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_session *session = task->conn->session;
 234        struct iscsi_tm *tmf = &session->tmhdr;
 235        u64 hdr_lun;
 236
 237        if (session->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                fallthrough;
 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_session_printk(KERN_INFO, session,
 258                                             "task [op %x itt 0x%x/0x%x] rejected.\n",
 259                                             opcode, task->itt, task->hdr_itt);
 260                        return -EACCES;
 261                }
 262                /*
 263                 * And also all data-out PDUs in response to R2T
 264                 * if fast_abort is set.
 265                 */
 266                if (session->fast_abort) {
 267                        iscsi_session_printk(KERN_INFO, session,
 268                                             "task [op %x itt 0x%x/0x%x] fast abort.\n",
 269                                             opcode, task->itt, task->hdr_itt);
 270                        return -EACCES;
 271                }
 272                break;
 273        case ISCSI_TM_FUNC_ABORT_TASK:
 274                /*
 275                 * the caller has already checked if the task
 276                 * they want to abort was in the pending queue so if
 277                 * we are here the cmd pdu has gone out already, and
 278                 * we will only hit this for data-outs
 279                 */
 280                if (opcode == ISCSI_OP_SCSI_DATA_OUT &&
 281                    task->hdr_itt == tmf->rtt) {
 282                        ISCSI_DBG_SESSION(session,
 283                                          "Preventing task %x/%x from sending "
 284                                          "data-out due to abort task in "
 285                                          "progress\n", task->itt,
 286                                          task->hdr_itt);
 287                        return -EACCES;
 288                }
 289                break;
 290        }
 291
 292        return 0;
 293}
 294
 295/**
 296 * iscsi_prep_scsi_cmd_pdu - prep iscsi scsi cmd pdu
 297 * @task: iscsi task
 298 *
 299 * Prep basic iSCSI PDU fields for a scsi cmd pdu. The LLD should set
 300 * fields like dlength or final based on how much data it sends
 301 */
 302static int iscsi_prep_scsi_cmd_pdu(struct iscsi_task *task)
 303{
 304        struct iscsi_conn *conn = task->conn;
 305        struct iscsi_session *session = conn->session;
 306        struct scsi_cmnd *sc = task->sc;
 307        struct iscsi_scsi_req *hdr;
 308        unsigned hdrlength, cmd_len, transfer_length;
 309        itt_t itt;
 310        int rc;
 311
 312        rc = iscsi_check_tmf_restrictions(task, ISCSI_OP_SCSI_CMD);
 313        if (rc)
 314                return rc;
 315
 316        if (conn->session->tt->alloc_pdu) {
 317                rc = conn->session->tt->alloc_pdu(task, ISCSI_OP_SCSI_CMD);
 318                if (rc)
 319                        return rc;
 320        }
 321        hdr = (struct iscsi_scsi_req *)task->hdr;
 322        itt = hdr->itt;
 323        memset(hdr, 0, sizeof(*hdr));
 324
 325        if (session->tt->parse_pdu_itt)
 326                hdr->itt = task->hdr_itt = itt;
 327        else
 328                hdr->itt = task->hdr_itt = build_itt(task->itt,
 329                                                     task->conn->session->age);
 330        task->hdr_len = 0;
 331        rc = iscsi_add_hdr(task, sizeof(*hdr));
 332        if (rc)
 333                return rc;
 334        hdr->opcode = ISCSI_OP_SCSI_CMD;
 335        hdr->flags = ISCSI_ATTR_SIMPLE;
 336        int_to_scsilun(sc->device->lun, &hdr->lun);
 337        task->lun = hdr->lun;
 338        hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
 339        cmd_len = sc->cmd_len;
 340        if (cmd_len < ISCSI_CDB_SIZE)
 341                memset(&hdr->cdb[cmd_len], 0, ISCSI_CDB_SIZE - cmd_len);
 342        else if (cmd_len > ISCSI_CDB_SIZE) {
 343                rc = iscsi_prep_ecdb_ahs(task);
 344                if (rc)
 345                        return rc;
 346                cmd_len = ISCSI_CDB_SIZE;
 347        }
 348        memcpy(hdr->cdb, sc->cmnd, cmd_len);
 349
 350        task->imm_count = 0;
 351        if (scsi_get_prot_op(sc) != SCSI_PROT_NORMAL)
 352                task->protected = true;
 353
 354        transfer_length = scsi_transfer_length(sc);
 355        hdr->data_length = cpu_to_be32(transfer_length);
 356        if (sc->sc_data_direction == DMA_TO_DEVICE) {
 357                struct iscsi_r2t_info *r2t = &task->unsol_r2t;
 358
 359                hdr->flags |= ISCSI_FLAG_CMD_WRITE;
 360                /*
 361                 * Write counters:
 362                 *
 363                 *      imm_count       bytes to be sent right after
 364                 *                      SCSI PDU Header
 365                 *
 366                 *      unsol_count     bytes(as Data-Out) to be sent
 367                 *                      without R2T ack right after
 368                 *                      immediate data
 369                 *
 370                 *      r2t data_length bytes to be sent via R2T ack's
 371                 *
 372                 *      pad_count       bytes to be sent as zero-padding
 373                 */
 374                memset(r2t, 0, sizeof(*r2t));
 375
 376                if (session->imm_data_en) {
 377                        if (transfer_length >= session->first_burst)
 378                                task->imm_count = min(session->first_burst,
 379                                                        conn->max_xmit_dlength);
 380                        else
 381                                task->imm_count = min(transfer_length,
 382                                                      conn->max_xmit_dlength);
 383                        hton24(hdr->dlength, task->imm_count);
 384                } else
 385                        zero_data(hdr->dlength);
 386
 387                if (!session->initial_r2t_en) {
 388                        r2t->data_length = min(session->first_burst,
 389                                               transfer_length) -
 390                                               task->imm_count;
 391                        r2t->data_offset = task->imm_count;
 392                        r2t->ttt = cpu_to_be32(ISCSI_RESERVED_TAG);
 393                        r2t->exp_statsn = cpu_to_be32(conn->exp_statsn);
 394                }
 395
 396                if (!task->unsol_r2t.data_length)
 397                        /* No unsolicit Data-Out's */
 398                        hdr->flags |= ISCSI_FLAG_CMD_FINAL;
 399        } else {
 400                hdr->flags |= ISCSI_FLAG_CMD_FINAL;
 401                zero_data(hdr->dlength);
 402
 403                if (sc->sc_data_direction == DMA_FROM_DEVICE)
 404                        hdr->flags |= ISCSI_FLAG_CMD_READ;
 405        }
 406
 407        /* calculate size of additional header segments (AHSs) */
 408        hdrlength = task->hdr_len - sizeof(*hdr);
 409
 410        WARN_ON(hdrlength & (ISCSI_PAD_LEN-1));
 411        hdrlength /= ISCSI_PAD_LEN;
 412
 413        WARN_ON(hdrlength >= 256);
 414        hdr->hlength = hdrlength & 0xFF;
 415        hdr->cmdsn = task->cmdsn = cpu_to_be32(session->cmdsn);
 416
 417        if (session->tt->init_task && session->tt->init_task(task))
 418                return -EIO;
 419
 420        task->state = ISCSI_TASK_RUNNING;
 421        session->cmdsn++;
 422
 423        conn->scsicmd_pdus_cnt++;
 424        ISCSI_DBG_SESSION(session, "iscsi prep [%s cid %d sc %p cdb 0x%x "
 425                          "itt 0x%x len %d cmdsn %d win %d]\n",
 426                          sc->sc_data_direction == DMA_TO_DEVICE ?
 427                          "write" : "read", conn->id, sc, sc->cmnd[0],
 428                          task->itt, transfer_length,
 429                          session->cmdsn,
 430                          session->max_cmdsn - session->exp_cmdsn + 1);
 431        return 0;
 432}
 433
 434/**
 435 * iscsi_free_task - free a task
 436 * @task: iscsi cmd task
 437 *
 438 * Must be called with session back_lock.
 439 * This function returns the scsi command to scsi-ml or cleans
 440 * up mgmt tasks then returns the task to the pool.
 441 */
 442static void iscsi_free_task(struct iscsi_task *task)
 443{
 444        struct iscsi_conn *conn = task->conn;
 445        struct iscsi_session *session = conn->session;
 446        struct scsi_cmnd *sc = task->sc;
 447        int oldstate = task->state;
 448
 449        ISCSI_DBG_SESSION(session, "freeing task itt 0x%x state %d sc %p\n",
 450                          task->itt, task->state, task->sc);
 451
 452        session->tt->cleanup_task(task);
 453        task->state = ISCSI_TASK_FREE;
 454        task->sc = NULL;
 455        /*
 456         * login task is preallocated so do not free
 457         */
 458        if (conn->login_task == task)
 459                return;
 460
 461        kfifo_in(&session->cmdpool.queue, (void*)&task, sizeof(void*));
 462
 463        if (sc) {
 464                /* SCSI eh reuses commands to verify us */
 465                sc->SCp.ptr = NULL;
 466                /*
 467                 * queue command may call this to free the task, so
 468                 * it will decide how to return sc to scsi-ml.
 469                 */
 470                if (oldstate != ISCSI_TASK_REQUEUE_SCSIQ)
 471                        sc->scsi_done(sc);
 472        }
 473}
 474
 475void __iscsi_get_task(struct iscsi_task *task)
 476{
 477        refcount_inc(&task->refcount);
 478}
 479EXPORT_SYMBOL_GPL(__iscsi_get_task);
 480
 481void __iscsi_put_task(struct iscsi_task *task)
 482{
 483        if (refcount_dec_and_test(&task->refcount))
 484                iscsi_free_task(task);
 485}
 486EXPORT_SYMBOL_GPL(__iscsi_put_task);
 487
 488void iscsi_put_task(struct iscsi_task *task)
 489{
 490        struct iscsi_session *session = task->conn->session;
 491
 492        /* regular RX path uses back_lock */
 493        spin_lock_bh(&session->back_lock);
 494        __iscsi_put_task(task);
 495        spin_unlock_bh(&session->back_lock);
 496}
 497EXPORT_SYMBOL_GPL(iscsi_put_task);
 498
 499/**
 500 * iscsi_complete_task - finish a task
 501 * @task: iscsi cmd task
 502 * @state: state to complete task with
 503 *
 504 * Must be called with session back_lock.
 505 */
 506static void iscsi_complete_task(struct iscsi_task *task, int state)
 507{
 508        struct iscsi_conn *conn = task->conn;
 509
 510        ISCSI_DBG_SESSION(conn->session,
 511                          "complete task itt 0x%x state %d sc %p\n",
 512                          task->itt, task->state, task->sc);
 513        if (task->state == ISCSI_TASK_COMPLETED ||
 514            task->state == ISCSI_TASK_ABRT_TMF ||
 515            task->state == ISCSI_TASK_ABRT_SESS_RECOV ||
 516            task->state == ISCSI_TASK_REQUEUE_SCSIQ)
 517                return;
 518        WARN_ON_ONCE(task->state == ISCSI_TASK_FREE);
 519        task->state = state;
 520
 521        if (READ_ONCE(conn->ping_task) == task)
 522                WRITE_ONCE(conn->ping_task, NULL);
 523
 524        /* release get from queueing */
 525        __iscsi_put_task(task);
 526}
 527
 528/**
 529 * iscsi_complete_scsi_task - finish scsi task normally
 530 * @task: iscsi task for scsi cmd
 531 * @exp_cmdsn: expected cmd sn in cpu format
 532 * @max_cmdsn: max cmd sn in cpu format
 533 *
 534 * This is used when drivers do not need or cannot perform
 535 * lower level pdu processing.
 536 *
 537 * Called with session back_lock
 538 */
 539void iscsi_complete_scsi_task(struct iscsi_task *task,
 540                              uint32_t exp_cmdsn, uint32_t max_cmdsn)
 541{
 542        struct iscsi_conn *conn = task->conn;
 543
 544        ISCSI_DBG_SESSION(conn->session, "[itt 0x%x]\n", task->itt);
 545
 546        conn->last_recv = jiffies;
 547        __iscsi_update_cmdsn(conn->session, exp_cmdsn, max_cmdsn);
 548        iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 549}
 550EXPORT_SYMBOL_GPL(iscsi_complete_scsi_task);
 551
 552/*
 553 * Must be called with back and frwd lock
 554 */
 555static bool cleanup_queued_task(struct iscsi_task *task)
 556{
 557        struct iscsi_conn *conn = task->conn;
 558        bool early_complete = false;
 559
 560        /* Bad target might have completed task while it was still running */
 561        if (task->state == ISCSI_TASK_COMPLETED)
 562                early_complete = true;
 563
 564        if (!list_empty(&task->running)) {
 565                list_del_init(&task->running);
 566                /*
 567                 * If it's on a list but still running, this could be from
 568                 * a bad target sending a rsp early, cleanup from a TMF, or
 569                 * session recovery.
 570                 */
 571                if (task->state == ISCSI_TASK_RUNNING ||
 572                    task->state == ISCSI_TASK_COMPLETED)
 573                        __iscsi_put_task(task);
 574        }
 575
 576        if (conn->session->running_aborted_task == task) {
 577                conn->session->running_aborted_task = NULL;
 578                __iscsi_put_task(task);
 579        }
 580
 581        if (conn->task == task) {
 582                conn->task = NULL;
 583                __iscsi_put_task(task);
 584        }
 585
 586        return early_complete;
 587}
 588
 589/*
 590 * session frwd lock must be held and if not called for a task that is still
 591 * pending or from the xmit thread, then xmit thread must be suspended
 592 */
 593static void fail_scsi_task(struct iscsi_task *task, int err)
 594{
 595        struct iscsi_conn *conn = task->conn;
 596        struct scsi_cmnd *sc;
 597        int state;
 598
 599        spin_lock_bh(&conn->session->back_lock);
 600        if (cleanup_queued_task(task)) {
 601                spin_unlock_bh(&conn->session->back_lock);
 602                return;
 603        }
 604
 605        if (task->state == ISCSI_TASK_PENDING) {
 606                /*
 607                 * cmd never made it to the xmit thread, so we should not count
 608                 * the cmd in the sequencing
 609                 */
 610                conn->session->queued_cmdsn--;
 611                /* it was never sent so just complete like normal */
 612                state = ISCSI_TASK_COMPLETED;
 613        } else if (err == DID_TRANSPORT_DISRUPTED)
 614                state = ISCSI_TASK_ABRT_SESS_RECOV;
 615        else
 616                state = ISCSI_TASK_ABRT_TMF;
 617
 618        sc = task->sc;
 619        sc->result = err << 16;
 620        scsi_set_resid(sc, scsi_bufflen(sc));
 621        iscsi_complete_task(task, state);
 622        spin_unlock_bh(&conn->session->back_lock);
 623}
 624
 625static int iscsi_prep_mgmt_task(struct iscsi_conn *conn,
 626                                struct iscsi_task *task)
 627{
 628        struct iscsi_session *session = conn->session;
 629        struct iscsi_hdr *hdr = task->hdr;
 630        struct iscsi_nopout *nop = (struct iscsi_nopout *)hdr;
 631        uint8_t opcode = hdr->opcode & ISCSI_OPCODE_MASK;
 632
 633        if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
 634                return -ENOTCONN;
 635
 636        if (opcode != ISCSI_OP_LOGIN && opcode != ISCSI_OP_TEXT)
 637                nop->exp_statsn = cpu_to_be32(conn->exp_statsn);
 638        /*
 639         * pre-format CmdSN for outgoing PDU.
 640         */
 641        nop->cmdsn = cpu_to_be32(session->cmdsn);
 642        if (hdr->itt != RESERVED_ITT) {
 643                /*
 644                 * TODO: We always use immediate for normal session pdus.
 645                 * If we start to send tmfs or nops as non-immediate then
 646                 * we should start checking the cmdsn numbers for mgmt tasks.
 647                 *
 648                 * During discovery sessions iscsid sends TEXT as non immediate,
 649                 * but we always only send one PDU at a time.
 650                 */
 651                if (conn->c_stage == ISCSI_CONN_STARTED &&
 652                    !(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
 653                        session->queued_cmdsn++;
 654                        session->cmdsn++;
 655                }
 656        }
 657
 658        if (session->tt->init_task && session->tt->init_task(task))
 659                return -EIO;
 660
 661        if ((hdr->opcode & ISCSI_OPCODE_MASK) == ISCSI_OP_LOGOUT)
 662                session->state = ISCSI_STATE_LOGGING_OUT;
 663
 664        task->state = ISCSI_TASK_RUNNING;
 665        ISCSI_DBG_SESSION(session, "mgmtpdu [op 0x%x hdr->itt 0x%x "
 666                          "datalen %d]\n", hdr->opcode & ISCSI_OPCODE_MASK,
 667                          hdr->itt, task->data_count);
 668        return 0;
 669}
 670
 671static struct iscsi_task *
 672__iscsi_conn_send_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 673                      char *data, uint32_t data_size)
 674{
 675        struct iscsi_session *session = conn->session;
 676        struct iscsi_host *ihost = shost_priv(session->host);
 677        uint8_t opcode = hdr->opcode & ISCSI_OPCODE_MASK;
 678        struct iscsi_task *task;
 679        itt_t itt;
 680
 681        if (session->state == ISCSI_STATE_TERMINATE)
 682                return NULL;
 683
 684        if (opcode == ISCSI_OP_LOGIN || opcode == ISCSI_OP_TEXT) {
 685                /*
 686                 * Login and Text are sent serially, in
 687                 * request-followed-by-response sequence.
 688                 * Same task can be used. Same ITT must be used.
 689                 * Note that login_task is preallocated at conn_create().
 690                 */
 691                if (conn->login_task->state != ISCSI_TASK_FREE) {
 692                        iscsi_conn_printk(KERN_ERR, conn, "Login/Text in "
 693                                          "progress. Cannot start new task.\n");
 694                        return NULL;
 695                }
 696
 697                if (data_size > ISCSI_DEF_MAX_RECV_SEG_LEN) {
 698                        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);
 699                        return NULL;
 700                }
 701
 702                task = conn->login_task;
 703        } else {
 704                if (session->state != ISCSI_STATE_LOGGED_IN)
 705                        return NULL;
 706
 707                if (data_size != 0) {
 708                        iscsi_conn_printk(KERN_ERR, conn, "Can not send data buffer of len %u for op 0x%x\n", data_size, opcode);
 709                        return NULL;
 710                }
 711
 712                BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
 713                BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);
 714
 715                if (!kfifo_out(&session->cmdpool.queue,
 716                                 (void*)&task, sizeof(void*)))
 717                        return NULL;
 718        }
 719        /*
 720         * released in complete pdu for task we expect a response for, and
 721         * released by the lld when it has transmitted the task for
 722         * pdus we do not expect a response for.
 723         */
 724        refcount_set(&task->refcount, 1);
 725        task->conn = conn;
 726        task->sc = NULL;
 727        INIT_LIST_HEAD(&task->running);
 728        task->state = ISCSI_TASK_PENDING;
 729
 730        if (data_size) {
 731                memcpy(task->data, data, data_size);
 732                task->data_count = data_size;
 733        } else
 734                task->data_count = 0;
 735
 736        if (conn->session->tt->alloc_pdu) {
 737                if (conn->session->tt->alloc_pdu(task, hdr->opcode)) {
 738                        iscsi_conn_printk(KERN_ERR, conn, "Could not allocate "
 739                                         "pdu for mgmt task.\n");
 740                        goto free_task;
 741                }
 742        }
 743
 744        itt = task->hdr->itt;
 745        task->hdr_len = sizeof(struct iscsi_hdr);
 746        memcpy(task->hdr, hdr, sizeof(struct iscsi_hdr));
 747
 748        if (hdr->itt != RESERVED_ITT) {
 749                if (session->tt->parse_pdu_itt)
 750                        task->hdr->itt = itt;
 751                else
 752                        task->hdr->itt = build_itt(task->itt,
 753                                                   task->conn->session->age);
 754        }
 755
 756        if (unlikely(READ_ONCE(conn->ping_task) == INVALID_SCSI_TASK))
 757                WRITE_ONCE(conn->ping_task, task);
 758
 759        if (!ihost->workq) {
 760                if (iscsi_prep_mgmt_task(conn, task))
 761                        goto free_task;
 762
 763                if (session->tt->xmit_task(task))
 764                        goto free_task;
 765        } else {
 766                list_add_tail(&task->running, &conn->mgmtqueue);
 767                iscsi_conn_queue_work(conn);
 768        }
 769
 770        return task;
 771
 772free_task:
 773        /* regular RX path uses back_lock */
 774        spin_lock(&session->back_lock);
 775        __iscsi_put_task(task);
 776        spin_unlock(&session->back_lock);
 777        return NULL;
 778}
 779
 780int iscsi_conn_send_pdu(struct iscsi_cls_conn *cls_conn, struct iscsi_hdr *hdr,
 781                        char *data, uint32_t data_size)
 782{
 783        struct iscsi_conn *conn = cls_conn->dd_data;
 784        struct iscsi_session *session = conn->session;
 785        int err = 0;
 786
 787        spin_lock_bh(&session->frwd_lock);
 788        if (!__iscsi_conn_send_pdu(conn, hdr, data, data_size))
 789                err = -EPERM;
 790        spin_unlock_bh(&session->frwd_lock);
 791        return err;
 792}
 793EXPORT_SYMBOL_GPL(iscsi_conn_send_pdu);
 794
 795/**
 796 * iscsi_scsi_cmd_rsp - SCSI Command Response processing
 797 * @conn: iscsi connection
 798 * @hdr: iscsi header
 799 * @task: scsi command task
 800 * @data: cmd data buffer
 801 * @datalen: len of buffer
 802 *
 803 * iscsi_cmd_rsp sets up the scsi_cmnd fields based on the PDU and
 804 * then completes the command and task. called under back_lock
 805 **/
 806static void iscsi_scsi_cmd_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 807                               struct iscsi_task *task, char *data,
 808                               int datalen)
 809{
 810        struct iscsi_scsi_rsp *rhdr = (struct iscsi_scsi_rsp *)hdr;
 811        struct iscsi_session *session = conn->session;
 812        struct scsi_cmnd *sc = task->sc;
 813
 814        iscsi_update_cmdsn(session, (struct iscsi_nopin*)rhdr);
 815        conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 816
 817        sc->result = (DID_OK << 16) | rhdr->cmd_status;
 818
 819        if (task->protected) {
 820                sector_t sector;
 821                u8 ascq;
 822
 823                /**
 824                 * Transports that didn't implement check_protection
 825                 * callback but still published T10-PI support to scsi-mid
 826                 * deserve this BUG_ON.
 827                 **/
 828                BUG_ON(!session->tt->check_protection);
 829
 830                ascq = session->tt->check_protection(task, &sector);
 831                if (ascq) {
 832                        scsi_build_sense(sc, 1, ILLEGAL_REQUEST, 0x10, ascq);
 833                        scsi_set_sense_information(sc->sense_buffer,
 834                                                   SCSI_SENSE_BUFFERSIZE,
 835                                                   sector);
 836                        goto out;
 837                }
 838        }
 839
 840        if (rhdr->response != ISCSI_STATUS_CMD_COMPLETED) {
 841                sc->result = DID_ERROR << 16;
 842                goto out;
 843        }
 844
 845        if (rhdr->cmd_status == SAM_STAT_CHECK_CONDITION) {
 846                uint16_t senselen;
 847
 848                if (datalen < 2) {
 849invalid_datalen:
 850                        iscsi_conn_printk(KERN_ERR,  conn,
 851                                         "Got CHECK_CONDITION but invalid data "
 852                                         "buffer size of %d\n", datalen);
 853                        sc->result = DID_BAD_TARGET << 16;
 854                        goto out;
 855                }
 856
 857                senselen = get_unaligned_be16(data);
 858                if (datalen < senselen)
 859                        goto invalid_datalen;
 860
 861                memcpy(sc->sense_buffer, data + 2,
 862                       min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
 863                ISCSI_DBG_SESSION(session, "copied %d bytes of sense\n",
 864                                  min_t(uint16_t, senselen,
 865                                  SCSI_SENSE_BUFFERSIZE));
 866        }
 867
 868        if (rhdr->flags & (ISCSI_FLAG_CMD_BIDI_UNDERFLOW |
 869                           ISCSI_FLAG_CMD_BIDI_OVERFLOW)) {
 870                sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 871        }
 872
 873        if (rhdr->flags & (ISCSI_FLAG_CMD_UNDERFLOW |
 874                           ISCSI_FLAG_CMD_OVERFLOW)) {
 875                int res_count = be32_to_cpu(rhdr->residual_count);
 876
 877                if (res_count > 0 &&
 878                    (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
 879                     res_count <= scsi_bufflen(sc)))
 880                        /* write side for bidi or uni-io set_resid */
 881                        scsi_set_resid(sc, res_count);
 882                else
 883                        sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 884        }
 885out:
 886        ISCSI_DBG_SESSION(session, "cmd rsp done [sc %p res %d itt 0x%x]\n",
 887                          sc, sc->result, task->itt);
 888        conn->scsirsp_pdus_cnt++;
 889        iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 890}
 891
 892/**
 893 * iscsi_data_in_rsp - SCSI Data-In Response processing
 894 * @conn: iscsi connection
 895 * @hdr:  iscsi pdu
 896 * @task: scsi command task
 897 *
 898 * iscsi_data_in_rsp sets up the scsi_cmnd fields based on the data received
 899 * then completes the command and task. called under back_lock
 900 **/
 901static void
 902iscsi_data_in_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 903                  struct iscsi_task *task)
 904{
 905        struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)hdr;
 906        struct scsi_cmnd *sc = task->sc;
 907
 908        if (!(rhdr->flags & ISCSI_FLAG_DATA_STATUS))
 909                return;
 910
 911        iscsi_update_cmdsn(conn->session, (struct iscsi_nopin *)hdr);
 912        sc->result = (DID_OK << 16) | rhdr->cmd_status;
 913        conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 914        if (rhdr->flags & (ISCSI_FLAG_DATA_UNDERFLOW |
 915                           ISCSI_FLAG_DATA_OVERFLOW)) {
 916                int res_count = be32_to_cpu(rhdr->residual_count);
 917
 918                if (res_count > 0 &&
 919                    (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
 920                     res_count <= sc->sdb.length))
 921                        scsi_set_resid(sc, res_count);
 922                else
 923                        sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 924        }
 925
 926        ISCSI_DBG_SESSION(conn->session, "data in with status done "
 927                          "[sc %p res %d itt 0x%x]\n",
 928                          sc, sc->result, task->itt);
 929        conn->scsirsp_pdus_cnt++;
 930        iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 931}
 932
 933static void iscsi_tmf_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
 934{
 935        struct iscsi_tm_rsp *tmf = (struct iscsi_tm_rsp *)hdr;
 936        struct iscsi_session *session = conn->session;
 937
 938        conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 939        conn->tmfrsp_pdus_cnt++;
 940
 941        if (session->tmf_state != TMF_QUEUED)
 942                return;
 943
 944        if (tmf->response == ISCSI_TMF_RSP_COMPLETE)
 945                session->tmf_state = TMF_SUCCESS;
 946        else if (tmf->response == ISCSI_TMF_RSP_NO_TASK)
 947                session->tmf_state = TMF_NOT_FOUND;
 948        else
 949                session->tmf_state = TMF_FAILED;
 950        wake_up(&session->ehwait);
 951}
 952
 953static int iscsi_send_nopout(struct iscsi_conn *conn, struct iscsi_nopin *rhdr)
 954{
 955        struct iscsi_nopout hdr;
 956        struct iscsi_task *task;
 957
 958        if (!rhdr) {
 959                if (READ_ONCE(conn->ping_task))
 960                        return -EINVAL;
 961                WRITE_ONCE(conn->ping_task, INVALID_SCSI_TASK);
 962        }
 963
 964        memset(&hdr, 0, sizeof(struct iscsi_nopout));
 965        hdr.opcode = ISCSI_OP_NOOP_OUT | ISCSI_OP_IMMEDIATE;
 966        hdr.flags = ISCSI_FLAG_CMD_FINAL;
 967
 968        if (rhdr) {
 969                hdr.lun = rhdr->lun;
 970                hdr.ttt = rhdr->ttt;
 971                hdr.itt = RESERVED_ITT;
 972        } else
 973                hdr.ttt = RESERVED_ITT;
 974
 975        task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)&hdr, NULL, 0);
 976        if (!task) {
 977                if (!rhdr)
 978                        WRITE_ONCE(conn->ping_task, NULL);
 979                iscsi_conn_printk(KERN_ERR, conn, "Could not send nopout\n");
 980                return -EIO;
 981        } else if (!rhdr) {
 982                /* only track our nops */
 983                conn->last_ping = jiffies;
 984        }
 985
 986        return 0;
 987}
 988
 989/**
 990 * iscsi_nop_out_rsp - SCSI NOP Response processing
 991 * @task: scsi command task
 992 * @nop: the nop structure
 993 * @data: where to put the data
 994 * @datalen: length of data
 995 *
 996 * iscsi_nop_out_rsp handles nop response from use or
 997 * from user space. called under back_lock
 998 **/
 999static int iscsi_nop_out_rsp(struct iscsi_task *task,
1000                             struct iscsi_nopin *nop, char *data, int datalen)
1001{
1002        struct iscsi_conn *conn = task->conn;
1003        int rc = 0;
1004
1005        if (READ_ONCE(conn->ping_task) != task) {
1006                /*
1007                 * If this is not in response to one of our
1008                 * nops then it must be from userspace.
1009                 */
1010                if (iscsi_recv_pdu(conn->cls_conn, (struct iscsi_hdr *)nop,
1011                                   data, datalen))
1012                        rc = ISCSI_ERR_CONN_FAILED;
1013        } else
1014                mod_timer(&conn->transport_timer, jiffies + conn->recv_timeout);
1015        iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1016        return rc;
1017}
1018
1019static int iscsi_handle_reject(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1020                               char *data, int datalen)
1021{
1022        struct iscsi_reject *reject = (struct iscsi_reject *)hdr;
1023        struct iscsi_hdr rejected_pdu;
1024        int opcode, rc = 0;
1025
1026        conn->exp_statsn = be32_to_cpu(reject->statsn) + 1;
1027
1028        if (ntoh24(reject->dlength) > datalen ||
1029            ntoh24(reject->dlength) < sizeof(struct iscsi_hdr)) {
1030                iscsi_conn_printk(KERN_ERR, conn, "Cannot handle rejected "
1031                                  "pdu. Invalid data length (pdu dlength "
1032                                  "%u, datalen %d\n", ntoh24(reject->dlength),
1033                                  datalen);
1034                return ISCSI_ERR_PROTO;
1035        }
1036        memcpy(&rejected_pdu, data, sizeof(struct iscsi_hdr));
1037        opcode = rejected_pdu.opcode & ISCSI_OPCODE_MASK;
1038
1039        switch (reject->reason) {
1040        case ISCSI_REASON_DATA_DIGEST_ERROR:
1041                iscsi_conn_printk(KERN_ERR, conn,
1042                                  "pdu (op 0x%x itt 0x%x) rejected "
1043                                  "due to DataDigest error.\n",
1044                                  opcode, rejected_pdu.itt);
1045                break;
1046        case ISCSI_REASON_IMM_CMD_REJECT:
1047                iscsi_conn_printk(KERN_ERR, conn,
1048                                  "pdu (op 0x%x itt 0x%x) rejected. Too many "
1049                                  "immediate commands.\n",
1050                                  opcode, rejected_pdu.itt);
1051                /*
1052                 * We only send one TMF at a time so if the target could not
1053                 * handle it, then it should get fixed (RFC mandates that
1054                 * a target can handle one immediate TMF per conn).
1055                 *
1056                 * For nops-outs, we could have sent more than one if
1057                 * the target is sending us lots of nop-ins
1058                 */
1059                if (opcode != ISCSI_OP_NOOP_OUT)
1060                        return 0;
1061
1062                if (rejected_pdu.itt == cpu_to_be32(ISCSI_RESERVED_TAG)) {
1063                        /*
1064                         * nop-out in response to target's nop-out rejected.
1065                         * Just resend.
1066                         */
1067                        /* In RX path we are under back lock */
1068                        spin_unlock(&conn->session->back_lock);
1069                        spin_lock(&conn->session->frwd_lock);
1070                        iscsi_send_nopout(conn,
1071                                          (struct iscsi_nopin*)&rejected_pdu);
1072                        spin_unlock(&conn->session->frwd_lock);
1073                        spin_lock(&conn->session->back_lock);
1074                } else {
1075                        struct iscsi_task *task;
1076                        /*
1077                         * Our nop as ping got dropped. We know the target
1078                         * and transport are ok so just clean up
1079                         */
1080                        task = iscsi_itt_to_task(conn, rejected_pdu.itt);
1081                        if (!task) {
1082                                iscsi_conn_printk(KERN_ERR, conn,
1083                                                 "Invalid pdu reject. Could "
1084                                                 "not lookup rejected task.\n");
1085                                rc = ISCSI_ERR_BAD_ITT;
1086                        } else
1087                                rc = iscsi_nop_out_rsp(task,
1088                                        (struct iscsi_nopin*)&rejected_pdu,
1089                                        NULL, 0);
1090                }
1091                break;
1092        default:
1093                iscsi_conn_printk(KERN_ERR, conn,
1094                                  "pdu (op 0x%x itt 0x%x) rejected. Reason "
1095                                  "code 0x%x\n", rejected_pdu.opcode,
1096                                  rejected_pdu.itt, reject->reason);
1097                break;
1098        }
1099        return rc;
1100}
1101
1102/**
1103 * iscsi_itt_to_task - look up task by itt
1104 * @conn: iscsi connection
1105 * @itt: itt
1106 *
1107 * This should be used for mgmt tasks like login and nops, or if
1108 * the LDD's itt space does not include the session age.
1109 *
1110 * The session back_lock must be held.
1111 */
1112struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *conn, itt_t itt)
1113{
1114        struct iscsi_session *session = conn->session;
1115        int i;
1116
1117        if (itt == RESERVED_ITT)
1118                return NULL;
1119
1120        if (session->tt->parse_pdu_itt)
1121                session->tt->parse_pdu_itt(conn, itt, &i, NULL);
1122        else
1123                i = get_itt(itt);
1124        if (i >= session->cmds_max)
1125                return NULL;
1126
1127        return session->cmds[i];
1128}
1129EXPORT_SYMBOL_GPL(iscsi_itt_to_task);
1130
1131/**
1132 * __iscsi_complete_pdu - complete pdu
1133 * @conn: iscsi conn
1134 * @hdr: iscsi header
1135 * @data: data buffer
1136 * @datalen: len of data buffer
1137 *
1138 * Completes pdu processing by freeing any resources allocated at
1139 * queuecommand or send generic. session back_lock must be held and verify
1140 * itt must have been called.
1141 */
1142int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1143                         char *data, int datalen)
1144{
1145        struct iscsi_session *session = conn->session;
1146        int opcode = hdr->opcode & ISCSI_OPCODE_MASK, rc = 0;
1147        struct iscsi_task *task;
1148        uint32_t itt;
1149
1150        conn->last_recv = jiffies;
1151        rc = iscsi_verify_itt(conn, hdr->itt);
1152        if (rc)
1153                return rc;
1154
1155        if (hdr->itt != RESERVED_ITT)
1156                itt = get_itt(hdr->itt);
1157        else
1158                itt = ~0U;
1159
1160        ISCSI_DBG_SESSION(session, "[op 0x%x cid %d itt 0x%x len %d]\n",
1161                          opcode, conn->id, itt, datalen);
1162
1163        if (itt == ~0U) {
1164                iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1165
1166                switch(opcode) {
1167                case ISCSI_OP_NOOP_IN:
1168                        if (datalen) {
1169                                rc = ISCSI_ERR_PROTO;
1170                                break;
1171                        }
1172
1173                        if (hdr->ttt == cpu_to_be32(ISCSI_RESERVED_TAG))
1174                                break;
1175
1176                        /* In RX path we are under back lock */
1177                        spin_unlock(&session->back_lock);
1178                        spin_lock(&session->frwd_lock);
1179                        iscsi_send_nopout(conn, (struct iscsi_nopin*)hdr);
1180                        spin_unlock(&session->frwd_lock);
1181                        spin_lock(&session->back_lock);
1182                        break;
1183                case ISCSI_OP_REJECT:
1184                        rc = iscsi_handle_reject(conn, hdr, data, datalen);
1185                        break;
1186                case ISCSI_OP_ASYNC_EVENT:
1187                        conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1188                        if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
1189                                rc = ISCSI_ERR_CONN_FAILED;
1190                        break;
1191                default:
1192                        rc = ISCSI_ERR_BAD_OPCODE;
1193                        break;
1194                }
1195                goto out;
1196        }
1197
1198        switch(opcode) {
1199        case ISCSI_OP_SCSI_CMD_RSP:
1200        case ISCSI_OP_SCSI_DATA_IN:
1201                task = iscsi_itt_to_ctask(conn, hdr->itt);
1202                if (!task)
1203                        return ISCSI_ERR_BAD_ITT;
1204                task->last_xfer = jiffies;
1205                break;
1206        case ISCSI_OP_R2T:
1207                /*
1208                 * LLD handles R2Ts if they need to.
1209                 */
1210                return 0;
1211        case ISCSI_OP_LOGOUT_RSP:
1212        case ISCSI_OP_LOGIN_RSP:
1213        case ISCSI_OP_TEXT_RSP:
1214        case ISCSI_OP_SCSI_TMFUNC_RSP:
1215        case ISCSI_OP_NOOP_IN:
1216                task = iscsi_itt_to_task(conn, hdr->itt);
1217                if (!task)
1218                        return ISCSI_ERR_BAD_ITT;
1219                break;
1220        default:
1221                return ISCSI_ERR_BAD_OPCODE;
1222        }
1223
1224        switch(opcode) {
1225        case ISCSI_OP_SCSI_CMD_RSP:
1226                iscsi_scsi_cmd_rsp(conn, hdr, task, data, datalen);
1227                break;
1228        case ISCSI_OP_SCSI_DATA_IN:
1229                iscsi_data_in_rsp(conn, hdr, task);
1230                break;
1231        case ISCSI_OP_LOGOUT_RSP:
1232                iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1233                if (datalen) {
1234                        rc = ISCSI_ERR_PROTO;
1235                        break;
1236                }
1237                conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1238                goto recv_pdu;
1239        case ISCSI_OP_LOGIN_RSP:
1240        case ISCSI_OP_TEXT_RSP:
1241                iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1242                /*
1243                 * login related PDU's exp_statsn is handled in
1244                 * userspace
1245                 */
1246                goto recv_pdu;
1247        case ISCSI_OP_SCSI_TMFUNC_RSP:
1248                iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1249                if (datalen) {
1250                        rc = ISCSI_ERR_PROTO;
1251                        break;
1252                }
1253
1254                iscsi_tmf_rsp(conn, hdr);
1255                iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1256                break;
1257        case ISCSI_OP_NOOP_IN:
1258                iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1259                if (hdr->ttt != cpu_to_be32(ISCSI_RESERVED_TAG) || datalen) {
1260                        rc = ISCSI_ERR_PROTO;
1261                        break;
1262                }
1263                conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1264
1265                rc = iscsi_nop_out_rsp(task, (struct iscsi_nopin*)hdr,
1266                                       data, datalen);
1267                break;
1268        default:
1269                rc = ISCSI_ERR_BAD_OPCODE;
1270                break;
1271        }
1272
1273out:
1274        return rc;
1275recv_pdu:
1276        if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
1277                rc = ISCSI_ERR_CONN_FAILED;
1278        iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1279        return rc;
1280}
1281EXPORT_SYMBOL_GPL(__iscsi_complete_pdu);
1282
1283int iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1284                       char *data, int datalen)
1285{
1286        int rc;
1287
1288        spin_lock(&conn->session->back_lock);
1289        rc = __iscsi_complete_pdu(conn, hdr, data, datalen);
1290        spin_unlock(&conn->session->back_lock);
1291        return rc;
1292}
1293EXPORT_SYMBOL_GPL(iscsi_complete_pdu);
1294
1295int iscsi_verify_itt(struct iscsi_conn *conn, itt_t itt)
1296{
1297        struct iscsi_session *session = conn->session;
1298        int age = 0, i = 0;
1299
1300        if (itt == RESERVED_ITT)
1301                return 0;
1302
1303        if (session->tt->parse_pdu_itt)
1304                session->tt->parse_pdu_itt(conn, itt, &i, &age);
1305        else {
1306                i = get_itt(itt);
1307                age = ((__force u32)itt >> ISCSI_AGE_SHIFT) & ISCSI_AGE_MASK;
1308        }
1309
1310        if (age != session->age) {
1311                iscsi_conn_printk(KERN_ERR, conn,
1312                                  "received itt %x expected session age (%x)\n",
1313                                  (__force u32)itt, session->age);
1314                return ISCSI_ERR_BAD_ITT;
1315        }
1316
1317        if (i >= session->cmds_max) {
1318                iscsi_conn_printk(KERN_ERR, conn,
1319                                  "received invalid itt index %u (max cmds "
1320                                   "%u.\n", i, session->cmds_max);
1321                return ISCSI_ERR_BAD_ITT;
1322        }
1323        return 0;
1324}
1325EXPORT_SYMBOL_GPL(iscsi_verify_itt);
1326
1327/**
1328 * iscsi_itt_to_ctask - look up ctask by itt
1329 * @conn: iscsi connection
1330 * @itt: itt
1331 *
1332 * This should be used for cmd tasks.
1333 *
1334 * The session back_lock must be held.
1335 */
1336struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *conn, itt_t itt)
1337{
1338        struct iscsi_task *task;
1339
1340        if (iscsi_verify_itt(conn, itt))
1341                return NULL;
1342
1343        task = iscsi_itt_to_task(conn, itt);
1344        if (!task || !task->sc)
1345                return NULL;
1346
1347        if (task->sc->SCp.phase != conn->session->age) {
1348                iscsi_session_printk(KERN_ERR, conn->session,
1349                                  "task's session age %d, expected %d\n",
1350                                  task->sc->SCp.phase, conn->session->age);
1351                return NULL;
1352        }
1353
1354        return task;
1355}
1356EXPORT_SYMBOL_GPL(iscsi_itt_to_ctask);
1357
1358void iscsi_session_failure(struct iscsi_session *session,
1359                           enum iscsi_err err)
1360{
1361        struct iscsi_conn *conn;
1362
1363        spin_lock_bh(&session->frwd_lock);
1364        conn = session->leadconn;
1365        if (session->state == ISCSI_STATE_TERMINATE || !conn) {
1366                spin_unlock_bh(&session->frwd_lock);
1367                return;
1368        }
1369
1370        iscsi_get_conn(conn->cls_conn);
1371        spin_unlock_bh(&session->frwd_lock);
1372        /*
1373         * if the host is being removed bypass the connection
1374         * recovery initialization because we are going to kill
1375         * the session.
1376         */
1377        if (err == ISCSI_ERR_INVALID_HOST)
1378                iscsi_conn_error_event(conn->cls_conn, err);
1379        else
1380                iscsi_conn_failure(conn, err);
1381        iscsi_put_conn(conn->cls_conn);
1382}
1383EXPORT_SYMBOL_GPL(iscsi_session_failure);
1384
1385static bool iscsi_set_conn_failed(struct iscsi_conn *conn)
1386{
1387        struct iscsi_session *session = conn->session;
1388
1389        if (session->state == ISCSI_STATE_FAILED)
1390                return false;
1391
1392        if (conn->stop_stage == 0)
1393                session->state = ISCSI_STATE_FAILED;
1394
1395        set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1396        set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
1397        return true;
1398}
1399
1400void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err)
1401{
1402        struct iscsi_session *session = conn->session;
1403        bool needs_evt;
1404
1405        spin_lock_bh(&session->frwd_lock);
1406        needs_evt = iscsi_set_conn_failed(conn);
1407        spin_unlock_bh(&session->frwd_lock);
1408
1409        if (needs_evt)
1410                iscsi_conn_error_event(conn->cls_conn, err);
1411}
1412EXPORT_SYMBOL_GPL(iscsi_conn_failure);
1413
1414static int iscsi_check_cmdsn_window_closed(struct iscsi_conn *conn)
1415{
1416        struct iscsi_session *session = conn->session;
1417
1418        /*
1419         * Check for iSCSI window and take care of CmdSN wrap-around
1420         */
1421        if (!iscsi_sna_lte(session->queued_cmdsn, session->max_cmdsn)) {
1422                ISCSI_DBG_SESSION(session, "iSCSI CmdSN closed. ExpCmdSn "
1423                                  "%u MaxCmdSN %u CmdSN %u/%u\n",
1424                                  session->exp_cmdsn, session->max_cmdsn,
1425                                  session->cmdsn, session->queued_cmdsn);
1426                return -ENOSPC;
1427        }
1428        return 0;
1429}
1430
1431static int iscsi_xmit_task(struct iscsi_conn *conn, struct iscsi_task *task,
1432                           bool was_requeue)
1433{
1434        int rc;
1435
1436        spin_lock_bh(&conn->session->back_lock);
1437
1438        if (!conn->task) {
1439                /* Take a ref so we can access it after xmit_task() */
1440                __iscsi_get_task(task);
1441        } else {
1442                /* Already have a ref from when we failed to send it last call */
1443                conn->task = NULL;
1444        }
1445
1446        /*
1447         * If this was a requeue for a R2T we have an extra ref on the task in
1448         * case a bad target sends a cmd rsp before we have handled the task.
1449         */
1450        if (was_requeue)
1451                __iscsi_put_task(task);
1452
1453        /*
1454         * Do this after dropping the extra ref because if this was a requeue
1455         * it's removed from that list and cleanup_queued_task would miss it.
1456         */
1457        if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx)) {
1458                /*
1459                 * Save the task and ref in case we weren't cleaning up this
1460                 * task and get woken up again.
1461                 */
1462                conn->task = task;
1463                spin_unlock_bh(&conn->session->back_lock);
1464                return -ENODATA;
1465        }
1466        spin_unlock_bh(&conn->session->back_lock);
1467
1468        spin_unlock_bh(&conn->session->frwd_lock);
1469        rc = conn->session->tt->xmit_task(task);
1470        spin_lock_bh(&conn->session->frwd_lock);
1471        if (!rc) {
1472                /* done with this task */
1473                task->last_xfer = jiffies;
1474        }
1475        /* regular RX path uses back_lock */
1476        spin_lock(&conn->session->back_lock);
1477        if (rc && task->state == ISCSI_TASK_RUNNING) {
1478                /*
1479                 * get an extra ref that is released next time we access it
1480                 * as conn->task above.
1481                 */
1482                __iscsi_get_task(task);
1483                conn->task = task;
1484        }
1485
1486        __iscsi_put_task(task);
1487        spin_unlock(&conn->session->back_lock);
1488        return rc;
1489}
1490
1491/**
1492 * iscsi_requeue_task - requeue task to run from session workqueue
1493 * @task: task to requeue
1494 *
1495 * Callers must have taken a ref to the task that is going to be requeued.
1496 */
1497void iscsi_requeue_task(struct iscsi_task *task)
1498{
1499        struct iscsi_conn *conn = task->conn;
1500
1501        /*
1502         * this may be on the requeue list already if the xmit_task callout
1503         * is handling the r2ts while we are adding new ones
1504         */
1505        spin_lock_bh(&conn->session->frwd_lock);
1506        if (list_empty(&task->running)) {
1507                list_add_tail(&task->running, &conn->requeue);
1508        } else {
1509                /*
1510                 * Don't need the extra ref since it's already requeued and
1511                 * has a ref.
1512                 */
1513                iscsi_put_task(task);
1514        }
1515        iscsi_conn_queue_work(conn);
1516        spin_unlock_bh(&conn->session->frwd_lock);
1517}
1518EXPORT_SYMBOL_GPL(iscsi_requeue_task);
1519
1520/**
1521 * iscsi_data_xmit - xmit any command into the scheduled connection
1522 * @conn: iscsi connection
1523 *
1524 * Notes:
1525 *      The function can return -EAGAIN in which case the caller must
1526 *      re-schedule it again later or recover. '0' return code means
1527 *      successful xmit.
1528 **/
1529static int iscsi_data_xmit(struct iscsi_conn *conn)
1530{
1531        struct iscsi_task *task;
1532        int rc = 0;
1533
1534        spin_lock_bh(&conn->session->frwd_lock);
1535        if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx)) {
1536                ISCSI_DBG_SESSION(conn->session, "Tx suspended!\n");
1537                spin_unlock_bh(&conn->session->frwd_lock);
1538                return -ENODATA;
1539        }
1540
1541        if (conn->task) {
1542                rc = iscsi_xmit_task(conn, conn->task, false);
1543                if (rc)
1544                        goto done;
1545        }
1546
1547        /*
1548         * process mgmt pdus like nops before commands since we should
1549         * only have one nop-out as a ping from us and targets should not
1550         * overflow us with nop-ins
1551         */
1552check_mgmt:
1553        while (!list_empty(&conn->mgmtqueue)) {
1554                task = list_entry(conn->mgmtqueue.next, struct iscsi_task,
1555                                  running);
1556                list_del_init(&task->running);
1557                if (iscsi_prep_mgmt_task(conn, task)) {
1558                        /* regular RX path uses back_lock */
1559                        spin_lock_bh(&conn->session->back_lock);
1560                        __iscsi_put_task(task);
1561                        spin_unlock_bh(&conn->session->back_lock);
1562                        continue;
1563                }
1564                rc = iscsi_xmit_task(conn, task, false);
1565                if (rc)
1566                        goto done;
1567        }
1568
1569        /* process pending command queue */
1570        while (!list_empty(&conn->cmdqueue)) {
1571                task = list_entry(conn->cmdqueue.next, struct iscsi_task,
1572                                  running);
1573                list_del_init(&task->running);
1574                if (conn->session->state == ISCSI_STATE_LOGGING_OUT) {
1575                        fail_scsi_task(task, DID_IMM_RETRY);
1576                        continue;
1577                }
1578                rc = iscsi_prep_scsi_cmd_pdu(task);
1579                if (rc) {
1580                        if (rc == -ENOMEM || rc == -EACCES)
1581                                fail_scsi_task(task, DID_IMM_RETRY);
1582                        else
1583                                fail_scsi_task(task, DID_ABORT);
1584                        continue;
1585                }
1586                rc = iscsi_xmit_task(conn, task, false);
1587                if (rc)
1588                        goto done;
1589                /*
1590                 * we could continuously get new task requests so
1591                 * we need to check the mgmt queue for nops that need to
1592                 * be sent to aviod starvation
1593                 */
1594                if (!list_empty(&conn->mgmtqueue))
1595                        goto check_mgmt;
1596        }
1597
1598        while (!list_empty(&conn->requeue)) {
1599                /*
1600                 * we always do fastlogout - conn stop code will clean up.
1601                 */
1602                if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
1603                        break;
1604
1605                task = list_entry(conn->requeue.next, struct iscsi_task,
1606                                  running);
1607
1608                if (iscsi_check_tmf_restrictions(task, ISCSI_OP_SCSI_DATA_OUT))
1609                        break;
1610
1611                list_del_init(&task->running);
1612                rc = iscsi_xmit_task(conn, task, true);
1613                if (rc)
1614                        goto done;
1615                if (!list_empty(&conn->mgmtqueue))
1616                        goto check_mgmt;
1617        }
1618        spin_unlock_bh(&conn->session->frwd_lock);
1619        return -ENODATA;
1620
1621done:
1622        spin_unlock_bh(&conn->session->frwd_lock);
1623        return rc;
1624}
1625
1626static void iscsi_xmitworker(struct work_struct *work)
1627{
1628        struct iscsi_conn *conn =
1629                container_of(work, struct iscsi_conn, xmitwork);
1630        int rc;
1631        /*
1632         * serialize Xmit worker on a per-connection basis.
1633         */
1634        do {
1635                rc = iscsi_data_xmit(conn);
1636        } while (rc >= 0 || rc == -EAGAIN);
1637}
1638
1639static inline struct iscsi_task *iscsi_alloc_task(struct iscsi_conn *conn,
1640                                                  struct scsi_cmnd *sc)
1641{
1642        struct iscsi_task *task;
1643
1644        if (!kfifo_out(&conn->session->cmdpool.queue,
1645                         (void *) &task, sizeof(void *)))
1646                return NULL;
1647
1648        sc->SCp.phase = conn->session->age;
1649        sc->SCp.ptr = (char *) task;
1650
1651        refcount_set(&task->refcount, 1);
1652        task->state = ISCSI_TASK_PENDING;
1653        task->conn = conn;
1654        task->sc = sc;
1655        task->have_checked_conn = false;
1656        task->last_timeout = jiffies;
1657        task->last_xfer = jiffies;
1658        task->protected = false;
1659        INIT_LIST_HEAD(&task->running);
1660        return task;
1661}
1662
1663enum {
1664        FAILURE_BAD_HOST = 1,
1665        FAILURE_SESSION_FAILED,
1666        FAILURE_SESSION_FREED,
1667        FAILURE_WINDOW_CLOSED,
1668        FAILURE_OOM,
1669        FAILURE_SESSION_TERMINATE,
1670        FAILURE_SESSION_IN_RECOVERY,
1671        FAILURE_SESSION_RECOVERY_TIMEOUT,
1672        FAILURE_SESSION_LOGGING_OUT,
1673        FAILURE_SESSION_NOT_READY,
1674};
1675
1676int iscsi_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *sc)
1677{
1678        struct iscsi_cls_session *cls_session;
1679        struct iscsi_host *ihost;
1680        int reason = 0;
1681        struct iscsi_session *session;
1682        struct iscsi_conn *conn;
1683        struct iscsi_task *task = NULL;
1684
1685        sc->result = 0;
1686        sc->SCp.ptr = NULL;
1687
1688        ihost = shost_priv(host);
1689
1690        cls_session = starget_to_session(scsi_target(sc->device));
1691        session = cls_session->dd_data;
1692        spin_lock_bh(&session->frwd_lock);
1693
1694        reason = iscsi_session_chkready(cls_session);
1695        if (reason) {
1696                sc->result = reason;
1697                goto fault;
1698        }
1699
1700        if (session->state != ISCSI_STATE_LOGGED_IN) {
1701                /*
1702                 * to handle the race between when we set the recovery state
1703                 * and block the session we requeue here (commands could
1704                 * be entering our queuecommand while a block is starting
1705                 * up because the block code is not locked)
1706                 */
1707                switch (session->state) {
1708                case ISCSI_STATE_FAILED:
1709                        /*
1710                         * cmds should fail during shutdown, if the session
1711                         * state is bad, allowing completion to happen
1712                         */
1713                        if (unlikely(system_state != SYSTEM_RUNNING)) {
1714                                reason = FAILURE_SESSION_FAILED;
1715                                sc->result = DID_NO_CONNECT << 16;
1716                                break;
1717                        }
1718                        fallthrough;
1719                case ISCSI_STATE_IN_RECOVERY:
1720                        reason = FAILURE_SESSION_IN_RECOVERY;
1721                        sc->result = DID_IMM_RETRY << 16;
1722                        break;
1723                case ISCSI_STATE_LOGGING_OUT:
1724                        reason = FAILURE_SESSION_LOGGING_OUT;
1725                        sc->result = DID_IMM_RETRY << 16;
1726                        break;
1727                case ISCSI_STATE_RECOVERY_FAILED:
1728                        reason = FAILURE_SESSION_RECOVERY_TIMEOUT;
1729                        sc->result = DID_TRANSPORT_FAILFAST << 16;
1730                        break;
1731                case ISCSI_STATE_TERMINATE:
1732                        reason = FAILURE_SESSION_TERMINATE;
1733                        sc->result = DID_NO_CONNECT << 16;
1734                        break;
1735                default:
1736                        reason = FAILURE_SESSION_FREED;
1737                        sc->result = DID_NO_CONNECT << 16;
1738                }
1739                goto fault;
1740        }
1741
1742        conn = session->leadconn;
1743        if (!conn) {
1744                reason = FAILURE_SESSION_FREED;
1745                sc->result = DID_NO_CONNECT << 16;
1746                goto fault;
1747        }
1748
1749        if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx)) {
1750                reason = FAILURE_SESSION_IN_RECOVERY;
1751                sc->result = DID_REQUEUE << 16;
1752                goto fault;
1753        }
1754
1755        if (iscsi_check_cmdsn_window_closed(conn)) {
1756                reason = FAILURE_WINDOW_CLOSED;
1757                goto reject;
1758        }
1759
1760        task = iscsi_alloc_task(conn, sc);
1761        if (!task) {
1762                reason = FAILURE_OOM;
1763                goto reject;
1764        }
1765
1766        if (!ihost->workq) {
1767                reason = iscsi_prep_scsi_cmd_pdu(task);
1768                if (reason) {
1769                        if (reason == -ENOMEM ||  reason == -EACCES) {
1770                                reason = FAILURE_OOM;
1771                                goto prepd_reject;
1772                        } else {
1773                                sc->result = DID_ABORT << 16;
1774                                goto prepd_fault;
1775                        }
1776                }
1777                if (session->tt->xmit_task(task)) {
1778                        session->cmdsn--;
1779                        reason = FAILURE_SESSION_NOT_READY;
1780                        goto prepd_reject;
1781                }
1782        } else {
1783                list_add_tail(&task->running, &conn->cmdqueue);
1784                iscsi_conn_queue_work(conn);
1785        }
1786
1787        session->queued_cmdsn++;
1788        spin_unlock_bh(&session->frwd_lock);
1789        return 0;
1790
1791prepd_reject:
1792        spin_lock_bh(&session->back_lock);
1793        iscsi_complete_task(task, ISCSI_TASK_REQUEUE_SCSIQ);
1794        spin_unlock_bh(&session->back_lock);
1795reject:
1796        spin_unlock_bh(&session->frwd_lock);
1797        ISCSI_DBG_SESSION(session, "cmd 0x%x rejected (%d)\n",
1798                          sc->cmnd[0], reason);
1799        return SCSI_MLQUEUE_TARGET_BUSY;
1800
1801prepd_fault:
1802        spin_lock_bh(&session->back_lock);
1803        iscsi_complete_task(task, ISCSI_TASK_REQUEUE_SCSIQ);
1804        spin_unlock_bh(&session->back_lock);
1805fault:
1806        spin_unlock_bh(&session->frwd_lock);
1807        ISCSI_DBG_SESSION(session, "iscsi: cmd 0x%x is not queued (%d)\n",
1808                          sc->cmnd[0], reason);
1809        scsi_set_resid(sc, scsi_bufflen(sc));
1810        sc->scsi_done(sc);
1811        return 0;
1812}
1813EXPORT_SYMBOL_GPL(iscsi_queuecommand);
1814
1815int iscsi_target_alloc(struct scsi_target *starget)
1816{
1817        struct iscsi_cls_session *cls_session = starget_to_session(starget);
1818        struct iscsi_session *session = cls_session->dd_data;
1819
1820        starget->can_queue = session->scsi_cmds_max;
1821        return 0;
1822}
1823EXPORT_SYMBOL_GPL(iscsi_target_alloc);
1824
1825static void iscsi_tmf_timedout(struct timer_list *t)
1826{
1827        struct iscsi_session *session = from_timer(session, t, tmf_timer);
1828
1829        spin_lock(&session->frwd_lock);
1830        if (session->tmf_state == TMF_QUEUED) {
1831                session->tmf_state = TMF_TIMEDOUT;
1832                ISCSI_DBG_EH(session, "tmf timedout\n");
1833                /* unblock eh_abort() */
1834                wake_up(&session->ehwait);
1835        }
1836        spin_unlock(&session->frwd_lock);
1837}
1838
1839static int iscsi_exec_task_mgmt_fn(struct iscsi_conn *conn,
1840                                   struct iscsi_tm *hdr, int age,
1841                                   int timeout)
1842        __must_hold(&session->frwd_lock)
1843{
1844        struct iscsi_session *session = conn->session;
1845        struct iscsi_task *task;
1846
1847        task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)hdr,
1848                                      NULL, 0);
1849        if (!task) {
1850                spin_unlock_bh(&session->frwd_lock);
1851                iscsi_conn_printk(KERN_ERR, conn, "Could not send TMF.\n");
1852                iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1853                spin_lock_bh(&session->frwd_lock);
1854                return -EPERM;
1855        }
1856        conn->tmfcmd_pdus_cnt++;
1857        session->tmf_timer.expires = timeout * HZ + jiffies;
1858        add_timer(&session->tmf_timer);
1859        ISCSI_DBG_EH(session, "tmf set timeout\n");
1860
1861        spin_unlock_bh(&session->frwd_lock);
1862        mutex_unlock(&session->eh_mutex);
1863
1864        /*
1865         * block eh thread until:
1866         *
1867         * 1) tmf response
1868         * 2) tmf timeout
1869         * 3) session is terminated or restarted or userspace has
1870         * given up on recovery
1871         */
1872        wait_event_interruptible(session->ehwait, age != session->age ||
1873                                 session->state != ISCSI_STATE_LOGGED_IN ||
1874                                 session->tmf_state != TMF_QUEUED);
1875        if (signal_pending(current))
1876                flush_signals(current);
1877        del_timer_sync(&session->tmf_timer);
1878
1879        mutex_lock(&session->eh_mutex);
1880        spin_lock_bh(&session->frwd_lock);
1881        /* if the session drops it will clean up the task */
1882        if (age != session->age ||
1883            session->state != ISCSI_STATE_LOGGED_IN)
1884                return -ENOTCONN;
1885        return 0;
1886}
1887
1888/*
1889 * Fail commands. session frwd lock held and xmit thread flushed.
1890 */
1891static void fail_scsi_tasks(struct iscsi_conn *conn, u64 lun, int error)
1892{
1893        struct iscsi_session *session = conn->session;
1894        struct iscsi_task *task;
1895        int i;
1896
1897        spin_lock_bh(&session->back_lock);
1898        for (i = 0; i < session->cmds_max; i++) {
1899                task = session->cmds[i];
1900                if (!task->sc || task->state == ISCSI_TASK_FREE)
1901                        continue;
1902
1903                if (lun != -1 && lun != task->sc->device->lun)
1904                        continue;
1905
1906                __iscsi_get_task(task);
1907                spin_unlock_bh(&session->back_lock);
1908
1909                ISCSI_DBG_SESSION(session,
1910                                  "failing sc %p itt 0x%x state %d\n",
1911                                  task->sc, task->itt, task->state);
1912                fail_scsi_task(task, error);
1913
1914                spin_unlock_bh(&session->frwd_lock);
1915                iscsi_put_task(task);
1916                spin_lock_bh(&session->frwd_lock);
1917
1918                spin_lock_bh(&session->back_lock);
1919        }
1920
1921        spin_unlock_bh(&session->back_lock);
1922}
1923
1924/**
1925 * iscsi_suspend_queue - suspend iscsi_queuecommand
1926 * @conn: iscsi conn to stop queueing IO on
1927 *
1928 * This grabs the session frwd_lock to make sure no one is in
1929 * xmit_task/queuecommand, and then sets suspend to prevent
1930 * new commands from being queued. This only needs to be called
1931 * by offload drivers that need to sync a path like ep disconnect
1932 * with the iscsi_queuecommand/xmit_task. To start IO again libiscsi
1933 * will call iscsi_start_tx and iscsi_unblock_session when in FFP.
1934 */
1935void iscsi_suspend_queue(struct iscsi_conn *conn)
1936{
1937        spin_lock_bh(&conn->session->frwd_lock);
1938        set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1939        spin_unlock_bh(&conn->session->frwd_lock);
1940}
1941EXPORT_SYMBOL_GPL(iscsi_suspend_queue);
1942
1943/**
1944 * iscsi_suspend_tx - suspend iscsi_data_xmit
1945 * @conn: iscsi conn tp stop processing IO on.
1946 *
1947 * This function sets the suspend bit to prevent iscsi_data_xmit
1948 * from sending new IO, and if work is queued on the xmit thread
1949 * it will wait for it to be completed.
1950 */
1951void iscsi_suspend_tx(struct iscsi_conn *conn)
1952{
1953        struct Scsi_Host *shost = conn->session->host;
1954        struct iscsi_host *ihost = shost_priv(shost);
1955
1956        set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1957        if (ihost->workq)
1958                flush_workqueue(ihost->workq);
1959}
1960EXPORT_SYMBOL_GPL(iscsi_suspend_tx);
1961
1962static void iscsi_start_tx(struct iscsi_conn *conn)
1963{
1964        clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1965        iscsi_conn_queue_work(conn);
1966}
1967
1968/*
1969 * We want to make sure a ping is in flight. It has timed out.
1970 * And we are not busy processing a pdu that is making
1971 * progress but got started before the ping and is taking a while
1972 * to complete so the ping is just stuck behind it in a queue.
1973 */
1974static int iscsi_has_ping_timed_out(struct iscsi_conn *conn)
1975{
1976        if (READ_ONCE(conn->ping_task) &&
1977            time_before_eq(conn->last_recv + (conn->recv_timeout * HZ) +
1978                           (conn->ping_timeout * HZ), jiffies))
1979                return 1;
1980        else
1981                return 0;
1982}
1983
1984enum blk_eh_timer_return iscsi_eh_cmd_timed_out(struct scsi_cmnd *sc)
1985{
1986        enum blk_eh_timer_return rc = BLK_EH_DONE;
1987        struct iscsi_task *task = NULL, *running_task;
1988        struct iscsi_cls_session *cls_session;
1989        struct iscsi_session *session;
1990        struct iscsi_conn *conn;
1991        int i;
1992
1993        cls_session = starget_to_session(scsi_target(sc->device));
1994        session = cls_session->dd_data;
1995
1996        ISCSI_DBG_EH(session, "scsi cmd %p timedout\n", sc);
1997
1998        spin_lock_bh(&session->frwd_lock);
1999        spin_lock(&session->back_lock);
2000        task = (struct iscsi_task *)sc->SCp.ptr;
2001        if (!task) {
2002                /*
2003                 * Raced with completion. Blk layer has taken ownership
2004                 * so let timeout code complete it now.
2005                 */
2006                rc = BLK_EH_DONE;
2007                spin_unlock(&session->back_lock);
2008                goto done;
2009        }
2010        __iscsi_get_task(task);
2011        spin_unlock(&session->back_lock);
2012
2013        if (session->state != ISCSI_STATE_LOGGED_IN) {
2014                /*
2015                 * During shutdown, if session is prematurely disconnected,
2016                 * recovery won't happen and there will be hung cmds. Not
2017                 * handling cmds would trigger EH, also bad in this case.
2018                 * Instead, handle cmd, allow completion to happen and let
2019                 * upper layer to deal with the result.
2020                 */
2021                if (unlikely(system_state != SYSTEM_RUNNING)) {
2022                        sc->result = DID_NO_CONNECT << 16;
2023                        ISCSI_DBG_EH(session, "sc on shutdown, handled\n");
2024                        rc = BLK_EH_DONE;
2025                        goto done;
2026                }
2027                /*
2028                 * We are probably in the middle of iscsi recovery so let
2029                 * that complete and handle the error.
2030                 */
2031                rc = BLK_EH_RESET_TIMER;
2032                goto done;
2033        }
2034
2035        conn = session->leadconn;
2036        if (!conn) {
2037                /* In the middle of shuting down */
2038                rc = BLK_EH_RESET_TIMER;
2039                goto done;
2040        }
2041
2042        /*
2043         * If we have sent (at least queued to the network layer) a pdu or
2044         * recvd one for the task since the last timeout ask for
2045         * more time. If on the next timeout we have not made progress
2046         * we can check if it is the task or connection when we send the
2047         * nop as a ping.
2048         */
2049        if (time_after(task->last_xfer, task->last_timeout)) {
2050                ISCSI_DBG_EH(session, "Command making progress. Asking "
2051                             "scsi-ml for more time to complete. "
2052                             "Last data xfer at %lu. Last timeout was at "
2053                             "%lu\n.", task->last_xfer, task->last_timeout);
2054                task->have_checked_conn = false;
2055                rc = BLK_EH_RESET_TIMER;
2056                goto done;
2057        }
2058
2059        if (!conn->recv_timeout && !conn->ping_timeout)
2060                goto done;
2061        /*
2062         * if the ping timedout then we are in the middle of cleaning up
2063         * and can let the iscsi eh handle it
2064         */
2065        if (iscsi_has_ping_timed_out(conn)) {
2066                rc = BLK_EH_RESET_TIMER;
2067                goto done;
2068        }
2069
2070        spin_lock(&session->back_lock);
2071        for (i = 0; i < conn->session->cmds_max; i++) {
2072                running_task = conn->session->cmds[i];
2073                if (!running_task->sc || running_task == task ||
2074                     running_task->state != ISCSI_TASK_RUNNING)
2075                        continue;
2076
2077                /*
2078                 * Only check if cmds started before this one have made
2079                 * progress, or this could never fail
2080                 */
2081                if (time_after(running_task->sc->jiffies_at_alloc,
2082                               task->sc->jiffies_at_alloc))
2083                        continue;
2084
2085                if (time_after(running_task->last_xfer, task->last_timeout)) {
2086                        /*
2087                         * This task has not made progress, but a task
2088                         * started before us has transferred data since
2089                         * we started/last-checked. We could be queueing
2090                         * too many tasks or the LU is bad.
2091                         *
2092                         * If the device is bad the cmds ahead of us on
2093                         * other devs will complete, and this loop will
2094                         * eventually fail starting the scsi eh.
2095                         */
2096                        ISCSI_DBG_EH(session, "Command has not made progress "
2097                                     "but commands ahead of it have. "
2098                                     "Asking scsi-ml for more time to "
2099                                     "complete. Our last xfer vs running task "
2100                                     "last xfer %lu/%lu. Last check %lu.\n",
2101                                     task->last_xfer, running_task->last_xfer,
2102                                     task->last_timeout);
2103                        spin_unlock(&session->back_lock);
2104                        rc = BLK_EH_RESET_TIMER;
2105                        goto done;
2106                }
2107        }
2108        spin_unlock(&session->back_lock);
2109
2110        /* Assumes nop timeout is shorter than scsi cmd timeout */
2111        if (task->have_checked_conn)
2112                goto done;
2113
2114        /*
2115         * Checking the transport already or nop from a cmd timeout still
2116         * running
2117         */
2118        if (READ_ONCE(conn->ping_task)) {
2119                task->have_checked_conn = true;
2120                rc = BLK_EH_RESET_TIMER;
2121                goto done;
2122        }
2123
2124        /* Make sure there is a transport check done */
2125        iscsi_send_nopout(conn, NULL);
2126        task->have_checked_conn = true;
2127        rc = BLK_EH_RESET_TIMER;
2128
2129done:
2130        spin_unlock_bh(&session->frwd_lock);
2131
2132        if (task) {
2133                task->last_timeout = jiffies;
2134                iscsi_put_task(task);
2135        }
2136        ISCSI_DBG_EH(session, "return %s\n", rc == BLK_EH_RESET_TIMER ?
2137                     "timer reset" : "shutdown or nh");
2138        return rc;
2139}
2140EXPORT_SYMBOL_GPL(iscsi_eh_cmd_timed_out);
2141
2142static void iscsi_check_transport_timeouts(struct timer_list *t)
2143{
2144        struct iscsi_conn *conn = from_timer(conn, t, transport_timer);
2145        struct iscsi_session *session = conn->session;
2146        unsigned long recv_timeout, next_timeout = 0, last_recv;
2147
2148        spin_lock(&session->frwd_lock);
2149        if (session->state != ISCSI_STATE_LOGGED_IN)
2150                goto done;
2151
2152        recv_timeout = conn->recv_timeout;
2153        if (!recv_timeout)
2154                goto done;
2155
2156        recv_timeout *= HZ;
2157        last_recv = conn->last_recv;
2158
2159        if (iscsi_has_ping_timed_out(conn)) {
2160                iscsi_conn_printk(KERN_ERR, conn, "ping timeout of %d secs "
2161                                  "expired, recv timeout %d, last rx %lu, "
2162                                  "last ping %lu, now %lu\n",
2163                                  conn->ping_timeout, conn->recv_timeout,
2164                                  last_recv, conn->last_ping, jiffies);
2165                spin_unlock(&session->frwd_lock);
2166                iscsi_conn_failure(conn, ISCSI_ERR_NOP_TIMEDOUT);
2167                return;
2168        }
2169
2170        if (time_before_eq(last_recv + recv_timeout, jiffies)) {
2171                /* send a ping to try to provoke some traffic */
2172                ISCSI_DBG_CONN(conn, "Sending nopout as ping\n");
2173                if (iscsi_send_nopout(conn, NULL))
2174                        next_timeout = jiffies + (1 * HZ);
2175                else
2176                        next_timeout = conn->last_ping + (conn->ping_timeout * HZ);
2177        } else
2178                next_timeout = last_recv + recv_timeout;
2179
2180        ISCSI_DBG_CONN(conn, "Setting next tmo %lu\n", next_timeout);
2181        mod_timer(&conn->transport_timer, next_timeout);
2182done:
2183        spin_unlock(&session->frwd_lock);
2184}
2185
2186/**
2187 * iscsi_conn_unbind - prevent queueing to conn.
2188 * @cls_conn: iscsi conn ep is bound to.
2189 * @is_active: is the conn in use for boot or is this for EH/termination
2190 *
2191 * This must be called by drivers implementing the ep_disconnect callout.
2192 * It disables queueing to the connection from libiscsi in preparation for
2193 * an ep_disconnect call.
2194 */
2195void iscsi_conn_unbind(struct iscsi_cls_conn *cls_conn, bool is_active)
2196{
2197        struct iscsi_session *session;
2198        struct iscsi_conn *conn;
2199
2200        if (!cls_conn)
2201                return;
2202
2203        conn = cls_conn->dd_data;
2204        session = conn->session;
2205        /*
2206         * Wait for iscsi_eh calls to exit. We don't wait for the tmf to
2207         * complete or timeout. The caller just wants to know what's running
2208         * is everything that needs to be cleaned up, and no cmds will be
2209         * queued.
2210         */
2211        mutex_lock(&session->eh_mutex);
2212
2213        iscsi_suspend_queue(conn);
2214        iscsi_suspend_tx(conn);
2215
2216        spin_lock_bh(&session->frwd_lock);
2217        if (!is_active) {
2218                /*
2219                 * if logout timed out before userspace could even send a PDU
2220                 * the state might still be in ISCSI_STATE_LOGGED_IN and
2221                 * allowing new cmds and TMFs.
2222                 */
2223                if (session->state == ISCSI_STATE_LOGGED_IN)
2224                        iscsi_set_conn_failed(conn);
2225        }
2226        spin_unlock_bh(&session->frwd_lock);
2227        mutex_unlock(&session->eh_mutex);
2228}
2229EXPORT_SYMBOL_GPL(iscsi_conn_unbind);
2230
2231static void iscsi_prep_abort_task_pdu(struct iscsi_task *task,
2232                                      struct iscsi_tm *hdr)
2233{
2234        memset(hdr, 0, sizeof(*hdr));
2235        hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2236        hdr->flags = ISCSI_TM_FUNC_ABORT_TASK & ISCSI_FLAG_TM_FUNC_MASK;
2237        hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2238        hdr->lun = task->lun;
2239        hdr->rtt = task->hdr_itt;
2240        hdr->refcmdsn = task->cmdsn;
2241}
2242
2243int iscsi_eh_abort(struct scsi_cmnd *sc)
2244{
2245        struct iscsi_cls_session *cls_session;
2246        struct iscsi_session *session;
2247        struct iscsi_conn *conn;
2248        struct iscsi_task *task;
2249        struct iscsi_tm *hdr;
2250        int age;
2251
2252        cls_session = starget_to_session(scsi_target(sc->device));
2253        session = cls_session->dd_data;
2254
2255        ISCSI_DBG_EH(session, "aborting sc %p\n", sc);
2256
2257        mutex_lock(&session->eh_mutex);
2258        spin_lock_bh(&session->frwd_lock);
2259        /*
2260         * if session was ISCSI_STATE_IN_RECOVERY then we may not have
2261         * got the command.
2262         */
2263        if (!sc->SCp.ptr) {
2264                ISCSI_DBG_EH(session, "sc never reached iscsi layer or "
2265                                      "it completed.\n");
2266                spin_unlock_bh(&session->frwd_lock);
2267                mutex_unlock(&session->eh_mutex);
2268                return SUCCESS;
2269        }
2270
2271        /*
2272         * If we are not logged in or we have started a new session
2273         * then let the host reset code handle this
2274         */
2275        if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN ||
2276            sc->SCp.phase != session->age) {
2277                spin_unlock_bh(&session->frwd_lock);
2278                mutex_unlock(&session->eh_mutex);
2279                ISCSI_DBG_EH(session, "failing abort due to dropped "
2280                                  "session.\n");
2281                return FAILED;
2282        }
2283
2284        conn = session->leadconn;
2285        iscsi_get_conn(conn->cls_conn);
2286        conn->eh_abort_cnt++;
2287        age = session->age;
2288
2289        spin_lock(&session->back_lock);
2290        task = (struct iscsi_task *)sc->SCp.ptr;
2291        if (!task || !task->sc) {
2292                /* task completed before time out */
2293                ISCSI_DBG_EH(session, "sc completed while abort in progress\n");
2294
2295                spin_unlock(&session->back_lock);
2296                goto success;
2297        }
2298        ISCSI_DBG_EH(session, "aborting [sc %p itt 0x%x]\n", sc, task->itt);
2299        __iscsi_get_task(task);
2300        spin_unlock(&session->back_lock);
2301
2302        if (task->state == ISCSI_TASK_PENDING) {
2303                fail_scsi_task(task, DID_ABORT);
2304                goto success;
2305        }
2306
2307        /* only have one tmf outstanding at a time */
2308        if (session->tmf_state != TMF_INITIAL)
2309                goto failed;
2310        session->tmf_state = TMF_QUEUED;
2311
2312        hdr = &session->tmhdr;
2313        iscsi_prep_abort_task_pdu(task, hdr);
2314
2315        if (iscsi_exec_task_mgmt_fn(conn, hdr, age, session->abort_timeout))
2316                goto failed;
2317
2318        switch (session->tmf_state) {
2319        case TMF_SUCCESS:
2320                spin_unlock_bh(&session->frwd_lock);
2321                /*
2322                 * stop tx side incase the target had sent a abort rsp but
2323                 * the initiator was still writing out data.
2324                 */
2325                iscsi_suspend_tx(conn);
2326                /*
2327                 * we do not stop the recv side because targets have been
2328                 * good and have never sent us a successful tmf response
2329                 * then sent more data for the cmd.
2330                 */
2331                spin_lock_bh(&session->frwd_lock);
2332                fail_scsi_task(task, DID_ABORT);
2333                session->tmf_state = TMF_INITIAL;
2334                memset(hdr, 0, sizeof(*hdr));
2335                spin_unlock_bh(&session->frwd_lock);
2336                iscsi_start_tx(conn);
2337                goto success_unlocked;
2338        case TMF_TIMEDOUT:
2339                session->running_aborted_task = task;
2340                spin_unlock_bh(&session->frwd_lock);
2341                iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2342                goto failed_unlocked;
2343        case TMF_NOT_FOUND:
2344                if (iscsi_task_is_completed(task)) {
2345                        session->tmf_state = TMF_INITIAL;
2346                        memset(hdr, 0, sizeof(*hdr));
2347                        /* task completed before tmf abort response */
2348                        ISCSI_DBG_EH(session, "sc completed while abort in "
2349                                              "progress\n");
2350                        goto success;
2351                }
2352                fallthrough;
2353        default:
2354                session->tmf_state = TMF_INITIAL;
2355                goto failed;
2356        }
2357
2358success:
2359        spin_unlock_bh(&session->frwd_lock);
2360success_unlocked:
2361        ISCSI_DBG_EH(session, "abort success [sc %p itt 0x%x]\n",
2362                     sc, task->itt);
2363        iscsi_put_task(task);
2364        iscsi_put_conn(conn->cls_conn);
2365        mutex_unlock(&session->eh_mutex);
2366        return SUCCESS;
2367
2368failed:
2369        spin_unlock_bh(&session->frwd_lock);
2370failed_unlocked:
2371        ISCSI_DBG_EH(session, "abort failed [sc %p itt 0x%x]\n", sc,
2372                     task ? task->itt : 0);
2373        /*
2374         * The driver might be accessing the task so hold the ref. The conn
2375         * stop cleanup will drop the ref after ep_disconnect so we know the
2376         * driver's no longer touching the task.
2377         */
2378        if (!session->running_aborted_task)
2379                iscsi_put_task(task);
2380
2381        iscsi_put_conn(conn->cls_conn);
2382        mutex_unlock(&session->eh_mutex);
2383        return FAILED;
2384}
2385EXPORT_SYMBOL_GPL(iscsi_eh_abort);
2386
2387static void iscsi_prep_lun_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
2388{
2389        memset(hdr, 0, sizeof(*hdr));
2390        hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2391        hdr->flags = ISCSI_TM_FUNC_LOGICAL_UNIT_RESET & ISCSI_FLAG_TM_FUNC_MASK;
2392        hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2393        int_to_scsilun(sc->device->lun, &hdr->lun);
2394        hdr->rtt = RESERVED_ITT;
2395}
2396
2397int iscsi_eh_device_reset(struct scsi_cmnd *sc)
2398{
2399        struct iscsi_cls_session *cls_session;
2400        struct iscsi_session *session;
2401        struct iscsi_conn *conn;
2402        struct iscsi_tm *hdr;
2403        int rc = FAILED;
2404
2405        cls_session = starget_to_session(scsi_target(sc->device));
2406        session = cls_session->dd_data;
2407
2408        ISCSI_DBG_EH(session, "LU Reset [sc %p lun %llu]\n", sc,
2409                     sc->device->lun);
2410
2411        mutex_lock(&session->eh_mutex);
2412        spin_lock_bh(&session->frwd_lock);
2413        /*
2414         * Just check if we are not logged in. We cannot check for
2415         * the phase because the reset could come from a ioctl.
2416         */
2417        if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
2418                goto unlock;
2419        conn = session->leadconn;
2420
2421        /* only have one tmf outstanding at a time */
2422        if (session->tmf_state != TMF_INITIAL)
2423                goto unlock;
2424        session->tmf_state = TMF_QUEUED;
2425
2426        hdr = &session->tmhdr;
2427        iscsi_prep_lun_reset_pdu(sc, hdr);
2428
2429        if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
2430                                    session->lu_reset_timeout)) {
2431                rc = FAILED;
2432                goto unlock;
2433        }
2434
2435        switch (session->tmf_state) {
2436        case TMF_SUCCESS:
2437                break;
2438        case TMF_TIMEDOUT:
2439                spin_unlock_bh(&session->frwd_lock);
2440                iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2441                goto done;
2442        default:
2443                session->tmf_state = TMF_INITIAL;
2444                goto unlock;
2445        }
2446
2447        rc = SUCCESS;
2448        spin_unlock_bh(&session->frwd_lock);
2449
2450        iscsi_suspend_tx(conn);
2451
2452        spin_lock_bh(&session->frwd_lock);
2453        memset(hdr, 0, sizeof(*hdr));
2454        fail_scsi_tasks(conn, sc->device->lun, DID_ERROR);
2455        session->tmf_state = TMF_INITIAL;
2456        spin_unlock_bh(&session->frwd_lock);
2457
2458        iscsi_start_tx(conn);
2459        goto done;
2460
2461unlock:
2462        spin_unlock_bh(&session->frwd_lock);
2463done:
2464        ISCSI_DBG_EH(session, "dev reset result = %s\n",
2465                     rc == SUCCESS ? "SUCCESS" : "FAILED");
2466        mutex_unlock(&session->eh_mutex);
2467        return rc;
2468}
2469EXPORT_SYMBOL_GPL(iscsi_eh_device_reset);
2470
2471void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
2472{
2473        struct iscsi_session *session = cls_session->dd_data;
2474
2475        spin_lock_bh(&session->frwd_lock);
2476        if (session->state != ISCSI_STATE_LOGGED_IN) {
2477                session->state = ISCSI_STATE_RECOVERY_FAILED;
2478                wake_up(&session->ehwait);
2479        }
2480        spin_unlock_bh(&session->frwd_lock);
2481}
2482EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
2483
2484/**
2485 * iscsi_eh_session_reset - drop session and attempt relogin
2486 * @sc: scsi command
2487 *
2488 * This function will wait for a relogin, session termination from
2489 * userspace, or a recovery/replacement timeout.
2490 */
2491int iscsi_eh_session_reset(struct scsi_cmnd *sc)
2492{
2493        struct iscsi_cls_session *cls_session;
2494        struct iscsi_session *session;
2495        struct iscsi_conn *conn;
2496
2497        cls_session = starget_to_session(scsi_target(sc->device));
2498        session = cls_session->dd_data;
2499
2500        mutex_lock(&session->eh_mutex);
2501        spin_lock_bh(&session->frwd_lock);
2502        if (session->state == ISCSI_STATE_TERMINATE) {
2503failed:
2504                ISCSI_DBG_EH(session,
2505                             "failing session reset: Could not log back into "
2506                             "%s [age %d]\n", session->targetname,
2507                             session->age);
2508                spin_unlock_bh(&session->frwd_lock);
2509                mutex_unlock(&session->eh_mutex);
2510                return FAILED;
2511        }
2512
2513        conn = session->leadconn;
2514        iscsi_get_conn(conn->cls_conn);
2515
2516        spin_unlock_bh(&session->frwd_lock);
2517        mutex_unlock(&session->eh_mutex);
2518
2519        iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2520        iscsi_put_conn(conn->cls_conn);
2521
2522        ISCSI_DBG_EH(session, "wait for relogin\n");
2523        wait_event_interruptible(session->ehwait,
2524                                 session->state == ISCSI_STATE_TERMINATE ||
2525                                 session->state == ISCSI_STATE_LOGGED_IN ||
2526                                 session->state == ISCSI_STATE_RECOVERY_FAILED);
2527        if (signal_pending(current))
2528                flush_signals(current);
2529
2530        mutex_lock(&session->eh_mutex);
2531        spin_lock_bh(&session->frwd_lock);
2532        if (session->state == ISCSI_STATE_LOGGED_IN) {
2533                ISCSI_DBG_EH(session,
2534                             "session reset succeeded for %s,%s\n",
2535                             session->targetname, conn->persistent_address);
2536        } else
2537                goto failed;
2538        spin_unlock_bh(&session->frwd_lock);
2539        mutex_unlock(&session->eh_mutex);
2540        return SUCCESS;
2541}
2542EXPORT_SYMBOL_GPL(iscsi_eh_session_reset);
2543
2544static void iscsi_prep_tgt_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
2545{
2546        memset(hdr, 0, sizeof(*hdr));
2547        hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2548        hdr->flags = ISCSI_TM_FUNC_TARGET_WARM_RESET & ISCSI_FLAG_TM_FUNC_MASK;
2549        hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2550        hdr->rtt = RESERVED_ITT;
2551}
2552
2553/**
2554 * iscsi_eh_target_reset - reset target
2555 * @sc: scsi command
2556 *
2557 * This will attempt to send a warm target reset.
2558 */
2559static int iscsi_eh_target_reset(struct scsi_cmnd *sc)
2560{
2561        struct iscsi_cls_session *cls_session;
2562        struct iscsi_session *session;
2563        struct iscsi_conn *conn;
2564        struct iscsi_tm *hdr;
2565        int rc = FAILED;
2566
2567        cls_session = starget_to_session(scsi_target(sc->device));
2568        session = cls_session->dd_data;
2569
2570        ISCSI_DBG_EH(session, "tgt Reset [sc %p tgt %s]\n", sc,
2571                     session->targetname);
2572
2573        mutex_lock(&session->eh_mutex);
2574        spin_lock_bh(&session->frwd_lock);
2575        /*
2576         * Just check if we are not logged in. We cannot check for
2577         * the phase because the reset could come from a ioctl.
2578         */
2579        if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
2580                goto unlock;
2581        conn = session->leadconn;
2582
2583        /* only have one tmf outstanding at a time */
2584        if (session->tmf_state != TMF_INITIAL)
2585                goto unlock;
2586        session->tmf_state = TMF_QUEUED;
2587
2588        hdr = &session->tmhdr;
2589        iscsi_prep_tgt_reset_pdu(sc, hdr);
2590
2591        if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
2592                                    session->tgt_reset_timeout)) {
2593                rc = FAILED;
2594                goto unlock;
2595        }
2596
2597        switch (session->tmf_state) {
2598        case TMF_SUCCESS:
2599                break;
2600        case TMF_TIMEDOUT:
2601                spin_unlock_bh(&session->frwd_lock);
2602                iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2603                goto done;
2604        default:
2605                session->tmf_state = TMF_INITIAL;
2606                goto unlock;
2607        }
2608
2609        rc = SUCCESS;
2610        spin_unlock_bh(&session->frwd_lock);
2611
2612        iscsi_suspend_tx(conn);
2613
2614        spin_lock_bh(&session->frwd_lock);
2615        memset(hdr, 0, sizeof(*hdr));
2616        fail_scsi_tasks(conn, -1, DID_ERROR);
2617        session->tmf_state = TMF_INITIAL;
2618        spin_unlock_bh(&session->frwd_lock);
2619
2620        iscsi_start_tx(conn);
2621        goto done;
2622
2623unlock:
2624        spin_unlock_bh(&session->frwd_lock);
2625done:
2626        ISCSI_DBG_EH(session, "tgt %s reset result = %s\n", session->targetname,
2627                     rc == SUCCESS ? "SUCCESS" : "FAILED");
2628        mutex_unlock(&session->eh_mutex);
2629        return rc;
2630}
2631
2632/**
2633 * iscsi_eh_recover_target - reset target and possibly the session
2634 * @sc: scsi command
2635 *
2636 * This will attempt to send a warm target reset. If that fails,
2637 * we will escalate to ERL0 session recovery.
2638 */
2639int iscsi_eh_recover_target(struct scsi_cmnd *sc)
2640{
2641        int rc;
2642
2643        rc = iscsi_eh_target_reset(sc);
2644        if (rc == FAILED)
2645                rc = iscsi_eh_session_reset(sc);
2646        return rc;
2647}
2648EXPORT_SYMBOL_GPL(iscsi_eh_recover_target);
2649
2650/*
2651 * Pre-allocate a pool of @max items of @item_size. By default, the pool
2652 * should be accessed via kfifo_{get,put} on q->queue.
2653 * Optionally, the caller can obtain the array of object pointers
2654 * by passing in a non-NULL @items pointer
2655 */
2656int
2657iscsi_pool_init(struct iscsi_pool *q, int max, void ***items, int item_size)
2658{
2659        int i, num_arrays = 1;
2660
2661        memset(q, 0, sizeof(*q));
2662
2663        q->max = max;
2664
2665        /* If the user passed an items pointer, he wants a copy of
2666         * the array. */
2667        if (items)
2668                num_arrays++;
2669        q->pool = kvcalloc(num_arrays * max, sizeof(void *), GFP_KERNEL);
2670        if (q->pool == NULL)
2671                return -ENOMEM;
2672
2673        kfifo_init(&q->queue, (void*)q->pool, max * sizeof(void*));
2674
2675        for (i = 0; i < max; i++) {
2676                q->pool[i] = kzalloc(item_size, GFP_KERNEL);
2677                if (q->pool[i] == NULL) {
2678                        q->max = i;
2679                        goto enomem;
2680                }
2681                kfifo_in(&q->queue, (void*)&q->pool[i], sizeof(void*));
2682        }
2683
2684        if (items) {
2685                *items = q->pool + max;
2686                memcpy(*items, q->pool, max * sizeof(void *));
2687        }
2688
2689        return 0;
2690
2691enomem:
2692        iscsi_pool_free(q);
2693        return -ENOMEM;
2694}
2695EXPORT_SYMBOL_GPL(iscsi_pool_init);
2696
2697void iscsi_pool_free(struct iscsi_pool *q)
2698{
2699        int i;
2700
2701        for (i = 0; i < q->max; i++)
2702                kfree(q->pool[i]);
2703        kvfree(q->pool);
2704}
2705EXPORT_SYMBOL_GPL(iscsi_pool_free);
2706
2707int iscsi_host_get_max_scsi_cmds(struct Scsi_Host *shost,
2708                                 uint16_t requested_cmds_max)
2709{
2710        int scsi_cmds, total_cmds = requested_cmds_max;
2711
2712check:
2713        if (!total_cmds)
2714                total_cmds = ISCSI_DEF_XMIT_CMDS_MAX;
2715        /*
2716         * The iscsi layer needs some tasks for nop handling and tmfs,
2717         * so the cmds_max must at least be greater than ISCSI_MGMT_CMDS_MAX
2718         * + 1 command for scsi IO.
2719         */
2720        if (total_cmds < ISCSI_TOTAL_CMDS_MIN) {
2721                printk(KERN_ERR "iscsi: invalid max cmds of %d. Must be a power of two that is at least %d.\n",
2722                       total_cmds, ISCSI_TOTAL_CMDS_MIN);
2723                return -EINVAL;
2724        }
2725
2726        if (total_cmds > ISCSI_TOTAL_CMDS_MAX) {
2727                printk(KERN_INFO "iscsi: invalid max cmds of %d. Must be a power of 2 less than or equal to %d. Using %d.\n",
2728                       requested_cmds_max, ISCSI_TOTAL_CMDS_MAX,
2729                       ISCSI_TOTAL_CMDS_MAX);
2730                total_cmds = ISCSI_TOTAL_CMDS_MAX;
2731        }
2732
2733        if (!is_power_of_2(total_cmds)) {
2734                total_cmds = rounddown_pow_of_two(total_cmds);
2735                if (total_cmds < ISCSI_TOTAL_CMDS_MIN) {
2736                        printk(KERN_ERR "iscsi: invalid max cmds of %d. Must be a power of 2 greater than %d.\n", requested_cmds_max, ISCSI_TOTAL_CMDS_MIN);
2737                        return -EINVAL;
2738                }
2739
2740                printk(KERN_INFO "iscsi: invalid max cmds %d. Must be a power of 2. Rounding max cmds down to %d.\n",
2741                       requested_cmds_max, total_cmds);
2742        }
2743
2744        scsi_cmds = total_cmds - ISCSI_MGMT_CMDS_MAX;
2745        if (shost->can_queue && scsi_cmds > shost->can_queue) {
2746                total_cmds = shost->can_queue;
2747
2748                printk(KERN_INFO "iscsi: requested max cmds %u is higher than driver limit. Using driver limit %u\n",
2749                       requested_cmds_max, shost->can_queue);
2750                goto check;
2751        }
2752
2753        return scsi_cmds;
2754}
2755EXPORT_SYMBOL_GPL(iscsi_host_get_max_scsi_cmds);
2756
2757/**
2758 * iscsi_host_add - add host to system
2759 * @shost: scsi host
2760 * @pdev: parent device
2761 *
2762 * This should be called by partial offload and software iscsi drivers
2763 * to add a host to the system.
2764 */
2765int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev)
2766{
2767        if (!shost->can_queue)
2768                shost->can_queue = ISCSI_DEF_XMIT_CMDS_MAX;
2769
2770        if (!shost->cmd_per_lun)
2771                shost->cmd_per_lun = ISCSI_DEF_CMD_PER_LUN;
2772
2773        return scsi_add_host(shost, pdev);
2774}
2775EXPORT_SYMBOL_GPL(iscsi_host_add);
2776
2777/**
2778 * iscsi_host_alloc - allocate a host and driver data
2779 * @sht: scsi host template
2780 * @dd_data_size: driver host data size
2781 * @xmit_can_sleep: bool indicating if LLD will queue IO from a work queue
2782 *
2783 * This should be called by partial offload and software iscsi drivers.
2784 * To access the driver specific memory use the iscsi_host_priv() macro.
2785 */
2786struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
2787                                   int dd_data_size, bool xmit_can_sleep)
2788{
2789        struct Scsi_Host *shost;
2790        struct iscsi_host *ihost;
2791
2792        shost = scsi_host_alloc(sht, sizeof(struct iscsi_host) + dd_data_size);
2793        if (!shost)
2794                return NULL;
2795        ihost = shost_priv(shost);
2796
2797        if (xmit_can_sleep) {
2798                snprintf(ihost->workq_name, sizeof(ihost->workq_name),
2799                        "iscsi_q_%d", shost->host_no);
2800                ihost->workq = alloc_workqueue("%s",
2801                        WQ_SYSFS | __WQ_LEGACY | WQ_MEM_RECLAIM | WQ_UNBOUND,
2802                        1, ihost->workq_name);
2803                if (!ihost->workq)
2804                        goto free_host;
2805        }
2806
2807        spin_lock_init(&ihost->lock);
2808        ihost->state = ISCSI_HOST_SETUP;
2809        ihost->num_sessions = 0;
2810        init_waitqueue_head(&ihost->session_removal_wq);
2811        return shost;
2812
2813free_host:
2814        scsi_host_put(shost);
2815        return NULL;
2816}
2817EXPORT_SYMBOL_GPL(iscsi_host_alloc);
2818
2819static void iscsi_notify_host_removed(struct iscsi_cls_session *cls_session)
2820{
2821        iscsi_session_failure(cls_session->dd_data, ISCSI_ERR_INVALID_HOST);
2822}
2823
2824/**
2825 * iscsi_host_remove - remove host and sessions
2826 * @shost: scsi host
2827 *
2828 * If there are any sessions left, this will initiate the removal and wait
2829 * for the completion.
2830 */
2831void iscsi_host_remove(struct Scsi_Host *shost)
2832{
2833        struct iscsi_host *ihost = shost_priv(shost);
2834        unsigned long flags;
2835
2836        spin_lock_irqsave(&ihost->lock, flags);
2837        ihost->state = ISCSI_HOST_REMOVED;
2838        spin_unlock_irqrestore(&ihost->lock, flags);
2839
2840        iscsi_host_for_each_session(shost, iscsi_notify_host_removed);
2841        wait_event_interruptible(ihost->session_removal_wq,
2842                                 ihost->num_sessions == 0);
2843        if (signal_pending(current))
2844                flush_signals(current);
2845
2846        scsi_remove_host(shost);
2847}
2848EXPORT_SYMBOL_GPL(iscsi_host_remove);
2849
2850void iscsi_host_free(struct Scsi_Host *shost)
2851{
2852        struct iscsi_host *ihost = shost_priv(shost);
2853
2854        if (ihost->workq)
2855                destroy_workqueue(ihost->workq);
2856
2857        kfree(ihost->netdev);
2858        kfree(ihost->hwaddress);
2859        kfree(ihost->initiatorname);
2860        scsi_host_put(shost);
2861}
2862EXPORT_SYMBOL_GPL(iscsi_host_free);
2863
2864static void iscsi_host_dec_session_cnt(struct Scsi_Host *shost)
2865{
2866        struct iscsi_host *ihost = shost_priv(shost);
2867        unsigned long flags;
2868
2869        shost = scsi_host_get(shost);
2870        if (!shost) {
2871                printk(KERN_ERR "Invalid state. Cannot notify host removal "
2872                      "of session teardown event because host already "
2873                      "removed.\n");
2874                return;
2875        }
2876
2877        spin_lock_irqsave(&ihost->lock, flags);
2878        ihost->num_sessions--;
2879        if (ihost->num_sessions == 0)
2880                wake_up(&ihost->session_removal_wq);
2881        spin_unlock_irqrestore(&ihost->lock, flags);
2882        scsi_host_put(shost);
2883}
2884
2885/**
2886 * iscsi_session_setup - create iscsi cls session and host and session
2887 * @iscsit: iscsi transport template
2888 * @shost: scsi host
2889 * @cmds_max: session can queue
2890 * @dd_size: private driver data size, added to session allocation size
2891 * @cmd_task_size: LLD task private data size
2892 * @initial_cmdsn: initial CmdSN
2893 * @id: target ID to add to this session
2894 *
2895 * This can be used by software iscsi_transports that allocate
2896 * a session per scsi host.
2897 *
2898 * Callers should set cmds_max to the largest total numer (mgmt + scsi) of
2899 * tasks they support. The iscsi layer reserves ISCSI_MGMT_CMDS_MAX tasks
2900 * for nop handling and login/logout requests.
2901 */
2902struct iscsi_cls_session *
2903iscsi_session_setup(struct iscsi_transport *iscsit, struct Scsi_Host *shost,
2904                    uint16_t cmds_max, int dd_size, int cmd_task_size,
2905                    uint32_t initial_cmdsn, unsigned int id)
2906{
2907        struct iscsi_host *ihost = shost_priv(shost);
2908        struct iscsi_session *session;
2909        struct iscsi_cls_session *cls_session;
2910        int cmd_i, scsi_cmds;
2911        unsigned long flags;
2912
2913        spin_lock_irqsave(&ihost->lock, flags);
2914        if (ihost->state == ISCSI_HOST_REMOVED) {
2915                spin_unlock_irqrestore(&ihost->lock, flags);
2916                return NULL;
2917        }
2918        ihost->num_sessions++;
2919        spin_unlock_irqrestore(&ihost->lock, flags);
2920
2921        scsi_cmds = iscsi_host_get_max_scsi_cmds(shost, cmds_max);
2922        if (scsi_cmds < 0)
2923                goto dec_session_count;
2924
2925        cls_session = iscsi_alloc_session(shost, iscsit,
2926                                          sizeof(struct iscsi_session) +
2927                                          dd_size);
2928        if (!cls_session)
2929                goto dec_session_count;
2930        session = cls_session->dd_data;
2931        session->cls_session = cls_session;
2932        session->host = shost;
2933        session->state = ISCSI_STATE_FREE;
2934        session->fast_abort = 1;
2935        session->tgt_reset_timeout = 30;
2936        session->lu_reset_timeout = 15;
2937        session->abort_timeout = 10;
2938        session->scsi_cmds_max = scsi_cmds;
2939        session->cmds_max = scsi_cmds + ISCSI_MGMT_CMDS_MAX;
2940        session->queued_cmdsn = session->cmdsn = initial_cmdsn;
2941        session->exp_cmdsn = initial_cmdsn + 1;
2942        session->max_cmdsn = initial_cmdsn + 1;
2943        session->max_r2t = 1;
2944        session->tt = iscsit;
2945        session->dd_data = cls_session->dd_data + sizeof(*session);
2946
2947        session->tmf_state = TMF_INITIAL;
2948        timer_setup(&session->tmf_timer, iscsi_tmf_timedout, 0);
2949        mutex_init(&session->eh_mutex);
2950
2951        spin_lock_init(&session->frwd_lock);
2952        spin_lock_init(&session->back_lock);
2953
2954        /* initialize SCSI PDU commands pool */
2955        if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
2956                            (void***)&session->cmds,
2957                            cmd_task_size + sizeof(struct iscsi_task)))
2958                goto cmdpool_alloc_fail;
2959
2960        /* pre-format cmds pool with ITT */
2961        for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
2962                struct iscsi_task *task = session->cmds[cmd_i];
2963
2964                if (cmd_task_size)
2965                        task->dd_data = &task[1];
2966                task->itt = cmd_i;
2967                task->state = ISCSI_TASK_FREE;
2968                INIT_LIST_HEAD(&task->running);
2969        }
2970
2971        if (!try_module_get(iscsit->owner))
2972                goto module_get_fail;
2973
2974        if (iscsi_add_session(cls_session, id))
2975                goto cls_session_fail;
2976
2977        return cls_session;
2978
2979cls_session_fail:
2980        module_put(iscsit->owner);
2981module_get_fail:
2982        iscsi_pool_free(&session->cmdpool);
2983cmdpool_alloc_fail:
2984        iscsi_free_session(cls_session);
2985dec_session_count:
2986        iscsi_host_dec_session_cnt(shost);
2987        return NULL;
2988}
2989EXPORT_SYMBOL_GPL(iscsi_session_setup);
2990
2991/**
2992 * iscsi_session_teardown - destroy session, host, and cls_session
2993 * @cls_session: iscsi session
2994 */
2995void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
2996{
2997        struct iscsi_session *session = cls_session->dd_data;
2998        struct module *owner = cls_session->transport->owner;
2999        struct Scsi_Host *shost = session->host;
3000
3001        iscsi_remove_session(cls_session);
3002
3003        iscsi_pool_free(&session->cmdpool);
3004        kfree(session->password);
3005        kfree(session->password_in);
3006        kfree(session->username);
3007        kfree(session->username_in);
3008        kfree(session->targetname);
3009        kfree(session->targetalias);
3010        kfree(session->initiatorname);
3011        kfree(session->boot_root);
3012        kfree(session->boot_nic);
3013        kfree(session->boot_target);
3014        kfree(session->ifacename);
3015        kfree(session->portal_type);
3016        kfree(session->discovery_parent_type);
3017
3018        iscsi_free_session(cls_session);
3019
3020        iscsi_host_dec_session_cnt(shost);
3021        module_put(owner);
3022}
3023EXPORT_SYMBOL_GPL(iscsi_session_teardown);
3024
3025/**
3026 * iscsi_conn_setup - create iscsi_cls_conn and iscsi_conn
3027 * @cls_session: iscsi_cls_session
3028 * @dd_size: private driver data size
3029 * @conn_idx: cid
3030 */
3031struct iscsi_cls_conn *
3032iscsi_conn_setup(struct iscsi_cls_session *cls_session, int dd_size,
3033                 uint32_t conn_idx)
3034{
3035        struct iscsi_session *session = cls_session->dd_data;
3036        struct iscsi_conn *conn;
3037        struct iscsi_cls_conn *cls_conn;
3038        char *data;
3039
3040        cls_conn = iscsi_create_conn(cls_session, sizeof(*conn) + dd_size,
3041                                     conn_idx);
3042        if (!cls_conn)
3043                return NULL;
3044        conn = cls_conn->dd_data;
3045        memset(conn, 0, sizeof(*conn) + dd_size);
3046
3047        conn->dd_data = cls_conn->dd_data + sizeof(*conn);
3048        conn->session = session;
3049        conn->cls_conn = cls_conn;
3050        conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
3051        conn->id = conn_idx;
3052        conn->exp_statsn = 0;
3053
3054        timer_setup(&conn->transport_timer, iscsi_check_transport_timeouts, 0);
3055
3056        INIT_LIST_HEAD(&conn->mgmtqueue);
3057        INIT_LIST_HEAD(&conn->cmdqueue);
3058        INIT_LIST_HEAD(&conn->requeue);
3059        INIT_WORK(&conn->xmitwork, iscsi_xmitworker);
3060
3061        /* allocate login_task used for the login/text sequences */
3062        spin_lock_bh(&session->frwd_lock);
3063        if (!kfifo_out(&session->cmdpool.queue,
3064                         (void*)&conn->login_task,
3065                         sizeof(void*))) {
3066                spin_unlock_bh(&session->frwd_lock);
3067                goto login_task_alloc_fail;
3068        }
3069        spin_unlock_bh(&session->frwd_lock);
3070
3071        data = (char *) __get_free_pages(GFP_KERNEL,
3072                                         get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
3073        if (!data)
3074                goto login_task_data_alloc_fail;
3075        conn->login_task->data = conn->data = data;
3076
3077        init_waitqueue_head(&session->ehwait);
3078
3079        return cls_conn;
3080
3081login_task_data_alloc_fail:
3082        kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
3083                    sizeof(void*));
3084login_task_alloc_fail:
3085        iscsi_destroy_conn(cls_conn);
3086        return NULL;
3087}
3088EXPORT_SYMBOL_GPL(iscsi_conn_setup);
3089
3090/**
3091 * iscsi_conn_teardown - teardown iscsi connection
3092 * @cls_conn: iscsi class connection
3093 *
3094 * TODO: we may need to make this into a two step process
3095 * like scsi-mls remove + put host
3096 */
3097void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
3098{
3099        struct iscsi_conn *conn = cls_conn->dd_data;
3100        struct iscsi_session *session = conn->session;
3101
3102        del_timer_sync(&conn->transport_timer);
3103
3104        mutex_lock(&session->eh_mutex);
3105        spin_lock_bh(&session->frwd_lock);
3106        conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
3107        if (session->leadconn == conn) {
3108                /*
3109                 * leading connection? then give up on recovery.
3110                 */
3111                session->state = ISCSI_STATE_TERMINATE;
3112                wake_up(&session->ehwait);
3113        }
3114        spin_unlock_bh(&session->frwd_lock);
3115
3116        /* flush queued up work because we free the connection below */
3117        iscsi_suspend_tx(conn);
3118
3119        spin_lock_bh(&session->frwd_lock);
3120        free_pages((unsigned long) conn->data,
3121                   get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
3122        kfree(conn->persistent_address);
3123        kfree(conn->local_ipaddr);
3124        /* regular RX path uses back_lock */
3125        spin_lock_bh(&session->back_lock);
3126        kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
3127                    sizeof(void*));
3128        spin_unlock_bh(&session->back_lock);
3129        if (session->leadconn == conn)
3130                session->leadconn = NULL;
3131        spin_unlock_bh(&session->frwd_lock);
3132        mutex_unlock(&session->eh_mutex);
3133
3134        iscsi_destroy_conn(cls_conn);
3135}
3136EXPORT_SYMBOL_GPL(iscsi_conn_teardown);
3137
3138int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
3139{
3140        struct iscsi_conn *conn = cls_conn->dd_data;
3141        struct iscsi_session *session = conn->session;
3142
3143        if (!session) {
3144                iscsi_conn_printk(KERN_ERR, conn,
3145                                  "can't start unbound connection\n");
3146                return -EPERM;
3147        }
3148
3149        if ((session->imm_data_en || !session->initial_r2t_en) &&
3150             session->first_burst > session->max_burst) {
3151                iscsi_conn_printk(KERN_INFO, conn, "invalid burst lengths: "
3152                                  "first_burst %d max_burst %d\n",
3153                                  session->first_burst, session->max_burst);
3154                return -EINVAL;
3155        }
3156
3157        if (conn->ping_timeout && !conn->recv_timeout) {
3158                iscsi_conn_printk(KERN_ERR, conn, "invalid recv timeout of "
3159                                  "zero. Using 5 seconds\n.");
3160                conn->recv_timeout = 5;
3161        }
3162
3163        if (conn->recv_timeout && !conn->ping_timeout) {
3164                iscsi_conn_printk(KERN_ERR, conn, "invalid ping timeout of "
3165                                  "zero. Using 5 seconds.\n");
3166                conn->ping_timeout = 5;
3167        }
3168
3169        spin_lock_bh(&session->frwd_lock);
3170        conn->c_stage = ISCSI_CONN_STARTED;
3171        session->state = ISCSI_STATE_LOGGED_IN;
3172        session->queued_cmdsn = session->cmdsn;
3173
3174        conn->last_recv = jiffies;
3175        conn->last_ping = jiffies;
3176        if (conn->recv_timeout && conn->ping_timeout)
3177                mod_timer(&conn->transport_timer,
3178                          jiffies + (conn->recv_timeout * HZ));
3179
3180        switch(conn->stop_stage) {
3181        case STOP_CONN_RECOVER:
3182                /*
3183                 * unblock eh_abort() if it is blocked. re-try all
3184                 * commands after successful recovery
3185                 */
3186                conn->stop_stage = 0;
3187                session->tmf_state = TMF_INITIAL;
3188                session->age++;
3189                if (session->age == 16)
3190                        session->age = 0;
3191                break;
3192        case STOP_CONN_TERM:
3193                conn->stop_stage = 0;
3194                break;
3195        default:
3196                break;
3197        }
3198        spin_unlock_bh(&session->frwd_lock);
3199
3200        iscsi_unblock_session(session->cls_session);
3201        wake_up(&session->ehwait);
3202        return 0;
3203}
3204EXPORT_SYMBOL_GPL(iscsi_conn_start);
3205
3206static void
3207fail_mgmt_tasks(struct iscsi_session *session, struct iscsi_conn *conn)
3208{
3209        struct iscsi_task *task;
3210        int i, state;
3211
3212        for (i = 0; i < conn->session->cmds_max; i++) {
3213                task = conn->session->cmds[i];
3214                if (task->sc)
3215                        continue;
3216
3217                if (task->state == ISCSI_TASK_FREE)
3218                        continue;
3219
3220                ISCSI_DBG_SESSION(conn->session,
3221                                  "failing mgmt itt 0x%x state %d\n",
3222                                  task->itt, task->state);
3223
3224                spin_lock_bh(&session->back_lock);
3225                if (cleanup_queued_task(task)) {
3226                        spin_unlock_bh(&session->back_lock);
3227                        continue;
3228                }
3229
3230                state = ISCSI_TASK_ABRT_SESS_RECOV;
3231                if (task->state == ISCSI_TASK_PENDING)
3232                        state = ISCSI_TASK_COMPLETED;
3233                iscsi_complete_task(task, state);
3234                spin_unlock_bh(&session->back_lock);
3235        }
3236}
3237
3238void iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
3239{
3240        struct iscsi_conn *conn = cls_conn->dd_data;
3241        struct iscsi_session *session = conn->session;
3242        int old_stop_stage;
3243
3244        mutex_lock(&session->eh_mutex);
3245        spin_lock_bh(&session->frwd_lock);
3246        if (conn->stop_stage == STOP_CONN_TERM) {
3247                spin_unlock_bh(&session->frwd_lock);
3248                mutex_unlock(&session->eh_mutex);
3249                return;
3250        }
3251
3252        /*
3253         * When this is called for the in_login state, we only want to clean
3254         * up the login task and connection. We do not need to block and set
3255         * the recovery state again
3256         */
3257        if (flag == STOP_CONN_TERM)
3258                session->state = ISCSI_STATE_TERMINATE;
3259        else if (conn->stop_stage != STOP_CONN_RECOVER)
3260                session->state = ISCSI_STATE_IN_RECOVERY;
3261
3262        old_stop_stage = conn->stop_stage;
3263        conn->stop_stage = flag;
3264        spin_unlock_bh(&session->frwd_lock);
3265
3266        del_timer_sync(&conn->transport_timer);
3267        iscsi_suspend_tx(conn);
3268
3269        spin_lock_bh(&session->frwd_lock);
3270        conn->c_stage = ISCSI_CONN_STOPPED;
3271        spin_unlock_bh(&session->frwd_lock);
3272
3273        /*
3274         * for connection level recovery we should not calculate
3275         * header digest. conn->hdr_size used for optimization
3276         * in hdr_extract() and will be re-negotiated at
3277         * set_param() time.
3278         */
3279        if (flag == STOP_CONN_RECOVER) {
3280                conn->hdrdgst_en = 0;
3281                conn->datadgst_en = 0;
3282                if (session->state == ISCSI_STATE_IN_RECOVERY &&
3283                    old_stop_stage != STOP_CONN_RECOVER) {
3284                        ISCSI_DBG_SESSION(session, "blocking session\n");
3285                        iscsi_block_session(session->cls_session);
3286                }
3287        }
3288
3289        /*
3290         * flush queues.
3291         */
3292        spin_lock_bh(&session->frwd_lock);
3293        fail_scsi_tasks(conn, -1, DID_TRANSPORT_DISRUPTED);
3294        fail_mgmt_tasks(session, conn);
3295        memset(&session->tmhdr, 0, sizeof(session->tmhdr));
3296        spin_unlock_bh(&session->frwd_lock);
3297        mutex_unlock(&session->eh_mutex);
3298}
3299EXPORT_SYMBOL_GPL(iscsi_conn_stop);
3300
3301int iscsi_conn_bind(struct iscsi_cls_session *cls_session,
3302                    struct iscsi_cls_conn *cls_conn, int is_leading)
3303{
3304        struct iscsi_session *session = cls_session->dd_data;
3305        struct iscsi_conn *conn = cls_conn->dd_data;
3306
3307        spin_lock_bh(&session->frwd_lock);
3308        if (is_leading)
3309                session->leadconn = conn;
3310        spin_unlock_bh(&session->frwd_lock);
3311
3312        /*
3313         * The target could have reduced it's window size between logins, so
3314         * we have to reset max/exp cmdsn so we can see the new values.
3315         */
3316        spin_lock_bh(&session->back_lock);
3317        session->max_cmdsn = session->exp_cmdsn = session->cmdsn + 1;
3318        spin_unlock_bh(&session->back_lock);
3319        /*
3320         * Unblock xmitworker(), Login Phase will pass through.
3321         */
3322        clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
3323        clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
3324        return 0;
3325}
3326EXPORT_SYMBOL_GPL(iscsi_conn_bind);
3327
3328int iscsi_switch_str_param(char **param, char *new_val_buf)
3329{
3330        char *new_val;
3331
3332        if (*param) {
3333                if (!strcmp(*param, new_val_buf))
3334                        return 0;
3335        }
3336
3337        new_val = kstrdup(new_val_buf, GFP_NOIO);
3338        if (!new_val)
3339                return -ENOMEM;
3340
3341        kfree(*param);
3342        *param = new_val;
3343        return 0;
3344}
3345EXPORT_SYMBOL_GPL(iscsi_switch_str_param);
3346
3347int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
3348                    enum iscsi_param param, char *buf, int buflen)
3349{
3350        struct iscsi_conn *conn = cls_conn->dd_data;
3351        struct iscsi_session *session = conn->session;
3352        int val;
3353
3354        switch(param) {
3355        case ISCSI_PARAM_FAST_ABORT:
3356                sscanf(buf, "%d", &session->fast_abort);
3357                break;
3358        case ISCSI_PARAM_ABORT_TMO:
3359                sscanf(buf, "%d", &session->abort_timeout);
3360                break;
3361        case ISCSI_PARAM_LU_RESET_TMO:
3362                sscanf(buf, "%d", &session->lu_reset_timeout);
3363                break;
3364        case ISCSI_PARAM_TGT_RESET_TMO:
3365                sscanf(buf, "%d", &session->tgt_reset_timeout);
3366                break;
3367        case ISCSI_PARAM_PING_TMO:
3368                sscanf(buf, "%d", &conn->ping_timeout);
3369                break;
3370        case ISCSI_PARAM_RECV_TMO:
3371                sscanf(buf, "%d", &conn->recv_timeout);
3372                break;
3373        case ISCSI_PARAM_MAX_RECV_DLENGTH:
3374                sscanf(buf, "%d", &conn->max_recv_dlength);
3375                break;
3376        case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3377                sscanf(buf, "%d", &conn->max_xmit_dlength);
3378                break;
3379        case ISCSI_PARAM_HDRDGST_EN:
3380                sscanf(buf, "%d", &conn->hdrdgst_en);
3381                break;
3382        case ISCSI_PARAM_DATADGST_EN:
3383                sscanf(buf, "%d", &conn->datadgst_en);
3384                break;
3385        case ISCSI_PARAM_INITIAL_R2T_EN:
3386                sscanf(buf, "%d", &session->initial_r2t_en);
3387                break;
3388        case ISCSI_PARAM_MAX_R2T:
3389                sscanf(buf, "%hu", &session->max_r2t);
3390                break;
3391        case ISCSI_PARAM_IMM_DATA_EN:
3392                sscanf(buf, "%d", &session->imm_data_en);
3393                break;
3394        case ISCSI_PARAM_FIRST_BURST:
3395                sscanf(buf, "%d", &session->first_burst);
3396                break;
3397        case ISCSI_PARAM_MAX_BURST:
3398                sscanf(buf, "%d", &session->max_burst);
3399                break;
3400        case ISCSI_PARAM_PDU_INORDER_EN:
3401                sscanf(buf, "%d", &session->pdu_inorder_en);
3402                break;
3403        case ISCSI_PARAM_DATASEQ_INORDER_EN:
3404                sscanf(buf, "%d", &session->dataseq_inorder_en);
3405                break;
3406        case ISCSI_PARAM_ERL:
3407                sscanf(buf, "%d", &session->erl);
3408                break;
3409        case ISCSI_PARAM_EXP_STATSN:
3410                sscanf(buf, "%u", &conn->exp_statsn);
3411                break;
3412        case ISCSI_PARAM_USERNAME:
3413                return iscsi_switch_str_param(&session->username, buf);
3414        case ISCSI_PARAM_USERNAME_IN:
3415                return iscsi_switch_str_param(&session->username_in, buf);
3416        case ISCSI_PARAM_PASSWORD:
3417                return iscsi_switch_str_param(&session->password, buf);
3418        case ISCSI_PARAM_PASSWORD_IN:
3419                return iscsi_switch_str_param(&session->password_in, buf);
3420        case ISCSI_PARAM_TARGET_NAME:
3421                return iscsi_switch_str_param(&session->targetname, buf);
3422        case ISCSI_PARAM_TARGET_ALIAS:
3423                return iscsi_switch_str_param(&session->targetalias, buf);
3424        case ISCSI_PARAM_TPGT:
3425                sscanf(buf, "%d", &session->tpgt);
3426                break;
3427        case ISCSI_PARAM_PERSISTENT_PORT:
3428                sscanf(buf, "%d", &conn->persistent_port);
3429                break;
3430        case ISCSI_PARAM_PERSISTENT_ADDRESS:
3431                return iscsi_switch_str_param(&conn->persistent_address, buf);
3432        case ISCSI_PARAM_IFACE_NAME:
3433                return iscsi_switch_str_param(&session->ifacename, buf);
3434        case ISCSI_PARAM_INITIATOR_NAME:
3435                return iscsi_switch_str_param(&session->initiatorname, buf);
3436        case ISCSI_PARAM_BOOT_ROOT:
3437                return iscsi_switch_str_param(&session->boot_root, buf);
3438        case ISCSI_PARAM_BOOT_NIC:
3439                return iscsi_switch_str_param(&session->boot_nic, buf);
3440        case ISCSI_PARAM_BOOT_TARGET:
3441                return iscsi_switch_str_param(&session->boot_target, buf);
3442        case ISCSI_PARAM_PORTAL_TYPE:
3443                return iscsi_switch_str_param(&session->portal_type, buf);
3444        case ISCSI_PARAM_DISCOVERY_PARENT_TYPE:
3445                return iscsi_switch_str_param(&session->discovery_parent_type,
3446                                              buf);
3447        case ISCSI_PARAM_DISCOVERY_SESS:
3448                sscanf(buf, "%d", &val);
3449                session->discovery_sess = !!val;
3450                break;
3451        case ISCSI_PARAM_LOCAL_IPADDR:
3452                return iscsi_switch_str_param(&conn->local_ipaddr, buf);
3453        default:
3454                return -ENOSYS;
3455        }
3456
3457        return 0;
3458}
3459EXPORT_SYMBOL_GPL(iscsi_set_param);
3460
3461int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
3462                            enum iscsi_param param, char *buf)
3463{
3464        struct iscsi_session *session = cls_session->dd_data;
3465        int len;
3466
3467        switch(param) {
3468        case ISCSI_PARAM_FAST_ABORT:
3469                len = sysfs_emit(buf, "%d\n", session->fast_abort);
3470                break;
3471        case ISCSI_PARAM_ABORT_TMO:
3472                len = sysfs_emit(buf, "%d\n", session->abort_timeout);
3473                break;
3474        case ISCSI_PARAM_LU_RESET_TMO:
3475                len = sysfs_emit(buf, "%d\n", session->lu_reset_timeout);
3476                break;
3477        case ISCSI_PARAM_TGT_RESET_TMO:
3478                len = sysfs_emit(buf, "%d\n", session->tgt_reset_timeout);
3479                break;
3480        case ISCSI_PARAM_INITIAL_R2T_EN:
3481                len = sysfs_emit(buf, "%d\n", session->initial_r2t_en);
3482                break;
3483        case ISCSI_PARAM_MAX_R2T:
3484                len = sysfs_emit(buf, "%hu\n", session->max_r2t);
3485                break;
3486        case ISCSI_PARAM_IMM_DATA_EN:
3487                len = sysfs_emit(buf, "%d\n", session->imm_data_en);
3488                break;
3489        case ISCSI_PARAM_FIRST_BURST:
3490                len = sysfs_emit(buf, "%u\n", session->first_burst);
3491                break;
3492        case ISCSI_PARAM_MAX_BURST:
3493                len = sysfs_emit(buf, "%u\n", session->max_burst);
3494                break;
3495        case ISCSI_PARAM_PDU_INORDER_EN:
3496                len = sysfs_emit(buf, "%d\n", session->pdu_inorder_en);
3497                break;
3498        case ISCSI_PARAM_DATASEQ_INORDER_EN:
3499                len = sysfs_emit(buf, "%d\n", session->dataseq_inorder_en);
3500                break;
3501        case ISCSI_PARAM_DEF_TASKMGMT_TMO:
3502                len = sysfs_emit(buf, "%d\n", session->def_taskmgmt_tmo);
3503                break;
3504        case ISCSI_PARAM_ERL:
3505                len = sysfs_emit(buf, "%d\n", session->erl);
3506                break;
3507        case ISCSI_PARAM_TARGET_NAME:
3508                len = sysfs_emit(buf, "%s\n", session->targetname);
3509                break;
3510        case ISCSI_PARAM_TARGET_ALIAS:
3511                len = sysfs_emit(buf, "%s\n", session->targetalias);
3512                break;
3513        case ISCSI_PARAM_TPGT:
3514                len = sysfs_emit(buf, "%d\n", session->tpgt);
3515                break;
3516        case ISCSI_PARAM_USERNAME:
3517                len = sysfs_emit(buf, "%s\n", session->username);
3518                break;
3519        case ISCSI_PARAM_USERNAME_IN:
3520                len = sysfs_emit(buf, "%s\n", session->username_in);
3521                break;
3522        case ISCSI_PARAM_PASSWORD:
3523                len = sysfs_emit(buf, "%s\n", session->password);
3524                break;
3525        case ISCSI_PARAM_PASSWORD_IN:
3526                len = sysfs_emit(buf, "%s\n", session->password_in);
3527                break;
3528        case ISCSI_PARAM_IFACE_NAME:
3529                len = sysfs_emit(buf, "%s\n", session->ifacename);
3530                break;
3531        case ISCSI_PARAM_INITIATOR_NAME:
3532                len = sysfs_emit(buf, "%s\n", session->initiatorname);
3533                break;
3534        case ISCSI_PARAM_BOOT_ROOT:
3535                len = sysfs_emit(buf, "%s\n", session->boot_root);
3536                break;
3537        case ISCSI_PARAM_BOOT_NIC:
3538                len = sysfs_emit(buf, "%s\n", session->boot_nic);
3539                break;
3540        case ISCSI_PARAM_BOOT_TARGET:
3541                len = sysfs_emit(buf, "%s\n", session->boot_target);
3542                break;
3543        case ISCSI_PARAM_AUTO_SND_TGT_DISABLE:
3544                len = sysfs_emit(buf, "%u\n", session->auto_snd_tgt_disable);
3545                break;
3546        case ISCSI_PARAM_DISCOVERY_SESS:
3547                len = sysfs_emit(buf, "%u\n", session->discovery_sess);
3548                break;
3549        case ISCSI_PARAM_PORTAL_TYPE:
3550                len = sysfs_emit(buf, "%s\n", session->portal_type);
3551                break;
3552        case ISCSI_PARAM_CHAP_AUTH_EN:
3553                len = sysfs_emit(buf, "%u\n", session->chap_auth_en);
3554                break;
3555        case ISCSI_PARAM_DISCOVERY_LOGOUT_EN:
3556                len = sysfs_emit(buf, "%u\n", session->discovery_logout_en);
3557                break;
3558        case ISCSI_PARAM_BIDI_CHAP_EN:
3559                len = sysfs_emit(buf, "%u\n", session->bidi_chap_en);
3560                break;
3561        case ISCSI_PARAM_DISCOVERY_AUTH_OPTIONAL:
3562                len = sysfs_emit(buf, "%u\n", session->discovery_auth_optional);
3563                break;
3564        case ISCSI_PARAM_DEF_TIME2WAIT:
3565                len = sysfs_emit(buf, "%d\n", session->time2wait);
3566                break;
3567        case ISCSI_PARAM_DEF_TIME2RETAIN:
3568                len = sysfs_emit(buf, "%d\n", session->time2retain);
3569                break;
3570        case ISCSI_PARAM_TSID:
3571                len = sysfs_emit(buf, "%u\n", session->tsid);
3572                break;
3573        case ISCSI_PARAM_ISID:
3574                len = sysfs_emit(buf, "%02x%02x%02x%02x%02x%02x\n",
3575                              session->isid[0], session->isid[1],
3576                              session->isid[2], session->isid[3],
3577                              session->isid[4], session->isid[5]);
3578                break;
3579        case ISCSI_PARAM_DISCOVERY_PARENT_IDX:
3580                len = sysfs_emit(buf, "%u\n", session->discovery_parent_idx);
3581                break;
3582        case ISCSI_PARAM_DISCOVERY_PARENT_TYPE:
3583                if (session->discovery_parent_type)
3584                        len = sysfs_emit(buf, "%s\n",
3585                                      session->discovery_parent_type);
3586                else
3587                        len = sysfs_emit(buf, "\n");
3588                break;
3589        default:
3590                return -ENOSYS;
3591        }
3592
3593        return len;
3594}
3595EXPORT_SYMBOL_GPL(iscsi_session_get_param);
3596
3597int iscsi_conn_get_addr_param(struct sockaddr_storage *addr,
3598                              enum iscsi_param param, char *buf)
3599{
3600        struct sockaddr_in6 *sin6 = NULL;
3601        struct sockaddr_in *sin = NULL;
3602        int len;
3603
3604        switch (addr->ss_family) {
3605        case AF_INET:
3606                sin = (struct sockaddr_in *)addr;
3607                break;
3608        case AF_INET6:
3609                sin6 = (struct sockaddr_in6 *)addr;
3610                break;
3611        default:
3612                return -EINVAL;
3613        }
3614
3615        switch (param) {
3616        case ISCSI_PARAM_CONN_ADDRESS:
3617        case ISCSI_HOST_PARAM_IPADDRESS:
3618                if (sin)
3619                        len = sysfs_emit(buf, "%pI4\n", &sin->sin_addr.s_addr);
3620                else
3621                        len = sysfs_emit(buf, "%pI6\n", &sin6->sin6_addr);
3622                break;
3623        case ISCSI_PARAM_CONN_PORT:
3624        case ISCSI_PARAM_LOCAL_PORT:
3625                if (sin)
3626                        len = sysfs_emit(buf, "%hu\n", be16_to_cpu(sin->sin_port));
3627                else
3628                        len = sysfs_emit(buf, "%hu\n",
3629                                      be16_to_cpu(sin6->sin6_port));
3630                break;
3631        default:
3632                return -EINVAL;
3633        }
3634
3635        return len;
3636}
3637EXPORT_SYMBOL_GPL(iscsi_conn_get_addr_param);
3638
3639int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
3640                         enum iscsi_param param, char *buf)
3641{
3642        struct iscsi_conn *conn = cls_conn->dd_data;
3643        int len;
3644
3645        switch(param) {
3646        case ISCSI_PARAM_PING_TMO:
3647                len = sysfs_emit(buf, "%u\n", conn->ping_timeout);
3648                break;
3649        case ISCSI_PARAM_RECV_TMO:
3650                len = sysfs_emit(buf, "%u\n", conn->recv_timeout);
3651                break;
3652        case ISCSI_PARAM_MAX_RECV_DLENGTH:
3653                len = sysfs_emit(buf, "%u\n", conn->max_recv_dlength);
3654                break;
3655        case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3656                len = sysfs_emit(buf, "%u\n", conn->max_xmit_dlength);
3657                break;
3658        case ISCSI_PARAM_HDRDGST_EN:
3659                len = sysfs_emit(buf, "%d\n", conn->hdrdgst_en);
3660                break;
3661        case ISCSI_PARAM_DATADGST_EN:
3662                len = sysfs_emit(buf, "%d\n", conn->datadgst_en);
3663                break;
3664        case ISCSI_PARAM_IFMARKER_EN:
3665                len = sysfs_emit(buf, "%d\n", conn->ifmarker_en);
3666                break;
3667        case ISCSI_PARAM_OFMARKER_EN:
3668                len = sysfs_emit(buf, "%d\n", conn->ofmarker_en);
3669                break;
3670        case ISCSI_PARAM_EXP_STATSN:
3671                len = sysfs_emit(buf, "%u\n", conn->exp_statsn);
3672                break;
3673        case ISCSI_PARAM_PERSISTENT_PORT:
3674                len = sysfs_emit(buf, "%d\n", conn->persistent_port);
3675                break;
3676        case ISCSI_PARAM_PERSISTENT_ADDRESS:
3677                len = sysfs_emit(buf, "%s\n", conn->persistent_address);
3678                break;
3679        case ISCSI_PARAM_STATSN:
3680                len = sysfs_emit(buf, "%u\n", conn->statsn);
3681                break;
3682        case ISCSI_PARAM_MAX_SEGMENT_SIZE:
3683                len = sysfs_emit(buf, "%u\n", conn->max_segment_size);
3684                break;
3685        case ISCSI_PARAM_KEEPALIVE_TMO:
3686                len = sysfs_emit(buf, "%u\n", conn->keepalive_tmo);
3687                break;
3688        case ISCSI_PARAM_LOCAL_PORT:
3689                len = sysfs_emit(buf, "%u\n", conn->local_port);
3690                break;
3691        case ISCSI_PARAM_TCP_TIMESTAMP_STAT:
3692                len = sysfs_emit(buf, "%u\n", conn->tcp_timestamp_stat);
3693                break;
3694        case ISCSI_PARAM_TCP_NAGLE_DISABLE:
3695                len = sysfs_emit(buf, "%u\n", conn->tcp_nagle_disable);
3696                break;
3697        case ISCSI_PARAM_TCP_WSF_DISABLE:
3698                len = sysfs_emit(buf, "%u\n", conn->tcp_wsf_disable);
3699                break;
3700        case ISCSI_PARAM_TCP_TIMER_SCALE:
3701                len = sysfs_emit(buf, "%u\n", conn->tcp_timer_scale);
3702                break;
3703        case ISCSI_PARAM_TCP_TIMESTAMP_EN:
3704                len = sysfs_emit(buf, "%u\n", conn->tcp_timestamp_en);
3705                break;
3706        case ISCSI_PARAM_IP_FRAGMENT_DISABLE:
3707                len = sysfs_emit(buf, "%u\n", conn->fragment_disable);
3708                break;
3709        case ISCSI_PARAM_IPV4_TOS:
3710                len = sysfs_emit(buf, "%u\n", conn->ipv4_tos);
3711                break;
3712        case ISCSI_PARAM_IPV6_TC:
3713                len = sysfs_emit(buf, "%u\n", conn->ipv6_traffic_class);
3714                break;
3715        case ISCSI_PARAM_IPV6_FLOW_LABEL:
3716                len = sysfs_emit(buf, "%u\n", conn->ipv6_flow_label);
3717                break;
3718        case ISCSI_PARAM_IS_FW_ASSIGNED_IPV6:
3719                len = sysfs_emit(buf, "%u\n", conn->is_fw_assigned_ipv6);
3720                break;
3721        case ISCSI_PARAM_TCP_XMIT_WSF:
3722                len = sysfs_emit(buf, "%u\n", conn->tcp_xmit_wsf);
3723                break;
3724        case ISCSI_PARAM_TCP_RECV_WSF:
3725                len = sysfs_emit(buf, "%u\n", conn->tcp_recv_wsf);
3726                break;
3727        case ISCSI_PARAM_LOCAL_IPADDR:
3728                len = sysfs_emit(buf, "%s\n", conn->local_ipaddr);
3729                break;
3730        default:
3731                return -ENOSYS;
3732        }
3733
3734        return len;
3735}
3736EXPORT_SYMBOL_GPL(iscsi_conn_get_param);
3737
3738int iscsi_host_get_param(struct Scsi_Host *shost, enum iscsi_host_param param,
3739                         char *buf)
3740{
3741        struct iscsi_host *ihost = shost_priv(shost);
3742        int len;
3743
3744        switch (param) {
3745        case ISCSI_HOST_PARAM_NETDEV_NAME:
3746                len = sysfs_emit(buf, "%s\n", ihost->netdev);
3747                break;
3748        case ISCSI_HOST_PARAM_HWADDRESS:
3749                len = sysfs_emit(buf, "%s\n", ihost->hwaddress);
3750                break;
3751        case ISCSI_HOST_PARAM_INITIATOR_NAME:
3752                len = sysfs_emit(buf, "%s\n", ihost->initiatorname);
3753                break;
3754        default:
3755                return -ENOSYS;
3756        }
3757
3758        return len;
3759}
3760EXPORT_SYMBOL_GPL(iscsi_host_get_param);
3761
3762int iscsi_host_set_param(struct Scsi_Host *shost, enum iscsi_host_param param,
3763                         char *buf, int buflen)
3764{
3765        struct iscsi_host *ihost = shost_priv(shost);
3766
3767        switch (param) {
3768        case ISCSI_HOST_PARAM_NETDEV_NAME:
3769                return iscsi_switch_str_param(&ihost->netdev, buf);
3770        case ISCSI_HOST_PARAM_HWADDRESS:
3771                return iscsi_switch_str_param(&ihost->hwaddress, buf);
3772        case ISCSI_HOST_PARAM_INITIATOR_NAME:
3773                return iscsi_switch_str_param(&ihost->initiatorname, buf);
3774        default:
3775                return -ENOSYS;
3776        }
3777
3778        return 0;
3779}
3780EXPORT_SYMBOL_GPL(iscsi_host_set_param);
3781
3782MODULE_AUTHOR("Mike Christie");
3783MODULE_DESCRIPTION("iSCSI library functions");
3784MODULE_LICENSE("GPL");
3785