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 /**
  92  * iscsi_prep_data_out_pdu - initialize Data-Out
  93  * @task: scsi command task
  94  * @r2t: R2T info
  95  * @hdr: iscsi data in pdu
  96  *
  97  * Notes:
  98  *      Initialize Data-Out within this R2T sequence and finds
  99  *      proper data_offset within this SCSI command.
 100  *
 101  *      This function is called with connection lock taken.
 102  **/
 103 void iscsi_prep_data_out_pdu(struct iscsi_task *task, struct iscsi_r2t_info *r2t,
 104                            struct iscsi_data *hdr)
 105 {
 106         struct iscsi_conn *conn = task->conn;
 107         unsigned int left = r2t->data_length - r2t->sent;
 108
 109         task->hdr_len = sizeof(struct iscsi_data);
 110
 111         memset(hdr, 0, sizeof(struct iscsi_data));
 112         hdr->ttt = r2t->ttt;
 113         hdr->datasn = cpu_to_be32(r2t->datasn);
 114         r2t->datasn++;
 115         hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
 116         memcpy(hdr->lun, task->lun, sizeof(hdr->lun));
 117         hdr->itt = task->hdr_itt;
 118         hdr->exp_statsn = r2t->exp_statsn;
 119         hdr->offset = cpu_to_be32(r2t->data_offset + r2t->sent);
 120         if (left > conn->max_xmit_dlength) {
 121                 hton24(hdr->dlength, conn->max_xmit_dlength);
 122                 r2t->data_count = conn->max_xmit_dlength;
 123                 hdr->flags = 0;
 124         } else {
 125                 hton24(hdr->dlength, left);
 126                 r2t->data_count = left;
 127                 hdr->flags = ISCSI_FLAG_CMD_FINAL;
 128         }
 129         conn->dataout_pdus_cnt++;
 130 }
 131 EXPORT_SYMBOL_GPL(iscsi_prep_data_out_pdu);
 132
 133 static int iscsi_add_hdr(struct iscsi_task *task, unsigned len)
 134 {
 135         unsigned exp_len = task->hdr_len + len;
 136
 137         if (exp_len > task->hdr_max) {
 138                 WARN_ON(1);
 139                 return -EINVAL;
 140         }
 141
 142         WARN_ON(len & (ISCSI_PAD_LEN - 1)); /* caller must pad the AHS */
 143         task->hdr_len = exp_len;
 144         return 0;
 145 }
 146
 147 /*
 148  * make an extended cdb AHS
 149  */
 150 static int iscsi_prep_ecdb_ahs(struct iscsi_task *task)
 151 {
 152         struct scsi_cmnd *cmd = task->sc;
 153         unsigned rlen, pad_len;
 154         unsigned short ahslength;
 155         struct iscsi_ecdb_ahdr *ecdb_ahdr;
 156         int rc;
 157
 158         ecdb_ahdr = iscsi_next_hdr(task);
 159         rlen = cmd->cmd_len - ISCSI_CDB_SIZE;
 160
 161         BUG_ON(rlen > sizeof(ecdb_ahdr->ecdb));
 162         ahslength = rlen + sizeof(ecdb_ahdr->reserved);
 163
 164         pad_len = iscsi_padding(rlen);
 165
 166         rc = iscsi_add_hdr(task, sizeof(ecdb_ahdr->ahslength) +
 167                            sizeof(ecdb_ahdr->ahstype) + ahslength + pad_len);
 168         if (rc)
 169                 return rc;
 170
 171         if (pad_len)
 172                 memset(&ecdb_ahdr->ecdb[rlen], 0, pad_len);
 173
 174         ecdb_ahdr->ahslength = cpu_to_be16(ahslength);
 175         ecdb_ahdr->ahstype = ISCSI_AHSTYPE_CDB;
 176         ecdb_ahdr->reserved = 0;
 177         memcpy(ecdb_ahdr->ecdb, cmd->cmnd + ISCSI_CDB_SIZE, rlen);
 178
 179         debug_scsi("iscsi_prep_ecdb_ahs: varlen_cdb_len %d "
 180                    "rlen %d pad_len %d ahs_length %d iscsi_headers_size %u\n",
 181                    cmd->cmd_len, rlen, pad_len, ahslength, task->hdr_len);
 182
 183         return 0;
 184 }
 185
 186 static int iscsi_prep_bidi_ahs(struct iscsi_task *task)
 187 {
 188         struct scsi_cmnd *sc = task->sc;
 189         struct iscsi_rlength_ahdr *rlen_ahdr;
 190         int rc;
 191
 192         rlen_ahdr = iscsi_next_hdr(task);
 193         rc = iscsi_add_hdr(task, sizeof(*rlen_ahdr));
 194         if (rc)
 195                 return rc;
 196
 197         rlen_ahdr->ahslength =
 198                 cpu_to_be16(sizeof(rlen_ahdr->read_length) +
 199                                                   sizeof(rlen_ahdr->reserved));
 200         rlen_ahdr->ahstype = ISCSI_AHSTYPE_RLENGTH;
 201         rlen_ahdr->reserved = 0;
 202         rlen_ahdr->read_length = cpu_to_be32(scsi_in(sc)->length);
 203
 204         debug_scsi("bidi-in rlen_ahdr->read_length(%d) "
 205                    "rlen_ahdr->ahslength(%d)\n",
 206                    be32_to_cpu(rlen_ahdr->read_length),
 207                    be16_to_cpu(rlen_ahdr->ahslength));
 208         return 0;
 209 }
 210
 211 /**
 212  * iscsi_prep_scsi_cmd_pdu - prep iscsi scsi cmd pdu
 213  * @task: iscsi task
 214  *
 215  * Prep basic iSCSI PDU fields for a scsi cmd pdu. The LLD should set
 216  * fields like dlength or final based on how much data it sends
 217  */
 218 static int iscsi_prep_scsi_cmd_pdu(struct iscsi_task *task)
 219 {
 220         struct iscsi_conn *conn = task->conn;
 221         struct iscsi_session *session = conn->session;
 222         struct scsi_cmnd *sc = task->sc;
 223         struct iscsi_cmd *hdr;
 224         unsigned hdrlength, cmd_len;
 225         itt_t itt;
 226         int rc;
 227
 228         rc = conn->session->tt->alloc_pdu(task, ISCSI_OP_SCSI_CMD);
 229         if (rc)
 230                 return rc;
 231         hdr = (struct iscsi_cmd *) task->hdr;
 232         itt = hdr->itt;
 233         memset(hdr, 0, sizeof(*hdr));
 234
 235         if (session->tt->parse_pdu_itt)
 236                 hdr->itt = task->hdr_itt = itt;
 237         else
 238                 hdr->itt = task->hdr_itt = build_itt(task->itt,
 239                                                      task->conn->session->age);
 240         task->hdr_len = 0;
 241         rc = iscsi_add_hdr(task, sizeof(*hdr));
 242         if (rc)
 243                 return rc;
 244         hdr->opcode = ISCSI_OP_SCSI_CMD;
 245         hdr->flags = ISCSI_ATTR_SIMPLE;
 246         int_to_scsilun(sc->device->lun, (struct scsi_lun *)hdr->lun);
 247         memcpy(task->lun, hdr->lun, sizeof(task->lun));
 248         hdr->cmdsn = task->cmdsn = cpu_to_be32(session->cmdsn);
 249         session->cmdsn++;
 250         hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
 251         cmd_len = sc->cmd_len;
 252         if (cmd_len < ISCSI_CDB_SIZE)
 253                 memset(&hdr->cdb[cmd_len], 0, ISCSI_CDB_SIZE - cmd_len);
 254         else if (cmd_len > ISCSI_CDB_SIZE) {
 255                 rc = iscsi_prep_ecdb_ahs(task);
 256                 if (rc)
 257                         return rc;
 258                 cmd_len = ISCSI_CDB_SIZE;
 259         }
 260         memcpy(hdr->cdb, sc->cmnd, cmd_len);
 261
 262         task->imm_count = 0;
 263         if (scsi_bidi_cmnd(sc)) {
 264                 hdr->flags |= ISCSI_FLAG_CMD_READ;
 265                 rc = iscsi_prep_bidi_ahs(task);
 266                 if (rc)
 267                         return rc;
 268         }
 269         if (sc->sc_data_direction == DMA_TO_DEVICE) {
 270                 unsigned out_len = scsi_out(sc)->length;
 271                 struct iscsi_r2t_info *r2t = &task->unsol_r2t;
 272
 273                 hdr->data_length = cpu_to_be32(out_len);
 274                 hdr->flags |= ISCSI_FLAG_CMD_WRITE;
 275                 /*
 276                  * Write counters:
 277                  *
 278                  *      imm_count       bytes to be sent right after
 279                  *                      SCSI PDU Header
 280                  *
 281                  *      unsol_count     bytes(as Data-Out) to be sent
 282                  *                      without R2T ack right after
 283                  *                      immediate data
 284                  *
 285                  *      r2t data_length bytes to be sent via R2T ack's
 286                  *
 287                  *      pad_count       bytes to be sent as zero-padding
 288                  */
 289                 memset(r2t, 0, sizeof(*r2t));
 290
 291                 if (session->imm_data_en) {
 292                         if (out_len >= session->first_burst)
 293                                 task->imm_count = min(session->first_burst,
 294                                                         conn->max_xmit_dlength);
 295                         else
 296                                 task->imm_count = min(out_len,
 297                                                         conn->max_xmit_dlength);
 298                         hton24(hdr->dlength, task->imm_count);
 299                 } else
 300                         zero_data(hdr->dlength);
 301
 302                 if (!session->initial_r2t_en) {
 303                         r2t->data_length = min(session->first_burst, out_len) -
 304                                                task->imm_count;
 305                         r2t->data_offset = task->imm_count;
 306                         r2t->ttt = cpu_to_be32(ISCSI_RESERVED_TAG);
 307                         r2t->exp_statsn = cpu_to_be32(conn->exp_statsn);
 308                 }
 309
 310                 if (!task->unsol_r2t.data_length)
 311                         /* No unsolicit Data-Out's */
 312                         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
 313         } else {
 314                 hdr->flags |= ISCSI_FLAG_CMD_FINAL;
 315                 zero_data(hdr->dlength);
 316                 hdr->data_length = cpu_to_be32(scsi_in(sc)->length);
 317
 318                 if (sc->sc_data_direction == DMA_FROM_DEVICE)
 319                         hdr->flags |= ISCSI_FLAG_CMD_READ;
 320         }
 321
 322         /* calculate size of additional header segments (AHSs) */
 323         hdrlength = task->hdr_len - sizeof(*hdr);
 324
 325         WARN_ON(hdrlength & (ISCSI_PAD_LEN-1));
 326         hdrlength /= ISCSI_PAD_LEN;
 327
 328         WARN_ON(hdrlength >= 256);
 329         hdr->hlength = hdrlength & 0xFF;
 330
 331         if (session->tt->init_task && session->tt->init_task(task))
 332                 return -EIO;
 333
 334         task->state = ISCSI_TASK_RUNNING;
 335         list_move_tail(&task->running, &conn->run_list);
 336
 337         conn->scsicmd_pdus_cnt++;
 338         debug_scsi("iscsi prep [%s cid %d sc %p cdb 0x%x itt 0x%x len %d "
 339                    "bidi_len %d cmdsn %d win %d]\n", scsi_bidi_cmnd(sc) ?
 340                    "bidirectional" : sc->sc_data_direction == DMA_TO_DEVICE ?
 341                    "write" : "read", conn->id, sc, sc->cmnd[0], task->itt,
 342                    scsi_bufflen(sc),
 343                    scsi_bidi_cmnd(sc) ? scsi_in(sc)->length : 0,
 344                    session->cmdsn, session->max_cmdsn - session->exp_cmdsn + 1);
 345         return 0;
 346 }
 347
 348 /**
 349  * iscsi_complete_command - finish a task
 350  * @task: iscsi cmd task
 351  *
 352  * Must be called with session lock.
 353  * This function returns the scsi command to scsi-ml or cleans
 354  * up mgmt tasks then returns the task to the pool.
 355  */
 356 static void iscsi_complete_command(struct iscsi_task *task)
 357 {
 358         struct iscsi_conn *conn = task->conn;
 359         struct iscsi_session *session = conn->session;
 360         struct scsi_cmnd *sc = task->sc;
 361
 362         session->tt->cleanup_task(task);
 363         list_del_init(&task->running);
 364         task->state = ISCSI_TASK_COMPLETED;
 365         task->sc = NULL;
 366
 367         if (conn->task == task)
 368                 conn->task = NULL;
 369         /*
 370          * login task is preallocated so do not free
 371          */
 372         if (conn->login_task == task)
 373                 return;
 374
 375         __kfifo_put(session->cmdpool.queue, (void*)&task, sizeof(void*));
 376
 377         if (conn->ping_task == task)
 378                 conn->ping_task = NULL;
 379
 380         if (sc) {
 381                 task->sc = NULL;
 382                 /* SCSI eh reuses commands to verify us */
 383                 sc->SCp.ptr = NULL;
 384                 /*
 385                  * queue command may call this to free the task, but
 386                  * not have setup the sc callback
 387                  */
 388                 if (sc->scsi_done)
 389                         sc->scsi_done(sc);
 390         }
 391 }
 392
 393 void __iscsi_get_task(struct iscsi_task *task)
 394 {
 395         atomic_inc(&task->refcount);
 396 }
 397 EXPORT_SYMBOL_GPL(__iscsi_get_task);
 398
 399 static void __iscsi_put_task(struct iscsi_task *task)
 400 {
 401         if (atomic_dec_and_test(&task->refcount))
 402                 iscsi_complete_command(task);
 403 }
 404
 405 void iscsi_put_task(struct iscsi_task *task)
 406 {
 407         struct iscsi_session *session = task->conn->session;
 408
 409         spin_lock_bh(&session->lock);
 410         __iscsi_put_task(task);
 411         spin_unlock_bh(&session->lock);
 412 }
 413 EXPORT_SYMBOL_GPL(iscsi_put_task);
 414
 415 /*
 416  * session lock must be held
 417  */
 418 static void fail_command(struct iscsi_conn *conn, struct iscsi_task *task,
 419                          int err)
 420 {
 421         struct scsi_cmnd *sc;
 422
 423         sc = task->sc;
 424         if (!sc)
 425                 return;
 426
 427         if (task->state == ISCSI_TASK_PENDING)
 428                 /*
 429                  * cmd never made it to the xmit thread, so we should not count
 430                  * the cmd in the sequencing
 431                  */
 432                 conn->session->queued_cmdsn--;
 433
 434         sc->result = err;
 435         if (!scsi_bidi_cmnd(sc))
 436                 scsi_set_resid(sc, scsi_bufflen(sc));
 437         else {
 438                 scsi_out(sc)->resid = scsi_out(sc)->length;
 439                 scsi_in(sc)->resid = scsi_in(sc)->length;
 440         }
 441
 442         if (conn->task == task)
 443                 conn->task = NULL;
 444         /* release ref from queuecommand */
 445         __iscsi_put_task(task);
 446 }
 447
 448 static int iscsi_prep_mgmt_task(struct iscsi_conn *conn,
 449                                 struct iscsi_task *task)
 450 {
 451         struct iscsi_session *session = conn->session;
 452         struct iscsi_hdr *hdr = task->hdr;
 453         struct iscsi_nopout *nop = (struct iscsi_nopout *)hdr;
 454
 455         if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
 456                 return -ENOTCONN;
 457
 458         if (hdr->opcode != (ISCSI_OP_LOGIN | ISCSI_OP_IMMEDIATE) &&
 459             hdr->opcode != (ISCSI_OP_TEXT | ISCSI_OP_IMMEDIATE))
 460                 nop->exp_statsn = cpu_to_be32(conn->exp_statsn);
 461         /*
 462          * pre-format CmdSN for outgoing PDU.
 463          */
 464         nop->cmdsn = cpu_to_be32(session->cmdsn);
 465         if (hdr->itt != RESERVED_ITT) {
 466                 /*
 467                  * TODO: We always use immediate, so we never hit this.
 468                  * If we start to send tmfs or nops as non-immediate then
 469                  * we should start checking the cmdsn numbers for mgmt tasks.
 470                  */
 471                 if (conn->c_stage == ISCSI_CONN_STARTED &&
 472                     !(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
 473                         session->queued_cmdsn++;
 474                         session->cmdsn++;
 475                 }
 476         }
 477
 478         if (session->tt->init_task && session->tt->init_task(task))
 479                 return -EIO;
 480
 481         if ((hdr->opcode & ISCSI_OPCODE_MASK) == ISCSI_OP_LOGOUT)
 482                 session->state = ISCSI_STATE_LOGGING_OUT;
 483
 484         task->state = ISCSI_TASK_RUNNING;
 485         list_move_tail(&task->running, &conn->mgmt_run_list);
 486         debug_scsi("mgmtpdu [op 0x%x hdr->itt 0x%x datalen %d]\n",
 487                    hdr->opcode & ISCSI_OPCODE_MASK, hdr->itt,
 488                    task->data_count);
 489         return 0;
 490 }
 491
 492 static struct iscsi_task *
 493 __iscsi_conn_send_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 494                       char *data, uint32_t data_size)
 495 {
 496         struct iscsi_session *session = conn->session;
 497         struct iscsi_task *task;
 498         itt_t itt;
 499
 500         if (session->state == ISCSI_STATE_TERMINATE)
 501                 return NULL;
 502
 503         if (hdr->opcode == (ISCSI_OP_LOGIN | ISCSI_OP_IMMEDIATE) ||
 504             hdr->opcode == (ISCSI_OP_TEXT | ISCSI_OP_IMMEDIATE))
 505                 /*
 506                  * Login and Text are sent serially, in
 507                  * request-followed-by-response sequence.
 508                  * Same task can be used. Same ITT must be used.
 509                  * Note that login_task is preallocated at conn_create().
 510                  */
 511                 task = conn->login_task;
 512         else {
 513                 BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
 514                 BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);
 515
 516                 if (!__kfifo_get(session->cmdpool.queue,
 517                                  (void*)&task, sizeof(void*)))
 518                         return NULL;
 519         }
 520         /*
 521          * released in complete pdu for task we expect a response for, and
 522          * released by the lld when it has transmitted the task for
 523          * pdus we do not expect a response for.
 524          */
 525         atomic_set(&task->refcount, 1);
 526         task->conn = conn;
 527         task->sc = NULL;
 528
 529         if (data_size) {
 530                 memcpy(task->data, data, data_size);
 531                 task->data_count = data_size;
 532         } else
 533                 task->data_count = 0;
 534
 535         if (conn->session->tt->alloc_pdu(task, hdr->opcode)) {
 536                 iscsi_conn_printk(KERN_ERR, conn, "Could not allocate "
 537                                  "pdu for mgmt task.\n");
 538                 goto requeue_task;
 539         }
 540         itt = task->hdr->itt;
 541         task->hdr_len = sizeof(struct iscsi_hdr);
 542         memcpy(task->hdr, hdr, sizeof(struct iscsi_hdr));
 543
 544         if (hdr->itt != RESERVED_ITT) {
 545                 if (session->tt->parse_pdu_itt)
 546                         task->hdr->itt = itt;
 547                 else
 548                         task->hdr->itt = build_itt(task->itt,
 549                                                    task->conn->session->age);
 550         }
 551
 552         INIT_LIST_HEAD(&task->running);
 553         list_add_tail(&task->running, &conn->mgmtqueue);
 554
 555         if (session->tt->caps & CAP_DATA_PATH_OFFLOAD) {
 556                 if (iscsi_prep_mgmt_task(conn, task))
 557                         goto free_task;
 558
 559                 if (session->tt->xmit_task(task))
 560                         goto free_task;
 561
 562         } else
 563                 scsi_queue_work(conn->session->host, &conn->xmitwork);
 564
 565         return task;
 566
 567 free_task:
 568         __iscsi_put_task(task);
 569         return NULL;
 570
 571 requeue_task:
 572         if (task != conn->login_task)
 573                 __kfifo_put(session->cmdpool.queue, (void*)&task,
 574                             sizeof(void*));
 575         return NULL;
 576 }
 577
 578 int iscsi_conn_send_pdu(struct iscsi_cls_conn *cls_conn, struct iscsi_hdr *hdr,
 579                         char *data, uint32_t data_size)
 580 {
 581         struct iscsi_conn *conn = cls_conn->dd_data;
 582         struct iscsi_session *session = conn->session;
 583         int err = 0;
 584
 585         spin_lock_bh(&session->lock);
 586         if (!__iscsi_conn_send_pdu(conn, hdr, data, data_size))
 587                 err = -EPERM;
 588         spin_unlock_bh(&session->lock);
 589         return err;
 590 }
 591 EXPORT_SYMBOL_GPL(iscsi_conn_send_pdu);
 592
 593 /**
 594  * iscsi_cmd_rsp - SCSI Command Response processing
 595  * @conn: iscsi connection
 596  * @hdr: iscsi header
 597  * @task: scsi command task
 598  * @data: cmd data buffer
 599  * @datalen: len of buffer
 600  *
 601  * iscsi_cmd_rsp sets up the scsi_cmnd fields based on the PDU and
 602  * then completes the command and task.
 603  **/
 604 static void iscsi_scsi_cmd_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 605                                struct iscsi_task *task, char *data,
 606                                int datalen)
 607 {
 608         struct iscsi_cmd_rsp *rhdr = (struct iscsi_cmd_rsp *)hdr;
 609         struct iscsi_session *session = conn->session;
 610         struct scsi_cmnd *sc = task->sc;
 611
 612         iscsi_update_cmdsn(session, (struct iscsi_nopin*)rhdr);
 613         conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 614
 615         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 616
 617         if (rhdr->response != ISCSI_STATUS_CMD_COMPLETED) {
 618                 sc->result = DID_ERROR << 16;
 619                 goto out;
 620         }
 621
 622         if (rhdr->cmd_status == SAM_STAT_CHECK_CONDITION) {
 623                 uint16_t senselen;
 624
 625                 if (datalen < 2) {
 626 invalid_datalen:
 627                         iscsi_conn_printk(KERN_ERR,  conn,
 628                                          "Got CHECK_CONDITION but invalid data "
 629                                          "buffer size of %d\n", datalen);
 630                         sc->result = DID_BAD_TARGET << 16;
 631                         goto out;
 632                 }
 633
 634                 senselen = get_unaligned_be16(data);
 635                 if (datalen < senselen)
 636                         goto invalid_datalen;
 637
 638                 memcpy(sc->sense_buffer, data + 2,
 639                        min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
 640                 debug_scsi("copied %d bytes of sense\n",
 641                            min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
 642         }
 643
 644         if (rhdr->flags & (ISCSI_FLAG_CMD_BIDI_UNDERFLOW |
 645                            ISCSI_FLAG_CMD_BIDI_OVERFLOW)) {
 646                 int res_count = be32_to_cpu(rhdr->bi_residual_count);
 647
 648                 if (scsi_bidi_cmnd(sc) && res_count > 0 &&
 649                                 (rhdr->flags & ISCSI_FLAG_CMD_BIDI_OVERFLOW ||
 650                                  res_count <= scsi_in(sc)->length))
 651                         scsi_in(sc)->resid = res_count;
 652                 else
 653                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 654         }
 655
 656         if (rhdr->flags & (ISCSI_FLAG_CMD_UNDERFLOW |
 657                            ISCSI_FLAG_CMD_OVERFLOW)) {
 658                 int res_count = be32_to_cpu(rhdr->residual_count);
 659
 660                 if (res_count > 0 &&
 661                     (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
 662                      res_count <= scsi_bufflen(sc)))
 663                         /* write side for bidi or uni-io set_resid */
 664                         scsi_set_resid(sc, res_count);
 665                 else
 666                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 667         }
 668 out:
 669         debug_scsi("done [sc %lx res %d itt 0x%x]\n",
 670                    (long)sc, sc->result, task->itt);
 671         conn->scsirsp_pdus_cnt++;
 672
 673         __iscsi_put_task(task);
 674 }
 675
 676 /**
 677  * iscsi_data_in_rsp - SCSI Data-In Response processing
 678  * @conn: iscsi connection
 679  * @hdr:  iscsi pdu
 680  * @task: scsi command task
 681  **/
 682 static void
 683 iscsi_data_in_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 684                   struct iscsi_task *task)
 685 {
 686         struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)hdr;
 687         struct scsi_cmnd *sc = task->sc;
 688
 689         if (!(rhdr->flags & ISCSI_FLAG_DATA_STATUS))
 690                 return;
 691
 692         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 693         conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 694         if (rhdr->flags & (ISCSI_FLAG_DATA_UNDERFLOW |
 695                            ISCSI_FLAG_DATA_OVERFLOW)) {
 696                 int res_count = be32_to_cpu(rhdr->residual_count);
 697
 698                 if (res_count > 0 &&
 699                     (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
 700                      res_count <= scsi_in(sc)->length))
 701                         scsi_in(sc)->resid = res_count;
 702                 else
 703                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 704         }
 705
 706         conn->scsirsp_pdus_cnt++;
 707         __iscsi_put_task(task);
 708 }
 709
 710 static void iscsi_tmf_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
 711 {
 712         struct iscsi_tm_rsp *tmf = (struct iscsi_tm_rsp *)hdr;
 713
 714         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 715         conn->tmfrsp_pdus_cnt++;
 716
 717         if (conn->tmf_state != TMF_QUEUED)
 718                 return;
 719
 720         if (tmf->response == ISCSI_TMF_RSP_COMPLETE)
 721                 conn->tmf_state = TMF_SUCCESS;
 722         else if (tmf->response == ISCSI_TMF_RSP_NO_TASK)
 723                 conn->tmf_state = TMF_NOT_FOUND;
 724         else
 725                 conn->tmf_state = TMF_FAILED;
 726         wake_up(&conn->ehwait);
 727 }
 728
 729 static void iscsi_send_nopout(struct iscsi_conn *conn, struct iscsi_nopin *rhdr)
 730 {
 731         struct iscsi_nopout hdr;
 732         struct iscsi_task *task;
 733
 734         if (!rhdr && conn->ping_task)
 735                 return;
 736
 737         memset(&hdr, 0, sizeof(struct iscsi_nopout));
 738         hdr.opcode = ISCSI_OP_NOOP_OUT | ISCSI_OP_IMMEDIATE;
 739         hdr.flags = ISCSI_FLAG_CMD_FINAL;
 740
 741         if (rhdr) {
 742                 memcpy(hdr.lun, rhdr->lun, 8);
 743                 hdr.ttt = rhdr->ttt;
 744                 hdr.itt = RESERVED_ITT;
 745         } else
 746                 hdr.ttt = RESERVED_ITT;
 747
 748         task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)&hdr, NULL, 0);
 749         if (!task)
 750                 iscsi_conn_printk(KERN_ERR, conn, "Could not send nopout\n");
 751         else if (!rhdr) {
 752                 /* only track our nops */
 753                 conn->ping_task = task;
 754                 conn->last_ping = jiffies;
 755         }
 756 }
 757
 758 static int iscsi_handle_reject(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 759                                char *data, int datalen)
 760 {
 761         struct iscsi_reject *reject = (struct iscsi_reject *)hdr;
 762         struct iscsi_hdr rejected_pdu;
 763
 764         conn->exp_statsn = be32_to_cpu(reject->statsn) + 1;
 765
 766         if (reject->reason == ISCSI_REASON_DATA_DIGEST_ERROR) {
 767                 if (ntoh24(reject->dlength) > datalen)
 768                         return ISCSI_ERR_PROTO;
 769
 770                 if (ntoh24(reject->dlength) >= sizeof(struct iscsi_hdr)) {
 771                         memcpy(&rejected_pdu, data, sizeof(struct iscsi_hdr));
 772                         iscsi_conn_printk(KERN_ERR, conn,
 773                                           "pdu (op 0x%x) rejected "
 774                                           "due to DataDigest error.\n",
 775                                           rejected_pdu.opcode);
 776                 }
 777         }
 778         return 0;
 779 }
 780
 781 /**
 782  * iscsi_itt_to_task - look up task by itt
 783  * @conn: iscsi connection
 784  * @itt: itt
 785  *
 786  * This should be used for mgmt tasks like login and nops, or if
 787  * the LDD's itt space does not include the session age.
 788  *
 789  * The session lock must be held.
 790  */
 791 static struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *conn, itt_t itt)
 792 {
 793         struct iscsi_session *session = conn->session;
 794         int i;
 795
 796         if (itt == RESERVED_ITT)
 797                 return NULL;
 798
 799         if (session->tt->parse_pdu_itt)
 800                 session->tt->parse_pdu_itt(conn, itt, &i, NULL);
 801         else
 802                 i = get_itt(itt);
 803         if (i >= session->cmds_max)
 804                 return NULL;
 805
 806         return session->cmds[i];
 807 }
 808
 809 /**
 810  * __iscsi_complete_pdu - complete pdu
 811  * @conn: iscsi conn
 812  * @hdr: iscsi header
 813  * @data: data buffer
 814  * @datalen: len of data buffer
 815  *
 816  * Completes pdu processing by freeing any resources allocated at
 817  * queuecommand or send generic. session lock must be held and verify
 818  * itt must have been called.
 819  */
 820 int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 821                          char *data, int datalen)
 822 {
 823         struct iscsi_session *session = conn->session;
 824         int opcode = hdr->opcode & ISCSI_OPCODE_MASK, rc = 0;
 825         struct iscsi_task *task;
 826         uint32_t itt;
 827
 828         conn->last_recv = jiffies;
 829         rc = iscsi_verify_itt(conn, hdr->itt);
 830         if (rc)
 831                 return rc;
 832
 833         if (hdr->itt != RESERVED_ITT)
 834                 itt = get_itt(hdr->itt);
 835         else
 836                 itt = ~0U;
 837
 838         debug_scsi("[op 0x%x cid %d itt 0x%x len %d]\n",
 839                    opcode, conn->id, itt, datalen);
 840
 841         if (itt == ~0U) {
 842                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
 843
 844                 switch(opcode) {
 845                 case ISCSI_OP_NOOP_IN:
 846                         if (datalen) {
 847                                 rc = ISCSI_ERR_PROTO;
 848                                 break;
 849                         }
 850
 851                         if (hdr->ttt == cpu_to_be32(ISCSI_RESERVED_TAG))
 852                                 break;
 853
 854                         iscsi_send_nopout(conn, (struct iscsi_nopin*)hdr);
 855                         break;
 856                 case ISCSI_OP_REJECT:
 857                         rc = iscsi_handle_reject(conn, hdr, data, datalen);
 858                         break;
 859                 case ISCSI_OP_ASYNC_EVENT:
 860                         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 861                         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
 862                                 rc = ISCSI_ERR_CONN_FAILED;
 863                         break;
 864                 default:
 865                         rc = ISCSI_ERR_BAD_OPCODE;
 866                         break;
 867                 }
 868                 goto out;
 869         }
 870
 871         switch(opcode) {
 872         case ISCSI_OP_SCSI_CMD_RSP:
 873         case ISCSI_OP_SCSI_DATA_IN:
 874                 task = iscsi_itt_to_ctask(conn, hdr->itt);
 875                 if (!task)
 876                         return ISCSI_ERR_BAD_ITT;
 877                 break;
 878         case ISCSI_OP_R2T:
 879                 /*
 880                  * LLD handles R2Ts if they need to.
 881                  */
 882                 return 0;
 883         case ISCSI_OP_LOGOUT_RSP:
 884         case ISCSI_OP_LOGIN_RSP:
 885         case ISCSI_OP_TEXT_RSP:
 886         case ISCSI_OP_SCSI_TMFUNC_RSP:
 887         case ISCSI_OP_NOOP_IN:
 888                 task = iscsi_itt_to_task(conn, hdr->itt);
 889                 if (!task)
 890                         return ISCSI_ERR_BAD_ITT;
 891                 break;
 892         default:
 893                 return ISCSI_ERR_BAD_OPCODE;
 894         }
 895
 896         switch(opcode) {
 897         case ISCSI_OP_SCSI_CMD_RSP:
 898                 iscsi_scsi_cmd_rsp(conn, hdr, task, data, datalen);
 899                 break;
 900         case ISCSI_OP_SCSI_DATA_IN:
 901                 iscsi_data_in_rsp(conn, hdr, task);
 902                 break;
 903         case ISCSI_OP_LOGOUT_RSP:
 904                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
 905                 if (datalen) {
 906                         rc = ISCSI_ERR_PROTO;
 907                         break;
 908                 }
 909                 conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 910                 goto recv_pdu;
 911         case ISCSI_OP_LOGIN_RSP:
 912         case ISCSI_OP_TEXT_RSP:
 913                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
 914                 /*
 915                  * login related PDU's exp_statsn is handled in
 916                  * userspace
 917                  */
 918                 goto recv_pdu;
 919         case ISCSI_OP_SCSI_TMFUNC_RSP:
 920                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
 921                 if (datalen) {
 922                         rc = ISCSI_ERR_PROTO;
 923                         break;
 924                 }
 925
 926                 iscsi_tmf_rsp(conn, hdr);
 927                 __iscsi_put_task(task);
 928                 break;
 929         case ISCSI_OP_NOOP_IN:
 930                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
 931                 if (hdr->ttt != cpu_to_be32(ISCSI_RESERVED_TAG) || datalen) {
 932                         rc = ISCSI_ERR_PROTO;
 933                         break;
 934                 }
 935                 conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 936
 937                 if (conn->ping_task != task)
 938                         /*
 939                          * If this is not in response to one of our
 940                          * nops then it must be from userspace.
 941                          */
 942                         goto recv_pdu;
 943
 944                 mod_timer(&conn->transport_timer, jiffies + conn->recv_timeout);
 945                 __iscsi_put_task(task);
 946                 break;
 947         default:
 948                 rc = ISCSI_ERR_BAD_OPCODE;
 949                 break;
 950         }
 951
 952 out:
 953         return rc;
 954 recv_pdu:
 955         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
 956                 rc = ISCSI_ERR_CONN_FAILED;
 957         __iscsi_put_task(task);
 958         return rc;
 959 }
 960 EXPORT_SYMBOL_GPL(__iscsi_complete_pdu);
 961
 962 int iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 963                        char *data, int datalen)
 964 {
 965         int rc;
 966
 967         spin_lock(&conn->session->lock);
 968         rc = __iscsi_complete_pdu(conn, hdr, data, datalen);
 969         spin_unlock(&conn->session->lock);
 970         return rc;
 971 }
 972 EXPORT_SYMBOL_GPL(iscsi_complete_pdu);
 973
 974 int iscsi_verify_itt(struct iscsi_conn *conn, itt_t itt)
 975 {
 976         struct iscsi_session *session = conn->session;
 977         int age = 0, i = 0;
 978
 979         if (itt == RESERVED_ITT)
 980                 return 0;
 981
 982         if (session->tt->parse_pdu_itt)
 983                 session->tt->parse_pdu_itt(conn, itt, &i, &age);
 984         else {
 985                 i = get_itt(itt);
 986                 age = ((__force u32)itt >> ISCSI_AGE_SHIFT) & ISCSI_AGE_MASK;
 987         }
 988
 989         if (age != session->age) {
 990                 iscsi_conn_printk(KERN_ERR, conn,
 991                                   "received itt %x expected session age (%x)\n",
 992                                   (__force u32)itt, session->age);
 993                 return ISCSI_ERR_BAD_ITT;
 994         }
 995
 996         if (i >= session->cmds_max) {
 997                 iscsi_conn_printk(KERN_ERR, conn,
 998                                   "received invalid itt index %u (max cmds "
 999                                    "%u.\n", i, session->cmds_max);
1000                 return ISCSI_ERR_BAD_ITT;
1001         }
1002         return 0;
1003 }
1004 EXPORT_SYMBOL_GPL(iscsi_verify_itt);
1005
1006 /**
1007  * iscsi_itt_to_ctask - look up ctask by itt
1008  * @conn: iscsi connection
1009  * @itt: itt
1010  *
1011  * This should be used for cmd tasks.
1012  *
1013  * The session lock must be held.
1014  */
1015 struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *conn, itt_t itt)
1016 {
1017         struct iscsi_task *task;
1018
1019         if (iscsi_verify_itt(conn, itt))
1020                 return NULL;
1021
1022         task = iscsi_itt_to_task(conn, itt);
1023         if (!task || !task->sc)
1024                 return NULL;
1025
1026         if (task->sc->SCp.phase != conn->session->age) {
1027                 iscsi_session_printk(KERN_ERR, conn->session,
1028                                   "task's session age %d, expected %d\n",
1029                                   task->sc->SCp.phase, conn->session->age);
1030                 return NULL;
1031         }
1032
1033         return task;
1034 }
1035 EXPORT_SYMBOL_GPL(iscsi_itt_to_ctask);
1036
1037 void iscsi_session_failure(struct iscsi_cls_session *cls_session,
1038                            enum iscsi_err err)
1039 {
1040         struct iscsi_session *session = cls_session->dd_data;
1041         struct iscsi_conn *conn;
1042         struct device *dev;
1043         unsigned long flags;
1044
1045         spin_lock_irqsave(&session->lock, flags);
1046         conn = session->leadconn;
1047         if (session->state == ISCSI_STATE_TERMINATE || !conn) {
1048                 spin_unlock_irqrestore(&session->lock, flags);
1049                 return;
1050         }
1051
1052         dev = get_device(&conn->cls_conn->dev);
1053         spin_unlock_irqrestore(&session->lock, flags);
1054         if (!dev)
1055                 return;
1056         /*
1057          * if the host is being removed bypass the connection
1058          * recovery initialization because we are going to kill
1059          * the session.
1060          */
1061         if (err == ISCSI_ERR_INVALID_HOST)
1062                 iscsi_conn_error_event(conn->cls_conn, err);
1063         else
1064                 iscsi_conn_failure(conn, err);
1065         put_device(dev);
1066 }
1067 EXPORT_SYMBOL_GPL(iscsi_session_failure);
1068
1069 void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err)
1070 {
1071         struct iscsi_session *session = conn->session;
1072         unsigned long flags;
1073
1074         spin_lock_irqsave(&session->lock, flags);
1075         if (session->state == ISCSI_STATE_FAILED) {
1076                 spin_unlock_irqrestore(&session->lock, flags);
1077                 return;
1078         }
1079
1080         if (conn->stop_stage == 0)
1081                 session->state = ISCSI_STATE_FAILED;
1082         spin_unlock_irqrestore(&session->lock, flags);
1083
1084         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1085         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
1086         iscsi_conn_error_event(conn->cls_conn, err);
1087 }
1088 EXPORT_SYMBOL_GPL(iscsi_conn_failure);
1089
1090 static int iscsi_check_cmdsn_window_closed(struct iscsi_conn *conn)
1091 {
1092         struct iscsi_session *session = conn->session;
1093
1094         /*
1095          * Check for iSCSI window and take care of CmdSN wrap-around
1096          */
1097         if (!iscsi_sna_lte(session->queued_cmdsn, session->max_cmdsn)) {
1098                 debug_scsi("iSCSI CmdSN closed. ExpCmdSn %u MaxCmdSN %u "
1099                            "CmdSN %u/%u\n", session->exp_cmdsn,
1100                            session->max_cmdsn, session->cmdsn,
1101                            session->queued_cmdsn);
1102                 return -ENOSPC;
1103         }
1104         return 0;
1105 }
1106
1107 static int iscsi_xmit_task(struct iscsi_conn *conn)
1108 {
1109         struct iscsi_task *task = conn->task;
1110         int rc;
1111
1112         __iscsi_get_task(task);
1113         spin_unlock_bh(&conn->session->lock);
1114         rc = conn->session->tt->xmit_task(task);
1115         spin_lock_bh(&conn->session->lock);
1116         __iscsi_put_task(task);
1117         if (!rc)
1118                 /* done with this task */
1119                 conn->task = NULL;
1120         return rc;
1121 }
1122
1123 /**
1124  * iscsi_requeue_task - requeue task to run from session workqueue
1125  * @task: task to requeue
1126  *
1127  * LLDs that need to run a task from the session workqueue should call
1128  * this. The session lock must be held. This should only be called
1129  * by software drivers.
1130  */
1131 void iscsi_requeue_task(struct iscsi_task *task)
1132 {
1133         struct iscsi_conn *conn = task->conn;
1134
1135         list_move_tail(&task->running, &conn->requeue);
1136         scsi_queue_work(conn->session->host, &conn->xmitwork);
1137 }
1138 EXPORT_SYMBOL_GPL(iscsi_requeue_task);
1139
1140 /**
1141  * iscsi_data_xmit - xmit any command into the scheduled connection
1142  * @conn: iscsi connection
1143  *
1144  * Notes:
1145  *      The function can return -EAGAIN in which case the caller must
1146  *      re-schedule it again later or recover. '0' return code means
1147  *      successful xmit.
1148  **/
1149 static int iscsi_data_xmit(struct iscsi_conn *conn)
1150 {
1151         int rc = 0;
1152
1153         spin_lock_bh(&conn->session->lock);
1154         if (unlikely(conn->suspend_tx)) {
1155                 debug_scsi("conn %d Tx suspended!\n", conn->id);
1156                 spin_unlock_bh(&conn->session->lock);
1157                 return -ENODATA;
1158         }
1159
1160         if (conn->task) {
1161                 rc = iscsi_xmit_task(conn);
1162                 if (rc)
1163                         goto again;
1164         }
1165
1166         /*
1167          * process mgmt pdus like nops before commands since we should
1168          * only have one nop-out as a ping from us and targets should not
1169          * overflow us with nop-ins
1170          */
1171 check_mgmt:
1172         while (!list_empty(&conn->mgmtqueue)) {
1173                 conn->task = list_entry(conn->mgmtqueue.next,
1174                                          struct iscsi_task, running);
1175                 if (iscsi_prep_mgmt_task(conn, conn->task)) {
1176                         __iscsi_put_task(conn->task);
1177                         conn->task = NULL;
1178                         continue;
1179                 }
1180                 rc = iscsi_xmit_task(conn);
1181                 if (rc)
1182                         goto again;
1183         }
1184
1185         /* process pending command queue */
1186         while (!list_empty(&conn->xmitqueue)) {
1187                 if (conn->tmf_state == TMF_QUEUED)
1188                         break;
1189
1190                 conn->task = list_entry(conn->xmitqueue.next,
1191                                          struct iscsi_task, running);
1192                 if (conn->session->state == ISCSI_STATE_LOGGING_OUT) {
1193                         fail_command(conn, conn->task, DID_IMM_RETRY << 16);
1194                         continue;
1195                 }
1196                 rc = iscsi_prep_scsi_cmd_pdu(conn->task);
1197                 if (rc) {
1198                         if (rc == -ENOMEM) {
1199                                 conn->task = NULL;
1200                                 goto again;
1201                         } else
1202                                 fail_command(conn, conn->task, DID_ABORT << 16);
1203                         continue;
1204                 }
1205                 rc = iscsi_xmit_task(conn);
1206                 if (rc)
1207                         goto again;
1208                 /*
1209                  * we could continuously get new task requests so
1210                  * we need to check the mgmt queue for nops that need to
1211                  * be sent to aviod starvation
1212                  */
1213                 if (!list_empty(&conn->mgmtqueue))
1214                         goto check_mgmt;
1215         }
1216
1217         while (!list_empty(&conn->requeue)) {
1218                 if (conn->session->fast_abort && conn->tmf_state != TMF_INITIAL)
1219                         break;
1220
1221                 /*
1222                  * we always do fastlogout - conn stop code will clean up.
1223                  */
1224                 if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
1225                         break;
1226
1227                 conn->task = list_entry(conn->requeue.next,
1228                                          struct iscsi_task, running);
1229                 conn->task->state = ISCSI_TASK_RUNNING;
1230                 list_move_tail(conn->requeue.next, &conn->run_list);
1231                 rc = iscsi_xmit_task(conn);
1232                 if (rc)
1233                         goto again;
1234                 if (!list_empty(&conn->mgmtqueue))
1235                         goto check_mgmt;
1236         }
1237         spin_unlock_bh(&conn->session->lock);
1238         return -ENODATA;
1239
1240 again:
1241         if (unlikely(conn->suspend_tx))
1242                 rc = -ENODATA;
1243         spin_unlock_bh(&conn->session->lock);
1244         return rc;
1245 }
1246
1247 static void iscsi_xmitworker(struct work_struct *work)
1248 {
1249         struct iscsi_conn *conn =
1250                 container_of(work, struct iscsi_conn, xmitwork);
1251         int rc;
1252         /*
1253          * serialize Xmit worker on a per-connection basis.
1254          */
1255         do {
1256                 rc = iscsi_data_xmit(conn);
1257         } while (rc >= 0 || rc == -EAGAIN);
1258 }
1259
1260 static inline struct iscsi_task *iscsi_alloc_task(struct iscsi_conn *conn,
1261                                                   struct scsi_cmnd *sc)
1262 {
1263         struct iscsi_task *task;
1264
1265         if (!__kfifo_get(conn->session->cmdpool.queue,
1266                          (void *) &task, sizeof(void *)))
1267                 return NULL;
1268
1269         sc->SCp.phase = conn->session->age;
1270         sc->SCp.ptr = (char *) task;
1271
1272         atomic_set(&task->refcount, 1);
1273         task->state = ISCSI_TASK_PENDING;
1274         task->conn = conn;
1275         task->sc = sc;
1276         INIT_LIST_HEAD(&task->running);
1277         return task;
1278 }
1279
1280 enum {
1281         FAILURE_BAD_HOST = 1,
1282         FAILURE_SESSION_FAILED,
1283         FAILURE_SESSION_FREED,
1284         FAILURE_WINDOW_CLOSED,
1285         FAILURE_OOM,
1286         FAILURE_SESSION_TERMINATE,
1287         FAILURE_SESSION_IN_RECOVERY,
1288         FAILURE_SESSION_RECOVERY_TIMEOUT,
1289         FAILURE_SESSION_LOGGING_OUT,
1290         FAILURE_SESSION_NOT_READY,
1291 };
1292
1293 int iscsi_queuecommand(struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *))
1294 {
1295         struct iscsi_cls_session *cls_session;
1296         struct Scsi_Host *host;
1297         int reason = 0;
1298         struct iscsi_session *session;
1299         struct iscsi_conn *conn;
1300         struct iscsi_task *task = NULL;
1301
1302         sc->scsi_done = done;
1303         sc->result = 0;
1304         sc->SCp.ptr = NULL;
1305
1306         host = sc->device->host;
1307         spin_unlock(host->host_lock);
1308
1309         cls_session = starget_to_session(scsi_target(sc->device));
1310         session = cls_session->dd_data;
1311         spin_lock(&session->lock);
1312
1313         reason = iscsi_session_chkready(cls_session);
1314         if (reason) {
1315                 sc->result = reason;
1316                 goto fault;
1317         }
1318
1319         /*
1320          * ISCSI_STATE_FAILED is a temp. state. The recovery
1321          * code will decide what is best to do with command queued
1322          * during this time
1323          */
1324         if (session->state != ISCSI_STATE_LOGGED_IN &&
1325             session->state != ISCSI_STATE_FAILED) {
1326                 /*
1327                  * to handle the race between when we set the recovery state
1328                  * and block the session we requeue here (commands could
1329                  * be entering our queuecommand while a block is starting
1330                  * up because the block code is not locked)
1331                  */
1332                 switch (session->state) {
1333                 case ISCSI_STATE_IN_RECOVERY:
1334                         reason = FAILURE_SESSION_IN_RECOVERY;
1335                         goto reject;
1336                 case ISCSI_STATE_LOGGING_OUT:
1337                         reason = FAILURE_SESSION_LOGGING_OUT;
1338                         goto reject;
1339                 case ISCSI_STATE_RECOVERY_FAILED:
1340                         reason = FAILURE_SESSION_RECOVERY_TIMEOUT;
1341                         sc->result = DID_TRANSPORT_FAILFAST << 16;
1342                         break;
1343                 case ISCSI_STATE_TERMINATE:
1344                         reason = FAILURE_SESSION_TERMINATE;
1345                         sc->result = DID_NO_CONNECT << 16;
1346                         break;
1347                 default:
1348                         reason = FAILURE_SESSION_FREED;
1349                         sc->result = DID_NO_CONNECT << 16;
1350                 }
1351                 goto fault;
1352         }
1353
1354         conn = session->leadconn;
1355         if (!conn) {
1356                 reason = FAILURE_SESSION_FREED;
1357                 sc->result = DID_NO_CONNECT << 16;
1358                 goto fault;
1359         }
1360
1361         if (iscsi_check_cmdsn_window_closed(conn)) {
1362                 reason = FAILURE_WINDOW_CLOSED;
1363                 goto reject;
1364         }
1365
1366         task = iscsi_alloc_task(conn, sc);
1367         if (!task) {
1368                 reason = FAILURE_OOM;
1369                 goto reject;
1370         }
1371         list_add_tail(&task->running, &conn->xmitqueue);
1372
1373         if (session->tt->caps & CAP_DATA_PATH_OFFLOAD) {
1374                 reason = iscsi_prep_scsi_cmd_pdu(task);
1375                 if (reason) {
1376                         if (reason == -ENOMEM) {
1377                                 reason = FAILURE_OOM;
1378                                 goto prepd_reject;
1379                         } else {
1380                                 sc->result = DID_ABORT << 16;
1381                                 goto prepd_fault;
1382                         }
1383                 }
1384                 if (session->tt->xmit_task(task)) {
1385                         reason = FAILURE_SESSION_NOT_READY;
1386                         goto prepd_reject;
1387                 }
1388         } else
1389                 scsi_queue_work(session->host, &conn->xmitwork);
1390
1391         session->queued_cmdsn++;
1392         spin_unlock(&session->lock);
1393         spin_lock(host->host_lock);
1394         return 0;
1395
1396 prepd_reject:
1397         sc->scsi_done = NULL;
1398         iscsi_complete_command(task);
1399 reject:
1400         spin_unlock(&session->lock);
1401         debug_scsi("cmd 0x%x rejected (%d)\n", sc->cmnd[0], reason);
1402         spin_lock(host->host_lock);
1403         return SCSI_MLQUEUE_TARGET_BUSY;
1404
1405 prepd_fault:
1406         sc->scsi_done = NULL;
1407         iscsi_complete_command(task);
1408 fault:
1409         spin_unlock(&session->lock);
1410         debug_scsi("iscsi: cmd 0x%x is not queued (%d)\n", sc->cmnd[0], reason);
1411         if (!scsi_bidi_cmnd(sc))
1412                 scsi_set_resid(sc, scsi_bufflen(sc));
1413         else {
1414                 scsi_out(sc)->resid = scsi_out(sc)->length;
1415                 scsi_in(sc)->resid = scsi_in(sc)->length;
1416         }
1417         done(sc);
1418         spin_lock(host->host_lock);
1419         return 0;
1420 }
1421 EXPORT_SYMBOL_GPL(iscsi_queuecommand);
1422
1423 int iscsi_change_queue_depth(struct scsi_device *sdev, int depth)
1424 {
1425         if (depth > ISCSI_MAX_CMD_PER_LUN)
1426                 depth = ISCSI_MAX_CMD_PER_LUN;
1427         scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
1428         return sdev->queue_depth;
1429 }
1430 EXPORT_SYMBOL_GPL(iscsi_change_queue_depth);
1431
1432 void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
1433 {
1434         struct iscsi_session *session = cls_session->dd_data;
1435
1436         spin_lock_bh(&session->lock);
1437         if (session->state != ISCSI_STATE_LOGGED_IN) {
1438                 session->state = ISCSI_STATE_RECOVERY_FAILED;
1439                 if (session->leadconn)
1440                         wake_up(&session->leadconn->ehwait);
1441         }
1442         spin_unlock_bh(&session->lock);
1443 }
1444 EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
1445
1446 int iscsi_eh_target_reset(struct scsi_cmnd *sc)
1447 {
1448         struct iscsi_cls_session *cls_session;
1449         struct iscsi_session *session;
1450         struct iscsi_conn *conn;
1451
1452         cls_session = starget_to_session(scsi_target(sc->device));
1453         session = cls_session->dd_data;
1454         conn = session->leadconn;
1455
1456         mutex_lock(&session->eh_mutex);
1457         spin_lock_bh(&session->lock);
1458         if (session->state == ISCSI_STATE_TERMINATE) {
1459 failed:
1460                 debug_scsi("failing target reset: session terminated "
1461                            "[CID %d age %d]\n", conn->id, session->age);
1462                 spin_unlock_bh(&session->lock);
1463                 mutex_unlock(&session->eh_mutex);
1464                 return FAILED;
1465         }
1466
1467         spin_unlock_bh(&session->lock);
1468         mutex_unlock(&session->eh_mutex);
1469         /*
1470          * we drop the lock here but the leadconn cannot be destoyed while
1471          * we are in the scsi eh
1472          */
1473         iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1474
1475         debug_scsi("iscsi_eh_target_reset wait for relogin\n");
1476         wait_event_interruptible(conn->ehwait,
1477                                  session->state == ISCSI_STATE_TERMINATE ||
1478                                  session->state == ISCSI_STATE_LOGGED_IN ||
1479                                  session->state == ISCSI_STATE_RECOVERY_FAILED);
1480         if (signal_pending(current))
1481                 flush_signals(current);
1482
1483         mutex_lock(&session->eh_mutex);
1484         spin_lock_bh(&session->lock);
1485         if (session->state == ISCSI_STATE_LOGGED_IN)
1486                 iscsi_session_printk(KERN_INFO, session,
1487                                      "target reset succeeded\n");
1488         else
1489                 goto failed;
1490         spin_unlock_bh(&session->lock);
1491         mutex_unlock(&session->eh_mutex);
1492         return SUCCESS;
1493 }
1494 EXPORT_SYMBOL_GPL(iscsi_eh_target_reset);
1495
1496 static void iscsi_tmf_timedout(unsigned long data)
1497 {
1498         struct iscsi_conn *conn = (struct iscsi_conn *)data;
1499         struct iscsi_session *session = conn->session;
1500
1501         spin_lock(&session->lock);
1502         if (conn->tmf_state == TMF_QUEUED) {
1503                 conn->tmf_state = TMF_TIMEDOUT;
1504                 debug_scsi("tmf timedout\n");
1505                 /* unblock eh_abort() */
1506                 wake_up(&conn->ehwait);
1507         }
1508         spin_unlock(&session->lock);
1509 }
1510
1511 static int iscsi_exec_task_mgmt_fn(struct iscsi_conn *conn,
1512                                    struct iscsi_tm *hdr, int age,
1513                                    int timeout)
1514 {
1515         struct iscsi_session *session = conn->session;
1516         struct iscsi_task *task;
1517
1518         task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)hdr,
1519                                       NULL, 0);
1520         if (!task) {
1521                 spin_unlock_bh(&session->lock);
1522                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1523                 spin_lock_bh(&session->lock);
1524                 debug_scsi("tmf exec failure\n");
1525                 return -EPERM;
1526         }
1527         conn->tmfcmd_pdus_cnt++;
1528         conn->tmf_timer.expires = timeout * HZ + jiffies;
1529         conn->tmf_timer.function = iscsi_tmf_timedout;
1530         conn->tmf_timer.data = (unsigned long)conn;
1531         add_timer(&conn->tmf_timer);
1532         debug_scsi("tmf set timeout\n");
1533
1534         spin_unlock_bh(&session->lock);
1535         mutex_unlock(&session->eh_mutex);
1536
1537         /*
1538          * block eh thread until:
1539          *
1540          * 1) tmf response
1541          * 2) tmf timeout
1542          * 3) session is terminated or restarted or userspace has
1543          * given up on recovery
1544          */
1545         wait_event_interruptible(conn->ehwait, age != session->age ||
1546                                  session->state != ISCSI_STATE_LOGGED_IN ||
1547                                  conn->tmf_state != TMF_QUEUED);
1548         if (signal_pending(current))
1549                 flush_signals(current);
1550         del_timer_sync(&conn->tmf_timer);
1551
1552         mutex_lock(&session->eh_mutex);
1553         spin_lock_bh(&session->lock);
1554         /* if the session drops it will clean up the task */
1555         if (age != session->age ||
1556             session->state != ISCSI_STATE_LOGGED_IN)
1557                 return -ENOTCONN;
1558         return 0;
1559 }
1560
1561 /*
1562  * Fail commands. session lock held and recv side suspended and xmit
1563  * thread flushed
1564  */
1565 static void fail_all_commands(struct iscsi_conn *conn, unsigned lun,
1566                               int error)
1567 {
1568         struct iscsi_task *task, *tmp;
1569
1570         if (conn->task && (conn->task->sc->device->lun == lun || lun == -1))
1571                 conn->task = NULL;
1572
1573         /* flush pending */
1574         list_for_each_entry_safe(task, tmp, &conn->xmitqueue, running) {
1575                 if (lun == task->sc->device->lun || lun == -1) {
1576                         debug_scsi("failing pending sc %p itt 0x%x\n",
1577                                    task->sc, task->itt);
1578                         fail_command(conn, task, error << 16);
1579                 }
1580         }
1581
1582         list_for_each_entry_safe(task, tmp, &conn->requeue, running) {
1583                 if (lun == task->sc->device->lun || lun == -1) {
1584                         debug_scsi("failing requeued sc %p itt 0x%x\n",
1585                                    task->sc, task->itt);
1586                         fail_command(conn, task, error << 16);
1587                 }
1588         }
1589
1590         /* fail all other running */
1591         list_for_each_entry_safe(task, tmp, &conn->run_list, running) {
1592                 if (lun == task->sc->device->lun || lun == -1) {
1593                         debug_scsi("failing in progress sc %p itt 0x%x\n",
1594                                    task->sc, task->itt);
1595                         fail_command(conn, task, error << 16);
1596                 }
1597         }
1598 }
1599
1600 void iscsi_suspend_tx(struct iscsi_conn *conn)
1601 {
1602         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1603         if (!(conn->session->tt->caps & CAP_DATA_PATH_OFFLOAD))
1604                 scsi_flush_work(conn->session->host);
1605 }
1606 EXPORT_SYMBOL_GPL(iscsi_suspend_tx);
1607
1608 static void iscsi_start_tx(struct iscsi_conn *conn)
1609 {
1610         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1611         if (!(conn->session->tt->caps & CAP_DATA_PATH_OFFLOAD))
1612                 scsi_queue_work(conn->session->host, &conn->xmitwork);
1613 }
1614
1615 static enum blk_eh_timer_return iscsi_eh_cmd_timed_out(struct scsi_cmnd *scmd)
1616 {
1617         struct iscsi_cls_session *cls_session;
1618         struct iscsi_session *session;
1619         struct iscsi_conn *conn;
1620         enum blk_eh_timer_return rc = BLK_EH_NOT_HANDLED;
1621
1622         cls_session = starget_to_session(scsi_target(scmd->device));
1623         session = cls_session->dd_data;
1624
1625         debug_scsi("scsi cmd %p timedout\n", scmd);
1626
1627         spin_lock(&session->lock);
1628         if (session->state != ISCSI_STATE_LOGGED_IN) {
1629                 /*
1630                  * We are probably in the middle of iscsi recovery so let
1631                  * that complete and handle the error.
1632                  */
1633                 rc = BLK_EH_RESET_TIMER;
1634                 goto done;
1635         }
1636
1637         conn = session->leadconn;
1638         if (!conn) {
1639                 /* In the middle of shuting down */
1640                 rc = BLK_EH_RESET_TIMER;
1641                 goto done;
1642         }
1643
1644         if (!conn->recv_timeout && !conn->ping_timeout)
1645                 goto done;
1646         /*
1647          * if the ping timedout then we are in the middle of cleaning up
1648          * and can let the iscsi eh handle it
1649          */
1650         if (time_before_eq(conn->last_recv + (conn->recv_timeout * HZ) +
1651                             (conn->ping_timeout * HZ), jiffies))
1652                 rc = BLK_EH_RESET_TIMER;
1653         /*
1654          * if we are about to check the transport then give the command
1655          * more time
1656          */
1657         if (time_before_eq(conn->last_recv + (conn->recv_timeout * HZ),
1658                            jiffies))
1659                 rc = BLK_EH_RESET_TIMER;
1660         /* if in the middle of checking the transport then give us more time */
1661         if (conn->ping_task)
1662                 rc = BLK_EH_RESET_TIMER;
1663 done:
1664         spin_unlock(&session->lock);
1665         debug_scsi("return %s\n", rc == BLK_EH_RESET_TIMER ?
1666                                         "timer reset" : "nh");
1667         return rc;
1668 }
1669
1670 static void iscsi_check_transport_timeouts(unsigned long data)
1671 {
1672         struct iscsi_conn *conn = (struct iscsi_conn *)data;
1673         struct iscsi_session *session = conn->session;
1674         unsigned long recv_timeout, next_timeout = 0, last_recv;
1675
1676         spin_lock(&session->lock);
1677         if (session->state != ISCSI_STATE_LOGGED_IN)
1678                 goto done;
1679
1680         recv_timeout = conn->recv_timeout;
1681         if (!recv_timeout)
1682                 goto done;
1683
1684         recv_timeout *= HZ;
1685         last_recv = conn->last_recv;
1686         if (conn->ping_task &&
1687             time_before_eq(conn->last_ping + (conn->ping_timeout * HZ),
1688                            jiffies)) {
1689                 iscsi_conn_printk(KERN_ERR, conn, "ping timeout of %d secs "
1690                                   "expired, last rx %lu, last ping %lu, "
1691                                   "now %lu\n", conn->ping_timeout, last_recv,
1692                                   conn->last_ping, jiffies);
1693                 spin_unlock(&session->lock);
1694                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1695                 return;
1696         }
1697
1698         if (time_before_eq(last_recv + recv_timeout, jiffies)) {
1699                 /* send a ping to try to provoke some traffic */
1700                 debug_scsi("Sending nopout as ping on conn %p\n", conn);
1701                 iscsi_send_nopout(conn, NULL);
1702                 next_timeout = conn->last_ping + (conn->ping_timeout * HZ);
1703         } else
1704                 next_timeout = last_recv + recv_timeout;
1705
1706         debug_scsi("Setting next tmo %lu\n", next_timeout);
1707         mod_timer(&conn->transport_timer, next_timeout);
1708 done:
1709         spin_unlock(&session->lock);
1710 }
1711
1712 static void iscsi_prep_abort_task_pdu(struct iscsi_task *task,
1713                                       struct iscsi_tm *hdr)
1714 {
1715         memset(hdr, 0, sizeof(*hdr));
1716         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
1717         hdr->flags = ISCSI_TM_FUNC_ABORT_TASK & ISCSI_FLAG_TM_FUNC_MASK;
1718         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
1719         memcpy(hdr->lun, task->lun, sizeof(hdr->lun));
1720         hdr->rtt = task->hdr_itt;
1721         hdr->refcmdsn = task->cmdsn;
1722 }
1723
1724 int iscsi_eh_abort(struct scsi_cmnd *sc)
1725 {
1726         struct iscsi_cls_session *cls_session;
1727         struct iscsi_session *session;
1728         struct iscsi_conn *conn;
1729         struct iscsi_task *task;
1730         struct iscsi_tm *hdr;
1731         int rc, age;
1732
1733         cls_session = starget_to_session(scsi_target(sc->device));
1734         session = cls_session->dd_data;
1735
1736         mutex_lock(&session->eh_mutex);
1737         spin_lock_bh(&session->lock);
1738         /*
1739          * if session was ISCSI_STATE_IN_RECOVERY then we may not have
1740          * got the command.
1741          */
1742         if (!sc->SCp.ptr) {
1743                 debug_scsi("sc never reached iscsi layer or it completed.\n");
1744                 spin_unlock_bh(&session->lock);
1745                 mutex_unlock(&session->eh_mutex);
1746                 return SUCCESS;
1747         }
1748
1749         /*
1750          * If we are not logged in or we have started a new session
1751          * then let the host reset code handle this
1752          */
1753         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN ||
1754             sc->SCp.phase != session->age) {
1755                 spin_unlock_bh(&session->lock);
1756                 mutex_unlock(&session->eh_mutex);
1757                 return FAILED;
1758         }
1759
1760         conn = session->leadconn;
1761         conn->eh_abort_cnt++;
1762         age = session->age;
1763
1764         task = (struct iscsi_task *)sc->SCp.ptr;
1765         debug_scsi("aborting [sc %p itt 0x%x]\n", sc, task->itt);
1766
1767         /* task completed before time out */
1768         if (!task->sc) {
1769                 debug_scsi("sc completed while abort in progress\n");
1770                 goto success;
1771         }
1772
1773         if (task->state == ISCSI_TASK_PENDING) {
1774                 fail_command(conn, task, DID_ABORT << 16);
1775                 goto success;
1776         }
1777
1778         /* only have one tmf outstanding at a time */
1779         if (conn->tmf_state != TMF_INITIAL)
1780                 goto failed;
1781         conn->tmf_state = TMF_QUEUED;
1782
1783         hdr = &conn->tmhdr;
1784         iscsi_prep_abort_task_pdu(task, hdr);
1785
1786         if (iscsi_exec_task_mgmt_fn(conn, hdr, age, session->abort_timeout)) {
1787                 rc = FAILED;
1788                 goto failed;
1789         }
1790
1791         switch (conn->tmf_state) {
1792         case TMF_SUCCESS:
1793                 spin_unlock_bh(&session->lock);
1794                 /*
1795                  * stop tx side incase the target had sent a abort rsp but
1796                  * the initiator was still writing out data.
1797                  */
1798                 iscsi_suspend_tx(conn);
1799                 /*
1800                  * we do not stop the recv side because targets have been
1801                  * good and have never sent us a successful tmf response
1802                  * then sent more data for the cmd.
1803                  */
1804                 spin_lock(&session->lock);
1805                 fail_command(conn, task, DID_ABORT << 16);
1806                 conn->tmf_state = TMF_INITIAL;
1807                 spin_unlock(&session->lock);
1808                 iscsi_start_tx(conn);
1809                 goto success_unlocked;
1810         case TMF_TIMEDOUT:
1811                 spin_unlock_bh(&session->lock);
1812                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1813                 goto failed_unlocked;
1814         case TMF_NOT_FOUND:
1815                 if (!sc->SCp.ptr) {
1816                         conn->tmf_state = TMF_INITIAL;
1817                         /* task completed before tmf abort response */
1818                         debug_scsi("sc completed while abort in progress\n");
1819                         goto success;
1820                 }
1821                 /* fall through */
1822         default:
1823                 conn->tmf_state = TMF_INITIAL;
1824                 goto failed;
1825         }
1826
1827 success:
1828         spin_unlock_bh(&session->lock);
1829 success_unlocked:
1830         debug_scsi("abort success [sc %lx itt 0x%x]\n", (long)sc, task->itt);
1831         mutex_unlock(&session->eh_mutex);
1832         return SUCCESS;
1833
1834 failed:
1835         spin_unlock_bh(&session->lock);
1836 failed_unlocked:
1837         debug_scsi("abort failed [sc %p itt 0x%x]\n", sc,
1838                     task ? task->itt : 0);
1839         mutex_unlock(&session->eh_mutex);
1840         return FAILED;
1841 }
1842 EXPORT_SYMBOL_GPL(iscsi_eh_abort);
1843
1844 static void iscsi_prep_lun_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
1845 {
1846         memset(hdr, 0, sizeof(*hdr));
1847         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
1848         hdr->flags = ISCSI_TM_FUNC_LOGICAL_UNIT_RESET & ISCSI_FLAG_TM_FUNC_MASK;
1849         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
1850         int_to_scsilun(sc->device->lun, (struct scsi_lun *)hdr->lun);
1851         hdr->rtt = RESERVED_ITT;
1852 }
1853
1854 int iscsi_eh_device_reset(struct scsi_cmnd *sc)
1855 {
1856         struct iscsi_cls_session *cls_session;
1857         struct iscsi_session *session;
1858         struct iscsi_conn *conn;
1859         struct iscsi_tm *hdr;
1860         int rc = FAILED;
1861
1862         cls_session = starget_to_session(scsi_target(sc->device));
1863         session = cls_session->dd_data;
1864
1865         debug_scsi("LU Reset [sc %p lun %u]\n", sc, sc->device->lun);
1866
1867         mutex_lock(&session->eh_mutex);
1868         spin_lock_bh(&session->lock);
1869         /*
1870          * Just check if we are not logged in. We cannot check for
1871          * the phase because the reset could come from a ioctl.
1872          */
1873         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
1874                 goto unlock;
1875         conn = session->leadconn;
1876
1877         /* only have one tmf outstanding at a time */
1878         if (conn->tmf_state != TMF_INITIAL)
1879                 goto unlock;
1880         conn->tmf_state = TMF_QUEUED;
1881
1882         hdr = &conn->tmhdr;
1883         iscsi_prep_lun_reset_pdu(sc, hdr);
1884
1885         if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
1886                                     session->lu_reset_timeout)) {
1887                 rc = FAILED;
1888                 goto unlock;
1889         }
1890
1891         switch (conn->tmf_state) {
1892         case TMF_SUCCESS:
1893                 break;
1894         case TMF_TIMEDOUT:
1895                 spin_unlock_bh(&session->lock);
1896                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1897                 goto done;
1898         default:
1899                 conn->tmf_state = TMF_INITIAL;
1900                 goto unlock;
1901         }
1902
1903         rc = SUCCESS;
1904         spin_unlock_bh(&session->lock);
1905
1906         iscsi_suspend_tx(conn);
1907
1908         spin_lock_bh(&session->lock);
1909         fail_all_commands(conn, sc->device->lun, DID_ERROR);
1910         conn->tmf_state = TMF_INITIAL;
1911         spin_unlock_bh(&session->lock);
1912
1913         iscsi_start_tx(conn);
1914         goto done;
1915
1916 unlock:
1917         spin_unlock_bh(&session->lock);
1918 done:
1919         debug_scsi("iscsi_eh_device_reset %s\n",
1920                   rc == SUCCESS ? "SUCCESS" : "FAILED");
1921         mutex_unlock(&session->eh_mutex);
1922         return rc;
1923 }
1924 EXPORT_SYMBOL_GPL(iscsi_eh_device_reset);
1925
1926 /*
1927  * Pre-allocate a pool of @max items of @item_size. By default, the pool
1928  * should be accessed via kfifo_{get,put} on q->queue.
1929  * Optionally, the caller can obtain the array of object pointers
1930  * by passing in a non-NULL @items pointer
1931  */
1932 int
1933 iscsi_pool_init(struct iscsi_pool *q, int max, void ***items, int item_size)
1934 {
1935         int i, num_arrays = 1;
1936
1937         memset(q, 0, sizeof(*q));
1938
1939         q->max = max;
1940
1941         /* If the user passed an items pointer, he wants a copy of
1942          * the array. */
1943         if (items)
1944                 num_arrays++;
1945         q->pool = kzalloc(num_arrays * max * sizeof(void*), GFP_KERNEL);
1946         if (q->pool == NULL)
1947                 goto enomem;
1948
1949         q->queue = kfifo_init((void*)q->pool, max * sizeof(void*),
1950                               GFP_KERNEL, NULL);
1951         if (q->queue == ERR_PTR(-ENOMEM))
1952                 goto enomem;
1953
1954         for (i = 0; i < max; i++) {
1955                 q->pool[i] = kzalloc(item_size, GFP_KERNEL);
1956                 if (q->pool[i] == NULL) {
1957                         q->max = i;
1958                         goto enomem;
1959                 }
1960                 __kfifo_put(q->queue, (void*)&q->pool[i], sizeof(void*));
1961         }
1962
1963         if (items) {
1964                 *items = q->pool + max;
1965                 memcpy(*items, q->pool, max * sizeof(void *));
1966         }
1967
1968         return 0;
1969
1970 enomem:
1971         iscsi_pool_free(q);
1972         return -ENOMEM;
1973 }
1974 EXPORT_SYMBOL_GPL(iscsi_pool_init);
1975
1976 void iscsi_pool_free(struct iscsi_pool *q)
1977 {
1978         int i;
1979
1980         for (i = 0; i < q->max; i++)
1981                 kfree(q->pool[i]);
1982         if (q->pool)
1983                 kfree(q->pool);
1984         kfree(q->queue);
1985 }
1986 EXPORT_SYMBOL_GPL(iscsi_pool_free);
1987
1988 /**
1989  * iscsi_host_add - add host to system
1990  * @shost: scsi host
1991  * @pdev: parent device
1992  *
1993  * This should be called by partial offload and software iscsi drivers
1994  * to add a host to the system.
1995  */
1996 int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev)
1997 {
1998         if (!shost->can_queue)
1999                 shost->can_queue = ISCSI_DEF_XMIT_CMDS_MAX;
2000
2001         if (!shost->transportt->eh_timed_out)
2002                 shost->transportt->eh_timed_out = iscsi_eh_cmd_timed_out;
2003         return scsi_add_host(shost, pdev);
2004 }
2005 EXPORT_SYMBOL_GPL(iscsi_host_add);
2006
2007 /**
2008  * iscsi_host_alloc - allocate a host and driver data
2009  * @sht: scsi host template
2010  * @dd_data_size: driver host data size
2011  * @qdepth: default device queue depth
2012  *
2013  * This should be called by partial offload and software iscsi drivers.
2014  * To access the driver specific memory use the iscsi_host_priv() macro.
2015  */
2016 struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
2017                                    int dd_data_size, uint16_t qdepth)
2018 {
2019         struct Scsi_Host *shost;
2020         struct iscsi_host *ihost;
2021
2022         shost = scsi_host_alloc(sht, sizeof(struct iscsi_host) + dd_data_size);
2023         if (!shost)
2024                 return NULL;
2025
2026         if (qdepth > ISCSI_MAX_CMD_PER_LUN || qdepth < 1) {
2027                 if (qdepth != 0)
2028                         printk(KERN_ERR "iscsi: invalid queue depth of %d. "
2029                                "Queue depth must be between 1 and %d.\n",
2030                                qdepth, ISCSI_MAX_CMD_PER_LUN);
2031                 qdepth = ISCSI_DEF_CMD_PER_LUN;
2032         }
2033         shost->cmd_per_lun = qdepth;
2034
2035         ihost = shost_priv(shost);
2036         spin_lock_init(&ihost->lock);
2037         ihost->state = ISCSI_HOST_SETUP;
2038         ihost->num_sessions = 0;
2039         init_waitqueue_head(&ihost->session_removal_wq);
2040         return shost;
2041 }
2042 EXPORT_SYMBOL_GPL(iscsi_host_alloc);
2043
2044 static void iscsi_notify_host_removed(struct iscsi_cls_session *cls_session)
2045 {
2046         iscsi_session_failure(cls_session, ISCSI_ERR_INVALID_HOST);
2047 }
2048
2049 /**
2050  * iscsi_host_remove - remove host and sessions
2051  * @shost: scsi host
2052  *
2053  * If there are any sessions left, this will initiate the removal and wait
2054  * for the completion.
2055  */
2056 void iscsi_host_remove(struct Scsi_Host *shost)
2057 {
2058         struct iscsi_host *ihost = shost_priv(shost);
2059         unsigned long flags;
2060
2061         spin_lock_irqsave(&ihost->lock, flags);
2062         ihost->state = ISCSI_HOST_REMOVED;
2063         spin_unlock_irqrestore(&ihost->lock, flags);
2064
2065         iscsi_host_for_each_session(shost, iscsi_notify_host_removed);
2066         wait_event_interruptible(ihost->session_removal_wq,
2067                                  ihost->num_sessions == 0);
2068         if (signal_pending(current))
2069                 flush_signals(current);
2070
2071         scsi_remove_host(shost);
2072 }
2073 EXPORT_SYMBOL_GPL(iscsi_host_remove);
2074
2075 void iscsi_host_free(struct Scsi_Host *shost)
2076 {
2077         struct iscsi_host *ihost = shost_priv(shost);
2078
2079         kfree(ihost->netdev);
2080         kfree(ihost->hwaddress);
2081         kfree(ihost->initiatorname);
2082         scsi_host_put(shost);
2083 }
2084 EXPORT_SYMBOL_GPL(iscsi_host_free);
2085
2086 static void iscsi_host_dec_session_cnt(struct Scsi_Host *shost)
2087 {
2088         struct iscsi_host *ihost = shost_priv(shost);
2089         unsigned long flags;
2090
2091         shost = scsi_host_get(shost);
2092         if (!shost) {
2093                 printk(KERN_ERR "Invalid state. Cannot notify host removal "
2094                       "of session teardown event because host already "
2095                       "removed.\n");
2096                 return;
2097         }
2098
2099         spin_lock_irqsave(&ihost->lock, flags);
2100         ihost->num_sessions--;
2101         if (ihost->num_sessions == 0)
2102                 wake_up(&ihost->session_removal_wq);
2103         spin_unlock_irqrestore(&ihost->lock, flags);
2104         scsi_host_put(shost);
2105 }
2106
2107 /**
2108  * iscsi_session_setup - create iscsi cls session and host and session
2109  * @iscsit: iscsi transport template
2110  * @shost: scsi host
2111  * @cmds_max: session can queue
2112  * @cmd_task_size: LLD task private data size
2113  * @initial_cmdsn: initial CmdSN
2114  *
2115  * This can be used by software iscsi_transports that allocate
2116  * a session per scsi host.
2117  *
2118  * Callers should set cmds_max to the largest total numer (mgmt + scsi) of
2119  * tasks they support. The iscsi layer reserves ISCSI_MGMT_CMDS_MAX tasks
2120  * for nop handling and login/logout requests.
2121  */
2122 struct iscsi_cls_session *
2123 iscsi_session_setup(struct iscsi_transport *iscsit, struct Scsi_Host *shost,
2124                     uint16_t cmds_max, int cmd_task_size,
2125                     uint32_t initial_cmdsn, unsigned int id)
2126 {
2127         struct iscsi_host *ihost = shost_priv(shost);
2128         struct iscsi_session *session;
2129         struct iscsi_cls_session *cls_session;
2130         int cmd_i, scsi_cmds, total_cmds = cmds_max;
2131         unsigned long flags;
2132
2133         spin_lock_irqsave(&ihost->lock, flags);
2134         if (ihost->state == ISCSI_HOST_REMOVED) {
2135                 spin_unlock_irqrestore(&ihost->lock, flags);
2136                 return NULL;
2137         }
2138         ihost->num_sessions++;
2139         spin_unlock_irqrestore(&ihost->lock, flags);
2140
2141         if (!total_cmds)
2142                 total_cmds = ISCSI_DEF_XMIT_CMDS_MAX;
2143         /*
2144          * The iscsi layer needs some tasks for nop handling and tmfs,
2145          * so the cmds_max must at least be greater than ISCSI_MGMT_CMDS_MAX
2146          * + 1 command for scsi IO.
2147          */
2148         if (total_cmds < ISCSI_TOTAL_CMDS_MIN) {
2149                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2150                        "must be a power of two that is at least %d.\n",
2151                        total_cmds, ISCSI_TOTAL_CMDS_MIN);
2152                 goto dec_session_count;
2153         }
2154
2155         if (total_cmds > ISCSI_TOTAL_CMDS_MAX) {
2156                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2157                        "must be a power of 2 less than or equal to %d.\n",
2158                        cmds_max, ISCSI_TOTAL_CMDS_MAX);
2159                 total_cmds = ISCSI_TOTAL_CMDS_MAX;
2160         }
2161
2162         if (!is_power_of_2(total_cmds)) {
2163                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2164                        "must be a power of 2.\n", total_cmds);
2165                 total_cmds = rounddown_pow_of_two(total_cmds);
2166                 if (total_cmds < ISCSI_TOTAL_CMDS_MIN)
2167                         return NULL;
2168                 printk(KERN_INFO "iscsi: Rounding can_queue to %d.\n",
2169                        total_cmds);
2170         }
2171         scsi_cmds = total_cmds - ISCSI_MGMT_CMDS_MAX;
2172
2173         cls_session = iscsi_alloc_session(shost, iscsit,
2174                                           sizeof(struct iscsi_session));
2175         if (!cls_session)
2176                 goto dec_session_count;
2177         session = cls_session->dd_data;
2178         session->cls_session = cls_session;
2179         session->host = shost;
2180         session->state = ISCSI_STATE_FREE;
2181         session->fast_abort = 1;
2182         session->lu_reset_timeout = 15;
2183         session->abort_timeout = 10;
2184         session->scsi_cmds_max = scsi_cmds;
2185         session->cmds_max = total_cmds;
2186         session->queued_cmdsn = session->cmdsn = initial_cmdsn;
2187         session->exp_cmdsn = initial_cmdsn + 1;
2188         session->max_cmdsn = initial_cmdsn + 1;
2189         session->max_r2t = 1;
2190         session->tt = iscsit;
2191         mutex_init(&session->eh_mutex);
2192         spin_lock_init(&session->lock);
2193
2194         /* initialize SCSI PDU commands pool */
2195         if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
2196                             (void***)&session->cmds,
2197                             cmd_task_size + sizeof(struct iscsi_task)))
2198                 goto cmdpool_alloc_fail;
2199
2200         /* pre-format cmds pool with ITT */
2201         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
2202                 struct iscsi_task *task = session->cmds[cmd_i];
2203
2204                 if (cmd_task_size)
2205                         task->dd_data = &task[1];
2206                 task->itt = cmd_i;
2207                 INIT_LIST_HEAD(&task->running);
2208         }
2209
2210         if (!try_module_get(iscsit->owner))
2211                 goto module_get_fail;
2212
2213         if (iscsi_add_session(cls_session, id))
2214                 goto cls_session_fail;
2215
2216         return cls_session;
2217
2218 cls_session_fail:
2219         module_put(iscsit->owner);
2220 module_get_fail:
2221         iscsi_pool_free(&session->cmdpool);
2222 cmdpool_alloc_fail:
2223         iscsi_free_session(cls_session);
2224 dec_session_count:
2225         iscsi_host_dec_session_cnt(shost);
2226         return NULL;
2227 }
2228 EXPORT_SYMBOL_GPL(iscsi_session_setup);
2229
2230 /**
2231  * iscsi_session_teardown - destroy session, host, and cls_session
2232  * @cls_session: iscsi session
2233  *
2234  * The driver must have called iscsi_remove_session before
2235  * calling this.
2236  */
2237 void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
2238 {
2239         struct iscsi_session *session = cls_session->dd_data;
2240         struct module *owner = cls_session->transport->owner;
2241         struct Scsi_Host *shost = session->host;
2242
2243         iscsi_pool_free(&session->cmdpool);
2244
2245         kfree(session->password);
2246         kfree(session->password_in);
2247         kfree(session->username);
2248         kfree(session->username_in);
2249         kfree(session->targetname);
2250         kfree(session->initiatorname);
2251         kfree(session->ifacename);
2252
2253         iscsi_destroy_session(cls_session);
2254         iscsi_host_dec_session_cnt(shost);
2255         module_put(owner);
2256 }
2257 EXPORT_SYMBOL_GPL(iscsi_session_teardown);
2258
2259 /**
2260  * iscsi_conn_setup - create iscsi_cls_conn and iscsi_conn
2261  * @cls_session: iscsi_cls_session
2262  * @dd_size: private driver data size
2263  * @conn_idx: cid
2264  */
2265 struct iscsi_cls_conn *
2266 iscsi_conn_setup(struct iscsi_cls_session *cls_session, int dd_size,
2267                  uint32_t conn_idx)
2268 {
2269         struct iscsi_session *session = cls_session->dd_data;
2270         struct iscsi_conn *conn;
2271         struct iscsi_cls_conn *cls_conn;
2272         char *data;
2273
2274         cls_conn = iscsi_create_conn(cls_session, sizeof(*conn) + dd_size,
2275                                      conn_idx);
2276         if (!cls_conn)
2277                 return NULL;
2278         conn = cls_conn->dd_data;
2279         memset(conn, 0, sizeof(*conn) + dd_size);
2280
2281         conn->dd_data = cls_conn->dd_data + sizeof(*conn);
2282         conn->session = session;
2283         conn->cls_conn = cls_conn;
2284         conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
2285         conn->id = conn_idx;
2286         conn->exp_statsn = 0;
2287         conn->tmf_state = TMF_INITIAL;
2288
2289         init_timer(&conn->transport_timer);
2290         conn->transport_timer.data = (unsigned long)conn;
2291         conn->transport_timer.function = iscsi_check_transport_timeouts;
2292
2293         INIT_LIST_HEAD(&conn->run_list);
2294         INIT_LIST_HEAD(&conn->mgmt_run_list);
2295         INIT_LIST_HEAD(&conn->mgmtqueue);
2296         INIT_LIST_HEAD(&conn->xmitqueue);
2297         INIT_LIST_HEAD(&conn->requeue);
2298         INIT_WORK(&conn->xmitwork, iscsi_xmitworker);
2299
2300         /* allocate login_task used for the login/text sequences */
2301         spin_lock_bh(&session->lock);
2302         if (!__kfifo_get(session->cmdpool.queue,
2303                          (void*)&conn->login_task,
2304                          sizeof(void*))) {
2305                 spin_unlock_bh(&session->lock);
2306                 goto login_task_alloc_fail;
2307         }
2308         spin_unlock_bh(&session->lock);
2309
2310         data = (char *) __get_free_pages(GFP_KERNEL,
2311                                          get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
2312         if (!data)
2313                 goto login_task_data_alloc_fail;
2314         conn->login_task->data = conn->data = data;
2315
2316         init_timer(&conn->tmf_timer);
2317         init_waitqueue_head(&conn->ehwait);
2318
2319         return cls_conn;
2320
2321 login_task_data_alloc_fail:
2322         __kfifo_put(session->cmdpool.queue, (void*)&conn->login_task,
2323                     sizeof(void*));
2324 login_task_alloc_fail:
2325         iscsi_destroy_conn(cls_conn);
2326         return NULL;
2327 }
2328 EXPORT_SYMBOL_GPL(iscsi_conn_setup);
2329
2330 /**
2331  * iscsi_conn_teardown - teardown iscsi connection
2332  * cls_conn: iscsi class connection
2333  *
2334  * TODO: we may need to make this into a two step process
2335  * like scsi-mls remove + put host
2336  */
2337 void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
2338 {
2339         struct iscsi_conn *conn = cls_conn->dd_data;
2340         struct iscsi_session *session = conn->session;
2341         unsigned long flags;
2342
2343         del_timer_sync(&conn->transport_timer);
2344
2345         spin_lock_bh(&session->lock);
2346         conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
2347         if (session->leadconn == conn) {
2348                 /*
2349                  * leading connection? then give up on recovery.
2350                  */
2351                 session->state = ISCSI_STATE_TERMINATE;
2352                 wake_up(&conn->ehwait);
2353         }
2354         spin_unlock_bh(&session->lock);
2355
2356         /*
2357          * Block until all in-progress commands for this connection
2358          * time out or fail.
2359          */
2360         for (;;) {
2361                 spin_lock_irqsave(session->host->host_lock, flags);
2362                 if (!session->host->host_busy) { /* OK for ERL == 0 */
2363                         spin_unlock_irqrestore(session->host->host_lock, flags);
2364                         break;
2365                 }
2366                 spin_unlock_irqrestore(session->host->host_lock, flags);
2367                 msleep_interruptible(500);
2368                 iscsi_conn_printk(KERN_INFO, conn, "iscsi conn_destroy(): "
2369                                   "host_busy %d host_failed %d\n",
2370                                   session->host->host_busy,
2371                                   session->host->host_failed);
2372                 /*
2373                  * force eh_abort() to unblock
2374                  */
2375                 wake_up(&conn->ehwait);
2376         }
2377
2378         /* flush queued up work because we free the connection below */
2379         iscsi_suspend_tx(conn);
2380
2381         spin_lock_bh(&session->lock);
2382         free_pages((unsigned long) conn->data,
2383                    get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
2384         kfree(conn->persistent_address);
2385         __kfifo_put(session->cmdpool.queue, (void*)&conn->login_task,
2386                     sizeof(void*));
2387         if (session->leadconn == conn)
2388                 session->leadconn = NULL;
2389         spin_unlock_bh(&session->lock);
2390
2391         iscsi_destroy_conn(cls_conn);
2392 }
2393 EXPORT_SYMBOL_GPL(iscsi_conn_teardown);
2394
2395 int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
2396 {
2397         struct iscsi_conn *conn = cls_conn->dd_data;
2398         struct iscsi_session *session = conn->session;
2399
2400         if (!session) {
2401                 iscsi_conn_printk(KERN_ERR, conn,
2402                                   "can't start unbound connection\n");
2403                 return -EPERM;
2404         }
2405
2406         if ((session->imm_data_en || !session->initial_r2t_en) &&
2407              session->first_burst > session->max_burst) {
2408                 iscsi_conn_printk(KERN_INFO, conn, "invalid burst lengths: "
2409                                   "first_burst %d max_burst %d\n",
2410                                   session->first_burst, session->max_burst);
2411                 return -EINVAL;
2412         }
2413
2414         if (conn->ping_timeout && !conn->recv_timeout) {
2415                 iscsi_conn_printk(KERN_ERR, conn, "invalid recv timeout of "
2416                                   "zero. Using 5 seconds\n.");
2417                 conn->recv_timeout = 5;
2418         }
2419
2420         if (conn->recv_timeout && !conn->ping_timeout) {
2421                 iscsi_conn_printk(KERN_ERR, conn, "invalid ping timeout of "
2422                                   "zero. Using 5 seconds.\n");
2423                 conn->ping_timeout = 5;
2424         }
2425
2426         spin_lock_bh(&session->lock);
2427         conn->c_stage = ISCSI_CONN_STARTED;
2428         session->state = ISCSI_STATE_LOGGED_IN;
2429         session->queued_cmdsn = session->cmdsn;
2430
2431         conn->last_recv = jiffies;
2432         conn->last_ping = jiffies;
2433         if (conn->recv_timeout && conn->ping_timeout)
2434                 mod_timer(&conn->transport_timer,
2435                           jiffies + (conn->recv_timeout * HZ));
2436
2437         switch(conn->stop_stage) {
2438         case STOP_CONN_RECOVER:
2439                 /*
2440                  * unblock eh_abort() if it is blocked. re-try all
2441                  * commands after successful recovery
2442                  */
2443                 conn->stop_stage = 0;
2444                 conn->tmf_state = TMF_INITIAL;
2445                 session->age++;
2446                 if (session->age == 16)
2447                         session->age = 0;
2448                 break;
2449         case STOP_CONN_TERM:
2450                 conn->stop_stage = 0;
2451                 break;
2452         default:
2453                 break;
2454         }
2455         spin_unlock_bh(&session->lock);
2456
2457         iscsi_unblock_session(session->cls_session);
2458         wake_up(&conn->ehwait);
2459         return 0;
2460 }
2461 EXPORT_SYMBOL_GPL(iscsi_conn_start);
2462
2463 static void
2464 flush_control_queues(struct iscsi_session *session, struct iscsi_conn *conn)
2465 {
2466         struct iscsi_task *task, *tmp;
2467
2468         /* handle pending */
2469         list_for_each_entry_safe(task, tmp, &conn->mgmtqueue, running) {
2470                 debug_scsi("flushing pending mgmt task itt 0x%x\n", task->itt);
2471                 /* release ref from prep task */
2472                 __iscsi_put_task(task);
2473         }
2474
2475         /* handle running */
2476         list_for_each_entry_safe(task, tmp, &conn->mgmt_run_list, running) {
2477                 debug_scsi("flushing running mgmt task itt 0x%x\n", task->itt);
2478                 /* release ref from prep task */
2479                 __iscsi_put_task(task);
2480         }
2481
2482         conn->task = NULL;
2483 }
2484
2485 static void iscsi_start_session_recovery(struct iscsi_session *session,
2486                                          struct iscsi_conn *conn, int flag)
2487 {
2488         int old_stop_stage;
2489
2490         del_timer_sync(&conn->transport_timer);
2491
2492         mutex_lock(&session->eh_mutex);
2493         spin_lock_bh(&session->lock);
2494         if (conn->stop_stage == STOP_CONN_TERM) {
2495                 spin_unlock_bh(&session->lock);
2496                 mutex_unlock(&session->eh_mutex);
2497                 return;
2498         }
2499
2500         /*
2501          * When this is called for the in_login state, we only want to clean
2502          * up the login task and connection. We do not need to block and set
2503          * the recovery state again
2504          */
2505         if (flag == STOP_CONN_TERM)
2506                 session->state = ISCSI_STATE_TERMINATE;
2507         else if (conn->stop_stage != STOP_CONN_RECOVER)
2508                 session->state = ISCSI_STATE_IN_RECOVERY;
2509
2510         old_stop_stage = conn->stop_stage;
2511         conn->stop_stage = flag;
2512         conn->c_stage = ISCSI_CONN_STOPPED;
2513         spin_unlock_bh(&session->lock);
2514
2515         iscsi_suspend_tx(conn);
2516         /*
2517          * for connection level recovery we should not calculate
2518          * header digest. conn->hdr_size used for optimization
2519          * in hdr_extract() and will be re-negotiated at
2520          * set_param() time.
2521          */
2522         if (flag == STOP_CONN_RECOVER) {
2523                 conn->hdrdgst_en = 0;
2524                 conn->datadgst_en = 0;
2525                 if (session->state == ISCSI_STATE_IN_RECOVERY &&
2526                     old_stop_stage != STOP_CONN_RECOVER) {
2527                         debug_scsi("blocking session\n");
2528                         iscsi_block_session(session->cls_session);
2529                 }
2530         }
2531
2532         /*
2533          * flush queues.
2534          */
2535         spin_lock_bh(&session->lock);
2536         if (flag == STOP_CONN_RECOVER)
2537                 fail_all_commands(conn, -1, DID_TRANSPORT_DISRUPTED);
2538         else
2539                 fail_all_commands(conn, -1, DID_ERROR);
2540         flush_control_queues(session, conn);
2541         spin_unlock_bh(&session->lock);
2542         mutex_unlock(&session->eh_mutex);
2543 }
2544
2545 void iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
2546 {
2547         struct iscsi_conn *conn = cls_conn->dd_data;
2548         struct iscsi_session *session = conn->session;
2549
2550         switch (flag) {
2551         case STOP_CONN_RECOVER:
2552         case STOP_CONN_TERM:
2553                 iscsi_start_session_recovery(session, conn, flag);
2554                 break;
2555         default:
2556                 iscsi_conn_printk(KERN_ERR, conn,
2557                                   "invalid stop flag %d\n", flag);
2558         }
2559 }
2560 EXPORT_SYMBOL_GPL(iscsi_conn_stop);
2561
2562 int iscsi_conn_bind(struct iscsi_cls_session *cls_session,
2563                     struct iscsi_cls_conn *cls_conn, int is_leading)
2564 {
2565         struct iscsi_session *session = cls_session->dd_data;
2566         struct iscsi_conn *conn = cls_conn->dd_data;
2567
2568         spin_lock_bh(&session->lock);
2569         if (is_leading)
2570                 session->leadconn = conn;
2571         spin_unlock_bh(&session->lock);
2572
2573         /*
2574          * Unblock xmitworker(), Login Phase will pass through.
2575          */
2576         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
2577         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
2578         return 0;
2579 }
2580 EXPORT_SYMBOL_GPL(iscsi_conn_bind);
2581
2582
2583 int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
2584                     enum iscsi_param param, char *buf, int buflen)
2585 {
2586         struct iscsi_conn *conn = cls_conn->dd_data;
2587         struct iscsi_session *session = conn->session;
2588         uint32_t value;
2589
2590         switch(param) {
2591         case ISCSI_PARAM_FAST_ABORT:
2592                 sscanf(buf, "%d", &session->fast_abort);
2593                 break;
2594         case ISCSI_PARAM_ABORT_TMO:
2595                 sscanf(buf, "%d", &session->abort_timeout);
2596                 break;
2597         case ISCSI_PARAM_LU_RESET_TMO:
2598                 sscanf(buf, "%d", &session->lu_reset_timeout);
2599                 break;
2600         case ISCSI_PARAM_PING_TMO:
2601                 sscanf(buf, "%d", &conn->ping_timeout);
2602                 break;
2603         case ISCSI_PARAM_RECV_TMO:
2604                 sscanf(buf, "%d", &conn->recv_timeout);
2605                 break;
2606         case ISCSI_PARAM_MAX_RECV_DLENGTH:
2607                 sscanf(buf, "%d", &conn->max_recv_dlength);
2608                 break;
2609         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
2610                 sscanf(buf, "%d", &conn->max_xmit_dlength);
2611                 break;
2612         case ISCSI_PARAM_HDRDGST_EN:
2613                 sscanf(buf, "%d", &conn->hdrdgst_en);
2614                 break;
2615         case ISCSI_PARAM_DATADGST_EN:
2616                 sscanf(buf, "%d", &conn->datadgst_en);
2617                 break;
2618         case ISCSI_PARAM_INITIAL_R2T_EN:
2619                 sscanf(buf, "%d", &session->initial_r2t_en);
2620                 break;
2621         case ISCSI_PARAM_MAX_R2T:
2622                 sscanf(buf, "%d", &session->max_r2t);
2623                 break;
2624         case ISCSI_PARAM_IMM_DATA_EN:
2625                 sscanf(buf, "%d", &session->imm_data_en);
2626                 break;
2627         case ISCSI_PARAM_FIRST_BURST:
2628                 sscanf(buf, "%d", &session->first_burst);
2629                 break;
2630         case ISCSI_PARAM_MAX_BURST:
2631                 sscanf(buf, "%d", &session->max_burst);
2632                 break;
2633         case ISCSI_PARAM_PDU_INORDER_EN:
2634                 sscanf(buf, "%d", &session->pdu_inorder_en);
2635                 break;
2636         case ISCSI_PARAM_DATASEQ_INORDER_EN:
2637                 sscanf(buf, "%d", &session->dataseq_inorder_en);
2638                 break;
2639         case ISCSI_PARAM_ERL:
2640                 sscanf(buf, "%d", &session->erl);
2641                 break;
2642         case ISCSI_PARAM_IFMARKER_EN:
2643                 sscanf(buf, "%d", &value);
2644                 BUG_ON(value);
2645                 break;
2646         case ISCSI_PARAM_OFMARKER_EN:
2647                 sscanf(buf, "%d", &value);
2648                 BUG_ON(value);
2649                 break;
2650         case ISCSI_PARAM_EXP_STATSN:
2651                 sscanf(buf, "%u", &conn->exp_statsn);
2652                 break;
2653         case ISCSI_PARAM_USERNAME:
2654                 kfree(session->username);
2655                 session->username = kstrdup(buf, GFP_KERNEL);
2656                 if (!session->username)
2657                         return -ENOMEM;
2658                 break;
2659         case ISCSI_PARAM_USERNAME_IN:
2660                 kfree(session->username_in);
2661                 session->username_in = kstrdup(buf, GFP_KERNEL);
2662                 if (!session->username_in)
2663                         return -ENOMEM;
2664                 break;
2665         case ISCSI_PARAM_PASSWORD:
2666                 kfree(session->password);
2667                 session->password = kstrdup(buf, GFP_KERNEL);
2668                 if (!session->password)
2669                         return -ENOMEM;
2670                 break;
2671         case ISCSI_PARAM_PASSWORD_IN:
2672                 kfree(session->password_in);
2673                 session->password_in = kstrdup(buf, GFP_KERNEL);
2674                 if (!session->password_in)
2675                         return -ENOMEM;
2676                 break;
2677         case ISCSI_PARAM_TARGET_NAME:
2678                 /* this should not change between logins */
2679                 if (session->targetname)
2680                         break;
2681
2682                 session->targetname = kstrdup(buf, GFP_KERNEL);
2683                 if (!session->targetname)
2684                         return -ENOMEM;
2685                 break;
2686         case ISCSI_PARAM_TPGT:
2687                 sscanf(buf, "%d", &session->tpgt);
2688                 break;
2689         case ISCSI_PARAM_PERSISTENT_PORT:
2690                 sscanf(buf, "%d", &conn->persistent_port);
2691                 break;
2692         case ISCSI_PARAM_PERSISTENT_ADDRESS:
2693                 /*
2694                  * this is the address returned in discovery so it should
2695                  * not change between logins.
2696                  */
2697                 if (conn->persistent_address)
2698                         break;
2699
2700                 conn->persistent_address = kstrdup(buf, GFP_KERNEL);
2701                 if (!conn->persistent_address)
2702                         return -ENOMEM;
2703                 break;
2704         case ISCSI_PARAM_IFACE_NAME:
2705                 if (!session->ifacename)
2706                         session->ifacename = kstrdup(buf, GFP_KERNEL);
2707                 break;
2708         case ISCSI_PARAM_INITIATOR_NAME:
2709                 if (!session->initiatorname)
2710                         session->initiatorname = kstrdup(buf, GFP_KERNEL);
2711                 break;
2712         default:
2713                 return -ENOSYS;
2714         }
2715
2716         return 0;
2717 }
2718 EXPORT_SYMBOL_GPL(iscsi_set_param);
2719
2720 int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
2721                             enum iscsi_param param, char *buf)
2722 {
2723         struct iscsi_session *session = cls_session->dd_data;
2724         int len;
2725
2726         switch(param) {
2727         case ISCSI_PARAM_FAST_ABORT:
2728                 len = sprintf(buf, "%d\n", session->fast_abort);
2729                 break;
2730         case ISCSI_PARAM_ABORT_TMO:
2731                 len = sprintf(buf, "%d\n", session->abort_timeout);
2732                 break;
2733         case ISCSI_PARAM_LU_RESET_TMO:
2734                 len = sprintf(buf, "%d\n", session->lu_reset_timeout);
2735                 break;
2736         case ISCSI_PARAM_INITIAL_R2T_EN:
2737                 len = sprintf(buf, "%d\n", session->initial_r2t_en);
2738                 break;
2739         case ISCSI_PARAM_MAX_R2T:
2740                 len = sprintf(buf, "%hu\n", session->max_r2t);
2741                 break;
2742         case ISCSI_PARAM_IMM_DATA_EN:
2743                 len = sprintf(buf, "%d\n", session->imm_data_en);
2744                 break;
2745         case ISCSI_PARAM_FIRST_BURST:
2746                 len = sprintf(buf, "%u\n", session->first_burst);
2747                 break;
2748         case ISCSI_PARAM_MAX_BURST:
2749                 len = sprintf(buf, "%u\n", session->max_burst);
2750                 break;
2751         case ISCSI_PARAM_PDU_INORDER_EN:
2752                 len = sprintf(buf, "%d\n", session->pdu_inorder_en);
2753                 break;
2754         case ISCSI_PARAM_DATASEQ_INORDER_EN:
2755                 len = sprintf(buf, "%d\n", session->dataseq_inorder_en);
2756                 break;
2757         case ISCSI_PARAM_ERL:
2758                 len = sprintf(buf, "%d\n", session->erl);
2759                 break;
2760         case ISCSI_PARAM_TARGET_NAME:
2761                 len = sprintf(buf, "%s\n", session->targetname);
2762                 break;
2763         case ISCSI_PARAM_TPGT:
2764                 len = sprintf(buf, "%d\n", session->tpgt);
2765                 break;
2766         case ISCSI_PARAM_USERNAME:
2767                 len = sprintf(buf, "%s\n", session->username);
2768                 break;
2769         case ISCSI_PARAM_USERNAME_IN:
2770                 len = sprintf(buf, "%s\n", session->username_in);
2771                 break;
2772         case ISCSI_PARAM_PASSWORD:
2773                 len = sprintf(buf, "%s\n", session->password);
2774                 break;
2775         case ISCSI_PARAM_PASSWORD_IN:
2776                 len = sprintf(buf, "%s\n", session->password_in);
2777                 break;
2778         case ISCSI_PARAM_IFACE_NAME:
2779                 len = sprintf(buf, "%s\n", session->ifacename);
2780                 break;
2781         case ISCSI_PARAM_INITIATOR_NAME:
2782                 if (!session->initiatorname)
2783                         len = sprintf(buf, "%s\n", "unknown");
2784                 else
2785                         len = sprintf(buf, "%s\n", session->initiatorname);
2786                 break;
2787         default:
2788                 return -ENOSYS;
2789         }
2790
2791         return len;
2792 }
2793 EXPORT_SYMBOL_GPL(iscsi_session_get_param);
2794
2795 int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
2796                          enum iscsi_param param, char *buf)
2797 {
2798         struct iscsi_conn *conn = cls_conn->dd_data;
2799         int len;
2800
2801         switch(param) {
2802         case ISCSI_PARAM_PING_TMO:
2803                 len = sprintf(buf, "%u\n", conn->ping_timeout);
2804                 break;
2805         case ISCSI_PARAM_RECV_TMO:
2806                 len = sprintf(buf, "%u\n", conn->recv_timeout);
2807                 break;
2808         case ISCSI_PARAM_MAX_RECV_DLENGTH:
2809                 len = sprintf(buf, "%u\n", conn->max_recv_dlength);
2810                 break;
2811         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
2812                 len = sprintf(buf, "%u\n", conn->max_xmit_dlength);
2813                 break;
2814         case ISCSI_PARAM_HDRDGST_EN:
2815                 len = sprintf(buf, "%d\n", conn->hdrdgst_en);
2816                 break;
2817         case ISCSI_PARAM_DATADGST_EN:
2818                 len = sprintf(buf, "%d\n", conn->datadgst_en);
2819                 break;
2820         case ISCSI_PARAM_IFMARKER_EN:
2821                 len = sprintf(buf, "%d\n", conn->ifmarker_en);
2822                 break;
2823         case ISCSI_PARAM_OFMARKER_EN:
2824                 len = sprintf(buf, "%d\n", conn->ofmarker_en);
2825                 break;
2826         case ISCSI_PARAM_EXP_STATSN:
2827                 len = sprintf(buf, "%u\n", conn->exp_statsn);
2828                 break;
2829         case ISCSI_PARAM_PERSISTENT_PORT:
2830                 len = sprintf(buf, "%d\n", conn->persistent_port);
2831                 break;
2832         case ISCSI_PARAM_PERSISTENT_ADDRESS:
2833                 len = sprintf(buf, "%s\n", conn->persistent_address);
2834                 break;
2835         default:
2836                 return -ENOSYS;
2837         }
2838
2839         return len;
2840 }
2841 EXPORT_SYMBOL_GPL(iscsi_conn_get_param);
2842
2843 int iscsi_host_get_param(struct Scsi_Host *shost, enum iscsi_host_param param,
2844                          char *buf)
2845 {
2846         struct iscsi_host *ihost = shost_priv(shost);
2847         int len;
2848
2849         switch (param) {
2850         case ISCSI_HOST_PARAM_NETDEV_NAME:
2851                 if (!ihost->netdev)
2852                         len = sprintf(buf, "%s\n", "default");
2853                 else
2854                         len = sprintf(buf, "%s\n", ihost->netdev);
2855                 break;
2856         case ISCSI_HOST_PARAM_HWADDRESS:
2857                 if (!ihost->hwaddress)
2858                         len = sprintf(buf, "%s\n", "default");
2859                 else
2860                         len = sprintf(buf, "%s\n", ihost->hwaddress);
2861                 break;
2862         case ISCSI_HOST_PARAM_INITIATOR_NAME:
2863                 if (!ihost->initiatorname)
2864                         len = sprintf(buf, "%s\n", "unknown");
2865                 else
2866                         len = sprintf(buf, "%s\n", ihost->initiatorname);
2867                 break;
2868         case ISCSI_HOST_PARAM_IPADDRESS:
2869                 if (!strlen(ihost->local_address))
2870                         len = sprintf(buf, "%s\n", "unknown");
2871                 else
2872                         len = sprintf(buf, "%s\n",
2873                                       ihost->local_address);
2874                 break;
2875         default:
2876                 return -ENOSYS;
2877         }
2878
2879         return len;
2880 }
2881 EXPORT_SYMBOL_GPL(iscsi_host_get_param);
2882
2883 int iscsi_host_set_param(struct Scsi_Host *shost, enum iscsi_host_param param,
2884                          char *buf, int buflen)
2885 {
2886         struct iscsi_host *ihost = shost_priv(shost);
2887
2888         switch (param) {
2889         case ISCSI_HOST_PARAM_NETDEV_NAME:
2890                 if (!ihost->netdev)
2891                         ihost->netdev = kstrdup(buf, GFP_KERNEL);
2892                 break;
2893         case ISCSI_HOST_PARAM_HWADDRESS:
2894                 if (!ihost->hwaddress)
2895                         ihost->hwaddress = kstrdup(buf, GFP_KERNEL);
2896                 break;
2897         case ISCSI_HOST_PARAM_INITIATOR_NAME:
2898                 if (!ihost->initiatorname)
2899                         ihost->initiatorname = kstrdup(buf, GFP_KERNEL);
2900                 break;
2901         default:
2902                 return -ENOSYS;
2903         }
2904
2905         return 0;
2906 }
2907 EXPORT_SYMBOL_GPL(iscsi_host_set_param);
2908
2909 MODULE_AUTHOR("Mike Christie");
2910 MODULE_DESCRIPTION("iSCSI library functions");
2911 MODULE_LICENSE("GPL");