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