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 [email protected]
  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         if (READ_ONCE(conn->ping_task) == task)
 527                 WRITE_ONCE(conn->ping_task, NULL);
 528
 529         /* release get from queueing */
 530         __iscsi_put_task(task);
 531 }
 532
 533 /**
 534  * iscsi_complete_scsi_task - finish scsi task normally
 535  * @task: iscsi task for scsi cmd
 536  * @exp_cmdsn: expected cmd sn in cpu format
 537  * @max_cmdsn: max cmd sn in cpu format
 538  *
 539  * This is used when drivers do not need or cannot perform
 540  * lower level pdu processing.
 541  *
 542  * Called with session back_lock
 543  */
 544 void iscsi_complete_scsi_task(struct iscsi_task *task,
 545                               uint32_t exp_cmdsn, uint32_t max_cmdsn)
 546 {
 547         struct iscsi_conn *conn = task->conn;
 548
 549         ISCSI_DBG_SESSION(conn->session, "[itt 0x%x]\n", task->itt);
 550
 551         conn->last_recv = jiffies;
 552         __iscsi_update_cmdsn(conn->session, exp_cmdsn, max_cmdsn);
 553         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 554 }
 555 EXPORT_SYMBOL_GPL(iscsi_complete_scsi_task);
 556
 557 /*
 558  * Must be called with back and frwd lock
 559  */
 560 static bool cleanup_queued_task(struct iscsi_task *task)
 561 {
 562         struct iscsi_conn *conn = task->conn;
 563         bool early_complete = false;
 564
 565         /* Bad target might have completed task while it was still running */
 566         if (task->state == ISCSI_TASK_COMPLETED)
 567                 early_complete = true;
 568
 569         if (!list_empty(&task->running)) {
 570                 list_del_init(&task->running);
 571                 /*
 572                  * If it's on a list but still running, this could be from
 573                  * a bad target sending a rsp early, cleanup from a TMF, or
 574                  * session recovery.
 575                  */
 576                 if (task->state == ISCSI_TASK_RUNNING ||
 577                     task->state == ISCSI_TASK_COMPLETED)
 578                         __iscsi_put_task(task);
 579         }
 580
 581         if (conn->task == task) {
 582                 conn->task = NULL;
 583                 __iscsi_put_task(task);
 584         }
 585
 586         return early_complete;
 587 }
 588
 589 /*
 590  * session frwd lock must be held and if not called for a task that is still
 591  * pending or from the xmit thread, then xmit thread must be suspended
 592  */
 593 static void fail_scsi_task(struct iscsi_task *task, int err)
 594 {
 595         struct iscsi_conn *conn = task->conn;
 596         struct scsi_cmnd *sc;
 597         int state;
 598
 599         spin_lock_bh(&conn->session->back_lock);
 600         if (cleanup_queued_task(task)) {
 601                 spin_unlock_bh(&conn->session->back_lock);
 602                 return;
 603         }
 604
 605         if (task->state == ISCSI_TASK_PENDING) {
 606                 /*
 607                  * cmd never made it to the xmit thread, so we should not count
 608                  * the cmd in the sequencing
 609                  */
 610                 conn->session->queued_cmdsn--;
 611                 /* it was never sent so just complete like normal */
 612                 state = ISCSI_TASK_COMPLETED;
 613         } else if (err == DID_TRANSPORT_DISRUPTED)
 614                 state = ISCSI_TASK_ABRT_SESS_RECOV;
 615         else
 616                 state = ISCSI_TASK_ABRT_TMF;
 617
 618         sc = task->sc;
 619         sc->result = err << 16;
 620         scsi_set_resid(sc, scsi_bufflen(sc));
 621         iscsi_complete_task(task, state);
 622         spin_unlock_bh(&conn->session->back_lock);
 623 }
 624
 625 static int iscsi_prep_mgmt_task(struct iscsi_conn *conn,
 626                                 struct iscsi_task *task)
 627 {
 628         struct iscsi_session *session = conn->session;
 629         struct iscsi_hdr *hdr = task->hdr;
 630         struct iscsi_nopout *nop = (struct iscsi_nopout *)hdr;
 631         uint8_t opcode = hdr->opcode & ISCSI_OPCODE_MASK;
 632
 633         if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
 634                 return -ENOTCONN;
 635
 636         if (opcode != ISCSI_OP_LOGIN && opcode != ISCSI_OP_TEXT)
 637                 nop->exp_statsn = cpu_to_be32(conn->exp_statsn);
 638         /*
 639          * pre-format CmdSN for outgoing PDU.
 640          */
 641         nop->cmdsn = cpu_to_be32(session->cmdsn);
 642         if (hdr->itt != RESERVED_ITT) {
 643                 /*
 644                  * TODO: We always use immediate for normal session pdus.
 645                  * If we start to send tmfs or nops as non-immediate then
 646                  * we should start checking the cmdsn numbers for mgmt tasks.
 647                  *
 648                  * During discovery sessions iscsid sends TEXT as non immediate,
 649                  * but we always only send one PDU at a time.
 650                  */
 651                 if (conn->c_stage == ISCSI_CONN_STARTED &&
 652                     !(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
 653                         session->queued_cmdsn++;
 654                         session->cmdsn++;
 655                 }
 656         }
 657
 658         if (session->tt->init_task && session->tt->init_task(task))
 659                 return -EIO;
 660
 661         if ((hdr->opcode & ISCSI_OPCODE_MASK) == ISCSI_OP_LOGOUT)
 662                 session->state = ISCSI_STATE_LOGGING_OUT;
 663
 664         task->state = ISCSI_TASK_RUNNING;
 665         ISCSI_DBG_SESSION(session, "mgmtpdu [op 0x%x hdr->itt 0x%x "
 666                           "datalen %d]\n", hdr->opcode & ISCSI_OPCODE_MASK,
 667                           hdr->itt, task->data_count);
 668         return 0;
 669 }
 670
 671 static struct iscsi_task *
 672 __iscsi_conn_send_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 673                       char *data, uint32_t data_size)
 674 {
 675         struct iscsi_session *session = conn->session;
 676         struct iscsi_host *ihost = shost_priv(session->host);
 677         uint8_t opcode = hdr->opcode & ISCSI_OPCODE_MASK;
 678         struct iscsi_task *task;
 679         itt_t itt;
 680
 681         if (session->state == ISCSI_STATE_TERMINATE)
 682                 return NULL;
 683
 684         if (opcode == ISCSI_OP_LOGIN || opcode == ISCSI_OP_TEXT) {
 685                 /*
 686                  * Login and Text are sent serially, in
 687                  * request-followed-by-response sequence.
 688                  * Same task can be used. Same ITT must be used.
 689                  * Note that login_task is preallocated at conn_create().
 690                  */
 691                 if (conn->login_task->state != ISCSI_TASK_FREE) {
 692                         iscsi_conn_printk(KERN_ERR, conn, "Login/Text in "
 693                                           "progress. Cannot start new task.\n");
 694                         return NULL;
 695                 }
 696
 697                 if (data_size > ISCSI_DEF_MAX_RECV_SEG_LEN) {
 698                         iscsi_conn_printk(KERN_ERR, conn, "Invalid buffer len of %u for login task. Max len is %u\n", data_size, ISCSI_DEF_MAX_RECV_SEG_LEN);
 699                         return NULL;
 700                 }
 701
 702                 task = conn->login_task;
 703         } else {
 704                 if (session->state != ISCSI_STATE_LOGGED_IN)
 705                         return NULL;
 706
 707                 if (data_size != 0) {
 708                         iscsi_conn_printk(KERN_ERR, conn, "Can not send data buffer of len %u for op 0x%x\n", data_size, opcode);
 709                         return NULL;
 710                 }
 711
 712                 BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
 713                 BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);
 714
 715                 if (!kfifo_out(&session->cmdpool.queue,
 716                                  (void*)&task, sizeof(void*)))
 717                         return NULL;
 718         }
 719         /*
 720          * released in complete pdu for task we expect a response for, and
 721          * released by the lld when it has transmitted the task for
 722          * pdus we do not expect a response for.
 723          */
 724         refcount_set(&task->refcount, 1);
 725         task->conn = conn;
 726         task->sc = NULL;
 727         INIT_LIST_HEAD(&task->running);
 728         task->state = ISCSI_TASK_PENDING;
 729
 730         if (data_size) {
 731                 memcpy(task->data, data, data_size);
 732                 task->data_count = data_size;
 733         } else
 734                 task->data_count = 0;
 735
 736         if (conn->session->tt->alloc_pdu) {
 737                 if (conn->session->tt->alloc_pdu(task, hdr->opcode)) {
 738                         iscsi_conn_printk(KERN_ERR, conn, "Could not allocate "
 739                                          "pdu for mgmt task.\n");
 740                         goto free_task;
 741                 }
 742         }
 743
 744         itt = task->hdr->itt;
 745         task->hdr_len = sizeof(struct iscsi_hdr);
 746         memcpy(task->hdr, hdr, sizeof(struct iscsi_hdr));
 747
 748         if (hdr->itt != RESERVED_ITT) {
 749                 if (session->tt->parse_pdu_itt)
 750                         task->hdr->itt = itt;
 751                 else
 752                         task->hdr->itt = build_itt(task->itt,
 753                                                    task->conn->session->age);
 754         }
 755
 756         if (unlikely(READ_ONCE(conn->ping_task) == INVALID_SCSI_TASK))
 757                 WRITE_ONCE(conn->ping_task, task);
 758
 759         if (!ihost->workq) {
 760                 if (iscsi_prep_mgmt_task(conn, task))
 761                         goto free_task;
 762
 763                 if (session->tt->xmit_task(task))
 764                         goto free_task;
 765         } else {
 766                 list_add_tail(&task->running, &conn->mgmtqueue);
 767                 iscsi_conn_queue_work(conn);
 768         }
 769
 770         return task;
 771
 772 free_task:
 773         /* regular RX path uses back_lock */
 774         spin_lock(&session->back_lock);
 775         __iscsi_put_task(task);
 776         spin_unlock(&session->back_lock);
 777         return NULL;
 778 }
 779
 780 int iscsi_conn_send_pdu(struct iscsi_cls_conn *cls_conn, struct iscsi_hdr *hdr,
 781                         char *data, uint32_t data_size)
 782 {
 783         struct iscsi_conn *conn = cls_conn->dd_data;
 784         struct iscsi_session *session = conn->session;
 785         int err = 0;
 786
 787         spin_lock_bh(&session->frwd_lock);
 788         if (!__iscsi_conn_send_pdu(conn, hdr, data, data_size))
 789                 err = -EPERM;
 790         spin_unlock_bh(&session->frwd_lock);
 791         return err;
 792 }
 793 EXPORT_SYMBOL_GPL(iscsi_conn_send_pdu);
 794
 795 /**
 796  * iscsi_scsi_cmd_rsp - SCSI Command Response processing
 797  * @conn: iscsi connection
 798  * @hdr: iscsi header
 799  * @task: scsi command task
 800  * @data: cmd data buffer
 801  * @datalen: len of buffer
 802  *
 803  * iscsi_cmd_rsp sets up the scsi_cmnd fields based on the PDU and
 804  * then completes the command and task. called under back_lock
 805  **/
 806 static void iscsi_scsi_cmd_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 807                                struct iscsi_task *task, char *data,
 808                                int datalen)
 809 {
 810         struct iscsi_scsi_rsp *rhdr = (struct iscsi_scsi_rsp *)hdr;
 811         struct iscsi_session *session = conn->session;
 812         struct scsi_cmnd *sc = task->sc;
 813
 814         iscsi_update_cmdsn(session, (struct iscsi_nopin*)rhdr);
 815         conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 816
 817         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 818
 819         if (task->protected) {
 820                 sector_t sector;
 821                 u8 ascq;
 822
 823                 /**
 824                  * Transports that didn't implement check_protection
 825                  * callback but still published T10-PI support to scsi-mid
 826                  * deserve this BUG_ON.
 827                  **/
 828                 BUG_ON(!session->tt->check_protection);
 829
 830                 ascq = session->tt->check_protection(task, &sector);
 831                 if (ascq) {
 832                         sc->result = DRIVER_SENSE << 24 |
 833                                      SAM_STAT_CHECK_CONDITION;
 834                         scsi_build_sense_buffer(1, sc->sense_buffer,
 835                                                 ILLEGAL_REQUEST, 0x10, ascq);
 836                         scsi_set_sense_information(sc->sense_buffer,
 837                                                    SCSI_SENSE_BUFFERSIZE,
 838                                                    sector);
 839                         goto out;
 840                 }
 841         }
 842
 843         if (rhdr->response != ISCSI_STATUS_CMD_COMPLETED) {
 844                 sc->result = DID_ERROR << 16;
 845                 goto out;
 846         }
 847
 848         if (rhdr->cmd_status == SAM_STAT_CHECK_CONDITION) {
 849                 uint16_t senselen;
 850
 851                 if (datalen < 2) {
 852 invalid_datalen:
 853                         iscsi_conn_printk(KERN_ERR,  conn,
 854                                          "Got CHECK_CONDITION but invalid data "
 855                                          "buffer size of %d\n", datalen);
 856                         sc->result = DID_BAD_TARGET << 16;
 857                         goto out;
 858                 }
 859
 860                 senselen = get_unaligned_be16(data);
 861                 if (datalen < senselen)
 862                         goto invalid_datalen;
 863
 864                 memcpy(sc->sense_buffer, data + 2,
 865                        min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
 866                 ISCSI_DBG_SESSION(session, "copied %d bytes of sense\n",
 867                                   min_t(uint16_t, senselen,
 868                                   SCSI_SENSE_BUFFERSIZE));
 869         }
 870
 871         if (rhdr->flags & (ISCSI_FLAG_CMD_BIDI_UNDERFLOW |
 872                            ISCSI_FLAG_CMD_BIDI_OVERFLOW)) {
 873                 sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 874         }
 875
 876         if (rhdr->flags & (ISCSI_FLAG_CMD_UNDERFLOW |
 877                            ISCSI_FLAG_CMD_OVERFLOW)) {
 878                 int res_count = be32_to_cpu(rhdr->residual_count);
 879
 880                 if (res_count > 0 &&
 881                     (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
 882                      res_count <= scsi_bufflen(sc)))
 883                         /* write side for bidi or uni-io set_resid */
 884                         scsi_set_resid(sc, res_count);
 885                 else
 886                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 887         }
 888 out:
 889         ISCSI_DBG_SESSION(session, "cmd rsp done [sc %p res %d itt 0x%x]\n",
 890                           sc, sc->result, task->itt);
 891         conn->scsirsp_pdus_cnt++;
 892         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 893 }
 894
 895 /**
 896  * iscsi_data_in_rsp - SCSI Data-In Response processing
 897  * @conn: iscsi connection
 898  * @hdr:  iscsi pdu
 899  * @task: scsi command task
 900  *
 901  * iscsi_data_in_rsp sets up the scsi_cmnd fields based on the data received
 902  * then completes the command and task. called under back_lock
 903  **/
 904 static void
 905 iscsi_data_in_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 906                   struct iscsi_task *task)
 907 {
 908         struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)hdr;
 909         struct scsi_cmnd *sc = task->sc;
 910
 911         if (!(rhdr->flags & ISCSI_FLAG_DATA_STATUS))
 912                 return;
 913
 914         iscsi_update_cmdsn(conn->session, (struct iscsi_nopin *)hdr);
 915         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 916         conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 917         if (rhdr->flags & (ISCSI_FLAG_DATA_UNDERFLOW |
 918                            ISCSI_FLAG_DATA_OVERFLOW)) {
 919                 int res_count = be32_to_cpu(rhdr->residual_count);
 920
 921                 if (res_count > 0 &&
 922                     (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
 923                      res_count <= sc->sdb.length))
 924                         scsi_set_resid(sc, res_count);
 925                 else
 926                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 927         }
 928
 929         ISCSI_DBG_SESSION(conn->session, "data in with status done "
 930                           "[sc %p res %d itt 0x%x]\n",
 931                           sc, sc->result, task->itt);
 932         conn->scsirsp_pdus_cnt++;
 933         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 934 }
 935
 936 static void iscsi_tmf_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
 937 {
 938         struct iscsi_tm_rsp *tmf = (struct iscsi_tm_rsp *)hdr;
 939
 940         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 941         conn->tmfrsp_pdus_cnt++;
 942
 943         if (conn->tmf_state != TMF_QUEUED)
 944                 return;
 945
 946         if (tmf->response == ISCSI_TMF_RSP_COMPLETE)
 947                 conn->tmf_state = TMF_SUCCESS;
 948         else if (tmf->response == ISCSI_TMF_RSP_NO_TASK)
 949                 conn->tmf_state = TMF_NOT_FOUND;
 950         else
 951                 conn->tmf_state = TMF_FAILED;
 952         wake_up(&conn->ehwait);
 953 }
 954
 955 static int iscsi_send_nopout(struct iscsi_conn *conn, struct iscsi_nopin *rhdr)
 956 {
 957         struct iscsi_nopout hdr;
 958         struct iscsi_task *task;
 959
 960         if (!rhdr) {
 961                 if (READ_ONCE(conn->ping_task))
 962                         return -EINVAL;
 963                 WRITE_ONCE(conn->ping_task, INVALID_SCSI_TASK);
 964         }
 965
 966         memset(&hdr, 0, sizeof(struct iscsi_nopout));
 967         hdr.opcode = ISCSI_OP_NOOP_OUT | ISCSI_OP_IMMEDIATE;
 968         hdr.flags = ISCSI_FLAG_CMD_FINAL;
 969
 970         if (rhdr) {
 971                 hdr.lun = rhdr->lun;
 972                 hdr.ttt = rhdr->ttt;
 973                 hdr.itt = RESERVED_ITT;
 974         } else
 975                 hdr.ttt = RESERVED_ITT;
 976
 977         task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)&hdr, NULL, 0);
 978         if (!task) {
 979                 if (!rhdr)
 980                         WRITE_ONCE(conn->ping_task, NULL);
 981                 iscsi_conn_printk(KERN_ERR, conn, "Could not send nopout\n");
 982                 return -EIO;
 983         } else if (!rhdr) {
 984                 /* only track our nops */
 985                 conn->last_ping = jiffies;
 986         }
 987
 988         return 0;
 989 }
 990
 991 /**
 992  * iscsi_nop_out_rsp - SCSI NOP Response processing
 993  * @task: scsi command task
 994  * @nop: the nop structure
 995  * @data: where to put the data
 996  * @datalen: length of data
 997  *
 998  * iscsi_nop_out_rsp handles nop response from use or
 999  * from user space. called under back_lock
1000  **/
1001 static int iscsi_nop_out_rsp(struct iscsi_task *task,
1002                              struct iscsi_nopin *nop, char *data, int datalen)
1003 {
1004         struct iscsi_conn *conn = task->conn;
1005         int rc = 0;
1006
1007         if (READ_ONCE(conn->ping_task) != task) {
1008                 /*
1009                  * If this is not in response to one of our
1010                  * nops then it must be from userspace.
1011                  */
1012                 if (iscsi_recv_pdu(conn->cls_conn, (struct iscsi_hdr *)nop,
1013                                    data, datalen))
1014                         rc = ISCSI_ERR_CONN_FAILED;
1015         } else
1016                 mod_timer(&conn->transport_timer, jiffies + conn->recv_timeout);
1017         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1018         return rc;
1019 }
1020
1021 static int iscsi_handle_reject(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1022                                char *data, int datalen)
1023 {
1024         struct iscsi_reject *reject = (struct iscsi_reject *)hdr;
1025         struct iscsi_hdr rejected_pdu;
1026         int opcode, rc = 0;
1027
1028         conn->exp_statsn = be32_to_cpu(reject->statsn) + 1;
1029
1030         if (ntoh24(reject->dlength) > datalen ||
1031             ntoh24(reject->dlength) < sizeof(struct iscsi_hdr)) {
1032                 iscsi_conn_printk(KERN_ERR, conn, "Cannot handle rejected "
1033                                   "pdu. Invalid data length (pdu dlength "
1034                                   "%u, datalen %d\n", ntoh24(reject->dlength),
1035                                   datalen);
1036                 return ISCSI_ERR_PROTO;
1037         }
1038         memcpy(&rejected_pdu, data, sizeof(struct iscsi_hdr));
1039         opcode = rejected_pdu.opcode & ISCSI_OPCODE_MASK;
1040
1041         switch (reject->reason) {
1042         case ISCSI_REASON_DATA_DIGEST_ERROR:
1043                 iscsi_conn_printk(KERN_ERR, conn,
1044                                   "pdu (op 0x%x itt 0x%x) rejected "
1045                                   "due to DataDigest error.\n",
1046                                   opcode, rejected_pdu.itt);
1047                 break;
1048         case ISCSI_REASON_IMM_CMD_REJECT:
1049                 iscsi_conn_printk(KERN_ERR, conn,
1050                                   "pdu (op 0x%x itt 0x%x) rejected. Too many "
1051                                   "immediate commands.\n",
1052                                   opcode, rejected_pdu.itt);
1053                 /*
1054                  * We only send one TMF at a time so if the target could not
1055                  * handle it, then it should get fixed (RFC mandates that
1056                  * a target can handle one immediate TMF per conn).
1057                  *
1058                  * For nops-outs, we could have sent more than one if
1059                  * the target is sending us lots of nop-ins
1060                  */
1061                 if (opcode != ISCSI_OP_NOOP_OUT)
1062                         return 0;
1063
1064                 if (rejected_pdu.itt == cpu_to_be32(ISCSI_RESERVED_TAG)) {
1065                         /*
1066                          * nop-out in response to target's nop-out rejected.
1067                          * Just resend.
1068                          */
1069                         /* In RX path we are under back lock */
1070                         spin_unlock(&conn->session->back_lock);
1071                         spin_lock(&conn->session->frwd_lock);
1072                         iscsi_send_nopout(conn,
1073                                           (struct iscsi_nopin*)&rejected_pdu);
1074                         spin_unlock(&conn->session->frwd_lock);
1075                         spin_lock(&conn->session->back_lock);
1076                 } else {
1077                         struct iscsi_task *task;
1078                         /*
1079                          * Our nop as ping got dropped. We know the target
1080                          * and transport are ok so just clean up
1081                          */
1082                         task = iscsi_itt_to_task(conn, rejected_pdu.itt);
1083                         if (!task) {
1084                                 iscsi_conn_printk(KERN_ERR, conn,
1085                                                  "Invalid pdu reject. Could "
1086                                                  "not lookup rejected task.\n");
1087                                 rc = ISCSI_ERR_BAD_ITT;
1088                         } else
1089                                 rc = iscsi_nop_out_rsp(task,
1090                                         (struct iscsi_nopin*)&rejected_pdu,
1091                                         NULL, 0);
1092                 }
1093                 break;
1094         default:
1095                 iscsi_conn_printk(KERN_ERR, conn,
1096                                   "pdu (op 0x%x itt 0x%x) rejected. Reason "
1097                                   "code 0x%x\n", rejected_pdu.opcode,
1098                                   rejected_pdu.itt, reject->reason);
1099                 break;
1100         }
1101         return rc;
1102 }
1103
1104 /**
1105  * iscsi_itt_to_task - look up task by itt
1106  * @conn: iscsi connection
1107  * @itt: itt
1108  *
1109  * This should be used for mgmt tasks like login and nops, or if
1110  * the LDD's itt space does not include the session age.
1111  *
1112  * The session back_lock must be held.
1113  */
1114 struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *conn, itt_t itt)
1115 {
1116         struct iscsi_session *session = conn->session;
1117         int i;
1118
1119         if (itt == RESERVED_ITT)
1120                 return NULL;
1121
1122         if (session->tt->parse_pdu_itt)
1123                 session->tt->parse_pdu_itt(conn, itt, &i, NULL);
1124         else
1125                 i = get_itt(itt);
1126         if (i >= session->cmds_max)
1127                 return NULL;
1128
1129         return session->cmds[i];
1130 }
1131 EXPORT_SYMBOL_GPL(iscsi_itt_to_task);
1132
1133 /**
1134  * __iscsi_complete_pdu - complete pdu
1135  * @conn: iscsi conn
1136  * @hdr: iscsi header
1137  * @data: data buffer
1138  * @datalen: len of data buffer
1139  *
1140  * Completes pdu processing by freeing any resources allocated at
1141  * queuecommand or send generic. session back_lock must be held and verify
1142  * itt must have been called.
1143  */
1144 int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1145                          char *data, int datalen)
1146 {
1147         struct iscsi_session *session = conn->session;
1148         int opcode = hdr->opcode & ISCSI_OPCODE_MASK, rc = 0;
1149         struct iscsi_task *task;
1150         uint32_t itt;
1151
1152         conn->last_recv = jiffies;
1153         rc = iscsi_verify_itt(conn, hdr->itt);
1154         if (rc)
1155                 return rc;
1156
1157         if (hdr->itt != RESERVED_ITT)
1158                 itt = get_itt(hdr->itt);
1159         else
1160                 itt = ~0U;
1161
1162         ISCSI_DBG_SESSION(session, "[op 0x%x cid %d itt 0x%x len %d]\n",
1163                           opcode, conn->id, itt, datalen);
1164
1165         if (itt == ~0U) {
1166                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1167
1168                 switch(opcode) {
1169                 case ISCSI_OP_NOOP_IN:
1170                         if (datalen) {
1171                                 rc = ISCSI_ERR_PROTO;
1172                                 break;
1173                         }
1174
1175                         if (hdr->ttt == cpu_to_be32(ISCSI_RESERVED_TAG))
1176                                 break;
1177
1178                         /* In RX path we are under back lock */
1179                         spin_unlock(&session->back_lock);
1180                         spin_lock(&session->frwd_lock);
1181                         iscsi_send_nopout(conn, (struct iscsi_nopin*)hdr);
1182                         spin_unlock(&session->frwd_lock);
1183                         spin_lock(&session->back_lock);
1184                         break;
1185                 case ISCSI_OP_REJECT:
1186                         rc = iscsi_handle_reject(conn, hdr, data, datalen);
1187                         break;
1188                 case ISCSI_OP_ASYNC_EVENT:
1189                         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1190                         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
1191                                 rc = ISCSI_ERR_CONN_FAILED;
1192                         break;
1193                 default:
1194                         rc = ISCSI_ERR_BAD_OPCODE;
1195                         break;
1196                 }
1197                 goto out;
1198         }
1199
1200         switch(opcode) {
1201         case ISCSI_OP_SCSI_CMD_RSP:
1202         case ISCSI_OP_SCSI_DATA_IN:
1203                 task = iscsi_itt_to_ctask(conn, hdr->itt);
1204                 if (!task)
1205                         return ISCSI_ERR_BAD_ITT;
1206                 task->last_xfer = jiffies;
1207                 break;
1208         case ISCSI_OP_R2T:
1209                 /*
1210                  * LLD handles R2Ts if they need to.
1211                  */
1212                 return 0;
1213         case ISCSI_OP_LOGOUT_RSP:
1214         case ISCSI_OP_LOGIN_RSP:
1215         case ISCSI_OP_TEXT_RSP:
1216         case ISCSI_OP_SCSI_TMFUNC_RSP:
1217         case ISCSI_OP_NOOP_IN:
1218                 task = iscsi_itt_to_task(conn, hdr->itt);
1219                 if (!task)
1220                         return ISCSI_ERR_BAD_ITT;
1221                 break;
1222         default:
1223                 return ISCSI_ERR_BAD_OPCODE;
1224         }
1225
1226         switch(opcode) {
1227         case ISCSI_OP_SCSI_CMD_RSP:
1228                 iscsi_scsi_cmd_rsp(conn, hdr, task, data, datalen);
1229                 break;
1230         case ISCSI_OP_SCSI_DATA_IN:
1231                 iscsi_data_in_rsp(conn, hdr, task);
1232                 break;
1233         case ISCSI_OP_LOGOUT_RSP:
1234                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1235                 if (datalen) {
1236                         rc = ISCSI_ERR_PROTO;
1237                         break;
1238                 }
1239                 conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1240                 goto recv_pdu;
1241         case ISCSI_OP_LOGIN_RSP:
1242         case ISCSI_OP_TEXT_RSP:
1243                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1244                 /*
1245                  * login related PDU's exp_statsn is handled in
1246                  * userspace
1247                  */
1248                 goto recv_pdu;
1249         case ISCSI_OP_SCSI_TMFUNC_RSP:
1250                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1251                 if (datalen) {
1252                         rc = ISCSI_ERR_PROTO;
1253                         break;
1254                 }
1255
1256                 iscsi_tmf_rsp(conn, hdr);
1257                 iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1258                 break;
1259         case ISCSI_OP_NOOP_IN:
1260                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1261                 if (hdr->ttt != cpu_to_be32(ISCSI_RESERVED_TAG) || datalen) {
1262                         rc = ISCSI_ERR_PROTO;
1263                         break;
1264                 }
1265                 conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1266
1267                 rc = iscsi_nop_out_rsp(task, (struct iscsi_nopin*)hdr,
1268                                        data, datalen);
1269                 break;
1270         default:
1271                 rc = ISCSI_ERR_BAD_OPCODE;
1272                 break;
1273         }
1274
1275 out:
1276         return rc;
1277 recv_pdu:
1278         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
1279                 rc = ISCSI_ERR_CONN_FAILED;
1280         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1281         return rc;
1282 }
1283 EXPORT_SYMBOL_GPL(__iscsi_complete_pdu);
1284
1285 int iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1286                        char *data, int datalen)
1287 {
1288         int rc;
1289
1290         spin_lock(&conn->session->back_lock);
1291         rc = __iscsi_complete_pdu(conn, hdr, data, datalen);
1292         spin_unlock(&conn->session->back_lock);
1293         return rc;
1294 }
1295 EXPORT_SYMBOL_GPL(iscsi_complete_pdu);
1296
1297 int iscsi_verify_itt(struct iscsi_conn *conn, itt_t itt)
1298 {
1299         struct iscsi_session *session = conn->session;
1300         int age = 0, i = 0;
1301
1302         if (itt == RESERVED_ITT)
1303                 return 0;
1304
1305         if (session->tt->parse_pdu_itt)
1306                 session->tt->parse_pdu_itt(conn, itt, &i, &age);
1307         else {
1308                 i = get_itt(itt);
1309                 age = ((__force u32)itt >> ISCSI_AGE_SHIFT) & ISCSI_AGE_MASK;
1310         }
1311
1312         if (age != session->age) {
1313                 iscsi_conn_printk(KERN_ERR, conn,
1314                                   "received itt %x expected session age (%x)\n",
1315                                   (__force u32)itt, session->age);
1316                 return ISCSI_ERR_BAD_ITT;
1317         }
1318
1319         if (i >= session->cmds_max) {
1320                 iscsi_conn_printk(KERN_ERR, conn,
1321                                   "received invalid itt index %u (max cmds "
1322                                    "%u.\n", i, session->cmds_max);
1323                 return ISCSI_ERR_BAD_ITT;
1324         }
1325         return 0;
1326 }
1327 EXPORT_SYMBOL_GPL(iscsi_verify_itt);
1328
1329 /**
1330  * iscsi_itt_to_ctask - look up ctask by itt
1331  * @conn: iscsi connection
1332  * @itt: itt
1333  *
1334  * This should be used for cmd tasks.
1335  *
1336  * The session back_lock must be held.
1337  */
1338 struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *conn, itt_t itt)
1339 {
1340         struct iscsi_task *task;
1341
1342         if (iscsi_verify_itt(conn, itt))
1343                 return NULL;
1344
1345         task = iscsi_itt_to_task(conn, itt);
1346         if (!task || !task->sc)
1347                 return NULL;
1348
1349         if (task->sc->SCp.phase != conn->session->age) {
1350                 iscsi_session_printk(KERN_ERR, conn->session,
1351                                   "task's session age %d, expected %d\n",
1352                                   task->sc->SCp.phase, conn->session->age);
1353                 return NULL;
1354         }
1355
1356         return task;
1357 }
1358 EXPORT_SYMBOL_GPL(iscsi_itt_to_ctask);
1359
1360 void iscsi_session_failure(struct iscsi_session *session,
1361                            enum iscsi_err err)
1362 {
1363         struct iscsi_conn *conn;
1364         struct device *dev;
1365
1366         spin_lock_bh(&session->frwd_lock);
1367         conn = session->leadconn;
1368         if (session->state == ISCSI_STATE_TERMINATE || !conn) {
1369                 spin_unlock_bh(&session->frwd_lock);
1370                 return;
1371         }
1372
1373         dev = get_device(&conn->cls_conn->dev);
1374         spin_unlock_bh(&session->frwd_lock);
1375         if (!dev)
1376                 return;
1377         /*
1378          * if the host is being removed bypass the connection
1379          * recovery initialization because we are going to kill
1380          * the session.
1381          */
1382         if (err == ISCSI_ERR_INVALID_HOST)
1383                 iscsi_conn_error_event(conn->cls_conn, err);
1384         else
1385                 iscsi_conn_failure(conn, err);
1386         put_device(dev);
1387 }
1388 EXPORT_SYMBOL_GPL(iscsi_session_failure);
1389
1390 void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err)
1391 {
1392         struct iscsi_session *session = conn->session;
1393
1394         spin_lock_bh(&session->frwd_lock);
1395         if (session->state == ISCSI_STATE_FAILED) {
1396                 spin_unlock_bh(&session->frwd_lock);
1397                 return;
1398         }
1399
1400         if (conn->stop_stage == 0)
1401                 session->state = ISCSI_STATE_FAILED;
1402         spin_unlock_bh(&session->frwd_lock);
1403
1404         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1405         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
1406         iscsi_conn_error_event(conn->cls_conn, err);
1407 }
1408 EXPORT_SYMBOL_GPL(iscsi_conn_failure);
1409
1410 static int iscsi_check_cmdsn_window_closed(struct iscsi_conn *conn)
1411 {
1412         struct iscsi_session *session = conn->session;
1413
1414         /*
1415          * Check for iSCSI window and take care of CmdSN wrap-around
1416          */
1417         if (!iscsi_sna_lte(session->queued_cmdsn, session->max_cmdsn)) {
1418                 ISCSI_DBG_SESSION(session, "iSCSI CmdSN closed. ExpCmdSn "
1419                                   "%u MaxCmdSN %u CmdSN %u/%u\n",
1420                                   session->exp_cmdsn, session->max_cmdsn,
1421                                   session->cmdsn, session->queued_cmdsn);
1422                 return -ENOSPC;
1423         }
1424         return 0;
1425 }
1426
1427 static int iscsi_xmit_task(struct iscsi_conn *conn, struct iscsi_task *task,
1428                            bool was_requeue)
1429 {
1430         int rc;
1431
1432         spin_lock_bh(&conn->session->back_lock);
1433
1434         if (!conn->task) {
1435                 /* Take a ref so we can access it after xmit_task() */
1436                 __iscsi_get_task(task);
1437         } else {
1438                 /* Already have a ref from when we failed to send it last call */
1439                 conn->task = NULL;
1440         }
1441
1442         /*
1443          * If this was a requeue for a R2T we have an extra ref on the task in
1444          * case a bad target sends a cmd rsp before we have handled the task.
1445          */
1446         if (was_requeue)
1447                 __iscsi_put_task(task);
1448
1449         /*
1450          * Do this after dropping the extra ref because if this was a requeue
1451          * it's removed from that list and cleanup_queued_task would miss it.
1452          */
1453         if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx)) {
1454                 /*
1455                  * Save the task and ref in case we weren't cleaning up this
1456                  * task and get woken up again.
1457                  */
1458                 conn->task = task;
1459                 spin_unlock_bh(&conn->session->back_lock);
1460                 return -ENODATA;
1461         }
1462         spin_unlock_bh(&conn->session->back_lock);
1463
1464         spin_unlock_bh(&conn->session->frwd_lock);
1465         rc = conn->session->tt->xmit_task(task);
1466         spin_lock_bh(&conn->session->frwd_lock);
1467         if (!rc) {
1468                 /* done with this task */
1469                 task->last_xfer = jiffies;
1470         }
1471         /* regular RX path uses back_lock */
1472         spin_lock(&conn->session->back_lock);
1473         if (rc && task->state == ISCSI_TASK_RUNNING) {
1474                 /*
1475                  * get an extra ref that is released next time we access it
1476                  * as conn->task above.
1477                  */
1478                 __iscsi_get_task(task);
1479                 conn->task = task;
1480         }
1481
1482         __iscsi_put_task(task);
1483         spin_unlock(&conn->session->back_lock);
1484         return rc;
1485 }
1486
1487 /**
1488  * iscsi_requeue_task - requeue task to run from session workqueue
1489  * @task: task to requeue
1490  *
1491  * Callers must have taken a ref to the task that is going to be requeued.
1492  */
1493 void iscsi_requeue_task(struct iscsi_task *task)
1494 {
1495         struct iscsi_conn *conn = task->conn;
1496
1497         /*
1498          * this may be on the requeue list already if the xmit_task callout
1499          * is handling the r2ts while we are adding new ones
1500          */
1501         spin_lock_bh(&conn->session->frwd_lock);
1502         if (list_empty(&task->running)) {
1503                 list_add_tail(&task->running, &conn->requeue);
1504         } else {
1505                 /*
1506                  * Don't need the extra ref since it's already requeued and
1507                  * has a ref.
1508                  */
1509                 iscsi_put_task(task);
1510         }
1511         iscsi_conn_queue_work(conn);
1512         spin_unlock_bh(&conn->session->frwd_lock);
1513 }
1514 EXPORT_SYMBOL_GPL(iscsi_requeue_task);
1515
1516 /**
1517  * iscsi_data_xmit - xmit any command into the scheduled connection
1518  * @conn: iscsi connection
1519  *
1520  * Notes:
1521  *      The function can return -EAGAIN in which case the caller must
1522  *      re-schedule it again later or recover. '0' return code means
1523  *      successful xmit.
1524  **/
1525 static int iscsi_data_xmit(struct iscsi_conn *conn)
1526 {
1527         struct iscsi_task *task;
1528         int rc = 0;
1529
1530         spin_lock_bh(&conn->session->frwd_lock);
1531         if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx)) {
1532                 ISCSI_DBG_SESSION(conn->session, "Tx suspended!\n");
1533                 spin_unlock_bh(&conn->session->frwd_lock);
1534                 return -ENODATA;
1535         }
1536
1537         if (conn->task) {
1538                 rc = iscsi_xmit_task(conn, conn->task, false);
1539                 if (rc)
1540                         goto done;
1541         }
1542
1543         /*
1544          * process mgmt pdus like nops before commands since we should
1545          * only have one nop-out as a ping from us and targets should not
1546          * overflow us with nop-ins
1547          */
1548 check_mgmt:
1549         while (!list_empty(&conn->mgmtqueue)) {
1550                 task = list_entry(conn->mgmtqueue.next, struct iscsi_task,
1551                                   running);
1552                 list_del_init(&task->running);
1553                 if (iscsi_prep_mgmt_task(conn, task)) {
1554                         /* regular RX path uses back_lock */
1555                         spin_lock_bh(&conn->session->back_lock);
1556                         __iscsi_put_task(task);
1557                         spin_unlock_bh(&conn->session->back_lock);
1558                         continue;
1559                 }
1560                 rc = iscsi_xmit_task(conn, task, false);
1561                 if (rc)
1562                         goto done;
1563         }
1564
1565         /* process pending command queue */
1566         while (!list_empty(&conn->cmdqueue)) {
1567                 task = list_entry(conn->cmdqueue.next, struct iscsi_task,
1568                                   running);
1569                 list_del_init(&task->running);
1570                 if (conn->session->state == ISCSI_STATE_LOGGING_OUT) {
1571                         fail_scsi_task(task, DID_IMM_RETRY);
1572                         continue;
1573                 }
1574                 rc = iscsi_prep_scsi_cmd_pdu(task);
1575                 if (rc) {
1576                         if (rc == -ENOMEM || rc == -EACCES)
1577                                 fail_scsi_task(task, DID_IMM_RETRY);
1578                         else
1579                                 fail_scsi_task(task, DID_ABORT);
1580                         continue;
1581                 }
1582                 rc = iscsi_xmit_task(conn, task, false);
1583                 if (rc)
1584                         goto done;
1585                 /*
1586                  * we could continuously get new task requests so
1587                  * we need to check the mgmt queue for nops that need to
1588                  * be sent to aviod starvation
1589                  */
1590                 if (!list_empty(&conn->mgmtqueue))
1591                         goto check_mgmt;
1592         }
1593
1594         while (!list_empty(&conn->requeue)) {
1595                 /*
1596                  * we always do fastlogout - conn stop code will clean up.
1597                  */
1598                 if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
1599                         break;
1600
1601                 task = list_entry(conn->requeue.next, struct iscsi_task,
1602                                   running);
1603
1604                 if (iscsi_check_tmf_restrictions(task, ISCSI_OP_SCSI_DATA_OUT))
1605                         break;
1606
1607                 list_del_init(&task->running);
1608                 rc = iscsi_xmit_task(conn, task, true);
1609                 if (rc)
1610                         goto done;
1611                 if (!list_empty(&conn->mgmtqueue))
1612                         goto check_mgmt;
1613         }
1614         spin_unlock_bh(&conn->session->frwd_lock);
1615         return -ENODATA;
1616
1617 done:
1618         spin_unlock_bh(&conn->session->frwd_lock);
1619         return rc;
1620 }
1621
1622 static void iscsi_xmitworker(struct work_struct *work)
1623 {
1624         struct iscsi_conn *conn =
1625                 container_of(work, struct iscsi_conn, xmitwork);
1626         int rc;
1627         /*
1628          * serialize Xmit worker on a per-connection basis.
1629          */
1630         do {
1631                 rc = iscsi_data_xmit(conn);
1632         } while (rc >= 0 || rc == -EAGAIN);
1633 }
1634
1635 static inline struct iscsi_task *iscsi_alloc_task(struct iscsi_conn *conn,
1636                                                   struct scsi_cmnd *sc)
1637 {
1638         struct iscsi_task *task;
1639
1640         if (!kfifo_out(&conn->session->cmdpool.queue,
1641                          (void *) &task, sizeof(void *)))
1642                 return NULL;
1643
1644         sc->SCp.phase = conn->session->age;
1645         sc->SCp.ptr = (char *) task;
1646
1647         refcount_set(&task->refcount, 1);
1648         task->state = ISCSI_TASK_PENDING;
1649         task->conn = conn;
1650         task->sc = sc;
1651         task->have_checked_conn = false;
1652         task->last_timeout = jiffies;
1653         task->last_xfer = jiffies;
1654         task->protected = false;
1655         INIT_LIST_HEAD(&task->running);
1656         return task;
1657 }
1658
1659 enum {
1660         FAILURE_BAD_HOST = 1,
1661         FAILURE_SESSION_FAILED,
1662         FAILURE_SESSION_FREED,
1663         FAILURE_WINDOW_CLOSED,
1664         FAILURE_OOM,
1665         FAILURE_SESSION_TERMINATE,
1666         FAILURE_SESSION_IN_RECOVERY,
1667         FAILURE_SESSION_RECOVERY_TIMEOUT,
1668         FAILURE_SESSION_LOGGING_OUT,
1669         FAILURE_SESSION_NOT_READY,
1670 };
1671
1672 int iscsi_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *sc)
1673 {
1674         struct iscsi_cls_session *cls_session;
1675         struct iscsi_host *ihost;
1676         int reason = 0;
1677         struct iscsi_session *session;
1678         struct iscsi_conn *conn;
1679         struct iscsi_task *task = NULL;
1680
1681         sc->result = 0;
1682         sc->SCp.ptr = NULL;
1683
1684         ihost = shost_priv(host);
1685
1686         cls_session = starget_to_session(scsi_target(sc->device));
1687         session = cls_session->dd_data;
1688         spin_lock_bh(&session->frwd_lock);
1689
1690         reason = iscsi_session_chkready(cls_session);
1691         if (reason) {
1692                 sc->result = reason;
1693                 goto fault;
1694         }
1695
1696         if (session->state != ISCSI_STATE_LOGGED_IN) {
1697                 /*
1698                  * to handle the race between when we set the recovery state
1699                  * and block the session we requeue here (commands could
1700                  * be entering our queuecommand while a block is starting
1701                  * up because the block code is not locked)
1702                  */
1703                 switch (session->state) {
1704                 case ISCSI_STATE_FAILED:
1705                         /*
1706                          * cmds should fail during shutdown, if the session
1707                          * state is bad, allowing completion to happen
1708                          */
1709                         if (unlikely(system_state != SYSTEM_RUNNING)) {
1710                                 reason = FAILURE_SESSION_FAILED;
1711                                 sc->result = DID_NO_CONNECT << 16;
1712                                 break;
1713                         }
1714                         fallthrough;
1715                 case ISCSI_STATE_IN_RECOVERY:
1716                         reason = FAILURE_SESSION_IN_RECOVERY;
1717                         sc->result = DID_IMM_RETRY << 16;
1718                         break;
1719                 case ISCSI_STATE_LOGGING_OUT:
1720                         reason = FAILURE_SESSION_LOGGING_OUT;
1721                         sc->result = DID_IMM_RETRY << 16;
1722                         break;
1723                 case ISCSI_STATE_RECOVERY_FAILED:
1724                         reason = FAILURE_SESSION_RECOVERY_TIMEOUT;
1725                         sc->result = DID_TRANSPORT_FAILFAST << 16;
1726                         break;
1727                 case ISCSI_STATE_TERMINATE:
1728                         reason = FAILURE_SESSION_TERMINATE;
1729                         sc->result = DID_NO_CONNECT << 16;
1730                         break;
1731                 default:
1732                         reason = FAILURE_SESSION_FREED;
1733                         sc->result = DID_NO_CONNECT << 16;
1734                 }
1735                 goto fault;
1736         }
1737
1738         conn = session->leadconn;
1739         if (!conn) {
1740                 reason = FAILURE_SESSION_FREED;
1741                 sc->result = DID_NO_CONNECT << 16;
1742                 goto fault;
1743         }
1744
1745         if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx)) {
1746                 reason = FAILURE_SESSION_IN_RECOVERY;
1747                 sc->result = DID_REQUEUE << 16;
1748                 goto fault;
1749         }
1750
1751         if (iscsi_check_cmdsn_window_closed(conn)) {
1752                 reason = FAILURE_WINDOW_CLOSED;
1753                 goto reject;
1754         }
1755
1756         task = iscsi_alloc_task(conn, sc);
1757         if (!task) {
1758                 reason = FAILURE_OOM;
1759                 goto reject;
1760         }
1761
1762         if (!ihost->workq) {
1763                 reason = iscsi_prep_scsi_cmd_pdu(task);
1764                 if (reason) {
1765                         if (reason == -ENOMEM ||  reason == -EACCES) {
1766                                 reason = FAILURE_OOM;
1767                                 goto prepd_reject;
1768                         } else {
1769                                 sc->result = DID_ABORT << 16;
1770                                 goto prepd_fault;
1771                         }
1772                 }
1773                 if (session->tt->xmit_task(task)) {
1774                         session->cmdsn--;
1775                         reason = FAILURE_SESSION_NOT_READY;
1776                         goto prepd_reject;
1777                 }
1778         } else {
1779                 list_add_tail(&task->running, &conn->cmdqueue);
1780                 iscsi_conn_queue_work(conn);
1781         }
1782
1783         session->queued_cmdsn++;
1784         spin_unlock_bh(&session->frwd_lock);
1785         return 0;
1786
1787 prepd_reject:
1788         spin_lock_bh(&session->back_lock);
1789         iscsi_complete_task(task, ISCSI_TASK_REQUEUE_SCSIQ);
1790         spin_unlock_bh(&session->back_lock);
1791 reject:
1792         spin_unlock_bh(&session->frwd_lock);
1793         ISCSI_DBG_SESSION(session, "cmd 0x%x rejected (%d)\n",
1794                           sc->cmnd[0], reason);
1795         return SCSI_MLQUEUE_TARGET_BUSY;
1796
1797 prepd_fault:
1798         spin_lock_bh(&session->back_lock);
1799         iscsi_complete_task(task, ISCSI_TASK_REQUEUE_SCSIQ);
1800         spin_unlock_bh(&session->back_lock);
1801 fault:
1802         spin_unlock_bh(&session->frwd_lock);
1803         ISCSI_DBG_SESSION(session, "iscsi: cmd 0x%x is not queued (%d)\n",
1804                           sc->cmnd[0], reason);
1805         scsi_set_resid(sc, scsi_bufflen(sc));
1806         sc->scsi_done(sc);
1807         return 0;
1808 }
1809 EXPORT_SYMBOL_GPL(iscsi_queuecommand);
1810
1811 int iscsi_target_alloc(struct scsi_target *starget)
1812 {
1813         struct iscsi_cls_session *cls_session = starget_to_session(starget);
1814         struct iscsi_session *session = cls_session->dd_data;
1815
1816         starget->can_queue = session->scsi_cmds_max;
1817         return 0;
1818 }
1819 EXPORT_SYMBOL_GPL(iscsi_target_alloc);
1820
1821 static void iscsi_tmf_timedout(struct timer_list *t)
1822 {
1823         struct iscsi_conn *conn = from_timer(conn, t, tmf_timer);
1824         struct iscsi_session *session = conn->session;
1825
1826         spin_lock(&session->frwd_lock);
1827         if (conn->tmf_state == TMF_QUEUED) {
1828                 conn->tmf_state = TMF_TIMEDOUT;
1829                 ISCSI_DBG_EH(session, "tmf timedout\n");
1830                 /* unblock eh_abort() */
1831                 wake_up(&conn->ehwait);
1832         }
1833         spin_unlock(&session->frwd_lock);
1834 }
1835
1836 static int iscsi_exec_task_mgmt_fn(struct iscsi_conn *conn,
1837                                    struct iscsi_tm *hdr, int age,
1838                                    int timeout)
1839         __must_hold(&session->frwd_lock)
1840 {
1841         struct iscsi_session *session = conn->session;
1842         struct iscsi_task *task;
1843
1844         task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)hdr,
1845                                       NULL, 0);
1846         if (!task) {
1847                 spin_unlock_bh(&session->frwd_lock);
1848                 iscsi_conn_printk(KERN_ERR, conn, "Could not send TMF.\n");
1849                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1850                 spin_lock_bh(&session->frwd_lock);
1851                 return -EPERM;
1852         }
1853         conn->tmfcmd_pdus_cnt++;
1854         conn->tmf_timer.expires = timeout * HZ + jiffies;
1855         add_timer(&conn->tmf_timer);
1856         ISCSI_DBG_EH(session, "tmf set timeout\n");
1857
1858         spin_unlock_bh(&session->frwd_lock);
1859         mutex_unlock(&session->eh_mutex);
1860
1861         /*
1862          * block eh thread until:
1863          *
1864          * 1) tmf response
1865          * 2) tmf timeout
1866          * 3) session is terminated or restarted or userspace has
1867          * given up on recovery
1868          */
1869         wait_event_interruptible(conn->ehwait, age != session->age ||
1870                                  session->state != ISCSI_STATE_LOGGED_IN ||
1871                                  conn->tmf_state != TMF_QUEUED);
1872         if (signal_pending(current))
1873                 flush_signals(current);
1874         del_timer_sync(&conn->tmf_timer);
1875
1876         mutex_lock(&session->eh_mutex);
1877         spin_lock_bh(&session->frwd_lock);
1878         /* if the session drops it will clean up the task */
1879         if (age != session->age ||
1880             session->state != ISCSI_STATE_LOGGED_IN)
1881                 return -ENOTCONN;
1882         return 0;
1883 }
1884
1885 /*
1886  * Fail commands. session frwd lock held and xmit thread flushed.
1887  */
1888 static void fail_scsi_tasks(struct iscsi_conn *conn, u64 lun, int error)
1889 {
1890         struct iscsi_session *session = conn->session;
1891         struct iscsi_task *task;
1892         int i;
1893
1894         spin_lock_bh(&session->back_lock);
1895         for (i = 0; i < session->cmds_max; i++) {
1896                 task = session->cmds[i];
1897                 if (!task->sc || task->state == ISCSI_TASK_FREE)
1898                         continue;
1899
1900                 if (lun != -1 && lun != task->sc->device->lun)
1901                         continue;
1902
1903                 __iscsi_get_task(task);
1904                 spin_unlock_bh(&session->back_lock);
1905
1906                 ISCSI_DBG_SESSION(session,
1907                                   "failing sc %p itt 0x%x state %d\n",
1908                                   task->sc, task->itt, task->state);
1909                 fail_scsi_task(task, error);
1910
1911                 spin_unlock_bh(&session->frwd_lock);
1912                 iscsi_put_task(task);
1913                 spin_lock_bh(&session->frwd_lock);
1914
1915                 spin_lock_bh(&session->back_lock);
1916         }
1917
1918         spin_unlock_bh(&session->back_lock);
1919 }
1920
1921 /**
1922  * iscsi_suspend_queue - suspend iscsi_queuecommand
1923  * @conn: iscsi conn to stop queueing IO on
1924  *
1925  * This grabs the session frwd_lock to make sure no one is in
1926  * xmit_task/queuecommand, and then sets suspend to prevent
1927  * new commands from being queued. This only needs to be called
1928  * by offload drivers that need to sync a path like ep disconnect
1929  * with the iscsi_queuecommand/xmit_task. To start IO again libiscsi
1930  * will call iscsi_start_tx and iscsi_unblock_session when in FFP.
1931  */
1932 void iscsi_suspend_queue(struct iscsi_conn *conn)
1933 {
1934         spin_lock_bh(&conn->session->frwd_lock);
1935         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1936         spin_unlock_bh(&conn->session->frwd_lock);
1937 }
1938 EXPORT_SYMBOL_GPL(iscsi_suspend_queue);
1939
1940 /**
1941  * iscsi_suspend_tx - suspend iscsi_data_xmit
1942  * @conn: iscsi conn tp stop processing IO on.
1943  *
1944  * This function sets the suspend bit to prevent iscsi_data_xmit
1945  * from sending new IO, and if work is queued on the xmit thread
1946  * it will wait for it to be completed.
1947  */
1948 void iscsi_suspend_tx(struct iscsi_conn *conn)
1949 {
1950         struct Scsi_Host *shost = conn->session->host;
1951         struct iscsi_host *ihost = shost_priv(shost);
1952
1953         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1954         if (ihost->workq)
1955                 flush_workqueue(ihost->workq);
1956 }
1957 EXPORT_SYMBOL_GPL(iscsi_suspend_tx);
1958
1959 static void iscsi_start_tx(struct iscsi_conn *conn)
1960 {
1961         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1962         iscsi_conn_queue_work(conn);
1963 }
1964
1965 /*
1966  * We want to make sure a ping is in flight. It has timed out.
1967  * And we are not busy processing a pdu that is making
1968  * progress but got started before the ping and is taking a while
1969  * to complete so the ping is just stuck behind it in a queue.
1970  */
1971 static int iscsi_has_ping_timed_out(struct iscsi_conn *conn)
1972 {
1973         if (READ_ONCE(conn->ping_task) &&
1974             time_before_eq(conn->last_recv + (conn->recv_timeout * HZ) +
1975                            (conn->ping_timeout * HZ), jiffies))
1976                 return 1;
1977         else
1978                 return 0;
1979 }
1980
1981 enum blk_eh_timer_return iscsi_eh_cmd_timed_out(struct scsi_cmnd *sc)
1982 {
1983         enum blk_eh_timer_return rc = BLK_EH_DONE;
1984         struct iscsi_task *task = NULL, *running_task;
1985         struct iscsi_cls_session *cls_session;
1986         struct iscsi_session *session;
1987         struct iscsi_conn *conn;
1988         int i;
1989
1990         cls_session = starget_to_session(scsi_target(sc->device));
1991         session = cls_session->dd_data;
1992
1993         ISCSI_DBG_EH(session, "scsi cmd %p timedout\n", sc);
1994
1995         spin_lock_bh(&session->frwd_lock);
1996         spin_lock(&session->back_lock);
1997         task = (struct iscsi_task *)sc->SCp.ptr;
1998         if (!task) {
1999                 /*
2000                  * Raced with completion. Blk layer has taken ownership
2001                  * so let timeout code complete it now.
2002                  */
2003                 rc = BLK_EH_DONE;
2004                 spin_unlock(&session->back_lock);
2005                 goto done;
2006         }
2007         __iscsi_get_task(task);
2008         spin_unlock(&session->back_lock);
2009
2010         if (session->state != ISCSI_STATE_LOGGED_IN) {
2011                 /*
2012                  * During shutdown, if session is prematurely disconnected,
2013                  * recovery won't happen and there will be hung cmds. Not
2014                  * handling cmds would trigger EH, also bad in this case.
2015                  * Instead, handle cmd, allow completion to happen and let
2016                  * upper layer to deal with the result.
2017                  */
2018                 if (unlikely(system_state != SYSTEM_RUNNING)) {
2019                         sc->result = DID_NO_CONNECT << 16;
2020                         ISCSI_DBG_EH(session, "sc on shutdown, handled\n");
2021                         rc = BLK_EH_DONE;
2022                         goto done;
2023                 }
2024                 /*
2025                  * We are probably in the middle of iscsi recovery so let
2026                  * that complete and handle the error.
2027                  */
2028                 rc = BLK_EH_RESET_TIMER;
2029                 goto done;
2030         }
2031
2032         conn = session->leadconn;
2033         if (!conn) {
2034                 /* In the middle of shuting down */
2035                 rc = BLK_EH_RESET_TIMER;
2036                 goto done;
2037         }
2038
2039         /*
2040          * If we have sent (at least queued to the network layer) a pdu or
2041          * recvd one for the task since the last timeout ask for
2042          * more time. If on the next timeout we have not made progress
2043          * we can check if it is the task or connection when we send the
2044          * nop as a ping.
2045          */
2046         if (time_after(task->last_xfer, task->last_timeout)) {
2047                 ISCSI_DBG_EH(session, "Command making progress. Asking "
2048                              "scsi-ml for more time to complete. "
2049                              "Last data xfer at %lu. Last timeout was at "
2050                              "%lu\n.", task->last_xfer, task->last_timeout);
2051                 task->have_checked_conn = false;
2052                 rc = BLK_EH_RESET_TIMER;
2053                 goto done;
2054         }
2055
2056         if (!conn->recv_timeout && !conn->ping_timeout)
2057                 goto done;
2058         /*
2059          * if the ping timedout then we are in the middle of cleaning up
2060          * and can let the iscsi eh handle it
2061          */
2062         if (iscsi_has_ping_timed_out(conn)) {
2063                 rc = BLK_EH_RESET_TIMER;
2064                 goto done;
2065         }
2066
2067         spin_lock(&session->back_lock);
2068         for (i = 0; i < conn->session->cmds_max; i++) {
2069                 running_task = conn->session->cmds[i];
2070                 if (!running_task->sc || running_task == task ||
2071                      running_task->state != ISCSI_TASK_RUNNING)
2072                         continue;
2073
2074                 /*
2075                  * Only check if cmds started before this one have made
2076                  * progress, or this could never fail
2077                  */
2078                 if (time_after(running_task->sc->jiffies_at_alloc,
2079                                task->sc->jiffies_at_alloc))
2080                         continue;
2081
2082                 if (time_after(running_task->last_xfer, task->last_timeout)) {
2083                         /*
2084                          * This task has not made progress, but a task
2085                          * started before us has transferred data since
2086                          * we started/last-checked. We could be queueing
2087                          * too many tasks or the LU is bad.
2088                          *
2089                          * If the device is bad the cmds ahead of us on
2090                          * other devs will complete, and this loop will
2091                          * eventually fail starting the scsi eh.
2092                          */
2093                         ISCSI_DBG_EH(session, "Command has not made progress "
2094                                      "but commands ahead of it have. "
2095                                      "Asking scsi-ml for more time to "
2096                                      "complete. Our last xfer vs running task "
2097                                      "last xfer %lu/%lu. Last check %lu.\n",
2098                                      task->last_xfer, running_task->last_xfer,
2099                                      task->last_timeout);
2100                         spin_unlock(&session->back_lock);
2101                         rc = BLK_EH_RESET_TIMER;
2102                         goto done;
2103                 }
2104         }
2105         spin_unlock(&session->back_lock);
2106
2107         /* Assumes nop timeout is shorter than scsi cmd timeout */
2108         if (task->have_checked_conn)
2109                 goto done;
2110
2111         /*
2112          * Checking the transport already or nop from a cmd timeout still
2113          * running
2114          */
2115         if (READ_ONCE(conn->ping_task)) {
2116                 task->have_checked_conn = true;
2117                 rc = BLK_EH_RESET_TIMER;
2118                 goto done;
2119         }
2120
2121         /* Make sure there is a transport check done */
2122         iscsi_send_nopout(conn, NULL);
2123         task->have_checked_conn = true;
2124         rc = BLK_EH_RESET_TIMER;
2125
2126 done:
2127         spin_unlock_bh(&session->frwd_lock);
2128
2129         if (task) {
2130                 task->last_timeout = jiffies;
2131                 iscsi_put_task(task);
2132         }
2133         ISCSI_DBG_EH(session, "return %s\n", rc == BLK_EH_RESET_TIMER ?
2134                      "timer reset" : "shutdown or nh");
2135         return rc;
2136 }
2137 EXPORT_SYMBOL_GPL(iscsi_eh_cmd_timed_out);
2138
2139 static void iscsi_check_transport_timeouts(struct timer_list *t)
2140 {
2141         struct iscsi_conn *conn = from_timer(conn, t, transport_timer);
2142         struct iscsi_session *session = conn->session;
2143         unsigned long recv_timeout, next_timeout = 0, last_recv;
2144
2145         spin_lock(&session->frwd_lock);
2146         if (session->state != ISCSI_STATE_LOGGED_IN)
2147                 goto done;
2148
2149         recv_timeout = conn->recv_timeout;
2150         if (!recv_timeout)
2151                 goto done;
2152
2153         recv_timeout *= HZ;
2154         last_recv = conn->last_recv;
2155
2156         if (iscsi_has_ping_timed_out(conn)) {
2157                 iscsi_conn_printk(KERN_ERR, conn, "ping timeout of %d secs "
2158                                   "expired, recv timeout %d, last rx %lu, "
2159                                   "last ping %lu, now %lu\n",
2160                                   conn->ping_timeout, conn->recv_timeout,
2161                                   last_recv, conn->last_ping, jiffies);
2162                 spin_unlock(&session->frwd_lock);
2163                 iscsi_conn_failure(conn, ISCSI_ERR_NOP_TIMEDOUT);
2164                 return;
2165         }
2166
2167         if (time_before_eq(last_recv + recv_timeout, jiffies)) {
2168                 /* send a ping to try to provoke some traffic */
2169                 ISCSI_DBG_CONN(conn, "Sending nopout as ping\n");
2170                 if (iscsi_send_nopout(conn, NULL))
2171                         next_timeout = jiffies + (1 * HZ);
2172                 else
2173                         next_timeout = conn->last_ping + (conn->ping_timeout * HZ);
2174         } else
2175                 next_timeout = last_recv + recv_timeout;
2176
2177         ISCSI_DBG_CONN(conn, "Setting next tmo %lu\n", next_timeout);
2178         mod_timer(&conn->transport_timer, next_timeout);
2179 done:
2180         spin_unlock(&session->frwd_lock);
2181 }
2182
2183 static void iscsi_prep_abort_task_pdu(struct iscsi_task *task,
2184                                       struct iscsi_tm *hdr)
2185 {
2186         memset(hdr, 0, sizeof(*hdr));
2187         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2188         hdr->flags = ISCSI_TM_FUNC_ABORT_TASK & ISCSI_FLAG_TM_FUNC_MASK;
2189         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2190         hdr->lun = task->lun;
2191         hdr->rtt = task->hdr_itt;
2192         hdr->refcmdsn = task->cmdsn;
2193 }
2194
2195 int iscsi_eh_abort(struct scsi_cmnd *sc)
2196 {
2197         struct iscsi_cls_session *cls_session;
2198         struct iscsi_session *session;
2199         struct iscsi_conn *conn;
2200         struct iscsi_task *task;
2201         struct iscsi_tm *hdr;
2202         int age;
2203
2204         cls_session = starget_to_session(scsi_target(sc->device));
2205         session = cls_session->dd_data;
2206
2207         ISCSI_DBG_EH(session, "aborting sc %p\n", sc);
2208
2209         mutex_lock(&session->eh_mutex);
2210         spin_lock_bh(&session->frwd_lock);
2211         /*
2212          * if session was ISCSI_STATE_IN_RECOVERY then we may not have
2213          * got the command.
2214          */
2215         if (!sc->SCp.ptr) {
2216                 ISCSI_DBG_EH(session, "sc never reached iscsi layer or "
2217                                       "it completed.\n");
2218                 spin_unlock_bh(&session->frwd_lock);
2219                 mutex_unlock(&session->eh_mutex);
2220                 return SUCCESS;
2221         }
2222
2223         /*
2224          * If we are not logged in or we have started a new session
2225          * then let the host reset code handle this
2226          */
2227         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN ||
2228             sc->SCp.phase != session->age) {
2229                 spin_unlock_bh(&session->frwd_lock);
2230                 mutex_unlock(&session->eh_mutex);
2231                 ISCSI_DBG_EH(session, "failing abort due to dropped "
2232                                   "session.\n");
2233                 return FAILED;
2234         }
2235
2236         conn = session->leadconn;
2237         conn->eh_abort_cnt++;
2238         age = session->age;
2239
2240         spin_lock(&session->back_lock);
2241         task = (struct iscsi_task *)sc->SCp.ptr;
2242         if (!task || !task->sc) {
2243                 /* task completed before time out */
2244                 ISCSI_DBG_EH(session, "sc completed while abort in progress\n");
2245
2246                 spin_unlock(&session->back_lock);
2247                 spin_unlock_bh(&session->frwd_lock);
2248                 mutex_unlock(&session->eh_mutex);
2249                 return SUCCESS;
2250         }
2251         ISCSI_DBG_EH(session, "aborting [sc %p itt 0x%x]\n", sc, task->itt);
2252         __iscsi_get_task(task);
2253         spin_unlock(&session->back_lock);
2254
2255         if (task->state == ISCSI_TASK_PENDING) {
2256                 fail_scsi_task(task, DID_ABORT);
2257                 goto success;
2258         }
2259
2260         /* only have one tmf outstanding at a time */
2261         if (conn->tmf_state != TMF_INITIAL)
2262                 goto failed;
2263         conn->tmf_state = TMF_QUEUED;
2264
2265         hdr = &conn->tmhdr;
2266         iscsi_prep_abort_task_pdu(task, hdr);
2267
2268         if (iscsi_exec_task_mgmt_fn(conn, hdr, age, session->abort_timeout))
2269                 goto failed;
2270
2271         switch (conn->tmf_state) {
2272         case TMF_SUCCESS:
2273                 spin_unlock_bh(&session->frwd_lock);
2274                 /*
2275                  * stop tx side incase the target had sent a abort rsp but
2276                  * the initiator was still writing out data.
2277                  */
2278                 iscsi_suspend_tx(conn);
2279                 /*
2280                  * we do not stop the recv side because targets have been
2281                  * good and have never sent us a successful tmf response
2282                  * then sent more data for the cmd.
2283                  */
2284                 spin_lock_bh(&session->frwd_lock);
2285                 fail_scsi_task(task, DID_ABORT);
2286                 conn->tmf_state = TMF_INITIAL;
2287                 memset(hdr, 0, sizeof(*hdr));
2288                 spin_unlock_bh(&session->frwd_lock);
2289                 iscsi_start_tx(conn);
2290                 goto success_unlocked;
2291         case TMF_TIMEDOUT:
2292                 spin_unlock_bh(&session->frwd_lock);
2293                 iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2294                 goto failed_unlocked;
2295         case TMF_NOT_FOUND:
2296                 if (!sc->SCp.ptr) {
2297                         conn->tmf_state = TMF_INITIAL;
2298                         memset(hdr, 0, sizeof(*hdr));
2299                         /* task completed before tmf abort response */
2300                         ISCSI_DBG_EH(session, "sc completed while abort in "
2301                                               "progress\n");
2302                         goto success;
2303                 }
2304                 fallthrough;
2305         default:
2306                 conn->tmf_state = TMF_INITIAL;
2307                 goto failed;
2308         }
2309
2310 success:
2311         spin_unlock_bh(&session->frwd_lock);
2312 success_unlocked:
2313         ISCSI_DBG_EH(session, "abort success [sc %p itt 0x%x]\n",
2314                      sc, task->itt);
2315         iscsi_put_task(task);
2316         mutex_unlock(&session->eh_mutex);
2317         return SUCCESS;
2318
2319 failed:
2320         spin_unlock_bh(&session->frwd_lock);
2321 failed_unlocked:
2322         ISCSI_DBG_EH(session, "abort failed [sc %p itt 0x%x]\n", sc,
2323                      task ? task->itt : 0);
2324         iscsi_put_task(task);
2325         mutex_unlock(&session->eh_mutex);
2326         return FAILED;
2327 }
2328 EXPORT_SYMBOL_GPL(iscsi_eh_abort);
2329
2330 static void iscsi_prep_lun_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
2331 {
2332         memset(hdr, 0, sizeof(*hdr));
2333         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2334         hdr->flags = ISCSI_TM_FUNC_LOGICAL_UNIT_RESET & ISCSI_FLAG_TM_FUNC_MASK;
2335         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2336         int_to_scsilun(sc->device->lun, &hdr->lun);
2337         hdr->rtt = RESERVED_ITT;
2338 }
2339
2340 int iscsi_eh_device_reset(struct scsi_cmnd *sc)
2341 {
2342         struct iscsi_cls_session *cls_session;
2343         struct iscsi_session *session;
2344         struct iscsi_conn *conn;
2345         struct iscsi_tm *hdr;
2346         int rc = FAILED;
2347
2348         cls_session = starget_to_session(scsi_target(sc->device));
2349         session = cls_session->dd_data;
2350
2351         ISCSI_DBG_EH(session, "LU Reset [sc %p lun %llu]\n", sc,
2352                      sc->device->lun);
2353
2354         mutex_lock(&session->eh_mutex);
2355         spin_lock_bh(&session->frwd_lock);
2356         /*
2357          * Just check if we are not logged in. We cannot check for
2358          * the phase because the reset could come from a ioctl.
2359          */
2360         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
2361                 goto unlock;
2362         conn = session->leadconn;
2363
2364         /* only have one tmf outstanding at a time */
2365         if (conn->tmf_state != TMF_INITIAL)
2366                 goto unlock;
2367         conn->tmf_state = TMF_QUEUED;
2368
2369         hdr = &conn->tmhdr;
2370         iscsi_prep_lun_reset_pdu(sc, hdr);
2371
2372         if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
2373                                     session->lu_reset_timeout)) {
2374                 rc = FAILED;
2375                 goto unlock;
2376         }
2377
2378         switch (conn->tmf_state) {
2379         case TMF_SUCCESS:
2380                 break;
2381         case TMF_TIMEDOUT:
2382                 spin_unlock_bh(&session->frwd_lock);
2383                 iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2384                 goto done;
2385         default:
2386                 conn->tmf_state = TMF_INITIAL;
2387                 goto unlock;
2388         }
2389
2390         rc = SUCCESS;
2391         spin_unlock_bh(&session->frwd_lock);
2392
2393         iscsi_suspend_tx(conn);
2394
2395         spin_lock_bh(&session->frwd_lock);
2396         memset(hdr, 0, sizeof(*hdr));
2397         fail_scsi_tasks(conn, sc->device->lun, DID_ERROR);
2398         conn->tmf_state = TMF_INITIAL;
2399         spin_unlock_bh(&session->frwd_lock);
2400
2401         iscsi_start_tx(conn);
2402         goto done;
2403
2404 unlock:
2405         spin_unlock_bh(&session->frwd_lock);
2406 done:
2407         ISCSI_DBG_EH(session, "dev reset result = %s\n",
2408                      rc == SUCCESS ? "SUCCESS" : "FAILED");
2409         mutex_unlock(&session->eh_mutex);
2410         return rc;
2411 }
2412 EXPORT_SYMBOL_GPL(iscsi_eh_device_reset);
2413
2414 void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
2415 {
2416         struct iscsi_session *session = cls_session->dd_data;
2417
2418         spin_lock_bh(&session->frwd_lock);
2419         if (session->state != ISCSI_STATE_LOGGED_IN) {
2420                 session->state = ISCSI_STATE_RECOVERY_FAILED;
2421                 if (session->leadconn)
2422                         wake_up(&session->leadconn->ehwait);
2423         }
2424         spin_unlock_bh(&session->frwd_lock);
2425 }
2426 EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
2427
2428 /**
2429  * iscsi_eh_session_reset - drop session and attempt relogin
2430  * @sc: scsi command
2431  *
2432  * This function will wait for a relogin, session termination from
2433  * userspace, or a recovery/replacement timeout.
2434  */
2435 int iscsi_eh_session_reset(struct scsi_cmnd *sc)
2436 {
2437         struct iscsi_cls_session *cls_session;
2438         struct iscsi_session *session;
2439         struct iscsi_conn *conn;
2440
2441         cls_session = starget_to_session(scsi_target(sc->device));
2442         session = cls_session->dd_data;
2443         conn = session->leadconn;
2444
2445         mutex_lock(&session->eh_mutex);
2446         spin_lock_bh(&session->frwd_lock);
2447         if (session->state == ISCSI_STATE_TERMINATE) {
2448 failed:
2449                 ISCSI_DBG_EH(session,
2450                              "failing session reset: Could not log back into "
2451                              "%s [age %d]\n", session->targetname,
2452                              session->age);
2453                 spin_unlock_bh(&session->frwd_lock);
2454                 mutex_unlock(&session->eh_mutex);
2455                 return FAILED;
2456         }
2457
2458         spin_unlock_bh(&session->frwd_lock);
2459         mutex_unlock(&session->eh_mutex);
2460         /*
2461          * we drop the lock here but the leadconn cannot be destoyed while
2462          * we are in the scsi eh
2463          */
2464         iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2465
2466         ISCSI_DBG_EH(session, "wait for relogin\n");
2467         wait_event_interruptible(conn->ehwait,
2468                                  session->state == ISCSI_STATE_TERMINATE ||
2469                                  session->state == ISCSI_STATE_LOGGED_IN ||
2470                                  session->state == ISCSI_STATE_RECOVERY_FAILED);
2471         if (signal_pending(current))
2472                 flush_signals(current);
2473
2474         mutex_lock(&session->eh_mutex);
2475         spin_lock_bh(&session->frwd_lock);
2476         if (session->state == ISCSI_STATE_LOGGED_IN) {
2477                 ISCSI_DBG_EH(session,
2478                              "session reset succeeded for %s,%s\n",
2479                              session->targetname, conn->persistent_address);
2480         } else
2481                 goto failed;
2482         spin_unlock_bh(&session->frwd_lock);
2483         mutex_unlock(&session->eh_mutex);
2484         return SUCCESS;
2485 }
2486 EXPORT_SYMBOL_GPL(iscsi_eh_session_reset);
2487
2488 static void iscsi_prep_tgt_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
2489 {
2490         memset(hdr, 0, sizeof(*hdr));
2491         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2492         hdr->flags = ISCSI_TM_FUNC_TARGET_WARM_RESET & ISCSI_FLAG_TM_FUNC_MASK;
2493         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2494         hdr->rtt = RESERVED_ITT;
2495 }
2496
2497 /**
2498  * iscsi_eh_target_reset - reset target
2499  * @sc: scsi command
2500  *
2501  * This will attempt to send a warm target reset.
2502  */
2503 static int iscsi_eh_target_reset(struct scsi_cmnd *sc)
2504 {
2505         struct iscsi_cls_session *cls_session;
2506         struct iscsi_session *session;
2507         struct iscsi_conn *conn;
2508         struct iscsi_tm *hdr;
2509         int rc = FAILED;
2510
2511         cls_session = starget_to_session(scsi_target(sc->device));
2512         session = cls_session->dd_data;
2513
2514         ISCSI_DBG_EH(session, "tgt Reset [sc %p tgt %s]\n", sc,
2515                      session->targetname);
2516
2517         mutex_lock(&session->eh_mutex);
2518         spin_lock_bh(&session->frwd_lock);
2519         /*
2520          * Just check if we are not logged in. We cannot check for
2521          * the phase because the reset could come from a ioctl.
2522          */
2523         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
2524                 goto unlock;
2525         conn = session->leadconn;
2526
2527         /* only have one tmf outstanding at a time */
2528         if (conn->tmf_state != TMF_INITIAL)
2529                 goto unlock;
2530         conn->tmf_state = TMF_QUEUED;
2531
2532         hdr = &conn->tmhdr;
2533         iscsi_prep_tgt_reset_pdu(sc, hdr);
2534
2535         if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
2536                                     session->tgt_reset_timeout)) {
2537                 rc = FAILED;
2538                 goto unlock;
2539         }
2540
2541         switch (conn->tmf_state) {
2542         case TMF_SUCCESS:
2543                 break;
2544         case TMF_TIMEDOUT:
2545                 spin_unlock_bh(&session->frwd_lock);
2546                 iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2547                 goto done;
2548         default:
2549                 conn->tmf_state = TMF_INITIAL;
2550                 goto unlock;
2551         }
2552
2553         rc = SUCCESS;
2554         spin_unlock_bh(&session->frwd_lock);
2555
2556         iscsi_suspend_tx(conn);
2557
2558         spin_lock_bh(&session->frwd_lock);
2559         memset(hdr, 0, sizeof(*hdr));
2560         fail_scsi_tasks(conn, -1, DID_ERROR);
2561         conn->tmf_state = TMF_INITIAL;
2562         spin_unlock_bh(&session->frwd_lock);
2563
2564         iscsi_start_tx(conn);
2565         goto done;
2566
2567 unlock:
2568         spin_unlock_bh(&session->frwd_lock);
2569 done:
2570         ISCSI_DBG_EH(session, "tgt %s reset result = %s\n", session->targetname,
2571                      rc == SUCCESS ? "SUCCESS" : "FAILED");
2572         mutex_unlock(&session->eh_mutex);
2573         return rc;
2574 }
2575
2576 /**
2577  * iscsi_eh_recover_target - reset target and possibly the session
2578  * @sc: scsi command
2579  *
2580  * This will attempt to send a warm target reset. If that fails,
2581  * we will escalate to ERL0 session recovery.
2582  */
2583 int iscsi_eh_recover_target(struct scsi_cmnd *sc)
2584 {
2585         int rc;
2586
2587         rc = iscsi_eh_target_reset(sc);
2588         if (rc == FAILED)
2589                 rc = iscsi_eh_session_reset(sc);
2590         return rc;
2591 }
2592 EXPORT_SYMBOL_GPL(iscsi_eh_recover_target);
2593
2594 /*
2595  * Pre-allocate a pool of @max items of @item_size. By default, the pool
2596  * should be accessed via kfifo_{get,put} on q->queue.
2597  * Optionally, the caller can obtain the array of object pointers
2598  * by passing in a non-NULL @items pointer
2599  */
2600 int
2601 iscsi_pool_init(struct iscsi_pool *q, int max, void ***items, int item_size)
2602 {
2603         int i, num_arrays = 1;
2604
2605         memset(q, 0, sizeof(*q));
2606
2607         q->max = max;
2608
2609         /* If the user passed an items pointer, he wants a copy of
2610          * the array. */
2611         if (items)
2612                 num_arrays++;
2613         q->pool = kvcalloc(num_arrays * max, sizeof(void *), GFP_KERNEL);
2614         if (q->pool == NULL)
2615                 return -ENOMEM;
2616
2617         kfifo_init(&q->queue, (void*)q->pool, max * sizeof(void*));
2618
2619         for (i = 0; i < max; i++) {
2620                 q->pool[i] = kzalloc(item_size, GFP_KERNEL);
2621                 if (q->pool[i] == NULL) {
2622                         q->max = i;
2623                         goto enomem;
2624                 }
2625                 kfifo_in(&q->queue, (void*)&q->pool[i], sizeof(void*));
2626         }
2627
2628         if (items) {
2629                 *items = q->pool + max;
2630                 memcpy(*items, q->pool, max * sizeof(void *));
2631         }
2632
2633         return 0;
2634
2635 enomem:
2636         iscsi_pool_free(q);
2637         return -ENOMEM;
2638 }
2639 EXPORT_SYMBOL_GPL(iscsi_pool_init);
2640
2641 void iscsi_pool_free(struct iscsi_pool *q)
2642 {
2643         int i;
2644
2645         for (i = 0; i < q->max; i++)
2646                 kfree(q->pool[i]);
2647         kvfree(q->pool);
2648 }
2649 EXPORT_SYMBOL_GPL(iscsi_pool_free);
2650
2651 int iscsi_host_get_max_scsi_cmds(struct Scsi_Host *shost,
2652                                  uint16_t requested_cmds_max)
2653 {
2654         int scsi_cmds, total_cmds = requested_cmds_max;
2655
2656 check:
2657         if (!total_cmds)
2658                 total_cmds = ISCSI_DEF_XMIT_CMDS_MAX;
2659         /*
2660          * The iscsi layer needs some tasks for nop handling and tmfs,
2661          * so the cmds_max must at least be greater than ISCSI_MGMT_CMDS_MAX
2662          * + 1 command for scsi IO.
2663          */
2664         if (total_cmds < ISCSI_TOTAL_CMDS_MIN) {
2665                 printk(KERN_ERR "iscsi: invalid max cmds of %d. Must be a power of two that is at least %d.\n",
2666                        total_cmds, ISCSI_TOTAL_CMDS_MIN);
2667                 return -EINVAL;
2668         }
2669
2670         if (total_cmds > ISCSI_TOTAL_CMDS_MAX) {
2671                 printk(KERN_INFO "iscsi: invalid max cmds of %d. Must be a power of 2 less than or equal to %d. Using %d.\n",
2672                        requested_cmds_max, ISCSI_TOTAL_CMDS_MAX,
2673                        ISCSI_TOTAL_CMDS_MAX);
2674                 total_cmds = ISCSI_TOTAL_CMDS_MAX;
2675         }
2676
2677         if (!is_power_of_2(total_cmds)) {
2678                 total_cmds = rounddown_pow_of_two(total_cmds);
2679                 if (total_cmds < ISCSI_TOTAL_CMDS_MIN) {
2680                         printk(KERN_ERR "iscsi: invalid max cmds of %d. Must be a power of 2 greater than %d.\n", requested_cmds_max, ISCSI_TOTAL_CMDS_MIN);
2681                         return -EINVAL;
2682                 }
2683
2684                 printk(KERN_INFO "iscsi: invalid max cmds %d. Must be a power of 2. Rounding max cmds down to %d.\n",
2685                        requested_cmds_max, total_cmds);
2686         }
2687
2688         scsi_cmds = total_cmds - ISCSI_MGMT_CMDS_MAX;
2689         if (shost->can_queue && scsi_cmds > shost->can_queue) {
2690                 total_cmds = shost->can_queue;
2691
2692                 printk(KERN_INFO "iscsi: requested max cmds %u is higher than driver limit. Using driver limit %u\n",
2693                        requested_cmds_max, shost->can_queue);
2694                 goto check;
2695         }
2696
2697         return scsi_cmds;
2698 }
2699 EXPORT_SYMBOL_GPL(iscsi_host_get_max_scsi_cmds);
2700
2701 /**
2702  * iscsi_host_add - add host to system
2703  * @shost: scsi host
2704  * @pdev: parent device
2705  *
2706  * This should be called by partial offload and software iscsi drivers
2707  * to add a host to the system.
2708  */
2709 int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev)
2710 {
2711         if (!shost->can_queue)
2712                 shost->can_queue = ISCSI_DEF_XMIT_CMDS_MAX;
2713
2714         if (!shost->cmd_per_lun)
2715                 shost->cmd_per_lun = ISCSI_DEF_CMD_PER_LUN;
2716
2717         return scsi_add_host(shost, pdev);
2718 }
2719 EXPORT_SYMBOL_GPL(iscsi_host_add);
2720
2721 /**
2722  * iscsi_host_alloc - allocate a host and driver data
2723  * @sht: scsi host template
2724  * @dd_data_size: driver host data size
2725  * @xmit_can_sleep: bool indicating if LLD will queue IO from a work queue
2726  *
2727  * This should be called by partial offload and software iscsi drivers.
2728  * To access the driver specific memory use the iscsi_host_priv() macro.
2729  */
2730 struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
2731                                    int dd_data_size, bool xmit_can_sleep)
2732 {
2733         struct Scsi_Host *shost;
2734         struct iscsi_host *ihost;
2735
2736         shost = scsi_host_alloc(sht, sizeof(struct iscsi_host) + dd_data_size);
2737         if (!shost)
2738                 return NULL;
2739         ihost = shost_priv(shost);
2740
2741         if (xmit_can_sleep) {
2742                 snprintf(ihost->workq_name, sizeof(ihost->workq_name),
2743                         "iscsi_q_%d", shost->host_no);
2744                 ihost->workq = alloc_workqueue("%s",
2745                         WQ_SYSFS | __WQ_LEGACY | WQ_MEM_RECLAIM | WQ_UNBOUND,
2746                         1, ihost->workq_name);
2747                 if (!ihost->workq)
2748                         goto free_host;
2749         }
2750
2751         spin_lock_init(&ihost->lock);
2752         ihost->state = ISCSI_HOST_SETUP;
2753         ihost->num_sessions = 0;
2754         init_waitqueue_head(&ihost->session_removal_wq);
2755         return shost;
2756
2757 free_host:
2758         scsi_host_put(shost);
2759         return NULL;
2760 }
2761 EXPORT_SYMBOL_GPL(iscsi_host_alloc);
2762
2763 static void iscsi_notify_host_removed(struct iscsi_cls_session *cls_session)
2764 {
2765         iscsi_session_failure(cls_session->dd_data, ISCSI_ERR_INVALID_HOST);
2766 }
2767
2768 /**
2769  * iscsi_host_remove - remove host and sessions
2770  * @shost: scsi host
2771  *
2772  * If there are any sessions left, this will initiate the removal and wait
2773  * for the completion.
2774  */
2775 void iscsi_host_remove(struct Scsi_Host *shost)
2776 {
2777         struct iscsi_host *ihost = shost_priv(shost);
2778         unsigned long flags;
2779
2780         spin_lock_irqsave(&ihost->lock, flags);
2781         ihost->state = ISCSI_HOST_REMOVED;
2782         spin_unlock_irqrestore(&ihost->lock, flags);
2783
2784         iscsi_host_for_each_session(shost, iscsi_notify_host_removed);
2785         wait_event_interruptible(ihost->session_removal_wq,
2786                                  ihost->num_sessions == 0);
2787         if (signal_pending(current))
2788                 flush_signals(current);
2789
2790         scsi_remove_host(shost);
2791 }
2792 EXPORT_SYMBOL_GPL(iscsi_host_remove);
2793
2794 void iscsi_host_free(struct Scsi_Host *shost)
2795 {
2796         struct iscsi_host *ihost = shost_priv(shost);
2797
2798         if (ihost->workq)
2799                 destroy_workqueue(ihost->workq);
2800
2801         kfree(ihost->netdev);
2802         kfree(ihost->hwaddress);
2803         kfree(ihost->initiatorname);
2804         scsi_host_put(shost);
2805 }
2806 EXPORT_SYMBOL_GPL(iscsi_host_free);
2807
2808 static void iscsi_host_dec_session_cnt(struct Scsi_Host *shost)
2809 {
2810         struct iscsi_host *ihost = shost_priv(shost);
2811         unsigned long flags;
2812
2813         shost = scsi_host_get(shost);
2814         if (!shost) {
2815                 printk(KERN_ERR "Invalid state. Cannot notify host removal "
2816                       "of session teardown event because host already "
2817                       "removed.\n");
2818                 return;
2819         }
2820
2821         spin_lock_irqsave(&ihost->lock, flags);
2822         ihost->num_sessions--;
2823         if (ihost->num_sessions == 0)
2824                 wake_up(&ihost->session_removal_wq);
2825         spin_unlock_irqrestore(&ihost->lock, flags);
2826         scsi_host_put(shost);
2827 }
2828
2829 /**
2830  * iscsi_session_setup - create iscsi cls session and host and session
2831  * @iscsit: iscsi transport template
2832  * @shost: scsi host
2833  * @cmds_max: session can queue
2834  * @dd_size: private driver data size, added to session allocation size
2835  * @cmd_task_size: LLD task private data size
2836  * @initial_cmdsn: initial CmdSN
2837  * @id: target ID to add to this session
2838  *
2839  * This can be used by software iscsi_transports that allocate
2840  * a session per scsi host.
2841  *
2842  * Callers should set cmds_max to the largest total numer (mgmt + scsi) of
2843  * tasks they support. The iscsi layer reserves ISCSI_MGMT_CMDS_MAX tasks
2844  * for nop handling and login/logout requests.
2845  */
2846 struct iscsi_cls_session *
2847 iscsi_session_setup(struct iscsi_transport *iscsit, struct Scsi_Host *shost,
2848                     uint16_t cmds_max, int dd_size, int cmd_task_size,
2849                     uint32_t initial_cmdsn, unsigned int id)
2850 {
2851         struct iscsi_host *ihost = shost_priv(shost);
2852         struct iscsi_session *session;
2853         struct iscsi_cls_session *cls_session;
2854         int cmd_i, scsi_cmds;
2855         unsigned long flags;
2856
2857         spin_lock_irqsave(&ihost->lock, flags);
2858         if (ihost->state == ISCSI_HOST_REMOVED) {
2859                 spin_unlock_irqrestore(&ihost->lock, flags);
2860                 return NULL;
2861         }
2862         ihost->num_sessions++;
2863         spin_unlock_irqrestore(&ihost->lock, flags);
2864
2865         scsi_cmds = iscsi_host_get_max_scsi_cmds(shost, cmds_max);
2866         if (scsi_cmds < 0)
2867                 goto dec_session_count;
2868
2869         cls_session = iscsi_alloc_session(shost, iscsit,
2870                                           sizeof(struct iscsi_session) +
2871                                           dd_size);
2872         if (!cls_session)
2873                 goto dec_session_count;
2874         session = cls_session->dd_data;
2875         session->cls_session = cls_session;
2876         session->host = shost;
2877         session->state = ISCSI_STATE_FREE;
2878         session->fast_abort = 1;
2879         session->tgt_reset_timeout = 30;
2880         session->lu_reset_timeout = 15;
2881         session->abort_timeout = 10;
2882         session->scsi_cmds_max = scsi_cmds;
2883         session->cmds_max = scsi_cmds + ISCSI_MGMT_CMDS_MAX;
2884         session->queued_cmdsn = session->cmdsn = initial_cmdsn;
2885         session->exp_cmdsn = initial_cmdsn + 1;
2886         session->max_cmdsn = initial_cmdsn + 1;
2887         session->max_r2t = 1;
2888         session->tt = iscsit;
2889         session->dd_data = cls_session->dd_data + sizeof(*session);
2890
2891         mutex_init(&session->eh_mutex);
2892         spin_lock_init(&session->frwd_lock);
2893         spin_lock_init(&session->back_lock);
2894
2895         /* initialize SCSI PDU commands pool */
2896         if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
2897                             (void***)&session->cmds,
2898                             cmd_task_size + sizeof(struct iscsi_task)))
2899                 goto cmdpool_alloc_fail;
2900
2901         /* pre-format cmds pool with ITT */
2902         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
2903                 struct iscsi_task *task = session->cmds[cmd_i];
2904
2905                 if (cmd_task_size)
2906                         task->dd_data = &task[1];
2907                 task->itt = cmd_i;
2908                 task->state = ISCSI_TASK_FREE;
2909                 INIT_LIST_HEAD(&task->running);
2910         }
2911
2912         if (!try_module_get(iscsit->owner))
2913                 goto module_get_fail;
2914
2915         if (iscsi_add_session(cls_session, id))
2916                 goto cls_session_fail;
2917
2918         return cls_session;
2919
2920 cls_session_fail:
2921         module_put(iscsit->owner);
2922 module_get_fail:
2923         iscsi_pool_free(&session->cmdpool);
2924 cmdpool_alloc_fail:
2925         iscsi_free_session(cls_session);
2926 dec_session_count:
2927         iscsi_host_dec_session_cnt(shost);
2928         return NULL;
2929 }
2930 EXPORT_SYMBOL_GPL(iscsi_session_setup);
2931
2932 /**
2933  * iscsi_session_teardown - destroy session, host, and cls_session
2934  * @cls_session: iscsi session
2935  */
2936 void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
2937 {
2938         struct iscsi_session *session = cls_session->dd_data;
2939         struct module *owner = cls_session->transport->owner;
2940         struct Scsi_Host *shost = session->host;
2941
2942         iscsi_pool_free(&session->cmdpool);
2943
2944         iscsi_remove_session(cls_session);
2945
2946         kfree(session->password);
2947         kfree(session->password_in);
2948         kfree(session->username);
2949         kfree(session->username_in);
2950         kfree(session->targetname);
2951         kfree(session->targetalias);
2952         kfree(session->initiatorname);
2953         kfree(session->boot_root);
2954         kfree(session->boot_nic);
2955         kfree(session->boot_target);
2956         kfree(session->ifacename);
2957         kfree(session->portal_type);
2958         kfree(session->discovery_parent_type);
2959
2960         iscsi_free_session(cls_session);
2961
2962         iscsi_host_dec_session_cnt(shost);
2963         module_put(owner);
2964 }
2965 EXPORT_SYMBOL_GPL(iscsi_session_teardown);
2966
2967 /**
2968  * iscsi_conn_setup - create iscsi_cls_conn and iscsi_conn
2969  * @cls_session: iscsi_cls_session
2970  * @dd_size: private driver data size
2971  * @conn_idx: cid
2972  */
2973 struct iscsi_cls_conn *
2974 iscsi_conn_setup(struct iscsi_cls_session *cls_session, int dd_size,
2975                  uint32_t conn_idx)
2976 {
2977         struct iscsi_session *session = cls_session->dd_data;
2978         struct iscsi_conn *conn;
2979         struct iscsi_cls_conn *cls_conn;
2980         char *data;
2981
2982         cls_conn = iscsi_create_conn(cls_session, sizeof(*conn) + dd_size,
2983                                      conn_idx);
2984         if (!cls_conn)
2985                 return NULL;
2986         conn = cls_conn->dd_data;
2987         memset(conn, 0, sizeof(*conn) + dd_size);
2988
2989         conn->dd_data = cls_conn->dd_data + sizeof(*conn);
2990         conn->session = session;
2991         conn->cls_conn = cls_conn;
2992         conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
2993         conn->id = conn_idx;
2994         conn->exp_statsn = 0;
2995         conn->tmf_state = TMF_INITIAL;
2996
2997         timer_setup(&conn->transport_timer, iscsi_check_transport_timeouts, 0);
2998
2999         INIT_LIST_HEAD(&conn->mgmtqueue);
3000         INIT_LIST_HEAD(&conn->cmdqueue);
3001         INIT_LIST_HEAD(&conn->requeue);
3002         INIT_WORK(&conn->xmitwork, iscsi_xmitworker);
3003
3004         /* allocate login_task used for the login/text sequences */
3005         spin_lock_bh(&session->frwd_lock);
3006         if (!kfifo_out(&session->cmdpool.queue,
3007                          (void*)&conn->login_task,
3008                          sizeof(void*))) {
3009                 spin_unlock_bh(&session->frwd_lock);
3010                 goto login_task_alloc_fail;
3011         }
3012         spin_unlock_bh(&session->frwd_lock);
3013
3014         data = (char *) __get_free_pages(GFP_KERNEL,
3015                                          get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
3016         if (!data)
3017                 goto login_task_data_alloc_fail;
3018         conn->login_task->data = conn->data = data;
3019
3020         timer_setup(&conn->tmf_timer, iscsi_tmf_timedout, 0);
3021         init_waitqueue_head(&conn->ehwait);
3022
3023         return cls_conn;
3024
3025 login_task_data_alloc_fail:
3026         kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
3027                     sizeof(void*));
3028 login_task_alloc_fail:
3029         iscsi_destroy_conn(cls_conn);
3030         return NULL;
3031 }
3032 EXPORT_SYMBOL_GPL(iscsi_conn_setup);
3033
3034 /**
3035  * iscsi_conn_teardown - teardown iscsi connection
3036  * @cls_conn: iscsi class connection
3037  *
3038  * TODO: we may need to make this into a two step process
3039  * like scsi-mls remove + put host
3040  */
3041 void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
3042 {
3043         struct iscsi_conn *conn = cls_conn->dd_data;
3044         struct iscsi_session *session = conn->session;
3045
3046         del_timer_sync(&conn->transport_timer);
3047
3048         mutex_lock(&session->eh_mutex);
3049         spin_lock_bh(&session->frwd_lock);
3050         conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
3051         if (session->leadconn == conn) {
3052                 /*
3053                  * leading connection? then give up on recovery.
3054                  */
3055                 session->state = ISCSI_STATE_TERMINATE;
3056                 wake_up(&conn->ehwait);
3057         }
3058         spin_unlock_bh(&session->frwd_lock);
3059
3060         /* flush queued up work because we free the connection below */
3061         iscsi_suspend_tx(conn);
3062
3063         spin_lock_bh(&session->frwd_lock);
3064         free_pages((unsigned long) conn->data,
3065                    get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
3066         kfree(conn->persistent_address);
3067         kfree(conn->local_ipaddr);
3068         /* regular RX path uses back_lock */
3069         spin_lock_bh(&session->back_lock);
3070         kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
3071                     sizeof(void*));
3072         spin_unlock_bh(&session->back_lock);
3073         if (session->leadconn == conn)
3074                 session->leadconn = NULL;
3075         spin_unlock_bh(&session->frwd_lock);
3076         mutex_unlock(&session->eh_mutex);
3077
3078         iscsi_destroy_conn(cls_conn);
3079 }
3080 EXPORT_SYMBOL_GPL(iscsi_conn_teardown);
3081
3082 int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
3083 {
3084         struct iscsi_conn *conn = cls_conn->dd_data;
3085         struct iscsi_session *session = conn->session;
3086
3087         if (!session) {
3088                 iscsi_conn_printk(KERN_ERR, conn,
3089                                   "can't start unbound connection\n");
3090                 return -EPERM;
3091         }
3092
3093         if ((session->imm_data_en || !session->initial_r2t_en) &&
3094              session->first_burst > session->max_burst) {
3095                 iscsi_conn_printk(KERN_INFO, conn, "invalid burst lengths: "
3096                                   "first_burst %d max_burst %d\n",
3097                                   session->first_burst, session->max_burst);
3098                 return -EINVAL;
3099         }
3100
3101         if (conn->ping_timeout && !conn->recv_timeout) {
3102                 iscsi_conn_printk(KERN_ERR, conn, "invalid recv timeout of "
3103                                   "zero. Using 5 seconds\n.");
3104                 conn->recv_timeout = 5;
3105         }
3106
3107         if (conn->recv_timeout && !conn->ping_timeout) {
3108                 iscsi_conn_printk(KERN_ERR, conn, "invalid ping timeout of "
3109                                   "zero. Using 5 seconds.\n");
3110                 conn->ping_timeout = 5;
3111         }
3112
3113         spin_lock_bh(&session->frwd_lock);
3114         conn->c_stage = ISCSI_CONN_STARTED;
3115         session->state = ISCSI_STATE_LOGGED_IN;
3116         session->queued_cmdsn = session->cmdsn;
3117
3118         conn->last_recv = jiffies;
3119         conn->last_ping = jiffies;
3120         if (conn->recv_timeout && conn->ping_timeout)
3121                 mod_timer(&conn->transport_timer,
3122                           jiffies + (conn->recv_timeout * HZ));
3123
3124         switch(conn->stop_stage) {
3125         case STOP_CONN_RECOVER:
3126                 /*
3127                  * unblock eh_abort() if it is blocked. re-try all
3128                  * commands after successful recovery
3129                  */
3130                 conn->stop_stage = 0;
3131                 conn->tmf_state = TMF_INITIAL;
3132                 session->age++;
3133                 if (session->age == 16)
3134                         session->age = 0;
3135                 break;
3136         case STOP_CONN_TERM:
3137                 conn->stop_stage = 0;
3138                 break;
3139         default:
3140                 break;
3141         }
3142         spin_unlock_bh(&session->frwd_lock);
3143
3144         iscsi_unblock_session(session->cls_session);
3145         wake_up(&conn->ehwait);
3146         return 0;
3147 }
3148 EXPORT_SYMBOL_GPL(iscsi_conn_start);
3149
3150 static void
3151 fail_mgmt_tasks(struct iscsi_session *session, struct iscsi_conn *conn)
3152 {
3153         struct iscsi_task *task;
3154         int i, state;
3155
3156         for (i = 0; i < conn->session->cmds_max; i++) {
3157                 task = conn->session->cmds[i];
3158                 if (task->sc)
3159                         continue;
3160
3161                 if (task->state == ISCSI_TASK_FREE)
3162                         continue;
3163
3164                 ISCSI_DBG_SESSION(conn->session,
3165                                   "failing mgmt itt 0x%x state %d\n",
3166                                   task->itt, task->state);
3167
3168                 spin_lock_bh(&session->back_lock);
3169                 if (cleanup_queued_task(task)) {
3170                         spin_unlock_bh(&session->back_lock);
3171                         continue;
3172                 }
3173
3174                 state = ISCSI_TASK_ABRT_SESS_RECOV;
3175                 if (task->state == ISCSI_TASK_PENDING)
3176                         state = ISCSI_TASK_COMPLETED;
3177                 iscsi_complete_task(task, state);
3178                 spin_unlock_bh(&session->back_lock);
3179         }
3180 }
3181
3182 void iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
3183 {
3184         struct iscsi_conn *conn = cls_conn->dd_data;
3185         struct iscsi_session *session = conn->session;
3186         int old_stop_stage;
3187
3188         mutex_lock(&session->eh_mutex);
3189         spin_lock_bh(&session->frwd_lock);
3190         if (conn->stop_stage == STOP_CONN_TERM) {
3191                 spin_unlock_bh(&session->frwd_lock);
3192                 mutex_unlock(&session->eh_mutex);
3193                 return;
3194         }
3195
3196         /*
3197          * When this is called for the in_login state, we only want to clean
3198          * up the login task and connection. We do not need to block and set
3199          * the recovery state again
3200          */
3201         if (flag == STOP_CONN_TERM)
3202                 session->state = ISCSI_STATE_TERMINATE;
3203         else if (conn->stop_stage != STOP_CONN_RECOVER)
3204                 session->state = ISCSI_STATE_IN_RECOVERY;
3205
3206         old_stop_stage = conn->stop_stage;
3207         conn->stop_stage = flag;
3208         spin_unlock_bh(&session->frwd_lock);
3209
3210         del_timer_sync(&conn->transport_timer);
3211         iscsi_suspend_tx(conn);
3212
3213         spin_lock_bh(&session->frwd_lock);
3214         conn->c_stage = ISCSI_CONN_STOPPED;
3215         spin_unlock_bh(&session->frwd_lock);
3216
3217         /*
3218          * for connection level recovery we should not calculate
3219          * header digest. conn->hdr_size used for optimization
3220          * in hdr_extract() and will be re-negotiated at
3221          * set_param() time.
3222          */
3223         if (flag == STOP_CONN_RECOVER) {
3224                 conn->hdrdgst_en = 0;
3225                 conn->datadgst_en = 0;
3226                 if (session->state == ISCSI_STATE_IN_RECOVERY &&
3227                     old_stop_stage != STOP_CONN_RECOVER) {
3228                         ISCSI_DBG_SESSION(session, "blocking session\n");
3229                         iscsi_block_session(session->cls_session);
3230                 }
3231         }
3232
3233         /*
3234          * flush queues.
3235          */
3236         spin_lock_bh(&session->frwd_lock);
3237         fail_scsi_tasks(conn, -1, DID_TRANSPORT_DISRUPTED);
3238         fail_mgmt_tasks(session, conn);
3239         memset(&conn->tmhdr, 0, sizeof(conn->tmhdr));
3240         spin_unlock_bh(&session->frwd_lock);
3241         mutex_unlock(&session->eh_mutex);
3242 }
3243 EXPORT_SYMBOL_GPL(iscsi_conn_stop);
3244
3245 int iscsi_conn_bind(struct iscsi_cls_session *cls_session,
3246                     struct iscsi_cls_conn *cls_conn, int is_leading)
3247 {
3248         struct iscsi_session *session = cls_session->dd_data;
3249         struct iscsi_conn *conn = cls_conn->dd_data;
3250
3251         spin_lock_bh(&session->frwd_lock);
3252         if (is_leading)
3253                 session->leadconn = conn;
3254         spin_unlock_bh(&session->frwd_lock);
3255
3256         /*
3257          * The target could have reduced it's window size between logins, so
3258          * we have to reset max/exp cmdsn so we can see the new values.
3259          */
3260         spin_lock_bh(&session->back_lock);
3261         session->max_cmdsn = session->exp_cmdsn = session->cmdsn + 1;
3262         spin_unlock_bh(&session->back_lock);
3263         /*
3264          * Unblock xmitworker(), Login Phase will pass through.
3265          */
3266         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
3267         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
3268         return 0;
3269 }
3270 EXPORT_SYMBOL_GPL(iscsi_conn_bind);
3271
3272 int iscsi_switch_str_param(char **param, char *new_val_buf)
3273 {
3274         char *new_val;
3275
3276         if (*param) {
3277                 if (!strcmp(*param, new_val_buf))
3278                         return 0;
3279         }
3280
3281         new_val = kstrdup(new_val_buf, GFP_NOIO);
3282         if (!new_val)
3283                 return -ENOMEM;
3284
3285         kfree(*param);
3286         *param = new_val;
3287         return 0;
3288 }
3289 EXPORT_SYMBOL_GPL(iscsi_switch_str_param);
3290
3291 int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
3292                     enum iscsi_param param, char *buf, int buflen)
3293 {
3294         struct iscsi_conn *conn = cls_conn->dd_data;
3295         struct iscsi_session *session = conn->session;
3296         int val;
3297
3298         switch(param) {
3299         case ISCSI_PARAM_FAST_ABORT:
3300                 sscanf(buf, "%d", &session->fast_abort);
3301                 break;
3302         case ISCSI_PARAM_ABORT_TMO:
3303                 sscanf(buf, "%d", &session->abort_timeout);
3304                 break;
3305         case ISCSI_PARAM_LU_RESET_TMO:
3306                 sscanf(buf, "%d", &session->lu_reset_timeout);
3307                 break;
3308         case ISCSI_PARAM_TGT_RESET_TMO:
3309                 sscanf(buf, "%d", &session->tgt_reset_timeout);
3310                 break;
3311         case ISCSI_PARAM_PING_TMO:
3312                 sscanf(buf, "%d", &conn->ping_timeout);
3313                 break;
3314         case ISCSI_PARAM_RECV_TMO:
3315                 sscanf(buf, "%d", &conn->recv_timeout);
3316                 break;
3317         case ISCSI_PARAM_MAX_RECV_DLENGTH:
3318                 sscanf(buf, "%d", &conn->max_recv_dlength);
3319                 break;
3320         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3321                 sscanf(buf, "%d", &conn->max_xmit_dlength);
3322                 break;
3323         case ISCSI_PARAM_HDRDGST_EN:
3324                 sscanf(buf, "%d", &conn->hdrdgst_en);
3325                 break;
3326         case ISCSI_PARAM_DATADGST_EN:
3327                 sscanf(buf, "%d", &conn->datadgst_en);
3328                 break;
3329         case ISCSI_PARAM_INITIAL_R2T_EN:
3330                 sscanf(buf, "%d", &session->initial_r2t_en);
3331                 break;
3332         case ISCSI_PARAM_MAX_R2T:
3333                 sscanf(buf, "%hu", &session->max_r2t);
3334                 break;
3335         case ISCSI_PARAM_IMM_DATA_EN:
3336                 sscanf(buf, "%d", &session->imm_data_en);
3337                 break;
3338         case ISCSI_PARAM_FIRST_BURST:
3339                 sscanf(buf, "%d", &session->first_burst);
3340                 break;
3341         case ISCSI_PARAM_MAX_BURST:
3342                 sscanf(buf, "%d", &session->max_burst);
3343                 break;
3344         case ISCSI_PARAM_PDU_INORDER_EN:
3345                 sscanf(buf, "%d", &session->pdu_inorder_en);
3346                 break;
3347         case ISCSI_PARAM_DATASEQ_INORDER_EN:
3348                 sscanf(buf, "%d", &session->dataseq_inorder_en);
3349                 break;
3350         case ISCSI_PARAM_ERL:
3351                 sscanf(buf, "%d", &session->erl);
3352                 break;
3353         case ISCSI_PARAM_EXP_STATSN:
3354                 sscanf(buf, "%u", &conn->exp_statsn);
3355                 break;
3356         case ISCSI_PARAM_USERNAME:
3357                 return iscsi_switch_str_param(&session->username, buf);
3358         case ISCSI_PARAM_USERNAME_IN:
3359                 return iscsi_switch_str_param(&session->username_in, buf);
3360         case ISCSI_PARAM_PASSWORD:
3361                 return iscsi_switch_str_param(&session->password, buf);
3362         case ISCSI_PARAM_PASSWORD_IN:
3363                 return iscsi_switch_str_param(&session->password_in, buf);
3364         case ISCSI_PARAM_TARGET_NAME:
3365                 return iscsi_switch_str_param(&session->targetname, buf);
3366         case ISCSI_PARAM_TARGET_ALIAS:
3367                 return iscsi_switch_str_param(&session->targetalias, buf);
3368         case ISCSI_PARAM_TPGT:
3369                 sscanf(buf, "%d", &session->tpgt);
3370                 break;
3371         case ISCSI_PARAM_PERSISTENT_PORT:
3372                 sscanf(buf, "%d", &conn->persistent_port);
3373                 break;
3374         case ISCSI_PARAM_PERSISTENT_ADDRESS:
3375                 return iscsi_switch_str_param(&conn->persistent_address, buf);
3376         case ISCSI_PARAM_IFACE_NAME:
3377                 return iscsi_switch_str_param(&session->ifacename, buf);
3378         case ISCSI_PARAM_INITIATOR_NAME:
3379                 return iscsi_switch_str_param(&session->initiatorname, buf);
3380         case ISCSI_PARAM_BOOT_ROOT:
3381                 return iscsi_switch_str_param(&session->boot_root, buf);
3382         case ISCSI_PARAM_BOOT_NIC:
3383                 return iscsi_switch_str_param(&session->boot_nic, buf);
3384         case ISCSI_PARAM_BOOT_TARGET:
3385                 return iscsi_switch_str_param(&session->boot_target, buf);
3386         case ISCSI_PARAM_PORTAL_TYPE:
3387                 return iscsi_switch_str_param(&session->portal_type, buf);
3388         case ISCSI_PARAM_DISCOVERY_PARENT_TYPE:
3389                 return iscsi_switch_str_param(&session->discovery_parent_type,
3390                                               buf);
3391         case ISCSI_PARAM_DISCOVERY_SESS:
3392                 sscanf(buf, "%d", &val);
3393                 session->discovery_sess = !!val;
3394                 break;
3395         case ISCSI_PARAM_LOCAL_IPADDR:
3396                 return iscsi_switch_str_param(&conn->local_ipaddr, buf);
3397         default:
3398                 return -ENOSYS;
3399         }
3400
3401         return 0;
3402 }
3403 EXPORT_SYMBOL_GPL(iscsi_set_param);
3404
3405 int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
3406                             enum iscsi_param param, char *buf)
3407 {
3408         struct iscsi_session *session = cls_session->dd_data;
3409         int len;
3410
3411         switch(param) {
3412         case ISCSI_PARAM_FAST_ABORT:
3413                 len = sysfs_emit(buf, "%d\n", session->fast_abort);
3414                 break;
3415         case ISCSI_PARAM_ABORT_TMO:
3416                 len = sysfs_emit(buf, "%d\n", session->abort_timeout);
3417                 break;
3418         case ISCSI_PARAM_LU_RESET_TMO:
3419                 len = sysfs_emit(buf, "%d\n", session->lu_reset_timeout);
3420                 break;
3421         case ISCSI_PARAM_TGT_RESET_TMO:
3422                 len = sysfs_emit(buf, "%d\n", session->tgt_reset_timeout);
3423                 break;
3424         case ISCSI_PARAM_INITIAL_R2T_EN:
3425                 len = sysfs_emit(buf, "%d\n", session->initial_r2t_en);
3426                 break;
3427         case ISCSI_PARAM_MAX_R2T:
3428                 len = sysfs_emit(buf, "%hu\n", session->max_r2t);
3429                 break;
3430         case ISCSI_PARAM_IMM_DATA_EN:
3431                 len = sysfs_emit(buf, "%d\n", session->imm_data_en);
3432                 break;
3433         case ISCSI_PARAM_FIRST_BURST:
3434                 len = sysfs_emit(buf, "%u\n", session->first_burst);
3435                 break;
3436         case ISCSI_PARAM_MAX_BURST:
3437                 len = sysfs_emit(buf, "%u\n", session->max_burst);
3438                 break;
3439         case ISCSI_PARAM_PDU_INORDER_EN:
3440                 len = sysfs_emit(buf, "%d\n", session->pdu_inorder_en);
3441                 break;
3442         case ISCSI_PARAM_DATASEQ_INORDER_EN:
3443                 len = sysfs_emit(buf, "%d\n", session->dataseq_inorder_en);
3444                 break;
3445         case ISCSI_PARAM_DEF_TASKMGMT_TMO:
3446                 len = sysfs_emit(buf, "%d\n", session->def_taskmgmt_tmo);
3447                 break;
3448         case ISCSI_PARAM_ERL:
3449                 len = sysfs_emit(buf, "%d\n", session->erl);
3450                 break;
3451         case ISCSI_PARAM_TARGET_NAME:
3452                 len = sysfs_emit(buf, "%s\n", session->targetname);
3453                 break;
3454         case ISCSI_PARAM_TARGET_ALIAS:
3455                 len = sysfs_emit(buf, "%s\n", session->targetalias);
3456                 break;
3457         case ISCSI_PARAM_TPGT:
3458                 len = sysfs_emit(buf, "%d\n", session->tpgt);
3459                 break;
3460         case ISCSI_PARAM_USERNAME:
3461                 len = sysfs_emit(buf, "%s\n", session->username);
3462                 break;
3463         case ISCSI_PARAM_USERNAME_IN:
3464                 len = sysfs_emit(buf, "%s\n", session->username_in);
3465                 break;
3466         case ISCSI_PARAM_PASSWORD:
3467                 len = sysfs_emit(buf, "%s\n", session->password);
3468                 break;
3469         case ISCSI_PARAM_PASSWORD_IN:
3470                 len = sysfs_emit(buf, "%s\n", session->password_in);
3471                 break;
3472         case ISCSI_PARAM_IFACE_NAME:
3473                 len = sysfs_emit(buf, "%s\n", session->ifacename);
3474                 break;
3475         case ISCSI_PARAM_INITIATOR_NAME:
3476                 len = sysfs_emit(buf, "%s\n", session->initiatorname);
3477                 break;
3478         case ISCSI_PARAM_BOOT_ROOT:
3479                 len = sysfs_emit(buf, "%s\n", session->boot_root);
3480                 break;
3481         case ISCSI_PARAM_BOOT_NIC:
3482                 len = sysfs_emit(buf, "%s\n", session->boot_nic);
3483                 break;
3484         case ISCSI_PARAM_BOOT_TARGET:
3485                 len = sysfs_emit(buf, "%s\n", session->boot_target);
3486                 break;
3487         case ISCSI_PARAM_AUTO_SND_TGT_DISABLE:
3488                 len = sysfs_emit(buf, "%u\n", session->auto_snd_tgt_disable);
3489                 break;
3490         case ISCSI_PARAM_DISCOVERY_SESS:
3491                 len = sysfs_emit(buf, "%u\n", session->discovery_sess);
3492                 break;
3493         case ISCSI_PARAM_PORTAL_TYPE:
3494                 len = sysfs_emit(buf, "%s\n", session->portal_type);
3495                 break;
3496         case ISCSI_PARAM_CHAP_AUTH_EN:
3497                 len = sysfs_emit(buf, "%u\n", session->chap_auth_en);
3498                 break;
3499         case ISCSI_PARAM_DISCOVERY_LOGOUT_EN:
3500                 len = sysfs_emit(buf, "%u\n", session->discovery_logout_en);
3501                 break;
3502         case ISCSI_PARAM_BIDI_CHAP_EN:
3503                 len = sysfs_emit(buf, "%u\n", session->bidi_chap_en);
3504                 break;
3505         case ISCSI_PARAM_DISCOVERY_AUTH_OPTIONAL:
3506                 len = sysfs_emit(buf, "%u\n", session->discovery_auth_optional);
3507                 break;
3508         case ISCSI_PARAM_DEF_TIME2WAIT:
3509                 len = sysfs_emit(buf, "%d\n", session->time2wait);
3510                 break;
3511         case ISCSI_PARAM_DEF_TIME2RETAIN:
3512                 len = sysfs_emit(buf, "%d\n", session->time2retain);
3513                 break;
3514         case ISCSI_PARAM_TSID:
3515                 len = sysfs_emit(buf, "%u\n", session->tsid);
3516                 break;
3517         case ISCSI_PARAM_ISID:
3518                 len = sysfs_emit(buf, "%02x%02x%02x%02x%02x%02x\n",
3519                               session->isid[0], session->isid[1],
3520                               session->isid[2], session->isid[3],
3521                               session->isid[4], session->isid[5]);
3522                 break;
3523         case ISCSI_PARAM_DISCOVERY_PARENT_IDX:
3524                 len = sysfs_emit(buf, "%u\n", session->discovery_parent_idx);
3525                 break;
3526         case ISCSI_PARAM_DISCOVERY_PARENT_TYPE:
3527                 if (session->discovery_parent_type)
3528                         len = sysfs_emit(buf, "%s\n",
3529                                       session->discovery_parent_type);
3530                 else
3531                         len = sysfs_emit(buf, "\n");
3532                 break;
3533         default:
3534                 return -ENOSYS;
3535         }
3536
3537         return len;
3538 }
3539 EXPORT_SYMBOL_GPL(iscsi_session_get_param);
3540
3541 int iscsi_conn_get_addr_param(struct sockaddr_storage *addr,
3542                               enum iscsi_param param, char *buf)
3543 {
3544         struct sockaddr_in6 *sin6 = NULL;
3545         struct sockaddr_in *sin = NULL;
3546         int len;
3547
3548         switch (addr->ss_family) {
3549         case AF_INET:
3550                 sin = (struct sockaddr_in *)addr;
3551                 break;
3552         case AF_INET6:
3553                 sin6 = (struct sockaddr_in6 *)addr;
3554                 break;
3555         default:
3556                 return -EINVAL;
3557         }
3558
3559         switch (param) {
3560         case ISCSI_PARAM_CONN_ADDRESS:
3561         case ISCSI_HOST_PARAM_IPADDRESS:
3562                 if (sin)
3563                         len = sysfs_emit(buf, "%pI4\n", &sin->sin_addr.s_addr);
3564                 else
3565                         len = sysfs_emit(buf, "%pI6\n", &sin6->sin6_addr);
3566                 break;
3567         case ISCSI_PARAM_CONN_PORT:
3568         case ISCSI_PARAM_LOCAL_PORT:
3569                 if (sin)
3570                         len = sysfs_emit(buf, "%hu\n", be16_to_cpu(sin->sin_port));
3571                 else
3572                         len = sysfs_emit(buf, "%hu\n",
3573                                       be16_to_cpu(sin6->sin6_port));
3574                 break;
3575         default:
3576                 return -EINVAL;
3577         }
3578
3579         return len;
3580 }
3581 EXPORT_SYMBOL_GPL(iscsi_conn_get_addr_param);
3582
3583 int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
3584                          enum iscsi_param param, char *buf)
3585 {
3586         struct iscsi_conn *conn = cls_conn->dd_data;
3587         int len;
3588
3589         switch(param) {
3590         case ISCSI_PARAM_PING_TMO:
3591                 len = sysfs_emit(buf, "%u\n", conn->ping_timeout);
3592                 break;
3593         case ISCSI_PARAM_RECV_TMO:
3594                 len = sysfs_emit(buf, "%u\n", conn->recv_timeout);
3595                 break;
3596         case ISCSI_PARAM_MAX_RECV_DLENGTH:
3597                 len = sysfs_emit(buf, "%u\n", conn->max_recv_dlength);
3598                 break;
3599         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3600                 len = sysfs_emit(buf, "%u\n", conn->max_xmit_dlength);
3601                 break;
3602         case ISCSI_PARAM_HDRDGST_EN:
3603                 len = sysfs_emit(buf, "%d\n", conn->hdrdgst_en);
3604                 break;
3605         case ISCSI_PARAM_DATADGST_EN:
3606                 len = sysfs_emit(buf, "%d\n", conn->datadgst_en);
3607                 break;
3608         case ISCSI_PARAM_IFMARKER_EN:
3609                 len = sysfs_emit(buf, "%d\n", conn->ifmarker_en);
3610                 break;
3611         case ISCSI_PARAM_OFMARKER_EN:
3612                 len = sysfs_emit(buf, "%d\n", conn->ofmarker_en);
3613                 break;
3614         case ISCSI_PARAM_EXP_STATSN:
3615                 len = sysfs_emit(buf, "%u\n", conn->exp_statsn);
3616                 break;
3617         case ISCSI_PARAM_PERSISTENT_PORT:
3618                 len = sysfs_emit(buf, "%d\n", conn->persistent_port);
3619                 break;
3620         case ISCSI_PARAM_PERSISTENT_ADDRESS:
3621                 len = sysfs_emit(buf, "%s\n", conn->persistent_address);
3622                 break;
3623         case ISCSI_PARAM_STATSN:
3624                 len = sysfs_emit(buf, "%u\n", conn->statsn);
3625                 break;
3626         case ISCSI_PARAM_MAX_SEGMENT_SIZE:
3627                 len = sysfs_emit(buf, "%u\n", conn->max_segment_size);
3628                 break;
3629         case ISCSI_PARAM_KEEPALIVE_TMO:
3630                 len = sysfs_emit(buf, "%u\n", conn->keepalive_tmo);
3631                 break;
3632         case ISCSI_PARAM_LOCAL_PORT:
3633                 len = sysfs_emit(buf, "%u\n", conn->local_port);
3634                 break;
3635         case ISCSI_PARAM_TCP_TIMESTAMP_STAT:
3636                 len = sysfs_emit(buf, "%u\n", conn->tcp_timestamp_stat);
3637                 break;
3638         case ISCSI_PARAM_TCP_NAGLE_DISABLE:
3639                 len = sysfs_emit(buf, "%u\n", conn->tcp_nagle_disable);
3640                 break;
3641         case ISCSI_PARAM_TCP_WSF_DISABLE:
3642                 len = sysfs_emit(buf, "%u\n", conn->tcp_wsf_disable);
3643                 break;
3644         case ISCSI_PARAM_TCP_TIMER_SCALE:
3645                 len = sysfs_emit(buf, "%u\n", conn->tcp_timer_scale);
3646                 break;
3647         case ISCSI_PARAM_TCP_TIMESTAMP_EN:
3648                 len = sysfs_emit(buf, "%u\n", conn->tcp_timestamp_en);
3649                 break;
3650         case ISCSI_PARAM_IP_FRAGMENT_DISABLE:
3651                 len = sysfs_emit(buf, "%u\n", conn->fragment_disable);
3652                 break;
3653         case ISCSI_PARAM_IPV4_TOS:
3654                 len = sysfs_emit(buf, "%u\n", conn->ipv4_tos);
3655                 break;
3656         case ISCSI_PARAM_IPV6_TC:
3657                 len = sysfs_emit(buf, "%u\n", conn->ipv6_traffic_class);
3658                 break;
3659         case ISCSI_PARAM_IPV6_FLOW_LABEL:
3660                 len = sysfs_emit(buf, "%u\n", conn->ipv6_flow_label);
3661                 break;
3662         case ISCSI_PARAM_IS_FW_ASSIGNED_IPV6:
3663                 len = sysfs_emit(buf, "%u\n", conn->is_fw_assigned_ipv6);
3664                 break;
3665         case ISCSI_PARAM_TCP_XMIT_WSF:
3666                 len = sysfs_emit(buf, "%u\n", conn->tcp_xmit_wsf);
3667                 break;
3668         case ISCSI_PARAM_TCP_RECV_WSF:
3669                 len = sysfs_emit(buf, "%u\n", conn->tcp_recv_wsf);
3670                 break;
3671         case ISCSI_PARAM_LOCAL_IPADDR:
3672                 len = sysfs_emit(buf, "%s\n", conn->local_ipaddr);
3673                 break;
3674         default:
3675                 return -ENOSYS;
3676         }
3677
3678         return len;
3679 }
3680 EXPORT_SYMBOL_GPL(iscsi_conn_get_param);
3681
3682 int iscsi_host_get_param(struct Scsi_Host *shost, enum iscsi_host_param param,
3683                          char *buf)
3684 {
3685         struct iscsi_host *ihost = shost_priv(shost);
3686         int len;
3687
3688         switch (param) {
3689         case ISCSI_HOST_PARAM_NETDEV_NAME:
3690                 len = sysfs_emit(buf, "%s\n", ihost->netdev);
3691                 break;
3692         case ISCSI_HOST_PARAM_HWADDRESS:
3693                 len = sysfs_emit(buf, "%s\n", ihost->hwaddress);
3694                 break;
3695         case ISCSI_HOST_PARAM_INITIATOR_NAME:
3696                 len = sysfs_emit(buf, "%s\n", ihost->initiatorname);
3697                 break;
3698         default:
3699                 return -ENOSYS;
3700         }
3701
3702         return len;
3703 }
3704 EXPORT_SYMBOL_GPL(iscsi_host_get_param);
3705
3706 int iscsi_host_set_param(struct Scsi_Host *shost, enum iscsi_host_param param,
3707                          char *buf, int buflen)
3708 {
3709         struct iscsi_host *ihost = shost_priv(shost);
3710
3711         switch (param) {
3712         case ISCSI_HOST_PARAM_NETDEV_NAME:
3713                 return iscsi_switch_str_param(&ihost->netdev, buf);
3714         case ISCSI_HOST_PARAM_HWADDRESS:
3715                 return iscsi_switch_str_param(&ihost->hwaddress, buf);
3716         case ISCSI_HOST_PARAM_INITIATOR_NAME:
3717                 return iscsi_switch_str_param(&ihost->initiatorname, buf);
3718         default:
3719                 return -ENOSYS;
3720         }
3721
3722         return 0;
3723 }
3724 EXPORT_SYMBOL_GPL(iscsi_host_set_param);
3725
3726 MODULE_AUTHOR("Mike Christie");
3727 MODULE_DESCRIPTION("iSCSI library functions");
3728 MODULE_LICENSE("GPL");