drivers/scsi/libiscsi.c

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