drivers/scsi/libiscsi.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * iSCSI lib functions
   4  *
   5  * Copyright (C) 2006 Red Hat, Inc.  All rights reserved.
   6  * Copyright (C) 2004 - 2006 Mike Christie
   7  * Copyright (C) 2004 - 2005 Dmitry Yusupov
   8  * Copyright (C) 2004 - 2005 Alex Aizman
   9  * maintained by open-iscsi@googlegroups.com
  10  */
  11 #include <linux/types.h>
  12 #include <linux/kfifo.h>
  13 #include <linux/delay.h>
  14 #include <linux/log2.h>
  15 #include <linux/slab.h>
  16 #include <linux/sched/signal.h>
  17 #include <linux/module.h>
  18 #include <asm/unaligned.h>
  19 #include <net/tcp.h>
  20 #include <scsi/scsi_cmnd.h>
  21 #include <scsi/scsi_device.h>
  22 #include <scsi/scsi_eh.h>
  23 #include <scsi/scsi_tcq.h>
  24 #include <scsi/scsi_host.h>
  25 #include <scsi/scsi.h>
  26 #include <scsi/iscsi_proto.h>
  27 #include <scsi/scsi_transport.h>
  28 #include <scsi/scsi_transport_iscsi.h>
  29 #include <scsi/libiscsi.h>
  30 #include <trace/events/iscsi.h>
  31
  32 static int iscsi_dbg_lib_conn;
  33 module_param_named(debug_libiscsi_conn, iscsi_dbg_lib_conn, int,
  34                    S_IRUGO | S_IWUSR);
  35 MODULE_PARM_DESC(debug_libiscsi_conn,
  36                  "Turn on debugging for connections in libiscsi module. "
  37                  "Set to 1 to turn on, and zero to turn off. Default is off.");
  38
  39 static int iscsi_dbg_lib_session;
  40 module_param_named(debug_libiscsi_session, iscsi_dbg_lib_session, int,
  41                    S_IRUGO | S_IWUSR);
  42 MODULE_PARM_DESC(debug_libiscsi_session,
  43                  "Turn on debugging for sessions in libiscsi module. "
  44                  "Set to 1 to turn on, and zero to turn off. Default is off.");
  45
  46 static int iscsi_dbg_lib_eh;
  47 module_param_named(debug_libiscsi_eh, iscsi_dbg_lib_eh, int,
  48                    S_IRUGO | S_IWUSR);
  49 MODULE_PARM_DESC(debug_libiscsi_eh,
  50                  "Turn on debugging for error handling in libiscsi module. "
  51                  "Set to 1 to turn on, and zero to turn off. Default is off.");
  52
  53 #define ISCSI_DBG_CONN(_conn, dbg_fmt, arg...)                  \
  54         do {                                                    \
  55                 if (iscsi_dbg_lib_conn)                         \
  56                         iscsi_conn_printk(KERN_INFO, _conn,     \
  57                                              "%s " dbg_fmt,     \
  58                                              __func__, ##arg);  \
  59                 iscsi_dbg_trace(trace_iscsi_dbg_conn,           \
  60                                 &(_conn)->cls_conn->dev,        \
  61                                 "%s " dbg_fmt, __func__, ##arg);\
  62         } while (0);
  63
  64 #define ISCSI_DBG_SESSION(_session, dbg_fmt, arg...)                    \
  65         do {                                                            \
  66                 if (iscsi_dbg_lib_session)                              \
  67                         iscsi_session_printk(KERN_INFO, _session,       \
  68                                              "%s " dbg_fmt,             \
  69                                              __func__, ##arg);          \
  70                 iscsi_dbg_trace(trace_iscsi_dbg_session,                \
  71                                 &(_session)->cls_session->dev,          \
  72                                 "%s " dbg_fmt, __func__, ##arg);        \
  73         } while (0);
  74
  75 #define ISCSI_DBG_EH(_session, dbg_fmt, arg...)                         \
  76         do {                                                            \
  77                 if (iscsi_dbg_lib_eh)                                   \
  78                         iscsi_session_printk(KERN_INFO, _session,       \
  79                                              "%s " dbg_fmt,             \
  80                                              __func__, ##arg);          \
  81                 iscsi_dbg_trace(trace_iscsi_dbg_eh,                     \
  82                                 &(_session)->cls_session->dev,          \
  83                                 "%s " dbg_fmt, __func__, ##arg);        \
  84         } while (0);
  85
  86 inline void iscsi_conn_queue_work(struct iscsi_conn *conn)
  87 {
  88         struct Scsi_Host *shost = conn->session->host;
  89         struct iscsi_host *ihost = shost_priv(shost);
  90
  91         if (ihost->workq)
  92                 queue_work(ihost->workq, &conn->xmitwork);
  93 }
  94 EXPORT_SYMBOL_GPL(iscsi_conn_queue_work);
  95
  96 static void __iscsi_update_cmdsn(struct iscsi_session *session,
  97                                  uint32_t exp_cmdsn, uint32_t max_cmdsn)
  98 {
  99         /*
 100          * standard specifies this check for when to update expected and
 101          * max sequence numbers
 102          */
 103         if (iscsi_sna_lt(max_cmdsn, exp_cmdsn - 1))
 104                 return;
 105
 106         if (exp_cmdsn != session->exp_cmdsn &&
 107             !iscsi_sna_lt(exp_cmdsn, session->exp_cmdsn))
 108                 session->exp_cmdsn = exp_cmdsn;
 109
 110         if (max_cmdsn != session->max_cmdsn &&
 111             !iscsi_sna_lt(max_cmdsn, session->max_cmdsn))
 112                 session->max_cmdsn = max_cmdsn;
 113 }
 114
 115 void iscsi_update_cmdsn(struct iscsi_session *session, struct iscsi_nopin *hdr)
 116 {
 117         __iscsi_update_cmdsn(session, be32_to_cpu(hdr->exp_cmdsn),
 118                              be32_to_cpu(hdr->max_cmdsn));
 119 }
 120 EXPORT_SYMBOL_GPL(iscsi_update_cmdsn);
 121
 122 /**
 123  * iscsi_prep_data_out_pdu - initialize Data-Out
 124  * @task: scsi command task
 125  * @r2t: R2T info
 126  * @hdr: iscsi data in pdu
 127  *
 128  * Notes:
 129  *      Initialize Data-Out within this R2T sequence and finds
 130  *      proper data_offset within this SCSI command.
 131  *
 132  *      This function is called with connection lock taken.
 133  **/
 134 void iscsi_prep_data_out_pdu(struct iscsi_task *task, struct iscsi_r2t_info *r2t,
 135                            struct iscsi_data *hdr)
 136 {
 137         struct iscsi_conn *conn = task->conn;
 138         unsigned int left = r2t->data_length - r2t->sent;
 139
 140         task->hdr_len = sizeof(struct iscsi_data);
 141
 142         memset(hdr, 0, sizeof(struct iscsi_data));
 143         hdr->ttt = r2t->ttt;
 144         hdr->datasn = cpu_to_be32(r2t->datasn);
 145         r2t->datasn++;
 146         hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
 147         hdr->lun = task->lun;
 148         hdr->itt = task->hdr_itt;
 149         hdr->exp_statsn = r2t->exp_statsn;
 150         hdr->offset = cpu_to_be32(r2t->data_offset + r2t->sent);
 151         if (left > conn->max_xmit_dlength) {
 152                 hton24(hdr->dlength, conn->max_xmit_dlength);
 153                 r2t->data_count = conn->max_xmit_dlength;
 154                 hdr->flags = 0;
 155         } else {
 156                 hton24(hdr->dlength, left);
 157                 r2t->data_count = left;
 158                 hdr->flags = ISCSI_FLAG_CMD_FINAL;
 159         }
 160         conn->dataout_pdus_cnt++;
 161 }
 162 EXPORT_SYMBOL_GPL(iscsi_prep_data_out_pdu);
 163
 164 static int iscsi_add_hdr(struct iscsi_task *task, unsigned len)
 165 {
 166         unsigned exp_len = task->hdr_len + len;
 167
 168         if (exp_len > task->hdr_max) {
 169                 WARN_ON(1);
 170                 return -EINVAL;
 171         }
 172
 173         WARN_ON(len & (ISCSI_PAD_LEN - 1)); /* caller must pad the AHS */
 174         task->hdr_len = exp_len;
 175         return 0;
 176 }
 177
 178 /*
 179  * make an extended cdb AHS
 180  */
 181 static int iscsi_prep_ecdb_ahs(struct iscsi_task *task)
 182 {
 183         struct scsi_cmnd *cmd = task->sc;
 184         unsigned rlen, pad_len;
 185         unsigned short ahslength;
 186         struct iscsi_ecdb_ahdr *ecdb_ahdr;
 187         int rc;
 188
 189         ecdb_ahdr = iscsi_next_hdr(task);
 190         rlen = cmd->cmd_len - ISCSI_CDB_SIZE;
 191
 192         BUG_ON(rlen > sizeof(ecdb_ahdr->ecdb));
 193         ahslength = rlen + sizeof(ecdb_ahdr->reserved);
 194
 195         pad_len = iscsi_padding(rlen);
 196
 197         rc = iscsi_add_hdr(task, sizeof(ecdb_ahdr->ahslength) +
 198                            sizeof(ecdb_ahdr->ahstype) + ahslength + pad_len);
 199         if (rc)
 200                 return rc;
 201
 202         if (pad_len)
 203                 memset(&ecdb_ahdr->ecdb[rlen], 0, pad_len);
 204
 205         ecdb_ahdr->ahslength = cpu_to_be16(ahslength);
 206         ecdb_ahdr->ahstype = ISCSI_AHSTYPE_CDB;
 207         ecdb_ahdr->reserved = 0;
 208         memcpy(ecdb_ahdr->ecdb, cmd->cmnd + ISCSI_CDB_SIZE, rlen);
 209
 210         ISCSI_DBG_SESSION(task->conn->session,
 211                           "iscsi_prep_ecdb_ahs: varlen_cdb_len %d "
 212                           "rlen %d pad_len %d ahs_length %d iscsi_headers_size "
 213                           "%u\n", cmd->cmd_len, rlen, pad_len, ahslength,
 214                           task->hdr_len);
 215         return 0;
 216 }
 217
 218 /**
 219  * iscsi_check_tmf_restrictions - check if a task is affected by TMF
 220  * @task: iscsi task
 221  * @opcode: opcode to check for
 222  *
 223  * During TMF a task has to be checked if it's affected.
 224  * All unrelated I/O can be passed through, but I/O to the
 225  * affected LUN should be restricted.
 226  * If 'fast_abort' is set we won't be sending any I/O to the
 227  * affected LUN.
 228  * Otherwise the target is waiting for all TTTs to be completed,
 229  * so we have to send all outstanding Data-Out PDUs to the target.
 230  */
 231 static int iscsi_check_tmf_restrictions(struct iscsi_task *task, int opcode)
 232 {
 233         struct iscsi_session *session = task->conn->session;
 234         struct iscsi_tm *tmf = &session->tmhdr;
 235         u64 hdr_lun;
 236
 237         if (session->tmf_state == TMF_INITIAL)
 238                 return 0;
 239
 240         if ((tmf->opcode & ISCSI_OPCODE_MASK) != ISCSI_OP_SCSI_TMFUNC)
 241                 return 0;
 242
 243         switch (ISCSI_TM_FUNC_VALUE(tmf)) {
 244         case ISCSI_TM_FUNC_LOGICAL_UNIT_RESET:
 245                 /*
 246                  * Allow PDUs for unrelated LUNs
 247                  */
 248                 hdr_lun = scsilun_to_int(&tmf->lun);
 249                 if (hdr_lun != task->sc->device->lun)
 250                         return 0;
 251                 fallthrough;
 252         case ISCSI_TM_FUNC_TARGET_WARM_RESET:
 253                 /*
 254                  * Fail all SCSI cmd PDUs
 255                  */
 256                 if (opcode != ISCSI_OP_SCSI_DATA_OUT) {
 257                         iscsi_session_printk(KERN_INFO, session,
 258                                              "task [op %x itt 0x%x/0x%x] rejected.\n",
 259                                              opcode, task->itt, task->hdr_itt);
 260                         return -EACCES;
 261                 }
 262                 /*
 263                  * And also all data-out PDUs in response to R2T
 264                  * if fast_abort is set.
 265                  */
 266                 if (session->fast_abort) {
 267                         iscsi_session_printk(KERN_INFO, session,
 268                                              "task [op %x itt 0x%x/0x%x] fast abort.\n",
 269                                              opcode, task->itt, task->hdr_itt);
 270                         return -EACCES;
 271                 }
 272                 break;
 273         case ISCSI_TM_FUNC_ABORT_TASK:
 274                 /*
 275                  * the caller has already checked if the task
 276                  * they want to abort was in the pending queue so if
 277                  * we are here the cmd pdu has gone out already, and
 278                  * we will only hit this for data-outs
 279                  */
 280                 if (opcode == ISCSI_OP_SCSI_DATA_OUT &&
 281                     task->hdr_itt == tmf->rtt) {
 282                         ISCSI_DBG_SESSION(session,
 283                                           "Preventing task %x/%x from sending "
 284                                           "data-out due to abort task in "
 285                                           "progress\n", task->itt,
 286                                           task->hdr_itt);
 287                         return -EACCES;
 288                 }
 289                 break;
 290         }
 291
 292         return 0;
 293 }
 294
 295 /**
 296  * iscsi_prep_scsi_cmd_pdu - prep iscsi scsi cmd pdu
 297  * @task: iscsi task
 298  *
 299  * Prep basic iSCSI PDU fields for a scsi cmd pdu. The LLD should set
 300  * fields like dlength or final based on how much data it sends
 301  */
 302 static int iscsi_prep_scsi_cmd_pdu(struct iscsi_task *task)
 303 {
 304         struct iscsi_conn *conn = task->conn;
 305         struct iscsi_session *session = conn->session;
 306         struct scsi_cmnd *sc = task->sc;
 307         struct iscsi_scsi_req *hdr;
 308         unsigned hdrlength, cmd_len, transfer_length;
 309         itt_t itt;
 310         int rc;
 311
 312         rc = iscsi_check_tmf_restrictions(task, ISCSI_OP_SCSI_CMD);
 313         if (rc)
 314                 return rc;
 315
 316         if (conn->session->tt->alloc_pdu) {
 317                 rc = conn->session->tt->alloc_pdu(task, ISCSI_OP_SCSI_CMD);
 318                 if (rc)
 319                         return rc;
 320         }
 321         hdr = (struct iscsi_scsi_req *)task->hdr;
 322         itt = hdr->itt;
 323         memset(hdr, 0, sizeof(*hdr));
 324
 325         if (session->tt->parse_pdu_itt)
 326                 hdr->itt = task->hdr_itt = itt;
 327         else
 328                 hdr->itt = task->hdr_itt = build_itt(task->itt,
 329                                                      task->conn->session->age);
 330         task->hdr_len = 0;
 331         rc = iscsi_add_hdr(task, sizeof(*hdr));
 332         if (rc)
 333                 return rc;
 334         hdr->opcode = ISCSI_OP_SCSI_CMD;
 335         hdr->flags = ISCSI_ATTR_SIMPLE;
 336         int_to_scsilun(sc->device->lun, &hdr->lun);
 337         task->lun = hdr->lun;
 338         hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
 339         cmd_len = sc->cmd_len;
 340         if (cmd_len < ISCSI_CDB_SIZE)
 341                 memset(&hdr->cdb[cmd_len], 0, ISCSI_CDB_SIZE - cmd_len);
 342         else if (cmd_len > ISCSI_CDB_SIZE) {
 343                 rc = iscsi_prep_ecdb_ahs(task);
 344                 if (rc)
 345                         return rc;
 346                 cmd_len = ISCSI_CDB_SIZE;
 347         }
 348         memcpy(hdr->cdb, sc->cmnd, cmd_len);
 349
 350         task->imm_count = 0;
 351         if (scsi_get_prot_op(sc) != SCSI_PROT_NORMAL)
 352                 task->protected = true;
 353
 354         transfer_length = scsi_transfer_length(sc);
 355         hdr->data_length = cpu_to_be32(transfer_length);
 356         if (sc->sc_data_direction == DMA_TO_DEVICE) {
 357                 struct iscsi_r2t_info *r2t = &task->unsol_r2t;
 358
 359                 hdr->flags |= ISCSI_FLAG_CMD_WRITE;
 360                 /*
 361                  * Write counters:
 362                  *
 363                  *      imm_count       bytes to be sent right after
 364                  *                      SCSI PDU Header
 365                  *
 366                  *      unsol_count     bytes(as Data-Out) to be sent
 367                  *                      without R2T ack right after
 368                  *                      immediate data
 369                  *
 370                  *      r2t data_length bytes to be sent via R2T ack's
 371                  *
 372                  *      pad_count       bytes to be sent as zero-padding
 373                  */
 374                 memset(r2t, 0, sizeof(*r2t));
 375
 376                 if (session->imm_data_en) {
 377                         if (transfer_length >= session->first_burst)
 378                                 task->imm_count = min(session->first_burst,
 379                                                         conn->max_xmit_dlength);
 380                         else
 381                                 task->imm_count = min(transfer_length,
 382                                                       conn->max_xmit_dlength);
 383                         hton24(hdr->dlength, task->imm_count);
 384                 } else
 385                         zero_data(hdr->dlength);
 386
 387                 if (!session->initial_r2t_en) {
 388                         r2t->data_length = min(session->first_burst,
 389                                                transfer_length) -
 390                                                task->imm_count;
 391                         r2t->data_offset = task->imm_count;
 392                         r2t->ttt = cpu_to_be32(ISCSI_RESERVED_TAG);
 393                         r2t->exp_statsn = cpu_to_be32(conn->exp_statsn);
 394                 }
 395
 396                 if (!task->unsol_r2t.data_length)
 397                         /* No unsolicit Data-Out's */
 398                         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
 399         } else {
 400                 hdr->flags |= ISCSI_FLAG_CMD_FINAL;
 401                 zero_data(hdr->dlength);
 402
 403                 if (sc->sc_data_direction == DMA_FROM_DEVICE)
 404                         hdr->flags |= ISCSI_FLAG_CMD_READ;
 405         }
 406
 407         /* calculate size of additional header segments (AHSs) */
 408         hdrlength = task->hdr_len - sizeof(*hdr);
 409
 410         WARN_ON(hdrlength & (ISCSI_PAD_LEN-1));
 411         hdrlength /= ISCSI_PAD_LEN;
 412
 413         WARN_ON(hdrlength >= 256);
 414         hdr->hlength = hdrlength & 0xFF;
 415         hdr->cmdsn = task->cmdsn = cpu_to_be32(session->cmdsn);
 416
 417         if (session->tt->init_task && session->tt->init_task(task))
 418                 return -EIO;
 419
 420         task->state = ISCSI_TASK_RUNNING;
 421         session->cmdsn++;
 422
 423         conn->scsicmd_pdus_cnt++;
 424         ISCSI_DBG_SESSION(session, "iscsi prep [%s cid %d sc %p cdb 0x%x "
 425                           "itt 0x%x len %d cmdsn %d win %d]\n",
 426                           sc->sc_data_direction == DMA_TO_DEVICE ?
 427                           "write" : "read", conn->id, sc, sc->cmnd[0],
 428                           task->itt, transfer_length,
 429                           session->cmdsn,
 430                           session->max_cmdsn - session->exp_cmdsn + 1);
 431         return 0;
 432 }
 433
 434 /**
 435  * iscsi_free_task - free a task
 436  * @task: iscsi cmd task
 437  *
 438  * Must be called with session back_lock.
 439  * This function returns the scsi command to scsi-ml or cleans
 440  * up mgmt tasks then returns the task to the pool.
 441  */
 442 static void iscsi_free_task(struct iscsi_task *task)
 443 {
 444         struct iscsi_conn *conn = task->conn;
 445         struct iscsi_session *session = conn->session;
 446         struct scsi_cmnd *sc = task->sc;
 447         int oldstate = task->state;
 448
 449         ISCSI_DBG_SESSION(session, "freeing task itt 0x%x state %d sc %p\n",
 450                           task->itt, task->state, task->sc);
 451
 452         session->tt->cleanup_task(task);
 453         task->state = ISCSI_TASK_FREE;
 454         task->sc = NULL;
 455         /*
 456          * login task is preallocated so do not free
 457          */
 458         if (conn->login_task == task)
 459                 return;
 460
 461         kfifo_in(&session->cmdpool.queue, (void*)&task, sizeof(void*));
 462
 463         if (sc) {
 464                 /* SCSI eh reuses commands to verify us */
 465                 sc->SCp.ptr = NULL;
 466                 /*
 467                  * queue command may call this to free the task, so
 468                  * it will decide how to return sc to scsi-ml.
 469                  */
 470                 if (oldstate != ISCSI_TASK_REQUEUE_SCSIQ)
 471                         sc->scsi_done(sc);
 472         }
 473 }
 474
 475 void __iscsi_get_task(struct iscsi_task *task)
 476 {
 477         refcount_inc(&task->refcount);
 478 }
 479 EXPORT_SYMBOL_GPL(__iscsi_get_task);
 480
 481 void __iscsi_put_task(struct iscsi_task *task)
 482 {
 483         if (refcount_dec_and_test(&task->refcount))
 484                 iscsi_free_task(task);
 485 }
 486 EXPORT_SYMBOL_GPL(__iscsi_put_task);
 487
 488 void iscsi_put_task(struct iscsi_task *task)
 489 {
 490         struct iscsi_session *session = task->conn->session;
 491
 492         /* regular RX path uses back_lock */
 493         spin_lock_bh(&session->back_lock);
 494         __iscsi_put_task(task);
 495         spin_unlock_bh(&session->back_lock);
 496 }
 497 EXPORT_SYMBOL_GPL(iscsi_put_task);
 498
 499 /**
 500  * iscsi_complete_task - finish a task
 501  * @task: iscsi cmd task
 502  * @state: state to complete task with
 503  *
 504  * Must be called with session back_lock.
 505  */
 506 static void iscsi_complete_task(struct iscsi_task *task, int state)
 507 {
 508         struct iscsi_conn *conn = task->conn;
 509
 510         ISCSI_DBG_SESSION(conn->session,
 511                           "complete task itt 0x%x state %d sc %p\n",
 512                           task->itt, task->state, task->sc);
 513         if (task->state == ISCSI_TASK_COMPLETED ||
 514             task->state == ISCSI_TASK_ABRT_TMF ||
 515             task->state == ISCSI_TASK_ABRT_SESS_RECOV ||
 516             task->state == ISCSI_TASK_REQUEUE_SCSIQ)
 517                 return;
 518         WARN_ON_ONCE(task->state == ISCSI_TASK_FREE);
 519         task->state = state;
 520
 521         if (READ_ONCE(conn->ping_task) == task)
 522                 WRITE_ONCE(conn->ping_task, NULL);
 523
 524         /* release get from queueing */
 525         __iscsi_put_task(task);
 526 }
 527
 528 /**
 529  * iscsi_complete_scsi_task - finish scsi task normally
 530  * @task: iscsi task for scsi cmd
 531  * @exp_cmdsn: expected cmd sn in cpu format
 532  * @max_cmdsn: max cmd sn in cpu format
 533  *
 534  * This is used when drivers do not need or cannot perform
 535  * lower level pdu processing.
 536  *
 537  * Called with session back_lock
 538  */
 539 void iscsi_complete_scsi_task(struct iscsi_task *task,
 540                               uint32_t exp_cmdsn, uint32_t max_cmdsn)
 541 {
 542         struct iscsi_conn *conn = task->conn;
 543
 544         ISCSI_DBG_SESSION(conn->session, "[itt 0x%x]\n", task->itt);
 545
 546         conn->last_recv = jiffies;
 547         __iscsi_update_cmdsn(conn->session, exp_cmdsn, max_cmdsn);
 548         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 549 }
 550 EXPORT_SYMBOL_GPL(iscsi_complete_scsi_task);
 551
 552 /*
 553  * Must be called with back and frwd lock
 554  */
 555 static bool cleanup_queued_task(struct iscsi_task *task)
 556 {
 557         struct iscsi_conn *conn = task->conn;
 558         bool early_complete = false;
 559
 560         /* Bad target might have completed task while it was still running */
 561         if (task->state == ISCSI_TASK_COMPLETED)
 562                 early_complete = true;
 563
 564         if (!list_empty(&task->running)) {
 565                 list_del_init(&task->running);
 566                 /*
 567                  * If it's on a list but still running, this could be from
 568                  * a bad target sending a rsp early, cleanup from a TMF, or
 569                  * session recovery.
 570                  */
 571                 if (task->state == ISCSI_TASK_RUNNING ||
 572                     task->state == ISCSI_TASK_COMPLETED)
 573                         __iscsi_put_task(task);
 574         }
 575
 576         if (conn->session->running_aborted_task == task) {
 577                 conn->session->running_aborted_task = NULL;
 578                 __iscsi_put_task(task);
 579         }
 580
 581         if (conn->task == task) {
 582                 conn->task = NULL;
 583                 __iscsi_put_task(task);
 584         }
 585
 586         return early_complete;
 587 }
 588
 589 /*
 590  * session frwd lock must be held and if not called for a task that is still
 591  * pending or from the xmit thread, then xmit thread must be suspended
 592  */
 593 static void fail_scsi_task(struct iscsi_task *task, int err)
 594 {
 595         struct iscsi_conn *conn = task->conn;
 596         struct scsi_cmnd *sc;
 597         int state;
 598
 599         spin_lock_bh(&conn->session->back_lock);
 600         if (cleanup_queued_task(task)) {
 601                 spin_unlock_bh(&conn->session->back_lock);
 602                 return;
 603         }
 604
 605         if (task->state == ISCSI_TASK_PENDING) {
 606                 /*
 607                  * cmd never made it to the xmit thread, so we should not count
 608                  * the cmd in the sequencing
 609                  */
 610                 conn->session->queued_cmdsn--;
 611                 /* it was never sent so just complete like normal */
 612                 state = ISCSI_TASK_COMPLETED;
 613         } else if (err == DID_TRANSPORT_DISRUPTED)
 614                 state = ISCSI_TASK_ABRT_SESS_RECOV;
 615         else
 616                 state = ISCSI_TASK_ABRT_TMF;
 617
 618         sc = task->sc;
 619         sc->result = err << 16;
 620         scsi_set_resid(sc, scsi_bufflen(sc));
 621         iscsi_complete_task(task, state);
 622         spin_unlock_bh(&conn->session->back_lock);
 623 }
 624
 625 static int iscsi_prep_mgmt_task(struct iscsi_conn *conn,
 626                                 struct iscsi_task *task)
 627 {
 628         struct iscsi_session *session = conn->session;
 629         struct iscsi_hdr *hdr = task->hdr;
 630         struct iscsi_nopout *nop = (struct iscsi_nopout *)hdr;
 631         uint8_t opcode = hdr->opcode & ISCSI_OPCODE_MASK;
 632
 633         if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
 634                 return -ENOTCONN;
 635
 636         if (opcode != ISCSI_OP_LOGIN && opcode != ISCSI_OP_TEXT)
 637                 nop->exp_statsn = cpu_to_be32(conn->exp_statsn);
 638         /*
 639          * pre-format CmdSN for outgoing PDU.
 640          */
 641         nop->cmdsn = cpu_to_be32(session->cmdsn);
 642         if (hdr->itt != RESERVED_ITT) {
 643                 /*
 644                  * TODO: We always use immediate for normal session pdus.
 645                  * If we start to send tmfs or nops as non-immediate then
 646                  * we should start checking the cmdsn numbers for mgmt tasks.
 647                  *
 648                  * During discovery sessions iscsid sends TEXT as non immediate,
 649                  * but we always only send one PDU at a time.
 650                  */
 651                 if (conn->c_stage == ISCSI_CONN_STARTED &&
 652                     !(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
 653                         session->queued_cmdsn++;
 654                         session->cmdsn++;
 655                 }
 656         }
 657
 658         if (session->tt->init_task && session->tt->init_task(task))
 659                 return -EIO;
 660
 661         if ((hdr->opcode & ISCSI_OPCODE_MASK) == ISCSI_OP_LOGOUT)
 662                 session->state = ISCSI_STATE_LOGGING_OUT;
 663
 664         task->state = ISCSI_TASK_RUNNING;
 665         ISCSI_DBG_SESSION(session, "mgmtpdu [op 0x%x hdr->itt 0x%x "
 666                           "datalen %d]\n", hdr->opcode & ISCSI_OPCODE_MASK,
 667                           hdr->itt, task->data_count);
 668         return 0;
 669 }
 670
 671 static struct iscsi_task *
 672 __iscsi_conn_send_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 673                       char *data, uint32_t data_size)
 674 {
 675         struct iscsi_session *session = conn->session;
 676         struct iscsi_host *ihost = shost_priv(session->host);
 677         uint8_t opcode = hdr->opcode & ISCSI_OPCODE_MASK;
 678         struct iscsi_task *task;
 679         itt_t itt;
 680
 681         if (session->state == ISCSI_STATE_TERMINATE)
 682                 return NULL;
 683
 684         if (opcode == ISCSI_OP_LOGIN || opcode == ISCSI_OP_TEXT) {
 685                 /*
 686                  * Login and Text are sent serially, in
 687                  * request-followed-by-response sequence.
 688                  * Same task can be used. Same ITT must be used.
 689                  * Note that login_task is preallocated at conn_create().
 690                  */
 691                 if (conn->login_task->state != ISCSI_TASK_FREE) {
 692                         iscsi_conn_printk(KERN_ERR, conn, "Login/Text in "
 693                                           "progress. Cannot start new task.\n");
 694                         return NULL;
 695                 }
 696
 697                 if (data_size > ISCSI_DEF_MAX_RECV_SEG_LEN) {
 698                         iscsi_conn_printk(KERN_ERR, conn, "Invalid buffer len of %u for login task. Max len is %u\n", data_size, ISCSI_DEF_MAX_RECV_SEG_LEN);
 699                         return NULL;
 700                 }
 701
 702                 task = conn->login_task;
 703         } else {
 704                 if (session->state != ISCSI_STATE_LOGGED_IN)
 705                         return NULL;
 706
 707                 if (data_size != 0) {
 708                         iscsi_conn_printk(KERN_ERR, conn, "Can not send data buffer of len %u for op 0x%x\n", data_size, opcode);
 709                         return NULL;
 710                 }
 711
 712                 BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
 713                 BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);
 714
 715                 if (!kfifo_out(&session->cmdpool.queue,
 716                                  (void*)&task, sizeof(void*)))
 717                         return NULL;
 718         }
 719         /*
 720          * released in complete pdu for task we expect a response for, and
 721          * released by the lld when it has transmitted the task for
 722          * pdus we do not expect a response for.
 723          */
 724         refcount_set(&task->refcount, 1);
 725         task->conn = conn;
 726         task->sc = NULL;
 727         INIT_LIST_HEAD(&task->running);
 728         task->state = ISCSI_TASK_PENDING;
 729
 730         if (data_size) {
 731                 memcpy(task->data, data, data_size);
 732                 task->data_count = data_size;
 733         } else
 734                 task->data_count = 0;
 735
 736         if (conn->session->tt->alloc_pdu) {
 737                 if (conn->session->tt->alloc_pdu(task, hdr->opcode)) {
 738                         iscsi_conn_printk(KERN_ERR, conn, "Could not allocate "
 739                                          "pdu for mgmt task.\n");
 740                         goto free_task;
 741                 }
 742         }
 743
 744         itt = task->hdr->itt;
 745         task->hdr_len = sizeof(struct iscsi_hdr);
 746         memcpy(task->hdr, hdr, sizeof(struct iscsi_hdr));
 747
 748         if (hdr->itt != RESERVED_ITT) {
 749                 if (session->tt->parse_pdu_itt)
 750                         task->hdr->itt = itt;
 751                 else
 752                         task->hdr->itt = build_itt(task->itt,
 753                                                    task->conn->session->age);
 754         }
 755
 756         if (unlikely(READ_ONCE(conn->ping_task) == INVALID_SCSI_TASK))
 757                 WRITE_ONCE(conn->ping_task, task);
 758
 759         if (!ihost->workq) {
 760                 if (iscsi_prep_mgmt_task(conn, task))
 761                         goto free_task;
 762
 763                 if (session->tt->xmit_task(task))
 764                         goto free_task;
 765         } else {
 766                 list_add_tail(&task->running, &conn->mgmtqueue);
 767                 iscsi_conn_queue_work(conn);
 768         }
 769
 770         return task;
 771
 772 free_task:
 773         /* regular RX path uses back_lock */
 774         spin_lock(&session->back_lock);
 775         __iscsi_put_task(task);
 776         spin_unlock(&session->back_lock);
 777         return NULL;
 778 }
 779
 780 int iscsi_conn_send_pdu(struct iscsi_cls_conn *cls_conn, struct iscsi_hdr *hdr,
 781                         char *data, uint32_t data_size)
 782 {
 783         struct iscsi_conn *conn = cls_conn->dd_data;
 784         struct iscsi_session *session = conn->session;
 785         int err = 0;
 786
 787         spin_lock_bh(&session->frwd_lock);
 788         if (!__iscsi_conn_send_pdu(conn, hdr, data, data_size))
 789                 err = -EPERM;
 790         spin_unlock_bh(&session->frwd_lock);
 791         return err;
 792 }
 793 EXPORT_SYMBOL_GPL(iscsi_conn_send_pdu);
 794
 795 /**
 796  * iscsi_scsi_cmd_rsp - SCSI Command Response processing
 797  * @conn: iscsi connection
 798  * @hdr: iscsi header
 799  * @task: scsi command task
 800  * @data: cmd data buffer
 801  * @datalen: len of buffer
 802  *
 803  * iscsi_cmd_rsp sets up the scsi_cmnd fields based on the PDU and
 804  * then completes the command and task. called under back_lock
 805  **/
 806 static void iscsi_scsi_cmd_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 807                                struct iscsi_task *task, char *data,
 808                                int datalen)
 809 {
 810         struct iscsi_scsi_rsp *rhdr = (struct iscsi_scsi_rsp *)hdr;
 811         struct iscsi_session *session = conn->session;
 812         struct scsi_cmnd *sc = task->sc;
 813
 814         iscsi_update_cmdsn(session, (struct iscsi_nopin*)rhdr);
 815         conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 816
 817         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 818
 819         if (task->protected) {
 820                 sector_t sector;
 821                 u8 ascq;
 822
 823                 /**
 824                  * Transports that didn't implement check_protection
 825                  * callback but still published T10-PI support to scsi-mid
 826                  * deserve this BUG_ON.
 827                  **/
 828                 BUG_ON(!session->tt->check_protection);
 829
 830                 ascq = session->tt->check_protection(task, &sector);
 831                 if (ascq) {
 832                         scsi_build_sense(sc, 1, ILLEGAL_REQUEST, 0x10, ascq);
 833                         scsi_set_sense_information(sc->sense_buffer,
 834                                                    SCSI_SENSE_BUFFERSIZE,
 835                                                    sector);
 836                         goto out;
 837                 }
 838         }
 839
 840         if (rhdr->response != ISCSI_STATUS_CMD_COMPLETED) {
 841                 sc->result = DID_ERROR << 16;
 842                 goto out;
 843         }
 844
 845         if (rhdr->cmd_status == SAM_STAT_CHECK_CONDITION) {
 846                 uint16_t senselen;
 847
 848                 if (datalen < 2) {
 849 invalid_datalen:
 850                         iscsi_conn_printk(KERN_ERR,  conn,
 851                                          "Got CHECK_CONDITION but invalid data "
 852                                          "buffer size of %d\n", datalen);
 853                         sc->result = DID_BAD_TARGET << 16;
 854                         goto out;
 855                 }
 856
 857                 senselen = get_unaligned_be16(data);
 858                 if (datalen < senselen)
 859                         goto invalid_datalen;
 860
 861                 memcpy(sc->sense_buffer, data + 2,
 862                        min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
 863                 ISCSI_DBG_SESSION(session, "copied %d bytes of sense\n",
 864                                   min_t(uint16_t, senselen,
 865                                   SCSI_SENSE_BUFFERSIZE));
 866         }
 867
 868         if (rhdr->flags & (ISCSI_FLAG_CMD_BIDI_UNDERFLOW |
 869                            ISCSI_FLAG_CMD_BIDI_OVERFLOW)) {
 870                 sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 871         }
 872
 873         if (rhdr->flags & (ISCSI_FLAG_CMD_UNDERFLOW |
 874                            ISCSI_FLAG_CMD_OVERFLOW)) {
 875                 int res_count = be32_to_cpu(rhdr->residual_count);
 876
 877                 if (res_count > 0 &&
 878                     (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
 879                      res_count <= scsi_bufflen(sc)))
 880                         /* write side for bidi or uni-io set_resid */
 881                         scsi_set_resid(sc, res_count);
 882                 else
 883                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 884         }
 885 out:
 886         ISCSI_DBG_SESSION(session, "cmd rsp done [sc %p res %d itt 0x%x]\n",
 887                           sc, sc->result, task->itt);
 888         conn->scsirsp_pdus_cnt++;
 889         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 890 }
 891
 892 /**
 893  * iscsi_data_in_rsp - SCSI Data-In Response processing
 894  * @conn: iscsi connection
 895  * @hdr:  iscsi pdu
 896  * @task: scsi command task
 897  *
 898  * iscsi_data_in_rsp sets up the scsi_cmnd fields based on the data received
 899  * then completes the command and task. called under back_lock
 900  **/
 901 static void
 902 iscsi_data_in_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 903                   struct iscsi_task *task)
 904 {
 905         struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)hdr;
 906         struct scsi_cmnd *sc = task->sc;
 907
 908         if (!(rhdr->flags & ISCSI_FLAG_DATA_STATUS))
 909                 return;
 910
 911         iscsi_update_cmdsn(conn->session, (struct iscsi_nopin *)hdr);
 912         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 913         conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 914         if (rhdr->flags & (ISCSI_FLAG_DATA_UNDERFLOW |
 915                            ISCSI_FLAG_DATA_OVERFLOW)) {
 916                 int res_count = be32_to_cpu(rhdr->residual_count);
 917
 918                 if (res_count > 0 &&
 919                     (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
 920                      res_count <= sc->sdb.length))
 921                         scsi_set_resid(sc, res_count);
 922                 else
 923                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 924         }
 925
 926         ISCSI_DBG_SESSION(conn->session, "data in with status done "
 927                           "[sc %p res %d itt 0x%x]\n",
 928                           sc, sc->result, task->itt);
 929         conn->scsirsp_pdus_cnt++;
 930         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 931 }
 932
 933 static void iscsi_tmf_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
 934 {
 935         struct iscsi_tm_rsp *tmf = (struct iscsi_tm_rsp *)hdr;
 936         struct iscsi_session *session = conn->session;
 937
 938         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 939         conn->tmfrsp_pdus_cnt++;
 940
 941         if (session->tmf_state != TMF_QUEUED)
 942                 return;
 943
 944         if (tmf->response == ISCSI_TMF_RSP_COMPLETE)
 945                 session->tmf_state = TMF_SUCCESS;
 946         else if (tmf->response == ISCSI_TMF_RSP_NO_TASK)
 947                 session->tmf_state = TMF_NOT_FOUND;
 948         else
 949                 session->tmf_state = TMF_FAILED;
 950         wake_up(&session->ehwait);
 951 }
 952
 953 static int iscsi_send_nopout(struct iscsi_conn *conn, struct iscsi_nopin *rhdr)
 954 {
 955         struct iscsi_nopout hdr;
 956         struct iscsi_task *task;
 957
 958         if (!rhdr) {
 959                 if (READ_ONCE(conn->ping_task))
 960                         return -EINVAL;
 961                 WRITE_ONCE(conn->ping_task, INVALID_SCSI_TASK);
 962         }
 963
 964         memset(&hdr, 0, sizeof(struct iscsi_nopout));
 965         hdr.opcode = ISCSI_OP_NOOP_OUT | ISCSI_OP_IMMEDIATE;
 966         hdr.flags = ISCSI_FLAG_CMD_FINAL;
 967
 968         if (rhdr) {
 969                 hdr.lun = rhdr->lun;
 970                 hdr.ttt = rhdr->ttt;
 971                 hdr.itt = RESERVED_ITT;
 972         } else
 973                 hdr.ttt = RESERVED_ITT;
 974
 975         task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)&hdr, NULL, 0);
 976         if (!task) {
 977                 if (!rhdr)
 978                         WRITE_ONCE(conn->ping_task, NULL);
 979                 iscsi_conn_printk(KERN_ERR, conn, "Could not send nopout\n");
 980                 return -EIO;
 981         } else if (!rhdr) {
 982                 /* only track our nops */
 983                 conn->last_ping = jiffies;
 984         }
 985
 986         return 0;
 987 }
 988
 989 /**
 990  * iscsi_nop_out_rsp - SCSI NOP Response processing
 991  * @task: scsi command task
 992  * @nop: the nop structure
 993  * @data: where to put the data
 994  * @datalen: length of data
 995  *
 996  * iscsi_nop_out_rsp handles nop response from use or
 997  * from user space. called under back_lock
 998  **/
 999 static int iscsi_nop_out_rsp(struct iscsi_task *task,
1000                              struct iscsi_nopin *nop, char *data, int datalen)
1001 {
1002         struct iscsi_conn *conn = task->conn;
1003         int rc = 0;
1004
1005         if (READ_ONCE(conn->ping_task) != task) {
1006                 /*
1007                  * If this is not in response to one of our
1008                  * nops then it must be from userspace.
1009                  */
1010                 if (iscsi_recv_pdu(conn->cls_conn, (struct iscsi_hdr *)nop,
1011                                    data, datalen))
1012                         rc = ISCSI_ERR_CONN_FAILED;
1013         } else
1014                 mod_timer(&conn->transport_timer, jiffies + conn->recv_timeout);
1015         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1016         return rc;
1017 }
1018
1019 static int iscsi_handle_reject(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1020                                char *data, int datalen)
1021 {
1022         struct iscsi_reject *reject = (struct iscsi_reject *)hdr;
1023         struct iscsi_hdr rejected_pdu;
1024         int opcode, rc = 0;
1025
1026         conn->exp_statsn = be32_to_cpu(reject->statsn) + 1;
1027
1028         if (ntoh24(reject->dlength) > datalen ||
1029             ntoh24(reject->dlength) < sizeof(struct iscsi_hdr)) {
1030                 iscsi_conn_printk(KERN_ERR, conn, "Cannot handle rejected "
1031                                   "pdu. Invalid data length (pdu dlength "
1032                                   "%u, datalen %d\n", ntoh24(reject->dlength),
1033                                   datalen);
1034                 return ISCSI_ERR_PROTO;
1035         }
1036         memcpy(&rejected_pdu, data, sizeof(struct iscsi_hdr));
1037         opcode = rejected_pdu.opcode & ISCSI_OPCODE_MASK;
1038
1039         switch (reject->reason) {
1040         case ISCSI_REASON_DATA_DIGEST_ERROR:
1041                 iscsi_conn_printk(KERN_ERR, conn,
1042                                   "pdu (op 0x%x itt 0x%x) rejected "
1043                                   "due to DataDigest error.\n",
1044                                   opcode, rejected_pdu.itt);
1045                 break;
1046         case ISCSI_REASON_IMM_CMD_REJECT:
1047                 iscsi_conn_printk(KERN_ERR, conn,
1048                                   "pdu (op 0x%x itt 0x%x) rejected. Too many "
1049                                   "immediate commands.\n",
1050                                   opcode, rejected_pdu.itt);
1051                 /*
1052                  * We only send one TMF at a time so if the target could not
1053                  * handle it, then it should get fixed (RFC mandates that
1054                  * a target can handle one immediate TMF per conn).
1055                  *
1056                  * For nops-outs, we could have sent more than one if
1057                  * the target is sending us lots of nop-ins
1058                  */
1059                 if (opcode != ISCSI_OP_NOOP_OUT)
1060                         return 0;
1061
1062                 if (rejected_pdu.itt == cpu_to_be32(ISCSI_RESERVED_TAG)) {
1063                         /*
1064                          * nop-out in response to target's nop-out rejected.
1065                          * Just resend.
1066                          */
1067                         /* In RX path we are under back lock */
1068                         spin_unlock(&conn->session->back_lock);
1069                         spin_lock(&conn->session->frwd_lock);
1070                         iscsi_send_nopout(conn,
1071                                           (struct iscsi_nopin*)&rejected_pdu);
1072                         spin_unlock(&conn->session->frwd_lock);
1073                         spin_lock(&conn->session->back_lock);
1074                 } else {
1075                         struct iscsi_task *task;
1076                         /*
1077                          * Our nop as ping got dropped. We know the target
1078                          * and transport are ok so just clean up
1079                          */
1080                         task = iscsi_itt_to_task(conn, rejected_pdu.itt);
1081                         if (!task) {
1082                                 iscsi_conn_printk(KERN_ERR, conn,
1083                                                  "Invalid pdu reject. Could "
1084                                                  "not lookup rejected task.\n");
1085                                 rc = ISCSI_ERR_BAD_ITT;
1086                         } else
1087                                 rc = iscsi_nop_out_rsp(task,
1088                                         (struct iscsi_nopin*)&rejected_pdu,
1089                                         NULL, 0);
1090                 }
1091                 break;
1092         default:
1093                 iscsi_conn_printk(KERN_ERR, conn,
1094                                   "pdu (op 0x%x itt 0x%x) rejected. Reason "
1095                                   "code 0x%x\n", rejected_pdu.opcode,
1096                                   rejected_pdu.itt, reject->reason);
1097                 break;
1098         }
1099         return rc;
1100 }
1101
1102 /**
1103  * iscsi_itt_to_task - look up task by itt
1104  * @conn: iscsi connection
1105  * @itt: itt
1106  *
1107  * This should be used for mgmt tasks like login and nops, or if
1108  * the LDD's itt space does not include the session age.
1109  *
1110  * The session back_lock must be held.
1111  */
1112 struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *conn, itt_t itt)
1113 {
1114         struct iscsi_session *session = conn->session;
1115         int i;
1116
1117         if (itt == RESERVED_ITT)
1118                 return NULL;
1119
1120         if (session->tt->parse_pdu_itt)
1121                 session->tt->parse_pdu_itt(conn, itt, &i, NULL);
1122         else
1123                 i = get_itt(itt);
1124         if (i >= session->cmds_max)
1125                 return NULL;
1126
1127         return session->cmds[i];
1128 }
1129 EXPORT_SYMBOL_GPL(iscsi_itt_to_task);
1130
1131 /**
1132  * __iscsi_complete_pdu - complete pdu
1133  * @conn: iscsi conn
1134  * @hdr: iscsi header
1135  * @data: data buffer
1136  * @datalen: len of data buffer
1137  *
1138  * Completes pdu processing by freeing any resources allocated at
1139  * queuecommand or send generic. session back_lock must be held and verify
1140  * itt must have been called.
1141  */
1142 int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1143                          char *data, int datalen)
1144 {
1145         struct iscsi_session *session = conn->session;
1146         int opcode = hdr->opcode & ISCSI_OPCODE_MASK, rc = 0;
1147         struct iscsi_task *task;
1148         uint32_t itt;
1149
1150         conn->last_recv = jiffies;
1151         rc = iscsi_verify_itt(conn, hdr->itt);
1152         if (rc)
1153                 return rc;
1154
1155         if (hdr->itt != RESERVED_ITT)
1156                 itt = get_itt(hdr->itt);
1157         else
1158                 itt = ~0U;
1159
1160         ISCSI_DBG_SESSION(session, "[op 0x%x cid %d itt 0x%x len %d]\n",
1161                           opcode, conn->id, itt, datalen);
1162
1163         if (itt == ~0U) {
1164                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1165
1166                 switch(opcode) {
1167                 case ISCSI_OP_NOOP_IN:
1168                         if (datalen) {
1169                                 rc = ISCSI_ERR_PROTO;
1170                                 break;
1171                         }
1172
1173                         if (hdr->ttt == cpu_to_be32(ISCSI_RESERVED_TAG))
1174                                 break;
1175
1176                         /* In RX path we are under back lock */
1177                         spin_unlock(&session->back_lock);
1178                         spin_lock(&session->frwd_lock);
1179                         iscsi_send_nopout(conn, (struct iscsi_nopin*)hdr);
1180                         spin_unlock(&session->frwd_lock);
1181                         spin_lock(&session->back_lock);
1182                         break;
1183                 case ISCSI_OP_REJECT:
1184                         rc = iscsi_handle_reject(conn, hdr, data, datalen);
1185                         break;
1186                 case ISCSI_OP_ASYNC_EVENT:
1187                         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1188                         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
1189                                 rc = ISCSI_ERR_CONN_FAILED;
1190                         break;
1191                 default:
1192                         rc = ISCSI_ERR_BAD_OPCODE;
1193                         break;
1194                 }
1195                 goto out;
1196         }
1197
1198         switch(opcode) {
1199         case ISCSI_OP_SCSI_CMD_RSP:
1200         case ISCSI_OP_SCSI_DATA_IN:
1201                 task = iscsi_itt_to_ctask(conn, hdr->itt);
1202                 if (!task)
1203                         return ISCSI_ERR_BAD_ITT;
1204                 task->last_xfer = jiffies;
1205                 break;
1206         case ISCSI_OP_R2T:
1207                 /*
1208                  * LLD handles R2Ts if they need to.
1209                  */
1210                 return 0;
1211         case ISCSI_OP_LOGOUT_RSP:
1212         case ISCSI_OP_LOGIN_RSP:
1213         case ISCSI_OP_TEXT_RSP:
1214         case ISCSI_OP_SCSI_TMFUNC_RSP:
1215         case ISCSI_OP_NOOP_IN:
1216                 task = iscsi_itt_to_task(conn, hdr->itt);
1217                 if (!task)
1218                         return ISCSI_ERR_BAD_ITT;
1219                 break;
1220         default:
1221                 return ISCSI_ERR_BAD_OPCODE;
1222         }
1223
1224         switch(opcode) {
1225         case ISCSI_OP_SCSI_CMD_RSP:
1226                 iscsi_scsi_cmd_rsp(conn, hdr, task, data, datalen);
1227                 break;
1228         case ISCSI_OP_SCSI_DATA_IN:
1229                 iscsi_data_in_rsp(conn, hdr, task);
1230                 break;
1231         case ISCSI_OP_LOGOUT_RSP:
1232                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1233                 if (datalen) {
1234                         rc = ISCSI_ERR_PROTO;
1235                         break;
1236                 }
1237                 conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1238                 goto recv_pdu;
1239         case ISCSI_OP_LOGIN_RSP:
1240         case ISCSI_OP_TEXT_RSP:
1241                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1242                 /*
1243                  * login related PDU's exp_statsn is handled in
1244                  * userspace
1245                  */
1246                 goto recv_pdu;
1247         case ISCSI_OP_SCSI_TMFUNC_RSP:
1248                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1249                 if (datalen) {
1250                         rc = ISCSI_ERR_PROTO;
1251                         break;
1252                 }
1253
1254                 iscsi_tmf_rsp(conn, hdr);
1255                 iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1256                 break;
1257         case ISCSI_OP_NOOP_IN:
1258                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1259                 if (hdr->ttt != cpu_to_be32(ISCSI_RESERVED_TAG) || datalen) {
1260                         rc = ISCSI_ERR_PROTO;
1261                         break;
1262                 }
1263                 conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1264
1265                 rc = iscsi_nop_out_rsp(task, (struct iscsi_nopin*)hdr,
1266                                        data, datalen);
1267                 break;
1268         default:
1269                 rc = ISCSI_ERR_BAD_OPCODE;
1270                 break;
1271         }
1272
1273 out:
1274         return rc;
1275 recv_pdu:
1276         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
1277                 rc = ISCSI_ERR_CONN_FAILED;
1278         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1279         return rc;
1280 }
1281 EXPORT_SYMBOL_GPL(__iscsi_complete_pdu);
1282
1283 int iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1284                        char *data, int datalen)
1285 {
1286         int rc;
1287
1288         spin_lock(&conn->session->back_lock);
1289         rc = __iscsi_complete_pdu(conn, hdr, data, datalen);
1290         spin_unlock(&conn->session->back_lock);
1291         return rc;
1292 }
1293 EXPORT_SYMBOL_GPL(iscsi_complete_pdu);
1294
1295 int iscsi_verify_itt(struct iscsi_conn *conn, itt_t itt)
1296 {
1297         struct iscsi_session *session = conn->session;
1298         int age = 0, i = 0;
1299
1300         if (itt == RESERVED_ITT)
1301                 return 0;
1302
1303         if (session->tt->parse_pdu_itt)
1304                 session->tt->parse_pdu_itt(conn, itt, &i, &age);
1305         else {
1306                 i = get_itt(itt);
1307                 age = ((__force u32)itt >> ISCSI_AGE_SHIFT) & ISCSI_AGE_MASK;
1308         }
1309
1310         if (age != session->age) {
1311                 iscsi_conn_printk(KERN_ERR, conn,
1312                                   "received itt %x expected session age (%x)\n",
1313                                   (__force u32)itt, session->age);
1314                 return ISCSI_ERR_BAD_ITT;
1315         }
1316
1317         if (i >= session->cmds_max) {
1318                 iscsi_conn_printk(KERN_ERR, conn,
1319                                   "received invalid itt index %u (max cmds "
1320                                    "%u.\n", i, session->cmds_max);
1321                 return ISCSI_ERR_BAD_ITT;
1322         }
1323         return 0;
1324 }
1325 EXPORT_SYMBOL_GPL(iscsi_verify_itt);
1326
1327 /**
1328  * iscsi_itt_to_ctask - look up ctask by itt
1329  * @conn: iscsi connection
1330  * @itt: itt
1331  *
1332  * This should be used for cmd tasks.
1333  *
1334  * The session back_lock must be held.
1335  */
1336 struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *conn, itt_t itt)
1337 {
1338         struct iscsi_task *task;
1339
1340         if (iscsi_verify_itt(conn, itt))
1341                 return NULL;
1342
1343         task = iscsi_itt_to_task(conn, itt);
1344         if (!task || !task->sc)
1345                 return NULL;
1346
1347         if (task->sc->SCp.phase != conn->session->age) {
1348                 iscsi_session_printk(KERN_ERR, conn->session,
1349                                   "task's session age %d, expected %d\n",
1350                                   task->sc->SCp.phase, conn->session->age);
1351                 return NULL;
1352         }
1353
1354         return task;
1355 }
1356 EXPORT_SYMBOL_GPL(iscsi_itt_to_ctask);
1357
1358 void iscsi_session_failure(struct iscsi_session *session,
1359                            enum iscsi_err err)
1360 {
1361         struct iscsi_conn *conn;
1362
1363         spin_lock_bh(&session->frwd_lock);
1364         conn = session->leadconn;
1365         if (session->state == ISCSI_STATE_TERMINATE || !conn) {
1366                 spin_unlock_bh(&session->frwd_lock);
1367                 return;
1368         }
1369
1370         iscsi_get_conn(conn->cls_conn);
1371         spin_unlock_bh(&session->frwd_lock);
1372         /*
1373          * if the host is being removed bypass the connection
1374          * recovery initialization because we are going to kill
1375          * the session.
1376          */
1377         if (err == ISCSI_ERR_INVALID_HOST)
1378                 iscsi_conn_error_event(conn->cls_conn, err);
1379         else
1380                 iscsi_conn_failure(conn, err);
1381         iscsi_put_conn(conn->cls_conn);
1382 }
1383 EXPORT_SYMBOL_GPL(iscsi_session_failure);
1384
1385 static bool iscsi_set_conn_failed(struct iscsi_conn *conn)
1386 {
1387         struct iscsi_session *session = conn->session;
1388
1389         if (session->state == ISCSI_STATE_FAILED)
1390                 return false;
1391
1392         if (conn->stop_stage == 0)
1393                 session->state = ISCSI_STATE_FAILED;
1394
1395         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1396         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
1397         return true;
1398 }
1399
1400 void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err)
1401 {
1402         struct iscsi_session *session = conn->session;
1403         bool needs_evt;
1404
1405         spin_lock_bh(&session->frwd_lock);
1406         needs_evt = iscsi_set_conn_failed(conn);
1407         spin_unlock_bh(&session->frwd_lock);
1408
1409         if (needs_evt)
1410                 iscsi_conn_error_event(conn->cls_conn, err);
1411 }
1412 EXPORT_SYMBOL_GPL(iscsi_conn_failure);
1413
1414 static int iscsi_check_cmdsn_window_closed(struct iscsi_conn *conn)
1415 {
1416         struct iscsi_session *session = conn->session;
1417
1418         /*
1419          * Check for iSCSI window and take care of CmdSN wrap-around
1420          */
1421         if (!iscsi_sna_lte(session->queued_cmdsn, session->max_cmdsn)) {
1422                 ISCSI_DBG_SESSION(session, "iSCSI CmdSN closed. ExpCmdSn "
1423                                   "%u MaxCmdSN %u CmdSN %u/%u\n",
1424                                   session->exp_cmdsn, session->max_cmdsn,
1425                                   session->cmdsn, session->queued_cmdsn);
1426                 return -ENOSPC;
1427         }
1428         return 0;
1429 }
1430
1431 static int iscsi_xmit_task(struct iscsi_conn *conn, struct iscsi_task *task,
1432                            bool was_requeue)
1433 {
1434         int rc;
1435
1436         spin_lock_bh(&conn->session->back_lock);
1437
1438         if (!conn->task) {
1439                 /* Take a ref so we can access it after xmit_task() */
1440                 __iscsi_get_task(task);
1441         } else {
1442                 /* Already have a ref from when we failed to send it last call */
1443                 conn->task = NULL;
1444         }
1445
1446         /*
1447          * If this was a requeue for a R2T we have an extra ref on the task in
1448          * case a bad target sends a cmd rsp before we have handled the task.
1449          */
1450         if (was_requeue)
1451                 __iscsi_put_task(task);
1452
1453         /*
1454          * Do this after dropping the extra ref because if this was a requeue
1455          * it's removed from that list and cleanup_queued_task would miss it.
1456          */
1457         if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx)) {
1458                 /*
1459                  * Save the task and ref in case we weren't cleaning up this
1460                  * task and get woken up again.
1461                  */
1462                 conn->task = task;
1463                 spin_unlock_bh(&conn->session->back_lock);
1464                 return -ENODATA;
1465         }
1466         spin_unlock_bh(&conn->session->back_lock);
1467
1468         spin_unlock_bh(&conn->session->frwd_lock);
1469         rc = conn->session->tt->xmit_task(task);
1470         spin_lock_bh(&conn->session->frwd_lock);
1471         if (!rc) {
1472                 /* done with this task */
1473                 task->last_xfer = jiffies;
1474         }
1475         /* regular RX path uses back_lock */
1476         spin_lock(&conn->session->back_lock);
1477         if (rc && task->state == ISCSI_TASK_RUNNING) {
1478                 /*
1479                  * get an extra ref that is released next time we access it
1480                  * as conn->task above.
1481                  */
1482                 __iscsi_get_task(task);
1483                 conn->task = task;
1484         }
1485
1486         __iscsi_put_task(task);
1487         spin_unlock(&conn->session->back_lock);
1488         return rc;
1489 }
1490
1491 /**
1492  * iscsi_requeue_task - requeue task to run from session workqueue
1493  * @task: task to requeue
1494  *
1495  * Callers must have taken a ref to the task that is going to be requeued.
1496  */
1497 void iscsi_requeue_task(struct iscsi_task *task)
1498 {
1499         struct iscsi_conn *conn = task->conn;
1500
1501         /*
1502          * this may be on the requeue list already if the xmit_task callout
1503          * is handling the r2ts while we are adding new ones
1504          */
1505         spin_lock_bh(&conn->session->frwd_lock);
1506         if (list_empty(&task->running)) {
1507                 list_add_tail(&task->running, &conn->requeue);
1508         } else {
1509                 /*
1510                  * Don't need the extra ref since it's already requeued and
1511                  * has a ref.
1512                  */
1513                 iscsi_put_task(task);
1514         }
1515         iscsi_conn_queue_work(conn);
1516         spin_unlock_bh(&conn->session->frwd_lock);
1517 }
1518 EXPORT_SYMBOL_GPL(iscsi_requeue_task);
1519
1520 /**
1521  * iscsi_data_xmit - xmit any command into the scheduled connection
1522  * @conn: iscsi connection
1523  *
1524  * Notes:
1525  *      The function can return -EAGAIN in which case the caller must
1526  *      re-schedule it again later or recover. '0' return code means
1527  *      successful xmit.
1528  **/
1529 static int iscsi_data_xmit(struct iscsi_conn *conn)
1530 {
1531         struct iscsi_task *task;
1532         int rc = 0;
1533
1534         spin_lock_bh(&conn->session->frwd_lock);
1535         if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx)) {
1536                 ISCSI_DBG_SESSION(conn->session, "Tx suspended!\n");
1537                 spin_unlock_bh(&conn->session->frwd_lock);
1538                 return -ENODATA;
1539         }
1540
1541         if (conn->task) {
1542                 rc = iscsi_xmit_task(conn, conn->task, false);
1543                 if (rc)
1544                         goto done;
1545         }
1546
1547         /*
1548          * process mgmt pdus like nops before commands since we should
1549          * only have one nop-out as a ping from us and targets should not
1550          * overflow us with nop-ins
1551          */
1552 check_mgmt:
1553         while (!list_empty(&conn->mgmtqueue)) {
1554                 task = list_entry(conn->mgmtqueue.next, struct iscsi_task,
1555                                   running);
1556                 list_del_init(&task->running);
1557                 if (iscsi_prep_mgmt_task(conn, task)) {
1558                         /* regular RX path uses back_lock */
1559                         spin_lock_bh(&conn->session->back_lock);
1560                         __iscsi_put_task(task);
1561                         spin_unlock_bh(&conn->session->back_lock);
1562                         continue;
1563                 }
1564                 rc = iscsi_xmit_task(conn, task, false);
1565                 if (rc)
1566                         goto done;
1567         }
1568
1569         /* process pending command queue */
1570         while (!list_empty(&conn->cmdqueue)) {
1571                 task = list_entry(conn->cmdqueue.next, struct iscsi_task,
1572                                   running);
1573                 list_del_init(&task->running);
1574                 if (conn->session->state == ISCSI_STATE_LOGGING_OUT) {
1575                         fail_scsi_task(task, DID_IMM_RETRY);
1576                         continue;
1577                 }
1578                 rc = iscsi_prep_scsi_cmd_pdu(task);
1579                 if (rc) {
1580                         if (rc == -ENOMEM || rc == -EACCES)
1581                                 fail_scsi_task(task, DID_IMM_RETRY);
1582                         else
1583                                 fail_scsi_task(task, DID_ABORT);
1584                         continue;
1585                 }
1586                 rc = iscsi_xmit_task(conn, task, false);
1587                 if (rc)
1588                         goto done;
1589                 /*
1590                  * we could continuously get new task requests so
1591                  * we need to check the mgmt queue for nops that need to
1592                  * be sent to aviod starvation
1593                  */
1594                 if (!list_empty(&conn->mgmtqueue))
1595                         goto check_mgmt;
1596         }
1597
1598         while (!list_empty(&conn->requeue)) {
1599                 /*
1600                  * we always do fastlogout - conn stop code will clean up.
1601                  */
1602                 if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
1603                         break;
1604
1605                 task = list_entry(conn->requeue.next, struct iscsi_task,
1606                                   running);
1607
1608                 if (iscsi_check_tmf_restrictions(task, ISCSI_OP_SCSI_DATA_OUT))
1609                         break;
1610
1611                 list_del_init(&task->running);
1612                 rc = iscsi_xmit_task(conn, task, true);
1613                 if (rc)
1614                         goto done;
1615                 if (!list_empty(&conn->mgmtqueue))
1616                         goto check_mgmt;
1617         }
1618         spin_unlock_bh(&conn->session->frwd_lock);
1619         return -ENODATA;
1620
1621 done:
1622         spin_unlock_bh(&conn->session->frwd_lock);
1623         return rc;
1624 }
1625
1626 static void iscsi_xmitworker(struct work_struct *work)
1627 {
1628         struct iscsi_conn *conn =
1629                 container_of(work, struct iscsi_conn, xmitwork);
1630         int rc;
1631         /*
1632          * serialize Xmit worker on a per-connection basis.
1633          */
1634         do {
1635                 rc = iscsi_data_xmit(conn);
1636         } while (rc >= 0 || rc == -EAGAIN);
1637 }
1638
1639 static inline struct iscsi_task *iscsi_alloc_task(struct iscsi_conn *conn,
1640                                                   struct scsi_cmnd *sc)
1641 {
1642         struct iscsi_task *task;
1643
1644         if (!kfifo_out(&conn->session->cmdpool.queue,
1645                          (void *) &task, sizeof(void *)))
1646                 return NULL;
1647
1648         sc->SCp.phase = conn->session->age;
1649         sc->SCp.ptr = (char *) task;
1650
1651         refcount_set(&task->refcount, 1);
1652         task->state = ISCSI_TASK_PENDING;
1653         task->conn = conn;
1654         task->sc = sc;
1655         task->have_checked_conn = false;
1656         task->last_timeout = jiffies;
1657         task->last_xfer = jiffies;
1658         task->protected = false;
1659         INIT_LIST_HEAD(&task->running);
1660         return task;
1661 }
1662
1663 enum {
1664         FAILURE_BAD_HOST = 1,
1665         FAILURE_SESSION_FAILED,
1666         FAILURE_SESSION_FREED,
1667         FAILURE_WINDOW_CLOSED,
1668         FAILURE_OOM,
1669         FAILURE_SESSION_TERMINATE,
1670         FAILURE_SESSION_IN_RECOVERY,
1671         FAILURE_SESSION_RECOVERY_TIMEOUT,
1672         FAILURE_SESSION_LOGGING_OUT,
1673         FAILURE_SESSION_NOT_READY,
1674 };
1675
1676 int iscsi_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *sc)
1677 {
1678         struct iscsi_cls_session *cls_session;
1679         struct iscsi_host *ihost;
1680         int reason = 0;
1681         struct iscsi_session *session;
1682         struct iscsi_conn *conn;
1683         struct iscsi_task *task = NULL;
1684
1685         sc->result = 0;
1686         sc->SCp.ptr = NULL;
1687
1688         ihost = shost_priv(host);
1689
1690         cls_session = starget_to_session(scsi_target(sc->device));
1691         session = cls_session->dd_data;
1692         spin_lock_bh(&session->frwd_lock);
1693
1694         reason = iscsi_session_chkready(cls_session);
1695         if (reason) {
1696                 sc->result = reason;
1697                 goto fault;
1698         }
1699
1700         if (session->state != ISCSI_STATE_LOGGED_IN) {
1701                 /*
1702                  * to handle the race between when we set the recovery state
1703                  * and block the session we requeue here (commands could
1704                  * be entering our queuecommand while a block is starting
1705                  * up because the block code is not locked)
1706                  */
1707                 switch (session->state) {
1708                 case ISCSI_STATE_FAILED:
1709                         /*
1710                          * cmds should fail during shutdown, if the session
1711                          * state is bad, allowing completion to happen
1712                          */
1713                         if (unlikely(system_state != SYSTEM_RUNNING)) {
1714                                 reason = FAILURE_SESSION_FAILED;
1715                                 sc->result = DID_NO_CONNECT << 16;
1716                                 break;
1717                         }
1718                         fallthrough;
1719                 case ISCSI_STATE_IN_RECOVERY:
1720                         reason = FAILURE_SESSION_IN_RECOVERY;
1721                         sc->result = DID_IMM_RETRY << 16;
1722                         break;
1723                 case ISCSI_STATE_LOGGING_OUT:
1724                         reason = FAILURE_SESSION_LOGGING_OUT;
1725                         sc->result = DID_IMM_RETRY << 16;
1726                         break;
1727                 case ISCSI_STATE_RECOVERY_FAILED:
1728                         reason = FAILURE_SESSION_RECOVERY_TIMEOUT;
1729                         sc->result = DID_TRANSPORT_FAILFAST << 16;
1730                         break;
1731                 case ISCSI_STATE_TERMINATE:
1732                         reason = FAILURE_SESSION_TERMINATE;
1733                         sc->result = DID_NO_CONNECT << 16;
1734                         break;
1735                 default:
1736                         reason = FAILURE_SESSION_FREED;
1737                         sc->result = DID_NO_CONNECT << 16;
1738                 }
1739                 goto fault;
1740         }
1741
1742         conn = session->leadconn;
1743         if (!conn) {
1744                 reason = FAILURE_SESSION_FREED;
1745                 sc->result = DID_NO_CONNECT << 16;
1746                 goto fault;
1747         }
1748
1749         if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx)) {
1750                 reason = FAILURE_SESSION_IN_RECOVERY;
1751                 sc->result = DID_REQUEUE << 16;
1752                 goto fault;
1753         }
1754
1755         if (iscsi_check_cmdsn_window_closed(conn)) {
1756                 reason = FAILURE_WINDOW_CLOSED;
1757                 goto reject;
1758         }
1759
1760         task = iscsi_alloc_task(conn, sc);
1761         if (!task) {
1762                 reason = FAILURE_OOM;
1763                 goto reject;
1764         }
1765
1766         if (!ihost->workq) {
1767                 reason = iscsi_prep_scsi_cmd_pdu(task);
1768                 if (reason) {
1769                         if (reason == -ENOMEM ||  reason == -EACCES) {
1770                                 reason = FAILURE_OOM;
1771                                 goto prepd_reject;
1772                         } else {
1773                                 sc->result = DID_ABORT << 16;
1774                                 goto prepd_fault;
1775                         }
1776                 }
1777                 if (session->tt->xmit_task(task)) {
1778                         session->cmdsn--;
1779                         reason = FAILURE_SESSION_NOT_READY;
1780                         goto prepd_reject;
1781                 }
1782         } else {
1783                 list_add_tail(&task->running, &conn->cmdqueue);
1784                 iscsi_conn_queue_work(conn);
1785         }
1786
1787         session->queued_cmdsn++;
1788         spin_unlock_bh(&session->frwd_lock);
1789         return 0;
1790
1791 prepd_reject:
1792         spin_lock_bh(&session->back_lock);
1793         iscsi_complete_task(task, ISCSI_TASK_REQUEUE_SCSIQ);
1794         spin_unlock_bh(&session->back_lock);
1795 reject:
1796         spin_unlock_bh(&session->frwd_lock);
1797         ISCSI_DBG_SESSION(session, "cmd 0x%x rejected (%d)\n",
1798                           sc->cmnd[0], reason);
1799         return SCSI_MLQUEUE_TARGET_BUSY;
1800
1801 prepd_fault:
1802         spin_lock_bh(&session->back_lock);
1803         iscsi_complete_task(task, ISCSI_TASK_REQUEUE_SCSIQ);
1804         spin_unlock_bh(&session->back_lock);
1805 fault:
1806         spin_unlock_bh(&session->frwd_lock);
1807         ISCSI_DBG_SESSION(session, "iscsi: cmd 0x%x is not queued (%d)\n",
1808                           sc->cmnd[0], reason);
1809         scsi_set_resid(sc, scsi_bufflen(sc));
1810         sc->scsi_done(sc);
1811         return 0;
1812 }
1813 EXPORT_SYMBOL_GPL(iscsi_queuecommand);
1814
1815 int iscsi_target_alloc(struct scsi_target *starget)
1816 {
1817         struct iscsi_cls_session *cls_session = starget_to_session(starget);
1818         struct iscsi_session *session = cls_session->dd_data;
1819
1820         starget->can_queue = session->scsi_cmds_max;
1821         return 0;
1822 }
1823 EXPORT_SYMBOL_GPL(iscsi_target_alloc);
1824
1825 static void iscsi_tmf_timedout(struct timer_list *t)
1826 {
1827         struct iscsi_session *session = from_timer(session, t, tmf_timer);
1828
1829         spin_lock(&session->frwd_lock);
1830         if (session->tmf_state == TMF_QUEUED) {
1831                 session->tmf_state = TMF_TIMEDOUT;
1832                 ISCSI_DBG_EH(session, "tmf timedout\n");
1833                 /* unblock eh_abort() */
1834                 wake_up(&session->ehwait);
1835         }
1836         spin_unlock(&session->frwd_lock);
1837 }
1838
1839 static int iscsi_exec_task_mgmt_fn(struct iscsi_conn *conn,
1840                                    struct iscsi_tm *hdr, int age,
1841                                    int timeout)
1842         __must_hold(&session->frwd_lock)
1843 {
1844         struct iscsi_session *session = conn->session;
1845         struct iscsi_task *task;
1846
1847         task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)hdr,
1848                                       NULL, 0);
1849         if (!task) {
1850                 spin_unlock_bh(&session->frwd_lock);
1851                 iscsi_conn_printk(KERN_ERR, conn, "Could not send TMF.\n");
1852                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1853                 spin_lock_bh(&session->frwd_lock);
1854                 return -EPERM;
1855         }
1856         conn->tmfcmd_pdus_cnt++;
1857         session->tmf_timer.expires = timeout * HZ + jiffies;
1858         add_timer(&session->tmf_timer);
1859         ISCSI_DBG_EH(session, "tmf set timeout\n");
1860
1861         spin_unlock_bh(&session->frwd_lock);
1862         mutex_unlock(&session->eh_mutex);
1863
1864         /*
1865          * block eh thread until:
1866          *
1867          * 1) tmf response
1868          * 2) tmf timeout
1869          * 3) session is terminated or restarted or userspace has
1870          * given up on recovery
1871          */
1872         wait_event_interruptible(session->ehwait, age != session->age ||
1873                                  session->state != ISCSI_STATE_LOGGED_IN ||
1874                                  session->tmf_state != TMF_QUEUED);
1875         if (signal_pending(current))
1876                 flush_signals(current);
1877         del_timer_sync(&session->tmf_timer);
1878
1879         mutex_lock(&session->eh_mutex);
1880         spin_lock_bh(&session->frwd_lock);
1881         /* if the session drops it will clean up the task */
1882         if (age != session->age ||
1883             session->state != ISCSI_STATE_LOGGED_IN)
1884                 return -ENOTCONN;
1885         return 0;
1886 }
1887
1888 /*
1889  * Fail commands. session frwd lock held and xmit thread flushed.
1890  */
1891 static void fail_scsi_tasks(struct iscsi_conn *conn, u64 lun, int error)
1892 {
1893         struct iscsi_session *session = conn->session;
1894         struct iscsi_task *task;
1895         int i;
1896
1897         spin_lock_bh(&session->back_lock);
1898         for (i = 0; i < session->cmds_max; i++) {
1899                 task = session->cmds[i];
1900                 if (!task->sc || task->state == ISCSI_TASK_FREE)
1901                         continue;
1902
1903                 if (lun != -1 && lun != task->sc->device->lun)
1904                         continue;
1905
1906                 __iscsi_get_task(task);
1907                 spin_unlock_bh(&session->back_lock);
1908
1909                 ISCSI_DBG_SESSION(session,
1910                                   "failing sc %p itt 0x%x state %d\n",
1911                                   task->sc, task->itt, task->state);
1912                 fail_scsi_task(task, error);
1913
1914                 spin_unlock_bh(&session->frwd_lock);
1915                 iscsi_put_task(task);
1916                 spin_lock_bh(&session->frwd_lock);
1917
1918                 spin_lock_bh(&session->back_lock);
1919         }
1920
1921         spin_unlock_bh(&session->back_lock);
1922 }
1923
1924 /**
1925  * iscsi_suspend_queue - suspend iscsi_queuecommand
1926  * @conn: iscsi conn to stop queueing IO on
1927  *
1928  * This grabs the session frwd_lock to make sure no one is in
1929  * xmit_task/queuecommand, and then sets suspend to prevent
1930  * new commands from being queued. This only needs to be called
1931  * by offload drivers that need to sync a path like ep disconnect
1932  * with the iscsi_queuecommand/xmit_task. To start IO again libiscsi
1933  * will call iscsi_start_tx and iscsi_unblock_session when in FFP.
1934  */
1935 void iscsi_suspend_queue(struct iscsi_conn *conn)
1936 {
1937         spin_lock_bh(&conn->session->frwd_lock);
1938         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1939         spin_unlock_bh(&conn->session->frwd_lock);
1940 }
1941 EXPORT_SYMBOL_GPL(iscsi_suspend_queue);
1942
1943 /**
1944  * iscsi_suspend_tx - suspend iscsi_data_xmit
1945  * @conn: iscsi conn tp stop processing IO on.
1946  *
1947  * This function sets the suspend bit to prevent iscsi_data_xmit
1948  * from sending new IO, and if work is queued on the xmit thread
1949  * it will wait for it to be completed.
1950  */
1951 void iscsi_suspend_tx(struct iscsi_conn *conn)
1952 {
1953         struct Scsi_Host *shost = conn->session->host;
1954         struct iscsi_host *ihost = shost_priv(shost);
1955
1956         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1957         if (ihost->workq)
1958                 flush_workqueue(ihost->workq);
1959 }
1960 EXPORT_SYMBOL_GPL(iscsi_suspend_tx);
1961
1962 static void iscsi_start_tx(struct iscsi_conn *conn)
1963 {
1964         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1965         iscsi_conn_queue_work(conn);
1966 }
1967
1968 /*
1969  * We want to make sure a ping is in flight. It has timed out.
1970  * And we are not busy processing a pdu that is making
1971  * progress but got started before the ping and is taking a while
1972  * to complete so the ping is just stuck behind it in a queue.
1973  */
1974 static int iscsi_has_ping_timed_out(struct iscsi_conn *conn)
1975 {
1976         if (READ_ONCE(conn->ping_task) &&
1977             time_before_eq(conn->last_recv + (conn->recv_timeout * HZ) +
1978                            (conn->ping_timeout * HZ), jiffies))
1979                 return 1;
1980         else
1981                 return 0;
1982 }
1983
1984 enum blk_eh_timer_return iscsi_eh_cmd_timed_out(struct scsi_cmnd *sc)
1985 {
1986         enum blk_eh_timer_return rc = BLK_EH_DONE;
1987         struct iscsi_task *task = NULL, *running_task;
1988         struct iscsi_cls_session *cls_session;
1989         struct iscsi_session *session;
1990         struct iscsi_conn *conn;
1991         int i;
1992
1993         cls_session = starget_to_session(scsi_target(sc->device));
1994         session = cls_session->dd_data;
1995
1996         ISCSI_DBG_EH(session, "scsi cmd %p timedout\n", sc);
1997
1998         spin_lock_bh(&session->frwd_lock);
1999         spin_lock(&session->back_lock);
2000         task = (struct iscsi_task *)sc->SCp.ptr;
2001         if (!task) {
2002                 /*
2003                  * Raced with completion. Blk layer has taken ownership
2004                  * so let timeout code complete it now.
2005                  */
2006                 rc = BLK_EH_DONE;
2007                 spin_unlock(&session->back_lock);
2008                 goto done;
2009         }
2010         __iscsi_get_task(task);
2011         spin_unlock(&session->back_lock);
2012
2013         if (session->state != ISCSI_STATE_LOGGED_IN) {
2014                 /*
2015                  * During shutdown, if session is prematurely disconnected,
2016                  * recovery won't happen and there will be hung cmds. Not
2017                  * handling cmds would trigger EH, also bad in this case.
2018                  * Instead, handle cmd, allow completion to happen and let
2019                  * upper layer to deal with the result.
2020                  */
2021                 if (unlikely(system_state != SYSTEM_RUNNING)) {
2022                         sc->result = DID_NO_CONNECT << 16;
2023                         ISCSI_DBG_EH(session, "sc on shutdown, handled\n");
2024                         rc = BLK_EH_DONE;
2025                         goto done;
2026                 }
2027                 /*
2028                  * We are probably in the middle of iscsi recovery so let
2029                  * that complete and handle the error.
2030                  */
2031                 rc = BLK_EH_RESET_TIMER;
2032                 goto done;
2033         }
2034
2035         conn = session->leadconn;
2036         if (!conn) {
2037                 /* In the middle of shuting down */
2038                 rc = BLK_EH_RESET_TIMER;
2039                 goto done;
2040         }
2041
2042         /*
2043          * If we have sent (at least queued to the network layer) a pdu or
2044          * recvd one for the task since the last timeout ask for
2045          * more time. If on the next timeout we have not made progress
2046          * we can check if it is the task or connection when we send the
2047          * nop as a ping.
2048          */
2049         if (time_after(task->last_xfer, task->last_timeout)) {
2050                 ISCSI_DBG_EH(session, "Command making progress. Asking "
2051                              "scsi-ml for more time to complete. "
2052                              "Last data xfer at %lu. Last timeout was at "
2053                              "%lu\n.", task->last_xfer, task->last_timeout);
2054                 task->have_checked_conn = false;
2055                 rc = BLK_EH_RESET_TIMER;
2056                 goto done;
2057         }
2058
2059         if (!conn->recv_timeout && !conn->ping_timeout)
2060                 goto done;
2061         /*
2062          * if the ping timedout then we are in the middle of cleaning up
2063          * and can let the iscsi eh handle it
2064          */
2065         if (iscsi_has_ping_timed_out(conn)) {
2066                 rc = BLK_EH_RESET_TIMER;
2067                 goto done;
2068         }
2069
2070         spin_lock(&session->back_lock);
2071         for (i = 0; i < conn->session->cmds_max; i++) {
2072                 running_task = conn->session->cmds[i];
2073                 if (!running_task->sc || running_task == task ||
2074                      running_task->state != ISCSI_TASK_RUNNING)
2075                         continue;
2076
2077                 /*
2078                  * Only check if cmds started before this one have made
2079                  * progress, or this could never fail
2080                  */
2081                 if (time_after(running_task->sc->jiffies_at_alloc,
2082                                task->sc->jiffies_at_alloc))
2083                         continue;
2084
2085                 if (time_after(running_task->last_xfer, task->last_timeout)) {
2086                         /*
2087                          * This task has not made progress, but a task
2088                          * started before us has transferred data since
2089                          * we started/last-checked. We could be queueing
2090                          * too many tasks or the LU is bad.
2091                          *
2092                          * If the device is bad the cmds ahead of us on
2093                          * other devs will complete, and this loop will
2094                          * eventually fail starting the scsi eh.
2095                          */
2096                         ISCSI_DBG_EH(session, "Command has not made progress "
2097                                      "but commands ahead of it have. "
2098                                      "Asking scsi-ml for more time to "
2099                                      "complete. Our last xfer vs running task "
2100                                      "last xfer %lu/%lu. Last check %lu.\n",
2101                                      task->last_xfer, running_task->last_xfer,
2102                                      task->last_timeout);
2103                         spin_unlock(&session->back_lock);
2104                         rc = BLK_EH_RESET_TIMER;
2105                         goto done;
2106                 }
2107         }
2108         spin_unlock(&session->back_lock);
2109
2110         /* Assumes nop timeout is shorter than scsi cmd timeout */
2111         if (task->have_checked_conn)
2112                 goto done;
2113
2114         /*
2115          * Checking the transport already or nop from a cmd timeout still
2116          * running
2117          */
2118         if (READ_ONCE(conn->ping_task)) {
2119                 task->have_checked_conn = true;
2120                 rc = BLK_EH_RESET_TIMER;
2121                 goto done;
2122         }
2123
2124         /* Make sure there is a transport check done */
2125         iscsi_send_nopout(conn, NULL);
2126         task->have_checked_conn = true;
2127         rc = BLK_EH_RESET_TIMER;
2128
2129 done:
2130         spin_unlock_bh(&session->frwd_lock);
2131
2132         if (task) {
2133                 task->last_timeout = jiffies;
2134                 iscsi_put_task(task);
2135         }
2136         ISCSI_DBG_EH(session, "return %s\n", rc == BLK_EH_RESET_TIMER ?
2137                      "timer reset" : "shutdown or nh");
2138         return rc;
2139 }
2140 EXPORT_SYMBOL_GPL(iscsi_eh_cmd_timed_out);
2141
2142 static void iscsi_check_transport_timeouts(struct timer_list *t)
2143 {
2144         struct iscsi_conn *conn = from_timer(conn, t, transport_timer);
2145         struct iscsi_session *session = conn->session;
2146         unsigned long recv_timeout, next_timeout = 0, last_recv;
2147
2148         spin_lock(&session->frwd_lock);
2149         if (session->state != ISCSI_STATE_LOGGED_IN)
2150                 goto done;
2151
2152         recv_timeout = conn->recv_timeout;
2153         if (!recv_timeout)
2154                 goto done;
2155
2156         recv_timeout *= HZ;
2157         last_recv = conn->last_recv;
2158
2159         if (iscsi_has_ping_timed_out(conn)) {
2160                 iscsi_conn_printk(KERN_ERR, conn, "ping timeout of %d secs "
2161                                   "expired, recv timeout %d, last rx %lu, "
2162                                   "last ping %lu, now %lu\n",
2163                                   conn->ping_timeout, conn->recv_timeout,
2164                                   last_recv, conn->last_ping, jiffies);
2165                 spin_unlock(&session->frwd_lock);
2166                 iscsi_conn_failure(conn, ISCSI_ERR_NOP_TIMEDOUT);
2167                 return;
2168         }
2169
2170         if (time_before_eq(last_recv + recv_timeout, jiffies)) {
2171                 /* send a ping to try to provoke some traffic */
2172                 ISCSI_DBG_CONN(conn, "Sending nopout as ping\n");
2173                 if (iscsi_send_nopout(conn, NULL))
2174                         next_timeout = jiffies + (1 * HZ);
2175                 else
2176                         next_timeout = conn->last_ping + (conn->ping_timeout * HZ);
2177         } else
2178                 next_timeout = last_recv + recv_timeout;
2179
2180         ISCSI_DBG_CONN(conn, "Setting next tmo %lu\n", next_timeout);
2181         mod_timer(&conn->transport_timer, next_timeout);
2182 done:
2183         spin_unlock(&session->frwd_lock);
2184 }
2185
2186 /**
2187  * iscsi_conn_unbind - prevent queueing to conn.
2188  * @cls_conn: iscsi conn ep is bound to.
2189  * @is_active: is the conn in use for boot or is this for EH/termination
2190  *
2191  * This must be called by drivers implementing the ep_disconnect callout.
2192  * It disables queueing to the connection from libiscsi in preparation for
2193  * an ep_disconnect call.
2194  */
2195 void iscsi_conn_unbind(struct iscsi_cls_conn *cls_conn, bool is_active)
2196 {
2197         struct iscsi_session *session;
2198         struct iscsi_conn *conn;
2199
2200         if (!cls_conn)
2201                 return;
2202
2203         conn = cls_conn->dd_data;
2204         session = conn->session;
2205         /*
2206          * Wait for iscsi_eh calls to exit. We don't wait for the tmf to
2207          * complete or timeout. The caller just wants to know what's running
2208          * is everything that needs to be cleaned up, and no cmds will be
2209          * queued.
2210          */
2211         mutex_lock(&session->eh_mutex);
2212
2213         iscsi_suspend_queue(conn);
2214         iscsi_suspend_tx(conn);
2215
2216         spin_lock_bh(&session->frwd_lock);
2217         if (!is_active) {
2218                 /*
2219                  * if logout timed out before userspace could even send a PDU
2220                  * the state might still be in ISCSI_STATE_LOGGED_IN and
2221                  * allowing new cmds and TMFs.
2222                  */
2223                 if (session->state == ISCSI_STATE_LOGGED_IN)
2224                         iscsi_set_conn_failed(conn);
2225         }
2226         spin_unlock_bh(&session->frwd_lock);
2227         mutex_unlock(&session->eh_mutex);
2228 }
2229 EXPORT_SYMBOL_GPL(iscsi_conn_unbind);
2230
2231 static void iscsi_prep_abort_task_pdu(struct iscsi_task *task,
2232                                       struct iscsi_tm *hdr)
2233 {
2234         memset(hdr, 0, sizeof(*hdr));
2235         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2236         hdr->flags = ISCSI_TM_FUNC_ABORT_TASK & ISCSI_FLAG_TM_FUNC_MASK;
2237         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2238         hdr->lun = task->lun;
2239         hdr->rtt = task->hdr_itt;
2240         hdr->refcmdsn = task->cmdsn;
2241 }
2242
2243 int iscsi_eh_abort(struct scsi_cmnd *sc)
2244 {
2245         struct iscsi_cls_session *cls_session;
2246         struct iscsi_session *session;
2247         struct iscsi_conn *conn;
2248         struct iscsi_task *task;
2249         struct iscsi_tm *hdr;
2250         int age;
2251
2252         cls_session = starget_to_session(scsi_target(sc->device));
2253         session = cls_session->dd_data;
2254
2255         ISCSI_DBG_EH(session, "aborting sc %p\n", sc);
2256
2257         mutex_lock(&session->eh_mutex);
2258         spin_lock_bh(&session->frwd_lock);
2259         /*
2260          * if session was ISCSI_STATE_IN_RECOVERY then we may not have
2261          * got the command.
2262          */
2263         if (!sc->SCp.ptr) {
2264                 ISCSI_DBG_EH(session, "sc never reached iscsi layer or "
2265                                       "it completed.\n");
2266                 spin_unlock_bh(&session->frwd_lock);
2267                 mutex_unlock(&session->eh_mutex);
2268                 return SUCCESS;
2269         }
2270
2271         /*
2272          * If we are not logged in or we have started a new session
2273          * then let the host reset code handle this
2274          */
2275         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN ||
2276             sc->SCp.phase != session->age) {
2277                 spin_unlock_bh(&session->frwd_lock);
2278                 mutex_unlock(&session->eh_mutex);
2279                 ISCSI_DBG_EH(session, "failing abort due to dropped "
2280                                   "session.\n");
2281                 return FAILED;
2282         }
2283
2284         spin_lock(&session->back_lock);
2285         task = (struct iscsi_task *)sc->SCp.ptr;
2286         if (!task || !task->sc) {
2287                 /* task completed before time out */
2288                 ISCSI_DBG_EH(session, "sc completed while abort in progress\n");
2289
2290                 spin_unlock(&session->back_lock);
2291                 spin_unlock_bh(&session->frwd_lock);
2292                 mutex_unlock(&session->eh_mutex);
2293                 return SUCCESS;
2294         }
2295
2296         conn = session->leadconn;
2297         iscsi_get_conn(conn->cls_conn);
2298         conn->eh_abort_cnt++;
2299         age = session->age;
2300
2301         ISCSI_DBG_EH(session, "aborting [sc %p itt 0x%x]\n", sc, task->itt);
2302         __iscsi_get_task(task);
2303         spin_unlock(&session->back_lock);
2304
2305         if (task->state == ISCSI_TASK_PENDING) {
2306                 fail_scsi_task(task, DID_ABORT);
2307                 goto success;
2308         }
2309
2310         /* only have one tmf outstanding at a time */
2311         if (session->tmf_state != TMF_INITIAL)
2312                 goto failed;
2313         session->tmf_state = TMF_QUEUED;
2314
2315         hdr = &session->tmhdr;
2316         iscsi_prep_abort_task_pdu(task, hdr);
2317
2318         if (iscsi_exec_task_mgmt_fn(conn, hdr, age, session->abort_timeout))
2319                 goto failed;
2320
2321         switch (session->tmf_state) {
2322         case TMF_SUCCESS:
2323                 spin_unlock_bh(&session->frwd_lock);
2324                 /*
2325                  * stop tx side incase the target had sent a abort rsp but
2326                  * the initiator was still writing out data.
2327                  */
2328                 iscsi_suspend_tx(conn);
2329                 /*
2330                  * we do not stop the recv side because targets have been
2331                  * good and have never sent us a successful tmf response
2332                  * then sent more data for the cmd.
2333                  */
2334                 spin_lock_bh(&session->frwd_lock);
2335                 fail_scsi_task(task, DID_ABORT);
2336                 session->tmf_state = TMF_INITIAL;
2337                 memset(hdr, 0, sizeof(*hdr));
2338                 spin_unlock_bh(&session->frwd_lock);
2339                 iscsi_start_tx(conn);
2340                 goto success_unlocked;
2341         case TMF_TIMEDOUT:
2342                 session->running_aborted_task = task;
2343                 spin_unlock_bh(&session->frwd_lock);
2344                 iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2345                 goto failed_unlocked;
2346         case TMF_NOT_FOUND:
2347                 if (iscsi_task_is_completed(task)) {
2348                         session->tmf_state = TMF_INITIAL;
2349                         memset(hdr, 0, sizeof(*hdr));
2350                         /* task completed before tmf abort response */
2351                         ISCSI_DBG_EH(session, "sc completed while abort in "
2352                                               "progress\n");
2353                         goto success;
2354                 }
2355                 fallthrough;
2356         default:
2357                 session->tmf_state = TMF_INITIAL;
2358                 goto failed;
2359         }
2360
2361 success:
2362         spin_unlock_bh(&session->frwd_lock);
2363 success_unlocked:
2364         ISCSI_DBG_EH(session, "abort success [sc %p itt 0x%x]\n",
2365                      sc, task->itt);
2366         iscsi_put_task(task);
2367         iscsi_put_conn(conn->cls_conn);
2368         mutex_unlock(&session->eh_mutex);
2369         return SUCCESS;
2370
2371 failed:
2372         spin_unlock_bh(&session->frwd_lock);
2373 failed_unlocked:
2374         ISCSI_DBG_EH(session, "abort failed [sc %p itt 0x%x]\n", sc,
2375                      task ? task->itt : 0);
2376         /*
2377          * The driver might be accessing the task so hold the ref. The conn
2378          * stop cleanup will drop the ref after ep_disconnect so we know the
2379          * driver's no longer touching the task.
2380          */
2381         if (!session->running_aborted_task)
2382                 iscsi_put_task(task);
2383
2384         iscsi_put_conn(conn->cls_conn);
2385         mutex_unlock(&session->eh_mutex);
2386         return FAILED;
2387 }
2388 EXPORT_SYMBOL_GPL(iscsi_eh_abort);
2389
2390 static void iscsi_prep_lun_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
2391 {
2392         memset(hdr, 0, sizeof(*hdr));
2393         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2394         hdr->flags = ISCSI_TM_FUNC_LOGICAL_UNIT_RESET & ISCSI_FLAG_TM_FUNC_MASK;
2395         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2396         int_to_scsilun(sc->device->lun, &hdr->lun);
2397         hdr->rtt = RESERVED_ITT;
2398 }
2399
2400 int iscsi_eh_device_reset(struct scsi_cmnd *sc)
2401 {
2402         struct iscsi_cls_session *cls_session;
2403         struct iscsi_session *session;
2404         struct iscsi_conn *conn;
2405         struct iscsi_tm *hdr;
2406         int rc = FAILED;
2407
2408         cls_session = starget_to_session(scsi_target(sc->device));
2409         session = cls_session->dd_data;
2410
2411         ISCSI_DBG_EH(session, "LU Reset [sc %p lun %llu]\n", sc,
2412                      sc->device->lun);
2413
2414         mutex_lock(&session->eh_mutex);
2415         spin_lock_bh(&session->frwd_lock);
2416         /*
2417          * Just check if we are not logged in. We cannot check for
2418          * the phase because the reset could come from a ioctl.
2419          */
2420         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
2421                 goto unlock;
2422         conn = session->leadconn;
2423
2424         /* only have one tmf outstanding at a time */
2425         if (session->tmf_state != TMF_INITIAL)
2426                 goto unlock;
2427         session->tmf_state = TMF_QUEUED;
2428
2429         hdr = &session->tmhdr;
2430         iscsi_prep_lun_reset_pdu(sc, hdr);
2431
2432         if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
2433                                     session->lu_reset_timeout)) {
2434                 rc = FAILED;
2435                 goto unlock;
2436         }
2437
2438         switch (session->tmf_state) {
2439         case TMF_SUCCESS:
2440                 break;
2441         case TMF_TIMEDOUT:
2442                 spin_unlock_bh(&session->frwd_lock);
2443                 iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2444                 goto done;
2445         default:
2446                 session->tmf_state = TMF_INITIAL;
2447                 goto unlock;
2448         }
2449
2450         rc = SUCCESS;
2451         spin_unlock_bh(&session->frwd_lock);
2452
2453         iscsi_suspend_tx(conn);
2454
2455         spin_lock_bh(&session->frwd_lock);
2456         memset(hdr, 0, sizeof(*hdr));
2457         fail_scsi_tasks(conn, sc->device->lun, DID_ERROR);
2458         session->tmf_state = TMF_INITIAL;
2459         spin_unlock_bh(&session->frwd_lock);
2460
2461         iscsi_start_tx(conn);
2462         goto done;
2463
2464 unlock:
2465         spin_unlock_bh(&session->frwd_lock);
2466 done:
2467         ISCSI_DBG_EH(session, "dev reset result = %s\n",
2468                      rc == SUCCESS ? "SUCCESS" : "FAILED");
2469         mutex_unlock(&session->eh_mutex);
2470         return rc;
2471 }
2472 EXPORT_SYMBOL_GPL(iscsi_eh_device_reset);
2473
2474 void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
2475 {
2476         struct iscsi_session *session = cls_session->dd_data;
2477
2478         spin_lock_bh(&session->frwd_lock);
2479         if (session->state != ISCSI_STATE_LOGGED_IN) {
2480                 session->state = ISCSI_STATE_RECOVERY_FAILED;
2481                 wake_up(&session->ehwait);
2482         }
2483         spin_unlock_bh(&session->frwd_lock);
2484 }
2485 EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
2486
2487 /**
2488  * iscsi_eh_session_reset - drop session and attempt relogin
2489  * @sc: scsi command
2490  *
2491  * This function will wait for a relogin, session termination from
2492  * userspace, or a recovery/replacement timeout.
2493  */
2494 int iscsi_eh_session_reset(struct scsi_cmnd *sc)
2495 {
2496         struct iscsi_cls_session *cls_session;
2497         struct iscsi_session *session;
2498         struct iscsi_conn *conn;
2499
2500         cls_session = starget_to_session(scsi_target(sc->device));
2501         session = cls_session->dd_data;
2502
2503         mutex_lock(&session->eh_mutex);
2504         spin_lock_bh(&session->frwd_lock);
2505         if (session->state == ISCSI_STATE_TERMINATE) {
2506 failed:
2507                 ISCSI_DBG_EH(session,
2508                              "failing session reset: Could not log back into "
2509                              "%s [age %d]\n", session->targetname,
2510                              session->age);
2511                 spin_unlock_bh(&session->frwd_lock);
2512                 mutex_unlock(&session->eh_mutex);
2513                 return FAILED;
2514         }
2515
2516         conn = session->leadconn;
2517         iscsi_get_conn(conn->cls_conn);
2518
2519         spin_unlock_bh(&session->frwd_lock);
2520         mutex_unlock(&session->eh_mutex);
2521
2522         iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2523         iscsi_put_conn(conn->cls_conn);
2524
2525         ISCSI_DBG_EH(session, "wait for relogin\n");
2526         wait_event_interruptible(session->ehwait,
2527                                  session->state == ISCSI_STATE_TERMINATE ||
2528                                  session->state == ISCSI_STATE_LOGGED_IN ||
2529                                  session->state == ISCSI_STATE_RECOVERY_FAILED);
2530         if (signal_pending(current))
2531                 flush_signals(current);
2532
2533         mutex_lock(&session->eh_mutex);
2534         spin_lock_bh(&session->frwd_lock);
2535         if (session->state == ISCSI_STATE_LOGGED_IN) {
2536                 ISCSI_DBG_EH(session,
2537                              "session reset succeeded for %s,%s\n",
2538                              session->targetname, conn->persistent_address);
2539         } else
2540                 goto failed;
2541         spin_unlock_bh(&session->frwd_lock);
2542         mutex_unlock(&session->eh_mutex);
2543         return SUCCESS;
2544 }
2545 EXPORT_SYMBOL_GPL(iscsi_eh_session_reset);
2546
2547 static void iscsi_prep_tgt_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
2548 {
2549         memset(hdr, 0, sizeof(*hdr));
2550         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2551         hdr->flags = ISCSI_TM_FUNC_TARGET_WARM_RESET & ISCSI_FLAG_TM_FUNC_MASK;
2552         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2553         hdr->rtt = RESERVED_ITT;
2554 }
2555
2556 /**
2557  * iscsi_eh_target_reset - reset target
2558  * @sc: scsi command
2559  *
2560  * This will attempt to send a warm target reset.
2561  */
2562 static int iscsi_eh_target_reset(struct scsi_cmnd *sc)
2563 {
2564         struct iscsi_cls_session *cls_session;
2565         struct iscsi_session *session;
2566         struct iscsi_conn *conn;
2567         struct iscsi_tm *hdr;
2568         int rc = FAILED;
2569
2570         cls_session = starget_to_session(scsi_target(sc->device));
2571         session = cls_session->dd_data;
2572
2573         ISCSI_DBG_EH(session, "tgt Reset [sc %p tgt %s]\n", sc,
2574                      session->targetname);
2575
2576         mutex_lock(&session->eh_mutex);
2577         spin_lock_bh(&session->frwd_lock);
2578         /*
2579          * Just check if we are not logged in. We cannot check for
2580          * the phase because the reset could come from a ioctl.
2581          */
2582         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
2583                 goto unlock;
2584         conn = session->leadconn;
2585
2586         /* only have one tmf outstanding at a time */
2587         if (session->tmf_state != TMF_INITIAL)
2588                 goto unlock;
2589         session->tmf_state = TMF_QUEUED;
2590
2591         hdr = &session->tmhdr;
2592         iscsi_prep_tgt_reset_pdu(sc, hdr);
2593
2594         if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
2595                                     session->tgt_reset_timeout)) {
2596                 rc = FAILED;
2597                 goto unlock;
2598         }
2599
2600         switch (session->tmf_state) {
2601         case TMF_SUCCESS:
2602                 break;
2603         case TMF_TIMEDOUT:
2604                 spin_unlock_bh(&session->frwd_lock);
2605                 iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2606                 goto done;
2607         default:
2608                 session->tmf_state = TMF_INITIAL;
2609                 goto unlock;
2610         }
2611
2612         rc = SUCCESS;
2613         spin_unlock_bh(&session->frwd_lock);
2614
2615         iscsi_suspend_tx(conn);
2616
2617         spin_lock_bh(&session->frwd_lock);
2618         memset(hdr, 0, sizeof(*hdr));
2619         fail_scsi_tasks(conn, -1, DID_ERROR);
2620         session->tmf_state = TMF_INITIAL;
2621         spin_unlock_bh(&session->frwd_lock);
2622
2623         iscsi_start_tx(conn);
2624         goto done;
2625
2626 unlock:
2627         spin_unlock_bh(&session->frwd_lock);
2628 done:
2629         ISCSI_DBG_EH(session, "tgt %s reset result = %s\n", session->targetname,
2630                      rc == SUCCESS ? "SUCCESS" : "FAILED");
2631         mutex_unlock(&session->eh_mutex);
2632         return rc;
2633 }
2634
2635 /**
2636  * iscsi_eh_recover_target - reset target and possibly the session
2637  * @sc: scsi command
2638  *
2639  * This will attempt to send a warm target reset. If that fails,
2640  * we will escalate to ERL0 session recovery.
2641  */
2642 int iscsi_eh_recover_target(struct scsi_cmnd *sc)
2643 {
2644         int rc;
2645
2646         rc = iscsi_eh_target_reset(sc);
2647         if (rc == FAILED)
2648                 rc = iscsi_eh_session_reset(sc);
2649         return rc;
2650 }
2651 EXPORT_SYMBOL_GPL(iscsi_eh_recover_target);
2652
2653 /*
2654  * Pre-allocate a pool of @max items of @item_size. By default, the pool
2655  * should be accessed via kfifo_{get,put} on q->queue.
2656  * Optionally, the caller can obtain the array of object pointers
2657  * by passing in a non-NULL @items pointer
2658  */
2659 int
2660 iscsi_pool_init(struct iscsi_pool *q, int max, void ***items, int item_size)
2661 {
2662         int i, num_arrays = 1;
2663
2664         memset(q, 0, sizeof(*q));
2665
2666         q->max = max;
2667
2668         /* If the user passed an items pointer, he wants a copy of
2669          * the array. */
2670         if (items)
2671                 num_arrays++;
2672         q->pool = kvcalloc(num_arrays * max, sizeof(void *), GFP_KERNEL);
2673         if (q->pool == NULL)
2674                 return -ENOMEM;
2675
2676         kfifo_init(&q->queue, (void*)q->pool, max * sizeof(void*));
2677
2678         for (i = 0; i < max; i++) {
2679                 q->pool[i] = kzalloc(item_size, GFP_KERNEL);
2680                 if (q->pool[i] == NULL) {
2681                         q->max = i;
2682                         goto enomem;
2683                 }
2684                 kfifo_in(&q->queue, (void*)&q->pool[i], sizeof(void*));
2685         }
2686
2687         if (items) {
2688                 *items = q->pool + max;
2689                 memcpy(*items, q->pool, max * sizeof(void *));
2690         }
2691
2692         return 0;
2693
2694 enomem:
2695         iscsi_pool_free(q);
2696         return -ENOMEM;
2697 }
2698 EXPORT_SYMBOL_GPL(iscsi_pool_init);
2699
2700 void iscsi_pool_free(struct iscsi_pool *q)
2701 {
2702         int i;
2703
2704         for (i = 0; i < q->max; i++)
2705                 kfree(q->pool[i]);
2706         kvfree(q->pool);
2707 }
2708 EXPORT_SYMBOL_GPL(iscsi_pool_free);
2709
2710 int iscsi_host_get_max_scsi_cmds(struct Scsi_Host *shost,
2711                                  uint16_t requested_cmds_max)
2712 {
2713         int scsi_cmds, total_cmds = requested_cmds_max;
2714
2715 check:
2716         if (!total_cmds)
2717                 total_cmds = ISCSI_DEF_XMIT_CMDS_MAX;
2718         /*
2719          * The iscsi layer needs some tasks for nop handling and tmfs,
2720          * so the cmds_max must at least be greater than ISCSI_MGMT_CMDS_MAX
2721          * + 1 command for scsi IO.
2722          */
2723         if (total_cmds < ISCSI_TOTAL_CMDS_MIN) {
2724                 printk(KERN_ERR "iscsi: invalid max cmds of %d. Must be a power of two that is at least %d.\n",
2725                        total_cmds, ISCSI_TOTAL_CMDS_MIN);
2726                 return -EINVAL;
2727         }
2728
2729         if (total_cmds > ISCSI_TOTAL_CMDS_MAX) {
2730                 printk(KERN_INFO "iscsi: invalid max cmds of %d. Must be a power of 2 less than or equal to %d. Using %d.\n",
2731                        requested_cmds_max, ISCSI_TOTAL_CMDS_MAX,
2732                        ISCSI_TOTAL_CMDS_MAX);
2733                 total_cmds = ISCSI_TOTAL_CMDS_MAX;
2734         }
2735
2736         if (!is_power_of_2(total_cmds)) {
2737                 total_cmds = rounddown_pow_of_two(total_cmds);
2738                 if (total_cmds < ISCSI_TOTAL_CMDS_MIN) {
2739                         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);
2740                         return -EINVAL;
2741                 }
2742
2743                 printk(KERN_INFO "iscsi: invalid max cmds %d. Must be a power of 2. Rounding max cmds down to %d.\n",
2744                        requested_cmds_max, total_cmds);
2745         }
2746
2747         scsi_cmds = total_cmds - ISCSI_MGMT_CMDS_MAX;
2748         if (shost->can_queue && scsi_cmds > shost->can_queue) {
2749                 total_cmds = shost->can_queue;
2750
2751                 printk(KERN_INFO "iscsi: requested max cmds %u is higher than driver limit. Using driver limit %u\n",
2752                        requested_cmds_max, shost->can_queue);
2753                 goto check;
2754         }
2755
2756         return scsi_cmds;
2757 }
2758 EXPORT_SYMBOL_GPL(iscsi_host_get_max_scsi_cmds);
2759
2760 /**
2761  * iscsi_host_add - add host to system
2762  * @shost: scsi host
2763  * @pdev: parent device
2764  *
2765  * This should be called by partial offload and software iscsi drivers
2766  * to add a host to the system.
2767  */
2768 int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev)
2769 {
2770         if (!shost->can_queue)
2771                 shost->can_queue = ISCSI_DEF_XMIT_CMDS_MAX;
2772
2773         if (!shost->cmd_per_lun)
2774                 shost->cmd_per_lun = ISCSI_DEF_CMD_PER_LUN;
2775
2776         return scsi_add_host(shost, pdev);
2777 }
2778 EXPORT_SYMBOL_GPL(iscsi_host_add);
2779
2780 /**
2781  * iscsi_host_alloc - allocate a host and driver data
2782  * @sht: scsi host template
2783  * @dd_data_size: driver host data size
2784  * @xmit_can_sleep: bool indicating if LLD will queue IO from a work queue
2785  *
2786  * This should be called by partial offload and software iscsi drivers.
2787  * To access the driver specific memory use the iscsi_host_priv() macro.
2788  */
2789 struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
2790                                    int dd_data_size, bool xmit_can_sleep)
2791 {
2792         struct Scsi_Host *shost;
2793         struct iscsi_host *ihost;
2794
2795         shost = scsi_host_alloc(sht, sizeof(struct iscsi_host) + dd_data_size);
2796         if (!shost)
2797                 return NULL;
2798         ihost = shost_priv(shost);
2799
2800         if (xmit_can_sleep) {
2801                 snprintf(ihost->workq_name, sizeof(ihost->workq_name),
2802                         "iscsi_q_%d", shost->host_no);
2803                 ihost->workq = alloc_workqueue("%s",
2804                         WQ_SYSFS | __WQ_LEGACY | WQ_MEM_RECLAIM | WQ_UNBOUND,
2805                         1, ihost->workq_name);
2806                 if (!ihost->workq)
2807                         goto free_host;
2808         }
2809
2810         spin_lock_init(&ihost->lock);
2811         ihost->state = ISCSI_HOST_SETUP;
2812         ihost->num_sessions = 0;
2813         init_waitqueue_head(&ihost->session_removal_wq);
2814         return shost;
2815
2816 free_host:
2817         scsi_host_put(shost);
2818         return NULL;
2819 }
2820 EXPORT_SYMBOL_GPL(iscsi_host_alloc);
2821
2822 static void iscsi_notify_host_removed(struct iscsi_cls_session *cls_session)
2823 {
2824         iscsi_session_failure(cls_session->dd_data, ISCSI_ERR_INVALID_HOST);
2825 }
2826
2827 /**
2828  * iscsi_host_remove - remove host and sessions
2829  * @shost: scsi host
2830  *
2831  * If there are any sessions left, this will initiate the removal and wait
2832  * for the completion.
2833  */
2834 void iscsi_host_remove(struct Scsi_Host *shost)
2835 {
2836         struct iscsi_host *ihost = shost_priv(shost);
2837         unsigned long flags;
2838
2839         spin_lock_irqsave(&ihost->lock, flags);
2840         ihost->state = ISCSI_HOST_REMOVED;
2841         spin_unlock_irqrestore(&ihost->lock, flags);
2842
2843         iscsi_host_for_each_session(shost, iscsi_notify_host_removed);
2844         wait_event_interruptible(ihost->session_removal_wq,
2845                                  ihost->num_sessions == 0);
2846         if (signal_pending(current))
2847                 flush_signals(current);
2848
2849         scsi_remove_host(shost);
2850 }
2851 EXPORT_SYMBOL_GPL(iscsi_host_remove);
2852
2853 void iscsi_host_free(struct Scsi_Host *shost)
2854 {
2855         struct iscsi_host *ihost = shost_priv(shost);
2856
2857         if (ihost->workq)
2858                 destroy_workqueue(ihost->workq);
2859
2860         kfree(ihost->netdev);
2861         kfree(ihost->hwaddress);
2862         kfree(ihost->initiatorname);
2863         scsi_host_put(shost);
2864 }
2865 EXPORT_SYMBOL_GPL(iscsi_host_free);
2866
2867 static void iscsi_host_dec_session_cnt(struct Scsi_Host *shost)
2868 {
2869         struct iscsi_host *ihost = shost_priv(shost);
2870         unsigned long flags;
2871
2872         shost = scsi_host_get(shost);
2873         if (!shost) {
2874                 printk(KERN_ERR "Invalid state. Cannot notify host removal "
2875                       "of session teardown event because host already "
2876                       "removed.\n");
2877                 return;
2878         }
2879
2880         spin_lock_irqsave(&ihost->lock, flags);
2881         ihost->num_sessions--;
2882         if (ihost->num_sessions == 0)
2883                 wake_up(&ihost->session_removal_wq);
2884         spin_unlock_irqrestore(&ihost->lock, flags);
2885         scsi_host_put(shost);
2886 }
2887
2888 /**
2889  * iscsi_session_setup - create iscsi cls session and host and session
2890  * @iscsit: iscsi transport template
2891  * @shost: scsi host
2892  * @cmds_max: session can queue
2893  * @dd_size: private driver data size, added to session allocation size
2894  * @cmd_task_size: LLD task private data size
2895  * @initial_cmdsn: initial CmdSN
2896  * @id: target ID to add to this session
2897  *
2898  * This can be used by software iscsi_transports that allocate
2899  * a session per scsi host.
2900  *
2901  * Callers should set cmds_max to the largest total numer (mgmt + scsi) of
2902  * tasks they support. The iscsi layer reserves ISCSI_MGMT_CMDS_MAX tasks
2903  * for nop handling and login/logout requests.
2904  */
2905 struct iscsi_cls_session *
2906 iscsi_session_setup(struct iscsi_transport *iscsit, struct Scsi_Host *shost,
2907                     uint16_t cmds_max, int dd_size, int cmd_task_size,
2908                     uint32_t initial_cmdsn, unsigned int id)
2909 {
2910         struct iscsi_host *ihost = shost_priv(shost);
2911         struct iscsi_session *session;
2912         struct iscsi_cls_session *cls_session;
2913         int cmd_i, scsi_cmds;
2914         unsigned long flags;
2915
2916         spin_lock_irqsave(&ihost->lock, flags);
2917         if (ihost->state == ISCSI_HOST_REMOVED) {
2918                 spin_unlock_irqrestore(&ihost->lock, flags);
2919                 return NULL;
2920         }
2921         ihost->num_sessions++;
2922         spin_unlock_irqrestore(&ihost->lock, flags);
2923
2924         scsi_cmds = iscsi_host_get_max_scsi_cmds(shost, cmds_max);
2925         if (scsi_cmds < 0)
2926                 goto dec_session_count;
2927
2928         cls_session = iscsi_alloc_session(shost, iscsit,
2929                                           sizeof(struct iscsi_session) +
2930                                           dd_size);
2931         if (!cls_session)
2932                 goto dec_session_count;
2933         session = cls_session->dd_data;
2934         session->cls_session = cls_session;
2935         session->host = shost;
2936         session->state = ISCSI_STATE_FREE;
2937         session->fast_abort = 1;
2938         session->tgt_reset_timeout = 30;
2939         session->lu_reset_timeout = 15;
2940         session->abort_timeout = 10;
2941         session->scsi_cmds_max = scsi_cmds;
2942         session->cmds_max = scsi_cmds + ISCSI_MGMT_CMDS_MAX;
2943         session->queued_cmdsn = session->cmdsn = initial_cmdsn;
2944         session->exp_cmdsn = initial_cmdsn + 1;
2945         session->max_cmdsn = initial_cmdsn + 1;
2946         session->max_r2t = 1;
2947         session->tt = iscsit;
2948         session->dd_data = cls_session->dd_data + sizeof(*session);
2949
2950         session->tmf_state = TMF_INITIAL;
2951         timer_setup(&session->tmf_timer, iscsi_tmf_timedout, 0);
2952         mutex_init(&session->eh_mutex);
2953
2954         spin_lock_init(&session->frwd_lock);
2955         spin_lock_init(&session->back_lock);
2956
2957         /* initialize SCSI PDU commands pool */
2958         if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
2959                             (void***)&session->cmds,
2960                             cmd_task_size + sizeof(struct iscsi_task)))
2961                 goto cmdpool_alloc_fail;
2962
2963         /* pre-format cmds pool with ITT */
2964         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
2965                 struct iscsi_task *task = session->cmds[cmd_i];
2966
2967                 if (cmd_task_size)
2968                         task->dd_data = &task[1];
2969                 task->itt = cmd_i;
2970                 task->state = ISCSI_TASK_FREE;
2971                 INIT_LIST_HEAD(&task->running);
2972         }
2973
2974         if (!try_module_get(iscsit->owner))
2975                 goto module_get_fail;
2976
2977         if (iscsi_add_session(cls_session, id))
2978                 goto cls_session_fail;
2979
2980         return cls_session;
2981
2982 cls_session_fail:
2983         module_put(iscsit->owner);
2984 module_get_fail:
2985         iscsi_pool_free(&session->cmdpool);
2986 cmdpool_alloc_fail:
2987         iscsi_free_session(cls_session);
2988 dec_session_count:
2989         iscsi_host_dec_session_cnt(shost);
2990         return NULL;
2991 }
2992 EXPORT_SYMBOL_GPL(iscsi_session_setup);
2993
2994 /**
2995  * iscsi_session_teardown - destroy session, host, and cls_session
2996  * @cls_session: iscsi session
2997  */
2998 void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
2999 {
3000         struct iscsi_session *session = cls_session->dd_data;
3001         struct module *owner = cls_session->transport->owner;
3002         struct Scsi_Host *shost = session->host;
3003
3004         iscsi_remove_session(cls_session);
3005
3006         iscsi_pool_free(&session->cmdpool);
3007         kfree(session->password);
3008         kfree(session->password_in);
3009         kfree(session->username);
3010         kfree(session->username_in);
3011         kfree(session->targetname);
3012         kfree(session->targetalias);
3013         kfree(session->initiatorname);
3014         kfree(session->boot_root);
3015         kfree(session->boot_nic);
3016         kfree(session->boot_target);
3017         kfree(session->ifacename);
3018         kfree(session->portal_type);
3019         kfree(session->discovery_parent_type);
3020
3021         iscsi_free_session(cls_session);
3022
3023         iscsi_host_dec_session_cnt(shost);
3024         module_put(owner);
3025 }
3026 EXPORT_SYMBOL_GPL(iscsi_session_teardown);
3027
3028 /**
3029  * iscsi_conn_setup - create iscsi_cls_conn and iscsi_conn
3030  * @cls_session: iscsi_cls_session
3031  * @dd_size: private driver data size
3032  * @conn_idx: cid
3033  */
3034 struct iscsi_cls_conn *
3035 iscsi_conn_setup(struct iscsi_cls_session *cls_session, int dd_size,
3036                  uint32_t conn_idx)
3037 {
3038         struct iscsi_session *session = cls_session->dd_data;
3039         struct iscsi_conn *conn;
3040         struct iscsi_cls_conn *cls_conn;
3041         char *data;
3042
3043         cls_conn = iscsi_create_conn(cls_session, sizeof(*conn) + dd_size,
3044                                      conn_idx);
3045         if (!cls_conn)
3046                 return NULL;
3047         conn = cls_conn->dd_data;
3048         memset(conn, 0, sizeof(*conn) + dd_size);
3049
3050         conn->dd_data = cls_conn->dd_data + sizeof(*conn);
3051         conn->session = session;
3052         conn->cls_conn = cls_conn;
3053         conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
3054         conn->id = conn_idx;
3055         conn->exp_statsn = 0;
3056
3057         timer_setup(&conn->transport_timer, iscsi_check_transport_timeouts, 0);
3058
3059         INIT_LIST_HEAD(&conn->mgmtqueue);
3060         INIT_LIST_HEAD(&conn->cmdqueue);
3061         INIT_LIST_HEAD(&conn->requeue);
3062         INIT_WORK(&conn->xmitwork, iscsi_xmitworker);
3063
3064         /* allocate login_task used for the login/text sequences */
3065         spin_lock_bh(&session->frwd_lock);
3066         if (!kfifo_out(&session->cmdpool.queue,
3067                          (void*)&conn->login_task,
3068                          sizeof(void*))) {
3069                 spin_unlock_bh(&session->frwd_lock);
3070                 goto login_task_alloc_fail;
3071         }
3072         spin_unlock_bh(&session->frwd_lock);
3073
3074         data = (char *) __get_free_pages(GFP_KERNEL,
3075                                          get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
3076         if (!data)
3077                 goto login_task_data_alloc_fail;
3078         conn->login_task->data = conn->data = data;
3079
3080         init_waitqueue_head(&session->ehwait);
3081
3082         return cls_conn;
3083
3084 login_task_data_alloc_fail:
3085         kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
3086                     sizeof(void*));
3087 login_task_alloc_fail:
3088         iscsi_destroy_conn(cls_conn);
3089         return NULL;
3090 }
3091 EXPORT_SYMBOL_GPL(iscsi_conn_setup);
3092
3093 /**
3094  * iscsi_conn_teardown - teardown iscsi connection
3095  * @cls_conn: iscsi class connection
3096  *
3097  * TODO: we may need to make this into a two step process
3098  * like scsi-mls remove + put host
3099  */
3100 void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
3101 {
3102         struct iscsi_conn *conn = cls_conn->dd_data;
3103         struct iscsi_session *session = conn->session;
3104
3105         del_timer_sync(&conn->transport_timer);
3106
3107         mutex_lock(&session->eh_mutex);
3108         spin_lock_bh(&session->frwd_lock);
3109         conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
3110         if (session->leadconn == conn) {
3111                 /*
3112                  * leading connection? then give up on recovery.
3113                  */
3114                 session->state = ISCSI_STATE_TERMINATE;
3115                 wake_up(&session->ehwait);
3116         }
3117         spin_unlock_bh(&session->frwd_lock);
3118
3119         /* flush queued up work because we free the connection below */
3120         iscsi_suspend_tx(conn);
3121
3122         spin_lock_bh(&session->frwd_lock);
3123         free_pages((unsigned long) conn->data,
3124                    get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
3125         kfree(conn->persistent_address);
3126         kfree(conn->local_ipaddr);
3127         /* regular RX path uses back_lock */
3128         spin_lock_bh(&session->back_lock);
3129         kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
3130                     sizeof(void*));
3131         spin_unlock_bh(&session->back_lock);
3132         if (session->leadconn == conn)
3133                 session->leadconn = NULL;
3134         spin_unlock_bh(&session->frwd_lock);
3135         mutex_unlock(&session->eh_mutex);
3136
3137         iscsi_destroy_conn(cls_conn);
3138 }
3139 EXPORT_SYMBOL_GPL(iscsi_conn_teardown);
3140
3141 int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
3142 {
3143         struct iscsi_conn *conn = cls_conn->dd_data;
3144         struct iscsi_session *session = conn->session;
3145
3146         if (!session) {
3147                 iscsi_conn_printk(KERN_ERR, conn,
3148                                   "can't start unbound connection\n");
3149                 return -EPERM;
3150         }
3151
3152         if ((session->imm_data_en || !session->initial_r2t_en) &&
3153              session->first_burst > session->max_burst) {
3154                 iscsi_conn_printk(KERN_INFO, conn, "invalid burst lengths: "
3155                                   "first_burst %d max_burst %d\n",
3156                                   session->first_burst, session->max_burst);
3157                 return -EINVAL;
3158         }
3159
3160         if (conn->ping_timeout && !conn->recv_timeout) {
3161                 iscsi_conn_printk(KERN_ERR, conn, "invalid recv timeout of "
3162                                   "zero. Using 5 seconds\n.");
3163                 conn->recv_timeout = 5;
3164         }
3165
3166         if (conn->recv_timeout && !conn->ping_timeout) {
3167                 iscsi_conn_printk(KERN_ERR, conn, "invalid ping timeout of "
3168                                   "zero. Using 5 seconds.\n");
3169                 conn->ping_timeout = 5;
3170         }
3171
3172         spin_lock_bh(&session->frwd_lock);
3173         conn->c_stage = ISCSI_CONN_STARTED;
3174         session->state = ISCSI_STATE_LOGGED_IN;
3175         session->queued_cmdsn = session->cmdsn;
3176
3177         conn->last_recv = jiffies;
3178         conn->last_ping = jiffies;
3179         if (conn->recv_timeout && conn->ping_timeout)
3180                 mod_timer(&conn->transport_timer,
3181                           jiffies + (conn->recv_timeout * HZ));
3182
3183         switch(conn->stop_stage) {
3184         case STOP_CONN_RECOVER:
3185                 /*
3186                  * unblock eh_abort() if it is blocked. re-try all
3187                  * commands after successful recovery
3188                  */
3189                 conn->stop_stage = 0;
3190                 session->tmf_state = TMF_INITIAL;
3191                 session->age++;
3192                 if (session->age == 16)
3193                         session->age = 0;
3194                 break;
3195         case STOP_CONN_TERM:
3196                 conn->stop_stage = 0;
3197                 break;
3198         default:
3199                 break;
3200         }
3201         spin_unlock_bh(&session->frwd_lock);
3202
3203         iscsi_unblock_session(session->cls_session);
3204         wake_up(&session->ehwait);
3205         return 0;
3206 }
3207 EXPORT_SYMBOL_GPL(iscsi_conn_start);
3208
3209 static void
3210 fail_mgmt_tasks(struct iscsi_session *session, struct iscsi_conn *conn)
3211 {
3212         struct iscsi_task *task;
3213         int i, state;
3214
3215         for (i = 0; i < conn->session->cmds_max; i++) {
3216                 task = conn->session->cmds[i];
3217                 if (task->sc)
3218                         continue;
3219
3220                 if (task->state == ISCSI_TASK_FREE)
3221                         continue;
3222
3223                 ISCSI_DBG_SESSION(conn->session,
3224                                   "failing mgmt itt 0x%x state %d\n",
3225                                   task->itt, task->state);
3226
3227                 spin_lock_bh(&session->back_lock);
3228                 if (cleanup_queued_task(task)) {
3229                         spin_unlock_bh(&session->back_lock);
3230                         continue;
3231                 }
3232
3233                 state = ISCSI_TASK_ABRT_SESS_RECOV;
3234                 if (task->state == ISCSI_TASK_PENDING)
3235                         state = ISCSI_TASK_COMPLETED;
3236                 iscsi_complete_task(task, state);
3237                 spin_unlock_bh(&session->back_lock);
3238         }
3239 }
3240
3241 void iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
3242 {
3243         struct iscsi_conn *conn = cls_conn->dd_data;
3244         struct iscsi_session *session = conn->session;
3245         int old_stop_stage;
3246
3247         mutex_lock(&session->eh_mutex);
3248         spin_lock_bh(&session->frwd_lock);
3249         if (conn->stop_stage == STOP_CONN_TERM) {
3250                 spin_unlock_bh(&session->frwd_lock);
3251                 mutex_unlock(&session->eh_mutex);
3252                 return;
3253         }
3254
3255         /*
3256          * When this is called for the in_login state, we only want to clean
3257          * up the login task and connection. We do not need to block and set
3258          * the recovery state again
3259          */
3260         if (flag == STOP_CONN_TERM)
3261                 session->state = ISCSI_STATE_TERMINATE;
3262         else if (conn->stop_stage != STOP_CONN_RECOVER)
3263                 session->state = ISCSI_STATE_IN_RECOVERY;
3264
3265         old_stop_stage = conn->stop_stage;
3266         conn->stop_stage = flag;
3267         spin_unlock_bh(&session->frwd_lock);
3268
3269         del_timer_sync(&conn->transport_timer);
3270         iscsi_suspend_tx(conn);
3271
3272         spin_lock_bh(&session->frwd_lock);
3273         conn->c_stage = ISCSI_CONN_STOPPED;
3274         spin_unlock_bh(&session->frwd_lock);
3275
3276         /*
3277          * for connection level recovery we should not calculate
3278          * header digest. conn->hdr_size used for optimization
3279          * in hdr_extract() and will be re-negotiated at
3280          * set_param() time.
3281          */
3282         if (flag == STOP_CONN_RECOVER) {
3283                 conn->hdrdgst_en = 0;
3284                 conn->datadgst_en = 0;
3285                 if (session->state == ISCSI_STATE_IN_RECOVERY &&
3286                     old_stop_stage != STOP_CONN_RECOVER) {
3287                         ISCSI_DBG_SESSION(session, "blocking session\n");
3288                         iscsi_block_session(session->cls_session);
3289                 }
3290         }
3291
3292         /*
3293          * flush queues.
3294          */
3295         spin_lock_bh(&session->frwd_lock);
3296         fail_scsi_tasks(conn, -1, DID_TRANSPORT_DISRUPTED);
3297         fail_mgmt_tasks(session, conn);
3298         memset(&session->tmhdr, 0, sizeof(session->tmhdr));
3299         spin_unlock_bh(&session->frwd_lock);
3300         mutex_unlock(&session->eh_mutex);
3301 }
3302 EXPORT_SYMBOL_GPL(iscsi_conn_stop);
3303
3304 int iscsi_conn_bind(struct iscsi_cls_session *cls_session,
3305                     struct iscsi_cls_conn *cls_conn, int is_leading)
3306 {
3307         struct iscsi_session *session = cls_session->dd_data;
3308         struct iscsi_conn *conn = cls_conn->dd_data;
3309
3310         spin_lock_bh(&session->frwd_lock);
3311         if (is_leading)
3312                 session->leadconn = conn;
3313         spin_unlock_bh(&session->frwd_lock);
3314
3315         /*
3316          * The target could have reduced it's window size between logins, so
3317          * we have to reset max/exp cmdsn so we can see the new values.
3318          */
3319         spin_lock_bh(&session->back_lock);
3320         session->max_cmdsn = session->exp_cmdsn = session->cmdsn + 1;
3321         spin_unlock_bh(&session->back_lock);
3322         /*
3323          * Unblock xmitworker(), Login Phase will pass through.
3324          */
3325         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
3326         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
3327         return 0;
3328 }
3329 EXPORT_SYMBOL_GPL(iscsi_conn_bind);
3330
3331 int iscsi_switch_str_param(char **param, char *new_val_buf)
3332 {
3333         char *new_val;
3334
3335         if (*param) {
3336                 if (!strcmp(*param, new_val_buf))
3337                         return 0;
3338         }
3339
3340         new_val = kstrdup(new_val_buf, GFP_NOIO);
3341         if (!new_val)
3342                 return -ENOMEM;
3343
3344         kfree(*param);
3345         *param = new_val;
3346         return 0;
3347 }
3348 EXPORT_SYMBOL_GPL(iscsi_switch_str_param);
3349
3350 int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
3351                     enum iscsi_param param, char *buf, int buflen)
3352 {
3353         struct iscsi_conn *conn = cls_conn->dd_data;
3354         struct iscsi_session *session = conn->session;
3355         int val;
3356
3357         switch(param) {
3358         case ISCSI_PARAM_FAST_ABORT:
3359                 sscanf(buf, "%d", &session->fast_abort);
3360                 break;
3361         case ISCSI_PARAM_ABORT_TMO:
3362                 sscanf(buf, "%d", &session->abort_timeout);
3363                 break;
3364         case ISCSI_PARAM_LU_RESET_TMO:
3365                 sscanf(buf, "%d", &session->lu_reset_timeout);
3366                 break;
3367         case ISCSI_PARAM_TGT_RESET_TMO:
3368                 sscanf(buf, "%d", &session->tgt_reset_timeout);
3369                 break;
3370         case ISCSI_PARAM_PING_TMO:
3371                 sscanf(buf, "%d", &conn->ping_timeout);
3372                 break;
3373         case ISCSI_PARAM_RECV_TMO:
3374                 sscanf(buf, "%d", &conn->recv_timeout);
3375                 break;
3376         case ISCSI_PARAM_MAX_RECV_DLENGTH:
3377                 sscanf(buf, "%d", &conn->max_recv_dlength);
3378                 break;
3379         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3380                 sscanf(buf, "%d", &conn->max_xmit_dlength);
3381                 break;
3382         case ISCSI_PARAM_HDRDGST_EN:
3383                 sscanf(buf, "%d", &conn->hdrdgst_en);
3384                 break;
3385         case ISCSI_PARAM_DATADGST_EN:
3386                 sscanf(buf, "%d", &conn->datadgst_en);
3387                 break;
3388         case ISCSI_PARAM_INITIAL_R2T_EN:
3389                 sscanf(buf, "%d", &session->initial_r2t_en);
3390                 break;
3391         case ISCSI_PARAM_MAX_R2T:
3392                 sscanf(buf, "%hu", &session->max_r2t);
3393                 break;
3394         case ISCSI_PARAM_IMM_DATA_EN:
3395                 sscanf(buf, "%d", &session->imm_data_en);
3396                 break;
3397         case ISCSI_PARAM_FIRST_BURST:
3398                 sscanf(buf, "%d", &session->first_burst);
3399                 break;
3400         case ISCSI_PARAM_MAX_BURST:
3401                 sscanf(buf, "%d", &session->max_burst);
3402                 break;
3403         case ISCSI_PARAM_PDU_INORDER_EN:
3404                 sscanf(buf, "%d", &session->pdu_inorder_en);
3405                 break;
3406         case ISCSI_PARAM_DATASEQ_INORDER_EN:
3407                 sscanf(buf, "%d", &session->dataseq_inorder_en);
3408                 break;
3409         case ISCSI_PARAM_ERL:
3410                 sscanf(buf, "%d", &session->erl);
3411                 break;
3412         case ISCSI_PARAM_EXP_STATSN:
3413                 sscanf(buf, "%u", &conn->exp_statsn);
3414                 break;
3415         case ISCSI_PARAM_USERNAME:
3416                 return iscsi_switch_str_param(&session->username, buf);
3417         case ISCSI_PARAM_USERNAME_IN:
3418                 return iscsi_switch_str_param(&session->username_in, buf);
3419         case ISCSI_PARAM_PASSWORD:
3420                 return iscsi_switch_str_param(&session->password, buf);
3421         case ISCSI_PARAM_PASSWORD_IN:
3422                 return iscsi_switch_str_param(&session->password_in, buf);
3423         case ISCSI_PARAM_TARGET_NAME:
3424                 return iscsi_switch_str_param(&session->targetname, buf);
3425         case ISCSI_PARAM_TARGET_ALIAS:
3426                 return iscsi_switch_str_param(&session->targetalias, buf);
3427         case ISCSI_PARAM_TPGT:
3428                 sscanf(buf, "%d", &session->tpgt);
3429                 break;
3430         case ISCSI_PARAM_PERSISTENT_PORT:
3431                 sscanf(buf, "%d", &conn->persistent_port);
3432                 break;
3433         case ISCSI_PARAM_PERSISTENT_ADDRESS:
3434                 return iscsi_switch_str_param(&conn->persistent_address, buf);
3435         case ISCSI_PARAM_IFACE_NAME:
3436                 return iscsi_switch_str_param(&session->ifacename, buf);
3437         case ISCSI_PARAM_INITIATOR_NAME:
3438                 return iscsi_switch_str_param(&session->initiatorname, buf);
3439         case ISCSI_PARAM_BOOT_ROOT:
3440                 return iscsi_switch_str_param(&session->boot_root, buf);
3441         case ISCSI_PARAM_BOOT_NIC:
3442                 return iscsi_switch_str_param(&session->boot_nic, buf);
3443         case ISCSI_PARAM_BOOT_TARGET:
3444                 return iscsi_switch_str_param(&session->boot_target, buf);
3445         case ISCSI_PARAM_PORTAL_TYPE:
3446                 return iscsi_switch_str_param(&session->portal_type, buf);
3447         case ISCSI_PARAM_DISCOVERY_PARENT_TYPE:
3448                 return iscsi_switch_str_param(&session->discovery_parent_type,
3449                                               buf);
3450         case ISCSI_PARAM_DISCOVERY_SESS:
3451                 sscanf(buf, "%d", &val);
3452                 session->discovery_sess = !!val;
3453                 break;
3454         case ISCSI_PARAM_LOCAL_IPADDR:
3455                 return iscsi_switch_str_param(&conn->local_ipaddr, buf);
3456         default:
3457                 return -ENOSYS;
3458         }
3459
3460         return 0;
3461 }
3462 EXPORT_SYMBOL_GPL(iscsi_set_param);
3463
3464 int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
3465                             enum iscsi_param param, char *buf)
3466 {
3467         struct iscsi_session *session = cls_session->dd_data;
3468         int len;
3469
3470         switch(param) {
3471         case ISCSI_PARAM_FAST_ABORT:
3472                 len = sysfs_emit(buf, "%d\n", session->fast_abort);
3473                 break;
3474         case ISCSI_PARAM_ABORT_TMO:
3475                 len = sysfs_emit(buf, "%d\n", session->abort_timeout);
3476                 break;
3477         case ISCSI_PARAM_LU_RESET_TMO:
3478                 len = sysfs_emit(buf, "%d\n", session->lu_reset_timeout);
3479                 break;
3480         case ISCSI_PARAM_TGT_RESET_TMO:
3481                 len = sysfs_emit(buf, "%d\n", session->tgt_reset_timeout);
3482                 break;
3483         case ISCSI_PARAM_INITIAL_R2T_EN:
3484                 len = sysfs_emit(buf, "%d\n", session->initial_r2t_en);
3485                 break;
3486         case ISCSI_PARAM_MAX_R2T:
3487                 len = sysfs_emit(buf, "%hu\n", session->max_r2t);
3488                 break;
3489         case ISCSI_PARAM_IMM_DATA_EN:
3490                 len = sysfs_emit(buf, "%d\n", session->imm_data_en);
3491                 break;
3492         case ISCSI_PARAM_FIRST_BURST:
3493                 len = sysfs_emit(buf, "%u\n", session->first_burst);
3494                 break;
3495         case ISCSI_PARAM_MAX_BURST:
3496                 len = sysfs_emit(buf, "%u\n", session->max_burst);
3497                 break;
3498         case ISCSI_PARAM_PDU_INORDER_EN:
3499                 len = sysfs_emit(buf, "%d\n", session->pdu_inorder_en);
3500                 break;
3501         case ISCSI_PARAM_DATASEQ_INORDER_EN:
3502                 len = sysfs_emit(buf, "%d\n", session->dataseq_inorder_en);
3503                 break;
3504         case ISCSI_PARAM_DEF_TASKMGMT_TMO:
3505                 len = sysfs_emit(buf, "%d\n", session->def_taskmgmt_tmo);
3506                 break;
3507         case ISCSI_PARAM_ERL:
3508                 len = sysfs_emit(buf, "%d\n", session->erl);
3509                 break;
3510         case ISCSI_PARAM_TARGET_NAME:
3511                 len = sysfs_emit(buf, "%s\n", session->targetname);
3512                 break;
3513         case ISCSI_PARAM_TARGET_ALIAS:
3514                 len = sysfs_emit(buf, "%s\n", session->targetalias);
3515                 break;
3516         case ISCSI_PARAM_TPGT:
3517                 len = sysfs_emit(buf, "%d\n", session->tpgt);
3518                 break;
3519         case ISCSI_PARAM_USERNAME:
3520                 len = sysfs_emit(buf, "%s\n", session->username);
3521                 break;
3522         case ISCSI_PARAM_USERNAME_IN:
3523                 len = sysfs_emit(buf, "%s\n", session->username_in);
3524                 break;
3525         case ISCSI_PARAM_PASSWORD:
3526                 len = sysfs_emit(buf, "%s\n", session->password);
3527                 break;
3528         case ISCSI_PARAM_PASSWORD_IN:
3529                 len = sysfs_emit(buf, "%s\n", session->password_in);
3530                 break;
3531         case ISCSI_PARAM_IFACE_NAME:
3532                 len = sysfs_emit(buf, "%s\n", session->ifacename);
3533                 break;
3534         case ISCSI_PARAM_INITIATOR_NAME:
3535                 len = sysfs_emit(buf, "%s\n", session->initiatorname);
3536                 break;
3537         case ISCSI_PARAM_BOOT_ROOT:
3538                 len = sysfs_emit(buf, "%s\n", session->boot_root);
3539                 break;
3540         case ISCSI_PARAM_BOOT_NIC:
3541                 len = sysfs_emit(buf, "%s\n", session->boot_nic);
3542                 break;
3543         case ISCSI_PARAM_BOOT_TARGET:
3544                 len = sysfs_emit(buf, "%s\n", session->boot_target);
3545                 break;
3546         case ISCSI_PARAM_AUTO_SND_TGT_DISABLE:
3547                 len = sysfs_emit(buf, "%u\n", session->auto_snd_tgt_disable);
3548                 break;
3549         case ISCSI_PARAM_DISCOVERY_SESS:
3550                 len = sysfs_emit(buf, "%u\n", session->discovery_sess);
3551                 break;
3552         case ISCSI_PARAM_PORTAL_TYPE:
3553                 len = sysfs_emit(buf, "%s\n", session->portal_type);
3554                 break;
3555         case ISCSI_PARAM_CHAP_AUTH_EN:
3556                 len = sysfs_emit(buf, "%u\n", session->chap_auth_en);
3557                 break;
3558         case ISCSI_PARAM_DISCOVERY_LOGOUT_EN:
3559                 len = sysfs_emit(buf, "%u\n", session->discovery_logout_en);
3560                 break;
3561         case ISCSI_PARAM_BIDI_CHAP_EN:
3562                 len = sysfs_emit(buf, "%u\n", session->bidi_chap_en);
3563                 break;
3564         case ISCSI_PARAM_DISCOVERY_AUTH_OPTIONAL:
3565                 len = sysfs_emit(buf, "%u\n", session->discovery_auth_optional);
3566                 break;
3567         case ISCSI_PARAM_DEF_TIME2WAIT:
3568                 len = sysfs_emit(buf, "%d\n", session->time2wait);
3569                 break;
3570         case ISCSI_PARAM_DEF_TIME2RETAIN:
3571                 len = sysfs_emit(buf, "%d\n", session->time2retain);
3572                 break;
3573         case ISCSI_PARAM_TSID:
3574                 len = sysfs_emit(buf, "%u\n", session->tsid);
3575                 break;
3576         case ISCSI_PARAM_ISID:
3577                 len = sysfs_emit(buf, "%02x%02x%02x%02x%02x%02x\n",
3578                               session->isid[0], session->isid[1],
3579                               session->isid[2], session->isid[3],
3580                               session->isid[4], session->isid[5]);
3581                 break;
3582         case ISCSI_PARAM_DISCOVERY_PARENT_IDX:
3583                 len = sysfs_emit(buf, "%u\n", session->discovery_parent_idx);
3584                 break;
3585         case ISCSI_PARAM_DISCOVERY_PARENT_TYPE:
3586                 if (session->discovery_parent_type)
3587                         len = sysfs_emit(buf, "%s\n",
3588                                       session->discovery_parent_type);
3589                 else
3590                         len = sysfs_emit(buf, "\n");
3591                 break;
3592         default:
3593                 return -ENOSYS;
3594         }
3595
3596         return len;
3597 }
3598 EXPORT_SYMBOL_GPL(iscsi_session_get_param);
3599
3600 int iscsi_conn_get_addr_param(struct sockaddr_storage *addr,
3601                               enum iscsi_param param, char *buf)
3602 {
3603         struct sockaddr_in6 *sin6 = NULL;
3604         struct sockaddr_in *sin = NULL;
3605         int len;
3606
3607         switch (addr->ss_family) {
3608         case AF_INET:
3609                 sin = (struct sockaddr_in *)addr;
3610                 break;
3611         case AF_INET6:
3612                 sin6 = (struct sockaddr_in6 *)addr;
3613                 break;
3614         default:
3615                 return -EINVAL;
3616         }
3617
3618         switch (param) {
3619         case ISCSI_PARAM_CONN_ADDRESS:
3620         case ISCSI_HOST_PARAM_IPADDRESS:
3621                 if (sin)
3622                         len = sysfs_emit(buf, "%pI4\n", &sin->sin_addr.s_addr);
3623                 else
3624                         len = sysfs_emit(buf, "%pI6\n", &sin6->sin6_addr);
3625                 break;
3626         case ISCSI_PARAM_CONN_PORT:
3627         case ISCSI_PARAM_LOCAL_PORT:
3628                 if (sin)
3629                         len = sysfs_emit(buf, "%hu\n", be16_to_cpu(sin->sin_port));
3630                 else
3631                         len = sysfs_emit(buf, "%hu\n",
3632                                       be16_to_cpu(sin6->sin6_port));
3633                 break;
3634         default:
3635                 return -EINVAL;
3636         }
3637
3638         return len;
3639 }
3640 EXPORT_SYMBOL_GPL(iscsi_conn_get_addr_param);
3641
3642 int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
3643                          enum iscsi_param param, char *buf)
3644 {
3645         struct iscsi_conn *conn = cls_conn->dd_data;
3646         int len;
3647
3648         switch(param) {
3649         case ISCSI_PARAM_PING_TMO:
3650                 len = sysfs_emit(buf, "%u\n", conn->ping_timeout);
3651                 break;
3652         case ISCSI_PARAM_RECV_TMO:
3653                 len = sysfs_emit(buf, "%u\n", conn->recv_timeout);
3654                 break;
3655         case ISCSI_PARAM_MAX_RECV_DLENGTH:
3656                 len = sysfs_emit(buf, "%u\n", conn->max_recv_dlength);
3657                 break;
3658         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3659                 len = sysfs_emit(buf, "%u\n", conn->max_xmit_dlength);
3660                 break;
3661         case ISCSI_PARAM_HDRDGST_EN:
3662                 len = sysfs_emit(buf, "%d\n", conn->hdrdgst_en);
3663                 break;
3664         case ISCSI_PARAM_DATADGST_EN:
3665                 len = sysfs_emit(buf, "%d\n", conn->datadgst_en);
3666                 break;
3667         case ISCSI_PARAM_IFMARKER_EN:
3668                 len = sysfs_emit(buf, "%d\n", conn->ifmarker_en);
3669                 break;
3670         case ISCSI_PARAM_OFMARKER_EN:
3671                 len = sysfs_emit(buf, "%d\n", conn->ofmarker_en);
3672                 break;
3673         case ISCSI_PARAM_EXP_STATSN:
3674                 len = sysfs_emit(buf, "%u\n", conn->exp_statsn);
3675                 break;
3676         case ISCSI_PARAM_PERSISTENT_PORT:
3677                 len = sysfs_emit(buf, "%d\n", conn->persistent_port);
3678                 break;
3679         case ISCSI_PARAM_PERSISTENT_ADDRESS:
3680                 len = sysfs_emit(buf, "%s\n", conn->persistent_address);
3681                 break;
3682         case ISCSI_PARAM_STATSN:
3683                 len = sysfs_emit(buf, "%u\n", conn->statsn);
3684                 break;
3685         case ISCSI_PARAM_MAX_SEGMENT_SIZE:
3686                 len = sysfs_emit(buf, "%u\n", conn->max_segment_size);
3687                 break;
3688         case ISCSI_PARAM_KEEPALIVE_TMO:
3689                 len = sysfs_emit(buf, "%u\n", conn->keepalive_tmo);
3690                 break;
3691         case ISCSI_PARAM_LOCAL_PORT:
3692                 len = sysfs_emit(buf, "%u\n", conn->local_port);
3693                 break;
3694         case ISCSI_PARAM_TCP_TIMESTAMP_STAT:
3695                 len = sysfs_emit(buf, "%u\n", conn->tcp_timestamp_stat);
3696                 break;
3697         case ISCSI_PARAM_TCP_NAGLE_DISABLE:
3698                 len = sysfs_emit(buf, "%u\n", conn->tcp_nagle_disable);
3699                 break;
3700         case ISCSI_PARAM_TCP_WSF_DISABLE:
3701                 len = sysfs_emit(buf, "%u\n", conn->tcp_wsf_disable);
3702                 break;
3703         case ISCSI_PARAM_TCP_TIMER_SCALE:
3704                 len = sysfs_emit(buf, "%u\n", conn->tcp_timer_scale);
3705                 break;
3706         case ISCSI_PARAM_TCP_TIMESTAMP_EN:
3707                 len = sysfs_emit(buf, "%u\n", conn->tcp_timestamp_en);
3708                 break;
3709         case ISCSI_PARAM_IP_FRAGMENT_DISABLE:
3710                 len = sysfs_emit(buf, "%u\n", conn->fragment_disable);
3711                 break;
3712         case ISCSI_PARAM_IPV4_TOS:
3713                 len = sysfs_emit(buf, "%u\n", conn->ipv4_tos);
3714                 break;
3715         case ISCSI_PARAM_IPV6_TC:
3716                 len = sysfs_emit(buf, "%u\n", conn->ipv6_traffic_class);
3717                 break;
3718         case ISCSI_PARAM_IPV6_FLOW_LABEL:
3719                 len = sysfs_emit(buf, "%u\n", conn->ipv6_flow_label);
3720                 break;
3721         case ISCSI_PARAM_IS_FW_ASSIGNED_IPV6:
3722                 len = sysfs_emit(buf, "%u\n", conn->is_fw_assigned_ipv6);
3723                 break;
3724         case ISCSI_PARAM_TCP_XMIT_WSF:
3725                 len = sysfs_emit(buf, "%u\n", conn->tcp_xmit_wsf);
3726                 break;
3727         case ISCSI_PARAM_TCP_RECV_WSF:
3728                 len = sysfs_emit(buf, "%u\n", conn->tcp_recv_wsf);
3729                 break;
3730         case ISCSI_PARAM_LOCAL_IPADDR:
3731                 len = sysfs_emit(buf, "%s\n", conn->local_ipaddr);
3732                 break;
3733         default:
3734                 return -ENOSYS;
3735         }
3736
3737         return len;
3738 }
3739 EXPORT_SYMBOL_GPL(iscsi_conn_get_param);
3740
3741 int iscsi_host_get_param(struct Scsi_Host *shost, enum iscsi_host_param param,
3742                          char *buf)
3743 {
3744         struct iscsi_host *ihost = shost_priv(shost);
3745         int len;
3746
3747         switch (param) {
3748         case ISCSI_HOST_PARAM_NETDEV_NAME:
3749                 len = sysfs_emit(buf, "%s\n", ihost->netdev);
3750                 break;
3751         case ISCSI_HOST_PARAM_HWADDRESS:
3752                 len = sysfs_emit(buf, "%s\n", ihost->hwaddress);
3753                 break;
3754         case ISCSI_HOST_PARAM_INITIATOR_NAME:
3755                 len = sysfs_emit(buf, "%s\n", ihost->initiatorname);
3756                 break;
3757         default:
3758                 return -ENOSYS;
3759         }
3760
3761         return len;
3762 }
3763 EXPORT_SYMBOL_GPL(iscsi_host_get_param);
3764
3765 int iscsi_host_set_param(struct Scsi_Host *shost, enum iscsi_host_param param,
3766                          char *buf, int buflen)
3767 {
3768         struct iscsi_host *ihost = shost_priv(shost);
3769
3770         switch (param) {
3771         case ISCSI_HOST_PARAM_NETDEV_NAME:
3772                 return iscsi_switch_str_param(&ihost->netdev, buf);
3773         case ISCSI_HOST_PARAM_HWADDRESS:
3774                 return iscsi_switch_str_param(&ihost->hwaddress, buf);
3775         case ISCSI_HOST_PARAM_INITIATOR_NAME:
3776                 return iscsi_switch_str_param(&ihost->initiatorname, buf);
3777         default:
3778                 return -ENOSYS;
3779         }
3780
3781         return 0;
3782 }
3783 EXPORT_SYMBOL_GPL(iscsi_host_set_param);
3784
3785 MODULE_AUTHOR("Mike Christie");
3786 MODULE_DESCRIPTION("iSCSI library functions");
3787 MODULE_LICENSE("GPL");