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