err.no 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 static void __iscsi_get_task(struct iscsi_task *task)
 366 {
 367         atomic_inc(&task->refcount);
 368 }
 369
 370 static void __iscsi_put_task(struct iscsi_task *task)
 371 {
 372         if (atomic_dec_and_test(&task->refcount))
 373                 iscsi_complete_command(task);
 374 }
 375
 376 void iscsi_put_task(struct iscsi_task *task)
 377 {
 378         struct iscsi_session *session = task->conn->session;
 379
 380         spin_lock_bh(&session->lock);
 381         __iscsi_put_task(task);
 382         spin_unlock_bh(&session->lock);
 383 }
 384 EXPORT_SYMBOL_GPL(iscsi_put_task);
 385
 386 /*
 387  * session lock must be held
 388  */
 389 static void fail_command(struct iscsi_conn *conn, struct iscsi_task *task,
 390                          int err)
 391 {
 392         struct scsi_cmnd *sc;
 393
 394         sc = task->sc;
 395         if (!sc)
 396                 return;
 397
 398         if (task->state == ISCSI_TASK_PENDING)
 399                 /*
 400                  * cmd never made it to the xmit thread, so we should not count
 401                  * the cmd in the sequencing
 402                  */
 403                 conn->session->queued_cmdsn--;
 404         else
 405                 conn->session->tt->cleanup_task(conn, task);
 406
 407         sc->result = err;
 408
 409         if (!scsi_bidi_cmnd(sc))
 410                 scsi_set_resid(sc, scsi_bufflen(sc));
 411         else {
 412                 scsi_out(sc)->resid = scsi_out(sc)->length;
 413                 scsi_in(sc)->resid = scsi_in(sc)->length;
 414         }
 415
 416         if (conn->task == task)
 417                 conn->task = NULL;
 418         /* release ref from queuecommand */
 419         __iscsi_put_task(task);
 420 }
 421
 422 static int iscsi_prep_mgmt_task(struct iscsi_conn *conn,
 423                                 struct iscsi_task *task)
 424 {
 425         struct iscsi_session *session = conn->session;
 426         struct iscsi_hdr *hdr = (struct iscsi_hdr *)task->hdr;
 427         struct iscsi_nopout *nop = (struct iscsi_nopout *)hdr;
 428
 429         if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
 430                 return -ENOTCONN;
 431
 432         if (hdr->opcode != (ISCSI_OP_LOGIN | ISCSI_OP_IMMEDIATE) &&
 433             hdr->opcode != (ISCSI_OP_TEXT | ISCSI_OP_IMMEDIATE))
 434                 nop->exp_statsn = cpu_to_be32(conn->exp_statsn);
 435         /*
 436          * pre-format CmdSN for outgoing PDU.
 437          */
 438         nop->cmdsn = cpu_to_be32(session->cmdsn);
 439         if (hdr->itt != RESERVED_ITT) {
 440                 hdr->itt = build_itt(task->itt, session->age);
 441                 /*
 442                  * TODO: We always use immediate, so we never hit this.
 443                  * If we start to send tmfs or nops as non-immediate then
 444                  * we should start checking the cmdsn numbers for mgmt tasks.
 445                  */
 446                 if (conn->c_stage == ISCSI_CONN_STARTED &&
 447                     !(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
 448                         session->queued_cmdsn++;
 449                         session->cmdsn++;
 450                 }
 451         }
 452
 453         if (session->tt->init_task)
 454                 session->tt->init_task(task);
 455
 456         if ((hdr->opcode & ISCSI_OPCODE_MASK) == ISCSI_OP_LOGOUT)
 457                 session->state = ISCSI_STATE_LOGGING_OUT;
 458
 459         list_move_tail(&task->running, &conn->mgmt_run_list);
 460         debug_scsi("mgmtpdu [op 0x%x hdr->itt 0x%x datalen %d]\n",
 461                    hdr->opcode & ISCSI_OPCODE_MASK, hdr->itt,
 462                    task->data_count);
 463         return 0;
 464 }
 465
 466 static struct iscsi_task *
 467 __iscsi_conn_send_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 468                       char *data, uint32_t data_size)
 469 {
 470         struct iscsi_session *session = conn->session;
 471         struct iscsi_task *task;
 472
 473         if (session->state == ISCSI_STATE_TERMINATE)
 474                 return NULL;
 475
 476         if (hdr->opcode == (ISCSI_OP_LOGIN | ISCSI_OP_IMMEDIATE) ||
 477             hdr->opcode == (ISCSI_OP_TEXT | ISCSI_OP_IMMEDIATE))
 478                 /*
 479                  * Login and Text are sent serially, in
 480                  * request-followed-by-response sequence.
 481                  * Same task can be used. Same ITT must be used.
 482                  * Note that login_task is preallocated at conn_create().
 483                  */
 484                 task = conn->login_task;
 485         else {
 486                 BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
 487                 BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);
 488
 489                 if (!__kfifo_get(session->cmdpool.queue,
 490                                  (void*)&task, sizeof(void*)))
 491                         return NULL;
 492
 493                 if ((hdr->opcode == (ISCSI_OP_NOOP_OUT | ISCSI_OP_IMMEDIATE)) &&
 494                      hdr->ttt == RESERVED_ITT) {
 495                         conn->ping_task = task;
 496                         conn->last_ping = jiffies;
 497                 }
 498         }
 499         /*
 500          * released in complete pdu for task we expect a response for, and
 501          * released by the lld when it has transmitted the task for
 502          * pdus we do not expect a response for.
 503          */
 504         atomic_set(&task->refcount, 1);
 505         task->conn = conn;
 506         task->sc = NULL;
 507
 508         if (data_size) {
 509                 memcpy(task->data, data, data_size);
 510                 task->data_count = data_size;
 511         } else
 512                 task->data_count = 0;
 513
 514         memcpy(task->hdr, hdr, sizeof(struct iscsi_hdr));
 515         INIT_LIST_HEAD(&task->running);
 516         list_add_tail(&task->running, &conn->mgmtqueue);
 517
 518         if (session->tt->caps & CAP_DATA_PATH_OFFLOAD) {
 519                 if (iscsi_prep_mgmt_task(conn, task)) {
 520                         __iscsi_put_task(task);
 521                         return NULL;
 522                 }
 523
 524                 if (session->tt->xmit_task(task))
 525                         task = NULL;
 526
 527         } else
 528                 scsi_queue_work(conn->session->host, &conn->xmitwork);
 529
 530         return task;
 531 }
 532
 533 int iscsi_conn_send_pdu(struct iscsi_cls_conn *cls_conn, struct iscsi_hdr *hdr,
 534                         char *data, uint32_t data_size)
 535 {
 536         struct iscsi_conn *conn = cls_conn->dd_data;
 537         struct iscsi_session *session = conn->session;
 538         int err = 0;
 539
 540         spin_lock_bh(&session->lock);
 541         if (!__iscsi_conn_send_pdu(conn, hdr, data, data_size))
 542                 err = -EPERM;
 543         spin_unlock_bh(&session->lock);
 544         return err;
 545 }
 546 EXPORT_SYMBOL_GPL(iscsi_conn_send_pdu);
 547
 548 /**
 549  * iscsi_cmd_rsp - SCSI Command Response processing
 550  * @conn: iscsi connection
 551  * @hdr: iscsi header
 552  * @task: scsi command task
 553  * @data: cmd data buffer
 554  * @datalen: len of buffer
 555  *
 556  * iscsi_cmd_rsp sets up the scsi_cmnd fields based on the PDU and
 557  * then completes the command and task.
 558  **/
 559 static void iscsi_scsi_cmd_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 560                                struct iscsi_task *task, char *data,
 561                                int datalen)
 562 {
 563         struct iscsi_cmd_rsp *rhdr = (struct iscsi_cmd_rsp *)hdr;
 564         struct iscsi_session *session = conn->session;
 565         struct scsi_cmnd *sc = task->sc;
 566
 567         iscsi_update_cmdsn(session, (struct iscsi_nopin*)rhdr);
 568         conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 569
 570         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 571
 572         if (rhdr->response != ISCSI_STATUS_CMD_COMPLETED) {
 573                 sc->result = DID_ERROR << 16;
 574                 goto out;
 575         }
 576
 577         if (rhdr->cmd_status == SAM_STAT_CHECK_CONDITION) {
 578                 uint16_t senselen;
 579
 580                 if (datalen < 2) {
 581 invalid_datalen:
 582                         iscsi_conn_printk(KERN_ERR,  conn,
 583                                          "Got CHECK_CONDITION but invalid data "
 584                                          "buffer size of %d\n", datalen);
 585                         sc->result = DID_BAD_TARGET << 16;
 586                         goto out;
 587                 }
 588
 589                 senselen = be16_to_cpu(get_unaligned((__be16 *) data));
 590                 if (datalen < senselen)
 591                         goto invalid_datalen;
 592
 593                 memcpy(sc->sense_buffer, data + 2,
 594                        min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
 595                 debug_scsi("copied %d bytes of sense\n",
 596                            min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
 597         }
 598
 599         if (rhdr->flags & (ISCSI_FLAG_CMD_BIDI_UNDERFLOW |
 600                            ISCSI_FLAG_CMD_BIDI_OVERFLOW)) {
 601                 int res_count = be32_to_cpu(rhdr->bi_residual_count);
 602
 603                 if (scsi_bidi_cmnd(sc) && res_count > 0 &&
 604                                 (rhdr->flags & ISCSI_FLAG_CMD_BIDI_OVERFLOW ||
 605                                  res_count <= scsi_in(sc)->length))
 606                         scsi_in(sc)->resid = res_count;
 607                 else
 608                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 609         }
 610
 611         if (rhdr->flags & (ISCSI_FLAG_CMD_UNDERFLOW |
 612                            ISCSI_FLAG_CMD_OVERFLOW)) {
 613                 int res_count = be32_to_cpu(rhdr->residual_count);
 614
 615                 if (res_count > 0 &&
 616                     (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
 617                      res_count <= scsi_bufflen(sc)))
 618                         /* write side for bidi or uni-io set_resid */
 619                         scsi_set_resid(sc, res_count);
 620                 else
 621                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 622         }
 623 out:
 624         debug_scsi("done [sc %lx res %d itt 0x%x]\n",
 625                    (long)sc, sc->result, task->itt);
 626         conn->scsirsp_pdus_cnt++;
 627
 628         __iscsi_put_task(task);
 629 }
 630
 631 static void iscsi_tmf_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
 632 {
 633         struct iscsi_tm_rsp *tmf = (struct iscsi_tm_rsp *)hdr;
 634
 635         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 636         conn->tmfrsp_pdus_cnt++;
 637
 638         if (conn->tmf_state != TMF_QUEUED)
 639                 return;
 640
 641         if (tmf->response == ISCSI_TMF_RSP_COMPLETE)
 642                 conn->tmf_state = TMF_SUCCESS;
 643         else if (tmf->response == ISCSI_TMF_RSP_NO_TASK)
 644                 conn->tmf_state = TMF_NOT_FOUND;
 645         else
 646                 conn->tmf_state = TMF_FAILED;
 647         wake_up(&conn->ehwait);
 648 }
 649
 650 static void iscsi_send_nopout(struct iscsi_conn *conn, struct iscsi_nopin *rhdr)
 651 {
 652         struct iscsi_nopout hdr;
 653         struct iscsi_task *task;
 654
 655         if (!rhdr && conn->ping_task)
 656                 return;
 657
 658         memset(&hdr, 0, sizeof(struct iscsi_nopout));
 659         hdr.opcode = ISCSI_OP_NOOP_OUT | ISCSI_OP_IMMEDIATE;
 660         hdr.flags = ISCSI_FLAG_CMD_FINAL;
 661
 662         if (rhdr) {
 663                 memcpy(hdr.lun, rhdr->lun, 8);
 664                 hdr.ttt = rhdr->ttt;
 665                 hdr.itt = RESERVED_ITT;
 666         } else
 667                 hdr.ttt = RESERVED_ITT;
 668
 669         task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)&hdr, NULL, 0);
 670         if (!task)
 671                 iscsi_conn_printk(KERN_ERR, conn, "Could not send nopout\n");
 672 }
 673
 674 static int iscsi_handle_reject(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 675                                char *data, int datalen)
 676 {
 677         struct iscsi_reject *reject = (struct iscsi_reject *)hdr;
 678         struct iscsi_hdr rejected_pdu;
 679         uint32_t itt;
 680
 681         conn->exp_statsn = be32_to_cpu(reject->statsn) + 1;
 682
 683         if (reject->reason == ISCSI_REASON_DATA_DIGEST_ERROR) {
 684                 if (ntoh24(reject->dlength) > datalen)
 685                         return ISCSI_ERR_PROTO;
 686
 687                 if (ntoh24(reject->dlength) >= sizeof(struct iscsi_hdr)) {
 688                         memcpy(&rejected_pdu, data, sizeof(struct iscsi_hdr));
 689                         itt = get_itt(rejected_pdu.itt);
 690                         iscsi_conn_printk(KERN_ERR, conn,
 691                                           "itt 0x%x had pdu (op 0x%x) rejected "
 692                                           "due to DataDigest error.\n", itt,
 693                                           rejected_pdu.opcode);
 694                 }
 695         }
 696         return 0;
 697 }
 698
 699 /**
 700  * __iscsi_complete_pdu - complete pdu
 701  * @conn: iscsi conn
 702  * @hdr: iscsi header
 703  * @data: data buffer
 704  * @datalen: len of data buffer
 705  *
 706  * Completes pdu processing by freeing any resources allocated at
 707  * queuecommand or send generic. session lock must be held and verify
 708  * itt must have been called.
 709  */
 710 static int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 711                                 char *data, int datalen)
 712 {
 713         struct iscsi_session *session = conn->session;
 714         int opcode = hdr->opcode & ISCSI_OPCODE_MASK, rc = 0;
 715         struct iscsi_task *task;
 716         uint32_t itt;
 717
 718         conn->last_recv = jiffies;
 719         rc = iscsi_verify_itt(conn, hdr->itt);
 720         if (rc)
 721                 return rc;
 722
 723         if (hdr->itt != RESERVED_ITT)
 724                 itt = get_itt(hdr->itt);
 725         else
 726                 itt = ~0U;
 727
 728         debug_scsi("[op 0x%x cid %d itt 0x%x len %d]\n",
 729                    opcode, conn->id, itt, datalen);
 730
 731         if (itt == ~0U) {
 732                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
 733
 734                 switch(opcode) {
 735                 case ISCSI_OP_NOOP_IN:
 736                         if (datalen) {
 737                                 rc = ISCSI_ERR_PROTO;
 738                                 break;
 739                         }
 740
 741                         if (hdr->ttt == cpu_to_be32(ISCSI_RESERVED_TAG))
 742                                 break;
 743
 744                         iscsi_send_nopout(conn, (struct iscsi_nopin*)hdr);
 745                         break;
 746                 case ISCSI_OP_REJECT:
 747                         rc = iscsi_handle_reject(conn, hdr, data, datalen);
 748                         break;
 749                 case ISCSI_OP_ASYNC_EVENT:
 750                         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 751                         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
 752                                 rc = ISCSI_ERR_CONN_FAILED;
 753                         break;
 754                 default:
 755                         rc = ISCSI_ERR_BAD_OPCODE;
 756                         break;
 757                 }
 758                 goto out;
 759         }
 760
 761         task = session->cmds[itt];
 762         switch(opcode) {
 763         case ISCSI_OP_SCSI_CMD_RSP:
 764                 if (!task->sc) {
 765                         rc = ISCSI_ERR_NO_SCSI_CMD;
 766                         break;
 767                 }
 768                 BUG_ON((void*)task != task->sc->SCp.ptr);
 769                 iscsi_scsi_cmd_rsp(conn, hdr, task, data, datalen);
 770                 break;
 771         case ISCSI_OP_SCSI_DATA_IN:
 772                 if (!task->sc) {
 773                         rc = ISCSI_ERR_NO_SCSI_CMD;
 774                         break;
 775                 }
 776                 BUG_ON((void*)task != task->sc->SCp.ptr);
 777                 if (hdr->flags & ISCSI_FLAG_DATA_STATUS) {
 778                         conn->scsirsp_pdus_cnt++;
 779                         iscsi_update_cmdsn(session,
 780                                            (struct iscsi_nopin*) hdr);
 781                         __iscsi_put_task(task);
 782                 }
 783                 break;
 784         case ISCSI_OP_R2T:
 785                 /* LLD handles this for now */
 786                 break;
 787         case ISCSI_OP_LOGOUT_RSP:
 788                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
 789                 if (datalen) {
 790                         rc = ISCSI_ERR_PROTO;
 791                         break;
 792                 }
 793                 conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 794                 goto recv_pdu;
 795         case ISCSI_OP_LOGIN_RSP:
 796         case ISCSI_OP_TEXT_RSP:
 797                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
 798                 /*
 799                  * login related PDU's exp_statsn is handled in
 800                  * userspace
 801                  */
 802                 goto recv_pdu;
 803         case ISCSI_OP_SCSI_TMFUNC_RSP:
 804                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
 805                 if (datalen) {
 806                         rc = ISCSI_ERR_PROTO;
 807                         break;
 808                 }
 809
 810                 iscsi_tmf_rsp(conn, hdr);
 811                 __iscsi_put_task(task);
 812                 break;
 813         case ISCSI_OP_NOOP_IN:
 814                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
 815                 if (hdr->ttt != cpu_to_be32(ISCSI_RESERVED_TAG) || datalen) {
 816                         rc = ISCSI_ERR_PROTO;
 817                         break;
 818                 }
 819                 conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 820
 821                 if (conn->ping_task != task)
 822                         /*
 823                          * If this is not in response to one of our
 824                          * nops then it must be from userspace.
 825                          */
 826                         goto recv_pdu;
 827
 828                 mod_timer(&conn->transport_timer, jiffies + conn->recv_timeout);
 829                 __iscsi_put_task(task);
 830                 break;
 831         default:
 832                 rc = ISCSI_ERR_BAD_OPCODE;
 833                 break;
 834         }
 835
 836 out:
 837         return rc;
 838 recv_pdu:
 839         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
 840                 rc = ISCSI_ERR_CONN_FAILED;
 841         __iscsi_put_task(task);
 842         return rc;
 843 }
 844
 845 int iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 846                        char *data, int datalen)
 847 {
 848         int rc;
 849
 850         spin_lock(&conn->session->lock);
 851         rc = __iscsi_complete_pdu(conn, hdr, data, datalen);
 852         spin_unlock(&conn->session->lock);
 853         return rc;
 854 }
 855 EXPORT_SYMBOL_GPL(iscsi_complete_pdu);
 856
 857 int iscsi_verify_itt(struct iscsi_conn *conn, itt_t itt)
 858 {
 859         struct iscsi_session *session = conn->session;
 860         struct iscsi_task *task;
 861         uint32_t i;
 862
 863         if (itt == RESERVED_ITT)
 864                 return 0;
 865
 866         if (((__force u32)itt & ISCSI_AGE_MASK) !=
 867             (session->age << ISCSI_AGE_SHIFT)) {
 868                 iscsi_conn_printk(KERN_ERR, conn,
 869                                   "received itt %x expected session age (%x)\n",
 870                                   (__force u32)itt,
 871                                   session->age & ISCSI_AGE_MASK);
 872                 return ISCSI_ERR_BAD_ITT;
 873         }
 874
 875         i = get_itt(itt);
 876         if (i >= session->cmds_max) {
 877                 iscsi_conn_printk(KERN_ERR, conn,
 878                                   "received invalid itt index %u (max cmds "
 879                                    "%u.\n", i, session->cmds_max);
 880                 return ISCSI_ERR_BAD_ITT;
 881         }
 882
 883         task = session->cmds[i];
 884         if (task->sc && task->sc->SCp.phase != session->age) {
 885                 iscsi_conn_printk(KERN_ERR, conn,
 886                                   "iscsi: task's session age %d, "
 887                                   "expected %d\n", task->sc->SCp.phase,
 888                                   session->age);
 889                 return ISCSI_ERR_SESSION_FAILED;
 890         }
 891         return 0;
 892 }
 893 EXPORT_SYMBOL_GPL(iscsi_verify_itt);
 894
 895 struct iscsi_task *
 896 iscsi_itt_to_ctask(struct iscsi_conn *conn, itt_t itt)
 897 {
 898         struct iscsi_session *session = conn->session;
 899         struct iscsi_task *task;
 900         uint32_t i;
 901
 902         if (iscsi_verify_itt(conn, itt))
 903                 return NULL;
 904
 905         if (itt == RESERVED_ITT)
 906                 return NULL;
 907
 908         i = get_itt(itt);
 909         if (i >= session->cmds_max)
 910                 return NULL;
 911
 912         task = session->cmds[i];
 913         if (!task->sc)
 914                 return NULL;
 915
 916         if (task->sc->SCp.phase != session->age)
 917                 return NULL;
 918
 919         return task;
 920 }
 921 EXPORT_SYMBOL_GPL(iscsi_itt_to_ctask);
 922
 923 void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err)
 924 {
 925         struct iscsi_session *session = conn->session;
 926         unsigned long flags;
 927
 928         spin_lock_irqsave(&session->lock, flags);
 929         if (session->state == ISCSI_STATE_FAILED) {
 930                 spin_unlock_irqrestore(&session->lock, flags);
 931                 return;
 932         }
 933
 934         if (conn->stop_stage == 0)
 935                 session->state = ISCSI_STATE_FAILED;
 936         spin_unlock_irqrestore(&session->lock, flags);
 937         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
 938         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
 939         iscsi_conn_error(conn->cls_conn, err);
 940 }
 941 EXPORT_SYMBOL_GPL(iscsi_conn_failure);
 942
 943 static int iscsi_check_cmdsn_window_closed(struct iscsi_conn *conn)
 944 {
 945         struct iscsi_session *session = conn->session;
 946
 947         /*
 948          * Check for iSCSI window and take care of CmdSN wrap-around
 949          */
 950         if (!iscsi_sna_lte(session->queued_cmdsn, session->max_cmdsn)) {
 951                 debug_scsi("iSCSI CmdSN closed. ExpCmdSn %u MaxCmdSN %u "
 952                            "CmdSN %u/%u\n", session->exp_cmdsn,
 953                            session->max_cmdsn, session->cmdsn,
 954                            session->queued_cmdsn);
 955                 return -ENOSPC;
 956         }
 957         return 0;
 958 }
 959
 960 static int iscsi_xmit_task(struct iscsi_conn *conn)
 961 {
 962         struct iscsi_task *task = conn->task;
 963         int rc;
 964
 965         __iscsi_get_task(task);
 966         spin_unlock_bh(&conn->session->lock);
 967         rc = conn->session->tt->xmit_task(task);
 968         spin_lock_bh(&conn->session->lock);
 969         __iscsi_put_task(task);
 970         if (!rc)
 971                 /* done with this task */
 972                 conn->task = NULL;
 973         return rc;
 974 }
 975
 976 /**
 977  * iscsi_requeue_task - requeue task to run from session workqueue
 978  * @task: task to requeue
 979  *
 980  * LLDs that need to run a task from the session workqueue should call
 981  * this. The session lock must be held. This should only be called
 982  * by software drivers.
 983  */
 984 void iscsi_requeue_task(struct iscsi_task *task)
 985 {
 986         struct iscsi_conn *conn = task->conn;
 987
 988         list_move_tail(&task->running, &conn->requeue);
 989         scsi_queue_work(conn->session->host, &conn->xmitwork);
 990 }
 991 EXPORT_SYMBOL_GPL(iscsi_requeue_task);
 992
 993 /**
 994  * iscsi_data_xmit - xmit any command into the scheduled connection
 995  * @conn: iscsi connection
 996  *
 997  * Notes:
 998  *      The function can return -EAGAIN in which case the caller must
 999  *      re-schedule it again later or recover. '0' return code means
1000  *      successful xmit.
1001  **/
1002 static int iscsi_data_xmit(struct iscsi_conn *conn)
1003 {
1004         int rc = 0;
1005
1006         spin_lock_bh(&conn->session->lock);
1007         if (unlikely(conn->suspend_tx)) {
1008                 debug_scsi("conn %d Tx suspended!\n", conn->id);
1009                 spin_unlock_bh(&conn->session->lock);
1010                 return -ENODATA;
1011         }
1012
1013         if (conn->task) {
1014                 rc = iscsi_xmit_task(conn);
1015                 if (rc)
1016                         goto again;
1017         }
1018
1019         /*
1020          * process mgmt pdus like nops before commands since we should
1021          * only have one nop-out as a ping from us and targets should not
1022          * overflow us with nop-ins
1023          */
1024 check_mgmt:
1025         while (!list_empty(&conn->mgmtqueue)) {
1026                 conn->task = list_entry(conn->mgmtqueue.next,
1027                                          struct iscsi_task, running);
1028                 if (iscsi_prep_mgmt_task(conn, conn->task)) {
1029                         __iscsi_put_task(conn->task);
1030                         conn->task = NULL;
1031                         continue;
1032                 }
1033                 rc = iscsi_xmit_task(conn);
1034                 if (rc)
1035                         goto again;
1036         }
1037
1038         /* process pending command queue */
1039         while (!list_empty(&conn->xmitqueue)) {
1040                 if (conn->tmf_state == TMF_QUEUED)
1041                         break;
1042
1043                 conn->task = list_entry(conn->xmitqueue.next,
1044                                          struct iscsi_task, running);
1045                 if (conn->session->state == ISCSI_STATE_LOGGING_OUT) {
1046                         fail_command(conn, conn->task, DID_IMM_RETRY << 16);
1047                         continue;
1048                 }
1049                 if (iscsi_prep_scsi_cmd_pdu(conn->task)) {
1050                         fail_command(conn, conn->task, DID_ABORT << 16);
1051                         continue;
1052                 }
1053                 rc = iscsi_xmit_task(conn);
1054                 if (rc)
1055                         goto again;
1056                 /*
1057                  * we could continuously get new task requests so
1058                  * we need to check the mgmt queue for nops that need to
1059                  * be sent to aviod starvation
1060                  */
1061                 if (!list_empty(&conn->mgmtqueue))
1062                         goto check_mgmt;
1063         }
1064
1065         while (!list_empty(&conn->requeue)) {
1066                 if (conn->session->fast_abort && conn->tmf_state != TMF_INITIAL)
1067                         break;
1068
1069                 /*
1070                  * we always do fastlogout - conn stop code will clean up.
1071                  */
1072                 if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
1073                         break;
1074
1075                 conn->task = list_entry(conn->requeue.next,
1076                                          struct iscsi_task, running);
1077                 conn->task->state = ISCSI_TASK_RUNNING;
1078                 list_move_tail(conn->requeue.next, &conn->run_list);
1079                 rc = iscsi_xmit_task(conn);
1080                 if (rc)
1081                         goto again;
1082                 if (!list_empty(&conn->mgmtqueue))
1083                         goto check_mgmt;
1084         }
1085         spin_unlock_bh(&conn->session->lock);
1086         return -ENODATA;
1087
1088 again:
1089         if (unlikely(conn->suspend_tx))
1090                 rc = -ENODATA;
1091         spin_unlock_bh(&conn->session->lock);
1092         return rc;
1093 }
1094
1095 static void iscsi_xmitworker(struct work_struct *work)
1096 {
1097         struct iscsi_conn *conn =
1098                 container_of(work, struct iscsi_conn, xmitwork);
1099         int rc;
1100         /*
1101          * serialize Xmit worker on a per-connection basis.
1102          */
1103         do {
1104                 rc = iscsi_data_xmit(conn);
1105         } while (rc >= 0 || rc == -EAGAIN);
1106 }
1107
1108 enum {
1109         FAILURE_BAD_HOST = 1,
1110         FAILURE_SESSION_FAILED,
1111         FAILURE_SESSION_FREED,
1112         FAILURE_WINDOW_CLOSED,
1113         FAILURE_OOM,
1114         FAILURE_SESSION_TERMINATE,
1115         FAILURE_SESSION_IN_RECOVERY,
1116         FAILURE_SESSION_RECOVERY_TIMEOUT,
1117         FAILURE_SESSION_LOGGING_OUT,
1118         FAILURE_SESSION_NOT_READY,
1119 };
1120
1121 int iscsi_queuecommand(struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *))
1122 {
1123         struct iscsi_cls_session *cls_session;
1124         struct Scsi_Host *host;
1125         int reason = 0;
1126         struct iscsi_session *session;
1127         struct iscsi_conn *conn;
1128         struct iscsi_task *task = NULL;
1129
1130         sc->scsi_done = done;
1131         sc->result = 0;
1132         sc->SCp.ptr = NULL;
1133
1134         host = sc->device->host;
1135         spin_unlock(host->host_lock);
1136
1137         cls_session = starget_to_session(scsi_target(sc->device));
1138         session = cls_session->dd_data;
1139         spin_lock(&session->lock);
1140
1141         reason = iscsi_session_chkready(cls_session);
1142         if (reason) {
1143                 sc->result = reason;
1144                 goto fault;
1145         }
1146
1147         /*
1148          * ISCSI_STATE_FAILED is a temp. state. The recovery
1149          * code will decide what is best to do with command queued
1150          * during this time
1151          */
1152         if (session->state != ISCSI_STATE_LOGGED_IN &&
1153             session->state != ISCSI_STATE_FAILED) {
1154                 /*
1155                  * to handle the race between when we set the recovery state
1156                  * and block the session we requeue here (commands could
1157                  * be entering our queuecommand while a block is starting
1158                  * up because the block code is not locked)
1159                  */
1160                 switch (session->state) {
1161                 case ISCSI_STATE_IN_RECOVERY:
1162                         reason = FAILURE_SESSION_IN_RECOVERY;
1163                         sc->result = DID_IMM_RETRY << 16;
1164                         break;
1165                 case ISCSI_STATE_LOGGING_OUT:
1166                         reason = FAILURE_SESSION_LOGGING_OUT;
1167                         sc->result = DID_IMM_RETRY << 16;
1168                         break;
1169                 case ISCSI_STATE_RECOVERY_FAILED:
1170                         reason = FAILURE_SESSION_RECOVERY_TIMEOUT;
1171                         sc->result = DID_NO_CONNECT << 16;
1172                         break;
1173                 case ISCSI_STATE_TERMINATE:
1174                         reason = FAILURE_SESSION_TERMINATE;
1175                         sc->result = DID_NO_CONNECT << 16;
1176                         break;
1177                 default:
1178                         reason = FAILURE_SESSION_FREED;
1179                         sc->result = DID_NO_CONNECT << 16;
1180                 }
1181                 goto fault;
1182         }
1183
1184         conn = session->leadconn;
1185         if (!conn) {
1186                 reason = FAILURE_SESSION_FREED;
1187                 sc->result = DID_NO_CONNECT << 16;
1188                 goto fault;
1189         }
1190
1191         if (iscsi_check_cmdsn_window_closed(conn)) {
1192                 reason = FAILURE_WINDOW_CLOSED;
1193                 goto reject;
1194         }
1195
1196         if (!__kfifo_get(session->cmdpool.queue, (void*)&task,
1197                          sizeof(void*))) {
1198                 reason = FAILURE_OOM;
1199                 goto reject;
1200         }
1201         sc->SCp.phase = session->age;
1202         sc->SCp.ptr = (char *)task;
1203
1204         atomic_set(&task->refcount, 1);
1205         task->state = ISCSI_TASK_PENDING;
1206         task->conn = conn;
1207         task->sc = sc;
1208         INIT_LIST_HEAD(&task->running);
1209         list_add_tail(&task->running, &conn->xmitqueue);
1210
1211         if (session->tt->caps & CAP_DATA_PATH_OFFLOAD) {
1212                 if (iscsi_prep_scsi_cmd_pdu(task)) {
1213                         sc->result = DID_ABORT << 16;
1214                         sc->scsi_done = NULL;
1215                         iscsi_complete_command(task);
1216                         goto fault;
1217                 }
1218                 if (session->tt->xmit_task(task)) {
1219                         sc->scsi_done = NULL;
1220                         iscsi_complete_command(task);
1221                         reason = FAILURE_SESSION_NOT_READY;
1222                         goto reject;
1223                 }
1224         } else
1225                 scsi_queue_work(session->host, &conn->xmitwork);
1226
1227         session->queued_cmdsn++;
1228         spin_unlock(&session->lock);
1229         spin_lock(host->host_lock);
1230         return 0;
1231
1232 reject:
1233         spin_unlock(&session->lock);
1234         debug_scsi("cmd 0x%x rejected (%d)\n", sc->cmnd[0], reason);
1235         spin_lock(host->host_lock);
1236         return SCSI_MLQUEUE_HOST_BUSY;
1237
1238 fault:
1239         spin_unlock(&session->lock);
1240         debug_scsi("iscsi: cmd 0x%x is not queued (%d)\n", sc->cmnd[0], reason);
1241         if (!scsi_bidi_cmnd(sc))
1242                 scsi_set_resid(sc, scsi_bufflen(sc));
1243         else {
1244                 scsi_out(sc)->resid = scsi_out(sc)->length;
1245                 scsi_in(sc)->resid = scsi_in(sc)->length;
1246         }
1247         done(sc);
1248         spin_lock(host->host_lock);
1249         return 0;
1250 }
1251 EXPORT_SYMBOL_GPL(iscsi_queuecommand);
1252
1253 int iscsi_change_queue_depth(struct scsi_device *sdev, int depth)
1254 {
1255         if (depth > ISCSI_MAX_CMD_PER_LUN)
1256                 depth = ISCSI_MAX_CMD_PER_LUN;
1257         scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
1258         return sdev->queue_depth;
1259 }
1260 EXPORT_SYMBOL_GPL(iscsi_change_queue_depth);
1261
1262 void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
1263 {
1264         struct iscsi_session *session = cls_session->dd_data;
1265
1266         spin_lock_bh(&session->lock);
1267         if (session->state != ISCSI_STATE_LOGGED_IN) {
1268                 session->state = ISCSI_STATE_RECOVERY_FAILED;
1269                 if (session->leadconn)
1270                         wake_up(&session->leadconn->ehwait);
1271         }
1272         spin_unlock_bh(&session->lock);
1273 }
1274 EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
1275
1276 int iscsi_eh_host_reset(struct scsi_cmnd *sc)
1277 {
1278         struct iscsi_cls_session *cls_session;
1279         struct iscsi_session *session;
1280         struct iscsi_conn *conn;
1281
1282         cls_session = starget_to_session(scsi_target(sc->device));
1283         session = cls_session->dd_data;
1284         conn = session->leadconn;
1285
1286         mutex_lock(&session->eh_mutex);
1287         spin_lock_bh(&session->lock);
1288         if (session->state == ISCSI_STATE_TERMINATE) {
1289 failed:
1290                 debug_scsi("failing host reset: session terminated "
1291                            "[CID %d age %d]\n", conn->id, session->age);
1292                 spin_unlock_bh(&session->lock);
1293                 mutex_unlock(&session->eh_mutex);
1294                 return FAILED;
1295         }
1296
1297         spin_unlock_bh(&session->lock);
1298         mutex_unlock(&session->eh_mutex);
1299         /*
1300          * we drop the lock here but the leadconn cannot be destoyed while
1301          * we are in the scsi eh
1302          */
1303         iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1304
1305         debug_scsi("iscsi_eh_host_reset wait for relogin\n");
1306         wait_event_interruptible(conn->ehwait,
1307                                  session->state == ISCSI_STATE_TERMINATE ||
1308                                  session->state == ISCSI_STATE_LOGGED_IN ||
1309                                  session->state == ISCSI_STATE_RECOVERY_FAILED);
1310         if (signal_pending(current))
1311                 flush_signals(current);
1312
1313         mutex_lock(&session->eh_mutex);
1314         spin_lock_bh(&session->lock);
1315         if (session->state == ISCSI_STATE_LOGGED_IN)
1316                 iscsi_session_printk(KERN_INFO, session,
1317                                      "host reset succeeded\n");
1318         else
1319                 goto failed;
1320         spin_unlock_bh(&session->lock);
1321         mutex_unlock(&session->eh_mutex);
1322         return SUCCESS;
1323 }
1324 EXPORT_SYMBOL_GPL(iscsi_eh_host_reset);
1325
1326 static void iscsi_tmf_timedout(unsigned long data)
1327 {
1328         struct iscsi_conn *conn = (struct iscsi_conn *)data;
1329         struct iscsi_session *session = conn->session;
1330
1331         spin_lock(&session->lock);
1332         if (conn->tmf_state == TMF_QUEUED) {
1333                 conn->tmf_state = TMF_TIMEDOUT;
1334                 debug_scsi("tmf timedout\n");
1335                 /* unblock eh_abort() */
1336                 wake_up(&conn->ehwait);
1337         }
1338         spin_unlock(&session->lock);
1339 }
1340
1341 static int iscsi_exec_task_mgmt_fn(struct iscsi_conn *conn,
1342                                    struct iscsi_tm *hdr, int age,
1343                                    int timeout)
1344 {
1345         struct iscsi_session *session = conn->session;
1346         struct iscsi_task *task;
1347
1348         task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)hdr,
1349                                       NULL, 0);
1350         if (!task) {
1351                 spin_unlock_bh(&session->lock);
1352                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1353                 spin_lock_bh(&session->lock);
1354                 debug_scsi("tmf exec failure\n");
1355                 return -EPERM;
1356         }
1357         conn->tmfcmd_pdus_cnt++;
1358         conn->tmf_timer.expires = timeout * HZ + jiffies;
1359         conn->tmf_timer.function = iscsi_tmf_timedout;
1360         conn->tmf_timer.data = (unsigned long)conn;
1361         add_timer(&conn->tmf_timer);
1362         debug_scsi("tmf set timeout\n");
1363
1364         spin_unlock_bh(&session->lock);
1365         mutex_unlock(&session->eh_mutex);
1366
1367         /*
1368          * block eh thread until:
1369          *
1370          * 1) tmf response
1371          * 2) tmf timeout
1372          * 3) session is terminated or restarted or userspace has
1373          * given up on recovery
1374          */
1375         wait_event_interruptible(conn->ehwait, age != session->age ||
1376                                  session->state != ISCSI_STATE_LOGGED_IN ||
1377                                  conn->tmf_state != TMF_QUEUED);
1378         if (signal_pending(current))
1379                 flush_signals(current);
1380         del_timer_sync(&conn->tmf_timer);
1381
1382         mutex_lock(&session->eh_mutex);
1383         spin_lock_bh(&session->lock);
1384         /* if the session drops it will clean up the task */
1385         if (age != session->age ||
1386             session->state != ISCSI_STATE_LOGGED_IN)
1387                 return -ENOTCONN;
1388         return 0;
1389 }
1390
1391 /*
1392  * Fail commands. session lock held and recv side suspended and xmit
1393  * thread flushed
1394  */
1395 static void fail_all_commands(struct iscsi_conn *conn, unsigned lun,
1396                               int error)
1397 {
1398         struct iscsi_task *task, *tmp;
1399
1400         if (conn->task && (conn->task->sc->device->lun == lun || lun == -1))
1401                 conn->task = NULL;
1402
1403         /* flush pending */
1404         list_for_each_entry_safe(task, tmp, &conn->xmitqueue, running) {
1405                 if (lun == task->sc->device->lun || lun == -1) {
1406                         debug_scsi("failing pending sc %p itt 0x%x\n",
1407                                    task->sc, task->itt);
1408                         fail_command(conn, task, error << 16);
1409                 }
1410         }
1411
1412         list_for_each_entry_safe(task, tmp, &conn->requeue, running) {
1413                 if (lun == task->sc->device->lun || lun == -1) {
1414                         debug_scsi("failing requeued sc %p itt 0x%x\n",
1415                                    task->sc, task->itt);
1416                         fail_command(conn, task, error << 16);
1417                 }
1418         }
1419
1420         /* fail all other running */
1421         list_for_each_entry_safe(task, tmp, &conn->run_list, running) {
1422                 if (lun == task->sc->device->lun || lun == -1) {
1423                         debug_scsi("failing in progress sc %p itt 0x%x\n",
1424                                    task->sc, task->itt);
1425                         fail_command(conn, task, DID_BUS_BUSY << 16);
1426                 }
1427         }
1428 }
1429
1430 void iscsi_suspend_tx(struct iscsi_conn *conn)
1431 {
1432         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1433         if (!(conn->session->tt->caps & CAP_DATA_PATH_OFFLOAD))
1434                 scsi_flush_work(conn->session->host);
1435 }
1436 EXPORT_SYMBOL_GPL(iscsi_suspend_tx);
1437
1438 static void iscsi_start_tx(struct iscsi_conn *conn)
1439 {
1440         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1441         if (!(conn->session->tt->caps & CAP_DATA_PATH_OFFLOAD))
1442                 scsi_queue_work(conn->session->host, &conn->xmitwork);
1443 }
1444
1445 static enum scsi_eh_timer_return iscsi_eh_cmd_timed_out(struct scsi_cmnd *scmd)
1446 {
1447         struct iscsi_cls_session *cls_session;
1448         struct iscsi_session *session;
1449         struct iscsi_conn *conn;
1450         enum scsi_eh_timer_return rc = EH_NOT_HANDLED;
1451
1452         cls_session = starget_to_session(scsi_target(scmd->device));
1453         session = cls_session->dd_data;
1454
1455         debug_scsi("scsi cmd %p timedout\n", scmd);
1456
1457         spin_lock(&session->lock);
1458         if (session->state != ISCSI_STATE_LOGGED_IN) {
1459                 /*
1460                  * We are probably in the middle of iscsi recovery so let
1461                  * that complete and handle the error.
1462                  */
1463                 rc = EH_RESET_TIMER;
1464                 goto done;
1465         }
1466
1467         conn = session->leadconn;
1468         if (!conn) {
1469                 /* In the middle of shuting down */
1470                 rc = EH_RESET_TIMER;
1471                 goto done;
1472         }
1473
1474         if (!conn->recv_timeout && !conn->ping_timeout)
1475                 goto done;
1476         /*
1477          * if the ping timedout then we are in the middle of cleaning up
1478          * and can let the iscsi eh handle it
1479          */
1480         if (time_before_eq(conn->last_recv + (conn->recv_timeout * HZ) +
1481                             (conn->ping_timeout * HZ), jiffies))
1482                 rc = EH_RESET_TIMER;
1483         /*
1484          * if we are about to check the transport then give the command
1485          * more time
1486          */
1487         if (time_before_eq(conn->last_recv + (conn->recv_timeout * HZ),
1488                            jiffies))
1489                 rc = EH_RESET_TIMER;
1490         /* if in the middle of checking the transport then give us more time */
1491         if (conn->ping_task)
1492                 rc = EH_RESET_TIMER;
1493 done:
1494         spin_unlock(&session->lock);
1495         debug_scsi("return %s\n", rc == EH_RESET_TIMER ? "timer reset" : "nh");
1496         return rc;
1497 }
1498
1499 static void iscsi_check_transport_timeouts(unsigned long data)
1500 {
1501         struct iscsi_conn *conn = (struct iscsi_conn *)data;
1502         struct iscsi_session *session = conn->session;
1503         unsigned long recv_timeout, next_timeout = 0, last_recv;
1504
1505         spin_lock(&session->lock);
1506         if (session->state != ISCSI_STATE_LOGGED_IN)
1507                 goto done;
1508
1509         recv_timeout = conn->recv_timeout;
1510         if (!recv_timeout)
1511                 goto done;
1512
1513         recv_timeout *= HZ;
1514         last_recv = conn->last_recv;
1515         if (conn->ping_task &&
1516             time_before_eq(conn->last_ping + (conn->ping_timeout * HZ),
1517                            jiffies)) {
1518                 iscsi_conn_printk(KERN_ERR, conn, "ping timeout of %d secs "
1519                                   "expired, last rx %lu, last ping %lu, "
1520                                   "now %lu\n", conn->ping_timeout, last_recv,
1521                                   conn->last_ping, jiffies);
1522                 spin_unlock(&session->lock);
1523                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1524                 return;
1525         }
1526
1527         if (time_before_eq(last_recv + recv_timeout, jiffies)) {
1528                 /* send a ping to try to provoke some traffic */
1529                 debug_scsi("Sending nopout as ping on conn %p\n", conn);
1530                 iscsi_send_nopout(conn, NULL);
1531                 next_timeout = conn->last_ping + (conn->ping_timeout * HZ);
1532         } else
1533                 next_timeout = last_recv + recv_timeout;
1534
1535         debug_scsi("Setting next tmo %lu\n", next_timeout);
1536         mod_timer(&conn->transport_timer, next_timeout);
1537 done:
1538         spin_unlock(&session->lock);
1539 }
1540
1541 static void iscsi_prep_abort_task_pdu(struct iscsi_task *task,
1542                                       struct iscsi_tm *hdr)
1543 {
1544         memset(hdr, 0, sizeof(*hdr));
1545         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
1546         hdr->flags = ISCSI_TM_FUNC_ABORT_TASK & ISCSI_FLAG_TM_FUNC_MASK;
1547         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
1548         memcpy(hdr->lun, task->hdr->lun, sizeof(hdr->lun));
1549         hdr->rtt = task->hdr->itt;
1550         hdr->refcmdsn = task->hdr->cmdsn;
1551 }
1552
1553 int iscsi_eh_abort(struct scsi_cmnd *sc)
1554 {
1555         struct iscsi_cls_session *cls_session;
1556         struct iscsi_session *session;
1557         struct iscsi_conn *conn;
1558         struct iscsi_task *task;
1559         struct iscsi_tm *hdr;
1560         int rc, age;
1561
1562         cls_session = starget_to_session(scsi_target(sc->device));
1563         session = cls_session->dd_data;
1564
1565         mutex_lock(&session->eh_mutex);
1566         spin_lock_bh(&session->lock);
1567         /*
1568          * if session was ISCSI_STATE_IN_RECOVERY then we may not have
1569          * got the command.
1570          */
1571         if (!sc->SCp.ptr) {
1572                 debug_scsi("sc never reached iscsi layer or it completed.\n");
1573                 spin_unlock_bh(&session->lock);
1574                 mutex_unlock(&session->eh_mutex);
1575                 return SUCCESS;
1576         }
1577
1578         /*
1579          * If we are not logged in or we have started a new session
1580          * then let the host reset code handle this
1581          */
1582         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN ||
1583             sc->SCp.phase != session->age) {
1584                 spin_unlock_bh(&session->lock);
1585                 mutex_unlock(&session->eh_mutex);
1586                 return FAILED;
1587         }
1588
1589         conn = session->leadconn;
1590         conn->eh_abort_cnt++;
1591         age = session->age;
1592
1593         task = (struct iscsi_task *)sc->SCp.ptr;
1594         debug_scsi("aborting [sc %p itt 0x%x]\n", sc, task->itt);
1595
1596         /* task completed before time out */
1597         if (!task->sc) {
1598                 debug_scsi("sc completed while abort in progress\n");
1599                 goto success;
1600         }
1601
1602         if (task->state == ISCSI_TASK_PENDING) {
1603                 fail_command(conn, task, DID_ABORT << 16);
1604                 goto success;
1605         }
1606
1607         /* only have one tmf outstanding at a time */
1608         if (conn->tmf_state != TMF_INITIAL)
1609                 goto failed;
1610         conn->tmf_state = TMF_QUEUED;
1611
1612         hdr = &conn->tmhdr;
1613         iscsi_prep_abort_task_pdu(task, hdr);
1614
1615         if (iscsi_exec_task_mgmt_fn(conn, hdr, age, session->abort_timeout)) {
1616                 rc = FAILED;
1617                 goto failed;
1618         }
1619
1620         switch (conn->tmf_state) {
1621         case TMF_SUCCESS:
1622                 spin_unlock_bh(&session->lock);
1623                 iscsi_suspend_tx(conn);
1624                 /*
1625                  * clean up task if aborted. grab the recv lock as a writer
1626                  */
1627                 write_lock_bh(conn->recv_lock);
1628                 spin_lock(&session->lock);
1629                 fail_command(conn, task, DID_ABORT << 16);
1630                 conn->tmf_state = TMF_INITIAL;
1631                 spin_unlock(&session->lock);
1632                 write_unlock_bh(conn->recv_lock);
1633                 iscsi_start_tx(conn);
1634                 goto success_unlocked;
1635         case TMF_TIMEDOUT:
1636                 spin_unlock_bh(&session->lock);
1637                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1638                 goto failed_unlocked;
1639         case TMF_NOT_FOUND:
1640                 if (!sc->SCp.ptr) {
1641                         conn->tmf_state = TMF_INITIAL;
1642                         /* task completed before tmf abort response */
1643                         debug_scsi("sc completed while abort in progress\n");
1644                         goto success;
1645                 }
1646                 /* fall through */
1647         default:
1648                 conn->tmf_state = TMF_INITIAL;
1649                 goto failed;
1650         }
1651
1652 success:
1653         spin_unlock_bh(&session->lock);
1654 success_unlocked:
1655         debug_scsi("abort success [sc %lx itt 0x%x]\n", (long)sc, task->itt);
1656         mutex_unlock(&session->eh_mutex);
1657         return SUCCESS;
1658
1659 failed:
1660         spin_unlock_bh(&session->lock);
1661 failed_unlocked:
1662         debug_scsi("abort failed [sc %p itt 0x%x]\n", sc,
1663                     task ? task->itt : 0);
1664         mutex_unlock(&session->eh_mutex);
1665         return FAILED;
1666 }
1667 EXPORT_SYMBOL_GPL(iscsi_eh_abort);
1668
1669 static void iscsi_prep_lun_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
1670 {
1671         memset(hdr, 0, sizeof(*hdr));
1672         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
1673         hdr->flags = ISCSI_TM_FUNC_LOGICAL_UNIT_RESET & ISCSI_FLAG_TM_FUNC_MASK;
1674         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
1675         int_to_scsilun(sc->device->lun, (struct scsi_lun *)hdr->lun);
1676         hdr->rtt = RESERVED_ITT;
1677 }
1678
1679 int iscsi_eh_device_reset(struct scsi_cmnd *sc)
1680 {
1681         struct iscsi_cls_session *cls_session;
1682         struct iscsi_session *session;
1683         struct iscsi_conn *conn;
1684         struct iscsi_tm *hdr;
1685         int rc = FAILED;
1686
1687         cls_session = starget_to_session(scsi_target(sc->device));
1688         session = cls_session->dd_data;
1689
1690         debug_scsi("LU Reset [sc %p lun %u]\n", sc, sc->device->lun);
1691
1692         mutex_lock(&session->eh_mutex);
1693         spin_lock_bh(&session->lock);
1694         /*
1695          * Just check if we are not logged in. We cannot check for
1696          * the phase because the reset could come from a ioctl.
1697          */
1698         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
1699                 goto unlock;
1700         conn = session->leadconn;
1701
1702         /* only have one tmf outstanding at a time */
1703         if (conn->tmf_state != TMF_INITIAL)
1704                 goto unlock;
1705         conn->tmf_state = TMF_QUEUED;
1706
1707         hdr = &conn->tmhdr;
1708         iscsi_prep_lun_reset_pdu(sc, hdr);
1709
1710         if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
1711                                     session->lu_reset_timeout)) {
1712                 rc = FAILED;
1713                 goto unlock;
1714         }
1715
1716         switch (conn->tmf_state) {
1717         case TMF_SUCCESS:
1718                 break;
1719         case TMF_TIMEDOUT:
1720                 spin_unlock_bh(&session->lock);
1721                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1722                 goto done;
1723         default:
1724                 conn->tmf_state = TMF_INITIAL;
1725                 goto unlock;
1726         }
1727
1728         rc = SUCCESS;
1729         spin_unlock_bh(&session->lock);
1730
1731         iscsi_suspend_tx(conn);
1732         /* need to grab the recv lock then session lock */
1733         write_lock_bh(conn->recv_lock);
1734         spin_lock(&session->lock);
1735         fail_all_commands(conn, sc->device->lun, DID_ERROR);
1736         conn->tmf_state = TMF_INITIAL;
1737         spin_unlock(&session->lock);
1738         write_unlock_bh(conn->recv_lock);
1739
1740         iscsi_start_tx(conn);
1741         goto done;
1742
1743 unlock:
1744         spin_unlock_bh(&session->lock);
1745 done:
1746         debug_scsi("iscsi_eh_device_reset %s\n",
1747                   rc == SUCCESS ? "SUCCESS" : "FAILED");
1748         mutex_unlock(&session->eh_mutex);
1749         return rc;
1750 }
1751 EXPORT_SYMBOL_GPL(iscsi_eh_device_reset);
1752
1753 /*
1754  * Pre-allocate a pool of @max items of @item_size. By default, the pool
1755  * should be accessed via kfifo_{get,put} on q->queue.
1756  * Optionally, the caller can obtain the array of object pointers
1757  * by passing in a non-NULL @items pointer
1758  */
1759 int
1760 iscsi_pool_init(struct iscsi_pool *q, int max, void ***items, int item_size)
1761 {
1762         int i, num_arrays = 1;
1763
1764         memset(q, 0, sizeof(*q));
1765
1766         q->max = max;
1767
1768         /* If the user passed an items pointer, he wants a copy of
1769          * the array. */
1770         if (items)
1771                 num_arrays++;
1772         q->pool = kzalloc(num_arrays * max * sizeof(void*), GFP_KERNEL);
1773         if (q->pool == NULL)
1774                 goto enomem;
1775
1776         q->queue = kfifo_init((void*)q->pool, max * sizeof(void*),
1777                               GFP_KERNEL, NULL);
1778         if (q->queue == ERR_PTR(-ENOMEM))
1779                 goto enomem;
1780
1781         for (i = 0; i < max; i++) {
1782                 q->pool[i] = kzalloc(item_size, GFP_KERNEL);
1783                 if (q->pool[i] == NULL) {
1784                         q->max = i;
1785                         goto enomem;
1786                 }
1787                 __kfifo_put(q->queue, (void*)&q->pool[i], sizeof(void*));
1788         }
1789
1790         if (items) {
1791                 *items = q->pool + max;
1792                 memcpy(*items, q->pool, max * sizeof(void *));
1793         }
1794
1795         return 0;
1796
1797 enomem:
1798         iscsi_pool_free(q);
1799         return -ENOMEM;
1800 }
1801 EXPORT_SYMBOL_GPL(iscsi_pool_init);
1802
1803 void iscsi_pool_free(struct iscsi_pool *q)
1804 {
1805         int i;
1806
1807         for (i = 0; i < q->max; i++)
1808                 kfree(q->pool[i]);
1809         if (q->pool)
1810                 kfree(q->pool);
1811 }
1812 EXPORT_SYMBOL_GPL(iscsi_pool_free);
1813
1814 /**
1815  * iscsi_host_add - add host to system
1816  * @shost: scsi host
1817  * @pdev: parent device
1818  *
1819  * This should be called by partial offload and software iscsi drivers
1820  * to add a host to the system.
1821  */
1822 int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev)
1823 {
1824         return scsi_add_host(shost, pdev);
1825 }
1826 EXPORT_SYMBOL_GPL(iscsi_host_add);
1827
1828 /**
1829  * iscsi_host_alloc - allocate a host and driver data
1830  * @sht: scsi host template
1831  * @dd_data_size: driver host data size
1832  * @qdepth: default device queue depth
1833  *
1834  * This should be called by partial offload and software iscsi drivers.
1835  * To access the driver specific memory use the iscsi_host_priv() macro.
1836  */
1837 struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
1838                                    int dd_data_size, uint16_t qdepth)
1839 {
1840         struct Scsi_Host *shost;
1841
1842         shost = scsi_host_alloc(sht, sizeof(struct iscsi_host) + dd_data_size);
1843         if (!shost)
1844                 return NULL;
1845         shost->transportt->eh_timed_out = iscsi_eh_cmd_timed_out;
1846
1847         if (qdepth > ISCSI_MAX_CMD_PER_LUN || qdepth < 1) {
1848                 if (qdepth != 0)
1849                         printk(KERN_ERR "iscsi: invalid queue depth of %d. "
1850                                "Queue depth must be between 1 and %d.\n",
1851                                qdepth, ISCSI_MAX_CMD_PER_LUN);
1852                 qdepth = ISCSI_DEF_CMD_PER_LUN;
1853         }
1854         shost->cmd_per_lun = qdepth;
1855         return shost;
1856 }
1857 EXPORT_SYMBOL_GPL(iscsi_host_alloc);
1858
1859 /**
1860  * iscsi_host_remove - remove host and sessions
1861  * @shost: scsi host
1862  *
1863  * This will also remove any sessions attached to the host, but if userspace
1864  * is managing the session at the same time this will break. TODO: add
1865  * refcounting to the netlink iscsi interface so a rmmod or host hot unplug
1866  * does not remove the memory from under us.
1867  */
1868 void iscsi_host_remove(struct Scsi_Host *shost)
1869 {
1870         iscsi_host_for_each_session(shost, iscsi_session_teardown);
1871         scsi_remove_host(shost);
1872 }
1873 EXPORT_SYMBOL_GPL(iscsi_host_remove);
1874
1875 void iscsi_host_free(struct Scsi_Host *shost)
1876 {
1877         struct iscsi_host *ihost = shost_priv(shost);
1878
1879         kfree(ihost->netdev);
1880         kfree(ihost->hwaddress);
1881         kfree(ihost->initiatorname);
1882         scsi_host_put(shost);
1883 }
1884 EXPORT_SYMBOL_GPL(iscsi_host_free);
1885
1886 /**
1887  * iscsi_session_setup - create iscsi cls session and host and session
1888  * @iscsit: iscsi transport template
1889  * @shost: scsi host
1890  * @cmds_max: session can queue
1891  * @cmd_task_size: LLD task private data size
1892  * @initial_cmdsn: initial CmdSN
1893  *
1894  * This can be used by software iscsi_transports that allocate
1895  * a session per scsi host.
1896  */
1897 struct iscsi_cls_session *
1898 iscsi_session_setup(struct iscsi_transport *iscsit, struct Scsi_Host *shost,
1899                     uint16_t scsi_cmds_max, int cmd_task_size,
1900                     uint32_t initial_cmdsn, unsigned int id)
1901 {
1902         struct iscsi_session *session;
1903         struct iscsi_cls_session *cls_session;
1904         int cmd_i, cmds_max;
1905
1906         /*
1907          * The iscsi layer needs some tasks for nop handling and tmfs.
1908          */
1909         if (scsi_cmds_max < 1)
1910                 scsi_cmds_max = ISCSI_MGMT_CMDS_MAX;
1911         if ((scsi_cmds_max + ISCSI_MGMT_CMDS_MAX) >= ISCSI_MGMT_ITT_OFFSET) {
1912                 printk(KERN_ERR "iscsi: invalid can_queue of %d. "
1913                        "can_queue must be less than %d.\n",
1914                        scsi_cmds_max,
1915                        ISCSI_MGMT_ITT_OFFSET - ISCSI_MGMT_CMDS_MAX);
1916                 scsi_cmds_max = ISCSI_DEF_XMIT_CMDS_MAX;
1917         }
1918         cmds_max = roundup_pow_of_two(scsi_cmds_max + ISCSI_MGMT_CMDS_MAX);
1919
1920         cls_session = iscsi_alloc_session(shost, iscsit,
1921                                           sizeof(struct iscsi_session));
1922         if (!cls_session)
1923                 return NULL;
1924         session = cls_session->dd_data;
1925         session->cls_session = cls_session;
1926         session->host = shost;
1927         session->state = ISCSI_STATE_FREE;
1928         session->fast_abort = 1;
1929         session->lu_reset_timeout = 15;
1930         session->abort_timeout = 10;
1931         session->scsi_cmds_max = scsi_cmds_max;
1932         session->cmds_max = cmds_max;
1933         session->queued_cmdsn = session->cmdsn = initial_cmdsn;
1934         session->exp_cmdsn = initial_cmdsn + 1;
1935         session->max_cmdsn = initial_cmdsn + 1;
1936         session->max_r2t = 1;
1937         session->tt = iscsit;
1938         mutex_init(&session->eh_mutex);
1939         spin_lock_init(&session->lock);
1940
1941         /* initialize SCSI PDU commands pool */
1942         if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
1943                             (void***)&session->cmds,
1944                             cmd_task_size + sizeof(struct iscsi_task)))
1945                 goto cmdpool_alloc_fail;
1946
1947         /* pre-format cmds pool with ITT */
1948         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
1949                 struct iscsi_task *task = session->cmds[cmd_i];
1950
1951                 if (cmd_task_size)
1952                         task->dd_data = &task[1];
1953                 task->itt = cmd_i;
1954                 INIT_LIST_HEAD(&task->running);
1955         }
1956
1957         if (!try_module_get(iscsit->owner))
1958                 goto module_get_fail;
1959
1960         if (iscsi_add_session(cls_session, id))
1961                 goto cls_session_fail;
1962         return cls_session;
1963
1964 cls_session_fail:
1965         module_put(iscsit->owner);
1966 module_get_fail:
1967         iscsi_pool_free(&session->cmdpool);
1968 cmdpool_alloc_fail:
1969         iscsi_free_session(cls_session);
1970         return NULL;
1971 }
1972 EXPORT_SYMBOL_GPL(iscsi_session_setup);
1973
1974 /**
1975  * iscsi_session_teardown - destroy session, host, and cls_session
1976  * @cls_session: iscsi session
1977  *
1978  * The driver must have called iscsi_remove_session before
1979  * calling this.
1980  */
1981 void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
1982 {
1983         struct iscsi_session *session = cls_session->dd_data;
1984         struct module *owner = cls_session->transport->owner;
1985
1986         iscsi_pool_free(&session->cmdpool);
1987
1988         kfree(session->password);
1989         kfree(session->password_in);
1990         kfree(session->username);
1991         kfree(session->username_in);
1992         kfree(session->targetname);
1993
1994         iscsi_destroy_session(cls_session);
1995         module_put(owner);
1996 }
1997 EXPORT_SYMBOL_GPL(iscsi_session_teardown);
1998
1999 /**
2000  * iscsi_conn_setup - create iscsi_cls_conn and iscsi_conn
2001  * @cls_session: iscsi_cls_session
2002  * @dd_size: private driver data size
2003  * @conn_idx: cid
2004  */
2005 struct iscsi_cls_conn *
2006 iscsi_conn_setup(struct iscsi_cls_session *cls_session, int dd_size,
2007                  uint32_t conn_idx)
2008 {
2009         struct iscsi_session *session = cls_session->dd_data;
2010         struct iscsi_conn *conn;
2011         struct iscsi_cls_conn *cls_conn;
2012         char *data;
2013
2014         cls_conn = iscsi_create_conn(cls_session, sizeof(*conn) + dd_size,
2015                                      conn_idx);
2016         if (!cls_conn)
2017                 return NULL;
2018         conn = cls_conn->dd_data;
2019         memset(conn, 0, sizeof(*conn) + dd_size);
2020
2021         conn->dd_data = cls_conn->dd_data + sizeof(*conn);
2022         conn->session = session;
2023         conn->cls_conn = cls_conn;
2024         conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
2025         conn->id = conn_idx;
2026         conn->exp_statsn = 0;
2027         conn->tmf_state = TMF_INITIAL;
2028
2029         init_timer(&conn->transport_timer);
2030         conn->transport_timer.data = (unsigned long)conn;
2031         conn->transport_timer.function = iscsi_check_transport_timeouts;
2032
2033         INIT_LIST_HEAD(&conn->run_list);
2034         INIT_LIST_HEAD(&conn->mgmt_run_list);
2035         INIT_LIST_HEAD(&conn->mgmtqueue);
2036         INIT_LIST_HEAD(&conn->xmitqueue);
2037         INIT_LIST_HEAD(&conn->requeue);
2038         INIT_WORK(&conn->xmitwork, iscsi_xmitworker);
2039
2040         /* allocate login_task used for the login/text sequences */
2041         spin_lock_bh(&session->lock);
2042         if (!__kfifo_get(session->cmdpool.queue,
2043                          (void*)&conn->login_task,
2044                          sizeof(void*))) {
2045                 spin_unlock_bh(&session->lock);
2046                 goto login_task_alloc_fail;
2047         }
2048         spin_unlock_bh(&session->lock);
2049
2050         data = kmalloc(ISCSI_DEF_MAX_RECV_SEG_LEN, GFP_KERNEL);
2051         if (!data)
2052                 goto login_task_data_alloc_fail;
2053         conn->login_task->data = conn->data = data;
2054
2055         init_timer(&conn->tmf_timer);
2056         init_waitqueue_head(&conn->ehwait);
2057
2058         return cls_conn;
2059
2060 login_task_data_alloc_fail:
2061         __kfifo_put(session->cmdpool.queue, (void*)&conn->login_task,
2062                     sizeof(void*));
2063 login_task_alloc_fail:
2064         iscsi_destroy_conn(cls_conn);
2065         return NULL;
2066 }
2067 EXPORT_SYMBOL_GPL(iscsi_conn_setup);
2068
2069 /**
2070  * iscsi_conn_teardown - teardown iscsi connection
2071  * cls_conn: iscsi class connection
2072  *
2073  * TODO: we may need to make this into a two step process
2074  * like scsi-mls remove + put host
2075  */
2076 void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
2077 {
2078         struct iscsi_conn *conn = cls_conn->dd_data;
2079         struct iscsi_session *session = conn->session;
2080         unsigned long flags;
2081
2082         del_timer_sync(&conn->transport_timer);
2083
2084         spin_lock_bh(&session->lock);
2085         conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
2086         if (session->leadconn == conn) {
2087                 /*
2088                  * leading connection? then give up on recovery.
2089                  */
2090                 session->state = ISCSI_STATE_TERMINATE;
2091                 wake_up(&conn->ehwait);
2092         }
2093         spin_unlock_bh(&session->lock);
2094
2095         /*
2096          * Block until all in-progress commands for this connection
2097          * time out or fail.
2098          */
2099         for (;;) {
2100                 spin_lock_irqsave(session->host->host_lock, flags);
2101                 if (!session->host->host_busy) { /* OK for ERL == 0 */
2102                         spin_unlock_irqrestore(session->host->host_lock, flags);
2103                         break;
2104                 }
2105                 spin_unlock_irqrestore(session->host->host_lock, flags);
2106                 msleep_interruptible(500);
2107                 iscsi_conn_printk(KERN_INFO, conn, "iscsi conn_destroy(): "
2108                                   "host_busy %d host_failed %d\n",
2109                                   session->host->host_busy,
2110                                   session->host->host_failed);
2111                 /*
2112                  * force eh_abort() to unblock
2113                  */
2114                 wake_up(&conn->ehwait);
2115         }
2116
2117         /* flush queued up work because we free the connection below */
2118         iscsi_suspend_tx(conn);
2119
2120         spin_lock_bh(&session->lock);
2121         kfree(conn->data);
2122         kfree(conn->persistent_address);
2123         __kfifo_put(session->cmdpool.queue, (void*)&conn->login_task,
2124                     sizeof(void*));
2125         if (session->leadconn == conn)
2126                 session->leadconn = NULL;
2127         spin_unlock_bh(&session->lock);
2128
2129         iscsi_destroy_conn(cls_conn);
2130 }
2131 EXPORT_SYMBOL_GPL(iscsi_conn_teardown);
2132
2133 int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
2134 {
2135         struct iscsi_conn *conn = cls_conn->dd_data;
2136         struct iscsi_session *session = conn->session;
2137
2138         if (!session) {
2139                 iscsi_conn_printk(KERN_ERR, conn,
2140                                   "can't start unbound connection\n");
2141                 return -EPERM;
2142         }
2143
2144         if ((session->imm_data_en || !session->initial_r2t_en) &&
2145              session->first_burst > session->max_burst) {
2146                 iscsi_conn_printk(KERN_INFO, conn, "invalid burst lengths: "
2147                                   "first_burst %d max_burst %d\n",
2148                                   session->first_burst, session->max_burst);
2149                 return -EINVAL;
2150         }
2151
2152         if (conn->ping_timeout && !conn->recv_timeout) {
2153                 iscsi_conn_printk(KERN_ERR, conn, "invalid recv timeout of "
2154                                   "zero. Using 5 seconds\n.");
2155                 conn->recv_timeout = 5;
2156         }
2157
2158         if (conn->recv_timeout && !conn->ping_timeout) {
2159                 iscsi_conn_printk(KERN_ERR, conn, "invalid ping timeout of "
2160                                   "zero. Using 5 seconds.\n");
2161                 conn->ping_timeout = 5;
2162         }
2163
2164         spin_lock_bh(&session->lock);
2165         conn->c_stage = ISCSI_CONN_STARTED;
2166         session->state = ISCSI_STATE_LOGGED_IN;
2167         session->queued_cmdsn = session->cmdsn;
2168
2169         conn->last_recv = jiffies;
2170         conn->last_ping = jiffies;
2171         if (conn->recv_timeout && conn->ping_timeout)
2172                 mod_timer(&conn->transport_timer,
2173                           jiffies + (conn->recv_timeout * HZ));
2174
2175         switch(conn->stop_stage) {
2176         case STOP_CONN_RECOVER:
2177                 /*
2178                  * unblock eh_abort() if it is blocked. re-try all
2179                  * commands after successful recovery
2180                  */
2181                 conn->stop_stage = 0;
2182                 conn->tmf_state = TMF_INITIAL;
2183                 session->age++;
2184                 if (session->age == 16)
2185                         session->age = 0;
2186                 break;
2187         case STOP_CONN_TERM:
2188                 conn->stop_stage = 0;
2189                 break;
2190         default:
2191                 break;
2192         }
2193         spin_unlock_bh(&session->lock);
2194
2195         iscsi_unblock_session(session->cls_session);
2196         wake_up(&conn->ehwait);
2197         return 0;
2198 }
2199 EXPORT_SYMBOL_GPL(iscsi_conn_start);
2200
2201 static void
2202 flush_control_queues(struct iscsi_session *session, struct iscsi_conn *conn)
2203 {
2204         struct iscsi_task *task, *tmp;
2205
2206         /* handle pending */
2207         list_for_each_entry_safe(task, tmp, &conn->mgmtqueue, running) {
2208                 debug_scsi("flushing pending mgmt task itt 0x%x\n", task->itt);
2209                 /* release ref from prep task */
2210                 __iscsi_put_task(task);
2211         }
2212
2213         /* handle running */
2214         list_for_each_entry_safe(task, tmp, &conn->mgmt_run_list, running) {
2215                 debug_scsi("flushing running mgmt task itt 0x%x\n", task->itt);
2216                 /* release ref from prep task */
2217                 __iscsi_put_task(task);
2218         }
2219
2220         conn->task = NULL;
2221 }
2222
2223 static void iscsi_start_session_recovery(struct iscsi_session *session,
2224                                          struct iscsi_conn *conn, int flag)
2225 {
2226         int old_stop_stage;
2227
2228         del_timer_sync(&conn->transport_timer);
2229
2230         mutex_lock(&session->eh_mutex);
2231         spin_lock_bh(&session->lock);
2232         if (conn->stop_stage == STOP_CONN_TERM) {
2233                 spin_unlock_bh(&session->lock);
2234                 mutex_unlock(&session->eh_mutex);
2235                 return;
2236         }
2237
2238         /*
2239          * The LLD either freed/unset the lock on us, or userspace called
2240          * stop but did not create a proper connection (connection was never
2241          * bound or it was unbound then stop was called).
2242          */
2243         if (!conn->recv_lock) {
2244                 spin_unlock_bh(&session->lock);
2245                 mutex_unlock(&session->eh_mutex);
2246                 return;
2247         }
2248
2249         /*
2250          * When this is called for the in_login state, we only want to clean
2251          * up the login task and connection. We do not need to block and set
2252          * the recovery state again
2253          */
2254         if (flag == STOP_CONN_TERM)
2255                 session->state = ISCSI_STATE_TERMINATE;
2256         else if (conn->stop_stage != STOP_CONN_RECOVER)
2257                 session->state = ISCSI_STATE_IN_RECOVERY;
2258
2259         old_stop_stage = conn->stop_stage;
2260         conn->stop_stage = flag;
2261         conn->c_stage = ISCSI_CONN_STOPPED;
2262         spin_unlock_bh(&session->lock);
2263
2264         iscsi_suspend_tx(conn);
2265
2266         write_lock_bh(conn->recv_lock);
2267         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
2268         write_unlock_bh(conn->recv_lock);
2269
2270         /*
2271          * for connection level recovery we should not calculate
2272          * header digest. conn->hdr_size used for optimization
2273          * in hdr_extract() and will be re-negotiated at
2274          * set_param() time.
2275          */
2276         if (flag == STOP_CONN_RECOVER) {
2277                 conn->hdrdgst_en = 0;
2278                 conn->datadgst_en = 0;
2279                 if (session->state == ISCSI_STATE_IN_RECOVERY &&
2280                     old_stop_stage != STOP_CONN_RECOVER) {
2281                         debug_scsi("blocking session\n");
2282                         iscsi_block_session(session->cls_session);
2283                 }
2284         }
2285
2286         /*
2287          * flush queues.
2288          */
2289         spin_lock_bh(&session->lock);
2290         fail_all_commands(conn, -1,
2291                         STOP_CONN_RECOVER ? DID_BUS_BUSY : DID_ERROR);
2292         flush_control_queues(session, conn);
2293         spin_unlock_bh(&session->lock);
2294         mutex_unlock(&session->eh_mutex);
2295 }
2296
2297 void iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
2298 {
2299         struct iscsi_conn *conn = cls_conn->dd_data;
2300         struct iscsi_session *session = conn->session;
2301
2302         switch (flag) {
2303         case STOP_CONN_RECOVER:
2304         case STOP_CONN_TERM:
2305                 iscsi_start_session_recovery(session, conn, flag);
2306                 break;
2307         default:
2308                 iscsi_conn_printk(KERN_ERR, conn,
2309                                   "invalid stop flag %d\n", flag);
2310         }
2311 }
2312 EXPORT_SYMBOL_GPL(iscsi_conn_stop);
2313
2314 int iscsi_conn_bind(struct iscsi_cls_session *cls_session,
2315                     struct iscsi_cls_conn *cls_conn, int is_leading)
2316 {
2317         struct iscsi_session *session = cls_session->dd_data;
2318         struct iscsi_conn *conn = cls_conn->dd_data;
2319
2320         spin_lock_bh(&session->lock);
2321         if (is_leading)
2322                 session->leadconn = conn;
2323         spin_unlock_bh(&session->lock);
2324
2325         /*
2326          * Unblock xmitworker(), Login Phase will pass through.
2327          */
2328         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
2329         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
2330         return 0;
2331 }
2332 EXPORT_SYMBOL_GPL(iscsi_conn_bind);
2333
2334
2335 int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
2336                     enum iscsi_param param, char *buf, int buflen)
2337 {
2338         struct iscsi_conn *conn = cls_conn->dd_data;
2339         struct iscsi_session *session = conn->session;
2340         uint32_t value;
2341
2342         switch(param) {
2343         case ISCSI_PARAM_FAST_ABORT:
2344                 sscanf(buf, "%d", &session->fast_abort);
2345                 break;
2346         case ISCSI_PARAM_ABORT_TMO:
2347                 sscanf(buf, "%d", &session->abort_timeout);
2348                 break;
2349         case ISCSI_PARAM_LU_RESET_TMO:
2350                 sscanf(buf, "%d", &session->lu_reset_timeout);
2351                 break;
2352         case ISCSI_PARAM_PING_TMO:
2353                 sscanf(buf, "%d", &conn->ping_timeout);
2354                 break;
2355         case ISCSI_PARAM_RECV_TMO:
2356                 sscanf(buf, "%d", &conn->recv_timeout);
2357                 break;
2358         case ISCSI_PARAM_MAX_RECV_DLENGTH:
2359                 sscanf(buf, "%d", &conn->max_recv_dlength);
2360                 break;
2361         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
2362                 sscanf(buf, "%d", &conn->max_xmit_dlength);
2363                 break;
2364         case ISCSI_PARAM_HDRDGST_EN:
2365                 sscanf(buf, "%d", &conn->hdrdgst_en);
2366                 break;
2367         case ISCSI_PARAM_DATADGST_EN:
2368                 sscanf(buf, "%d", &conn->datadgst_en);
2369                 break;
2370         case ISCSI_PARAM_INITIAL_R2T_EN:
2371                 sscanf(buf, "%d", &session->initial_r2t_en);
2372                 break;
2373         case ISCSI_PARAM_MAX_R2T:
2374                 sscanf(buf, "%d", &session->max_r2t);
2375                 break;
2376         case ISCSI_PARAM_IMM_DATA_EN:
2377                 sscanf(buf, "%d", &session->imm_data_en);
2378                 break;
2379         case ISCSI_PARAM_FIRST_BURST:
2380                 sscanf(buf, "%d", &session->first_burst);
2381                 break;
2382         case ISCSI_PARAM_MAX_BURST:
2383                 sscanf(buf, "%d", &session->max_burst);
2384                 break;
2385         case ISCSI_PARAM_PDU_INORDER_EN:
2386                 sscanf(buf, "%d", &session->pdu_inorder_en);
2387                 break;
2388         case ISCSI_PARAM_DATASEQ_INORDER_EN:
2389                 sscanf(buf, "%d", &session->dataseq_inorder_en);
2390                 break;
2391         case ISCSI_PARAM_ERL:
2392                 sscanf(buf, "%d", &session->erl);
2393                 break;
2394         case ISCSI_PARAM_IFMARKER_EN:
2395                 sscanf(buf, "%d", &value);
2396                 BUG_ON(value);
2397                 break;
2398         case ISCSI_PARAM_OFMARKER_EN:
2399                 sscanf(buf, "%d", &value);
2400                 BUG_ON(value);
2401                 break;
2402         case ISCSI_PARAM_EXP_STATSN:
2403                 sscanf(buf, "%u", &conn->exp_statsn);
2404                 break;
2405         case ISCSI_PARAM_USERNAME:
2406                 kfree(session->username);
2407                 session->username = kstrdup(buf, GFP_KERNEL);
2408                 if (!session->username)
2409                         return -ENOMEM;
2410                 break;
2411         case ISCSI_PARAM_USERNAME_IN:
2412                 kfree(session->username_in);
2413                 session->username_in = kstrdup(buf, GFP_KERNEL);
2414                 if (!session->username_in)
2415                         return -ENOMEM;
2416                 break;
2417         case ISCSI_PARAM_PASSWORD:
2418                 kfree(session->password);
2419                 session->password = kstrdup(buf, GFP_KERNEL);
2420                 if (!session->password)
2421                         return -ENOMEM;
2422                 break;
2423         case ISCSI_PARAM_PASSWORD_IN:
2424                 kfree(session->password_in);
2425                 session->password_in = kstrdup(buf, GFP_KERNEL);
2426                 if (!session->password_in)
2427                         return -ENOMEM;
2428                 break;
2429         case ISCSI_PARAM_TARGET_NAME:
2430                 /* this should not change between logins */
2431                 if (session->targetname)
2432                         break;
2433
2434                 session->targetname = kstrdup(buf, GFP_KERNEL);
2435                 if (!session->targetname)
2436                         return -ENOMEM;
2437                 break;
2438         case ISCSI_PARAM_TPGT:
2439                 sscanf(buf, "%d", &session->tpgt);
2440                 break;
2441         case ISCSI_PARAM_PERSISTENT_PORT:
2442                 sscanf(buf, "%d", &conn->persistent_port);
2443                 break;
2444         case ISCSI_PARAM_PERSISTENT_ADDRESS:
2445                 /*
2446                  * this is the address returned in discovery so it should
2447                  * not change between logins.
2448                  */
2449                 if (conn->persistent_address)
2450                         break;
2451
2452                 conn->persistent_address = kstrdup(buf, GFP_KERNEL);
2453                 if (!conn->persistent_address)
2454                         return -ENOMEM;
2455                 break;
2456         default:
2457                 return -ENOSYS;
2458         }
2459
2460         return 0;
2461 }
2462 EXPORT_SYMBOL_GPL(iscsi_set_param);
2463
2464 int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
2465                             enum iscsi_param param, char *buf)
2466 {
2467         struct iscsi_session *session = cls_session->dd_data;
2468         int len;
2469
2470         switch(param) {
2471         case ISCSI_PARAM_FAST_ABORT:
2472                 len = sprintf(buf, "%d\n", session->fast_abort);
2473                 break;
2474         case ISCSI_PARAM_ABORT_TMO:
2475                 len = sprintf(buf, "%d\n", session->abort_timeout);
2476                 break;
2477         case ISCSI_PARAM_LU_RESET_TMO:
2478                 len = sprintf(buf, "%d\n", session->lu_reset_timeout);
2479                 break;
2480         case ISCSI_PARAM_INITIAL_R2T_EN:
2481                 len = sprintf(buf, "%d\n", session->initial_r2t_en);
2482                 break;
2483         case ISCSI_PARAM_MAX_R2T:
2484                 len = sprintf(buf, "%hu\n", session->max_r2t);
2485                 break;
2486         case ISCSI_PARAM_IMM_DATA_EN:
2487                 len = sprintf(buf, "%d\n", session->imm_data_en);
2488                 break;
2489         case ISCSI_PARAM_FIRST_BURST:
2490                 len = sprintf(buf, "%u\n", session->first_burst);
2491                 break;
2492         case ISCSI_PARAM_MAX_BURST:
2493                 len = sprintf(buf, "%u\n", session->max_burst);
2494                 break;
2495         case ISCSI_PARAM_PDU_INORDER_EN:
2496                 len = sprintf(buf, "%d\n", session->pdu_inorder_en);
2497                 break;
2498         case ISCSI_PARAM_DATASEQ_INORDER_EN:
2499                 len = sprintf(buf, "%d\n", session->dataseq_inorder_en);
2500                 break;
2501         case ISCSI_PARAM_ERL:
2502                 len = sprintf(buf, "%d\n", session->erl);
2503                 break;
2504         case ISCSI_PARAM_TARGET_NAME:
2505                 len = sprintf(buf, "%s\n", session->targetname);
2506                 break;
2507         case ISCSI_PARAM_TPGT:
2508                 len = sprintf(buf, "%d\n", session->tpgt);
2509                 break;
2510         case ISCSI_PARAM_USERNAME:
2511                 len = sprintf(buf, "%s\n", session->username);
2512                 break;
2513         case ISCSI_PARAM_USERNAME_IN:
2514                 len = sprintf(buf, "%s\n", session->username_in);
2515                 break;
2516         case ISCSI_PARAM_PASSWORD:
2517                 len = sprintf(buf, "%s\n", session->password);
2518                 break;
2519         case ISCSI_PARAM_PASSWORD_IN:
2520                 len = sprintf(buf, "%s\n", session->password_in);
2521                 break;
2522         default:
2523                 return -ENOSYS;
2524         }
2525
2526         return len;
2527 }
2528 EXPORT_SYMBOL_GPL(iscsi_session_get_param);
2529
2530 int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
2531                          enum iscsi_param param, char *buf)
2532 {
2533         struct iscsi_conn *conn = cls_conn->dd_data;
2534         int len;
2535
2536         switch(param) {
2537         case ISCSI_PARAM_PING_TMO:
2538                 len = sprintf(buf, "%u\n", conn->ping_timeout);
2539                 break;
2540         case ISCSI_PARAM_RECV_TMO:
2541                 len = sprintf(buf, "%u\n", conn->recv_timeout);
2542                 break;
2543         case ISCSI_PARAM_MAX_RECV_DLENGTH:
2544                 len = sprintf(buf, "%u\n", conn->max_recv_dlength);
2545                 break;
2546         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
2547                 len = sprintf(buf, "%u\n", conn->max_xmit_dlength);
2548                 break;
2549         case ISCSI_PARAM_HDRDGST_EN:
2550                 len = sprintf(buf, "%d\n", conn->hdrdgst_en);
2551                 break;
2552         case ISCSI_PARAM_DATADGST_EN:
2553                 len = sprintf(buf, "%d\n", conn->datadgst_en);
2554                 break;
2555         case ISCSI_PARAM_IFMARKER_EN:
2556                 len = sprintf(buf, "%d\n", conn->ifmarker_en);
2557                 break;
2558         case ISCSI_PARAM_OFMARKER_EN:
2559                 len = sprintf(buf, "%d\n", conn->ofmarker_en);
2560                 break;
2561         case ISCSI_PARAM_EXP_STATSN:
2562                 len = sprintf(buf, "%u\n", conn->exp_statsn);
2563                 break;
2564         case ISCSI_PARAM_PERSISTENT_PORT:
2565                 len = sprintf(buf, "%d\n", conn->persistent_port);
2566                 break;
2567         case ISCSI_PARAM_PERSISTENT_ADDRESS:
2568                 len = sprintf(buf, "%s\n", conn->persistent_address);
2569                 break;
2570         default:
2571                 return -ENOSYS;
2572         }
2573
2574         return len;
2575 }
2576 EXPORT_SYMBOL_GPL(iscsi_conn_get_param);
2577
2578 int iscsi_host_get_param(struct Scsi_Host *shost, enum iscsi_host_param param,
2579                          char *buf)
2580 {
2581         struct iscsi_host *ihost = shost_priv(shost);
2582         int len;
2583
2584         switch (param) {
2585         case ISCSI_HOST_PARAM_NETDEV_NAME:
2586                 if (!ihost->netdev)
2587                         len = sprintf(buf, "%s\n", "default");
2588                 else
2589                         len = sprintf(buf, "%s\n", ihost->netdev);
2590                 break;
2591         case ISCSI_HOST_PARAM_HWADDRESS:
2592                 if (!ihost->hwaddress)
2593                         len = sprintf(buf, "%s\n", "default");
2594                 else
2595                         len = sprintf(buf, "%s\n", ihost->hwaddress);
2596                 break;
2597         case ISCSI_HOST_PARAM_INITIATOR_NAME:
2598                 if (!ihost->initiatorname)
2599                         len = sprintf(buf, "%s\n", "unknown");
2600                 else
2601                         len = sprintf(buf, "%s\n", ihost->initiatorname);
2602                 break;
2603         case ISCSI_HOST_PARAM_IPADDRESS:
2604                 if (!strlen(ihost->local_address))
2605                         len = sprintf(buf, "%s\n", "unknown");
2606                 else
2607                         len = sprintf(buf, "%s\n",
2608                                       ihost->local_address);
2609         default:
2610                 return -ENOSYS;
2611         }
2612
2613         return len;
2614 }
2615 EXPORT_SYMBOL_GPL(iscsi_host_get_param);
2616
2617 int iscsi_host_set_param(struct Scsi_Host *shost, enum iscsi_host_param param,
2618                          char *buf, int buflen)
2619 {
2620         struct iscsi_host *ihost = shost_priv(shost);
2621
2622         switch (param) {
2623         case ISCSI_HOST_PARAM_NETDEV_NAME:
2624                 if (!ihost->netdev)
2625                         ihost->netdev = kstrdup(buf, GFP_KERNEL);
2626                 break;
2627         case ISCSI_HOST_PARAM_HWADDRESS:
2628                 if (!ihost->hwaddress)
2629                         ihost->hwaddress = kstrdup(buf, GFP_KERNEL);
2630                 break;
2631         case ISCSI_HOST_PARAM_INITIATOR_NAME:
2632                 if (!ihost->initiatorname)
2633                         ihost->initiatorname = kstrdup(buf, GFP_KERNEL);
2634                 break;
2635         default:
2636                 return -ENOSYS;
2637         }
2638
2639         return 0;
2640 }
2641 EXPORT_SYMBOL_GPL(iscsi_host_set_param);
2642
2643 MODULE_AUTHOR("Mike Christie");
2644 MODULE_DESCRIPTION("iSCSI library functions");
2645 MODULE_LICENSE("GPL");