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/module.h>
  30 #include <asm/unaligned.h>
  31 #include <net/tcp.h>
  32 #include <scsi/scsi_cmnd.h>
  33 #include <scsi/scsi_device.h>
  34 #include <scsi/scsi_eh.h>
  35 #include <scsi/scsi_tcq.h>
  36 #include <scsi/scsi_host.h>
  37 #include <scsi/scsi.h>
  38 #include <scsi/iscsi_proto.h>
  39 #include <scsi/scsi_transport.h>
  40 #include <scsi/scsi_transport_iscsi.h>
  41 #include <scsi/libiscsi.h>
  42
  43 static int iscsi_dbg_lib_conn;
  44 module_param_named(debug_libiscsi_conn, iscsi_dbg_lib_conn, int,
  45                    S_IRUGO | S_IWUSR);
  46 MODULE_PARM_DESC(debug_libiscsi_conn,
  47                  "Turn on debugging for connections in libiscsi module. "
  48                  "Set to 1 to turn on, and zero to turn off. Default is off.");
  49
  50 static int iscsi_dbg_lib_session;
  51 module_param_named(debug_libiscsi_session, iscsi_dbg_lib_session, int,
  52                    S_IRUGO | S_IWUSR);
  53 MODULE_PARM_DESC(debug_libiscsi_session,
  54                  "Turn on debugging for sessions in libiscsi module. "
  55                  "Set to 1 to turn on, and zero to turn off. Default is off.");
  56
  57 static int iscsi_dbg_lib_eh;
  58 module_param_named(debug_libiscsi_eh, iscsi_dbg_lib_eh, int,
  59                    S_IRUGO | S_IWUSR);
  60 MODULE_PARM_DESC(debug_libiscsi_eh,
  61                  "Turn on debugging for error handling in libiscsi module. "
  62                  "Set to 1 to turn on, and zero to turn off. Default is off.");
  63
  64 #define ISCSI_DBG_CONN(_conn, dbg_fmt, arg...)                  \
  65         do {                                                    \
  66                 if (iscsi_dbg_lib_conn)                         \
  67                         iscsi_conn_printk(KERN_INFO, _conn,     \
  68                                              "%s " dbg_fmt,     \
  69                                              __func__, ##arg);  \
  70         } while (0);
  71
  72 #define ISCSI_DBG_SESSION(_session, dbg_fmt, arg...)                    \
  73         do {                                                            \
  74                 if (iscsi_dbg_lib_session)                              \
  75                         iscsi_session_printk(KERN_INFO, _session,       \
  76                                              "%s " dbg_fmt,             \
  77                                              __func__, ##arg);          \
  78         } while (0);
  79
  80 #define ISCSI_DBG_EH(_session, dbg_fmt, arg...)                         \
  81         do {                                                            \
  82                 if (iscsi_dbg_lib_eh)                                   \
  83                         iscsi_session_printk(KERN_INFO, _session,       \
  84                                              "%s " dbg_fmt,             \
  85                                              __func__, ##arg);          \
  86         } while (0);
  87
  88 inline void iscsi_conn_queue_work(struct iscsi_conn *conn)
  89 {
  90         struct Scsi_Host *shost = conn->session->host;
  91         struct iscsi_host *ihost = shost_priv(shost);
  92
  93         if (ihost->workq)
  94                 queue_work(ihost->workq, &conn->xmitwork);
  95 }
  96 EXPORT_SYMBOL_GPL(iscsi_conn_queue_work);
  97
  98 static void __iscsi_update_cmdsn(struct iscsi_session *session,
  99                                  uint32_t exp_cmdsn, uint32_t max_cmdsn)
 100 {
 101         /*
 102          * standard specifies this check for when to update expected and
 103          * max sequence numbers
 104          */
 105         if (iscsi_sna_lt(max_cmdsn, exp_cmdsn - 1))
 106                 return;
 107
 108         if (exp_cmdsn != session->exp_cmdsn &&
 109             !iscsi_sna_lt(exp_cmdsn, session->exp_cmdsn))
 110                 session->exp_cmdsn = exp_cmdsn;
 111
 112         if (max_cmdsn != session->max_cmdsn &&
 113             !iscsi_sna_lt(max_cmdsn, session->max_cmdsn))
 114                 session->max_cmdsn = max_cmdsn;
 115 }
 116
 117 void iscsi_update_cmdsn(struct iscsi_session *session, struct iscsi_nopin *hdr)
 118 {
 119         __iscsi_update_cmdsn(session, be32_to_cpu(hdr->exp_cmdsn),
 120                              be32_to_cpu(hdr->max_cmdsn));
 121 }
 122 EXPORT_SYMBOL_GPL(iscsi_update_cmdsn);
 123
 124 /**
 125  * iscsi_prep_data_out_pdu - initialize Data-Out
 126  * @task: scsi command task
 127  * @r2t: R2T info
 128  * @hdr: iscsi data in pdu
 129  *
 130  * Notes:
 131  *      Initialize Data-Out within this R2T sequence and finds
 132  *      proper data_offset within this SCSI command.
 133  *
 134  *      This function is called with connection lock taken.
 135  **/
 136 void iscsi_prep_data_out_pdu(struct iscsi_task *task, struct iscsi_r2t_info *r2t,
 137                            struct iscsi_data *hdr)
 138 {
 139         struct iscsi_conn *conn = task->conn;
 140         unsigned int left = r2t->data_length - r2t->sent;
 141
 142         task->hdr_len = sizeof(struct iscsi_data);
 143
 144         memset(hdr, 0, sizeof(struct iscsi_data));
 145         hdr->ttt = r2t->ttt;
 146         hdr->datasn = cpu_to_be32(r2t->datasn);
 147         r2t->datasn++;
 148         hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
 149         hdr->lun = task->lun;
 150         hdr->itt = task->hdr_itt;
 151         hdr->exp_statsn = r2t->exp_statsn;
 152         hdr->offset = cpu_to_be32(r2t->data_offset + r2t->sent);
 153         if (left > conn->max_xmit_dlength) {
 154                 hton24(hdr->dlength, conn->max_xmit_dlength);
 155                 r2t->data_count = conn->max_xmit_dlength;
 156                 hdr->flags = 0;
 157         } else {
 158                 hton24(hdr->dlength, left);
 159                 r2t->data_count = left;
 160                 hdr->flags = ISCSI_FLAG_CMD_FINAL;
 161         }
 162         conn->dataout_pdus_cnt++;
 163 }
 164 EXPORT_SYMBOL_GPL(iscsi_prep_data_out_pdu);
 165
 166 static int iscsi_add_hdr(struct iscsi_task *task, unsigned len)
 167 {
 168         unsigned exp_len = task->hdr_len + len;
 169
 170         if (exp_len > task->hdr_max) {
 171                 WARN_ON(1);
 172                 return -EINVAL;
 173         }
 174
 175         WARN_ON(len & (ISCSI_PAD_LEN - 1)); /* caller must pad the AHS */
 176         task->hdr_len = exp_len;
 177         return 0;
 178 }
 179
 180 /*
 181  * make an extended cdb AHS
 182  */
 183 static int iscsi_prep_ecdb_ahs(struct iscsi_task *task)
 184 {
 185         struct scsi_cmnd *cmd = task->sc;
 186         unsigned rlen, pad_len;
 187         unsigned short ahslength;
 188         struct iscsi_ecdb_ahdr *ecdb_ahdr;
 189         int rc;
 190
 191         ecdb_ahdr = iscsi_next_hdr(task);
 192         rlen = cmd->cmd_len - ISCSI_CDB_SIZE;
 193
 194         BUG_ON(rlen > sizeof(ecdb_ahdr->ecdb));
 195         ahslength = rlen + sizeof(ecdb_ahdr->reserved);
 196
 197         pad_len = iscsi_padding(rlen);
 198
 199         rc = iscsi_add_hdr(task, sizeof(ecdb_ahdr->ahslength) +
 200                            sizeof(ecdb_ahdr->ahstype) + ahslength + pad_len);
 201         if (rc)
 202                 return rc;
 203
 204         if (pad_len)
 205                 memset(&ecdb_ahdr->ecdb[rlen], 0, pad_len);
 206
 207         ecdb_ahdr->ahslength = cpu_to_be16(ahslength);
 208         ecdb_ahdr->ahstype = ISCSI_AHSTYPE_CDB;
 209         ecdb_ahdr->reserved = 0;
 210         memcpy(ecdb_ahdr->ecdb, cmd->cmnd + ISCSI_CDB_SIZE, rlen);
 211
 212         ISCSI_DBG_SESSION(task->conn->session,
 213                           "iscsi_prep_ecdb_ahs: varlen_cdb_len %d "
 214                           "rlen %d pad_len %d ahs_length %d iscsi_headers_size "
 215                           "%u\n", cmd->cmd_len, rlen, pad_len, ahslength,
 216                           task->hdr_len);
 217         return 0;
 218 }
 219
 220 static int iscsi_prep_bidi_ahs(struct iscsi_task *task)
 221 {
 222         struct scsi_cmnd *sc = task->sc;
 223         struct iscsi_rlength_ahdr *rlen_ahdr;
 224         int rc;
 225
 226         rlen_ahdr = iscsi_next_hdr(task);
 227         rc = iscsi_add_hdr(task, sizeof(*rlen_ahdr));
 228         if (rc)
 229                 return rc;
 230
 231         rlen_ahdr->ahslength =
 232                 cpu_to_be16(sizeof(rlen_ahdr->read_length) +
 233                                                   sizeof(rlen_ahdr->reserved));
 234         rlen_ahdr->ahstype = ISCSI_AHSTYPE_RLENGTH;
 235         rlen_ahdr->reserved = 0;
 236         rlen_ahdr->read_length = cpu_to_be32(scsi_in(sc)->length);
 237
 238         ISCSI_DBG_SESSION(task->conn->session,
 239                           "bidi-in rlen_ahdr->read_length(%d) "
 240                           "rlen_ahdr->ahslength(%d)\n",
 241                           be32_to_cpu(rlen_ahdr->read_length),
 242                           be16_to_cpu(rlen_ahdr->ahslength));
 243         return 0;
 244 }
 245
 246 /**
 247  * iscsi_check_tmf_restrictions - check if a task is affected by TMF
 248  * @task: iscsi task
 249  * @opcode: opcode to check for
 250  *
 251  * During TMF a task has to be checked if it's affected.
 252  * All unrelated I/O can be passed through, but I/O to the
 253  * affected LUN should be restricted.
 254  * If 'fast_abort' is set we won't be sending any I/O to the
 255  * affected LUN.
 256  * Otherwise the target is waiting for all TTTs to be completed,
 257  * so we have to send all outstanding Data-Out PDUs to the target.
 258  */
 259 static int iscsi_check_tmf_restrictions(struct iscsi_task *task, int opcode)
 260 {
 261         struct iscsi_conn *conn = task->conn;
 262         struct iscsi_tm *tmf = &conn->tmhdr;
 263         u64 hdr_lun;
 264
 265         if (conn->tmf_state == TMF_INITIAL)
 266                 return 0;
 267
 268         if ((tmf->opcode & ISCSI_OPCODE_MASK) != ISCSI_OP_SCSI_TMFUNC)
 269                 return 0;
 270
 271         switch (ISCSI_TM_FUNC_VALUE(tmf)) {
 272         case ISCSI_TM_FUNC_LOGICAL_UNIT_RESET:
 273                 /*
 274                  * Allow PDUs for unrelated LUNs
 275                  */
 276                 hdr_lun = scsilun_to_int(&tmf->lun);
 277                 if (hdr_lun != task->sc->device->lun)
 278                         return 0;
 279                 /* fall through */
 280         case ISCSI_TM_FUNC_TARGET_WARM_RESET:
 281                 /*
 282                  * Fail all SCSI cmd PDUs
 283                  */
 284                 if (opcode != ISCSI_OP_SCSI_DATA_OUT) {
 285                         iscsi_conn_printk(KERN_INFO, conn,
 286                                           "task [op %x itt "
 287                                           "0x%x/0x%x] "
 288                                           "rejected.\n",
 289                                           opcode, task->itt,
 290                                           task->hdr_itt);
 291                         return -EACCES;
 292                 }
 293                 /*
 294                  * And also all data-out PDUs in response to R2T
 295                  * if fast_abort is set.
 296                  */
 297                 if (conn->session->fast_abort) {
 298                         iscsi_conn_printk(KERN_INFO, conn,
 299                                           "task [op %x itt "
 300                                           "0x%x/0x%x] fast abort.\n",
 301                                           opcode, task->itt,
 302                                           task->hdr_itt);
 303                         return -EACCES;
 304                 }
 305                 break;
 306         case ISCSI_TM_FUNC_ABORT_TASK:
 307                 /*
 308                  * the caller has already checked if the task
 309                  * they want to abort was in the pending queue so if
 310                  * we are here the cmd pdu has gone out already, and
 311                  * we will only hit this for data-outs
 312                  */
 313                 if (opcode == ISCSI_OP_SCSI_DATA_OUT &&
 314                     task->hdr_itt == tmf->rtt) {
 315                         ISCSI_DBG_SESSION(conn->session,
 316                                           "Preventing task %x/%x from sending "
 317                                           "data-out due to abort task in "
 318                                           "progress\n", task->itt,
 319                                           task->hdr_itt);
 320                         return -EACCES;
 321                 }
 322                 break;
 323         }
 324
 325         return 0;
 326 }
 327
 328 /**
 329  * iscsi_prep_scsi_cmd_pdu - prep iscsi scsi cmd pdu
 330  * @task: iscsi task
 331  *
 332  * Prep basic iSCSI PDU fields for a scsi cmd pdu. The LLD should set
 333  * fields like dlength or final based on how much data it sends
 334  */
 335 static int iscsi_prep_scsi_cmd_pdu(struct iscsi_task *task)
 336 {
 337         struct iscsi_conn *conn = task->conn;
 338         struct iscsi_session *session = conn->session;
 339         struct scsi_cmnd *sc = task->sc;
 340         struct iscsi_scsi_req *hdr;
 341         unsigned hdrlength, cmd_len, transfer_length;
 342         itt_t itt;
 343         int rc;
 344
 345         rc = iscsi_check_tmf_restrictions(task, ISCSI_OP_SCSI_CMD);
 346         if (rc)
 347                 return rc;
 348
 349         if (conn->session->tt->alloc_pdu) {
 350                 rc = conn->session->tt->alloc_pdu(task, ISCSI_OP_SCSI_CMD);
 351                 if (rc)
 352                         return rc;
 353         }
 354         hdr = (struct iscsi_scsi_req *)task->hdr;
 355         itt = hdr->itt;
 356         memset(hdr, 0, sizeof(*hdr));
 357
 358         if (session->tt->parse_pdu_itt)
 359                 hdr->itt = task->hdr_itt = itt;
 360         else
 361                 hdr->itt = task->hdr_itt = build_itt(task->itt,
 362                                                      task->conn->session->age);
 363         task->hdr_len = 0;
 364         rc = iscsi_add_hdr(task, sizeof(*hdr));
 365         if (rc)
 366                 return rc;
 367         hdr->opcode = ISCSI_OP_SCSI_CMD;
 368         hdr->flags = ISCSI_ATTR_SIMPLE;
 369         int_to_scsilun(sc->device->lun, &hdr->lun);
 370         task->lun = hdr->lun;
 371         hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
 372         cmd_len = sc->cmd_len;
 373         if (cmd_len < ISCSI_CDB_SIZE)
 374                 memset(&hdr->cdb[cmd_len], 0, ISCSI_CDB_SIZE - cmd_len);
 375         else if (cmd_len > ISCSI_CDB_SIZE) {
 376                 rc = iscsi_prep_ecdb_ahs(task);
 377                 if (rc)
 378                         return rc;
 379                 cmd_len = ISCSI_CDB_SIZE;
 380         }
 381         memcpy(hdr->cdb, sc->cmnd, cmd_len);
 382
 383         task->imm_count = 0;
 384         if (scsi_bidi_cmnd(sc)) {
 385                 hdr->flags |= ISCSI_FLAG_CMD_READ;
 386                 rc = iscsi_prep_bidi_ahs(task);
 387                 if (rc)
 388                         return rc;
 389         }
 390
 391         if (scsi_get_prot_op(sc) != SCSI_PROT_NORMAL)
 392                 task->protected = true;
 393
 394         transfer_length = scsi_transfer_length(sc);
 395         hdr->data_length = cpu_to_be32(transfer_length);
 396         if (sc->sc_data_direction == DMA_TO_DEVICE) {
 397                 struct iscsi_r2t_info *r2t = &task->unsol_r2t;
 398
 399                 hdr->flags |= ISCSI_FLAG_CMD_WRITE;
 400                 /*
 401                  * Write counters:
 402                  *
 403                  *      imm_count       bytes to be sent right after
 404                  *                      SCSI PDU Header
 405                  *
 406                  *      unsol_count     bytes(as Data-Out) to be sent
 407                  *                      without R2T ack right after
 408                  *                      immediate data
 409                  *
 410                  *      r2t data_length bytes to be sent via R2T ack's
 411                  *
 412                  *      pad_count       bytes to be sent as zero-padding
 413                  */
 414                 memset(r2t, 0, sizeof(*r2t));
 415
 416                 if (session->imm_data_en) {
 417                         if (transfer_length >= session->first_burst)
 418                                 task->imm_count = min(session->first_burst,
 419                                                         conn->max_xmit_dlength);
 420                         else
 421                                 task->imm_count = min(transfer_length,
 422                                                       conn->max_xmit_dlength);
 423                         hton24(hdr->dlength, task->imm_count);
 424                 } else
 425                         zero_data(hdr->dlength);
 426
 427                 if (!session->initial_r2t_en) {
 428                         r2t->data_length = min(session->first_burst,
 429                                                transfer_length) -
 430                                                task->imm_count;
 431                         r2t->data_offset = task->imm_count;
 432                         r2t->ttt = cpu_to_be32(ISCSI_RESERVED_TAG);
 433                         r2t->exp_statsn = cpu_to_be32(conn->exp_statsn);
 434                 }
 435
 436                 if (!task->unsol_r2t.data_length)
 437                         /* No unsolicit Data-Out's */
 438                         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
 439         } else {
 440                 hdr->flags |= ISCSI_FLAG_CMD_FINAL;
 441                 zero_data(hdr->dlength);
 442
 443                 if (sc->sc_data_direction == DMA_FROM_DEVICE)
 444                         hdr->flags |= ISCSI_FLAG_CMD_READ;
 445         }
 446
 447         /* calculate size of additional header segments (AHSs) */
 448         hdrlength = task->hdr_len - sizeof(*hdr);
 449
 450         WARN_ON(hdrlength & (ISCSI_PAD_LEN-1));
 451         hdrlength /= ISCSI_PAD_LEN;
 452
 453         WARN_ON(hdrlength >= 256);
 454         hdr->hlength = hdrlength & 0xFF;
 455         hdr->cmdsn = task->cmdsn = cpu_to_be32(session->cmdsn);
 456
 457         if (session->tt->init_task && session->tt->init_task(task))
 458                 return -EIO;
 459
 460         task->state = ISCSI_TASK_RUNNING;
 461         session->cmdsn++;
 462
 463         conn->scsicmd_pdus_cnt++;
 464         ISCSI_DBG_SESSION(session, "iscsi prep [%s cid %d sc %p cdb 0x%x "
 465                           "itt 0x%x len %d bidi_len %d cmdsn %d win %d]\n",
 466                           scsi_bidi_cmnd(sc) ? "bidirectional" :
 467                           sc->sc_data_direction == DMA_TO_DEVICE ?
 468                           "write" : "read", conn->id, sc, sc->cmnd[0],
 469                           task->itt, transfer_length,
 470                           scsi_bidi_cmnd(sc) ? scsi_in(sc)->length : 0,
 471                           session->cmdsn,
 472                           session->max_cmdsn - session->exp_cmdsn + 1);
 473         return 0;
 474 }
 475
 476 /**
 477  * iscsi_free_task - free a task
 478  * @task: iscsi cmd task
 479  *
 480  * Must be called with session back_lock.
 481  * This function returns the scsi command to scsi-ml or cleans
 482  * up mgmt tasks then returns the task to the pool.
 483  */
 484 static void iscsi_free_task(struct iscsi_task *task)
 485 {
 486         struct iscsi_conn *conn = task->conn;
 487         struct iscsi_session *session = conn->session;
 488         struct scsi_cmnd *sc = task->sc;
 489         int oldstate = task->state;
 490
 491         ISCSI_DBG_SESSION(session, "freeing task itt 0x%x state %d sc %p\n",
 492                           task->itt, task->state, task->sc);
 493
 494         session->tt->cleanup_task(task);
 495         task->state = ISCSI_TASK_FREE;
 496         task->sc = NULL;
 497         /*
 498          * login task is preallocated so do not free
 499          */
 500         if (conn->login_task == task)
 501                 return;
 502
 503         kfifo_in(&session->cmdpool.queue, (void*)&task, sizeof(void*));
 504
 505         if (sc) {
 506                 /* SCSI eh reuses commands to verify us */
 507                 sc->SCp.ptr = NULL;
 508                 /*
 509                  * queue command may call this to free the task, so
 510                  * it will decide how to return sc to scsi-ml.
 511                  */
 512                 if (oldstate != ISCSI_TASK_REQUEUE_SCSIQ)
 513                         sc->scsi_done(sc);
 514         }
 515 }
 516
 517 void __iscsi_get_task(struct iscsi_task *task)
 518 {
 519         atomic_inc(&task->refcount);
 520 }
 521 EXPORT_SYMBOL_GPL(__iscsi_get_task);
 522
 523 void __iscsi_put_task(struct iscsi_task *task)
 524 {
 525         if (atomic_dec_and_test(&task->refcount))
 526                 iscsi_free_task(task);
 527 }
 528 EXPORT_SYMBOL_GPL(__iscsi_put_task);
 529
 530 void iscsi_put_task(struct iscsi_task *task)
 531 {
 532         struct iscsi_session *session = task->conn->session;
 533
 534         /* regular RX path uses back_lock */
 535         spin_lock_bh(&session->back_lock);
 536         __iscsi_put_task(task);
 537         spin_unlock_bh(&session->back_lock);
 538 }
 539 EXPORT_SYMBOL_GPL(iscsi_put_task);
 540
 541 /**
 542  * iscsi_complete_task - finish a task
 543  * @task: iscsi cmd task
 544  * @state: state to complete task with
 545  *
 546  * Must be called with session back_lock.
 547  */
 548 static void iscsi_complete_task(struct iscsi_task *task, int state)
 549 {
 550         struct iscsi_conn *conn = task->conn;
 551
 552         ISCSI_DBG_SESSION(conn->session,
 553                           "complete task itt 0x%x state %d sc %p\n",
 554                           task->itt, task->state, task->sc);
 555         if (task->state == ISCSI_TASK_COMPLETED ||
 556             task->state == ISCSI_TASK_ABRT_TMF ||
 557             task->state == ISCSI_TASK_ABRT_SESS_RECOV ||
 558             task->state == ISCSI_TASK_REQUEUE_SCSIQ)
 559                 return;
 560         WARN_ON_ONCE(task->state == ISCSI_TASK_FREE);
 561         task->state = state;
 562
 563         spin_lock_bh(&conn->taskqueuelock);
 564         if (!list_empty(&task->running)) {
 565                 pr_debug_once("%s while task on list", __func__);
 566                 list_del_init(&task->running);
 567         }
 568         spin_unlock_bh(&conn->taskqueuelock);
 569
 570         if (conn->task == task)
 571                 conn->task = NULL;
 572
 573         if (conn->ping_task == task)
 574                 conn->ping_task = NULL;
 575
 576         /* release get from queueing */
 577         __iscsi_put_task(task);
 578 }
 579
 580 /**
 581  * iscsi_complete_scsi_task - finish scsi task normally
 582  * @task: iscsi task for scsi cmd
 583  * @exp_cmdsn: expected cmd sn in cpu format
 584  * @max_cmdsn: max cmd sn in cpu format
 585  *
 586  * This is used when drivers do not need or cannot perform
 587  * lower level pdu processing.
 588  *
 589  * Called with session back_lock
 590  */
 591 void iscsi_complete_scsi_task(struct iscsi_task *task,
 592                               uint32_t exp_cmdsn, uint32_t max_cmdsn)
 593 {
 594         struct iscsi_conn *conn = task->conn;
 595
 596         ISCSI_DBG_SESSION(conn->session, "[itt 0x%x]\n", task->itt);
 597
 598         conn->last_recv = jiffies;
 599         __iscsi_update_cmdsn(conn->session, exp_cmdsn, max_cmdsn);
 600         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 601 }
 602 EXPORT_SYMBOL_GPL(iscsi_complete_scsi_task);
 603
 604
 605 /*
 606  * session back_lock must be held and if not called for a task that is
 607  * still pending or from the xmit thread, then xmit thread must
 608  * be suspended.
 609  */
 610 static void fail_scsi_task(struct iscsi_task *task, int err)
 611 {
 612         struct iscsi_conn *conn = task->conn;
 613         struct scsi_cmnd *sc;
 614         int state;
 615
 616         /*
 617          * if a command completes and we get a successful tmf response
 618          * we will hit this because the scsi eh abort code does not take
 619          * a ref to the task.
 620          */
 621         sc = task->sc;
 622         if (!sc)
 623                 return;
 624
 625         if (task->state == ISCSI_TASK_PENDING) {
 626                 /*
 627                  * cmd never made it to the xmit thread, so we should not count
 628                  * the cmd in the sequencing
 629                  */
 630                 conn->session->queued_cmdsn--;
 631                 /* it was never sent so just complete like normal */
 632                 state = ISCSI_TASK_COMPLETED;
 633         } else if (err == DID_TRANSPORT_DISRUPTED)
 634                 state = ISCSI_TASK_ABRT_SESS_RECOV;
 635         else
 636                 state = ISCSI_TASK_ABRT_TMF;
 637
 638         sc->result = err << 16;
 639         if (!scsi_bidi_cmnd(sc))
 640                 scsi_set_resid(sc, scsi_bufflen(sc));
 641         else {
 642                 scsi_out(sc)->resid = scsi_out(sc)->length;
 643                 scsi_in(sc)->resid = scsi_in(sc)->length;
 644         }
 645
 646         /* regular RX path uses back_lock */
 647         spin_lock_bh(&conn->session->back_lock);
 648         iscsi_complete_task(task, state);
 649         spin_unlock_bh(&conn->session->back_lock);
 650 }
 651
 652 static int iscsi_prep_mgmt_task(struct iscsi_conn *conn,
 653                                 struct iscsi_task *task)
 654 {
 655         struct iscsi_session *session = conn->session;
 656         struct iscsi_hdr *hdr = task->hdr;
 657         struct iscsi_nopout *nop = (struct iscsi_nopout *)hdr;
 658         uint8_t opcode = hdr->opcode & ISCSI_OPCODE_MASK;
 659
 660         if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
 661                 return -ENOTCONN;
 662
 663         if (opcode != ISCSI_OP_LOGIN && opcode != ISCSI_OP_TEXT)
 664                 nop->exp_statsn = cpu_to_be32(conn->exp_statsn);
 665         /*
 666          * pre-format CmdSN for outgoing PDU.
 667          */
 668         nop->cmdsn = cpu_to_be32(session->cmdsn);
 669         if (hdr->itt != RESERVED_ITT) {
 670                 /*
 671                  * TODO: We always use immediate for normal session pdus.
 672                  * If we start to send tmfs or nops as non-immediate then
 673                  * we should start checking the cmdsn numbers for mgmt tasks.
 674                  *
 675                  * During discovery sessions iscsid sends TEXT as non immediate,
 676                  * but we always only send one PDU at a time.
 677                  */
 678                 if (conn->c_stage == ISCSI_CONN_STARTED &&
 679                     !(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
 680                         session->queued_cmdsn++;
 681                         session->cmdsn++;
 682                 }
 683         }
 684
 685         if (session->tt->init_task && session->tt->init_task(task))
 686                 return -EIO;
 687
 688         if ((hdr->opcode & ISCSI_OPCODE_MASK) == ISCSI_OP_LOGOUT)
 689                 session->state = ISCSI_STATE_LOGGING_OUT;
 690
 691         task->state = ISCSI_TASK_RUNNING;
 692         ISCSI_DBG_SESSION(session, "mgmtpdu [op 0x%x hdr->itt 0x%x "
 693                           "datalen %d]\n", hdr->opcode & ISCSI_OPCODE_MASK,
 694                           hdr->itt, task->data_count);
 695         return 0;
 696 }
 697
 698 static struct iscsi_task *
 699 __iscsi_conn_send_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 700                       char *data, uint32_t data_size)
 701 {
 702         struct iscsi_session *session = conn->session;
 703         struct iscsi_host *ihost = shost_priv(session->host);
 704         uint8_t opcode = hdr->opcode & ISCSI_OPCODE_MASK;
 705         struct iscsi_task *task;
 706         itt_t itt;
 707
 708         if (session->state == ISCSI_STATE_TERMINATE)
 709                 return NULL;
 710
 711         if (opcode == ISCSI_OP_LOGIN || opcode == ISCSI_OP_TEXT) {
 712                 /*
 713                  * Login and Text are sent serially, in
 714                  * request-followed-by-response sequence.
 715                  * Same task can be used. Same ITT must be used.
 716                  * Note that login_task is preallocated at conn_create().
 717                  */
 718                 if (conn->login_task->state != ISCSI_TASK_FREE) {
 719                         iscsi_conn_printk(KERN_ERR, conn, "Login/Text in "
 720                                           "progress. Cannot start new task.\n");
 721                         return NULL;
 722                 }
 723
 724                 if (data_size > ISCSI_DEF_MAX_RECV_SEG_LEN) {
 725                         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);
 726                         return NULL;
 727                 }
 728
 729                 task = conn->login_task;
 730         } else {
 731                 if (session->state != ISCSI_STATE_LOGGED_IN)
 732                         return NULL;
 733
 734                 if (data_size != 0) {
 735                         iscsi_conn_printk(KERN_ERR, conn, "Can not send data buffer of len %u for op 0x%x\n", data_size, opcode);
 736                         return NULL;
 737                 }
 738
 739                 BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
 740                 BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);
 741
 742                 if (!kfifo_out(&session->cmdpool.queue,
 743                                  (void*)&task, sizeof(void*)))
 744                         return NULL;
 745         }
 746         /*
 747          * released in complete pdu for task we expect a response for, and
 748          * released by the lld when it has transmitted the task for
 749          * pdus we do not expect a response for.
 750          */
 751         atomic_set(&task->refcount, 1);
 752         task->conn = conn;
 753         task->sc = NULL;
 754         INIT_LIST_HEAD(&task->running);
 755         task->state = ISCSI_TASK_PENDING;
 756
 757         if (data_size) {
 758                 memcpy(task->data, data, data_size);
 759                 task->data_count = data_size;
 760         } else
 761                 task->data_count = 0;
 762
 763         if (conn->session->tt->alloc_pdu) {
 764                 if (conn->session->tt->alloc_pdu(task, hdr->opcode)) {
 765                         iscsi_conn_printk(KERN_ERR, conn, "Could not allocate "
 766                                          "pdu for mgmt task.\n");
 767                         goto free_task;
 768                 }
 769         }
 770
 771         itt = task->hdr->itt;
 772         task->hdr_len = sizeof(struct iscsi_hdr);
 773         memcpy(task->hdr, hdr, sizeof(struct iscsi_hdr));
 774
 775         if (hdr->itt != RESERVED_ITT) {
 776                 if (session->tt->parse_pdu_itt)
 777                         task->hdr->itt = itt;
 778                 else
 779                         task->hdr->itt = build_itt(task->itt,
 780                                                    task->conn->session->age);
 781         }
 782
 783         if (!ihost->workq) {
 784                 if (iscsi_prep_mgmt_task(conn, task))
 785                         goto free_task;
 786
 787                 if (session->tt->xmit_task(task))
 788                         goto free_task;
 789         } else {
 790                 spin_lock_bh(&conn->taskqueuelock);
 791                 list_add_tail(&task->running, &conn->mgmtqueue);
 792                 spin_unlock_bh(&conn->taskqueuelock);
 793                 iscsi_conn_queue_work(conn);
 794         }
 795
 796         return task;
 797
 798 free_task:
 799         /* regular RX path uses back_lock */
 800         spin_lock_bh(&session->back_lock);
 801         __iscsi_put_task(task);
 802         spin_unlock_bh(&session->back_lock);
 803         return NULL;
 804 }
 805
 806 int iscsi_conn_send_pdu(struct iscsi_cls_conn *cls_conn, struct iscsi_hdr *hdr,
 807                         char *data, uint32_t data_size)
 808 {
 809         struct iscsi_conn *conn = cls_conn->dd_data;
 810         struct iscsi_session *session = conn->session;
 811         int err = 0;
 812
 813         spin_lock_bh(&session->frwd_lock);
 814         if (!__iscsi_conn_send_pdu(conn, hdr, data, data_size))
 815                 err = -EPERM;
 816         spin_unlock_bh(&session->frwd_lock);
 817         return err;
 818 }
 819 EXPORT_SYMBOL_GPL(iscsi_conn_send_pdu);
 820
 821 /**
 822  * iscsi_cmd_rsp - SCSI Command Response processing
 823  * @conn: iscsi connection
 824  * @hdr: iscsi header
 825  * @task: scsi command task
 826  * @data: cmd data buffer
 827  * @datalen: len of buffer
 828  *
 829  * iscsi_cmd_rsp sets up the scsi_cmnd fields based on the PDU and
 830  * then completes the command and task.
 831  **/
 832 static void iscsi_scsi_cmd_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 833                                struct iscsi_task *task, char *data,
 834                                int datalen)
 835 {
 836         struct iscsi_scsi_rsp *rhdr = (struct iscsi_scsi_rsp *)hdr;
 837         struct iscsi_session *session = conn->session;
 838         struct scsi_cmnd *sc = task->sc;
 839
 840         iscsi_update_cmdsn(session, (struct iscsi_nopin*)rhdr);
 841         conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 842
 843         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 844
 845         if (task->protected) {
 846                 sector_t sector;
 847                 u8 ascq;
 848
 849                 /**
 850                  * Transports that didn't implement check_protection
 851                  * callback but still published T10-PI support to scsi-mid
 852                  * deserve this BUG_ON.
 853                  **/
 854                 BUG_ON(!session->tt->check_protection);
 855
 856                 ascq = session->tt->check_protection(task, &sector);
 857                 if (ascq) {
 858                         sc->result = DRIVER_SENSE << 24 |
 859                                      SAM_STAT_CHECK_CONDITION;
 860                         scsi_build_sense_buffer(1, sc->sense_buffer,
 861                                                 ILLEGAL_REQUEST, 0x10, ascq);
 862                         scsi_set_sense_information(sc->sense_buffer,
 863                                                    SCSI_SENSE_BUFFERSIZE,
 864                                                    sector);
 865                         goto out;
 866                 }
 867         }
 868
 869         if (rhdr->response != ISCSI_STATUS_CMD_COMPLETED) {
 870                 sc->result = DID_ERROR << 16;
 871                 goto out;
 872         }
 873
 874         if (rhdr->cmd_status == SAM_STAT_CHECK_CONDITION) {
 875                 uint16_t senselen;
 876
 877                 if (datalen < 2) {
 878 invalid_datalen:
 879                         iscsi_conn_printk(KERN_ERR,  conn,
 880                                          "Got CHECK_CONDITION but invalid data "
 881                                          "buffer size of %d\n", datalen);
 882                         sc->result = DID_BAD_TARGET << 16;
 883                         goto out;
 884                 }
 885
 886                 senselen = get_unaligned_be16(data);
 887                 if (datalen < senselen)
 888                         goto invalid_datalen;
 889
 890                 memcpy(sc->sense_buffer, data + 2,
 891                        min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
 892                 ISCSI_DBG_SESSION(session, "copied %d bytes of sense\n",
 893                                   min_t(uint16_t, senselen,
 894                                   SCSI_SENSE_BUFFERSIZE));
 895         }
 896
 897         if (rhdr->flags & (ISCSI_FLAG_CMD_BIDI_UNDERFLOW |
 898                            ISCSI_FLAG_CMD_BIDI_OVERFLOW)) {
 899                 int res_count = be32_to_cpu(rhdr->bi_residual_count);
 900
 901                 if (scsi_bidi_cmnd(sc) && res_count > 0 &&
 902                                 (rhdr->flags & ISCSI_FLAG_CMD_BIDI_OVERFLOW ||
 903                                  res_count <= scsi_in(sc)->length))
 904                         scsi_in(sc)->resid = res_count;
 905                 else
 906                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 907         }
 908
 909         if (rhdr->flags & (ISCSI_FLAG_CMD_UNDERFLOW |
 910                            ISCSI_FLAG_CMD_OVERFLOW)) {
 911                 int res_count = be32_to_cpu(rhdr->residual_count);
 912
 913                 if (res_count > 0 &&
 914                     (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
 915                      res_count <= scsi_bufflen(sc)))
 916                         /* write side for bidi or uni-io set_resid */
 917                         scsi_set_resid(sc, res_count);
 918                 else
 919                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 920         }
 921 out:
 922         ISCSI_DBG_SESSION(session, "cmd rsp done [sc %p res %d itt 0x%x]\n",
 923                           sc, sc->result, task->itt);
 924         conn->scsirsp_pdus_cnt++;
 925         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 926 }
 927
 928 /**
 929  * iscsi_data_in_rsp - SCSI Data-In Response processing
 930  * @conn: iscsi connection
 931  * @hdr:  iscsi pdu
 932  * @task: scsi command task
 933  **/
 934 static void
 935 iscsi_data_in_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 936                   struct iscsi_task *task)
 937 {
 938         struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)hdr;
 939         struct scsi_cmnd *sc = task->sc;
 940
 941         if (!(rhdr->flags & ISCSI_FLAG_DATA_STATUS))
 942                 return;
 943
 944         iscsi_update_cmdsn(conn->session, (struct iscsi_nopin *)hdr);
 945         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 946         conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 947         if (rhdr->flags & (ISCSI_FLAG_DATA_UNDERFLOW |
 948                            ISCSI_FLAG_DATA_OVERFLOW)) {
 949                 int res_count = be32_to_cpu(rhdr->residual_count);
 950
 951                 if (res_count > 0 &&
 952                     (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
 953                      res_count <= scsi_in(sc)->length))
 954                         scsi_in(sc)->resid = res_count;
 955                 else
 956                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 957         }
 958
 959         ISCSI_DBG_SESSION(conn->session, "data in with status done "
 960                           "[sc %p res %d itt 0x%x]\n",
 961                           sc, sc->result, task->itt);
 962         conn->scsirsp_pdus_cnt++;
 963         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 964 }
 965
 966 static void iscsi_tmf_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
 967 {
 968         struct iscsi_tm_rsp *tmf = (struct iscsi_tm_rsp *)hdr;
 969
 970         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 971         conn->tmfrsp_pdus_cnt++;
 972
 973         if (conn->tmf_state != TMF_QUEUED)
 974                 return;
 975
 976         if (tmf->response == ISCSI_TMF_RSP_COMPLETE)
 977                 conn->tmf_state = TMF_SUCCESS;
 978         else if (tmf->response == ISCSI_TMF_RSP_NO_TASK)
 979                 conn->tmf_state = TMF_NOT_FOUND;
 980         else
 981                 conn->tmf_state = TMF_FAILED;
 982         wake_up(&conn->ehwait);
 983 }
 984
 985 static int iscsi_send_nopout(struct iscsi_conn *conn, struct iscsi_nopin *rhdr)
 986 {
 987         struct iscsi_nopout hdr;
 988         struct iscsi_task *task;
 989
 990         if (!rhdr && conn->ping_task)
 991                 return -EINVAL;
 992
 993         memset(&hdr, 0, sizeof(struct iscsi_nopout));
 994         hdr.opcode = ISCSI_OP_NOOP_OUT | ISCSI_OP_IMMEDIATE;
 995         hdr.flags = ISCSI_FLAG_CMD_FINAL;
 996
 997         if (rhdr) {
 998                 hdr.lun = rhdr->lun;
 999                 hdr.ttt = rhdr->ttt;
1000                 hdr.itt = RESERVED_ITT;
1001         } else
1002                 hdr.ttt = RESERVED_ITT;
1003
1004         task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)&hdr, NULL, 0);
1005         if (!task) {
1006                 iscsi_conn_printk(KERN_ERR, conn, "Could not send nopout\n");
1007                 return -EIO;
1008         } else if (!rhdr) {
1009                 /* only track our nops */
1010                 conn->ping_task = task;
1011                 conn->last_ping = jiffies;
1012         }
1013
1014         return 0;
1015 }
1016
1017 static int iscsi_nop_out_rsp(struct iscsi_task *task,
1018                              struct iscsi_nopin *nop, char *data, int datalen)
1019 {
1020         struct iscsi_conn *conn = task->conn;
1021         int rc = 0;
1022
1023         if (conn->ping_task != task) {
1024                 /*
1025                  * If this is not in response to one of our
1026                  * nops then it must be from userspace.
1027                  */
1028                 if (iscsi_recv_pdu(conn->cls_conn, (struct iscsi_hdr *)nop,
1029                                    data, datalen))
1030                         rc = ISCSI_ERR_CONN_FAILED;
1031         } else
1032                 mod_timer(&conn->transport_timer, jiffies + conn->recv_timeout);
1033         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1034         return rc;
1035 }
1036
1037 static int iscsi_handle_reject(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1038                                char *data, int datalen)
1039 {
1040         struct iscsi_reject *reject = (struct iscsi_reject *)hdr;
1041         struct iscsi_hdr rejected_pdu;
1042         int opcode, rc = 0;
1043
1044         conn->exp_statsn = be32_to_cpu(reject->statsn) + 1;
1045
1046         if (ntoh24(reject->dlength) > datalen ||
1047             ntoh24(reject->dlength) < sizeof(struct iscsi_hdr)) {
1048                 iscsi_conn_printk(KERN_ERR, conn, "Cannot handle rejected "
1049                                   "pdu. Invalid data length (pdu dlength "
1050                                   "%u, datalen %d\n", ntoh24(reject->dlength),
1051                                   datalen);
1052                 return ISCSI_ERR_PROTO;
1053         }
1054         memcpy(&rejected_pdu, data, sizeof(struct iscsi_hdr));
1055         opcode = rejected_pdu.opcode & ISCSI_OPCODE_MASK;
1056
1057         switch (reject->reason) {
1058         case ISCSI_REASON_DATA_DIGEST_ERROR:
1059                 iscsi_conn_printk(KERN_ERR, conn,
1060                                   "pdu (op 0x%x itt 0x%x) rejected "
1061                                   "due to DataDigest error.\n",
1062                                   opcode, rejected_pdu.itt);
1063                 break;
1064         case ISCSI_REASON_IMM_CMD_REJECT:
1065                 iscsi_conn_printk(KERN_ERR, conn,
1066                                   "pdu (op 0x%x itt 0x%x) rejected. Too many "
1067                                   "immediate commands.\n",
1068                                   opcode, rejected_pdu.itt);
1069                 /*
1070                  * We only send one TMF at a time so if the target could not
1071                  * handle it, then it should get fixed (RFC mandates that
1072                  * a target can handle one immediate TMF per conn).
1073                  *
1074                  * For nops-outs, we could have sent more than one if
1075                  * the target is sending us lots of nop-ins
1076                  */
1077                 if (opcode != ISCSI_OP_NOOP_OUT)
1078                         return 0;
1079
1080                  if (rejected_pdu.itt == cpu_to_be32(ISCSI_RESERVED_TAG)) {
1081                         /*
1082                          * nop-out in response to target's nop-out rejected.
1083                          * Just resend.
1084                          */
1085                         /* In RX path we are under back lock */
1086                         spin_unlock(&conn->session->back_lock);
1087                         spin_lock(&conn->session->frwd_lock);
1088                         iscsi_send_nopout(conn,
1089                                           (struct iscsi_nopin*)&rejected_pdu);
1090                         spin_unlock(&conn->session->frwd_lock);
1091                         spin_lock(&conn->session->back_lock);
1092                 } else {
1093                         struct iscsi_task *task;
1094                         /*
1095                          * Our nop as ping got dropped. We know the target
1096                          * and transport are ok so just clean up
1097                          */
1098                         task = iscsi_itt_to_task(conn, rejected_pdu.itt);
1099                         if (!task) {
1100                                 iscsi_conn_printk(KERN_ERR, conn,
1101                                                  "Invalid pdu reject. Could "
1102                                                  "not lookup rejected task.\n");
1103                                 rc = ISCSI_ERR_BAD_ITT;
1104                         } else
1105                                 rc = iscsi_nop_out_rsp(task,
1106                                         (struct iscsi_nopin*)&rejected_pdu,
1107                                         NULL, 0);
1108                 }
1109                 break;
1110         default:
1111                 iscsi_conn_printk(KERN_ERR, conn,
1112                                   "pdu (op 0x%x itt 0x%x) rejected. Reason "
1113                                   "code 0x%x\n", rejected_pdu.opcode,
1114                                   rejected_pdu.itt, reject->reason);
1115                 break;
1116         }
1117         return rc;
1118 }
1119
1120 /**
1121  * iscsi_itt_to_task - look up task by itt
1122  * @conn: iscsi connection
1123  * @itt: itt
1124  *
1125  * This should be used for mgmt tasks like login and nops, or if
1126  * the LDD's itt space does not include the session age.
1127  *
1128  * The session back_lock must be held.
1129  */
1130 struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *conn, itt_t itt)
1131 {
1132         struct iscsi_session *session = conn->session;
1133         int i;
1134
1135         if (itt == RESERVED_ITT)
1136                 return NULL;
1137
1138         if (session->tt->parse_pdu_itt)
1139                 session->tt->parse_pdu_itt(conn, itt, &i, NULL);
1140         else
1141                 i = get_itt(itt);
1142         if (i >= session->cmds_max)
1143                 return NULL;
1144
1145         return session->cmds[i];
1146 }
1147 EXPORT_SYMBOL_GPL(iscsi_itt_to_task);
1148
1149 /**
1150  * __iscsi_complete_pdu - complete pdu
1151  * @conn: iscsi conn
1152  * @hdr: iscsi header
1153  * @data: data buffer
1154  * @datalen: len of data buffer
1155  *
1156  * Completes pdu processing by freeing any resources allocated at
1157  * queuecommand or send generic. session back_lock must be held and verify
1158  * itt must have been called.
1159  */
1160 int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1161                          char *data, int datalen)
1162 {
1163         struct iscsi_session *session = conn->session;
1164         int opcode = hdr->opcode & ISCSI_OPCODE_MASK, rc = 0;
1165         struct iscsi_task *task;
1166         uint32_t itt;
1167
1168         conn->last_recv = jiffies;
1169         rc = iscsi_verify_itt(conn, hdr->itt);
1170         if (rc)
1171                 return rc;
1172
1173         if (hdr->itt != RESERVED_ITT)
1174                 itt = get_itt(hdr->itt);
1175         else
1176                 itt = ~0U;
1177
1178         ISCSI_DBG_SESSION(session, "[op 0x%x cid %d itt 0x%x len %d]\n",
1179                           opcode, conn->id, itt, datalen);
1180
1181         if (itt == ~0U) {
1182                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1183
1184                 switch(opcode) {
1185                 case ISCSI_OP_NOOP_IN:
1186                         if (datalen) {
1187                                 rc = ISCSI_ERR_PROTO;
1188                                 break;
1189                         }
1190
1191                         if (hdr->ttt == cpu_to_be32(ISCSI_RESERVED_TAG))
1192                                 break;
1193
1194                         /* In RX path we are under back lock */
1195                         spin_unlock(&session->back_lock);
1196                         spin_lock(&session->frwd_lock);
1197                         iscsi_send_nopout(conn, (struct iscsi_nopin*)hdr);
1198                         spin_unlock(&session->frwd_lock);
1199                         spin_lock(&session->back_lock);
1200                         break;
1201                 case ISCSI_OP_REJECT:
1202                         rc = iscsi_handle_reject(conn, hdr, data, datalen);
1203                         break;
1204                 case ISCSI_OP_ASYNC_EVENT:
1205                         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1206                         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
1207                                 rc = ISCSI_ERR_CONN_FAILED;
1208                         break;
1209                 default:
1210                         rc = ISCSI_ERR_BAD_OPCODE;
1211                         break;
1212                 }
1213                 goto out;
1214         }
1215
1216         switch(opcode) {
1217         case ISCSI_OP_SCSI_CMD_RSP:
1218         case ISCSI_OP_SCSI_DATA_IN:
1219                 task = iscsi_itt_to_ctask(conn, hdr->itt);
1220                 if (!task)
1221                         return ISCSI_ERR_BAD_ITT;
1222                 task->last_xfer = jiffies;
1223                 break;
1224         case ISCSI_OP_R2T:
1225                 /*
1226                  * LLD handles R2Ts if they need to.
1227                  */
1228                 return 0;
1229         case ISCSI_OP_LOGOUT_RSP:
1230         case ISCSI_OP_LOGIN_RSP:
1231         case ISCSI_OP_TEXT_RSP:
1232         case ISCSI_OP_SCSI_TMFUNC_RSP:
1233         case ISCSI_OP_NOOP_IN:
1234                 task = iscsi_itt_to_task(conn, hdr->itt);
1235                 if (!task)
1236                         return ISCSI_ERR_BAD_ITT;
1237                 break;
1238         default:
1239                 return ISCSI_ERR_BAD_OPCODE;
1240         }
1241
1242         switch(opcode) {
1243         case ISCSI_OP_SCSI_CMD_RSP:
1244                 iscsi_scsi_cmd_rsp(conn, hdr, task, data, datalen);
1245                 break;
1246         case ISCSI_OP_SCSI_DATA_IN:
1247                 iscsi_data_in_rsp(conn, hdr, task);
1248                 break;
1249         case ISCSI_OP_LOGOUT_RSP:
1250                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1251                 if (datalen) {
1252                         rc = ISCSI_ERR_PROTO;
1253                         break;
1254                 }
1255                 conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1256                 goto recv_pdu;
1257         case ISCSI_OP_LOGIN_RSP:
1258         case ISCSI_OP_TEXT_RSP:
1259                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1260                 /*
1261                  * login related PDU's exp_statsn is handled in
1262                  * userspace
1263                  */
1264                 goto recv_pdu;
1265         case ISCSI_OP_SCSI_TMFUNC_RSP:
1266                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1267                 if (datalen) {
1268                         rc = ISCSI_ERR_PROTO;
1269                         break;
1270                 }
1271
1272                 iscsi_tmf_rsp(conn, hdr);
1273                 iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1274                 break;
1275         case ISCSI_OP_NOOP_IN:
1276                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1277                 if (hdr->ttt != cpu_to_be32(ISCSI_RESERVED_TAG) || datalen) {
1278                         rc = ISCSI_ERR_PROTO;
1279                         break;
1280                 }
1281                 conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1282
1283                 rc = iscsi_nop_out_rsp(task, (struct iscsi_nopin*)hdr,
1284                                        data, datalen);
1285                 break;
1286         default:
1287                 rc = ISCSI_ERR_BAD_OPCODE;
1288                 break;
1289         }
1290
1291 out:
1292         return rc;
1293 recv_pdu:
1294         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
1295                 rc = ISCSI_ERR_CONN_FAILED;
1296         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1297         return rc;
1298 }
1299 EXPORT_SYMBOL_GPL(__iscsi_complete_pdu);
1300
1301 int iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1302                        char *data, int datalen)
1303 {
1304         int rc;
1305
1306         spin_lock(&conn->session->back_lock);
1307         rc = __iscsi_complete_pdu(conn, hdr, data, datalen);
1308         spin_unlock(&conn->session->back_lock);
1309         return rc;
1310 }
1311 EXPORT_SYMBOL_GPL(iscsi_complete_pdu);
1312
1313 int iscsi_verify_itt(struct iscsi_conn *conn, itt_t itt)
1314 {
1315         struct iscsi_session *session = conn->session;
1316         int age = 0, i = 0;
1317
1318         if (itt == RESERVED_ITT)
1319                 return 0;
1320
1321         if (session->tt->parse_pdu_itt)
1322                 session->tt->parse_pdu_itt(conn, itt, &i, &age);
1323         else {
1324                 i = get_itt(itt);
1325                 age = ((__force u32)itt >> ISCSI_AGE_SHIFT) & ISCSI_AGE_MASK;
1326         }
1327
1328         if (age != session->age) {
1329                 iscsi_conn_printk(KERN_ERR, conn,
1330                                   "received itt %x expected session age (%x)\n",
1331                                   (__force u32)itt, session->age);
1332                 return ISCSI_ERR_BAD_ITT;
1333         }
1334
1335         if (i >= session->cmds_max) {
1336                 iscsi_conn_printk(KERN_ERR, conn,
1337                                   "received invalid itt index %u (max cmds "
1338                                    "%u.\n", i, session->cmds_max);
1339                 return ISCSI_ERR_BAD_ITT;
1340         }
1341         return 0;
1342 }
1343 EXPORT_SYMBOL_GPL(iscsi_verify_itt);
1344
1345 /**
1346  * iscsi_itt_to_ctask - look up ctask by itt
1347  * @conn: iscsi connection
1348  * @itt: itt
1349  *
1350  * This should be used for cmd tasks.
1351  *
1352  * The session back_lock must be held.
1353  */
1354 struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *conn, itt_t itt)
1355 {
1356         struct iscsi_task *task;
1357
1358         if (iscsi_verify_itt(conn, itt))
1359                 return NULL;
1360
1361         task = iscsi_itt_to_task(conn, itt);
1362         if (!task || !task->sc)
1363                 return NULL;
1364
1365         if (task->sc->SCp.phase != conn->session->age) {
1366                 iscsi_session_printk(KERN_ERR, conn->session,
1367                                   "task's session age %d, expected %d\n",
1368                                   task->sc->SCp.phase, conn->session->age);
1369                 return NULL;
1370         }
1371
1372         return task;
1373 }
1374 EXPORT_SYMBOL_GPL(iscsi_itt_to_ctask);
1375
1376 void iscsi_session_failure(struct iscsi_session *session,
1377                            enum iscsi_err err)
1378 {
1379         struct iscsi_conn *conn;
1380         struct device *dev;
1381
1382         spin_lock_bh(&session->frwd_lock);
1383         conn = session->leadconn;
1384         if (session->state == ISCSI_STATE_TERMINATE || !conn) {
1385                 spin_unlock_bh(&session->frwd_lock);
1386                 return;
1387         }
1388
1389         dev = get_device(&conn->cls_conn->dev);
1390         spin_unlock_bh(&session->frwd_lock);
1391         if (!dev)
1392                 return;
1393         /*
1394          * if the host is being removed bypass the connection
1395          * recovery initialization because we are going to kill
1396          * the session.
1397          */
1398         if (err == ISCSI_ERR_INVALID_HOST)
1399                 iscsi_conn_error_event(conn->cls_conn, err);
1400         else
1401                 iscsi_conn_failure(conn, err);
1402         put_device(dev);
1403 }
1404 EXPORT_SYMBOL_GPL(iscsi_session_failure);
1405
1406 void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err)
1407 {
1408         struct iscsi_session *session = conn->session;
1409
1410         spin_lock_bh(&session->frwd_lock);
1411         if (session->state == ISCSI_STATE_FAILED) {
1412                 spin_unlock_bh(&session->frwd_lock);
1413                 return;
1414         }
1415
1416         if (conn->stop_stage == 0)
1417                 session->state = ISCSI_STATE_FAILED;
1418         spin_unlock_bh(&session->frwd_lock);
1419
1420         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1421         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
1422         iscsi_conn_error_event(conn->cls_conn, err);
1423 }
1424 EXPORT_SYMBOL_GPL(iscsi_conn_failure);
1425
1426 static int iscsi_check_cmdsn_window_closed(struct iscsi_conn *conn)
1427 {
1428         struct iscsi_session *session = conn->session;
1429
1430         /*
1431          * Check for iSCSI window and take care of CmdSN wrap-around
1432          */
1433         if (!iscsi_sna_lte(session->queued_cmdsn, session->max_cmdsn)) {
1434                 ISCSI_DBG_SESSION(session, "iSCSI CmdSN closed. ExpCmdSn "
1435                                   "%u MaxCmdSN %u CmdSN %u/%u\n",
1436                                   session->exp_cmdsn, session->max_cmdsn,
1437                                   session->cmdsn, session->queued_cmdsn);
1438                 return -ENOSPC;
1439         }
1440         return 0;
1441 }
1442
1443 static int iscsi_xmit_task(struct iscsi_conn *conn)
1444 {
1445         struct iscsi_task *task = conn->task;
1446         int rc;
1447
1448         if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx))
1449                 return -ENODATA;
1450
1451         spin_lock_bh(&conn->session->back_lock);
1452         if (conn->task == NULL) {
1453                 spin_unlock_bh(&conn->session->back_lock);
1454                 return -ENODATA;
1455         }
1456         __iscsi_get_task(task);
1457         spin_unlock_bh(&conn->session->back_lock);
1458         spin_unlock_bh(&conn->session->frwd_lock);
1459         rc = conn->session->tt->xmit_task(task);
1460         spin_lock_bh(&conn->session->frwd_lock);
1461         if (!rc) {
1462                 /* done with this task */
1463                 task->last_xfer = jiffies;
1464                 conn->task = NULL;
1465         }
1466         /* regular RX path uses back_lock */
1467         spin_lock(&conn->session->back_lock);
1468         __iscsi_put_task(task);
1469         spin_unlock(&conn->session->back_lock);
1470         return rc;
1471 }
1472
1473 /**
1474  * iscsi_requeue_task - requeue task to run from session workqueue
1475  * @task: task to requeue
1476  *
1477  * LLDs that need to run a task from the session workqueue should call
1478  * this. The session frwd_lock must be held. This should only be called
1479  * by software drivers.
1480  */
1481 void iscsi_requeue_task(struct iscsi_task *task)
1482 {
1483         struct iscsi_conn *conn = task->conn;
1484
1485         /*
1486          * this may be on the requeue list already if the xmit_task callout
1487          * is handling the r2ts while we are adding new ones
1488          */
1489         spin_lock_bh(&conn->taskqueuelock);
1490         if (list_empty(&task->running))
1491                 list_add_tail(&task->running, &conn->requeue);
1492         spin_unlock_bh(&conn->taskqueuelock);
1493         iscsi_conn_queue_work(conn);
1494 }
1495 EXPORT_SYMBOL_GPL(iscsi_requeue_task);
1496
1497 /**
1498  * iscsi_data_xmit - xmit any command into the scheduled connection
1499  * @conn: iscsi connection
1500  *
1501  * Notes:
1502  *      The function can return -EAGAIN in which case the caller must
1503  *      re-schedule it again later or recover. '0' return code means
1504  *      successful xmit.
1505  **/
1506 static int iscsi_data_xmit(struct iscsi_conn *conn)
1507 {
1508         struct iscsi_task *task;
1509         int rc = 0;
1510
1511         spin_lock_bh(&conn->session->frwd_lock);
1512         if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx)) {
1513                 ISCSI_DBG_SESSION(conn->session, "Tx suspended!\n");
1514                 spin_unlock_bh(&conn->session->frwd_lock);
1515                 return -ENODATA;
1516         }
1517
1518         if (conn->task) {
1519                 rc = iscsi_xmit_task(conn);
1520                 if (rc)
1521                         goto done;
1522         }
1523
1524         /*
1525          * process mgmt pdus like nops before commands since we should
1526          * only have one nop-out as a ping from us and targets should not
1527          * overflow us with nop-ins
1528          */
1529         spin_lock_bh(&conn->taskqueuelock);
1530 check_mgmt:
1531         while (!list_empty(&conn->mgmtqueue)) {
1532                 conn->task = list_entry(conn->mgmtqueue.next,
1533                                          struct iscsi_task, running);
1534                 list_del_init(&conn->task->running);
1535                 spin_unlock_bh(&conn->taskqueuelock);
1536                 if (iscsi_prep_mgmt_task(conn, conn->task)) {
1537                         /* regular RX path uses back_lock */
1538                         spin_lock_bh(&conn->session->back_lock);
1539                         __iscsi_put_task(conn->task);
1540                         spin_unlock_bh(&conn->session->back_lock);
1541                         conn->task = NULL;
1542                         spin_lock_bh(&conn->taskqueuelock);
1543                         continue;
1544                 }
1545                 rc = iscsi_xmit_task(conn);
1546                 if (rc)
1547                         goto done;
1548                 spin_lock_bh(&conn->taskqueuelock);
1549         }
1550
1551         /* process pending command queue */
1552         while (!list_empty(&conn->cmdqueue)) {
1553                 conn->task = list_entry(conn->cmdqueue.next, struct iscsi_task,
1554                                         running);
1555                 list_del_init(&conn->task->running);
1556                 spin_unlock_bh(&conn->taskqueuelock);
1557                 if (conn->session->state == ISCSI_STATE_LOGGING_OUT) {
1558                         fail_scsi_task(conn->task, DID_IMM_RETRY);
1559                         spin_lock_bh(&conn->taskqueuelock);
1560                         continue;
1561                 }
1562                 rc = iscsi_prep_scsi_cmd_pdu(conn->task);
1563                 if (rc) {
1564                         if (rc == -ENOMEM || rc == -EACCES) {
1565                                 spin_lock_bh(&conn->taskqueuelock);
1566                                 list_add_tail(&conn->task->running,
1567                                               &conn->cmdqueue);
1568                                 conn->task = NULL;
1569                                 spin_unlock_bh(&conn->taskqueuelock);
1570                                 goto done;
1571                         } else
1572                                 fail_scsi_task(conn->task, DID_ABORT);
1573                         spin_lock_bh(&conn->taskqueuelock);
1574                         continue;
1575                 }
1576                 rc = iscsi_xmit_task(conn);
1577                 if (rc)
1578                         goto done;
1579                 /*
1580                  * we could continuously get new task requests so
1581                  * we need to check the mgmt queue for nops that need to
1582                  * be sent to aviod starvation
1583                  */
1584                 spin_lock_bh(&conn->taskqueuelock);
1585                 if (!list_empty(&conn->mgmtqueue))
1586                         goto check_mgmt;
1587         }
1588
1589         while (!list_empty(&conn->requeue)) {
1590                 /*
1591                  * we always do fastlogout - conn stop code will clean up.
1592                  */
1593                 if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
1594                         break;
1595
1596                 task = list_entry(conn->requeue.next, struct iscsi_task,
1597                                   running);
1598                 if (iscsi_check_tmf_restrictions(task, ISCSI_OP_SCSI_DATA_OUT))
1599                         break;
1600
1601                 conn->task = task;
1602                 list_del_init(&conn->task->running);
1603                 conn->task->state = ISCSI_TASK_RUNNING;
1604                 spin_unlock_bh(&conn->taskqueuelock);
1605                 rc = iscsi_xmit_task(conn);
1606                 if (rc)
1607                         goto done;
1608                 spin_lock_bh(&conn->taskqueuelock);
1609                 if (!list_empty(&conn->mgmtqueue))
1610                         goto check_mgmt;
1611         }
1612         spin_unlock_bh(&conn->taskqueuelock);
1613         spin_unlock_bh(&conn->session->frwd_lock);
1614         return -ENODATA;
1615
1616 done:
1617         spin_unlock_bh(&conn->session->frwd_lock);
1618         return rc;
1619 }
1620
1621 static void iscsi_xmitworker(struct work_struct *work)
1622 {
1623         struct iscsi_conn *conn =
1624                 container_of(work, struct iscsi_conn, xmitwork);
1625         int rc;
1626         /*
1627          * serialize Xmit worker on a per-connection basis.
1628          */
1629         do {
1630                 rc = iscsi_data_xmit(conn);
1631         } while (rc >= 0 || rc == -EAGAIN);
1632 }
1633
1634 static inline struct iscsi_task *iscsi_alloc_task(struct iscsi_conn *conn,
1635                                                   struct scsi_cmnd *sc)
1636 {
1637         struct iscsi_task *task;
1638
1639         if (!kfifo_out(&conn->session->cmdpool.queue,
1640                          (void *) &task, sizeof(void *)))
1641                 return NULL;
1642
1643         sc->SCp.phase = conn->session->age;
1644         sc->SCp.ptr = (char *) task;
1645
1646         atomic_set(&task->refcount, 1);
1647         task->state = ISCSI_TASK_PENDING;
1648         task->conn = conn;
1649         task->sc = sc;
1650         task->have_checked_conn = false;
1651         task->last_timeout = jiffies;
1652         task->last_xfer = jiffies;
1653         task->protected = false;
1654         INIT_LIST_HEAD(&task->running);
1655         return task;
1656 }
1657
1658 enum {
1659         FAILURE_BAD_HOST = 1,
1660         FAILURE_SESSION_FAILED,
1661         FAILURE_SESSION_FREED,
1662         FAILURE_WINDOW_CLOSED,
1663         FAILURE_OOM,
1664         FAILURE_SESSION_TERMINATE,
1665         FAILURE_SESSION_IN_RECOVERY,
1666         FAILURE_SESSION_RECOVERY_TIMEOUT,
1667         FAILURE_SESSION_LOGGING_OUT,
1668         FAILURE_SESSION_NOT_READY,
1669 };
1670
1671 int iscsi_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *sc)
1672 {
1673         struct iscsi_cls_session *cls_session;
1674         struct iscsi_host *ihost;
1675         int reason = 0;
1676         struct iscsi_session *session;
1677         struct iscsi_conn *conn;
1678         struct iscsi_task *task = NULL;
1679
1680         sc->result = 0;
1681         sc->SCp.ptr = NULL;
1682
1683         ihost = shost_priv(host);
1684
1685         cls_session = starget_to_session(scsi_target(sc->device));
1686         session = cls_session->dd_data;
1687         spin_lock_bh(&session->frwd_lock);
1688
1689         reason = iscsi_session_chkready(cls_session);
1690         if (reason) {
1691                 sc->result = reason;
1692                 goto fault;
1693         }
1694
1695         if (session->state != ISCSI_STATE_LOGGED_IN) {
1696                 /*
1697                  * to handle the race between when we set the recovery state
1698                  * and block the session we requeue here (commands could
1699                  * be entering our queuecommand while a block is starting
1700                  * up because the block code is not locked)
1701                  */
1702                 switch (session->state) {
1703                 case ISCSI_STATE_FAILED:
1704                         /*
1705                          * cmds should fail during shutdown, if the session
1706                          * state is bad, allowing completion to happen
1707                          */
1708                         if (unlikely(system_state != SYSTEM_RUNNING)) {
1709                                 reason = FAILURE_SESSION_FAILED;
1710                                 sc->result = DID_NO_CONNECT << 16;
1711                                 break;
1712                         }
1713                 case ISCSI_STATE_IN_RECOVERY:
1714                         reason = FAILURE_SESSION_IN_RECOVERY;
1715                         sc->result = DID_IMM_RETRY << 16;
1716                         break;
1717                 case ISCSI_STATE_LOGGING_OUT:
1718                         reason = FAILURE_SESSION_LOGGING_OUT;
1719                         sc->result = DID_IMM_RETRY << 16;
1720                         break;
1721                 case ISCSI_STATE_RECOVERY_FAILED:
1722                         reason = FAILURE_SESSION_RECOVERY_TIMEOUT;
1723                         sc->result = DID_TRANSPORT_FAILFAST << 16;
1724                         break;
1725                 case ISCSI_STATE_TERMINATE:
1726                         reason = FAILURE_SESSION_TERMINATE;
1727                         sc->result = DID_NO_CONNECT << 16;
1728                         break;
1729                 default:
1730                         reason = FAILURE_SESSION_FREED;
1731                         sc->result = DID_NO_CONNECT << 16;
1732                 }
1733                 goto fault;
1734         }
1735
1736         conn = session->leadconn;
1737         if (!conn) {
1738                 reason = FAILURE_SESSION_FREED;
1739                 sc->result = DID_NO_CONNECT << 16;
1740                 goto fault;
1741         }
1742
1743         if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx)) {
1744                 reason = FAILURE_SESSION_IN_RECOVERY;
1745                 sc->result = DID_REQUEUE << 16;
1746                 goto fault;
1747         }
1748
1749         if (iscsi_check_cmdsn_window_closed(conn)) {
1750                 reason = FAILURE_WINDOW_CLOSED;
1751                 goto reject;
1752         }
1753
1754         task = iscsi_alloc_task(conn, sc);
1755         if (!task) {
1756                 reason = FAILURE_OOM;
1757                 goto reject;
1758         }
1759
1760         if (!ihost->workq) {
1761                 reason = iscsi_prep_scsi_cmd_pdu(task);
1762                 if (reason) {
1763                         if (reason == -ENOMEM ||  reason == -EACCES) {
1764                                 reason = FAILURE_OOM;
1765                                 goto prepd_reject;
1766                         } else {
1767                                 sc->result = DID_ABORT << 16;
1768                                 goto prepd_fault;
1769                         }
1770                 }
1771                 if (session->tt->xmit_task(task)) {
1772                         session->cmdsn--;
1773                         reason = FAILURE_SESSION_NOT_READY;
1774                         goto prepd_reject;
1775                 }
1776         } else {
1777                 spin_lock_bh(&conn->taskqueuelock);
1778                 list_add_tail(&task->running, &conn->cmdqueue);
1779                 spin_unlock_bh(&conn->taskqueuelock);
1780                 iscsi_conn_queue_work(conn);
1781         }
1782
1783         session->queued_cmdsn++;
1784         spin_unlock_bh(&session->frwd_lock);
1785         return 0;
1786
1787 prepd_reject:
1788         iscsi_complete_task(task, ISCSI_TASK_REQUEUE_SCSIQ);
1789 reject:
1790         spin_unlock_bh(&session->frwd_lock);
1791         ISCSI_DBG_SESSION(session, "cmd 0x%x rejected (%d)\n",
1792                           sc->cmnd[0], reason);
1793         return SCSI_MLQUEUE_TARGET_BUSY;
1794
1795 prepd_fault:
1796         iscsi_complete_task(task, ISCSI_TASK_REQUEUE_SCSIQ);
1797 fault:
1798         spin_unlock_bh(&session->frwd_lock);
1799         ISCSI_DBG_SESSION(session, "iscsi: cmd 0x%x is not queued (%d)\n",
1800                           sc->cmnd[0], reason);
1801         if (!scsi_bidi_cmnd(sc))
1802                 scsi_set_resid(sc, scsi_bufflen(sc));
1803         else {
1804                 scsi_out(sc)->resid = scsi_out(sc)->length;
1805                 scsi_in(sc)->resid = scsi_in(sc)->length;
1806         }
1807         sc->scsi_done(sc);
1808         return 0;
1809 }
1810 EXPORT_SYMBOL_GPL(iscsi_queuecommand);
1811
1812 int iscsi_target_alloc(struct scsi_target *starget)
1813 {
1814         struct iscsi_cls_session *cls_session = starget_to_session(starget);
1815         struct iscsi_session *session = cls_session->dd_data;
1816
1817         starget->can_queue = session->scsi_cmds_max;
1818         return 0;
1819 }
1820 EXPORT_SYMBOL_GPL(iscsi_target_alloc);
1821
1822 static void iscsi_tmf_timedout(unsigned long data)
1823 {
1824         struct iscsi_conn *conn = (struct iscsi_conn *)data;
1825         struct iscsi_session *session = conn->session;
1826
1827         spin_lock(&session->frwd_lock);
1828         if (conn->tmf_state == TMF_QUEUED) {
1829                 conn->tmf_state = TMF_TIMEDOUT;
1830                 ISCSI_DBG_EH(session, "tmf timedout\n");
1831                 /* unblock eh_abort() */
1832                 wake_up(&conn->ehwait);
1833         }
1834         spin_unlock(&session->frwd_lock);
1835 }
1836
1837 static int iscsi_exec_task_mgmt_fn(struct iscsi_conn *conn,
1838                                    struct iscsi_tm *hdr, int age,
1839                                    int timeout)
1840 {
1841         struct iscsi_session *session = conn->session;
1842         struct iscsi_task *task;
1843
1844         task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)hdr,
1845                                       NULL, 0);
1846         if (!task) {
1847                 spin_unlock_bh(&session->frwd_lock);
1848                 iscsi_conn_printk(KERN_ERR, conn, "Could not send TMF.\n");
1849                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1850                 spin_lock_bh(&session->frwd_lock);
1851                 return -EPERM;
1852         }
1853         conn->tmfcmd_pdus_cnt++;
1854         conn->tmf_timer.expires = timeout * HZ + jiffies;
1855         conn->tmf_timer.function = iscsi_tmf_timedout;
1856         conn->tmf_timer.data = (unsigned long)conn;
1857         add_timer(&conn->tmf_timer);
1858         ISCSI_DBG_EH(session, "tmf set timeout\n");
1859
1860         spin_unlock_bh(&session->frwd_lock);
1861         mutex_unlock(&session->eh_mutex);
1862
1863         /*
1864          * block eh thread until:
1865          *
1866          * 1) tmf response
1867          * 2) tmf timeout
1868          * 3) session is terminated or restarted or userspace has
1869          * given up on recovery
1870          */
1871         wait_event_interruptible(conn->ehwait, age != session->age ||
1872                                  session->state != ISCSI_STATE_LOGGED_IN ||
1873                                  conn->tmf_state != TMF_QUEUED);
1874         if (signal_pending(current))
1875                 flush_signals(current);
1876         del_timer_sync(&conn->tmf_timer);
1877
1878         mutex_lock(&session->eh_mutex);
1879         spin_lock_bh(&session->frwd_lock);
1880         /* if the session drops it will clean up the task */
1881         if (age != session->age ||
1882             session->state != ISCSI_STATE_LOGGED_IN)
1883                 return -ENOTCONN;
1884         return 0;
1885 }
1886
1887 /*
1888  * Fail commands. session lock held and recv side suspended and xmit
1889  * thread flushed
1890  */
1891 static void fail_scsi_tasks(struct iscsi_conn *conn, u64 lun, int error)
1892 {
1893         struct iscsi_task *task;
1894         int i;
1895
1896         for (i = 0; i < conn->session->cmds_max; i++) {
1897                 task = conn->session->cmds[i];
1898                 if (!task->sc || task->state == ISCSI_TASK_FREE)
1899                         continue;
1900
1901                 if (lun != -1 && lun != task->sc->device->lun)
1902                         continue;
1903
1904                 ISCSI_DBG_SESSION(conn->session,
1905                                   "failing sc %p itt 0x%x state %d\n",
1906                                   task->sc, task->itt, task->state);
1907                 fail_scsi_task(task, error);
1908         }
1909 }
1910
1911 /**
1912  * iscsi_suspend_queue - suspend iscsi_queuecommand
1913  * @conn: iscsi conn to stop queueing IO on
1914  *
1915  * This grabs the session frwd_lock to make sure no one is in
1916  * xmit_task/queuecommand, and then sets suspend to prevent
1917  * new commands from being queued. This only needs to be called
1918  * by offload drivers that need to sync a path like ep disconnect
1919  * with the iscsi_queuecommand/xmit_task. To start IO again libiscsi
1920  * will call iscsi_start_tx and iscsi_unblock_session when in FFP.
1921  */
1922 void iscsi_suspend_queue(struct iscsi_conn *conn)
1923 {
1924         spin_lock_bh(&conn->session->frwd_lock);
1925         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1926         spin_unlock_bh(&conn->session->frwd_lock);
1927 }
1928 EXPORT_SYMBOL_GPL(iscsi_suspend_queue);
1929
1930 /**
1931  * iscsi_suspend_tx - suspend iscsi_data_xmit
1932  * @conn: iscsi conn tp stop processing IO on.
1933  *
1934  * This function sets the suspend bit to prevent iscsi_data_xmit
1935  * from sending new IO, and if work is queued on the xmit thread
1936  * it will wait for it to be completed.
1937  */
1938 void iscsi_suspend_tx(struct iscsi_conn *conn)
1939 {
1940         struct Scsi_Host *shost = conn->session->host;
1941         struct iscsi_host *ihost = shost_priv(shost);
1942
1943         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1944         if (ihost->workq)
1945                 flush_workqueue(ihost->workq);
1946 }
1947 EXPORT_SYMBOL_GPL(iscsi_suspend_tx);
1948
1949 static void iscsi_start_tx(struct iscsi_conn *conn)
1950 {
1951         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1952         iscsi_conn_queue_work(conn);
1953 }
1954
1955 /*
1956  * We want to make sure a ping is in flight. It has timed out.
1957  * And we are not busy processing a pdu that is making
1958  * progress but got started before the ping and is taking a while
1959  * to complete so the ping is just stuck behind it in a queue.
1960  */
1961 static int iscsi_has_ping_timed_out(struct iscsi_conn *conn)
1962 {
1963         if (conn->ping_task &&
1964             time_before_eq(conn->last_recv + (conn->recv_timeout * HZ) +
1965                            (conn->ping_timeout * HZ), jiffies))
1966                 return 1;
1967         else
1968                 return 0;
1969 }
1970
1971 static enum blk_eh_timer_return iscsi_eh_cmd_timed_out(struct scsi_cmnd *sc)
1972 {
1973         enum blk_eh_timer_return rc = BLK_EH_NOT_HANDLED;
1974         struct iscsi_task *task = NULL, *running_task;
1975         struct iscsi_cls_session *cls_session;
1976         struct iscsi_session *session;
1977         struct iscsi_conn *conn;
1978         int i;
1979
1980         cls_session = starget_to_session(scsi_target(sc->device));
1981         session = cls_session->dd_data;
1982
1983         ISCSI_DBG_EH(session, "scsi cmd %p timedout\n", sc);
1984
1985         spin_lock_bh(&session->frwd_lock);
1986         task = (struct iscsi_task *)sc->SCp.ptr;
1987         if (!task) {
1988                 /*
1989                  * Raced with completion. Blk layer has taken ownership
1990                  * so let timeout code complete it now.
1991                  */
1992                 rc = BLK_EH_HANDLED;
1993                 goto done;
1994         }
1995
1996         if (session->state != ISCSI_STATE_LOGGED_IN) {
1997                 /*
1998                  * During shutdown, if session is prematurely disconnected,
1999                  * recovery won't happen and there will be hung cmds. Not
2000                  * handling cmds would trigger EH, also bad in this case.
2001                  * Instead, handle cmd, allow completion to happen and let
2002                  * upper layer to deal with the result.
2003                  */
2004                 if (unlikely(system_state != SYSTEM_RUNNING)) {
2005                         sc->result = DID_NO_CONNECT << 16;
2006                         ISCSI_DBG_EH(session, "sc on shutdown, handled\n");
2007                         rc = BLK_EH_HANDLED;
2008                         goto done;
2009                 }
2010                 /*
2011                  * We are probably in the middle of iscsi recovery so let
2012                  * that complete and handle the error.
2013                  */
2014                 rc = BLK_EH_RESET_TIMER;
2015                 goto done;
2016         }
2017
2018         conn = session->leadconn;
2019         if (!conn) {
2020                 /* In the middle of shuting down */
2021                 rc = BLK_EH_RESET_TIMER;
2022                 goto done;
2023         }
2024
2025         /*
2026          * If we have sent (at least queued to the network layer) a pdu or
2027          * recvd one for the task since the last timeout ask for
2028          * more time. If on the next timeout we have not made progress
2029          * we can check if it is the task or connection when we send the
2030          * nop as a ping.
2031          */
2032         if (time_after(task->last_xfer, task->last_timeout)) {
2033                 ISCSI_DBG_EH(session, "Command making progress. Asking "
2034                              "scsi-ml for more time to complete. "
2035                              "Last data xfer at %lu. Last timeout was at "
2036                              "%lu\n.", task->last_xfer, task->last_timeout);
2037                 task->have_checked_conn = false;
2038                 rc = BLK_EH_RESET_TIMER;
2039                 goto done;
2040         }
2041
2042         if (!conn->recv_timeout && !conn->ping_timeout)
2043                 goto done;
2044         /*
2045          * if the ping timedout then we are in the middle of cleaning up
2046          * and can let the iscsi eh handle it
2047          */
2048         if (iscsi_has_ping_timed_out(conn)) {
2049                 rc = BLK_EH_RESET_TIMER;
2050                 goto done;
2051         }
2052
2053         for (i = 0; i < conn->session->cmds_max; i++) {
2054                 running_task = conn->session->cmds[i];
2055                 if (!running_task->sc || running_task == task ||
2056                      running_task->state != ISCSI_TASK_RUNNING)
2057                         continue;
2058
2059                 /*
2060                  * Only check if cmds started before this one have made
2061                  * progress, or this could never fail
2062                  */
2063                 if (time_after(running_task->sc->jiffies_at_alloc,
2064                                task->sc->jiffies_at_alloc))
2065                         continue;
2066
2067                 if (time_after(running_task->last_xfer, task->last_timeout)) {
2068                         /*
2069                          * This task has not made progress, but a task
2070                          * started before us has transferred data since
2071                          * we started/last-checked. We could be queueing
2072                          * too many tasks or the LU is bad.
2073                          *
2074                          * If the device is bad the cmds ahead of us on
2075                          * other devs will complete, and this loop will
2076                          * eventually fail starting the scsi eh.
2077                          */
2078                         ISCSI_DBG_EH(session, "Command has not made progress "
2079                                      "but commands ahead of it have. "
2080                                      "Asking scsi-ml for more time to "
2081                                      "complete. Our last xfer vs running task "
2082                                      "last xfer %lu/%lu. Last check %lu.\n",
2083                                      task->last_xfer, running_task->last_xfer,
2084                                      task->last_timeout);
2085                         rc = BLK_EH_RESET_TIMER;
2086                         goto done;
2087                 }
2088         }
2089
2090         /* Assumes nop timeout is shorter than scsi cmd timeout */
2091         if (task->have_checked_conn)
2092                 goto done;
2093
2094         /*
2095          * Checking the transport already or nop from a cmd timeout still
2096          * running
2097          */
2098         if (conn->ping_task) {
2099                 task->have_checked_conn = true;
2100                 rc = BLK_EH_RESET_TIMER;
2101                 goto done;
2102         }
2103
2104         /* Make sure there is a transport check done */
2105         iscsi_send_nopout(conn, NULL);
2106         task->have_checked_conn = true;
2107         rc = BLK_EH_RESET_TIMER;
2108
2109 done:
2110         if (task)
2111                 task->last_timeout = jiffies;
2112         spin_unlock_bh(&session->frwd_lock);
2113         ISCSI_DBG_EH(session, "return %s\n", rc == BLK_EH_RESET_TIMER ?
2114                      "timer reset" : "shutdown or nh");
2115         return rc;
2116 }
2117
2118 static void iscsi_check_transport_timeouts(unsigned long data)
2119 {
2120         struct iscsi_conn *conn = (struct iscsi_conn *)data;
2121         struct iscsi_session *session = conn->session;
2122         unsigned long recv_timeout, next_timeout = 0, last_recv;
2123
2124         spin_lock(&session->frwd_lock);
2125         if (session->state != ISCSI_STATE_LOGGED_IN)
2126                 goto done;
2127
2128         recv_timeout = conn->recv_timeout;
2129         if (!recv_timeout)
2130                 goto done;
2131
2132         recv_timeout *= HZ;
2133         last_recv = conn->last_recv;
2134
2135         if (iscsi_has_ping_timed_out(conn)) {
2136                 iscsi_conn_printk(KERN_ERR, conn, "ping timeout of %d secs "
2137                                   "expired, recv timeout %d, last rx %lu, "
2138                                   "last ping %lu, now %lu\n",
2139                                   conn->ping_timeout, conn->recv_timeout,
2140                                   last_recv, conn->last_ping, jiffies);
2141                 spin_unlock(&session->frwd_lock);
2142                 iscsi_conn_failure(conn, ISCSI_ERR_NOP_TIMEDOUT);
2143                 return;
2144         }
2145
2146         if (time_before_eq(last_recv + recv_timeout, jiffies)) {
2147                 /* send a ping to try to provoke some traffic */
2148                 ISCSI_DBG_CONN(conn, "Sending nopout as ping\n");
2149                 if (iscsi_send_nopout(conn, NULL))
2150                         next_timeout = jiffies + (1 * HZ);
2151                 else
2152                         next_timeout = conn->last_ping + (conn->ping_timeout * HZ);
2153         } else
2154                 next_timeout = last_recv + recv_timeout;
2155
2156         ISCSI_DBG_CONN(conn, "Setting next tmo %lu\n", next_timeout);
2157         mod_timer(&conn->transport_timer, next_timeout);
2158 done:
2159         spin_unlock(&session->frwd_lock);
2160 }
2161
2162 static void iscsi_prep_abort_task_pdu(struct iscsi_task *task,
2163                                       struct iscsi_tm *hdr)
2164 {
2165         memset(hdr, 0, sizeof(*hdr));
2166         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2167         hdr->flags = ISCSI_TM_FUNC_ABORT_TASK & ISCSI_FLAG_TM_FUNC_MASK;
2168         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2169         hdr->lun = task->lun;
2170         hdr->rtt = task->hdr_itt;
2171         hdr->refcmdsn = task->cmdsn;
2172 }
2173
2174 int iscsi_eh_abort(struct scsi_cmnd *sc)
2175 {
2176         struct iscsi_cls_session *cls_session;
2177         struct iscsi_session *session;
2178         struct iscsi_conn *conn;
2179         struct iscsi_task *task;
2180         struct iscsi_tm *hdr;
2181         int rc, age;
2182
2183         cls_session = starget_to_session(scsi_target(sc->device));
2184         session = cls_session->dd_data;
2185
2186         ISCSI_DBG_EH(session, "aborting sc %p\n", sc);
2187
2188         mutex_lock(&session->eh_mutex);
2189         spin_lock_bh(&session->frwd_lock);
2190         /*
2191          * if session was ISCSI_STATE_IN_RECOVERY then we may not have
2192          * got the command.
2193          */
2194         if (!sc->SCp.ptr) {
2195                 ISCSI_DBG_EH(session, "sc never reached iscsi layer or "
2196                                       "it completed.\n");
2197                 spin_unlock_bh(&session->frwd_lock);
2198                 mutex_unlock(&session->eh_mutex);
2199                 return SUCCESS;
2200         }
2201
2202         /*
2203          * If we are not logged in or we have started a new session
2204          * then let the host reset code handle this
2205          */
2206         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN ||
2207             sc->SCp.phase != session->age) {
2208                 spin_unlock_bh(&session->frwd_lock);
2209                 mutex_unlock(&session->eh_mutex);
2210                 ISCSI_DBG_EH(session, "failing abort due to dropped "
2211                                   "session.\n");
2212                 return FAILED;
2213         }
2214
2215         conn = session->leadconn;
2216         conn->eh_abort_cnt++;
2217         age = session->age;
2218
2219         task = (struct iscsi_task *)sc->SCp.ptr;
2220         ISCSI_DBG_EH(session, "aborting [sc %p itt 0x%x]\n",
2221                      sc, task->itt);
2222
2223         /* task completed before time out */
2224         if (!task->sc) {
2225                 ISCSI_DBG_EH(session, "sc completed while abort in progress\n");
2226                 goto success;
2227         }
2228
2229         if (task->state == ISCSI_TASK_PENDING) {
2230                 fail_scsi_task(task, DID_ABORT);
2231                 goto success;
2232         }
2233
2234         /* only have one tmf outstanding at a time */
2235         if (conn->tmf_state != TMF_INITIAL)
2236                 goto failed;
2237         conn->tmf_state = TMF_QUEUED;
2238
2239         hdr = &conn->tmhdr;
2240         iscsi_prep_abort_task_pdu(task, hdr);
2241
2242         if (iscsi_exec_task_mgmt_fn(conn, hdr, age, session->abort_timeout)) {
2243                 rc = FAILED;
2244                 goto failed;
2245         }
2246
2247         switch (conn->tmf_state) {
2248         case TMF_SUCCESS:
2249                 spin_unlock_bh(&session->frwd_lock);
2250                 /*
2251                  * stop tx side incase the target had sent a abort rsp but
2252                  * the initiator was still writing out data.
2253                  */
2254                 iscsi_suspend_tx(conn);
2255                 /*
2256                  * we do not stop the recv side because targets have been
2257                  * good and have never sent us a successful tmf response
2258                  * then sent more data for the cmd.
2259                  */
2260                 spin_lock_bh(&session->frwd_lock);
2261                 fail_scsi_task(task, DID_ABORT);
2262                 conn->tmf_state = TMF_INITIAL;
2263                 memset(hdr, 0, sizeof(*hdr));
2264                 spin_unlock_bh(&session->frwd_lock);
2265                 iscsi_start_tx(conn);
2266                 goto success_unlocked;
2267         case TMF_TIMEDOUT:
2268                 spin_unlock_bh(&session->frwd_lock);
2269                 iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2270                 goto failed_unlocked;
2271         case TMF_NOT_FOUND:
2272                 if (!sc->SCp.ptr) {
2273                         conn->tmf_state = TMF_INITIAL;
2274                         memset(hdr, 0, sizeof(*hdr));
2275                         /* task completed before tmf abort response */
2276                         ISCSI_DBG_EH(session, "sc completed while abort in "
2277                                               "progress\n");
2278                         goto success;
2279                 }
2280                 /* fall through */
2281         default:
2282                 conn->tmf_state = TMF_INITIAL;
2283                 goto failed;
2284         }
2285
2286 success:
2287         spin_unlock_bh(&session->frwd_lock);
2288 success_unlocked:
2289         ISCSI_DBG_EH(session, "abort success [sc %p itt 0x%x]\n",
2290                      sc, task->itt);
2291         mutex_unlock(&session->eh_mutex);
2292         return SUCCESS;
2293
2294 failed:
2295         spin_unlock_bh(&session->frwd_lock);
2296 failed_unlocked:
2297         ISCSI_DBG_EH(session, "abort failed [sc %p itt 0x%x]\n", sc,
2298                      task ? task->itt : 0);
2299         mutex_unlock(&session->eh_mutex);
2300         return FAILED;
2301 }
2302 EXPORT_SYMBOL_GPL(iscsi_eh_abort);
2303
2304 static void iscsi_prep_lun_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
2305 {
2306         memset(hdr, 0, sizeof(*hdr));
2307         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2308         hdr->flags = ISCSI_TM_FUNC_LOGICAL_UNIT_RESET & ISCSI_FLAG_TM_FUNC_MASK;
2309         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2310         int_to_scsilun(sc->device->lun, &hdr->lun);
2311         hdr->rtt = RESERVED_ITT;
2312 }
2313
2314 int iscsi_eh_device_reset(struct scsi_cmnd *sc)
2315 {
2316         struct iscsi_cls_session *cls_session;
2317         struct iscsi_session *session;
2318         struct iscsi_conn *conn;
2319         struct iscsi_tm *hdr;
2320         int rc = FAILED;
2321
2322         cls_session = starget_to_session(scsi_target(sc->device));
2323         session = cls_session->dd_data;
2324
2325         ISCSI_DBG_EH(session, "LU Reset [sc %p lun %llu]\n", sc,
2326                      sc->device->lun);
2327
2328         mutex_lock(&session->eh_mutex);
2329         spin_lock_bh(&session->frwd_lock);
2330         /*
2331          * Just check if we are not logged in. We cannot check for
2332          * the phase because the reset could come from a ioctl.
2333          */
2334         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
2335                 goto unlock;
2336         conn = session->leadconn;
2337
2338         /* only have one tmf outstanding at a time */
2339         if (conn->tmf_state != TMF_INITIAL)
2340                 goto unlock;
2341         conn->tmf_state = TMF_QUEUED;
2342
2343         hdr = &conn->tmhdr;
2344         iscsi_prep_lun_reset_pdu(sc, hdr);
2345
2346         if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
2347                                     session->lu_reset_timeout)) {
2348                 rc = FAILED;
2349                 goto unlock;
2350         }
2351
2352         switch (conn->tmf_state) {
2353         case TMF_SUCCESS:
2354                 break;
2355         case TMF_TIMEDOUT:
2356                 spin_unlock_bh(&session->frwd_lock);
2357                 iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2358                 goto done;
2359         default:
2360                 conn->tmf_state = TMF_INITIAL;
2361                 goto unlock;
2362         }
2363
2364         rc = SUCCESS;
2365         spin_unlock_bh(&session->frwd_lock);
2366
2367         iscsi_suspend_tx(conn);
2368
2369         spin_lock_bh(&session->frwd_lock);
2370         memset(hdr, 0, sizeof(*hdr));
2371         fail_scsi_tasks(conn, sc->device->lun, DID_ERROR);
2372         conn->tmf_state = TMF_INITIAL;
2373         spin_unlock_bh(&session->frwd_lock);
2374
2375         iscsi_start_tx(conn);
2376         goto done;
2377
2378 unlock:
2379         spin_unlock_bh(&session->frwd_lock);
2380 done:
2381         ISCSI_DBG_EH(session, "dev reset result = %s\n",
2382                      rc == SUCCESS ? "SUCCESS" : "FAILED");
2383         mutex_unlock(&session->eh_mutex);
2384         return rc;
2385 }
2386 EXPORT_SYMBOL_GPL(iscsi_eh_device_reset);
2387
2388 void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
2389 {
2390         struct iscsi_session *session = cls_session->dd_data;
2391
2392         spin_lock_bh(&session->frwd_lock);
2393         if (session->state != ISCSI_STATE_LOGGED_IN) {
2394                 session->state = ISCSI_STATE_RECOVERY_FAILED;
2395                 if (session->leadconn)
2396                         wake_up(&session->leadconn->ehwait);
2397         }
2398         spin_unlock_bh(&session->frwd_lock);
2399 }
2400 EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
2401
2402 /**
2403  * iscsi_eh_session_reset - drop session and attempt relogin
2404  * @sc: scsi command
2405  *
2406  * This function will wait for a relogin, session termination from
2407  * userspace, or a recovery/replacement timeout.
2408  */
2409 int iscsi_eh_session_reset(struct scsi_cmnd *sc)
2410 {
2411         struct iscsi_cls_session *cls_session;
2412         struct iscsi_session *session;
2413         struct iscsi_conn *conn;
2414
2415         cls_session = starget_to_session(scsi_target(sc->device));
2416         session = cls_session->dd_data;
2417         conn = session->leadconn;
2418
2419         mutex_lock(&session->eh_mutex);
2420         spin_lock_bh(&session->frwd_lock);
2421         if (session->state == ISCSI_STATE_TERMINATE) {
2422 failed:
2423                 ISCSI_DBG_EH(session,
2424                              "failing session reset: Could not log back into "
2425                              "%s [age %d]\n", session->targetname,
2426                              session->age);
2427                 spin_unlock_bh(&session->frwd_lock);
2428                 mutex_unlock(&session->eh_mutex);
2429                 return FAILED;
2430         }
2431
2432         spin_unlock_bh(&session->frwd_lock);
2433         mutex_unlock(&session->eh_mutex);
2434         /*
2435          * we drop the lock here but the leadconn cannot be destoyed while
2436          * we are in the scsi eh
2437          */
2438         iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2439
2440         ISCSI_DBG_EH(session, "wait for relogin\n");
2441         wait_event_interruptible(conn->ehwait,
2442                                  session->state == ISCSI_STATE_TERMINATE ||
2443                                  session->state == ISCSI_STATE_LOGGED_IN ||
2444                                  session->state == ISCSI_STATE_RECOVERY_FAILED);
2445         if (signal_pending(current))
2446                 flush_signals(current);
2447
2448         mutex_lock(&session->eh_mutex);
2449         spin_lock_bh(&session->frwd_lock);
2450         if (session->state == ISCSI_STATE_LOGGED_IN) {
2451                 ISCSI_DBG_EH(session,
2452                              "session reset succeeded for %s,%s\n",
2453                              session->targetname, conn->persistent_address);
2454         } else
2455                 goto failed;
2456         spin_unlock_bh(&session->frwd_lock);
2457         mutex_unlock(&session->eh_mutex);
2458         return SUCCESS;
2459 }
2460 EXPORT_SYMBOL_GPL(iscsi_eh_session_reset);
2461
2462 static void iscsi_prep_tgt_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
2463 {
2464         memset(hdr, 0, sizeof(*hdr));
2465         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2466         hdr->flags = ISCSI_TM_FUNC_TARGET_WARM_RESET & ISCSI_FLAG_TM_FUNC_MASK;
2467         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2468         hdr->rtt = RESERVED_ITT;
2469 }
2470
2471 /**
2472  * iscsi_eh_target_reset - reset target
2473  * @sc: scsi command
2474  *
2475  * This will attempt to send a warm target reset.
2476  */
2477 int iscsi_eh_target_reset(struct scsi_cmnd *sc)
2478 {
2479         struct iscsi_cls_session *cls_session;
2480         struct iscsi_session *session;
2481         struct iscsi_conn *conn;
2482         struct iscsi_tm *hdr;
2483         int rc = FAILED;
2484
2485         cls_session = starget_to_session(scsi_target(sc->device));
2486         session = cls_session->dd_data;
2487
2488         ISCSI_DBG_EH(session, "tgt Reset [sc %p tgt %s]\n", sc,
2489                      session->targetname);
2490
2491         mutex_lock(&session->eh_mutex);
2492         spin_lock_bh(&session->frwd_lock);
2493         /*
2494          * Just check if we are not logged in. We cannot check for
2495          * the phase because the reset could come from a ioctl.
2496          */
2497         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
2498                 goto unlock;
2499         conn = session->leadconn;
2500
2501         /* only have one tmf outstanding at a time */
2502         if (conn->tmf_state != TMF_INITIAL)
2503                 goto unlock;
2504         conn->tmf_state = TMF_QUEUED;
2505
2506         hdr = &conn->tmhdr;
2507         iscsi_prep_tgt_reset_pdu(sc, hdr);
2508
2509         if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
2510                                     session->tgt_reset_timeout)) {
2511                 rc = FAILED;
2512                 goto unlock;
2513         }
2514
2515         switch (conn->tmf_state) {
2516         case TMF_SUCCESS:
2517                 break;
2518         case TMF_TIMEDOUT:
2519                 spin_unlock_bh(&session->frwd_lock);
2520                 iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2521                 goto done;
2522         default:
2523                 conn->tmf_state = TMF_INITIAL;
2524                 goto unlock;
2525         }
2526
2527         rc = SUCCESS;
2528         spin_unlock_bh(&session->frwd_lock);
2529
2530         iscsi_suspend_tx(conn);
2531
2532         spin_lock_bh(&session->frwd_lock);
2533         memset(hdr, 0, sizeof(*hdr));
2534         fail_scsi_tasks(conn, -1, DID_ERROR);
2535         conn->tmf_state = TMF_INITIAL;
2536         spin_unlock_bh(&session->frwd_lock);
2537
2538         iscsi_start_tx(conn);
2539         goto done;
2540
2541 unlock:
2542         spin_unlock_bh(&session->frwd_lock);
2543 done:
2544         ISCSI_DBG_EH(session, "tgt %s reset result = %s\n", session->targetname,
2545                      rc == SUCCESS ? "SUCCESS" : "FAILED");
2546         mutex_unlock(&session->eh_mutex);
2547         return rc;
2548 }
2549 EXPORT_SYMBOL_GPL(iscsi_eh_target_reset);
2550
2551 /**
2552  * iscsi_eh_recover_target - reset target and possibly the session
2553  * @sc: scsi command
2554  *
2555  * This will attempt to send a warm target reset. If that fails,
2556  * we will escalate to ERL0 session recovery.
2557  */
2558 int iscsi_eh_recover_target(struct scsi_cmnd *sc)
2559 {
2560         int rc;
2561
2562         rc = iscsi_eh_target_reset(sc);
2563         if (rc == FAILED)
2564                 rc = iscsi_eh_session_reset(sc);
2565         return rc;
2566 }
2567 EXPORT_SYMBOL_GPL(iscsi_eh_recover_target);
2568
2569 /*
2570  * Pre-allocate a pool of @max items of @item_size. By default, the pool
2571  * should be accessed via kfifo_{get,put} on q->queue.
2572  * Optionally, the caller can obtain the array of object pointers
2573  * by passing in a non-NULL @items pointer
2574  */
2575 int
2576 iscsi_pool_init(struct iscsi_pool *q, int max, void ***items, int item_size)
2577 {
2578         int i, num_arrays = 1;
2579
2580         memset(q, 0, sizeof(*q));
2581
2582         q->max = max;
2583
2584         /* If the user passed an items pointer, he wants a copy of
2585          * the array. */
2586         if (items)
2587                 num_arrays++;
2588         q->pool = kzalloc(num_arrays * max * sizeof(void*), GFP_KERNEL);
2589         if (q->pool == NULL)
2590                 return -ENOMEM;
2591
2592         kfifo_init(&q->queue, (void*)q->pool, max * sizeof(void*));
2593
2594         for (i = 0; i < max; i++) {
2595                 q->pool[i] = kzalloc(item_size, GFP_KERNEL);
2596                 if (q->pool[i] == NULL) {
2597                         q->max = i;
2598                         goto enomem;
2599                 }
2600                 kfifo_in(&q->queue, (void*)&q->pool[i], sizeof(void*));
2601         }
2602
2603         if (items) {
2604                 *items = q->pool + max;
2605                 memcpy(*items, q->pool, max * sizeof(void *));
2606         }
2607
2608         return 0;
2609
2610 enomem:
2611         iscsi_pool_free(q);
2612         return -ENOMEM;
2613 }
2614 EXPORT_SYMBOL_GPL(iscsi_pool_init);
2615
2616 void iscsi_pool_free(struct iscsi_pool *q)
2617 {
2618         int i;
2619
2620         for (i = 0; i < q->max; i++)
2621                 kfree(q->pool[i]);
2622         kfree(q->pool);
2623 }
2624 EXPORT_SYMBOL_GPL(iscsi_pool_free);
2625
2626 /**
2627  * iscsi_host_add - add host to system
2628  * @shost: scsi host
2629  * @pdev: parent device
2630  *
2631  * This should be called by partial offload and software iscsi drivers
2632  * to add a host to the system.
2633  */
2634 int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev)
2635 {
2636         if (!shost->can_queue)
2637                 shost->can_queue = ISCSI_DEF_XMIT_CMDS_MAX;
2638
2639         if (!shost->cmd_per_lun)
2640                 shost->cmd_per_lun = ISCSI_DEF_CMD_PER_LUN;
2641
2642         if (!shost->transportt->eh_timed_out)
2643                 shost->transportt->eh_timed_out = iscsi_eh_cmd_timed_out;
2644         return scsi_add_host(shost, pdev);
2645 }
2646 EXPORT_SYMBOL_GPL(iscsi_host_add);
2647
2648 /**
2649  * iscsi_host_alloc - allocate a host and driver data
2650  * @sht: scsi host template
2651  * @dd_data_size: driver host data size
2652  * @xmit_can_sleep: bool indicating if LLD will queue IO from a work queue
2653  *
2654  * This should be called by partial offload and software iscsi drivers.
2655  * To access the driver specific memory use the iscsi_host_priv() macro.
2656  */
2657 struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
2658                                    int dd_data_size, bool xmit_can_sleep)
2659 {
2660         struct Scsi_Host *shost;
2661         struct iscsi_host *ihost;
2662
2663         shost = scsi_host_alloc(sht, sizeof(struct iscsi_host) + dd_data_size);
2664         if (!shost)
2665                 return NULL;
2666         ihost = shost_priv(shost);
2667
2668         if (xmit_can_sleep) {
2669                 snprintf(ihost->workq_name, sizeof(ihost->workq_name),
2670                         "iscsi_q_%d", shost->host_no);
2671                 ihost->workq = create_singlethread_workqueue(ihost->workq_name);
2672                 if (!ihost->workq)
2673                         goto free_host;
2674         }
2675
2676         spin_lock_init(&ihost->lock);
2677         ihost->state = ISCSI_HOST_SETUP;
2678         ihost->num_sessions = 0;
2679         init_waitqueue_head(&ihost->session_removal_wq);
2680         return shost;
2681
2682 free_host:
2683         scsi_host_put(shost);
2684         return NULL;
2685 }
2686 EXPORT_SYMBOL_GPL(iscsi_host_alloc);
2687
2688 static void iscsi_notify_host_removed(struct iscsi_cls_session *cls_session)
2689 {
2690         iscsi_session_failure(cls_session->dd_data, ISCSI_ERR_INVALID_HOST);
2691 }
2692
2693 /**
2694  * iscsi_host_remove - remove host and sessions
2695  * @shost: scsi host
2696  *
2697  * If there are any sessions left, this will initiate the removal and wait
2698  * for the completion.
2699  */
2700 void iscsi_host_remove(struct Scsi_Host *shost)
2701 {
2702         struct iscsi_host *ihost = shost_priv(shost);
2703         unsigned long flags;
2704
2705         spin_lock_irqsave(&ihost->lock, flags);
2706         ihost->state = ISCSI_HOST_REMOVED;
2707         spin_unlock_irqrestore(&ihost->lock, flags);
2708
2709         iscsi_host_for_each_session(shost, iscsi_notify_host_removed);
2710         wait_event_interruptible(ihost->session_removal_wq,
2711                                  ihost->num_sessions == 0);
2712         if (signal_pending(current))
2713                 flush_signals(current);
2714
2715         scsi_remove_host(shost);
2716         if (ihost->workq)
2717                 destroy_workqueue(ihost->workq);
2718 }
2719 EXPORT_SYMBOL_GPL(iscsi_host_remove);
2720
2721 void iscsi_host_free(struct Scsi_Host *shost)
2722 {
2723         struct iscsi_host *ihost = shost_priv(shost);
2724
2725         kfree(ihost->netdev);
2726         kfree(ihost->hwaddress);
2727         kfree(ihost->initiatorname);
2728         scsi_host_put(shost);
2729 }
2730 EXPORT_SYMBOL_GPL(iscsi_host_free);
2731
2732 static void iscsi_host_dec_session_cnt(struct Scsi_Host *shost)
2733 {
2734         struct iscsi_host *ihost = shost_priv(shost);
2735         unsigned long flags;
2736
2737         shost = scsi_host_get(shost);
2738         if (!shost) {
2739                 printk(KERN_ERR "Invalid state. Cannot notify host removal "
2740                       "of session teardown event because host already "
2741                       "removed.\n");
2742                 return;
2743         }
2744
2745         spin_lock_irqsave(&ihost->lock, flags);
2746         ihost->num_sessions--;
2747         if (ihost->num_sessions == 0)
2748                 wake_up(&ihost->session_removal_wq);
2749         spin_unlock_irqrestore(&ihost->lock, flags);
2750         scsi_host_put(shost);
2751 }
2752
2753 /**
2754  * iscsi_session_setup - create iscsi cls session and host and session
2755  * @iscsit: iscsi transport template
2756  * @shost: scsi host
2757  * @cmds_max: session can queue
2758  * @cmd_task_size: LLD task private data size
2759  * @initial_cmdsn: initial CmdSN
2760  *
2761  * This can be used by software iscsi_transports that allocate
2762  * a session per scsi host.
2763  *
2764  * Callers should set cmds_max to the largest total numer (mgmt + scsi) of
2765  * tasks they support. The iscsi layer reserves ISCSI_MGMT_CMDS_MAX tasks
2766  * for nop handling and login/logout requests.
2767  */
2768 struct iscsi_cls_session *
2769 iscsi_session_setup(struct iscsi_transport *iscsit, struct Scsi_Host *shost,
2770                     uint16_t cmds_max, int dd_size, int cmd_task_size,
2771                     uint32_t initial_cmdsn, unsigned int id)
2772 {
2773         struct iscsi_host *ihost = shost_priv(shost);
2774         struct iscsi_session *session;
2775         struct iscsi_cls_session *cls_session;
2776         int cmd_i, scsi_cmds, total_cmds = cmds_max;
2777         unsigned long flags;
2778
2779         spin_lock_irqsave(&ihost->lock, flags);
2780         if (ihost->state == ISCSI_HOST_REMOVED) {
2781                 spin_unlock_irqrestore(&ihost->lock, flags);
2782                 return NULL;
2783         }
2784         ihost->num_sessions++;
2785         spin_unlock_irqrestore(&ihost->lock, flags);
2786
2787         if (!total_cmds)
2788                 total_cmds = ISCSI_DEF_XMIT_CMDS_MAX;
2789         /*
2790          * The iscsi layer needs some tasks for nop handling and tmfs,
2791          * so the cmds_max must at least be greater than ISCSI_MGMT_CMDS_MAX
2792          * + 1 command for scsi IO.
2793          */
2794         if (total_cmds < ISCSI_TOTAL_CMDS_MIN) {
2795                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2796                        "must be a power of two that is at least %d.\n",
2797                        total_cmds, ISCSI_TOTAL_CMDS_MIN);
2798                 goto dec_session_count;
2799         }
2800
2801         if (total_cmds > ISCSI_TOTAL_CMDS_MAX) {
2802                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2803                        "must be a power of 2 less than or equal to %d.\n",
2804                        cmds_max, ISCSI_TOTAL_CMDS_MAX);
2805                 total_cmds = ISCSI_TOTAL_CMDS_MAX;
2806         }
2807
2808         if (!is_power_of_2(total_cmds)) {
2809                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2810                        "must be a power of 2.\n", total_cmds);
2811                 total_cmds = rounddown_pow_of_two(total_cmds);
2812                 if (total_cmds < ISCSI_TOTAL_CMDS_MIN)
2813                         return NULL;
2814                 printk(KERN_INFO "iscsi: Rounding can_queue to %d.\n",
2815                        total_cmds);
2816         }
2817         scsi_cmds = total_cmds - ISCSI_MGMT_CMDS_MAX;
2818
2819         cls_session = iscsi_alloc_session(shost, iscsit,
2820                                           sizeof(struct iscsi_session) +
2821                                           dd_size);
2822         if (!cls_session)
2823                 goto dec_session_count;
2824         session = cls_session->dd_data;
2825         session->cls_session = cls_session;
2826         session->host = shost;
2827         session->state = ISCSI_STATE_FREE;
2828         session->fast_abort = 1;
2829         session->tgt_reset_timeout = 30;
2830         session->lu_reset_timeout = 15;
2831         session->abort_timeout = 10;
2832         session->scsi_cmds_max = scsi_cmds;
2833         session->cmds_max = total_cmds;
2834         session->queued_cmdsn = session->cmdsn = initial_cmdsn;
2835         session->exp_cmdsn = initial_cmdsn + 1;
2836         session->max_cmdsn = initial_cmdsn + 1;
2837         session->max_r2t = 1;
2838         session->tt = iscsit;
2839         session->dd_data = cls_session->dd_data + sizeof(*session);
2840
2841         mutex_init(&session->eh_mutex);
2842         spin_lock_init(&session->frwd_lock);
2843         spin_lock_init(&session->back_lock);
2844
2845         /* initialize SCSI PDU commands pool */
2846         if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
2847                             (void***)&session->cmds,
2848                             cmd_task_size + sizeof(struct iscsi_task)))
2849                 goto cmdpool_alloc_fail;
2850
2851         /* pre-format cmds pool with ITT */
2852         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
2853                 struct iscsi_task *task = session->cmds[cmd_i];
2854
2855                 if (cmd_task_size)
2856                         task->dd_data = &task[1];
2857                 task->itt = cmd_i;
2858                 task->state = ISCSI_TASK_FREE;
2859                 INIT_LIST_HEAD(&task->running);
2860         }
2861
2862         if (!try_module_get(iscsit->owner))
2863                 goto module_get_fail;
2864
2865         if (iscsi_add_session(cls_session, id))
2866                 goto cls_session_fail;
2867
2868         return cls_session;
2869
2870 cls_session_fail:
2871         module_put(iscsit->owner);
2872 module_get_fail:
2873         iscsi_pool_free(&session->cmdpool);
2874 cmdpool_alloc_fail:
2875         iscsi_free_session(cls_session);
2876 dec_session_count:
2877         iscsi_host_dec_session_cnt(shost);
2878         return NULL;
2879 }
2880 EXPORT_SYMBOL_GPL(iscsi_session_setup);
2881
2882 /**
2883  * iscsi_session_teardown - destroy session, host, and cls_session
2884  * @cls_session: iscsi session
2885  *
2886  * The driver must have called iscsi_remove_session before
2887  * calling this.
2888  */
2889 void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
2890 {
2891         struct iscsi_session *session = cls_session->dd_data;
2892         struct module *owner = cls_session->transport->owner;
2893         struct Scsi_Host *shost = session->host;
2894
2895         iscsi_pool_free(&session->cmdpool);
2896
2897         kfree(session->password);
2898         kfree(session->password_in);
2899         kfree(session->username);
2900         kfree(session->username_in);
2901         kfree(session->targetname);
2902         kfree(session->targetalias);
2903         kfree(session->initiatorname);
2904         kfree(session->boot_root);
2905         kfree(session->boot_nic);
2906         kfree(session->boot_target);
2907         kfree(session->ifacename);
2908         kfree(session->portal_type);
2909         kfree(session->discovery_parent_type);
2910
2911         iscsi_destroy_session(cls_session);
2912         iscsi_host_dec_session_cnt(shost);
2913         module_put(owner);
2914 }
2915 EXPORT_SYMBOL_GPL(iscsi_session_teardown);
2916
2917 /**
2918  * iscsi_conn_setup - create iscsi_cls_conn and iscsi_conn
2919  * @cls_session: iscsi_cls_session
2920  * @dd_size: private driver data size
2921  * @conn_idx: cid
2922  */
2923 struct iscsi_cls_conn *
2924 iscsi_conn_setup(struct iscsi_cls_session *cls_session, int dd_size,
2925                  uint32_t conn_idx)
2926 {
2927         struct iscsi_session *session = cls_session->dd_data;
2928         struct iscsi_conn *conn;
2929         struct iscsi_cls_conn *cls_conn;
2930         char *data;
2931
2932         cls_conn = iscsi_create_conn(cls_session, sizeof(*conn) + dd_size,
2933                                      conn_idx);
2934         if (!cls_conn)
2935                 return NULL;
2936         conn = cls_conn->dd_data;
2937         memset(conn, 0, sizeof(*conn) + dd_size);
2938
2939         conn->dd_data = cls_conn->dd_data + sizeof(*conn);
2940         conn->session = session;
2941         conn->cls_conn = cls_conn;
2942         conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
2943         conn->id = conn_idx;
2944         conn->exp_statsn = 0;
2945         conn->tmf_state = TMF_INITIAL;
2946
2947         init_timer(&conn->transport_timer);
2948         conn->transport_timer.data = (unsigned long)conn;
2949         conn->transport_timer.function = iscsi_check_transport_timeouts;
2950
2951         INIT_LIST_HEAD(&conn->mgmtqueue);
2952         INIT_LIST_HEAD(&conn->cmdqueue);
2953         INIT_LIST_HEAD(&conn->requeue);
2954         spin_lock_init(&conn->taskqueuelock);
2955         INIT_WORK(&conn->xmitwork, iscsi_xmitworker);
2956
2957         /* allocate login_task used for the login/text sequences */
2958         spin_lock_bh(&session->frwd_lock);
2959         if (!kfifo_out(&session->cmdpool.queue,
2960                          (void*)&conn->login_task,
2961                          sizeof(void*))) {
2962                 spin_unlock_bh(&session->frwd_lock);
2963                 goto login_task_alloc_fail;
2964         }
2965         spin_unlock_bh(&session->frwd_lock);
2966
2967         data = (char *) __get_free_pages(GFP_KERNEL,
2968                                          get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
2969         if (!data)
2970                 goto login_task_data_alloc_fail;
2971         conn->login_task->data = conn->data = data;
2972
2973         init_timer(&conn->tmf_timer);
2974         init_waitqueue_head(&conn->ehwait);
2975
2976         return cls_conn;
2977
2978 login_task_data_alloc_fail:
2979         kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
2980                     sizeof(void*));
2981 login_task_alloc_fail:
2982         iscsi_destroy_conn(cls_conn);
2983         return NULL;
2984 }
2985 EXPORT_SYMBOL_GPL(iscsi_conn_setup);
2986
2987 /**
2988  * iscsi_conn_teardown - teardown iscsi connection
2989  * cls_conn: iscsi class connection
2990  *
2991  * TODO: we may need to make this into a two step process
2992  * like scsi-mls remove + put host
2993  */
2994 void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
2995 {
2996         struct iscsi_conn *conn = cls_conn->dd_data;
2997         struct iscsi_session *session = conn->session;
2998
2999         del_timer_sync(&conn->transport_timer);
3000
3001         mutex_lock(&session->eh_mutex);
3002         spin_lock_bh(&session->frwd_lock);
3003         conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
3004         if (session->leadconn == conn) {
3005                 /*
3006                  * leading connection? then give up on recovery.
3007                  */
3008                 session->state = ISCSI_STATE_TERMINATE;
3009                 wake_up(&conn->ehwait);
3010         }
3011         spin_unlock_bh(&session->frwd_lock);
3012
3013         /* flush queued up work because we free the connection below */
3014         iscsi_suspend_tx(conn);
3015
3016         spin_lock_bh(&session->frwd_lock);
3017         free_pages((unsigned long) conn->data,
3018                    get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
3019         kfree(conn->persistent_address);
3020         kfree(conn->local_ipaddr);
3021         /* regular RX path uses back_lock */
3022         spin_lock_bh(&session->back_lock);
3023         kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
3024                     sizeof(void*));
3025         spin_unlock_bh(&session->back_lock);
3026         if (session->leadconn == conn)
3027                 session->leadconn = NULL;
3028         spin_unlock_bh(&session->frwd_lock);
3029         mutex_unlock(&session->eh_mutex);
3030
3031         iscsi_destroy_conn(cls_conn);
3032 }
3033 EXPORT_SYMBOL_GPL(iscsi_conn_teardown);
3034
3035 int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
3036 {
3037         struct iscsi_conn *conn = cls_conn->dd_data;
3038         struct iscsi_session *session = conn->session;
3039
3040         if (!session) {
3041                 iscsi_conn_printk(KERN_ERR, conn,
3042                                   "can't start unbound connection\n");
3043                 return -EPERM;
3044         }
3045
3046         if ((session->imm_data_en || !session->initial_r2t_en) &&
3047              session->first_burst > session->max_burst) {
3048                 iscsi_conn_printk(KERN_INFO, conn, "invalid burst lengths: "
3049                                   "first_burst %d max_burst %d\n",
3050                                   session->first_burst, session->max_burst);
3051                 return -EINVAL;
3052         }
3053
3054         if (conn->ping_timeout && !conn->recv_timeout) {
3055                 iscsi_conn_printk(KERN_ERR, conn, "invalid recv timeout of "
3056                                   "zero. Using 5 seconds\n.");
3057                 conn->recv_timeout = 5;
3058         }
3059
3060         if (conn->recv_timeout && !conn->ping_timeout) {
3061                 iscsi_conn_printk(KERN_ERR, conn, "invalid ping timeout of "
3062                                   "zero. Using 5 seconds.\n");
3063                 conn->ping_timeout = 5;
3064         }
3065
3066         spin_lock_bh(&session->frwd_lock);
3067         conn->c_stage = ISCSI_CONN_STARTED;
3068         session->state = ISCSI_STATE_LOGGED_IN;
3069         session->queued_cmdsn = session->cmdsn;
3070
3071         conn->last_recv = jiffies;
3072         conn->last_ping = jiffies;
3073         if (conn->recv_timeout && conn->ping_timeout)
3074                 mod_timer(&conn->transport_timer,
3075                           jiffies + (conn->recv_timeout * HZ));
3076
3077         switch(conn->stop_stage) {
3078         case STOP_CONN_RECOVER:
3079                 /*
3080                  * unblock eh_abort() if it is blocked. re-try all
3081                  * commands after successful recovery
3082                  */
3083                 conn->stop_stage = 0;
3084                 conn->tmf_state = TMF_INITIAL;
3085                 session->age++;
3086                 if (session->age == 16)
3087                         session->age = 0;
3088                 break;
3089         case STOP_CONN_TERM:
3090                 conn->stop_stage = 0;
3091                 break;
3092         default:
3093                 break;
3094         }
3095         spin_unlock_bh(&session->frwd_lock);
3096
3097         iscsi_unblock_session(session->cls_session);
3098         wake_up(&conn->ehwait);
3099         return 0;
3100 }
3101 EXPORT_SYMBOL_GPL(iscsi_conn_start);
3102
3103 static void
3104 fail_mgmt_tasks(struct iscsi_session *session, struct iscsi_conn *conn)
3105 {
3106         struct iscsi_task *task;
3107         int i, state;
3108
3109         for (i = 0; i < conn->session->cmds_max; i++) {
3110                 task = conn->session->cmds[i];
3111                 if (task->sc)
3112                         continue;
3113
3114                 if (task->state == ISCSI_TASK_FREE)
3115                         continue;
3116
3117                 ISCSI_DBG_SESSION(conn->session,
3118                                   "failing mgmt itt 0x%x state %d\n",
3119                                   task->itt, task->state);
3120                 state = ISCSI_TASK_ABRT_SESS_RECOV;
3121                 if (task->state == ISCSI_TASK_PENDING)
3122                         state = ISCSI_TASK_COMPLETED;
3123                 iscsi_complete_task(task, state);
3124
3125         }
3126 }
3127
3128 static void iscsi_start_session_recovery(struct iscsi_session *session,
3129                                          struct iscsi_conn *conn, int flag)
3130 {
3131         int old_stop_stage;
3132
3133         mutex_lock(&session->eh_mutex);
3134         spin_lock_bh(&session->frwd_lock);
3135         if (conn->stop_stage == STOP_CONN_TERM) {
3136                 spin_unlock_bh(&session->frwd_lock);
3137                 mutex_unlock(&session->eh_mutex);
3138                 return;
3139         }
3140
3141         /*
3142          * When this is called for the in_login state, we only want to clean
3143          * up the login task and connection. We do not need to block and set
3144          * the recovery state again
3145          */
3146         if (flag == STOP_CONN_TERM)
3147                 session->state = ISCSI_STATE_TERMINATE;
3148         else if (conn->stop_stage != STOP_CONN_RECOVER)
3149                 session->state = ISCSI_STATE_IN_RECOVERY;
3150
3151         old_stop_stage = conn->stop_stage;
3152         conn->stop_stage = flag;
3153         spin_unlock_bh(&session->frwd_lock);
3154
3155         del_timer_sync(&conn->transport_timer);
3156         iscsi_suspend_tx(conn);
3157
3158         spin_lock_bh(&session->frwd_lock);
3159         conn->c_stage = ISCSI_CONN_STOPPED;
3160         spin_unlock_bh(&session->frwd_lock);
3161
3162         /*
3163          * for connection level recovery we should not calculate
3164          * header digest. conn->hdr_size used for optimization
3165          * in hdr_extract() and will be re-negotiated at
3166          * set_param() time.
3167          */
3168         if (flag == STOP_CONN_RECOVER) {
3169                 conn->hdrdgst_en = 0;
3170                 conn->datadgst_en = 0;
3171                 if (session->state == ISCSI_STATE_IN_RECOVERY &&
3172                     old_stop_stage != STOP_CONN_RECOVER) {
3173                         ISCSI_DBG_SESSION(session, "blocking session\n");
3174                         iscsi_block_session(session->cls_session);
3175                 }
3176         }
3177
3178         /*
3179          * flush queues.
3180          */
3181         spin_lock_bh(&session->frwd_lock);
3182         fail_scsi_tasks(conn, -1, DID_TRANSPORT_DISRUPTED);
3183         fail_mgmt_tasks(session, conn);
3184         memset(&conn->tmhdr, 0, sizeof(conn->tmhdr));
3185         spin_unlock_bh(&session->frwd_lock);
3186         mutex_unlock(&session->eh_mutex);
3187 }
3188
3189 void iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
3190 {
3191         struct iscsi_conn *conn = cls_conn->dd_data;
3192         struct iscsi_session *session = conn->session;
3193
3194         switch (flag) {
3195         case STOP_CONN_RECOVER:
3196         case STOP_CONN_TERM:
3197                 iscsi_start_session_recovery(session, conn, flag);
3198                 break;
3199         default:
3200                 iscsi_conn_printk(KERN_ERR, conn,
3201                                   "invalid stop flag %d\n", flag);
3202         }
3203 }
3204 EXPORT_SYMBOL_GPL(iscsi_conn_stop);
3205
3206 int iscsi_conn_bind(struct iscsi_cls_session *cls_session,
3207                     struct iscsi_cls_conn *cls_conn, int is_leading)
3208 {
3209         struct iscsi_session *session = cls_session->dd_data;
3210         struct iscsi_conn *conn = cls_conn->dd_data;
3211
3212         spin_lock_bh(&session->frwd_lock);
3213         if (is_leading)
3214                 session->leadconn = conn;
3215         spin_unlock_bh(&session->frwd_lock);
3216
3217         /*
3218          * Unblock xmitworker(), Login Phase will pass through.
3219          */
3220         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
3221         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
3222         return 0;
3223 }
3224 EXPORT_SYMBOL_GPL(iscsi_conn_bind);
3225
3226 int iscsi_switch_str_param(char **param, char *new_val_buf)
3227 {
3228         char *new_val;
3229
3230         if (*param) {
3231                 if (!strcmp(*param, new_val_buf))
3232                         return 0;
3233         }
3234
3235         new_val = kstrdup(new_val_buf, GFP_NOIO);
3236         if (!new_val)
3237                 return -ENOMEM;
3238
3239         kfree(*param);
3240         *param = new_val;
3241         return 0;
3242 }
3243 EXPORT_SYMBOL_GPL(iscsi_switch_str_param);
3244
3245 int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
3246                     enum iscsi_param param, char *buf, int buflen)
3247 {
3248         struct iscsi_conn *conn = cls_conn->dd_data;
3249         struct iscsi_session *session = conn->session;
3250         int val;
3251
3252         switch(param) {
3253         case ISCSI_PARAM_FAST_ABORT:
3254                 sscanf(buf, "%d", &session->fast_abort);
3255                 break;
3256         case ISCSI_PARAM_ABORT_TMO:
3257                 sscanf(buf, "%d", &session->abort_timeout);
3258                 break;
3259         case ISCSI_PARAM_LU_RESET_TMO:
3260                 sscanf(buf, "%d", &session->lu_reset_timeout);
3261                 break;
3262         case ISCSI_PARAM_TGT_RESET_TMO:
3263                 sscanf(buf, "%d", &session->tgt_reset_timeout);
3264                 break;
3265         case ISCSI_PARAM_PING_TMO:
3266                 sscanf(buf, "%d", &conn->ping_timeout);
3267                 break;
3268         case ISCSI_PARAM_RECV_TMO:
3269                 sscanf(buf, "%d", &conn->recv_timeout);
3270                 break;
3271         case ISCSI_PARAM_MAX_RECV_DLENGTH:
3272                 sscanf(buf, "%d", &conn->max_recv_dlength);
3273                 break;
3274         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3275                 sscanf(buf, "%d", &conn->max_xmit_dlength);
3276                 break;
3277         case ISCSI_PARAM_HDRDGST_EN:
3278                 sscanf(buf, "%d", &conn->hdrdgst_en);
3279                 break;
3280         case ISCSI_PARAM_DATADGST_EN:
3281                 sscanf(buf, "%d", &conn->datadgst_en);
3282                 break;
3283         case ISCSI_PARAM_INITIAL_R2T_EN:
3284                 sscanf(buf, "%d", &session->initial_r2t_en);
3285                 break;
3286         case ISCSI_PARAM_MAX_R2T:
3287                 sscanf(buf, "%hu", &session->max_r2t);
3288                 break;
3289         case ISCSI_PARAM_IMM_DATA_EN:
3290                 sscanf(buf, "%d", &session->imm_data_en);
3291                 break;
3292         case ISCSI_PARAM_FIRST_BURST:
3293                 sscanf(buf, "%d", &session->first_burst);
3294                 break;
3295         case ISCSI_PARAM_MAX_BURST:
3296                 sscanf(buf, "%d", &session->max_burst);
3297                 break;
3298         case ISCSI_PARAM_PDU_INORDER_EN:
3299                 sscanf(buf, "%d", &session->pdu_inorder_en);
3300                 break;
3301         case ISCSI_PARAM_DATASEQ_INORDER_EN:
3302                 sscanf(buf, "%d", &session->dataseq_inorder_en);
3303                 break;
3304         case ISCSI_PARAM_ERL:
3305                 sscanf(buf, "%d", &session->erl);
3306                 break;
3307         case ISCSI_PARAM_EXP_STATSN:
3308                 sscanf(buf, "%u", &conn->exp_statsn);
3309                 break;
3310         case ISCSI_PARAM_USERNAME:
3311                 return iscsi_switch_str_param(&session->username, buf);
3312         case ISCSI_PARAM_USERNAME_IN:
3313                 return iscsi_switch_str_param(&session->username_in, buf);
3314         case ISCSI_PARAM_PASSWORD:
3315                 return iscsi_switch_str_param(&session->password, buf);
3316         case ISCSI_PARAM_PASSWORD_IN:
3317                 return iscsi_switch_str_param(&session->password_in, buf);
3318         case ISCSI_PARAM_TARGET_NAME:
3319                 return iscsi_switch_str_param(&session->targetname, buf);
3320         case ISCSI_PARAM_TARGET_ALIAS:
3321                 return iscsi_switch_str_param(&session->targetalias, buf);
3322         case ISCSI_PARAM_TPGT:
3323                 sscanf(buf, "%d", &session->tpgt);
3324                 break;
3325         case ISCSI_PARAM_PERSISTENT_PORT:
3326                 sscanf(buf, "%d", &conn->persistent_port);
3327                 break;
3328         case ISCSI_PARAM_PERSISTENT_ADDRESS:
3329                 return iscsi_switch_str_param(&conn->persistent_address, buf);
3330         case ISCSI_PARAM_IFACE_NAME:
3331                 return iscsi_switch_str_param(&session->ifacename, buf);
3332         case ISCSI_PARAM_INITIATOR_NAME:
3333                 return iscsi_switch_str_param(&session->initiatorname, buf);
3334         case ISCSI_PARAM_BOOT_ROOT:
3335                 return iscsi_switch_str_param(&session->boot_root, buf);
3336         case ISCSI_PARAM_BOOT_NIC:
3337                 return iscsi_switch_str_param(&session->boot_nic, buf);
3338         case ISCSI_PARAM_BOOT_TARGET:
3339                 return iscsi_switch_str_param(&session->boot_target, buf);
3340         case ISCSI_PARAM_PORTAL_TYPE:
3341                 return iscsi_switch_str_param(&session->portal_type, buf);
3342         case ISCSI_PARAM_DISCOVERY_PARENT_TYPE:
3343                 return iscsi_switch_str_param(&session->discovery_parent_type,
3344                                               buf);
3345         case ISCSI_PARAM_DISCOVERY_SESS:
3346                 sscanf(buf, "%d", &val);
3347                 session->discovery_sess = !!val;
3348                 break;
3349         case ISCSI_PARAM_LOCAL_IPADDR:
3350                 return iscsi_switch_str_param(&conn->local_ipaddr, buf);
3351         default:
3352                 return -ENOSYS;
3353         }
3354
3355         return 0;
3356 }
3357 EXPORT_SYMBOL_GPL(iscsi_set_param);
3358
3359 int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
3360                             enum iscsi_param param, char *buf)
3361 {
3362         struct iscsi_session *session = cls_session->dd_data;
3363         int len;
3364
3365         switch(param) {
3366         case ISCSI_PARAM_FAST_ABORT:
3367                 len = sprintf(buf, "%d\n", session->fast_abort);
3368                 break;
3369         case ISCSI_PARAM_ABORT_TMO:
3370                 len = sprintf(buf, "%d\n", session->abort_timeout);
3371                 break;
3372         case ISCSI_PARAM_LU_RESET_TMO:
3373                 len = sprintf(buf, "%d\n", session->lu_reset_timeout);
3374                 break;
3375         case ISCSI_PARAM_TGT_RESET_TMO:
3376                 len = sprintf(buf, "%d\n", session->tgt_reset_timeout);
3377                 break;
3378         case ISCSI_PARAM_INITIAL_R2T_EN:
3379                 len = sprintf(buf, "%d\n", session->initial_r2t_en);
3380                 break;
3381         case ISCSI_PARAM_MAX_R2T:
3382                 len = sprintf(buf, "%hu\n", session->max_r2t);
3383                 break;
3384         case ISCSI_PARAM_IMM_DATA_EN:
3385                 len = sprintf(buf, "%d\n", session->imm_data_en);
3386                 break;
3387         case ISCSI_PARAM_FIRST_BURST:
3388                 len = sprintf(buf, "%u\n", session->first_burst);
3389                 break;
3390         case ISCSI_PARAM_MAX_BURST:
3391                 len = sprintf(buf, "%u\n", session->max_burst);
3392                 break;
3393         case ISCSI_PARAM_PDU_INORDER_EN:
3394                 len = sprintf(buf, "%d\n", session->pdu_inorder_en);
3395                 break;
3396         case ISCSI_PARAM_DATASEQ_INORDER_EN:
3397                 len = sprintf(buf, "%d\n", session->dataseq_inorder_en);
3398                 break;
3399         case ISCSI_PARAM_DEF_TASKMGMT_TMO:
3400                 len = sprintf(buf, "%d\n", session->def_taskmgmt_tmo);
3401                 break;
3402         case ISCSI_PARAM_ERL:
3403                 len = sprintf(buf, "%d\n", session->erl);
3404                 break;
3405         case ISCSI_PARAM_TARGET_NAME:
3406                 len = sprintf(buf, "%s\n", session->targetname);
3407                 break;
3408         case ISCSI_PARAM_TARGET_ALIAS:
3409                 len = sprintf(buf, "%s\n", session->targetalias);
3410                 break;
3411         case ISCSI_PARAM_TPGT:
3412                 len = sprintf(buf, "%d\n", session->tpgt);
3413                 break;
3414         case ISCSI_PARAM_USERNAME:
3415                 len = sprintf(buf, "%s\n", session->username);
3416                 break;
3417         case ISCSI_PARAM_USERNAME_IN:
3418                 len = sprintf(buf, "%s\n", session->username_in);
3419                 break;
3420         case ISCSI_PARAM_PASSWORD:
3421                 len = sprintf(buf, "%s\n", session->password);
3422                 break;
3423         case ISCSI_PARAM_PASSWORD_IN:
3424                 len = sprintf(buf, "%s\n", session->password_in);
3425                 break;
3426         case ISCSI_PARAM_IFACE_NAME:
3427                 len = sprintf(buf, "%s\n", session->ifacename);
3428                 break;
3429         case ISCSI_PARAM_INITIATOR_NAME:
3430                 len = sprintf(buf, "%s\n", session->initiatorname);
3431                 break;
3432         case ISCSI_PARAM_BOOT_ROOT:
3433                 len = sprintf(buf, "%s\n", session->boot_root);
3434                 break;
3435         case ISCSI_PARAM_BOOT_NIC:
3436                 len = sprintf(buf, "%s\n", session->boot_nic);
3437                 break;
3438         case ISCSI_PARAM_BOOT_TARGET:
3439                 len = sprintf(buf, "%s\n", session->boot_target);
3440                 break;
3441         case ISCSI_PARAM_AUTO_SND_TGT_DISABLE:
3442                 len = sprintf(buf, "%u\n", session->auto_snd_tgt_disable);
3443                 break;
3444         case ISCSI_PARAM_DISCOVERY_SESS:
3445                 len = sprintf(buf, "%u\n", session->discovery_sess);
3446                 break;
3447         case ISCSI_PARAM_PORTAL_TYPE:
3448                 len = sprintf(buf, "%s\n", session->portal_type);
3449                 break;
3450         case ISCSI_PARAM_CHAP_AUTH_EN:
3451                 len = sprintf(buf, "%u\n", session->chap_auth_en);
3452                 break;
3453         case ISCSI_PARAM_DISCOVERY_LOGOUT_EN:
3454                 len = sprintf(buf, "%u\n", session->discovery_logout_en);
3455                 break;
3456         case ISCSI_PARAM_BIDI_CHAP_EN:
3457                 len = sprintf(buf, "%u\n", session->bidi_chap_en);
3458                 break;
3459         case ISCSI_PARAM_DISCOVERY_AUTH_OPTIONAL:
3460                 len = sprintf(buf, "%u\n", session->discovery_auth_optional);
3461                 break;
3462         case ISCSI_PARAM_DEF_TIME2WAIT:
3463                 len = sprintf(buf, "%d\n", session->time2wait);
3464                 break;
3465         case ISCSI_PARAM_DEF_TIME2RETAIN:
3466                 len = sprintf(buf, "%d\n", session->time2retain);
3467                 break;
3468         case ISCSI_PARAM_TSID:
3469                 len = sprintf(buf, "%u\n", session->tsid);
3470                 break;
3471         case ISCSI_PARAM_ISID:
3472                 len = sprintf(buf, "%02x%02x%02x%02x%02x%02x\n",
3473                               session->isid[0], session->isid[1],
3474                               session->isid[2], session->isid[3],
3475                               session->isid[4], session->isid[5]);
3476                 break;
3477         case ISCSI_PARAM_DISCOVERY_PARENT_IDX:
3478                 len = sprintf(buf, "%u\n", session->discovery_parent_idx);
3479                 break;
3480         case ISCSI_PARAM_DISCOVERY_PARENT_TYPE:
3481                 if (session->discovery_parent_type)
3482                         len = sprintf(buf, "%s\n",
3483                                       session->discovery_parent_type);
3484                 else
3485                         len = sprintf(buf, "\n");
3486                 break;
3487         default:
3488                 return -ENOSYS;
3489         }
3490
3491         return len;
3492 }
3493 EXPORT_SYMBOL_GPL(iscsi_session_get_param);
3494
3495 int iscsi_conn_get_addr_param(struct sockaddr_storage *addr,
3496                               enum iscsi_param param, char *buf)
3497 {
3498         struct sockaddr_in6 *sin6 = NULL;
3499         struct sockaddr_in *sin = NULL;
3500         int len;
3501
3502         switch (addr->ss_family) {
3503         case AF_INET:
3504                 sin = (struct sockaddr_in *)addr;
3505                 break;
3506         case AF_INET6:
3507                 sin6 = (struct sockaddr_in6 *)addr;
3508                 break;
3509         default:
3510                 return -EINVAL;
3511         }
3512
3513         switch (param) {
3514         case ISCSI_PARAM_CONN_ADDRESS:
3515         case ISCSI_HOST_PARAM_IPADDRESS:
3516                 if (sin)
3517                         len = sprintf(buf, "%pI4\n", &sin->sin_addr.s_addr);
3518                 else
3519                         len = sprintf(buf, "%pI6\n", &sin6->sin6_addr);
3520                 break;
3521         case ISCSI_PARAM_CONN_PORT:
3522         case ISCSI_PARAM_LOCAL_PORT:
3523                 if (sin)
3524                         len = sprintf(buf, "%hu\n", be16_to_cpu(sin->sin_port));
3525                 else
3526                         len = sprintf(buf, "%hu\n",
3527                                       be16_to_cpu(sin6->sin6_port));
3528                 break;
3529         default:
3530                 return -EINVAL;
3531         }
3532
3533         return len;
3534 }
3535 EXPORT_SYMBOL_GPL(iscsi_conn_get_addr_param);
3536
3537 int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
3538                          enum iscsi_param param, char *buf)
3539 {
3540         struct iscsi_conn *conn = cls_conn->dd_data;
3541         int len;
3542
3543         switch(param) {
3544         case ISCSI_PARAM_PING_TMO:
3545                 len = sprintf(buf, "%u\n", conn->ping_timeout);
3546                 break;
3547         case ISCSI_PARAM_RECV_TMO:
3548                 len = sprintf(buf, "%u\n", conn->recv_timeout);
3549                 break;
3550         case ISCSI_PARAM_MAX_RECV_DLENGTH:
3551                 len = sprintf(buf, "%u\n", conn->max_recv_dlength);
3552                 break;
3553         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3554                 len = sprintf(buf, "%u\n", conn->max_xmit_dlength);
3555                 break;
3556         case ISCSI_PARAM_HDRDGST_EN:
3557                 len = sprintf(buf, "%d\n", conn->hdrdgst_en);
3558                 break;
3559         case ISCSI_PARAM_DATADGST_EN:
3560                 len = sprintf(buf, "%d\n", conn->datadgst_en);
3561                 break;
3562         case ISCSI_PARAM_IFMARKER_EN:
3563                 len = sprintf(buf, "%d\n", conn->ifmarker_en);
3564                 break;
3565         case ISCSI_PARAM_OFMARKER_EN:
3566                 len = sprintf(buf, "%d\n", conn->ofmarker_en);
3567                 break;
3568         case ISCSI_PARAM_EXP_STATSN:
3569                 len = sprintf(buf, "%u\n", conn->exp_statsn);
3570                 break;
3571         case ISCSI_PARAM_PERSISTENT_PORT:
3572                 len = sprintf(buf, "%d\n", conn->persistent_port);
3573                 break;
3574         case ISCSI_PARAM_PERSISTENT_ADDRESS:
3575                 len = sprintf(buf, "%s\n", conn->persistent_address);
3576                 break;
3577         case ISCSI_PARAM_STATSN:
3578                 len = sprintf(buf, "%u\n", conn->statsn);
3579                 break;
3580         case ISCSI_PARAM_MAX_SEGMENT_SIZE:
3581                 len = sprintf(buf, "%u\n", conn->max_segment_size);
3582                 break;
3583         case ISCSI_PARAM_KEEPALIVE_TMO:
3584                 len = sprintf(buf, "%u\n", conn->keepalive_tmo);
3585                 break;
3586         case ISCSI_PARAM_LOCAL_PORT:
3587                 len = sprintf(buf, "%u\n", conn->local_port);
3588                 break;
3589         case ISCSI_PARAM_TCP_TIMESTAMP_STAT:
3590                 len = sprintf(buf, "%u\n", conn->tcp_timestamp_stat);
3591                 break;
3592         case ISCSI_PARAM_TCP_NAGLE_DISABLE:
3593                 len = sprintf(buf, "%u\n", conn->tcp_nagle_disable);
3594                 break;
3595         case ISCSI_PARAM_TCP_WSF_DISABLE:
3596                 len = sprintf(buf, "%u\n", conn->tcp_wsf_disable);
3597                 break;
3598         case ISCSI_PARAM_TCP_TIMER_SCALE:
3599                 len = sprintf(buf, "%u\n", conn->tcp_timer_scale);
3600                 break;
3601         case ISCSI_PARAM_TCP_TIMESTAMP_EN:
3602                 len = sprintf(buf, "%u\n", conn->tcp_timestamp_en);
3603                 break;
3604         case ISCSI_PARAM_IP_FRAGMENT_DISABLE:
3605                 len = sprintf(buf, "%u\n", conn->fragment_disable);
3606                 break;
3607         case ISCSI_PARAM_IPV4_TOS:
3608                 len = sprintf(buf, "%u\n", conn->ipv4_tos);
3609                 break;
3610         case ISCSI_PARAM_IPV6_TC:
3611                 len = sprintf(buf, "%u\n", conn->ipv6_traffic_class);
3612                 break;
3613         case ISCSI_PARAM_IPV6_FLOW_LABEL:
3614                 len = sprintf(buf, "%u\n", conn->ipv6_flow_label);
3615                 break;
3616         case ISCSI_PARAM_IS_FW_ASSIGNED_IPV6:
3617                 len = sprintf(buf, "%u\n", conn->is_fw_assigned_ipv6);
3618                 break;
3619         case ISCSI_PARAM_TCP_XMIT_WSF:
3620                 len = sprintf(buf, "%u\n", conn->tcp_xmit_wsf);
3621                 break;
3622         case ISCSI_PARAM_TCP_RECV_WSF:
3623                 len = sprintf(buf, "%u\n", conn->tcp_recv_wsf);
3624                 break;
3625         case ISCSI_PARAM_LOCAL_IPADDR:
3626                 len = sprintf(buf, "%s\n", conn->local_ipaddr);
3627                 break;
3628         default:
3629                 return -ENOSYS;
3630         }
3631
3632         return len;
3633 }
3634 EXPORT_SYMBOL_GPL(iscsi_conn_get_param);
3635
3636 int iscsi_host_get_param(struct Scsi_Host *shost, enum iscsi_host_param param,
3637                          char *buf)
3638 {
3639         struct iscsi_host *ihost = shost_priv(shost);
3640         int len;
3641
3642         switch (param) {
3643         case ISCSI_HOST_PARAM_NETDEV_NAME:
3644                 len = sprintf(buf, "%s\n", ihost->netdev);
3645                 break;
3646         case ISCSI_HOST_PARAM_HWADDRESS:
3647                 len = sprintf(buf, "%s\n", ihost->hwaddress);
3648                 break;
3649         case ISCSI_HOST_PARAM_INITIATOR_NAME:
3650                 len = sprintf(buf, "%s\n", ihost->initiatorname);
3651                 break;
3652         default:
3653                 return -ENOSYS;
3654         }
3655
3656         return len;
3657 }
3658 EXPORT_SYMBOL_GPL(iscsi_host_get_param);
3659
3660 int iscsi_host_set_param(struct Scsi_Host *shost, enum iscsi_host_param param,
3661                          char *buf, int buflen)
3662 {
3663         struct iscsi_host *ihost = shost_priv(shost);
3664
3665         switch (param) {
3666         case ISCSI_HOST_PARAM_NETDEV_NAME:
3667                 return iscsi_switch_str_param(&ihost->netdev, buf);
3668         case ISCSI_HOST_PARAM_HWADDRESS:
3669                 return iscsi_switch_str_param(&ihost->hwaddress, buf);
3670         case ISCSI_HOST_PARAM_INITIATOR_NAME:
3671                 return iscsi_switch_str_param(&ihost->initiatorname, buf);
3672         default:
3673                 return -ENOSYS;
3674         }
3675
3676         return 0;
3677 }
3678 EXPORT_SYMBOL_GPL(iscsi_host_set_param);
3679
3680 MODULE_AUTHOR("Mike Christie");
3681 MODULE_DESCRIPTION("iSCSI library functions");
3682 MODULE_LICENSE("GPL");