git.maemo.org Git - h-e-n/blob - drivers/scsi/libiscsi.c

   1 /*
   2  * iSCSI lib functions
   3  *
   4  * Copyright (C) 2006 Red Hat, Inc.  All rights reserved.
   5  * Copyright (C) 2004 - 2006 Mike Christie
   6  * Copyright (C) 2004 - 2005 Dmitry Yusupov
   7  * Copyright (C) 2004 - 2005 Alex Aizman
   8  * maintained by open-iscsi@googlegroups.com
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  23  */
  24 #include <linux/types.h>
  25 #include <linux/kfifo.h>
  26 #include <linux/delay.h>
  27 #include <linux/log2.h>
  28 #include <asm/unaligned.h>
  29 #include <net/tcp.h>
  30 #include <scsi/scsi_cmnd.h>
  31 #include <scsi/scsi_device.h>
  32 #include <scsi/scsi_eh.h>
  33 #include <scsi/scsi_tcq.h>
  34 #include <scsi/scsi_host.h>
  35 #include <scsi/scsi.h>
  36 #include <scsi/iscsi_proto.h>
  37 #include <scsi/scsi_transport.h>
  38 #include <scsi/scsi_transport_iscsi.h>
  39 #include <scsi/libiscsi.h>
  40
  41 /* Serial Number Arithmetic, 32 bits, less than, RFC1982 */
  42 #define SNA32_CHECK 2147483648UL
  43
  44 static int iscsi_sna_lt(u32 n1, u32 n2)
  45 {
  46         return n1 != n2 && ((n1 < n2 && (n2 - n1 < SNA32_CHECK)) ||
  47                             (n1 > n2 && (n2 - n1 < SNA32_CHECK)));
  48 }
  49
  50 /* Serial Number Arithmetic, 32 bits, less than, RFC1982 */
  51 static int iscsi_sna_lte(u32 n1, u32 n2)
  52 {
  53         return n1 == n2 || ((n1 < n2 && (n2 - n1 < SNA32_CHECK)) ||
  54                             (n1 > n2 && (n2 - n1 < SNA32_CHECK)));
  55 }
  56
  57 void
  58 iscsi_update_cmdsn(struct iscsi_session *session, struct iscsi_nopin *hdr)
  59 {
  60         uint32_t max_cmdsn = be32_to_cpu(hdr->max_cmdsn);
  61         uint32_t exp_cmdsn = be32_to_cpu(hdr->exp_cmdsn);
  62
  63         /*
  64          * standard specifies this check for when to update expected and
  65          * max sequence numbers
  66          */
  67         if (iscsi_sna_lt(max_cmdsn, exp_cmdsn - 1))
  68                 return;
  69
  70         if (exp_cmdsn != session->exp_cmdsn &&
  71             !iscsi_sna_lt(exp_cmdsn, session->exp_cmdsn))
  72                 session->exp_cmdsn = exp_cmdsn;
  73
  74         if (max_cmdsn != session->max_cmdsn &&
  75             !iscsi_sna_lt(max_cmdsn, session->max_cmdsn)) {
  76                 session->max_cmdsn = max_cmdsn;
  77                 /*
  78                  * if the window closed with IO queued, then kick the
  79                  * xmit thread
  80                  */
  81                 if (!list_empty(&session->leadconn->xmitqueue) ||
  82                     !list_empty(&session->leadconn->mgmtqueue)) {
  83                         if (!(session->tt->caps & CAP_DATA_PATH_OFFLOAD))
  84                                 scsi_queue_work(session->host,
  85                                                 &session->leadconn->xmitwork);
  86                 }
  87         }
  88 }
  89 EXPORT_SYMBOL_GPL(iscsi_update_cmdsn);
  90
  91 void iscsi_prep_unsolicit_data_pdu(struct iscsi_task *task,
  92                                    struct iscsi_data *hdr)
  93 {
  94         struct iscsi_conn *conn = task->conn;
  95
  96         memset(hdr, 0, sizeof(struct iscsi_data));
  97         hdr->ttt = cpu_to_be32(ISCSI_RESERVED_TAG);
  98         hdr->datasn = cpu_to_be32(task->unsol_datasn);
  99         task->unsol_datasn++;
 100         hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
 101         memcpy(hdr->lun, task->hdr->lun, sizeof(hdr->lun));
 102
 103         hdr->itt = task->hdr->itt;
 104         hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
 105         hdr->offset = cpu_to_be32(task->unsol_offset);
 106
 107         if (task->unsol_count > conn->max_xmit_dlength) {
 108                 hton24(hdr->dlength, conn->max_xmit_dlength);
 109                 task->data_count = conn->max_xmit_dlength;
 110                 task->unsol_offset += task->data_count;
 111                 hdr->flags = 0;
 112         } else {
 113                 hton24(hdr->dlength, task->unsol_count);
 114                 task->data_count = task->unsol_count;
 115                 hdr->flags = ISCSI_FLAG_CMD_FINAL;
 116         }
 117 }
 118 EXPORT_SYMBOL_GPL(iscsi_prep_unsolicit_data_pdu);
 119
 120 static int iscsi_add_hdr(struct iscsi_task *task, unsigned len)
 121 {
 122         unsigned exp_len = task->hdr_len + len;
 123
 124         if (exp_len > task->hdr_max) {
 125                 WARN_ON(1);
 126                 return -EINVAL;
 127         }
 128
 129         WARN_ON(len & (ISCSI_PAD_LEN - 1)); /* caller must pad the AHS */
 130         task->hdr_len = exp_len;
 131         return 0;
 132 }
 133
 134 /*
 135  * make an extended cdb AHS
 136  */
 137 static int iscsi_prep_ecdb_ahs(struct iscsi_task *task)
 138 {
 139         struct scsi_cmnd *cmd = task->sc;
 140         unsigned rlen, pad_len;
 141         unsigned short ahslength;
 142         struct iscsi_ecdb_ahdr *ecdb_ahdr;
 143         int rc;
 144
 145         ecdb_ahdr = iscsi_next_hdr(task);
 146         rlen = cmd->cmd_len - ISCSI_CDB_SIZE;
 147
 148         BUG_ON(rlen > sizeof(ecdb_ahdr->ecdb));
 149         ahslength = rlen + sizeof(ecdb_ahdr->reserved);
 150
 151         pad_len = iscsi_padding(rlen);
 152
 153         rc = iscsi_add_hdr(task, sizeof(ecdb_ahdr->ahslength) +
 154                            sizeof(ecdb_ahdr->ahstype) + ahslength + pad_len);
 155         if (rc)
 156                 return rc;
 157
 158         if (pad_len)
 159                 memset(&ecdb_ahdr->ecdb[rlen], 0, pad_len);
 160
 161         ecdb_ahdr->ahslength = cpu_to_be16(ahslength);
 162         ecdb_ahdr->ahstype = ISCSI_AHSTYPE_CDB;
 163         ecdb_ahdr->reserved = 0;
 164         memcpy(ecdb_ahdr->ecdb, cmd->cmnd + ISCSI_CDB_SIZE, rlen);
 165
 166         debug_scsi("iscsi_prep_ecdb_ahs: varlen_cdb_len %d "
 167                    "rlen %d pad_len %d ahs_length %d iscsi_headers_size %u\n",
 168                    cmd->cmd_len, rlen, pad_len, ahslength, task->hdr_len);
 169
 170         return 0;
 171 }
 172
 173 static int iscsi_prep_bidi_ahs(struct iscsi_task *task)
 174 {
 175         struct scsi_cmnd *sc = task->sc;
 176         struct iscsi_rlength_ahdr *rlen_ahdr;
 177         int rc;
 178
 179         rlen_ahdr = iscsi_next_hdr(task);
 180         rc = iscsi_add_hdr(task, sizeof(*rlen_ahdr));
 181         if (rc)
 182                 return rc;
 183
 184         rlen_ahdr->ahslength =
 185                 cpu_to_be16(sizeof(rlen_ahdr->read_length) +
 186                                                   sizeof(rlen_ahdr->reserved));
 187         rlen_ahdr->ahstype = ISCSI_AHSTYPE_RLENGTH;
 188         rlen_ahdr->reserved = 0;
 189         rlen_ahdr->read_length = cpu_to_be32(scsi_in(sc)->length);
 190
 191         debug_scsi("bidi-in rlen_ahdr->read_length(%d) "
 192                    "rlen_ahdr->ahslength(%d)\n",
 193                    be32_to_cpu(rlen_ahdr->read_length),
 194                    be16_to_cpu(rlen_ahdr->ahslength));
 195         return 0;
 196 }
 197
 198 /**
 199  * iscsi_prep_scsi_cmd_pdu - prep iscsi scsi cmd pdu
 200  * @task: iscsi task
 201  *
 202  * Prep basic iSCSI PDU fields for a scsi cmd pdu. The LLD should set
 203  * fields like dlength or final based on how much data it sends
 204  */
 205 static int iscsi_prep_scsi_cmd_pdu(struct iscsi_task *task)
 206 {
 207         struct iscsi_conn *conn = task->conn;
 208         struct iscsi_session *session = conn->session;
 209         struct iscsi_cmd *hdr = task->hdr;
 210         struct scsi_cmnd *sc = task->sc;
 211         unsigned hdrlength, cmd_len;
 212         int rc;
 213
 214         task->hdr_len = 0;
 215         rc = iscsi_add_hdr(task, sizeof(*hdr));
 216         if (rc)
 217                 return rc;
 218         hdr->opcode = ISCSI_OP_SCSI_CMD;
 219         hdr->flags = ISCSI_ATTR_SIMPLE;
 220         int_to_scsilun(sc->device->lun, (struct scsi_lun *)hdr->lun);
 221         hdr->itt = build_itt(task->itt, session->age);
 222         hdr->cmdsn = cpu_to_be32(session->cmdsn);
 223         session->cmdsn++;
 224         hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
 225         cmd_len = sc->cmd_len;
 226         if (cmd_len < ISCSI_CDB_SIZE)
 227                 memset(&hdr->cdb[cmd_len], 0, ISCSI_CDB_SIZE - cmd_len);
 228         else if (cmd_len > ISCSI_CDB_SIZE) {
 229                 rc = iscsi_prep_ecdb_ahs(task);
 230                 if (rc)
 231                         return rc;
 232                 cmd_len = ISCSI_CDB_SIZE;
 233         }
 234         memcpy(hdr->cdb, sc->cmnd, cmd_len);
 235
 236         task->imm_count = 0;
 237         if (scsi_bidi_cmnd(sc)) {
 238                 hdr->flags |= ISCSI_FLAG_CMD_READ;
 239                 rc = iscsi_prep_bidi_ahs(task);
 240                 if (rc)
 241                         return rc;
 242         }
 243         if (sc->sc_data_direction == DMA_TO_DEVICE) {
 244                 unsigned out_len = scsi_out(sc)->length;
 245                 hdr->data_length = cpu_to_be32(out_len);
 246                 hdr->flags |= ISCSI_FLAG_CMD_WRITE;
 247                 /*
 248                  * Write counters:
 249                  *
 250                  *      imm_count       bytes to be sent right after
 251                  *                      SCSI PDU Header
 252                  *
 253                  *      unsol_count     bytes(as Data-Out) to be sent
 254                  *                      without R2T ack right after
 255                  *                      immediate data
 256                  *
 257                  *      r2t_data_count  bytes to be sent via R2T ack's
 258                  *
 259                  *      pad_count       bytes to be sent as zero-padding
 260                  */
 261                 task->unsol_count = 0;
 262                 task->unsol_offset = 0;
 263                 task->unsol_datasn = 0;
 264
 265                 if (session->imm_data_en) {
 266                         if (out_len >= session->first_burst)
 267                                 task->imm_count = min(session->first_burst,
 268                                                         conn->max_xmit_dlength);
 269                         else
 270                                 task->imm_count = min(out_len,
 271                                                         conn->max_xmit_dlength);
 272                         hton24(hdr->dlength, task->imm_count);
 273                 } else
 274                         zero_data(hdr->dlength);
 275
 276                 if (!session->initial_r2t_en) {
 277                         task->unsol_count = min(session->first_burst, out_len)
 278                                                              - task->imm_count;
 279                         task->unsol_offset = task->imm_count;
 280                 }
 281
 282                 if (!task->unsol_count)
 283                         /* No unsolicit Data-Out's */
 284                         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
 285         } else {
 286                 hdr->flags |= ISCSI_FLAG_CMD_FINAL;
 287                 zero_data(hdr->dlength);
 288                 hdr->data_length = cpu_to_be32(scsi_in(sc)->length);
 289
 290                 if (sc->sc_data_direction == DMA_FROM_DEVICE)
 291                         hdr->flags |= ISCSI_FLAG_CMD_READ;
 292         }
 293
 294         /* calculate size of additional header segments (AHSs) */
 295         hdrlength = task->hdr_len - sizeof(*hdr);
 296
 297         WARN_ON(hdrlength & (ISCSI_PAD_LEN-1));
 298         hdrlength /= ISCSI_PAD_LEN;
 299
 300         WARN_ON(hdrlength >= 256);
 301         hdr->hlength = hdrlength & 0xFF;
 302
 303         if (conn->session->tt->init_task &&
 304             conn->session->tt->init_task(task))
 305                 return -EIO;
 306
 307         task->state = ISCSI_TASK_RUNNING;
 308         list_move_tail(&task->running, &conn->run_list);
 309
 310         conn->scsicmd_pdus_cnt++;
 311         debug_scsi("iscsi prep [%s cid %d sc %p cdb 0x%x itt 0x%x len %d "
 312                    "bidi_len %d cmdsn %d win %d]\n", scsi_bidi_cmnd(sc) ?
 313                    "bidirectional" : sc->sc_data_direction == DMA_TO_DEVICE ?
 314                    "write" : "read", conn->id, sc, sc->cmnd[0], task->itt,
 315                    scsi_bufflen(sc),
 316                    scsi_bidi_cmnd(sc) ? scsi_in(sc)->length : 0,
 317                    session->cmdsn, session->max_cmdsn - session->exp_cmdsn + 1);
 318         return 0;
 319 }
 320
 321 /**
 322  * iscsi_complete_command - finish a task
 323  * @task: iscsi cmd task
 324  *
 325  * Must be called with session lock.
 326  * This function returns the scsi command to scsi-ml or cleans
 327  * up mgmt tasks then returns the task to the pool.
 328  */
 329 static void iscsi_complete_command(struct iscsi_task *task)
 330 {
 331         struct iscsi_conn *conn = task->conn;
 332         struct iscsi_session *session = conn->session;
 333         struct scsi_cmnd *sc = task->sc;
 334
 335         list_del_init(&task->running);
 336         task->state = ISCSI_TASK_COMPLETED;
 337         task->sc = NULL;
 338
 339         if (conn->task == task)
 340                 conn->task = NULL;
 341         /*
 342          * login task is preallocated so do not free
 343          */
 344         if (conn->login_task == task)
 345                 return;
 346
 347         __kfifo_put(session->cmdpool.queue, (void*)&task, sizeof(void*));
 348
 349         if (conn->ping_task == task)
 350                 conn->ping_task = NULL;
 351
 352         if (sc) {
 353                 task->sc = NULL;
 354                 /* SCSI eh reuses commands to verify us */
 355                 sc->SCp.ptr = NULL;
 356                 /*
 357                  * queue command may call this to free the task, but
 358                  * not have setup the sc callback
 359                  */
 360                 if (sc->scsi_done)
 361                         sc->scsi_done(sc);
 362         }
 363 }
 364
 365 void __iscsi_get_task(struct iscsi_task *task)
 366 {
 367         atomic_inc(&task->refcount);
 368 }
 369 EXPORT_SYMBOL_GPL(__iscsi_get_task);
 370
 371 static void __iscsi_put_task(struct iscsi_task *task)
 372 {
 373         if (atomic_dec_and_test(&task->refcount))
 374                 iscsi_complete_command(task);
 375 }
 376
 377 void iscsi_put_task(struct iscsi_task *task)
 378 {
 379         struct iscsi_session *session = task->conn->session;
 380
 381         spin_lock_bh(&session->lock);
 382         __iscsi_put_task(task);
 383         spin_unlock_bh(&session->lock);
 384 }
 385 EXPORT_SYMBOL_GPL(iscsi_put_task);
 386
 387 /*
 388  * session lock must be held
 389  */
 390 static void fail_command(struct iscsi_conn *conn, struct iscsi_task *task,
 391                          int err)
 392 {
 393         struct scsi_cmnd *sc;
 394
 395         sc = task->sc;
 396         if (!sc)
 397                 return;
 398
 399         if (task->state == ISCSI_TASK_PENDING)
 400                 /*
 401                  * cmd never made it to the xmit thread, so we should not count
 402                  * the cmd in the sequencing
 403                  */
 404                 conn->session->queued_cmdsn--;
 405         else
 406                 conn->session->tt->cleanup_task(conn, task);
 407
 408         sc->result = err;
 409         if (!scsi_bidi_cmnd(sc))
 410                 scsi_set_resid(sc, scsi_bufflen(sc));
 411         else {
 412                 scsi_out(sc)->resid = scsi_out(sc)->length;
 413                 scsi_in(sc)->resid = scsi_in(sc)->length;
 414         }
 415
 416         if (conn->task == task)
 417                 conn->task = NULL;
 418         /* release ref from queuecommand */
 419         __iscsi_put_task(task);
 420 }
 421
 422 static int iscsi_prep_mgmt_task(struct iscsi_conn *conn,
 423                                 struct iscsi_task *task)
 424 {
 425         struct iscsi_session *session = conn->session;
 426         struct iscsi_hdr *hdr = (struct iscsi_hdr *)task->hdr;
 427         struct iscsi_nopout *nop = (struct iscsi_nopout *)hdr;
 428
 429         if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
 430                 return -ENOTCONN;
 431
 432         if (hdr->opcode != (ISCSI_OP_LOGIN | ISCSI_OP_IMMEDIATE) &&
 433             hdr->opcode != (ISCSI_OP_TEXT | ISCSI_OP_IMMEDIATE))
 434                 nop->exp_statsn = cpu_to_be32(conn->exp_statsn);
 435         /*
 436          * pre-format CmdSN for outgoing PDU.
 437          */
 438         nop->cmdsn = cpu_to_be32(session->cmdsn);
 439         if (hdr->itt != RESERVED_ITT) {
 440                 hdr->itt = build_itt(task->itt, session->age);
 441                 /*
 442                  * TODO: We always use immediate, so we never hit this.
 443                  * If we start to send tmfs or nops as non-immediate then
 444                  * we should start checking the cmdsn numbers for mgmt tasks.
 445                  */
 446                 if (conn->c_stage == ISCSI_CONN_STARTED &&
 447                     !(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
 448                         session->queued_cmdsn++;
 449                         session->cmdsn++;
 450                 }
 451         }
 452
 453         if (session->tt->init_task)
 454                 session->tt->init_task(task);
 455
 456         if ((hdr->opcode & ISCSI_OPCODE_MASK) == ISCSI_OP_LOGOUT)
 457                 session->state = ISCSI_STATE_LOGGING_OUT;
 458
 459         list_move_tail(&task->running, &conn->mgmt_run_list);
 460         debug_scsi("mgmtpdu [op 0x%x hdr->itt 0x%x datalen %d]\n",
 461                    hdr->opcode & ISCSI_OPCODE_MASK, hdr->itt,
 462                    task->data_count);
 463         return 0;
 464 }
 465
 466 static struct iscsi_task *
 467 __iscsi_conn_send_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 468                       char *data, uint32_t data_size)
 469 {
 470         struct iscsi_session *session = conn->session;
 471         struct iscsi_task *task;
 472
 473         if (session->state == ISCSI_STATE_TERMINATE)
 474                 return NULL;
 475
 476         if (hdr->opcode == (ISCSI_OP_LOGIN | ISCSI_OP_IMMEDIATE) ||
 477             hdr->opcode == (ISCSI_OP_TEXT | ISCSI_OP_IMMEDIATE))
 478                 /*
 479                  * Login and Text are sent serially, in
 480                  * request-followed-by-response sequence.
 481                  * Same task can be used. Same ITT must be used.
 482                  * Note that login_task is preallocated at conn_create().
 483                  */
 484                 task = conn->login_task;
 485         else {
 486                 BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
 487                 BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);
 488
 489                 if (!__kfifo_get(session->cmdpool.queue,
 490                                  (void*)&task, sizeof(void*)))
 491                         return NULL;
 492         }
 493         /*
 494          * released in complete pdu for task we expect a response for, and
 495          * released by the lld when it has transmitted the task for
 496          * pdus we do not expect a response for.
 497          */
 498         atomic_set(&task->refcount, 1);
 499         task->conn = conn;
 500         task->sc = NULL;
 501
 502         if (data_size) {
 503                 memcpy(task->data, data, data_size);
 504                 task->data_count = data_size;
 505         } else
 506                 task->data_count = 0;
 507
 508         memcpy(task->hdr, hdr, sizeof(struct iscsi_hdr));
 509         INIT_LIST_HEAD(&task->running);
 510         list_add_tail(&task->running, &conn->mgmtqueue);
 511
 512         if (session->tt->caps & CAP_DATA_PATH_OFFLOAD) {
 513                 if (iscsi_prep_mgmt_task(conn, task)) {
 514                         __iscsi_put_task(task);
 515                         return NULL;
 516                 }
 517
 518                 if (session->tt->xmit_task(task))
 519                         task = NULL;
 520
 521         } else
 522                 scsi_queue_work(conn->session->host, &conn->xmitwork);
 523
 524         return task;
 525 }
 526
 527 int iscsi_conn_send_pdu(struct iscsi_cls_conn *cls_conn, struct iscsi_hdr *hdr,
 528                         char *data, uint32_t data_size)
 529 {
 530         struct iscsi_conn *conn = cls_conn->dd_data;
 531         struct iscsi_session *session = conn->session;
 532         int err = 0;
 533
 534         spin_lock_bh(&session->lock);
 535         if (!__iscsi_conn_send_pdu(conn, hdr, data, data_size))
 536                 err = -EPERM;
 537         spin_unlock_bh(&session->lock);
 538         return err;
 539 }
 540 EXPORT_SYMBOL_GPL(iscsi_conn_send_pdu);
 541
 542 /**
 543  * iscsi_cmd_rsp - SCSI Command Response processing
 544  * @conn: iscsi connection
 545  * @hdr: iscsi header
 546  * @task: scsi command task
 547  * @data: cmd data buffer
 548  * @datalen: len of buffer
 549  *
 550  * iscsi_cmd_rsp sets up the scsi_cmnd fields based on the PDU and
 551  * then completes the command and task.
 552  **/
 553 static void iscsi_scsi_cmd_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 554                                struct iscsi_task *task, char *data,
 555                                int datalen)
 556 {
 557         struct iscsi_cmd_rsp *rhdr = (struct iscsi_cmd_rsp *)hdr;
 558         struct iscsi_session *session = conn->session;
 559         struct scsi_cmnd *sc = task->sc;
 560
 561         iscsi_update_cmdsn(session, (struct iscsi_nopin*)rhdr);
 562         conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 563
 564         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 565
 566         if (rhdr->response != ISCSI_STATUS_CMD_COMPLETED) {
 567                 sc->result = DID_ERROR << 16;
 568                 goto out;
 569         }
 570
 571         if (rhdr->cmd_status == SAM_STAT_CHECK_CONDITION) {
 572                 uint16_t senselen;
 573
 574                 if (datalen < 2) {
 575 invalid_datalen:
 576                         iscsi_conn_printk(KERN_ERR,  conn,
 577                                          "Got CHECK_CONDITION but invalid data "
 578                                          "buffer size of %d\n", datalen);
 579                         sc->result = DID_BAD_TARGET << 16;
 580                         goto out;
 581                 }
 582
 583                 senselen = get_unaligned_be16(data);
 584                 if (datalen < senselen)
 585                         goto invalid_datalen;
 586
 587                 memcpy(sc->sense_buffer, data + 2,
 588                        min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
 589                 debug_scsi("copied %d bytes of sense\n",
 590                            min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
 591         }
 592
 593         if (rhdr->flags & (ISCSI_FLAG_CMD_BIDI_UNDERFLOW |
 594                            ISCSI_FLAG_CMD_BIDI_OVERFLOW)) {
 595                 int res_count = be32_to_cpu(rhdr->bi_residual_count);
 596
 597                 if (scsi_bidi_cmnd(sc) && res_count > 0 &&
 598                                 (rhdr->flags & ISCSI_FLAG_CMD_BIDI_OVERFLOW ||
 599                                  res_count <= scsi_in(sc)->length))
 600                         scsi_in(sc)->resid = res_count;
 601                 else
 602                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 603         }
 604
 605         if (rhdr->flags & (ISCSI_FLAG_CMD_UNDERFLOW |
 606                            ISCSI_FLAG_CMD_OVERFLOW)) {
 607                 int res_count = be32_to_cpu(rhdr->residual_count);
 608
 609                 if (res_count > 0 &&
 610                     (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
 611                      res_count <= scsi_bufflen(sc)))
 612                         /* write side for bidi or uni-io set_resid */
 613                         scsi_set_resid(sc, res_count);
 614                 else
 615                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 616         }
 617 out:
 618         debug_scsi("done [sc %lx res %d itt 0x%x]\n",
 619                    (long)sc, sc->result, task->itt);
 620         conn->scsirsp_pdus_cnt++;
 621
 622         __iscsi_put_task(task);
 623 }
 624
 625 /**
 626  * iscsi_data_in_rsp - SCSI Data-In Response processing
 627  * @conn: iscsi connection
 628  * @hdr:  iscsi pdu
 629  * @task: scsi command task
 630  **/
 631 static void
 632 iscsi_data_in_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 633                   struct iscsi_task *task)
 634 {
 635         struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)hdr;
 636         struct scsi_cmnd *sc = task->sc;
 637
 638         if (!(rhdr->flags & ISCSI_FLAG_DATA_STATUS))
 639                 return;
 640
 641         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 642         conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 643         if (rhdr->flags & (ISCSI_FLAG_DATA_UNDERFLOW |
 644                            ISCSI_FLAG_DATA_OVERFLOW)) {
 645                 int res_count = be32_to_cpu(rhdr->residual_count);
 646
 647                 if (res_count > 0 &&
 648                     (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
 649                      res_count <= scsi_in(sc)->length))
 650                         scsi_in(sc)->resid = res_count;
 651                 else
 652                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 653         }
 654
 655         conn->scsirsp_pdus_cnt++;
 656         __iscsi_put_task(task);
 657 }
 658
 659 static void iscsi_tmf_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
 660 {
 661         struct iscsi_tm_rsp *tmf = (struct iscsi_tm_rsp *)hdr;
 662
 663         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 664         conn->tmfrsp_pdus_cnt++;
 665
 666         if (conn->tmf_state != TMF_QUEUED)
 667                 return;
 668
 669         if (tmf->response == ISCSI_TMF_RSP_COMPLETE)
 670                 conn->tmf_state = TMF_SUCCESS;
 671         else if (tmf->response == ISCSI_TMF_RSP_NO_TASK)
 672                 conn->tmf_state = TMF_NOT_FOUND;
 673         else
 674                 conn->tmf_state = TMF_FAILED;
 675         wake_up(&conn->ehwait);
 676 }
 677
 678 static void iscsi_send_nopout(struct iscsi_conn *conn, struct iscsi_nopin *rhdr)
 679 {
 680         struct iscsi_nopout hdr;
 681         struct iscsi_task *task;
 682
 683         if (!rhdr && conn->ping_task)
 684                 return;
 685
 686         memset(&hdr, 0, sizeof(struct iscsi_nopout));
 687         hdr.opcode = ISCSI_OP_NOOP_OUT | ISCSI_OP_IMMEDIATE;
 688         hdr.flags = ISCSI_FLAG_CMD_FINAL;
 689
 690         if (rhdr) {
 691                 memcpy(hdr.lun, rhdr->lun, 8);
 692                 hdr.ttt = rhdr->ttt;
 693                 hdr.itt = RESERVED_ITT;
 694         } else
 695                 hdr.ttt = RESERVED_ITT;
 696
 697         task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)&hdr, NULL, 0);
 698         if (!task)
 699                 iscsi_conn_printk(KERN_ERR, conn, "Could not send nopout\n");
 700         else if (!rhdr) {
 701                 /* only track our nops */
 702                 conn->ping_task = task;
 703                 conn->last_ping = jiffies;
 704         }
 705 }
 706
 707 static int iscsi_handle_reject(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 708                                char *data, int datalen)
 709 {
 710         struct iscsi_reject *reject = (struct iscsi_reject *)hdr;
 711         struct iscsi_hdr rejected_pdu;
 712         uint32_t itt;
 713
 714         conn->exp_statsn = be32_to_cpu(reject->statsn) + 1;
 715
 716         if (reject->reason == ISCSI_REASON_DATA_DIGEST_ERROR) {
 717                 if (ntoh24(reject->dlength) > datalen)
 718                         return ISCSI_ERR_PROTO;
 719
 720                 if (ntoh24(reject->dlength) >= sizeof(struct iscsi_hdr)) {
 721                         memcpy(&rejected_pdu, data, sizeof(struct iscsi_hdr));
 722                         itt = get_itt(rejected_pdu.itt);
 723                         iscsi_conn_printk(KERN_ERR, conn,
 724                                           "itt 0x%x had pdu (op 0x%x) rejected "
 725                                           "due to DataDigest error.\n", itt,
 726                                           rejected_pdu.opcode);
 727                 }
 728         }
 729         return 0;
 730 }
 731
 732 /**
 733  * iscsi_itt_to_task - look up task by itt
 734  * @conn: iscsi connection
 735  * @itt: itt
 736  *
 737  * This should be used for mgmt tasks like login and nops, or if
 738  * the LDD's itt space does not include the session age.
 739  *
 740  * The session lock must be held.
 741  */
 742 static struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *conn, itt_t itt)
 743 {
 744         struct iscsi_session *session = conn->session;
 745         uint32_t i;
 746
 747         if (itt == RESERVED_ITT)
 748                 return NULL;
 749
 750         i = get_itt(itt);
 751         if (i >= session->cmds_max)
 752                 return NULL;
 753
 754         return session->cmds[i];
 755 }
 756
 757 /**
 758  * __iscsi_complete_pdu - complete pdu
 759  * @conn: iscsi conn
 760  * @hdr: iscsi header
 761  * @data: data buffer
 762  * @datalen: len of data buffer
 763  *
 764  * Completes pdu processing by freeing any resources allocated at
 765  * queuecommand or send generic. session lock must be held and verify
 766  * itt must have been called.
 767  */
 768 int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 769                          char *data, int datalen)
 770 {
 771         struct iscsi_session *session = conn->session;
 772         int opcode = hdr->opcode & ISCSI_OPCODE_MASK, rc = 0;
 773         struct iscsi_task *task;
 774         uint32_t itt;
 775
 776         conn->last_recv = jiffies;
 777         rc = iscsi_verify_itt(conn, hdr->itt);
 778         if (rc)
 779                 return rc;
 780
 781         if (hdr->itt != RESERVED_ITT)
 782                 itt = get_itt(hdr->itt);
 783         else
 784                 itt = ~0U;
 785
 786         debug_scsi("[op 0x%x cid %d itt 0x%x len %d]\n",
 787                    opcode, conn->id, itt, datalen);
 788
 789         if (itt == ~0U) {
 790                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
 791
 792                 switch(opcode) {
 793                 case ISCSI_OP_NOOP_IN:
 794                         if (datalen) {
 795                                 rc = ISCSI_ERR_PROTO;
 796                                 break;
 797                         }
 798
 799                         if (hdr->ttt == cpu_to_be32(ISCSI_RESERVED_TAG))
 800                                 break;
 801
 802                         iscsi_send_nopout(conn, (struct iscsi_nopin*)hdr);
 803                         break;
 804                 case ISCSI_OP_REJECT:
 805                         rc = iscsi_handle_reject(conn, hdr, data, datalen);
 806                         break;
 807                 case ISCSI_OP_ASYNC_EVENT:
 808                         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 809                         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
 810                                 rc = ISCSI_ERR_CONN_FAILED;
 811                         break;
 812                 default:
 813                         rc = ISCSI_ERR_BAD_OPCODE;
 814                         break;
 815                 }
 816                 goto out;
 817         }
 818
 819         switch(opcode) {
 820         case ISCSI_OP_SCSI_CMD_RSP:
 821         case ISCSI_OP_SCSI_DATA_IN:
 822                 task = iscsi_itt_to_ctask(conn, hdr->itt);
 823                 if (!task)
 824                         return ISCSI_ERR_BAD_ITT;
 825                 break;
 826         case ISCSI_OP_R2T:
 827                 /*
 828                  * LLD handles R2Ts if they need to.
 829                  */
 830                 return 0;
 831         case ISCSI_OP_LOGOUT_RSP:
 832         case ISCSI_OP_LOGIN_RSP:
 833         case ISCSI_OP_TEXT_RSP:
 834         case ISCSI_OP_SCSI_TMFUNC_RSP:
 835         case ISCSI_OP_NOOP_IN:
 836                 task = iscsi_itt_to_task(conn, hdr->itt);
 837                 if (!task)
 838                         return ISCSI_ERR_BAD_ITT;
 839                 break;
 840         default:
 841                 return ISCSI_ERR_BAD_OPCODE;
 842         }
 843
 844         switch(opcode) {
 845         case ISCSI_OP_SCSI_CMD_RSP:
 846                 iscsi_scsi_cmd_rsp(conn, hdr, task, data, datalen);
 847                 break;
 848         case ISCSI_OP_SCSI_DATA_IN:
 849                 iscsi_data_in_rsp(conn, hdr, task);
 850                 break;
 851         case ISCSI_OP_LOGOUT_RSP:
 852                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
 853                 if (datalen) {
 854                         rc = ISCSI_ERR_PROTO;
 855                         break;
 856                 }
 857                 conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 858                 goto recv_pdu;
 859         case ISCSI_OP_LOGIN_RSP:
 860         case ISCSI_OP_TEXT_RSP:
 861                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
 862                 /*
 863                  * login related PDU's exp_statsn is handled in
 864                  * userspace
 865                  */
 866                 goto recv_pdu;
 867         case ISCSI_OP_SCSI_TMFUNC_RSP:
 868                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
 869                 if (datalen) {
 870                         rc = ISCSI_ERR_PROTO;
 871                         break;
 872                 }
 873
 874                 iscsi_tmf_rsp(conn, hdr);
 875                 __iscsi_put_task(task);
 876                 break;
 877         case ISCSI_OP_NOOP_IN:
 878                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
 879                 if (hdr->ttt != cpu_to_be32(ISCSI_RESERVED_TAG) || datalen) {
 880                         rc = ISCSI_ERR_PROTO;
 881                         break;
 882                 }
 883                 conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 884
 885                 if (conn->ping_task != task)
 886                         /*
 887                          * If this is not in response to one of our
 888                          * nops then it must be from userspace.
 889                          */
 890                         goto recv_pdu;
 891
 892                 mod_timer(&conn->transport_timer, jiffies + conn->recv_timeout);
 893                 __iscsi_put_task(task);
 894                 break;
 895         default:
 896                 rc = ISCSI_ERR_BAD_OPCODE;
 897                 break;
 898         }
 899
 900 out:
 901         return rc;
 902 recv_pdu:
 903         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
 904                 rc = ISCSI_ERR_CONN_FAILED;
 905         __iscsi_put_task(task);
 906         return rc;
 907 }
 908 EXPORT_SYMBOL_GPL(__iscsi_complete_pdu);
 909
 910 int iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 911                        char *data, int datalen)
 912 {
 913         int rc;
 914
 915         spin_lock(&conn->session->lock);
 916         rc = __iscsi_complete_pdu(conn, hdr, data, datalen);
 917         spin_unlock(&conn->session->lock);
 918         return rc;
 919 }
 920 EXPORT_SYMBOL_GPL(iscsi_complete_pdu);
 921
 922 int iscsi_verify_itt(struct iscsi_conn *conn, itt_t itt)
 923 {
 924         struct iscsi_session *session = conn->session;
 925         uint32_t i;
 926
 927         if (itt == RESERVED_ITT)
 928                 return 0;
 929
 930         if (((__force u32)itt & ISCSI_AGE_MASK) !=
 931             (session->age << ISCSI_AGE_SHIFT)) {
 932                 iscsi_conn_printk(KERN_ERR, conn,
 933                                   "received itt %x expected session age (%x)\n",
 934                                   (__force u32)itt, session->age);
 935                 return ISCSI_ERR_BAD_ITT;
 936         }
 937
 938         i = get_itt(itt);
 939         if (i >= session->cmds_max) {
 940                 iscsi_conn_printk(KERN_ERR, conn,
 941                                   "received invalid itt index %u (max cmds "
 942                                    "%u.\n", i, session->cmds_max);
 943                 return ISCSI_ERR_BAD_ITT;
 944         }
 945         return 0;
 946 }
 947 EXPORT_SYMBOL_GPL(iscsi_verify_itt);
 948
 949 /**
 950  * iscsi_itt_to_ctask - look up ctask by itt
 951  * @conn: iscsi connection
 952  * @itt: itt
 953  *
 954  * This should be used for cmd tasks.
 955  *
 956  * The session lock must be held.
 957  */
 958 struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *conn, itt_t itt)
 959 {
 960         struct iscsi_task *task;
 961
 962         if (iscsi_verify_itt(conn, itt))
 963                 return NULL;
 964
 965         task = iscsi_itt_to_task(conn, itt);
 966         if (!task || !task->sc)
 967                 return NULL;
 968
 969         if (task->sc->SCp.phase != conn->session->age) {
 970                 iscsi_session_printk(KERN_ERR, conn->session,
 971                                   "task's session age %d, expected %d\n",
 972                                   task->sc->SCp.phase, conn->session->age);
 973                 return NULL;
 974         }
 975
 976         return task;
 977 }
 978 EXPORT_SYMBOL_GPL(iscsi_itt_to_ctask);
 979
 980 void iscsi_session_failure(struct iscsi_cls_session *cls_session,
 981                            enum iscsi_err err)
 982 {
 983         struct iscsi_session *session = cls_session->dd_data;
 984         struct iscsi_conn *conn;
 985         struct device *dev;
 986         unsigned long flags;
 987
 988         spin_lock_irqsave(&session->lock, flags);
 989         conn = session->leadconn;
 990         if (session->state == ISCSI_STATE_TERMINATE || !conn) {
 991                 spin_unlock_irqrestore(&session->lock, flags);
 992                 return;
 993         }
 994
 995         dev = get_device(&conn->cls_conn->dev);
 996         spin_unlock_irqrestore(&session->lock, flags);
 997         if (!dev)
 998                 return;
 999         /*
1000          * if the host is being removed bypass the connection
1001          * recovery initialization because we are going to kill
1002          * the session.
1003          */
1004         if (err == ISCSI_ERR_INVALID_HOST)
1005                 iscsi_conn_error_event(conn->cls_conn, err);
1006         else
1007                 iscsi_conn_failure(conn, err);
1008         put_device(dev);
1009 }
1010 EXPORT_SYMBOL_GPL(iscsi_session_failure);
1011
1012 void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err)
1013 {
1014         struct iscsi_session *session = conn->session;
1015         unsigned long flags;
1016
1017         spin_lock_irqsave(&session->lock, flags);
1018         if (session->state == ISCSI_STATE_FAILED) {
1019                 spin_unlock_irqrestore(&session->lock, flags);
1020                 return;
1021         }
1022
1023         if (conn->stop_stage == 0)
1024                 session->state = ISCSI_STATE_FAILED;
1025         spin_unlock_irqrestore(&session->lock, flags);
1026
1027         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1028         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
1029         iscsi_conn_error_event(conn->cls_conn, err);
1030 }
1031 EXPORT_SYMBOL_GPL(iscsi_conn_failure);
1032
1033 static int iscsi_check_cmdsn_window_closed(struct iscsi_conn *conn)
1034 {
1035         struct iscsi_session *session = conn->session;
1036
1037         /*
1038          * Check for iSCSI window and take care of CmdSN wrap-around
1039          */
1040         if (!iscsi_sna_lte(session->queued_cmdsn, session->max_cmdsn)) {
1041                 debug_scsi("iSCSI CmdSN closed. ExpCmdSn %u MaxCmdSN %u "
1042                            "CmdSN %u/%u\n", session->exp_cmdsn,
1043                            session->max_cmdsn, session->cmdsn,
1044                            session->queued_cmdsn);
1045                 return -ENOSPC;
1046         }
1047         return 0;
1048 }
1049
1050 static int iscsi_xmit_task(struct iscsi_conn *conn)
1051 {
1052         struct iscsi_task *task = conn->task;
1053         int rc;
1054
1055         __iscsi_get_task(task);
1056         spin_unlock_bh(&conn->session->lock);
1057         rc = conn->session->tt->xmit_task(task);
1058         spin_lock_bh(&conn->session->lock);
1059         __iscsi_put_task(task);
1060         if (!rc)
1061                 /* done with this task */
1062                 conn->task = NULL;
1063         return rc;
1064 }
1065
1066 /**
1067  * iscsi_requeue_task - requeue task to run from session workqueue
1068  * @task: task to requeue
1069  *
1070  * LLDs that need to run a task from the session workqueue should call
1071  * this. The session lock must be held. This should only be called
1072  * by software drivers.
1073  */
1074 void iscsi_requeue_task(struct iscsi_task *task)
1075 {
1076         struct iscsi_conn *conn = task->conn;
1077
1078         list_move_tail(&task->running, &conn->requeue);
1079         scsi_queue_work(conn->session->host, &conn->xmitwork);
1080 }
1081 EXPORT_SYMBOL_GPL(iscsi_requeue_task);
1082
1083 /**
1084  * iscsi_data_xmit - xmit any command into the scheduled connection
1085  * @conn: iscsi connection
1086  *
1087  * Notes:
1088  *      The function can return -EAGAIN in which case the caller must
1089  *      re-schedule it again later or recover. '0' return code means
1090  *      successful xmit.
1091  **/
1092 static int iscsi_data_xmit(struct iscsi_conn *conn)
1093 {
1094         int rc = 0;
1095
1096         spin_lock_bh(&conn->session->lock);
1097         if (unlikely(conn->suspend_tx)) {
1098                 debug_scsi("conn %d Tx suspended!\n", conn->id);
1099                 spin_unlock_bh(&conn->session->lock);
1100                 return -ENODATA;
1101         }
1102
1103         if (conn->task) {
1104                 rc = iscsi_xmit_task(conn);
1105                 if (rc)
1106                         goto again;
1107         }
1108
1109         /*
1110          * process mgmt pdus like nops before commands since we should
1111          * only have one nop-out as a ping from us and targets should not
1112          * overflow us with nop-ins
1113          */
1114 check_mgmt:
1115         while (!list_empty(&conn->mgmtqueue)) {
1116                 conn->task = list_entry(conn->mgmtqueue.next,
1117                                          struct iscsi_task, running);
1118                 if (iscsi_prep_mgmt_task(conn, conn->task)) {
1119                         __iscsi_put_task(conn->task);
1120                         conn->task = NULL;
1121                         continue;
1122                 }
1123                 rc = iscsi_xmit_task(conn);
1124                 if (rc)
1125                         goto again;
1126         }
1127
1128         /* process pending command queue */
1129         while (!list_empty(&conn->xmitqueue)) {
1130                 if (conn->tmf_state == TMF_QUEUED)
1131                         break;
1132
1133                 conn->task = list_entry(conn->xmitqueue.next,
1134                                          struct iscsi_task, running);
1135                 if (conn->session->state == ISCSI_STATE_LOGGING_OUT) {
1136                         fail_command(conn, conn->task, DID_IMM_RETRY << 16);
1137                         continue;
1138                 }
1139                 if (iscsi_prep_scsi_cmd_pdu(conn->task)) {
1140                         fail_command(conn, conn->task, DID_ABORT << 16);
1141                         continue;
1142                 }
1143                 rc = iscsi_xmit_task(conn);
1144                 if (rc)
1145                         goto again;
1146                 /*
1147                  * we could continuously get new task requests so
1148                  * we need to check the mgmt queue for nops that need to
1149                  * be sent to aviod starvation
1150                  */
1151                 if (!list_empty(&conn->mgmtqueue))
1152                         goto check_mgmt;
1153         }
1154
1155         while (!list_empty(&conn->requeue)) {
1156                 if (conn->session->fast_abort && conn->tmf_state != TMF_INITIAL)
1157                         break;
1158
1159                 /*
1160                  * we always do fastlogout - conn stop code will clean up.
1161                  */
1162                 if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
1163                         break;
1164
1165                 conn->task = list_entry(conn->requeue.next,
1166                                          struct iscsi_task, running);
1167                 conn->task->state = ISCSI_TASK_RUNNING;
1168                 list_move_tail(conn->requeue.next, &conn->run_list);
1169                 rc = iscsi_xmit_task(conn);
1170                 if (rc)
1171                         goto again;
1172                 if (!list_empty(&conn->mgmtqueue))
1173                         goto check_mgmt;
1174         }
1175         spin_unlock_bh(&conn->session->lock);
1176         return -ENODATA;
1177
1178 again:
1179         if (unlikely(conn->suspend_tx))
1180                 rc = -ENODATA;
1181         spin_unlock_bh(&conn->session->lock);
1182         return rc;
1183 }
1184
1185 static void iscsi_xmitworker(struct work_struct *work)
1186 {
1187         struct iscsi_conn *conn =
1188                 container_of(work, struct iscsi_conn, xmitwork);
1189         int rc;
1190         /*
1191          * serialize Xmit worker on a per-connection basis.
1192          */
1193         do {
1194                 rc = iscsi_data_xmit(conn);
1195         } while (rc >= 0 || rc == -EAGAIN);
1196 }
1197
1198 enum {
1199         FAILURE_BAD_HOST = 1,
1200         FAILURE_SESSION_FAILED,
1201         FAILURE_SESSION_FREED,
1202         FAILURE_WINDOW_CLOSED,
1203         FAILURE_OOM,
1204         FAILURE_SESSION_TERMINATE,
1205         FAILURE_SESSION_IN_RECOVERY,
1206         FAILURE_SESSION_RECOVERY_TIMEOUT,
1207         FAILURE_SESSION_LOGGING_OUT,
1208         FAILURE_SESSION_NOT_READY,
1209 };
1210
1211 int iscsi_queuecommand(struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *))
1212 {
1213         struct iscsi_cls_session *cls_session;
1214         struct Scsi_Host *host;
1215         int reason = 0;
1216         struct iscsi_session *session;
1217         struct iscsi_conn *conn;
1218         struct iscsi_task *task = NULL;
1219
1220         sc->scsi_done = done;
1221         sc->result = 0;
1222         sc->SCp.ptr = NULL;
1223
1224         host = sc->device->host;
1225         spin_unlock(host->host_lock);
1226
1227         cls_session = starget_to_session(scsi_target(sc->device));
1228         session = cls_session->dd_data;
1229         spin_lock(&session->lock);
1230
1231         reason = iscsi_session_chkready(cls_session);
1232         if (reason) {
1233                 sc->result = reason;
1234                 goto fault;
1235         }
1236
1237         /*
1238          * ISCSI_STATE_FAILED is a temp. state. The recovery
1239          * code will decide what is best to do with command queued
1240          * during this time
1241          */
1242         if (session->state != ISCSI_STATE_LOGGED_IN &&
1243             session->state != ISCSI_STATE_FAILED) {
1244                 /*
1245                  * to handle the race between when we set the recovery state
1246                  * and block the session we requeue here (commands could
1247                  * be entering our queuecommand while a block is starting
1248                  * up because the block code is not locked)
1249                  */
1250                 switch (session->state) {
1251                 case ISCSI_STATE_IN_RECOVERY:
1252                         reason = FAILURE_SESSION_IN_RECOVERY;
1253                         goto reject;
1254                 case ISCSI_STATE_LOGGING_OUT:
1255                         reason = FAILURE_SESSION_LOGGING_OUT;
1256                         goto reject;
1257                 case ISCSI_STATE_RECOVERY_FAILED:
1258                         reason = FAILURE_SESSION_RECOVERY_TIMEOUT;
1259                         sc->result = DID_TRANSPORT_FAILFAST << 16;
1260                         break;
1261                 case ISCSI_STATE_TERMINATE:
1262                         reason = FAILURE_SESSION_TERMINATE;
1263                         sc->result = DID_NO_CONNECT << 16;
1264                         break;
1265                 default:
1266                         reason = FAILURE_SESSION_FREED;
1267                         sc->result = DID_NO_CONNECT << 16;
1268                 }
1269                 goto fault;
1270         }
1271
1272         conn = session->leadconn;
1273         if (!conn) {
1274                 reason = FAILURE_SESSION_FREED;
1275                 sc->result = DID_NO_CONNECT << 16;
1276                 goto fault;
1277         }
1278
1279         if (iscsi_check_cmdsn_window_closed(conn)) {
1280                 reason = FAILURE_WINDOW_CLOSED;
1281                 goto reject;
1282         }
1283
1284         if (!__kfifo_get(session->cmdpool.queue, (void*)&task,
1285                          sizeof(void*))) {
1286                 reason = FAILURE_OOM;
1287                 goto reject;
1288         }
1289         sc->SCp.phase = session->age;
1290         sc->SCp.ptr = (char *)task;
1291
1292         atomic_set(&task->refcount, 1);
1293         task->state = ISCSI_TASK_PENDING;
1294         task->conn = conn;
1295         task->sc = sc;
1296         INIT_LIST_HEAD(&task->running);
1297         list_add_tail(&task->running, &conn->xmitqueue);
1298
1299         if (session->tt->caps & CAP_DATA_PATH_OFFLOAD) {
1300                 if (iscsi_prep_scsi_cmd_pdu(task)) {
1301                         sc->result = DID_ABORT << 16;
1302                         sc->scsi_done = NULL;
1303                         iscsi_complete_command(task);
1304                         goto fault;
1305                 }
1306                 if (session->tt->xmit_task(task)) {
1307                         sc->scsi_done = NULL;
1308                         iscsi_complete_command(task);
1309                         reason = FAILURE_SESSION_NOT_READY;
1310                         goto reject;
1311                 }
1312         } else
1313                 scsi_queue_work(session->host, &conn->xmitwork);
1314
1315         session->queued_cmdsn++;
1316         spin_unlock(&session->lock);
1317         spin_lock(host->host_lock);
1318         return 0;
1319
1320 reject:
1321         spin_unlock(&session->lock);
1322         debug_scsi("cmd 0x%x rejected (%d)\n", sc->cmnd[0], reason);
1323         spin_lock(host->host_lock);
1324         return SCSI_MLQUEUE_TARGET_BUSY;
1325
1326 fault:
1327         spin_unlock(&session->lock);
1328         debug_scsi("iscsi: cmd 0x%x is not queued (%d)\n", sc->cmnd[0], reason);
1329         if (!scsi_bidi_cmnd(sc))
1330                 scsi_set_resid(sc, scsi_bufflen(sc));
1331         else {
1332                 scsi_out(sc)->resid = scsi_out(sc)->length;
1333                 scsi_in(sc)->resid = scsi_in(sc)->length;
1334         }
1335         done(sc);
1336         spin_lock(host->host_lock);
1337         return 0;
1338 }
1339 EXPORT_SYMBOL_GPL(iscsi_queuecommand);
1340
1341 int iscsi_change_queue_depth(struct scsi_device *sdev, int depth)
1342 {
1343         if (depth > ISCSI_MAX_CMD_PER_LUN)
1344                 depth = ISCSI_MAX_CMD_PER_LUN;
1345         scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
1346         return sdev->queue_depth;
1347 }
1348 EXPORT_SYMBOL_GPL(iscsi_change_queue_depth);
1349
1350 void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
1351 {
1352         struct iscsi_session *session = cls_session->dd_data;
1353
1354         spin_lock_bh(&session->lock);
1355         if (session->state != ISCSI_STATE_LOGGED_IN) {
1356                 session->state = ISCSI_STATE_RECOVERY_FAILED;
1357                 if (session->leadconn)
1358                         wake_up(&session->leadconn->ehwait);
1359         }
1360         spin_unlock_bh(&session->lock);
1361 }
1362 EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
1363
1364 int iscsi_eh_target_reset(struct scsi_cmnd *sc)
1365 {
1366         struct iscsi_cls_session *cls_session;
1367         struct iscsi_session *session;
1368         struct iscsi_conn *conn;
1369
1370         cls_session = starget_to_session(scsi_target(sc->device));
1371         session = cls_session->dd_data;
1372         conn = session->leadconn;
1373
1374         mutex_lock(&session->eh_mutex);
1375         spin_lock_bh(&session->lock);
1376         if (session->state == ISCSI_STATE_TERMINATE) {
1377 failed:
1378                 debug_scsi("failing target reset: session terminated "
1379                            "[CID %d age %d]\n", conn->id, session->age);
1380                 spin_unlock_bh(&session->lock);
1381                 mutex_unlock(&session->eh_mutex);
1382                 return FAILED;
1383         }
1384
1385         spin_unlock_bh(&session->lock);
1386         mutex_unlock(&session->eh_mutex);
1387         /*
1388          * we drop the lock here but the leadconn cannot be destoyed while
1389          * we are in the scsi eh
1390          */
1391         iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1392
1393         debug_scsi("iscsi_eh_target_reset wait for relogin\n");
1394         wait_event_interruptible(conn->ehwait,
1395                                  session->state == ISCSI_STATE_TERMINATE ||
1396                                  session->state == ISCSI_STATE_LOGGED_IN ||
1397                                  session->state == ISCSI_STATE_RECOVERY_FAILED);
1398         if (signal_pending(current))
1399                 flush_signals(current);
1400
1401         mutex_lock(&session->eh_mutex);
1402         spin_lock_bh(&session->lock);
1403         if (session->state == ISCSI_STATE_LOGGED_IN)
1404                 iscsi_session_printk(KERN_INFO, session,
1405                                      "target reset succeeded\n");
1406         else
1407                 goto failed;
1408         spin_unlock_bh(&session->lock);
1409         mutex_unlock(&session->eh_mutex);
1410         return SUCCESS;
1411 }
1412 EXPORT_SYMBOL_GPL(iscsi_eh_target_reset);
1413
1414 static void iscsi_tmf_timedout(unsigned long data)
1415 {
1416         struct iscsi_conn *conn = (struct iscsi_conn *)data;
1417         struct iscsi_session *session = conn->session;
1418
1419         spin_lock(&session->lock);
1420         if (conn->tmf_state == TMF_QUEUED) {
1421                 conn->tmf_state = TMF_TIMEDOUT;
1422                 debug_scsi("tmf timedout\n");
1423                 /* unblock eh_abort() */
1424                 wake_up(&conn->ehwait);
1425         }
1426         spin_unlock(&session->lock);
1427 }
1428
1429 static int iscsi_exec_task_mgmt_fn(struct iscsi_conn *conn,
1430                                    struct iscsi_tm *hdr, int age,
1431                                    int timeout)
1432 {
1433         struct iscsi_session *session = conn->session;
1434         struct iscsi_task *task;
1435
1436         task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)hdr,
1437                                       NULL, 0);
1438         if (!task) {
1439                 spin_unlock_bh(&session->lock);
1440                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1441                 spin_lock_bh(&session->lock);
1442                 debug_scsi("tmf exec failure\n");
1443                 return -EPERM;
1444         }
1445         conn->tmfcmd_pdus_cnt++;
1446         conn->tmf_timer.expires = timeout * HZ + jiffies;
1447         conn->tmf_timer.function = iscsi_tmf_timedout;
1448         conn->tmf_timer.data = (unsigned long)conn;
1449         add_timer(&conn->tmf_timer);
1450         debug_scsi("tmf set timeout\n");
1451
1452         spin_unlock_bh(&session->lock);
1453         mutex_unlock(&session->eh_mutex);
1454
1455         /*
1456          * block eh thread until:
1457          *
1458          * 1) tmf response
1459          * 2) tmf timeout
1460          * 3) session is terminated or restarted or userspace has
1461          * given up on recovery
1462          */
1463         wait_event_interruptible(conn->ehwait, age != session->age ||
1464                                  session->state != ISCSI_STATE_LOGGED_IN ||
1465                                  conn->tmf_state != TMF_QUEUED);
1466         if (signal_pending(current))
1467                 flush_signals(current);
1468         del_timer_sync(&conn->tmf_timer);
1469
1470         mutex_lock(&session->eh_mutex);
1471         spin_lock_bh(&session->lock);
1472         /* if the session drops it will clean up the task */
1473         if (age != session->age ||
1474             session->state != ISCSI_STATE_LOGGED_IN)
1475                 return -ENOTCONN;
1476         return 0;
1477 }
1478
1479 /*
1480  * Fail commands. session lock held and recv side suspended and xmit
1481  * thread flushed
1482  */
1483 static void fail_all_commands(struct iscsi_conn *conn, unsigned lun,
1484                               int error)
1485 {
1486         struct iscsi_task *task, *tmp;
1487
1488         if (conn->task && (conn->task->sc->device->lun == lun || lun == -1))
1489                 conn->task = NULL;
1490
1491         /* flush pending */
1492         list_for_each_entry_safe(task, tmp, &conn->xmitqueue, running) {
1493                 if (lun == task->sc->device->lun || lun == -1) {
1494                         debug_scsi("failing pending sc %p itt 0x%x\n",
1495                                    task->sc, task->itt);
1496                         fail_command(conn, task, error << 16);
1497                 }
1498         }
1499
1500         list_for_each_entry_safe(task, tmp, &conn->requeue, running) {
1501                 if (lun == task->sc->device->lun || lun == -1) {
1502                         debug_scsi("failing requeued sc %p itt 0x%x\n",
1503                                    task->sc, task->itt);
1504                         fail_command(conn, task, error << 16);
1505                 }
1506         }
1507
1508         /* fail all other running */
1509         list_for_each_entry_safe(task, tmp, &conn->run_list, running) {
1510                 if (lun == task->sc->device->lun || lun == -1) {
1511                         debug_scsi("failing in progress sc %p itt 0x%x\n",
1512                                    task->sc, task->itt);
1513                         fail_command(conn, task, error << 16);
1514                 }
1515         }
1516 }
1517
1518 void iscsi_suspend_tx(struct iscsi_conn *conn)
1519 {
1520         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1521         if (!(conn->session->tt->caps & CAP_DATA_PATH_OFFLOAD))
1522                 scsi_flush_work(conn->session->host);
1523 }
1524 EXPORT_SYMBOL_GPL(iscsi_suspend_tx);
1525
1526 static void iscsi_start_tx(struct iscsi_conn *conn)
1527 {
1528         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1529         if (!(conn->session->tt->caps & CAP_DATA_PATH_OFFLOAD))
1530                 scsi_queue_work(conn->session->host, &conn->xmitwork);
1531 }
1532
1533 static enum blk_eh_timer_return iscsi_eh_cmd_timed_out(struct scsi_cmnd *scmd)
1534 {
1535         struct iscsi_cls_session *cls_session;
1536         struct iscsi_session *session;
1537         struct iscsi_conn *conn;
1538         enum blk_eh_timer_return rc = BLK_EH_NOT_HANDLED;
1539
1540         cls_session = starget_to_session(scsi_target(scmd->device));
1541         session = cls_session->dd_data;
1542
1543         debug_scsi("scsi cmd %p timedout\n", scmd);
1544
1545         spin_lock(&session->lock);
1546         if (session->state != ISCSI_STATE_LOGGED_IN) {
1547                 /*
1548                  * We are probably in the middle of iscsi recovery so let
1549                  * that complete and handle the error.
1550                  */
1551                 rc = BLK_EH_RESET_TIMER;
1552                 goto done;
1553         }
1554
1555         conn = session->leadconn;
1556         if (!conn) {
1557                 /* In the middle of shuting down */
1558                 rc = BLK_EH_RESET_TIMER;
1559                 goto done;
1560         }
1561
1562         if (!conn->recv_timeout && !conn->ping_timeout)
1563                 goto done;
1564         /*
1565          * if the ping timedout then we are in the middle of cleaning up
1566          * and can let the iscsi eh handle it
1567          */
1568         if (time_before_eq(conn->last_recv + (conn->recv_timeout * HZ) +
1569                             (conn->ping_timeout * HZ), jiffies))
1570                 rc = BLK_EH_RESET_TIMER;
1571         /*
1572          * if we are about to check the transport then give the command
1573          * more time
1574          */
1575         if (time_before_eq(conn->last_recv + (conn->recv_timeout * HZ),
1576                            jiffies))
1577                 rc = BLK_EH_RESET_TIMER;
1578         /* if in the middle of checking the transport then give us more time */
1579         if (conn->ping_task)
1580                 rc = BLK_EH_RESET_TIMER;
1581 done:
1582         spin_unlock(&session->lock);
1583         debug_scsi("return %s\n", rc == BLK_EH_RESET_TIMER ?
1584                                         "timer reset" : "nh");
1585         return rc;
1586 }
1587
1588 static void iscsi_check_transport_timeouts(unsigned long data)
1589 {
1590         struct iscsi_conn *conn = (struct iscsi_conn *)data;
1591         struct iscsi_session *session = conn->session;
1592         unsigned long recv_timeout, next_timeout = 0, last_recv;
1593
1594         spin_lock(&session->lock);
1595         if (session->state != ISCSI_STATE_LOGGED_IN)
1596                 goto done;
1597
1598         recv_timeout = conn->recv_timeout;
1599         if (!recv_timeout)
1600                 goto done;
1601
1602         recv_timeout *= HZ;
1603         last_recv = conn->last_recv;
1604         if (conn->ping_task &&
1605             time_before_eq(conn->last_ping + (conn->ping_timeout * HZ),
1606                            jiffies)) {
1607                 iscsi_conn_printk(KERN_ERR, conn, "ping timeout of %d secs "
1608                                   "expired, last rx %lu, last ping %lu, "
1609                                   "now %lu\n", conn->ping_timeout, last_recv,
1610                                   conn->last_ping, jiffies);
1611                 spin_unlock(&session->lock);
1612                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1613                 return;
1614         }
1615
1616         if (time_before_eq(last_recv + recv_timeout, jiffies)) {
1617                 /* send a ping to try to provoke some traffic */
1618                 debug_scsi("Sending nopout as ping on conn %p\n", conn);
1619                 iscsi_send_nopout(conn, NULL);
1620                 next_timeout = conn->last_ping + (conn->ping_timeout * HZ);
1621         } else
1622                 next_timeout = last_recv + recv_timeout;
1623
1624         debug_scsi("Setting next tmo %lu\n", next_timeout);
1625         mod_timer(&conn->transport_timer, next_timeout);
1626 done:
1627         spin_unlock(&session->lock);
1628 }
1629
1630 static void iscsi_prep_abort_task_pdu(struct iscsi_task *task,
1631                                       struct iscsi_tm *hdr)
1632 {
1633         memset(hdr, 0, sizeof(*hdr));
1634         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
1635         hdr->flags = ISCSI_TM_FUNC_ABORT_TASK & ISCSI_FLAG_TM_FUNC_MASK;
1636         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
1637         memcpy(hdr->lun, task->hdr->lun, sizeof(hdr->lun));
1638         hdr->rtt = task->hdr->itt;
1639         hdr->refcmdsn = task->hdr->cmdsn;
1640 }
1641
1642 int iscsi_eh_abort(struct scsi_cmnd *sc)
1643 {
1644         struct iscsi_cls_session *cls_session;
1645         struct iscsi_session *session;
1646         struct iscsi_conn *conn;
1647         struct iscsi_task *task;
1648         struct iscsi_tm *hdr;
1649         int rc, age;
1650
1651         cls_session = starget_to_session(scsi_target(sc->device));
1652         session = cls_session->dd_data;
1653
1654         mutex_lock(&session->eh_mutex);
1655         spin_lock_bh(&session->lock);
1656         /*
1657          * if session was ISCSI_STATE_IN_RECOVERY then we may not have
1658          * got the command.
1659          */
1660         if (!sc->SCp.ptr) {
1661                 debug_scsi("sc never reached iscsi layer or it completed.\n");
1662                 spin_unlock_bh(&session->lock);
1663                 mutex_unlock(&session->eh_mutex);
1664                 return SUCCESS;
1665         }
1666
1667         /*
1668          * If we are not logged in or we have started a new session
1669          * then let the host reset code handle this
1670          */
1671         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN ||
1672             sc->SCp.phase != session->age) {
1673                 spin_unlock_bh(&session->lock);
1674                 mutex_unlock(&session->eh_mutex);
1675                 return FAILED;
1676         }
1677
1678         conn = session->leadconn;
1679         conn->eh_abort_cnt++;
1680         age = session->age;
1681
1682         task = (struct iscsi_task *)sc->SCp.ptr;
1683         debug_scsi("aborting [sc %p itt 0x%x]\n", sc, task->itt);
1684
1685         /* task completed before time out */
1686         if (!task->sc) {
1687                 debug_scsi("sc completed while abort in progress\n");
1688                 goto success;
1689         }
1690
1691         if (task->state == ISCSI_TASK_PENDING) {
1692                 fail_command(conn, task, DID_ABORT << 16);
1693                 goto success;
1694         }
1695
1696         /* only have one tmf outstanding at a time */
1697         if (conn->tmf_state != TMF_INITIAL)
1698                 goto failed;
1699         conn->tmf_state = TMF_QUEUED;
1700
1701         hdr = &conn->tmhdr;
1702         iscsi_prep_abort_task_pdu(task, hdr);
1703
1704         if (iscsi_exec_task_mgmt_fn(conn, hdr, age, session->abort_timeout)) {
1705                 rc = FAILED;
1706                 goto failed;
1707         }
1708
1709         switch (conn->tmf_state) {
1710         case TMF_SUCCESS:
1711                 spin_unlock_bh(&session->lock);
1712                 /*
1713                  * stop tx side incase the target had sent a abort rsp but
1714                  * the initiator was still writing out data.
1715                  */
1716                 iscsi_suspend_tx(conn);
1717                 /*
1718                  * we do not stop the recv side because targets have been
1719                  * good and have never sent us a successful tmf response
1720                  * then sent more data for the cmd.
1721                  */
1722                 spin_lock(&session->lock);
1723                 fail_command(conn, task, DID_ABORT << 16);
1724                 conn->tmf_state = TMF_INITIAL;
1725                 spin_unlock(&session->lock);
1726                 iscsi_start_tx(conn);
1727                 goto success_unlocked;
1728         case TMF_TIMEDOUT:
1729                 spin_unlock_bh(&session->lock);
1730                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1731                 goto failed_unlocked;
1732         case TMF_NOT_FOUND:
1733                 if (!sc->SCp.ptr) {
1734                         conn->tmf_state = TMF_INITIAL;
1735                         /* task completed before tmf abort response */
1736                         debug_scsi("sc completed while abort in progress\n");
1737                         goto success;
1738                 }
1739                 /* fall through */
1740         default:
1741                 conn->tmf_state = TMF_INITIAL;
1742                 goto failed;
1743         }
1744
1745 success:
1746         spin_unlock_bh(&session->lock);
1747 success_unlocked:
1748         debug_scsi("abort success [sc %lx itt 0x%x]\n", (long)sc, task->itt);
1749         mutex_unlock(&session->eh_mutex);
1750         return SUCCESS;
1751
1752 failed:
1753         spin_unlock_bh(&session->lock);
1754 failed_unlocked:
1755         debug_scsi("abort failed [sc %p itt 0x%x]\n", sc,
1756                     task ? task->itt : 0);
1757         mutex_unlock(&session->eh_mutex);
1758         return FAILED;
1759 }
1760 EXPORT_SYMBOL_GPL(iscsi_eh_abort);
1761
1762 static void iscsi_prep_lun_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
1763 {
1764         memset(hdr, 0, sizeof(*hdr));
1765         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
1766         hdr->flags = ISCSI_TM_FUNC_LOGICAL_UNIT_RESET & ISCSI_FLAG_TM_FUNC_MASK;
1767         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
1768         int_to_scsilun(sc->device->lun, (struct scsi_lun *)hdr->lun);
1769         hdr->rtt = RESERVED_ITT;
1770 }
1771
1772 int iscsi_eh_device_reset(struct scsi_cmnd *sc)
1773 {
1774         struct iscsi_cls_session *cls_session;
1775         struct iscsi_session *session;
1776         struct iscsi_conn *conn;
1777         struct iscsi_tm *hdr;
1778         int rc = FAILED;
1779
1780         cls_session = starget_to_session(scsi_target(sc->device));
1781         session = cls_session->dd_data;
1782
1783         debug_scsi("LU Reset [sc %p lun %u]\n", sc, sc->device->lun);
1784
1785         mutex_lock(&session->eh_mutex);
1786         spin_lock_bh(&session->lock);
1787         /*
1788          * Just check if we are not logged in. We cannot check for
1789          * the phase because the reset could come from a ioctl.
1790          */
1791         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
1792                 goto unlock;
1793         conn = session->leadconn;
1794
1795         /* only have one tmf outstanding at a time */
1796         if (conn->tmf_state != TMF_INITIAL)
1797                 goto unlock;
1798         conn->tmf_state = TMF_QUEUED;
1799
1800         hdr = &conn->tmhdr;
1801         iscsi_prep_lun_reset_pdu(sc, hdr);
1802
1803         if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
1804                                     session->lu_reset_timeout)) {
1805                 rc = FAILED;
1806                 goto unlock;
1807         }
1808
1809         switch (conn->tmf_state) {
1810         case TMF_SUCCESS:
1811                 break;
1812         case TMF_TIMEDOUT:
1813                 spin_unlock_bh(&session->lock);
1814                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1815                 goto done;
1816         default:
1817                 conn->tmf_state = TMF_INITIAL;
1818                 goto unlock;
1819         }
1820
1821         rc = SUCCESS;
1822         spin_unlock_bh(&session->lock);
1823
1824         iscsi_suspend_tx(conn);
1825
1826         spin_lock_bh(&session->lock);
1827         fail_all_commands(conn, sc->device->lun, DID_ERROR);
1828         conn->tmf_state = TMF_INITIAL;
1829         spin_unlock_bh(&session->lock);
1830
1831         iscsi_start_tx(conn);
1832         goto done;
1833
1834 unlock:
1835         spin_unlock_bh(&session->lock);
1836 done:
1837         debug_scsi("iscsi_eh_device_reset %s\n",
1838                   rc == SUCCESS ? "SUCCESS" : "FAILED");
1839         mutex_unlock(&session->eh_mutex);
1840         return rc;
1841 }
1842 EXPORT_SYMBOL_GPL(iscsi_eh_device_reset);
1843
1844 /*
1845  * Pre-allocate a pool of @max items of @item_size. By default, the pool
1846  * should be accessed via kfifo_{get,put} on q->queue.
1847  * Optionally, the caller can obtain the array of object pointers
1848  * by passing in a non-NULL @items pointer
1849  */
1850 int
1851 iscsi_pool_init(struct iscsi_pool *q, int max, void ***items, int item_size)
1852 {
1853         int i, num_arrays = 1;
1854
1855         memset(q, 0, sizeof(*q));
1856
1857         q->max = max;
1858
1859         /* If the user passed an items pointer, he wants a copy of
1860          * the array. */
1861         if (items)
1862                 num_arrays++;
1863         q->pool = kzalloc(num_arrays * max * sizeof(void*), GFP_KERNEL);
1864         if (q->pool == NULL)
1865                 goto enomem;
1866
1867         q->queue = kfifo_init((void*)q->pool, max * sizeof(void*),
1868                               GFP_KERNEL, NULL);
1869         if (q->queue == ERR_PTR(-ENOMEM))
1870                 goto enomem;
1871
1872         for (i = 0; i < max; i++) {
1873                 q->pool[i] = kzalloc(item_size, GFP_KERNEL);
1874                 if (q->pool[i] == NULL) {
1875                         q->max = i;
1876                         goto enomem;
1877                 }
1878                 __kfifo_put(q->queue, (void*)&q->pool[i], sizeof(void*));
1879         }
1880
1881         if (items) {
1882                 *items = q->pool + max;
1883                 memcpy(*items, q->pool, max * sizeof(void *));
1884         }
1885
1886         return 0;
1887
1888 enomem:
1889         iscsi_pool_free(q);
1890         return -ENOMEM;
1891 }
1892 EXPORT_SYMBOL_GPL(iscsi_pool_init);
1893
1894 void iscsi_pool_free(struct iscsi_pool *q)
1895 {
1896         int i;
1897
1898         for (i = 0; i < q->max; i++)
1899                 kfree(q->pool[i]);
1900         if (q->pool)
1901                 kfree(q->pool);
1902 }
1903 EXPORT_SYMBOL_GPL(iscsi_pool_free);
1904
1905 /**
1906  * iscsi_host_add - add host to system
1907  * @shost: scsi host
1908  * @pdev: parent device
1909  *
1910  * This should be called by partial offload and software iscsi drivers
1911  * to add a host to the system.
1912  */
1913 int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev)
1914 {
1915         if (!shost->can_queue)
1916                 shost->can_queue = ISCSI_DEF_XMIT_CMDS_MAX;
1917
1918         return scsi_add_host(shost, pdev);
1919 }
1920 EXPORT_SYMBOL_GPL(iscsi_host_add);
1921
1922 /**
1923  * iscsi_host_alloc - allocate a host and driver data
1924  * @sht: scsi host template
1925  * @dd_data_size: driver host data size
1926  * @qdepth: default device queue depth
1927  *
1928  * This should be called by partial offload and software iscsi drivers.
1929  * To access the driver specific memory use the iscsi_host_priv() macro.
1930  */
1931 struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
1932                                    int dd_data_size, uint16_t qdepth)
1933 {
1934         struct Scsi_Host *shost;
1935         struct iscsi_host *ihost;
1936
1937         shost = scsi_host_alloc(sht, sizeof(struct iscsi_host) + dd_data_size);
1938         if (!shost)
1939                 return NULL;
1940         shost->transportt->eh_timed_out = iscsi_eh_cmd_timed_out;
1941
1942         if (qdepth > ISCSI_MAX_CMD_PER_LUN || qdepth < 1) {
1943                 if (qdepth != 0)
1944                         printk(KERN_ERR "iscsi: invalid queue depth of %d. "
1945                                "Queue depth must be between 1 and %d.\n",
1946                                qdepth, ISCSI_MAX_CMD_PER_LUN);
1947                 qdepth = ISCSI_DEF_CMD_PER_LUN;
1948         }
1949         shost->cmd_per_lun = qdepth;
1950
1951         ihost = shost_priv(shost);
1952         spin_lock_init(&ihost->lock);
1953         ihost->state = ISCSI_HOST_SETUP;
1954         ihost->num_sessions = 0;
1955         init_waitqueue_head(&ihost->session_removal_wq);
1956         return shost;
1957 }
1958 EXPORT_SYMBOL_GPL(iscsi_host_alloc);
1959
1960 static void iscsi_notify_host_removed(struct iscsi_cls_session *cls_session)
1961 {
1962         iscsi_session_failure(cls_session, ISCSI_ERR_INVALID_HOST);
1963 }
1964
1965 /**
1966  * iscsi_host_remove - remove host and sessions
1967  * @shost: scsi host
1968  *
1969  * If there are any sessions left, this will initiate the removal and wait
1970  * for the completion.
1971  */
1972 void iscsi_host_remove(struct Scsi_Host *shost)
1973 {
1974         struct iscsi_host *ihost = shost_priv(shost);
1975         unsigned long flags;
1976
1977         spin_lock_irqsave(&ihost->lock, flags);
1978         ihost->state = ISCSI_HOST_REMOVED;
1979         spin_unlock_irqrestore(&ihost->lock, flags);
1980
1981         iscsi_host_for_each_session(shost, iscsi_notify_host_removed);
1982         wait_event_interruptible(ihost->session_removal_wq,
1983                                  ihost->num_sessions == 0);
1984         if (signal_pending(current))
1985                 flush_signals(current);
1986
1987         scsi_remove_host(shost);
1988 }
1989 EXPORT_SYMBOL_GPL(iscsi_host_remove);
1990
1991 void iscsi_host_free(struct Scsi_Host *shost)
1992 {
1993         struct iscsi_host *ihost = shost_priv(shost);
1994
1995         kfree(ihost->netdev);
1996         kfree(ihost->hwaddress);
1997         kfree(ihost->initiatorname);
1998         scsi_host_put(shost);
1999 }
2000 EXPORT_SYMBOL_GPL(iscsi_host_free);
2001
2002 static void iscsi_host_dec_session_cnt(struct Scsi_Host *shost)
2003 {
2004         struct iscsi_host *ihost = shost_priv(shost);
2005         unsigned long flags;
2006
2007         shost = scsi_host_get(shost);
2008         if (!shost) {
2009                 printk(KERN_ERR "Invalid state. Cannot notify host removal "
2010                       "of session teardown event because host already "
2011                       "removed.\n");
2012                 return;
2013         }
2014
2015         spin_lock_irqsave(&ihost->lock, flags);
2016         ihost->num_sessions--;
2017         if (ihost->num_sessions == 0)
2018                 wake_up(&ihost->session_removal_wq);
2019         spin_unlock_irqrestore(&ihost->lock, flags);
2020         scsi_host_put(shost);
2021 }
2022
2023 /**
2024  * iscsi_session_setup - create iscsi cls session and host and session
2025  * @iscsit: iscsi transport template
2026  * @shost: scsi host
2027  * @cmds_max: session can queue
2028  * @cmd_task_size: LLD task private data size
2029  * @initial_cmdsn: initial CmdSN
2030  *
2031  * This can be used by software iscsi_transports that allocate
2032  * a session per scsi host.
2033  *
2034  * Callers should set cmds_max to the largest total numer (mgmt + scsi) of
2035  * tasks they support. The iscsi layer reserves ISCSI_MGMT_CMDS_MAX tasks
2036  * for nop handling and login/logout requests.
2037  */
2038 struct iscsi_cls_session *
2039 iscsi_session_setup(struct iscsi_transport *iscsit, struct Scsi_Host *shost,
2040                     uint16_t cmds_max, int cmd_task_size,
2041                     uint32_t initial_cmdsn, unsigned int id)
2042 {
2043         struct iscsi_host *ihost = shost_priv(shost);
2044         struct iscsi_session *session;
2045         struct iscsi_cls_session *cls_session;
2046         int cmd_i, scsi_cmds, total_cmds = cmds_max;
2047         unsigned long flags;
2048
2049         spin_lock_irqsave(&ihost->lock, flags);
2050         if (ihost->state == ISCSI_HOST_REMOVED) {
2051                 spin_unlock_irqrestore(&ihost->lock, flags);
2052                 return NULL;
2053         }
2054         ihost->num_sessions++;
2055         spin_unlock_irqrestore(&ihost->lock, flags);
2056
2057         if (!total_cmds)
2058                 total_cmds = ISCSI_DEF_XMIT_CMDS_MAX;
2059         /*
2060          * The iscsi layer needs some tasks for nop handling and tmfs,
2061          * so the cmds_max must at least be greater than ISCSI_MGMT_CMDS_MAX
2062          * + 1 command for scsi IO.
2063          */
2064         if (total_cmds < ISCSI_TOTAL_CMDS_MIN) {
2065                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2066                        "must be a power of two that is at least %d.\n",
2067                        total_cmds, ISCSI_TOTAL_CMDS_MIN);
2068                 goto dec_session_count;
2069         }
2070
2071         if (total_cmds > ISCSI_TOTAL_CMDS_MAX) {
2072                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2073                        "must be a power of 2 less than or equal to %d.\n",
2074                        cmds_max, ISCSI_TOTAL_CMDS_MAX);
2075                 total_cmds = ISCSI_TOTAL_CMDS_MAX;
2076         }
2077
2078         if (!is_power_of_2(total_cmds)) {
2079                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2080                        "must be a power of 2.\n", total_cmds);
2081                 total_cmds = rounddown_pow_of_two(total_cmds);
2082                 if (total_cmds < ISCSI_TOTAL_CMDS_MIN)
2083                         return NULL;
2084                 printk(KERN_INFO "iscsi: Rounding can_queue to %d.\n",
2085                        total_cmds);
2086         }
2087         scsi_cmds = total_cmds - ISCSI_MGMT_CMDS_MAX;
2088
2089         cls_session = iscsi_alloc_session(shost, iscsit,
2090                                           sizeof(struct iscsi_session));
2091         if (!cls_session)
2092                 goto dec_session_count;
2093         session = cls_session->dd_data;
2094         session->cls_session = cls_session;
2095         session->host = shost;
2096         session->state = ISCSI_STATE_FREE;
2097         session->fast_abort = 1;
2098         session->lu_reset_timeout = 15;
2099         session->abort_timeout = 10;
2100         session->scsi_cmds_max = scsi_cmds;
2101         session->cmds_max = total_cmds;
2102         session->queued_cmdsn = session->cmdsn = initial_cmdsn;
2103         session->exp_cmdsn = initial_cmdsn + 1;
2104         session->max_cmdsn = initial_cmdsn + 1;
2105         session->max_r2t = 1;
2106         session->tt = iscsit;
2107         mutex_init(&session->eh_mutex);
2108         spin_lock_init(&session->lock);
2109
2110         /* initialize SCSI PDU commands pool */
2111         if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
2112                             (void***)&session->cmds,
2113                             cmd_task_size + sizeof(struct iscsi_task)))
2114                 goto cmdpool_alloc_fail;
2115
2116         /* pre-format cmds pool with ITT */
2117         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
2118                 struct iscsi_task *task = session->cmds[cmd_i];
2119
2120                 if (cmd_task_size)
2121                         task->dd_data = &task[1];
2122                 task->itt = cmd_i;
2123                 INIT_LIST_HEAD(&task->running);
2124         }
2125
2126         if (!try_module_get(iscsit->owner))
2127                 goto module_get_fail;
2128
2129         if (iscsi_add_session(cls_session, id))
2130                 goto cls_session_fail;
2131
2132         return cls_session;
2133
2134 cls_session_fail:
2135         module_put(iscsit->owner);
2136 module_get_fail:
2137         iscsi_pool_free(&session->cmdpool);
2138 cmdpool_alloc_fail:
2139         iscsi_free_session(cls_session);
2140 dec_session_count:
2141         iscsi_host_dec_session_cnt(shost);
2142         return NULL;
2143 }
2144 EXPORT_SYMBOL_GPL(iscsi_session_setup);
2145
2146 /**
2147  * iscsi_session_teardown - destroy session, host, and cls_session
2148  * @cls_session: iscsi session
2149  *
2150  * The driver must have called iscsi_remove_session before
2151  * calling this.
2152  */
2153 void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
2154 {
2155         struct iscsi_session *session = cls_session->dd_data;
2156         struct module *owner = cls_session->transport->owner;
2157         struct Scsi_Host *shost = session->host;
2158
2159         iscsi_pool_free(&session->cmdpool);
2160
2161         kfree(session->password);
2162         kfree(session->password_in);
2163         kfree(session->username);
2164         kfree(session->username_in);
2165         kfree(session->targetname);
2166         kfree(session->initiatorname);
2167         kfree(session->ifacename);
2168
2169         iscsi_destroy_session(cls_session);
2170         iscsi_host_dec_session_cnt(shost);
2171         module_put(owner);
2172 }
2173 EXPORT_SYMBOL_GPL(iscsi_session_teardown);
2174
2175 /**
2176  * iscsi_conn_setup - create iscsi_cls_conn and iscsi_conn
2177  * @cls_session: iscsi_cls_session
2178  * @dd_size: private driver data size
2179  * @conn_idx: cid
2180  */
2181 struct iscsi_cls_conn *
2182 iscsi_conn_setup(struct iscsi_cls_session *cls_session, int dd_size,
2183                  uint32_t conn_idx)
2184 {
2185         struct iscsi_session *session = cls_session->dd_data;
2186         struct iscsi_conn *conn;
2187         struct iscsi_cls_conn *cls_conn;
2188         char *data;
2189
2190         cls_conn = iscsi_create_conn(cls_session, sizeof(*conn) + dd_size,
2191                                      conn_idx);
2192         if (!cls_conn)
2193                 return NULL;
2194         conn = cls_conn->dd_data;
2195         memset(conn, 0, sizeof(*conn) + dd_size);
2196
2197         conn->dd_data = cls_conn->dd_data + sizeof(*conn);
2198         conn->session = session;
2199         conn->cls_conn = cls_conn;
2200         conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
2201         conn->id = conn_idx;
2202         conn->exp_statsn = 0;
2203         conn->tmf_state = TMF_INITIAL;
2204
2205         init_timer(&conn->transport_timer);
2206         conn->transport_timer.data = (unsigned long)conn;
2207         conn->transport_timer.function = iscsi_check_transport_timeouts;
2208
2209         INIT_LIST_HEAD(&conn->run_list);
2210         INIT_LIST_HEAD(&conn->mgmt_run_list);
2211         INIT_LIST_HEAD(&conn->mgmtqueue);
2212         INIT_LIST_HEAD(&conn->xmitqueue);
2213         INIT_LIST_HEAD(&conn->requeue);
2214         INIT_WORK(&conn->xmitwork, iscsi_xmitworker);
2215
2216         /* allocate login_task used for the login/text sequences */
2217         spin_lock_bh(&session->lock);
2218         if (!__kfifo_get(session->cmdpool.queue,
2219                          (void*)&conn->login_task,
2220                          sizeof(void*))) {
2221                 spin_unlock_bh(&session->lock);
2222                 goto login_task_alloc_fail;
2223         }
2224         spin_unlock_bh(&session->lock);
2225
2226         data = kmalloc(ISCSI_DEF_MAX_RECV_SEG_LEN, GFP_KERNEL);
2227         if (!data)
2228                 goto login_task_data_alloc_fail;
2229         conn->login_task->data = conn->data = data;
2230
2231         init_timer(&conn->tmf_timer);
2232         init_waitqueue_head(&conn->ehwait);
2233
2234         return cls_conn;
2235
2236 login_task_data_alloc_fail:
2237         __kfifo_put(session->cmdpool.queue, (void*)&conn->login_task,
2238                     sizeof(void*));
2239 login_task_alloc_fail:
2240         iscsi_destroy_conn(cls_conn);
2241         return NULL;
2242 }
2243 EXPORT_SYMBOL_GPL(iscsi_conn_setup);
2244
2245 /**
2246  * iscsi_conn_teardown - teardown iscsi connection
2247  * cls_conn: iscsi class connection
2248  *
2249  * TODO: we may need to make this into a two step process
2250  * like scsi-mls remove + put host
2251  */
2252 void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
2253 {
2254         struct iscsi_conn *conn = cls_conn->dd_data;
2255         struct iscsi_session *session = conn->session;
2256         unsigned long flags;
2257
2258         del_timer_sync(&conn->transport_timer);
2259
2260         spin_lock_bh(&session->lock);
2261         conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
2262         if (session->leadconn == conn) {
2263                 /*
2264                  * leading connection? then give up on recovery.
2265                  */
2266                 session->state = ISCSI_STATE_TERMINATE;
2267                 wake_up(&conn->ehwait);
2268         }
2269         spin_unlock_bh(&session->lock);
2270
2271         /*
2272          * Block until all in-progress commands for this connection
2273          * time out or fail.
2274          */
2275         for (;;) {
2276                 spin_lock_irqsave(session->host->host_lock, flags);
2277                 if (!session->host->host_busy) { /* OK for ERL == 0 */
2278                         spin_unlock_irqrestore(session->host->host_lock, flags);
2279                         break;
2280                 }
2281                 spin_unlock_irqrestore(session->host->host_lock, flags);
2282                 msleep_interruptible(500);
2283                 iscsi_conn_printk(KERN_INFO, conn, "iscsi conn_destroy(): "
2284                                   "host_busy %d host_failed %d\n",
2285                                   session->host->host_busy,
2286                                   session->host->host_failed);
2287                 /*
2288                  * force eh_abort() to unblock
2289                  */
2290                 wake_up(&conn->ehwait);
2291         }
2292
2293         /* flush queued up work because we free the connection below */
2294         iscsi_suspend_tx(conn);
2295
2296         spin_lock_bh(&session->lock);
2297         kfree(conn->data);
2298         kfree(conn->persistent_address);
2299         __kfifo_put(session->cmdpool.queue, (void*)&conn->login_task,
2300                     sizeof(void*));
2301         if (session->leadconn == conn)
2302                 session->leadconn = NULL;
2303         spin_unlock_bh(&session->lock);
2304
2305         iscsi_destroy_conn(cls_conn);
2306 }
2307 EXPORT_SYMBOL_GPL(iscsi_conn_teardown);
2308
2309 int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
2310 {
2311         struct iscsi_conn *conn = cls_conn->dd_data;
2312         struct iscsi_session *session = conn->session;
2313
2314         if (!session) {
2315                 iscsi_conn_printk(KERN_ERR, conn,
2316                                   "can't start unbound connection\n");
2317                 return -EPERM;
2318         }
2319
2320         if ((session->imm_data_en || !session->initial_r2t_en) &&
2321              session->first_burst > session->max_burst) {
2322                 iscsi_conn_printk(KERN_INFO, conn, "invalid burst lengths: "
2323                                   "first_burst %d max_burst %d\n",
2324                                   session->first_burst, session->max_burst);
2325                 return -EINVAL;
2326         }
2327
2328         if (conn->ping_timeout && !conn->recv_timeout) {
2329                 iscsi_conn_printk(KERN_ERR, conn, "invalid recv timeout of "
2330                                   "zero. Using 5 seconds\n.");
2331                 conn->recv_timeout = 5;
2332         }
2333
2334         if (conn->recv_timeout && !conn->ping_timeout) {
2335                 iscsi_conn_printk(KERN_ERR, conn, "invalid ping timeout of "
2336                                   "zero. Using 5 seconds.\n");
2337                 conn->ping_timeout = 5;
2338         }
2339
2340         spin_lock_bh(&session->lock);
2341         conn->c_stage = ISCSI_CONN_STARTED;
2342         session->state = ISCSI_STATE_LOGGED_IN;
2343         session->queued_cmdsn = session->cmdsn;
2344
2345         conn->last_recv = jiffies;
2346         conn->last_ping = jiffies;
2347         if (conn->recv_timeout && conn->ping_timeout)
2348                 mod_timer(&conn->transport_timer,
2349                           jiffies + (conn->recv_timeout * HZ));
2350
2351         switch(conn->stop_stage) {
2352         case STOP_CONN_RECOVER:
2353                 /*
2354                  * unblock eh_abort() if it is blocked. re-try all
2355                  * commands after successful recovery
2356                  */
2357                 conn->stop_stage = 0;
2358                 conn->tmf_state = TMF_INITIAL;
2359                 session->age++;
2360                 if (session->age == 16)
2361                         session->age = 0;
2362                 break;
2363         case STOP_CONN_TERM:
2364                 conn->stop_stage = 0;
2365                 break;
2366         default:
2367                 break;
2368         }
2369         spin_unlock_bh(&session->lock);
2370
2371         iscsi_unblock_session(session->cls_session);
2372         wake_up(&conn->ehwait);
2373         return 0;
2374 }
2375 EXPORT_SYMBOL_GPL(iscsi_conn_start);
2376
2377 static void
2378 flush_control_queues(struct iscsi_session *session, struct iscsi_conn *conn)
2379 {
2380         struct iscsi_task *task, *tmp;
2381
2382         /* handle pending */
2383         list_for_each_entry_safe(task, tmp, &conn->mgmtqueue, running) {
2384                 debug_scsi("flushing pending mgmt task itt 0x%x\n", task->itt);
2385                 /* release ref from prep task */
2386                 __iscsi_put_task(task);
2387         }
2388
2389         /* handle running */
2390         list_for_each_entry_safe(task, tmp, &conn->mgmt_run_list, running) {
2391                 debug_scsi("flushing running mgmt task itt 0x%x\n", task->itt);
2392                 /* release ref from prep task */
2393                 __iscsi_put_task(task);
2394         }
2395
2396         conn->task = NULL;
2397 }
2398
2399 static void iscsi_start_session_recovery(struct iscsi_session *session,
2400                                          struct iscsi_conn *conn, int flag)
2401 {
2402         int old_stop_stage;
2403
2404         del_timer_sync(&conn->transport_timer);
2405
2406         mutex_lock(&session->eh_mutex);
2407         spin_lock_bh(&session->lock);
2408         if (conn->stop_stage == STOP_CONN_TERM) {
2409                 spin_unlock_bh(&session->lock);
2410                 mutex_unlock(&session->eh_mutex);
2411                 return;
2412         }
2413
2414         /*
2415          * When this is called for the in_login state, we only want to clean
2416          * up the login task and connection. We do not need to block and set
2417          * the recovery state again
2418          */
2419         if (flag == STOP_CONN_TERM)
2420                 session->state = ISCSI_STATE_TERMINATE;
2421         else if (conn->stop_stage != STOP_CONN_RECOVER)
2422                 session->state = ISCSI_STATE_IN_RECOVERY;
2423
2424         old_stop_stage = conn->stop_stage;
2425         conn->stop_stage = flag;
2426         conn->c_stage = ISCSI_CONN_STOPPED;
2427         spin_unlock_bh(&session->lock);
2428
2429         iscsi_suspend_tx(conn);
2430         /*
2431          * for connection level recovery we should not calculate
2432          * header digest. conn->hdr_size used for optimization
2433          * in hdr_extract() and will be re-negotiated at
2434          * set_param() time.
2435          */
2436         if (flag == STOP_CONN_RECOVER) {
2437                 conn->hdrdgst_en = 0;
2438                 conn->datadgst_en = 0;
2439                 if (session->state == ISCSI_STATE_IN_RECOVERY &&
2440                     old_stop_stage != STOP_CONN_RECOVER) {
2441                         debug_scsi("blocking session\n");
2442                         iscsi_block_session(session->cls_session);
2443                 }
2444         }
2445
2446         /*
2447          * flush queues.
2448          */
2449         spin_lock_bh(&session->lock);
2450         if (flag == STOP_CONN_RECOVER)
2451                 fail_all_commands(conn, -1, DID_TRANSPORT_DISRUPTED);
2452         else
2453                 fail_all_commands(conn, -1, DID_ERROR);
2454         flush_control_queues(session, conn);
2455         spin_unlock_bh(&session->lock);
2456         mutex_unlock(&session->eh_mutex);
2457 }
2458
2459 void iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
2460 {
2461         struct iscsi_conn *conn = cls_conn->dd_data;
2462         struct iscsi_session *session = conn->session;
2463
2464         switch (flag) {
2465         case STOP_CONN_RECOVER:
2466         case STOP_CONN_TERM:
2467                 iscsi_start_session_recovery(session, conn, flag);
2468                 break;
2469         default:
2470                 iscsi_conn_printk(KERN_ERR, conn,
2471                                   "invalid stop flag %d\n", flag);
2472         }
2473 }
2474 EXPORT_SYMBOL_GPL(iscsi_conn_stop);
2475
2476 int iscsi_conn_bind(struct iscsi_cls_session *cls_session,
2477                     struct iscsi_cls_conn *cls_conn, int is_leading)
2478 {
2479         struct iscsi_session *session = cls_session->dd_data;
2480         struct iscsi_conn *conn = cls_conn->dd_data;
2481
2482         spin_lock_bh(&session->lock);
2483         if (is_leading)
2484                 session->leadconn = conn;
2485         spin_unlock_bh(&session->lock);
2486
2487         /*
2488          * Unblock xmitworker(), Login Phase will pass through.
2489          */
2490         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
2491         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
2492         return 0;
2493 }
2494 EXPORT_SYMBOL_GPL(iscsi_conn_bind);
2495
2496
2497 int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
2498                     enum iscsi_param param, char *buf, int buflen)
2499 {
2500         struct iscsi_conn *conn = cls_conn->dd_data;
2501         struct iscsi_session *session = conn->session;
2502         uint32_t value;
2503
2504         switch(param) {
2505         case ISCSI_PARAM_FAST_ABORT:
2506                 sscanf(buf, "%d", &session->fast_abort);
2507                 break;
2508         case ISCSI_PARAM_ABORT_TMO:
2509                 sscanf(buf, "%d", &session->abort_timeout);
2510                 break;
2511         case ISCSI_PARAM_LU_RESET_TMO:
2512                 sscanf(buf, "%d", &session->lu_reset_timeout);
2513                 break;
2514         case ISCSI_PARAM_PING_TMO:
2515                 sscanf(buf, "%d", &conn->ping_timeout);
2516                 break;
2517         case ISCSI_PARAM_RECV_TMO:
2518                 sscanf(buf, "%d", &conn->recv_timeout);
2519                 break;
2520         case ISCSI_PARAM_MAX_RECV_DLENGTH:
2521                 sscanf(buf, "%d", &conn->max_recv_dlength);
2522                 break;
2523         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
2524                 sscanf(buf, "%d", &conn->max_xmit_dlength);
2525                 break;
2526         case ISCSI_PARAM_HDRDGST_EN:
2527                 sscanf(buf, "%d", &conn->hdrdgst_en);
2528                 break;
2529         case ISCSI_PARAM_DATADGST_EN:
2530                 sscanf(buf, "%d", &conn->datadgst_en);
2531                 break;
2532         case ISCSI_PARAM_INITIAL_R2T_EN:
2533                 sscanf(buf, "%d", &session->initial_r2t_en);
2534                 break;
2535         case ISCSI_PARAM_MAX_R2T:
2536                 sscanf(buf, "%d", &session->max_r2t);
2537                 break;
2538         case ISCSI_PARAM_IMM_DATA_EN:
2539                 sscanf(buf, "%d", &session->imm_data_en);
2540                 break;
2541         case ISCSI_PARAM_FIRST_BURST:
2542                 sscanf(buf, "%d", &session->first_burst);
2543                 break;
2544         case ISCSI_PARAM_MAX_BURST:
2545                 sscanf(buf, "%d", &session->max_burst);
2546                 break;
2547         case ISCSI_PARAM_PDU_INORDER_EN:
2548                 sscanf(buf, "%d", &session->pdu_inorder_en);
2549                 break;
2550         case ISCSI_PARAM_DATASEQ_INORDER_EN:
2551                 sscanf(buf, "%d", &session->dataseq_inorder_en);
2552                 break;
2553         case ISCSI_PARAM_ERL:
2554                 sscanf(buf, "%d", &session->erl);
2555                 break;
2556         case ISCSI_PARAM_IFMARKER_EN:
2557                 sscanf(buf, "%d", &value);
2558                 BUG_ON(value);
2559                 break;
2560         case ISCSI_PARAM_OFMARKER_EN:
2561                 sscanf(buf, "%d", &value);
2562                 BUG_ON(value);
2563                 break;
2564         case ISCSI_PARAM_EXP_STATSN:
2565                 sscanf(buf, "%u", &conn->exp_statsn);
2566                 break;
2567         case ISCSI_PARAM_USERNAME:
2568                 kfree(session->username);
2569                 session->username = kstrdup(buf, GFP_KERNEL);
2570                 if (!session->username)
2571                         return -ENOMEM;
2572                 break;
2573         case ISCSI_PARAM_USERNAME_IN:
2574                 kfree(session->username_in);
2575                 session->username_in = kstrdup(buf, GFP_KERNEL);
2576                 if (!session->username_in)
2577                         return -ENOMEM;
2578                 break;
2579         case ISCSI_PARAM_PASSWORD:
2580                 kfree(session->password);
2581                 session->password = kstrdup(buf, GFP_KERNEL);
2582                 if (!session->password)
2583                         return -ENOMEM;
2584                 break;
2585         case ISCSI_PARAM_PASSWORD_IN:
2586                 kfree(session->password_in);
2587                 session->password_in = kstrdup(buf, GFP_KERNEL);
2588                 if (!session->password_in)
2589                         return -ENOMEM;
2590                 break;
2591         case ISCSI_PARAM_TARGET_NAME:
2592                 /* this should not change between logins */
2593                 if (session->targetname)
2594                         break;
2595
2596                 session->targetname = kstrdup(buf, GFP_KERNEL);
2597                 if (!session->targetname)
2598                         return -ENOMEM;
2599                 break;
2600         case ISCSI_PARAM_TPGT:
2601                 sscanf(buf, "%d", &session->tpgt);
2602                 break;
2603         case ISCSI_PARAM_PERSISTENT_PORT:
2604                 sscanf(buf, "%d", &conn->persistent_port);
2605                 break;
2606         case ISCSI_PARAM_PERSISTENT_ADDRESS:
2607                 /*
2608                  * this is the address returned in discovery so it should
2609                  * not change between logins.
2610                  */
2611                 if (conn->persistent_address)
2612                         break;
2613
2614                 conn->persistent_address = kstrdup(buf, GFP_KERNEL);
2615                 if (!conn->persistent_address)
2616                         return -ENOMEM;
2617                 break;
2618         case ISCSI_PARAM_IFACE_NAME:
2619                 if (!session->ifacename)
2620                         session->ifacename = kstrdup(buf, GFP_KERNEL);
2621                 break;
2622         case ISCSI_PARAM_INITIATOR_NAME:
2623                 if (!session->initiatorname)
2624                         session->initiatorname = kstrdup(buf, GFP_KERNEL);
2625                 break;
2626         default:
2627                 return -ENOSYS;
2628         }
2629
2630         return 0;
2631 }
2632 EXPORT_SYMBOL_GPL(iscsi_set_param);
2633
2634 int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
2635                             enum iscsi_param param, char *buf)
2636 {
2637         struct iscsi_session *session = cls_session->dd_data;
2638         int len;
2639
2640         switch(param) {
2641         case ISCSI_PARAM_FAST_ABORT:
2642                 len = sprintf(buf, "%d\n", session->fast_abort);
2643                 break;
2644         case ISCSI_PARAM_ABORT_TMO:
2645                 len = sprintf(buf, "%d\n", session->abort_timeout);
2646                 break;
2647         case ISCSI_PARAM_LU_RESET_TMO:
2648                 len = sprintf(buf, "%d\n", session->lu_reset_timeout);
2649                 break;
2650         case ISCSI_PARAM_INITIAL_R2T_EN:
2651                 len = sprintf(buf, "%d\n", session->initial_r2t_en);
2652                 break;
2653         case ISCSI_PARAM_MAX_R2T:
2654                 len = sprintf(buf, "%hu\n", session->max_r2t);
2655                 break;
2656         case ISCSI_PARAM_IMM_DATA_EN:
2657                 len = sprintf(buf, "%d\n", session->imm_data_en);
2658                 break;
2659         case ISCSI_PARAM_FIRST_BURST:
2660                 len = sprintf(buf, "%u\n", session->first_burst);
2661                 break;
2662         case ISCSI_PARAM_MAX_BURST:
2663                 len = sprintf(buf, "%u\n", session->max_burst);
2664                 break;
2665         case ISCSI_PARAM_PDU_INORDER_EN:
2666                 len = sprintf(buf, "%d\n", session->pdu_inorder_en);
2667                 break;
2668         case ISCSI_PARAM_DATASEQ_INORDER_EN:
2669                 len = sprintf(buf, "%d\n", session->dataseq_inorder_en);
2670                 break;
2671         case ISCSI_PARAM_ERL:
2672                 len = sprintf(buf, "%d\n", session->erl);
2673                 break;
2674         case ISCSI_PARAM_TARGET_NAME:
2675                 len = sprintf(buf, "%s\n", session->targetname);
2676                 break;
2677         case ISCSI_PARAM_TPGT:
2678                 len = sprintf(buf, "%d\n", session->tpgt);
2679                 break;
2680         case ISCSI_PARAM_USERNAME:
2681                 len = sprintf(buf, "%s\n", session->username);
2682                 break;
2683         case ISCSI_PARAM_USERNAME_IN:
2684                 len = sprintf(buf, "%s\n", session->username_in);
2685                 break;
2686         case ISCSI_PARAM_PASSWORD:
2687                 len = sprintf(buf, "%s\n", session->password);
2688                 break;
2689         case ISCSI_PARAM_PASSWORD_IN:
2690                 len = sprintf(buf, "%s\n", session->password_in);
2691                 break;
2692         case ISCSI_PARAM_IFACE_NAME:
2693                 len = sprintf(buf, "%s\n", session->ifacename);
2694                 break;
2695         case ISCSI_PARAM_INITIATOR_NAME:
2696                 if (!session->initiatorname)
2697                         len = sprintf(buf, "%s\n", "unknown");
2698                 else
2699                         len = sprintf(buf, "%s\n", session->initiatorname);
2700                 break;
2701         default:
2702                 return -ENOSYS;
2703         }
2704
2705         return len;
2706 }
2707 EXPORT_SYMBOL_GPL(iscsi_session_get_param);
2708
2709 int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
2710                          enum iscsi_param param, char *buf)
2711 {
2712         struct iscsi_conn *conn = cls_conn->dd_data;
2713         int len;
2714
2715         switch(param) {
2716         case ISCSI_PARAM_PING_TMO:
2717                 len = sprintf(buf, "%u\n", conn->ping_timeout);
2718                 break;
2719         case ISCSI_PARAM_RECV_TMO:
2720                 len = sprintf(buf, "%u\n", conn->recv_timeout);
2721                 break;
2722         case ISCSI_PARAM_MAX_RECV_DLENGTH:
2723                 len = sprintf(buf, "%u\n", conn->max_recv_dlength);
2724                 break;
2725         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
2726                 len = sprintf(buf, "%u\n", conn->max_xmit_dlength);
2727                 break;
2728         case ISCSI_PARAM_HDRDGST_EN:
2729                 len = sprintf(buf, "%d\n", conn->hdrdgst_en);
2730                 break;
2731         case ISCSI_PARAM_DATADGST_EN:
2732                 len = sprintf(buf, "%d\n", conn->datadgst_en);
2733                 break;
2734         case ISCSI_PARAM_IFMARKER_EN:
2735                 len = sprintf(buf, "%d\n", conn->ifmarker_en);
2736                 break;
2737         case ISCSI_PARAM_OFMARKER_EN:
2738                 len = sprintf(buf, "%d\n", conn->ofmarker_en);
2739                 break;
2740         case ISCSI_PARAM_EXP_STATSN:
2741                 len = sprintf(buf, "%u\n", conn->exp_statsn);
2742                 break;
2743         case ISCSI_PARAM_PERSISTENT_PORT:
2744                 len = sprintf(buf, "%d\n", conn->persistent_port);
2745                 break;
2746         case ISCSI_PARAM_PERSISTENT_ADDRESS:
2747                 len = sprintf(buf, "%s\n", conn->persistent_address);
2748                 break;
2749         default:
2750                 return -ENOSYS;
2751         }
2752
2753         return len;
2754 }
2755 EXPORT_SYMBOL_GPL(iscsi_conn_get_param);
2756
2757 int iscsi_host_get_param(struct Scsi_Host *shost, enum iscsi_host_param param,
2758                          char *buf)
2759 {
2760         struct iscsi_host *ihost = shost_priv(shost);
2761         int len;
2762
2763         switch (param) {
2764         case ISCSI_HOST_PARAM_NETDEV_NAME:
2765                 if (!ihost->netdev)
2766                         len = sprintf(buf, "%s\n", "default");
2767                 else
2768                         len = sprintf(buf, "%s\n", ihost->netdev);
2769                 break;
2770         case ISCSI_HOST_PARAM_HWADDRESS:
2771                 if (!ihost->hwaddress)
2772                         len = sprintf(buf, "%s\n", "default");
2773                 else
2774                         len = sprintf(buf, "%s\n", ihost->hwaddress);
2775                 break;
2776         case ISCSI_HOST_PARAM_INITIATOR_NAME:
2777                 if (!ihost->initiatorname)
2778                         len = sprintf(buf, "%s\n", "unknown");
2779                 else
2780                         len = sprintf(buf, "%s\n", ihost->initiatorname);
2781                 break;
2782         case ISCSI_HOST_PARAM_IPADDRESS:
2783                 if (!strlen(ihost->local_address))
2784                         len = sprintf(buf, "%s\n", "unknown");
2785                 else
2786                         len = sprintf(buf, "%s\n",
2787                                       ihost->local_address);
2788                 break;
2789         default:
2790                 return -ENOSYS;
2791         }
2792
2793         return len;
2794 }
2795 EXPORT_SYMBOL_GPL(iscsi_host_get_param);
2796
2797 int iscsi_host_set_param(struct Scsi_Host *shost, enum iscsi_host_param param,
2798                          char *buf, int buflen)
2799 {
2800         struct iscsi_host *ihost = shost_priv(shost);
2801
2802         switch (param) {
2803         case ISCSI_HOST_PARAM_NETDEV_NAME:
2804                 if (!ihost->netdev)
2805                         ihost->netdev = kstrdup(buf, GFP_KERNEL);
2806                 break;
2807         case ISCSI_HOST_PARAM_HWADDRESS:
2808                 if (!ihost->hwaddress)
2809                         ihost->hwaddress = kstrdup(buf, GFP_KERNEL);
2810                 break;
2811         case ISCSI_HOST_PARAM_INITIATOR_NAME:
2812                 if (!ihost->initiatorname)
2813                         ihost->initiatorname = kstrdup(buf, GFP_KERNEL);
2814                 break;
2815         default:
2816                 return -ENOSYS;
2817         }
2818
2819         return 0;
2820 }
2821 EXPORT_SYMBOL_GPL(iscsi_host_set_param);
2822
2823 MODULE_AUTHOR("Mike Christie");
2824 MODULE_DESCRIPTION("iSCSI library functions");
2825 MODULE_LICENSE("GPL");