drivers/scsi/libiscsi.c

   1 /*
   2  * iSCSI lib functions
   3  *
   4  * Copyright (C) 2006 Red Hat, Inc.  All rights reserved.
   5  * Copyright (C) 2004 - 2006 Mike Christie
   6  * Copyright (C) 2004 - 2005 Dmitry Yusupov
   7  * Copyright (C) 2004 - 2005 Alex Aizman
   8  * maintained by open-iscsi@googlegroups.com
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  23  */
  24 #include <linux/types.h>
  25 #include <linux/kfifo.h>
  26 #include <linux/delay.h>
  27 #include <linux/log2.h>
  28 #include <linux/slab.h>
  29 #include <linux/sched/signal.h>
  30 #include <linux/module.h>
  31 #include <asm/unaligned.h>
  32 #include <net/tcp.h>
  33 #include <scsi/scsi_cmnd.h>
  34 #include <scsi/scsi_device.h>
  35 #include <scsi/scsi_eh.h>
  36 #include <scsi/scsi_tcq.h>
  37 #include <scsi/scsi_host.h>
  38 #include <scsi/scsi.h>
  39 #include <scsi/iscsi_proto.h>
  40 #include <scsi/scsi_transport.h>
  41 #include <scsi/scsi_transport_iscsi.h>
  42 #include <scsi/libiscsi.h>
  43 #include <trace/events/iscsi.h>
  44
  45 static int iscsi_dbg_lib_conn;
  46 module_param_named(debug_libiscsi_conn, iscsi_dbg_lib_conn, int,
  47                    S_IRUGO | S_IWUSR);
  48 MODULE_PARM_DESC(debug_libiscsi_conn,
  49                  "Turn on debugging for connections in libiscsi module. "
  50                  "Set to 1 to turn on, and zero to turn off. Default is off.");
  51
  52 static int iscsi_dbg_lib_session;
  53 module_param_named(debug_libiscsi_session, iscsi_dbg_lib_session, int,
  54                    S_IRUGO | S_IWUSR);
  55 MODULE_PARM_DESC(debug_libiscsi_session,
  56                  "Turn on debugging for sessions in libiscsi module. "
  57                  "Set to 1 to turn on, and zero to turn off. Default is off.");
  58
  59 static int iscsi_dbg_lib_eh;
  60 module_param_named(debug_libiscsi_eh, iscsi_dbg_lib_eh, int,
  61                    S_IRUGO | S_IWUSR);
  62 MODULE_PARM_DESC(debug_libiscsi_eh,
  63                  "Turn on debugging for error handling in libiscsi module. "
  64                  "Set to 1 to turn on, and zero to turn off. Default is off.");
  65
  66 #define ISCSI_DBG_CONN(_conn, dbg_fmt, arg...)                  \
  67         do {                                                    \
  68                 if (iscsi_dbg_lib_conn)                         \
  69                         iscsi_conn_printk(KERN_INFO, _conn,     \
  70                                              "%s " dbg_fmt,     \
  71                                              __func__, ##arg);  \
  72                 iscsi_dbg_trace(trace_iscsi_dbg_conn,           \
  73                                 &(_conn)->cls_conn->dev,        \
  74                                 "%s " dbg_fmt, __func__, ##arg);\
  75         } while (0);
  76
  77 #define ISCSI_DBG_SESSION(_session, dbg_fmt, arg...)                    \
  78         do {                                                            \
  79                 if (iscsi_dbg_lib_session)                              \
  80                         iscsi_session_printk(KERN_INFO, _session,       \
  81                                              "%s " dbg_fmt,             \
  82                                              __func__, ##arg);          \
  83                 iscsi_dbg_trace(trace_iscsi_dbg_session,                \
  84                                 &(_session)->cls_session->dev,          \
  85                                 "%s " dbg_fmt, __func__, ##arg);        \
  86         } while (0);
  87
  88 #define ISCSI_DBG_EH(_session, dbg_fmt, arg...)                         \
  89         do {                                                            \
  90                 if (iscsi_dbg_lib_eh)                                   \
  91                         iscsi_session_printk(KERN_INFO, _session,       \
  92                                              "%s " dbg_fmt,             \
  93                                              __func__, ##arg);          \
  94                 iscsi_dbg_trace(trace_iscsi_dbg_eh,                     \
  95                                 &(_session)->cls_session->dev,          \
  96                                 "%s " dbg_fmt, __func__, ##arg);        \
  97         } while (0);
  98
  99 inline void iscsi_conn_queue_work(struct iscsi_conn *conn)
 100 {
 101         struct Scsi_Host *shost = conn->session->host;
 102         struct iscsi_host *ihost = shost_priv(shost);
 103
 104         if (ihost->workq)
 105                 queue_work(ihost->workq, &conn->xmitwork);
 106 }
 107 EXPORT_SYMBOL_GPL(iscsi_conn_queue_work);
 108
 109 static void __iscsi_update_cmdsn(struct iscsi_session *session,
 110                                  uint32_t exp_cmdsn, uint32_t max_cmdsn)
 111 {
 112         /*
 113          * standard specifies this check for when to update expected and
 114          * max sequence numbers
 115          */
 116         if (iscsi_sna_lt(max_cmdsn, exp_cmdsn - 1))
 117                 return;
 118
 119         if (exp_cmdsn != session->exp_cmdsn &&
 120             !iscsi_sna_lt(exp_cmdsn, session->exp_cmdsn))
 121                 session->exp_cmdsn = exp_cmdsn;
 122
 123         if (max_cmdsn != session->max_cmdsn &&
 124             !iscsi_sna_lt(max_cmdsn, session->max_cmdsn))
 125                 session->max_cmdsn = max_cmdsn;
 126 }
 127
 128 void iscsi_update_cmdsn(struct iscsi_session *session, struct iscsi_nopin *hdr)
 129 {
 130         __iscsi_update_cmdsn(session, be32_to_cpu(hdr->exp_cmdsn),
 131                              be32_to_cpu(hdr->max_cmdsn));
 132 }
 133 EXPORT_SYMBOL_GPL(iscsi_update_cmdsn);
 134
 135 /**
 136  * iscsi_prep_data_out_pdu - initialize Data-Out
 137  * @task: scsi command task
 138  * @r2t: R2T info
 139  * @hdr: iscsi data in pdu
 140  *
 141  * Notes:
 142  *      Initialize Data-Out within this R2T sequence and finds
 143  *      proper data_offset within this SCSI command.
 144  *
 145  *      This function is called with connection lock taken.
 146  **/
 147 void iscsi_prep_data_out_pdu(struct iscsi_task *task, struct iscsi_r2t_info *r2t,
 148                            struct iscsi_data *hdr)
 149 {
 150         struct iscsi_conn *conn = task->conn;
 151         unsigned int left = r2t->data_length - r2t->sent;
 152
 153         task->hdr_len = sizeof(struct iscsi_data);
 154
 155         memset(hdr, 0, sizeof(struct iscsi_data));
 156         hdr->ttt = r2t->ttt;
 157         hdr->datasn = cpu_to_be32(r2t->datasn);
 158         r2t->datasn++;
 159         hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
 160         hdr->lun = task->lun;
 161         hdr->itt = task->hdr_itt;
 162         hdr->exp_statsn = r2t->exp_statsn;
 163         hdr->offset = cpu_to_be32(r2t->data_offset + r2t->sent);
 164         if (left > conn->max_xmit_dlength) {
 165                 hton24(hdr->dlength, conn->max_xmit_dlength);
 166                 r2t->data_count = conn->max_xmit_dlength;
 167                 hdr->flags = 0;
 168         } else {
 169                 hton24(hdr->dlength, left);
 170                 r2t->data_count = left;
 171                 hdr->flags = ISCSI_FLAG_CMD_FINAL;
 172         }
 173         conn->dataout_pdus_cnt++;
 174 }
 175 EXPORT_SYMBOL_GPL(iscsi_prep_data_out_pdu);
 176
 177 static int iscsi_add_hdr(struct iscsi_task *task, unsigned len)
 178 {
 179         unsigned exp_len = task->hdr_len + len;
 180
 181         if (exp_len > task->hdr_max) {
 182                 WARN_ON(1);
 183                 return -EINVAL;
 184         }
 185
 186         WARN_ON(len & (ISCSI_PAD_LEN - 1)); /* caller must pad the AHS */
 187         task->hdr_len = exp_len;
 188         return 0;
 189 }
 190
 191 /*
 192  * make an extended cdb AHS
 193  */
 194 static int iscsi_prep_ecdb_ahs(struct iscsi_task *task)
 195 {
 196         struct scsi_cmnd *cmd = task->sc;
 197         unsigned rlen, pad_len;
 198         unsigned short ahslength;
 199         struct iscsi_ecdb_ahdr *ecdb_ahdr;
 200         int rc;
 201
 202         ecdb_ahdr = iscsi_next_hdr(task);
 203         rlen = cmd->cmd_len - ISCSI_CDB_SIZE;
 204
 205         BUG_ON(rlen > sizeof(ecdb_ahdr->ecdb));
 206         ahslength = rlen + sizeof(ecdb_ahdr->reserved);
 207
 208         pad_len = iscsi_padding(rlen);
 209
 210         rc = iscsi_add_hdr(task, sizeof(ecdb_ahdr->ahslength) +
 211                            sizeof(ecdb_ahdr->ahstype) + ahslength + pad_len);
 212         if (rc)
 213                 return rc;
 214
 215         if (pad_len)
 216                 memset(&ecdb_ahdr->ecdb[rlen], 0, pad_len);
 217
 218         ecdb_ahdr->ahslength = cpu_to_be16(ahslength);
 219         ecdb_ahdr->ahstype = ISCSI_AHSTYPE_CDB;
 220         ecdb_ahdr->reserved = 0;
 221         memcpy(ecdb_ahdr->ecdb, cmd->cmnd + ISCSI_CDB_SIZE, rlen);
 222
 223         ISCSI_DBG_SESSION(task->conn->session,
 224                           "iscsi_prep_ecdb_ahs: varlen_cdb_len %d "
 225                           "rlen %d pad_len %d ahs_length %d iscsi_headers_size "
 226                           "%u\n", cmd->cmd_len, rlen, pad_len, ahslength,
 227                           task->hdr_len);
 228         return 0;
 229 }
 230
 231 static int iscsi_prep_bidi_ahs(struct iscsi_task *task)
 232 {
 233         struct scsi_cmnd *sc = task->sc;
 234         struct iscsi_rlength_ahdr *rlen_ahdr;
 235         int rc;
 236
 237         rlen_ahdr = iscsi_next_hdr(task);
 238         rc = iscsi_add_hdr(task, sizeof(*rlen_ahdr));
 239         if (rc)
 240                 return rc;
 241
 242         rlen_ahdr->ahslength =
 243                 cpu_to_be16(sizeof(rlen_ahdr->read_length) +
 244                                                   sizeof(rlen_ahdr->reserved));
 245         rlen_ahdr->ahstype = ISCSI_AHSTYPE_RLENGTH;
 246         rlen_ahdr->reserved = 0;
 247         rlen_ahdr->read_length = cpu_to_be32(scsi_in(sc)->length);
 248
 249         ISCSI_DBG_SESSION(task->conn->session,
 250                           "bidi-in rlen_ahdr->read_length(%d) "
 251                           "rlen_ahdr->ahslength(%d)\n",
 252                           be32_to_cpu(rlen_ahdr->read_length),
 253                           be16_to_cpu(rlen_ahdr->ahslength));
 254         return 0;
 255 }
 256
 257 /**
 258  * iscsi_check_tmf_restrictions - check if a task is affected by TMF
 259  * @task: iscsi task
 260  * @opcode: opcode to check for
 261  *
 262  * During TMF a task has to be checked if it's affected.
 263  * All unrelated I/O can be passed through, but I/O to the
 264  * affected LUN should be restricted.
 265  * If 'fast_abort' is set we won't be sending any I/O to the
 266  * affected LUN.
 267  * Otherwise the target is waiting for all TTTs to be completed,
 268  * so we have to send all outstanding Data-Out PDUs to the target.
 269  */
 270 static int iscsi_check_tmf_restrictions(struct iscsi_task *task, int opcode)
 271 {
 272         struct iscsi_conn *conn = task->conn;
 273         struct iscsi_tm *tmf = &conn->tmhdr;
 274         u64 hdr_lun;
 275
 276         if (conn->tmf_state == TMF_INITIAL)
 277                 return 0;
 278
 279         if ((tmf->opcode & ISCSI_OPCODE_MASK) != ISCSI_OP_SCSI_TMFUNC)
 280                 return 0;
 281
 282         switch (ISCSI_TM_FUNC_VALUE(tmf)) {
 283         case ISCSI_TM_FUNC_LOGICAL_UNIT_RESET:
 284                 /*
 285                  * Allow PDUs for unrelated LUNs
 286                  */
 287                 hdr_lun = scsilun_to_int(&tmf->lun);
 288                 if (hdr_lun != task->sc->device->lun)
 289                         return 0;
 290                 /* fall through */
 291         case ISCSI_TM_FUNC_TARGET_WARM_RESET:
 292                 /*
 293                  * Fail all SCSI cmd PDUs
 294                  */
 295                 if (opcode != ISCSI_OP_SCSI_DATA_OUT) {
 296                         iscsi_conn_printk(KERN_INFO, conn,
 297                                           "task [op %x itt "
 298                                           "0x%x/0x%x] "
 299                                           "rejected.\n",
 300                                           opcode, task->itt,
 301                                           task->hdr_itt);
 302                         return -EACCES;
 303                 }
 304                 /*
 305                  * And also all data-out PDUs in response to R2T
 306                  * if fast_abort is set.
 307                  */
 308                 if (conn->session->fast_abort) {
 309                         iscsi_conn_printk(KERN_INFO, conn,
 310                                           "task [op %x itt "
 311                                           "0x%x/0x%x] fast abort.\n",
 312                                           opcode, task->itt,
 313                                           task->hdr_itt);
 314                         return -EACCES;
 315                 }
 316                 break;
 317         case ISCSI_TM_FUNC_ABORT_TASK:
 318                 /*
 319                  * the caller has already checked if the task
 320                  * they want to abort was in the pending queue so if
 321                  * we are here the cmd pdu has gone out already, and
 322                  * we will only hit this for data-outs
 323                  */
 324                 if (opcode == ISCSI_OP_SCSI_DATA_OUT &&
 325                     task->hdr_itt == tmf->rtt) {
 326                         ISCSI_DBG_SESSION(conn->session,
 327                                           "Preventing task %x/%x from sending "
 328                                           "data-out due to abort task in "
 329                                           "progress\n", task->itt,
 330                                           task->hdr_itt);
 331                         return -EACCES;
 332                 }
 333                 break;
 334         }
 335
 336         return 0;
 337 }
 338
 339 /**
 340  * iscsi_prep_scsi_cmd_pdu - prep iscsi scsi cmd pdu
 341  * @task: iscsi task
 342  *
 343  * Prep basic iSCSI PDU fields for a scsi cmd pdu. The LLD should set
 344  * fields like dlength or final based on how much data it sends
 345  */
 346 static int iscsi_prep_scsi_cmd_pdu(struct iscsi_task *task)
 347 {
 348         struct iscsi_conn *conn = task->conn;
 349         struct iscsi_session *session = conn->session;
 350         struct scsi_cmnd *sc = task->sc;
 351         struct iscsi_scsi_req *hdr;
 352         unsigned hdrlength, cmd_len, transfer_length;
 353         itt_t itt;
 354         int rc;
 355
 356         rc = iscsi_check_tmf_restrictions(task, ISCSI_OP_SCSI_CMD);
 357         if (rc)
 358                 return rc;
 359
 360         if (conn->session->tt->alloc_pdu) {
 361                 rc = conn->session->tt->alloc_pdu(task, ISCSI_OP_SCSI_CMD);
 362                 if (rc)
 363                         return rc;
 364         }
 365         hdr = (struct iscsi_scsi_req *)task->hdr;
 366         itt = hdr->itt;
 367         memset(hdr, 0, sizeof(*hdr));
 368
 369         if (session->tt->parse_pdu_itt)
 370                 hdr->itt = task->hdr_itt = itt;
 371         else
 372                 hdr->itt = task->hdr_itt = build_itt(task->itt,
 373                                                      task->conn->session->age);
 374         task->hdr_len = 0;
 375         rc = iscsi_add_hdr(task, sizeof(*hdr));
 376         if (rc)
 377                 return rc;
 378         hdr->opcode = ISCSI_OP_SCSI_CMD;
 379         hdr->flags = ISCSI_ATTR_SIMPLE;
 380         int_to_scsilun(sc->device->lun, &hdr->lun);
 381         task->lun = hdr->lun;
 382         hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
 383         cmd_len = sc->cmd_len;
 384         if (cmd_len < ISCSI_CDB_SIZE)
 385                 memset(&hdr->cdb[cmd_len], 0, ISCSI_CDB_SIZE - cmd_len);
 386         else if (cmd_len > ISCSI_CDB_SIZE) {
 387                 rc = iscsi_prep_ecdb_ahs(task);
 388                 if (rc)
 389                         return rc;
 390                 cmd_len = ISCSI_CDB_SIZE;
 391         }
 392         memcpy(hdr->cdb, sc->cmnd, cmd_len);
 393
 394         task->imm_count = 0;
 395         if (scsi_bidi_cmnd(sc)) {
 396                 hdr->flags |= ISCSI_FLAG_CMD_READ;
 397                 rc = iscsi_prep_bidi_ahs(task);
 398                 if (rc)
 399                         return rc;
 400         }
 401
 402         if (scsi_get_prot_op(sc) != SCSI_PROT_NORMAL)
 403                 task->protected = true;
 404
 405         transfer_length = scsi_transfer_length(sc);
 406         hdr->data_length = cpu_to_be32(transfer_length);
 407         if (sc->sc_data_direction == DMA_TO_DEVICE) {
 408                 struct iscsi_r2t_info *r2t = &task->unsol_r2t;
 409
 410                 hdr->flags |= ISCSI_FLAG_CMD_WRITE;
 411                 /*
 412                  * Write counters:
 413                  *
 414                  *      imm_count       bytes to be sent right after
 415                  *                      SCSI PDU Header
 416                  *
 417                  *      unsol_count     bytes(as Data-Out) to be sent
 418                  *                      without R2T ack right after
 419                  *                      immediate data
 420                  *
 421                  *      r2t data_length bytes to be sent via R2T ack's
 422                  *
 423                  *      pad_count       bytes to be sent as zero-padding
 424                  */
 425                 memset(r2t, 0, sizeof(*r2t));
 426
 427                 if (session->imm_data_en) {
 428                         if (transfer_length >= session->first_burst)
 429                                 task->imm_count = min(session->first_burst,
 430                                                         conn->max_xmit_dlength);
 431                         else
 432                                 task->imm_count = min(transfer_length,
 433                                                       conn->max_xmit_dlength);
 434                         hton24(hdr->dlength, task->imm_count);
 435                 } else
 436                         zero_data(hdr->dlength);
 437
 438                 if (!session->initial_r2t_en) {
 439                         r2t->data_length = min(session->first_burst,
 440                                                transfer_length) -
 441                                                task->imm_count;
 442                         r2t->data_offset = task->imm_count;
 443                         r2t->ttt = cpu_to_be32(ISCSI_RESERVED_TAG);
 444                         r2t->exp_statsn = cpu_to_be32(conn->exp_statsn);
 445                 }
 446
 447                 if (!task->unsol_r2t.data_length)
 448                         /* No unsolicit Data-Out's */
 449                         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
 450         } else {
 451                 hdr->flags |= ISCSI_FLAG_CMD_FINAL;
 452                 zero_data(hdr->dlength);
 453
 454                 if (sc->sc_data_direction == DMA_FROM_DEVICE)
 455                         hdr->flags |= ISCSI_FLAG_CMD_READ;
 456         }
 457
 458         /* calculate size of additional header segments (AHSs) */
 459         hdrlength = task->hdr_len - sizeof(*hdr);
 460
 461         WARN_ON(hdrlength & (ISCSI_PAD_LEN-1));
 462         hdrlength /= ISCSI_PAD_LEN;
 463
 464         WARN_ON(hdrlength >= 256);
 465         hdr->hlength = hdrlength & 0xFF;
 466         hdr->cmdsn = task->cmdsn = cpu_to_be32(session->cmdsn);
 467
 468         if (session->tt->init_task && session->tt->init_task(task))
 469                 return -EIO;
 470
 471         task->state = ISCSI_TASK_RUNNING;
 472         session->cmdsn++;
 473
 474         conn->scsicmd_pdus_cnt++;
 475         ISCSI_DBG_SESSION(session, "iscsi prep [%s cid %d sc %p cdb 0x%x "
 476                           "itt 0x%x len %d bidi_len %d cmdsn %d win %d]\n",
 477                           scsi_bidi_cmnd(sc) ? "bidirectional" :
 478                           sc->sc_data_direction == DMA_TO_DEVICE ?
 479                           "write" : "read", conn->id, sc, sc->cmnd[0],
 480                           task->itt, transfer_length,
 481                           scsi_bidi_cmnd(sc) ? scsi_in(sc)->length : 0,
 482                           session->cmdsn,
 483                           session->max_cmdsn - session->exp_cmdsn + 1);
 484         return 0;
 485 }
 486
 487 /**
 488  * iscsi_free_task - free a task
 489  * @task: iscsi cmd task
 490  *
 491  * Must be called with session back_lock.
 492  * This function returns the scsi command to scsi-ml or cleans
 493  * up mgmt tasks then returns the task to the pool.
 494  */
 495 static void iscsi_free_task(struct iscsi_task *task)
 496 {
 497         struct iscsi_conn *conn = task->conn;
 498         struct iscsi_session *session = conn->session;
 499         struct scsi_cmnd *sc = task->sc;
 500         int oldstate = task->state;
 501
 502         ISCSI_DBG_SESSION(session, "freeing task itt 0x%x state %d sc %p\n",
 503                           task->itt, task->state, task->sc);
 504
 505         session->tt->cleanup_task(task);
 506         task->state = ISCSI_TASK_FREE;
 507         task->sc = NULL;
 508         /*
 509          * login task is preallocated so do not free
 510          */
 511         if (conn->login_task == task)
 512                 return;
 513
 514         kfifo_in(&session->cmdpool.queue, (void*)&task, sizeof(void*));
 515
 516         if (sc) {
 517                 /* SCSI eh reuses commands to verify us */
 518                 sc->SCp.ptr = NULL;
 519                 /*
 520                  * queue command may call this to free the task, so
 521                  * it will decide how to return sc to scsi-ml.
 522                  */
 523                 if (oldstate != ISCSI_TASK_REQUEUE_SCSIQ)
 524                         sc->scsi_done(sc);
 525         }
 526 }
 527
 528 void __iscsi_get_task(struct iscsi_task *task)
 529 {
 530         refcount_inc(&task->refcount);
 531 }
 532 EXPORT_SYMBOL_GPL(__iscsi_get_task);
 533
 534 void __iscsi_put_task(struct iscsi_task *task)
 535 {
 536         if (refcount_dec_and_test(&task->refcount))
 537                 iscsi_free_task(task);
 538 }
 539 EXPORT_SYMBOL_GPL(__iscsi_put_task);
 540
 541 void iscsi_put_task(struct iscsi_task *task)
 542 {
 543         struct iscsi_session *session = task->conn->session;
 544
 545         /* regular RX path uses back_lock */
 546         spin_lock_bh(&session->back_lock);
 547         __iscsi_put_task(task);
 548         spin_unlock_bh(&session->back_lock);
 549 }
 550 EXPORT_SYMBOL_GPL(iscsi_put_task);
 551
 552 /**
 553  * iscsi_complete_task - finish a task
 554  * @task: iscsi cmd task
 555  * @state: state to complete task with
 556  *
 557  * Must be called with session back_lock.
 558  */
 559 static void iscsi_complete_task(struct iscsi_task *task, int state)
 560 {
 561         struct iscsi_conn *conn = task->conn;
 562
 563         ISCSI_DBG_SESSION(conn->session,
 564                           "complete task itt 0x%x state %d sc %p\n",
 565                           task->itt, task->state, task->sc);
 566         if (task->state == ISCSI_TASK_COMPLETED ||
 567             task->state == ISCSI_TASK_ABRT_TMF ||
 568             task->state == ISCSI_TASK_ABRT_SESS_RECOV ||
 569             task->state == ISCSI_TASK_REQUEUE_SCSIQ)
 570                 return;
 571         WARN_ON_ONCE(task->state == ISCSI_TASK_FREE);
 572         task->state = state;
 573
 574         spin_lock_bh(&conn->taskqueuelock);
 575         if (!list_empty(&task->running)) {
 576                 pr_debug_once("%s while task on list", __func__);
 577                 list_del_init(&task->running);
 578         }
 579         spin_unlock_bh(&conn->taskqueuelock);
 580
 581         if (conn->task == task)
 582                 conn->task = NULL;
 583
 584         if (conn->ping_task == task)
 585                 conn->ping_task = NULL;
 586
 587         /* release get from queueing */
 588         __iscsi_put_task(task);
 589 }
 590
 591 /**
 592  * iscsi_complete_scsi_task - finish scsi task normally
 593  * @task: iscsi task for scsi cmd
 594  * @exp_cmdsn: expected cmd sn in cpu format
 595  * @max_cmdsn: max cmd sn in cpu format
 596  *
 597  * This is used when drivers do not need or cannot perform
 598  * lower level pdu processing.
 599  *
 600  * Called with session back_lock
 601  */
 602 void iscsi_complete_scsi_task(struct iscsi_task *task,
 603                               uint32_t exp_cmdsn, uint32_t max_cmdsn)
 604 {
 605         struct iscsi_conn *conn = task->conn;
 606
 607         ISCSI_DBG_SESSION(conn->session, "[itt 0x%x]\n", task->itt);
 608
 609         conn->last_recv = jiffies;
 610         __iscsi_update_cmdsn(conn->session, exp_cmdsn, max_cmdsn);
 611         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 612 }
 613 EXPORT_SYMBOL_GPL(iscsi_complete_scsi_task);
 614
 615
 616 /*
 617  * session back_lock must be held and if not called for a task that is
 618  * still pending or from the xmit thread, then xmit thread must
 619  * be suspended.
 620  */
 621 static void fail_scsi_task(struct iscsi_task *task, int err)
 622 {
 623         struct iscsi_conn *conn = task->conn;
 624         struct scsi_cmnd *sc;
 625         int state;
 626
 627         /*
 628          * if a command completes and we get a successful tmf response
 629          * we will hit this because the scsi eh abort code does not take
 630          * a ref to the task.
 631          */
 632         sc = task->sc;
 633         if (!sc)
 634                 return;
 635
 636         if (task->state == ISCSI_TASK_PENDING) {
 637                 /*
 638                  * cmd never made it to the xmit thread, so we should not count
 639                  * the cmd in the sequencing
 640                  */
 641                 conn->session->queued_cmdsn--;
 642                 /* it was never sent so just complete like normal */
 643                 state = ISCSI_TASK_COMPLETED;
 644         } else if (err == DID_TRANSPORT_DISRUPTED)
 645                 state = ISCSI_TASK_ABRT_SESS_RECOV;
 646         else
 647                 state = ISCSI_TASK_ABRT_TMF;
 648
 649         sc->result = err << 16;
 650         if (!scsi_bidi_cmnd(sc))
 651                 scsi_set_resid(sc, scsi_bufflen(sc));
 652         else {
 653                 scsi_out(sc)->resid = scsi_out(sc)->length;
 654                 scsi_in(sc)->resid = scsi_in(sc)->length;
 655         }
 656
 657         /* regular RX path uses back_lock */
 658         spin_lock_bh(&conn->session->back_lock);
 659         iscsi_complete_task(task, state);
 660         spin_unlock_bh(&conn->session->back_lock);
 661 }
 662
 663 static int iscsi_prep_mgmt_task(struct iscsi_conn *conn,
 664                                 struct iscsi_task *task)
 665 {
 666         struct iscsi_session *session = conn->session;
 667         struct iscsi_hdr *hdr = task->hdr;
 668         struct iscsi_nopout *nop = (struct iscsi_nopout *)hdr;
 669         uint8_t opcode = hdr->opcode & ISCSI_OPCODE_MASK;
 670
 671         if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
 672                 return -ENOTCONN;
 673
 674         if (opcode != ISCSI_OP_LOGIN && opcode != ISCSI_OP_TEXT)
 675                 nop->exp_statsn = cpu_to_be32(conn->exp_statsn);
 676         /*
 677          * pre-format CmdSN for outgoing PDU.
 678          */
 679         nop->cmdsn = cpu_to_be32(session->cmdsn);
 680         if (hdr->itt != RESERVED_ITT) {
 681                 /*
 682                  * TODO: We always use immediate for normal session pdus.
 683                  * If we start to send tmfs or nops as non-immediate then
 684                  * we should start checking the cmdsn numbers for mgmt tasks.
 685                  *
 686                  * During discovery sessions iscsid sends TEXT as non immediate,
 687                  * but we always only send one PDU at a time.
 688                  */
 689                 if (conn->c_stage == ISCSI_CONN_STARTED &&
 690                     !(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
 691                         session->queued_cmdsn++;
 692                         session->cmdsn++;
 693                 }
 694         }
 695
 696         if (session->tt->init_task && session->tt->init_task(task))
 697                 return -EIO;
 698
 699         if ((hdr->opcode & ISCSI_OPCODE_MASK) == ISCSI_OP_LOGOUT)
 700                 session->state = ISCSI_STATE_LOGGING_OUT;
 701
 702         task->state = ISCSI_TASK_RUNNING;
 703         ISCSI_DBG_SESSION(session, "mgmtpdu [op 0x%x hdr->itt 0x%x "
 704                           "datalen %d]\n", hdr->opcode & ISCSI_OPCODE_MASK,
 705                           hdr->itt, task->data_count);
 706         return 0;
 707 }
 708
 709 static struct iscsi_task *
 710 __iscsi_conn_send_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 711                       char *data, uint32_t data_size)
 712 {
 713         struct iscsi_session *session = conn->session;
 714         struct iscsi_host *ihost = shost_priv(session->host);
 715         uint8_t opcode = hdr->opcode & ISCSI_OPCODE_MASK;
 716         struct iscsi_task *task;
 717         itt_t itt;
 718
 719         if (session->state == ISCSI_STATE_TERMINATE)
 720                 return NULL;
 721
 722         if (opcode == ISCSI_OP_LOGIN || opcode == ISCSI_OP_TEXT) {
 723                 /*
 724                  * Login and Text are sent serially, in
 725                  * request-followed-by-response sequence.
 726                  * Same task can be used. Same ITT must be used.
 727                  * Note that login_task is preallocated at conn_create().
 728                  */
 729                 if (conn->login_task->state != ISCSI_TASK_FREE) {
 730                         iscsi_conn_printk(KERN_ERR, conn, "Login/Text in "
 731                                           "progress. Cannot start new task.\n");
 732                         return NULL;
 733                 }
 734
 735                 if (data_size > ISCSI_DEF_MAX_RECV_SEG_LEN) {
 736                         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);
 737                         return NULL;
 738                 }
 739
 740                 task = conn->login_task;
 741         } else {
 742                 if (session->state != ISCSI_STATE_LOGGED_IN)
 743                         return NULL;
 744
 745                 if (data_size != 0) {
 746                         iscsi_conn_printk(KERN_ERR, conn, "Can not send data buffer of len %u for op 0x%x\n", data_size, opcode);
 747                         return NULL;
 748                 }
 749
 750                 BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
 751                 BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);
 752
 753                 if (!kfifo_out(&session->cmdpool.queue,
 754                                  (void*)&task, sizeof(void*)))
 755                         return NULL;
 756         }
 757         /*
 758          * released in complete pdu for task we expect a response for, and
 759          * released by the lld when it has transmitted the task for
 760          * pdus we do not expect a response for.
 761          */
 762         refcount_set(&task->refcount, 1);
 763         task->conn = conn;
 764         task->sc = NULL;
 765         INIT_LIST_HEAD(&task->running);
 766         task->state = ISCSI_TASK_PENDING;
 767
 768         if (data_size) {
 769                 memcpy(task->data, data, data_size);
 770                 task->data_count = data_size;
 771         } else
 772                 task->data_count = 0;
 773
 774         if (conn->session->tt->alloc_pdu) {
 775                 if (conn->session->tt->alloc_pdu(task, hdr->opcode)) {
 776                         iscsi_conn_printk(KERN_ERR, conn, "Could not allocate "
 777                                          "pdu for mgmt task.\n");
 778                         goto free_task;
 779                 }
 780         }
 781
 782         itt = task->hdr->itt;
 783         task->hdr_len = sizeof(struct iscsi_hdr);
 784         memcpy(task->hdr, hdr, sizeof(struct iscsi_hdr));
 785
 786         if (hdr->itt != RESERVED_ITT) {
 787                 if (session->tt->parse_pdu_itt)
 788                         task->hdr->itt = itt;
 789                 else
 790                         task->hdr->itt = build_itt(task->itt,
 791                                                    task->conn->session->age);
 792         }
 793
 794         if (!ihost->workq) {
 795                 if (iscsi_prep_mgmt_task(conn, task))
 796                         goto free_task;
 797
 798                 if (session->tt->xmit_task(task))
 799                         goto free_task;
 800         } else {
 801                 spin_lock_bh(&conn->taskqueuelock);
 802                 list_add_tail(&task->running, &conn->mgmtqueue);
 803                 spin_unlock_bh(&conn->taskqueuelock);
 804                 iscsi_conn_queue_work(conn);
 805         }
 806
 807         return task;
 808
 809 free_task:
 810         /* regular RX path uses back_lock */
 811         spin_lock(&session->back_lock);
 812         __iscsi_put_task(task);
 813         spin_unlock(&session->back_lock);
 814         return NULL;
 815 }
 816
 817 int iscsi_conn_send_pdu(struct iscsi_cls_conn *cls_conn, struct iscsi_hdr *hdr,
 818                         char *data, uint32_t data_size)
 819 {
 820         struct iscsi_conn *conn = cls_conn->dd_data;
 821         struct iscsi_session *session = conn->session;
 822         int err = 0;
 823
 824         spin_lock_bh(&session->frwd_lock);
 825         if (!__iscsi_conn_send_pdu(conn, hdr, data, data_size))
 826                 err = -EPERM;
 827         spin_unlock_bh(&session->frwd_lock);
 828         return err;
 829 }
 830 EXPORT_SYMBOL_GPL(iscsi_conn_send_pdu);
 831
 832 /**
 833  * iscsi_cmd_rsp - SCSI Command Response processing
 834  * @conn: iscsi connection
 835  * @hdr: iscsi header
 836  * @task: scsi command task
 837  * @data: cmd data buffer
 838  * @datalen: len of buffer
 839  *
 840  * iscsi_cmd_rsp sets up the scsi_cmnd fields based on the PDU and
 841  * then completes the command and task.
 842  **/
 843 static void iscsi_scsi_cmd_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 844                                struct iscsi_task *task, char *data,
 845                                int datalen)
 846 {
 847         struct iscsi_scsi_rsp *rhdr = (struct iscsi_scsi_rsp *)hdr;
 848         struct iscsi_session *session = conn->session;
 849         struct scsi_cmnd *sc = task->sc;
 850
 851         iscsi_update_cmdsn(session, (struct iscsi_nopin*)rhdr);
 852         conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 853
 854         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 855
 856         if (task->protected) {
 857                 sector_t sector;
 858                 u8 ascq;
 859
 860                 /**
 861                  * Transports that didn't implement check_protection
 862                  * callback but still published T10-PI support to scsi-mid
 863                  * deserve this BUG_ON.
 864                  **/
 865                 BUG_ON(!session->tt->check_protection);
 866
 867                 ascq = session->tt->check_protection(task, &sector);
 868                 if (ascq) {
 869                         sc->result = DRIVER_SENSE << 24 |
 870                                      SAM_STAT_CHECK_CONDITION;
 871                         scsi_build_sense_buffer(1, sc->sense_buffer,
 872                                                 ILLEGAL_REQUEST, 0x10, ascq);
 873                         scsi_set_sense_information(sc->sense_buffer,
 874                                                    SCSI_SENSE_BUFFERSIZE,
 875                                                    sector);
 876                         goto out;
 877                 }
 878         }
 879
 880         if (rhdr->response != ISCSI_STATUS_CMD_COMPLETED) {
 881                 sc->result = DID_ERROR << 16;
 882                 goto out;
 883         }
 884
 885         if (rhdr->cmd_status == SAM_STAT_CHECK_CONDITION) {
 886                 uint16_t senselen;
 887
 888                 if (datalen < 2) {
 889 invalid_datalen:
 890                         iscsi_conn_printk(KERN_ERR,  conn,
 891                                          "Got CHECK_CONDITION but invalid data "
 892                                          "buffer size of %d\n", datalen);
 893                         sc->result = DID_BAD_TARGET << 16;
 894                         goto out;
 895                 }
 896
 897                 senselen = get_unaligned_be16(data);
 898                 if (datalen < senselen)
 899                         goto invalid_datalen;
 900
 901                 memcpy(sc->sense_buffer, data + 2,
 902                        min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
 903                 ISCSI_DBG_SESSION(session, "copied %d bytes of sense\n",
 904                                   min_t(uint16_t, senselen,
 905                                   SCSI_SENSE_BUFFERSIZE));
 906         }
 907
 908         if (rhdr->flags & (ISCSI_FLAG_CMD_BIDI_UNDERFLOW |
 909                            ISCSI_FLAG_CMD_BIDI_OVERFLOW)) {
 910                 int res_count = be32_to_cpu(rhdr->bi_residual_count);
 911
 912                 if (scsi_bidi_cmnd(sc) && res_count > 0 &&
 913                                 (rhdr->flags & ISCSI_FLAG_CMD_BIDI_OVERFLOW ||
 914                                  res_count <= scsi_in(sc)->length))
 915                         scsi_in(sc)->resid = res_count;
 916                 else
 917                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 918         }
 919
 920         if (rhdr->flags & (ISCSI_FLAG_CMD_UNDERFLOW |
 921                            ISCSI_FLAG_CMD_OVERFLOW)) {
 922                 int res_count = be32_to_cpu(rhdr->residual_count);
 923
 924                 if (res_count > 0 &&
 925                     (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
 926                      res_count <= scsi_bufflen(sc)))
 927                         /* write side for bidi or uni-io set_resid */
 928                         scsi_set_resid(sc, res_count);
 929                 else
 930                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 931         }
 932 out:
 933         ISCSI_DBG_SESSION(session, "cmd rsp done [sc %p res %d itt 0x%x]\n",
 934                           sc, sc->result, task->itt);
 935         conn->scsirsp_pdus_cnt++;
 936         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 937 }
 938
 939 /**
 940  * iscsi_data_in_rsp - SCSI Data-In Response processing
 941  * @conn: iscsi connection
 942  * @hdr:  iscsi pdu
 943  * @task: scsi command task
 944  **/
 945 static void
 946 iscsi_data_in_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 947                   struct iscsi_task *task)
 948 {
 949         struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)hdr;
 950         struct scsi_cmnd *sc = task->sc;
 951
 952         if (!(rhdr->flags & ISCSI_FLAG_DATA_STATUS))
 953                 return;
 954
 955         iscsi_update_cmdsn(conn->session, (struct iscsi_nopin *)hdr);
 956         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 957         conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 958         if (rhdr->flags & (ISCSI_FLAG_DATA_UNDERFLOW |
 959                            ISCSI_FLAG_DATA_OVERFLOW)) {
 960                 int res_count = be32_to_cpu(rhdr->residual_count);
 961
 962                 if (res_count > 0 &&
 963                     (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
 964                      res_count <= scsi_in(sc)->length))
 965                         scsi_in(sc)->resid = res_count;
 966                 else
 967                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 968         }
 969
 970         ISCSI_DBG_SESSION(conn->session, "data in with status done "
 971                           "[sc %p res %d itt 0x%x]\n",
 972                           sc, sc->result, task->itt);
 973         conn->scsirsp_pdus_cnt++;
 974         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 975 }
 976
 977 static void iscsi_tmf_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
 978 {
 979         struct iscsi_tm_rsp *tmf = (struct iscsi_tm_rsp *)hdr;
 980
 981         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 982         conn->tmfrsp_pdus_cnt++;
 983
 984         if (conn->tmf_state != TMF_QUEUED)
 985                 return;
 986
 987         if (tmf->response == ISCSI_TMF_RSP_COMPLETE)
 988                 conn->tmf_state = TMF_SUCCESS;
 989         else if (tmf->response == ISCSI_TMF_RSP_NO_TASK)
 990                 conn->tmf_state = TMF_NOT_FOUND;
 991         else
 992                 conn->tmf_state = TMF_FAILED;
 993         wake_up(&conn->ehwait);
 994 }
 995
 996 static int iscsi_send_nopout(struct iscsi_conn *conn, struct iscsi_nopin *rhdr)
 997 {
 998         struct iscsi_nopout hdr;
 999         struct iscsi_task *task;
1000
1001         if (!rhdr && conn->ping_task)
1002                 return -EINVAL;
1003
1004         memset(&hdr, 0, sizeof(struct iscsi_nopout));
1005         hdr.opcode = ISCSI_OP_NOOP_OUT | ISCSI_OP_IMMEDIATE;
1006         hdr.flags = ISCSI_FLAG_CMD_FINAL;
1007
1008         if (rhdr) {
1009                 hdr.lun = rhdr->lun;
1010                 hdr.ttt = rhdr->ttt;
1011                 hdr.itt = RESERVED_ITT;
1012         } else
1013                 hdr.ttt = RESERVED_ITT;
1014
1015         task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)&hdr, NULL, 0);
1016         if (!task) {
1017                 iscsi_conn_printk(KERN_ERR, conn, "Could not send nopout\n");
1018                 return -EIO;
1019         } else if (!rhdr) {
1020                 /* only track our nops */
1021                 conn->ping_task = task;
1022                 conn->last_ping = jiffies;
1023         }
1024
1025         return 0;
1026 }
1027
1028 static int iscsi_nop_out_rsp(struct iscsi_task *task,
1029                              struct iscsi_nopin *nop, char *data, int datalen)
1030 {
1031         struct iscsi_conn *conn = task->conn;
1032         int rc = 0;
1033
1034         if (conn->ping_task != task) {
1035                 /*
1036                  * If this is not in response to one of our
1037                  * nops then it must be from userspace.
1038                  */
1039                 if (iscsi_recv_pdu(conn->cls_conn, (struct iscsi_hdr *)nop,
1040                                    data, datalen))
1041                         rc = ISCSI_ERR_CONN_FAILED;
1042         } else
1043                 mod_timer(&conn->transport_timer, jiffies + conn->recv_timeout);
1044         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1045         return rc;
1046 }
1047
1048 static int iscsi_handle_reject(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1049                                char *data, int datalen)
1050 {
1051         struct iscsi_reject *reject = (struct iscsi_reject *)hdr;
1052         struct iscsi_hdr rejected_pdu;
1053         int opcode, rc = 0;
1054
1055         conn->exp_statsn = be32_to_cpu(reject->statsn) + 1;
1056
1057         if (ntoh24(reject->dlength) > datalen ||
1058             ntoh24(reject->dlength) < sizeof(struct iscsi_hdr)) {
1059                 iscsi_conn_printk(KERN_ERR, conn, "Cannot handle rejected "
1060                                   "pdu. Invalid data length (pdu dlength "
1061                                   "%u, datalen %d\n", ntoh24(reject->dlength),
1062                                   datalen);
1063                 return ISCSI_ERR_PROTO;
1064         }
1065         memcpy(&rejected_pdu, data, sizeof(struct iscsi_hdr));
1066         opcode = rejected_pdu.opcode & ISCSI_OPCODE_MASK;
1067
1068         switch (reject->reason) {
1069         case ISCSI_REASON_DATA_DIGEST_ERROR:
1070                 iscsi_conn_printk(KERN_ERR, conn,
1071                                   "pdu (op 0x%x itt 0x%x) rejected "
1072                                   "due to DataDigest error.\n",
1073                                   opcode, rejected_pdu.itt);
1074                 break;
1075         case ISCSI_REASON_IMM_CMD_REJECT:
1076                 iscsi_conn_printk(KERN_ERR, conn,
1077                                   "pdu (op 0x%x itt 0x%x) rejected. Too many "
1078                                   "immediate commands.\n",
1079                                   opcode, rejected_pdu.itt);
1080                 /*
1081                  * We only send one TMF at a time so if the target could not
1082                  * handle it, then it should get fixed (RFC mandates that
1083                  * a target can handle one immediate TMF per conn).
1084                  *
1085                  * For nops-outs, we could have sent more than one if
1086                  * the target is sending us lots of nop-ins
1087                  */
1088                 if (opcode != ISCSI_OP_NOOP_OUT)
1089                         return 0;
1090
1091                 if (rejected_pdu.itt == cpu_to_be32(ISCSI_RESERVED_TAG)) {
1092                         /*
1093                          * nop-out in response to target's nop-out rejected.
1094                          * Just resend.
1095                          */
1096                         /* In RX path we are under back lock */
1097                         spin_unlock(&conn->session->back_lock);
1098                         spin_lock(&conn->session->frwd_lock);
1099                         iscsi_send_nopout(conn,
1100                                           (struct iscsi_nopin*)&rejected_pdu);
1101                         spin_unlock(&conn->session->frwd_lock);
1102                         spin_lock(&conn->session->back_lock);
1103                 } else {
1104                         struct iscsi_task *task;
1105                         /*
1106                          * Our nop as ping got dropped. We know the target
1107                          * and transport are ok so just clean up
1108                          */
1109                         task = iscsi_itt_to_task(conn, rejected_pdu.itt);
1110                         if (!task) {
1111                                 iscsi_conn_printk(KERN_ERR, conn,
1112                                                  "Invalid pdu reject. Could "
1113                                                  "not lookup rejected task.\n");
1114                                 rc = ISCSI_ERR_BAD_ITT;
1115                         } else
1116                                 rc = iscsi_nop_out_rsp(task,
1117                                         (struct iscsi_nopin*)&rejected_pdu,
1118                                         NULL, 0);
1119                 }
1120                 break;
1121         default:
1122                 iscsi_conn_printk(KERN_ERR, conn,
1123                                   "pdu (op 0x%x itt 0x%x) rejected. Reason "
1124                                   "code 0x%x\n", rejected_pdu.opcode,
1125                                   rejected_pdu.itt, reject->reason);
1126                 break;
1127         }
1128         return rc;
1129 }
1130
1131 /**
1132  * iscsi_itt_to_task - look up task by itt
1133  * @conn: iscsi connection
1134  * @itt: itt
1135  *
1136  * This should be used for mgmt tasks like login and nops, or if
1137  * the LDD's itt space does not include the session age.
1138  *
1139  * The session back_lock must be held.
1140  */
1141 struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *conn, itt_t itt)
1142 {
1143         struct iscsi_session *session = conn->session;
1144         int i;
1145
1146         if (itt == RESERVED_ITT)
1147                 return NULL;
1148
1149         if (session->tt->parse_pdu_itt)
1150                 session->tt->parse_pdu_itt(conn, itt, &i, NULL);
1151         else
1152                 i = get_itt(itt);
1153         if (i >= session->cmds_max)
1154                 return NULL;
1155
1156         return session->cmds[i];
1157 }
1158 EXPORT_SYMBOL_GPL(iscsi_itt_to_task);
1159
1160 /**
1161  * __iscsi_complete_pdu - complete pdu
1162  * @conn: iscsi conn
1163  * @hdr: iscsi header
1164  * @data: data buffer
1165  * @datalen: len of data buffer
1166  *
1167  * Completes pdu processing by freeing any resources allocated at
1168  * queuecommand or send generic. session back_lock must be held and verify
1169  * itt must have been called.
1170  */
1171 int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1172                          char *data, int datalen)
1173 {
1174         struct iscsi_session *session = conn->session;
1175         int opcode = hdr->opcode & ISCSI_OPCODE_MASK, rc = 0;
1176         struct iscsi_task *task;
1177         uint32_t itt;
1178
1179         conn->last_recv = jiffies;
1180         rc = iscsi_verify_itt(conn, hdr->itt);
1181         if (rc)
1182                 return rc;
1183
1184         if (hdr->itt != RESERVED_ITT)
1185                 itt = get_itt(hdr->itt);
1186         else
1187                 itt = ~0U;
1188
1189         ISCSI_DBG_SESSION(session, "[op 0x%x cid %d itt 0x%x len %d]\n",
1190                           opcode, conn->id, itt, datalen);
1191
1192         if (itt == ~0U) {
1193                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1194
1195                 switch(opcode) {
1196                 case ISCSI_OP_NOOP_IN:
1197                         if (datalen) {
1198                                 rc = ISCSI_ERR_PROTO;
1199                                 break;
1200                         }
1201
1202                         if (hdr->ttt == cpu_to_be32(ISCSI_RESERVED_TAG))
1203                                 break;
1204
1205                         /* In RX path we are under back lock */
1206                         spin_unlock(&session->back_lock);
1207                         spin_lock(&session->frwd_lock);
1208                         iscsi_send_nopout(conn, (struct iscsi_nopin*)hdr);
1209                         spin_unlock(&session->frwd_lock);
1210                         spin_lock(&session->back_lock);
1211                         break;
1212                 case ISCSI_OP_REJECT:
1213                         rc = iscsi_handle_reject(conn, hdr, data, datalen);
1214                         break;
1215                 case ISCSI_OP_ASYNC_EVENT:
1216                         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1217                         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
1218                                 rc = ISCSI_ERR_CONN_FAILED;
1219                         break;
1220                 default:
1221                         rc = ISCSI_ERR_BAD_OPCODE;
1222                         break;
1223                 }
1224                 goto out;
1225         }
1226
1227         switch(opcode) {
1228         case ISCSI_OP_SCSI_CMD_RSP:
1229         case ISCSI_OP_SCSI_DATA_IN:
1230                 task = iscsi_itt_to_ctask(conn, hdr->itt);
1231                 if (!task)
1232                         return ISCSI_ERR_BAD_ITT;
1233                 task->last_xfer = jiffies;
1234                 break;
1235         case ISCSI_OP_R2T:
1236                 /*
1237                  * LLD handles R2Ts if they need to.
1238                  */
1239                 return 0;
1240         case ISCSI_OP_LOGOUT_RSP:
1241         case ISCSI_OP_LOGIN_RSP:
1242         case ISCSI_OP_TEXT_RSP:
1243         case ISCSI_OP_SCSI_TMFUNC_RSP:
1244         case ISCSI_OP_NOOP_IN:
1245                 task = iscsi_itt_to_task(conn, hdr->itt);
1246                 if (!task)
1247                         return ISCSI_ERR_BAD_ITT;
1248                 break;
1249         default:
1250                 return ISCSI_ERR_BAD_OPCODE;
1251         }
1252
1253         switch(opcode) {
1254         case ISCSI_OP_SCSI_CMD_RSP:
1255                 iscsi_scsi_cmd_rsp(conn, hdr, task, data, datalen);
1256                 break;
1257         case ISCSI_OP_SCSI_DATA_IN:
1258                 iscsi_data_in_rsp(conn, hdr, task);
1259                 break;
1260         case ISCSI_OP_LOGOUT_RSP:
1261                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1262                 if (datalen) {
1263                         rc = ISCSI_ERR_PROTO;
1264                         break;
1265                 }
1266                 conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1267                 goto recv_pdu;
1268         case ISCSI_OP_LOGIN_RSP:
1269         case ISCSI_OP_TEXT_RSP:
1270                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1271                 /*
1272                  * login related PDU's exp_statsn is handled in
1273                  * userspace
1274                  */
1275                 goto recv_pdu;
1276         case ISCSI_OP_SCSI_TMFUNC_RSP:
1277                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1278                 if (datalen) {
1279                         rc = ISCSI_ERR_PROTO;
1280                         break;
1281                 }
1282
1283                 iscsi_tmf_rsp(conn, hdr);
1284                 iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1285                 break;
1286         case ISCSI_OP_NOOP_IN:
1287                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1288                 if (hdr->ttt != cpu_to_be32(ISCSI_RESERVED_TAG) || datalen) {
1289                         rc = ISCSI_ERR_PROTO;
1290                         break;
1291                 }
1292                 conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1293
1294                 rc = iscsi_nop_out_rsp(task, (struct iscsi_nopin*)hdr,
1295                                        data, datalen);
1296                 break;
1297         default:
1298                 rc = ISCSI_ERR_BAD_OPCODE;
1299                 break;
1300         }
1301
1302 out:
1303         return rc;
1304 recv_pdu:
1305         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
1306                 rc = ISCSI_ERR_CONN_FAILED;
1307         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1308         return rc;
1309 }
1310 EXPORT_SYMBOL_GPL(__iscsi_complete_pdu);
1311
1312 int iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1313                        char *data, int datalen)
1314 {
1315         int rc;
1316
1317         spin_lock(&conn->session->back_lock);
1318         rc = __iscsi_complete_pdu(conn, hdr, data, datalen);
1319         spin_unlock(&conn->session->back_lock);
1320         return rc;
1321 }
1322 EXPORT_SYMBOL_GPL(iscsi_complete_pdu);
1323
1324 int iscsi_verify_itt(struct iscsi_conn *conn, itt_t itt)
1325 {
1326         struct iscsi_session *session = conn->session;
1327         int age = 0, i = 0;
1328
1329         if (itt == RESERVED_ITT)
1330                 return 0;
1331
1332         if (session->tt->parse_pdu_itt)
1333                 session->tt->parse_pdu_itt(conn, itt, &i, &age);
1334         else {
1335                 i = get_itt(itt);
1336                 age = ((__force u32)itt >> ISCSI_AGE_SHIFT) & ISCSI_AGE_MASK;
1337         }
1338
1339         if (age != session->age) {
1340                 iscsi_conn_printk(KERN_ERR, conn,
1341                                   "received itt %x expected session age (%x)\n",
1342                                   (__force u32)itt, session->age);
1343                 return ISCSI_ERR_BAD_ITT;
1344         }
1345
1346         if (i >= session->cmds_max) {
1347                 iscsi_conn_printk(KERN_ERR, conn,
1348                                   "received invalid itt index %u (max cmds "
1349                                    "%u.\n", i, session->cmds_max);
1350                 return ISCSI_ERR_BAD_ITT;
1351         }
1352         return 0;
1353 }
1354 EXPORT_SYMBOL_GPL(iscsi_verify_itt);
1355
1356 /**
1357  * iscsi_itt_to_ctask - look up ctask by itt
1358  * @conn: iscsi connection
1359  * @itt: itt
1360  *
1361  * This should be used for cmd tasks.
1362  *
1363  * The session back_lock must be held.
1364  */
1365 struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *conn, itt_t itt)
1366 {
1367         struct iscsi_task *task;
1368
1369         if (iscsi_verify_itt(conn, itt))
1370                 return NULL;
1371
1372         task = iscsi_itt_to_task(conn, itt);
1373         if (!task || !task->sc)
1374                 return NULL;
1375
1376         if (task->sc->SCp.phase != conn->session->age) {
1377                 iscsi_session_printk(KERN_ERR, conn->session,
1378                                   "task's session age %d, expected %d\n",
1379                                   task->sc->SCp.phase, conn->session->age);
1380                 return NULL;
1381         }
1382
1383         return task;
1384 }
1385 EXPORT_SYMBOL_GPL(iscsi_itt_to_ctask);
1386
1387 void iscsi_session_failure(struct iscsi_session *session,
1388                            enum iscsi_err err)
1389 {
1390         struct iscsi_conn *conn;
1391         struct device *dev;
1392
1393         spin_lock_bh(&session->frwd_lock);
1394         conn = session->leadconn;
1395         if (session->state == ISCSI_STATE_TERMINATE || !conn) {
1396                 spin_unlock_bh(&session->frwd_lock);
1397                 return;
1398         }
1399
1400         dev = get_device(&conn->cls_conn->dev);
1401         spin_unlock_bh(&session->frwd_lock);
1402         if (!dev)
1403                 return;
1404         /*
1405          * if the host is being removed bypass the connection
1406          * recovery initialization because we are going to kill
1407          * the session.
1408          */
1409         if (err == ISCSI_ERR_INVALID_HOST)
1410                 iscsi_conn_error_event(conn->cls_conn, err);
1411         else
1412                 iscsi_conn_failure(conn, err);
1413         put_device(dev);
1414 }
1415 EXPORT_SYMBOL_GPL(iscsi_session_failure);
1416
1417 void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err)
1418 {
1419         struct iscsi_session *session = conn->session;
1420
1421         spin_lock_bh(&session->frwd_lock);
1422         if (session->state == ISCSI_STATE_FAILED) {
1423                 spin_unlock_bh(&session->frwd_lock);
1424                 return;
1425         }
1426
1427         if (conn->stop_stage == 0)
1428                 session->state = ISCSI_STATE_FAILED;
1429         spin_unlock_bh(&session->frwd_lock);
1430
1431         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1432         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
1433         iscsi_conn_error_event(conn->cls_conn, err);
1434 }
1435 EXPORT_SYMBOL_GPL(iscsi_conn_failure);
1436
1437 static int iscsi_check_cmdsn_window_closed(struct iscsi_conn *conn)
1438 {
1439         struct iscsi_session *session = conn->session;
1440
1441         /*
1442          * Check for iSCSI window and take care of CmdSN wrap-around
1443          */
1444         if (!iscsi_sna_lte(session->queued_cmdsn, session->max_cmdsn)) {
1445                 ISCSI_DBG_SESSION(session, "iSCSI CmdSN closed. ExpCmdSn "
1446                                   "%u MaxCmdSN %u CmdSN %u/%u\n",
1447                                   session->exp_cmdsn, session->max_cmdsn,
1448                                   session->cmdsn, session->queued_cmdsn);
1449                 return -ENOSPC;
1450         }
1451         return 0;
1452 }
1453
1454 static int iscsi_xmit_task(struct iscsi_conn *conn)
1455 {
1456         struct iscsi_task *task = conn->task;
1457         int rc;
1458
1459         if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx))
1460                 return -ENODATA;
1461
1462         __iscsi_get_task(task);
1463         spin_unlock_bh(&conn->session->frwd_lock);
1464         rc = conn->session->tt->xmit_task(task);
1465         spin_lock_bh(&conn->session->frwd_lock);
1466         if (!rc) {
1467                 /* done with this task */
1468                 task->last_xfer = jiffies;
1469                 conn->task = NULL;
1470         }
1471         /* regular RX path uses back_lock */
1472         spin_lock(&conn->session->back_lock);
1473         __iscsi_put_task(task);
1474         spin_unlock(&conn->session->back_lock);
1475         return rc;
1476 }
1477
1478 /**
1479  * iscsi_requeue_task - requeue task to run from session workqueue
1480  * @task: task to requeue
1481  *
1482  * LLDs that need to run a task from the session workqueue should call
1483  * this. The session frwd_lock must be held. This should only be called
1484  * by software drivers.
1485  */
1486 void iscsi_requeue_task(struct iscsi_task *task)
1487 {
1488         struct iscsi_conn *conn = task->conn;
1489
1490         /*
1491          * this may be on the requeue list already if the xmit_task callout
1492          * is handling the r2ts while we are adding new ones
1493          */
1494         spin_lock_bh(&conn->taskqueuelock);
1495         if (list_empty(&task->running))
1496                 list_add_tail(&task->running, &conn->requeue);
1497         spin_unlock_bh(&conn->taskqueuelock);
1498         iscsi_conn_queue_work(conn);
1499 }
1500 EXPORT_SYMBOL_GPL(iscsi_requeue_task);
1501
1502 /**
1503  * iscsi_data_xmit - xmit any command into the scheduled connection
1504  * @conn: iscsi connection
1505  *
1506  * Notes:
1507  *      The function can return -EAGAIN in which case the caller must
1508  *      re-schedule it again later or recover. '0' return code means
1509  *      successful xmit.
1510  **/
1511 static int iscsi_data_xmit(struct iscsi_conn *conn)
1512 {
1513         struct iscsi_task *task;
1514         int rc = 0;
1515
1516         spin_lock_bh(&conn->session->frwd_lock);
1517         if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx)) {
1518                 ISCSI_DBG_SESSION(conn->session, "Tx suspended!\n");
1519                 spin_unlock_bh(&conn->session->frwd_lock);
1520                 return -ENODATA;
1521         }
1522
1523         if (conn->task) {
1524                 rc = iscsi_xmit_task(conn);
1525                 if (rc)
1526                         goto done;
1527         }
1528
1529         /*
1530          * process mgmt pdus like nops before commands since we should
1531          * only have one nop-out as a ping from us and targets should not
1532          * overflow us with nop-ins
1533          */
1534         spin_lock_bh(&conn->taskqueuelock);
1535 check_mgmt:
1536         while (!list_empty(&conn->mgmtqueue)) {
1537                 conn->task = list_entry(conn->mgmtqueue.next,
1538                                          struct iscsi_task, running);
1539                 list_del_init(&conn->task->running);
1540                 spin_unlock_bh(&conn->taskqueuelock);
1541                 if (iscsi_prep_mgmt_task(conn, conn->task)) {
1542                         /* regular RX path uses back_lock */
1543                         spin_lock_bh(&conn->session->back_lock);
1544                         __iscsi_put_task(conn->task);
1545                         spin_unlock_bh(&conn->session->back_lock);
1546                         conn->task = NULL;
1547                         spin_lock_bh(&conn->taskqueuelock);
1548                         continue;
1549                 }
1550                 rc = iscsi_xmit_task(conn);
1551                 if (rc)
1552                         goto done;
1553                 spin_lock_bh(&conn->taskqueuelock);
1554         }
1555
1556         /* process pending command queue */
1557         while (!list_empty(&conn->cmdqueue)) {
1558                 conn->task = list_entry(conn->cmdqueue.next, struct iscsi_task,
1559                                         running);
1560                 list_del_init(&conn->task->running);
1561                 spin_unlock_bh(&conn->taskqueuelock);
1562                 if (conn->session->state == ISCSI_STATE_LOGGING_OUT) {
1563                         fail_scsi_task(conn->task, DID_IMM_RETRY);
1564                         spin_lock_bh(&conn->taskqueuelock);
1565                         continue;
1566                 }
1567                 rc = iscsi_prep_scsi_cmd_pdu(conn->task);
1568                 if (rc) {
1569                         if (rc == -ENOMEM || rc == -EACCES) {
1570                                 spin_lock_bh(&conn->taskqueuelock);
1571                                 list_add_tail(&conn->task->running,
1572                                               &conn->cmdqueue);
1573                                 conn->task = NULL;
1574                                 spin_unlock_bh(&conn->taskqueuelock);
1575                                 goto done;
1576                         } else
1577                                 fail_scsi_task(conn->task, DID_ABORT);
1578                         spin_lock_bh(&conn->taskqueuelock);
1579                         continue;
1580                 }
1581                 rc = iscsi_xmit_task(conn);
1582                 if (rc)
1583                         goto done;
1584                 /*
1585                  * we could continuously get new task requests so
1586                  * we need to check the mgmt queue for nops that need to
1587                  * be sent to aviod starvation
1588                  */
1589                 spin_lock_bh(&conn->taskqueuelock);
1590                 if (!list_empty(&conn->mgmtqueue))
1591                         goto check_mgmt;
1592         }
1593
1594         while (!list_empty(&conn->requeue)) {
1595                 /*
1596                  * we always do fastlogout - conn stop code will clean up.
1597                  */
1598                 if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
1599                         break;
1600
1601                 task = list_entry(conn->requeue.next, struct iscsi_task,
1602                                   running);
1603                 if (iscsi_check_tmf_restrictions(task, ISCSI_OP_SCSI_DATA_OUT))
1604                         break;
1605
1606                 conn->task = task;
1607                 list_del_init(&conn->task->running);
1608                 conn->task->state = ISCSI_TASK_RUNNING;
1609                 spin_unlock_bh(&conn->taskqueuelock);
1610                 rc = iscsi_xmit_task(conn);
1611                 if (rc)
1612                         goto done;
1613                 spin_lock_bh(&conn->taskqueuelock);
1614                 if (!list_empty(&conn->mgmtqueue))
1615                         goto check_mgmt;
1616         }
1617         spin_unlock_bh(&conn->taskqueuelock);
1618         spin_unlock_bh(&conn->session->frwd_lock);
1619         return -ENODATA;
1620
1621 done:
1622         spin_unlock_bh(&conn->session->frwd_lock);
1623         return rc;
1624 }
1625
1626 static void iscsi_xmitworker(struct work_struct *work)
1627 {
1628         struct iscsi_conn *conn =
1629                 container_of(work, struct iscsi_conn, xmitwork);
1630         int rc;
1631         /*
1632          * serialize Xmit worker on a per-connection basis.
1633          */
1634         do {
1635                 rc = iscsi_data_xmit(conn);
1636         } while (rc >= 0 || rc == -EAGAIN);
1637 }
1638
1639 static inline struct iscsi_task *iscsi_alloc_task(struct iscsi_conn *conn,
1640                                                   struct scsi_cmnd *sc)
1641 {
1642         struct iscsi_task *task;
1643
1644         if (!kfifo_out(&conn->session->cmdpool.queue,
1645                          (void *) &task, sizeof(void *)))
1646                 return NULL;
1647
1648         sc->SCp.phase = conn->session->age;
1649         sc->SCp.ptr = (char *) task;
1650
1651         refcount_set(&task->refcount, 1);
1652         task->state = ISCSI_TASK_PENDING;
1653         task->conn = conn;
1654         task->sc = sc;
1655         task->have_checked_conn = false;
1656         task->last_timeout = jiffies;
1657         task->last_xfer = jiffies;
1658         task->protected = false;
1659         INIT_LIST_HEAD(&task->running);
1660         return task;
1661 }
1662
1663 enum {
1664         FAILURE_BAD_HOST = 1,
1665         FAILURE_SESSION_FAILED,
1666         FAILURE_SESSION_FREED,
1667         FAILURE_WINDOW_CLOSED,
1668         FAILURE_OOM,
1669         FAILURE_SESSION_TERMINATE,
1670         FAILURE_SESSION_IN_RECOVERY,
1671         FAILURE_SESSION_RECOVERY_TIMEOUT,
1672         FAILURE_SESSION_LOGGING_OUT,
1673         FAILURE_SESSION_NOT_READY,
1674 };
1675
1676 int iscsi_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *sc)
1677 {
1678         struct iscsi_cls_session *cls_session;
1679         struct iscsi_host *ihost;
1680         int reason = 0;
1681         struct iscsi_session *session;
1682         struct iscsi_conn *conn;
1683         struct iscsi_task *task = NULL;
1684
1685         sc->result = 0;
1686         sc->SCp.ptr = NULL;
1687
1688         ihost = shost_priv(host);
1689
1690         cls_session = starget_to_session(scsi_target(sc->device));
1691         session = cls_session->dd_data;
1692         spin_lock_bh(&session->frwd_lock);
1693
1694         reason = iscsi_session_chkready(cls_session);
1695         if (reason) {
1696                 sc->result = reason;
1697                 goto fault;
1698         }
1699
1700         if (session->state != ISCSI_STATE_LOGGED_IN) {
1701                 /*
1702                  * to handle the race between when we set the recovery state
1703                  * and block the session we requeue here (commands could
1704                  * be entering our queuecommand while a block is starting
1705                  * up because the block code is not locked)
1706                  */
1707                 switch (session->state) {
1708                 case ISCSI_STATE_FAILED:
1709                         /*
1710                          * cmds should fail during shutdown, if the session
1711                          * state is bad, allowing completion to happen
1712                          */
1713                         if (unlikely(system_state != SYSTEM_RUNNING)) {
1714                                 reason = FAILURE_SESSION_FAILED;
1715                                 sc->result = DID_NO_CONNECT << 16;
1716                                 break;
1717                         }
1718                         /* fall through */
1719                 case ISCSI_STATE_IN_RECOVERY:
1720                         reason = FAILURE_SESSION_IN_RECOVERY;
1721                         sc->result = DID_IMM_RETRY << 16;
1722                         break;
1723                 case ISCSI_STATE_LOGGING_OUT:
1724                         reason = FAILURE_SESSION_LOGGING_OUT;
1725                         sc->result = DID_IMM_RETRY << 16;
1726                         break;
1727                 case ISCSI_STATE_RECOVERY_FAILED:
1728                         reason = FAILURE_SESSION_RECOVERY_TIMEOUT;
1729                         sc->result = DID_TRANSPORT_FAILFAST << 16;
1730                         break;
1731                 case ISCSI_STATE_TERMINATE:
1732                         reason = FAILURE_SESSION_TERMINATE;
1733                         sc->result = DID_NO_CONNECT << 16;
1734                         break;
1735                 default:
1736                         reason = FAILURE_SESSION_FREED;
1737                         sc->result = DID_NO_CONNECT << 16;
1738                 }
1739                 goto fault;
1740         }
1741
1742         conn = session->leadconn;
1743         if (!conn) {
1744                 reason = FAILURE_SESSION_FREED;
1745                 sc->result = DID_NO_CONNECT << 16;
1746                 goto fault;
1747         }
1748
1749         if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx)) {
1750                 reason = FAILURE_SESSION_IN_RECOVERY;
1751                 sc->result = DID_REQUEUE << 16;
1752                 goto fault;
1753         }
1754
1755         if (iscsi_check_cmdsn_window_closed(conn)) {
1756                 reason = FAILURE_WINDOW_CLOSED;
1757                 goto reject;
1758         }
1759
1760         task = iscsi_alloc_task(conn, sc);
1761         if (!task) {
1762                 reason = FAILURE_OOM;
1763                 goto reject;
1764         }
1765
1766         if (!ihost->workq) {
1767                 reason = iscsi_prep_scsi_cmd_pdu(task);
1768                 if (reason) {
1769                         if (reason == -ENOMEM ||  reason == -EACCES) {
1770                                 reason = FAILURE_OOM;
1771                                 goto prepd_reject;
1772                         } else {
1773                                 sc->result = DID_ABORT << 16;
1774                                 goto prepd_fault;
1775                         }
1776                 }
1777                 if (session->tt->xmit_task(task)) {
1778                         session->cmdsn--;
1779                         reason = FAILURE_SESSION_NOT_READY;
1780                         goto prepd_reject;
1781                 }
1782         } else {
1783                 spin_lock_bh(&conn->taskqueuelock);
1784                 list_add_tail(&task->running, &conn->cmdqueue);
1785                 spin_unlock_bh(&conn->taskqueuelock);
1786                 iscsi_conn_queue_work(conn);
1787         }
1788
1789         session->queued_cmdsn++;
1790         spin_unlock_bh(&session->frwd_lock);
1791         return 0;
1792
1793 prepd_reject:
1794         iscsi_complete_task(task, ISCSI_TASK_REQUEUE_SCSIQ);
1795 reject:
1796         spin_unlock_bh(&session->frwd_lock);
1797         ISCSI_DBG_SESSION(session, "cmd 0x%x rejected (%d)\n",
1798                           sc->cmnd[0], reason);
1799         return SCSI_MLQUEUE_TARGET_BUSY;
1800
1801 prepd_fault:
1802         iscsi_complete_task(task, ISCSI_TASK_REQUEUE_SCSIQ);
1803 fault:
1804         spin_unlock_bh(&session->frwd_lock);
1805         ISCSI_DBG_SESSION(session, "iscsi: cmd 0x%x is not queued (%d)\n",
1806                           sc->cmnd[0], reason);
1807         if (!scsi_bidi_cmnd(sc))
1808                 scsi_set_resid(sc, scsi_bufflen(sc));
1809         else {
1810                 scsi_out(sc)->resid = scsi_out(sc)->length;
1811                 scsi_in(sc)->resid = scsi_in(sc)->length;
1812         }
1813         sc->scsi_done(sc);
1814         return 0;
1815 }
1816 EXPORT_SYMBOL_GPL(iscsi_queuecommand);
1817
1818 int iscsi_target_alloc(struct scsi_target *starget)
1819 {
1820         struct iscsi_cls_session *cls_session = starget_to_session(starget);
1821         struct iscsi_session *session = cls_session->dd_data;
1822
1823         starget->can_queue = session->scsi_cmds_max;
1824         return 0;
1825 }
1826 EXPORT_SYMBOL_GPL(iscsi_target_alloc);
1827
1828 static void iscsi_tmf_timedout(struct timer_list *t)
1829 {
1830         struct iscsi_conn *conn = from_timer(conn, t, tmf_timer);
1831         struct iscsi_session *session = conn->session;
1832
1833         spin_lock(&session->frwd_lock);
1834         if (conn->tmf_state == TMF_QUEUED) {
1835                 conn->tmf_state = TMF_TIMEDOUT;
1836                 ISCSI_DBG_EH(session, "tmf timedout\n");
1837                 /* unblock eh_abort() */
1838                 wake_up(&conn->ehwait);
1839         }
1840         spin_unlock(&session->frwd_lock);
1841 }
1842
1843 static int iscsi_exec_task_mgmt_fn(struct iscsi_conn *conn,
1844                                    struct iscsi_tm *hdr, int age,
1845                                    int timeout)
1846         __must_hold(&session->frwd_lock)
1847 {
1848         struct iscsi_session *session = conn->session;
1849         struct iscsi_task *task;
1850
1851         task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)hdr,
1852                                       NULL, 0);
1853         if (!task) {
1854                 spin_unlock_bh(&session->frwd_lock);
1855                 iscsi_conn_printk(KERN_ERR, conn, "Could not send TMF.\n");
1856                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1857                 spin_lock_bh(&session->frwd_lock);
1858                 return -EPERM;
1859         }
1860         conn->tmfcmd_pdus_cnt++;
1861         conn->tmf_timer.expires = timeout * HZ + jiffies;
1862         add_timer(&conn->tmf_timer);
1863         ISCSI_DBG_EH(session, "tmf set timeout\n");
1864
1865         spin_unlock_bh(&session->frwd_lock);
1866         mutex_unlock(&session->eh_mutex);
1867
1868         /*
1869          * block eh thread until:
1870          *
1871          * 1) tmf response
1872          * 2) tmf timeout
1873          * 3) session is terminated or restarted or userspace has
1874          * given up on recovery
1875          */
1876         wait_event_interruptible(conn->ehwait, age != session->age ||
1877                                  session->state != ISCSI_STATE_LOGGED_IN ||
1878                                  conn->tmf_state != TMF_QUEUED);
1879         if (signal_pending(current))
1880                 flush_signals(current);
1881         del_timer_sync(&conn->tmf_timer);
1882
1883         mutex_lock(&session->eh_mutex);
1884         spin_lock_bh(&session->frwd_lock);
1885         /* if the session drops it will clean up the task */
1886         if (age != session->age ||
1887             session->state != ISCSI_STATE_LOGGED_IN)
1888                 return -ENOTCONN;
1889         return 0;
1890 }
1891
1892 /*
1893  * Fail commands. session lock held and recv side suspended and xmit
1894  * thread flushed
1895  */
1896 static void fail_scsi_tasks(struct iscsi_conn *conn, u64 lun, int error)
1897 {
1898         struct iscsi_task *task;
1899         int i;
1900
1901         for (i = 0; i < conn->session->cmds_max; i++) {
1902                 task = conn->session->cmds[i];
1903                 if (!task->sc || task->state == ISCSI_TASK_FREE)
1904                         continue;
1905
1906                 if (lun != -1 && lun != task->sc->device->lun)
1907                         continue;
1908
1909                 ISCSI_DBG_SESSION(conn->session,
1910                                   "failing sc %p itt 0x%x state %d\n",
1911                                   task->sc, task->itt, task->state);
1912                 fail_scsi_task(task, error);
1913         }
1914 }
1915
1916 /**
1917  * iscsi_suspend_queue - suspend iscsi_queuecommand
1918  * @conn: iscsi conn to stop queueing IO on
1919  *
1920  * This grabs the session frwd_lock to make sure no one is in
1921  * xmit_task/queuecommand, and then sets suspend to prevent
1922  * new commands from being queued. This only needs to be called
1923  * by offload drivers that need to sync a path like ep disconnect
1924  * with the iscsi_queuecommand/xmit_task. To start IO again libiscsi
1925  * will call iscsi_start_tx and iscsi_unblock_session when in FFP.
1926  */
1927 void iscsi_suspend_queue(struct iscsi_conn *conn)
1928 {
1929         spin_lock_bh(&conn->session->frwd_lock);
1930         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1931         spin_unlock_bh(&conn->session->frwd_lock);
1932 }
1933 EXPORT_SYMBOL_GPL(iscsi_suspend_queue);
1934
1935 /**
1936  * iscsi_suspend_tx - suspend iscsi_data_xmit
1937  * @conn: iscsi conn tp stop processing IO on.
1938  *
1939  * This function sets the suspend bit to prevent iscsi_data_xmit
1940  * from sending new IO, and if work is queued on the xmit thread
1941  * it will wait for it to be completed.
1942  */
1943 void iscsi_suspend_tx(struct iscsi_conn *conn)
1944 {
1945         struct Scsi_Host *shost = conn->session->host;
1946         struct iscsi_host *ihost = shost_priv(shost);
1947
1948         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1949         if (ihost->workq)
1950                 flush_workqueue(ihost->workq);
1951 }
1952 EXPORT_SYMBOL_GPL(iscsi_suspend_tx);
1953
1954 static void iscsi_start_tx(struct iscsi_conn *conn)
1955 {
1956         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1957         iscsi_conn_queue_work(conn);
1958 }
1959
1960 /*
1961  * We want to make sure a ping is in flight. It has timed out.
1962  * And we are not busy processing a pdu that is making
1963  * progress but got started before the ping and is taking a while
1964  * to complete so the ping is just stuck behind it in a queue.
1965  */
1966 static int iscsi_has_ping_timed_out(struct iscsi_conn *conn)
1967 {
1968         if (conn->ping_task &&
1969             time_before_eq(conn->last_recv + (conn->recv_timeout * HZ) +
1970                            (conn->ping_timeout * HZ), jiffies))
1971                 return 1;
1972         else
1973                 return 0;
1974 }
1975
1976 enum blk_eh_timer_return iscsi_eh_cmd_timed_out(struct scsi_cmnd *sc)
1977 {
1978         enum blk_eh_timer_return rc = BLK_EH_DONE;
1979         struct iscsi_task *task = NULL, *running_task;
1980         struct iscsi_cls_session *cls_session;
1981         struct iscsi_session *session;
1982         struct iscsi_conn *conn;
1983         int i;
1984
1985         cls_session = starget_to_session(scsi_target(sc->device));
1986         session = cls_session->dd_data;
1987
1988         ISCSI_DBG_EH(session, "scsi cmd %p timedout\n", sc);
1989
1990         spin_lock(&session->frwd_lock);
1991         task = (struct iscsi_task *)sc->SCp.ptr;
1992         if (!task) {
1993                 /*
1994                  * Raced with completion. Blk layer has taken ownership
1995                  * so let timeout code complete it now.
1996                  */
1997                 rc = BLK_EH_DONE;
1998                 goto done;
1999         }
2000
2001         if (session->state != ISCSI_STATE_LOGGED_IN) {
2002                 /*
2003                  * During shutdown, if session is prematurely disconnected,
2004                  * recovery won't happen and there will be hung cmds. Not
2005                  * handling cmds would trigger EH, also bad in this case.
2006                  * Instead, handle cmd, allow completion to happen and let
2007                  * upper layer to deal with the result.
2008                  */
2009                 if (unlikely(system_state != SYSTEM_RUNNING)) {
2010                         sc->result = DID_NO_CONNECT << 16;
2011                         ISCSI_DBG_EH(session, "sc on shutdown, handled\n");
2012                         rc = BLK_EH_DONE;
2013                         goto done;
2014                 }
2015                 /*
2016                  * We are probably in the middle of iscsi recovery so let
2017                  * that complete and handle the error.
2018                  */
2019                 rc = BLK_EH_RESET_TIMER;
2020                 goto done;
2021         }
2022
2023         conn = session->leadconn;
2024         if (!conn) {
2025                 /* In the middle of shuting down */
2026                 rc = BLK_EH_RESET_TIMER;
2027                 goto done;
2028         }
2029
2030         /*
2031          * If we have sent (at least queued to the network layer) a pdu or
2032          * recvd one for the task since the last timeout ask for
2033          * more time. If on the next timeout we have not made progress
2034          * we can check if it is the task or connection when we send the
2035          * nop as a ping.
2036          */
2037         if (time_after(task->last_xfer, task->last_timeout)) {
2038                 ISCSI_DBG_EH(session, "Command making progress. Asking "
2039                              "scsi-ml for more time to complete. "
2040                              "Last data xfer at %lu. Last timeout was at "
2041                              "%lu\n.", task->last_xfer, task->last_timeout);
2042                 task->have_checked_conn = false;
2043                 rc = BLK_EH_RESET_TIMER;
2044                 goto done;
2045         }
2046
2047         if (!conn->recv_timeout && !conn->ping_timeout)
2048                 goto done;
2049         /*
2050          * if the ping timedout then we are in the middle of cleaning up
2051          * and can let the iscsi eh handle it
2052          */
2053         if (iscsi_has_ping_timed_out(conn)) {
2054                 rc = BLK_EH_RESET_TIMER;
2055                 goto done;
2056         }
2057
2058         for (i = 0; i < conn->session->cmds_max; i++) {
2059                 running_task = conn->session->cmds[i];
2060                 if (!running_task->sc || running_task == task ||
2061                      running_task->state != ISCSI_TASK_RUNNING)
2062                         continue;
2063
2064                 /*
2065                  * Only check if cmds started before this one have made
2066                  * progress, or this could never fail
2067                  */
2068                 if (time_after(running_task->sc->jiffies_at_alloc,
2069                                task->sc->jiffies_at_alloc))
2070                         continue;
2071
2072                 if (time_after(running_task->last_xfer, task->last_timeout)) {
2073                         /*
2074                          * This task has not made progress, but a task
2075                          * started before us has transferred data since
2076                          * we started/last-checked. We could be queueing
2077                          * too many tasks or the LU is bad.
2078                          *
2079                          * If the device is bad the cmds ahead of us on
2080                          * other devs will complete, and this loop will
2081                          * eventually fail starting the scsi eh.
2082                          */
2083                         ISCSI_DBG_EH(session, "Command has not made progress "
2084                                      "but commands ahead of it have. "
2085                                      "Asking scsi-ml for more time to "
2086                                      "complete. Our last xfer vs running task "
2087                                      "last xfer %lu/%lu. Last check %lu.\n",
2088                                      task->last_xfer, running_task->last_xfer,
2089                                      task->last_timeout);
2090                         rc = BLK_EH_RESET_TIMER;
2091                         goto done;
2092                 }
2093         }
2094
2095         /* Assumes nop timeout is shorter than scsi cmd timeout */
2096         if (task->have_checked_conn)
2097                 goto done;
2098
2099         /*
2100          * Checking the transport already or nop from a cmd timeout still
2101          * running
2102          */
2103         if (conn->ping_task) {
2104                 task->have_checked_conn = true;
2105                 rc = BLK_EH_RESET_TIMER;
2106                 goto done;
2107         }
2108
2109         /* Make sure there is a transport check done */
2110         iscsi_send_nopout(conn, NULL);
2111         task->have_checked_conn = true;
2112         rc = BLK_EH_RESET_TIMER;
2113
2114 done:
2115         if (task)
2116                 task->last_timeout = jiffies;
2117         spin_unlock(&session->frwd_lock);
2118         ISCSI_DBG_EH(session, "return %s\n", rc == BLK_EH_RESET_TIMER ?
2119                      "timer reset" : "shutdown or nh");
2120         return rc;
2121 }
2122 EXPORT_SYMBOL_GPL(iscsi_eh_cmd_timed_out);
2123
2124 static void iscsi_check_transport_timeouts(struct timer_list *t)
2125 {
2126         struct iscsi_conn *conn = from_timer(conn, t, transport_timer);
2127         struct iscsi_session *session = conn->session;
2128         unsigned long recv_timeout, next_timeout = 0, last_recv;
2129
2130         spin_lock(&session->frwd_lock);
2131         if (session->state != ISCSI_STATE_LOGGED_IN)
2132                 goto done;
2133
2134         recv_timeout = conn->recv_timeout;
2135         if (!recv_timeout)
2136                 goto done;
2137
2138         recv_timeout *= HZ;
2139         last_recv = conn->last_recv;
2140
2141         if (iscsi_has_ping_timed_out(conn)) {
2142                 iscsi_conn_printk(KERN_ERR, conn, "ping timeout of %d secs "
2143                                   "expired, recv timeout %d, last rx %lu, "
2144                                   "last ping %lu, now %lu\n",
2145                                   conn->ping_timeout, conn->recv_timeout,
2146                                   last_recv, conn->last_ping, jiffies);
2147                 spin_unlock(&session->frwd_lock);
2148                 iscsi_conn_failure(conn, ISCSI_ERR_NOP_TIMEDOUT);
2149                 return;
2150         }
2151
2152         if (time_before_eq(last_recv + recv_timeout, jiffies)) {
2153                 /* send a ping to try to provoke some traffic */
2154                 ISCSI_DBG_CONN(conn, "Sending nopout as ping\n");
2155                 if (iscsi_send_nopout(conn, NULL))
2156                         next_timeout = jiffies + (1 * HZ);
2157                 else
2158                         next_timeout = conn->last_ping + (conn->ping_timeout * HZ);
2159         } else
2160                 next_timeout = last_recv + recv_timeout;
2161
2162         ISCSI_DBG_CONN(conn, "Setting next tmo %lu\n", next_timeout);
2163         mod_timer(&conn->transport_timer, next_timeout);
2164 done:
2165         spin_unlock(&session->frwd_lock);
2166 }
2167
2168 static void iscsi_prep_abort_task_pdu(struct iscsi_task *task,
2169                                       struct iscsi_tm *hdr)
2170 {
2171         memset(hdr, 0, sizeof(*hdr));
2172         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2173         hdr->flags = ISCSI_TM_FUNC_ABORT_TASK & ISCSI_FLAG_TM_FUNC_MASK;
2174         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2175         hdr->lun = task->lun;
2176         hdr->rtt = task->hdr_itt;
2177         hdr->refcmdsn = task->cmdsn;
2178 }
2179
2180 int iscsi_eh_abort(struct scsi_cmnd *sc)
2181 {
2182         struct iscsi_cls_session *cls_session;
2183         struct iscsi_session *session;
2184         struct iscsi_conn *conn;
2185         struct iscsi_task *task;
2186         struct iscsi_tm *hdr;
2187         int age;
2188
2189         cls_session = starget_to_session(scsi_target(sc->device));
2190         session = cls_session->dd_data;
2191
2192         ISCSI_DBG_EH(session, "aborting sc %p\n", sc);
2193
2194         mutex_lock(&session->eh_mutex);
2195         spin_lock_bh(&session->frwd_lock);
2196         /*
2197          * if session was ISCSI_STATE_IN_RECOVERY then we may not have
2198          * got the command.
2199          */
2200         if (!sc->SCp.ptr) {
2201                 ISCSI_DBG_EH(session, "sc never reached iscsi layer or "
2202                                       "it completed.\n");
2203                 spin_unlock_bh(&session->frwd_lock);
2204                 mutex_unlock(&session->eh_mutex);
2205                 return SUCCESS;
2206         }
2207
2208         /*
2209          * If we are not logged in or we have started a new session
2210          * then let the host reset code handle this
2211          */
2212         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN ||
2213             sc->SCp.phase != session->age) {
2214                 spin_unlock_bh(&session->frwd_lock);
2215                 mutex_unlock(&session->eh_mutex);
2216                 ISCSI_DBG_EH(session, "failing abort due to dropped "
2217                                   "session.\n");
2218                 return FAILED;
2219         }
2220
2221         conn = session->leadconn;
2222         conn->eh_abort_cnt++;
2223         age = session->age;
2224
2225         task = (struct iscsi_task *)sc->SCp.ptr;
2226         ISCSI_DBG_EH(session, "aborting [sc %p itt 0x%x]\n",
2227                      sc, task->itt);
2228
2229         /* task completed before time out */
2230         if (!task->sc) {
2231                 ISCSI_DBG_EH(session, "sc completed while abort in progress\n");
2232                 goto success;
2233         }
2234
2235         if (task->state == ISCSI_TASK_PENDING) {
2236                 fail_scsi_task(task, DID_ABORT);
2237                 goto success;
2238         }
2239
2240         /* only have one tmf outstanding at a time */
2241         if (conn->tmf_state != TMF_INITIAL)
2242                 goto failed;
2243         conn->tmf_state = TMF_QUEUED;
2244
2245         hdr = &conn->tmhdr;
2246         iscsi_prep_abort_task_pdu(task, hdr);
2247
2248         if (iscsi_exec_task_mgmt_fn(conn, hdr, age, session->abort_timeout))
2249                 goto failed;
2250
2251         switch (conn->tmf_state) {
2252         case TMF_SUCCESS:
2253                 spin_unlock_bh(&session->frwd_lock);
2254                 /*
2255                  * stop tx side incase the target had sent a abort rsp but
2256                  * the initiator was still writing out data.
2257                  */
2258                 iscsi_suspend_tx(conn);
2259                 /*
2260                  * we do not stop the recv side because targets have been
2261                  * good and have never sent us a successful tmf response
2262                  * then sent more data for the cmd.
2263                  */
2264                 spin_lock_bh(&session->frwd_lock);
2265                 fail_scsi_task(task, DID_ABORT);
2266                 conn->tmf_state = TMF_INITIAL;
2267                 memset(hdr, 0, sizeof(*hdr));
2268                 spin_unlock_bh(&session->frwd_lock);
2269                 iscsi_start_tx(conn);
2270                 goto success_unlocked;
2271         case TMF_TIMEDOUT:
2272                 spin_unlock_bh(&session->frwd_lock);
2273                 iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2274                 goto failed_unlocked;
2275         case TMF_NOT_FOUND:
2276                 if (!sc->SCp.ptr) {
2277                         conn->tmf_state = TMF_INITIAL;
2278                         memset(hdr, 0, sizeof(*hdr));
2279                         /* task completed before tmf abort response */
2280                         ISCSI_DBG_EH(session, "sc completed while abort in "
2281                                               "progress\n");
2282                         goto success;
2283                 }
2284                 /* fall through */
2285         default:
2286                 conn->tmf_state = TMF_INITIAL;
2287                 goto failed;
2288         }
2289
2290 success:
2291         spin_unlock_bh(&session->frwd_lock);
2292 success_unlocked:
2293         ISCSI_DBG_EH(session, "abort success [sc %p itt 0x%x]\n",
2294                      sc, task->itt);
2295         mutex_unlock(&session->eh_mutex);
2296         return SUCCESS;
2297
2298 failed:
2299         spin_unlock_bh(&session->frwd_lock);
2300 failed_unlocked:
2301         ISCSI_DBG_EH(session, "abort failed [sc %p itt 0x%x]\n", sc,
2302                      task ? task->itt : 0);
2303         mutex_unlock(&session->eh_mutex);
2304         return FAILED;
2305 }
2306 EXPORT_SYMBOL_GPL(iscsi_eh_abort);
2307
2308 static void iscsi_prep_lun_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
2309 {
2310         memset(hdr, 0, sizeof(*hdr));
2311         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2312         hdr->flags = ISCSI_TM_FUNC_LOGICAL_UNIT_RESET & ISCSI_FLAG_TM_FUNC_MASK;
2313         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2314         int_to_scsilun(sc->device->lun, &hdr->lun);
2315         hdr->rtt = RESERVED_ITT;
2316 }
2317
2318 int iscsi_eh_device_reset(struct scsi_cmnd *sc)
2319 {
2320         struct iscsi_cls_session *cls_session;
2321         struct iscsi_session *session;
2322         struct iscsi_conn *conn;
2323         struct iscsi_tm *hdr;
2324         int rc = FAILED;
2325
2326         cls_session = starget_to_session(scsi_target(sc->device));
2327         session = cls_session->dd_data;
2328
2329         ISCSI_DBG_EH(session, "LU Reset [sc %p lun %llu]\n", sc,
2330                      sc->device->lun);
2331
2332         mutex_lock(&session->eh_mutex);
2333         spin_lock_bh(&session->frwd_lock);
2334         /*
2335          * Just check if we are not logged in. We cannot check for
2336          * the phase because the reset could come from a ioctl.
2337          */
2338         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
2339                 goto unlock;
2340         conn = session->leadconn;
2341
2342         /* only have one tmf outstanding at a time */
2343         if (conn->tmf_state != TMF_INITIAL)
2344                 goto unlock;
2345         conn->tmf_state = TMF_QUEUED;
2346
2347         hdr = &conn->tmhdr;
2348         iscsi_prep_lun_reset_pdu(sc, hdr);
2349
2350         if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
2351                                     session->lu_reset_timeout)) {
2352                 rc = FAILED;
2353                 goto unlock;
2354         }
2355
2356         switch (conn->tmf_state) {
2357         case TMF_SUCCESS:
2358                 break;
2359         case TMF_TIMEDOUT:
2360                 spin_unlock_bh(&session->frwd_lock);
2361                 iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2362                 goto done;
2363         default:
2364                 conn->tmf_state = TMF_INITIAL;
2365                 goto unlock;
2366         }
2367
2368         rc = SUCCESS;
2369         spin_unlock_bh(&session->frwd_lock);
2370
2371         iscsi_suspend_tx(conn);
2372
2373         spin_lock_bh(&session->frwd_lock);
2374         memset(hdr, 0, sizeof(*hdr));
2375         fail_scsi_tasks(conn, sc->device->lun, DID_ERROR);
2376         conn->tmf_state = TMF_INITIAL;
2377         spin_unlock_bh(&session->frwd_lock);
2378
2379         iscsi_start_tx(conn);
2380         goto done;
2381
2382 unlock:
2383         spin_unlock_bh(&session->frwd_lock);
2384 done:
2385         ISCSI_DBG_EH(session, "dev reset result = %s\n",
2386                      rc == SUCCESS ? "SUCCESS" : "FAILED");
2387         mutex_unlock(&session->eh_mutex);
2388         return rc;
2389 }
2390 EXPORT_SYMBOL_GPL(iscsi_eh_device_reset);
2391
2392 void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
2393 {
2394         struct iscsi_session *session = cls_session->dd_data;
2395
2396         spin_lock_bh(&session->frwd_lock);
2397         if (session->state != ISCSI_STATE_LOGGED_IN) {
2398                 session->state = ISCSI_STATE_RECOVERY_FAILED;
2399                 if (session->leadconn)
2400                         wake_up(&session->leadconn->ehwait);
2401         }
2402         spin_unlock_bh(&session->frwd_lock);
2403 }
2404 EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
2405
2406 /**
2407  * iscsi_eh_session_reset - drop session and attempt relogin
2408  * @sc: scsi command
2409  *
2410  * This function will wait for a relogin, session termination from
2411  * userspace, or a recovery/replacement timeout.
2412  */
2413 int iscsi_eh_session_reset(struct scsi_cmnd *sc)
2414 {
2415         struct iscsi_cls_session *cls_session;
2416         struct iscsi_session *session;
2417         struct iscsi_conn *conn;
2418
2419         cls_session = starget_to_session(scsi_target(sc->device));
2420         session = cls_session->dd_data;
2421         conn = session->leadconn;
2422
2423         mutex_lock(&session->eh_mutex);
2424         spin_lock_bh(&session->frwd_lock);
2425         if (session->state == ISCSI_STATE_TERMINATE) {
2426 failed:
2427                 ISCSI_DBG_EH(session,
2428                              "failing session reset: Could not log back into "
2429                              "%s [age %d]\n", session->targetname,
2430                              session->age);
2431                 spin_unlock_bh(&session->frwd_lock);
2432                 mutex_unlock(&session->eh_mutex);
2433                 return FAILED;
2434         }
2435
2436         spin_unlock_bh(&session->frwd_lock);
2437         mutex_unlock(&session->eh_mutex);
2438         /*
2439          * we drop the lock here but the leadconn cannot be destoyed while
2440          * we are in the scsi eh
2441          */
2442         iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2443
2444         ISCSI_DBG_EH(session, "wait for relogin\n");
2445         wait_event_interruptible(conn->ehwait,
2446                                  session->state == ISCSI_STATE_TERMINATE ||
2447                                  session->state == ISCSI_STATE_LOGGED_IN ||
2448                                  session->state == ISCSI_STATE_RECOVERY_FAILED);
2449         if (signal_pending(current))
2450                 flush_signals(current);
2451
2452         mutex_lock(&session->eh_mutex);
2453         spin_lock_bh(&session->frwd_lock);
2454         if (session->state == ISCSI_STATE_LOGGED_IN) {
2455                 ISCSI_DBG_EH(session,
2456                              "session reset succeeded for %s,%s\n",
2457                              session->targetname, conn->persistent_address);
2458         } else
2459                 goto failed;
2460         spin_unlock_bh(&session->frwd_lock);
2461         mutex_unlock(&session->eh_mutex);
2462         return SUCCESS;
2463 }
2464 EXPORT_SYMBOL_GPL(iscsi_eh_session_reset);
2465
2466 static void iscsi_prep_tgt_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
2467 {
2468         memset(hdr, 0, sizeof(*hdr));
2469         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2470         hdr->flags = ISCSI_TM_FUNC_TARGET_WARM_RESET & ISCSI_FLAG_TM_FUNC_MASK;
2471         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2472         hdr->rtt = RESERVED_ITT;
2473 }
2474
2475 /**
2476  * iscsi_eh_target_reset - reset target
2477  * @sc: scsi command
2478  *
2479  * This will attempt to send a warm target reset.
2480  */
2481 static int iscsi_eh_target_reset(struct scsi_cmnd *sc)
2482 {
2483         struct iscsi_cls_session *cls_session;
2484         struct iscsi_session *session;
2485         struct iscsi_conn *conn;
2486         struct iscsi_tm *hdr;
2487         int rc = FAILED;
2488
2489         cls_session = starget_to_session(scsi_target(sc->device));
2490         session = cls_session->dd_data;
2491
2492         ISCSI_DBG_EH(session, "tgt Reset [sc %p tgt %s]\n", sc,
2493                      session->targetname);
2494
2495         mutex_lock(&session->eh_mutex);
2496         spin_lock_bh(&session->frwd_lock);
2497         /*
2498          * Just check if we are not logged in. We cannot check for
2499          * the phase because the reset could come from a ioctl.
2500          */
2501         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
2502                 goto unlock;
2503         conn = session->leadconn;
2504
2505         /* only have one tmf outstanding at a time */
2506         if (conn->tmf_state != TMF_INITIAL)
2507                 goto unlock;
2508         conn->tmf_state = TMF_QUEUED;
2509
2510         hdr = &conn->tmhdr;
2511         iscsi_prep_tgt_reset_pdu(sc, hdr);
2512
2513         if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
2514                                     session->tgt_reset_timeout)) {
2515                 rc = FAILED;
2516                 goto unlock;
2517         }
2518
2519         switch (conn->tmf_state) {
2520         case TMF_SUCCESS:
2521                 break;
2522         case TMF_TIMEDOUT:
2523                 spin_unlock_bh(&session->frwd_lock);
2524                 iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2525                 goto done;
2526         default:
2527                 conn->tmf_state = TMF_INITIAL;
2528                 goto unlock;
2529         }
2530
2531         rc = SUCCESS;
2532         spin_unlock_bh(&session->frwd_lock);
2533
2534         iscsi_suspend_tx(conn);
2535
2536         spin_lock_bh(&session->frwd_lock);
2537         memset(hdr, 0, sizeof(*hdr));
2538         fail_scsi_tasks(conn, -1, DID_ERROR);
2539         conn->tmf_state = TMF_INITIAL;
2540         spin_unlock_bh(&session->frwd_lock);
2541
2542         iscsi_start_tx(conn);
2543         goto done;
2544
2545 unlock:
2546         spin_unlock_bh(&session->frwd_lock);
2547 done:
2548         ISCSI_DBG_EH(session, "tgt %s reset result = %s\n", session->targetname,
2549                      rc == SUCCESS ? "SUCCESS" : "FAILED");
2550         mutex_unlock(&session->eh_mutex);
2551         return rc;
2552 }
2553
2554 /**
2555  * iscsi_eh_recover_target - reset target and possibly the session
2556  * @sc: scsi command
2557  *
2558  * This will attempt to send a warm target reset. If that fails,
2559  * we will escalate to ERL0 session recovery.
2560  */
2561 int iscsi_eh_recover_target(struct scsi_cmnd *sc)
2562 {
2563         int rc;
2564
2565         rc = iscsi_eh_target_reset(sc);
2566         if (rc == FAILED)
2567                 rc = iscsi_eh_session_reset(sc);
2568         return rc;
2569 }
2570 EXPORT_SYMBOL_GPL(iscsi_eh_recover_target);
2571
2572 /*
2573  * Pre-allocate a pool of @max items of @item_size. By default, the pool
2574  * should be accessed via kfifo_{get,put} on q->queue.
2575  * Optionally, the caller can obtain the array of object pointers
2576  * by passing in a non-NULL @items pointer
2577  */
2578 int
2579 iscsi_pool_init(struct iscsi_pool *q, int max, void ***items, int item_size)
2580 {
2581         int i, num_arrays = 1;
2582
2583         memset(q, 0, sizeof(*q));
2584
2585         q->max = max;
2586
2587         /* If the user passed an items pointer, he wants a copy of
2588          * the array. */
2589         if (items)
2590                 num_arrays++;
2591         q->pool = kvcalloc(num_arrays * max, sizeof(void *), GFP_KERNEL);
2592         if (q->pool == NULL)
2593                 return -ENOMEM;
2594
2595         kfifo_init(&q->queue, (void*)q->pool, max * sizeof(void*));
2596
2597         for (i = 0; i < max; i++) {
2598                 q->pool[i] = kzalloc(item_size, GFP_KERNEL);
2599                 if (q->pool[i] == NULL) {
2600                         q->max = i;
2601                         goto enomem;
2602                 }
2603                 kfifo_in(&q->queue, (void*)&q->pool[i], sizeof(void*));
2604         }
2605
2606         if (items) {
2607                 *items = q->pool + max;
2608                 memcpy(*items, q->pool, max * sizeof(void *));
2609         }
2610
2611         return 0;
2612
2613 enomem:
2614         iscsi_pool_free(q);
2615         return -ENOMEM;
2616 }
2617 EXPORT_SYMBOL_GPL(iscsi_pool_init);
2618
2619 void iscsi_pool_free(struct iscsi_pool *q)
2620 {
2621         int i;
2622
2623         for (i = 0; i < q->max; i++)
2624                 kfree(q->pool[i]);
2625         kvfree(q->pool);
2626 }
2627 EXPORT_SYMBOL_GPL(iscsi_pool_free);
2628
2629 /**
2630  * iscsi_host_add - add host to system
2631  * @shost: scsi host
2632  * @pdev: parent device
2633  *
2634  * This should be called by partial offload and software iscsi drivers
2635  * to add a host to the system.
2636  */
2637 int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev)
2638 {
2639         if (!shost->can_queue)
2640                 shost->can_queue = ISCSI_DEF_XMIT_CMDS_MAX;
2641
2642         if (!shost->cmd_per_lun)
2643                 shost->cmd_per_lun = ISCSI_DEF_CMD_PER_LUN;
2644
2645         return scsi_add_host(shost, pdev);
2646 }
2647 EXPORT_SYMBOL_GPL(iscsi_host_add);
2648
2649 /**
2650  * iscsi_host_alloc - allocate a host and driver data
2651  * @sht: scsi host template
2652  * @dd_data_size: driver host data size
2653  * @xmit_can_sleep: bool indicating if LLD will queue IO from a work queue
2654  *
2655  * This should be called by partial offload and software iscsi drivers.
2656  * To access the driver specific memory use the iscsi_host_priv() macro.
2657  */
2658 struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
2659                                    int dd_data_size, bool xmit_can_sleep)
2660 {
2661         struct Scsi_Host *shost;
2662         struct iscsi_host *ihost;
2663
2664         shost = scsi_host_alloc(sht, sizeof(struct iscsi_host) + dd_data_size);
2665         if (!shost)
2666                 return NULL;
2667         ihost = shost_priv(shost);
2668
2669         if (xmit_can_sleep) {
2670                 snprintf(ihost->workq_name, sizeof(ihost->workq_name),
2671                         "iscsi_q_%d", shost->host_no);
2672                 ihost->workq = create_singlethread_workqueue(ihost->workq_name);
2673                 if (!ihost->workq)
2674                         goto free_host;
2675         }
2676
2677         spin_lock_init(&ihost->lock);
2678         ihost->state = ISCSI_HOST_SETUP;
2679         ihost->num_sessions = 0;
2680         init_waitqueue_head(&ihost->session_removal_wq);
2681         return shost;
2682
2683 free_host:
2684         scsi_host_put(shost);
2685         return NULL;
2686 }
2687 EXPORT_SYMBOL_GPL(iscsi_host_alloc);
2688
2689 static void iscsi_notify_host_removed(struct iscsi_cls_session *cls_session)
2690 {
2691         iscsi_session_failure(cls_session->dd_data, ISCSI_ERR_INVALID_HOST);
2692 }
2693
2694 /**
2695  * iscsi_host_remove - remove host and sessions
2696  * @shost: scsi host
2697  *
2698  * If there are any sessions left, this will initiate the removal and wait
2699  * for the completion.
2700  */
2701 void iscsi_host_remove(struct Scsi_Host *shost)
2702 {
2703         struct iscsi_host *ihost = shost_priv(shost);
2704         unsigned long flags;
2705
2706         spin_lock_irqsave(&ihost->lock, flags);
2707         ihost->state = ISCSI_HOST_REMOVED;
2708         spin_unlock_irqrestore(&ihost->lock, flags);
2709
2710         iscsi_host_for_each_session(shost, iscsi_notify_host_removed);
2711         wait_event_interruptible(ihost->session_removal_wq,
2712                                  ihost->num_sessions == 0);
2713         if (signal_pending(current))
2714                 flush_signals(current);
2715
2716         scsi_remove_host(shost);
2717         if (ihost->workq)
2718                 destroy_workqueue(ihost->workq);
2719 }
2720 EXPORT_SYMBOL_GPL(iscsi_host_remove);
2721
2722 void iscsi_host_free(struct Scsi_Host *shost)
2723 {
2724         struct iscsi_host *ihost = shost_priv(shost);
2725
2726         kfree(ihost->netdev);
2727         kfree(ihost->hwaddress);
2728         kfree(ihost->initiatorname);
2729         scsi_host_put(shost);
2730 }
2731 EXPORT_SYMBOL_GPL(iscsi_host_free);
2732
2733 static void iscsi_host_dec_session_cnt(struct Scsi_Host *shost)
2734 {
2735         struct iscsi_host *ihost = shost_priv(shost);
2736         unsigned long flags;
2737
2738         shost = scsi_host_get(shost);
2739         if (!shost) {
2740                 printk(KERN_ERR "Invalid state. Cannot notify host removal "
2741                       "of session teardown event because host already "
2742                       "removed.\n");
2743                 return;
2744         }
2745
2746         spin_lock_irqsave(&ihost->lock, flags);
2747         ihost->num_sessions--;
2748         if (ihost->num_sessions == 0)
2749                 wake_up(&ihost->session_removal_wq);
2750         spin_unlock_irqrestore(&ihost->lock, flags);
2751         scsi_host_put(shost);
2752 }
2753
2754 /**
2755  * iscsi_session_setup - create iscsi cls session and host and session
2756  * @iscsit: iscsi transport template
2757  * @shost: scsi host
2758  * @cmds_max: session can queue
2759  * @dd_size: private driver data size, added to session allocation size
2760  * @cmd_task_size: LLD task private data size
2761  * @initial_cmdsn: initial CmdSN
2762  * @id: target ID to add to this session
2763  *
2764  * This can be used by software iscsi_transports that allocate
2765  * a session per scsi host.
2766  *
2767  * Callers should set cmds_max to the largest total numer (mgmt + scsi) of
2768  * tasks they support. The iscsi layer reserves ISCSI_MGMT_CMDS_MAX tasks
2769  * for nop handling and login/logout requests.
2770  */
2771 struct iscsi_cls_session *
2772 iscsi_session_setup(struct iscsi_transport *iscsit, struct Scsi_Host *shost,
2773                     uint16_t cmds_max, int dd_size, int cmd_task_size,
2774                     uint32_t initial_cmdsn, unsigned int id)
2775 {
2776         struct iscsi_host *ihost = shost_priv(shost);
2777         struct iscsi_session *session;
2778         struct iscsi_cls_session *cls_session;
2779         int cmd_i, scsi_cmds, total_cmds = cmds_max;
2780         unsigned long flags;
2781
2782         spin_lock_irqsave(&ihost->lock, flags);
2783         if (ihost->state == ISCSI_HOST_REMOVED) {
2784                 spin_unlock_irqrestore(&ihost->lock, flags);
2785                 return NULL;
2786         }
2787         ihost->num_sessions++;
2788         spin_unlock_irqrestore(&ihost->lock, flags);
2789
2790         if (!total_cmds)
2791                 total_cmds = ISCSI_DEF_XMIT_CMDS_MAX;
2792         /*
2793          * The iscsi layer needs some tasks for nop handling and tmfs,
2794          * so the cmds_max must at least be greater than ISCSI_MGMT_CMDS_MAX
2795          * + 1 command for scsi IO.
2796          */
2797         if (total_cmds < ISCSI_TOTAL_CMDS_MIN) {
2798                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2799                        "must be a power of two that is at least %d.\n",
2800                        total_cmds, ISCSI_TOTAL_CMDS_MIN);
2801                 goto dec_session_count;
2802         }
2803
2804         if (total_cmds > ISCSI_TOTAL_CMDS_MAX) {
2805                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2806                        "must be a power of 2 less than or equal to %d.\n",
2807                        cmds_max, ISCSI_TOTAL_CMDS_MAX);
2808                 total_cmds = ISCSI_TOTAL_CMDS_MAX;
2809         }
2810
2811         if (!is_power_of_2(total_cmds)) {
2812                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2813                        "must be a power of 2.\n", total_cmds);
2814                 total_cmds = rounddown_pow_of_two(total_cmds);
2815                 if (total_cmds < ISCSI_TOTAL_CMDS_MIN)
2816                         return NULL;
2817                 printk(KERN_INFO "iscsi: Rounding can_queue to %d.\n",
2818                        total_cmds);
2819         }
2820         scsi_cmds = total_cmds - ISCSI_MGMT_CMDS_MAX;
2821
2822         cls_session = iscsi_alloc_session(shost, iscsit,
2823                                           sizeof(struct iscsi_session) +
2824                                           dd_size);
2825         if (!cls_session)
2826                 goto dec_session_count;
2827         session = cls_session->dd_data;
2828         session->cls_session = cls_session;
2829         session->host = shost;
2830         session->state = ISCSI_STATE_FREE;
2831         session->fast_abort = 1;
2832         session->tgt_reset_timeout = 30;
2833         session->lu_reset_timeout = 15;
2834         session->abort_timeout = 10;
2835         session->scsi_cmds_max = scsi_cmds;
2836         session->cmds_max = total_cmds;
2837         session->queued_cmdsn = session->cmdsn = initial_cmdsn;
2838         session->exp_cmdsn = initial_cmdsn + 1;
2839         session->max_cmdsn = initial_cmdsn + 1;
2840         session->max_r2t = 1;
2841         session->tt = iscsit;
2842         session->dd_data = cls_session->dd_data + sizeof(*session);
2843
2844         mutex_init(&session->eh_mutex);
2845         spin_lock_init(&session->frwd_lock);
2846         spin_lock_init(&session->back_lock);
2847
2848         /* initialize SCSI PDU commands pool */
2849         if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
2850                             (void***)&session->cmds,
2851                             cmd_task_size + sizeof(struct iscsi_task)))
2852                 goto cmdpool_alloc_fail;
2853
2854         /* pre-format cmds pool with ITT */
2855         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
2856                 struct iscsi_task *task = session->cmds[cmd_i];
2857
2858                 if (cmd_task_size)
2859                         task->dd_data = &task[1];
2860                 task->itt = cmd_i;
2861                 task->state = ISCSI_TASK_FREE;
2862                 INIT_LIST_HEAD(&task->running);
2863         }
2864
2865         if (!try_module_get(iscsit->owner))
2866                 goto module_get_fail;
2867
2868         if (iscsi_add_session(cls_session, id))
2869                 goto cls_session_fail;
2870
2871         return cls_session;
2872
2873 cls_session_fail:
2874         module_put(iscsit->owner);
2875 module_get_fail:
2876         iscsi_pool_free(&session->cmdpool);
2877 cmdpool_alloc_fail:
2878         iscsi_free_session(cls_session);
2879 dec_session_count:
2880         iscsi_host_dec_session_cnt(shost);
2881         return NULL;
2882 }
2883 EXPORT_SYMBOL_GPL(iscsi_session_setup);
2884
2885 /**
2886  * iscsi_session_teardown - destroy session, host, and cls_session
2887  * @cls_session: iscsi session
2888  */
2889 void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
2890 {
2891         struct iscsi_session *session = cls_session->dd_data;
2892         struct module *owner = cls_session->transport->owner;
2893         struct Scsi_Host *shost = session->host;
2894
2895         iscsi_pool_free(&session->cmdpool);
2896
2897         iscsi_remove_session(cls_session);
2898
2899         kfree(session->password);
2900         kfree(session->password_in);
2901         kfree(session->username);
2902         kfree(session->username_in);
2903         kfree(session->targetname);
2904         kfree(session->targetalias);
2905         kfree(session->initiatorname);
2906         kfree(session->boot_root);
2907         kfree(session->boot_nic);
2908         kfree(session->boot_target);
2909         kfree(session->ifacename);
2910         kfree(session->portal_type);
2911         kfree(session->discovery_parent_type);
2912
2913         iscsi_free_session(cls_session);
2914
2915         iscsi_host_dec_session_cnt(shost);
2916         module_put(owner);
2917 }
2918 EXPORT_SYMBOL_GPL(iscsi_session_teardown);
2919
2920 /**
2921  * iscsi_conn_setup - create iscsi_cls_conn and iscsi_conn
2922  * @cls_session: iscsi_cls_session
2923  * @dd_size: private driver data size
2924  * @conn_idx: cid
2925  */
2926 struct iscsi_cls_conn *
2927 iscsi_conn_setup(struct iscsi_cls_session *cls_session, int dd_size,
2928                  uint32_t conn_idx)
2929 {
2930         struct iscsi_session *session = cls_session->dd_data;
2931         struct iscsi_conn *conn;
2932         struct iscsi_cls_conn *cls_conn;
2933         char *data;
2934
2935         cls_conn = iscsi_create_conn(cls_session, sizeof(*conn) + dd_size,
2936                                      conn_idx);
2937         if (!cls_conn)
2938                 return NULL;
2939         conn = cls_conn->dd_data;
2940         memset(conn, 0, sizeof(*conn) + dd_size);
2941
2942         conn->dd_data = cls_conn->dd_data + sizeof(*conn);
2943         conn->session = session;
2944         conn->cls_conn = cls_conn;
2945         conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
2946         conn->id = conn_idx;
2947         conn->exp_statsn = 0;
2948         conn->tmf_state = TMF_INITIAL;
2949
2950         timer_setup(&conn->transport_timer, iscsi_check_transport_timeouts, 0);
2951
2952         INIT_LIST_HEAD(&conn->mgmtqueue);
2953         INIT_LIST_HEAD(&conn->cmdqueue);
2954         INIT_LIST_HEAD(&conn->requeue);
2955         spin_lock_init(&conn->taskqueuelock);
2956         INIT_WORK(&conn->xmitwork, iscsi_xmitworker);
2957
2958         /* allocate login_task used for the login/text sequences */
2959         spin_lock_bh(&session->frwd_lock);
2960         if (!kfifo_out(&session->cmdpool.queue,
2961                          (void*)&conn->login_task,
2962                          sizeof(void*))) {
2963                 spin_unlock_bh(&session->frwd_lock);
2964                 goto login_task_alloc_fail;
2965         }
2966         spin_unlock_bh(&session->frwd_lock);
2967
2968         data = (char *) __get_free_pages(GFP_KERNEL,
2969                                          get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
2970         if (!data)
2971                 goto login_task_data_alloc_fail;
2972         conn->login_task->data = conn->data = data;
2973
2974         timer_setup(&conn->tmf_timer, iscsi_tmf_timedout, 0);
2975         init_waitqueue_head(&conn->ehwait);
2976
2977         return cls_conn;
2978
2979 login_task_data_alloc_fail:
2980         kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
2981                     sizeof(void*));
2982 login_task_alloc_fail:
2983         iscsi_destroy_conn(cls_conn);
2984         return NULL;
2985 }
2986 EXPORT_SYMBOL_GPL(iscsi_conn_setup);
2987
2988 /**
2989  * iscsi_conn_teardown - teardown iscsi connection
2990  * @cls_conn: iscsi class connection
2991  *
2992  * TODO: we may need to make this into a two step process
2993  * like scsi-mls remove + put host
2994  */
2995 void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
2996 {
2997         struct iscsi_conn *conn = cls_conn->dd_data;
2998         struct iscsi_session *session = conn->session;
2999
3000         del_timer_sync(&conn->transport_timer);
3001
3002         mutex_lock(&session->eh_mutex);
3003         spin_lock_bh(&session->frwd_lock);
3004         conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
3005         if (session->leadconn == conn) {
3006                 /*
3007                  * leading connection? then give up on recovery.
3008                  */
3009                 session->state = ISCSI_STATE_TERMINATE;
3010                 wake_up(&conn->ehwait);
3011         }
3012         spin_unlock_bh(&session->frwd_lock);
3013
3014         /* flush queued up work because we free the connection below */
3015         iscsi_suspend_tx(conn);
3016
3017         spin_lock_bh(&session->frwd_lock);
3018         free_pages((unsigned long) conn->data,
3019                    get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
3020         kfree(conn->persistent_address);
3021         kfree(conn->local_ipaddr);
3022         /* regular RX path uses back_lock */
3023         spin_lock_bh(&session->back_lock);
3024         kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
3025                     sizeof(void*));
3026         spin_unlock_bh(&session->back_lock);
3027         if (session->leadconn == conn)
3028                 session->leadconn = NULL;
3029         spin_unlock_bh(&session->frwd_lock);
3030         mutex_unlock(&session->eh_mutex);
3031
3032         iscsi_destroy_conn(cls_conn);
3033 }
3034 EXPORT_SYMBOL_GPL(iscsi_conn_teardown);
3035
3036 int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
3037 {
3038         struct iscsi_conn *conn = cls_conn->dd_data;
3039         struct iscsi_session *session = conn->session;
3040
3041         if (!session) {
3042                 iscsi_conn_printk(KERN_ERR, conn,
3043                                   "can't start unbound connection\n");
3044                 return -EPERM;
3045         }
3046
3047         if ((session->imm_data_en || !session->initial_r2t_en) &&
3048              session->first_burst > session->max_burst) {
3049                 iscsi_conn_printk(KERN_INFO, conn, "invalid burst lengths: "
3050                                   "first_burst %d max_burst %d\n",
3051                                   session->first_burst, session->max_burst);
3052                 return -EINVAL;
3053         }
3054
3055         if (conn->ping_timeout && !conn->recv_timeout) {
3056                 iscsi_conn_printk(KERN_ERR, conn, "invalid recv timeout of "
3057                                   "zero. Using 5 seconds\n.");
3058                 conn->recv_timeout = 5;
3059         }
3060
3061         if (conn->recv_timeout && !conn->ping_timeout) {
3062                 iscsi_conn_printk(KERN_ERR, conn, "invalid ping timeout of "
3063                                   "zero. Using 5 seconds.\n");
3064                 conn->ping_timeout = 5;
3065         }
3066
3067         spin_lock_bh(&session->frwd_lock);
3068         conn->c_stage = ISCSI_CONN_STARTED;
3069         session->state = ISCSI_STATE_LOGGED_IN;
3070         session->queued_cmdsn = session->cmdsn;
3071
3072         conn->last_recv = jiffies;
3073         conn->last_ping = jiffies;
3074         if (conn->recv_timeout && conn->ping_timeout)
3075                 mod_timer(&conn->transport_timer,
3076                           jiffies + (conn->recv_timeout * HZ));
3077
3078         switch(conn->stop_stage) {
3079         case STOP_CONN_RECOVER:
3080                 /*
3081                  * unblock eh_abort() if it is blocked. re-try all
3082                  * commands after successful recovery
3083                  */
3084                 conn->stop_stage = 0;
3085                 conn->tmf_state = TMF_INITIAL;
3086                 session->age++;
3087                 if (session->age == 16)
3088                         session->age = 0;
3089                 break;
3090         case STOP_CONN_TERM:
3091                 conn->stop_stage = 0;
3092                 break;
3093         default:
3094                 break;
3095         }
3096         spin_unlock_bh(&session->frwd_lock);
3097
3098         iscsi_unblock_session(session->cls_session);
3099         wake_up(&conn->ehwait);
3100         return 0;
3101 }
3102 EXPORT_SYMBOL_GPL(iscsi_conn_start);
3103
3104 static void
3105 fail_mgmt_tasks(struct iscsi_session *session, struct iscsi_conn *conn)
3106 {
3107         struct iscsi_task *task;
3108         int i, state;
3109
3110         for (i = 0; i < conn->session->cmds_max; i++) {
3111                 task = conn->session->cmds[i];
3112                 if (task->sc)
3113                         continue;
3114
3115                 if (task->state == ISCSI_TASK_FREE)
3116                         continue;
3117
3118                 ISCSI_DBG_SESSION(conn->session,
3119                                   "failing mgmt itt 0x%x state %d\n",
3120                                   task->itt, task->state);
3121                 state = ISCSI_TASK_ABRT_SESS_RECOV;
3122                 if (task->state == ISCSI_TASK_PENDING)
3123                         state = ISCSI_TASK_COMPLETED;
3124                 iscsi_complete_task(task, state);
3125
3126         }
3127 }
3128
3129 static void iscsi_start_session_recovery(struct iscsi_session *session,
3130                                          struct iscsi_conn *conn, int flag)
3131 {
3132         int old_stop_stage;
3133
3134         mutex_lock(&session->eh_mutex);
3135         spin_lock_bh(&session->frwd_lock);
3136         if (conn->stop_stage == STOP_CONN_TERM) {
3137                 spin_unlock_bh(&session->frwd_lock);
3138                 mutex_unlock(&session->eh_mutex);
3139                 return;
3140         }
3141
3142         /*
3143          * When this is called for the in_login state, we only want to clean
3144          * up the login task and connection. We do not need to block and set
3145          * the recovery state again
3146          */
3147         if (flag == STOP_CONN_TERM)
3148                 session->state = ISCSI_STATE_TERMINATE;
3149         else if (conn->stop_stage != STOP_CONN_RECOVER)
3150                 session->state = ISCSI_STATE_IN_RECOVERY;
3151
3152         old_stop_stage = conn->stop_stage;
3153         conn->stop_stage = flag;
3154         spin_unlock_bh(&session->frwd_lock);
3155
3156         del_timer_sync(&conn->transport_timer);
3157         iscsi_suspend_tx(conn);
3158
3159         spin_lock_bh(&session->frwd_lock);
3160         conn->c_stage = ISCSI_CONN_STOPPED;
3161         spin_unlock_bh(&session->frwd_lock);
3162
3163         /*
3164          * for connection level recovery we should not calculate
3165          * header digest. conn->hdr_size used for optimization
3166          * in hdr_extract() and will be re-negotiated at
3167          * set_param() time.
3168          */
3169         if (flag == STOP_CONN_RECOVER) {
3170                 conn->hdrdgst_en = 0;
3171                 conn->datadgst_en = 0;
3172                 if (session->state == ISCSI_STATE_IN_RECOVERY &&
3173                     old_stop_stage != STOP_CONN_RECOVER) {
3174                         ISCSI_DBG_SESSION(session, "blocking session\n");
3175                         iscsi_block_session(session->cls_session);
3176                 }
3177         }
3178
3179         /*
3180          * flush queues.
3181          */
3182         spin_lock_bh(&session->frwd_lock);
3183         fail_scsi_tasks(conn, -1, DID_TRANSPORT_DISRUPTED);
3184         fail_mgmt_tasks(session, conn);
3185         memset(&conn->tmhdr, 0, sizeof(conn->tmhdr));
3186         spin_unlock_bh(&session->frwd_lock);
3187         mutex_unlock(&session->eh_mutex);
3188 }
3189
3190 void iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
3191 {
3192         struct iscsi_conn *conn = cls_conn->dd_data;
3193         struct iscsi_session *session = conn->session;
3194
3195         switch (flag) {
3196         case STOP_CONN_RECOVER:
3197         case STOP_CONN_TERM:
3198                 iscsi_start_session_recovery(session, conn, flag);
3199                 break;
3200         default:
3201                 iscsi_conn_printk(KERN_ERR, conn,
3202                                   "invalid stop flag %d\n", flag);
3203         }
3204 }
3205 EXPORT_SYMBOL_GPL(iscsi_conn_stop);
3206
3207 int iscsi_conn_bind(struct iscsi_cls_session *cls_session,
3208                     struct iscsi_cls_conn *cls_conn, int is_leading)
3209 {
3210         struct iscsi_session *session = cls_session->dd_data;
3211         struct iscsi_conn *conn = cls_conn->dd_data;
3212
3213         spin_lock_bh(&session->frwd_lock);
3214         if (is_leading)
3215                 session->leadconn = conn;
3216         spin_unlock_bh(&session->frwd_lock);
3217
3218         /*
3219          * Unblock xmitworker(), Login Phase will pass through.
3220          */
3221         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
3222         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
3223         return 0;
3224 }
3225 EXPORT_SYMBOL_GPL(iscsi_conn_bind);
3226
3227 int iscsi_switch_str_param(char **param, char *new_val_buf)
3228 {
3229         char *new_val;
3230
3231         if (*param) {
3232                 if (!strcmp(*param, new_val_buf))
3233                         return 0;
3234         }
3235
3236         new_val = kstrdup(new_val_buf, GFP_NOIO);
3237         if (!new_val)
3238                 return -ENOMEM;
3239
3240         kfree(*param);
3241         *param = new_val;
3242         return 0;
3243 }
3244 EXPORT_SYMBOL_GPL(iscsi_switch_str_param);
3245
3246 int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
3247                     enum iscsi_param param, char *buf, int buflen)
3248 {
3249         struct iscsi_conn *conn = cls_conn->dd_data;
3250         struct iscsi_session *session = conn->session;
3251         int val;
3252
3253         switch(param) {
3254         case ISCSI_PARAM_FAST_ABORT:
3255                 sscanf(buf, "%d", &session->fast_abort);
3256                 break;
3257         case ISCSI_PARAM_ABORT_TMO:
3258                 sscanf(buf, "%d", &session->abort_timeout);
3259                 break;
3260         case ISCSI_PARAM_LU_RESET_TMO:
3261                 sscanf(buf, "%d", &session->lu_reset_timeout);
3262                 break;
3263         case ISCSI_PARAM_TGT_RESET_TMO:
3264                 sscanf(buf, "%d", &session->tgt_reset_timeout);
3265                 break;
3266         case ISCSI_PARAM_PING_TMO:
3267                 sscanf(buf, "%d", &conn->ping_timeout);
3268                 break;
3269         case ISCSI_PARAM_RECV_TMO:
3270                 sscanf(buf, "%d", &conn->recv_timeout);
3271                 break;
3272         case ISCSI_PARAM_MAX_RECV_DLENGTH:
3273                 sscanf(buf, "%d", &conn->max_recv_dlength);
3274                 break;
3275         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3276                 sscanf(buf, "%d", &conn->max_xmit_dlength);
3277                 break;
3278         case ISCSI_PARAM_HDRDGST_EN:
3279                 sscanf(buf, "%d", &conn->hdrdgst_en);
3280                 break;
3281         case ISCSI_PARAM_DATADGST_EN:
3282                 sscanf(buf, "%d", &conn->datadgst_en);
3283                 break;
3284         case ISCSI_PARAM_INITIAL_R2T_EN:
3285                 sscanf(buf, "%d", &session->initial_r2t_en);
3286                 break;
3287         case ISCSI_PARAM_MAX_R2T:
3288                 sscanf(buf, "%hu", &session->max_r2t);
3289                 break;
3290         case ISCSI_PARAM_IMM_DATA_EN:
3291                 sscanf(buf, "%d", &session->imm_data_en);
3292                 break;
3293         case ISCSI_PARAM_FIRST_BURST:
3294                 sscanf(buf, "%d", &session->first_burst);
3295                 break;
3296         case ISCSI_PARAM_MAX_BURST:
3297                 sscanf(buf, "%d", &session->max_burst);
3298                 break;
3299         case ISCSI_PARAM_PDU_INORDER_EN:
3300                 sscanf(buf, "%d", &session->pdu_inorder_en);
3301                 break;
3302         case ISCSI_PARAM_DATASEQ_INORDER_EN:
3303                 sscanf(buf, "%d", &session->dataseq_inorder_en);
3304                 break;
3305         case ISCSI_PARAM_ERL:
3306                 sscanf(buf, "%d", &session->erl);
3307                 break;
3308         case ISCSI_PARAM_EXP_STATSN:
3309                 sscanf(buf, "%u", &conn->exp_statsn);
3310                 break;
3311         case ISCSI_PARAM_USERNAME:
3312                 return iscsi_switch_str_param(&session->username, buf);
3313         case ISCSI_PARAM_USERNAME_IN:
3314                 return iscsi_switch_str_param(&session->username_in, buf);
3315         case ISCSI_PARAM_PASSWORD:
3316                 return iscsi_switch_str_param(&session->password, buf);
3317         case ISCSI_PARAM_PASSWORD_IN:
3318                 return iscsi_switch_str_param(&session->password_in, buf);
3319         case ISCSI_PARAM_TARGET_NAME:
3320                 return iscsi_switch_str_param(&session->targetname, buf);
3321         case ISCSI_PARAM_TARGET_ALIAS:
3322                 return iscsi_switch_str_param(&session->targetalias, buf);
3323         case ISCSI_PARAM_TPGT:
3324                 sscanf(buf, "%d", &session->tpgt);
3325                 break;
3326         case ISCSI_PARAM_PERSISTENT_PORT:
3327                 sscanf(buf, "%d", &conn->persistent_port);
3328                 break;
3329         case ISCSI_PARAM_PERSISTENT_ADDRESS:
3330                 return iscsi_switch_str_param(&conn->persistent_address, buf);
3331         case ISCSI_PARAM_IFACE_NAME:
3332                 return iscsi_switch_str_param(&session->ifacename, buf);
3333         case ISCSI_PARAM_INITIATOR_NAME:
3334                 return iscsi_switch_str_param(&session->initiatorname, buf);
3335         case ISCSI_PARAM_BOOT_ROOT:
3336                 return iscsi_switch_str_param(&session->boot_root, buf);
3337         case ISCSI_PARAM_BOOT_NIC:
3338                 return iscsi_switch_str_param(&session->boot_nic, buf);
3339         case ISCSI_PARAM_BOOT_TARGET:
3340                 return iscsi_switch_str_param(&session->boot_target, buf);
3341         case ISCSI_PARAM_PORTAL_TYPE:
3342                 return iscsi_switch_str_param(&session->portal_type, buf);
3343         case ISCSI_PARAM_DISCOVERY_PARENT_TYPE:
3344                 return iscsi_switch_str_param(&session->discovery_parent_type,
3345                                               buf);
3346         case ISCSI_PARAM_DISCOVERY_SESS:
3347                 sscanf(buf, "%d", &val);
3348                 session->discovery_sess = !!val;
3349                 break;
3350         case ISCSI_PARAM_LOCAL_IPADDR:
3351                 return iscsi_switch_str_param(&conn->local_ipaddr, buf);
3352         default:
3353                 return -ENOSYS;
3354         }
3355
3356         return 0;
3357 }
3358 EXPORT_SYMBOL_GPL(iscsi_set_param);
3359
3360 int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
3361                             enum iscsi_param param, char *buf)
3362 {
3363         struct iscsi_session *session = cls_session->dd_data;
3364         int len;
3365
3366         switch(param) {
3367         case ISCSI_PARAM_FAST_ABORT:
3368                 len = sprintf(buf, "%d\n", session->fast_abort);
3369                 break;
3370         case ISCSI_PARAM_ABORT_TMO:
3371                 len = sprintf(buf, "%d\n", session->abort_timeout);
3372                 break;
3373         case ISCSI_PARAM_LU_RESET_TMO:
3374                 len = sprintf(buf, "%d\n", session->lu_reset_timeout);
3375                 break;
3376         case ISCSI_PARAM_TGT_RESET_TMO:
3377                 len = sprintf(buf, "%d\n", session->tgt_reset_timeout);
3378                 break;
3379         case ISCSI_PARAM_INITIAL_R2T_EN:
3380                 len = sprintf(buf, "%d\n", session->initial_r2t_en);
3381                 break;
3382         case ISCSI_PARAM_MAX_R2T:
3383                 len = sprintf(buf, "%hu\n", session->max_r2t);
3384                 break;
3385         case ISCSI_PARAM_IMM_DATA_EN:
3386                 len = sprintf(buf, "%d\n", session->imm_data_en);
3387                 break;
3388         case ISCSI_PARAM_FIRST_BURST:
3389                 len = sprintf(buf, "%u\n", session->first_burst);
3390                 break;
3391         case ISCSI_PARAM_MAX_BURST:
3392                 len = sprintf(buf, "%u\n", session->max_burst);
3393                 break;
3394         case ISCSI_PARAM_PDU_INORDER_EN:
3395                 len = sprintf(buf, "%d\n", session->pdu_inorder_en);
3396                 break;
3397         case ISCSI_PARAM_DATASEQ_INORDER_EN:
3398                 len = sprintf(buf, "%d\n", session->dataseq_inorder_en);
3399                 break;
3400         case ISCSI_PARAM_DEF_TASKMGMT_TMO:
3401                 len = sprintf(buf, "%d\n", session->def_taskmgmt_tmo);
3402                 break;
3403         case ISCSI_PARAM_ERL:
3404                 len = sprintf(buf, "%d\n", session->erl);
3405                 break;
3406         case ISCSI_PARAM_TARGET_NAME:
3407                 len = sprintf(buf, "%s\n", session->targetname);
3408                 break;
3409         case ISCSI_PARAM_TARGET_ALIAS:
3410                 len = sprintf(buf, "%s\n", session->targetalias);
3411                 break;
3412         case ISCSI_PARAM_TPGT:
3413                 len = sprintf(buf, "%d\n", session->tpgt);
3414                 break;
3415         case ISCSI_PARAM_USERNAME:
3416                 len = sprintf(buf, "%s\n", session->username);
3417                 break;
3418         case ISCSI_PARAM_USERNAME_IN:
3419                 len = sprintf(buf, "%s\n", session->username_in);
3420                 break;
3421         case ISCSI_PARAM_PASSWORD:
3422                 len = sprintf(buf, "%s\n", session->password);
3423                 break;
3424         case ISCSI_PARAM_PASSWORD_IN:
3425                 len = sprintf(buf, "%s\n", session->password_in);
3426                 break;
3427         case ISCSI_PARAM_IFACE_NAME:
3428                 len = sprintf(buf, "%s\n", session->ifacename);
3429                 break;
3430         case ISCSI_PARAM_INITIATOR_NAME:
3431                 len = sprintf(buf, "%s\n", session->initiatorname);
3432                 break;
3433         case ISCSI_PARAM_BOOT_ROOT:
3434                 len = sprintf(buf, "%s\n", session->boot_root);
3435                 break;
3436         case ISCSI_PARAM_BOOT_NIC:
3437                 len = sprintf(buf, "%s\n", session->boot_nic);
3438                 break;
3439         case ISCSI_PARAM_BOOT_TARGET:
3440                 len = sprintf(buf, "%s\n", session->boot_target);
3441                 break;
3442         case ISCSI_PARAM_AUTO_SND_TGT_DISABLE:
3443                 len = sprintf(buf, "%u\n", session->auto_snd_tgt_disable);
3444                 break;
3445         case ISCSI_PARAM_DISCOVERY_SESS:
3446                 len = sprintf(buf, "%u\n", session->discovery_sess);
3447                 break;
3448         case ISCSI_PARAM_PORTAL_TYPE:
3449                 len = sprintf(buf, "%s\n", session->portal_type);
3450                 break;
3451         case ISCSI_PARAM_CHAP_AUTH_EN:
3452                 len = sprintf(buf, "%u\n", session->chap_auth_en);
3453                 break;
3454         case ISCSI_PARAM_DISCOVERY_LOGOUT_EN:
3455                 len = sprintf(buf, "%u\n", session->discovery_logout_en);
3456                 break;
3457         case ISCSI_PARAM_BIDI_CHAP_EN:
3458                 len = sprintf(buf, "%u\n", session->bidi_chap_en);
3459                 break;
3460         case ISCSI_PARAM_DISCOVERY_AUTH_OPTIONAL:
3461                 len = sprintf(buf, "%u\n", session->discovery_auth_optional);
3462                 break;
3463         case ISCSI_PARAM_DEF_TIME2WAIT:
3464                 len = sprintf(buf, "%d\n", session->time2wait);
3465                 break;
3466         case ISCSI_PARAM_DEF_TIME2RETAIN:
3467                 len = sprintf(buf, "%d\n", session->time2retain);
3468                 break;
3469         case ISCSI_PARAM_TSID:
3470                 len = sprintf(buf, "%u\n", session->tsid);
3471                 break;
3472         case ISCSI_PARAM_ISID:
3473                 len = sprintf(buf, "%02x%02x%02x%02x%02x%02x\n",
3474                               session->isid[0], session->isid[1],
3475                               session->isid[2], session->isid[3],
3476                               session->isid[4], session->isid[5]);
3477                 break;
3478         case ISCSI_PARAM_DISCOVERY_PARENT_IDX:
3479                 len = sprintf(buf, "%u\n", session->discovery_parent_idx);
3480                 break;
3481         case ISCSI_PARAM_DISCOVERY_PARENT_TYPE:
3482                 if (session->discovery_parent_type)
3483                         len = sprintf(buf, "%s\n",
3484                                       session->discovery_parent_type);
3485                 else
3486                         len = sprintf(buf, "\n");
3487                 break;
3488         default:
3489                 return -ENOSYS;
3490         }
3491
3492         return len;
3493 }
3494 EXPORT_SYMBOL_GPL(iscsi_session_get_param);
3495
3496 int iscsi_conn_get_addr_param(struct sockaddr_storage *addr,
3497                               enum iscsi_param param, char *buf)
3498 {
3499         struct sockaddr_in6 *sin6 = NULL;
3500         struct sockaddr_in *sin = NULL;
3501         int len;
3502
3503         switch (addr->ss_family) {
3504         case AF_INET:
3505                 sin = (struct sockaddr_in *)addr;
3506                 break;
3507         case AF_INET6:
3508                 sin6 = (struct sockaddr_in6 *)addr;
3509                 break;
3510         default:
3511                 return -EINVAL;
3512         }
3513
3514         switch (param) {
3515         case ISCSI_PARAM_CONN_ADDRESS:
3516         case ISCSI_HOST_PARAM_IPADDRESS:
3517                 if (sin)
3518                         len = sprintf(buf, "%pI4\n", &sin->sin_addr.s_addr);
3519                 else
3520                         len = sprintf(buf, "%pI6\n", &sin6->sin6_addr);
3521                 break;
3522         case ISCSI_PARAM_CONN_PORT:
3523         case ISCSI_PARAM_LOCAL_PORT:
3524                 if (sin)
3525                         len = sprintf(buf, "%hu\n", be16_to_cpu(sin->sin_port));
3526                 else
3527                         len = sprintf(buf, "%hu\n",
3528                                       be16_to_cpu(sin6->sin6_port));
3529                 break;
3530         default:
3531                 return -EINVAL;
3532         }
3533
3534         return len;
3535 }
3536 EXPORT_SYMBOL_GPL(iscsi_conn_get_addr_param);
3537
3538 int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
3539                          enum iscsi_param param, char *buf)
3540 {
3541         struct iscsi_conn *conn = cls_conn->dd_data;
3542         int len;
3543
3544         switch(param) {
3545         case ISCSI_PARAM_PING_TMO:
3546                 len = sprintf(buf, "%u\n", conn->ping_timeout);
3547                 break;
3548         case ISCSI_PARAM_RECV_TMO:
3549                 len = sprintf(buf, "%u\n", conn->recv_timeout);
3550                 break;
3551         case ISCSI_PARAM_MAX_RECV_DLENGTH:
3552                 len = sprintf(buf, "%u\n", conn->max_recv_dlength);
3553                 break;
3554         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3555                 len = sprintf(buf, "%u\n", conn->max_xmit_dlength);
3556                 break;
3557         case ISCSI_PARAM_HDRDGST_EN:
3558                 len = sprintf(buf, "%d\n", conn->hdrdgst_en);
3559                 break;
3560         case ISCSI_PARAM_DATADGST_EN:
3561                 len = sprintf(buf, "%d\n", conn->datadgst_en);
3562                 break;
3563         case ISCSI_PARAM_IFMARKER_EN:
3564                 len = sprintf(buf, "%d\n", conn->ifmarker_en);
3565                 break;
3566         case ISCSI_PARAM_OFMARKER_EN:
3567                 len = sprintf(buf, "%d\n", conn->ofmarker_en);
3568                 break;
3569         case ISCSI_PARAM_EXP_STATSN:
3570                 len = sprintf(buf, "%u\n", conn->exp_statsn);
3571                 break;
3572         case ISCSI_PARAM_PERSISTENT_PORT:
3573                 len = sprintf(buf, "%d\n", conn->persistent_port);
3574                 break;
3575         case ISCSI_PARAM_PERSISTENT_ADDRESS:
3576                 len = sprintf(buf, "%s\n", conn->persistent_address);
3577                 break;
3578         case ISCSI_PARAM_STATSN:
3579                 len = sprintf(buf, "%u\n", conn->statsn);
3580                 break;
3581         case ISCSI_PARAM_MAX_SEGMENT_SIZE:
3582                 len = sprintf(buf, "%u\n", conn->max_segment_size);
3583                 break;
3584         case ISCSI_PARAM_KEEPALIVE_TMO:
3585                 len = sprintf(buf, "%u\n", conn->keepalive_tmo);
3586                 break;
3587         case ISCSI_PARAM_LOCAL_PORT:
3588                 len = sprintf(buf, "%u\n", conn->local_port);
3589                 break;
3590         case ISCSI_PARAM_TCP_TIMESTAMP_STAT:
3591                 len = sprintf(buf, "%u\n", conn->tcp_timestamp_stat);
3592                 break;
3593         case ISCSI_PARAM_TCP_NAGLE_DISABLE:
3594                 len = sprintf(buf, "%u\n", conn->tcp_nagle_disable);
3595                 break;
3596         case ISCSI_PARAM_TCP_WSF_DISABLE:
3597                 len = sprintf(buf, "%u\n", conn->tcp_wsf_disable);
3598                 break;
3599         case ISCSI_PARAM_TCP_TIMER_SCALE:
3600                 len = sprintf(buf, "%u\n", conn->tcp_timer_scale);
3601                 break;
3602         case ISCSI_PARAM_TCP_TIMESTAMP_EN:
3603                 len = sprintf(buf, "%u\n", conn->tcp_timestamp_en);
3604                 break;
3605         case ISCSI_PARAM_IP_FRAGMENT_DISABLE:
3606                 len = sprintf(buf, "%u\n", conn->fragment_disable);
3607                 break;
3608         case ISCSI_PARAM_IPV4_TOS:
3609                 len = sprintf(buf, "%u\n", conn->ipv4_tos);
3610                 break;
3611         case ISCSI_PARAM_IPV6_TC:
3612                 len = sprintf(buf, "%u\n", conn->ipv6_traffic_class);
3613                 break;
3614         case ISCSI_PARAM_IPV6_FLOW_LABEL:
3615                 len = sprintf(buf, "%u\n", conn->ipv6_flow_label);
3616                 break;
3617         case ISCSI_PARAM_IS_FW_ASSIGNED_IPV6:
3618                 len = sprintf(buf, "%u\n", conn->is_fw_assigned_ipv6);
3619                 break;
3620         case ISCSI_PARAM_TCP_XMIT_WSF:
3621                 len = sprintf(buf, "%u\n", conn->tcp_xmit_wsf);
3622                 break;
3623         case ISCSI_PARAM_TCP_RECV_WSF:
3624                 len = sprintf(buf, "%u\n", conn->tcp_recv_wsf);
3625                 break;
3626         case ISCSI_PARAM_LOCAL_IPADDR:
3627                 len = sprintf(buf, "%s\n", conn->local_ipaddr);
3628                 break;
3629         default:
3630                 return -ENOSYS;
3631         }
3632
3633         return len;
3634 }
3635 EXPORT_SYMBOL_GPL(iscsi_conn_get_param);
3636
3637 int iscsi_host_get_param(struct Scsi_Host *shost, enum iscsi_host_param param,
3638                          char *buf)
3639 {
3640         struct iscsi_host *ihost = shost_priv(shost);
3641         int len;
3642
3643         switch (param) {
3644         case ISCSI_HOST_PARAM_NETDEV_NAME:
3645                 len = sprintf(buf, "%s\n", ihost->netdev);
3646                 break;
3647         case ISCSI_HOST_PARAM_HWADDRESS:
3648                 len = sprintf(buf, "%s\n", ihost->hwaddress);
3649                 break;
3650         case ISCSI_HOST_PARAM_INITIATOR_NAME:
3651                 len = sprintf(buf, "%s\n", ihost->initiatorname);
3652                 break;
3653         default:
3654                 return -ENOSYS;
3655         }
3656
3657         return len;
3658 }
3659 EXPORT_SYMBOL_GPL(iscsi_host_get_param);
3660
3661 int iscsi_host_set_param(struct Scsi_Host *shost, enum iscsi_host_param param,
3662                          char *buf, int buflen)
3663 {
3664         struct iscsi_host *ihost = shost_priv(shost);
3665
3666         switch (param) {
3667         case ISCSI_HOST_PARAM_NETDEV_NAME:
3668                 return iscsi_switch_str_param(&ihost->netdev, buf);
3669         case ISCSI_HOST_PARAM_HWADDRESS:
3670                 return iscsi_switch_str_param(&ihost->hwaddress, buf);
3671         case ISCSI_HOST_PARAM_INITIATOR_NAME:
3672                 return iscsi_switch_str_param(&ihost->initiatorname, buf);
3673         default:
3674                 return -ENOSYS;
3675         }
3676
3677         return 0;
3678 }
3679 EXPORT_SYMBOL_GPL(iscsi_host_set_param);
3680
3681 MODULE_AUTHOR("Mike Christie");
3682 MODULE_DESCRIPTION("iSCSI library functions");
3683 MODULE_LICENSE("GPL");