drivers/scsi/libiscsi.c

   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
  32 static int iscsi_dbg_lib_conn;
  33 module_param_named(debug_libiscsi_conn, iscsi_dbg_lib_conn, int,
  34                    S_IRUGO | S_IWUSR);
  35 MODULE_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
  39 static int iscsi_dbg_lib_session;
  40 module_param_named(debug_libiscsi_session, iscsi_dbg_lib_session, int,
  41                    S_IRUGO | S_IWUSR);
  42 MODULE_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
  46 static int iscsi_dbg_lib_eh;
  47 module_param_named(debug_libiscsi_eh, iscsi_dbg_lib_eh, int,
  48                    S_IRUGO | S_IWUSR);
  49 MODULE_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
  86 inline 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 }
  94 EXPORT_SYMBOL_GPL(iscsi_conn_queue_work);
  95
  96 static 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
 115 void 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 }
 120 EXPORT_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  **/
 134 void 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 }
 162 EXPORT_SYMBOL_GPL(iscsi_prep_data_out_pdu);
 163
 164 static 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  */
 181 static 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  */
 231 static int iscsi_check_tmf_restrictions(struct iscsi_task *task, int opcode)
 232 {
 233         struct iscsi_conn *conn = task->conn;
 234         struct iscsi_tm *tmf = &conn->tmhdr;
 235         u64 hdr_lun;
 236
 237         if (conn->tmf_state == TMF_INITIAL)
 238                 return 0;
 239
 240         if ((tmf->opcode & ISCSI_OPCODE_MASK) != ISCSI_OP_SCSI_TMFUNC)
 241                 return 0;
 242
 243         switch (ISCSI_TM_FUNC_VALUE(tmf)) {
 244         case ISCSI_TM_FUNC_LOGICAL_UNIT_RESET:
 245                 /*
 246                  * Allow PDUs for unrelated LUNs
 247                  */
 248                 hdr_lun = scsilun_to_int(&tmf->lun);
 249                 if (hdr_lun != task->sc->device->lun)
 250                         return 0;
 251                 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_conn_printk(KERN_INFO, conn,
 258                                           "task [op %x itt "
 259                                           "0x%x/0x%x] "
 260                                           "rejected.\n",
 261                                           opcode, task->itt,
 262                                           task->hdr_itt);
 263                         return -EACCES;
 264                 }
 265                 /*
 266                  * And also all data-out PDUs in response to R2T
 267                  * if fast_abort is set.
 268                  */
 269                 if (conn->session->fast_abort) {
 270                         iscsi_conn_printk(KERN_INFO, conn,
 271                                           "task [op %x itt "
 272                                           "0x%x/0x%x] fast abort.\n",
 273                                           opcode, task->itt,
 274                                           task->hdr_itt);
 275                         return -EACCES;
 276                 }
 277                 break;
 278         case ISCSI_TM_FUNC_ABORT_TASK:
 279                 /*
 280                  * the caller has already checked if the task
 281                  * they want to abort was in the pending queue so if
 282                  * we are here the cmd pdu has gone out already, and
 283                  * we will only hit this for data-outs
 284                  */
 285                 if (opcode == ISCSI_OP_SCSI_DATA_OUT &&
 286                     task->hdr_itt == tmf->rtt) {
 287                         ISCSI_DBG_SESSION(conn->session,
 288                                           "Preventing task %x/%x from sending "
 289                                           "data-out due to abort task in "
 290                                           "progress\n", task->itt,
 291                                           task->hdr_itt);
 292                         return -EACCES;
 293                 }
 294                 break;
 295         }
 296
 297         return 0;
 298 }
 299
 300 /**
 301  * iscsi_prep_scsi_cmd_pdu - prep iscsi scsi cmd pdu
 302  * @task: iscsi task
 303  *
 304  * Prep basic iSCSI PDU fields for a scsi cmd pdu. The LLD should set
 305  * fields like dlength or final based on how much data it sends
 306  */
 307 static int iscsi_prep_scsi_cmd_pdu(struct iscsi_task *task)
 308 {
 309         struct iscsi_conn *conn = task->conn;
 310         struct iscsi_session *session = conn->session;
 311         struct scsi_cmnd *sc = task->sc;
 312         struct iscsi_scsi_req *hdr;
 313         unsigned hdrlength, cmd_len, transfer_length;
 314         itt_t itt;
 315         int rc;
 316
 317         rc = iscsi_check_tmf_restrictions(task, ISCSI_OP_SCSI_CMD);
 318         if (rc)
 319                 return rc;
 320
 321         if (conn->session->tt->alloc_pdu) {
 322                 rc = conn->session->tt->alloc_pdu(task, ISCSI_OP_SCSI_CMD);
 323                 if (rc)
 324                         return rc;
 325         }
 326         hdr = (struct iscsi_scsi_req *)task->hdr;
 327         itt = hdr->itt;
 328         memset(hdr, 0, sizeof(*hdr));
 329
 330         if (session->tt->parse_pdu_itt)
 331                 hdr->itt = task->hdr_itt = itt;
 332         else
 333                 hdr->itt = task->hdr_itt = build_itt(task->itt,
 334                                                      task->conn->session->age);
 335         task->hdr_len = 0;
 336         rc = iscsi_add_hdr(task, sizeof(*hdr));
 337         if (rc)
 338                 return rc;
 339         hdr->opcode = ISCSI_OP_SCSI_CMD;
 340         hdr->flags = ISCSI_ATTR_SIMPLE;
 341         int_to_scsilun(sc->device->lun, &hdr->lun);
 342         task->lun = hdr->lun;
 343         hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
 344         cmd_len = sc->cmd_len;
 345         if (cmd_len < ISCSI_CDB_SIZE)
 346                 memset(&hdr->cdb[cmd_len], 0, ISCSI_CDB_SIZE - cmd_len);
 347         else if (cmd_len > ISCSI_CDB_SIZE) {
 348                 rc = iscsi_prep_ecdb_ahs(task);
 349                 if (rc)
 350                         return rc;
 351                 cmd_len = ISCSI_CDB_SIZE;
 352         }
 353         memcpy(hdr->cdb, sc->cmnd, cmd_len);
 354
 355         task->imm_count = 0;
 356         if (scsi_get_prot_op(sc) != SCSI_PROT_NORMAL)
 357                 task->protected = true;
 358
 359         transfer_length = scsi_transfer_length(sc);
 360         hdr->data_length = cpu_to_be32(transfer_length);
 361         if (sc->sc_data_direction == DMA_TO_DEVICE) {
 362                 struct iscsi_r2t_info *r2t = &task->unsol_r2t;
 363
 364                 hdr->flags |= ISCSI_FLAG_CMD_WRITE;
 365                 /*
 366                  * Write counters:
 367                  *
 368                  *      imm_count       bytes to be sent right after
 369                  *                      SCSI PDU Header
 370                  *
 371                  *      unsol_count     bytes(as Data-Out) to be sent
 372                  *                      without R2T ack right after
 373                  *                      immediate data
 374                  *
 375                  *      r2t data_length bytes to be sent via R2T ack's
 376                  *
 377                  *      pad_count       bytes to be sent as zero-padding
 378                  */
 379                 memset(r2t, 0, sizeof(*r2t));
 380
 381                 if (session->imm_data_en) {
 382                         if (transfer_length >= session->first_burst)
 383                                 task->imm_count = min(session->first_burst,
 384                                                         conn->max_xmit_dlength);
 385                         else
 386                                 task->imm_count = min(transfer_length,
 387                                                       conn->max_xmit_dlength);
 388                         hton24(hdr->dlength, task->imm_count);
 389                 } else
 390                         zero_data(hdr->dlength);
 391
 392                 if (!session->initial_r2t_en) {
 393                         r2t->data_length = min(session->first_burst,
 394                                                transfer_length) -
 395                                                task->imm_count;
 396                         r2t->data_offset = task->imm_count;
 397                         r2t->ttt = cpu_to_be32(ISCSI_RESERVED_TAG);
 398                         r2t->exp_statsn = cpu_to_be32(conn->exp_statsn);
 399                 }
 400
 401                 if (!task->unsol_r2t.data_length)
 402                         /* No unsolicit Data-Out's */
 403                         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
 404         } else {
 405                 hdr->flags |= ISCSI_FLAG_CMD_FINAL;
 406                 zero_data(hdr->dlength);
 407
 408                 if (sc->sc_data_direction == DMA_FROM_DEVICE)
 409                         hdr->flags |= ISCSI_FLAG_CMD_READ;
 410         }
 411
 412         /* calculate size of additional header segments (AHSs) */
 413         hdrlength = task->hdr_len - sizeof(*hdr);
 414
 415         WARN_ON(hdrlength & (ISCSI_PAD_LEN-1));
 416         hdrlength /= ISCSI_PAD_LEN;
 417
 418         WARN_ON(hdrlength >= 256);
 419         hdr->hlength = hdrlength & 0xFF;
 420         hdr->cmdsn = task->cmdsn = cpu_to_be32(session->cmdsn);
 421
 422         if (session->tt->init_task && session->tt->init_task(task))
 423                 return -EIO;
 424
 425         task->state = ISCSI_TASK_RUNNING;
 426         session->cmdsn++;
 427
 428         conn->scsicmd_pdus_cnt++;
 429         ISCSI_DBG_SESSION(session, "iscsi prep [%s cid %d sc %p cdb 0x%x "
 430                           "itt 0x%x len %d cmdsn %d win %d]\n",
 431                           sc->sc_data_direction == DMA_TO_DEVICE ?
 432                           "write" : "read", conn->id, sc, sc->cmnd[0],
 433                           task->itt, transfer_length,
 434                           session->cmdsn,
 435                           session->max_cmdsn - session->exp_cmdsn + 1);
 436         return 0;
 437 }
 438
 439 /**
 440  * iscsi_free_task - free a task
 441  * @task: iscsi cmd task
 442  *
 443  * Must be called with session back_lock.
 444  * This function returns the scsi command to scsi-ml or cleans
 445  * up mgmt tasks then returns the task to the pool.
 446  */
 447 static void iscsi_free_task(struct iscsi_task *task)
 448 {
 449         struct iscsi_conn *conn = task->conn;
 450         struct iscsi_session *session = conn->session;
 451         struct scsi_cmnd *sc = task->sc;
 452         int oldstate = task->state;
 453
 454         ISCSI_DBG_SESSION(session, "freeing task itt 0x%x state %d sc %p\n",
 455                           task->itt, task->state, task->sc);
 456
 457         session->tt->cleanup_task(task);
 458         task->state = ISCSI_TASK_FREE;
 459         task->sc = NULL;
 460         /*
 461          * login task is preallocated so do not free
 462          */
 463         if (conn->login_task == task)
 464                 return;
 465
 466         kfifo_in(&session->cmdpool.queue, (void*)&task, sizeof(void*));
 467
 468         if (sc) {
 469                 /* SCSI eh reuses commands to verify us */
 470                 sc->SCp.ptr = NULL;
 471                 /*
 472                  * queue command may call this to free the task, so
 473                  * it will decide how to return sc to scsi-ml.
 474                  */
 475                 if (oldstate != ISCSI_TASK_REQUEUE_SCSIQ)
 476                         sc->scsi_done(sc);
 477         }
 478 }
 479
 480 void __iscsi_get_task(struct iscsi_task *task)
 481 {
 482         refcount_inc(&task->refcount);
 483 }
 484 EXPORT_SYMBOL_GPL(__iscsi_get_task);
 485
 486 void __iscsi_put_task(struct iscsi_task *task)
 487 {
 488         if (refcount_dec_and_test(&task->refcount))
 489                 iscsi_free_task(task);
 490 }
 491 EXPORT_SYMBOL_GPL(__iscsi_put_task);
 492
 493 void iscsi_put_task(struct iscsi_task *task)
 494 {
 495         struct iscsi_session *session = task->conn->session;
 496
 497         /* regular RX path uses back_lock */
 498         spin_lock_bh(&session->back_lock);
 499         __iscsi_put_task(task);
 500         spin_unlock_bh(&session->back_lock);
 501 }
 502 EXPORT_SYMBOL_GPL(iscsi_put_task);
 503
 504 /**
 505  * iscsi_complete_task - finish a task
 506  * @task: iscsi cmd task
 507  * @state: state to complete task with
 508  *
 509  * Must be called with session back_lock.
 510  */
 511 static void iscsi_complete_task(struct iscsi_task *task, int state)
 512 {
 513         struct iscsi_conn *conn = task->conn;
 514
 515         ISCSI_DBG_SESSION(conn->session,
 516                           "complete task itt 0x%x state %d sc %p\n",
 517                           task->itt, task->state, task->sc);
 518         if (task->state == ISCSI_TASK_COMPLETED ||
 519             task->state == ISCSI_TASK_ABRT_TMF ||
 520             task->state == ISCSI_TASK_ABRT_SESS_RECOV ||
 521             task->state == ISCSI_TASK_REQUEUE_SCSIQ)
 522                 return;
 523         WARN_ON_ONCE(task->state == ISCSI_TASK_FREE);
 524         task->state = state;
 525
 526         spin_lock_bh(&conn->taskqueuelock);
 527         if (!list_empty(&task->running)) {
 528                 pr_debug_once("%s while task on list", __func__);
 529                 list_del_init(&task->running);
 530         }
 531         spin_unlock_bh(&conn->taskqueuelock);
 532
 533         if (conn->task == task)
 534                 conn->task = NULL;
 535
 536         if (conn->ping_task == task)
 537                 conn->ping_task = NULL;
 538
 539         /* release get from queueing */
 540         __iscsi_put_task(task);
 541 }
 542
 543 /**
 544  * iscsi_complete_scsi_task - finish scsi task normally
 545  * @task: iscsi task for scsi cmd
 546  * @exp_cmdsn: expected cmd sn in cpu format
 547  * @max_cmdsn: max cmd sn in cpu format
 548  *
 549  * This is used when drivers do not need or cannot perform
 550  * lower level pdu processing.
 551  *
 552  * Called with session back_lock
 553  */
 554 void iscsi_complete_scsi_task(struct iscsi_task *task,
 555                               uint32_t exp_cmdsn, uint32_t max_cmdsn)
 556 {
 557         struct iscsi_conn *conn = task->conn;
 558
 559         ISCSI_DBG_SESSION(conn->session, "[itt 0x%x]\n", task->itt);
 560
 561         conn->last_recv = jiffies;
 562         __iscsi_update_cmdsn(conn->session, exp_cmdsn, max_cmdsn);
 563         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 564 }
 565 EXPORT_SYMBOL_GPL(iscsi_complete_scsi_task);
 566
 567
 568 /*
 569  * session back_lock must be held and if not called for a task that is
 570  * still pending or from the xmit thread, then xmit thread must
 571  * be suspended.
 572  */
 573 static void fail_scsi_task(struct iscsi_task *task, int err)
 574 {
 575         struct iscsi_conn *conn = task->conn;
 576         struct scsi_cmnd *sc;
 577         int state;
 578
 579         /*
 580          * if a command completes and we get a successful tmf response
 581          * we will hit this because the scsi eh abort code does not take
 582          * a ref to the task.
 583          */
 584         sc = task->sc;
 585         if (!sc)
 586                 return;
 587
 588         if (task->state == ISCSI_TASK_PENDING) {
 589                 /*
 590                  * cmd never made it to the xmit thread, so we should not count
 591                  * the cmd in the sequencing
 592                  */
 593                 conn->session->queued_cmdsn--;
 594                 /* it was never sent so just complete like normal */
 595                 state = ISCSI_TASK_COMPLETED;
 596         } else if (err == DID_TRANSPORT_DISRUPTED)
 597                 state = ISCSI_TASK_ABRT_SESS_RECOV;
 598         else
 599                 state = ISCSI_TASK_ABRT_TMF;
 600
 601         sc->result = err << 16;
 602         scsi_set_resid(sc, scsi_bufflen(sc));
 603
 604         /* regular RX path uses back_lock */
 605         spin_lock_bh(&conn->session->back_lock);
 606         iscsi_complete_task(task, state);
 607         spin_unlock_bh(&conn->session->back_lock);
 608 }
 609
 610 static int iscsi_prep_mgmt_task(struct iscsi_conn *conn,
 611                                 struct iscsi_task *task)
 612 {
 613         struct iscsi_session *session = conn->session;
 614         struct iscsi_hdr *hdr = task->hdr;
 615         struct iscsi_nopout *nop = (struct iscsi_nopout *)hdr;
 616         uint8_t opcode = hdr->opcode & ISCSI_OPCODE_MASK;
 617
 618         if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
 619                 return -ENOTCONN;
 620
 621         if (opcode != ISCSI_OP_LOGIN && opcode != ISCSI_OP_TEXT)
 622                 nop->exp_statsn = cpu_to_be32(conn->exp_statsn);
 623         /*
 624          * pre-format CmdSN for outgoing PDU.
 625          */
 626         nop->cmdsn = cpu_to_be32(session->cmdsn);
 627         if (hdr->itt != RESERVED_ITT) {
 628                 /*
 629                  * TODO: We always use immediate for normal session pdus.
 630                  * If we start to send tmfs or nops as non-immediate then
 631                  * we should start checking the cmdsn numbers for mgmt tasks.
 632                  *
 633                  * During discovery sessions iscsid sends TEXT as non immediate,
 634                  * but we always only send one PDU at a time.
 635                  */
 636                 if (conn->c_stage == ISCSI_CONN_STARTED &&
 637                     !(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
 638                         session->queued_cmdsn++;
 639                         session->cmdsn++;
 640                 }
 641         }
 642
 643         if (session->tt->init_task && session->tt->init_task(task))
 644                 return -EIO;
 645
 646         if ((hdr->opcode & ISCSI_OPCODE_MASK) == ISCSI_OP_LOGOUT)
 647                 session->state = ISCSI_STATE_LOGGING_OUT;
 648
 649         task->state = ISCSI_TASK_RUNNING;
 650         ISCSI_DBG_SESSION(session, "mgmtpdu [op 0x%x hdr->itt 0x%x "
 651                           "datalen %d]\n", hdr->opcode & ISCSI_OPCODE_MASK,
 652                           hdr->itt, task->data_count);
 653         return 0;
 654 }
 655
 656 static struct iscsi_task *
 657 __iscsi_conn_send_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 658                       char *data, uint32_t data_size)
 659 {
 660         struct iscsi_session *session = conn->session;
 661         struct iscsi_host *ihost = shost_priv(session->host);
 662         uint8_t opcode = hdr->opcode & ISCSI_OPCODE_MASK;
 663         struct iscsi_task *task;
 664         itt_t itt;
 665
 666         if (session->state == ISCSI_STATE_TERMINATE)
 667                 return NULL;
 668
 669         if (opcode == ISCSI_OP_LOGIN || opcode == ISCSI_OP_TEXT) {
 670                 /*
 671                  * Login and Text are sent serially, in
 672                  * request-followed-by-response sequence.
 673                  * Same task can be used. Same ITT must be used.
 674                  * Note that login_task is preallocated at conn_create().
 675                  */
 676                 if (conn->login_task->state != ISCSI_TASK_FREE) {
 677                         iscsi_conn_printk(KERN_ERR, conn, "Login/Text in "
 678                                           "progress. Cannot start new task.\n");
 679                         return NULL;
 680                 }
 681
 682                 if (data_size > ISCSI_DEF_MAX_RECV_SEG_LEN) {
 683                         iscsi_conn_printk(KERN_ERR, conn, "Invalid buffer len of %u for login task. Max len is %u\n", data_size, ISCSI_DEF_MAX_RECV_SEG_LEN);
 684                         return NULL;
 685                 }
 686
 687                 task = conn->login_task;
 688         } else {
 689                 if (session->state != ISCSI_STATE_LOGGED_IN)
 690                         return NULL;
 691
 692                 if (data_size != 0) {
 693                         iscsi_conn_printk(KERN_ERR, conn, "Can not send data buffer of len %u for op 0x%x\n", data_size, opcode);
 694                         return NULL;
 695                 }
 696
 697                 BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
 698                 BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);
 699
 700                 if (!kfifo_out(&session->cmdpool.queue,
 701                                  (void*)&task, sizeof(void*)))
 702                         return NULL;
 703         }
 704         /*
 705          * released in complete pdu for task we expect a response for, and
 706          * released by the lld when it has transmitted the task for
 707          * pdus we do not expect a response for.
 708          */
 709         refcount_set(&task->refcount, 1);
 710         task->conn = conn;
 711         task->sc = NULL;
 712         INIT_LIST_HEAD(&task->running);
 713         task->state = ISCSI_TASK_PENDING;
 714
 715         if (data_size) {
 716                 memcpy(task->data, data, data_size);
 717                 task->data_count = data_size;
 718         } else
 719                 task->data_count = 0;
 720
 721         if (conn->session->tt->alloc_pdu) {
 722                 if (conn->session->tt->alloc_pdu(task, hdr->opcode)) {
 723                         iscsi_conn_printk(KERN_ERR, conn, "Could not allocate "
 724                                          "pdu for mgmt task.\n");
 725                         goto free_task;
 726                 }
 727         }
 728
 729         itt = task->hdr->itt;
 730         task->hdr_len = sizeof(struct iscsi_hdr);
 731         memcpy(task->hdr, hdr, sizeof(struct iscsi_hdr));
 732
 733         if (hdr->itt != RESERVED_ITT) {
 734                 if (session->tt->parse_pdu_itt)
 735                         task->hdr->itt = itt;
 736                 else
 737                         task->hdr->itt = build_itt(task->itt,
 738                                                    task->conn->session->age);
 739         }
 740
 741         if (!ihost->workq) {
 742                 if (iscsi_prep_mgmt_task(conn, task))
 743                         goto free_task;
 744
 745                 if (session->tt->xmit_task(task))
 746                         goto free_task;
 747         } else {
 748                 spin_lock_bh(&conn->taskqueuelock);
 749                 list_add_tail(&task->running, &conn->mgmtqueue);
 750                 spin_unlock_bh(&conn->taskqueuelock);
 751                 iscsi_conn_queue_work(conn);
 752         }
 753
 754         return task;
 755
 756 free_task:
 757         /* regular RX path uses back_lock */
 758         spin_lock(&session->back_lock);
 759         __iscsi_put_task(task);
 760         spin_unlock(&session->back_lock);
 761         return NULL;
 762 }
 763
 764 int iscsi_conn_send_pdu(struct iscsi_cls_conn *cls_conn, struct iscsi_hdr *hdr,
 765                         char *data, uint32_t data_size)
 766 {
 767         struct iscsi_conn *conn = cls_conn->dd_data;
 768         struct iscsi_session *session = conn->session;
 769         int err = 0;
 770
 771         spin_lock_bh(&session->frwd_lock);
 772         if (!__iscsi_conn_send_pdu(conn, hdr, data, data_size))
 773                 err = -EPERM;
 774         spin_unlock_bh(&session->frwd_lock);
 775         return err;
 776 }
 777 EXPORT_SYMBOL_GPL(iscsi_conn_send_pdu);
 778
 779 /**
 780  * iscsi_cmd_rsp - SCSI Command Response processing
 781  * @conn: iscsi connection
 782  * @hdr: iscsi header
 783  * @task: scsi command task
 784  * @data: cmd data buffer
 785  * @datalen: len of buffer
 786  *
 787  * iscsi_cmd_rsp sets up the scsi_cmnd fields based on the PDU and
 788  * then completes the command and task. called under back_lock
 789  **/
 790 static void iscsi_scsi_cmd_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 791                                struct iscsi_task *task, char *data,
 792                                int datalen)
 793 {
 794         struct iscsi_scsi_rsp *rhdr = (struct iscsi_scsi_rsp *)hdr;
 795         struct iscsi_session *session = conn->session;
 796         struct scsi_cmnd *sc = task->sc;
 797
 798         iscsi_update_cmdsn(session, (struct iscsi_nopin*)rhdr);
 799         conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 800
 801         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 802
 803         if (task->protected) {
 804                 sector_t sector;
 805                 u8 ascq;
 806
 807                 /**
 808                  * Transports that didn't implement check_protection
 809                  * callback but still published T10-PI support to scsi-mid
 810                  * deserve this BUG_ON.
 811                  **/
 812                 BUG_ON(!session->tt->check_protection);
 813
 814                 ascq = session->tt->check_protection(task, &sector);
 815                 if (ascq) {
 816                         sc->result = DRIVER_SENSE << 24 |
 817                                      SAM_STAT_CHECK_CONDITION;
 818                         scsi_build_sense_buffer(1, sc->sense_buffer,
 819                                                 ILLEGAL_REQUEST, 0x10, ascq);
 820                         scsi_set_sense_information(sc->sense_buffer,
 821                                                    SCSI_SENSE_BUFFERSIZE,
 822                                                    sector);
 823                         goto out;
 824                 }
 825         }
 826
 827         if (rhdr->response != ISCSI_STATUS_CMD_COMPLETED) {
 828                 sc->result = DID_ERROR << 16;
 829                 goto out;
 830         }
 831
 832         if (rhdr->cmd_status == SAM_STAT_CHECK_CONDITION) {
 833                 uint16_t senselen;
 834
 835                 if (datalen < 2) {
 836 invalid_datalen:
 837                         iscsi_conn_printk(KERN_ERR,  conn,
 838                                          "Got CHECK_CONDITION but invalid data "
 839                                          "buffer size of %d\n", datalen);
 840                         sc->result = DID_BAD_TARGET << 16;
 841                         goto out;
 842                 }
 843
 844                 senselen = get_unaligned_be16(data);
 845                 if (datalen < senselen)
 846                         goto invalid_datalen;
 847
 848                 memcpy(sc->sense_buffer, data + 2,
 849                        min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
 850                 ISCSI_DBG_SESSION(session, "copied %d bytes of sense\n",
 851                                   min_t(uint16_t, senselen,
 852                                   SCSI_SENSE_BUFFERSIZE));
 853         }
 854
 855         if (rhdr->flags & (ISCSI_FLAG_CMD_BIDI_UNDERFLOW |
 856                            ISCSI_FLAG_CMD_BIDI_OVERFLOW)) {
 857                 sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 858         }
 859
 860         if (rhdr->flags & (ISCSI_FLAG_CMD_UNDERFLOW |
 861                            ISCSI_FLAG_CMD_OVERFLOW)) {
 862                 int res_count = be32_to_cpu(rhdr->residual_count);
 863
 864                 if (res_count > 0 &&
 865                     (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
 866                      res_count <= scsi_bufflen(sc)))
 867                         /* write side for bidi or uni-io set_resid */
 868                         scsi_set_resid(sc, res_count);
 869                 else
 870                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 871         }
 872 out:
 873         ISCSI_DBG_SESSION(session, "cmd rsp done [sc %p res %d itt 0x%x]\n",
 874                           sc, sc->result, task->itt);
 875         conn->scsirsp_pdus_cnt++;
 876         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 877 }
 878
 879 /**
 880  * iscsi_data_in_rsp - SCSI Data-In Response processing
 881  * @conn: iscsi connection
 882  * @hdr:  iscsi pdu
 883  * @task: scsi command task
 884  *
 885  * iscsi_data_in_rsp sets up the scsi_cmnd fields based on the data received
 886  * then completes the command and task. called under back_lock
 887  **/
 888 static void
 889 iscsi_data_in_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 890                   struct iscsi_task *task)
 891 {
 892         struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)hdr;
 893         struct scsi_cmnd *sc = task->sc;
 894
 895         if (!(rhdr->flags & ISCSI_FLAG_DATA_STATUS))
 896                 return;
 897
 898         iscsi_update_cmdsn(conn->session, (struct iscsi_nopin *)hdr);
 899         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 900         conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 901         if (rhdr->flags & (ISCSI_FLAG_DATA_UNDERFLOW |
 902                            ISCSI_FLAG_DATA_OVERFLOW)) {
 903                 int res_count = be32_to_cpu(rhdr->residual_count);
 904
 905                 if (res_count > 0 &&
 906                     (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
 907                      res_count <= sc->sdb.length))
 908                         scsi_set_resid(sc, res_count);
 909                 else
 910                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 911         }
 912
 913         ISCSI_DBG_SESSION(conn->session, "data in with status done "
 914                           "[sc %p res %d itt 0x%x]\n",
 915                           sc, sc->result, task->itt);
 916         conn->scsirsp_pdus_cnt++;
 917         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 918 }
 919
 920 static void iscsi_tmf_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
 921 {
 922         struct iscsi_tm_rsp *tmf = (struct iscsi_tm_rsp *)hdr;
 923
 924         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 925         conn->tmfrsp_pdus_cnt++;
 926
 927         if (conn->tmf_state != TMF_QUEUED)
 928                 return;
 929
 930         if (tmf->response == ISCSI_TMF_RSP_COMPLETE)
 931                 conn->tmf_state = TMF_SUCCESS;
 932         else if (tmf->response == ISCSI_TMF_RSP_NO_TASK)
 933                 conn->tmf_state = TMF_NOT_FOUND;
 934         else
 935                 conn->tmf_state = TMF_FAILED;
 936         wake_up(&conn->ehwait);
 937 }
 938
 939 static int iscsi_send_nopout(struct iscsi_conn *conn, struct iscsi_nopin *rhdr)
 940 {
 941         struct iscsi_nopout hdr;
 942         struct iscsi_task *task;
 943
 944         if (!rhdr && conn->ping_task)
 945                 return -EINVAL;
 946
 947         memset(&hdr, 0, sizeof(struct iscsi_nopout));
 948         hdr.opcode = ISCSI_OP_NOOP_OUT | ISCSI_OP_IMMEDIATE;
 949         hdr.flags = ISCSI_FLAG_CMD_FINAL;
 950
 951         if (rhdr) {
 952                 hdr.lun = rhdr->lun;
 953                 hdr.ttt = rhdr->ttt;
 954                 hdr.itt = RESERVED_ITT;
 955         } else
 956                 hdr.ttt = RESERVED_ITT;
 957
 958         task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)&hdr, NULL, 0);
 959         if (!task) {
 960                 iscsi_conn_printk(KERN_ERR, conn, "Could not send nopout\n");
 961                 return -EIO;
 962         } else if (!rhdr) {
 963                 /* only track our nops */
 964                 conn->ping_task = task;
 965                 conn->last_ping = jiffies;
 966         }
 967
 968         return 0;
 969 }
 970
 971 /**
 972  * iscsi_nop_out_rsp - SCSI NOP Response processing
 973  * @task: scsi command task
 974  * @nop: the nop structure
 975  * @data: where to put the data
 976  * @datalen: length of data
 977  *
 978  * iscsi_nop_out_rsp handles nop response from use or
 979  * from user space. called under back_lock
 980  **/
 981 static int iscsi_nop_out_rsp(struct iscsi_task *task,
 982                              struct iscsi_nopin *nop, char *data, int datalen)
 983 {
 984         struct iscsi_conn *conn = task->conn;
 985         int rc = 0;
 986
 987         if (conn->ping_task != task) {
 988                 /*
 989                  * If this is not in response to one of our
 990                  * nops then it must be from userspace.
 991                  */
 992                 if (iscsi_recv_pdu(conn->cls_conn, (struct iscsi_hdr *)nop,
 993                                    data, datalen))
 994                         rc = ISCSI_ERR_CONN_FAILED;
 995         } else
 996                 mod_timer(&conn->transport_timer, jiffies + conn->recv_timeout);
 997         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 998         return rc;
 999 }
1000
1001 static int iscsi_handle_reject(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1002                                char *data, int datalen)
1003 {
1004         struct iscsi_reject *reject = (struct iscsi_reject *)hdr;
1005         struct iscsi_hdr rejected_pdu;
1006         int opcode, rc = 0;
1007
1008         conn->exp_statsn = be32_to_cpu(reject->statsn) + 1;
1009
1010         if (ntoh24(reject->dlength) > datalen ||
1011             ntoh24(reject->dlength) < sizeof(struct iscsi_hdr)) {
1012                 iscsi_conn_printk(KERN_ERR, conn, "Cannot handle rejected "
1013                                   "pdu. Invalid data length (pdu dlength "
1014                                   "%u, datalen %d\n", ntoh24(reject->dlength),
1015                                   datalen);
1016                 return ISCSI_ERR_PROTO;
1017         }
1018         memcpy(&rejected_pdu, data, sizeof(struct iscsi_hdr));
1019         opcode = rejected_pdu.opcode & ISCSI_OPCODE_MASK;
1020
1021         switch (reject->reason) {
1022         case ISCSI_REASON_DATA_DIGEST_ERROR:
1023                 iscsi_conn_printk(KERN_ERR, conn,
1024                                   "pdu (op 0x%x itt 0x%x) rejected "
1025                                   "due to DataDigest error.\n",
1026                                   opcode, rejected_pdu.itt);
1027                 break;
1028         case ISCSI_REASON_IMM_CMD_REJECT:
1029                 iscsi_conn_printk(KERN_ERR, conn,
1030                                   "pdu (op 0x%x itt 0x%x) rejected. Too many "
1031                                   "immediate commands.\n",
1032                                   opcode, rejected_pdu.itt);
1033                 /*
1034                  * We only send one TMF at a time so if the target could not
1035                  * handle it, then it should get fixed (RFC mandates that
1036                  * a target can handle one immediate TMF per conn).
1037                  *
1038                  * For nops-outs, we could have sent more than one if
1039                  * the target is sending us lots of nop-ins
1040                  */
1041                 if (opcode != ISCSI_OP_NOOP_OUT)
1042                         return 0;
1043
1044                 if (rejected_pdu.itt == cpu_to_be32(ISCSI_RESERVED_TAG)) {
1045                         /*
1046                          * nop-out in response to target's nop-out rejected.
1047                          * Just resend.
1048                          */
1049                         /* In RX path we are under back lock */
1050                         spin_unlock(&conn->session->back_lock);
1051                         spin_lock(&conn->session->frwd_lock);
1052                         iscsi_send_nopout(conn,
1053                                           (struct iscsi_nopin*)&rejected_pdu);
1054                         spin_unlock(&conn->session->frwd_lock);
1055                         spin_lock(&conn->session->back_lock);
1056                 } else {
1057                         struct iscsi_task *task;
1058                         /*
1059                          * Our nop as ping got dropped. We know the target
1060                          * and transport are ok so just clean up
1061                          */
1062                         task = iscsi_itt_to_task(conn, rejected_pdu.itt);
1063                         if (!task) {
1064                                 iscsi_conn_printk(KERN_ERR, conn,
1065                                                  "Invalid pdu reject. Could "
1066                                                  "not lookup rejected task.\n");
1067                                 rc = ISCSI_ERR_BAD_ITT;
1068                         } else
1069                                 rc = iscsi_nop_out_rsp(task,
1070                                         (struct iscsi_nopin*)&rejected_pdu,
1071                                         NULL, 0);
1072                 }
1073                 break;
1074         default:
1075                 iscsi_conn_printk(KERN_ERR, conn,
1076                                   "pdu (op 0x%x itt 0x%x) rejected. Reason "
1077                                   "code 0x%x\n", rejected_pdu.opcode,
1078                                   rejected_pdu.itt, reject->reason);
1079                 break;
1080         }
1081         return rc;
1082 }
1083
1084 /**
1085  * iscsi_itt_to_task - look up task by itt
1086  * @conn: iscsi connection
1087  * @itt: itt
1088  *
1089  * This should be used for mgmt tasks like login and nops, or if
1090  * the LDD's itt space does not include the session age.
1091  *
1092  * The session back_lock must be held.
1093  */
1094 struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *conn, itt_t itt)
1095 {
1096         struct iscsi_session *session = conn->session;
1097         int i;
1098
1099         if (itt == RESERVED_ITT)
1100                 return NULL;
1101
1102         if (session->tt->parse_pdu_itt)
1103                 session->tt->parse_pdu_itt(conn, itt, &i, NULL);
1104         else
1105                 i = get_itt(itt);
1106         if (i >= session->cmds_max)
1107                 return NULL;
1108
1109         return session->cmds[i];
1110 }
1111 EXPORT_SYMBOL_GPL(iscsi_itt_to_task);
1112
1113 /**
1114  * __iscsi_complete_pdu - complete pdu
1115  * @conn: iscsi conn
1116  * @hdr: iscsi header
1117  * @data: data buffer
1118  * @datalen: len of data buffer
1119  *
1120  * Completes pdu processing by freeing any resources allocated at
1121  * queuecommand or send generic. session back_lock must be held and verify
1122  * itt must have been called.
1123  */
1124 int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1125                          char *data, int datalen)
1126 {
1127         struct iscsi_session *session = conn->session;
1128         int opcode = hdr->opcode & ISCSI_OPCODE_MASK, rc = 0;
1129         struct iscsi_task *task;
1130         uint32_t itt;
1131
1132         conn->last_recv = jiffies;
1133         rc = iscsi_verify_itt(conn, hdr->itt);
1134         if (rc)
1135                 return rc;
1136
1137         if (hdr->itt != RESERVED_ITT)
1138                 itt = get_itt(hdr->itt);
1139         else
1140                 itt = ~0U;
1141
1142         ISCSI_DBG_SESSION(session, "[op 0x%x cid %d itt 0x%x len %d]\n",
1143                           opcode, conn->id, itt, datalen);
1144
1145         if (itt == ~0U) {
1146                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1147
1148                 switch(opcode) {
1149                 case ISCSI_OP_NOOP_IN:
1150                         if (datalen) {
1151                                 rc = ISCSI_ERR_PROTO;
1152                                 break;
1153                         }
1154
1155                         if (hdr->ttt == cpu_to_be32(ISCSI_RESERVED_TAG))
1156                                 break;
1157
1158                         /* In RX path we are under back lock */
1159                         spin_unlock(&session->back_lock);
1160                         spin_lock(&session->frwd_lock);
1161                         iscsi_send_nopout(conn, (struct iscsi_nopin*)hdr);
1162                         spin_unlock(&session->frwd_lock);
1163                         spin_lock(&session->back_lock);
1164                         break;
1165                 case ISCSI_OP_REJECT:
1166                         rc = iscsi_handle_reject(conn, hdr, data, datalen);
1167                         break;
1168                 case ISCSI_OP_ASYNC_EVENT:
1169                         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1170                         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
1171                                 rc = ISCSI_ERR_CONN_FAILED;
1172                         break;
1173                 default:
1174                         rc = ISCSI_ERR_BAD_OPCODE;
1175                         break;
1176                 }
1177                 goto out;
1178         }
1179
1180         switch(opcode) {
1181         case ISCSI_OP_SCSI_CMD_RSP:
1182         case ISCSI_OP_SCSI_DATA_IN:
1183                 task = iscsi_itt_to_ctask(conn, hdr->itt);
1184                 if (!task)
1185                         return ISCSI_ERR_BAD_ITT;
1186                 task->last_xfer = jiffies;
1187                 break;
1188         case ISCSI_OP_R2T:
1189                 /*
1190                  * LLD handles R2Ts if they need to.
1191                  */
1192                 return 0;
1193         case ISCSI_OP_LOGOUT_RSP:
1194         case ISCSI_OP_LOGIN_RSP:
1195         case ISCSI_OP_TEXT_RSP:
1196         case ISCSI_OP_SCSI_TMFUNC_RSP:
1197         case ISCSI_OP_NOOP_IN:
1198                 task = iscsi_itt_to_task(conn, hdr->itt);
1199                 if (!task)
1200                         return ISCSI_ERR_BAD_ITT;
1201                 break;
1202         default:
1203                 return ISCSI_ERR_BAD_OPCODE;
1204         }
1205
1206         switch(opcode) {
1207         case ISCSI_OP_SCSI_CMD_RSP:
1208                 iscsi_scsi_cmd_rsp(conn, hdr, task, data, datalen);
1209                 break;
1210         case ISCSI_OP_SCSI_DATA_IN:
1211                 iscsi_data_in_rsp(conn, hdr, task);
1212                 break;
1213         case ISCSI_OP_LOGOUT_RSP:
1214                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1215                 if (datalen) {
1216                         rc = ISCSI_ERR_PROTO;
1217                         break;
1218                 }
1219                 conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1220                 goto recv_pdu;
1221         case ISCSI_OP_LOGIN_RSP:
1222         case ISCSI_OP_TEXT_RSP:
1223                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1224                 /*
1225                  * login related PDU's exp_statsn is handled in
1226                  * userspace
1227                  */
1228                 goto recv_pdu;
1229         case ISCSI_OP_SCSI_TMFUNC_RSP:
1230                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1231                 if (datalen) {
1232                         rc = ISCSI_ERR_PROTO;
1233                         break;
1234                 }
1235
1236                 iscsi_tmf_rsp(conn, hdr);
1237                 iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1238                 break;
1239         case ISCSI_OP_NOOP_IN:
1240                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1241                 if (hdr->ttt != cpu_to_be32(ISCSI_RESERVED_TAG) || datalen) {
1242                         rc = ISCSI_ERR_PROTO;
1243                         break;
1244                 }
1245                 conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1246
1247                 rc = iscsi_nop_out_rsp(task, (struct iscsi_nopin*)hdr,
1248                                        data, datalen);
1249                 break;
1250         default:
1251                 rc = ISCSI_ERR_BAD_OPCODE;
1252                 break;
1253         }
1254
1255 out:
1256         return rc;
1257 recv_pdu:
1258         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
1259                 rc = ISCSI_ERR_CONN_FAILED;
1260         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1261         return rc;
1262 }
1263 EXPORT_SYMBOL_GPL(__iscsi_complete_pdu);
1264
1265 int iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1266                        char *data, int datalen)
1267 {
1268         int rc;
1269
1270         spin_lock(&conn->session->back_lock);
1271         rc = __iscsi_complete_pdu(conn, hdr, data, datalen);
1272         spin_unlock(&conn->session->back_lock);
1273         return rc;
1274 }
1275 EXPORT_SYMBOL_GPL(iscsi_complete_pdu);
1276
1277 int iscsi_verify_itt(struct iscsi_conn *conn, itt_t itt)
1278 {
1279         struct iscsi_session *session = conn->session;
1280         int age = 0, i = 0;
1281
1282         if (itt == RESERVED_ITT)
1283                 return 0;
1284
1285         if (session->tt->parse_pdu_itt)
1286                 session->tt->parse_pdu_itt(conn, itt, &i, &age);
1287         else {
1288                 i = get_itt(itt);
1289                 age = ((__force u32)itt >> ISCSI_AGE_SHIFT) & ISCSI_AGE_MASK;
1290         }
1291
1292         if (age != session->age) {
1293                 iscsi_conn_printk(KERN_ERR, conn,
1294                                   "received itt %x expected session age (%x)\n",
1295                                   (__force u32)itt, session->age);
1296                 return ISCSI_ERR_BAD_ITT;
1297         }
1298
1299         if (i >= session->cmds_max) {
1300                 iscsi_conn_printk(KERN_ERR, conn,
1301                                   "received invalid itt index %u (max cmds "
1302                                    "%u.\n", i, session->cmds_max);
1303                 return ISCSI_ERR_BAD_ITT;
1304         }
1305         return 0;
1306 }
1307 EXPORT_SYMBOL_GPL(iscsi_verify_itt);
1308
1309 /**
1310  * iscsi_itt_to_ctask - look up ctask by itt
1311  * @conn: iscsi connection
1312  * @itt: itt
1313  *
1314  * This should be used for cmd tasks.
1315  *
1316  * The session back_lock must be held.
1317  */
1318 struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *conn, itt_t itt)
1319 {
1320         struct iscsi_task *task;
1321
1322         if (iscsi_verify_itt(conn, itt))
1323                 return NULL;
1324
1325         task = iscsi_itt_to_task(conn, itt);
1326         if (!task || !task->sc)
1327                 return NULL;
1328
1329         if (task->sc->SCp.phase != conn->session->age) {
1330                 iscsi_session_printk(KERN_ERR, conn->session,
1331                                   "task's session age %d, expected %d\n",
1332                                   task->sc->SCp.phase, conn->session->age);
1333                 return NULL;
1334         }
1335
1336         return task;
1337 }
1338 EXPORT_SYMBOL_GPL(iscsi_itt_to_ctask);
1339
1340 void iscsi_session_failure(struct iscsi_session *session,
1341                            enum iscsi_err err)
1342 {
1343         struct iscsi_conn *conn;
1344         struct device *dev;
1345
1346         spin_lock_bh(&session->frwd_lock);
1347         conn = session->leadconn;
1348         if (session->state == ISCSI_STATE_TERMINATE || !conn) {
1349                 spin_unlock_bh(&session->frwd_lock);
1350                 return;
1351         }
1352
1353         dev = get_device(&conn->cls_conn->dev);
1354         spin_unlock_bh(&session->frwd_lock);
1355         if (!dev)
1356                 return;
1357         /*
1358          * if the host is being removed bypass the connection
1359          * recovery initialization because we are going to kill
1360          * the session.
1361          */
1362         if (err == ISCSI_ERR_INVALID_HOST)
1363                 iscsi_conn_error_event(conn->cls_conn, err);
1364         else
1365                 iscsi_conn_failure(conn, err);
1366         put_device(dev);
1367 }
1368 EXPORT_SYMBOL_GPL(iscsi_session_failure);
1369
1370 void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err)
1371 {
1372         struct iscsi_session *session = conn->session;
1373
1374         spin_lock_bh(&session->frwd_lock);
1375         if (session->state == ISCSI_STATE_FAILED) {
1376                 spin_unlock_bh(&session->frwd_lock);
1377                 return;
1378         }
1379
1380         if (conn->stop_stage == 0)
1381                 session->state = ISCSI_STATE_FAILED;
1382         spin_unlock_bh(&session->frwd_lock);
1383
1384         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1385         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
1386         iscsi_conn_error_event(conn->cls_conn, err);
1387 }
1388 EXPORT_SYMBOL_GPL(iscsi_conn_failure);
1389
1390 static int iscsi_check_cmdsn_window_closed(struct iscsi_conn *conn)
1391 {
1392         struct iscsi_session *session = conn->session;
1393
1394         /*
1395          * Check for iSCSI window and take care of CmdSN wrap-around
1396          */
1397         if (!iscsi_sna_lte(session->queued_cmdsn, session->max_cmdsn)) {
1398                 ISCSI_DBG_SESSION(session, "iSCSI CmdSN closed. ExpCmdSn "
1399                                   "%u MaxCmdSN %u CmdSN %u/%u\n",
1400                                   session->exp_cmdsn, session->max_cmdsn,
1401                                   session->cmdsn, session->queued_cmdsn);
1402                 return -ENOSPC;
1403         }
1404         return 0;
1405 }
1406
1407 static int iscsi_xmit_task(struct iscsi_conn *conn)
1408 {
1409         struct iscsi_task *task = conn->task;
1410         int rc;
1411
1412         if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx))
1413                 return -ENODATA;
1414
1415         spin_lock_bh(&conn->session->back_lock);
1416         if (conn->task == NULL) {
1417                 spin_unlock_bh(&conn->session->back_lock);
1418                 return -ENODATA;
1419         }
1420         __iscsi_get_task(task);
1421         spin_unlock_bh(&conn->session->back_lock);
1422         spin_unlock_bh(&conn->session->frwd_lock);
1423         rc = conn->session->tt->xmit_task(task);
1424         spin_lock_bh(&conn->session->frwd_lock);
1425         if (!rc) {
1426                 /* done with this task */
1427                 task->last_xfer = jiffies;
1428                 conn->task = NULL;
1429         }
1430         /* regular RX path uses back_lock */
1431         spin_lock(&conn->session->back_lock);
1432         __iscsi_put_task(task);
1433         spin_unlock(&conn->session->back_lock);
1434         return rc;
1435 }
1436
1437 /**
1438  * iscsi_requeue_task - requeue task to run from session workqueue
1439  * @task: task to requeue
1440  *
1441  * LLDs that need to run a task from the session workqueue should call
1442  * this. The session frwd_lock must be held. This should only be called
1443  * by software drivers.
1444  */
1445 void iscsi_requeue_task(struct iscsi_task *task)
1446 {
1447         struct iscsi_conn *conn = task->conn;
1448
1449         /*
1450          * this may be on the requeue list already if the xmit_task callout
1451          * is handling the r2ts while we are adding new ones
1452          */
1453         spin_lock_bh(&conn->taskqueuelock);
1454         if (list_empty(&task->running))
1455                 list_add_tail(&task->running, &conn->requeue);
1456         spin_unlock_bh(&conn->taskqueuelock);
1457         iscsi_conn_queue_work(conn);
1458 }
1459 EXPORT_SYMBOL_GPL(iscsi_requeue_task);
1460
1461 /**
1462  * iscsi_data_xmit - xmit any command into the scheduled connection
1463  * @conn: iscsi connection
1464  *
1465  * Notes:
1466  *      The function can return -EAGAIN in which case the caller must
1467  *      re-schedule it again later or recover. '0' return code means
1468  *      successful xmit.
1469  **/
1470 static int iscsi_data_xmit(struct iscsi_conn *conn)
1471 {
1472         struct iscsi_task *task;
1473         int rc = 0;
1474
1475         spin_lock_bh(&conn->session->frwd_lock);
1476         if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx)) {
1477                 ISCSI_DBG_SESSION(conn->session, "Tx suspended!\n");
1478                 spin_unlock_bh(&conn->session->frwd_lock);
1479                 return -ENODATA;
1480         }
1481
1482         if (conn->task) {
1483                 rc = iscsi_xmit_task(conn);
1484                 if (rc)
1485                         goto done;
1486         }
1487
1488         /*
1489          * process mgmt pdus like nops before commands since we should
1490          * only have one nop-out as a ping from us and targets should not
1491          * overflow us with nop-ins
1492          */
1493         spin_lock_bh(&conn->taskqueuelock);
1494 check_mgmt:
1495         while (!list_empty(&conn->mgmtqueue)) {
1496                 conn->task = list_entry(conn->mgmtqueue.next,
1497                                          struct iscsi_task, running);
1498                 list_del_init(&conn->task->running);
1499                 spin_unlock_bh(&conn->taskqueuelock);
1500                 if (iscsi_prep_mgmt_task(conn, conn->task)) {
1501                         /* regular RX path uses back_lock */
1502                         spin_lock_bh(&conn->session->back_lock);
1503                         __iscsi_put_task(conn->task);
1504                         spin_unlock_bh(&conn->session->back_lock);
1505                         conn->task = NULL;
1506                         spin_lock_bh(&conn->taskqueuelock);
1507                         continue;
1508                 }
1509                 rc = iscsi_xmit_task(conn);
1510                 if (rc)
1511                         goto done;
1512                 spin_lock_bh(&conn->taskqueuelock);
1513         }
1514
1515         /* process pending command queue */
1516         while (!list_empty(&conn->cmdqueue)) {
1517                 conn->task = list_entry(conn->cmdqueue.next, struct iscsi_task,
1518                                         running);
1519                 list_del_init(&conn->task->running);
1520                 spin_unlock_bh(&conn->taskqueuelock);
1521                 if (conn->session->state == ISCSI_STATE_LOGGING_OUT) {
1522                         fail_scsi_task(conn->task, DID_IMM_RETRY);
1523                         spin_lock_bh(&conn->taskqueuelock);
1524                         continue;
1525                 }
1526                 rc = iscsi_prep_scsi_cmd_pdu(conn->task);
1527                 if (rc) {
1528                         if (rc == -ENOMEM || rc == -EACCES) {
1529                                 spin_lock_bh(&conn->taskqueuelock);
1530                                 list_add_tail(&conn->task->running,
1531                                               &conn->cmdqueue);
1532                                 conn->task = NULL;
1533                                 spin_unlock_bh(&conn->taskqueuelock);
1534                                 goto done;
1535                         } else
1536                                 fail_scsi_task(conn->task, DID_ABORT);
1537                         spin_lock_bh(&conn->taskqueuelock);
1538                         continue;
1539                 }
1540                 rc = iscsi_xmit_task(conn);
1541                 if (rc)
1542                         goto done;
1543                 /*
1544                  * we could continuously get new task requests so
1545                  * we need to check the mgmt queue for nops that need to
1546                  * be sent to aviod starvation
1547                  */
1548                 spin_lock_bh(&conn->taskqueuelock);
1549                 if (!list_empty(&conn->mgmtqueue))
1550                         goto check_mgmt;
1551         }
1552
1553         while (!list_empty(&conn->requeue)) {
1554                 /*
1555                  * we always do fastlogout - conn stop code will clean up.
1556                  */
1557                 if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
1558                         break;
1559
1560                 task = list_entry(conn->requeue.next, struct iscsi_task,
1561                                   running);
1562                 if (iscsi_check_tmf_restrictions(task, ISCSI_OP_SCSI_DATA_OUT))
1563                         break;
1564
1565                 conn->task = task;
1566                 list_del_init(&conn->task->running);
1567                 conn->task->state = ISCSI_TASK_RUNNING;
1568                 spin_unlock_bh(&conn->taskqueuelock);
1569                 rc = iscsi_xmit_task(conn);
1570                 if (rc)
1571                         goto done;
1572                 spin_lock_bh(&conn->taskqueuelock);
1573                 if (!list_empty(&conn->mgmtqueue))
1574                         goto check_mgmt;
1575         }
1576         spin_unlock_bh(&conn->taskqueuelock);
1577         spin_unlock_bh(&conn->session->frwd_lock);
1578         return -ENODATA;
1579
1580 done:
1581         spin_unlock_bh(&conn->session->frwd_lock);
1582         return rc;
1583 }
1584
1585 static void iscsi_xmitworker(struct work_struct *work)
1586 {
1587         struct iscsi_conn *conn =
1588                 container_of(work, struct iscsi_conn, xmitwork);
1589         int rc;
1590         /*
1591          * serialize Xmit worker on a per-connection basis.
1592          */
1593         do {
1594                 rc = iscsi_data_xmit(conn);
1595         } while (rc >= 0 || rc == -EAGAIN);
1596 }
1597
1598 static inline struct iscsi_task *iscsi_alloc_task(struct iscsi_conn *conn,
1599                                                   struct scsi_cmnd *sc)
1600 {
1601         struct iscsi_task *task;
1602
1603         if (!kfifo_out(&conn->session->cmdpool.queue,
1604                          (void *) &task, sizeof(void *)))
1605                 return NULL;
1606
1607         sc->SCp.phase = conn->session->age;
1608         sc->SCp.ptr = (char *) task;
1609
1610         refcount_set(&task->refcount, 1);
1611         task->state = ISCSI_TASK_PENDING;
1612         task->conn = conn;
1613         task->sc = sc;
1614         task->have_checked_conn = false;
1615         task->last_timeout = jiffies;
1616         task->last_xfer = jiffies;
1617         task->protected = false;
1618         INIT_LIST_HEAD(&task->running);
1619         return task;
1620 }
1621
1622 enum {
1623         FAILURE_BAD_HOST = 1,
1624         FAILURE_SESSION_FAILED,
1625         FAILURE_SESSION_FREED,
1626         FAILURE_WINDOW_CLOSED,
1627         FAILURE_OOM,
1628         FAILURE_SESSION_TERMINATE,
1629         FAILURE_SESSION_IN_RECOVERY,
1630         FAILURE_SESSION_RECOVERY_TIMEOUT,
1631         FAILURE_SESSION_LOGGING_OUT,
1632         FAILURE_SESSION_NOT_READY,
1633 };
1634
1635 int iscsi_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *sc)
1636 {
1637         struct iscsi_cls_session *cls_session;
1638         struct iscsi_host *ihost;
1639         int reason = 0;
1640         struct iscsi_session *session;
1641         struct iscsi_conn *conn;
1642         struct iscsi_task *task = NULL;
1643
1644         sc->result = 0;
1645         sc->SCp.ptr = NULL;
1646
1647         ihost = shost_priv(host);
1648
1649         cls_session = starget_to_session(scsi_target(sc->device));
1650         session = cls_session->dd_data;
1651         spin_lock_bh(&session->frwd_lock);
1652
1653         reason = iscsi_session_chkready(cls_session);
1654         if (reason) {
1655                 sc->result = reason;
1656                 goto fault;
1657         }
1658
1659         if (session->state != ISCSI_STATE_LOGGED_IN) {
1660                 /*
1661                  * to handle the race between when we set the recovery state
1662                  * and block the session we requeue here (commands could
1663                  * be entering our queuecommand while a block is starting
1664                  * up because the block code is not locked)
1665                  */
1666                 switch (session->state) {
1667                 case ISCSI_STATE_FAILED:
1668                         /*
1669                          * cmds should fail during shutdown, if the session
1670                          * state is bad, allowing completion to happen
1671                          */
1672                         if (unlikely(system_state != SYSTEM_RUNNING)) {
1673                                 reason = FAILURE_SESSION_FAILED;
1674                                 sc->result = DID_NO_CONNECT << 16;
1675                                 break;
1676                         }
1677                         fallthrough;
1678                 case ISCSI_STATE_IN_RECOVERY:
1679                         reason = FAILURE_SESSION_IN_RECOVERY;
1680                         sc->result = DID_IMM_RETRY << 16;
1681                         break;
1682                 case ISCSI_STATE_LOGGING_OUT:
1683                         reason = FAILURE_SESSION_LOGGING_OUT;
1684                         sc->result = DID_IMM_RETRY << 16;
1685                         break;
1686                 case ISCSI_STATE_RECOVERY_FAILED:
1687                         reason = FAILURE_SESSION_RECOVERY_TIMEOUT;
1688                         sc->result = DID_TRANSPORT_FAILFAST << 16;
1689                         break;
1690                 case ISCSI_STATE_TERMINATE:
1691                         reason = FAILURE_SESSION_TERMINATE;
1692                         sc->result = DID_NO_CONNECT << 16;
1693                         break;
1694                 default:
1695                         reason = FAILURE_SESSION_FREED;
1696                         sc->result = DID_NO_CONNECT << 16;
1697                 }
1698                 goto fault;
1699         }
1700
1701         conn = session->leadconn;
1702         if (!conn) {
1703                 reason = FAILURE_SESSION_FREED;
1704                 sc->result = DID_NO_CONNECT << 16;
1705                 goto fault;
1706         }
1707
1708         if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx)) {
1709                 reason = FAILURE_SESSION_IN_RECOVERY;
1710                 sc->result = DID_REQUEUE << 16;
1711                 goto fault;
1712         }
1713
1714         if (iscsi_check_cmdsn_window_closed(conn)) {
1715                 reason = FAILURE_WINDOW_CLOSED;
1716                 goto reject;
1717         }
1718
1719         task = iscsi_alloc_task(conn, sc);
1720         if (!task) {
1721                 reason = FAILURE_OOM;
1722                 goto reject;
1723         }
1724
1725         if (!ihost->workq) {
1726                 reason = iscsi_prep_scsi_cmd_pdu(task);
1727                 if (reason) {
1728                         if (reason == -ENOMEM ||  reason == -EACCES) {
1729                                 reason = FAILURE_OOM;
1730                                 goto prepd_reject;
1731                         } else {
1732                                 sc->result = DID_ABORT << 16;
1733                                 goto prepd_fault;
1734                         }
1735                 }
1736                 if (session->tt->xmit_task(task)) {
1737                         session->cmdsn--;
1738                         reason = FAILURE_SESSION_NOT_READY;
1739                         goto prepd_reject;
1740                 }
1741         } else {
1742                 spin_lock_bh(&conn->taskqueuelock);
1743                 list_add_tail(&task->running, &conn->cmdqueue);
1744                 spin_unlock_bh(&conn->taskqueuelock);
1745                 iscsi_conn_queue_work(conn);
1746         }
1747
1748         session->queued_cmdsn++;
1749         spin_unlock_bh(&session->frwd_lock);
1750         return 0;
1751
1752 prepd_reject:
1753         spin_lock_bh(&session->back_lock);
1754         iscsi_complete_task(task, ISCSI_TASK_REQUEUE_SCSIQ);
1755         spin_unlock_bh(&session->back_lock);
1756 reject:
1757         spin_unlock_bh(&session->frwd_lock);
1758         ISCSI_DBG_SESSION(session, "cmd 0x%x rejected (%d)\n",
1759                           sc->cmnd[0], reason);
1760         return SCSI_MLQUEUE_TARGET_BUSY;
1761
1762 prepd_fault:
1763         spin_lock_bh(&session->back_lock);
1764         iscsi_complete_task(task, ISCSI_TASK_REQUEUE_SCSIQ);
1765         spin_unlock_bh(&session->back_lock);
1766 fault:
1767         spin_unlock_bh(&session->frwd_lock);
1768         ISCSI_DBG_SESSION(session, "iscsi: cmd 0x%x is not queued (%d)\n",
1769                           sc->cmnd[0], reason);
1770         scsi_set_resid(sc, scsi_bufflen(sc));
1771         sc->scsi_done(sc);
1772         return 0;
1773 }
1774 EXPORT_SYMBOL_GPL(iscsi_queuecommand);
1775
1776 int iscsi_target_alloc(struct scsi_target *starget)
1777 {
1778         struct iscsi_cls_session *cls_session = starget_to_session(starget);
1779         struct iscsi_session *session = cls_session->dd_data;
1780
1781         starget->can_queue = session->scsi_cmds_max;
1782         return 0;
1783 }
1784 EXPORT_SYMBOL_GPL(iscsi_target_alloc);
1785
1786 static void iscsi_tmf_timedout(struct timer_list *t)
1787 {
1788         struct iscsi_conn *conn = from_timer(conn, t, tmf_timer);
1789         struct iscsi_session *session = conn->session;
1790
1791         spin_lock(&session->frwd_lock);
1792         if (conn->tmf_state == TMF_QUEUED) {
1793                 conn->tmf_state = TMF_TIMEDOUT;
1794                 ISCSI_DBG_EH(session, "tmf timedout\n");
1795                 /* unblock eh_abort() */
1796                 wake_up(&conn->ehwait);
1797         }
1798         spin_unlock(&session->frwd_lock);
1799 }
1800
1801 static int iscsi_exec_task_mgmt_fn(struct iscsi_conn *conn,
1802                                    struct iscsi_tm *hdr, int age,
1803                                    int timeout)
1804         __must_hold(&session->frwd_lock)
1805 {
1806         struct iscsi_session *session = conn->session;
1807         struct iscsi_task *task;
1808
1809         task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)hdr,
1810                                       NULL, 0);
1811         if (!task) {
1812                 spin_unlock_bh(&session->frwd_lock);
1813                 iscsi_conn_printk(KERN_ERR, conn, "Could not send TMF.\n");
1814                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1815                 spin_lock_bh(&session->frwd_lock);
1816                 return -EPERM;
1817         }
1818         conn->tmfcmd_pdus_cnt++;
1819         conn->tmf_timer.expires = timeout * HZ + jiffies;
1820         add_timer(&conn->tmf_timer);
1821         ISCSI_DBG_EH(session, "tmf set timeout\n");
1822
1823         spin_unlock_bh(&session->frwd_lock);
1824         mutex_unlock(&session->eh_mutex);
1825
1826         /*
1827          * block eh thread until:
1828          *
1829          * 1) tmf response
1830          * 2) tmf timeout
1831          * 3) session is terminated or restarted or userspace has
1832          * given up on recovery
1833          */
1834         wait_event_interruptible(conn->ehwait, age != session->age ||
1835                                  session->state != ISCSI_STATE_LOGGED_IN ||
1836                                  conn->tmf_state != TMF_QUEUED);
1837         if (signal_pending(current))
1838                 flush_signals(current);
1839         del_timer_sync(&conn->tmf_timer);
1840
1841         mutex_lock(&session->eh_mutex);
1842         spin_lock_bh(&session->frwd_lock);
1843         /* if the session drops it will clean up the task */
1844         if (age != session->age ||
1845             session->state != ISCSI_STATE_LOGGED_IN)
1846                 return -ENOTCONN;
1847         return 0;
1848 }
1849
1850 /*
1851  * Fail commands. session lock held and recv side suspended and xmit
1852  * thread flushed
1853  */
1854 static void fail_scsi_tasks(struct iscsi_conn *conn, u64 lun, int error)
1855 {
1856         struct iscsi_task *task;
1857         int i;
1858
1859         for (i = 0; i < conn->session->cmds_max; i++) {
1860                 task = conn->session->cmds[i];
1861                 if (!task->sc || task->state == ISCSI_TASK_FREE)
1862                         continue;
1863
1864                 if (lun != -1 && lun != task->sc->device->lun)
1865                         continue;
1866
1867                 ISCSI_DBG_SESSION(conn->session,
1868                                   "failing sc %p itt 0x%x state %d\n",
1869                                   task->sc, task->itt, task->state);
1870                 fail_scsi_task(task, error);
1871         }
1872 }
1873
1874 /**
1875  * iscsi_suspend_queue - suspend iscsi_queuecommand
1876  * @conn: iscsi conn to stop queueing IO on
1877  *
1878  * This grabs the session frwd_lock to make sure no one is in
1879  * xmit_task/queuecommand, and then sets suspend to prevent
1880  * new commands from being queued. This only needs to be called
1881  * by offload drivers that need to sync a path like ep disconnect
1882  * with the iscsi_queuecommand/xmit_task. To start IO again libiscsi
1883  * will call iscsi_start_tx and iscsi_unblock_session when in FFP.
1884  */
1885 void iscsi_suspend_queue(struct iscsi_conn *conn)
1886 {
1887         spin_lock_bh(&conn->session->frwd_lock);
1888         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1889         spin_unlock_bh(&conn->session->frwd_lock);
1890 }
1891 EXPORT_SYMBOL_GPL(iscsi_suspend_queue);
1892
1893 /**
1894  * iscsi_suspend_tx - suspend iscsi_data_xmit
1895  * @conn: iscsi conn tp stop processing IO on.
1896  *
1897  * This function sets the suspend bit to prevent iscsi_data_xmit
1898  * from sending new IO, and if work is queued on the xmit thread
1899  * it will wait for it to be completed.
1900  */
1901 void iscsi_suspend_tx(struct iscsi_conn *conn)
1902 {
1903         struct Scsi_Host *shost = conn->session->host;
1904         struct iscsi_host *ihost = shost_priv(shost);
1905
1906         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1907         if (ihost->workq)
1908                 flush_workqueue(ihost->workq);
1909 }
1910 EXPORT_SYMBOL_GPL(iscsi_suspend_tx);
1911
1912 static void iscsi_start_tx(struct iscsi_conn *conn)
1913 {
1914         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1915         iscsi_conn_queue_work(conn);
1916 }
1917
1918 /*
1919  * We want to make sure a ping is in flight. It has timed out.
1920  * And we are not busy processing a pdu that is making
1921  * progress but got started before the ping and is taking a while
1922  * to complete so the ping is just stuck behind it in a queue.
1923  */
1924 static int iscsi_has_ping_timed_out(struct iscsi_conn *conn)
1925 {
1926         if (conn->ping_task &&
1927             time_before_eq(conn->last_recv + (conn->recv_timeout * HZ) +
1928                            (conn->ping_timeout * HZ), jiffies))
1929                 return 1;
1930         else
1931                 return 0;
1932 }
1933
1934 enum blk_eh_timer_return iscsi_eh_cmd_timed_out(struct scsi_cmnd *sc)
1935 {
1936         enum blk_eh_timer_return rc = BLK_EH_DONE;
1937         struct iscsi_task *task = NULL, *running_task;
1938         struct iscsi_cls_session *cls_session;
1939         struct iscsi_session *session;
1940         struct iscsi_conn *conn;
1941         int i;
1942
1943         cls_session = starget_to_session(scsi_target(sc->device));
1944         session = cls_session->dd_data;
1945
1946         ISCSI_DBG_EH(session, "scsi cmd %p timedout\n", sc);
1947
1948         spin_lock_bh(&session->frwd_lock);
1949         task = (struct iscsi_task *)sc->SCp.ptr;
1950         if (!task) {
1951                 /*
1952                  * Raced with completion. Blk layer has taken ownership
1953                  * so let timeout code complete it now.
1954                  */
1955                 rc = BLK_EH_DONE;
1956                 goto done;
1957         }
1958
1959         if (session->state != ISCSI_STATE_LOGGED_IN) {
1960                 /*
1961                  * During shutdown, if session is prematurely disconnected,
1962                  * recovery won't happen and there will be hung cmds. Not
1963                  * handling cmds would trigger EH, also bad in this case.
1964                  * Instead, handle cmd, allow completion to happen and let
1965                  * upper layer to deal with the result.
1966                  */
1967                 if (unlikely(system_state != SYSTEM_RUNNING)) {
1968                         sc->result = DID_NO_CONNECT << 16;
1969                         ISCSI_DBG_EH(session, "sc on shutdown, handled\n");
1970                         rc = BLK_EH_DONE;
1971                         goto done;
1972                 }
1973                 /*
1974                  * We are probably in the middle of iscsi recovery so let
1975                  * that complete and handle the error.
1976                  */
1977                 rc = BLK_EH_RESET_TIMER;
1978                 goto done;
1979         }
1980
1981         conn = session->leadconn;
1982         if (!conn) {
1983                 /* In the middle of shuting down */
1984                 rc = BLK_EH_RESET_TIMER;
1985                 goto done;
1986         }
1987
1988         /*
1989          * If we have sent (at least queued to the network layer) a pdu or
1990          * recvd one for the task since the last timeout ask for
1991          * more time. If on the next timeout we have not made progress
1992          * we can check if it is the task or connection when we send the
1993          * nop as a ping.
1994          */
1995         if (time_after(task->last_xfer, task->last_timeout)) {
1996                 ISCSI_DBG_EH(session, "Command making progress. Asking "
1997                              "scsi-ml for more time to complete. "
1998                              "Last data xfer at %lu. Last timeout was at "
1999                              "%lu\n.", task->last_xfer, task->last_timeout);
2000                 task->have_checked_conn = false;
2001                 rc = BLK_EH_RESET_TIMER;
2002                 goto done;
2003         }
2004
2005         if (!conn->recv_timeout && !conn->ping_timeout)
2006                 goto done;
2007         /*
2008          * if the ping timedout then we are in the middle of cleaning up
2009          * and can let the iscsi eh handle it
2010          */
2011         if (iscsi_has_ping_timed_out(conn)) {
2012                 rc = BLK_EH_RESET_TIMER;
2013                 goto done;
2014         }
2015
2016         for (i = 0; i < conn->session->cmds_max; i++) {
2017                 running_task = conn->session->cmds[i];
2018                 if (!running_task->sc || running_task == task ||
2019                      running_task->state != ISCSI_TASK_RUNNING)
2020                         continue;
2021
2022                 /*
2023                  * Only check if cmds started before this one have made
2024                  * progress, or this could never fail
2025                  */
2026                 if (time_after(running_task->sc->jiffies_at_alloc,
2027                                task->sc->jiffies_at_alloc))
2028                         continue;
2029
2030                 if (time_after(running_task->last_xfer, task->last_timeout)) {
2031                         /*
2032                          * This task has not made progress, but a task
2033                          * started before us has transferred data since
2034                          * we started/last-checked. We could be queueing
2035                          * too many tasks or the LU is bad.
2036                          *
2037                          * If the device is bad the cmds ahead of us on
2038                          * other devs will complete, and this loop will
2039                          * eventually fail starting the scsi eh.
2040                          */
2041                         ISCSI_DBG_EH(session, "Command has not made progress "
2042                                      "but commands ahead of it have. "
2043                                      "Asking scsi-ml for more time to "
2044                                      "complete. Our last xfer vs running task "
2045                                      "last xfer %lu/%lu. Last check %lu.\n",
2046                                      task->last_xfer, running_task->last_xfer,
2047                                      task->last_timeout);
2048                         rc = BLK_EH_RESET_TIMER;
2049                         goto done;
2050                 }
2051         }
2052
2053         /* Assumes nop timeout is shorter than scsi cmd timeout */
2054         if (task->have_checked_conn)
2055                 goto done;
2056
2057         /*
2058          * Checking the transport already or nop from a cmd timeout still
2059          * running
2060          */
2061         if (conn->ping_task) {
2062                 task->have_checked_conn = true;
2063                 rc = BLK_EH_RESET_TIMER;
2064                 goto done;
2065         }
2066
2067         /* Make sure there is a transport check done */
2068         iscsi_send_nopout(conn, NULL);
2069         task->have_checked_conn = true;
2070         rc = BLK_EH_RESET_TIMER;
2071
2072 done:
2073         if (task)
2074                 task->last_timeout = jiffies;
2075         spin_unlock_bh(&session->frwd_lock);
2076         ISCSI_DBG_EH(session, "return %s\n", rc == BLK_EH_RESET_TIMER ?
2077                      "timer reset" : "shutdown or nh");
2078         return rc;
2079 }
2080 EXPORT_SYMBOL_GPL(iscsi_eh_cmd_timed_out);
2081
2082 static void iscsi_check_transport_timeouts(struct timer_list *t)
2083 {
2084         struct iscsi_conn *conn = from_timer(conn, t, transport_timer);
2085         struct iscsi_session *session = conn->session;
2086         unsigned long recv_timeout, next_timeout = 0, last_recv;
2087
2088         spin_lock(&session->frwd_lock);
2089         if (session->state != ISCSI_STATE_LOGGED_IN)
2090                 goto done;
2091
2092         recv_timeout = conn->recv_timeout;
2093         if (!recv_timeout)
2094                 goto done;
2095
2096         recv_timeout *= HZ;
2097         last_recv = conn->last_recv;
2098
2099         if (iscsi_has_ping_timed_out(conn)) {
2100                 iscsi_conn_printk(KERN_ERR, conn, "ping timeout of %d secs "
2101                                   "expired, recv timeout %d, last rx %lu, "
2102                                   "last ping %lu, now %lu\n",
2103                                   conn->ping_timeout, conn->recv_timeout,
2104                                   last_recv, conn->last_ping, jiffies);
2105                 spin_unlock(&session->frwd_lock);
2106                 iscsi_conn_failure(conn, ISCSI_ERR_NOP_TIMEDOUT);
2107                 return;
2108         }
2109
2110         if (time_before_eq(last_recv + recv_timeout, jiffies)) {
2111                 /* send a ping to try to provoke some traffic */
2112                 ISCSI_DBG_CONN(conn, "Sending nopout as ping\n");
2113                 if (iscsi_send_nopout(conn, NULL))
2114                         next_timeout = jiffies + (1 * HZ);
2115                 else
2116                         next_timeout = conn->last_ping + (conn->ping_timeout * HZ);
2117         } else
2118                 next_timeout = last_recv + recv_timeout;
2119
2120         ISCSI_DBG_CONN(conn, "Setting next tmo %lu\n", next_timeout);
2121         mod_timer(&conn->transport_timer, next_timeout);
2122 done:
2123         spin_unlock(&session->frwd_lock);
2124 }
2125
2126 static void iscsi_prep_abort_task_pdu(struct iscsi_task *task,
2127                                       struct iscsi_tm *hdr)
2128 {
2129         memset(hdr, 0, sizeof(*hdr));
2130         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2131         hdr->flags = ISCSI_TM_FUNC_ABORT_TASK & ISCSI_FLAG_TM_FUNC_MASK;
2132         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2133         hdr->lun = task->lun;
2134         hdr->rtt = task->hdr_itt;
2135         hdr->refcmdsn = task->cmdsn;
2136 }
2137
2138 int iscsi_eh_abort(struct scsi_cmnd *sc)
2139 {
2140         struct iscsi_cls_session *cls_session;
2141         struct iscsi_session *session;
2142         struct iscsi_conn *conn;
2143         struct iscsi_task *task;
2144         struct iscsi_tm *hdr;
2145         int age;
2146
2147         cls_session = starget_to_session(scsi_target(sc->device));
2148         session = cls_session->dd_data;
2149
2150         ISCSI_DBG_EH(session, "aborting sc %p\n", sc);
2151
2152         mutex_lock(&session->eh_mutex);
2153         spin_lock_bh(&session->frwd_lock);
2154         /*
2155          * if session was ISCSI_STATE_IN_RECOVERY then we may not have
2156          * got the command.
2157          */
2158         if (!sc->SCp.ptr) {
2159                 ISCSI_DBG_EH(session, "sc never reached iscsi layer or "
2160                                       "it completed.\n");
2161                 spin_unlock_bh(&session->frwd_lock);
2162                 mutex_unlock(&session->eh_mutex);
2163                 return SUCCESS;
2164         }
2165
2166         /*
2167          * If we are not logged in or we have started a new session
2168          * then let the host reset code handle this
2169          */
2170         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN ||
2171             sc->SCp.phase != session->age) {
2172                 spin_unlock_bh(&session->frwd_lock);
2173                 mutex_unlock(&session->eh_mutex);
2174                 ISCSI_DBG_EH(session, "failing abort due to dropped "
2175                                   "session.\n");
2176                 return FAILED;
2177         }
2178
2179         conn = session->leadconn;
2180         conn->eh_abort_cnt++;
2181         age = session->age;
2182
2183         task = (struct iscsi_task *)sc->SCp.ptr;
2184         ISCSI_DBG_EH(session, "aborting [sc %p itt 0x%x]\n",
2185                      sc, task->itt);
2186
2187         /* task completed before time out */
2188         if (!task->sc) {
2189                 ISCSI_DBG_EH(session, "sc completed while abort in progress\n");
2190                 goto success;
2191         }
2192
2193         if (task->state == ISCSI_TASK_PENDING) {
2194                 fail_scsi_task(task, DID_ABORT);
2195                 goto success;
2196         }
2197
2198         /* only have one tmf outstanding at a time */
2199         if (conn->tmf_state != TMF_INITIAL)
2200                 goto failed;
2201         conn->tmf_state = TMF_QUEUED;
2202
2203         hdr = &conn->tmhdr;
2204         iscsi_prep_abort_task_pdu(task, hdr);
2205
2206         if (iscsi_exec_task_mgmt_fn(conn, hdr, age, session->abort_timeout))
2207                 goto failed;
2208
2209         switch (conn->tmf_state) {
2210         case TMF_SUCCESS:
2211                 spin_unlock_bh(&session->frwd_lock);
2212                 /*
2213                  * stop tx side incase the target had sent a abort rsp but
2214                  * the initiator was still writing out data.
2215                  */
2216                 iscsi_suspend_tx(conn);
2217                 /*
2218                  * we do not stop the recv side because targets have been
2219                  * good and have never sent us a successful tmf response
2220                  * then sent more data for the cmd.
2221                  */
2222                 spin_lock_bh(&session->frwd_lock);
2223                 fail_scsi_task(task, DID_ABORT);
2224                 conn->tmf_state = TMF_INITIAL;
2225                 memset(hdr, 0, sizeof(*hdr));
2226                 spin_unlock_bh(&session->frwd_lock);
2227                 iscsi_start_tx(conn);
2228                 goto success_unlocked;
2229         case TMF_TIMEDOUT:
2230                 spin_unlock_bh(&session->frwd_lock);
2231                 iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2232                 goto failed_unlocked;
2233         case TMF_NOT_FOUND:
2234                 if (!sc->SCp.ptr) {
2235                         conn->tmf_state = TMF_INITIAL;
2236                         memset(hdr, 0, sizeof(*hdr));
2237                         /* task completed before tmf abort response */
2238                         ISCSI_DBG_EH(session, "sc completed while abort in "
2239                                               "progress\n");
2240                         goto success;
2241                 }
2242                 fallthrough;
2243         default:
2244                 conn->tmf_state = TMF_INITIAL;
2245                 goto failed;
2246         }
2247
2248 success:
2249         spin_unlock_bh(&session->frwd_lock);
2250 success_unlocked:
2251         ISCSI_DBG_EH(session, "abort success [sc %p itt 0x%x]\n",
2252                      sc, task->itt);
2253         mutex_unlock(&session->eh_mutex);
2254         return SUCCESS;
2255
2256 failed:
2257         spin_unlock_bh(&session->frwd_lock);
2258 failed_unlocked:
2259         ISCSI_DBG_EH(session, "abort failed [sc %p itt 0x%x]\n", sc,
2260                      task ? task->itt : 0);
2261         mutex_unlock(&session->eh_mutex);
2262         return FAILED;
2263 }
2264 EXPORT_SYMBOL_GPL(iscsi_eh_abort);
2265
2266 static void iscsi_prep_lun_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
2267 {
2268         memset(hdr, 0, sizeof(*hdr));
2269         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2270         hdr->flags = ISCSI_TM_FUNC_LOGICAL_UNIT_RESET & ISCSI_FLAG_TM_FUNC_MASK;
2271         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2272         int_to_scsilun(sc->device->lun, &hdr->lun);
2273         hdr->rtt = RESERVED_ITT;
2274 }
2275
2276 int iscsi_eh_device_reset(struct scsi_cmnd *sc)
2277 {
2278         struct iscsi_cls_session *cls_session;
2279         struct iscsi_session *session;
2280         struct iscsi_conn *conn;
2281         struct iscsi_tm *hdr;
2282         int rc = FAILED;
2283
2284         cls_session = starget_to_session(scsi_target(sc->device));
2285         session = cls_session->dd_data;
2286
2287         ISCSI_DBG_EH(session, "LU Reset [sc %p lun %llu]\n", sc,
2288                      sc->device->lun);
2289
2290         mutex_lock(&session->eh_mutex);
2291         spin_lock_bh(&session->frwd_lock);
2292         /*
2293          * Just check if we are not logged in. We cannot check for
2294          * the phase because the reset could come from a ioctl.
2295          */
2296         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
2297                 goto unlock;
2298         conn = session->leadconn;
2299
2300         /* only have one tmf outstanding at a time */
2301         if (conn->tmf_state != TMF_INITIAL)
2302                 goto unlock;
2303         conn->tmf_state = TMF_QUEUED;
2304
2305         hdr = &conn->tmhdr;
2306         iscsi_prep_lun_reset_pdu(sc, hdr);
2307
2308         if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
2309                                     session->lu_reset_timeout)) {
2310                 rc = FAILED;
2311                 goto unlock;
2312         }
2313
2314         switch (conn->tmf_state) {
2315         case TMF_SUCCESS:
2316                 break;
2317         case TMF_TIMEDOUT:
2318                 spin_unlock_bh(&session->frwd_lock);
2319                 iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2320                 goto done;
2321         default:
2322                 conn->tmf_state = TMF_INITIAL;
2323                 goto unlock;
2324         }
2325
2326         rc = SUCCESS;
2327         spin_unlock_bh(&session->frwd_lock);
2328
2329         iscsi_suspend_tx(conn);
2330
2331         spin_lock_bh(&session->frwd_lock);
2332         memset(hdr, 0, sizeof(*hdr));
2333         fail_scsi_tasks(conn, sc->device->lun, DID_ERROR);
2334         conn->tmf_state = TMF_INITIAL;
2335         spin_unlock_bh(&session->frwd_lock);
2336
2337         iscsi_start_tx(conn);
2338         goto done;
2339
2340 unlock:
2341         spin_unlock_bh(&session->frwd_lock);
2342 done:
2343         ISCSI_DBG_EH(session, "dev reset result = %s\n",
2344                      rc == SUCCESS ? "SUCCESS" : "FAILED");
2345         mutex_unlock(&session->eh_mutex);
2346         return rc;
2347 }
2348 EXPORT_SYMBOL_GPL(iscsi_eh_device_reset);
2349
2350 void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
2351 {
2352         struct iscsi_session *session = cls_session->dd_data;
2353
2354         spin_lock_bh(&session->frwd_lock);
2355         if (session->state != ISCSI_STATE_LOGGED_IN) {
2356                 session->state = ISCSI_STATE_RECOVERY_FAILED;
2357                 if (session->leadconn)
2358                         wake_up(&session->leadconn->ehwait);
2359         }
2360         spin_unlock_bh(&session->frwd_lock);
2361 }
2362 EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
2363
2364 /**
2365  * iscsi_eh_session_reset - drop session and attempt relogin
2366  * @sc: scsi command
2367  *
2368  * This function will wait for a relogin, session termination from
2369  * userspace, or a recovery/replacement timeout.
2370  */
2371 int iscsi_eh_session_reset(struct scsi_cmnd *sc)
2372 {
2373         struct iscsi_cls_session *cls_session;
2374         struct iscsi_session *session;
2375         struct iscsi_conn *conn;
2376
2377         cls_session = starget_to_session(scsi_target(sc->device));
2378         session = cls_session->dd_data;
2379         conn = session->leadconn;
2380
2381         mutex_lock(&session->eh_mutex);
2382         spin_lock_bh(&session->frwd_lock);
2383         if (session->state == ISCSI_STATE_TERMINATE) {
2384 failed:
2385                 ISCSI_DBG_EH(session,
2386                              "failing session reset: Could not log back into "
2387                              "%s [age %d]\n", session->targetname,
2388                              session->age);
2389                 spin_unlock_bh(&session->frwd_lock);
2390                 mutex_unlock(&session->eh_mutex);
2391                 return FAILED;
2392         }
2393
2394         spin_unlock_bh(&session->frwd_lock);
2395         mutex_unlock(&session->eh_mutex);
2396         /*
2397          * we drop the lock here but the leadconn cannot be destoyed while
2398          * we are in the scsi eh
2399          */
2400         iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2401
2402         ISCSI_DBG_EH(session, "wait for relogin\n");
2403         wait_event_interruptible(conn->ehwait,
2404                                  session->state == ISCSI_STATE_TERMINATE ||
2405                                  session->state == ISCSI_STATE_LOGGED_IN ||
2406                                  session->state == ISCSI_STATE_RECOVERY_FAILED);
2407         if (signal_pending(current))
2408                 flush_signals(current);
2409
2410         mutex_lock(&session->eh_mutex);
2411         spin_lock_bh(&session->frwd_lock);
2412         if (session->state == ISCSI_STATE_LOGGED_IN) {
2413                 ISCSI_DBG_EH(session,
2414                              "session reset succeeded for %s,%s\n",
2415                              session->targetname, conn->persistent_address);
2416         } else
2417                 goto failed;
2418         spin_unlock_bh(&session->frwd_lock);
2419         mutex_unlock(&session->eh_mutex);
2420         return SUCCESS;
2421 }
2422 EXPORT_SYMBOL_GPL(iscsi_eh_session_reset);
2423
2424 static void iscsi_prep_tgt_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
2425 {
2426         memset(hdr, 0, sizeof(*hdr));
2427         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2428         hdr->flags = ISCSI_TM_FUNC_TARGET_WARM_RESET & ISCSI_FLAG_TM_FUNC_MASK;
2429         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2430         hdr->rtt = RESERVED_ITT;
2431 }
2432
2433 /**
2434  * iscsi_eh_target_reset - reset target
2435  * @sc: scsi command
2436  *
2437  * This will attempt to send a warm target reset.
2438  */
2439 static int iscsi_eh_target_reset(struct scsi_cmnd *sc)
2440 {
2441         struct iscsi_cls_session *cls_session;
2442         struct iscsi_session *session;
2443         struct iscsi_conn *conn;
2444         struct iscsi_tm *hdr;
2445         int rc = FAILED;
2446
2447         cls_session = starget_to_session(scsi_target(sc->device));
2448         session = cls_session->dd_data;
2449
2450         ISCSI_DBG_EH(session, "tgt Reset [sc %p tgt %s]\n", sc,
2451                      session->targetname);
2452
2453         mutex_lock(&session->eh_mutex);
2454         spin_lock_bh(&session->frwd_lock);
2455         /*
2456          * Just check if we are not logged in. We cannot check for
2457          * the phase because the reset could come from a ioctl.
2458          */
2459         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
2460                 goto unlock;
2461         conn = session->leadconn;
2462
2463         /* only have one tmf outstanding at a time */
2464         if (conn->tmf_state != TMF_INITIAL)
2465                 goto unlock;
2466         conn->tmf_state = TMF_QUEUED;
2467
2468         hdr = &conn->tmhdr;
2469         iscsi_prep_tgt_reset_pdu(sc, hdr);
2470
2471         if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
2472                                     session->tgt_reset_timeout)) {
2473                 rc = FAILED;
2474                 goto unlock;
2475         }
2476
2477         switch (conn->tmf_state) {
2478         case TMF_SUCCESS:
2479                 break;
2480         case TMF_TIMEDOUT:
2481                 spin_unlock_bh(&session->frwd_lock);
2482                 iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2483                 goto done;
2484         default:
2485                 conn->tmf_state = TMF_INITIAL;
2486                 goto unlock;
2487         }
2488
2489         rc = SUCCESS;
2490         spin_unlock_bh(&session->frwd_lock);
2491
2492         iscsi_suspend_tx(conn);
2493
2494         spin_lock_bh(&session->frwd_lock);
2495         memset(hdr, 0, sizeof(*hdr));
2496         fail_scsi_tasks(conn, -1, DID_ERROR);
2497         conn->tmf_state = TMF_INITIAL;
2498         spin_unlock_bh(&session->frwd_lock);
2499
2500         iscsi_start_tx(conn);
2501         goto done;
2502
2503 unlock:
2504         spin_unlock_bh(&session->frwd_lock);
2505 done:
2506         ISCSI_DBG_EH(session, "tgt %s reset result = %s\n", session->targetname,
2507                      rc == SUCCESS ? "SUCCESS" : "FAILED");
2508         mutex_unlock(&session->eh_mutex);
2509         return rc;
2510 }
2511
2512 /**
2513  * iscsi_eh_recover_target - reset target and possibly the session
2514  * @sc: scsi command
2515  *
2516  * This will attempt to send a warm target reset. If that fails,
2517  * we will escalate to ERL0 session recovery.
2518  */
2519 int iscsi_eh_recover_target(struct scsi_cmnd *sc)
2520 {
2521         int rc;
2522
2523         rc = iscsi_eh_target_reset(sc);
2524         if (rc == FAILED)
2525                 rc = iscsi_eh_session_reset(sc);
2526         return rc;
2527 }
2528 EXPORT_SYMBOL_GPL(iscsi_eh_recover_target);
2529
2530 /*
2531  * Pre-allocate a pool of @max items of @item_size. By default, the pool
2532  * should be accessed via kfifo_{get,put} on q->queue.
2533  * Optionally, the caller can obtain the array of object pointers
2534  * by passing in a non-NULL @items pointer
2535  */
2536 int
2537 iscsi_pool_init(struct iscsi_pool *q, int max, void ***items, int item_size)
2538 {
2539         int i, num_arrays = 1;
2540
2541         memset(q, 0, sizeof(*q));
2542
2543         q->max = max;
2544
2545         /* If the user passed an items pointer, he wants a copy of
2546          * the array. */
2547         if (items)
2548                 num_arrays++;
2549         q->pool = kvcalloc(num_arrays * max, sizeof(void *), GFP_KERNEL);
2550         if (q->pool == NULL)
2551                 return -ENOMEM;
2552
2553         kfifo_init(&q->queue, (void*)q->pool, max * sizeof(void*));
2554
2555         for (i = 0; i < max; i++) {
2556                 q->pool[i] = kzalloc(item_size, GFP_KERNEL);
2557                 if (q->pool[i] == NULL) {
2558                         q->max = i;
2559                         goto enomem;
2560                 }
2561                 kfifo_in(&q->queue, (void*)&q->pool[i], sizeof(void*));
2562         }
2563
2564         if (items) {
2565                 *items = q->pool + max;
2566                 memcpy(*items, q->pool, max * sizeof(void *));
2567         }
2568
2569         return 0;
2570
2571 enomem:
2572         iscsi_pool_free(q);
2573         return -ENOMEM;
2574 }
2575 EXPORT_SYMBOL_GPL(iscsi_pool_init);
2576
2577 void iscsi_pool_free(struct iscsi_pool *q)
2578 {
2579         int i;
2580
2581         for (i = 0; i < q->max; i++)
2582                 kfree(q->pool[i]);
2583         kvfree(q->pool);
2584 }
2585 EXPORT_SYMBOL_GPL(iscsi_pool_free);
2586
2587 /**
2588  * iscsi_host_add - add host to system
2589  * @shost: scsi host
2590  * @pdev: parent device
2591  *
2592  * This should be called by partial offload and software iscsi drivers
2593  * to add a host to the system.
2594  */
2595 int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev)
2596 {
2597         if (!shost->can_queue)
2598                 shost->can_queue = ISCSI_DEF_XMIT_CMDS_MAX;
2599
2600         if (!shost->cmd_per_lun)
2601                 shost->cmd_per_lun = ISCSI_DEF_CMD_PER_LUN;
2602
2603         return scsi_add_host(shost, pdev);
2604 }
2605 EXPORT_SYMBOL_GPL(iscsi_host_add);
2606
2607 /**
2608  * iscsi_host_alloc - allocate a host and driver data
2609  * @sht: scsi host template
2610  * @dd_data_size: driver host data size
2611  * @xmit_can_sleep: bool indicating if LLD will queue IO from a work queue
2612  *
2613  * This should be called by partial offload and software iscsi drivers.
2614  * To access the driver specific memory use the iscsi_host_priv() macro.
2615  */
2616 struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
2617                                    int dd_data_size, bool xmit_can_sleep)
2618 {
2619         struct Scsi_Host *shost;
2620         struct iscsi_host *ihost;
2621
2622         shost = scsi_host_alloc(sht, sizeof(struct iscsi_host) + dd_data_size);
2623         if (!shost)
2624                 return NULL;
2625         ihost = shost_priv(shost);
2626
2627         if (xmit_can_sleep) {
2628                 snprintf(ihost->workq_name, sizeof(ihost->workq_name),
2629                         "iscsi_q_%d", shost->host_no);
2630                 ihost->workq = alloc_workqueue("%s",
2631                         WQ_SYSFS | __WQ_LEGACY | WQ_MEM_RECLAIM | WQ_UNBOUND,
2632                         1, ihost->workq_name);
2633                 if (!ihost->workq)
2634                         goto free_host;
2635         }
2636
2637         spin_lock_init(&ihost->lock);
2638         ihost->state = ISCSI_HOST_SETUP;
2639         ihost->num_sessions = 0;
2640         init_waitqueue_head(&ihost->session_removal_wq);
2641         return shost;
2642
2643 free_host:
2644         scsi_host_put(shost);
2645         return NULL;
2646 }
2647 EXPORT_SYMBOL_GPL(iscsi_host_alloc);
2648
2649 static void iscsi_notify_host_removed(struct iscsi_cls_session *cls_session)
2650 {
2651         iscsi_session_failure(cls_session->dd_data, ISCSI_ERR_INVALID_HOST);
2652 }
2653
2654 /**
2655  * iscsi_host_remove - remove host and sessions
2656  * @shost: scsi host
2657  *
2658  * If there are any sessions left, this will initiate the removal and wait
2659  * for the completion.
2660  */
2661 void iscsi_host_remove(struct Scsi_Host *shost)
2662 {
2663         struct iscsi_host *ihost = shost_priv(shost);
2664         unsigned long flags;
2665
2666         spin_lock_irqsave(&ihost->lock, flags);
2667         ihost->state = ISCSI_HOST_REMOVED;
2668         spin_unlock_irqrestore(&ihost->lock, flags);
2669
2670         iscsi_host_for_each_session(shost, iscsi_notify_host_removed);
2671         wait_event_interruptible(ihost->session_removal_wq,
2672                                  ihost->num_sessions == 0);
2673         if (signal_pending(current))
2674                 flush_signals(current);
2675
2676         scsi_remove_host(shost);
2677         if (ihost->workq)
2678                 destroy_workqueue(ihost->workq);
2679 }
2680 EXPORT_SYMBOL_GPL(iscsi_host_remove);
2681
2682 void iscsi_host_free(struct Scsi_Host *shost)
2683 {
2684         struct iscsi_host *ihost = shost_priv(shost);
2685
2686         kfree(ihost->netdev);
2687         kfree(ihost->hwaddress);
2688         kfree(ihost->initiatorname);
2689         scsi_host_put(shost);
2690 }
2691 EXPORT_SYMBOL_GPL(iscsi_host_free);
2692
2693 static void iscsi_host_dec_session_cnt(struct Scsi_Host *shost)
2694 {
2695         struct iscsi_host *ihost = shost_priv(shost);
2696         unsigned long flags;
2697
2698         shost = scsi_host_get(shost);
2699         if (!shost) {
2700                 printk(KERN_ERR "Invalid state. Cannot notify host removal "
2701                       "of session teardown event because host already "
2702                       "removed.\n");
2703                 return;
2704         }
2705
2706         spin_lock_irqsave(&ihost->lock, flags);
2707         ihost->num_sessions--;
2708         if (ihost->num_sessions == 0)
2709                 wake_up(&ihost->session_removal_wq);
2710         spin_unlock_irqrestore(&ihost->lock, flags);
2711         scsi_host_put(shost);
2712 }
2713
2714 /**
2715  * iscsi_session_setup - create iscsi cls session and host and session
2716  * @iscsit: iscsi transport template
2717  * @shost: scsi host
2718  * @cmds_max: session can queue
2719  * @dd_size: private driver data size, added to session allocation size
2720  * @cmd_task_size: LLD task private data size
2721  * @initial_cmdsn: initial CmdSN
2722  * @id: target ID to add to this session
2723  *
2724  * This can be used by software iscsi_transports that allocate
2725  * a session per scsi host.
2726  *
2727  * Callers should set cmds_max to the largest total numer (mgmt + scsi) of
2728  * tasks they support. The iscsi layer reserves ISCSI_MGMT_CMDS_MAX tasks
2729  * for nop handling and login/logout requests.
2730  */
2731 struct iscsi_cls_session *
2732 iscsi_session_setup(struct iscsi_transport *iscsit, struct Scsi_Host *shost,
2733                     uint16_t cmds_max, int dd_size, int cmd_task_size,
2734                     uint32_t initial_cmdsn, unsigned int id)
2735 {
2736         struct iscsi_host *ihost = shost_priv(shost);
2737         struct iscsi_session *session;
2738         struct iscsi_cls_session *cls_session;
2739         int cmd_i, scsi_cmds, total_cmds = cmds_max;
2740         unsigned long flags;
2741
2742         spin_lock_irqsave(&ihost->lock, flags);
2743         if (ihost->state == ISCSI_HOST_REMOVED) {
2744                 spin_unlock_irqrestore(&ihost->lock, flags);
2745                 return NULL;
2746         }
2747         ihost->num_sessions++;
2748         spin_unlock_irqrestore(&ihost->lock, flags);
2749
2750         if (!total_cmds)
2751                 total_cmds = ISCSI_DEF_XMIT_CMDS_MAX;
2752         /*
2753          * The iscsi layer needs some tasks for nop handling and tmfs,
2754          * so the cmds_max must at least be greater than ISCSI_MGMT_CMDS_MAX
2755          * + 1 command for scsi IO.
2756          */
2757         if (total_cmds < ISCSI_TOTAL_CMDS_MIN) {
2758                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2759                        "must be a power of two that is at least %d.\n",
2760                        total_cmds, ISCSI_TOTAL_CMDS_MIN);
2761                 goto dec_session_count;
2762         }
2763
2764         if (total_cmds > ISCSI_TOTAL_CMDS_MAX) {
2765                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2766                        "must be a power of 2 less than or equal to %d.\n",
2767                        cmds_max, ISCSI_TOTAL_CMDS_MAX);
2768                 total_cmds = ISCSI_TOTAL_CMDS_MAX;
2769         }
2770
2771         if (!is_power_of_2(total_cmds)) {
2772                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2773                        "must be a power of 2.\n", total_cmds);
2774                 total_cmds = rounddown_pow_of_two(total_cmds);
2775                 if (total_cmds < ISCSI_TOTAL_CMDS_MIN)
2776                         goto dec_session_count;
2777                 printk(KERN_INFO "iscsi: Rounding can_queue to %d.\n",
2778                        total_cmds);
2779         }
2780         scsi_cmds = total_cmds - ISCSI_MGMT_CMDS_MAX;
2781
2782         cls_session = iscsi_alloc_session(shost, iscsit,
2783                                           sizeof(struct iscsi_session) +
2784                                           dd_size);
2785         if (!cls_session)
2786                 goto dec_session_count;
2787         session = cls_session->dd_data;
2788         session->cls_session = cls_session;
2789         session->host = shost;
2790         session->state = ISCSI_STATE_FREE;
2791         session->fast_abort = 1;
2792         session->tgt_reset_timeout = 30;
2793         session->lu_reset_timeout = 15;
2794         session->abort_timeout = 10;
2795         session->scsi_cmds_max = scsi_cmds;
2796         session->cmds_max = total_cmds;
2797         session->queued_cmdsn = session->cmdsn = initial_cmdsn;
2798         session->exp_cmdsn = initial_cmdsn + 1;
2799         session->max_cmdsn = initial_cmdsn + 1;
2800         session->max_r2t = 1;
2801         session->tt = iscsit;
2802         session->dd_data = cls_session->dd_data + sizeof(*session);
2803
2804         mutex_init(&session->eh_mutex);
2805         spin_lock_init(&session->frwd_lock);
2806         spin_lock_init(&session->back_lock);
2807
2808         /* initialize SCSI PDU commands pool */
2809         if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
2810                             (void***)&session->cmds,
2811                             cmd_task_size + sizeof(struct iscsi_task)))
2812                 goto cmdpool_alloc_fail;
2813
2814         /* pre-format cmds pool with ITT */
2815         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
2816                 struct iscsi_task *task = session->cmds[cmd_i];
2817
2818                 if (cmd_task_size)
2819                         task->dd_data = &task[1];
2820                 task->itt = cmd_i;
2821                 task->state = ISCSI_TASK_FREE;
2822                 INIT_LIST_HEAD(&task->running);
2823         }
2824
2825         if (!try_module_get(iscsit->owner))
2826                 goto module_get_fail;
2827
2828         if (iscsi_add_session(cls_session, id))
2829                 goto cls_session_fail;
2830
2831         return cls_session;
2832
2833 cls_session_fail:
2834         module_put(iscsit->owner);
2835 module_get_fail:
2836         iscsi_pool_free(&session->cmdpool);
2837 cmdpool_alloc_fail:
2838         iscsi_free_session(cls_session);
2839 dec_session_count:
2840         iscsi_host_dec_session_cnt(shost);
2841         return NULL;
2842 }
2843 EXPORT_SYMBOL_GPL(iscsi_session_setup);
2844
2845 /**
2846  * iscsi_session_teardown - destroy session, host, and cls_session
2847  * @cls_session: iscsi session
2848  */
2849 void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
2850 {
2851         struct iscsi_session *session = cls_session->dd_data;
2852         struct module *owner = cls_session->transport->owner;
2853         struct Scsi_Host *shost = session->host;
2854
2855         iscsi_pool_free(&session->cmdpool);
2856
2857         iscsi_remove_session(cls_session);
2858
2859         kfree(session->password);
2860         kfree(session->password_in);
2861         kfree(session->username);
2862         kfree(session->username_in);
2863         kfree(session->targetname);
2864         kfree(session->targetalias);
2865         kfree(session->initiatorname);
2866         kfree(session->boot_root);
2867         kfree(session->boot_nic);
2868         kfree(session->boot_target);
2869         kfree(session->ifacename);
2870         kfree(session->portal_type);
2871         kfree(session->discovery_parent_type);
2872
2873         iscsi_free_session(cls_session);
2874
2875         iscsi_host_dec_session_cnt(shost);
2876         module_put(owner);
2877 }
2878 EXPORT_SYMBOL_GPL(iscsi_session_teardown);
2879
2880 /**
2881  * iscsi_conn_setup - create iscsi_cls_conn and iscsi_conn
2882  * @cls_session: iscsi_cls_session
2883  * @dd_size: private driver data size
2884  * @conn_idx: cid
2885  */
2886 struct iscsi_cls_conn *
2887 iscsi_conn_setup(struct iscsi_cls_session *cls_session, int dd_size,
2888                  uint32_t conn_idx)
2889 {
2890         struct iscsi_session *session = cls_session->dd_data;
2891         struct iscsi_conn *conn;
2892         struct iscsi_cls_conn *cls_conn;
2893         char *data;
2894
2895         cls_conn = iscsi_create_conn(cls_session, sizeof(*conn) + dd_size,
2896                                      conn_idx);
2897         if (!cls_conn)
2898                 return NULL;
2899         conn = cls_conn->dd_data;
2900         memset(conn, 0, sizeof(*conn) + dd_size);
2901
2902         conn->dd_data = cls_conn->dd_data + sizeof(*conn);
2903         conn->session = session;
2904         conn->cls_conn = cls_conn;
2905         conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
2906         conn->id = conn_idx;
2907         conn->exp_statsn = 0;
2908         conn->tmf_state = TMF_INITIAL;
2909
2910         timer_setup(&conn->transport_timer, iscsi_check_transport_timeouts, 0);
2911
2912         INIT_LIST_HEAD(&conn->mgmtqueue);
2913         INIT_LIST_HEAD(&conn->cmdqueue);
2914         INIT_LIST_HEAD(&conn->requeue);
2915         spin_lock_init(&conn->taskqueuelock);
2916         INIT_WORK(&conn->xmitwork, iscsi_xmitworker);
2917
2918         /* allocate login_task used for the login/text sequences */
2919         spin_lock_bh(&session->frwd_lock);
2920         if (!kfifo_out(&session->cmdpool.queue,
2921                          (void*)&conn->login_task,
2922                          sizeof(void*))) {
2923                 spin_unlock_bh(&session->frwd_lock);
2924                 goto login_task_alloc_fail;
2925         }
2926         spin_unlock_bh(&session->frwd_lock);
2927
2928         data = (char *) __get_free_pages(GFP_KERNEL,
2929                                          get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
2930         if (!data)
2931                 goto login_task_data_alloc_fail;
2932         conn->login_task->data = conn->data = data;
2933
2934         timer_setup(&conn->tmf_timer, iscsi_tmf_timedout, 0);
2935         init_waitqueue_head(&conn->ehwait);
2936
2937         return cls_conn;
2938
2939 login_task_data_alloc_fail:
2940         kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
2941                     sizeof(void*));
2942 login_task_alloc_fail:
2943         iscsi_destroy_conn(cls_conn);
2944         return NULL;
2945 }
2946 EXPORT_SYMBOL_GPL(iscsi_conn_setup);
2947
2948 /**
2949  * iscsi_conn_teardown - teardown iscsi connection
2950  * @cls_conn: iscsi class connection
2951  *
2952  * TODO: we may need to make this into a two step process
2953  * like scsi-mls remove + put host
2954  */
2955 void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
2956 {
2957         struct iscsi_conn *conn = cls_conn->dd_data;
2958         struct iscsi_session *session = conn->session;
2959
2960         del_timer_sync(&conn->transport_timer);
2961
2962         mutex_lock(&session->eh_mutex);
2963         spin_lock_bh(&session->frwd_lock);
2964         conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
2965         if (session->leadconn == conn) {
2966                 /*
2967                  * leading connection? then give up on recovery.
2968                  */
2969                 session->state = ISCSI_STATE_TERMINATE;
2970                 wake_up(&conn->ehwait);
2971         }
2972         spin_unlock_bh(&session->frwd_lock);
2973
2974         /* flush queued up work because we free the connection below */
2975         iscsi_suspend_tx(conn);
2976
2977         spin_lock_bh(&session->frwd_lock);
2978         free_pages((unsigned long) conn->data,
2979                    get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
2980         kfree(conn->persistent_address);
2981         kfree(conn->local_ipaddr);
2982         /* regular RX path uses back_lock */
2983         spin_lock_bh(&session->back_lock);
2984         kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
2985                     sizeof(void*));
2986         spin_unlock_bh(&session->back_lock);
2987         if (session->leadconn == conn)
2988                 session->leadconn = NULL;
2989         spin_unlock_bh(&session->frwd_lock);
2990         mutex_unlock(&session->eh_mutex);
2991
2992         iscsi_destroy_conn(cls_conn);
2993 }
2994 EXPORT_SYMBOL_GPL(iscsi_conn_teardown);
2995
2996 int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
2997 {
2998         struct iscsi_conn *conn = cls_conn->dd_data;
2999         struct iscsi_session *session = conn->session;
3000
3001         if (!session) {
3002                 iscsi_conn_printk(KERN_ERR, conn,
3003                                   "can't start unbound connection\n");
3004                 return -EPERM;
3005         }
3006
3007         if ((session->imm_data_en || !session->initial_r2t_en) &&
3008              session->first_burst > session->max_burst) {
3009                 iscsi_conn_printk(KERN_INFO, conn, "invalid burst lengths: "
3010                                   "first_burst %d max_burst %d\n",
3011                                   session->first_burst, session->max_burst);
3012                 return -EINVAL;
3013         }
3014
3015         if (conn->ping_timeout && !conn->recv_timeout) {
3016                 iscsi_conn_printk(KERN_ERR, conn, "invalid recv timeout of "
3017                                   "zero. Using 5 seconds\n.");
3018                 conn->recv_timeout = 5;
3019         }
3020
3021         if (conn->recv_timeout && !conn->ping_timeout) {
3022                 iscsi_conn_printk(KERN_ERR, conn, "invalid ping timeout of "
3023                                   "zero. Using 5 seconds.\n");
3024                 conn->ping_timeout = 5;
3025         }
3026
3027         spin_lock_bh(&session->frwd_lock);
3028         conn->c_stage = ISCSI_CONN_STARTED;
3029         session->state = ISCSI_STATE_LOGGED_IN;
3030         session->queued_cmdsn = session->cmdsn;
3031
3032         conn->last_recv = jiffies;
3033         conn->last_ping = jiffies;
3034         if (conn->recv_timeout && conn->ping_timeout)
3035                 mod_timer(&conn->transport_timer,
3036                           jiffies + (conn->recv_timeout * HZ));
3037
3038         switch(conn->stop_stage) {
3039         case STOP_CONN_RECOVER:
3040                 /*
3041                  * unblock eh_abort() if it is blocked. re-try all
3042                  * commands after successful recovery
3043                  */
3044                 conn->stop_stage = 0;
3045                 conn->tmf_state = TMF_INITIAL;
3046                 session->age++;
3047                 if (session->age == 16)
3048                         session->age = 0;
3049                 break;
3050         case STOP_CONN_TERM:
3051                 conn->stop_stage = 0;
3052                 break;
3053         default:
3054                 break;
3055         }
3056         spin_unlock_bh(&session->frwd_lock);
3057
3058         iscsi_unblock_session(session->cls_session);
3059         wake_up(&conn->ehwait);
3060         return 0;
3061 }
3062 EXPORT_SYMBOL_GPL(iscsi_conn_start);
3063
3064 static void
3065 fail_mgmt_tasks(struct iscsi_session *session, struct iscsi_conn *conn)
3066 {
3067         struct iscsi_task *task;
3068         int i, state;
3069
3070         for (i = 0; i < conn->session->cmds_max; i++) {
3071                 task = conn->session->cmds[i];
3072                 if (task->sc)
3073                         continue;
3074
3075                 if (task->state == ISCSI_TASK_FREE)
3076                         continue;
3077
3078                 ISCSI_DBG_SESSION(conn->session,
3079                                   "failing mgmt itt 0x%x state %d\n",
3080                                   task->itt, task->state);
3081                 state = ISCSI_TASK_ABRT_SESS_RECOV;
3082                 if (task->state == ISCSI_TASK_PENDING)
3083                         state = ISCSI_TASK_COMPLETED;
3084                 spin_lock_bh(&session->back_lock);
3085                 iscsi_complete_task(task, state);
3086                 spin_unlock_bh(&session->back_lock);
3087         }
3088 }
3089
3090 static void iscsi_start_session_recovery(struct iscsi_session *session,
3091                                          struct iscsi_conn *conn, int flag)
3092 {
3093         int old_stop_stage;
3094
3095         mutex_lock(&session->eh_mutex);
3096         spin_lock_bh(&session->frwd_lock);
3097         if (conn->stop_stage == STOP_CONN_TERM) {
3098                 spin_unlock_bh(&session->frwd_lock);
3099                 mutex_unlock(&session->eh_mutex);
3100                 return;
3101         }
3102
3103         /*
3104          * When this is called for the in_login state, we only want to clean
3105          * up the login task and connection. We do not need to block and set
3106          * the recovery state again
3107          */
3108         if (flag == STOP_CONN_TERM)
3109                 session->state = ISCSI_STATE_TERMINATE;
3110         else if (conn->stop_stage != STOP_CONN_RECOVER)
3111                 session->state = ISCSI_STATE_IN_RECOVERY;
3112
3113         old_stop_stage = conn->stop_stage;
3114         conn->stop_stage = flag;
3115         spin_unlock_bh(&session->frwd_lock);
3116
3117         del_timer_sync(&conn->transport_timer);
3118         iscsi_suspend_tx(conn);
3119
3120         spin_lock_bh(&session->frwd_lock);
3121         conn->c_stage = ISCSI_CONN_STOPPED;
3122         spin_unlock_bh(&session->frwd_lock);
3123
3124         /*
3125          * for connection level recovery we should not calculate
3126          * header digest. conn->hdr_size used for optimization
3127          * in hdr_extract() and will be re-negotiated at
3128          * set_param() time.
3129          */
3130         if (flag == STOP_CONN_RECOVER) {
3131                 conn->hdrdgst_en = 0;
3132                 conn->datadgst_en = 0;
3133                 if (session->state == ISCSI_STATE_IN_RECOVERY &&
3134                     old_stop_stage != STOP_CONN_RECOVER) {
3135                         ISCSI_DBG_SESSION(session, "blocking session\n");
3136                         iscsi_block_session(session->cls_session);
3137                 }
3138         }
3139
3140         /*
3141          * flush queues.
3142          */
3143         spin_lock_bh(&session->frwd_lock);
3144         fail_scsi_tasks(conn, -1, DID_TRANSPORT_DISRUPTED);
3145         fail_mgmt_tasks(session, conn);
3146         memset(&conn->tmhdr, 0, sizeof(conn->tmhdr));
3147         spin_unlock_bh(&session->frwd_lock);
3148         mutex_unlock(&session->eh_mutex);
3149 }
3150
3151 void iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
3152 {
3153         struct iscsi_conn *conn = cls_conn->dd_data;
3154         struct iscsi_session *session = conn->session;
3155
3156         switch (flag) {
3157         case STOP_CONN_RECOVER:
3158                 cls_conn->state = ISCSI_CONN_FAILED;
3159                 break;
3160         case STOP_CONN_TERM:
3161                 cls_conn->state = ISCSI_CONN_DOWN;
3162                 break;
3163         default:
3164                 iscsi_conn_printk(KERN_ERR, conn,
3165                                   "invalid stop flag %d\n", flag);
3166                 return;
3167         }
3168
3169         iscsi_start_session_recovery(session, conn, flag);
3170 }
3171 EXPORT_SYMBOL_GPL(iscsi_conn_stop);
3172
3173 int iscsi_conn_bind(struct iscsi_cls_session *cls_session,
3174                     struct iscsi_cls_conn *cls_conn, int is_leading)
3175 {
3176         struct iscsi_session *session = cls_session->dd_data;
3177         struct iscsi_conn *conn = cls_conn->dd_data;
3178
3179         spin_lock_bh(&session->frwd_lock);
3180         if (is_leading)
3181                 session->leadconn = conn;
3182         spin_unlock_bh(&session->frwd_lock);
3183
3184         /*
3185          * Unblock xmitworker(), Login Phase will pass through.
3186          */
3187         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
3188         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
3189         return 0;
3190 }
3191 EXPORT_SYMBOL_GPL(iscsi_conn_bind);
3192
3193 int iscsi_switch_str_param(char **param, char *new_val_buf)
3194 {
3195         char *new_val;
3196
3197         if (*param) {
3198                 if (!strcmp(*param, new_val_buf))
3199                         return 0;
3200         }
3201
3202         new_val = kstrdup(new_val_buf, GFP_NOIO);
3203         if (!new_val)
3204                 return -ENOMEM;
3205
3206         kfree(*param);
3207         *param = new_val;
3208         return 0;
3209 }
3210 EXPORT_SYMBOL_GPL(iscsi_switch_str_param);
3211
3212 int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
3213                     enum iscsi_param param, char *buf, int buflen)
3214 {
3215         struct iscsi_conn *conn = cls_conn->dd_data;
3216         struct iscsi_session *session = conn->session;
3217         int val;
3218
3219         switch(param) {
3220         case ISCSI_PARAM_FAST_ABORT:
3221                 sscanf(buf, "%d", &session->fast_abort);
3222                 break;
3223         case ISCSI_PARAM_ABORT_TMO:
3224                 sscanf(buf, "%d", &session->abort_timeout);
3225                 break;
3226         case ISCSI_PARAM_LU_RESET_TMO:
3227                 sscanf(buf, "%d", &session->lu_reset_timeout);
3228                 break;
3229         case ISCSI_PARAM_TGT_RESET_TMO:
3230                 sscanf(buf, "%d", &session->tgt_reset_timeout);
3231                 break;
3232         case ISCSI_PARAM_PING_TMO:
3233                 sscanf(buf, "%d", &conn->ping_timeout);
3234                 break;
3235         case ISCSI_PARAM_RECV_TMO:
3236                 sscanf(buf, "%d", &conn->recv_timeout);
3237                 break;
3238         case ISCSI_PARAM_MAX_RECV_DLENGTH:
3239                 sscanf(buf, "%d", &conn->max_recv_dlength);
3240                 break;
3241         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3242                 sscanf(buf, "%d", &conn->max_xmit_dlength);
3243                 break;
3244         case ISCSI_PARAM_HDRDGST_EN:
3245                 sscanf(buf, "%d", &conn->hdrdgst_en);
3246                 break;
3247         case ISCSI_PARAM_DATADGST_EN:
3248                 sscanf(buf, "%d", &conn->datadgst_en);
3249                 break;
3250         case ISCSI_PARAM_INITIAL_R2T_EN:
3251                 sscanf(buf, "%d", &session->initial_r2t_en);
3252                 break;
3253         case ISCSI_PARAM_MAX_R2T:
3254                 sscanf(buf, "%hu", &session->max_r2t);
3255                 break;
3256         case ISCSI_PARAM_IMM_DATA_EN:
3257                 sscanf(buf, "%d", &session->imm_data_en);
3258                 break;
3259         case ISCSI_PARAM_FIRST_BURST:
3260                 sscanf(buf, "%d", &session->first_burst);
3261                 break;
3262         case ISCSI_PARAM_MAX_BURST:
3263                 sscanf(buf, "%d", &session->max_burst);
3264                 break;
3265         case ISCSI_PARAM_PDU_INORDER_EN:
3266                 sscanf(buf, "%d", &session->pdu_inorder_en);
3267                 break;
3268         case ISCSI_PARAM_DATASEQ_INORDER_EN:
3269                 sscanf(buf, "%d", &session->dataseq_inorder_en);
3270                 break;
3271         case ISCSI_PARAM_ERL:
3272                 sscanf(buf, "%d", &session->erl);
3273                 break;
3274         case ISCSI_PARAM_EXP_STATSN:
3275                 sscanf(buf, "%u", &conn->exp_statsn);
3276                 break;
3277         case ISCSI_PARAM_USERNAME:
3278                 return iscsi_switch_str_param(&session->username, buf);
3279         case ISCSI_PARAM_USERNAME_IN:
3280                 return iscsi_switch_str_param(&session->username_in, buf);
3281         case ISCSI_PARAM_PASSWORD:
3282                 return iscsi_switch_str_param(&session->password, buf);
3283         case ISCSI_PARAM_PASSWORD_IN:
3284                 return iscsi_switch_str_param(&session->password_in, buf);
3285         case ISCSI_PARAM_TARGET_NAME:
3286                 return iscsi_switch_str_param(&session->targetname, buf);
3287         case ISCSI_PARAM_TARGET_ALIAS:
3288                 return iscsi_switch_str_param(&session->targetalias, buf);
3289         case ISCSI_PARAM_TPGT:
3290                 sscanf(buf, "%d", &session->tpgt);
3291                 break;
3292         case ISCSI_PARAM_PERSISTENT_PORT:
3293                 sscanf(buf, "%d", &conn->persistent_port);
3294                 break;
3295         case ISCSI_PARAM_PERSISTENT_ADDRESS:
3296                 return iscsi_switch_str_param(&conn->persistent_address, buf);
3297         case ISCSI_PARAM_IFACE_NAME:
3298                 return iscsi_switch_str_param(&session->ifacename, buf);
3299         case ISCSI_PARAM_INITIATOR_NAME:
3300                 return iscsi_switch_str_param(&session->initiatorname, buf);
3301         case ISCSI_PARAM_BOOT_ROOT:
3302                 return iscsi_switch_str_param(&session->boot_root, buf);
3303         case ISCSI_PARAM_BOOT_NIC:
3304                 return iscsi_switch_str_param(&session->boot_nic, buf);
3305         case ISCSI_PARAM_BOOT_TARGET:
3306                 return iscsi_switch_str_param(&session->boot_target, buf);
3307         case ISCSI_PARAM_PORTAL_TYPE:
3308                 return iscsi_switch_str_param(&session->portal_type, buf);
3309         case ISCSI_PARAM_DISCOVERY_PARENT_TYPE:
3310                 return iscsi_switch_str_param(&session->discovery_parent_type,
3311                                               buf);
3312         case ISCSI_PARAM_DISCOVERY_SESS:
3313                 sscanf(buf, "%d", &val);
3314                 session->discovery_sess = !!val;
3315                 break;
3316         case ISCSI_PARAM_LOCAL_IPADDR:
3317                 return iscsi_switch_str_param(&conn->local_ipaddr, buf);
3318         default:
3319                 return -ENOSYS;
3320         }
3321
3322         return 0;
3323 }
3324 EXPORT_SYMBOL_GPL(iscsi_set_param);
3325
3326 int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
3327                             enum iscsi_param param, char *buf)
3328 {
3329         struct iscsi_session *session = cls_session->dd_data;
3330         int len;
3331
3332         switch(param) {
3333         case ISCSI_PARAM_FAST_ABORT:
3334                 len = sprintf(buf, "%d\n", session->fast_abort);
3335                 break;
3336         case ISCSI_PARAM_ABORT_TMO:
3337                 len = sprintf(buf, "%d\n", session->abort_timeout);
3338                 break;
3339         case ISCSI_PARAM_LU_RESET_TMO:
3340                 len = sprintf(buf, "%d\n", session->lu_reset_timeout);
3341                 break;
3342         case ISCSI_PARAM_TGT_RESET_TMO:
3343                 len = sprintf(buf, "%d\n", session->tgt_reset_timeout);
3344                 break;
3345         case ISCSI_PARAM_INITIAL_R2T_EN:
3346                 len = sprintf(buf, "%d\n", session->initial_r2t_en);
3347                 break;
3348         case ISCSI_PARAM_MAX_R2T:
3349                 len = sprintf(buf, "%hu\n", session->max_r2t);
3350                 break;
3351         case ISCSI_PARAM_IMM_DATA_EN:
3352                 len = sprintf(buf, "%d\n", session->imm_data_en);
3353                 break;
3354         case ISCSI_PARAM_FIRST_BURST:
3355                 len = sprintf(buf, "%u\n", session->first_burst);
3356                 break;
3357         case ISCSI_PARAM_MAX_BURST:
3358                 len = sprintf(buf, "%u\n", session->max_burst);
3359                 break;
3360         case ISCSI_PARAM_PDU_INORDER_EN:
3361                 len = sprintf(buf, "%d\n", session->pdu_inorder_en);
3362                 break;
3363         case ISCSI_PARAM_DATASEQ_INORDER_EN:
3364                 len = sprintf(buf, "%d\n", session->dataseq_inorder_en);
3365                 break;
3366         case ISCSI_PARAM_DEF_TASKMGMT_TMO:
3367                 len = sprintf(buf, "%d\n", session->def_taskmgmt_tmo);
3368                 break;
3369         case ISCSI_PARAM_ERL:
3370                 len = sprintf(buf, "%d\n", session->erl);
3371                 break;
3372         case ISCSI_PARAM_TARGET_NAME:
3373                 len = sprintf(buf, "%s\n", session->targetname);
3374                 break;
3375         case ISCSI_PARAM_TARGET_ALIAS:
3376                 len = sprintf(buf, "%s\n", session->targetalias);
3377                 break;
3378         case ISCSI_PARAM_TPGT:
3379                 len = sprintf(buf, "%d\n", session->tpgt);
3380                 break;
3381         case ISCSI_PARAM_USERNAME:
3382                 len = sprintf(buf, "%s\n", session->username);
3383                 break;
3384         case ISCSI_PARAM_USERNAME_IN:
3385                 len = sprintf(buf, "%s\n", session->username_in);
3386                 break;
3387         case ISCSI_PARAM_PASSWORD:
3388                 len = sprintf(buf, "%s\n", session->password);
3389                 break;
3390         case ISCSI_PARAM_PASSWORD_IN:
3391                 len = sprintf(buf, "%s\n", session->password_in);
3392                 break;
3393         case ISCSI_PARAM_IFACE_NAME:
3394                 len = sprintf(buf, "%s\n", session->ifacename);
3395                 break;
3396         case ISCSI_PARAM_INITIATOR_NAME:
3397                 len = sprintf(buf, "%s\n", session->initiatorname);
3398                 break;
3399         case ISCSI_PARAM_BOOT_ROOT:
3400                 len = sprintf(buf, "%s\n", session->boot_root);
3401                 break;
3402         case ISCSI_PARAM_BOOT_NIC:
3403                 len = sprintf(buf, "%s\n", session->boot_nic);
3404                 break;
3405         case ISCSI_PARAM_BOOT_TARGET:
3406                 len = sprintf(buf, "%s\n", session->boot_target);
3407                 break;
3408         case ISCSI_PARAM_AUTO_SND_TGT_DISABLE:
3409                 len = sprintf(buf, "%u\n", session->auto_snd_tgt_disable);
3410                 break;
3411         case ISCSI_PARAM_DISCOVERY_SESS:
3412                 len = sprintf(buf, "%u\n", session->discovery_sess);
3413                 break;
3414         case ISCSI_PARAM_PORTAL_TYPE:
3415                 len = sprintf(buf, "%s\n", session->portal_type);
3416                 break;
3417         case ISCSI_PARAM_CHAP_AUTH_EN:
3418                 len = sprintf(buf, "%u\n", session->chap_auth_en);
3419                 break;
3420         case ISCSI_PARAM_DISCOVERY_LOGOUT_EN:
3421                 len = sprintf(buf, "%u\n", session->discovery_logout_en);
3422                 break;
3423         case ISCSI_PARAM_BIDI_CHAP_EN:
3424                 len = sprintf(buf, "%u\n", session->bidi_chap_en);
3425                 break;
3426         case ISCSI_PARAM_DISCOVERY_AUTH_OPTIONAL:
3427                 len = sprintf(buf, "%u\n", session->discovery_auth_optional);
3428                 break;
3429         case ISCSI_PARAM_DEF_TIME2WAIT:
3430                 len = sprintf(buf, "%d\n", session->time2wait);
3431                 break;
3432         case ISCSI_PARAM_DEF_TIME2RETAIN:
3433                 len = sprintf(buf, "%d\n", session->time2retain);
3434                 break;
3435         case ISCSI_PARAM_TSID:
3436                 len = sprintf(buf, "%u\n", session->tsid);
3437                 break;
3438         case ISCSI_PARAM_ISID:
3439                 len = sprintf(buf, "%02x%02x%02x%02x%02x%02x\n",
3440                               session->isid[0], session->isid[1],
3441                               session->isid[2], session->isid[3],
3442                               session->isid[4], session->isid[5]);
3443                 break;
3444         case ISCSI_PARAM_DISCOVERY_PARENT_IDX:
3445                 len = sprintf(buf, "%u\n", session->discovery_parent_idx);
3446                 break;
3447         case ISCSI_PARAM_DISCOVERY_PARENT_TYPE:
3448                 if (session->discovery_parent_type)
3449                         len = sprintf(buf, "%s\n",
3450                                       session->discovery_parent_type);
3451                 else
3452                         len = sprintf(buf, "\n");
3453                 break;
3454         default:
3455                 return -ENOSYS;
3456         }
3457
3458         return len;
3459 }
3460 EXPORT_SYMBOL_GPL(iscsi_session_get_param);
3461
3462 int iscsi_conn_get_addr_param(struct sockaddr_storage *addr,
3463                               enum iscsi_param param, char *buf)
3464 {
3465         struct sockaddr_in6 *sin6 = NULL;
3466         struct sockaddr_in *sin = NULL;
3467         int len;
3468
3469         switch (addr->ss_family) {
3470         case AF_INET:
3471                 sin = (struct sockaddr_in *)addr;
3472                 break;
3473         case AF_INET6:
3474                 sin6 = (struct sockaddr_in6 *)addr;
3475                 break;
3476         default:
3477                 return -EINVAL;
3478         }
3479
3480         switch (param) {
3481         case ISCSI_PARAM_CONN_ADDRESS:
3482         case ISCSI_HOST_PARAM_IPADDRESS:
3483                 if (sin)
3484                         len = sprintf(buf, "%pI4\n", &sin->sin_addr.s_addr);
3485                 else
3486                         len = sprintf(buf, "%pI6\n", &sin6->sin6_addr);
3487                 break;
3488         case ISCSI_PARAM_CONN_PORT:
3489         case ISCSI_PARAM_LOCAL_PORT:
3490                 if (sin)
3491                         len = sprintf(buf, "%hu\n", be16_to_cpu(sin->sin_port));
3492                 else
3493                         len = sprintf(buf, "%hu\n",
3494                                       be16_to_cpu(sin6->sin6_port));
3495                 break;
3496         default:
3497                 return -EINVAL;
3498         }
3499
3500         return len;
3501 }
3502 EXPORT_SYMBOL_GPL(iscsi_conn_get_addr_param);
3503
3504 int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
3505                          enum iscsi_param param, char *buf)
3506 {
3507         struct iscsi_conn *conn = cls_conn->dd_data;
3508         int len;
3509
3510         switch(param) {
3511         case ISCSI_PARAM_PING_TMO:
3512                 len = sprintf(buf, "%u\n", conn->ping_timeout);
3513                 break;
3514         case ISCSI_PARAM_RECV_TMO:
3515                 len = sprintf(buf, "%u\n", conn->recv_timeout);
3516                 break;
3517         case ISCSI_PARAM_MAX_RECV_DLENGTH:
3518                 len = sprintf(buf, "%u\n", conn->max_recv_dlength);
3519                 break;
3520         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3521                 len = sprintf(buf, "%u\n", conn->max_xmit_dlength);
3522                 break;
3523         case ISCSI_PARAM_HDRDGST_EN:
3524                 len = sprintf(buf, "%d\n", conn->hdrdgst_en);
3525                 break;
3526         case ISCSI_PARAM_DATADGST_EN:
3527                 len = sprintf(buf, "%d\n", conn->datadgst_en);
3528                 break;
3529         case ISCSI_PARAM_IFMARKER_EN:
3530                 len = sprintf(buf, "%d\n", conn->ifmarker_en);
3531                 break;
3532         case ISCSI_PARAM_OFMARKER_EN:
3533                 len = sprintf(buf, "%d\n", conn->ofmarker_en);
3534                 break;
3535         case ISCSI_PARAM_EXP_STATSN:
3536                 len = sprintf(buf, "%u\n", conn->exp_statsn);
3537                 break;
3538         case ISCSI_PARAM_PERSISTENT_PORT:
3539                 len = sprintf(buf, "%d\n", conn->persistent_port);
3540                 break;
3541         case ISCSI_PARAM_PERSISTENT_ADDRESS:
3542                 len = sprintf(buf, "%s\n", conn->persistent_address);
3543                 break;
3544         case ISCSI_PARAM_STATSN:
3545                 len = sprintf(buf, "%u\n", conn->statsn);
3546                 break;
3547         case ISCSI_PARAM_MAX_SEGMENT_SIZE:
3548                 len = sprintf(buf, "%u\n", conn->max_segment_size);
3549                 break;
3550         case ISCSI_PARAM_KEEPALIVE_TMO:
3551                 len = sprintf(buf, "%u\n", conn->keepalive_tmo);
3552                 break;
3553         case ISCSI_PARAM_LOCAL_PORT:
3554                 len = sprintf(buf, "%u\n", conn->local_port);
3555                 break;
3556         case ISCSI_PARAM_TCP_TIMESTAMP_STAT:
3557                 len = sprintf(buf, "%u\n", conn->tcp_timestamp_stat);
3558                 break;
3559         case ISCSI_PARAM_TCP_NAGLE_DISABLE:
3560                 len = sprintf(buf, "%u\n", conn->tcp_nagle_disable);
3561                 break;
3562         case ISCSI_PARAM_TCP_WSF_DISABLE:
3563                 len = sprintf(buf, "%u\n", conn->tcp_wsf_disable);
3564                 break;
3565         case ISCSI_PARAM_TCP_TIMER_SCALE:
3566                 len = sprintf(buf, "%u\n", conn->tcp_timer_scale);
3567                 break;
3568         case ISCSI_PARAM_TCP_TIMESTAMP_EN:
3569                 len = sprintf(buf, "%u\n", conn->tcp_timestamp_en);
3570                 break;
3571         case ISCSI_PARAM_IP_FRAGMENT_DISABLE:
3572                 len = sprintf(buf, "%u\n", conn->fragment_disable);
3573                 break;
3574         case ISCSI_PARAM_IPV4_TOS:
3575                 len = sprintf(buf, "%u\n", conn->ipv4_tos);
3576                 break;
3577         case ISCSI_PARAM_IPV6_TC:
3578                 len = sprintf(buf, "%u\n", conn->ipv6_traffic_class);
3579                 break;
3580         case ISCSI_PARAM_IPV6_FLOW_LABEL:
3581                 len = sprintf(buf, "%u\n", conn->ipv6_flow_label);
3582                 break;
3583         case ISCSI_PARAM_IS_FW_ASSIGNED_IPV6:
3584                 len = sprintf(buf, "%u\n", conn->is_fw_assigned_ipv6);
3585                 break;
3586         case ISCSI_PARAM_TCP_XMIT_WSF:
3587                 len = sprintf(buf, "%u\n", conn->tcp_xmit_wsf);
3588                 break;
3589         case ISCSI_PARAM_TCP_RECV_WSF:
3590                 len = sprintf(buf, "%u\n", conn->tcp_recv_wsf);
3591                 break;
3592         case ISCSI_PARAM_LOCAL_IPADDR:
3593                 len = sprintf(buf, "%s\n", conn->local_ipaddr);
3594                 break;
3595         default:
3596                 return -ENOSYS;
3597         }
3598
3599         return len;
3600 }
3601 EXPORT_SYMBOL_GPL(iscsi_conn_get_param);
3602
3603 int iscsi_host_get_param(struct Scsi_Host *shost, enum iscsi_host_param param,
3604                          char *buf)
3605 {
3606         struct iscsi_host *ihost = shost_priv(shost);
3607         int len;
3608
3609         switch (param) {
3610         case ISCSI_HOST_PARAM_NETDEV_NAME:
3611                 len = sprintf(buf, "%s\n", ihost->netdev);
3612                 break;
3613         case ISCSI_HOST_PARAM_HWADDRESS:
3614                 len = sprintf(buf, "%s\n", ihost->hwaddress);
3615                 break;
3616         case ISCSI_HOST_PARAM_INITIATOR_NAME:
3617                 len = sprintf(buf, "%s\n", ihost->initiatorname);
3618                 break;
3619         default:
3620                 return -ENOSYS;
3621         }
3622
3623         return len;
3624 }
3625 EXPORT_SYMBOL_GPL(iscsi_host_get_param);
3626
3627 int iscsi_host_set_param(struct Scsi_Host *shost, enum iscsi_host_param param,
3628                          char *buf, int buflen)
3629 {
3630         struct iscsi_host *ihost = shost_priv(shost);
3631
3632         switch (param) {
3633         case ISCSI_HOST_PARAM_NETDEV_NAME:
3634                 return iscsi_switch_str_param(&ihost->netdev, buf);
3635         case ISCSI_HOST_PARAM_HWADDRESS:
3636                 return iscsi_switch_str_param(&ihost->hwaddress, buf);
3637         case ISCSI_HOST_PARAM_INITIATOR_NAME:
3638                 return iscsi_switch_str_param(&ihost->initiatorname, buf);
3639         default:
3640                 return -ENOSYS;
3641         }
3642
3643         return 0;
3644 }
3645 EXPORT_SYMBOL_GPL(iscsi_host_set_param);
3646
3647 MODULE_AUTHOR("Mike Christie");
3648 MODULE_DESCRIPTION("iSCSI library functions");
3649 MODULE_LICENSE("GPL");