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 <asm/unaligned.h>
  29 #include <net/tcp.h>
  30 #include <scsi/scsi_cmnd.h>
  31 #include <scsi/scsi_device.h>
  32 #include <scsi/scsi_eh.h>
  33 #include <scsi/scsi_tcq.h>
  34 #include <scsi/scsi_host.h>
  35 #include <scsi/scsi.h>
  36 #include <scsi/iscsi_proto.h>
  37 #include <scsi/scsi_transport.h>
  38 #include <scsi/scsi_transport_iscsi.h>
  39 #include <scsi/libiscsi.h>
  40
  41 /* Serial Number Arithmetic, 32 bits, less than, RFC1982 */
  42 #define SNA32_CHECK 2147483648UL
  43
  44 static int iscsi_sna_lt(u32 n1, u32 n2)
  45 {
  46         return n1 != n2 && ((n1 < n2 && (n2 - n1 < SNA32_CHECK)) ||
  47                             (n1 > n2 && (n2 - n1 < SNA32_CHECK)));
  48 }
  49
  50 /* Serial Number Arithmetic, 32 bits, less than, RFC1982 */
  51 static int iscsi_sna_lte(u32 n1, u32 n2)
  52 {
  53         return n1 == n2 || ((n1 < n2 && (n2 - n1 < SNA32_CHECK)) ||
  54                             (n1 > n2 && (n2 - n1 < SNA32_CHECK)));
  55 }
  56
  57 void
  58 iscsi_update_cmdsn(struct iscsi_session *session, struct iscsi_nopin *hdr)
  59 {
  60         uint32_t max_cmdsn = be32_to_cpu(hdr->max_cmdsn);
  61         uint32_t exp_cmdsn = be32_to_cpu(hdr->exp_cmdsn);
  62
  63         /*
  64          * standard specifies this check for when to update expected and
  65          * max sequence numbers
  66          */
  67         if (iscsi_sna_lt(max_cmdsn, exp_cmdsn - 1))
  68                 return;
  69
  70         if (exp_cmdsn != session->exp_cmdsn &&
  71             !iscsi_sna_lt(exp_cmdsn, session->exp_cmdsn))
  72                 session->exp_cmdsn = exp_cmdsn;
  73
  74         if (max_cmdsn != session->max_cmdsn &&
  75             !iscsi_sna_lt(max_cmdsn, session->max_cmdsn)) {
  76                 session->max_cmdsn = max_cmdsn;
  77                 /*
  78                  * if the window closed with IO queued, then kick the
  79                  * xmit thread
  80                  */
  81                 if (!list_empty(&session->leadconn->xmitqueue) ||
  82                     !list_empty(&session->leadconn->mgmtqueue)) {
  83                         if (!(session->tt->caps & CAP_DATA_PATH_OFFLOAD))
  84                                 scsi_queue_work(session->host,
  85                                                 &session->leadconn->xmitwork);
  86                 }
  87         }
  88 }
  89 EXPORT_SYMBOL_GPL(iscsi_update_cmdsn);
  90
  91 void iscsi_prep_unsolicit_data_pdu(struct iscsi_task *task,
  92                                    struct iscsi_data *hdr)
  93 {
  94         struct iscsi_conn *conn = task->conn;
  95
  96         memset(hdr, 0, sizeof(struct iscsi_data));
  97         hdr->ttt = cpu_to_be32(ISCSI_RESERVED_TAG);
  98         hdr->datasn = cpu_to_be32(task->unsol_datasn);
  99         task->unsol_datasn++;
 100         hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
 101         memcpy(hdr->lun, task->hdr->lun, sizeof(hdr->lun));
 102
 103         hdr->itt = task->hdr->itt;
 104         hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
 105         hdr->offset = cpu_to_be32(task->unsol_offset);
 106
 107         if (task->unsol_count > conn->max_xmit_dlength) {
 108                 hton24(hdr->dlength, conn->max_xmit_dlength);
 109                 task->data_count = conn->max_xmit_dlength;
 110                 task->unsol_offset += task->data_count;
 111                 hdr->flags = 0;
 112         } else {
 113                 hton24(hdr->dlength, task->unsol_count);
 114                 task->data_count = task->unsol_count;
 115                 hdr->flags = ISCSI_FLAG_CMD_FINAL;
 116         }
 117 }
 118 EXPORT_SYMBOL_GPL(iscsi_prep_unsolicit_data_pdu);
 119
 120 static int iscsi_add_hdr(struct iscsi_task *task, unsigned len)
 121 {
 122         unsigned exp_len = task->hdr_len + len;
 123
 124         if (exp_len > task->hdr_max) {
 125                 WARN_ON(1);
 126                 return -EINVAL;
 127         }
 128
 129         WARN_ON(len & (ISCSI_PAD_LEN - 1)); /* caller must pad the AHS */
 130         task->hdr_len = exp_len;
 131         return 0;
 132 }
 133
 134 /*
 135  * make an extended cdb AHS
 136  */
 137 static int iscsi_prep_ecdb_ahs(struct iscsi_task *task)
 138 {
 139         struct scsi_cmnd *cmd = task->sc;
 140         unsigned rlen, pad_len;
 141         unsigned short ahslength;
 142         struct iscsi_ecdb_ahdr *ecdb_ahdr;
 143         int rc;
 144
 145         ecdb_ahdr = iscsi_next_hdr(task);
 146         rlen = cmd->cmd_len - ISCSI_CDB_SIZE;
 147
 148         BUG_ON(rlen > sizeof(ecdb_ahdr->ecdb));
 149         ahslength = rlen + sizeof(ecdb_ahdr->reserved);
 150
 151         pad_len = iscsi_padding(rlen);
 152
 153         rc = iscsi_add_hdr(task, sizeof(ecdb_ahdr->ahslength) +
 154                            sizeof(ecdb_ahdr->ahstype) + ahslength + pad_len);
 155         if (rc)
 156                 return rc;
 157
 158         if (pad_len)
 159                 memset(&ecdb_ahdr->ecdb[rlen], 0, pad_len);
 160
 161         ecdb_ahdr->ahslength = cpu_to_be16(ahslength);
 162         ecdb_ahdr->ahstype = ISCSI_AHSTYPE_CDB;
 163         ecdb_ahdr->reserved = 0;
 164         memcpy(ecdb_ahdr->ecdb, cmd->cmnd + ISCSI_CDB_SIZE, rlen);
 165
 166         debug_scsi("iscsi_prep_ecdb_ahs: varlen_cdb_len %d "
 167                    "rlen %d pad_len %d ahs_length %d iscsi_headers_size %u\n",
 168                    cmd->cmd_len, rlen, pad_len, ahslength, task->hdr_len);
 169
 170         return 0;
 171 }
 172
 173 static int iscsi_prep_bidi_ahs(struct iscsi_task *task)
 174 {
 175         struct scsi_cmnd *sc = task->sc;
 176         struct iscsi_rlength_ahdr *rlen_ahdr;
 177         int rc;
 178
 179         rlen_ahdr = iscsi_next_hdr(task);
 180         rc = iscsi_add_hdr(task, sizeof(*rlen_ahdr));
 181         if (rc)
 182                 return rc;
 183
 184         rlen_ahdr->ahslength =
 185                 cpu_to_be16(sizeof(rlen_ahdr->read_length) +
 186                                                   sizeof(rlen_ahdr->reserved));
 187         rlen_ahdr->ahstype = ISCSI_AHSTYPE_RLENGTH;
 188         rlen_ahdr->reserved = 0;
 189         rlen_ahdr->read_length = cpu_to_be32(scsi_in(sc)->length);
 190
 191         debug_scsi("bidi-in rlen_ahdr->read_length(%d) "
 192                    "rlen_ahdr->ahslength(%d)\n",
 193                    be32_to_cpu(rlen_ahdr->read_length),
 194                    be16_to_cpu(rlen_ahdr->ahslength));
 195         return 0;
 196 }
 197
 198 /**
 199  * iscsi_prep_scsi_cmd_pdu - prep iscsi scsi cmd pdu
 200  * @task: iscsi task
 201  *
 202  * Prep basic iSCSI PDU fields for a scsi cmd pdu. The LLD should set
 203  * fields like dlength or final based on how much data it sends
 204  */
 205 static int iscsi_prep_scsi_cmd_pdu(struct iscsi_task *task)
 206 {
 207         struct iscsi_conn *conn = task->conn;
 208         struct iscsi_session *session = conn->session;
 209         struct iscsi_cmd *hdr = task->hdr;
 210         struct scsi_cmnd *sc = task->sc;
 211         unsigned hdrlength, cmd_len;
 212         int rc;
 213
 214         task->hdr_len = 0;
 215         rc = iscsi_add_hdr(task, sizeof(*hdr));
 216         if (rc)
 217                 return rc;
 218         hdr->opcode = ISCSI_OP_SCSI_CMD;
 219         hdr->flags = ISCSI_ATTR_SIMPLE;
 220         int_to_scsilun(sc->device->lun, (struct scsi_lun *)hdr->lun);
 221         hdr->itt = build_itt(task->itt, session->age);
 222         hdr->cmdsn = cpu_to_be32(session->cmdsn);
 223         session->cmdsn++;
 224         hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
 225         cmd_len = sc->cmd_len;
 226         if (cmd_len < ISCSI_CDB_SIZE)
 227                 memset(&hdr->cdb[cmd_len], 0, ISCSI_CDB_SIZE - cmd_len);
 228         else if (cmd_len > ISCSI_CDB_SIZE) {
 229                 rc = iscsi_prep_ecdb_ahs(task);
 230                 if (rc)
 231                         return rc;
 232                 cmd_len = ISCSI_CDB_SIZE;
 233         }
 234         memcpy(hdr->cdb, sc->cmnd, cmd_len);
 235
 236         task->imm_count = 0;
 237         if (scsi_bidi_cmnd(sc)) {
 238                 hdr->flags |= ISCSI_FLAG_CMD_READ;
 239                 rc = iscsi_prep_bidi_ahs(task);
 240                 if (rc)
 241                         return rc;
 242         }
 243         if (sc->sc_data_direction == DMA_TO_DEVICE) {
 244                 unsigned out_len = scsi_out(sc)->length;
 245                 hdr->data_length = cpu_to_be32(out_len);
 246                 hdr->flags |= ISCSI_FLAG_CMD_WRITE;
 247                 /*
 248                  * Write counters:
 249                  *
 250                  *      imm_count       bytes to be sent right after
 251                  *                      SCSI PDU Header
 252                  *
 253                  *      unsol_count     bytes(as Data-Out) to be sent
 254                  *                      without R2T ack right after
 255                  *                      immediate data
 256                  *
 257                  *      r2t_data_count  bytes to be sent via R2T ack's
 258                  *
 259                  *      pad_count       bytes to be sent as zero-padding
 260                  */
 261                 task->unsol_count = 0;
 262                 task->unsol_offset = 0;
 263                 task->unsol_datasn = 0;
 264
 265                 if (session->imm_data_en) {
 266                         if (out_len >= session->first_burst)
 267                                 task->imm_count = min(session->first_burst,
 268                                                         conn->max_xmit_dlength);
 269                         else
 270                                 task->imm_count = min(out_len,
 271                                                         conn->max_xmit_dlength);
 272                         hton24(hdr->dlength, task->imm_count);
 273                 } else
 274                         zero_data(hdr->dlength);
 275
 276                 if (!session->initial_r2t_en) {
 277                         task->unsol_count = min(session->first_burst, out_len)
 278                                                              - task->imm_count;
 279                         task->unsol_offset = task->imm_count;
 280                 }
 281
 282                 if (!task->unsol_count)
 283                         /* No unsolicit Data-Out's */
 284                         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
 285         } else {
 286                 hdr->flags |= ISCSI_FLAG_CMD_FINAL;
 287                 zero_data(hdr->dlength);
 288                 hdr->data_length = cpu_to_be32(scsi_in(sc)->length);
 289
 290                 if (sc->sc_data_direction == DMA_FROM_DEVICE)
 291                         hdr->flags |= ISCSI_FLAG_CMD_READ;
 292         }
 293
 294         /* calculate size of additional header segments (AHSs) */
 295         hdrlength = task->hdr_len - sizeof(*hdr);
 296
 297         WARN_ON(hdrlength & (ISCSI_PAD_LEN-1));
 298         hdrlength /= ISCSI_PAD_LEN;
 299
 300         WARN_ON(hdrlength >= 256);
 301         hdr->hlength = hdrlength & 0xFF;
 302
 303         if (conn->session->tt->init_task &&
 304             conn->session->tt->init_task(task))
 305                 return -EIO;
 306
 307         task->state = ISCSI_TASK_RUNNING;
 308         list_move_tail(&task->running, &conn->run_list);
 309
 310         conn->scsicmd_pdus_cnt++;
 311         debug_scsi("iscsi prep [%s cid %d sc %p cdb 0x%x itt 0x%x len %d "
 312                    "bidi_len %d cmdsn %d win %d]\n", scsi_bidi_cmnd(sc) ?
 313                    "bidirectional" : sc->sc_data_direction == DMA_TO_DEVICE ?
 314                    "write" : "read", conn->id, sc, sc->cmnd[0], task->itt,
 315                    scsi_bufflen(sc),
 316                    scsi_bidi_cmnd(sc) ? scsi_in(sc)->length : 0,
 317                    session->cmdsn, session->max_cmdsn - session->exp_cmdsn + 1);
 318         return 0;
 319 }
 320
 321 /**
 322  * iscsi_complete_command - finish a task
 323  * @task: iscsi cmd task
 324  *
 325  * Must be called with session lock.
 326  * This function returns the scsi command to scsi-ml or cleans
 327  * up mgmt tasks then returns the task to the pool.
 328  */
 329 static void iscsi_complete_command(struct iscsi_task *task)
 330 {
 331         struct iscsi_conn *conn = task->conn;
 332         struct iscsi_session *session = conn->session;
 333         struct scsi_cmnd *sc = task->sc;
 334
 335         list_del_init(&task->running);
 336         task->state = ISCSI_TASK_COMPLETED;
 337         task->sc = NULL;
 338
 339         if (conn->task == task)
 340                 conn->task = NULL;
 341         /*
 342          * login task is preallocated so do not free
 343          */
 344         if (conn->login_task == task)
 345                 return;
 346
 347         __kfifo_put(session->cmdpool.queue, (void*)&task, sizeof(void*));
 348
 349         if (conn->ping_task == task)
 350                 conn->ping_task = NULL;
 351
 352         if (sc) {
 353                 task->sc = NULL;
 354                 /* SCSI eh reuses commands to verify us */
 355                 sc->SCp.ptr = NULL;
 356                 /*
 357                  * queue command may call this to free the task, but
 358                  * not have setup the sc callback
 359                  */
 360                 if (sc->scsi_done)
 361                         sc->scsi_done(sc);
 362         }
 363 }
 364
 365 void __iscsi_get_task(struct iscsi_task *task)
 366 {
 367         atomic_inc(&task->refcount);
 368 }
 369 EXPORT_SYMBOL_GPL(__iscsi_get_task);
 370
 371 static void __iscsi_put_task(struct iscsi_task *task)
 372 {
 373         if (atomic_dec_and_test(&task->refcount))
 374                 iscsi_complete_command(task);
 375 }
 376
 377 void iscsi_put_task(struct iscsi_task *task)
 378 {
 379         struct iscsi_session *session = task->conn->session;
 380
 381         spin_lock_bh(&session->lock);
 382         __iscsi_put_task(task);
 383         spin_unlock_bh(&session->lock);
 384 }
 385 EXPORT_SYMBOL_GPL(iscsi_put_task);
 386
 387 /*
 388  * session lock must be held
 389  */
 390 static void fail_command(struct iscsi_conn *conn, struct iscsi_task *task,
 391                          int err)
 392 {
 393         struct scsi_cmnd *sc;
 394
 395         sc = task->sc;
 396         if (!sc)
 397                 return;
 398
 399         if (task->state == ISCSI_TASK_PENDING)
 400                 /*
 401                  * cmd never made it to the xmit thread, so we should not count
 402                  * the cmd in the sequencing
 403                  */
 404                 conn->session->queued_cmdsn--;
 405         else
 406                 conn->session->tt->cleanup_task(conn, task);
 407
 408         sc->result = err;
 409         if (!scsi_bidi_cmnd(sc))
 410                 scsi_set_resid(sc, scsi_bufflen(sc));
 411         else {
 412                 scsi_out(sc)->resid = scsi_out(sc)->length;
 413                 scsi_in(sc)->resid = scsi_in(sc)->length;
 414         }
 415
 416         if (conn->task == task)
 417                 conn->task = NULL;
 418         /* release ref from queuecommand */
 419         __iscsi_put_task(task);
 420 }
 421
 422 static int iscsi_prep_mgmt_task(struct iscsi_conn *conn,
 423                                 struct iscsi_task *task)
 424 {
 425         struct iscsi_session *session = conn->session;
 426         struct iscsi_hdr *hdr = (struct iscsi_hdr *)task->hdr;
 427         struct iscsi_nopout *nop = (struct iscsi_nopout *)hdr;
 428
 429         if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
 430                 return -ENOTCONN;
 431
 432         if (hdr->opcode != (ISCSI_OP_LOGIN | ISCSI_OP_IMMEDIATE) &&
 433             hdr->opcode != (ISCSI_OP_TEXT | ISCSI_OP_IMMEDIATE))
 434                 nop->exp_statsn = cpu_to_be32(conn->exp_statsn);
 435         /*
 436          * pre-format CmdSN for outgoing PDU.
 437          */
 438         nop->cmdsn = cpu_to_be32(session->cmdsn);
 439         if (hdr->itt != RESERVED_ITT) {
 440                 hdr->itt = build_itt(task->itt, session->age);
 441                 /*
 442                  * TODO: We always use immediate, so we never hit this.
 443                  * If we start to send tmfs or nops as non-immediate then
 444                  * we should start checking the cmdsn numbers for mgmt tasks.
 445                  */
 446                 if (conn->c_stage == ISCSI_CONN_STARTED &&
 447                     !(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
 448                         session->queued_cmdsn++;
 449                         session->cmdsn++;
 450                 }
 451         }
 452
 453         if (session->tt->init_task)
 454                 session->tt->init_task(task);
 455
 456         if ((hdr->opcode & ISCSI_OPCODE_MASK) == ISCSI_OP_LOGOUT)
 457                 session->state = ISCSI_STATE_LOGGING_OUT;
 458
 459         list_move_tail(&task->running, &conn->mgmt_run_list);
 460         debug_scsi("mgmtpdu [op 0x%x hdr->itt 0x%x datalen %d]\n",
 461                    hdr->opcode & ISCSI_OPCODE_MASK, hdr->itt,
 462                    task->data_count);
 463         return 0;
 464 }
 465
 466 static struct iscsi_task *
 467 __iscsi_conn_send_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 468                       char *data, uint32_t data_size)
 469 {
 470         struct iscsi_session *session = conn->session;
 471         struct iscsi_task *task;
 472
 473         if (session->state == ISCSI_STATE_TERMINATE)
 474                 return NULL;
 475
 476         if (hdr->opcode == (ISCSI_OP_LOGIN | ISCSI_OP_IMMEDIATE) ||
 477             hdr->opcode == (ISCSI_OP_TEXT | ISCSI_OP_IMMEDIATE))
 478                 /*
 479                  * Login and Text are sent serially, in
 480                  * request-followed-by-response sequence.
 481                  * Same task can be used. Same ITT must be used.
 482                  * Note that login_task is preallocated at conn_create().
 483                  */
 484                 task = conn->login_task;
 485         else {
 486                 BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
 487                 BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);
 488
 489                 if (!__kfifo_get(session->cmdpool.queue,
 490                                  (void*)&task, sizeof(void*)))
 491                         return NULL;
 492
 493                 if ((hdr->opcode == (ISCSI_OP_NOOP_OUT | ISCSI_OP_IMMEDIATE)) &&
 494                      hdr->ttt == RESERVED_ITT) {
 495                         conn->ping_task = task;
 496                         conn->last_ping = jiffies;
 497                 }
 498         }
 499         /*
 500          * released in complete pdu for task we expect a response for, and
 501          * released by the lld when it has transmitted the task for
 502          * pdus we do not expect a response for.
 503          */
 504         atomic_set(&task->refcount, 1);
 505         task->conn = conn;
 506         task->sc = NULL;
 507
 508         if (data_size) {
 509                 memcpy(task->data, data, data_size);
 510                 task->data_count = data_size;
 511         } else
 512                 task->data_count = 0;
 513
 514         memcpy(task->hdr, hdr, sizeof(struct iscsi_hdr));
 515         INIT_LIST_HEAD(&task->running);
 516         list_add_tail(&task->running, &conn->mgmtqueue);
 517
 518         if (session->tt->caps & CAP_DATA_PATH_OFFLOAD) {
 519                 if (iscsi_prep_mgmt_task(conn, task)) {
 520                         __iscsi_put_task(task);
 521                         return NULL;
 522                 }
 523
 524                 if (session->tt->xmit_task(task))
 525                         task = NULL;
 526
 527         } else
 528                 scsi_queue_work(conn->session->host, &conn->xmitwork);
 529
 530         return task;
 531 }
 532
 533 int iscsi_conn_send_pdu(struct iscsi_cls_conn *cls_conn, struct iscsi_hdr *hdr,
 534                         char *data, uint32_t data_size)
 535 {
 536         struct iscsi_conn *conn = cls_conn->dd_data;
 537         struct iscsi_session *session = conn->session;
 538         int err = 0;
 539
 540         spin_lock_bh(&session->lock);
 541         if (!__iscsi_conn_send_pdu(conn, hdr, data, data_size))
 542                 err = -EPERM;
 543         spin_unlock_bh(&session->lock);
 544         return err;
 545 }
 546 EXPORT_SYMBOL_GPL(iscsi_conn_send_pdu);
 547
 548 /**
 549  * iscsi_cmd_rsp - SCSI Command Response processing
 550  * @conn: iscsi connection
 551  * @hdr: iscsi header
 552  * @task: scsi command task
 553  * @data: cmd data buffer
 554  * @datalen: len of buffer
 555  *
 556  * iscsi_cmd_rsp sets up the scsi_cmnd fields based on the PDU and
 557  * then completes the command and task.
 558  **/
 559 static void iscsi_scsi_cmd_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 560                                struct iscsi_task *task, char *data,
 561                                int datalen)
 562 {
 563         struct iscsi_cmd_rsp *rhdr = (struct iscsi_cmd_rsp *)hdr;
 564         struct iscsi_session *session = conn->session;
 565         struct scsi_cmnd *sc = task->sc;
 566
 567         iscsi_update_cmdsn(session, (struct iscsi_nopin*)rhdr);
 568         conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 569
 570         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 571
 572         if (rhdr->response != ISCSI_STATUS_CMD_COMPLETED) {
 573                 sc->result = DID_ERROR << 16;
 574                 goto out;
 575         }
 576
 577         if (rhdr->cmd_status == SAM_STAT_CHECK_CONDITION) {
 578                 uint16_t senselen;
 579
 580                 if (datalen < 2) {
 581 invalid_datalen:
 582                         iscsi_conn_printk(KERN_ERR,  conn,
 583                                          "Got CHECK_CONDITION but invalid data "
 584                                          "buffer size of %d\n", datalen);
 585                         sc->result = DID_BAD_TARGET << 16;
 586                         goto out;
 587                 }
 588
 589                 senselen = get_unaligned_be16(data);
 590                 if (datalen < senselen)
 591                         goto invalid_datalen;
 592
 593                 memcpy(sc->sense_buffer, data + 2,
 594                        min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
 595                 debug_scsi("copied %d bytes of sense\n",
 596                            min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
 597         }
 598
 599         if (rhdr->flags & (ISCSI_FLAG_CMD_BIDI_UNDERFLOW |
 600                            ISCSI_FLAG_CMD_BIDI_OVERFLOW)) {
 601                 int res_count = be32_to_cpu(rhdr->bi_residual_count);
 602
 603                 if (scsi_bidi_cmnd(sc) && res_count > 0 &&
 604                                 (rhdr->flags & ISCSI_FLAG_CMD_BIDI_OVERFLOW ||
 605                                  res_count <= scsi_in(sc)->length))
 606                         scsi_in(sc)->resid = res_count;
 607                 else
 608                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 609         }
 610
 611         if (rhdr->flags & (ISCSI_FLAG_CMD_UNDERFLOW |
 612                            ISCSI_FLAG_CMD_OVERFLOW)) {
 613                 int res_count = be32_to_cpu(rhdr->residual_count);
 614
 615                 if (res_count > 0 &&
 616                     (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
 617                      res_count <= scsi_bufflen(sc)))
 618                         /* write side for bidi or uni-io set_resid */
 619                         scsi_set_resid(sc, res_count);
 620                 else
 621                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 622         }
 623 out:
 624         debug_scsi("done [sc %lx res %d itt 0x%x]\n",
 625                    (long)sc, sc->result, task->itt);
 626         conn->scsirsp_pdus_cnt++;
 627
 628         __iscsi_put_task(task);
 629 }
 630
 631 /**
 632  * iscsi_data_in_rsp - SCSI Data-In Response processing
 633  * @conn: iscsi connection
 634  * @hdr:  iscsi pdu
 635  * @task: scsi command task
 636  **/
 637 static void
 638 iscsi_data_in_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 639                   struct iscsi_task *task)
 640 {
 641         struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)hdr;
 642         struct scsi_cmnd *sc = task->sc;
 643
 644         if (!(rhdr->flags & ISCSI_FLAG_DATA_STATUS))
 645                 return;
 646
 647         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 648         conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 649         if (rhdr->flags & (ISCSI_FLAG_DATA_UNDERFLOW |
 650                            ISCSI_FLAG_DATA_OVERFLOW)) {
 651                 int res_count = be32_to_cpu(rhdr->residual_count);
 652
 653                 if (res_count > 0 &&
 654                     (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
 655                      res_count <= scsi_in(sc)->length))
 656                         scsi_in(sc)->resid = res_count;
 657                 else
 658                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 659         }
 660
 661         conn->scsirsp_pdus_cnt++;
 662         __iscsi_put_task(task);
 663 }
 664
 665 static void iscsi_tmf_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
 666 {
 667         struct iscsi_tm_rsp *tmf = (struct iscsi_tm_rsp *)hdr;
 668
 669         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 670         conn->tmfrsp_pdus_cnt++;
 671
 672         if (conn->tmf_state != TMF_QUEUED)
 673                 return;
 674
 675         if (tmf->response == ISCSI_TMF_RSP_COMPLETE)
 676                 conn->tmf_state = TMF_SUCCESS;
 677         else if (tmf->response == ISCSI_TMF_RSP_NO_TASK)
 678                 conn->tmf_state = TMF_NOT_FOUND;
 679         else
 680                 conn->tmf_state = TMF_FAILED;
 681         wake_up(&conn->ehwait);
 682 }
 683
 684 static void iscsi_send_nopout(struct iscsi_conn *conn, struct iscsi_nopin *rhdr)
 685 {
 686         struct iscsi_nopout hdr;
 687         struct iscsi_task *task;
 688
 689         if (!rhdr && conn->ping_task)
 690                 return;
 691
 692         memset(&hdr, 0, sizeof(struct iscsi_nopout));
 693         hdr.opcode = ISCSI_OP_NOOP_OUT | ISCSI_OP_IMMEDIATE;
 694         hdr.flags = ISCSI_FLAG_CMD_FINAL;
 695
 696         if (rhdr) {
 697                 memcpy(hdr.lun, rhdr->lun, 8);
 698                 hdr.ttt = rhdr->ttt;
 699                 hdr.itt = RESERVED_ITT;
 700         } else
 701                 hdr.ttt = RESERVED_ITT;
 702
 703         task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)&hdr, NULL, 0);
 704         if (!task)
 705                 iscsi_conn_printk(KERN_ERR, conn, "Could not send nopout\n");
 706 }
 707
 708 static int iscsi_handle_reject(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 709                                char *data, int datalen)
 710 {
 711         struct iscsi_reject *reject = (struct iscsi_reject *)hdr;
 712         struct iscsi_hdr rejected_pdu;
 713         uint32_t itt;
 714
 715         conn->exp_statsn = be32_to_cpu(reject->statsn) + 1;
 716
 717         if (reject->reason == ISCSI_REASON_DATA_DIGEST_ERROR) {
 718                 if (ntoh24(reject->dlength) > datalen)
 719                         return ISCSI_ERR_PROTO;
 720
 721                 if (ntoh24(reject->dlength) >= sizeof(struct iscsi_hdr)) {
 722                         memcpy(&rejected_pdu, data, sizeof(struct iscsi_hdr));
 723                         itt = get_itt(rejected_pdu.itt);
 724                         iscsi_conn_printk(KERN_ERR, conn,
 725                                           "itt 0x%x had pdu (op 0x%x) rejected "
 726                                           "due to DataDigest error.\n", itt,
 727                                           rejected_pdu.opcode);
 728                 }
 729         }
 730         return 0;
 731 }
 732
 733 /**
 734  * iscsi_itt_to_task - look up task by itt
 735  * @conn: iscsi connection
 736  * @itt: itt
 737  *
 738  * This should be used for mgmt tasks like login and nops, or if
 739  * the LDD's itt space does not include the session age.
 740  *
 741  * The session lock must be held.
 742  */
 743 static struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *conn, itt_t itt)
 744 {
 745         struct iscsi_session *session = conn->session;
 746         uint32_t i;
 747
 748         if (itt == RESERVED_ITT)
 749                 return NULL;
 750
 751         i = get_itt(itt);
 752         if (i >= session->cmds_max)
 753                 return NULL;
 754
 755         return session->cmds[i];
 756 }
 757
 758 /**
 759  * __iscsi_complete_pdu - complete pdu
 760  * @conn: iscsi conn
 761  * @hdr: iscsi header
 762  * @data: data buffer
 763  * @datalen: len of data buffer
 764  *
 765  * Completes pdu processing by freeing any resources allocated at
 766  * queuecommand or send generic. session lock must be held and verify
 767  * itt must have been called.
 768  */
 769 int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 770                          char *data, int datalen)
 771 {
 772         struct iscsi_session *session = conn->session;
 773         int opcode = hdr->opcode & ISCSI_OPCODE_MASK, rc = 0;
 774         struct iscsi_task *task;
 775         uint32_t itt;
 776
 777         conn->last_recv = jiffies;
 778         rc = iscsi_verify_itt(conn, hdr->itt);
 779         if (rc)
 780                 return rc;
 781
 782         if (hdr->itt != RESERVED_ITT)
 783                 itt = get_itt(hdr->itt);
 784         else
 785                 itt = ~0U;
 786
 787         debug_scsi("[op 0x%x cid %d itt 0x%x len %d]\n",
 788                    opcode, conn->id, itt, datalen);
 789
 790         if (itt == ~0U) {
 791                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
 792
 793                 switch(opcode) {
 794                 case ISCSI_OP_NOOP_IN:
 795                         if (datalen) {
 796                                 rc = ISCSI_ERR_PROTO;
 797                                 break;
 798                         }
 799
 800                         if (hdr->ttt == cpu_to_be32(ISCSI_RESERVED_TAG))
 801                                 break;
 802
 803                         iscsi_send_nopout(conn, (struct iscsi_nopin*)hdr);
 804                         break;
 805                 case ISCSI_OP_REJECT:
 806                         rc = iscsi_handle_reject(conn, hdr, data, datalen);
 807                         break;
 808                 case ISCSI_OP_ASYNC_EVENT:
 809                         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 810                         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
 811                                 rc = ISCSI_ERR_CONN_FAILED;
 812                         break;
 813                 default:
 814                         rc = ISCSI_ERR_BAD_OPCODE;
 815                         break;
 816                 }
 817                 goto out;
 818         }
 819
 820         switch(opcode) {
 821         case ISCSI_OP_SCSI_CMD_RSP:
 822         case ISCSI_OP_SCSI_DATA_IN:
 823                 task = iscsi_itt_to_ctask(conn, hdr->itt);
 824                 if (!task)
 825                         return ISCSI_ERR_BAD_ITT;
 826                 break;
 827         case ISCSI_OP_R2T:
 828                 /*
 829                  * LLD handles R2Ts if they need to.
 830                  */
 831                 return 0;
 832         case ISCSI_OP_LOGOUT_RSP:
 833         case ISCSI_OP_LOGIN_RSP:
 834         case ISCSI_OP_TEXT_RSP:
 835         case ISCSI_OP_SCSI_TMFUNC_RSP:
 836         case ISCSI_OP_NOOP_IN:
 837                 task = iscsi_itt_to_task(conn, hdr->itt);
 838                 if (!task)
 839                         return ISCSI_ERR_BAD_ITT;
 840                 break;
 841         default:
 842                 return ISCSI_ERR_BAD_OPCODE;
 843         }
 844
 845         switch(opcode) {
 846         case ISCSI_OP_SCSI_CMD_RSP:
 847                 iscsi_scsi_cmd_rsp(conn, hdr, task, data, datalen);
 848                 break;
 849         case ISCSI_OP_SCSI_DATA_IN:
 850                 iscsi_data_in_rsp(conn, hdr, task);
 851                 break;
 852         case ISCSI_OP_LOGOUT_RSP:
 853                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
 854                 if (datalen) {
 855                         rc = ISCSI_ERR_PROTO;
 856                         break;
 857                 }
 858                 conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 859                 goto recv_pdu;
 860         case ISCSI_OP_LOGIN_RSP:
 861         case ISCSI_OP_TEXT_RSP:
 862                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
 863                 /*
 864                  * login related PDU's exp_statsn is handled in
 865                  * userspace
 866                  */
 867                 goto recv_pdu;
 868         case ISCSI_OP_SCSI_TMFUNC_RSP:
 869                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
 870                 if (datalen) {
 871                         rc = ISCSI_ERR_PROTO;
 872                         break;
 873                 }
 874
 875                 iscsi_tmf_rsp(conn, hdr);
 876                 __iscsi_put_task(task);
 877                 break;
 878         case ISCSI_OP_NOOP_IN:
 879                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
 880                 if (hdr->ttt != cpu_to_be32(ISCSI_RESERVED_TAG) || datalen) {
 881                         rc = ISCSI_ERR_PROTO;
 882                         break;
 883                 }
 884                 conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 885
 886                 if (conn->ping_task != task)
 887                         /*
 888                          * If this is not in response to one of our
 889                          * nops then it must be from userspace.
 890                          */
 891                         goto recv_pdu;
 892
 893                 mod_timer(&conn->transport_timer, jiffies + conn->recv_timeout);
 894                 __iscsi_put_task(task);
 895                 break;
 896         default:
 897                 rc = ISCSI_ERR_BAD_OPCODE;
 898                 break;
 899         }
 900
 901 out:
 902         return rc;
 903 recv_pdu:
 904         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
 905                 rc = ISCSI_ERR_CONN_FAILED;
 906         __iscsi_put_task(task);
 907         return rc;
 908 }
 909 EXPORT_SYMBOL_GPL(__iscsi_complete_pdu);
 910
 911 int iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 912                        char *data, int datalen)
 913 {
 914         int rc;
 915
 916         spin_lock(&conn->session->lock);
 917         rc = __iscsi_complete_pdu(conn, hdr, data, datalen);
 918         spin_unlock(&conn->session->lock);
 919         return rc;
 920 }
 921 EXPORT_SYMBOL_GPL(iscsi_complete_pdu);
 922
 923 int iscsi_verify_itt(struct iscsi_conn *conn, itt_t itt)
 924 {
 925         struct iscsi_session *session = conn->session;
 926         uint32_t i;
 927
 928         if (itt == RESERVED_ITT)
 929                 return 0;
 930
 931         if (((__force u32)itt & ISCSI_AGE_MASK) !=
 932             (session->age << ISCSI_AGE_SHIFT)) {
 933                 iscsi_conn_printk(KERN_ERR, conn,
 934                                   "received itt %x expected session age (%x)\n",
 935                                   (__force u32)itt, session->age);
 936                 return ISCSI_ERR_BAD_ITT;
 937         }
 938
 939         i = get_itt(itt);
 940         if (i >= session->cmds_max) {
 941                 iscsi_conn_printk(KERN_ERR, conn,
 942                                   "received invalid itt index %u (max cmds "
 943                                    "%u.\n", i, session->cmds_max);
 944                 return ISCSI_ERR_BAD_ITT;
 945         }
 946         return 0;
 947 }
 948 EXPORT_SYMBOL_GPL(iscsi_verify_itt);
 949
 950 /**
 951  * iscsi_itt_to_ctask - look up ctask by itt
 952  * @conn: iscsi connection
 953  * @itt: itt
 954  *
 955  * This should be used for cmd tasks.
 956  *
 957  * The session lock must be held.
 958  */
 959 struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *conn, itt_t itt)
 960 {
 961         struct iscsi_task *task;
 962
 963         if (iscsi_verify_itt(conn, itt))
 964                 return NULL;
 965
 966         task = iscsi_itt_to_task(conn, itt);
 967         if (!task || !task->sc)
 968                 return NULL;
 969
 970         if (task->sc->SCp.phase != conn->session->age) {
 971                 iscsi_session_printk(KERN_ERR, conn->session,
 972                                   "task's session age %d, expected %d\n",
 973                                   task->sc->SCp.phase, conn->session->age);
 974                 return NULL;
 975         }
 976
 977         return task;
 978 }
 979 EXPORT_SYMBOL_GPL(iscsi_itt_to_ctask);
 980
 981 void iscsi_session_failure(struct iscsi_cls_session *cls_session,
 982                            enum iscsi_err err)
 983 {
 984         struct iscsi_session *session = cls_session->dd_data;
 985         struct iscsi_conn *conn;
 986         struct device *dev;
 987         unsigned long flags;
 988
 989         spin_lock_irqsave(&session->lock, flags);
 990         conn = session->leadconn;
 991         if (session->state == ISCSI_STATE_TERMINATE || !conn) {
 992                 spin_unlock_irqrestore(&session->lock, flags);
 993                 return;
 994         }
 995
 996         dev = get_device(&conn->cls_conn->dev);
 997         spin_unlock_irqrestore(&session->lock, flags);
 998         if (!dev)
 999                 return;
1000         /*
1001          * if the host is being removed bypass the connection
1002          * recovery initialization because we are going to kill
1003          * the session.
1004          */
1005         if (err == ISCSI_ERR_INVALID_HOST)
1006                 iscsi_conn_error_event(conn->cls_conn, err);
1007         else
1008                 iscsi_conn_failure(conn, err);
1009         put_device(dev);
1010 }
1011 EXPORT_SYMBOL_GPL(iscsi_session_failure);
1012
1013 void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err)
1014 {
1015         struct iscsi_session *session = conn->session;
1016         unsigned long flags;
1017
1018         spin_lock_irqsave(&session->lock, flags);
1019         if (session->state == ISCSI_STATE_FAILED) {
1020                 spin_unlock_irqrestore(&session->lock, flags);
1021                 return;
1022         }
1023
1024         if (conn->stop_stage == 0)
1025                 session->state = ISCSI_STATE_FAILED;
1026         spin_unlock_irqrestore(&session->lock, flags);
1027
1028         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1029         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
1030         iscsi_conn_error_event(conn->cls_conn, err);
1031 }
1032 EXPORT_SYMBOL_GPL(iscsi_conn_failure);
1033
1034 static int iscsi_check_cmdsn_window_closed(struct iscsi_conn *conn)
1035 {
1036         struct iscsi_session *session = conn->session;
1037
1038         /*
1039          * Check for iSCSI window and take care of CmdSN wrap-around
1040          */
1041         if (!iscsi_sna_lte(session->queued_cmdsn, session->max_cmdsn)) {
1042                 debug_scsi("iSCSI CmdSN closed. ExpCmdSn %u MaxCmdSN %u "
1043                            "CmdSN %u/%u\n", session->exp_cmdsn,
1044                            session->max_cmdsn, session->cmdsn,
1045                            session->queued_cmdsn);
1046                 return -ENOSPC;
1047         }
1048         return 0;
1049 }
1050
1051 static int iscsi_xmit_task(struct iscsi_conn *conn)
1052 {
1053         struct iscsi_task *task = conn->task;
1054         int rc;
1055
1056         __iscsi_get_task(task);
1057         spin_unlock_bh(&conn->session->lock);
1058         rc = conn->session->tt->xmit_task(task);
1059         spin_lock_bh(&conn->session->lock);
1060         __iscsi_put_task(task);
1061         if (!rc)
1062                 /* done with this task */
1063                 conn->task = NULL;
1064         return rc;
1065 }
1066
1067 /**
1068  * iscsi_requeue_task - requeue task to run from session workqueue
1069  * @task: task to requeue
1070  *
1071  * LLDs that need to run a task from the session workqueue should call
1072  * this. The session lock must be held. This should only be called
1073  * by software drivers.
1074  */
1075 void iscsi_requeue_task(struct iscsi_task *task)
1076 {
1077         struct iscsi_conn *conn = task->conn;
1078
1079         list_move_tail(&task->running, &conn->requeue);
1080         scsi_queue_work(conn->session->host, &conn->xmitwork);
1081 }
1082 EXPORT_SYMBOL_GPL(iscsi_requeue_task);
1083
1084 /**
1085  * iscsi_data_xmit - xmit any command into the scheduled connection
1086  * @conn: iscsi connection
1087  *
1088  * Notes:
1089  *      The function can return -EAGAIN in which case the caller must
1090  *      re-schedule it again later or recover. '0' return code means
1091  *      successful xmit.
1092  **/
1093 static int iscsi_data_xmit(struct iscsi_conn *conn)
1094 {
1095         int rc = 0;
1096
1097         spin_lock_bh(&conn->session->lock);
1098         if (unlikely(conn->suspend_tx)) {
1099                 debug_scsi("conn %d Tx suspended!\n", conn->id);
1100                 spin_unlock_bh(&conn->session->lock);
1101                 return -ENODATA;
1102         }
1103
1104         if (conn->task) {
1105                 rc = iscsi_xmit_task(conn);
1106                 if (rc)
1107                         goto again;
1108         }
1109
1110         /*
1111          * process mgmt pdus like nops before commands since we should
1112          * only have one nop-out as a ping from us and targets should not
1113          * overflow us with nop-ins
1114          */
1115 check_mgmt:
1116         while (!list_empty(&conn->mgmtqueue)) {
1117                 conn->task = list_entry(conn->mgmtqueue.next,
1118                                          struct iscsi_task, running);
1119                 if (iscsi_prep_mgmt_task(conn, conn->task)) {
1120                         __iscsi_put_task(conn->task);
1121                         conn->task = NULL;
1122                         continue;
1123                 }
1124                 rc = iscsi_xmit_task(conn);
1125                 if (rc)
1126                         goto again;
1127         }
1128
1129         /* process pending command queue */
1130         while (!list_empty(&conn->xmitqueue)) {
1131                 if (conn->tmf_state == TMF_QUEUED)
1132                         break;
1133
1134                 conn->task = list_entry(conn->xmitqueue.next,
1135                                          struct iscsi_task, running);
1136                 if (conn->session->state == ISCSI_STATE_LOGGING_OUT) {
1137                         fail_command(conn, conn->task, DID_IMM_RETRY << 16);
1138                         continue;
1139                 }
1140                 if (iscsi_prep_scsi_cmd_pdu(conn->task)) {
1141                         fail_command(conn, conn->task, DID_ABORT << 16);
1142                         continue;
1143                 }
1144                 rc = iscsi_xmit_task(conn);
1145                 if (rc)
1146                         goto again;
1147                 /*
1148                  * we could continuously get new task requests so
1149                  * we need to check the mgmt queue for nops that need to
1150                  * be sent to aviod starvation
1151                  */
1152                 if (!list_empty(&conn->mgmtqueue))
1153                         goto check_mgmt;
1154         }
1155
1156         while (!list_empty(&conn->requeue)) {
1157                 if (conn->session->fast_abort && conn->tmf_state != TMF_INITIAL)
1158                         break;
1159
1160                 /*
1161                  * we always do fastlogout - conn stop code will clean up.
1162                  */
1163                 if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
1164                         break;
1165
1166                 conn->task = list_entry(conn->requeue.next,
1167                                          struct iscsi_task, running);
1168                 conn->task->state = ISCSI_TASK_RUNNING;
1169                 list_move_tail(conn->requeue.next, &conn->run_list);
1170                 rc = iscsi_xmit_task(conn);
1171                 if (rc)
1172                         goto again;
1173                 if (!list_empty(&conn->mgmtqueue))
1174                         goto check_mgmt;
1175         }
1176         spin_unlock_bh(&conn->session->lock);
1177         return -ENODATA;
1178
1179 again:
1180         if (unlikely(conn->suspend_tx))
1181                 rc = -ENODATA;
1182         spin_unlock_bh(&conn->session->lock);
1183         return rc;
1184 }
1185
1186 static void iscsi_xmitworker(struct work_struct *work)
1187 {
1188         struct iscsi_conn *conn =
1189                 container_of(work, struct iscsi_conn, xmitwork);
1190         int rc;
1191         /*
1192          * serialize Xmit worker on a per-connection basis.
1193          */
1194         do {
1195                 rc = iscsi_data_xmit(conn);
1196         } while (rc >= 0 || rc == -EAGAIN);
1197 }
1198
1199 enum {
1200         FAILURE_BAD_HOST = 1,
1201         FAILURE_SESSION_FAILED,
1202         FAILURE_SESSION_FREED,
1203         FAILURE_WINDOW_CLOSED,
1204         FAILURE_OOM,
1205         FAILURE_SESSION_TERMINATE,
1206         FAILURE_SESSION_IN_RECOVERY,
1207         FAILURE_SESSION_RECOVERY_TIMEOUT,
1208         FAILURE_SESSION_LOGGING_OUT,
1209         FAILURE_SESSION_NOT_READY,
1210 };
1211
1212 int iscsi_queuecommand(struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *))
1213 {
1214         struct iscsi_cls_session *cls_session;
1215         struct Scsi_Host *host;
1216         int reason = 0;
1217         struct iscsi_session *session;
1218         struct iscsi_conn *conn;
1219         struct iscsi_task *task = NULL;
1220
1221         sc->scsi_done = done;
1222         sc->result = 0;
1223         sc->SCp.ptr = NULL;
1224
1225         host = sc->device->host;
1226         spin_unlock(host->host_lock);
1227
1228         cls_session = starget_to_session(scsi_target(sc->device));
1229         session = cls_session->dd_data;
1230         spin_lock(&session->lock);
1231
1232         reason = iscsi_session_chkready(cls_session);
1233         if (reason) {
1234                 sc->result = reason;
1235                 goto fault;
1236         }
1237
1238         /*
1239          * ISCSI_STATE_FAILED is a temp. state. The recovery
1240          * code will decide what is best to do with command queued
1241          * during this time
1242          */
1243         if (session->state != ISCSI_STATE_LOGGED_IN &&
1244             session->state != ISCSI_STATE_FAILED) {
1245                 /*
1246                  * to handle the race between when we set the recovery state
1247                  * and block the session we requeue here (commands could
1248                  * be entering our queuecommand while a block is starting
1249                  * up because the block code is not locked)
1250                  */
1251                 switch (session->state) {
1252                 case ISCSI_STATE_IN_RECOVERY:
1253                         reason = FAILURE_SESSION_IN_RECOVERY;
1254                         goto reject;
1255                 case ISCSI_STATE_LOGGING_OUT:
1256                         reason = FAILURE_SESSION_LOGGING_OUT;
1257                         goto reject;
1258                 case ISCSI_STATE_RECOVERY_FAILED:
1259                         reason = FAILURE_SESSION_RECOVERY_TIMEOUT;
1260                         sc->result = DID_TRANSPORT_FAILFAST << 16;
1261                         break;
1262                 case ISCSI_STATE_TERMINATE:
1263                         reason = FAILURE_SESSION_TERMINATE;
1264                         sc->result = DID_NO_CONNECT << 16;
1265                         break;
1266                 default:
1267                         reason = FAILURE_SESSION_FREED;
1268                         sc->result = DID_NO_CONNECT << 16;
1269                 }
1270                 goto fault;
1271         }
1272
1273         conn = session->leadconn;
1274         if (!conn) {
1275                 reason = FAILURE_SESSION_FREED;
1276                 sc->result = DID_NO_CONNECT << 16;
1277                 goto fault;
1278         }
1279
1280         if (iscsi_check_cmdsn_window_closed(conn)) {
1281                 reason = FAILURE_WINDOW_CLOSED;
1282                 goto reject;
1283         }
1284
1285         if (!__kfifo_get(session->cmdpool.queue, (void*)&task,
1286                          sizeof(void*))) {
1287                 reason = FAILURE_OOM;
1288                 goto reject;
1289         }
1290         sc->SCp.phase = session->age;
1291         sc->SCp.ptr = (char *)task;
1292
1293         atomic_set(&task->refcount, 1);
1294         task->state = ISCSI_TASK_PENDING;
1295         task->conn = conn;
1296         task->sc = sc;
1297         INIT_LIST_HEAD(&task->running);
1298         list_add_tail(&task->running, &conn->xmitqueue);
1299
1300         if (session->tt->caps & CAP_DATA_PATH_OFFLOAD) {
1301                 if (iscsi_prep_scsi_cmd_pdu(task)) {
1302                         sc->result = DID_ABORT << 16;
1303                         sc->scsi_done = NULL;
1304                         iscsi_complete_command(task);
1305                         goto fault;
1306                 }
1307                 if (session->tt->xmit_task(task)) {
1308                         sc->scsi_done = NULL;
1309                         iscsi_complete_command(task);
1310                         reason = FAILURE_SESSION_NOT_READY;
1311                         goto reject;
1312                 }
1313         } else
1314                 scsi_queue_work(session->host, &conn->xmitwork);
1315
1316         session->queued_cmdsn++;
1317         spin_unlock(&session->lock);
1318         spin_lock(host->host_lock);
1319         return 0;
1320
1321 reject:
1322         spin_unlock(&session->lock);
1323         debug_scsi("cmd 0x%x rejected (%d)\n", sc->cmnd[0], reason);
1324         spin_lock(host->host_lock);
1325         return SCSI_MLQUEUE_TARGET_BUSY;
1326
1327 fault:
1328         spin_unlock(&session->lock);
1329         debug_scsi("iscsi: cmd 0x%x is not queued (%d)\n", sc->cmnd[0], reason);
1330         if (!scsi_bidi_cmnd(sc))
1331                 scsi_set_resid(sc, scsi_bufflen(sc));
1332         else {
1333                 scsi_out(sc)->resid = scsi_out(sc)->length;
1334                 scsi_in(sc)->resid = scsi_in(sc)->length;
1335         }
1336         done(sc);
1337         spin_lock(host->host_lock);
1338         return 0;
1339 }
1340 EXPORT_SYMBOL_GPL(iscsi_queuecommand);
1341
1342 int iscsi_change_queue_depth(struct scsi_device *sdev, int depth)
1343 {
1344         if (depth > ISCSI_MAX_CMD_PER_LUN)
1345                 depth = ISCSI_MAX_CMD_PER_LUN;
1346         scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
1347         return sdev->queue_depth;
1348 }
1349 EXPORT_SYMBOL_GPL(iscsi_change_queue_depth);
1350
1351 void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
1352 {
1353         struct iscsi_session *session = cls_session->dd_data;
1354
1355         spin_lock_bh(&session->lock);
1356         if (session->state != ISCSI_STATE_LOGGED_IN) {
1357                 session->state = ISCSI_STATE_RECOVERY_FAILED;
1358                 if (session->leadconn)
1359                         wake_up(&session->leadconn->ehwait);
1360         }
1361         spin_unlock_bh(&session->lock);
1362 }
1363 EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
1364
1365 int iscsi_eh_target_reset(struct scsi_cmnd *sc)
1366 {
1367         struct iscsi_cls_session *cls_session;
1368         struct iscsi_session *session;
1369         struct iscsi_conn *conn;
1370
1371         cls_session = starget_to_session(scsi_target(sc->device));
1372         session = cls_session->dd_data;
1373         conn = session->leadconn;
1374
1375         mutex_lock(&session->eh_mutex);
1376         spin_lock_bh(&session->lock);
1377         if (session->state == ISCSI_STATE_TERMINATE) {
1378 failed:
1379                 debug_scsi("failing target reset: session terminated "
1380                            "[CID %d age %d]\n", conn->id, session->age);
1381                 spin_unlock_bh(&session->lock);
1382                 mutex_unlock(&session->eh_mutex);
1383                 return FAILED;
1384         }
1385
1386         spin_unlock_bh(&session->lock);
1387         mutex_unlock(&session->eh_mutex);
1388         /*
1389          * we drop the lock here but the leadconn cannot be destoyed while
1390          * we are in the scsi eh
1391          */
1392         iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1393
1394         debug_scsi("iscsi_eh_target_reset wait for relogin\n");
1395         wait_event_interruptible(conn->ehwait,
1396                                  session->state == ISCSI_STATE_TERMINATE ||
1397                                  session->state == ISCSI_STATE_LOGGED_IN ||
1398                                  session->state == ISCSI_STATE_RECOVERY_FAILED);
1399         if (signal_pending(current))
1400                 flush_signals(current);
1401
1402         mutex_lock(&session->eh_mutex);
1403         spin_lock_bh(&session->lock);
1404         if (session->state == ISCSI_STATE_LOGGED_IN)
1405                 iscsi_session_printk(KERN_INFO, session,
1406                                      "target reset succeeded\n");
1407         else
1408                 goto failed;
1409         spin_unlock_bh(&session->lock);
1410         mutex_unlock(&session->eh_mutex);
1411         return SUCCESS;
1412 }
1413 EXPORT_SYMBOL_GPL(iscsi_eh_target_reset);
1414
1415 static void iscsi_tmf_timedout(unsigned long data)
1416 {
1417         struct iscsi_conn *conn = (struct iscsi_conn *)data;
1418         struct iscsi_session *session = conn->session;
1419
1420         spin_lock(&session->lock);
1421         if (conn->tmf_state == TMF_QUEUED) {
1422                 conn->tmf_state = TMF_TIMEDOUT;
1423                 debug_scsi("tmf timedout\n");
1424                 /* unblock eh_abort() */
1425                 wake_up(&conn->ehwait);
1426         }
1427         spin_unlock(&session->lock);
1428 }
1429
1430 static int iscsi_exec_task_mgmt_fn(struct iscsi_conn *conn,
1431                                    struct iscsi_tm *hdr, int age,
1432                                    int timeout)
1433 {
1434         struct iscsi_session *session = conn->session;
1435         struct iscsi_task *task;
1436
1437         task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)hdr,
1438                                       NULL, 0);
1439         if (!task) {
1440                 spin_unlock_bh(&session->lock);
1441                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1442                 spin_lock_bh(&session->lock);
1443                 debug_scsi("tmf exec failure\n");
1444                 return -EPERM;
1445         }
1446         conn->tmfcmd_pdus_cnt++;
1447         conn->tmf_timer.expires = timeout * HZ + jiffies;
1448         conn->tmf_timer.function = iscsi_tmf_timedout;
1449         conn->tmf_timer.data = (unsigned long)conn;
1450         add_timer(&conn->tmf_timer);
1451         debug_scsi("tmf set timeout\n");
1452
1453         spin_unlock_bh(&session->lock);
1454         mutex_unlock(&session->eh_mutex);
1455
1456         /*
1457          * block eh thread until:
1458          *
1459          * 1) tmf response
1460          * 2) tmf timeout
1461          * 3) session is terminated or restarted or userspace has
1462          * given up on recovery
1463          */
1464         wait_event_interruptible(conn->ehwait, age != session->age ||
1465                                  session->state != ISCSI_STATE_LOGGED_IN ||
1466                                  conn->tmf_state != TMF_QUEUED);
1467         if (signal_pending(current))
1468                 flush_signals(current);
1469         del_timer_sync(&conn->tmf_timer);
1470
1471         mutex_lock(&session->eh_mutex);
1472         spin_lock_bh(&session->lock);
1473         /* if the session drops it will clean up the task */
1474         if (age != session->age ||
1475             session->state != ISCSI_STATE_LOGGED_IN)
1476                 return -ENOTCONN;
1477         return 0;
1478 }
1479
1480 /*
1481  * Fail commands. session lock held and recv side suspended and xmit
1482  * thread flushed
1483  */
1484 static void fail_all_commands(struct iscsi_conn *conn, unsigned lun,
1485                               int error)
1486 {
1487         struct iscsi_task *task, *tmp;
1488
1489         if (conn->task && (conn->task->sc->device->lun == lun || lun == -1))
1490                 conn->task = NULL;
1491
1492         /* flush pending */
1493         list_for_each_entry_safe(task, tmp, &conn->xmitqueue, running) {
1494                 if (lun == task->sc->device->lun || lun == -1) {
1495                         debug_scsi("failing pending sc %p itt 0x%x\n",
1496                                    task->sc, task->itt);
1497                         fail_command(conn, task, error << 16);
1498                 }
1499         }
1500
1501         list_for_each_entry_safe(task, tmp, &conn->requeue, running) {
1502                 if (lun == task->sc->device->lun || lun == -1) {
1503                         debug_scsi("failing requeued sc %p itt 0x%x\n",
1504                                    task->sc, task->itt);
1505                         fail_command(conn, task, error << 16);
1506                 }
1507         }
1508
1509         /* fail all other running */
1510         list_for_each_entry_safe(task, tmp, &conn->run_list, running) {
1511                 if (lun == task->sc->device->lun || lun == -1) {
1512                         debug_scsi("failing in progress sc %p itt 0x%x\n",
1513                                    task->sc, task->itt);
1514                         fail_command(conn, task, error << 16);
1515                 }
1516         }
1517 }
1518
1519 void iscsi_suspend_tx(struct iscsi_conn *conn)
1520 {
1521         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1522         if (!(conn->session->tt->caps & CAP_DATA_PATH_OFFLOAD))
1523                 scsi_flush_work(conn->session->host);
1524 }
1525 EXPORT_SYMBOL_GPL(iscsi_suspend_tx);
1526
1527 static void iscsi_start_tx(struct iscsi_conn *conn)
1528 {
1529         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1530         if (!(conn->session->tt->caps & CAP_DATA_PATH_OFFLOAD))
1531                 scsi_queue_work(conn->session->host, &conn->xmitwork);
1532 }
1533
1534 static enum blk_eh_timer_return iscsi_eh_cmd_timed_out(struct scsi_cmnd *scmd)
1535 {
1536         struct iscsi_cls_session *cls_session;
1537         struct iscsi_session *session;
1538         struct iscsi_conn *conn;
1539         enum blk_eh_timer_return rc = BLK_EH_NOT_HANDLED;
1540
1541         cls_session = starget_to_session(scsi_target(scmd->device));
1542         session = cls_session->dd_data;
1543
1544         debug_scsi("scsi cmd %p timedout\n", scmd);
1545
1546         spin_lock(&session->lock);
1547         if (session->state != ISCSI_STATE_LOGGED_IN) {
1548                 /*
1549                  * We are probably in the middle of iscsi recovery so let
1550                  * that complete and handle the error.
1551                  */
1552                 rc = BLK_EH_RESET_TIMER;
1553                 goto done;
1554         }
1555
1556         conn = session->leadconn;
1557         if (!conn) {
1558                 /* In the middle of shuting down */
1559                 rc = BLK_EH_RESET_TIMER;
1560                 goto done;
1561         }
1562
1563         if (!conn->recv_timeout && !conn->ping_timeout)
1564                 goto done;
1565         /*
1566          * if the ping timedout then we are in the middle of cleaning up
1567          * and can let the iscsi eh handle it
1568          */
1569         if (time_before_eq(conn->last_recv + (conn->recv_timeout * HZ) +
1570                             (conn->ping_timeout * HZ), jiffies))
1571                 rc = BLK_EH_RESET_TIMER;
1572         /*
1573          * if we are about to check the transport then give the command
1574          * more time
1575          */
1576         if (time_before_eq(conn->last_recv + (conn->recv_timeout * HZ),
1577                            jiffies))
1578                 rc = BLK_EH_RESET_TIMER;
1579         /* if in the middle of checking the transport then give us more time */
1580         if (conn->ping_task)
1581                 rc = BLK_EH_RESET_TIMER;
1582 done:
1583         spin_unlock(&session->lock);
1584         debug_scsi("return %s\n", rc == BLK_EH_RESET_TIMER ?
1585                                         "timer reset" : "nh");
1586         return rc;
1587 }
1588
1589 static void iscsi_check_transport_timeouts(unsigned long data)
1590 {
1591         struct iscsi_conn *conn = (struct iscsi_conn *)data;
1592         struct iscsi_session *session = conn->session;
1593         unsigned long recv_timeout, next_timeout = 0, last_recv;
1594
1595         spin_lock(&session->lock);
1596         if (session->state != ISCSI_STATE_LOGGED_IN)
1597                 goto done;
1598
1599         recv_timeout = conn->recv_timeout;
1600         if (!recv_timeout)
1601                 goto done;
1602
1603         recv_timeout *= HZ;
1604         last_recv = conn->last_recv;
1605         if (conn->ping_task &&
1606             time_before_eq(conn->last_ping + (conn->ping_timeout * HZ),
1607                            jiffies)) {
1608                 iscsi_conn_printk(KERN_ERR, conn, "ping timeout of %d secs "
1609                                   "expired, last rx %lu, last ping %lu, "
1610                                   "now %lu\n", conn->ping_timeout, last_recv,
1611                                   conn->last_ping, jiffies);
1612                 spin_unlock(&session->lock);
1613                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1614                 return;
1615         }
1616
1617         if (time_before_eq(last_recv + recv_timeout, jiffies)) {
1618                 /* send a ping to try to provoke some traffic */
1619                 debug_scsi("Sending nopout as ping on conn %p\n", conn);
1620                 iscsi_send_nopout(conn, NULL);
1621                 next_timeout = conn->last_ping + (conn->ping_timeout * HZ);
1622         } else
1623                 next_timeout = last_recv + recv_timeout;
1624
1625         debug_scsi("Setting next tmo %lu\n", next_timeout);
1626         mod_timer(&conn->transport_timer, next_timeout);
1627 done:
1628         spin_unlock(&session->lock);
1629 }
1630
1631 static void iscsi_prep_abort_task_pdu(struct iscsi_task *task,
1632                                       struct iscsi_tm *hdr)
1633 {
1634         memset(hdr, 0, sizeof(*hdr));
1635         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
1636         hdr->flags = ISCSI_TM_FUNC_ABORT_TASK & ISCSI_FLAG_TM_FUNC_MASK;
1637         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
1638         memcpy(hdr->lun, task->hdr->lun, sizeof(hdr->lun));
1639         hdr->rtt = task->hdr->itt;
1640         hdr->refcmdsn = task->hdr->cmdsn;
1641 }
1642
1643 int iscsi_eh_abort(struct scsi_cmnd *sc)
1644 {
1645         struct iscsi_cls_session *cls_session;
1646         struct iscsi_session *session;
1647         struct iscsi_conn *conn;
1648         struct iscsi_task *task;
1649         struct iscsi_tm *hdr;
1650         int rc, age;
1651
1652         cls_session = starget_to_session(scsi_target(sc->device));
1653         session = cls_session->dd_data;
1654
1655         mutex_lock(&session->eh_mutex);
1656         spin_lock_bh(&session->lock);
1657         /*
1658          * if session was ISCSI_STATE_IN_RECOVERY then we may not have
1659          * got the command.
1660          */
1661         if (!sc->SCp.ptr) {
1662                 debug_scsi("sc never reached iscsi layer or it completed.\n");
1663                 spin_unlock_bh(&session->lock);
1664                 mutex_unlock(&session->eh_mutex);
1665                 return SUCCESS;
1666         }
1667
1668         /*
1669          * If we are not logged in or we have started a new session
1670          * then let the host reset code handle this
1671          */
1672         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN ||
1673             sc->SCp.phase != session->age) {
1674                 spin_unlock_bh(&session->lock);
1675                 mutex_unlock(&session->eh_mutex);
1676                 return FAILED;
1677         }
1678
1679         conn = session->leadconn;
1680         conn->eh_abort_cnt++;
1681         age = session->age;
1682
1683         task = (struct iscsi_task *)sc->SCp.ptr;
1684         debug_scsi("aborting [sc %p itt 0x%x]\n", sc, task->itt);
1685
1686         /* task completed before time out */
1687         if (!task->sc) {
1688                 debug_scsi("sc completed while abort in progress\n");
1689                 goto success;
1690         }
1691
1692         if (task->state == ISCSI_TASK_PENDING) {
1693                 fail_command(conn, task, DID_ABORT << 16);
1694                 goto success;
1695         }
1696
1697         /* only have one tmf outstanding at a time */
1698         if (conn->tmf_state != TMF_INITIAL)
1699                 goto failed;
1700         conn->tmf_state = TMF_QUEUED;
1701
1702         hdr = &conn->tmhdr;
1703         iscsi_prep_abort_task_pdu(task, hdr);
1704
1705         if (iscsi_exec_task_mgmt_fn(conn, hdr, age, session->abort_timeout)) {
1706                 rc = FAILED;
1707                 goto failed;
1708         }
1709
1710         switch (conn->tmf_state) {
1711         case TMF_SUCCESS:
1712                 spin_unlock_bh(&session->lock);
1713                 /*
1714                  * stop tx side incase the target had sent a abort rsp but
1715                  * the initiator was still writing out data.
1716                  */
1717                 iscsi_suspend_tx(conn);
1718                 /*
1719                  * we do not stop the recv side because targets have been
1720                  * good and have never sent us a successful tmf response
1721                  * then sent more data for the cmd.
1722                  */
1723                 spin_lock(&session->lock);
1724                 fail_command(conn, task, DID_ABORT << 16);
1725                 conn->tmf_state = TMF_INITIAL;
1726                 spin_unlock(&session->lock);
1727                 iscsi_start_tx(conn);
1728                 goto success_unlocked;
1729         case TMF_TIMEDOUT:
1730                 spin_unlock_bh(&session->lock);
1731                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1732                 goto failed_unlocked;
1733         case TMF_NOT_FOUND:
1734                 if (!sc->SCp.ptr) {
1735                         conn->tmf_state = TMF_INITIAL;
1736                         /* task completed before tmf abort response */
1737                         debug_scsi("sc completed while abort in progress\n");
1738                         goto success;
1739                 }
1740                 /* fall through */
1741         default:
1742                 conn->tmf_state = TMF_INITIAL;
1743                 goto failed;
1744         }
1745
1746 success:
1747         spin_unlock_bh(&session->lock);
1748 success_unlocked:
1749         debug_scsi("abort success [sc %lx itt 0x%x]\n", (long)sc, task->itt);
1750         mutex_unlock(&session->eh_mutex);
1751         return SUCCESS;
1752
1753 failed:
1754         spin_unlock_bh(&session->lock);
1755 failed_unlocked:
1756         debug_scsi("abort failed [sc %p itt 0x%x]\n", sc,
1757                     task ? task->itt : 0);
1758         mutex_unlock(&session->eh_mutex);
1759         return FAILED;
1760 }
1761 EXPORT_SYMBOL_GPL(iscsi_eh_abort);
1762
1763 static void iscsi_prep_lun_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
1764 {
1765         memset(hdr, 0, sizeof(*hdr));
1766         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
1767         hdr->flags = ISCSI_TM_FUNC_LOGICAL_UNIT_RESET & ISCSI_FLAG_TM_FUNC_MASK;
1768         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
1769         int_to_scsilun(sc->device->lun, (struct scsi_lun *)hdr->lun);
1770         hdr->rtt = RESERVED_ITT;
1771 }
1772
1773 int iscsi_eh_device_reset(struct scsi_cmnd *sc)
1774 {
1775         struct iscsi_cls_session *cls_session;
1776         struct iscsi_session *session;
1777         struct iscsi_conn *conn;
1778         struct iscsi_tm *hdr;
1779         int rc = FAILED;
1780
1781         cls_session = starget_to_session(scsi_target(sc->device));
1782         session = cls_session->dd_data;
1783
1784         debug_scsi("LU Reset [sc %p lun %u]\n", sc, sc->device->lun);
1785
1786         mutex_lock(&session->eh_mutex);
1787         spin_lock_bh(&session->lock);
1788         /*
1789          * Just check if we are not logged in. We cannot check for
1790          * the phase because the reset could come from a ioctl.
1791          */
1792         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
1793                 goto unlock;
1794         conn = session->leadconn;
1795
1796         /* only have one tmf outstanding at a time */
1797         if (conn->tmf_state != TMF_INITIAL)
1798                 goto unlock;
1799         conn->tmf_state = TMF_QUEUED;
1800
1801         hdr = &conn->tmhdr;
1802         iscsi_prep_lun_reset_pdu(sc, hdr);
1803
1804         if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
1805                                     session->lu_reset_timeout)) {
1806                 rc = FAILED;
1807                 goto unlock;
1808         }
1809
1810         switch (conn->tmf_state) {
1811         case TMF_SUCCESS:
1812                 break;
1813         case TMF_TIMEDOUT:
1814                 spin_unlock_bh(&session->lock);
1815                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1816                 goto done;
1817         default:
1818                 conn->tmf_state = TMF_INITIAL;
1819                 goto unlock;
1820         }
1821
1822         rc = SUCCESS;
1823         spin_unlock_bh(&session->lock);
1824
1825         iscsi_suspend_tx(conn);
1826
1827         spin_lock_bh(&session->lock);
1828         fail_all_commands(conn, sc->device->lun, DID_ERROR);
1829         conn->tmf_state = TMF_INITIAL;
1830         spin_unlock_bh(&session->lock);
1831
1832         iscsi_start_tx(conn);
1833         goto done;
1834
1835 unlock:
1836         spin_unlock_bh(&session->lock);
1837 done:
1838         debug_scsi("iscsi_eh_device_reset %s\n",
1839                   rc == SUCCESS ? "SUCCESS" : "FAILED");
1840         mutex_unlock(&session->eh_mutex);
1841         return rc;
1842 }
1843 EXPORT_SYMBOL_GPL(iscsi_eh_device_reset);
1844
1845 /*
1846  * Pre-allocate a pool of @max items of @item_size. By default, the pool
1847  * should be accessed via kfifo_{get,put} on q->queue.
1848  * Optionally, the caller can obtain the array of object pointers
1849  * by passing in a non-NULL @items pointer
1850  */
1851 int
1852 iscsi_pool_init(struct iscsi_pool *q, int max, void ***items, int item_size)
1853 {
1854         int i, num_arrays = 1;
1855
1856         memset(q, 0, sizeof(*q));
1857
1858         q->max = max;
1859
1860         /* If the user passed an items pointer, he wants a copy of
1861          * the array. */
1862         if (items)
1863                 num_arrays++;
1864         q->pool = kzalloc(num_arrays * max * sizeof(void*), GFP_KERNEL);
1865         if (q->pool == NULL)
1866                 goto enomem;
1867
1868         q->queue = kfifo_init((void*)q->pool, max * sizeof(void*),
1869                               GFP_KERNEL, NULL);
1870         if (q->queue == ERR_PTR(-ENOMEM))
1871                 goto enomem;
1872
1873         for (i = 0; i < max; i++) {
1874                 q->pool[i] = kzalloc(item_size, GFP_KERNEL);
1875                 if (q->pool[i] == NULL) {
1876                         q->max = i;
1877                         goto enomem;
1878                 }
1879                 __kfifo_put(q->queue, (void*)&q->pool[i], sizeof(void*));
1880         }
1881
1882         if (items) {
1883                 *items = q->pool + max;
1884                 memcpy(*items, q->pool, max * sizeof(void *));
1885         }
1886
1887         return 0;
1888
1889 enomem:
1890         iscsi_pool_free(q);
1891         return -ENOMEM;
1892 }
1893 EXPORT_SYMBOL_GPL(iscsi_pool_init);
1894
1895 void iscsi_pool_free(struct iscsi_pool *q)
1896 {
1897         int i;
1898
1899         for (i = 0; i < q->max; i++)
1900                 kfree(q->pool[i]);
1901         if (q->pool)
1902                 kfree(q->pool);
1903 }
1904 EXPORT_SYMBOL_GPL(iscsi_pool_free);
1905
1906 /**
1907  * iscsi_host_add - add host to system
1908  * @shost: scsi host
1909  * @pdev: parent device
1910  *
1911  * This should be called by partial offload and software iscsi drivers
1912  * to add a host to the system.
1913  */
1914 int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev)
1915 {
1916         if (!shost->can_queue)
1917                 shost->can_queue = ISCSI_DEF_XMIT_CMDS_MAX;
1918
1919         return scsi_add_host(shost, pdev);
1920 }
1921 EXPORT_SYMBOL_GPL(iscsi_host_add);
1922
1923 /**
1924  * iscsi_host_alloc - allocate a host and driver data
1925  * @sht: scsi host template
1926  * @dd_data_size: driver host data size
1927  * @qdepth: default device queue depth
1928  *
1929  * This should be called by partial offload and software iscsi drivers.
1930  * To access the driver specific memory use the iscsi_host_priv() macro.
1931  */
1932 struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
1933                                    int dd_data_size, uint16_t qdepth)
1934 {
1935         struct Scsi_Host *shost;
1936         struct iscsi_host *ihost;
1937
1938         shost = scsi_host_alloc(sht, sizeof(struct iscsi_host) + dd_data_size);
1939         if (!shost)
1940                 return NULL;
1941         shost->transportt->eh_timed_out = iscsi_eh_cmd_timed_out;
1942
1943         if (qdepth > ISCSI_MAX_CMD_PER_LUN || qdepth < 1) {
1944                 if (qdepth != 0)
1945                         printk(KERN_ERR "iscsi: invalid queue depth of %d. "
1946                                "Queue depth must be between 1 and %d.\n",
1947                                qdepth, ISCSI_MAX_CMD_PER_LUN);
1948                 qdepth = ISCSI_DEF_CMD_PER_LUN;
1949         }
1950         shost->cmd_per_lun = qdepth;
1951
1952         ihost = shost_priv(shost);
1953         spin_lock_init(&ihost->lock);
1954         ihost->state = ISCSI_HOST_SETUP;
1955         ihost->num_sessions = 0;
1956         init_waitqueue_head(&ihost->session_removal_wq);
1957         return shost;
1958 }
1959 EXPORT_SYMBOL_GPL(iscsi_host_alloc);
1960
1961 static void iscsi_notify_host_removed(struct iscsi_cls_session *cls_session)
1962 {
1963         iscsi_session_failure(cls_session, ISCSI_ERR_INVALID_HOST);
1964 }
1965
1966 /**
1967  * iscsi_host_remove - remove host and sessions
1968  * @shost: scsi host
1969  *
1970  * If there are any sessions left, this will initiate the removal and wait
1971  * for the completion.
1972  */
1973 void iscsi_host_remove(struct Scsi_Host *shost)
1974 {
1975         struct iscsi_host *ihost = shost_priv(shost);
1976         unsigned long flags;
1977
1978         spin_lock_irqsave(&ihost->lock, flags);
1979         ihost->state = ISCSI_HOST_REMOVED;
1980         spin_unlock_irqrestore(&ihost->lock, flags);
1981
1982         iscsi_host_for_each_session(shost, iscsi_notify_host_removed);
1983         wait_event_interruptible(ihost->session_removal_wq,
1984                                  ihost->num_sessions == 0);
1985         if (signal_pending(current))
1986                 flush_signals(current);
1987
1988         scsi_remove_host(shost);
1989 }
1990 EXPORT_SYMBOL_GPL(iscsi_host_remove);
1991
1992 void iscsi_host_free(struct Scsi_Host *shost)
1993 {
1994         struct iscsi_host *ihost = shost_priv(shost);
1995
1996         kfree(ihost->netdev);
1997         kfree(ihost->hwaddress);
1998         kfree(ihost->initiatorname);
1999         scsi_host_put(shost);
2000 }
2001 EXPORT_SYMBOL_GPL(iscsi_host_free);
2002
2003 static void iscsi_host_dec_session_cnt(struct Scsi_Host *shost)
2004 {
2005         struct iscsi_host *ihost = shost_priv(shost);
2006         unsigned long flags;
2007
2008         shost = scsi_host_get(shost);
2009         if (!shost) {
2010                 printk(KERN_ERR "Invalid state. Cannot notify host removal "
2011                       "of session teardown event because host already "
2012                       "removed.\n");
2013                 return;
2014         }
2015
2016         spin_lock_irqsave(&ihost->lock, flags);
2017         ihost->num_sessions--;
2018         if (ihost->num_sessions == 0)
2019                 wake_up(&ihost->session_removal_wq);
2020         spin_unlock_irqrestore(&ihost->lock, flags);
2021         scsi_host_put(shost);
2022 }
2023
2024 /**
2025  * iscsi_session_setup - create iscsi cls session and host and session
2026  * @iscsit: iscsi transport template
2027  * @shost: scsi host
2028  * @cmds_max: session can queue
2029  * @cmd_task_size: LLD task private data size
2030  * @initial_cmdsn: initial CmdSN
2031  *
2032  * This can be used by software iscsi_transports that allocate
2033  * a session per scsi host.
2034  *
2035  * Callers should set cmds_max to the largest total numer (mgmt + scsi) of
2036  * tasks they support. The iscsi layer reserves ISCSI_MGMT_CMDS_MAX tasks
2037  * for nop handling and login/logout requests.
2038  */
2039 struct iscsi_cls_session *
2040 iscsi_session_setup(struct iscsi_transport *iscsit, struct Scsi_Host *shost,
2041                     uint16_t cmds_max, int cmd_task_size,
2042                     uint32_t initial_cmdsn, unsigned int id)
2043 {
2044         struct iscsi_host *ihost = shost_priv(shost);
2045         struct iscsi_session *session;
2046         struct iscsi_cls_session *cls_session;
2047         int cmd_i, scsi_cmds, total_cmds = cmds_max;
2048         unsigned long flags;
2049
2050         spin_lock_irqsave(&ihost->lock, flags);
2051         if (ihost->state == ISCSI_HOST_REMOVED) {
2052                 spin_unlock_irqrestore(&ihost->lock, flags);
2053                 return NULL;
2054         }
2055         ihost->num_sessions++;
2056         spin_unlock_irqrestore(&ihost->lock, flags);
2057
2058         if (!total_cmds)
2059                 total_cmds = ISCSI_DEF_XMIT_CMDS_MAX;
2060         /*
2061          * The iscsi layer needs some tasks for nop handling and tmfs,
2062          * so the cmds_max must at least be greater than ISCSI_MGMT_CMDS_MAX
2063          * + 1 command for scsi IO.
2064          */
2065         if (total_cmds < ISCSI_TOTAL_CMDS_MIN) {
2066                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2067                        "must be a power of two that is at least %d.\n",
2068                        total_cmds, ISCSI_TOTAL_CMDS_MIN);
2069                 goto dec_session_count;
2070         }
2071
2072         if (total_cmds > ISCSI_TOTAL_CMDS_MAX) {
2073                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2074                        "must be a power of 2 less than or equal to %d.\n",
2075                        cmds_max, ISCSI_TOTAL_CMDS_MAX);
2076                 total_cmds = ISCSI_TOTAL_CMDS_MAX;
2077         }
2078
2079         if (!is_power_of_2(total_cmds)) {
2080                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2081                        "must be a power of 2.\n", total_cmds);
2082                 total_cmds = rounddown_pow_of_two(total_cmds);
2083                 if (total_cmds < ISCSI_TOTAL_CMDS_MIN)
2084                         return NULL;
2085                 printk(KERN_INFO "iscsi: Rounding can_queue to %d.\n",
2086                        total_cmds);
2087         }
2088         scsi_cmds = total_cmds - ISCSI_MGMT_CMDS_MAX;
2089
2090         cls_session = iscsi_alloc_session(shost, iscsit,
2091                                           sizeof(struct iscsi_session));
2092         if (!cls_session)
2093                 goto dec_session_count;
2094         session = cls_session->dd_data;
2095         session->cls_session = cls_session;
2096         session->host = shost;
2097         session->state = ISCSI_STATE_FREE;
2098         session->fast_abort = 1;
2099         session->lu_reset_timeout = 15;
2100         session->abort_timeout = 10;
2101         session->scsi_cmds_max = scsi_cmds;
2102         session->cmds_max = total_cmds;
2103         session->queued_cmdsn = session->cmdsn = initial_cmdsn;
2104         session->exp_cmdsn = initial_cmdsn + 1;
2105         session->max_cmdsn = initial_cmdsn + 1;
2106         session->max_r2t = 1;
2107         session->tt = iscsit;
2108         mutex_init(&session->eh_mutex);
2109         spin_lock_init(&session->lock);
2110
2111         /* initialize SCSI PDU commands pool */
2112         if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
2113                             (void***)&session->cmds,
2114                             cmd_task_size + sizeof(struct iscsi_task)))
2115                 goto cmdpool_alloc_fail;
2116
2117         /* pre-format cmds pool with ITT */
2118         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
2119                 struct iscsi_task *task = session->cmds[cmd_i];
2120
2121                 if (cmd_task_size)
2122                         task->dd_data = &task[1];
2123                 task->itt = cmd_i;
2124                 INIT_LIST_HEAD(&task->running);
2125         }
2126
2127         if (!try_module_get(iscsit->owner))
2128                 goto module_get_fail;
2129
2130         if (iscsi_add_session(cls_session, id))
2131                 goto cls_session_fail;
2132
2133         return cls_session;
2134
2135 cls_session_fail:
2136         module_put(iscsit->owner);
2137 module_get_fail:
2138         iscsi_pool_free(&session->cmdpool);
2139 cmdpool_alloc_fail:
2140         iscsi_free_session(cls_session);
2141 dec_session_count:
2142         iscsi_host_dec_session_cnt(shost);
2143         return NULL;
2144 }
2145 EXPORT_SYMBOL_GPL(iscsi_session_setup);
2146
2147 /**
2148  * iscsi_session_teardown - destroy session, host, and cls_session
2149  * @cls_session: iscsi session
2150  *
2151  * The driver must have called iscsi_remove_session before
2152  * calling this.
2153  */
2154 void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
2155 {
2156         struct iscsi_session *session = cls_session->dd_data;
2157         struct module *owner = cls_session->transport->owner;
2158         struct Scsi_Host *shost = session->host;
2159
2160         iscsi_pool_free(&session->cmdpool);
2161
2162         kfree(session->password);
2163         kfree(session->password_in);
2164         kfree(session->username);
2165         kfree(session->username_in);
2166         kfree(session->targetname);
2167         kfree(session->initiatorname);
2168         kfree(session->ifacename);
2169
2170         iscsi_destroy_session(cls_session);
2171         iscsi_host_dec_session_cnt(shost);
2172         module_put(owner);
2173 }
2174 EXPORT_SYMBOL_GPL(iscsi_session_teardown);
2175
2176 /**
2177  * iscsi_conn_setup - create iscsi_cls_conn and iscsi_conn
2178  * @cls_session: iscsi_cls_session
2179  * @dd_size: private driver data size
2180  * @conn_idx: cid
2181  */
2182 struct iscsi_cls_conn *
2183 iscsi_conn_setup(struct iscsi_cls_session *cls_session, int dd_size,
2184                  uint32_t conn_idx)
2185 {
2186         struct iscsi_session *session = cls_session->dd_data;
2187         struct iscsi_conn *conn;
2188         struct iscsi_cls_conn *cls_conn;
2189         char *data;
2190
2191         cls_conn = iscsi_create_conn(cls_session, sizeof(*conn) + dd_size,
2192                                      conn_idx);
2193         if (!cls_conn)
2194                 return NULL;
2195         conn = cls_conn->dd_data;
2196         memset(conn, 0, sizeof(*conn) + dd_size);
2197
2198         conn->dd_data = cls_conn->dd_data + sizeof(*conn);
2199         conn->session = session;
2200         conn->cls_conn = cls_conn;
2201         conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
2202         conn->id = conn_idx;
2203         conn->exp_statsn = 0;
2204         conn->tmf_state = TMF_INITIAL;
2205
2206         init_timer(&conn->transport_timer);
2207         conn->transport_timer.data = (unsigned long)conn;
2208         conn->transport_timer.function = iscsi_check_transport_timeouts;
2209
2210         INIT_LIST_HEAD(&conn->run_list);
2211         INIT_LIST_HEAD(&conn->mgmt_run_list);
2212         INIT_LIST_HEAD(&conn->mgmtqueue);
2213         INIT_LIST_HEAD(&conn->xmitqueue);
2214         INIT_LIST_HEAD(&conn->requeue);
2215         INIT_WORK(&conn->xmitwork, iscsi_xmitworker);
2216
2217         /* allocate login_task used for the login/text sequences */
2218         spin_lock_bh(&session->lock);
2219         if (!__kfifo_get(session->cmdpool.queue,
2220                          (void*)&conn->login_task,
2221                          sizeof(void*))) {
2222                 spin_unlock_bh(&session->lock);
2223                 goto login_task_alloc_fail;
2224         }
2225         spin_unlock_bh(&session->lock);
2226
2227         data = kmalloc(ISCSI_DEF_MAX_RECV_SEG_LEN, GFP_KERNEL);
2228         if (!data)
2229                 goto login_task_data_alloc_fail;
2230         conn->login_task->data = conn->data = data;
2231
2232         init_timer(&conn->tmf_timer);
2233         init_waitqueue_head(&conn->ehwait);
2234
2235         return cls_conn;
2236
2237 login_task_data_alloc_fail:
2238         __kfifo_put(session->cmdpool.queue, (void*)&conn->login_task,
2239                     sizeof(void*));
2240 login_task_alloc_fail:
2241         iscsi_destroy_conn(cls_conn);
2242         return NULL;
2243 }
2244 EXPORT_SYMBOL_GPL(iscsi_conn_setup);
2245
2246 /**
2247  * iscsi_conn_teardown - teardown iscsi connection
2248  * cls_conn: iscsi class connection
2249  *
2250  * TODO: we may need to make this into a two step process
2251  * like scsi-mls remove + put host
2252  */
2253 void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
2254 {
2255         struct iscsi_conn *conn = cls_conn->dd_data;
2256         struct iscsi_session *session = conn->session;
2257         unsigned long flags;
2258
2259         del_timer_sync(&conn->transport_timer);
2260
2261         spin_lock_bh(&session->lock);
2262         conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
2263         if (session->leadconn == conn) {
2264                 /*
2265                  * leading connection? then give up on recovery.
2266                  */
2267                 session->state = ISCSI_STATE_TERMINATE;
2268                 wake_up(&conn->ehwait);
2269         }
2270         spin_unlock_bh(&session->lock);
2271
2272         /*
2273          * Block until all in-progress commands for this connection
2274          * time out or fail.
2275          */
2276         for (;;) {
2277                 spin_lock_irqsave(session->host->host_lock, flags);
2278                 if (!session->host->host_busy) { /* OK for ERL == 0 */
2279                         spin_unlock_irqrestore(session->host->host_lock, flags);
2280                         break;
2281                 }
2282                 spin_unlock_irqrestore(session->host->host_lock, flags);
2283                 msleep_interruptible(500);
2284                 iscsi_conn_printk(KERN_INFO, conn, "iscsi conn_destroy(): "
2285                                   "host_busy %d host_failed %d\n",
2286                                   session->host->host_busy,
2287                                   session->host->host_failed);
2288                 /*
2289                  * force eh_abort() to unblock
2290                  */
2291                 wake_up(&conn->ehwait);
2292         }
2293
2294         /* flush queued up work because we free the connection below */
2295         iscsi_suspend_tx(conn);
2296
2297         spin_lock_bh(&session->lock);
2298         kfree(conn->data);
2299         kfree(conn->persistent_address);
2300         __kfifo_put(session->cmdpool.queue, (void*)&conn->login_task,
2301                     sizeof(void*));
2302         if (session->leadconn == conn)
2303                 session->leadconn = NULL;
2304         spin_unlock_bh(&session->lock);
2305
2306         iscsi_destroy_conn(cls_conn);
2307 }
2308 EXPORT_SYMBOL_GPL(iscsi_conn_teardown);
2309
2310 int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
2311 {
2312         struct iscsi_conn *conn = cls_conn->dd_data;
2313         struct iscsi_session *session = conn->session;
2314
2315         if (!session) {
2316                 iscsi_conn_printk(KERN_ERR, conn,
2317                                   "can't start unbound connection\n");
2318                 return -EPERM;
2319         }
2320
2321         if ((session->imm_data_en || !session->initial_r2t_en) &&
2322              session->first_burst > session->max_burst) {
2323                 iscsi_conn_printk(KERN_INFO, conn, "invalid burst lengths: "
2324                                   "first_burst %d max_burst %d\n",
2325                                   session->first_burst, session->max_burst);
2326                 return -EINVAL;
2327         }
2328
2329         if (conn->ping_timeout && !conn->recv_timeout) {
2330                 iscsi_conn_printk(KERN_ERR, conn, "invalid recv timeout of "
2331                                   "zero. Using 5 seconds\n.");
2332                 conn->recv_timeout = 5;
2333         }
2334
2335         if (conn->recv_timeout && !conn->ping_timeout) {
2336                 iscsi_conn_printk(KERN_ERR, conn, "invalid ping timeout of "
2337                                   "zero. Using 5 seconds.\n");
2338                 conn->ping_timeout = 5;
2339         }
2340
2341         spin_lock_bh(&session->lock);
2342         conn->c_stage = ISCSI_CONN_STARTED;
2343         session->state = ISCSI_STATE_LOGGED_IN;
2344         session->queued_cmdsn = session->cmdsn;
2345
2346         conn->last_recv = jiffies;
2347         conn->last_ping = jiffies;
2348         if (conn->recv_timeout && conn->ping_timeout)
2349                 mod_timer(&conn->transport_timer,
2350                           jiffies + (conn->recv_timeout * HZ));
2351
2352         switch(conn->stop_stage) {
2353         case STOP_CONN_RECOVER:
2354                 /*
2355                  * unblock eh_abort() if it is blocked. re-try all
2356                  * commands after successful recovery
2357                  */
2358                 conn->stop_stage = 0;
2359                 conn->tmf_state = TMF_INITIAL;
2360                 session->age++;
2361                 if (session->age == 16)
2362                         session->age = 0;
2363                 break;
2364         case STOP_CONN_TERM:
2365                 conn->stop_stage = 0;
2366                 break;
2367         default:
2368                 break;
2369         }
2370         spin_unlock_bh(&session->lock);
2371
2372         iscsi_unblock_session(session->cls_session);
2373         wake_up(&conn->ehwait);
2374         return 0;
2375 }
2376 EXPORT_SYMBOL_GPL(iscsi_conn_start);
2377
2378 static void
2379 flush_control_queues(struct iscsi_session *session, struct iscsi_conn *conn)
2380 {
2381         struct iscsi_task *task, *tmp;
2382
2383         /* handle pending */
2384         list_for_each_entry_safe(task, tmp, &conn->mgmtqueue, running) {
2385                 debug_scsi("flushing pending mgmt task itt 0x%x\n", task->itt);
2386                 /* release ref from prep task */
2387                 __iscsi_put_task(task);
2388         }
2389
2390         /* handle running */
2391         list_for_each_entry_safe(task, tmp, &conn->mgmt_run_list, running) {
2392                 debug_scsi("flushing running mgmt task itt 0x%x\n", task->itt);
2393                 /* release ref from prep task */
2394                 __iscsi_put_task(task);
2395         }
2396
2397         conn->task = NULL;
2398 }
2399
2400 static void iscsi_start_session_recovery(struct iscsi_session *session,
2401                                          struct iscsi_conn *conn, int flag)
2402 {
2403         int old_stop_stage;
2404
2405         del_timer_sync(&conn->transport_timer);
2406
2407         mutex_lock(&session->eh_mutex);
2408         spin_lock_bh(&session->lock);
2409         if (conn->stop_stage == STOP_CONN_TERM) {
2410                 spin_unlock_bh(&session->lock);
2411                 mutex_unlock(&session->eh_mutex);
2412                 return;
2413         }
2414
2415         /*
2416          * When this is called for the in_login state, we only want to clean
2417          * up the login task and connection. We do not need to block and set
2418          * the recovery state again
2419          */
2420         if (flag == STOP_CONN_TERM)
2421                 session->state = ISCSI_STATE_TERMINATE;
2422         else if (conn->stop_stage != STOP_CONN_RECOVER)
2423                 session->state = ISCSI_STATE_IN_RECOVERY;
2424
2425         old_stop_stage = conn->stop_stage;
2426         conn->stop_stage = flag;
2427         conn->c_stage = ISCSI_CONN_STOPPED;
2428         spin_unlock_bh(&session->lock);
2429
2430         iscsi_suspend_tx(conn);
2431         /*
2432          * for connection level recovery we should not calculate
2433          * header digest. conn->hdr_size used for optimization
2434          * in hdr_extract() and will be re-negotiated at
2435          * set_param() time.
2436          */
2437         if (flag == STOP_CONN_RECOVER) {
2438                 conn->hdrdgst_en = 0;
2439                 conn->datadgst_en = 0;
2440                 if (session->state == ISCSI_STATE_IN_RECOVERY &&
2441                     old_stop_stage != STOP_CONN_RECOVER) {
2442                         debug_scsi("blocking session\n");
2443                         iscsi_block_session(session->cls_session);
2444                 }
2445         }
2446
2447         /*
2448          * flush queues.
2449          */
2450         spin_lock_bh(&session->lock);
2451         if (flag == STOP_CONN_RECOVER)
2452                 fail_all_commands(conn, -1, DID_TRANSPORT_DISRUPTED);
2453         else
2454                 fail_all_commands(conn, -1, DID_ERROR);
2455         flush_control_queues(session, conn);
2456         spin_unlock_bh(&session->lock);
2457         mutex_unlock(&session->eh_mutex);
2458 }
2459
2460 void iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
2461 {
2462         struct iscsi_conn *conn = cls_conn->dd_data;
2463         struct iscsi_session *session = conn->session;
2464
2465         switch (flag) {
2466         case STOP_CONN_RECOVER:
2467         case STOP_CONN_TERM:
2468                 iscsi_start_session_recovery(session, conn, flag);
2469                 break;
2470         default:
2471                 iscsi_conn_printk(KERN_ERR, conn,
2472                                   "invalid stop flag %d\n", flag);
2473         }
2474 }
2475 EXPORT_SYMBOL_GPL(iscsi_conn_stop);
2476
2477 int iscsi_conn_bind(struct iscsi_cls_session *cls_session,
2478                     struct iscsi_cls_conn *cls_conn, int is_leading)
2479 {
2480         struct iscsi_session *session = cls_session->dd_data;
2481         struct iscsi_conn *conn = cls_conn->dd_data;
2482
2483         spin_lock_bh(&session->lock);
2484         if (is_leading)
2485                 session->leadconn = conn;
2486         spin_unlock_bh(&session->lock);
2487
2488         /*
2489          * Unblock xmitworker(), Login Phase will pass through.
2490          */
2491         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
2492         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
2493         return 0;
2494 }
2495 EXPORT_SYMBOL_GPL(iscsi_conn_bind);
2496
2497
2498 int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
2499                     enum iscsi_param param, char *buf, int buflen)
2500 {
2501         struct iscsi_conn *conn = cls_conn->dd_data;
2502         struct iscsi_session *session = conn->session;
2503         uint32_t value;
2504
2505         switch(param) {
2506         case ISCSI_PARAM_FAST_ABORT:
2507                 sscanf(buf, "%d", &session->fast_abort);
2508                 break;
2509         case ISCSI_PARAM_ABORT_TMO:
2510                 sscanf(buf, "%d", &session->abort_timeout);
2511                 break;
2512         case ISCSI_PARAM_LU_RESET_TMO:
2513                 sscanf(buf, "%d", &session->lu_reset_timeout);
2514                 break;
2515         case ISCSI_PARAM_PING_TMO:
2516                 sscanf(buf, "%d", &conn->ping_timeout);
2517                 break;
2518         case ISCSI_PARAM_RECV_TMO:
2519                 sscanf(buf, "%d", &conn->recv_timeout);
2520                 break;
2521         case ISCSI_PARAM_MAX_RECV_DLENGTH:
2522                 sscanf(buf, "%d", &conn->max_recv_dlength);
2523                 break;
2524         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
2525                 sscanf(buf, "%d", &conn->max_xmit_dlength);
2526                 break;
2527         case ISCSI_PARAM_HDRDGST_EN:
2528                 sscanf(buf, "%d", &conn->hdrdgst_en);
2529                 break;
2530         case ISCSI_PARAM_DATADGST_EN:
2531                 sscanf(buf, "%d", &conn->datadgst_en);
2532                 break;
2533         case ISCSI_PARAM_INITIAL_R2T_EN:
2534                 sscanf(buf, "%d", &session->initial_r2t_en);
2535                 break;
2536         case ISCSI_PARAM_MAX_R2T:
2537                 sscanf(buf, "%d", &session->max_r2t);
2538                 break;
2539         case ISCSI_PARAM_IMM_DATA_EN:
2540                 sscanf(buf, "%d", &session->imm_data_en);
2541                 break;
2542         case ISCSI_PARAM_FIRST_BURST:
2543                 sscanf(buf, "%d", &session->first_burst);
2544                 break;
2545         case ISCSI_PARAM_MAX_BURST:
2546                 sscanf(buf, "%d", &session->max_burst);
2547                 break;
2548         case ISCSI_PARAM_PDU_INORDER_EN:
2549                 sscanf(buf, "%d", &session->pdu_inorder_en);
2550                 break;
2551         case ISCSI_PARAM_DATASEQ_INORDER_EN:
2552                 sscanf(buf, "%d", &session->dataseq_inorder_en);
2553                 break;
2554         case ISCSI_PARAM_ERL:
2555                 sscanf(buf, "%d", &session->erl);
2556                 break;
2557         case ISCSI_PARAM_IFMARKER_EN:
2558                 sscanf(buf, "%d", &value);
2559                 BUG_ON(value);
2560                 break;
2561         case ISCSI_PARAM_OFMARKER_EN:
2562                 sscanf(buf, "%d", &value);
2563                 BUG_ON(value);
2564                 break;
2565         case ISCSI_PARAM_EXP_STATSN:
2566                 sscanf(buf, "%u", &conn->exp_statsn);
2567                 break;
2568         case ISCSI_PARAM_USERNAME:
2569                 kfree(session->username);
2570                 session->username = kstrdup(buf, GFP_KERNEL);
2571                 if (!session->username)
2572                         return -ENOMEM;
2573                 break;
2574         case ISCSI_PARAM_USERNAME_IN:
2575                 kfree(session->username_in);
2576                 session->username_in = kstrdup(buf, GFP_KERNEL);
2577                 if (!session->username_in)
2578                         return -ENOMEM;
2579                 break;
2580         case ISCSI_PARAM_PASSWORD:
2581                 kfree(session->password);
2582                 session->password = kstrdup(buf, GFP_KERNEL);
2583                 if (!session->password)
2584                         return -ENOMEM;
2585                 break;
2586         case ISCSI_PARAM_PASSWORD_IN:
2587                 kfree(session->password_in);
2588                 session->password_in = kstrdup(buf, GFP_KERNEL);
2589                 if (!session->password_in)
2590                         return -ENOMEM;
2591                 break;
2592         case ISCSI_PARAM_TARGET_NAME:
2593                 /* this should not change between logins */
2594                 if (session->targetname)
2595                         break;
2596
2597                 session->targetname = kstrdup(buf, GFP_KERNEL);
2598                 if (!session->targetname)
2599                         return -ENOMEM;
2600                 break;
2601         case ISCSI_PARAM_TPGT:
2602                 sscanf(buf, "%d", &session->tpgt);
2603                 break;
2604         case ISCSI_PARAM_PERSISTENT_PORT:
2605                 sscanf(buf, "%d", &conn->persistent_port);
2606                 break;
2607         case ISCSI_PARAM_PERSISTENT_ADDRESS:
2608                 /*
2609                  * this is the address returned in discovery so it should
2610                  * not change between logins.
2611                  */
2612                 if (conn->persistent_address)
2613                         break;
2614
2615                 conn->persistent_address = kstrdup(buf, GFP_KERNEL);
2616                 if (!conn->persistent_address)
2617                         return -ENOMEM;
2618                 break;
2619         case ISCSI_PARAM_IFACE_NAME:
2620                 if (!session->ifacename)
2621                         session->ifacename = kstrdup(buf, GFP_KERNEL);
2622                 break;
2623         case ISCSI_PARAM_INITIATOR_NAME:
2624                 if (!session->initiatorname)
2625                         session->initiatorname = kstrdup(buf, GFP_KERNEL);
2626                 break;
2627         default:
2628                 return -ENOSYS;
2629         }
2630
2631         return 0;
2632 }
2633 EXPORT_SYMBOL_GPL(iscsi_set_param);
2634
2635 int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
2636                             enum iscsi_param param, char *buf)
2637 {
2638         struct iscsi_session *session = cls_session->dd_data;
2639         int len;
2640
2641         switch(param) {
2642         case ISCSI_PARAM_FAST_ABORT:
2643                 len = sprintf(buf, "%d\n", session->fast_abort);
2644                 break;
2645         case ISCSI_PARAM_ABORT_TMO:
2646                 len = sprintf(buf, "%d\n", session->abort_timeout);
2647                 break;
2648         case ISCSI_PARAM_LU_RESET_TMO:
2649                 len = sprintf(buf, "%d\n", session->lu_reset_timeout);
2650                 break;
2651         case ISCSI_PARAM_INITIAL_R2T_EN:
2652                 len = sprintf(buf, "%d\n", session->initial_r2t_en);
2653                 break;
2654         case ISCSI_PARAM_MAX_R2T:
2655                 len = sprintf(buf, "%hu\n", session->max_r2t);
2656                 break;
2657         case ISCSI_PARAM_IMM_DATA_EN:
2658                 len = sprintf(buf, "%d\n", session->imm_data_en);
2659                 break;
2660         case ISCSI_PARAM_FIRST_BURST:
2661                 len = sprintf(buf, "%u\n", session->first_burst);
2662                 break;
2663         case ISCSI_PARAM_MAX_BURST:
2664                 len = sprintf(buf, "%u\n", session->max_burst);
2665                 break;
2666         case ISCSI_PARAM_PDU_INORDER_EN:
2667                 len = sprintf(buf, "%d\n", session->pdu_inorder_en);
2668                 break;
2669         case ISCSI_PARAM_DATASEQ_INORDER_EN:
2670                 len = sprintf(buf, "%d\n", session->dataseq_inorder_en);
2671                 break;
2672         case ISCSI_PARAM_ERL:
2673                 len = sprintf(buf, "%d\n", session->erl);
2674                 break;
2675         case ISCSI_PARAM_TARGET_NAME:
2676                 len = sprintf(buf, "%s\n", session->targetname);
2677                 break;
2678         case ISCSI_PARAM_TPGT:
2679                 len = sprintf(buf, "%d\n", session->tpgt);
2680                 break;
2681         case ISCSI_PARAM_USERNAME:
2682                 len = sprintf(buf, "%s\n", session->username);
2683                 break;
2684         case ISCSI_PARAM_USERNAME_IN:
2685                 len = sprintf(buf, "%s\n", session->username_in);
2686                 break;
2687         case ISCSI_PARAM_PASSWORD:
2688                 len = sprintf(buf, "%s\n", session->password);
2689                 break;
2690         case ISCSI_PARAM_PASSWORD_IN:
2691                 len = sprintf(buf, "%s\n", session->password_in);
2692                 break;
2693         case ISCSI_PARAM_IFACE_NAME:
2694                 len = sprintf(buf, "%s\n", session->ifacename);
2695                 break;
2696         case ISCSI_PARAM_INITIATOR_NAME:
2697                 if (!session->initiatorname)
2698                         len = sprintf(buf, "%s\n", "unknown");
2699                 else
2700                         len = sprintf(buf, "%s\n", session->initiatorname);
2701                 break;
2702         default:
2703                 return -ENOSYS;
2704         }
2705
2706         return len;
2707 }
2708 EXPORT_SYMBOL_GPL(iscsi_session_get_param);
2709
2710 int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
2711                          enum iscsi_param param, char *buf)
2712 {
2713         struct iscsi_conn *conn = cls_conn->dd_data;
2714         int len;
2715
2716         switch(param) {
2717         case ISCSI_PARAM_PING_TMO:
2718                 len = sprintf(buf, "%u\n", conn->ping_timeout);
2719                 break;
2720         case ISCSI_PARAM_RECV_TMO:
2721                 len = sprintf(buf, "%u\n", conn->recv_timeout);
2722                 break;
2723         case ISCSI_PARAM_MAX_RECV_DLENGTH:
2724                 len = sprintf(buf, "%u\n", conn->max_recv_dlength);
2725                 break;
2726         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
2727                 len = sprintf(buf, "%u\n", conn->max_xmit_dlength);
2728                 break;
2729         case ISCSI_PARAM_HDRDGST_EN:
2730                 len = sprintf(buf, "%d\n", conn->hdrdgst_en);
2731                 break;
2732         case ISCSI_PARAM_DATADGST_EN:
2733                 len = sprintf(buf, "%d\n", conn->datadgst_en);
2734                 break;
2735         case ISCSI_PARAM_IFMARKER_EN:
2736                 len = sprintf(buf, "%d\n", conn->ifmarker_en);
2737                 break;
2738         case ISCSI_PARAM_OFMARKER_EN:
2739                 len = sprintf(buf, "%d\n", conn->ofmarker_en);
2740                 break;
2741         case ISCSI_PARAM_EXP_STATSN:
2742                 len = sprintf(buf, "%u\n", conn->exp_statsn);
2743                 break;
2744         case ISCSI_PARAM_PERSISTENT_PORT:
2745                 len = sprintf(buf, "%d\n", conn->persistent_port);
2746                 break;
2747         case ISCSI_PARAM_PERSISTENT_ADDRESS:
2748                 len = sprintf(buf, "%s\n", conn->persistent_address);
2749                 break;
2750         default:
2751                 return -ENOSYS;
2752         }
2753
2754         return len;
2755 }
2756 EXPORT_SYMBOL_GPL(iscsi_conn_get_param);
2757
2758 int iscsi_host_get_param(struct Scsi_Host *shost, enum iscsi_host_param param,
2759                          char *buf)
2760 {
2761         struct iscsi_host *ihost = shost_priv(shost);
2762         int len;
2763
2764         switch (param) {
2765         case ISCSI_HOST_PARAM_NETDEV_NAME:
2766                 if (!ihost->netdev)
2767                         len = sprintf(buf, "%s\n", "default");
2768                 else
2769                         len = sprintf(buf, "%s\n", ihost->netdev);
2770                 break;
2771         case ISCSI_HOST_PARAM_HWADDRESS:
2772                 if (!ihost->hwaddress)
2773                         len = sprintf(buf, "%s\n", "default");
2774                 else
2775                         len = sprintf(buf, "%s\n", ihost->hwaddress);
2776                 break;
2777         case ISCSI_HOST_PARAM_INITIATOR_NAME:
2778                 if (!ihost->initiatorname)
2779                         len = sprintf(buf, "%s\n", "unknown");
2780                 else
2781                         len = sprintf(buf, "%s\n", ihost->initiatorname);
2782                 break;
2783         case ISCSI_HOST_PARAM_IPADDRESS:
2784                 if (!strlen(ihost->local_address))
2785                         len = sprintf(buf, "%s\n", "unknown");
2786                 else
2787                         len = sprintf(buf, "%s\n",
2788                                       ihost->local_address);
2789                 break;
2790         default:
2791                 return -ENOSYS;
2792         }
2793
2794         return len;
2795 }
2796 EXPORT_SYMBOL_GPL(iscsi_host_get_param);
2797
2798 int iscsi_host_set_param(struct Scsi_Host *shost, enum iscsi_host_param param,
2799                          char *buf, int buflen)
2800 {
2801         struct iscsi_host *ihost = shost_priv(shost);
2802
2803         switch (param) {
2804         case ISCSI_HOST_PARAM_NETDEV_NAME:
2805                 if (!ihost->netdev)
2806                         ihost->netdev = kstrdup(buf, GFP_KERNEL);
2807                 break;
2808         case ISCSI_HOST_PARAM_HWADDRESS:
2809                 if (!ihost->hwaddress)
2810                         ihost->hwaddress = kstrdup(buf, GFP_KERNEL);
2811                 break;
2812         case ISCSI_HOST_PARAM_INITIATOR_NAME:
2813                 if (!ihost->initiatorname)
2814                         ihost->initiatorname = kstrdup(buf, GFP_KERNEL);
2815                 break;
2816         default:
2817                 return -ENOSYS;
2818         }
2819
2820         return 0;
2821 }
2822 EXPORT_SYMBOL_GPL(iscsi_host_set_param);
2823
2824 MODULE_AUTHOR("Mike Christie");
2825 MODULE_DESCRIPTION("iSCSI library functions");
2826 MODULE_LICENSE("GPL");