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