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 static int iscsi_dbg_lib;
  42 module_param_named(debug_libiscsi, iscsi_dbg_lib, int, S_IRUGO | S_IWUSR);
  43 MODULE_PARM_DESC(debug_libiscsi, "Turn on debugging for libiscsi module. "
  44                  "Set to 1 to turn on, and zero to turn off. Default "
  45                  "is off.");
  46
  47 #define ISCSI_DBG_CONN(_conn, dbg_fmt, arg...)                  \
  48         do {                                                    \
  49                 if (iscsi_dbg_lib)                              \
  50                         iscsi_conn_printk(KERN_INFO, _conn,     \
  51                                              "%s " dbg_fmt,     \
  52                                              __func__, ##arg);  \
  53         } while (0);
  54
  55 #define ISCSI_DBG_SESSION(_session, dbg_fmt, arg...)                    \
  56         do {                                                            \
  57                 if (iscsi_dbg_lib)                                      \
  58                         iscsi_session_printk(KERN_INFO, _session,       \
  59                                              "%s " dbg_fmt,             \
  60                                              __func__, ##arg);          \
  61         } while (0);
  62
  63 /* Serial Number Arithmetic, 32 bits, less than, RFC1982 */
  64 #define SNA32_CHECK 2147483648UL
  65
  66 static int iscsi_sna_lt(u32 n1, u32 n2)
  67 {
  68         return n1 != n2 && ((n1 < n2 && (n2 - n1 < SNA32_CHECK)) ||
  69                             (n1 > n2 && (n2 - n1 < SNA32_CHECK)));
  70 }
  71
  72 /* Serial Number Arithmetic, 32 bits, less than, RFC1982 */
  73 static int iscsi_sna_lte(u32 n1, u32 n2)
  74 {
  75         return n1 == n2 || ((n1 < n2 && (n2 - n1 < SNA32_CHECK)) ||
  76                             (n1 > n2 && (n2 - n1 < SNA32_CHECK)));
  77 }
  78
  79 inline void iscsi_conn_queue_work(struct iscsi_conn *conn)
  80 {
  81         struct Scsi_Host *shost = conn->session->host;
  82         struct iscsi_host *ihost = shost_priv(shost);
  83
  84         queue_work(ihost->workq, &conn->xmitwork);
  85 }
  86 EXPORT_SYMBOL_GPL(iscsi_conn_queue_work);
  87
  88 void
  89 iscsi_update_cmdsn(struct iscsi_session *session, struct iscsi_nopin *hdr)
  90 {
  91         uint32_t max_cmdsn = be32_to_cpu(hdr->max_cmdsn);
  92         uint32_t exp_cmdsn = be32_to_cpu(hdr->exp_cmdsn);
  93
  94         /*
  95          * standard specifies this check for when to update expected and
  96          * max sequence numbers
  97          */
  98         if (iscsi_sna_lt(max_cmdsn, exp_cmdsn - 1))
  99                 return;
 100
 101         if (exp_cmdsn != session->exp_cmdsn &&
 102             !iscsi_sna_lt(exp_cmdsn, session->exp_cmdsn))
 103                 session->exp_cmdsn = exp_cmdsn;
 104
 105         if (max_cmdsn != session->max_cmdsn &&
 106             !iscsi_sna_lt(max_cmdsn, session->max_cmdsn)) {
 107                 session->max_cmdsn = max_cmdsn;
 108                 /*
 109                  * if the window closed with IO queued, then kick the
 110                  * xmit thread
 111                  */
 112                 if (!list_empty(&session->leadconn->xmitqueue) ||
 113                     !list_empty(&session->leadconn->mgmtqueue)) {
 114                         if (!(session->tt->caps & CAP_DATA_PATH_OFFLOAD))
 115                                 iscsi_conn_queue_work(session->leadconn);
 116                 }
 117         }
 118 }
 119 EXPORT_SYMBOL_GPL(iscsi_update_cmdsn);
 120
 121 /**
 122  * iscsi_prep_data_out_pdu - initialize Data-Out
 123  * @task: scsi command task
 124  * @r2t: R2T info
 125  * @hdr: iscsi data in pdu
 126  *
 127  * Notes:
 128  *      Initialize Data-Out within this R2T sequence and finds
 129  *      proper data_offset within this SCSI command.
 130  *
 131  *      This function is called with connection lock taken.
 132  **/
 133 void iscsi_prep_data_out_pdu(struct iscsi_task *task, struct iscsi_r2t_info *r2t,
 134                            struct iscsi_data *hdr)
 135 {
 136         struct iscsi_conn *conn = task->conn;
 137         unsigned int left = r2t->data_length - r2t->sent;
 138
 139         task->hdr_len = sizeof(struct iscsi_data);
 140
 141         memset(hdr, 0, sizeof(struct iscsi_data));
 142         hdr->ttt = r2t->ttt;
 143         hdr->datasn = cpu_to_be32(r2t->datasn);
 144         r2t->datasn++;
 145         hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
 146         memcpy(hdr->lun, task->lun, sizeof(hdr->lun));
 147         hdr->itt = task->hdr_itt;
 148         hdr->exp_statsn = r2t->exp_statsn;
 149         hdr->offset = cpu_to_be32(r2t->data_offset + r2t->sent);
 150         if (left > conn->max_xmit_dlength) {
 151                 hton24(hdr->dlength, conn->max_xmit_dlength);
 152                 r2t->data_count = conn->max_xmit_dlength;
 153                 hdr->flags = 0;
 154         } else {
 155                 hton24(hdr->dlength, left);
 156                 r2t->data_count = left;
 157                 hdr->flags = ISCSI_FLAG_CMD_FINAL;
 158         }
 159         conn->dataout_pdus_cnt++;
 160 }
 161 EXPORT_SYMBOL_GPL(iscsi_prep_data_out_pdu);
 162
 163 static int iscsi_add_hdr(struct iscsi_task *task, unsigned len)
 164 {
 165         unsigned exp_len = task->hdr_len + len;
 166
 167         if (exp_len > task->hdr_max) {
 168                 WARN_ON(1);
 169                 return -EINVAL;
 170         }
 171
 172         WARN_ON(len & (ISCSI_PAD_LEN - 1)); /* caller must pad the AHS */
 173         task->hdr_len = exp_len;
 174         return 0;
 175 }
 176
 177 /*
 178  * make an extended cdb AHS
 179  */
 180 static int iscsi_prep_ecdb_ahs(struct iscsi_task *task)
 181 {
 182         struct scsi_cmnd *cmd = task->sc;
 183         unsigned rlen, pad_len;
 184         unsigned short ahslength;
 185         struct iscsi_ecdb_ahdr *ecdb_ahdr;
 186         int rc;
 187
 188         ecdb_ahdr = iscsi_next_hdr(task);
 189         rlen = cmd->cmd_len - ISCSI_CDB_SIZE;
 190
 191         BUG_ON(rlen > sizeof(ecdb_ahdr->ecdb));
 192         ahslength = rlen + sizeof(ecdb_ahdr->reserved);
 193
 194         pad_len = iscsi_padding(rlen);
 195
 196         rc = iscsi_add_hdr(task, sizeof(ecdb_ahdr->ahslength) +
 197                            sizeof(ecdb_ahdr->ahstype) + ahslength + pad_len);
 198         if (rc)
 199                 return rc;
 200
 201         if (pad_len)
 202                 memset(&ecdb_ahdr->ecdb[rlen], 0, pad_len);
 203
 204         ecdb_ahdr->ahslength = cpu_to_be16(ahslength);
 205         ecdb_ahdr->ahstype = ISCSI_AHSTYPE_CDB;
 206         ecdb_ahdr->reserved = 0;
 207         memcpy(ecdb_ahdr->ecdb, cmd->cmnd + ISCSI_CDB_SIZE, rlen);
 208
 209         ISCSI_DBG_SESSION(task->conn->session,
 210                           "iscsi_prep_ecdb_ahs: varlen_cdb_len %d "
 211                           "rlen %d pad_len %d ahs_length %d iscsi_headers_size "
 212                           "%u\n", cmd->cmd_len, rlen, pad_len, ahslength,
 213                           task->hdr_len);
 214         return 0;
 215 }
 216
 217 static int iscsi_prep_bidi_ahs(struct iscsi_task *task)
 218 {
 219         struct scsi_cmnd *sc = task->sc;
 220         struct iscsi_rlength_ahdr *rlen_ahdr;
 221         int rc;
 222
 223         rlen_ahdr = iscsi_next_hdr(task);
 224         rc = iscsi_add_hdr(task, sizeof(*rlen_ahdr));
 225         if (rc)
 226                 return rc;
 227
 228         rlen_ahdr->ahslength =
 229                 cpu_to_be16(sizeof(rlen_ahdr->read_length) +
 230                                                   sizeof(rlen_ahdr->reserved));
 231         rlen_ahdr->ahstype = ISCSI_AHSTYPE_RLENGTH;
 232         rlen_ahdr->reserved = 0;
 233         rlen_ahdr->read_length = cpu_to_be32(scsi_in(sc)->length);
 234
 235         ISCSI_DBG_SESSION(task->conn->session,
 236                           "bidi-in rlen_ahdr->read_length(%d) "
 237                           "rlen_ahdr->ahslength(%d)\n",
 238                           be32_to_cpu(rlen_ahdr->read_length),
 239                           be16_to_cpu(rlen_ahdr->ahslength));
 240         return 0;
 241 }
 242
 243 /**
 244  * iscsi_prep_scsi_cmd_pdu - prep iscsi scsi cmd pdu
 245  * @task: iscsi task
 246  *
 247  * Prep basic iSCSI PDU fields for a scsi cmd pdu. The LLD should set
 248  * fields like dlength or final based on how much data it sends
 249  */
 250 static int iscsi_prep_scsi_cmd_pdu(struct iscsi_task *task)
 251 {
 252         struct iscsi_conn *conn = task->conn;
 253         struct iscsi_session *session = conn->session;
 254         struct scsi_cmnd *sc = task->sc;
 255         struct iscsi_cmd *hdr;
 256         unsigned hdrlength, cmd_len;
 257         itt_t itt;
 258         int rc;
 259
 260         rc = conn->session->tt->alloc_pdu(task, ISCSI_OP_SCSI_CMD);
 261         if (rc)
 262                 return rc;
 263         hdr = (struct iscsi_cmd *) task->hdr;
 264         itt = hdr->itt;
 265         memset(hdr, 0, sizeof(*hdr));
 266
 267         if (session->tt->parse_pdu_itt)
 268                 hdr->itt = task->hdr_itt = itt;
 269         else
 270                 hdr->itt = task->hdr_itt = build_itt(task->itt,
 271                                                      task->conn->session->age);
 272         task->hdr_len = 0;
 273         rc = iscsi_add_hdr(task, sizeof(*hdr));
 274         if (rc)
 275                 return rc;
 276         hdr->opcode = ISCSI_OP_SCSI_CMD;
 277         hdr->flags = ISCSI_ATTR_SIMPLE;
 278         int_to_scsilun(sc->device->lun, (struct scsi_lun *)hdr->lun);
 279         memcpy(task->lun, hdr->lun, sizeof(task->lun));
 280         hdr->cmdsn = task->cmdsn = cpu_to_be32(session->cmdsn);
 281         session->cmdsn++;
 282         hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
 283         cmd_len = sc->cmd_len;
 284         if (cmd_len < ISCSI_CDB_SIZE)
 285                 memset(&hdr->cdb[cmd_len], 0, ISCSI_CDB_SIZE - cmd_len);
 286         else if (cmd_len > ISCSI_CDB_SIZE) {
 287                 rc = iscsi_prep_ecdb_ahs(task);
 288                 if (rc)
 289                         return rc;
 290                 cmd_len = ISCSI_CDB_SIZE;
 291         }
 292         memcpy(hdr->cdb, sc->cmnd, cmd_len);
 293
 294         task->imm_count = 0;
 295         if (scsi_bidi_cmnd(sc)) {
 296                 hdr->flags |= ISCSI_FLAG_CMD_READ;
 297                 rc = iscsi_prep_bidi_ahs(task);
 298                 if (rc)
 299                         return rc;
 300         }
 301         if (sc->sc_data_direction == DMA_TO_DEVICE) {
 302                 unsigned out_len = scsi_out(sc)->length;
 303                 struct iscsi_r2t_info *r2t = &task->unsol_r2t;
 304
 305                 hdr->data_length = cpu_to_be32(out_len);
 306                 hdr->flags |= ISCSI_FLAG_CMD_WRITE;
 307                 /*
 308                  * Write counters:
 309                  *
 310                  *      imm_count       bytes to be sent right after
 311                  *                      SCSI PDU Header
 312                  *
 313                  *      unsol_count     bytes(as Data-Out) to be sent
 314                  *                      without R2T ack right after
 315                  *                      immediate data
 316                  *
 317                  *      r2t data_length bytes to be sent via R2T ack's
 318                  *
 319                  *      pad_count       bytes to be sent as zero-padding
 320                  */
 321                 memset(r2t, 0, sizeof(*r2t));
 322
 323                 if (session->imm_data_en) {
 324                         if (out_len >= session->first_burst)
 325                                 task->imm_count = min(session->first_burst,
 326                                                         conn->max_xmit_dlength);
 327                         else
 328                                 task->imm_count = min(out_len,
 329                                                         conn->max_xmit_dlength);
 330                         hton24(hdr->dlength, task->imm_count);
 331                 } else
 332                         zero_data(hdr->dlength);
 333
 334                 if (!session->initial_r2t_en) {
 335                         r2t->data_length = min(session->first_burst, out_len) -
 336                                                task->imm_count;
 337                         r2t->data_offset = task->imm_count;
 338                         r2t->ttt = cpu_to_be32(ISCSI_RESERVED_TAG);
 339                         r2t->exp_statsn = cpu_to_be32(conn->exp_statsn);
 340                 }
 341
 342                 if (!task->unsol_r2t.data_length)
 343                         /* No unsolicit Data-Out's */
 344                         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
 345         } else {
 346                 hdr->flags |= ISCSI_FLAG_CMD_FINAL;
 347                 zero_data(hdr->dlength);
 348                 hdr->data_length = cpu_to_be32(scsi_in(sc)->length);
 349
 350                 if (sc->sc_data_direction == DMA_FROM_DEVICE)
 351                         hdr->flags |= ISCSI_FLAG_CMD_READ;
 352         }
 353
 354         /* calculate size of additional header segments (AHSs) */
 355         hdrlength = task->hdr_len - sizeof(*hdr);
 356
 357         WARN_ON(hdrlength & (ISCSI_PAD_LEN-1));
 358         hdrlength /= ISCSI_PAD_LEN;
 359
 360         WARN_ON(hdrlength >= 256);
 361         hdr->hlength = hdrlength & 0xFF;
 362
 363         if (session->tt->init_task && session->tt->init_task(task))
 364                 return -EIO;
 365
 366         task->state = ISCSI_TASK_RUNNING;
 367         list_move_tail(&task->running, &conn->run_list);
 368
 369         conn->scsicmd_pdus_cnt++;
 370         ISCSI_DBG_SESSION(session, "iscsi prep [%s cid %d sc %p cdb 0x%x "
 371                           "itt 0x%x len %d bidi_len %d cmdsn %d win %d]\n",
 372                           scsi_bidi_cmnd(sc) ? "bidirectional" :
 373                           sc->sc_data_direction == DMA_TO_DEVICE ?
 374                           "write" : "read", conn->id, sc, sc->cmnd[0],
 375                           task->itt, scsi_bufflen(sc),
 376                           scsi_bidi_cmnd(sc) ? scsi_in(sc)->length : 0,
 377                           session->cmdsn,
 378                           session->max_cmdsn - session->exp_cmdsn + 1);
 379         return 0;
 380 }
 381
 382 /**
 383  * iscsi_complete_command - finish a task
 384  * @task: iscsi cmd task
 385  *
 386  * Must be called with session lock.
 387  * This function returns the scsi command to scsi-ml or cleans
 388  * up mgmt tasks then returns the task to the pool.
 389  */
 390 static void iscsi_complete_command(struct iscsi_task *task)
 391 {
 392         struct iscsi_conn *conn = task->conn;
 393         struct iscsi_session *session = conn->session;
 394         struct scsi_cmnd *sc = task->sc;
 395
 396         session->tt->cleanup_task(task);
 397         list_del_init(&task->running);
 398         task->state = ISCSI_TASK_COMPLETED;
 399         task->sc = NULL;
 400
 401         if (conn->task == task)
 402                 conn->task = NULL;
 403         /*
 404          * login task is preallocated so do not free
 405          */
 406         if (conn->login_task == task)
 407                 return;
 408
 409         __kfifo_put(session->cmdpool.queue, (void*)&task, sizeof(void*));
 410
 411         if (conn->ping_task == task)
 412                 conn->ping_task = NULL;
 413
 414         if (sc) {
 415                 task->sc = NULL;
 416                 /* SCSI eh reuses commands to verify us */
 417                 sc->SCp.ptr = NULL;
 418                 /*
 419                  * queue command may call this to free the task, but
 420                  * not have setup the sc callback
 421                  */
 422                 if (sc->scsi_done)
 423                         sc->scsi_done(sc);
 424         }
 425 }
 426
 427 void __iscsi_get_task(struct iscsi_task *task)
 428 {
 429         atomic_inc(&task->refcount);
 430 }
 431 EXPORT_SYMBOL_GPL(__iscsi_get_task);
 432
 433 static void __iscsi_put_task(struct iscsi_task *task)
 434 {
 435         if (atomic_dec_and_test(&task->refcount))
 436                 iscsi_complete_command(task);
 437 }
 438
 439 void iscsi_put_task(struct iscsi_task *task)
 440 {
 441         struct iscsi_session *session = task->conn->session;
 442
 443         spin_lock_bh(&session->lock);
 444         __iscsi_put_task(task);
 445         spin_unlock_bh(&session->lock);
 446 }
 447 EXPORT_SYMBOL_GPL(iscsi_put_task);
 448
 449 /*
 450  * session lock must be held
 451  */
 452 static void fail_command(struct iscsi_conn *conn, struct iscsi_task *task,
 453                          int err)
 454 {
 455         struct scsi_cmnd *sc;
 456
 457         sc = task->sc;
 458         if (!sc)
 459                 return;
 460
 461         if (task->state == ISCSI_TASK_PENDING)
 462                 /*
 463                  * cmd never made it to the xmit thread, so we should not count
 464                  * the cmd in the sequencing
 465                  */
 466                 conn->session->queued_cmdsn--;
 467
 468         sc->result = err;
 469         if (!scsi_bidi_cmnd(sc))
 470                 scsi_set_resid(sc, scsi_bufflen(sc));
 471         else {
 472                 scsi_out(sc)->resid = scsi_out(sc)->length;
 473                 scsi_in(sc)->resid = scsi_in(sc)->length;
 474         }
 475
 476         if (conn->task == task)
 477                 conn->task = NULL;
 478         /* release ref from queuecommand */
 479         __iscsi_put_task(task);
 480 }
 481
 482 static int iscsi_prep_mgmt_task(struct iscsi_conn *conn,
 483                                 struct iscsi_task *task)
 484 {
 485         struct iscsi_session *session = conn->session;
 486         struct iscsi_hdr *hdr = task->hdr;
 487         struct iscsi_nopout *nop = (struct iscsi_nopout *)hdr;
 488
 489         if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
 490                 return -ENOTCONN;
 491
 492         if (hdr->opcode != (ISCSI_OP_LOGIN | ISCSI_OP_IMMEDIATE) &&
 493             hdr->opcode != (ISCSI_OP_TEXT | ISCSI_OP_IMMEDIATE))
 494                 nop->exp_statsn = cpu_to_be32(conn->exp_statsn);
 495         /*
 496          * pre-format CmdSN for outgoing PDU.
 497          */
 498         nop->cmdsn = cpu_to_be32(session->cmdsn);
 499         if (hdr->itt != RESERVED_ITT) {
 500                 /*
 501                  * TODO: We always use immediate, so we never hit this.
 502                  * If we start to send tmfs or nops as non-immediate then
 503                  * we should start checking the cmdsn numbers for mgmt tasks.
 504                  */
 505                 if (conn->c_stage == ISCSI_CONN_STARTED &&
 506                     !(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
 507                         session->queued_cmdsn++;
 508                         session->cmdsn++;
 509                 }
 510         }
 511
 512         if (session->tt->init_task && session->tt->init_task(task))
 513                 return -EIO;
 514
 515         if ((hdr->opcode & ISCSI_OPCODE_MASK) == ISCSI_OP_LOGOUT)
 516                 session->state = ISCSI_STATE_LOGGING_OUT;
 517
 518         task->state = ISCSI_TASK_RUNNING;
 519         list_move_tail(&task->running, &conn->mgmt_run_list);
 520         ISCSI_DBG_SESSION(session, "mgmtpdu [op 0x%x hdr->itt 0x%x "
 521                           "datalen %d]\n", hdr->opcode & ISCSI_OPCODE_MASK,
 522                           hdr->itt, task->data_count);
 523         return 0;
 524 }
 525
 526 static struct iscsi_task *
 527 __iscsi_conn_send_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 528                       char *data, uint32_t data_size)
 529 {
 530         struct iscsi_session *session = conn->session;
 531         struct iscsi_task *task;
 532         itt_t itt;
 533
 534         if (session->state == ISCSI_STATE_TERMINATE)
 535                 return NULL;
 536
 537         if (hdr->opcode == (ISCSI_OP_LOGIN | ISCSI_OP_IMMEDIATE) ||
 538             hdr->opcode == (ISCSI_OP_TEXT | ISCSI_OP_IMMEDIATE))
 539                 /*
 540                  * Login and Text are sent serially, in
 541                  * request-followed-by-response sequence.
 542                  * Same task can be used. Same ITT must be used.
 543                  * Note that login_task is preallocated at conn_create().
 544                  */
 545                 task = conn->login_task;
 546         else {
 547                 BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
 548                 BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);
 549
 550                 if (!__kfifo_get(session->cmdpool.queue,
 551                                  (void*)&task, sizeof(void*)))
 552                         return NULL;
 553         }
 554         /*
 555          * released in complete pdu for task we expect a response for, and
 556          * released by the lld when it has transmitted the task for
 557          * pdus we do not expect a response for.
 558          */
 559         atomic_set(&task->refcount, 1);
 560         task->conn = conn;
 561         task->sc = NULL;
 562
 563         if (data_size) {
 564                 memcpy(task->data, data, data_size);
 565                 task->data_count = data_size;
 566         } else
 567                 task->data_count = 0;
 568
 569         if (conn->session->tt->alloc_pdu(task, hdr->opcode)) {
 570                 iscsi_conn_printk(KERN_ERR, conn, "Could not allocate "
 571                                  "pdu for mgmt task.\n");
 572                 goto requeue_task;
 573         }
 574         itt = task->hdr->itt;
 575         task->hdr_len = sizeof(struct iscsi_hdr);
 576         memcpy(task->hdr, hdr, sizeof(struct iscsi_hdr));
 577
 578         if (hdr->itt != RESERVED_ITT) {
 579                 if (session->tt->parse_pdu_itt)
 580                         task->hdr->itt = itt;
 581                 else
 582                         task->hdr->itt = build_itt(task->itt,
 583                                                    task->conn->session->age);
 584         }
 585
 586         INIT_LIST_HEAD(&task->running);
 587         list_add_tail(&task->running, &conn->mgmtqueue);
 588
 589         if (session->tt->caps & CAP_DATA_PATH_OFFLOAD) {
 590                 if (iscsi_prep_mgmt_task(conn, task))
 591                         goto free_task;
 592
 593                 if (session->tt->xmit_task(task))
 594                         goto free_task;
 595
 596         } else
 597                 iscsi_conn_queue_work(conn);
 598
 599         return task;
 600
 601 free_task:
 602         __iscsi_put_task(task);
 603         return NULL;
 604
 605 requeue_task:
 606         if (task != conn->login_task)
 607                 __kfifo_put(session->cmdpool.queue, (void*)&task,
 608                             sizeof(void*));
 609         return NULL;
 610 }
 611
 612 int iscsi_conn_send_pdu(struct iscsi_cls_conn *cls_conn, struct iscsi_hdr *hdr,
 613                         char *data, uint32_t data_size)
 614 {
 615         struct iscsi_conn *conn = cls_conn->dd_data;
 616         struct iscsi_session *session = conn->session;
 617         int err = 0;
 618
 619         spin_lock_bh(&session->lock);
 620         if (!__iscsi_conn_send_pdu(conn, hdr, data, data_size))
 621                 err = -EPERM;
 622         spin_unlock_bh(&session->lock);
 623         return err;
 624 }
 625 EXPORT_SYMBOL_GPL(iscsi_conn_send_pdu);
 626
 627 /**
 628  * iscsi_cmd_rsp - SCSI Command Response processing
 629  * @conn: iscsi connection
 630  * @hdr: iscsi header
 631  * @task: scsi command task
 632  * @data: cmd data buffer
 633  * @datalen: len of buffer
 634  *
 635  * iscsi_cmd_rsp sets up the scsi_cmnd fields based on the PDU and
 636  * then completes the command and task.
 637  **/
 638 static void iscsi_scsi_cmd_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 639                                struct iscsi_task *task, char *data,
 640                                int datalen)
 641 {
 642         struct iscsi_cmd_rsp *rhdr = (struct iscsi_cmd_rsp *)hdr;
 643         struct iscsi_session *session = conn->session;
 644         struct scsi_cmnd *sc = task->sc;
 645
 646         iscsi_update_cmdsn(session, (struct iscsi_nopin*)rhdr);
 647         conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 648
 649         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 650
 651         if (rhdr->response != ISCSI_STATUS_CMD_COMPLETED) {
 652                 sc->result = DID_ERROR << 16;
 653                 goto out;
 654         }
 655
 656         if (rhdr->cmd_status == SAM_STAT_CHECK_CONDITION) {
 657                 uint16_t senselen;
 658
 659                 if (datalen < 2) {
 660 invalid_datalen:
 661                         iscsi_conn_printk(KERN_ERR,  conn,
 662                                          "Got CHECK_CONDITION but invalid data "
 663                                          "buffer size of %d\n", datalen);
 664                         sc->result = DID_BAD_TARGET << 16;
 665                         goto out;
 666                 }
 667
 668                 senselen = get_unaligned_be16(data);
 669                 if (datalen < senselen)
 670                         goto invalid_datalen;
 671
 672                 memcpy(sc->sense_buffer, data + 2,
 673                        min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
 674                 ISCSI_DBG_SESSION(session, "copied %d bytes of sense\n",
 675                                   min_t(uint16_t, senselen,
 676                                   SCSI_SENSE_BUFFERSIZE));
 677         }
 678
 679         if (rhdr->flags & (ISCSI_FLAG_CMD_BIDI_UNDERFLOW |
 680                            ISCSI_FLAG_CMD_BIDI_OVERFLOW)) {
 681                 int res_count = be32_to_cpu(rhdr->bi_residual_count);
 682
 683                 if (scsi_bidi_cmnd(sc) && res_count > 0 &&
 684                                 (rhdr->flags & ISCSI_FLAG_CMD_BIDI_OVERFLOW ||
 685                                  res_count <= scsi_in(sc)->length))
 686                         scsi_in(sc)->resid = res_count;
 687                 else
 688                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 689         }
 690
 691         if (rhdr->flags & (ISCSI_FLAG_CMD_UNDERFLOW |
 692                            ISCSI_FLAG_CMD_OVERFLOW)) {
 693                 int res_count = be32_to_cpu(rhdr->residual_count);
 694
 695                 if (res_count > 0 &&
 696                     (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
 697                      res_count <= scsi_bufflen(sc)))
 698                         /* write side for bidi or uni-io set_resid */
 699                         scsi_set_resid(sc, res_count);
 700                 else
 701                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 702         }
 703 out:
 704         ISCSI_DBG_SESSION(session, "done [sc %p res %d itt 0x%x]\n",
 705                           sc, sc->result, task->itt);
 706         conn->scsirsp_pdus_cnt++;
 707
 708         __iscsi_put_task(task);
 709 }
 710
 711 /**
 712  * iscsi_data_in_rsp - SCSI Data-In Response processing
 713  * @conn: iscsi connection
 714  * @hdr:  iscsi pdu
 715  * @task: scsi command task
 716  **/
 717 static void
 718 iscsi_data_in_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 719                   struct iscsi_task *task)
 720 {
 721         struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)hdr;
 722         struct scsi_cmnd *sc = task->sc;
 723
 724         if (!(rhdr->flags & ISCSI_FLAG_DATA_STATUS))
 725                 return;
 726
 727         sc->result = (DID_OK << 16) | rhdr->cmd_status;
 728         conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 729         if (rhdr->flags & (ISCSI_FLAG_DATA_UNDERFLOW |
 730                            ISCSI_FLAG_DATA_OVERFLOW)) {
 731                 int res_count = be32_to_cpu(rhdr->residual_count);
 732
 733                 if (res_count > 0 &&
 734                     (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
 735                      res_count <= scsi_in(sc)->length))
 736                         scsi_in(sc)->resid = res_count;
 737                 else
 738                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
 739         }
 740
 741         conn->scsirsp_pdus_cnt++;
 742         __iscsi_put_task(task);
 743 }
 744
 745 static void iscsi_tmf_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
 746 {
 747         struct iscsi_tm_rsp *tmf = (struct iscsi_tm_rsp *)hdr;
 748
 749         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 750         conn->tmfrsp_pdus_cnt++;
 751
 752         if (conn->tmf_state != TMF_QUEUED)
 753                 return;
 754
 755         if (tmf->response == ISCSI_TMF_RSP_COMPLETE)
 756                 conn->tmf_state = TMF_SUCCESS;
 757         else if (tmf->response == ISCSI_TMF_RSP_NO_TASK)
 758                 conn->tmf_state = TMF_NOT_FOUND;
 759         else
 760                 conn->tmf_state = TMF_FAILED;
 761         wake_up(&conn->ehwait);
 762 }
 763
 764 static void iscsi_send_nopout(struct iscsi_conn *conn, struct iscsi_nopin *rhdr)
 765 {
 766         struct iscsi_nopout hdr;
 767         struct iscsi_task *task;
 768
 769         if (!rhdr && conn->ping_task)
 770                 return;
 771
 772         memset(&hdr, 0, sizeof(struct iscsi_nopout));
 773         hdr.opcode = ISCSI_OP_NOOP_OUT | ISCSI_OP_IMMEDIATE;
 774         hdr.flags = ISCSI_FLAG_CMD_FINAL;
 775
 776         if (rhdr) {
 777                 memcpy(hdr.lun, rhdr->lun, 8);
 778                 hdr.ttt = rhdr->ttt;
 779                 hdr.itt = RESERVED_ITT;
 780         } else
 781                 hdr.ttt = RESERVED_ITT;
 782
 783         task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)&hdr, NULL, 0);
 784         if (!task)
 785                 iscsi_conn_printk(KERN_ERR, conn, "Could not send nopout\n");
 786         else if (!rhdr) {
 787                 /* only track our nops */
 788                 conn->ping_task = task;
 789                 conn->last_ping = jiffies;
 790         }
 791 }
 792
 793 static int iscsi_handle_reject(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 794                                char *data, int datalen)
 795 {
 796         struct iscsi_reject *reject = (struct iscsi_reject *)hdr;
 797         struct iscsi_hdr rejected_pdu;
 798
 799         conn->exp_statsn = be32_to_cpu(reject->statsn) + 1;
 800
 801         if (reject->reason == ISCSI_REASON_DATA_DIGEST_ERROR) {
 802                 if (ntoh24(reject->dlength) > datalen)
 803                         return ISCSI_ERR_PROTO;
 804
 805                 if (ntoh24(reject->dlength) >= sizeof(struct iscsi_hdr)) {
 806                         memcpy(&rejected_pdu, data, sizeof(struct iscsi_hdr));
 807                         iscsi_conn_printk(KERN_ERR, conn,
 808                                           "pdu (op 0x%x) rejected "
 809                                           "due to DataDigest error.\n",
 810                                           rejected_pdu.opcode);
 811                 }
 812         }
 813         return 0;
 814 }
 815
 816 /**
 817  * iscsi_itt_to_task - look up task by itt
 818  * @conn: iscsi connection
 819  * @itt: itt
 820  *
 821  * This should be used for mgmt tasks like login and nops, or if
 822  * the LDD's itt space does not include the session age.
 823  *
 824  * The session lock must be held.
 825  */
 826 static struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *conn, itt_t itt)
 827 {
 828         struct iscsi_session *session = conn->session;
 829         int i;
 830
 831         if (itt == RESERVED_ITT)
 832                 return NULL;
 833
 834         if (session->tt->parse_pdu_itt)
 835                 session->tt->parse_pdu_itt(conn, itt, &i, NULL);
 836         else
 837                 i = get_itt(itt);
 838         if (i >= session->cmds_max)
 839                 return NULL;
 840
 841         return session->cmds[i];
 842 }
 843
 844 /**
 845  * __iscsi_complete_pdu - complete pdu
 846  * @conn: iscsi conn
 847  * @hdr: iscsi header
 848  * @data: data buffer
 849  * @datalen: len of data buffer
 850  *
 851  * Completes pdu processing by freeing any resources allocated at
 852  * queuecommand or send generic. session lock must be held and verify
 853  * itt must have been called.
 854  */
 855 int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 856                          char *data, int datalen)
 857 {
 858         struct iscsi_session *session = conn->session;
 859         int opcode = hdr->opcode & ISCSI_OPCODE_MASK, rc = 0;
 860         struct iscsi_task *task;
 861         uint32_t itt;
 862
 863         conn->last_recv = jiffies;
 864         rc = iscsi_verify_itt(conn, hdr->itt);
 865         if (rc)
 866                 return rc;
 867
 868         if (hdr->itt != RESERVED_ITT)
 869                 itt = get_itt(hdr->itt);
 870         else
 871                 itt = ~0U;
 872
 873         ISCSI_DBG_SESSION(session, "[op 0x%x cid %d itt 0x%x len %d]\n",
 874                           opcode, conn->id, itt, datalen);
 875
 876         if (itt == ~0U) {
 877                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
 878
 879                 switch(opcode) {
 880                 case ISCSI_OP_NOOP_IN:
 881                         if (datalen) {
 882                                 rc = ISCSI_ERR_PROTO;
 883                                 break;
 884                         }
 885
 886                         if (hdr->ttt == cpu_to_be32(ISCSI_RESERVED_TAG))
 887                                 break;
 888
 889                         iscsi_send_nopout(conn, (struct iscsi_nopin*)hdr);
 890                         break;
 891                 case ISCSI_OP_REJECT:
 892                         rc = iscsi_handle_reject(conn, hdr, data, datalen);
 893                         break;
 894                 case ISCSI_OP_ASYNC_EVENT:
 895                         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 896                         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
 897                                 rc = ISCSI_ERR_CONN_FAILED;
 898                         break;
 899                 default:
 900                         rc = ISCSI_ERR_BAD_OPCODE;
 901                         break;
 902                 }
 903                 goto out;
 904         }
 905
 906         switch(opcode) {
 907         case ISCSI_OP_SCSI_CMD_RSP:
 908         case ISCSI_OP_SCSI_DATA_IN:
 909                 task = iscsi_itt_to_ctask(conn, hdr->itt);
 910                 if (!task)
 911                         return ISCSI_ERR_BAD_ITT;
 912                 break;
 913         case ISCSI_OP_R2T:
 914                 /*
 915                  * LLD handles R2Ts if they need to.
 916                  */
 917                 return 0;
 918         case ISCSI_OP_LOGOUT_RSP:
 919         case ISCSI_OP_LOGIN_RSP:
 920         case ISCSI_OP_TEXT_RSP:
 921         case ISCSI_OP_SCSI_TMFUNC_RSP:
 922         case ISCSI_OP_NOOP_IN:
 923                 task = iscsi_itt_to_task(conn, hdr->itt);
 924                 if (!task)
 925                         return ISCSI_ERR_BAD_ITT;
 926                 break;
 927         default:
 928                 return ISCSI_ERR_BAD_OPCODE;
 929         }
 930
 931         switch(opcode) {
 932         case ISCSI_OP_SCSI_CMD_RSP:
 933                 iscsi_scsi_cmd_rsp(conn, hdr, task, data, datalen);
 934                 break;
 935         case ISCSI_OP_SCSI_DATA_IN:
 936                 iscsi_data_in_rsp(conn, hdr, task);
 937                 break;
 938         case ISCSI_OP_LOGOUT_RSP:
 939                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
 940                 if (datalen) {
 941                         rc = ISCSI_ERR_PROTO;
 942                         break;
 943                 }
 944                 conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 945                 goto recv_pdu;
 946         case ISCSI_OP_LOGIN_RSP:
 947         case ISCSI_OP_TEXT_RSP:
 948                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
 949                 /*
 950                  * login related PDU's exp_statsn is handled in
 951                  * userspace
 952                  */
 953                 goto recv_pdu;
 954         case ISCSI_OP_SCSI_TMFUNC_RSP:
 955                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
 956                 if (datalen) {
 957                         rc = ISCSI_ERR_PROTO;
 958                         break;
 959                 }
 960
 961                 iscsi_tmf_rsp(conn, hdr);
 962                 __iscsi_put_task(task);
 963                 break;
 964         case ISCSI_OP_NOOP_IN:
 965                 iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
 966                 if (hdr->ttt != cpu_to_be32(ISCSI_RESERVED_TAG) || datalen) {
 967                         rc = ISCSI_ERR_PROTO;
 968                         break;
 969                 }
 970                 conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
 971
 972                 if (conn->ping_task != task)
 973                         /*
 974                          * If this is not in response to one of our
 975                          * nops then it must be from userspace.
 976                          */
 977                         goto recv_pdu;
 978
 979                 mod_timer(&conn->transport_timer, jiffies + conn->recv_timeout);
 980                 __iscsi_put_task(task);
 981                 break;
 982         default:
 983                 rc = ISCSI_ERR_BAD_OPCODE;
 984                 break;
 985         }
 986
 987 out:
 988         return rc;
 989 recv_pdu:
 990         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
 991                 rc = ISCSI_ERR_CONN_FAILED;
 992         __iscsi_put_task(task);
 993         return rc;
 994 }
 995 EXPORT_SYMBOL_GPL(__iscsi_complete_pdu);
 996
 997 int iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 998                        char *data, int datalen)
 999 {
1000         int rc;
1001
1002         spin_lock(&conn->session->lock);
1003         rc = __iscsi_complete_pdu(conn, hdr, data, datalen);
1004         spin_unlock(&conn->session->lock);
1005         return rc;
1006 }
1007 EXPORT_SYMBOL_GPL(iscsi_complete_pdu);
1008
1009 int iscsi_verify_itt(struct iscsi_conn *conn, itt_t itt)
1010 {
1011         struct iscsi_session *session = conn->session;
1012         int age = 0, i = 0;
1013
1014         if (itt == RESERVED_ITT)
1015                 return 0;
1016
1017         if (session->tt->parse_pdu_itt)
1018                 session->tt->parse_pdu_itt(conn, itt, &i, &age);
1019         else {
1020                 i = get_itt(itt);
1021                 age = ((__force u32)itt >> ISCSI_AGE_SHIFT) & ISCSI_AGE_MASK;
1022         }
1023
1024         if (age != session->age) {
1025                 iscsi_conn_printk(KERN_ERR, conn,
1026                                   "received itt %x expected session age (%x)\n",
1027                                   (__force u32)itt, session->age);
1028                 return ISCSI_ERR_BAD_ITT;
1029         }
1030
1031         if (i >= session->cmds_max) {
1032                 iscsi_conn_printk(KERN_ERR, conn,
1033                                   "received invalid itt index %u (max cmds "
1034                                    "%u.\n", i, session->cmds_max);
1035                 return ISCSI_ERR_BAD_ITT;
1036         }
1037         return 0;
1038 }
1039 EXPORT_SYMBOL_GPL(iscsi_verify_itt);
1040
1041 /**
1042  * iscsi_itt_to_ctask - look up ctask by itt
1043  * @conn: iscsi connection
1044  * @itt: itt
1045  *
1046  * This should be used for cmd tasks.
1047  *
1048  * The session lock must be held.
1049  */
1050 struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *conn, itt_t itt)
1051 {
1052         struct iscsi_task *task;
1053
1054         if (iscsi_verify_itt(conn, itt))
1055                 return NULL;
1056
1057         task = iscsi_itt_to_task(conn, itt);
1058         if (!task || !task->sc)
1059                 return NULL;
1060
1061         if (task->sc->SCp.phase != conn->session->age) {
1062                 iscsi_session_printk(KERN_ERR, conn->session,
1063                                   "task's session age %d, expected %d\n",
1064                                   task->sc->SCp.phase, conn->session->age);
1065                 return NULL;
1066         }
1067
1068         return task;
1069 }
1070 EXPORT_SYMBOL_GPL(iscsi_itt_to_ctask);
1071
1072 void iscsi_session_failure(struct iscsi_session *session,
1073                            enum iscsi_err err)
1074 {
1075         struct iscsi_conn *conn;
1076         struct device *dev;
1077         unsigned long flags;
1078
1079         spin_lock_irqsave(&session->lock, flags);
1080         conn = session->leadconn;
1081         if (session->state == ISCSI_STATE_TERMINATE || !conn) {
1082                 spin_unlock_irqrestore(&session->lock, flags);
1083                 return;
1084         }
1085
1086         dev = get_device(&conn->cls_conn->dev);
1087         spin_unlock_irqrestore(&session->lock, flags);
1088         if (!dev)
1089                 return;
1090         /*
1091          * if the host is being removed bypass the connection
1092          * recovery initialization because we are going to kill
1093          * the session.
1094          */
1095         if (err == ISCSI_ERR_INVALID_HOST)
1096                 iscsi_conn_error_event(conn->cls_conn, err);
1097         else
1098                 iscsi_conn_failure(conn, err);
1099         put_device(dev);
1100 }
1101 EXPORT_SYMBOL_GPL(iscsi_session_failure);
1102
1103 void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err)
1104 {
1105         struct iscsi_session *session = conn->session;
1106         unsigned long flags;
1107
1108         spin_lock_irqsave(&session->lock, flags);
1109         if (session->state == ISCSI_STATE_FAILED) {
1110                 spin_unlock_irqrestore(&session->lock, flags);
1111                 return;
1112         }
1113
1114         if (conn->stop_stage == 0)
1115                 session->state = ISCSI_STATE_FAILED;
1116         spin_unlock_irqrestore(&session->lock, flags);
1117
1118         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1119         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
1120         iscsi_conn_error_event(conn->cls_conn, err);
1121 }
1122 EXPORT_SYMBOL_GPL(iscsi_conn_failure);
1123
1124 static int iscsi_check_cmdsn_window_closed(struct iscsi_conn *conn)
1125 {
1126         struct iscsi_session *session = conn->session;
1127
1128         /*
1129          * Check for iSCSI window and take care of CmdSN wrap-around
1130          */
1131         if (!iscsi_sna_lte(session->queued_cmdsn, session->max_cmdsn)) {
1132                 ISCSI_DBG_SESSION(session, "iSCSI CmdSN closed. ExpCmdSn "
1133                                   "%u MaxCmdSN %u CmdSN %u/%u\n",
1134                                   session->exp_cmdsn, session->max_cmdsn,
1135                                   session->cmdsn, session->queued_cmdsn);
1136                 return -ENOSPC;
1137         }
1138         return 0;
1139 }
1140
1141 static int iscsi_xmit_task(struct iscsi_conn *conn)
1142 {
1143         struct iscsi_task *task = conn->task;
1144         int rc;
1145
1146         __iscsi_get_task(task);
1147         spin_unlock_bh(&conn->session->lock);
1148         rc = conn->session->tt->xmit_task(task);
1149         spin_lock_bh(&conn->session->lock);
1150         __iscsi_put_task(task);
1151         if (!rc)
1152                 /* done with this task */
1153                 conn->task = NULL;
1154         return rc;
1155 }
1156
1157 /**
1158  * iscsi_requeue_task - requeue task to run from session workqueue
1159  * @task: task to requeue
1160  *
1161  * LLDs that need to run a task from the session workqueue should call
1162  * this. The session lock must be held. This should only be called
1163  * by software drivers.
1164  */
1165 void iscsi_requeue_task(struct iscsi_task *task)
1166 {
1167         struct iscsi_conn *conn = task->conn;
1168
1169         list_move_tail(&task->running, &conn->requeue);
1170         iscsi_conn_queue_work(conn);
1171 }
1172 EXPORT_SYMBOL_GPL(iscsi_requeue_task);
1173
1174 /**
1175  * iscsi_data_xmit - xmit any command into the scheduled connection
1176  * @conn: iscsi connection
1177  *
1178  * Notes:
1179  *      The function can return -EAGAIN in which case the caller must
1180  *      re-schedule it again later or recover. '0' return code means
1181  *      successful xmit.
1182  **/
1183 static int iscsi_data_xmit(struct iscsi_conn *conn)
1184 {
1185         int rc = 0;
1186
1187         spin_lock_bh(&conn->session->lock);
1188         if (unlikely(conn->suspend_tx)) {
1189                 ISCSI_DBG_SESSION(conn->session, "Tx suspended!\n");
1190                 spin_unlock_bh(&conn->session->lock);
1191                 return -ENODATA;
1192         }
1193
1194         if (conn->task) {
1195                 rc = iscsi_xmit_task(conn);
1196                 if (rc)
1197                         goto again;
1198         }
1199
1200         /*
1201          * process mgmt pdus like nops before commands since we should
1202          * only have one nop-out as a ping from us and targets should not
1203          * overflow us with nop-ins
1204          */
1205 check_mgmt:
1206         while (!list_empty(&conn->mgmtqueue)) {
1207                 conn->task = list_entry(conn->mgmtqueue.next,
1208                                          struct iscsi_task, running);
1209                 if (iscsi_prep_mgmt_task(conn, conn->task)) {
1210                         __iscsi_put_task(conn->task);
1211                         conn->task = NULL;
1212                         continue;
1213                 }
1214                 rc = iscsi_xmit_task(conn);
1215                 if (rc)
1216                         goto again;
1217         }
1218
1219         /* process pending command queue */
1220         while (!list_empty(&conn->xmitqueue)) {
1221                 if (conn->tmf_state == TMF_QUEUED)
1222                         break;
1223
1224                 conn->task = list_entry(conn->xmitqueue.next,
1225                                          struct iscsi_task, running);
1226                 if (conn->session->state == ISCSI_STATE_LOGGING_OUT) {
1227                         fail_command(conn, conn->task, DID_IMM_RETRY << 16);
1228                         continue;
1229                 }
1230                 rc = iscsi_prep_scsi_cmd_pdu(conn->task);
1231                 if (rc) {
1232                         if (rc == -ENOMEM) {
1233                                 conn->task = NULL;
1234                                 goto again;
1235                         } else
1236                                 fail_command(conn, conn->task, DID_ABORT << 16);
1237                         continue;
1238                 }
1239                 rc = iscsi_xmit_task(conn);
1240                 if (rc)
1241                         goto again;
1242                 /*
1243                  * we could continuously get new task requests so
1244                  * we need to check the mgmt queue for nops that need to
1245                  * be sent to aviod starvation
1246                  */
1247                 if (!list_empty(&conn->mgmtqueue))
1248                         goto check_mgmt;
1249         }
1250
1251         while (!list_empty(&conn->requeue)) {
1252                 if (conn->session->fast_abort && conn->tmf_state != TMF_INITIAL)
1253                         break;
1254
1255                 /*
1256                  * we always do fastlogout - conn stop code will clean up.
1257                  */
1258                 if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
1259                         break;
1260
1261                 conn->task = list_entry(conn->requeue.next,
1262                                          struct iscsi_task, running);
1263                 conn->task->state = ISCSI_TASK_RUNNING;
1264                 list_move_tail(conn->requeue.next, &conn->run_list);
1265                 rc = iscsi_xmit_task(conn);
1266                 if (rc)
1267                         goto again;
1268                 if (!list_empty(&conn->mgmtqueue))
1269                         goto check_mgmt;
1270         }
1271         spin_unlock_bh(&conn->session->lock);
1272         return -ENODATA;
1273
1274 again:
1275         if (unlikely(conn->suspend_tx))
1276                 rc = -ENODATA;
1277         spin_unlock_bh(&conn->session->lock);
1278         return rc;
1279 }
1280
1281 static void iscsi_xmitworker(struct work_struct *work)
1282 {
1283         struct iscsi_conn *conn =
1284                 container_of(work, struct iscsi_conn, xmitwork);
1285         int rc;
1286         /*
1287          * serialize Xmit worker on a per-connection basis.
1288          */
1289         do {
1290                 rc = iscsi_data_xmit(conn);
1291         } while (rc >= 0 || rc == -EAGAIN);
1292 }
1293
1294 static inline struct iscsi_task *iscsi_alloc_task(struct iscsi_conn *conn,
1295                                                   struct scsi_cmnd *sc)
1296 {
1297         struct iscsi_task *task;
1298
1299         if (!__kfifo_get(conn->session->cmdpool.queue,
1300                          (void *) &task, sizeof(void *)))
1301                 return NULL;
1302
1303         sc->SCp.phase = conn->session->age;
1304         sc->SCp.ptr = (char *) task;
1305
1306         atomic_set(&task->refcount, 1);
1307         task->state = ISCSI_TASK_PENDING;
1308         task->conn = conn;
1309         task->sc = sc;
1310         INIT_LIST_HEAD(&task->running);
1311         return task;
1312 }
1313
1314 enum {
1315         FAILURE_BAD_HOST = 1,
1316         FAILURE_SESSION_FAILED,
1317         FAILURE_SESSION_FREED,
1318         FAILURE_WINDOW_CLOSED,
1319         FAILURE_OOM,
1320         FAILURE_SESSION_TERMINATE,
1321         FAILURE_SESSION_IN_RECOVERY,
1322         FAILURE_SESSION_RECOVERY_TIMEOUT,
1323         FAILURE_SESSION_LOGGING_OUT,
1324         FAILURE_SESSION_NOT_READY,
1325 };
1326
1327 int iscsi_queuecommand(struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *))
1328 {
1329         struct iscsi_cls_session *cls_session;
1330         struct Scsi_Host *host;
1331         int reason = 0;
1332         struct iscsi_session *session;
1333         struct iscsi_conn *conn;
1334         struct iscsi_task *task = NULL;
1335
1336         sc->scsi_done = done;
1337         sc->result = 0;
1338         sc->SCp.ptr = NULL;
1339
1340         host = sc->device->host;
1341         spin_unlock(host->host_lock);
1342
1343         cls_session = starget_to_session(scsi_target(sc->device));
1344         session = cls_session->dd_data;
1345         spin_lock(&session->lock);
1346
1347         reason = iscsi_session_chkready(cls_session);
1348         if (reason) {
1349                 sc->result = reason;
1350                 goto fault;
1351         }
1352
1353         /*
1354          * ISCSI_STATE_FAILED is a temp. state. The recovery
1355          * code will decide what is best to do with command queued
1356          * during this time
1357          */
1358         if (session->state != ISCSI_STATE_LOGGED_IN &&
1359             session->state != ISCSI_STATE_FAILED) {
1360                 /*
1361                  * to handle the race between when we set the recovery state
1362                  * and block the session we requeue here (commands could
1363                  * be entering our queuecommand while a block is starting
1364                  * up because the block code is not locked)
1365                  */
1366                 switch (session->state) {
1367                 case ISCSI_STATE_IN_RECOVERY:
1368                         reason = FAILURE_SESSION_IN_RECOVERY;
1369                         goto reject;
1370                 case ISCSI_STATE_LOGGING_OUT:
1371                         reason = FAILURE_SESSION_LOGGING_OUT;
1372                         goto reject;
1373                 case ISCSI_STATE_RECOVERY_FAILED:
1374                         reason = FAILURE_SESSION_RECOVERY_TIMEOUT;
1375                         sc->result = DID_TRANSPORT_FAILFAST << 16;
1376                         break;
1377                 case ISCSI_STATE_TERMINATE:
1378                         reason = FAILURE_SESSION_TERMINATE;
1379                         sc->result = DID_NO_CONNECT << 16;
1380                         break;
1381                 default:
1382                         reason = FAILURE_SESSION_FREED;
1383                         sc->result = DID_NO_CONNECT << 16;
1384                 }
1385                 goto fault;
1386         }
1387
1388         conn = session->leadconn;
1389         if (!conn) {
1390                 reason = FAILURE_SESSION_FREED;
1391                 sc->result = DID_NO_CONNECT << 16;
1392                 goto fault;
1393         }
1394
1395         if (iscsi_check_cmdsn_window_closed(conn)) {
1396                 reason = FAILURE_WINDOW_CLOSED;
1397                 goto reject;
1398         }
1399
1400         task = iscsi_alloc_task(conn, sc);
1401         if (!task) {
1402                 reason = FAILURE_OOM;
1403                 goto reject;
1404         }
1405         list_add_tail(&task->running, &conn->xmitqueue);
1406
1407         if (session->tt->caps & CAP_DATA_PATH_OFFLOAD) {
1408                 reason = iscsi_prep_scsi_cmd_pdu(task);
1409                 if (reason) {
1410                         if (reason == -ENOMEM) {
1411                                 reason = FAILURE_OOM;
1412                                 goto prepd_reject;
1413                         } else {
1414                                 sc->result = DID_ABORT << 16;
1415                                 goto prepd_fault;
1416                         }
1417                 }
1418                 if (session->tt->xmit_task(task)) {
1419                         reason = FAILURE_SESSION_NOT_READY;
1420                         goto prepd_reject;
1421                 }
1422         } else
1423                 iscsi_conn_queue_work(conn);
1424
1425         session->queued_cmdsn++;
1426         spin_unlock(&session->lock);
1427         spin_lock(host->host_lock);
1428         return 0;
1429
1430 prepd_reject:
1431         sc->scsi_done = NULL;
1432         iscsi_complete_command(task);
1433 reject:
1434         spin_unlock(&session->lock);
1435         ISCSI_DBG_SESSION(session, "cmd 0x%x rejected (%d)\n",
1436                           sc->cmnd[0], reason);
1437         spin_lock(host->host_lock);
1438         return SCSI_MLQUEUE_TARGET_BUSY;
1439
1440 prepd_fault:
1441         sc->scsi_done = NULL;
1442         iscsi_complete_command(task);
1443 fault:
1444         spin_unlock(&session->lock);
1445         ISCSI_DBG_SESSION(session, "iscsi: cmd 0x%x is not queued (%d)\n",
1446                           sc->cmnd[0], reason);
1447         if (!scsi_bidi_cmnd(sc))
1448                 scsi_set_resid(sc, scsi_bufflen(sc));
1449         else {
1450                 scsi_out(sc)->resid = scsi_out(sc)->length;
1451                 scsi_in(sc)->resid = scsi_in(sc)->length;
1452         }
1453         done(sc);
1454         spin_lock(host->host_lock);
1455         return 0;
1456 }
1457 EXPORT_SYMBOL_GPL(iscsi_queuecommand);
1458
1459 int iscsi_change_queue_depth(struct scsi_device *sdev, int depth)
1460 {
1461         scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
1462         return sdev->queue_depth;
1463 }
1464 EXPORT_SYMBOL_GPL(iscsi_change_queue_depth);
1465
1466 void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
1467 {
1468         struct iscsi_session *session = cls_session->dd_data;
1469
1470         spin_lock_bh(&session->lock);
1471         if (session->state != ISCSI_STATE_LOGGED_IN) {
1472                 session->state = ISCSI_STATE_RECOVERY_FAILED;
1473                 if (session->leadconn)
1474                         wake_up(&session->leadconn->ehwait);
1475         }
1476         spin_unlock_bh(&session->lock);
1477 }
1478 EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
1479
1480 int iscsi_eh_target_reset(struct scsi_cmnd *sc)
1481 {
1482         struct iscsi_cls_session *cls_session;
1483         struct iscsi_session *session;
1484         struct iscsi_conn *conn;
1485
1486         cls_session = starget_to_session(scsi_target(sc->device));
1487         session = cls_session->dd_data;
1488         conn = session->leadconn;
1489
1490         mutex_lock(&session->eh_mutex);
1491         spin_lock_bh(&session->lock);
1492         if (session->state == ISCSI_STATE_TERMINATE) {
1493 failed:
1494                 iscsi_session_printk(KERN_INFO, session,
1495                                      "failing target reset: Could not log "
1496                                      "back into target [age %d]\n",
1497                                      session->age);
1498                 spin_unlock_bh(&session->lock);
1499                 mutex_unlock(&session->eh_mutex);
1500                 return FAILED;
1501         }
1502
1503         spin_unlock_bh(&session->lock);
1504         mutex_unlock(&session->eh_mutex);
1505         /*
1506          * we drop the lock here but the leadconn cannot be destoyed while
1507          * we are in the scsi eh
1508          */
1509         iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1510
1511         ISCSI_DBG_SESSION(session, "wait for relogin\n");
1512         wait_event_interruptible(conn->ehwait,
1513                                  session->state == ISCSI_STATE_TERMINATE ||
1514                                  session->state == ISCSI_STATE_LOGGED_IN ||
1515                                  session->state == ISCSI_STATE_RECOVERY_FAILED);
1516         if (signal_pending(current))
1517                 flush_signals(current);
1518
1519         mutex_lock(&session->eh_mutex);
1520         spin_lock_bh(&session->lock);
1521         if (session->state == ISCSI_STATE_LOGGED_IN)
1522                 iscsi_session_printk(KERN_INFO, session,
1523                                      "target reset succeeded\n");
1524         else
1525                 goto failed;
1526         spin_unlock_bh(&session->lock);
1527         mutex_unlock(&session->eh_mutex);
1528         return SUCCESS;
1529 }
1530 EXPORT_SYMBOL_GPL(iscsi_eh_target_reset);
1531
1532 static void iscsi_tmf_timedout(unsigned long data)
1533 {
1534         struct iscsi_conn *conn = (struct iscsi_conn *)data;
1535         struct iscsi_session *session = conn->session;
1536
1537         spin_lock(&session->lock);
1538         if (conn->tmf_state == TMF_QUEUED) {
1539                 conn->tmf_state = TMF_TIMEDOUT;
1540                 ISCSI_DBG_SESSION(session, "tmf timedout\n");
1541                 /* unblock eh_abort() */
1542                 wake_up(&conn->ehwait);
1543         }
1544         spin_unlock(&session->lock);
1545 }
1546
1547 static int iscsi_exec_task_mgmt_fn(struct iscsi_conn *conn,
1548                                    struct iscsi_tm *hdr, int age,
1549                                    int timeout)
1550 {
1551         struct iscsi_session *session = conn->session;
1552         struct iscsi_task *task;
1553
1554         task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)hdr,
1555                                       NULL, 0);
1556         if (!task) {
1557                 spin_unlock_bh(&session->lock);
1558                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1559                 spin_lock_bh(&session->lock);
1560                 ISCSI_DBG_SESSION(session, "tmf exec failure\n");
1561                 return -EPERM;
1562         }
1563         conn->tmfcmd_pdus_cnt++;
1564         conn->tmf_timer.expires = timeout * HZ + jiffies;
1565         conn->tmf_timer.function = iscsi_tmf_timedout;
1566         conn->tmf_timer.data = (unsigned long)conn;
1567         add_timer(&conn->tmf_timer);
1568         ISCSI_DBG_SESSION(session, "tmf set timeout\n");
1569
1570         spin_unlock_bh(&session->lock);
1571         mutex_unlock(&session->eh_mutex);
1572
1573         /*
1574          * block eh thread until:
1575          *
1576          * 1) tmf response
1577          * 2) tmf timeout
1578          * 3) session is terminated or restarted or userspace has
1579          * given up on recovery
1580          */
1581         wait_event_interruptible(conn->ehwait, age != session->age ||
1582                                  session->state != ISCSI_STATE_LOGGED_IN ||
1583                                  conn->tmf_state != TMF_QUEUED);
1584         if (signal_pending(current))
1585                 flush_signals(current);
1586         del_timer_sync(&conn->tmf_timer);
1587
1588         mutex_lock(&session->eh_mutex);
1589         spin_lock_bh(&session->lock);
1590         /* if the session drops it will clean up the task */
1591         if (age != session->age ||
1592             session->state != ISCSI_STATE_LOGGED_IN)
1593                 return -ENOTCONN;
1594         return 0;
1595 }
1596
1597 /*
1598  * Fail commands. session lock held and recv side suspended and xmit
1599  * thread flushed
1600  */
1601 static void fail_all_commands(struct iscsi_conn *conn, unsigned lun,
1602                               int error)
1603 {
1604         struct iscsi_task *task, *tmp;
1605
1606         if (conn->task) {
1607                 if (lun == -1 ||
1608                     (conn->task->sc && conn->task->sc->device->lun == lun))
1609                         conn->task = NULL;
1610         }
1611
1612         /* flush pending */
1613         list_for_each_entry_safe(task, tmp, &conn->xmitqueue, running) {
1614                 if (lun == task->sc->device->lun || lun == -1) {
1615                         ISCSI_DBG_SESSION(conn->session,
1616                                           "failing pending sc %p itt 0x%x\n",
1617                                           task->sc, task->itt);
1618                         fail_command(conn, task, error << 16);
1619                 }
1620         }
1621
1622         list_for_each_entry_safe(task, tmp, &conn->requeue, running) {
1623                 if (lun == task->sc->device->lun || lun == -1) {
1624                         ISCSI_DBG_SESSION(conn->session,
1625                                           "failing requeued sc %p itt 0x%x\n",
1626                                           task->sc, task->itt);
1627                         fail_command(conn, task, error << 16);
1628                 }
1629         }
1630
1631         /* fail all other running */
1632         list_for_each_entry_safe(task, tmp, &conn->run_list, running) {
1633                 if (lun == task->sc->device->lun || lun == -1) {
1634                         ISCSI_DBG_SESSION(conn->session,
1635                                          "failing in progress sc %p itt 0x%x\n",
1636                                          task->sc, task->itt);
1637                         fail_command(conn, task, error << 16);
1638                 }
1639         }
1640 }
1641
1642 void iscsi_suspend_tx(struct iscsi_conn *conn)
1643 {
1644         struct Scsi_Host *shost = conn->session->host;
1645         struct iscsi_host *ihost = shost_priv(shost);
1646
1647         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1648         if (!(conn->session->tt->caps & CAP_DATA_PATH_OFFLOAD))
1649                 flush_workqueue(ihost->workq);
1650 }
1651 EXPORT_SYMBOL_GPL(iscsi_suspend_tx);
1652
1653 static void iscsi_start_tx(struct iscsi_conn *conn)
1654 {
1655         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
1656         if (!(conn->session->tt->caps & CAP_DATA_PATH_OFFLOAD))
1657                 iscsi_conn_queue_work(conn);
1658 }
1659
1660 static enum blk_eh_timer_return iscsi_eh_cmd_timed_out(struct scsi_cmnd *scmd)
1661 {
1662         struct iscsi_cls_session *cls_session;
1663         struct iscsi_session *session;
1664         struct iscsi_conn *conn;
1665         enum blk_eh_timer_return rc = BLK_EH_NOT_HANDLED;
1666
1667         cls_session = starget_to_session(scsi_target(scmd->device));
1668         session = cls_session->dd_data;
1669
1670         ISCSI_DBG_SESSION(session, "scsi cmd %p timedout\n", scmd);
1671
1672         spin_lock(&session->lock);
1673         if (session->state != ISCSI_STATE_LOGGED_IN) {
1674                 /*
1675                  * We are probably in the middle of iscsi recovery so let
1676                  * that complete and handle the error.
1677                  */
1678                 rc = BLK_EH_RESET_TIMER;
1679                 goto done;
1680         }
1681
1682         conn = session->leadconn;
1683         if (!conn) {
1684                 /* In the middle of shuting down */
1685                 rc = BLK_EH_RESET_TIMER;
1686                 goto done;
1687         }
1688
1689         if (!conn->recv_timeout && !conn->ping_timeout)
1690                 goto done;
1691         /*
1692          * if the ping timedout then we are in the middle of cleaning up
1693          * and can let the iscsi eh handle it
1694          */
1695         if (time_before_eq(conn->last_recv + (conn->recv_timeout * HZ) +
1696                             (conn->ping_timeout * HZ), jiffies))
1697                 rc = BLK_EH_RESET_TIMER;
1698         /*
1699          * if we are about to check the transport then give the command
1700          * more time
1701          */
1702         if (time_before_eq(conn->last_recv + (conn->recv_timeout * HZ),
1703                            jiffies))
1704                 rc = BLK_EH_RESET_TIMER;
1705         /* if in the middle of checking the transport then give us more time */
1706         if (conn->ping_task)
1707                 rc = BLK_EH_RESET_TIMER;
1708 done:
1709         spin_unlock(&session->lock);
1710         ISCSI_DBG_SESSION(session, "return %s\n", rc == BLK_EH_RESET_TIMER ?
1711                           "timer reset" : "nh");
1712         return rc;
1713 }
1714
1715 static void iscsi_check_transport_timeouts(unsigned long data)
1716 {
1717         struct iscsi_conn *conn = (struct iscsi_conn *)data;
1718         struct iscsi_session *session = conn->session;
1719         unsigned long recv_timeout, next_timeout = 0, last_recv;
1720
1721         spin_lock(&session->lock);
1722         if (session->state != ISCSI_STATE_LOGGED_IN)
1723                 goto done;
1724
1725         recv_timeout = conn->recv_timeout;
1726         if (!recv_timeout)
1727                 goto done;
1728
1729         recv_timeout *= HZ;
1730         last_recv = conn->last_recv;
1731         if (conn->ping_task &&
1732             time_before_eq(conn->last_ping + (conn->ping_timeout * HZ),
1733                            jiffies)) {
1734                 iscsi_conn_printk(KERN_ERR, conn, "ping timeout of %d secs "
1735                                   "expired, last rx %lu, last ping %lu, "
1736                                   "now %lu\n", conn->ping_timeout, last_recv,
1737                                   conn->last_ping, jiffies);
1738                 spin_unlock(&session->lock);
1739                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1740                 return;
1741         }
1742
1743         if (time_before_eq(last_recv + recv_timeout, jiffies)) {
1744                 /* send a ping to try to provoke some traffic */
1745                 ISCSI_DBG_CONN(conn, "Sending nopout as ping\n");
1746                 iscsi_send_nopout(conn, NULL);
1747                 next_timeout = conn->last_ping + (conn->ping_timeout * HZ);
1748         } else
1749                 next_timeout = last_recv + recv_timeout;
1750
1751         ISCSI_DBG_CONN(conn, "Setting next tmo %lu\n", next_timeout);
1752         mod_timer(&conn->transport_timer, next_timeout);
1753 done:
1754         spin_unlock(&session->lock);
1755 }
1756
1757 static void iscsi_prep_abort_task_pdu(struct iscsi_task *task,
1758                                       struct iscsi_tm *hdr)
1759 {
1760         memset(hdr, 0, sizeof(*hdr));
1761         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
1762         hdr->flags = ISCSI_TM_FUNC_ABORT_TASK & ISCSI_FLAG_TM_FUNC_MASK;
1763         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
1764         memcpy(hdr->lun, task->lun, sizeof(hdr->lun));
1765         hdr->rtt = task->hdr_itt;
1766         hdr->refcmdsn = task->cmdsn;
1767 }
1768
1769 int iscsi_eh_abort(struct scsi_cmnd *sc)
1770 {
1771         struct iscsi_cls_session *cls_session;
1772         struct iscsi_session *session;
1773         struct iscsi_conn *conn;
1774         struct iscsi_task *task;
1775         struct iscsi_tm *hdr;
1776         int rc, age;
1777
1778         cls_session = starget_to_session(scsi_target(sc->device));
1779         session = cls_session->dd_data;
1780
1781         mutex_lock(&session->eh_mutex);
1782         spin_lock_bh(&session->lock);
1783         /*
1784          * if session was ISCSI_STATE_IN_RECOVERY then we may not have
1785          * got the command.
1786          */
1787         if (!sc->SCp.ptr) {
1788                 ISCSI_DBG_SESSION(session, "sc never reached iscsi layer or "
1789                                   "it completed.\n");
1790                 spin_unlock_bh(&session->lock);
1791                 mutex_unlock(&session->eh_mutex);
1792                 return SUCCESS;
1793         }
1794
1795         /*
1796          * If we are not logged in or we have started a new session
1797          * then let the host reset code handle this
1798          */
1799         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN ||
1800             sc->SCp.phase != session->age) {
1801                 spin_unlock_bh(&session->lock);
1802                 mutex_unlock(&session->eh_mutex);
1803                 return FAILED;
1804         }
1805
1806         conn = session->leadconn;
1807         conn->eh_abort_cnt++;
1808         age = session->age;
1809
1810         task = (struct iscsi_task *)sc->SCp.ptr;
1811         ISCSI_DBG_SESSION(session, "aborting [sc %p itt 0x%x]\n",
1812                           sc, task->itt);
1813
1814         /* task completed before time out */
1815         if (!task->sc) {
1816                 ISCSI_DBG_SESSION(session, "sc completed while abort in "
1817                                   "progress\n");
1818                 goto success;
1819         }
1820
1821         if (task->state == ISCSI_TASK_PENDING) {
1822                 fail_command(conn, task, DID_ABORT << 16);
1823                 goto success;
1824         }
1825
1826         /* only have one tmf outstanding at a time */
1827         if (conn->tmf_state != TMF_INITIAL)
1828                 goto failed;
1829         conn->tmf_state = TMF_QUEUED;
1830
1831         hdr = &conn->tmhdr;
1832         iscsi_prep_abort_task_pdu(task, hdr);
1833
1834         if (iscsi_exec_task_mgmt_fn(conn, hdr, age, session->abort_timeout)) {
1835                 rc = FAILED;
1836                 goto failed;
1837         }
1838
1839         switch (conn->tmf_state) {
1840         case TMF_SUCCESS:
1841                 spin_unlock_bh(&session->lock);
1842                 /*
1843                  * stop tx side incase the target had sent a abort rsp but
1844                  * the initiator was still writing out data.
1845                  */
1846                 iscsi_suspend_tx(conn);
1847                 /*
1848                  * we do not stop the recv side because targets have been
1849                  * good and have never sent us a successful tmf response
1850                  * then sent more data for the cmd.
1851                  */
1852                 spin_lock(&session->lock);
1853                 fail_command(conn, task, DID_ABORT << 16);
1854                 conn->tmf_state = TMF_INITIAL;
1855                 spin_unlock(&session->lock);
1856                 iscsi_start_tx(conn);
1857                 goto success_unlocked;
1858         case TMF_TIMEDOUT:
1859                 spin_unlock_bh(&session->lock);
1860                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1861                 goto failed_unlocked;
1862         case TMF_NOT_FOUND:
1863                 if (!sc->SCp.ptr) {
1864                         conn->tmf_state = TMF_INITIAL;
1865                         /* task completed before tmf abort response */
1866                         ISCSI_DBG_SESSION(session, "sc completed while abort "
1867                                           "in progress\n");
1868                         goto success;
1869                 }
1870                 /* fall through */
1871         default:
1872                 conn->tmf_state = TMF_INITIAL;
1873                 goto failed;
1874         }
1875
1876 success:
1877         spin_unlock_bh(&session->lock);
1878 success_unlocked:
1879         ISCSI_DBG_SESSION(session, "abort success [sc %p itt 0x%x]\n",
1880                           sc, task->itt);
1881         mutex_unlock(&session->eh_mutex);
1882         return SUCCESS;
1883
1884 failed:
1885         spin_unlock_bh(&session->lock);
1886 failed_unlocked:
1887         ISCSI_DBG_SESSION(session, "abort failed [sc %p itt 0x%x]\n", sc,
1888                           task ? task->itt : 0);
1889         mutex_unlock(&session->eh_mutex);
1890         return FAILED;
1891 }
1892 EXPORT_SYMBOL_GPL(iscsi_eh_abort);
1893
1894 static void iscsi_prep_lun_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
1895 {
1896         memset(hdr, 0, sizeof(*hdr));
1897         hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
1898         hdr->flags = ISCSI_TM_FUNC_LOGICAL_UNIT_RESET & ISCSI_FLAG_TM_FUNC_MASK;
1899         hdr->flags |= ISCSI_FLAG_CMD_FINAL;
1900         int_to_scsilun(sc->device->lun, (struct scsi_lun *)hdr->lun);
1901         hdr->rtt = RESERVED_ITT;
1902 }
1903
1904 int iscsi_eh_device_reset(struct scsi_cmnd *sc)
1905 {
1906         struct iscsi_cls_session *cls_session;
1907         struct iscsi_session *session;
1908         struct iscsi_conn *conn;
1909         struct iscsi_tm *hdr;
1910         int rc = FAILED;
1911
1912         cls_session = starget_to_session(scsi_target(sc->device));
1913         session = cls_session->dd_data;
1914
1915         ISCSI_DBG_SESSION(session, "LU Reset [sc %p lun %u]\n",
1916                           sc, sc->device->lun);
1917
1918         mutex_lock(&session->eh_mutex);
1919         spin_lock_bh(&session->lock);
1920         /*
1921          * Just check if we are not logged in. We cannot check for
1922          * the phase because the reset could come from a ioctl.
1923          */
1924         if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
1925                 goto unlock;
1926         conn = session->leadconn;
1927
1928         /* only have one tmf outstanding at a time */
1929         if (conn->tmf_state != TMF_INITIAL)
1930                 goto unlock;
1931         conn->tmf_state = TMF_QUEUED;
1932
1933         hdr = &conn->tmhdr;
1934         iscsi_prep_lun_reset_pdu(sc, hdr);
1935
1936         if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
1937                                     session->lu_reset_timeout)) {
1938                 rc = FAILED;
1939                 goto unlock;
1940         }
1941
1942         switch (conn->tmf_state) {
1943         case TMF_SUCCESS:
1944                 break;
1945         case TMF_TIMEDOUT:
1946                 spin_unlock_bh(&session->lock);
1947                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
1948                 goto done;
1949         default:
1950                 conn->tmf_state = TMF_INITIAL;
1951                 goto unlock;
1952         }
1953
1954         rc = SUCCESS;
1955         spin_unlock_bh(&session->lock);
1956
1957         iscsi_suspend_tx(conn);
1958
1959         spin_lock_bh(&session->lock);
1960         fail_all_commands(conn, sc->device->lun, DID_ERROR);
1961         conn->tmf_state = TMF_INITIAL;
1962         spin_unlock_bh(&session->lock);
1963
1964         iscsi_start_tx(conn);
1965         goto done;
1966
1967 unlock:
1968         spin_unlock_bh(&session->lock);
1969 done:
1970         ISCSI_DBG_SESSION(session, "dev reset result = %s\n",
1971                          rc == SUCCESS ? "SUCCESS" : "FAILED");
1972         mutex_unlock(&session->eh_mutex);
1973         return rc;
1974 }
1975 EXPORT_SYMBOL_GPL(iscsi_eh_device_reset);
1976
1977 /*
1978  * Pre-allocate a pool of @max items of @item_size. By default, the pool
1979  * should be accessed via kfifo_{get,put} on q->queue.
1980  * Optionally, the caller can obtain the array of object pointers
1981  * by passing in a non-NULL @items pointer
1982  */
1983 int
1984 iscsi_pool_init(struct iscsi_pool *q, int max, void ***items, int item_size)
1985 {
1986         int i, num_arrays = 1;
1987
1988         memset(q, 0, sizeof(*q));
1989
1990         q->max = max;
1991
1992         /* If the user passed an items pointer, he wants a copy of
1993          * the array. */
1994         if (items)
1995                 num_arrays++;
1996         q->pool = kzalloc(num_arrays * max * sizeof(void*), GFP_KERNEL);
1997         if (q->pool == NULL)
1998                 return -ENOMEM;
1999
2000         q->queue = kfifo_init((void*)q->pool, max * sizeof(void*),
2001                               GFP_KERNEL, NULL);
2002         if (q->queue == ERR_PTR(-ENOMEM))
2003                 goto enomem;
2004
2005         for (i = 0; i < max; i++) {
2006                 q->pool[i] = kzalloc(item_size, GFP_KERNEL);
2007                 if (q->pool[i] == NULL) {
2008                         q->max = i;
2009                         goto enomem;
2010                 }
2011                 __kfifo_put(q->queue, (void*)&q->pool[i], sizeof(void*));
2012         }
2013
2014         if (items) {
2015                 *items = q->pool + max;
2016                 memcpy(*items, q->pool, max * sizeof(void *));
2017         }
2018
2019         return 0;
2020
2021 enomem:
2022         iscsi_pool_free(q);
2023         return -ENOMEM;
2024 }
2025 EXPORT_SYMBOL_GPL(iscsi_pool_init);
2026
2027 void iscsi_pool_free(struct iscsi_pool *q)
2028 {
2029         int i;
2030
2031         for (i = 0; i < q->max; i++)
2032                 kfree(q->pool[i]);
2033         kfree(q->pool);
2034         kfree(q->queue);
2035 }
2036 EXPORT_SYMBOL_GPL(iscsi_pool_free);
2037
2038 /**
2039  * iscsi_host_add - add host to system
2040  * @shost: scsi host
2041  * @pdev: parent device
2042  *
2043  * This should be called by partial offload and software iscsi drivers
2044  * to add a host to the system.
2045  */
2046 int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev)
2047 {
2048         if (!shost->can_queue)
2049                 shost->can_queue = ISCSI_DEF_XMIT_CMDS_MAX;
2050
2051         if (!shost->cmd_per_lun)
2052                 shost->cmd_per_lun = ISCSI_DEF_CMD_PER_LUN;
2053
2054         if (!shost->transportt->eh_timed_out)
2055                 shost->transportt->eh_timed_out = iscsi_eh_cmd_timed_out;
2056         return scsi_add_host(shost, pdev);
2057 }
2058 EXPORT_SYMBOL_GPL(iscsi_host_add);
2059
2060 /**
2061  * iscsi_host_alloc - allocate a host and driver data
2062  * @sht: scsi host template
2063  * @dd_data_size: driver host data size
2064  * @xmit_can_sleep: bool indicating if LLD will queue IO from a work queue
2065  *
2066  * This should be called by partial offload and software iscsi drivers.
2067  * To access the driver specific memory use the iscsi_host_priv() macro.
2068  */
2069 struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
2070                                    int dd_data_size, bool xmit_can_sleep)
2071 {
2072         struct Scsi_Host *shost;
2073         struct iscsi_host *ihost;
2074
2075         shost = scsi_host_alloc(sht, sizeof(struct iscsi_host) + dd_data_size);
2076         if (!shost)
2077                 return NULL;
2078         ihost = shost_priv(shost);
2079
2080         if (xmit_can_sleep) {
2081                 snprintf(ihost->workq_name, sizeof(ihost->workq_name),
2082                         "iscsi_q_%d", shost->host_no);
2083                 ihost->workq = create_singlethread_workqueue(ihost->workq_name);
2084                 if (!ihost->workq)
2085                         goto free_host;
2086         }
2087
2088         spin_lock_init(&ihost->lock);
2089         ihost->state = ISCSI_HOST_SETUP;
2090         ihost->num_sessions = 0;
2091         init_waitqueue_head(&ihost->session_removal_wq);
2092         return shost;
2093
2094 free_host:
2095         scsi_host_put(shost);
2096         return NULL;
2097 }
2098 EXPORT_SYMBOL_GPL(iscsi_host_alloc);
2099
2100 static void iscsi_notify_host_removed(struct iscsi_cls_session *cls_session)
2101 {
2102         iscsi_session_failure(cls_session->dd_data, ISCSI_ERR_INVALID_HOST);
2103 }
2104
2105 /**
2106  * iscsi_host_remove - remove host and sessions
2107  * @shost: scsi host
2108  *
2109  * If there are any sessions left, this will initiate the removal and wait
2110  * for the completion.
2111  */
2112 void iscsi_host_remove(struct Scsi_Host *shost)
2113 {
2114         struct iscsi_host *ihost = shost_priv(shost);
2115         unsigned long flags;
2116
2117         spin_lock_irqsave(&ihost->lock, flags);
2118         ihost->state = ISCSI_HOST_REMOVED;
2119         spin_unlock_irqrestore(&ihost->lock, flags);
2120
2121         iscsi_host_for_each_session(shost, iscsi_notify_host_removed);
2122         wait_event_interruptible(ihost->session_removal_wq,
2123                                  ihost->num_sessions == 0);
2124         if (signal_pending(current))
2125                 flush_signals(current);
2126
2127         scsi_remove_host(shost);
2128         if (ihost->workq)
2129                 destroy_workqueue(ihost->workq);
2130 }
2131 EXPORT_SYMBOL_GPL(iscsi_host_remove);
2132
2133 void iscsi_host_free(struct Scsi_Host *shost)
2134 {
2135         struct iscsi_host *ihost = shost_priv(shost);
2136
2137         kfree(ihost->netdev);
2138         kfree(ihost->hwaddress);
2139         kfree(ihost->initiatorname);
2140         scsi_host_put(shost);
2141 }
2142 EXPORT_SYMBOL_GPL(iscsi_host_free);
2143
2144 static void iscsi_host_dec_session_cnt(struct Scsi_Host *shost)
2145 {
2146         struct iscsi_host *ihost = shost_priv(shost);
2147         unsigned long flags;
2148
2149         shost = scsi_host_get(shost);
2150         if (!shost) {
2151                 printk(KERN_ERR "Invalid state. Cannot notify host removal "
2152                       "of session teardown event because host already "
2153                       "removed.\n");
2154                 return;
2155         }
2156
2157         spin_lock_irqsave(&ihost->lock, flags);
2158         ihost->num_sessions--;
2159         if (ihost->num_sessions == 0)
2160                 wake_up(&ihost->session_removal_wq);
2161         spin_unlock_irqrestore(&ihost->lock, flags);
2162         scsi_host_put(shost);
2163 }
2164
2165 /**
2166  * iscsi_session_setup - create iscsi cls session and host and session
2167  * @iscsit: iscsi transport template
2168  * @shost: scsi host
2169  * @cmds_max: session can queue
2170  * @cmd_task_size: LLD task private data size
2171  * @initial_cmdsn: initial CmdSN
2172  *
2173  * This can be used by software iscsi_transports that allocate
2174  * a session per scsi host.
2175  *
2176  * Callers should set cmds_max to the largest total numer (mgmt + scsi) of
2177  * tasks they support. The iscsi layer reserves ISCSI_MGMT_CMDS_MAX tasks
2178  * for nop handling and login/logout requests.
2179  */
2180 struct iscsi_cls_session *
2181 iscsi_session_setup(struct iscsi_transport *iscsit, struct Scsi_Host *shost,
2182                     uint16_t cmds_max, int cmd_task_size,
2183                     uint32_t initial_cmdsn, unsigned int id)
2184 {
2185         struct iscsi_host *ihost = shost_priv(shost);
2186         struct iscsi_session *session;
2187         struct iscsi_cls_session *cls_session;
2188         int cmd_i, scsi_cmds, total_cmds = cmds_max;
2189         unsigned long flags;
2190
2191         spin_lock_irqsave(&ihost->lock, flags);
2192         if (ihost->state == ISCSI_HOST_REMOVED) {
2193                 spin_unlock_irqrestore(&ihost->lock, flags);
2194                 return NULL;
2195         }
2196         ihost->num_sessions++;
2197         spin_unlock_irqrestore(&ihost->lock, flags);
2198
2199         if (!total_cmds)
2200                 total_cmds = ISCSI_DEF_XMIT_CMDS_MAX;
2201         /*
2202          * The iscsi layer needs some tasks for nop handling and tmfs,
2203          * so the cmds_max must at least be greater than ISCSI_MGMT_CMDS_MAX
2204          * + 1 command for scsi IO.
2205          */
2206         if (total_cmds < ISCSI_TOTAL_CMDS_MIN) {
2207                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2208                        "must be a power of two that is at least %d.\n",
2209                        total_cmds, ISCSI_TOTAL_CMDS_MIN);
2210                 goto dec_session_count;
2211         }
2212
2213         if (total_cmds > ISCSI_TOTAL_CMDS_MAX) {
2214                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2215                        "must be a power of 2 less than or equal to %d.\n",
2216                        cmds_max, ISCSI_TOTAL_CMDS_MAX);
2217                 total_cmds = ISCSI_TOTAL_CMDS_MAX;
2218         }
2219
2220         if (!is_power_of_2(total_cmds)) {
2221                 printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
2222                        "must be a power of 2.\n", total_cmds);
2223                 total_cmds = rounddown_pow_of_two(total_cmds);
2224                 if (total_cmds < ISCSI_TOTAL_CMDS_MIN)
2225                         return NULL;
2226                 printk(KERN_INFO "iscsi: Rounding can_queue to %d.\n",
2227                        total_cmds);
2228         }
2229         scsi_cmds = total_cmds - ISCSI_MGMT_CMDS_MAX;
2230
2231         cls_session = iscsi_alloc_session(shost, iscsit,
2232                                           sizeof(struct iscsi_session));
2233         if (!cls_session)
2234                 goto dec_session_count;
2235         session = cls_session->dd_data;
2236         session->cls_session = cls_session;
2237         session->host = shost;
2238         session->state = ISCSI_STATE_FREE;
2239         session->fast_abort = 1;
2240         session->lu_reset_timeout = 15;
2241         session->abort_timeout = 10;
2242         session->scsi_cmds_max = scsi_cmds;
2243         session->cmds_max = total_cmds;
2244         session->queued_cmdsn = session->cmdsn = initial_cmdsn;
2245         session->exp_cmdsn = initial_cmdsn + 1;
2246         session->max_cmdsn = initial_cmdsn + 1;
2247         session->max_r2t = 1;
2248         session->tt = iscsit;
2249         mutex_init(&session->eh_mutex);
2250         spin_lock_init(&session->lock);
2251
2252         /* initialize SCSI PDU commands pool */
2253         if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
2254                             (void***)&session->cmds,
2255                             cmd_task_size + sizeof(struct iscsi_task)))
2256                 goto cmdpool_alloc_fail;
2257
2258         /* pre-format cmds pool with ITT */
2259         for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
2260                 struct iscsi_task *task = session->cmds[cmd_i];
2261
2262                 if (cmd_task_size)
2263                         task->dd_data = &task[1];
2264                 task->itt = cmd_i;
2265                 INIT_LIST_HEAD(&task->running);
2266         }
2267
2268         if (!try_module_get(iscsit->owner))
2269                 goto module_get_fail;
2270
2271         if (iscsi_add_session(cls_session, id))
2272                 goto cls_session_fail;
2273
2274         return cls_session;
2275
2276 cls_session_fail:
2277         module_put(iscsit->owner);
2278 module_get_fail:
2279         iscsi_pool_free(&session->cmdpool);
2280 cmdpool_alloc_fail:
2281         iscsi_free_session(cls_session);
2282 dec_session_count:
2283         iscsi_host_dec_session_cnt(shost);
2284         return NULL;
2285 }
2286 EXPORT_SYMBOL_GPL(iscsi_session_setup);
2287
2288 /**
2289  * iscsi_session_teardown - destroy session, host, and cls_session
2290  * @cls_session: iscsi session
2291  *
2292  * The driver must have called iscsi_remove_session before
2293  * calling this.
2294  */
2295 void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
2296 {
2297         struct iscsi_session *session = cls_session->dd_data;
2298         struct module *owner = cls_session->transport->owner;
2299         struct Scsi_Host *shost = session->host;
2300
2301         iscsi_pool_free(&session->cmdpool);
2302
2303         kfree(session->password);
2304         kfree(session->password_in);
2305         kfree(session->username);
2306         kfree(session->username_in);
2307         kfree(session->targetname);
2308         kfree(session->initiatorname);
2309         kfree(session->ifacename);
2310
2311         iscsi_destroy_session(cls_session);
2312         iscsi_host_dec_session_cnt(shost);
2313         module_put(owner);
2314 }
2315 EXPORT_SYMBOL_GPL(iscsi_session_teardown);
2316
2317 /**
2318  * iscsi_conn_setup - create iscsi_cls_conn and iscsi_conn
2319  * @cls_session: iscsi_cls_session
2320  * @dd_size: private driver data size
2321  * @conn_idx: cid
2322  */
2323 struct iscsi_cls_conn *
2324 iscsi_conn_setup(struct iscsi_cls_session *cls_session, int dd_size,
2325                  uint32_t conn_idx)
2326 {
2327         struct iscsi_session *session = cls_session->dd_data;
2328         struct iscsi_conn *conn;
2329         struct iscsi_cls_conn *cls_conn;
2330         char *data;
2331
2332         cls_conn = iscsi_create_conn(cls_session, sizeof(*conn) + dd_size,
2333                                      conn_idx);
2334         if (!cls_conn)
2335                 return NULL;
2336         conn = cls_conn->dd_data;
2337         memset(conn, 0, sizeof(*conn) + dd_size);
2338
2339         conn->dd_data = cls_conn->dd_data + sizeof(*conn);
2340         conn->session = session;
2341         conn->cls_conn = cls_conn;
2342         conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
2343         conn->id = conn_idx;
2344         conn->exp_statsn = 0;
2345         conn->tmf_state = TMF_INITIAL;
2346
2347         init_timer(&conn->transport_timer);
2348         conn->transport_timer.data = (unsigned long)conn;
2349         conn->transport_timer.function = iscsi_check_transport_timeouts;
2350
2351         INIT_LIST_HEAD(&conn->run_list);
2352         INIT_LIST_HEAD(&conn->mgmt_run_list);
2353         INIT_LIST_HEAD(&conn->mgmtqueue);
2354         INIT_LIST_HEAD(&conn->xmitqueue);
2355         INIT_LIST_HEAD(&conn->requeue);
2356         INIT_WORK(&conn->xmitwork, iscsi_xmitworker);
2357
2358         /* allocate login_task used for the login/text sequences */
2359         spin_lock_bh(&session->lock);
2360         if (!__kfifo_get(session->cmdpool.queue,
2361                          (void*)&conn->login_task,
2362                          sizeof(void*))) {
2363                 spin_unlock_bh(&session->lock);
2364                 goto login_task_alloc_fail;
2365         }
2366         spin_unlock_bh(&session->lock);
2367
2368         data = (char *) __get_free_pages(GFP_KERNEL,
2369                                          get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
2370         if (!data)
2371                 goto login_task_data_alloc_fail;
2372         conn->login_task->data = conn->data = data;
2373
2374         init_timer(&conn->tmf_timer);
2375         init_waitqueue_head(&conn->ehwait);
2376
2377         return cls_conn;
2378
2379 login_task_data_alloc_fail:
2380         __kfifo_put(session->cmdpool.queue, (void*)&conn->login_task,
2381                     sizeof(void*));
2382 login_task_alloc_fail:
2383         iscsi_destroy_conn(cls_conn);
2384         return NULL;
2385 }
2386 EXPORT_SYMBOL_GPL(iscsi_conn_setup);
2387
2388 /**
2389  * iscsi_conn_teardown - teardown iscsi connection
2390  * cls_conn: iscsi class connection
2391  *
2392  * TODO: we may need to make this into a two step process
2393  * like scsi-mls remove + put host
2394  */
2395 void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
2396 {
2397         struct iscsi_conn *conn = cls_conn->dd_data;
2398         struct iscsi_session *session = conn->session;
2399         unsigned long flags;
2400
2401         del_timer_sync(&conn->transport_timer);
2402
2403         spin_lock_bh(&session->lock);
2404         conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
2405         if (session->leadconn == conn) {
2406                 /*
2407                  * leading connection? then give up on recovery.
2408                  */
2409                 session->state = ISCSI_STATE_TERMINATE;
2410                 wake_up(&conn->ehwait);
2411         }
2412         spin_unlock_bh(&session->lock);
2413
2414         /*
2415          * Block until all in-progress commands for this connection
2416          * time out or fail.
2417          */
2418         for (;;) {
2419                 spin_lock_irqsave(session->host->host_lock, flags);
2420                 if (!session->host->host_busy) { /* OK for ERL == 0 */
2421                         spin_unlock_irqrestore(session->host->host_lock, flags);
2422                         break;
2423                 }
2424                 spin_unlock_irqrestore(session->host->host_lock, flags);
2425                 msleep_interruptible(500);
2426                 iscsi_conn_printk(KERN_INFO, conn, "iscsi conn_destroy(): "
2427                                   "host_busy %d host_failed %d\n",
2428                                   session->host->host_busy,
2429                                   session->host->host_failed);
2430                 /*
2431                  * force eh_abort() to unblock
2432                  */
2433                 wake_up(&conn->ehwait);
2434         }
2435
2436         /* flush queued up work because we free the connection below */
2437         iscsi_suspend_tx(conn);
2438
2439         spin_lock_bh(&session->lock);
2440         free_pages((unsigned long) conn->data,
2441                    get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
2442         kfree(conn->persistent_address);
2443         __kfifo_put(session->cmdpool.queue, (void*)&conn->login_task,
2444                     sizeof(void*));
2445         if (session->leadconn == conn)
2446                 session->leadconn = NULL;
2447         spin_unlock_bh(&session->lock);
2448
2449         iscsi_destroy_conn(cls_conn);
2450 }
2451 EXPORT_SYMBOL_GPL(iscsi_conn_teardown);
2452
2453 int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
2454 {
2455         struct iscsi_conn *conn = cls_conn->dd_data;
2456         struct iscsi_session *session = conn->session;
2457
2458         if (!session) {
2459                 iscsi_conn_printk(KERN_ERR, conn,
2460                                   "can't start unbound connection\n");
2461                 return -EPERM;
2462         }
2463
2464         if ((session->imm_data_en || !session->initial_r2t_en) &&
2465              session->first_burst > session->max_burst) {
2466                 iscsi_conn_printk(KERN_INFO, conn, "invalid burst lengths: "
2467                                   "first_burst %d max_burst %d\n",
2468                                   session->first_burst, session->max_burst);
2469                 return -EINVAL;
2470         }
2471
2472         if (conn->ping_timeout && !conn->recv_timeout) {
2473                 iscsi_conn_printk(KERN_ERR, conn, "invalid recv timeout of "
2474                                   "zero. Using 5 seconds\n.");
2475                 conn->recv_timeout = 5;
2476         }
2477
2478         if (conn->recv_timeout && !conn->ping_timeout) {
2479                 iscsi_conn_printk(KERN_ERR, conn, "invalid ping timeout of "
2480                                   "zero. Using 5 seconds.\n");
2481                 conn->ping_timeout = 5;
2482         }
2483
2484         spin_lock_bh(&session->lock);
2485         conn->c_stage = ISCSI_CONN_STARTED;
2486         session->state = ISCSI_STATE_LOGGED_IN;
2487         session->queued_cmdsn = session->cmdsn;
2488
2489         conn->last_recv = jiffies;
2490         conn->last_ping = jiffies;
2491         if (conn->recv_timeout && conn->ping_timeout)
2492                 mod_timer(&conn->transport_timer,
2493                           jiffies + (conn->recv_timeout * HZ));
2494
2495         switch(conn->stop_stage) {
2496         case STOP_CONN_RECOVER:
2497                 /*
2498                  * unblock eh_abort() if it is blocked. re-try all
2499                  * commands after successful recovery
2500                  */
2501                 conn->stop_stage = 0;
2502                 conn->tmf_state = TMF_INITIAL;
2503                 session->age++;
2504                 if (session->age == 16)
2505                         session->age = 0;
2506                 break;
2507         case STOP_CONN_TERM:
2508                 conn->stop_stage = 0;
2509                 break;
2510         default:
2511                 break;
2512         }
2513         spin_unlock_bh(&session->lock);
2514
2515         iscsi_unblock_session(session->cls_session);
2516         wake_up(&conn->ehwait);
2517         return 0;
2518 }
2519 EXPORT_SYMBOL_GPL(iscsi_conn_start);
2520
2521 static void
2522 flush_control_queues(struct iscsi_session *session, struct iscsi_conn *conn)
2523 {
2524         struct iscsi_task *task, *tmp;
2525
2526         /* handle pending */
2527         list_for_each_entry_safe(task, tmp, &conn->mgmtqueue, running) {
2528                 ISCSI_DBG_SESSION(session, "flushing pending mgmt task "
2529                                   "itt 0x%x\n", task->itt);
2530                 /* release ref from prep task */
2531                 __iscsi_put_task(task);
2532         }
2533
2534         /* handle running */
2535         list_for_each_entry_safe(task, tmp, &conn->mgmt_run_list, running) {
2536                 ISCSI_DBG_SESSION(session, "flushing running mgmt task "
2537                                   "itt 0x%x\n", task->itt);
2538                 /* release ref from prep task */
2539                 __iscsi_put_task(task);
2540         }
2541
2542         conn->task = NULL;
2543 }
2544
2545 static void iscsi_start_session_recovery(struct iscsi_session *session,
2546                                          struct iscsi_conn *conn, int flag)
2547 {
2548         int old_stop_stage;
2549
2550         del_timer_sync(&conn->transport_timer);
2551
2552         mutex_lock(&session->eh_mutex);
2553         spin_lock_bh(&session->lock);
2554         if (conn->stop_stage == STOP_CONN_TERM) {
2555                 spin_unlock_bh(&session->lock);
2556                 mutex_unlock(&session->eh_mutex);
2557                 return;
2558         }
2559
2560         /*
2561          * When this is called for the in_login state, we only want to clean
2562          * up the login task and connection. We do not need to block and set
2563          * the recovery state again
2564          */
2565         if (flag == STOP_CONN_TERM)
2566                 session->state = ISCSI_STATE_TERMINATE;
2567         else if (conn->stop_stage != STOP_CONN_RECOVER)
2568                 session->state = ISCSI_STATE_IN_RECOVERY;
2569
2570         old_stop_stage = conn->stop_stage;
2571         conn->stop_stage = flag;
2572         conn->c_stage = ISCSI_CONN_STOPPED;
2573         spin_unlock_bh(&session->lock);
2574
2575         iscsi_suspend_tx(conn);
2576         /*
2577          * for connection level recovery we should not calculate
2578          * header digest. conn->hdr_size used for optimization
2579          * in hdr_extract() and will be re-negotiated at
2580          * set_param() time.
2581          */
2582         if (flag == STOP_CONN_RECOVER) {
2583                 conn->hdrdgst_en = 0;
2584                 conn->datadgst_en = 0;
2585                 if (session->state == ISCSI_STATE_IN_RECOVERY &&
2586                     old_stop_stage != STOP_CONN_RECOVER) {
2587                         ISCSI_DBG_SESSION(session, "blocking session\n");
2588                         iscsi_block_session(session->cls_session);
2589                 }
2590         }
2591
2592         /*
2593          * flush queues.
2594          */
2595         spin_lock_bh(&session->lock);
2596         if (flag == STOP_CONN_RECOVER)
2597                 fail_all_commands(conn, -1, DID_TRANSPORT_DISRUPTED);
2598         else
2599                 fail_all_commands(conn, -1, DID_ERROR);
2600         flush_control_queues(session, conn);
2601         spin_unlock_bh(&session->lock);
2602         mutex_unlock(&session->eh_mutex);
2603 }
2604
2605 void iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
2606 {
2607         struct iscsi_conn *conn = cls_conn->dd_data;
2608         struct iscsi_session *session = conn->session;
2609
2610         switch (flag) {
2611         case STOP_CONN_RECOVER:
2612         case STOP_CONN_TERM:
2613                 iscsi_start_session_recovery(session, conn, flag);
2614                 break;
2615         default:
2616                 iscsi_conn_printk(KERN_ERR, conn,
2617                                   "invalid stop flag %d\n", flag);
2618         }
2619 }
2620 EXPORT_SYMBOL_GPL(iscsi_conn_stop);
2621
2622 int iscsi_conn_bind(struct iscsi_cls_session *cls_session,
2623                     struct iscsi_cls_conn *cls_conn, int is_leading)
2624 {
2625         struct iscsi_session *session = cls_session->dd_data;
2626         struct iscsi_conn *conn = cls_conn->dd_data;
2627
2628         spin_lock_bh(&session->lock);
2629         if (is_leading)
2630                 session->leadconn = conn;
2631         spin_unlock_bh(&session->lock);
2632
2633         /*
2634          * Unblock xmitworker(), Login Phase will pass through.
2635          */
2636         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
2637         clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
2638         return 0;
2639 }
2640 EXPORT_SYMBOL_GPL(iscsi_conn_bind);
2641
2642
2643 int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
2644                     enum iscsi_param param, char *buf, int buflen)
2645 {
2646         struct iscsi_conn *conn = cls_conn->dd_data;
2647         struct iscsi_session *session = conn->session;
2648         uint32_t value;
2649
2650         switch(param) {
2651         case ISCSI_PARAM_FAST_ABORT:
2652                 sscanf(buf, "%d", &session->fast_abort);
2653                 break;
2654         case ISCSI_PARAM_ABORT_TMO:
2655                 sscanf(buf, "%d", &session->abort_timeout);
2656                 break;
2657         case ISCSI_PARAM_LU_RESET_TMO:
2658                 sscanf(buf, "%d", &session->lu_reset_timeout);
2659                 break;
2660         case ISCSI_PARAM_PING_TMO:
2661                 sscanf(buf, "%d", &conn->ping_timeout);
2662                 break;
2663         case ISCSI_PARAM_RECV_TMO:
2664                 sscanf(buf, "%d", &conn->recv_timeout);
2665                 break;
2666         case ISCSI_PARAM_MAX_RECV_DLENGTH:
2667                 sscanf(buf, "%d", &conn->max_recv_dlength);
2668                 break;
2669         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
2670                 sscanf(buf, "%d", &conn->max_xmit_dlength);
2671                 break;
2672         case ISCSI_PARAM_HDRDGST_EN:
2673                 sscanf(buf, "%d", &conn->hdrdgst_en);
2674                 break;
2675         case ISCSI_PARAM_DATADGST_EN:
2676                 sscanf(buf, "%d", &conn->datadgst_en);
2677                 break;
2678         case ISCSI_PARAM_INITIAL_R2T_EN:
2679                 sscanf(buf, "%d", &session->initial_r2t_en);
2680                 break;
2681         case ISCSI_PARAM_MAX_R2T:
2682                 sscanf(buf, "%d", &session->max_r2t);
2683                 break;
2684         case ISCSI_PARAM_IMM_DATA_EN:
2685                 sscanf(buf, "%d", &session->imm_data_en);
2686                 break;
2687         case ISCSI_PARAM_FIRST_BURST:
2688                 sscanf(buf, "%d", &session->first_burst);
2689                 break;
2690         case ISCSI_PARAM_MAX_BURST:
2691                 sscanf(buf, "%d", &session->max_burst);
2692                 break;
2693         case ISCSI_PARAM_PDU_INORDER_EN:
2694                 sscanf(buf, "%d", &session->pdu_inorder_en);
2695                 break;
2696         case ISCSI_PARAM_DATASEQ_INORDER_EN:
2697                 sscanf(buf, "%d", &session->dataseq_inorder_en);
2698                 break;
2699         case ISCSI_PARAM_ERL:
2700                 sscanf(buf, "%d", &session->erl);
2701                 break;
2702         case ISCSI_PARAM_IFMARKER_EN:
2703                 sscanf(buf, "%d", &value);
2704                 BUG_ON(value);
2705                 break;
2706         case ISCSI_PARAM_OFMARKER_EN:
2707                 sscanf(buf, "%d", &value);
2708                 BUG_ON(value);
2709                 break;
2710         case ISCSI_PARAM_EXP_STATSN:
2711                 sscanf(buf, "%u", &conn->exp_statsn);
2712                 break;
2713         case ISCSI_PARAM_USERNAME:
2714                 kfree(session->username);
2715                 session->username = kstrdup(buf, GFP_KERNEL);
2716                 if (!session->username)
2717                         return -ENOMEM;
2718                 break;
2719         case ISCSI_PARAM_USERNAME_IN:
2720                 kfree(session->username_in);
2721                 session->username_in = kstrdup(buf, GFP_KERNEL);
2722                 if (!session->username_in)
2723                         return -ENOMEM;
2724                 break;
2725         case ISCSI_PARAM_PASSWORD:
2726                 kfree(session->password);
2727                 session->password = kstrdup(buf, GFP_KERNEL);
2728                 if (!session->password)
2729                         return -ENOMEM;
2730                 break;
2731         case ISCSI_PARAM_PASSWORD_IN:
2732                 kfree(session->password_in);
2733                 session->password_in = kstrdup(buf, GFP_KERNEL);
2734                 if (!session->password_in)
2735                         return -ENOMEM;
2736                 break;
2737         case ISCSI_PARAM_TARGET_NAME:
2738                 /* this should not change between logins */
2739                 if (session->targetname)
2740                         break;
2741
2742                 session->targetname = kstrdup(buf, GFP_KERNEL);
2743                 if (!session->targetname)
2744                         return -ENOMEM;
2745                 break;
2746         case ISCSI_PARAM_TPGT:
2747                 sscanf(buf, "%d", &session->tpgt);
2748                 break;
2749         case ISCSI_PARAM_PERSISTENT_PORT:
2750                 sscanf(buf, "%d", &conn->persistent_port);
2751                 break;
2752         case ISCSI_PARAM_PERSISTENT_ADDRESS:
2753                 /*
2754                  * this is the address returned in discovery so it should
2755                  * not change between logins.
2756                  */
2757                 if (conn->persistent_address)
2758                         break;
2759
2760                 conn->persistent_address = kstrdup(buf, GFP_KERNEL);
2761                 if (!conn->persistent_address)
2762                         return -ENOMEM;
2763                 break;
2764         case ISCSI_PARAM_IFACE_NAME:
2765                 if (!session->ifacename)
2766                         session->ifacename = kstrdup(buf, GFP_KERNEL);
2767                 break;
2768         case ISCSI_PARAM_INITIATOR_NAME:
2769                 if (!session->initiatorname)
2770                         session->initiatorname = kstrdup(buf, GFP_KERNEL);
2771                 break;
2772         default:
2773                 return -ENOSYS;
2774         }
2775
2776         return 0;
2777 }
2778 EXPORT_SYMBOL_GPL(iscsi_set_param);
2779
2780 int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
2781                             enum iscsi_param param, char *buf)
2782 {
2783         struct iscsi_session *session = cls_session->dd_data;
2784         int len;
2785
2786         switch(param) {
2787         case ISCSI_PARAM_FAST_ABORT:
2788                 len = sprintf(buf, "%d\n", session->fast_abort);
2789                 break;
2790         case ISCSI_PARAM_ABORT_TMO:
2791                 len = sprintf(buf, "%d\n", session->abort_timeout);
2792                 break;
2793         case ISCSI_PARAM_LU_RESET_TMO:
2794                 len = sprintf(buf, "%d\n", session->lu_reset_timeout);
2795                 break;
2796         case ISCSI_PARAM_INITIAL_R2T_EN:
2797                 len = sprintf(buf, "%d\n", session->initial_r2t_en);
2798                 break;
2799         case ISCSI_PARAM_MAX_R2T:
2800                 len = sprintf(buf, "%hu\n", session->max_r2t);
2801                 break;
2802         case ISCSI_PARAM_IMM_DATA_EN:
2803                 len = sprintf(buf, "%d\n", session->imm_data_en);
2804                 break;
2805         case ISCSI_PARAM_FIRST_BURST:
2806                 len = sprintf(buf, "%u\n", session->first_burst);
2807                 break;
2808         case ISCSI_PARAM_MAX_BURST:
2809                 len = sprintf(buf, "%u\n", session->max_burst);
2810                 break;
2811         case ISCSI_PARAM_PDU_INORDER_EN:
2812                 len = sprintf(buf, "%d\n", session->pdu_inorder_en);
2813                 break;
2814         case ISCSI_PARAM_DATASEQ_INORDER_EN:
2815                 len = sprintf(buf, "%d\n", session->dataseq_inorder_en);
2816                 break;
2817         case ISCSI_PARAM_ERL:
2818                 len = sprintf(buf, "%d\n", session->erl);
2819                 break;
2820         case ISCSI_PARAM_TARGET_NAME:
2821                 len = sprintf(buf, "%s\n", session->targetname);
2822                 break;
2823         case ISCSI_PARAM_TPGT:
2824                 len = sprintf(buf, "%d\n", session->tpgt);
2825                 break;
2826         case ISCSI_PARAM_USERNAME:
2827                 len = sprintf(buf, "%s\n", session->username);
2828                 break;
2829         case ISCSI_PARAM_USERNAME_IN:
2830                 len = sprintf(buf, "%s\n", session->username_in);
2831                 break;
2832         case ISCSI_PARAM_PASSWORD:
2833                 len = sprintf(buf, "%s\n", session->password);
2834                 break;
2835         case ISCSI_PARAM_PASSWORD_IN:
2836                 len = sprintf(buf, "%s\n", session->password_in);
2837                 break;
2838         case ISCSI_PARAM_IFACE_NAME:
2839                 len = sprintf(buf, "%s\n", session->ifacename);
2840                 break;
2841         case ISCSI_PARAM_INITIATOR_NAME:
2842                 if (!session->initiatorname)
2843                         len = sprintf(buf, "%s\n", "unknown");
2844                 else
2845                         len = sprintf(buf, "%s\n", session->initiatorname);
2846                 break;
2847         default:
2848                 return -ENOSYS;
2849         }
2850
2851         return len;
2852 }
2853 EXPORT_SYMBOL_GPL(iscsi_session_get_param);
2854
2855 int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
2856                          enum iscsi_param param, char *buf)
2857 {
2858         struct iscsi_conn *conn = cls_conn->dd_data;
2859         int len;
2860
2861         switch(param) {
2862         case ISCSI_PARAM_PING_TMO:
2863                 len = sprintf(buf, "%u\n", conn->ping_timeout);
2864                 break;
2865         case ISCSI_PARAM_RECV_TMO:
2866                 len = sprintf(buf, "%u\n", conn->recv_timeout);
2867                 break;
2868         case ISCSI_PARAM_MAX_RECV_DLENGTH:
2869                 len = sprintf(buf, "%u\n", conn->max_recv_dlength);
2870                 break;
2871         case ISCSI_PARAM_MAX_XMIT_DLENGTH:
2872                 len = sprintf(buf, "%u\n", conn->max_xmit_dlength);
2873                 break;
2874         case ISCSI_PARAM_HDRDGST_EN:
2875                 len = sprintf(buf, "%d\n", conn->hdrdgst_en);
2876                 break;
2877         case ISCSI_PARAM_DATADGST_EN:
2878                 len = sprintf(buf, "%d\n", conn->datadgst_en);
2879                 break;
2880         case ISCSI_PARAM_IFMARKER_EN:
2881                 len = sprintf(buf, "%d\n", conn->ifmarker_en);
2882                 break;
2883         case ISCSI_PARAM_OFMARKER_EN:
2884                 len = sprintf(buf, "%d\n", conn->ofmarker_en);
2885                 break;
2886         case ISCSI_PARAM_EXP_STATSN:
2887                 len = sprintf(buf, "%u\n", conn->exp_statsn);
2888                 break;
2889         case ISCSI_PARAM_PERSISTENT_PORT:
2890                 len = sprintf(buf, "%d\n", conn->persistent_port);
2891                 break;
2892         case ISCSI_PARAM_PERSISTENT_ADDRESS:
2893                 len = sprintf(buf, "%s\n", conn->persistent_address);
2894                 break;
2895         default:
2896                 return -ENOSYS;
2897         }
2898
2899         return len;
2900 }
2901 EXPORT_SYMBOL_GPL(iscsi_conn_get_param);
2902
2903 int iscsi_host_get_param(struct Scsi_Host *shost, enum iscsi_host_param param,
2904                          char *buf)
2905 {
2906         struct iscsi_host *ihost = shost_priv(shost);
2907         int len;
2908
2909         switch (param) {
2910         case ISCSI_HOST_PARAM_NETDEV_NAME:
2911                 if (!ihost->netdev)
2912                         len = sprintf(buf, "%s\n", "default");
2913                 else
2914                         len = sprintf(buf, "%s\n", ihost->netdev);
2915                 break;
2916         case ISCSI_HOST_PARAM_HWADDRESS:
2917                 if (!ihost->hwaddress)
2918                         len = sprintf(buf, "%s\n", "default");
2919                 else
2920                         len = sprintf(buf, "%s\n", ihost->hwaddress);
2921                 break;
2922         case ISCSI_HOST_PARAM_INITIATOR_NAME:
2923                 if (!ihost->initiatorname)
2924                         len = sprintf(buf, "%s\n", "unknown");
2925                 else
2926                         len = sprintf(buf, "%s\n", ihost->initiatorname);
2927                 break;
2928         case ISCSI_HOST_PARAM_IPADDRESS:
2929                 if (!strlen(ihost->local_address))
2930                         len = sprintf(buf, "%s\n", "unknown");
2931                 else
2932                         len = sprintf(buf, "%s\n",
2933                                       ihost->local_address);
2934                 break;
2935         default:
2936                 return -ENOSYS;
2937         }
2938
2939         return len;
2940 }
2941 EXPORT_SYMBOL_GPL(iscsi_host_get_param);
2942
2943 int iscsi_host_set_param(struct Scsi_Host *shost, enum iscsi_host_param param,
2944                          char *buf, int buflen)
2945 {
2946         struct iscsi_host *ihost = shost_priv(shost);
2947
2948         switch (param) {
2949         case ISCSI_HOST_PARAM_NETDEV_NAME:
2950                 if (!ihost->netdev)
2951                         ihost->netdev = kstrdup(buf, GFP_KERNEL);
2952                 break;
2953         case ISCSI_HOST_PARAM_HWADDRESS:
2954                 if (!ihost->hwaddress)
2955                         ihost->hwaddress = kstrdup(buf, GFP_KERNEL);
2956                 break;
2957         case ISCSI_HOST_PARAM_INITIATOR_NAME:
2958                 if (!ihost->initiatorname)
2959                         ihost->initiatorname = kstrdup(buf, GFP_KERNEL);
2960                 break;
2961         default:
2962                 return -ENOSYS;
2963         }
2964
2965         return 0;
2966 }
2967 EXPORT_SYMBOL_GPL(iscsi_host_set_param);
2968
2969 MODULE_AUTHOR("Mike Christie");
2970 MODULE_DESCRIPTION("iSCSI library functions");
2971 MODULE_LICENSE("GPL");