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 [email protected]
   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                         sc->sense_buffer[7] = 0xc; /* Additional sense length */
 857                         sc->sense_buffer[8] = 0;   /* Information desc type */
 858                         sc->sense_buffer[9] = 0xa; /* Additional desc length */
 859                         sc->sense_buffer[10] = 0x80; /* Validity bit */
 860
 861                         put_unaligned_be64(sector, &sc->sense_buffer[12]);
 862                         goto out;
 863                 }
 864         }
 865
 866         if (rhdr->response != ISCSI_STATUS_CMD_COMPLETED) {
 867                 sc->result = DID_ERROR << 16;
 868                 goto out;
 869         }
 870
 871         if (rhdr->cmd_status == SAM_STAT_CHECK_CONDITION) {
 872                 uint16_t senselen;
 873
 874                 if (datalen < 2) {
 875 invalid_datalen:
 876                         iscsi_conn_printk(KERN_ERR,  conn,
 877                                          "Got CHECK_CONDITION but invalid data "
 878                                          "buffer size of %d\n", datalen);
 879                         sc->result = DID_BAD_TARGET << 16;
 880                         goto out;
 881                 }
 882
 883                 senselen = get_unaligned_be16(data);
 884                 if (datalen < senselen)
 885                         goto invalid_datalen;
 886
 887                 memcpy(sc->sense_buffer, data + 2,
 888                        min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
 889                 ISCSI_DBG_SESSION(session, "copied %d bytes of sense\n",
 890                                   min_t(uint16_t, senselen,
 891                                   SCSI_SENSE_BUFFERSIZE));
 892         }
 893
 894         if (rhdr->flags & (ISCSI_FLAG_CMD_BIDI_UNDERFLOW |
 895                            ISCSI_FLAG_CMD_BIDI_OVERFLOW)) {
 896                 int res_count = be32_to_cpu(rhdr->bi_residual_count);
 897
 898                 if (scsi_bidi_cmnd(sc) && res_count > 0 &&
 899                                 (rhdr->flags & ISCSI_FLAG_CMD_BIDI_OVERFLOW ||
 900                                  res_count <= scsi_in(sc)->length))
 901                         scsi_in(sc)->resid = res_count;
 902                 else
 903                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 904         }
 905
 906         if (rhdr->flags & (ISCSI_FLAG_CMD_UNDERFLOW |
 907                            ISCSI_FLAG_CMD_OVERFLOW)) {
 908                 int res_count = be32_to_cpu(rhdr->residual_count);
 909
 910                 if (res_count > 0 &&
 911                     (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
 912                      res_count <= scsi_bufflen(sc)))
 913                         /* write side for bidi or uni-io set_resid */
 914                         scsi_set_resid(sc, res_count);
 915                 else
 916                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 917         }
 918 out:
 919         ISCSI_DBG_SESSION(session, "cmd rsp done [sc %p res %d itt 0x%x]\n",
 920                           sc, sc->result, task->itt);
 921         conn->scsirsp_pdus_cnt++;
 922         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 923 }
 924
 925 /**
 926  * iscsi_data_in_rsp - SCSI Data-In Response processing
 927  * @conn: iscsi connection
 928  * @hdr:  iscsi pdu
 929  * @task: scsi command task
 930  **/
 931 static void
 932 iscsi_data_in_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 933                   struct iscsi_task *task)
 934 {
 935         struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)hdr;
 936         struct scsi_cmnd *sc = task->sc;
 937
 938         if (!(rhdr->flags & ISCSI_FLAG_DATA_STATUS))
 939                 return;
 940
 941         iscsi_update_cmdsn(conn->session, (struct iscsi_nopin *)hdr);
 942         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 943         conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 944         if (rhdr->flags & (ISCSI_FLAG_DATA_UNDERFLOW |
 945                            ISCSI_FLAG_DATA_OVERFLOW)) {
 946                 int res_count = be32_to_cpu(rhdr->residual_count);
 947
 948                 if (res_count > 0 &&
 949                     (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
 950                      res_count <= scsi_in(sc)->length))
 951                         scsi_in(sc)->resid = res_count;
 952                 else
 953                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 954         }
 955
 956         ISCSI_DBG_SESSION(conn->session, "data in with status done "
 957                           "[sc %p res %d itt 0x%x]\n",
 958                           sc, sc->result, task->itt);
 959         conn->scsirsp_pdus_cnt++;
 960         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 961 }
 962
 963 static void iscsi_tmf_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
 964 {
 965         struct iscsi_tm_rsp *tmf = (struct iscsi_tm_rsp *)hdr;
 966
 967         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 968         conn->tmfrsp_pdus_cnt++;
 969
 970         if (conn->tmf_state != TMF_QUEUED)
 971                 return;
 972
 973         if (tmf->response == ISCSI_TMF_RSP_COMPLETE)
 974                 conn->tmf_state = TMF_SUCCESS;
 975         else if (tmf->response == ISCSI_TMF_RSP_NO_TASK)
 976                 conn->tmf_state = TMF_NOT_FOUND;
 977         else
 978                 conn->tmf_state = TMF_FAILED;
 979         wake_up(&conn->ehwait);
 980 }
 981
 982 static void iscsi_send_nopout(struct iscsi_conn *conn, struct iscsi_nopin *rhdr)
 983 {
 984         struct iscsi_nopout hdr;
 985         struct iscsi_task *task;
 986
 987         if (!rhdr && conn->ping_task)
 988                 return;
 989
 990         memset(&hdr, 0, sizeof(struct iscsi_nopout));
 991         hdr.opcode = ISCSI_OP_NOOP_OUT | ISCSI_OP_IMMEDIATE;
 992         hdr.flags = ISCSI_FLAG_CMD_FINAL;
 993
 994         if (rhdr) {
 995                 hdr.lun = rhdr->lun;
 996                 hdr.ttt = rhdr->ttt;
 997                 hdr.itt = RESERVED_ITT;
 998         } else
 999                 hdr.ttt = RESERVED_ITT;
1000
1001         task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)&hdr, NULL, 0);
1002         if (!task)
1003                 iscsi_conn_printk(KERN_ERR, conn, "Could not send nopout\n");
1004         else if (!rhdr) {
1005                 /* only track our nops */
1006                 conn->ping_task = task;
1007                 conn->last_ping = jiffies;
1008         }
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_change_queue_depth(struct scsi_device *sdev, int depth, int reason)
1775 {
1776         switch (reason) {
1777         case SCSI_QDEPTH_DEFAULT:
1778                 scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
1779                 break;
1780         case SCSI_QDEPTH_QFULL:
1781                 scsi_track_queue_full(sdev, depth);
1782                 break;
1783         case SCSI_QDEPTH_RAMP_UP:
1784                 scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
1785                 break;
1786         default:
1787                 return -EOPNOTSUPP;
1788         }
1789         return sdev->queue_depth;
1790 }
1791 EXPORT_SYMBOL_GPL(iscsi_change_queue_depth);
1792
1793 int iscsi_target_alloc(struct scsi_target *starget)
1794 {
1795         struct iscsi_cls_session *cls_session = starget_to_session(starget);
1796         struct iscsi_session *session = cls_session->dd_data;
1797
1798         starget->can_queue = session->scsi_cmds_max;
1799         return 0;
1800 }
1801 EXPORT_SYMBOL_GPL(iscsi_target_alloc);
1802
1803 static void iscsi_tmf_timedout(unsigned long data)
1804 {
1805         struct iscsi_conn *conn = (struct iscsi_conn *)data;
1806         struct iscsi_session *session = conn->session;
1807
1808         spin_lock(&session->frwd_lock);
1809         if (conn->tmf_state == TMF_QUEUED) {
1810                 conn->tmf_state = TMF_TIMEDOUT;
1811                 ISCSI_DBG_EH(session, "tmf timedout\n");
1812                 /* unblock eh_abort() */
1813                 wake_up(&conn->ehwait);
1814         }
1815         spin_unlock(&session->frwd_lock);
1816 }
1817
1818 static int iscsi_exec_task_mgmt_fn(struct iscsi_conn *conn,
1819                                    struct iscsi_tm *hdr, int age,
1820                                    int timeout)
1821 {
1822         struct iscsi_session *session = conn->session;
1823         struct iscsi_task *task;
1824
1825         task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)hdr,
1826                                       NULL, 0);
1827         if (!task) {
1828                 spin_unlock_bh(&session->frwd_lock);
1829                 iscsi_conn_printk(KERN_ERR, conn, "Could not send TMF.\n");
1830                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1831                 spin_lock_bh(&session->frwd_lock);
1832                 return -EPERM;
1833         }
1834         conn->tmfcmd_pdus_cnt++;
1835         conn->tmf_timer.expires = timeout * HZ + jiffies;
1836         conn->tmf_timer.function = iscsi_tmf_timedout;
1837         conn->tmf_timer.data = (unsigned long)conn;
1838         add_timer(&conn->tmf_timer);
1839         ISCSI_DBG_EH(session, "tmf set timeout\n");
1840
1841         spin_unlock_bh(&session->frwd_lock);
1842         mutex_unlock(&session->eh_mutex);
1843
1844         /*
1845          * block eh thread until:
1846          *
1847          * 1) tmf response
1848          * 2) tmf timeout
1849          * 3) session is terminated or restarted or userspace has
1850          * given up on recovery
1851          */
1852         wait_event_interruptible(conn->ehwait, age != session->age ||
1853                                  session->state != ISCSI_STATE_LOGGED_IN ||
1854                                  conn->tmf_state != TMF_QUEUED);
1855         if (signal_pending(current))
1856                 flush_signals(current);
1857         del_timer_sync(&conn->tmf_timer);
1858
1859         mutex_lock(&session->eh_mutex);
1860         spin_lock_bh(&session->frwd_lock);
1861         /* if the session drops it will clean up the task */
1862         if (age != session->age ||
1863             session->state != ISCSI_STATE_LOGGED_IN)
1864                 return -ENOTCONN;
1865         return 0;
1866 }
1867
1868 /*
1869  * Fail commands. session lock held and recv side suspended and xmit
1870  * thread flushed
1871  */
1872 static void fail_scsi_tasks(struct iscsi_conn *conn, u64 lun, int error)
1873 {
1874         struct iscsi_task *task;
1875         int i;
1876
1877         for (i = 0; i < conn->session->cmds_max; i++) {
1878                 task = conn->session->cmds[i];
1879                 if (!task->sc || task->state == ISCSI_TASK_FREE)
1880                         continue;
1881
1882                 if (lun != -1 && lun != task->sc->device->lun)
1883                         continue;
1884
1885                 ISCSI_DBG_SESSION(conn->session,
1886                                   "failing sc %p itt 0x%x state %d\n",
1887                                   task->sc, task->itt, task->state);
1888                 fail_scsi_task(task, error);
1889         }
1890 }
1891
1892 /**
1893  * iscsi_suspend_queue - suspend iscsi_queuecommand
1894  * @conn: iscsi conn to stop queueing IO on
1895  *
1896  * This grabs the session frwd_lock to make sure no one is in
1897  * xmit_task/queuecommand, and then sets suspend to prevent
1898  * new commands from being queued. This only needs to be called
1899  * by offload drivers that need to sync a path like ep disconnect
1900  * with the iscsi_queuecommand/xmit_task. To start IO again libiscsi
1901  * will call iscsi_start_tx and iscsi_unblock_session when in FFP.
1902  */
1903 void iscsi_suspend_queue(struct iscsi_conn *conn)
1904 {
1905         spin_lock_bh(&conn->session->frwd_lock);
1906         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1907         spin_unlock_bh(&conn->session->frwd_lock);
1908 }
1909 EXPORT_SYMBOL_GPL(iscsi_suspend_queue);
1910
1911 /**
1912  * iscsi_suspend_tx - suspend iscsi_data_xmit
1913  * @conn: iscsi conn tp stop processing IO on.
1914  *
1915  * This function sets the suspend bit to prevent iscsi_data_xmit
1916  * from sending new IO, and if work is queued on the xmit thread
1917  * it will wait for it to be completed.
1918  */
1919 void iscsi_suspend_tx(struct iscsi_conn *conn)
1920 {
1921         struct Scsi_Host *shost = conn->session->host;
1922         struct iscsi_host *ihost = shost_priv(shost);
1923
1924         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1925         if (ihost->workq)
1926                 flush_workqueue(ihost->workq);
1927 }
1928 EXPORT_SYMBOL_GPL(iscsi_suspend_tx);
1929
1930 static void iscsi_start_tx(struct iscsi_conn *conn)
1931 {
1932         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1933         iscsi_conn_queue_work(conn);
1934 }
1935
1936 /*
1937  * We want to make sure a ping is in flight. It has timed out.
1938  * And we are not busy processing a pdu that is making
1939  * progress but got started before the ping and is taking a while
1940  * to complete so the ping is just stuck behind it in a queue.
1941  */
1942 static int iscsi_has_ping_timed_out(struct iscsi_conn *conn)
1943 {
1944         if (conn->ping_task &&
1945             time_before_eq(conn->last_recv + (conn->recv_timeout * HZ) +
1946                            (conn->ping_timeout * HZ), jiffies))
1947                 return 1;
1948         else
1949                 return 0;
1950 }
1951
1952 static enum blk_eh_timer_return iscsi_eh_cmd_timed_out(struct scsi_cmnd *sc)
1953 {
1954         enum blk_eh_timer_return rc = BLK_EH_NOT_HANDLED;
1955         struct iscsi_task *task = NULL, *running_task;
1956         struct iscsi_cls_session *cls_session;
1957         struct iscsi_session *session;
1958         struct iscsi_conn *conn;
1959         int i;
1960
1961         cls_session = starget_to_session(scsi_target(sc->device));
1962         session = cls_session->dd_data;
1963
1964         ISCSI_DBG_EH(session, "scsi cmd %p timedout\n", sc);
1965
1966         spin_lock(&session->frwd_lock);
1967         task = (struct iscsi_task *)sc->SCp.ptr;
1968         if (!task) {
1969                 /*
1970                  * Raced with completion. Blk layer has taken ownership
1971                  * so let timeout code complete it now.
1972                  */
1973                 rc = BLK_EH_HANDLED;
1974                 goto done;
1975         }
1976
1977         if (session->state != ISCSI_STATE_LOGGED_IN) {
1978                 /*
1979                  * We are probably in the middle of iscsi recovery so let
1980                  * that complete and handle the error.
1981                  */
1982                 rc = BLK_EH_RESET_TIMER;
1983                 goto done;
1984         }
1985
1986         conn = session->leadconn;
1987         if (!conn) {
1988                 /* In the middle of shuting down */
1989                 rc = BLK_EH_RESET_TIMER;
1990                 goto done;
1991         }
1992
1993         /*
1994          * If we have sent (at least queued to the network layer) a pdu or
1995          * recvd one for the task since the last timeout ask for
1996          * more time. If on the next timeout we have not made progress
1997          * we can check if it is the task or connection when we send the
1998          * nop as a ping.
1999          */
2000         if (time_after(task->last_xfer, task->last_timeout)) {
2001                 ISCSI_DBG_EH(session, "Command making progress. Asking "
2002                              "scsi-ml for more time to complete. "
2003                              "Last data xfer at %lu. Last timeout was at "
2004                              "%lu\n.", task->last_xfer, task->last_timeout);
2005                 task->have_checked_conn = false;
2006                 rc = BLK_EH_RESET_TIMER;
2007                 goto done;
2008         }
2009
2010         if (!conn->recv_timeout && !conn->ping_timeout)
2011                 goto done;
2012         /*
2013          * if the ping timedout then we are in the middle of cleaning up
2014          * and can let the iscsi eh handle it
2015          */
2016         if (iscsi_has_ping_timed_out(conn)) {
2017                 rc = BLK_EH_RESET_TIMER;
2018                 goto done;
2019         }
2020
2021         for (i = 0; i < conn->session->cmds_max; i++) {
2022                 running_task = conn->session->cmds[i];
2023                 if (!running_task->sc || running_task == task ||
2024                      running_task->state != ISCSI_TASK_RUNNING)
2025                         continue;
2026
2027                 /*
2028                  * Only check if cmds started before this one have made
2029                  * progress, or this could never fail
2030                  */
2031                 if (time_after(running_task->sc->jiffies_at_alloc,
2032                                task->sc->jiffies_at_alloc))
2033                         continue;
2034
2035                 if (time_after(running_task->last_xfer, task->last_timeout)) {
2036                         /*
2037                          * This task has not made progress, but a task
2038                          * started before us has transferred data since
2039                          * we started/last-checked. We could be queueing
2040                          * too many tasks or the LU is bad.
2041                          *
2042                          * If the device is bad the cmds ahead of us on
2043                          * other devs will complete, and this loop will
2044                          * eventually fail starting the scsi eh.
2045                          */
2046                         ISCSI_DBG_EH(session, "Command has not made progress "
2047                                      "but commands ahead of it have. "
2048                                      "Asking scsi-ml for more time to "
2049                                      "complete. Our last xfer vs running task "
2050                                      "last xfer %lu/%lu. Last check %lu.\n",
2051                                      task->last_xfer, running_task->last_xfer,
2052                                      task->last_timeout);
2053                         rc = BLK_EH_RESET_TIMER;
2054                         goto done;
2055                 }
2056         }
2057
2058         /* Assumes nop timeout is shorter than scsi cmd timeout */
2059         if (task->have_checked_conn)
2060                 goto done;
2061
2062         /*
2063          * Checking the transport already or nop from a cmd timeout still
2064          * running
2065          */
2066         if (conn->ping_task) {
2067                 task->have_checked_conn = true;
2068                 rc = BLK_EH_RESET_TIMER;
2069                 goto done;
2070         }
2071
2072         /* Make sure there is a transport check done */
2073         iscsi_send_nopout(conn, NULL);
2074         task->have_checked_conn = true;
2075         rc = BLK_EH_RESET_TIMER;
2076
2077 done:
2078         if (task)
2079                 task->last_timeout = jiffies;
2080         spin_unlock(&session->frwd_lock);
2081         ISCSI_DBG_EH(session, "return %s\n", rc == BLK_EH_RESET_TIMER ?
2082                      "timer reset" : "nh");
2083         return rc;
2084 }
2085
2086 static void iscsi_check_transport_timeouts(unsigned long data)
2087 {
2088         struct iscsi_conn *conn = (struct iscsi_conn *)data;
2089         struct iscsi_session *session = conn->session;
2090         unsigned long recv_timeout, next_timeout = 0, last_recv;
2091
2092         spin_lock(&session->frwd_lock);
2093         if (session->state != ISCSI_STATE_LOGGED_IN)
2094                 goto done;
2095
2096         recv_timeout = conn->recv_timeout;
2097         if (!recv_timeout)
2098                 goto done;
2099
2100         recv_timeout *= HZ;
2101         last_recv = conn->last_recv;
2102
2103         if (iscsi_has_ping_timed_out(conn)) {
2104                 iscsi_conn_printk(KERN_ERR, conn, "ping timeout of %d secs "
2105                                   "expired, recv timeout %d, last rx %lu, "
2106                                   "last ping %lu, now %lu\n",
2107                                   conn->ping_timeout, conn->recv_timeout,
2108                                   last_recv, conn->last_ping, jiffies);
2109                 spin_unlock(&session->frwd_lock);
2110                 iscsi_conn_failure(conn, ISCSI_ERR_NOP_TIMEDOUT);
2111                 return;
2112         }
2113
2114         if (time_before_eq(last_recv + recv_timeout, jiffies)) {
2115                 /* send a ping to try to provoke some traffic */
2116                 ISCSI_DBG_CONN(conn, "Sending nopout as ping\n");
2117                 iscsi_send_nopout(conn, NULL);
2118                 next_timeout = conn->last_ping + (conn->ping_timeout * HZ);
2119         } else
2120                 next_timeout = last_recv + recv_timeout;
2121
2122         ISCSI_DBG_CONN(conn, "Setting next tmo %lu\n", next_timeout);
2123         mod_timer(&conn->transport_timer, next_timeout);
2124 done:
2125         spin_unlock(&session->frwd_lock);
2126 }
2127
2128 static void iscsi_prep_abort_task_pdu(struct iscsi_task *task,
2129                                       struct iscsi_tm *hdr)
2130 {
2131         memset(hdr, 0, sizeof(*hdr));
2132         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2133         hdr->flags = ISCSI_TM_FUNC_ABORT_TASK & ISCSI_FLAG_TM_FUNC_MASK;
2134         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2135         hdr->lun = task->lun;
2136         hdr->rtt = task->hdr_itt;
2137         hdr->refcmdsn = task->cmdsn;
2138 }
2139
2140 int iscsi_eh_abort(struct scsi_cmnd *sc)
2141 {
2142         struct iscsi_cls_session *cls_session;
2143         struct iscsi_session *session;
2144         struct iscsi_conn *conn;
2145         struct iscsi_task *task;
2146         struct iscsi_tm *hdr;
2147         int rc, age;
2148
2149         cls_session = starget_to_session(scsi_target(sc->device));
2150         session = cls_session->dd_data;
2151
2152         ISCSI_DBG_EH(session, "aborting sc %p\n", sc);
2153
2154         mutex_lock(&session->eh_mutex);
2155         spin_lock_bh(&session->frwd_lock);
2156         /*
2157          * if session was ISCSI_STATE_IN_RECOVERY then we may not have
2158          * got the command.
2159          */
2160         if (!sc->SCp.ptr) {
2161                 ISCSI_DBG_EH(session, "sc never reached iscsi layer or "
2162                                       "it completed.\n");
2163                 spin_unlock_bh(&session->frwd_lock);
2164                 mutex_unlock(&session->eh_mutex);
2165                 return SUCCESS;
2166         }
2167
2168         /*
2169          * If we are not logged in or we have started a new session
2170          * then let the host reset code handle this
2171          */
2172         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN ||
2173             sc->SCp.phase != session->age) {
2174                 spin_unlock_bh(&session->frwd_lock);
2175                 mutex_unlock(&session->eh_mutex);
2176                 ISCSI_DBG_EH(session, "failing abort due to dropped "
2177                                   "session.\n");
2178                 return FAILED;
2179         }
2180
2181         conn = session->leadconn;
2182         conn->eh_abort_cnt++;
2183         age = session->age;
2184
2185         task = (struct iscsi_task *)sc->SCp.ptr;
2186         ISCSI_DBG_EH(session, "aborting [sc %p itt 0x%x]\n",
2187                      sc, task->itt);
2188
2189         /* task completed before time out */
2190         if (!task->sc) {
2191                 ISCSI_DBG_EH(session, "sc completed while abort in progress\n");
2192                 goto success;
2193         }
2194
2195         if (task->state == ISCSI_TASK_PENDING) {
2196                 fail_scsi_task(task, DID_ABORT);
2197                 goto success;
2198         }
2199
2200         /* only have one tmf outstanding at a time */
2201         if (conn->tmf_state != TMF_INITIAL)
2202                 goto failed;
2203         conn->tmf_state = TMF_QUEUED;
2204
2205         hdr = &conn->tmhdr;
2206         iscsi_prep_abort_task_pdu(task, hdr);
2207
2208         if (iscsi_exec_task_mgmt_fn(conn, hdr, age, session->abort_timeout)) {
2209                 rc = FAILED;
2210                 goto failed;
2211         }
2212
2213         switch (conn->tmf_state) {
2214         case TMF_SUCCESS:
2215                 spin_unlock_bh(&session->frwd_lock);
2216                 /*
2217                  * stop tx side incase the target had sent a abort rsp but
2218                  * the initiator was still writing out data.
2219                  */
2220                 iscsi_suspend_tx(conn);
2221                 /*
2222                  * we do not stop the recv side because targets have been
2223                  * good and have never sent us a successful tmf response
2224                  * then sent more data for the cmd.
2225                  */
2226                 spin_lock_bh(&session->frwd_lock);
2227                 fail_scsi_task(task, DID_ABORT);
2228                 conn->tmf_state = TMF_INITIAL;
2229                 memset(hdr, 0, sizeof(*hdr));
2230                 spin_unlock_bh(&session->frwd_lock);
2231                 iscsi_start_tx(conn);
2232                 goto success_unlocked;
2233         case TMF_TIMEDOUT:
2234                 spin_unlock_bh(&session->frwd_lock);
2235                 iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2236                 goto failed_unlocked;
2237         case TMF_NOT_FOUND:
2238                 if (!sc->SCp.ptr) {
2239                         conn->tmf_state = TMF_INITIAL;
2240                         memset(hdr, 0, sizeof(*hdr));
2241                         /* task completed before tmf abort response */
2242                         ISCSI_DBG_EH(session, "sc completed while abort in "
2243                                               "progress\n");
2244                         goto success;
2245                 }
2246                 /* fall through */
2247         default:
2248                 conn->tmf_state = TMF_INITIAL;
2249                 goto failed;
2250         }
2251
2252 success:
2253         spin_unlock_bh(&session->frwd_lock);
2254 success_unlocked:
2255         ISCSI_DBG_EH(session, "abort success [sc %p itt 0x%x]\n",
2256                      sc, task->itt);
2257         mutex_unlock(&session->eh_mutex);
2258         return SUCCESS;
2259
2260 failed:
2261         spin_unlock_bh(&session->frwd_lock);
2262 failed_unlocked:
2263         ISCSI_DBG_EH(session, "abort failed [sc %p itt 0x%x]\n", sc,
2264                      task ? task->itt : 0);
2265         mutex_unlock(&session->eh_mutex);
2266         return FAILED;
2267 }
2268 EXPORT_SYMBOL_GPL(iscsi_eh_abort);
2269
2270 static void iscsi_prep_lun_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
2271 {
2272         memset(hdr, 0, sizeof(*hdr));
2273         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2274         hdr->flags = ISCSI_TM_FUNC_LOGICAL_UNIT_RESET & ISCSI_FLAG_TM_FUNC_MASK;
2275         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2276         int_to_scsilun(sc->device->lun, &hdr->lun);
2277         hdr->rtt = RESERVED_ITT;
2278 }
2279
2280 int iscsi_eh_device_reset(struct scsi_cmnd *sc)
2281 {
2282         struct iscsi_cls_session *cls_session;
2283         struct iscsi_session *session;
2284         struct iscsi_conn *conn;
2285         struct iscsi_tm *hdr;
2286         int rc = FAILED;
2287
2288         cls_session = starget_to_session(scsi_target(sc->device));
2289         session = cls_session->dd_data;
2290
2291         ISCSI_DBG_EH(session, "LU Reset [sc %p lun %llu]\n", sc,
2292                      sc->device->lun);
2293
2294         mutex_lock(&session->eh_mutex);
2295         spin_lock_bh(&session->frwd_lock);
2296         /*
2297          * Just check if we are not logged in. We cannot check for
2298          * the phase because the reset could come from a ioctl.
2299          */
2300         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
2301                 goto unlock;
2302         conn = session->leadconn;
2303
2304         /* only have one tmf outstanding at a time */
2305         if (conn->tmf_state != TMF_INITIAL)
2306                 goto unlock;
2307         conn->tmf_state = TMF_QUEUED;
2308
2309         hdr = &conn->tmhdr;
2310         iscsi_prep_lun_reset_pdu(sc, hdr);
2311
2312         if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
2313                                     session->lu_reset_timeout)) {
2314                 rc = FAILED;
2315                 goto unlock;
2316         }
2317
2318         switch (conn->tmf_state) {
2319         case TMF_SUCCESS:
2320                 break;
2321         case TMF_TIMEDOUT:
2322                 spin_unlock_bh(&session->frwd_lock);
2323                 iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2324                 goto done;
2325         default:
2326                 conn->tmf_state = TMF_INITIAL;
2327                 goto unlock;
2328         }
2329
2330         rc = SUCCESS;
2331         spin_unlock_bh(&session->frwd_lock);
2332
2333         iscsi_suspend_tx(conn);
2334
2335         spin_lock_bh(&session->frwd_lock);
2336         memset(hdr, 0, sizeof(*hdr));
2337         fail_scsi_tasks(conn, sc->device->lun, DID_ERROR);
2338         conn->tmf_state = TMF_INITIAL;
2339         spin_unlock_bh(&session->frwd_lock);
2340
2341         iscsi_start_tx(conn);
2342         goto done;
2343
2344 unlock:
2345         spin_unlock_bh(&session->frwd_lock);
2346 done:
2347         ISCSI_DBG_EH(session, "dev reset result = %s\n",
2348                      rc == SUCCESS ? "SUCCESS" : "FAILED");
2349         mutex_unlock(&session->eh_mutex);
2350         return rc;
2351 }
2352 EXPORT_SYMBOL_GPL(iscsi_eh_device_reset);
2353
2354 void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
2355 {
2356         struct iscsi_session *session = cls_session->dd_data;
2357
2358         spin_lock_bh(&session->frwd_lock);
2359         if (session->state != ISCSI_STATE_LOGGED_IN) {
2360                 session->state = ISCSI_STATE_RECOVERY_FAILED;
2361                 if (session->leadconn)
2362                         wake_up(&session->leadconn->ehwait);
2363         }
2364         spin_unlock_bh(&session->frwd_lock);
2365 }
2366 EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
2367
2368 /**
2369  * iscsi_eh_session_reset - drop session and attempt relogin
2370  * @sc: scsi command
2371  *
2372  * This function will wait for a relogin, session termination from
2373  * userspace, or a recovery/replacement timeout.
2374  */
2375 int iscsi_eh_session_reset(struct scsi_cmnd *sc)
2376 {
2377         struct iscsi_cls_session *cls_session;
2378         struct iscsi_session *session;
2379         struct iscsi_conn *conn;
2380
2381         cls_session = starget_to_session(scsi_target(sc->device));
2382         session = cls_session->dd_data;
2383         conn = session->leadconn;
2384
2385         mutex_lock(&session->eh_mutex);
2386         spin_lock_bh(&session->frwd_lock);
2387         if (session->state == ISCSI_STATE_TERMINATE) {
2388 failed:
2389                 ISCSI_DBG_EH(session,
2390                              "failing session reset: Could not log back into "
2391                              "%s, %s [age %d]\n", session->targetname,
2392                              conn->persistent_address, session->age);
2393                 spin_unlock_bh(&session->frwd_lock);
2394                 mutex_unlock(&session->eh_mutex);
2395                 return FAILED;
2396         }
2397
2398         spin_unlock_bh(&session->frwd_lock);
2399         mutex_unlock(&session->eh_mutex);
2400         /*
2401          * we drop the lock here but the leadconn cannot be destoyed while
2402          * we are in the scsi eh
2403          */
2404         iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2405
2406         ISCSI_DBG_EH(session, "wait for relogin\n");
2407         wait_event_interruptible(conn->ehwait,
2408                                  session->state == ISCSI_STATE_TERMINATE ||
2409                                  session->state == ISCSI_STATE_LOGGED_IN ||
2410                                  session->state == ISCSI_STATE_RECOVERY_FAILED);
2411         if (signal_pending(current))
2412                 flush_signals(current);
2413
2414         mutex_lock(&session->eh_mutex);
2415         spin_lock_bh(&session->frwd_lock);
2416         if (session->state == ISCSI_STATE_LOGGED_IN) {
2417                 ISCSI_DBG_EH(session,
2418                              "session reset succeeded for %s,%s\n",
2419                              session->targetname, conn->persistent_address);
2420         } else
2421                 goto failed;
2422         spin_unlock_bh(&session->frwd_lock);
2423         mutex_unlock(&session->eh_mutex);
2424         return SUCCESS;
2425 }
2426 EXPORT_SYMBOL_GPL(iscsi_eh_session_reset);
2427
2428 static void iscsi_prep_tgt_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
2429 {
2430         memset(hdr, 0, sizeof(*hdr));
2431         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2432         hdr->flags = ISCSI_TM_FUNC_TARGET_WARM_RESET & ISCSI_FLAG_TM_FUNC_MASK;
2433         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2434         hdr->rtt = RESERVED_ITT;
2435 }
2436
2437 /**
2438  * iscsi_eh_target_reset - reset target
2439  * @sc: scsi command
2440  *
2441  * This will attempt to send a warm target reset.
2442  */
2443 int iscsi_eh_target_reset(struct scsi_cmnd *sc)
2444 {
2445         struct iscsi_cls_session *cls_session;
2446         struct iscsi_session *session;
2447         struct iscsi_conn *conn;
2448         struct iscsi_tm *hdr;
2449         int rc = FAILED;
2450
2451         cls_session = starget_to_session(scsi_target(sc->device));
2452         session = cls_session->dd_data;
2453
2454         ISCSI_DBG_EH(session, "tgt Reset [sc %p tgt %s]\n", sc,
2455                      session->targetname);
2456
2457         mutex_lock(&session->eh_mutex);
2458         spin_lock_bh(&session->frwd_lock);
2459         /*
2460          * Just check if we are not logged in. We cannot check for
2461          * the phase because the reset could come from a ioctl.
2462          */
2463         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
2464                 goto unlock;
2465         conn = session->leadconn;
2466
2467         /* only have one tmf outstanding at a time */
2468         if (conn->tmf_state != TMF_INITIAL)
2469                 goto unlock;
2470         conn->tmf_state = TMF_QUEUED;
2471
2472         hdr = &conn->tmhdr;
2473         iscsi_prep_tgt_reset_pdu(sc, hdr);
2474
2475         if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
2476                                     session->tgt_reset_timeout)) {
2477                 rc = FAILED;
2478                 goto unlock;
2479         }
2480
2481         switch (conn->tmf_state) {
2482         case TMF_SUCCESS:
2483                 break;
2484         case TMF_TIMEDOUT:
2485                 spin_unlock_bh(&session->frwd_lock);
2486                 iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2487                 goto done;
2488         default:
2489                 conn->tmf_state = TMF_INITIAL;
2490                 goto unlock;
2491         }
2492
2493         rc = SUCCESS;
2494         spin_unlock_bh(&session->frwd_lock);
2495
2496         iscsi_suspend_tx(conn);
2497
2498         spin_lock_bh(&session->frwd_lock);
2499         memset(hdr, 0, sizeof(*hdr));
2500         fail_scsi_tasks(conn, -1, DID_ERROR);
2501         conn->tmf_state = TMF_INITIAL;
2502         spin_unlock_bh(&session->frwd_lock);
2503
2504         iscsi_start_tx(conn);
2505         goto done;
2506
2507 unlock:
2508         spin_unlock_bh(&session->frwd_lock);
2509 done:
2510         ISCSI_DBG_EH(session, "tgt %s reset result = %s\n", session->targetname,
2511                      rc == SUCCESS ? "SUCCESS" : "FAILED");
2512         mutex_unlock(&session->eh_mutex);
2513         return rc;
2514 }
2515 EXPORT_SYMBOL_GPL(iscsi_eh_target_reset);
2516
2517 /**
2518  * iscsi_eh_recover_target - reset target and possibly the session
2519  * @sc: scsi command
2520  *
2521  * This will attempt to send a warm target reset. If that fails,
2522  * we will escalate to ERL0 session recovery.
2523  */
2524 int iscsi_eh_recover_target(struct scsi_cmnd *sc)
2525 {
2526         int rc;
2527
2528         rc = iscsi_eh_target_reset(sc);
2529         if (rc == FAILED)
2530                 rc = iscsi_eh_session_reset(sc);
2531         return rc;
2532 }
2533 EXPORT_SYMBOL_GPL(iscsi_eh_recover_target);
2534
2535 /*
2536  * Pre-allocate a pool of @max items of @item_size. By default, the pool
2537  * should be accessed via kfifo_{get,put} on q->queue.
2538  * Optionally, the caller can obtain the array of object pointers
2539  * by passing in a non-NULL @items pointer
2540  */
2541 int
2542 iscsi_pool_init(struct iscsi_pool *q, int max, void ***items, int item_size)
2543 {
2544         int i, num_arrays = 1;
2545
2546         memset(q, 0, sizeof(*q));
2547
2548         q->max = max;
2549
2550         /* If the user passed an items pointer, he wants a copy of
2551          * the array. */
2552         if (items)
2553                 num_arrays++;
2554         q->pool = kzalloc(num_arrays * max * sizeof(void*), GFP_KERNEL);
2555         if (q->pool == NULL)
2556                 return -ENOMEM;
2557
2558         kfifo_init(&q->queue, (void*)q->pool, max * sizeof(void*));
2559
2560         for (i = 0; i < max; i++) {
2561                 q->pool[i] = kzalloc(item_size, GFP_KERNEL);
2562                 if (q->pool[i] == NULL) {
2563                         q->max = i;
2564                         goto enomem;
2565                 }
2566                 kfifo_in(&q->queue, (void*)&q->pool[i], sizeof(void*));
2567         }
2568
2569         if (items) {
2570                 *items = q->pool + max;
2571                 memcpy(*items, q->pool, max * sizeof(void *));
2572         }
2573
2574         return 0;
2575
2576 enomem:
2577         iscsi_pool_free(q);
2578         return -ENOMEM;
2579 }
2580 EXPORT_SYMBOL_GPL(iscsi_pool_init);
2581
2582 void iscsi_pool_free(struct iscsi_pool *q)
2583 {
2584         int i;
2585
2586         for (i = 0; i < q->max; i++)
2587                 kfree(q->pool[i]);
2588         kfree(q->pool);
2589 }
2590 EXPORT_SYMBOL_GPL(iscsi_pool_free);
2591
2592 /**
2593  * iscsi_host_add - add host to system
2594  * @shost: scsi host
2595  * @pdev: parent device
2596  *
2597  * This should be called by partial offload and software iscsi drivers
2598  * to add a host to the system.
2599  */
2600 int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev)
2601 {
2602         if (!shost->can_queue)
2603                 shost->can_queue = ISCSI_DEF_XMIT_CMDS_MAX;
2604
2605         if (!shost->cmd_per_lun)
2606                 shost->cmd_per_lun = ISCSI_DEF_CMD_PER_LUN;
2607
2608         if (!shost->transportt->eh_timed_out)
2609                 shost->transportt->eh_timed_out = iscsi_eh_cmd_timed_out;
2610         return scsi_add_host(shost, pdev);
2611 }
2612 EXPORT_SYMBOL_GPL(iscsi_host_add);
2613
2614 /**
2615  * iscsi_host_alloc - allocate a host and driver data
2616  * @sht: scsi host template
2617  * @dd_data_size: driver host data size
2618  * @xmit_can_sleep: bool indicating if LLD will queue IO from a work queue
2619  *
2620  * This should be called by partial offload and software iscsi drivers.
2621  * To access the driver specific memory use the iscsi_host_priv() macro.
2622  */
2623 struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
2624                                    int dd_data_size, bool xmit_can_sleep)
2625 {
2626         struct Scsi_Host *shost;
2627         struct iscsi_host *ihost;
2628
2629         shost = scsi_host_alloc(sht, sizeof(struct iscsi_host) + dd_data_size);
2630         if (!shost)
2631                 return NULL;
2632         ihost = shost_priv(shost);
2633
2634         if (xmit_can_sleep) {
2635                 snprintf(ihost->workq_name, sizeof(ihost->workq_name),
2636                         "iscsi_q_%d", shost->host_no);
2637                 ihost->workq = create_singlethread_workqueue(ihost->workq_name);
2638                 if (!ihost->workq)
2639                         goto free_host;
2640         }
2641
2642         spin_lock_init(&ihost->lock);
2643         ihost->state = ISCSI_HOST_SETUP;
2644         ihost->num_sessions = 0;
2645         init_waitqueue_head(&ihost->session_removal_wq);
2646         return shost;
2647
2648 free_host:
2649         scsi_host_put(shost);
2650         return NULL;
2651 }
2652 EXPORT_SYMBOL_GPL(iscsi_host_alloc);
2653
2654 static void iscsi_notify_host_removed(struct iscsi_cls_session *cls_session)
2655 {
2656         iscsi_session_failure(cls_session->dd_data, ISCSI_ERR_INVALID_HOST);
2657 }
2658
2659 /**
2660  * iscsi_host_remove - remove host and sessions
2661  * @shost: scsi host
2662  *
2663  * If there are any sessions left, this will initiate the removal and wait
2664  * for the completion.
2665  */
2666 void iscsi_host_remove(struct Scsi_Host *shost)
2667 {
2668         struct iscsi_host *ihost = shost_priv(shost);
2669         unsigned long flags;
2670
2671         spin_lock_irqsave(&ihost->lock, flags);
2672         ihost->state = ISCSI_HOST_REMOVED;
2673         spin_unlock_irqrestore(&ihost->lock, flags);
2674
2675         iscsi_host_for_each_session(shost, iscsi_notify_host_removed);
2676         wait_event_interruptible(ihost->session_removal_wq,
2677                                  ihost->num_sessions == 0);
2678         if (signal_pending(current))
2679                 flush_signals(current);
2680
2681         scsi_remove_host(shost);
2682         if (ihost->workq)
2683                 destroy_workqueue(ihost->workq);
2684 }
2685 EXPORT_SYMBOL_GPL(iscsi_host_remove);
2686
2687 void iscsi_host_free(struct Scsi_Host *shost)
2688 {
2689         struct iscsi_host *ihost = shost_priv(shost);
2690
2691         kfree(ihost->netdev);
2692         kfree(ihost->hwaddress);
2693         kfree(ihost->initiatorname);
2694         scsi_host_put(shost);
2695 }
2696 EXPORT_SYMBOL_GPL(iscsi_host_free);
2697
2698 static void iscsi_host_dec_session_cnt(struct Scsi_Host *shost)
2699 {
2700         struct iscsi_host *ihost = shost_priv(shost);
2701         unsigned long flags;
2702
2703         shost = scsi_host_get(shost);
2704         if (!shost) {
2705                 printk(KERN_ERR "Invalid state. Cannot notify host removal "
2706                       "of session teardown event because host already "
2707                       "removed.\n");
2708                 return;
2709         }
2710
2711         spin_lock_irqsave(&ihost->lock, flags);
2712         ihost->num_sessions--;
2713         if (ihost->num_sessions == 0)
2714                 wake_up(&ihost->session_removal_wq);
2715         spin_unlock_irqrestore(&ihost->lock, flags);
2716         scsi_host_put(shost);
2717 }
2718
2719 /**
2720  * iscsi_session_setup - create iscsi cls session and host and session
2721  * @iscsit: iscsi transport template
2722  * @shost: scsi host
2723  * @cmds_max: session can queue
2724  * @cmd_task_size: LLD task private data size
2725  * @initial_cmdsn: initial CmdSN
2726  *
2727  * This can be used by software iscsi_transports that allocate
2728  * a session per scsi host.
2729  *
2730  * Callers should set cmds_max to the largest total numer (mgmt + scsi) of
2731  * tasks they support. The iscsi layer reserves ISCSI_MGMT_CMDS_MAX tasks
2732  * for nop handling and login/logout requests.
2733  */
2734 struct iscsi_cls_session *
2735 iscsi_session_setup(struct iscsi_transport *iscsit, struct Scsi_Host *shost,
2736                     uint16_t cmds_max, int dd_size, int cmd_task_size,
2737                     uint32_t initial_cmdsn, unsigned int id)
2738 {
2739         struct iscsi_host *ihost = shost_priv(shost);
2740         struct iscsi_session *session;
2741         struct iscsi_cls_session *cls_session;
2742         int cmd_i, scsi_cmds, total_cmds = cmds_max;
2743         unsigned long flags;
2744
2745         spin_lock_irqsave(&ihost->lock, flags);
2746         if (ihost->state == ISCSI_HOST_REMOVED) {
2747                 spin_unlock_irqrestore(&ihost->lock, flags);
2748                 return NULL;
2749         }
2750         ihost->num_sessions++;
2751         spin_unlock_irqrestore(&ihost->lock, flags);
2752
2753         if (!total_cmds)
2754                 total_cmds = ISCSI_DEF_XMIT_CMDS_MAX;
2755         /*
2756          * The iscsi layer needs some tasks for nop handling and tmfs,
2757          * so the cmds_max must at least be greater than ISCSI_MGMT_CMDS_MAX
2758          * + 1 command for scsi IO.
2759          */
2760         if (total_cmds < ISCSI_TOTAL_CMDS_MIN) {
2761                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2762                        "must be a power of two that is at least %d.\n",
2763                        total_cmds, ISCSI_TOTAL_CMDS_MIN);
2764                 goto dec_session_count;
2765         }
2766
2767         if (total_cmds > ISCSI_TOTAL_CMDS_MAX) {
2768                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2769                        "must be a power of 2 less than or equal to %d.\n",
2770                        cmds_max, ISCSI_TOTAL_CMDS_MAX);
2771                 total_cmds = ISCSI_TOTAL_CMDS_MAX;
2772         }
2773
2774         if (!is_power_of_2(total_cmds)) {
2775                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2776                        "must be a power of 2.\n", total_cmds);
2777                 total_cmds = rounddown_pow_of_two(total_cmds);
2778                 if (total_cmds < ISCSI_TOTAL_CMDS_MIN)
2779                         return NULL;
2780                 printk(KERN_INFO "iscsi: Rounding can_queue to %d.\n",
2781                        total_cmds);
2782         }
2783         scsi_cmds = total_cmds - ISCSI_MGMT_CMDS_MAX;
2784
2785         cls_session = iscsi_alloc_session(shost, iscsit,
2786                                           sizeof(struct iscsi_session) +
2787                                           dd_size);
2788         if (!cls_session)
2789                 goto dec_session_count;
2790         session = cls_session->dd_data;
2791         session->cls_session = cls_session;
2792         session->host = shost;
2793         session->state = ISCSI_STATE_FREE;
2794         session->fast_abort = 1;
2795         session->tgt_reset_timeout = 30;
2796         session->lu_reset_timeout = 15;
2797         session->abort_timeout = 10;
2798         session->scsi_cmds_max = scsi_cmds;
2799         session->cmds_max = total_cmds;
2800         session->queued_cmdsn = session->cmdsn = initial_cmdsn;
2801         session->exp_cmdsn = initial_cmdsn + 1;
2802         session->max_cmdsn = initial_cmdsn + 1;
2803         session->max_r2t = 1;
2804         session->tt = iscsit;
2805         session->dd_data = cls_session->dd_data + sizeof(*session);
2806
2807         mutex_init(&session->eh_mutex);
2808         spin_lock_init(&session->frwd_lock);
2809         spin_lock_init(&session->back_lock);
2810
2811         /* initialize SCSI PDU commands pool */
2812         if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
2813                             (void***)&session->cmds,
2814                             cmd_task_size + sizeof(struct iscsi_task)))
2815                 goto cmdpool_alloc_fail;
2816
2817         /* pre-format cmds pool with ITT */
2818         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
2819                 struct iscsi_task *task = session->cmds[cmd_i];
2820
2821                 if (cmd_task_size)
2822                         task->dd_data = &task[1];
2823                 task->itt = cmd_i;
2824                 task->state = ISCSI_TASK_FREE;
2825                 INIT_LIST_HEAD(&task->running);
2826         }
2827
2828         if (!try_module_get(iscsit->owner))
2829                 goto module_get_fail;
2830
2831         if (iscsi_add_session(cls_session, id))
2832                 goto cls_session_fail;
2833
2834         return cls_session;
2835
2836 cls_session_fail:
2837         module_put(iscsit->owner);
2838 module_get_fail:
2839         iscsi_pool_free(&session->cmdpool);
2840 cmdpool_alloc_fail:
2841         iscsi_free_session(cls_session);
2842 dec_session_count:
2843         iscsi_host_dec_session_cnt(shost);
2844         return NULL;
2845 }
2846 EXPORT_SYMBOL_GPL(iscsi_session_setup);
2847
2848 /**
2849  * iscsi_session_teardown - destroy session, host, and cls_session
2850  * @cls_session: iscsi session
2851  *
2852  * The driver must have called iscsi_remove_session before
2853  * calling this.
2854  */
2855 void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
2856 {
2857         struct iscsi_session *session = cls_session->dd_data;
2858         struct module *owner = cls_session->transport->owner;
2859         struct Scsi_Host *shost = session->host;
2860
2861         iscsi_pool_free(&session->cmdpool);
2862
2863         kfree(session->password);
2864         kfree(session->password_in);
2865         kfree(session->username);
2866         kfree(session->username_in);
2867         kfree(session->targetname);
2868         kfree(session->targetalias);
2869         kfree(session->initiatorname);
2870         kfree(session->boot_root);
2871         kfree(session->boot_nic);
2872         kfree(session->boot_target);
2873         kfree(session->ifacename);
2874         kfree(session->portal_type);
2875         kfree(session->discovery_parent_type);
2876
2877         iscsi_destroy_session(cls_session);
2878         iscsi_host_dec_session_cnt(shost);
2879         module_put(owner);
2880 }
2881 EXPORT_SYMBOL_GPL(iscsi_session_teardown);
2882
2883 /**
2884  * iscsi_conn_setup - create iscsi_cls_conn and iscsi_conn
2885  * @cls_session: iscsi_cls_session
2886  * @dd_size: private driver data size
2887  * @conn_idx: cid
2888  */
2889 struct iscsi_cls_conn *
2890 iscsi_conn_setup(struct iscsi_cls_session *cls_session, int dd_size,
2891                  uint32_t conn_idx)
2892 {
2893         struct iscsi_session *session = cls_session->dd_data;
2894         struct iscsi_conn *conn;
2895         struct iscsi_cls_conn *cls_conn;
2896         char *data;
2897
2898         cls_conn = iscsi_create_conn(cls_session, sizeof(*conn) + dd_size,
2899                                      conn_idx);
2900         if (!cls_conn)
2901                 return NULL;
2902         conn = cls_conn->dd_data;
2903         memset(conn, 0, sizeof(*conn) + dd_size);
2904
2905         conn->dd_data = cls_conn->dd_data + sizeof(*conn);
2906         conn->session = session;
2907         conn->cls_conn = cls_conn;
2908         conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
2909         conn->id = conn_idx;
2910         conn->exp_statsn = 0;
2911         conn->tmf_state = TMF_INITIAL;
2912
2913         init_timer(&conn->transport_timer);
2914         conn->transport_timer.data = (unsigned long)conn;
2915         conn->transport_timer.function = iscsi_check_transport_timeouts;
2916
2917         INIT_LIST_HEAD(&conn->mgmtqueue);
2918         INIT_LIST_HEAD(&conn->cmdqueue);
2919         INIT_LIST_HEAD(&conn->requeue);
2920         INIT_WORK(&conn->xmitwork, iscsi_xmitworker);
2921
2922         /* allocate login_task used for the login/text sequences */
2923         spin_lock_bh(&session->frwd_lock);
2924         if (!kfifo_out(&session->cmdpool.queue,
2925                          (void*)&conn->login_task,
2926                          sizeof(void*))) {
2927                 spin_unlock_bh(&session->frwd_lock);
2928                 goto login_task_alloc_fail;
2929         }
2930         spin_unlock_bh(&session->frwd_lock);
2931
2932         data = (char *) __get_free_pages(GFP_KERNEL,
2933                                          get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
2934         if (!data)
2935                 goto login_task_data_alloc_fail;
2936         conn->login_task->data = conn->data = data;
2937
2938         init_timer(&conn->tmf_timer);
2939         init_waitqueue_head(&conn->ehwait);
2940
2941         return cls_conn;
2942
2943 login_task_data_alloc_fail:
2944         kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
2945                     sizeof(void*));
2946 login_task_alloc_fail:
2947         iscsi_destroy_conn(cls_conn);
2948         return NULL;
2949 }
2950 EXPORT_SYMBOL_GPL(iscsi_conn_setup);
2951
2952 /**
2953  * iscsi_conn_teardown - teardown iscsi connection
2954  * cls_conn: iscsi class connection
2955  *
2956  * TODO: we may need to make this into a two step process
2957  * like scsi-mls remove + put host
2958  */
2959 void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
2960 {
2961         struct iscsi_conn *conn = cls_conn->dd_data;
2962         struct iscsi_session *session = conn->session;
2963         unsigned long flags;
2964
2965         del_timer_sync(&conn->transport_timer);
2966
2967         spin_lock_bh(&session->frwd_lock);
2968         conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
2969         if (session->leadconn == conn) {
2970                 /*
2971                  * leading connection? then give up on recovery.
2972                  */
2973                 session->state = ISCSI_STATE_TERMINATE;
2974                 wake_up(&conn->ehwait);
2975         }
2976         spin_unlock_bh(&session->frwd_lock);
2977
2978         /*
2979          * Block until all in-progress commands for this connection
2980          * time out or fail.
2981          */
2982         for (;;) {
2983                 spin_lock_irqsave(session->host->host_lock, flags);
2984                 if (!atomic_read(&session->host->host_busy)) { /* OK for ERL == 0 */
2985                         spin_unlock_irqrestore(session->host->host_lock, flags);
2986                         break;
2987                 }
2988                 spin_unlock_irqrestore(session->host->host_lock, flags);
2989                 msleep_interruptible(500);
2990                 iscsi_conn_printk(KERN_INFO, conn, "iscsi conn_destroy(): "
2991                                   "host_busy %d host_failed %d\n",
2992                                   atomic_read(&session->host->host_busy),
2993                                   session->host->host_failed);
2994                 /*
2995                  * force eh_abort() to unblock
2996                  */
2997                 wake_up(&conn->ehwait);
2998         }
2999
3000         /* flush queued up work because we free the connection below */
3001         iscsi_suspend_tx(conn);
3002
3003         spin_lock_bh(&session->frwd_lock);
3004         free_pages((unsigned long) conn->data,
3005                    get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
3006         kfree(conn->persistent_address);
3007         kfree(conn->local_ipaddr);
3008         /* regular RX path uses back_lock */
3009         spin_lock_bh(&session->back_lock);
3010         kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
3011                     sizeof(void*));
3012         spin_unlock_bh(&session->back_lock);
3013         if (session->leadconn == conn)
3014                 session->leadconn = NULL;
3015         spin_unlock_bh(&session->frwd_lock);
3016
3017         iscsi_destroy_conn(cls_conn);
3018 }
3019 EXPORT_SYMBOL_GPL(iscsi_conn_teardown);
3020
3021 int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
3022 {
3023         struct iscsi_conn *conn = cls_conn->dd_data;
3024         struct iscsi_session *session = conn->session;
3025
3026         if (!session) {
3027                 iscsi_conn_printk(KERN_ERR, conn,
3028                                   "can't start unbound connection\n");
3029                 return -EPERM;
3030         }
3031
3032         if ((session->imm_data_en || !session->initial_r2t_en) &&
3033              session->first_burst > session->max_burst) {
3034                 iscsi_conn_printk(KERN_INFO, conn, "invalid burst lengths: "
3035                                   "first_burst %d max_burst %d\n",
3036                                   session->first_burst, session->max_burst);
3037                 return -EINVAL;
3038         }
3039
3040         if (conn->ping_timeout && !conn->recv_timeout) {
3041                 iscsi_conn_printk(KERN_ERR, conn, "invalid recv timeout of "
3042                                   "zero. Using 5 seconds\n.");
3043                 conn->recv_timeout = 5;
3044         }
3045
3046         if (conn->recv_timeout && !conn->ping_timeout) {
3047                 iscsi_conn_printk(KERN_ERR, conn, "invalid ping timeout of "
3048                                   "zero. Using 5 seconds.\n");
3049                 conn->ping_timeout = 5;
3050         }
3051
3052         spin_lock_bh(&session->frwd_lock);
3053         conn->c_stage = ISCSI_CONN_STARTED;
3054         session->state = ISCSI_STATE_LOGGED_IN;
3055         session->queued_cmdsn = session->cmdsn;
3056
3057         conn->last_recv = jiffies;
3058         conn->last_ping = jiffies;
3059         if (conn->recv_timeout && conn->ping_timeout)
3060                 mod_timer(&conn->transport_timer,
3061                           jiffies + (conn->recv_timeout * HZ));
3062
3063         switch(conn->stop_stage) {
3064         case STOP_CONN_RECOVER:
3065                 /*
3066                  * unblock eh_abort() if it is blocked. re-try all
3067                  * commands after successful recovery
3068                  */
3069                 conn->stop_stage = 0;
3070                 conn->tmf_state = TMF_INITIAL;
3071                 session->age++;
3072                 if (session->age == 16)
3073                         session->age = 0;
3074                 break;
3075         case STOP_CONN_TERM:
3076                 conn->stop_stage = 0;
3077                 break;
3078         default:
3079                 break;
3080         }
3081         spin_unlock_bh(&session->frwd_lock);
3082
3083         iscsi_unblock_session(session->cls_session);
3084         wake_up(&conn->ehwait);
3085         return 0;
3086 }
3087 EXPORT_SYMBOL_GPL(iscsi_conn_start);
3088
3089 static void
3090 fail_mgmt_tasks(struct iscsi_session *session, struct iscsi_conn *conn)
3091 {
3092         struct iscsi_task *task;
3093         int i, state;
3094
3095         for (i = 0; i < conn->session->cmds_max; i++) {
3096                 task = conn->session->cmds[i];
3097                 if (task->sc)
3098                         continue;
3099
3100                 if (task->state == ISCSI_TASK_FREE)
3101                         continue;
3102
3103                 ISCSI_DBG_SESSION(conn->session,
3104                                   "failing mgmt itt 0x%x state %d\n",
3105                                   task->itt, task->state);
3106                 state = ISCSI_TASK_ABRT_SESS_RECOV;
3107                 if (task->state == ISCSI_TASK_PENDING)
3108                         state = ISCSI_TASK_COMPLETED;
3109                 iscsi_complete_task(task, state);
3110
3111         }
3112 }
3113
3114 static void iscsi_start_session_recovery(struct iscsi_session *session,
3115                                          struct iscsi_conn *conn, int flag)
3116 {
3117         int old_stop_stage;
3118
3119         mutex_lock(&session->eh_mutex);
3120         spin_lock_bh(&session->frwd_lock);
3121         if (conn->stop_stage == STOP_CONN_TERM) {
3122                 spin_unlock_bh(&session->frwd_lock);
3123                 mutex_unlock(&session->eh_mutex);
3124                 return;
3125         }
3126
3127         /*
3128          * When this is called for the in_login state, we only want to clean
3129          * up the login task and connection. We do not need to block and set
3130          * the recovery state again
3131          */
3132         if (flag == STOP_CONN_TERM)
3133                 session->state = ISCSI_STATE_TERMINATE;
3134         else if (conn->stop_stage != STOP_CONN_RECOVER)
3135                 session->state = ISCSI_STATE_IN_RECOVERY;
3136
3137         old_stop_stage = conn->stop_stage;
3138         conn->stop_stage = flag;
3139         spin_unlock_bh(&session->frwd_lock);
3140
3141         del_timer_sync(&conn->transport_timer);
3142         iscsi_suspend_tx(conn);
3143
3144         spin_lock_bh(&session->frwd_lock);
3145         conn->c_stage = ISCSI_CONN_STOPPED;
3146         spin_unlock_bh(&session->frwd_lock);
3147
3148         /*
3149          * for connection level recovery we should not calculate
3150          * header digest. conn->hdr_size used for optimization
3151          * in hdr_extract() and will be re-negotiated at
3152          * set_param() time.
3153          */
3154         if (flag == STOP_CONN_RECOVER) {
3155                 conn->hdrdgst_en = 0;
3156                 conn->datadgst_en = 0;
3157                 if (session->state == ISCSI_STATE_IN_RECOVERY &&
3158                     old_stop_stage != STOP_CONN_RECOVER) {
3159                         ISCSI_DBG_SESSION(session, "blocking session\n");
3160                         iscsi_block_session(session->cls_session);
3161                 }
3162         }
3163
3164         /*
3165          * flush queues.
3166          */
3167         spin_lock_bh(&session->frwd_lock);
3168         fail_scsi_tasks(conn, -1, DID_TRANSPORT_DISRUPTED);
3169         fail_mgmt_tasks(session, conn);
3170         memset(&conn->tmhdr, 0, sizeof(conn->tmhdr));
3171         spin_unlock_bh(&session->frwd_lock);
3172         mutex_unlock(&session->eh_mutex);
3173 }
3174
3175 void iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
3176 {
3177         struct iscsi_conn *conn = cls_conn->dd_data;
3178         struct iscsi_session *session = conn->session;
3179
3180         switch (flag) {
3181         case STOP_CONN_RECOVER:
3182         case STOP_CONN_TERM:
3183                 iscsi_start_session_recovery(session, conn, flag);
3184                 break;
3185         default:
3186                 iscsi_conn_printk(KERN_ERR, conn,
3187                                   "invalid stop flag %d\n", flag);
3188         }
3189 }
3190 EXPORT_SYMBOL_GPL(iscsi_conn_stop);
3191
3192 int iscsi_conn_bind(struct iscsi_cls_session *cls_session,
3193                     struct iscsi_cls_conn *cls_conn, int is_leading)
3194 {
3195         struct iscsi_session *session = cls_session->dd_data;
3196         struct iscsi_conn *conn = cls_conn->dd_data;
3197
3198         spin_lock_bh(&session->frwd_lock);
3199         if (is_leading)
3200                 session->leadconn = conn;
3201         spin_unlock_bh(&session->frwd_lock);
3202
3203         /*
3204          * Unblock xmitworker(), Login Phase will pass through.
3205          */
3206         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
3207         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
3208         return 0;
3209 }
3210 EXPORT_SYMBOL_GPL(iscsi_conn_bind);
3211
3212 int iscsi_switch_str_param(char **param, char *new_val_buf)
3213 {
3214         char *new_val;
3215
3216         if (*param) {
3217                 if (!strcmp(*param, new_val_buf))
3218                         return 0;
3219         }
3220
3221         new_val = kstrdup(new_val_buf, GFP_NOIO);
3222         if (!new_val)
3223                 return -ENOMEM;
3224
3225         kfree(*param);
3226         *param = new_val;
3227         return 0;
3228 }
3229 EXPORT_SYMBOL_GPL(iscsi_switch_str_param);
3230
3231 int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
3232                     enum iscsi_param param, char *buf, int buflen)
3233 {
3234         struct iscsi_conn *conn = cls_conn->dd_data;
3235         struct iscsi_session *session = conn->session;
3236         int val;
3237
3238         switch(param) {
3239         case ISCSI_PARAM_FAST_ABORT:
3240                 sscanf(buf, "%d", &session->fast_abort);
3241                 break;
3242         case ISCSI_PARAM_ABORT_TMO:
3243                 sscanf(buf, "%d", &session->abort_timeout);
3244                 break;
3245         case ISCSI_PARAM_LU_RESET_TMO:
3246                 sscanf(buf, "%d", &session->lu_reset_timeout);
3247                 break;
3248         case ISCSI_PARAM_TGT_RESET_TMO:
3249                 sscanf(buf, "%d", &session->tgt_reset_timeout);
3250                 break;
3251         case ISCSI_PARAM_PING_TMO:
3252                 sscanf(buf, "%d", &conn->ping_timeout);
3253                 break;
3254         case ISCSI_PARAM_RECV_TMO:
3255                 sscanf(buf, "%d", &conn->recv_timeout);
3256                 break;
3257         case ISCSI_PARAM_MAX_RECV_DLENGTH:
3258                 sscanf(buf, "%d", &conn->max_recv_dlength);
3259                 break;
3260         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3261                 sscanf(buf, "%d", &conn->max_xmit_dlength);
3262                 break;
3263         case ISCSI_PARAM_HDRDGST_EN:
3264                 sscanf(buf, "%d", &conn->hdrdgst_en);
3265                 break;
3266         case ISCSI_PARAM_DATADGST_EN:
3267                 sscanf(buf, "%d", &conn->datadgst_en);
3268                 break;
3269         case ISCSI_PARAM_INITIAL_R2T_EN:
3270                 sscanf(buf, "%d", &session->initial_r2t_en);
3271                 break;
3272         case ISCSI_PARAM_MAX_R2T:
3273                 sscanf(buf, "%hu", &session->max_r2t);
3274                 break;
3275         case ISCSI_PARAM_IMM_DATA_EN:
3276                 sscanf(buf, "%d", &session->imm_data_en);
3277                 break;
3278         case ISCSI_PARAM_FIRST_BURST:
3279                 sscanf(buf, "%d", &session->first_burst);
3280                 break;
3281         case ISCSI_PARAM_MAX_BURST:
3282                 sscanf(buf, "%d", &session->max_burst);
3283                 break;
3284         case ISCSI_PARAM_PDU_INORDER_EN:
3285                 sscanf(buf, "%d", &session->pdu_inorder_en);
3286                 break;
3287         case ISCSI_PARAM_DATASEQ_INORDER_EN:
3288                 sscanf(buf, "%d", &session->dataseq_inorder_en);
3289                 break;
3290         case ISCSI_PARAM_ERL:
3291                 sscanf(buf, "%d", &session->erl);
3292                 break;
3293         case ISCSI_PARAM_EXP_STATSN:
3294                 sscanf(buf, "%u", &conn->exp_statsn);
3295                 break;
3296         case ISCSI_PARAM_USERNAME:
3297                 return iscsi_switch_str_param(&session->username, buf);
3298         case ISCSI_PARAM_USERNAME_IN:
3299                 return iscsi_switch_str_param(&session->username_in, buf);
3300         case ISCSI_PARAM_PASSWORD:
3301                 return iscsi_switch_str_param(&session->password, buf);
3302         case ISCSI_PARAM_PASSWORD_IN:
3303                 return iscsi_switch_str_param(&session->password_in, buf);
3304         case ISCSI_PARAM_TARGET_NAME:
3305                 return iscsi_switch_str_param(&session->targetname, buf);
3306         case ISCSI_PARAM_TARGET_ALIAS:
3307                 return iscsi_switch_str_param(&session->targetalias, buf);
3308         case ISCSI_PARAM_TPGT:
3309                 sscanf(buf, "%d", &session->tpgt);
3310                 break;
3311         case ISCSI_PARAM_PERSISTENT_PORT:
3312                 sscanf(buf, "%d", &conn->persistent_port);
3313                 break;
3314         case ISCSI_PARAM_PERSISTENT_ADDRESS:
3315                 return iscsi_switch_str_param(&conn->persistent_address, buf);
3316         case ISCSI_PARAM_IFACE_NAME:
3317                 return iscsi_switch_str_param(&session->ifacename, buf);
3318         case ISCSI_PARAM_INITIATOR_NAME:
3319                 return iscsi_switch_str_param(&session->initiatorname, buf);
3320         case ISCSI_PARAM_BOOT_ROOT:
3321                 return iscsi_switch_str_param(&session->boot_root, buf);
3322         case ISCSI_PARAM_BOOT_NIC:
3323                 return iscsi_switch_str_param(&session->boot_nic, buf);
3324         case ISCSI_PARAM_BOOT_TARGET:
3325                 return iscsi_switch_str_param(&session->boot_target, buf);
3326         case ISCSI_PARAM_PORTAL_TYPE:
3327                 return iscsi_switch_str_param(&session->portal_type, buf);
3328         case ISCSI_PARAM_DISCOVERY_PARENT_TYPE:
3329                 return iscsi_switch_str_param(&session->discovery_parent_type,
3330                                               buf);
3331         case ISCSI_PARAM_DISCOVERY_SESS:
3332                 sscanf(buf, "%d", &val);
3333                 session->discovery_sess = !!val;
3334                 break;
3335         case ISCSI_PARAM_LOCAL_IPADDR:
3336                 return iscsi_switch_str_param(&conn->local_ipaddr, buf);
3337         default:
3338                 return -ENOSYS;
3339         }
3340
3341         return 0;
3342 }
3343 EXPORT_SYMBOL_GPL(iscsi_set_param);
3344
3345 int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
3346                             enum iscsi_param param, char *buf)
3347 {
3348         struct iscsi_session *session = cls_session->dd_data;
3349         int len;
3350
3351         switch(param) {
3352         case ISCSI_PARAM_FAST_ABORT:
3353                 len = sprintf(buf, "%d\n", session->fast_abort);
3354                 break;
3355         case ISCSI_PARAM_ABORT_TMO:
3356                 len = sprintf(buf, "%d\n", session->abort_timeout);
3357                 break;
3358         case ISCSI_PARAM_LU_RESET_TMO:
3359                 len = sprintf(buf, "%d\n", session->lu_reset_timeout);
3360                 break;
3361         case ISCSI_PARAM_TGT_RESET_TMO:
3362                 len = sprintf(buf, "%d\n", session->tgt_reset_timeout);
3363                 break;
3364         case ISCSI_PARAM_INITIAL_R2T_EN:
3365                 len = sprintf(buf, "%d\n", session->initial_r2t_en);
3366                 break;
3367         case ISCSI_PARAM_MAX_R2T:
3368                 len = sprintf(buf, "%hu\n", session->max_r2t);
3369                 break;
3370         case ISCSI_PARAM_IMM_DATA_EN:
3371                 len = sprintf(buf, "%d\n", session->imm_data_en);
3372                 break;
3373         case ISCSI_PARAM_FIRST_BURST:
3374                 len = sprintf(buf, "%u\n", session->first_burst);
3375                 break;
3376         case ISCSI_PARAM_MAX_BURST:
3377                 len = sprintf(buf, "%u\n", session->max_burst);
3378                 break;
3379         case ISCSI_PARAM_PDU_INORDER_EN:
3380                 len = sprintf(buf, "%d\n", session->pdu_inorder_en);
3381                 break;
3382         case ISCSI_PARAM_DATASEQ_INORDER_EN:
3383                 len = sprintf(buf, "%d\n", session->dataseq_inorder_en);
3384                 break;
3385         case ISCSI_PARAM_DEF_TASKMGMT_TMO:
3386                 len = sprintf(buf, "%d\n", session->def_taskmgmt_tmo);
3387                 break;
3388         case ISCSI_PARAM_ERL:
3389                 len = sprintf(buf, "%d\n", session->erl);
3390                 break;
3391         case ISCSI_PARAM_TARGET_NAME:
3392                 len = sprintf(buf, "%s\n", session->targetname);
3393                 break;
3394         case ISCSI_PARAM_TARGET_ALIAS:
3395                 len = sprintf(buf, "%s\n", session->targetalias);
3396                 break;
3397         case ISCSI_PARAM_TPGT:
3398                 len = sprintf(buf, "%d\n", session->tpgt);
3399                 break;
3400         case ISCSI_PARAM_USERNAME:
3401                 len = sprintf(buf, "%s\n", session->username);
3402                 break;
3403         case ISCSI_PARAM_USERNAME_IN:
3404                 len = sprintf(buf, "%s\n", session->username_in);
3405                 break;
3406         case ISCSI_PARAM_PASSWORD:
3407                 len = sprintf(buf, "%s\n", session->password);
3408                 break;
3409         case ISCSI_PARAM_PASSWORD_IN:
3410                 len = sprintf(buf, "%s\n", session->password_in);
3411                 break;
3412         case ISCSI_PARAM_IFACE_NAME:
3413                 len = sprintf(buf, "%s\n", session->ifacename);
3414                 break;
3415         case ISCSI_PARAM_INITIATOR_NAME:
3416                 len = sprintf(buf, "%s\n", session->initiatorname);
3417                 break;
3418         case ISCSI_PARAM_BOOT_ROOT:
3419                 len = sprintf(buf, "%s\n", session->boot_root);
3420                 break;
3421         case ISCSI_PARAM_BOOT_NIC:
3422                 len = sprintf(buf, "%s\n", session->boot_nic);
3423                 break;
3424         case ISCSI_PARAM_BOOT_TARGET:
3425                 len = sprintf(buf, "%s\n", session->boot_target);
3426                 break;
3427         case ISCSI_PARAM_AUTO_SND_TGT_DISABLE:
3428                 len = sprintf(buf, "%u\n", session->auto_snd_tgt_disable);
3429                 break;
3430         case ISCSI_PARAM_DISCOVERY_SESS:
3431                 len = sprintf(buf, "%u\n", session->discovery_sess);
3432                 break;
3433         case ISCSI_PARAM_PORTAL_TYPE:
3434                 len = sprintf(buf, "%s\n", session->portal_type);
3435                 break;
3436         case ISCSI_PARAM_CHAP_AUTH_EN:
3437                 len = sprintf(buf, "%u\n", session->chap_auth_en);
3438                 break;
3439         case ISCSI_PARAM_DISCOVERY_LOGOUT_EN:
3440                 len = sprintf(buf, "%u\n", session->discovery_logout_en);
3441                 break;
3442         case ISCSI_PARAM_BIDI_CHAP_EN:
3443                 len = sprintf(buf, "%u\n", session->bidi_chap_en);
3444                 break;
3445         case ISCSI_PARAM_DISCOVERY_AUTH_OPTIONAL:
3446                 len = sprintf(buf, "%u\n", session->discovery_auth_optional);
3447                 break;
3448         case ISCSI_PARAM_DEF_TIME2WAIT:
3449                 len = sprintf(buf, "%d\n", session->time2wait);
3450                 break;
3451         case ISCSI_PARAM_DEF_TIME2RETAIN:
3452                 len = sprintf(buf, "%d\n", session->time2retain);
3453                 break;
3454         case ISCSI_PARAM_TSID:
3455                 len = sprintf(buf, "%u\n", session->tsid);
3456                 break;
3457         case ISCSI_PARAM_ISID:
3458                 len = sprintf(buf, "%02x%02x%02x%02x%02x%02x\n",
3459                               session->isid[0], session->isid[1],
3460                               session->isid[2], session->isid[3],
3461                               session->isid[4], session->isid[5]);
3462                 break;
3463         case ISCSI_PARAM_DISCOVERY_PARENT_IDX:
3464                 len = sprintf(buf, "%u\n", session->discovery_parent_idx);
3465                 break;
3466         case ISCSI_PARAM_DISCOVERY_PARENT_TYPE:
3467                 if (session->discovery_parent_type)
3468                         len = sprintf(buf, "%s\n",
3469                                       session->discovery_parent_type);
3470                 else
3471                         len = sprintf(buf, "\n");
3472                 break;
3473         default:
3474                 return -ENOSYS;
3475         }
3476
3477         return len;
3478 }
3479 EXPORT_SYMBOL_GPL(iscsi_session_get_param);
3480
3481 int iscsi_conn_get_addr_param(struct sockaddr_storage *addr,
3482                               enum iscsi_param param, char *buf)
3483 {
3484         struct sockaddr_in6 *sin6 = NULL;
3485         struct sockaddr_in *sin = NULL;
3486         int len;
3487
3488         switch (addr->ss_family) {
3489         case AF_INET:
3490                 sin = (struct sockaddr_in *)addr;
3491                 break;
3492         case AF_INET6:
3493                 sin6 = (struct sockaddr_in6 *)addr;
3494                 break;
3495         default:
3496                 return -EINVAL;
3497         }
3498
3499         switch (param) {
3500         case ISCSI_PARAM_CONN_ADDRESS:
3501         case ISCSI_HOST_PARAM_IPADDRESS:
3502                 if (sin)
3503                         len = sprintf(buf, "%pI4\n", &sin->sin_addr.s_addr);
3504                 else
3505                         len = sprintf(buf, "%pI6\n", &sin6->sin6_addr);
3506                 break;
3507         case ISCSI_PARAM_CONN_PORT:
3508         case ISCSI_PARAM_LOCAL_PORT:
3509                 if (sin)
3510                         len = sprintf(buf, "%hu\n", be16_to_cpu(sin->sin_port));
3511                 else
3512                         len = sprintf(buf, "%hu\n",
3513                                       be16_to_cpu(sin6->sin6_port));
3514                 break;
3515         default:
3516                 return -EINVAL;
3517         }
3518
3519         return len;
3520 }
3521 EXPORT_SYMBOL_GPL(iscsi_conn_get_addr_param);
3522
3523 int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
3524                          enum iscsi_param param, char *buf)
3525 {
3526         struct iscsi_conn *conn = cls_conn->dd_data;
3527         int len;
3528
3529         switch(param) {
3530         case ISCSI_PARAM_PING_TMO:
3531                 len = sprintf(buf, "%u\n", conn->ping_timeout);
3532                 break;
3533         case ISCSI_PARAM_RECV_TMO:
3534                 len = sprintf(buf, "%u\n", conn->recv_timeout);
3535                 break;
3536         case ISCSI_PARAM_MAX_RECV_DLENGTH:
3537                 len = sprintf(buf, "%u\n", conn->max_recv_dlength);
3538                 break;
3539         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3540                 len = sprintf(buf, "%u\n", conn->max_xmit_dlength);
3541                 break;
3542         case ISCSI_PARAM_HDRDGST_EN:
3543                 len = sprintf(buf, "%d\n", conn->hdrdgst_en);
3544                 break;
3545         case ISCSI_PARAM_DATADGST_EN:
3546                 len = sprintf(buf, "%d\n", conn->datadgst_en);
3547                 break;
3548         case ISCSI_PARAM_IFMARKER_EN:
3549                 len = sprintf(buf, "%d\n", conn->ifmarker_en);
3550                 break;
3551         case ISCSI_PARAM_OFMARKER_EN:
3552                 len = sprintf(buf, "%d\n", conn->ofmarker_en);
3553                 break;
3554         case ISCSI_PARAM_EXP_STATSN:
3555                 len = sprintf(buf, "%u\n", conn->exp_statsn);
3556                 break;
3557         case ISCSI_PARAM_PERSISTENT_PORT:
3558                 len = sprintf(buf, "%d\n", conn->persistent_port);
3559                 break;
3560         case ISCSI_PARAM_PERSISTENT_ADDRESS:
3561                 len = sprintf(buf, "%s\n", conn->persistent_address);
3562                 break;
3563         case ISCSI_PARAM_STATSN:
3564                 len = sprintf(buf, "%u\n", conn->statsn);
3565                 break;
3566         case ISCSI_PARAM_MAX_SEGMENT_SIZE:
3567                 len = sprintf(buf, "%u\n", conn->max_segment_size);
3568                 break;
3569         case ISCSI_PARAM_KEEPALIVE_TMO:
3570                 len = sprintf(buf, "%u\n", conn->keepalive_tmo);
3571                 break;
3572         case ISCSI_PARAM_LOCAL_PORT:
3573                 len = sprintf(buf, "%u\n", conn->local_port);
3574                 break;
3575         case ISCSI_PARAM_TCP_TIMESTAMP_STAT:
3576                 len = sprintf(buf, "%u\n", conn->tcp_timestamp_stat);
3577                 break;
3578         case ISCSI_PARAM_TCP_NAGLE_DISABLE:
3579                 len = sprintf(buf, "%u\n", conn->tcp_nagle_disable);
3580                 break;
3581         case ISCSI_PARAM_TCP_WSF_DISABLE:
3582                 len = sprintf(buf, "%u\n", conn->tcp_wsf_disable);
3583                 break;
3584         case ISCSI_PARAM_TCP_TIMER_SCALE:
3585                 len = sprintf(buf, "%u\n", conn->tcp_timer_scale);
3586                 break;
3587         case ISCSI_PARAM_TCP_TIMESTAMP_EN:
3588                 len = sprintf(buf, "%u\n", conn->tcp_timestamp_en);
3589                 break;
3590         case ISCSI_PARAM_IP_FRAGMENT_DISABLE:
3591                 len = sprintf(buf, "%u\n", conn->fragment_disable);
3592                 break;
3593         case ISCSI_PARAM_IPV4_TOS:
3594                 len = sprintf(buf, "%u\n", conn->ipv4_tos);
3595                 break;
3596         case ISCSI_PARAM_IPV6_TC:
3597                 len = sprintf(buf, "%u\n", conn->ipv6_traffic_class);
3598                 break;
3599         case ISCSI_PARAM_IPV6_FLOW_LABEL:
3600                 len = sprintf(buf, "%u\n", conn->ipv6_flow_label);
3601                 break;
3602         case ISCSI_PARAM_IS_FW_ASSIGNED_IPV6:
3603                 len = sprintf(buf, "%u\n", conn->is_fw_assigned_ipv6);
3604                 break;
3605         case ISCSI_PARAM_TCP_XMIT_WSF:
3606                 len = sprintf(buf, "%u\n", conn->tcp_xmit_wsf);
3607                 break;
3608         case ISCSI_PARAM_TCP_RECV_WSF:
3609                 len = sprintf(buf, "%u\n", conn->tcp_recv_wsf);
3610                 break;
3611         case ISCSI_PARAM_LOCAL_IPADDR:
3612                 len = sprintf(buf, "%s\n", conn->local_ipaddr);
3613                 break;
3614         default:
3615                 return -ENOSYS;
3616         }
3617
3618         return len;
3619 }
3620 EXPORT_SYMBOL_GPL(iscsi_conn_get_param);
3621
3622 int iscsi_host_get_param(struct Scsi_Host *shost, enum iscsi_host_param param,
3623                          char *buf)
3624 {
3625         struct iscsi_host *ihost = shost_priv(shost);
3626         int len;
3627
3628         switch (param) {
3629         case ISCSI_HOST_PARAM_NETDEV_NAME:
3630                 len = sprintf(buf, "%s\n", ihost->netdev);
3631                 break;
3632         case ISCSI_HOST_PARAM_HWADDRESS:
3633                 len = sprintf(buf, "%s\n", ihost->hwaddress);
3634                 break;
3635         case ISCSI_HOST_PARAM_INITIATOR_NAME:
3636                 len = sprintf(buf, "%s\n", ihost->initiatorname);
3637                 break;
3638         default:
3639                 return -ENOSYS;
3640         }
3641
3642         return len;
3643 }
3644 EXPORT_SYMBOL_GPL(iscsi_host_get_param);
3645
3646 int iscsi_host_set_param(struct Scsi_Host *shost, enum iscsi_host_param param,
3647                          char *buf, int buflen)
3648 {
3649         struct iscsi_host *ihost = shost_priv(shost);
3650
3651         switch (param) {
3652         case ISCSI_HOST_PARAM_NETDEV_NAME:
3653                 return iscsi_switch_str_param(&ihost->netdev, buf);
3654         case ISCSI_HOST_PARAM_HWADDRESS:
3655                 return iscsi_switch_str_param(&ihost->hwaddress, buf);
3656         case ISCSI_HOST_PARAM_INITIATOR_NAME:
3657                 return iscsi_switch_str_param(&ihost->initiatorname, buf);
3658         default:
3659                 return -ENOSYS;
3660         }
3661
3662         return 0;
3663 }
3664 EXPORT_SYMBOL_GPL(iscsi_host_set_param);
3665
3666 MODULE_AUTHOR("Mike Christie");
3667 MODULE_DESCRIPTION("iSCSI library functions");
3668 MODULE_LICENSE("GPL");