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