
 127 *
 128 * Notes:
 129 *      Initialize Data-Out within this R2T sequence and finds
 130 *      proper data_offset within this SCSI command.
 131 *
 132 *      This function is called with connection lock taken.
 133 **/
 134void iscsi_prep_data_out_pdu(struct iscsi_task *task, struct iscsi_r2t_info *r2t,
 135                           struct iscsi_data *hdr)
 136{
 137        struct iscsi_conn *conn = task->conn;
 138        unsigned int left = r2t->data_length - r2t->sent;
 139
 140        task->hdr_len = sizeof(struct iscsi_data);
 141
 142        memset(hdr, 0, sizeof(struct iscsi_data));
 143        hdr->ttt = r2t->ttt;
 144        hdr->datasn = cpu_to_be32(r2t->datasn);
 145        r2t->datasn++;
 146        hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
 147        hdr->lun = task->lun;
 148        hdr->itt = task->hdr_itt;
 149        hdr->exp_statsn = r2t->exp_statsn;
 150        hdr->offset = cpu_to_be32(r2t->data_offset + r2t->sent);
 151        if (left > conn->max_xmit_dlength) {
 152                hton24(hdr->dlength, conn->max_xmit_dlength);
 153                r2t->data_count = conn->max_xmit_dlength;
 154                hdr->flags = 0;
 155        } else {
 156                hton24(hdr->dlength, left);
 157                r2t->data_count = left;
 158                hdr->flags = ISCSI_FLAG_CMD_FINAL;
 159        }
 160        conn->dataout_pdus_cnt++;
 161}
 162EXPORT_SYMBOL_GPL(iscsi_prep_data_out_pdu);
 163
 164static int iscsi_add_hdr(struct iscsi_task *task, unsigned len)
 165{
 166        unsigned exp_len = task->hdr_len + len;
 167
 168        if (exp_len > task->hdr_max) {
 169                WARN_ON(1);
 170                return -EINVAL;
 171        }
 172
 173        WARN_ON(len & (ISCSI_PAD_LEN - 1)); /* caller must pad the AHS */
 174        task->hdr_len = exp_len;
 175        return 0;
 176}
 177
 178/*
 179 * make an extended cdb AHS
 180 */
 181static int iscsi_prep_ecdb_ahs(struct iscsi_task *task)
 182{
 183        struct scsi_cmnd *cmd = task->sc;
 184        unsigned rlen, pad_len;
 185        unsigned short ahslength;
 186        struct iscsi_ecdb_ahdr *ecdb_ahdr;
 187        int rc;
 188
 189        ecdb_ahdr = iscsi_next_hdr(task);
 190        rlen = cmd->cmd_len - ISCSI_CDB_SIZE;
 191
 192        BUG_ON(rlen > sizeof(ecdb_ahdr->ecdb));
 193        ahslength = rlen + sizeof(ecdb_ahdr->reserved);
 194
 195        pad_len = iscsi_padding(rlen);
 196
 197        rc = iscsi_add_hdr(task, sizeof(ecdb_ahdr->ahslength) +
 198                           sizeof(ecdb_ahdr->ahstype) + ahslength + pad_len);
 199        if (rc)
 200                return rc;
 201
 202        if (pad_len)
 203                memset(&ecdb_ahdr->ecdb[rlen], 0, pad_len);
 204
 205        ecdb_ahdr->ahslength = cpu_to_be16(ahslength);
 206        ecdb_ahdr->ahstype = ISCSI_AHSTYPE_CDB;
 207        ecdb_ahdr->reserved = 0;
 208        memcpy(ecdb_ahdr->ecdb, cmd->cmnd + ISCSI_CDB_SIZE, rlen);
 209
 210        ISCSI_DBG_SESSION(task->conn->session,
 211                          "iscsi_prep_ecdb_ahs: varlen_cdb_len %d "
 212                          "rlen %d pad_len %d ahs_length %d iscsi_headers_size "
 213                          "%u\n", cmd->cmd_len, rlen, pad_len, ahslength,
 214                          task->hdr_len);
 215        return 0;
 216}
 217
 218/**
 219 * iscsi_check_tmf_restrictions - check if a task is affected by TMF
 220 * @task: iscsi task
 221 * @opcode: opcode to check for
 222 *
 223 * During TMF a task has to be checked if it's affected.
 224 * All unrelated I/O can be passed through, but I/O to the
 225 * affected LUN should be restricted.
 226 * If 'fast_abort' is set we won't be sending any I/O to the
 227 * affected LUN.
 228 * Otherwise the target is waiting for all TTTs to be completed,
 229 * so we have to send all outstanding Data-Out PDUs to the target.
 230 */
 231static int iscsi_check_tmf_restrictions(struct iscsi_task *task, int opcode)
 232{
 233        struct iscsi_conn *conn = task->conn;
 234        struct iscsi_tm *tmf = &conn->tmhdr;
 235        u64 hdr_lun;
 236
 237        if (conn->tmf_state == TMF_INITIAL)
 238                return 0;
 239
 240        if ((tmf->opcode & ISCSI_OPCODE_MASK) != ISCSI_OP_SCSI_TMFUNC)
 241                return 0;
 242
 243        switch (ISCSI_TM_FUNC_VALUE(tmf)) {
 244        case ISCSI_TM_FUNC_LOGICAL_UNIT_RESET:
 245                /*
 246                 * Allow PDUs for unrelated LUNs
 247                 */
 248                hdr_lun = scsilun_to_int(&tmf->lun);
 249                if (hdr_lun != task->sc->device->lun)
 250                        return 0;
 251                /* fall through */
 252        case ISCSI_TM_FUNC_TARGET_WARM_RESET:
 253                /*
 254                 * Fail all SCSI cmd PDUs
 255                 */
 256                if (opcode != ISCSI_OP_SCSI_DATA_OUT) {
 257                        iscsi_conn_printk(KERN_INFO, conn,
 258                                          "task [op %x itt "
 259                                          "0x%x/0x%x] "
 260                                          "rejected.\n",
 261                                          opcode, task->itt,
 262                                          task->hdr_itt);
 263                        return -EACCES;
 264                }
 265                /*
 266                 * And also all data-out PDUs in response to R2T
 267                 * if fast_abort is set.
 268                 */
 269                if (conn->session->fast_abort) {
 270                        iscsi_conn_printk(KERN_INFO, conn,
 271                                          "task [op %x itt "
 272                                          "0x%x/0x%x] fast abort.\n",
 273                                          opcode, task->itt,
 274                                          task->hdr_itt);
 275                        return -EACCES;
 276                }
 277                break;
 278        case ISCSI_TM_FUNC_ABORT_TASK:
 279                /*
 280                 * the caller has already checked if the task
 281                 * they want to abort was in the pending queue so if
 282                 * we are here the cmd pdu has gone out already, and
 283                 * we will only hit this for data-outs
 284                 */
 285                if (opcode == ISCSI_OP_SCSI_DATA_OUT &&
 286                    task->hdr_itt == tmf->rtt) {
 287                        ISCSI_DBG_SESSION(conn->session,
 288                                          "Preventing task %x/%x from sending "
 289                                          "data-out due to abort task in "
 290                                          "progress\n", task->itt,
 291                                          task->hdr_itt);
 292                        return -EACCES;
 293                }
 294                break;
 295        }
 296
 297        return 0;
 298}
 299
 300/**
 301 * iscsi_prep_scsi_cmd_pdu - prep iscsi scsi cmd pdu
 302 * @task: iscsi task
 303 *
 304 * Prep basic iSCSI PDU fields for a scsi cmd pdu. The LLD should set
 305 * fields like dlength or final based on how much data it sends
 306 */
 307static int iscsi_prep_scsi_cmd_pdu(struct iscsi_task *task)
 308{
 309        struct iscsi_conn *conn = task->conn;
 310        struct iscsi_session *session = conn->session;
 311        struct scsi_cmnd *sc = task->sc;
 312        struct iscsi_scsi_req *hdr;
 313        unsigned hdrlength, cmd_len, transfer_length;
 314        itt_t itt;
 315        int rc;
 316
 317        rc = iscsi_check_tmf_restrictions(task, ISCSI_OP_SCSI_CMD);
 318        if (rc)
 319                return rc;
 320
 321        if (conn->session->tt->alloc_pdu) {
 322                rc = conn->session->tt->alloc_pdu(task, ISCSI_OP_SCSI_CMD);
 323                if (rc)
 324                        return rc;
 325        }
 326        hdr = (struct iscsi_scsi_req *)task->hdr;
 327        itt = hdr->itt;
 328        memset(hdr, 0, sizeof(*hdr));
 329
 330        if (session->tt->parse_pdu_itt)
 331                hdr->itt = task->hdr_itt = itt;
 332        else
 333                hdr->itt = task->hdr_itt = build_itt(task->itt,
 334                                                     task->conn->session->age);
 335        task->hdr_len = 0;
 336        rc = iscsi_add_hdr(task, sizeof(*hdr));
 337        if (rc)
 338                return rc;
 339        hdr->opcode = ISCSI_OP_SCSI_CMD;
 340        hdr->flags = ISCSI_ATTR_SIMPLE;
 341        int_to_scsilun(sc->device->lun, &hdr->lun);
 342        task->lun = hdr->lun;
 343        hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
 344        cmd_len = sc->cmd_len;
 345        if (cmd_len < ISCSI_CDB_SIZE)
 346                memset(&hdr->cdb[cmd_len], 0, ISCSI_CDB_SIZE - cmd_len);
 347        else if (cmd_len > ISCSI_CDB_SIZE) {
 348                rc = iscsi_prep_ecdb_ahs(task);
 349                if (rc)
 350                        return rc;
 351                cmd_len = ISCSI_CDB_SIZE;
 352        }
 353        memcpy(hdr->cdb, sc->cmnd, cmd_len);
 354
 355        task->imm_count = 0;
 356        if (scsi_get_prot_op(sc) != SCSI_PROT_NORMAL)
 357                task->protected = true;
 358
 359        transfer_length = scsi_transfer_length(sc);
 360        hdr->data_length = cpu_to_be32(transfer_length);
 361        if (sc->sc_data_direction == DMA_TO_DEVICE) {
 362                struct iscsi_r2t_info *r2t = &task->unsol_r2t;
 363
 364                hdr->flags |= ISCSI_FLAG_CMD_WRITE;
 365                /*
 366                 * Write counters:
 367                 *
 368                 *      imm_count       bytes to be sent right after
 369                 *                      SCSI PDU Header
 370                 *
 371                 *      unsol_count     bytes(as Data-Out) to be sent
 372                 *                      without R2T ack right after
 373                 *                      immediate data
 374                 *
 375                 *      r2t data_length bytes to be sent via R2T ack's
 376                 *
 377                 *      pad_count       bytes to be sent as zero-padding
 378                 */
 379                memset(r2t, 0, sizeof(*r2t));
 380
 381                if (session->imm_data_en) {
 382                        if (transfer_length >= session->first_burst)
 383                                task->imm_count = min(session->first_burst,
 384                                                        conn->max_xmit_dlength);
 385                        else
 386                                task->imm_count = min(transfer_length,
 387                                                      conn->max_xmit_dlength);
 388                        hton24(hdr->dlength, task->imm_count);
 389                } else
 390                        zero_data(hdr->dlength);
 391
 392                if (!session->initial_r2t_en) {
 393                        r2t->data_length = min(session->first_burst,
 394                                               transfer_length) -
 395                                               task->imm_count;
 396                        r2t->data_offset = task->imm_count;
 397                        r2t->ttt = cpu_to_be32(ISCSI_RESERVED_TAG);
 398                        r2t->exp_statsn = cpu_to_be32(conn->exp_statsn);
 399                }
 400
 401                if (!task->unsol_r2t.data_length)
 402                        /* No unsolicit Data-Out's */
 403                        hdr->flags |= ISCSI_FLAG_CMD_FINAL;
 404        } else {
 405                hdr->flags |= ISCSI_FLAG_CMD_FINAL;
 406                zero_data(hdr->dlength);
 407
 408                if (sc->sc_data_direction == DMA_FROM_DEVICE)
 409                        hdr->flags |= ISCSI_FLAG_CMD_READ;
 410        }
 411
 412        /* calculate size of additional header segments (AHSs) */
 413        hdrlength = task->hdr_len - sizeof(*hdr);
 414
 415        WARN_ON(hdrlength & (ISCSI_PAD_LEN-1));
 416        hdrlength /= ISCSI_PAD_LEN;
 417
 418        WARN_ON(hdrlength >= 256);
 419        hdr->hlength = hdrlength & 0xFF;
 420        hdr->cmdsn = task->cmdsn = cpu_to_be32(session->cmdsn);
 421
 422        if (session->tt->init_task && session->tt->init_task(task))
 423                return -EIO;
 424
 425        task->state = ISCSI_TASK_RUNNING;
 426        session->cmdsn++;
 427
 428        conn->scsicmd_pdus_cnt++;
 429        ISCSI_DBG_SESSION(session, "iscsi prep [%s cid %d sc %p cdb 0x%x "
 430                          "itt 0x%x len %d cmdsn %d win %d]\n",
 431                          sc->sc_data_direction == DMA_TO_DEVICE ?
 432                          "write" : "read", conn->id, sc, sc->cmnd[0],
 433                          task->itt, transfer_length,
 434                          session->cmdsn,
 435                          session->max_cmdsn - session->exp_cmdsn + 1);
 436        return 0;
 437}
 438
 439/**
 440 * iscsi_free_task - free a task
 441 * @task: iscsi cmd task
 442 *
 443 * Must be called with session back_lock.
 444 * This function returns the scsi command to scsi-ml or cleans
 445 * up mgmt tasks then returns the task to the pool.
 446 */
 447static void iscsi_free_task(struct iscsi_task *task)
 448{
 449        struct iscsi_conn *conn = task->conn;
 450        struct iscsi_session *session = conn->session;
 451        struct scsi_cmnd *sc = task->sc;
 452        int oldstate = task->state;
 453
 454        ISCSI_DBG_SESSION(session, "freeing task itt 0x%x state %d sc %p\n",
 455                          task->itt, task->state, task->sc);
 456
 457        session->tt->cleanup_task(task);
 458        task->state = ISCSI_TASK_FREE;
 459        task->sc = NULL;
 460        /*
 461         * login task is preallocated so do not free
 462         */
 463        if (conn->login_task == task)
 464                return;
 465
 466        kfifo_in(&session->cmdpool.queue, (void*)&task, sizeof(void*));
 467
 468        if (sc) {
 469                /* SCSI eh reuses commands to verify us */
 470                sc->SCp.ptr = NULL;
 471                /*
 472                 * queue command may call this to free the task, so
 473                 * it will decide how to return sc to scsi-ml.
 474                 */
 475                if (oldstate != ISCSI_TASK_REQUEUE_SCSIQ)
 476                        sc->scsi_done(sc);
 477        }
 478}
 479
 480void __iscsi_get_task(struct iscsi_task *task)
 481{
 482        refcount_inc(&task->refcount);
 483}
 484EXPORT_SYMBOL_GPL(__iscsi_get_task);
 485
 486void __iscsi_put_task(struct iscsi_task *task)
 487{
 488        if (refcount_dec_and_test(&task->refcount))
 489                iscsi_free_task(task);
 490}
 491EXPORT_SYMBOL_GPL(__iscsi_put_task);
 492
 493void iscsi_put_task(struct iscsi_task *task)
 494{
 495        struct iscsi_session *session = task->conn->session;
 496
 497        /* regular RX path uses back_lock */
 498        spin_lock_bh(&session->back_lock);
 499        __iscsi_put_task(task);
 500        spin_unlock_bh(&session->back_lock);
 501}
 502EXPORT_SYMBOL_GPL(iscsi_put_task);
 503
 504/**
 505 * iscsi_complete_task - finish a task
 506 * @task: iscsi cmd task
 507 * @state: state to complete task with
 508 *
 509 * Must be called with session back_lock.
 510 */
 511static void iscsi_complete_task(struct iscsi_task *task, int state)
 512{
 513        struct iscsi_conn *conn = task->conn;
 514
 515        ISCSI_DBG_SESSION(conn->session,
 516                          "complete task itt 0x%x state %d sc %p\n",
 517                          task->itt, task->state, task->sc);
 518        if (task->state == ISCSI_TASK_COMPLETED ||
 519            task->state == ISCSI_TASK_ABRT_TMF ||
 520            task->state == ISCSI_TASK_ABRT_SESS_RECOV ||
 521            task->state == ISCSI_TASK_REQUEUE_SCSIQ)
 522                return;
 523        WARN_ON_ONCE(task->state == ISCSI_TASK_FREE);
 524        task->state = state;
 525
 526        spin_lock_bh(&conn->taskqueuelock);
 527        if (!list_empty(&task->running)) {
 528                pr_debug_once("%s while task on list", __func__);
 529                list_del_init(&task->running);
 530        }
 531        spin_unlock_bh(&conn->taskqueuelock);
 532
 533        if (conn->task == task)
 534                conn->task = NULL;
 535
 536        if (conn->ping_task == task)
 537                conn->ping_task = NULL;
 538
 539        /* release get from queueing */
 540        __iscsi_put_task(task);
 541}
 542
 543/**
 544 * iscsi_complete_scsi_task - finish scsi task normally
 545 * @task: iscsi task for scsi cmd
 546 * @exp_cmdsn: expected cmd sn in cpu format
 547 * @max_cmdsn: max cmd sn in cpu format
 548 *
 549 * This is used when drivers do not need or cannot perform
 550 * lower level pdu processing.
 551 *
 552 * Called with session back_lock
 553 */
 554void iscsi_complete_scsi_task(struct iscsi_task *task,
 555                              uint32_t exp_cmdsn, uint32_t max_cmdsn)
 556{
 557        struct iscsi_conn *conn = task->conn;
 558
 559        ISCSI_DBG_SESSION(conn->session, "[itt 0x%x]\n", task->itt);
 560
 561        conn->last_recv = jiffies;
 562        __iscsi_update_cmdsn(conn->session, exp_cmdsn, max_cmdsn);
 563        iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 564}
 565EXPORT_SYMBOL_GPL(iscsi_complete_scsi_task);
 566
 567
 568/*
 569 * session back_lock must be held and if not called for a task that is
 570 * still pending or from the xmit thread, then xmit thread must
 571 * be suspended.
 572 */
 573static void fail_scsi_task(struct iscsi_task *task, int err)
 574{
 575        struct iscsi_conn *conn = task->conn;
 576        struct scsi_cmnd *sc;
 577        int state;
 578
 579        /*
 580         * if a command completes and we get a successful tmf response
 581         * we will hit this because the scsi eh abort code does not take
 582         * a ref to the task.
 583         */
 584        sc = task->sc;
 585        if (!sc)
 586                return;
 587
 588        if (task->state == ISCSI_TASK_PENDING) {
 589                /*
 590                 * cmd never made it to the xmit thread, so we should not count
 591                 * the cmd in the sequencing
 592                 */
 593                conn->session->queued_cmdsn--;
 594                /* it was never sent so just complete like normal */
 595                state = ISCSI_TASK_COMPLETED;
 596        } else if (err == DID_TRANSPORT_DISRUPTED)
 597                state = ISCSI_TASK_ABRT_SESS_RECOV;
 598        else
 599                state = ISCSI_TASK_ABRT_TMF;
 600
 601        sc->result = err << 16;
 602        scsi_set_resid(sc, scsi_bufflen(sc));
 603
 604        /* regular RX path uses back_lock */
 605        spin_lock_bh(&conn->session->back_lock);
 606        iscsi_complete_task(task, state);
 607        spin_unlock_bh(&conn->session->back_lock);
 608}
 609
 610static int iscsi_prep_mgmt_task(struct iscsi_conn *conn,
 611                                struct iscsi_task *task)
 612{
 613        struct iscsi_session *session = conn->session;
 614        struct iscsi_hdr *hdr = task->hdr;
 615        struct iscsi_nopout *nop = (struct iscsi_nopout *)hdr;
 616        uint8_t opcode = hdr->opcode & ISCSI_OPCODE_MASK;
 617
 618        if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
 619                return -ENOTCONN;
 620
 621        if (opcode != ISCSI_OP_LOGIN && opcode != ISCSI_OP_TEXT)
 622                nop->exp_statsn = cpu_to_be32(conn->exp_statsn);
 623        /*
 624         * pre-format CmdSN for outgoing PDU.
 625         */
 626        nop->cmdsn = cpu_to_be32(session->cmdsn);
 627        if (hdr->itt != RESERVED_ITT) {
 628                /*
 629                 * TODO: We always use immediate for normal session pdus.
 630                 * If we start to send tmfs or nops as non-immediate then
 631                 * we should start checking the cmdsn numbers for mgmt tasks.
 632                 *
 633                 * During discovery sessions iscsid sends TEXT as non immediate,
 634                 * but we always only send one PDU at a time.
 635                 */
 636                if (conn->c_stage == ISCSI_CONN_STARTED &&
 637                    !(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
 638                        session->queued_cmdsn++;
 639                        session->cmdsn++;
 640                }
 641        }
 642
 643        if (session->tt->init_task && session->tt->init_task(task))
 644                return -EIO;
 645
 646        if ((hdr->opcode & ISCSI_OPCODE_MASK) == ISCSI_OP_LOGOUT)
 647                session->state = ISCSI_STATE_LOGGING_OUT;
 648
 649        task->state = ISCSI_TASK_RUNNING;
 650        ISCSI_DBG_SESSION(session, "mgmtpdu [op 0x%x hdr->itt 0x%x "
 651                          "datalen %d]\n", hdr->opcode & ISCSI_OPCODE_MASK,
 652                          hdr->itt, task->data_count);
 653        return 0;
 654}
 655
 656static struct iscsi_task *
 657__iscsi_conn_send_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 658                      char *data, uint32_t data_size)
 659{
 660        struct iscsi_session *session = conn->session;
 661        struct iscsi_host *ihost = shost_priv(session->host);
 662        uint8_t opcode = hdr->opcode & ISCSI_OPCODE_MASK;
 663        struct iscsi_task *task;
 664        itt_t itt;
 665
 666        if (session->state == ISCSI_STATE_TERMINATE)
 667                return NULL;
 668
 669        if (opcode == ISCSI_OP_LOGIN || opcode == ISCSI_OP_TEXT) {
 670                /*
 671                 * Login and Text are sent serially, in
 672                 * request-followed-by-response sequence.
 673                 * Same task can be used. Same ITT must be used.
 674                 * Note that login_task is preallocated at conn_create().
 675                 */
 676                if (conn->login_task->state != ISCSI_TASK_FREE) {
 677                        iscsi_conn_printk(KERN_ERR, conn, "Login/Text in "
 678                                          "progress. Cannot start new task.\n");
 679                        return NULL;
 680                }
 681
 682                if (data_size > ISCSI_DEF_MAX_RECV_SEG_LEN) {
 683                        iscsi_conn_printk(KERN_ERR, conn, "Invalid buffer len of %u for login task. Max len is %u\n", data_size, ISCSI_DEF_MAX_RECV_SEG_LEN);
 684                        return NULL;
 685                }
 686
 687                task = conn->login_task;
 688        } else {
 689                if (session->state != ISCSI_STATE_LOGGED_IN)
 690                        return NULL;
 691
 692                if (data_size != 0) {
 693                        iscsi_conn_printk(KERN_ERR, conn, "Can not send data buffer of len %u for op 0x%x\n", data_size, opcode);
 694                        return NULL;
 695                }
 696
 697                BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
 698                BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);
 699
 700                if (!kfifo_out(&session->cmdpool.queue,
 701                                 (void*)&task, sizeof(void*)))
 702                        return NULL;
 703        }
 704        /*
 705         * released in complete pdu for task we expect a response for, and
 706         * released by the lld when it has transmitted the task for
 707         * pdus we do not expect a response for.
 708         */
 709        refcount_set(&task->refcount, 1);
 710        task->conn = conn;
 711        task->sc = NULL;
 712        INIT_LIST_HEAD(&task->running);
 713        task->state = ISCSI_TASK_PENDING;
 714
 715        if (data_size) {
 716                memcpy(task->data, data, data_size);
 717                task->data_count = data_size;
 718        } else
 719                task->data_count = 0;
 720
 721        if (conn->session->tt->alloc_pdu) {
 722                if (conn->session->tt->alloc_pdu(task, hdr->opcode)) {
 723                        iscsi_conn_printk(KERN_ERR, conn, "Could not allocate "
 724                                         "pdu for mgmt task.\n");
 725                        goto free_task;
 726                }
 727        }
 728
 729        itt = task->hdr->itt;
 730        task->hdr_len = sizeof(struct iscsi_hdr);
 731        memcpy(task->hdr, hdr, sizeof(struct iscsi_hdr));
 732
 733        if (hdr->itt != RESERVED_ITT) {
 734                if (session->tt->parse_pdu_itt)
 735                        task->hdr->itt = itt;
 736                else
 737                        task->hdr->itt = build_itt(task->itt,
 738                                                   task->conn->session->age);
 739        }
 740
 741        if (!ihost->workq) {
 742                if (iscsi_prep_mgmt_task(conn, task))
 743                        goto free_task;
 744
 745                if (session->tt->xmit_task(task))
 746                        goto free_task;
 747        } else {
 748                spin_lock_bh(&conn->taskqueuelock);
 749                list_add_tail(&task->running, &conn->mgmtqueue);
 750                spin_unlock_bh(&conn->taskqueuelock);
 751                iscsi_conn_queue_work(conn);
 752        }
 753
 754        return task;
 755
 756free_task:
 757        /* regular RX path uses back_lock */
 758        spin_lock(&session->back_lock);
 759        __iscsi_put_task(task);
 760        spin_unlock(&session->back_lock);
 761        return NULL;
 762}
 763
 764int iscsi_conn_send_pdu(struct iscsi_cls_conn *cls_conn, struct iscsi_hdr *hdr,
 765                        char *data, uint32_t data_size)
 766{
 767        struct iscsi_conn *conn = cls_conn->dd_data;
 768        struct iscsi_session *session = conn->session;
 769        int err = 0;
 770
 771        spin_lock_bh(&session->frwd_lock);
 772        if (!__iscsi_conn_send_pdu(conn, hdr, data, data_size))
 773                err = -EPERM;
 774        spin_unlock_bh(&session->frwd_lock);
 775        return err;
 776}
 777EXPORT_SYMBOL_GPL(iscsi_conn_send_pdu);
 778
 779/**
 780 * iscsi_cmd_rsp - SCSI Command Response processing
 781 * @conn: iscsi connection
 782 * @hdr: iscsi header
 783 * @task: scsi command task
 784 * @data: cmd data buffer
 785 * @datalen: len of buffer
 786 *
 787 * iscsi_cmd_rsp sets up the scsi_cmnd fields based on the PDU and
 788 * then completes the command and task. called under back_lock
 789 **/
 790static void iscsi_scsi_cmd_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 791                               struct iscsi_task *task, char *data,
 792                               int datalen)
 793{
 794        struct iscsi_scsi_rsp *rhdr = (struct iscsi_scsi_rsp *)hdr;
 795        struct iscsi_session *session = conn->session;
 796        struct scsi_cmnd *sc = task->sc;
 797
 798        iscsi_update_cmdsn(session, (struct iscsi_nopin*)rhdr);
 799        conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 800
 801        sc->result = (DID_OK << 16) | rhdr->cmd_status;
 802
 803        if (task->protected) {
 804                sector_t sector;
 805                u8 ascq;
 806
 807                /**
 808                 * Transports that didn't implement check_protection
 809                 * callback but still published T10-PI support to scsi-mid
 810                 * deserve this BUG_ON.
 811                 **/
 812                BUG_ON(!session->tt->check_protection);
 813
 814                ascq = session->tt->check_protection(task, &sector);
 815                if (ascq) {
 816                        sc->result = DRIVER_SENSE << 24 |
 817                                     SAM_STAT_CHECK_CONDITION;
 818                        scsi_build_sense_buffer(1, sc->sense_buffer,
 819                                                ILLEGAL_REQUEST, 0x10, ascq);
 820                        scsi_set_sense_information(sc->sense_buffer,
 821                                                   SCSI_SENSE_BUFFERSIZE,
 822                                                   sector);
 823                        goto out;
 824                }
 825        }
 826
 827        if (rhdr->response != ISCSI_STATUS_CMD_COMPLETED) {
 828                sc->result = DID_ERROR << 16;
 829                goto out;
 830        }
 831
 832        if (rhdr->cmd_status == SAM_STAT_CHECK_CONDITION) {
 833                uint16_t senselen;
 834
 835                if (datalen < 2) {
 836invalid_datalen:
 837                        iscsi_conn_printk(KERN_ERR,  conn,
 838                                         "Got CHECK_CONDITION but invalid data "
 839                                         "buffer size of %d\n", datalen);
 840                        sc->result = DID_BAD_TARGET << 16;
 841                        goto out;
 842                }
 843
 844                senselen = get_unaligned_be16(data);
 845                if (datalen < senselen)
 846                        goto invalid_datalen;
 847
 848                memcpy(sc->sense_buffer, data + 2,
 849                       min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
 850                ISCSI_DBG_SESSION(session, "copied %d bytes of sense\n",
 851                                  min_t(uint16_t, senselen,
 852                                  SCSI_SENSE_BUFFERSIZE));
 853        }
 854
 855        if (rhdr->flags & (ISCSI_FLAG_CMD_BIDI_UNDERFLOW |
 856                           ISCSI_FLAG_CMD_BIDI_OVERFLOW)) {
 857                sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 858        }
 859
 860        if (rhdr->flags & (ISCSI_FLAG_CMD_UNDERFLOW |
 861                           ISCSI_FLAG_CMD_OVERFLOW)) {
 862                int res_count = be32_to_cpu(rhdr->residual_count);
 863
 864                if (res_count > 0 &&
 865                    (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
 866                     res_count <= scsi_bufflen(sc)))
 867                        /* write side for bidi or uni-io set_resid */
 868                        scsi_set_resid(sc, res_count);
 869                else
 870                        sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 871        }
 872out:
 873        ISCSI_DBG_SESSION(session, "cmd rsp done [sc %p res %d itt 0x%x]\n",
 874                          sc, sc->result, task->itt);
 875        conn->scsirsp_pdus_cnt++;
 876        iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 877}
 878
 879/**
 880 * iscsi_data_in_rsp - SCSI Data-In Response processing
 881 * @conn: iscsi connection
 882 * @hdr:  iscsi pdu
 883 * @task: scsi command task
 884 *
 885 * iscsi_data_in_rsp sets up the scsi_cmnd fields based on the data received
 886 * then completes the command and task. called under back_lock
 887 **/
 888static void
 889iscsi_data_in_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 890                  struct iscsi_task *task)
 891{
 892        struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)hdr;
 893        struct scsi_cmnd *sc = task->sc;
 894
 895        if (!(rhdr->flags & ISCSI_FLAG_DATA_STATUS))
 896                return;
 897
 898        iscsi_update_cmdsn(conn->session, (struct iscsi_nopin *)hdr);
 899        sc->result = (DID_OK << 16) | rhdr->cmd_status;
 900        conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 901        if (rhdr->flags & (ISCSI_FLAG_DATA_UNDERFLOW |
 902                           ISCSI_FLAG_DATA_OVERFLOW)) {
 903                int res_count = be32_to_cpu(rhdr->residual_count);
 904
 905                if (res_count > 0 &&
 906                    (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
 907                     res_count <= sc->sdb.length))
 908                        scsi_set_resid(sc, res_count);
 909                else
 910                        sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 911        }
 912
 913        ISCSI_DBG_SESSION(conn->session, "data in with status done "
 914                          "[sc %p res %d itt 0x%x]\n",
 915                          sc, sc->result, task->itt);
 916        conn->scsirsp_pdus_cnt++;
 917        iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 918}
 919
 920static void iscsi_tmf_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
 921{
 922        struct iscsi_tm_rsp *tmf = (struct iscsi_tm_rsp *)hdr;
 923
 924        conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 925        conn->tmfrsp_pdus_cnt++;
 926
 927        if (conn->tmf_state != TMF_QUEUED)
 928                return;
 929
 930        if (tmf->response == ISCSI_TMF_RSP_COMPLETE)
 931                conn->tmf_state = TMF_SUCCESS;
 932        else if (tmf->response == ISCSI_TMF_RSP_NO_TASK)
 933                conn->tmf_state = TMF_NOT_FOUND;
 934        else
 935                conn->tmf_state = TMF_FAILED;
 936        wake_up(&conn->ehwait);
 937}
 938
 939static int iscsi_send_nopout(struct iscsi_conn *conn, struct iscsi_nopin *rhdr)
 940{
 941        struct iscsi_nopout hdr;
 942        struct iscsi_task *task;
 943
 944        if (!rhdr && conn->ping_task)
 945                return -EINVAL;
 946
 947        memset(&hdr, 0, sizeof(struct iscsi_nopout));
 948        hdr.opcode = ISCSI_OP_NOOP_OUT | ISCSI_OP_IMMEDIATE;
 949        hdr.flags = ISCSI_FLAG_CMD_FINAL;
 950
 951        if (rhdr) {
 952                hdr.lun = rhdr->lun;
 953                hdr.ttt = rhdr->ttt;
 954                hdr.itt = RESERVED_ITT;
 955        } else
 956                hdr.ttt = RESERVED_ITT;
 957
 958        task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)&hdr, NULL, 0);
 959        if (!task) {
 960                iscsi_conn_printk(KERN_ERR, conn, "Could not send nopout\n");
 961                return -EIO;
 962        } else if (!rhdr) {
 963                /* only track our nops */
 964                conn->ping_task = task;
 965                conn->last_ping = jiffies;
 966        }
 967
 968        return 0;
 969}
 970
 971/**
 972 * iscsi_nop_out_rsp - SCSI NOP Response processing
 973 * @task: scsi command task
 974 * @nop: the nop structure
 975 * @data: where to put the data
 976 * @datalen: length of data
 977 *
 978 * iscsi_nop_out_rsp handles nop response from use or
 979 * from user space. called under back_lock
 980 **/
 981static int iscsi_nop_out_rsp(struct iscsi_task *task,
 982                             struct iscsi_nopin *nop, char *data, int datalen)
 983{
 984        struct iscsi_conn *conn = task->conn;
 985        int rc = 0;
 986
 987        if (conn->ping_task != task) {
 988                /*
 989                 * If this is not in response to one of our
 990                 * nops then it must be from userspace.
 991                 */
 992                if (iscsi_recv_pdu(conn->cls_conn, (struct iscsi_hdr *)nop,
 993                                   data, datalen))
 994                        rc = ISCSI_ERR_CONN_FAILED;
 995        } else
 996                mod_timer(&conn->transport_timer, jiffies + conn->recv_timeout);
 997        iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 998        return rc;
 999}
1000
1001static int iscsi_handle_reject(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1002                               char *data, int datalen)
1003{
1004        struct iscsi_reject *reject = (struct iscsi_reject *)hdr;
1005        struct iscsi_hdr rejected_pdu;
1006        int opcode, rc = 0;
1007
1008        conn->exp_statsn = be32_to_cpu(reject->statsn) + 1;
1009
1010        if (ntoh24(reject->dlength) > datalen ||
1011            ntoh24(reject->dlength) < sizeof(struct iscsi_hdr)) {
1012                iscsi_conn_printk(KERN_ERR, conn, "Cannot handle rejected "
1013                                  "pdu. Invalid data length (pdu dlength "
1014                                  "%u, datalen %d\n", ntoh24(reject->dlength),
1015                                  datalen);
1016                return ISCSI_ERR_PROTO;
1017        }
1018        memcpy(&rejected_pdu, data, sizeof(struct iscsi_hdr));
1019        opcode = rejected_pdu.opcode & ISCSI_OPCODE_MASK;
1020
1021        switch (reject->reason) {
1022        case ISCSI_REASON_DATA_DIGEST_ERROR:
1023                iscsi_conn_printk(KERN_ERR, conn,
1024                                  "pdu (op 0x%x itt 0x%x) rejected "
1025                                  "due to DataDigest error.\n",
1026                                  opcode, rejected_pdu.itt);
1027                break;
1028        case ISCSI_REASON_IMM_CMD_REJECT:
1029                iscsi_conn_printk(KERN_ERR, conn,
1030                                  "pdu (op 0x%x itt 0x%x) rejected. Too many "
1031                                  "immediate commands.\n",
1032                                  opcode, rejected_pdu.itt);
1033                /*
1034                 * We only send one TMF at a time so if the target could not
1035                 * handle it, then it should get fixed (RFC mandates that
1036                 * a target can handle one immediate TMF per conn).
1037                 *
1038                 * For nops-outs, we could have sent more than one if
1039                 * the target is sending us lots of nop-ins
1040                 */
1041                if (opcode != ISCSI_OP_NOOP_OUT)
1042                        return 0;
1043
1044                if (rejected_pdu.itt == cpu_to_be32(ISCSI_RESERVED_TAG)) {
1045                        /*
1046                         * nop-out in response to target's nop-out rejected.
1047                         * Just resend.
1048                         */
1049                        /* In RX path we are under back lock */
1050                        spin_unlock(&conn->session->back_lock);
1051                        spin_lock(&conn->session->frwd_lock);
1052                        iscsi_send_nopout(conn,
1053                                          (struct iscsi_nopin*)&rejected_pdu);
1054                        spin_unlock(&conn->session->frwd_lock);
1055                        spin_lock(&conn->session->back_lock);
1056                } else {
1057                        struct iscsi_task *task;
1058                        /*
1059                         * Our nop as ping got dropped. We know the target
1060                         * and transport are ok so just clean up
1061                         */
1062                        task = iscsi_itt_to_task(conn, rejected_pdu.itt);
1063                        if (!task) {
1064                                iscsi_conn_printk(KERN_ERR, conn,
1065                                                 "Invalid pdu reject. Could "
1066                                                 "not lookup rejected task.\n");
1067                                rc = ISCSI_ERR_BAD_ITT;
1068                        } else
1069                                rc = iscsi_nop_out_rsp(task,
1070                                        (struct iscsi_nopin*)&rejected_pdu,
1071                                        NULL, 0);
1072                }
1073                break;
1074        default:
1075                iscsi_conn_printk(KERN_ERR, conn,
1076                                  "pdu (op 0x%x itt 0x%x) rejected. Reason "
1077                                  "code 0x%x\n", rejected_pdu.opcode,
1078                                  rejected_pdu.itt, reject->reason);
1079                break;
1080        }
1081        return rc;
1082}
1083
1084/**
1085 * iscsi_itt_to_task - look up task by itt
1086 * @conn: iscsi connection
1087 * @itt: itt
1088 *
1089 * This should be used for mgmt tasks like login and nops, or if
1090 * the LDD's itt space does not include the session age.
1091 *
1092 * The session back_lock must be held.
1093 */
1094struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *conn, itt_t itt)
1095{
1096        struct iscsi_session *session = conn->session;
1097        int i;
1098
1099        if (itt == RESERVED_ITT)
1100                return NULL;
1101
1102        if (session->tt->parse_pdu_itt)
1103                session->tt->parse_pdu_itt(conn, itt, &i, NULL);
1104        else
1105                i = get_itt(itt);
1106        if (i >= session->cmds_max)
1107                return NULL;
1108
1109        return session->cmds[i];
1110}
1111EXPORT_SYMBOL_GPL(iscsi_itt_to_task);
1112
1113/**
1114 * __iscsi_complete_pdu - complete pdu
1115 * @conn: iscsi conn
1116 * @hdr: iscsi header
1117 * @data: data buffer
1118 * @datalen: len of data buffer
1119 *
1120 * Completes pdu processing by freeing any resources allocated at
1121 * queuecommand or send generic. session back_lock must be held and verify
1122 * itt must have been called.
1123 */
1124int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1125                         char *data, int datalen)
1126{
1127        struct iscsi_session *session = conn->session;
1128        int opcode = hdr->opcode & ISCSI_OPCODE_MASK, rc = 0;
1129        struct iscsi_task *task;
1130        uint32_t itt;
1131
1132        conn->last_recv = jiffies;
1133        rc = iscsi_verify_itt(conn, hdr->itt);
1134        if (rc)
1135                return rc;
1136
1137        if (hdr->itt != RESERVED_ITT)
1138                itt = get_itt(hdr->itt);
1139        else
1140                itt = ~0U;
1141
1142        ISCSI_DBG_SESSION(session, "[op 0x%x cid %d itt 0x%x len %d]\n",
1143                          opcode, conn->id, itt, datalen);
1144
1145        if (itt == ~0U) {
1146                iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1147
1148                switch(opcode) {
1149                case ISCSI_OP_NOOP_IN:
1150                        if (datalen) {
1151                                rc = ISCSI_ERR_PROTO;
1152                                break;
1153                        }
1154
1155                        if (hdr->ttt == cpu_to_be32(ISCSI_RESERVED_TAG))
1156                                break;
1157
1158                        /* In RX path we are under back lock */
1159                        spin_unlock(&session->back_lock);
1160                        spin_lock(&session->frwd_lock);
1161                        iscsi_send_nopout(conn, (struct iscsi_nopin*)hdr);
1162                        spin_unlock(&session->frwd_lock);
1163                        spin_lock(&session->back_lock);
1164                        break;
1165                case ISCSI_OP_REJECT:
1166                        rc = iscsi_handle_reject(conn, hdr, data, datalen);
1167                        break;
1168                case ISCSI_OP_ASYNC_EVENT:
1169                        conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1170                        if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
1171                                rc = ISCSI_ERR_CONN_FAILED;
1172                        break;
1173                default:
1174                        rc = ISCSI_ERR_BAD_OPCODE;
1175                        break;
1176                }
1177                goto out;
1178        }
1179
1180        switch(opcode) {
1181        case ISCSI_OP_SCSI_CMD_RSP:
1182        case ISCSI_OP_SCSI_DATA_IN:
1183                task = iscsi_itt_to_ctask(conn, hdr->itt);
1184                if (!task)
1185                        return ISCSI_ERR_BAD_ITT;
1186                task->last_xfer = jiffies;
1187                break;
1188        case ISCSI_OP_R2T:
1189                /*
1190                 * LLD handles R2Ts if they need to.
1191                 */
1192                return 0;
1193        case ISCSI_OP_LOGOUT_RSP:
1194        case ISCSI_OP_LOGIN_RSP:
1195        case ISCSI_OP_TEXT_RSP:
1196        case ISCSI_OP_SCSI_TMFUNC_RSP:
1197        case ISCSI_OP_NOOP_IN:
1198                task = iscsi_itt_to_task(conn, hdr->itt);
1199                if (!task)
1200                        return ISCSI_ERR_BAD_ITT;
1201                break;
1202        default:
1203                return ISCSI_ERR_BAD_OPCODE;
1204        }
1205
1206        switch(opcode) {
1207        case ISCSI_OP_SCSI_CMD_RSP:
1208                iscsi_scsi_cmd_rsp(conn, hdr, task, data, datalen);
1209                break;
1210        case ISCSI_OP_SCSI_DATA_IN:
1211                iscsi_data_in_rsp(conn, hdr, task);
1212                break;
1213        case ISCSI_OP_LOGOUT_RSP:
1214                iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1215                if (datalen) {
1216                        rc = ISCSI_ERR_PROTO;
1217                        break;
1218                }
1219                conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1220                goto recv_pdu;
1221        case ISCSI_OP_LOGIN_RSP:
1222        case ISCSI_OP_TEXT_RSP:
1223                iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1224                /*
1225                 * login related PDU's exp_statsn is handled in
1226                 * userspace
1227                 */
1228                goto recv_pdu;
1229        case ISCSI_OP_SCSI_TMFUNC_RSP:
1230                iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1231                if (datalen) {
1232                        rc = ISCSI_ERR_PROTO;
1233                        break;
1234                }
1235
1236                iscsi_tmf_rsp(conn, hdr);
1237                iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1238                break;
1239        case ISCSI_OP_NOOP_IN:
1240                iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1241                if (hdr->ttt != cpu_to_be32(ISCSI_RESERVED_TAG) || datalen) {
1242                        rc = ISCSI_ERR_PROTO;
1243                        break;
1244                }
1245                conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1246
1247                rc = iscsi_nop_out_rsp(task, (struct iscsi_nopin*)hdr,
1248                                       data, datalen);
1249                break;
1250        default:
1251                rc = ISCSI_ERR_BAD_OPCODE;
1252                break;
1253        }
1254
1255out:
1256        return rc;
1257recv_pdu:
1258        if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
1259                rc = ISCSI_ERR_CONN_FAILED;
1260        iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1261        return rc;
1262}
1263EXPORT_SYMBOL_GPL(__iscsi_complete_pdu);
1264
1265int iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1266                       char *data, int datalen)
1267{
1268        int rc;
1269
1270        spin_lock(&conn->session->back_lock);
1271        rc = __iscsi_complete_pdu(conn, hdr, data, datalen);
1272        spin_unlock(&conn->session->back_lock);
1273        return rc;
1274}
1275EXPORT_SYMBOL_GPL(iscsi_complete_pdu);
1276
1277int iscsi_verify_itt(struct iscsi_conn *conn, itt_t itt)
1278{
1279        struct iscsi_session *session = conn->session;
1280        int age = 0, i = 0;
1281
1282        if (itt == RESERVED_ITT)
1283                return 0;
1284
1285        if (session->tt->parse_pdu_itt)
1286                session->tt->parse_pdu_itt(conn, itt, &i, &age);
1287        else {
1288                i = get_itt(itt);
1289                age = ((__force u32)itt >> ISCSI_AGE_SHIFT) & ISCSI_AGE_MASK;
1290        }
1291
1292        if (age != session->age) {
1293                iscsi_conn_printk(KERN_ERR, conn,
1294                                  "received itt %x expected session age (%x)\n",
1295                                  (__force u32)itt, session->age);
1296                return ISCSI_ERR_BAD_ITT;
1297        }
1298
1299        if (i >= session->cmds_max) {
1300                iscsi_conn_printk(KERN_ERR, conn,
1301                                  "received invalid itt index %u (max cmds "
1302                                   "%u.\n", i, session->cmds_max);
1303                return ISCSI_ERR_BAD_ITT;
1304        }
1305        return 0;
1306}
1307EXPORT_SYMBOL_GPL(iscsi_verify_itt);
1308
1309/**
1310 * iscsi_itt_to_ctask - look up ctask by itt
1311 * @conn: iscsi connection
1312 * @itt: itt
1313 *
1314 * This should be used for cmd tasks.
1315 *
1316 * The session back_lock must be held.
1317 */
1318struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *conn, itt_t itt)
1319{
1320        struct iscsi_task *task;
1321
1322        if (iscsi_verify_itt(conn, itt))
1323                return NULL;
1324
1325        task = iscsi_itt_to_task(conn, itt);
1326        if (!task || !task->sc)
1327                return NULL;
1328
1329        if (task->sc->SCp.phase != conn->session->age) {
1330                iscsi_session_printk(KERN_ERR, conn->session,
1331                                  "task's session age %d, expected %d\n",
1332                                  task->sc->SCp.phase, conn->session->age);
1333                return NULL;
1334        }
1335
1336        return task;
1337}
1338EXPORT_SYMBOL_GPL(iscsi_itt_to_ctask);
1339
1340void iscsi_session_failure(struct iscsi_session *session,
1341                           enum iscsi_err err)
1342{
1343        struct iscsi_conn *conn;
1344        struct device *dev;
1345
1346        spin_lock_bh(&session->frwd_lock);
1347        conn = session->leadconn;
1348        if (session->state == ISCSI_STATE_TERMINATE || !conn) {
1349                spin_unlock_bh(&session->frwd_lock);
1350                return;
1351        }
1352
1353        dev = get_device(&conn->cls_conn->dev);
1354        spin_unlock_bh(&session->frwd_lock);
1355        if (!dev)
1356                return;
1357        /*
1358         * if the host is being removed bypass the connection
1359         * recovery initialization because we are going to kill
1360         * the session.
1361         */
1362        if (err == ISCSI_ERR_INVALID_HOST)
1363                iscsi_conn_error_event(conn->cls_conn, err);
1364        else
1365                iscsi_conn_failure(conn, err);
1366        put_device(dev);
1367}
1368EXPORT_SYMBOL_GPL(iscsi_session_failure);
1369
1370void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err)
1371{
1372        struct iscsi_session *session = conn->session;
1373
1374        spin_lock_bh(&session->frwd_lock);
1375        if (session->state == ISCSI_STATE_FAILED) {
1376                spin_unlock_bh(&session->frwd_lock);
1377                return;
1378        }
1379
1380        if (conn->stop_stage == 0)
1381                session->state = ISCSI_STATE_FAILED;
1382        spin_unlock_bh(&session->frwd_lock);
1383
1384        set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1385        set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
1386        iscsi_conn_error_event(conn->cls_conn, err);
1387}
1388EXPORT_SYMBOL_GPL(iscsi_conn_failure);
1389
1390static int iscsi_check_cmdsn_window_closed(struct iscsi_conn *conn)
1391{
1392        struct iscsi_session *session = conn->session;
1393
1394        /*
1395         * Check for iSCSI window and take care of CmdSN wrap-around
1396         */
1397        if (!iscsi_sna_lte(session->queued_cmdsn, session->max_cmdsn)) {
1398                ISCSI_DBG_SESSION(session, "iSCSI CmdSN closed. ExpCmdSn "
1399                                  "%u MaxCmdSN %u CmdSN %u/%u\n",
1400                                  session->exp_cmdsn, session->max_cmdsn,
1401                                  session->cmdsn, session->queued_cmdsn);
1402                return -ENOSPC;
1403        }
1404        return 0;
1405}
1406
1407static int iscsi_xmit_task(struct iscsi_conn *conn)
1408{
1409        struct iscsi_task *task = conn->task;
1410        int rc;
1411
1412        if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx))
1413                return -ENODATA;
1414
1415        spin_lock_bh(&conn->session->back_lock);
1416        if (conn->task == NULL) {
1417                spin_unlock_bh(&conn->session->back_lock);
1418                return -ENODATA;
1419        }
1420        __iscsi_get_task(task);
1421        spin_unlock_bh(&conn->session->back_lock);
1422        spin_unlock_bh(&conn->session->frwd_lock);
1423        rc = conn->session->tt->xmit_task(task);
1424        spin_lock_bh(&conn->session->frwd_lock);
1425        if (!rc) {
1426                /* done with this task */
1427                task->last_xfer = jiffies;
1428                conn->task = NULL;
1429        }
1430        /* regular RX path uses back_lock */
1431        spin_lock(&conn->session->back_lock);
1432        __iscsi_put_task(task);
1433        spin_unlock(&conn->session->back_lock);
1434        return rc;
1435}
1436
1437/**
1438 * iscsi_requeue_task - requeue task to run from session workqueue
1439 * @task: task to requeue
1440 *
1441 * LLDs that need to run a task from the session workqueue should call
1442 * this. The session frwd_lock must be held. This should only be called
1443 * by software drivers.
1444 */
1445void iscsi_requeue_task(struct iscsi_task *task)
1446{
1447        struct iscsi_conn *conn = task->conn;
1448
1449        /*
1450         * this may be on the requeue list already if the xmit_task callout
1451         * is handling the r2ts while we are adding new ones
1452         */
1453        spin_lock_bh(&conn->taskqueuelock);
1454        if (list_empty(&task->running))
1455                list_add_tail(&task->running, &conn->requeue);
1456        spin_unlock_bh(&conn->taskqueuelock);
1457        iscsi_conn_queue_work(conn);
1458}
1459EXPORT_SYMBOL_GPL(iscsi_requeue_task);
1460
1461/**
1462 * iscsi_data_xmit - xmit any command into the scheduled connection
1463 * @conn: iscsi connection
1464 *
1465 * Notes:
1466 *      The function can return -EAGAIN in which case the caller must
1467 *      re-schedule it again later or recover. '0' return code means
1468 *      successful xmit.
1469 **/
1470static int iscsi_data_xmit(struct iscsi_conn *conn)
1471{
1472        struct iscsi_task *task;
1473        int rc = 0;
1474
1475        spin_lock_bh(&conn->session->frwd_lock);
1476        if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx)) {
1477                ISCSI_DBG_SESSION(conn->session, "Tx suspended!\n");
1478                spin_unlock_bh(&conn->session->frwd_lock);
1479                return -ENODATA;
1480        }
1481
1482        if (conn->task) {
1483                rc = iscsi_xmit_task(conn);
1484                if (rc)
1485                        goto done;
1486        }
1487
1488        /*
1489         * process mgmt pdus like nops before commands since we should
1490         * only have one nop-out as a ping from us and targets should not
1491         * overflow us with nop-ins
1492         */
1493        spin_lock_bh(&conn->taskqueuelock);
1494check_mgmt:
1495        while (!list_empty(&conn->mgmtqueue)) {
1496                conn->task = list_entry(conn->mgmtqueue.next,
1497                                         struct iscsi_task, running);
1498                list_del_init(&conn->task->running);
1499                spin_unlock_bh(&conn->taskqueuelock);
1500                if (iscsi_prep_mgmt_task(conn, conn->task)) {
1501                        /* regular RX path uses back_lock */
1502                        spin_lock_bh(&conn->session->back_lock);
1503                        __iscsi_put_task(conn->task);
1504                        spin_unlock_bh(&conn->session->back_lock);
1505                        conn->task = NULL;
1506                        spin_lock_bh(&conn->taskqueuelock);
1507                        continue;
1508                }
1509                rc = iscsi_xmit_task(conn);
1510                if (rc)
1511                        goto done;
1512                spin_lock_bh(&conn->taskqueuelock);
1513        }
1514
1515        /* process pending command queue */
1516        while (!list_empty(&conn->cmdqueue)) {
1517                conn->task = list_entry(conn->cmdqueue.next, struct iscsi_task,
1518                                        running);
1519                list_del_init(&conn->task->running);
1520                spin_unlock_bh(&conn->taskqueuelock);
1521                if (conn->session->state == ISCSI_STATE_LOGGING_OUT) {
1522                        fail_scsi_task(conn->task, DID_IMM_RETRY);
1523                        spin_lock_bh(&conn->taskqueuelock);
1524                        continue;
1525                }
1526                rc = iscsi_prep_scsi_cmd_pdu(conn->task);
1527                if (rc) {
1528                        if (rc == -ENOMEM || rc == -EACCES) {
1529                                spin_lock_bh(&conn->taskqueuelock);
1530                                list_add_tail(&conn->task->running,
1531                                              &conn->cmdqueue);
1532                                conn->task = NULL;
1533                                spin_unlock_bh(&conn->taskqueuelock);
1534                                goto done;
1535                        } else
1536                                fail_scsi_task(conn->task, DID_ABORT);
1537                        spin_lock_bh(&conn->taskqueuelock);
1538                        continue;
1539                }
1540                rc = iscsi_xmit_task(conn);
1541                if (rc)
1542                        goto done;
1543                /*
1544                 * we could continuously get new task requests so
1545                 * we need to check the mgmt queue for nops that need to
1546                 * be sent to aviod starvation
1547                 */
1548                spin_lock_bh(&conn->taskqueuelock);
1549                if (!list_empty(&conn->mgmtqueue))
1550                        goto check_mgmt;
1551        }
1552
1553        while (!list_empty(&conn->requeue)) {
1554                /*
1555                 * we always do fastlogout - conn stop code will clean up.
1556                 */
1557                if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
1558                        break;
1559
1560                task = list_entry(conn->requeue.next, struct iscsi_task,
1561                                  running);
1562                if (iscsi_check_tmf_restrictions(task, ISCSI_OP_SCSI_DATA_OUT))
1563                        break;
1564
1565                conn->task = task;
1566                list_del_init(&conn->task->running);
1567                conn->task->state = ISCSI_TASK_RUNNING;
1568                spin_unlock_bh(&conn->taskqueuelock);
1569                rc = iscsi_xmit_task(conn);
1570                if (rc)
1571                        goto done;
1572                spin_lock_bh(&conn->taskqueuelock);
1573                if (!list_empty(&conn->mgmtqueue))
1574                        goto check_mgmt;
1575        }
1576        spin_unlock_bh(&conn->taskqueuelock);
1577        spin_unlock_bh(&conn->session->frwd_lock);
1578        return -ENODATA;
1579
1580done:
1581        spin_unlock_bh(&conn->session->frwd_lock);
1582        return rc;
1583}
1584
1585static void iscsi_xmitworker(struct work_struct *work)
1586{
1587        struct iscsi_conn *conn =
1588                container_of(work, struct iscsi_conn, xmitwork);
1589        int rc;
1590        /*
1591         * serialize Xmit worker on a per-connection basis.
1592         */
1593        do {
1594                rc = iscsi_data_xmit(conn);
1595        } while (rc >= 0 || rc == -EAGAIN);
1596}
1597
1598static inline struct iscsi_task *iscsi_alloc_task(struct iscsi_conn *conn,
1599                                                  struct scsi_cmnd *sc)
1600{
1601        struct iscsi_task *task;
1602
1603        if (!kfifo_out(&conn->session->cmdpool.queue,
1604                         (void *) &task, sizeof(void *)))
1605                return NULL;
1606
1607        sc->SCp.phase = conn->session->age;
1608        sc->SCp.ptr = (char *) task;
1609
1610        refcount_set(&task->refcount, 1);
1611        task->state = ISCSI_TASK_PENDING;
1612        task->conn = conn;
1613        task->sc = sc;
1614        task->have_checked_conn = false;
1615        task->last_timeout = jiffies;
1616        task->last_xfer = jiffies;
1617        task->protected = false;
1618        INIT_LIST_HEAD(&task->running);
1619        return task;
1620}
1621
1622enum {
1623        FAILURE_BAD_HOST = 1,
1624        FAILURE_SESSION_FAILED,
1625        FAILURE_SESSION_FREED,
1626        FAILURE_WINDOW_CLOSED,
1627        FAILURE_OOM,
1628        FAILURE_SESSION_TERMINATE,
1629        FAILURE_SESSION_IN_RECOVERY,
1630        FAILURE_SESSION_RECOVERY_TIMEOUT,
1631        FAILURE_SESSION_LOGGING_OUT,
1632        FAILURE_SESSION_NOT_READY,
1633};
1634
1635int iscsi_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *sc)
1636{
1637        struct iscsi_cls_session *cls_session;
1638        struct iscsi_host *ihost;
1639        int reason = 0;
1640        struct iscsi_session *session;
1641        struct iscsi_conn *conn;
1642        struct iscsi_task *task = NULL;
1643
1644        sc->result = 0;
1645        sc->SCp.ptr = NULL;
1646
1647        ihost = shost_priv(host);
1648
1649        cls_session = starget_to_session(scsi_target(sc->device));
1650        session = cls_session->dd_data;
1651        spin_lock_bh(&session->frwd_lock);
1652
1653        reason = iscsi_session_chkready(cls_session);
1654        if (reason) {
1655                sc->result = reason;
1656                goto fault;
1657        }
1658
1659        if (session->state != ISCSI_STATE_LOGGED_IN) {
1660                /*
1661                 * to handle the race between when we set the recovery state
1662                 * and block the session we requeue here (commands could
1663                 * be entering our queuecommand while a block is starting
1664                 * up because the block code is not locked)
1665                 */
1666                switch (session->state) {
1667                case ISCSI_STATE_FAILED:
1668                        /*
1669                         * cmds should fail during shutdown, if the session
1670                         * state is bad, allowing completion to happen
1671                         */
1672                        if (unlikely(system_state != SYSTEM_RUNNING)) {
1673                                reason = FAILURE_SESSION_FAILED;
1674                                sc->result = DID_NO_CONNECT << 16;
1675                                break;
1676                        }
1677                        /* fall through */
1678                case ISCSI_STATE_IN_RECOVERY:
1679                        reason = FAILURE_SESSION_IN_RECOVERY;
1680                        sc->result = DID_IMM_RETRY << 16;
1681                        break;
1682                case ISCSI_STATE_LOGGING_OUT:
1683                        reason = FAILURE_SESSION_LOGGING_OUT;
1684                        sc->result = DID_IMM_RETRY << 16;
1685                        break;
1686                case ISCSI_STATE_RECOVERY_FAILED:
1687                        reason = FAILURE_SESSION_RECOVERY_TIMEOUT;
1688                        sc->result = DID_TRANSPORT_FAILFAST << 16;
1689                        break;
1690                case ISCSI_STATE_TERMINATE:
1691                        reason = FAILURE_SESSION_TERMINATE;
1692                        sc->result = DID_NO_CONNECT << 16;
1693                        break;
1694                default:
1695                        reason = FAILURE_SESSION_FREED;
1696                        sc->result = DID_NO_CONNECT << 16;
1697                }
1698                goto fault;
1699        }
1700
1701        conn = session->leadconn;
1702        if (!conn) {
1703                reason = FAILURE_SESSION_FREED;
1704                sc->result = DID_NO_CONNECT << 16;
1705                goto fault;
1706        }
1707
1708        if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx)) {
1709                reason = FAILURE_SESSION_IN_RECOVERY;
1710                sc->result = DID_REQUEUE << 16;
1711                goto fault;
1712        }
1713
1714        if (iscsi_check_cmdsn_window_closed(conn)) {
1715                reason = FAILURE_WINDOW_CLOSED;
1716                goto reject;
1717        }
1718
1719        task = iscsi_alloc_task(conn, sc);
1720        if (!task) {
1721                reason = FAILURE_OOM;
1722                goto reject;
1723        }
1724
1725        if (!ihost->workq) {
1726                reason = iscsi_prep_scsi_cmd_pdu(task);
1727                if (reason) {
1728                        if (reason == -ENOMEM ||  reason == -EACCES) {
1729                                reason = FAILURE_OOM;
1730                                goto prepd_reject;
1731                        } else {
1732                                sc->result = DID_ABORT << 16;
1733                                goto prepd_fault;
1734                        }
1735                }
1736                if (session->tt->xmit_task(task)) {
1737                        session->cmdsn--;
1738                        reason = FAILURE_SESSION_NOT_READY;
1739                        goto prepd_reject;
1740                }
1741        } else {
1742                spin_lock_bh(&conn->taskqueuelock);
1743                list_add_tail(&task->running, &conn->cmdqueue);
1744                spin_unlock_bh(&conn->taskqueuelock);
1745                iscsi_conn_queue_work(conn);
1746        }
1747
1748        session->queued_cmdsn++;
1749        spin_unlock_bh(&session->frwd_lock);
1750        return 0;
1751
1752prepd_reject:
1753        spin_lock_bh(&session->back_lock);
1754        iscsi_complete_task(task, ISCSI_TASK_REQUEUE_SCSIQ);
1755        spin_unlock_bh(&session->back_lock);
1756reject:
1757        spin_unlock_bh(&session->frwd_lock);
1758        ISCSI_DBG_SESSION(session, "cmd 0x%x rejected (%d)\n",
1759                          sc->cmnd[0], reason);
1760        return SCSI_MLQUEUE_TARGET_BUSY;
1761
1762prepd_fault:
1763        spin_lock_bh(&session->back_lock);
1764        iscsi_complete_task(task, ISCSI_TASK_REQUEUE_SCSIQ);
1765        spin_unlock_bh(&session->back_lock);
1766fault:
1767        spin_unlock_bh(&session->frwd_lock);
1768        ISCSI_DBG_SESSION(session, "iscsi: cmd 0x%x is not queued (%d)\n",
1769                          sc->cmnd[0], reason);
1770        scsi_set_resid(sc, scsi_bufflen(sc));
1771        sc->scsi_done(sc);
1772        return 0;
1773}
1774EXPORT_SYMBOL_GPL(iscsi_queuecommand);
1775
1776int iscsi_target_alloc(struct scsi_target *starget)
1777{
1778        struct iscsi_cls_session *cls_session = starget_to_session(starget);
1779        struct iscsi_session *session = cls_session->dd_data;
1780
1781        starget->can_queue = session->scsi_cmds_max;
1782        return 0;
1783}
1784EXPORT_SYMBOL_GPL(iscsi_target_alloc);
1785
1786static void iscsi_tmf_timedout(struct timer_list *t)
1787{
1788        struct iscsi_conn *conn = from_timer(conn, t, tmf_timer);
1789        struct iscsi_session *session = conn->session;
1790
1791        spin_lock(&session->frwd_lock);
1792        if (conn->tmf_state == TMF_QUEUED) {
1793                conn->tmf_state = TMF_TIMEDOUT;
1794                ISCSI_DBG_EH(session, "tmf timedout\n");
1795                /* unblock eh_abort() */
1796                wake_up(&conn->ehwait);
1797        }
1798        spin_unlock(&session->frwd_lock);
1799}
1800
1801static int iscsi_exec_task_mgmt_fn(struct iscsi_conn *conn,
1802                                   struct iscsi_tm *hdr, int age,
1803                                   int timeout)
1804        __must_hold(&session->frwd_lock)
1805{
1806        struct iscsi_session *session = conn->session;
1807        struct iscsi_task *task;
1808
1809        task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)hdr,
1810                                      NULL, 0);
1811        if (!task) {
1812                spin_unlock_bh(&session->frwd_lock);
1813                iscsi_conn_printk(KERN_ERR, conn, "Could not send TMF.\n");
1814                iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1815                spin_lock_bh(&session->frwd_lock);
1816                return -EPERM;
1817        }
1818        conn->tmfcmd_pdus_cnt++;
1819        conn->tmf_timer.expires = timeout * HZ + jiffies;
1820        add_timer(&conn->tmf_timer);
1821        ISCSI_DBG_EH(session, "tmf set timeout\n");
1822
1823        spin_unlock_bh(&session->frwd_lock);
1824        mutex_unlock(&session->eh_mutex);
1825
1826        /*
1827         * block eh thread until:
1828         *
1829         * 1) tmf response
1830         * 2) tmf timeout
1831         * 3) session is terminated or restarted or userspace has
1832         * given up on recovery
1833         */
1834        wait_event_interruptible(conn->ehwait, age != session->age ||
1835                                 session->state != ISCSI_STATE_LOGGED_IN ||
1836                                 conn->tmf_state != TMF_QUEUED);
1837        if (signal_pending(current))
1838                flush_signals(current);
1839        del_timer_sync(&conn->tmf_timer);
1840
1841        mutex_lock(&session->eh_mutex);
1842        spin_lock_bh(&session->frwd_lock);
1843        /* if the session drops it will clean up the task */
1844        if (age != session->age ||
1845            session->state != ISCSI_STATE_LOGGED_IN)
1846                return -ENOTCONN;
1847        return 0;
1848}
1849
1850/*
1851 * Fail commands. session lock held and recv side suspended and xmit
1852 * thread flushed
1853 */
1854static void fail_scsi_tasks(struct iscsi_conn *conn, u64 lun, int error)
1855{
1856        struct iscsi_task *task;
1857        int i;
1858
1859        for (i = 0; i < conn->session->cmds_max; i++) {
1860                task = conn->session->cmds[i];
1861                if (!task->sc || task->state == ISCSI_TASK_FREE)
1862                        continue;
1863
1864                if (lun != -1 && lun != task->sc->device->lun)
1865                        continue;
1866
1867                ISCSI_DBG_SESSION(conn->session,
1868                                  "failing sc %p itt 0x%x state %d\n",
1869                                  task->sc, task->itt, task->state);
1870                fail_scsi_task(task, error);
1871        }
1872}
1873
1874/**
1875 * iscsi_suspend_queue - suspend iscsi_queuecommand
1876 * @conn: iscsi conn to stop queueing IO on
1877 *
1878 * This grabs the session frwd_lock to make sure no one is in
1879 * xmit_task/queuecommand, and then sets suspend to prevent
1880 * new commands from being queued. This only needs to be called
1881 * by offload drivers that need to sync a path like ep disconnect
1882 * with the iscsi_queuecommand/xmit_task. To start IO again libiscsi
1883 * will call iscsi_start_tx and iscsi_unblock_session when in FFP.
1884 */
1885void iscsi_suspend_queue(struct iscsi_conn *conn)
1886{
1887        spin_lock_bh(&conn->session->frwd_lock);
1888        set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1889        spin_unlock_bh(&conn->session->frwd_lock);
1890}
1891EXPORT_SYMBOL_GPL(iscsi_suspend_queue);
1892
1893/**
1894 * iscsi_suspend_tx - suspend iscsi_data_xmit
1895 * @conn: iscsi conn tp stop processing IO on.
1896 *
1897 * This function sets the suspend bit to prevent iscsi_data_xmit
1898 * from sending new IO, and if work is queued on the xmit thread
1899 * it will wait for it to be completed.
1900 */
1901void iscsi_suspend_tx(struct iscsi_conn *conn)
1902{
1903        struct Scsi_Host *shost = conn->session->host;
1904        struct iscsi_host *ihost = shost_priv(shost);
1905
1906        set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1907        if (ihost->workq)
1908                flush_workqueue(ihost->workq);
1909}
1910EXPORT_SYMBOL_GPL(iscsi_suspend_tx);
1911
1912static void iscsi_start_tx(struct iscsi_conn *conn)
1913{
1914        clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1915        iscsi_conn_queue_work(conn);
1916}
1917
1918/*
1919 * We want to make sure a ping is in flight. It has timed out.
1920 * And we are not busy processing a pdu that is making
1921 * progress but got started before the ping and is taking a while
1922 * to complete so the ping is just stuck behind it in a queue.
1923 */
1924static int iscsi_has_ping_timed_out(struct iscsi_conn *conn)
1925{
1926        if (conn->ping_task &&
1927            time_before_eq(conn->last_recv + (conn->recv_timeout * HZ) +
1928                           (conn->ping_timeout * HZ), jiffies))
1929                return 1;
1930        else
1931                return 0;
1932}
1933
1934enum blk_eh_timer_return iscsi_eh_cmd_timed_out(struct scsi_cmnd *sc)
1935{
1936        enum blk_eh_timer_return rc = BLK_EH_DONE;
1937        struct iscsi_task *task = NULL, *running_task;
1938        struct iscsi_cls_session *cls_session;
1939        struct iscsi_session *session;
1940        struct iscsi_conn *conn;
1941        int i;
1942
1943        cls_session = starget_to_session(scsi_target(sc->device));
1944        session = cls_session->dd_data;
1945
1946        ISCSI_DBG_EH(session, "scsi cmd %p timedout\n", sc);
1947
1948        spin_lock_bh(&session->frwd_lock);
1949        task = (struct iscsi_task *)sc->SCp.ptr;
1950        if (!task) {
1951                /*
1952                 * Raced with completion. Blk layer has taken ownership
1953                 * so let timeout code complete it now.
1954                 */
1955                rc = BLK_EH_DONE;
1956                goto done;
1957        }
1958
1959        if (session->state != ISCSI_STATE_LOGGED_IN) {
1960                /*
1961                 * During shutdown, if session is prematurely disconnected,
1962                 * recovery won't happen and there will be hung cmds. Not
1963                 * handling cmds would trigger EH, also bad in this case.
1964                 * Instead, handle cmd, allow completion to happen and let
1965                 * upper layer to deal with the result.
1966                 */
1967                if (unlikely(system_state != SYSTEM_RUNNING)) {
1968                        sc->result = DID_NO_CONNECT << 16;
1969                        ISCSI_DBG_EH(session, "sc on shutdown, handled\n");
1970                        rc = BLK_EH_DONE;
1971                        goto done;
1972                }
1973                /*
1974                 * We are probably in the middle of iscsi recovery so let
1975                 * that complete and handle the error.
1976                 */
1977                rc = BLK_EH_RESET_TIMER;
1978                goto done;
1979        }
1980
1981        conn = session->leadconn;
1982        if (!conn) {
1983                /* In the middle of shuting down */
1984                rc = BLK_EH_RESET_TIMER;
1985                goto done;
1986        }
1987
1988        /*
1989         * If we have sent (at least queued to the network layer) a pdu or
1990         * recvd one for the task since the last timeout ask for
1991         * more time. If on the next timeout we have not made progress
1992         * we can check if it is the task or connection when we send the
1993         * nop as a ping.
1994         */
1995        if (time_after(task->last_xfer, task->last_timeout)) {
1996                ISCSI_DBG_EH(session, "Command making progress. Asking "
1997                             "scsi-ml for more time to complete. "
1998                             "Last data xfer at %lu. Last timeout was at "
1999                             "%lu\n.", task->last_xfer, task->last_timeout);
2000                task->have_checked_conn = false;
2001                rc = BLK_EH_RESET_TIMER;
2002                goto done;
2003        }
2004
2005        if (!conn->recv_timeout && !conn->ping_timeout)
2006                goto done;
2007        /*
2008         * if the ping timedout then we are in the middle of cleaning up
2009         * and can let the iscsi eh handle it
2010         */
2011        if (iscsi_has_ping_timed_out(conn)) {
2012                rc = BLK_EH_RESET_TIMER;
2013                goto done;
2014        }
2015
2016        for (i = 0; i < conn->session->cmds_max; i++) {
2017                running_task = conn->session->cmds[i];
2018                if (!running_task->sc || running_task == task ||
2019                     running_task->state != ISCSI_TASK_RUNNING)
2020                        continue;
2021
2022                /*
2023                 * Only check if cmds started before this one have made
2024                 * progress, or this could never fail
2025                 */
2026                if (time_after(running_task->sc->jiffies_at_alloc,
2027                               task->sc->jiffies_at_alloc))
2028                        continue;
2029
2030                if (time_after(running_task->last_xfer, task->last_timeout)) {
2031                        /*
2032                         * This task has not made progress, but a task
2033                         * started before us has transferred data since
2034                         * we started/last-checked. We could be queueing
2035                         * too many tasks or the LU is bad.
2036                         *
2037                         * If the device is bad the cmds ahead of us on
2038                         * other devs will complete, and this loop will
2039                         * eventually fail starting the scsi eh.
2040                         */
2041                        ISCSI_DBG_EH(session, "Command has not made progress "
2042                                     "but commands ahead of it have. "
2043                                     "Asking scsi-ml for more time to "
2044                                     "complete. Our last xfer vs running task "
2045                                     "last xfer %lu/%lu. Last check %lu.\n",
2046                                     task->last_xfer, running_task->last_xfer,
2047                                     task->last_timeout);
2048                        rc = BLK_EH_RESET_TIMER;
2049                        goto done;
2050                }
2051        }
2052
2053        /* Assumes nop timeout is shorter than scsi cmd timeout */
2054        if (task->have_checked_conn)
2055                goto done;
2056
2057        /*
2058         * Checking the transport already or nop from a cmd timeout still
2059         * running
2060         */
2061        if (conn->ping_task) {
2062                task->have_checked_conn = true;
2063                rc = BLK_EH_RESET_TIMER;
2064                goto done;
2065        }
2066
2067        /* Make sure there is a transport check done */
2068        iscsi_send_nopout(conn, NULL);
2069        task->have_checked_conn = true;
2070        rc = BLK_EH_RESET_TIMER;
2071
2072done:
2073        if (task)
2074                task->last_timeout = jiffies;
2075        spin_unlock_bh(&session->frwd_lock);
2076        ISCSI_DBG_EH(session, "return %s\n", rc == BLK_EH_RESET_TIMER ?
2077                     "timer reset" : "shutdown or nh");
2078        return rc;
2079}
2080EXPORT_SYMBOL_GPL(iscsi_eh_cmd_timed_out);
2081
2082static void iscsi_check_transport_timeouts(struct timer_list *t)
2083{
2084        struct iscsi_conn *conn = from_timer(conn, t, transport_timer);
2085        struct iscsi_session *session = conn->session;
2086        unsigned long recv_timeout, next_timeout = 0, last_recv;
2087
2088        spin_lock(&session->frwd_lock);
2089        if (session->state != ISCSI_STATE_LOGGED_IN)
2090                goto done;
2091
2092        recv_timeout = conn->recv_timeout;
2093        if (!recv_timeout)
2094                goto done;
2095
2096        recv_timeout *= HZ;
2097        last_recv = conn->last_recv;
2098
2099        if (iscsi_has_ping_timed_out(conn)) {
2100                iscsi_conn_printk(KERN_ERR, conn, "ping timeout of %d secs "
2101                                  "expired, recv timeout %d, last rx %lu, "
2102                                  "last ping %lu, now %lu\n",
2103                                  conn->ping_timeout, conn->recv_timeout,
2104                                  last_recv, conn->last_ping, jiffies);
2105                spin_unlock(&session->frwd_lock);
2106                iscsi_conn_failure(conn, ISCSI_ERR_NOP_TIMEDOUT);
2107                return;
2108        }
2109
2110        if (time_before_eq(last_recv + recv_timeout, jiffies)) {
2111                /* send a ping to try to provoke some traffic */
2112                ISCSI_DBG_CONN(conn, "Sending nopout as ping\n");
2113                if (iscsi_send_nopout(conn, NULL))
2114                        next_timeout = jiffies + (1 * HZ);
2115                else
2116                        next_timeout = conn->last_ping + (conn->ping_timeout * HZ);
2117        } else
2118                next_timeout = last_recv + recv_timeout;
2119
2120        ISCSI_DBG_CONN(conn, "Setting next tmo %lu\n", next_timeout);
2121        mod_timer(&conn->transport_timer, next_timeout);
2122done:
2123        spin_unlock(&session->frwd_lock);
2124}
2125
2126static void iscsi_prep_abort_task_pdu(struct iscsi_task *task,
2127                                      struct iscsi_tm *hdr)
2128{
2129        memset(hdr, 0, sizeof(*hdr));
2130        hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2131        hdr->flags = ISCSI_TM_FUNC_ABORT_TASK & ISCSI_FLAG_TM_FUNC_MASK;
2132        hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2133        hdr->lun = task->lun;
2134        hdr->rtt = task->hdr_itt;
2135        hdr->refcmdsn = task->cmdsn;
2136}
2137
2138int iscsi_eh_abort(struct scsi_cmnd *sc)
2139{
2140        struct iscsi_cls_session *cls_session;
2141        struct iscsi_session *session;
2142        struct iscsi_conn *conn;
2143        struct iscsi_task *task;
2144        struct iscsi_tm *hdr;
2145        int age;
2146
2147        cls_session = starget_to_session(scsi_target(sc->device));
2148        session = cls_session->dd_data;
2149
2150        ISCSI_DBG_EH(session, "aborting sc %p\n", sc);
2151
2152        mutex_lock(&session->eh_mutex);
2153        spin_lock_bh(&session->frwd_lock);
2154        /*
2155         * if session was ISCSI_STATE_IN_RECOVERY then we may not have
2156         * got the command.
2157         */
2158        if (!sc->SCp.ptr) {
2159                ISCSI_DBG_EH(session, "sc never reached iscsi layer or "
2160                                      "it completed.\n");
2161                spin_unlock_bh(&session->frwd_lock);
2162                mutex_unlock(&session->eh_mutex);
2163                return SUCCESS;
2164        }
2165
2166        /*
2167         * If we are not logged in or we have started a new session
2168         * then let the host reset code handle this
2169         */
2170        if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN ||
2171            sc->SCp.phase != session->age) {
2172                spin_unlock_bh(&session->frwd_lock);
2173                mutex_unlock(&session->eh_mutex);
2174                ISCSI_DBG_EH(session, "failing abort due to dropped "
2175                                  "session.\n");
2176                return FAILED;
2177        }
2178
2179        conn = session->leadconn;
2180        conn->eh_abort_cnt++;
2181        age = session->age;
2182
2183        task = (struct iscsi_task *)sc->SCp.ptr;
2184        ISCSI_DBG_EH(session, "aborting [sc %p itt 0x%x]\n",
2185                     sc, task->itt);
2186
2187        /* task completed before time out */
2188        if (!task->sc) {
2189                ISCSI_DBG_EH(session, "sc completed while abort in progress\n");
2190                goto success;
2191        }
2192
2193        if (task->state == ISCSI_TASK_PENDING) {
2194                fail_scsi_task(task, DID_ABORT);
2195                goto success;
2196        }
2197
2198        /* only have one tmf outstanding at a time */
2199        if (conn->tmf_state != TMF_INITIAL)
2200                goto failed;
2201        conn->tmf_state = TMF_QUEUED;
2202
2203        hdr = &conn->tmhdr;
2204        iscsi_prep_abort_task_pdu(task, hdr);
2205
2206        if (iscsi_exec_task_mgmt_fn(conn, hdr, age, session->abort_timeout))
2207                goto failed;
2208
2209        switch (conn->tmf_state) {
2210        case TMF_SUCCESS:
2211                spin_unlock_bh(&session->frwd_lock);
2212                /*
2213                 * stop tx side incase the target had sent a abort rsp but
2214                 * the initiator was still writing out data.
2215                 */
2216                iscsi_suspend_tx(conn);
2217                /*
2218                 * we do not stop the recv side because targets have been
2219                 * good and have never sent us a successful tmf response
2220                 * then sent more data for the cmd.
2221                 */
2222                spin_lock_bh(&session->frwd_lock);
2223                fail_scsi_task(task, DID_ABORT);
2224                conn->tmf_state = TMF_INITIAL;
2225                memset(hdr, 0, sizeof(*hdr));
2226                spin_unlock_bh(&session->frwd_lock);
2227                iscsi_start_tx(conn);
2228                goto success_unlocked;
2229        case TMF_TIMEDOUT:
2230                spin_unlock_bh(&session->frwd_lock);
2231                iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2232                goto failed_unlocked;
2233        case TMF_NOT_FOUND:
2234                if (!sc->SCp.ptr) {
2235                        conn->tmf_state = TMF_INITIAL;
2236                        memset(hdr, 0, sizeof(*hdr));
2237                        /* task completed before tmf abort response */
2238                        ISCSI_DBG_EH(session, "sc completed while abort in "
2239                                              "progress\n");
2240                        goto success;
2241                }
2242                /* fall through */
2243        default:
2244                conn->tmf_state = TMF_INITIAL;
2245                goto failed;
2246        }
2247
2248success:
2249        spin_unlock_bh(&session->frwd_lock);
2250success_unlocked:
2251        ISCSI_DBG_EH(session, "abort success [sc %p itt 0x%x]\n",
2252                     sc, task->itt);
2253        mutex_unlock(&session->eh_mutex);
2254        return SUCCESS;
2255
2256failed:
2257        spin_unlock_bh(&session->frwd_lock);
2258failed_unlocked:
2259        ISCSI_DBG_EH(session, "abort failed [sc %p itt 0x%x]\n", sc,
2260                     task ? task->itt : 0);
2261        mutex_unlock(&session->eh_mutex);
2262        return FAILED;
2263}
2264EXPORT_SYMBOL_GPL(iscsi_eh_abort);
2265
2266static void iscsi_prep_lun_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
2267{
2268        memset(hdr, 0, sizeof(*hdr));
2269        hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2270        hdr->flags = ISCSI_TM_FUNC_LOGICAL_UNIT_RESET & ISCSI_FLAG_TM_FUNC_MASK;
2271        hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2272        int_to_scsilun(sc->device->lun, &hdr->lun);
2273        hdr->rtt = RESERVED_ITT;
2274}
2275
2276int iscsi_eh_device_reset(struct scsi_cmnd *sc)
2277{
2278        struct iscsi_cls_session *cls_session;
2279        struct iscsi_session *session;
2280        struct iscsi_conn *conn;
2281        struct iscsi_tm *hdr;
2282        int rc = FAILED;
2283
2284        cls_session = starget_to_session(scsi_target(sc->device));
2285        session = cls_session->dd_data;
2286
2287        ISCSI_DBG_EH(session, "LU Reset [sc %p lun %llu]\n", sc,
2288                     sc->device->lun);
2289
2290        mutex_lock(&session->eh_mutex);
2291        spin_lock_bh(&session->frwd_lock);
2292        /*
2293         * Just check if we are not logged in. We cannot check for
2294         * the phase because the reset could come from a ioctl.
2295         */
2296        if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
2297                goto unlock;
2298        conn = session->leadconn;
2299
2300        /* only have one tmf outstanding at a time */
2301        if (conn->tmf_state != TMF_INITIAL)
2302                goto unlock;
2303        conn->tmf_state = TMF_QUEUED;
2304
2305        hdr = &conn->tmhdr;
2306        iscsi_prep_lun_reset_pdu(sc, hdr);
2307
2308        if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
2309                                    session->lu_reset_timeout)) {
2310                rc = FAILED;
2311                goto unlock;
2312        }
2313
2314        switch (conn->tmf_state) {
2315        case TMF_SUCCESS:
2316                break;
2317        case TMF_TIMEDOUT:
2318                spin_unlock_bh(&session->frwd_lock);
2319                iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2320                goto done;
2321        default:
2322                conn->tmf_state = TMF_INITIAL;
2323                goto unlock;
2324        }
2325
2326        rc = SUCCESS;
2327        spin_unlock_bh(&session->frwd_lock);
2328
2329        iscsi_suspend_tx(conn);
2330
2331        spin_lock_bh(&session->frwd_lock);
2332        memset(hdr, 0, sizeof(*hdr));
2333        fail_scsi_tasks(conn, sc->device->lun, DID_ERROR);
2334        conn->tmf_state = TMF_INITIAL;
2335        spin_unlock_bh(&session->frwd_lock);
2336
2337        iscsi_start_tx(conn);
2338        goto done;
2339
2340unlock:
2341        spin_unlock_bh(&session->frwd_lock);
2342done:
2343        ISCSI_DBG_EH(session, "dev reset result = %s\n",
2344                     rc == SUCCESS ? "SUCCESS" : "FAILED");
2345        mutex_unlock(&session->eh_mutex);
2346        return rc;
2347}
2348EXPORT_SYMBOL_GPL(iscsi_eh_device_reset);
2349
2350void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
2351{
2352        struct iscsi_session *session = cls_session->dd_data;
2353
2354        spin_lock_bh(&session->frwd_lock);
2355        if (session->state != ISCSI_STATE_LOGGED_IN) {
2356                session->state = ISCSI_STATE_RECOVERY_FAILED;
2357                if (session->leadconn)
2358                        wake_up(&session->leadconn->ehwait);
2359        }
2360        spin_unlock_bh(&session->frwd_lock);
2361}
2362EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
2363
2364/**
2365 * iscsi_eh_session_reset - drop session and attempt relogin
2366 * @sc: scsi command
2367 *
2368 * This function will wait for a relogin, session termination from
2369 * userspace, or a recovery/replacement timeout.
2370 */
2371int iscsi_eh_session_reset(struct scsi_cmnd *sc)
2372{
2373        struct iscsi_cls_session *cls_session;
2374        struct iscsi_session *session;
2375        struct iscsi_conn *conn;
2376
2377        cls_session = starget_to_session(scsi_target(sc->device));
2378        session = cls_session->dd_data;
2379        conn = session->leadconn;
2380
2381        mutex_lock(&session->eh_mutex);
2382        spin_lock_bh(&session->frwd_lock);
2383        if (session->state == ISCSI_STATE_TERMINATE) {
2384failed:
2385                ISCSI_DBG_EH(session,
2386                             "failing session reset: Could not log back into "
2387                             "%s [age %d]\n", session->targetname,
2388                             session->age);
2389                spin_unlock_bh(&session->frwd_lock);
2390                mutex_unlock(&session->eh_mutex);
2391                return FAILED;
2392        }
2393
2394        spin_unlock_bh(&session->frwd_lock);
2395        mutex_unlock(&session->eh_mutex);
2396        /*
2397         * we drop the lock here but the leadconn cannot be destoyed while
2398         * we are in the scsi eh
2399         */
2400        iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2401
2402        ISCSI_DBG_EH(session, "wait for relogin\n");
2403        wait_event_interruptible(conn->ehwait,
2404                                 session->state == ISCSI_STATE_TERMINATE ||
2405                                 session->state == ISCSI_STATE_LOGGED_IN ||
2406                                 session->state == ISCSI_STATE_RECOVERY_FAILED);
2407        if (signal_pending(current))
2408                flush_signals(current);
2409
2410        mutex_lock(&session->eh_mutex);
2411        spin_lock_bh(&session->frwd_lock);
2412        if (session->state == ISCSI_STATE_LOGGED_IN) {
2413                ISCSI_DBG_EH(session,
2414                             "session reset succeeded for %s,%s\n",
2415                             session->targetname, conn->persistent_address);
2416        } else
2417                goto failed;
2418        spin_unlock_bh(&session->frwd_lock);
2419        mutex_unlock(&session->eh_mutex);
2420        return SUCCESS;
2421}
2422EXPORT_SYMBOL_GPL(iscsi_eh_session_reset);
2423
2424static void iscsi_prep_tgt_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
2425{
2426        memset(hdr, 0, sizeof(*hdr));
2427        hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2428        hdr->flags = ISCSI_TM_FUNC_TARGET_WARM_RESET & ISCSI_FLAG_TM_FUNC_MASK;
2429        hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2430        hdr->rtt = RESERVED_ITT;
2431}
2432
2433/**
2434 * iscsi_eh_target_reset - reset target
2435 * @sc: scsi command
2436 *
2437 * This will attempt to send a warm target reset.
2438 */
2439static int iscsi_eh_target_reset(struct scsi_cmnd *sc)
2440{
2441        struct iscsi_cls_session *cls_session;
2442        struct iscsi_session *session;
2443        struct iscsi_conn *conn;
2444        struct iscsi_tm *hdr;
2445        int rc = FAILED;
2446
2447        cls_session = starget_to_session(scsi_target(sc->device));
2448        session = cls_session->dd_data;
2449
2450        ISCSI_DBG_EH(session, "tgt Reset [sc %p tgt %s]\n", sc,
2451                     session->targetname);
2452
2453        mutex_lock(&session->eh_mutex);
2454        spin_lock_bh(&session->frwd_lock);
2455        /*
2456         * Just check if we are not logged in. We cannot check for
2457         * the phase because the reset could come from a ioctl.
2458         */
2459        if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
2460                goto unlock;
2461        conn = session->leadconn;
2462
2463        /* only have one tmf outstanding at a time */
2464        if (conn->tmf_state != TMF_INITIAL)
2465                goto unlock;
2466        conn->tmf_state = TMF_QUEUED;
2467
2468        hdr = &conn->tmhdr;
2469        iscsi_prep_tgt_reset_pdu(sc, hdr);
2470
2471        if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
2472                                    session->tgt_reset_timeout)) {
2473                rc = FAILED;
2474                goto unlock;
2475        }
2476
2477        switch (conn->tmf_state) {
2478        case TMF_SUCCESS:
2479                break;
2480        case TMF_TIMEDOUT:
2481                spin_unlock_bh(&session->frwd_lock);
2482                iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2483                goto done;
2484        default:
2485                conn->tmf_state = TMF_INITIAL;
2486                goto unlock;
2487        }
2488
2489        rc = SUCCESS;
2490        spin_unlock_bh(&session->frwd_lock);
2491
2492        iscsi_suspend_tx(conn);
2493
2494        spin_lock_bh(&session->frwd_lock);
2495        memset(hdr, 0, sizeof(*hdr));
2496        fail_scsi_tasks(conn, -1, DID_ERROR);
2497        conn->tmf_state = TMF_INITIAL;
2498        spin_unlock_bh(&session->frwd_lock);
2499
2500        iscsi_start_tx(conn);
2501        goto done;
2502
2503unlock:
2504        spin_unlock_bh(&session->frwd_lock);
2505done:
2506        ISCSI_DBG_EH(session, "tgt %s reset result = %s\n", session->targetname,
2507                     rc == SUCCESS ? "SUCCESS" : "FAILED");
2508        mutex_unlock(&session->eh_mutex);
2509        return rc;
2510}
2511
2512/**
2513 * iscsi_eh_recover_target - reset target and possibly the session
2514 * @sc: scsi command
2515 *
2516 * This will attempt to send a warm target reset. If that fails,
2517 * we will escalate to ERL0 session recovery.
2518 */
2519int iscsi_eh_recover_target(struct scsi_cmnd *sc)
2520{
2521        int rc;
2522
2523        rc = iscsi_eh_target_reset(sc);
2524        if (rc == FAILED)
2525                rc = iscsi_eh_session_reset(sc);
2526        return rc;
2527}
2528EXPORT_SYMBOL_GPL(iscsi_eh_recover_target);
2529
2530/*
2531 * Pre-allocate a pool of @max items of @item_size. By default, the pool
2532 * should be accessed via kfifo_{get,put} on q->queue.
2533 * Optionally, the caller can obtain the array of object pointers
2534 * by passing in a non-NULL @items pointer
2535 */
2536int
2537iscsi_pool_init(struct iscsi_pool *q, int max, void ***items, int item_size)
2538{
2539        int i, num_arrays = 1;
2540
2541        memset(q, 0, sizeof(*q));
2542
2543        q->max = max;
2544
2545        /* If the user passed an items pointer, he wants a copy of
2546         * the array. */
2547        if (items)
2548                num_arrays++;
2549        q->pool = kvcalloc(num_arrays * max, sizeof(void *), GFP_KERNEL);
2550        if (q->pool == NULL)
2551                return -ENOMEM;
2552
2553        kfifo_init(&q->queue, (void*)q->pool, max * sizeof(void*));
2554
2555        for (i = 0; i < max; i++) {
2556                q->pool[i] = kzalloc(item_size, GFP_KERNEL);
2557                if (q->pool[i] == NULL) {
2558                        q->max = i;
2559                        goto enomem;
2560                }
2561                kfifo_in(&q->queue, (void*)&q->pool[i], sizeof(void*));
2562        }
2563
2564        if (items) {
2565                *items = q->pool + max;
2566                memcpy(*items, q->pool, max * sizeof(void *));
2567        }
2568
2569        return 0;
2570
2571enomem:
2572        iscsi_pool_free(q);
2573        return -ENOMEM;
2574}
2575EXPORT_SYMBOL_GPL(iscsi_pool_init);
2576
2577void iscsi_pool_free(struct iscsi_pool *q)
2578{
2579        int i;
2580
2581        for (i = 0; i < q->max; i++)
2582                kfree(q->pool[i]);
2583        kvfree(q->pool);
2584}
2585EXPORT_SYMBOL_GPL(iscsi_pool_free);
2586
2587/**
2588 * iscsi_host_add - add host to system
2589 * @shost: scsi host
2590 * @pdev: parent device
2591 *
2592 * This should be called by partial offload and software iscsi drivers
2593 * to add a host to the system.
2594 */
2595int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev)
2596{
2597        if (!shost->can_queue)
2598                shost->can_queue = ISCSI_DEF_XMIT_CMDS_MAX;
2599
2600        if (!shost->cmd_per_lun)
2601                shost->cmd_per_lun = ISCSI_DEF_CMD_PER_LUN;
2602
2603        return scsi_add_host(shost, pdev);
2604}
2605EXPORT_SYMBOL_GPL(iscsi_host_add);
2606
2607/**
2608 * iscsi_host_alloc - allocate a host and driver data
2609 * @sht: scsi host template
2610 * @dd_data_size: driver host data size
2611 * @xmit_can_sleep: bool indicating if LLD will queue IO from a work queue
2612 *
2613 * This should be called by partial offload and software iscsi drivers.
2614 * To access the driver specific memory use the iscsi_host_priv() macro.
2615 */
2616struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
2617                                   int dd_data_size, bool xmit_can_sleep)
2618{
2619        struct Scsi_Host *shost;
2620        struct iscsi_host *ihost;
2621
2622        shost = scsi_host_alloc(sht, sizeof(struct iscsi_host) + dd_data_size);
2623        if (!shost)
2624                return NULL;
2625        ihost = shost_priv(shost);
2626
2627        if (xmit_can_sleep) {
2628                snprintf(ihost->workq_name, sizeof(ihost->workq_name),
2629                        "iscsi_q_%d", shost->host_no);
2630                ihost->workq = create_singlethread_workqueue(ihost->workq_name);
2631                if (!ihost->workq)
2632                        goto free_host;
2633        }
2634
2635        spin_lock_init(&ihost->lock);
2636        ihost->state = ISCSI_HOST_SETUP;
2637        ihost->num_sessions = 0;
2638        init_waitqueue_head(&ihost->session_removal_wq);
2639        return shost;
2640
2641free_host:
2642        scsi_host_put(shost);
2643        return NULL;
2644}
2645EXPORT_SYMBOL_GPL(iscsi_host_alloc);
2646
2647static void iscsi_notify_host_removed(struct iscsi_cls_session *cls_session)
2648{
2649        iscsi_session_failure(cls_session->dd_data, ISCSI_ERR_INVALID_HOST);
2650}
2651
2652/**
2653 * iscsi_host_remove - remove host and sessions
2654 * @shost: scsi host
2655 *
2656 * If there are any sessions left, this will initiate the removal and wait
2657 * for the completion.
2658 */
2659void iscsi_host_remove(struct Scsi_Host *shost)
2660{
2661        struct iscsi_host *ihost = shost_priv(shost);
2662        unsigned long flags;
2663
2664        spin_lock_irqsave(&ihost->lock, flags);
2665        ihost->state = ISCSI_HOST_REMOVED;
2666        spin_unlock_irqrestore(&ihost->lock, flags);
2667
2668        iscsi_host_for_each_session(shost, iscsi_notify_host_removed);
2669        wait_event_interruptible(ihost->session_removal_wq,
2670                                 ihost->num_sessions == 0);
2671        if (signal_pending(current))
2672                flush_signals(current);
2673
2674        scsi_remove_host(shost);
2675        if (ihost->workq)
2676                destroy_workqueue(ihost->workq);
2677}
2678EXPORT_SYMBOL_GPL(iscsi_host_remove);
2679
2680void iscsi_host_free(struct Scsi_Host *shost)
2681{
2682        struct iscsi_host *ihost = shost_priv(shost);
2683
2684        kfree(ihost->netdev);
2685        kfree(ihost->hwaddress);
2686        kfree(ihost->initiatorname);
2687        scsi_host_put(shost);
2688}
2689EXPORT_SYMBOL_GPL(iscsi_host_free);
2690
2691static void iscsi_host_dec_session_cnt(struct Scsi_Host *shost)
2692{
2693        struct iscsi_host *ihost = shost_priv(shost);
2694        unsigned long flags;
2695
2696        shost = scsi_host_get(shost);
2697        if (!shost) {
2698                printk(KERN_ERR "Invalid state. Cannot notify host removal "
2699                      "of session teardown event because host already "
2700                      "removed.\n");
2701                return;
2702        }
2703
2704        spin_lock_irqsave(&ihost->lock, flags);
2705        ihost->num_sessions--;
2706        if (ihost->num_sessions == 0)
2707                wake_up(&ihost->session_removal_wq);
2708        spin_unlock_irqrestore(&ihost->lock, flags);
2709        scsi_host_put(shost);
2710}
2711
2712/**
2713 * iscsi_session_setup - create iscsi cls session and host and session
2714 * @iscsit: iscsi transport template
2715 * @shost: scsi host
2716 * @cmds_max: session can queue
2717 * @dd_size: private driver data size, added to session allocation size
2718 * @cmd_task_size: LLD task private data size
2719 * @initial_cmdsn: initial CmdSN
2720 * @id: target ID to add to this session
2721 *
2722 * This can be used by software iscsi_transports that allocate
2723 * a session per scsi host.
2724 *
2725 * Callers should set cmds_max to the largest total numer (mgmt + scsi) of
2726 * tasks they support. The iscsi layer reserves ISCSI_MGMT_CMDS_MAX tasks
2727 * for nop handling and login/logout requests.
2728 */
2729struct iscsi_cls_session *
2730iscsi_session_setup(struct iscsi_transport *iscsit, struct Scsi_Host *shost,
2731                    uint16_t cmds_max, int dd_size, int cmd_task_size,
2732                    uint32_t initial_cmdsn, unsigned int id)
2733{
2734        struct iscsi_host *ihost = shost_priv(shost);
2735        struct iscsi_session *session;
2736        struct iscsi_cls_session *cls_session;
2737        int cmd_i, scsi_cmds, total_cmds = cmds_max;
2738        unsigned long flags;
2739
2740        spin_lock_irqsave(&ihost->lock, flags);
2741        if (ihost->state == ISCSI_HOST_REMOVED) {
2742                spin_unlock_irqrestore(&ihost->lock, flags);
2743                return NULL;
2744        }
2745        ihost->num_sessions++;
2746        spin_unlock_irqrestore(&ihost->lock, flags);
2747
2748        if (!total_cmds)
2749                total_cmds = ISCSI_DEF_XMIT_CMDS_MAX;
2750        /*
2751         * The iscsi layer needs some tasks for nop handling and tmfs,
2752         * so the cmds_max must at least be greater than ISCSI_MGMT_CMDS_MAX
2753         * + 1 command for scsi IO.
2754         */
2755        if (total_cmds < ISCSI_TOTAL_CMDS_MIN) {
2756                printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2757                       "must be a power of two that is at least %d.\n",
2758                       total_cmds, ISCSI_TOTAL_CMDS_MIN);
2759                goto dec_session_count;
2760        }
2761
2762        if (total_cmds > ISCSI_TOTAL_CMDS_MAX) {
2763                printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2764                       "must be a power of 2 less than or equal to %d.\n",
2765                       cmds_max, ISCSI_TOTAL_CMDS_MAX);
2766                total_cmds = ISCSI_TOTAL_CMDS_MAX;
2767        }
2768
2769        if (!is_power_of_2(total_cmds)) {
2770                printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2771                       "must be a power of 2.\n", total_cmds);
2772                total_cmds = rounddown_pow_of_two(total_cmds);
2773                if (total_cmds < ISCSI_TOTAL_CMDS_MIN)
2774                        return NULL;
2775                printk(KERN_INFO "iscsi: Rounding can_queue to %d.\n",
2776                       total_cmds);
2777        }
2778        scsi_cmds = total_cmds - ISCSI_MGMT_CMDS_MAX;
2779
2780        cls_session = iscsi_alloc_session(shost, iscsit,
2781                                          sizeof(struct iscsi_session) +
2782                                          dd_size);
2783        if (!cls_session)
2784                goto dec_session_count;
2785        session = cls_session->dd_data;
2786        session->cls_session = cls_session;
2787        session->host = shost;
2788        session->state = ISCSI_STATE_FREE;
2789        session->fast_abort = 1;
2790        session->tgt_reset_timeout = 30;
2791        session->lu_reset_timeout = 15;
2792        session->abort_timeout = 10;
2793        session->scsi_cmds_max = scsi_cmds;
2794        session->cmds_max = total_cmds;
2795        session->queued_cmdsn = session->cmdsn = initial_cmdsn;
2796        session->exp_cmdsn = initial_cmdsn + 1;
2797        session->max_cmdsn = initial_cmdsn + 1;
2798        session->max_r2t = 1;
2799        session->tt = iscsit;
2800        session->dd_data = cls_session->dd_data + sizeof(*session);
2801
2802        mutex_init(&session->eh_mutex);
2803        spin_lock_init(&session->frwd_lock);
2804        spin_lock_init(&session->back_lock);
2805
2806        /* initialize SCSI PDU commands pool */
2807        if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
2808                            (void***)&session->cmds,
2809                            cmd_task_size + sizeof(struct iscsi_task)))
2810                goto cmdpool_alloc_fail;
2811
2812        /* pre-format cmds pool with ITT */
2813        for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
2814                struct iscsi_task *task = session->cmds[cmd_i];
2815
2816                if (cmd_task_size)
2817                        task->dd_data = &task[1];
2818                task->itt = cmd_i;
2819                task->state = ISCSI_TASK_FREE;
2820                INIT_LIST_HEAD(&task->running);
2821        }
2822
2823        if (!try_module_get(iscsit->owner))
2824                goto module_get_fail;
2825
2826        if (iscsi_add_session(cls_session, id))
2827                goto cls_session_fail;
2828
2829        return cls_session;
2830
2831cls_session_fail:
2832        module_put(iscsit->owner);
2833module_get_fail:
2834        iscsi_pool_free(&session->cmdpool);
2835cmdpool_alloc_fail:
2836        iscsi_free_session(cls_session);
2837dec_session_count:
2838        iscsi_host_dec_session_cnt(shost);
2839        return NULL;
2840}
2841EXPORT_SYMBOL_GPL(iscsi_session_setup);
2842
2843/**
2844 * iscsi_session_teardown - destroy session, host, and cls_session
2845 * @cls_session: iscsi session
2846 */
2847void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
2848{
2849        struct iscsi_session *session = cls_session->dd_data;
2850        struct module *owner = cls_session->transport->owner;
2851        struct Scsi_Host *shost = session->host;
2852
2853        iscsi_pool_free(&session->cmdpool);
2854
2855        iscsi_remove_session(cls_session);
2856
2857        kfree(session->password);
2858        kfree(session->password_in);
2859        kfree(session->username);
2860        kfree(session->username_in);
2861        kfree(session->targetname);
2862        kfree(session->targetalias);
2863        kfree(session->initiatorname);
2864        kfree(session->boot_root);
2865        kfree(session->boot_nic);
2866        kfree(session->boot_target);
2867        kfree(session->ifacename);
2868        kfree(session->portal_type);
2869        kfree(session->discovery_parent_type);
2870
2871        iscsi_free_session(cls_session);
2872
2873        iscsi_host_dec_session_cnt(shost);
2874        module_put(owner);
2875}
2876EXPORT_SYMBOL_GPL(iscsi_session_teardown);
2877
2878/**
2879 * iscsi_conn_setup - create iscsi_cls_conn and iscsi_conn
2880 * @cls_session: iscsi_cls_session
2881 * @dd_size: private driver data size
2882 * @conn_idx: cid
2883 */
2884struct iscsi_cls_conn *
2885iscsi_conn_setup(struct iscsi_cls_session *cls_session, int dd_size,
2886                 uint32_t conn_idx)
2887{
2888        struct iscsi_session *session = cls_session->dd_data;
2889        struct iscsi_conn *conn;
2890        struct iscsi_cls_conn *cls_conn;
2891        char *data;
2892
2893        cls_conn = iscsi_create_conn(cls_session, sizeof(*conn) + dd_size,
2894                                     conn_idx);
2895        if (!cls_conn)
2896                return NULL;
2897        conn = cls_conn->dd_data;
2898        memset(conn, 0, sizeof(*conn) + dd_size);
2899
2900        conn->dd_data = cls_conn->dd_data + sizeof(*conn);
2901        conn->session = session;
2902        conn->cls_conn = cls_conn;
2903        conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
2904        conn->id = conn_idx;
2905        conn->exp_statsn = 0;
2906        conn->tmf_state = TMF_INITIAL;
2907
2908        timer_setup(&conn->transport_timer, iscsi_check_transport_timeouts, 0);
2909
2910        INIT_LIST_HEAD(&conn->mgmtqueue);
2911        INIT_LIST_HEAD(&conn->cmdqueue);
2912        INIT_LIST_HEAD(&conn->requeue);
2913        spin_lock_init(&conn->taskqueuelock);
2914        INIT_WORK(&conn->xmitwork, iscsi_xmitworker);
2915
2916        /* allocate login_task used for the login/text sequences */
2917        spin_lock_bh(&session->frwd_lock);
2918        if (!kfifo_out(&session->cmdpool.queue,
2919                         (void*)&conn->login_task,
2920                         sizeof(void*))) {
2921                spin_unlock_bh(&session->frwd_lock);
2922                goto login_task_alloc_fail;
2923        }
2924        spin_unlock_bh(&session->frwd_lock);
2925
2926        data = (char *) __get_free_pages(GFP_KERNEL,
2927                                         get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
2928        if (!data)
2929                goto login_task_data_alloc_fail;
2930        conn->login_task->data = conn->data = data;
2931
2932        timer_setup(&conn->tmf_timer, iscsi_tmf_timedout, 0);
2933        init_waitqueue_head(&conn->ehwait);
2934
2935        return cls_conn;
2936
2937login_task_data_alloc_fail:
2938        kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
2939                    sizeof(void*));
2940login_task_alloc_fail:
2941        iscsi_destroy_conn(cls_conn);
2942        return NULL;
2943}
2944EXPORT_SYMBOL_GPL(iscsi_conn_setup);
2945
2946/**
2947 * iscsi_conn_teardown - teardown iscsi connection
2948 * @cls_conn: iscsi class connection
2949 *
2950 * TODO: we may need to make this into a two step process
2951 * like scsi-mls remove + put host
2952 */
2953void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
2954{
2955        struct iscsi_conn *conn = cls_conn->dd_data;
2956        struct iscsi_session *session = conn->session;
2957
2958        del_timer_sync(&conn->transport_timer);
2959
2960        mutex_lock(&session->eh_mutex);
2961        spin_lock_bh(&session->frwd_lock);
2962        conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
2963        if (session->leadconn == conn) {
2964                /*
2965                 * leading connection? then give up on recovery.
2966                 */
2967                session->state = ISCSI_STATE_TERMINATE;
2968                wake_up(&conn->ehwait);
2969        }
2970        spin_unlock_bh(&session->frwd_lock);
2971
2972        /* flush queued up work because we free the connection below */
2973        iscsi_suspend_tx(conn);
2974
2975        spin_lock_bh(&session->frwd_lock);
2976        free_pages((unsigned long) conn->data,
2977                   get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
2978        kfree(conn->persistent_address);
2979        kfree(conn->local_ipaddr);
2980        /* regular RX path uses back_lock */
2981        spin_lock_bh(&session->back_lock);
2982        kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
2983                    sizeof(void*));
2984        spin_unlock_bh(&session->back_lock);
2985        if (session->leadconn == conn)
2986                session->leadconn = NULL;
2987        spin_unlock_bh(&session->frwd_lock);
2988        mutex_unlock(&session->eh_mutex);
2989
2990        iscsi_destroy_conn(cls_conn);
2991}
2992EXPORT_SYMBOL_GPL(iscsi_conn_teardown);
2993
2994int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
2995{
2996        struct iscsi_conn *conn = cls_conn->dd_data;
2997        struct iscsi_session *session = conn->session;
2998
2999        if (!session) {
3000                iscsi_conn_printk(KERN_ERR, conn,
3001                                  "can't start unbound connection\n");
3002                return -EPERM;
3003        }
3004
3005        if ((session->imm_data_en || !session->initial_r2t_en) &&
3006             session->first_burst > session->max_burst) {
3007                iscsi_conn_printk(KERN_INFO, conn, "invalid burst lengths: "
3008                                  "first_burst %d max_burst %d\n",
3009                                  session->first_burst, session->max_burst);
3010                return -EINVAL;
3011        }
3012
3013        if (conn->ping_timeout && !conn->recv_timeout) {
3014                iscsi_conn_printk(KERN_ERR, conn, "invalid recv timeout of "
3015                                  "zero. Using 5 seconds\n.");
3016                conn->recv_timeout = 5;
3017        }
3018
3019        if (conn->recv_timeout && !conn->ping_timeout) {
3020                iscsi_conn_printk(KERN_ERR, conn, "invalid ping timeout of "
3021                                  "zero. Using 5 seconds.\n");
3022                conn->ping_timeout = 5;
3023        }
3024
3025        spin_lock_bh(&session->frwd_lock);
3026        conn->c_stage = ISCSI_CONN_STARTED;
3027        session->state = ISCSI_STATE_LOGGED_IN;
3028        session->queued_cmdsn = session->cmdsn;
3029
3030        conn->last_recv = jiffies;
3031        conn->last_ping = jiffies;
3032        if (conn->recv_timeout && conn->ping_timeout)
3033                mod_timer(&conn->transport_timer,
3034                          jiffies + (conn->recv_timeout * HZ));
3035
3036        switch(conn->stop_stage) {
3037        case STOP_CONN_RECOVER:
3038                /*
3039                 * unblock eh_abort() if it is blocked. re-try all
3040                 * commands after successful recovery
3041                 */
3042                conn->stop_stage = 0;
3043                conn->tmf_state = TMF_INITIAL;
3044                session->age++;
3045                if (session->age == 16)
3046                        session->age = 0;
3047                break;
3048        case STOP_CONN_TERM:
3049                conn->stop_stage = 0;
3050                break;
3051        default:
3052                break;
3053        }
3054        spin_unlock_bh(&session->frwd_lock);
3055
3056        iscsi_unblock_session(session->cls_session);
3057        wake_up(&conn->ehwait);
3058        return 0;
3059}
3060EXPORT_SYMBOL_GPL(iscsi_conn_start);
3061
3062static void
3063fail_mgmt_tasks(struct iscsi_session *session, struct iscsi_conn *conn)
3064{
3065        struct iscsi_task *task;
3066        int i, state;
3067
3068        for (i = 0; i < conn->session->cmds_max; i++) {
3069                task = conn->session->cmds[i];
3070                if (task->sc)
3071                        continue;
3072
3073                if (task->state == ISCSI_TASK_FREE)
3074                        continue;
3075
3076                ISCSI_DBG_SESSION(conn->session,
3077                                  "failing mgmt itt 0x%x state %d\n",
3078                                  task->itt, task->state);
3079                state = ISCSI_TASK_ABRT_SESS_RECOV;
3080                if (task->state == ISCSI_TASK_PENDING)
3081                        state = ISCSI_TASK_COMPLETED;
3082                spin_lock_bh(&session->back_lock);
3083                iscsi_complete_task(task, state);
3084                spin_unlock_bh(&session->back_lock);
3085        }
3086}
3087
3088static void iscsi_start_session_recovery(struct iscsi_session *session,
3089                                         struct iscsi_conn *conn, int flag)
3090{
3091        int old_stop_stage;
3092
3093        mutex_lock(&session->eh_mutex);
3094        spin_lock_bh(&session->frwd_lock);
3095        if (conn->stop_stage == STOP_CONN_TERM) {
3096                spin_unlock_bh(&session->frwd_lock);
3097                mutex_unlock(&session->eh_mutex);
3098                return;
3099        }
3100
3101        /*
3102         * When this is called for the in_login state, we only want to clean
3103         * up the login task and connection. We do not need to block and set
3104         * the recovery state again
3105         */
3106        if (flag == STOP_CONN_TERM)
3107                session->state = ISCSI_STATE_TERMINATE;
3108        else if (conn->stop_stage != STOP_CONN_RECOVER)
3109                session->state = ISCSI_STATE_IN_RECOVERY;
3110
3111        old_stop_stage = conn->stop_stage;
3112        conn->stop_stage = flag;
3113        spin_unlock_bh(&session->frwd_lock);
3114
3115        del_timer_sync(&conn->transport_timer);
3116        iscsi_suspend_tx(conn);
3117
3118        spin_lock_bh(&session->frwd_lock);
3119        conn->c_stage = ISCSI_CONN_STOPPED;
3120        spin_unlock_bh(&session->frwd_lock);
3121
3122        /*
3123         * for connection level recovery we should not calculate
3124         * header digest. conn->hdr_size used for optimization
3125         * in hdr_extract() and will be re-negotiated at
3126         * set_param() time.
3127         */
3128        if (flag == STOP_CONN_RECOVER) {
3129                conn->hdrdgst_en = 0;
3130                conn->datadgst_en = 0;
3131                if (session->state == ISCSI_STATE_IN_RECOVERY &&
3132                    old_stop_stage != STOP_CONN_RECOVER) {
3133                        ISCSI_DBG_SESSION(session, "blocking session\n");
3134                        iscsi_block_session(session->cls_session);
3135                }
3136        }
3137
3138        /*
3139         * flush queues.
3140         */
3141        spin_lock_bh(&session->frwd_lock);
3142        fail_scsi_tasks(conn, -1, DID_TRANSPORT_DISRUPTED);
3143        fail_mgmt_tasks(session, conn);
3144        memset(&conn->tmhdr, 0, sizeof(conn->tmhdr));
3145        spin_unlock_bh(&session->frwd_lock);
3146        mutex_unlock(&session->eh_mutex);
3147}
3148
3149void iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
3150{
3151        struct iscsi_conn *conn = cls_conn->dd_data;
3152        struct iscsi_session *session = conn->session;
3153
3154        switch (flag) {
3155        case STOP_CONN_RECOVER:
3156        case STOP_CONN_TERM:
3157                iscsi_start_session_recovery(session, conn, flag);
3158                break;
3159        default:
3160                iscsi_conn_printk(KERN_ERR, conn,
3161                                  "invalid stop flag %d\n", flag);
3162        }
3163}
3164EXPORT_SYMBOL_GPL(iscsi_conn_stop);
3165
3166int iscsi_conn_bind(struct iscsi_cls_session *cls_session,
3167                    struct iscsi_cls_conn *cls_conn, int is_leading)
3168{
3169        struct iscsi_session *session = cls_session->dd_data;
3170        struct iscsi_conn *conn = cls_conn->dd_data;
3171
3172        spin_lock_bh(&session->frwd_lock);
3173        if (is_leading)
3174                session->leadconn = conn;
3175        spin_unlock_bh(&session->frwd_lock);
3176
3177        /*
3178         * Unblock xmitworker(), Login Phase will pass through.
3179         */
3180        clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
3181        clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
3182        return 0;
3183}
3184EXPORT_SYMBOL_GPL(iscsi_conn_bind);
3185
3186int iscsi_switch_str_param(char **param, char *new_val_buf)
3187{
3188        char *new_val;
3189
3190        if (*param) {
3191                if (!strcmp(*param, new_val_buf))
3192                        return 0;
3193        }
3194
3195        new_val = kstrdup(new_val_buf, GFP_NOIO);
3196        if (!new_val)
3197                return -ENOMEM;
3198
3199        kfree(*param);
3200        *param = new_val;
3201        return 0;
3202}
3203EXPORT_SYMBOL_GPL(iscsi_switch_str_param);
3204
3205int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
3206                    enum iscsi_param param, char *buf, int buflen)
3207{
3208        struct iscsi_conn *conn = cls_conn->dd_data;
3209        struct iscsi_session *session = conn->session;
3210        int val;
3211
3212        switch(param) {
3213        case ISCSI_PARAM_FAST_ABORT:
3214                sscanf(buf, "%d", &session->fast_abort);
3215                break;
3216        case ISCSI_PARAM_ABORT_TMO:
3217                sscanf(buf, "%d", &session->abort_timeout);
3218                break;
3219        case ISCSI_PARAM_LU_RESET_TMO:
3220                sscanf(buf, "%d", &session->lu_reset_timeout);
3221                break;
3222        case ISCSI_PARAM_TGT_RESET_TMO:
3223                sscanf(buf, "%d", &session->tgt_reset_timeout);
3224                break;
3225        case ISCSI_PARAM_PING_TMO:
3226                sscanf(buf, "%d", &conn->ping_timeout);
3227                break;
3228        case ISCSI_PARAM_RECV_TMO:
3229                sscanf(buf, "%d", &conn->recv_timeout);
3230                break;
3231        case ISCSI_PARAM_MAX_RECV_DLENGTH:
3232                sscanf(buf, "%d", &conn->max_recv_dlength);
3233                break;
3234        case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3235                sscanf(buf, "%d", &conn->max_xmit_dlength);
3236                break;
3237        case ISCSI_PARAM_HDRDGST_EN:
3238                sscanf(buf, "%d", &conn->hdrdgst_en);
3239                break;
3240        case ISCSI_PARAM_DATADGST_EN:
3241                sscanf(buf, "%d", &conn->datadgst_en);
3242                break;
3243        case ISCSI_PARAM_INITIAL_R2T_EN:
3244                sscanf(buf, "%d", &session->initial_r2t_en);
3245                break;
3246        case ISCSI_PARAM_MAX_R2T:
3247                sscanf(buf, "%hu", &session->max_r2t);
3248                break;
3249        case ISCSI_PARAM_IMM_DATA_EN:
3250                sscanf(buf, "%d", &session->imm_data_en);
3251                break;
3252        case ISCSI_PARAM_FIRST_BURST:
3253                sscanf(buf, "%d", &session->first_burst);
3254                break;
3255        case ISCSI_PARAM_MAX_BURST:
3256                sscanf(buf, "%d", &session->max_burst);
3257                break;
3258        case ISCSI_PARAM_PDU_INORDER_EN:
3259                sscanf(buf, "%d", &session->pdu_inorder_en);
3260                break;
3261        case ISCSI_PARAM_DATASEQ_INORDER_EN:
3262                sscanf(buf, "%d", &session->dataseq_inorder_en);
3263                break;
3264        case ISCSI_PARAM_ERL:
3265                sscanf(buf, "%d", &session->erl);
3266                break;
3267        case ISCSI_PARAM_EXP_STATSN:
3268                sscanf(buf, "%u", &conn->exp_statsn);
3269                break;
3270        case ISCSI_PARAM_USERNAME:
3271                return iscsi_switch_str_param(&session->username, buf);
3272        case ISCSI_PARAM_USERNAME_IN:
3273                return iscsi_switch_str_param(&session->username_in, buf);
3274        case ISCSI_PARAM_PASSWORD:
3275                return iscsi_switch_str_param(&session->password, buf);
3276        case ISCSI_PARAM_PASSWORD_IN:
3277                return iscsi_switch_str_param(&session->password_in, buf);
3278        case ISCSI_PARAM_TARGET_NAME:
3279                return iscsi_switch_str_param(&session->targetname, buf);
3280        case ISCSI_PARAM_TARGET_ALIAS:
3281                return iscsi_switch_str_param(&session->targetalias, buf);
3282        case ISCSI_PARAM_TPGT:
3283                sscanf(buf, "%d", &session->tpgt);
3284                break;
3285        case ISCSI_PARAM_PERSISTENT_PORT:
3286                sscanf(buf, "%d", &conn->persistent_port);
3287                break;
3288        case ISCSI_PARAM_PERSISTENT_ADDRESS:
3289                return iscsi_switch_str_param(&conn->persistent_address, buf);
3290        case ISCSI_PARAM_IFACE_NAME:
3291                return iscsi_switch_str_param(&session->ifacename, buf);
3292        case ISCSI_PARAM_INITIATOR_NAME:
3293                return iscsi_switch_str_param(&session->initiatorname, buf);
3294        case ISCSI_PARAM_BOOT_ROOT:
3295                return iscsi_switch_str_param(&session->boot_root, buf);
3296        case ISCSI_PARAM_BOOT_NIC:
3297                return iscsi_switch_str_param(&session->boot_nic, buf);
3298        case ISCSI_PARAM_BOOT_TARGET:
3299                return iscsi_switch_str_param(&session->boot_target, buf);
3300        case ISCSI_PARAM_PORTAL_TYPE:
3301                return iscsi_switch_str_param(&session->portal_type, buf);
3302        case ISCSI_PARAM_DISCOVERY_PARENT_TYPE:
3303                return iscsi_switch_str_param(&session->discovery_parent_type,
3304                                              buf);
3305        case ISCSI_PARAM_DISCOVERY_SESS:
3306                sscanf(buf, "%d", &val);
3307                session->discovery_sess = !!val;
3308                break;
3309        case ISCSI_PARAM_LOCAL_IPADDR:
3310                return iscsi_switch_str_param(&conn->local_ipaddr, buf);
3311        default:
3312                return -ENOSYS;
3313        }
3314
3315        return 0;
3316}
3317EXPORT_SYMBOL_GPL(iscsi_set_param);
3318
3319int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
3320                            enum iscsi_param param, char *buf)
3321{
3322        struct iscsi_session *session = cls_session->dd_data;
3323        int len;
3324
3325        switch(param) {
3326        case ISCSI_PARAM_FAST_ABORT:
3327                len = sprintf(buf, "%d\n", session->fast_abort);
3328                break;
3329        case ISCSI_PARAM_ABORT_TMO:
3330                len = sprintf(buf, "%d\n", session->abort_timeout);
3331                break;
3332        case ISCSI_PARAM_LU_RESET_TMO:
3333                len = sprintf(buf, "%d\n", session->lu_reset_timeout);
3334                break;
3335        case ISCSI_PARAM_TGT_RESET_TMO:
3336                len = sprintf(buf, "%d\n", session->tgt_reset_timeout);
3337                break;
3338        case ISCSI_PARAM_INITIAL_R2T_EN:
3339                len = sprintf(buf, "%d\n", session->initial_r2t_en);
3340                break;
3341        case ISCSI_PARAM_MAX_R2T:
3342                len = sprintf(buf, "%hu\n", session->max_r2t);
3343                break;
3344        case ISCSI_PARAM_IMM_DATA_EN:
3345                len = sprintf(buf, "%d\n", session->imm_data_en);
3346                break;
3347        case ISCSI_PARAM_FIRST_BURST:
3348                len = sprintf(buf, "%u\n", session->first_burst);
3349                break;
3350        case ISCSI_PARAM_MAX_BURST:
3351                len = sprintf(buf, "%u\n", session->max_burst);
3352                break;
3353        case ISCSI_PARAM_PDU_INORDER_EN:
3354                len = sprintf(buf, "%d\n", session->pdu_inorder_en);
3355                break;
3356        case ISCSI_PARAM_DATASEQ_INORDER_EN:
3357                len = sprintf(buf, "%d\n", session->dataseq_inorder_en);
3358                break;
3359        case ISCSI_PARAM_DEF_TASKMGMT_TMO:
3360                len = sprintf(buf, "%d\n", session->def_taskmgmt_tmo);
3361                break;
3362        case ISCSI_PARAM_ERL:
3363                len = sprintf(buf, "%d\n", session->erl);
3364                break;
3365        case ISCSI_PARAM_TARGET_NAME:
3366                len = sprintf(buf, "%s\n", session->targetname);
3367                break;
3368        case ISCSI_PARAM_TARGET_ALIAS:
3369                len = sprintf(buf, "%s\n", session->targetalias);
3370                break;
3371        case ISCSI_PARAM_TPGT:
3372                len = sprintf(buf, "%d\n", session->tpgt);
3373                break;
3374        case ISCSI_PARAM_USERNAME:
3375                len = sprintf(buf, "%s\n", session->username);
3376                break;
3377        case ISCSI_PARAM_USERNAME_IN:
3378                len = sprintf(buf, "%s\n", session->username_in);
3379                break;
3380        case ISCSI_PARAM_PASSWORD:
3381                len = sprintf(buf, "%s\n", session->password);
3382                break;
3383        case ISCSI_PARAM_PASSWORD_IN:
3384                len = sprintf(buf, "%s\n", session->password_in);
3385                break;
3386        case ISCSI_PARAM_IFACE_NAME:
3387                len = sprintf(buf, "%s\n", session->ifacename);
3388                break;
3389        case ISCSI_PARAM_INITIATOR_NAME:
3390                len = sprintf(buf, "%s\n", session->initiatorname);
3391                break;
3392        case ISCSI_PARAM_BOOT_ROOT:
3393                len = sprintf(buf, "%s\n", session->boot_root);
3394                break;
3395        case ISCSI_PARAM_BOOT_NIC:
3396                len = sprintf(buf, "%s\n", session->boot_nic);
3397                break;
3398        case ISCSI_PARAM_BOOT_TARGET:
3399                len = sprintf(buf, "%s\n", session->boot_target);
3400                break;
3401        case ISCSI_PARAM_AUTO_SND_TGT_DISABLE:
3402                len = sprintf(buf, "%u\n", session->auto_snd_tgt_disable);
3403                break;
3404        case ISCSI_PARAM_DISCOVERY_SESS:
3405                len = sprintf(buf, "%u\n", session->discovery_sess);
3406                break;
3407        case ISCSI_PARAM_PORTAL_TYPE:
3408                len = sprintf(buf, "%s\n", session->portal_type);
3409                break;
3410        case ISCSI_PARAM_CHAP_AUTH_EN:
3411                len = sprintf(buf, "%u\n", session->chap_auth_en);
3412                break;
3413        case ISCSI_PARAM_DISCOVERY_LOGOUT_EN:
3414                len = sprintf(buf, "%u\n", session->discovery_logout_en);
3415                break;
3416        case ISCSI_PARAM_BIDI_CHAP_EN:
3417                len = sprintf(buf, "%u\n", session->bidi_chap_en);
3418                break;
3419        case ISCSI_PARAM_DISCOVERY_AUTH_OPTIONAL:
3420                len = sprintf(buf, "%u\n", session->discovery_auth_optional);
3421                break;
3422        case ISCSI_PARAM_DEF_TIME2WAIT:
3423                len = sprintf(buf, "%d\n", session->time2wait);
3424                break;
3425        case ISCSI_PARAM_DEF_TIME2RETAIN:
3426                len = sprintf(buf, "%d\n", session->time2retain);
3427                break;
3428        case ISCSI_PARAM_TSID:
3429                len = sprintf(buf, "%u\n", session->tsid);
3430                break;
3431        case ISCSI_PARAM_ISID:
3432                len = sprintf(buf, "%02x%02x%02x%02x%02x%02x\n",
3433                              session->isid[0], session->isid[1],
3434                              session->isid[2], session->isid[3],
3435                              session->isid[4], session->isid[5]);
3436                break;
3437        case ISCSI_PARAM_DISCOVERY_PARENT_IDX:
3438                len = sprintf(buf, "%u\n", session->discovery_parent_idx);
3439                break;
3440        case ISCSI_PARAM_DISCOVERY_PARENT_TYPE:
3441                if (session->discovery_parent_type)
3442                        len = sprintf(buf, "%s\n",
3443                                      session->discovery_parent_type);
3444                else
3445                        len = sprintf(buf, "\n");
3446                break;
3447        default:
3448                return -ENOSYS;
3449        }
3450
3451        return len;
3452}
3453EXPORT_SYMBOL_GPL(iscsi_session_get_param);
3454
3455int iscsi_conn_get_addr_param(struct sockaddr_storage *addr,
3456                              enum iscsi_param param, char *buf)
3457{
3458        struct sockaddr_in6 *sin6 = NULL;
3459        struct sockaddr_in *sin = NULL;
3460        int len;
3461
3462        switch (addr->ss_family) {
3463        case AF_INET:
3464                sin = (struct sockaddr_in *)addr;
3465                break;
3466        case AF_INET6:
3467                sin6 = (struct sockaddr_in6 *)addr;
3468                break;
3469        default:
3470                return -EINVAL;
3471        }
3472
3473        switch (param) {
3474        case ISCSI_PARAM_CONN_ADDRESS:
3475        case ISCSI_HOST_PARAM_IPADDRESS:
3476                if (sin)
3477                        len = sprintf(buf, "%pI4\n", &sin->sin_addr.s_addr);
3478                else
3479                        len = sprintf(buf, "%pI6\n", &sin6->sin6_addr);
3480                break;
3481        case ISCSI_PARAM_CONN_PORT:
3482        case ISCSI_PARAM_LOCAL_PORT:
3483                if (sin)
3484                        len = sprintf(buf, "%hu\n", be16_to_cpu(sin->sin_port));
3485                else
3486                        len = sprintf(buf, "%hu\n",
3487                                      be16_to_cpu(sin6->sin6_port));
3488                break;
3489        default:
3490                return -EINVAL;
3491        }
3492
3493        return len;
3494}
3495EXPORT_SYMBOL_GPL(iscsi_conn_get_addr_param);
3496
3497int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
3498                         enum iscsi_param param, char *buf)
3499{
3500        struct iscsi_conn *conn = cls_conn->dd_data;
3501        int len;
3502
3503        switch(param) {
3504        case ISCSI_PARAM_PING_TMO:
3505                len = sprintf(buf, "%u\n", conn->ping_timeout);
3506                break;
3507        case ISCSI_PARAM_RECV_TMO:
3508                len = sprintf(buf, "%u\n", conn->recv_timeout);
3509                break;
3510        case ISCSI_PARAM_MAX_RECV_DLENGTH:
3511                len = sprintf(buf, "%u\n", conn->max_recv_dlength);
3512                break;
3513        case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3514                len = sprintf(buf, "%u\n", conn->max_xmit_dlength);
3515                break;
3516        case ISCSI_PARAM_HDRDGST_EN:
3517                len = sprintf(buf, "%d\n", conn->hdrdgst_en);
3518                break;
3519        case ISCSI_PARAM_DATADGST_EN:
3520                len = sprintf(buf, "%d\n", conn->datadgst_en);
3521                break;
3522        case ISCSI_PARAM_IFMARKER_EN:
3523                len = sprintf(buf, "%d\n", conn->ifmarker_en);
3524                break;
3525        case ISCSI_PARAM_OFMARKER_EN:
3526                len = sprintf(buf, "%d\n", conn->ofmarker_en);
3527                break;
3528        case ISCSI_PARAM_EXP_STATSN:
3529                len = sprintf(buf, "%u\n", conn->exp_statsn);
3530                break;
3531        case ISCSI_PARAM_PERSISTENT_PORT:
3532                len = sprintf(buf, "%d\n", conn->persistent_port);
3533                break;
3534        case ISCSI_PARAM_PERSISTENT_ADDRESS:
3535                len = sprintf(buf, "%s\n", conn->persistent_address);
3536                break;
3537        case ISCSI_PARAM_STATSN:
3538                len = sprintf(buf, "%u\n", conn->statsn);
3539                break;
3540        case ISCSI_PARAM_MAX_SEGMENT_SIZE:
3541                len = sprintf(buf, "%u\n", conn->max_segment_size);
3542                break;
3543        case ISCSI_PARAM_KEEPALIVE_TMO:
3544                len = sprintf(buf, "%u\n", conn->keepalive_tmo);
3545                break;
3546        case ISCSI_PARAM_LOCAL_PORT:
3547                len = sprintf(buf, "%u\n", conn->local_port);
3548                break;
3549        case ISCSI_PARAM_TCP_TIMESTAMP_STAT:
3550                len = sprintf(buf, "%u\n", conn->tcp_timestamp_stat);
3551                break;
3552        case ISCSI_PARAM_TCP_NAGLE_DISABLE:
3553                len = sprintf(buf, "%u\n", conn->tcp_nagle_disable);
3554                break;
3555        case ISCSI_PARAM_TCP_WSF_DISABLE:
3556                len = sprintf(buf, "%u\n", conn->tcp_wsf_disable);
3557                break;
3558        case ISCSI_PARAM_TCP_TIMER_SCALE:
3559                len = sprintf(buf, "%u\n", conn->tcp_timer_scale);
3560                break;
3561        case ISCSI_PARAM_TCP_TIMESTAMP_EN:
3562                len = sprintf(buf, "%u\n", conn->tcp_timestamp_en);
3563                break;
3564        case ISCSI_PARAM_IP_FRAGMENT_DISABLE:
3565                len = sprintf(buf, "%u\n", conn->fragment_disable);
3566                break;
3567        case ISCSI_PARAM_IPV4_TOS:
3568                len = sprintf(buf, "%u\n", conn->ipv4_tos);
3569                break;
3570        case ISCSI_PARAM_IPV6_TC:
3571                len = sprintf(buf, "%u\n", conn->ipv6_traffic_class);
3572                break;
3573        case ISCSI_PARAM_IPV6_FLOW_LABEL:
3574                len = sprintf(buf, "%u\n", conn->ipv6_flow_label);
3575                break;
3576        case ISCSI_PARAM_IS_FW_ASSIGNED_IPV6:
3577                len = sprintf(buf, "%u\n", conn->is_fw_assigned_ipv6);
3578                break;
3579        case ISCSI_PARAM_TCP_XMIT_WSF:
3580                len = sprintf(buf, "%u\n", conn->tcp_xmit_wsf);
3581                break;
3582        case ISCSI_PARAM_TCP_RECV_WSF:
3583                len = sprintf(buf, "%u\n", conn->tcp_recv_wsf);
3584                break;
3585        case ISCSI_PARAM_LOCAL_IPADDR:
3586                len = sprintf(buf, "%s\n", conn->local_ipaddr);
3587                break;
3588        default:
3589                return -ENOSYS;
3590        }
3591
3592        return len;
3593}
3594EXPORT_SYMBOL_GPL(iscsi_conn_get_param);
3595
3596int iscsi_host_get_param(struct Scsi_Host *shost, enum iscsi_host_param param,
3597                         char *buf)
3598{
3599        struct iscsi_host *ihost = shost_priv(shost);
3600        int len;
3601
3602        switch (param) {
3603        case ISCSI_HOST_PARAM_NETDEV_NAME:
3604                len = sprintf(buf, "%s\n", ihost->netdev);
3605                break;
3606        case ISCSI_HOST_PARAM_HWADDRESS:
3607                len = sprintf(buf, "%s\n", ihost->hwaddress);
3608                break;
3609        case ISCSI_HOST_PARAM_INITIATOR_NAME:
3610                len = sprintf(buf, "%s\n", ihost->initiatorname);
3611                break;
3612        default:
3613                return -ENOSYS;
3614        }
3615
3616        return len;
3617}
3618EXPORT_SYMBOL_GPL(iscsi_host_get_param);
3619
3620int iscsi_host_set_param(struct Scsi_Host *shost, enum iscsi_host_param param,
3621                         char *buf, int buflen)
3622{
3623        struct iscsi_host *ihost = shost_priv(shost);
3624
3625        switch (param) {
3626        case ISCSI_HOST_PARAM_NETDEV_NAME:
3627                return iscsi_switch_str_param(&ihost->netdev, buf);
3628        case ISCSI_HOST_PARAM_HWADDRESS:
3629                return iscsi_switch_str_param(&ihost->hwaddress, buf);
3630        case ISCSI_HOST_PARAM_INITIATOR_NAME:
3631                return iscsi_switch_str_param(&ihost->initiatorname, buf);
3632        default:
3633                return -ENOSYS;
3634        }
3635
3636        return 0;
3637}
3638EXPORT_SYMBOL_GPL(iscsi_host_set_param);
3639
3640MODULE_AUTHOR("Mike Christie");
3641MODULE_DESCRIPTION("iSCSI library functions");
3642MODULE_LICENSE("GPL");
3643