drivers/scsi/libiscsi.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * iSCSI lib functions
   4  *
   5  * Copyright (C) 2006 Red Hat, Inc.  All rights reserved.
   6  * Copyright (C) 2004 - 2006 Mike Christie
   7  * Copyright (C) 2004 - 2005 Dmitry Yusupov
   8  * Copyright (C) 2004 - 2005 Alex Aizman
   9  * maintained by open-iscsi@googlegroups.com
  10  */
  11 #include <linux/types.h>
  12 #include <linux/kfifo.h>
  13 #include <linux/delay.h>
  14 #include <linux/log2.h>
  15 #include <linux/slab.h>
  16 #include <linux/sched/signal.h>
  17 #include <linux/module.h>
  18 #include <asm/unaligned.h>
  19 #include <net/tcp.h>
  20 #include <scsi/scsi_cmnd.h>
  21 #include <scsi/scsi_device.h>
  22 #include <scsi/scsi_eh.h>
  23 #include <scsi/scsi_tcq.h>
  24 #include <scsi/scsi_host.h>
  25 #include <scsi/scsi.h>
  26 #include <scsi/iscsi_proto.h>
  27 #include <scsi/scsi_transport.h>
  28 #include <scsi/scsi_transport_iscsi.h>
  29 #include <scsi/libiscsi.h>
  30 #include <trace/events/iscsi.h>
  31
  32 static int iscsi_dbg_lib_conn;
  33 module_param_named(debug_libiscsi_conn, iscsi_dbg_lib_conn, int,
  34                    S_IRUGO | S_IWUSR);
  35 MODULE_PARM_DESC(debug_libiscsi_conn,
  36                  "Turn on debugging for connections in libiscsi module. "
  37                  "Set to 1 to turn on, and zero to turn off. Default is off.");
  38
  39 static int iscsi_dbg_lib_session;
  40 module_param_named(debug_libiscsi_session, iscsi_dbg_lib_session, int,
  41                    S_IRUGO | S_IWUSR);
  42 MODULE_PARM_DESC(debug_libiscsi_session,
  43                  "Turn on debugging for sessions in libiscsi module. "
  44                  "Set to 1 to turn on, and zero to turn off. Default is off.");
  45
  46 static int iscsi_dbg_lib_eh;
  47 module_param_named(debug_libiscsi_eh, iscsi_dbg_lib_eh, int,
  48                    S_IRUGO | S_IWUSR);
  49 MODULE_PARM_DESC(debug_libiscsi_eh,
  50                  "Turn on debugging for error handling in libiscsi module. "
  51                  "Set to 1 to turn on, and zero to turn off. Default is off.");
  52
  53 #define ISCSI_DBG_CONN(_conn, dbg_fmt, arg...)                  \
  54         do {                                                    \
  55                 if (iscsi_dbg_lib_conn)                         \
  56                         iscsi_conn_printk(KERN_INFO, _conn,     \
  57                                              "%s " dbg_fmt,     \
  58                                              __func__, ##arg);  \
  59                 iscsi_dbg_trace(trace_iscsi_dbg_conn,           \
  60                                 &(_conn)->cls_conn->dev,        \
  61                                 "%s " dbg_fmt, __func__, ##arg);\
  62         } while (0);
  63
  64 #define ISCSI_DBG_SESSION(_session, dbg_fmt, arg...)                    \
  65         do {                                                            \
  66                 if (iscsi_dbg_lib_session)                              \
  67                         iscsi_session_printk(KERN_INFO, _session,       \
  68                                              "%s " dbg_fmt,             \
  69                                              __func__, ##arg);          \
  70                 iscsi_dbg_trace(trace_iscsi_dbg_session,                \
  71                                 &(_session)->cls_session->dev,          \
  72                                 "%s " dbg_fmt, __func__, ##arg);        \
  73         } while (0);
  74
  75 #define ISCSI_DBG_EH(_session, dbg_fmt, arg...)                         \
  76         do {                                                            \
  77                 if (iscsi_dbg_lib_eh)                                   \
  78                         iscsi_session_printk(KERN_INFO, _session,       \
  79                                              "%s " dbg_fmt,             \
  80                                              __func__, ##arg);          \
  81                 iscsi_dbg_trace(trace_iscsi_dbg_eh,                     \
  82                                 &(_session)->cls_session->dev,          \
  83                                 "%s " dbg_fmt, __func__, ##arg);        \
  84         } while (0);
  85
  86 inline void iscsi_conn_queue_xmit(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_xmit);
  95
  96 inline void iscsi_conn_queue_recv(struct iscsi_conn *conn)
  97 {
  98         struct Scsi_Host *shost = conn->session->host;
  99         struct iscsi_host *ihost = shost_priv(shost);
 100
 101         if (ihost->workq && !test_bit(ISCSI_CONN_FLAG_SUSPEND_RX, &conn->flags))
 102                 queue_work(ihost->workq, &conn->recvwork);
 103 }
 104 EXPORT_SYMBOL_GPL(iscsi_conn_queue_recv);
 105
 106 static void __iscsi_update_cmdsn(struct iscsi_session *session,
 107                                  uint32_t exp_cmdsn, uint32_t max_cmdsn)
 108 {
 109         /*
 110          * standard specifies this check for when to update expected and
 111          * max sequence numbers
 112          */
 113         if (iscsi_sna_lt(max_cmdsn, exp_cmdsn - 1))
 114                 return;
 115
 116         if (exp_cmdsn != session->exp_cmdsn &&
 117             !iscsi_sna_lt(exp_cmdsn, session->exp_cmdsn))
 118                 session->exp_cmdsn = exp_cmdsn;
 119
 120         if (max_cmdsn != session->max_cmdsn &&
 121             !iscsi_sna_lt(max_cmdsn, session->max_cmdsn))
 122                 session->max_cmdsn = max_cmdsn;
 123 }
 124
 125 void iscsi_update_cmdsn(struct iscsi_session *session, struct iscsi_nopin *hdr)
 126 {
 127         __iscsi_update_cmdsn(session, be32_to_cpu(hdr->exp_cmdsn),
 128                              be32_to_cpu(hdr->max_cmdsn));
 129 }
 130 EXPORT_SYMBOL_GPL(iscsi_update_cmdsn);
 131
 132 /**
 133  * iscsi_prep_data_out_pdu - initialize Data-Out
 134  * @task: scsi command task
 135  * @r2t: R2T info
 136  * @hdr: iscsi data in pdu
 137  *
 138  * Notes:
 139  *      Initialize Data-Out within this R2T sequence and finds
 140  *      proper data_offset within this SCSI command.
 141  *
 142  *      This function is called with connection lock taken.
 143  **/
 144 void iscsi_prep_data_out_pdu(struct iscsi_task *task, struct iscsi_r2t_info *r2t,
 145                            struct iscsi_data *hdr)
 146 {
 147         struct iscsi_conn *conn = task->conn;
 148         unsigned int left = r2t->data_length - r2t->sent;
 149
 150         task->hdr_len = sizeof(struct iscsi_data);
 151
 152         memset(hdr, 0, sizeof(struct iscsi_data));
 153         hdr->ttt = r2t->ttt;
 154         hdr->datasn = cpu_to_be32(r2t->datasn);
 155         r2t->datasn++;
 156         hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
 157         hdr->lun = task->lun;
 158         hdr->itt = task->hdr_itt;
 159         hdr->exp_statsn = r2t->exp_statsn;
 160         hdr->offset = cpu_to_be32(r2t->data_offset + r2t->sent);
 161         if (left > conn->max_xmit_dlength) {
 162                 hton24(hdr->dlength, conn->max_xmit_dlength);
 163                 r2t->data_count = conn->max_xmit_dlength;
 164                 hdr->flags = 0;
 165         } else {
 166                 hton24(hdr->dlength, left);
 167                 r2t->data_count = left;
 168                 hdr->flags = ISCSI_FLAG_CMD_FINAL;
 169         }
 170         conn->dataout_pdus_cnt++;
 171 }
 172 EXPORT_SYMBOL_GPL(iscsi_prep_data_out_pdu);
 173
 174 static int iscsi_add_hdr(struct iscsi_task *task, unsigned len)
 175 {
 176         unsigned exp_len = task->hdr_len + len;
 177
 178         if (exp_len > task->hdr_max) {
 179                 WARN_ON(1);
 180                 return -EINVAL;
 181         }
 182
 183         WARN_ON(len & (ISCSI_PAD_LEN - 1)); /* caller must pad the AHS */
 184         task->hdr_len = exp_len;
 185         return 0;
 186 }
 187
 188 /*
 189  * make an extended cdb AHS
 190  */
 191 static int iscsi_prep_ecdb_ahs(struct iscsi_task *task)
 192 {
 193         struct scsi_cmnd *cmd = task->sc;
 194         unsigned rlen, pad_len;
 195         unsigned short ahslength;
 196         struct iscsi_ecdb_ahdr *ecdb_ahdr;
 197         int rc;
 198
 199         ecdb_ahdr = iscsi_next_hdr(task);
 200         rlen = cmd->cmd_len - ISCSI_CDB_SIZE;
 201
 202         BUG_ON(rlen > sizeof(ecdb_ahdr->ecdb));
 203         ahslength = rlen + sizeof(ecdb_ahdr->reserved);
 204
 205         pad_len = iscsi_padding(rlen);
 206
 207         rc = iscsi_add_hdr(task, sizeof(ecdb_ahdr->ahslength) +
 208                            sizeof(ecdb_ahdr->ahstype) + ahslength + pad_len);
 209         if (rc)
 210                 return rc;
 211
 212         if (pad_len)
 213                 memset(&ecdb_ahdr->ecdb[rlen], 0, pad_len);
 214
 215         ecdb_ahdr->ahslength = cpu_to_be16(ahslength);
 216         ecdb_ahdr->ahstype = ISCSI_AHSTYPE_CDB;
 217         ecdb_ahdr->reserved = 0;
 218         memcpy(ecdb_ahdr->ecdb, cmd->cmnd + ISCSI_CDB_SIZE, rlen);
 219
 220         ISCSI_DBG_SESSION(task->conn->session,
 221                           "iscsi_prep_ecdb_ahs: varlen_cdb_len %d "
 222                           "rlen %d pad_len %d ahs_length %d iscsi_headers_size "
 223                           "%u\n", cmd->cmd_len, rlen, pad_len, ahslength,
 224                           task->hdr_len);
 225         return 0;
 226 }
 227
 228 /**
 229  * iscsi_check_tmf_restrictions - check if a task is affected by TMF
 230  * @task: iscsi task
 231  * @opcode: opcode to check for
 232  *
 233  * During TMF a task has to be checked if it's affected.
 234  * All unrelated I/O can be passed through, but I/O to the
 235  * affected LUN should be restricted.
 236  * If 'fast_abort' is set we won't be sending any I/O to the
 237  * affected LUN.
 238  * Otherwise the target is waiting for all TTTs to be completed,
 239  * so we have to send all outstanding Data-Out PDUs to the target.
 240  */
 241 static int iscsi_check_tmf_restrictions(struct iscsi_task *task, int opcode)
 242 {
 243         struct iscsi_session *session = task->conn->session;
 244         struct iscsi_tm *tmf = &session->tmhdr;
 245         u64 hdr_lun;
 246
 247         if (session->tmf_state == TMF_INITIAL)
 248                 return 0;
 249
 250         if ((tmf->opcode & ISCSI_OPCODE_MASK) != ISCSI_OP_SCSI_TMFUNC)
 251                 return 0;
 252
 253         switch (ISCSI_TM_FUNC_VALUE(tmf)) {
 254         case ISCSI_TM_FUNC_LOGICAL_UNIT_RESET:
 255                 /*
 256                  * Allow PDUs for unrelated LUNs
 257                  */
 258                 hdr_lun = scsilun_to_int(&tmf->lun);
 259                 if (hdr_lun != task->sc->device->lun)
 260                         return 0;
 261                 fallthrough;
 262         case ISCSI_TM_FUNC_TARGET_WARM_RESET:
 263                 /*
 264                  * Fail all SCSI cmd PDUs
 265                  */
 266                 if (opcode != ISCSI_OP_SCSI_DATA_OUT) {
 267                         iscsi_session_printk(KERN_INFO, session,
 268                                              "task [op %x itt 0x%x/0x%x] rejected.\n",
 269                                              opcode, task->itt, task->hdr_itt);
 270                         return -EACCES;
 271                 }
 272                 /*
 273                  * And also all data-out PDUs in response to R2T
 274                  * if fast_abort is set.
 275                  */
 276                 if (session->fast_abort) {
 277                         iscsi_session_printk(KERN_INFO, session,
 278                                              "task [op %x itt 0x%x/0x%x] fast abort.\n",
 279                                              opcode, task->itt, task->hdr_itt);
 280                         return -EACCES;
 281                 }
 282                 break;
 283         case ISCSI_TM_FUNC_ABORT_TASK:
 284                 /*
 285                  * the caller has already checked if the task
 286                  * they want to abort was in the pending queue so if
 287                  * we are here the cmd pdu has gone out already, and
 288                  * we will only hit this for data-outs
 289                  */
 290                 if (opcode == ISCSI_OP_SCSI_DATA_OUT &&
 291                     task->hdr_itt == tmf->rtt) {
 292                         ISCSI_DBG_SESSION(session,
 293                                           "Preventing task %x/%x from sending "
 294                                           "data-out due to abort task in "
 295                                           "progress\n", task->itt,
 296                                           task->hdr_itt);
 297                         return -EACCES;
 298                 }
 299                 break;
 300         }
 301
 302         return 0;
 303 }
 304
 305 /**
 306  * iscsi_prep_scsi_cmd_pdu - prep iscsi scsi cmd pdu
 307  * @task: iscsi task
 308  *
 309  * Prep basic iSCSI PDU fields for a scsi cmd pdu. The LLD should set
 310  * fields like dlength or final based on how much data it sends
 311  */
 312 static int iscsi_prep_scsi_cmd_pdu(struct iscsi_task *task)
 313 {
 314         struct iscsi_conn *conn = task->conn;
 315         struct iscsi_session *session = conn->session;
 316         struct scsi_cmnd *sc = task->sc;
 317         struct iscsi_scsi_req *hdr;
 318         unsigned hdrlength, cmd_len, transfer_length;
 319         itt_t itt;
 320         int rc;
 321
 322         rc = iscsi_check_tmf_restrictions(task, ISCSI_OP_SCSI_CMD);
 323         if (rc)
 324                 return rc;
 325
 326         if (conn->session->tt->alloc_pdu) {
 327                 rc = conn->session->tt->alloc_pdu(task, ISCSI_OP_SCSI_CMD);
 328                 if (rc)
 329                         return rc;
 330         }
 331         hdr = (struct iscsi_scsi_req *)task->hdr;
 332         itt = hdr->itt;
 333         memset(hdr, 0, sizeof(*hdr));
 334
 335         if (session->tt->parse_pdu_itt)
 336                 hdr->itt = task->hdr_itt = itt;
 337         else
 338                 hdr->itt = task->hdr_itt = build_itt(task->itt,
 339                                                      task->conn->session->age);
 340         task->hdr_len = 0;
 341         rc = iscsi_add_hdr(task, sizeof(*hdr));
 342         if (rc)
 343                 return rc;
 344         hdr->opcode = ISCSI_OP_SCSI_CMD;
 345         hdr->flags = ISCSI_ATTR_SIMPLE;
 346         int_to_scsilun(sc->device->lun, &hdr->lun);
 347         task->lun = hdr->lun;
 348         hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
 349         cmd_len = sc->cmd_len;
 350         if (cmd_len < ISCSI_CDB_SIZE)
 351                 memset(&hdr->cdb[cmd_len], 0, ISCSI_CDB_SIZE - cmd_len);
 352         else if (cmd_len > ISCSI_CDB_SIZE) {
 353                 rc = iscsi_prep_ecdb_ahs(task);
 354                 if (rc)
 355                         return rc;
 356                 cmd_len = ISCSI_CDB_SIZE;
 357         }
 358         memcpy(hdr->cdb, sc->cmnd, cmd_len);
 359
 360         task->imm_count = 0;
 361         if (scsi_get_prot_op(sc) != SCSI_PROT_NORMAL)
 362                 task->protected = true;
 363
 364         transfer_length = scsi_transfer_length(sc);
 365         hdr->data_length = cpu_to_be32(transfer_length);
 366         if (sc->sc_data_direction == DMA_TO_DEVICE) {
 367                 struct iscsi_r2t_info *r2t = &task->unsol_r2t;
 368
 369                 hdr->flags |= ISCSI_FLAG_CMD_WRITE;
 370                 /*
 371                  * Write counters:
 372                  *
 373                  *      imm_count       bytes to be sent right after
 374                  *                      SCSI PDU Header
 375                  *
 376                  *      unsol_count     bytes(as Data-Out) to be sent
 377                  *                      without R2T ack right after
 378                  *                      immediate data
 379                  *
 380                  *      r2t data_length bytes to be sent via R2T ack's
 381                  *
 382                  *      pad_count       bytes to be sent as zero-padding
 383                  */
 384                 memset(r2t, 0, sizeof(*r2t));
 385
 386                 if (session->imm_data_en) {
 387                         if (transfer_length >= session->first_burst)
 388                                 task->imm_count = min(session->first_burst,
 389                                                         conn->max_xmit_dlength);
 390                         else
 391                                 task->imm_count = min(transfer_length,
 392                                                       conn->max_xmit_dlength);
 393                         hton24(hdr->dlength, task->imm_count);
 394                 } else
 395                         zero_data(hdr->dlength);
 396
 397                 if (!session->initial_r2t_en) {
 398                         r2t->data_length = min(session->first_burst,
 399                                                transfer_length) -
 400                                                task->imm_count;
 401                         r2t->data_offset = task->imm_count;
 402                         r2t->ttt = cpu_to_be32(ISCSI_RESERVED_TAG);
 403                         r2t->exp_statsn = cpu_to_be32(conn->exp_statsn);
 404                 }
 405
 406                 if (!task->unsol_r2t.data_length)
 407                         /* No unsolicit Data-Out's */
 408                         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
 409         } else {
 410                 hdr->flags |= ISCSI_FLAG_CMD_FINAL;
 411                 zero_data(hdr->dlength);
 412
 413                 if (sc->sc_data_direction == DMA_FROM_DEVICE)
 414                         hdr->flags |= ISCSI_FLAG_CMD_READ;
 415         }
 416
 417         /* calculate size of additional header segments (AHSs) */
 418         hdrlength = task->hdr_len - sizeof(*hdr);
 419
 420         WARN_ON(hdrlength & (ISCSI_PAD_LEN-1));
 421         hdrlength /= ISCSI_PAD_LEN;
 422
 423         WARN_ON(hdrlength >= 256);
 424         hdr->hlength = hdrlength & 0xFF;
 425         hdr->cmdsn = task->cmdsn = cpu_to_be32(session->cmdsn);
 426
 427         if (session->tt->init_task && session->tt->init_task(task))
 428                 return -EIO;
 429
 430         task->state = ISCSI_TASK_RUNNING;
 431         session->cmdsn++;
 432
 433         conn->scsicmd_pdus_cnt++;
 434         ISCSI_DBG_SESSION(session, "iscsi prep [%s cid %d sc %p cdb 0x%x "
 435                           "itt 0x%x len %d cmdsn %d win %d]\n",
 436                           sc->sc_data_direction == DMA_TO_DEVICE ?
 437                           "write" : "read", conn->id, sc, sc->cmnd[0],
 438                           task->itt, transfer_length,
 439                           session->cmdsn,
 440                           session->max_cmdsn - session->exp_cmdsn + 1);
 441         return 0;
 442 }
 443
 444 /**
 445  * iscsi_free_task - free a task
 446  * @task: iscsi cmd task
 447  *
 448  * Must be called with session back_lock.
 449  * This function returns the scsi command to scsi-ml or cleans
 450  * up mgmt tasks then returns the task to the pool.
 451  */
 452 static void iscsi_free_task(struct iscsi_task *task)
 453 {
 454         struct iscsi_conn *conn = task->conn;
 455         struct iscsi_session *session = conn->session;
 456         struct scsi_cmnd *sc = task->sc;
 457         int oldstate = task->state;
 458
 459         ISCSI_DBG_SESSION(session, "freeing task itt 0x%x state %d sc %p\n",
 460                           task->itt, task->state, task->sc);
 461
 462         session->tt->cleanup_task(task);
 463         task->state = ISCSI_TASK_FREE;
 464         task->sc = NULL;
 465         /*
 466          * login task is preallocated so do not free
 467          */
 468         if (conn->login_task == task)
 469                 return;
 470
 471         kfifo_in(&session->cmdpool.queue, (void*)&task, sizeof(void*));
 472
 473         if (sc) {
 474                 /* SCSI eh reuses commands to verify us */
 475                 sc->SCp.ptr = NULL;
 476                 /*
 477                  * queue command may call this to free the task, so
 478                  * it will decide how to return sc to scsi-ml.
 479                  */
 480                 if (oldstate != ISCSI_TASK_REQUEUE_SCSIQ)
 481                         sc->scsi_done(sc);
 482         }
 483 }
 484
 485 void __iscsi_get_task(struct iscsi_task *task)
 486 {
 487         refcount_inc(&task->refcount);
 488 }
 489 EXPORT_SYMBOL_GPL(__iscsi_get_task);
 490
 491 void __iscsi_put_task(struct iscsi_task *task)
 492 {
 493         if (refcount_dec_and_test(&task->refcount))
 494                 iscsi_free_task(task);
 495 }
 496 EXPORT_SYMBOL_GPL(__iscsi_put_task);
 497
 498 void iscsi_put_task(struct iscsi_task *task)
 499 {
 500         struct iscsi_session *session = task->conn->session;
 501
 502         /* regular RX path uses back_lock */
 503         spin_lock_bh(&session->back_lock);
 504         __iscsi_put_task(task);
 505         spin_unlock_bh(&session->back_lock);
 506 }
 507 EXPORT_SYMBOL_GPL(iscsi_put_task);
 508
 509 /**
 510  * iscsi_complete_task - finish a task
 511  * @task: iscsi cmd task
 512  * @state: state to complete task with
 513  *
 514  * Must be called with session back_lock.
 515  */
 516 static void iscsi_complete_task(struct iscsi_task *task, int state)
 517 {
 518         struct iscsi_conn *conn = task->conn;
 519
 520         ISCSI_DBG_SESSION(conn->session,
 521                           "complete task itt 0x%x state %d sc %p\n",
 522                           task->itt, task->state, task->sc);
 523         if (task->state == ISCSI_TASK_COMPLETED ||
 524             task->state == ISCSI_TASK_ABRT_TMF ||
 525             task->state == ISCSI_TASK_ABRT_SESS_RECOV ||
 526             task->state == ISCSI_TASK_REQUEUE_SCSIQ)
 527                 return;
 528         WARN_ON_ONCE(task->state == ISCSI_TASK_FREE);
 529         task->state = state;
 530
 531         if (READ_ONCE(conn->ping_task) == task)
 532                 WRITE_ONCE(conn->ping_task, NULL);
 533
 534         /* release get from queueing */
 535         __iscsi_put_task(task);
 536 }
 537
 538 /**
 539  * iscsi_complete_scsi_task - finish scsi task normally
 540  * @task: iscsi task for scsi cmd
 541  * @exp_cmdsn: expected cmd sn in cpu format
 542  * @max_cmdsn: max cmd sn in cpu format
 543  *
 544  * This is used when drivers do not need or cannot perform
 545  * lower level pdu processing.
 546  *
 547  * Called with session back_lock
 548  */
 549 void iscsi_complete_scsi_task(struct iscsi_task *task,
 550                               uint32_t exp_cmdsn, uint32_t max_cmdsn)
 551 {
 552         struct iscsi_conn *conn = task->conn;
 553
 554         ISCSI_DBG_SESSION(conn->session, "[itt 0x%x]\n", task->itt);
 555
 556         conn->last_recv = jiffies;
 557         __iscsi_update_cmdsn(conn->session, exp_cmdsn, max_cmdsn);
 558         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 559 }
 560 EXPORT_SYMBOL_GPL(iscsi_complete_scsi_task);
 561
 562 /*
 563  * Must be called with back and frwd lock
 564  */
 565 static bool cleanup_queued_task(struct iscsi_task *task)
 566 {
 567         struct iscsi_conn *conn = task->conn;
 568         bool early_complete = false;
 569
 570         /* Bad target might have completed task while it was still running */
 571         if (task->state == ISCSI_TASK_COMPLETED)
 572                 early_complete = true;
 573
 574         if (!list_empty(&task->running)) {
 575                 list_del_init(&task->running);
 576                 /*
 577                  * If it's on a list but still running, this could be from
 578                  * a bad target sending a rsp early, cleanup from a TMF, or
 579                  * session recovery.
 580                  */
 581                 if (task->state == ISCSI_TASK_RUNNING ||
 582                     task->state == ISCSI_TASK_COMPLETED)
 583                         __iscsi_put_task(task);
 584         }
 585
 586         if (conn->session->running_aborted_task == task) {
 587                 conn->session->running_aborted_task = NULL;
 588                 __iscsi_put_task(task);
 589         }
 590
 591         if (conn->task == task) {
 592                 conn->task = NULL;
 593                 __iscsi_put_task(task);
 594         }
 595
 596         return early_complete;
 597 }
 598
 599 /*
 600  * session frwd lock must be held and if not called for a task that is still
 601  * pending or from the xmit thread, then xmit thread must be suspended
 602  */
 603 static void fail_scsi_task(struct iscsi_task *task, int err)
 604 {
 605         struct iscsi_conn *conn = task->conn;
 606         struct scsi_cmnd *sc;
 607         int state;
 608
 609         spin_lock_bh(&conn->session->back_lock);
 610         if (cleanup_queued_task(task)) {
 611                 spin_unlock_bh(&conn->session->back_lock);
 612                 return;
 613         }
 614
 615         if (task->state == ISCSI_TASK_PENDING) {
 616                 /*
 617                  * cmd never made it to the xmit thread, so we should not count
 618                  * the cmd in the sequencing
 619                  */
 620                 conn->session->queued_cmdsn--;
 621                 /* it was never sent so just complete like normal */
 622                 state = ISCSI_TASK_COMPLETED;
 623         } else if (err == DID_TRANSPORT_DISRUPTED)
 624                 state = ISCSI_TASK_ABRT_SESS_RECOV;
 625         else
 626                 state = ISCSI_TASK_ABRT_TMF;
 627
 628         sc = task->sc;
 629         sc->result = err << 16;
 630         scsi_set_resid(sc, scsi_bufflen(sc));
 631         iscsi_complete_task(task, state);
 632         spin_unlock_bh(&conn->session->back_lock);
 633 }
 634
 635 static int iscsi_prep_mgmt_task(struct iscsi_conn *conn,
 636                                 struct iscsi_task *task)
 637 {
 638         struct iscsi_session *session = conn->session;
 639         struct iscsi_hdr *hdr = task->hdr;
 640         struct iscsi_nopout *nop = (struct iscsi_nopout *)hdr;
 641         uint8_t opcode = hdr->opcode & ISCSI_OPCODE_MASK;
 642
 643         if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
 644                 return -ENOTCONN;
 645
 646         if (opcode != ISCSI_OP_LOGIN && opcode != ISCSI_OP_TEXT)
 647                 nop->exp_statsn = cpu_to_be32(conn->exp_statsn);
 648         /*
 649          * pre-format CmdSN for outgoing PDU.
 650          */
 651         nop->cmdsn = cpu_to_be32(session->cmdsn);
 652         if (hdr->itt != RESERVED_ITT) {
 653                 /*
 654                  * TODO: We always use immediate for normal session pdus.
 655                  * If we start to send tmfs or nops as non-immediate then
 656                  * we should start checking the cmdsn numbers for mgmt tasks.
 657                  *
 658                  * During discovery sessions iscsid sends TEXT as non immediate,
 659                  * but we always only send one PDU at a time.
 660                  */
 661                 if (conn->c_stage == ISCSI_CONN_STARTED &&
 662                     !(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
 663                         session->queued_cmdsn++;
 664                         session->cmdsn++;
 665                 }
 666         }
 667
 668         if (session->tt->init_task && session->tt->init_task(task))
 669                 return -EIO;
 670
 671         if ((hdr->opcode & ISCSI_OPCODE_MASK) == ISCSI_OP_LOGOUT)
 672                 session->state = ISCSI_STATE_LOGGING_OUT;
 673
 674         task->state = ISCSI_TASK_RUNNING;
 675         ISCSI_DBG_SESSION(session, "mgmtpdu [op 0x%x hdr->itt 0x%x "
 676                           "datalen %d]\n", hdr->opcode & ISCSI_OPCODE_MASK,
 677                           hdr->itt, task->data_count);
 678         return 0;
 679 }
 680
 681 static struct iscsi_task *
 682 __iscsi_conn_send_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 683                       char *data, uint32_t data_size)
 684 {
 685         struct iscsi_session *session = conn->session;
 686         struct iscsi_host *ihost = shost_priv(session->host);
 687         uint8_t opcode = hdr->opcode & ISCSI_OPCODE_MASK;
 688         struct iscsi_task *task;
 689         itt_t itt;
 690
 691         if (session->state == ISCSI_STATE_TERMINATE ||
 692             !test_bit(ISCSI_CONN_FLAG_BOUND, &conn->flags))
 693                 return NULL;
 694
 695         if (opcode == ISCSI_OP_LOGIN || opcode == ISCSI_OP_TEXT) {
 696                 /*
 697                  * Login and Text are sent serially, in
 698                  * request-followed-by-response sequence.
 699                  * Same task can be used. Same ITT must be used.
 700                  * Note that login_task is preallocated at conn_create().
 701                  */
 702                 if (conn->login_task->state != ISCSI_TASK_FREE) {
 703                         iscsi_conn_printk(KERN_ERR, conn, "Login/Text in "
 704                                           "progress. Cannot start new task.\n");
 705                         return NULL;
 706                 }
 707
 708                 if (data_size > ISCSI_DEF_MAX_RECV_SEG_LEN) {
 709                         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);
 710                         return NULL;
 711                 }
 712
 713                 task = conn->login_task;
 714         } else {
 715                 if (session->state != ISCSI_STATE_LOGGED_IN)
 716                         return NULL;
 717
 718                 if (data_size != 0) {
 719                         iscsi_conn_printk(KERN_ERR, conn, "Can not send data buffer of len %u for op 0x%x\n", data_size, opcode);
 720                         return NULL;
 721                 }
 722
 723                 BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
 724                 BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);
 725
 726                 if (!kfifo_out(&session->cmdpool.queue,
 727                                  (void*)&task, sizeof(void*)))
 728                         return NULL;
 729         }
 730         /*
 731          * released in complete pdu for task we expect a response for, and
 732          * released by the lld when it has transmitted the task for
 733          * pdus we do not expect a response for.
 734          */
 735         refcount_set(&task->refcount, 1);
 736         task->conn = conn;
 737         task->sc = NULL;
 738         INIT_LIST_HEAD(&task->running);
 739         task->state = ISCSI_TASK_PENDING;
 740
 741         if (data_size) {
 742                 memcpy(task->data, data, data_size);
 743                 task->data_count = data_size;
 744         } else
 745                 task->data_count = 0;
 746
 747         if (conn->session->tt->alloc_pdu) {
 748                 if (conn->session->tt->alloc_pdu(task, hdr->opcode)) {
 749                         iscsi_conn_printk(KERN_ERR, conn, "Could not allocate "
 750                                          "pdu for mgmt task.\n");
 751                         goto free_task;
 752                 }
 753         }
 754
 755         itt = task->hdr->itt;
 756         task->hdr_len = sizeof(struct iscsi_hdr);
 757         memcpy(task->hdr, hdr, sizeof(struct iscsi_hdr));
 758
 759         if (hdr->itt != RESERVED_ITT) {
 760                 if (session->tt->parse_pdu_itt)
 761                         task->hdr->itt = itt;
 762                 else
 763                         task->hdr->itt = build_itt(task->itt,
 764                                                    task->conn->session->age);
 765         }
 766
 767         if (unlikely(READ_ONCE(conn->ping_task) == INVALID_SCSI_TASK))
 768                 WRITE_ONCE(conn->ping_task, task);
 769
 770         if (!ihost->workq) {
 771                 if (iscsi_prep_mgmt_task(conn, task))
 772                         goto free_task;
 773
 774                 if (session->tt->xmit_task(task))
 775                         goto free_task;
 776         } else {
 777                 list_add_tail(&task->running, &conn->mgmtqueue);
 778                 iscsi_conn_queue_xmit(conn);
 779         }
 780
 781         return task;
 782
 783 free_task:
 784         /* regular RX path uses back_lock */
 785         spin_lock(&session->back_lock);
 786         __iscsi_put_task(task);
 787         spin_unlock(&session->back_lock);
 788         return NULL;
 789 }
 790
 791 int iscsi_conn_send_pdu(struct iscsi_cls_conn *cls_conn, struct iscsi_hdr *hdr,
 792                         char *data, uint32_t data_size)
 793 {
 794         struct iscsi_conn *conn = cls_conn->dd_data;
 795         struct iscsi_session *session = conn->session;
 796         int err = 0;
 797
 798         spin_lock_bh(&session->frwd_lock);
 799         if (!__iscsi_conn_send_pdu(conn, hdr, data, data_size))
 800                 err = -EPERM;
 801         spin_unlock_bh(&session->frwd_lock);
 802         return err;
 803 }
 804 EXPORT_SYMBOL_GPL(iscsi_conn_send_pdu);
 805
 806 /**
 807  * iscsi_scsi_cmd_rsp - SCSI Command Response processing
 808  * @conn: iscsi connection
 809  * @hdr: iscsi header
 810  * @task: scsi command task
 811  * @data: cmd data buffer
 812  * @datalen: len of buffer
 813  *
 814  * iscsi_cmd_rsp sets up the scsi_cmnd fields based on the PDU and
 815  * then completes the command and task. called under back_lock
 816  **/
 817 static void iscsi_scsi_cmd_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 818                                struct iscsi_task *task, char *data,
 819                                int datalen)
 820 {
 821         struct iscsi_scsi_rsp *rhdr = (struct iscsi_scsi_rsp *)hdr;
 822         struct iscsi_session *session = conn->session;
 823         struct scsi_cmnd *sc = task->sc;
 824
 825         iscsi_update_cmdsn(session, (struct iscsi_nopin*)rhdr);
 826         conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 827
 828         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 829
 830         if (task->protected) {
 831                 sector_t sector;
 832                 u8 ascq;
 833
 834                 /**
 835                  * Transports that didn't implement check_protection
 836                  * callback but still published T10-PI support to scsi-mid
 837                  * deserve this BUG_ON.
 838                  **/
 839                 BUG_ON(!session->tt->check_protection);
 840
 841                 ascq = session->tt->check_protection(task, &sector);
 842                 if (ascq) {
 843                         scsi_build_sense(sc, 1, ILLEGAL_REQUEST, 0x10, ascq);
 844                         scsi_set_sense_information(sc->sense_buffer,
 845                                                    SCSI_SENSE_BUFFERSIZE,
 846                                                    sector);
 847                         goto out;
 848                 }
 849         }
 850
 851         if (rhdr->response != ISCSI_STATUS_CMD_COMPLETED) {
 852                 sc->result = DID_ERROR << 16;
 853                 goto out;
 854         }
 855
 856         if (rhdr->cmd_status == SAM_STAT_CHECK_CONDITION) {
 857                 uint16_t senselen;
 858
 859                 if (datalen < 2) {
 860 invalid_datalen:
 861                         iscsi_conn_printk(KERN_ERR,  conn,
 862                                          "Got CHECK_CONDITION but invalid data "
 863                                          "buffer size of %d\n", datalen);
 864                         sc->result = DID_BAD_TARGET << 16;
 865                         goto out;
 866                 }
 867
 868                 senselen = get_unaligned_be16(data);
 869                 if (datalen < senselen)
 870                         goto invalid_datalen;
 871
 872                 memcpy(sc->sense_buffer, data + 2,
 873                        min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
 874                 ISCSI_DBG_SESSION(session, "copied %d bytes of sense\n",
 875                                   min_t(uint16_t, senselen,
 876                                   SCSI_SENSE_BUFFERSIZE));
 877         }
 878
 879         if (rhdr->flags & (ISCSI_FLAG_CMD_BIDI_UNDERFLOW |
 880                            ISCSI_FLAG_CMD_BIDI_OVERFLOW)) {
 881                 sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 882         }
 883
 884         if (rhdr->flags & (ISCSI_FLAG_CMD_UNDERFLOW |
 885                            ISCSI_FLAG_CMD_OVERFLOW)) {
 886                 int res_count = be32_to_cpu(rhdr->residual_count);
 887
 888                 if (res_count > 0 &&
 889                     (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
 890                      res_count <= scsi_bufflen(sc)))
 891                         /* write side for bidi or uni-io set_resid */
 892                         scsi_set_resid(sc, res_count);
 893                 else
 894                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 895         }
 896 out:
 897         ISCSI_DBG_SESSION(session, "cmd rsp done [sc %p res %d itt 0x%x]\n",
 898                           sc, sc->result, task->itt);
 899         conn->scsirsp_pdus_cnt++;
 900         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 901 }
 902
 903 /**
 904  * iscsi_data_in_rsp - SCSI Data-In Response processing
 905  * @conn: iscsi connection
 906  * @hdr:  iscsi pdu
 907  * @task: scsi command task
 908  *
 909  * iscsi_data_in_rsp sets up the scsi_cmnd fields based on the data received
 910  * then completes the command and task. called under back_lock
 911  **/
 912 static void
 913 iscsi_data_in_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 914                   struct iscsi_task *task)
 915 {
 916         struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)hdr;
 917         struct scsi_cmnd *sc = task->sc;
 918
 919         if (!(rhdr->flags & ISCSI_FLAG_DATA_STATUS))
 920                 return;
 921
 922         iscsi_update_cmdsn(conn->session, (struct iscsi_nopin *)hdr);
 923         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 924         conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 925         if (rhdr->flags & (ISCSI_FLAG_DATA_UNDERFLOW |
 926                            ISCSI_FLAG_DATA_OVERFLOW)) {
 927                 int res_count = be32_to_cpu(rhdr->residual_count);
 928
 929                 if (res_count > 0 &&
 930                     (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
 931                      res_count <= sc->sdb.length))
 932                         scsi_set_resid(sc, res_count);
 933                 else
 934                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 935         }
 936
 937         ISCSI_DBG_SESSION(conn->session, "data in with status done "
 938                           "[sc %p res %d itt 0x%x]\n",
 939                           sc, sc->result, task->itt);
 940         conn->scsirsp_pdus_cnt++;
 941         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 942 }
 943
 944 static void iscsi_tmf_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
 945 {
 946         struct iscsi_tm_rsp *tmf = (struct iscsi_tm_rsp *)hdr;
 947         struct iscsi_session *session = conn->session;
 948
 949         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 950         conn->tmfrsp_pdus_cnt++;
 951
 952         if (session->tmf_state != TMF_QUEUED)
 953                 return;
 954
 955         if (tmf->response == ISCSI_TMF_RSP_COMPLETE)
 956                 session->tmf_state = TMF_SUCCESS;
 957         else if (tmf->response == ISCSI_TMF_RSP_NO_TASK)
 958                 session->tmf_state = TMF_NOT_FOUND;
 959         else
 960                 session->tmf_state = TMF_FAILED;
 961         wake_up(&session->ehwait);
 962 }
 963
 964 static int iscsi_send_nopout(struct iscsi_conn *conn, struct iscsi_nopin *rhdr)
 965 {
 966         struct iscsi_nopout hdr;
 967         struct iscsi_task *task;
 968
 969         if (!rhdr) {
 970                 if (READ_ONCE(conn->ping_task))
 971                         return -EINVAL;
 972                 WRITE_ONCE(conn->ping_task, INVALID_SCSI_TASK);
 973         }
 974
 975         memset(&hdr, 0, sizeof(struct iscsi_nopout));
 976         hdr.opcode = ISCSI_OP_NOOP_OUT | ISCSI_OP_IMMEDIATE;
 977         hdr.flags = ISCSI_FLAG_CMD_FINAL;
 978
 979         if (rhdr) {
 980                 hdr.lun = rhdr->lun;
 981                 hdr.ttt = rhdr->ttt;
 982                 hdr.itt = RESERVED_ITT;
 983         } else
 984                 hdr.ttt = RESERVED_ITT;
 985
 986         task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)&hdr, NULL, 0);
 987         if (!task) {
 988                 if (!rhdr)
 989                         WRITE_ONCE(conn->ping_task, NULL);
 990                 iscsi_conn_printk(KERN_ERR, conn, "Could not send nopout\n");
 991                 return -EIO;
 992         } else if (!rhdr) {
 993                 /* only track our nops */
 994                 conn->last_ping = jiffies;
 995         }
 996
 997         return 0;
 998 }
 999
1000 /**
1001  * iscsi_nop_out_rsp - SCSI NOP Response processing
1002  * @task: scsi command task
1003  * @nop: the nop structure
1004  * @data: where to put the data
1005  * @datalen: length of data
1006  *
1007  * iscsi_nop_out_rsp handles nop response from use or
1008  * from user space. called under back_lock
1009  **/
1010 static int iscsi_nop_out_rsp(struct iscsi_task *task,
1011                              struct iscsi_nopin *nop, char *data, int datalen)
1012 {
1013         struct iscsi_conn *conn = task->conn;
1014         int rc = 0;
1015
1016         if (READ_ONCE(conn->ping_task) != task) {
1017                 /*
1018                  * If this is not in response to one of our
1019                  * nops then it must be from userspace.
1020                  */
1021                 if (iscsi_recv_pdu(conn->cls_conn, (struct iscsi_hdr *)nop,
1022                                    data, datalen))
1023                         rc = ISCSI_ERR_CONN_FAILED;
1024         } else
1025                 mod_timer(&conn->transport_timer, jiffies + conn->recv_timeout);
1026         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1027         return rc;
1028 }
1029
1030 static int iscsi_handle_reject(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1031                                char *data, int datalen)
1032 {
1033         struct iscsi_reject *reject = (struct iscsi_reject *)hdr;
1034         struct iscsi_hdr rejected_pdu;
1035         int opcode, rc = 0;
1036
1037         conn->exp_statsn = be32_to_cpu(reject->statsn) + 1;
1038
1039         if (ntoh24(reject->dlength) > datalen ||
1040             ntoh24(reject->dlength) < sizeof(struct iscsi_hdr)) {
1041                 iscsi_conn_printk(KERN_ERR, conn, "Cannot handle rejected "
1042                                   "pdu. Invalid data length (pdu dlength "
1043                                   "%u, datalen %d\n", ntoh24(reject->dlength),
1044                                   datalen);
1045                 return ISCSI_ERR_PROTO;
1046         }
1047         memcpy(&rejected_pdu, data, sizeof(struct iscsi_hdr));
1048         opcode = rejected_pdu.opcode & ISCSI_OPCODE_MASK;
1049
1050         switch (reject->reason) {
1051         case ISCSI_REASON_DATA_DIGEST_ERROR:
1052                 iscsi_conn_printk(KERN_ERR, conn,
1053                                   "pdu (op 0x%x itt 0x%x) rejected "
1054                                   "due to DataDigest error.\n",
1055                                   opcode, rejected_pdu.itt);
1056                 break;
1057         case ISCSI_REASON_IMM_CMD_REJECT:
1058                 iscsi_conn_printk(KERN_ERR, conn,
1059                                   "pdu (op 0x%x itt 0x%x) rejected. Too many "
1060                                   "immediate commands.\n",
1061                                   opcode, rejected_pdu.itt);
1062                 /*
1063                  * We only send one TMF at a time so if the target could not
1064                  * handle it, then it should get fixed (RFC mandates that
1065                  * a target can handle one immediate TMF per conn).
1066                  *
1067                  * For nops-outs, we could have sent more than one if
1068                  * the target is sending us lots of nop-ins
1069                  */
1070                 if (opcode != ISCSI_OP_NOOP_OUT)
1071                         return 0;
1072
1073                 if (rejected_pdu.itt == cpu_to_be32(ISCSI_RESERVED_TAG)) {
1074                         /*
1075                          * nop-out in response to target's nop-out rejected.
1076                          * Just resend.
1077                          */
1078                         /* In RX path we are under back lock */
1079                         spin_unlock(&conn->session->back_lock);
1080                         spin_lock(&conn->session->frwd_lock);
1081                         iscsi_send_nopout(conn,
1082                                           (struct iscsi_nopin*)&rejected_pdu);
1083                         spin_unlock(&conn->session->frwd_lock);
1084                         spin_lock(&conn->session->back_lock);
1085                 } else {
1086                         struct iscsi_task *task;
1087                         /*
1088                          * Our nop as ping got dropped. We know the target
1089                          * and transport are ok so just clean up
1090                          */
1091                         task = iscsi_itt_to_task(conn, rejected_pdu.itt);
1092                         if (!task) {
1093                                 iscsi_conn_printk(KERN_ERR, conn,
1094                                                  "Invalid pdu reject. Could "
1095                                                  "not lookup rejected task.\n");
1096                                 rc = ISCSI_ERR_BAD_ITT;
1097                         } else
1098                                 rc = iscsi_nop_out_rsp(task,
1099                                         (struct iscsi_nopin*)&rejected_pdu,
1100                                         NULL, 0);
1101                 }
1102                 break;
1103         default:
1104                 iscsi_conn_printk(KERN_ERR, conn,
1105                                   "pdu (op 0x%x itt 0x%x) rejected. Reason "
1106                                   "code 0x%x\n", rejected_pdu.opcode,
1107                                   rejected_pdu.itt, reject->reason);
1108                 break;
1109         }
1110         return rc;
1111 }
1112
1113 /**
1114  * iscsi_itt_to_task - look up task by itt
1115  * @conn: iscsi connection
1116  * @itt: itt
1117  *
1118  * This should be used for mgmt tasks like login and nops, or if
1119  * the LDD's itt space does not include the session age.
1120  *
1121  * The session back_lock must be held.
1122  */
1123 struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *conn, itt_t itt)
1124 {
1125         struct iscsi_session *session = conn->session;
1126         int i;
1127
1128         if (itt == RESERVED_ITT)
1129                 return NULL;
1130
1131         if (session->tt->parse_pdu_itt)
1132                 session->tt->parse_pdu_itt(conn, itt, &i, NULL);
1133         else
1134                 i = get_itt(itt);
1135         if (i >= session->cmds_max)
1136                 return NULL;
1137
1138         return session->cmds[i];
1139 }
1140 EXPORT_SYMBOL_GPL(iscsi_itt_to_task);
1141
1142 /**
1143  * __iscsi_complete_pdu - complete pdu
1144  * @conn: iscsi conn
1145  * @hdr: iscsi header
1146  * @data: data buffer
1147  * @datalen: len of data buffer
1148  *
1149  * Completes pdu processing by freeing any resources allocated at
1150  * queuecommand or send generic. session back_lock must be held and verify
1151  * itt must have been called.
1152  */
1153 int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1154                          char *data, int datalen)
1155 {
1156         struct iscsi_session *session = conn->session;
1157         int opcode = hdr->opcode & ISCSI_OPCODE_MASK, rc = 0;
1158         struct iscsi_task *task;
1159         uint32_t itt;
1160
1161         conn->last_recv = jiffies;
1162         rc = iscsi_verify_itt(conn, hdr->itt);
1163         if (rc)
1164                 return rc;
1165
1166         if (hdr->itt != RESERVED_ITT)
1167                 itt = get_itt(hdr->itt);
1168         else
1169                 itt = ~0U;
1170
1171         ISCSI_DBG_SESSION(session, "[op 0x%x cid %d itt 0x%x len %d]\n",
1172                           opcode, conn->id, itt, datalen);
1173
1174         if (itt == ~0U) {
1175                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1176
1177                 switch(opcode) {
1178                 case ISCSI_OP_NOOP_IN:
1179                         if (datalen) {
1180                                 rc = ISCSI_ERR_PROTO;
1181                                 break;
1182                         }
1183
1184                         if (hdr->ttt == cpu_to_be32(ISCSI_RESERVED_TAG))
1185                                 break;
1186
1187                         /* In RX path we are under back lock */
1188                         spin_unlock(&session->back_lock);
1189                         spin_lock(&session->frwd_lock);
1190                         iscsi_send_nopout(conn, (struct iscsi_nopin*)hdr);
1191                         spin_unlock(&session->frwd_lock);
1192                         spin_lock(&session->back_lock);
1193                         break;
1194                 case ISCSI_OP_REJECT:
1195                         rc = iscsi_handle_reject(conn, hdr, data, datalen);
1196                         break;
1197                 case ISCSI_OP_ASYNC_EVENT:
1198                         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1199                         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
1200                                 rc = ISCSI_ERR_CONN_FAILED;
1201                         break;
1202                 default:
1203                         rc = ISCSI_ERR_BAD_OPCODE;
1204                         break;
1205                 }
1206                 goto out;
1207         }
1208
1209         switch(opcode) {
1210         case ISCSI_OP_SCSI_CMD_RSP:
1211         case ISCSI_OP_SCSI_DATA_IN:
1212                 task = iscsi_itt_to_ctask(conn, hdr->itt);
1213                 if (!task)
1214                         return ISCSI_ERR_BAD_ITT;
1215                 task->last_xfer = jiffies;
1216                 break;
1217         case ISCSI_OP_R2T:
1218                 /*
1219                  * LLD handles R2Ts if they need to.
1220                  */
1221                 return 0;
1222         case ISCSI_OP_LOGOUT_RSP:
1223         case ISCSI_OP_LOGIN_RSP:
1224         case ISCSI_OP_TEXT_RSP:
1225         case ISCSI_OP_SCSI_TMFUNC_RSP:
1226         case ISCSI_OP_NOOP_IN:
1227                 task = iscsi_itt_to_task(conn, hdr->itt);
1228                 if (!task)
1229                         return ISCSI_ERR_BAD_ITT;
1230                 break;
1231         default:
1232                 return ISCSI_ERR_BAD_OPCODE;
1233         }
1234
1235         switch(opcode) {
1236         case ISCSI_OP_SCSI_CMD_RSP:
1237                 iscsi_scsi_cmd_rsp(conn, hdr, task, data, datalen);
1238                 break;
1239         case ISCSI_OP_SCSI_DATA_IN:
1240                 iscsi_data_in_rsp(conn, hdr, task);
1241                 break;
1242         case ISCSI_OP_LOGOUT_RSP:
1243                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1244                 if (datalen) {
1245                         rc = ISCSI_ERR_PROTO;
1246                         break;
1247                 }
1248                 conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1249                 goto recv_pdu;
1250         case ISCSI_OP_LOGIN_RSP:
1251         case ISCSI_OP_TEXT_RSP:
1252                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1253                 /*
1254                  * login related PDU's exp_statsn is handled in
1255                  * userspace
1256                  */
1257                 goto recv_pdu;
1258         case ISCSI_OP_SCSI_TMFUNC_RSP:
1259                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1260                 if (datalen) {
1261                         rc = ISCSI_ERR_PROTO;
1262                         break;
1263                 }
1264
1265                 iscsi_tmf_rsp(conn, hdr);
1266                 iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1267                 break;
1268         case ISCSI_OP_NOOP_IN:
1269                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1270                 if (hdr->ttt != cpu_to_be32(ISCSI_RESERVED_TAG) || datalen) {
1271                         rc = ISCSI_ERR_PROTO;
1272                         break;
1273                 }
1274                 conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1275
1276                 rc = iscsi_nop_out_rsp(task, (struct iscsi_nopin*)hdr,
1277                                        data, datalen);
1278                 break;
1279         default:
1280                 rc = ISCSI_ERR_BAD_OPCODE;
1281                 break;
1282         }
1283
1284 out:
1285         return rc;
1286 recv_pdu:
1287         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
1288                 rc = ISCSI_ERR_CONN_FAILED;
1289         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1290         return rc;
1291 }
1292 EXPORT_SYMBOL_GPL(__iscsi_complete_pdu);
1293
1294 int iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1295                        char *data, int datalen)
1296 {
1297         int rc;
1298
1299         spin_lock(&conn->session->back_lock);
1300         rc = __iscsi_complete_pdu(conn, hdr, data, datalen);
1301         spin_unlock(&conn->session->back_lock);
1302         return rc;
1303 }
1304 EXPORT_SYMBOL_GPL(iscsi_complete_pdu);
1305
1306 int iscsi_verify_itt(struct iscsi_conn *conn, itt_t itt)
1307 {
1308         struct iscsi_session *session = conn->session;
1309         int age = 0, i = 0;
1310
1311         if (itt == RESERVED_ITT)
1312                 return 0;
1313
1314         if (session->tt->parse_pdu_itt)
1315                 session->tt->parse_pdu_itt(conn, itt, &i, &age);
1316         else {
1317                 i = get_itt(itt);
1318                 age = ((__force u32)itt >> ISCSI_AGE_SHIFT) & ISCSI_AGE_MASK;
1319         }
1320
1321         if (age != session->age) {
1322                 iscsi_conn_printk(KERN_ERR, conn,
1323                                   "received itt %x expected session age (%x)\n",
1324                                   (__force u32)itt, session->age);
1325                 return ISCSI_ERR_BAD_ITT;
1326         }
1327
1328         if (i >= session->cmds_max) {
1329                 iscsi_conn_printk(KERN_ERR, conn,
1330                                   "received invalid itt index %u (max cmds "
1331                                    "%u.\n", i, session->cmds_max);
1332                 return ISCSI_ERR_BAD_ITT;
1333         }
1334         return 0;
1335 }
1336 EXPORT_SYMBOL_GPL(iscsi_verify_itt);
1337
1338 /**
1339  * iscsi_itt_to_ctask - look up ctask by itt
1340  * @conn: iscsi connection
1341  * @itt: itt
1342  *
1343  * This should be used for cmd tasks.
1344  *
1345  * The session back_lock must be held.
1346  */
1347 struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *conn, itt_t itt)
1348 {
1349         struct iscsi_task *task;
1350
1351         if (iscsi_verify_itt(conn, itt))
1352                 return NULL;
1353
1354         task = iscsi_itt_to_task(conn, itt);
1355         if (!task || !task->sc)
1356                 return NULL;
1357
1358         if (task->sc->SCp.phase != conn->session->age) {
1359                 iscsi_session_printk(KERN_ERR, conn->session,
1360                                   "task's session age %d, expected %d\n",
1361                                   task->sc->SCp.phase, conn->session->age);
1362                 return NULL;
1363         }
1364
1365         return task;
1366 }
1367 EXPORT_SYMBOL_GPL(iscsi_itt_to_ctask);
1368
1369 void iscsi_session_failure(struct iscsi_session *session,
1370                            enum iscsi_err err)
1371 {
1372         struct iscsi_conn *conn;
1373
1374         spin_lock_bh(&session->frwd_lock);
1375         conn = session->leadconn;
1376         if (session->state == ISCSI_STATE_TERMINATE || !conn) {
1377                 spin_unlock_bh(&session->frwd_lock);
1378                 return;
1379         }
1380
1381         iscsi_get_conn(conn->cls_conn);
1382         spin_unlock_bh(&session->frwd_lock);
1383         /*
1384          * if the host is being removed bypass the connection
1385          * recovery initialization because we are going to kill
1386          * the session.
1387          */
1388         if (err == ISCSI_ERR_INVALID_HOST)
1389                 iscsi_conn_error_event(conn->cls_conn, err);
1390         else
1391                 iscsi_conn_failure(conn, err);
1392         iscsi_put_conn(conn->cls_conn);
1393 }
1394 EXPORT_SYMBOL_GPL(iscsi_session_failure);
1395
1396 static bool iscsi_set_conn_failed(struct iscsi_conn *conn)
1397 {
1398         struct iscsi_session *session = conn->session;
1399
1400         if (session->state == ISCSI_STATE_FAILED)
1401                 return false;
1402
1403         if (conn->stop_stage == 0)
1404                 session->state = ISCSI_STATE_FAILED;
1405
1406         set_bit(ISCSI_CONN_FLAG_SUSPEND_TX, &conn->flags);
1407         set_bit(ISCSI_CONN_FLAG_SUSPEND_RX, &conn->flags);
1408         return true;
1409 }
1410
1411 void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err)
1412 {
1413         struct iscsi_session *session = conn->session;
1414         bool needs_evt;
1415
1416         spin_lock_bh(&session->frwd_lock);
1417         needs_evt = iscsi_set_conn_failed(conn);
1418         spin_unlock_bh(&session->frwd_lock);
1419
1420         if (needs_evt)
1421                 iscsi_conn_error_event(conn->cls_conn, err);
1422 }
1423 EXPORT_SYMBOL_GPL(iscsi_conn_failure);
1424
1425 static int iscsi_check_cmdsn_window_closed(struct iscsi_conn *conn)
1426 {
1427         struct iscsi_session *session = conn->session;
1428
1429         /*
1430          * Check for iSCSI window and take care of CmdSN wrap-around
1431          */
1432         if (!iscsi_sna_lte(session->queued_cmdsn, session->max_cmdsn)) {
1433                 ISCSI_DBG_SESSION(session, "iSCSI CmdSN closed. ExpCmdSn "
1434                                   "%u MaxCmdSN %u CmdSN %u/%u\n",
1435                                   session->exp_cmdsn, session->max_cmdsn,
1436                                   session->cmdsn, session->queued_cmdsn);
1437                 return -ENOSPC;
1438         }
1439         return 0;
1440 }
1441
1442 static int iscsi_xmit_task(struct iscsi_conn *conn, struct iscsi_task *task,
1443                            bool was_requeue)
1444 {
1445         int rc;
1446
1447         spin_lock_bh(&conn->session->back_lock);
1448
1449         if (!conn->task) {
1450                 /* Take a ref so we can access it after xmit_task() */
1451                 __iscsi_get_task(task);
1452         } else {
1453                 /* Already have a ref from when we failed to send it last call */
1454                 conn->task = NULL;
1455         }
1456
1457         /*
1458          * If this was a requeue for a R2T we have an extra ref on the task in
1459          * case a bad target sends a cmd rsp before we have handled the task.
1460          */
1461         if (was_requeue)
1462                 __iscsi_put_task(task);
1463
1464         /*
1465          * Do this after dropping the extra ref because if this was a requeue
1466          * it's removed from that list and cleanup_queued_task would miss it.
1467          */
1468         if (test_bit(ISCSI_CONN_FLAG_SUSPEND_TX, &conn->flags)) {
1469                 /*
1470                  * Save the task and ref in case we weren't cleaning up this
1471                  * task and get woken up again.
1472                  */
1473                 conn->task = task;
1474                 spin_unlock_bh(&conn->session->back_lock);
1475                 return -ENODATA;
1476         }
1477         spin_unlock_bh(&conn->session->back_lock);
1478
1479         spin_unlock_bh(&conn->session->frwd_lock);
1480         rc = conn->session->tt->xmit_task(task);
1481         spin_lock_bh(&conn->session->frwd_lock);
1482         if (!rc) {
1483                 /* done with this task */
1484                 task->last_xfer = jiffies;
1485         }
1486         /* regular RX path uses back_lock */
1487         spin_lock(&conn->session->back_lock);
1488         if (rc && task->state == ISCSI_TASK_RUNNING) {
1489                 /*
1490                  * get an extra ref that is released next time we access it
1491                  * as conn->task above.
1492                  */
1493                 __iscsi_get_task(task);
1494                 conn->task = task;
1495         }
1496
1497         __iscsi_put_task(task);
1498         spin_unlock(&conn->session->back_lock);
1499         return rc;
1500 }
1501
1502 /**
1503  * iscsi_requeue_task - requeue task to run from session workqueue
1504  * @task: task to requeue
1505  *
1506  * Callers must have taken a ref to the task that is going to be requeued.
1507  */
1508 void iscsi_requeue_task(struct iscsi_task *task)
1509 {
1510         struct iscsi_conn *conn = task->conn;
1511
1512         /*
1513          * this may be on the requeue list already if the xmit_task callout
1514          * is handling the r2ts while we are adding new ones
1515          */
1516         spin_lock_bh(&conn->session->frwd_lock);
1517         if (list_empty(&task->running)) {
1518                 list_add_tail(&task->running, &conn->requeue);
1519         } else {
1520                 /*
1521                  * Don't need the extra ref since it's already requeued and
1522                  * has a ref.
1523                  */
1524                 iscsi_put_task(task);
1525         }
1526         iscsi_conn_queue_xmit(conn);
1527         spin_unlock_bh(&conn->session->frwd_lock);
1528 }
1529 EXPORT_SYMBOL_GPL(iscsi_requeue_task);
1530
1531 /**
1532  * iscsi_data_xmit - xmit any command into the scheduled connection
1533  * @conn: iscsi connection
1534  *
1535  * Notes:
1536  *      The function can return -EAGAIN in which case the caller must
1537  *      re-schedule it again later or recover. '0' return code means
1538  *      successful xmit.
1539  **/
1540 static int iscsi_data_xmit(struct iscsi_conn *conn)
1541 {
1542         struct iscsi_task *task;
1543         int rc = 0;
1544
1545         spin_lock_bh(&conn->session->frwd_lock);
1546         if (test_bit(ISCSI_CONN_FLAG_SUSPEND_TX, &conn->flags)) {
1547                 ISCSI_DBG_SESSION(conn->session, "Tx suspended!\n");
1548                 spin_unlock_bh(&conn->session->frwd_lock);
1549                 return -ENODATA;
1550         }
1551
1552         if (conn->task) {
1553                 rc = iscsi_xmit_task(conn, conn->task, false);
1554                 if (rc)
1555                         goto done;
1556         }
1557
1558         /*
1559          * process mgmt pdus like nops before commands since we should
1560          * only have one nop-out as a ping from us and targets should not
1561          * overflow us with nop-ins
1562          */
1563 check_mgmt:
1564         while (!list_empty(&conn->mgmtqueue)) {
1565                 task = list_entry(conn->mgmtqueue.next, struct iscsi_task,
1566                                   running);
1567                 list_del_init(&task->running);
1568                 if (iscsi_prep_mgmt_task(conn, task)) {
1569                         /* regular RX path uses back_lock */
1570                         spin_lock_bh(&conn->session->back_lock);
1571                         __iscsi_put_task(task);
1572                         spin_unlock_bh(&conn->session->back_lock);
1573                         continue;
1574                 }
1575                 rc = iscsi_xmit_task(conn, task, false);
1576                 if (rc)
1577                         goto done;
1578         }
1579
1580         /* process pending command queue */
1581         while (!list_empty(&conn->cmdqueue)) {
1582                 task = list_entry(conn->cmdqueue.next, struct iscsi_task,
1583                                   running);
1584                 list_del_init(&task->running);
1585                 if (conn->session->state == ISCSI_STATE_LOGGING_OUT) {
1586                         fail_scsi_task(task, DID_IMM_RETRY);
1587                         continue;
1588                 }
1589                 rc = iscsi_prep_scsi_cmd_pdu(task);
1590                 if (rc) {
1591                         if (rc == -ENOMEM || rc == -EACCES)
1592                                 fail_scsi_task(task, DID_IMM_RETRY);
1593                         else
1594                                 fail_scsi_task(task, DID_ABORT);
1595                         continue;
1596                 }
1597                 rc = iscsi_xmit_task(conn, task, false);
1598                 if (rc)
1599                         goto done;
1600                 /*
1601                  * we could continuously get new task requests so
1602                  * we need to check the mgmt queue for nops that need to
1603                  * be sent to aviod starvation
1604                  */
1605                 if (!list_empty(&conn->mgmtqueue))
1606                         goto check_mgmt;
1607         }
1608
1609         while (!list_empty(&conn->requeue)) {
1610                 /*
1611                  * we always do fastlogout - conn stop code will clean up.
1612                  */
1613                 if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
1614                         break;
1615
1616                 task = list_entry(conn->requeue.next, struct iscsi_task,
1617                                   running);
1618
1619                 if (iscsi_check_tmf_restrictions(task, ISCSI_OP_SCSI_DATA_OUT))
1620                         break;
1621
1622                 list_del_init(&task->running);
1623                 rc = iscsi_xmit_task(conn, task, true);
1624                 if (rc)
1625                         goto done;
1626                 if (!list_empty(&conn->mgmtqueue))
1627                         goto check_mgmt;
1628         }
1629         spin_unlock_bh(&conn->session->frwd_lock);
1630         return -ENODATA;
1631
1632 done:
1633         spin_unlock_bh(&conn->session->frwd_lock);
1634         return rc;
1635 }
1636
1637 static void iscsi_xmitworker(struct work_struct *work)
1638 {
1639         struct iscsi_conn *conn =
1640                 container_of(work, struct iscsi_conn, xmitwork);
1641         int rc;
1642         /*
1643          * serialize Xmit worker on a per-connection basis.
1644          */
1645         do {
1646                 rc = iscsi_data_xmit(conn);
1647         } while (rc >= 0 || rc == -EAGAIN);
1648 }
1649
1650 static inline struct iscsi_task *iscsi_alloc_task(struct iscsi_conn *conn,
1651                                                   struct scsi_cmnd *sc)
1652 {
1653         struct iscsi_task *task;
1654
1655         if (!kfifo_out(&conn->session->cmdpool.queue,
1656                          (void *) &task, sizeof(void *)))
1657                 return NULL;
1658
1659         sc->SCp.phase = conn->session->age;
1660         sc->SCp.ptr = (char *) task;
1661
1662         refcount_set(&task->refcount, 1);
1663         task->state = ISCSI_TASK_PENDING;
1664         task->conn = conn;
1665         task->sc = sc;
1666         task->have_checked_conn = false;
1667         task->last_timeout = jiffies;
1668         task->last_xfer = jiffies;
1669         task->protected = false;
1670         INIT_LIST_HEAD(&task->running);
1671         return task;
1672 }
1673
1674 enum {
1675         FAILURE_BAD_HOST = 1,
1676         FAILURE_SESSION_FAILED,
1677         FAILURE_SESSION_FREED,
1678         FAILURE_WINDOW_CLOSED,
1679         FAILURE_OOM,
1680         FAILURE_SESSION_TERMINATE,
1681         FAILURE_SESSION_IN_RECOVERY,
1682         FAILURE_SESSION_RECOVERY_TIMEOUT,
1683         FAILURE_SESSION_LOGGING_OUT,
1684         FAILURE_SESSION_NOT_READY,
1685 };
1686
1687 int iscsi_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *sc)
1688 {
1689         struct iscsi_cls_session *cls_session;
1690         struct iscsi_host *ihost;
1691         int reason = 0;
1692         struct iscsi_session *session;
1693         struct iscsi_conn *conn;
1694         struct iscsi_task *task = NULL;
1695
1696         sc->result = 0;
1697         sc->SCp.ptr = NULL;
1698
1699         ihost = shost_priv(host);
1700
1701         cls_session = starget_to_session(scsi_target(sc->device));
1702         session = cls_session->dd_data;
1703         spin_lock_bh(&session->frwd_lock);
1704
1705         reason = iscsi_session_chkready(cls_session);
1706         if (reason) {
1707                 sc->result = reason;
1708                 goto fault;
1709         }
1710
1711         if (session->state != ISCSI_STATE_LOGGED_IN) {
1712                 /*
1713                  * to handle the race between when we set the recovery state
1714                  * and block the session we requeue here (commands could
1715                  * be entering our queuecommand while a block is starting
1716                  * up because the block code is not locked)
1717                  */
1718                 switch (session->state) {
1719                 case ISCSI_STATE_FAILED:
1720                         /*
1721                          * cmds should fail during shutdown, if the session
1722                          * state is bad, allowing completion to happen
1723                          */
1724                         if (unlikely(system_state != SYSTEM_RUNNING)) {
1725                                 reason = FAILURE_SESSION_FAILED;
1726                                 sc->result = DID_NO_CONNECT << 16;
1727                                 break;
1728                         }
1729                         fallthrough;
1730                 case ISCSI_STATE_IN_RECOVERY:
1731                         reason = FAILURE_SESSION_IN_RECOVERY;
1732                         sc->result = DID_IMM_RETRY << 16;
1733                         break;
1734                 case ISCSI_STATE_LOGGING_OUT:
1735                         reason = FAILURE_SESSION_LOGGING_OUT;
1736                         sc->result = DID_IMM_RETRY << 16;
1737                         break;
1738                 case ISCSI_STATE_RECOVERY_FAILED:
1739                         reason = FAILURE_SESSION_RECOVERY_TIMEOUT;
1740                         sc->result = DID_TRANSPORT_FAILFAST << 16;
1741                         break;
1742                 case ISCSI_STATE_TERMINATE:
1743                         reason = FAILURE_SESSION_TERMINATE;
1744                         sc->result = DID_NO_CONNECT << 16;
1745                         break;
1746                 default:
1747                         reason = FAILURE_SESSION_FREED;
1748                         sc->result = DID_NO_CONNECT << 16;
1749                 }
1750                 goto fault;
1751         }
1752
1753         conn = session->leadconn;
1754         if (!conn) {
1755                 reason = FAILURE_SESSION_FREED;
1756                 sc->result = DID_NO_CONNECT << 16;
1757                 goto fault;
1758         }
1759
1760         if (test_bit(ISCSI_CONN_FLAG_SUSPEND_TX, &conn->flags)) {
1761                 reason = FAILURE_SESSION_IN_RECOVERY;
1762                 sc->result = DID_REQUEUE << 16;
1763                 goto fault;
1764         }
1765
1766         if (iscsi_check_cmdsn_window_closed(conn)) {
1767                 reason = FAILURE_WINDOW_CLOSED;
1768                 goto reject;
1769         }
1770
1771         task = iscsi_alloc_task(conn, sc);
1772         if (!task) {
1773                 reason = FAILURE_OOM;
1774                 goto reject;
1775         }
1776
1777         if (!ihost->workq) {
1778                 reason = iscsi_prep_scsi_cmd_pdu(task);
1779                 if (reason) {
1780                         if (reason == -ENOMEM ||  reason == -EACCES) {
1781                                 reason = FAILURE_OOM;
1782                                 goto prepd_reject;
1783                         } else {
1784                                 sc->result = DID_ABORT << 16;
1785                                 goto prepd_fault;
1786                         }
1787                 }
1788                 if (session->tt->xmit_task(task)) {
1789                         session->cmdsn--;
1790                         reason = FAILURE_SESSION_NOT_READY;
1791                         goto prepd_reject;
1792                 }
1793         } else {
1794                 list_add_tail(&task->running, &conn->cmdqueue);
1795                 iscsi_conn_queue_xmit(conn);
1796         }
1797
1798         session->queued_cmdsn++;
1799         spin_unlock_bh(&session->frwd_lock);
1800         return 0;
1801
1802 prepd_reject:
1803         spin_lock_bh(&session->back_lock);
1804         iscsi_complete_task(task, ISCSI_TASK_REQUEUE_SCSIQ);
1805         spin_unlock_bh(&session->back_lock);
1806 reject:
1807         spin_unlock_bh(&session->frwd_lock);
1808         ISCSI_DBG_SESSION(session, "cmd 0x%x rejected (%d)\n",
1809                           sc->cmnd[0], reason);
1810         return SCSI_MLQUEUE_TARGET_BUSY;
1811
1812 prepd_fault:
1813         spin_lock_bh(&session->back_lock);
1814         iscsi_complete_task(task, ISCSI_TASK_REQUEUE_SCSIQ);
1815         spin_unlock_bh(&session->back_lock);
1816 fault:
1817         spin_unlock_bh(&session->frwd_lock);
1818         ISCSI_DBG_SESSION(session, "iscsi: cmd 0x%x is not queued (%d)\n",
1819                           sc->cmnd[0], reason);
1820         scsi_set_resid(sc, scsi_bufflen(sc));
1821         sc->scsi_done(sc);
1822         return 0;
1823 }
1824 EXPORT_SYMBOL_GPL(iscsi_queuecommand);
1825
1826 int iscsi_target_alloc(struct scsi_target *starget)
1827 {
1828         struct iscsi_cls_session *cls_session = starget_to_session(starget);
1829         struct iscsi_session *session = cls_session->dd_data;
1830
1831         starget->can_queue = session->scsi_cmds_max;
1832         return 0;
1833 }
1834 EXPORT_SYMBOL_GPL(iscsi_target_alloc);
1835
1836 static void iscsi_tmf_timedout(struct timer_list *t)
1837 {
1838         struct iscsi_session *session = from_timer(session, t, tmf_timer);
1839
1840         spin_lock(&session->frwd_lock);
1841         if (session->tmf_state == TMF_QUEUED) {
1842                 session->tmf_state = TMF_TIMEDOUT;
1843                 ISCSI_DBG_EH(session, "tmf timedout\n");
1844                 /* unblock eh_abort() */
1845                 wake_up(&session->ehwait);
1846         }
1847         spin_unlock(&session->frwd_lock);
1848 }
1849
1850 static int iscsi_exec_task_mgmt_fn(struct iscsi_conn *conn,
1851                                    struct iscsi_tm *hdr, int age,
1852                                    int timeout)
1853         __must_hold(&session->frwd_lock)
1854 {
1855         struct iscsi_session *session = conn->session;
1856         struct iscsi_task *task;
1857
1858         task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)hdr,
1859                                       NULL, 0);
1860         if (!task) {
1861                 spin_unlock_bh(&session->frwd_lock);
1862                 iscsi_conn_printk(KERN_ERR, conn, "Could not send TMF.\n");
1863                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1864                 spin_lock_bh(&session->frwd_lock);
1865                 return -EPERM;
1866         }
1867         conn->tmfcmd_pdus_cnt++;
1868         session->tmf_timer.expires = timeout * HZ + jiffies;
1869         add_timer(&session->tmf_timer);
1870         ISCSI_DBG_EH(session, "tmf set timeout\n");
1871
1872         spin_unlock_bh(&session->frwd_lock);
1873         mutex_unlock(&session->eh_mutex);
1874
1875         /*
1876          * block eh thread until:
1877          *
1878          * 1) tmf response
1879          * 2) tmf timeout
1880          * 3) session is terminated or restarted or userspace has
1881          * given up on recovery
1882          */
1883         wait_event_interruptible(session->ehwait, age != session->age ||
1884                                  session->state != ISCSI_STATE_LOGGED_IN ||
1885                                  session->tmf_state != TMF_QUEUED);
1886         if (signal_pending(current))
1887                 flush_signals(current);
1888         del_timer_sync(&session->tmf_timer);
1889
1890         mutex_lock(&session->eh_mutex);
1891         spin_lock_bh(&session->frwd_lock);
1892         /* if the session drops it will clean up the task */
1893         if (age != session->age ||
1894             session->state != ISCSI_STATE_LOGGED_IN)
1895                 return -ENOTCONN;
1896         return 0;
1897 }
1898
1899 /*
1900  * Fail commands. session frwd lock held and xmit thread flushed.
1901  */
1902 static void fail_scsi_tasks(struct iscsi_conn *conn, u64 lun, int error)
1903 {
1904         struct iscsi_session *session = conn->session;
1905         struct iscsi_task *task;
1906         int i;
1907
1908         spin_lock_bh(&session->back_lock);
1909         for (i = 0; i < session->cmds_max; i++) {
1910                 task = session->cmds[i];
1911                 if (!task->sc || task->state == ISCSI_TASK_FREE)
1912                         continue;
1913
1914                 if (lun != -1 && lun != task->sc->device->lun)
1915                         continue;
1916
1917                 __iscsi_get_task(task);
1918                 spin_unlock_bh(&session->back_lock);
1919
1920                 ISCSI_DBG_SESSION(session,
1921                                   "failing sc %p itt 0x%x state %d\n",
1922                                   task->sc, task->itt, task->state);
1923                 fail_scsi_task(task, error);
1924
1925                 spin_unlock_bh(&session->frwd_lock);
1926                 iscsi_put_task(task);
1927                 spin_lock_bh(&session->frwd_lock);
1928
1929                 spin_lock_bh(&session->back_lock);
1930         }
1931
1932         spin_unlock_bh(&session->back_lock);
1933 }
1934
1935 /**
1936  * iscsi_suspend_queue - suspend iscsi_queuecommand
1937  * @conn: iscsi conn to stop queueing IO on
1938  *
1939  * This grabs the session frwd_lock to make sure no one is in
1940  * xmit_task/queuecommand, and then sets suspend to prevent
1941  * new commands from being queued. This only needs to be called
1942  * by offload drivers that need to sync a path like ep disconnect
1943  * with the iscsi_queuecommand/xmit_task. To start IO again libiscsi
1944  * will call iscsi_start_tx and iscsi_unblock_session when in FFP.
1945  */
1946 void iscsi_suspend_queue(struct iscsi_conn *conn)
1947 {
1948         spin_lock_bh(&conn->session->frwd_lock);
1949         set_bit(ISCSI_CONN_FLAG_SUSPEND_TX, &conn->flags);
1950         spin_unlock_bh(&conn->session->frwd_lock);
1951 }
1952 EXPORT_SYMBOL_GPL(iscsi_suspend_queue);
1953
1954 /**
1955  * iscsi_suspend_tx - suspend iscsi_data_xmit
1956  * @conn: iscsi conn to stop processing IO on.
1957  *
1958  * This function sets the suspend bit to prevent iscsi_data_xmit
1959  * from sending new IO, and if work is queued on the xmit thread
1960  * it will wait for it to be completed.
1961  */
1962 void iscsi_suspend_tx(struct iscsi_conn *conn)
1963 {
1964         struct Scsi_Host *shost = conn->session->host;
1965         struct iscsi_host *ihost = shost_priv(shost);
1966
1967         set_bit(ISCSI_CONN_FLAG_SUSPEND_TX, &conn->flags);
1968         if (ihost->workq)
1969                 flush_work(&conn->xmitwork);
1970 }
1971 EXPORT_SYMBOL_GPL(iscsi_suspend_tx);
1972
1973 static void iscsi_start_tx(struct iscsi_conn *conn)
1974 {
1975         clear_bit(ISCSI_CONN_FLAG_SUSPEND_TX, &conn->flags);
1976         iscsi_conn_queue_xmit(conn);
1977 }
1978
1979 /**
1980  * iscsi_suspend_rx - Prevent recvwork from running again.
1981  * @conn: iscsi conn to stop.
1982  */
1983 void iscsi_suspend_rx(struct iscsi_conn *conn)
1984 {
1985         struct Scsi_Host *shost = conn->session->host;
1986         struct iscsi_host *ihost = shost_priv(shost);
1987
1988         set_bit(ISCSI_CONN_FLAG_SUSPEND_RX, &conn->flags);
1989         if (ihost->workq)
1990                 flush_work(&conn->recvwork);
1991 }
1992 EXPORT_SYMBOL_GPL(iscsi_suspend_rx);
1993
1994 /*
1995  * We want to make sure a ping is in flight. It has timed out.
1996  * And we are not busy processing a pdu that is making
1997  * progress but got started before the ping and is taking a while
1998  * to complete so the ping is just stuck behind it in a queue.
1999  */
2000 static int iscsi_has_ping_timed_out(struct iscsi_conn *conn)
2001 {
2002         if (READ_ONCE(conn->ping_task) &&
2003             time_before_eq(conn->last_recv + (conn->recv_timeout * HZ) +
2004                            (conn->ping_timeout * HZ), jiffies))
2005                 return 1;
2006         else
2007                 return 0;
2008 }
2009
2010 enum blk_eh_timer_return iscsi_eh_cmd_timed_out(struct scsi_cmnd *sc)
2011 {
2012         enum blk_eh_timer_return rc = BLK_EH_DONE;
2013         struct iscsi_task *task = NULL, *running_task;
2014         struct iscsi_cls_session *cls_session;
2015         struct iscsi_session *session;
2016         struct iscsi_conn *conn;
2017         int i;
2018
2019         cls_session = starget_to_session(scsi_target(sc->device));
2020         session = cls_session->dd_data;
2021
2022         ISCSI_DBG_EH(session, "scsi cmd %p timedout\n", sc);
2023
2024         spin_lock_bh(&session->frwd_lock);
2025         spin_lock(&session->back_lock);
2026         task = (struct iscsi_task *)sc->SCp.ptr;
2027         if (!task) {
2028                 /*
2029                  * Raced with completion. Blk layer has taken ownership
2030                  * so let timeout code complete it now.
2031                  */
2032                 rc = BLK_EH_DONE;
2033                 spin_unlock(&session->back_lock);
2034                 goto done;
2035         }
2036         __iscsi_get_task(task);
2037         spin_unlock(&session->back_lock);
2038
2039         if (session->state != ISCSI_STATE_LOGGED_IN) {
2040                 /*
2041                  * During shutdown, if session is prematurely disconnected,
2042                  * recovery won't happen and there will be hung cmds. Not
2043                  * handling cmds would trigger EH, also bad in this case.
2044                  * Instead, handle cmd, allow completion to happen and let
2045                  * upper layer to deal with the result.
2046                  */
2047                 if (unlikely(system_state != SYSTEM_RUNNING)) {
2048                         sc->result = DID_NO_CONNECT << 16;
2049                         ISCSI_DBG_EH(session, "sc on shutdown, handled\n");
2050                         rc = BLK_EH_DONE;
2051                         goto done;
2052                 }
2053                 /*
2054                  * We are probably in the middle of iscsi recovery so let
2055                  * that complete and handle the error.
2056                  */
2057                 rc = BLK_EH_RESET_TIMER;
2058                 goto done;
2059         }
2060
2061         conn = session->leadconn;
2062         if (!conn) {
2063                 /* In the middle of shuting down */
2064                 rc = BLK_EH_RESET_TIMER;
2065                 goto done;
2066         }
2067
2068         /*
2069          * If we have sent (at least queued to the network layer) a pdu or
2070          * recvd one for the task since the last timeout ask for
2071          * more time. If on the next timeout we have not made progress
2072          * we can check if it is the task or connection when we send the
2073          * nop as a ping.
2074          */
2075         if (time_after(task->last_xfer, task->last_timeout)) {
2076                 ISCSI_DBG_EH(session, "Command making progress. Asking "
2077                              "scsi-ml for more time to complete. "
2078                              "Last data xfer at %lu. Last timeout was at "
2079                              "%lu\n.", task->last_xfer, task->last_timeout);
2080                 task->have_checked_conn = false;
2081                 rc = BLK_EH_RESET_TIMER;
2082                 goto done;
2083         }
2084
2085         if (!conn->recv_timeout && !conn->ping_timeout)
2086                 goto done;
2087         /*
2088          * if the ping timedout then we are in the middle of cleaning up
2089          * and can let the iscsi eh handle it
2090          */
2091         if (iscsi_has_ping_timed_out(conn)) {
2092                 rc = BLK_EH_RESET_TIMER;
2093                 goto done;
2094         }
2095
2096         spin_lock(&session->back_lock);
2097         for (i = 0; i < conn->session->cmds_max; i++) {
2098                 running_task = conn->session->cmds[i];
2099                 if (!running_task->sc || running_task == task ||
2100                      running_task->state != ISCSI_TASK_RUNNING)
2101                         continue;
2102
2103                 /*
2104                  * Only check if cmds started before this one have made
2105                  * progress, or this could never fail
2106                  */
2107                 if (time_after(running_task->sc->jiffies_at_alloc,
2108                                task->sc->jiffies_at_alloc))
2109                         continue;
2110
2111                 if (time_after(running_task->last_xfer, task->last_timeout)) {
2112                         /*
2113                          * This task has not made progress, but a task
2114                          * started before us has transferred data since
2115                          * we started/last-checked. We could be queueing
2116                          * too many tasks or the LU is bad.
2117                          *
2118                          * If the device is bad the cmds ahead of us on
2119                          * other devs will complete, and this loop will
2120                          * eventually fail starting the scsi eh.
2121                          */
2122                         ISCSI_DBG_EH(session, "Command has not made progress "
2123                                      "but commands ahead of it have. "
2124                                      "Asking scsi-ml for more time to "
2125                                      "complete. Our last xfer vs running task "
2126                                      "last xfer %lu/%lu. Last check %lu.\n",
2127                                      task->last_xfer, running_task->last_xfer,
2128                                      task->last_timeout);
2129                         spin_unlock(&session->back_lock);
2130                         rc = BLK_EH_RESET_TIMER;
2131                         goto done;
2132                 }
2133         }
2134         spin_unlock(&session->back_lock);
2135
2136         /* Assumes nop timeout is shorter than scsi cmd timeout */
2137         if (task->have_checked_conn)
2138                 goto done;
2139
2140         /*
2141          * Checking the transport already or nop from a cmd timeout still
2142          * running
2143          */
2144         if (READ_ONCE(conn->ping_task)) {
2145                 task->have_checked_conn = true;
2146                 rc = BLK_EH_RESET_TIMER;
2147                 goto done;
2148         }
2149
2150         /* Make sure there is a transport check done */
2151         iscsi_send_nopout(conn, NULL);
2152         task->have_checked_conn = true;
2153         rc = BLK_EH_RESET_TIMER;
2154
2155 done:
2156         spin_unlock_bh(&session->frwd_lock);
2157
2158         if (task) {
2159                 task->last_timeout = jiffies;
2160                 iscsi_put_task(task);
2161         }
2162         ISCSI_DBG_EH(session, "return %s\n", rc == BLK_EH_RESET_TIMER ?
2163                      "timer reset" : "shutdown or nh");
2164         return rc;
2165 }
2166 EXPORT_SYMBOL_GPL(iscsi_eh_cmd_timed_out);
2167
2168 static void iscsi_check_transport_timeouts(struct timer_list *t)
2169 {
2170         struct iscsi_conn *conn = from_timer(conn, t, transport_timer);
2171         struct iscsi_session *session = conn->session;
2172         unsigned long recv_timeout, next_timeout = 0, last_recv;
2173
2174         spin_lock(&session->frwd_lock);
2175         if (session->state != ISCSI_STATE_LOGGED_IN)
2176                 goto done;
2177
2178         recv_timeout = conn->recv_timeout;
2179         if (!recv_timeout)
2180                 goto done;
2181
2182         recv_timeout *= HZ;
2183         last_recv = conn->last_recv;
2184
2185         if (iscsi_has_ping_timed_out(conn)) {
2186                 iscsi_conn_printk(KERN_ERR, conn, "ping timeout of %d secs "
2187                                   "expired, recv timeout %d, last rx %lu, "
2188                                   "last ping %lu, now %lu\n",
2189                                   conn->ping_timeout, conn->recv_timeout,
2190                                   last_recv, conn->last_ping, jiffies);
2191                 spin_unlock(&session->frwd_lock);
2192                 iscsi_conn_failure(conn, ISCSI_ERR_NOP_TIMEDOUT);
2193                 return;
2194         }
2195
2196         if (time_before_eq(last_recv + recv_timeout, jiffies)) {
2197                 /* send a ping to try to provoke some traffic */
2198                 ISCSI_DBG_CONN(conn, "Sending nopout as ping\n");
2199                 if (iscsi_send_nopout(conn, NULL))
2200                         next_timeout = jiffies + (1 * HZ);
2201                 else
2202                         next_timeout = conn->last_ping + (conn->ping_timeout * HZ);
2203         } else
2204                 next_timeout = last_recv + recv_timeout;
2205
2206         ISCSI_DBG_CONN(conn, "Setting next tmo %lu\n", next_timeout);
2207         mod_timer(&conn->transport_timer, next_timeout);
2208 done:
2209         spin_unlock(&session->frwd_lock);
2210 }
2211
2212 /**
2213  * iscsi_conn_unbind - prevent queueing to conn.
2214  * @cls_conn: iscsi conn ep is bound to.
2215  * @is_active: is the conn in use for boot or is this for EH/termination
2216  *
2217  * This must be called by drivers implementing the ep_disconnect callout.
2218  * It disables queueing to the connection from libiscsi in preparation for
2219  * an ep_disconnect call.
2220  */
2221 void iscsi_conn_unbind(struct iscsi_cls_conn *cls_conn, bool is_active)
2222 {
2223         struct iscsi_session *session;
2224         struct iscsi_conn *conn;
2225
2226         if (!cls_conn)
2227                 return;
2228
2229         conn = cls_conn->dd_data;
2230         session = conn->session;
2231         /*
2232          * Wait for iscsi_eh calls to exit. We don't wait for the tmf to
2233          * complete or timeout. The caller just wants to know what's running
2234          * is everything that needs to be cleaned up, and no cmds will be
2235          * queued.
2236          */
2237         mutex_lock(&session->eh_mutex);
2238
2239         iscsi_suspend_queue(conn);
2240         iscsi_suspend_tx(conn);
2241
2242         spin_lock_bh(&session->frwd_lock);
2243         clear_bit(ISCSI_CONN_FLAG_BOUND, &conn->flags);
2244
2245         if (!is_active) {
2246                 /*
2247                  * if logout timed out before userspace could even send a PDU
2248                  * the state might still be in ISCSI_STATE_LOGGED_IN and
2249                  * allowing new cmds and TMFs.
2250                  */
2251                 if (session->state == ISCSI_STATE_LOGGED_IN)
2252                         iscsi_set_conn_failed(conn);
2253         }
2254         spin_unlock_bh(&session->frwd_lock);
2255         mutex_unlock(&session->eh_mutex);
2256 }
2257 EXPORT_SYMBOL_GPL(iscsi_conn_unbind);
2258
2259 static void iscsi_prep_abort_task_pdu(struct iscsi_task *task,
2260                                       struct iscsi_tm *hdr)
2261 {
2262         memset(hdr, 0, sizeof(*hdr));
2263         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2264         hdr->flags = ISCSI_TM_FUNC_ABORT_TASK & ISCSI_FLAG_TM_FUNC_MASK;
2265         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2266         hdr->lun = task->lun;
2267         hdr->rtt = task->hdr_itt;
2268         hdr->refcmdsn = task->cmdsn;
2269 }
2270
2271 int iscsi_eh_abort(struct scsi_cmnd *sc)
2272 {
2273         struct iscsi_cls_session *cls_session;
2274         struct iscsi_session *session;
2275         struct iscsi_conn *conn;
2276         struct iscsi_task *task;
2277         struct iscsi_tm *hdr;
2278         int age;
2279
2280         cls_session = starget_to_session(scsi_target(sc->device));
2281         session = cls_session->dd_data;
2282
2283         ISCSI_DBG_EH(session, "aborting sc %p\n", sc);
2284
2285         mutex_lock(&session->eh_mutex);
2286         spin_lock_bh(&session->frwd_lock);
2287         /*
2288          * if session was ISCSI_STATE_IN_RECOVERY then we may not have
2289          * got the command.
2290          */
2291         if (!sc->SCp.ptr) {
2292                 ISCSI_DBG_EH(session, "sc never reached iscsi layer or "
2293                                       "it completed.\n");
2294                 spin_unlock_bh(&session->frwd_lock);
2295                 mutex_unlock(&session->eh_mutex);
2296                 return SUCCESS;
2297         }
2298
2299         /*
2300          * If we are not logged in or we have started a new session
2301          * then let the host reset code handle this
2302          */
2303         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN ||
2304             sc->SCp.phase != session->age) {
2305                 spin_unlock_bh(&session->frwd_lock);
2306                 mutex_unlock(&session->eh_mutex);
2307                 ISCSI_DBG_EH(session, "failing abort due to dropped "
2308                                   "session.\n");
2309                 return FAILED;
2310         }
2311
2312         spin_lock(&session->back_lock);
2313         task = (struct iscsi_task *)sc->SCp.ptr;
2314         if (!task || !task->sc) {
2315                 /* task completed before time out */
2316                 ISCSI_DBG_EH(session, "sc completed while abort in progress\n");
2317
2318                 spin_unlock(&session->back_lock);
2319                 spin_unlock_bh(&session->frwd_lock);
2320                 mutex_unlock(&session->eh_mutex);
2321                 return SUCCESS;
2322         }
2323
2324         conn = session->leadconn;
2325         iscsi_get_conn(conn->cls_conn);
2326         conn->eh_abort_cnt++;
2327         age = session->age;
2328
2329         ISCSI_DBG_EH(session, "aborting [sc %p itt 0x%x]\n", sc, task->itt);
2330         __iscsi_get_task(task);
2331         spin_unlock(&session->back_lock);
2332
2333         if (task->state == ISCSI_TASK_PENDING) {
2334                 fail_scsi_task(task, DID_ABORT);
2335                 goto success;
2336         }
2337
2338         /* only have one tmf outstanding at a time */
2339         if (session->tmf_state != TMF_INITIAL)
2340                 goto failed;
2341         session->tmf_state = TMF_QUEUED;
2342
2343         hdr = &session->tmhdr;
2344         iscsi_prep_abort_task_pdu(task, hdr);
2345
2346         if (iscsi_exec_task_mgmt_fn(conn, hdr, age, session->abort_timeout))
2347                 goto failed;
2348
2349         switch (session->tmf_state) {
2350         case TMF_SUCCESS:
2351                 spin_unlock_bh(&session->frwd_lock);
2352                 /*
2353                  * stop tx side incase the target had sent a abort rsp but
2354                  * the initiator was still writing out data.
2355                  */
2356                 iscsi_suspend_tx(conn);
2357                 /*
2358                  * we do not stop the recv side because targets have been
2359                  * good and have never sent us a successful tmf response
2360                  * then sent more data for the cmd.
2361                  */
2362                 spin_lock_bh(&session->frwd_lock);
2363                 fail_scsi_task(task, DID_ABORT);
2364                 session->tmf_state = TMF_INITIAL;
2365                 memset(hdr, 0, sizeof(*hdr));
2366                 spin_unlock_bh(&session->frwd_lock);
2367                 iscsi_start_tx(conn);
2368                 goto success_unlocked;
2369         case TMF_TIMEDOUT:
2370                 session->running_aborted_task = task;
2371                 spin_unlock_bh(&session->frwd_lock);
2372                 iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2373                 goto failed_unlocked;
2374         case TMF_NOT_FOUND:
2375                 if (iscsi_task_is_completed(task)) {
2376                         session->tmf_state = TMF_INITIAL;
2377                         memset(hdr, 0, sizeof(*hdr));
2378                         /* task completed before tmf abort response */
2379                         ISCSI_DBG_EH(session, "sc completed while abort in "
2380                                               "progress\n");
2381                         goto success;
2382                 }
2383                 fallthrough;
2384         default:
2385                 session->tmf_state = TMF_INITIAL;
2386                 goto failed;
2387         }
2388
2389 success:
2390         spin_unlock_bh(&session->frwd_lock);
2391 success_unlocked:
2392         ISCSI_DBG_EH(session, "abort success [sc %p itt 0x%x]\n",
2393                      sc, task->itt);
2394         iscsi_put_task(task);
2395         iscsi_put_conn(conn->cls_conn);
2396         mutex_unlock(&session->eh_mutex);
2397         return SUCCESS;
2398
2399 failed:
2400         spin_unlock_bh(&session->frwd_lock);
2401 failed_unlocked:
2402         ISCSI_DBG_EH(session, "abort failed [sc %p itt 0x%x]\n", sc,
2403                      task ? task->itt : 0);
2404         /*
2405          * The driver might be accessing the task so hold the ref. The conn
2406          * stop cleanup will drop the ref after ep_disconnect so we know the
2407          * driver's no longer touching the task.
2408          */
2409         if (!session->running_aborted_task)
2410                 iscsi_put_task(task);
2411
2412         iscsi_put_conn(conn->cls_conn);
2413         mutex_unlock(&session->eh_mutex);
2414         return FAILED;
2415 }
2416 EXPORT_SYMBOL_GPL(iscsi_eh_abort);
2417
2418 static void iscsi_prep_lun_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
2419 {
2420         memset(hdr, 0, sizeof(*hdr));
2421         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2422         hdr->flags = ISCSI_TM_FUNC_LOGICAL_UNIT_RESET & ISCSI_FLAG_TM_FUNC_MASK;
2423         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2424         int_to_scsilun(sc->device->lun, &hdr->lun);
2425         hdr->rtt = RESERVED_ITT;
2426 }
2427
2428 int iscsi_eh_device_reset(struct scsi_cmnd *sc)
2429 {
2430         struct iscsi_cls_session *cls_session;
2431         struct iscsi_session *session;
2432         struct iscsi_conn *conn;
2433         struct iscsi_tm *hdr;
2434         int rc = FAILED;
2435
2436         cls_session = starget_to_session(scsi_target(sc->device));
2437         session = cls_session->dd_data;
2438
2439         ISCSI_DBG_EH(session, "LU Reset [sc %p lun %llu]\n", sc,
2440                      sc->device->lun);
2441
2442         mutex_lock(&session->eh_mutex);
2443         spin_lock_bh(&session->frwd_lock);
2444         /*
2445          * Just check if we are not logged in. We cannot check for
2446          * the phase because the reset could come from a ioctl.
2447          */
2448         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
2449                 goto unlock;
2450         conn = session->leadconn;
2451
2452         /* only have one tmf outstanding at a time */
2453         if (session->tmf_state != TMF_INITIAL)
2454                 goto unlock;
2455         session->tmf_state = TMF_QUEUED;
2456
2457         hdr = &session->tmhdr;
2458         iscsi_prep_lun_reset_pdu(sc, hdr);
2459
2460         if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
2461                                     session->lu_reset_timeout)) {
2462                 rc = FAILED;
2463                 goto unlock;
2464         }
2465
2466         switch (session->tmf_state) {
2467         case TMF_SUCCESS:
2468                 break;
2469         case TMF_TIMEDOUT:
2470                 spin_unlock_bh(&session->frwd_lock);
2471                 iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2472                 goto done;
2473         default:
2474                 session->tmf_state = TMF_INITIAL;
2475                 goto unlock;
2476         }
2477
2478         rc = SUCCESS;
2479         spin_unlock_bh(&session->frwd_lock);
2480
2481         iscsi_suspend_tx(conn);
2482
2483         spin_lock_bh(&session->frwd_lock);
2484         memset(hdr, 0, sizeof(*hdr));
2485         fail_scsi_tasks(conn, sc->device->lun, DID_ERROR);
2486         session->tmf_state = TMF_INITIAL;
2487         spin_unlock_bh(&session->frwd_lock);
2488
2489         iscsi_start_tx(conn);
2490         goto done;
2491
2492 unlock:
2493         spin_unlock_bh(&session->frwd_lock);
2494 done:
2495         ISCSI_DBG_EH(session, "dev reset result = %s\n",
2496                      rc == SUCCESS ? "SUCCESS" : "FAILED");
2497         mutex_unlock(&session->eh_mutex);
2498         return rc;
2499 }
2500 EXPORT_SYMBOL_GPL(iscsi_eh_device_reset);
2501
2502 void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
2503 {
2504         struct iscsi_session *session = cls_session->dd_data;
2505
2506         spin_lock_bh(&session->frwd_lock);
2507         if (session->state != ISCSI_STATE_LOGGED_IN) {
2508                 session->state = ISCSI_STATE_RECOVERY_FAILED;
2509                 wake_up(&session->ehwait);
2510         }
2511         spin_unlock_bh(&session->frwd_lock);
2512 }
2513 EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
2514
2515 /**
2516  * iscsi_eh_session_reset - drop session and attempt relogin
2517  * @sc: scsi command
2518  *
2519  * This function will wait for a relogin, session termination from
2520  * userspace, or a recovery/replacement timeout.
2521  */
2522 int iscsi_eh_session_reset(struct scsi_cmnd *sc)
2523 {
2524         struct iscsi_cls_session *cls_session;
2525         struct iscsi_session *session;
2526         struct iscsi_conn *conn;
2527
2528         cls_session = starget_to_session(scsi_target(sc->device));
2529         session = cls_session->dd_data;
2530
2531         mutex_lock(&session->eh_mutex);
2532         spin_lock_bh(&session->frwd_lock);
2533         if (session->state == ISCSI_STATE_TERMINATE) {
2534 failed:
2535                 ISCSI_DBG_EH(session,
2536                              "failing session reset: Could not log back into "
2537                              "%s [age %d]\n", session->targetname,
2538                              session->age);
2539                 spin_unlock_bh(&session->frwd_lock);
2540                 mutex_unlock(&session->eh_mutex);
2541                 return FAILED;
2542         }
2543
2544         conn = session->leadconn;
2545         iscsi_get_conn(conn->cls_conn);
2546
2547         spin_unlock_bh(&session->frwd_lock);
2548         mutex_unlock(&session->eh_mutex);
2549
2550         iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2551         iscsi_put_conn(conn->cls_conn);
2552
2553         ISCSI_DBG_EH(session, "wait for relogin\n");
2554         wait_event_interruptible(session->ehwait,
2555                                  session->state == ISCSI_STATE_TERMINATE ||
2556                                  session->state == ISCSI_STATE_LOGGED_IN ||
2557                                  session->state == ISCSI_STATE_RECOVERY_FAILED);
2558         if (signal_pending(current))
2559                 flush_signals(current);
2560
2561         mutex_lock(&session->eh_mutex);
2562         spin_lock_bh(&session->frwd_lock);
2563         if (session->state == ISCSI_STATE_LOGGED_IN) {
2564                 ISCSI_DBG_EH(session,
2565                              "session reset succeeded for %s,%s\n",
2566                              session->targetname, conn->persistent_address);
2567         } else
2568                 goto failed;
2569         spin_unlock_bh(&session->frwd_lock);
2570         mutex_unlock(&session->eh_mutex);
2571         return SUCCESS;
2572 }
2573 EXPORT_SYMBOL_GPL(iscsi_eh_session_reset);
2574
2575 static void iscsi_prep_tgt_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
2576 {
2577         memset(hdr, 0, sizeof(*hdr));
2578         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2579         hdr->flags = ISCSI_TM_FUNC_TARGET_WARM_RESET & ISCSI_FLAG_TM_FUNC_MASK;
2580         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2581         hdr->rtt = RESERVED_ITT;
2582 }
2583
2584 /**
2585  * iscsi_eh_target_reset - reset target
2586  * @sc: scsi command
2587  *
2588  * This will attempt to send a warm target reset.
2589  */
2590 static int iscsi_eh_target_reset(struct scsi_cmnd *sc)
2591 {
2592         struct iscsi_cls_session *cls_session;
2593         struct iscsi_session *session;
2594         struct iscsi_conn *conn;
2595         struct iscsi_tm *hdr;
2596         int rc = FAILED;
2597
2598         cls_session = starget_to_session(scsi_target(sc->device));
2599         session = cls_session->dd_data;
2600
2601         ISCSI_DBG_EH(session, "tgt Reset [sc %p tgt %s]\n", sc,
2602                      session->targetname);
2603
2604         mutex_lock(&session->eh_mutex);
2605         spin_lock_bh(&session->frwd_lock);
2606         /*
2607          * Just check if we are not logged in. We cannot check for
2608          * the phase because the reset could come from a ioctl.
2609          */
2610         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
2611                 goto unlock;
2612         conn = session->leadconn;
2613
2614         /* only have one tmf outstanding at a time */
2615         if (session->tmf_state != TMF_INITIAL)
2616                 goto unlock;
2617         session->tmf_state = TMF_QUEUED;
2618
2619         hdr = &session->tmhdr;
2620         iscsi_prep_tgt_reset_pdu(sc, hdr);
2621
2622         if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
2623                                     session->tgt_reset_timeout)) {
2624                 rc = FAILED;
2625                 goto unlock;
2626         }
2627
2628         switch (session->tmf_state) {
2629         case TMF_SUCCESS:
2630                 break;
2631         case TMF_TIMEDOUT:
2632                 spin_unlock_bh(&session->frwd_lock);
2633                 iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2634                 goto done;
2635         default:
2636                 session->tmf_state = TMF_INITIAL;
2637                 goto unlock;
2638         }
2639
2640         rc = SUCCESS;
2641         spin_unlock_bh(&session->frwd_lock);
2642
2643         iscsi_suspend_tx(conn);
2644
2645         spin_lock_bh(&session->frwd_lock);
2646         memset(hdr, 0, sizeof(*hdr));
2647         fail_scsi_tasks(conn, -1, DID_ERROR);
2648         session->tmf_state = TMF_INITIAL;
2649         spin_unlock_bh(&session->frwd_lock);
2650
2651         iscsi_start_tx(conn);
2652         goto done;
2653
2654 unlock:
2655         spin_unlock_bh(&session->frwd_lock);
2656 done:
2657         ISCSI_DBG_EH(session, "tgt %s reset result = %s\n", session->targetname,
2658                      rc == SUCCESS ? "SUCCESS" : "FAILED");
2659         mutex_unlock(&session->eh_mutex);
2660         return rc;
2661 }
2662
2663 /**
2664  * iscsi_eh_recover_target - reset target and possibly the session
2665  * @sc: scsi command
2666  *
2667  * This will attempt to send a warm target reset. If that fails,
2668  * we will escalate to ERL0 session recovery.
2669  */
2670 int iscsi_eh_recover_target(struct scsi_cmnd *sc)
2671 {
2672         int rc;
2673
2674         rc = iscsi_eh_target_reset(sc);
2675         if (rc == FAILED)
2676                 rc = iscsi_eh_session_reset(sc);
2677         return rc;
2678 }
2679 EXPORT_SYMBOL_GPL(iscsi_eh_recover_target);
2680
2681 /*
2682  * Pre-allocate a pool of @max items of @item_size. By default, the pool
2683  * should be accessed via kfifo_{get,put} on q->queue.
2684  * Optionally, the caller can obtain the array of object pointers
2685  * by passing in a non-NULL @items pointer
2686  */
2687 int
2688 iscsi_pool_init(struct iscsi_pool *q, int max, void ***items, int item_size)
2689 {
2690         int i, num_arrays = 1;
2691
2692         memset(q, 0, sizeof(*q));
2693
2694         q->max = max;
2695
2696         /* If the user passed an items pointer, he wants a copy of
2697          * the array. */
2698         if (items)
2699                 num_arrays++;
2700         q->pool = kvcalloc(num_arrays * max, sizeof(void *), GFP_KERNEL);
2701         if (q->pool == NULL)
2702                 return -ENOMEM;
2703
2704         kfifo_init(&q->queue, (void*)q->pool, max * sizeof(void*));
2705
2706         for (i = 0; i < max; i++) {
2707                 q->pool[i] = kzalloc(item_size, GFP_KERNEL);
2708                 if (q->pool[i] == NULL) {
2709                         q->max = i;
2710                         goto enomem;
2711                 }
2712                 kfifo_in(&q->queue, (void*)&q->pool[i], sizeof(void*));
2713         }
2714
2715         if (items) {
2716                 *items = q->pool + max;
2717                 memcpy(*items, q->pool, max * sizeof(void *));
2718         }
2719
2720         return 0;
2721
2722 enomem:
2723         iscsi_pool_free(q);
2724         return -ENOMEM;
2725 }
2726 EXPORT_SYMBOL_GPL(iscsi_pool_init);
2727
2728 void iscsi_pool_free(struct iscsi_pool *q)
2729 {
2730         int i;
2731
2732         for (i = 0; i < q->max; i++)
2733                 kfree(q->pool[i]);
2734         kvfree(q->pool);
2735 }
2736 EXPORT_SYMBOL_GPL(iscsi_pool_free);
2737
2738 int iscsi_host_get_max_scsi_cmds(struct Scsi_Host *shost,
2739                                  uint16_t requested_cmds_max)
2740 {
2741         int scsi_cmds, total_cmds = requested_cmds_max;
2742
2743 check:
2744         if (!total_cmds)
2745                 total_cmds = ISCSI_DEF_XMIT_CMDS_MAX;
2746         /*
2747          * The iscsi layer needs some tasks for nop handling and tmfs,
2748          * so the cmds_max must at least be greater than ISCSI_MGMT_CMDS_MAX
2749          * + 1 command for scsi IO.
2750          */
2751         if (total_cmds < ISCSI_TOTAL_CMDS_MIN) {
2752                 printk(KERN_ERR "iscsi: invalid max cmds of %d. Must be a power of two that is at least %d.\n",
2753                        total_cmds, ISCSI_TOTAL_CMDS_MIN);
2754                 return -EINVAL;
2755         }
2756
2757         if (total_cmds > ISCSI_TOTAL_CMDS_MAX) {
2758                 printk(KERN_INFO "iscsi: invalid max cmds of %d. Must be a power of 2 less than or equal to %d. Using %d.\n",
2759                        requested_cmds_max, ISCSI_TOTAL_CMDS_MAX,
2760                        ISCSI_TOTAL_CMDS_MAX);
2761                 total_cmds = ISCSI_TOTAL_CMDS_MAX;
2762         }
2763
2764         if (!is_power_of_2(total_cmds)) {
2765                 total_cmds = rounddown_pow_of_two(total_cmds);
2766                 if (total_cmds < ISCSI_TOTAL_CMDS_MIN) {
2767                         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);
2768                         return -EINVAL;
2769                 }
2770
2771                 printk(KERN_INFO "iscsi: invalid max cmds %d. Must be a power of 2. Rounding max cmds down to %d.\n",
2772                        requested_cmds_max, total_cmds);
2773         }
2774
2775         scsi_cmds = total_cmds - ISCSI_MGMT_CMDS_MAX;
2776         if (shost->can_queue && scsi_cmds > shost->can_queue) {
2777                 total_cmds = shost->can_queue;
2778
2779                 printk(KERN_INFO "iscsi: requested max cmds %u is higher than driver limit. Using driver limit %u\n",
2780                        requested_cmds_max, shost->can_queue);
2781                 goto check;
2782         }
2783
2784         return scsi_cmds;
2785 }
2786 EXPORT_SYMBOL_GPL(iscsi_host_get_max_scsi_cmds);
2787
2788 /**
2789  * iscsi_host_add - add host to system
2790  * @shost: scsi host
2791  * @pdev: parent device
2792  *
2793  * This should be called by partial offload and software iscsi drivers
2794  * to add a host to the system.
2795  */
2796 int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev)
2797 {
2798         if (!shost->can_queue)
2799                 shost->can_queue = ISCSI_DEF_XMIT_CMDS_MAX;
2800
2801         if (!shost->cmd_per_lun)
2802                 shost->cmd_per_lun = ISCSI_DEF_CMD_PER_LUN;
2803
2804         return scsi_add_host(shost, pdev);
2805 }
2806 EXPORT_SYMBOL_GPL(iscsi_host_add);
2807
2808 /**
2809  * iscsi_host_alloc - allocate a host and driver data
2810  * @sht: scsi host template
2811  * @dd_data_size: driver host data size
2812  * @xmit_can_sleep: bool indicating if LLD will queue IO from a work queue
2813  *
2814  * This should be called by partial offload and software iscsi drivers.
2815  * To access the driver specific memory use the iscsi_host_priv() macro.
2816  */
2817 struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
2818                                    int dd_data_size, bool xmit_can_sleep)
2819 {
2820         struct Scsi_Host *shost;
2821         struct iscsi_host *ihost;
2822
2823         shost = scsi_host_alloc(sht, sizeof(struct iscsi_host) + dd_data_size);
2824         if (!shost)
2825                 return NULL;
2826         ihost = shost_priv(shost);
2827
2828         if (xmit_can_sleep) {
2829                 snprintf(ihost->workq_name, sizeof(ihost->workq_name),
2830                         "iscsi_q_%d", shost->host_no);
2831                 ihost->workq = alloc_workqueue("%s",
2832                         WQ_SYSFS | __WQ_LEGACY | WQ_MEM_RECLAIM | WQ_UNBOUND,
2833                         1, ihost->workq_name);
2834                 if (!ihost->workq)
2835                         goto free_host;
2836         }
2837
2838         spin_lock_init(&ihost->lock);
2839         ihost->state = ISCSI_HOST_SETUP;
2840         ihost->num_sessions = 0;
2841         init_waitqueue_head(&ihost->session_removal_wq);
2842         return shost;
2843
2844 free_host:
2845         scsi_host_put(shost);
2846         return NULL;
2847 }
2848 EXPORT_SYMBOL_GPL(iscsi_host_alloc);
2849
2850 static void iscsi_notify_host_removed(struct iscsi_cls_session *cls_session)
2851 {
2852         iscsi_session_failure(cls_session->dd_data, ISCSI_ERR_INVALID_HOST);
2853 }
2854
2855 /**
2856  * iscsi_host_remove - remove host and sessions
2857  * @shost: scsi host
2858  * @is_shutdown: true if called from a driver shutdown callout
2859  *
2860  * If there are any sessions left, this will initiate the removal and wait
2861  * for the completion.
2862  */
2863 void iscsi_host_remove(struct Scsi_Host *shost, bool is_shutdown)
2864 {
2865         struct iscsi_host *ihost = shost_priv(shost);
2866         unsigned long flags;
2867
2868         spin_lock_irqsave(&ihost->lock, flags);
2869         ihost->state = ISCSI_HOST_REMOVED;
2870         spin_unlock_irqrestore(&ihost->lock, flags);
2871
2872         if (!is_shutdown)
2873                 iscsi_host_for_each_session(shost, iscsi_notify_host_removed);
2874         else
2875                 iscsi_host_for_each_session(shost, iscsi_force_destroy_session);
2876
2877         wait_event_interruptible(ihost->session_removal_wq,
2878                                  ihost->num_sessions == 0);
2879         if (signal_pending(current))
2880                 flush_signals(current);
2881
2882         scsi_remove_host(shost);
2883 }
2884 EXPORT_SYMBOL_GPL(iscsi_host_remove);
2885
2886 void iscsi_host_free(struct Scsi_Host *shost)
2887 {
2888         struct iscsi_host *ihost = shost_priv(shost);
2889
2890         if (ihost->workq)
2891                 destroy_workqueue(ihost->workq);
2892
2893         kfree(ihost->netdev);
2894         kfree(ihost->hwaddress);
2895         kfree(ihost->initiatorname);
2896         scsi_host_put(shost);
2897 }
2898 EXPORT_SYMBOL_GPL(iscsi_host_free);
2899
2900 static void iscsi_host_dec_session_cnt(struct Scsi_Host *shost)
2901 {
2902         struct iscsi_host *ihost = shost_priv(shost);
2903         unsigned long flags;
2904
2905         shost = scsi_host_get(shost);
2906         if (!shost) {
2907                 printk(KERN_ERR "Invalid state. Cannot notify host removal "
2908                       "of session teardown event because host already "
2909                       "removed.\n");
2910                 return;
2911         }
2912
2913         spin_lock_irqsave(&ihost->lock, flags);
2914         ihost->num_sessions--;
2915         if (ihost->num_sessions == 0)
2916                 wake_up(&ihost->session_removal_wq);
2917         spin_unlock_irqrestore(&ihost->lock, flags);
2918         scsi_host_put(shost);
2919 }
2920
2921 /**
2922  * iscsi_session_setup - create iscsi cls session and host and session
2923  * @iscsit: iscsi transport template
2924  * @shost: scsi host
2925  * @cmds_max: session can queue
2926  * @dd_size: private driver data size, added to session allocation size
2927  * @cmd_task_size: LLD task private data size
2928  * @initial_cmdsn: initial CmdSN
2929  * @id: target ID to add to this session
2930  *
2931  * This can be used by software iscsi_transports that allocate
2932  * a session per scsi host.
2933  *
2934  * Callers should set cmds_max to the largest total numer (mgmt + scsi) of
2935  * tasks they support. The iscsi layer reserves ISCSI_MGMT_CMDS_MAX tasks
2936  * for nop handling and login/logout requests.
2937  */
2938 struct iscsi_cls_session *
2939 iscsi_session_setup(struct iscsi_transport *iscsit, struct Scsi_Host *shost,
2940                     uint16_t cmds_max, int dd_size, int cmd_task_size,
2941                     uint32_t initial_cmdsn, unsigned int id)
2942 {
2943         struct iscsi_host *ihost = shost_priv(shost);
2944         struct iscsi_session *session;
2945         struct iscsi_cls_session *cls_session;
2946         int cmd_i, scsi_cmds;
2947         unsigned long flags;
2948
2949         spin_lock_irqsave(&ihost->lock, flags);
2950         if (ihost->state == ISCSI_HOST_REMOVED) {
2951                 spin_unlock_irqrestore(&ihost->lock, flags);
2952                 return NULL;
2953         }
2954         ihost->num_sessions++;
2955         spin_unlock_irqrestore(&ihost->lock, flags);
2956
2957         scsi_cmds = iscsi_host_get_max_scsi_cmds(shost, cmds_max);
2958         if (scsi_cmds < 0)
2959                 goto dec_session_count;
2960
2961         cls_session = iscsi_alloc_session(shost, iscsit,
2962                                           sizeof(struct iscsi_session) +
2963                                           dd_size);
2964         if (!cls_session)
2965                 goto dec_session_count;
2966         session = cls_session->dd_data;
2967         session->cls_session = cls_session;
2968         session->host = shost;
2969         session->state = ISCSI_STATE_FREE;
2970         session->fast_abort = 1;
2971         session->tgt_reset_timeout = 30;
2972         session->lu_reset_timeout = 15;
2973         session->abort_timeout = 10;
2974         session->scsi_cmds_max = scsi_cmds;
2975         session->cmds_max = scsi_cmds + ISCSI_MGMT_CMDS_MAX;
2976         session->queued_cmdsn = session->cmdsn = initial_cmdsn;
2977         session->exp_cmdsn = initial_cmdsn + 1;
2978         session->max_cmdsn = initial_cmdsn + 1;
2979         session->max_r2t = 1;
2980         session->tt = iscsit;
2981         session->dd_data = cls_session->dd_data + sizeof(*session);
2982
2983         session->tmf_state = TMF_INITIAL;
2984         timer_setup(&session->tmf_timer, iscsi_tmf_timedout, 0);
2985         mutex_init(&session->eh_mutex);
2986
2987         spin_lock_init(&session->frwd_lock);
2988         spin_lock_init(&session->back_lock);
2989
2990         /* initialize SCSI PDU commands pool */
2991         if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
2992                             (void***)&session->cmds,
2993                             cmd_task_size + sizeof(struct iscsi_task)))
2994                 goto cmdpool_alloc_fail;
2995
2996         /* pre-format cmds pool with ITT */
2997         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
2998                 struct iscsi_task *task = session->cmds[cmd_i];
2999
3000                 if (cmd_task_size)
3001                         task->dd_data = &task[1];
3002                 task->itt = cmd_i;
3003                 task->state = ISCSI_TASK_FREE;
3004                 INIT_LIST_HEAD(&task->running);
3005         }
3006
3007         if (!try_module_get(iscsit->owner))
3008                 goto module_get_fail;
3009
3010         if (iscsi_add_session(cls_session, id))
3011                 goto cls_session_fail;
3012
3013         return cls_session;
3014
3015 cls_session_fail:
3016         module_put(iscsit->owner);
3017 module_get_fail:
3018         iscsi_pool_free(&session->cmdpool);
3019 cmdpool_alloc_fail:
3020         iscsi_free_session(cls_session);
3021 dec_session_count:
3022         iscsi_host_dec_session_cnt(shost);
3023         return NULL;
3024 }
3025 EXPORT_SYMBOL_GPL(iscsi_session_setup);
3026
3027 /**
3028  * iscsi_session_teardown - destroy session, host, and cls_session
3029  * @cls_session: iscsi session
3030  */
3031 void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
3032 {
3033         struct iscsi_session *session = cls_session->dd_data;
3034         struct module *owner = cls_session->transport->owner;
3035         struct Scsi_Host *shost = session->host;
3036
3037         iscsi_remove_session(cls_session);
3038
3039         iscsi_pool_free(&session->cmdpool);
3040         kfree(session->password);
3041         kfree(session->password_in);
3042         kfree(session->username);
3043         kfree(session->username_in);
3044         kfree(session->targetname);
3045         kfree(session->targetalias);
3046         kfree(session->initiatorname);
3047         kfree(session->boot_root);
3048         kfree(session->boot_nic);
3049         kfree(session->boot_target);
3050         kfree(session->ifacename);
3051         kfree(session->portal_type);
3052         kfree(session->discovery_parent_type);
3053
3054         iscsi_free_session(cls_session);
3055
3056         iscsi_host_dec_session_cnt(shost);
3057         module_put(owner);
3058 }
3059 EXPORT_SYMBOL_GPL(iscsi_session_teardown);
3060
3061 /**
3062  * iscsi_conn_setup - create iscsi_cls_conn and iscsi_conn
3063  * @cls_session: iscsi_cls_session
3064  * @dd_size: private driver data size
3065  * @conn_idx: cid
3066  */
3067 struct iscsi_cls_conn *
3068 iscsi_conn_setup(struct iscsi_cls_session *cls_session, int dd_size,
3069                  uint32_t conn_idx)
3070 {
3071         struct iscsi_session *session = cls_session->dd_data;
3072         struct iscsi_conn *conn;
3073         struct iscsi_cls_conn *cls_conn;
3074         char *data;
3075
3076         cls_conn = iscsi_create_conn(cls_session, sizeof(*conn) + dd_size,
3077                                      conn_idx);
3078         if (!cls_conn)
3079                 return NULL;
3080         conn = cls_conn->dd_data;
3081         memset(conn, 0, sizeof(*conn) + dd_size);
3082
3083         conn->dd_data = cls_conn->dd_data + sizeof(*conn);
3084         conn->session = session;
3085         conn->cls_conn = cls_conn;
3086         conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
3087         conn->id = conn_idx;
3088         conn->exp_statsn = 0;
3089
3090         timer_setup(&conn->transport_timer, iscsi_check_transport_timeouts, 0);
3091
3092         INIT_LIST_HEAD(&conn->mgmtqueue);
3093         INIT_LIST_HEAD(&conn->cmdqueue);
3094         INIT_LIST_HEAD(&conn->requeue);
3095         INIT_WORK(&conn->xmitwork, iscsi_xmitworker);
3096
3097         /* allocate login_task used for the login/text sequences */
3098         spin_lock_bh(&session->frwd_lock);
3099         if (!kfifo_out(&session->cmdpool.queue,
3100                          (void*)&conn->login_task,
3101                          sizeof(void*))) {
3102                 spin_unlock_bh(&session->frwd_lock);
3103                 goto login_task_alloc_fail;
3104         }
3105         spin_unlock_bh(&session->frwd_lock);
3106
3107         data = (char *) __get_free_pages(GFP_KERNEL,
3108                                          get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
3109         if (!data)
3110                 goto login_task_data_alloc_fail;
3111         conn->login_task->data = conn->data = data;
3112
3113         init_waitqueue_head(&session->ehwait);
3114
3115         return cls_conn;
3116
3117 login_task_data_alloc_fail:
3118         kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
3119                     sizeof(void*));
3120 login_task_alloc_fail:
3121         iscsi_destroy_conn(cls_conn);
3122         return NULL;
3123 }
3124 EXPORT_SYMBOL_GPL(iscsi_conn_setup);
3125
3126 /**
3127  * iscsi_conn_teardown - teardown iscsi connection
3128  * @cls_conn: iscsi class connection
3129  *
3130  * TODO: we may need to make this into a two step process
3131  * like scsi-mls remove + put host
3132  */
3133 void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
3134 {
3135         struct iscsi_conn *conn = cls_conn->dd_data;
3136         struct iscsi_session *session = conn->session;
3137         char *tmp_persistent_address = conn->persistent_address;
3138         char *tmp_local_ipaddr = conn->local_ipaddr;
3139
3140         del_timer_sync(&conn->transport_timer);
3141
3142         mutex_lock(&session->eh_mutex);
3143         spin_lock_bh(&session->frwd_lock);
3144         conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
3145         if (session->leadconn == conn) {
3146                 /*
3147                  * leading connection? then give up on recovery.
3148                  */
3149                 session->state = ISCSI_STATE_TERMINATE;
3150                 wake_up(&session->ehwait);
3151         }
3152         spin_unlock_bh(&session->frwd_lock);
3153
3154         /* flush queued up work because we free the connection below */
3155         iscsi_suspend_tx(conn);
3156
3157         spin_lock_bh(&session->frwd_lock);
3158         free_pages((unsigned long) conn->data,
3159                    get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
3160         /* regular RX path uses back_lock */
3161         spin_lock_bh(&session->back_lock);
3162         kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
3163                     sizeof(void*));
3164         spin_unlock_bh(&session->back_lock);
3165         if (session->leadconn == conn)
3166                 session->leadconn = NULL;
3167         spin_unlock_bh(&session->frwd_lock);
3168         mutex_unlock(&session->eh_mutex);
3169
3170         iscsi_destroy_conn(cls_conn);
3171         kfree(tmp_persistent_address);
3172         kfree(tmp_local_ipaddr);
3173 }
3174 EXPORT_SYMBOL_GPL(iscsi_conn_teardown);
3175
3176 int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
3177 {
3178         struct iscsi_conn *conn = cls_conn->dd_data;
3179         struct iscsi_session *session = conn->session;
3180
3181         if (!session) {
3182                 iscsi_conn_printk(KERN_ERR, conn,
3183                                   "can't start unbound connection\n");
3184                 return -EPERM;
3185         }
3186
3187         if ((session->imm_data_en || !session->initial_r2t_en) &&
3188              session->first_burst > session->max_burst) {
3189                 iscsi_conn_printk(KERN_INFO, conn, "invalid burst lengths: "
3190                                   "first_burst %d max_burst %d\n",
3191                                   session->first_burst, session->max_burst);
3192                 return -EINVAL;
3193         }
3194
3195         if (conn->ping_timeout && !conn->recv_timeout) {
3196                 iscsi_conn_printk(KERN_ERR, conn, "invalid recv timeout of "
3197                                   "zero. Using 5 seconds\n.");
3198                 conn->recv_timeout = 5;
3199         }
3200
3201         if (conn->recv_timeout && !conn->ping_timeout) {
3202                 iscsi_conn_printk(KERN_ERR, conn, "invalid ping timeout of "
3203                                   "zero. Using 5 seconds.\n");
3204                 conn->ping_timeout = 5;
3205         }
3206
3207         spin_lock_bh(&session->frwd_lock);
3208         conn->c_stage = ISCSI_CONN_STARTED;
3209         session->state = ISCSI_STATE_LOGGED_IN;
3210         session->queued_cmdsn = session->cmdsn;
3211
3212         conn->last_recv = jiffies;
3213         conn->last_ping = jiffies;
3214         if (conn->recv_timeout && conn->ping_timeout)
3215                 mod_timer(&conn->transport_timer,
3216                           jiffies + (conn->recv_timeout * HZ));
3217
3218         switch(conn->stop_stage) {
3219         case STOP_CONN_RECOVER:
3220                 /*
3221                  * unblock eh_abort() if it is blocked. re-try all
3222                  * commands after successful recovery
3223                  */
3224                 conn->stop_stage = 0;
3225                 session->tmf_state = TMF_INITIAL;
3226                 session->age++;
3227                 if (session->age == 16)
3228                         session->age = 0;
3229                 break;
3230         case STOP_CONN_TERM:
3231                 conn->stop_stage = 0;
3232                 break;
3233         default:
3234                 break;
3235         }
3236         spin_unlock_bh(&session->frwd_lock);
3237
3238         iscsi_unblock_session(session->cls_session);
3239         wake_up(&session->ehwait);
3240         return 0;
3241 }
3242 EXPORT_SYMBOL_GPL(iscsi_conn_start);
3243
3244 static void
3245 fail_mgmt_tasks(struct iscsi_session *session, struct iscsi_conn *conn)
3246 {
3247         struct iscsi_task *task;
3248         int i, state;
3249
3250         for (i = 0; i < conn->session->cmds_max; i++) {
3251                 task = conn->session->cmds[i];
3252                 if (task->sc)
3253                         continue;
3254
3255                 if (task->state == ISCSI_TASK_FREE)
3256                         continue;
3257
3258                 ISCSI_DBG_SESSION(conn->session,
3259                                   "failing mgmt itt 0x%x state %d\n",
3260                                   task->itt, task->state);
3261
3262                 spin_lock_bh(&session->back_lock);
3263                 if (cleanup_queued_task(task)) {
3264                         spin_unlock_bh(&session->back_lock);
3265                         continue;
3266                 }
3267
3268                 state = ISCSI_TASK_ABRT_SESS_RECOV;
3269                 if (task->state == ISCSI_TASK_PENDING)
3270                         state = ISCSI_TASK_COMPLETED;
3271                 iscsi_complete_task(task, state);
3272                 spin_unlock_bh(&session->back_lock);
3273         }
3274 }
3275
3276 void iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
3277 {
3278         struct iscsi_conn *conn = cls_conn->dd_data;
3279         struct iscsi_session *session = conn->session;
3280         int old_stop_stage;
3281
3282         mutex_lock(&session->eh_mutex);
3283         spin_lock_bh(&session->frwd_lock);
3284         if (conn->stop_stage == STOP_CONN_TERM) {
3285                 spin_unlock_bh(&session->frwd_lock);
3286                 mutex_unlock(&session->eh_mutex);
3287                 return;
3288         }
3289
3290         /*
3291          * When this is called for the in_login state, we only want to clean
3292          * up the login task and connection. We do not need to block and set
3293          * the recovery state again
3294          */
3295         if (flag == STOP_CONN_TERM)
3296                 session->state = ISCSI_STATE_TERMINATE;
3297         else if (conn->stop_stage != STOP_CONN_RECOVER)
3298                 session->state = ISCSI_STATE_IN_RECOVERY;
3299
3300         old_stop_stage = conn->stop_stage;
3301         conn->stop_stage = flag;
3302         spin_unlock_bh(&session->frwd_lock);
3303
3304         del_timer_sync(&conn->transport_timer);
3305         iscsi_suspend_tx(conn);
3306
3307         spin_lock_bh(&session->frwd_lock);
3308         conn->c_stage = ISCSI_CONN_STOPPED;
3309         spin_unlock_bh(&session->frwd_lock);
3310
3311         /*
3312          * for connection level recovery we should not calculate
3313          * header digest. conn->hdr_size used for optimization
3314          * in hdr_extract() and will be re-negotiated at
3315          * set_param() time.
3316          */
3317         if (flag == STOP_CONN_RECOVER) {
3318                 conn->hdrdgst_en = 0;
3319                 conn->datadgst_en = 0;
3320                 if (session->state == ISCSI_STATE_IN_RECOVERY &&
3321                     old_stop_stage != STOP_CONN_RECOVER) {
3322                         ISCSI_DBG_SESSION(session, "blocking session\n");
3323                         iscsi_block_session(session->cls_session);
3324                 }
3325         }
3326
3327         /*
3328          * flush queues.
3329          */
3330         spin_lock_bh(&session->frwd_lock);
3331         fail_scsi_tasks(conn, -1, DID_TRANSPORT_DISRUPTED);
3332         fail_mgmt_tasks(session, conn);
3333         memset(&session->tmhdr, 0, sizeof(session->tmhdr));
3334         spin_unlock_bh(&session->frwd_lock);
3335         mutex_unlock(&session->eh_mutex);
3336 }
3337 EXPORT_SYMBOL_GPL(iscsi_conn_stop);
3338
3339 int iscsi_conn_bind(struct iscsi_cls_session *cls_session,
3340                     struct iscsi_cls_conn *cls_conn, int is_leading)
3341 {
3342         struct iscsi_session *session = cls_session->dd_data;
3343         struct iscsi_conn *conn = cls_conn->dd_data;
3344
3345         spin_lock_bh(&session->frwd_lock);
3346         if (is_leading)
3347                 session->leadconn = conn;
3348
3349         set_bit(ISCSI_CONN_FLAG_BOUND, &conn->flags);
3350         spin_unlock_bh(&session->frwd_lock);
3351
3352         /*
3353          * The target could have reduced it's window size between logins, so
3354          * we have to reset max/exp cmdsn so we can see the new values.
3355          */
3356         spin_lock_bh(&session->back_lock);
3357         session->max_cmdsn = session->exp_cmdsn = session->cmdsn + 1;
3358         spin_unlock_bh(&session->back_lock);
3359         /*
3360          * Unblock xmitworker(), Login Phase will pass through.
3361          */
3362         clear_bit(ISCSI_CONN_FLAG_SUSPEND_RX, &conn->flags);
3363         clear_bit(ISCSI_CONN_FLAG_SUSPEND_TX, &conn->flags);
3364         return 0;
3365 }
3366 EXPORT_SYMBOL_GPL(iscsi_conn_bind);
3367
3368 int iscsi_switch_str_param(char **param, char *new_val_buf)
3369 {
3370         char *new_val;
3371
3372         if (*param) {
3373                 if (!strcmp(*param, new_val_buf))
3374                         return 0;
3375         }
3376
3377         new_val = kstrdup(new_val_buf, GFP_NOIO);
3378         if (!new_val)
3379                 return -ENOMEM;
3380
3381         kfree(*param);
3382         *param = new_val;
3383         return 0;
3384 }
3385 EXPORT_SYMBOL_GPL(iscsi_switch_str_param);
3386
3387 int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
3388                     enum iscsi_param param, char *buf, int buflen)
3389 {
3390         struct iscsi_conn *conn = cls_conn->dd_data;
3391         struct iscsi_session *session = conn->session;
3392         int val;
3393
3394         switch(param) {
3395         case ISCSI_PARAM_FAST_ABORT:
3396                 sscanf(buf, "%d", &session->fast_abort);
3397                 break;
3398         case ISCSI_PARAM_ABORT_TMO:
3399                 sscanf(buf, "%d", &session->abort_timeout);
3400                 break;
3401         case ISCSI_PARAM_LU_RESET_TMO:
3402                 sscanf(buf, "%d", &session->lu_reset_timeout);
3403                 break;
3404         case ISCSI_PARAM_TGT_RESET_TMO:
3405                 sscanf(buf, "%d", &session->tgt_reset_timeout);
3406                 break;
3407         case ISCSI_PARAM_PING_TMO:
3408                 sscanf(buf, "%d", &conn->ping_timeout);
3409                 break;
3410         case ISCSI_PARAM_RECV_TMO:
3411                 sscanf(buf, "%d", &conn->recv_timeout);
3412                 break;
3413         case ISCSI_PARAM_MAX_RECV_DLENGTH:
3414                 sscanf(buf, "%d", &conn->max_recv_dlength);
3415                 break;
3416         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3417                 sscanf(buf, "%d", &conn->max_xmit_dlength);
3418                 break;
3419         case ISCSI_PARAM_HDRDGST_EN:
3420                 sscanf(buf, "%d", &conn->hdrdgst_en);
3421                 break;
3422         case ISCSI_PARAM_DATADGST_EN:
3423                 sscanf(buf, "%d", &conn->datadgst_en);
3424                 break;
3425         case ISCSI_PARAM_INITIAL_R2T_EN:
3426                 sscanf(buf, "%d", &session->initial_r2t_en);
3427                 break;
3428         case ISCSI_PARAM_MAX_R2T:
3429                 sscanf(buf, "%hu", &session->max_r2t);
3430                 break;
3431         case ISCSI_PARAM_IMM_DATA_EN:
3432                 sscanf(buf, "%d", &session->imm_data_en);
3433                 break;
3434         case ISCSI_PARAM_FIRST_BURST:
3435                 sscanf(buf, "%d", &session->first_burst);
3436                 break;
3437         case ISCSI_PARAM_MAX_BURST:
3438                 sscanf(buf, "%d", &session->max_burst);
3439                 break;
3440         case ISCSI_PARAM_PDU_INORDER_EN:
3441                 sscanf(buf, "%d", &session->pdu_inorder_en);
3442                 break;
3443         case ISCSI_PARAM_DATASEQ_INORDER_EN:
3444                 sscanf(buf, "%d", &session->dataseq_inorder_en);
3445                 break;
3446         case ISCSI_PARAM_ERL:
3447                 sscanf(buf, "%d", &session->erl);
3448                 break;
3449         case ISCSI_PARAM_EXP_STATSN:
3450                 sscanf(buf, "%u", &conn->exp_statsn);
3451                 break;
3452         case ISCSI_PARAM_USERNAME:
3453                 return iscsi_switch_str_param(&session->username, buf);
3454         case ISCSI_PARAM_USERNAME_IN:
3455                 return iscsi_switch_str_param(&session->username_in, buf);
3456         case ISCSI_PARAM_PASSWORD:
3457                 return iscsi_switch_str_param(&session->password, buf);
3458         case ISCSI_PARAM_PASSWORD_IN:
3459                 return iscsi_switch_str_param(&session->password_in, buf);
3460         case ISCSI_PARAM_TARGET_NAME:
3461                 return iscsi_switch_str_param(&session->targetname, buf);
3462         case ISCSI_PARAM_TARGET_ALIAS:
3463                 return iscsi_switch_str_param(&session->targetalias, buf);
3464         case ISCSI_PARAM_TPGT:
3465                 sscanf(buf, "%d", &session->tpgt);
3466                 break;
3467         case ISCSI_PARAM_PERSISTENT_PORT:
3468                 sscanf(buf, "%d", &conn->persistent_port);
3469                 break;
3470         case ISCSI_PARAM_PERSISTENT_ADDRESS:
3471                 return iscsi_switch_str_param(&conn->persistent_address, buf);
3472         case ISCSI_PARAM_IFACE_NAME:
3473                 return iscsi_switch_str_param(&session->ifacename, buf);
3474         case ISCSI_PARAM_INITIATOR_NAME:
3475                 return iscsi_switch_str_param(&session->initiatorname, buf);
3476         case ISCSI_PARAM_BOOT_ROOT:
3477                 return iscsi_switch_str_param(&session->boot_root, buf);
3478         case ISCSI_PARAM_BOOT_NIC:
3479                 return iscsi_switch_str_param(&session->boot_nic, buf);
3480         case ISCSI_PARAM_BOOT_TARGET:
3481                 return iscsi_switch_str_param(&session->boot_target, buf);
3482         case ISCSI_PARAM_PORTAL_TYPE:
3483                 return iscsi_switch_str_param(&session->portal_type, buf);
3484         case ISCSI_PARAM_DISCOVERY_PARENT_TYPE:
3485                 return iscsi_switch_str_param(&session->discovery_parent_type,
3486                                               buf);
3487         case ISCSI_PARAM_DISCOVERY_SESS:
3488                 sscanf(buf, "%d", &val);
3489                 session->discovery_sess = !!val;
3490                 break;
3491         case ISCSI_PARAM_LOCAL_IPADDR:
3492                 return iscsi_switch_str_param(&conn->local_ipaddr, buf);
3493         default:
3494                 return -ENOSYS;
3495         }
3496
3497         return 0;
3498 }
3499 EXPORT_SYMBOL_GPL(iscsi_set_param);
3500
3501 int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
3502                             enum iscsi_param param, char *buf)
3503 {
3504         struct iscsi_session *session = cls_session->dd_data;
3505         int len;
3506
3507         switch(param) {
3508         case ISCSI_PARAM_FAST_ABORT:
3509                 len = sysfs_emit(buf, "%d\n", session->fast_abort);
3510                 break;
3511         case ISCSI_PARAM_ABORT_TMO:
3512                 len = sysfs_emit(buf, "%d\n", session->abort_timeout);
3513                 break;
3514         case ISCSI_PARAM_LU_RESET_TMO:
3515                 len = sysfs_emit(buf, "%d\n", session->lu_reset_timeout);
3516                 break;
3517         case ISCSI_PARAM_TGT_RESET_TMO:
3518                 len = sysfs_emit(buf, "%d\n", session->tgt_reset_timeout);
3519                 break;
3520         case ISCSI_PARAM_INITIAL_R2T_EN:
3521                 len = sysfs_emit(buf, "%d\n", session->initial_r2t_en);
3522                 break;
3523         case ISCSI_PARAM_MAX_R2T:
3524                 len = sysfs_emit(buf, "%hu\n", session->max_r2t);
3525                 break;
3526         case ISCSI_PARAM_IMM_DATA_EN:
3527                 len = sysfs_emit(buf, "%d\n", session->imm_data_en);
3528                 break;
3529         case ISCSI_PARAM_FIRST_BURST:
3530                 len = sysfs_emit(buf, "%u\n", session->first_burst);
3531                 break;
3532         case ISCSI_PARAM_MAX_BURST:
3533                 len = sysfs_emit(buf, "%u\n", session->max_burst);
3534                 break;
3535         case ISCSI_PARAM_PDU_INORDER_EN:
3536                 len = sysfs_emit(buf, "%d\n", session->pdu_inorder_en);
3537                 break;
3538         case ISCSI_PARAM_DATASEQ_INORDER_EN:
3539                 len = sysfs_emit(buf, "%d\n", session->dataseq_inorder_en);
3540                 break;
3541         case ISCSI_PARAM_DEF_TASKMGMT_TMO:
3542                 len = sysfs_emit(buf, "%d\n", session->def_taskmgmt_tmo);
3543                 break;
3544         case ISCSI_PARAM_ERL:
3545                 len = sysfs_emit(buf, "%d\n", session->erl);
3546                 break;
3547         case ISCSI_PARAM_TARGET_NAME:
3548                 len = sysfs_emit(buf, "%s\n", session->targetname);
3549                 break;
3550         case ISCSI_PARAM_TARGET_ALIAS:
3551                 len = sysfs_emit(buf, "%s\n", session->targetalias);
3552                 break;
3553         case ISCSI_PARAM_TPGT:
3554                 len = sysfs_emit(buf, "%d\n", session->tpgt);
3555                 break;
3556         case ISCSI_PARAM_USERNAME:
3557                 len = sysfs_emit(buf, "%s\n", session->username);
3558                 break;
3559         case ISCSI_PARAM_USERNAME_IN:
3560                 len = sysfs_emit(buf, "%s\n", session->username_in);
3561                 break;
3562         case ISCSI_PARAM_PASSWORD:
3563                 len = sysfs_emit(buf, "%s\n", session->password);
3564                 break;
3565         case ISCSI_PARAM_PASSWORD_IN:
3566                 len = sysfs_emit(buf, "%s\n", session->password_in);
3567                 break;
3568         case ISCSI_PARAM_IFACE_NAME:
3569                 len = sysfs_emit(buf, "%s\n", session->ifacename);
3570                 break;
3571         case ISCSI_PARAM_INITIATOR_NAME:
3572                 len = sysfs_emit(buf, "%s\n", session->initiatorname);
3573                 break;
3574         case ISCSI_PARAM_BOOT_ROOT:
3575                 len = sysfs_emit(buf, "%s\n", session->boot_root);
3576                 break;
3577         case ISCSI_PARAM_BOOT_NIC:
3578                 len = sysfs_emit(buf, "%s\n", session->boot_nic);
3579                 break;
3580         case ISCSI_PARAM_BOOT_TARGET:
3581                 len = sysfs_emit(buf, "%s\n", session->boot_target);
3582                 break;
3583         case ISCSI_PARAM_AUTO_SND_TGT_DISABLE:
3584                 len = sysfs_emit(buf, "%u\n", session->auto_snd_tgt_disable);
3585                 break;
3586         case ISCSI_PARAM_DISCOVERY_SESS:
3587                 len = sysfs_emit(buf, "%u\n", session->discovery_sess);
3588                 break;
3589         case ISCSI_PARAM_PORTAL_TYPE:
3590                 len = sysfs_emit(buf, "%s\n", session->portal_type);
3591                 break;
3592         case ISCSI_PARAM_CHAP_AUTH_EN:
3593                 len = sysfs_emit(buf, "%u\n", session->chap_auth_en);
3594                 break;
3595         case ISCSI_PARAM_DISCOVERY_LOGOUT_EN:
3596                 len = sysfs_emit(buf, "%u\n", session->discovery_logout_en);
3597                 break;
3598         case ISCSI_PARAM_BIDI_CHAP_EN:
3599                 len = sysfs_emit(buf, "%u\n", session->bidi_chap_en);
3600                 break;
3601         case ISCSI_PARAM_DISCOVERY_AUTH_OPTIONAL:
3602                 len = sysfs_emit(buf, "%u\n", session->discovery_auth_optional);
3603                 break;
3604         case ISCSI_PARAM_DEF_TIME2WAIT:
3605                 len = sysfs_emit(buf, "%d\n", session->time2wait);
3606                 break;
3607         case ISCSI_PARAM_DEF_TIME2RETAIN:
3608                 len = sysfs_emit(buf, "%d\n", session->time2retain);
3609                 break;
3610         case ISCSI_PARAM_TSID:
3611                 len = sysfs_emit(buf, "%u\n", session->tsid);
3612                 break;
3613         case ISCSI_PARAM_ISID:
3614                 len = sysfs_emit(buf, "%02x%02x%02x%02x%02x%02x\n",
3615                               session->isid[0], session->isid[1],
3616                               session->isid[2], session->isid[3],
3617                               session->isid[4], session->isid[5]);
3618                 break;
3619         case ISCSI_PARAM_DISCOVERY_PARENT_IDX:
3620                 len = sysfs_emit(buf, "%u\n", session->discovery_parent_idx);
3621                 break;
3622         case ISCSI_PARAM_DISCOVERY_PARENT_TYPE:
3623                 if (session->discovery_parent_type)
3624                         len = sysfs_emit(buf, "%s\n",
3625                                       session->discovery_parent_type);
3626                 else
3627                         len = sysfs_emit(buf, "\n");
3628                 break;
3629         default:
3630                 return -ENOSYS;
3631         }
3632
3633         return len;
3634 }
3635 EXPORT_SYMBOL_GPL(iscsi_session_get_param);
3636
3637 int iscsi_conn_get_addr_param(struct sockaddr_storage *addr,
3638                               enum iscsi_param param, char *buf)
3639 {
3640         struct sockaddr_in6 *sin6 = NULL;
3641         struct sockaddr_in *sin = NULL;
3642         int len;
3643
3644         switch (addr->ss_family) {
3645         case AF_INET:
3646                 sin = (struct sockaddr_in *)addr;
3647                 break;
3648         case AF_INET6:
3649                 sin6 = (struct sockaddr_in6 *)addr;
3650                 break;
3651         default:
3652                 return -EINVAL;
3653         }
3654
3655         switch (param) {
3656         case ISCSI_PARAM_CONN_ADDRESS:
3657         case ISCSI_HOST_PARAM_IPADDRESS:
3658                 if (sin)
3659                         len = sysfs_emit(buf, "%pI4\n", &sin->sin_addr.s_addr);
3660                 else
3661                         len = sysfs_emit(buf, "%pI6\n", &sin6->sin6_addr);
3662                 break;
3663         case ISCSI_PARAM_CONN_PORT:
3664         case ISCSI_PARAM_LOCAL_PORT:
3665                 if (sin)
3666                         len = sysfs_emit(buf, "%hu\n", be16_to_cpu(sin->sin_port));
3667                 else
3668                         len = sysfs_emit(buf, "%hu\n",
3669                                       be16_to_cpu(sin6->sin6_port));
3670                 break;
3671         default:
3672                 return -EINVAL;
3673         }
3674
3675         return len;
3676 }
3677 EXPORT_SYMBOL_GPL(iscsi_conn_get_addr_param);
3678
3679 int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
3680                          enum iscsi_param param, char *buf)
3681 {
3682         struct iscsi_conn *conn = cls_conn->dd_data;
3683         int len;
3684
3685         switch(param) {
3686         case ISCSI_PARAM_PING_TMO:
3687                 len = sysfs_emit(buf, "%u\n", conn->ping_timeout);
3688                 break;
3689         case ISCSI_PARAM_RECV_TMO:
3690                 len = sysfs_emit(buf, "%u\n", conn->recv_timeout);
3691                 break;
3692         case ISCSI_PARAM_MAX_RECV_DLENGTH:
3693                 len = sysfs_emit(buf, "%u\n", conn->max_recv_dlength);
3694                 break;
3695         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3696                 len = sysfs_emit(buf, "%u\n", conn->max_xmit_dlength);
3697                 break;
3698         case ISCSI_PARAM_HDRDGST_EN:
3699                 len = sysfs_emit(buf, "%d\n", conn->hdrdgst_en);
3700                 break;
3701         case ISCSI_PARAM_DATADGST_EN:
3702                 len = sysfs_emit(buf, "%d\n", conn->datadgst_en);
3703                 break;
3704         case ISCSI_PARAM_IFMARKER_EN:
3705                 len = sysfs_emit(buf, "%d\n", conn->ifmarker_en);
3706                 break;
3707         case ISCSI_PARAM_OFMARKER_EN:
3708                 len = sysfs_emit(buf, "%d\n", conn->ofmarker_en);
3709                 break;
3710         case ISCSI_PARAM_EXP_STATSN:
3711                 len = sysfs_emit(buf, "%u\n", conn->exp_statsn);
3712                 break;
3713         case ISCSI_PARAM_PERSISTENT_PORT:
3714                 len = sysfs_emit(buf, "%d\n", conn->persistent_port);
3715                 break;
3716         case ISCSI_PARAM_PERSISTENT_ADDRESS:
3717                 len = sysfs_emit(buf, "%s\n", conn->persistent_address);
3718                 break;
3719         case ISCSI_PARAM_STATSN:
3720                 len = sysfs_emit(buf, "%u\n", conn->statsn);
3721                 break;
3722         case ISCSI_PARAM_MAX_SEGMENT_SIZE:
3723                 len = sysfs_emit(buf, "%u\n", conn->max_segment_size);
3724                 break;
3725         case ISCSI_PARAM_KEEPALIVE_TMO:
3726                 len = sysfs_emit(buf, "%u\n", conn->keepalive_tmo);
3727                 break;
3728         case ISCSI_PARAM_LOCAL_PORT:
3729                 len = sysfs_emit(buf, "%u\n", conn->local_port);
3730                 break;
3731         case ISCSI_PARAM_TCP_TIMESTAMP_STAT:
3732                 len = sysfs_emit(buf, "%u\n", conn->tcp_timestamp_stat);
3733                 break;
3734         case ISCSI_PARAM_TCP_NAGLE_DISABLE:
3735                 len = sysfs_emit(buf, "%u\n", conn->tcp_nagle_disable);
3736                 break;
3737         case ISCSI_PARAM_TCP_WSF_DISABLE:
3738                 len = sysfs_emit(buf, "%u\n", conn->tcp_wsf_disable);
3739                 break;
3740         case ISCSI_PARAM_TCP_TIMER_SCALE:
3741                 len = sysfs_emit(buf, "%u\n", conn->tcp_timer_scale);
3742                 break;
3743         case ISCSI_PARAM_TCP_TIMESTAMP_EN:
3744                 len = sysfs_emit(buf, "%u\n", conn->tcp_timestamp_en);
3745                 break;
3746         case ISCSI_PARAM_IP_FRAGMENT_DISABLE:
3747                 len = sysfs_emit(buf, "%u\n", conn->fragment_disable);
3748                 break;
3749         case ISCSI_PARAM_IPV4_TOS:
3750                 len = sysfs_emit(buf, "%u\n", conn->ipv4_tos);
3751                 break;
3752         case ISCSI_PARAM_IPV6_TC:
3753                 len = sysfs_emit(buf, "%u\n", conn->ipv6_traffic_class);
3754                 break;
3755         case ISCSI_PARAM_IPV6_FLOW_LABEL:
3756                 len = sysfs_emit(buf, "%u\n", conn->ipv6_flow_label);
3757                 break;
3758         case ISCSI_PARAM_IS_FW_ASSIGNED_IPV6:
3759                 len = sysfs_emit(buf, "%u\n", conn->is_fw_assigned_ipv6);
3760                 break;
3761         case ISCSI_PARAM_TCP_XMIT_WSF:
3762                 len = sysfs_emit(buf, "%u\n", conn->tcp_xmit_wsf);
3763                 break;
3764         case ISCSI_PARAM_TCP_RECV_WSF:
3765                 len = sysfs_emit(buf, "%u\n", conn->tcp_recv_wsf);
3766                 break;
3767         case ISCSI_PARAM_LOCAL_IPADDR:
3768                 len = sysfs_emit(buf, "%s\n", conn->local_ipaddr);
3769                 break;
3770         default:
3771                 return -ENOSYS;
3772         }
3773
3774         return len;
3775 }
3776 EXPORT_SYMBOL_GPL(iscsi_conn_get_param);
3777
3778 int iscsi_host_get_param(struct Scsi_Host *shost, enum iscsi_host_param param,
3779                          char *buf)
3780 {
3781         struct iscsi_host *ihost = shost_priv(shost);
3782         int len;
3783
3784         switch (param) {
3785         case ISCSI_HOST_PARAM_NETDEV_NAME:
3786                 len = sysfs_emit(buf, "%s\n", ihost->netdev);
3787                 break;
3788         case ISCSI_HOST_PARAM_HWADDRESS:
3789                 len = sysfs_emit(buf, "%s\n", ihost->hwaddress);
3790                 break;
3791         case ISCSI_HOST_PARAM_INITIATOR_NAME:
3792                 len = sysfs_emit(buf, "%s\n", ihost->initiatorname);
3793                 break;
3794         default:
3795                 return -ENOSYS;
3796         }
3797
3798         return len;
3799 }
3800 EXPORT_SYMBOL_GPL(iscsi_host_get_param);
3801
3802 int iscsi_host_set_param(struct Scsi_Host *shost, enum iscsi_host_param param,
3803                          char *buf, int buflen)
3804 {
3805         struct iscsi_host *ihost = shost_priv(shost);
3806
3807         switch (param) {
3808         case ISCSI_HOST_PARAM_NETDEV_NAME:
3809                 return iscsi_switch_str_param(&ihost->netdev, buf);
3810         case ISCSI_HOST_PARAM_HWADDRESS:
3811                 return iscsi_switch_str_param(&ihost->hwaddress, buf);
3812         case ISCSI_HOST_PARAM_INITIATOR_NAME:
3813                 return iscsi_switch_str_param(&ihost->initiatorname, buf);
3814         default:
3815                 return -ENOSYS;
3816         }
3817
3818         return 0;
3819 }
3820 EXPORT_SYMBOL_GPL(iscsi_host_set_param);
3821
3822 MODULE_AUTHOR("Mike Christie");
3823 MODULE_DESCRIPTION("iSCSI library functions");
3824 MODULE_LICENSE("GPL");