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