drivers/scsi/libiscsi.c

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