git.oblomov.eu Git - linux-2.6/blob - 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          * Check if cleanup_task dropped the lock and the command completed,
 409          */
 410         if (!task->sc)
 411                 return;
 412
 413         sc->result = err;
 414         if (!scsi_bidi_cmnd(sc))
 415                 scsi_set_resid(sc, scsi_bufflen(sc));
 416         else {
 417                 scsi_out(sc)->resid = scsi_out(sc)->length;
 418                 scsi_in(sc)->resid = scsi_in(sc)->length;
 419         }
 420
 421         if (conn->task == task)
 422                 conn->task = NULL;
 423         /* release ref from queuecommand */
 424         __iscsi_put_task(task);
 425 }
 426
 427 static int iscsi_prep_mgmt_task(struct iscsi_conn *conn,
 428                                 struct iscsi_task *task)
 429 {
 430         struct iscsi_session *session = conn->session;
 431         struct iscsi_hdr *hdr = (struct iscsi_hdr *)task->hdr;
 432         struct iscsi_nopout *nop = (struct iscsi_nopout *)hdr;
 433
 434         if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
 435                 return -ENOTCONN;
 436
 437         if (hdr->opcode != (ISCSI_OP_LOGIN | ISCSI_OP_IMMEDIATE) &&
 438             hdr->opcode != (ISCSI_OP_TEXT | ISCSI_OP_IMMEDIATE))
 439                 nop->exp_statsn = cpu_to_be32(conn->exp_statsn);
 440         /*
 441          * pre-format CmdSN for outgoing PDU.
 442          */
 443         nop->cmdsn = cpu_to_be32(session->cmdsn);
 444         if (hdr->itt != RESERVED_ITT) {
 445                 hdr->itt = build_itt(task->itt, session->age);
 446                 /*
 447                  * TODO: We always use immediate, so we never hit this.
 448                  * If we start to send tmfs or nops as non-immediate then
 449                  * we should start checking the cmdsn numbers for mgmt tasks.
 450                  */
 451                 if (conn->c_stage == ISCSI_CONN_STARTED &&
 452                     !(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
 453                         session->queued_cmdsn++;
 454                         session->cmdsn++;
 455                 }
 456         }
 457
 458         if (session->tt->init_task)
 459                 session->tt->init_task(task);
 460
 461         if ((hdr->opcode & ISCSI_OPCODE_MASK) == ISCSI_OP_LOGOUT)
 462                 session->state = ISCSI_STATE_LOGGING_OUT;
 463
 464         list_move_tail(&task->running, &conn->mgmt_run_list);
 465         debug_scsi("mgmtpdu [op 0x%x hdr->itt 0x%x datalen %d]\n",
 466                    hdr->opcode & ISCSI_OPCODE_MASK, hdr->itt,
 467                    task->data_count);
 468         return 0;
 469 }
 470
 471 static struct iscsi_task *
 472 __iscsi_conn_send_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 473                       char *data, uint32_t data_size)
 474 {
 475         struct iscsi_session *session = conn->session;
 476         struct iscsi_task *task;
 477
 478         if (session->state == ISCSI_STATE_TERMINATE)
 479                 return NULL;
 480
 481         if (hdr->opcode == (ISCSI_OP_LOGIN | ISCSI_OP_IMMEDIATE) ||
 482             hdr->opcode == (ISCSI_OP_TEXT | ISCSI_OP_IMMEDIATE))
 483                 /*
 484                  * Login and Text are sent serially, in
 485                  * request-followed-by-response sequence.
 486                  * Same task can be used. Same ITT must be used.
 487                  * Note that login_task is preallocated at conn_create().
 488                  */
 489                 task = conn->login_task;
 490         else {
 491                 BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
 492                 BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);
 493
 494                 if (!__kfifo_get(session->cmdpool.queue,
 495                                  (void*)&task, sizeof(void*)))
 496                         return NULL;
 497
 498                 if ((hdr->opcode == (ISCSI_OP_NOOP_OUT | ISCSI_OP_IMMEDIATE)) &&
 499                      hdr->ttt == RESERVED_ITT) {
 500                         conn->ping_task = task;
 501                         conn->last_ping = jiffies;
 502                 }
 503         }
 504         /*
 505          * released in complete pdu for task we expect a response for, and
 506          * released by the lld when it has transmitted the task for
 507          * pdus we do not expect a response for.
 508          */
 509         atomic_set(&task->refcount, 1);
 510         task->conn = conn;
 511         task->sc = NULL;
 512
 513         if (data_size) {
 514                 memcpy(task->data, data, data_size);
 515                 task->data_count = data_size;
 516         } else
 517                 task->data_count = 0;
 518
 519         memcpy(task->hdr, hdr, sizeof(struct iscsi_hdr));
 520         INIT_LIST_HEAD(&task->running);
 521         list_add_tail(&task->running, &conn->mgmtqueue);
 522
 523         if (session->tt->caps & CAP_DATA_PATH_OFFLOAD) {
 524                 if (iscsi_prep_mgmt_task(conn, task)) {
 525                         __iscsi_put_task(task);
 526                         return NULL;
 527                 }
 528
 529                 if (session->tt->xmit_task(task))
 530                         task = NULL;
 531
 532         } else
 533                 scsi_queue_work(conn->session->host, &conn->xmitwork);
 534
 535         return task;
 536 }
 537
 538 int iscsi_conn_send_pdu(struct iscsi_cls_conn *cls_conn, struct iscsi_hdr *hdr,
 539                         char *data, uint32_t data_size)
 540 {
 541         struct iscsi_conn *conn = cls_conn->dd_data;
 542         struct iscsi_session *session = conn->session;
 543         int err = 0;
 544
 545         spin_lock_bh(&session->lock);
 546         if (!__iscsi_conn_send_pdu(conn, hdr, data, data_size))
 547                 err = -EPERM;
 548         spin_unlock_bh(&session->lock);
 549         return err;
 550 }
 551 EXPORT_SYMBOL_GPL(iscsi_conn_send_pdu);
 552
 553 /**
 554  * iscsi_cmd_rsp - SCSI Command Response processing
 555  * @conn: iscsi connection
 556  * @hdr: iscsi header
 557  * @task: scsi command task
 558  * @data: cmd data buffer
 559  * @datalen: len of buffer
 560  *
 561  * iscsi_cmd_rsp sets up the scsi_cmnd fields based on the PDU and
 562  * then completes the command and task.
 563  **/
 564 static void iscsi_scsi_cmd_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 565                                struct iscsi_task *task, char *data,
 566                                int datalen)
 567 {
 568         struct iscsi_cmd_rsp *rhdr = (struct iscsi_cmd_rsp *)hdr;
 569         struct iscsi_session *session = conn->session;
 570         struct scsi_cmnd *sc = task->sc;
 571
 572         iscsi_update_cmdsn(session, (struct iscsi_nopin*)rhdr);
 573         conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 574
 575         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 576
 577         if (rhdr->response != ISCSI_STATUS_CMD_COMPLETED) {
 578                 sc->result = DID_ERROR << 16;
 579                 goto out;
 580         }
 581
 582         if (rhdr->cmd_status == SAM_STAT_CHECK_CONDITION) {
 583                 uint16_t senselen;
 584
 585                 if (datalen < 2) {
 586 invalid_datalen:
 587                         iscsi_conn_printk(KERN_ERR,  conn,
 588                                          "Got CHECK_CONDITION but invalid data "
 589                                          "buffer size of %d\n", datalen);
 590                         sc->result = DID_BAD_TARGET << 16;
 591                         goto out;
 592                 }
 593
 594                 senselen = get_unaligned_be16(data);
 595                 if (datalen < senselen)
 596                         goto invalid_datalen;
 597
 598                 memcpy(sc->sense_buffer, data + 2,
 599                        min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
 600                 debug_scsi("copied %d bytes of sense\n",
 601                            min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
 602         }
 603
 604         if (rhdr->flags & (ISCSI_FLAG_CMD_BIDI_UNDERFLOW |
 605                            ISCSI_FLAG_CMD_BIDI_OVERFLOW)) {
 606                 int res_count = be32_to_cpu(rhdr->bi_residual_count);
 607
 608                 if (scsi_bidi_cmnd(sc) && res_count > 0 &&
 609                                 (rhdr->flags & ISCSI_FLAG_CMD_BIDI_OVERFLOW ||
 610                                  res_count <= scsi_in(sc)->length))
 611                         scsi_in(sc)->resid = res_count;
 612                 else
 613                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 614         }
 615
 616         if (rhdr->flags & (ISCSI_FLAG_CMD_UNDERFLOW |
 617                            ISCSI_FLAG_CMD_OVERFLOW)) {
 618                 int res_count = be32_to_cpu(rhdr->residual_count);
 619
 620                 if (res_count > 0 &&
 621                     (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
 622                      res_count <= scsi_bufflen(sc)))
 623                         /* write side for bidi or uni-io set_resid */
 624                         scsi_set_resid(sc, res_count);
 625                 else
 626                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 627         }
 628 out:
 629         debug_scsi("done [sc %lx res %d itt 0x%x]\n",
 630                    (long)sc, sc->result, task->itt);
 631         conn->scsirsp_pdus_cnt++;
 632
 633         __iscsi_put_task(task);
 634 }
 635
 636 static void iscsi_tmf_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
 637 {
 638         struct iscsi_tm_rsp *tmf = (struct iscsi_tm_rsp *)hdr;
 639
 640         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 641         conn->tmfrsp_pdus_cnt++;
 642
 643         if (conn->tmf_state != TMF_QUEUED)
 644                 return;
 645
 646         if (tmf->response == ISCSI_TMF_RSP_COMPLETE)
 647                 conn->tmf_state = TMF_SUCCESS;
 648         else if (tmf->response == ISCSI_TMF_RSP_NO_TASK)
 649                 conn->tmf_state = TMF_NOT_FOUND;
 650         else
 651                 conn->tmf_state = TMF_FAILED;
 652         wake_up(&conn->ehwait);
 653 }
 654
 655 static void iscsi_send_nopout(struct iscsi_conn *conn, struct iscsi_nopin *rhdr)
 656 {
 657         struct iscsi_nopout hdr;
 658         struct iscsi_task *task;
 659
 660         if (!rhdr && conn->ping_task)
 661                 return;
 662
 663         memset(&hdr, 0, sizeof(struct iscsi_nopout));
 664         hdr.opcode = ISCSI_OP_NOOP_OUT | ISCSI_OP_IMMEDIATE;
 665         hdr.flags = ISCSI_FLAG_CMD_FINAL;
 666
 667         if (rhdr) {
 668                 memcpy(hdr.lun, rhdr->lun, 8);
 669                 hdr.ttt = rhdr->ttt;
 670                 hdr.itt = RESERVED_ITT;
 671         } else
 672                 hdr.ttt = RESERVED_ITT;
 673
 674         task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)&hdr, NULL, 0);
 675         if (!task)
 676                 iscsi_conn_printk(KERN_ERR, conn, "Could not send nopout\n");
 677 }
 678
 679 static int iscsi_handle_reject(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 680                                char *data, int datalen)
 681 {
 682         struct iscsi_reject *reject = (struct iscsi_reject *)hdr;
 683         struct iscsi_hdr rejected_pdu;
 684         uint32_t itt;
 685
 686         conn->exp_statsn = be32_to_cpu(reject->statsn) + 1;
 687
 688         if (reject->reason == ISCSI_REASON_DATA_DIGEST_ERROR) {
 689                 if (ntoh24(reject->dlength) > datalen)
 690                         return ISCSI_ERR_PROTO;
 691
 692                 if (ntoh24(reject->dlength) >= sizeof(struct iscsi_hdr)) {
 693                         memcpy(&rejected_pdu, data, sizeof(struct iscsi_hdr));
 694                         itt = get_itt(rejected_pdu.itt);
 695                         iscsi_conn_printk(KERN_ERR, conn,
 696                                           "itt 0x%x had pdu (op 0x%x) rejected "
 697                                           "due to DataDigest error.\n", itt,
 698                                           rejected_pdu.opcode);
 699                 }
 700         }
 701         return 0;
 702 }
 703
 704 /**
 705  * iscsi_itt_to_task - look up task by itt
 706  * @conn: iscsi connection
 707  * @itt: itt
 708  *
 709  * This should be used for mgmt tasks like login and nops, or if
 710  * the LDD's itt space does not include the session age.
 711  *
 712  * The session lock must be held.
 713  */
 714 static struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *conn, itt_t itt)
 715 {
 716         struct iscsi_session *session = conn->session;
 717         uint32_t i;
 718
 719         if (itt == RESERVED_ITT)
 720                 return NULL;
 721
 722         i = get_itt(itt);
 723         if (i >= session->cmds_max)
 724                 return NULL;
 725
 726         return session->cmds[i];
 727 }
 728
 729 /**
 730  * __iscsi_complete_pdu - complete pdu
 731  * @conn: iscsi conn
 732  * @hdr: iscsi header
 733  * @data: data buffer
 734  * @datalen: len of data buffer
 735  *
 736  * Completes pdu processing by freeing any resources allocated at
 737  * queuecommand or send generic. session lock must be held and verify
 738  * itt must have been called.
 739  */
 740 int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 741                          char *data, int datalen)
 742 {
 743         struct iscsi_session *session = conn->session;
 744         int opcode = hdr->opcode & ISCSI_OPCODE_MASK, rc = 0;
 745         struct iscsi_task *task;
 746         uint32_t itt;
 747
 748         conn->last_recv = jiffies;
 749         rc = iscsi_verify_itt(conn, hdr->itt);
 750         if (rc)
 751                 return rc;
 752
 753         if (hdr->itt != RESERVED_ITT)
 754                 itt = get_itt(hdr->itt);
 755         else
 756                 itt = ~0U;
 757
 758         debug_scsi("[op 0x%x cid %d itt 0x%x len %d]\n",
 759                    opcode, conn->id, itt, datalen);
 760
 761         if (itt == ~0U) {
 762                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
 763
 764                 switch(opcode) {
 765                 case ISCSI_OP_NOOP_IN:
 766                         if (datalen) {
 767                                 rc = ISCSI_ERR_PROTO;
 768                                 break;
 769                         }
 770
 771                         if (hdr->ttt == cpu_to_be32(ISCSI_RESERVED_TAG))
 772                                 break;
 773
 774                         iscsi_send_nopout(conn, (struct iscsi_nopin*)hdr);
 775                         break;
 776                 case ISCSI_OP_REJECT:
 777                         rc = iscsi_handle_reject(conn, hdr, data, datalen);
 778                         break;
 779                 case ISCSI_OP_ASYNC_EVENT:
 780                         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 781                         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
 782                                 rc = ISCSI_ERR_CONN_FAILED;
 783                         break;
 784                 default:
 785                         rc = ISCSI_ERR_BAD_OPCODE;
 786                         break;
 787                 }
 788                 goto out;
 789         }
 790
 791         switch(opcode) {
 792         case ISCSI_OP_SCSI_CMD_RSP:
 793         case ISCSI_OP_SCSI_DATA_IN:
 794                 task = iscsi_itt_to_ctask(conn, hdr->itt);
 795                 if (!task)
 796                         return ISCSI_ERR_BAD_ITT;
 797                 break;
 798         case ISCSI_OP_R2T:
 799                 /*
 800                  * LLD handles R2Ts if they need to.
 801                  */
 802                 return 0;
 803         case ISCSI_OP_LOGOUT_RSP:
 804         case ISCSI_OP_LOGIN_RSP:
 805         case ISCSI_OP_TEXT_RSP:
 806         case ISCSI_OP_SCSI_TMFUNC_RSP:
 807         case ISCSI_OP_NOOP_IN:
 808                 task = iscsi_itt_to_task(conn, hdr->itt);
 809                 if (!task)
 810                         return ISCSI_ERR_BAD_ITT;
 811                 break;
 812         default:
 813                 return ISCSI_ERR_BAD_OPCODE;
 814         }
 815
 816         switch(opcode) {
 817         case ISCSI_OP_SCSI_CMD_RSP:
 818                 iscsi_scsi_cmd_rsp(conn, hdr, task, data, datalen);
 819                 break;
 820         case ISCSI_OP_SCSI_DATA_IN:
 821                 if (hdr->flags & ISCSI_FLAG_DATA_STATUS) {
 822                         conn->scsirsp_pdus_cnt++;
 823                         iscsi_update_cmdsn(session,
 824                                            (struct iscsi_nopin*) hdr);
 825                         __iscsi_put_task(task);
 826                 }
 827                 break;
 828         case ISCSI_OP_LOGOUT_RSP:
 829                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
 830                 if (datalen) {
 831                         rc = ISCSI_ERR_PROTO;
 832                         break;
 833                 }
 834                 conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 835                 goto recv_pdu;
 836         case ISCSI_OP_LOGIN_RSP:
 837         case ISCSI_OP_TEXT_RSP:
 838                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
 839                 /*
 840                  * login related PDU's exp_statsn is handled in
 841                  * userspace
 842                  */
 843                 goto recv_pdu;
 844         case ISCSI_OP_SCSI_TMFUNC_RSP:
 845                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
 846                 if (datalen) {
 847                         rc = ISCSI_ERR_PROTO;
 848                         break;
 849                 }
 850
 851                 iscsi_tmf_rsp(conn, hdr);
 852                 __iscsi_put_task(task);
 853                 break;
 854         case ISCSI_OP_NOOP_IN:
 855                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
 856                 if (hdr->ttt != cpu_to_be32(ISCSI_RESERVED_TAG) || datalen) {
 857                         rc = ISCSI_ERR_PROTO;
 858                         break;
 859                 }
 860                 conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 861
 862                 if (conn->ping_task != task)
 863                         /*
 864                          * If this is not in response to one of our
 865                          * nops then it must be from userspace.
 866                          */
 867                         goto recv_pdu;
 868
 869                 mod_timer(&conn->transport_timer, jiffies + conn->recv_timeout);
 870                 __iscsi_put_task(task);
 871                 break;
 872         default:
 873                 rc = ISCSI_ERR_BAD_OPCODE;
 874                 break;
 875         }
 876
 877 out:
 878         return rc;
 879 recv_pdu:
 880         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
 881                 rc = ISCSI_ERR_CONN_FAILED;
 882         __iscsi_put_task(task);
 883         return rc;
 884 }
 885 EXPORT_SYMBOL_GPL(__iscsi_complete_pdu);
 886
 887 int iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 888                        char *data, int datalen)
 889 {
 890         int rc;
 891
 892         spin_lock(&conn->session->lock);
 893         rc = __iscsi_complete_pdu(conn, hdr, data, datalen);
 894         spin_unlock(&conn->session->lock);
 895         return rc;
 896 }
 897 EXPORT_SYMBOL_GPL(iscsi_complete_pdu);
 898
 899 int iscsi_verify_itt(struct iscsi_conn *conn, itt_t itt)
 900 {
 901         struct iscsi_session *session = conn->session;
 902         uint32_t i;
 903
 904         if (itt == RESERVED_ITT)
 905                 return 0;
 906
 907         if (((__force u32)itt & ISCSI_AGE_MASK) !=
 908             (session->age << ISCSI_AGE_SHIFT)) {
 909                 iscsi_conn_printk(KERN_ERR, conn,
 910                                   "received itt %x expected session age (%x)\n",
 911                                   (__force u32)itt, session->age);
 912                 return ISCSI_ERR_BAD_ITT;
 913         }
 914
 915         i = get_itt(itt);
 916         if (i >= session->cmds_max) {
 917                 iscsi_conn_printk(KERN_ERR, conn,
 918                                   "received invalid itt index %u (max cmds "
 919                                    "%u.\n", i, session->cmds_max);
 920                 return ISCSI_ERR_BAD_ITT;
 921         }
 922         return 0;
 923 }
 924 EXPORT_SYMBOL_GPL(iscsi_verify_itt);
 925
 926 /**
 927  * iscsi_itt_to_ctask - look up ctask by itt
 928  * @conn: iscsi connection
 929  * @itt: itt
 930  *
 931  * This should be used for cmd tasks.
 932  *
 933  * The session lock must be held.
 934  */
 935 struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *conn, itt_t itt)
 936 {
 937         struct iscsi_task *task;
 938
 939         if (iscsi_verify_itt(conn, itt))
 940                 return NULL;
 941
 942         task = iscsi_itt_to_task(conn, itt);
 943         if (!task || !task->sc)
 944                 return NULL;
 945
 946         if (task->sc->SCp.phase != conn->session->age) {
 947                 iscsi_session_printk(KERN_ERR, conn->session,
 948                                   "task's session age %d, expected %d\n",
 949                                   task->sc->SCp.phase, conn->session->age);
 950                 return NULL;
 951         }
 952
 953         return task;
 954 }
 955 EXPORT_SYMBOL_GPL(iscsi_itt_to_ctask);
 956
 957 void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err)
 958 {
 959         struct iscsi_session *session = conn->session;
 960         unsigned long flags;
 961
 962         spin_lock_irqsave(&session->lock, flags);
 963         if (session->state == ISCSI_STATE_FAILED) {
 964                 spin_unlock_irqrestore(&session->lock, flags);
 965                 return;
 966         }
 967
 968         if (conn->stop_stage == 0)
 969                 session->state = ISCSI_STATE_FAILED;
 970         spin_unlock_irqrestore(&session->lock, flags);
 971         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
 972         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
 973         iscsi_conn_error(conn->cls_conn, err);
 974 }
 975 EXPORT_SYMBOL_GPL(iscsi_conn_failure);
 976
 977 static int iscsi_check_cmdsn_window_closed(struct iscsi_conn *conn)
 978 {
 979         struct iscsi_session *session = conn->session;
 980
 981         /*
 982          * Check for iSCSI window and take care of CmdSN wrap-around
 983          */
 984         if (!iscsi_sna_lte(session->queued_cmdsn, session->max_cmdsn)) {
 985                 debug_scsi("iSCSI CmdSN closed. ExpCmdSn %u MaxCmdSN %u "
 986                            "CmdSN %u/%u\n", session->exp_cmdsn,
 987                            session->max_cmdsn, session->cmdsn,
 988                            session->queued_cmdsn);
 989                 return -ENOSPC;
 990         }
 991         return 0;
 992 }
 993
 994 static int iscsi_xmit_task(struct iscsi_conn *conn)
 995 {
 996         struct iscsi_task *task = conn->task;
 997         int rc;
 998
 999         __iscsi_get_task(task);
1000         spin_unlock_bh(&conn->session->lock);
1001         rc = conn->session->tt->xmit_task(task);
1002         spin_lock_bh(&conn->session->lock);
1003         __iscsi_put_task(task);
1004         if (!rc)
1005                 /* done with this task */
1006                 conn->task = NULL;
1007         return rc;
1008 }
1009
1010 /**
1011  * iscsi_requeue_task - requeue task to run from session workqueue
1012  * @task: task to requeue
1013  *
1014  * LLDs that need to run a task from the session workqueue should call
1015  * this. The session lock must be held. This should only be called
1016  * by software drivers.
1017  */
1018 void iscsi_requeue_task(struct iscsi_task *task)
1019 {
1020         struct iscsi_conn *conn = task->conn;
1021
1022         list_move_tail(&task->running, &conn->requeue);
1023         scsi_queue_work(conn->session->host, &conn->xmitwork);
1024 }
1025 EXPORT_SYMBOL_GPL(iscsi_requeue_task);
1026
1027 /**
1028  * iscsi_data_xmit - xmit any command into the scheduled connection
1029  * @conn: iscsi connection
1030  *
1031  * Notes:
1032  *      The function can return -EAGAIN in which case the caller must
1033  *      re-schedule it again later or recover. '0' return code means
1034  *      successful xmit.
1035  **/
1036 static int iscsi_data_xmit(struct iscsi_conn *conn)
1037 {
1038         int rc = 0;
1039
1040         spin_lock_bh(&conn->session->lock);
1041         if (unlikely(conn->suspend_tx)) {
1042                 debug_scsi("conn %d Tx suspended!\n", conn->id);
1043                 spin_unlock_bh(&conn->session->lock);
1044                 return -ENODATA;
1045         }
1046
1047         if (conn->task) {
1048                 rc = iscsi_xmit_task(conn);
1049                 if (rc)
1050                         goto again;
1051         }
1052
1053         /*
1054          * process mgmt pdus like nops before commands since we should
1055          * only have one nop-out as a ping from us and targets should not
1056          * overflow us with nop-ins
1057          */
1058 check_mgmt:
1059         while (!list_empty(&conn->mgmtqueue)) {
1060                 conn->task = list_entry(conn->mgmtqueue.next,
1061                                          struct iscsi_task, running);
1062                 if (iscsi_prep_mgmt_task(conn, conn->task)) {
1063                         __iscsi_put_task(conn->task);
1064                         conn->task = NULL;
1065                         continue;
1066                 }
1067                 rc = iscsi_xmit_task(conn);
1068                 if (rc)
1069                         goto again;
1070         }
1071
1072         /* process pending command queue */
1073         while (!list_empty(&conn->xmitqueue)) {
1074                 if (conn->tmf_state == TMF_QUEUED)
1075                         break;
1076
1077                 conn->task = list_entry(conn->xmitqueue.next,
1078                                          struct iscsi_task, running);
1079                 if (conn->session->state == ISCSI_STATE_LOGGING_OUT) {
1080                         fail_command(conn, conn->task, DID_IMM_RETRY << 16);
1081                         continue;
1082                 }
1083                 if (iscsi_prep_scsi_cmd_pdu(conn->task)) {
1084                         fail_command(conn, conn->task, DID_ABORT << 16);
1085                         continue;
1086                 }
1087                 rc = iscsi_xmit_task(conn);
1088                 if (rc)
1089                         goto again;
1090                 /*
1091                  * we could continuously get new task requests so
1092                  * we need to check the mgmt queue for nops that need to
1093                  * be sent to aviod starvation
1094                  */
1095                 if (!list_empty(&conn->mgmtqueue))
1096                         goto check_mgmt;
1097         }
1098
1099         while (!list_empty(&conn->requeue)) {
1100                 if (conn->session->fast_abort && conn->tmf_state != TMF_INITIAL)
1101                         break;
1102
1103                 /*
1104                  * we always do fastlogout - conn stop code will clean up.
1105                  */
1106                 if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
1107                         break;
1108
1109                 conn->task = list_entry(conn->requeue.next,
1110                                          struct iscsi_task, running);
1111                 conn->task->state = ISCSI_TASK_RUNNING;
1112                 list_move_tail(conn->requeue.next, &conn->run_list);
1113                 rc = iscsi_xmit_task(conn);
1114                 if (rc)
1115                         goto again;
1116                 if (!list_empty(&conn->mgmtqueue))
1117                         goto check_mgmt;
1118         }
1119         spin_unlock_bh(&conn->session->lock);
1120         return -ENODATA;
1121
1122 again:
1123         if (unlikely(conn->suspend_tx))
1124                 rc = -ENODATA;
1125         spin_unlock_bh(&conn->session->lock);
1126         return rc;
1127 }
1128
1129 static void iscsi_xmitworker(struct work_struct *work)
1130 {
1131         struct iscsi_conn *conn =
1132                 container_of(work, struct iscsi_conn, xmitwork);
1133         int rc;
1134         /*
1135          * serialize Xmit worker on a per-connection basis.
1136          */
1137         do {
1138                 rc = iscsi_data_xmit(conn);
1139         } while (rc >= 0 || rc == -EAGAIN);
1140 }
1141
1142 enum {
1143         FAILURE_BAD_HOST = 1,
1144         FAILURE_SESSION_FAILED,
1145         FAILURE_SESSION_FREED,
1146         FAILURE_WINDOW_CLOSED,
1147         FAILURE_OOM,
1148         FAILURE_SESSION_TERMINATE,
1149         FAILURE_SESSION_IN_RECOVERY,
1150         FAILURE_SESSION_RECOVERY_TIMEOUT,
1151         FAILURE_SESSION_LOGGING_OUT,
1152         FAILURE_SESSION_NOT_READY,
1153 };
1154
1155 int iscsi_queuecommand(struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *))
1156 {
1157         struct iscsi_cls_session *cls_session;
1158         struct Scsi_Host *host;
1159         int reason = 0;
1160         struct iscsi_session *session;
1161         struct iscsi_conn *conn;
1162         struct iscsi_task *task = NULL;
1163
1164         sc->scsi_done = done;
1165         sc->result = 0;
1166         sc->SCp.ptr = NULL;
1167
1168         host = sc->device->host;
1169         spin_unlock(host->host_lock);
1170
1171         cls_session = starget_to_session(scsi_target(sc->device));
1172         session = cls_session->dd_data;
1173         spin_lock(&session->lock);
1174
1175         reason = iscsi_session_chkready(cls_session);
1176         if (reason) {
1177                 sc->result = reason;
1178                 goto fault;
1179         }
1180
1181         /*
1182          * ISCSI_STATE_FAILED is a temp. state. The recovery
1183          * code will decide what is best to do with command queued
1184          * during this time
1185          */
1186         if (session->state != ISCSI_STATE_LOGGED_IN &&
1187             session->state != ISCSI_STATE_FAILED) {
1188                 /*
1189                  * to handle the race between when we set the recovery state
1190                  * and block the session we requeue here (commands could
1191                  * be entering our queuecommand while a block is starting
1192                  * up because the block code is not locked)
1193                  */
1194                 switch (session->state) {
1195                 case ISCSI_STATE_IN_RECOVERY:
1196                         reason = FAILURE_SESSION_IN_RECOVERY;
1197                         sc->result = DID_IMM_RETRY << 16;
1198                         break;
1199                 case ISCSI_STATE_LOGGING_OUT:
1200                         reason = FAILURE_SESSION_LOGGING_OUT;
1201                         sc->result = DID_IMM_RETRY << 16;
1202                         break;
1203                 case ISCSI_STATE_RECOVERY_FAILED:
1204                         reason = FAILURE_SESSION_RECOVERY_TIMEOUT;
1205                         sc->result = DID_NO_CONNECT << 16;
1206                         break;
1207                 case ISCSI_STATE_TERMINATE:
1208                         reason = FAILURE_SESSION_TERMINATE;
1209                         sc->result = DID_NO_CONNECT << 16;
1210                         break;
1211                 default:
1212                         reason = FAILURE_SESSION_FREED;
1213                         sc->result = DID_NO_CONNECT << 16;
1214                 }
1215                 goto fault;
1216         }
1217
1218         conn = session->leadconn;
1219         if (!conn) {
1220                 reason = FAILURE_SESSION_FREED;
1221                 sc->result = DID_NO_CONNECT << 16;
1222                 goto fault;
1223         }
1224
1225         if (iscsi_check_cmdsn_window_closed(conn)) {
1226                 reason = FAILURE_WINDOW_CLOSED;
1227                 goto reject;
1228         }
1229
1230         if (!__kfifo_get(session->cmdpool.queue, (void*)&task,
1231                          sizeof(void*))) {
1232                 reason = FAILURE_OOM;
1233                 goto reject;
1234         }
1235         sc->SCp.phase = session->age;
1236         sc->SCp.ptr = (char *)task;
1237
1238         atomic_set(&task->refcount, 1);
1239         task->state = ISCSI_TASK_PENDING;
1240         task->conn = conn;
1241         task->sc = sc;
1242         INIT_LIST_HEAD(&task->running);
1243         list_add_tail(&task->running, &conn->xmitqueue);
1244
1245         if (session->tt->caps & CAP_DATA_PATH_OFFLOAD) {
1246                 if (iscsi_prep_scsi_cmd_pdu(task)) {
1247                         sc->result = DID_ABORT << 16;
1248                         sc->scsi_done = NULL;
1249                         iscsi_complete_command(task);
1250                         goto fault;
1251                 }
1252                 if (session->tt->xmit_task(task)) {
1253                         sc->scsi_done = NULL;
1254                         iscsi_complete_command(task);
1255                         reason = FAILURE_SESSION_NOT_READY;
1256                         goto reject;
1257                 }
1258         } else
1259                 scsi_queue_work(session->host, &conn->xmitwork);
1260
1261         session->queued_cmdsn++;
1262         spin_unlock(&session->lock);
1263         spin_lock(host->host_lock);
1264         return 0;
1265
1266 reject:
1267         spin_unlock(&session->lock);
1268         debug_scsi("cmd 0x%x rejected (%d)\n", sc->cmnd[0], reason);
1269         spin_lock(host->host_lock);
1270         return SCSI_MLQUEUE_HOST_BUSY;
1271
1272 fault:
1273         spin_unlock(&session->lock);
1274         debug_scsi("iscsi: cmd 0x%x is not queued (%d)\n", sc->cmnd[0], reason);
1275         if (!scsi_bidi_cmnd(sc))
1276                 scsi_set_resid(sc, scsi_bufflen(sc));
1277         else {
1278                 scsi_out(sc)->resid = scsi_out(sc)->length;
1279                 scsi_in(sc)->resid = scsi_in(sc)->length;
1280         }
1281         done(sc);
1282         spin_lock(host->host_lock);
1283         return 0;
1284 }
1285 EXPORT_SYMBOL_GPL(iscsi_queuecommand);
1286
1287 int iscsi_change_queue_depth(struct scsi_device *sdev, int depth)
1288 {
1289         if (depth > ISCSI_MAX_CMD_PER_LUN)
1290                 depth = ISCSI_MAX_CMD_PER_LUN;
1291         scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
1292         return sdev->queue_depth;
1293 }
1294 EXPORT_SYMBOL_GPL(iscsi_change_queue_depth);
1295
1296 void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
1297 {
1298         struct iscsi_session *session = cls_session->dd_data;
1299
1300         spin_lock_bh(&session->lock);
1301         if (session->state != ISCSI_STATE_LOGGED_IN) {
1302                 session->state = ISCSI_STATE_RECOVERY_FAILED;
1303                 if (session->leadconn)
1304                         wake_up(&session->leadconn->ehwait);
1305         }
1306         spin_unlock_bh(&session->lock);
1307 }
1308 EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
1309
1310 int iscsi_eh_host_reset(struct scsi_cmnd *sc)
1311 {
1312         struct iscsi_cls_session *cls_session;
1313         struct iscsi_session *session;
1314         struct iscsi_conn *conn;
1315
1316         cls_session = starget_to_session(scsi_target(sc->device));
1317         session = cls_session->dd_data;
1318         conn = session->leadconn;
1319
1320         mutex_lock(&session->eh_mutex);
1321         spin_lock_bh(&session->lock);
1322         if (session->state == ISCSI_STATE_TERMINATE) {
1323 failed:
1324                 debug_scsi("failing host reset: session terminated "
1325                            "[CID %d age %d]\n", conn->id, session->age);
1326                 spin_unlock_bh(&session->lock);
1327                 mutex_unlock(&session->eh_mutex);
1328                 return FAILED;
1329         }
1330
1331         spin_unlock_bh(&session->lock);
1332         mutex_unlock(&session->eh_mutex);
1333         /*
1334          * we drop the lock here but the leadconn cannot be destoyed while
1335          * we are in the scsi eh
1336          */
1337         iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1338
1339         debug_scsi("iscsi_eh_host_reset wait for relogin\n");
1340         wait_event_interruptible(conn->ehwait,
1341                                  session->state == ISCSI_STATE_TERMINATE ||
1342                                  session->state == ISCSI_STATE_LOGGED_IN ||
1343                                  session->state == ISCSI_STATE_RECOVERY_FAILED);
1344         if (signal_pending(current))
1345                 flush_signals(current);
1346
1347         mutex_lock(&session->eh_mutex);
1348         spin_lock_bh(&session->lock);
1349         if (session->state == ISCSI_STATE_LOGGED_IN)
1350                 iscsi_session_printk(KERN_INFO, session,
1351                                      "host reset succeeded\n");
1352         else
1353                 goto failed;
1354         spin_unlock_bh(&session->lock);
1355         mutex_unlock(&session->eh_mutex);
1356         return SUCCESS;
1357 }
1358 EXPORT_SYMBOL_GPL(iscsi_eh_host_reset);
1359
1360 static void iscsi_tmf_timedout(unsigned long data)
1361 {
1362         struct iscsi_conn *conn = (struct iscsi_conn *)data;
1363         struct iscsi_session *session = conn->session;
1364
1365         spin_lock(&session->lock);
1366         if (conn->tmf_state == TMF_QUEUED) {
1367                 conn->tmf_state = TMF_TIMEDOUT;
1368                 debug_scsi("tmf timedout\n");
1369                 /* unblock eh_abort() */
1370                 wake_up(&conn->ehwait);
1371         }
1372         spin_unlock(&session->lock);
1373 }
1374
1375 static int iscsi_exec_task_mgmt_fn(struct iscsi_conn *conn,
1376                                    struct iscsi_tm *hdr, int age,
1377                                    int timeout)
1378 {
1379         struct iscsi_session *session = conn->session;
1380         struct iscsi_task *task;
1381
1382         task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)hdr,
1383                                       NULL, 0);
1384         if (!task) {
1385                 spin_unlock_bh(&session->lock);
1386                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1387                 spin_lock_bh(&session->lock);
1388                 debug_scsi("tmf exec failure\n");
1389                 return -EPERM;
1390         }
1391         conn->tmfcmd_pdus_cnt++;
1392         conn->tmf_timer.expires = timeout * HZ + jiffies;
1393         conn->tmf_timer.function = iscsi_tmf_timedout;
1394         conn->tmf_timer.data = (unsigned long)conn;
1395         add_timer(&conn->tmf_timer);
1396         debug_scsi("tmf set timeout\n");
1397
1398         spin_unlock_bh(&session->lock);
1399         mutex_unlock(&session->eh_mutex);
1400
1401         /*
1402          * block eh thread until:
1403          *
1404          * 1) tmf response
1405          * 2) tmf timeout
1406          * 3) session is terminated or restarted or userspace has
1407          * given up on recovery
1408          */
1409         wait_event_interruptible(conn->ehwait, age != session->age ||
1410                                  session->state != ISCSI_STATE_LOGGED_IN ||
1411                                  conn->tmf_state != TMF_QUEUED);
1412         if (signal_pending(current))
1413                 flush_signals(current);
1414         del_timer_sync(&conn->tmf_timer);
1415
1416         mutex_lock(&session->eh_mutex);
1417         spin_lock_bh(&session->lock);
1418         /* if the session drops it will clean up the task */
1419         if (age != session->age ||
1420             session->state != ISCSI_STATE_LOGGED_IN)
1421                 return -ENOTCONN;
1422         return 0;
1423 }
1424
1425 /*
1426  * Fail commands. session lock held and recv side suspended and xmit
1427  * thread flushed
1428  */
1429 static void fail_all_commands(struct iscsi_conn *conn, unsigned lun,
1430                               int error)
1431 {
1432         struct iscsi_task *task, *tmp;
1433
1434         if (conn->task && (conn->task->sc->device->lun == lun || lun == -1))
1435                 conn->task = NULL;
1436
1437         /* flush pending */
1438         list_for_each_entry_safe(task, tmp, &conn->xmitqueue, running) {
1439                 if (lun == task->sc->device->lun || lun == -1) {
1440                         debug_scsi("failing pending sc %p itt 0x%x\n",
1441                                    task->sc, task->itt);
1442                         fail_command(conn, task, error << 16);
1443                 }
1444         }
1445
1446         list_for_each_entry_safe(task, tmp, &conn->requeue, running) {
1447                 if (lun == task->sc->device->lun || lun == -1) {
1448                         debug_scsi("failing requeued sc %p itt 0x%x\n",
1449                                    task->sc, task->itt);
1450                         fail_command(conn, task, error << 16);
1451                 }
1452         }
1453
1454         /* fail all other running */
1455         list_for_each_entry_safe(task, tmp, &conn->run_list, running) {
1456                 if (lun == task->sc->device->lun || lun == -1) {
1457                         debug_scsi("failing in progress sc %p itt 0x%x\n",
1458                                    task->sc, task->itt);
1459                         fail_command(conn, task, error << 16);
1460                 }
1461         }
1462 }
1463
1464 void iscsi_suspend_tx(struct iscsi_conn *conn)
1465 {
1466         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1467         if (!(conn->session->tt->caps & CAP_DATA_PATH_OFFLOAD))
1468                 scsi_flush_work(conn->session->host);
1469 }
1470 EXPORT_SYMBOL_GPL(iscsi_suspend_tx);
1471
1472 static void iscsi_start_tx(struct iscsi_conn *conn)
1473 {
1474         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1475         if (!(conn->session->tt->caps & CAP_DATA_PATH_OFFLOAD))
1476                 scsi_queue_work(conn->session->host, &conn->xmitwork);
1477 }
1478
1479 static enum blk_eh_timer_return iscsi_eh_cmd_timed_out(struct scsi_cmnd *scmd)
1480 {
1481         struct iscsi_cls_session *cls_session;
1482         struct iscsi_session *session;
1483         struct iscsi_conn *conn;
1484         enum blk_eh_timer_return rc = BLK_EH_NOT_HANDLED;
1485
1486         cls_session = starget_to_session(scsi_target(scmd->device));
1487         session = cls_session->dd_data;
1488
1489         debug_scsi("scsi cmd %p timedout\n", scmd);
1490
1491         spin_lock(&session->lock);
1492         if (session->state != ISCSI_STATE_LOGGED_IN) {
1493                 /*
1494                  * We are probably in the middle of iscsi recovery so let
1495                  * that complete and handle the error.
1496                  */
1497                 rc = BLK_EH_RESET_TIMER;
1498                 goto done;
1499         }
1500
1501         conn = session->leadconn;
1502         if (!conn) {
1503                 /* In the middle of shuting down */
1504                 rc = BLK_EH_RESET_TIMER;
1505                 goto done;
1506         }
1507
1508         if (!conn->recv_timeout && !conn->ping_timeout)
1509                 goto done;
1510         /*
1511          * if the ping timedout then we are in the middle of cleaning up
1512          * and can let the iscsi eh handle it
1513          */
1514         if (time_before_eq(conn->last_recv + (conn->recv_timeout * HZ) +
1515                             (conn->ping_timeout * HZ), jiffies))
1516                 rc = BLK_EH_RESET_TIMER;
1517         /*
1518          * if we are about to check the transport then give the command
1519          * more time
1520          */
1521         if (time_before_eq(conn->last_recv + (conn->recv_timeout * HZ),
1522                            jiffies))
1523                 rc = BLK_EH_RESET_TIMER;
1524         /* if in the middle of checking the transport then give us more time */
1525         if (conn->ping_task)
1526                 rc = BLK_EH_RESET_TIMER;
1527 done:
1528         spin_unlock(&session->lock);
1529         debug_scsi("return %s\n", rc == BLK_EH_RESET_TIMER ?
1530                                         "timer reset" : "nh");
1531         return rc;
1532 }
1533
1534 static void iscsi_check_transport_timeouts(unsigned long data)
1535 {
1536         struct iscsi_conn *conn = (struct iscsi_conn *)data;
1537         struct iscsi_session *session = conn->session;
1538         unsigned long recv_timeout, next_timeout = 0, last_recv;
1539
1540         spin_lock(&session->lock);
1541         if (session->state != ISCSI_STATE_LOGGED_IN)
1542                 goto done;
1543
1544         recv_timeout = conn->recv_timeout;
1545         if (!recv_timeout)
1546                 goto done;
1547
1548         recv_timeout *= HZ;
1549         last_recv = conn->last_recv;
1550         if (conn->ping_task &&
1551             time_before_eq(conn->last_ping + (conn->ping_timeout * HZ),
1552                            jiffies)) {
1553                 iscsi_conn_printk(KERN_ERR, conn, "ping timeout of %d secs "
1554                                   "expired, last rx %lu, last ping %lu, "
1555                                   "now %lu\n", conn->ping_timeout, last_recv,
1556                                   conn->last_ping, jiffies);
1557                 spin_unlock(&session->lock);
1558                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1559                 return;
1560         }
1561
1562         if (time_before_eq(last_recv + recv_timeout, jiffies)) {
1563                 /* send a ping to try to provoke some traffic */
1564                 debug_scsi("Sending nopout as ping on conn %p\n", conn);
1565                 iscsi_send_nopout(conn, NULL);
1566                 next_timeout = conn->last_ping + (conn->ping_timeout * HZ);
1567         } else
1568                 next_timeout = last_recv + recv_timeout;
1569
1570         debug_scsi("Setting next tmo %lu\n", next_timeout);
1571         mod_timer(&conn->transport_timer, next_timeout);
1572 done:
1573         spin_unlock(&session->lock);
1574 }
1575
1576 static void iscsi_prep_abort_task_pdu(struct iscsi_task *task,
1577                                       struct iscsi_tm *hdr)
1578 {
1579         memset(hdr, 0, sizeof(*hdr));
1580         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
1581         hdr->flags = ISCSI_TM_FUNC_ABORT_TASK & ISCSI_FLAG_TM_FUNC_MASK;
1582         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
1583         memcpy(hdr->lun, task->hdr->lun, sizeof(hdr->lun));
1584         hdr->rtt = task->hdr->itt;
1585         hdr->refcmdsn = task->hdr->cmdsn;
1586 }
1587
1588 int iscsi_eh_abort(struct scsi_cmnd *sc)
1589 {
1590         struct iscsi_cls_session *cls_session;
1591         struct iscsi_session *session;
1592         struct iscsi_conn *conn;
1593         struct iscsi_task *task;
1594         struct iscsi_tm *hdr;
1595         int rc, age;
1596
1597         cls_session = starget_to_session(scsi_target(sc->device));
1598         session = cls_session->dd_data;
1599
1600         mutex_lock(&session->eh_mutex);
1601         spin_lock_bh(&session->lock);
1602         /*
1603          * if session was ISCSI_STATE_IN_RECOVERY then we may not have
1604          * got the command.
1605          */
1606         if (!sc->SCp.ptr) {
1607                 debug_scsi("sc never reached iscsi layer or it completed.\n");
1608                 spin_unlock_bh(&session->lock);
1609                 mutex_unlock(&session->eh_mutex);
1610                 return SUCCESS;
1611         }
1612
1613         /*
1614          * If we are not logged in or we have started a new session
1615          * then let the host reset code handle this
1616          */
1617         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN ||
1618             sc->SCp.phase != session->age) {
1619                 spin_unlock_bh(&session->lock);
1620                 mutex_unlock(&session->eh_mutex);
1621                 return FAILED;
1622         }
1623
1624         conn = session->leadconn;
1625         conn->eh_abort_cnt++;
1626         age = session->age;
1627
1628         task = (struct iscsi_task *)sc->SCp.ptr;
1629         debug_scsi("aborting [sc %p itt 0x%x]\n", sc, task->itt);
1630
1631         /* task completed before time out */
1632         if (!task->sc) {
1633                 debug_scsi("sc completed while abort in progress\n");
1634                 goto success;
1635         }
1636
1637         if (task->state == ISCSI_TASK_PENDING) {
1638                 fail_command(conn, task, DID_ABORT << 16);
1639                 goto success;
1640         }
1641
1642         /* only have one tmf outstanding at a time */
1643         if (conn->tmf_state != TMF_INITIAL)
1644                 goto failed;
1645         conn->tmf_state = TMF_QUEUED;
1646
1647         hdr = &conn->tmhdr;
1648         iscsi_prep_abort_task_pdu(task, hdr);
1649
1650         if (iscsi_exec_task_mgmt_fn(conn, hdr, age, session->abort_timeout)) {
1651                 rc = FAILED;
1652                 goto failed;
1653         }
1654
1655         switch (conn->tmf_state) {
1656         case TMF_SUCCESS:
1657                 spin_unlock_bh(&session->lock);
1658                 /*
1659                  * stop tx side incase the target had sent a abort rsp but
1660                  * the initiator was still writing out data.
1661                  */
1662                 iscsi_suspend_tx(conn);
1663                 /*
1664                  * we do not stop the recv side because targets have been
1665                  * good and have never sent us a successful tmf response
1666                  * then sent more data for the cmd.
1667                  */
1668                 spin_lock(&session->lock);
1669                 fail_command(conn, task, DID_ABORT << 16);
1670                 conn->tmf_state = TMF_INITIAL;
1671                 spin_unlock(&session->lock);
1672                 iscsi_start_tx(conn);
1673                 goto success_unlocked;
1674         case TMF_TIMEDOUT:
1675                 spin_unlock_bh(&session->lock);
1676                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1677                 goto failed_unlocked;
1678         case TMF_NOT_FOUND:
1679                 if (!sc->SCp.ptr) {
1680                         conn->tmf_state = TMF_INITIAL;
1681                         /* task completed before tmf abort response */
1682                         debug_scsi("sc completed while abort in progress\n");
1683                         goto success;
1684                 }
1685                 /* fall through */
1686         default:
1687                 conn->tmf_state = TMF_INITIAL;
1688                 goto failed;
1689         }
1690
1691 success:
1692         spin_unlock_bh(&session->lock);
1693 success_unlocked:
1694         debug_scsi("abort success [sc %lx itt 0x%x]\n", (long)sc, task->itt);
1695         mutex_unlock(&session->eh_mutex);
1696         return SUCCESS;
1697
1698 failed:
1699         spin_unlock_bh(&session->lock);
1700 failed_unlocked:
1701         debug_scsi("abort failed [sc %p itt 0x%x]\n", sc,
1702                     task ? task->itt : 0);
1703         mutex_unlock(&session->eh_mutex);
1704         return FAILED;
1705 }
1706 EXPORT_SYMBOL_GPL(iscsi_eh_abort);
1707
1708 static void iscsi_prep_lun_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
1709 {
1710         memset(hdr, 0, sizeof(*hdr));
1711         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
1712         hdr->flags = ISCSI_TM_FUNC_LOGICAL_UNIT_RESET & ISCSI_FLAG_TM_FUNC_MASK;
1713         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
1714         int_to_scsilun(sc->device->lun, (struct scsi_lun *)hdr->lun);
1715         hdr->rtt = RESERVED_ITT;
1716 }
1717
1718 int iscsi_eh_device_reset(struct scsi_cmnd *sc)
1719 {
1720         struct iscsi_cls_session *cls_session;
1721         struct iscsi_session *session;
1722         struct iscsi_conn *conn;
1723         struct iscsi_tm *hdr;
1724         int rc = FAILED;
1725
1726         cls_session = starget_to_session(scsi_target(sc->device));
1727         session = cls_session->dd_data;
1728
1729         debug_scsi("LU Reset [sc %p lun %u]\n", sc, sc->device->lun);
1730
1731         mutex_lock(&session->eh_mutex);
1732         spin_lock_bh(&session->lock);
1733         /*
1734          * Just check if we are not logged in. We cannot check for
1735          * the phase because the reset could come from a ioctl.
1736          */
1737         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
1738                 goto unlock;
1739         conn = session->leadconn;
1740
1741         /* only have one tmf outstanding at a time */
1742         if (conn->tmf_state != TMF_INITIAL)
1743                 goto unlock;
1744         conn->tmf_state = TMF_QUEUED;
1745
1746         hdr = &conn->tmhdr;
1747         iscsi_prep_lun_reset_pdu(sc, hdr);
1748
1749         if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
1750                                     session->lu_reset_timeout)) {
1751                 rc = FAILED;
1752                 goto unlock;
1753         }
1754
1755         switch (conn->tmf_state) {
1756         case TMF_SUCCESS:
1757                 break;
1758         case TMF_TIMEDOUT:
1759                 spin_unlock_bh(&session->lock);
1760                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1761                 goto done;
1762         default:
1763                 conn->tmf_state = TMF_INITIAL;
1764                 goto unlock;
1765         }
1766
1767         rc = SUCCESS;
1768         spin_unlock_bh(&session->lock);
1769
1770         iscsi_suspend_tx(conn);
1771
1772         spin_lock(&session->lock);
1773         fail_all_commands(conn, sc->device->lun, DID_ERROR);
1774         conn->tmf_state = TMF_INITIAL;
1775         spin_unlock(&session->lock);
1776
1777         iscsi_start_tx(conn);
1778         goto done;
1779
1780 unlock:
1781         spin_unlock_bh(&session->lock);
1782 done:
1783         debug_scsi("iscsi_eh_device_reset %s\n",
1784                   rc == SUCCESS ? "SUCCESS" : "FAILED");
1785         mutex_unlock(&session->eh_mutex);
1786         return rc;
1787 }
1788 EXPORT_SYMBOL_GPL(iscsi_eh_device_reset);
1789
1790 /*
1791  * Pre-allocate a pool of @max items of @item_size. By default, the pool
1792  * should be accessed via kfifo_{get,put} on q->queue.
1793  * Optionally, the caller can obtain the array of object pointers
1794  * by passing in a non-NULL @items pointer
1795  */
1796 int
1797 iscsi_pool_init(struct iscsi_pool *q, int max, void ***items, int item_size)
1798 {
1799         int i, num_arrays = 1;
1800
1801         memset(q, 0, sizeof(*q));
1802
1803         q->max = max;
1804
1805         /* If the user passed an items pointer, he wants a copy of
1806          * the array. */
1807         if (items)
1808                 num_arrays++;
1809         q->pool = kzalloc(num_arrays * max * sizeof(void*), GFP_KERNEL);
1810         if (q->pool == NULL)
1811                 goto enomem;
1812
1813         q->queue = kfifo_init((void*)q->pool, max * sizeof(void*),
1814                               GFP_KERNEL, NULL);
1815         if (q->queue == ERR_PTR(-ENOMEM))
1816                 goto enomem;
1817
1818         for (i = 0; i < max; i++) {
1819                 q->pool[i] = kzalloc(item_size, GFP_KERNEL);
1820                 if (q->pool[i] == NULL) {
1821                         q->max = i;
1822                         goto enomem;
1823                 }
1824                 __kfifo_put(q->queue, (void*)&q->pool[i], sizeof(void*));
1825         }
1826
1827         if (items) {
1828                 *items = q->pool + max;
1829                 memcpy(*items, q->pool, max * sizeof(void *));
1830         }
1831
1832         return 0;
1833
1834 enomem:
1835         iscsi_pool_free(q);
1836         return -ENOMEM;
1837 }
1838 EXPORT_SYMBOL_GPL(iscsi_pool_init);
1839
1840 void iscsi_pool_free(struct iscsi_pool *q)
1841 {
1842         int i;
1843
1844         for (i = 0; i < q->max; i++)
1845                 kfree(q->pool[i]);
1846         if (q->pool)
1847                 kfree(q->pool);
1848 }
1849 EXPORT_SYMBOL_GPL(iscsi_pool_free);
1850
1851 /**
1852  * iscsi_host_add - add host to system
1853  * @shost: scsi host
1854  * @pdev: parent device
1855  *
1856  * This should be called by partial offload and software iscsi drivers
1857  * to add a host to the system.
1858  */
1859 int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev)
1860 {
1861         if (!shost->can_queue)
1862                 shost->can_queue = ISCSI_DEF_XMIT_CMDS_MAX;
1863
1864         return scsi_add_host(shost, pdev);
1865 }
1866 EXPORT_SYMBOL_GPL(iscsi_host_add);
1867
1868 /**
1869  * iscsi_host_alloc - allocate a host and driver data
1870  * @sht: scsi host template
1871  * @dd_data_size: driver host data size
1872  * @qdepth: default device queue depth
1873  *
1874  * This should be called by partial offload and software iscsi drivers.
1875  * To access the driver specific memory use the iscsi_host_priv() macro.
1876  */
1877 struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
1878                                    int dd_data_size, uint16_t qdepth)
1879 {
1880         struct Scsi_Host *shost;
1881
1882         shost = scsi_host_alloc(sht, sizeof(struct iscsi_host) + dd_data_size);
1883         if (!shost)
1884                 return NULL;
1885         shost->transportt->eh_timed_out = iscsi_eh_cmd_timed_out;
1886
1887         if (qdepth > ISCSI_MAX_CMD_PER_LUN || qdepth < 1) {
1888                 if (qdepth != 0)
1889                         printk(KERN_ERR "iscsi: invalid queue depth of %d. "
1890                                "Queue depth must be between 1 and %d.\n",
1891                                qdepth, ISCSI_MAX_CMD_PER_LUN);
1892                 qdepth = ISCSI_DEF_CMD_PER_LUN;
1893         }
1894         shost->cmd_per_lun = qdepth;
1895         return shost;
1896 }
1897 EXPORT_SYMBOL_GPL(iscsi_host_alloc);
1898
1899 /**
1900  * iscsi_host_remove - remove host and sessions
1901  * @shost: scsi host
1902  *
1903  * This will also remove any sessions attached to the host, but if userspace
1904  * is managing the session at the same time this will break. TODO: add
1905  * refcounting to the netlink iscsi interface so a rmmod or host hot unplug
1906  * does not remove the memory from under us.
1907  */
1908 void iscsi_host_remove(struct Scsi_Host *shost)
1909 {
1910         iscsi_host_for_each_session(shost, iscsi_session_teardown);
1911         scsi_remove_host(shost);
1912 }
1913 EXPORT_SYMBOL_GPL(iscsi_host_remove);
1914
1915 void iscsi_host_free(struct Scsi_Host *shost)
1916 {
1917         struct iscsi_host *ihost = shost_priv(shost);
1918
1919         kfree(ihost->netdev);
1920         kfree(ihost->hwaddress);
1921         kfree(ihost->initiatorname);
1922         scsi_host_put(shost);
1923 }
1924 EXPORT_SYMBOL_GPL(iscsi_host_free);
1925
1926 /**
1927  * iscsi_session_setup - create iscsi cls session and host and session
1928  * @iscsit: iscsi transport template
1929  * @shost: scsi host
1930  * @cmds_max: session can queue
1931  * @cmd_task_size: LLD task private data size
1932  * @initial_cmdsn: initial CmdSN
1933  *
1934  * This can be used by software iscsi_transports that allocate
1935  * a session per scsi host.
1936  *
1937  * Callers should set cmds_max to the largest total numer (mgmt + scsi) of
1938  * tasks they support. The iscsi layer reserves ISCSI_MGMT_CMDS_MAX tasks
1939  * for nop handling and login/logout requests.
1940  */
1941 struct iscsi_cls_session *
1942 iscsi_session_setup(struct iscsi_transport *iscsit, struct Scsi_Host *shost,
1943                     uint16_t cmds_max, int cmd_task_size,
1944                     uint32_t initial_cmdsn, unsigned int id)
1945 {
1946         struct iscsi_session *session;
1947         struct iscsi_cls_session *cls_session;
1948         int cmd_i, scsi_cmds, total_cmds = cmds_max;
1949
1950         if (!total_cmds)
1951                 total_cmds = ISCSI_DEF_XMIT_CMDS_MAX;
1952         /*
1953          * The iscsi layer needs some tasks for nop handling and tmfs,
1954          * so the cmds_max must at least be greater than ISCSI_MGMT_CMDS_MAX
1955          * + 1 command for scsi IO.
1956          */
1957         if (total_cmds < ISCSI_TOTAL_CMDS_MIN) {
1958                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
1959                        "must be a power of two that is at least %d.\n",
1960                        total_cmds, ISCSI_TOTAL_CMDS_MIN);
1961                 return NULL;
1962         }
1963
1964         if (total_cmds > ISCSI_TOTAL_CMDS_MAX) {
1965                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
1966                        "must be a power of 2 less than or equal to %d.\n",
1967                        cmds_max, ISCSI_TOTAL_CMDS_MAX);
1968                 total_cmds = ISCSI_TOTAL_CMDS_MAX;
1969         }
1970
1971         if (!is_power_of_2(total_cmds)) {
1972                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
1973                        "must be a power of 2.\n", total_cmds);
1974                 total_cmds = rounddown_pow_of_two(total_cmds);
1975                 if (total_cmds < ISCSI_TOTAL_CMDS_MIN)
1976                         return NULL;
1977                 printk(KERN_INFO "iscsi: Rounding can_queue to %d.\n",
1978                        total_cmds);
1979         }
1980         scsi_cmds = total_cmds - ISCSI_MGMT_CMDS_MAX;
1981
1982         cls_session = iscsi_alloc_session(shost, iscsit,
1983                                           sizeof(struct iscsi_session));
1984         if (!cls_session)
1985                 return NULL;
1986         session = cls_session->dd_data;
1987         session->cls_session = cls_session;
1988         session->host = shost;
1989         session->state = ISCSI_STATE_FREE;
1990         session->fast_abort = 1;
1991         session->lu_reset_timeout = 15;
1992         session->abort_timeout = 10;
1993         session->scsi_cmds_max = scsi_cmds;
1994         session->cmds_max = total_cmds;
1995         session->queued_cmdsn = session->cmdsn = initial_cmdsn;
1996         session->exp_cmdsn = initial_cmdsn + 1;
1997         session->max_cmdsn = initial_cmdsn + 1;
1998         session->max_r2t = 1;
1999         session->tt = iscsit;
2000         mutex_init(&session->eh_mutex);
2001         spin_lock_init(&session->lock);
2002
2003         /* initialize SCSI PDU commands pool */
2004         if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
2005                             (void***)&session->cmds,
2006                             cmd_task_size + sizeof(struct iscsi_task)))
2007                 goto cmdpool_alloc_fail;
2008
2009         /* pre-format cmds pool with ITT */
2010         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
2011                 struct iscsi_task *task = session->cmds[cmd_i];
2012
2013                 if (cmd_task_size)
2014                         task->dd_data = &task[1];
2015                 task->itt = cmd_i;
2016                 INIT_LIST_HEAD(&task->running);
2017         }
2018
2019         if (!try_module_get(iscsit->owner))
2020                 goto module_get_fail;
2021
2022         if (iscsi_add_session(cls_session, id))
2023                 goto cls_session_fail;
2024         return cls_session;
2025
2026 cls_session_fail:
2027         module_put(iscsit->owner);
2028 module_get_fail:
2029         iscsi_pool_free(&session->cmdpool);
2030 cmdpool_alloc_fail:
2031         iscsi_free_session(cls_session);
2032         return NULL;
2033 }
2034 EXPORT_SYMBOL_GPL(iscsi_session_setup);
2035
2036 /**
2037  * iscsi_session_teardown - destroy session, host, and cls_session
2038  * @cls_session: iscsi session
2039  *
2040  * The driver must have called iscsi_remove_session before
2041  * calling this.
2042  */
2043 void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
2044 {
2045         struct iscsi_session *session = cls_session->dd_data;
2046         struct module *owner = cls_session->transport->owner;
2047
2048         iscsi_pool_free(&session->cmdpool);
2049
2050         kfree(session->password);
2051         kfree(session->password_in);
2052         kfree(session->username);
2053         kfree(session->username_in);
2054         kfree(session->targetname);
2055         kfree(session->initiatorname);
2056         kfree(session->ifacename);
2057
2058         iscsi_destroy_session(cls_session);
2059         module_put(owner);
2060 }
2061 EXPORT_SYMBOL_GPL(iscsi_session_teardown);
2062
2063 /**
2064  * iscsi_conn_setup - create iscsi_cls_conn and iscsi_conn
2065  * @cls_session: iscsi_cls_session
2066  * @dd_size: private driver data size
2067  * @conn_idx: cid
2068  */
2069 struct iscsi_cls_conn *
2070 iscsi_conn_setup(struct iscsi_cls_session *cls_session, int dd_size,
2071                  uint32_t conn_idx)
2072 {
2073         struct iscsi_session *session = cls_session->dd_data;
2074         struct iscsi_conn *conn;
2075         struct iscsi_cls_conn *cls_conn;
2076         char *data;
2077
2078         cls_conn = iscsi_create_conn(cls_session, sizeof(*conn) + dd_size,
2079                                      conn_idx);
2080         if (!cls_conn)
2081                 return NULL;
2082         conn = cls_conn->dd_data;
2083         memset(conn, 0, sizeof(*conn) + dd_size);
2084
2085         conn->dd_data = cls_conn->dd_data + sizeof(*conn);
2086         conn->session = session;
2087         conn->cls_conn = cls_conn;
2088         conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
2089         conn->id = conn_idx;
2090         conn->exp_statsn = 0;
2091         conn->tmf_state = TMF_INITIAL;
2092
2093         init_timer(&conn->transport_timer);
2094         conn->transport_timer.data = (unsigned long)conn;
2095         conn->transport_timer.function = iscsi_check_transport_timeouts;
2096
2097         INIT_LIST_HEAD(&conn->run_list);
2098         INIT_LIST_HEAD(&conn->mgmt_run_list);
2099         INIT_LIST_HEAD(&conn->mgmtqueue);
2100         INIT_LIST_HEAD(&conn->xmitqueue);
2101         INIT_LIST_HEAD(&conn->requeue);
2102         INIT_WORK(&conn->xmitwork, iscsi_xmitworker);
2103
2104         /* allocate login_task used for the login/text sequences */
2105         spin_lock_bh(&session->lock);
2106         if (!__kfifo_get(session->cmdpool.queue,
2107                          (void*)&conn->login_task,
2108                          sizeof(void*))) {
2109                 spin_unlock_bh(&session->lock);
2110                 goto login_task_alloc_fail;
2111         }
2112         spin_unlock_bh(&session->lock);
2113
2114         data = kmalloc(ISCSI_DEF_MAX_RECV_SEG_LEN, GFP_KERNEL);
2115         if (!data)
2116                 goto login_task_data_alloc_fail;
2117         conn->login_task->data = conn->data = data;
2118
2119         init_timer(&conn->tmf_timer);
2120         init_waitqueue_head(&conn->ehwait);
2121
2122         return cls_conn;
2123
2124 login_task_data_alloc_fail:
2125         __kfifo_put(session->cmdpool.queue, (void*)&conn->login_task,
2126                     sizeof(void*));
2127 login_task_alloc_fail:
2128         iscsi_destroy_conn(cls_conn);
2129         return NULL;
2130 }
2131 EXPORT_SYMBOL_GPL(iscsi_conn_setup);
2132
2133 /**
2134  * iscsi_conn_teardown - teardown iscsi connection
2135  * cls_conn: iscsi class connection
2136  *
2137  * TODO: we may need to make this into a two step process
2138  * like scsi-mls remove + put host
2139  */
2140 void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
2141 {
2142         struct iscsi_conn *conn = cls_conn->dd_data;
2143         struct iscsi_session *session = conn->session;
2144         unsigned long flags;
2145
2146         del_timer_sync(&conn->transport_timer);
2147
2148         spin_lock_bh(&session->lock);
2149         conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
2150         if (session->leadconn == conn) {
2151                 /*
2152                  * leading connection? then give up on recovery.
2153                  */
2154                 session->state = ISCSI_STATE_TERMINATE;
2155                 wake_up(&conn->ehwait);
2156         }
2157         spin_unlock_bh(&session->lock);
2158
2159         /*
2160          * Block until all in-progress commands for this connection
2161          * time out or fail.
2162          */
2163         for (;;) {
2164                 spin_lock_irqsave(session->host->host_lock, flags);
2165                 if (!session->host->host_busy) { /* OK for ERL == 0 */
2166                         spin_unlock_irqrestore(session->host->host_lock, flags);
2167                         break;
2168                 }
2169                 spin_unlock_irqrestore(session->host->host_lock, flags);
2170                 msleep_interruptible(500);
2171                 iscsi_conn_printk(KERN_INFO, conn, "iscsi conn_destroy(): "
2172                                   "host_busy %d host_failed %d\n",
2173                                   session->host->host_busy,
2174                                   session->host->host_failed);
2175                 /*
2176                  * force eh_abort() to unblock
2177                  */
2178                 wake_up(&conn->ehwait);
2179         }
2180
2181         /* flush queued up work because we free the connection below */
2182         iscsi_suspend_tx(conn);
2183
2184         spin_lock_bh(&session->lock);
2185         kfree(conn->data);
2186         kfree(conn->persistent_address);
2187         __kfifo_put(session->cmdpool.queue, (void*)&conn->login_task,
2188                     sizeof(void*));
2189         if (session->leadconn == conn)
2190                 session->leadconn = NULL;
2191         spin_unlock_bh(&session->lock);
2192
2193         iscsi_destroy_conn(cls_conn);
2194 }
2195 EXPORT_SYMBOL_GPL(iscsi_conn_teardown);
2196
2197 int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
2198 {
2199         struct iscsi_conn *conn = cls_conn->dd_data;
2200         struct iscsi_session *session = conn->session;
2201
2202         if (!session) {
2203                 iscsi_conn_printk(KERN_ERR, conn,
2204                                   "can't start unbound connection\n");
2205                 return -EPERM;
2206         }
2207
2208         if ((session->imm_data_en || !session->initial_r2t_en) &&
2209              session->first_burst > session->max_burst) {
2210                 iscsi_conn_printk(KERN_INFO, conn, "invalid burst lengths: "
2211                                   "first_burst %d max_burst %d\n",
2212                                   session->first_burst, session->max_burst);
2213                 return -EINVAL;
2214         }
2215
2216         if (conn->ping_timeout && !conn->recv_timeout) {
2217                 iscsi_conn_printk(KERN_ERR, conn, "invalid recv timeout of "
2218                                   "zero. Using 5 seconds\n.");
2219                 conn->recv_timeout = 5;
2220         }
2221
2222         if (conn->recv_timeout && !conn->ping_timeout) {
2223                 iscsi_conn_printk(KERN_ERR, conn, "invalid ping timeout of "
2224                                   "zero. Using 5 seconds.\n");
2225                 conn->ping_timeout = 5;
2226         }
2227
2228         spin_lock_bh(&session->lock);
2229         conn->c_stage = ISCSI_CONN_STARTED;
2230         session->state = ISCSI_STATE_LOGGED_IN;
2231         session->queued_cmdsn = session->cmdsn;
2232
2233         conn->last_recv = jiffies;
2234         conn->last_ping = jiffies;
2235         if (conn->recv_timeout && conn->ping_timeout)
2236                 mod_timer(&conn->transport_timer,
2237                           jiffies + (conn->recv_timeout * HZ));
2238
2239         switch(conn->stop_stage) {
2240         case STOP_CONN_RECOVER:
2241                 /*
2242                  * unblock eh_abort() if it is blocked. re-try all
2243                  * commands after successful recovery
2244                  */
2245                 conn->stop_stage = 0;
2246                 conn->tmf_state = TMF_INITIAL;
2247                 session->age++;
2248                 if (session->age == 16)
2249                         session->age = 0;
2250                 break;
2251         case STOP_CONN_TERM:
2252                 conn->stop_stage = 0;
2253                 break;
2254         default:
2255                 break;
2256         }
2257         spin_unlock_bh(&session->lock);
2258
2259         iscsi_unblock_session(session->cls_session);
2260         wake_up(&conn->ehwait);
2261         return 0;
2262 }
2263 EXPORT_SYMBOL_GPL(iscsi_conn_start);
2264
2265 static void
2266 flush_control_queues(struct iscsi_session *session, struct iscsi_conn *conn)
2267 {
2268         struct iscsi_task *task, *tmp;
2269
2270         /* handle pending */
2271         list_for_each_entry_safe(task, tmp, &conn->mgmtqueue, running) {
2272                 debug_scsi("flushing pending mgmt task itt 0x%x\n", task->itt);
2273                 /* release ref from prep task */
2274                 __iscsi_put_task(task);
2275         }
2276
2277         /* handle running */
2278         list_for_each_entry_safe(task, tmp, &conn->mgmt_run_list, running) {
2279                 debug_scsi("flushing running mgmt task itt 0x%x\n", task->itt);
2280                 /* release ref from prep task */
2281                 __iscsi_put_task(task);
2282         }
2283
2284         conn->task = NULL;
2285 }
2286
2287 static void iscsi_start_session_recovery(struct iscsi_session *session,
2288                                          struct iscsi_conn *conn, int flag)
2289 {
2290         int old_stop_stage;
2291
2292         del_timer_sync(&conn->transport_timer);
2293
2294         mutex_lock(&session->eh_mutex);
2295         spin_lock_bh(&session->lock);
2296         if (conn->stop_stage == STOP_CONN_TERM) {
2297                 spin_unlock_bh(&session->lock);
2298                 mutex_unlock(&session->eh_mutex);
2299                 return;
2300         }
2301
2302         /*
2303          * When this is called for the in_login state, we only want to clean
2304          * up the login task and connection. We do not need to block and set
2305          * the recovery state again
2306          */
2307         if (flag == STOP_CONN_TERM)
2308                 session->state = ISCSI_STATE_TERMINATE;
2309         else if (conn->stop_stage != STOP_CONN_RECOVER)
2310                 session->state = ISCSI_STATE_IN_RECOVERY;
2311
2312         old_stop_stage = conn->stop_stage;
2313         conn->stop_stage = flag;
2314         conn->c_stage = ISCSI_CONN_STOPPED;
2315         spin_unlock_bh(&session->lock);
2316
2317         iscsi_suspend_tx(conn);
2318         /*
2319          * for connection level recovery we should not calculate
2320          * header digest. conn->hdr_size used for optimization
2321          * in hdr_extract() and will be re-negotiated at
2322          * set_param() time.
2323          */
2324         if (flag == STOP_CONN_RECOVER) {
2325                 conn->hdrdgst_en = 0;
2326                 conn->datadgst_en = 0;
2327                 if (session->state == ISCSI_STATE_IN_RECOVERY &&
2328                     old_stop_stage != STOP_CONN_RECOVER) {
2329                         debug_scsi("blocking session\n");
2330                         iscsi_block_session(session->cls_session);
2331                 }
2332         }
2333
2334         /*
2335          * flush queues.
2336          */
2337         spin_lock_bh(&session->lock);
2338         fail_all_commands(conn, -1,
2339                         STOP_CONN_RECOVER ? DID_BUS_BUSY : DID_ERROR);
2340         flush_control_queues(session, conn);
2341         spin_unlock_bh(&session->lock);
2342         mutex_unlock(&session->eh_mutex);
2343 }
2344
2345 void iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
2346 {
2347         struct iscsi_conn *conn = cls_conn->dd_data;
2348         struct iscsi_session *session = conn->session;
2349
2350         switch (flag) {
2351         case STOP_CONN_RECOVER:
2352         case STOP_CONN_TERM:
2353                 iscsi_start_session_recovery(session, conn, flag);
2354                 break;
2355         default:
2356                 iscsi_conn_printk(KERN_ERR, conn,
2357                                   "invalid stop flag %d\n", flag);
2358         }
2359 }
2360 EXPORT_SYMBOL_GPL(iscsi_conn_stop);
2361
2362 int iscsi_conn_bind(struct iscsi_cls_session *cls_session,
2363                     struct iscsi_cls_conn *cls_conn, int is_leading)
2364 {
2365         struct iscsi_session *session = cls_session->dd_data;
2366         struct iscsi_conn *conn = cls_conn->dd_data;
2367
2368         spin_lock_bh(&session->lock);
2369         if (is_leading)
2370                 session->leadconn = conn;
2371         spin_unlock_bh(&session->lock);
2372
2373         /*
2374          * Unblock xmitworker(), Login Phase will pass through.
2375          */
2376         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
2377         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
2378         return 0;
2379 }
2380 EXPORT_SYMBOL_GPL(iscsi_conn_bind);
2381
2382
2383 int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
2384                     enum iscsi_param param, char *buf, int buflen)
2385 {
2386         struct iscsi_conn *conn = cls_conn->dd_data;
2387         struct iscsi_session *session = conn->session;
2388         uint32_t value;
2389
2390         switch(param) {
2391         case ISCSI_PARAM_FAST_ABORT:
2392                 sscanf(buf, "%d", &session->fast_abort);
2393                 break;
2394         case ISCSI_PARAM_ABORT_TMO:
2395                 sscanf(buf, "%d", &session->abort_timeout);
2396                 break;
2397         case ISCSI_PARAM_LU_RESET_TMO:
2398                 sscanf(buf, "%d", &session->lu_reset_timeout);
2399                 break;
2400         case ISCSI_PARAM_PING_TMO:
2401                 sscanf(buf, "%d", &conn->ping_timeout);
2402                 break;
2403         case ISCSI_PARAM_RECV_TMO:
2404                 sscanf(buf, "%d", &conn->recv_timeout);
2405                 break;
2406         case ISCSI_PARAM_MAX_RECV_DLENGTH:
2407                 sscanf(buf, "%d", &conn->max_recv_dlength);
2408                 break;
2409         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
2410                 sscanf(buf, "%d", &conn->max_xmit_dlength);
2411                 break;
2412         case ISCSI_PARAM_HDRDGST_EN:
2413                 sscanf(buf, "%d", &conn->hdrdgst_en);
2414                 break;
2415         case ISCSI_PARAM_DATADGST_EN:
2416                 sscanf(buf, "%d", &conn->datadgst_en);
2417                 break;
2418         case ISCSI_PARAM_INITIAL_R2T_EN:
2419                 sscanf(buf, "%d", &session->initial_r2t_en);
2420                 break;
2421         case ISCSI_PARAM_MAX_R2T:
2422                 sscanf(buf, "%d", &session->max_r2t);
2423                 break;
2424         case ISCSI_PARAM_IMM_DATA_EN:
2425                 sscanf(buf, "%d", &session->imm_data_en);
2426                 break;
2427         case ISCSI_PARAM_FIRST_BURST:
2428                 sscanf(buf, "%d", &session->first_burst);
2429                 break;
2430         case ISCSI_PARAM_MAX_BURST:
2431                 sscanf(buf, "%d", &session->max_burst);
2432                 break;
2433         case ISCSI_PARAM_PDU_INORDER_EN:
2434                 sscanf(buf, "%d", &session->pdu_inorder_en);
2435                 break;
2436         case ISCSI_PARAM_DATASEQ_INORDER_EN:
2437                 sscanf(buf, "%d", &session->dataseq_inorder_en);
2438                 break;
2439         case ISCSI_PARAM_ERL:
2440                 sscanf(buf, "%d", &session->erl);
2441                 break;
2442         case ISCSI_PARAM_IFMARKER_EN:
2443                 sscanf(buf, "%d", &value);
2444                 BUG_ON(value);
2445                 break;
2446         case ISCSI_PARAM_OFMARKER_EN:
2447                 sscanf(buf, "%d", &value);
2448                 BUG_ON(value);
2449                 break;
2450         case ISCSI_PARAM_EXP_STATSN:
2451                 sscanf(buf, "%u", &conn->exp_statsn);
2452                 break;
2453         case ISCSI_PARAM_USERNAME:
2454                 kfree(session->username);
2455                 session->username = kstrdup(buf, GFP_KERNEL);
2456                 if (!session->username)
2457                         return -ENOMEM;
2458                 break;
2459         case ISCSI_PARAM_USERNAME_IN:
2460                 kfree(session->username_in);
2461                 session->username_in = kstrdup(buf, GFP_KERNEL);
2462                 if (!session->username_in)
2463                         return -ENOMEM;
2464                 break;
2465         case ISCSI_PARAM_PASSWORD:
2466                 kfree(session->password);
2467                 session->password = kstrdup(buf, GFP_KERNEL);
2468                 if (!session->password)
2469                         return -ENOMEM;
2470                 break;
2471         case ISCSI_PARAM_PASSWORD_IN:
2472                 kfree(session->password_in);
2473                 session->password_in = kstrdup(buf, GFP_KERNEL);
2474                 if (!session->password_in)
2475                         return -ENOMEM;
2476                 break;
2477         case ISCSI_PARAM_TARGET_NAME:
2478                 /* this should not change between logins */
2479                 if (session->targetname)
2480                         break;
2481
2482                 session->targetname = kstrdup(buf, GFP_KERNEL);
2483                 if (!session->targetname)
2484                         return -ENOMEM;
2485                 break;
2486         case ISCSI_PARAM_TPGT:
2487                 sscanf(buf, "%d", &session->tpgt);
2488                 break;
2489         case ISCSI_PARAM_PERSISTENT_PORT:
2490                 sscanf(buf, "%d", &conn->persistent_port);
2491                 break;
2492         case ISCSI_PARAM_PERSISTENT_ADDRESS:
2493                 /*
2494                  * this is the address returned in discovery so it should
2495                  * not change between logins.
2496                  */
2497                 if (conn->persistent_address)
2498                         break;
2499
2500                 conn->persistent_address = kstrdup(buf, GFP_KERNEL);
2501                 if (!conn->persistent_address)
2502                         return -ENOMEM;
2503                 break;
2504         case ISCSI_PARAM_IFACE_NAME:
2505                 if (!session->ifacename)
2506                         session->ifacename = kstrdup(buf, GFP_KERNEL);
2507                 break;
2508         case ISCSI_PARAM_INITIATOR_NAME:
2509                 if (!session->initiatorname)
2510                         session->initiatorname = kstrdup(buf, GFP_KERNEL);
2511                 break;
2512         default:
2513                 return -ENOSYS;
2514         }
2515
2516         return 0;
2517 }
2518 EXPORT_SYMBOL_GPL(iscsi_set_param);
2519
2520 int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
2521                             enum iscsi_param param, char *buf)
2522 {
2523         struct iscsi_session *session = cls_session->dd_data;
2524         int len;
2525
2526         switch(param) {
2527         case ISCSI_PARAM_FAST_ABORT:
2528                 len = sprintf(buf, "%d\n", session->fast_abort);
2529                 break;
2530         case ISCSI_PARAM_ABORT_TMO:
2531                 len = sprintf(buf, "%d\n", session->abort_timeout);
2532                 break;
2533         case ISCSI_PARAM_LU_RESET_TMO:
2534                 len = sprintf(buf, "%d\n", session->lu_reset_timeout);
2535                 break;
2536         case ISCSI_PARAM_INITIAL_R2T_EN:
2537                 len = sprintf(buf, "%d\n", session->initial_r2t_en);
2538                 break;
2539         case ISCSI_PARAM_MAX_R2T:
2540                 len = sprintf(buf, "%hu\n", session->max_r2t);
2541                 break;
2542         case ISCSI_PARAM_IMM_DATA_EN:
2543                 len = sprintf(buf, "%d\n", session->imm_data_en);
2544                 break;
2545         case ISCSI_PARAM_FIRST_BURST:
2546                 len = sprintf(buf, "%u\n", session->first_burst);
2547                 break;
2548         case ISCSI_PARAM_MAX_BURST:
2549                 len = sprintf(buf, "%u\n", session->max_burst);
2550                 break;
2551         case ISCSI_PARAM_PDU_INORDER_EN:
2552                 len = sprintf(buf, "%d\n", session->pdu_inorder_en);
2553                 break;
2554         case ISCSI_PARAM_DATASEQ_INORDER_EN:
2555                 len = sprintf(buf, "%d\n", session->dataseq_inorder_en);
2556                 break;
2557         case ISCSI_PARAM_ERL:
2558                 len = sprintf(buf, "%d\n", session->erl);
2559                 break;
2560         case ISCSI_PARAM_TARGET_NAME:
2561                 len = sprintf(buf, "%s\n", session->targetname);
2562                 break;
2563         case ISCSI_PARAM_TPGT:
2564                 len = sprintf(buf, "%d\n", session->tpgt);
2565                 break;
2566         case ISCSI_PARAM_USERNAME:
2567                 len = sprintf(buf, "%s\n", session->username);
2568                 break;
2569         case ISCSI_PARAM_USERNAME_IN:
2570                 len = sprintf(buf, "%s\n", session->username_in);
2571                 break;
2572         case ISCSI_PARAM_PASSWORD:
2573                 len = sprintf(buf, "%s\n", session->password);
2574                 break;
2575         case ISCSI_PARAM_PASSWORD_IN:
2576                 len = sprintf(buf, "%s\n", session->password_in);
2577                 break;
2578         case ISCSI_PARAM_IFACE_NAME:
2579                 len = sprintf(buf, "%s\n", session->ifacename);
2580                 break;
2581         case ISCSI_PARAM_INITIATOR_NAME:
2582                 if (!session->initiatorname)
2583                         len = sprintf(buf, "%s\n", "unknown");
2584                 else
2585                         len = sprintf(buf, "%s\n", session->initiatorname);
2586                 break;
2587         default:
2588                 return -ENOSYS;
2589         }
2590
2591         return len;
2592 }
2593 EXPORT_SYMBOL_GPL(iscsi_session_get_param);
2594
2595 int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
2596                          enum iscsi_param param, char *buf)
2597 {
2598         struct iscsi_conn *conn = cls_conn->dd_data;
2599         int len;
2600
2601         switch(param) {
2602         case ISCSI_PARAM_PING_TMO:
2603                 len = sprintf(buf, "%u\n", conn->ping_timeout);
2604                 break;
2605         case ISCSI_PARAM_RECV_TMO:
2606                 len = sprintf(buf, "%u\n", conn->recv_timeout);
2607                 break;
2608         case ISCSI_PARAM_MAX_RECV_DLENGTH:
2609                 len = sprintf(buf, "%u\n", conn->max_recv_dlength);
2610                 break;
2611         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
2612                 len = sprintf(buf, "%u\n", conn->max_xmit_dlength);
2613                 break;
2614         case ISCSI_PARAM_HDRDGST_EN:
2615                 len = sprintf(buf, "%d\n", conn->hdrdgst_en);
2616                 break;
2617         case ISCSI_PARAM_DATADGST_EN:
2618                 len = sprintf(buf, "%d\n", conn->datadgst_en);
2619                 break;
2620         case ISCSI_PARAM_IFMARKER_EN:
2621                 len = sprintf(buf, "%d\n", conn->ifmarker_en);
2622                 break;
2623         case ISCSI_PARAM_OFMARKER_EN:
2624                 len = sprintf(buf, "%d\n", conn->ofmarker_en);
2625                 break;
2626         case ISCSI_PARAM_EXP_STATSN:
2627                 len = sprintf(buf, "%u\n", conn->exp_statsn);
2628                 break;
2629         case ISCSI_PARAM_PERSISTENT_PORT:
2630                 len = sprintf(buf, "%d\n", conn->persistent_port);
2631                 break;
2632         case ISCSI_PARAM_PERSISTENT_ADDRESS:
2633                 len = sprintf(buf, "%s\n", conn->persistent_address);
2634                 break;
2635         default:
2636                 return -ENOSYS;
2637         }
2638
2639         return len;
2640 }
2641 EXPORT_SYMBOL_GPL(iscsi_conn_get_param);
2642
2643 int iscsi_host_get_param(struct Scsi_Host *shost, enum iscsi_host_param param,
2644                          char *buf)
2645 {
2646         struct iscsi_host *ihost = shost_priv(shost);
2647         int len;
2648
2649         switch (param) {
2650         case ISCSI_HOST_PARAM_NETDEV_NAME:
2651                 if (!ihost->netdev)
2652                         len = sprintf(buf, "%s\n", "default");
2653                 else
2654                         len = sprintf(buf, "%s\n", ihost->netdev);
2655                 break;
2656         case ISCSI_HOST_PARAM_HWADDRESS:
2657                 if (!ihost->hwaddress)
2658                         len = sprintf(buf, "%s\n", "default");
2659                 else
2660                         len = sprintf(buf, "%s\n", ihost->hwaddress);
2661                 break;
2662         case ISCSI_HOST_PARAM_INITIATOR_NAME:
2663                 if (!ihost->initiatorname)
2664                         len = sprintf(buf, "%s\n", "unknown");
2665                 else
2666                         len = sprintf(buf, "%s\n", ihost->initiatorname);
2667                 break;
2668         case ISCSI_HOST_PARAM_IPADDRESS:
2669                 if (!strlen(ihost->local_address))
2670                         len = sprintf(buf, "%s\n", "unknown");
2671                 else
2672                         len = sprintf(buf, "%s\n",
2673                                       ihost->local_address);
2674                 break;
2675         default:
2676                 return -ENOSYS;
2677         }
2678
2679         return len;
2680 }
2681 EXPORT_SYMBOL_GPL(iscsi_host_get_param);
2682
2683 int iscsi_host_set_param(struct Scsi_Host *shost, enum iscsi_host_param param,
2684                          char *buf, int buflen)
2685 {
2686         struct iscsi_host *ihost = shost_priv(shost);
2687
2688         switch (param) {
2689         case ISCSI_HOST_PARAM_NETDEV_NAME:
2690                 if (!ihost->netdev)
2691                         ihost->netdev = kstrdup(buf, GFP_KERNEL);
2692                 break;
2693         case ISCSI_HOST_PARAM_HWADDRESS:
2694                 if (!ihost->hwaddress)
2695                         ihost->hwaddress = kstrdup(buf, GFP_KERNEL);
2696                 break;
2697         case ISCSI_HOST_PARAM_INITIATOR_NAME:
2698                 if (!ihost->initiatorname)
2699                         ihost->initiatorname = kstrdup(buf, GFP_KERNEL);
2700                 break;
2701         default:
2702                 return -ENOSYS;
2703         }
2704
2705         return 0;
2706 }
2707 EXPORT_SYMBOL_GPL(iscsi_host_set_param);
2708
2709 MODULE_AUTHOR("Mike Christie");
2710 MODULE_DESCRIPTION("iSCSI library functions");
2711 MODULE_LICENSE("GPL");