drivers/scsi/libiscsi.c

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