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