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 int 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 -EINVAL;
 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                 return -EIO;
1002         } else if (!rhdr) {
1003                 /* only track our nops */
1004                 conn->ping_task = task;
1005                 conn->last_ping = jiffies;
1006         }
1007
1008         return 0;
1009 }
1010
1011 static int iscsi_nop_out_rsp(struct iscsi_task *task,
1012                              struct iscsi_nopin *nop, char *data, int datalen)
1013 {
1014         struct iscsi_conn *conn = task->conn;
1015         int rc = 0;
1016
1017         if (conn->ping_task != task) {
1018                 /*
1019                  * If this is not in response to one of our
1020                  * nops then it must be from userspace.
1021                  */
1022                 if (iscsi_recv_pdu(conn->cls_conn, (struct iscsi_hdr *)nop,
1023                                    data, datalen))
1024                         rc = ISCSI_ERR_CONN_FAILED;
1025         } else
1026                 mod_timer(&conn->transport_timer, jiffies + conn->recv_timeout);
1027         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1028         return rc;
1029 }
1030
1031 static int iscsi_handle_reject(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1032                                char *data, int datalen)
1033 {
1034         struct iscsi_reject *reject = (struct iscsi_reject *)hdr;
1035         struct iscsi_hdr rejected_pdu;
1036         int opcode, rc = 0;
1037
1038         conn->exp_statsn = be32_to_cpu(reject->statsn) + 1;
1039
1040         if (ntoh24(reject->dlength) > datalen ||
1041             ntoh24(reject->dlength) < sizeof(struct iscsi_hdr)) {
1042                 iscsi_conn_printk(KERN_ERR, conn, "Cannot handle rejected "
1043                                   "pdu. Invalid data length (pdu dlength "
1044                                   "%u, datalen %d\n", ntoh24(reject->dlength),
1045                                   datalen);
1046                 return ISCSI_ERR_PROTO;
1047         }
1048         memcpy(&rejected_pdu, data, sizeof(struct iscsi_hdr));
1049         opcode = rejected_pdu.opcode & ISCSI_OPCODE_MASK;
1050
1051         switch (reject->reason) {
1052         case ISCSI_REASON_DATA_DIGEST_ERROR:
1053                 iscsi_conn_printk(KERN_ERR, conn,
1054                                   "pdu (op 0x%x itt 0x%x) rejected "
1055                                   "due to DataDigest error.\n",
1056                                   opcode, rejected_pdu.itt);
1057                 break;
1058         case ISCSI_REASON_IMM_CMD_REJECT:
1059                 iscsi_conn_printk(KERN_ERR, conn,
1060                                   "pdu (op 0x%x itt 0x%x) rejected. Too many "
1061                                   "immediate commands.\n",
1062                                   opcode, rejected_pdu.itt);
1063                 /*
1064                  * We only send one TMF at a time so if the target could not
1065                  * handle it, then it should get fixed (RFC mandates that
1066                  * a target can handle one immediate TMF per conn).
1067                  *
1068                  * For nops-outs, we could have sent more than one if
1069                  * the target is sending us lots of nop-ins
1070                  */
1071                 if (opcode != ISCSI_OP_NOOP_OUT)
1072                         return 0;
1073
1074                  if (rejected_pdu.itt == cpu_to_be32(ISCSI_RESERVED_TAG)) {
1075                         /*
1076                          * nop-out in response to target's nop-out rejected.
1077                          * Just resend.
1078                          */
1079                         /* In RX path we are under back lock */
1080                         spin_unlock(&conn->session->back_lock);
1081                         spin_lock(&conn->session->frwd_lock);
1082                         iscsi_send_nopout(conn,
1083                                           (struct iscsi_nopin*)&rejected_pdu);
1084                         spin_unlock(&conn->session->frwd_lock);
1085                         spin_lock(&conn->session->back_lock);
1086                 } else {
1087                         struct iscsi_task *task;
1088                         /*
1089                          * Our nop as ping got dropped. We know the target
1090                          * and transport are ok so just clean up
1091                          */
1092                         task = iscsi_itt_to_task(conn, rejected_pdu.itt);
1093                         if (!task) {
1094                                 iscsi_conn_printk(KERN_ERR, conn,
1095                                                  "Invalid pdu reject. Could "
1096                                                  "not lookup rejected task.\n");
1097                                 rc = ISCSI_ERR_BAD_ITT;
1098                         } else
1099                                 rc = iscsi_nop_out_rsp(task,
1100                                         (struct iscsi_nopin*)&rejected_pdu,
1101                                         NULL, 0);
1102                 }
1103                 break;
1104         default:
1105                 iscsi_conn_printk(KERN_ERR, conn,
1106                                   "pdu (op 0x%x itt 0x%x) rejected. Reason "
1107                                   "code 0x%x\n", rejected_pdu.opcode,
1108                                   rejected_pdu.itt, reject->reason);
1109                 break;
1110         }
1111         return rc;
1112 }
1113
1114 /**
1115  * iscsi_itt_to_task - look up task by itt
1116  * @conn: iscsi connection
1117  * @itt: itt
1118  *
1119  * This should be used for mgmt tasks like login and nops, or if
1120  * the LDD's itt space does not include the session age.
1121  *
1122  * The session back_lock must be held.
1123  */
1124 struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *conn, itt_t itt)
1125 {
1126         struct iscsi_session *session = conn->session;
1127         int i;
1128
1129         if (itt == RESERVED_ITT)
1130                 return NULL;
1131
1132         if (session->tt->parse_pdu_itt)
1133                 session->tt->parse_pdu_itt(conn, itt, &i, NULL);
1134         else
1135                 i = get_itt(itt);
1136         if (i >= session->cmds_max)
1137                 return NULL;
1138
1139         return session->cmds[i];
1140 }
1141 EXPORT_SYMBOL_GPL(iscsi_itt_to_task);
1142
1143 /**
1144  * __iscsi_complete_pdu - complete pdu
1145  * @conn: iscsi conn
1146  * @hdr: iscsi header
1147  * @data: data buffer
1148  * @datalen: len of data buffer
1149  *
1150  * Completes pdu processing by freeing any resources allocated at
1151  * queuecommand or send generic. session back_lock must be held and verify
1152  * itt must have been called.
1153  */
1154 int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1155                          char *data, int datalen)
1156 {
1157         struct iscsi_session *session = conn->session;
1158         int opcode = hdr->opcode & ISCSI_OPCODE_MASK, rc = 0;
1159         struct iscsi_task *task;
1160         uint32_t itt;
1161
1162         conn->last_recv = jiffies;
1163         rc = iscsi_verify_itt(conn, hdr->itt);
1164         if (rc)
1165                 return rc;
1166
1167         if (hdr->itt != RESERVED_ITT)
1168                 itt = get_itt(hdr->itt);
1169         else
1170                 itt = ~0U;
1171
1172         ISCSI_DBG_SESSION(session, "[op 0x%x cid %d itt 0x%x len %d]\n",
1173                           opcode, conn->id, itt, datalen);
1174
1175         if (itt == ~0U) {
1176                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1177
1178                 switch(opcode) {
1179                 case ISCSI_OP_NOOP_IN:
1180                         if (datalen) {
1181                                 rc = ISCSI_ERR_PROTO;
1182                                 break;
1183                         }
1184
1185                         if (hdr->ttt == cpu_to_be32(ISCSI_RESERVED_TAG))
1186                                 break;
1187
1188                         /* In RX path we are under back lock */
1189                         spin_unlock(&session->back_lock);
1190                         spin_lock(&session->frwd_lock);
1191                         iscsi_send_nopout(conn, (struct iscsi_nopin*)hdr);
1192                         spin_unlock(&session->frwd_lock);
1193                         spin_lock(&session->back_lock);
1194                         break;
1195                 case ISCSI_OP_REJECT:
1196                         rc = iscsi_handle_reject(conn, hdr, data, datalen);
1197                         break;
1198                 case ISCSI_OP_ASYNC_EVENT:
1199                         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1200                         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
1201                                 rc = ISCSI_ERR_CONN_FAILED;
1202                         break;
1203                 default:
1204                         rc = ISCSI_ERR_BAD_OPCODE;
1205                         break;
1206                 }
1207                 goto out;
1208         }
1209
1210         switch(opcode) {
1211         case ISCSI_OP_SCSI_CMD_RSP:
1212         case ISCSI_OP_SCSI_DATA_IN:
1213                 task = iscsi_itt_to_ctask(conn, hdr->itt);
1214                 if (!task)
1215                         return ISCSI_ERR_BAD_ITT;
1216                 task->last_xfer = jiffies;
1217                 break;
1218         case ISCSI_OP_R2T:
1219                 /*
1220                  * LLD handles R2Ts if they need to.
1221                  */
1222                 return 0;
1223         case ISCSI_OP_LOGOUT_RSP:
1224         case ISCSI_OP_LOGIN_RSP:
1225         case ISCSI_OP_TEXT_RSP:
1226         case ISCSI_OP_SCSI_TMFUNC_RSP:
1227         case ISCSI_OP_NOOP_IN:
1228                 task = iscsi_itt_to_task(conn, hdr->itt);
1229                 if (!task)
1230                         return ISCSI_ERR_BAD_ITT;
1231                 break;
1232         default:
1233                 return ISCSI_ERR_BAD_OPCODE;
1234         }
1235
1236         switch(opcode) {
1237         case ISCSI_OP_SCSI_CMD_RSP:
1238                 iscsi_scsi_cmd_rsp(conn, hdr, task, data, datalen);
1239                 break;
1240         case ISCSI_OP_SCSI_DATA_IN:
1241                 iscsi_data_in_rsp(conn, hdr, task);
1242                 break;
1243         case ISCSI_OP_LOGOUT_RSP:
1244                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1245                 if (datalen) {
1246                         rc = ISCSI_ERR_PROTO;
1247                         break;
1248                 }
1249                 conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1250                 goto recv_pdu;
1251         case ISCSI_OP_LOGIN_RSP:
1252         case ISCSI_OP_TEXT_RSP:
1253                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1254                 /*
1255                  * login related PDU's exp_statsn is handled in
1256                  * userspace
1257                  */
1258                 goto recv_pdu;
1259         case ISCSI_OP_SCSI_TMFUNC_RSP:
1260                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1261                 if (datalen) {
1262                         rc = ISCSI_ERR_PROTO;
1263                         break;
1264                 }
1265
1266                 iscsi_tmf_rsp(conn, hdr);
1267                 iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1268                 break;
1269         case ISCSI_OP_NOOP_IN:
1270                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1271                 if (hdr->ttt != cpu_to_be32(ISCSI_RESERVED_TAG) || datalen) {
1272                         rc = ISCSI_ERR_PROTO;
1273                         break;
1274                 }
1275                 conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1276
1277                 rc = iscsi_nop_out_rsp(task, (struct iscsi_nopin*)hdr,
1278                                        data, datalen);
1279                 break;
1280         default:
1281                 rc = ISCSI_ERR_BAD_OPCODE;
1282                 break;
1283         }
1284
1285 out:
1286         return rc;
1287 recv_pdu:
1288         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
1289                 rc = ISCSI_ERR_CONN_FAILED;
1290         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1291         return rc;
1292 }
1293 EXPORT_SYMBOL_GPL(__iscsi_complete_pdu);
1294
1295 int iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1296                        char *data, int datalen)
1297 {
1298         int rc;
1299
1300         spin_lock(&conn->session->back_lock);
1301         rc = __iscsi_complete_pdu(conn, hdr, data, datalen);
1302         spin_unlock(&conn->session->back_lock);
1303         return rc;
1304 }
1305 EXPORT_SYMBOL_GPL(iscsi_complete_pdu);
1306
1307 int iscsi_verify_itt(struct iscsi_conn *conn, itt_t itt)
1308 {
1309         struct iscsi_session *session = conn->session;
1310         int age = 0, i = 0;
1311
1312         if (itt == RESERVED_ITT)
1313                 return 0;
1314
1315         if (session->tt->parse_pdu_itt)
1316                 session->tt->parse_pdu_itt(conn, itt, &i, &age);
1317         else {
1318                 i = get_itt(itt);
1319                 age = ((__force u32)itt >> ISCSI_AGE_SHIFT) & ISCSI_AGE_MASK;
1320         }
1321
1322         if (age != session->age) {
1323                 iscsi_conn_printk(KERN_ERR, conn,
1324                                   "received itt %x expected session age (%x)\n",
1325                                   (__force u32)itt, session->age);
1326                 return ISCSI_ERR_BAD_ITT;
1327         }
1328
1329         if (i >= session->cmds_max) {
1330                 iscsi_conn_printk(KERN_ERR, conn,
1331                                   "received invalid itt index %u (max cmds "
1332                                    "%u.\n", i, session->cmds_max);
1333                 return ISCSI_ERR_BAD_ITT;
1334         }
1335         return 0;
1336 }
1337 EXPORT_SYMBOL_GPL(iscsi_verify_itt);
1338
1339 /**
1340  * iscsi_itt_to_ctask - look up ctask by itt
1341  * @conn: iscsi connection
1342  * @itt: itt
1343  *
1344  * This should be used for cmd tasks.
1345  *
1346  * The session back_lock must be held.
1347  */
1348 struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *conn, itt_t itt)
1349 {
1350         struct iscsi_task *task;
1351
1352         if (iscsi_verify_itt(conn, itt))
1353                 return NULL;
1354
1355         task = iscsi_itt_to_task(conn, itt);
1356         if (!task || !task->sc)
1357                 return NULL;
1358
1359         if (task->sc->SCp.phase != conn->session->age) {
1360                 iscsi_session_printk(KERN_ERR, conn->session,
1361                                   "task's session age %d, expected %d\n",
1362                                   task->sc->SCp.phase, conn->session->age);
1363                 return NULL;
1364         }
1365
1366         return task;
1367 }
1368 EXPORT_SYMBOL_GPL(iscsi_itt_to_ctask);
1369
1370 void iscsi_session_failure(struct iscsi_session *session,
1371                            enum iscsi_err err)
1372 {
1373         struct iscsi_conn *conn;
1374         struct device *dev;
1375
1376         spin_lock_bh(&session->frwd_lock);
1377         conn = session->leadconn;
1378         if (session->state == ISCSI_STATE_TERMINATE || !conn) {
1379                 spin_unlock_bh(&session->frwd_lock);
1380                 return;
1381         }
1382
1383         dev = get_device(&conn->cls_conn->dev);
1384         spin_unlock_bh(&session->frwd_lock);
1385         if (!dev)
1386                 return;
1387         /*
1388          * if the host is being removed bypass the connection
1389          * recovery initialization because we are going to kill
1390          * the session.
1391          */
1392         if (err == ISCSI_ERR_INVALID_HOST)
1393                 iscsi_conn_error_event(conn->cls_conn, err);
1394         else
1395                 iscsi_conn_failure(conn, err);
1396         put_device(dev);
1397 }
1398 EXPORT_SYMBOL_GPL(iscsi_session_failure);
1399
1400 void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err)
1401 {
1402         struct iscsi_session *session = conn->session;
1403
1404         spin_lock_bh(&session->frwd_lock);
1405         if (session->state == ISCSI_STATE_FAILED) {
1406                 spin_unlock_bh(&session->frwd_lock);
1407                 return;
1408         }
1409
1410         if (conn->stop_stage == 0)
1411                 session->state = ISCSI_STATE_FAILED;
1412         spin_unlock_bh(&session->frwd_lock);
1413
1414         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1415         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
1416         iscsi_conn_error_event(conn->cls_conn, err);
1417 }
1418 EXPORT_SYMBOL_GPL(iscsi_conn_failure);
1419
1420 static int iscsi_check_cmdsn_window_closed(struct iscsi_conn *conn)
1421 {
1422         struct iscsi_session *session = conn->session;
1423
1424         /*
1425          * Check for iSCSI window and take care of CmdSN wrap-around
1426          */
1427         if (!iscsi_sna_lte(session->queued_cmdsn, session->max_cmdsn)) {
1428                 ISCSI_DBG_SESSION(session, "iSCSI CmdSN closed. ExpCmdSn "
1429                                   "%u MaxCmdSN %u CmdSN %u/%u\n",
1430                                   session->exp_cmdsn, session->max_cmdsn,
1431                                   session->cmdsn, session->queued_cmdsn);
1432                 return -ENOSPC;
1433         }
1434         return 0;
1435 }
1436
1437 static int iscsi_xmit_task(struct iscsi_conn *conn)
1438 {
1439         struct iscsi_task *task = conn->task;
1440         int rc;
1441
1442         if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx))
1443                 return -ENODATA;
1444
1445         __iscsi_get_task(task);
1446         spin_unlock_bh(&conn->session->frwd_lock);
1447         rc = conn->session->tt->xmit_task(task);
1448         spin_lock_bh(&conn->session->frwd_lock);
1449         if (!rc) {
1450                 /* done with this task */
1451                 task->last_xfer = jiffies;
1452                 conn->task = NULL;
1453         }
1454         /* regular RX path uses back_lock */
1455         spin_lock(&conn->session->back_lock);
1456         __iscsi_put_task(task);
1457         spin_unlock(&conn->session->back_lock);
1458         return rc;
1459 }
1460
1461 /**
1462  * iscsi_requeue_task - requeue task to run from session workqueue
1463  * @task: task to requeue
1464  *
1465  * LLDs that need to run a task from the session workqueue should call
1466  * this. The session frwd_lock must be held. This should only be called
1467  * by software drivers.
1468  */
1469 void iscsi_requeue_task(struct iscsi_task *task)
1470 {
1471         struct iscsi_conn *conn = task->conn;
1472
1473         /*
1474          * this may be on the requeue list already if the xmit_task callout
1475          * is handling the r2ts while we are adding new ones
1476          */
1477         if (list_empty(&task->running))
1478                 list_add_tail(&task->running, &conn->requeue);
1479         iscsi_conn_queue_work(conn);
1480 }
1481 EXPORT_SYMBOL_GPL(iscsi_requeue_task);
1482
1483 /**
1484  * iscsi_data_xmit - xmit any command into the scheduled connection
1485  * @conn: iscsi connection
1486  *
1487  * Notes:
1488  *      The function can return -EAGAIN in which case the caller must
1489  *      re-schedule it again later or recover. '0' return code means
1490  *      successful xmit.
1491  **/
1492 static int iscsi_data_xmit(struct iscsi_conn *conn)
1493 {
1494         struct iscsi_task *task;
1495         int rc = 0;
1496
1497         spin_lock_bh(&conn->session->frwd_lock);
1498         if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx)) {
1499                 ISCSI_DBG_SESSION(conn->session, "Tx suspended!\n");
1500                 spin_unlock_bh(&conn->session->frwd_lock);
1501                 return -ENODATA;
1502         }
1503
1504         if (conn->task) {
1505                 rc = iscsi_xmit_task(conn);
1506                 if (rc)
1507                         goto done;
1508         }
1509
1510         /*
1511          * process mgmt pdus like nops before commands since we should
1512          * only have one nop-out as a ping from us and targets should not
1513          * overflow us with nop-ins
1514          */
1515 check_mgmt:
1516         while (!list_empty(&conn->mgmtqueue)) {
1517                 conn->task = list_entry(conn->mgmtqueue.next,
1518                                          struct iscsi_task, running);
1519                 list_del_init(&conn->task->running);
1520                 if (iscsi_prep_mgmt_task(conn, conn->task)) {
1521                         /* regular RX path uses back_lock */
1522                         spin_lock_bh(&conn->session->back_lock);
1523                         __iscsi_put_task(conn->task);
1524                         spin_unlock_bh(&conn->session->back_lock);
1525                         conn->task = NULL;
1526                         continue;
1527                 }
1528                 rc = iscsi_xmit_task(conn);
1529                 if (rc)
1530                         goto done;
1531         }
1532
1533         /* process pending command queue */
1534         while (!list_empty(&conn->cmdqueue)) {
1535                 conn->task = list_entry(conn->cmdqueue.next, struct iscsi_task,
1536                                         running);
1537                 list_del_init(&conn->task->running);
1538                 if (conn->session->state == ISCSI_STATE_LOGGING_OUT) {
1539                         fail_scsi_task(conn->task, DID_IMM_RETRY);
1540                         continue;
1541                 }
1542                 rc = iscsi_prep_scsi_cmd_pdu(conn->task);
1543                 if (rc) {
1544                         if (rc == -ENOMEM || rc == -EACCES) {
1545                                 list_add_tail(&conn->task->running,
1546                                               &conn->cmdqueue);
1547                                 conn->task = NULL;
1548                                 goto done;
1549                         } else
1550                                 fail_scsi_task(conn->task, DID_ABORT);
1551                         continue;
1552                 }
1553                 rc = iscsi_xmit_task(conn);
1554                 if (rc)
1555                         goto done;
1556                 /*
1557                  * we could continuously get new task requests so
1558                  * we need to check the mgmt queue for nops that need to
1559                  * be sent to aviod starvation
1560                  */
1561                 if (!list_empty(&conn->mgmtqueue))
1562                         goto check_mgmt;
1563         }
1564
1565         while (!list_empty(&conn->requeue)) {
1566                 /*
1567                  * we always do fastlogout - conn stop code will clean up.
1568                  */
1569                 if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
1570                         break;
1571
1572                 task = list_entry(conn->requeue.next, struct iscsi_task,
1573                                   running);
1574                 if (iscsi_check_tmf_restrictions(task, ISCSI_OP_SCSI_DATA_OUT))
1575                         break;
1576
1577                 conn->task = task;
1578                 list_del_init(&conn->task->running);
1579                 conn->task->state = ISCSI_TASK_RUNNING;
1580                 rc = iscsi_xmit_task(conn);
1581                 if (rc)
1582                         goto done;
1583                 if (!list_empty(&conn->mgmtqueue))
1584                         goto check_mgmt;
1585         }
1586         spin_unlock_bh(&conn->session->frwd_lock);
1587         return -ENODATA;
1588
1589 done:
1590         spin_unlock_bh(&conn->session->frwd_lock);
1591         return rc;
1592 }
1593
1594 static void iscsi_xmitworker(struct work_struct *work)
1595 {
1596         struct iscsi_conn *conn =
1597                 container_of(work, struct iscsi_conn, xmitwork);
1598         int rc;
1599         /*
1600          * serialize Xmit worker on a per-connection basis.
1601          */
1602         do {
1603                 rc = iscsi_data_xmit(conn);
1604         } while (rc >= 0 || rc == -EAGAIN);
1605 }
1606
1607 static inline struct iscsi_task *iscsi_alloc_task(struct iscsi_conn *conn,
1608                                                   struct scsi_cmnd *sc)
1609 {
1610         struct iscsi_task *task;
1611
1612         if (!kfifo_out(&conn->session->cmdpool.queue,
1613                          (void *) &task, sizeof(void *)))
1614                 return NULL;
1615
1616         sc->SCp.phase = conn->session->age;
1617         sc->SCp.ptr = (char *) task;
1618
1619         atomic_set(&task->refcount, 1);
1620         task->state = ISCSI_TASK_PENDING;
1621         task->conn = conn;
1622         task->sc = sc;
1623         task->have_checked_conn = false;
1624         task->last_timeout = jiffies;
1625         task->last_xfer = jiffies;
1626         task->protected = false;
1627         INIT_LIST_HEAD(&task->running);
1628         return task;
1629 }
1630
1631 enum {
1632         FAILURE_BAD_HOST = 1,
1633         FAILURE_SESSION_FAILED,
1634         FAILURE_SESSION_FREED,
1635         FAILURE_WINDOW_CLOSED,
1636         FAILURE_OOM,
1637         FAILURE_SESSION_TERMINATE,
1638         FAILURE_SESSION_IN_RECOVERY,
1639         FAILURE_SESSION_RECOVERY_TIMEOUT,
1640         FAILURE_SESSION_LOGGING_OUT,
1641         FAILURE_SESSION_NOT_READY,
1642 };
1643
1644 int iscsi_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *sc)
1645 {
1646         struct iscsi_cls_session *cls_session;
1647         struct iscsi_host *ihost;
1648         int reason = 0;
1649         struct iscsi_session *session;
1650         struct iscsi_conn *conn;
1651         struct iscsi_task *task = NULL;
1652
1653         sc->result = 0;
1654         sc->SCp.ptr = NULL;
1655
1656         ihost = shost_priv(host);
1657
1658         cls_session = starget_to_session(scsi_target(sc->device));
1659         session = cls_session->dd_data;
1660         spin_lock_bh(&session->frwd_lock);
1661
1662         reason = iscsi_session_chkready(cls_session);
1663         if (reason) {
1664                 sc->result = reason;
1665                 goto fault;
1666         }
1667
1668         if (session->state != ISCSI_STATE_LOGGED_IN) {
1669                 /*
1670                  * to handle the race between when we set the recovery state
1671                  * and block the session we requeue here (commands could
1672                  * be entering our queuecommand while a block is starting
1673                  * up because the block code is not locked)
1674                  */
1675                 switch (session->state) {
1676                 case ISCSI_STATE_FAILED:
1677                 case ISCSI_STATE_IN_RECOVERY:
1678                         reason = FAILURE_SESSION_IN_RECOVERY;
1679                         sc->result = DID_IMM_RETRY << 16;
1680                         break;
1681                 case ISCSI_STATE_LOGGING_OUT:
1682                         reason = FAILURE_SESSION_LOGGING_OUT;
1683                         sc->result = DID_IMM_RETRY << 16;
1684                         break;
1685                 case ISCSI_STATE_RECOVERY_FAILED:
1686                         reason = FAILURE_SESSION_RECOVERY_TIMEOUT;
1687                         sc->result = DID_TRANSPORT_FAILFAST << 16;
1688                         break;
1689                 case ISCSI_STATE_TERMINATE:
1690                         reason = FAILURE_SESSION_TERMINATE;
1691                         sc->result = DID_NO_CONNECT << 16;
1692                         break;
1693                 default:
1694                         reason = FAILURE_SESSION_FREED;
1695                         sc->result = DID_NO_CONNECT << 16;
1696                 }
1697                 goto fault;
1698         }
1699
1700         conn = session->leadconn;
1701         if (!conn) {
1702                 reason = FAILURE_SESSION_FREED;
1703                 sc->result = DID_NO_CONNECT << 16;
1704                 goto fault;
1705         }
1706
1707         if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx)) {
1708                 reason = FAILURE_SESSION_IN_RECOVERY;
1709                 sc->result = DID_REQUEUE;
1710                 goto fault;
1711         }
1712
1713         if (iscsi_check_cmdsn_window_closed(conn)) {
1714                 reason = FAILURE_WINDOW_CLOSED;
1715                 goto reject;
1716         }
1717
1718         task = iscsi_alloc_task(conn, sc);
1719         if (!task) {
1720                 reason = FAILURE_OOM;
1721                 goto reject;
1722         }
1723
1724         if (!ihost->workq) {
1725                 reason = iscsi_prep_scsi_cmd_pdu(task);
1726                 if (reason) {
1727                         if (reason == -ENOMEM ||  reason == -EACCES) {
1728                                 reason = FAILURE_OOM;
1729                                 goto prepd_reject;
1730                         } else {
1731                                 sc->result = DID_ABORT << 16;
1732                                 goto prepd_fault;
1733                         }
1734                 }
1735                 if (session->tt->xmit_task(task)) {
1736                         session->cmdsn--;
1737                         reason = FAILURE_SESSION_NOT_READY;
1738                         goto prepd_reject;
1739                 }
1740         } else {
1741                 list_add_tail(&task->running, &conn->cmdqueue);
1742                 iscsi_conn_queue_work(conn);
1743         }
1744
1745         session->queued_cmdsn++;
1746         spin_unlock_bh(&session->frwd_lock);
1747         return 0;
1748
1749 prepd_reject:
1750         iscsi_complete_task(task, ISCSI_TASK_REQUEUE_SCSIQ);
1751 reject:
1752         spin_unlock_bh(&session->frwd_lock);
1753         ISCSI_DBG_SESSION(session, "cmd 0x%x rejected (%d)\n",
1754                           sc->cmnd[0], reason);
1755         return SCSI_MLQUEUE_TARGET_BUSY;
1756
1757 prepd_fault:
1758         iscsi_complete_task(task, ISCSI_TASK_REQUEUE_SCSIQ);
1759 fault:
1760         spin_unlock_bh(&session->frwd_lock);
1761         ISCSI_DBG_SESSION(session, "iscsi: cmd 0x%x is not queued (%d)\n",
1762                           sc->cmnd[0], reason);
1763         if (!scsi_bidi_cmnd(sc))
1764                 scsi_set_resid(sc, scsi_bufflen(sc));
1765         else {
1766                 scsi_out(sc)->resid = scsi_out(sc)->length;
1767                 scsi_in(sc)->resid = scsi_in(sc)->length;
1768         }
1769         sc->scsi_done(sc);
1770         return 0;
1771 }
1772 EXPORT_SYMBOL_GPL(iscsi_queuecommand);
1773
1774 int iscsi_target_alloc(struct scsi_target *starget)
1775 {
1776         struct iscsi_cls_session *cls_session = starget_to_session(starget);
1777         struct iscsi_session *session = cls_session->dd_data;
1778
1779         starget->can_queue = session->scsi_cmds_max;
1780         return 0;
1781 }
1782 EXPORT_SYMBOL_GPL(iscsi_target_alloc);
1783
1784 static void iscsi_tmf_timedout(unsigned long data)
1785 {
1786         struct iscsi_conn *conn = (struct iscsi_conn *)data;
1787         struct iscsi_session *session = conn->session;
1788
1789         spin_lock(&session->frwd_lock);
1790         if (conn->tmf_state == TMF_QUEUED) {
1791                 conn->tmf_state = TMF_TIMEDOUT;
1792                 ISCSI_DBG_EH(session, "tmf timedout\n");
1793                 /* unblock eh_abort() */
1794                 wake_up(&conn->ehwait);
1795         }
1796         spin_unlock(&session->frwd_lock);
1797 }
1798
1799 static int iscsi_exec_task_mgmt_fn(struct iscsi_conn *conn,
1800                                    struct iscsi_tm *hdr, int age,
1801                                    int timeout)
1802 {
1803         struct iscsi_session *session = conn->session;
1804         struct iscsi_task *task;
1805
1806         task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)hdr,
1807                                       NULL, 0);
1808         if (!task) {
1809                 spin_unlock_bh(&session->frwd_lock);
1810                 iscsi_conn_printk(KERN_ERR, conn, "Could not send TMF.\n");
1811                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1812                 spin_lock_bh(&session->frwd_lock);
1813                 return -EPERM;
1814         }
1815         conn->tmfcmd_pdus_cnt++;
1816         conn->tmf_timer.expires = timeout * HZ + jiffies;
1817         conn->tmf_timer.function = iscsi_tmf_timedout;
1818         conn->tmf_timer.data = (unsigned long)conn;
1819         add_timer(&conn->tmf_timer);
1820         ISCSI_DBG_EH(session, "tmf set timeout\n");
1821
1822         spin_unlock_bh(&session->frwd_lock);
1823         mutex_unlock(&session->eh_mutex);
1824
1825         /*
1826          * block eh thread until:
1827          *
1828          * 1) tmf response
1829          * 2) tmf timeout
1830          * 3) session is terminated or restarted or userspace has
1831          * given up on recovery
1832          */
1833         wait_event_interruptible(conn->ehwait, age != session->age ||
1834                                  session->state != ISCSI_STATE_LOGGED_IN ||
1835                                  conn->tmf_state != TMF_QUEUED);
1836         if (signal_pending(current))
1837                 flush_signals(current);
1838         del_timer_sync(&conn->tmf_timer);
1839
1840         mutex_lock(&session->eh_mutex);
1841         spin_lock_bh(&session->frwd_lock);
1842         /* if the session drops it will clean up the task */
1843         if (age != session->age ||
1844             session->state != ISCSI_STATE_LOGGED_IN)
1845                 return -ENOTCONN;
1846         return 0;
1847 }
1848
1849 /*
1850  * Fail commands. session lock held and recv side suspended and xmit
1851  * thread flushed
1852  */
1853 static void fail_scsi_tasks(struct iscsi_conn *conn, u64 lun, int error)
1854 {
1855         struct iscsi_task *task;
1856         int i;
1857
1858         for (i = 0; i < conn->session->cmds_max; i++) {
1859                 task = conn->session->cmds[i];
1860                 if (!task->sc || task->state == ISCSI_TASK_FREE)
1861                         continue;
1862
1863                 if (lun != -1 && lun != task->sc->device->lun)
1864                         continue;
1865
1866                 ISCSI_DBG_SESSION(conn->session,
1867                                   "failing sc %p itt 0x%x state %d\n",
1868                                   task->sc, task->itt, task->state);
1869                 fail_scsi_task(task, error);
1870         }
1871 }
1872
1873 /**
1874  * iscsi_suspend_queue - suspend iscsi_queuecommand
1875  * @conn: iscsi conn to stop queueing IO on
1876  *
1877  * This grabs the session frwd_lock to make sure no one is in
1878  * xmit_task/queuecommand, and then sets suspend to prevent
1879  * new commands from being queued. This only needs to be called
1880  * by offload drivers that need to sync a path like ep disconnect
1881  * with the iscsi_queuecommand/xmit_task. To start IO again libiscsi
1882  * will call iscsi_start_tx and iscsi_unblock_session when in FFP.
1883  */
1884 void iscsi_suspend_queue(struct iscsi_conn *conn)
1885 {
1886         spin_lock_bh(&conn->session->frwd_lock);
1887         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1888         spin_unlock_bh(&conn->session->frwd_lock);
1889 }
1890 EXPORT_SYMBOL_GPL(iscsi_suspend_queue);
1891
1892 /**
1893  * iscsi_suspend_tx - suspend iscsi_data_xmit
1894  * @conn: iscsi conn tp stop processing IO on.
1895  *
1896  * This function sets the suspend bit to prevent iscsi_data_xmit
1897  * from sending new IO, and if work is queued on the xmit thread
1898  * it will wait for it to be completed.
1899  */
1900 void iscsi_suspend_tx(struct iscsi_conn *conn)
1901 {
1902         struct Scsi_Host *shost = conn->session->host;
1903         struct iscsi_host *ihost = shost_priv(shost);
1904
1905         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1906         if (ihost->workq)
1907                 flush_workqueue(ihost->workq);
1908 }
1909 EXPORT_SYMBOL_GPL(iscsi_suspend_tx);
1910
1911 static void iscsi_start_tx(struct iscsi_conn *conn)
1912 {
1913         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1914         iscsi_conn_queue_work(conn);
1915 }
1916
1917 /*
1918  * We want to make sure a ping is in flight. It has timed out.
1919  * And we are not busy processing a pdu that is making
1920  * progress but got started before the ping and is taking a while
1921  * to complete so the ping is just stuck behind it in a queue.
1922  */
1923 static int iscsi_has_ping_timed_out(struct iscsi_conn *conn)
1924 {
1925         if (conn->ping_task &&
1926             time_before_eq(conn->last_recv + (conn->recv_timeout * HZ) +
1927                            (conn->ping_timeout * HZ), jiffies))
1928                 return 1;
1929         else
1930                 return 0;
1931 }
1932
1933 static enum blk_eh_timer_return iscsi_eh_cmd_timed_out(struct scsi_cmnd *sc)
1934 {
1935         enum blk_eh_timer_return rc = BLK_EH_NOT_HANDLED;
1936         struct iscsi_task *task = NULL, *running_task;
1937         struct iscsi_cls_session *cls_session;
1938         struct iscsi_session *session;
1939         struct iscsi_conn *conn;
1940         int i;
1941
1942         cls_session = starget_to_session(scsi_target(sc->device));
1943         session = cls_session->dd_data;
1944
1945         ISCSI_DBG_EH(session, "scsi cmd %p timedout\n", sc);
1946
1947         spin_lock(&session->frwd_lock);
1948         task = (struct iscsi_task *)sc->SCp.ptr;
1949         if (!task) {
1950                 /*
1951                  * Raced with completion. Blk layer has taken ownership
1952                  * so let timeout code complete it now.
1953                  */
1954                 rc = BLK_EH_HANDLED;
1955                 goto done;
1956         }
1957
1958         if (session->state != ISCSI_STATE_LOGGED_IN) {
1959                 /*
1960                  * We are probably in the middle of iscsi recovery so let
1961                  * that complete and handle the error.
1962                  */
1963                 rc = BLK_EH_RESET_TIMER;
1964                 goto done;
1965         }
1966
1967         conn = session->leadconn;
1968         if (!conn) {
1969                 /* In the middle of shuting down */
1970                 rc = BLK_EH_RESET_TIMER;
1971                 goto done;
1972         }
1973
1974         /*
1975          * If we have sent (at least queued to the network layer) a pdu or
1976          * recvd one for the task since the last timeout ask for
1977          * more time. If on the next timeout we have not made progress
1978          * we can check if it is the task or connection when we send the
1979          * nop as a ping.
1980          */
1981         if (time_after(task->last_xfer, task->last_timeout)) {
1982                 ISCSI_DBG_EH(session, "Command making progress. Asking "
1983                              "scsi-ml for more time to complete. "
1984                              "Last data xfer at %lu. Last timeout was at "
1985                              "%lu\n.", task->last_xfer, task->last_timeout);
1986                 task->have_checked_conn = false;
1987                 rc = BLK_EH_RESET_TIMER;
1988                 goto done;
1989         }
1990
1991         if (!conn->recv_timeout && !conn->ping_timeout)
1992                 goto done;
1993         /*
1994          * if the ping timedout then we are in the middle of cleaning up
1995          * and can let the iscsi eh handle it
1996          */
1997         if (iscsi_has_ping_timed_out(conn)) {
1998                 rc = BLK_EH_RESET_TIMER;
1999                 goto done;
2000         }
2001
2002         for (i = 0; i < conn->session->cmds_max; i++) {
2003                 running_task = conn->session->cmds[i];
2004                 if (!running_task->sc || running_task == task ||
2005                      running_task->state != ISCSI_TASK_RUNNING)
2006                         continue;
2007
2008                 /*
2009                  * Only check if cmds started before this one have made
2010                  * progress, or this could never fail
2011                  */
2012                 if (time_after(running_task->sc->jiffies_at_alloc,
2013                                task->sc->jiffies_at_alloc))
2014                         continue;
2015
2016                 if (time_after(running_task->last_xfer, task->last_timeout)) {
2017                         /*
2018                          * This task has not made progress, but a task
2019                          * started before us has transferred data since
2020                          * we started/last-checked. We could be queueing
2021                          * too many tasks or the LU is bad.
2022                          *
2023                          * If the device is bad the cmds ahead of us on
2024                          * other devs will complete, and this loop will
2025                          * eventually fail starting the scsi eh.
2026                          */
2027                         ISCSI_DBG_EH(session, "Command has not made progress "
2028                                      "but commands ahead of it have. "
2029                                      "Asking scsi-ml for more time to "
2030                                      "complete. Our last xfer vs running task "
2031                                      "last xfer %lu/%lu. Last check %lu.\n",
2032                                      task->last_xfer, running_task->last_xfer,
2033                                      task->last_timeout);
2034                         rc = BLK_EH_RESET_TIMER;
2035                         goto done;
2036                 }
2037         }
2038
2039         /* Assumes nop timeout is shorter than scsi cmd timeout */
2040         if (task->have_checked_conn)
2041                 goto done;
2042
2043         /*
2044          * Checking the transport already or nop from a cmd timeout still
2045          * running
2046          */
2047         if (conn->ping_task) {
2048                 task->have_checked_conn = true;
2049                 rc = BLK_EH_RESET_TIMER;
2050                 goto done;
2051         }
2052
2053         /* Make sure there is a transport check done */
2054         iscsi_send_nopout(conn, NULL);
2055         task->have_checked_conn = true;
2056         rc = BLK_EH_RESET_TIMER;
2057
2058 done:
2059         if (task)
2060                 task->last_timeout = jiffies;
2061         spin_unlock(&session->frwd_lock);
2062         ISCSI_DBG_EH(session, "return %s\n", rc == BLK_EH_RESET_TIMER ?
2063                      "timer reset" : "nh");
2064         return rc;
2065 }
2066
2067 static void iscsi_check_transport_timeouts(unsigned long data)
2068 {
2069         struct iscsi_conn *conn = (struct iscsi_conn *)data;
2070         struct iscsi_session *session = conn->session;
2071         unsigned long recv_timeout, next_timeout = 0, last_recv;
2072
2073         spin_lock(&session->frwd_lock);
2074         if (session->state != ISCSI_STATE_LOGGED_IN)
2075                 goto done;
2076
2077         recv_timeout = conn->recv_timeout;
2078         if (!recv_timeout)
2079                 goto done;
2080
2081         recv_timeout *= HZ;
2082         last_recv = conn->last_recv;
2083
2084         if (iscsi_has_ping_timed_out(conn)) {
2085                 iscsi_conn_printk(KERN_ERR, conn, "ping timeout of %d secs "
2086                                   "expired, recv timeout %d, last rx %lu, "
2087                                   "last ping %lu, now %lu\n",
2088                                   conn->ping_timeout, conn->recv_timeout,
2089                                   last_recv, conn->last_ping, jiffies);
2090                 spin_unlock(&session->frwd_lock);
2091                 iscsi_conn_failure(conn, ISCSI_ERR_NOP_TIMEDOUT);
2092                 return;
2093         }
2094
2095         if (time_before_eq(last_recv + recv_timeout, jiffies)) {
2096                 /* send a ping to try to provoke some traffic */
2097                 ISCSI_DBG_CONN(conn, "Sending nopout as ping\n");
2098                 if (iscsi_send_nopout(conn, NULL))
2099                         next_timeout = jiffies + (1 * HZ);
2100                 else
2101                         next_timeout = conn->last_ping + (conn->ping_timeout * HZ);
2102         } else
2103                 next_timeout = last_recv + recv_timeout;
2104
2105         ISCSI_DBG_CONN(conn, "Setting next tmo %lu\n", next_timeout);
2106         mod_timer(&conn->transport_timer, next_timeout);
2107 done:
2108         spin_unlock(&session->frwd_lock);
2109 }
2110
2111 static void iscsi_prep_abort_task_pdu(struct iscsi_task *task,
2112                                       struct iscsi_tm *hdr)
2113 {
2114         memset(hdr, 0, sizeof(*hdr));
2115         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2116         hdr->flags = ISCSI_TM_FUNC_ABORT_TASK & ISCSI_FLAG_TM_FUNC_MASK;
2117         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2118         hdr->lun = task->lun;
2119         hdr->rtt = task->hdr_itt;
2120         hdr->refcmdsn = task->cmdsn;
2121 }
2122
2123 int iscsi_eh_abort(struct scsi_cmnd *sc)
2124 {
2125         struct iscsi_cls_session *cls_session;
2126         struct iscsi_session *session;
2127         struct iscsi_conn *conn;
2128         struct iscsi_task *task;
2129         struct iscsi_tm *hdr;
2130         int rc, age;
2131
2132         cls_session = starget_to_session(scsi_target(sc->device));
2133         session = cls_session->dd_data;
2134
2135         ISCSI_DBG_EH(session, "aborting sc %p\n", sc);
2136
2137         mutex_lock(&session->eh_mutex);
2138         spin_lock_bh(&session->frwd_lock);
2139         /*
2140          * if session was ISCSI_STATE_IN_RECOVERY then we may not have
2141          * got the command.
2142          */
2143         if (!sc->SCp.ptr) {
2144                 ISCSI_DBG_EH(session, "sc never reached iscsi layer or "
2145                                       "it completed.\n");
2146                 spin_unlock_bh(&session->frwd_lock);
2147                 mutex_unlock(&session->eh_mutex);
2148                 return SUCCESS;
2149         }
2150
2151         /*
2152          * If we are not logged in or we have started a new session
2153          * then let the host reset code handle this
2154          */
2155         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN ||
2156             sc->SCp.phase != session->age) {
2157                 spin_unlock_bh(&session->frwd_lock);
2158                 mutex_unlock(&session->eh_mutex);
2159                 ISCSI_DBG_EH(session, "failing abort due to dropped "
2160                                   "session.\n");
2161                 return FAILED;
2162         }
2163
2164         conn = session->leadconn;
2165         conn->eh_abort_cnt++;
2166         age = session->age;
2167
2168         task = (struct iscsi_task *)sc->SCp.ptr;
2169         ISCSI_DBG_EH(session, "aborting [sc %p itt 0x%x]\n",
2170                      sc, task->itt);
2171
2172         /* task completed before time out */
2173         if (!task->sc) {
2174                 ISCSI_DBG_EH(session, "sc completed while abort in progress\n");
2175                 goto success;
2176         }
2177
2178         if (task->state == ISCSI_TASK_PENDING) {
2179                 fail_scsi_task(task, DID_ABORT);
2180                 goto success;
2181         }
2182
2183         /* only have one tmf outstanding at a time */
2184         if (conn->tmf_state != TMF_INITIAL)
2185                 goto failed;
2186         conn->tmf_state = TMF_QUEUED;
2187
2188         hdr = &conn->tmhdr;
2189         iscsi_prep_abort_task_pdu(task, hdr);
2190
2191         if (iscsi_exec_task_mgmt_fn(conn, hdr, age, session->abort_timeout)) {
2192                 rc = FAILED;
2193                 goto failed;
2194         }
2195
2196         switch (conn->tmf_state) {
2197         case TMF_SUCCESS:
2198                 spin_unlock_bh(&session->frwd_lock);
2199                 /*
2200                  * stop tx side incase the target had sent a abort rsp but
2201                  * the initiator was still writing out data.
2202                  */
2203                 iscsi_suspend_tx(conn);
2204                 /*
2205                  * we do not stop the recv side because targets have been
2206                  * good and have never sent us a successful tmf response
2207                  * then sent more data for the cmd.
2208                  */
2209                 spin_lock_bh(&session->frwd_lock);
2210                 fail_scsi_task(task, DID_ABORT);
2211                 conn->tmf_state = TMF_INITIAL;
2212                 memset(hdr, 0, sizeof(*hdr));
2213                 spin_unlock_bh(&session->frwd_lock);
2214                 iscsi_start_tx(conn);
2215                 goto success_unlocked;
2216         case TMF_TIMEDOUT:
2217                 spin_unlock_bh(&session->frwd_lock);
2218                 iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2219                 goto failed_unlocked;
2220         case TMF_NOT_FOUND:
2221                 if (!sc->SCp.ptr) {
2222                         conn->tmf_state = TMF_INITIAL;
2223                         memset(hdr, 0, sizeof(*hdr));
2224                         /* task completed before tmf abort response */
2225                         ISCSI_DBG_EH(session, "sc completed while abort in "
2226                                               "progress\n");
2227                         goto success;
2228                 }
2229                 /* fall through */
2230         default:
2231                 conn->tmf_state = TMF_INITIAL;
2232                 goto failed;
2233         }
2234
2235 success:
2236         spin_unlock_bh(&session->frwd_lock);
2237 success_unlocked:
2238         ISCSI_DBG_EH(session, "abort success [sc %p itt 0x%x]\n",
2239                      sc, task->itt);
2240         mutex_unlock(&session->eh_mutex);
2241         return SUCCESS;
2242
2243 failed:
2244         spin_unlock_bh(&session->frwd_lock);
2245 failed_unlocked:
2246         ISCSI_DBG_EH(session, "abort failed [sc %p itt 0x%x]\n", sc,
2247                      task ? task->itt : 0);
2248         mutex_unlock(&session->eh_mutex);
2249         return FAILED;
2250 }
2251 EXPORT_SYMBOL_GPL(iscsi_eh_abort);
2252
2253 static void iscsi_prep_lun_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
2254 {
2255         memset(hdr, 0, sizeof(*hdr));
2256         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2257         hdr->flags = ISCSI_TM_FUNC_LOGICAL_UNIT_RESET & ISCSI_FLAG_TM_FUNC_MASK;
2258         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2259         int_to_scsilun(sc->device->lun, &hdr->lun);
2260         hdr->rtt = RESERVED_ITT;
2261 }
2262
2263 int iscsi_eh_device_reset(struct scsi_cmnd *sc)
2264 {
2265         struct iscsi_cls_session *cls_session;
2266         struct iscsi_session *session;
2267         struct iscsi_conn *conn;
2268         struct iscsi_tm *hdr;
2269         int rc = FAILED;
2270
2271         cls_session = starget_to_session(scsi_target(sc->device));
2272         session = cls_session->dd_data;
2273
2274         ISCSI_DBG_EH(session, "LU Reset [sc %p lun %llu]\n", sc,
2275                      sc->device->lun);
2276
2277         mutex_lock(&session->eh_mutex);
2278         spin_lock_bh(&session->frwd_lock);
2279         /*
2280          * Just check if we are not logged in. We cannot check for
2281          * the phase because the reset could come from a ioctl.
2282          */
2283         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
2284                 goto unlock;
2285         conn = session->leadconn;
2286
2287         /* only have one tmf outstanding at a time */
2288         if (conn->tmf_state != TMF_INITIAL)
2289                 goto unlock;
2290         conn->tmf_state = TMF_QUEUED;
2291
2292         hdr = &conn->tmhdr;
2293         iscsi_prep_lun_reset_pdu(sc, hdr);
2294
2295         if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
2296                                     session->lu_reset_timeout)) {
2297                 rc = FAILED;
2298                 goto unlock;
2299         }
2300
2301         switch (conn->tmf_state) {
2302         case TMF_SUCCESS:
2303                 break;
2304         case TMF_TIMEDOUT:
2305                 spin_unlock_bh(&session->frwd_lock);
2306                 iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2307                 goto done;
2308         default:
2309                 conn->tmf_state = TMF_INITIAL;
2310                 goto unlock;
2311         }
2312
2313         rc = SUCCESS;
2314         spin_unlock_bh(&session->frwd_lock);
2315
2316         iscsi_suspend_tx(conn);
2317
2318         spin_lock_bh(&session->frwd_lock);
2319         memset(hdr, 0, sizeof(*hdr));
2320         fail_scsi_tasks(conn, sc->device->lun, DID_ERROR);
2321         conn->tmf_state = TMF_INITIAL;
2322         spin_unlock_bh(&session->frwd_lock);
2323
2324         iscsi_start_tx(conn);
2325         goto done;
2326
2327 unlock:
2328         spin_unlock_bh(&session->frwd_lock);
2329 done:
2330         ISCSI_DBG_EH(session, "dev reset result = %s\n",
2331                      rc == SUCCESS ? "SUCCESS" : "FAILED");
2332         mutex_unlock(&session->eh_mutex);
2333         return rc;
2334 }
2335 EXPORT_SYMBOL_GPL(iscsi_eh_device_reset);
2336
2337 void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
2338 {
2339         struct iscsi_session *session = cls_session->dd_data;
2340
2341         spin_lock_bh(&session->frwd_lock);
2342         if (session->state != ISCSI_STATE_LOGGED_IN) {
2343                 session->state = ISCSI_STATE_RECOVERY_FAILED;
2344                 if (session->leadconn)
2345                         wake_up(&session->leadconn->ehwait);
2346         }
2347         spin_unlock_bh(&session->frwd_lock);
2348 }
2349 EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
2350
2351 /**
2352  * iscsi_eh_session_reset - drop session and attempt relogin
2353  * @sc: scsi command
2354  *
2355  * This function will wait for a relogin, session termination from
2356  * userspace, or a recovery/replacement timeout.
2357  */
2358 int iscsi_eh_session_reset(struct scsi_cmnd *sc)
2359 {
2360         struct iscsi_cls_session *cls_session;
2361         struct iscsi_session *session;
2362         struct iscsi_conn *conn;
2363
2364         cls_session = starget_to_session(scsi_target(sc->device));
2365         session = cls_session->dd_data;
2366         conn = session->leadconn;
2367
2368         mutex_lock(&session->eh_mutex);
2369         spin_lock_bh(&session->frwd_lock);
2370         if (session->state == ISCSI_STATE_TERMINATE) {
2371 failed:
2372                 ISCSI_DBG_EH(session,
2373                              "failing session reset: Could not log back into "
2374                              "%s, %s [age %d]\n", session->targetname,
2375                              conn->persistent_address, session->age);
2376                 spin_unlock_bh(&session->frwd_lock);
2377                 mutex_unlock(&session->eh_mutex);
2378                 return FAILED;
2379         }
2380
2381         spin_unlock_bh(&session->frwd_lock);
2382         mutex_unlock(&session->eh_mutex);
2383         /*
2384          * we drop the lock here but the leadconn cannot be destoyed while
2385          * we are in the scsi eh
2386          */
2387         iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2388
2389         ISCSI_DBG_EH(session, "wait for relogin\n");
2390         wait_event_interruptible(conn->ehwait,
2391                                  session->state == ISCSI_STATE_TERMINATE ||
2392                                  session->state == ISCSI_STATE_LOGGED_IN ||
2393                                  session->state == ISCSI_STATE_RECOVERY_FAILED);
2394         if (signal_pending(current))
2395                 flush_signals(current);
2396
2397         mutex_lock(&session->eh_mutex);
2398         spin_lock_bh(&session->frwd_lock);
2399         if (session->state == ISCSI_STATE_LOGGED_IN) {
2400                 ISCSI_DBG_EH(session,
2401                              "session reset succeeded for %s,%s\n",
2402                              session->targetname, conn->persistent_address);
2403         } else
2404                 goto failed;
2405         spin_unlock_bh(&session->frwd_lock);
2406         mutex_unlock(&session->eh_mutex);
2407         return SUCCESS;
2408 }
2409 EXPORT_SYMBOL_GPL(iscsi_eh_session_reset);
2410
2411 static void iscsi_prep_tgt_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
2412 {
2413         memset(hdr, 0, sizeof(*hdr));
2414         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2415         hdr->flags = ISCSI_TM_FUNC_TARGET_WARM_RESET & ISCSI_FLAG_TM_FUNC_MASK;
2416         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2417         hdr->rtt = RESERVED_ITT;
2418 }
2419
2420 /**
2421  * iscsi_eh_target_reset - reset target
2422  * @sc: scsi command
2423  *
2424  * This will attempt to send a warm target reset.
2425  */
2426 int iscsi_eh_target_reset(struct scsi_cmnd *sc)
2427 {
2428         struct iscsi_cls_session *cls_session;
2429         struct iscsi_session *session;
2430         struct iscsi_conn *conn;
2431         struct iscsi_tm *hdr;
2432         int rc = FAILED;
2433
2434         cls_session = starget_to_session(scsi_target(sc->device));
2435         session = cls_session->dd_data;
2436
2437         ISCSI_DBG_EH(session, "tgt Reset [sc %p tgt %s]\n", sc,
2438                      session->targetname);
2439
2440         mutex_lock(&session->eh_mutex);
2441         spin_lock_bh(&session->frwd_lock);
2442         /*
2443          * Just check if we are not logged in. We cannot check for
2444          * the phase because the reset could come from a ioctl.
2445          */
2446         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
2447                 goto unlock;
2448         conn = session->leadconn;
2449
2450         /* only have one tmf outstanding at a time */
2451         if (conn->tmf_state != TMF_INITIAL)
2452                 goto unlock;
2453         conn->tmf_state = TMF_QUEUED;
2454
2455         hdr = &conn->tmhdr;
2456         iscsi_prep_tgt_reset_pdu(sc, hdr);
2457
2458         if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
2459                                     session->tgt_reset_timeout)) {
2460                 rc = FAILED;
2461                 goto unlock;
2462         }
2463
2464         switch (conn->tmf_state) {
2465         case TMF_SUCCESS:
2466                 break;
2467         case TMF_TIMEDOUT:
2468                 spin_unlock_bh(&session->frwd_lock);
2469                 iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2470                 goto done;
2471         default:
2472                 conn->tmf_state = TMF_INITIAL;
2473                 goto unlock;
2474         }
2475
2476         rc = SUCCESS;
2477         spin_unlock_bh(&session->frwd_lock);
2478
2479         iscsi_suspend_tx(conn);
2480
2481         spin_lock_bh(&session->frwd_lock);
2482         memset(hdr, 0, sizeof(*hdr));
2483         fail_scsi_tasks(conn, -1, DID_ERROR);
2484         conn->tmf_state = TMF_INITIAL;
2485         spin_unlock_bh(&session->frwd_lock);
2486
2487         iscsi_start_tx(conn);
2488         goto done;
2489
2490 unlock:
2491         spin_unlock_bh(&session->frwd_lock);
2492 done:
2493         ISCSI_DBG_EH(session, "tgt %s reset result = %s\n", session->targetname,
2494                      rc == SUCCESS ? "SUCCESS" : "FAILED");
2495         mutex_unlock(&session->eh_mutex);
2496         return rc;
2497 }
2498 EXPORT_SYMBOL_GPL(iscsi_eh_target_reset);
2499
2500 /**
2501  * iscsi_eh_recover_target - reset target and possibly the session
2502  * @sc: scsi command
2503  *
2504  * This will attempt to send a warm target reset. If that fails,
2505  * we will escalate to ERL0 session recovery.
2506  */
2507 int iscsi_eh_recover_target(struct scsi_cmnd *sc)
2508 {
2509         int rc;
2510
2511         rc = iscsi_eh_target_reset(sc);
2512         if (rc == FAILED)
2513                 rc = iscsi_eh_session_reset(sc);
2514         return rc;
2515 }
2516 EXPORT_SYMBOL_GPL(iscsi_eh_recover_target);
2517
2518 /*
2519  * Pre-allocate a pool of @max items of @item_size. By default, the pool
2520  * should be accessed via kfifo_{get,put} on q->queue.
2521  * Optionally, the caller can obtain the array of object pointers
2522  * by passing in a non-NULL @items pointer
2523  */
2524 int
2525 iscsi_pool_init(struct iscsi_pool *q, int max, void ***items, int item_size)
2526 {
2527         int i, num_arrays = 1;
2528
2529         memset(q, 0, sizeof(*q));
2530
2531         q->max = max;
2532
2533         /* If the user passed an items pointer, he wants a copy of
2534          * the array. */
2535         if (items)
2536                 num_arrays++;
2537         q->pool = kzalloc(num_arrays * max * sizeof(void*), GFP_KERNEL);
2538         if (q->pool == NULL)
2539                 return -ENOMEM;
2540
2541         kfifo_init(&q->queue, (void*)q->pool, max * sizeof(void*));
2542
2543         for (i = 0; i < max; i++) {
2544                 q->pool[i] = kzalloc(item_size, GFP_KERNEL);
2545                 if (q->pool[i] == NULL) {
2546                         q->max = i;
2547                         goto enomem;
2548                 }
2549                 kfifo_in(&q->queue, (void*)&q->pool[i], sizeof(void*));
2550         }
2551
2552         if (items) {
2553                 *items = q->pool + max;
2554                 memcpy(*items, q->pool, max * sizeof(void *));
2555         }
2556
2557         return 0;
2558
2559 enomem:
2560         iscsi_pool_free(q);
2561         return -ENOMEM;
2562 }
2563 EXPORT_SYMBOL_GPL(iscsi_pool_init);
2564
2565 void iscsi_pool_free(struct iscsi_pool *q)
2566 {
2567         int i;
2568
2569         for (i = 0; i < q->max; i++)
2570                 kfree(q->pool[i]);
2571         kfree(q->pool);
2572 }
2573 EXPORT_SYMBOL_GPL(iscsi_pool_free);
2574
2575 /**
2576  * iscsi_host_add - add host to system
2577  * @shost: scsi host
2578  * @pdev: parent device
2579  *
2580  * This should be called by partial offload and software iscsi drivers
2581  * to add a host to the system.
2582  */
2583 int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev)
2584 {
2585         if (!shost->can_queue)
2586                 shost->can_queue = ISCSI_DEF_XMIT_CMDS_MAX;
2587
2588         if (!shost->cmd_per_lun)
2589                 shost->cmd_per_lun = ISCSI_DEF_CMD_PER_LUN;
2590
2591         if (!shost->transportt->eh_timed_out)
2592                 shost->transportt->eh_timed_out = iscsi_eh_cmd_timed_out;
2593         return scsi_add_host(shost, pdev);
2594 }
2595 EXPORT_SYMBOL_GPL(iscsi_host_add);
2596
2597 /**
2598  * iscsi_host_alloc - allocate a host and driver data
2599  * @sht: scsi host template
2600  * @dd_data_size: driver host data size
2601  * @xmit_can_sleep: bool indicating if LLD will queue IO from a work queue
2602  *
2603  * This should be called by partial offload and software iscsi drivers.
2604  * To access the driver specific memory use the iscsi_host_priv() macro.
2605  */
2606 struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
2607                                    int dd_data_size, bool xmit_can_sleep)
2608 {
2609         struct Scsi_Host *shost;
2610         struct iscsi_host *ihost;
2611
2612         shost = scsi_host_alloc(sht, sizeof(struct iscsi_host) + dd_data_size);
2613         if (!shost)
2614                 return NULL;
2615         ihost = shost_priv(shost);
2616
2617         if (xmit_can_sleep) {
2618                 snprintf(ihost->workq_name, sizeof(ihost->workq_name),
2619                         "iscsi_q_%d", shost->host_no);
2620                 ihost->workq = create_singlethread_workqueue(ihost->workq_name);
2621                 if (!ihost->workq)
2622                         goto free_host;
2623         }
2624
2625         spin_lock_init(&ihost->lock);
2626         ihost->state = ISCSI_HOST_SETUP;
2627         ihost->num_sessions = 0;
2628         init_waitqueue_head(&ihost->session_removal_wq);
2629         return shost;
2630
2631 free_host:
2632         scsi_host_put(shost);
2633         return NULL;
2634 }
2635 EXPORT_SYMBOL_GPL(iscsi_host_alloc);
2636
2637 static void iscsi_notify_host_removed(struct iscsi_cls_session *cls_session)
2638 {
2639         iscsi_session_failure(cls_session->dd_data, ISCSI_ERR_INVALID_HOST);
2640 }
2641
2642 /**
2643  * iscsi_host_remove - remove host and sessions
2644  * @shost: scsi host
2645  *
2646  * If there are any sessions left, this will initiate the removal and wait
2647  * for the completion.
2648  */
2649 void iscsi_host_remove(struct Scsi_Host *shost)
2650 {
2651         struct iscsi_host *ihost = shost_priv(shost);
2652         unsigned long flags;
2653
2654         spin_lock_irqsave(&ihost->lock, flags);
2655         ihost->state = ISCSI_HOST_REMOVED;
2656         spin_unlock_irqrestore(&ihost->lock, flags);
2657
2658         iscsi_host_for_each_session(shost, iscsi_notify_host_removed);
2659         wait_event_interruptible(ihost->session_removal_wq,
2660                                  ihost->num_sessions == 0);
2661         if (signal_pending(current))
2662                 flush_signals(current);
2663
2664         scsi_remove_host(shost);
2665         if (ihost->workq)
2666                 destroy_workqueue(ihost->workq);
2667 }
2668 EXPORT_SYMBOL_GPL(iscsi_host_remove);
2669
2670 void iscsi_host_free(struct Scsi_Host *shost)
2671 {
2672         struct iscsi_host *ihost = shost_priv(shost);
2673
2674         kfree(ihost->netdev);
2675         kfree(ihost->hwaddress);
2676         kfree(ihost->initiatorname);
2677         scsi_host_put(shost);
2678 }
2679 EXPORT_SYMBOL_GPL(iscsi_host_free);
2680
2681 static void iscsi_host_dec_session_cnt(struct Scsi_Host *shost)
2682 {
2683         struct iscsi_host *ihost = shost_priv(shost);
2684         unsigned long flags;
2685
2686         shost = scsi_host_get(shost);
2687         if (!shost) {
2688                 printk(KERN_ERR "Invalid state. Cannot notify host removal "
2689                       "of session teardown event because host already "
2690                       "removed.\n");
2691                 return;
2692         }
2693
2694         spin_lock_irqsave(&ihost->lock, flags);
2695         ihost->num_sessions--;
2696         if (ihost->num_sessions == 0)
2697                 wake_up(&ihost->session_removal_wq);
2698         spin_unlock_irqrestore(&ihost->lock, flags);
2699         scsi_host_put(shost);
2700 }
2701
2702 /**
2703  * iscsi_session_setup - create iscsi cls session and host and session
2704  * @iscsit: iscsi transport template
2705  * @shost: scsi host
2706  * @cmds_max: session can queue
2707  * @cmd_task_size: LLD task private data size
2708  * @initial_cmdsn: initial CmdSN
2709  *
2710  * This can be used by software iscsi_transports that allocate
2711  * a session per scsi host.
2712  *
2713  * Callers should set cmds_max to the largest total numer (mgmt + scsi) of
2714  * tasks they support. The iscsi layer reserves ISCSI_MGMT_CMDS_MAX tasks
2715  * for nop handling and login/logout requests.
2716  */
2717 struct iscsi_cls_session *
2718 iscsi_session_setup(struct iscsi_transport *iscsit, struct Scsi_Host *shost,
2719                     uint16_t cmds_max, int dd_size, int cmd_task_size,
2720                     uint32_t initial_cmdsn, unsigned int id)
2721 {
2722         struct iscsi_host *ihost = shost_priv(shost);
2723         struct iscsi_session *session;
2724         struct iscsi_cls_session *cls_session;
2725         int cmd_i, scsi_cmds, total_cmds = cmds_max;
2726         unsigned long flags;
2727
2728         spin_lock_irqsave(&ihost->lock, flags);
2729         if (ihost->state == ISCSI_HOST_REMOVED) {
2730                 spin_unlock_irqrestore(&ihost->lock, flags);
2731                 return NULL;
2732         }
2733         ihost->num_sessions++;
2734         spin_unlock_irqrestore(&ihost->lock, flags);
2735
2736         if (!total_cmds)
2737                 total_cmds = ISCSI_DEF_XMIT_CMDS_MAX;
2738         /*
2739          * The iscsi layer needs some tasks for nop handling and tmfs,
2740          * so the cmds_max must at least be greater than ISCSI_MGMT_CMDS_MAX
2741          * + 1 command for scsi IO.
2742          */
2743         if (total_cmds < ISCSI_TOTAL_CMDS_MIN) {
2744                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2745                        "must be a power of two that is at least %d.\n",
2746                        total_cmds, ISCSI_TOTAL_CMDS_MIN);
2747                 goto dec_session_count;
2748         }
2749
2750         if (total_cmds > ISCSI_TOTAL_CMDS_MAX) {
2751                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2752                        "must be a power of 2 less than or equal to %d.\n",
2753                        cmds_max, ISCSI_TOTAL_CMDS_MAX);
2754                 total_cmds = ISCSI_TOTAL_CMDS_MAX;
2755         }
2756
2757         if (!is_power_of_2(total_cmds)) {
2758                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2759                        "must be a power of 2.\n", total_cmds);
2760                 total_cmds = rounddown_pow_of_two(total_cmds);
2761                 if (total_cmds < ISCSI_TOTAL_CMDS_MIN)
2762                         return NULL;
2763                 printk(KERN_INFO "iscsi: Rounding can_queue to %d.\n",
2764                        total_cmds);
2765         }
2766         scsi_cmds = total_cmds - ISCSI_MGMT_CMDS_MAX;
2767
2768         cls_session = iscsi_alloc_session(shost, iscsit,
2769                                           sizeof(struct iscsi_session) +
2770                                           dd_size);
2771         if (!cls_session)
2772                 goto dec_session_count;
2773         session = cls_session->dd_data;
2774         session->cls_session = cls_session;
2775         session->host = shost;
2776         session->state = ISCSI_STATE_FREE;
2777         session->fast_abort = 1;
2778         session->tgt_reset_timeout = 30;
2779         session->lu_reset_timeout = 15;
2780         session->abort_timeout = 10;
2781         session->scsi_cmds_max = scsi_cmds;
2782         session->cmds_max = total_cmds;
2783         session->queued_cmdsn = session->cmdsn = initial_cmdsn;
2784         session->exp_cmdsn = initial_cmdsn + 1;
2785         session->max_cmdsn = initial_cmdsn + 1;
2786         session->max_r2t = 1;
2787         session->tt = iscsit;
2788         session->dd_data = cls_session->dd_data + sizeof(*session);
2789
2790         mutex_init(&session->eh_mutex);
2791         spin_lock_init(&session->frwd_lock);
2792         spin_lock_init(&session->back_lock);
2793
2794         /* initialize SCSI PDU commands pool */
2795         if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
2796                             (void***)&session->cmds,
2797                             cmd_task_size + sizeof(struct iscsi_task)))
2798                 goto cmdpool_alloc_fail;
2799
2800         /* pre-format cmds pool with ITT */
2801         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
2802                 struct iscsi_task *task = session->cmds[cmd_i];
2803
2804                 if (cmd_task_size)
2805                         task->dd_data = &task[1];
2806                 task->itt = cmd_i;
2807                 task->state = ISCSI_TASK_FREE;
2808                 INIT_LIST_HEAD(&task->running);
2809         }
2810
2811         if (!try_module_get(iscsit->owner))
2812                 goto module_get_fail;
2813
2814         if (iscsi_add_session(cls_session, id))
2815                 goto cls_session_fail;
2816
2817         return cls_session;
2818
2819 cls_session_fail:
2820         module_put(iscsit->owner);
2821 module_get_fail:
2822         iscsi_pool_free(&session->cmdpool);
2823 cmdpool_alloc_fail:
2824         iscsi_free_session(cls_session);
2825 dec_session_count:
2826         iscsi_host_dec_session_cnt(shost);
2827         return NULL;
2828 }
2829 EXPORT_SYMBOL_GPL(iscsi_session_setup);
2830
2831 /**
2832  * iscsi_session_teardown - destroy session, host, and cls_session
2833  * @cls_session: iscsi session
2834  *
2835  * The driver must have called iscsi_remove_session before
2836  * calling this.
2837  */
2838 void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
2839 {
2840         struct iscsi_session *session = cls_session->dd_data;
2841         struct module *owner = cls_session->transport->owner;
2842         struct Scsi_Host *shost = session->host;
2843
2844         iscsi_pool_free(&session->cmdpool);
2845
2846         kfree(session->password);
2847         kfree(session->password_in);
2848         kfree(session->username);
2849         kfree(session->username_in);
2850         kfree(session->targetname);
2851         kfree(session->targetalias);
2852         kfree(session->initiatorname);
2853         kfree(session->boot_root);
2854         kfree(session->boot_nic);
2855         kfree(session->boot_target);
2856         kfree(session->ifacename);
2857         kfree(session->portal_type);
2858         kfree(session->discovery_parent_type);
2859
2860         iscsi_destroy_session(cls_session);
2861         iscsi_host_dec_session_cnt(shost);
2862         module_put(owner);
2863 }
2864 EXPORT_SYMBOL_GPL(iscsi_session_teardown);
2865
2866 /**
2867  * iscsi_conn_setup - create iscsi_cls_conn and iscsi_conn
2868  * @cls_session: iscsi_cls_session
2869  * @dd_size: private driver data size
2870  * @conn_idx: cid
2871  */
2872 struct iscsi_cls_conn *
2873 iscsi_conn_setup(struct iscsi_cls_session *cls_session, int dd_size,
2874                  uint32_t conn_idx)
2875 {
2876         struct iscsi_session *session = cls_session->dd_data;
2877         struct iscsi_conn *conn;
2878         struct iscsi_cls_conn *cls_conn;
2879         char *data;
2880
2881         cls_conn = iscsi_create_conn(cls_session, sizeof(*conn) + dd_size,
2882                                      conn_idx);
2883         if (!cls_conn)
2884                 return NULL;
2885         conn = cls_conn->dd_data;
2886         memset(conn, 0, sizeof(*conn) + dd_size);
2887
2888         conn->dd_data = cls_conn->dd_data + sizeof(*conn);
2889         conn->session = session;
2890         conn->cls_conn = cls_conn;
2891         conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
2892         conn->id = conn_idx;
2893         conn->exp_statsn = 0;
2894         conn->tmf_state = TMF_INITIAL;
2895
2896         init_timer(&conn->transport_timer);
2897         conn->transport_timer.data = (unsigned long)conn;
2898         conn->transport_timer.function = iscsi_check_transport_timeouts;
2899
2900         INIT_LIST_HEAD(&conn->mgmtqueue);
2901         INIT_LIST_HEAD(&conn->cmdqueue);
2902         INIT_LIST_HEAD(&conn->requeue);
2903         INIT_WORK(&conn->xmitwork, iscsi_xmitworker);
2904
2905         /* allocate login_task used for the login/text sequences */
2906         spin_lock_bh(&session->frwd_lock);
2907         if (!kfifo_out(&session->cmdpool.queue,
2908                          (void*)&conn->login_task,
2909                          sizeof(void*))) {
2910                 spin_unlock_bh(&session->frwd_lock);
2911                 goto login_task_alloc_fail;
2912         }
2913         spin_unlock_bh(&session->frwd_lock);
2914
2915         data = (char *) __get_free_pages(GFP_KERNEL,
2916                                          get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
2917         if (!data)
2918                 goto login_task_data_alloc_fail;
2919         conn->login_task->data = conn->data = data;
2920
2921         init_timer(&conn->tmf_timer);
2922         init_waitqueue_head(&conn->ehwait);
2923
2924         return cls_conn;
2925
2926 login_task_data_alloc_fail:
2927         kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
2928                     sizeof(void*));
2929 login_task_alloc_fail:
2930         iscsi_destroy_conn(cls_conn);
2931         return NULL;
2932 }
2933 EXPORT_SYMBOL_GPL(iscsi_conn_setup);
2934
2935 /**
2936  * iscsi_conn_teardown - teardown iscsi connection
2937  * cls_conn: iscsi class connection
2938  *
2939  * TODO: we may need to make this into a two step process
2940  * like scsi-mls remove + put host
2941  */
2942 void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
2943 {
2944         struct iscsi_conn *conn = cls_conn->dd_data;
2945         struct iscsi_session *session = conn->session;
2946
2947         del_timer_sync(&conn->transport_timer);
2948
2949         mutex_lock(&session->eh_mutex);
2950         spin_lock_bh(&session->frwd_lock);
2951         conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
2952         if (session->leadconn == conn) {
2953                 /*
2954                  * leading connection? then give up on recovery.
2955                  */
2956                 session->state = ISCSI_STATE_TERMINATE;
2957                 wake_up(&conn->ehwait);
2958         }
2959         spin_unlock_bh(&session->frwd_lock);
2960
2961         /* flush queued up work because we free the connection below */
2962         iscsi_suspend_tx(conn);
2963
2964         spin_lock_bh(&session->frwd_lock);
2965         free_pages((unsigned long) conn->data,
2966                    get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
2967         kfree(conn->persistent_address);
2968         kfree(conn->local_ipaddr);
2969         /* regular RX path uses back_lock */
2970         spin_lock_bh(&session->back_lock);
2971         kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
2972                     sizeof(void*));
2973         spin_unlock_bh(&session->back_lock);
2974         if (session->leadconn == conn)
2975                 session->leadconn = NULL;
2976         spin_unlock_bh(&session->frwd_lock);
2977         mutex_unlock(&session->eh_mutex);
2978
2979         iscsi_destroy_conn(cls_conn);
2980 }
2981 EXPORT_SYMBOL_GPL(iscsi_conn_teardown);
2982
2983 int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
2984 {
2985         struct iscsi_conn *conn = cls_conn->dd_data;
2986         struct iscsi_session *session = conn->session;
2987
2988         if (!session) {
2989                 iscsi_conn_printk(KERN_ERR, conn,
2990                                   "can't start unbound connection\n");
2991                 return -EPERM;
2992         }
2993
2994         if ((session->imm_data_en || !session->initial_r2t_en) &&
2995              session->first_burst > session->max_burst) {
2996                 iscsi_conn_printk(KERN_INFO, conn, "invalid burst lengths: "
2997                                   "first_burst %d max_burst %d\n",
2998                                   session->first_burst, session->max_burst);
2999                 return -EINVAL;
3000         }
3001
3002         if (conn->ping_timeout && !conn->recv_timeout) {
3003                 iscsi_conn_printk(KERN_ERR, conn, "invalid recv timeout of "
3004                                   "zero. Using 5 seconds\n.");
3005                 conn->recv_timeout = 5;
3006         }
3007
3008         if (conn->recv_timeout && !conn->ping_timeout) {
3009                 iscsi_conn_printk(KERN_ERR, conn, "invalid ping timeout of "
3010                                   "zero. Using 5 seconds.\n");
3011                 conn->ping_timeout = 5;
3012         }
3013
3014         spin_lock_bh(&session->frwd_lock);
3015         conn->c_stage = ISCSI_CONN_STARTED;
3016         session->state = ISCSI_STATE_LOGGED_IN;
3017         session->queued_cmdsn = session->cmdsn;
3018
3019         conn->last_recv = jiffies;
3020         conn->last_ping = jiffies;
3021         if (conn->recv_timeout && conn->ping_timeout)
3022                 mod_timer(&conn->transport_timer,
3023                           jiffies + (conn->recv_timeout * HZ));
3024
3025         switch(conn->stop_stage) {
3026         case STOP_CONN_RECOVER:
3027                 /*
3028                  * unblock eh_abort() if it is blocked. re-try all
3029                  * commands after successful recovery
3030                  */
3031                 conn->stop_stage = 0;
3032                 conn->tmf_state = TMF_INITIAL;
3033                 session->age++;
3034                 if (session->age == 16)
3035                         session->age = 0;
3036                 break;
3037         case STOP_CONN_TERM:
3038                 conn->stop_stage = 0;
3039                 break;
3040         default:
3041                 break;
3042         }
3043         spin_unlock_bh(&session->frwd_lock);
3044
3045         iscsi_unblock_session(session->cls_session);
3046         wake_up(&conn->ehwait);
3047         return 0;
3048 }
3049 EXPORT_SYMBOL_GPL(iscsi_conn_start);
3050
3051 static void
3052 fail_mgmt_tasks(struct iscsi_session *session, struct iscsi_conn *conn)
3053 {
3054         struct iscsi_task *task;
3055         int i, state;
3056
3057         for (i = 0; i < conn->session->cmds_max; i++) {
3058                 task = conn->session->cmds[i];
3059                 if (task->sc)
3060                         continue;
3061
3062                 if (task->state == ISCSI_TASK_FREE)
3063                         continue;
3064
3065                 ISCSI_DBG_SESSION(conn->session,
3066                                   "failing mgmt itt 0x%x state %d\n",
3067                                   task->itt, task->state);
3068                 state = ISCSI_TASK_ABRT_SESS_RECOV;
3069                 if (task->state == ISCSI_TASK_PENDING)
3070                         state = ISCSI_TASK_COMPLETED;
3071                 iscsi_complete_task(task, state);
3072
3073         }
3074 }
3075
3076 static void iscsi_start_session_recovery(struct iscsi_session *session,
3077                                          struct iscsi_conn *conn, int flag)
3078 {
3079         int old_stop_stage;
3080
3081         mutex_lock(&session->eh_mutex);
3082         spin_lock_bh(&session->frwd_lock);
3083         if (conn->stop_stage == STOP_CONN_TERM) {
3084                 spin_unlock_bh(&session->frwd_lock);
3085                 mutex_unlock(&session->eh_mutex);
3086                 return;
3087         }
3088
3089         /*
3090          * When this is called for the in_login state, we only want to clean
3091          * up the login task and connection. We do not need to block and set
3092          * the recovery state again
3093          */
3094         if (flag == STOP_CONN_TERM)
3095                 session->state = ISCSI_STATE_TERMINATE;
3096         else if (conn->stop_stage != STOP_CONN_RECOVER)
3097                 session->state = ISCSI_STATE_IN_RECOVERY;
3098
3099         old_stop_stage = conn->stop_stage;
3100         conn->stop_stage = flag;
3101         spin_unlock_bh(&session->frwd_lock);
3102
3103         del_timer_sync(&conn->transport_timer);
3104         iscsi_suspend_tx(conn);
3105
3106         spin_lock_bh(&session->frwd_lock);
3107         conn->c_stage = ISCSI_CONN_STOPPED;
3108         spin_unlock_bh(&session->frwd_lock);
3109
3110         /*
3111          * for connection level recovery we should not calculate
3112          * header digest. conn->hdr_size used for optimization
3113          * in hdr_extract() and will be re-negotiated at
3114          * set_param() time.
3115          */
3116         if (flag == STOP_CONN_RECOVER) {
3117                 conn->hdrdgst_en = 0;
3118                 conn->datadgst_en = 0;
3119                 if (session->state == ISCSI_STATE_IN_RECOVERY &&
3120                     old_stop_stage != STOP_CONN_RECOVER) {
3121                         ISCSI_DBG_SESSION(session, "blocking session\n");
3122                         iscsi_block_session(session->cls_session);
3123                 }
3124         }
3125
3126         /*
3127          * flush queues.
3128          */
3129         spin_lock_bh(&session->frwd_lock);
3130         fail_scsi_tasks(conn, -1, DID_TRANSPORT_DISRUPTED);
3131         fail_mgmt_tasks(session, conn);
3132         memset(&conn->tmhdr, 0, sizeof(conn->tmhdr));
3133         spin_unlock_bh(&session->frwd_lock);
3134         mutex_unlock(&session->eh_mutex);
3135 }
3136
3137 void iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
3138 {
3139         struct iscsi_conn *conn = cls_conn->dd_data;
3140         struct iscsi_session *session = conn->session;
3141
3142         switch (flag) {
3143         case STOP_CONN_RECOVER:
3144         case STOP_CONN_TERM:
3145                 iscsi_start_session_recovery(session, conn, flag);
3146                 break;
3147         default:
3148                 iscsi_conn_printk(KERN_ERR, conn,
3149                                   "invalid stop flag %d\n", flag);
3150         }
3151 }
3152 EXPORT_SYMBOL_GPL(iscsi_conn_stop);
3153
3154 int iscsi_conn_bind(struct iscsi_cls_session *cls_session,
3155                     struct iscsi_cls_conn *cls_conn, int is_leading)
3156 {
3157         struct iscsi_session *session = cls_session->dd_data;
3158         struct iscsi_conn *conn = cls_conn->dd_data;
3159
3160         spin_lock_bh(&session->frwd_lock);
3161         if (is_leading)
3162                 session->leadconn = conn;
3163         spin_unlock_bh(&session->frwd_lock);
3164
3165         /*
3166          * Unblock xmitworker(), Login Phase will pass through.
3167          */
3168         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
3169         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
3170         return 0;
3171 }
3172 EXPORT_SYMBOL_GPL(iscsi_conn_bind);
3173
3174 int iscsi_switch_str_param(char **param, char *new_val_buf)
3175 {
3176         char *new_val;
3177
3178         if (*param) {
3179                 if (!strcmp(*param, new_val_buf))
3180                         return 0;
3181         }
3182
3183         new_val = kstrdup(new_val_buf, GFP_NOIO);
3184         if (!new_val)
3185                 return -ENOMEM;
3186
3187         kfree(*param);
3188         *param = new_val;
3189         return 0;
3190 }
3191 EXPORT_SYMBOL_GPL(iscsi_switch_str_param);
3192
3193 int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
3194                     enum iscsi_param param, char *buf, int buflen)
3195 {
3196         struct iscsi_conn *conn = cls_conn->dd_data;
3197         struct iscsi_session *session = conn->session;
3198         int val;
3199
3200         switch(param) {
3201         case ISCSI_PARAM_FAST_ABORT:
3202                 sscanf(buf, "%d", &session->fast_abort);
3203                 break;
3204         case ISCSI_PARAM_ABORT_TMO:
3205                 sscanf(buf, "%d", &session->abort_timeout);
3206                 break;
3207         case ISCSI_PARAM_LU_RESET_TMO:
3208                 sscanf(buf, "%d", &session->lu_reset_timeout);
3209                 break;
3210         case ISCSI_PARAM_TGT_RESET_TMO:
3211                 sscanf(buf, "%d", &session->tgt_reset_timeout);
3212                 break;
3213         case ISCSI_PARAM_PING_TMO:
3214                 sscanf(buf, "%d", &conn->ping_timeout);
3215                 break;
3216         case ISCSI_PARAM_RECV_TMO:
3217                 sscanf(buf, "%d", &conn->recv_timeout);
3218                 break;
3219         case ISCSI_PARAM_MAX_RECV_DLENGTH:
3220                 sscanf(buf, "%d", &conn->max_recv_dlength);
3221                 break;
3222         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3223                 sscanf(buf, "%d", &conn->max_xmit_dlength);
3224                 break;
3225         case ISCSI_PARAM_HDRDGST_EN:
3226                 sscanf(buf, "%d", &conn->hdrdgst_en);
3227                 break;
3228         case ISCSI_PARAM_DATADGST_EN:
3229                 sscanf(buf, "%d", &conn->datadgst_en);
3230                 break;
3231         case ISCSI_PARAM_INITIAL_R2T_EN:
3232                 sscanf(buf, "%d", &session->initial_r2t_en);
3233                 break;
3234         case ISCSI_PARAM_MAX_R2T:
3235                 sscanf(buf, "%hu", &session->max_r2t);
3236                 break;
3237         case ISCSI_PARAM_IMM_DATA_EN:
3238                 sscanf(buf, "%d", &session->imm_data_en);
3239                 break;
3240         case ISCSI_PARAM_FIRST_BURST:
3241                 sscanf(buf, "%d", &session->first_burst);
3242                 break;
3243         case ISCSI_PARAM_MAX_BURST:
3244                 sscanf(buf, "%d", &session->max_burst);
3245                 break;
3246         case ISCSI_PARAM_PDU_INORDER_EN:
3247                 sscanf(buf, "%d", &session->pdu_inorder_en);
3248                 break;
3249         case ISCSI_PARAM_DATASEQ_INORDER_EN:
3250                 sscanf(buf, "%d", &session->dataseq_inorder_en);
3251                 break;
3252         case ISCSI_PARAM_ERL:
3253                 sscanf(buf, "%d", &session->erl);
3254                 break;
3255         case ISCSI_PARAM_EXP_STATSN:
3256                 sscanf(buf, "%u", &conn->exp_statsn);
3257                 break;
3258         case ISCSI_PARAM_USERNAME:
3259                 return iscsi_switch_str_param(&session->username, buf);
3260         case ISCSI_PARAM_USERNAME_IN:
3261                 return iscsi_switch_str_param(&session->username_in, buf);
3262         case ISCSI_PARAM_PASSWORD:
3263                 return iscsi_switch_str_param(&session->password, buf);
3264         case ISCSI_PARAM_PASSWORD_IN:
3265                 return iscsi_switch_str_param(&session->password_in, buf);
3266         case ISCSI_PARAM_TARGET_NAME:
3267                 return iscsi_switch_str_param(&session->targetname, buf);
3268         case ISCSI_PARAM_TARGET_ALIAS:
3269                 return iscsi_switch_str_param(&session->targetalias, buf);
3270         case ISCSI_PARAM_TPGT:
3271                 sscanf(buf, "%d", &session->tpgt);
3272                 break;
3273         case ISCSI_PARAM_PERSISTENT_PORT:
3274                 sscanf(buf, "%d", &conn->persistent_port);
3275                 break;
3276         case ISCSI_PARAM_PERSISTENT_ADDRESS:
3277                 return iscsi_switch_str_param(&conn->persistent_address, buf);
3278         case ISCSI_PARAM_IFACE_NAME:
3279                 return iscsi_switch_str_param(&session->ifacename, buf);
3280         case ISCSI_PARAM_INITIATOR_NAME:
3281                 return iscsi_switch_str_param(&session->initiatorname, buf);
3282         case ISCSI_PARAM_BOOT_ROOT:
3283                 return iscsi_switch_str_param(&session->boot_root, buf);
3284         case ISCSI_PARAM_BOOT_NIC:
3285                 return iscsi_switch_str_param(&session->boot_nic, buf);
3286         case ISCSI_PARAM_BOOT_TARGET:
3287                 return iscsi_switch_str_param(&session->boot_target, buf);
3288         case ISCSI_PARAM_PORTAL_TYPE:
3289                 return iscsi_switch_str_param(&session->portal_type, buf);
3290         case ISCSI_PARAM_DISCOVERY_PARENT_TYPE:
3291                 return iscsi_switch_str_param(&session->discovery_parent_type,
3292                                               buf);
3293         case ISCSI_PARAM_DISCOVERY_SESS:
3294                 sscanf(buf, "%d", &val);
3295                 session->discovery_sess = !!val;
3296                 break;
3297         case ISCSI_PARAM_LOCAL_IPADDR:
3298                 return iscsi_switch_str_param(&conn->local_ipaddr, buf);
3299         default:
3300                 return -ENOSYS;
3301         }
3302
3303         return 0;
3304 }
3305 EXPORT_SYMBOL_GPL(iscsi_set_param);
3306
3307 int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
3308                             enum iscsi_param param, char *buf)
3309 {
3310         struct iscsi_session *session = cls_session->dd_data;
3311         int len;
3312
3313         switch(param) {
3314         case ISCSI_PARAM_FAST_ABORT:
3315                 len = sprintf(buf, "%d\n", session->fast_abort);
3316                 break;
3317         case ISCSI_PARAM_ABORT_TMO:
3318                 len = sprintf(buf, "%d\n", session->abort_timeout);
3319                 break;
3320         case ISCSI_PARAM_LU_RESET_TMO:
3321                 len = sprintf(buf, "%d\n", session->lu_reset_timeout);
3322                 break;
3323         case ISCSI_PARAM_TGT_RESET_TMO:
3324                 len = sprintf(buf, "%d\n", session->tgt_reset_timeout);
3325                 break;
3326         case ISCSI_PARAM_INITIAL_R2T_EN:
3327                 len = sprintf(buf, "%d\n", session->initial_r2t_en);
3328                 break;
3329         case ISCSI_PARAM_MAX_R2T:
3330                 len = sprintf(buf, "%hu\n", session->max_r2t);
3331                 break;
3332         case ISCSI_PARAM_IMM_DATA_EN:
3333                 len = sprintf(buf, "%d\n", session->imm_data_en);
3334                 break;
3335         case ISCSI_PARAM_FIRST_BURST:
3336                 len = sprintf(buf, "%u\n", session->first_burst);
3337                 break;
3338         case ISCSI_PARAM_MAX_BURST:
3339                 len = sprintf(buf, "%u\n", session->max_burst);
3340                 break;
3341         case ISCSI_PARAM_PDU_INORDER_EN:
3342                 len = sprintf(buf, "%d\n", session->pdu_inorder_en);
3343                 break;
3344         case ISCSI_PARAM_DATASEQ_INORDER_EN:
3345                 len = sprintf(buf, "%d\n", session->dataseq_inorder_en);
3346                 break;
3347         case ISCSI_PARAM_DEF_TASKMGMT_TMO:
3348                 len = sprintf(buf, "%d\n", session->def_taskmgmt_tmo);
3349                 break;
3350         case ISCSI_PARAM_ERL:
3351                 len = sprintf(buf, "%d\n", session->erl);
3352                 break;
3353         case ISCSI_PARAM_TARGET_NAME:
3354                 len = sprintf(buf, "%s\n", session->targetname);
3355                 break;
3356         case ISCSI_PARAM_TARGET_ALIAS:
3357                 len = sprintf(buf, "%s\n", session->targetalias);
3358                 break;
3359         case ISCSI_PARAM_TPGT:
3360                 len = sprintf(buf, "%d\n", session->tpgt);
3361                 break;
3362         case ISCSI_PARAM_USERNAME:
3363                 len = sprintf(buf, "%s\n", session->username);
3364                 break;
3365         case ISCSI_PARAM_USERNAME_IN:
3366                 len = sprintf(buf, "%s\n", session->username_in);
3367                 break;
3368         case ISCSI_PARAM_PASSWORD:
3369                 len = sprintf(buf, "%s\n", session->password);
3370                 break;
3371         case ISCSI_PARAM_PASSWORD_IN:
3372                 len = sprintf(buf, "%s\n", session->password_in);
3373                 break;
3374         case ISCSI_PARAM_IFACE_NAME:
3375                 len = sprintf(buf, "%s\n", session->ifacename);
3376                 break;
3377         case ISCSI_PARAM_INITIATOR_NAME:
3378                 len = sprintf(buf, "%s\n", session->initiatorname);
3379                 break;
3380         case ISCSI_PARAM_BOOT_ROOT:
3381                 len = sprintf(buf, "%s\n", session->boot_root);
3382                 break;
3383         case ISCSI_PARAM_BOOT_NIC:
3384                 len = sprintf(buf, "%s\n", session->boot_nic);
3385                 break;
3386         case ISCSI_PARAM_BOOT_TARGET:
3387                 len = sprintf(buf, "%s\n", session->boot_target);
3388                 break;
3389         case ISCSI_PARAM_AUTO_SND_TGT_DISABLE:
3390                 len = sprintf(buf, "%u\n", session->auto_snd_tgt_disable);
3391                 break;
3392         case ISCSI_PARAM_DISCOVERY_SESS:
3393                 len = sprintf(buf, "%u\n", session->discovery_sess);
3394                 break;
3395         case ISCSI_PARAM_PORTAL_TYPE:
3396                 len = sprintf(buf, "%s\n", session->portal_type);
3397                 break;
3398         case ISCSI_PARAM_CHAP_AUTH_EN:
3399                 len = sprintf(buf, "%u\n", session->chap_auth_en);
3400                 break;
3401         case ISCSI_PARAM_DISCOVERY_LOGOUT_EN:
3402                 len = sprintf(buf, "%u\n", session->discovery_logout_en);
3403                 break;
3404         case ISCSI_PARAM_BIDI_CHAP_EN:
3405                 len = sprintf(buf, "%u\n", session->bidi_chap_en);
3406                 break;
3407         case ISCSI_PARAM_DISCOVERY_AUTH_OPTIONAL:
3408                 len = sprintf(buf, "%u\n", session->discovery_auth_optional);
3409                 break;
3410         case ISCSI_PARAM_DEF_TIME2WAIT:
3411                 len = sprintf(buf, "%d\n", session->time2wait);
3412                 break;
3413         case ISCSI_PARAM_DEF_TIME2RETAIN:
3414                 len = sprintf(buf, "%d\n", session->time2retain);
3415                 break;
3416         case ISCSI_PARAM_TSID:
3417                 len = sprintf(buf, "%u\n", session->tsid);
3418                 break;
3419         case ISCSI_PARAM_ISID:
3420                 len = sprintf(buf, "%02x%02x%02x%02x%02x%02x\n",
3421                               session->isid[0], session->isid[1],
3422                               session->isid[2], session->isid[3],
3423                               session->isid[4], session->isid[5]);
3424                 break;
3425         case ISCSI_PARAM_DISCOVERY_PARENT_IDX:
3426                 len = sprintf(buf, "%u\n", session->discovery_parent_idx);
3427                 break;
3428         case ISCSI_PARAM_DISCOVERY_PARENT_TYPE:
3429                 if (session->discovery_parent_type)
3430                         len = sprintf(buf, "%s\n",
3431                                       session->discovery_parent_type);
3432                 else
3433                         len = sprintf(buf, "\n");
3434                 break;
3435         default:
3436                 return -ENOSYS;
3437         }
3438
3439         return len;
3440 }
3441 EXPORT_SYMBOL_GPL(iscsi_session_get_param);
3442
3443 int iscsi_conn_get_addr_param(struct sockaddr_storage *addr,
3444                               enum iscsi_param param, char *buf)
3445 {
3446         struct sockaddr_in6 *sin6 = NULL;
3447         struct sockaddr_in *sin = NULL;
3448         int len;
3449
3450         switch (addr->ss_family) {
3451         case AF_INET:
3452                 sin = (struct sockaddr_in *)addr;
3453                 break;
3454         case AF_INET6:
3455                 sin6 = (struct sockaddr_in6 *)addr;
3456                 break;
3457         default:
3458                 return -EINVAL;
3459         }
3460
3461         switch (param) {
3462         case ISCSI_PARAM_CONN_ADDRESS:
3463         case ISCSI_HOST_PARAM_IPADDRESS:
3464                 if (sin)
3465                         len = sprintf(buf, "%pI4\n", &sin->sin_addr.s_addr);
3466                 else
3467                         len = sprintf(buf, "%pI6\n", &sin6->sin6_addr);
3468                 break;
3469         case ISCSI_PARAM_CONN_PORT:
3470         case ISCSI_PARAM_LOCAL_PORT:
3471                 if (sin)
3472                         len = sprintf(buf, "%hu\n", be16_to_cpu(sin->sin_port));
3473                 else
3474                         len = sprintf(buf, "%hu\n",
3475                                       be16_to_cpu(sin6->sin6_port));
3476                 break;
3477         default:
3478                 return -EINVAL;
3479         }
3480
3481         return len;
3482 }
3483 EXPORT_SYMBOL_GPL(iscsi_conn_get_addr_param);
3484
3485 int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
3486                          enum iscsi_param param, char *buf)
3487 {
3488         struct iscsi_conn *conn = cls_conn->dd_data;
3489         int len;
3490
3491         switch(param) {
3492         case ISCSI_PARAM_PING_TMO:
3493                 len = sprintf(buf, "%u\n", conn->ping_timeout);
3494                 break;
3495         case ISCSI_PARAM_RECV_TMO:
3496                 len = sprintf(buf, "%u\n", conn->recv_timeout);
3497                 break;
3498         case ISCSI_PARAM_MAX_RECV_DLENGTH:
3499                 len = sprintf(buf, "%u\n", conn->max_recv_dlength);
3500                 break;
3501         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3502                 len = sprintf(buf, "%u\n", conn->max_xmit_dlength);
3503                 break;
3504         case ISCSI_PARAM_HDRDGST_EN:
3505                 len = sprintf(buf, "%d\n", conn->hdrdgst_en);
3506                 break;
3507         case ISCSI_PARAM_DATADGST_EN:
3508                 len = sprintf(buf, "%d\n", conn->datadgst_en);
3509                 break;
3510         case ISCSI_PARAM_IFMARKER_EN:
3511                 len = sprintf(buf, "%d\n", conn->ifmarker_en);
3512                 break;
3513         case ISCSI_PARAM_OFMARKER_EN:
3514                 len = sprintf(buf, "%d\n", conn->ofmarker_en);
3515                 break;
3516         case ISCSI_PARAM_EXP_STATSN:
3517                 len = sprintf(buf, "%u\n", conn->exp_statsn);
3518                 break;
3519         case ISCSI_PARAM_PERSISTENT_PORT:
3520                 len = sprintf(buf, "%d\n", conn->persistent_port);
3521                 break;
3522         case ISCSI_PARAM_PERSISTENT_ADDRESS:
3523                 len = sprintf(buf, "%s\n", conn->persistent_address);
3524                 break;
3525         case ISCSI_PARAM_STATSN:
3526                 len = sprintf(buf, "%u\n", conn->statsn);
3527                 break;
3528         case ISCSI_PARAM_MAX_SEGMENT_SIZE:
3529                 len = sprintf(buf, "%u\n", conn->max_segment_size);
3530                 break;
3531         case ISCSI_PARAM_KEEPALIVE_TMO:
3532                 len = sprintf(buf, "%u\n", conn->keepalive_tmo);
3533                 break;
3534         case ISCSI_PARAM_LOCAL_PORT:
3535                 len = sprintf(buf, "%u\n", conn->local_port);
3536                 break;
3537         case ISCSI_PARAM_TCP_TIMESTAMP_STAT:
3538                 len = sprintf(buf, "%u\n", conn->tcp_timestamp_stat);
3539                 break;
3540         case ISCSI_PARAM_TCP_NAGLE_DISABLE:
3541                 len = sprintf(buf, "%u\n", conn->tcp_nagle_disable);
3542                 break;
3543         case ISCSI_PARAM_TCP_WSF_DISABLE:
3544                 len = sprintf(buf, "%u\n", conn->tcp_wsf_disable);
3545                 break;
3546         case ISCSI_PARAM_TCP_TIMER_SCALE:
3547                 len = sprintf(buf, "%u\n", conn->tcp_timer_scale);
3548                 break;
3549         case ISCSI_PARAM_TCP_TIMESTAMP_EN:
3550                 len = sprintf(buf, "%u\n", conn->tcp_timestamp_en);
3551                 break;
3552         case ISCSI_PARAM_IP_FRAGMENT_DISABLE:
3553                 len = sprintf(buf, "%u\n", conn->fragment_disable);
3554                 break;
3555         case ISCSI_PARAM_IPV4_TOS:
3556                 len = sprintf(buf, "%u\n", conn->ipv4_tos);
3557                 break;
3558         case ISCSI_PARAM_IPV6_TC:
3559                 len = sprintf(buf, "%u\n", conn->ipv6_traffic_class);
3560                 break;
3561         case ISCSI_PARAM_IPV6_FLOW_LABEL:
3562                 len = sprintf(buf, "%u\n", conn->ipv6_flow_label);
3563                 break;
3564         case ISCSI_PARAM_IS_FW_ASSIGNED_IPV6:
3565                 len = sprintf(buf, "%u\n", conn->is_fw_assigned_ipv6);
3566                 break;
3567         case ISCSI_PARAM_TCP_XMIT_WSF:
3568                 len = sprintf(buf, "%u\n", conn->tcp_xmit_wsf);
3569                 break;
3570         case ISCSI_PARAM_TCP_RECV_WSF:
3571                 len = sprintf(buf, "%u\n", conn->tcp_recv_wsf);
3572                 break;
3573         case ISCSI_PARAM_LOCAL_IPADDR:
3574                 len = sprintf(buf, "%s\n", conn->local_ipaddr);
3575                 break;
3576         default:
3577                 return -ENOSYS;
3578         }
3579
3580         return len;
3581 }
3582 EXPORT_SYMBOL_GPL(iscsi_conn_get_param);
3583
3584 int iscsi_host_get_param(struct Scsi_Host *shost, enum iscsi_host_param param,
3585                          char *buf)
3586 {
3587         struct iscsi_host *ihost = shost_priv(shost);
3588         int len;
3589
3590         switch (param) {
3591         case ISCSI_HOST_PARAM_NETDEV_NAME:
3592                 len = sprintf(buf, "%s\n", ihost->netdev);
3593                 break;
3594         case ISCSI_HOST_PARAM_HWADDRESS:
3595                 len = sprintf(buf, "%s\n", ihost->hwaddress);
3596                 break;
3597         case ISCSI_HOST_PARAM_INITIATOR_NAME:
3598                 len = sprintf(buf, "%s\n", ihost->initiatorname);
3599                 break;
3600         default:
3601                 return -ENOSYS;
3602         }
3603
3604         return len;
3605 }
3606 EXPORT_SYMBOL_GPL(iscsi_host_get_param);
3607
3608 int iscsi_host_set_param(struct Scsi_Host *shost, enum iscsi_host_param param,
3609                          char *buf, int buflen)
3610 {
3611         struct iscsi_host *ihost = shost_priv(shost);
3612
3613         switch (param) {
3614         case ISCSI_HOST_PARAM_NETDEV_NAME:
3615                 return iscsi_switch_str_param(&ihost->netdev, buf);
3616         case ISCSI_HOST_PARAM_HWADDRESS:
3617                 return iscsi_switch_str_param(&ihost->hwaddress, buf);
3618         case ISCSI_HOST_PARAM_INITIATOR_NAME:
3619                 return iscsi_switch_str_param(&ihost->initiatorname, buf);
3620         default:
3621                 return -ENOSYS;
3622         }
3623
3624         return 0;
3625 }
3626 EXPORT_SYMBOL_GPL(iscsi_host_set_param);
3627
3628 MODULE_AUTHOR("Mike Christie");
3629 MODULE_DESCRIPTION("iSCSI library functions");
3630 MODULE_LICENSE("GPL");