git.oblomov.eu Git - linux-2.6/blob - drivers/scsi/libiscsi.c

   1 /*
   2  * iSCSI lib functions
   3  *
   4  * Copyright (C) 2006 Red Hat, Inc.  All rights reserved.
   5  * Copyright (C) 2004 - 2006 Mike Christie
   6  * Copyright (C) 2004 - 2005 Dmitry Yusupov
   7  * Copyright (C) 2004 - 2005 Alex Aizman
   8  * maintained by open-iscsi@googlegroups.com
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  23  */
  24 #include <linux/types.h>
  25 #include <linux/kfifo.h>
  26 #include <linux/delay.h>
  27 #include <linux/log2.h>
  28 #include <asm/unaligned.h>
  29 #include <net/tcp.h>
  30 #include <scsi/scsi_cmnd.h>
  31 #include <scsi/scsi_device.h>
  32 #include <scsi/scsi_eh.h>
  33 #include <scsi/scsi_tcq.h>
  34 #include <scsi/scsi_host.h>
  35 #include <scsi/scsi.h>
  36 #include <scsi/iscsi_proto.h>
  37 #include <scsi/scsi_transport.h>
  38 #include <scsi/scsi_transport_iscsi.h>
  39 #include <scsi/libiscsi.h>
  40
  41 /* Serial Number Arithmetic, 32 bits, less than, RFC1982 */
  42 #define SNA32_CHECK 2147483648UL
  43
  44 static int iscsi_sna_lt(u32 n1, u32 n2)
  45 {
  46         return n1 != n2 && ((n1 < n2 && (n2 - n1 < SNA32_CHECK)) ||
  47                             (n1 > n2 && (n2 - n1 < SNA32_CHECK)));
  48 }
  49
  50 /* Serial Number Arithmetic, 32 bits, less than, RFC1982 */
  51 static int iscsi_sna_lte(u32 n1, u32 n2)
  52 {
  53         return n1 == n2 || ((n1 < n2 && (n2 - n1 < SNA32_CHECK)) ||
  54                             (n1 > n2 && (n2 - n1 < SNA32_CHECK)));
  55 }
  56
  57 void
  58 iscsi_update_cmdsn(struct iscsi_session *session, struct iscsi_nopin *hdr)
  59 {
  60         uint32_t max_cmdsn = be32_to_cpu(hdr->max_cmdsn);
  61         uint32_t exp_cmdsn = be32_to_cpu(hdr->exp_cmdsn);
  62
  63         /*
  64          * standard specifies this check for when to update expected and
  65          * max sequence numbers
  66          */
  67         if (iscsi_sna_lt(max_cmdsn, exp_cmdsn - 1))
  68                 return;
  69
  70         if (exp_cmdsn != session->exp_cmdsn &&
  71             !iscsi_sna_lt(exp_cmdsn, session->exp_cmdsn))
  72                 session->exp_cmdsn = exp_cmdsn;
  73
  74         if (max_cmdsn != session->max_cmdsn &&
  75             !iscsi_sna_lt(max_cmdsn, session->max_cmdsn)) {
  76                 session->max_cmdsn = max_cmdsn;
  77                 /*
  78                  * if the window closed with IO queued, then kick the
  79                  * xmit thread
  80                  */
  81                 if (!list_empty(&session->leadconn->xmitqueue) ||
  82                     !list_empty(&session->leadconn->mgmtqueue)) {
  83                         if (!(session->tt->caps & CAP_DATA_PATH_OFFLOAD))
  84                                 scsi_queue_work(session->host,
  85                                                 &session->leadconn->xmitwork);
  86                 }
  87         }
  88 }
  89 EXPORT_SYMBOL_GPL(iscsi_update_cmdsn);
  90
  91 void iscsi_prep_unsolicit_data_pdu(struct iscsi_task *task,
  92                                    struct iscsi_data *hdr)
  93 {
  94         struct iscsi_conn *conn = task->conn;
  95
  96         memset(hdr, 0, sizeof(struct iscsi_data));
  97         hdr->ttt = cpu_to_be32(ISCSI_RESERVED_TAG);
  98         hdr->datasn = cpu_to_be32(task->unsol_datasn);
  99         task->unsol_datasn++;
 100         hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
 101         memcpy(hdr->lun, task->hdr->lun, sizeof(hdr->lun));
 102
 103         hdr->itt = task->hdr->itt;
 104         hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
 105         hdr->offset = cpu_to_be32(task->unsol_offset);
 106
 107         if (task->unsol_count > conn->max_xmit_dlength) {
 108                 hton24(hdr->dlength, conn->max_xmit_dlength);
 109                 task->data_count = conn->max_xmit_dlength;
 110                 task->unsol_offset += task->data_count;
 111                 hdr->flags = 0;
 112         } else {
 113                 hton24(hdr->dlength, task->unsol_count);
 114                 task->data_count = task->unsol_count;
 115                 hdr->flags = ISCSI_FLAG_CMD_FINAL;
 116         }
 117 }
 118 EXPORT_SYMBOL_GPL(iscsi_prep_unsolicit_data_pdu);
 119
 120 static int iscsi_add_hdr(struct iscsi_task *task, unsigned len)
 121 {
 122         unsigned exp_len = task->hdr_len + len;
 123
 124         if (exp_len > task->hdr_max) {
 125                 WARN_ON(1);
 126                 return -EINVAL;
 127         }
 128
 129         WARN_ON(len & (ISCSI_PAD_LEN - 1)); /* caller must pad the AHS */
 130         task->hdr_len = exp_len;
 131         return 0;
 132 }
 133
 134 /*
 135  * make an extended cdb AHS
 136  */
 137 static int iscsi_prep_ecdb_ahs(struct iscsi_task *task)
 138 {
 139         struct scsi_cmnd *cmd = task->sc;
 140         unsigned rlen, pad_len;
 141         unsigned short ahslength;
 142         struct iscsi_ecdb_ahdr *ecdb_ahdr;
 143         int rc;
 144
 145         ecdb_ahdr = iscsi_next_hdr(task);
 146         rlen = cmd->cmd_len - ISCSI_CDB_SIZE;
 147
 148         BUG_ON(rlen > sizeof(ecdb_ahdr->ecdb));
 149         ahslength = rlen + sizeof(ecdb_ahdr->reserved);
 150
 151         pad_len = iscsi_padding(rlen);
 152
 153         rc = iscsi_add_hdr(task, sizeof(ecdb_ahdr->ahslength) +
 154                            sizeof(ecdb_ahdr->ahstype) + ahslength + pad_len);
 155         if (rc)
 156                 return rc;
 157
 158         if (pad_len)
 159                 memset(&ecdb_ahdr->ecdb[rlen], 0, pad_len);
 160
 161         ecdb_ahdr->ahslength = cpu_to_be16(ahslength);
 162         ecdb_ahdr->ahstype = ISCSI_AHSTYPE_CDB;
 163         ecdb_ahdr->reserved = 0;
 164         memcpy(ecdb_ahdr->ecdb, cmd->cmnd + ISCSI_CDB_SIZE, rlen);
 165
 166         debug_scsi("iscsi_prep_ecdb_ahs: varlen_cdb_len %d "
 167                    "rlen %d pad_len %d ahs_length %d iscsi_headers_size %u\n",
 168                    cmd->cmd_len, rlen, pad_len, ahslength, task->hdr_len);
 169
 170         return 0;
 171 }
 172
 173 static int iscsi_prep_bidi_ahs(struct iscsi_task *task)
 174 {
 175         struct scsi_cmnd *sc = task->sc;
 176         struct iscsi_rlength_ahdr *rlen_ahdr;
 177         int rc;
 178
 179         rlen_ahdr = iscsi_next_hdr(task);
 180         rc = iscsi_add_hdr(task, sizeof(*rlen_ahdr));
 181         if (rc)
 182                 return rc;
 183
 184         rlen_ahdr->ahslength =
 185                 cpu_to_be16(sizeof(rlen_ahdr->read_length) +
 186                                                   sizeof(rlen_ahdr->reserved));
 187         rlen_ahdr->ahstype = ISCSI_AHSTYPE_RLENGTH;
 188         rlen_ahdr->reserved = 0;
 189         rlen_ahdr->read_length = cpu_to_be32(scsi_in(sc)->length);
 190
 191         debug_scsi("bidi-in rlen_ahdr->read_length(%d) "
 192                    "rlen_ahdr->ahslength(%d)\n",
 193                    be32_to_cpu(rlen_ahdr->read_length),
 194                    be16_to_cpu(rlen_ahdr->ahslength));
 195         return 0;
 196 }
 197
 198 /**
 199  * iscsi_prep_scsi_cmd_pdu - prep iscsi scsi cmd pdu
 200  * @task: iscsi task
 201  *
 202  * Prep basic iSCSI PDU fields for a scsi cmd pdu. The LLD should set
 203  * fields like dlength or final based on how much data it sends
 204  */
 205 static int iscsi_prep_scsi_cmd_pdu(struct iscsi_task *task)
 206 {
 207         struct iscsi_conn *conn = task->conn;
 208         struct iscsi_session *session = conn->session;
 209         struct iscsi_cmd *hdr = task->hdr;
 210         struct scsi_cmnd *sc = task->sc;
 211         unsigned hdrlength, cmd_len;
 212         int rc;
 213
 214         task->hdr_len = 0;
 215         rc = iscsi_add_hdr(task, sizeof(*hdr));
 216         if (rc)
 217                 return rc;
 218         hdr->opcode = ISCSI_OP_SCSI_CMD;
 219         hdr->flags = ISCSI_ATTR_SIMPLE;
 220         int_to_scsilun(sc->device->lun, (struct scsi_lun *)hdr->lun);
 221         hdr->itt = build_itt(task->itt, session->age);
 222         hdr->cmdsn = cpu_to_be32(session->cmdsn);
 223         session->cmdsn++;
 224         hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
 225         cmd_len = sc->cmd_len;
 226         if (cmd_len < ISCSI_CDB_SIZE)
 227                 memset(&hdr->cdb[cmd_len], 0, ISCSI_CDB_SIZE - cmd_len);
 228         else if (cmd_len > ISCSI_CDB_SIZE) {
 229                 rc = iscsi_prep_ecdb_ahs(task);
 230                 if (rc)
 231                         return rc;
 232                 cmd_len = ISCSI_CDB_SIZE;
 233         }
 234         memcpy(hdr->cdb, sc->cmnd, cmd_len);
 235
 236         task->imm_count = 0;
 237         if (scsi_bidi_cmnd(sc)) {
 238                 hdr->flags |= ISCSI_FLAG_CMD_READ;
 239                 rc = iscsi_prep_bidi_ahs(task);
 240                 if (rc)
 241                         return rc;
 242         }
 243         if (sc->sc_data_direction == DMA_TO_DEVICE) {
 244                 unsigned out_len = scsi_out(sc)->length;
 245                 hdr->data_length = cpu_to_be32(out_len);
 246                 hdr->flags |= ISCSI_FLAG_CMD_WRITE;
 247                 /*
 248                  * Write counters:
 249                  *
 250                  *      imm_count       bytes to be sent right after
 251                  *                      SCSI PDU Header
 252                  *
 253                  *      unsol_count     bytes(as Data-Out) to be sent
 254                  *                      without R2T ack right after
 255                  *                      immediate data
 256                  *
 257                  *      r2t_data_count  bytes to be sent via R2T ack's
 258                  *
 259                  *      pad_count       bytes to be sent as zero-padding
 260                  */
 261                 task->unsol_count = 0;
 262                 task->unsol_offset = 0;
 263                 task->unsol_datasn = 0;
 264
 265                 if (session->imm_data_en) {
 266                         if (out_len >= session->first_burst)
 267                                 task->imm_count = min(session->first_burst,
 268                                                         conn->max_xmit_dlength);
 269                         else
 270                                 task->imm_count = min(out_len,
 271                                                         conn->max_xmit_dlength);
 272                         hton24(hdr->dlength, task->imm_count);
 273                 } else
 274                         zero_data(hdr->dlength);
 275
 276                 if (!session->initial_r2t_en) {
 277                         task->unsol_count = min(session->first_burst, out_len)
 278                                                              - task->imm_count;
 279                         task->unsol_offset = task->imm_count;
 280                 }
 281
 282                 if (!task->unsol_count)
 283                         /* No unsolicit Data-Out's */
 284                         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
 285         } else {
 286                 hdr->flags |= ISCSI_FLAG_CMD_FINAL;
 287                 zero_data(hdr->dlength);
 288                 hdr->data_length = cpu_to_be32(scsi_in(sc)->length);
 289
 290                 if (sc->sc_data_direction == DMA_FROM_DEVICE)
 291                         hdr->flags |= ISCSI_FLAG_CMD_READ;
 292         }
 293
 294         /* calculate size of additional header segments (AHSs) */
 295         hdrlength = task->hdr_len - sizeof(*hdr);
 296
 297         WARN_ON(hdrlength & (ISCSI_PAD_LEN-1));
 298         hdrlength /= ISCSI_PAD_LEN;
 299
 300         WARN_ON(hdrlength >= 256);
 301         hdr->hlength = hdrlength & 0xFF;
 302
 303         if (conn->session->tt->init_task &&
 304             conn->session->tt->init_task(task))
 305                 return -EIO;
 306
 307         task->state = ISCSI_TASK_RUNNING;
 308         list_move_tail(&task->running, &conn->run_list);
 309
 310         conn->scsicmd_pdus_cnt++;
 311         debug_scsi("iscsi prep [%s cid %d sc %p cdb 0x%x itt 0x%x len %d "
 312                    "bidi_len %d cmdsn %d win %d]\n", scsi_bidi_cmnd(sc) ?
 313                    "bidirectional" : sc->sc_data_direction == DMA_TO_DEVICE ?
 314                    "write" : "read", conn->id, sc, sc->cmnd[0], task->itt,
 315                    scsi_bufflen(sc),
 316                    scsi_bidi_cmnd(sc) ? scsi_in(sc)->length : 0,
 317                    session->cmdsn, session->max_cmdsn - session->exp_cmdsn + 1);
 318         return 0;
 319 }
 320
 321 /**
 322  * iscsi_complete_command - finish a task
 323  * @task: iscsi cmd task
 324  *
 325  * Must be called with session lock.
 326  * This function returns the scsi command to scsi-ml or cleans
 327  * up mgmt tasks then returns the task to the pool.
 328  */
 329 static void iscsi_complete_command(struct iscsi_task *task)
 330 {
 331         struct iscsi_conn *conn = task->conn;
 332         struct iscsi_session *session = conn->session;
 333         struct scsi_cmnd *sc = task->sc;
 334
 335         list_del_init(&task->running);
 336         task->state = ISCSI_TASK_COMPLETED;
 337         task->sc = NULL;
 338
 339         if (conn->task == task)
 340                 conn->task = NULL;
 341         /*
 342          * login task is preallocated so do not free
 343          */
 344         if (conn->login_task == task)
 345                 return;
 346
 347         __kfifo_put(session->cmdpool.queue, (void*)&task, sizeof(void*));
 348
 349         if (conn->ping_task == task)
 350                 conn->ping_task = NULL;
 351
 352         if (sc) {
 353                 task->sc = NULL;
 354                 /* SCSI eh reuses commands to verify us */
 355                 sc->SCp.ptr = NULL;
 356                 /*
 357                  * queue command may call this to free the task, but
 358                  * not have setup the sc callback
 359                  */
 360                 if (sc->scsi_done)
 361                         sc->scsi_done(sc);
 362         }
 363 }
 364
 365 void __iscsi_get_task(struct iscsi_task *task)
 366 {
 367         atomic_inc(&task->refcount);
 368 }
 369 EXPORT_SYMBOL_GPL(__iscsi_get_task);
 370
 371 static void __iscsi_put_task(struct iscsi_task *task)
 372 {
 373         if (atomic_dec_and_test(&task->refcount))
 374                 iscsi_complete_command(task);
 375 }
 376
 377 void iscsi_put_task(struct iscsi_task *task)
 378 {
 379         struct iscsi_session *session = task->conn->session;
 380
 381         spin_lock_bh(&session->lock);
 382         __iscsi_put_task(task);
 383         spin_unlock_bh(&session->lock);
 384 }
 385 EXPORT_SYMBOL_GPL(iscsi_put_task);
 386
 387 /*
 388  * session lock must be held
 389  */
 390 static void fail_command(struct iscsi_conn *conn, struct iscsi_task *task,
 391                          int err)
 392 {
 393         struct scsi_cmnd *sc;
 394
 395         sc = task->sc;
 396         if (!sc)
 397                 return;
 398
 399         if (task->state == ISCSI_TASK_PENDING)
 400                 /*
 401                  * cmd never made it to the xmit thread, so we should not count
 402                  * the cmd in the sequencing
 403                  */
 404                 conn->session->queued_cmdsn--;
 405         else
 406                 conn->session->tt->cleanup_task(conn, task);
 407         /*
 408          * Check if cleanup_task dropped the lock and the command completed,
 409          */
 410         if (!task->sc)
 411                 return;
 412
 413         sc->result = err;
 414         if (!scsi_bidi_cmnd(sc))
 415                 scsi_set_resid(sc, scsi_bufflen(sc));
 416         else {
 417                 scsi_out(sc)->resid = scsi_out(sc)->length;
 418                 scsi_in(sc)->resid = scsi_in(sc)->length;
 419         }
 420
 421         if (conn->task == task)
 422                 conn->task = NULL;
 423         /* release ref from queuecommand */
 424         __iscsi_put_task(task);
 425 }
 426
 427 static int iscsi_prep_mgmt_task(struct iscsi_conn *conn,
 428                                 struct iscsi_task *task)
 429 {
 430         struct iscsi_session *session = conn->session;
 431         struct iscsi_hdr *hdr = (struct iscsi_hdr *)task->hdr;
 432         struct iscsi_nopout *nop = (struct iscsi_nopout *)hdr;
 433
 434         if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
 435                 return -ENOTCONN;
 436
 437         if (hdr->opcode != (ISCSI_OP_LOGIN | ISCSI_OP_IMMEDIATE) &&
 438             hdr->opcode != (ISCSI_OP_TEXT | ISCSI_OP_IMMEDIATE))
 439                 nop->exp_statsn = cpu_to_be32(conn->exp_statsn);
 440         /*
 441          * pre-format CmdSN for outgoing PDU.
 442          */
 443         nop->cmdsn = cpu_to_be32(session->cmdsn);
 444         if (hdr->itt != RESERVED_ITT) {
 445                 hdr->itt = build_itt(task->itt, session->age);
 446                 /*
 447                  * TODO: We always use immediate, so we never hit this.
 448                  * If we start to send tmfs or nops as non-immediate then
 449                  * we should start checking the cmdsn numbers for mgmt tasks.
 450                  */
 451                 if (conn->c_stage == ISCSI_CONN_STARTED &&
 452                     !(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
 453                         session->queued_cmdsn++;
 454                         session->cmdsn++;
 455                 }
 456         }
 457
 458         if (session->tt->init_task)
 459                 session->tt->init_task(task);
 460
 461         if ((hdr->opcode & ISCSI_OPCODE_MASK) == ISCSI_OP_LOGOUT)
 462                 session->state = ISCSI_STATE_LOGGING_OUT;
 463
 464         list_move_tail(&task->running, &conn->mgmt_run_list);
 465         debug_scsi("mgmtpdu [op 0x%x hdr->itt 0x%x datalen %d]\n",
 466                    hdr->opcode & ISCSI_OPCODE_MASK, hdr->itt,
 467                    task->data_count);
 468         return 0;
 469 }
 470
 471 static struct iscsi_task *
 472 __iscsi_conn_send_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 473                       char *data, uint32_t data_size)
 474 {
 475         struct iscsi_session *session = conn->session;
 476         struct iscsi_task *task;
 477
 478         if (session->state == ISCSI_STATE_TERMINATE)
 479                 return NULL;
 480
 481         if (hdr->opcode == (ISCSI_OP_LOGIN | ISCSI_OP_IMMEDIATE) ||
 482             hdr->opcode == (ISCSI_OP_TEXT | ISCSI_OP_IMMEDIATE))
 483                 /*
 484                  * Login and Text are sent serially, in
 485                  * request-followed-by-response sequence.
 486                  * Same task can be used. Same ITT must be used.
 487                  * Note that login_task is preallocated at conn_create().
 488                  */
 489                 task = conn->login_task;
 490         else {
 491                 BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
 492                 BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);
 493
 494                 if (!__kfifo_get(session->cmdpool.queue,
 495                                  (void*)&task, sizeof(void*)))
 496                         return NULL;
 497
 498                 if ((hdr->opcode == (ISCSI_OP_NOOP_OUT | ISCSI_OP_IMMEDIATE)) &&
 499                      hdr->ttt == RESERVED_ITT) {
 500                         conn->ping_task = task;
 501                         conn->last_ping = jiffies;
 502                 }
 503         }
 504         /*
 505          * released in complete pdu for task we expect a response for, and
 506          * released by the lld when it has transmitted the task for
 507          * pdus we do not expect a response for.
 508          */
 509         atomic_set(&task->refcount, 1);
 510         task->conn = conn;
 511         task->sc = NULL;
 512
 513         if (data_size) {
 514                 memcpy(task->data, data, data_size);
 515                 task->data_count = data_size;
 516         } else
 517                 task->data_count = 0;
 518
 519         memcpy(task->hdr, hdr, sizeof(struct iscsi_hdr));
 520         INIT_LIST_HEAD(&task->running);
 521         list_add_tail(&task->running, &conn->mgmtqueue);
 522
 523         if (session->tt->caps & CAP_DATA_PATH_OFFLOAD) {
 524                 if (iscsi_prep_mgmt_task(conn, task)) {
 525                         __iscsi_put_task(task);
 526                         return NULL;
 527                 }
 528
 529                 if (session->tt->xmit_task(task))
 530                         task = NULL;
 531
 532         } else
 533                 scsi_queue_work(conn->session->host, &conn->xmitwork);
 534
 535         return task;
 536 }
 537
 538 int iscsi_conn_send_pdu(struct iscsi_cls_conn *cls_conn, struct iscsi_hdr *hdr,
 539                         char *data, uint32_t data_size)
 540 {
 541         struct iscsi_conn *conn = cls_conn->dd_data;
 542         struct iscsi_session *session = conn->session;
 543         int err = 0;
 544
 545         spin_lock_bh(&session->lock);
 546         if (!__iscsi_conn_send_pdu(conn, hdr, data, data_size))
 547                 err = -EPERM;
 548         spin_unlock_bh(&session->lock);
 549         return err;
 550 }
 551 EXPORT_SYMBOL_GPL(iscsi_conn_send_pdu);
 552
 553 /**
 554  * iscsi_cmd_rsp - SCSI Command Response processing
 555  * @conn: iscsi connection
 556  * @hdr: iscsi header
 557  * @task: scsi command task
 558  * @data: cmd data buffer
 559  * @datalen: len of buffer
 560  *
 561  * iscsi_cmd_rsp sets up the scsi_cmnd fields based on the PDU and
 562  * then completes the command and task.
 563  **/
 564 static void iscsi_scsi_cmd_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 565                                struct iscsi_task *task, char *data,
 566                                int datalen)
 567 {
 568         struct iscsi_cmd_rsp *rhdr = (struct iscsi_cmd_rsp *)hdr;
 569         struct iscsi_session *session = conn->session;
 570         struct scsi_cmnd *sc = task->sc;
 571
 572         iscsi_update_cmdsn(session, (struct iscsi_nopin*)rhdr);
 573         conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 574
 575         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 576
 577         if (rhdr->response != ISCSI_STATUS_CMD_COMPLETED) {
 578                 sc->result = DID_ERROR << 16;
 579                 goto out;
 580         }
 581
 582         if (rhdr->cmd_status == SAM_STAT_CHECK_CONDITION) {
 583                 uint16_t senselen;
 584
 585                 if (datalen < 2) {
 586 invalid_datalen:
 587                         iscsi_conn_printk(KERN_ERR,  conn,
 588                                          "Got CHECK_CONDITION but invalid data "
 589                                          "buffer size of %d\n", datalen);
 590                         sc->result = DID_BAD_TARGET << 16;
 591                         goto out;
 592                 }
 593
 594                 senselen = get_unaligned_be16(data);
 595                 if (datalen < senselen)
 596                         goto invalid_datalen;
 597
 598                 memcpy(sc->sense_buffer, data + 2,
 599                        min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
 600                 debug_scsi("copied %d bytes of sense\n",
 601                            min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
 602         }
 603
 604         if (rhdr->flags & (ISCSI_FLAG_CMD_BIDI_UNDERFLOW |
 605                            ISCSI_FLAG_CMD_BIDI_OVERFLOW)) {
 606                 int res_count = be32_to_cpu(rhdr->bi_residual_count);
 607
 608                 if (scsi_bidi_cmnd(sc) && res_count > 0 &&
 609                                 (rhdr->flags & ISCSI_FLAG_CMD_BIDI_OVERFLOW ||
 610                                  res_count <= scsi_in(sc)->length))
 611                         scsi_in(sc)->resid = res_count;
 612                 else
 613                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 614         }
 615
 616         if (rhdr->flags & (ISCSI_FLAG_CMD_UNDERFLOW |
 617                            ISCSI_FLAG_CMD_OVERFLOW)) {
 618                 int res_count = be32_to_cpu(rhdr->residual_count);
 619
 620                 if (res_count > 0 &&
 621                     (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
 622                      res_count <= scsi_bufflen(sc)))
 623                         /* write side for bidi or uni-io set_resid */
 624                         scsi_set_resid(sc, res_count);
 625                 else
 626                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 627         }
 628 out:
 629         debug_scsi("done [sc %lx res %d itt 0x%x]\n",
 630                    (long)sc, sc->result, task->itt);
 631         conn->scsirsp_pdus_cnt++;
 632
 633         __iscsi_put_task(task);
 634 }
 635
 636 /**
 637  * iscsi_data_in_rsp - SCSI Data-In Response processing
 638  * @conn: iscsi connection
 639  * @hdr:  iscsi pdu
 640  * @task: scsi command task
 641  **/
 642 static void
 643 iscsi_data_in_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 644                   struct iscsi_task *task)
 645 {
 646         struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)hdr;
 647         struct scsi_cmnd *sc = task->sc;
 648
 649         if (!(rhdr->flags & ISCSI_FLAG_DATA_STATUS))
 650                 return;
 651
 652         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 653         conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 654         if (rhdr->flags & (ISCSI_FLAG_DATA_UNDERFLOW |
 655                            ISCSI_FLAG_DATA_OVERFLOW)) {
 656                 int res_count = be32_to_cpu(rhdr->residual_count);
 657
 658                 if (res_count > 0 &&
 659                     (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
 660                      res_count <= scsi_in(sc)->length))
 661                         scsi_in(sc)->resid = res_count;
 662                 else
 663                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 664         }
 665
 666         conn->scsirsp_pdus_cnt++;
 667         __iscsi_put_task(task);
 668 }
 669
 670 static void iscsi_tmf_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
 671 {
 672         struct iscsi_tm_rsp *tmf = (struct iscsi_tm_rsp *)hdr;
 673
 674         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 675         conn->tmfrsp_pdus_cnt++;
 676
 677         if (conn->tmf_state != TMF_QUEUED)
 678                 return;
 679
 680         if (tmf->response == ISCSI_TMF_RSP_COMPLETE)
 681                 conn->tmf_state = TMF_SUCCESS;
 682         else if (tmf->response == ISCSI_TMF_RSP_NO_TASK)
 683                 conn->tmf_state = TMF_NOT_FOUND;
 684         else
 685                 conn->tmf_state = TMF_FAILED;
 686         wake_up(&conn->ehwait);
 687 }
 688
 689 static void iscsi_send_nopout(struct iscsi_conn *conn, struct iscsi_nopin *rhdr)
 690 {
 691         struct iscsi_nopout hdr;
 692         struct iscsi_task *task;
 693
 694         if (!rhdr && conn->ping_task)
 695                 return;
 696
 697         memset(&hdr, 0, sizeof(struct iscsi_nopout));
 698         hdr.opcode = ISCSI_OP_NOOP_OUT | ISCSI_OP_IMMEDIATE;
 699         hdr.flags = ISCSI_FLAG_CMD_FINAL;
 700
 701         if (rhdr) {
 702                 memcpy(hdr.lun, rhdr->lun, 8);
 703                 hdr.ttt = rhdr->ttt;
 704                 hdr.itt = RESERVED_ITT;
 705         } else
 706                 hdr.ttt = RESERVED_ITT;
 707
 708         task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)&hdr, NULL, 0);
 709         if (!task)
 710                 iscsi_conn_printk(KERN_ERR, conn, "Could not send nopout\n");
 711 }
 712
 713 static int iscsi_handle_reject(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 714                                char *data, int datalen)
 715 {
 716         struct iscsi_reject *reject = (struct iscsi_reject *)hdr;
 717         struct iscsi_hdr rejected_pdu;
 718         uint32_t itt;
 719
 720         conn->exp_statsn = be32_to_cpu(reject->statsn) + 1;
 721
 722         if (reject->reason == ISCSI_REASON_DATA_DIGEST_ERROR) {
 723                 if (ntoh24(reject->dlength) > datalen)
 724                         return ISCSI_ERR_PROTO;
 725
 726                 if (ntoh24(reject->dlength) >= sizeof(struct iscsi_hdr)) {
 727                         memcpy(&rejected_pdu, data, sizeof(struct iscsi_hdr));
 728                         itt = get_itt(rejected_pdu.itt);
 729                         iscsi_conn_printk(KERN_ERR, conn,
 730                                           "itt 0x%x had pdu (op 0x%x) rejected "
 731                                           "due to DataDigest error.\n", itt,
 732                                           rejected_pdu.opcode);
 733                 }
 734         }
 735         return 0;
 736 }
 737
 738 /**
 739  * iscsi_itt_to_task - look up task by itt
 740  * @conn: iscsi connection
 741  * @itt: itt
 742  *
 743  * This should be used for mgmt tasks like login and nops, or if
 744  * the LDD's itt space does not include the session age.
 745  *
 746  * The session lock must be held.
 747  */
 748 static struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *conn, itt_t itt)
 749 {
 750         struct iscsi_session *session = conn->session;
 751         uint32_t i;
 752
 753         if (itt == RESERVED_ITT)
 754                 return NULL;
 755
 756         i = get_itt(itt);
 757         if (i >= session->cmds_max)
 758                 return NULL;
 759
 760         return session->cmds[i];
 761 }
 762
 763 /**
 764  * __iscsi_complete_pdu - complete pdu
 765  * @conn: iscsi conn
 766  * @hdr: iscsi header
 767  * @data: data buffer
 768  * @datalen: len of data buffer
 769  *
 770  * Completes pdu processing by freeing any resources allocated at
 771  * queuecommand or send generic. session lock must be held and verify
 772  * itt must have been called.
 773  */
 774 int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 775                          char *data, int datalen)
 776 {
 777         struct iscsi_session *session = conn->session;
 778         int opcode = hdr->opcode & ISCSI_OPCODE_MASK, rc = 0;
 779         struct iscsi_task *task;
 780         uint32_t itt;
 781
 782         conn->last_recv = jiffies;
 783         rc = iscsi_verify_itt(conn, hdr->itt);
 784         if (rc)
 785                 return rc;
 786
 787         if (hdr->itt != RESERVED_ITT)
 788                 itt = get_itt(hdr->itt);
 789         else
 790                 itt = ~0U;
 791
 792         debug_scsi("[op 0x%x cid %d itt 0x%x len %d]\n",
 793                    opcode, conn->id, itt, datalen);
 794
 795         if (itt == ~0U) {
 796                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
 797
 798                 switch(opcode) {
 799                 case ISCSI_OP_NOOP_IN:
 800                         if (datalen) {
 801                                 rc = ISCSI_ERR_PROTO;
 802                                 break;
 803                         }
 804
 805                         if (hdr->ttt == cpu_to_be32(ISCSI_RESERVED_TAG))
 806                                 break;
 807
 808                         iscsi_send_nopout(conn, (struct iscsi_nopin*)hdr);
 809                         break;
 810                 case ISCSI_OP_REJECT:
 811                         rc = iscsi_handle_reject(conn, hdr, data, datalen);
 812                         break;
 813                 case ISCSI_OP_ASYNC_EVENT:
 814                         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 815                         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
 816                                 rc = ISCSI_ERR_CONN_FAILED;
 817                         break;
 818                 default:
 819                         rc = ISCSI_ERR_BAD_OPCODE;
 820                         break;
 821                 }
 822                 goto out;
 823         }
 824
 825         switch(opcode) {
 826         case ISCSI_OP_SCSI_CMD_RSP:
 827         case ISCSI_OP_SCSI_DATA_IN:
 828                 task = iscsi_itt_to_ctask(conn, hdr->itt);
 829                 if (!task)
 830                         return ISCSI_ERR_BAD_ITT;
 831                 break;
 832         case ISCSI_OP_R2T:
 833                 /*
 834                  * LLD handles R2Ts if they need to.
 835                  */
 836                 return 0;
 837         case ISCSI_OP_LOGOUT_RSP:
 838         case ISCSI_OP_LOGIN_RSP:
 839         case ISCSI_OP_TEXT_RSP:
 840         case ISCSI_OP_SCSI_TMFUNC_RSP:
 841         case ISCSI_OP_NOOP_IN:
 842                 task = iscsi_itt_to_task(conn, hdr->itt);
 843                 if (!task)
 844                         return ISCSI_ERR_BAD_ITT;
 845                 break;
 846         default:
 847                 return ISCSI_ERR_BAD_OPCODE;
 848         }
 849
 850         switch(opcode) {
 851         case ISCSI_OP_SCSI_CMD_RSP:
 852                 iscsi_scsi_cmd_rsp(conn, hdr, task, data, datalen);
 853                 break;
 854         case ISCSI_OP_SCSI_DATA_IN:
 855                 iscsi_data_in_rsp(conn, hdr, task);
 856                 break;
 857         case ISCSI_OP_LOGOUT_RSP:
 858                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
 859                 if (datalen) {
 860                         rc = ISCSI_ERR_PROTO;
 861                         break;
 862                 }
 863                 conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 864                 goto recv_pdu;
 865         case ISCSI_OP_LOGIN_RSP:
 866         case ISCSI_OP_TEXT_RSP:
 867                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
 868                 /*
 869                  * login related PDU's exp_statsn is handled in
 870                  * userspace
 871                  */
 872                 goto recv_pdu;
 873         case ISCSI_OP_SCSI_TMFUNC_RSP:
 874                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
 875                 if (datalen) {
 876                         rc = ISCSI_ERR_PROTO;
 877                         break;
 878                 }
 879
 880                 iscsi_tmf_rsp(conn, hdr);
 881                 __iscsi_put_task(task);
 882                 break;
 883         case ISCSI_OP_NOOP_IN:
 884                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
 885                 if (hdr->ttt != cpu_to_be32(ISCSI_RESERVED_TAG) || datalen) {
 886                         rc = ISCSI_ERR_PROTO;
 887                         break;
 888                 }
 889                 conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 890
 891                 if (conn->ping_task != task)
 892                         /*
 893                          * If this is not in response to one of our
 894                          * nops then it must be from userspace.
 895                          */
 896                         goto recv_pdu;
 897
 898                 mod_timer(&conn->transport_timer, jiffies + conn->recv_timeout);
 899                 __iscsi_put_task(task);
 900                 break;
 901         default:
 902                 rc = ISCSI_ERR_BAD_OPCODE;
 903                 break;
 904         }
 905
 906 out:
 907         return rc;
 908 recv_pdu:
 909         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
 910                 rc = ISCSI_ERR_CONN_FAILED;
 911         __iscsi_put_task(task);
 912         return rc;
 913 }
 914 EXPORT_SYMBOL_GPL(__iscsi_complete_pdu);
 915
 916 int iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 917                        char *data, int datalen)
 918 {
 919         int rc;
 920
 921         spin_lock(&conn->session->lock);
 922         rc = __iscsi_complete_pdu(conn, hdr, data, datalen);
 923         spin_unlock(&conn->session->lock);
 924         return rc;
 925 }
 926 EXPORT_SYMBOL_GPL(iscsi_complete_pdu);
 927
 928 int iscsi_verify_itt(struct iscsi_conn *conn, itt_t itt)
 929 {
 930         struct iscsi_session *session = conn->session;
 931         uint32_t i;
 932
 933         if (itt == RESERVED_ITT)
 934                 return 0;
 935
 936         if (((__force u32)itt & ISCSI_AGE_MASK) !=
 937             (session->age << ISCSI_AGE_SHIFT)) {
 938                 iscsi_conn_printk(KERN_ERR, conn,
 939                                   "received itt %x expected session age (%x)\n",
 940                                   (__force u32)itt, session->age);
 941                 return ISCSI_ERR_BAD_ITT;
 942         }
 943
 944         i = get_itt(itt);
 945         if (i >= session->cmds_max) {
 946                 iscsi_conn_printk(KERN_ERR, conn,
 947                                   "received invalid itt index %u (max cmds "
 948                                    "%u.\n", i, session->cmds_max);
 949                 return ISCSI_ERR_BAD_ITT;
 950         }
 951         return 0;
 952 }
 953 EXPORT_SYMBOL_GPL(iscsi_verify_itt);
 954
 955 /**
 956  * iscsi_itt_to_ctask - look up ctask by itt
 957  * @conn: iscsi connection
 958  * @itt: itt
 959  *
 960  * This should be used for cmd tasks.
 961  *
 962  * The session lock must be held.
 963  */
 964 struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *conn, itt_t itt)
 965 {
 966         struct iscsi_task *task;
 967
 968         if (iscsi_verify_itt(conn, itt))
 969                 return NULL;
 970
 971         task = iscsi_itt_to_task(conn, itt);
 972         if (!task || !task->sc)
 973                 return NULL;
 974
 975         if (task->sc->SCp.phase != conn->session->age) {
 976                 iscsi_session_printk(KERN_ERR, conn->session,
 977                                   "task's session age %d, expected %d\n",
 978                                   task->sc->SCp.phase, conn->session->age);
 979                 return NULL;
 980         }
 981
 982         return task;
 983 }
 984 EXPORT_SYMBOL_GPL(iscsi_itt_to_ctask);
 985
 986 void iscsi_session_failure(struct iscsi_cls_session *cls_session,
 987                            enum iscsi_err err)
 988 {
 989         struct iscsi_session *session = cls_session->dd_data;
 990         struct iscsi_conn *conn;
 991         struct device *dev;
 992         unsigned long flags;
 993
 994         spin_lock_irqsave(&session->lock, flags);
 995         conn = session->leadconn;
 996         if (session->state == ISCSI_STATE_TERMINATE || !conn) {
 997                 spin_unlock_irqrestore(&session->lock, flags);
 998                 return;
 999         }
1000
1001         dev = get_device(&conn->cls_conn->dev);
1002         spin_unlock_irqrestore(&session->lock, flags);
1003         if (!dev)
1004                 return;
1005         /*
1006          * if the host is being removed bypass the connection
1007          * recovery initialization because we are going to kill
1008          * the session.
1009          */
1010         if (err == ISCSI_ERR_INVALID_HOST)
1011                 iscsi_conn_error_event(conn->cls_conn, err);
1012         else
1013                 iscsi_conn_failure(conn, err);
1014         put_device(dev);
1015 }
1016 EXPORT_SYMBOL_GPL(iscsi_session_failure);
1017
1018 void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err)
1019 {
1020         struct iscsi_session *session = conn->session;
1021         unsigned long flags;
1022
1023         spin_lock_irqsave(&session->lock, flags);
1024         if (session->state == ISCSI_STATE_FAILED) {
1025                 spin_unlock_irqrestore(&session->lock, flags);
1026                 return;
1027         }
1028
1029         if (conn->stop_stage == 0)
1030                 session->state = ISCSI_STATE_FAILED;
1031         spin_unlock_irqrestore(&session->lock, flags);
1032
1033         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1034         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
1035         iscsi_conn_error_event(conn->cls_conn, err);
1036 }
1037 EXPORT_SYMBOL_GPL(iscsi_conn_failure);
1038
1039 static int iscsi_check_cmdsn_window_closed(struct iscsi_conn *conn)
1040 {
1041         struct iscsi_session *session = conn->session;
1042
1043         /*
1044          * Check for iSCSI window and take care of CmdSN wrap-around
1045          */
1046         if (!iscsi_sna_lte(session->queued_cmdsn, session->max_cmdsn)) {
1047                 debug_scsi("iSCSI CmdSN closed. ExpCmdSn %u MaxCmdSN %u "
1048                            "CmdSN %u/%u\n", session->exp_cmdsn,
1049                            session->max_cmdsn, session->cmdsn,
1050                            session->queued_cmdsn);
1051                 return -ENOSPC;
1052         }
1053         return 0;
1054 }
1055
1056 static int iscsi_xmit_task(struct iscsi_conn *conn)
1057 {
1058         struct iscsi_task *task = conn->task;
1059         int rc;
1060
1061         __iscsi_get_task(task);
1062         spin_unlock_bh(&conn->session->lock);
1063         rc = conn->session->tt->xmit_task(task);
1064         spin_lock_bh(&conn->session->lock);
1065         __iscsi_put_task(task);
1066         if (!rc)
1067                 /* done with this task */
1068                 conn->task = NULL;
1069         return rc;
1070 }
1071
1072 /**
1073  * iscsi_requeue_task - requeue task to run from session workqueue
1074  * @task: task to requeue
1075  *
1076  * LLDs that need to run a task from the session workqueue should call
1077  * this. The session lock must be held. This should only be called
1078  * by software drivers.
1079  */
1080 void iscsi_requeue_task(struct iscsi_task *task)
1081 {
1082         struct iscsi_conn *conn = task->conn;
1083
1084         list_move_tail(&task->running, &conn->requeue);
1085         scsi_queue_work(conn->session->host, &conn->xmitwork);
1086 }
1087 EXPORT_SYMBOL_GPL(iscsi_requeue_task);
1088
1089 /**
1090  * iscsi_data_xmit - xmit any command into the scheduled connection
1091  * @conn: iscsi connection
1092  *
1093  * Notes:
1094  *      The function can return -EAGAIN in which case the caller must
1095  *      re-schedule it again later or recover. '0' return code means
1096  *      successful xmit.
1097  **/
1098 static int iscsi_data_xmit(struct iscsi_conn *conn)
1099 {
1100         int rc = 0;
1101
1102         spin_lock_bh(&conn->session->lock);
1103         if (unlikely(conn->suspend_tx)) {
1104                 debug_scsi("conn %d Tx suspended!\n", conn->id);
1105                 spin_unlock_bh(&conn->session->lock);
1106                 return -ENODATA;
1107         }
1108
1109         if (conn->task) {
1110                 rc = iscsi_xmit_task(conn);
1111                 if (rc)
1112                         goto again;
1113         }
1114
1115         /*
1116          * process mgmt pdus like nops before commands since we should
1117          * only have one nop-out as a ping from us and targets should not
1118          * overflow us with nop-ins
1119          */
1120 check_mgmt:
1121         while (!list_empty(&conn->mgmtqueue)) {
1122                 conn->task = list_entry(conn->mgmtqueue.next,
1123                                          struct iscsi_task, running);
1124                 if (iscsi_prep_mgmt_task(conn, conn->task)) {
1125                         __iscsi_put_task(conn->task);
1126                         conn->task = NULL;
1127                         continue;
1128                 }
1129                 rc = iscsi_xmit_task(conn);
1130                 if (rc)
1131                         goto again;
1132         }
1133
1134         /* process pending command queue */
1135         while (!list_empty(&conn->xmitqueue)) {
1136                 if (conn->tmf_state == TMF_QUEUED)
1137                         break;
1138
1139                 conn->task = list_entry(conn->xmitqueue.next,
1140                                          struct iscsi_task, running);
1141                 if (conn->session->state == ISCSI_STATE_LOGGING_OUT) {
1142                         fail_command(conn, conn->task, DID_IMM_RETRY << 16);
1143                         continue;
1144                 }
1145                 if (iscsi_prep_scsi_cmd_pdu(conn->task)) {
1146                         fail_command(conn, conn->task, DID_ABORT << 16);
1147                         continue;
1148                 }
1149                 rc = iscsi_xmit_task(conn);
1150                 if (rc)
1151                         goto again;
1152                 /*
1153                  * we could continuously get new task requests so
1154                  * we need to check the mgmt queue for nops that need to
1155                  * be sent to aviod starvation
1156                  */
1157                 if (!list_empty(&conn->mgmtqueue))
1158                         goto check_mgmt;
1159         }
1160
1161         while (!list_empty(&conn->requeue)) {
1162                 if (conn->session->fast_abort && conn->tmf_state != TMF_INITIAL)
1163                         break;
1164
1165                 /*
1166                  * we always do fastlogout - conn stop code will clean up.
1167                  */
1168                 if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
1169                         break;
1170
1171                 conn->task = list_entry(conn->requeue.next,
1172                                          struct iscsi_task, running);
1173                 conn->task->state = ISCSI_TASK_RUNNING;
1174                 list_move_tail(conn->requeue.next, &conn->run_list);
1175                 rc = iscsi_xmit_task(conn);
1176                 if (rc)
1177                         goto again;
1178                 if (!list_empty(&conn->mgmtqueue))
1179                         goto check_mgmt;
1180         }
1181         spin_unlock_bh(&conn->session->lock);
1182         return -ENODATA;
1183
1184 again:
1185         if (unlikely(conn->suspend_tx))
1186                 rc = -ENODATA;
1187         spin_unlock_bh(&conn->session->lock);
1188         return rc;
1189 }
1190
1191 static void iscsi_xmitworker(struct work_struct *work)
1192 {
1193         struct iscsi_conn *conn =
1194                 container_of(work, struct iscsi_conn, xmitwork);
1195         int rc;
1196         /*
1197          * serialize Xmit worker on a per-connection basis.
1198          */
1199         do {
1200                 rc = iscsi_data_xmit(conn);
1201         } while (rc >= 0 || rc == -EAGAIN);
1202 }
1203
1204 enum {
1205         FAILURE_BAD_HOST = 1,
1206         FAILURE_SESSION_FAILED,
1207         FAILURE_SESSION_FREED,
1208         FAILURE_WINDOW_CLOSED,
1209         FAILURE_OOM,
1210         FAILURE_SESSION_TERMINATE,
1211         FAILURE_SESSION_IN_RECOVERY,
1212         FAILURE_SESSION_RECOVERY_TIMEOUT,
1213         FAILURE_SESSION_LOGGING_OUT,
1214         FAILURE_SESSION_NOT_READY,
1215 };
1216
1217 int iscsi_queuecommand(struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *))
1218 {
1219         struct iscsi_cls_session *cls_session;
1220         struct Scsi_Host *host;
1221         int reason = 0;
1222         struct iscsi_session *session;
1223         struct iscsi_conn *conn;
1224         struct iscsi_task *task = NULL;
1225
1226         sc->scsi_done = done;
1227         sc->result = 0;
1228         sc->SCp.ptr = NULL;
1229
1230         host = sc->device->host;
1231         spin_unlock(host->host_lock);
1232
1233         cls_session = starget_to_session(scsi_target(sc->device));
1234         session = cls_session->dd_data;
1235         spin_lock(&session->lock);
1236
1237         reason = iscsi_session_chkready(cls_session);
1238         if (reason) {
1239                 sc->result = reason;
1240                 goto fault;
1241         }
1242
1243         /*
1244          * ISCSI_STATE_FAILED is a temp. state. The recovery
1245          * code will decide what is best to do with command queued
1246          * during this time
1247          */
1248         if (session->state != ISCSI_STATE_LOGGED_IN &&
1249             session->state != ISCSI_STATE_FAILED) {
1250                 /*
1251                  * to handle the race between when we set the recovery state
1252                  * and block the session we requeue here (commands could
1253                  * be entering our queuecommand while a block is starting
1254                  * up because the block code is not locked)
1255                  */
1256                 switch (session->state) {
1257                 case ISCSI_STATE_IN_RECOVERY:
1258                         reason = FAILURE_SESSION_IN_RECOVERY;
1259                         goto reject;
1260                 case ISCSI_STATE_LOGGING_OUT:
1261                         reason = FAILURE_SESSION_LOGGING_OUT;
1262                         goto reject;
1263                 case ISCSI_STATE_RECOVERY_FAILED:
1264                         reason = FAILURE_SESSION_RECOVERY_TIMEOUT;
1265                         sc->result = DID_TRANSPORT_FAILFAST << 16;
1266                         break;
1267                 case ISCSI_STATE_TERMINATE:
1268                         reason = FAILURE_SESSION_TERMINATE;
1269                         sc->result = DID_NO_CONNECT << 16;
1270                         break;
1271                 default:
1272                         reason = FAILURE_SESSION_FREED;
1273                         sc->result = DID_NO_CONNECT << 16;
1274                 }
1275                 goto fault;
1276         }
1277
1278         conn = session->leadconn;
1279         if (!conn) {
1280                 reason = FAILURE_SESSION_FREED;
1281                 sc->result = DID_NO_CONNECT << 16;
1282                 goto fault;
1283         }
1284
1285         if (iscsi_check_cmdsn_window_closed(conn)) {
1286                 reason = FAILURE_WINDOW_CLOSED;
1287                 goto reject;
1288         }
1289
1290         if (!__kfifo_get(session->cmdpool.queue, (void*)&task,
1291                          sizeof(void*))) {
1292                 reason = FAILURE_OOM;
1293                 goto reject;
1294         }
1295         sc->SCp.phase = session->age;
1296         sc->SCp.ptr = (char *)task;
1297
1298         atomic_set(&task->refcount, 1);
1299         task->state = ISCSI_TASK_PENDING;
1300         task->conn = conn;
1301         task->sc = sc;
1302         INIT_LIST_HEAD(&task->running);
1303         list_add_tail(&task->running, &conn->xmitqueue);
1304
1305         if (session->tt->caps & CAP_DATA_PATH_OFFLOAD) {
1306                 if (iscsi_prep_scsi_cmd_pdu(task)) {
1307                         sc->result = DID_ABORT << 16;
1308                         sc->scsi_done = NULL;
1309                         iscsi_complete_command(task);
1310                         goto fault;
1311                 }
1312                 if (session->tt->xmit_task(task)) {
1313                         sc->scsi_done = NULL;
1314                         iscsi_complete_command(task);
1315                         reason = FAILURE_SESSION_NOT_READY;
1316                         goto reject;
1317                 }
1318         } else
1319                 scsi_queue_work(session->host, &conn->xmitwork);
1320
1321         session->queued_cmdsn++;
1322         spin_unlock(&session->lock);
1323         spin_lock(host->host_lock);
1324         return 0;
1325
1326 reject:
1327         spin_unlock(&session->lock);
1328         debug_scsi("cmd 0x%x rejected (%d)\n", sc->cmnd[0], reason);
1329         spin_lock(host->host_lock);
1330         return SCSI_MLQUEUE_TARGET_BUSY;
1331
1332 fault:
1333         spin_unlock(&session->lock);
1334         debug_scsi("iscsi: cmd 0x%x is not queued (%d)\n", sc->cmnd[0], reason);
1335         if (!scsi_bidi_cmnd(sc))
1336                 scsi_set_resid(sc, scsi_bufflen(sc));
1337         else {
1338                 scsi_out(sc)->resid = scsi_out(sc)->length;
1339                 scsi_in(sc)->resid = scsi_in(sc)->length;
1340         }
1341         done(sc);
1342         spin_lock(host->host_lock);
1343         return 0;
1344 }
1345 EXPORT_SYMBOL_GPL(iscsi_queuecommand);
1346
1347 int iscsi_change_queue_depth(struct scsi_device *sdev, int depth)
1348 {
1349         if (depth > ISCSI_MAX_CMD_PER_LUN)
1350                 depth = ISCSI_MAX_CMD_PER_LUN;
1351         scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
1352         return sdev->queue_depth;
1353 }
1354 EXPORT_SYMBOL_GPL(iscsi_change_queue_depth);
1355
1356 void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
1357 {
1358         struct iscsi_session *session = cls_session->dd_data;
1359
1360         spin_lock_bh(&session->lock);
1361         if (session->state != ISCSI_STATE_LOGGED_IN) {
1362                 session->state = ISCSI_STATE_RECOVERY_FAILED;
1363                 if (session->leadconn)
1364                         wake_up(&session->leadconn->ehwait);
1365         }
1366         spin_unlock_bh(&session->lock);
1367 }
1368 EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
1369
1370 int iscsi_eh_host_reset(struct scsi_cmnd *sc)
1371 {
1372         struct iscsi_cls_session *cls_session;
1373         struct iscsi_session *session;
1374         struct iscsi_conn *conn;
1375
1376         cls_session = starget_to_session(scsi_target(sc->device));
1377         session = cls_session->dd_data;
1378         conn = session->leadconn;
1379
1380         mutex_lock(&session->eh_mutex);
1381         spin_lock_bh(&session->lock);
1382         if (session->state == ISCSI_STATE_TERMINATE) {
1383 failed:
1384                 debug_scsi("failing host reset: session terminated "
1385                            "[CID %d age %d]\n", conn->id, session->age);
1386                 spin_unlock_bh(&session->lock);
1387                 mutex_unlock(&session->eh_mutex);
1388                 return FAILED;
1389         }
1390
1391         spin_unlock_bh(&session->lock);
1392         mutex_unlock(&session->eh_mutex);
1393         /*
1394          * we drop the lock here but the leadconn cannot be destoyed while
1395          * we are in the scsi eh
1396          */
1397         iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1398
1399         debug_scsi("iscsi_eh_host_reset wait for relogin\n");
1400         wait_event_interruptible(conn->ehwait,
1401                                  session->state == ISCSI_STATE_TERMINATE ||
1402                                  session->state == ISCSI_STATE_LOGGED_IN ||
1403                                  session->state == ISCSI_STATE_RECOVERY_FAILED);
1404         if (signal_pending(current))
1405                 flush_signals(current);
1406
1407         mutex_lock(&session->eh_mutex);
1408         spin_lock_bh(&session->lock);
1409         if (session->state == ISCSI_STATE_LOGGED_IN)
1410                 iscsi_session_printk(KERN_INFO, session,
1411                                      "host reset succeeded\n");
1412         else
1413                 goto failed;
1414         spin_unlock_bh(&session->lock);
1415         mutex_unlock(&session->eh_mutex);
1416         return SUCCESS;
1417 }
1418 EXPORT_SYMBOL_GPL(iscsi_eh_host_reset);
1419
1420 static void iscsi_tmf_timedout(unsigned long data)
1421 {
1422         struct iscsi_conn *conn = (struct iscsi_conn *)data;
1423         struct iscsi_session *session = conn->session;
1424
1425         spin_lock(&session->lock);
1426         if (conn->tmf_state == TMF_QUEUED) {
1427                 conn->tmf_state = TMF_TIMEDOUT;
1428                 debug_scsi("tmf timedout\n");
1429                 /* unblock eh_abort() */
1430                 wake_up(&conn->ehwait);
1431         }
1432         spin_unlock(&session->lock);
1433 }
1434
1435 static int iscsi_exec_task_mgmt_fn(struct iscsi_conn *conn,
1436                                    struct iscsi_tm *hdr, int age,
1437                                    int timeout)
1438 {
1439         struct iscsi_session *session = conn->session;
1440         struct iscsi_task *task;
1441
1442         task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)hdr,
1443                                       NULL, 0);
1444         if (!task) {
1445                 spin_unlock_bh(&session->lock);
1446                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1447                 spin_lock_bh(&session->lock);
1448                 debug_scsi("tmf exec failure\n");
1449                 return -EPERM;
1450         }
1451         conn->tmfcmd_pdus_cnt++;
1452         conn->tmf_timer.expires = timeout * HZ + jiffies;
1453         conn->tmf_timer.function = iscsi_tmf_timedout;
1454         conn->tmf_timer.data = (unsigned long)conn;
1455         add_timer(&conn->tmf_timer);
1456         debug_scsi("tmf set timeout\n");
1457
1458         spin_unlock_bh(&session->lock);
1459         mutex_unlock(&session->eh_mutex);
1460
1461         /*
1462          * block eh thread until:
1463          *
1464          * 1) tmf response
1465          * 2) tmf timeout
1466          * 3) session is terminated or restarted or userspace has
1467          * given up on recovery
1468          */
1469         wait_event_interruptible(conn->ehwait, age != session->age ||
1470                                  session->state != ISCSI_STATE_LOGGED_IN ||
1471                                  conn->tmf_state != TMF_QUEUED);
1472         if (signal_pending(current))
1473                 flush_signals(current);
1474         del_timer_sync(&conn->tmf_timer);
1475
1476         mutex_lock(&session->eh_mutex);
1477         spin_lock_bh(&session->lock);
1478         /* if the session drops it will clean up the task */
1479         if (age != session->age ||
1480             session->state != ISCSI_STATE_LOGGED_IN)
1481                 return -ENOTCONN;
1482         return 0;
1483 }
1484
1485 /*
1486  * Fail commands. session lock held and recv side suspended and xmit
1487  * thread flushed
1488  */
1489 static void fail_all_commands(struct iscsi_conn *conn, unsigned lun,
1490                               int error)
1491 {
1492         struct iscsi_task *task, *tmp;
1493
1494         if (conn->task && (conn->task->sc->device->lun == lun || lun == -1))
1495                 conn->task = NULL;
1496
1497         /* flush pending */
1498         list_for_each_entry_safe(task, tmp, &conn->xmitqueue, running) {
1499                 if (lun == task->sc->device->lun || lun == -1) {
1500                         debug_scsi("failing pending sc %p itt 0x%x\n",
1501                                    task->sc, task->itt);
1502                         fail_command(conn, task, error << 16);
1503                 }
1504         }
1505
1506         list_for_each_entry_safe(task, tmp, &conn->requeue, running) {
1507                 if (lun == task->sc->device->lun || lun == -1) {
1508                         debug_scsi("failing requeued sc %p itt 0x%x\n",
1509                                    task->sc, task->itt);
1510                         fail_command(conn, task, error << 16);
1511                 }
1512         }
1513
1514         /* fail all other running */
1515         list_for_each_entry_safe(task, tmp, &conn->run_list, running) {
1516                 if (lun == task->sc->device->lun || lun == -1) {
1517                         debug_scsi("failing in progress sc %p itt 0x%x\n",
1518                                    task->sc, task->itt);
1519                         fail_command(conn, task, error << 16);
1520                 }
1521         }
1522 }
1523
1524 void iscsi_suspend_tx(struct iscsi_conn *conn)
1525 {
1526         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1527         if (!(conn->session->tt->caps & CAP_DATA_PATH_OFFLOAD))
1528                 scsi_flush_work(conn->session->host);
1529 }
1530 EXPORT_SYMBOL_GPL(iscsi_suspend_tx);
1531
1532 static void iscsi_start_tx(struct iscsi_conn *conn)
1533 {
1534         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1535         if (!(conn->session->tt->caps & CAP_DATA_PATH_OFFLOAD))
1536                 scsi_queue_work(conn->session->host, &conn->xmitwork);
1537 }
1538
1539 static enum blk_eh_timer_return iscsi_eh_cmd_timed_out(struct scsi_cmnd *scmd)
1540 {
1541         struct iscsi_cls_session *cls_session;
1542         struct iscsi_session *session;
1543         struct iscsi_conn *conn;
1544         enum blk_eh_timer_return rc = BLK_EH_NOT_HANDLED;
1545
1546         cls_session = starget_to_session(scsi_target(scmd->device));
1547         session = cls_session->dd_data;
1548
1549         debug_scsi("scsi cmd %p timedout\n", scmd);
1550
1551         spin_lock(&session->lock);
1552         if (session->state != ISCSI_STATE_LOGGED_IN) {
1553                 /*
1554                  * We are probably in the middle of iscsi recovery so let
1555                  * that complete and handle the error.
1556                  */
1557                 rc = BLK_EH_RESET_TIMER;
1558                 goto done;
1559         }
1560
1561         conn = session->leadconn;
1562         if (!conn) {
1563                 /* In the middle of shuting down */
1564                 rc = BLK_EH_RESET_TIMER;
1565                 goto done;
1566         }
1567
1568         if (!conn->recv_timeout && !conn->ping_timeout)
1569                 goto done;
1570         /*
1571          * if the ping timedout then we are in the middle of cleaning up
1572          * and can let the iscsi eh handle it
1573          */
1574         if (time_before_eq(conn->last_recv + (conn->recv_timeout * HZ) +
1575                             (conn->ping_timeout * HZ), jiffies))
1576                 rc = BLK_EH_RESET_TIMER;
1577         /*
1578          * if we are about to check the transport then give the command
1579          * more time
1580          */
1581         if (time_before_eq(conn->last_recv + (conn->recv_timeout * HZ),
1582                            jiffies))
1583                 rc = BLK_EH_RESET_TIMER;
1584         /* if in the middle of checking the transport then give us more time */
1585         if (conn->ping_task)
1586                 rc = BLK_EH_RESET_TIMER;
1587 done:
1588         spin_unlock(&session->lock);
1589         debug_scsi("return %s\n", rc == BLK_EH_RESET_TIMER ?
1590                                         "timer reset" : "nh");
1591         return rc;
1592 }
1593
1594 static void iscsi_check_transport_timeouts(unsigned long data)
1595 {
1596         struct iscsi_conn *conn = (struct iscsi_conn *)data;
1597         struct iscsi_session *session = conn->session;
1598         unsigned long recv_timeout, next_timeout = 0, last_recv;
1599
1600         spin_lock(&session->lock);
1601         if (session->state != ISCSI_STATE_LOGGED_IN)
1602                 goto done;
1603
1604         recv_timeout = conn->recv_timeout;
1605         if (!recv_timeout)
1606                 goto done;
1607
1608         recv_timeout *= HZ;
1609         last_recv = conn->last_recv;
1610         if (conn->ping_task &&
1611             time_before_eq(conn->last_ping + (conn->ping_timeout * HZ),
1612                            jiffies)) {
1613                 iscsi_conn_printk(KERN_ERR, conn, "ping timeout of %d secs "
1614                                   "expired, last rx %lu, last ping %lu, "
1615                                   "now %lu\n", conn->ping_timeout, last_recv,
1616                                   conn->last_ping, jiffies);
1617                 spin_unlock(&session->lock);
1618                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1619                 return;
1620         }
1621
1622         if (time_before_eq(last_recv + recv_timeout, jiffies)) {
1623                 /* send a ping to try to provoke some traffic */
1624                 debug_scsi("Sending nopout as ping on conn %p\n", conn);
1625                 iscsi_send_nopout(conn, NULL);
1626                 next_timeout = conn->last_ping + (conn->ping_timeout * HZ);
1627         } else
1628                 next_timeout = last_recv + recv_timeout;
1629
1630         debug_scsi("Setting next tmo %lu\n", next_timeout);
1631         mod_timer(&conn->transport_timer, next_timeout);
1632 done:
1633         spin_unlock(&session->lock);
1634 }
1635
1636 static void iscsi_prep_abort_task_pdu(struct iscsi_task *task,
1637                                       struct iscsi_tm *hdr)
1638 {
1639         memset(hdr, 0, sizeof(*hdr));
1640         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
1641         hdr->flags = ISCSI_TM_FUNC_ABORT_TASK & ISCSI_FLAG_TM_FUNC_MASK;
1642         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
1643         memcpy(hdr->lun, task->hdr->lun, sizeof(hdr->lun));
1644         hdr->rtt = task->hdr->itt;
1645         hdr->refcmdsn = task->hdr->cmdsn;
1646 }
1647
1648 int iscsi_eh_abort(struct scsi_cmnd *sc)
1649 {
1650         struct iscsi_cls_session *cls_session;
1651         struct iscsi_session *session;
1652         struct iscsi_conn *conn;
1653         struct iscsi_task *task;
1654         struct iscsi_tm *hdr;
1655         int rc, age;
1656
1657         cls_session = starget_to_session(scsi_target(sc->device));
1658         session = cls_session->dd_data;
1659
1660         mutex_lock(&session->eh_mutex);
1661         spin_lock_bh(&session->lock);
1662         /*
1663          * if session was ISCSI_STATE_IN_RECOVERY then we may not have
1664          * got the command.
1665          */
1666         if (!sc->SCp.ptr) {
1667                 debug_scsi("sc never reached iscsi layer or it completed.\n");
1668                 spin_unlock_bh(&session->lock);
1669                 mutex_unlock(&session->eh_mutex);
1670                 return SUCCESS;
1671         }
1672
1673         /*
1674          * If we are not logged in or we have started a new session
1675          * then let the host reset code handle this
1676          */
1677         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN ||
1678             sc->SCp.phase != session->age) {
1679                 spin_unlock_bh(&session->lock);
1680                 mutex_unlock(&session->eh_mutex);
1681                 return FAILED;
1682         }
1683
1684         conn = session->leadconn;
1685         conn->eh_abort_cnt++;
1686         age = session->age;
1687
1688         task = (struct iscsi_task *)sc->SCp.ptr;
1689         debug_scsi("aborting [sc %p itt 0x%x]\n", sc, task->itt);
1690
1691         /* task completed before time out */
1692         if (!task->sc) {
1693                 debug_scsi("sc completed while abort in progress\n");
1694                 goto success;
1695         }
1696
1697         if (task->state == ISCSI_TASK_PENDING) {
1698                 fail_command(conn, task, DID_ABORT << 16);
1699                 goto success;
1700         }
1701
1702         /* only have one tmf outstanding at a time */
1703         if (conn->tmf_state != TMF_INITIAL)
1704                 goto failed;
1705         conn->tmf_state = TMF_QUEUED;
1706
1707         hdr = &conn->tmhdr;
1708         iscsi_prep_abort_task_pdu(task, hdr);
1709
1710         if (iscsi_exec_task_mgmt_fn(conn, hdr, age, session->abort_timeout)) {
1711                 rc = FAILED;
1712                 goto failed;
1713         }
1714
1715         switch (conn->tmf_state) {
1716         case TMF_SUCCESS:
1717                 spin_unlock_bh(&session->lock);
1718                 /*
1719                  * stop tx side incase the target had sent a abort rsp but
1720                  * the initiator was still writing out data.
1721                  */
1722                 iscsi_suspend_tx(conn);
1723                 /*
1724                  * we do not stop the recv side because targets have been
1725                  * good and have never sent us a successful tmf response
1726                  * then sent more data for the cmd.
1727                  */
1728                 spin_lock(&session->lock);
1729                 fail_command(conn, task, DID_ABORT << 16);
1730                 conn->tmf_state = TMF_INITIAL;
1731                 spin_unlock(&session->lock);
1732                 iscsi_start_tx(conn);
1733                 goto success_unlocked;
1734         case TMF_TIMEDOUT:
1735                 spin_unlock_bh(&session->lock);
1736                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1737                 goto failed_unlocked;
1738         case TMF_NOT_FOUND:
1739                 if (!sc->SCp.ptr) {
1740                         conn->tmf_state = TMF_INITIAL;
1741                         /* task completed before tmf abort response */
1742                         debug_scsi("sc completed while abort in progress\n");
1743                         goto success;
1744                 }
1745                 /* fall through */
1746         default:
1747                 conn->tmf_state = TMF_INITIAL;
1748                 goto failed;
1749         }
1750
1751 success:
1752         spin_unlock_bh(&session->lock);
1753 success_unlocked:
1754         debug_scsi("abort success [sc %lx itt 0x%x]\n", (long)sc, task->itt);
1755         mutex_unlock(&session->eh_mutex);
1756         return SUCCESS;
1757
1758 failed:
1759         spin_unlock_bh(&session->lock);
1760 failed_unlocked:
1761         debug_scsi("abort failed [sc %p itt 0x%x]\n", sc,
1762                     task ? task->itt : 0);
1763         mutex_unlock(&session->eh_mutex);
1764         return FAILED;
1765 }
1766 EXPORT_SYMBOL_GPL(iscsi_eh_abort);
1767
1768 static void iscsi_prep_lun_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
1769 {
1770         memset(hdr, 0, sizeof(*hdr));
1771         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
1772         hdr->flags = ISCSI_TM_FUNC_LOGICAL_UNIT_RESET & ISCSI_FLAG_TM_FUNC_MASK;
1773         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
1774         int_to_scsilun(sc->device->lun, (struct scsi_lun *)hdr->lun);
1775         hdr->rtt = RESERVED_ITT;
1776 }
1777
1778 int iscsi_eh_device_reset(struct scsi_cmnd *sc)
1779 {
1780         struct iscsi_cls_session *cls_session;
1781         struct iscsi_session *session;
1782         struct iscsi_conn *conn;
1783         struct iscsi_tm *hdr;
1784         int rc = FAILED;
1785
1786         cls_session = starget_to_session(scsi_target(sc->device));
1787         session = cls_session->dd_data;
1788
1789         debug_scsi("LU Reset [sc %p lun %u]\n", sc, sc->device->lun);
1790
1791         mutex_lock(&session->eh_mutex);
1792         spin_lock_bh(&session->lock);
1793         /*
1794          * Just check if we are not logged in. We cannot check for
1795          * the phase because the reset could come from a ioctl.
1796          */
1797         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
1798                 goto unlock;
1799         conn = session->leadconn;
1800
1801         /* only have one tmf outstanding at a time */
1802         if (conn->tmf_state != TMF_INITIAL)
1803                 goto unlock;
1804         conn->tmf_state = TMF_QUEUED;
1805
1806         hdr = &conn->tmhdr;
1807         iscsi_prep_lun_reset_pdu(sc, hdr);
1808
1809         if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
1810                                     session->lu_reset_timeout)) {
1811                 rc = FAILED;
1812                 goto unlock;
1813         }
1814
1815         switch (conn->tmf_state) {
1816         case TMF_SUCCESS:
1817                 break;
1818         case TMF_TIMEDOUT:
1819                 spin_unlock_bh(&session->lock);
1820                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1821                 goto done;
1822         default:
1823                 conn->tmf_state = TMF_INITIAL;
1824                 goto unlock;
1825         }
1826
1827         rc = SUCCESS;
1828         spin_unlock_bh(&session->lock);
1829
1830         iscsi_suspend_tx(conn);
1831
1832         spin_lock(&session->lock);
1833         fail_all_commands(conn, sc->device->lun, DID_ERROR);
1834         conn->tmf_state = TMF_INITIAL;
1835         spin_unlock(&session->lock);
1836
1837         iscsi_start_tx(conn);
1838         goto done;
1839
1840 unlock:
1841         spin_unlock_bh(&session->lock);
1842 done:
1843         debug_scsi("iscsi_eh_device_reset %s\n",
1844                   rc == SUCCESS ? "SUCCESS" : "FAILED");
1845         mutex_unlock(&session->eh_mutex);
1846         return rc;
1847 }
1848 EXPORT_SYMBOL_GPL(iscsi_eh_device_reset);
1849
1850 /*
1851  * Pre-allocate a pool of @max items of @item_size. By default, the pool
1852  * should be accessed via kfifo_{get,put} on q->queue.
1853  * Optionally, the caller can obtain the array of object pointers
1854  * by passing in a non-NULL @items pointer
1855  */
1856 int
1857 iscsi_pool_init(struct iscsi_pool *q, int max, void ***items, int item_size)
1858 {
1859         int i, num_arrays = 1;
1860
1861         memset(q, 0, sizeof(*q));
1862
1863         q->max = max;
1864
1865         /* If the user passed an items pointer, he wants a copy of
1866          * the array. */
1867         if (items)
1868                 num_arrays++;
1869         q->pool = kzalloc(num_arrays * max * sizeof(void*), GFP_KERNEL);
1870         if (q->pool == NULL)
1871                 goto enomem;
1872
1873         q->queue = kfifo_init((void*)q->pool, max * sizeof(void*),
1874                               GFP_KERNEL, NULL);
1875         if (q->queue == ERR_PTR(-ENOMEM))
1876                 goto enomem;
1877
1878         for (i = 0; i < max; i++) {
1879                 q->pool[i] = kzalloc(item_size, GFP_KERNEL);
1880                 if (q->pool[i] == NULL) {
1881                         q->max = i;
1882                         goto enomem;
1883                 }
1884                 __kfifo_put(q->queue, (void*)&q->pool[i], sizeof(void*));
1885         }
1886
1887         if (items) {
1888                 *items = q->pool + max;
1889                 memcpy(*items, q->pool, max * sizeof(void *));
1890         }
1891
1892         return 0;
1893
1894 enomem:
1895         iscsi_pool_free(q);
1896         return -ENOMEM;
1897 }
1898 EXPORT_SYMBOL_GPL(iscsi_pool_init);
1899
1900 void iscsi_pool_free(struct iscsi_pool *q)
1901 {
1902         int i;
1903
1904         for (i = 0; i < q->max; i++)
1905                 kfree(q->pool[i]);
1906         if (q->pool)
1907                 kfree(q->pool);
1908 }
1909 EXPORT_SYMBOL_GPL(iscsi_pool_free);
1910
1911 /**
1912  * iscsi_host_add - add host to system
1913  * @shost: scsi host
1914  * @pdev: parent device
1915  *
1916  * This should be called by partial offload and software iscsi drivers
1917  * to add a host to the system.
1918  */
1919 int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev)
1920 {
1921         if (!shost->can_queue)
1922                 shost->can_queue = ISCSI_DEF_XMIT_CMDS_MAX;
1923
1924         return scsi_add_host(shost, pdev);
1925 }
1926 EXPORT_SYMBOL_GPL(iscsi_host_add);
1927
1928 /**
1929  * iscsi_host_alloc - allocate a host and driver data
1930  * @sht: scsi host template
1931  * @dd_data_size: driver host data size
1932  * @qdepth: default device queue depth
1933  *
1934  * This should be called by partial offload and software iscsi drivers.
1935  * To access the driver specific memory use the iscsi_host_priv() macro.
1936  */
1937 struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
1938                                    int dd_data_size, uint16_t qdepth)
1939 {
1940         struct Scsi_Host *shost;
1941         struct iscsi_host *ihost;
1942
1943         shost = scsi_host_alloc(sht, sizeof(struct iscsi_host) + dd_data_size);
1944         if (!shost)
1945                 return NULL;
1946         shost->transportt->eh_timed_out = iscsi_eh_cmd_timed_out;
1947
1948         if (qdepth > ISCSI_MAX_CMD_PER_LUN || qdepth < 1) {
1949                 if (qdepth != 0)
1950                         printk(KERN_ERR "iscsi: invalid queue depth of %d. "
1951                                "Queue depth must be between 1 and %d.\n",
1952                                qdepth, ISCSI_MAX_CMD_PER_LUN);
1953                 qdepth = ISCSI_DEF_CMD_PER_LUN;
1954         }
1955         shost->cmd_per_lun = qdepth;
1956
1957         ihost = shost_priv(shost);
1958         spin_lock_init(&ihost->lock);
1959         ihost->state = ISCSI_HOST_SETUP;
1960         ihost->num_sessions = 0;
1961         init_waitqueue_head(&ihost->session_removal_wq);
1962         return shost;
1963 }
1964 EXPORT_SYMBOL_GPL(iscsi_host_alloc);
1965
1966 static void iscsi_notify_host_removed(struct iscsi_cls_session *cls_session)
1967 {
1968         iscsi_session_failure(cls_session, ISCSI_ERR_INVALID_HOST);
1969 }
1970
1971 /**
1972  * iscsi_host_remove - remove host and sessions
1973  * @shost: scsi host
1974  *
1975  * If there are any sessions left, this will initiate the removal and wait
1976  * for the completion.
1977  */
1978 void iscsi_host_remove(struct Scsi_Host *shost)
1979 {
1980         struct iscsi_host *ihost = shost_priv(shost);
1981         unsigned long flags;
1982
1983         spin_lock_irqsave(&ihost->lock, flags);
1984         ihost->state = ISCSI_HOST_REMOVED;
1985         spin_unlock_irqrestore(&ihost->lock, flags);
1986
1987         iscsi_host_for_each_session(shost, iscsi_notify_host_removed);
1988         wait_event_interruptible(ihost->session_removal_wq,
1989                                  ihost->num_sessions == 0);
1990         if (signal_pending(current))
1991                 flush_signals(current);
1992
1993         scsi_remove_host(shost);
1994 }
1995 EXPORT_SYMBOL_GPL(iscsi_host_remove);
1996
1997 void iscsi_host_free(struct Scsi_Host *shost)
1998 {
1999         struct iscsi_host *ihost = shost_priv(shost);
2000
2001         kfree(ihost->netdev);
2002         kfree(ihost->hwaddress);
2003         kfree(ihost->initiatorname);
2004         scsi_host_put(shost);
2005 }
2006 EXPORT_SYMBOL_GPL(iscsi_host_free);
2007
2008 static void iscsi_host_dec_session_cnt(struct Scsi_Host *shost)
2009 {
2010         struct iscsi_host *ihost = shost_priv(shost);
2011         unsigned long flags;
2012
2013         shost = scsi_host_get(shost);
2014         if (!shost) {
2015                 printk(KERN_ERR "Invalid state. Cannot notify host removal "
2016                       "of session teardown event because host already "
2017                       "removed.\n");
2018                 return;
2019         }
2020
2021         spin_lock_irqsave(&ihost->lock, flags);
2022         ihost->num_sessions--;
2023         if (ihost->num_sessions == 0)
2024                 wake_up(&ihost->session_removal_wq);
2025         spin_unlock_irqrestore(&ihost->lock, flags);
2026         scsi_host_put(shost);
2027 }
2028
2029 /**
2030  * iscsi_session_setup - create iscsi cls session and host and session
2031  * @iscsit: iscsi transport template
2032  * @shost: scsi host
2033  * @cmds_max: session can queue
2034  * @cmd_task_size: LLD task private data size
2035  * @initial_cmdsn: initial CmdSN
2036  *
2037  * This can be used by software iscsi_transports that allocate
2038  * a session per scsi host.
2039  *
2040  * Callers should set cmds_max to the largest total numer (mgmt + scsi) of
2041  * tasks they support. The iscsi layer reserves ISCSI_MGMT_CMDS_MAX tasks
2042  * for nop handling and login/logout requests.
2043  */
2044 struct iscsi_cls_session *
2045 iscsi_session_setup(struct iscsi_transport *iscsit, struct Scsi_Host *shost,
2046                     uint16_t cmds_max, int cmd_task_size,
2047                     uint32_t initial_cmdsn, unsigned int id)
2048 {
2049         struct iscsi_host *ihost = shost_priv(shost);
2050         struct iscsi_session *session;
2051         struct iscsi_cls_session *cls_session;
2052         int cmd_i, scsi_cmds, total_cmds = cmds_max;
2053         unsigned long flags;
2054
2055         spin_lock_irqsave(&ihost->lock, flags);
2056         if (ihost->state == ISCSI_HOST_REMOVED) {
2057                 spin_unlock_irqrestore(&ihost->lock, flags);
2058                 return NULL;
2059         }
2060         ihost->num_sessions++;
2061         spin_unlock_irqrestore(&ihost->lock, flags);
2062
2063         if (!total_cmds)
2064                 total_cmds = ISCSI_DEF_XMIT_CMDS_MAX;
2065         /*
2066          * The iscsi layer needs some tasks for nop handling and tmfs,
2067          * so the cmds_max must at least be greater than ISCSI_MGMT_CMDS_MAX
2068          * + 1 command for scsi IO.
2069          */
2070         if (total_cmds < ISCSI_TOTAL_CMDS_MIN) {
2071                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2072                        "must be a power of two that is at least %d.\n",
2073                        total_cmds, ISCSI_TOTAL_CMDS_MIN);
2074                 goto dec_session_count;
2075         }
2076
2077         if (total_cmds > ISCSI_TOTAL_CMDS_MAX) {
2078                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2079                        "must be a power of 2 less than or equal to %d.\n",
2080                        cmds_max, ISCSI_TOTAL_CMDS_MAX);
2081                 total_cmds = ISCSI_TOTAL_CMDS_MAX;
2082         }
2083
2084         if (!is_power_of_2(total_cmds)) {
2085                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2086                        "must be a power of 2.\n", total_cmds);
2087                 total_cmds = rounddown_pow_of_two(total_cmds);
2088                 if (total_cmds < ISCSI_TOTAL_CMDS_MIN)
2089                         return NULL;
2090                 printk(KERN_INFO "iscsi: Rounding can_queue to %d.\n",
2091                        total_cmds);
2092         }
2093         scsi_cmds = total_cmds - ISCSI_MGMT_CMDS_MAX;
2094
2095         cls_session = iscsi_alloc_session(shost, iscsit,
2096                                           sizeof(struct iscsi_session));
2097         if (!cls_session)
2098                 goto dec_session_count;
2099         session = cls_session->dd_data;
2100         session->cls_session = cls_session;
2101         session->host = shost;
2102         session->state = ISCSI_STATE_FREE;
2103         session->fast_abort = 1;
2104         session->lu_reset_timeout = 15;
2105         session->abort_timeout = 10;
2106         session->scsi_cmds_max = scsi_cmds;
2107         session->cmds_max = total_cmds;
2108         session->queued_cmdsn = session->cmdsn = initial_cmdsn;
2109         session->exp_cmdsn = initial_cmdsn + 1;
2110         session->max_cmdsn = initial_cmdsn + 1;
2111         session->max_r2t = 1;
2112         session->tt = iscsit;
2113         mutex_init(&session->eh_mutex);
2114         spin_lock_init(&session->lock);
2115
2116         /* initialize SCSI PDU commands pool */
2117         if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
2118                             (void***)&session->cmds,
2119                             cmd_task_size + sizeof(struct iscsi_task)))
2120                 goto cmdpool_alloc_fail;
2121
2122         /* pre-format cmds pool with ITT */
2123         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
2124                 struct iscsi_task *task = session->cmds[cmd_i];
2125
2126                 if (cmd_task_size)
2127                         task->dd_data = &task[1];
2128                 task->itt = cmd_i;
2129                 INIT_LIST_HEAD(&task->running);
2130         }
2131
2132         if (!try_module_get(iscsit->owner))
2133                 goto module_get_fail;
2134
2135         if (iscsi_add_session(cls_session, id))
2136                 goto cls_session_fail;
2137
2138         return cls_session;
2139
2140 cls_session_fail:
2141         module_put(iscsit->owner);
2142 module_get_fail:
2143         iscsi_pool_free(&session->cmdpool);
2144 cmdpool_alloc_fail:
2145         iscsi_free_session(cls_session);
2146 dec_session_count:
2147         iscsi_host_dec_session_cnt(shost);
2148         return NULL;
2149 }
2150 EXPORT_SYMBOL_GPL(iscsi_session_setup);
2151
2152 /**
2153  * iscsi_session_teardown - destroy session, host, and cls_session
2154  * @cls_session: iscsi session
2155  *
2156  * The driver must have called iscsi_remove_session before
2157  * calling this.
2158  */
2159 void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
2160 {
2161         struct iscsi_session *session = cls_session->dd_data;
2162         struct module *owner = cls_session->transport->owner;
2163         struct Scsi_Host *shost = session->host;
2164
2165         iscsi_pool_free(&session->cmdpool);
2166
2167         kfree(session->password);
2168         kfree(session->password_in);
2169         kfree(session->username);
2170         kfree(session->username_in);
2171         kfree(session->targetname);
2172         kfree(session->initiatorname);
2173         kfree(session->ifacename);
2174
2175         iscsi_destroy_session(cls_session);
2176         iscsi_host_dec_session_cnt(shost);
2177         module_put(owner);
2178 }
2179 EXPORT_SYMBOL_GPL(iscsi_session_teardown);
2180
2181 /**
2182  * iscsi_conn_setup - create iscsi_cls_conn and iscsi_conn
2183  * @cls_session: iscsi_cls_session
2184  * @dd_size: private driver data size
2185  * @conn_idx: cid
2186  */
2187 struct iscsi_cls_conn *
2188 iscsi_conn_setup(struct iscsi_cls_session *cls_session, int dd_size,
2189                  uint32_t conn_idx)
2190 {
2191         struct iscsi_session *session = cls_session->dd_data;
2192         struct iscsi_conn *conn;
2193         struct iscsi_cls_conn *cls_conn;
2194         char *data;
2195
2196         cls_conn = iscsi_create_conn(cls_session, sizeof(*conn) + dd_size,
2197                                      conn_idx);
2198         if (!cls_conn)
2199                 return NULL;
2200         conn = cls_conn->dd_data;
2201         memset(conn, 0, sizeof(*conn) + dd_size);
2202
2203         conn->dd_data = cls_conn->dd_data + sizeof(*conn);
2204         conn->session = session;
2205         conn->cls_conn = cls_conn;
2206         conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
2207         conn->id = conn_idx;
2208         conn->exp_statsn = 0;
2209         conn->tmf_state = TMF_INITIAL;
2210
2211         init_timer(&conn->transport_timer);
2212         conn->transport_timer.data = (unsigned long)conn;
2213         conn->transport_timer.function = iscsi_check_transport_timeouts;
2214
2215         INIT_LIST_HEAD(&conn->run_list);
2216         INIT_LIST_HEAD(&conn->mgmt_run_list);
2217         INIT_LIST_HEAD(&conn->mgmtqueue);
2218         INIT_LIST_HEAD(&conn->xmitqueue);
2219         INIT_LIST_HEAD(&conn->requeue);
2220         INIT_WORK(&conn->xmitwork, iscsi_xmitworker);
2221
2222         /* allocate login_task used for the login/text sequences */
2223         spin_lock_bh(&session->lock);
2224         if (!__kfifo_get(session->cmdpool.queue,
2225                          (void*)&conn->login_task,
2226                          sizeof(void*))) {
2227                 spin_unlock_bh(&session->lock);
2228                 goto login_task_alloc_fail;
2229         }
2230         spin_unlock_bh(&session->lock);
2231
2232         data = kmalloc(ISCSI_DEF_MAX_RECV_SEG_LEN, GFP_KERNEL);
2233         if (!data)
2234                 goto login_task_data_alloc_fail;
2235         conn->login_task->data = conn->data = data;
2236
2237         init_timer(&conn->tmf_timer);
2238         init_waitqueue_head(&conn->ehwait);
2239
2240         return cls_conn;
2241
2242 login_task_data_alloc_fail:
2243         __kfifo_put(session->cmdpool.queue, (void*)&conn->login_task,
2244                     sizeof(void*));
2245 login_task_alloc_fail:
2246         iscsi_destroy_conn(cls_conn);
2247         return NULL;
2248 }
2249 EXPORT_SYMBOL_GPL(iscsi_conn_setup);
2250
2251 /**
2252  * iscsi_conn_teardown - teardown iscsi connection
2253  * cls_conn: iscsi class connection
2254  *
2255  * TODO: we may need to make this into a two step process
2256  * like scsi-mls remove + put host
2257  */
2258 void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
2259 {
2260         struct iscsi_conn *conn = cls_conn->dd_data;
2261         struct iscsi_session *session = conn->session;
2262         unsigned long flags;
2263
2264         del_timer_sync(&conn->transport_timer);
2265
2266         spin_lock_bh(&session->lock);
2267         conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
2268         if (session->leadconn == conn) {
2269                 /*
2270                  * leading connection? then give up on recovery.
2271                  */
2272                 session->state = ISCSI_STATE_TERMINATE;
2273                 wake_up(&conn->ehwait);
2274         }
2275         spin_unlock_bh(&session->lock);
2276
2277         /*
2278          * Block until all in-progress commands for this connection
2279          * time out or fail.
2280          */
2281         for (;;) {
2282                 spin_lock_irqsave(session->host->host_lock, flags);
2283                 if (!session->host->host_busy) { /* OK for ERL == 0 */
2284                         spin_unlock_irqrestore(session->host->host_lock, flags);
2285                         break;
2286                 }
2287                 spin_unlock_irqrestore(session->host->host_lock, flags);
2288                 msleep_interruptible(500);
2289                 iscsi_conn_printk(KERN_INFO, conn, "iscsi conn_destroy(): "
2290                                   "host_busy %d host_failed %d\n",
2291                                   session->host->host_busy,
2292                                   session->host->host_failed);
2293                 /*
2294                  * force eh_abort() to unblock
2295                  */
2296                 wake_up(&conn->ehwait);
2297         }
2298
2299         /* flush queued up work because we free the connection below */
2300         iscsi_suspend_tx(conn);
2301
2302         spin_lock_bh(&session->lock);
2303         kfree(conn->data);
2304         kfree(conn->persistent_address);
2305         __kfifo_put(session->cmdpool.queue, (void*)&conn->login_task,
2306                     sizeof(void*));
2307         if (session->leadconn == conn)
2308                 session->leadconn = NULL;
2309         spin_unlock_bh(&session->lock);
2310
2311         iscsi_destroy_conn(cls_conn);
2312 }
2313 EXPORT_SYMBOL_GPL(iscsi_conn_teardown);
2314
2315 int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
2316 {
2317         struct iscsi_conn *conn = cls_conn->dd_data;
2318         struct iscsi_session *session = conn->session;
2319
2320         if (!session) {
2321                 iscsi_conn_printk(KERN_ERR, conn,
2322                                   "can't start unbound connection\n");
2323                 return -EPERM;
2324         }
2325
2326         if ((session->imm_data_en || !session->initial_r2t_en) &&
2327              session->first_burst > session->max_burst) {
2328                 iscsi_conn_printk(KERN_INFO, conn, "invalid burst lengths: "
2329                                   "first_burst %d max_burst %d\n",
2330                                   session->first_burst, session->max_burst);
2331                 return -EINVAL;
2332         }
2333
2334         if (conn->ping_timeout && !conn->recv_timeout) {
2335                 iscsi_conn_printk(KERN_ERR, conn, "invalid recv timeout of "
2336                                   "zero. Using 5 seconds\n.");
2337                 conn->recv_timeout = 5;
2338         }
2339
2340         if (conn->recv_timeout && !conn->ping_timeout) {
2341                 iscsi_conn_printk(KERN_ERR, conn, "invalid ping timeout of "
2342                                   "zero. Using 5 seconds.\n");
2343                 conn->ping_timeout = 5;
2344         }
2345
2346         spin_lock_bh(&session->lock);
2347         conn->c_stage = ISCSI_CONN_STARTED;
2348         session->state = ISCSI_STATE_LOGGED_IN;
2349         session->queued_cmdsn = session->cmdsn;
2350
2351         conn->last_recv = jiffies;
2352         conn->last_ping = jiffies;
2353         if (conn->recv_timeout && conn->ping_timeout)
2354                 mod_timer(&conn->transport_timer,
2355                           jiffies + (conn->recv_timeout * HZ));
2356
2357         switch(conn->stop_stage) {
2358         case STOP_CONN_RECOVER:
2359                 /*
2360                  * unblock eh_abort() if it is blocked. re-try all
2361                  * commands after successful recovery
2362                  */
2363                 conn->stop_stage = 0;
2364                 conn->tmf_state = TMF_INITIAL;
2365                 session->age++;
2366                 if (session->age == 16)
2367                         session->age = 0;
2368                 break;
2369         case STOP_CONN_TERM:
2370                 conn->stop_stage = 0;
2371                 break;
2372         default:
2373                 break;
2374         }
2375         spin_unlock_bh(&session->lock);
2376
2377         iscsi_unblock_session(session->cls_session);
2378         wake_up(&conn->ehwait);
2379         return 0;
2380 }
2381 EXPORT_SYMBOL_GPL(iscsi_conn_start);
2382
2383 static void
2384 flush_control_queues(struct iscsi_session *session, struct iscsi_conn *conn)
2385 {
2386         struct iscsi_task *task, *tmp;
2387
2388         /* handle pending */
2389         list_for_each_entry_safe(task, tmp, &conn->mgmtqueue, running) {
2390                 debug_scsi("flushing pending mgmt task itt 0x%x\n", task->itt);
2391                 /* release ref from prep task */
2392                 __iscsi_put_task(task);
2393         }
2394
2395         /* handle running */
2396         list_for_each_entry_safe(task, tmp, &conn->mgmt_run_list, running) {
2397                 debug_scsi("flushing running mgmt task itt 0x%x\n", task->itt);
2398                 /* release ref from prep task */
2399                 __iscsi_put_task(task);
2400         }
2401
2402         conn->task = NULL;
2403 }
2404
2405 static void iscsi_start_session_recovery(struct iscsi_session *session,
2406                                          struct iscsi_conn *conn, int flag)
2407 {
2408         int old_stop_stage;
2409
2410         del_timer_sync(&conn->transport_timer);
2411
2412         mutex_lock(&session->eh_mutex);
2413         spin_lock_bh(&session->lock);
2414         if (conn->stop_stage == STOP_CONN_TERM) {
2415                 spin_unlock_bh(&session->lock);
2416                 mutex_unlock(&session->eh_mutex);
2417                 return;
2418         }
2419
2420         /*
2421          * When this is called for the in_login state, we only want to clean
2422          * up the login task and connection. We do not need to block and set
2423          * the recovery state again
2424          */
2425         if (flag == STOP_CONN_TERM)
2426                 session->state = ISCSI_STATE_TERMINATE;
2427         else if (conn->stop_stage != STOP_CONN_RECOVER)
2428                 session->state = ISCSI_STATE_IN_RECOVERY;
2429
2430         old_stop_stage = conn->stop_stage;
2431         conn->stop_stage = flag;
2432         conn->c_stage = ISCSI_CONN_STOPPED;
2433         spin_unlock_bh(&session->lock);
2434
2435         iscsi_suspend_tx(conn);
2436         /*
2437          * for connection level recovery we should not calculate
2438          * header digest. conn->hdr_size used for optimization
2439          * in hdr_extract() and will be re-negotiated at
2440          * set_param() time.
2441          */
2442         if (flag == STOP_CONN_RECOVER) {
2443                 conn->hdrdgst_en = 0;
2444                 conn->datadgst_en = 0;
2445                 if (session->state == ISCSI_STATE_IN_RECOVERY &&
2446                     old_stop_stage != STOP_CONN_RECOVER) {
2447                         debug_scsi("blocking session\n");
2448                         iscsi_block_session(session->cls_session);
2449                 }
2450         }
2451
2452         /*
2453          * flush queues.
2454          */
2455         spin_lock_bh(&session->lock);
2456         if (STOP_CONN_RECOVER)
2457                 fail_all_commands(conn, -1, DID_TRANSPORT_DISRUPTED);
2458         else
2459                 fail_all_commands(conn, -1, DID_ERROR);
2460         flush_control_queues(session, conn);
2461         spin_unlock_bh(&session->lock);
2462         mutex_unlock(&session->eh_mutex);
2463 }
2464
2465 void iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
2466 {
2467         struct iscsi_conn *conn = cls_conn->dd_data;
2468         struct iscsi_session *session = conn->session;
2469
2470         switch (flag) {
2471         case STOP_CONN_RECOVER:
2472         case STOP_CONN_TERM:
2473                 iscsi_start_session_recovery(session, conn, flag);
2474                 break;
2475         default:
2476                 iscsi_conn_printk(KERN_ERR, conn,
2477                                   "invalid stop flag %d\n", flag);
2478         }
2479 }
2480 EXPORT_SYMBOL_GPL(iscsi_conn_stop);
2481
2482 int iscsi_conn_bind(struct iscsi_cls_session *cls_session,
2483                     struct iscsi_cls_conn *cls_conn, int is_leading)
2484 {
2485         struct iscsi_session *session = cls_session->dd_data;
2486         struct iscsi_conn *conn = cls_conn->dd_data;
2487
2488         spin_lock_bh(&session->lock);
2489         if (is_leading)
2490                 session->leadconn = conn;
2491         spin_unlock_bh(&session->lock);
2492
2493         /*
2494          * Unblock xmitworker(), Login Phase will pass through.
2495          */
2496         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
2497         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
2498         return 0;
2499 }
2500 EXPORT_SYMBOL_GPL(iscsi_conn_bind);
2501
2502
2503 int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
2504                     enum iscsi_param param, char *buf, int buflen)
2505 {
2506         struct iscsi_conn *conn = cls_conn->dd_data;
2507         struct iscsi_session *session = conn->session;
2508         uint32_t value;
2509
2510         switch(param) {
2511         case ISCSI_PARAM_FAST_ABORT:
2512                 sscanf(buf, "%d", &session->fast_abort);
2513                 break;
2514         case ISCSI_PARAM_ABORT_TMO:
2515                 sscanf(buf, "%d", &session->abort_timeout);
2516                 break;
2517         case ISCSI_PARAM_LU_RESET_TMO:
2518                 sscanf(buf, "%d", &session->lu_reset_timeout);
2519                 break;
2520         case ISCSI_PARAM_PING_TMO:
2521                 sscanf(buf, "%d", &conn->ping_timeout);
2522                 break;
2523         case ISCSI_PARAM_RECV_TMO:
2524                 sscanf(buf, "%d", &conn->recv_timeout);
2525                 break;
2526         case ISCSI_PARAM_MAX_RECV_DLENGTH:
2527                 sscanf(buf, "%d", &conn->max_recv_dlength);
2528                 break;
2529         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
2530                 sscanf(buf, "%d", &conn->max_xmit_dlength);
2531                 break;
2532         case ISCSI_PARAM_HDRDGST_EN:
2533                 sscanf(buf, "%d", &conn->hdrdgst_en);
2534                 break;
2535         case ISCSI_PARAM_DATADGST_EN:
2536                 sscanf(buf, "%d", &conn->datadgst_en);
2537                 break;
2538         case ISCSI_PARAM_INITIAL_R2T_EN:
2539                 sscanf(buf, "%d", &session->initial_r2t_en);
2540                 break;
2541         case ISCSI_PARAM_MAX_R2T:
2542                 sscanf(buf, "%d", &session->max_r2t);
2543                 break;
2544         case ISCSI_PARAM_IMM_DATA_EN:
2545                 sscanf(buf, "%d", &session->imm_data_en);
2546                 break;
2547         case ISCSI_PARAM_FIRST_BURST:
2548                 sscanf(buf, "%d", &session->first_burst);
2549                 break;
2550         case ISCSI_PARAM_MAX_BURST:
2551                 sscanf(buf, "%d", &session->max_burst);
2552                 break;
2553         case ISCSI_PARAM_PDU_INORDER_EN:
2554                 sscanf(buf, "%d", &session->pdu_inorder_en);
2555                 break;
2556         case ISCSI_PARAM_DATASEQ_INORDER_EN:
2557                 sscanf(buf, "%d", &session->dataseq_inorder_en);
2558                 break;
2559         case ISCSI_PARAM_ERL:
2560                 sscanf(buf, "%d", &session->erl);
2561                 break;
2562         case ISCSI_PARAM_IFMARKER_EN:
2563                 sscanf(buf, "%d", &value);
2564                 BUG_ON(value);
2565                 break;
2566         case ISCSI_PARAM_OFMARKER_EN:
2567                 sscanf(buf, "%d", &value);
2568                 BUG_ON(value);
2569                 break;
2570         case ISCSI_PARAM_EXP_STATSN:
2571                 sscanf(buf, "%u", &conn->exp_statsn);
2572                 break;
2573         case ISCSI_PARAM_USERNAME:
2574                 kfree(session->username);
2575                 session->username = kstrdup(buf, GFP_KERNEL);
2576                 if (!session->username)
2577                         return -ENOMEM;
2578                 break;
2579         case ISCSI_PARAM_USERNAME_IN:
2580                 kfree(session->username_in);
2581                 session->username_in = kstrdup(buf, GFP_KERNEL);
2582                 if (!session->username_in)
2583                         return -ENOMEM;
2584                 break;
2585         case ISCSI_PARAM_PASSWORD:
2586                 kfree(session->password);
2587                 session->password = kstrdup(buf, GFP_KERNEL);
2588                 if (!session->password)
2589                         return -ENOMEM;
2590                 break;
2591         case ISCSI_PARAM_PASSWORD_IN:
2592                 kfree(session->password_in);
2593                 session->password_in = kstrdup(buf, GFP_KERNEL);
2594                 if (!session->password_in)
2595                         return -ENOMEM;
2596                 break;
2597         case ISCSI_PARAM_TARGET_NAME:
2598                 /* this should not change between logins */
2599                 if (session->targetname)
2600                         break;
2601
2602                 session->targetname = kstrdup(buf, GFP_KERNEL);
2603                 if (!session->targetname)
2604                         return -ENOMEM;
2605                 break;
2606         case ISCSI_PARAM_TPGT:
2607                 sscanf(buf, "%d", &session->tpgt);
2608                 break;
2609         case ISCSI_PARAM_PERSISTENT_PORT:
2610                 sscanf(buf, "%d", &conn->persistent_port);
2611                 break;
2612         case ISCSI_PARAM_PERSISTENT_ADDRESS:
2613                 /*
2614                  * this is the address returned in discovery so it should
2615                  * not change between logins.
2616                  */
2617                 if (conn->persistent_address)
2618                         break;
2619
2620                 conn->persistent_address = kstrdup(buf, GFP_KERNEL);
2621                 if (!conn->persistent_address)
2622                         return -ENOMEM;
2623                 break;
2624         case ISCSI_PARAM_IFACE_NAME:
2625                 if (!session->ifacename)
2626                         session->ifacename = kstrdup(buf, GFP_KERNEL);
2627                 break;
2628         case ISCSI_PARAM_INITIATOR_NAME:
2629                 if (!session->initiatorname)
2630                         session->initiatorname = kstrdup(buf, GFP_KERNEL);
2631                 break;
2632         default:
2633                 return -ENOSYS;
2634         }
2635
2636         return 0;
2637 }
2638 EXPORT_SYMBOL_GPL(iscsi_set_param);
2639
2640 int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
2641                             enum iscsi_param param, char *buf)
2642 {
2643         struct iscsi_session *session = cls_session->dd_data;
2644         int len;
2645
2646         switch(param) {
2647         case ISCSI_PARAM_FAST_ABORT:
2648                 len = sprintf(buf, "%d\n", session->fast_abort);
2649                 break;
2650         case ISCSI_PARAM_ABORT_TMO:
2651                 len = sprintf(buf, "%d\n", session->abort_timeout);
2652                 break;
2653         case ISCSI_PARAM_LU_RESET_TMO:
2654                 len = sprintf(buf, "%d\n", session->lu_reset_timeout);
2655                 break;
2656         case ISCSI_PARAM_INITIAL_R2T_EN:
2657                 len = sprintf(buf, "%d\n", session->initial_r2t_en);
2658                 break;
2659         case ISCSI_PARAM_MAX_R2T:
2660                 len = sprintf(buf, "%hu\n", session->max_r2t);
2661                 break;
2662         case ISCSI_PARAM_IMM_DATA_EN:
2663                 len = sprintf(buf, "%d\n", session->imm_data_en);
2664                 break;
2665         case ISCSI_PARAM_FIRST_BURST:
2666                 len = sprintf(buf, "%u\n", session->first_burst);
2667                 break;
2668         case ISCSI_PARAM_MAX_BURST:
2669                 len = sprintf(buf, "%u\n", session->max_burst);
2670                 break;
2671         case ISCSI_PARAM_PDU_INORDER_EN:
2672                 len = sprintf(buf, "%d\n", session->pdu_inorder_en);
2673                 break;
2674         case ISCSI_PARAM_DATASEQ_INORDER_EN:
2675                 len = sprintf(buf, "%d\n", session->dataseq_inorder_en);
2676                 break;
2677         case ISCSI_PARAM_ERL:
2678                 len = sprintf(buf, "%d\n", session->erl);
2679                 break;
2680         case ISCSI_PARAM_TARGET_NAME:
2681                 len = sprintf(buf, "%s\n", session->targetname);
2682                 break;
2683         case ISCSI_PARAM_TPGT:
2684                 len = sprintf(buf, "%d\n", session->tpgt);
2685                 break;
2686         case ISCSI_PARAM_USERNAME:
2687                 len = sprintf(buf, "%s\n", session->username);
2688                 break;
2689         case ISCSI_PARAM_USERNAME_IN:
2690                 len = sprintf(buf, "%s\n", session->username_in);
2691                 break;
2692         case ISCSI_PARAM_PASSWORD:
2693                 len = sprintf(buf, "%s\n", session->password);
2694                 break;
2695         case ISCSI_PARAM_PASSWORD_IN:
2696                 len = sprintf(buf, "%s\n", session->password_in);
2697                 break;
2698         case ISCSI_PARAM_IFACE_NAME:
2699                 len = sprintf(buf, "%s\n", session->ifacename);
2700                 break;
2701         case ISCSI_PARAM_INITIATOR_NAME:
2702                 if (!session->initiatorname)
2703                         len = sprintf(buf, "%s\n", "unknown");
2704                 else
2705                         len = sprintf(buf, "%s\n", session->initiatorname);
2706                 break;
2707         default:
2708                 return -ENOSYS;
2709         }
2710
2711         return len;
2712 }
2713 EXPORT_SYMBOL_GPL(iscsi_session_get_param);
2714
2715 int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
2716                          enum iscsi_param param, char *buf)
2717 {
2718         struct iscsi_conn *conn = cls_conn->dd_data;
2719         int len;
2720
2721         switch(param) {
2722         case ISCSI_PARAM_PING_TMO:
2723                 len = sprintf(buf, "%u\n", conn->ping_timeout);
2724                 break;
2725         case ISCSI_PARAM_RECV_TMO:
2726                 len = sprintf(buf, "%u\n", conn->recv_timeout);
2727                 break;
2728         case ISCSI_PARAM_MAX_RECV_DLENGTH:
2729                 len = sprintf(buf, "%u\n", conn->max_recv_dlength);
2730                 break;
2731         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
2732                 len = sprintf(buf, "%u\n", conn->max_xmit_dlength);
2733                 break;
2734         case ISCSI_PARAM_HDRDGST_EN:
2735                 len = sprintf(buf, "%d\n", conn->hdrdgst_en);
2736                 break;
2737         case ISCSI_PARAM_DATADGST_EN:
2738                 len = sprintf(buf, "%d\n", conn->datadgst_en);
2739                 break;
2740         case ISCSI_PARAM_IFMARKER_EN:
2741                 len = sprintf(buf, "%d\n", conn->ifmarker_en);
2742                 break;
2743         case ISCSI_PARAM_OFMARKER_EN:
2744                 len = sprintf(buf, "%d\n", conn->ofmarker_en);
2745                 break;
2746         case ISCSI_PARAM_EXP_STATSN:
2747                 len = sprintf(buf, "%u\n", conn->exp_statsn);
2748                 break;
2749         case ISCSI_PARAM_PERSISTENT_PORT:
2750                 len = sprintf(buf, "%d\n", conn->persistent_port);
2751                 break;
2752         case ISCSI_PARAM_PERSISTENT_ADDRESS:
2753                 len = sprintf(buf, "%s\n", conn->persistent_address);
2754                 break;
2755         default:
2756                 return -ENOSYS;
2757         }
2758
2759         return len;
2760 }
2761 EXPORT_SYMBOL_GPL(iscsi_conn_get_param);
2762
2763 int iscsi_host_get_param(struct Scsi_Host *shost, enum iscsi_host_param param,
2764                          char *buf)
2765 {
2766         struct iscsi_host *ihost = shost_priv(shost);
2767         int len;
2768
2769         switch (param) {
2770         case ISCSI_HOST_PARAM_NETDEV_NAME:
2771                 if (!ihost->netdev)
2772                         len = sprintf(buf, "%s\n", "default");
2773                 else
2774                         len = sprintf(buf, "%s\n", ihost->netdev);
2775                 break;
2776         case ISCSI_HOST_PARAM_HWADDRESS:
2777                 if (!ihost->hwaddress)
2778                         len = sprintf(buf, "%s\n", "default");
2779                 else
2780                         len = sprintf(buf, "%s\n", ihost->hwaddress);
2781                 break;
2782         case ISCSI_HOST_PARAM_INITIATOR_NAME:
2783                 if (!ihost->initiatorname)
2784                         len = sprintf(buf, "%s\n", "unknown");
2785                 else
2786                         len = sprintf(buf, "%s\n", ihost->initiatorname);
2787                 break;
2788         case ISCSI_HOST_PARAM_IPADDRESS:
2789                 if (!strlen(ihost->local_address))
2790                         len = sprintf(buf, "%s\n", "unknown");
2791                 else
2792                         len = sprintf(buf, "%s\n",
2793                                       ihost->local_address);
2794                 break;
2795         default:
2796                 return -ENOSYS;
2797         }
2798
2799         return len;
2800 }
2801 EXPORT_SYMBOL_GPL(iscsi_host_get_param);
2802
2803 int iscsi_host_set_param(struct Scsi_Host *shost, enum iscsi_host_param param,
2804                          char *buf, int buflen)
2805 {
2806         struct iscsi_host *ihost = shost_priv(shost);
2807
2808         switch (param) {
2809         case ISCSI_HOST_PARAM_NETDEV_NAME:
2810                 if (!ihost->netdev)
2811                         ihost->netdev = kstrdup(buf, GFP_KERNEL);
2812                 break;
2813         case ISCSI_HOST_PARAM_HWADDRESS:
2814                 if (!ihost->hwaddress)
2815                         ihost->hwaddress = kstrdup(buf, GFP_KERNEL);
2816                 break;
2817         case ISCSI_HOST_PARAM_INITIATOR_NAME:
2818                 if (!ihost->initiatorname)
2819                         ihost->initiatorname = kstrdup(buf, GFP_KERNEL);
2820                 break;
2821         default:
2822                 return -ENOSYS;
2823         }
2824
2825         return 0;
2826 }
2827 EXPORT_SYMBOL_GPL(iscsi_host_set_param);
2828
2829 MODULE_AUTHOR("Mike Christie");
2830 MODULE_DESCRIPTION("iSCSI library functions");
2831 MODULE_LICENSE("GPL");