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