drivers/scsi/libiscsi.c

   1 /*
   2  * iSCSI lib functions
   3  *
   4  * Copyright (C) 2006 Red Hat, Inc.  All rights reserved.
   5  * Copyright (C) 2004 - 2006 Mike Christie
   6  * Copyright (C) 2004 - 2005 Dmitry Yusupov
   7  * Copyright (C) 2004 - 2005 Alex Aizman
   8  * maintained by open-iscsi@googlegroups.com
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  23  */
  24 #include <linux/types.h>
  25 #include <linux/kfifo.h>
  26 #include <linux/delay.h>
  27 #include <linux/log2.h>
  28 #include <linux/slab.h>
  29 #include <linux/sched/signal.h>
  30 #include <linux/module.h>
  31 #include <asm/unaligned.h>
  32 #include <net/tcp.h>
  33 #include <scsi/scsi_cmnd.h>
  34 #include <scsi/scsi_device.h>
  35 #include <scsi/scsi_eh.h>
  36 #include <scsi/scsi_tcq.h>
  37 #include <scsi/scsi_host.h>
  38 #include <scsi/scsi.h>
  39 #include <scsi/iscsi_proto.h>
  40 #include <scsi/scsi_transport.h>
  41 #include <scsi/scsi_transport_iscsi.h>
  42 #include <scsi/libiscsi.h>
  43
  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 itt "
 288                                           "0x%x/0x%x] "
 289                                           "rejected.\n",
 290                                           opcode, task->itt,
 291                                           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 itt "
 301                                           "0x%x/0x%x] fast abort.\n",
 302                                           opcode, task->itt,
 303                                           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                         /*
1700                          * cmds should fail during shutdown, if the session
1701                          * state is bad, allowing completion to happen
1702                          */
1703                         if (unlikely(system_state != SYSTEM_RUNNING)) {
1704                                 reason = FAILURE_SESSION_FAILED;
1705                                 sc->result = DID_NO_CONNECT << 16;
1706                                 break;
1707                         }
1708                         /* fall through */
1709                 case ISCSI_STATE_IN_RECOVERY:
1710                         reason = FAILURE_SESSION_IN_RECOVERY;
1711                         sc->result = DID_IMM_RETRY << 16;
1712                         break;
1713                 case ISCSI_STATE_LOGGING_OUT:
1714                         reason = FAILURE_SESSION_LOGGING_OUT;
1715                         sc->result = DID_IMM_RETRY << 16;
1716                         break;
1717                 case ISCSI_STATE_RECOVERY_FAILED:
1718                         reason = FAILURE_SESSION_RECOVERY_TIMEOUT;
1719                         sc->result = DID_TRANSPORT_FAILFAST << 16;
1720                         break;
1721                 case ISCSI_STATE_TERMINATE:
1722                         reason = FAILURE_SESSION_TERMINATE;
1723                         sc->result = DID_NO_CONNECT << 16;
1724                         break;
1725                 default:
1726                         reason = FAILURE_SESSION_FREED;
1727                         sc->result = DID_NO_CONNECT << 16;
1728                 }
1729                 goto fault;
1730         }
1731
1732         conn = session->leadconn;
1733         if (!conn) {
1734                 reason = FAILURE_SESSION_FREED;
1735                 sc->result = DID_NO_CONNECT << 16;
1736                 goto fault;
1737         }
1738
1739         if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx)) {
1740                 reason = FAILURE_SESSION_IN_RECOVERY;
1741                 sc->result = DID_REQUEUE << 16;
1742                 goto fault;
1743         }
1744
1745         if (iscsi_check_cmdsn_window_closed(conn)) {
1746                 reason = FAILURE_WINDOW_CLOSED;
1747                 goto reject;
1748         }
1749
1750         task = iscsi_alloc_task(conn, sc);
1751         if (!task) {
1752                 reason = FAILURE_OOM;
1753                 goto reject;
1754         }
1755
1756         if (!ihost->workq) {
1757                 reason = iscsi_prep_scsi_cmd_pdu(task);
1758                 if (reason) {
1759                         if (reason == -ENOMEM ||  reason == -EACCES) {
1760                                 reason = FAILURE_OOM;
1761                                 goto prepd_reject;
1762                         } else {
1763                                 sc->result = DID_ABORT << 16;
1764                                 goto prepd_fault;
1765                         }
1766                 }
1767                 if (session->tt->xmit_task(task)) {
1768                         session->cmdsn--;
1769                         reason = FAILURE_SESSION_NOT_READY;
1770                         goto prepd_reject;
1771                 }
1772         } else {
1773                 spin_lock_bh(&conn->taskqueuelock);
1774                 list_add_tail(&task->running, &conn->cmdqueue);
1775                 spin_unlock_bh(&conn->taskqueuelock);
1776                 iscsi_conn_queue_work(conn);
1777         }
1778
1779         session->queued_cmdsn++;
1780         spin_unlock_bh(&session->frwd_lock);
1781         return 0;
1782
1783 prepd_reject:
1784         iscsi_complete_task(task, ISCSI_TASK_REQUEUE_SCSIQ);
1785 reject:
1786         spin_unlock_bh(&session->frwd_lock);
1787         ISCSI_DBG_SESSION(session, "cmd 0x%x rejected (%d)\n",
1788                           sc->cmnd[0], reason);
1789         return SCSI_MLQUEUE_TARGET_BUSY;
1790
1791 prepd_fault:
1792         iscsi_complete_task(task, ISCSI_TASK_REQUEUE_SCSIQ);
1793 fault:
1794         spin_unlock_bh(&session->frwd_lock);
1795         ISCSI_DBG_SESSION(session, "iscsi: cmd 0x%x is not queued (%d)\n",
1796                           sc->cmnd[0], reason);
1797         if (!scsi_bidi_cmnd(sc))
1798                 scsi_set_resid(sc, scsi_bufflen(sc));
1799         else {
1800                 scsi_out(sc)->resid = scsi_out(sc)->length;
1801                 scsi_in(sc)->resid = scsi_in(sc)->length;
1802         }
1803         sc->scsi_done(sc);
1804         return 0;
1805 }
1806 EXPORT_SYMBOL_GPL(iscsi_queuecommand);
1807
1808 int iscsi_target_alloc(struct scsi_target *starget)
1809 {
1810         struct iscsi_cls_session *cls_session = starget_to_session(starget);
1811         struct iscsi_session *session = cls_session->dd_data;
1812
1813         starget->can_queue = session->scsi_cmds_max;
1814         return 0;
1815 }
1816 EXPORT_SYMBOL_GPL(iscsi_target_alloc);
1817
1818 static void iscsi_tmf_timedout(struct timer_list *t)
1819 {
1820         struct iscsi_conn *conn = from_timer(conn, t, tmf_timer);
1821         struct iscsi_session *session = conn->session;
1822
1823         spin_lock(&session->frwd_lock);
1824         if (conn->tmf_state == TMF_QUEUED) {
1825                 conn->tmf_state = TMF_TIMEDOUT;
1826                 ISCSI_DBG_EH(session, "tmf timedout\n");
1827                 /* unblock eh_abort() */
1828                 wake_up(&conn->ehwait);
1829         }
1830         spin_unlock(&session->frwd_lock);
1831 }
1832
1833 static int iscsi_exec_task_mgmt_fn(struct iscsi_conn *conn,
1834                                    struct iscsi_tm *hdr, int age,
1835                                    int timeout)
1836         __must_hold(&session->frwd_lock)
1837 {
1838         struct iscsi_session *session = conn->session;
1839         struct iscsi_task *task;
1840
1841         task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)hdr,
1842                                       NULL, 0);
1843         if (!task) {
1844                 spin_unlock_bh(&session->frwd_lock);
1845                 iscsi_conn_printk(KERN_ERR, conn, "Could not send TMF.\n");
1846                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1847                 spin_lock_bh(&session->frwd_lock);
1848                 return -EPERM;
1849         }
1850         conn->tmfcmd_pdus_cnt++;
1851         conn->tmf_timer.expires = timeout * HZ + jiffies;
1852         add_timer(&conn->tmf_timer);
1853         ISCSI_DBG_EH(session, "tmf set timeout\n");
1854
1855         spin_unlock_bh(&session->frwd_lock);
1856         mutex_unlock(&session->eh_mutex);
1857
1858         /*
1859          * block eh thread until:
1860          *
1861          * 1) tmf response
1862          * 2) tmf timeout
1863          * 3) session is terminated or restarted or userspace has
1864          * given up on recovery
1865          */
1866         wait_event_interruptible(conn->ehwait, age != session->age ||
1867                                  session->state != ISCSI_STATE_LOGGED_IN ||
1868                                  conn->tmf_state != TMF_QUEUED);
1869         if (signal_pending(current))
1870                 flush_signals(current);
1871         del_timer_sync(&conn->tmf_timer);
1872
1873         mutex_lock(&session->eh_mutex);
1874         spin_lock_bh(&session->frwd_lock);
1875         /* if the session drops it will clean up the task */
1876         if (age != session->age ||
1877             session->state != ISCSI_STATE_LOGGED_IN)
1878                 return -ENOTCONN;
1879         return 0;
1880 }
1881
1882 /*
1883  * Fail commands. session lock held and recv side suspended and xmit
1884  * thread flushed
1885  */
1886 static void fail_scsi_tasks(struct iscsi_conn *conn, u64 lun, int error)
1887 {
1888         struct iscsi_task *task;
1889         int i;
1890
1891         for (i = 0; i < conn->session->cmds_max; i++) {
1892                 task = conn->session->cmds[i];
1893                 if (!task->sc || task->state == ISCSI_TASK_FREE)
1894                         continue;
1895
1896                 if (lun != -1 && lun != task->sc->device->lun)
1897                         continue;
1898
1899                 ISCSI_DBG_SESSION(conn->session,
1900                                   "failing sc %p itt 0x%x state %d\n",
1901                                   task->sc, task->itt, task->state);
1902                 fail_scsi_task(task, error);
1903         }
1904 }
1905
1906 /**
1907  * iscsi_suspend_queue - suspend iscsi_queuecommand
1908  * @conn: iscsi conn to stop queueing IO on
1909  *
1910  * This grabs the session frwd_lock to make sure no one is in
1911  * xmit_task/queuecommand, and then sets suspend to prevent
1912  * new commands from being queued. This only needs to be called
1913  * by offload drivers that need to sync a path like ep disconnect
1914  * with the iscsi_queuecommand/xmit_task. To start IO again libiscsi
1915  * will call iscsi_start_tx and iscsi_unblock_session when in FFP.
1916  */
1917 void iscsi_suspend_queue(struct iscsi_conn *conn)
1918 {
1919         spin_lock_bh(&conn->session->frwd_lock);
1920         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1921         spin_unlock_bh(&conn->session->frwd_lock);
1922 }
1923 EXPORT_SYMBOL_GPL(iscsi_suspend_queue);
1924
1925 /**
1926  * iscsi_suspend_tx - suspend iscsi_data_xmit
1927  * @conn: iscsi conn tp stop processing IO on.
1928  *
1929  * This function sets the suspend bit to prevent iscsi_data_xmit
1930  * from sending new IO, and if work is queued on the xmit thread
1931  * it will wait for it to be completed.
1932  */
1933 void iscsi_suspend_tx(struct iscsi_conn *conn)
1934 {
1935         struct Scsi_Host *shost = conn->session->host;
1936         struct iscsi_host *ihost = shost_priv(shost);
1937
1938         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1939         if (ihost->workq)
1940                 flush_workqueue(ihost->workq);
1941 }
1942 EXPORT_SYMBOL_GPL(iscsi_suspend_tx);
1943
1944 static void iscsi_start_tx(struct iscsi_conn *conn)
1945 {
1946         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1947         iscsi_conn_queue_work(conn);
1948 }
1949
1950 /*
1951  * We want to make sure a ping is in flight. It has timed out.
1952  * And we are not busy processing a pdu that is making
1953  * progress but got started before the ping and is taking a while
1954  * to complete so the ping is just stuck behind it in a queue.
1955  */
1956 static int iscsi_has_ping_timed_out(struct iscsi_conn *conn)
1957 {
1958         if (conn->ping_task &&
1959             time_before_eq(conn->last_recv + (conn->recv_timeout * HZ) +
1960                            (conn->ping_timeout * HZ), jiffies))
1961                 return 1;
1962         else
1963                 return 0;
1964 }
1965
1966 enum blk_eh_timer_return iscsi_eh_cmd_timed_out(struct scsi_cmnd *sc)
1967 {
1968         enum blk_eh_timer_return rc = BLK_EH_DONE;
1969         struct iscsi_task *task = NULL, *running_task;
1970         struct iscsi_cls_session *cls_session;
1971         struct iscsi_session *session;
1972         struct iscsi_conn *conn;
1973         int i;
1974
1975         cls_session = starget_to_session(scsi_target(sc->device));
1976         session = cls_session->dd_data;
1977
1978         ISCSI_DBG_EH(session, "scsi cmd %p timedout\n", sc);
1979
1980         spin_lock(&session->frwd_lock);
1981         task = (struct iscsi_task *)sc->SCp.ptr;
1982         if (!task) {
1983                 /*
1984                  * Raced with completion. Blk layer has taken ownership
1985                  * so let timeout code complete it now.
1986                  */
1987                 rc = BLK_EH_DONE;
1988                 goto done;
1989         }
1990
1991         if (session->state != ISCSI_STATE_LOGGED_IN) {
1992                 /*
1993                  * During shutdown, if session is prematurely disconnected,
1994                  * recovery won't happen and there will be hung cmds. Not
1995                  * handling cmds would trigger EH, also bad in this case.
1996                  * Instead, handle cmd, allow completion to happen and let
1997                  * upper layer to deal with the result.
1998                  */
1999                 if (unlikely(system_state != SYSTEM_RUNNING)) {
2000                         sc->result = DID_NO_CONNECT << 16;
2001                         ISCSI_DBG_EH(session, "sc on shutdown, handled\n");
2002                         rc = BLK_EH_DONE;
2003                         goto done;
2004                 }
2005                 /*
2006                  * We are probably in the middle of iscsi recovery so let
2007                  * that complete and handle the error.
2008                  */
2009                 rc = BLK_EH_RESET_TIMER;
2010                 goto done;
2011         }
2012
2013         conn = session->leadconn;
2014         if (!conn) {
2015                 /* In the middle of shuting down */
2016                 rc = BLK_EH_RESET_TIMER;
2017                 goto done;
2018         }
2019
2020         /*
2021          * If we have sent (at least queued to the network layer) a pdu or
2022          * recvd one for the task since the last timeout ask for
2023          * more time. If on the next timeout we have not made progress
2024          * we can check if it is the task or connection when we send the
2025          * nop as a ping.
2026          */
2027         if (time_after(task->last_xfer, task->last_timeout)) {
2028                 ISCSI_DBG_EH(session, "Command making progress. Asking "
2029                              "scsi-ml for more time to complete. "
2030                              "Last data xfer at %lu. Last timeout was at "
2031                              "%lu\n.", task->last_xfer, task->last_timeout);
2032                 task->have_checked_conn = false;
2033                 rc = BLK_EH_RESET_TIMER;
2034                 goto done;
2035         }
2036
2037         if (!conn->recv_timeout && !conn->ping_timeout)
2038                 goto done;
2039         /*
2040          * if the ping timedout then we are in the middle of cleaning up
2041          * and can let the iscsi eh handle it
2042          */
2043         if (iscsi_has_ping_timed_out(conn)) {
2044                 rc = BLK_EH_RESET_TIMER;
2045                 goto done;
2046         }
2047
2048         for (i = 0; i < conn->session->cmds_max; i++) {
2049                 running_task = conn->session->cmds[i];
2050                 if (!running_task->sc || running_task == task ||
2051                      running_task->state != ISCSI_TASK_RUNNING)
2052                         continue;
2053
2054                 /*
2055                  * Only check if cmds started before this one have made
2056                  * progress, or this could never fail
2057                  */
2058                 if (time_after(running_task->sc->jiffies_at_alloc,
2059                                task->sc->jiffies_at_alloc))
2060                         continue;
2061
2062                 if (time_after(running_task->last_xfer, task->last_timeout)) {
2063                         /*
2064                          * This task has not made progress, but a task
2065                          * started before us has transferred data since
2066                          * we started/last-checked. We could be queueing
2067                          * too many tasks or the LU is bad.
2068                          *
2069                          * If the device is bad the cmds ahead of us on
2070                          * other devs will complete, and this loop will
2071                          * eventually fail starting the scsi eh.
2072                          */
2073                         ISCSI_DBG_EH(session, "Command has not made progress "
2074                                      "but commands ahead of it have. "
2075                                      "Asking scsi-ml for more time to "
2076                                      "complete. Our last xfer vs running task "
2077                                      "last xfer %lu/%lu. Last check %lu.\n",
2078                                      task->last_xfer, running_task->last_xfer,
2079                                      task->last_timeout);
2080                         rc = BLK_EH_RESET_TIMER;
2081                         goto done;
2082                 }
2083         }
2084
2085         /* Assumes nop timeout is shorter than scsi cmd timeout */
2086         if (task->have_checked_conn)
2087                 goto done;
2088
2089         /*
2090          * Checking the transport already or nop from a cmd timeout still
2091          * running
2092          */
2093         if (conn->ping_task) {
2094                 task->have_checked_conn = true;
2095                 rc = BLK_EH_RESET_TIMER;
2096                 goto done;
2097         }
2098
2099         /* Make sure there is a transport check done */
2100         iscsi_send_nopout(conn, NULL);
2101         task->have_checked_conn = true;
2102         rc = BLK_EH_RESET_TIMER;
2103
2104 done:
2105         if (task)
2106                 task->last_timeout = jiffies;
2107         spin_unlock(&session->frwd_lock);
2108         ISCSI_DBG_EH(session, "return %s\n", rc == BLK_EH_RESET_TIMER ?
2109                      "timer reset" : "shutdown or nh");
2110         return rc;
2111 }
2112 EXPORT_SYMBOL_GPL(iscsi_eh_cmd_timed_out);
2113
2114 static void iscsi_check_transport_timeouts(struct timer_list *t)
2115 {
2116         struct iscsi_conn *conn = from_timer(conn, t, transport_timer);
2117         struct iscsi_session *session = conn->session;
2118         unsigned long recv_timeout, next_timeout = 0, last_recv;
2119
2120         spin_lock(&session->frwd_lock);
2121         if (session->state != ISCSI_STATE_LOGGED_IN)
2122                 goto done;
2123
2124         recv_timeout = conn->recv_timeout;
2125         if (!recv_timeout)
2126                 goto done;
2127
2128         recv_timeout *= HZ;
2129         last_recv = conn->last_recv;
2130
2131         if (iscsi_has_ping_timed_out(conn)) {
2132                 iscsi_conn_printk(KERN_ERR, conn, "ping timeout of %d secs "
2133                                   "expired, recv timeout %d, last rx %lu, "
2134                                   "last ping %lu, now %lu\n",
2135                                   conn->ping_timeout, conn->recv_timeout,
2136                                   last_recv, conn->last_ping, jiffies);
2137                 spin_unlock(&session->frwd_lock);
2138                 iscsi_conn_failure(conn, ISCSI_ERR_NOP_TIMEDOUT);
2139                 return;
2140         }
2141
2142         if (time_before_eq(last_recv + recv_timeout, jiffies)) {
2143                 /* send a ping to try to provoke some traffic */
2144                 ISCSI_DBG_CONN(conn, "Sending nopout as ping\n");
2145                 if (iscsi_send_nopout(conn, NULL))
2146                         next_timeout = jiffies + (1 * HZ);
2147                 else
2148                         next_timeout = conn->last_ping + (conn->ping_timeout * HZ);
2149         } else
2150                 next_timeout = last_recv + recv_timeout;
2151
2152         ISCSI_DBG_CONN(conn, "Setting next tmo %lu\n", next_timeout);
2153         mod_timer(&conn->transport_timer, next_timeout);
2154 done:
2155         spin_unlock(&session->frwd_lock);
2156 }
2157
2158 static void iscsi_prep_abort_task_pdu(struct iscsi_task *task,
2159                                       struct iscsi_tm *hdr)
2160 {
2161         memset(hdr, 0, sizeof(*hdr));
2162         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2163         hdr->flags = ISCSI_TM_FUNC_ABORT_TASK & ISCSI_FLAG_TM_FUNC_MASK;
2164         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2165         hdr->lun = task->lun;
2166         hdr->rtt = task->hdr_itt;
2167         hdr->refcmdsn = task->cmdsn;
2168 }
2169
2170 int iscsi_eh_abort(struct scsi_cmnd *sc)
2171 {
2172         struct iscsi_cls_session *cls_session;
2173         struct iscsi_session *session;
2174         struct iscsi_conn *conn;
2175         struct iscsi_task *task;
2176         struct iscsi_tm *hdr;
2177         int age;
2178
2179         cls_session = starget_to_session(scsi_target(sc->device));
2180         session = cls_session->dd_data;
2181
2182         ISCSI_DBG_EH(session, "aborting sc %p\n", sc);
2183
2184         mutex_lock(&session->eh_mutex);
2185         spin_lock_bh(&session->frwd_lock);
2186         /*
2187          * if session was ISCSI_STATE_IN_RECOVERY then we may not have
2188          * got the command.
2189          */
2190         if (!sc->SCp.ptr) {
2191                 ISCSI_DBG_EH(session, "sc never reached iscsi layer or "
2192                                       "it completed.\n");
2193                 spin_unlock_bh(&session->frwd_lock);
2194                 mutex_unlock(&session->eh_mutex);
2195                 return SUCCESS;
2196         }
2197
2198         /*
2199          * If we are not logged in or we have started a new session
2200          * then let the host reset code handle this
2201          */
2202         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN ||
2203             sc->SCp.phase != session->age) {
2204                 spin_unlock_bh(&session->frwd_lock);
2205                 mutex_unlock(&session->eh_mutex);
2206                 ISCSI_DBG_EH(session, "failing abort due to dropped "
2207                                   "session.\n");
2208                 return FAILED;
2209         }
2210
2211         conn = session->leadconn;
2212         conn->eh_abort_cnt++;
2213         age = session->age;
2214
2215         task = (struct iscsi_task *)sc->SCp.ptr;
2216         ISCSI_DBG_EH(session, "aborting [sc %p itt 0x%x]\n",
2217                      sc, task->itt);
2218
2219         /* task completed before time out */
2220         if (!task->sc) {
2221                 ISCSI_DBG_EH(session, "sc completed while abort in progress\n");
2222                 goto success;
2223         }
2224
2225         if (task->state == ISCSI_TASK_PENDING) {
2226                 fail_scsi_task(task, DID_ABORT);
2227                 goto success;
2228         }
2229
2230         /* only have one tmf outstanding at a time */
2231         if (conn->tmf_state != TMF_INITIAL)
2232                 goto failed;
2233         conn->tmf_state = TMF_QUEUED;
2234
2235         hdr = &conn->tmhdr;
2236         iscsi_prep_abort_task_pdu(task, hdr);
2237
2238         if (iscsi_exec_task_mgmt_fn(conn, hdr, age, session->abort_timeout))
2239                 goto failed;
2240
2241         switch (conn->tmf_state) {
2242         case TMF_SUCCESS:
2243                 spin_unlock_bh(&session->frwd_lock);
2244                 /*
2245                  * stop tx side incase the target had sent a abort rsp but
2246                  * the initiator was still writing out data.
2247                  */
2248                 iscsi_suspend_tx(conn);
2249                 /*
2250                  * we do not stop the recv side because targets have been
2251                  * good and have never sent us a successful tmf response
2252                  * then sent more data for the cmd.
2253                  */
2254                 spin_lock_bh(&session->frwd_lock);
2255                 fail_scsi_task(task, DID_ABORT);
2256                 conn->tmf_state = TMF_INITIAL;
2257                 memset(hdr, 0, sizeof(*hdr));
2258                 spin_unlock_bh(&session->frwd_lock);
2259                 iscsi_start_tx(conn);
2260                 goto success_unlocked;
2261         case TMF_TIMEDOUT:
2262                 spin_unlock_bh(&session->frwd_lock);
2263                 iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2264                 goto failed_unlocked;
2265         case TMF_NOT_FOUND:
2266                 if (!sc->SCp.ptr) {
2267                         conn->tmf_state = TMF_INITIAL;
2268                         memset(hdr, 0, sizeof(*hdr));
2269                         /* task completed before tmf abort response */
2270                         ISCSI_DBG_EH(session, "sc completed while abort in "
2271                                               "progress\n");
2272                         goto success;
2273                 }
2274                 /* fall through */
2275         default:
2276                 conn->tmf_state = TMF_INITIAL;
2277                 goto failed;
2278         }
2279
2280 success:
2281         spin_unlock_bh(&session->frwd_lock);
2282 success_unlocked:
2283         ISCSI_DBG_EH(session, "abort success [sc %p itt 0x%x]\n",
2284                      sc, task->itt);
2285         mutex_unlock(&session->eh_mutex);
2286         return SUCCESS;
2287
2288 failed:
2289         spin_unlock_bh(&session->frwd_lock);
2290 failed_unlocked:
2291         ISCSI_DBG_EH(session, "abort failed [sc %p itt 0x%x]\n", sc,
2292                      task ? task->itt : 0);
2293         mutex_unlock(&session->eh_mutex);
2294         return FAILED;
2295 }
2296 EXPORT_SYMBOL_GPL(iscsi_eh_abort);
2297
2298 static void iscsi_prep_lun_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
2299 {
2300         memset(hdr, 0, sizeof(*hdr));
2301         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2302         hdr->flags = ISCSI_TM_FUNC_LOGICAL_UNIT_RESET & ISCSI_FLAG_TM_FUNC_MASK;
2303         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2304         int_to_scsilun(sc->device->lun, &hdr->lun);
2305         hdr->rtt = RESERVED_ITT;
2306 }
2307
2308 int iscsi_eh_device_reset(struct scsi_cmnd *sc)
2309 {
2310         struct iscsi_cls_session *cls_session;
2311         struct iscsi_session *session;
2312         struct iscsi_conn *conn;
2313         struct iscsi_tm *hdr;
2314         int rc = FAILED;
2315
2316         cls_session = starget_to_session(scsi_target(sc->device));
2317         session = cls_session->dd_data;
2318
2319         ISCSI_DBG_EH(session, "LU Reset [sc %p lun %llu]\n", sc,
2320                      sc->device->lun);
2321
2322         mutex_lock(&session->eh_mutex);
2323         spin_lock_bh(&session->frwd_lock);
2324         /*
2325          * Just check if we are not logged in. We cannot check for
2326          * the phase because the reset could come from a ioctl.
2327          */
2328         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
2329                 goto unlock;
2330         conn = session->leadconn;
2331
2332         /* only have one tmf outstanding at a time */
2333         if (conn->tmf_state != TMF_INITIAL)
2334                 goto unlock;
2335         conn->tmf_state = TMF_QUEUED;
2336
2337         hdr = &conn->tmhdr;
2338         iscsi_prep_lun_reset_pdu(sc, hdr);
2339
2340         if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
2341                                     session->lu_reset_timeout)) {
2342                 rc = FAILED;
2343                 goto unlock;
2344         }
2345
2346         switch (conn->tmf_state) {
2347         case TMF_SUCCESS:
2348                 break;
2349         case TMF_TIMEDOUT:
2350                 spin_unlock_bh(&session->frwd_lock);
2351                 iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2352                 goto done;
2353         default:
2354                 conn->tmf_state = TMF_INITIAL;
2355                 goto unlock;
2356         }
2357
2358         rc = SUCCESS;
2359         spin_unlock_bh(&session->frwd_lock);
2360
2361         iscsi_suspend_tx(conn);
2362
2363         spin_lock_bh(&session->frwd_lock);
2364         memset(hdr, 0, sizeof(*hdr));
2365         fail_scsi_tasks(conn, sc->device->lun, DID_ERROR);
2366         conn->tmf_state = TMF_INITIAL;
2367         spin_unlock_bh(&session->frwd_lock);
2368
2369         iscsi_start_tx(conn);
2370         goto done;
2371
2372 unlock:
2373         spin_unlock_bh(&session->frwd_lock);
2374 done:
2375         ISCSI_DBG_EH(session, "dev reset result = %s\n",
2376                      rc == SUCCESS ? "SUCCESS" : "FAILED");
2377         mutex_unlock(&session->eh_mutex);
2378         return rc;
2379 }
2380 EXPORT_SYMBOL_GPL(iscsi_eh_device_reset);
2381
2382 void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
2383 {
2384         struct iscsi_session *session = cls_session->dd_data;
2385
2386         spin_lock_bh(&session->frwd_lock);
2387         if (session->state != ISCSI_STATE_LOGGED_IN) {
2388                 session->state = ISCSI_STATE_RECOVERY_FAILED;
2389                 if (session->leadconn)
2390                         wake_up(&session->leadconn->ehwait);
2391         }
2392         spin_unlock_bh(&session->frwd_lock);
2393 }
2394 EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
2395
2396 /**
2397  * iscsi_eh_session_reset - drop session and attempt relogin
2398  * @sc: scsi command
2399  *
2400  * This function will wait for a relogin, session termination from
2401  * userspace, or a recovery/replacement timeout.
2402  */
2403 int iscsi_eh_session_reset(struct scsi_cmnd *sc)
2404 {
2405         struct iscsi_cls_session *cls_session;
2406         struct iscsi_session *session;
2407         struct iscsi_conn *conn;
2408
2409         cls_session = starget_to_session(scsi_target(sc->device));
2410         session = cls_session->dd_data;
2411         conn = session->leadconn;
2412
2413         mutex_lock(&session->eh_mutex);
2414         spin_lock_bh(&session->frwd_lock);
2415         if (session->state == ISCSI_STATE_TERMINATE) {
2416 failed:
2417                 ISCSI_DBG_EH(session,
2418                              "failing session reset: Could not log back into "
2419                              "%s, %s [age %d]\n", session->targetname,
2420                              conn->persistent_address, session->age);
2421                 spin_unlock_bh(&session->frwd_lock);
2422                 mutex_unlock(&session->eh_mutex);
2423                 return FAILED;
2424         }
2425
2426         spin_unlock_bh(&session->frwd_lock);
2427         mutex_unlock(&session->eh_mutex);
2428         /*
2429          * we drop the lock here but the leadconn cannot be destoyed while
2430          * we are in the scsi eh
2431          */
2432         iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2433
2434         ISCSI_DBG_EH(session, "wait for relogin\n");
2435         wait_event_interruptible(conn->ehwait,
2436                                  session->state == ISCSI_STATE_TERMINATE ||
2437                                  session->state == ISCSI_STATE_LOGGED_IN ||
2438                                  session->state == ISCSI_STATE_RECOVERY_FAILED);
2439         if (signal_pending(current))
2440                 flush_signals(current);
2441
2442         mutex_lock(&session->eh_mutex);
2443         spin_lock_bh(&session->frwd_lock);
2444         if (session->state == ISCSI_STATE_LOGGED_IN) {
2445                 ISCSI_DBG_EH(session,
2446                              "session reset succeeded for %s,%s\n",
2447                              session->targetname, conn->persistent_address);
2448         } else
2449                 goto failed;
2450         spin_unlock_bh(&session->frwd_lock);
2451         mutex_unlock(&session->eh_mutex);
2452         return SUCCESS;
2453 }
2454 EXPORT_SYMBOL_GPL(iscsi_eh_session_reset);
2455
2456 static void iscsi_prep_tgt_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
2457 {
2458         memset(hdr, 0, sizeof(*hdr));
2459         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2460         hdr->flags = ISCSI_TM_FUNC_TARGET_WARM_RESET & ISCSI_FLAG_TM_FUNC_MASK;
2461         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2462         hdr->rtt = RESERVED_ITT;
2463 }
2464
2465 /**
2466  * iscsi_eh_target_reset - reset target
2467  * @sc: scsi command
2468  *
2469  * This will attempt to send a warm target reset.
2470  */
2471 static int iscsi_eh_target_reset(struct scsi_cmnd *sc)
2472 {
2473         struct iscsi_cls_session *cls_session;
2474         struct iscsi_session *session;
2475         struct iscsi_conn *conn;
2476         struct iscsi_tm *hdr;
2477         int rc = FAILED;
2478
2479         cls_session = starget_to_session(scsi_target(sc->device));
2480         session = cls_session->dd_data;
2481
2482         ISCSI_DBG_EH(session, "tgt Reset [sc %p tgt %s]\n", sc,
2483                      session->targetname);
2484
2485         mutex_lock(&session->eh_mutex);
2486         spin_lock_bh(&session->frwd_lock);
2487         /*
2488          * Just check if we are not logged in. We cannot check for
2489          * the phase because the reset could come from a ioctl.
2490          */
2491         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
2492                 goto unlock;
2493         conn = session->leadconn;
2494
2495         /* only have one tmf outstanding at a time */
2496         if (conn->tmf_state != TMF_INITIAL)
2497                 goto unlock;
2498         conn->tmf_state = TMF_QUEUED;
2499
2500         hdr = &conn->tmhdr;
2501         iscsi_prep_tgt_reset_pdu(sc, hdr);
2502
2503         if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
2504                                     session->tgt_reset_timeout)) {
2505                 rc = FAILED;
2506                 goto unlock;
2507         }
2508
2509         switch (conn->tmf_state) {
2510         case TMF_SUCCESS:
2511                 break;
2512         case TMF_TIMEDOUT:
2513                 spin_unlock_bh(&session->frwd_lock);
2514                 iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2515                 goto done;
2516         default:
2517                 conn->tmf_state = TMF_INITIAL;
2518                 goto unlock;
2519         }
2520
2521         rc = SUCCESS;
2522         spin_unlock_bh(&session->frwd_lock);
2523
2524         iscsi_suspend_tx(conn);
2525
2526         spin_lock_bh(&session->frwd_lock);
2527         memset(hdr, 0, sizeof(*hdr));
2528         fail_scsi_tasks(conn, -1, DID_ERROR);
2529         conn->tmf_state = TMF_INITIAL;
2530         spin_unlock_bh(&session->frwd_lock);
2531
2532         iscsi_start_tx(conn);
2533         goto done;
2534
2535 unlock:
2536         spin_unlock_bh(&session->frwd_lock);
2537 done:
2538         ISCSI_DBG_EH(session, "tgt %s reset result = %s\n", session->targetname,
2539                      rc == SUCCESS ? "SUCCESS" : "FAILED");
2540         mutex_unlock(&session->eh_mutex);
2541         return rc;
2542 }
2543
2544 /**
2545  * iscsi_eh_recover_target - reset target and possibly the session
2546  * @sc: scsi command
2547  *
2548  * This will attempt to send a warm target reset. If that fails,
2549  * we will escalate to ERL0 session recovery.
2550  */
2551 int iscsi_eh_recover_target(struct scsi_cmnd *sc)
2552 {
2553         int rc;
2554
2555         rc = iscsi_eh_target_reset(sc);
2556         if (rc == FAILED)
2557                 rc = iscsi_eh_session_reset(sc);
2558         return rc;
2559 }
2560 EXPORT_SYMBOL_GPL(iscsi_eh_recover_target);
2561
2562 /*
2563  * Pre-allocate a pool of @max items of @item_size. By default, the pool
2564  * should be accessed via kfifo_{get,put} on q->queue.
2565  * Optionally, the caller can obtain the array of object pointers
2566  * by passing in a non-NULL @items pointer
2567  */
2568 int
2569 iscsi_pool_init(struct iscsi_pool *q, int max, void ***items, int item_size)
2570 {
2571         int i, num_arrays = 1;
2572
2573         memset(q, 0, sizeof(*q));
2574
2575         q->max = max;
2576
2577         /* If the user passed an items pointer, he wants a copy of
2578          * the array. */
2579         if (items)
2580                 num_arrays++;
2581         q->pool = kvcalloc(num_arrays * max, sizeof(void *), GFP_KERNEL);
2582         if (q->pool == NULL)
2583                 return -ENOMEM;
2584
2585         kfifo_init(&q->queue, (void*)q->pool, max * sizeof(void*));
2586
2587         for (i = 0; i < max; i++) {
2588                 q->pool[i] = kzalloc(item_size, GFP_KERNEL);
2589                 if (q->pool[i] == NULL) {
2590                         q->max = i;
2591                         goto enomem;
2592                 }
2593                 kfifo_in(&q->queue, (void*)&q->pool[i], sizeof(void*));
2594         }
2595
2596         if (items) {
2597                 *items = q->pool + max;
2598                 memcpy(*items, q->pool, max * sizeof(void *));
2599         }
2600
2601         return 0;
2602
2603 enomem:
2604         iscsi_pool_free(q);
2605         return -ENOMEM;
2606 }
2607 EXPORT_SYMBOL_GPL(iscsi_pool_init);
2608
2609 void iscsi_pool_free(struct iscsi_pool *q)
2610 {
2611         int i;
2612
2613         for (i = 0; i < q->max; i++)
2614                 kfree(q->pool[i]);
2615         kvfree(q->pool);
2616 }
2617 EXPORT_SYMBOL_GPL(iscsi_pool_free);
2618
2619 /**
2620  * iscsi_host_add - add host to system
2621  * @shost: scsi host
2622  * @pdev: parent device
2623  *
2624  * This should be called by partial offload and software iscsi drivers
2625  * to add a host to the system.
2626  */
2627 int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev)
2628 {
2629         if (!shost->can_queue)
2630                 shost->can_queue = ISCSI_DEF_XMIT_CMDS_MAX;
2631
2632         if (!shost->cmd_per_lun)
2633                 shost->cmd_per_lun = ISCSI_DEF_CMD_PER_LUN;
2634
2635         return scsi_add_host(shost, pdev);
2636 }
2637 EXPORT_SYMBOL_GPL(iscsi_host_add);
2638
2639 /**
2640  * iscsi_host_alloc - allocate a host and driver data
2641  * @sht: scsi host template
2642  * @dd_data_size: driver host data size
2643  * @xmit_can_sleep: bool indicating if LLD will queue IO from a work queue
2644  *
2645  * This should be called by partial offload and software iscsi drivers.
2646  * To access the driver specific memory use the iscsi_host_priv() macro.
2647  */
2648 struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
2649                                    int dd_data_size, bool xmit_can_sleep)
2650 {
2651         struct Scsi_Host *shost;
2652         struct iscsi_host *ihost;
2653
2654         shost = scsi_host_alloc(sht, sizeof(struct iscsi_host) + dd_data_size);
2655         if (!shost)
2656                 return NULL;
2657         ihost = shost_priv(shost);
2658
2659         if (xmit_can_sleep) {
2660                 snprintf(ihost->workq_name, sizeof(ihost->workq_name),
2661                         "iscsi_q_%d", shost->host_no);
2662                 ihost->workq = create_singlethread_workqueue(ihost->workq_name);
2663                 if (!ihost->workq)
2664                         goto free_host;
2665         }
2666
2667         spin_lock_init(&ihost->lock);
2668         ihost->state = ISCSI_HOST_SETUP;
2669         ihost->num_sessions = 0;
2670         init_waitqueue_head(&ihost->session_removal_wq);
2671         return shost;
2672
2673 free_host:
2674         scsi_host_put(shost);
2675         return NULL;
2676 }
2677 EXPORT_SYMBOL_GPL(iscsi_host_alloc);
2678
2679 static void iscsi_notify_host_removed(struct iscsi_cls_session *cls_session)
2680 {
2681         iscsi_session_failure(cls_session->dd_data, ISCSI_ERR_INVALID_HOST);
2682 }
2683
2684 /**
2685  * iscsi_host_remove - remove host and sessions
2686  * @shost: scsi host
2687  *
2688  * If there are any sessions left, this will initiate the removal and wait
2689  * for the completion.
2690  */
2691 void iscsi_host_remove(struct Scsi_Host *shost)
2692 {
2693         struct iscsi_host *ihost = shost_priv(shost);
2694         unsigned long flags;
2695
2696         spin_lock_irqsave(&ihost->lock, flags);
2697         ihost->state = ISCSI_HOST_REMOVED;
2698         spin_unlock_irqrestore(&ihost->lock, flags);
2699
2700         iscsi_host_for_each_session(shost, iscsi_notify_host_removed);
2701         wait_event_interruptible(ihost->session_removal_wq,
2702                                  ihost->num_sessions == 0);
2703         if (signal_pending(current))
2704                 flush_signals(current);
2705
2706         scsi_remove_host(shost);
2707         if (ihost->workq)
2708                 destroy_workqueue(ihost->workq);
2709 }
2710 EXPORT_SYMBOL_GPL(iscsi_host_remove);
2711
2712 void iscsi_host_free(struct Scsi_Host *shost)
2713 {
2714         struct iscsi_host *ihost = shost_priv(shost);
2715
2716         kfree(ihost->netdev);
2717         kfree(ihost->hwaddress);
2718         kfree(ihost->initiatorname);
2719         scsi_host_put(shost);
2720 }
2721 EXPORT_SYMBOL_GPL(iscsi_host_free);
2722
2723 static void iscsi_host_dec_session_cnt(struct Scsi_Host *shost)
2724 {
2725         struct iscsi_host *ihost = shost_priv(shost);
2726         unsigned long flags;
2727
2728         shost = scsi_host_get(shost);
2729         if (!shost) {
2730                 printk(KERN_ERR "Invalid state. Cannot notify host removal "
2731                       "of session teardown event because host already "
2732                       "removed.\n");
2733                 return;
2734         }
2735
2736         spin_lock_irqsave(&ihost->lock, flags);
2737         ihost->num_sessions--;
2738         if (ihost->num_sessions == 0)
2739                 wake_up(&ihost->session_removal_wq);
2740         spin_unlock_irqrestore(&ihost->lock, flags);
2741         scsi_host_put(shost);
2742 }
2743
2744 /**
2745  * iscsi_session_setup - create iscsi cls session and host and session
2746  * @iscsit: iscsi transport template
2747  * @shost: scsi host
2748  * @cmds_max: session can queue
2749  * @dd_size: private driver data size, added to session allocation size
2750  * @cmd_task_size: LLD task private data size
2751  * @initial_cmdsn: initial CmdSN
2752  * @id: target ID to add to this session
2753  *
2754  * This can be used by software iscsi_transports that allocate
2755  * a session per scsi host.
2756  *
2757  * Callers should set cmds_max to the largest total numer (mgmt + scsi) of
2758  * tasks they support. The iscsi layer reserves ISCSI_MGMT_CMDS_MAX tasks
2759  * for nop handling and login/logout requests.
2760  */
2761 struct iscsi_cls_session *
2762 iscsi_session_setup(struct iscsi_transport *iscsit, struct Scsi_Host *shost,
2763                     uint16_t cmds_max, int dd_size, int cmd_task_size,
2764                     uint32_t initial_cmdsn, unsigned int id)
2765 {
2766         struct iscsi_host *ihost = shost_priv(shost);
2767         struct iscsi_session *session;
2768         struct iscsi_cls_session *cls_session;
2769         int cmd_i, scsi_cmds, total_cmds = cmds_max;
2770         unsigned long flags;
2771
2772         spin_lock_irqsave(&ihost->lock, flags);
2773         if (ihost->state == ISCSI_HOST_REMOVED) {
2774                 spin_unlock_irqrestore(&ihost->lock, flags);
2775                 return NULL;
2776         }
2777         ihost->num_sessions++;
2778         spin_unlock_irqrestore(&ihost->lock, flags);
2779
2780         if (!total_cmds)
2781                 total_cmds = ISCSI_DEF_XMIT_CMDS_MAX;
2782         /*
2783          * The iscsi layer needs some tasks for nop handling and tmfs,
2784          * so the cmds_max must at least be greater than ISCSI_MGMT_CMDS_MAX
2785          * + 1 command for scsi IO.
2786          */
2787         if (total_cmds < ISCSI_TOTAL_CMDS_MIN) {
2788                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2789                        "must be a power of two that is at least %d.\n",
2790                        total_cmds, ISCSI_TOTAL_CMDS_MIN);
2791                 goto dec_session_count;
2792         }
2793
2794         if (total_cmds > ISCSI_TOTAL_CMDS_MAX) {
2795                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2796                        "must be a power of 2 less than or equal to %d.\n",
2797                        cmds_max, ISCSI_TOTAL_CMDS_MAX);
2798                 total_cmds = ISCSI_TOTAL_CMDS_MAX;
2799         }
2800
2801         if (!is_power_of_2(total_cmds)) {
2802                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2803                        "must be a power of 2.\n", total_cmds);
2804                 total_cmds = rounddown_pow_of_two(total_cmds);
2805                 if (total_cmds < ISCSI_TOTAL_CMDS_MIN)
2806                         return NULL;
2807                 printk(KERN_INFO "iscsi: Rounding can_queue to %d.\n",
2808                        total_cmds);
2809         }
2810         scsi_cmds = total_cmds - ISCSI_MGMT_CMDS_MAX;
2811
2812         cls_session = iscsi_alloc_session(shost, iscsit,
2813                                           sizeof(struct iscsi_session) +
2814                                           dd_size);
2815         if (!cls_session)
2816                 goto dec_session_count;
2817         session = cls_session->dd_data;
2818         session->cls_session = cls_session;
2819         session->host = shost;
2820         session->state = ISCSI_STATE_FREE;
2821         session->fast_abort = 1;
2822         session->tgt_reset_timeout = 30;
2823         session->lu_reset_timeout = 15;
2824         session->abort_timeout = 10;
2825         session->scsi_cmds_max = scsi_cmds;
2826         session->cmds_max = total_cmds;
2827         session->queued_cmdsn = session->cmdsn = initial_cmdsn;
2828         session->exp_cmdsn = initial_cmdsn + 1;
2829         session->max_cmdsn = initial_cmdsn + 1;
2830         session->max_r2t = 1;
2831         session->tt = iscsit;
2832         session->dd_data = cls_session->dd_data + sizeof(*session);
2833
2834         mutex_init(&session->eh_mutex);
2835         spin_lock_init(&session->frwd_lock);
2836         spin_lock_init(&session->back_lock);
2837
2838         /* initialize SCSI PDU commands pool */
2839         if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
2840                             (void***)&session->cmds,
2841                             cmd_task_size + sizeof(struct iscsi_task)))
2842                 goto cmdpool_alloc_fail;
2843
2844         /* pre-format cmds pool with ITT */
2845         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
2846                 struct iscsi_task *task = session->cmds[cmd_i];
2847
2848                 if (cmd_task_size)
2849                         task->dd_data = &task[1];
2850                 task->itt = cmd_i;
2851                 task->state = ISCSI_TASK_FREE;
2852                 INIT_LIST_HEAD(&task->running);
2853         }
2854
2855         if (!try_module_get(iscsit->owner))
2856                 goto module_get_fail;
2857
2858         if (iscsi_add_session(cls_session, id))
2859                 goto cls_session_fail;
2860
2861         return cls_session;
2862
2863 cls_session_fail:
2864         module_put(iscsit->owner);
2865 module_get_fail:
2866         iscsi_pool_free(&session->cmdpool);
2867 cmdpool_alloc_fail:
2868         iscsi_free_session(cls_session);
2869 dec_session_count:
2870         iscsi_host_dec_session_cnt(shost);
2871         return NULL;
2872 }
2873 EXPORT_SYMBOL_GPL(iscsi_session_setup);
2874
2875 /**
2876  * iscsi_session_teardown - destroy session, host, and cls_session
2877  * @cls_session: iscsi session
2878  */
2879 void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
2880 {
2881         struct iscsi_session *session = cls_session->dd_data;
2882         struct module *owner = cls_session->transport->owner;
2883         struct Scsi_Host *shost = session->host;
2884
2885         iscsi_pool_free(&session->cmdpool);
2886
2887         iscsi_remove_session(cls_session);
2888
2889         kfree(session->password);
2890         kfree(session->password_in);
2891         kfree(session->username);
2892         kfree(session->username_in);
2893         kfree(session->targetname);
2894         kfree(session->targetalias);
2895         kfree(session->initiatorname);
2896         kfree(session->boot_root);
2897         kfree(session->boot_nic);
2898         kfree(session->boot_target);
2899         kfree(session->ifacename);
2900         kfree(session->portal_type);
2901         kfree(session->discovery_parent_type);
2902
2903         iscsi_free_session(cls_session);
2904
2905         iscsi_host_dec_session_cnt(shost);
2906         module_put(owner);
2907 }
2908 EXPORT_SYMBOL_GPL(iscsi_session_teardown);
2909
2910 /**
2911  * iscsi_conn_setup - create iscsi_cls_conn and iscsi_conn
2912  * @cls_session: iscsi_cls_session
2913  * @dd_size: private driver data size
2914  * @conn_idx: cid
2915  */
2916 struct iscsi_cls_conn *
2917 iscsi_conn_setup(struct iscsi_cls_session *cls_session, int dd_size,
2918                  uint32_t conn_idx)
2919 {
2920         struct iscsi_session *session = cls_session->dd_data;
2921         struct iscsi_conn *conn;
2922         struct iscsi_cls_conn *cls_conn;
2923         char *data;
2924
2925         cls_conn = iscsi_create_conn(cls_session, sizeof(*conn) + dd_size,
2926                                      conn_idx);
2927         if (!cls_conn)
2928                 return NULL;
2929         conn = cls_conn->dd_data;
2930         memset(conn, 0, sizeof(*conn) + dd_size);
2931
2932         conn->dd_data = cls_conn->dd_data + sizeof(*conn);
2933         conn->session = session;
2934         conn->cls_conn = cls_conn;
2935         conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
2936         conn->id = conn_idx;
2937         conn->exp_statsn = 0;
2938         conn->tmf_state = TMF_INITIAL;
2939
2940         timer_setup(&conn->transport_timer, iscsi_check_transport_timeouts, 0);
2941
2942         INIT_LIST_HEAD(&conn->mgmtqueue);
2943         INIT_LIST_HEAD(&conn->cmdqueue);
2944         INIT_LIST_HEAD(&conn->requeue);
2945         spin_lock_init(&conn->taskqueuelock);
2946         INIT_WORK(&conn->xmitwork, iscsi_xmitworker);
2947
2948         /* allocate login_task used for the login/text sequences */
2949         spin_lock_bh(&session->frwd_lock);
2950         if (!kfifo_out(&session->cmdpool.queue,
2951                          (void*)&conn->login_task,
2952                          sizeof(void*))) {
2953                 spin_unlock_bh(&session->frwd_lock);
2954                 goto login_task_alloc_fail;
2955         }
2956         spin_unlock_bh(&session->frwd_lock);
2957
2958         data = (char *) __get_free_pages(GFP_KERNEL,
2959                                          get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
2960         if (!data)
2961                 goto login_task_data_alloc_fail;
2962         conn->login_task->data = conn->data = data;
2963
2964         timer_setup(&conn->tmf_timer, iscsi_tmf_timedout, 0);
2965         init_waitqueue_head(&conn->ehwait);
2966
2967         return cls_conn;
2968
2969 login_task_data_alloc_fail:
2970         kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
2971                     sizeof(void*));
2972 login_task_alloc_fail:
2973         iscsi_destroy_conn(cls_conn);
2974         return NULL;
2975 }
2976 EXPORT_SYMBOL_GPL(iscsi_conn_setup);
2977
2978 /**
2979  * iscsi_conn_teardown - teardown iscsi connection
2980  * @cls_conn: iscsi class connection
2981  *
2982  * TODO: we may need to make this into a two step process
2983  * like scsi-mls remove + put host
2984  */
2985 void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
2986 {
2987         struct iscsi_conn *conn = cls_conn->dd_data;
2988         struct iscsi_session *session = conn->session;
2989
2990         del_timer_sync(&conn->transport_timer);
2991
2992         mutex_lock(&session->eh_mutex);
2993         spin_lock_bh(&session->frwd_lock);
2994         conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
2995         if (session->leadconn == conn) {
2996                 /*
2997                  * leading connection? then give up on recovery.
2998                  */
2999                 session->state = ISCSI_STATE_TERMINATE;
3000                 wake_up(&conn->ehwait);
3001         }
3002         spin_unlock_bh(&session->frwd_lock);
3003
3004         /* flush queued up work because we free the connection below */
3005         iscsi_suspend_tx(conn);
3006
3007         spin_lock_bh(&session->frwd_lock);
3008         free_pages((unsigned long) conn->data,
3009                    get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
3010         kfree(conn->persistent_address);
3011         kfree(conn->local_ipaddr);
3012         /* regular RX path uses back_lock */
3013         spin_lock_bh(&session->back_lock);
3014         kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
3015                     sizeof(void*));
3016         spin_unlock_bh(&session->back_lock);
3017         if (session->leadconn == conn)
3018                 session->leadconn = NULL;
3019         spin_unlock_bh(&session->frwd_lock);
3020         mutex_unlock(&session->eh_mutex);
3021
3022         iscsi_destroy_conn(cls_conn);
3023 }
3024 EXPORT_SYMBOL_GPL(iscsi_conn_teardown);
3025
3026 int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
3027 {
3028         struct iscsi_conn *conn = cls_conn->dd_data;
3029         struct iscsi_session *session = conn->session;
3030
3031         if (!session) {
3032                 iscsi_conn_printk(KERN_ERR, conn,
3033                                   "can't start unbound connection\n");
3034                 return -EPERM;
3035         }
3036
3037         if ((session->imm_data_en || !session->initial_r2t_en) &&
3038              session->first_burst > session->max_burst) {
3039                 iscsi_conn_printk(KERN_INFO, conn, "invalid burst lengths: "
3040                                   "first_burst %d max_burst %d\n",
3041                                   session->first_burst, session->max_burst);
3042                 return -EINVAL;
3043         }
3044
3045         if (conn->ping_timeout && !conn->recv_timeout) {
3046                 iscsi_conn_printk(KERN_ERR, conn, "invalid recv timeout of "
3047                                   "zero. Using 5 seconds\n.");
3048                 conn->recv_timeout = 5;
3049         }
3050
3051         if (conn->recv_timeout && !conn->ping_timeout) {
3052                 iscsi_conn_printk(KERN_ERR, conn, "invalid ping timeout of "
3053                                   "zero. Using 5 seconds.\n");
3054                 conn->ping_timeout = 5;
3055         }
3056
3057         spin_lock_bh(&session->frwd_lock);
3058         conn->c_stage = ISCSI_CONN_STARTED;
3059         session->state = ISCSI_STATE_LOGGED_IN;
3060         session->queued_cmdsn = session->cmdsn;
3061
3062         conn->last_recv = jiffies;
3063         conn->last_ping = jiffies;
3064         if (conn->recv_timeout && conn->ping_timeout)
3065                 mod_timer(&conn->transport_timer,
3066                           jiffies + (conn->recv_timeout * HZ));
3067
3068         switch(conn->stop_stage) {
3069         case STOP_CONN_RECOVER:
3070                 /*
3071                  * unblock eh_abort() if it is blocked. re-try all
3072                  * commands after successful recovery
3073                  */
3074                 conn->stop_stage = 0;
3075                 conn->tmf_state = TMF_INITIAL;
3076                 session->age++;
3077                 if (session->age == 16)
3078                         session->age = 0;
3079                 break;
3080         case STOP_CONN_TERM:
3081                 conn->stop_stage = 0;
3082                 break;
3083         default:
3084                 break;
3085         }
3086         spin_unlock_bh(&session->frwd_lock);
3087
3088         iscsi_unblock_session(session->cls_session);
3089         wake_up(&conn->ehwait);
3090         return 0;
3091 }
3092 EXPORT_SYMBOL_GPL(iscsi_conn_start);
3093
3094 static void
3095 fail_mgmt_tasks(struct iscsi_session *session, struct iscsi_conn *conn)
3096 {
3097         struct iscsi_task *task;
3098         int i, state;
3099
3100         for (i = 0; i < conn->session->cmds_max; i++) {
3101                 task = conn->session->cmds[i];
3102                 if (task->sc)
3103                         continue;
3104
3105                 if (task->state == ISCSI_TASK_FREE)
3106                         continue;
3107
3108                 ISCSI_DBG_SESSION(conn->session,
3109                                   "failing mgmt itt 0x%x state %d\n",
3110                                   task->itt, task->state);
3111                 state = ISCSI_TASK_ABRT_SESS_RECOV;
3112                 if (task->state == ISCSI_TASK_PENDING)
3113                         state = ISCSI_TASK_COMPLETED;
3114                 iscsi_complete_task(task, state);
3115
3116         }
3117 }
3118
3119 static void iscsi_start_session_recovery(struct iscsi_session *session,
3120                                          struct iscsi_conn *conn, int flag)
3121 {
3122         int old_stop_stage;
3123
3124         mutex_lock(&session->eh_mutex);
3125         spin_lock_bh(&session->frwd_lock);
3126         if (conn->stop_stage == STOP_CONN_TERM) {
3127                 spin_unlock_bh(&session->frwd_lock);
3128                 mutex_unlock(&session->eh_mutex);
3129                 return;
3130         }
3131
3132         /*
3133          * When this is called for the in_login state, we only want to clean
3134          * up the login task and connection. We do not need to block and set
3135          * the recovery state again
3136          */
3137         if (flag == STOP_CONN_TERM)
3138                 session->state = ISCSI_STATE_TERMINATE;
3139         else if (conn->stop_stage != STOP_CONN_RECOVER)
3140                 session->state = ISCSI_STATE_IN_RECOVERY;
3141
3142         old_stop_stage = conn->stop_stage;
3143         conn->stop_stage = flag;
3144         spin_unlock_bh(&session->frwd_lock);
3145
3146         del_timer_sync(&conn->transport_timer);
3147         iscsi_suspend_tx(conn);
3148
3149         spin_lock_bh(&session->frwd_lock);
3150         conn->c_stage = ISCSI_CONN_STOPPED;
3151         spin_unlock_bh(&session->frwd_lock);
3152
3153         /*
3154          * for connection level recovery we should not calculate
3155          * header digest. conn->hdr_size used for optimization
3156          * in hdr_extract() and will be re-negotiated at
3157          * set_param() time.
3158          */
3159         if (flag == STOP_CONN_RECOVER) {
3160                 conn->hdrdgst_en = 0;
3161                 conn->datadgst_en = 0;
3162                 if (session->state == ISCSI_STATE_IN_RECOVERY &&
3163                     old_stop_stage != STOP_CONN_RECOVER) {
3164                         ISCSI_DBG_SESSION(session, "blocking session\n");
3165                         iscsi_block_session(session->cls_session);
3166                 }
3167         }
3168
3169         /*
3170          * flush queues.
3171          */
3172         spin_lock_bh(&session->frwd_lock);
3173         fail_scsi_tasks(conn, -1, DID_TRANSPORT_DISRUPTED);
3174         fail_mgmt_tasks(session, conn);
3175         memset(&conn->tmhdr, 0, sizeof(conn->tmhdr));
3176         spin_unlock_bh(&session->frwd_lock);
3177         mutex_unlock(&session->eh_mutex);
3178 }
3179
3180 void iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
3181 {
3182         struct iscsi_conn *conn = cls_conn->dd_data;
3183         struct iscsi_session *session = conn->session;
3184
3185         switch (flag) {
3186         case STOP_CONN_RECOVER:
3187         case STOP_CONN_TERM:
3188                 iscsi_start_session_recovery(session, conn, flag);
3189                 break;
3190         default:
3191                 iscsi_conn_printk(KERN_ERR, conn,
3192                                   "invalid stop flag %d\n", flag);
3193         }
3194 }
3195 EXPORT_SYMBOL_GPL(iscsi_conn_stop);
3196
3197 int iscsi_conn_bind(struct iscsi_cls_session *cls_session,
3198                     struct iscsi_cls_conn *cls_conn, int is_leading)
3199 {
3200         struct iscsi_session *session = cls_session->dd_data;
3201         struct iscsi_conn *conn = cls_conn->dd_data;
3202
3203         spin_lock_bh(&session->frwd_lock);
3204         if (is_leading)
3205                 session->leadconn = conn;
3206         spin_unlock_bh(&session->frwd_lock);
3207
3208         /*
3209          * Unblock xmitworker(), Login Phase will pass through.
3210          */
3211         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
3212         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
3213         return 0;
3214 }
3215 EXPORT_SYMBOL_GPL(iscsi_conn_bind);
3216
3217 int iscsi_switch_str_param(char **param, char *new_val_buf)
3218 {
3219         char *new_val;
3220
3221         if (*param) {
3222                 if (!strcmp(*param, new_val_buf))
3223                         return 0;
3224         }
3225
3226         new_val = kstrdup(new_val_buf, GFP_NOIO);
3227         if (!new_val)
3228                 return -ENOMEM;
3229
3230         kfree(*param);
3231         *param = new_val;
3232         return 0;
3233 }
3234 EXPORT_SYMBOL_GPL(iscsi_switch_str_param);
3235
3236 int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
3237                     enum iscsi_param param, char *buf, int buflen)
3238 {
3239         struct iscsi_conn *conn = cls_conn->dd_data;
3240         struct iscsi_session *session = conn->session;
3241         int val;
3242
3243         switch(param) {
3244         case ISCSI_PARAM_FAST_ABORT:
3245                 sscanf(buf, "%d", &session->fast_abort);
3246                 break;
3247         case ISCSI_PARAM_ABORT_TMO:
3248                 sscanf(buf, "%d", &session->abort_timeout);
3249                 break;
3250         case ISCSI_PARAM_LU_RESET_TMO:
3251                 sscanf(buf, "%d", &session->lu_reset_timeout);
3252                 break;
3253         case ISCSI_PARAM_TGT_RESET_TMO:
3254                 sscanf(buf, "%d", &session->tgt_reset_timeout);
3255                 break;
3256         case ISCSI_PARAM_PING_TMO:
3257                 sscanf(buf, "%d", &conn->ping_timeout);
3258                 break;
3259         case ISCSI_PARAM_RECV_TMO:
3260                 sscanf(buf, "%d", &conn->recv_timeout);
3261                 break;
3262         case ISCSI_PARAM_MAX_RECV_DLENGTH:
3263                 sscanf(buf, "%d", &conn->max_recv_dlength);
3264                 break;
3265         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3266                 sscanf(buf, "%d", &conn->max_xmit_dlength);
3267                 break;
3268         case ISCSI_PARAM_HDRDGST_EN:
3269                 sscanf(buf, "%d", &conn->hdrdgst_en);
3270                 break;
3271         case ISCSI_PARAM_DATADGST_EN:
3272                 sscanf(buf, "%d", &conn->datadgst_en);
3273                 break;
3274         case ISCSI_PARAM_INITIAL_R2T_EN:
3275                 sscanf(buf, "%d", &session->initial_r2t_en);
3276                 break;
3277         case ISCSI_PARAM_MAX_R2T:
3278                 sscanf(buf, "%hu", &session->max_r2t);
3279                 break;
3280         case ISCSI_PARAM_IMM_DATA_EN:
3281                 sscanf(buf, "%d", &session->imm_data_en);
3282                 break;
3283         case ISCSI_PARAM_FIRST_BURST:
3284                 sscanf(buf, "%d", &session->first_burst);
3285                 break;
3286         case ISCSI_PARAM_MAX_BURST:
3287                 sscanf(buf, "%d", &session->max_burst);
3288                 break;
3289         case ISCSI_PARAM_PDU_INORDER_EN:
3290                 sscanf(buf, "%d", &session->pdu_inorder_en);
3291                 break;
3292         case ISCSI_PARAM_DATASEQ_INORDER_EN:
3293                 sscanf(buf, "%d", &session->dataseq_inorder_en);
3294                 break;
3295         case ISCSI_PARAM_ERL:
3296                 sscanf(buf, "%d", &session->erl);
3297                 break;
3298         case ISCSI_PARAM_EXP_STATSN:
3299                 sscanf(buf, "%u", &conn->exp_statsn);
3300                 break;
3301         case ISCSI_PARAM_USERNAME:
3302                 return iscsi_switch_str_param(&session->username, buf);
3303         case ISCSI_PARAM_USERNAME_IN:
3304                 return iscsi_switch_str_param(&session->username_in, buf);
3305         case ISCSI_PARAM_PASSWORD:
3306                 return iscsi_switch_str_param(&session->password, buf);
3307         case ISCSI_PARAM_PASSWORD_IN:
3308                 return iscsi_switch_str_param(&session->password_in, buf);
3309         case ISCSI_PARAM_TARGET_NAME:
3310                 return iscsi_switch_str_param(&session->targetname, buf);
3311         case ISCSI_PARAM_TARGET_ALIAS:
3312                 return iscsi_switch_str_param(&session->targetalias, buf);
3313         case ISCSI_PARAM_TPGT:
3314                 sscanf(buf, "%d", &session->tpgt);
3315                 break;
3316         case ISCSI_PARAM_PERSISTENT_PORT:
3317                 sscanf(buf, "%d", &conn->persistent_port);
3318                 break;
3319         case ISCSI_PARAM_PERSISTENT_ADDRESS:
3320                 return iscsi_switch_str_param(&conn->persistent_address, buf);
3321         case ISCSI_PARAM_IFACE_NAME:
3322                 return iscsi_switch_str_param(&session->ifacename, buf);
3323         case ISCSI_PARAM_INITIATOR_NAME:
3324                 return iscsi_switch_str_param(&session->initiatorname, buf);
3325         case ISCSI_PARAM_BOOT_ROOT:
3326                 return iscsi_switch_str_param(&session->boot_root, buf);
3327         case ISCSI_PARAM_BOOT_NIC:
3328                 return iscsi_switch_str_param(&session->boot_nic, buf);
3329         case ISCSI_PARAM_BOOT_TARGET:
3330                 return iscsi_switch_str_param(&session->boot_target, buf);
3331         case ISCSI_PARAM_PORTAL_TYPE:
3332                 return iscsi_switch_str_param(&session->portal_type, buf);
3333         case ISCSI_PARAM_DISCOVERY_PARENT_TYPE:
3334                 return iscsi_switch_str_param(&session->discovery_parent_type,
3335                                               buf);
3336         case ISCSI_PARAM_DISCOVERY_SESS:
3337                 sscanf(buf, "%d", &val);
3338                 session->discovery_sess = !!val;
3339                 break;
3340         case ISCSI_PARAM_LOCAL_IPADDR:
3341                 return iscsi_switch_str_param(&conn->local_ipaddr, buf);
3342         default:
3343                 return -ENOSYS;
3344         }
3345
3346         return 0;
3347 }
3348 EXPORT_SYMBOL_GPL(iscsi_set_param);
3349
3350 int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
3351                             enum iscsi_param param, char *buf)
3352 {
3353         struct iscsi_session *session = cls_session->dd_data;
3354         int len;
3355
3356         switch(param) {
3357         case ISCSI_PARAM_FAST_ABORT:
3358                 len = sprintf(buf, "%d\n", session->fast_abort);
3359                 break;
3360         case ISCSI_PARAM_ABORT_TMO:
3361                 len = sprintf(buf, "%d\n", session->abort_timeout);
3362                 break;
3363         case ISCSI_PARAM_LU_RESET_TMO:
3364                 len = sprintf(buf, "%d\n", session->lu_reset_timeout);
3365                 break;
3366         case ISCSI_PARAM_TGT_RESET_TMO:
3367                 len = sprintf(buf, "%d\n", session->tgt_reset_timeout);
3368                 break;
3369         case ISCSI_PARAM_INITIAL_R2T_EN:
3370                 len = sprintf(buf, "%d\n", session->initial_r2t_en);
3371                 break;
3372         case ISCSI_PARAM_MAX_R2T:
3373                 len = sprintf(buf, "%hu\n", session->max_r2t);
3374                 break;
3375         case ISCSI_PARAM_IMM_DATA_EN:
3376                 len = sprintf(buf, "%d\n", session->imm_data_en);
3377                 break;
3378         case ISCSI_PARAM_FIRST_BURST:
3379                 len = sprintf(buf, "%u\n", session->first_burst);
3380                 break;
3381         case ISCSI_PARAM_MAX_BURST:
3382                 len = sprintf(buf, "%u\n", session->max_burst);
3383                 break;
3384         case ISCSI_PARAM_PDU_INORDER_EN:
3385                 len = sprintf(buf, "%d\n", session->pdu_inorder_en);
3386                 break;
3387         case ISCSI_PARAM_DATASEQ_INORDER_EN:
3388                 len = sprintf(buf, "%d\n", session->dataseq_inorder_en);
3389                 break;
3390         case ISCSI_PARAM_DEF_TASKMGMT_TMO:
3391                 len = sprintf(buf, "%d\n", session->def_taskmgmt_tmo);
3392                 break;
3393         case ISCSI_PARAM_ERL:
3394                 len = sprintf(buf, "%d\n", session->erl);
3395                 break;
3396         case ISCSI_PARAM_TARGET_NAME:
3397                 len = sprintf(buf, "%s\n", session->targetname);
3398                 break;
3399         case ISCSI_PARAM_TARGET_ALIAS:
3400                 len = sprintf(buf, "%s\n", session->targetalias);
3401                 break;
3402         case ISCSI_PARAM_TPGT:
3403                 len = sprintf(buf, "%d\n", session->tpgt);
3404                 break;
3405         case ISCSI_PARAM_USERNAME:
3406                 len = sprintf(buf, "%s\n", session->username);
3407                 break;
3408         case ISCSI_PARAM_USERNAME_IN:
3409                 len = sprintf(buf, "%s\n", session->username_in);
3410                 break;
3411         case ISCSI_PARAM_PASSWORD:
3412                 len = sprintf(buf, "%s\n", session->password);
3413                 break;
3414         case ISCSI_PARAM_PASSWORD_IN:
3415                 len = sprintf(buf, "%s\n", session->password_in);
3416                 break;
3417         case ISCSI_PARAM_IFACE_NAME:
3418                 len = sprintf(buf, "%s\n", session->ifacename);
3419                 break;
3420         case ISCSI_PARAM_INITIATOR_NAME:
3421                 len = sprintf(buf, "%s\n", session->initiatorname);
3422                 break;
3423         case ISCSI_PARAM_BOOT_ROOT:
3424                 len = sprintf(buf, "%s\n", session->boot_root);
3425                 break;
3426         case ISCSI_PARAM_BOOT_NIC:
3427                 len = sprintf(buf, "%s\n", session->boot_nic);
3428                 break;
3429         case ISCSI_PARAM_BOOT_TARGET:
3430                 len = sprintf(buf, "%s\n", session->boot_target);
3431                 break;
3432         case ISCSI_PARAM_AUTO_SND_TGT_DISABLE:
3433                 len = sprintf(buf, "%u\n", session->auto_snd_tgt_disable);
3434                 break;
3435         case ISCSI_PARAM_DISCOVERY_SESS:
3436                 len = sprintf(buf, "%u\n", session->discovery_sess);
3437                 break;
3438         case ISCSI_PARAM_PORTAL_TYPE:
3439                 len = sprintf(buf, "%s\n", session->portal_type);
3440                 break;
3441         case ISCSI_PARAM_CHAP_AUTH_EN:
3442                 len = sprintf(buf, "%u\n", session->chap_auth_en);
3443                 break;
3444         case ISCSI_PARAM_DISCOVERY_LOGOUT_EN:
3445                 len = sprintf(buf, "%u\n", session->discovery_logout_en);
3446                 break;
3447         case ISCSI_PARAM_BIDI_CHAP_EN:
3448                 len = sprintf(buf, "%u\n", session->bidi_chap_en);
3449                 break;
3450         case ISCSI_PARAM_DISCOVERY_AUTH_OPTIONAL:
3451                 len = sprintf(buf, "%u\n", session->discovery_auth_optional);
3452                 break;
3453         case ISCSI_PARAM_DEF_TIME2WAIT:
3454                 len = sprintf(buf, "%d\n", session->time2wait);
3455                 break;
3456         case ISCSI_PARAM_DEF_TIME2RETAIN:
3457                 len = sprintf(buf, "%d\n", session->time2retain);
3458                 break;
3459         case ISCSI_PARAM_TSID:
3460                 len = sprintf(buf, "%u\n", session->tsid);
3461                 break;
3462         case ISCSI_PARAM_ISID:
3463                 len = sprintf(buf, "%02x%02x%02x%02x%02x%02x\n",
3464                               session->isid[0], session->isid[1],
3465                               session->isid[2], session->isid[3],
3466                               session->isid[4], session->isid[5]);
3467                 break;
3468         case ISCSI_PARAM_DISCOVERY_PARENT_IDX:
3469                 len = sprintf(buf, "%u\n", session->discovery_parent_idx);
3470                 break;
3471         case ISCSI_PARAM_DISCOVERY_PARENT_TYPE:
3472                 if (session->discovery_parent_type)
3473                         len = sprintf(buf, "%s\n",
3474                                       session->discovery_parent_type);
3475                 else
3476                         len = sprintf(buf, "\n");
3477                 break;
3478         default:
3479                 return -ENOSYS;
3480         }
3481
3482         return len;
3483 }
3484 EXPORT_SYMBOL_GPL(iscsi_session_get_param);
3485
3486 int iscsi_conn_get_addr_param(struct sockaddr_storage *addr,
3487                               enum iscsi_param param, char *buf)
3488 {
3489         struct sockaddr_in6 *sin6 = NULL;
3490         struct sockaddr_in *sin = NULL;
3491         int len;
3492
3493         switch (addr->ss_family) {
3494         case AF_INET:
3495                 sin = (struct sockaddr_in *)addr;
3496                 break;
3497         case AF_INET6:
3498                 sin6 = (struct sockaddr_in6 *)addr;
3499                 break;
3500         default:
3501                 return -EINVAL;
3502         }
3503
3504         switch (param) {
3505         case ISCSI_PARAM_CONN_ADDRESS:
3506         case ISCSI_HOST_PARAM_IPADDRESS:
3507                 if (sin)
3508                         len = sprintf(buf, "%pI4\n", &sin->sin_addr.s_addr);
3509                 else
3510                         len = sprintf(buf, "%pI6\n", &sin6->sin6_addr);
3511                 break;
3512         case ISCSI_PARAM_CONN_PORT:
3513         case ISCSI_PARAM_LOCAL_PORT:
3514                 if (sin)
3515                         len = sprintf(buf, "%hu\n", be16_to_cpu(sin->sin_port));
3516                 else
3517                         len = sprintf(buf, "%hu\n",
3518                                       be16_to_cpu(sin6->sin6_port));
3519                 break;
3520         default:
3521                 return -EINVAL;
3522         }
3523
3524         return len;
3525 }
3526 EXPORT_SYMBOL_GPL(iscsi_conn_get_addr_param);
3527
3528 int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
3529                          enum iscsi_param param, char *buf)
3530 {
3531         struct iscsi_conn *conn = cls_conn->dd_data;
3532         int len;
3533
3534         switch(param) {
3535         case ISCSI_PARAM_PING_TMO:
3536                 len = sprintf(buf, "%u\n", conn->ping_timeout);
3537                 break;
3538         case ISCSI_PARAM_RECV_TMO:
3539                 len = sprintf(buf, "%u\n", conn->recv_timeout);
3540                 break;
3541         case ISCSI_PARAM_MAX_RECV_DLENGTH:
3542                 len = sprintf(buf, "%u\n", conn->max_recv_dlength);
3543                 break;
3544         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3545                 len = sprintf(buf, "%u\n", conn->max_xmit_dlength);
3546                 break;
3547         case ISCSI_PARAM_HDRDGST_EN:
3548                 len = sprintf(buf, "%d\n", conn->hdrdgst_en);
3549                 break;
3550         case ISCSI_PARAM_DATADGST_EN:
3551                 len = sprintf(buf, "%d\n", conn->datadgst_en);
3552                 break;
3553         case ISCSI_PARAM_IFMARKER_EN:
3554                 len = sprintf(buf, "%d\n", conn->ifmarker_en);
3555                 break;
3556         case ISCSI_PARAM_OFMARKER_EN:
3557                 len = sprintf(buf, "%d\n", conn->ofmarker_en);
3558                 break;
3559         case ISCSI_PARAM_EXP_STATSN:
3560                 len = sprintf(buf, "%u\n", conn->exp_statsn);
3561                 break;
3562         case ISCSI_PARAM_PERSISTENT_PORT:
3563                 len = sprintf(buf, "%d\n", conn->persistent_port);
3564                 break;
3565         case ISCSI_PARAM_PERSISTENT_ADDRESS:
3566                 len = sprintf(buf, "%s\n", conn->persistent_address);
3567                 break;
3568         case ISCSI_PARAM_STATSN:
3569                 len = sprintf(buf, "%u\n", conn->statsn);
3570                 break;
3571         case ISCSI_PARAM_MAX_SEGMENT_SIZE:
3572                 len = sprintf(buf, "%u\n", conn->max_segment_size);
3573                 break;
3574         case ISCSI_PARAM_KEEPALIVE_TMO:
3575                 len = sprintf(buf, "%u\n", conn->keepalive_tmo);
3576                 break;
3577         case ISCSI_PARAM_LOCAL_PORT:
3578                 len = sprintf(buf, "%u\n", conn->local_port);
3579                 break;
3580         case ISCSI_PARAM_TCP_TIMESTAMP_STAT:
3581                 len = sprintf(buf, "%u\n", conn->tcp_timestamp_stat);
3582                 break;
3583         case ISCSI_PARAM_TCP_NAGLE_DISABLE:
3584                 len = sprintf(buf, "%u\n", conn->tcp_nagle_disable);
3585                 break;
3586         case ISCSI_PARAM_TCP_WSF_DISABLE:
3587                 len = sprintf(buf, "%u\n", conn->tcp_wsf_disable);
3588                 break;
3589         case ISCSI_PARAM_TCP_TIMER_SCALE:
3590                 len = sprintf(buf, "%u\n", conn->tcp_timer_scale);
3591                 break;
3592         case ISCSI_PARAM_TCP_TIMESTAMP_EN:
3593                 len = sprintf(buf, "%u\n", conn->tcp_timestamp_en);
3594                 break;
3595         case ISCSI_PARAM_IP_FRAGMENT_DISABLE:
3596                 len = sprintf(buf, "%u\n", conn->fragment_disable);
3597                 break;
3598         case ISCSI_PARAM_IPV4_TOS:
3599                 len = sprintf(buf, "%u\n", conn->ipv4_tos);
3600                 break;
3601         case ISCSI_PARAM_IPV6_TC:
3602                 len = sprintf(buf, "%u\n", conn->ipv6_traffic_class);
3603                 break;
3604         case ISCSI_PARAM_IPV6_FLOW_LABEL:
3605                 len = sprintf(buf, "%u\n", conn->ipv6_flow_label);
3606                 break;
3607         case ISCSI_PARAM_IS_FW_ASSIGNED_IPV6:
3608                 len = sprintf(buf, "%u\n", conn->is_fw_assigned_ipv6);
3609                 break;
3610         case ISCSI_PARAM_TCP_XMIT_WSF:
3611                 len = sprintf(buf, "%u\n", conn->tcp_xmit_wsf);
3612                 break;
3613         case ISCSI_PARAM_TCP_RECV_WSF:
3614                 len = sprintf(buf, "%u\n", conn->tcp_recv_wsf);
3615                 break;
3616         case ISCSI_PARAM_LOCAL_IPADDR:
3617                 len = sprintf(buf, "%s\n", conn->local_ipaddr);
3618                 break;
3619         default:
3620                 return -ENOSYS;
3621         }
3622
3623         return len;
3624 }
3625 EXPORT_SYMBOL_GPL(iscsi_conn_get_param);
3626
3627 int iscsi_host_get_param(struct Scsi_Host *shost, enum iscsi_host_param param,
3628                          char *buf)
3629 {
3630         struct iscsi_host *ihost = shost_priv(shost);
3631         int len;
3632
3633         switch (param) {
3634         case ISCSI_HOST_PARAM_NETDEV_NAME:
3635                 len = sprintf(buf, "%s\n", ihost->netdev);
3636                 break;
3637         case ISCSI_HOST_PARAM_HWADDRESS:
3638                 len = sprintf(buf, "%s\n", ihost->hwaddress);
3639                 break;
3640         case ISCSI_HOST_PARAM_INITIATOR_NAME:
3641                 len = sprintf(buf, "%s\n", ihost->initiatorname);
3642                 break;
3643         default:
3644                 return -ENOSYS;
3645         }
3646
3647         return len;
3648 }
3649 EXPORT_SYMBOL_GPL(iscsi_host_get_param);
3650
3651 int iscsi_host_set_param(struct Scsi_Host *shost, enum iscsi_host_param param,
3652                          char *buf, int buflen)
3653 {
3654         struct iscsi_host *ihost = shost_priv(shost);
3655
3656         switch (param) {
3657         case ISCSI_HOST_PARAM_NETDEV_NAME:
3658                 return iscsi_switch_str_param(&ihost->netdev, buf);
3659         case ISCSI_HOST_PARAM_HWADDRESS:
3660                 return iscsi_switch_str_param(&ihost->hwaddress, buf);
3661         case ISCSI_HOST_PARAM_INITIATOR_NAME:
3662                 return iscsi_switch_str_param(&ihost->initiatorname, buf);
3663         default:
3664                 return -ENOSYS;
3665         }
3666
3667         return 0;
3668 }
3669 EXPORT_SYMBOL_GPL(iscsi_host_set_param);
3670
3671 MODULE_AUTHOR("Mike Christie");
3672 MODULE_DESCRIPTION("iSCSI library functions");
3673 MODULE_LICENSE("GPL");