drivers/scsi/libiscsi.c

   1 /*
   2  * iSCSI lib functions
   3  *
   4  * Copyright (C) 2006 Red Hat, Inc.  All rights reserved.
   5  * Copyright (C) 2004 - 2006 Mike Christie
   6  * Copyright (C) 2004 - 2005 Dmitry Yusupov
   7  * Copyright (C) 2004 - 2005 Alex Aizman
   8  * maintained by open-iscsi@googlegroups.com
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  23  */
  24 #include <linux/types.h>
  25 #include <linux/kfifo.h>
  26 #include <linux/delay.h>
  27 #include <linux/log2.h>
  28 #include <linux/slab.h>
  29 #include <linux/module.h>
  30 #include <asm/unaligned.h>
  31 #include <net/tcp.h>
  32 #include <scsi/scsi_cmnd.h>
  33 #include <scsi/scsi_device.h>
  34 #include <scsi/scsi_eh.h>
  35 #include <scsi/scsi_tcq.h>
  36 #include <scsi/scsi_host.h>
  37 #include <scsi/scsi.h>
  38 #include <scsi/iscsi_proto.h>
  39 #include <scsi/scsi_transport.h>
  40 #include <scsi/scsi_transport_iscsi.h>
  41 #include <scsi/libiscsi.h>
  42
  43 static int iscsi_dbg_lib_conn;
  44 module_param_named(debug_libiscsi_conn, iscsi_dbg_lib_conn, int,
  45                    S_IRUGO | S_IWUSR);
  46 MODULE_PARM_DESC(debug_libiscsi_conn,
  47                  "Turn on debugging for connections in libiscsi module. "
  48                  "Set to 1 to turn on, and zero to turn off. Default is off.");
  49
  50 static int iscsi_dbg_lib_session;
  51 module_param_named(debug_libiscsi_session, iscsi_dbg_lib_session, int,
  52                    S_IRUGO | S_IWUSR);
  53 MODULE_PARM_DESC(debug_libiscsi_session,
  54                  "Turn on debugging for sessions in libiscsi module. "
  55                  "Set to 1 to turn on, and zero to turn off. Default is off.");
  56
  57 static int iscsi_dbg_lib_eh;
  58 module_param_named(debug_libiscsi_eh, iscsi_dbg_lib_eh, int,
  59                    S_IRUGO | S_IWUSR);
  60 MODULE_PARM_DESC(debug_libiscsi_eh,
  61                  "Turn on debugging for error handling in libiscsi module. "
  62                  "Set to 1 to turn on, and zero to turn off. Default is off.");
  63
  64 #define ISCSI_DBG_CONN(_conn, dbg_fmt, arg...)                  \
  65         do {                                                    \
  66                 if (iscsi_dbg_lib_conn)                         \
  67                         iscsi_conn_printk(KERN_INFO, _conn,     \
  68                                              "%s " dbg_fmt,     \
  69                                              __func__, ##arg);  \
  70         } while (0);
  71
  72 #define ISCSI_DBG_SESSION(_session, dbg_fmt, arg...)                    \
  73         do {                                                            \
  74                 if (iscsi_dbg_lib_session)                              \
  75                         iscsi_session_printk(KERN_INFO, _session,       \
  76                                              "%s " dbg_fmt,             \
  77                                              __func__, ##arg);          \
  78         } while (0);
  79
  80 #define ISCSI_DBG_EH(_session, dbg_fmt, arg...)                         \
  81         do {                                                            \
  82                 if (iscsi_dbg_lib_eh)                                   \
  83                         iscsi_session_printk(KERN_INFO, _session,       \
  84                                              "%s " dbg_fmt,             \
  85                                              __func__, ##arg);          \
  86         } while (0);
  87
  88 inline void iscsi_conn_queue_work(struct iscsi_conn *conn)
  89 {
  90         struct Scsi_Host *shost = conn->session->host;
  91         struct iscsi_host *ihost = shost_priv(shost);
  92
  93         if (ihost->workq)
  94                 queue_work(ihost->workq, &conn->xmitwork);
  95 }
  96 EXPORT_SYMBOL_GPL(iscsi_conn_queue_work);
  97
  98 static void __iscsi_update_cmdsn(struct iscsi_session *session,
  99                                  uint32_t exp_cmdsn, uint32_t max_cmdsn)
 100 {
 101         /*
 102          * standard specifies this check for when to update expected and
 103          * max sequence numbers
 104          */
 105         if (iscsi_sna_lt(max_cmdsn, exp_cmdsn - 1))
 106                 return;
 107
 108         if (exp_cmdsn != session->exp_cmdsn &&
 109             !iscsi_sna_lt(exp_cmdsn, session->exp_cmdsn))
 110                 session->exp_cmdsn = exp_cmdsn;
 111
 112         if (max_cmdsn != session->max_cmdsn &&
 113             !iscsi_sna_lt(max_cmdsn, session->max_cmdsn))
 114                 session->max_cmdsn = max_cmdsn;
 115 }
 116
 117 void iscsi_update_cmdsn(struct iscsi_session *session, struct iscsi_nopin *hdr)
 118 {
 119         __iscsi_update_cmdsn(session, be32_to_cpu(hdr->exp_cmdsn),
 120                              be32_to_cpu(hdr->max_cmdsn));
 121 }
 122 EXPORT_SYMBOL_GPL(iscsi_update_cmdsn);
 123
 124 /**
 125  * iscsi_prep_data_out_pdu - initialize Data-Out
 126  * @task: scsi command task
 127  * @r2t: R2T info
 128  * @hdr: iscsi data in pdu
 129  *
 130  * Notes:
 131  *      Initialize Data-Out within this R2T sequence and finds
 132  *      proper data_offset within this SCSI command.
 133  *
 134  *      This function is called with connection lock taken.
 135  **/
 136 void iscsi_prep_data_out_pdu(struct iscsi_task *task, struct iscsi_r2t_info *r2t,
 137                            struct iscsi_data *hdr)
 138 {
 139         struct iscsi_conn *conn = task->conn;
 140         unsigned int left = r2t->data_length - r2t->sent;
 141
 142         task->hdr_len = sizeof(struct iscsi_data);
 143
 144         memset(hdr, 0, sizeof(struct iscsi_data));
 145         hdr->ttt = r2t->ttt;
 146         hdr->datasn = cpu_to_be32(r2t->datasn);
 147         r2t->datasn++;
 148         hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
 149         hdr->lun = task->lun;
 150         hdr->itt = task->hdr_itt;
 151         hdr->exp_statsn = r2t->exp_statsn;
 152         hdr->offset = cpu_to_be32(r2t->data_offset + r2t->sent);
 153         if (left > conn->max_xmit_dlength) {
 154                 hton24(hdr->dlength, conn->max_xmit_dlength);
 155                 r2t->data_count = conn->max_xmit_dlength;
 156                 hdr->flags = 0;
 157         } else {
 158                 hton24(hdr->dlength, left);
 159                 r2t->data_count = left;
 160                 hdr->flags = ISCSI_FLAG_CMD_FINAL;
 161         }
 162         conn->dataout_pdus_cnt++;
 163 }
 164 EXPORT_SYMBOL_GPL(iscsi_prep_data_out_pdu);
 165
 166 static int iscsi_add_hdr(struct iscsi_task *task, unsigned len)
 167 {
 168         unsigned exp_len = task->hdr_len + len;
 169
 170         if (exp_len > task->hdr_max) {
 171                 WARN_ON(1);
 172                 return -EINVAL;
 173         }
 174
 175         WARN_ON(len & (ISCSI_PAD_LEN - 1)); /* caller must pad the AHS */
 176         task->hdr_len = exp_len;
 177         return 0;
 178 }
 179
 180 /*
 181  * make an extended cdb AHS
 182  */
 183 static int iscsi_prep_ecdb_ahs(struct iscsi_task *task)
 184 {
 185         struct scsi_cmnd *cmd = task->sc;
 186         unsigned rlen, pad_len;
 187         unsigned short ahslength;
 188         struct iscsi_ecdb_ahdr *ecdb_ahdr;
 189         int rc;
 190
 191         ecdb_ahdr = iscsi_next_hdr(task);
 192         rlen = cmd->cmd_len - ISCSI_CDB_SIZE;
 193
 194         BUG_ON(rlen > sizeof(ecdb_ahdr->ecdb));
 195         ahslength = rlen + sizeof(ecdb_ahdr->reserved);
 196
 197         pad_len = iscsi_padding(rlen);
 198
 199         rc = iscsi_add_hdr(task, sizeof(ecdb_ahdr->ahslength) +
 200                            sizeof(ecdb_ahdr->ahstype) + ahslength + pad_len);
 201         if (rc)
 202                 return rc;
 203
 204         if (pad_len)
 205                 memset(&ecdb_ahdr->ecdb[rlen], 0, pad_len);
 206
 207         ecdb_ahdr->ahslength = cpu_to_be16(ahslength);
 208         ecdb_ahdr->ahstype = ISCSI_AHSTYPE_CDB;
 209         ecdb_ahdr->reserved = 0;
 210         memcpy(ecdb_ahdr->ecdb, cmd->cmnd + ISCSI_CDB_SIZE, rlen);
 211
 212         ISCSI_DBG_SESSION(task->conn->session,
 213                           "iscsi_prep_ecdb_ahs: varlen_cdb_len %d "
 214                           "rlen %d pad_len %d ahs_length %d iscsi_headers_size "
 215                           "%u\n", cmd->cmd_len, rlen, pad_len, ahslength,
 216                           task->hdr_len);
 217         return 0;
 218 }
 219
 220 static int iscsi_prep_bidi_ahs(struct iscsi_task *task)
 221 {
 222         struct scsi_cmnd *sc = task->sc;
 223         struct iscsi_rlength_ahdr *rlen_ahdr;
 224         int rc;
 225
 226         rlen_ahdr = iscsi_next_hdr(task);
 227         rc = iscsi_add_hdr(task, sizeof(*rlen_ahdr));
 228         if (rc)
 229                 return rc;
 230
 231         rlen_ahdr->ahslength =
 232                 cpu_to_be16(sizeof(rlen_ahdr->read_length) +
 233                                                   sizeof(rlen_ahdr->reserved));
 234         rlen_ahdr->ahstype = ISCSI_AHSTYPE_RLENGTH;
 235         rlen_ahdr->reserved = 0;
 236         rlen_ahdr->read_length = cpu_to_be32(scsi_in(sc)->length);
 237
 238         ISCSI_DBG_SESSION(task->conn->session,
 239                           "bidi-in rlen_ahdr->read_length(%d) "
 240                           "rlen_ahdr->ahslength(%d)\n",
 241                           be32_to_cpu(rlen_ahdr->read_length),
 242                           be16_to_cpu(rlen_ahdr->ahslength));
 243         return 0;
 244 }
 245
 246 /**
 247  * iscsi_check_tmf_restrictions - check if a task is affected by TMF
 248  * @task: iscsi task
 249  * @opcode: opcode to check for
 250  *
 251  * During TMF a task has to be checked if it's affected.
 252  * All unrelated I/O can be passed through, but I/O to the
 253  * affected LUN should be restricted.
 254  * If 'fast_abort' is set we won't be sending any I/O to the
 255  * affected LUN.
 256  * Otherwise the target is waiting for all TTTs to be completed,
 257  * so we have to send all outstanding Data-Out PDUs to the target.
 258  */
 259 static int iscsi_check_tmf_restrictions(struct iscsi_task *task, int opcode)
 260 {
 261         struct iscsi_conn *conn = task->conn;
 262         struct iscsi_tm *tmf = &conn->tmhdr;
 263         u64 hdr_lun;
 264
 265         if (conn->tmf_state == TMF_INITIAL)
 266                 return 0;
 267
 268         if ((tmf->opcode & ISCSI_OPCODE_MASK) != ISCSI_OP_SCSI_TMFUNC)
 269                 return 0;
 270
 271         switch (ISCSI_TM_FUNC_VALUE(tmf)) {
 272         case ISCSI_TM_FUNC_LOGICAL_UNIT_RESET:
 273                 /*
 274                  * Allow PDUs for unrelated LUNs
 275                  */
 276                 hdr_lun = scsilun_to_int(&tmf->lun);
 277                 if (hdr_lun != task->sc->device->lun)
 278                         return 0;
 279                 /* fall through */
 280         case ISCSI_TM_FUNC_TARGET_WARM_RESET:
 281                 /*
 282                  * Fail all SCSI cmd PDUs
 283                  */
 284                 if (opcode != ISCSI_OP_SCSI_DATA_OUT) {
 285                         iscsi_conn_printk(KERN_INFO, conn,
 286                                           "task [op %x/%x itt "
 287                                           "0x%x/0x%x] "
 288                                           "rejected.\n",
 289                                           task->hdr->opcode, opcode,
 290                                           task->itt, task->hdr_itt);
 291                         return -EACCES;
 292                 }
 293                 /*
 294                  * And also all data-out PDUs in response to R2T
 295                  * if fast_abort is set.
 296                  */
 297                 if (conn->session->fast_abort) {
 298                         iscsi_conn_printk(KERN_INFO, conn,
 299                                           "task [op %x/%x itt "
 300                                           "0x%x/0x%x] fast abort.\n",
 301                                           task->hdr->opcode, opcode,
 302                                           task->itt, task->hdr_itt);
 303                         return -EACCES;
 304                 }
 305                 break;
 306         case ISCSI_TM_FUNC_ABORT_TASK:
 307                 /*
 308                  * the caller has already checked if the task
 309                  * they want to abort was in the pending queue so if
 310                  * we are here the cmd pdu has gone out already, and
 311                  * we will only hit this for data-outs
 312                  */
 313                 if (opcode == ISCSI_OP_SCSI_DATA_OUT &&
 314                     task->hdr_itt == tmf->rtt) {
 315                         ISCSI_DBG_SESSION(conn->session,
 316                                           "Preventing task %x/%x from sending "
 317                                           "data-out due to abort task in "
 318                                           "progress\n", task->itt,
 319                                           task->hdr_itt);
 320                         return -EACCES;
 321                 }
 322                 break;
 323         }
 324
 325         return 0;
 326 }
 327
 328 /**
 329  * iscsi_prep_scsi_cmd_pdu - prep iscsi scsi cmd pdu
 330  * @task: iscsi task
 331  *
 332  * Prep basic iSCSI PDU fields for a scsi cmd pdu. The LLD should set
 333  * fields like dlength or final based on how much data it sends
 334  */
 335 static int iscsi_prep_scsi_cmd_pdu(struct iscsi_task *task)
 336 {
 337         struct iscsi_conn *conn = task->conn;
 338         struct iscsi_session *session = conn->session;
 339         struct scsi_cmnd *sc = task->sc;
 340         struct iscsi_scsi_req *hdr;
 341         unsigned hdrlength, cmd_len, transfer_length;
 342         itt_t itt;
 343         int rc;
 344
 345         rc = iscsi_check_tmf_restrictions(task, ISCSI_OP_SCSI_CMD);
 346         if (rc)
 347                 return rc;
 348
 349         if (conn->session->tt->alloc_pdu) {
 350                 rc = conn->session->tt->alloc_pdu(task, ISCSI_OP_SCSI_CMD);
 351                 if (rc)
 352                         return rc;
 353         }
 354         hdr = (struct iscsi_scsi_req *)task->hdr;
 355         itt = hdr->itt;
 356         memset(hdr, 0, sizeof(*hdr));
 357
 358         if (session->tt->parse_pdu_itt)
 359                 hdr->itt = task->hdr_itt = itt;
 360         else
 361                 hdr->itt = task->hdr_itt = build_itt(task->itt,
 362                                                      task->conn->session->age);
 363         task->hdr_len = 0;
 364         rc = iscsi_add_hdr(task, sizeof(*hdr));
 365         if (rc)
 366                 return rc;
 367         hdr->opcode = ISCSI_OP_SCSI_CMD;
 368         hdr->flags = ISCSI_ATTR_SIMPLE;
 369         int_to_scsilun(sc->device->lun, &hdr->lun);
 370         task->lun = hdr->lun;
 371         hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
 372         cmd_len = sc->cmd_len;
 373         if (cmd_len < ISCSI_CDB_SIZE)
 374                 memset(&hdr->cdb[cmd_len], 0, ISCSI_CDB_SIZE - cmd_len);
 375         else if (cmd_len > ISCSI_CDB_SIZE) {
 376                 rc = iscsi_prep_ecdb_ahs(task);
 377                 if (rc)
 378                         return rc;
 379                 cmd_len = ISCSI_CDB_SIZE;
 380         }
 381         memcpy(hdr->cdb, sc->cmnd, cmd_len);
 382
 383         task->imm_count = 0;
 384         if (scsi_bidi_cmnd(sc)) {
 385                 hdr->flags |= ISCSI_FLAG_CMD_READ;
 386                 rc = iscsi_prep_bidi_ahs(task);
 387                 if (rc)
 388                         return rc;
 389         }
 390
 391         if (scsi_get_prot_op(sc) != SCSI_PROT_NORMAL)
 392                 task->protected = true;
 393
 394         transfer_length = scsi_transfer_length(sc);
 395         hdr->data_length = cpu_to_be32(transfer_length);
 396         if (sc->sc_data_direction == DMA_TO_DEVICE) {
 397                 struct iscsi_r2t_info *r2t = &task->unsol_r2t;
 398
 399                 hdr->flags |= ISCSI_FLAG_CMD_WRITE;
 400                 /*
 401                  * Write counters:
 402                  *
 403                  *      imm_count       bytes to be sent right after
 404                  *                      SCSI PDU Header
 405                  *
 406                  *      unsol_count     bytes(as Data-Out) to be sent
 407                  *                      without R2T ack right after
 408                  *                      immediate data
 409                  *
 410                  *      r2t data_length bytes to be sent via R2T ack's
 411                  *
 412                  *      pad_count       bytes to be sent as zero-padding
 413                  */
 414                 memset(r2t, 0, sizeof(*r2t));
 415
 416                 if (session->imm_data_en) {
 417                         if (transfer_length >= session->first_burst)
 418                                 task->imm_count = min(session->first_burst,
 419                                                         conn->max_xmit_dlength);
 420                         else
 421                                 task->imm_count = min(transfer_length,
 422                                                       conn->max_xmit_dlength);
 423                         hton24(hdr->dlength, task->imm_count);
 424                 } else
 425                         zero_data(hdr->dlength);
 426
 427                 if (!session->initial_r2t_en) {
 428                         r2t->data_length = min(session->first_burst,
 429                                                transfer_length) -
 430                                                task->imm_count;
 431                         r2t->data_offset = task->imm_count;
 432                         r2t->ttt = cpu_to_be32(ISCSI_RESERVED_TAG);
 433                         r2t->exp_statsn = cpu_to_be32(conn->exp_statsn);
 434                 }
 435
 436                 if (!task->unsol_r2t.data_length)
 437                         /* No unsolicit Data-Out's */
 438                         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
 439         } else {
 440                 hdr->flags |= ISCSI_FLAG_CMD_FINAL;
 441                 zero_data(hdr->dlength);
 442
 443                 if (sc->sc_data_direction == DMA_FROM_DEVICE)
 444                         hdr->flags |= ISCSI_FLAG_CMD_READ;
 445         }
 446
 447         /* calculate size of additional header segments (AHSs) */
 448         hdrlength = task->hdr_len - sizeof(*hdr);
 449
 450         WARN_ON(hdrlength & (ISCSI_PAD_LEN-1));
 451         hdrlength /= ISCSI_PAD_LEN;
 452
 453         WARN_ON(hdrlength >= 256);
 454         hdr->hlength = hdrlength & 0xFF;
 455         hdr->cmdsn = task->cmdsn = cpu_to_be32(session->cmdsn);
 456
 457         if (session->tt->init_task && session->tt->init_task(task))
 458                 return -EIO;
 459
 460         task->state = ISCSI_TASK_RUNNING;
 461         session->cmdsn++;
 462
 463         conn->scsicmd_pdus_cnt++;
 464         ISCSI_DBG_SESSION(session, "iscsi prep [%s cid %d sc %p cdb 0x%x "
 465                           "itt 0x%x len %d bidi_len %d cmdsn %d win %d]\n",
 466                           scsi_bidi_cmnd(sc) ? "bidirectional" :
 467                           sc->sc_data_direction == DMA_TO_DEVICE ?
 468                           "write" : "read", conn->id, sc, sc->cmnd[0],
 469                           task->itt, transfer_length,
 470                           scsi_bidi_cmnd(sc) ? scsi_in(sc)->length : 0,
 471                           session->cmdsn,
 472                           session->max_cmdsn - session->exp_cmdsn + 1);
 473         return 0;
 474 }
 475
 476 /**
 477  * iscsi_free_task - free a task
 478  * @task: iscsi cmd task
 479  *
 480  * Must be called with session back_lock.
 481  * This function returns the scsi command to scsi-ml or cleans
 482  * up mgmt tasks then returns the task to the pool.
 483  */
 484 static void iscsi_free_task(struct iscsi_task *task)
 485 {
 486         struct iscsi_conn *conn = task->conn;
 487         struct iscsi_session *session = conn->session;
 488         struct scsi_cmnd *sc = task->sc;
 489         int oldstate = task->state;
 490
 491         ISCSI_DBG_SESSION(session, "freeing task itt 0x%x state %d sc %p\n",
 492                           task->itt, task->state, task->sc);
 493
 494         session->tt->cleanup_task(task);
 495         task->state = ISCSI_TASK_FREE;
 496         task->sc = NULL;
 497         /*
 498          * login task is preallocated so do not free
 499          */
 500         if (conn->login_task == task)
 501                 return;
 502
 503         kfifo_in(&session->cmdpool.queue, (void*)&task, sizeof(void*));
 504
 505         if (sc) {
 506                 /* SCSI eh reuses commands to verify us */
 507                 sc->SCp.ptr = NULL;
 508                 /*
 509                  * queue command may call this to free the task, so
 510                  * it will decide how to return sc to scsi-ml.
 511                  */
 512                 if (oldstate != ISCSI_TASK_REQUEUE_SCSIQ)
 513                         sc->scsi_done(sc);
 514         }
 515 }
 516
 517 void __iscsi_get_task(struct iscsi_task *task)
 518 {
 519         atomic_inc(&task->refcount);
 520 }
 521 EXPORT_SYMBOL_GPL(__iscsi_get_task);
 522
 523 void __iscsi_put_task(struct iscsi_task *task)
 524 {
 525         if (atomic_dec_and_test(&task->refcount))
 526                 iscsi_free_task(task);
 527 }
 528 EXPORT_SYMBOL_GPL(__iscsi_put_task);
 529
 530 void iscsi_put_task(struct iscsi_task *task)
 531 {
 532         struct iscsi_session *session = task->conn->session;
 533
 534         /* regular RX path uses back_lock */
 535         spin_lock_bh(&session->back_lock);
 536         __iscsi_put_task(task);
 537         spin_unlock_bh(&session->back_lock);
 538 }
 539 EXPORT_SYMBOL_GPL(iscsi_put_task);
 540
 541 /**
 542  * iscsi_complete_task - finish a task
 543  * @task: iscsi cmd task
 544  * @state: state to complete task with
 545  *
 546  * Must be called with session back_lock.
 547  */
 548 static void iscsi_complete_task(struct iscsi_task *task, int state)
 549 {
 550         struct iscsi_conn *conn = task->conn;
 551
 552         ISCSI_DBG_SESSION(conn->session,
 553                           "complete task itt 0x%x state %d sc %p\n",
 554                           task->itt, task->state, task->sc);
 555         if (task->state == ISCSI_TASK_COMPLETED ||
 556             task->state == ISCSI_TASK_ABRT_TMF ||
 557             task->state == ISCSI_TASK_ABRT_SESS_RECOV ||
 558             task->state == ISCSI_TASK_REQUEUE_SCSIQ)
 559                 return;
 560         WARN_ON_ONCE(task->state == ISCSI_TASK_FREE);
 561         task->state = state;
 562
 563         if (!list_empty(&task->running))
 564                 list_del_init(&task->running);
 565
 566         if (conn->task == task)
 567                 conn->task = NULL;
 568
 569         if (conn->ping_task == task)
 570                 conn->ping_task = NULL;
 571
 572         /* release get from queueing */
 573         __iscsi_put_task(task);
 574 }
 575
 576 /**
 577  * iscsi_complete_scsi_task - finish scsi task normally
 578  * @task: iscsi task for scsi cmd
 579  * @exp_cmdsn: expected cmd sn in cpu format
 580  * @max_cmdsn: max cmd sn in cpu format
 581  *
 582  * This is used when drivers do not need or cannot perform
 583  * lower level pdu processing.
 584  *
 585  * Called with session back_lock
 586  */
 587 void iscsi_complete_scsi_task(struct iscsi_task *task,
 588                               uint32_t exp_cmdsn, uint32_t max_cmdsn)
 589 {
 590         struct iscsi_conn *conn = task->conn;
 591
 592         ISCSI_DBG_SESSION(conn->session, "[itt 0x%x]\n", task->itt);
 593
 594         conn->last_recv = jiffies;
 595         __iscsi_update_cmdsn(conn->session, exp_cmdsn, max_cmdsn);
 596         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 597 }
 598 EXPORT_SYMBOL_GPL(iscsi_complete_scsi_task);
 599
 600
 601 /*
 602  * session back_lock must be held and if not called for a task that is
 603  * still pending or from the xmit thread, then xmit thread must
 604  * be suspended.
 605  */
 606 static void fail_scsi_task(struct iscsi_task *task, int err)
 607 {
 608         struct iscsi_conn *conn = task->conn;
 609         struct scsi_cmnd *sc;
 610         int state;
 611
 612         /*
 613          * if a command completes and we get a successful tmf response
 614          * we will hit this because the scsi eh abort code does not take
 615          * a ref to the task.
 616          */
 617         sc = task->sc;
 618         if (!sc)
 619                 return;
 620
 621         if (task->state == ISCSI_TASK_PENDING) {
 622                 /*
 623                  * cmd never made it to the xmit thread, so we should not count
 624                  * the cmd in the sequencing
 625                  */
 626                 conn->session->queued_cmdsn--;
 627                 /* it was never sent so just complete like normal */
 628                 state = ISCSI_TASK_COMPLETED;
 629         } else if (err == DID_TRANSPORT_DISRUPTED)
 630                 state = ISCSI_TASK_ABRT_SESS_RECOV;
 631         else
 632                 state = ISCSI_TASK_ABRT_TMF;
 633
 634         sc->result = err << 16;
 635         if (!scsi_bidi_cmnd(sc))
 636                 scsi_set_resid(sc, scsi_bufflen(sc));
 637         else {
 638                 scsi_out(sc)->resid = scsi_out(sc)->length;
 639                 scsi_in(sc)->resid = scsi_in(sc)->length;
 640         }
 641
 642         /* regular RX path uses back_lock */
 643         spin_lock_bh(&conn->session->back_lock);
 644         iscsi_complete_task(task, state);
 645         spin_unlock_bh(&conn->session->back_lock);
 646 }
 647
 648 static int iscsi_prep_mgmt_task(struct iscsi_conn *conn,
 649                                 struct iscsi_task *task)
 650 {
 651         struct iscsi_session *session = conn->session;
 652         struct iscsi_hdr *hdr = task->hdr;
 653         struct iscsi_nopout *nop = (struct iscsi_nopout *)hdr;
 654         uint8_t opcode = hdr->opcode & ISCSI_OPCODE_MASK;
 655
 656         if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
 657                 return -ENOTCONN;
 658
 659         if (opcode != ISCSI_OP_LOGIN && opcode != ISCSI_OP_TEXT)
 660                 nop->exp_statsn = cpu_to_be32(conn->exp_statsn);
 661         /*
 662          * pre-format CmdSN for outgoing PDU.
 663          */
 664         nop->cmdsn = cpu_to_be32(session->cmdsn);
 665         if (hdr->itt != RESERVED_ITT) {
 666                 /*
 667                  * TODO: We always use immediate for normal session pdus.
 668                  * If we start to send tmfs or nops as non-immediate then
 669                  * we should start checking the cmdsn numbers for mgmt tasks.
 670                  *
 671                  * During discovery sessions iscsid sends TEXT as non immediate,
 672                  * but we always only send one PDU at a time.
 673                  */
 674                 if (conn->c_stage == ISCSI_CONN_STARTED &&
 675                     !(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
 676                         session->queued_cmdsn++;
 677                         session->cmdsn++;
 678                 }
 679         }
 680
 681         if (session->tt->init_task && session->tt->init_task(task))
 682                 return -EIO;
 683
 684         if ((hdr->opcode & ISCSI_OPCODE_MASK) == ISCSI_OP_LOGOUT)
 685                 session->state = ISCSI_STATE_LOGGING_OUT;
 686
 687         task->state = ISCSI_TASK_RUNNING;
 688         ISCSI_DBG_SESSION(session, "mgmtpdu [op 0x%x hdr->itt 0x%x "
 689                           "datalen %d]\n", hdr->opcode & ISCSI_OPCODE_MASK,
 690                           hdr->itt, task->data_count);
 691         return 0;
 692 }
 693
 694 static struct iscsi_task *
 695 __iscsi_conn_send_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 696                       char *data, uint32_t data_size)
 697 {
 698         struct iscsi_session *session = conn->session;
 699         struct iscsi_host *ihost = shost_priv(session->host);
 700         uint8_t opcode = hdr->opcode & ISCSI_OPCODE_MASK;
 701         struct iscsi_task *task;
 702         itt_t itt;
 703
 704         if (session->state == ISCSI_STATE_TERMINATE)
 705                 return NULL;
 706
 707         if (opcode == ISCSI_OP_LOGIN || opcode == ISCSI_OP_TEXT) {
 708                 /*
 709                  * Login and Text are sent serially, in
 710                  * request-followed-by-response sequence.
 711                  * Same task can be used. Same ITT must be used.
 712                  * Note that login_task is preallocated at conn_create().
 713                  */
 714                 if (conn->login_task->state != ISCSI_TASK_FREE) {
 715                         iscsi_conn_printk(KERN_ERR, conn, "Login/Text in "
 716                                           "progress. Cannot start new task.\n");
 717                         return NULL;
 718                 }
 719
 720                 task = conn->login_task;
 721         } else {
 722                 if (session->state != ISCSI_STATE_LOGGED_IN)
 723                         return NULL;
 724
 725                 BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
 726                 BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);
 727
 728                 if (!kfifo_out(&session->cmdpool.queue,
 729                                  (void*)&task, sizeof(void*)))
 730                         return NULL;
 731         }
 732         /*
 733          * released in complete pdu for task we expect a response for, and
 734          * released by the lld when it has transmitted the task for
 735          * pdus we do not expect a response for.
 736          */
 737         atomic_set(&task->refcount, 1);
 738         task->conn = conn;
 739         task->sc = NULL;
 740         INIT_LIST_HEAD(&task->running);
 741         task->state = ISCSI_TASK_PENDING;
 742
 743         if (data_size) {
 744                 memcpy(task->data, data, data_size);
 745                 task->data_count = data_size;
 746         } else
 747                 task->data_count = 0;
 748
 749         if (conn->session->tt->alloc_pdu) {
 750                 if (conn->session->tt->alloc_pdu(task, hdr->opcode)) {
 751                         iscsi_conn_printk(KERN_ERR, conn, "Could not allocate "
 752                                          "pdu for mgmt task.\n");
 753                         goto free_task;
 754                 }
 755         }
 756
 757         itt = task->hdr->itt;
 758         task->hdr_len = sizeof(struct iscsi_hdr);
 759         memcpy(task->hdr, hdr, sizeof(struct iscsi_hdr));
 760
 761         if (hdr->itt != RESERVED_ITT) {
 762                 if (session->tt->parse_pdu_itt)
 763                         task->hdr->itt = itt;
 764                 else
 765                         task->hdr->itt = build_itt(task->itt,
 766                                                    task->conn->session->age);
 767         }
 768
 769         if (!ihost->workq) {
 770                 if (iscsi_prep_mgmt_task(conn, task))
 771                         goto free_task;
 772
 773                 if (session->tt->xmit_task(task))
 774                         goto free_task;
 775         } else {
 776                 list_add_tail(&task->running, &conn->mgmtqueue);
 777                 iscsi_conn_queue_work(conn);
 778         }
 779
 780         return task;
 781
 782 free_task:
 783         /* regular RX path uses back_lock */
 784         spin_lock_bh(&session->back_lock);
 785         __iscsi_put_task(task);
 786         spin_unlock_bh(&session->back_lock);
 787         return NULL;
 788 }
 789
 790 int iscsi_conn_send_pdu(struct iscsi_cls_conn *cls_conn, struct iscsi_hdr *hdr,
 791                         char *data, uint32_t data_size)
 792 {
 793         struct iscsi_conn *conn = cls_conn->dd_data;
 794         struct iscsi_session *session = conn->session;
 795         int err = 0;
 796
 797         spin_lock_bh(&session->frwd_lock);
 798         if (!__iscsi_conn_send_pdu(conn, hdr, data, data_size))
 799                 err = -EPERM;
 800         spin_unlock_bh(&session->frwd_lock);
 801         return err;
 802 }
 803 EXPORT_SYMBOL_GPL(iscsi_conn_send_pdu);
 804
 805 /**
 806  * iscsi_cmd_rsp - SCSI Command Response processing
 807  * @conn: iscsi connection
 808  * @hdr: iscsi header
 809  * @task: scsi command task
 810  * @data: cmd data buffer
 811  * @datalen: len of buffer
 812  *
 813  * iscsi_cmd_rsp sets up the scsi_cmnd fields based on the PDU and
 814  * then completes the command and task.
 815  **/
 816 static void iscsi_scsi_cmd_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 817                                struct iscsi_task *task, char *data,
 818                                int datalen)
 819 {
 820         struct iscsi_scsi_rsp *rhdr = (struct iscsi_scsi_rsp *)hdr;
 821         struct iscsi_session *session = conn->session;
 822         struct scsi_cmnd *sc = task->sc;
 823
 824         iscsi_update_cmdsn(session, (struct iscsi_nopin*)rhdr);
 825         conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 826
 827         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 828
 829         if (task->protected) {
 830                 sector_t sector;
 831                 u8 ascq;
 832
 833                 /**
 834                  * Transports that didn't implement check_protection
 835                  * callback but still published T10-PI support to scsi-mid
 836                  * deserve this BUG_ON.
 837                  **/
 838                 BUG_ON(!session->tt->check_protection);
 839
 840                 ascq = session->tt->check_protection(task, &sector);
 841                 if (ascq) {
 842                         sc->result = DRIVER_SENSE << 24 |
 843                                      SAM_STAT_CHECK_CONDITION;
 844                         scsi_build_sense_buffer(1, sc->sense_buffer,
 845                                                 ILLEGAL_REQUEST, 0x10, ascq);
 846                         sc->sense_buffer[7] = 0xc; /* Additional sense length */
 847                         sc->sense_buffer[8] = 0;   /* Information desc type */
 848                         sc->sense_buffer[9] = 0xa; /* Additional desc length */
 849                         sc->sense_buffer[10] = 0x80; /* Validity bit */
 850
 851                         put_unaligned_be64(sector, &sc->sense_buffer[12]);
 852                         goto out;
 853                 }
 854         }
 855
 856         if (rhdr->response != ISCSI_STATUS_CMD_COMPLETED) {
 857                 sc->result = DID_ERROR << 16;
 858                 goto out;
 859         }
 860
 861         if (rhdr->cmd_status == SAM_STAT_CHECK_CONDITION) {
 862                 uint16_t senselen;
 863
 864                 if (datalen < 2) {
 865 invalid_datalen:
 866                         iscsi_conn_printk(KERN_ERR,  conn,
 867                                          "Got CHECK_CONDITION but invalid data "
 868                                          "buffer size of %d\n", datalen);
 869                         sc->result = DID_BAD_TARGET << 16;
 870                         goto out;
 871                 }
 872
 873                 senselen = get_unaligned_be16(data);
 874                 if (datalen < senselen)
 875                         goto invalid_datalen;
 876
 877                 memcpy(sc->sense_buffer, data + 2,
 878                        min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
 879                 ISCSI_DBG_SESSION(session, "copied %d bytes of sense\n",
 880                                   min_t(uint16_t, senselen,
 881                                   SCSI_SENSE_BUFFERSIZE));
 882         }
 883
 884         if (rhdr->flags & (ISCSI_FLAG_CMD_BIDI_UNDERFLOW |
 885                            ISCSI_FLAG_CMD_BIDI_OVERFLOW)) {
 886                 int res_count = be32_to_cpu(rhdr->bi_residual_count);
 887
 888                 if (scsi_bidi_cmnd(sc) && res_count > 0 &&
 889                                 (rhdr->flags & ISCSI_FLAG_CMD_BIDI_OVERFLOW ||
 890                                  res_count <= scsi_in(sc)->length))
 891                         scsi_in(sc)->resid = res_count;
 892                 else
 893                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 894         }
 895
 896         if (rhdr->flags & (ISCSI_FLAG_CMD_UNDERFLOW |
 897                            ISCSI_FLAG_CMD_OVERFLOW)) {
 898                 int res_count = be32_to_cpu(rhdr->residual_count);
 899
 900                 if (res_count > 0 &&
 901                     (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
 902                      res_count <= scsi_bufflen(sc)))
 903                         /* write side for bidi or uni-io set_resid */
 904                         scsi_set_resid(sc, res_count);
 905                 else
 906                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 907         }
 908 out:
 909         ISCSI_DBG_SESSION(session, "cmd rsp done [sc %p res %d itt 0x%x]\n",
 910                           sc, sc->result, task->itt);
 911         conn->scsirsp_pdus_cnt++;
 912         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 913 }
 914
 915 /**
 916  * iscsi_data_in_rsp - SCSI Data-In Response processing
 917  * @conn: iscsi connection
 918  * @hdr:  iscsi pdu
 919  * @task: scsi command task
 920  **/
 921 static void
 922 iscsi_data_in_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 923                   struct iscsi_task *task)
 924 {
 925         struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)hdr;
 926         struct scsi_cmnd *sc = task->sc;
 927
 928         if (!(rhdr->flags & ISCSI_FLAG_DATA_STATUS))
 929                 return;
 930
 931         iscsi_update_cmdsn(conn->session, (struct iscsi_nopin *)hdr);
 932         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 933         conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 934         if (rhdr->flags & (ISCSI_FLAG_DATA_UNDERFLOW |
 935                            ISCSI_FLAG_DATA_OVERFLOW)) {
 936                 int res_count = be32_to_cpu(rhdr->residual_count);
 937
 938                 if (res_count > 0 &&
 939                     (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
 940                      res_count <= scsi_in(sc)->length))
 941                         scsi_in(sc)->resid = res_count;
 942                 else
 943                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 944         }
 945
 946         ISCSI_DBG_SESSION(conn->session, "data in with status done "
 947                           "[sc %p res %d itt 0x%x]\n",
 948                           sc, sc->result, task->itt);
 949         conn->scsirsp_pdus_cnt++;
 950         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 951 }
 952
 953 static void iscsi_tmf_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
 954 {
 955         struct iscsi_tm_rsp *tmf = (struct iscsi_tm_rsp *)hdr;
 956
 957         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 958         conn->tmfrsp_pdus_cnt++;
 959
 960         if (conn->tmf_state != TMF_QUEUED)
 961                 return;
 962
 963         if (tmf->response == ISCSI_TMF_RSP_COMPLETE)
 964                 conn->tmf_state = TMF_SUCCESS;
 965         else if (tmf->response == ISCSI_TMF_RSP_NO_TASK)
 966                 conn->tmf_state = TMF_NOT_FOUND;
 967         else
 968                 conn->tmf_state = TMF_FAILED;
 969         wake_up(&conn->ehwait);
 970 }
 971
 972 static void iscsi_send_nopout(struct iscsi_conn *conn, struct iscsi_nopin *rhdr)
 973 {
 974         struct iscsi_nopout hdr;
 975         struct iscsi_task *task;
 976
 977         if (!rhdr && conn->ping_task)
 978                 return;
 979
 980         memset(&hdr, 0, sizeof(struct iscsi_nopout));
 981         hdr.opcode = ISCSI_OP_NOOP_OUT | ISCSI_OP_IMMEDIATE;
 982         hdr.flags = ISCSI_FLAG_CMD_FINAL;
 983
 984         if (rhdr) {
 985                 hdr.lun = rhdr->lun;
 986                 hdr.ttt = rhdr->ttt;
 987                 hdr.itt = RESERVED_ITT;
 988         } else
 989                 hdr.ttt = RESERVED_ITT;
 990
 991         task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)&hdr, NULL, 0);
 992         if (!task)
 993                 iscsi_conn_printk(KERN_ERR, conn, "Could not send nopout\n");
 994         else if (!rhdr) {
 995                 /* only track our nops */
 996                 conn->ping_task = task;
 997                 conn->last_ping = jiffies;
 998         }
 999 }
1000
1001 static int iscsi_nop_out_rsp(struct iscsi_task *task,
1002                              struct iscsi_nopin *nop, char *data, int datalen)
1003 {
1004         struct iscsi_conn *conn = task->conn;
1005         int rc = 0;
1006
1007         if (conn->ping_task != task) {
1008                 /*
1009                  * If this is not in response to one of our
1010                  * nops then it must be from userspace.
1011                  */
1012                 if (iscsi_recv_pdu(conn->cls_conn, (struct iscsi_hdr *)nop,
1013                                    data, datalen))
1014                         rc = ISCSI_ERR_CONN_FAILED;
1015         } else
1016                 mod_timer(&conn->transport_timer, jiffies + conn->recv_timeout);
1017         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1018         return rc;
1019 }
1020
1021 static int iscsi_handle_reject(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1022                                char *data, int datalen)
1023 {
1024         struct iscsi_reject *reject = (struct iscsi_reject *)hdr;
1025         struct iscsi_hdr rejected_pdu;
1026         int opcode, rc = 0;
1027
1028         conn->exp_statsn = be32_to_cpu(reject->statsn) + 1;
1029
1030         if (ntoh24(reject->dlength) > datalen ||
1031             ntoh24(reject->dlength) < sizeof(struct iscsi_hdr)) {
1032                 iscsi_conn_printk(KERN_ERR, conn, "Cannot handle rejected "
1033                                   "pdu. Invalid data length (pdu dlength "
1034                                   "%u, datalen %d\n", ntoh24(reject->dlength),
1035                                   datalen);
1036                 return ISCSI_ERR_PROTO;
1037         }
1038         memcpy(&rejected_pdu, data, sizeof(struct iscsi_hdr));
1039         opcode = rejected_pdu.opcode & ISCSI_OPCODE_MASK;
1040
1041         switch (reject->reason) {
1042         case ISCSI_REASON_DATA_DIGEST_ERROR:
1043                 iscsi_conn_printk(KERN_ERR, conn,
1044                                   "pdu (op 0x%x itt 0x%x) rejected "
1045                                   "due to DataDigest error.\n",
1046                                   opcode, rejected_pdu.itt);
1047                 break;
1048         case ISCSI_REASON_IMM_CMD_REJECT:
1049                 iscsi_conn_printk(KERN_ERR, conn,
1050                                   "pdu (op 0x%x itt 0x%x) rejected. Too many "
1051                                   "immediate commands.\n",
1052                                   opcode, rejected_pdu.itt);
1053                 /*
1054                  * We only send one TMF at a time so if the target could not
1055                  * handle it, then it should get fixed (RFC mandates that
1056                  * a target can handle one immediate TMF per conn).
1057                  *
1058                  * For nops-outs, we could have sent more than one if
1059                  * the target is sending us lots of nop-ins
1060                  */
1061                 if (opcode != ISCSI_OP_NOOP_OUT)
1062                         return 0;
1063
1064                  if (rejected_pdu.itt == cpu_to_be32(ISCSI_RESERVED_TAG)) {
1065                         /*
1066                          * nop-out in response to target's nop-out rejected.
1067                          * Just resend.
1068                          */
1069                         /* In RX path we are under back lock */
1070                         spin_unlock(&conn->session->back_lock);
1071                         spin_lock(&conn->session->frwd_lock);
1072                         iscsi_send_nopout(conn,
1073                                           (struct iscsi_nopin*)&rejected_pdu);
1074                         spin_unlock(&conn->session->frwd_lock);
1075                         spin_lock(&conn->session->back_lock);
1076                 } else {
1077                         struct iscsi_task *task;
1078                         /*
1079                          * Our nop as ping got dropped. We know the target
1080                          * and transport are ok so just clean up
1081                          */
1082                         task = iscsi_itt_to_task(conn, rejected_pdu.itt);
1083                         if (!task) {
1084                                 iscsi_conn_printk(KERN_ERR, conn,
1085                                                  "Invalid pdu reject. Could "
1086                                                  "not lookup rejected task.\n");
1087                                 rc = ISCSI_ERR_BAD_ITT;
1088                         } else
1089                                 rc = iscsi_nop_out_rsp(task,
1090                                         (struct iscsi_nopin*)&rejected_pdu,
1091                                         NULL, 0);
1092                 }
1093                 break;
1094         default:
1095                 iscsi_conn_printk(KERN_ERR, conn,
1096                                   "pdu (op 0x%x itt 0x%x) rejected. Reason "
1097                                   "code 0x%x\n", rejected_pdu.opcode,
1098                                   rejected_pdu.itt, reject->reason);
1099                 break;
1100         }
1101         return rc;
1102 }
1103
1104 /**
1105  * iscsi_itt_to_task - look up task by itt
1106  * @conn: iscsi connection
1107  * @itt: itt
1108  *
1109  * This should be used for mgmt tasks like login and nops, or if
1110  * the LDD's itt space does not include the session age.
1111  *
1112  * The session back_lock must be held.
1113  */
1114 struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *conn, itt_t itt)
1115 {
1116         struct iscsi_session *session = conn->session;
1117         int i;
1118
1119         if (itt == RESERVED_ITT)
1120                 return NULL;
1121
1122         if (session->tt->parse_pdu_itt)
1123                 session->tt->parse_pdu_itt(conn, itt, &i, NULL);
1124         else
1125                 i = get_itt(itt);
1126         if (i >= session->cmds_max)
1127                 return NULL;
1128
1129         return session->cmds[i];
1130 }
1131 EXPORT_SYMBOL_GPL(iscsi_itt_to_task);
1132
1133 /**
1134  * __iscsi_complete_pdu - complete pdu
1135  * @conn: iscsi conn
1136  * @hdr: iscsi header
1137  * @data: data buffer
1138  * @datalen: len of data buffer
1139  *
1140  * Completes pdu processing by freeing any resources allocated at
1141  * queuecommand or send generic. session back_lock must be held and verify
1142  * itt must have been called.
1143  */
1144 int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1145                          char *data, int datalen)
1146 {
1147         struct iscsi_session *session = conn->session;
1148         int opcode = hdr->opcode & ISCSI_OPCODE_MASK, rc = 0;
1149         struct iscsi_task *task;
1150         uint32_t itt;
1151
1152         conn->last_recv = jiffies;
1153         rc = iscsi_verify_itt(conn, hdr->itt);
1154         if (rc)
1155                 return rc;
1156
1157         if (hdr->itt != RESERVED_ITT)
1158                 itt = get_itt(hdr->itt);
1159         else
1160                 itt = ~0U;
1161
1162         ISCSI_DBG_SESSION(session, "[op 0x%x cid %d itt 0x%x len %d]\n",
1163                           opcode, conn->id, itt, datalen);
1164
1165         if (itt == ~0U) {
1166                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1167
1168                 switch(opcode) {
1169                 case ISCSI_OP_NOOP_IN:
1170                         if (datalen) {
1171                                 rc = ISCSI_ERR_PROTO;
1172                                 break;
1173                         }
1174
1175                         if (hdr->ttt == cpu_to_be32(ISCSI_RESERVED_TAG))
1176                                 break;
1177
1178                         /* In RX path we are under back lock */
1179                         spin_unlock(&session->back_lock);
1180                         spin_lock(&session->frwd_lock);
1181                         iscsi_send_nopout(conn, (struct iscsi_nopin*)hdr);
1182                         spin_unlock(&session->frwd_lock);
1183                         spin_lock(&session->back_lock);
1184                         break;
1185                 case ISCSI_OP_REJECT:
1186                         rc = iscsi_handle_reject(conn, hdr, data, datalen);
1187                         break;
1188                 case ISCSI_OP_ASYNC_EVENT:
1189                         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1190                         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
1191                                 rc = ISCSI_ERR_CONN_FAILED;
1192                         break;
1193                 default:
1194                         rc = ISCSI_ERR_BAD_OPCODE;
1195                         break;
1196                 }
1197                 goto out;
1198         }
1199
1200         switch(opcode) {
1201         case ISCSI_OP_SCSI_CMD_RSP:
1202         case ISCSI_OP_SCSI_DATA_IN:
1203                 task = iscsi_itt_to_ctask(conn, hdr->itt);
1204                 if (!task)
1205                         return ISCSI_ERR_BAD_ITT;
1206                 task->last_xfer = jiffies;
1207                 break;
1208         case ISCSI_OP_R2T:
1209                 /*
1210                  * LLD handles R2Ts if they need to.
1211                  */
1212                 return 0;
1213         case ISCSI_OP_LOGOUT_RSP:
1214         case ISCSI_OP_LOGIN_RSP:
1215         case ISCSI_OP_TEXT_RSP:
1216         case ISCSI_OP_SCSI_TMFUNC_RSP:
1217         case ISCSI_OP_NOOP_IN:
1218                 task = iscsi_itt_to_task(conn, hdr->itt);
1219                 if (!task)
1220                         return ISCSI_ERR_BAD_ITT;
1221                 break;
1222         default:
1223                 return ISCSI_ERR_BAD_OPCODE;
1224         }
1225
1226         switch(opcode) {
1227         case ISCSI_OP_SCSI_CMD_RSP:
1228                 iscsi_scsi_cmd_rsp(conn, hdr, task, data, datalen);
1229                 break;
1230         case ISCSI_OP_SCSI_DATA_IN:
1231                 iscsi_data_in_rsp(conn, hdr, task);
1232                 break;
1233         case ISCSI_OP_LOGOUT_RSP:
1234                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1235                 if (datalen) {
1236                         rc = ISCSI_ERR_PROTO;
1237                         break;
1238                 }
1239                 conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1240                 goto recv_pdu;
1241         case ISCSI_OP_LOGIN_RSP:
1242         case ISCSI_OP_TEXT_RSP:
1243                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1244                 /*
1245                  * login related PDU's exp_statsn is handled in
1246                  * userspace
1247                  */
1248                 goto recv_pdu;
1249         case ISCSI_OP_SCSI_TMFUNC_RSP:
1250                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1251                 if (datalen) {
1252                         rc = ISCSI_ERR_PROTO;
1253                         break;
1254                 }
1255
1256                 iscsi_tmf_rsp(conn, hdr);
1257                 iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1258                 break;
1259         case ISCSI_OP_NOOP_IN:
1260                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1261                 if (hdr->ttt != cpu_to_be32(ISCSI_RESERVED_TAG) || datalen) {
1262                         rc = ISCSI_ERR_PROTO;
1263                         break;
1264                 }
1265                 conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1266
1267                 rc = iscsi_nop_out_rsp(task, (struct iscsi_nopin*)hdr,
1268                                        data, datalen);
1269                 break;
1270         default:
1271                 rc = ISCSI_ERR_BAD_OPCODE;
1272                 break;
1273         }
1274
1275 out:
1276         return rc;
1277 recv_pdu:
1278         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
1279                 rc = ISCSI_ERR_CONN_FAILED;
1280         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1281         return rc;
1282 }
1283 EXPORT_SYMBOL_GPL(__iscsi_complete_pdu);
1284
1285 int iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1286                        char *data, int datalen)
1287 {
1288         int rc;
1289
1290         spin_lock(&conn->session->back_lock);
1291         rc = __iscsi_complete_pdu(conn, hdr, data, datalen);
1292         spin_unlock(&conn->session->back_lock);
1293         return rc;
1294 }
1295 EXPORT_SYMBOL_GPL(iscsi_complete_pdu);
1296
1297 int iscsi_verify_itt(struct iscsi_conn *conn, itt_t itt)
1298 {
1299         struct iscsi_session *session = conn->session;
1300         int age = 0, i = 0;
1301
1302         if (itt == RESERVED_ITT)
1303                 return 0;
1304
1305         if (session->tt->parse_pdu_itt)
1306                 session->tt->parse_pdu_itt(conn, itt, &i, &age);
1307         else {
1308                 i = get_itt(itt);
1309                 age = ((__force u32)itt >> ISCSI_AGE_SHIFT) & ISCSI_AGE_MASK;
1310         }
1311
1312         if (age != session->age) {
1313                 iscsi_conn_printk(KERN_ERR, conn,
1314                                   "received itt %x expected session age (%x)\n",
1315                                   (__force u32)itt, session->age);
1316                 return ISCSI_ERR_BAD_ITT;
1317         }
1318
1319         if (i >= session->cmds_max) {
1320                 iscsi_conn_printk(KERN_ERR, conn,
1321                                   "received invalid itt index %u (max cmds "
1322                                    "%u.\n", i, session->cmds_max);
1323                 return ISCSI_ERR_BAD_ITT;
1324         }
1325         return 0;
1326 }
1327 EXPORT_SYMBOL_GPL(iscsi_verify_itt);
1328
1329 /**
1330  * iscsi_itt_to_ctask - look up ctask by itt
1331  * @conn: iscsi connection
1332  * @itt: itt
1333  *
1334  * This should be used for cmd tasks.
1335  *
1336  * The session back_lock must be held.
1337  */
1338 struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *conn, itt_t itt)
1339 {
1340         struct iscsi_task *task;
1341
1342         if (iscsi_verify_itt(conn, itt))
1343                 return NULL;
1344
1345         task = iscsi_itt_to_task(conn, itt);
1346         if (!task || !task->sc)
1347                 return NULL;
1348
1349         if (task->sc->SCp.phase != conn->session->age) {
1350                 iscsi_session_printk(KERN_ERR, conn->session,
1351                                   "task's session age %d, expected %d\n",
1352                                   task->sc->SCp.phase, conn->session->age);
1353                 return NULL;
1354         }
1355
1356         return task;
1357 }
1358 EXPORT_SYMBOL_GPL(iscsi_itt_to_ctask);
1359
1360 void iscsi_session_failure(struct iscsi_session *session,
1361                            enum iscsi_err err)
1362 {
1363         struct iscsi_conn *conn;
1364         struct device *dev;
1365
1366         spin_lock_bh(&session->frwd_lock);
1367         conn = session->leadconn;
1368         if (session->state == ISCSI_STATE_TERMINATE || !conn) {
1369                 spin_unlock_bh(&session->frwd_lock);
1370                 return;
1371         }
1372
1373         dev = get_device(&conn->cls_conn->dev);
1374         spin_unlock_bh(&session->frwd_lock);
1375         if (!dev)
1376                 return;
1377         /*
1378          * if the host is being removed bypass the connection
1379          * recovery initialization because we are going to kill
1380          * the session.
1381          */
1382         if (err == ISCSI_ERR_INVALID_HOST)
1383                 iscsi_conn_error_event(conn->cls_conn, err);
1384         else
1385                 iscsi_conn_failure(conn, err);
1386         put_device(dev);
1387 }
1388 EXPORT_SYMBOL_GPL(iscsi_session_failure);
1389
1390 void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err)
1391 {
1392         struct iscsi_session *session = conn->session;
1393
1394         spin_lock_bh(&session->frwd_lock);
1395         if (session->state == ISCSI_STATE_FAILED) {
1396                 spin_unlock_bh(&session->frwd_lock);
1397                 return;
1398         }
1399
1400         if (conn->stop_stage == 0)
1401                 session->state = ISCSI_STATE_FAILED;
1402         spin_unlock_bh(&session->frwd_lock);
1403
1404         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1405         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
1406         iscsi_conn_error_event(conn->cls_conn, err);
1407 }
1408 EXPORT_SYMBOL_GPL(iscsi_conn_failure);
1409
1410 static int iscsi_check_cmdsn_window_closed(struct iscsi_conn *conn)
1411 {
1412         struct iscsi_session *session = conn->session;
1413
1414         /*
1415          * Check for iSCSI window and take care of CmdSN wrap-around
1416          */
1417         if (!iscsi_sna_lte(session->queued_cmdsn, session->max_cmdsn)) {
1418                 ISCSI_DBG_SESSION(session, "iSCSI CmdSN closed. ExpCmdSn "
1419                                   "%u MaxCmdSN %u CmdSN %u/%u\n",
1420                                   session->exp_cmdsn, session->max_cmdsn,
1421                                   session->cmdsn, session->queued_cmdsn);
1422                 return -ENOSPC;
1423         }
1424         return 0;
1425 }
1426
1427 static int iscsi_xmit_task(struct iscsi_conn *conn)
1428 {
1429         struct iscsi_task *task = conn->task;
1430         int rc;
1431
1432         if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx))
1433                 return -ENODATA;
1434
1435         __iscsi_get_task(task);
1436         spin_unlock_bh(&conn->session->frwd_lock);
1437         rc = conn->session->tt->xmit_task(task);
1438         spin_lock_bh(&conn->session->frwd_lock);
1439         if (!rc) {
1440                 /* done with this task */
1441                 task->last_xfer = jiffies;
1442                 conn->task = NULL;
1443         }
1444         /* regular RX path uses back_lock */
1445         spin_lock(&conn->session->back_lock);
1446         __iscsi_put_task(task);
1447         spin_unlock(&conn->session->back_lock);
1448         return rc;
1449 }
1450
1451 /**
1452  * iscsi_requeue_task - requeue task to run from session workqueue
1453  * @task: task to requeue
1454  *
1455  * LLDs that need to run a task from the session workqueue should call
1456  * this. The session frwd_lock must be held. This should only be called
1457  * by software drivers.
1458  */
1459 void iscsi_requeue_task(struct iscsi_task *task)
1460 {
1461         struct iscsi_conn *conn = task->conn;
1462
1463         /*
1464          * this may be on the requeue list already if the xmit_task callout
1465          * is handling the r2ts while we are adding new ones
1466          */
1467         if (list_empty(&task->running))
1468                 list_add_tail(&task->running, &conn->requeue);
1469         iscsi_conn_queue_work(conn);
1470 }
1471 EXPORT_SYMBOL_GPL(iscsi_requeue_task);
1472
1473 /**
1474  * iscsi_data_xmit - xmit any command into the scheduled connection
1475  * @conn: iscsi connection
1476  *
1477  * Notes:
1478  *      The function can return -EAGAIN in which case the caller must
1479  *      re-schedule it again later or recover. '0' return code means
1480  *      successful xmit.
1481  **/
1482 static int iscsi_data_xmit(struct iscsi_conn *conn)
1483 {
1484         struct iscsi_task *task;
1485         int rc = 0;
1486
1487         spin_lock_bh(&conn->session->frwd_lock);
1488         if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx)) {
1489                 ISCSI_DBG_SESSION(conn->session, "Tx suspended!\n");
1490                 spin_unlock_bh(&conn->session->frwd_lock);
1491                 return -ENODATA;
1492         }
1493
1494         if (conn->task) {
1495                 rc = iscsi_xmit_task(conn);
1496                 if (rc)
1497                         goto done;
1498         }
1499
1500         /*
1501          * process mgmt pdus like nops before commands since we should
1502          * only have one nop-out as a ping from us and targets should not
1503          * overflow us with nop-ins
1504          */
1505 check_mgmt:
1506         while (!list_empty(&conn->mgmtqueue)) {
1507                 conn->task = list_entry(conn->mgmtqueue.next,
1508                                          struct iscsi_task, running);
1509                 list_del_init(&conn->task->running);
1510                 if (iscsi_prep_mgmt_task(conn, conn->task)) {
1511                         /* regular RX path uses back_lock */
1512                         spin_lock_bh(&conn->session->back_lock);
1513                         __iscsi_put_task(conn->task);
1514                         spin_unlock_bh(&conn->session->back_lock);
1515                         conn->task = NULL;
1516                         continue;
1517                 }
1518                 rc = iscsi_xmit_task(conn);
1519                 if (rc)
1520                         goto done;
1521         }
1522
1523         /* process pending command queue */
1524         while (!list_empty(&conn->cmdqueue)) {
1525                 conn->task = list_entry(conn->cmdqueue.next, struct iscsi_task,
1526                                         running);
1527                 list_del_init(&conn->task->running);
1528                 if (conn->session->state == ISCSI_STATE_LOGGING_OUT) {
1529                         fail_scsi_task(conn->task, DID_IMM_RETRY);
1530                         continue;
1531                 }
1532                 rc = iscsi_prep_scsi_cmd_pdu(conn->task);
1533                 if (rc) {
1534                         if (rc == -ENOMEM || rc == -EACCES) {
1535                                 list_add_tail(&conn->task->running,
1536                                               &conn->cmdqueue);
1537                                 conn->task = NULL;
1538                                 goto done;
1539                         } else
1540                                 fail_scsi_task(conn->task, DID_ABORT);
1541                         continue;
1542                 }
1543                 rc = iscsi_xmit_task(conn);
1544                 if (rc)
1545                         goto done;
1546                 /*
1547                  * we could continuously get new task requests so
1548                  * we need to check the mgmt queue for nops that need to
1549                  * be sent to aviod starvation
1550                  */
1551                 if (!list_empty(&conn->mgmtqueue))
1552                         goto check_mgmt;
1553         }
1554
1555         while (!list_empty(&conn->requeue)) {
1556                 /*
1557                  * we always do fastlogout - conn stop code will clean up.
1558                  */
1559                 if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
1560                         break;
1561
1562                 task = list_entry(conn->requeue.next, struct iscsi_task,
1563                                   running);
1564                 if (iscsi_check_tmf_restrictions(task, ISCSI_OP_SCSI_DATA_OUT))
1565                         break;
1566
1567                 conn->task = task;
1568                 list_del_init(&conn->task->running);
1569                 conn->task->state = ISCSI_TASK_RUNNING;
1570                 rc = iscsi_xmit_task(conn);
1571                 if (rc)
1572                         goto done;
1573                 if (!list_empty(&conn->mgmtqueue))
1574                         goto check_mgmt;
1575         }
1576         spin_unlock_bh(&conn->session->frwd_lock);
1577         return -ENODATA;
1578
1579 done:
1580         spin_unlock_bh(&conn->session->frwd_lock);
1581         return rc;
1582 }
1583
1584 static void iscsi_xmitworker(struct work_struct *work)
1585 {
1586         struct iscsi_conn *conn =
1587                 container_of(work, struct iscsi_conn, xmitwork);
1588         int rc;
1589         /*
1590          * serialize Xmit worker on a per-connection basis.
1591          */
1592         do {
1593                 rc = iscsi_data_xmit(conn);
1594         } while (rc >= 0 || rc == -EAGAIN);
1595 }
1596
1597 static inline struct iscsi_task *iscsi_alloc_task(struct iscsi_conn *conn,
1598                                                   struct scsi_cmnd *sc)
1599 {
1600         struct iscsi_task *task;
1601
1602         if (!kfifo_out(&conn->session->cmdpool.queue,
1603                          (void *) &task, sizeof(void *)))
1604                 return NULL;
1605
1606         sc->SCp.phase = conn->session->age;
1607         sc->SCp.ptr = (char *) task;
1608
1609         atomic_set(&task->refcount, 1);
1610         task->state = ISCSI_TASK_PENDING;
1611         task->conn = conn;
1612         task->sc = sc;
1613         task->have_checked_conn = false;
1614         task->last_timeout = jiffies;
1615         task->last_xfer = jiffies;
1616         task->protected = false;
1617         INIT_LIST_HEAD(&task->running);
1618         return task;
1619 }
1620
1621 enum {
1622         FAILURE_BAD_HOST = 1,
1623         FAILURE_SESSION_FAILED,
1624         FAILURE_SESSION_FREED,
1625         FAILURE_WINDOW_CLOSED,
1626         FAILURE_OOM,
1627         FAILURE_SESSION_TERMINATE,
1628         FAILURE_SESSION_IN_RECOVERY,
1629         FAILURE_SESSION_RECOVERY_TIMEOUT,
1630         FAILURE_SESSION_LOGGING_OUT,
1631         FAILURE_SESSION_NOT_READY,
1632 };
1633
1634 int iscsi_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *sc)
1635 {
1636         struct iscsi_cls_session *cls_session;
1637         struct iscsi_host *ihost;
1638         int reason = 0;
1639         struct iscsi_session *session;
1640         struct iscsi_conn *conn;
1641         struct iscsi_task *task = NULL;
1642
1643         sc->result = 0;
1644         sc->SCp.ptr = NULL;
1645
1646         ihost = shost_priv(host);
1647
1648         cls_session = starget_to_session(scsi_target(sc->device));
1649         session = cls_session->dd_data;
1650         spin_lock_bh(&session->frwd_lock);
1651
1652         reason = iscsi_session_chkready(cls_session);
1653         if (reason) {
1654                 sc->result = reason;
1655                 goto fault;
1656         }
1657
1658         if (session->state != ISCSI_STATE_LOGGED_IN) {
1659                 /*
1660                  * to handle the race between when we set the recovery state
1661                  * and block the session we requeue here (commands could
1662                  * be entering our queuecommand while a block is starting
1663                  * up because the block code is not locked)
1664                  */
1665                 switch (session->state) {
1666                 case ISCSI_STATE_FAILED:
1667                 case ISCSI_STATE_IN_RECOVERY:
1668                         reason = FAILURE_SESSION_IN_RECOVERY;
1669                         sc->result = DID_IMM_RETRY << 16;
1670                         break;
1671                 case ISCSI_STATE_LOGGING_OUT:
1672                         reason = FAILURE_SESSION_LOGGING_OUT;
1673                         sc->result = DID_IMM_RETRY << 16;
1674                         break;
1675                 case ISCSI_STATE_RECOVERY_FAILED:
1676                         reason = FAILURE_SESSION_RECOVERY_TIMEOUT;
1677                         sc->result = DID_TRANSPORT_FAILFAST << 16;
1678                         break;
1679                 case ISCSI_STATE_TERMINATE:
1680                         reason = FAILURE_SESSION_TERMINATE;
1681                         sc->result = DID_NO_CONNECT << 16;
1682                         break;
1683                 default:
1684                         reason = FAILURE_SESSION_FREED;
1685                         sc->result = DID_NO_CONNECT << 16;
1686                 }
1687                 goto fault;
1688         }
1689
1690         conn = session->leadconn;
1691         if (!conn) {
1692                 reason = FAILURE_SESSION_FREED;
1693                 sc->result = DID_NO_CONNECT << 16;
1694                 goto fault;
1695         }
1696
1697         if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx)) {
1698                 reason = FAILURE_SESSION_IN_RECOVERY;
1699                 sc->result = DID_REQUEUE;
1700                 goto fault;
1701         }
1702
1703         if (iscsi_check_cmdsn_window_closed(conn)) {
1704                 reason = FAILURE_WINDOW_CLOSED;
1705                 goto reject;
1706         }
1707
1708         task = iscsi_alloc_task(conn, sc);
1709         if (!task) {
1710                 reason = FAILURE_OOM;
1711                 goto reject;
1712         }
1713
1714         if (!ihost->workq) {
1715                 reason = iscsi_prep_scsi_cmd_pdu(task);
1716                 if (reason) {
1717                         if (reason == -ENOMEM ||  reason == -EACCES) {
1718                                 reason = FAILURE_OOM;
1719                                 goto prepd_reject;
1720                         } else {
1721                                 sc->result = DID_ABORT << 16;
1722                                 goto prepd_fault;
1723                         }
1724                 }
1725                 if (session->tt->xmit_task(task)) {
1726                         session->cmdsn--;
1727                         reason = FAILURE_SESSION_NOT_READY;
1728                         goto prepd_reject;
1729                 }
1730         } else {
1731                 list_add_tail(&task->running, &conn->cmdqueue);
1732                 iscsi_conn_queue_work(conn);
1733         }
1734
1735         session->queued_cmdsn++;
1736         spin_unlock_bh(&session->frwd_lock);
1737         return 0;
1738
1739 prepd_reject:
1740         iscsi_complete_task(task, ISCSI_TASK_REQUEUE_SCSIQ);
1741 reject:
1742         spin_unlock_bh(&session->frwd_lock);
1743         ISCSI_DBG_SESSION(session, "cmd 0x%x rejected (%d)\n",
1744                           sc->cmnd[0], reason);
1745         return SCSI_MLQUEUE_TARGET_BUSY;
1746
1747 prepd_fault:
1748         iscsi_complete_task(task, ISCSI_TASK_REQUEUE_SCSIQ);
1749 fault:
1750         spin_unlock_bh(&session->frwd_lock);
1751         ISCSI_DBG_SESSION(session, "iscsi: cmd 0x%x is not queued (%d)\n",
1752                           sc->cmnd[0], reason);
1753         if (!scsi_bidi_cmnd(sc))
1754                 scsi_set_resid(sc, scsi_bufflen(sc));
1755         else {
1756                 scsi_out(sc)->resid = scsi_out(sc)->length;
1757                 scsi_in(sc)->resid = scsi_in(sc)->length;
1758         }
1759         sc->scsi_done(sc);
1760         return 0;
1761 }
1762 EXPORT_SYMBOL_GPL(iscsi_queuecommand);
1763
1764 int iscsi_change_queue_depth(struct scsi_device *sdev, int depth, int reason)
1765 {
1766         switch (reason) {
1767         case SCSI_QDEPTH_DEFAULT:
1768                 scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
1769                 break;
1770         case SCSI_QDEPTH_QFULL:
1771                 scsi_track_queue_full(sdev, depth);
1772                 break;
1773         case SCSI_QDEPTH_RAMP_UP:
1774                 scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
1775                 break;
1776         default:
1777                 return -EOPNOTSUPP;
1778         }
1779         return sdev->queue_depth;
1780 }
1781 EXPORT_SYMBOL_GPL(iscsi_change_queue_depth);
1782
1783 int iscsi_target_alloc(struct scsi_target *starget)
1784 {
1785         struct iscsi_cls_session *cls_session = starget_to_session(starget);
1786         struct iscsi_session *session = cls_session->dd_data;
1787
1788         starget->can_queue = session->scsi_cmds_max;
1789         return 0;
1790 }
1791 EXPORT_SYMBOL_GPL(iscsi_target_alloc);
1792
1793 static void iscsi_tmf_timedout(unsigned long data)
1794 {
1795         struct iscsi_conn *conn = (struct iscsi_conn *)data;
1796         struct iscsi_session *session = conn->session;
1797
1798         spin_lock(&session->frwd_lock);
1799         if (conn->tmf_state == TMF_QUEUED) {
1800                 conn->tmf_state = TMF_TIMEDOUT;
1801                 ISCSI_DBG_EH(session, "tmf timedout\n");
1802                 /* unblock eh_abort() */
1803                 wake_up(&conn->ehwait);
1804         }
1805         spin_unlock(&session->frwd_lock);
1806 }
1807
1808 static int iscsi_exec_task_mgmt_fn(struct iscsi_conn *conn,
1809                                    struct iscsi_tm *hdr, int age,
1810                                    int timeout)
1811 {
1812         struct iscsi_session *session = conn->session;
1813         struct iscsi_task *task;
1814
1815         task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)hdr,
1816                                       NULL, 0);
1817         if (!task) {
1818                 spin_unlock_bh(&session->frwd_lock);
1819                 iscsi_conn_printk(KERN_ERR, conn, "Could not send TMF.\n");
1820                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1821                 spin_lock_bh(&session->frwd_lock);
1822                 return -EPERM;
1823         }
1824         conn->tmfcmd_pdus_cnt++;
1825         conn->tmf_timer.expires = timeout * HZ + jiffies;
1826         conn->tmf_timer.function = iscsi_tmf_timedout;
1827         conn->tmf_timer.data = (unsigned long)conn;
1828         add_timer(&conn->tmf_timer);
1829         ISCSI_DBG_EH(session, "tmf set timeout\n");
1830
1831         spin_unlock_bh(&session->frwd_lock);
1832         mutex_unlock(&session->eh_mutex);
1833
1834         /*
1835          * block eh thread until:
1836          *
1837          * 1) tmf response
1838          * 2) tmf timeout
1839          * 3) session is terminated or restarted or userspace has
1840          * given up on recovery
1841          */
1842         wait_event_interruptible(conn->ehwait, age != session->age ||
1843                                  session->state != ISCSI_STATE_LOGGED_IN ||
1844                                  conn->tmf_state != TMF_QUEUED);
1845         if (signal_pending(current))
1846                 flush_signals(current);
1847         del_timer_sync(&conn->tmf_timer);
1848
1849         mutex_lock(&session->eh_mutex);
1850         spin_lock_bh(&session->frwd_lock);
1851         /* if the session drops it will clean up the task */
1852         if (age != session->age ||
1853             session->state != ISCSI_STATE_LOGGED_IN)
1854                 return -ENOTCONN;
1855         return 0;
1856 }
1857
1858 /*
1859  * Fail commands. session lock held and recv side suspended and xmit
1860  * thread flushed
1861  */
1862 static void fail_scsi_tasks(struct iscsi_conn *conn, u64 lun, int error)
1863 {
1864         struct iscsi_task *task;
1865         int i;
1866
1867         for (i = 0; i < conn->session->cmds_max; i++) {
1868                 task = conn->session->cmds[i];
1869                 if (!task->sc || task->state == ISCSI_TASK_FREE)
1870                         continue;
1871
1872                 if (lun != -1 && lun != task->sc->device->lun)
1873                         continue;
1874
1875                 ISCSI_DBG_SESSION(conn->session,
1876                                   "failing sc %p itt 0x%x state %d\n",
1877                                   task->sc, task->itt, task->state);
1878                 fail_scsi_task(task, error);
1879         }
1880 }
1881
1882 /**
1883  * iscsi_suspend_queue - suspend iscsi_queuecommand
1884  * @conn: iscsi conn to stop queueing IO on
1885  *
1886  * This grabs the session frwd_lock to make sure no one is in
1887  * xmit_task/queuecommand, and then sets suspend to prevent
1888  * new commands from being queued. This only needs to be called
1889  * by offload drivers that need to sync a path like ep disconnect
1890  * with the iscsi_queuecommand/xmit_task. To start IO again libiscsi
1891  * will call iscsi_start_tx and iscsi_unblock_session when in FFP.
1892  */
1893 void iscsi_suspend_queue(struct iscsi_conn *conn)
1894 {
1895         spin_lock_bh(&conn->session->frwd_lock);
1896         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1897         spin_unlock_bh(&conn->session->frwd_lock);
1898 }
1899 EXPORT_SYMBOL_GPL(iscsi_suspend_queue);
1900
1901 /**
1902  * iscsi_suspend_tx - suspend iscsi_data_xmit
1903  * @conn: iscsi conn tp stop processing IO on.
1904  *
1905  * This function sets the suspend bit to prevent iscsi_data_xmit
1906  * from sending new IO, and if work is queued on the xmit thread
1907  * it will wait for it to be completed.
1908  */
1909 void iscsi_suspend_tx(struct iscsi_conn *conn)
1910 {
1911         struct Scsi_Host *shost = conn->session->host;
1912         struct iscsi_host *ihost = shost_priv(shost);
1913
1914         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1915         if (ihost->workq)
1916                 flush_workqueue(ihost->workq);
1917 }
1918 EXPORT_SYMBOL_GPL(iscsi_suspend_tx);
1919
1920 static void iscsi_start_tx(struct iscsi_conn *conn)
1921 {
1922         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1923         iscsi_conn_queue_work(conn);
1924 }
1925
1926 /*
1927  * We want to make sure a ping is in flight. It has timed out.
1928  * And we are not busy processing a pdu that is making
1929  * progress but got started before the ping and is taking a while
1930  * to complete so the ping is just stuck behind it in a queue.
1931  */
1932 static int iscsi_has_ping_timed_out(struct iscsi_conn *conn)
1933 {
1934         if (conn->ping_task &&
1935             time_before_eq(conn->last_recv + (conn->recv_timeout * HZ) +
1936                            (conn->ping_timeout * HZ), jiffies))
1937                 return 1;
1938         else
1939                 return 0;
1940 }
1941
1942 static enum blk_eh_timer_return iscsi_eh_cmd_timed_out(struct scsi_cmnd *sc)
1943 {
1944         enum blk_eh_timer_return rc = BLK_EH_NOT_HANDLED;
1945         struct iscsi_task *task = NULL, *running_task;
1946         struct iscsi_cls_session *cls_session;
1947         struct iscsi_session *session;
1948         struct iscsi_conn *conn;
1949         int i;
1950
1951         cls_session = starget_to_session(scsi_target(sc->device));
1952         session = cls_session->dd_data;
1953
1954         ISCSI_DBG_EH(session, "scsi cmd %p timedout\n", sc);
1955
1956         spin_lock(&session->frwd_lock);
1957         task = (struct iscsi_task *)sc->SCp.ptr;
1958         if (!task) {
1959                 /*
1960                  * Raced with completion. Blk layer has taken ownership
1961                  * so let timeout code complete it now.
1962                  */
1963                 rc = BLK_EH_HANDLED;
1964                 goto done;
1965         }
1966
1967         if (session->state != ISCSI_STATE_LOGGED_IN) {
1968                 /*
1969                  * We are probably in the middle of iscsi recovery so let
1970                  * that complete and handle the error.
1971                  */
1972                 rc = BLK_EH_RESET_TIMER;
1973                 goto done;
1974         }
1975
1976         conn = session->leadconn;
1977         if (!conn) {
1978                 /* In the middle of shuting down */
1979                 rc = BLK_EH_RESET_TIMER;
1980                 goto done;
1981         }
1982
1983         /*
1984          * If we have sent (at least queued to the network layer) a pdu or
1985          * recvd one for the task since the last timeout ask for
1986          * more time. If on the next timeout we have not made progress
1987          * we can check if it is the task or connection when we send the
1988          * nop as a ping.
1989          */
1990         if (time_after(task->last_xfer, task->last_timeout)) {
1991                 ISCSI_DBG_EH(session, "Command making progress. Asking "
1992                              "scsi-ml for more time to complete. "
1993                              "Last data xfer at %lu. Last timeout was at "
1994                              "%lu\n.", task->last_xfer, task->last_timeout);
1995                 task->have_checked_conn = false;
1996                 rc = BLK_EH_RESET_TIMER;
1997                 goto done;
1998         }
1999
2000         if (!conn->recv_timeout && !conn->ping_timeout)
2001                 goto done;
2002         /*
2003          * if the ping timedout then we are in the middle of cleaning up
2004          * and can let the iscsi eh handle it
2005          */
2006         if (iscsi_has_ping_timed_out(conn)) {
2007                 rc = BLK_EH_RESET_TIMER;
2008                 goto done;
2009         }
2010
2011         for (i = 0; i < conn->session->cmds_max; i++) {
2012                 running_task = conn->session->cmds[i];
2013                 if (!running_task->sc || running_task == task ||
2014                      running_task->state != ISCSI_TASK_RUNNING)
2015                         continue;
2016
2017                 /*
2018                  * Only check if cmds started before this one have made
2019                  * progress, or this could never fail
2020                  */
2021                 if (time_after(running_task->sc->jiffies_at_alloc,
2022                                task->sc->jiffies_at_alloc))
2023                         continue;
2024
2025                 if (time_after(running_task->last_xfer, task->last_timeout)) {
2026                         /*
2027                          * This task has not made progress, but a task
2028                          * started before us has transferred data since
2029                          * we started/last-checked. We could be queueing
2030                          * too many tasks or the LU is bad.
2031                          *
2032                          * If the device is bad the cmds ahead of us on
2033                          * other devs will complete, and this loop will
2034                          * eventually fail starting the scsi eh.
2035                          */
2036                         ISCSI_DBG_EH(session, "Command has not made progress "
2037                                      "but commands ahead of it have. "
2038                                      "Asking scsi-ml for more time to "
2039                                      "complete. Our last xfer vs running task "
2040                                      "last xfer %lu/%lu. Last check %lu.\n",
2041                                      task->last_xfer, running_task->last_xfer,
2042                                      task->last_timeout);
2043                         rc = BLK_EH_RESET_TIMER;
2044                         goto done;
2045                 }
2046         }
2047
2048         /* Assumes nop timeout is shorter than scsi cmd timeout */
2049         if (task->have_checked_conn)
2050                 goto done;
2051
2052         /*
2053          * Checking the transport already or nop from a cmd timeout still
2054          * running
2055          */
2056         if (conn->ping_task) {
2057                 task->have_checked_conn = true;
2058                 rc = BLK_EH_RESET_TIMER;
2059                 goto done;
2060         }
2061
2062         /* Make sure there is a transport check done */
2063         iscsi_send_nopout(conn, NULL);
2064         task->have_checked_conn = true;
2065         rc = BLK_EH_RESET_TIMER;
2066
2067 done:
2068         if (task)
2069                 task->last_timeout = jiffies;
2070         spin_unlock(&session->frwd_lock);
2071         ISCSI_DBG_EH(session, "return %s\n", rc == BLK_EH_RESET_TIMER ?
2072                      "timer reset" : "nh");
2073         return rc;
2074 }
2075
2076 static void iscsi_check_transport_timeouts(unsigned long data)
2077 {
2078         struct iscsi_conn *conn = (struct iscsi_conn *)data;
2079         struct iscsi_session *session = conn->session;
2080         unsigned long recv_timeout, next_timeout = 0, last_recv;
2081
2082         spin_lock(&session->frwd_lock);
2083         if (session->state != ISCSI_STATE_LOGGED_IN)
2084                 goto done;
2085
2086         recv_timeout = conn->recv_timeout;
2087         if (!recv_timeout)
2088                 goto done;
2089
2090         recv_timeout *= HZ;
2091         last_recv = conn->last_recv;
2092
2093         if (iscsi_has_ping_timed_out(conn)) {
2094                 iscsi_conn_printk(KERN_ERR, conn, "ping timeout of %d secs "
2095                                   "expired, recv timeout %d, last rx %lu, "
2096                                   "last ping %lu, now %lu\n",
2097                                   conn->ping_timeout, conn->recv_timeout,
2098                                   last_recv, conn->last_ping, jiffies);
2099                 spin_unlock(&session->frwd_lock);
2100                 iscsi_conn_failure(conn, ISCSI_ERR_NOP_TIMEDOUT);
2101                 return;
2102         }
2103
2104         if (time_before_eq(last_recv + recv_timeout, jiffies)) {
2105                 /* send a ping to try to provoke some traffic */
2106                 ISCSI_DBG_CONN(conn, "Sending nopout as ping\n");
2107                 iscsi_send_nopout(conn, NULL);
2108                 next_timeout = conn->last_ping + (conn->ping_timeout * HZ);
2109         } else
2110                 next_timeout = last_recv + recv_timeout;
2111
2112         ISCSI_DBG_CONN(conn, "Setting next tmo %lu\n", next_timeout);
2113         mod_timer(&conn->transport_timer, next_timeout);
2114 done:
2115         spin_unlock(&session->frwd_lock);
2116 }
2117
2118 static void iscsi_prep_abort_task_pdu(struct iscsi_task *task,
2119                                       struct iscsi_tm *hdr)
2120 {
2121         memset(hdr, 0, sizeof(*hdr));
2122         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2123         hdr->flags = ISCSI_TM_FUNC_ABORT_TASK & ISCSI_FLAG_TM_FUNC_MASK;
2124         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2125         hdr->lun = task->lun;
2126         hdr->rtt = task->hdr_itt;
2127         hdr->refcmdsn = task->cmdsn;
2128 }
2129
2130 int iscsi_eh_abort(struct scsi_cmnd *sc)
2131 {
2132         struct iscsi_cls_session *cls_session;
2133         struct iscsi_session *session;
2134         struct iscsi_conn *conn;
2135         struct iscsi_task *task;
2136         struct iscsi_tm *hdr;
2137         int rc, age;
2138
2139         cls_session = starget_to_session(scsi_target(sc->device));
2140         session = cls_session->dd_data;
2141
2142         ISCSI_DBG_EH(session, "aborting sc %p\n", sc);
2143
2144         mutex_lock(&session->eh_mutex);
2145         spin_lock_bh(&session->frwd_lock);
2146         /*
2147          * if session was ISCSI_STATE_IN_RECOVERY then we may not have
2148          * got the command.
2149          */
2150         if (!sc->SCp.ptr) {
2151                 ISCSI_DBG_EH(session, "sc never reached iscsi layer or "
2152                                       "it completed.\n");
2153                 spin_unlock_bh(&session->frwd_lock);
2154                 mutex_unlock(&session->eh_mutex);
2155                 return SUCCESS;
2156         }
2157
2158         /*
2159          * If we are not logged in or we have started a new session
2160          * then let the host reset code handle this
2161          */
2162         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN ||
2163             sc->SCp.phase != session->age) {
2164                 spin_unlock_bh(&session->frwd_lock);
2165                 mutex_unlock(&session->eh_mutex);
2166                 ISCSI_DBG_EH(session, "failing abort due to dropped "
2167                                   "session.\n");
2168                 return FAILED;
2169         }
2170
2171         conn = session->leadconn;
2172         conn->eh_abort_cnt++;
2173         age = session->age;
2174
2175         task = (struct iscsi_task *)sc->SCp.ptr;
2176         ISCSI_DBG_EH(session, "aborting [sc %p itt 0x%x]\n",
2177                      sc, task->itt);
2178
2179         /* task completed before time out */
2180         if (!task->sc) {
2181                 ISCSI_DBG_EH(session, "sc completed while abort in progress\n");
2182                 goto success;
2183         }
2184
2185         if (task->state == ISCSI_TASK_PENDING) {
2186                 fail_scsi_task(task, DID_ABORT);
2187                 goto success;
2188         }
2189
2190         /* only have one tmf outstanding at a time */
2191         if (conn->tmf_state != TMF_INITIAL)
2192                 goto failed;
2193         conn->tmf_state = TMF_QUEUED;
2194
2195         hdr = &conn->tmhdr;
2196         iscsi_prep_abort_task_pdu(task, hdr);
2197
2198         if (iscsi_exec_task_mgmt_fn(conn, hdr, age, session->abort_timeout)) {
2199                 rc = FAILED;
2200                 goto failed;
2201         }
2202
2203         switch (conn->tmf_state) {
2204         case TMF_SUCCESS:
2205                 spin_unlock_bh(&session->frwd_lock);
2206                 /*
2207                  * stop tx side incase the target had sent a abort rsp but
2208                  * the initiator was still writing out data.
2209                  */
2210                 iscsi_suspend_tx(conn);
2211                 /*
2212                  * we do not stop the recv side because targets have been
2213                  * good and have never sent us a successful tmf response
2214                  * then sent more data for the cmd.
2215                  */
2216                 spin_lock_bh(&session->frwd_lock);
2217                 fail_scsi_task(task, DID_ABORT);
2218                 conn->tmf_state = TMF_INITIAL;
2219                 memset(hdr, 0, sizeof(*hdr));
2220                 spin_unlock_bh(&session->frwd_lock);
2221                 iscsi_start_tx(conn);
2222                 goto success_unlocked;
2223         case TMF_TIMEDOUT:
2224                 spin_unlock_bh(&session->frwd_lock);
2225                 iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2226                 goto failed_unlocked;
2227         case TMF_NOT_FOUND:
2228                 if (!sc->SCp.ptr) {
2229                         conn->tmf_state = TMF_INITIAL;
2230                         memset(hdr, 0, sizeof(*hdr));
2231                         /* task completed before tmf abort response */
2232                         ISCSI_DBG_EH(session, "sc completed while abort in "
2233                                               "progress\n");
2234                         goto success;
2235                 }
2236                 /* fall through */
2237         default:
2238                 conn->tmf_state = TMF_INITIAL;
2239                 goto failed;
2240         }
2241
2242 success:
2243         spin_unlock_bh(&session->frwd_lock);
2244 success_unlocked:
2245         ISCSI_DBG_EH(session, "abort success [sc %p itt 0x%x]\n",
2246                      sc, task->itt);
2247         mutex_unlock(&session->eh_mutex);
2248         return SUCCESS;
2249
2250 failed:
2251         spin_unlock_bh(&session->frwd_lock);
2252 failed_unlocked:
2253         ISCSI_DBG_EH(session, "abort failed [sc %p itt 0x%x]\n", sc,
2254                      task ? task->itt : 0);
2255         mutex_unlock(&session->eh_mutex);
2256         return FAILED;
2257 }
2258 EXPORT_SYMBOL_GPL(iscsi_eh_abort);
2259
2260 static void iscsi_prep_lun_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
2261 {
2262         memset(hdr, 0, sizeof(*hdr));
2263         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2264         hdr->flags = ISCSI_TM_FUNC_LOGICAL_UNIT_RESET & ISCSI_FLAG_TM_FUNC_MASK;
2265         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2266         int_to_scsilun(sc->device->lun, &hdr->lun);
2267         hdr->rtt = RESERVED_ITT;
2268 }
2269
2270 int iscsi_eh_device_reset(struct scsi_cmnd *sc)
2271 {
2272         struct iscsi_cls_session *cls_session;
2273         struct iscsi_session *session;
2274         struct iscsi_conn *conn;
2275         struct iscsi_tm *hdr;
2276         int rc = FAILED;
2277
2278         cls_session = starget_to_session(scsi_target(sc->device));
2279         session = cls_session->dd_data;
2280
2281         ISCSI_DBG_EH(session, "LU Reset [sc %p lun %llu]\n", sc,
2282                      sc->device->lun);
2283
2284         mutex_lock(&session->eh_mutex);
2285         spin_lock_bh(&session->frwd_lock);
2286         /*
2287          * Just check if we are not logged in. We cannot check for
2288          * the phase because the reset could come from a ioctl.
2289          */
2290         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
2291                 goto unlock;
2292         conn = session->leadconn;
2293
2294         /* only have one tmf outstanding at a time */
2295         if (conn->tmf_state != TMF_INITIAL)
2296                 goto unlock;
2297         conn->tmf_state = TMF_QUEUED;
2298
2299         hdr = &conn->tmhdr;
2300         iscsi_prep_lun_reset_pdu(sc, hdr);
2301
2302         if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
2303                                     session->lu_reset_timeout)) {
2304                 rc = FAILED;
2305                 goto unlock;
2306         }
2307
2308         switch (conn->tmf_state) {
2309         case TMF_SUCCESS:
2310                 break;
2311         case TMF_TIMEDOUT:
2312                 spin_unlock_bh(&session->frwd_lock);
2313                 iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2314                 goto done;
2315         default:
2316                 conn->tmf_state = TMF_INITIAL;
2317                 goto unlock;
2318         }
2319
2320         rc = SUCCESS;
2321         spin_unlock_bh(&session->frwd_lock);
2322
2323         iscsi_suspend_tx(conn);
2324
2325         spin_lock_bh(&session->frwd_lock);
2326         memset(hdr, 0, sizeof(*hdr));
2327         fail_scsi_tasks(conn, sc->device->lun, DID_ERROR);
2328         conn->tmf_state = TMF_INITIAL;
2329         spin_unlock_bh(&session->frwd_lock);
2330
2331         iscsi_start_tx(conn);
2332         goto done;
2333
2334 unlock:
2335         spin_unlock_bh(&session->frwd_lock);
2336 done:
2337         ISCSI_DBG_EH(session, "dev reset result = %s\n",
2338                      rc == SUCCESS ? "SUCCESS" : "FAILED");
2339         mutex_unlock(&session->eh_mutex);
2340         return rc;
2341 }
2342 EXPORT_SYMBOL_GPL(iscsi_eh_device_reset);
2343
2344 void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
2345 {
2346         struct iscsi_session *session = cls_session->dd_data;
2347
2348         spin_lock_bh(&session->frwd_lock);
2349         if (session->state != ISCSI_STATE_LOGGED_IN) {
2350                 session->state = ISCSI_STATE_RECOVERY_FAILED;
2351                 if (session->leadconn)
2352                         wake_up(&session->leadconn->ehwait);
2353         }
2354         spin_unlock_bh(&session->frwd_lock);
2355 }
2356 EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
2357
2358 /**
2359  * iscsi_eh_session_reset - drop session and attempt relogin
2360  * @sc: scsi command
2361  *
2362  * This function will wait for a relogin, session termination from
2363  * userspace, or a recovery/replacement timeout.
2364  */
2365 int iscsi_eh_session_reset(struct scsi_cmnd *sc)
2366 {
2367         struct iscsi_cls_session *cls_session;
2368         struct iscsi_session *session;
2369         struct iscsi_conn *conn;
2370
2371         cls_session = starget_to_session(scsi_target(sc->device));
2372         session = cls_session->dd_data;
2373         conn = session->leadconn;
2374
2375         mutex_lock(&session->eh_mutex);
2376         spin_lock_bh(&session->frwd_lock);
2377         if (session->state == ISCSI_STATE_TERMINATE) {
2378 failed:
2379                 ISCSI_DBG_EH(session,
2380                              "failing session reset: Could not log back into "
2381                              "%s, %s [age %d]\n", session->targetname,
2382                              conn->persistent_address, session->age);
2383                 spin_unlock_bh(&session->frwd_lock);
2384                 mutex_unlock(&session->eh_mutex);
2385                 return FAILED;
2386         }
2387
2388         spin_unlock_bh(&session->frwd_lock);
2389         mutex_unlock(&session->eh_mutex);
2390         /*
2391          * we drop the lock here but the leadconn cannot be destoyed while
2392          * we are in the scsi eh
2393          */
2394         iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2395
2396         ISCSI_DBG_EH(session, "wait for relogin\n");
2397         wait_event_interruptible(conn->ehwait,
2398                                  session->state == ISCSI_STATE_TERMINATE ||
2399                                  session->state == ISCSI_STATE_LOGGED_IN ||
2400                                  session->state == ISCSI_STATE_RECOVERY_FAILED);
2401         if (signal_pending(current))
2402                 flush_signals(current);
2403
2404         mutex_lock(&session->eh_mutex);
2405         spin_lock_bh(&session->frwd_lock);
2406         if (session->state == ISCSI_STATE_LOGGED_IN) {
2407                 ISCSI_DBG_EH(session,
2408                              "session reset succeeded for %s,%s\n",
2409                              session->targetname, conn->persistent_address);
2410         } else
2411                 goto failed;
2412         spin_unlock_bh(&session->frwd_lock);
2413         mutex_unlock(&session->eh_mutex);
2414         return SUCCESS;
2415 }
2416 EXPORT_SYMBOL_GPL(iscsi_eh_session_reset);
2417
2418 static void iscsi_prep_tgt_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
2419 {
2420         memset(hdr, 0, sizeof(*hdr));
2421         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2422         hdr->flags = ISCSI_TM_FUNC_TARGET_WARM_RESET & ISCSI_FLAG_TM_FUNC_MASK;
2423         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2424         hdr->rtt = RESERVED_ITT;
2425 }
2426
2427 /**
2428  * iscsi_eh_target_reset - reset target
2429  * @sc: scsi command
2430  *
2431  * This will attempt to send a warm target reset.
2432  */
2433 int iscsi_eh_target_reset(struct scsi_cmnd *sc)
2434 {
2435         struct iscsi_cls_session *cls_session;
2436         struct iscsi_session *session;
2437         struct iscsi_conn *conn;
2438         struct iscsi_tm *hdr;
2439         int rc = FAILED;
2440
2441         cls_session = starget_to_session(scsi_target(sc->device));
2442         session = cls_session->dd_data;
2443
2444         ISCSI_DBG_EH(session, "tgt Reset [sc %p tgt %s]\n", sc,
2445                      session->targetname);
2446
2447         mutex_lock(&session->eh_mutex);
2448         spin_lock_bh(&session->frwd_lock);
2449         /*
2450          * Just check if we are not logged in. We cannot check for
2451          * the phase because the reset could come from a ioctl.
2452          */
2453         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
2454                 goto unlock;
2455         conn = session->leadconn;
2456
2457         /* only have one tmf outstanding at a time */
2458         if (conn->tmf_state != TMF_INITIAL)
2459                 goto unlock;
2460         conn->tmf_state = TMF_QUEUED;
2461
2462         hdr = &conn->tmhdr;
2463         iscsi_prep_tgt_reset_pdu(sc, hdr);
2464
2465         if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
2466                                     session->tgt_reset_timeout)) {
2467                 rc = FAILED;
2468                 goto unlock;
2469         }
2470
2471         switch (conn->tmf_state) {
2472         case TMF_SUCCESS:
2473                 break;
2474         case TMF_TIMEDOUT:
2475                 spin_unlock_bh(&session->frwd_lock);
2476                 iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2477                 goto done;
2478         default:
2479                 conn->tmf_state = TMF_INITIAL;
2480                 goto unlock;
2481         }
2482
2483         rc = SUCCESS;
2484         spin_unlock_bh(&session->frwd_lock);
2485
2486         iscsi_suspend_tx(conn);
2487
2488         spin_lock_bh(&session->frwd_lock);
2489         memset(hdr, 0, sizeof(*hdr));
2490         fail_scsi_tasks(conn, -1, DID_ERROR);
2491         conn->tmf_state = TMF_INITIAL;
2492         spin_unlock_bh(&session->frwd_lock);
2493
2494         iscsi_start_tx(conn);
2495         goto done;
2496
2497 unlock:
2498         spin_unlock_bh(&session->frwd_lock);
2499 done:
2500         ISCSI_DBG_EH(session, "tgt %s reset result = %s\n", session->targetname,
2501                      rc == SUCCESS ? "SUCCESS" : "FAILED");
2502         mutex_unlock(&session->eh_mutex);
2503         return rc;
2504 }
2505 EXPORT_SYMBOL_GPL(iscsi_eh_target_reset);
2506
2507 /**
2508  * iscsi_eh_recover_target - reset target and possibly the session
2509  * @sc: scsi command
2510  *
2511  * This will attempt to send a warm target reset. If that fails,
2512  * we will escalate to ERL0 session recovery.
2513  */
2514 int iscsi_eh_recover_target(struct scsi_cmnd *sc)
2515 {
2516         int rc;
2517
2518         rc = iscsi_eh_target_reset(sc);
2519         if (rc == FAILED)
2520                 rc = iscsi_eh_session_reset(sc);
2521         return rc;
2522 }
2523 EXPORT_SYMBOL_GPL(iscsi_eh_recover_target);
2524
2525 /*
2526  * Pre-allocate a pool of @max items of @item_size. By default, the pool
2527  * should be accessed via kfifo_{get,put} on q->queue.
2528  * Optionally, the caller can obtain the array of object pointers
2529  * by passing in a non-NULL @items pointer
2530  */
2531 int
2532 iscsi_pool_init(struct iscsi_pool *q, int max, void ***items, int item_size)
2533 {
2534         int i, num_arrays = 1;
2535
2536         memset(q, 0, sizeof(*q));
2537
2538         q->max = max;
2539
2540         /* If the user passed an items pointer, he wants a copy of
2541          * the array. */
2542         if (items)
2543                 num_arrays++;
2544         q->pool = kzalloc(num_arrays * max * sizeof(void*), GFP_KERNEL);
2545         if (q->pool == NULL)
2546                 return -ENOMEM;
2547
2548         kfifo_init(&q->queue, (void*)q->pool, max * sizeof(void*));
2549
2550         for (i = 0; i < max; i++) {
2551                 q->pool[i] = kzalloc(item_size, GFP_KERNEL);
2552                 if (q->pool[i] == NULL) {
2553                         q->max = i;
2554                         goto enomem;
2555                 }
2556                 kfifo_in(&q->queue, (void*)&q->pool[i], sizeof(void*));
2557         }
2558
2559         if (items) {
2560                 *items = q->pool + max;
2561                 memcpy(*items, q->pool, max * sizeof(void *));
2562         }
2563
2564         return 0;
2565
2566 enomem:
2567         iscsi_pool_free(q);
2568         return -ENOMEM;
2569 }
2570 EXPORT_SYMBOL_GPL(iscsi_pool_init);
2571
2572 void iscsi_pool_free(struct iscsi_pool *q)
2573 {
2574         int i;
2575
2576         for (i = 0; i < q->max; i++)
2577                 kfree(q->pool[i]);
2578         kfree(q->pool);
2579 }
2580 EXPORT_SYMBOL_GPL(iscsi_pool_free);
2581
2582 /**
2583  * iscsi_host_add - add host to system
2584  * @shost: scsi host
2585  * @pdev: parent device
2586  *
2587  * This should be called by partial offload and software iscsi drivers
2588  * to add a host to the system.
2589  */
2590 int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev)
2591 {
2592         if (!shost->can_queue)
2593                 shost->can_queue = ISCSI_DEF_XMIT_CMDS_MAX;
2594
2595         if (!shost->cmd_per_lun)
2596                 shost->cmd_per_lun = ISCSI_DEF_CMD_PER_LUN;
2597
2598         if (!shost->transportt->eh_timed_out)
2599                 shost->transportt->eh_timed_out = iscsi_eh_cmd_timed_out;
2600         return scsi_add_host(shost, pdev);
2601 }
2602 EXPORT_SYMBOL_GPL(iscsi_host_add);
2603
2604 /**
2605  * iscsi_host_alloc - allocate a host and driver data
2606  * @sht: scsi host template
2607  * @dd_data_size: driver host data size
2608  * @xmit_can_sleep: bool indicating if LLD will queue IO from a work queue
2609  *
2610  * This should be called by partial offload and software iscsi drivers.
2611  * To access the driver specific memory use the iscsi_host_priv() macro.
2612  */
2613 struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
2614                                    int dd_data_size, bool xmit_can_sleep)
2615 {
2616         struct Scsi_Host *shost;
2617         struct iscsi_host *ihost;
2618
2619         shost = scsi_host_alloc(sht, sizeof(struct iscsi_host) + dd_data_size);
2620         if (!shost)
2621                 return NULL;
2622         ihost = shost_priv(shost);
2623
2624         if (xmit_can_sleep) {
2625                 snprintf(ihost->workq_name, sizeof(ihost->workq_name),
2626                         "iscsi_q_%d", shost->host_no);
2627                 ihost->workq = create_singlethread_workqueue(ihost->workq_name);
2628                 if (!ihost->workq)
2629                         goto free_host;
2630         }
2631
2632         spin_lock_init(&ihost->lock);
2633         ihost->state = ISCSI_HOST_SETUP;
2634         ihost->num_sessions = 0;
2635         init_waitqueue_head(&ihost->session_removal_wq);
2636         return shost;
2637
2638 free_host:
2639         scsi_host_put(shost);
2640         return NULL;
2641 }
2642 EXPORT_SYMBOL_GPL(iscsi_host_alloc);
2643
2644 static void iscsi_notify_host_removed(struct iscsi_cls_session *cls_session)
2645 {
2646         iscsi_session_failure(cls_session->dd_data, ISCSI_ERR_INVALID_HOST);
2647 }
2648
2649 /**
2650  * iscsi_host_remove - remove host and sessions
2651  * @shost: scsi host
2652  *
2653  * If there are any sessions left, this will initiate the removal and wait
2654  * for the completion.
2655  */
2656 void iscsi_host_remove(struct Scsi_Host *shost)
2657 {
2658         struct iscsi_host *ihost = shost_priv(shost);
2659         unsigned long flags;
2660
2661         spin_lock_irqsave(&ihost->lock, flags);
2662         ihost->state = ISCSI_HOST_REMOVED;
2663         spin_unlock_irqrestore(&ihost->lock, flags);
2664
2665         iscsi_host_for_each_session(shost, iscsi_notify_host_removed);
2666         wait_event_interruptible(ihost->session_removal_wq,
2667                                  ihost->num_sessions == 0);
2668         if (signal_pending(current))
2669                 flush_signals(current);
2670
2671         scsi_remove_host(shost);
2672         if (ihost->workq)
2673                 destroy_workqueue(ihost->workq);
2674 }
2675 EXPORT_SYMBOL_GPL(iscsi_host_remove);
2676
2677 void iscsi_host_free(struct Scsi_Host *shost)
2678 {
2679         struct iscsi_host *ihost = shost_priv(shost);
2680
2681         kfree(ihost->netdev);
2682         kfree(ihost->hwaddress);
2683         kfree(ihost->initiatorname);
2684         scsi_host_put(shost);
2685 }
2686 EXPORT_SYMBOL_GPL(iscsi_host_free);
2687
2688 static void iscsi_host_dec_session_cnt(struct Scsi_Host *shost)
2689 {
2690         struct iscsi_host *ihost = shost_priv(shost);
2691         unsigned long flags;
2692
2693         shost = scsi_host_get(shost);
2694         if (!shost) {
2695                 printk(KERN_ERR "Invalid state. Cannot notify host removal "
2696                       "of session teardown event because host already "
2697                       "removed.\n");
2698                 return;
2699         }
2700
2701         spin_lock_irqsave(&ihost->lock, flags);
2702         ihost->num_sessions--;
2703         if (ihost->num_sessions == 0)
2704                 wake_up(&ihost->session_removal_wq);
2705         spin_unlock_irqrestore(&ihost->lock, flags);
2706         scsi_host_put(shost);
2707 }
2708
2709 /**
2710  * iscsi_session_setup - create iscsi cls session and host and session
2711  * @iscsit: iscsi transport template
2712  * @shost: scsi host
2713  * @cmds_max: session can queue
2714  * @cmd_task_size: LLD task private data size
2715  * @initial_cmdsn: initial CmdSN
2716  *
2717  * This can be used by software iscsi_transports that allocate
2718  * a session per scsi host.
2719  *
2720  * Callers should set cmds_max to the largest total numer (mgmt + scsi) of
2721  * tasks they support. The iscsi layer reserves ISCSI_MGMT_CMDS_MAX tasks
2722  * for nop handling and login/logout requests.
2723  */
2724 struct iscsi_cls_session *
2725 iscsi_session_setup(struct iscsi_transport *iscsit, struct Scsi_Host *shost,
2726                     uint16_t cmds_max, int dd_size, int cmd_task_size,
2727                     uint32_t initial_cmdsn, unsigned int id)
2728 {
2729         struct iscsi_host *ihost = shost_priv(shost);
2730         struct iscsi_session *session;
2731         struct iscsi_cls_session *cls_session;
2732         int cmd_i, scsi_cmds, total_cmds = cmds_max;
2733         unsigned long flags;
2734
2735         spin_lock_irqsave(&ihost->lock, flags);
2736         if (ihost->state == ISCSI_HOST_REMOVED) {
2737                 spin_unlock_irqrestore(&ihost->lock, flags);
2738                 return NULL;
2739         }
2740         ihost->num_sessions++;
2741         spin_unlock_irqrestore(&ihost->lock, flags);
2742
2743         if (!total_cmds)
2744                 total_cmds = ISCSI_DEF_XMIT_CMDS_MAX;
2745         /*
2746          * The iscsi layer needs some tasks for nop handling and tmfs,
2747          * so the cmds_max must at least be greater than ISCSI_MGMT_CMDS_MAX
2748          * + 1 command for scsi IO.
2749          */
2750         if (total_cmds < ISCSI_TOTAL_CMDS_MIN) {
2751                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2752                        "must be a power of two that is at least %d.\n",
2753                        total_cmds, ISCSI_TOTAL_CMDS_MIN);
2754                 goto dec_session_count;
2755         }
2756
2757         if (total_cmds > ISCSI_TOTAL_CMDS_MAX) {
2758                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2759                        "must be a power of 2 less than or equal to %d.\n",
2760                        cmds_max, ISCSI_TOTAL_CMDS_MAX);
2761                 total_cmds = ISCSI_TOTAL_CMDS_MAX;
2762         }
2763
2764         if (!is_power_of_2(total_cmds)) {
2765                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2766                        "must be a power of 2.\n", total_cmds);
2767                 total_cmds = rounddown_pow_of_two(total_cmds);
2768                 if (total_cmds < ISCSI_TOTAL_CMDS_MIN)
2769                         return NULL;
2770                 printk(KERN_INFO "iscsi: Rounding can_queue to %d.\n",
2771                        total_cmds);
2772         }
2773         scsi_cmds = total_cmds - ISCSI_MGMT_CMDS_MAX;
2774
2775         cls_session = iscsi_alloc_session(shost, iscsit,
2776                                           sizeof(struct iscsi_session) +
2777                                           dd_size);
2778         if (!cls_session)
2779                 goto dec_session_count;
2780         session = cls_session->dd_data;
2781         session->cls_session = cls_session;
2782         session->host = shost;
2783         session->state = ISCSI_STATE_FREE;
2784         session->fast_abort = 1;
2785         session->tgt_reset_timeout = 30;
2786         session->lu_reset_timeout = 15;
2787         session->abort_timeout = 10;
2788         session->scsi_cmds_max = scsi_cmds;
2789         session->cmds_max = total_cmds;
2790         session->queued_cmdsn = session->cmdsn = initial_cmdsn;
2791         session->exp_cmdsn = initial_cmdsn + 1;
2792         session->max_cmdsn = initial_cmdsn + 1;
2793         session->max_r2t = 1;
2794         session->tt = iscsit;
2795         session->dd_data = cls_session->dd_data + sizeof(*session);
2796
2797         mutex_init(&session->eh_mutex);
2798         spin_lock_init(&session->frwd_lock);
2799         spin_lock_init(&session->back_lock);
2800
2801         /* initialize SCSI PDU commands pool */
2802         if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
2803                             (void***)&session->cmds,
2804                             cmd_task_size + sizeof(struct iscsi_task)))
2805                 goto cmdpool_alloc_fail;
2806
2807         /* pre-format cmds pool with ITT */
2808         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
2809                 struct iscsi_task *task = session->cmds[cmd_i];
2810
2811                 if (cmd_task_size)
2812                         task->dd_data = &task[1];
2813                 task->itt = cmd_i;
2814                 task->state = ISCSI_TASK_FREE;
2815                 INIT_LIST_HEAD(&task->running);
2816         }
2817
2818         if (!try_module_get(iscsit->owner))
2819                 goto module_get_fail;
2820
2821         if (iscsi_add_session(cls_session, id))
2822                 goto cls_session_fail;
2823
2824         return cls_session;
2825
2826 cls_session_fail:
2827         module_put(iscsit->owner);
2828 module_get_fail:
2829         iscsi_pool_free(&session->cmdpool);
2830 cmdpool_alloc_fail:
2831         iscsi_free_session(cls_session);
2832 dec_session_count:
2833         iscsi_host_dec_session_cnt(shost);
2834         return NULL;
2835 }
2836 EXPORT_SYMBOL_GPL(iscsi_session_setup);
2837
2838 /**
2839  * iscsi_session_teardown - destroy session, host, and cls_session
2840  * @cls_session: iscsi session
2841  *
2842  * The driver must have called iscsi_remove_session before
2843  * calling this.
2844  */
2845 void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
2846 {
2847         struct iscsi_session *session = cls_session->dd_data;
2848         struct module *owner = cls_session->transport->owner;
2849         struct Scsi_Host *shost = session->host;
2850
2851         iscsi_pool_free(&session->cmdpool);
2852
2853         kfree(session->password);
2854         kfree(session->password_in);
2855         kfree(session->username);
2856         kfree(session->username_in);
2857         kfree(session->targetname);
2858         kfree(session->targetalias);
2859         kfree(session->initiatorname);
2860         kfree(session->boot_root);
2861         kfree(session->boot_nic);
2862         kfree(session->boot_target);
2863         kfree(session->ifacename);
2864         kfree(session->portal_type);
2865         kfree(session->discovery_parent_type);
2866
2867         iscsi_destroy_session(cls_session);
2868         iscsi_host_dec_session_cnt(shost);
2869         module_put(owner);
2870 }
2871 EXPORT_SYMBOL_GPL(iscsi_session_teardown);
2872
2873 /**
2874  * iscsi_conn_setup - create iscsi_cls_conn and iscsi_conn
2875  * @cls_session: iscsi_cls_session
2876  * @dd_size: private driver data size
2877  * @conn_idx: cid
2878  */
2879 struct iscsi_cls_conn *
2880 iscsi_conn_setup(struct iscsi_cls_session *cls_session, int dd_size,
2881                  uint32_t conn_idx)
2882 {
2883         struct iscsi_session *session = cls_session->dd_data;
2884         struct iscsi_conn *conn;
2885         struct iscsi_cls_conn *cls_conn;
2886         char *data;
2887
2888         cls_conn = iscsi_create_conn(cls_session, sizeof(*conn) + dd_size,
2889                                      conn_idx);
2890         if (!cls_conn)
2891                 return NULL;
2892         conn = cls_conn->dd_data;
2893         memset(conn, 0, sizeof(*conn) + dd_size);
2894
2895         conn->dd_data = cls_conn->dd_data + sizeof(*conn);
2896         conn->session = session;
2897         conn->cls_conn = cls_conn;
2898         conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
2899         conn->id = conn_idx;
2900         conn->exp_statsn = 0;
2901         conn->tmf_state = TMF_INITIAL;
2902
2903         init_timer(&conn->transport_timer);
2904         conn->transport_timer.data = (unsigned long)conn;
2905         conn->transport_timer.function = iscsi_check_transport_timeouts;
2906
2907         INIT_LIST_HEAD(&conn->mgmtqueue);
2908         INIT_LIST_HEAD(&conn->cmdqueue);
2909         INIT_LIST_HEAD(&conn->requeue);
2910         INIT_WORK(&conn->xmitwork, iscsi_xmitworker);
2911
2912         /* allocate login_task used for the login/text sequences */
2913         spin_lock_bh(&session->frwd_lock);
2914         if (!kfifo_out(&session->cmdpool.queue,
2915                          (void*)&conn->login_task,
2916                          sizeof(void*))) {
2917                 spin_unlock_bh(&session->frwd_lock);
2918                 goto login_task_alloc_fail;
2919         }
2920         spin_unlock_bh(&session->frwd_lock);
2921
2922         data = (char *) __get_free_pages(GFP_KERNEL,
2923                                          get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
2924         if (!data)
2925                 goto login_task_data_alloc_fail;
2926         conn->login_task->data = conn->data = data;
2927
2928         init_timer(&conn->tmf_timer);
2929         init_waitqueue_head(&conn->ehwait);
2930
2931         return cls_conn;
2932
2933 login_task_data_alloc_fail:
2934         kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
2935                     sizeof(void*));
2936 login_task_alloc_fail:
2937         iscsi_destroy_conn(cls_conn);
2938         return NULL;
2939 }
2940 EXPORT_SYMBOL_GPL(iscsi_conn_setup);
2941
2942 /**
2943  * iscsi_conn_teardown - teardown iscsi connection
2944  * cls_conn: iscsi class connection
2945  *
2946  * TODO: we may need to make this into a two step process
2947  * like scsi-mls remove + put host
2948  */
2949 void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
2950 {
2951         struct iscsi_conn *conn = cls_conn->dd_data;
2952         struct iscsi_session *session = conn->session;
2953         unsigned long flags;
2954
2955         del_timer_sync(&conn->transport_timer);
2956
2957         spin_lock_bh(&session->frwd_lock);
2958         conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
2959         if (session->leadconn == conn) {
2960                 /*
2961                  * leading connection? then give up on recovery.
2962                  */
2963                 session->state = ISCSI_STATE_TERMINATE;
2964                 wake_up(&conn->ehwait);
2965         }
2966         spin_unlock_bh(&session->frwd_lock);
2967
2968         /*
2969          * Block until all in-progress commands for this connection
2970          * time out or fail.
2971          */
2972         for (;;) {
2973                 spin_lock_irqsave(session->host->host_lock, flags);
2974                 if (!atomic_read(&session->host->host_busy)) { /* OK for ERL == 0 */
2975                         spin_unlock_irqrestore(session->host->host_lock, flags);
2976                         break;
2977                 }
2978                 spin_unlock_irqrestore(session->host->host_lock, flags);
2979                 msleep_interruptible(500);
2980                 iscsi_conn_printk(KERN_INFO, conn, "iscsi conn_destroy(): "
2981                                   "host_busy %d host_failed %d\n",
2982                                   atomic_read(&session->host->host_busy),
2983                                   session->host->host_failed);
2984                 /*
2985                  * force eh_abort() to unblock
2986                  */
2987                 wake_up(&conn->ehwait);
2988         }
2989
2990         /* flush queued up work because we free the connection below */
2991         iscsi_suspend_tx(conn);
2992
2993         spin_lock_bh(&session->frwd_lock);
2994         free_pages((unsigned long) conn->data,
2995                    get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
2996         kfree(conn->persistent_address);
2997         kfree(conn->local_ipaddr);
2998         /* regular RX path uses back_lock */
2999         spin_lock_bh(&session->back_lock);
3000         kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
3001                     sizeof(void*));
3002         spin_unlock_bh(&session->back_lock);
3003         if (session->leadconn == conn)
3004                 session->leadconn = NULL;
3005         spin_unlock_bh(&session->frwd_lock);
3006
3007         iscsi_destroy_conn(cls_conn);
3008 }
3009 EXPORT_SYMBOL_GPL(iscsi_conn_teardown);
3010
3011 int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
3012 {
3013         struct iscsi_conn *conn = cls_conn->dd_data;
3014         struct iscsi_session *session = conn->session;
3015
3016         if (!session) {
3017                 iscsi_conn_printk(KERN_ERR, conn,
3018                                   "can't start unbound connection\n");
3019                 return -EPERM;
3020         }
3021
3022         if ((session->imm_data_en || !session->initial_r2t_en) &&
3023              session->first_burst > session->max_burst) {
3024                 iscsi_conn_printk(KERN_INFO, conn, "invalid burst lengths: "
3025                                   "first_burst %d max_burst %d\n",
3026                                   session->first_burst, session->max_burst);
3027                 return -EINVAL;
3028         }
3029
3030         if (conn->ping_timeout && !conn->recv_timeout) {
3031                 iscsi_conn_printk(KERN_ERR, conn, "invalid recv timeout of "
3032                                   "zero. Using 5 seconds\n.");
3033                 conn->recv_timeout = 5;
3034         }
3035
3036         if (conn->recv_timeout && !conn->ping_timeout) {
3037                 iscsi_conn_printk(KERN_ERR, conn, "invalid ping timeout of "
3038                                   "zero. Using 5 seconds.\n");
3039                 conn->ping_timeout = 5;
3040         }
3041
3042         spin_lock_bh(&session->frwd_lock);
3043         conn->c_stage = ISCSI_CONN_STARTED;
3044         session->state = ISCSI_STATE_LOGGED_IN;
3045         session->queued_cmdsn = session->cmdsn;
3046
3047         conn->last_recv = jiffies;
3048         conn->last_ping = jiffies;
3049         if (conn->recv_timeout && conn->ping_timeout)
3050                 mod_timer(&conn->transport_timer,
3051                           jiffies + (conn->recv_timeout * HZ));
3052
3053         switch(conn->stop_stage) {
3054         case STOP_CONN_RECOVER:
3055                 /*
3056                  * unblock eh_abort() if it is blocked. re-try all
3057                  * commands after successful recovery
3058                  */
3059                 conn->stop_stage = 0;
3060                 conn->tmf_state = TMF_INITIAL;
3061                 session->age++;
3062                 if (session->age == 16)
3063                         session->age = 0;
3064                 break;
3065         case STOP_CONN_TERM:
3066                 conn->stop_stage = 0;
3067                 break;
3068         default:
3069                 break;
3070         }
3071         spin_unlock_bh(&session->frwd_lock);
3072
3073         iscsi_unblock_session(session->cls_session);
3074         wake_up(&conn->ehwait);
3075         return 0;
3076 }
3077 EXPORT_SYMBOL_GPL(iscsi_conn_start);
3078
3079 static void
3080 fail_mgmt_tasks(struct iscsi_session *session, struct iscsi_conn *conn)
3081 {
3082         struct iscsi_task *task;
3083         int i, state;
3084
3085         for (i = 0; i < conn->session->cmds_max; i++) {
3086                 task = conn->session->cmds[i];
3087                 if (task->sc)
3088                         continue;
3089
3090                 if (task->state == ISCSI_TASK_FREE)
3091                         continue;
3092
3093                 ISCSI_DBG_SESSION(conn->session,
3094                                   "failing mgmt itt 0x%x state %d\n",
3095                                   task->itt, task->state);
3096                 state = ISCSI_TASK_ABRT_SESS_RECOV;
3097                 if (task->state == ISCSI_TASK_PENDING)
3098                         state = ISCSI_TASK_COMPLETED;
3099                 iscsi_complete_task(task, state);
3100
3101         }
3102 }
3103
3104 static void iscsi_start_session_recovery(struct iscsi_session *session,
3105                                          struct iscsi_conn *conn, int flag)
3106 {
3107         int old_stop_stage;
3108
3109         mutex_lock(&session->eh_mutex);
3110         spin_lock_bh(&session->frwd_lock);
3111         if (conn->stop_stage == STOP_CONN_TERM) {
3112                 spin_unlock_bh(&session->frwd_lock);
3113                 mutex_unlock(&session->eh_mutex);
3114                 return;
3115         }
3116
3117         /*
3118          * When this is called for the in_login state, we only want to clean
3119          * up the login task and connection. We do not need to block and set
3120          * the recovery state again
3121          */
3122         if (flag == STOP_CONN_TERM)
3123                 session->state = ISCSI_STATE_TERMINATE;
3124         else if (conn->stop_stage != STOP_CONN_RECOVER)
3125                 session->state = ISCSI_STATE_IN_RECOVERY;
3126
3127         old_stop_stage = conn->stop_stage;
3128         conn->stop_stage = flag;
3129         spin_unlock_bh(&session->frwd_lock);
3130
3131         del_timer_sync(&conn->transport_timer);
3132         iscsi_suspend_tx(conn);
3133
3134         spin_lock_bh(&session->frwd_lock);
3135         conn->c_stage = ISCSI_CONN_STOPPED;
3136         spin_unlock_bh(&session->frwd_lock);
3137
3138         /*
3139          * for connection level recovery we should not calculate
3140          * header digest. conn->hdr_size used for optimization
3141          * in hdr_extract() and will be re-negotiated at
3142          * set_param() time.
3143          */
3144         if (flag == STOP_CONN_RECOVER) {
3145                 conn->hdrdgst_en = 0;
3146                 conn->datadgst_en = 0;
3147                 if (session->state == ISCSI_STATE_IN_RECOVERY &&
3148                     old_stop_stage != STOP_CONN_RECOVER) {
3149                         ISCSI_DBG_SESSION(session, "blocking session\n");
3150                         iscsi_block_session(session->cls_session);
3151                 }
3152         }
3153
3154         /*
3155          * flush queues.
3156          */
3157         spin_lock_bh(&session->frwd_lock);
3158         fail_scsi_tasks(conn, -1, DID_TRANSPORT_DISRUPTED);
3159         fail_mgmt_tasks(session, conn);
3160         memset(&conn->tmhdr, 0, sizeof(conn->tmhdr));
3161         spin_unlock_bh(&session->frwd_lock);
3162         mutex_unlock(&session->eh_mutex);
3163 }
3164
3165 void iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
3166 {
3167         struct iscsi_conn *conn = cls_conn->dd_data;
3168         struct iscsi_session *session = conn->session;
3169
3170         switch (flag) {
3171         case STOP_CONN_RECOVER:
3172         case STOP_CONN_TERM:
3173                 iscsi_start_session_recovery(session, conn, flag);
3174                 break;
3175         default:
3176                 iscsi_conn_printk(KERN_ERR, conn,
3177                                   "invalid stop flag %d\n", flag);
3178         }
3179 }
3180 EXPORT_SYMBOL_GPL(iscsi_conn_stop);
3181
3182 int iscsi_conn_bind(struct iscsi_cls_session *cls_session,
3183                     struct iscsi_cls_conn *cls_conn, int is_leading)
3184 {
3185         struct iscsi_session *session = cls_session->dd_data;
3186         struct iscsi_conn *conn = cls_conn->dd_data;
3187
3188         spin_lock_bh(&session->frwd_lock);
3189         if (is_leading)
3190                 session->leadconn = conn;
3191         spin_unlock_bh(&session->frwd_lock);
3192
3193         /*
3194          * Unblock xmitworker(), Login Phase will pass through.
3195          */
3196         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
3197         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
3198         return 0;
3199 }
3200 EXPORT_SYMBOL_GPL(iscsi_conn_bind);
3201
3202 int iscsi_switch_str_param(char **param, char *new_val_buf)
3203 {
3204         char *new_val;
3205
3206         if (*param) {
3207                 if (!strcmp(*param, new_val_buf))
3208                         return 0;
3209         }
3210
3211         new_val = kstrdup(new_val_buf, GFP_NOIO);
3212         if (!new_val)
3213                 return -ENOMEM;
3214
3215         kfree(*param);
3216         *param = new_val;
3217         return 0;
3218 }
3219 EXPORT_SYMBOL_GPL(iscsi_switch_str_param);
3220
3221 int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
3222                     enum iscsi_param param, char *buf, int buflen)
3223 {
3224         struct iscsi_conn *conn = cls_conn->dd_data;
3225         struct iscsi_session *session = conn->session;
3226         int val;
3227
3228         switch(param) {
3229         case ISCSI_PARAM_FAST_ABORT:
3230                 sscanf(buf, "%d", &session->fast_abort);
3231                 break;
3232         case ISCSI_PARAM_ABORT_TMO:
3233                 sscanf(buf, "%d", &session->abort_timeout);
3234                 break;
3235         case ISCSI_PARAM_LU_RESET_TMO:
3236                 sscanf(buf, "%d", &session->lu_reset_timeout);
3237                 break;
3238         case ISCSI_PARAM_TGT_RESET_TMO:
3239                 sscanf(buf, "%d", &session->tgt_reset_timeout);
3240                 break;
3241         case ISCSI_PARAM_PING_TMO:
3242                 sscanf(buf, "%d", &conn->ping_timeout);
3243                 break;
3244         case ISCSI_PARAM_RECV_TMO:
3245                 sscanf(buf, "%d", &conn->recv_timeout);
3246                 break;
3247         case ISCSI_PARAM_MAX_RECV_DLENGTH:
3248                 sscanf(buf, "%d", &conn->max_recv_dlength);
3249                 break;
3250         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3251                 sscanf(buf, "%d", &conn->max_xmit_dlength);
3252                 break;
3253         case ISCSI_PARAM_HDRDGST_EN:
3254                 sscanf(buf, "%d", &conn->hdrdgst_en);
3255                 break;
3256         case ISCSI_PARAM_DATADGST_EN:
3257                 sscanf(buf, "%d", &conn->datadgst_en);
3258                 break;
3259         case ISCSI_PARAM_INITIAL_R2T_EN:
3260                 sscanf(buf, "%d", &session->initial_r2t_en);
3261                 break;
3262         case ISCSI_PARAM_MAX_R2T:
3263                 sscanf(buf, "%hu", &session->max_r2t);
3264                 break;
3265         case ISCSI_PARAM_IMM_DATA_EN:
3266                 sscanf(buf, "%d", &session->imm_data_en);
3267                 break;
3268         case ISCSI_PARAM_FIRST_BURST:
3269                 sscanf(buf, "%d", &session->first_burst);
3270                 break;
3271         case ISCSI_PARAM_MAX_BURST:
3272                 sscanf(buf, "%d", &session->max_burst);
3273                 break;
3274         case ISCSI_PARAM_PDU_INORDER_EN:
3275                 sscanf(buf, "%d", &session->pdu_inorder_en);
3276                 break;
3277         case ISCSI_PARAM_DATASEQ_INORDER_EN:
3278                 sscanf(buf, "%d", &session->dataseq_inorder_en);
3279                 break;
3280         case ISCSI_PARAM_ERL:
3281                 sscanf(buf, "%d", &session->erl);
3282                 break;
3283         case ISCSI_PARAM_EXP_STATSN:
3284                 sscanf(buf, "%u", &conn->exp_statsn);
3285                 break;
3286         case ISCSI_PARAM_USERNAME:
3287                 return iscsi_switch_str_param(&session->username, buf);
3288         case ISCSI_PARAM_USERNAME_IN:
3289                 return iscsi_switch_str_param(&session->username_in, buf);
3290         case ISCSI_PARAM_PASSWORD:
3291                 return iscsi_switch_str_param(&session->password, buf);
3292         case ISCSI_PARAM_PASSWORD_IN:
3293                 return iscsi_switch_str_param(&session->password_in, buf);
3294         case ISCSI_PARAM_TARGET_NAME:
3295                 return iscsi_switch_str_param(&session->targetname, buf);
3296         case ISCSI_PARAM_TARGET_ALIAS:
3297                 return iscsi_switch_str_param(&session->targetalias, buf);
3298         case ISCSI_PARAM_TPGT:
3299                 sscanf(buf, "%d", &session->tpgt);
3300                 break;
3301         case ISCSI_PARAM_PERSISTENT_PORT:
3302                 sscanf(buf, "%d", &conn->persistent_port);
3303                 break;
3304         case ISCSI_PARAM_PERSISTENT_ADDRESS:
3305                 return iscsi_switch_str_param(&conn->persistent_address, buf);
3306         case ISCSI_PARAM_IFACE_NAME:
3307                 return iscsi_switch_str_param(&session->ifacename, buf);
3308         case ISCSI_PARAM_INITIATOR_NAME:
3309                 return iscsi_switch_str_param(&session->initiatorname, buf);
3310         case ISCSI_PARAM_BOOT_ROOT:
3311                 return iscsi_switch_str_param(&session->boot_root, buf);
3312         case ISCSI_PARAM_BOOT_NIC:
3313                 return iscsi_switch_str_param(&session->boot_nic, buf);
3314         case ISCSI_PARAM_BOOT_TARGET:
3315                 return iscsi_switch_str_param(&session->boot_target, buf);
3316         case ISCSI_PARAM_PORTAL_TYPE:
3317                 return iscsi_switch_str_param(&session->portal_type, buf);
3318         case ISCSI_PARAM_DISCOVERY_PARENT_TYPE:
3319                 return iscsi_switch_str_param(&session->discovery_parent_type,
3320                                               buf);
3321         case ISCSI_PARAM_DISCOVERY_SESS:
3322                 sscanf(buf, "%d", &val);
3323                 session->discovery_sess = !!val;
3324                 break;
3325         case ISCSI_PARAM_LOCAL_IPADDR:
3326                 return iscsi_switch_str_param(&conn->local_ipaddr, buf);
3327         default:
3328                 return -ENOSYS;
3329         }
3330
3331         return 0;
3332 }
3333 EXPORT_SYMBOL_GPL(iscsi_set_param);
3334
3335 int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
3336                             enum iscsi_param param, char *buf)
3337 {
3338         struct iscsi_session *session = cls_session->dd_data;
3339         int len;
3340
3341         switch(param) {
3342         case ISCSI_PARAM_FAST_ABORT:
3343                 len = sprintf(buf, "%d\n", session->fast_abort);
3344                 break;
3345         case ISCSI_PARAM_ABORT_TMO:
3346                 len = sprintf(buf, "%d\n", session->abort_timeout);
3347                 break;
3348         case ISCSI_PARAM_LU_RESET_TMO:
3349                 len = sprintf(buf, "%d\n", session->lu_reset_timeout);
3350                 break;
3351         case ISCSI_PARAM_TGT_RESET_TMO:
3352                 len = sprintf(buf, "%d\n", session->tgt_reset_timeout);
3353                 break;
3354         case ISCSI_PARAM_INITIAL_R2T_EN:
3355                 len = sprintf(buf, "%d\n", session->initial_r2t_en);
3356                 break;
3357         case ISCSI_PARAM_MAX_R2T:
3358                 len = sprintf(buf, "%hu\n", session->max_r2t);
3359                 break;
3360         case ISCSI_PARAM_IMM_DATA_EN:
3361                 len = sprintf(buf, "%d\n", session->imm_data_en);
3362                 break;
3363         case ISCSI_PARAM_FIRST_BURST:
3364                 len = sprintf(buf, "%u\n", session->first_burst);
3365                 break;
3366         case ISCSI_PARAM_MAX_BURST:
3367                 len = sprintf(buf, "%u\n", session->max_burst);
3368                 break;
3369         case ISCSI_PARAM_PDU_INORDER_EN:
3370                 len = sprintf(buf, "%d\n", session->pdu_inorder_en);
3371                 break;
3372         case ISCSI_PARAM_DATASEQ_INORDER_EN:
3373                 len = sprintf(buf, "%d\n", session->dataseq_inorder_en);
3374                 break;
3375         case ISCSI_PARAM_DEF_TASKMGMT_TMO:
3376                 len = sprintf(buf, "%d\n", session->def_taskmgmt_tmo);
3377                 break;
3378         case ISCSI_PARAM_ERL:
3379                 len = sprintf(buf, "%d\n", session->erl);
3380                 break;
3381         case ISCSI_PARAM_TARGET_NAME:
3382                 len = sprintf(buf, "%s\n", session->targetname);
3383                 break;
3384         case ISCSI_PARAM_TARGET_ALIAS:
3385                 len = sprintf(buf, "%s\n", session->targetalias);
3386                 break;
3387         case ISCSI_PARAM_TPGT:
3388                 len = sprintf(buf, "%d\n", session->tpgt);
3389                 break;
3390         case ISCSI_PARAM_USERNAME:
3391                 len = sprintf(buf, "%s\n", session->username);
3392                 break;
3393         case ISCSI_PARAM_USERNAME_IN:
3394                 len = sprintf(buf, "%s\n", session->username_in);
3395                 break;
3396         case ISCSI_PARAM_PASSWORD:
3397                 len = sprintf(buf, "%s\n", session->password);
3398                 break;
3399         case ISCSI_PARAM_PASSWORD_IN:
3400                 len = sprintf(buf, "%s\n", session->password_in);
3401                 break;
3402         case ISCSI_PARAM_IFACE_NAME:
3403                 len = sprintf(buf, "%s\n", session->ifacename);
3404                 break;
3405         case ISCSI_PARAM_INITIATOR_NAME:
3406                 len = sprintf(buf, "%s\n", session->initiatorname);
3407                 break;
3408         case ISCSI_PARAM_BOOT_ROOT:
3409                 len = sprintf(buf, "%s\n", session->boot_root);
3410                 break;
3411         case ISCSI_PARAM_BOOT_NIC:
3412                 len = sprintf(buf, "%s\n", session->boot_nic);
3413                 break;
3414         case ISCSI_PARAM_BOOT_TARGET:
3415                 len = sprintf(buf, "%s\n", session->boot_target);
3416                 break;
3417         case ISCSI_PARAM_AUTO_SND_TGT_DISABLE:
3418                 len = sprintf(buf, "%u\n", session->auto_snd_tgt_disable);
3419                 break;
3420         case ISCSI_PARAM_DISCOVERY_SESS:
3421                 len = sprintf(buf, "%u\n", session->discovery_sess);
3422                 break;
3423         case ISCSI_PARAM_PORTAL_TYPE:
3424                 len = sprintf(buf, "%s\n", session->portal_type);
3425                 break;
3426         case ISCSI_PARAM_CHAP_AUTH_EN:
3427                 len = sprintf(buf, "%u\n", session->chap_auth_en);
3428                 break;
3429         case ISCSI_PARAM_DISCOVERY_LOGOUT_EN:
3430                 len = sprintf(buf, "%u\n", session->discovery_logout_en);
3431                 break;
3432         case ISCSI_PARAM_BIDI_CHAP_EN:
3433                 len = sprintf(buf, "%u\n", session->bidi_chap_en);
3434                 break;
3435         case ISCSI_PARAM_DISCOVERY_AUTH_OPTIONAL:
3436                 len = sprintf(buf, "%u\n", session->discovery_auth_optional);
3437                 break;
3438         case ISCSI_PARAM_DEF_TIME2WAIT:
3439                 len = sprintf(buf, "%d\n", session->time2wait);
3440                 break;
3441         case ISCSI_PARAM_DEF_TIME2RETAIN:
3442                 len = sprintf(buf, "%d\n", session->time2retain);
3443                 break;
3444         case ISCSI_PARAM_TSID:
3445                 len = sprintf(buf, "%u\n", session->tsid);
3446                 break;
3447         case ISCSI_PARAM_ISID:
3448                 len = sprintf(buf, "%02x%02x%02x%02x%02x%02x\n",
3449                               session->isid[0], session->isid[1],
3450                               session->isid[2], session->isid[3],
3451                               session->isid[4], session->isid[5]);
3452                 break;
3453         case ISCSI_PARAM_DISCOVERY_PARENT_IDX:
3454                 len = sprintf(buf, "%u\n", session->discovery_parent_idx);
3455                 break;
3456         case ISCSI_PARAM_DISCOVERY_PARENT_TYPE:
3457                 if (session->discovery_parent_type)
3458                         len = sprintf(buf, "%s\n",
3459                                       session->discovery_parent_type);
3460                 else
3461                         len = sprintf(buf, "\n");
3462                 break;
3463         default:
3464                 return -ENOSYS;
3465         }
3466
3467         return len;
3468 }
3469 EXPORT_SYMBOL_GPL(iscsi_session_get_param);
3470
3471 int iscsi_conn_get_addr_param(struct sockaddr_storage *addr,
3472                               enum iscsi_param param, char *buf)
3473 {
3474         struct sockaddr_in6 *sin6 = NULL;
3475         struct sockaddr_in *sin = NULL;
3476         int len;
3477
3478         switch (addr->ss_family) {
3479         case AF_INET:
3480                 sin = (struct sockaddr_in *)addr;
3481                 break;
3482         case AF_INET6:
3483                 sin6 = (struct sockaddr_in6 *)addr;
3484                 break;
3485         default:
3486                 return -EINVAL;
3487         }
3488
3489         switch (param) {
3490         case ISCSI_PARAM_CONN_ADDRESS:
3491         case ISCSI_HOST_PARAM_IPADDRESS:
3492                 if (sin)
3493                         len = sprintf(buf, "%pI4\n", &sin->sin_addr.s_addr);
3494                 else
3495                         len = sprintf(buf, "%pI6\n", &sin6->sin6_addr);
3496                 break;
3497         case ISCSI_PARAM_CONN_PORT:
3498                 if (sin)
3499                         len = sprintf(buf, "%hu\n", be16_to_cpu(sin->sin_port));
3500                 else
3501                         len = sprintf(buf, "%hu\n",
3502                                       be16_to_cpu(sin6->sin6_port));
3503                 break;
3504         default:
3505                 return -EINVAL;
3506         }
3507
3508         return len;
3509 }
3510 EXPORT_SYMBOL_GPL(iscsi_conn_get_addr_param);
3511
3512 int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
3513                          enum iscsi_param param, char *buf)
3514 {
3515         struct iscsi_conn *conn = cls_conn->dd_data;
3516         int len;
3517
3518         switch(param) {
3519         case ISCSI_PARAM_PING_TMO:
3520                 len = sprintf(buf, "%u\n", conn->ping_timeout);
3521                 break;
3522         case ISCSI_PARAM_RECV_TMO:
3523                 len = sprintf(buf, "%u\n", conn->recv_timeout);
3524                 break;
3525         case ISCSI_PARAM_MAX_RECV_DLENGTH:
3526                 len = sprintf(buf, "%u\n", conn->max_recv_dlength);
3527                 break;
3528         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3529                 len = sprintf(buf, "%u\n", conn->max_xmit_dlength);
3530                 break;
3531         case ISCSI_PARAM_HDRDGST_EN:
3532                 len = sprintf(buf, "%d\n", conn->hdrdgst_en);
3533                 break;
3534         case ISCSI_PARAM_DATADGST_EN:
3535                 len = sprintf(buf, "%d\n", conn->datadgst_en);
3536                 break;
3537         case ISCSI_PARAM_IFMARKER_EN:
3538                 len = sprintf(buf, "%d\n", conn->ifmarker_en);
3539                 break;
3540         case ISCSI_PARAM_OFMARKER_EN:
3541                 len = sprintf(buf, "%d\n", conn->ofmarker_en);
3542                 break;
3543         case ISCSI_PARAM_EXP_STATSN:
3544                 len = sprintf(buf, "%u\n", conn->exp_statsn);
3545                 break;
3546         case ISCSI_PARAM_PERSISTENT_PORT:
3547                 len = sprintf(buf, "%d\n", conn->persistent_port);
3548                 break;
3549         case ISCSI_PARAM_PERSISTENT_ADDRESS:
3550                 len = sprintf(buf, "%s\n", conn->persistent_address);
3551                 break;
3552         case ISCSI_PARAM_STATSN:
3553                 len = sprintf(buf, "%u\n", conn->statsn);
3554                 break;
3555         case ISCSI_PARAM_MAX_SEGMENT_SIZE:
3556                 len = sprintf(buf, "%u\n", conn->max_segment_size);
3557                 break;
3558         case ISCSI_PARAM_KEEPALIVE_TMO:
3559                 len = sprintf(buf, "%u\n", conn->keepalive_tmo);
3560                 break;
3561         case ISCSI_PARAM_LOCAL_PORT:
3562                 len = sprintf(buf, "%u\n", conn->local_port);
3563                 break;
3564         case ISCSI_PARAM_TCP_TIMESTAMP_STAT:
3565                 len = sprintf(buf, "%u\n", conn->tcp_timestamp_stat);
3566                 break;
3567         case ISCSI_PARAM_TCP_NAGLE_DISABLE:
3568                 len = sprintf(buf, "%u\n", conn->tcp_nagle_disable);
3569                 break;
3570         case ISCSI_PARAM_TCP_WSF_DISABLE:
3571                 len = sprintf(buf, "%u\n", conn->tcp_wsf_disable);
3572                 break;
3573         case ISCSI_PARAM_TCP_TIMER_SCALE:
3574                 len = sprintf(buf, "%u\n", conn->tcp_timer_scale);
3575                 break;
3576         case ISCSI_PARAM_TCP_TIMESTAMP_EN:
3577                 len = sprintf(buf, "%u\n", conn->tcp_timestamp_en);
3578                 break;
3579         case ISCSI_PARAM_IP_FRAGMENT_DISABLE:
3580                 len = sprintf(buf, "%u\n", conn->fragment_disable);
3581                 break;
3582         case ISCSI_PARAM_IPV4_TOS:
3583                 len = sprintf(buf, "%u\n", conn->ipv4_tos);
3584                 break;
3585         case ISCSI_PARAM_IPV6_TC:
3586                 len = sprintf(buf, "%u\n", conn->ipv6_traffic_class);
3587                 break;
3588         case ISCSI_PARAM_IPV6_FLOW_LABEL:
3589                 len = sprintf(buf, "%u\n", conn->ipv6_flow_label);
3590                 break;
3591         case ISCSI_PARAM_IS_FW_ASSIGNED_IPV6:
3592                 len = sprintf(buf, "%u\n", conn->is_fw_assigned_ipv6);
3593                 break;
3594         case ISCSI_PARAM_TCP_XMIT_WSF:
3595                 len = sprintf(buf, "%u\n", conn->tcp_xmit_wsf);
3596                 break;
3597         case ISCSI_PARAM_TCP_RECV_WSF:
3598                 len = sprintf(buf, "%u\n", conn->tcp_recv_wsf);
3599                 break;
3600         case ISCSI_PARAM_LOCAL_IPADDR:
3601                 len = sprintf(buf, "%s\n", conn->local_ipaddr);
3602                 break;
3603         default:
3604                 return -ENOSYS;
3605         }
3606
3607         return len;
3608 }
3609 EXPORT_SYMBOL_GPL(iscsi_conn_get_param);
3610
3611 int iscsi_host_get_param(struct Scsi_Host *shost, enum iscsi_host_param param,
3612                          char *buf)
3613 {
3614         struct iscsi_host *ihost = shost_priv(shost);
3615         int len;
3616
3617         switch (param) {
3618         case ISCSI_HOST_PARAM_NETDEV_NAME:
3619                 len = sprintf(buf, "%s\n", ihost->netdev);
3620                 break;
3621         case ISCSI_HOST_PARAM_HWADDRESS:
3622                 len = sprintf(buf, "%s\n", ihost->hwaddress);
3623                 break;
3624         case ISCSI_HOST_PARAM_INITIATOR_NAME:
3625                 len = sprintf(buf, "%s\n", ihost->initiatorname);
3626                 break;
3627         default:
3628                 return -ENOSYS;
3629         }
3630
3631         return len;
3632 }
3633 EXPORT_SYMBOL_GPL(iscsi_host_get_param);
3634
3635 int iscsi_host_set_param(struct Scsi_Host *shost, enum iscsi_host_param param,
3636                          char *buf, int buflen)
3637 {
3638         struct iscsi_host *ihost = shost_priv(shost);
3639
3640         switch (param) {
3641         case ISCSI_HOST_PARAM_NETDEV_NAME:
3642                 return iscsi_switch_str_param(&ihost->netdev, buf);
3643         case ISCSI_HOST_PARAM_HWADDRESS:
3644                 return iscsi_switch_str_param(&ihost->hwaddress, buf);
3645         case ISCSI_HOST_PARAM_INITIATOR_NAME:
3646                 return iscsi_switch_str_param(&ihost->initiatorname, buf);
3647         default:
3648                 return -ENOSYS;
3649         }
3650
3651         return 0;
3652 }
3653 EXPORT_SYMBOL_GPL(iscsi_host_set_param);
3654
3655 MODULE_AUTHOR("Mike Christie");
3656 MODULE_DESCRIPTION("iSCSI library functions");
3657 MODULE_LICENSE("GPL");