drivers/scsi/libiscsi.c

   1 /*
   2  * iSCSI lib functions
   3  *
   4  * Copyright (C) 2006 Red Hat, Inc.  All rights reserved.
   5  * Copyright (C) 2004 - 2006 Mike Christie
   6  * Copyright (C) 2004 - 2005 Dmitry Yusupov
   7  * Copyright (C) 2004 - 2005 Alex Aizman
   8  * maintained by open-iscsi@googlegroups.com
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  23  */
  24 #include <linux/types.h>
  25 #include <linux/kfifo.h>
  26 #include <linux/delay.h>
  27 #include <linux/log2.h>
  28 #include <linux/slab.h>
  29 #include <linux/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         spin_lock_bh(&conn->taskqueuelock);
 565         if (!list_empty(&task->running)) {
 566                 pr_debug_once("%s while task on list", __func__);
 567                 list_del_init(&task->running);
 568         }
 569         spin_unlock_bh(&conn->taskqueuelock);
 570
 571         if (conn->task == task)
 572                 conn->task = NULL;
 573
 574         if (conn->ping_task == task)
 575                 conn->ping_task = NULL;
 576
 577         /* release get from queueing */
 578         __iscsi_put_task(task);
 579 }
 580
 581 /**
 582  * iscsi_complete_scsi_task - finish scsi task normally
 583  * @task: iscsi task for scsi cmd
 584  * @exp_cmdsn: expected cmd sn in cpu format
 585  * @max_cmdsn: max cmd sn in cpu format
 586  *
 587  * This is used when drivers do not need or cannot perform
 588  * lower level pdu processing.
 589  *
 590  * Called with session back_lock
 591  */
 592 void iscsi_complete_scsi_task(struct iscsi_task *task,
 593                               uint32_t exp_cmdsn, uint32_t max_cmdsn)
 594 {
 595         struct iscsi_conn *conn = task->conn;
 596
 597         ISCSI_DBG_SESSION(conn->session, "[itt 0x%x]\n", task->itt);
 598
 599         conn->last_recv = jiffies;
 600         __iscsi_update_cmdsn(conn->session, exp_cmdsn, max_cmdsn);
 601         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 602 }
 603 EXPORT_SYMBOL_GPL(iscsi_complete_scsi_task);
 604
 605
 606 /*
 607  * session back_lock must be held and if not called for a task that is
 608  * still pending or from the xmit thread, then xmit thread must
 609  * be suspended.
 610  */
 611 static void fail_scsi_task(struct iscsi_task *task, int err)
 612 {
 613         struct iscsi_conn *conn = task->conn;
 614         struct scsi_cmnd *sc;
 615         int state;
 616
 617         /*
 618          * if a command completes and we get a successful tmf response
 619          * we will hit this because the scsi eh abort code does not take
 620          * a ref to the task.
 621          */
 622         sc = task->sc;
 623         if (!sc)
 624                 return;
 625
 626         if (task->state == ISCSI_TASK_PENDING) {
 627                 /*
 628                  * cmd never made it to the xmit thread, so we should not count
 629                  * the cmd in the sequencing
 630                  */
 631                 conn->session->queued_cmdsn--;
 632                 /* it was never sent so just complete like normal */
 633                 state = ISCSI_TASK_COMPLETED;
 634         } else if (err == DID_TRANSPORT_DISRUPTED)
 635                 state = ISCSI_TASK_ABRT_SESS_RECOV;
 636         else
 637                 state = ISCSI_TASK_ABRT_TMF;
 638
 639         sc->result = err << 16;
 640         if (!scsi_bidi_cmnd(sc))
 641                 scsi_set_resid(sc, scsi_bufflen(sc));
 642         else {
 643                 scsi_out(sc)->resid = scsi_out(sc)->length;
 644                 scsi_in(sc)->resid = scsi_in(sc)->length;
 645         }
 646
 647         /* regular RX path uses back_lock */
 648         spin_lock_bh(&conn->session->back_lock);
 649         iscsi_complete_task(task, state);
 650         spin_unlock_bh(&conn->session->back_lock);
 651 }
 652
 653 static int iscsi_prep_mgmt_task(struct iscsi_conn *conn,
 654                                 struct iscsi_task *task)
 655 {
 656         struct iscsi_session *session = conn->session;
 657         struct iscsi_hdr *hdr = task->hdr;
 658         struct iscsi_nopout *nop = (struct iscsi_nopout *)hdr;
 659         uint8_t opcode = hdr->opcode & ISCSI_OPCODE_MASK;
 660
 661         if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
 662                 return -ENOTCONN;
 663
 664         if (opcode != ISCSI_OP_LOGIN && opcode != ISCSI_OP_TEXT)
 665                 nop->exp_statsn = cpu_to_be32(conn->exp_statsn);
 666         /*
 667          * pre-format CmdSN for outgoing PDU.
 668          */
 669         nop->cmdsn = cpu_to_be32(session->cmdsn);
 670         if (hdr->itt != RESERVED_ITT) {
 671                 /*
 672                  * TODO: We always use immediate for normal session pdus.
 673                  * If we start to send tmfs or nops as non-immediate then
 674                  * we should start checking the cmdsn numbers for mgmt tasks.
 675                  *
 676                  * During discovery sessions iscsid sends TEXT as non immediate,
 677                  * but we always only send one PDU at a time.
 678                  */
 679                 if (conn->c_stage == ISCSI_CONN_STARTED &&
 680                     !(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
 681                         session->queued_cmdsn++;
 682                         session->cmdsn++;
 683                 }
 684         }
 685
 686         if (session->tt->init_task && session->tt->init_task(task))
 687                 return -EIO;
 688
 689         if ((hdr->opcode & ISCSI_OPCODE_MASK) == ISCSI_OP_LOGOUT)
 690                 session->state = ISCSI_STATE_LOGGING_OUT;
 691
 692         task->state = ISCSI_TASK_RUNNING;
 693         ISCSI_DBG_SESSION(session, "mgmtpdu [op 0x%x hdr->itt 0x%x "
 694                           "datalen %d]\n", hdr->opcode & ISCSI_OPCODE_MASK,
 695                           hdr->itt, task->data_count);
 696         return 0;
 697 }
 698
 699 static struct iscsi_task *
 700 __iscsi_conn_send_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 701                       char *data, uint32_t data_size)
 702 {
 703         struct iscsi_session *session = conn->session;
 704         struct iscsi_host *ihost = shost_priv(session->host);
 705         uint8_t opcode = hdr->opcode & ISCSI_OPCODE_MASK;
 706         struct iscsi_task *task;
 707         itt_t itt;
 708
 709         if (session->state == ISCSI_STATE_TERMINATE)
 710                 return NULL;
 711
 712         if (opcode == ISCSI_OP_LOGIN || opcode == ISCSI_OP_TEXT) {
 713                 /*
 714                  * Login and Text are sent serially, in
 715                  * request-followed-by-response sequence.
 716                  * Same task can be used. Same ITT must be used.
 717                  * Note that login_task is preallocated at conn_create().
 718                  */
 719                 if (conn->login_task->state != ISCSI_TASK_FREE) {
 720                         iscsi_conn_printk(KERN_ERR, conn, "Login/Text in "
 721                                           "progress. Cannot start new task.\n");
 722                         return NULL;
 723                 }
 724
 725                 if (data_size > ISCSI_DEF_MAX_RECV_SEG_LEN) {
 726                         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);
 727                         return NULL;
 728                 }
 729
 730                 task = conn->login_task;
 731         } else {
 732                 if (session->state != ISCSI_STATE_LOGGED_IN)
 733                         return NULL;
 734
 735                 if (data_size != 0) {
 736                         iscsi_conn_printk(KERN_ERR, conn, "Can not send data buffer of len %u for op 0x%x\n", data_size, opcode);
 737                         return NULL;
 738                 }
 739
 740                 BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
 741                 BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);
 742
 743                 if (!kfifo_out(&session->cmdpool.queue,
 744                                  (void*)&task, sizeof(void*)))
 745                         return NULL;
 746         }
 747         /*
 748          * released in complete pdu for task we expect a response for, and
 749          * released by the lld when it has transmitted the task for
 750          * pdus we do not expect a response for.
 751          */
 752         refcount_set(&task->refcount, 1);
 753         task->conn = conn;
 754         task->sc = NULL;
 755         INIT_LIST_HEAD(&task->running);
 756         task->state = ISCSI_TASK_PENDING;
 757
 758         if (data_size) {
 759                 memcpy(task->data, data, data_size);
 760                 task->data_count = data_size;
 761         } else
 762                 task->data_count = 0;
 763
 764         if (conn->session->tt->alloc_pdu) {
 765                 if (conn->session->tt->alloc_pdu(task, hdr->opcode)) {
 766                         iscsi_conn_printk(KERN_ERR, conn, "Could not allocate "
 767                                          "pdu for mgmt task.\n");
 768                         goto free_task;
 769                 }
 770         }
 771
 772         itt = task->hdr->itt;
 773         task->hdr_len = sizeof(struct iscsi_hdr);
 774         memcpy(task->hdr, hdr, sizeof(struct iscsi_hdr));
 775
 776         if (hdr->itt != RESERVED_ITT) {
 777                 if (session->tt->parse_pdu_itt)
 778                         task->hdr->itt = itt;
 779                 else
 780                         task->hdr->itt = build_itt(task->itt,
 781                                                    task->conn->session->age);
 782         }
 783
 784         if (!ihost->workq) {
 785                 if (iscsi_prep_mgmt_task(conn, task))
 786                         goto free_task;
 787
 788                 if (session->tt->xmit_task(task))
 789                         goto free_task;
 790         } else {
 791                 spin_lock_bh(&conn->taskqueuelock);
 792                 list_add_tail(&task->running, &conn->mgmtqueue);
 793                 spin_unlock_bh(&conn->taskqueuelock);
 794                 iscsi_conn_queue_work(conn);
 795         }
 796
 797         return task;
 798
 799 free_task:
 800         /* regular RX path uses back_lock */
 801         spin_lock(&session->back_lock);
 802         __iscsi_put_task(task);
 803         spin_unlock(&session->back_lock);
 804         return NULL;
 805 }
 806
 807 int iscsi_conn_send_pdu(struct iscsi_cls_conn *cls_conn, struct iscsi_hdr *hdr,
 808                         char *data, uint32_t data_size)
 809 {
 810         struct iscsi_conn *conn = cls_conn->dd_data;
 811         struct iscsi_session *session = conn->session;
 812         int err = 0;
 813
 814         spin_lock_bh(&session->frwd_lock);
 815         if (!__iscsi_conn_send_pdu(conn, hdr, data, data_size))
 816                 err = -EPERM;
 817         spin_unlock_bh(&session->frwd_lock);
 818         return err;
 819 }
 820 EXPORT_SYMBOL_GPL(iscsi_conn_send_pdu);
 821
 822 /**
 823  * iscsi_cmd_rsp - SCSI Command Response processing
 824  * @conn: iscsi connection
 825  * @hdr: iscsi header
 826  * @task: scsi command task
 827  * @data: cmd data buffer
 828  * @datalen: len of buffer
 829  *
 830  * iscsi_cmd_rsp sets up the scsi_cmnd fields based on the PDU and
 831  * then completes the command and task.
 832  **/
 833 static void iscsi_scsi_cmd_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 834                                struct iscsi_task *task, char *data,
 835                                int datalen)
 836 {
 837         struct iscsi_scsi_rsp *rhdr = (struct iscsi_scsi_rsp *)hdr;
 838         struct iscsi_session *session = conn->session;
 839         struct scsi_cmnd *sc = task->sc;
 840
 841         iscsi_update_cmdsn(session, (struct iscsi_nopin*)rhdr);
 842         conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 843
 844         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 845
 846         if (task->protected) {
 847                 sector_t sector;
 848                 u8 ascq;
 849
 850                 /**
 851                  * Transports that didn't implement check_protection
 852                  * callback but still published T10-PI support to scsi-mid
 853                  * deserve this BUG_ON.
 854                  **/
 855                 BUG_ON(!session->tt->check_protection);
 856
 857                 ascq = session->tt->check_protection(task, &sector);
 858                 if (ascq) {
 859                         sc->result = DRIVER_SENSE << 24 |
 860                                      SAM_STAT_CHECK_CONDITION;
 861                         scsi_build_sense_buffer(1, sc->sense_buffer,
 862                                                 ILLEGAL_REQUEST, 0x10, ascq);
 863                         scsi_set_sense_information(sc->sense_buffer,
 864                                                    SCSI_SENSE_BUFFERSIZE,
 865                                                    sector);
 866                         goto out;
 867                 }
 868         }
 869
 870         if (rhdr->response != ISCSI_STATUS_CMD_COMPLETED) {
 871                 sc->result = DID_ERROR << 16;
 872                 goto out;
 873         }
 874
 875         if (rhdr->cmd_status == SAM_STAT_CHECK_CONDITION) {
 876                 uint16_t senselen;
 877
 878                 if (datalen < 2) {
 879 invalid_datalen:
 880                         iscsi_conn_printk(KERN_ERR,  conn,
 881                                          "Got CHECK_CONDITION but invalid data "
 882                                          "buffer size of %d\n", datalen);
 883                         sc->result = DID_BAD_TARGET << 16;
 884                         goto out;
 885                 }
 886
 887                 senselen = get_unaligned_be16(data);
 888                 if (datalen < senselen)
 889                         goto invalid_datalen;
 890
 891                 memcpy(sc->sense_buffer, data + 2,
 892                        min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
 893                 ISCSI_DBG_SESSION(session, "copied %d bytes of sense\n",
 894                                   min_t(uint16_t, senselen,
 895                                   SCSI_SENSE_BUFFERSIZE));
 896         }
 897
 898         if (rhdr->flags & (ISCSI_FLAG_CMD_BIDI_UNDERFLOW |
 899                            ISCSI_FLAG_CMD_BIDI_OVERFLOW)) {
 900                 int res_count = be32_to_cpu(rhdr->bi_residual_count);
 901
 902                 if (scsi_bidi_cmnd(sc) && res_count > 0 &&
 903                                 (rhdr->flags & ISCSI_FLAG_CMD_BIDI_OVERFLOW ||
 904                                  res_count <= scsi_in(sc)->length))
 905                         scsi_in(sc)->resid = res_count;
 906                 else
 907                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 908         }
 909
 910         if (rhdr->flags & (ISCSI_FLAG_CMD_UNDERFLOW |
 911                            ISCSI_FLAG_CMD_OVERFLOW)) {
 912                 int res_count = be32_to_cpu(rhdr->residual_count);
 913
 914                 if (res_count > 0 &&
 915                     (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
 916                      res_count <= scsi_bufflen(sc)))
 917                         /* write side for bidi or uni-io set_resid */
 918                         scsi_set_resid(sc, res_count);
 919                 else
 920                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 921         }
 922 out:
 923         ISCSI_DBG_SESSION(session, "cmd rsp done [sc %p res %d itt 0x%x]\n",
 924                           sc, sc->result, task->itt);
 925         conn->scsirsp_pdus_cnt++;
 926         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 927 }
 928
 929 /**
 930  * iscsi_data_in_rsp - SCSI Data-In Response processing
 931  * @conn: iscsi connection
 932  * @hdr:  iscsi pdu
 933  * @task: scsi command task
 934  **/
 935 static void
 936 iscsi_data_in_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 937                   struct iscsi_task *task)
 938 {
 939         struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)hdr;
 940         struct scsi_cmnd *sc = task->sc;
 941
 942         if (!(rhdr->flags & ISCSI_FLAG_DATA_STATUS))
 943                 return;
 944
 945         iscsi_update_cmdsn(conn->session, (struct iscsi_nopin *)hdr);
 946         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 947         conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 948         if (rhdr->flags & (ISCSI_FLAG_DATA_UNDERFLOW |
 949                            ISCSI_FLAG_DATA_OVERFLOW)) {
 950                 int res_count = be32_to_cpu(rhdr->residual_count);
 951
 952                 if (res_count > 0 &&
 953                     (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
 954                      res_count <= scsi_in(sc)->length))
 955                         scsi_in(sc)->resid = res_count;
 956                 else
 957                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 958         }
 959
 960         ISCSI_DBG_SESSION(conn->session, "data in with status done "
 961                           "[sc %p res %d itt 0x%x]\n",
 962                           sc, sc->result, task->itt);
 963         conn->scsirsp_pdus_cnt++;
 964         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 965 }
 966
 967 static void iscsi_tmf_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
 968 {
 969         struct iscsi_tm_rsp *tmf = (struct iscsi_tm_rsp *)hdr;
 970
 971         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 972         conn->tmfrsp_pdus_cnt++;
 973
 974         if (conn->tmf_state != TMF_QUEUED)
 975                 return;
 976
 977         if (tmf->response == ISCSI_TMF_RSP_COMPLETE)
 978                 conn->tmf_state = TMF_SUCCESS;
 979         else if (tmf->response == ISCSI_TMF_RSP_NO_TASK)
 980                 conn->tmf_state = TMF_NOT_FOUND;
 981         else
 982                 conn->tmf_state = TMF_FAILED;
 983         wake_up(&conn->ehwait);
 984 }
 985
 986 static int iscsi_send_nopout(struct iscsi_conn *conn, struct iscsi_nopin *rhdr)
 987 {
 988         struct iscsi_nopout hdr;
 989         struct iscsi_task *task;
 990
 991         if (!rhdr && conn->ping_task)
 992                 return -EINVAL;
 993
 994         memset(&hdr, 0, sizeof(struct iscsi_nopout));
 995         hdr.opcode = ISCSI_OP_NOOP_OUT | ISCSI_OP_IMMEDIATE;
 996         hdr.flags = ISCSI_FLAG_CMD_FINAL;
 997
 998         if (rhdr) {
 999                 hdr.lun = rhdr->lun;
1000                 hdr.ttt = rhdr->ttt;
1001                 hdr.itt = RESERVED_ITT;
1002         } else
1003                 hdr.ttt = RESERVED_ITT;
1004
1005         task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)&hdr, NULL, 0);
1006         if (!task) {
1007                 iscsi_conn_printk(KERN_ERR, conn, "Could not send nopout\n");
1008                 return -EIO;
1009         } else if (!rhdr) {
1010                 /* only track our nops */
1011                 conn->ping_task = task;
1012                 conn->last_ping = jiffies;
1013         }
1014
1015         return 0;
1016 }
1017
1018 static int iscsi_nop_out_rsp(struct iscsi_task *task,
1019                              struct iscsi_nopin *nop, char *data, int datalen)
1020 {
1021         struct iscsi_conn *conn = task->conn;
1022         int rc = 0;
1023
1024         if (conn->ping_task != task) {
1025                 /*
1026                  * If this is not in response to one of our
1027                  * nops then it must be from userspace.
1028                  */
1029                 if (iscsi_recv_pdu(conn->cls_conn, (struct iscsi_hdr *)nop,
1030                                    data, datalen))
1031                         rc = ISCSI_ERR_CONN_FAILED;
1032         } else
1033                 mod_timer(&conn->transport_timer, jiffies + conn->recv_timeout);
1034         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1035         return rc;
1036 }
1037
1038 static int iscsi_handle_reject(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1039                                char *data, int datalen)
1040 {
1041         struct iscsi_reject *reject = (struct iscsi_reject *)hdr;
1042         struct iscsi_hdr rejected_pdu;
1043         int opcode, rc = 0;
1044
1045         conn->exp_statsn = be32_to_cpu(reject->statsn) + 1;
1046
1047         if (ntoh24(reject->dlength) > datalen ||
1048             ntoh24(reject->dlength) < sizeof(struct iscsi_hdr)) {
1049                 iscsi_conn_printk(KERN_ERR, conn, "Cannot handle rejected "
1050                                   "pdu. Invalid data length (pdu dlength "
1051                                   "%u, datalen %d\n", ntoh24(reject->dlength),
1052                                   datalen);
1053                 return ISCSI_ERR_PROTO;
1054         }
1055         memcpy(&rejected_pdu, data, sizeof(struct iscsi_hdr));
1056         opcode = rejected_pdu.opcode & ISCSI_OPCODE_MASK;
1057
1058         switch (reject->reason) {
1059         case ISCSI_REASON_DATA_DIGEST_ERROR:
1060                 iscsi_conn_printk(KERN_ERR, conn,
1061                                   "pdu (op 0x%x itt 0x%x) rejected "
1062                                   "due to DataDigest error.\n",
1063                                   opcode, rejected_pdu.itt);
1064                 break;
1065         case ISCSI_REASON_IMM_CMD_REJECT:
1066                 iscsi_conn_printk(KERN_ERR, conn,
1067                                   "pdu (op 0x%x itt 0x%x) rejected. Too many "
1068                                   "immediate commands.\n",
1069                                   opcode, rejected_pdu.itt);
1070                 /*
1071                  * We only send one TMF at a time so if the target could not
1072                  * handle it, then it should get fixed (RFC mandates that
1073                  * a target can handle one immediate TMF per conn).
1074                  *
1075                  * For nops-outs, we could have sent more than one if
1076                  * the target is sending us lots of nop-ins
1077                  */
1078                 if (opcode != ISCSI_OP_NOOP_OUT)
1079                         return 0;
1080
1081                 if (rejected_pdu.itt == cpu_to_be32(ISCSI_RESERVED_TAG)) {
1082                         /*
1083                          * nop-out in response to target's nop-out rejected.
1084                          * Just resend.
1085                          */
1086                         /* In RX path we are under back lock */
1087                         spin_unlock(&conn->session->back_lock);
1088                         spin_lock(&conn->session->frwd_lock);
1089                         iscsi_send_nopout(conn,
1090                                           (struct iscsi_nopin*)&rejected_pdu);
1091                         spin_unlock(&conn->session->frwd_lock);
1092                         spin_lock(&conn->session->back_lock);
1093                 } else {
1094                         struct iscsi_task *task;
1095                         /*
1096                          * Our nop as ping got dropped. We know the target
1097                          * and transport are ok so just clean up
1098                          */
1099                         task = iscsi_itt_to_task(conn, rejected_pdu.itt);
1100                         if (!task) {
1101                                 iscsi_conn_printk(KERN_ERR, conn,
1102                                                  "Invalid pdu reject. Could "
1103                                                  "not lookup rejected task.\n");
1104                                 rc = ISCSI_ERR_BAD_ITT;
1105                         } else
1106                                 rc = iscsi_nop_out_rsp(task,
1107                                         (struct iscsi_nopin*)&rejected_pdu,
1108                                         NULL, 0);
1109                 }
1110                 break;
1111         default:
1112                 iscsi_conn_printk(KERN_ERR, conn,
1113                                   "pdu (op 0x%x itt 0x%x) rejected. Reason "
1114                                   "code 0x%x\n", rejected_pdu.opcode,
1115                                   rejected_pdu.itt, reject->reason);
1116                 break;
1117         }
1118         return rc;
1119 }
1120
1121 /**
1122  * iscsi_itt_to_task - look up task by itt
1123  * @conn: iscsi connection
1124  * @itt: itt
1125  *
1126  * This should be used for mgmt tasks like login and nops, or if
1127  * the LDD's itt space does not include the session age.
1128  *
1129  * The session back_lock must be held.
1130  */
1131 struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *conn, itt_t itt)
1132 {
1133         struct iscsi_session *session = conn->session;
1134         int i;
1135
1136         if (itt == RESERVED_ITT)
1137                 return NULL;
1138
1139         if (session->tt->parse_pdu_itt)
1140                 session->tt->parse_pdu_itt(conn, itt, &i, NULL);
1141         else
1142                 i = get_itt(itt);
1143         if (i >= session->cmds_max)
1144                 return NULL;
1145
1146         return session->cmds[i];
1147 }
1148 EXPORT_SYMBOL_GPL(iscsi_itt_to_task);
1149
1150 /**
1151  * __iscsi_complete_pdu - complete pdu
1152  * @conn: iscsi conn
1153  * @hdr: iscsi header
1154  * @data: data buffer
1155  * @datalen: len of data buffer
1156  *
1157  * Completes pdu processing by freeing any resources allocated at
1158  * queuecommand or send generic. session back_lock must be held and verify
1159  * itt must have been called.
1160  */
1161 int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1162                          char *data, int datalen)
1163 {
1164         struct iscsi_session *session = conn->session;
1165         int opcode = hdr->opcode & ISCSI_OPCODE_MASK, rc = 0;
1166         struct iscsi_task *task;
1167         uint32_t itt;
1168
1169         conn->last_recv = jiffies;
1170         rc = iscsi_verify_itt(conn, hdr->itt);
1171         if (rc)
1172                 return rc;
1173
1174         if (hdr->itt != RESERVED_ITT)
1175                 itt = get_itt(hdr->itt);
1176         else
1177                 itt = ~0U;
1178
1179         ISCSI_DBG_SESSION(session, "[op 0x%x cid %d itt 0x%x len %d]\n",
1180                           opcode, conn->id, itt, datalen);
1181
1182         if (itt == ~0U) {
1183                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1184
1185                 switch(opcode) {
1186                 case ISCSI_OP_NOOP_IN:
1187                         if (datalen) {
1188                                 rc = ISCSI_ERR_PROTO;
1189                                 break;
1190                         }
1191
1192                         if (hdr->ttt == cpu_to_be32(ISCSI_RESERVED_TAG))
1193                                 break;
1194
1195                         /* In RX path we are under back lock */
1196                         spin_unlock(&session->back_lock);
1197                         spin_lock(&session->frwd_lock);
1198                         iscsi_send_nopout(conn, (struct iscsi_nopin*)hdr);
1199                         spin_unlock(&session->frwd_lock);
1200                         spin_lock(&session->back_lock);
1201                         break;
1202                 case ISCSI_OP_REJECT:
1203                         rc = iscsi_handle_reject(conn, hdr, data, datalen);
1204                         break;
1205                 case ISCSI_OP_ASYNC_EVENT:
1206                         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1207                         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
1208                                 rc = ISCSI_ERR_CONN_FAILED;
1209                         break;
1210                 default:
1211                         rc = ISCSI_ERR_BAD_OPCODE;
1212                         break;
1213                 }
1214                 goto out;
1215         }
1216
1217         switch(opcode) {
1218         case ISCSI_OP_SCSI_CMD_RSP:
1219         case ISCSI_OP_SCSI_DATA_IN:
1220                 task = iscsi_itt_to_ctask(conn, hdr->itt);
1221                 if (!task)
1222                         return ISCSI_ERR_BAD_ITT;
1223                 task->last_xfer = jiffies;
1224                 break;
1225         case ISCSI_OP_R2T:
1226                 /*
1227                  * LLD handles R2Ts if they need to.
1228                  */
1229                 return 0;
1230         case ISCSI_OP_LOGOUT_RSP:
1231         case ISCSI_OP_LOGIN_RSP:
1232         case ISCSI_OP_TEXT_RSP:
1233         case ISCSI_OP_SCSI_TMFUNC_RSP:
1234         case ISCSI_OP_NOOP_IN:
1235                 task = iscsi_itt_to_task(conn, hdr->itt);
1236                 if (!task)
1237                         return ISCSI_ERR_BAD_ITT;
1238                 break;
1239         default:
1240                 return ISCSI_ERR_BAD_OPCODE;
1241         }
1242
1243         switch(opcode) {
1244         case ISCSI_OP_SCSI_CMD_RSP:
1245                 iscsi_scsi_cmd_rsp(conn, hdr, task, data, datalen);
1246                 break;
1247         case ISCSI_OP_SCSI_DATA_IN:
1248                 iscsi_data_in_rsp(conn, hdr, task);
1249                 break;
1250         case ISCSI_OP_LOGOUT_RSP:
1251                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1252                 if (datalen) {
1253                         rc = ISCSI_ERR_PROTO;
1254                         break;
1255                 }
1256                 conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1257                 goto recv_pdu;
1258         case ISCSI_OP_LOGIN_RSP:
1259         case ISCSI_OP_TEXT_RSP:
1260                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1261                 /*
1262                  * login related PDU's exp_statsn is handled in
1263                  * userspace
1264                  */
1265                 goto recv_pdu;
1266         case ISCSI_OP_SCSI_TMFUNC_RSP:
1267                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1268                 if (datalen) {
1269                         rc = ISCSI_ERR_PROTO;
1270                         break;
1271                 }
1272
1273                 iscsi_tmf_rsp(conn, hdr);
1274                 iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1275                 break;
1276         case ISCSI_OP_NOOP_IN:
1277                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
1278                 if (hdr->ttt != cpu_to_be32(ISCSI_RESERVED_TAG) || datalen) {
1279                         rc = ISCSI_ERR_PROTO;
1280                         break;
1281                 }
1282                 conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
1283
1284                 rc = iscsi_nop_out_rsp(task, (struct iscsi_nopin*)hdr,
1285                                        data, datalen);
1286                 break;
1287         default:
1288                 rc = ISCSI_ERR_BAD_OPCODE;
1289                 break;
1290         }
1291
1292 out:
1293         return rc;
1294 recv_pdu:
1295         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
1296                 rc = ISCSI_ERR_CONN_FAILED;
1297         iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
1298         return rc;
1299 }
1300 EXPORT_SYMBOL_GPL(__iscsi_complete_pdu);
1301
1302 int iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
1303                        char *data, int datalen)
1304 {
1305         int rc;
1306
1307         spin_lock(&conn->session->back_lock);
1308         rc = __iscsi_complete_pdu(conn, hdr, data, datalen);
1309         spin_unlock(&conn->session->back_lock);
1310         return rc;
1311 }
1312 EXPORT_SYMBOL_GPL(iscsi_complete_pdu);
1313
1314 int iscsi_verify_itt(struct iscsi_conn *conn, itt_t itt)
1315 {
1316         struct iscsi_session *session = conn->session;
1317         int age = 0, i = 0;
1318
1319         if (itt == RESERVED_ITT)
1320                 return 0;
1321
1322         if (session->tt->parse_pdu_itt)
1323                 session->tt->parse_pdu_itt(conn, itt, &i, &age);
1324         else {
1325                 i = get_itt(itt);
1326                 age = ((__force u32)itt >> ISCSI_AGE_SHIFT) & ISCSI_AGE_MASK;
1327         }
1328
1329         if (age != session->age) {
1330                 iscsi_conn_printk(KERN_ERR, conn,
1331                                   "received itt %x expected session age (%x)\n",
1332                                   (__force u32)itt, session->age);
1333                 return ISCSI_ERR_BAD_ITT;
1334         }
1335
1336         if (i >= session->cmds_max) {
1337                 iscsi_conn_printk(KERN_ERR, conn,
1338                                   "received invalid itt index %u (max cmds "
1339                                    "%u.\n", i, session->cmds_max);
1340                 return ISCSI_ERR_BAD_ITT;
1341         }
1342         return 0;
1343 }
1344 EXPORT_SYMBOL_GPL(iscsi_verify_itt);
1345
1346 /**
1347  * iscsi_itt_to_ctask - look up ctask by itt
1348  * @conn: iscsi connection
1349  * @itt: itt
1350  *
1351  * This should be used for cmd tasks.
1352  *
1353  * The session back_lock must be held.
1354  */
1355 struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *conn, itt_t itt)
1356 {
1357         struct iscsi_task *task;
1358
1359         if (iscsi_verify_itt(conn, itt))
1360                 return NULL;
1361
1362         task = iscsi_itt_to_task(conn, itt);
1363         if (!task || !task->sc)
1364                 return NULL;
1365
1366         if (task->sc->SCp.phase != conn->session->age) {
1367                 iscsi_session_printk(KERN_ERR, conn->session,
1368                                   "task's session age %d, expected %d\n",
1369                                   task->sc->SCp.phase, conn->session->age);
1370                 return NULL;
1371         }
1372
1373         return task;
1374 }
1375 EXPORT_SYMBOL_GPL(iscsi_itt_to_ctask);
1376
1377 void iscsi_session_failure(struct iscsi_session *session,
1378                            enum iscsi_err err)
1379 {
1380         struct iscsi_conn *conn;
1381         struct device *dev;
1382
1383         spin_lock_bh(&session->frwd_lock);
1384         conn = session->leadconn;
1385         if (session->state == ISCSI_STATE_TERMINATE || !conn) {
1386                 spin_unlock_bh(&session->frwd_lock);
1387                 return;
1388         }
1389
1390         dev = get_device(&conn->cls_conn->dev);
1391         spin_unlock_bh(&session->frwd_lock);
1392         if (!dev)
1393                 return;
1394         /*
1395          * if the host is being removed bypass the connection
1396          * recovery initialization because we are going to kill
1397          * the session.
1398          */
1399         if (err == ISCSI_ERR_INVALID_HOST)
1400                 iscsi_conn_error_event(conn->cls_conn, err);
1401         else
1402                 iscsi_conn_failure(conn, err);
1403         put_device(dev);
1404 }
1405 EXPORT_SYMBOL_GPL(iscsi_session_failure);
1406
1407 void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err)
1408 {
1409         struct iscsi_session *session = conn->session;
1410
1411         spin_lock_bh(&session->frwd_lock);
1412         if (session->state == ISCSI_STATE_FAILED) {
1413                 spin_unlock_bh(&session->frwd_lock);
1414                 return;
1415         }
1416
1417         if (conn->stop_stage == 0)
1418                 session->state = ISCSI_STATE_FAILED;
1419         spin_unlock_bh(&session->frwd_lock);
1420
1421         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1422         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
1423         iscsi_conn_error_event(conn->cls_conn, err);
1424 }
1425 EXPORT_SYMBOL_GPL(iscsi_conn_failure);
1426
1427 static int iscsi_check_cmdsn_window_closed(struct iscsi_conn *conn)
1428 {
1429         struct iscsi_session *session = conn->session;
1430
1431         /*
1432          * Check for iSCSI window and take care of CmdSN wrap-around
1433          */
1434         if (!iscsi_sna_lte(session->queued_cmdsn, session->max_cmdsn)) {
1435                 ISCSI_DBG_SESSION(session, "iSCSI CmdSN closed. ExpCmdSn "
1436                                   "%u MaxCmdSN %u CmdSN %u/%u\n",
1437                                   session->exp_cmdsn, session->max_cmdsn,
1438                                   session->cmdsn, session->queued_cmdsn);
1439                 return -ENOSPC;
1440         }
1441         return 0;
1442 }
1443
1444 static int iscsi_xmit_task(struct iscsi_conn *conn)
1445 {
1446         struct iscsi_task *task = conn->task;
1447         int rc;
1448
1449         if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx))
1450                 return -ENODATA;
1451
1452         __iscsi_get_task(task);
1453         spin_unlock_bh(&conn->session->frwd_lock);
1454         rc = conn->session->tt->xmit_task(task);
1455         spin_lock_bh(&conn->session->frwd_lock);
1456         if (!rc) {
1457                 /* done with this task */
1458                 task->last_xfer = jiffies;
1459                 conn->task = NULL;
1460         }
1461         /* regular RX path uses back_lock */
1462         spin_lock(&conn->session->back_lock);
1463         __iscsi_put_task(task);
1464         spin_unlock(&conn->session->back_lock);
1465         return rc;
1466 }
1467
1468 /**
1469  * iscsi_requeue_task - requeue task to run from session workqueue
1470  * @task: task to requeue
1471  *
1472  * LLDs that need to run a task from the session workqueue should call
1473  * this. The session frwd_lock must be held. This should only be called
1474  * by software drivers.
1475  */
1476 void iscsi_requeue_task(struct iscsi_task *task)
1477 {
1478         struct iscsi_conn *conn = task->conn;
1479
1480         /*
1481          * this may be on the requeue list already if the xmit_task callout
1482          * is handling the r2ts while we are adding new ones
1483          */
1484         spin_lock_bh(&conn->taskqueuelock);
1485         if (list_empty(&task->running))
1486                 list_add_tail(&task->running, &conn->requeue);
1487         spin_unlock_bh(&conn->taskqueuelock);
1488         iscsi_conn_queue_work(conn);
1489 }
1490 EXPORT_SYMBOL_GPL(iscsi_requeue_task);
1491
1492 /**
1493  * iscsi_data_xmit - xmit any command into the scheduled connection
1494  * @conn: iscsi connection
1495  *
1496  * Notes:
1497  *      The function can return -EAGAIN in which case the caller must
1498  *      re-schedule it again later or recover. '0' return code means
1499  *      successful xmit.
1500  **/
1501 static int iscsi_data_xmit(struct iscsi_conn *conn)
1502 {
1503         struct iscsi_task *task;
1504         int rc = 0;
1505
1506         spin_lock_bh(&conn->session->frwd_lock);
1507         if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx)) {
1508                 ISCSI_DBG_SESSION(conn->session, "Tx suspended!\n");
1509                 spin_unlock_bh(&conn->session->frwd_lock);
1510                 return -ENODATA;
1511         }
1512
1513         if (conn->task) {
1514                 rc = iscsi_xmit_task(conn);
1515                 if (rc)
1516                         goto done;
1517         }
1518
1519         /*
1520          * process mgmt pdus like nops before commands since we should
1521          * only have one nop-out as a ping from us and targets should not
1522          * overflow us with nop-ins
1523          */
1524         spin_lock_bh(&conn->taskqueuelock);
1525 check_mgmt:
1526         while (!list_empty(&conn->mgmtqueue)) {
1527                 conn->task = list_entry(conn->mgmtqueue.next,
1528                                          struct iscsi_task, running);
1529                 list_del_init(&conn->task->running);
1530                 spin_unlock_bh(&conn->taskqueuelock);
1531                 if (iscsi_prep_mgmt_task(conn, conn->task)) {
1532                         /* regular RX path uses back_lock */
1533                         spin_lock_bh(&conn->session->back_lock);
1534                         __iscsi_put_task(conn->task);
1535                         spin_unlock_bh(&conn->session->back_lock);
1536                         conn->task = NULL;
1537                         spin_lock_bh(&conn->taskqueuelock);
1538                         continue;
1539                 }
1540                 rc = iscsi_xmit_task(conn);
1541                 if (rc)
1542                         goto done;
1543                 spin_lock_bh(&conn->taskqueuelock);
1544         }
1545
1546         /* process pending command queue */
1547         while (!list_empty(&conn->cmdqueue)) {
1548                 conn->task = list_entry(conn->cmdqueue.next, struct iscsi_task,
1549                                         running);
1550                 list_del_init(&conn->task->running);
1551                 spin_unlock_bh(&conn->taskqueuelock);
1552                 if (conn->session->state == ISCSI_STATE_LOGGING_OUT) {
1553                         fail_scsi_task(conn->task, DID_IMM_RETRY);
1554                         spin_lock_bh(&conn->taskqueuelock);
1555                         continue;
1556                 }
1557                 rc = iscsi_prep_scsi_cmd_pdu(conn->task);
1558                 if (rc) {
1559                         if (rc == -ENOMEM || rc == -EACCES) {
1560                                 spin_lock_bh(&conn->taskqueuelock);
1561                                 list_add_tail(&conn->task->running,
1562                                               &conn->cmdqueue);
1563                                 conn->task = NULL;
1564                                 spin_unlock_bh(&conn->taskqueuelock);
1565                                 goto done;
1566                         } else
1567                                 fail_scsi_task(conn->task, DID_ABORT);
1568                         spin_lock_bh(&conn->taskqueuelock);
1569                         continue;
1570                 }
1571                 rc = iscsi_xmit_task(conn);
1572                 if (rc)
1573                         goto done;
1574                 /*
1575                  * we could continuously get new task requests so
1576                  * we need to check the mgmt queue for nops that need to
1577                  * be sent to aviod starvation
1578                  */
1579                 spin_lock_bh(&conn->taskqueuelock);
1580                 if (!list_empty(&conn->mgmtqueue))
1581                         goto check_mgmt;
1582         }
1583
1584         while (!list_empty(&conn->requeue)) {
1585                 /*
1586                  * we always do fastlogout - conn stop code will clean up.
1587                  */
1588                 if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
1589                         break;
1590
1591                 task = list_entry(conn->requeue.next, struct iscsi_task,
1592                                   running);
1593                 if (iscsi_check_tmf_restrictions(task, ISCSI_OP_SCSI_DATA_OUT))
1594                         break;
1595
1596                 conn->task = task;
1597                 list_del_init(&conn->task->running);
1598                 conn->task->state = ISCSI_TASK_RUNNING;
1599                 spin_unlock_bh(&conn->taskqueuelock);
1600                 rc = iscsi_xmit_task(conn);
1601                 if (rc)
1602                         goto done;
1603                 spin_lock_bh(&conn->taskqueuelock);
1604                 if (!list_empty(&conn->mgmtqueue))
1605                         goto check_mgmt;
1606         }
1607         spin_unlock_bh(&conn->taskqueuelock);
1608         spin_unlock_bh(&conn->session->frwd_lock);
1609         return -ENODATA;
1610
1611 done:
1612         spin_unlock_bh(&conn->session->frwd_lock);
1613         return rc;
1614 }
1615
1616 static void iscsi_xmitworker(struct work_struct *work)
1617 {
1618         struct iscsi_conn *conn =
1619                 container_of(work, struct iscsi_conn, xmitwork);
1620         int rc;
1621         /*
1622          * serialize Xmit worker on a per-connection basis.
1623          */
1624         do {
1625                 rc = iscsi_data_xmit(conn);
1626         } while (rc >= 0 || rc == -EAGAIN);
1627 }
1628
1629 static inline struct iscsi_task *iscsi_alloc_task(struct iscsi_conn *conn,
1630                                                   struct scsi_cmnd *sc)
1631 {
1632         struct iscsi_task *task;
1633
1634         if (!kfifo_out(&conn->session->cmdpool.queue,
1635                          (void *) &task, sizeof(void *)))
1636                 return NULL;
1637
1638         sc->SCp.phase = conn->session->age;
1639         sc->SCp.ptr = (char *) task;
1640
1641         refcount_set(&task->refcount, 1);
1642         task->state = ISCSI_TASK_PENDING;
1643         task->conn = conn;
1644         task->sc = sc;
1645         task->have_checked_conn = false;
1646         task->last_timeout = jiffies;
1647         task->last_xfer = jiffies;
1648         task->protected = false;
1649         INIT_LIST_HEAD(&task->running);
1650         return task;
1651 }
1652
1653 enum {
1654         FAILURE_BAD_HOST = 1,
1655         FAILURE_SESSION_FAILED,
1656         FAILURE_SESSION_FREED,
1657         FAILURE_WINDOW_CLOSED,
1658         FAILURE_OOM,
1659         FAILURE_SESSION_TERMINATE,
1660         FAILURE_SESSION_IN_RECOVERY,
1661         FAILURE_SESSION_RECOVERY_TIMEOUT,
1662         FAILURE_SESSION_LOGGING_OUT,
1663         FAILURE_SESSION_NOT_READY,
1664 };
1665
1666 int iscsi_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *sc)
1667 {
1668         struct iscsi_cls_session *cls_session;
1669         struct iscsi_host *ihost;
1670         int reason = 0;
1671         struct iscsi_session *session;
1672         struct iscsi_conn *conn;
1673         struct iscsi_task *task = NULL;
1674
1675         sc->result = 0;
1676         sc->SCp.ptr = NULL;
1677
1678         ihost = shost_priv(host);
1679
1680         cls_session = starget_to_session(scsi_target(sc->device));
1681         session = cls_session->dd_data;
1682         spin_lock_bh(&session->frwd_lock);
1683
1684         reason = iscsi_session_chkready(cls_session);
1685         if (reason) {
1686                 sc->result = reason;
1687                 goto fault;
1688         }
1689
1690         if (session->state != ISCSI_STATE_LOGGED_IN) {
1691                 /*
1692                  * to handle the race between when we set the recovery state
1693                  * and block the session we requeue here (commands could
1694                  * be entering our queuecommand while a block is starting
1695                  * up because the block code is not locked)
1696                  */
1697                 switch (session->state) {
1698                 case ISCSI_STATE_FAILED:
1699                         /*
1700                          * cmds should fail during shutdown, if the session
1701                          * state is bad, allowing completion to happen
1702                          */
1703                         if (unlikely(system_state != SYSTEM_RUNNING)) {
1704                                 reason = FAILURE_SESSION_FAILED;
1705                                 sc->result = DID_NO_CONNECT << 16;
1706                                 break;
1707                         }
1708                 case ISCSI_STATE_IN_RECOVERY:
1709                         reason = FAILURE_SESSION_IN_RECOVERY;
1710                         sc->result = DID_IMM_RETRY << 16;
1711                         break;
1712                 case ISCSI_STATE_LOGGING_OUT:
1713                         reason = FAILURE_SESSION_LOGGING_OUT;
1714                         sc->result = DID_IMM_RETRY << 16;
1715                         break;
1716                 case ISCSI_STATE_RECOVERY_FAILED:
1717                         reason = FAILURE_SESSION_RECOVERY_TIMEOUT;
1718                         sc->result = DID_TRANSPORT_FAILFAST << 16;
1719                         break;
1720                 case ISCSI_STATE_TERMINATE:
1721                         reason = FAILURE_SESSION_TERMINATE;
1722                         sc->result = DID_NO_CONNECT << 16;
1723                         break;
1724                 default:
1725                         reason = FAILURE_SESSION_FREED;
1726                         sc->result = DID_NO_CONNECT << 16;
1727                 }
1728                 goto fault;
1729         }
1730
1731         conn = session->leadconn;
1732         if (!conn) {
1733                 reason = FAILURE_SESSION_FREED;
1734                 sc->result = DID_NO_CONNECT << 16;
1735                 goto fault;
1736         }
1737
1738         if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx)) {
1739                 reason = FAILURE_SESSION_IN_RECOVERY;
1740                 sc->result = DID_REQUEUE << 16;
1741                 goto fault;
1742         }
1743
1744         if (iscsi_check_cmdsn_window_closed(conn)) {
1745                 reason = FAILURE_WINDOW_CLOSED;
1746                 goto reject;
1747         }
1748
1749         task = iscsi_alloc_task(conn, sc);
1750         if (!task) {
1751                 reason = FAILURE_OOM;
1752                 goto reject;
1753         }
1754
1755         if (!ihost->workq) {
1756                 reason = iscsi_prep_scsi_cmd_pdu(task);
1757                 if (reason) {
1758                         if (reason == -ENOMEM ||  reason == -EACCES) {
1759                                 reason = FAILURE_OOM;
1760                                 goto prepd_reject;
1761                         } else {
1762                                 sc->result = DID_ABORT << 16;
1763                                 goto prepd_fault;
1764                         }
1765                 }
1766                 if (session->tt->xmit_task(task)) {
1767                         session->cmdsn--;
1768                         reason = FAILURE_SESSION_NOT_READY;
1769                         goto prepd_reject;
1770                 }
1771         } else {
1772                 spin_lock_bh(&conn->taskqueuelock);
1773                 list_add_tail(&task->running, &conn->cmdqueue);
1774                 spin_unlock_bh(&conn->taskqueuelock);
1775                 iscsi_conn_queue_work(conn);
1776         }
1777
1778         session->queued_cmdsn++;
1779         spin_unlock_bh(&session->frwd_lock);
1780         return 0;
1781
1782 prepd_reject:
1783         iscsi_complete_task(task, ISCSI_TASK_REQUEUE_SCSIQ);
1784 reject:
1785         spin_unlock_bh(&session->frwd_lock);
1786         ISCSI_DBG_SESSION(session, "cmd 0x%x rejected (%d)\n",
1787                           sc->cmnd[0], reason);
1788         return SCSI_MLQUEUE_TARGET_BUSY;
1789
1790 prepd_fault:
1791         iscsi_complete_task(task, ISCSI_TASK_REQUEUE_SCSIQ);
1792 fault:
1793         spin_unlock_bh(&session->frwd_lock);
1794         ISCSI_DBG_SESSION(session, "iscsi: cmd 0x%x is not queued (%d)\n",
1795                           sc->cmnd[0], reason);
1796         if (!scsi_bidi_cmnd(sc))
1797                 scsi_set_resid(sc, scsi_bufflen(sc));
1798         else {
1799                 scsi_out(sc)->resid = scsi_out(sc)->length;
1800                 scsi_in(sc)->resid = scsi_in(sc)->length;
1801         }
1802         sc->scsi_done(sc);
1803         return 0;
1804 }
1805 EXPORT_SYMBOL_GPL(iscsi_queuecommand);
1806
1807 int iscsi_target_alloc(struct scsi_target *starget)
1808 {
1809         struct iscsi_cls_session *cls_session = starget_to_session(starget);
1810         struct iscsi_session *session = cls_session->dd_data;
1811
1812         starget->can_queue = session->scsi_cmds_max;
1813         return 0;
1814 }
1815 EXPORT_SYMBOL_GPL(iscsi_target_alloc);
1816
1817 static void iscsi_tmf_timedout(struct timer_list *t)
1818 {
1819         struct iscsi_conn *conn = from_timer(conn, t, tmf_timer);
1820         struct iscsi_session *session = conn->session;
1821
1822         spin_lock(&session->frwd_lock);
1823         if (conn->tmf_state == TMF_QUEUED) {
1824                 conn->tmf_state = TMF_TIMEDOUT;
1825                 ISCSI_DBG_EH(session, "tmf timedout\n");
1826                 /* unblock eh_abort() */
1827                 wake_up(&conn->ehwait);
1828         }
1829         spin_unlock(&session->frwd_lock);
1830 }
1831
1832 static int iscsi_exec_task_mgmt_fn(struct iscsi_conn *conn,
1833                                    struct iscsi_tm *hdr, int age,
1834                                    int timeout)
1835         __must_hold(&session->frwd_lock)
1836 {
1837         struct iscsi_session *session = conn->session;
1838         struct iscsi_task *task;
1839
1840         task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)hdr,
1841                                       NULL, 0);
1842         if (!task) {
1843                 spin_unlock_bh(&session->frwd_lock);
1844                 iscsi_conn_printk(KERN_ERR, conn, "Could not send TMF.\n");
1845                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1846                 spin_lock_bh(&session->frwd_lock);
1847                 return -EPERM;
1848         }
1849         conn->tmfcmd_pdus_cnt++;
1850         conn->tmf_timer.expires = timeout * HZ + jiffies;
1851         add_timer(&conn->tmf_timer);
1852         ISCSI_DBG_EH(session, "tmf set timeout\n");
1853
1854         spin_unlock_bh(&session->frwd_lock);
1855         mutex_unlock(&session->eh_mutex);
1856
1857         /*
1858          * block eh thread until:
1859          *
1860          * 1) tmf response
1861          * 2) tmf timeout
1862          * 3) session is terminated or restarted or userspace has
1863          * given up on recovery
1864          */
1865         wait_event_interruptible(conn->ehwait, age != session->age ||
1866                                  session->state != ISCSI_STATE_LOGGED_IN ||
1867                                  conn->tmf_state != TMF_QUEUED);
1868         if (signal_pending(current))
1869                 flush_signals(current);
1870         del_timer_sync(&conn->tmf_timer);
1871
1872         mutex_lock(&session->eh_mutex);
1873         spin_lock_bh(&session->frwd_lock);
1874         /* if the session drops it will clean up the task */
1875         if (age != session->age ||
1876             session->state != ISCSI_STATE_LOGGED_IN)
1877                 return -ENOTCONN;
1878         return 0;
1879 }
1880
1881 /*
1882  * Fail commands. session lock held and recv side suspended and xmit
1883  * thread flushed
1884  */
1885 static void fail_scsi_tasks(struct iscsi_conn *conn, u64 lun, int error)
1886 {
1887         struct iscsi_task *task;
1888         int i;
1889
1890         for (i = 0; i < conn->session->cmds_max; i++) {
1891                 task = conn->session->cmds[i];
1892                 if (!task->sc || task->state == ISCSI_TASK_FREE)
1893                         continue;
1894
1895                 if (lun != -1 && lun != task->sc->device->lun)
1896                         continue;
1897
1898                 ISCSI_DBG_SESSION(conn->session,
1899                                   "failing sc %p itt 0x%x state %d\n",
1900                                   task->sc, task->itt, task->state);
1901                 fail_scsi_task(task, error);
1902         }
1903 }
1904
1905 /**
1906  * iscsi_suspend_queue - suspend iscsi_queuecommand
1907  * @conn: iscsi conn to stop queueing IO on
1908  *
1909  * This grabs the session frwd_lock to make sure no one is in
1910  * xmit_task/queuecommand, and then sets suspend to prevent
1911  * new commands from being queued. This only needs to be called
1912  * by offload drivers that need to sync a path like ep disconnect
1913  * with the iscsi_queuecommand/xmit_task. To start IO again libiscsi
1914  * will call iscsi_start_tx and iscsi_unblock_session when in FFP.
1915  */
1916 void iscsi_suspend_queue(struct iscsi_conn *conn)
1917 {
1918         spin_lock_bh(&conn->session->frwd_lock);
1919         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1920         spin_unlock_bh(&conn->session->frwd_lock);
1921 }
1922 EXPORT_SYMBOL_GPL(iscsi_suspend_queue);
1923
1924 /**
1925  * iscsi_suspend_tx - suspend iscsi_data_xmit
1926  * @conn: iscsi conn tp stop processing IO on.
1927  *
1928  * This function sets the suspend bit to prevent iscsi_data_xmit
1929  * from sending new IO, and if work is queued on the xmit thread
1930  * it will wait for it to be completed.
1931  */
1932 void iscsi_suspend_tx(struct iscsi_conn *conn)
1933 {
1934         struct Scsi_Host *shost = conn->session->host;
1935         struct iscsi_host *ihost = shost_priv(shost);
1936
1937         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1938         if (ihost->workq)
1939                 flush_workqueue(ihost->workq);
1940 }
1941 EXPORT_SYMBOL_GPL(iscsi_suspend_tx);
1942
1943 static void iscsi_start_tx(struct iscsi_conn *conn)
1944 {
1945         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1946         iscsi_conn_queue_work(conn);
1947 }
1948
1949 /*
1950  * We want to make sure a ping is in flight. It has timed out.
1951  * And we are not busy processing a pdu that is making
1952  * progress but got started before the ping and is taking a while
1953  * to complete so the ping is just stuck behind it in a queue.
1954  */
1955 static int iscsi_has_ping_timed_out(struct iscsi_conn *conn)
1956 {
1957         if (conn->ping_task &&
1958             time_before_eq(conn->last_recv + (conn->recv_timeout * HZ) +
1959                            (conn->ping_timeout * HZ), jiffies))
1960                 return 1;
1961         else
1962                 return 0;
1963 }
1964
1965 enum blk_eh_timer_return iscsi_eh_cmd_timed_out(struct scsi_cmnd *sc)
1966 {
1967         enum blk_eh_timer_return rc = BLK_EH_DONE;
1968         struct iscsi_task *task = NULL, *running_task;
1969         struct iscsi_cls_session *cls_session;
1970         struct iscsi_session *session;
1971         struct iscsi_conn *conn;
1972         int i;
1973
1974         cls_session = starget_to_session(scsi_target(sc->device));
1975         session = cls_session->dd_data;
1976
1977         ISCSI_DBG_EH(session, "scsi cmd %p timedout\n", sc);
1978
1979         spin_lock(&session->frwd_lock);
1980         task = (struct iscsi_task *)sc->SCp.ptr;
1981         if (!task) {
1982                 /*
1983                  * Raced with completion. Blk layer has taken ownership
1984                  * so let timeout code complete it now.
1985                  */
1986                 rc = BLK_EH_DONE;
1987                 goto done;
1988         }
1989
1990         if (session->state != ISCSI_STATE_LOGGED_IN) {
1991                 /*
1992                  * During shutdown, if session is prematurely disconnected,
1993                  * recovery won't happen and there will be hung cmds. Not
1994                  * handling cmds would trigger EH, also bad in this case.
1995                  * Instead, handle cmd, allow completion to happen and let
1996                  * upper layer to deal with the result.
1997                  */
1998                 if (unlikely(system_state != SYSTEM_RUNNING)) {
1999                         sc->result = DID_NO_CONNECT << 16;
2000                         ISCSI_DBG_EH(session, "sc on shutdown, handled\n");
2001                         rc = BLK_EH_DONE;
2002                         goto done;
2003                 }
2004                 /*
2005                  * We are probably in the middle of iscsi recovery so let
2006                  * that complete and handle the error.
2007                  */
2008                 rc = BLK_EH_RESET_TIMER;
2009                 goto done;
2010         }
2011
2012         conn = session->leadconn;
2013         if (!conn) {
2014                 /* In the middle of shuting down */
2015                 rc = BLK_EH_RESET_TIMER;
2016                 goto done;
2017         }
2018
2019         /*
2020          * If we have sent (at least queued to the network layer) a pdu or
2021          * recvd one for the task since the last timeout ask for
2022          * more time. If on the next timeout we have not made progress
2023          * we can check if it is the task or connection when we send the
2024          * nop as a ping.
2025          */
2026         if (time_after(task->last_xfer, task->last_timeout)) {
2027                 ISCSI_DBG_EH(session, "Command making progress. Asking "
2028                              "scsi-ml for more time to complete. "
2029                              "Last data xfer at %lu. Last timeout was at "
2030                              "%lu\n.", task->last_xfer, task->last_timeout);
2031                 task->have_checked_conn = false;
2032                 rc = BLK_EH_RESET_TIMER;
2033                 goto done;
2034         }
2035
2036         if (!conn->recv_timeout && !conn->ping_timeout)
2037                 goto done;
2038         /*
2039          * if the ping timedout then we are in the middle of cleaning up
2040          * and can let the iscsi eh handle it
2041          */
2042         if (iscsi_has_ping_timed_out(conn)) {
2043                 rc = BLK_EH_RESET_TIMER;
2044                 goto done;
2045         }
2046
2047         for (i = 0; i < conn->session->cmds_max; i++) {
2048                 running_task = conn->session->cmds[i];
2049                 if (!running_task->sc || running_task == task ||
2050                      running_task->state != ISCSI_TASK_RUNNING)
2051                         continue;
2052
2053                 /*
2054                  * Only check if cmds started before this one have made
2055                  * progress, or this could never fail
2056                  */
2057                 if (time_after(running_task->sc->jiffies_at_alloc,
2058                                task->sc->jiffies_at_alloc))
2059                         continue;
2060
2061                 if (time_after(running_task->last_xfer, task->last_timeout)) {
2062                         /*
2063                          * This task has not made progress, but a task
2064                          * started before us has transferred data since
2065                          * we started/last-checked. We could be queueing
2066                          * too many tasks or the LU is bad.
2067                          *
2068                          * If the device is bad the cmds ahead of us on
2069                          * other devs will complete, and this loop will
2070                          * eventually fail starting the scsi eh.
2071                          */
2072                         ISCSI_DBG_EH(session, "Command has not made progress "
2073                                      "but commands ahead of it have. "
2074                                      "Asking scsi-ml for more time to "
2075                                      "complete. Our last xfer vs running task "
2076                                      "last xfer %lu/%lu. Last check %lu.\n",
2077                                      task->last_xfer, running_task->last_xfer,
2078                                      task->last_timeout);
2079                         rc = BLK_EH_RESET_TIMER;
2080                         goto done;
2081                 }
2082         }
2083
2084         /* Assumes nop timeout is shorter than scsi cmd timeout */
2085         if (task->have_checked_conn)
2086                 goto done;
2087
2088         /*
2089          * Checking the transport already or nop from a cmd timeout still
2090          * running
2091          */
2092         if (conn->ping_task) {
2093                 task->have_checked_conn = true;
2094                 rc = BLK_EH_RESET_TIMER;
2095                 goto done;
2096         }
2097
2098         /* Make sure there is a transport check done */
2099         iscsi_send_nopout(conn, NULL);
2100         task->have_checked_conn = true;
2101         rc = BLK_EH_RESET_TIMER;
2102
2103 done:
2104         if (task)
2105                 task->last_timeout = jiffies;
2106         spin_unlock(&session->frwd_lock);
2107         ISCSI_DBG_EH(session, "return %s\n", rc == BLK_EH_RESET_TIMER ?
2108                      "timer reset" : "shutdown or nh");
2109         return rc;
2110 }
2111 EXPORT_SYMBOL_GPL(iscsi_eh_cmd_timed_out);
2112
2113 static void iscsi_check_transport_timeouts(struct timer_list *t)
2114 {
2115         struct iscsi_conn *conn = from_timer(conn, t, transport_timer);
2116         struct iscsi_session *session = conn->session;
2117         unsigned long recv_timeout, next_timeout = 0, last_recv;
2118
2119         spin_lock(&session->frwd_lock);
2120         if (session->state != ISCSI_STATE_LOGGED_IN)
2121                 goto done;
2122
2123         recv_timeout = conn->recv_timeout;
2124         if (!recv_timeout)
2125                 goto done;
2126
2127         recv_timeout *= HZ;
2128         last_recv = conn->last_recv;
2129
2130         if (iscsi_has_ping_timed_out(conn)) {
2131                 iscsi_conn_printk(KERN_ERR, conn, "ping timeout of %d secs "
2132                                   "expired, recv timeout %d, last rx %lu, "
2133                                   "last ping %lu, now %lu\n",
2134                                   conn->ping_timeout, conn->recv_timeout,
2135                                   last_recv, conn->last_ping, jiffies);
2136                 spin_unlock(&session->frwd_lock);
2137                 iscsi_conn_failure(conn, ISCSI_ERR_NOP_TIMEDOUT);
2138                 return;
2139         }
2140
2141         if (time_before_eq(last_recv + recv_timeout, jiffies)) {
2142                 /* send a ping to try to provoke some traffic */
2143                 ISCSI_DBG_CONN(conn, "Sending nopout as ping\n");
2144                 if (iscsi_send_nopout(conn, NULL))
2145                         next_timeout = jiffies + (1 * HZ);
2146                 else
2147                         next_timeout = conn->last_ping + (conn->ping_timeout * HZ);
2148         } else
2149                 next_timeout = last_recv + recv_timeout;
2150
2151         ISCSI_DBG_CONN(conn, "Setting next tmo %lu\n", next_timeout);
2152         mod_timer(&conn->transport_timer, next_timeout);
2153 done:
2154         spin_unlock(&session->frwd_lock);
2155 }
2156
2157 static void iscsi_prep_abort_task_pdu(struct iscsi_task *task,
2158                                       struct iscsi_tm *hdr)
2159 {
2160         memset(hdr, 0, sizeof(*hdr));
2161         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2162         hdr->flags = ISCSI_TM_FUNC_ABORT_TASK & ISCSI_FLAG_TM_FUNC_MASK;
2163         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2164         hdr->lun = task->lun;
2165         hdr->rtt = task->hdr_itt;
2166         hdr->refcmdsn = task->cmdsn;
2167 }
2168
2169 int iscsi_eh_abort(struct scsi_cmnd *sc)
2170 {
2171         struct iscsi_cls_session *cls_session;
2172         struct iscsi_session *session;
2173         struct iscsi_conn *conn;
2174         struct iscsi_task *task;
2175         struct iscsi_tm *hdr;
2176         int age;
2177
2178         cls_session = starget_to_session(scsi_target(sc->device));
2179         session = cls_session->dd_data;
2180
2181         ISCSI_DBG_EH(session, "aborting sc %p\n", sc);
2182
2183         mutex_lock(&session->eh_mutex);
2184         spin_lock_bh(&session->frwd_lock);
2185         /*
2186          * if session was ISCSI_STATE_IN_RECOVERY then we may not have
2187          * got the command.
2188          */
2189         if (!sc->SCp.ptr) {
2190                 ISCSI_DBG_EH(session, "sc never reached iscsi layer or "
2191                                       "it completed.\n");
2192                 spin_unlock_bh(&session->frwd_lock);
2193                 mutex_unlock(&session->eh_mutex);
2194                 return SUCCESS;
2195         }
2196
2197         /*
2198          * If we are not logged in or we have started a new session
2199          * then let the host reset code handle this
2200          */
2201         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN ||
2202             sc->SCp.phase != session->age) {
2203                 spin_unlock_bh(&session->frwd_lock);
2204                 mutex_unlock(&session->eh_mutex);
2205                 ISCSI_DBG_EH(session, "failing abort due to dropped "
2206                                   "session.\n");
2207                 return FAILED;
2208         }
2209
2210         conn = session->leadconn;
2211         conn->eh_abort_cnt++;
2212         age = session->age;
2213
2214         task = (struct iscsi_task *)sc->SCp.ptr;
2215         ISCSI_DBG_EH(session, "aborting [sc %p itt 0x%x]\n",
2216                      sc, task->itt);
2217
2218         /* task completed before time out */
2219         if (!task->sc) {
2220                 ISCSI_DBG_EH(session, "sc completed while abort in progress\n");
2221                 goto success;
2222         }
2223
2224         if (task->state == ISCSI_TASK_PENDING) {
2225                 fail_scsi_task(task, DID_ABORT);
2226                 goto success;
2227         }
2228
2229         /* only have one tmf outstanding at a time */
2230         if (conn->tmf_state != TMF_INITIAL)
2231                 goto failed;
2232         conn->tmf_state = TMF_QUEUED;
2233
2234         hdr = &conn->tmhdr;
2235         iscsi_prep_abort_task_pdu(task, hdr);
2236
2237         if (iscsi_exec_task_mgmt_fn(conn, hdr, age, session->abort_timeout))
2238                 goto failed;
2239
2240         switch (conn->tmf_state) {
2241         case TMF_SUCCESS:
2242                 spin_unlock_bh(&session->frwd_lock);
2243                 /*
2244                  * stop tx side incase the target had sent a abort rsp but
2245                  * the initiator was still writing out data.
2246                  */
2247                 iscsi_suspend_tx(conn);
2248                 /*
2249                  * we do not stop the recv side because targets have been
2250                  * good and have never sent us a successful tmf response
2251                  * then sent more data for the cmd.
2252                  */
2253                 spin_lock_bh(&session->frwd_lock);
2254                 fail_scsi_task(task, DID_ABORT);
2255                 conn->tmf_state = TMF_INITIAL;
2256                 memset(hdr, 0, sizeof(*hdr));
2257                 spin_unlock_bh(&session->frwd_lock);
2258                 iscsi_start_tx(conn);
2259                 goto success_unlocked;
2260         case TMF_TIMEDOUT:
2261                 spin_unlock_bh(&session->frwd_lock);
2262                 iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2263                 goto failed_unlocked;
2264         case TMF_NOT_FOUND:
2265                 if (!sc->SCp.ptr) {
2266                         conn->tmf_state = TMF_INITIAL;
2267                         memset(hdr, 0, sizeof(*hdr));
2268                         /* task completed before tmf abort response */
2269                         ISCSI_DBG_EH(session, "sc completed while abort in "
2270                                               "progress\n");
2271                         goto success;
2272                 }
2273                 /* fall through */
2274         default:
2275                 conn->tmf_state = TMF_INITIAL;
2276                 goto failed;
2277         }
2278
2279 success:
2280         spin_unlock_bh(&session->frwd_lock);
2281 success_unlocked:
2282         ISCSI_DBG_EH(session, "abort success [sc %p itt 0x%x]\n",
2283                      sc, task->itt);
2284         mutex_unlock(&session->eh_mutex);
2285         return SUCCESS;
2286
2287 failed:
2288         spin_unlock_bh(&session->frwd_lock);
2289 failed_unlocked:
2290         ISCSI_DBG_EH(session, "abort failed [sc %p itt 0x%x]\n", sc,
2291                      task ? task->itt : 0);
2292         mutex_unlock(&session->eh_mutex);
2293         return FAILED;
2294 }
2295 EXPORT_SYMBOL_GPL(iscsi_eh_abort);
2296
2297 static void iscsi_prep_lun_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
2298 {
2299         memset(hdr, 0, sizeof(*hdr));
2300         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2301         hdr->flags = ISCSI_TM_FUNC_LOGICAL_UNIT_RESET & ISCSI_FLAG_TM_FUNC_MASK;
2302         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2303         int_to_scsilun(sc->device->lun, &hdr->lun);
2304         hdr->rtt = RESERVED_ITT;
2305 }
2306
2307 int iscsi_eh_device_reset(struct scsi_cmnd *sc)
2308 {
2309         struct iscsi_cls_session *cls_session;
2310         struct iscsi_session *session;
2311         struct iscsi_conn *conn;
2312         struct iscsi_tm *hdr;
2313         int rc = FAILED;
2314
2315         cls_session = starget_to_session(scsi_target(sc->device));
2316         session = cls_session->dd_data;
2317
2318         ISCSI_DBG_EH(session, "LU Reset [sc %p lun %llu]\n", sc,
2319                      sc->device->lun);
2320
2321         mutex_lock(&session->eh_mutex);
2322         spin_lock_bh(&session->frwd_lock);
2323         /*
2324          * Just check if we are not logged in. We cannot check for
2325          * the phase because the reset could come from a ioctl.
2326          */
2327         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
2328                 goto unlock;
2329         conn = session->leadconn;
2330
2331         /* only have one tmf outstanding at a time */
2332         if (conn->tmf_state != TMF_INITIAL)
2333                 goto unlock;
2334         conn->tmf_state = TMF_QUEUED;
2335
2336         hdr = &conn->tmhdr;
2337         iscsi_prep_lun_reset_pdu(sc, hdr);
2338
2339         if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
2340                                     session->lu_reset_timeout)) {
2341                 rc = FAILED;
2342                 goto unlock;
2343         }
2344
2345         switch (conn->tmf_state) {
2346         case TMF_SUCCESS:
2347                 break;
2348         case TMF_TIMEDOUT:
2349                 spin_unlock_bh(&session->frwd_lock);
2350                 iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2351                 goto done;
2352         default:
2353                 conn->tmf_state = TMF_INITIAL;
2354                 goto unlock;
2355         }
2356
2357         rc = SUCCESS;
2358         spin_unlock_bh(&session->frwd_lock);
2359
2360         iscsi_suspend_tx(conn);
2361
2362         spin_lock_bh(&session->frwd_lock);
2363         memset(hdr, 0, sizeof(*hdr));
2364         fail_scsi_tasks(conn, sc->device->lun, DID_ERROR);
2365         conn->tmf_state = TMF_INITIAL;
2366         spin_unlock_bh(&session->frwd_lock);
2367
2368         iscsi_start_tx(conn);
2369         goto done;
2370
2371 unlock:
2372         spin_unlock_bh(&session->frwd_lock);
2373 done:
2374         ISCSI_DBG_EH(session, "dev reset result = %s\n",
2375                      rc == SUCCESS ? "SUCCESS" : "FAILED");
2376         mutex_unlock(&session->eh_mutex);
2377         return rc;
2378 }
2379 EXPORT_SYMBOL_GPL(iscsi_eh_device_reset);
2380
2381 void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
2382 {
2383         struct iscsi_session *session = cls_session->dd_data;
2384
2385         spin_lock_bh(&session->frwd_lock);
2386         if (session->state != ISCSI_STATE_LOGGED_IN) {
2387                 session->state = ISCSI_STATE_RECOVERY_FAILED;
2388                 if (session->leadconn)
2389                         wake_up(&session->leadconn->ehwait);
2390         }
2391         spin_unlock_bh(&session->frwd_lock);
2392 }
2393 EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
2394
2395 /**
2396  * iscsi_eh_session_reset - drop session and attempt relogin
2397  * @sc: scsi command
2398  *
2399  * This function will wait for a relogin, session termination from
2400  * userspace, or a recovery/replacement timeout.
2401  */
2402 int iscsi_eh_session_reset(struct scsi_cmnd *sc)
2403 {
2404         struct iscsi_cls_session *cls_session;
2405         struct iscsi_session *session;
2406         struct iscsi_conn *conn;
2407
2408         cls_session = starget_to_session(scsi_target(sc->device));
2409         session = cls_session->dd_data;
2410         conn = session->leadconn;
2411
2412         mutex_lock(&session->eh_mutex);
2413         spin_lock_bh(&session->frwd_lock);
2414         if (session->state == ISCSI_STATE_TERMINATE) {
2415 failed:
2416                 ISCSI_DBG_EH(session,
2417                              "failing session reset: Could not log back into "
2418                              "%s, %s [age %d]\n", session->targetname,
2419                              conn->persistent_address, session->age);
2420                 spin_unlock_bh(&session->frwd_lock);
2421                 mutex_unlock(&session->eh_mutex);
2422                 return FAILED;
2423         }
2424
2425         spin_unlock_bh(&session->frwd_lock);
2426         mutex_unlock(&session->eh_mutex);
2427         /*
2428          * we drop the lock here but the leadconn cannot be destoyed while
2429          * we are in the scsi eh
2430          */
2431         iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2432
2433         ISCSI_DBG_EH(session, "wait for relogin\n");
2434         wait_event_interruptible(conn->ehwait,
2435                                  session->state == ISCSI_STATE_TERMINATE ||
2436                                  session->state == ISCSI_STATE_LOGGED_IN ||
2437                                  session->state == ISCSI_STATE_RECOVERY_FAILED);
2438         if (signal_pending(current))
2439                 flush_signals(current);
2440
2441         mutex_lock(&session->eh_mutex);
2442         spin_lock_bh(&session->frwd_lock);
2443         if (session->state == ISCSI_STATE_LOGGED_IN) {
2444                 ISCSI_DBG_EH(session,
2445                              "session reset succeeded for %s,%s\n",
2446                              session->targetname, conn->persistent_address);
2447         } else
2448                 goto failed;
2449         spin_unlock_bh(&session->frwd_lock);
2450         mutex_unlock(&session->eh_mutex);
2451         return SUCCESS;
2452 }
2453 EXPORT_SYMBOL_GPL(iscsi_eh_session_reset);
2454
2455 static void iscsi_prep_tgt_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
2456 {
2457         memset(hdr, 0, sizeof(*hdr));
2458         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
2459         hdr->flags = ISCSI_TM_FUNC_TARGET_WARM_RESET & ISCSI_FLAG_TM_FUNC_MASK;
2460         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
2461         hdr->rtt = RESERVED_ITT;
2462 }
2463
2464 /**
2465  * iscsi_eh_target_reset - reset target
2466  * @sc: scsi command
2467  *
2468  * This will attempt to send a warm target reset.
2469  */
2470 static int iscsi_eh_target_reset(struct scsi_cmnd *sc)
2471 {
2472         struct iscsi_cls_session *cls_session;
2473         struct iscsi_session *session;
2474         struct iscsi_conn *conn;
2475         struct iscsi_tm *hdr;
2476         int rc = FAILED;
2477
2478         cls_session = starget_to_session(scsi_target(sc->device));
2479         session = cls_session->dd_data;
2480
2481         ISCSI_DBG_EH(session, "tgt Reset [sc %p tgt %s]\n", sc,
2482                      session->targetname);
2483
2484         mutex_lock(&session->eh_mutex);
2485         spin_lock_bh(&session->frwd_lock);
2486         /*
2487          * Just check if we are not logged in. We cannot check for
2488          * the phase because the reset could come from a ioctl.
2489          */
2490         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
2491                 goto unlock;
2492         conn = session->leadconn;
2493
2494         /* only have one tmf outstanding at a time */
2495         if (conn->tmf_state != TMF_INITIAL)
2496                 goto unlock;
2497         conn->tmf_state = TMF_QUEUED;
2498
2499         hdr = &conn->tmhdr;
2500         iscsi_prep_tgt_reset_pdu(sc, hdr);
2501
2502         if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
2503                                     session->tgt_reset_timeout)) {
2504                 rc = FAILED;
2505                 goto unlock;
2506         }
2507
2508         switch (conn->tmf_state) {
2509         case TMF_SUCCESS:
2510                 break;
2511         case TMF_TIMEDOUT:
2512                 spin_unlock_bh(&session->frwd_lock);
2513                 iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
2514                 goto done;
2515         default:
2516                 conn->tmf_state = TMF_INITIAL;
2517                 goto unlock;
2518         }
2519
2520         rc = SUCCESS;
2521         spin_unlock_bh(&session->frwd_lock);
2522
2523         iscsi_suspend_tx(conn);
2524
2525         spin_lock_bh(&session->frwd_lock);
2526         memset(hdr, 0, sizeof(*hdr));
2527         fail_scsi_tasks(conn, -1, DID_ERROR);
2528         conn->tmf_state = TMF_INITIAL;
2529         spin_unlock_bh(&session->frwd_lock);
2530
2531         iscsi_start_tx(conn);
2532         goto done;
2533
2534 unlock:
2535         spin_unlock_bh(&session->frwd_lock);
2536 done:
2537         ISCSI_DBG_EH(session, "tgt %s reset result = %s\n", session->targetname,
2538                      rc == SUCCESS ? "SUCCESS" : "FAILED");
2539         mutex_unlock(&session->eh_mutex);
2540         return rc;
2541 }
2542
2543 /**
2544  * iscsi_eh_recover_target - reset target and possibly the session
2545  * @sc: scsi command
2546  *
2547  * This will attempt to send a warm target reset. If that fails,
2548  * we will escalate to ERL0 session recovery.
2549  */
2550 int iscsi_eh_recover_target(struct scsi_cmnd *sc)
2551 {
2552         int rc;
2553
2554         rc = iscsi_eh_target_reset(sc);
2555         if (rc == FAILED)
2556                 rc = iscsi_eh_session_reset(sc);
2557         return rc;
2558 }
2559 EXPORT_SYMBOL_GPL(iscsi_eh_recover_target);
2560
2561 /*
2562  * Pre-allocate a pool of @max items of @item_size. By default, the pool
2563  * should be accessed via kfifo_{get,put} on q->queue.
2564  * Optionally, the caller can obtain the array of object pointers
2565  * by passing in a non-NULL @items pointer
2566  */
2567 int
2568 iscsi_pool_init(struct iscsi_pool *q, int max, void ***items, int item_size)
2569 {
2570         int i, num_arrays = 1;
2571
2572         memset(q, 0, sizeof(*q));
2573
2574         q->max = max;
2575
2576         /* If the user passed an items pointer, he wants a copy of
2577          * the array. */
2578         if (items)
2579                 num_arrays++;
2580         q->pool = kvcalloc(num_arrays * max, sizeof(void *), GFP_KERNEL);
2581         if (q->pool == NULL)
2582                 return -ENOMEM;
2583
2584         kfifo_init(&q->queue, (void*)q->pool, max * sizeof(void*));
2585
2586         for (i = 0; i < max; i++) {
2587                 q->pool[i] = kzalloc(item_size, GFP_KERNEL);
2588                 if (q->pool[i] == NULL) {
2589                         q->max = i;
2590                         goto enomem;
2591                 }
2592                 kfifo_in(&q->queue, (void*)&q->pool[i], sizeof(void*));
2593         }
2594
2595         if (items) {
2596                 *items = q->pool + max;
2597                 memcpy(*items, q->pool, max * sizeof(void *));
2598         }
2599
2600         return 0;
2601
2602 enomem:
2603         iscsi_pool_free(q);
2604         return -ENOMEM;
2605 }
2606 EXPORT_SYMBOL_GPL(iscsi_pool_init);
2607
2608 void iscsi_pool_free(struct iscsi_pool *q)
2609 {
2610         int i;
2611
2612         for (i = 0; i < q->max; i++)
2613                 kfree(q->pool[i]);
2614         kvfree(q->pool);
2615 }
2616 EXPORT_SYMBOL_GPL(iscsi_pool_free);
2617
2618 /**
2619  * iscsi_host_add - add host to system
2620  * @shost: scsi host
2621  * @pdev: parent device
2622  *
2623  * This should be called by partial offload and software iscsi drivers
2624  * to add a host to the system.
2625  */
2626 int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev)
2627 {
2628         if (!shost->can_queue)
2629                 shost->can_queue = ISCSI_DEF_XMIT_CMDS_MAX;
2630
2631         if (!shost->cmd_per_lun)
2632                 shost->cmd_per_lun = ISCSI_DEF_CMD_PER_LUN;
2633
2634         return scsi_add_host(shost, pdev);
2635 }
2636 EXPORT_SYMBOL_GPL(iscsi_host_add);
2637
2638 /**
2639  * iscsi_host_alloc - allocate a host and driver data
2640  * @sht: scsi host template
2641  * @dd_data_size: driver host data size
2642  * @xmit_can_sleep: bool indicating if LLD will queue IO from a work queue
2643  *
2644  * This should be called by partial offload and software iscsi drivers.
2645  * To access the driver specific memory use the iscsi_host_priv() macro.
2646  */
2647 struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
2648                                    int dd_data_size, bool xmit_can_sleep)
2649 {
2650         struct Scsi_Host *shost;
2651         struct iscsi_host *ihost;
2652
2653         shost = scsi_host_alloc(sht, sizeof(struct iscsi_host) + dd_data_size);
2654         if (!shost)
2655                 return NULL;
2656         ihost = shost_priv(shost);
2657
2658         if (xmit_can_sleep) {
2659                 snprintf(ihost->workq_name, sizeof(ihost->workq_name),
2660                         "iscsi_q_%d", shost->host_no);
2661                 ihost->workq = create_singlethread_workqueue(ihost->workq_name);
2662                 if (!ihost->workq)
2663                         goto free_host;
2664         }
2665
2666         spin_lock_init(&ihost->lock);
2667         ihost->state = ISCSI_HOST_SETUP;
2668         ihost->num_sessions = 0;
2669         init_waitqueue_head(&ihost->session_removal_wq);
2670         return shost;
2671
2672 free_host:
2673         scsi_host_put(shost);
2674         return NULL;
2675 }
2676 EXPORT_SYMBOL_GPL(iscsi_host_alloc);
2677
2678 static void iscsi_notify_host_removed(struct iscsi_cls_session *cls_session)
2679 {
2680         iscsi_session_failure(cls_session->dd_data, ISCSI_ERR_INVALID_HOST);
2681 }
2682
2683 /**
2684  * iscsi_host_remove - remove host and sessions
2685  * @shost: scsi host
2686  *
2687  * If there are any sessions left, this will initiate the removal and wait
2688  * for the completion.
2689  */
2690 void iscsi_host_remove(struct Scsi_Host *shost)
2691 {
2692         struct iscsi_host *ihost = shost_priv(shost);
2693         unsigned long flags;
2694
2695         spin_lock_irqsave(&ihost->lock, flags);
2696         ihost->state = ISCSI_HOST_REMOVED;
2697         spin_unlock_irqrestore(&ihost->lock, flags);
2698
2699         iscsi_host_for_each_session(shost, iscsi_notify_host_removed);
2700         wait_event_interruptible(ihost->session_removal_wq,
2701                                  ihost->num_sessions == 0);
2702         if (signal_pending(current))
2703                 flush_signals(current);
2704
2705         scsi_remove_host(shost);
2706         if (ihost->workq)
2707                 destroy_workqueue(ihost->workq);
2708 }
2709 EXPORT_SYMBOL_GPL(iscsi_host_remove);
2710
2711 void iscsi_host_free(struct Scsi_Host *shost)
2712 {
2713         struct iscsi_host *ihost = shost_priv(shost);
2714
2715         kfree(ihost->netdev);
2716         kfree(ihost->hwaddress);
2717         kfree(ihost->initiatorname);
2718         scsi_host_put(shost);
2719 }
2720 EXPORT_SYMBOL_GPL(iscsi_host_free);
2721
2722 static void iscsi_host_dec_session_cnt(struct Scsi_Host *shost)
2723 {
2724         struct iscsi_host *ihost = shost_priv(shost);
2725         unsigned long flags;
2726
2727         shost = scsi_host_get(shost);
2728         if (!shost) {
2729                 printk(KERN_ERR "Invalid state. Cannot notify host removal "
2730                       "of session teardown event because host already "
2731                       "removed.\n");
2732                 return;
2733         }
2734
2735         spin_lock_irqsave(&ihost->lock, flags);
2736         ihost->num_sessions--;
2737         if (ihost->num_sessions == 0)
2738                 wake_up(&ihost->session_removal_wq);
2739         spin_unlock_irqrestore(&ihost->lock, flags);
2740         scsi_host_put(shost);
2741 }
2742
2743 /**
2744  * iscsi_session_setup - create iscsi cls session and host and session
2745  * @iscsit: iscsi transport template
2746  * @shost: scsi host
2747  * @cmds_max: session can queue
2748  * @dd_size: private driver data size, added to session allocation size
2749  * @cmd_task_size: LLD task private data size
2750  * @initial_cmdsn: initial CmdSN
2751  * @id: target ID to add to this session
2752  *
2753  * This can be used by software iscsi_transports that allocate
2754  * a session per scsi host.
2755  *
2756  * Callers should set cmds_max to the largest total numer (mgmt + scsi) of
2757  * tasks they support. The iscsi layer reserves ISCSI_MGMT_CMDS_MAX tasks
2758  * for nop handling and login/logout requests.
2759  */
2760 struct iscsi_cls_session *
2761 iscsi_session_setup(struct iscsi_transport *iscsit, struct Scsi_Host *shost,
2762                     uint16_t cmds_max, int dd_size, int cmd_task_size,
2763                     uint32_t initial_cmdsn, unsigned int id)
2764 {
2765         struct iscsi_host *ihost = shost_priv(shost);
2766         struct iscsi_session *session;
2767         struct iscsi_cls_session *cls_session;
2768         int cmd_i, scsi_cmds, total_cmds = cmds_max;
2769         unsigned long flags;
2770
2771         spin_lock_irqsave(&ihost->lock, flags);
2772         if (ihost->state == ISCSI_HOST_REMOVED) {
2773                 spin_unlock_irqrestore(&ihost->lock, flags);
2774                 return NULL;
2775         }
2776         ihost->num_sessions++;
2777         spin_unlock_irqrestore(&ihost->lock, flags);
2778
2779         if (!total_cmds)
2780                 total_cmds = ISCSI_DEF_XMIT_CMDS_MAX;
2781         /*
2782          * The iscsi layer needs some tasks for nop handling and tmfs,
2783          * so the cmds_max must at least be greater than ISCSI_MGMT_CMDS_MAX
2784          * + 1 command for scsi IO.
2785          */
2786         if (total_cmds < ISCSI_TOTAL_CMDS_MIN) {
2787                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2788                        "must be a power of two that is at least %d.\n",
2789                        total_cmds, ISCSI_TOTAL_CMDS_MIN);
2790                 goto dec_session_count;
2791         }
2792
2793         if (total_cmds > ISCSI_TOTAL_CMDS_MAX) {
2794                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2795                        "must be a power of 2 less than or equal to %d.\n",
2796                        cmds_max, ISCSI_TOTAL_CMDS_MAX);
2797                 total_cmds = ISCSI_TOTAL_CMDS_MAX;
2798         }
2799
2800         if (!is_power_of_2(total_cmds)) {
2801                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2802                        "must be a power of 2.\n", total_cmds);
2803                 total_cmds = rounddown_pow_of_two(total_cmds);
2804                 if (total_cmds < ISCSI_TOTAL_CMDS_MIN)
2805                         return NULL;
2806                 printk(KERN_INFO "iscsi: Rounding can_queue to %d.\n",
2807                        total_cmds);
2808         }
2809         scsi_cmds = total_cmds - ISCSI_MGMT_CMDS_MAX;
2810
2811         cls_session = iscsi_alloc_session(shost, iscsit,
2812                                           sizeof(struct iscsi_session) +
2813                                           dd_size);
2814         if (!cls_session)
2815                 goto dec_session_count;
2816         session = cls_session->dd_data;
2817         session->cls_session = cls_session;
2818         session->host = shost;
2819         session->state = ISCSI_STATE_FREE;
2820         session->fast_abort = 1;
2821         session->tgt_reset_timeout = 30;
2822         session->lu_reset_timeout = 15;
2823         session->abort_timeout = 10;
2824         session->scsi_cmds_max = scsi_cmds;
2825         session->cmds_max = total_cmds;
2826         session->queued_cmdsn = session->cmdsn = initial_cmdsn;
2827         session->exp_cmdsn = initial_cmdsn + 1;
2828         session->max_cmdsn = initial_cmdsn + 1;
2829         session->max_r2t = 1;
2830         session->tt = iscsit;
2831         session->dd_data = cls_session->dd_data + sizeof(*session);
2832
2833         mutex_init(&session->eh_mutex);
2834         spin_lock_init(&session->frwd_lock);
2835         spin_lock_init(&session->back_lock);
2836
2837         /* initialize SCSI PDU commands pool */
2838         if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
2839                             (void***)&session->cmds,
2840                             cmd_task_size + sizeof(struct iscsi_task)))
2841                 goto cmdpool_alloc_fail;
2842
2843         /* pre-format cmds pool with ITT */
2844         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
2845                 struct iscsi_task *task = session->cmds[cmd_i];
2846
2847                 if (cmd_task_size)
2848                         task->dd_data = &task[1];
2849                 task->itt = cmd_i;
2850                 task->state = ISCSI_TASK_FREE;
2851                 INIT_LIST_HEAD(&task->running);
2852         }
2853
2854         if (!try_module_get(iscsit->owner))
2855                 goto module_get_fail;
2856
2857         if (iscsi_add_session(cls_session, id))
2858                 goto cls_session_fail;
2859
2860         return cls_session;
2861
2862 cls_session_fail:
2863         module_put(iscsit->owner);
2864 module_get_fail:
2865         iscsi_pool_free(&session->cmdpool);
2866 cmdpool_alloc_fail:
2867         iscsi_free_session(cls_session);
2868 dec_session_count:
2869         iscsi_host_dec_session_cnt(shost);
2870         return NULL;
2871 }
2872 EXPORT_SYMBOL_GPL(iscsi_session_setup);
2873
2874 /**
2875  * iscsi_session_teardown - destroy session, host, and cls_session
2876  * @cls_session: iscsi session
2877  */
2878 void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
2879 {
2880         struct iscsi_session *session = cls_session->dd_data;
2881         struct module *owner = cls_session->transport->owner;
2882         struct Scsi_Host *shost = session->host;
2883
2884         iscsi_pool_free(&session->cmdpool);
2885
2886         iscsi_remove_session(cls_session);
2887
2888         kfree(session->password);
2889         kfree(session->password_in);
2890         kfree(session->username);
2891         kfree(session->username_in);
2892         kfree(session->targetname);
2893         kfree(session->targetalias);
2894         kfree(session->initiatorname);
2895         kfree(session->boot_root);
2896         kfree(session->boot_nic);
2897         kfree(session->boot_target);
2898         kfree(session->ifacename);
2899         kfree(session->portal_type);
2900         kfree(session->discovery_parent_type);
2901
2902         iscsi_free_session(cls_session);
2903
2904         iscsi_host_dec_session_cnt(shost);
2905         module_put(owner);
2906 }
2907 EXPORT_SYMBOL_GPL(iscsi_session_teardown);
2908
2909 /**
2910  * iscsi_conn_setup - create iscsi_cls_conn and iscsi_conn
2911  * @cls_session: iscsi_cls_session
2912  * @dd_size: private driver data size
2913  * @conn_idx: cid
2914  */
2915 struct iscsi_cls_conn *
2916 iscsi_conn_setup(struct iscsi_cls_session *cls_session, int dd_size,
2917                  uint32_t conn_idx)
2918 {
2919         struct iscsi_session *session = cls_session->dd_data;
2920         struct iscsi_conn *conn;
2921         struct iscsi_cls_conn *cls_conn;
2922         char *data;
2923
2924         cls_conn = iscsi_create_conn(cls_session, sizeof(*conn) + dd_size,
2925                                      conn_idx);
2926         if (!cls_conn)
2927                 return NULL;
2928         conn = cls_conn->dd_data;
2929         memset(conn, 0, sizeof(*conn) + dd_size);
2930
2931         conn->dd_data = cls_conn->dd_data + sizeof(*conn);
2932         conn->session = session;
2933         conn->cls_conn = cls_conn;
2934         conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
2935         conn->id = conn_idx;
2936         conn->exp_statsn = 0;
2937         conn->tmf_state = TMF_INITIAL;
2938
2939         timer_setup(&conn->transport_timer, iscsi_check_transport_timeouts, 0);
2940
2941         INIT_LIST_HEAD(&conn->mgmtqueue);
2942         INIT_LIST_HEAD(&conn->cmdqueue);
2943         INIT_LIST_HEAD(&conn->requeue);
2944         spin_lock_init(&conn->taskqueuelock);
2945         INIT_WORK(&conn->xmitwork, iscsi_xmitworker);
2946
2947         /* allocate login_task used for the login/text sequences */
2948         spin_lock_bh(&session->frwd_lock);
2949         if (!kfifo_out(&session->cmdpool.queue,
2950                          (void*)&conn->login_task,
2951                          sizeof(void*))) {
2952                 spin_unlock_bh(&session->frwd_lock);
2953                 goto login_task_alloc_fail;
2954         }
2955         spin_unlock_bh(&session->frwd_lock);
2956
2957         data = (char *) __get_free_pages(GFP_KERNEL,
2958                                          get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
2959         if (!data)
2960                 goto login_task_data_alloc_fail;
2961         conn->login_task->data = conn->data = data;
2962
2963         timer_setup(&conn->tmf_timer, iscsi_tmf_timedout, 0);
2964         init_waitqueue_head(&conn->ehwait);
2965
2966         return cls_conn;
2967
2968 login_task_data_alloc_fail:
2969         kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
2970                     sizeof(void*));
2971 login_task_alloc_fail:
2972         iscsi_destroy_conn(cls_conn);
2973         return NULL;
2974 }
2975 EXPORT_SYMBOL_GPL(iscsi_conn_setup);
2976
2977 /**
2978  * iscsi_conn_teardown - teardown iscsi connection
2979  * @cls_conn: iscsi class connection
2980  *
2981  * TODO: we may need to make this into a two step process
2982  * like scsi-mls remove + put host
2983  */
2984 void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
2985 {
2986         struct iscsi_conn *conn = cls_conn->dd_data;
2987         struct iscsi_session *session = conn->session;
2988
2989         del_timer_sync(&conn->transport_timer);
2990
2991         mutex_lock(&session->eh_mutex);
2992         spin_lock_bh(&session->frwd_lock);
2993         conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
2994         if (session->leadconn == conn) {
2995                 /*
2996                  * leading connection? then give up on recovery.
2997                  */
2998                 session->state = ISCSI_STATE_TERMINATE;
2999                 wake_up(&conn->ehwait);
3000         }
3001         spin_unlock_bh(&session->frwd_lock);
3002
3003         /* flush queued up work because we free the connection below */
3004         iscsi_suspend_tx(conn);
3005
3006         spin_lock_bh(&session->frwd_lock);
3007         free_pages((unsigned long) conn->data,
3008                    get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
3009         kfree(conn->persistent_address);
3010         kfree(conn->local_ipaddr);
3011         /* regular RX path uses back_lock */
3012         spin_lock_bh(&session->back_lock);
3013         kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
3014                     sizeof(void*));
3015         spin_unlock_bh(&session->back_lock);
3016         if (session->leadconn == conn)
3017                 session->leadconn = NULL;
3018         spin_unlock_bh(&session->frwd_lock);
3019         mutex_unlock(&session->eh_mutex);
3020
3021         iscsi_destroy_conn(cls_conn);
3022 }
3023 EXPORT_SYMBOL_GPL(iscsi_conn_teardown);
3024
3025 int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
3026 {
3027         struct iscsi_conn *conn = cls_conn->dd_data;
3028         struct iscsi_session *session = conn->session;
3029
3030         if (!session) {
3031                 iscsi_conn_printk(KERN_ERR, conn,
3032                                   "can't start unbound connection\n");
3033                 return -EPERM;
3034         }
3035
3036         if ((session->imm_data_en || !session->initial_r2t_en) &&
3037              session->first_burst > session->max_burst) {
3038                 iscsi_conn_printk(KERN_INFO, conn, "invalid burst lengths: "
3039                                   "first_burst %d max_burst %d\n",
3040                                   session->first_burst, session->max_burst);
3041                 return -EINVAL;
3042         }
3043
3044         if (conn->ping_timeout && !conn->recv_timeout) {
3045                 iscsi_conn_printk(KERN_ERR, conn, "invalid recv timeout of "
3046                                   "zero. Using 5 seconds\n.");
3047                 conn->recv_timeout = 5;
3048         }
3049
3050         if (conn->recv_timeout && !conn->ping_timeout) {
3051                 iscsi_conn_printk(KERN_ERR, conn, "invalid ping timeout of "
3052                                   "zero. Using 5 seconds.\n");
3053                 conn->ping_timeout = 5;
3054         }
3055
3056         spin_lock_bh(&session->frwd_lock);
3057         conn->c_stage = ISCSI_CONN_STARTED;
3058         session->state = ISCSI_STATE_LOGGED_IN;
3059         session->queued_cmdsn = session->cmdsn;
3060
3061         conn->last_recv = jiffies;
3062         conn->last_ping = jiffies;
3063         if (conn->recv_timeout && conn->ping_timeout)
3064                 mod_timer(&conn->transport_timer,
3065                           jiffies + (conn->recv_timeout * HZ));
3066
3067         switch(conn->stop_stage) {
3068         case STOP_CONN_RECOVER:
3069                 /*
3070                  * unblock eh_abort() if it is blocked. re-try all
3071                  * commands after successful recovery
3072                  */
3073                 conn->stop_stage = 0;
3074                 conn->tmf_state = TMF_INITIAL;
3075                 session->age++;
3076                 if (session->age == 16)
3077                         session->age = 0;
3078                 break;
3079         case STOP_CONN_TERM:
3080                 conn->stop_stage = 0;
3081                 break;
3082         default:
3083                 break;
3084         }
3085         spin_unlock_bh(&session->frwd_lock);
3086
3087         iscsi_unblock_session(session->cls_session);
3088         wake_up(&conn->ehwait);
3089         return 0;
3090 }
3091 EXPORT_SYMBOL_GPL(iscsi_conn_start);
3092
3093 static void
3094 fail_mgmt_tasks(struct iscsi_session *session, struct iscsi_conn *conn)
3095 {
3096         struct iscsi_task *task;
3097         int i, state;
3098
3099         for (i = 0; i < conn->session->cmds_max; i++) {
3100                 task = conn->session->cmds[i];
3101                 if (task->sc)
3102                         continue;
3103
3104                 if (task->state == ISCSI_TASK_FREE)
3105                         continue;
3106
3107                 ISCSI_DBG_SESSION(conn->session,
3108                                   "failing mgmt itt 0x%x state %d\n",
3109                                   task->itt, task->state);
3110                 state = ISCSI_TASK_ABRT_SESS_RECOV;
3111                 if (task->state == ISCSI_TASK_PENDING)
3112                         state = ISCSI_TASK_COMPLETED;
3113                 iscsi_complete_task(task, state);
3114
3115         }
3116 }
3117
3118 static void iscsi_start_session_recovery(struct iscsi_session *session,
3119                                          struct iscsi_conn *conn, int flag)
3120 {
3121         int old_stop_stage;
3122
3123         mutex_lock(&session->eh_mutex);
3124         spin_lock_bh(&session->frwd_lock);
3125         if (conn->stop_stage == STOP_CONN_TERM) {
3126                 spin_unlock_bh(&session->frwd_lock);
3127                 mutex_unlock(&session->eh_mutex);
3128                 return;
3129         }
3130
3131         /*
3132          * When this is called for the in_login state, we only want to clean
3133          * up the login task and connection. We do not need to block and set
3134          * the recovery state again
3135          */
3136         if (flag == STOP_CONN_TERM)
3137                 session->state = ISCSI_STATE_TERMINATE;
3138         else if (conn->stop_stage != STOP_CONN_RECOVER)
3139                 session->state = ISCSI_STATE_IN_RECOVERY;
3140
3141         old_stop_stage = conn->stop_stage;
3142         conn->stop_stage = flag;
3143         spin_unlock_bh(&session->frwd_lock);
3144
3145         del_timer_sync(&conn->transport_timer);
3146         iscsi_suspend_tx(conn);
3147
3148         spin_lock_bh(&session->frwd_lock);
3149         conn->c_stage = ISCSI_CONN_STOPPED;
3150         spin_unlock_bh(&session->frwd_lock);
3151
3152         /*
3153          * for connection level recovery we should not calculate
3154          * header digest. conn->hdr_size used for optimization
3155          * in hdr_extract() and will be re-negotiated at
3156          * set_param() time.
3157          */
3158         if (flag == STOP_CONN_RECOVER) {
3159                 conn->hdrdgst_en = 0;
3160                 conn->datadgst_en = 0;
3161                 if (session->state == ISCSI_STATE_IN_RECOVERY &&
3162                     old_stop_stage != STOP_CONN_RECOVER) {
3163                         ISCSI_DBG_SESSION(session, "blocking session\n");
3164                         iscsi_block_session(session->cls_session);
3165                 }
3166         }
3167
3168         /*
3169          * flush queues.
3170          */
3171         spin_lock_bh(&session->frwd_lock);
3172         fail_scsi_tasks(conn, -1, DID_TRANSPORT_DISRUPTED);
3173         fail_mgmt_tasks(session, conn);
3174         memset(&conn->tmhdr, 0, sizeof(conn->tmhdr));
3175         spin_unlock_bh(&session->frwd_lock);
3176         mutex_unlock(&session->eh_mutex);
3177 }
3178
3179 void iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
3180 {
3181         struct iscsi_conn *conn = cls_conn->dd_data;
3182         struct iscsi_session *session = conn->session;
3183
3184         switch (flag) {
3185         case STOP_CONN_RECOVER:
3186         case STOP_CONN_TERM:
3187                 iscsi_start_session_recovery(session, conn, flag);
3188                 break;
3189         default:
3190                 iscsi_conn_printk(KERN_ERR, conn,
3191                                   "invalid stop flag %d\n", flag);
3192         }
3193 }
3194 EXPORT_SYMBOL_GPL(iscsi_conn_stop);
3195
3196 int iscsi_conn_bind(struct iscsi_cls_session *cls_session,
3197                     struct iscsi_cls_conn *cls_conn, int is_leading)
3198 {
3199         struct iscsi_session *session = cls_session->dd_data;
3200         struct iscsi_conn *conn = cls_conn->dd_data;
3201
3202         spin_lock_bh(&session->frwd_lock);
3203         if (is_leading)
3204                 session->leadconn = conn;
3205         spin_unlock_bh(&session->frwd_lock);
3206
3207         /*
3208          * Unblock xmitworker(), Login Phase will pass through.
3209          */
3210         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
3211         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
3212         return 0;
3213 }
3214 EXPORT_SYMBOL_GPL(iscsi_conn_bind);
3215
3216 int iscsi_switch_str_param(char **param, char *new_val_buf)
3217 {
3218         char *new_val;
3219
3220         if (*param) {
3221                 if (!strcmp(*param, new_val_buf))
3222                         return 0;
3223         }
3224
3225         new_val = kstrdup(new_val_buf, GFP_NOIO);
3226         if (!new_val)
3227                 return -ENOMEM;
3228
3229         kfree(*param);
3230         *param = new_val;
3231         return 0;
3232 }
3233 EXPORT_SYMBOL_GPL(iscsi_switch_str_param);
3234
3235 int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
3236                     enum iscsi_param param, char *buf, int buflen)
3237 {
3238         struct iscsi_conn *conn = cls_conn->dd_data;
3239         struct iscsi_session *session = conn->session;
3240         int val;
3241
3242         switch(param) {
3243         case ISCSI_PARAM_FAST_ABORT:
3244                 sscanf(buf, "%d", &session->fast_abort);
3245                 break;
3246         case ISCSI_PARAM_ABORT_TMO:
3247                 sscanf(buf, "%d", &session->abort_timeout);
3248                 break;
3249         case ISCSI_PARAM_LU_RESET_TMO:
3250                 sscanf(buf, "%d", &session->lu_reset_timeout);
3251                 break;
3252         case ISCSI_PARAM_TGT_RESET_TMO:
3253                 sscanf(buf, "%d", &session->tgt_reset_timeout);
3254                 break;
3255         case ISCSI_PARAM_PING_TMO:
3256                 sscanf(buf, "%d", &conn->ping_timeout);
3257                 break;
3258         case ISCSI_PARAM_RECV_TMO:
3259                 sscanf(buf, "%d", &conn->recv_timeout);
3260                 break;
3261         case ISCSI_PARAM_MAX_RECV_DLENGTH:
3262                 sscanf(buf, "%d", &conn->max_recv_dlength);
3263                 break;
3264         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3265                 sscanf(buf, "%d", &conn->max_xmit_dlength);
3266                 break;
3267         case ISCSI_PARAM_HDRDGST_EN:
3268                 sscanf(buf, "%d", &conn->hdrdgst_en);
3269                 break;
3270         case ISCSI_PARAM_DATADGST_EN:
3271                 sscanf(buf, "%d", &conn->datadgst_en);
3272                 break;
3273         case ISCSI_PARAM_INITIAL_R2T_EN:
3274                 sscanf(buf, "%d", &session->initial_r2t_en);
3275                 break;
3276         case ISCSI_PARAM_MAX_R2T:
3277                 sscanf(buf, "%hu", &session->max_r2t);
3278                 break;
3279         case ISCSI_PARAM_IMM_DATA_EN:
3280                 sscanf(buf, "%d", &session->imm_data_en);
3281                 break;
3282         case ISCSI_PARAM_FIRST_BURST:
3283                 sscanf(buf, "%d", &session->first_burst);
3284                 break;
3285         case ISCSI_PARAM_MAX_BURST:
3286                 sscanf(buf, "%d", &session->max_burst);
3287                 break;
3288         case ISCSI_PARAM_PDU_INORDER_EN:
3289                 sscanf(buf, "%d", &session->pdu_inorder_en);
3290                 break;
3291         case ISCSI_PARAM_DATASEQ_INORDER_EN:
3292                 sscanf(buf, "%d", &session->dataseq_inorder_en);
3293                 break;
3294         case ISCSI_PARAM_ERL:
3295                 sscanf(buf, "%d", &session->erl);
3296                 break;
3297         case ISCSI_PARAM_EXP_STATSN:
3298                 sscanf(buf, "%u", &conn->exp_statsn);
3299                 break;
3300         case ISCSI_PARAM_USERNAME:
3301                 return iscsi_switch_str_param(&session->username, buf);
3302         case ISCSI_PARAM_USERNAME_IN:
3303                 return iscsi_switch_str_param(&session->username_in, buf);
3304         case ISCSI_PARAM_PASSWORD:
3305                 return iscsi_switch_str_param(&session->password, buf);
3306         case ISCSI_PARAM_PASSWORD_IN:
3307                 return iscsi_switch_str_param(&session->password_in, buf);
3308         case ISCSI_PARAM_TARGET_NAME:
3309                 return iscsi_switch_str_param(&session->targetname, buf);
3310         case ISCSI_PARAM_TARGET_ALIAS:
3311                 return iscsi_switch_str_param(&session->targetalias, buf);
3312         case ISCSI_PARAM_TPGT:
3313                 sscanf(buf, "%d", &session->tpgt);
3314                 break;
3315         case ISCSI_PARAM_PERSISTENT_PORT:
3316                 sscanf(buf, "%d", &conn->persistent_port);
3317                 break;
3318         case ISCSI_PARAM_PERSISTENT_ADDRESS:
3319                 return iscsi_switch_str_param(&conn->persistent_address, buf);
3320         case ISCSI_PARAM_IFACE_NAME:
3321                 return iscsi_switch_str_param(&session->ifacename, buf);
3322         case ISCSI_PARAM_INITIATOR_NAME:
3323                 return iscsi_switch_str_param(&session->initiatorname, buf);
3324         case ISCSI_PARAM_BOOT_ROOT:
3325                 return iscsi_switch_str_param(&session->boot_root, buf);
3326         case ISCSI_PARAM_BOOT_NIC:
3327                 return iscsi_switch_str_param(&session->boot_nic, buf);
3328         case ISCSI_PARAM_BOOT_TARGET:
3329                 return iscsi_switch_str_param(&session->boot_target, buf);
3330         case ISCSI_PARAM_PORTAL_TYPE:
3331                 return iscsi_switch_str_param(&session->portal_type, buf);
3332         case ISCSI_PARAM_DISCOVERY_PARENT_TYPE:
3333                 return iscsi_switch_str_param(&session->discovery_parent_type,
3334                                               buf);
3335         case ISCSI_PARAM_DISCOVERY_SESS:
3336                 sscanf(buf, "%d", &val);
3337                 session->discovery_sess = !!val;
3338                 break;
3339         case ISCSI_PARAM_LOCAL_IPADDR:
3340                 return iscsi_switch_str_param(&conn->local_ipaddr, buf);
3341         default:
3342                 return -ENOSYS;
3343         }
3344
3345         return 0;
3346 }
3347 EXPORT_SYMBOL_GPL(iscsi_set_param);
3348
3349 int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
3350                             enum iscsi_param param, char *buf)
3351 {
3352         struct iscsi_session *session = cls_session->dd_data;
3353         int len;
3354
3355         switch(param) {
3356         case ISCSI_PARAM_FAST_ABORT:
3357                 len = sprintf(buf, "%d\n", session->fast_abort);
3358                 break;
3359         case ISCSI_PARAM_ABORT_TMO:
3360                 len = sprintf(buf, "%d\n", session->abort_timeout);
3361                 break;
3362         case ISCSI_PARAM_LU_RESET_TMO:
3363                 len = sprintf(buf, "%d\n", session->lu_reset_timeout);
3364                 break;
3365         case ISCSI_PARAM_TGT_RESET_TMO:
3366                 len = sprintf(buf, "%d\n", session->tgt_reset_timeout);
3367                 break;
3368         case ISCSI_PARAM_INITIAL_R2T_EN:
3369                 len = sprintf(buf, "%d\n", session->initial_r2t_en);
3370                 break;
3371         case ISCSI_PARAM_MAX_R2T:
3372                 len = sprintf(buf, "%hu\n", session->max_r2t);
3373                 break;
3374         case ISCSI_PARAM_IMM_DATA_EN:
3375                 len = sprintf(buf, "%d\n", session->imm_data_en);
3376                 break;
3377         case ISCSI_PARAM_FIRST_BURST:
3378                 len = sprintf(buf, "%u\n", session->first_burst);
3379                 break;
3380         case ISCSI_PARAM_MAX_BURST:
3381                 len = sprintf(buf, "%u\n", session->max_burst);
3382                 break;
3383         case ISCSI_PARAM_PDU_INORDER_EN:
3384                 len = sprintf(buf, "%d\n", session->pdu_inorder_en);
3385                 break;
3386         case ISCSI_PARAM_DATASEQ_INORDER_EN:
3387                 len = sprintf(buf, "%d\n", session->dataseq_inorder_en);
3388                 break;
3389         case ISCSI_PARAM_DEF_TASKMGMT_TMO:
3390                 len = sprintf(buf, "%d\n", session->def_taskmgmt_tmo);
3391                 break;
3392         case ISCSI_PARAM_ERL:
3393                 len = sprintf(buf, "%d\n", session->erl);
3394                 break;
3395         case ISCSI_PARAM_TARGET_NAME:
3396                 len = sprintf(buf, "%s\n", session->targetname);
3397                 break;
3398         case ISCSI_PARAM_TARGET_ALIAS:
3399                 len = sprintf(buf, "%s\n", session->targetalias);
3400                 break;
3401         case ISCSI_PARAM_TPGT:
3402                 len = sprintf(buf, "%d\n", session->tpgt);
3403                 break;
3404         case ISCSI_PARAM_USERNAME:
3405                 len = sprintf(buf, "%s\n", session->username);
3406                 break;
3407         case ISCSI_PARAM_USERNAME_IN:
3408                 len = sprintf(buf, "%s\n", session->username_in);
3409                 break;
3410         case ISCSI_PARAM_PASSWORD:
3411                 len = sprintf(buf, "%s\n", session->password);
3412                 break;
3413         case ISCSI_PARAM_PASSWORD_IN:
3414                 len = sprintf(buf, "%s\n", session->password_in);
3415                 break;
3416         case ISCSI_PARAM_IFACE_NAME:
3417                 len = sprintf(buf, "%s\n", session->ifacename);
3418                 break;
3419         case ISCSI_PARAM_INITIATOR_NAME:
3420                 len = sprintf(buf, "%s\n", session->initiatorname);
3421                 break;
3422         case ISCSI_PARAM_BOOT_ROOT:
3423                 len = sprintf(buf, "%s\n", session->boot_root);
3424                 break;
3425         case ISCSI_PARAM_BOOT_NIC:
3426                 len = sprintf(buf, "%s\n", session->boot_nic);
3427                 break;
3428         case ISCSI_PARAM_BOOT_TARGET:
3429                 len = sprintf(buf, "%s\n", session->boot_target);
3430                 break;
3431         case ISCSI_PARAM_AUTO_SND_TGT_DISABLE:
3432                 len = sprintf(buf, "%u\n", session->auto_snd_tgt_disable);
3433                 break;
3434         case ISCSI_PARAM_DISCOVERY_SESS:
3435                 len = sprintf(buf, "%u\n", session->discovery_sess);
3436                 break;
3437         case ISCSI_PARAM_PORTAL_TYPE:
3438                 len = sprintf(buf, "%s\n", session->portal_type);
3439                 break;
3440         case ISCSI_PARAM_CHAP_AUTH_EN:
3441                 len = sprintf(buf, "%u\n", session->chap_auth_en);
3442                 break;
3443         case ISCSI_PARAM_DISCOVERY_LOGOUT_EN:
3444                 len = sprintf(buf, "%u\n", session->discovery_logout_en);
3445                 break;
3446         case ISCSI_PARAM_BIDI_CHAP_EN:
3447                 len = sprintf(buf, "%u\n", session->bidi_chap_en);
3448                 break;
3449         case ISCSI_PARAM_DISCOVERY_AUTH_OPTIONAL:
3450                 len = sprintf(buf, "%u\n", session->discovery_auth_optional);
3451                 break;
3452         case ISCSI_PARAM_DEF_TIME2WAIT:
3453                 len = sprintf(buf, "%d\n", session->time2wait);
3454                 break;
3455         case ISCSI_PARAM_DEF_TIME2RETAIN:
3456                 len = sprintf(buf, "%d\n", session->time2retain);
3457                 break;
3458         case ISCSI_PARAM_TSID:
3459                 len = sprintf(buf, "%u\n", session->tsid);
3460                 break;
3461         case ISCSI_PARAM_ISID:
3462                 len = sprintf(buf, "%02x%02x%02x%02x%02x%02x\n",
3463                               session->isid[0], session->isid[1],
3464                               session->isid[2], session->isid[3],
3465                               session->isid[4], session->isid[5]);
3466                 break;
3467         case ISCSI_PARAM_DISCOVERY_PARENT_IDX:
3468                 len = sprintf(buf, "%u\n", session->discovery_parent_idx);
3469                 break;
3470         case ISCSI_PARAM_DISCOVERY_PARENT_TYPE:
3471                 if (session->discovery_parent_type)
3472                         len = sprintf(buf, "%s\n",
3473                                       session->discovery_parent_type);
3474                 else
3475                         len = sprintf(buf, "\n");
3476                 break;
3477         default:
3478                 return -ENOSYS;
3479         }
3480
3481         return len;
3482 }
3483 EXPORT_SYMBOL_GPL(iscsi_session_get_param);
3484
3485 int iscsi_conn_get_addr_param(struct sockaddr_storage *addr,
3486                               enum iscsi_param param, char *buf)
3487 {
3488         struct sockaddr_in6 *sin6 = NULL;
3489         struct sockaddr_in *sin = NULL;
3490         int len;
3491
3492         switch (addr->ss_family) {
3493         case AF_INET:
3494                 sin = (struct sockaddr_in *)addr;
3495                 break;
3496         case AF_INET6:
3497                 sin6 = (struct sockaddr_in6 *)addr;
3498                 break;
3499         default:
3500                 return -EINVAL;
3501         }
3502
3503         switch (param) {
3504         case ISCSI_PARAM_CONN_ADDRESS:
3505         case ISCSI_HOST_PARAM_IPADDRESS:
3506                 if (sin)
3507                         len = sprintf(buf, "%pI4\n", &sin->sin_addr.s_addr);
3508                 else
3509                         len = sprintf(buf, "%pI6\n", &sin6->sin6_addr);
3510                 break;
3511         case ISCSI_PARAM_CONN_PORT:
3512         case ISCSI_PARAM_LOCAL_PORT:
3513                 if (sin)
3514                         len = sprintf(buf, "%hu\n", be16_to_cpu(sin->sin_port));
3515                 else
3516                         len = sprintf(buf, "%hu\n",
3517                                       be16_to_cpu(sin6->sin6_port));
3518                 break;
3519         default:
3520                 return -EINVAL;
3521         }
3522
3523         return len;
3524 }
3525 EXPORT_SYMBOL_GPL(iscsi_conn_get_addr_param);
3526
3527 int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
3528                          enum iscsi_param param, char *buf)
3529 {
3530         struct iscsi_conn *conn = cls_conn->dd_data;
3531         int len;
3532
3533         switch(param) {
3534         case ISCSI_PARAM_PING_TMO:
3535                 len = sprintf(buf, "%u\n", conn->ping_timeout);
3536                 break;
3537         case ISCSI_PARAM_RECV_TMO:
3538                 len = sprintf(buf, "%u\n", conn->recv_timeout);
3539                 break;
3540         case ISCSI_PARAM_MAX_RECV_DLENGTH:
3541                 len = sprintf(buf, "%u\n", conn->max_recv_dlength);
3542                 break;
3543         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
3544                 len = sprintf(buf, "%u\n", conn->max_xmit_dlength);
3545                 break;
3546         case ISCSI_PARAM_HDRDGST_EN:
3547                 len = sprintf(buf, "%d\n", conn->hdrdgst_en);
3548                 break;
3549         case ISCSI_PARAM_DATADGST_EN:
3550                 len = sprintf(buf, "%d\n", conn->datadgst_en);
3551                 break;
3552         case ISCSI_PARAM_IFMARKER_EN:
3553                 len = sprintf(buf, "%d\n", conn->ifmarker_en);
3554                 break;
3555         case ISCSI_PARAM_OFMARKER_EN:
3556                 len = sprintf(buf, "%d\n", conn->ofmarker_en);
3557                 break;
3558         case ISCSI_PARAM_EXP_STATSN:
3559                 len = sprintf(buf, "%u\n", conn->exp_statsn);
3560                 break;
3561         case ISCSI_PARAM_PERSISTENT_PORT:
3562                 len = sprintf(buf, "%d\n", conn->persistent_port);
3563                 break;
3564         case ISCSI_PARAM_PERSISTENT_ADDRESS:
3565                 len = sprintf(buf, "%s\n", conn->persistent_address);
3566                 break;
3567         case ISCSI_PARAM_STATSN:
3568                 len = sprintf(buf, "%u\n", conn->statsn);
3569                 break;
3570         case ISCSI_PARAM_MAX_SEGMENT_SIZE:
3571                 len = sprintf(buf, "%u\n", conn->max_segment_size);
3572                 break;
3573         case ISCSI_PARAM_KEEPALIVE_TMO:
3574                 len = sprintf(buf, "%u\n", conn->keepalive_tmo);
3575                 break;
3576         case ISCSI_PARAM_LOCAL_PORT:
3577                 len = sprintf(buf, "%u\n", conn->local_port);
3578                 break;
3579         case ISCSI_PARAM_TCP_TIMESTAMP_STAT:
3580                 len = sprintf(buf, "%u\n", conn->tcp_timestamp_stat);
3581                 break;
3582         case ISCSI_PARAM_TCP_NAGLE_DISABLE:
3583                 len = sprintf(buf, "%u\n", conn->tcp_nagle_disable);
3584                 break;
3585         case ISCSI_PARAM_TCP_WSF_DISABLE:
3586                 len = sprintf(buf, "%u\n", conn->tcp_wsf_disable);
3587                 break;
3588         case ISCSI_PARAM_TCP_TIMER_SCALE:
3589                 len = sprintf(buf, "%u\n", conn->tcp_timer_scale);
3590                 break;
3591         case ISCSI_PARAM_TCP_TIMESTAMP_EN:
3592                 len = sprintf(buf, "%u\n", conn->tcp_timestamp_en);
3593                 break;
3594         case ISCSI_PARAM_IP_FRAGMENT_DISABLE:
3595                 len = sprintf(buf, "%u\n", conn->fragment_disable);
3596                 break;
3597         case ISCSI_PARAM_IPV4_TOS:
3598                 len = sprintf(buf, "%u\n", conn->ipv4_tos);
3599                 break;
3600         case ISCSI_PARAM_IPV6_TC:
3601                 len = sprintf(buf, "%u\n", conn->ipv6_traffic_class);
3602                 break;
3603         case ISCSI_PARAM_IPV6_FLOW_LABEL:
3604                 len = sprintf(buf, "%u\n", conn->ipv6_flow_label);
3605                 break;
3606         case ISCSI_PARAM_IS_FW_ASSIGNED_IPV6:
3607                 len = sprintf(buf, "%u\n", conn->is_fw_assigned_ipv6);
3608                 break;
3609         case ISCSI_PARAM_TCP_XMIT_WSF:
3610                 len = sprintf(buf, "%u\n", conn->tcp_xmit_wsf);
3611                 break;
3612         case ISCSI_PARAM_TCP_RECV_WSF:
3613                 len = sprintf(buf, "%u\n", conn->tcp_recv_wsf);
3614                 break;
3615         case ISCSI_PARAM_LOCAL_IPADDR:
3616                 len = sprintf(buf, "%s\n", conn->local_ipaddr);
3617                 break;
3618         default:
3619                 return -ENOSYS;
3620         }
3621
3622         return len;
3623 }
3624 EXPORT_SYMBOL_GPL(iscsi_conn_get_param);
3625
3626 int iscsi_host_get_param(struct Scsi_Host *shost, enum iscsi_host_param param,
3627                          char *buf)
3628 {
3629         struct iscsi_host *ihost = shost_priv(shost);
3630         int len;
3631
3632         switch (param) {
3633         case ISCSI_HOST_PARAM_NETDEV_NAME:
3634                 len = sprintf(buf, "%s\n", ihost->netdev);
3635                 break;
3636         case ISCSI_HOST_PARAM_HWADDRESS:
3637                 len = sprintf(buf, "%s\n", ihost->hwaddress);
3638                 break;
3639         case ISCSI_HOST_PARAM_INITIATOR_NAME:
3640                 len = sprintf(buf, "%s\n", ihost->initiatorname);
3641                 break;
3642         default:
3643                 return -ENOSYS;
3644         }
3645
3646         return len;
3647 }
3648 EXPORT_SYMBOL_GPL(iscsi_host_get_param);
3649
3650 int iscsi_host_set_param(struct Scsi_Host *shost, enum iscsi_host_param param,
3651                          char *buf, int buflen)
3652 {
3653         struct iscsi_host *ihost = shost_priv(shost);
3654
3655         switch (param) {
3656         case ISCSI_HOST_PARAM_NETDEV_NAME:
3657                 return iscsi_switch_str_param(&ihost->netdev, buf);
3658         case ISCSI_HOST_PARAM_HWADDRESS:
3659                 return iscsi_switch_str_param(&ihost->hwaddress, buf);
3660         case ISCSI_HOST_PARAM_INITIATOR_NAME:
3661                 return iscsi_switch_str_param(&ihost->initiatorname, buf);
3662         default:
3663                 return -ENOSYS;
3664         }
3665
3666         return 0;
3667 }
3668 EXPORT_SYMBOL_GPL(iscsi_host_set_param);
3669
3670 MODULE_AUTHOR("Mike Christie");
3671 MODULE_DESCRIPTION("iSCSI library functions");
3672 MODULE_LICENSE("GPL");